Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

219 files changed, 49459 insertions, 0 deletions

diff --git a/src/basic/MurmurHash2.c b/src/basic/MurmurHash2.c
new file mode 100644
index 0000000..5859af0
--- /dev/null
+++ b/src/basic/MurmurHash2.c
@@ -0,0 +1,90 @@
+//-----------------------------------------------------------------------------
+// MurmurHash2 was written by Austin Appleby, and is placed in the public
+// domain. The author hereby disclaims copyright to this source code.
+
+// Note - This code makes a few assumptions about how your machine behaves -
+
+// 1. We can read a 4-byte value from any address without crashing
+// 2. sizeof(int) == 4
+
+// And it has a few limitations -
+
+// 1. It will not work incrementally.
+// 2. It will not produce the same results on little-endian and big-endian
+//    machines.
+
+#include "MurmurHash2.h"
+
+#if __GNUC__ >= 7
+_Pragma("GCC diagnostic ignored \"-Wimplicit-fallthrough\"")
+#endif
+
+//-----------------------------------------------------------------------------
+// Platform-specific functions and macros
+
+// Microsoft Visual Studio
+
+#if defined(_MSC_VER)
+
+#define BIG_CONSTANT(x) (x)
+
+// Other compilers
+
+#else        // defined(_MSC_VER)
+
+#define BIG_CONSTANT(x) (x##LLU)
+
+#endif // !defined(_MSC_VER)
+
+//-----------------------------------------------------------------------------
+
+uint32_t MurmurHash2 ( const void * key, int len, uint32_t seed )
+{
+  // 'm' and 'r' are mixing constants generated offline.
+  // They're not really 'magic', they just happen to work well.
+
+  const uint32_t m = 0x5bd1e995;
+  const int r = 24;
+
+  // Initialize the hash to a 'random' value
+
+  uint32_t h = seed ^ len;
+
+  // Mix 4 bytes at a time into the hash
+
+  const unsigned char * data = (const unsigned char *)key;
+
+  while (len >= 4)
+  {
+    uint32_t k = *(uint32_t*)data;
+
+    k *= m;
+    k ^= k >> r;
+    k *= m;
+
+    h *= m;
+    h ^= k;
+
+    data += 4;
+    len -= 4;
+  }
+
+  // Handle the last few bytes of the input array
+
+  switch(len)
+  {
+  case 3: h ^= data[2] << 16; /* fall through */
+  case 2: h ^= data[1] << 8;  /* fall through */
+  case 1: h ^= data[0];       /* fall through */
+      h *= m;
+  };
+
+  // Do a few final mixes of the hash to ensure the last few
+  // bytes are well-incorporated.
+
+  h ^= h >> 13;
+  h *= m;
+  h ^= h >> 15;
+
+  return h;
+}
diff --git a/src/basic/MurmurHash2.h b/src/basic/MurmurHash2.h
new file mode 100644
index 0000000..1aef3af
--- /dev/null
+++ b/src/basic/MurmurHash2.h
@@ -0,0 +1,30 @@
+//-----------------------------------------------------------------------------
+// MurmurHash2 was written by Austin Appleby, and is placed in the public
+// domain. The author hereby disclaims copyright to this source code.
+
+#pragma once
+
+//-----------------------------------------------------------------------------
+// Platform-specific functions and macros
+
+// Microsoft Visual Studio
+
+#if defined(_MSC_VER)
+
+typedef unsigned char uint8_t;
+typedef unsigned long uint32_t;
+typedef unsigned __int64 uint64_t;
+
+// Other compilers
+
+#else        // defined(_MSC_VER)
+
+#include <stdint.h>
+
+#endif // !defined(_MSC_VER)
+
+//-----------------------------------------------------------------------------
+
+uint32_t MurmurHash2        ( const void * key, int len, uint32_t seed );
+
+//-----------------------------------------------------------------------------
diff --git a/src/basic/af-list.c b/src/basic/af-list.c
new file mode 100644
index 0000000..abad221
--- /dev/null
+++ b/src/basic/af-list.c
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <string.h>
+#include <sys/socket.h>
+
+#include "af-list.h"
+#include "macro.h"
+
+static const struct af_name* lookup_af(register const char *str, register GPERF_LEN_TYPE len);
+
+#include "af-from-name.h"
+#include "af-to-name.h"
+
+const char *af_to_name(int id) {
+
+        if (id <= 0)
+                return NULL;
+
+        if ((size_t) id >= ELEMENTSOF(af_names))
+                return NULL;
+
+        return af_names[id];
+}
+
+int af_from_name(const char *name) {
+        const struct af_name *sc;
+
+        assert(name);
+
+        sc = lookup_af(name, strlen(name));
+        if (!sc)
+                return -EINVAL;
+
+        return sc->id;
+}
+
+int af_max(void) {
+        return ELEMENTSOF(af_names);
+}
diff --git a/src/basic/af-list.h b/src/basic/af-list.h
new file mode 100644
index 0000000..8342323
--- /dev/null
+++ b/src/basic/af-list.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/socket.h>
+
+#include "string-util.h"
+
+const char *af_to_name(int id);
+int af_from_name(const char *name);
+
+static inline const char* af_to_name_short(int id) {
+        const char *f;
+
+        if (id == AF_UNSPEC)
+                return "*";
+
+        f = af_to_name(id);
+        if (!f)
+                return "unknown";
+
+        assert(startswith(f, "AF_"));
+        return f + 3;
+}
+
+int af_max(void);
diff --git a/src/basic/af-to-name.awk b/src/basic/af-to-name.awk
new file mode 100644
index 0000000..18d0a89
--- /dev/null
+++ b/src/basic/af-to-name.awk
@@ -0,0 +1,9 @@
+BEGIN{
+        print "static const char* const af_names[] = { "
+}
+!/AF_FILE/ && !/AF_ROUTE/ && !/AF_LOCAL/ {
+        printf "        [%s] = \"%s\",\n", $1, $1
+}
+END{
+        print "};"
+}
diff --git a/src/basic/alloc-util.c b/src/basic/alloc-util.c
new file mode 100644
index 0000000..ab7a42c
--- /dev/null
+++ b/src/basic/alloc-util.c
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "macro.h"
+#include "util.h"
+
+void* memdup(const void *p, size_t l) {
+        void *ret;
+
+        assert(l == 0 || p);
+
+        ret = malloc(l ?: 1);
+        if (!ret)
+                return NULL;
+
+        memcpy(ret, p, l);
+        return ret;
+}
+
+void* memdup_suffix0(const void *p, size_t l) {
+        void *ret;
+
+        assert(l == 0 || p);
+
+        /* The same as memdup() but place a safety NUL byte after the allocated memory */
+
+        ret = malloc(l + 1);
+        if (!ret)
+                return NULL;
+
+        *((uint8_t*) mempcpy(ret, p, l)) = 0;
+        return ret;
+}
+
+void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size) {
+        size_t a, newalloc;
+        void *q;
+
+        assert(p);
+        assert(allocated);
+
+        if (*allocated >= need)
+                return *p;
+
+        newalloc = MAX(need * 2, 64u / size);
+        a = newalloc * size;
+
+        /* check for overflows */
+        if (a < size * need)
+                return NULL;
+
+        q = realloc(*p, a);
+        if (!q)
+                return NULL;
+
+        *p = q;
+        *allocated = newalloc;
+        return q;
+}
+
+void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size) {
+        size_t prev;
+        uint8_t *q;
+
+        assert(p);
+        assert(allocated);
+
+        prev = *allocated;
+
+        q = greedy_realloc(p, allocated, need, size);
+        if (!q)
+                return NULL;
+
+        if (*allocated > prev)
+                memzero(q + prev * size, (*allocated - prev) * size);
+
+        return q;
+}
diff --git a/src/basic/alloc-util.h b/src/basic/alloc-util.h
new file mode 100644
index 0000000..893a123
--- /dev/null
+++ b/src/basic/alloc-util.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <alloca.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "macro.h"
+
+typedef void (*free_func_t)(void *p);
+
+/* If for some reason more than 4M are allocated on the stack, let's abort immediately. It's better than
+ * proceeding and smashing the stack limits. Note that by default RLIMIT_STACK is 8M on Linux. */
+#define ALLOCA_MAX (4U*1024U*1024U)
+
+#define new(t, n) ((t*) malloc_multiply(sizeof(t), (n)))
+
+#define new0(t, n) ((t*) calloc((n) ?: 1, sizeof(t)))
+
+#define newa(t, n)                                                      \
+        ({                                                              \
+                size_t _n_ = n;                                         \
+                assert(!size_multiply_overflow(sizeof(t), _n_));        \
+                assert(sizeof(t)*_n_ <= ALLOCA_MAX);                    \
+                (t*) alloca(sizeof(t)*_n_);                             \
+        })
+
+#define newa0(t, n)                                                     \
+        ({                                                              \
+                size_t _n_ = n;                                         \
+                assert(!size_multiply_overflow(sizeof(t), _n_));        \
+                assert(sizeof(t)*_n_ <= ALLOCA_MAX);                    \
+                (t*) alloca0(sizeof(t)*_n_);                            \
+        })
+
+#define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n)))
+
+#define newdup_suffix0(t, p, n) ((t*) memdup_suffix0_multiply(p, sizeof(t), (n)))
+
+#define malloc0(n) (calloc(1, (n)))
+
+static inline void *mfree(void *memory) {
+        free(memory);
+        return NULL;
+}
+
+#define free_and_replace(a, b)                  \
+        ({                                      \
+                free(a);                        \
+                (a) = (b);                      \
+                (b) = NULL;                     \
+                0;                              \
+        })
+
+void* memdup(const void *p, size_t l) _alloc_(2);
+void* memdup_suffix0(const void *p, size_t l) _alloc_(2);
+
+#define memdupa(p, l)                           \
+        ({                                      \
+                void *_q_;                      \
+                size_t _l_ = l;                 \
+                assert(_l_ <= ALLOCA_MAX);      \
+                _q_ = alloca(_l_);              \
+                memcpy(_q_, p, _l_);            \
+        })
+
+#define memdupa_suffix0(p, l)                   \
+        ({                                      \
+                void *_q_;                      \
+                size_t _l_ = l;                 \
+                assert(_l_ <= ALLOCA_MAX);      \
+                _q_ = alloca(_l_ + 1);          \
+                ((uint8_t*) _q_)[_l_] = 0;      \
+                memcpy(_q_, p, _l_);            \
+        })
+
+static inline void freep(void *p) {
+        free(*(void**) p);
+}
+
+#define _cleanup_free_ _cleanup_(freep)
+
+static inline bool size_multiply_overflow(size_t size, size_t need) {
+        return _unlikely_(need != 0 && size > (SIZE_MAX / need));
+}
+
+_malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t size, size_t need) {
+        if (size_multiply_overflow(size, need))
+                return NULL;
+
+        return malloc(size * need ?: 1);
+}
+
+#if !HAVE_REALLOCARRAY
+_alloc_(2, 3) static inline void *reallocarray(void *p, size_t need, size_t size) {
+        if (size_multiply_overflow(size, need))
+                return NULL;
+
+        return realloc(p, size * need ?: 1);
+}
+#endif
+
+_alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t size, size_t need) {
+        if (size_multiply_overflow(size, need))
+                return NULL;
+
+        return memdup(p, size * need);
+}
+
+_alloc_(2, 3) static inline void *memdup_suffix0_multiply(const void *p, size_t size, size_t need) {
+        if (size_multiply_overflow(size, need))
+                return NULL;
+
+        return memdup_suffix0(p, size * need);
+}
+
+void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
+void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
+
+#define GREEDY_REALLOC(array, allocated, need)                          \
+        greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
+
+#define GREEDY_REALLOC0(array, allocated, need)                         \
+        greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
+
+#define alloca0(n)                                      \
+        ({                                              \
+                char *_new_;                            \
+                size_t _len_ = n;                       \
+                assert(_len_ <= ALLOCA_MAX);            \
+                _new_ = alloca(_len_);                  \
+                (void *) memset(_new_, 0, _len_);       \
+        })
+
+/* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
+#define alloca_align(size, align)                                       \
+        ({                                                              \
+                void *_ptr_;                                            \
+                size_t _mask_ = (align) - 1;                            \
+                size_t _size_ = size;                                   \
+                assert(_size_ <= ALLOCA_MAX);                           \
+                _ptr_ = alloca(_size_ + _mask_);                        \
+                (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_);         \
+        })
+
+#define alloca0_align(size, align)                                      \
+        ({                                                              \
+                void *_new_;                                            \
+                size_t _xsize_ = (size);                                \
+                _new_ = alloca_align(_xsize_, (align));                 \
+                (void*)memset(_new_, 0, _xsize_);                       \
+        })
+
+/* Takes inspiration from Rusts's Option::take() method: reads and returns a pointer, but at the same time resets it to
+ * NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
+#define TAKE_PTR(ptr)                           \
+        ({                                      \
+                typeof(ptr) _ptr_ = (ptr);      \
+                (ptr) = NULL;                   \
+                _ptr_;                          \
+        })
diff --git a/src/basic/architecture.c b/src/basic/architecture.c
new file mode 100644
index 0000000..85837b5
--- /dev/null
+++ b/src/basic/architecture.c
@@ -0,0 +1,178 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <sys/utsname.h>
+
+#include "architecture.h"
+#include "macro.h"
+#include "string-table.h"
+#include "string-util.h"
+
+int uname_architecture(void) {
+
+        /* Return a sanitized enum identifying the architecture we are
+         * running on. This is based on uname(), and the user may
+         * hence control what this returns by using
+         * personality(). This puts the user in control on systems
+         * that can run binaries of multiple architectures.
+         *
+         * We do not translate the string returned by uname()
+         * 1:1. Instead we try to clean it up and break down the
+         * confusion on x86 and arm in particular.
+         *
+         * We do not try to distinguish CPUs not CPU features, but
+         * actual architectures, i.e. that have genuinely different
+         * code. */
+
+        static const struct {
+                const char *machine;
+                int arch;
+        } arch_map[] = {
+#if defined(__x86_64__) || defined(__i386__)
+                { "x86_64",     ARCHITECTURE_X86_64   },
+                { "i686",       ARCHITECTURE_X86      },
+                { "i586",       ARCHITECTURE_X86      },
+                { "i486",       ARCHITECTURE_X86      },
+                { "i386",       ARCHITECTURE_X86      },
+#elif defined(__powerpc__) || defined(__powerpc64__)
+                { "ppc64",      ARCHITECTURE_PPC64    },
+                { "ppc64le",    ARCHITECTURE_PPC64_LE },
+                { "ppc",        ARCHITECTURE_PPC      },
+                { "ppcle",      ARCHITECTURE_PPC_LE   },
+#elif defined(__ia64__)
+                { "ia64",       ARCHITECTURE_IA64     },
+#elif defined(__hppa__) || defined(__hppa64__)
+                { "parisc64",   ARCHITECTURE_PARISC64 },
+                { "parisc",     ARCHITECTURE_PARISC   },
+#elif defined(__s390__) || defined(__s390x__)
+                { "s390x",      ARCHITECTURE_S390X    },
+                { "s390",       ARCHITECTURE_S390     },
+#elif defined(__sparc__)
+                { "sparc64",    ARCHITECTURE_SPARC64  },
+                { "sparc",      ARCHITECTURE_SPARC    },
+#elif defined(__mips__) || defined(__mips64__)
+                { "mips64",     ARCHITECTURE_MIPS64   },
+                { "mips",       ARCHITECTURE_MIPS     },
+#elif defined(__alpha__)
+                { "alpha" ,     ARCHITECTURE_ALPHA    },
+#elif defined(__arm__) || defined(__aarch64__)
+                { "aarch64",    ARCHITECTURE_ARM64    },
+                { "aarch64_be", ARCHITECTURE_ARM64_BE },
+                { "armv4l",     ARCHITECTURE_ARM      },
+                { "armv4b",     ARCHITECTURE_ARM_BE   },
+                { "armv4tl",    ARCHITECTURE_ARM      },
+                { "armv4tb",    ARCHITECTURE_ARM_BE   },
+                { "armv5tl",    ARCHITECTURE_ARM      },
+                { "armv5tb",    ARCHITECTURE_ARM_BE   },
+                { "armv5tel",   ARCHITECTURE_ARM      },
+                { "armv5teb" ,  ARCHITECTURE_ARM_BE   },
+                { "armv5tejl",  ARCHITECTURE_ARM      },
+                { "armv5tejb",  ARCHITECTURE_ARM_BE   },
+                { "armv6l",     ARCHITECTURE_ARM      },
+                { "armv6b",     ARCHITECTURE_ARM_BE   },
+                { "armv7l",     ARCHITECTURE_ARM      },
+                { "armv7b",     ARCHITECTURE_ARM_BE   },
+                { "armv7ml",    ARCHITECTURE_ARM      },
+                { "armv7mb",    ARCHITECTURE_ARM_BE   },
+                { "armv4l",     ARCHITECTURE_ARM      },
+                { "armv4b",     ARCHITECTURE_ARM_BE   },
+                { "armv4tl",    ARCHITECTURE_ARM      },
+                { "armv4tb",    ARCHITECTURE_ARM_BE   },
+                { "armv5tl",    ARCHITECTURE_ARM      },
+                { "armv5tb",    ARCHITECTURE_ARM_BE   },
+                { "armv5tel",   ARCHITECTURE_ARM      },
+                { "armv5teb",   ARCHITECTURE_ARM_BE   },
+                { "armv5tejl",  ARCHITECTURE_ARM      },
+                { "armv5tejb",  ARCHITECTURE_ARM_BE   },
+                { "armv6l",     ARCHITECTURE_ARM      },
+                { "armv6b",     ARCHITECTURE_ARM_BE   },
+                { "armv7l",     ARCHITECTURE_ARM      },
+                { "armv7b",     ARCHITECTURE_ARM_BE   },
+                { "armv7ml",    ARCHITECTURE_ARM      },
+                { "armv7mb",    ARCHITECTURE_ARM_BE   },
+                { "armv8l",     ARCHITECTURE_ARM      },
+                { "armv8b",     ARCHITECTURE_ARM_BE   },
+#elif defined(__sh__) || defined(__sh64__)
+                { "sh5",        ARCHITECTURE_SH64     },
+                { "sh2",        ARCHITECTURE_SH       },
+                { "sh2a",       ARCHITECTURE_SH       },
+                { "sh3",        ARCHITECTURE_SH       },
+                { "sh4",        ARCHITECTURE_SH       },
+                { "sh4a",       ARCHITECTURE_SH       },
+#elif defined(__m68k__)
+                { "m68k",       ARCHITECTURE_M68K     },
+#elif defined(__tilegx__)
+                { "tilegx",     ARCHITECTURE_TILEGX   },
+#elif defined(__cris__)
+                { "crisv32",    ARCHITECTURE_CRIS     },
+#elif defined(__nios2__)
+                { "nios2",      ARCHITECTURE_NIOS2    },
+#elif defined(__riscv__) || defined(__riscv)
+        /* __riscv__ is obsolete, remove in 2018 */
+                { "riscv32",    ARCHITECTURE_RISCV32  },
+                { "riscv64",    ARCHITECTURE_RISCV64  },
+#  if __SIZEOF_POINTER__ == 4
+                { "riscv",      ARCHITECTURE_RISCV32  },
+#  elif __SIZEOF_POINTER__ == 8
+                { "riscv",      ARCHITECTURE_RISCV64  },
+#  endif
+#elif defined(__arc__)
+                { "arc",        ARCHITECTURE_ARC      },
+                { "arceb",      ARCHITECTURE_ARC_BE   },
+#else
+#error "Please register your architecture here!"
+#endif
+        };
+
+        static int cached = _ARCHITECTURE_INVALID;
+        struct utsname u;
+        unsigned i;
+
+        if (cached != _ARCHITECTURE_INVALID)
+                return cached;
+
+        assert_se(uname(&u) >= 0);
+
+        for (i = 0; i < ELEMENTSOF(arch_map); i++)
+                if (streq(arch_map[i].machine, u.machine))
+                        return cached = arch_map[i].arch;
+
+        assert_not_reached("Couldn't identify architecture. You need to patch systemd.");
+        return _ARCHITECTURE_INVALID;
+}
+
+static const char *const architecture_table[_ARCHITECTURE_MAX] = {
+        [ARCHITECTURE_X86] = "x86",
+        [ARCHITECTURE_X86_64] = "x86-64",
+        [ARCHITECTURE_PPC] = "ppc",
+        [ARCHITECTURE_PPC_LE] = "ppc-le",
+        [ARCHITECTURE_PPC64] = "ppc64",
+        [ARCHITECTURE_PPC64_LE] = "ppc64-le",
+        [ARCHITECTURE_IA64] = "ia64",
+        [ARCHITECTURE_PARISC] = "parisc",
+        [ARCHITECTURE_PARISC64] = "parisc64",
+        [ARCHITECTURE_S390] = "s390",
+        [ARCHITECTURE_S390X] = "s390x",
+        [ARCHITECTURE_SPARC] = "sparc",
+        [ARCHITECTURE_SPARC64] = "sparc64",
+        [ARCHITECTURE_MIPS] = "mips",
+        [ARCHITECTURE_MIPS_LE] = "mips-le",
+        [ARCHITECTURE_MIPS64] = "mips64",
+        [ARCHITECTURE_MIPS64_LE] = "mips64-le",
+        [ARCHITECTURE_ALPHA] = "alpha",
+        [ARCHITECTURE_ARM] = "arm",
+        [ARCHITECTURE_ARM_BE] = "arm-be",
+        [ARCHITECTURE_ARM64] = "arm64",
+        [ARCHITECTURE_ARM64_BE] = "arm64-be",
+        [ARCHITECTURE_SH] = "sh",
+        [ARCHITECTURE_SH64] = "sh64",
+        [ARCHITECTURE_M68K] = "m68k",
+        [ARCHITECTURE_TILEGX] = "tilegx",
+        [ARCHITECTURE_CRIS] = "cris",
+        [ARCHITECTURE_NIOS2] = "nios2",
+        [ARCHITECTURE_RISCV32] = "riscv32",
+        [ARCHITECTURE_RISCV64] = "riscv64",
+        [ARCHITECTURE_ARC] = "arc",
+        [ARCHITECTURE_ARC_BE] = "arc-be",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(architecture, int);
diff --git a/src/basic/architecture.h b/src/basic/architecture.h
new file mode 100644
index 0000000..443e890
--- /dev/null
+++ b/src/basic/architecture.h
@@ -0,0 +1,237 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <endian.h>
+
+#include "macro.h"
+#include "util.h"
+
+/* A cleaned up architecture definition. We don't want to get lost in
+ * processor features, models, generations or even ABIs. Hence we
+ * focus on general family, and distinguish word width and
+ * endianness. */
+
+enum {
+        ARCHITECTURE_X86 = 0,
+        ARCHITECTURE_X86_64,
+        ARCHITECTURE_PPC,
+        ARCHITECTURE_PPC_LE,
+        ARCHITECTURE_PPC64,
+        ARCHITECTURE_PPC64_LE,
+        ARCHITECTURE_IA64,
+        ARCHITECTURE_PARISC,
+        ARCHITECTURE_PARISC64,
+        ARCHITECTURE_S390,
+        ARCHITECTURE_S390X,
+        ARCHITECTURE_SPARC,
+        ARCHITECTURE_SPARC64,
+        ARCHITECTURE_MIPS,
+        ARCHITECTURE_MIPS_LE,
+        ARCHITECTURE_MIPS64,
+        ARCHITECTURE_MIPS64_LE,
+        ARCHITECTURE_ALPHA,
+        ARCHITECTURE_ARM,
+        ARCHITECTURE_ARM_BE,
+        ARCHITECTURE_ARM64,
+        ARCHITECTURE_ARM64_BE,
+        ARCHITECTURE_SH,
+        ARCHITECTURE_SH64,
+        ARCHITECTURE_M68K,
+        ARCHITECTURE_TILEGX,
+        ARCHITECTURE_CRIS,
+        ARCHITECTURE_NIOS2,
+        ARCHITECTURE_RISCV32,
+        ARCHITECTURE_RISCV64,
+        ARCHITECTURE_ARC,
+        ARCHITECTURE_ARC_BE,
+        _ARCHITECTURE_MAX,
+        _ARCHITECTURE_INVALID = -1
+};
+
+int uname_architecture(void);
+
+/*
+ * LIB_ARCH_TUPLE should resolve to the local library path
+ * architecture tuple systemd is built for, according to the Debian
+ * tuple list:
+ *
+ * https://wiki.debian.org/Multiarch/Tuples
+ *
+ * This is used in library search paths that should understand
+ * Debian's paths on all distributions.
+ */
+
+#if defined(__x86_64__)
+#  define native_architecture() ARCHITECTURE_X86_64
+#  if defined(__ILP32__)
+#    define LIB_ARCH_TUPLE "x86_64-linux-gnux32"
+#  else
+#    define LIB_ARCH_TUPLE "x86_64-linux-gnu"
+#  endif
+#  define SECONDARY_ARCHITECTURE ARCHITECTURE_X86
+#elif defined(__i386__)
+#  define native_architecture() ARCHITECTURE_X86
+#  define LIB_ARCH_TUPLE "i386-linux-gnu"
+#elif defined(__powerpc64__)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_PPC64
+#    define LIB_ARCH_TUPLE "ppc64-linux-gnu"
+#    define SECONDARY_ARCHITECTURE ARCHITECTURE_PPC
+#  else
+#    define native_architecture() ARCHITECTURE_PPC64_LE
+#    define LIB_ARCH_TUPLE  "powerpc64le-linux-gnu"
+#    define SECONDARY_ARCHITECTURE ARCHITECTURE_PPC_LE
+#  endif
+#elif defined(__powerpc__)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_PPC
+#    if defined(__NO_FPRS__)
+#      define LIB_ARCH_TUPLE "powerpc-linux-gnuspe"
+#    else
+#      define LIB_ARCH_TUPLE "powerpc-linux-gnu"
+#    endif
+#  else
+#    define native_architecture() ARCHITECTURE_PPC_LE
+#    error "Missing LIB_ARCH_TUPLE for PPCLE"
+#  endif
+#elif defined(__ia64__)
+#  define native_architecture() ARCHITECTURE_IA64
+#  define LIB_ARCH_TUPLE "ia64-linux-gnu"
+#elif defined(__hppa64__)
+#  define native_architecture() ARCHITECTURE_PARISC64
+#  error "Missing LIB_ARCH_TUPLE for HPPA64"
+#elif defined(__hppa__)
+#  define native_architecture() ARCHITECTURE_PARISC
+#  define LIB_ARCH_TUPLE "hppa‑linux‑gnu"
+#elif defined(__s390x__)
+#  define native_architecture() ARCHITECTURE_S390X
+#  define LIB_ARCH_TUPLE "s390x-linux-gnu"
+#  define SECONDARY_ARCHITECTURE ARCHITECTURE_S390
+#elif defined(__s390__)
+#  define native_architecture() ARCHITECTURE_S390
+#  define LIB_ARCH_TUPLE "s390-linux-gnu"
+#elif defined(__sparc__) && defined (__arch64__)
+#  define native_architecture() ARCHITECTURE_SPARC64
+#  define LIB_ARCH_TUPLE "sparc64-linux-gnu"
+#elif defined(__sparc__)
+#  define native_architecture() ARCHITECTURE_SPARC
+#  define LIB_ARCH_TUPLE "sparc-linux-gnu"
+#elif defined(__mips64) && defined(__LP64__)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_MIPS64
+#    define LIB_ARCH_TUPLE "mips64-linux-gnuabi64"
+#  else
+#    define native_architecture() ARCHITECTURE_MIPS64_LE
+#    define LIB_ARCH_TUPLE "mips64el-linux-gnuabi64"
+#  endif
+#elif defined(__mips64)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_MIPS64
+#    define LIB_ARCH_TUPLE "mips64-linux-gnuabin32"
+#  else
+#    define native_architecture() ARCHITECTURE_MIPS64_LE
+#    define LIB_ARCH_TUPLE "mips64el-linux-gnuabin32"
+#  endif
+#elif defined(__mips__)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_MIPS
+#    define LIB_ARCH_TUPLE "mips-linux-gnu"
+#  else
+#    define native_architecture() ARCHITECTURE_MIPS_LE
+#    define LIB_ARCH_TUPLE "mipsel-linux-gnu"
+#  endif
+#elif defined(__alpha__)
+#  define native_architecture() ARCHITECTURE_ALPHA
+#  define LIB_ARCH_TUPLE "alpha-linux-gnu"
+#elif defined(__aarch64__)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_ARM64_BE
+#    define LIB_ARCH_TUPLE "aarch64_be-linux-gnu"
+#  else
+#    define native_architecture() ARCHITECTURE_ARM64
+#    define LIB_ARCH_TUPLE "aarch64-linux-gnu"
+#    define SECONDARY_ARCHITECTURE ARCHITECTURE_ARM
+#  endif
+#elif defined(__arm__)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_ARM_BE
+#    if defined(__ARM_EABI__)
+#      if defined(__ARM_PCS_VFP)
+#        define LIB_ARCH_TUPLE "armeb-linux-gnueabihf"
+#      else
+#        define LIB_ARCH_TUPLE "armeb-linux-gnueabi"
+#      endif
+#    else
+#      define LIB_ARCH_TUPLE "armeb-linux-gnu"
+#    endif
+#  else
+#    define native_architecture() ARCHITECTURE_ARM
+#    if defined(__ARM_EABI__)
+#      if defined(__ARM_PCS_VFP)
+#        define LIB_ARCH_TUPLE "arm-linux-gnueabihf"
+#      else
+#        define LIB_ARCH_TUPLE "arm-linux-gnueabi"
+#      endif
+#    else
+#      define LIB_ARCH_TUPLE "arm-linux-gnu"
+#    endif
+#  endif
+#elif defined(__sh64__)
+#  define native_architecture() ARCHITECTURE_SH64
+#  error "Missing LIB_ARCH_TUPLE for SH64"
+#elif defined(__sh__)
+#  define native_architecture() ARCHITECTURE_SH
+#  if defined(__SH1__)
+#    define LIB_ARCH_TUPLE "sh1-linux-gnu"
+#  elif defined(__SH2__)
+#    define LIB_ARCH_TUPLE "sh2-linux-gnu"
+#  elif defined(__SH2A__)
+#    define LIB_ARCH_TUPLE "sh2a-linux-gnu"
+#  elif defined(__SH2E__)
+#    define LIB_ARCH_TUPLE "sh2e-linux-gnu"
+#  elif defined(__SH3__)
+#    define LIB_ARCH_TUPLE "sh3-linux-gnu"
+#  elif defined(__SH3E__)
+#    define LIB_ARCH_TUPLE "sh3e-linux-gnu"
+#  elif defined(__SH4__) && !defined(__SH4A__)
+#    define LIB_ARCH_TUPLE "sh4-linux-gnu"
+#  elif defined(__SH4A__)
+#    define LIB_ARCH_TUPLE "sh4a-linux-gnu"
+#  endif
+#elif defined(__m68k__)
+#  define native_architecture() ARCHITECTURE_M68K
+#  define LIB_ARCH_TUPLE "m68k-linux-gnu"
+#elif defined(__tilegx__)
+#  define native_architecture() ARCHITECTURE_TILEGX
+#  define LIB_ARCH_TUPLE "tilegx-linux-gnu"
+#elif defined(__cris__)
+#  define native_architecture() ARCHITECTURE_CRIS
+#  error "Missing LIB_ARCH_TUPLE for CRIS"
+#elif defined(__nios2__)
+#  define native_architecture() ARCHITECTURE_NIOS2
+#  define LIB_ARCH_TUPLE "nios2-linux-gnu"
+#elif defined(__riscv__) || defined(__riscv)
+        /* __riscv__ is obsolete, remove in 2018 */
+#  if __SIZEOF_POINTER__ == 4
+#    define native_architecture() ARCHITECTURE_RISCV32
+#    define LIB_ARCH_TUPLE "riscv32-linux-gnu"
+#  elif __SIZEOF_POINTER__ == 8
+#    define native_architecture() ARCHITECTURE_RISCV64
+#    define LIB_ARCH_TUPLE "riscv64-linux-gnu"
+#  else
+#    error "Unrecognized riscv architecture variant"
+#  endif
+#elif defined(__arc__)
+#  if __BYTE_ORDER == __BIG_ENDIAN
+#    define native_architecture() ARCHITECTURE_ARC_BE
+#    define LIB_ARCH_TUPLE "arceb-linux"
+#  else
+#    define native_architecture() ARCHITECTURE_ARC
+#    define LIB_ARCH_TUPLE "arc-linux"
+#  endif
+#else
+#  error "Please register your architecture here!"
+#endif
+
+const char *architecture_to_string(int a) _const_;
+int architecture_from_string(const char *s) _pure_;
diff --git a/src/basic/arphrd-list.c b/src/basic/arphrd-list.c
new file mode 100644
index 0000000..b6e2486
--- /dev/null
+++ b/src/basic/arphrd-list.c
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <net/if_arp.h>
+#include <string.h>
+
+#include "arphrd-list.h"
+#include "macro.h"
+#include "missing_network.h"
+
+static const struct arphrd_name* lookup_arphrd(register const char *str, register GPERF_LEN_TYPE len);
+
+#include "arphrd-from-name.h"
+#include "arphrd-to-name.h"
+
+const char *arphrd_to_name(int id) {
+
+        if (id <= 0)
+                return NULL;
+
+        if ((size_t) id >= ELEMENTSOF(arphrd_names))
+                return NULL;
+
+        return arphrd_names[id];
+}
+
+int arphrd_from_name(const char *name) {
+        const struct arphrd_name *sc;
+
+        assert(name);
+
+        sc = lookup_arphrd(name, strlen(name));
+        if (!sc)
+                return -EINVAL;
+
+        return sc->id;
+}
+
+int arphrd_max(void) {
+        return ELEMENTSOF(arphrd_names);
+}
diff --git a/src/basic/arphrd-list.h b/src/basic/arphrd-list.h
new file mode 100644
index 0000000..5dcfe5e
--- /dev/null
+++ b/src/basic/arphrd-list.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+const char *arphrd_to_name(int id);
+int arphrd_from_name(const char *name);
+
+int arphrd_max(void);
diff --git a/src/basic/arphrd-to-name.awk b/src/basic/arphrd-to-name.awk
new file mode 100644
index 0000000..5a35673
--- /dev/null
+++ b/src/basic/arphrd-to-name.awk
@@ -0,0 +1,9 @@
+BEGIN{
+        print "static const char* const arphrd_names[] = { "
+}
+!/CISCO/ {
+        printf "        [ARPHRD_%s] = \"%s\",\n", $1, $1
+}
+END{
+        print "};"
+}
diff --git a/src/basic/async.c b/src/basic/async.c
new file mode 100644
index 0000000..c45ca01
--- /dev/null
+++ b/src/basic/async.c
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <pthread.h>
+#include <stddef.h>
+#include <unistd.h>
+
+#include "async.h"
+#include "fd-util.h"
+#include "log.h"
+#include "macro.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "util.h"
+
+int asynchronous_job(void* (*func)(void *p), void *arg) {
+        sigset_t ss, saved_ss;
+        pthread_attr_t a;
+        pthread_t t;
+        int r, k;
+
+        /* It kinda sucks that we have to resort to threads to implement an asynchronous close(), but well, such is
+         * life. */
+
+        r = pthread_attr_init(&a);
+        if (r > 0)
+                return -r;
+
+        r = pthread_attr_setdetachstate(&a, PTHREAD_CREATE_DETACHED);
+        if (r > 0) {
+                r = -r;
+                goto finish;
+        }
+
+        assert_se(sigfillset(&ss) >= 0);
+
+        /* Block all signals before forking off the thread, so that the new thread is started with all signals
+         * blocked. This way the existence of the new thread won't affect signal handling in other threads. */
+
+        r = pthread_sigmask(SIG_BLOCK, &ss, &saved_ss);
+        if (r > 0) {
+                r = -r;
+                goto finish;
+        }
+
+        r = pthread_create(&t, &a, func, arg);
+
+        k = pthread_sigmask(SIG_SETMASK, &saved_ss, NULL);
+
+        if (r > 0)
+                r = -r;
+        else if (k > 0)
+                r = -k;
+        else
+                r = 0;
+
+finish:
+        pthread_attr_destroy(&a);
+        return r;
+}
+
+int asynchronous_sync(pid_t *ret_pid) {
+        int r;
+
+        /* This forks off an invocation of fork() as a child process, in order to initiate synchronization to
+         * disk. Note that we implement this as helper process rather than thread as we don't want the sync() to hang our
+         * original process ever, and a thread would do that as the process can't exit with threads hanging in blocking
+         * syscalls. */
+
+        r = safe_fork("(sd-sync)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS, ret_pid);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                /* Child process */
+                (void) sync();
+                _exit(EXIT_SUCCESS);
+        }
+
+        return 0;
+}
+
+static void *close_thread(void *p) {
+        (void) pthread_setname_np(pthread_self(), "close");
+
+        assert_se(close_nointr(PTR_TO_FD(p)) != -EBADF);
+        return NULL;
+}
+
+int asynchronous_close(int fd) {
+        int r;
+
+        /* This is supposed to behave similar to safe_close(), but
+         * actually invoke close() asynchronously, so that it will
+         * never block. Ideally the kernel would have an API for this,
+         * but it doesn't, so we work around it, and hide this as a
+         * far away as we can. */
+
+        if (fd >= 0) {
+                PROTECT_ERRNO;
+
+                r = asynchronous_job(close_thread, FD_TO_PTR(fd));
+                if (r < 0)
+                         assert_se(close_nointr(fd) != -EBADF);
+        }
+
+        return -1;
+}
diff --git a/src/basic/async.h b/src/basic/async.h
new file mode 100644
index 0000000..3160613
--- /dev/null
+++ b/src/basic/async.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+int asynchronous_job(void* (*func)(void *p), void *arg);
+
+int asynchronous_sync(pid_t *ret_pid);
+int asynchronous_close(int fd);
diff --git a/src/basic/audit-util.c b/src/basic/audit-util.c
new file mode 100644
index 0000000..5cbaef3
--- /dev/null
+++ b/src/basic/audit-util.c
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <linux/netlink.h>
+#include <stdio.h>
+#include <sys/socket.h>
+
+#include "alloc-util.h"
+#include "audit-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "process-util.h"
+#include "user-util.h"
+
+int audit_session_from_pid(pid_t pid, uint32_t *id) {
+        _cleanup_free_ char *s = NULL;
+        const char *p;
+        uint32_t u;
+        int r;
+
+        assert(id);
+
+        /* We don't convert ENOENT to ESRCH here, since we can't
+         * really distuingish between "audit is not available in the
+         * kernel" and "the process does not exist", both which will
+         * result in ENOENT. */
+
+        p = procfs_file_alloca(pid, "sessionid");
+
+        r = read_one_line_file(p, &s);
+        if (r < 0)
+                return r;
+
+        r = safe_atou32(s, &u);
+        if (r < 0)
+                return r;
+
+        if (!audit_session_is_valid(u))
+                return -ENODATA;
+
+        *id = u;
+        return 0;
+}
+
+int audit_loginuid_from_pid(pid_t pid, uid_t *uid) {
+        _cleanup_free_ char *s = NULL;
+        const char *p;
+        uid_t u;
+        int r;
+
+        assert(uid);
+
+        p = procfs_file_alloca(pid, "loginuid");
+
+        r = read_one_line_file(p, &s);
+        if (r < 0)
+                return r;
+
+        r = parse_uid(s, &u);
+        if (r == -ENXIO) /* the UID was -1 */
+                return -ENODATA;
+        if (r < 0)
+                return r;
+
+        *uid = u;
+        return 0;
+}
+
+bool use_audit(void) {
+        static int cached_use = -1;
+
+        if (cached_use < 0) {
+                int fd;
+
+                fd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_AUDIT);
+                if (fd < 0) {
+                        cached_use = !IN_SET(errno, EAFNOSUPPORT, EPROTONOSUPPORT, EPERM);
+                        if (!cached_use)
+                                log_debug_errno(errno, "Won't talk to audit: %m");
+                } else {
+                        cached_use = true;
+                        safe_close(fd);
+                }
+        }
+
+        return cached_use;
+}
diff --git a/src/basic/audit-util.h b/src/basic/audit-util.h
new file mode 100644
index 0000000..c9fc498
--- /dev/null
+++ b/src/basic/audit-util.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#define AUDIT_SESSION_INVALID ((uint32_t) -1)
+
+int audit_session_from_pid(pid_t pid, uint32_t *id);
+int audit_loginuid_from_pid(pid_t pid, uid_t *uid);
+
+bool use_audit(void);
+
+static inline bool audit_session_is_valid(uint32_t id) {
+        return id > 0 && id != AUDIT_SESSION_INVALID;
+}
diff --git a/src/basic/blockdev-util.c b/src/basic/blockdev-util.c
new file mode 100644
index 0000000..3017ecd
--- /dev/null
+++ b/src/basic/blockdev-util.c
@@ -0,0 +1,181 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <sys/stat.h>
+#include <sys/statfs.h>
+
+#include "alloc-util.h"
+#include "blockdev-util.h"
+#include "btrfs-util.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "stat-util.h"
+
+int block_get_whole_disk(dev_t d, dev_t *ret) {
+        char p[SYS_BLOCK_PATH_MAX("/partition")];
+        _cleanup_free_ char *s = NULL;
+        dev_t devt;
+        int r;
+
+        assert(ret);
+
+        /* If it has a queue this is good enough for us */
+        xsprintf_sys_block_path(p, "/queue", d);
+        if (access(p, F_OK) >= 0) {
+                *ret = d;
+                return 0;
+        }
+
+        /* If it is a partition find the originating device */
+        xsprintf_sys_block_path(p, "/partition", d);
+        if (access(p, F_OK) < 0)
+                return -ENOENT;
+
+        /* Get parent dev_t */
+        xsprintf_sys_block_path(p, "/../dev", d);
+        r = read_one_line_file(p, &s);
+        if (r < 0)
+                return r;
+
+        r = parse_dev(s, &devt);
+        if (r < 0)
+                return r;
+
+        /* Only return this if it is really good enough for us. */
+        xsprintf_sys_block_path(p, "/queue", devt);
+        if (access(p, F_OK) < 0)
+                return -ENOENT;
+
+        *ret = devt;
+        return 0;
+}
+
+int get_block_device(const char *path, dev_t *dev) {
+        struct stat st;
+        struct statfs sfs;
+
+        assert(path);
+        assert(dev);
+
+        /* Get's the block device directly backing a file system. If
+         * the block device is encrypted, returns the device mapper
+         * block device. */
+
+        if (lstat(path, &st))
+                return -errno;
+
+        if (major(st.st_dev) != 0) {
+                *dev = st.st_dev;
+                return 1;
+        }
+
+        if (statfs(path, &sfs) < 0)
+                return -errno;
+
+        if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC))
+                return btrfs_get_block_device(path, dev);
+
+        *dev = 0;
+        return 0;
+}
+
+int block_get_originating(dev_t dt, dev_t *ret) {
+        _cleanup_closedir_ DIR *d = NULL;
+        _cleanup_free_ char *t = NULL;
+        char p[SYS_BLOCK_PATH_MAX("/slaves")];
+        struct dirent *de, *found = NULL;
+        const char *q;
+        dev_t devt;
+        int r;
+
+        /* For the specified block device tries to chase it through the layers, in case LUKS-style DM stacking is used,
+         * trying to find the next underlying layer.  */
+
+        xsprintf_sys_block_path(p, "/slaves", dt);
+        d = opendir(p);
+        if (!d)
+                return -errno;
+
+        FOREACH_DIRENT_ALL(de, d, return -errno) {
+
+                if (dot_or_dot_dot(de->d_name))
+                        continue;
+
+                if (!IN_SET(de->d_type, DT_LNK, DT_UNKNOWN))
+                        continue;
+
+                if (found) {
+                        _cleanup_free_ char *u = NULL, *v = NULL, *a = NULL, *b = NULL;
+
+                        /* We found a device backed by multiple other devices. We don't really support automatic
+                         * discovery on such setups, with the exception of dm-verity partitions. In this case there are
+                         * two backing devices: the data partition and the hash partition. We are fine with such
+                         * setups, however, only if both partitions are on the same physical device. Hence, let's
+                         * verify this. */
+
+                        u = strjoin(p, "/", de->d_name, "/../dev");
+                        if (!u)
+                                return -ENOMEM;
+
+                        v = strjoin(p, "/", found->d_name, "/../dev");
+                        if (!v)
+                                return -ENOMEM;
+
+                        r = read_one_line_file(u, &a);
+                        if (r < 0)
+                                return log_debug_errno(r, "Failed to read %s: %m", u);
+
+                        r = read_one_line_file(v, &b);
+                        if (r < 0)
+                                return log_debug_errno(r, "Failed to read %s: %m", v);
+
+                        /* Check if the parent device is the same. If not, then the two backing devices are on
+                         * different physical devices, and we don't support that. */
+                        if (!streq(a, b))
+                                return -ENOTUNIQ;
+                }
+
+                found = de;
+        }
+
+        if (!found)
+                return -ENOENT;
+
+        q = strjoina(p, "/", found->d_name, "/dev");
+
+        r = read_one_line_file(q, &t);
+        if (r < 0)
+                return r;
+
+        r = parse_dev(t, &devt);
+        if (r < 0)
+                return -EINVAL;
+
+        if (major(devt) == 0)
+                return -ENOENT;
+
+        *ret = devt;
+        return 1;
+}
+
+int get_block_device_harder(const char *path, dev_t *ret) {
+        int r;
+
+        assert(path);
+        assert(ret);
+
+        /* Gets the backing block device for a file system, and handles LUKS encrypted file systems, looking for its
+         * immediate parent, if there is one. */
+
+        r = get_block_device(path, ret);
+        if (r <= 0)
+                return r;
+
+        r = block_get_originating(*ret, ret);
+        if (r < 0)
+                log_debug_errno(r, "Failed to chase block device '%s', ignoring: %m", path);
+
+        return 1;
+}
diff --git a/src/basic/blockdev-util.h b/src/basic/blockdev-util.h
new file mode 100644
index 0000000..6d8a796
--- /dev/null
+++ b/src/basic/blockdev-util.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/types.h>
+
+#include "macro.h"
+#include "stdio-util.h"
+#include "string-util.h"
+
+#define SYS_BLOCK_PATH_MAX(suffix)                                      \
+        (STRLEN("/sys/dev/block/") + DECIMAL_STR_MAX(dev_t) + 1 + DECIMAL_STR_MAX(dev_t) + strlen_ptr(suffix))
+#define xsprintf_sys_block_path(buf, suffix, devno)                     \
+        xsprintf(buf, "/sys/dev/block/%u:%u%s", major(devno), minor(devno), strempty(suffix))
+
+int block_get_whole_disk(dev_t d, dev_t *ret);
+int block_get_originating(dev_t d, dev_t *ret);
+
+int get_block_device(const char *path, dev_t *dev);
+
+int get_block_device_harder(const char *path, dev_t *dev);
diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c
new file mode 100644
index 0000000..da4dd2a
--- /dev/null
+++ b/src/basic/btrfs-util.c
@@ -0,0 +1,1993 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/fs.h>
+#include <linux/loop.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/sysmacros.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "blockdev-util.h"
+#include "btrfs-util.h"
+#include "chattr-util.h"
+#include "copy.h"
+#include "device-nodes.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "path-util.h"
+#include "rm-rf.h"
+#include "smack-util.h"
+#include "sparse-endian.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "time-util.h"
+#include "util.h"
+
+/* WARNING: Be careful with file system ioctls! When we get an fd, we
+ * need to make sure it either refers to only a regular file or
+ * directory, or that it is located on btrfs, before invoking any
+ * btrfs ioctls. The ioctl numbers are reused by some device drivers
+ * (such as DRM), and hence might have bad effects when invoked on
+ * device nodes (that reference drivers) rather than fds to normal
+ * files or directories. */
+
+static int validate_subvolume_name(const char *name) {
+
+        if (!filename_is_valid(name))
+                return -EINVAL;
+
+        if (strlen(name) > BTRFS_SUBVOL_NAME_MAX)
+                return -E2BIG;
+
+        return 0;
+}
+
+static int extract_subvolume_name(const char *path, const char **subvolume) {
+        const char *fn;
+        int r;
+
+        assert(path);
+        assert(subvolume);
+
+        fn = basename(path);
+
+        r = validate_subvolume_name(fn);
+        if (r < 0)
+                return r;
+
+        *subvolume = fn;
+        return 0;
+}
+
+int btrfs_is_filesystem(int fd) {
+        struct statfs sfs;
+
+        assert(fd >= 0);
+
+        if (fstatfs(fd, &sfs) < 0)
+                return -errno;
+
+        return F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC);
+}
+
+int btrfs_is_subvol_fd(int fd) {
+        struct stat st;
+
+        assert(fd >= 0);
+
+        /* On btrfs subvolumes always have the inode 256 */
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (!S_ISDIR(st.st_mode) || st.st_ino != 256)
+                return 0;
+
+        return btrfs_is_filesystem(fd);
+}
+
+int btrfs_is_subvol(const char *path) {
+        _cleanup_close_ int fd = -1;
+
+        assert(path);
+
+        fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_is_subvol_fd(fd);
+}
+
+int btrfs_subvol_make_fd(int fd, const char *subvolume) {
+        struct btrfs_ioctl_vol_args args = {};
+        _cleanup_close_ int real_fd = -1;
+        int r;
+
+        assert(subvolume);
+
+        r = validate_subvolume_name(subvolume);
+        if (r < 0)
+                return r;
+
+        r = fcntl(fd, F_GETFL);
+        if (r < 0)
+                return -errno;
+        if (FLAGS_SET(r, O_PATH)) {
+                /* An O_PATH fd was specified, let's convert here to a proper one, as btrfs ioctl's can't deal with
+                 * O_PATH. */
+
+                real_fd = fd_reopen(fd, O_RDONLY|O_CLOEXEC|O_DIRECTORY);
+                if (real_fd < 0)
+                        return real_fd;
+
+                fd = real_fd;
+        }
+
+        strncpy(args.name, subvolume, sizeof(args.name)-1);
+
+        if (ioctl(fd, BTRFS_IOC_SUBVOL_CREATE, &args) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_subvol_make(const char *path) {
+        _cleanup_close_ int fd = -1;
+        const char *subvolume;
+        int r;
+
+        assert(path);
+
+        r = extract_subvolume_name(path, &subvolume);
+        if (r < 0)
+                return r;
+
+        fd = open_parent(path, O_CLOEXEC, 0);
+        if (fd < 0)
+                return fd;
+
+        return btrfs_subvol_make_fd(fd, subvolume);
+}
+
+int btrfs_subvol_set_read_only_fd(int fd, bool b) {
+        uint64_t flags, nflags;
+        struct stat st;
+
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (!S_ISDIR(st.st_mode) || st.st_ino != 256)
+                return -EINVAL;
+
+        if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0)
+                return -errno;
+
+        if (b)
+                nflags = flags | BTRFS_SUBVOL_RDONLY;
+        else
+                nflags = flags & ~BTRFS_SUBVOL_RDONLY;
+
+        if (flags == nflags)
+                return 0;
+
+        if (ioctl(fd, BTRFS_IOC_SUBVOL_SETFLAGS, &nflags) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_subvol_set_read_only(const char *path, bool b) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_subvol_set_read_only_fd(fd, b);
+}
+
+int btrfs_subvol_get_read_only_fd(int fd) {
+        uint64_t flags;
+        struct stat st;
+
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (!S_ISDIR(st.st_mode) || st.st_ino != 256)
+                return -EINVAL;
+
+        if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0)
+                return -errno;
+
+        return !!(flags & BTRFS_SUBVOL_RDONLY);
+}
+
+int btrfs_reflink(int infd, int outfd) {
+        int r;
+
+        assert(infd >= 0);
+        assert(outfd >= 0);
+
+        /* Make sure we invoke the ioctl on a regular file, so that no device driver accidentally gets it. */
+
+        r = fd_verify_regular(outfd);
+        if (r < 0)
+                return r;
+
+        if (ioctl(outfd, BTRFS_IOC_CLONE, infd) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_clone_range(int infd, uint64_t in_offset, int outfd, uint64_t out_offset, uint64_t sz) {
+        struct btrfs_ioctl_clone_range_args args = {
+                .src_fd = infd,
+                .src_offset = in_offset,
+                .src_length = sz,
+                .dest_offset = out_offset,
+        };
+        int r;
+
+        assert(infd >= 0);
+        assert(outfd >= 0);
+        assert(sz > 0);
+
+        r = fd_verify_regular(outfd);
+        if (r < 0)
+                return r;
+
+        if (ioctl(outfd, BTRFS_IOC_CLONE_RANGE, &args) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_get_block_device_fd(int fd, dev_t *dev) {
+        struct btrfs_ioctl_fs_info_args fsi = {};
+        uint64_t id;
+        int r;
+
+        assert(fd >= 0);
+        assert(dev);
+
+        r = btrfs_is_filesystem(fd);
+        if (r < 0)
+                return r;
+        if (!r)
+                return -ENOTTY;
+
+        if (ioctl(fd, BTRFS_IOC_FS_INFO, &fsi) < 0)
+                return -errno;
+
+        /* We won't do this for btrfs RAID */
+        if (fsi.num_devices != 1) {
+                *dev = 0;
+                return 0;
+        }
+
+        for (id = 1; id <= fsi.max_id; id++) {
+                struct btrfs_ioctl_dev_info_args di = {
+                        .devid = id,
+                };
+                struct stat st;
+
+                if (ioctl(fd, BTRFS_IOC_DEV_INFO, &di) < 0) {
+                        if (errno == ENODEV)
+                                continue;
+
+                        return -errno;
+                }
+
+                if (stat((char*) di.path, &st) < 0)
+                        return -errno;
+
+                if (!S_ISBLK(st.st_mode))
+                        return -ENODEV;
+
+                if (major(st.st_rdev) == 0)
+                        return -ENODEV;
+
+                *dev = st.st_rdev;
+                return 1;
+        }
+
+        return -ENODEV;
+}
+
+int btrfs_get_block_device(const char *path, dev_t *dev) {
+        _cleanup_close_ int fd = -1;
+
+        assert(path);
+        assert(dev);
+
+        fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_get_block_device_fd(fd, dev);
+}
+
+int btrfs_subvol_get_id_fd(int fd, uint64_t *ret) {
+        struct btrfs_ioctl_ino_lookup_args args = {
+                .objectid = BTRFS_FIRST_FREE_OBJECTID
+        };
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        r = btrfs_is_filesystem(fd);
+        if (r < 0)
+                return r;
+        if (!r)
+                return -ENOTTY;
+
+        if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args) < 0)
+                return -errno;
+
+        *ret = args.treeid;
+        return 0;
+}
+
+int btrfs_subvol_get_id(int fd, const char *subvol, uint64_t *ret) {
+        _cleanup_close_ int subvol_fd = -1;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        subvol_fd = openat(fd, subvol, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (subvol_fd < 0)
+                return -errno;
+
+        return btrfs_subvol_get_id_fd(subvol_fd, ret);
+}
+
+static bool btrfs_ioctl_search_args_inc(struct btrfs_ioctl_search_args *args) {
+        assert(args);
+
+        /* the objectid, type, offset together make up the btrfs key,
+         * which is considered a single 136byte integer when
+         * comparing. This call increases the counter by one, dealing
+         * with the overflow between the overflows */
+
+        if (args->key.min_offset < (uint64_t) -1) {
+                args->key.min_offset++;
+                return true;
+        }
+
+        if (args->key.min_type < (uint8_t) -1) {
+                args->key.min_type++;
+                args->key.min_offset = 0;
+                return true;
+        }
+
+        if (args->key.min_objectid < (uint64_t) -1) {
+                args->key.min_objectid++;
+                args->key.min_offset = 0;
+                args->key.min_type = 0;
+                return true;
+        }
+
+        return 0;
+}
+
+static void btrfs_ioctl_search_args_set(struct btrfs_ioctl_search_args *args, const struct btrfs_ioctl_search_header *h) {
+        assert(args);
+        assert(h);
+
+        args->key.min_objectid = h->objectid;
+        args->key.min_type = h->type;
+        args->key.min_offset = h->offset;
+}
+
+static int btrfs_ioctl_search_args_compare(const struct btrfs_ioctl_search_args *args) {
+        int r;
+
+        assert(args);
+
+        /* Compare min and max */
+
+        r = CMP(args->key.min_objectid, args->key.max_objectid);
+        if (r != 0)
+                return r;
+
+        r = CMP(args->key.min_type, args->key.max_type);
+        if (r != 0)
+                return r;
+
+        return CMP(args->key.min_offset, args->key.max_offset);
+}
+
+#define FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args)                  \
+        for ((i) = 0,                                                   \
+             (sh) = (const struct btrfs_ioctl_search_header*) (args).buf; \
+             (i) < (args).key.nr_items;                                 \
+             (i)++,                                                     \
+             (sh) = (const struct btrfs_ioctl_search_header*) ((uint8_t*) (sh) + sizeof(struct btrfs_ioctl_search_header) + (sh)->len))
+
+#define BTRFS_IOCTL_SEARCH_HEADER_BODY(sh)                              \
+        ((void*) ((uint8_t*) sh + sizeof(struct btrfs_ioctl_search_header)))
+
+int btrfs_subvol_get_info_fd(int fd, uint64_t subvol_id, BtrfsSubvolInfo *ret) {
+        struct btrfs_ioctl_search_args args = {
+                /* Tree of tree roots */
+                .key.tree_id = BTRFS_ROOT_TREE_OBJECTID,
+
+                /* Look precisely for the subvolume items */
+                .key.min_type = BTRFS_ROOT_ITEM_KEY,
+                .key.max_type = BTRFS_ROOT_ITEM_KEY,
+
+                .key.min_offset = 0,
+                .key.max_offset = (uint64_t) -1,
+
+                /* No restrictions on the other components */
+                .key.min_transid = 0,
+                .key.max_transid = (uint64_t) -1,
+        };
+
+        bool found = false;
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        if (subvol_id == 0) {
+                r = btrfs_subvol_get_id_fd(fd, &subvol_id);
+                if (r < 0)
+                        return r;
+        } else {
+                r = btrfs_is_filesystem(fd);
+                if (r < 0)
+                        return r;
+                if (!r)
+                        return -ENOTTY;
+        }
+
+        args.key.min_objectid = args.key.max_objectid = subvol_id;
+
+        while (btrfs_ioctl_search_args_compare(&args) <= 0) {
+                const struct btrfs_ioctl_search_header *sh;
+                unsigned i;
+
+                args.key.nr_items = 256;
+                if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
+                        return -errno;
+
+                if (args.key.nr_items <= 0)
+                        break;
+
+                FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
+
+                        const struct btrfs_root_item *ri;
+
+                        /* Make sure we start the next search at least from this entry */
+                        btrfs_ioctl_search_args_set(&args, sh);
+
+                        if (sh->objectid != subvol_id)
+                                continue;
+                        if (sh->type != BTRFS_ROOT_ITEM_KEY)
+                                continue;
+
+                        /* Older versions of the struct lacked the otime setting */
+                        if (sh->len < offsetof(struct btrfs_root_item, otime) + sizeof(struct btrfs_timespec))
+                                continue;
+
+                        ri = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh);
+
+                        ret->otime = (usec_t) le64toh(ri->otime.sec) * USEC_PER_SEC +
+                                (usec_t) le32toh(ri->otime.nsec) / NSEC_PER_USEC;
+
+                        ret->subvol_id = subvol_id;
+                        ret->read_only = le64toh(ri->flags) & BTRFS_ROOT_SUBVOL_RDONLY;
+
+                        assert_cc(sizeof(ri->uuid) == sizeof(ret->uuid));
+                        memcpy(&ret->uuid, ri->uuid, sizeof(ret->uuid));
+                        memcpy(&ret->parent_uuid, ri->parent_uuid, sizeof(ret->parent_uuid));
+
+                        found = true;
+                        goto finish;
+                }
+
+                /* Increase search key by one, to read the next item, if we can. */
+                if (!btrfs_ioctl_search_args_inc(&args))
+                        break;
+        }
+
+finish:
+        if (!found)
+                return -ENODATA;
+
+        return 0;
+}
+
+int btrfs_qgroup_get_quota_fd(int fd, uint64_t qgroupid, BtrfsQuotaInfo *ret) {
+
+        struct btrfs_ioctl_search_args args = {
+                /* Tree of quota items */
+                .key.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+
+                /* The object ID is always 0 */
+                .key.min_objectid = 0,
+                .key.max_objectid = 0,
+
+                /* Look precisely for the quota items */
+                .key.min_type = BTRFS_QGROUP_STATUS_KEY,
+                .key.max_type = BTRFS_QGROUP_LIMIT_KEY,
+
+                /* No restrictions on the other components */
+                .key.min_transid = 0,
+                .key.max_transid = (uint64_t) -1,
+        };
+
+        bool found_info = false, found_limit = false;
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        if (qgroupid == 0) {
+                r = btrfs_subvol_get_id_fd(fd, &qgroupid);
+                if (r < 0)
+                        return r;
+        } else {
+                r = btrfs_is_filesystem(fd);
+                if (r < 0)
+                        return r;
+                if (!r)
+                        return -ENOTTY;
+        }
+
+        args.key.min_offset = args.key.max_offset = qgroupid;
+
+        while (btrfs_ioctl_search_args_compare(&args) <= 0) {
+                const struct btrfs_ioctl_search_header *sh;
+                unsigned i;
+
+                args.key.nr_items = 256;
+                if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) {
+                        if (errno == ENOENT) /* quota tree is missing: quota disabled */
+                                break;
+
+                        return -errno;
+                }
+
+                if (args.key.nr_items <= 0)
+                        break;
+
+                FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
+
+                        /* Make sure we start the next search at least from this entry */
+                        btrfs_ioctl_search_args_set(&args, sh);
+
+                        if (sh->objectid != 0)
+                                continue;
+                        if (sh->offset != qgroupid)
+                                continue;
+
+                        if (sh->type == BTRFS_QGROUP_INFO_KEY) {
+                                const struct btrfs_qgroup_info_item *qii = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh);
+
+                                ret->referenced = le64toh(qii->rfer);
+                                ret->exclusive = le64toh(qii->excl);
+
+                                found_info = true;
+
+                        } else if (sh->type == BTRFS_QGROUP_LIMIT_KEY) {
+                                const struct btrfs_qgroup_limit_item *qli = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh);
+
+                                if (le64toh(qli->flags) & BTRFS_QGROUP_LIMIT_MAX_RFER)
+                                        ret->referenced_max = le64toh(qli->max_rfer);
+                                else
+                                        ret->referenced_max = (uint64_t) -1;
+
+                                if (le64toh(qli->flags) & BTRFS_QGROUP_LIMIT_MAX_EXCL)
+                                        ret->exclusive_max = le64toh(qli->max_excl);
+                                else
+                                        ret->exclusive_max = (uint64_t) -1;
+
+                                found_limit = true;
+                        }
+
+                        if (found_info && found_limit)
+                                goto finish;
+                }
+
+                /* Increase search key by one, to read the next item, if we can. */
+                if (!btrfs_ioctl_search_args_inc(&args))
+                        break;
+        }
+
+finish:
+        if (!found_limit && !found_info)
+                return -ENODATA;
+
+        if (!found_info) {
+                ret->referenced = (uint64_t) -1;
+                ret->exclusive = (uint64_t) -1;
+        }
+
+        if (!found_limit) {
+                ret->referenced_max = (uint64_t) -1;
+                ret->exclusive_max = (uint64_t) -1;
+        }
+
+        return 0;
+}
+
+int btrfs_qgroup_get_quota(const char *path, uint64_t qgroupid, BtrfsQuotaInfo *ret) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_qgroup_get_quota_fd(fd, qgroupid, ret);
+}
+
+int btrfs_subvol_find_subtree_qgroup(int fd, uint64_t subvol_id, uint64_t *ret) {
+        uint64_t level, lowest = (uint64_t) -1, lowest_qgroupid = 0;
+        _cleanup_free_ uint64_t *qgroups = NULL;
+        int r, n, i;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        /* This finds the "subtree" qgroup for a specific
+         * subvolume. This only works for subvolumes that have been
+         * prepared with btrfs_subvol_auto_qgroup_fd() with
+         * insert_intermediary_qgroup=true (or equivalent). For others
+         * it will return the leaf qgroup instead. The two cases may
+         * be distuingished via the return value, which is 1 in case
+         * an appropriate "subtree" qgroup was found, and 0
+         * otherwise. */
+
+        if (subvol_id == 0) {
+                r = btrfs_subvol_get_id_fd(fd, &subvol_id);
+                if (r < 0)
+                        return r;
+        }
+
+        r = btrfs_qgroupid_split(subvol_id, &level, NULL);
+        if (r < 0)
+                return r;
+        if (level != 0) /* Input must be a leaf qgroup */
+                return -EINVAL;
+
+        n = btrfs_qgroup_find_parents(fd, subvol_id, &qgroups);
+        if (n < 0)
+                return n;
+
+        for (i = 0; i < n; i++) {
+                uint64_t id;
+
+                r = btrfs_qgroupid_split(qgroups[i], &level, &id);
+                if (r < 0)
+                        return r;
+
+                if (id != subvol_id)
+                        continue;
+
+                if (lowest == (uint64_t) -1 || level < lowest) {
+                        lowest_qgroupid = qgroups[i];
+                        lowest = level;
+                }
+        }
+
+        if (lowest == (uint64_t) -1) {
+                /* No suitable higher-level qgroup found, let's return
+                 * the leaf qgroup instead, and indicate that with the
+                 * return value. */
+
+                *ret = subvol_id;
+                return 0;
+        }
+
+        *ret = lowest_qgroupid;
+        return 1;
+}
+
+int btrfs_subvol_get_subtree_quota_fd(int fd, uint64_t subvol_id, BtrfsQuotaInfo *ret) {
+        uint64_t qgroupid;
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        /* This determines the quota data of the qgroup with the
+         * lowest level, that shares the id part with the specified
+         * subvolume. This is useful for determining the quota data
+         * for entire subvolume subtrees, as long as the subtrees have
+         * been set up with btrfs_qgroup_subvol_auto_fd() or in a
+         * compatible way */
+
+        r = btrfs_subvol_find_subtree_qgroup(fd, subvol_id, &qgroupid);
+        if (r < 0)
+                return r;
+
+        return btrfs_qgroup_get_quota_fd(fd, qgroupid, ret);
+}
+
+int btrfs_subvol_get_subtree_quota(const char *path, uint64_t subvol_id, BtrfsQuotaInfo *ret) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_subvol_get_subtree_quota_fd(fd, subvol_id, ret);
+}
+
+int btrfs_defrag_fd(int fd) {
+        int r;
+
+        assert(fd >= 0);
+
+        r = fd_verify_regular(fd);
+        if (r < 0)
+                return r;
+
+        if (ioctl(fd, BTRFS_IOC_DEFRAG, NULL) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_defrag(const char *p) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(p, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_defrag_fd(fd);
+}
+
+int btrfs_quota_enable_fd(int fd, bool b) {
+        struct btrfs_ioctl_quota_ctl_args args = {
+                .cmd = b ? BTRFS_QUOTA_CTL_ENABLE : BTRFS_QUOTA_CTL_DISABLE,
+        };
+        int r;
+
+        assert(fd >= 0);
+
+        r = btrfs_is_filesystem(fd);
+        if (r < 0)
+                return r;
+        if (!r)
+                return -ENOTTY;
+
+        if (ioctl(fd, BTRFS_IOC_QUOTA_CTL, &args) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_quota_enable(const char *path, bool b) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_quota_enable_fd(fd, b);
+}
+
+int btrfs_qgroup_set_limit_fd(int fd, uint64_t qgroupid, uint64_t referenced_max) {
+
+        struct btrfs_ioctl_qgroup_limit_args args = {
+                .lim.max_rfer = referenced_max,
+                .lim.flags = BTRFS_QGROUP_LIMIT_MAX_RFER,
+        };
+        unsigned c;
+        int r;
+
+        assert(fd >= 0);
+
+        if (qgroupid == 0) {
+                r = btrfs_subvol_get_id_fd(fd, &qgroupid);
+                if (r < 0)
+                        return r;
+        } else {
+                r = btrfs_is_filesystem(fd);
+                if (r < 0)
+                        return r;
+                if (!r)
+                        return -ENOTTY;
+        }
+
+        args.qgroupid = qgroupid;
+
+        for (c = 0;; c++) {
+                if (ioctl(fd, BTRFS_IOC_QGROUP_LIMIT, &args) < 0) {
+
+                        if (errno == EBUSY && c < 10) {
+                                (void) btrfs_quota_scan_wait(fd);
+                                continue;
+                        }
+
+                        return -errno;
+                }
+
+                break;
+        }
+
+        return 0;
+}
+
+int btrfs_qgroup_set_limit(const char *path, uint64_t qgroupid, uint64_t referenced_max) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_qgroup_set_limit_fd(fd, qgroupid, referenced_max);
+}
+
+int btrfs_subvol_set_subtree_quota_limit_fd(int fd, uint64_t subvol_id, uint64_t referenced_max) {
+        uint64_t qgroupid;
+        int r;
+
+        assert(fd >= 0);
+
+        r = btrfs_subvol_find_subtree_qgroup(fd, subvol_id, &qgroupid);
+        if (r < 0)
+                return r;
+
+        return btrfs_qgroup_set_limit_fd(fd, qgroupid, referenced_max);
+}
+
+int btrfs_subvol_set_subtree_quota_limit(const char *path, uint64_t subvol_id, uint64_t referenced_max) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_subvol_set_subtree_quota_limit_fd(fd, subvol_id, referenced_max);
+}
+
+int btrfs_qgroupid_make(uint64_t level, uint64_t id, uint64_t *ret) {
+        assert(ret);
+
+        if (level >= (UINT64_C(1) << (64 - BTRFS_QGROUP_LEVEL_SHIFT)))
+                return -EINVAL;
+
+        if (id >= (UINT64_C(1) << BTRFS_QGROUP_LEVEL_SHIFT))
+                return -EINVAL;
+
+        *ret = (level << BTRFS_QGROUP_LEVEL_SHIFT) | id;
+        return 0;
+}
+
+int btrfs_qgroupid_split(uint64_t qgroupid, uint64_t *level, uint64_t *id) {
+        assert(level || id);
+
+        if (level)
+                *level = qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT;
+
+        if (id)
+                *id = qgroupid & ((UINT64_C(1) << BTRFS_QGROUP_LEVEL_SHIFT) - 1);
+
+        return 0;
+}
+
+static int qgroup_create_or_destroy(int fd, bool b, uint64_t qgroupid) {
+
+        struct btrfs_ioctl_qgroup_create_args args = {
+                .create = b,
+                .qgroupid = qgroupid,
+        };
+        unsigned c;
+        int r;
+
+        r = btrfs_is_filesystem(fd);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ENOTTY;
+
+        for (c = 0;; c++) {
+                if (ioctl(fd, BTRFS_IOC_QGROUP_CREATE, &args) < 0) {
+
+                        /* If quota is not enabled, we get EINVAL. Turn this into a recognizable error */
+                        if (errno == EINVAL)
+                                return -ENOPROTOOPT;
+
+                        if (errno == EBUSY && c < 10) {
+                                (void) btrfs_quota_scan_wait(fd);
+                                continue;
+                        }
+
+                        return -errno;
+                }
+
+                break;
+        }
+
+        return 0;
+}
+
+int btrfs_qgroup_create(int fd, uint64_t qgroupid) {
+        return qgroup_create_or_destroy(fd, true, qgroupid);
+}
+
+int btrfs_qgroup_destroy(int fd, uint64_t qgroupid) {
+        return qgroup_create_or_destroy(fd, false, qgroupid);
+}
+
+int btrfs_qgroup_destroy_recursive(int fd, uint64_t qgroupid) {
+        _cleanup_free_ uint64_t *qgroups = NULL;
+        uint64_t subvol_id;
+        int i, n, r;
+
+        /* Destroys the specified qgroup, but unassigns it from all
+         * its parents first. Also, it recursively destroys all
+         * qgroups it is assigned to that have the same id part of the
+         * qgroupid as the specified group. */
+
+        r = btrfs_qgroupid_split(qgroupid, NULL, &subvol_id);
+        if (r < 0)
+                return r;
+
+        n = btrfs_qgroup_find_parents(fd, qgroupid, &qgroups);
+        if (n < 0)
+                return n;
+
+        for (i = 0; i < n; i++) {
+                uint64_t id;
+
+                r = btrfs_qgroupid_split(qgroups[i], NULL, &id);
+                if (r < 0)
+                        return r;
+
+                r = btrfs_qgroup_unassign(fd, qgroupid, qgroups[i]);
+                if (r < 0)
+                        return r;
+
+                if (id != subvol_id)
+                        continue;
+
+                /* The parent qgroupid shares the same id part with
+                 * us? If so, destroy it too. */
+
+                (void) btrfs_qgroup_destroy_recursive(fd, qgroups[i]);
+        }
+
+        return btrfs_qgroup_destroy(fd, qgroupid);
+}
+
+int btrfs_quota_scan_start(int fd) {
+        struct btrfs_ioctl_quota_rescan_args args = {};
+
+        assert(fd >= 0);
+
+        if (ioctl(fd, BTRFS_IOC_QUOTA_RESCAN, &args) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_quota_scan_wait(int fd) {
+        assert(fd >= 0);
+
+        if (ioctl(fd, BTRFS_IOC_QUOTA_RESCAN_WAIT) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int btrfs_quota_scan_ongoing(int fd) {
+        struct btrfs_ioctl_quota_rescan_args args = {};
+
+        assert(fd >= 0);
+
+        if (ioctl(fd, BTRFS_IOC_QUOTA_RESCAN_STATUS, &args) < 0)
+                return -errno;
+
+        return !!args.flags;
+}
+
+static int qgroup_assign_or_unassign(int fd, bool b, uint64_t child, uint64_t parent) {
+        struct btrfs_ioctl_qgroup_assign_args args = {
+                .assign = b,
+                .src = child,
+                .dst = parent,
+        };
+        unsigned c;
+        int r;
+
+        r = btrfs_is_filesystem(fd);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ENOTTY;
+
+        for (c = 0;; c++) {
+                r = ioctl(fd, BTRFS_IOC_QGROUP_ASSIGN, &args);
+                if (r < 0) {
+                        if (errno == EBUSY && c < 10) {
+                                (void) btrfs_quota_scan_wait(fd);
+                                continue;
+                        }
+
+                        return -errno;
+                }
+
+                if (r == 0)
+                        return 0;
+
+                /* If the return value is > 0, we need to request a rescan */
+
+                (void) btrfs_quota_scan_start(fd);
+                return 1;
+        }
+}
+
+int btrfs_qgroup_assign(int fd, uint64_t child, uint64_t parent) {
+        return qgroup_assign_or_unassign(fd, true, child, parent);
+}
+
+int btrfs_qgroup_unassign(int fd, uint64_t child, uint64_t parent) {
+        return qgroup_assign_or_unassign(fd, false, child, parent);
+}
+
+static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol_id, BtrfsRemoveFlags flags) {
+        struct btrfs_ioctl_search_args args = {
+                .key.tree_id = BTRFS_ROOT_TREE_OBJECTID,
+
+                .key.min_objectid = BTRFS_FIRST_FREE_OBJECTID,
+                .key.max_objectid = BTRFS_LAST_FREE_OBJECTID,
+
+                .key.min_type = BTRFS_ROOT_BACKREF_KEY,
+                .key.max_type = BTRFS_ROOT_BACKREF_KEY,
+
+                .key.min_transid = 0,
+                .key.max_transid = (uint64_t) -1,
+        };
+
+        struct btrfs_ioctl_vol_args vol_args = {};
+        _cleanup_close_ int subvol_fd = -1;
+        struct stat st;
+        bool made_writable = false;
+        int r;
+
+        assert(fd >= 0);
+        assert(subvolume);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (!S_ISDIR(st.st_mode))
+                return -EINVAL;
+
+        subvol_fd = openat(fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
+        if (subvol_fd < 0)
+                return -errno;
+
+        /* Let's check if this is actually a subvolume. Note that this is mostly redundant, as BTRFS_IOC_SNAP_DESTROY
+         * would fail anyway if it is not. However, it's a good thing to check this ahead of time so that we can return
+         * ENOTTY unconditionally in this case. This is different from the ioctl() which will return EPERM/EACCES if we
+         * don't have the privileges to remove subvolumes, regardless if the specified directory is actually a
+         * subvolume or not. In order to make it easy for callers to cover the "this is not a btrfs subvolume" case
+         * let's prefer ENOTTY over EPERM/EACCES though. */
+        r = btrfs_is_subvol_fd(subvol_fd);
+        if (r < 0)
+                return r;
+        if (r == 0) /* Not a btrfs subvolume */
+                return -ENOTTY;
+
+        if (subvol_id == 0) {
+                r = btrfs_subvol_get_id_fd(subvol_fd, &subvol_id);
+                if (r < 0)
+                        return r;
+        }
+
+        /* First, try to remove the subvolume. If it happens to be
+         * already empty, this will just work. */
+        strncpy(vol_args.name, subvolume, sizeof(vol_args.name)-1);
+        if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) >= 0) {
+                (void) btrfs_qgroup_destroy_recursive(fd, subvol_id); /* for the leaf subvolumes, the qgroup id is identical to the subvol id */
+                return 0;
+        }
+        if (!(flags & BTRFS_REMOVE_RECURSIVE) || errno != ENOTEMPTY)
+                return -errno;
+
+        /* OK, the subvolume is not empty, let's look for child
+         * subvolumes, and remove them, first */
+
+        args.key.min_offset = args.key.max_offset = subvol_id;
+
+        while (btrfs_ioctl_search_args_compare(&args) <= 0) {
+                const struct btrfs_ioctl_search_header *sh;
+                unsigned i;
+
+                args.key.nr_items = 256;
+                if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
+                        return -errno;
+
+                if (args.key.nr_items <= 0)
+                        break;
+
+                FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
+                        _cleanup_free_ char *p = NULL;
+                        const struct btrfs_root_ref *ref;
+                        struct btrfs_ioctl_ino_lookup_args ino_args;
+
+                        btrfs_ioctl_search_args_set(&args, sh);
+
+                        if (sh->type != BTRFS_ROOT_BACKREF_KEY)
+                                continue;
+                        if (sh->offset != subvol_id)
+                                continue;
+
+                        ref = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh);
+
+                        p = strndup((char*) ref + sizeof(struct btrfs_root_ref), le64toh(ref->name_len));
+                        if (!p)
+                                return -ENOMEM;
+
+                        zero(ino_args);
+                        ino_args.treeid = subvol_id;
+                        ino_args.objectid = htole64(ref->dirid);
+
+                        if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0)
+                                return -errno;
+
+                        if (!made_writable) {
+                                r = btrfs_subvol_set_read_only_fd(subvol_fd, false);
+                                if (r < 0)
+                                        return r;
+
+                                made_writable = true;
+                        }
+
+                        if (isempty(ino_args.name))
+                                /* Subvolume is in the top-level
+                                 * directory of the subvolume. */
+                                r = subvol_remove_children(subvol_fd, p, sh->objectid, flags);
+                        else {
+                                _cleanup_close_ int child_fd = -1;
+
+                                /* Subvolume is somewhere further down,
+                                 * hence we need to open the
+                                 * containing directory first */
+
+                                child_fd = openat(subvol_fd, ino_args.name, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
+                                if (child_fd < 0)
+                                        return -errno;
+
+                                r = subvol_remove_children(child_fd, p, sh->objectid, flags);
+                        }
+                        if (r < 0)
+                                return r;
+                }
+
+                /* Increase search key by one, to read the next item, if we can. */
+                if (!btrfs_ioctl_search_args_inc(&args))
+                        break;
+        }
+
+        /* OK, the child subvolumes should all be gone now, let's try
+         * again to remove the subvolume */
+        if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) < 0)
+                return -errno;
+
+        (void) btrfs_qgroup_destroy_recursive(fd, subvol_id);
+        return 0;
+}
+
+int btrfs_subvol_remove(const char *path, BtrfsRemoveFlags flags) {
+        _cleanup_close_ int fd = -1;
+        const char *subvolume;
+        int r;
+
+        assert(path);
+
+        r = extract_subvolume_name(path, &subvolume);
+        if (r < 0)
+                return r;
+
+        fd = open_parent(path, O_CLOEXEC, 0);
+        if (fd < 0)
+                return fd;
+
+        return subvol_remove_children(fd, subvolume, 0, flags);
+}
+
+int btrfs_subvol_remove_fd(int fd, const char *subvolume, BtrfsRemoveFlags flags) {
+        return subvol_remove_children(fd, subvolume, 0, flags);
+}
+
+int btrfs_qgroup_copy_limits(int fd, uint64_t old_qgroupid, uint64_t new_qgroupid) {
+
+        struct btrfs_ioctl_search_args args = {
+                /* Tree of quota items */
+                .key.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+
+                /* The object ID is always 0 */
+                .key.min_objectid = 0,
+                .key.max_objectid = 0,
+
+                /* Look precisely for the quota items */
+                .key.min_type = BTRFS_QGROUP_LIMIT_KEY,
+                .key.max_type = BTRFS_QGROUP_LIMIT_KEY,
+
+                /* For our qgroup */
+                .key.min_offset = old_qgroupid,
+                .key.max_offset = old_qgroupid,
+
+                /* No restrictions on the other components */
+                .key.min_transid = 0,
+                .key.max_transid = (uint64_t) -1,
+        };
+
+        int r;
+
+        r = btrfs_is_filesystem(fd);
+        if (r < 0)
+                return r;
+        if (!r)
+                return -ENOTTY;
+
+        while (btrfs_ioctl_search_args_compare(&args) <= 0) {
+                const struct btrfs_ioctl_search_header *sh;
+                unsigned i;
+
+                args.key.nr_items = 256;
+                if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) {
+                        if (errno == ENOENT) /* quota tree missing: quota is not enabled, hence nothing to copy */
+                                break;
+
+                        return -errno;
+                }
+
+                if (args.key.nr_items <= 0)
+                        break;
+
+                FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
+                        const struct btrfs_qgroup_limit_item *qli = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh);
+                        struct btrfs_ioctl_qgroup_limit_args qargs;
+                        unsigned c;
+
+                        /* Make sure we start the next search at least from this entry */
+                        btrfs_ioctl_search_args_set(&args, sh);
+
+                        if (sh->objectid != 0)
+                                continue;
+                        if (sh->type != BTRFS_QGROUP_LIMIT_KEY)
+                                continue;
+                        if (sh->offset != old_qgroupid)
+                                continue;
+
+                        /* We found the entry, now copy things over. */
+
+                        qargs = (struct btrfs_ioctl_qgroup_limit_args) {
+                                .qgroupid = new_qgroupid,
+
+                                .lim.max_rfer = le64toh(qli->max_rfer),
+                                .lim.max_excl = le64toh(qli->max_excl),
+                                .lim.rsv_rfer = le64toh(qli->rsv_rfer),
+                                .lim.rsv_excl = le64toh(qli->rsv_excl),
+
+                                .lim.flags = le64toh(qli->flags) & (BTRFS_QGROUP_LIMIT_MAX_RFER|
+                                                                    BTRFS_QGROUP_LIMIT_MAX_EXCL|
+                                                                    BTRFS_QGROUP_LIMIT_RSV_RFER|
+                                                                    BTRFS_QGROUP_LIMIT_RSV_EXCL),
+                        };
+
+                        for (c = 0;; c++) {
+                                if (ioctl(fd, BTRFS_IOC_QGROUP_LIMIT, &qargs) < 0) {
+                                        if (errno == EBUSY && c < 10) {
+                                                (void) btrfs_quota_scan_wait(fd);
+                                                continue;
+                                        }
+                                        return -errno;
+                                }
+
+                                break;
+                        }
+
+                        return 1;
+                }
+
+                /* Increase search key by one, to read the next item, if we can. */
+                if (!btrfs_ioctl_search_args_inc(&args))
+                        break;
+        }
+
+        return 0;
+}
+
+static int copy_quota_hierarchy(int fd, uint64_t old_subvol_id, uint64_t new_subvol_id) {
+        _cleanup_free_ uint64_t *old_qgroups = NULL, *old_parent_qgroups = NULL;
+        bool copy_from_parent = false, insert_intermediary_qgroup = false;
+        int n_old_qgroups, n_old_parent_qgroups, r, i;
+        uint64_t old_parent_id;
+
+        assert(fd >= 0);
+
+        /* Copies a reduced form of quota information from the old to
+         * the new subvolume. */
+
+        n_old_qgroups = btrfs_qgroup_find_parents(fd, old_subvol_id, &old_qgroups);
+        if (n_old_qgroups <= 0) /* Nothing to copy */
+                return n_old_qgroups;
+
+        r = btrfs_subvol_get_parent(fd, old_subvol_id, &old_parent_id);
+        if (r == -ENXIO)
+                /* We have no parent, hence nothing to copy. */
+                n_old_parent_qgroups = 0;
+        else if (r < 0)
+                return r;
+        else {
+                n_old_parent_qgroups = btrfs_qgroup_find_parents(fd, old_parent_id, &old_parent_qgroups);
+                if (n_old_parent_qgroups < 0)
+                        return n_old_parent_qgroups;
+        }
+
+        for (i = 0; i < n_old_qgroups; i++) {
+                uint64_t id;
+                int j;
+
+                r = btrfs_qgroupid_split(old_qgroups[i], NULL, &id);
+                if (r < 0)
+                        return r;
+
+                if (id == old_subvol_id) {
+                        /* The old subvolume was member of a qgroup
+                         * that had the same id, but a different level
+                         * as it self. Let's set up something similar
+                         * in the destination. */
+                        insert_intermediary_qgroup = true;
+                        break;
+                }
+
+                for (j = 0; j < n_old_parent_qgroups; j++)
+                        if (old_parent_qgroups[j] == old_qgroups[i]) {
+                                /* The old subvolume shared a common
+                                 * parent qgroup with its parent
+                                 * subvolume. Let's set up something
+                                 * similar in the destination. */
+                                copy_from_parent = true;
+                        }
+        }
+
+        if (!insert_intermediary_qgroup && !copy_from_parent)
+                return 0;
+
+        return btrfs_subvol_auto_qgroup_fd(fd, new_subvol_id, insert_intermediary_qgroup);
+}
+
+static int copy_subtree_quota_limits(int fd, uint64_t old_subvol, uint64_t new_subvol) {
+        uint64_t old_subtree_qgroup, new_subtree_qgroup;
+        bool changed;
+        int r;
+
+        /* First copy the leaf limits */
+        r = btrfs_qgroup_copy_limits(fd, old_subvol, new_subvol);
+        if (r < 0)
+                return r;
+        changed = r > 0;
+
+        /* Then, try to copy the subtree limits, if there are any. */
+        r = btrfs_subvol_find_subtree_qgroup(fd, old_subvol, &old_subtree_qgroup);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return changed;
+
+        r = btrfs_subvol_find_subtree_qgroup(fd, new_subvol, &new_subtree_qgroup);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return changed;
+
+        r = btrfs_qgroup_copy_limits(fd, old_subtree_qgroup, new_subtree_qgroup);
+        if (r != 0)
+                return r;
+
+        return changed;
+}
+
+static int subvol_snapshot_children(
+                int old_fd,
+                int new_fd,
+                const char *subvolume,
+                uint64_t old_subvol_id,
+                BtrfsSnapshotFlags flags) {
+
+        struct btrfs_ioctl_search_args args = {
+                .key.tree_id = BTRFS_ROOT_TREE_OBJECTID,
+
+                .key.min_objectid = BTRFS_FIRST_FREE_OBJECTID,
+                .key.max_objectid = BTRFS_LAST_FREE_OBJECTID,
+
+                .key.min_type = BTRFS_ROOT_BACKREF_KEY,
+                .key.max_type = BTRFS_ROOT_BACKREF_KEY,
+
+                .key.min_transid = 0,
+                .key.max_transid = (uint64_t) -1,
+        };
+
+        struct btrfs_ioctl_vol_args_v2 vol_args = {
+                .flags = flags & BTRFS_SNAPSHOT_READ_ONLY ? BTRFS_SUBVOL_RDONLY : 0,
+                .fd = old_fd,
+        };
+        _cleanup_close_ int subvolume_fd = -1;
+        uint64_t new_subvol_id;
+        int r;
+
+        assert(old_fd >= 0);
+        assert(new_fd >= 0);
+        assert(subvolume);
+
+        strncpy(vol_args.name, subvolume, sizeof(vol_args.name)-1);
+
+        if (ioctl(new_fd, BTRFS_IOC_SNAP_CREATE_V2, &vol_args) < 0)
+                return -errno;
+
+        if (!(flags & BTRFS_SNAPSHOT_RECURSIVE) &&
+            !(flags & BTRFS_SNAPSHOT_QUOTA))
+                return 0;
+
+        if (old_subvol_id == 0) {
+                r = btrfs_subvol_get_id_fd(old_fd, &old_subvol_id);
+                if (r < 0)
+                        return r;
+        }
+
+        r = btrfs_subvol_get_id(new_fd, vol_args.name, &new_subvol_id);
+        if (r < 0)
+                return r;
+
+        if (flags & BTRFS_SNAPSHOT_QUOTA)
+                (void) copy_quota_hierarchy(new_fd, old_subvol_id, new_subvol_id);
+
+        if (!(flags & BTRFS_SNAPSHOT_RECURSIVE)) {
+
+                if (flags & BTRFS_SNAPSHOT_QUOTA)
+                        (void) copy_subtree_quota_limits(new_fd, old_subvol_id, new_subvol_id);
+
+                return 0;
+        }
+
+        args.key.min_offset = args.key.max_offset = old_subvol_id;
+
+        while (btrfs_ioctl_search_args_compare(&args) <= 0) {
+                const struct btrfs_ioctl_search_header *sh;
+                unsigned i;
+
+                args.key.nr_items = 256;
+                if (ioctl(old_fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
+                        return -errno;
+
+                if (args.key.nr_items <= 0)
+                        break;
+
+                FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
+                        _cleanup_free_ char *p = NULL, *c = NULL, *np = NULL;
+                        struct btrfs_ioctl_ino_lookup_args ino_args;
+                        const struct btrfs_root_ref *ref;
+                        _cleanup_close_ int old_child_fd = -1, new_child_fd = -1;
+
+                        btrfs_ioctl_search_args_set(&args, sh);
+
+                        if (sh->type != BTRFS_ROOT_BACKREF_KEY)
+                                continue;
+
+                        /* Avoid finding the source subvolume a second
+                         * time */
+                        if (sh->offset != old_subvol_id)
+                                continue;
+
+                        /* Avoid running into loops if the new
+                         * subvolume is below the old one. */
+                        if (sh->objectid == new_subvol_id)
+                                continue;
+
+                        ref = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh);
+                        p = strndup((char*) ref + sizeof(struct btrfs_root_ref), le64toh(ref->name_len));
+                        if (!p)
+                                return -ENOMEM;
+
+                        zero(ino_args);
+                        ino_args.treeid = old_subvol_id;
+                        ino_args.objectid = htole64(ref->dirid);
+
+                        if (ioctl(old_fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0)
+                                return -errno;
+
+                        /* The kernel returns an empty name if the
+                         * subvolume is in the top-level directory,
+                         * and otherwise appends a slash, so that we
+                         * can just concatenate easily here, without
+                         * adding a slash. */
+                        c = strappend(ino_args.name, p);
+                        if (!c)
+                                return -ENOMEM;
+
+                        old_child_fd = openat(old_fd, c, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
+                        if (old_child_fd < 0)
+                                return -errno;
+
+                        np = strjoin(subvolume, "/", ino_args.name);
+                        if (!np)
+                                return -ENOMEM;
+
+                        new_child_fd = openat(new_fd, np, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
+                        if (new_child_fd < 0)
+                                return -errno;
+
+                        if (flags & BTRFS_SNAPSHOT_READ_ONLY) {
+                                /* If the snapshot is read-only we
+                                 * need to mark it writable
+                                 * temporarily, to put the subsnapshot
+                                 * into place. */
+
+                                if (subvolume_fd < 0) {
+                                        subvolume_fd = openat(new_fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
+                                        if (subvolume_fd < 0)
+                                                return -errno;
+                                }
+
+                                r = btrfs_subvol_set_read_only_fd(subvolume_fd, false);
+                                if (r < 0)
+                                        return r;
+                        }
+
+                        /* When btrfs clones the subvolumes, child
+                         * subvolumes appear as empty directories. Remove
+                         * them, so that we can create a new snapshot
+                         * in their place */
+                        if (unlinkat(new_child_fd, p, AT_REMOVEDIR) < 0) {
+                                int k = -errno;
+
+                                if (flags & BTRFS_SNAPSHOT_READ_ONLY)
+                                        (void) btrfs_subvol_set_read_only_fd(subvolume_fd, true);
+
+                                return k;
+                        }
+
+                        r = subvol_snapshot_children(old_child_fd, new_child_fd, p, sh->objectid, flags & ~BTRFS_SNAPSHOT_FALLBACK_COPY);
+
+                        /* Restore the readonly flag */
+                        if (flags & BTRFS_SNAPSHOT_READ_ONLY) {
+                                int k;
+
+                                k = btrfs_subvol_set_read_only_fd(subvolume_fd, true);
+                                if (r >= 0 && k < 0)
+                                        return k;
+                        }
+
+                        if (r < 0)
+                                return r;
+                }
+
+                /* Increase search key by one, to read the next item, if we can. */
+                if (!btrfs_ioctl_search_args_inc(&args))
+                        break;
+        }
+
+        if (flags & BTRFS_SNAPSHOT_QUOTA)
+                (void) copy_subtree_quota_limits(new_fd, old_subvol_id, new_subvol_id);
+
+        return 0;
+}
+
+int btrfs_subvol_snapshot_fd_full(
+                int old_fd,
+                const char *new_path,
+                BtrfsSnapshotFlags flags,
+                copy_progress_path_t progress_path,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        _cleanup_close_ int new_fd = -1;
+        const char *subvolume;
+        int r;
+
+        assert(old_fd >= 0);
+        assert(new_path);
+
+        r = btrfs_is_subvol_fd(old_fd);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                bool plain_directory = false;
+
+                /* If the source isn't a proper subvolume, fail unless fallback is requested */
+                if (!(flags & BTRFS_SNAPSHOT_FALLBACK_COPY))
+                        return -EISDIR;
+
+                r = btrfs_subvol_make(new_path);
+                if (r == -ENOTTY && (flags & BTRFS_SNAPSHOT_FALLBACK_DIRECTORY)) {
+                        /* If the destination doesn't support subvolumes, then use a plain directory, if that's requested. */
+                        if (mkdir(new_path, 0755) < 0)
+                                return -errno;
+
+                        plain_directory = true;
+                } else if (r < 0)
+                        return r;
+
+                r = copy_directory_fd_full(old_fd, new_path, COPY_MERGE|COPY_REFLINK, progress_path, progress_bytes, userdata);
+                if (r < 0)
+                        goto fallback_fail;
+
+                if (flags & BTRFS_SNAPSHOT_READ_ONLY) {
+
+                        if (plain_directory) {
+                                /* Plain directories have no recursive read-only flag, but something pretty close to
+                                 * it: the IMMUTABLE bit. Let's use this here, if this is requested. */
+
+                                if (flags & BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE)
+                                        (void) chattr_path(new_path, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL, NULL);
+                        } else {
+                                r = btrfs_subvol_set_read_only(new_path, true);
+                                if (r < 0)
+                                        goto fallback_fail;
+                        }
+                }
+
+                return 0;
+
+        fallback_fail:
+                (void) rm_rf(new_path, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
+                return r;
+        }
+
+        r = extract_subvolume_name(new_path, &subvolume);
+        if (r < 0)
+                return r;
+
+        new_fd = open_parent(new_path, O_CLOEXEC, 0);
+        if (new_fd < 0)
+                return new_fd;
+
+        return subvol_snapshot_children(old_fd, new_fd, subvolume, 0, flags);
+}
+
+int btrfs_subvol_snapshot_full(
+                const char *old_path,
+                const char *new_path,
+                BtrfsSnapshotFlags flags,
+                copy_progress_path_t progress_path,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        _cleanup_close_ int old_fd = -1;
+
+        assert(old_path);
+        assert(new_path);
+
+        old_fd = open(old_path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+        if (old_fd < 0)
+                return -errno;
+
+        return btrfs_subvol_snapshot_fd_full(old_fd, new_path, flags, progress_path, progress_bytes, userdata);
+}
+
+int btrfs_qgroup_find_parents(int fd, uint64_t qgroupid, uint64_t **ret) {
+
+        struct btrfs_ioctl_search_args args = {
+                /* Tree of quota items */
+                .key.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
+
+                /* Look precisely for the quota relation items */
+                .key.min_type = BTRFS_QGROUP_RELATION_KEY,
+                .key.max_type = BTRFS_QGROUP_RELATION_KEY,
+
+                /* No restrictions on the other components */
+                .key.min_offset = 0,
+                .key.max_offset = (uint64_t) -1,
+
+                .key.min_transid = 0,
+                .key.max_transid = (uint64_t) -1,
+        };
+
+        _cleanup_free_ uint64_t *items = NULL;
+        size_t n_items = 0, n_allocated = 0;
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        if (qgroupid == 0) {
+                r = btrfs_subvol_get_id_fd(fd, &qgroupid);
+                if (r < 0)
+                        return r;
+        } else {
+                r = btrfs_is_filesystem(fd);
+                if (r < 0)
+                        return r;
+                if (!r)
+                        return -ENOTTY;
+        }
+
+        args.key.min_objectid = args.key.max_objectid = qgroupid;
+
+        while (btrfs_ioctl_search_args_compare(&args) <= 0) {
+                const struct btrfs_ioctl_search_header *sh;
+                unsigned i;
+
+                args.key.nr_items = 256;
+                if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) {
+                        if (errno == ENOENT) /* quota tree missing: quota is disabled */
+                                break;
+
+                        return -errno;
+                }
+
+                if (args.key.nr_items <= 0)
+                        break;
+
+                FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
+
+                        /* Make sure we start the next search at least from this entry */
+                        btrfs_ioctl_search_args_set(&args, sh);
+
+                        if (sh->type != BTRFS_QGROUP_RELATION_KEY)
+                                continue;
+                        if (sh->offset < sh->objectid)
+                                continue;
+                        if (sh->objectid != qgroupid)
+                                continue;
+
+                        if (!GREEDY_REALLOC(items, n_allocated, n_items+1))
+                                return -ENOMEM;
+
+                        items[n_items++] = sh->offset;
+                }
+
+                /* Increase search key by one, to read the next item, if we can. */
+                if (!btrfs_ioctl_search_args_inc(&args))
+                        break;
+        }
+
+        if (n_items <= 0) {
+                *ret = NULL;
+                return 0;
+        }
+
+        *ret = TAKE_PTR(items);
+
+        return (int) n_items;
+}
+
+int btrfs_subvol_auto_qgroup_fd(int fd, uint64_t subvol_id, bool insert_intermediary_qgroup) {
+        _cleanup_free_ uint64_t *qgroups = NULL;
+        uint64_t parent_subvol;
+        bool changed = false;
+        int n = 0, r;
+
+        assert(fd >= 0);
+
+        /*
+         * Sets up the specified subvolume's qgroup automatically in
+         * one of two ways:
+         *
+         * If insert_intermediary_qgroup is false, the subvolume's
+         * leaf qgroup will be assigned to the same parent qgroups as
+         * the subvolume's parent subvolume.
+         *
+         * If insert_intermediary_qgroup is true a new intermediary
+         * higher-level qgroup is created, with a higher level number,
+         * but reusing the id of the subvolume. The level number is
+         * picked as one smaller than the lowest level qgroup the
+         * parent subvolume is a member of. If the parent subvolume's
+         * leaf qgroup is assigned to no higher-level qgroup a new
+         * qgroup of level 255 is created instead. Either way, the new
+         * qgroup is then assigned to the parent's higher-level
+         * qgroup, and the subvolume itself is assigned to it.
+         *
+         * If the subvolume is already assigned to a higher level
+         * qgroup, no operation is executed.
+         *
+         * Effectively this means: regardless if
+         * insert_intermediary_qgroup is true or not, after this
+         * function is invoked the subvolume will be accounted within
+         * the same qgroups as the parent. However, if it is true, it
+         * will also get its own higher-level qgroup, which may in
+         * turn be used by subvolumes created beneath this subvolume
+         * later on.
+         *
+         * This hence defines a simple default qgroup setup for
+         * subvolumes, as long as this function is invoked on each
+         * created subvolume: each subvolume is always accounting
+         * together with its immediate parents. Optionally, if
+         * insert_intermediary_qgroup is true, it will also get a
+         * qgroup that then includes all its own child subvolumes.
+         */
+
+        if (subvol_id == 0) {
+                r = btrfs_is_subvol_fd(fd);
+                if (r < 0)
+                        return r;
+                if (!r)
+                        return -ENOTTY;
+
+                r = btrfs_subvol_get_id_fd(fd, &subvol_id);
+                if (r < 0)
+                        return r;
+        }
+
+        n = btrfs_qgroup_find_parents(fd, subvol_id, &qgroups);
+        if (n < 0)
+                return n;
+        if (n > 0) /* already parent qgroups set up, let's bail */
+                return 0;
+
+        qgroups = mfree(qgroups);
+
+        r = btrfs_subvol_get_parent(fd, subvol_id, &parent_subvol);
+        if (r == -ENXIO)
+                /* No parent, hence no qgroup memberships */
+                n = 0;
+        else if (r < 0)
+                return r;
+        else {
+                n = btrfs_qgroup_find_parents(fd, parent_subvol, &qgroups);
+                if (n < 0)
+                        return n;
+        }
+
+        if (insert_intermediary_qgroup) {
+                uint64_t lowest = 256, new_qgroupid;
+                bool created = false;
+                int i;
+
+                /* Determine the lowest qgroup that the parent
+                 * subvolume is assigned to. */
+
+                for (i = 0; i < n; i++) {
+                        uint64_t level;
+
+                        r = btrfs_qgroupid_split(qgroups[i], &level, NULL);
+                        if (r < 0)
+                                return r;
+
+                        if (level < lowest)
+                                lowest = level;
+                }
+
+                if (lowest <= 1) /* There are no levels left we could use insert an intermediary qgroup at */
+                        return -EBUSY;
+
+                r = btrfs_qgroupid_make(lowest - 1, subvol_id, &new_qgroupid);
+                if (r < 0)
+                        return r;
+
+                /* Create the new intermediary group, unless it already exists */
+                r = btrfs_qgroup_create(fd, new_qgroupid);
+                if (r < 0 && r != -EEXIST)
+                        return r;
+                if (r >= 0)
+                        changed = created = true;
+
+                for (i = 0; i < n; i++) {
+                        r = btrfs_qgroup_assign(fd, new_qgroupid, qgroups[i]);
+                        if (r < 0 && r != -EEXIST) {
+                                if (created)
+                                        (void) btrfs_qgroup_destroy_recursive(fd, new_qgroupid);
+
+                                return r;
+                        }
+                        if (r >= 0)
+                                changed = true;
+                }
+
+                r = btrfs_qgroup_assign(fd, subvol_id, new_qgroupid);
+                if (r < 0 && r != -EEXIST) {
+                        if (created)
+                                (void) btrfs_qgroup_destroy_recursive(fd, new_qgroupid);
+                        return r;
+                }
+                if (r >= 0)
+                        changed = true;
+
+        } else {
+                int i;
+
+                /* Assign our subvolume to all the same qgroups as the parent */
+
+                for (i = 0; i < n; i++) {
+                        r = btrfs_qgroup_assign(fd, subvol_id, qgroups[i]);
+                        if (r < 0 && r != -EEXIST)
+                                return r;
+                        if (r >= 0)
+                                changed = true;
+                }
+        }
+
+        return changed;
+}
+
+int btrfs_subvol_auto_qgroup(const char *path, uint64_t subvol_id, bool create_intermediary_qgroup) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_subvol_auto_qgroup_fd(fd, subvol_id, create_intermediary_qgroup);
+}
+
+int btrfs_subvol_get_parent(int fd, uint64_t subvol_id, uint64_t *ret) {
+
+        struct btrfs_ioctl_search_args args = {
+                /* Tree of tree roots */
+                .key.tree_id = BTRFS_ROOT_TREE_OBJECTID,
+
+                /* Look precisely for the subvolume items */
+                .key.min_type = BTRFS_ROOT_BACKREF_KEY,
+                .key.max_type = BTRFS_ROOT_BACKREF_KEY,
+
+                /* No restrictions on the other components */
+                .key.min_offset = 0,
+                .key.max_offset = (uint64_t) -1,
+
+                .key.min_transid = 0,
+                .key.max_transid = (uint64_t) -1,
+        };
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        if (subvol_id == 0) {
+                r = btrfs_subvol_get_id_fd(fd, &subvol_id);
+                if (r < 0)
+                        return r;
+        } else {
+                r = btrfs_is_filesystem(fd);
+                if (r < 0)
+                        return r;
+                if (!r)
+                        return -ENOTTY;
+        }
+
+        args.key.min_objectid = args.key.max_objectid = subvol_id;
+
+        while (btrfs_ioctl_search_args_compare(&args) <= 0) {
+                const struct btrfs_ioctl_search_header *sh;
+                unsigned i;
+
+                args.key.nr_items = 256;
+                if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
+                        return negative_errno();
+
+                if (args.key.nr_items <= 0)
+                        break;
+
+                FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
+
+                        if (sh->type != BTRFS_ROOT_BACKREF_KEY)
+                                continue;
+                        if (sh->objectid != subvol_id)
+                                continue;
+
+                        *ret = sh->offset;
+                        return 0;
+                }
+        }
+
+        return -ENXIO;
+}
diff --git a/src/basic/btrfs-util.h b/src/basic/btrfs-util.h
new file mode 100644
index 0000000..7d848a7
--- /dev/null
+++ b/src/basic/btrfs-util.h
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "sd-id128.h"
+
+#include "copy.h"
+#include "time-util.h"
+
+typedef struct BtrfsSubvolInfo {
+        uint64_t subvol_id;
+        usec_t otime;
+
+        sd_id128_t uuid;
+        sd_id128_t parent_uuid;
+
+        bool read_only;
+} BtrfsSubvolInfo;
+
+typedef struct BtrfsQuotaInfo {
+        uint64_t referenced;
+        uint64_t exclusive;
+        uint64_t referenced_max;
+        uint64_t exclusive_max;
+} BtrfsQuotaInfo;
+
+typedef enum BtrfsSnapshotFlags {
+        BTRFS_SNAPSHOT_FALLBACK_COPY      = 1 << 0, /* If the source isn't a subvolume, reflink everything */
+        BTRFS_SNAPSHOT_READ_ONLY          = 1 << 1,
+        BTRFS_SNAPSHOT_RECURSIVE          = 1 << 2,
+        BTRFS_SNAPSHOT_QUOTA              = 1 << 3,
+        BTRFS_SNAPSHOT_FALLBACK_DIRECTORY = 1 << 4, /* If the destination doesn't support subvolumes, reflink/copy instead */
+        BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE = 1 << 5, /* When we can't create a subvolume, use the FS_IMMUTABLE attribute for indicating read-only */
+} BtrfsSnapshotFlags;
+
+typedef enum BtrfsRemoveFlags {
+        BTRFS_REMOVE_RECURSIVE = 1 << 0,
+        BTRFS_REMOVE_QUOTA     = 1 << 1,
+} BtrfsRemoveFlags;
+
+int btrfs_is_filesystem(int fd);
+
+int btrfs_is_subvol_fd(int fd);
+int btrfs_is_subvol(const char *path);
+
+int btrfs_reflink(int infd, int outfd);
+int btrfs_clone_range(int infd, uint64_t in_offset, int ofd, uint64_t out_offset, uint64_t sz);
+
+int btrfs_get_block_device_fd(int fd, dev_t *dev);
+int btrfs_get_block_device(const char *path, dev_t *dev);
+
+int btrfs_defrag_fd(int fd);
+int btrfs_defrag(const char *p);
+
+int btrfs_quota_enable_fd(int fd, bool b);
+int btrfs_quota_enable(const char *path, bool b);
+
+int btrfs_quota_scan_start(int fd);
+int btrfs_quota_scan_wait(int fd);
+int btrfs_quota_scan_ongoing(int fd);
+
+int btrfs_subvol_make(const char *path);
+int btrfs_subvol_make_fd(int fd, const char *subvolume);
+
+int btrfs_subvol_snapshot_fd_full(int old_fd, const char *new_path, BtrfsSnapshotFlags flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata);
+static inline int btrfs_subvol_snapshot_fd(int old_fd, const char *new_path, BtrfsSnapshotFlags flags) {
+        return btrfs_subvol_snapshot_fd_full(old_fd, new_path, flags, NULL, NULL, NULL);
+}
+
+int btrfs_subvol_snapshot_full(const char *old_path, const char *new_path, BtrfsSnapshotFlags flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata);
+static inline int btrfs_subvol_snapshot(const char *old_path, const char *new_path, BtrfsSnapshotFlags flags) {
+        return btrfs_subvol_snapshot_full(old_path, new_path, flags, NULL, NULL, NULL);
+}
+
+int btrfs_subvol_remove(const char *path, BtrfsRemoveFlags flags);
+int btrfs_subvol_remove_fd(int fd, const char *subvolume, BtrfsRemoveFlags flags);
+
+int btrfs_subvol_set_read_only_fd(int fd, bool b);
+int btrfs_subvol_set_read_only(const char *path, bool b);
+int btrfs_subvol_get_read_only_fd(int fd);
+
+int btrfs_subvol_get_id(int fd, const char *subvolume, uint64_t *ret);
+int btrfs_subvol_get_id_fd(int fd, uint64_t *ret);
+int btrfs_subvol_get_parent(int fd, uint64_t subvol_id, uint64_t *ret);
+
+int btrfs_subvol_get_info_fd(int fd, uint64_t subvol_id, BtrfsSubvolInfo *info);
+
+int btrfs_subvol_find_subtree_qgroup(int fd, uint64_t subvol_id, uint64_t *ret);
+
+int btrfs_subvol_get_subtree_quota(const char *path, uint64_t subvol_id, BtrfsQuotaInfo *quota);
+int btrfs_subvol_get_subtree_quota_fd(int fd, uint64_t subvol_id, BtrfsQuotaInfo *quota);
+
+int btrfs_subvol_set_subtree_quota_limit(const char *path, uint64_t subvol_id, uint64_t referenced_max);
+int btrfs_subvol_set_subtree_quota_limit_fd(int fd, uint64_t subvol_id, uint64_t referenced_max);
+
+int btrfs_subvol_auto_qgroup_fd(int fd, uint64_t subvol_id, bool new_qgroup);
+int btrfs_subvol_auto_qgroup(const char *path, uint64_t subvol_id, bool create_intermediary_qgroup);
+
+int btrfs_qgroupid_make(uint64_t level, uint64_t id, uint64_t *ret);
+int btrfs_qgroupid_split(uint64_t qgroupid, uint64_t *level, uint64_t *id);
+
+int btrfs_qgroup_create(int fd, uint64_t qgroupid);
+int btrfs_qgroup_destroy(int fd, uint64_t qgroupid);
+int btrfs_qgroup_destroy_recursive(int fd, uint64_t qgroupid);
+
+int btrfs_qgroup_set_limit_fd(int fd, uint64_t qgroupid, uint64_t referenced_max);
+int btrfs_qgroup_set_limit(const char *path, uint64_t qgroupid, uint64_t referenced_max);
+
+int btrfs_qgroup_copy_limits(int fd, uint64_t old_qgroupid, uint64_t new_qgroupid);
+
+int btrfs_qgroup_assign(int fd, uint64_t child, uint64_t parent);
+int btrfs_qgroup_unassign(int fd, uint64_t child, uint64_t parent);
+
+int btrfs_qgroup_find_parents(int fd, uint64_t qgroupid, uint64_t **ret);
+
+int btrfs_qgroup_get_quota_fd(int fd, uint64_t qgroupid, BtrfsQuotaInfo *quota);
+int btrfs_qgroup_get_quota(const char *path, uint64_t qgroupid, BtrfsQuotaInfo *quota);
diff --git a/src/basic/build.h b/src/basic/build.h
new file mode 100644
index 0000000..7a59059
--- /dev/null
+++ b/src/basic/build.h
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "version.h"
+
+#if HAVE_PAM
+#define _PAM_FEATURE_ "+PAM"
+#else
+#define _PAM_FEATURE_ "-PAM"
+#endif
+
+#if HAVE_AUDIT
+#define _AUDIT_FEATURE_ "+AUDIT"
+#else
+#define _AUDIT_FEATURE_ "-AUDIT"
+#endif
+
+#if HAVE_SELINUX
+#define _SELINUX_FEATURE_ "+SELINUX"
+#else
+#define _SELINUX_FEATURE_ "-SELINUX"
+#endif
+
+#if HAVE_APPARMOR
+#define _APPARMOR_FEATURE_ "+APPARMOR"
+#else
+#define _APPARMOR_FEATURE_ "-APPARMOR"
+#endif
+
+#if ENABLE_IMA
+#define _IMA_FEATURE_ "+IMA"
+#else
+#define _IMA_FEATURE_ "-IMA"
+#endif
+
+#if ENABLE_SMACK
+#define _SMACK_FEATURE_ "+SMACK"
+#else
+#define _SMACK_FEATURE_ "-SMACK"
+#endif
+
+#if HAVE_SYSV_COMPAT
+#define _SYSVINIT_FEATURE_ "+SYSVINIT"
+#else
+#define _SYSVINIT_FEATURE_ "-SYSVINIT"
+#endif
+
+#if ENABLE_UTMP
+#define _UTMP_FEATURE_ "+UTMP"
+#else
+#define _UTMP_FEATURE_ "-UTMP"
+#endif
+
+#if HAVE_LIBCRYPTSETUP
+#define _LIBCRYPTSETUP_FEATURE_ "+LIBCRYPTSETUP"
+#else
+#define _LIBCRYPTSETUP_FEATURE_ "-LIBCRYPTSETUP"
+#endif
+
+#if HAVE_GCRYPT
+#define _GCRYPT_FEATURE_ "+GCRYPT"
+#else
+#define _GCRYPT_FEATURE_ "-GCRYPT"
+#endif
+
+#if HAVE_GNUTLS
+#define _GNUTLS_FEATURE_ "+GNUTLS"
+#else
+#define _GNUTLS_FEATURE_ "-GNUTLS"
+#endif
+
+#if HAVE_ACL
+#define _ACL_FEATURE_ "+ACL"
+#else
+#define _ACL_FEATURE_ "-ACL"
+#endif
+
+#if HAVE_XZ
+#define _XZ_FEATURE_ "+XZ"
+#else
+#define _XZ_FEATURE_ "-XZ"
+#endif
+
+#if HAVE_LZ4
+#define _LZ4_FEATURE_ "+LZ4"
+#else
+#define _LZ4_FEATURE_ "-LZ4"
+#endif
+
+#if HAVE_SECCOMP
+#define _SECCOMP_FEATURE_ "+SECCOMP"
+#else
+#define _SECCOMP_FEATURE_ "-SECCOMP"
+#endif
+
+#if HAVE_BLKID
+#define _BLKID_FEATURE_ "+BLKID"
+#else
+#define _BLKID_FEATURE_ "-BLKID"
+#endif
+
+#if HAVE_ELFUTILS
+#define _ELFUTILS_FEATURE_ "+ELFUTILS"
+#else
+#define _ELFUTILS_FEATURE_ "-ELFUTILS"
+#endif
+
+#if HAVE_KMOD
+#define _KMOD_FEATURE_ "+KMOD"
+#else
+#define _KMOD_FEATURE_ "-KMOD"
+#endif
+
+#if HAVE_LIBIDN2
+#define _IDN2_FEATURE_ "+IDN2"
+#else
+#define _IDN2_FEATURE_ "-IDN2"
+#endif
+
+#if HAVE_LIBIDN
+#define _IDN_FEATURE_ "+IDN"
+#else
+#define _IDN_FEATURE_ "-IDN"
+#endif
+
+#if HAVE_PCRE2
+#define _PCRE2_FEATURE_ "+PCRE2"
+#else
+#define _PCRE2_FEATURE_ "-PCRE2"
+#endif
+
+#define _CGROUP_HIEARCHY_ "default-hierarchy=" DEFAULT_HIERARCHY_NAME
+
+#define SYSTEMD_FEATURES                                                \
+        _PAM_FEATURE_ " "                                               \
+        _AUDIT_FEATURE_ " "                                             \
+        _SELINUX_FEATURE_ " "                                           \
+        _IMA_FEATURE_ " "                                               \
+        _APPARMOR_FEATURE_ " "                                          \
+        _SMACK_FEATURE_ " "                                             \
+        _SYSVINIT_FEATURE_ " "                                          \
+        _UTMP_FEATURE_ " "                                              \
+        _LIBCRYPTSETUP_FEATURE_ " "                                     \
+        _GCRYPT_FEATURE_ " "                                            \
+        _GNUTLS_FEATURE_ " "                                            \
+        _ACL_FEATURE_ " "                                               \
+        _XZ_FEATURE_ " "                                                \
+        _LZ4_FEATURE_ " "                                               \
+        _SECCOMP_FEATURE_ " "                                           \
+        _BLKID_FEATURE_ " "                                             \
+        _ELFUTILS_FEATURE_ " "                                          \
+        _KMOD_FEATURE_ " "                                              \
+        _IDN2_FEATURE_ " "                                              \
+        _IDN_FEATURE_ " "                                               \
+        _PCRE2_FEATURE_ " "                                             \
+        _CGROUP_HIEARCHY_
diff --git a/src/basic/bus-label.c b/src/basic/bus-label.c
new file mode 100644
index 0000000..1613cf7
--- /dev/null
+++ b/src/basic/bus-label.c
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "bus-label.h"
+#include "hexdecoct.h"
+#include "macro.h"
+
+char *bus_label_escape(const char *s) {
+        char *r, *t;
+        const char *f;
+
+        assert_return(s, NULL);
+
+        /* Escapes all chars that D-Bus' object path cannot deal
+         * with. Can be reversed with bus_path_unescape(). We special
+         * case the empty string. */
+
+        if (*s == 0)
+                return strdup("_");
+
+        r = new(char, strlen(s)*3 + 1);
+        if (!r)
+                return NULL;
+
+        for (f = s, t = r; *f; f++) {
+
+                /* Escape everything that is not a-zA-Z0-9. We also
+                 * escape 0-9 if it's the first character */
+
+                if (!(*f >= 'A' && *f <= 'Z') &&
+                    !(*f >= 'a' && *f <= 'z') &&
+                    !(f > s && *f >= '0' && *f <= '9')) {
+                        *(t++) = '_';
+                        *(t++) = hexchar(*f >> 4);
+                        *(t++) = hexchar(*f);
+                } else
+                        *(t++) = *f;
+        }
+
+        *t = 0;
+
+        return r;
+}
+
+char *bus_label_unescape_n(const char *f, size_t l) {
+        char *r, *t;
+        size_t i;
+
+        assert_return(f, NULL);
+
+        /* Special case for the empty string */
+        if (l == 1 && *f == '_')
+                return strdup("");
+
+        r = new(char, l + 1);
+        if (!r)
+                return NULL;
+
+        for (i = 0, t = r; i < l; ++i) {
+                if (f[i] == '_') {
+                        int a, b;
+
+                        if (l - i < 3 ||
+                            (a = unhexchar(f[i + 1])) < 0 ||
+                            (b = unhexchar(f[i + 2])) < 0) {
+                                /* Invalid escape code, let's take it literal then */
+                                *(t++) = '_';
+                        } else {
+                                *(t++) = (char) ((a << 4) | b);
+                                i += 2;
+                        }
+                } else
+                        *(t++) = f[i];
+        }
+
+        *t = 0;
+
+        return r;
+}
diff --git a/src/basic/bus-label.h b/src/basic/bus-label.h
new file mode 100644
index 0000000..664cfaf
--- /dev/null
+++ b/src/basic/bus-label.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "string-util.h"
+
+char *bus_label_escape(const char *s);
+char *bus_label_unescape_n(const char *f, size_t l);
+
+static inline char *bus_label_unescape(const char *f) {
+        return bus_label_unescape_n(f, strlen_ptr(f));
+}
diff --git a/src/basic/cap-list.c b/src/basic/cap-list.c
new file mode 100644
index 0000000..29a17d9
--- /dev/null
+++ b/src/basic/cap-list.c
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "capability-util.h"
+#include "cap-list.h"
+#include "extract-word.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "util.h"
+
+static const struct capability_name* lookup_capability(register const char *str, register GPERF_LEN_TYPE len);
+
+#include "cap-from-name.h"
+#include "cap-to-name.h"
+
+const char *capability_to_name(int id) {
+
+        if (id < 0)
+                return NULL;
+
+        if ((size_t) id >= ELEMENTSOF(capability_names))
+                return NULL;
+
+        return capability_names[id];
+}
+
+int capability_from_name(const char *name) {
+        const struct capability_name *sc;
+        int r, i;
+
+        assert(name);
+
+        /* Try to parse numeric capability */
+        r = safe_atoi(name, &i);
+        if (r >= 0) {
+                if (i >= 0 && (size_t) i < ELEMENTSOF(capability_names))
+                        return i;
+                else
+                        return -EINVAL;
+        }
+
+        /* Try to parse string capability */
+        sc = lookup_capability(name, strlen(name));
+        if (!sc)
+                return -EINVAL;
+
+        return sc->id;
+}
+
+int capability_list_length(void) {
+        return (int) ELEMENTSOF(capability_names);
+}
+
+int capability_set_to_string_alloc(uint64_t set, char **s) {
+        _cleanup_free_ char *str = NULL;
+        unsigned long i;
+        size_t allocated = 0, n = 0;
+
+        assert(s);
+
+        for (i = 0; i < cap_last_cap(); i++)
+                if (set & (UINT64_C(1) << i)) {
+                        const char *p;
+                        size_t add;
+
+                        p = capability_to_name(i);
+                        if (!p)
+                                return -EINVAL;
+
+                        add = strlen(p);
+
+                        if (!GREEDY_REALLOC(str, allocated, n + add + 2))
+                                return -ENOMEM;
+
+                        strcpy(mempcpy(str + n, p, add), " ");
+                        n += add + 1;
+                }
+
+        if (!GREEDY_REALLOC(str, allocated, n + 1))
+                return -ENOMEM;
+
+        str[n > 0 ? n - 1 : 0] = '\0'; /* truncate the last space, if it's there */
+
+        *s = TAKE_PTR(str);
+
+        return 0;
+}
+
+int capability_set_from_string(const char *s, uint64_t *set) {
+        uint64_t val = 0;
+        const char *p;
+
+        assert(set);
+
+        for (p = s;;) {
+                _cleanup_free_ char *word = NULL;
+                int r;
+
+                r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES);
+                if (r == -ENOMEM)
+                        return r;
+                if (r <= 0)
+                        break;
+
+                r = capability_from_name(word);
+                if (r < 0)
+                        continue;
+
+                val |= ((uint64_t) UINT64_C(1)) << (uint64_t) r;
+        }
+
+        *set = val;
+
+        return 0;
+}
diff --git a/src/basic/cap-list.h b/src/basic/cap-list.h
new file mode 100644
index 0000000..ab41924
--- /dev/null
+++ b/src/basic/cap-list.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+const char *capability_to_name(int id);
+int capability_from_name(const char *name);
+int capability_list_length(void);
+
+int capability_set_to_string_alloc(uint64_t set, char **s);
+int capability_set_from_string(const char *s, uint64_t *set);
diff --git a/src/basic/cap-to-name.awk b/src/basic/cap-to-name.awk
new file mode 100644
index 0000000..402a782
--- /dev/null
+++ b/src/basic/cap-to-name.awk
@@ -0,0 +1,9 @@
+BEGIN{
+        print "static const char* const capability_names[] = { "
+}
+{
+        printf "        [%s] = \"%s\",\n", $1, tolower($1)
+}
+END{
+        print "};"
+}
diff --git a/src/basic/capability-util.c b/src/basic/capability-util.c
new file mode 100644
index 0000000..b944ee6
--- /dev/null
+++ b/src/basic/capability-util.c
@@ -0,0 +1,487 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <grp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/capability.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "capability-util.h"
+#include "fileio.h"
+#include "log.h"
+#include "macro.h"
+#include "missing_prctl.h"
+#include "parse-util.h"
+#include "user-util.h"
+#include "util.h"
+
+int have_effective_cap(int value) {
+        _cleanup_cap_free_ cap_t cap;
+        cap_flag_value_t fv;
+
+        cap = cap_get_proc();
+        if (!cap)
+                return -errno;
+
+        if (cap_get_flag(cap, value, CAP_EFFECTIVE, &fv) < 0)
+                return -errno;
+        else
+                return fv == CAP_SET;
+}
+
+unsigned long cap_last_cap(void) {
+        static thread_local unsigned long saved;
+        static thread_local bool valid = false;
+        _cleanup_free_ char *content = NULL;
+        unsigned long p = 0;
+        int r;
+
+        if (valid)
+                return saved;
+
+        /* available since linux-3.2 */
+        r = read_one_line_file("/proc/sys/kernel/cap_last_cap", &content);
+        if (r >= 0) {
+                r = safe_atolu(content, &p);
+                if (r >= 0) {
+                        saved = p;
+                        valid = true;
+                        return p;
+                }
+        }
+
+        /* fall back to syscall-probing for pre linux-3.2 */
+        p = (unsigned long) CAP_LAST_CAP;
+
+        if (prctl(PR_CAPBSET_READ, p) < 0) {
+
+                /* Hmm, look downwards, until we find one that
+                 * works */
+                for (p--; p > 0; p --)
+                        if (prctl(PR_CAPBSET_READ, p) >= 0)
+                                break;
+
+        } else {
+
+                /* Hmm, look upwards, until we find one that doesn't
+                 * work */
+                for (;; p++)
+                        if (prctl(PR_CAPBSET_READ, p+1) < 0)
+                                break;
+        }
+
+        saved = p;
+        valid = true;
+
+        return p;
+}
+
+int capability_update_inherited_set(cap_t caps, uint64_t set) {
+        unsigned long i;
+
+        /* Add capabilities in the set to the inherited caps. Do not apply
+         * them yet. */
+
+        for (i = 0; i < cap_last_cap(); i++) {
+
+                if (set & (UINT64_C(1) << i)) {
+                        cap_value_t v;
+
+                        v = (cap_value_t) i;
+
+                        /* Make the capability inheritable. */
+                        if (cap_set_flag(caps, CAP_INHERITABLE, 1, &v, CAP_SET) < 0)
+                                return -errno;
+                }
+        }
+
+        return 0;
+}
+
+int capability_ambient_set_apply(uint64_t set, bool also_inherit) {
+        unsigned long i;
+        _cleanup_cap_free_ cap_t caps = NULL;
+
+        /* Add the capabilities to the ambient set. */
+
+        if (also_inherit) {
+                int r;
+                caps = cap_get_proc();
+                if (!caps)
+                        return -errno;
+
+                r = capability_update_inherited_set(caps, set);
+                if (r < 0)
+                        return -errno;
+
+                if (cap_set_proc(caps) < 0)
+                        return -errno;
+        }
+
+        for (i = 0; i < cap_last_cap(); i++) {
+
+                if (set & (UINT64_C(1) << i)) {
+
+                        /* Add the capability to the ambient set. */
+                        if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, i, 0, 0) < 0)
+                                return -errno;
+                }
+        }
+
+        return 0;
+}
+
+int capability_bounding_set_drop(uint64_t keep, bool right_now) {
+        _cleanup_cap_free_ cap_t before_cap = NULL, after_cap = NULL;
+        cap_flag_value_t fv;
+        unsigned long i;
+        int r;
+
+        /* If we are run as PID 1 we will lack CAP_SETPCAP by default
+         * in the effective set (yes, the kernel drops that when
+         * executing init!), so get it back temporarily so that we can
+         * call PR_CAPBSET_DROP. */
+
+        before_cap = cap_get_proc();
+        if (!before_cap)
+                return -errno;
+
+        if (cap_get_flag(before_cap, CAP_SETPCAP, CAP_EFFECTIVE, &fv) < 0)
+                return -errno;
+
+        if (fv != CAP_SET) {
+                _cleanup_cap_free_ cap_t temp_cap = NULL;
+                static const cap_value_t v = CAP_SETPCAP;
+
+                temp_cap = cap_dup(before_cap);
+                if (!temp_cap)
+                        return -errno;
+
+                if (cap_set_flag(temp_cap, CAP_EFFECTIVE, 1, &v, CAP_SET) < 0)
+                        return -errno;
+
+                if (cap_set_proc(temp_cap) < 0)
+                        log_debug_errno(errno, "Can't acquire effective CAP_SETPCAP bit, ignoring: %m");
+
+                /* If we didn't manage to acquire the CAP_SETPCAP bit, we continue anyway, after all this just means
+                 * we'll fail later, when we actually intend to drop some capabilities. */
+        }
+
+        after_cap = cap_dup(before_cap);
+        if (!after_cap)
+                return -errno;
+
+        for (i = 0; i <= cap_last_cap(); i++) {
+                cap_value_t v;
+
+                if ((keep & (UINT64_C(1) << i)))
+                        continue;
+
+                /* Drop it from the bounding set */
+                if (prctl(PR_CAPBSET_DROP, i) < 0) {
+                        r = -errno;
+
+                        /* If dropping the capability failed, let's see if we didn't have it in the first place. If so,
+                         * continue anyway, as dropping a capability we didn't have in the first place doesn't really
+                         * matter anyway. */
+                        if (prctl(PR_CAPBSET_READ, i) != 0)
+                                goto finish;
+                }
+                v = (cap_value_t) i;
+
+                /* Also drop it from the inheritable set, so
+                 * that anything we exec() loses the
+                 * capability for good. */
+                if (cap_set_flag(after_cap, CAP_INHERITABLE, 1, &v, CAP_CLEAR) < 0) {
+                        r = -errno;
+                        goto finish;
+                }
+
+                /* If we shall apply this right now drop it
+                 * also from our own capability sets. */
+                if (right_now) {
+                        if (cap_set_flag(after_cap, CAP_PERMITTED, 1, &v, CAP_CLEAR) < 0 ||
+                            cap_set_flag(after_cap, CAP_EFFECTIVE, 1, &v, CAP_CLEAR) < 0) {
+                                r = -errno;
+                                goto finish;
+                        }
+                }
+        }
+
+        r = 0;
+
+finish:
+        if (cap_set_proc(after_cap) < 0) {
+                /* If there are no actual changes anyway then let's ignore this error. */
+                if (cap_compare(before_cap, after_cap) != 0)
+                        r = -errno;
+        }
+
+        return r;
+}
+
+static int drop_from_file(const char *fn, uint64_t keep) {
+        _cleanup_free_ char *p = NULL;
+        uint64_t current, after;
+        uint32_t hi, lo;
+        int r, k;
+
+        r = read_one_line_file(fn, &p);
+        if (r < 0)
+                return r;
+
+        assert_cc(sizeof(hi) == sizeof(unsigned));
+        assert_cc(sizeof(lo) == sizeof(unsigned));
+
+        k = sscanf(p, "%u %u", &lo, &hi);
+        if (k != 2)
+                return -EIO;
+
+        current = (uint64_t) lo | ((uint64_t) hi << 32ULL);
+        after = current & keep;
+
+        if (current == after)
+                return 0;
+
+        lo = (unsigned) (after & 0xFFFFFFFFULL);
+        hi = (unsigned) ((after >> 32ULL) & 0xFFFFFFFFULL);
+
+        return write_string_filef(fn, WRITE_STRING_FILE_CREATE, "%u %u", lo, hi);
+}
+
+int capability_bounding_set_drop_usermode(uint64_t keep) {
+        int r;
+
+        r = drop_from_file("/proc/sys/kernel/usermodehelper/inheritable", keep);
+        if (r < 0)
+                return r;
+
+        r = drop_from_file("/proc/sys/kernel/usermodehelper/bset", keep);
+        if (r < 0)
+                return r;
+
+        return r;
+}
+
+int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities) {
+        _cleanup_cap_free_ cap_t d = NULL;
+        unsigned i, j = 0;
+        int r;
+
+        /* Unfortunately we cannot leave privilege dropping to PID 1
+         * here, since we want to run as user but want to keep some
+         * capabilities. Since file capabilities have been introduced
+         * this cannot be done across exec() anymore, unless our
+         * binary has the capability configured in the file system,
+         * which we want to avoid. */
+
+        if (setresgid(gid, gid, gid) < 0)
+                return log_error_errno(errno, "Failed to change group ID: %m");
+
+        r = maybe_setgroups(0, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to drop auxiliary groups list: %m");
+
+        /* Ensure we keep the permitted caps across the setresuid() */
+        if (prctl(PR_SET_KEEPCAPS, 1) < 0)
+                return log_error_errno(errno, "Failed to enable keep capabilities flag: %m");
+
+        if (setresuid(uid, uid, uid) < 0)
+                return log_error_errno(errno, "Failed to change user ID: %m");
+
+        if (prctl(PR_SET_KEEPCAPS, 0) < 0)
+                return log_error_errno(errno, "Failed to disable keep capabilities flag: %m");
+
+        /* Drop all caps from the bounding set, except the ones we want */
+        r = capability_bounding_set_drop(keep_capabilities, true);
+        if (r < 0)
+                return log_error_errno(r, "Failed to drop capabilities: %m");
+
+        /* Now upgrade the permitted caps we still kept to effective caps */
+        d = cap_init();
+        if (!d)
+                return log_oom();
+
+        if (keep_capabilities) {
+                cap_value_t bits[u64log2(keep_capabilities) + 1];
+
+                for (i = 0; i < ELEMENTSOF(bits); i++)
+                        if (keep_capabilities & (1ULL << i))
+                                bits[j++] = i;
+
+                /* use enough bits */
+                assert(i == 64 || (keep_capabilities >> i) == 0);
+                /* don't use too many bits */
+                assert(keep_capabilities & (1ULL << (i - 1)));
+
+                if (cap_set_flag(d, CAP_EFFECTIVE, j, bits, CAP_SET) < 0 ||
+                    cap_set_flag(d, CAP_PERMITTED, j, bits, CAP_SET) < 0)
+                        return log_error_errno(errno, "Failed to enable capabilities bits: %m");
+
+                if (cap_set_proc(d) < 0)
+                        return log_error_errno(errno, "Failed to increase capabilities: %m");
+        }
+
+        return 0;
+}
+
+int drop_capability(cap_value_t cv) {
+        _cleanup_cap_free_ cap_t tmp_cap = NULL;
+
+        tmp_cap = cap_get_proc();
+        if (!tmp_cap)
+                return -errno;
+
+        if ((cap_set_flag(tmp_cap, CAP_INHERITABLE, 1, &cv, CAP_CLEAR) < 0) ||
+            (cap_set_flag(tmp_cap, CAP_PERMITTED, 1, &cv, CAP_CLEAR) < 0) ||
+            (cap_set_flag(tmp_cap, CAP_EFFECTIVE, 1, &cv, CAP_CLEAR) < 0))
+                return -errno;
+
+        if (cap_set_proc(tmp_cap) < 0)
+                return -errno;
+
+        return 0;
+}
+
+bool ambient_capabilities_supported(void) {
+        static int cache = -1;
+
+        if (cache >= 0)
+                return cache;
+
+        /* If PR_CAP_AMBIENT returns something valid, or an unexpected error code we assume that ambient caps are
+         * available. */
+
+        cache = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_KILL, 0, 0) >= 0 ||
+                !IN_SET(errno, EINVAL, EOPNOTSUPP, ENOSYS);
+
+        return cache;
+}
+
+int capability_quintet_enforce(const CapabilityQuintet *q) {
+        _cleanup_cap_free_ cap_t c = NULL;
+        int r;
+
+        if (q->ambient != (uint64_t) -1) {
+                unsigned long i;
+                bool changed = false;
+
+                c = cap_get_proc();
+                if (!c)
+                        return -errno;
+
+                /* In order to raise the ambient caps set we first need to raise the matching inheritable + permitted
+                 * cap */
+                for (i = 0; i <= cap_last_cap(); i++) {
+                        uint64_t m = UINT64_C(1) << i;
+                        cap_value_t cv = (cap_value_t) i;
+                        cap_flag_value_t old_value_inheritable, old_value_permitted;
+
+                        if ((q->ambient & m) == 0)
+                                continue;
+
+                        if (cap_get_flag(c, cv, CAP_INHERITABLE, &old_value_inheritable) < 0)
+                                return -errno;
+                        if (cap_get_flag(c, cv, CAP_PERMITTED, &old_value_permitted) < 0)
+                                return -errno;
+
+                        if (old_value_inheritable == CAP_SET && old_value_permitted == CAP_SET)
+                                continue;
+
+                        if (cap_set_flag(c, CAP_INHERITABLE, 1, &cv, CAP_SET) < 0)
+                                return -errno;
+
+                        if (cap_set_flag(c, CAP_PERMITTED, 1, &cv, CAP_SET) < 0)
+                                return -errno;
+
+                        changed = true;
+                }
+
+                if (changed)
+                        if (cap_set_proc(c) < 0)
+                                return -errno;
+
+                r = capability_ambient_set_apply(q->ambient, false);
+                if (r < 0)
+                        return r;
+        }
+
+        if (q->inheritable != (uint64_t) -1 || q->permitted != (uint64_t) -1 || q->effective != (uint64_t) -1) {
+                bool changed = false;
+                unsigned long i;
+
+                if (!c) {
+                        c = cap_get_proc();
+                        if (!c)
+                                return -errno;
+                }
+
+                for (i = 0; i <= cap_last_cap(); i++) {
+                        uint64_t m = UINT64_C(1) << i;
+                        cap_value_t cv = (cap_value_t) i;
+
+                        if (q->inheritable != (uint64_t) -1) {
+                                cap_flag_value_t old_value, new_value;
+
+                                if (cap_get_flag(c, cv, CAP_INHERITABLE, &old_value) < 0)
+                                        return -errno;
+
+                                new_value = (q->inheritable & m) ? CAP_SET : CAP_CLEAR;
+
+                                if (old_value != new_value) {
+                                        changed = true;
+
+                                        if (cap_set_flag(c, CAP_INHERITABLE, 1, &cv, new_value) < 0)
+                                                return -errno;
+                                }
+                        }
+
+                        if (q->permitted != (uint64_t) -1) {
+                                cap_flag_value_t old_value, new_value;
+
+                                if (cap_get_flag(c, cv, CAP_PERMITTED, &old_value) < 0)
+                                        return -errno;
+
+                                new_value = (q->permitted & m) ? CAP_SET : CAP_CLEAR;
+
+                                if (old_value != new_value) {
+                                        changed = true;
+
+                                        if (cap_set_flag(c, CAP_PERMITTED, 1, &cv, new_value) < 0)
+                                                return -errno;
+                                }
+                        }
+
+                        if (q->effective != (uint64_t) -1) {
+                                cap_flag_value_t old_value, new_value;
+
+                                if (cap_get_flag(c, cv, CAP_EFFECTIVE, &old_value) < 0)
+                                        return -errno;
+
+                                new_value = (q->effective & m) ? CAP_SET : CAP_CLEAR;
+
+                                if (old_value != new_value) {
+                                        changed = true;
+
+                                        if (cap_set_flag(c, CAP_EFFECTIVE, 1, &cv, new_value) < 0)
+                                                return -errno;
+                                }
+                        }
+                }
+
+                if (changed)
+                        if (cap_set_proc(c) < 0)
+                                return -errno;
+        }
+
+        if (q->bounding != (uint64_t) -1) {
+                r = capability_bounding_set_drop(q->bounding, false);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
diff --git a/src/basic/capability-util.h b/src/basic/capability-util.h
new file mode 100644
index 0000000..02c7d5c
--- /dev/null
+++ b/src/basic/capability-util.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/capability.h>
+#include <sys/types.h>
+
+#include "macro.h"
+#include "missing_capability.h"
+#include "util.h"
+
+#define CAP_ALL (uint64_t) -1
+
+unsigned long cap_last_cap(void);
+int have_effective_cap(int value);
+int capability_bounding_set_drop(uint64_t keep, bool right_now);
+int capability_bounding_set_drop_usermode(uint64_t keep);
+
+int capability_ambient_set_apply(uint64_t set, bool also_inherit);
+int capability_update_inherited_set(cap_t caps, uint64_t ambient_set);
+
+int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities);
+
+int drop_capability(cap_value_t cv);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(cap_t, cap_free);
+#define _cleanup_cap_free_ _cleanup_(cap_freep)
+
+static inline void cap_free_charpp(char **p) {
+        if (*p)
+                cap_free(*p);
+}
+#define _cleanup_cap_free_charp_ _cleanup_(cap_free_charpp)
+
+static inline bool cap_test_all(uint64_t caps) {
+        uint64_t m;
+        m = (UINT64_C(1) << (cap_last_cap() + 1)) - 1;
+        return FLAGS_SET(caps, m);
+}
+
+bool ambient_capabilities_supported(void);
+
+/* Identical to linux/capability.h's CAP_TO_MASK(), but uses an unsigned 1U instead of a signed 1 for shifting left, in
+ * order to avoid complaints about shifting a signed int left by 31 bits, which would make it negative. */
+#define CAP_TO_MASK_CORRECTED(x) (1U << ((x) & 31U))
+
+typedef struct CapabilityQuintet {
+        /* Stores all five types of capabilities in one go. Note that we use (uint64_t) -1 for unset here. This hence
+         * needs to be updated as soon as Linux learns more than 63 caps. */
+        uint64_t effective;
+        uint64_t bounding;
+        uint64_t inheritable;
+        uint64_t permitted;
+        uint64_t ambient;
+} CapabilityQuintet;
+
+assert_cc(CAP_LAST_CAP < 64);
+
+#define CAPABILITY_QUINTET_NULL { (uint64_t) -1, (uint64_t) -1, (uint64_t) -1, (uint64_t) -1, (uint64_t) -1 }
+
+static inline bool capability_quintet_is_set(const CapabilityQuintet *q) {
+        return q->effective != (uint64_t) -1 ||
+                q->bounding != (uint64_t) -1 ||
+                q->inheritable != (uint64_t) -1 ||
+                q->permitted != (uint64_t) -1 ||
+                q->ambient != (uint64_t) -1;
+}
+
+int capability_quintet_enforce(const CapabilityQuintet *q);
diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
new file mode 100644
index 0000000..8ce7ccb
--- /dev/null
+++ b/src/basic/cgroup-util.c
@@ -0,0 +1,2933 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <ftw.h>
+#include <limits.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <sys/xattr.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "cgroup-util.h"
+#include "def.h"
+#include "dirent-util.h"
+#include "extract-word.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "fs-util.h"
+#include "log.h"
+#include "login-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "mkdir.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "proc-cmdline.h"
+#include "process-util.h"
+#include "set.h"
+#include "special.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "user-util.h"
+
+int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
+        _cleanup_free_ char *fs = NULL;
+        FILE *f;
+        int r;
+
+        assert(_f);
+
+        r = cg_get_path(controller, path, "cgroup.procs", &fs);
+        if (r < 0)
+                return r;
+
+        f = fopen(fs, "re");
+        if (!f)
+                return -errno;
+
+        *_f = f;
+        return 0;
+}
+
+int cg_read_pid(FILE *f, pid_t *_pid) {
+        unsigned long ul;
+
+        /* Note that the cgroup.procs might contain duplicates! See
+         * cgroups.txt for details. */
+
+        assert(f);
+        assert(_pid);
+
+        errno = 0;
+        if (fscanf(f, "%lu", &ul) != 1) {
+
+                if (feof(f))
+                        return 0;
+
+                return errno > 0 ? -errno : -EIO;
+        }
+
+        if (ul <= 0)
+                return -EIO;
+
+        *_pid = (pid_t) ul;
+        return 1;
+}
+
+int cg_read_event(
+                const char *controller,
+                const char *path,
+                const char *event,
+                char **val) {
+
+        _cleanup_free_ char *events = NULL, *content = NULL;
+        char *p, *line;
+        int r;
+
+        r = cg_get_path(controller, path, "cgroup.events", &events);
+        if (r < 0)
+                return r;
+
+        r = read_full_file(events, &content, NULL);
+        if (r < 0)
+                return r;
+
+        p = content;
+        while ((line = strsep(&p, "\n"))) {
+                char *key;
+
+                key = strsep(&line, " ");
+                if (!key || !line)
+                        return -EINVAL;
+
+                if (strcmp(key, event))
+                        continue;
+
+                *val = strdup(line);
+                return 0;
+        }
+
+        return -ENOENT;
+}
+
+bool cg_ns_supported(void) {
+        static thread_local int enabled = -1;
+
+        if (enabled >= 0)
+                return enabled;
+
+        if (access("/proc/self/ns/cgroup", F_OK) < 0) {
+                if (errno != ENOENT)
+                        log_debug_errno(errno, "Failed to check whether /proc/self/ns/cgroup is available, assuming not: %m");
+                enabled = false;
+        } else
+                enabled = true;
+
+        return enabled;
+}
+
+int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
+        _cleanup_free_ char *fs = NULL;
+        int r;
+        DIR *d;
+
+        assert(_d);
+
+        /* This is not recursive! */
+
+        r = cg_get_path(controller, path, NULL, &fs);
+        if (r < 0)
+                return r;
+
+        d = opendir(fs);
+        if (!d)
+                return -errno;
+
+        *_d = d;
+        return 0;
+}
+
+int cg_read_subgroup(DIR *d, char **fn) {
+        struct dirent *de;
+
+        assert(d);
+        assert(fn);
+
+        FOREACH_DIRENT_ALL(de, d, return -errno) {
+                char *b;
+
+                if (de->d_type != DT_DIR)
+                        continue;
+
+                if (dot_or_dot_dot(de->d_name))
+                        continue;
+
+                b = strdup(de->d_name);
+                if (!b)
+                        return -ENOMEM;
+
+                *fn = b;
+                return 1;
+        }
+
+        return 0;
+}
+
+int cg_rmdir(const char *controller, const char *path) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        r = cg_get_path(controller, path, NULL, &p);
+        if (r < 0)
+                return r;
+
+        r = rmdir(p);
+        if (r < 0 && errno != ENOENT)
+                return -errno;
+
+        r = cg_hybrid_unified();
+        if (r <= 0)
+                return r;
+
+        if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                r = cg_rmdir(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to remove compat systemd cgroup %s: %m", path);
+        }
+
+        return 0;
+}
+
+int cg_kill(
+                const char *controller,
+                const char *path,
+                int sig,
+                CGroupFlags flags,
+                Set *s,
+                cg_kill_log_func_t log_kill,
+                void *userdata) {
+
+        _cleanup_set_free_ Set *allocated_set = NULL;
+        bool done = false;
+        int r, ret = 0;
+        pid_t my_pid;
+
+        assert(sig >= 0);
+
+         /* Don't send SIGCONT twice. Also, SIGKILL always works even when process is suspended, hence don't send
+          * SIGCONT on SIGKILL. */
+        if (IN_SET(sig, SIGCONT, SIGKILL))
+                flags &= ~CGROUP_SIGCONT;
+
+        /* This goes through the tasks list and kills them all. This
+         * is repeated until no further processes are added to the
+         * tasks list, to properly handle forking processes */
+
+        if (!s) {
+                s = allocated_set = set_new(NULL);
+                if (!s)
+                        return -ENOMEM;
+        }
+
+        my_pid = getpid_cached();
+
+        do {
+                _cleanup_fclose_ FILE *f = NULL;
+                pid_t pid = 0;
+                done = true;
+
+                r = cg_enumerate_processes(controller, path, &f);
+                if (r < 0) {
+                        if (ret >= 0 && r != -ENOENT)
+                                return r;
+
+                        return ret;
+                }
+
+                while ((r = cg_read_pid(f, &pid)) > 0) {
+
+                        if ((flags & CGROUP_IGNORE_SELF) && pid == my_pid)
+                                continue;
+
+                        if (set_get(s, PID_TO_PTR(pid)) == PID_TO_PTR(pid))
+                                continue;
+
+                        if (log_kill)
+                                log_kill(pid, sig, userdata);
+
+                        /* If we haven't killed this process yet, kill
+                         * it */
+                        if (kill(pid, sig) < 0) {
+                                if (ret >= 0 && errno != ESRCH)
+                                        ret = -errno;
+                        } else {
+                                if (flags & CGROUP_SIGCONT)
+                                        (void) kill(pid, SIGCONT);
+
+                                if (ret == 0)
+                                        ret = 1;
+                        }
+
+                        done = false;
+
+                        r = set_put(s, PID_TO_PTR(pid));
+                        if (r < 0) {
+                                if (ret >= 0)
+                                        return r;
+
+                                return ret;
+                        }
+                }
+
+                if (r < 0) {
+                        if (ret >= 0)
+                                return r;
+
+                        return ret;
+                }
+
+                /* To avoid racing against processes which fork
+                 * quicker than we can kill them we repeat this until
+                 * no new pids need to be killed. */
+
+        } while (!done);
+
+        return ret;
+}
+
+int cg_kill_recursive(
+                const char *controller,
+                const char *path,
+                int sig,
+                CGroupFlags flags,
+                Set *s,
+                cg_kill_log_func_t log_kill,
+                void *userdata) {
+
+        _cleanup_set_free_ Set *allocated_set = NULL;
+        _cleanup_closedir_ DIR *d = NULL;
+        int r, ret;
+        char *fn;
+
+        assert(path);
+        assert(sig >= 0);
+
+        if (!s) {
+                s = allocated_set = set_new(NULL);
+                if (!s)
+                        return -ENOMEM;
+        }
+
+        ret = cg_kill(controller, path, sig, flags, s, log_kill, userdata);
+
+        r = cg_enumerate_subgroups(controller, path, &d);
+        if (r < 0) {
+                if (ret >= 0 && r != -ENOENT)
+                        return r;
+
+                return ret;
+        }
+
+        while ((r = cg_read_subgroup(d, &fn)) > 0) {
+                _cleanup_free_ char *p = NULL;
+
+                p = strjoin(path, "/", fn);
+                free(fn);
+                if (!p)
+                        return -ENOMEM;
+
+                r = cg_kill_recursive(controller, p, sig, flags, s, log_kill, userdata);
+                if (r != 0 && ret >= 0)
+                        ret = r;
+        }
+        if (ret >= 0 && r < 0)
+                ret = r;
+
+        if (flags & CGROUP_REMOVE) {
+                r = cg_rmdir(controller, path);
+                if (r < 0 && ret >= 0 && !IN_SET(r, -ENOENT, -EBUSY))
+                        return r;
+        }
+
+        return ret;
+}
+
+int cg_migrate(
+                const char *cfrom,
+                const char *pfrom,
+                const char *cto,
+                const char *pto,
+                CGroupFlags flags) {
+
+        bool done = false;
+        _cleanup_set_free_ Set *s = NULL;
+        int r, ret = 0;
+        pid_t my_pid;
+
+        assert(cfrom);
+        assert(pfrom);
+        assert(cto);
+        assert(pto);
+
+        s = set_new(NULL);
+        if (!s)
+                return -ENOMEM;
+
+        my_pid = getpid_cached();
+
+        do {
+                _cleanup_fclose_ FILE *f = NULL;
+                pid_t pid = 0;
+                done = true;
+
+                r = cg_enumerate_processes(cfrom, pfrom, &f);
+                if (r < 0) {
+                        if (ret >= 0 && r != -ENOENT)
+                                return r;
+
+                        return ret;
+                }
+
+                while ((r = cg_read_pid(f, &pid)) > 0) {
+
+                        /* This might do weird stuff if we aren't a
+                         * single-threaded program. However, we
+                         * luckily know we are not */
+                        if ((flags & CGROUP_IGNORE_SELF) && pid == my_pid)
+                                continue;
+
+                        if (set_get(s, PID_TO_PTR(pid)) == PID_TO_PTR(pid))
+                                continue;
+
+                        /* Ignore kernel threads. Since they can only
+                         * exist in the root cgroup, we only check for
+                         * them there. */
+                        if (cfrom &&
+                            empty_or_root(pfrom) &&
+                            is_kernel_thread(pid) > 0)
+                                continue;
+
+                        r = cg_attach(cto, pto, pid);
+                        if (r < 0) {
+                                if (ret >= 0 && r != -ESRCH)
+                                        ret = r;
+                        } else if (ret == 0)
+                                ret = 1;
+
+                        done = false;
+
+                        r = set_put(s, PID_TO_PTR(pid));
+                        if (r < 0) {
+                                if (ret >= 0)
+                                        return r;
+
+                                return ret;
+                        }
+                }
+
+                if (r < 0) {
+                        if (ret >= 0)
+                                return r;
+
+                        return ret;
+                }
+        } while (!done);
+
+        return ret;
+}
+
+int cg_migrate_recursive(
+                const char *cfrom,
+                const char *pfrom,
+                const char *cto,
+                const char *pto,
+                CGroupFlags flags) {
+
+        _cleanup_closedir_ DIR *d = NULL;
+        int r, ret = 0;
+        char *fn;
+
+        assert(cfrom);
+        assert(pfrom);
+        assert(cto);
+        assert(pto);
+
+        ret = cg_migrate(cfrom, pfrom, cto, pto, flags);
+
+        r = cg_enumerate_subgroups(cfrom, pfrom, &d);
+        if (r < 0) {
+                if (ret >= 0 && r != -ENOENT)
+                        return r;
+
+                return ret;
+        }
+
+        while ((r = cg_read_subgroup(d, &fn)) > 0) {
+                _cleanup_free_ char *p = NULL;
+
+                p = strjoin(pfrom, "/", fn);
+                free(fn);
+                if (!p)
+                        return -ENOMEM;
+
+                r = cg_migrate_recursive(cfrom, p, cto, pto, flags);
+                if (r != 0 && ret >= 0)
+                        ret = r;
+        }
+
+        if (r < 0 && ret >= 0)
+                ret = r;
+
+        if (flags & CGROUP_REMOVE) {
+                r = cg_rmdir(cfrom, pfrom);
+                if (r < 0 && ret >= 0 && !IN_SET(r, -ENOENT, -EBUSY))
+                        return r;
+        }
+
+        return ret;
+}
+
+int cg_migrate_recursive_fallback(
+                const char *cfrom,
+                const char *pfrom,
+                const char *cto,
+                const char *pto,
+                CGroupFlags flags) {
+
+        int r;
+
+        assert(cfrom);
+        assert(pfrom);
+        assert(cto);
+        assert(pto);
+
+        r = cg_migrate_recursive(cfrom, pfrom, cto, pto, flags);
+        if (r < 0) {
+                char prefix[strlen(pto) + 1];
+
+                /* This didn't work? Then let's try all prefixes of the destination */
+
+                PATH_FOREACH_PREFIX(prefix, pto) {
+                        int q;
+
+                        q = cg_migrate_recursive(cfrom, pfrom, cto, prefix, flags);
+                        if (q >= 0)
+                                return q;
+                }
+        }
+
+        return r;
+}
+
+static const char *controller_to_dirname(const char *controller) {
+        const char *e;
+
+        assert(controller);
+
+        /* Converts a controller name to the directory name below
+         * /sys/fs/cgroup/ we want to mount it to. Effectively, this
+         * just cuts off the name= prefixed used for named
+         * hierarchies, if it is specified. */
+
+        if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                if (cg_hybrid_unified() > 0)
+                        controller = SYSTEMD_CGROUP_CONTROLLER_HYBRID;
+                else
+                        controller = SYSTEMD_CGROUP_CONTROLLER_LEGACY;
+        }
+
+        e = startswith(controller, "name=");
+        if (e)
+                return e;
+
+        return controller;
+}
+
+static int join_path_legacy(const char *controller, const char *path, const char *suffix, char **fs) {
+        const char *dn;
+        char *t = NULL;
+
+        assert(fs);
+        assert(controller);
+
+        dn = controller_to_dirname(controller);
+
+        if (isempty(path) && isempty(suffix))
+                t = strappend("/sys/fs/cgroup/", dn);
+        else if (isempty(path))
+                t = strjoin("/sys/fs/cgroup/", dn, "/", suffix);
+        else if (isempty(suffix))
+                t = strjoin("/sys/fs/cgroup/", dn, "/", path);
+        else
+                t = strjoin("/sys/fs/cgroup/", dn, "/", path, "/", suffix);
+        if (!t)
+                return -ENOMEM;
+
+        *fs = t;
+        return 0;
+}
+
+static int join_path_unified(const char *path, const char *suffix, char **fs) {
+        char *t;
+
+        assert(fs);
+
+        if (isempty(path) && isempty(suffix))
+                t = strdup("/sys/fs/cgroup");
+        else if (isempty(path))
+                t = strappend("/sys/fs/cgroup/", suffix);
+        else if (isempty(suffix))
+                t = strappend("/sys/fs/cgroup/", path);
+        else
+                t = strjoin("/sys/fs/cgroup/", path, "/", suffix);
+        if (!t)
+                return -ENOMEM;
+
+        *fs = t;
+        return 0;
+}
+
+int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
+        int r;
+
+        assert(fs);
+
+        if (!controller) {
+                char *t;
+
+                /* If no controller is specified, we return the path
+                 * *below* the controllers, without any prefix. */
+
+                if (!path && !suffix)
+                        return -EINVAL;
+
+                if (!suffix)
+                        t = strdup(path);
+                else if (!path)
+                        t = strdup(suffix);
+                else
+                        t = strjoin(path, "/", suffix);
+                if (!t)
+                        return -ENOMEM;
+
+                *fs = path_simplify(t, false);
+                return 0;
+        }
+
+        if (!cg_controller_is_valid(controller))
+                return -EINVAL;
+
+        r = cg_all_unified();
+        if (r < 0)
+                return r;
+        if (r > 0)
+                r = join_path_unified(path, suffix, fs);
+        else
+                r = join_path_legacy(controller, path, suffix, fs);
+        if (r < 0)
+                return r;
+
+        path_simplify(*fs, false);
+        return 0;
+}
+
+static int controller_is_accessible(const char *controller) {
+        int r;
+
+        assert(controller);
+
+        /* Checks whether a specific controller is accessible,
+         * i.e. its hierarchy mounted. In the unified hierarchy all
+         * controllers are considered accessible, except for the named
+         * hierarchies */
+
+        if (!cg_controller_is_valid(controller))
+                return -EINVAL;
+
+        r = cg_all_unified();
+        if (r < 0)
+                return r;
+        if (r > 0) {
+                /* We don't support named hierarchies if we are using
+                 * the unified hierarchy. */
+
+                if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
+                        return 0;
+
+                if (startswith(controller, "name="))
+                        return -EOPNOTSUPP;
+
+        } else {
+                const char *cc, *dn;
+
+                dn = controller_to_dirname(controller);
+                cc = strjoina("/sys/fs/cgroup/", dn);
+
+                if (laccess(cc, F_OK) < 0)
+                        return -errno;
+        }
+
+        return 0;
+}
+
+int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs) {
+        int r;
+
+        assert(controller);
+        assert(fs);
+
+        /* Check if the specified controller is actually accessible */
+        r = controller_is_accessible(controller);
+        if (r < 0)
+                return r;
+
+        return cg_get_path(controller, path, suffix, fs);
+}
+
+static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
+        assert(path);
+        assert(sb);
+        assert(ftwbuf);
+
+        if (typeflag != FTW_DP)
+                return 0;
+
+        if (ftwbuf->level < 1)
+                return 0;
+
+        (void) rmdir(path);
+        return 0;
+}
+
+int cg_trim(const char *controller, const char *path, bool delete_root) {
+        _cleanup_free_ char *fs = NULL;
+        int r = 0, q;
+
+        assert(path);
+
+        r = cg_get_path(controller, path, NULL, &fs);
+        if (r < 0)
+                return r;
+
+        errno = 0;
+        if (nftw(fs, trim_cb, 64, FTW_DEPTH|FTW_MOUNT|FTW_PHYS) != 0) {
+                if (errno == ENOENT)
+                        r = 0;
+                else if (errno > 0)
+                        r = -errno;
+                else
+                        r = -EIO;
+        }
+
+        if (delete_root) {
+                if (rmdir(fs) < 0 && errno != ENOENT)
+                        return -errno;
+        }
+
+        q = cg_hybrid_unified();
+        if (q < 0)
+                return q;
+        if (q > 0 && streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                q = cg_trim(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path, delete_root);
+                if (q < 0)
+                        log_warning_errno(q, "Failed to trim compat systemd cgroup %s: %m", path);
+        }
+
+        return r;
+}
+
+/* Create a cgroup in the hierarchy of controller.
+ * Returns 0 if the group already existed, 1 on success, negative otherwise.
+ */
+int cg_create(const char *controller, const char *path) {
+        _cleanup_free_ char *fs = NULL;
+        int r;
+
+        r = cg_get_path_and_check(controller, path, NULL, &fs);
+        if (r < 0)
+                return r;
+
+        r = mkdir_parents(fs, 0755);
+        if (r < 0)
+                return r;
+
+        r = mkdir_errno_wrapper(fs, 0755);
+        if (r == -EEXIST)
+                return 0;
+        if (r < 0)
+                return r;
+
+        r = cg_hybrid_unified();
+        if (r < 0)
+                return r;
+
+        if (r > 0 && streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                r = cg_create(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to create compat systemd cgroup %s: %m", path);
+        }
+
+        return 1;
+}
+
+int cg_create_and_attach(const char *controller, const char *path, pid_t pid) {
+        int r, q;
+
+        assert(pid >= 0);
+
+        r = cg_create(controller, path);
+        if (r < 0)
+                return r;
+
+        q = cg_attach(controller, path, pid);
+        if (q < 0)
+                return q;
+
+        /* This does not remove the cgroup on failure */
+        return r;
+}
+
+int cg_attach(const char *controller, const char *path, pid_t pid) {
+        _cleanup_free_ char *fs = NULL;
+        char c[DECIMAL_STR_MAX(pid_t) + 2];
+        int r;
+
+        assert(path);
+        assert(pid >= 0);
+
+        r = cg_get_path_and_check(controller, path, "cgroup.procs", &fs);
+        if (r < 0)
+                return r;
+
+        if (pid == 0)
+                pid = getpid_cached();
+
+        xsprintf(c, PID_FMT "\n", pid);
+
+        r = write_string_file(fs, c, WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0)
+                return r;
+
+        r = cg_hybrid_unified();
+        if (r < 0)
+                return r;
+
+        if (r > 0 && streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                r = cg_attach(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path, pid);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to attach "PID_FMT" to compat systemd cgroup %s: %m", pid, path);
+        }
+
+        return 0;
+}
+
+int cg_attach_fallback(const char *controller, const char *path, pid_t pid) {
+        int r;
+
+        assert(controller);
+        assert(path);
+        assert(pid >= 0);
+
+        r = cg_attach(controller, path, pid);
+        if (r < 0) {
+                char prefix[strlen(path) + 1];
+
+                /* This didn't work? Then let's try all prefixes of
+                 * the destination */
+
+                PATH_FOREACH_PREFIX(prefix, path) {
+                        int q;
+
+                        q = cg_attach(controller, prefix, pid);
+                        if (q >= 0)
+                                return q;
+                }
+        }
+
+        return r;
+}
+
+int cg_set_access(
+                const char *controller,
+                const char *path,
+                uid_t uid,
+                gid_t gid) {
+
+        struct Attribute {
+                const char *name;
+                bool fatal;
+        };
+
+        /* cgroup v1, aka legacy/non-unified */
+        static const struct Attribute legacy_attributes[] = {
+                { "cgroup.procs",           true  },
+                { "tasks",                  false },
+                { "cgroup.clone_children",  false },
+                {},
+        };
+
+        /* cgroup v2, aka unified */
+        static const struct Attribute unified_attributes[] = {
+                { "cgroup.procs",           true  },
+                { "cgroup.subtree_control", true  },
+                { "cgroup.threads",         false },
+                {},
+        };
+
+        static const struct Attribute* const attributes[] = {
+                [false] = legacy_attributes,
+                [true]  = unified_attributes,
+        };
+
+        _cleanup_free_ char *fs = NULL;
+        const struct Attribute *i;
+        int r, unified;
+
+        assert(path);
+
+        if (uid == UID_INVALID && gid == GID_INVALID)
+                return 0;
+
+        unified = cg_unified_controller(controller);
+        if (unified < 0)
+                return unified;
+
+        /* Configure access to the cgroup itself */
+        r = cg_get_path(controller, path, NULL, &fs);
+        if (r < 0)
+                return r;
+
+        r = chmod_and_chown(fs, 0755, uid, gid);
+        if (r < 0)
+                return r;
+
+        /* Configure access to the cgroup's attributes */
+        for (i = attributes[unified]; i->name; i++) {
+                fs = mfree(fs);
+
+                r = cg_get_path(controller, path, i->name, &fs);
+                if (r < 0)
+                        return r;
+
+                r = chmod_and_chown(fs, 0644, uid, gid);
+                if (r < 0) {
+                        if (i->fatal)
+                                return r;
+
+                        log_debug_errno(r, "Failed to set access on cgroup %s, ignoring: %m", fs);
+                }
+        }
+
+        if (streq(controller, SYSTEMD_CGROUP_CONTROLLER)) {
+                r = cg_hybrid_unified();
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        /* Always propagate access mode from unified to legacy controller */
+                        r = cg_set_access(SYSTEMD_CGROUP_CONTROLLER_LEGACY, path, uid, gid);
+                        if (r < 0)
+                                log_debug_errno(r, "Failed to set access on compatibility systemd cgroup %s, ignoring: %m", path);
+                }
+        }
+
+        return 0;
+}
+
+int cg_set_xattr(const char *controller, const char *path, const char *name, const void *value, size_t size, int flags) {
+        _cleanup_free_ char *fs = NULL;
+        int r;
+
+        assert(path);
+        assert(name);
+        assert(value || size <= 0);
+
+        r = cg_get_path(controller, path, NULL, &fs);
+        if (r < 0)
+                return r;
+
+        if (setxattr(fs, name, value, size, flags) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int cg_get_xattr(const char *controller, const char *path, const char *name, void *value, size_t size) {
+        _cleanup_free_ char *fs = NULL;
+        ssize_t n;
+        int r;
+
+        assert(path);
+        assert(name);
+
+        r = cg_get_path(controller, path, NULL, &fs);
+        if (r < 0)
+                return r;
+
+        n = getxattr(fs, name, value, size);
+        if (n < 0)
+                return -errno;
+
+        return (int) n;
+}
+
+int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
+        _cleanup_fclose_ FILE *f = NULL;
+        const char *fs, *controller_str;
+        int unified, r;
+        size_t cs = 0;
+
+        assert(path);
+        assert(pid >= 0);
+
+        if (controller) {
+                if (!cg_controller_is_valid(controller))
+                        return -EINVAL;
+        } else
+                controller = SYSTEMD_CGROUP_CONTROLLER;
+
+        unified = cg_unified_controller(controller);
+        if (unified < 0)
+                return unified;
+        if (unified == 0) {
+                if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
+                        controller_str = SYSTEMD_CGROUP_CONTROLLER_LEGACY;
+                else
+                        controller_str = controller;
+
+                cs = strlen(controller_str);
+        }
+
+        fs = procfs_file_alloca(pid, "cgroup");
+        f = fopen(fs, "re");
+        if (!f)
+                return errno == ENOENT ? -ESRCH : -errno;
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                char *e, *p;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (unified) {
+                        e = startswith(line, "0:");
+                        if (!e)
+                                continue;
+
+                        e = strchr(e, ':');
+                        if (!e)
+                                continue;
+                } else {
+                        char *l;
+                        size_t k;
+                        const char *word, *state;
+                        bool found = false;
+
+                        l = strchr(line, ':');
+                        if (!l)
+                                continue;
+
+                        l++;
+                        e = strchr(l, ':');
+                        if (!e)
+                                continue;
+
+                        *e = 0;
+                        FOREACH_WORD_SEPARATOR(word, k, l, ",", state)
+                                if (k == cs && memcmp(word, controller_str, cs) == 0) {
+                                        found = true;
+                                        break;
+                                }
+                        if (!found)
+                                continue;
+                }
+
+                p = strdup(e + 1);
+                if (!p)
+                        return -ENOMEM;
+
+                /* Truncate suffix indicating the process is a zombie */
+                e = endswith(p, " (deleted)");
+                if (e)
+                        *e = 0;
+
+                *path = p;
+                return 0;
+        }
+
+        return -ENODATA;
+}
+
+int cg_install_release_agent(const char *controller, const char *agent) {
+        _cleanup_free_ char *fs = NULL, *contents = NULL;
+        const char *sc;
+        int r;
+
+        assert(agent);
+
+        r = cg_unified_controller(controller);
+        if (r < 0)
+                return r;
+        if (r > 0) /* doesn't apply to unified hierarchy */
+                return -EOPNOTSUPP;
+
+        r = cg_get_path(controller, NULL, "release_agent", &fs);
+        if (r < 0)
+                return r;
+
+        r = read_one_line_file(fs, &contents);
+        if (r < 0)
+                return r;
+
+        sc = strstrip(contents);
+        if (isempty(sc)) {
+                r = write_string_file(fs, agent, WRITE_STRING_FILE_DISABLE_BUFFER);
+                if (r < 0)
+                        return r;
+        } else if (!path_equal(sc, agent))
+                return -EEXIST;
+
+        fs = mfree(fs);
+        r = cg_get_path(controller, NULL, "notify_on_release", &fs);
+        if (r < 0)
+                return r;
+
+        contents = mfree(contents);
+        r = read_one_line_file(fs, &contents);
+        if (r < 0)
+                return r;
+
+        sc = strstrip(contents);
+        if (streq(sc, "0")) {
+                r = write_string_file(fs, "1", WRITE_STRING_FILE_DISABLE_BUFFER);
+                if (r < 0)
+                        return r;
+
+                return 1;
+        }
+
+        if (!streq(sc, "1"))
+                return -EIO;
+
+        return 0;
+}
+
+int cg_uninstall_release_agent(const char *controller) {
+        _cleanup_free_ char *fs = NULL;
+        int r;
+
+        r = cg_unified_controller(controller);
+        if (r < 0)
+                return r;
+        if (r > 0) /* Doesn't apply to unified hierarchy */
+                return -EOPNOTSUPP;
+
+        r = cg_get_path(controller, NULL, "notify_on_release", &fs);
+        if (r < 0)
+                return r;
+
+        r = write_string_file(fs, "0", WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0)
+                return r;
+
+        fs = mfree(fs);
+
+        r = cg_get_path(controller, NULL, "release_agent", &fs);
+        if (r < 0)
+                return r;
+
+        r = write_string_file(fs, "", WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int cg_is_empty(const char *controller, const char *path) {
+        _cleanup_fclose_ FILE *f = NULL;
+        pid_t pid;
+        int r;
+
+        assert(path);
+
+        r = cg_enumerate_processes(controller, path, &f);
+        if (r == -ENOENT)
+                return true;
+        if (r < 0)
+                return r;
+
+        r = cg_read_pid(f, &pid);
+        if (r < 0)
+                return r;
+
+        return r == 0;
+}
+
+int cg_is_empty_recursive(const char *controller, const char *path) {
+        int r;
+
+        assert(path);
+
+        /* The root cgroup is always populated */
+        if (controller && empty_or_root(path))
+                return false;
+
+        r = cg_unified_controller(controller);
+        if (r < 0)
+                return r;
+        if (r > 0) {
+                _cleanup_free_ char *t = NULL;
+
+                /* On the unified hierarchy we can check empty state
+                 * via the "populated" attribute of "cgroup.events". */
+
+                r = cg_read_event(controller, path, "populated", &t);
+                if (r == -ENOENT)
+                        return true;
+                if (r < 0)
+                        return r;
+
+                return streq(t, "0");
+        } else {
+                _cleanup_closedir_ DIR *d = NULL;
+                char *fn;
+
+                r = cg_is_empty(controller, path);
+                if (r <= 0)
+                        return r;
+
+                r = cg_enumerate_subgroups(controller, path, &d);
+                if (r == -ENOENT)
+                        return true;
+                if (r < 0)
+                        return r;
+
+                while ((r = cg_read_subgroup(d, &fn)) > 0) {
+                        _cleanup_free_ char *p = NULL;
+
+                        p = strjoin(path, "/", fn);
+                        free(fn);
+                        if (!p)
+                                return -ENOMEM;
+
+                        r = cg_is_empty_recursive(controller, p);
+                        if (r <= 0)
+                                return r;
+                }
+                if (r < 0)
+                        return r;
+
+                return true;
+        }
+}
+
+int cg_split_spec(const char *spec, char **controller, char **path) {
+        char *t = NULL, *u = NULL;
+        const char *e;
+
+        assert(spec);
+
+        if (*spec == '/') {
+                if (!path_is_normalized(spec))
+                        return -EINVAL;
+
+                if (path) {
+                        t = strdup(spec);
+                        if (!t)
+                                return -ENOMEM;
+
+                        *path = path_simplify(t, false);
+                }
+
+                if (controller)
+                        *controller = NULL;
+
+                return 0;
+        }
+
+        e = strchr(spec, ':');
+        if (!e) {
+                if (!cg_controller_is_valid(spec))
+                        return -EINVAL;
+
+                if (controller) {
+                        t = strdup(spec);
+                        if (!t)
+                                return -ENOMEM;
+
+                        *controller = t;
+                }
+
+                if (path)
+                        *path = NULL;
+
+                return 0;
+        }
+
+        t = strndup(spec, e-spec);
+        if (!t)
+                return -ENOMEM;
+        if (!cg_controller_is_valid(t)) {
+                free(t);
+                return -EINVAL;
+        }
+
+        if (isempty(e+1))
+                u = NULL;
+        else {
+                u = strdup(e+1);
+                if (!u) {
+                        free(t);
+                        return -ENOMEM;
+                }
+
+                if (!path_is_normalized(u) ||
+                    !path_is_absolute(u)) {
+                        free(t);
+                        free(u);
+                        return -EINVAL;
+                }
+
+                path_simplify(u, false);
+        }
+
+        if (controller)
+                *controller = t;
+        else
+                free(t);
+
+        if (path)
+                *path = u;
+        else
+                free(u);
+
+        return 0;
+}
+
+int cg_mangle_path(const char *path, char **result) {
+        _cleanup_free_ char *c = NULL, *p = NULL;
+        char *t;
+        int r;
+
+        assert(path);
+        assert(result);
+
+        /* First, check if it already is a filesystem path */
+        if (path_startswith(path, "/sys/fs/cgroup")) {
+
+                t = strdup(path);
+                if (!t)
+                        return -ENOMEM;
+
+                *result = path_simplify(t, false);
+                return 0;
+        }
+
+        /* Otherwise, treat it as cg spec */
+        r = cg_split_spec(path, &c, &p);
+        if (r < 0)
+                return r;
+
+        return cg_get_path(c ?: SYSTEMD_CGROUP_CONTROLLER, p ?: "/", NULL, result);
+}
+
+int cg_get_root_path(char **path) {
+        char *p, *e;
+        int r;
+
+        assert(path);
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &p);
+        if (r < 0)
+                return r;
+
+        e = endswith(p, "/" SPECIAL_INIT_SCOPE);
+        if (!e)
+                e = endswith(p, "/" SPECIAL_SYSTEM_SLICE); /* legacy */
+        if (!e)
+                e = endswith(p, "/system"); /* even more legacy */
+        if (e)
+                *e = 0;
+
+        *path = p;
+        return 0;
+}
+
+int cg_shift_path(const char *cgroup, const char *root, const char **shifted) {
+        _cleanup_free_ char *rt = NULL;
+        char *p;
+        int r;
+
+        assert(cgroup);
+        assert(shifted);
+
+        if (!root) {
+                /* If the root was specified let's use that, otherwise
+                 * let's determine it from PID 1 */
+
+                r = cg_get_root_path(&rt);
+                if (r < 0)
+                        return r;
+
+                root = rt;
+        }
+
+        p = path_startswith(cgroup, root);
+        if (p && p > cgroup)
+                *shifted = p - 1;
+        else
+                *shifted = cgroup;
+
+        return 0;
+}
+
+int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
+        _cleanup_free_ char *raw = NULL;
+        const char *c;
+        int r;
+
+        assert(pid >= 0);
+        assert(cgroup);
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
+        if (r < 0)
+                return r;
+
+        r = cg_shift_path(raw, root, &c);
+        if (r < 0)
+                return r;
+
+        if (c == raw)
+                *cgroup = TAKE_PTR(raw);
+        else {
+                char *n;
+
+                n = strdup(c);
+                if (!n)
+                        return -ENOMEM;
+
+                *cgroup = n;
+        }
+
+        return 0;
+}
+
+int cg_path_decode_unit(const char *cgroup, char **unit) {
+        char *c, *s;
+        size_t n;
+
+        assert(cgroup);
+        assert(unit);
+
+        n = strcspn(cgroup, "/");
+        if (n < 3)
+                return -ENXIO;
+
+        c = strndupa(cgroup, n);
+        c = cg_unescape(c);
+
+        if (!unit_name_is_valid(c, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
+                return -ENXIO;
+
+        s = strdup(c);
+        if (!s)
+                return -ENOMEM;
+
+        *unit = s;
+        return 0;
+}
+
+static bool valid_slice_name(const char *p, size_t n) {
+
+        if (!p)
+                return false;
+
+        if (n < STRLEN("x.slice"))
+                return false;
+
+        if (memcmp(p + n - 6, ".slice", 6) == 0) {
+                char buf[n+1], *c;
+
+                memcpy(buf, p, n);
+                buf[n] = 0;
+
+                c = cg_unescape(buf);
+
+                return unit_name_is_valid(c, UNIT_NAME_PLAIN);
+        }
+
+        return false;
+}
+
+static const char *skip_slices(const char *p) {
+        assert(p);
+
+        /* Skips over all slice assignments */
+
+        for (;;) {
+                size_t n;
+
+                p += strspn(p, "/");
+
+                n = strcspn(p, "/");
+                if (!valid_slice_name(p, n))
+                        return p;
+
+                p += n;
+        }
+}
+
+int cg_path_get_unit(const char *path, char **ret) {
+        const char *e;
+        char *unit;
+        int r;
+
+        assert(path);
+        assert(ret);
+
+        e = skip_slices(path);
+
+        r = cg_path_decode_unit(e, &unit);
+        if (r < 0)
+                return r;
+
+        /* We skipped over the slices, don't accept any now */
+        if (endswith(unit, ".slice")) {
+                free(unit);
+                return -ENXIO;
+        }
+
+        *ret = unit;
+        return 0;
+}
+
+int cg_pid_get_unit(pid_t pid, char **unit) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        assert(unit);
+
+        r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        return cg_path_get_unit(cgroup, unit);
+}
+
+/**
+ * Skip session-*.scope, but require it to be there.
+ */
+static const char *skip_session(const char *p) {
+        size_t n;
+
+        if (isempty(p))
+                return NULL;
+
+        p += strspn(p, "/");
+
+        n = strcspn(p, "/");
+        if (n < STRLEN("session-x.scope"))
+                return NULL;
+
+        if (memcmp(p, "session-", 8) == 0 && memcmp(p + n - 6, ".scope", 6) == 0) {
+                char buf[n - 8 - 6 + 1];
+
+                memcpy(buf, p + 8, n - 8 - 6);
+                buf[n - 8 - 6] = 0;
+
+                /* Note that session scopes never need unescaping,
+                 * since they cannot conflict with the kernel's own
+                 * names, hence we don't need to call cg_unescape()
+                 * here. */
+
+                if (!session_id_valid(buf))
+                        return false;
+
+                p += n;
+                p += strspn(p, "/");
+                return p;
+        }
+
+        return NULL;
+}
+
+/**
+ * Skip user@*.service, but require it to be there.
+ */
+static const char *skip_user_manager(const char *p) {
+        size_t n;
+
+        if (isempty(p))
+                return NULL;
+
+        p += strspn(p, "/");
+
+        n = strcspn(p, "/");
+        if (n < STRLEN("user@x.service"))
+                return NULL;
+
+        if (memcmp(p, "user@", 5) == 0 && memcmp(p + n - 8, ".service", 8) == 0) {
+                char buf[n - 5 - 8 + 1];
+
+                memcpy(buf, p + 5, n - 5 - 8);
+                buf[n - 5 - 8] = 0;
+
+                /* Note that user manager services never need unescaping,
+                 * since they cannot conflict with the kernel's own
+                 * names, hence we don't need to call cg_unescape()
+                 * here. */
+
+                if (parse_uid(buf, NULL) < 0)
+                        return NULL;
+
+                p += n;
+                p += strspn(p, "/");
+
+                return p;
+        }
+
+        return NULL;
+}
+
+static const char *skip_user_prefix(const char *path) {
+        const char *e, *t;
+
+        assert(path);
+
+        /* Skip slices, if there are any */
+        e = skip_slices(path);
+
+        /* Skip the user manager, if it's in the path now... */
+        t = skip_user_manager(e);
+        if (t)
+                return t;
+
+        /* Alternatively skip the user session if it is in the path... */
+        return skip_session(e);
+}
+
+int cg_path_get_user_unit(const char *path, char **ret) {
+        const char *t;
+
+        assert(path);
+        assert(ret);
+
+        t = skip_user_prefix(path);
+        if (!t)
+                return -ENXIO;
+
+        /* And from here on it looks pretty much the same as for a
+         * system unit, hence let's use the same parser from here
+         * on. */
+        return cg_path_get_unit(t, ret);
+}
+
+int cg_pid_get_user_unit(pid_t pid, char **unit) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        assert(unit);
+
+        r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        return cg_path_get_user_unit(cgroup, unit);
+}
+
+int cg_path_get_machine_name(const char *path, char **machine) {
+        _cleanup_free_ char *u = NULL;
+        const char *sl;
+        int r;
+
+        r = cg_path_get_unit(path, &u);
+        if (r < 0)
+                return r;
+
+        sl = strjoina("/run/systemd/machines/unit:", u);
+        return readlink_malloc(sl, machine);
+}
+
+int cg_pid_get_machine_name(pid_t pid, char **machine) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        assert(machine);
+
+        r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        return cg_path_get_machine_name(cgroup, machine);
+}
+
+int cg_path_get_session(const char *path, char **session) {
+        _cleanup_free_ char *unit = NULL;
+        char *start, *end;
+        int r;
+
+        assert(path);
+
+        r = cg_path_get_unit(path, &unit);
+        if (r < 0)
+                return r;
+
+        start = startswith(unit, "session-");
+        if (!start)
+                return -ENXIO;
+        end = endswith(start, ".scope");
+        if (!end)
+                return -ENXIO;
+
+        *end = 0;
+        if (!session_id_valid(start))
+                return -ENXIO;
+
+        if (session) {
+                char *rr;
+
+                rr = strdup(start);
+                if (!rr)
+                        return -ENOMEM;
+
+                *session = rr;
+        }
+
+        return 0;
+}
+
+int cg_pid_get_session(pid_t pid, char **session) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        return cg_path_get_session(cgroup, session);
+}
+
+int cg_path_get_owner_uid(const char *path, uid_t *uid) {
+        _cleanup_free_ char *slice = NULL;
+        char *start, *end;
+        int r;
+
+        assert(path);
+
+        r = cg_path_get_slice(path, &slice);
+        if (r < 0)
+                return r;
+
+        start = startswith(slice, "user-");
+        if (!start)
+                return -ENXIO;
+        end = endswith(start, ".slice");
+        if (!end)
+                return -ENXIO;
+
+        *end = 0;
+        if (parse_uid(start, uid) < 0)
+                return -ENXIO;
+
+        return 0;
+}
+
+int cg_pid_get_owner_uid(pid_t pid, uid_t *uid) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        return cg_path_get_owner_uid(cgroup, uid);
+}
+
+int cg_path_get_slice(const char *p, char **slice) {
+        const char *e = NULL;
+
+        assert(p);
+        assert(slice);
+
+        /* Finds the right-most slice unit from the beginning, but
+         * stops before we come to the first non-slice unit. */
+
+        for (;;) {
+                size_t n;
+
+                p += strspn(p, "/");
+
+                n = strcspn(p, "/");
+                if (!valid_slice_name(p, n)) {
+
+                        if (!e) {
+                                char *s;
+
+                                s = strdup(SPECIAL_ROOT_SLICE);
+                                if (!s)
+                                        return -ENOMEM;
+
+                                *slice = s;
+                                return 0;
+                        }
+
+                        return cg_path_decode_unit(e, slice);
+                }
+
+                e = p;
+                p += n;
+        }
+}
+
+int cg_pid_get_slice(pid_t pid, char **slice) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        assert(slice);
+
+        r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        return cg_path_get_slice(cgroup, slice);
+}
+
+int cg_path_get_user_slice(const char *p, char **slice) {
+        const char *t;
+        assert(p);
+        assert(slice);
+
+        t = skip_user_prefix(p);
+        if (!t)
+                return -ENXIO;
+
+        /* And now it looks pretty much the same as for a system
+         * slice, so let's just use the same parser from here on. */
+        return cg_path_get_slice(t, slice);
+}
+
+int cg_pid_get_user_slice(pid_t pid, char **slice) {
+        _cleanup_free_ char *cgroup = NULL;
+        int r;
+
+        assert(slice);
+
+        r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        return cg_path_get_user_slice(cgroup, slice);
+}
+
+char *cg_escape(const char *p) {
+        bool need_prefix = false;
+
+        /* This implements very minimal escaping for names to be used
+         * as file names in the cgroup tree: any name which might
+         * conflict with a kernel name or is prefixed with '_' is
+         * prefixed with a '_'. That way, when reading cgroup names it
+         * is sufficient to remove a single prefixing underscore if
+         * there is one. */
+
+        /* The return value of this function (unlike cg_unescape())
+         * needs free()! */
+
+        if (IN_SET(p[0], 0, '_', '.') ||
+            STR_IN_SET(p, "notify_on_release", "release_agent", "tasks") ||
+            startswith(p, "cgroup."))
+                need_prefix = true;
+        else {
+                const char *dot;
+
+                dot = strrchr(p, '.');
+                if (dot) {
+                        CGroupController c;
+                        size_t l = dot - p;
+
+                        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                                const char *n;
+
+                                n = cgroup_controller_to_string(c);
+
+                                if (l != strlen(n))
+                                        continue;
+
+                                if (memcmp(p, n, l) != 0)
+                                        continue;
+
+                                need_prefix = true;
+                                break;
+                        }
+                }
+        }
+
+        if (need_prefix)
+                return strappend("_", p);
+
+        return strdup(p);
+}
+
+char *cg_unescape(const char *p) {
+        assert(p);
+
+        /* The return value of this function (unlike cg_escape())
+         * doesn't need free()! */
+
+        if (p[0] == '_')
+                return (char*) p+1;
+
+        return (char*) p;
+}
+
+#define CONTROLLER_VALID                        \
+        DIGITS LETTERS                          \
+        "_"
+
+bool cg_controller_is_valid(const char *p) {
+        const char *t, *s;
+
+        if (!p)
+                return false;
+
+        if (streq(p, SYSTEMD_CGROUP_CONTROLLER))
+                return true;
+
+        s = startswith(p, "name=");
+        if (s)
+                p = s;
+
+        if (IN_SET(*p, 0, '_'))
+                return false;
+
+        for (t = p; *t; t++)
+                if (!strchr(CONTROLLER_VALID, *t))
+                        return false;
+
+        if (t - p > FILENAME_MAX)
+                return false;
+
+        return true;
+}
+
+int cg_slice_to_path(const char *unit, char **ret) {
+        _cleanup_free_ char *p = NULL, *s = NULL, *e = NULL;
+        const char *dash;
+        int r;
+
+        assert(unit);
+        assert(ret);
+
+        if (streq(unit, SPECIAL_ROOT_SLICE)) {
+                char *x;
+
+                x = strdup("");
+                if (!x)
+                        return -ENOMEM;
+                *ret = x;
+                return 0;
+        }
+
+        if (!unit_name_is_valid(unit, UNIT_NAME_PLAIN))
+                return -EINVAL;
+
+        if (!endswith(unit, ".slice"))
+                return -EINVAL;
+
+        r = unit_name_to_prefix(unit, &p);
+        if (r < 0)
+                return r;
+
+        dash = strchr(p, '-');
+
+        /* Don't allow initial dashes */
+        if (dash == p)
+                return -EINVAL;
+
+        while (dash) {
+                _cleanup_free_ char *escaped = NULL;
+                char n[dash - p + sizeof(".slice")];
+
+#if HAS_FEATURE_MEMORY_SANITIZER
+                /* msan doesn't instrument stpncpy, so it thinks
+                 * n is later used unitialized:
+                 * https://github.com/google/sanitizers/issues/926
+                 */
+                zero(n);
+#endif
+
+                /* Don't allow trailing or double dashes */
+                if (IN_SET(dash[1], 0, '-'))
+                        return -EINVAL;
+
+                strcpy(stpncpy(n, p, dash - p), ".slice");
+                if (!unit_name_is_valid(n, UNIT_NAME_PLAIN))
+                        return -EINVAL;
+
+                escaped = cg_escape(n);
+                if (!escaped)
+                        return -ENOMEM;
+
+                if (!strextend(&s, escaped, "/", NULL))
+                        return -ENOMEM;
+
+                dash = strchr(dash+1, '-');
+        }
+
+        e = cg_escape(unit);
+        if (!e)
+                return -ENOMEM;
+
+        if (!strextend(&s, e, NULL))
+                return -ENOMEM;
+
+        *ret = TAKE_PTR(s);
+
+        return 0;
+}
+
+int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        r = cg_get_path(controller, path, attribute, &p);
+        if (r < 0)
+                return r;
+
+        return write_string_file(p, value, WRITE_STRING_FILE_DISABLE_BUFFER);
+}
+
+int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        r = cg_get_path(controller, path, attribute, &p);
+        if (r < 0)
+                return r;
+
+        return read_one_line_file(p, ret);
+}
+
+int cg_get_keyed_attribute(
+                const char *controller,
+                const char *path,
+                const char *attribute,
+                char **keys,
+                char **ret_values) {
+
+        _cleanup_free_ char *filename = NULL, *contents = NULL;
+        const char *p;
+        size_t n, i, n_done = 0;
+        char **v;
+        int r;
+
+        /* Reads one or more fields of a cgroup v2 keyed attribute file. The 'keys' parameter should be an strv with
+         * all keys to retrieve. The 'ret_values' parameter should be passed as string size with the same number of
+         * entries as 'keys'. On success each entry will be set to the value of the matching key.
+         *
+         * If the attribute file doesn't exist at all returns ENOENT, if any key is not found returns ENXIO. */
+
+        r = cg_get_path(controller, path, attribute, &filename);
+        if (r < 0)
+                return r;
+
+        r = read_full_file(filename, &contents, NULL);
+        if (r < 0)
+                return r;
+
+        n = strv_length(keys);
+        if (n == 0) /* No keys to retrieve? That's easy, we are done then */
+                return 0;
+
+        /* Let's build this up in a temporary array for now in order not to clobber the return parameter on failure */
+        v = newa0(char*, n);
+
+        for (p = contents; *p;) {
+                const char *w = NULL;
+
+                for (i = 0; i < n; i++)
+                        if (!v[i]) {
+                                w = first_word(p, keys[i]);
+                                if (w)
+                                        break;
+                        }
+
+                if (w) {
+                        size_t l;
+
+                        l = strcspn(w, NEWLINE);
+                        v[i] = strndup(w, l);
+                        if (!v[i]) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
+
+                        n_done++;
+                        if (n_done >= n)
+                                goto done;
+
+                        p = w + l;
+                } else
+                        p += strcspn(p, NEWLINE);
+
+                p += strspn(p, NEWLINE);
+        }
+
+        r = -ENXIO;
+
+fail:
+        for (i = 0; i < n; i++)
+                free(v[i]);
+
+        return r;
+
+done:
+        memcpy(ret_values, v, sizeof(char*) * n);
+        return 0;
+
+}
+
+int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path) {
+        CGroupController c;
+        CGroupMask done;
+        bool created;
+        int r;
+
+        /* This one will create a cgroup in our private tree, but also
+         * duplicate it in the trees specified in mask, and remove it
+         * in all others.
+         *
+         * Returns 0 if the group already existed in the systemd hierarchy,
+         * 1 on success, negative otherwise.
+         */
+
+        /* First create the cgroup in our own hierarchy. */
+        r = cg_create(SYSTEMD_CGROUP_CONTROLLER, path);
+        if (r < 0)
+                return r;
+        created = r;
+
+        /* If we are in the unified hierarchy, we are done now */
+        r = cg_all_unified();
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return created;
+
+        supported &= CGROUP_MASK_V1;
+        mask = CGROUP_MASK_EXTEND_JOINED(mask);
+        done = 0;
+
+        /* Otherwise, do the same in the other hierarchies */
+        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
+                const char *n;
+
+                if (!FLAGS_SET(supported, bit))
+                        continue;
+
+                if (FLAGS_SET(done, bit))
+                        continue;
+
+                n = cgroup_controller_to_string(c);
+                if (FLAGS_SET(mask, bit))
+                        (void) cg_create(n, path);
+                else
+                        (void) cg_trim(n, path, true);
+
+                done |= CGROUP_MASK_EXTEND_JOINED(bit);
+        }
+
+        return created;
+}
+
+int cg_attach_everywhere(CGroupMask supported, const char *path, pid_t pid, cg_migrate_callback_t path_callback, void *userdata) {
+        CGroupController c;
+        CGroupMask done;
+        int r;
+
+        r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid);
+        if (r < 0)
+                return r;
+
+        r = cg_all_unified();
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return 0;
+
+        supported &= CGROUP_MASK_V1;
+        done = 0;
+
+        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
+                const char *p = NULL;
+
+                if (!FLAGS_SET(supported, bit))
+                        continue;
+
+                if (FLAGS_SET(done, bit))
+                        continue;
+
+                if (path_callback)
+                        p = path_callback(bit, userdata);
+                if (!p)
+                        p = path;
+
+                (void) cg_attach_fallback(cgroup_controller_to_string(c), p, pid);
+                done |= CGROUP_MASK_EXTEND_JOINED(bit);
+        }
+
+        return 0;
+}
+
+int cg_attach_many_everywhere(CGroupMask supported, const char *path, Set* pids, cg_migrate_callback_t path_callback, void *userdata) {
+        Iterator i;
+        void *pidp;
+        int r = 0;
+
+        SET_FOREACH(pidp, pids, i) {
+                pid_t pid = PTR_TO_PID(pidp);
+                int q;
+
+                q = cg_attach_everywhere(supported, path, pid, path_callback, userdata);
+                if (q < 0 && r >= 0)
+                        r = q;
+        }
+
+        return r;
+}
+
+int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) {
+        CGroupController c;
+        CGroupMask done;
+        int r = 0, q;
+
+        if (!path_equal(from, to))  {
+                r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, CGROUP_REMOVE);
+                if (r < 0)
+                        return r;
+        }
+
+        q = cg_all_unified();
+        if (q < 0)
+                return q;
+        if (q > 0)
+                return r;
+
+        supported &= CGROUP_MASK_V1;
+        done = 0;
+
+        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
+                const char *p = NULL;
+
+                if (!FLAGS_SET(supported, bit))
+                        continue;
+
+                if (FLAGS_SET(done, bit))
+                        continue;
+
+                if (to_callback)
+                        p = to_callback(bit, userdata);
+                if (!p)
+                        p = to;
+
+                (void) cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, cgroup_controller_to_string(c), p, 0);
+                done |= CGROUP_MASK_EXTEND_JOINED(bit);
+        }
+
+        return r;
+}
+
+int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root) {
+        CGroupController c;
+        CGroupMask done;
+        int r, q;
+
+        r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root);
+        if (r < 0)
+                return r;
+
+        q = cg_all_unified();
+        if (q < 0)
+                return q;
+        if (q > 0)
+                return r;
+
+        supported &= CGROUP_MASK_V1;
+        done = 0;
+
+        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
+
+                if (!FLAGS_SET(supported, bit))
+                        continue;
+
+                if (FLAGS_SET(done, bit))
+                        continue;
+
+                (void) cg_trim(cgroup_controller_to_string(c), path, delete_root);
+                done |= CGROUP_MASK_EXTEND_JOINED(bit);
+        }
+
+        return r;
+}
+
+int cg_mask_to_string(CGroupMask mask, char **ret) {
+        _cleanup_free_ char *s = NULL;
+        size_t n = 0, allocated = 0;
+        bool space = false;
+        CGroupController c;
+
+        assert(ret);
+
+        if (mask == 0) {
+                *ret = NULL;
+                return 0;
+        }
+
+        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                const char *k;
+                size_t l;
+
+                if (!FLAGS_SET(mask, CGROUP_CONTROLLER_TO_MASK(c)))
+                        continue;
+
+                k = cgroup_controller_to_string(c);
+                l = strlen(k);
+
+                if (!GREEDY_REALLOC(s, allocated, n + space + l + 1))
+                        return -ENOMEM;
+
+                if (space)
+                        s[n] = ' ';
+                memcpy(s + n + space, k, l);
+                n += space + l;
+
+                space = true;
+        }
+
+        assert(s);
+
+        s[n] = 0;
+        *ret = TAKE_PTR(s);
+
+        return 0;
+}
+
+int cg_mask_from_string(const char *value, CGroupMask *ret) {
+        CGroupMask m = 0;
+
+        assert(ret);
+        assert(value);
+
+        for (;;) {
+                _cleanup_free_ char *n = NULL;
+                CGroupController v;
+                int r;
+
+                r = extract_first_word(&value, &n, NULL, 0);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                v = cgroup_controller_from_string(n);
+                if (v < 0)
+                        continue;
+
+                m |= CGROUP_CONTROLLER_TO_MASK(v);
+        }
+
+        *ret = m;
+        return 0;
+}
+
+int cg_mask_supported(CGroupMask *ret) {
+        CGroupMask mask;
+        int r;
+
+        /* Determines the mask of supported cgroup controllers. Only includes controllers we can make sense of and that
+         * are actually accessible. Only covers real controllers, i.e. not the CGROUP_CONTROLLER_BPF_xyz
+         * pseudo-controllers. */
+
+        r = cg_all_unified();
+        if (r < 0)
+                return r;
+        if (r > 0) {
+                _cleanup_free_ char *root = NULL, *controllers = NULL, *path = NULL;
+
+                /* In the unified hierarchy we can read the supported
+                 * and accessible controllers from a the top-level
+                 * cgroup attribute */
+
+                r = cg_get_root_path(&root);
+                if (r < 0)
+                        return r;
+
+                r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, root, "cgroup.controllers", &path);
+                if (r < 0)
+                        return r;
+
+                r = read_one_line_file(path, &controllers);
+                if (r < 0)
+                        return r;
+
+                r = cg_mask_from_string(controllers, &mask);
+                if (r < 0)
+                        return r;
+
+                /* Currently, we support the cpu, memory, io and pids controller in the unified hierarchy, mask
+                 * everything else off. */
+                mask &= CGROUP_MASK_V2;
+
+        } else {
+                CGroupController c;
+
+                /* In the legacy hierarchy, we check which hierarchies are mounted. */
+
+                mask = 0;
+                for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                        CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
+                        const char *n;
+
+                        if (!FLAGS_SET(CGROUP_MASK_V1, bit))
+                                continue;
+
+                        n = cgroup_controller_to_string(c);
+                        if (controller_is_accessible(n) >= 0)
+                                mask |= bit;
+                }
+        }
+
+        *ret = mask;
+        return 0;
+}
+
+int cg_kernel_controllers(Set **ret) {
+        _cleanup_set_free_free_ Set *controllers = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        assert(ret);
+
+        /* Determines the full list of kernel-known controllers. Might include controllers we don't actually support
+         * and controllers that aren't currently accessible (because not mounted). This does not include "name="
+         * pseudo-controllers. */
+
+        controllers = set_new(&string_hash_ops);
+        if (!controllers)
+                return -ENOMEM;
+
+        f = fopen("/proc/cgroups", "re");
+        if (!f) {
+                if (errno == ENOENT) {
+                        *ret = NULL;
+                        return 0;
+                }
+
+                return -errno;
+        }
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        /* Ignore the header line */
+        (void) read_line(f, (size_t) -1, NULL);
+
+        for (;;) {
+                char *controller;
+                int enabled = 0;
+
+                errno = 0;
+                if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
+
+                        if (feof(f))
+                                break;
+
+                        if (ferror(f) && errno > 0)
+                                return -errno;
+
+                        return -EBADMSG;
+                }
+
+                if (!enabled) {
+                        free(controller);
+                        continue;
+                }
+
+                if (!cg_controller_is_valid(controller)) {
+                        free(controller);
+                        return -EBADMSG;
+                }
+
+                r = set_consume(controllers, controller);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = TAKE_PTR(controllers);
+
+        return 0;
+}
+
+static thread_local CGroupUnified unified_cache = CGROUP_UNIFIED_UNKNOWN;
+
+/* The hybrid mode was initially implemented in v232 and simply mounted cgroup2 on /sys/fs/cgroup/systemd.  This
+ * unfortunately broke other tools (such as docker) which expected the v1 "name=systemd" hierarchy on
+ * /sys/fs/cgroup/systemd.  From v233 and on, the hybrid mode mountnbs v2 on /sys/fs/cgroup/unified and maintains
+ * "name=systemd" hierarchy on /sys/fs/cgroup/systemd for compatibility with other tools.
+ *
+ * To keep live upgrade working, we detect and support v232 layout.  When v232 layout is detected, to keep cgroup v2
+ * process management but disable the compat dual layout, we return %true on
+ * cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) and %false on cg_hybrid_unified().
+ */
+static thread_local bool unified_systemd_v232;
+
+static int cg_unified_update(void) {
+
+        struct statfs fs;
+
+        /* Checks if we support the unified hierarchy. Returns an
+         * error when the cgroup hierarchies aren't mounted yet or we
+         * have any other trouble determining if the unified hierarchy
+         * is supported. */
+
+        if (unified_cache >= CGROUP_UNIFIED_NONE)
+                return 0;
+
+        if (statfs("/sys/fs/cgroup/", &fs) < 0)
+                return log_debug_errno(errno, "statfs(\"/sys/fs/cgroup/\") failed: %m");
+
+        if (F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) {
+                log_debug("Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy");
+                unified_cache = CGROUP_UNIFIED_ALL;
+        } else if (F_TYPE_EQUAL(fs.f_type, TMPFS_MAGIC)) {
+                if (statfs("/sys/fs/cgroup/unified/", &fs) == 0 &&
+                    F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) {
+                        log_debug("Found cgroup2 on /sys/fs/cgroup/unified, unified hierarchy for systemd controller");
+                        unified_cache = CGROUP_UNIFIED_SYSTEMD;
+                        unified_systemd_v232 = false;
+                } else {
+                        if (statfs("/sys/fs/cgroup/systemd/", &fs) < 0)
+                                return log_debug_errno(errno, "statfs(\"/sys/fs/cgroup/systemd\" failed: %m");
+
+                        if (F_TYPE_EQUAL(fs.f_type, CGROUP2_SUPER_MAGIC)) {
+                                log_debug("Found cgroup2 on /sys/fs/cgroup/systemd, unified hierarchy for systemd controller (v232 variant)");
+                                unified_cache = CGROUP_UNIFIED_SYSTEMD;
+                                unified_systemd_v232 = true;
+                        } else if (F_TYPE_EQUAL(fs.f_type, CGROUP_SUPER_MAGIC)) {
+                                log_debug("Found cgroup on /sys/fs/cgroup/systemd, legacy hierarchy");
+                                unified_cache = CGROUP_UNIFIED_NONE;
+                        } else {
+                                log_debug("Unexpected filesystem type %llx mounted on /sys/fs/cgroup/systemd, assuming legacy hierarchy",
+                                          (unsigned long long) fs.f_type);
+                                unified_cache = CGROUP_UNIFIED_NONE;
+                        }
+                }
+        } else
+                return log_debug_errno(SYNTHETIC_ERRNO(ENOMEDIUM),
+                                       "Unknown filesystem type %llx mounted on /sys/fs/cgroup.",
+                                       (unsigned long long)fs.f_type);
+
+        return 0;
+}
+
+int cg_unified_controller(const char *controller) {
+        int r;
+
+        r = cg_unified_update();
+        if (r < 0)
+                return r;
+
+        if (unified_cache == CGROUP_UNIFIED_NONE)
+                return false;
+
+        if (unified_cache >= CGROUP_UNIFIED_ALL)
+                return true;
+
+        return streq_ptr(controller, SYSTEMD_CGROUP_CONTROLLER);
+}
+
+int cg_all_unified(void) {
+        int r;
+
+        r = cg_unified_update();
+        if (r < 0)
+                return r;
+
+        return unified_cache >= CGROUP_UNIFIED_ALL;
+}
+
+int cg_hybrid_unified(void) {
+        int r;
+
+        r = cg_unified_update();
+        if (r < 0)
+                return r;
+
+        return unified_cache == CGROUP_UNIFIED_SYSTEMD && !unified_systemd_v232;
+}
+
+int cg_unified_flush(void) {
+        unified_cache = CGROUP_UNIFIED_UNKNOWN;
+
+        return cg_unified_update();
+}
+
+int cg_enable_everywhere(
+                CGroupMask supported,
+                CGroupMask mask,
+                const char *p,
+                CGroupMask *ret_result_mask) {
+
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *fs = NULL;
+        CGroupController c;
+        CGroupMask ret = 0;
+        int r;
+
+        assert(p);
+
+        if (supported == 0) {
+                if (ret_result_mask)
+                        *ret_result_mask = 0;
+                return 0;
+        }
+
+        r = cg_all_unified();
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                /* On the legacy hiearchy there's no concept of "enabling" controllers in cgroups defined. Let's claim
+                 * complete success right away. (If you wonder why we return the full mask here, rather than zero: the
+                 * caller tends to use the returned mask later on to compare if all controllers where properly joined,
+                 * and if not requeues realization. This use is the primary purpose of the return value, hence let's
+                 * minimize surprises here and reduce triggers for re-realization by always saying we fully
+                 * succeeded.) */
+                if (ret_result_mask)
+                        *ret_result_mask = mask & supported & CGROUP_MASK_V2; /* If you wonder why we mask this with
+                                                                               * CGROUP_MASK_V2: The 'supported' mask
+                                                                               * might contain pure-V1 or BPF
+                                                                               * controllers, and we never want to
+                                                                               * claim that we could enable those with
+                                                                               * cgroup.subtree_control */
+                return 0;
+        }
+
+        r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, p, "cgroup.subtree_control", &fs);
+        if (r < 0)
+                return r;
+
+        for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) {
+                CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c);
+                const char *n;
+
+                if (!FLAGS_SET(CGROUP_MASK_V2, bit))
+                        continue;
+
+                if (!FLAGS_SET(supported, bit))
+                        continue;
+
+                n = cgroup_controller_to_string(c);
+                {
+                        char s[1 + strlen(n) + 1];
+
+                        s[0] = FLAGS_SET(mask, bit) ? '+' : '-';
+                        strcpy(s + 1, n);
+
+                        if (!f) {
+                                f = fopen(fs, "we");
+                                if (!f)
+                                        return log_debug_errno(errno, "Failed to open cgroup.subtree_control file of %s: %m", p);
+                        }
+
+                        r = write_string_stream(f, s, WRITE_STRING_FILE_DISABLE_BUFFER);
+                        if (r < 0) {
+                                log_debug_errno(r, "Failed to %s controller %s for %s (%s): %m",
+                                                FLAGS_SET(mask, bit) ? "enable" : "disable", n, p, fs);
+                                clearerr(f);
+
+                                /* If we can't turn off a controller, leave it on in the reported resulting mask. This
+                                 * happens for example when we attempt to turn off a controller up in the tree that is
+                                 * used down in the tree. */
+                                if (!FLAGS_SET(mask, bit) && r == -EBUSY) /* You might wonder why we check for EBUSY
+                                                                           * only here, and not follow the same logic
+                                                                           * for other errors such as EINVAL or
+                                                                           * EOPNOTSUPP or anything else. That's
+                                                                           * because EBUSY indicates that the
+                                                                           * controllers is currently enabled and
+                                                                           * cannot be disabled because something down
+                                                                           * the hierarchy is still using it. Any other
+                                                                           * error most likely means something like "I
+                                                                           * never heard of this controller" or
+                                                                           * similar. In the former case it's hence
+                                                                           * safe to assume the controller is still on
+                                                                           * after the failed operation, while in the
+                                                                           * latter case it's safer to assume the
+                                                                           * controller is unknown and hence certainly
+                                                                           * not enabled. */
+                                        ret |= bit;
+                        } else {
+                                /* Otherwise, if we managed to turn on a controller, set the bit reflecting that. */
+                                if (FLAGS_SET(mask, bit))
+                                        ret |= bit;
+                        }
+                }
+        }
+
+        /* Let's return the precise set of controllers now enabled for the cgroup. */
+        if (ret_result_mask)
+                *ret_result_mask = ret;
+
+        return 0;
+}
+
+bool cg_is_unified_wanted(void) {
+        static thread_local int wanted = -1;
+        int r;
+        bool b;
+        const bool is_default = DEFAULT_HIERARCHY == CGROUP_UNIFIED_ALL;
+        _cleanup_free_ char *c = NULL;
+
+        /* If we have a cached value, return that. */
+        if (wanted >= 0)
+                return wanted;
+
+        /* If the hierarchy is already mounted, then follow whatever
+         * was chosen for it. */
+        if (cg_unified_flush() >= 0)
+                return (wanted = unified_cache >= CGROUP_UNIFIED_ALL);
+
+        /* If we were explicitly passed systemd.unified_cgroup_hierarchy,
+         * respect that. */
+        r = proc_cmdline_get_bool("systemd.unified_cgroup_hierarchy", &b);
+        if (r > 0)
+                return (wanted = b);
+
+        /* If we passed cgroup_no_v1=all with no other instructions, it seems
+         * highly unlikely that we want to use hybrid or legacy hierarchy. */
+        r = proc_cmdline_get_key("cgroup_no_v1", 0, &c);
+        if (r > 0 && streq_ptr(c, "all"))
+                return (wanted = true);
+
+        return (wanted = is_default);
+}
+
+bool cg_is_legacy_wanted(void) {
+        static thread_local int wanted = -1;
+
+        /* If we have a cached value, return that. */
+        if (wanted >= 0)
+                return wanted;
+
+        /* Check if we have cgroup v2 already mounted. */
+        if (cg_unified_flush() >= 0 &&
+            unified_cache == CGROUP_UNIFIED_ALL)
+                return (wanted = false);
+
+        /* Otherwise, assume that at least partial legacy is wanted,
+         * since cgroup v2 should already be mounted at this point. */
+        return (wanted = true);
+}
+
+bool cg_is_hybrid_wanted(void) {
+        static thread_local int wanted = -1;
+        int r;
+        bool b;
+        const bool is_default = DEFAULT_HIERARCHY >= CGROUP_UNIFIED_SYSTEMD;
+        /* We default to true if the default is "hybrid", obviously,
+         * but also when the default is "unified", because if we get
+         * called, it means that unified hierarchy was not mounted. */
+
+        /* If we have a cached value, return that. */
+        if (wanted >= 0)
+                return wanted;
+
+        /* If the hierarchy is already mounted, then follow whatever
+         * was chosen for it. */
+        if (cg_unified_flush() >= 0 &&
+            unified_cache == CGROUP_UNIFIED_ALL)
+                return (wanted = false);
+
+        /* Otherwise, let's see what the kernel command line has to say.
+         * Since checking is expensive, cache a non-error result. */
+        r = proc_cmdline_get_bool("systemd.legacy_systemd_cgroup_controller", &b);
+
+        /* The meaning of the kernel option is reversed wrt. to the return value
+         * of this function, hence the negation. */
+        return (wanted = r > 0 ? !b : is_default);
+}
+
+int cg_weight_parse(const char *s, uint64_t *ret) {
+        uint64_t u;
+        int r;
+
+        if (isempty(s)) {
+                *ret = CGROUP_WEIGHT_INVALID;
+                return 0;
+        }
+
+        r = safe_atou64(s, &u);
+        if (r < 0)
+                return r;
+
+        if (u < CGROUP_WEIGHT_MIN || u > CGROUP_WEIGHT_MAX)
+                return -ERANGE;
+
+        *ret = u;
+        return 0;
+}
+
+const uint64_t cgroup_io_limit_defaults[_CGROUP_IO_LIMIT_TYPE_MAX] = {
+        [CGROUP_IO_RBPS_MAX]    = CGROUP_LIMIT_MAX,
+        [CGROUP_IO_WBPS_MAX]    = CGROUP_LIMIT_MAX,
+        [CGROUP_IO_RIOPS_MAX]   = CGROUP_LIMIT_MAX,
+        [CGROUP_IO_WIOPS_MAX]   = CGROUP_LIMIT_MAX,
+};
+
+static const char* const cgroup_io_limit_type_table[_CGROUP_IO_LIMIT_TYPE_MAX] = {
+        [CGROUP_IO_RBPS_MAX]    = "IOReadBandwidthMax",
+        [CGROUP_IO_WBPS_MAX]    = "IOWriteBandwidthMax",
+        [CGROUP_IO_RIOPS_MAX]   = "IOReadIOPSMax",
+        [CGROUP_IO_WIOPS_MAX]   = "IOWriteIOPSMax",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(cgroup_io_limit_type, CGroupIOLimitType);
+
+int cg_cpu_shares_parse(const char *s, uint64_t *ret) {
+        uint64_t u;
+        int r;
+
+        if (isempty(s)) {
+                *ret = CGROUP_CPU_SHARES_INVALID;
+                return 0;
+        }
+
+        r = safe_atou64(s, &u);
+        if (r < 0)
+                return r;
+
+        if (u < CGROUP_CPU_SHARES_MIN || u > CGROUP_CPU_SHARES_MAX)
+                return -ERANGE;
+
+        *ret = u;
+        return 0;
+}
+
+int cg_blkio_weight_parse(const char *s, uint64_t *ret) {
+        uint64_t u;
+        int r;
+
+        if (isempty(s)) {
+                *ret = CGROUP_BLKIO_WEIGHT_INVALID;
+                return 0;
+        }
+
+        r = safe_atou64(s, &u);
+        if (r < 0)
+                return r;
+
+        if (u < CGROUP_BLKIO_WEIGHT_MIN || u > CGROUP_BLKIO_WEIGHT_MAX)
+                return -ERANGE;
+
+        *ret = u;
+        return 0;
+}
+
+bool is_cgroup_fs(const struct statfs *s) {
+        return is_fs_type(s, CGROUP_SUPER_MAGIC) ||
+               is_fs_type(s, CGROUP2_SUPER_MAGIC);
+}
+
+bool fd_is_cgroup_fs(int fd) {
+        struct statfs s;
+
+        if (fstatfs(fd, &s) < 0)
+                return -errno;
+
+        return is_cgroup_fs(&s);
+}
+
+static const char *cgroup_controller_table[_CGROUP_CONTROLLER_MAX] = {
+        [CGROUP_CONTROLLER_CPU] = "cpu",
+        [CGROUP_CONTROLLER_CPUACCT] = "cpuacct",
+        [CGROUP_CONTROLLER_IO] = "io",
+        [CGROUP_CONTROLLER_BLKIO] = "blkio",
+        [CGROUP_CONTROLLER_MEMORY] = "memory",
+        [CGROUP_CONTROLLER_DEVICES] = "devices",
+        [CGROUP_CONTROLLER_PIDS] = "pids",
+        [CGROUP_CONTROLLER_BPF_FIREWALL] = "bpf-firewall",
+        [CGROUP_CONTROLLER_BPF_DEVICES] = "bpf-devices",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(cgroup_controller, CGroupController);
+
+CGroupMask get_cpu_accounting_mask(void) {
+        static CGroupMask needed_mask = (CGroupMask) -1;
+
+        /* On kernel ≥4.15 with unified hierarchy, cpu.stat's usage_usec is
+         * provided externally from the CPU controller, which means we don't
+         * need to enable the CPU controller just to get metrics. This is good,
+         * because enabling the CPU controller comes at a minor performance
+         * hit, especially when it's propagated deep into large hierarchies.
+         * There's also no separate CPU accounting controller available within
+         * a unified hierarchy.
+         *
+         * This combination of factors results in the desired cgroup mask to
+         * enable for CPU accounting varying as follows:
+         *
+         *                   ╔═════════════════════╤═════════════════════╗
+         *                   ║     Linux ≥4.15     │     Linux <4.15     ║
+         *   ╔═══════════════╬═════════════════════╪═════════════════════╣
+         *   ║ Unified       ║ nothing             │ CGROUP_MASK_CPU     ║
+         *   ╟───────────────╫─────────────────────┼─────────────────────╢
+         *   ║ Hybrid/Legacy ║ CGROUP_MASK_CPUACCT │ CGROUP_MASK_CPUACCT ║
+         *   ╚═══════════════╩═════════════════════╧═════════════════════╝
+         *
+         * We check kernel version here instead of manually checking whether
+         * cpu.stat is present for every cgroup, as that check in itself would
+         * already be fairly expensive.
+         *
+         * Kernels where this patch has been backported will therefore have the
+         * CPU controller enabled unnecessarily. This is more expensive than
+         * necessary, but harmless. ☺️
+         */
+
+        if (needed_mask == (CGroupMask) -1) {
+                if (cg_all_unified()) {
+                        struct utsname u;
+                        assert_se(uname(&u) >= 0);
+
+                        if (str_verscmp(u.release, "4.15") < 0)
+                                needed_mask = CGROUP_MASK_CPU;
+                        else
+                                needed_mask = 0;
+                } else
+                        needed_mask = CGROUP_MASK_CPUACCT;
+        }
+
+        return needed_mask;
+}
+
+bool cpu_accounting_is_cheap(void) {
+        return get_cpu_accounting_mask() == 0;
+}
diff --git a/src/basic/cgroup-util.h b/src/basic/cgroup-util.h
new file mode 100644
index 0000000..119b493
--- /dev/null
+++ b/src/basic/cgroup-util.h
@@ -0,0 +1,275 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <dirent.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+
+#include "def.h"
+#include "set.h"
+
+#define SYSTEMD_CGROUP_CONTROLLER_LEGACY "name=systemd"
+#define SYSTEMD_CGROUP_CONTROLLER_HYBRID "name=unified"
+#define SYSTEMD_CGROUP_CONTROLLER "_systemd"
+
+/* An enum of well known cgroup controllers */
+typedef enum CGroupController {
+        /* Original cgroup controllers */
+        CGROUP_CONTROLLER_CPU,
+        CGROUP_CONTROLLER_CPUACCT,    /* v1 only */
+        CGROUP_CONTROLLER_IO,         /* v2 only */
+        CGROUP_CONTROLLER_BLKIO,      /* v1 only */
+        CGROUP_CONTROLLER_MEMORY,
+        CGROUP_CONTROLLER_DEVICES,    /* v1 only */
+        CGROUP_CONTROLLER_PIDS,
+
+        /* BPF-based pseudo-controllers, v2 only */
+        CGROUP_CONTROLLER_BPF_FIREWALL,
+        CGROUP_CONTROLLER_BPF_DEVICES,
+
+        _CGROUP_CONTROLLER_MAX,
+        _CGROUP_CONTROLLER_INVALID = -1,
+} CGroupController;
+
+#define CGROUP_CONTROLLER_TO_MASK(c) (1U << (c))
+
+/* A bit mask of well known cgroup controllers */
+typedef enum CGroupMask {
+        CGROUP_MASK_CPU = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_CPU),
+        CGROUP_MASK_CPUACCT = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_CPUACCT),
+        CGROUP_MASK_IO = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_IO),
+        CGROUP_MASK_BLKIO = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_BLKIO),
+        CGROUP_MASK_MEMORY = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_MEMORY),
+        CGROUP_MASK_DEVICES = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_DEVICES),
+        CGROUP_MASK_PIDS = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_PIDS),
+        CGROUP_MASK_BPF_FIREWALL = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_BPF_FIREWALL),
+        CGROUP_MASK_BPF_DEVICES = CGROUP_CONTROLLER_TO_MASK(CGROUP_CONTROLLER_BPF_DEVICES),
+
+        /* All real cgroup v1 controllers */
+        CGROUP_MASK_V1 = CGROUP_MASK_CPU|CGROUP_MASK_CPUACCT|CGROUP_MASK_BLKIO|CGROUP_MASK_MEMORY|CGROUP_MASK_DEVICES|CGROUP_MASK_PIDS,
+
+        /* All real cgroup v2 controllers */
+        CGROUP_MASK_V2 = CGROUP_MASK_CPU|CGROUP_MASK_IO|CGROUP_MASK_MEMORY|CGROUP_MASK_PIDS,
+
+        /* All cgroup v2 BPF pseudo-controllers */
+        CGROUP_MASK_BPF = CGROUP_MASK_BPF_FIREWALL|CGROUP_MASK_BPF_DEVICES,
+
+        _CGROUP_MASK_ALL = CGROUP_CONTROLLER_TO_MASK(_CGROUP_CONTROLLER_MAX) - 1
+} CGroupMask;
+
+static inline CGroupMask CGROUP_MASK_EXTEND_JOINED(CGroupMask mask) {
+        /* We always mount "cpu" and "cpuacct" in the same hierarchy. Hence, when one bit is set also set the other */
+
+        if (mask & (CGROUP_MASK_CPU|CGROUP_MASK_CPUACCT))
+                mask |= (CGROUP_MASK_CPU|CGROUP_MASK_CPUACCT);
+
+        return mask;
+}
+
+CGroupMask get_cpu_accounting_mask(void);
+bool cpu_accounting_is_cheap(void);
+
+/* Special values for all weight knobs on unified hierarchy */
+#define CGROUP_WEIGHT_INVALID ((uint64_t) -1)
+#define CGROUP_WEIGHT_MIN UINT64_C(1)
+#define CGROUP_WEIGHT_MAX UINT64_C(10000)
+#define CGROUP_WEIGHT_DEFAULT UINT64_C(100)
+
+#define CGROUP_LIMIT_MIN UINT64_C(0)
+#define CGROUP_LIMIT_MAX ((uint64_t) -1)
+
+static inline bool CGROUP_WEIGHT_IS_OK(uint64_t x) {
+        return
+            x == CGROUP_WEIGHT_INVALID ||
+            (x >= CGROUP_WEIGHT_MIN && x <= CGROUP_WEIGHT_MAX);
+}
+
+/* IO limits on unified hierarchy */
+typedef enum CGroupIOLimitType {
+        CGROUP_IO_RBPS_MAX,
+        CGROUP_IO_WBPS_MAX,
+        CGROUP_IO_RIOPS_MAX,
+        CGROUP_IO_WIOPS_MAX,
+
+        _CGROUP_IO_LIMIT_TYPE_MAX,
+        _CGROUP_IO_LIMIT_TYPE_INVALID = -1
+} CGroupIOLimitType;
+
+extern const uint64_t cgroup_io_limit_defaults[_CGROUP_IO_LIMIT_TYPE_MAX];
+
+const char* cgroup_io_limit_type_to_string(CGroupIOLimitType t) _const_;
+CGroupIOLimitType cgroup_io_limit_type_from_string(const char *s) _pure_;
+
+/* Special values for the cpu.shares attribute */
+#define CGROUP_CPU_SHARES_INVALID ((uint64_t) -1)
+#define CGROUP_CPU_SHARES_MIN UINT64_C(2)
+#define CGROUP_CPU_SHARES_MAX UINT64_C(262144)
+#define CGROUP_CPU_SHARES_DEFAULT UINT64_C(1024)
+
+static inline bool CGROUP_CPU_SHARES_IS_OK(uint64_t x) {
+        return
+            x == CGROUP_CPU_SHARES_INVALID ||
+            (x >= CGROUP_CPU_SHARES_MIN && x <= CGROUP_CPU_SHARES_MAX);
+}
+
+/* Special values for the blkio.weight attribute */
+#define CGROUP_BLKIO_WEIGHT_INVALID ((uint64_t) -1)
+#define CGROUP_BLKIO_WEIGHT_MIN UINT64_C(10)
+#define CGROUP_BLKIO_WEIGHT_MAX UINT64_C(1000)
+#define CGROUP_BLKIO_WEIGHT_DEFAULT UINT64_C(500)
+
+static inline bool CGROUP_BLKIO_WEIGHT_IS_OK(uint64_t x) {
+        return
+            x == CGROUP_BLKIO_WEIGHT_INVALID ||
+            (x >= CGROUP_BLKIO_WEIGHT_MIN && x <= CGROUP_BLKIO_WEIGHT_MAX);
+}
+
+/* Default resource limits */
+#define DEFAULT_TASKS_MAX_PERCENTAGE            15U /* 15% of PIDs, 4915 on default settings */
+#define DEFAULT_USER_TASKS_MAX_PERCENTAGE       33U /* 33% of PIDs, 10813 on default settings */
+
+typedef enum CGroupUnified {
+        CGROUP_UNIFIED_UNKNOWN = -1,
+        CGROUP_UNIFIED_NONE = 0,        /* Both systemd and controllers on legacy */
+        CGROUP_UNIFIED_SYSTEMD = 1,     /* Only systemd on unified */
+        CGROUP_UNIFIED_ALL = 2,         /* Both systemd and controllers on unified */
+} CGroupUnified;
+
+/*
+ * General rules:
+ *
+ * We accept named hierarchies in the syntax "foo" and "name=foo".
+ *
+ * We expect that named hierarchies do not conflict in name with a
+ * kernel hierarchy, modulo the "name=" prefix.
+ *
+ * We always generate "normalized" controller names, i.e. without the
+ * "name=" prefix.
+ *
+ * We require absolute cgroup paths. When returning, we will always
+ * generate paths with multiple adjacent / removed.
+ */
+
+int cg_enumerate_processes(const char *controller, const char *path, FILE **_f);
+int cg_read_pid(FILE *f, pid_t *_pid);
+int cg_read_event(const char *controller, const char *path, const char *event,
+                  char **val);
+
+int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d);
+int cg_read_subgroup(DIR *d, char **fn);
+
+typedef enum CGroupFlags {
+        CGROUP_SIGCONT     = 1 << 0,
+        CGROUP_IGNORE_SELF = 1 << 1,
+        CGROUP_REMOVE      = 1 << 2,
+} CGroupFlags;
+
+typedef void (*cg_kill_log_func_t)(pid_t pid, int sig, void *userdata);
+
+int cg_kill(const char *controller, const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
+int cg_kill_recursive(const char *controller, const char *path, int sig, CGroupFlags flags, Set *s, cg_kill_log_func_t kill_log, void *userdata);
+
+int cg_migrate(const char *cfrom, const char *pfrom, const char *cto, const char *pto, CGroupFlags flags);
+int cg_migrate_recursive(const char *cfrom, const char *pfrom, const char *cto, const char *pto, CGroupFlags flags);
+int cg_migrate_recursive_fallback(const char *cfrom, const char *pfrom, const char *cto, const char *pto, CGroupFlags flags);
+
+int cg_split_spec(const char *spec, char **controller, char **path);
+int cg_mangle_path(const char *path, char **result);
+
+int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs);
+int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs);
+
+int cg_pid_get_path(const char *controller, pid_t pid, char **path);
+
+int cg_trim(const char *controller, const char *path, bool delete_root);
+
+int cg_rmdir(const char *controller, const char *path);
+
+int cg_create(const char *controller, const char *path);
+int cg_attach(const char *controller, const char *path, pid_t pid);
+int cg_attach_fallback(const char *controller, const char *path, pid_t pid);
+int cg_create_and_attach(const char *controller, const char *path, pid_t pid);
+
+int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value);
+int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret);
+int cg_get_keyed_attribute(const char *controller, const char *path, const char *attribute, char **keys, char **values);
+
+int cg_set_access(const char *controller, const char *path, uid_t uid, gid_t gid);
+
+int cg_set_xattr(const char *controller, const char *path, const char *name, const void *value, size_t size, int flags);
+int cg_get_xattr(const char *controller, const char *path, const char *name, void *value, size_t size);
+
+int cg_install_release_agent(const char *controller, const char *agent);
+int cg_uninstall_release_agent(const char *controller);
+
+int cg_is_empty(const char *controller, const char *path);
+int cg_is_empty_recursive(const char *controller, const char *path);
+
+int cg_get_root_path(char **path);
+
+int cg_path_get_session(const char *path, char **session);
+int cg_path_get_owner_uid(const char *path, uid_t *uid);
+int cg_path_get_unit(const char *path, char **unit);
+int cg_path_get_user_unit(const char *path, char **unit);
+int cg_path_get_machine_name(const char *path, char **machine);
+int cg_path_get_slice(const char *path, char **slice);
+int cg_path_get_user_slice(const char *path, char **slice);
+
+int cg_shift_path(const char *cgroup, const char *cached_root, const char **shifted);
+int cg_pid_get_path_shifted(pid_t pid, const char *cached_root, char **cgroup);
+
+int cg_pid_get_session(pid_t pid, char **session);
+int cg_pid_get_owner_uid(pid_t pid, uid_t *uid);
+int cg_pid_get_unit(pid_t pid, char **unit);
+int cg_pid_get_user_unit(pid_t pid, char **unit);
+int cg_pid_get_machine_name(pid_t pid, char **machine);
+int cg_pid_get_slice(pid_t pid, char **slice);
+int cg_pid_get_user_slice(pid_t pid, char **slice);
+
+int cg_path_decode_unit(const char *cgroup, char **unit);
+
+char *cg_escape(const char *p);
+char *cg_unescape(const char *p) _pure_;
+
+bool cg_controller_is_valid(const char *p);
+
+int cg_slice_to_path(const char *unit, char **ret);
+
+typedef const char* (*cg_migrate_callback_t)(CGroupMask mask, void *userdata);
+
+int cg_create_everywhere(CGroupMask supported, CGroupMask mask, const char *path);
+int cg_attach_everywhere(CGroupMask supported, const char *path, pid_t pid, cg_migrate_callback_t callback, void *userdata);
+int cg_attach_many_everywhere(CGroupMask supported, const char *path, Set* pids, cg_migrate_callback_t callback, void *userdata);
+int cg_migrate_everywhere(CGroupMask supported, const char *from, const char *to, cg_migrate_callback_t callback, void *userdata);
+int cg_trim_everywhere(CGroupMask supported, const char *path, bool delete_root);
+int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p, CGroupMask *ret_result_mask);
+
+int cg_mask_supported(CGroupMask *ret);
+int cg_mask_from_string(const char *s, CGroupMask *ret);
+int cg_mask_to_string(CGroupMask mask, char **ret);
+
+int cg_kernel_controllers(Set **controllers);
+
+bool cg_ns_supported(void);
+
+int cg_all_unified(void);
+int cg_hybrid_unified(void);
+int cg_unified_controller(const char *controller);
+int cg_unified_flush(void);
+
+bool cg_is_unified_wanted(void);
+bool cg_is_legacy_wanted(void);
+bool cg_is_hybrid_wanted(void);
+
+const char* cgroup_controller_to_string(CGroupController c) _const_;
+CGroupController cgroup_controller_from_string(const char *s) _pure_;
+
+int cg_weight_parse(const char *s, uint64_t *ret);
+int cg_cpu_shares_parse(const char *s, uint64_t *ret);
+int cg_blkio_weight_parse(const char *s, uint64_t *ret);
+
+bool is_cgroup_fs(const struct statfs *s);
+bool fd_is_cgroup_fs(int fd);
diff --git a/src/basic/chattr-util.c b/src/basic/chattr-util.c
new file mode 100644
index 0000000..235cfb9
--- /dev/null
+++ b/src/basic/chattr-util.c
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <linux/fs.h>
+
+#include "chattr-util.h"
+#include "fd-util.h"
+#include "macro.h"
+
+int chattr_fd(int fd, unsigned value, unsigned mask, unsigned *previous) {
+        unsigned old_attr, new_attr;
+        struct stat st;
+
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        /* Explicitly check whether this is a regular file or
+         * directory. If it is anything else (such as a device node or
+         * fifo), then the ioctl will not hit the file systems but
+         * possibly drivers, where the ioctl might have different
+         * effects. Notably, DRM is using the same ioctl() number. */
+
+        if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
+                return -ENOTTY;
+
+        if (mask == 0 && !previous)
+                return 0;
+
+        if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0)
+                return -errno;
+
+        new_attr = (old_attr & ~mask) | (value & mask);
+        if (new_attr == old_attr) {
+                if (previous)
+                        *previous = old_attr;
+                return 0;
+        }
+
+        if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) < 0)
+                return -errno;
+
+        if (previous)
+                *previous = old_attr;
+
+        return 1;
+}
+
+int chattr_path(const char *p, unsigned value, unsigned mask, unsigned *previous) {
+        _cleanup_close_ int fd = -1;
+
+        assert(p);
+
+        if (mask == 0)
+                return 0;
+
+        fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return chattr_fd(fd, value, mask, previous);
+}
+
+int read_attr_fd(int fd, unsigned *ret) {
+        struct stat st;
+
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
+                return -ENOTTY;
+
+        if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int read_attr_path(const char *p, unsigned *ret) {
+        _cleanup_close_ int fd = -1;
+
+        assert(p);
+        assert(ret);
+
+        fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0)
+                return -errno;
+
+        return read_attr_fd(fd, ret);
+}
diff --git a/src/basic/chattr-util.h b/src/basic/chattr-util.h
new file mode 100644
index 0000000..7570bba
--- /dev/null
+++ b/src/basic/chattr-util.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+int chattr_fd(int fd, unsigned value, unsigned mask, unsigned *previous);
+int chattr_path(const char *p, unsigned value, unsigned mask, unsigned *previous);
+
+int read_attr_fd(int fd, unsigned *ret);
+int read_attr_path(const char *p, unsigned *ret);
diff --git a/src/basic/conf-files.c b/src/basic/conf-files.c
new file mode 100644
index 0000000..b70c6e5
--- /dev/null
+++ b/src/basic/conf-files.c
@@ -0,0 +1,325 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "conf-files.h"
+#include "def.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "hashmap.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "path-util.h"
+#include "set.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
+#include "util.h"
+
+static int files_add(
+                Hashmap *h,
+                Set *masked,
+                const char *suffix,
+                const char *root,
+                unsigned flags,
+                const char *path) {
+
+        _cleanup_closedir_ DIR *dir = NULL;
+        const char *dirpath;
+        struct dirent *de;
+        int r;
+
+        assert(h);
+        assert((flags & CONF_FILES_FILTER_MASKED) == 0 || masked);
+        assert(path);
+
+        dirpath = prefix_roota(root, path);
+
+        dir = opendir(dirpath);
+        if (!dir) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_debug_errno(errno, "Failed to open directory '%s': %m", dirpath);
+        }
+
+        FOREACH_DIRENT(de, dir, return -errno) {
+                struct stat st;
+                char *p, *key;
+
+                /* Does this match the suffix? */
+                if (suffix && !endswith(de->d_name, suffix))
+                        continue;
+
+                /* Has this file already been found in an earlier directory? */
+                if (hashmap_contains(h, de->d_name)) {
+                        log_debug("Skipping overridden file '%s/%s'.", dirpath, de->d_name);
+                        continue;
+                }
+
+                /* Has this been masked in an earlier directory? */
+                if ((flags & CONF_FILES_FILTER_MASKED) && set_contains(masked, de->d_name)) {
+                        log_debug("File '%s/%s' is masked by previous entry.", dirpath, de->d_name);
+                        continue;
+                }
+
+                /* Read file metadata if we shall validate the check for file masks, for node types or whether the node is marked executable. */
+                if (flags & (CONF_FILES_FILTER_MASKED|CONF_FILES_REGULAR|CONF_FILES_DIRECTORY|CONF_FILES_EXECUTABLE))
+                        if (fstatat(dirfd(dir), de->d_name, &st, 0) < 0) {
+                                log_debug_errno(errno, "Failed to stat '%s/%s', ignoring: %m", dirpath, de->d_name);
+                                continue;
+                        }
+
+                /* Is this a masking entry? */
+                if ((flags & CONF_FILES_FILTER_MASKED))
+                        if (null_or_empty(&st)) {
+                                /* Mark this one as masked */
+                                r = set_put_strdup(masked, de->d_name);
+                                if (r < 0)
+                                        return r;
+
+                                log_debug("File '%s/%s' is a mask.", dirpath, de->d_name);
+                                continue;
+                        }
+
+                /* Does this node have the right type? */
+                if (flags & (CONF_FILES_REGULAR|CONF_FILES_DIRECTORY))
+                        if (!((flags & CONF_FILES_DIRECTORY) && S_ISDIR(st.st_mode)) &&
+                            !((flags & CONF_FILES_REGULAR) && S_ISREG(st.st_mode))) {
+                                log_debug("Ignoring '%s/%s', as it is not a of the right type.", dirpath, de->d_name);
+                                continue;
+                        }
+
+                /* Does this node have the executable bit set? */
+                if (flags & CONF_FILES_EXECUTABLE)
+                        /* As requested: check if the file is marked exectuable. Note that we don't check access(X_OK)
+                         * here, as we care about whether the file is marked executable at all, and not whether it is
+                         * executable for us, because if so, such errors are stuff we should log about. */
+
+                        if ((st.st_mode & 0111) == 0) { /* not executable */
+                                log_debug("Ignoring '%s/%s', as it is not marked executable.", dirpath, de->d_name);
+                                continue;
+                        }
+
+                if (flags & CONF_FILES_BASENAME) {
+                        p = strdup(de->d_name);
+                        if (!p)
+                                return -ENOMEM;
+
+                        key = p;
+                } else {
+                        p = strjoin(dirpath, "/", de->d_name);
+                        if (!p)
+                                return -ENOMEM;
+
+                        key = basename(p);
+                }
+
+                r = hashmap_put(h, key, p);
+                if (r < 0) {
+                        free(p);
+                        return log_debug_errno(r, "Failed to add item to hashmap: %m");
+                }
+
+                assert(r > 0);
+        }
+
+        return 0;
+}
+
+static int base_cmp(char * const *a, char * const *b) {
+        return strcmp(basename(*a), basename(*b));
+}
+
+static int conf_files_list_strv_internal(char ***strv, const char *suffix, const char *root, unsigned flags, char **dirs) {
+        _cleanup_hashmap_free_ Hashmap *fh = NULL;
+        _cleanup_set_free_free_ Set *masked = NULL;
+        char **files, **p;
+        int r;
+
+        assert(strv);
+
+        /* This alters the dirs string array */
+        if (!path_strv_resolve_uniq(dirs, root))
+                return -ENOMEM;
+
+        fh = hashmap_new(&path_hash_ops);
+        if (!fh)
+                return -ENOMEM;
+
+        if (flags & CONF_FILES_FILTER_MASKED) {
+                masked = set_new(&path_hash_ops);
+                if (!masked)
+                        return -ENOMEM;
+        }
+
+        STRV_FOREACH(p, dirs) {
+                r = files_add(fh, masked, suffix, root, flags, *p);
+                if (r == -ENOMEM)
+                        return r;
+                if (r < 0)
+                        log_debug_errno(r, "Failed to search for files in %s, ignoring: %m", *p);
+        }
+
+        files = hashmap_get_strv(fh);
+        if (!files)
+                return -ENOMEM;
+
+        typesafe_qsort(files, hashmap_size(fh), base_cmp);
+        *strv = files;
+
+        return 0;
+}
+
+int conf_files_insert(char ***strv, const char *root, char **dirs, const char *path) {
+        /* Insert a path into strv, at the place honouring the usual sorting rules:
+         * - we first compare by the basename
+         * - and then we compare by dirname, allowing just one file with the given
+         *   basename.
+         * This means that we will
+         * - add a new entry if basename(path) was not on the list,
+         * - do nothing if an entry with higher priority was already present,
+         * - do nothing if our new entry matches the existing entry,
+         * - replace the existing entry if our new entry has higher priority.
+         */
+        size_t i, n;
+        char *t;
+        int r;
+
+        n = strv_length(*strv);
+        for (i = 0; i < n; i++) {
+                int c;
+
+                c = base_cmp((char* const*) *strv + i, (char* const*) &path);
+                if (c == 0) {
+                        char **dir;
+
+                        /* Oh, there already is an entry with a matching name (the last component). */
+
+                        STRV_FOREACH(dir, dirs) {
+                                _cleanup_free_ char *rdir = NULL;
+                                char *p1, *p2;
+
+                                rdir = prefix_root(root, *dir);
+                                if (!rdir)
+                                        return -ENOMEM;
+
+                                p1 = path_startswith((*strv)[i], rdir);
+                                if (p1)
+                                        /* Existing entry with higher priority
+                                         * or same priority, no need to do anything. */
+                                        return 0;
+
+                                p2 = path_startswith(path, *dir);
+                                if (p2) {
+                                        /* Our new entry has higher priority */
+
+                                        t = prefix_root(root, path);
+                                        if (!t)
+                                                return log_oom();
+
+                                        return free_and_replace((*strv)[i], t);
+                                }
+                        }
+
+                } else if (c > 0)
+                        /* Following files have lower priority, let's go insert our
+                         * new entry. */
+                        break;
+
+                /* … we are not there yet, let's continue */
+        }
+
+        /* The new file has lower priority than all the existing entries */
+        t = prefix_root(root, path);
+        if (!t)
+                return -ENOMEM;
+
+        r = strv_insert(strv, i, t);
+        if (r < 0)
+                free(t);
+
+        return r;
+}
+
+int conf_files_list_strv(char ***strv, const char *suffix, const char *root, unsigned flags, const char* const* dirs) {
+        _cleanup_strv_free_ char **copy = NULL;
+
+        assert(strv);
+
+        copy = strv_copy((char**) dirs);
+        if (!copy)
+                return -ENOMEM;
+
+        return conf_files_list_strv_internal(strv, suffix, root, flags, copy);
+}
+
+int conf_files_list(char ***strv, const char *suffix, const char *root, unsigned flags, const char *dir, ...) {
+        _cleanup_strv_free_ char **dirs = NULL;
+        va_list ap;
+
+        assert(strv);
+
+        va_start(ap, dir);
+        dirs = strv_new_ap(dir, ap);
+        va_end(ap);
+
+        if (!dirs)
+                return -ENOMEM;
+
+        return conf_files_list_strv_internal(strv, suffix, root, flags, dirs);
+}
+
+int conf_files_list_nulstr(char ***strv, const char *suffix, const char *root, unsigned flags, const char *dirs) {
+        _cleanup_strv_free_ char **d = NULL;
+
+        assert(strv);
+
+        d = strv_split_nulstr(dirs);
+        if (!d)
+                return -ENOMEM;
+
+        return conf_files_list_strv_internal(strv, suffix, root, flags, d);
+}
+
+int conf_files_list_with_replacement(
+                const char *root,
+                char **config_dirs,
+                const char *replacement,
+                char ***files,
+                char **replace_file) {
+
+        _cleanup_strv_free_ char **f = NULL;
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        assert(config_dirs);
+        assert(files);
+        assert(replace_file || !replacement);
+
+        r = conf_files_list_strv(&f, ".conf", root, 0, (const char* const*) config_dirs);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enumerate config files: %m");
+
+        if (replacement) {
+                r = conf_files_insert(&f, root, config_dirs, replacement);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to extend config file list: %m");
+
+                p = prefix_root(root, replacement);
+                if (!p)
+                        return log_oom();
+        }
+
+        *files = TAKE_PTR(f);
+        if (replace_file)
+                *replace_file = TAKE_PTR(p);
+        return 0;
+}
diff --git a/src/basic/conf-files.h b/src/basic/conf-files.h
new file mode 100644
index 0000000..55ab326
--- /dev/null
+++ b/src/basic/conf-files.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "macro.h"
+
+enum {
+        CONF_FILES_EXECUTABLE    = 1 << 0,
+        CONF_FILES_REGULAR       = 1 << 1,
+        CONF_FILES_DIRECTORY     = 1 << 2,
+        CONF_FILES_BASENAME      = 1 << 3,
+        CONF_FILES_FILTER_MASKED = 1 << 4,
+};
+
+int conf_files_list(char ***ret, const char *suffix, const char *root, unsigned flags, const char *dir, ...) _sentinel_;
+int conf_files_list_strv(char ***ret, const char *suffix, const char *root, unsigned flags, const char* const* dirs);
+int conf_files_list_nulstr(char ***ret, const char *suffix, const char *root, unsigned flags, const char *dirs);
+int conf_files_insert(char ***strv, const char *root, char **dirs, const char *path);
+int conf_files_list_with_replacement(
+                const char *root,
+                char **config_dirs,
+                const char *replacement,
+                char ***files,
+                char **replace_file);
diff --git a/src/basic/copy.c b/src/basic/copy.c
new file mode 100644
index 0000000..46e02a3
--- /dev/null
+++ b/src/basic/copy.c
@@ -0,0 +1,936 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/sendfile.h>
+#include <sys/stat.h>
+#include <sys/xattr.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "btrfs-util.h"
+#include "chattr-util.h"
+#include "copy.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "mountpoint-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "tmpfile-util.h"
+#include "umask-util.h"
+#include "user-util.h"
+#include "xattr-util.h"
+
+#define COPY_BUFFER_SIZE (16U*1024U)
+
+/* A safety net for descending recursively into file system trees to copy. On Linux PATH_MAX is 4096, which means the
+ * deepest valid path one can build is around 2048, which we hence use as a safety net here, to not spin endlessly in
+ * case of bind mount cycles and suchlike. */
+#define COPY_DEPTH_MAX 2048U
+
+static ssize_t try_copy_file_range(
+                int fd_in, loff_t *off_in,
+                int fd_out, loff_t *off_out,
+                size_t len,
+                unsigned flags) {
+
+        static int have = -1;
+        ssize_t r;
+
+        if (have == 0)
+                return -ENOSYS;
+
+        r = copy_file_range(fd_in, off_in, fd_out, off_out, len, flags);
+        if (have < 0)
+                have = r >= 0 || errno != ENOSYS;
+        if (r < 0)
+                return -errno;
+
+        return r;
+}
+
+enum {
+        FD_IS_NO_PIPE,
+        FD_IS_BLOCKING_PIPE,
+        FD_IS_NONBLOCKING_PIPE,
+};
+
+static int fd_is_nonblock_pipe(int fd) {
+        struct stat st;
+        int flags;
+
+        /* Checks whether the specified file descriptor refers to a pipe, and if so if O_NONBLOCK is set. */
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (!S_ISFIFO(st.st_mode))
+                return FD_IS_NO_PIPE;
+
+        flags = fcntl(fd, F_GETFL);
+        if (flags < 0)
+                return -errno;
+
+        return FLAGS_SET(flags, O_NONBLOCK) ? FD_IS_NONBLOCKING_PIPE : FD_IS_BLOCKING_PIPE;
+}
+
+int copy_bytes_full(
+                int fdf, int fdt,
+                uint64_t max_bytes,
+                CopyFlags copy_flags,
+                void **ret_remains,
+                size_t *ret_remains_size,
+                copy_progress_bytes_t progress,
+                void *userdata) {
+
+        bool try_cfr = true, try_sendfile = true, try_splice = true;
+        int r, nonblock_pipe = -1;
+        size_t m = SSIZE_MAX; /* that is the maximum that sendfile and c_f_r accept */
+
+        assert(fdf >= 0);
+        assert(fdt >= 0);
+
+        /* Tries to copy bytes from the file descriptor 'fdf' to 'fdt' in the smartest possible way. Copies a maximum
+         * of 'max_bytes', which may be specified as UINT64_MAX, in which no maximum is applied. Returns negative on
+         * error, zero if EOF is hit before the bytes limit is hit and positive otherwise. If the copy fails for some
+         * reason but we read but didn't yet write some data an ret_remains/ret_remains_size is not NULL, then it will
+         * be initialized with an allocated buffer containing this "remaining" data. Note that these two parameters are
+         * initialized with a valid buffer only on failure and only if there's actually data already read. Otherwise
+         * these parameters if non-NULL are set to NULL. */
+
+        if (ret_remains)
+                *ret_remains = NULL;
+        if (ret_remains_size)
+                *ret_remains_size = 0;
+
+        /* Try btrfs reflinks first. This only works on regular, seekable files, hence let's check the file offsets of
+         * source and destination first. */
+        if ((copy_flags & COPY_REFLINK)) {
+                off_t foffset;
+
+                foffset = lseek(fdf, 0, SEEK_CUR);
+                if (foffset >= 0) {
+                        off_t toffset;
+
+                        toffset = lseek(fdt, 0, SEEK_CUR);
+                        if (toffset >= 0) {
+
+                                if (foffset == 0 && toffset == 0 && max_bytes == UINT64_MAX)
+                                        r = btrfs_reflink(fdf, fdt); /* full file reflink */
+                                else
+                                        r = btrfs_clone_range(fdf, foffset, fdt, toffset, max_bytes == UINT64_MAX ? 0 : max_bytes); /* partial reflink */
+                                if (r >= 0) {
+                                        off_t t;
+
+                                        /* This worked, yay! Now — to be fully correct — let's adjust the file pointers */
+                                        if (max_bytes == UINT64_MAX) {
+
+                                                /* We cloned to the end of the source file, let's position the read
+                                                 * pointer there, and query it at the same time. */
+                                                t = lseek(fdf, 0, SEEK_END);
+                                                if (t < 0)
+                                                        return -errno;
+                                                if (t < foffset)
+                                                        return -ESPIPE;
+
+                                                /* Let's adjust the destination file write pointer by the same number
+                                                 * of bytes. */
+                                                t = lseek(fdt, toffset + (t - foffset), SEEK_SET);
+                                                if (t < 0)
+                                                        return -errno;
+
+                                                return 0; /* we copied the whole thing, hence hit EOF, return 0 */
+                                        } else {
+                                                t = lseek(fdf, foffset + max_bytes, SEEK_SET);
+                                                if (t < 0)
+                                                        return -errno;
+
+                                                t = lseek(fdt, toffset + max_bytes, SEEK_SET);
+                                                if (t < 0)
+                                                        return -errno;
+
+                                                return 1; /* we copied only some number of bytes, which worked, but this means we didn't hit EOF, return 1 */
+                                        }
+                                }
+                        }
+                }
+        }
+
+        for (;;) {
+                ssize_t n;
+
+                if (max_bytes <= 0)
+                        return 1; /* return > 0 if we hit the max_bytes limit */
+
+                if (max_bytes != UINT64_MAX && m > max_bytes)
+                        m = max_bytes;
+
+                /* First try copy_file_range(), unless we already tried */
+                if (try_cfr) {
+                        n = try_copy_file_range(fdf, NULL, fdt, NULL, m, 0u);
+                        if (n < 0) {
+                                if (!IN_SET(n, -EINVAL, -ENOSYS, -EXDEV, -EBADF))
+                                        return n;
+
+                                try_cfr = false;
+                                /* use fallback below */
+                        } else if (n == 0) /* EOF */
+                                break;
+                        else
+                                /* Success! */
+                                goto next;
+                }
+
+                /* First try sendfile(), unless we already tried */
+                if (try_sendfile) {
+                        n = sendfile(fdt, fdf, NULL, m);
+                        if (n < 0) {
+                                if (!IN_SET(errno, EINVAL, ENOSYS))
+                                        return -errno;
+
+                                try_sendfile = false;
+                                /* use fallback below */
+                        } else if (n == 0) /* EOF */
+                                break;
+                        else
+                                /* Success! */
+                                goto next;
+                }
+
+                /* Then try splice, unless we already tried. */
+                if (try_splice) {
+
+                        /* splice()'s asynchronous I/O support is a bit weird. When it encounters a pipe file
+                         * descriptor, then it will ignore its O_NONBLOCK flag and instead only honour the
+                         * SPLICE_F_NONBLOCK flag specified in its flag parameter. Let's hide this behaviour here, and
+                         * check if either of the specified fds are a pipe, and if so, let's pass the flag
+                         * automatically, depending on O_NONBLOCK being set.
+                         *
+                         * Here's a twist though: when we use it to move data between two pipes of which one has
+                         * O_NONBLOCK set and the other has not, then we have no individual control over O_NONBLOCK
+                         * behaviour. Hence in that case we can't use splice() and still guarantee systematic
+                         * O_NONBLOCK behaviour, hence don't. */
+
+                        if (nonblock_pipe < 0) {
+                                int a, b;
+
+                                /* Check if either of these fds is a pipe, and if so non-blocking or not */
+                                a = fd_is_nonblock_pipe(fdf);
+                                if (a < 0)
+                                        return a;
+
+                                b = fd_is_nonblock_pipe(fdt);
+                                if (b < 0)
+                                        return b;
+
+                                if ((a == FD_IS_NO_PIPE && b == FD_IS_NO_PIPE) ||
+                                    (a == FD_IS_BLOCKING_PIPE && b == FD_IS_NONBLOCKING_PIPE) ||
+                                    (a == FD_IS_NONBLOCKING_PIPE && b == FD_IS_BLOCKING_PIPE))
+
+                                        /* splice() only works if one of the fds is a pipe. If neither is, let's skip
+                                         * this step right-away. As mentioned above, if one of the two fds refers to a
+                                         * blocking pipe and the other to a non-blocking pipe, we can't use splice()
+                                         * either, hence don't try either. This hence means we can only use splice() if
+                                         * either only one of the two fds is a pipe, or if both are pipes with the same
+                                         * nonblocking flag setting. */
+
+                                        try_splice = false;
+                                else
+                                        nonblock_pipe = a == FD_IS_NONBLOCKING_PIPE || b == FD_IS_NONBLOCKING_PIPE;
+                        }
+                }
+
+                if (try_splice) {
+                        n = splice(fdf, NULL, fdt, NULL, m, nonblock_pipe ? SPLICE_F_NONBLOCK : 0);
+                        if (n < 0) {
+                                if (!IN_SET(errno, EINVAL, ENOSYS))
+                                        return -errno;
+
+                                try_splice = false;
+                                /* use fallback below */
+                        } else if (n == 0) /* EOF */
+                                break;
+                        else
+                                /* Success! */
+                                goto next;
+                }
+
+                /* As a fallback just copy bits by hand */
+                {
+                        uint8_t buf[MIN(m, COPY_BUFFER_SIZE)], *p = buf;
+                        ssize_t z;
+
+                        n = read(fdf, buf, sizeof buf);
+                        if (n < 0)
+                                return -errno;
+                        if (n == 0) /* EOF */
+                                break;
+
+                        z = (size_t) n;
+                        do {
+                                ssize_t k;
+
+                                k = write(fdt, p, z);
+                                if (k < 0) {
+                                        r = -errno;
+
+                                        if (ret_remains) {
+                                                void *copy;
+
+                                                copy = memdup(p, z);
+                                                if (!copy)
+                                                        return -ENOMEM;
+
+                                                *ret_remains = copy;
+                                        }
+
+                                        if (ret_remains_size)
+                                                *ret_remains_size = z;
+
+                                        return r;
+                                }
+
+                                assert(k <= z);
+                                z -= k;
+                                p += k;
+                        } while (z > 0);
+                }
+
+        next:
+                if (progress) {
+                        r = progress(n, userdata);
+                        if (r < 0)
+                                return r;
+                }
+
+                if (max_bytes != (uint64_t) -1) {
+                        assert(max_bytes >= (uint64_t) n);
+                        max_bytes -= n;
+                }
+
+                /* sendfile accepts at most SSIZE_MAX-offset bytes to copy,
+                 * so reduce our maximum by the amount we already copied,
+                 * but don't go below our copy buffer size, unless we are
+                 * close the limit of bytes we are allowed to copy. */
+                m = MAX(MIN(COPY_BUFFER_SIZE, max_bytes), m - n);
+        }
+
+        return 0; /* return 0 if we hit EOF earlier than the size limit */
+}
+
+static int fd_copy_symlink(
+                int df,
+                const char *from,
+                const struct stat *st,
+                int dt,
+                const char *to,
+                uid_t override_uid,
+                gid_t override_gid,
+                CopyFlags copy_flags) {
+
+        _cleanup_free_ char *target = NULL;
+        int r;
+
+        assert(from);
+        assert(st);
+        assert(to);
+
+        r = readlinkat_malloc(df, from, &target);
+        if (r < 0)
+                return r;
+
+        if (symlinkat(target, dt, to) < 0)
+                return -errno;
+
+        if (fchownat(dt, to,
+                     uid_is_valid(override_uid) ? override_uid : st->st_uid,
+                     gid_is_valid(override_gid) ? override_gid : st->st_gid,
+                     AT_SYMLINK_NOFOLLOW) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int fd_copy_regular(
+                int df,
+                const char *from,
+                const struct stat *st,
+                int dt,
+                const char *to,
+                uid_t override_uid,
+                gid_t override_gid,
+                CopyFlags copy_flags,
+                copy_progress_bytes_t progress,
+                void *userdata) {
+
+        _cleanup_close_ int fdf = -1, fdt = -1;
+        struct timespec ts[2];
+        int r, q;
+
+        assert(from);
+        assert(st);
+        assert(to);
+
+        fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fdf < 0)
+                return -errno;
+
+        fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
+        if (fdt < 0)
+                return -errno;
+
+        r = copy_bytes_full(fdf, fdt, (uint64_t) -1, copy_flags, NULL, NULL, progress, userdata);
+        if (r < 0) {
+                (void) unlinkat(dt, to, 0);
+                return r;
+        }
+
+        if (fchown(fdt,
+                   uid_is_valid(override_uid) ? override_uid : st->st_uid,
+                   gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0)
+                r = -errno;
+
+        if (fchmod(fdt, st->st_mode & 07777) < 0)
+                r = -errno;
+
+        ts[0] = st->st_atim;
+        ts[1] = st->st_mtim;
+        (void) futimens(fdt, ts);
+        (void) copy_xattr(fdf, fdt);
+
+        q = close(fdt);
+        fdt = -1;
+
+        if (q < 0) {
+                r = -errno;
+                (void) unlinkat(dt, to, 0);
+        }
+
+        return r;
+}
+
+static int fd_copy_fifo(
+                int df,
+                const char *from,
+                const struct stat *st,
+                int dt,
+                const char *to,
+                uid_t override_uid,
+                gid_t override_gid,
+                CopyFlags copy_flags) {
+        int r;
+
+        assert(from);
+        assert(st);
+        assert(to);
+
+        r = mkfifoat(dt, to, st->st_mode & 07777);
+        if (r < 0)
+                return -errno;
+
+        if (fchownat(dt, to,
+                     uid_is_valid(override_uid) ? override_uid : st->st_uid,
+                     gid_is_valid(override_gid) ? override_gid : st->st_gid,
+                     AT_SYMLINK_NOFOLLOW) < 0)
+                r = -errno;
+
+        if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
+                r = -errno;
+
+        return r;
+}
+
+static int fd_copy_node(
+                int df,
+                const char *from,
+                const struct stat *st,
+                int dt,
+                const char *to,
+                uid_t override_uid,
+                gid_t override_gid,
+                CopyFlags copy_flags) {
+        int r;
+
+        assert(from);
+        assert(st);
+        assert(to);
+
+        r = mknodat(dt, to, st->st_mode, st->st_rdev);
+        if (r < 0)
+                return -errno;
+
+        if (fchownat(dt, to,
+                     uid_is_valid(override_uid) ? override_uid : st->st_uid,
+                     gid_is_valid(override_gid) ? override_gid : st->st_gid,
+                     AT_SYMLINK_NOFOLLOW) < 0)
+                r = -errno;
+
+        if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
+                r = -errno;
+
+        return r;
+}
+
+static int fd_copy_directory(
+                int df,
+                const char *from,
+                const struct stat *st,
+                int dt,
+                const char *to,
+                dev_t original_device,
+                unsigned depth_left,
+                uid_t override_uid,
+                gid_t override_gid,
+                CopyFlags copy_flags,
+                const char *display_path,
+                copy_progress_path_t progress_path,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        _cleanup_close_ int fdf = -1, fdt = -1;
+        _cleanup_closedir_ DIR *d = NULL;
+        struct dirent *de;
+        bool exists, created;
+        int r;
+
+        assert(st);
+        assert(to);
+
+        if (depth_left == 0)
+                return -ENAMETOOLONG;
+
+        if (from)
+                fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        else
+                fdf = fcntl(df, F_DUPFD_CLOEXEC, 3);
+        if (fdf < 0)
+                return -errno;
+
+        d = fdopendir(fdf);
+        if (!d)
+                return -errno;
+        fdf = -1;
+
+        exists = false;
+        if (copy_flags & COPY_MERGE_EMPTY) {
+                r = dir_is_empty_at(dt, to);
+                if (r < 0 && r != -ENOENT)
+                        return r;
+                else if (r == 1)
+                        exists = true;
+        }
+
+        if (exists)
+                created = false;
+        else {
+                r = mkdirat(dt, to, st->st_mode & 07777);
+                if (r >= 0)
+                        created = true;
+                else if (errno == EEXIST && (copy_flags & COPY_MERGE))
+                        created = false;
+                else
+                        return -errno;
+        }
+
+        fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fdt < 0)
+                return -errno;
+
+        r = 0;
+
+        FOREACH_DIRENT_ALL(de, d, return -errno) {
+                const char *child_display_path = NULL;
+                _cleanup_free_ char *dp = NULL;
+                struct stat buf;
+                int q;
+
+                if (dot_or_dot_dot(de->d_name))
+                        continue;
+
+                if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
+                        r = -errno;
+                        continue;
+                }
+
+                if (progress_path) {
+                        if (display_path)
+                                child_display_path = dp = strjoin(display_path, "/", de->d_name);
+                        else
+                                child_display_path = de->d_name;
+
+                        r = progress_path(child_display_path, &buf, userdata);
+                        if (r < 0)
+                                return r;
+                }
+
+                if (S_ISDIR(buf.st_mode)) {
+                        /*
+                         * Don't descend into directories on other file systems, if this is requested. We do a simple
+                         * .st_dev check here, which basically comes for free. Note that we do this check only on
+                         * directories, not other kind of file system objects, for two reason:
+                         *
+                         * • The kernel's overlayfs pseudo file system that overlays multiple real file systems
+                         *   propagates the .st_dev field of the file system a file originates from all the way up
+                         *   through the stack to stat(). It doesn't do that for directories however. This means that
+                         *   comparing .st_dev on non-directories suggests that they all are mount points. To avoid
+                         *   confusion we hence avoid relying on this check for regular files.
+                         *
+                         * • The main reason we do this check at all is to protect ourselves from bind mount cycles,
+                         *   where we really want to avoid descending down in all eternity. However the .st_dev check
+                         *   is usually not sufficient for this protection anyway, as bind mount cycles from the same
+                         *   file system onto itself can't be detected that way. (Note we also do a recursion depth
+                         *   check, which is probably the better protection in this regard, which is why
+                         *   COPY_SAME_MOUNT is optional).
+                         */
+
+                        if (FLAGS_SET(copy_flags, COPY_SAME_MOUNT)) {
+                                if (buf.st_dev != original_device)
+                                        continue;
+
+                                r = fd_is_mount_point(dirfd(d), de->d_name, 0);
+                                if (r < 0)
+                                        return r;
+                                if (r > 0)
+                                        continue;
+                        }
+
+                        q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, depth_left-1, override_uid, override_gid, copy_flags, child_display_path, progress_path, progress_bytes, userdata);
+                } else if (S_ISREG(buf.st_mode))
+                        q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags, progress_bytes, userdata);
+                else if (S_ISLNK(buf.st_mode))
+                        q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
+                else if (S_ISFIFO(buf.st_mode))
+                        q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
+                else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode) || S_ISSOCK(buf.st_mode))
+                        q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
+                else
+                        q = -EOPNOTSUPP;
+
+                if (q == -EEXIST && (copy_flags & COPY_MERGE))
+                        q = 0;
+
+                if (q < 0)
+                        r = q;
+        }
+
+        if (created) {
+                struct timespec ut[2] = {
+                        st->st_atim,
+                        st->st_mtim
+                };
+
+                if (fchown(fdt,
+                           uid_is_valid(override_uid) ? override_uid : st->st_uid,
+                           gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0)
+                        r = -errno;
+
+                if (fchmod(fdt, st->st_mode & 07777) < 0)
+                        r = -errno;
+
+                (void) copy_xattr(dirfd(d), fdt);
+                (void) futimens(fdt, ut);
+        }
+
+        return r;
+}
+
+int copy_tree_at_full(
+                int fdf,
+                const char *from,
+                int fdt,
+                const char *to,
+                uid_t override_uid,
+                gid_t override_gid,
+                CopyFlags copy_flags,
+                copy_progress_path_t progress_path,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        struct stat st;
+
+        assert(from);
+        assert(to);
+
+        if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0)
+                return -errno;
+
+        if (S_ISREG(st.st_mode))
+                return fd_copy_regular(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags, progress_bytes, userdata);
+        else if (S_ISDIR(st.st_mode))
+                return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, COPY_DEPTH_MAX, override_uid, override_gid, copy_flags, NULL, progress_path, progress_bytes, userdata);
+        else if (S_ISLNK(st.st_mode))
+                return fd_copy_symlink(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
+        else if (S_ISFIFO(st.st_mode))
+                return fd_copy_fifo(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
+        else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode) || S_ISSOCK(st.st_mode))
+                return fd_copy_node(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
+        else
+                return -EOPNOTSUPP;
+}
+
+int copy_directory_fd_full(
+                int dirfd,
+                const char *to,
+                CopyFlags copy_flags,
+                copy_progress_path_t progress_path,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        struct stat st;
+
+        assert(dirfd >= 0);
+        assert(to);
+
+        if (fstat(dirfd, &st) < 0)
+                return -errno;
+
+        if (!S_ISDIR(st.st_mode))
+                return -ENOTDIR;
+
+        return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, COPY_DEPTH_MAX, UID_INVALID, GID_INVALID, copy_flags, NULL, progress_path, progress_bytes, userdata);
+}
+
+int copy_directory_full(
+                const char *from,
+                const char *to,
+                CopyFlags copy_flags,
+                copy_progress_path_t progress_path,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        struct stat st;
+
+        assert(from);
+        assert(to);
+
+        if (lstat(from, &st) < 0)
+                return -errno;
+
+        if (!S_ISDIR(st.st_mode))
+                return -ENOTDIR;
+
+        return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, COPY_DEPTH_MAX, UID_INVALID, GID_INVALID, copy_flags, NULL, progress_path, progress_bytes, userdata);
+}
+
+int copy_file_fd_full(
+                const char *from,
+                int fdt,
+                CopyFlags copy_flags,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        _cleanup_close_ int fdf = -1;
+        int r;
+
+        assert(from);
+        assert(fdt >= 0);
+
+        fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+        if (fdf < 0)
+                return -errno;
+
+        r = copy_bytes_full(fdf, fdt, (uint64_t) -1, copy_flags, NULL, NULL, progress_bytes, userdata);
+
+        (void) copy_times(fdf, fdt);
+        (void) copy_xattr(fdf, fdt);
+
+        return r;
+}
+
+int copy_file_full(
+                const char *from,
+                const char *to,
+                int flags,
+                mode_t mode,
+                unsigned chattr_flags,
+                CopyFlags copy_flags,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        int fdt = -1, r;
+
+        assert(from);
+        assert(to);
+
+        RUN_WITH_UMASK(0000) {
+                fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
+                if (fdt < 0)
+                        return -errno;
+        }
+
+        if (chattr_flags != 0)
+                (void) chattr_fd(fdt, chattr_flags, (unsigned) -1, NULL);
+
+        r = copy_file_fd_full(from, fdt, copy_flags, progress_bytes, userdata);
+        if (r < 0) {
+                close(fdt);
+                (void) unlink(to);
+                return r;
+        }
+
+        if (close(fdt) < 0) {
+                unlink_noerrno(to);
+                return -errno;
+        }
+
+        return 0;
+}
+
+int copy_file_atomic_full(
+                const char *from,
+                const char *to,
+                mode_t mode,
+                unsigned chattr_flags,
+                CopyFlags copy_flags,
+                copy_progress_bytes_t progress_bytes,
+                void *userdata) {
+
+        _cleanup_(unlink_and_freep) char *t = NULL;
+        _cleanup_close_ int fdt = -1;
+        int r;
+
+        assert(from);
+        assert(to);
+
+        /* We try to use O_TMPFILE here to create the file if we can. Note that that only works if COPY_REPLACE is not
+         * set though as we need to use linkat() for linking the O_TMPFILE file into the file system but that system
+         * call can't replace existing files. Hence, if COPY_REPLACE is set we create a temporary name in the file
+         * system right-away and unconditionally which we then can renameat() to the right name after we completed
+         * writing it. */
+
+        if (copy_flags & COPY_REPLACE) {
+                r = tempfn_random(to, NULL, &t);
+                if (r < 0)
+                        return r;
+
+                fdt = open(t, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|O_WRONLY|O_CLOEXEC, 0600);
+                if (fdt < 0) {
+                        t = mfree(t);
+                        return -errno;
+                }
+        } else {
+                fdt = open_tmpfile_linkable(to, O_WRONLY|O_CLOEXEC, &t);
+                if (fdt < 0)
+                        return fdt;
+        }
+
+        if (chattr_flags != 0)
+                (void) chattr_fd(fdt, chattr_flags, (unsigned) -1, NULL);
+
+        r = copy_file_fd_full(from, fdt, copy_flags, progress_bytes, userdata);
+        if (r < 0)
+                return r;
+
+        if (fchmod(fdt, mode) < 0)
+                return -errno;
+
+        if (copy_flags & COPY_REPLACE) {
+                if (renameat(AT_FDCWD, t, AT_FDCWD, to) < 0)
+                        return -errno;
+        } else {
+                r = link_tmpfile(fdt, t, to);
+                if (r < 0)
+                        return r;
+        }
+
+        t = mfree(t);
+        return 0;
+}
+
+int copy_times(int fdf, int fdt) {
+        struct timespec ut[2];
+        struct stat st;
+        usec_t crtime = 0;
+
+        assert(fdf >= 0);
+        assert(fdt >= 0);
+
+        if (fstat(fdf, &st) < 0)
+                return -errno;
+
+        ut[0] = st.st_atim;
+        ut[1] = st.st_mtim;
+
+        if (futimens(fdt, ut) < 0)
+                return -errno;
+
+        if (fd_getcrtime(fdf, &crtime) >= 0)
+                (void) fd_setcrtime(fdt, crtime);
+
+        return 0;
+}
+
+int copy_xattr(int fdf, int fdt) {
+        _cleanup_free_ char *bufa = NULL, *bufb = NULL;
+        size_t sza = 100, szb = 100;
+        ssize_t n;
+        int ret = 0;
+        const char *p;
+
+        for (;;) {
+                bufa = malloc(sza);
+                if (!bufa)
+                        return -ENOMEM;
+
+                n = flistxattr(fdf, bufa, sza);
+                if (n == 0)
+                        return 0;
+                if (n > 0)
+                        break;
+                if (errno != ERANGE)
+                        return -errno;
+
+                sza *= 2;
+
+                bufa = mfree(bufa);
+        }
+
+        p = bufa;
+        while (n > 0) {
+                size_t l;
+
+                l = strlen(p);
+                assert(l < (size_t) n);
+
+                if (startswith(p, "user.")) {
+                        ssize_t m;
+
+                        if (!bufb) {
+                                bufb = malloc(szb);
+                                if (!bufb)
+                                        return -ENOMEM;
+                        }
+
+                        m = fgetxattr(fdf, p, bufb, szb);
+                        if (m < 0) {
+                                if (errno == ERANGE) {
+                                        szb *= 2;
+                                        bufb = mfree(bufb);
+                                        continue;
+                                }
+
+                                return -errno;
+                        }
+
+                        if (fsetxattr(fdt, p, bufb, m, 0) < 0)
+                                ret = -errno;
+                }
+
+                p += l + 1;
+                n -= l + 1;
+        }
+
+        return ret;
+}
diff --git a/src/basic/copy.h b/src/basic/copy.h
new file mode 100644
index 0000000..f677021
--- /dev/null
+++ b/src/basic/copy.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+typedef enum CopyFlags {
+        COPY_REFLINK     = 1 << 0, /* Try to reflink */
+        COPY_MERGE       = 1 << 1, /* Merge existing trees with our new one to copy */
+        COPY_REPLACE     = 1 << 2, /* Replace an existing file if there's one */
+        COPY_SAME_MOUNT  = 1 << 3, /* Don't descend recursively into other file systems, across mount point boundaries */
+        COPY_MERGE_EMPTY = 1 << 4, /* Merge an existing, empty directory with our new tree to copy */
+} CopyFlags;
+
+typedef int (*copy_progress_bytes_t)(uint64_t n_bytes, void *userdata);
+typedef int (*copy_progress_path_t)(const char *path, const struct stat *st, void *userdata);
+
+int copy_file_fd_full(const char *from, int to, CopyFlags copy_flags, copy_progress_bytes_t progress, void *userdata);
+static inline int copy_file_fd(const char *from, int to, CopyFlags copy_flags) {
+        return copy_file_fd_full(from, to, copy_flags, NULL, NULL);
+}
+
+int copy_file_full(const char *from, const char *to, int open_flags, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags, copy_progress_bytes_t progress, void *userdata);
+static inline int copy_file(const char *from, const char *to, int open_flags, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags) {
+        return copy_file_full(from, to, open_flags, mode, chattr_flags, copy_flags, NULL, NULL);
+}
+
+int copy_file_atomic_full(const char *from, const char *to, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags, copy_progress_bytes_t progress, void *userdata);
+static inline int copy_file_atomic(const char *from, const char *to, mode_t mode, unsigned chattr_flags, CopyFlags copy_flags) {
+        return copy_file_atomic_full(from, to, mode, chattr_flags, copy_flags, NULL, NULL);
+}
+
+int copy_tree_at_full(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata);
+static inline int copy_tree_at(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags) {
+        return copy_tree_at_full(fdf, from, fdt, to, override_uid, override_gid, copy_flags, NULL, NULL, NULL);
+}
+static inline int copy_tree(const char *from, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags) {
+        return copy_tree_at_full(AT_FDCWD, from, AT_FDCWD, to, override_uid, override_gid, copy_flags, NULL, NULL, NULL);
+}
+
+int copy_directory_fd_full(int dirfd, const char *to, CopyFlags copy_flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata);
+static inline int copy_directory_fd(int dirfd, const char *to, CopyFlags copy_flags) {
+        return copy_directory_fd_full(dirfd, to, copy_flags, NULL, NULL, NULL);
+}
+
+int copy_directory_full(const char *from, const char *to, CopyFlags copy_flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata);
+static inline int copy_directory(const char *from, const char *to, CopyFlags copy_flags) {
+        return copy_directory_full(from, to, copy_flags, NULL, NULL, NULL);
+}
+
+int copy_bytes_full(int fdf, int fdt, uint64_t max_bytes, CopyFlags copy_flags, void **ret_remains, size_t *ret_remains_size, copy_progress_bytes_t progress, void *userdata);
+static inline int copy_bytes(int fdf, int fdt, uint64_t max_bytes, CopyFlags copy_flags) {
+        return copy_bytes_full(fdf, fdt, max_bytes, copy_flags, NULL, NULL, NULL, NULL);
+}
+
+int copy_times(int fdf, int fdt);
+int copy_xattr(int fdf, int fdt);
diff --git a/src/basic/def.h b/src/basic/def.h
new file mode 100644
index 0000000..5be018d
--- /dev/null
+++ b/src/basic/def.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "util.h"
+
+#define DEFAULT_TIMEOUT_USEC (90*USEC_PER_SEC)
+#define DEFAULT_RESTART_USEC (100*USEC_PER_MSEC)
+#define DEFAULT_CONFIRM_USEC (30*USEC_PER_SEC)
+
+#define DEFAULT_START_LIMIT_INTERVAL (10*USEC_PER_SEC)
+#define DEFAULT_START_LIMIT_BURST 5
+
+/* The default time after which exit-on-idle services exit. This
+ * should be kept lower than the watchdog timeout, because otherwise
+ * the watchdog pings will keep the loop busy. */
+#define DEFAULT_EXIT_USEC (30*USEC_PER_SEC)
+
+/* The default value for the net.unix.max_dgram_qlen sysctl */
+#define DEFAULT_UNIX_MAX_DGRAM_QLEN 512UL
+
+#define SIGNALS_CRASH_HANDLER SIGSEGV,SIGILL,SIGFPE,SIGBUS,SIGQUIT,SIGABRT
+#define SIGNALS_IGNORE SIGPIPE
+
+#if HAVE_SPLIT_USR
+#define KBD_KEYMAP_DIRS                         \
+        "/usr/share/keymaps/\0"                 \
+        "/usr/share/kbd/keymaps/\0"             \
+        "/usr/lib/kbd/keymaps/\0"               \
+        "/lib/kbd/keymaps/\0"
+#else
+#define KBD_KEYMAP_DIRS                         \
+        "/usr/share/keymaps/\0"                 \
+        "/usr/share/kbd/keymaps/\0"             \
+        "/usr/lib/kbd/keymaps/\0"
+#endif
+
+/* Note that we use the new /run prefix here (instead of /var/run) since we require them to be aliases and that way we
+ * become independent of /var being mounted */
+#define DEFAULT_SYSTEM_BUS_ADDRESS "unix:path=/run/dbus/system_bus_socket"
+#define DEFAULT_USER_BUS_ADDRESS_FMT "unix:path=%s/bus"
+
+#define PLYMOUTH_SOCKET {                                       \
+                .un.sun_family = AF_UNIX,                       \
+                .un.sun_path = "\0/org/freedesktop/plymouthd",  \
+        }
+
+#define NOTIFY_FD_MAX 768
+#define NOTIFY_BUFFER_MAX PIPE_BUF
+
+#if HAVE_SPLIT_USR
+#  define _CONF_PATHS_SPLIT_USR_NULSTR(n) "/lib/" n "\0"
+#  define _CONF_PATHS_SPLIT_USR(n) , "/lib/" n
+#else
+#  define _CONF_PATHS_SPLIT_USR_NULSTR(n)
+#  define _CONF_PATHS_SPLIT_USR(n)
+#endif
+
+/* Return a nulstr for a standard cascade of configuration paths,
+ * suitable to pass to conf_files_list_nulstr() or config_parse_many_nulstr()
+ * to implement drop-in directories for extending configuration
+ * files. */
+#define CONF_PATHS_NULSTR(n)                    \
+        "/etc/" n "\0"                          \
+        "/run/" n "\0"                          \
+        "/usr/local/lib/" n "\0"                \
+        "/usr/lib/" n "\0"                      \
+        _CONF_PATHS_SPLIT_USR_NULSTR(n)
+
+#define CONF_PATHS_STRV(n)                      \
+        STRV_MAKE(                              \
+                "/etc/" n,                      \
+                "/run/" n,                      \
+                "/usr/local/lib/" n,            \
+                "/usr/lib/" n                   \
+                _CONF_PATHS_SPLIT_USR(n))
+
+#define HIGH_RLIMIT_MEMLOCK (1024ULL*1024ULL*64ULL)
diff --git a/src/basic/device-nodes.c b/src/basic/device-nodes.c
new file mode 100644
index 0000000..5fcdf24
--- /dev/null
+++ b/src/basic/device-nodes.c
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "device-nodes.h"
+#include "utf8.h"
+
+int whitelisted_char_for_devnode(char c, const char *white) {
+
+        if ((c >= '0' && c <= '9') ||
+            (c >= 'A' && c <= 'Z') ||
+            (c >= 'a' && c <= 'z') ||
+            strchr("#+-.:=@_", c) != NULL ||
+            (white != NULL && strchr(white, c) != NULL))
+                return 1;
+
+        return 0;
+}
+
+int encode_devnode_name(const char *str, char *str_enc, size_t len) {
+        size_t i, j;
+
+        if (!str || !str_enc)
+                return -EINVAL;
+
+        for (i = 0, j = 0; str[i] != '\0'; i++) {
+                int seqlen;
+
+                seqlen = utf8_encoded_valid_unichar(&str[i]);
+                if (seqlen > 1) {
+
+                        if (len-j < (size_t)seqlen)
+                                return -EINVAL;
+
+                        memcpy(&str_enc[j], &str[i], seqlen);
+                        j += seqlen;
+                        i += (seqlen-1);
+
+                } else if (str[i] == '\\' || !whitelisted_char_for_devnode(str[i], NULL)) {
+
+                        if (len-j < 4)
+                                return -EINVAL;
+
+                        sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
+                        j += 4;
+
+                } else {
+                        if (len-j < 1)
+                                return -EINVAL;
+
+                        str_enc[j] = str[i];
+                        j++;
+                }
+        }
+
+        if (len-j < 1)
+                return -EINVAL;
+
+        str_enc[j] = '\0';
+        return 0;
+}
diff --git a/src/basic/device-nodes.h b/src/basic/device-nodes.h
new file mode 100644
index 0000000..3840e6d
--- /dev/null
+++ b/src/basic/device-nodes.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stddef.h>
+#include <sys/types.h>
+
+#include "macro.h"
+#include "stdio-util.h"
+
+int encode_devnode_name(const char *str, char *str_enc, size_t len);
+int whitelisted_char_for_devnode(char c, const char *additional);
+
+#define DEV_NUM_PATH_MAX                                                \
+        (STRLEN("/dev/block/") + DECIMAL_STR_MAX(dev_t) + 1 + DECIMAL_STR_MAX(dev_t))
+#define xsprintf_dev_num_path(buf, type, devno)                         \
+        xsprintf(buf, "/dev/%s/%u:%u", type, major(devno), minor(devno))
diff --git a/src/basic/dirent-util.c b/src/basic/dirent-util.c
new file mode 100644
index 0000000..d1d2c0e
--- /dev/null
+++ b/src/basic/dirent-util.c
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <fcntl.h>
+#include <sys/stat.h>
+
+#include "dirent-util.h"
+#include "path-util.h"
+#include "string-util.h"
+
+int dirent_ensure_type(DIR *d, struct dirent *de) {
+        struct stat st;
+
+        assert(d);
+        assert(de);
+
+        if (de->d_type != DT_UNKNOWN)
+                return 0;
+
+        if (fstatat(dirfd(d), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0)
+                return -errno;
+
+        de->d_type =
+                S_ISREG(st.st_mode)  ? DT_REG  :
+                S_ISDIR(st.st_mode)  ? DT_DIR  :
+                S_ISLNK(st.st_mode)  ? DT_LNK  :
+                S_ISFIFO(st.st_mode) ? DT_FIFO :
+                S_ISSOCK(st.st_mode) ? DT_SOCK :
+                S_ISCHR(st.st_mode)  ? DT_CHR  :
+                S_ISBLK(st.st_mode)  ? DT_BLK  :
+                                       DT_UNKNOWN;
+
+        return 0;
+}
+
+bool dirent_is_file(const struct dirent *de) {
+        assert(de);
+
+        if (!IN_SET(de->d_type, DT_REG, DT_LNK, DT_UNKNOWN))
+                return false;
+
+        if (hidden_or_backup_file(de->d_name))
+                return false;
+
+        return true;
+}
+
+bool dirent_is_file_with_suffix(const struct dirent *de, const char *suffix) {
+        assert(de);
+
+        if (!IN_SET(de->d_type, DT_REG, DT_LNK, DT_UNKNOWN))
+                return false;
+
+        if (de->d_name[0] == '.')
+                return false;
+
+        if (!suffix)
+                return true;
+
+        return endswith(de->d_name, suffix);
+}
+
+struct dirent* readdir_no_dot(DIR *dirp) {
+        struct dirent* d;
+
+        for (;;) {
+                d = readdir(dirp);
+                if (d && dot_or_dot_dot(d->d_name))
+                        continue;
+                return d;
+        }
+}
diff --git a/src/basic/dirent-util.h b/src/basic/dirent-util.h
new file mode 100644
index 0000000..b1b8767
--- /dev/null
+++ b/src/basic/dirent-util.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <dirent.h>
+#include <errno.h>
+#include <stdbool.h>
+
+#include "macro.h"
+#include "path-util.h"
+
+int dirent_ensure_type(DIR *d, struct dirent *de);
+
+bool dirent_is_file(const struct dirent *de) _pure_;
+bool dirent_is_file_with_suffix(const struct dirent *de, const char *suffix) _pure_;
+
+struct dirent* readdir_no_dot(DIR *dirp);
+
+#define FOREACH_DIRENT(de, d, on_error)                                 \
+        for (errno = 0, de = readdir(d);; errno = 0, de = readdir(d))   \
+                if (!de) {                                              \
+                        if (errno > 0) {                                \
+                                on_error;                               \
+                        }                                               \
+                        break;                                          \
+                } else if (hidden_or_backup_file((de)->d_name))         \
+                        continue;                                       \
+                else
+
+#define FOREACH_DIRENT_ALL(de, d, on_error)                             \
+        for (errno = 0, de = readdir(d);; errno = 0, de = readdir(d))   \
+                if (!de) {                                              \
+                        if (errno > 0) {                                \
+                                on_error;                               \
+                        }                                               \
+                        break;                                          \
+                } else
diff --git a/src/basic/env-file.c b/src/basic/env-file.c
new file mode 100644
index 0000000..7f10f9a
--- /dev/null
+++ b/src/basic/env-file.c
@@ -0,0 +1,564 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdio_ext.h>
+
+#include "alloc-util.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "escape.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "tmpfile-util.h"
+#include "utf8.h"
+
+static int parse_env_file_internal(
+                FILE *f,
+                const char *fname,
+                int (*push) (const char *filename, unsigned line,
+                             const char *key, char *value, void *userdata, int *n_pushed),
+                void *userdata,
+                int *n_pushed) {
+
+        size_t key_alloc = 0, n_key = 0, value_alloc = 0, n_value = 0, last_value_whitespace = (size_t) -1, last_key_whitespace = (size_t) -1;
+        _cleanup_free_ char *contents = NULL, *key = NULL, *value = NULL;
+        unsigned line = 1;
+        char *p;
+        int r;
+
+        enum {
+                PRE_KEY,
+                KEY,
+                PRE_VALUE,
+                VALUE,
+                VALUE_ESCAPE,
+                SINGLE_QUOTE_VALUE,
+                DOUBLE_QUOTE_VALUE,
+                DOUBLE_QUOTE_VALUE_ESCAPE,
+                COMMENT,
+                COMMENT_ESCAPE
+        } state = PRE_KEY;
+
+        if (f)
+                r = read_full_stream(f, &contents, NULL);
+        else
+                r = read_full_file(fname, &contents, NULL);
+        if (r < 0)
+                return r;
+
+        for (p = contents; *p; p++) {
+                char c = *p;
+
+                switch (state) {
+
+                case PRE_KEY:
+                        if (strchr(COMMENTS, c))
+                                state = COMMENT;
+                        else if (!strchr(WHITESPACE, c)) {
+                                state = KEY;
+                                last_key_whitespace = (size_t) -1;
+
+                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
+                                        return -ENOMEM;
+
+                                key[n_key++] = c;
+                        }
+                        break;
+
+                case KEY:
+                        if (strchr(NEWLINE, c)) {
+                                state = PRE_KEY;
+                                line++;
+                                n_key = 0;
+                        } else if (c == '=') {
+                                state = PRE_VALUE;
+                                last_value_whitespace = (size_t) -1;
+                        } else {
+                                if (!strchr(WHITESPACE, c))
+                                        last_key_whitespace = (size_t) -1;
+                                else if (last_key_whitespace == (size_t) -1)
+                                         last_key_whitespace = n_key;
+
+                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
+                                        return -ENOMEM;
+
+                                key[n_key++] = c;
+                        }
+
+                        break;
+
+                case PRE_VALUE:
+                        if (strchr(NEWLINE, c)) {
+                                state = PRE_KEY;
+                                line++;
+                                key[n_key] = 0;
+
+                                if (value)
+                                        value[n_value] = 0;
+
+                                /* strip trailing whitespace from key */
+                                if (last_key_whitespace != (size_t) -1)
+                                        key[last_key_whitespace] = 0;
+
+                                r = push(fname, line, key, value, userdata, n_pushed);
+                                if (r < 0)
+                                        return r;
+
+                                n_key = 0;
+                                value = NULL;
+                                value_alloc = n_value = 0;
+
+                        } else if (c == '\'')
+                                state = SINGLE_QUOTE_VALUE;
+                        else if (c == '"')
+                                state = DOUBLE_QUOTE_VALUE;
+                        else if (c == '\\')
+                                state = VALUE_ESCAPE;
+                        else if (!strchr(WHITESPACE, c)) {
+                                state = VALUE;
+
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return  -ENOMEM;
+
+                                value[n_value++] = c;
+                        }
+
+                        break;
+
+                case VALUE:
+                        if (strchr(NEWLINE, c)) {
+                                state = PRE_KEY;
+                                line++;
+
+                                key[n_key] = 0;
+
+                                if (value)
+                                        value[n_value] = 0;
+
+                                /* Chomp off trailing whitespace from value */
+                                if (last_value_whitespace != (size_t) -1)
+                                        value[last_value_whitespace] = 0;
+
+                                /* strip trailing whitespace from key */
+                                if (last_key_whitespace != (size_t) -1)
+                                        key[last_key_whitespace] = 0;
+
+                                r = push(fname, line, key, value, userdata, n_pushed);
+                                if (r < 0)
+                                        return r;
+
+                                n_key = 0;
+                                value = NULL;
+                                value_alloc = n_value = 0;
+
+                        } else if (c == '\\') {
+                                state = VALUE_ESCAPE;
+                                last_value_whitespace = (size_t) -1;
+                        } else {
+                                if (!strchr(WHITESPACE, c))
+                                        last_value_whitespace = (size_t) -1;
+                                else if (last_value_whitespace == (size_t) -1)
+                                        last_value_whitespace = n_value;
+
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
+
+                                value[n_value++] = c;
+                        }
+
+                        break;
+
+                case VALUE_ESCAPE:
+                        state = VALUE;
+
+                        if (!strchr(NEWLINE, c)) {
+                                /* Escaped newlines we eat up entirely */
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
+
+                                value[n_value++] = c;
+                        }
+                        break;
+
+                case SINGLE_QUOTE_VALUE:
+                        if (c == '\'')
+                                state = PRE_VALUE;
+                        else {
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
+
+                                value[n_value++] = c;
+                        }
+
+                        break;
+
+                case DOUBLE_QUOTE_VALUE:
+                        if (c == '"')
+                                state = PRE_VALUE;
+                        else if (c == '\\')
+                                state = DOUBLE_QUOTE_VALUE_ESCAPE;
+                        else {
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
+
+                                value[n_value++] = c;
+                        }
+
+                        break;
+
+                case DOUBLE_QUOTE_VALUE_ESCAPE:
+                        state = DOUBLE_QUOTE_VALUE;
+
+                        if (c == '"') {
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
+                                value[n_value++] = '"';
+                        } else if (!strchr(NEWLINE, c)) {
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+3))
+                                        return -ENOMEM;
+                                value[n_value++] = '\\';
+                                value[n_value++] = c;
+                        }
+
+                        break;
+
+                case COMMENT:
+                        if (c == '\\')
+                                state = COMMENT_ESCAPE;
+                        else if (strchr(NEWLINE, c)) {
+                                state = PRE_KEY;
+                                line++;
+                        }
+                        break;
+
+                case COMMENT_ESCAPE:
+                        state = COMMENT;
+                        break;
+                }
+        }
+
+        if (IN_SET(state,
+                   PRE_VALUE,
+                   VALUE,
+                   VALUE_ESCAPE,
+                   SINGLE_QUOTE_VALUE,
+                   DOUBLE_QUOTE_VALUE,
+                   DOUBLE_QUOTE_VALUE_ESCAPE)) {
+
+                key[n_key] = 0;
+
+                if (value)
+                        value[n_value] = 0;
+
+                if (state == VALUE)
+                        if (last_value_whitespace != (size_t) -1)
+                                value[last_value_whitespace] = 0;
+
+                /* strip trailing whitespace from key */
+                if (last_key_whitespace != (size_t) -1)
+                        key[last_key_whitespace] = 0;
+
+                r = push(fname, line, key, value, userdata, n_pushed);
+                if (r < 0)
+                        return r;
+
+                value = NULL;
+        }
+
+        return 0;
+}
+
+static int check_utf8ness_and_warn(
+                const char *filename, unsigned line,
+                const char *key, char *value) {
+
+        if (!utf8_is_valid(key)) {
+                _cleanup_free_ char *p = NULL;
+
+                p = utf8_escape_invalid(key);
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "%s:%u: invalid UTF-8 in key '%s', ignoring.",
+                                       strna(filename), line, p);
+        }
+
+        if (value && !utf8_is_valid(value)) {
+                _cleanup_free_ char *p = NULL;
+
+                p = utf8_escape_invalid(value);
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.",
+                                       strna(filename), line, key, p);
+        }
+
+        return 0;
+}
+
+static int parse_env_file_push(
+                const char *filename, unsigned line,
+                const char *key, char *value,
+                void *userdata,
+                int *n_pushed) {
+
+        const char *k;
+        va_list aq, *ap = userdata;
+        int r;
+
+        r = check_utf8ness_and_warn(filename, line, key, value);
+        if (r < 0)
+                return r;
+
+        va_copy(aq, *ap);
+
+        while ((k = va_arg(aq, const char *))) {
+                char **v;
+
+                v = va_arg(aq, char **);
+
+                if (streq(key, k)) {
+                        va_end(aq);
+                        free(*v);
+                        *v = value;
+
+                        if (n_pushed)
+                                (*n_pushed)++;
+
+                        return 1;
+                }
+        }
+
+        va_end(aq);
+        free(value);
+
+        return 0;
+}
+
+int parse_env_filev(
+                FILE *f,
+                const char *fname,
+                va_list ap) {
+
+        int r, n_pushed = 0;
+        va_list aq;
+
+        va_copy(aq, ap);
+        r = parse_env_file_internal(f, fname, parse_env_file_push, &aq, &n_pushed);
+        va_end(aq);
+        if (r < 0)
+                return r;
+
+        return n_pushed;
+}
+
+int parse_env_file_sentinel(
+                FILE *f,
+                const char *fname,
+                ...) {
+
+        va_list ap;
+        int r;
+
+        va_start(ap, fname);
+        r = parse_env_filev(f, fname, ap);
+        va_end(ap);
+
+        return r;
+}
+
+static int load_env_file_push(
+                const char *filename, unsigned line,
+                const char *key, char *value,
+                void *userdata,
+                int *n_pushed) {
+        char ***m = userdata;
+        char *p;
+        int r;
+
+        r = check_utf8ness_and_warn(filename, line, key, value);
+        if (r < 0)
+                return r;
+
+        p = strjoin(key, "=", value);
+        if (!p)
+                return -ENOMEM;
+
+        r = strv_env_replace(m, p);
+        if (r < 0) {
+                free(p);
+                return r;
+        }
+
+        if (n_pushed)
+                (*n_pushed)++;
+
+        free(value);
+        return 0;
+}
+
+int load_env_file(FILE *f, const char *fname, char ***rl) {
+        char **m = NULL;
+        int r;
+
+        r = parse_env_file_internal(f, fname, load_env_file_push, &m, NULL);
+        if (r < 0) {
+                strv_free(m);
+                return r;
+        }
+
+        *rl = m;
+        return 0;
+}
+
+static int load_env_file_push_pairs(
+                const char *filename, unsigned line,
+                const char *key, char *value,
+                void *userdata,
+                int *n_pushed) {
+        char ***m = userdata;
+        int r;
+
+        r = check_utf8ness_and_warn(filename, line, key, value);
+        if (r < 0)
+                return r;
+
+        r = strv_extend(m, key);
+        if (r < 0)
+                return -ENOMEM;
+
+        if (!value) {
+                r = strv_extend(m, "");
+                if (r < 0)
+                        return -ENOMEM;
+        } else {
+                r = strv_push(m, value);
+                if (r < 0)
+                        return r;
+        }
+
+        if (n_pushed)
+                (*n_pushed)++;
+
+        return 0;
+}
+
+int load_env_file_pairs(FILE *f, const char *fname, char ***rl) {
+        char **m = NULL;
+        int r;
+
+        r = parse_env_file_internal(f, fname, load_env_file_push_pairs, &m, NULL);
+        if (r < 0) {
+                strv_free(m);
+                return r;
+        }
+
+        *rl = m;
+        return 0;
+}
+
+static int merge_env_file_push(
+                const char *filename, unsigned line,
+                const char *key, char *value,
+                void *userdata,
+                int *n_pushed) {
+
+        char ***env = userdata;
+        char *expanded_value;
+
+        assert(env);
+
+        if (!value) {
+                log_error("%s:%u: invalid syntax (around \"%s\"), ignoring.", strna(filename), line, key);
+                return 0;
+        }
+
+        if (!env_name_is_valid(key)) {
+                log_error("%s:%u: invalid variable name \"%s\", ignoring.", strna(filename), line, key);
+                free(value);
+                return 0;
+        }
+
+        expanded_value = replace_env(value, *env,
+                                     REPLACE_ENV_USE_ENVIRONMENT|
+                                     REPLACE_ENV_ALLOW_BRACELESS|
+                                     REPLACE_ENV_ALLOW_EXTENDED);
+        if (!expanded_value)
+                return -ENOMEM;
+
+        free_and_replace(value, expanded_value);
+
+        return load_env_file_push(filename, line, key, value, env, n_pushed);
+}
+
+int merge_env_file(
+                char ***env,
+                FILE *f,
+                const char *fname) {
+
+        /* NOTE: this function supports braceful and braceless variable expansions,
+         * plus "extended" substitutions, unlike other exported parsing functions.
+         */
+
+        return parse_env_file_internal(f, fname, merge_env_file_push, env, NULL);
+}
+
+static void write_env_var(FILE *f, const char *v) {
+        const char *p;
+
+        p = strchr(v, '=');
+        if (!p) {
+                /* Fallback */
+                fputs_unlocked(v, f);
+                fputc_unlocked('\n', f);
+                return;
+        }
+
+        p++;
+        fwrite_unlocked(v, 1, p-v, f);
+
+        if (string_has_cc(p, NULL) || chars_intersect(p, WHITESPACE SHELL_NEED_QUOTES)) {
+                fputc_unlocked('"', f);
+
+                for (; *p; p++) {
+                        if (strchr(SHELL_NEED_ESCAPE, *p))
+                                fputc_unlocked('\\', f);
+
+                        fputc_unlocked(*p, f);
+                }
+
+                fputc_unlocked('"', f);
+        } else
+                fputs_unlocked(p, f);
+
+        fputc_unlocked('\n', f);
+}
+
+int write_env_file(const char *fname, char **l) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *p = NULL;
+        char **i;
+        int r;
+
+        assert(fname);
+
+        r = fopen_temporary(fname, &f, &p);
+        if (r < 0)
+                return r;
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+        (void) fchmod_umask(fileno(f), 0644);
+
+        STRV_FOREACH(i, l)
+                write_env_var(f, *i);
+
+        r = fflush_and_check(f);
+        if (r >= 0) {
+                if (rename(p, fname) >= 0)
+                        return 0;
+
+                r = -errno;
+        }
+
+        unlink(p);
+        return r;
+}
diff --git a/src/basic/env-file.h b/src/basic/env-file.h
new file mode 100644
index 0000000..e1ca195
--- /dev/null
+++ b/src/basic/env-file.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "macro.h"
+
+int parse_env_filev(FILE *f, const char *fname, va_list ap);
+int parse_env_file_sentinel(FILE *f, const char *fname, ...) _sentinel_;
+#define parse_env_file(f, fname, ...) parse_env_file_sentinel(f, fname, __VA_ARGS__, NULL)
+int load_env_file(FILE *f, const char *fname, char ***l);
+int load_env_file_pairs(FILE *f, const char *fname, char ***l);
+
+int merge_env_file(char ***env, FILE *f, const char *fname);
+
+int write_env_file(const char *fname, char **l);
diff --git a/src/basic/env-util.c b/src/basic/env-util.c
new file mode 100644
index 0000000..fd449dc
--- /dev/null
+++ b/src/basic/env-util.c
@@ -0,0 +1,752 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "env-util.h"
+#include "escape.h"
+#include "extract-word.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "utf8.h"
+
+#define VALID_CHARS_ENV_NAME                    \
+        DIGITS LETTERS                          \
+        "_"
+
+static bool env_name_is_valid_n(const char *e, size_t n) {
+        const char *p;
+
+        if (!e)
+                return false;
+
+        if (n <= 0)
+                return false;
+
+        if (e[0] >= '0' && e[0] <= '9')
+                return false;
+
+        /* POSIX says the overall size of the environment block cannot
+         * be > ARG_MAX, an individual assignment hence cannot be
+         * either. Discounting the equal sign and trailing NUL this
+         * hence leaves ARG_MAX-2 as longest possible variable
+         * name. */
+        if (n > (size_t) sysconf(_SC_ARG_MAX) - 2)
+                return false;
+
+        for (p = e; p < e + n; p++)
+                if (!strchr(VALID_CHARS_ENV_NAME, *p))
+                        return false;
+
+        return true;
+}
+
+bool env_name_is_valid(const char *e) {
+        if (!e)
+                return false;
+
+        return env_name_is_valid_n(e, strlen(e));
+}
+
+bool env_value_is_valid(const char *e) {
+        if (!e)
+                return false;
+
+        if (!utf8_is_valid(e))
+                return false;
+
+        /* bash allows tabs and newlines in environment variables, and so
+         * should we */
+        if (string_has_cc(e, "\t\n"))
+                return false;
+
+        /* POSIX says the overall size of the environment block cannot
+         * be > ARG_MAX, an individual assignment hence cannot be
+         * either. Discounting the shortest possible variable name of
+         * length 1, the equal sign and trailing NUL this hence leaves
+         * ARG_MAX-3 as longest possible variable value. */
+        if (strlen(e) > (size_t) sysconf(_SC_ARG_MAX) - 3)
+                return false;
+
+        return true;
+}
+
+bool env_assignment_is_valid(const char *e) {
+        const char *eq;
+
+        eq = strchr(e, '=');
+        if (!eq)
+                return false;
+
+        if (!env_name_is_valid_n(e, eq - e))
+                return false;
+
+        if (!env_value_is_valid(eq + 1))
+                return false;
+
+        /* POSIX says the overall size of the environment block cannot
+         * be > ARG_MAX, hence the individual variable assignments
+         * cannot be either, but let's leave room for one trailing NUL
+         * byte. */
+        if (strlen(e) > (size_t) sysconf(_SC_ARG_MAX) - 1)
+                return false;
+
+        return true;
+}
+
+bool strv_env_is_valid(char **e) {
+        char **p, **q;
+
+        STRV_FOREACH(p, e) {
+                size_t k;
+
+                if (!env_assignment_is_valid(*p))
+                        return false;
+
+                /* Check if there are duplicate assignments */
+                k = strcspn(*p, "=");
+                STRV_FOREACH(q, p + 1)
+                        if (strneq(*p, *q, k) && (*q)[k] == '=')
+                                return false;
+        }
+
+        return true;
+}
+
+bool strv_env_name_is_valid(char **l) {
+        char **p;
+
+        STRV_FOREACH(p, l) {
+                if (!env_name_is_valid(*p))
+                        return false;
+
+                if (strv_contains(p + 1, *p))
+                        return false;
+        }
+
+        return true;
+}
+
+bool strv_env_name_or_assignment_is_valid(char **l) {
+        char **p;
+
+        STRV_FOREACH(p, l) {
+                if (!env_assignment_is_valid(*p) && !env_name_is_valid(*p))
+                        return false;
+
+                if (strv_contains(p + 1, *p))
+                        return false;
+        }
+
+        return true;
+}
+
+static int env_append(char **r, char ***k, char **a) {
+        assert(r);
+        assert(k);
+        assert(*k >= r);
+
+        if (!a)
+                return 0;
+
+        /* Expects the following arguments: 'r' shall point to the beginning of an strv we are going to append to, 'k'
+         * to a pointer pointing to the NULL entry at the end of the same array. 'a' shall point to another strv.
+         *
+         * This call adds every entry of 'a' to 'r', either overriding an existing matching entry, or appending to it.
+         *
+         * This call assumes 'r' has enough pre-allocated space to grow by all of 'a''s items. */
+
+        for (; *a; a++) {
+                char **j, *c;
+                size_t n;
+
+                n = strcspn(*a, "=");
+                if ((*a)[n] == '=')
+                        n++;
+
+                for (j = r; j < *k; j++)
+                        if (strneq(*j, *a, n))
+                                break;
+
+                c = strdup(*a);
+                if (!c)
+                        return -ENOMEM;
+
+                if (j >= *k) { /* Append to the end? */
+                        (*k)[0] = c;
+                        (*k)[1] = NULL;
+                        (*k)++;
+                } else
+                        free_and_replace(*j, c); /* Override existing item */
+        }
+
+        return 0;
+}
+
+char **strv_env_merge(size_t n_lists, ...) {
+        _cleanup_strv_free_ char **ret = NULL;
+        size_t n = 0, i;
+        char **l, **k;
+        va_list ap;
+
+        /* Merges an arbitrary number of environment sets */
+
+        va_start(ap, n_lists);
+        for (i = 0; i < n_lists; i++) {
+                l = va_arg(ap, char**);
+                n += strv_length(l);
+        }
+        va_end(ap);
+
+        ret = new(char*, n+1);
+        if (!ret)
+                return NULL;
+
+        *ret = NULL;
+        k = ret;
+
+        va_start(ap, n_lists);
+        for (i = 0; i < n_lists; i++) {
+                l = va_arg(ap, char**);
+                if (env_append(ret, &k, l) < 0) {
+                        va_end(ap);
+                        return NULL;
+                }
+        }
+        va_end(ap);
+
+        return TAKE_PTR(ret);
+}
+
+static bool env_match(const char *t, const char *pattern) {
+        assert(t);
+        assert(pattern);
+
+        /* pattern a matches string a
+         *         a matches a=
+         *         a matches a=b
+         *         a= matches a=
+         *         a=b matches a=b
+         *         a= does not match a
+         *         a=b does not match a=
+         *         a=b does not match a
+         *         a=b does not match a=c */
+
+        if (streq(t, pattern))
+                return true;
+
+        if (!strchr(pattern, '=')) {
+                size_t l = strlen(pattern);
+
+                return strneq(t, pattern, l) && t[l] == '=';
+        }
+
+        return false;
+}
+
+static bool env_entry_has_name(const char *entry, const char *name) {
+        const char *t;
+
+        assert(entry);
+        assert(name);
+
+        t = startswith(entry, name);
+        if (!t)
+                return false;
+
+        return *t == '=';
+}
+
+char **strv_env_delete(char **x, size_t n_lists, ...) {
+        size_t n, i = 0;
+        char **k, **r;
+        va_list ap;
+
+        /* Deletes every entry from x that is mentioned in the other
+         * string lists */
+
+        n = strv_length(x);
+
+        r = new(char*, n+1);
+        if (!r)
+                return NULL;
+
+        STRV_FOREACH(k, x) {
+                size_t v;
+
+                va_start(ap, n_lists);
+                for (v = 0; v < n_lists; v++) {
+                        char **l, **j;
+
+                        l = va_arg(ap, char**);
+                        STRV_FOREACH(j, l)
+                                if (env_match(*k, *j))
+                                        goto skip;
+                }
+                va_end(ap);
+
+                r[i] = strdup(*k);
+                if (!r[i]) {
+                        strv_free(r);
+                        return NULL;
+                }
+
+                i++;
+                continue;
+
+        skip:
+                va_end(ap);
+        }
+
+        r[i] = NULL;
+
+        assert(i <= n);
+
+        return r;
+}
+
+char **strv_env_unset(char **l, const char *p) {
+
+        char **f, **t;
+
+        if (!l)
+                return NULL;
+
+        assert(p);
+
+        /* Drops every occurrence of the env var setting p in the
+         * string list. Edits in-place. */
+
+        for (f = t = l; *f; f++) {
+
+                if (env_match(*f, p)) {
+                        free(*f);
+                        continue;
+                }
+
+                *(t++) = *f;
+        }
+
+        *t = NULL;
+        return l;
+}
+
+char **strv_env_unset_many(char **l, ...) {
+        char **f, **t;
+
+        if (!l)
+                return NULL;
+
+        /* Like strv_env_unset() but applies many at once. Edits in-place. */
+
+        for (f = t = l; *f; f++) {
+                bool found = false;
+                const char *p;
+                va_list ap;
+
+                va_start(ap, l);
+
+                while ((p = va_arg(ap, const char*))) {
+                        if (env_match(*f, p)) {
+                                found = true;
+                                break;
+                        }
+                }
+
+                va_end(ap);
+
+                if (found) {
+                        free(*f);
+                        continue;
+                }
+
+                *(t++) = *f;
+        }
+
+        *t = NULL;
+        return l;
+}
+
+int strv_env_replace(char ***l, char *p) {
+        const char *t, *name;
+        char **f;
+        int r;
+
+        assert(p);
+
+        /* Replace first occurrence of the env var or add a new one in the string list. Drop other occurrences. Edits
+         * in-place. Does not copy p.  p must be a valid key=value assignment.
+         */
+
+        t = strchr(p, '=');
+        if (!t)
+                return -EINVAL;
+
+        name = strndupa(p, t - p);
+
+        STRV_FOREACH(f, *l)
+                if (env_entry_has_name(*f, name)) {
+                        free_and_replace(*f, p);
+                        strv_env_unset(f + 1, *f);
+                        return 0;
+                }
+
+        /* We didn't find a match, we need to append p or create a new strv */
+        r = strv_push(l, p);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+char **strv_env_set(char **x, const char *p) {
+        _cleanup_strv_free_ char **ret = NULL;
+        size_t n, m;
+        char **k;
+
+        /* Overrides the env var setting of p, returns a new copy */
+
+        n = strv_length(x);
+        m = n + 2;
+        if (m < n) /* overflow? */
+                return NULL;
+
+        ret = new(char*, m);
+        if (!ret)
+                return NULL;
+
+        *ret = NULL;
+        k = ret;
+
+        if (env_append(ret, &k, x) < 0)
+                return NULL;
+
+        if (env_append(ret, &k, STRV_MAKE(p)) < 0)
+                return NULL;
+
+        return TAKE_PTR(ret);
+}
+
+char *strv_env_get_n(char **l, const char *name, size_t k, unsigned flags) {
+        char **i;
+
+        assert(name);
+
+        if (k <= 0)
+                return NULL;
+
+        STRV_FOREACH_BACKWARDS(i, l)
+                if (strneq(*i, name, k) &&
+                    (*i)[k] == '=')
+                        return *i + k + 1;
+
+        if (flags & REPLACE_ENV_USE_ENVIRONMENT) {
+                const char *t;
+
+                t = strndupa(name, k);
+                return getenv(t);
+        };
+
+        return NULL;
+}
+
+char *strv_env_get(char **l, const char *name) {
+        assert(name);
+
+        return strv_env_get_n(l, name, strlen(name), 0);
+}
+
+char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const char *p, void *userdata), void *userdata) {
+        char **p, **q;
+        int k = 0;
+
+        STRV_FOREACH(p, e) {
+                size_t n;
+                bool duplicate = false;
+
+                if (!env_assignment_is_valid(*p)) {
+                        if (invalid_callback)
+                                invalid_callback(*p, userdata);
+                        free(*p);
+                        continue;
+                }
+
+                n = strcspn(*p, "=");
+                STRV_FOREACH(q, p + 1)
+                        if (strneq(*p, *q, n) && (*q)[n] == '=') {
+                                duplicate = true;
+                                break;
+                        }
+
+                if (duplicate) {
+                        free(*p);
+                        continue;
+                }
+
+                e[k++] = *p;
+        }
+
+        if (e)
+                e[k] = NULL;
+
+        return e;
+}
+
+char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
+        enum {
+                WORD,
+                CURLY,
+                VARIABLE,
+                VARIABLE_RAW,
+                TEST,
+                DEFAULT_VALUE,
+                ALTERNATE_VALUE,
+        } state = WORD;
+
+        const char *e, *word = format, *test_value;
+        char *k;
+        _cleanup_free_ char *r = NULL;
+        size_t i, len;
+        int nest = 0;
+
+        assert(format);
+
+        for (e = format, i = 0; *e && i < n; e ++, i ++)
+                switch (state) {
+
+                case WORD:
+                        if (*e == '$')
+                                state = CURLY;
+                        break;
+
+                case CURLY:
+                        if (*e == '{') {
+                                k = strnappend(r, word, e-word-1);
+                                if (!k)
+                                        return NULL;
+
+                                free_and_replace(r, k);
+
+                                word = e-1;
+                                state = VARIABLE;
+                                nest++;
+                        } else if (*e == '$') {
+                                k = strnappend(r, word, e-word);
+                                if (!k)
+                                        return NULL;
+
+                                free_and_replace(r, k);
+
+                                word = e+1;
+                                state = WORD;
+
+                        } else if (flags & REPLACE_ENV_ALLOW_BRACELESS && strchr(VALID_CHARS_ENV_NAME, *e)) {
+                                k = strnappend(r, word, e-word-1);
+                                if (!k)
+                                        return NULL;
+
+                                free_and_replace(r, k);
+
+                                word = e-1;
+                                state = VARIABLE_RAW;
+
+                        } else
+                                state = WORD;
+                        break;
+
+                case VARIABLE:
+                        if (*e == '}') {
+                                const char *t;
+
+                                t = strv_env_get_n(env, word+2, e-word-2, flags);
+
+                                k = strappend(r, t);
+                                if (!k)
+                                        return NULL;
+
+                                free_and_replace(r, k);
+
+                                word = e+1;
+                                state = WORD;
+                        } else if (*e == ':') {
+                                if (!(flags & REPLACE_ENV_ALLOW_EXTENDED))
+                                        /* Treat this as unsupported syntax, i.e. do no replacement */
+                                        state = WORD;
+                                else {
+                                        len = e-word-2;
+                                        state = TEST;
+                                }
+                        }
+                        break;
+
+                case TEST:
+                        if (*e == '-')
+                                state = DEFAULT_VALUE;
+                        else if (*e == '+')
+                                state = ALTERNATE_VALUE;
+                        else {
+                                state = WORD;
+                                break;
+                        }
+
+                        test_value = e+1;
+                        break;
+
+                case DEFAULT_VALUE: /* fall through */
+                case ALTERNATE_VALUE:
+                        assert(flags & REPLACE_ENV_ALLOW_EXTENDED);
+
+                        if (*e == '{') {
+                                nest++;
+                                break;
+                        }
+
+                        if (*e != '}')
+                                break;
+
+                        nest--;
+                        if (nest == 0) {
+                                const char *t;
+                                _cleanup_free_ char *v = NULL;
+
+                                t = strv_env_get_n(env, word+2, len, flags);
+
+                                if (t && state == ALTERNATE_VALUE)
+                                        t = v = replace_env_n(test_value, e-test_value, env, flags);
+                                else if (!t && state == DEFAULT_VALUE)
+                                        t = v = replace_env_n(test_value, e-test_value, env, flags);
+
+                                k = strappend(r, t);
+                                if (!k)
+                                        return NULL;
+
+                                free_and_replace(r, k);
+
+                                word = e+1;
+                                state = WORD;
+                        }
+                        break;
+
+                case VARIABLE_RAW:
+                        assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
+
+                        if (!strchr(VALID_CHARS_ENV_NAME, *e)) {
+                                const char *t;
+
+                                t = strv_env_get_n(env, word+1, e-word-1, flags);
+
+                                k = strappend(r, t);
+                                if (!k)
+                                        return NULL;
+
+                                free_and_replace(r, k);
+
+                                word = e--;
+                                i--;
+                                state = WORD;
+                        }
+                        break;
+                }
+
+        if (state == VARIABLE_RAW) {
+                const char *t;
+
+                assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
+
+                t = strv_env_get_n(env, word+1, e-word-1, flags);
+                return strappend(r, t);
+        } else
+                return strnappend(r, word, e-word);
+}
+
+char **replace_env_argv(char **argv, char **env) {
+        char **ret, **i;
+        size_t k = 0, l = 0;
+
+        l = strv_length(argv);
+
+        ret = new(char*, l+1);
+        if (!ret)
+                return NULL;
+
+        STRV_FOREACH(i, argv) {
+
+                /* If $FOO appears as single word, replace it by the split up variable */
+                if ((*i)[0] == '$' && !IN_SET((*i)[1], '{', '$')) {
+                        char *e;
+                        char **w, **m = NULL;
+                        size_t q;
+
+                        e = strv_env_get(env, *i+1);
+                        if (e) {
+                                int r;
+
+                                r = strv_split_extract(&m, e, WHITESPACE, EXTRACT_RELAX|EXTRACT_QUOTES);
+                                if (r < 0) {
+                                        ret[k] = NULL;
+                                        strv_free(ret);
+                                        return NULL;
+                                }
+                        } else
+                                m = NULL;
+
+                        q = strv_length(m);
+                        l = l + q - 1;
+
+                        w = reallocarray(ret, l + 1, sizeof(char *));
+                        if (!w) {
+                                ret[k] = NULL;
+                                strv_free(ret);
+                                strv_free(m);
+                                return NULL;
+                        }
+
+                        ret = w;
+                        if (m) {
+                                memcpy(ret + k, m, q * sizeof(char*));
+                                free(m);
+                        }
+
+                        k += q;
+                        continue;
+                }
+
+                /* If ${FOO} appears as part of a word, replace it by the variable as-is */
+                ret[k] = replace_env(*i, env, 0);
+                if (!ret[k]) {
+                        strv_free(ret);
+                        return NULL;
+                }
+                k++;
+        }
+
+        ret[k] = NULL;
+        return ret;
+}
+
+int getenv_bool(const char *p) {
+        const char *e;
+
+        e = getenv(p);
+        if (!e)
+                return -ENXIO;
+
+        return parse_boolean(e);
+}
+
+int getenv_bool_secure(const char *p) {
+        const char *e;
+
+        e = secure_getenv(p);
+        if (!e)
+                return -ENXIO;
+
+        return parse_boolean(e);
+}
diff --git a/src/basic/env-util.h b/src/basic/env-util.h
new file mode 100644
index 0000000..d54f996
--- /dev/null
+++ b/src/basic/env-util.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#include "macro.h"
+#include "string.h"
+
+bool env_name_is_valid(const char *e);
+bool env_value_is_valid(const char *e);
+bool env_assignment_is_valid(const char *e);
+
+enum {
+        REPLACE_ENV_USE_ENVIRONMENT = 1 << 0,
+        REPLACE_ENV_ALLOW_BRACELESS = 1 << 1,
+        REPLACE_ENV_ALLOW_EXTENDED  = 1 << 2,
+};
+
+char *replace_env_n(const char *format, size_t n, char **env, unsigned flags);
+char **replace_env_argv(char **argv, char **env);
+
+static inline char *replace_env(const char *format, char **env, unsigned flags) {
+        return replace_env_n(format, strlen(format), env, flags);
+}
+
+bool strv_env_is_valid(char **e);
+#define strv_env_clean(l) strv_env_clean_with_callback(l, NULL, NULL)
+char **strv_env_clean_with_callback(char **l, void (*invalid_callback)(const char *p, void *userdata), void *userdata);
+
+bool strv_env_name_is_valid(char **l);
+bool strv_env_name_or_assignment_is_valid(char **l);
+
+char **strv_env_merge(size_t n_lists, ...);
+char **strv_env_delete(char **x, size_t n_lists, ...); /* New copy */
+
+char **strv_env_set(char **x, const char *p); /* New copy ... */
+char **strv_env_unset(char **l, const char *p); /* In place ... */
+char **strv_env_unset_many(char **l, ...) _sentinel_;
+int strv_env_replace(char ***l, char *p); /* In place ... */
+
+char *strv_env_get_n(char **l, const char *name, size_t k, unsigned flags) _pure_;
+char *strv_env_get(char **x, const char *n) _pure_;
+
+int getenv_bool(const char *p);
+int getenv_bool_secure(const char *p);
diff --git a/src/basic/errno-list.c b/src/basic/errno-list.c
new file mode 100644
index 0000000..44cc570
--- /dev/null
+++ b/src/basic/errno-list.c
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <string.h>
+
+#include "errno-list.h"
+#include "macro.h"
+
+static const struct errno_name* lookup_errno(register const char *str,
+                                             register GPERF_LEN_TYPE len);
+
+#include "errno-from-name.h"
+#include "errno-to-name.h"
+
+const char *errno_to_name(int id) {
+
+        if (id < 0)
+                id = -id;
+
+        if ((size_t) id >= ELEMENTSOF(errno_names))
+                return NULL;
+
+        return errno_names[id];
+}
+
+int errno_from_name(const char *name) {
+        const struct errno_name *sc;
+
+        assert(name);
+
+        sc = lookup_errno(name, strlen(name));
+        if (!sc)
+                return -EINVAL;
+
+        assert(sc->id > 0);
+        return sc->id;
+}
diff --git a/src/basic/errno-list.h b/src/basic/errno-list.h
new file mode 100644
index 0000000..9c639b4
--- /dev/null
+++ b/src/basic/errno-list.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+/*
+ * MAX_ERRNO is defined as 4095 in linux/err.h
+ * We use the same value here.
+ */
+#define ERRNO_MAX 4095
+
+const char *errno_to_name(int id);
+int errno_from_name(const char *name);
+static inline bool errno_is_valid(int n) {
+        return n > 0 && n <= ERRNO_MAX;
+}
diff --git a/src/basic/errno-to-name.awk b/src/basic/errno-to-name.awk
new file mode 100644
index 0000000..0878aba
--- /dev/null
+++ b/src/basic/errno-to-name.awk
@@ -0,0 +1,9 @@
+BEGIN{
+        print "static const char* const errno_names[] = { "
+}
+!/EDEADLOCK/ && !/EWOULDBLOCK/ && !/ENOTSUP/ {
+        printf "        [%s] = \"%s\",\n", $1, $1
+}
+END{
+        print "};"
+}
diff --git a/src/basic/escape.c b/src/basic/escape.c
new file mode 100644
index 0000000..5f71515
--- /dev/null
+++ b/src/basic/escape.c
@@ -0,0 +1,506 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "escape.h"
+#include "hexdecoct.h"
+#include "macro.h"
+#include "utf8.h"
+
+int cescape_char(char c, char *buf) {
+        char *buf_old = buf;
+
+        /* Needs space for 4 characters in the buffer */
+
+        switch (c) {
+
+                case '\a':
+                        *(buf++) = '\\';
+                        *(buf++) = 'a';
+                        break;
+                case '\b':
+                        *(buf++) = '\\';
+                        *(buf++) = 'b';
+                        break;
+                case '\f':
+                        *(buf++) = '\\';
+                        *(buf++) = 'f';
+                        break;
+                case '\n':
+                        *(buf++) = '\\';
+                        *(buf++) = 'n';
+                        break;
+                case '\r':
+                        *(buf++) = '\\';
+                        *(buf++) = 'r';
+                        break;
+                case '\t':
+                        *(buf++) = '\\';
+                        *(buf++) = 't';
+                        break;
+                case '\v':
+                        *(buf++) = '\\';
+                        *(buf++) = 'v';
+                        break;
+                case '\\':
+                        *(buf++) = '\\';
+                        *(buf++) = '\\';
+                        break;
+                case '"':
+                        *(buf++) = '\\';
+                        *(buf++) = '"';
+                        break;
+                case '\'':
+                        *(buf++) = '\\';
+                        *(buf++) = '\'';
+                        break;
+
+                default:
+                        /* For special chars we prefer octal over
+                         * hexadecimal encoding, simply because glib's
+                         * g_strescape() does the same */
+                        if ((c < ' ') || (c >= 127)) {
+                                *(buf++) = '\\';
+                                *(buf++) = octchar((unsigned char) c >> 6);
+                                *(buf++) = octchar((unsigned char) c >> 3);
+                                *(buf++) = octchar((unsigned char) c);
+                        } else
+                                *(buf++) = c;
+                        break;
+        }
+
+        return buf - buf_old;
+}
+
+char *cescape_length(const char *s, size_t n) {
+        const char *f;
+        char *r, *t;
+
+        assert(s || n == 0);
+
+        /* Does C style string escaping. May be reversed with
+         * cunescape(). */
+
+        r = new(char, n*4 + 1);
+        if (!r)
+                return NULL;
+
+        for (f = s, t = r; f < s + n; f++)
+                t += cescape_char(*f, t);
+
+        *t = 0;
+
+        return r;
+}
+
+char *cescape(const char *s) {
+        assert(s);
+
+        return cescape_length(s, strlen(s));
+}
+
+int cunescape_one(const char *p, size_t length, char32_t *ret, bool *eight_bit) {
+        int r = 1;
+
+        assert(p);
+        assert(ret);
+
+        /* Unescapes C style. Returns the unescaped character in ret.
+         * Sets *eight_bit to true if the escaped sequence either fits in
+         * one byte in UTF-8 or is a non-unicode literal byte and should
+         * instead be copied directly.
+         */
+
+        if (length != (size_t) -1 && length < 1)
+                return -EINVAL;
+
+        switch (p[0]) {
+
+        case 'a':
+                *ret = '\a';
+                break;
+        case 'b':
+                *ret = '\b';
+                break;
+        case 'f':
+                *ret = '\f';
+                break;
+        case 'n':
+                *ret = '\n';
+                break;
+        case 'r':
+                *ret = '\r';
+                break;
+        case 't':
+                *ret = '\t';
+                break;
+        case 'v':
+                *ret = '\v';
+                break;
+        case '\\':
+                *ret = '\\';
+                break;
+        case '"':
+                *ret = '"';
+                break;
+        case '\'':
+                *ret = '\'';
+                break;
+
+        case 's':
+                /* This is an extension of the XDG syntax files */
+                *ret = ' ';
+                break;
+
+        case 'x': {
+                /* hexadecimal encoding */
+                int a, b;
+
+                if (length != (size_t) -1 && length < 3)
+                        return -EINVAL;
+
+                a = unhexchar(p[1]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unhexchar(p[2]);
+                if (b < 0)
+                        return -EINVAL;
+
+                /* Don't allow NUL bytes */
+                if (a == 0 && b == 0)
+                        return -EINVAL;
+
+                *ret = (a << 4U) | b;
+                *eight_bit = true;
+                r = 3;
+                break;
+        }
+
+        case 'u': {
+                /* C++11 style 16bit unicode */
+
+                int a[4];
+                size_t i;
+                uint32_t c;
+
+                if (length != (size_t) -1 && length < 5)
+                        return -EINVAL;
+
+                for (i = 0; i < 4; i++) {
+                        a[i] = unhexchar(p[1 + i]);
+                        if (a[i] < 0)
+                                return a[i];
+                }
+
+                c = ((uint32_t) a[0] << 12U) | ((uint32_t) a[1] << 8U) | ((uint32_t) a[2] << 4U) | (uint32_t) a[3];
+
+                /* Don't allow 0 chars */
+                if (c == 0)
+                        return -EINVAL;
+
+                *ret = c;
+                r = 5;
+                break;
+        }
+
+        case 'U': {
+                /* C++11 style 32bit unicode */
+
+                int a[8];
+                size_t i;
+                char32_t c;
+
+                if (length != (size_t) -1 && length < 9)
+                        return -EINVAL;
+
+                for (i = 0; i < 8; i++) {
+                        a[i] = unhexchar(p[1 + i]);
+                        if (a[i] < 0)
+                                return a[i];
+                }
+
+                c = ((uint32_t) a[0] << 28U) | ((uint32_t) a[1] << 24U) | ((uint32_t) a[2] << 20U) | ((uint32_t) a[3] << 16U) |
+                    ((uint32_t) a[4] << 12U) | ((uint32_t) a[5] <<  8U) | ((uint32_t) a[6] <<  4U) |  (uint32_t) a[7];
+
+                /* Don't allow 0 chars */
+                if (c == 0)
+                        return -EINVAL;
+
+                /* Don't allow invalid code points */
+                if (!unichar_is_valid(c))
+                        return -EINVAL;
+
+                *ret = c;
+                r = 9;
+                break;
+        }
+
+        case '0':
+        case '1':
+        case '2':
+        case '3':
+        case '4':
+        case '5':
+        case '6':
+        case '7': {
+                /* octal encoding */
+                int a, b, c;
+                char32_t m;
+
+                if (length != (size_t) -1 && length < 3)
+                        return -EINVAL;
+
+                a = unoctchar(p[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unoctchar(p[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unoctchar(p[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                /* don't allow NUL bytes */
+                if (a == 0 && b == 0 && c == 0)
+                        return -EINVAL;
+
+                /* Don't allow bytes above 255 */
+                m = ((uint32_t) a << 6U) | ((uint32_t) b << 3U) | (uint32_t) c;
+                if (m > 255)
+                        return -EINVAL;
+
+                *ret = m;
+                *eight_bit = true;
+                r = 3;
+                break;
+        }
+
+        default:
+                return -EINVAL;
+        }
+
+        return r;
+}
+
+int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret) {
+        char *r, *t;
+        const char *f;
+        size_t pl;
+
+        assert(s);
+        assert(ret);
+
+        /* Undoes C style string escaping, and optionally prefixes it. */
+
+        pl = strlen_ptr(prefix);
+
+        r = new(char, pl+length+1);
+        if (!r)
+                return -ENOMEM;
+
+        if (prefix)
+                memcpy(r, prefix, pl);
+
+        for (f = s, t = r + pl; f < s + length; f++) {
+                size_t remaining;
+                bool eight_bit = false;
+                char32_t u;
+                int k;
+
+                remaining = s + length - f;
+                assert(remaining > 0);
+
+                if (*f != '\\') {
+                        /* A literal, copy verbatim */
+                        *(t++) = *f;
+                        continue;
+                }
+
+                if (remaining == 1) {
+                        if (flags & UNESCAPE_RELAX) {
+                                /* A trailing backslash, copy verbatim */
+                                *(t++) = *f;
+                                continue;
+                        }
+
+                        free(r);
+                        return -EINVAL;
+                }
+
+                k = cunescape_one(f + 1, remaining - 1, &u, &eight_bit);
+                if (k < 0) {
+                        if (flags & UNESCAPE_RELAX) {
+                                /* Invalid escape code, let's take it literal then */
+                                *(t++) = '\\';
+                                continue;
+                        }
+
+                        free(r);
+                        return k;
+                }
+
+                f += k;
+                if (eight_bit)
+                        /* One byte? Set directly as specified */
+                        *(t++) = u;
+                else
+                        /* Otherwise encode as multi-byte UTF-8 */
+                        t += utf8_encode_unichar(t, u);
+        }
+
+        *t = 0;
+
+        *ret = r;
+        return t - r;
+}
+
+int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret) {
+        return cunescape_length_with_prefix(s, length, NULL, flags, ret);
+}
+
+int cunescape(const char *s, UnescapeFlags flags, char **ret) {
+        return cunescape_length(s, strlen(s), flags, ret);
+}
+
+char *xescape(const char *s, const char *bad) {
+        char *r, *t;
+        const char *f;
+
+        /* Escapes all chars in bad, in addition to \ and all special
+         * chars, in \xFF style escaping. May be reversed with
+         * cunescape(). */
+
+        r = new(char, strlen(s) * 4 + 1);
+        if (!r)
+                return NULL;
+
+        for (f = s, t = r; *f; f++) {
+
+                if ((*f < ' ') || (*f >= 127) ||
+                    (*f == '\\') || strchr(bad, *f)) {
+                        *(t++) = '\\';
+                        *(t++) = 'x';
+                        *(t++) = hexchar(*f >> 4);
+                        *(t++) = hexchar(*f);
+                } else
+                        *(t++) = *f;
+        }
+
+        *t = 0;
+
+        return r;
+}
+
+char *octescape(const char *s, size_t len) {
+        char *r, *t;
+        const char *f;
+
+        /* Escapes all chars in bad, in addition to \ and " chars,
+         * in \nnn style escaping. */
+
+        r = new(char, len * 4 + 1);
+        if (!r)
+                return NULL;
+
+        for (f = s, t = r; f < s + len; f++) {
+
+                if (*f < ' ' || *f >= 127 || IN_SET(*f, '\\', '"')) {
+                        *(t++) = '\\';
+                        *(t++) = '0' + (*f >> 6);
+                        *(t++) = '0' + ((*f >> 3) & 8);
+                        *(t++) = '0' + (*f & 8);
+                } else
+                        *(t++) = *f;
+        }
+
+        *t = 0;
+
+        return r;
+
+}
+
+static char *strcpy_backslash_escaped(char *t, const char *s, const char *bad, bool escape_tab_nl) {
+        assert(bad);
+
+        for (; *s; s++) {
+                if (escape_tab_nl && IN_SET(*s, '\n', '\t')) {
+                        *(t++) = '\\';
+                        *(t++) = *s == '\n' ? 'n' : 't';
+                        continue;
+                }
+
+                if (*s == '\\' || strchr(bad, *s))
+                        *(t++) = '\\';
+
+                *(t++) = *s;
+        }
+
+        return t;
+}
+
+char *shell_escape(const char *s, const char *bad) {
+        char *r, *t;
+
+        r = new(char, strlen(s)*2+1);
+        if (!r)
+                return NULL;
+
+        t = strcpy_backslash_escaped(r, s, bad, false);
+        *t = 0;
+
+        return r;
+}
+
+char* shell_maybe_quote(const char *s, EscapeStyle style) {
+        const char *p;
+        char *r, *t;
+
+        assert(s);
+
+        /* Encloses a string in quotes if necessary to make it OK as a shell
+         * string. Note that we treat benign UTF-8 characters as needing
+         * escaping too, but that should be OK. */
+
+        for (p = s; *p; p++)
+                if (*p <= ' ' ||
+                    *p >= 127 ||
+                    strchr(SHELL_NEED_QUOTES, *p))
+                        break;
+
+        if (!*p)
+                return strdup(s);
+
+        r = new(char, (style == ESCAPE_POSIX) + 1 + strlen(s)*2 + 1 + 1);
+        if (!r)
+                return NULL;
+
+        t = r;
+        if (style == ESCAPE_BACKSLASH)
+                *(t++) = '"';
+        else if (style == ESCAPE_POSIX) {
+                *(t++) = '$';
+                *(t++) = '\'';
+        } else
+                assert_not_reached("Bad EscapeStyle");
+
+        t = mempcpy(t, s, p - s);
+
+        if (style == ESCAPE_BACKSLASH)
+                t = strcpy_backslash_escaped(t, p, SHELL_NEED_ESCAPE, false);
+        else
+                t = strcpy_backslash_escaped(t, p, SHELL_NEED_ESCAPE_POSIX, true);
+
+        if (style == ESCAPE_BACKSLASH)
+                *(t++) = '"';
+        else
+                *(t++) = '\'';
+        *t = 0;
+
+        return r;
+}
diff --git a/src/basic/escape.h b/src/basic/escape.h
new file mode 100644
index 0000000..5156209
--- /dev/null
+++ b/src/basic/escape.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <uchar.h>
+
+#include "string-util.h"
+#include "missing_type.h"
+
+/* What characters are special in the shell? */
+/* must be escaped outside and inside double-quotes */
+#define SHELL_NEED_ESCAPE "\"\\`$"
+
+/* Those that can be escaped or double-quoted.
+ *
+ * Stricly speaking, ! does not need to be escaped, except in interactive
+ * mode, but let's be extra nice to the user and quote ! in case this
+ * output is ever used in interactive mode. */
+#define SHELL_NEED_QUOTES SHELL_NEED_ESCAPE GLOB_CHARS "'()<>|&;!"
+
+/* Note that we assume control characters would need to be escaped too in
+ * addition to the "special" characters listed here, if they appear in the
+ * string. Current users disallow control characters. Also '"' shall not
+ * be escaped.
+ */
+#define SHELL_NEED_ESCAPE_POSIX "\\\'"
+
+typedef enum UnescapeFlags {
+        UNESCAPE_RELAX = 1,
+} UnescapeFlags;
+
+typedef enum EscapeStyle {
+        ESCAPE_BACKSLASH = 1,
+        ESCAPE_POSIX = 2,
+} EscapeStyle;
+
+char *cescape(const char *s);
+char *cescape_length(const char *s, size_t n);
+int cescape_char(char c, char *buf);
+
+int cunescape(const char *s, UnescapeFlags flags, char **ret);
+int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret);
+int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret);
+int cunescape_one(const char *p, size_t length, char32_t *ret, bool *eight_bit);
+
+char *xescape(const char *s, const char *bad);
+char *octescape(const char *s, size_t len);
+
+char *shell_escape(const char *s, const char *bad);
+char* shell_maybe_quote(const char *s, EscapeStyle style);
diff --git a/src/basic/ether-addr-util.c b/src/basic/ether-addr-util.c
new file mode 100644
index 0000000..e875696
--- /dev/null
+++ b/src/basic/ether-addr-util.c
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <net/ethernet.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "ether-addr-util.h"
+#include "macro.h"
+#include "string-util.h"
+
+char* ether_addr_to_string(const struct ether_addr *addr, char buffer[ETHER_ADDR_TO_STRING_MAX]) {
+        assert(addr);
+        assert(buffer);
+
+        /* Like ether_ntoa() but uses %02x instead of %x to print
+         * ethernet addresses, which makes them look less funny. Also,
+         * doesn't use a static buffer. */
+
+        sprintf(buffer, "%02x:%02x:%02x:%02x:%02x:%02x",
+                addr->ether_addr_octet[0],
+                addr->ether_addr_octet[1],
+                addr->ether_addr_octet[2],
+                addr->ether_addr_octet[3],
+                addr->ether_addr_octet[4],
+                addr->ether_addr_octet[5]);
+
+        return buffer;
+}
+
+int ether_addr_compare(const struct ether_addr *a, const struct ether_addr *b) {
+        return memcmp(a, b, ETH_ALEN);
+}
+
+static void ether_addr_hash_func(const struct ether_addr *p, struct siphash *state) {
+        siphash24_compress(p, sizeof(struct ether_addr), state);
+}
+
+DEFINE_HASH_OPS(ether_addr_hash_ops, struct ether_addr, ether_addr_hash_func, ether_addr_compare);
+
+int ether_addr_from_string(const char *s, struct ether_addr *ret) {
+        size_t pos = 0, n, field;
+        char sep = '\0';
+        const char *hex = HEXDIGITS, *hexoff;
+        size_t x;
+        bool touched;
+
+#define parse_fields(v)                                         \
+        for (field = 0; field < ELEMENTSOF(v); field++) {       \
+                touched = false;                                \
+                for (n = 0; n < (2 * sizeof(v[0])); n++) {      \
+                        if (s[pos] == '\0')                     \
+                                break;                          \
+                        hexoff = strchr(hex, s[pos]);           \
+                        if (!hexoff)                            \
+                                break;                          \
+                        assert(hexoff >= hex);                  \
+                        x = hexoff - hex;                       \
+                        if (x >= 16)                            \
+                                x -= 6; /* A-F */               \
+                        assert(x < 16);                         \
+                        touched = true;                         \
+                        v[field] <<= 4;                         \
+                        v[field] += x;                          \
+                        pos++;                                  \
+                }                                               \
+                if (!touched)                                   \
+                        return -EINVAL;                         \
+                if (field < (ELEMENTSOF(v)-1)) {                \
+                        if (s[pos] != sep)                      \
+                                return -EINVAL;                 \
+                        else                                    \
+                                pos++;                          \
+                }                                               \
+        }
+
+        assert(s);
+        assert(ret);
+
+        s += strspn(s, WHITESPACE);
+        sep = s[strspn(s, hex)];
+
+        if (sep == '.') {
+                uint16_t shorts[3] = { 0 };
+
+                parse_fields(shorts);
+
+                if (s[pos] != '\0')
+                        return -EINVAL;
+
+                for (n = 0; n < ELEMENTSOF(shorts); n++) {
+                        ret->ether_addr_octet[2*n] = ((shorts[n] & (uint16_t)0xff00) >> 8);
+                        ret->ether_addr_octet[2*n + 1] = (shorts[n] & (uint16_t)0x00ff);
+                }
+
+        } else if (IN_SET(sep, ':', '-')) {
+                struct ether_addr out = ETHER_ADDR_NULL;
+
+                parse_fields(out.ether_addr_octet);
+
+                if (s[pos] != '\0')
+                        return -EINVAL;
+
+                for (n = 0; n < ELEMENTSOF(out.ether_addr_octet); n++)
+                        ret->ether_addr_octet[n] = out.ether_addr_octet[n];
+
+        } else
+                return -EINVAL;
+
+        return 0;
+}
diff --git a/src/basic/ether-addr-util.h b/src/basic/ether-addr-util.h
new file mode 100644
index 0000000..4e44b30
--- /dev/null
+++ b/src/basic/ether-addr-util.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <net/ethernet.h>
+#include <stdbool.h>
+
+#include "hash-funcs.h"
+
+#define ETHER_ADDR_FORMAT_STR "%02X%02X%02X%02X%02X%02X"
+#define ETHER_ADDR_FORMAT_VAL(x) (x).ether_addr_octet[0], (x).ether_addr_octet[1], (x).ether_addr_octet[2], (x).ether_addr_octet[3], (x).ether_addr_octet[4], (x).ether_addr_octet[5]
+
+#define ETHER_ADDR_TO_STRING_MAX (3*6)
+char* ether_addr_to_string(const struct ether_addr *addr, char buffer[ETHER_ADDR_TO_STRING_MAX]);
+
+int ether_addr_compare(const struct ether_addr *a, const struct ether_addr *b);
+static inline bool ether_addr_equal(const struct ether_addr *a, const struct ether_addr *b) {
+        return ether_addr_compare(a, b) == 0;
+}
+
+#define ETHER_ADDR_NULL ((const struct ether_addr){})
+
+static inline bool ether_addr_is_null(const struct ether_addr *addr) {
+        return ether_addr_equal(addr, &ETHER_ADDR_NULL);
+}
+
+int ether_addr_from_string(const char *s, struct ether_addr *ret);
+
+extern const struct hash_ops ether_addr_hash_ops;
diff --git a/src/basic/extract-word.c b/src/basic/extract-word.c
new file mode 100644
index 0000000..a861b56
--- /dev/null
+++ b/src/basic/extract-word.c
@@ -0,0 +1,285 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+
+#include "alloc-util.h"
+#include "escape.h"
+#include "extract-word.h"
+#include "log.h"
+#include "macro.h"
+#include "string-util.h"
+#include "utf8.h"
+
+int extract_first_word(const char **p, char **ret, const char *separators, ExtractFlags flags) {
+        _cleanup_free_ char *s = NULL;
+        size_t allocated = 0, sz = 0;
+        char c;
+        int r;
+
+        char quote = 0;                 /* 0 or ' or " */
+        bool backslash = false;         /* whether we've just seen a backslash */
+
+        assert(p);
+        assert(ret);
+
+        /* Bail early if called after last value or with no input */
+        if (!*p)
+                goto finish;
+        c = **p;
+
+        if (!separators)
+                separators = WHITESPACE;
+
+        /* Parses the first word of a string, and returns it in
+         * *ret. Removes all quotes in the process. When parsing fails
+         * (because of an uneven number of quotes or similar), leaves
+         * the pointer *p at the first invalid character. */
+
+        if (flags & EXTRACT_DONT_COALESCE_SEPARATORS)
+                if (!GREEDY_REALLOC(s, allocated, sz+1))
+                        return -ENOMEM;
+
+        for (;; (*p)++, c = **p) {
+                if (c == 0)
+                        goto finish_force_terminate;
+                else if (strchr(separators, c)) {
+                        if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) {
+                                (*p)++;
+                                goto finish_force_next;
+                        }
+                } else {
+                        /* We found a non-blank character, so we will always
+                         * want to return a string (even if it is empty),
+                         * allocate it here. */
+                        if (!GREEDY_REALLOC(s, allocated, sz+1))
+                                return -ENOMEM;
+                        break;
+                }
+        }
+
+        for (;; (*p)++, c = **p) {
+                if (backslash) {
+                        if (!GREEDY_REALLOC(s, allocated, sz+7))
+                                return -ENOMEM;
+
+                        if (c == 0) {
+                                if ((flags & EXTRACT_CUNESCAPE_RELAX) &&
+                                    (!quote || flags & EXTRACT_RELAX)) {
+                                        /* If we find an unquoted trailing backslash and we're in
+                                         * EXTRACT_CUNESCAPE_RELAX mode, keep it verbatim in the
+                                         * output.
+                                         *
+                                         * Unbalanced quotes will only be allowed in EXTRACT_RELAX
+                                         * mode, EXTRACT_CUNESCAPE_RELAX mode does not allow them.
+                                         */
+                                        s[sz++] = '\\';
+                                        goto finish_force_terminate;
+                                }
+                                if (flags & EXTRACT_RELAX)
+                                        goto finish_force_terminate;
+                                return -EINVAL;
+                        }
+
+                        if (flags & EXTRACT_CUNESCAPE) {
+                                bool eight_bit = false;
+                                char32_t u;
+
+                                r = cunescape_one(*p, (size_t) -1, &u, &eight_bit);
+                                if (r < 0) {
+                                        if (flags & EXTRACT_CUNESCAPE_RELAX) {
+                                                s[sz++] = '\\';
+                                                s[sz++] = c;
+                                        } else
+                                                return -EINVAL;
+                                } else {
+                                        (*p) += r - 1;
+
+                                        if (eight_bit)
+                                                s[sz++] = u;
+                                        else
+                                                sz += utf8_encode_unichar(s + sz, u);
+                                }
+                        } else
+                                s[sz++] = c;
+
+                        backslash = false;
+
+                } else if (quote) {     /* inside either single or double quotes */
+                        for (;; (*p)++, c = **p) {
+                                if (c == 0) {
+                                        if (flags & EXTRACT_RELAX)
+                                                goto finish_force_terminate;
+                                        return -EINVAL;
+                                } else if (c == quote) {        /* found the end quote */
+                                        quote = 0;
+                                        break;
+                                } else if (c == '\\' && !(flags & EXTRACT_RETAIN_ESCAPE)) {
+                                        backslash = true;
+                                        break;
+                                } else {
+                                        if (!GREEDY_REALLOC(s, allocated, sz+2))
+                                                return -ENOMEM;
+
+                                        s[sz++] = c;
+                                }
+                        }
+
+                } else {
+                        for (;; (*p)++, c = **p) {
+                                if (c == 0)
+                                        goto finish_force_terminate;
+                                else if (IN_SET(c, '\'', '"') && (flags & EXTRACT_QUOTES)) {
+                                        quote = c;
+                                        break;
+                                } else if (c == '\\' && !(flags & EXTRACT_RETAIN_ESCAPE)) {
+                                        backslash = true;
+                                        break;
+                                } else if (strchr(separators, c)) {
+                                        if (flags & EXTRACT_DONT_COALESCE_SEPARATORS) {
+                                                (*p)++;
+                                                goto finish_force_next;
+                                        }
+                                        /* Skip additional coalesced separators. */
+                                        for (;; (*p)++, c = **p) {
+                                                if (c == 0)
+                                                        goto finish_force_terminate;
+                                                if (!strchr(separators, c))
+                                                        break;
+                                        }
+                                        goto finish;
+
+                                } else {
+                                        if (!GREEDY_REALLOC(s, allocated, sz+2))
+                                                return -ENOMEM;
+
+                                        s[sz++] = c;
+                                }
+                        }
+                }
+        }
+
+finish_force_terminate:
+        *p = NULL;
+finish:
+        if (!s) {
+                *p = NULL;
+                *ret = NULL;
+                return 0;
+        }
+
+finish_force_next:
+        s[sz] = 0;
+        *ret = TAKE_PTR(s);
+
+        return 1;
+}
+
+int extract_first_word_and_warn(
+                const char **p,
+                char **ret,
+                const char *separators,
+                ExtractFlags flags,
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *rvalue) {
+
+        /* Try to unquote it, if it fails, warn about it and try again
+         * but this time using EXTRACT_CUNESCAPE_RELAX to keep the
+         * backslashes verbatim in invalid escape sequences. */
+
+        const char *save;
+        int r;
+
+        save = *p;
+        r = extract_first_word(p, ret, separators, flags);
+        if (r >= 0)
+                return r;
+
+        if (r == -EINVAL && !(flags & EXTRACT_CUNESCAPE_RELAX)) {
+
+                /* Retry it with EXTRACT_CUNESCAPE_RELAX. */
+                *p = save;
+                r = extract_first_word(p, ret, separators, flags|EXTRACT_CUNESCAPE_RELAX);
+                if (r >= 0) {
+                        /* It worked this time, hence it must have been an invalid escape sequence. */
+                        log_syntax(unit, LOG_WARNING, filename, line, EINVAL, "Ignoring unknown escape sequences: \"%s\"", *ret);
+                        return r;
+                }
+
+                /* If it's still EINVAL; then it must be unbalanced quoting, report this. */
+                if (r == -EINVAL)
+                        return log_syntax(unit, LOG_ERR, filename, line, r, "Unbalanced quoting, ignoring: \"%s\"", rvalue);
+        }
+
+        /* Can be any error, report it */
+        return log_syntax(unit, LOG_ERR, filename, line, r, "Unable to decode word \"%s\", ignoring: %m", rvalue);
+}
+
+/* We pass ExtractFlags as unsigned int (to avoid undefined behaviour when passing
+ * an object that undergoes default argument promotion as an argument to va_start).
+ * Let's make sure that ExtractFlags fits into an unsigned int. */
+assert_cc(sizeof(enum ExtractFlags) <= sizeof(unsigned));
+
+int extract_many_words(const char **p, const char *separators, unsigned flags, ...) {
+        va_list ap;
+        char **l;
+        int n = 0, i, c, r;
+
+        /* Parses a number of words from a string, stripping any
+         * quotes if necessary. */
+
+        assert(p);
+
+        /* Count how many words are expected */
+        va_start(ap, flags);
+        for (;;) {
+                if (!va_arg(ap, char **))
+                        break;
+                n++;
+        }
+        va_end(ap);
+
+        if (n <= 0)
+                return 0;
+
+        /* Read all words into a temporary array */
+        l = newa0(char*, n);
+        for (c = 0; c < n; c++) {
+
+                r = extract_first_word(p, &l[c], separators, flags);
+                if (r < 0) {
+                        int j;
+
+                        for (j = 0; j < c; j++)
+                                free(l[j]);
+
+                        return r;
+                }
+
+                if (r == 0)
+                        break;
+        }
+
+        /* If we managed to parse all words, return them in the passed
+         * in parameters */
+        va_start(ap, flags);
+        for (i = 0; i < n; i++) {
+                char **v;
+
+                v = va_arg(ap, char **);
+                assert(v);
+
+                *v = l[i];
+        }
+        va_end(ap);
+
+        return c;
+}
diff --git a/src/basic/extract-word.h b/src/basic/extract-word.h
new file mode 100644
index 0000000..705ebbe
--- /dev/null
+++ b/src/basic/extract-word.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "macro.h"
+
+typedef enum ExtractFlags {
+        EXTRACT_RELAX                    = 1 << 0,
+        EXTRACT_CUNESCAPE                = 1 << 1,
+        EXTRACT_CUNESCAPE_RELAX          = 1 << 2,
+        EXTRACT_QUOTES                   = 1 << 3,
+        EXTRACT_DONT_COALESCE_SEPARATORS = 1 << 4,
+        EXTRACT_RETAIN_ESCAPE            = 1 << 5,
+} ExtractFlags;
+
+int extract_first_word(const char **p, char **ret, const char *separators, ExtractFlags flags);
+int extract_first_word_and_warn(const char **p, char **ret, const char *separators, ExtractFlags flags, const char *unit, const char *filename, unsigned line, const char *rvalue);
+int extract_many_words(const char **p, const char *separators, unsigned flags, ...) _sentinel_;
diff --git a/src/basic/fd-util.c b/src/basic/fd-util.c
new file mode 100644
index 0000000..3e6ef5a
--- /dev/null
+++ b/src/basic/fd-util.c
@@ -0,0 +1,967 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "copy.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "macro.h"
+#include "memfd-util.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "socket-util.h"
+#include "stdio-util.h"
+#include "util.h"
+#include "tmpfile-util.h"
+
+int close_nointr(int fd) {
+        assert(fd >= 0);
+
+        if (close(fd) >= 0)
+                return 0;
+
+        /*
+         * Just ignore EINTR; a retry loop is the wrong thing to do on
+         * Linux.
+         *
+         * http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html
+         * https://bugzilla.gnome.org/show_bug.cgi?id=682819
+         * http://utcc.utoronto.ca/~cks/space/blog/unix/CloseEINTR
+         * https://sites.google.com/site/michaelsafyan/software-engineering/checkforeintrwheninvokingclosethinkagain
+         */
+        if (errno == EINTR)
+                return 0;
+
+        return -errno;
+}
+
+int safe_close(int fd) {
+
+        /*
+         * Like close_nointr() but cannot fail. Guarantees errno is
+         * unchanged. Is a NOP with negative fds passed, and returns
+         * -1, so that it can be used in this syntax:
+         *
+         * fd = safe_close(fd);
+         */
+
+        if (fd >= 0) {
+                PROTECT_ERRNO;
+
+                /* The kernel might return pretty much any error code
+                 * via close(), but the fd will be closed anyway. The
+                 * only condition we want to check for here is whether
+                 * the fd was invalid at all... */
+
+                assert_se(close_nointr(fd) != -EBADF);
+        }
+
+        return -1;
+}
+
+void safe_close_pair(int p[static 2]) {
+        assert(p);
+
+        if (p[0] == p[1]) {
+                /* Special case pairs which use the same fd in both
+                 * directions... */
+                p[0] = p[1] = safe_close(p[0]);
+                return;
+        }
+
+        p[0] = safe_close(p[0]);
+        p[1] = safe_close(p[1]);
+}
+
+void close_many(const int fds[], size_t n_fd) {
+        size_t i;
+
+        assert(fds || n_fd <= 0);
+
+        for (i = 0; i < n_fd; i++)
+                safe_close(fds[i]);
+}
+
+int fclose_nointr(FILE *f) {
+        assert(f);
+
+        /* Same as close_nointr(), but for fclose() */
+
+        if (fclose(f) == 0)
+                return 0;
+
+        if (errno == EINTR)
+                return 0;
+
+        return -errno;
+}
+
+FILE* safe_fclose(FILE *f) {
+
+        /* Same as safe_close(), but for fclose() */
+
+        if (f) {
+                PROTECT_ERRNO;
+
+                assert_se(fclose_nointr(f) != -EBADF);
+        }
+
+        return NULL;
+}
+
+DIR* safe_closedir(DIR *d) {
+
+        if (d) {
+                PROTECT_ERRNO;
+
+                assert_se(closedir(d) >= 0 || errno != EBADF);
+        }
+
+        return NULL;
+}
+
+int fd_nonblock(int fd, bool nonblock) {
+        int flags, nflags;
+
+        assert(fd >= 0);
+
+        flags = fcntl(fd, F_GETFL, 0);
+        if (flags < 0)
+                return -errno;
+
+        if (nonblock)
+                nflags = flags | O_NONBLOCK;
+        else
+                nflags = flags & ~O_NONBLOCK;
+
+        if (nflags == flags)
+                return 0;
+
+        if (fcntl(fd, F_SETFL, nflags) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int fd_cloexec(int fd, bool cloexec) {
+        int flags, nflags;
+
+        assert(fd >= 0);
+
+        flags = fcntl(fd, F_GETFD, 0);
+        if (flags < 0)
+                return -errno;
+
+        if (cloexec)
+                nflags = flags | FD_CLOEXEC;
+        else
+                nflags = flags & ~FD_CLOEXEC;
+
+        if (nflags == flags)
+                return 0;
+
+        if (fcntl(fd, F_SETFD, nflags) < 0)
+                return -errno;
+
+        return 0;
+}
+
+_pure_ static bool fd_in_set(int fd, const int fdset[], size_t n_fdset) {
+        size_t i;
+
+        assert(n_fdset == 0 || fdset);
+
+        for (i = 0; i < n_fdset; i++)
+                if (fdset[i] == fd)
+                        return true;
+
+        return false;
+}
+
+static int get_max_fd(void) {
+        struct rlimit rl;
+        rlim_t m;
+
+        /* Return the highest possible fd, based RLIMIT_NOFILE, but enforcing FD_SETSIZE-1 as lower boundary
+         * and INT_MAX as upper boundary. */
+
+        if (getrlimit(RLIMIT_NOFILE, &rl) < 0)
+                return -errno;
+
+        m = MAX(rl.rlim_cur, rl.rlim_max);
+        if (m < FD_SETSIZE) /* Let's always cover at least 1024 fds */
+                return FD_SETSIZE-1;
+
+        if (m == RLIM_INFINITY || m > INT_MAX) /* Saturate on overflow. After all fds are "int", hence can
+                                                * never be above INT_MAX */
+                return INT_MAX;
+
+        return (int) (m - 1);
+}
+
+int close_all_fds(const int except[], size_t n_except) {
+        _cleanup_closedir_ DIR *d = NULL;
+        struct dirent *de;
+        int r = 0;
+
+        assert(n_except == 0 || except);
+
+        d = opendir("/proc/self/fd");
+        if (!d) {
+                int fd, max_fd;
+
+                /* When /proc isn't available (for example in chroots) the fallback is brute forcing through
+                 * the fd table */
+
+                max_fd = get_max_fd();
+                if (max_fd < 0)
+                        return max_fd;
+
+                for (fd = 3; fd >= 0; fd = fd < max_fd ? fd + 1 : -1) {
+                        int q;
+
+                        if (fd_in_set(fd, except, n_except))
+                                continue;
+
+                        q = close_nointr(fd);
+                        if (q < 0 && q != -EBADF && r >= 0)
+                                r = q;
+                }
+
+                return r;
+        }
+
+        FOREACH_DIRENT(de, d, return -errno) {
+                int fd = -1, q;
+
+                if (safe_atoi(de->d_name, &fd) < 0)
+                        /* Let's better ignore this, just in case */
+                        continue;
+
+                if (fd < 3)
+                        continue;
+
+                if (fd == dirfd(d))
+                        continue;
+
+                if (fd_in_set(fd, except, n_except))
+                        continue;
+
+                q = close_nointr(fd);
+                if (q < 0 && q != -EBADF && r >= 0) /* Valgrind has its own FD and doesn't want to have it closed */
+                        r = q;
+        }
+
+        return r;
+}
+
+int same_fd(int a, int b) {
+        struct stat sta, stb;
+        pid_t pid;
+        int r, fa, fb;
+
+        assert(a >= 0);
+        assert(b >= 0);
+
+        /* Compares two file descriptors. Note that semantics are
+         * quite different depending on whether we have kcmp() or we
+         * don't. If we have kcmp() this will only return true for
+         * dup()ed file descriptors, but not otherwise. If we don't
+         * have kcmp() this will also return true for two fds of the same
+         * file, created by separate open() calls. Since we use this
+         * call mostly for filtering out duplicates in the fd store
+         * this difference hopefully doesn't matter too much. */
+
+        if (a == b)
+                return true;
+
+        /* Try to use kcmp() if we have it. */
+        pid = getpid_cached();
+        r = kcmp(pid, pid, KCMP_FILE, a, b);
+        if (r == 0)
+                return true;
+        if (r > 0)
+                return false;
+        if (!IN_SET(errno, ENOSYS, EACCES, EPERM))
+                return -errno;
+
+        /* We don't have kcmp(), use fstat() instead. */
+        if (fstat(a, &sta) < 0)
+                return -errno;
+
+        if (fstat(b, &stb) < 0)
+                return -errno;
+
+        if ((sta.st_mode & S_IFMT) != (stb.st_mode & S_IFMT))
+                return false;
+
+        /* We consider all device fds different, since two device fds
+         * might refer to quite different device contexts even though
+         * they share the same inode and backing dev_t. */
+
+        if (S_ISCHR(sta.st_mode) || S_ISBLK(sta.st_mode))
+                return false;
+
+        if (sta.st_dev != stb.st_dev || sta.st_ino != stb.st_ino)
+                return false;
+
+        /* The fds refer to the same inode on disk, let's also check
+         * if they have the same fd flags. This is useful to
+         * distinguish the read and write side of a pipe created with
+         * pipe(). */
+        fa = fcntl(a, F_GETFL);
+        if (fa < 0)
+                return -errno;
+
+        fb = fcntl(b, F_GETFL);
+        if (fb < 0)
+                return -errno;
+
+        return fa == fb;
+}
+
+void cmsg_close_all(struct msghdr *mh) {
+        struct cmsghdr *cmsg;
+
+        assert(mh);
+
+        CMSG_FOREACH(cmsg, mh)
+                if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS)
+                        close_many((int*) CMSG_DATA(cmsg), (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int));
+}
+
+bool fdname_is_valid(const char *s) {
+        const char *p;
+
+        /* Validates a name for $LISTEN_FDNAMES. We basically allow
+         * everything ASCII that's not a control character. Also, as
+         * special exception the ":" character is not allowed, as we
+         * use that as field separator in $LISTEN_FDNAMES.
+         *
+         * Note that the empty string is explicitly allowed
+         * here. However, we limit the length of the names to 255
+         * characters. */
+
+        if (!s)
+                return false;
+
+        for (p = s; *p; p++) {
+                if (*p < ' ')
+                        return false;
+                if (*p >= 127)
+                        return false;
+                if (*p == ':')
+                        return false;
+        }
+
+        return p - s < 256;
+}
+
+int fd_get_path(int fd, char **ret) {
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        int r;
+
+        xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+        r = readlink_malloc(procfs_path, ret);
+        if (r == -ENOENT) {
+                /* ENOENT can mean two things: that the fd does not exist or that /proc is not mounted. Let's make
+                 * things debuggable and distuingish the two. */
+
+                if (access("/proc/self/fd/", F_OK) < 0)
+                        /* /proc is not available or not set up properly, we're most likely in some chroot
+                         * environment. */
+                        return errno == ENOENT ? -EOPNOTSUPP : -errno;
+
+                return -EBADF; /* The directory exists, hence it's the fd that doesn't. */
+        }
+
+        return r;
+}
+
+int move_fd(int from, int to, int cloexec) {
+        int r;
+
+        /* Move fd 'from' to 'to', make sure FD_CLOEXEC remains equal if requested, and release the old fd. If
+         * 'cloexec' is passed as -1, the original FD_CLOEXEC is inherited for the new fd. If it is 0, it is turned
+         * off, if it is > 0 it is turned on. */
+
+        if (from < 0)
+                return -EBADF;
+        if (to < 0)
+                return -EBADF;
+
+        if (from == to) {
+
+                if (cloexec >= 0) {
+                        r = fd_cloexec(to, cloexec);
+                        if (r < 0)
+                                return r;
+                }
+
+                return to;
+        }
+
+        if (cloexec < 0) {
+                int fl;
+
+                fl = fcntl(from, F_GETFD, 0);
+                if (fl < 0)
+                        return -errno;
+
+                cloexec = !!(fl & FD_CLOEXEC);
+        }
+
+        r = dup3(from, to, cloexec ? O_CLOEXEC : 0);
+        if (r < 0)
+                return -errno;
+
+        assert(r == to);
+
+        safe_close(from);
+
+        return to;
+}
+
+int acquire_data_fd(const void *data, size_t size, unsigned flags) {
+
+        _cleanup_close_pair_ int pipefds[2] = { -1, -1 };
+        char pattern[] = "/dev/shm/data-fd-XXXXXX";
+        _cleanup_close_ int fd = -1;
+        int isz = 0, r;
+        ssize_t n;
+        off_t f;
+
+        assert(data || size == 0);
+
+        /* Acquire a read-only file descriptor that when read from returns the specified data. This is much more
+         * complex than I wish it was. But here's why:
+         *
+         * a) First we try to use memfds. They are the best option, as we can seal them nicely to make them
+         *    read-only. Unfortunately they require kernel 3.17, and – at the time of writing – we still support 3.14.
+         *
+         * b) Then, we try classic pipes. They are the second best options, as we can close the writing side, retaining
+         *    a nicely read-only fd in the reading side. However, they are by default quite small, and unprivileged
+         *    clients can only bump their size to a system-wide limit, which might be quite low.
+         *
+         * c) Then, we try an O_TMPFILE file in /dev/shm (that dir is the only suitable one known to exist from
+         *    earliest boot on). To make it read-only we open the fd a second time with O_RDONLY via
+         *    /proc/self/<fd>. Unfortunately O_TMPFILE is not available on older kernels on tmpfs.
+         *
+         * d) Finally, we try creating a regular file in /dev/shm, which we then delete.
+         *
+         * It sucks a bit that depending on the situation we return very different objects here, but that's Linux I
+         * figure. */
+
+        if (size == 0 && ((flags & ACQUIRE_NO_DEV_NULL) == 0)) {
+                /* As a special case, return /dev/null if we have been called for an empty data block */
+                r = open("/dev/null", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+                if (r < 0)
+                        return -errno;
+
+                return r;
+        }
+
+        if ((flags & ACQUIRE_NO_MEMFD) == 0) {
+                fd = memfd_new("data-fd");
+                if (fd < 0)
+                        goto try_pipe;
+
+                n = write(fd, data, size);
+                if (n < 0)
+                        return -errno;
+                if ((size_t) n != size)
+                        return -EIO;
+
+                f = lseek(fd, 0, SEEK_SET);
+                if (f != 0)
+                        return -errno;
+
+                r = memfd_set_sealed(fd);
+                if (r < 0)
+                        return r;
+
+                return TAKE_FD(fd);
+        }
+
+try_pipe:
+        if ((flags & ACQUIRE_NO_PIPE) == 0) {
+                if (pipe2(pipefds, O_CLOEXEC|O_NONBLOCK) < 0)
+                        return -errno;
+
+                isz = fcntl(pipefds[1], F_GETPIPE_SZ, 0);
+                if (isz < 0)
+                        return -errno;
+
+                if ((size_t) isz < size) {
+                        isz = (int) size;
+                        if (isz < 0 || (size_t) isz != size)
+                                return -E2BIG;
+
+                        /* Try to bump the pipe size */
+                        (void) fcntl(pipefds[1], F_SETPIPE_SZ, isz);
+
+                        /* See if that worked */
+                        isz = fcntl(pipefds[1], F_GETPIPE_SZ, 0);
+                        if (isz < 0)
+                                return -errno;
+
+                        if ((size_t) isz < size)
+                                goto try_dev_shm;
+                }
+
+                n = write(pipefds[1], data, size);
+                if (n < 0)
+                        return -errno;
+                if ((size_t) n != size)
+                        return -EIO;
+
+                (void) fd_nonblock(pipefds[0], false);
+
+                return TAKE_FD(pipefds[0]);
+        }
+
+try_dev_shm:
+        if ((flags & ACQUIRE_NO_TMPFILE) == 0) {
+                fd = open("/dev/shm", O_RDWR|O_TMPFILE|O_CLOEXEC, 0500);
+                if (fd < 0)
+                        goto try_dev_shm_without_o_tmpfile;
+
+                n = write(fd, data, size);
+                if (n < 0)
+                        return -errno;
+                if ((size_t) n != size)
+                        return -EIO;
+
+                /* Let's reopen the thing, in order to get an O_RDONLY fd for the original O_RDWR one */
+                return fd_reopen(fd, O_RDONLY|O_CLOEXEC);
+        }
+
+try_dev_shm_without_o_tmpfile:
+        if ((flags & ACQUIRE_NO_REGULAR) == 0) {
+                fd = mkostemp_safe(pattern);
+                if (fd < 0)
+                        return fd;
+
+                n = write(fd, data, size);
+                if (n < 0) {
+                        r = -errno;
+                        goto unlink_and_return;
+                }
+                if ((size_t) n != size) {
+                        r = -EIO;
+                        goto unlink_and_return;
+                }
+
+                /* Let's reopen the thing, in order to get an O_RDONLY fd for the original O_RDWR one */
+                r = open(pattern, O_RDONLY|O_CLOEXEC);
+                if (r < 0)
+                        r = -errno;
+
+        unlink_and_return:
+                (void) unlink(pattern);
+                return r;
+        }
+
+        return -EOPNOTSUPP;
+}
+
+/* When the data is smaller or equal to 64K, try to place the copy in a memfd/pipe */
+#define DATA_FD_MEMORY_LIMIT (64U*1024U)
+
+/* If memfd/pipe didn't work out, then let's use a file in /tmp up to a size of 1M. If it's large than that use /var/tmp instead. */
+#define DATA_FD_TMP_LIMIT (1024U*1024U)
+
+int fd_duplicate_data_fd(int fd) {
+
+        _cleanup_close_ int copy_fd = -1, tmp_fd = -1;
+        _cleanup_free_ void *remains = NULL;
+        size_t remains_size = 0;
+        const char *td;
+        struct stat st;
+        int r;
+
+        /* Creates a 'data' fd from the specified source fd, containing all the same data in a read-only fashion, but
+         * independent of it (i.e. the source fd can be closed and unmounted after this call succeeded). Tries to be
+         * somewhat smart about where to place the data. In the best case uses a memfd(). If memfd() are not supported
+         * uses a pipe instead. For larger data will use an unlinked file in /tmp, and for even larger data one in
+         * /var/tmp. */
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        /* For now, let's only accept regular files, sockets, pipes and char devices */
+        if (S_ISDIR(st.st_mode))
+                return -EISDIR;
+        if (S_ISLNK(st.st_mode))
+                return -ELOOP;
+        if (!S_ISREG(st.st_mode) && !S_ISSOCK(st.st_mode) && !S_ISFIFO(st.st_mode) && !S_ISCHR(st.st_mode))
+                return -EBADFD;
+
+        /* If we have reason to believe the data is bounded in size, then let's use memfds or pipes as backing fd. Note
+         * that we use the reported regular file size only as a hint, given that there are plenty special files in
+         * /proc and /sys which report a zero file size but can be read from. */
+
+        if (!S_ISREG(st.st_mode) || st.st_size < DATA_FD_MEMORY_LIMIT) {
+
+                /* Try a memfd first */
+                copy_fd = memfd_new("data-fd");
+                if (copy_fd >= 0) {
+                        off_t f;
+
+                        r = copy_bytes(fd, copy_fd, DATA_FD_MEMORY_LIMIT, 0);
+                        if (r < 0)
+                                return r;
+
+                        f = lseek(copy_fd, 0, SEEK_SET);
+                        if (f != 0)
+                                return -errno;
+
+                        if (r == 0) {
+                                /* Did it fit into the limit? If so, we are done. */
+                                r = memfd_set_sealed(copy_fd);
+                                if (r < 0)
+                                        return r;
+
+                                return TAKE_FD(copy_fd);
+                        }
+
+                        /* Hmm, pity, this didn't fit. Let's fall back to /tmp then, see below */
+
+                } else {
+                        _cleanup_(close_pairp) int pipefds[2] = { -1, -1 };
+                        int isz;
+
+                        /* If memfds aren't available, use a pipe. Set O_NONBLOCK so that we will get EAGAIN rather
+                         * then block indefinitely when we hit the pipe size limit */
+
+                        if (pipe2(pipefds, O_CLOEXEC|O_NONBLOCK) < 0)
+                                return -errno;
+
+                        isz = fcntl(pipefds[1], F_GETPIPE_SZ, 0);
+                        if (isz < 0)
+                                return -errno;
+
+                        /* Try to enlarge the pipe size if necessary */
+                        if ((size_t) isz < DATA_FD_MEMORY_LIMIT) {
+
+                                (void) fcntl(pipefds[1], F_SETPIPE_SZ, DATA_FD_MEMORY_LIMIT);
+
+                                isz = fcntl(pipefds[1], F_GETPIPE_SZ, 0);
+                                if (isz < 0)
+                                        return -errno;
+                        }
+
+                        if ((size_t) isz >= DATA_FD_MEMORY_LIMIT) {
+
+                                r = copy_bytes_full(fd, pipefds[1], DATA_FD_MEMORY_LIMIT, 0, &remains, &remains_size, NULL, NULL);
+                                if (r < 0 && r != -EAGAIN)
+                                        return r; /* If we get EAGAIN it could be because of the source or because of
+                                                   * the destination fd, we can't know, as sendfile() and friends won't
+                                                   * tell us. Hence, treat this as reason to fall back, just to be
+                                                   * sure. */
+                                if (r == 0) {
+                                        /* Everything fit in, yay! */
+                                        (void) fd_nonblock(pipefds[0], false);
+
+                                        return TAKE_FD(pipefds[0]);
+                                }
+
+                                /* Things didn't fit in. But we read data into the pipe, let's remember that, so that
+                                 * when writing the new file we incorporate this first. */
+                                copy_fd = TAKE_FD(pipefds[0]);
+                        }
+                }
+        }
+
+        /* If we have reason to believe this will fit fine in /tmp, then use that as first fallback. */
+        if ((!S_ISREG(st.st_mode) || st.st_size < DATA_FD_TMP_LIMIT) &&
+            (DATA_FD_MEMORY_LIMIT + remains_size) < DATA_FD_TMP_LIMIT) {
+                off_t f;
+
+                tmp_fd = open_tmpfile_unlinkable(NULL /* NULL as directory means /tmp */, O_RDWR|O_CLOEXEC);
+                if (tmp_fd < 0)
+                        return tmp_fd;
+
+                if (copy_fd >= 0) {
+                        /* If we tried a memfd/pipe first and it ended up being too large, then copy this into the
+                         * temporary file first. */
+
+                        r = copy_bytes(copy_fd, tmp_fd, UINT64_MAX, 0);
+                        if (r < 0)
+                                return r;
+
+                        assert(r == 0);
+                }
+
+                if (remains_size > 0) {
+                        /* If there were remaining bytes (i.e. read into memory, but not written out yet) from the
+                         * failed copy operation, let's flush them out next. */
+
+                        r = loop_write(tmp_fd, remains, remains_size, false);
+                        if (r < 0)
+                                return r;
+                }
+
+                r = copy_bytes(fd, tmp_fd, DATA_FD_TMP_LIMIT - DATA_FD_MEMORY_LIMIT - remains_size, COPY_REFLINK);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        goto finish;  /* Yay, it fit in */
+
+                /* It didn't fit in. Let's not forget to use what we already used */
+                f = lseek(tmp_fd, 0, SEEK_SET);
+                if (f != 0)
+                        return -errno;
+
+                safe_close(copy_fd);
+                copy_fd = TAKE_FD(tmp_fd);
+
+                remains = mfree(remains);
+                remains_size = 0;
+        }
+
+        /* As last fallback use /var/tmp */
+        r = var_tmp_dir(&td);
+        if (r < 0)
+                return r;
+
+        tmp_fd = open_tmpfile_unlinkable(td, O_RDWR|O_CLOEXEC);
+        if (tmp_fd < 0)
+                return tmp_fd;
+
+        if (copy_fd >= 0) {
+                /* If we tried a memfd/pipe first, or a file in /tmp, and it ended up being too large, than copy this
+                 * into the temporary file first. */
+                r = copy_bytes(copy_fd, tmp_fd, UINT64_MAX, COPY_REFLINK);
+                if (r < 0)
+                        return r;
+
+                assert(r == 0);
+        }
+
+        if (remains_size > 0) {
+                /* Then, copy in any read but not yet written bytes. */
+                r = loop_write(tmp_fd, remains, remains_size, false);
+                if (r < 0)
+                        return r;
+        }
+
+        /* Copy in the rest */
+        r = copy_bytes(fd, tmp_fd, UINT64_MAX, COPY_REFLINK);
+        if (r < 0)
+                return r;
+
+        assert(r == 0);
+
+finish:
+        /* Now convert the O_RDWR file descriptor into an O_RDONLY one (and as side effect seek to the beginning of the
+         * file again */
+
+        return fd_reopen(tmp_fd, O_RDONLY|O_CLOEXEC);
+}
+
+int fd_move_above_stdio(int fd) {
+        int flags, copy;
+        PROTECT_ERRNO;
+
+        /* Moves the specified file descriptor if possible out of the range [0…2], i.e. the range of
+         * stdin/stdout/stderr. If it can't be moved outside of this range the original file descriptor is
+         * returned. This call is supposed to be used for long-lasting file descriptors we allocate in our code that
+         * might get loaded into foreign code, and where we want ensure our fds are unlikely used accidentally as
+         * stdin/stdout/stderr of unrelated code.
+         *
+         * Note that this doesn't fix any real bugs, it just makes it less likely that our code will be affected by
+         * buggy code from others that mindlessly invokes 'fprintf(stderr, …' or similar in places where stderr has
+         * been closed before.
+         *
+         * This function is written in a "best-effort" and "least-impact" style. This means whenever we encounter an
+         * error we simply return the original file descriptor, and we do not touch errno. */
+
+        if (fd < 0 || fd > 2)
+                return fd;
+
+        flags = fcntl(fd, F_GETFD, 0);
+        if (flags < 0)
+                return fd;
+
+        if (flags & FD_CLOEXEC)
+                copy = fcntl(fd, F_DUPFD_CLOEXEC, 3);
+        else
+                copy = fcntl(fd, F_DUPFD, 3);
+        if (copy < 0)
+                return fd;
+
+        assert(copy > 2);
+
+        (void) close(fd);
+        return copy;
+}
+
+int rearrange_stdio(int original_input_fd, int original_output_fd, int original_error_fd) {
+
+        int fd[3] = { /* Put together an array of fds we work on */
+                original_input_fd,
+                original_output_fd,
+                original_error_fd
+        };
+
+        int r, i,
+                null_fd = -1,                /* if we open /dev/null, we store the fd to it here */
+                copy_fd[3] = { -1, -1, -1 }; /* This contains all fds we duplicate here temporarily, and hence need to close at the end */
+        bool null_readable, null_writable;
+
+        /* Sets up stdin, stdout, stderr with the three file descriptors passed in. If any of the descriptors is
+         * specified as -1 it will be connected with /dev/null instead. If any of the file descriptors is passed as
+         * itself (e.g. stdin as STDIN_FILENO) it is left unmodified, but the O_CLOEXEC bit is turned off should it be
+         * on.
+         *
+         * Note that if any of the passed file descriptors are > 2 they will be closed — both on success and on
+         * failure! Thus, callers should assume that when this function returns the input fds are invalidated.
+         *
+         * Note that when this function fails stdin/stdout/stderr might remain half set up!
+         *
+         * O_CLOEXEC is turned off for all three file descriptors (which is how it should be for
+         * stdin/stdout/stderr). */
+
+        null_readable = original_input_fd < 0;
+        null_writable = original_output_fd < 0 || original_error_fd < 0;
+
+        /* First step, open /dev/null once, if we need it */
+        if (null_readable || null_writable) {
+
+                /* Let's open this with O_CLOEXEC first, and convert it to non-O_CLOEXEC when we move the fd to the final position. */
+                null_fd = open("/dev/null", (null_readable && null_writable ? O_RDWR :
+                                             null_readable ? O_RDONLY : O_WRONLY) | O_CLOEXEC);
+                if (null_fd < 0) {
+                        r = -errno;
+                        goto finish;
+                }
+
+                /* If this fd is in the 0…2 range, let's move it out of it */
+                if (null_fd < 3) {
+                        int copy;
+
+                        copy = fcntl(null_fd, F_DUPFD_CLOEXEC, 3); /* Duplicate this with O_CLOEXEC set */
+                        if (copy < 0) {
+                                r = -errno;
+                                goto finish;
+                        }
+
+                        safe_close(null_fd);
+                        null_fd = copy;
+                }
+        }
+
+        /* Let's assemble fd[] with the fds to install in place of stdin/stdout/stderr */
+        for (i = 0; i < 3; i++) {
+
+                if (fd[i] < 0)
+                        fd[i] = null_fd;        /* A negative parameter means: connect this one to /dev/null */
+                else if (fd[i] != i && fd[i] < 3) {
+                        /* This fd is in the 0…2 territory, but not at its intended place, move it out of there, so that we can work there. */
+                        copy_fd[i] = fcntl(fd[i], F_DUPFD_CLOEXEC, 3); /* Duplicate this with O_CLOEXEC set */
+                        if (copy_fd[i] < 0) {
+                                r = -errno;
+                                goto finish;
+                        }
+
+                        fd[i] = copy_fd[i];
+                }
+        }
+
+        /* At this point we now have the fds to use in fd[], and they are all above the stdio range, so that we
+         * have freedom to move them around. If the fds already were at the right places then the specific fds are
+         * -1. Let's now move them to the right places. This is the point of no return. */
+        for (i = 0; i < 3; i++) {
+
+                if (fd[i] == i) {
+
+                        /* fd is already in place, but let's make sure O_CLOEXEC is off */
+                        r = fd_cloexec(i, false);
+                        if (r < 0)
+                                goto finish;
+
+                } else {
+                        assert(fd[i] > 2);
+
+                        if (dup2(fd[i], i) < 0) { /* Turns off O_CLOEXEC on the new fd. */
+                                r = -errno;
+                                goto finish;
+                        }
+                }
+        }
+
+        r = 0;
+
+finish:
+        /* Close the original fds, but only if they were outside of the stdio range. Also, properly check for the same
+         * fd passed in multiple times. */
+        safe_close_above_stdio(original_input_fd);
+        if (original_output_fd != original_input_fd)
+                safe_close_above_stdio(original_output_fd);
+        if (original_error_fd != original_input_fd && original_error_fd != original_output_fd)
+                safe_close_above_stdio(original_error_fd);
+
+        /* Close the copies we moved > 2 */
+        for (i = 0; i < 3; i++)
+                safe_close(copy_fd[i]);
+
+        /* Close our null fd, if it's > 2 */
+        safe_close_above_stdio(null_fd);
+
+        return r;
+}
+
+int fd_reopen(int fd, int flags) {
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        int new_fd;
+
+        /* Reopens the specified fd with new flags. This is useful for convert an O_PATH fd into a regular one, or to
+         * turn O_RDWR fds into O_RDONLY fds.
+         *
+         * This doesn't work on sockets (since they cannot be open()ed, ever).
+         *
+         * This implicitly resets the file read index to 0. */
+
+        xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+        new_fd = open(procfs_path, flags);
+        if (new_fd < 0)
+                return -errno;
+
+        return new_fd;
+}
+
+int read_nr_open(void) {
+        _cleanup_free_ char *nr_open = NULL;
+        int r;
+
+        /* Returns the kernel's current fd limit, either by reading it of /proc/sys if that works, or using the
+         * hard-coded default compiled-in value of current kernels (1M) if not. This call will never fail. */
+
+        r = read_one_line_file("/proc/sys/fs/nr_open", &nr_open);
+        if (r < 0)
+                log_debug_errno(r, "Failed to read /proc/sys/fs/nr_open, ignoring: %m");
+        else {
+                int v;
+
+                r = safe_atoi(nr_open, &v);
+                if (r < 0)
+                        log_debug_errno(r, "Failed to parse /proc/sys/fs/nr_open value '%s', ignoring: %m", nr_open);
+                else
+                        return v;
+        }
+
+        /* If we fail, fallback to the hard-coded kernel limit of 1024 * 1024. */
+        return 1024 * 1024;
+}
diff --git a/src/basic/fd-util.h b/src/basic/fd-util.h
new file mode 100644
index 0000000..4085a24
--- /dev/null
+++ b/src/basic/fd-util.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <dirent.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/socket.h>
+
+#include "macro.h"
+
+/* Make sure we can distinguish fd 0 and NULL */
+#define FD_TO_PTR(fd) INT_TO_PTR((fd)+1)
+#define PTR_TO_FD(p) (PTR_TO_INT(p)-1)
+
+int close_nointr(int fd);
+int safe_close(int fd);
+void safe_close_pair(int p[static 2]);
+
+static inline int safe_close_above_stdio(int fd) {
+        if (fd < 3) /* Don't close stdin/stdout/stderr, but still invalidate the fd by returning -1 */
+                return -1;
+
+        return safe_close(fd);
+}
+
+void close_many(const int fds[], size_t n_fd);
+
+int fclose_nointr(FILE *f);
+FILE* safe_fclose(FILE *f);
+DIR* safe_closedir(DIR *f);
+
+static inline void closep(int *fd) {
+        safe_close(*fd);
+}
+
+static inline void close_pairp(int (*p)[2]) {
+        safe_close_pair(*p);
+}
+
+static inline void fclosep(FILE **f) {
+        safe_fclose(*f);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, pclose);
+DEFINE_TRIVIAL_CLEANUP_FUNC(DIR*, closedir);
+
+#define _cleanup_close_ _cleanup_(closep)
+#define _cleanup_fclose_ _cleanup_(fclosep)
+#define _cleanup_pclose_ _cleanup_(pclosep)
+#define _cleanup_closedir_ _cleanup_(closedirp)
+#define _cleanup_close_pair_ _cleanup_(close_pairp)
+
+int fd_nonblock(int fd, bool nonblock);
+int fd_cloexec(int fd, bool cloexec);
+
+int close_all_fds(const int except[], size_t n_except);
+
+int same_fd(int a, int b);
+
+void cmsg_close_all(struct msghdr *mh);
+
+bool fdname_is_valid(const char *s);
+
+int fd_get_path(int fd, char **ret);
+
+int move_fd(int from, int to, int cloexec);
+
+enum {
+        ACQUIRE_NO_DEV_NULL = 1 << 0,
+        ACQUIRE_NO_MEMFD    = 1 << 1,
+        ACQUIRE_NO_PIPE     = 1 << 2,
+        ACQUIRE_NO_TMPFILE  = 1 << 3,
+        ACQUIRE_NO_REGULAR  = 1 << 4,
+};
+
+int acquire_data_fd(const void *data, size_t size, unsigned flags);
+
+int fd_duplicate_data_fd(int fd);
+
+/* Hint: ENETUNREACH happens if we try to connect to "non-existing" special IP addresses, such as ::5 */
+/* The kernel sends e.g., EHOSTUNREACH or ENONET to userspace in some ICMP error cases.
+ * See the icmp_err_convert[] in net/ipv4/icmp.c in the kernel sources */
+#define ERRNO_IS_DISCONNECT(r)                                          \
+        IN_SET(r,                                                       \
+               ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE, \
+               ENETUNREACH, EHOSTUNREACH, ENOPROTOOPT, EHOSTDOWN, ENONET)
+
+/* Resource exhaustion, could be our fault or general system trouble */
+#define ERRNO_IS_RESOURCE(r) \
+        IN_SET(r, ENOMEM, EMFILE, ENFILE)
+
+int fd_move_above_stdio(int fd);
+
+int rearrange_stdio(int original_input_fd, int original_output_fd, int original_error_fd);
+
+static inline int make_null_stdio(void) {
+        return rearrange_stdio(-1, -1, -1);
+}
+
+/* Like TAKE_PTR() but for file descriptors, resetting them to -1 */
+#define TAKE_FD(fd)                             \
+        ({                                      \
+                int _fd_ = (fd);                \
+                (fd) = -1;                      \
+                _fd_;                           \
+        })
+
+int fd_reopen(int fd, int flags);
+
+int read_nr_open(void);
diff --git a/src/basic/fileio.c b/src/basic/fileio.c
new file mode 100644
index 0000000..e18b842
--- /dev/null
+++ b/src/basic/fileio.c
@@ -0,0 +1,822 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "tmpfile-util.h"
+
+#define READ_FULL_BYTES_MAX (4U*1024U*1024U)
+
+int write_string_stream_ts(
+                FILE *f,
+                const char *line,
+                WriteStringFileFlags flags,
+                struct timespec *ts) {
+
+        bool needs_nl;
+        int r;
+
+        assert(f);
+        assert(line);
+
+        if (ferror(f))
+                return -EIO;
+
+        needs_nl = !(flags & WRITE_STRING_FILE_AVOID_NEWLINE) && !endswith(line, "\n");
+
+        if (needs_nl && (flags & WRITE_STRING_FILE_DISABLE_BUFFER)) {
+                /* If STDIO buffering was disabled, then let's append the newline character to the string itself, so
+                 * that the write goes out in one go, instead of two */
+
+                line = strjoina(line, "\n");
+                needs_nl = false;
+        }
+
+        if (fputs(line, f) == EOF)
+                return -errno;
+
+        if (needs_nl)
+                if (fputc('\n', f) == EOF)
+                        return -errno;
+
+        if (flags & WRITE_STRING_FILE_SYNC)
+                r = fflush_sync_and_check(f);
+        else
+                r = fflush_and_check(f);
+        if (r < 0)
+                return r;
+
+        if (ts) {
+                struct timespec twice[2] = {*ts, *ts};
+
+                if (futimens(fileno(f), twice) < 0)
+                        return -errno;
+        }
+
+        return 0;
+}
+
+static int write_string_file_atomic(
+                const char *fn,
+                const char *line,
+                WriteStringFileFlags flags,
+                struct timespec *ts) {
+
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        assert(fn);
+        assert(line);
+
+        r = fopen_temporary(fn, &f, &p);
+        if (r < 0)
+                return r;
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+        (void) fchmod_umask(fileno(f), 0644);
+
+        r = write_string_stream_ts(f, line, flags, ts);
+        if (r < 0)
+                goto fail;
+
+        if (rename(p, fn) < 0) {
+                r = -errno;
+                goto fail;
+        }
+
+        return 0;
+
+fail:
+        (void) unlink(p);
+        return r;
+}
+
+int write_string_file_ts(
+                const char *fn,
+                const char *line,
+                WriteStringFileFlags flags,
+                struct timespec *ts) {
+
+        _cleanup_fclose_ FILE *f = NULL;
+        int q, r;
+
+        assert(fn);
+        assert(line);
+
+        /* We don't know how to verify whether the file contents was already on-disk. */
+        assert(!((flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE) && (flags & WRITE_STRING_FILE_SYNC)));
+
+        if (flags & WRITE_STRING_FILE_ATOMIC) {
+                assert(flags & WRITE_STRING_FILE_CREATE);
+
+                r = write_string_file_atomic(fn, line, flags, ts);
+                if (r < 0)
+                        goto fail;
+
+                return r;
+        } else
+                assert(!ts);
+
+        if (flags & WRITE_STRING_FILE_CREATE) {
+                f = fopen(fn, "we");
+                if (!f) {
+                        r = -errno;
+                        goto fail;
+                }
+        } else {
+                int fd;
+
+                /* We manually build our own version of fopen(..., "we") that
+                 * works without O_CREAT */
+                fd = open(fn, O_WRONLY|O_CLOEXEC|O_NOCTTY | ((flags & WRITE_STRING_FILE_NOFOLLOW) ? O_NOFOLLOW : 0));
+                if (fd < 0) {
+                        r = -errno;
+                        goto fail;
+                }
+
+                f = fdopen(fd, "w");
+                if (!f) {
+                        r = -errno;
+                        safe_close(fd);
+                        goto fail;
+                }
+        }
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        if (flags & WRITE_STRING_FILE_DISABLE_BUFFER)
+                setvbuf(f, NULL, _IONBF, 0);
+
+        r = write_string_stream_ts(f, line, flags, ts);
+        if (r < 0)
+                goto fail;
+
+        return 0;
+
+fail:
+        if (!(flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE))
+                return r;
+
+        f = safe_fclose(f);
+
+        /* OK, the operation failed, but let's see if the right
+         * contents in place already. If so, eat up the error. */
+
+        q = verify_file(fn, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE));
+        if (q <= 0)
+                return r;
+
+        return 0;
+}
+
+int write_string_filef(
+                const char *fn,
+                WriteStringFileFlags flags,
+                const char *format, ...) {
+
+        _cleanup_free_ char *p = NULL;
+        va_list ap;
+        int r;
+
+        va_start(ap, format);
+        r = vasprintf(&p, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return write_string_file(fn, p, flags);
+}
+
+int read_one_line_file(const char *fn, char **line) {
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        assert(fn);
+        assert(line);
+
+        f = fopen(fn, "re");
+        if (!f)
+                return -errno;
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        r = read_line(f, LONG_LINE_MAX, line);
+        return r < 0 ? r : 0;
+}
+
+int verify_file(const char *fn, const char *blob, bool accept_extra_nl) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *buf = NULL;
+        size_t l, k;
+
+        assert(fn);
+        assert(blob);
+
+        l = strlen(blob);
+
+        if (accept_extra_nl && endswith(blob, "\n"))
+                accept_extra_nl = false;
+
+        buf = malloc(l + accept_extra_nl + 1);
+        if (!buf)
+                return -ENOMEM;
+
+        f = fopen(fn, "re");
+        if (!f)
+                return -errno;
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        /* We try to read one byte more than we need, so that we know whether we hit eof */
+        errno = 0;
+        k = fread(buf, 1, l + accept_extra_nl + 1, f);
+        if (ferror(f))
+                return errno > 0 ? -errno : -EIO;
+
+        if (k != l && k != l + accept_extra_nl)
+                return 0;
+        if (memcmp(buf, blob, l) != 0)
+                return 0;
+        if (k > l && buf[l] != '\n')
+                return 0;
+
+        return 1;
+}
+
+int read_full_stream(
+                FILE *f,
+                char **ret_contents,
+                size_t *ret_size) {
+
+        _cleanup_free_ char *buf = NULL;
+        struct stat st;
+        size_t n, l;
+        int fd;
+
+        assert(f);
+        assert(ret_contents);
+
+        n = LINE_MAX; /* Start size */
+
+        fd = fileno(f);
+        if (fd >= 0) { /* If the FILE* object is backed by an fd (as opposed to memory or such, see fmemopen(), let's
+                        * optimize our buffering) */
+
+                if (fstat(fileno(f), &st) < 0)
+                        return -errno;
+
+                if (S_ISREG(st.st_mode)) {
+
+                        /* Safety check */
+                        if (st.st_size > READ_FULL_BYTES_MAX)
+                                return -E2BIG;
+
+                        /* Start with the right file size, but be prepared for files from /proc which generally report a file
+                         * size of 0. Note that we increase the size to read here by one, so that the first read attempt
+                         * already makes us notice the EOF. */
+                        if (st.st_size > 0)
+                                n = st.st_size + 1;
+                }
+        }
+
+        l = 0;
+        for (;;) {
+                char *t;
+                size_t k;
+
+                t = realloc(buf, n + 1);
+                if (!t)
+                        return -ENOMEM;
+
+                buf = t;
+                errno = 0;
+                k = fread(buf + l, 1, n - l, f);
+                if (k > 0)
+                        l += k;
+
+                if (ferror(f))
+                        return errno > 0 ? -errno : -EIO;
+
+                if (feof(f))
+                        break;
+
+                /* We aren't expecting fread() to return a short read outside
+                 * of (error && eof), assert buffer is full and enlarge buffer.
+                 */
+                assert(l == n);
+
+                /* Safety check */
+                if (n >= READ_FULL_BYTES_MAX)
+                        return -E2BIG;
+
+                n = MIN(n * 2, READ_FULL_BYTES_MAX);
+        }
+
+        if (!ret_size) {
+                /* Safety check: if the caller doesn't want to know the size of what we just read it will rely on the
+                 * trailing NUL byte. But if there's an embedded NUL byte, then we should refuse operation as otherwise
+                 * there'd be ambiguity about what we just read. */
+
+                if (memchr(buf, 0, l))
+                        return -EBADMSG;
+        }
+
+        buf[l] = 0;
+        *ret_contents = TAKE_PTR(buf);
+
+        if (ret_size)
+                *ret_size = l;
+
+        return 0;
+}
+
+int read_full_file(const char *fn, char **contents, size_t *size) {
+        _cleanup_fclose_ FILE *f = NULL;
+
+        assert(fn);
+        assert(contents);
+
+        f = fopen(fn, "re");
+        if (!f)
+                return -errno;
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        return read_full_stream(f, contents, size);
+}
+
+int executable_is_script(const char *path, char **interpreter) {
+        _cleanup_free_ char *line = NULL;
+        size_t len;
+        char *ans;
+        int r;
+
+        assert(path);
+
+        r = read_one_line_file(path, &line);
+        if (r == -ENOBUFS) /* First line overly long? if so, then it's not a script */
+                return 0;
+        if (r < 0)
+                return r;
+
+        if (!startswith(line, "#!"))
+                return 0;
+
+        ans = strstrip(line + 2);
+        len = strcspn(ans, " \t");
+
+        if (len == 0)
+                return 0;
+
+        ans = strndup(ans, len);
+        if (!ans)
+                return -ENOMEM;
+
+        *interpreter = ans;
+        return 1;
+}
+
+/**
+ * Retrieve one field from a file like /proc/self/status.  pattern
+ * should not include whitespace or the delimiter (':'). pattern matches only
+ * the beginning of a line. Whitespace before ':' is skipped. Whitespace and
+ * zeros after the ':' will be skipped. field must be freed afterwards.
+ * terminator specifies the terminating characters of the field value (not
+ * included in the value).
+ */
+int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field) {
+        _cleanup_free_ char *status = NULL;
+        char *t, *f;
+        size_t len;
+        int r;
+
+        assert(terminator);
+        assert(filename);
+        assert(pattern);
+        assert(field);
+
+        r = read_full_file(filename, &status, NULL);
+        if (r < 0)
+                return r;
+
+        t = status;
+
+        do {
+                bool pattern_ok;
+
+                do {
+                        t = strstr(t, pattern);
+                        if (!t)
+                                return -ENOENT;
+
+                        /* Check that pattern occurs in beginning of line. */
+                        pattern_ok = (t == status || t[-1] == '\n');
+
+                        t += strlen(pattern);
+
+                } while (!pattern_ok);
+
+                t += strspn(t, " \t");
+                if (!*t)
+                        return -ENOENT;
+
+        } while (*t != ':');
+
+        t++;
+
+        if (*t) {
+                t += strspn(t, " \t");
+
+                /* Also skip zeros, because when this is used for
+                 * capabilities, we don't want the zeros. This way the
+                 * same capability set always maps to the same string,
+                 * irrespective of the total capability set size. For
+                 * other numbers it shouldn't matter. */
+                t += strspn(t, "0");
+                /* Back off one char if there's nothing but whitespace
+                   and zeros */
+                if (!*t || isspace(*t))
+                        t--;
+        }
+
+        len = strcspn(t, terminator);
+
+        f = strndup(t, len);
+        if (!f)
+                return -ENOMEM;
+
+        *field = f;
+        return 0;
+}
+
+DIR *xopendirat(int fd, const char *name, int flags) {
+        int nfd;
+        DIR *d;
+
+        assert(!(flags & O_CREAT));
+
+        nfd = openat(fd, name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|flags, 0);
+        if (nfd < 0)
+                return NULL;
+
+        d = fdopendir(nfd);
+        if (!d) {
+                safe_close(nfd);
+                return NULL;
+        }
+
+        return d;
+}
+
+static int search_and_fopen_internal(const char *path, const char *mode, const char *root, char **search, FILE **_f) {
+        char **i;
+
+        assert(path);
+        assert(mode);
+        assert(_f);
+
+        if (!path_strv_resolve_uniq(search, root))
+                return -ENOMEM;
+
+        STRV_FOREACH(i, search) {
+                _cleanup_free_ char *p = NULL;
+                FILE *f;
+
+                if (root)
+                        p = strjoin(root, *i, "/", path);
+                else
+                        p = strjoin(*i, "/", path);
+                if (!p)
+                        return -ENOMEM;
+
+                f = fopen(p, mode);
+                if (f) {
+                        *_f = f;
+                        return 0;
+                }
+
+                if (errno != ENOENT)
+                        return -errno;
+        }
+
+        return -ENOENT;
+}
+
+int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **_f) {
+        _cleanup_strv_free_ char **copy = NULL;
+
+        assert(path);
+        assert(mode);
+        assert(_f);
+
+        if (path_is_absolute(path)) {
+                FILE *f;
+
+                f = fopen(path, mode);
+                if (f) {
+                        *_f = f;
+                        return 0;
+                }
+
+                return -errno;
+        }
+
+        copy = strv_copy((char**) search);
+        if (!copy)
+                return -ENOMEM;
+
+        return search_and_fopen_internal(path, mode, root, copy, _f);
+}
+
+int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **_f) {
+        _cleanup_strv_free_ char **s = NULL;
+
+        if (path_is_absolute(path)) {
+                FILE *f;
+
+                f = fopen(path, mode);
+                if (f) {
+                        *_f = f;
+                        return 0;
+                }
+
+                return -errno;
+        }
+
+        s = strv_split_nulstr(search);
+        if (!s)
+                return -ENOMEM;
+
+        return search_and_fopen_internal(path, mode, root, s, _f);
+}
+
+int fflush_and_check(FILE *f) {
+        assert(f);
+
+        errno = 0;
+        fflush(f);
+
+        if (ferror(f))
+                return errno > 0 ? -errno : -EIO;
+
+        return 0;
+}
+
+int fflush_sync_and_check(FILE *f) {
+        int r;
+
+        assert(f);
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return r;
+
+        if (fsync(fileno(f)) < 0)
+                return -errno;
+
+        r = fsync_directory_of_file(fileno(f));
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int write_timestamp_file_atomic(const char *fn, usec_t n) {
+        char ln[DECIMAL_STR_MAX(n)+2];
+
+        /* Creates a "timestamp" file, that contains nothing but a
+         * usec_t timestamp, formatted in ASCII. */
+
+        if (n <= 0 || n >= USEC_INFINITY)
+                return -ERANGE;
+
+        xsprintf(ln, USEC_FMT "\n", n);
+
+        return write_string_file(fn, ln, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
+}
+
+int read_timestamp_file(const char *fn, usec_t *ret) {
+        _cleanup_free_ char *ln = NULL;
+        uint64_t t;
+        int r;
+
+        r = read_one_line_file(fn, &ln);
+        if (r < 0)
+                return r;
+
+        r = safe_atou64(ln, &t);
+        if (r < 0)
+                return r;
+
+        if (t <= 0 || t >= (uint64_t) USEC_INFINITY)
+                return -ERANGE;
+
+        *ret = (usec_t) t;
+        return 0;
+}
+
+int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space) {
+        int r;
+
+        assert(s);
+
+        /* Outputs the specified string with fputs(), but optionally prefixes it with a separator. The *space parameter
+         * when specified shall initially point to a boolean variable initialized to false. It is set to true after the
+         * first invocation. This call is supposed to be use in loops, where a separator shall be inserted between each
+         * element, but not before the first one. */
+
+        if (!f)
+                f = stdout;
+
+        if (space) {
+                if (!separator)
+                        separator = " ";
+
+                if (*space) {
+                        r = fputs(separator, f);
+                        if (r < 0)
+                                return r;
+                }
+
+                *space = true;
+        }
+
+        return fputs(s, f);
+}
+
+/* A bitmask of the EOL markers we know */
+typedef enum EndOfLineMarker {
+        EOL_NONE     = 0,
+        EOL_ZERO     = 1 << 0,  /* \0 (aka NUL) */
+        EOL_TEN      = 1 << 1,  /* \n (aka NL, aka LF)  */
+        EOL_THIRTEEN = 1 << 2,  /* \r (aka CR)  */
+} EndOfLineMarker;
+
+static EndOfLineMarker categorize_eol(char c, ReadLineFlags flags) {
+
+        if (!IN_SET(flags, READ_LINE_ONLY_NUL)) {
+                if (c == '\n')
+                        return EOL_TEN;
+                if (c == '\r')
+                        return EOL_THIRTEEN;
+        }
+
+        if (c == '\0')
+                return EOL_ZERO;
+
+        return EOL_NONE;
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, funlockfile);
+
+int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret) {
+        size_t n = 0, allocated = 0, count = 0;
+        _cleanup_free_ char *buffer = NULL;
+        int r;
+
+        assert(f);
+
+        /* Something like a bounded version of getline().
+         *
+         * Considers EOF, \n, \r and \0 end of line delimiters (or combinations of these), and does not include these
+         * delimiters in the string returned. Specifically, recognizes the following combinations of markers as line
+         * endings:
+         *
+         *     • \n        (UNIX)
+         *     • \r        (old MacOS)
+         *     • \0        (C strings)
+         *     • \n\0
+         *     • \r\0
+         *     • \r\n      (Windows)
+         *     • \n\r
+         *     • \r\n\0
+         *     • \n\r\0
+         *
+         * Returns the number of bytes read from the files (i.e. including delimiters — this hence usually differs from
+         * the number of characters in the returned string). When EOF is hit, 0 is returned.
+         *
+         * The input parameter limit is the maximum numbers of characters in the returned string, i.e. excluding
+         * delimiters. If the limit is hit we fail and return -ENOBUFS.
+         *
+         * If a line shall be skipped ret may be initialized as NULL. */
+
+        if (ret) {
+                if (!GREEDY_REALLOC(buffer, allocated, 1))
+                        return -ENOMEM;
+        }
+
+        {
+                _unused_ _cleanup_(funlockfilep) FILE *flocked = f;
+                EndOfLineMarker previous_eol = EOL_NONE;
+                flockfile(f);
+
+                for (;;) {
+                        EndOfLineMarker eol;
+                        char c;
+
+                        if (n >= limit)
+                                return -ENOBUFS;
+
+                        if (count >= INT_MAX) /* We couldn't return the counter anymore as "int", hence refuse this */
+                                return -ENOBUFS;
+
+                        r = safe_fgetc(f, &c);
+                        if (r < 0)
+                                return r;
+                        if (r == 0) /* EOF is definitely EOL */
+                                break;
+
+                        eol = categorize_eol(c, flags);
+
+                        if (FLAGS_SET(previous_eol, EOL_ZERO) ||
+                            (eol == EOL_NONE && previous_eol != EOL_NONE) ||
+                            (eol != EOL_NONE && (previous_eol & eol) != 0)) {
+                                /* Previous char was a NUL? This is not an EOL, but the previous char was? This type of
+                                 * EOL marker has been seen right before?  In either of these three cases we are
+                                 * done. But first, let's put this character back in the queue. (Note that we have to
+                                 * cast this to (unsigned char) here as ungetc() expects a positive 'int', and if we
+                                 * are on an architecture where 'char' equals 'signed char' we need to ensure we don't
+                                 * pass a negative value here. That said, to complicate things further ungetc() is
+                                 * actually happy with most negative characters and implicitly casts them back to
+                                 * positive ones as needed, except for \xff (aka -1, aka EOF), which it refuses. What a
+                                 * godawful API!) */
+                                assert_se(ungetc((unsigned char) c, f) != EOF);
+                                break;
+                        }
+
+                        count++;
+
+                        if (eol != EOL_NONE) {
+                                previous_eol |= eol;
+                                continue;
+                        }
+
+                        if (ret) {
+                                if (!GREEDY_REALLOC(buffer, allocated, n + 2))
+                                        return -ENOMEM;
+
+                                buffer[n] = c;
+                        }
+
+                        n++;
+                }
+        }
+
+        if (ret) {
+                buffer[n] = 0;
+
+                *ret = TAKE_PTR(buffer);
+        }
+
+        return (int) count;
+}
+
+int safe_fgetc(FILE *f, char *ret) {
+        int k;
+
+        assert(f);
+
+        /* A safer version of plain fgetc(): let's propagate the error that happened while reading as such, and
+         * separate the EOF condition from the byte read, to avoid those confusion signed/unsigned issues fgetc()
+         * has. */
+
+        errno = 0;
+        k = fgetc(f);
+        if (k == EOF) {
+                if (ferror(f))
+                        return errno > 0 ? -errno : -EIO;
+
+                if (ret)
+                        *ret = 0;
+
+                return 0;
+        }
+
+        if (ret)
+                *ret = k;
+
+        return 1;
+}
diff --git a/src/basic/fileio.h b/src/basic/fileio.h
new file mode 100644
index 0000000..53e3f4e
--- /dev/null
+++ b/src/basic/fileio.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <dirent.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "macro.h"
+#include "time-util.h"
+
+#define LONG_LINE_MAX (1U*1024U*1024U)
+
+typedef enum {
+        WRITE_STRING_FILE_CREATE            = 1 << 0,
+        WRITE_STRING_FILE_ATOMIC            = 1 << 1,
+        WRITE_STRING_FILE_AVOID_NEWLINE     = 1 << 2,
+        WRITE_STRING_FILE_VERIFY_ON_FAILURE = 1 << 3,
+        WRITE_STRING_FILE_SYNC              = 1 << 4,
+        WRITE_STRING_FILE_DISABLE_BUFFER    = 1 << 5,
+        WRITE_STRING_FILE_NOFOLLOW          = 1 << 6,
+
+        /* And before you wonder, why write_string_file_atomic_label_ts() is a separate function instead of just one
+           more flag here: it's about linking: we don't want to pull -lselinux into all users of write_string_file()
+           and friends. */
+
+} WriteStringFileFlags;
+
+int write_string_stream_ts(FILE *f, const char *line, WriteStringFileFlags flags, struct timespec *ts);
+static inline int write_string_stream(FILE *f, const char *line, WriteStringFileFlags flags) {
+        return write_string_stream_ts(f, line, flags, NULL);
+}
+int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, struct timespec *ts);
+static inline int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
+        return write_string_file_ts(fn, line, flags, NULL);
+}
+
+int write_string_filef(const char *fn, WriteStringFileFlags flags, const char *format, ...) _printf_(3, 4);
+
+int read_one_line_file(const char *fn, char **line);
+int read_full_file(const char *fn, char **contents, size_t *size);
+int read_full_stream(FILE *f, char **contents, size_t *size);
+
+int verify_file(const char *fn, const char *blob, bool accept_extra_nl);
+
+int executable_is_script(const char *path, char **interpreter);
+
+int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field);
+
+DIR *xopendirat(int dirfd, const char *name, int flags);
+
+int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **_f);
+int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **_f);
+
+int fflush_and_check(FILE *f);
+int fflush_sync_and_check(FILE *f);
+
+int write_timestamp_file_atomic(const char *fn, usec_t n);
+int read_timestamp_file(const char *fn, usec_t *ret);
+
+int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space);
+
+typedef enum ReadLineFlags {
+        READ_LINE_ONLY_NUL = 1 << 0,
+} ReadLineFlags;
+
+int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret);
+
+static inline int read_line(FILE *f, size_t limit, char **ret) {
+        return read_line_full(f, limit, 0, ret);
+}
+
+static inline int read_nul_string(FILE *f, size_t limit, char **ret) {
+        return read_line_full(f, limit, READ_LINE_ONLY_NUL, ret);
+}
+
+int safe_fgetc(FILE *f, char *ret);
diff --git a/src/basic/format-util.h b/src/basic/format-util.h
new file mode 100644
index 0000000..dece5d3
--- /dev/null
+++ b/src/basic/format-util.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+
+#if SIZEOF_PID_T == 4
+#  define PID_PRI PRIi32
+#elif SIZEOF_PID_T == 2
+#  define PID_PRI PRIi16
+#else
+#  error Unknown pid_t size
+#endif
+#define PID_FMT "%" PID_PRI
+
+#if SIZEOF_UID_T == 4
+#  define UID_FMT "%" PRIu32
+#elif SIZEOF_UID_T == 2
+#  define UID_FMT "%" PRIu16
+#else
+#  error Unknown uid_t size
+#endif
+
+#if SIZEOF_GID_T == 4
+#  define GID_FMT "%" PRIu32
+#elif SIZEOF_GID_T == 2
+#  define GID_FMT "%" PRIu16
+#else
+#  error Unknown gid_t size
+#endif
+
+#if SIZEOF_TIME_T == 8
+#  define PRI_TIME PRIi64
+#elif SIZEOF_TIME_T == 4
+#  define PRI_TIME "li"
+#else
+#  error Unknown time_t size
+#endif
+
+#if defined __x86_64__ && defined __ILP32__
+#  define PRI_TIMEX PRIi64
+#else
+#  define PRI_TIMEX "li"
+#endif
+
+#if SIZEOF_RLIM_T == 8
+#  define RLIM_FMT "%" PRIu64
+#elif SIZEOF_RLIM_T == 4
+#  define RLIM_FMT "%" PRIu32
+#else
+#  error Unknown rlim_t size
+#endif
+
+#if SIZEOF_DEV_T == 8
+#  define DEV_FMT "%" PRIu64
+#elif SIZEOF_DEV_T == 4
+#  define DEV_FMT "%" PRIu32
+#else
+#  error Unknown dev_t size
+#endif
+
+#if SIZEOF_INO_T == 8
+#  define INO_FMT "%" PRIu64
+#elif SIZEOF_INO_T == 4
+#  define INO_FMT "%" PRIu32
+#else
+#  error Unknown ino_t size
+#endif
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
new file mode 100644
index 0000000..f25bf2c
--- /dev/null
+++ b/src/basic/fs-util.c
@@ -0,0 +1,1358 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <linux/magic.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "locale-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "mkdir.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "tmpfile-util.h"
+#include "user-util.h"
+#include "util.h"
+
+int unlink_noerrno(const char *path) {
+        PROTECT_ERRNO;
+        int r;
+
+        r = unlink(path);
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+int rmdir_parents(const char *path, const char *stop) {
+        size_t l;
+        int r = 0;
+
+        assert(path);
+        assert(stop);
+
+        l = strlen(path);
+
+        /* Skip trailing slashes */
+        while (l > 0 && path[l-1] == '/')
+                l--;
+
+        while (l > 0) {
+                char *t;
+
+                /* Skip last component */
+                while (l > 0 && path[l-1] != '/')
+                        l--;
+
+                /* Skip trailing slashes */
+                while (l > 0 && path[l-1] == '/')
+                        l--;
+
+                if (l <= 0)
+                        break;
+
+                t = strndup(path, l);
+                if (!t)
+                        return -ENOMEM;
+
+                if (path_startswith(stop, t)) {
+                        free(t);
+                        return 0;
+                }
+
+                r = rmdir(t);
+                free(t);
+
+                if (r < 0)
+                        if (errno != ENOENT)
+                                return -errno;
+        }
+
+        return 0;
+}
+
+int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) {
+        int r;
+
+        /* Try the ideal approach first */
+        if (renameat2(olddirfd, oldpath, newdirfd, newpath, RENAME_NOREPLACE) >= 0)
+                return 0;
+
+        /* renameat2() exists since Linux 3.15, btrfs and FAT added support for it later. If it is not implemented,
+         * fall back to a different method. */
+        if (!IN_SET(errno, EINVAL, ENOSYS, ENOTTY))
+                return -errno;
+
+        /* Let's try to use linkat()+unlinkat() as fallback. This doesn't work on directories and on some file systems
+         * that do not support hard links (such as FAT, most prominently), but for files it's pretty close to what we
+         * want — though not atomic (i.e. for a short period both the new and the old filename will exist). */
+        if (linkat(olddirfd, oldpath, newdirfd, newpath, 0) >= 0) {
+
+                if (unlinkat(olddirfd, oldpath, 0) < 0) {
+                        r = -errno; /* Backup errno before the following unlinkat() alters it */
+                        (void) unlinkat(newdirfd, newpath, 0);
+                        return r;
+                }
+
+                return 0;
+        }
+
+        if (!IN_SET(errno, EINVAL, ENOSYS, ENOTTY, EPERM)) /* FAT returns EPERM on link()… */
+                return -errno;
+
+        /* OK, neither RENAME_NOREPLACE nor linkat()+unlinkat() worked. Let's then fallback to the racy TOCTOU
+         * vulnerable accessat(F_OK) check followed by classic, replacing renameat(), we have nothing better. */
+
+        if (faccessat(newdirfd, newpath, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
+                return -EEXIST;
+        if (errno != ENOENT)
+                return -errno;
+
+        if (renameat(olddirfd, oldpath, newdirfd, newpath) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int readlinkat_malloc(int fd, const char *p, char **ret) {
+        size_t l = FILENAME_MAX+1;
+        int r;
+
+        assert(p);
+        assert(ret);
+
+        for (;;) {
+                char *c;
+                ssize_t n;
+
+                c = new(char, l);
+                if (!c)
+                        return -ENOMEM;
+
+                n = readlinkat(fd, p, c, l-1);
+                if (n < 0) {
+                        r = -errno;
+                        free(c);
+                        return r;
+                }
+
+                if ((size_t) n < l-1) {
+                        c[n] = 0;
+                        *ret = c;
+                        return 0;
+                }
+
+                free(c);
+                l *= 2;
+        }
+}
+
+int readlink_malloc(const char *p, char **ret) {
+        return readlinkat_malloc(AT_FDCWD, p, ret);
+}
+
+int readlink_value(const char *p, char **ret) {
+        _cleanup_free_ char *link = NULL;
+        char *value;
+        int r;
+
+        r = readlink_malloc(p, &link);
+        if (r < 0)
+                return r;
+
+        value = basename(link);
+        if (!value)
+                return -ENOENT;
+
+        value = strdup(value);
+        if (!value)
+                return -ENOMEM;
+
+        *ret = value;
+
+        return 0;
+}
+
+int readlink_and_make_absolute(const char *p, char **r) {
+        _cleanup_free_ char *target = NULL;
+        char *k;
+        int j;
+
+        assert(p);
+        assert(r);
+
+        j = readlink_malloc(p, &target);
+        if (j < 0)
+                return j;
+
+        k = file_in_same_dir(p, target);
+        if (!k)
+                return -ENOMEM;
+
+        *r = k;
+        return 0;
+}
+
+int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
+        char fd_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
+        _cleanup_close_ int fd = -1;
+        assert(path);
+
+        /* Under the assumption that we are running privileged we first change the access mode and only then hand out
+         * ownership to avoid a window where access is too open. */
+
+        fd = open(path, O_PATH|O_CLOEXEC|O_NOFOLLOW); /* Let's acquire an O_PATH fd, as precaution to change mode/owner
+                                                       * on the same file */
+        if (fd < 0)
+                return -errno;
+
+        xsprintf(fd_path, "/proc/self/fd/%i", fd);
+
+        if (mode != MODE_INVALID) {
+
+                if ((mode & S_IFMT) != 0) {
+                        struct stat st;
+
+                        if (stat(fd_path, &st) < 0)
+                                return -errno;
+
+                        if ((mode & S_IFMT) != (st.st_mode & S_IFMT))
+                                return -EINVAL;
+                }
+
+                if (chmod(fd_path, mode & 07777) < 0)
+                        return -errno;
+        }
+
+        if (uid != UID_INVALID || gid != GID_INVALID)
+                if (chown(fd_path, uid, gid) < 0)
+                        return -errno;
+
+        return 0;
+}
+
+int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid) {
+        /* Under the assumption that we are running privileged we first change the access mode and only then hand out
+         * ownership to avoid a window where access is too open. */
+
+        if (mode != MODE_INVALID) {
+
+                if ((mode & S_IFMT) != 0) {
+                        struct stat st;
+
+                        if (fstat(fd, &st) < 0)
+                                return -errno;
+
+                        if ((mode & S_IFMT) != (st.st_mode & S_IFMT))
+                                return -EINVAL;
+                }
+
+                if (fchmod(fd, mode & 0777) < 0)
+                        return -errno;
+        }
+
+        if (uid != UID_INVALID || gid != GID_INVALID)
+                if (fchown(fd, uid, gid) < 0)
+                        return -errno;
+
+        return 0;
+}
+
+int fchmod_umask(int fd, mode_t m) {
+        mode_t u;
+        int r;
+
+        u = umask(0777);
+        r = fchmod(fd, m & (~u)) < 0 ? -errno : 0;
+        umask(u);
+
+        return r;
+}
+
+int fchmod_opath(int fd, mode_t m) {
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+
+        /* This function operates also on fd that might have been opened with
+         * O_PATH. Indeed fchmodat() doesn't have the AT_EMPTY_PATH flag like
+         * fchownat() does. */
+
+        xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+        if (chmod(procfs_path, m) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int fd_warn_permissions(const char *path, int fd) {
+        struct stat st;
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (st.st_mode & 0111)
+                log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path);
+
+        if (st.st_mode & 0002)
+                log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path);
+
+        if (getpid_cached() == 1 && (st.st_mode & 0044) != 0044)
+                log_warning("Configuration file %s is marked world-inaccessible. This has no effect as configuration data is accessible via APIs without restrictions. Proceeding anyway.", path);
+
+        return 0;
+}
+
+int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) {
+        char fdpath[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        _cleanup_close_ int fd = -1;
+        int r, ret = 0;
+
+        assert(path);
+
+        /* Note that touch_file() does not follow symlinks: if invoked on an existing symlink, then it is the symlink
+         * itself which is updated, not its target
+         *
+         * Returns the first error we encounter, but tries to apply as much as possible. */
+
+        if (parents)
+                (void) mkdir_parents(path, 0755);
+
+        /* Initially, we try to open the node with O_PATH, so that we get a reference to the node. This is useful in
+         * case the path refers to an existing device or socket node, as we can open it successfully in all cases, and
+         * won't trigger any driver magic or so. */
+        fd = open(path, O_PATH|O_CLOEXEC|O_NOFOLLOW);
+        if (fd < 0) {
+                if (errno != ENOENT)
+                        return -errno;
+
+                /* if the node doesn't exist yet, we create it, but with O_EXCL, so that we only create a regular file
+                 * here, and nothing else */
+                fd = open(path, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, IN_SET(mode, 0, MODE_INVALID) ? 0644 : mode);
+                if (fd < 0)
+                        return -errno;
+        }
+
+        /* Let's make a path from the fd, and operate on that. With this logic, we can adjust the access mode,
+         * ownership and time of the file node in all cases, even if the fd refers to an O_PATH object — which is
+         * something fchown(), fchmod(), futimensat() don't allow. */
+        xsprintf(fdpath, "/proc/self/fd/%i", fd);
+
+        if (mode != MODE_INVALID)
+                if (chmod(fdpath, mode) < 0)
+                        ret = -errno;
+
+        if (uid_is_valid(uid) || gid_is_valid(gid))
+                if (chown(fdpath, uid, gid) < 0 && ret >= 0)
+                        ret = -errno;
+
+        if (stamp != USEC_INFINITY) {
+                struct timespec ts[2];
+
+                timespec_store(&ts[0], stamp);
+                ts[1] = ts[0];
+                r = utimensat(AT_FDCWD, fdpath, ts, 0);
+        } else
+                r = utimensat(AT_FDCWD, fdpath, NULL, 0);
+        if (r < 0 && ret >= 0)
+                return -errno;
+
+        return ret;
+}
+
+int touch(const char *path) {
+        return touch_file(path, false, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
+}
+
+int symlink_idempotent(const char *from, const char *to, bool make_relative) {
+        _cleanup_free_ char *relpath = NULL;
+        int r;
+
+        assert(from);
+        assert(to);
+
+        if (make_relative) {
+                _cleanup_free_ char *parent = NULL;
+
+                parent = dirname_malloc(to);
+                if (!parent)
+                        return -ENOMEM;
+
+                r = path_make_relative(parent, from, &relpath);
+                if (r < 0)
+                        return r;
+
+                from = relpath;
+        }
+
+        if (symlink(from, to) < 0) {
+                _cleanup_free_ char *p = NULL;
+
+                if (errno != EEXIST)
+                        return -errno;
+
+                r = readlink_malloc(to, &p);
+                if (r == -EINVAL) /* Not a symlink? In that case return the original error we encountered: -EEXIST */
+                        return -EEXIST;
+                if (r < 0) /* Any other error? In that case propagate it as is */
+                        return r;
+
+                if (!streq(p, from)) /* Not the symlink we want it to be? In that case, propagate the original -EEXIST */
+                        return -EEXIST;
+        }
+
+        return 0;
+}
+
+int symlink_atomic(const char *from, const char *to) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        assert(from);
+        assert(to);
+
+        r = tempfn_random(to, NULL, &t);
+        if (r < 0)
+                return r;
+
+        if (symlink(from, t) < 0)
+                return -errno;
+
+        if (rename(t, to) < 0) {
+                unlink_noerrno(t);
+                return -errno;
+        }
+
+        return 0;
+}
+
+int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        assert(path);
+
+        r = tempfn_random(path, NULL, &t);
+        if (r < 0)
+                return r;
+
+        if (mknod(t, mode, dev) < 0)
+                return -errno;
+
+        if (rename(t, path) < 0) {
+                unlink_noerrno(t);
+                return -errno;
+        }
+
+        return 0;
+}
+
+int mkfifo_atomic(const char *path, mode_t mode) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        assert(path);
+
+        r = tempfn_random(path, NULL, &t);
+        if (r < 0)
+                return r;
+
+        if (mkfifo(t, mode) < 0)
+                return -errno;
+
+        if (rename(t, path) < 0) {
+                unlink_noerrno(t);
+                return -errno;
+        }
+
+        return 0;
+}
+
+int mkfifoat_atomic(int dirfd, const char *path, mode_t mode) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        assert(path);
+
+        if (path_is_absolute(path))
+                return mkfifo_atomic(path, mode);
+
+        /* We're only interested in the (random) filename.  */
+        r = tempfn_random_child("", NULL, &t);
+        if (r < 0)
+                return r;
+
+        if (mkfifoat(dirfd, t, mode) < 0)
+                return -errno;
+
+        if (renameat(dirfd, t, dirfd, path) < 0) {
+                unlink_noerrno(t);
+                return -errno;
+        }
+
+        return 0;
+}
+
+int get_files_in_directory(const char *path, char ***list) {
+        _cleanup_closedir_ DIR *d = NULL;
+        struct dirent *de;
+        size_t bufsize = 0, n = 0;
+        _cleanup_strv_free_ char **l = NULL;
+
+        assert(path);
+
+        /* Returns all files in a directory in *list, and the number
+         * of files as return value. If list is NULL returns only the
+         * number. */
+
+        d = opendir(path);
+        if (!d)
+                return -errno;
+
+        FOREACH_DIRENT_ALL(de, d, return -errno) {
+                dirent_ensure_type(d, de);
+
+                if (!dirent_is_file(de))
+                        continue;
+
+                if (list) {
+                        /* one extra slot is needed for the terminating NULL */
+                        if (!GREEDY_REALLOC(l, bufsize, n + 2))
+                                return -ENOMEM;
+
+                        l[n] = strdup(de->d_name);
+                        if (!l[n])
+                                return -ENOMEM;
+
+                        l[++n] = NULL;
+                } else
+                        n++;
+        }
+
+        if (list)
+                *list = TAKE_PTR(l);
+
+        return n;
+}
+
+static int getenv_tmp_dir(const char **ret_path) {
+        const char *n;
+        int r, ret = 0;
+
+        assert(ret_path);
+
+        /* We use the same order of environment variables python uses in tempfile.gettempdir():
+         * https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir */
+        FOREACH_STRING(n, "TMPDIR", "TEMP", "TMP") {
+                const char *e;
+
+                e = secure_getenv(n);
+                if (!e)
+                        continue;
+                if (!path_is_absolute(e)) {
+                        r = -ENOTDIR;
+                        goto next;
+                }
+                if (!path_is_normalized(e)) {
+                        r = -EPERM;
+                        goto next;
+                }
+
+                r = is_dir(e, true);
+                if (r < 0)
+                        goto next;
+                if (r == 0) {
+                        r = -ENOTDIR;
+                        goto next;
+                }
+
+                *ret_path = e;
+                return 1;
+
+        next:
+                /* Remember first error, to make this more debuggable */
+                if (ret >= 0)
+                        ret = r;
+        }
+
+        if (ret < 0)
+                return ret;
+
+        *ret_path = NULL;
+        return ret;
+}
+
+static int tmp_dir_internal(const char *def, const char **ret) {
+        const char *e;
+        int r, k;
+
+        assert(def);
+        assert(ret);
+
+        r = getenv_tmp_dir(&e);
+        if (r > 0) {
+                *ret = e;
+                return 0;
+        }
+
+        k = is_dir(def, true);
+        if (k == 0)
+                k = -ENOTDIR;
+        if (k < 0)
+                return r < 0 ? r : k;
+
+        *ret = def;
+        return 0;
+}
+
+int var_tmp_dir(const char **ret) {
+
+        /* Returns the location for "larger" temporary files, that is backed by physical storage if available, and thus
+         * even might survive a boot: /var/tmp. If $TMPDIR (or related environment variables) are set, its value is
+         * returned preferably however. Note that both this function and tmp_dir() below are affected by $TMPDIR,
+         * making it a variable that overrides all temporary file storage locations. */
+
+        return tmp_dir_internal("/var/tmp", ret);
+}
+
+int tmp_dir(const char **ret) {
+
+        /* Similar to var_tmp_dir() above, but returns the location for "smaller" temporary files, which is usually
+         * backed by an in-memory file system: /tmp. */
+
+        return tmp_dir_internal("/tmp", ret);
+}
+
+int unlink_or_warn(const char *filename) {
+        if (unlink(filename) < 0 && errno != ENOENT)
+                /* If the file doesn't exist and the fs simply was read-only (in which
+                 * case unlink() returns EROFS even if the file doesn't exist), don't
+                 * complain */
+                if (errno != EROFS || access(filename, F_OK) >= 0)
+                        return log_error_errno(errno, "Failed to remove \"%s\": %m", filename);
+
+        return 0;
+}
+
+int inotify_add_watch_fd(int fd, int what, uint32_t mask) {
+        char path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
+        int r;
+
+        /* This is like inotify_add_watch(), except that the file to watch is not referenced by a path, but by an fd */
+        xsprintf(path, "/proc/self/fd/%i", what);
+
+        r = inotify_add_watch(fd, path, mask);
+        if (r < 0)
+                return -errno;
+
+        return r;
+}
+
+static bool unsafe_transition(const struct stat *a, const struct stat *b) {
+        /* Returns true if the transition from a to b is safe, i.e. that we never transition from unprivileged to
+         * privileged files or directories. Why bother? So that unprivileged code can't symlink to privileged files
+         * making us believe we read something safe even though it isn't safe in the specific context we open it in. */
+
+        if (a->st_uid == 0) /* Transitioning from privileged to unprivileged is always fine */
+                return false;
+
+        return a->st_uid != b->st_uid; /* Otherwise we need to stay within the same UID */
+}
+
+static int log_unsafe_transition(int a, int b, const char *path, unsigned flags) {
+        _cleanup_free_ char *n1 = NULL, *n2 = NULL;
+
+        if (!FLAGS_SET(flags, CHASE_WARN))
+                return -ENOLINK;
+
+        (void) fd_get_path(a, &n1);
+        (void) fd_get_path(b, &n2);
+
+        return log_warning_errno(SYNTHETIC_ERRNO(ENOLINK),
+                                 "Detected unsafe path transition %s %s %s during canonicalization of %s.",
+                                 n1, special_glyph(SPECIAL_GLYPH_ARROW), n2, path);
+}
+
+static int log_autofs_mount_point(int fd, const char *path, unsigned flags) {
+        _cleanup_free_ char *n1 = NULL;
+
+        if (!FLAGS_SET(flags, CHASE_WARN))
+                return -EREMOTE;
+
+        (void) fd_get_path(fd, &n1);
+
+        return log_warning_errno(SYNTHETIC_ERRNO(EREMOTE),
+                                 "Detected autofs mount point %s during canonicalization of %s.",
+                                 n1, path);
+}
+
+int chase_symlinks(const char *path, const char *original_root, unsigned flags, char **ret) {
+        _cleanup_free_ char *buffer = NULL, *done = NULL, *root = NULL;
+        _cleanup_close_ int fd = -1;
+        unsigned max_follow = CHASE_SYMLINKS_MAX; /* how many symlinks to follow before giving up and returning ELOOP */
+        struct stat previous_stat;
+        bool exists = true;
+        char *todo;
+        int r;
+
+        assert(path);
+
+        /* Either the file may be missing, or we return an fd to the final object, but both make no sense */
+        if (FLAGS_SET(flags, CHASE_NONEXISTENT | CHASE_OPEN))
+                return -EINVAL;
+
+        if (FLAGS_SET(flags, CHASE_STEP | CHASE_OPEN))
+                return -EINVAL;
+
+        if (isempty(path))
+                return -EINVAL;
+
+        /* This is a lot like canonicalize_file_name(), but takes an additional "root" parameter, that allows following
+         * symlinks relative to a root directory, instead of the root of the host.
+         *
+         * Note that "root" primarily matters if we encounter an absolute symlink. It is also used when following
+         * relative symlinks to ensure they cannot be used to "escape" the root directory. The path parameter passed is
+         * assumed to be already prefixed by it, except if the CHASE_PREFIX_ROOT flag is set, in which case it is first
+         * prefixed accordingly.
+         *
+         * Algorithmically this operates on two path buffers: "done" are the components of the path we already
+         * processed and resolved symlinks, "." and ".." of. "todo" are the components of the path we still need to
+         * process. On each iteration, we move one component from "todo" to "done", processing it's special meaning
+         * each time. The "todo" path always starts with at least one slash, the "done" path always ends in no
+         * slash. We always keep an O_PATH fd to the component we are currently processing, thus keeping lookup races
+         * at a minimum.
+         *
+         * Suggested usage: whenever you want to canonicalize a path, use this function. Pass the absolute path you got
+         * as-is: fully qualified and relative to your host's root. Optionally, specify the root parameter to tell this
+         * function what to do when encountering a symlink with an absolute path as directory: prefix it by the
+         * specified path.
+         *
+         * There are three ways to invoke this function:
+         *
+         * 1. Without CHASE_STEP or CHASE_OPEN: in this case the path is resolved and the normalized path is returned
+         *    in `ret`. The return value is < 0 on error. If CHASE_NONEXISTENT is also set 0 is returned if the file
+         *    doesn't exist, > 0 otherwise. If CHASE_NONEXISTENT is not set >= 0 is returned if the destination was
+         *    found, -ENOENT if it doesn't.
+         *
+         * 2. With CHASE_OPEN: in this case the destination is opened after chasing it as O_PATH and this file
+         *    descriptor is returned as return value. This is useful to open files relative to some root
+         *    directory. Note that the returned O_PATH file descriptors must be converted into a regular one (using
+         *    fd_reopen() or such) before it can be used for reading/writing. CHASE_OPEN may not be combined with
+         *    CHASE_NONEXISTENT.
+         *
+         * 3. With CHASE_STEP: in this case only a single step of the normalization is executed, i.e. only the first
+         *    symlink or ".." component of the path is resolved, and the resulting path is returned. This is useful if
+         *    a caller wants to trace the a path through the file system verbosely. Returns < 0 on error, > 0 if the
+         *    path is fully normalized, and == 0 for each normalization step. This may be combined with
+         *    CHASE_NONEXISTENT, in which case 1 is returned when a component is not found.
+         *
+         * 4. With CHASE_SAFE: in this case the path must not contain unsafe transitions, i.e. transitions from
+         *    unprivileged to privileged files or directories. In such cases the return value is -ENOLINK. If
+         *    CHASE_WARN is also set a warning describing the unsafe transition is emitted.
+         *
+         * 5. With CHASE_NO_AUTOFS: in this case if an autofs mount point is encountered, the path normalization is
+         *    aborted and -EREMOTE is returned. If CHASE_WARN is also set a warning showing the path of the mount point
+         *    is emitted.
+         *
+         * */
+
+        /* A root directory of "/" or "" is identical to none */
+        if (empty_or_root(original_root))
+                original_root = NULL;
+
+        if (!original_root && !ret && (flags & (CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_OPEN|CHASE_STEP)) == CHASE_OPEN) {
+                /* Shortcut the CHASE_OPEN case if the caller isn't interested in the actual path and has no root set
+                 * and doesn't care about any of the other special features we provide either. */
+                r = open(path, O_PATH|O_CLOEXEC|((flags & CHASE_NOFOLLOW) ? O_NOFOLLOW : 0));
+                if (r < 0)
+                        return -errno;
+
+                return r;
+        }
+
+        if (original_root) {
+                r = path_make_absolute_cwd(original_root, &root);
+                if (r < 0)
+                        return r;
+
+                if (flags & CHASE_PREFIX_ROOT) {
+
+                        /* We don't support relative paths in combination with a root directory */
+                        if (!path_is_absolute(path))
+                                return -EINVAL;
+
+                        path = prefix_roota(root, path);
+                }
+        }
+
+        r = path_make_absolute_cwd(path, &buffer);
+        if (r < 0)
+                return r;
+
+        fd = open("/", O_CLOEXEC|O_NOFOLLOW|O_PATH);
+        if (fd < 0)
+                return -errno;
+
+        if (flags & CHASE_SAFE) {
+                if (fstat(fd, &previous_stat) < 0)
+                        return -errno;
+        }
+
+        todo = buffer;
+        for (;;) {
+                _cleanup_free_ char *first = NULL;
+                _cleanup_close_ int child = -1;
+                struct stat st;
+                size_t n, m;
+
+                /* Determine length of first component in the path */
+                n = strspn(todo, "/");                  /* The slashes */
+                m = n + strcspn(todo + n, "/");         /* The entire length of the component */
+
+                /* Extract the first component. */
+                first = strndup(todo, m);
+                if (!first)
+                        return -ENOMEM;
+
+                todo += m;
+
+                /* Empty? Then we reached the end. */
+                if (isempty(first))
+                        break;
+
+                /* Just a single slash? Then we reached the end. */
+                if (path_equal(first, "/")) {
+                        /* Preserve the trailing slash */
+
+                        if (flags & CHASE_TRAIL_SLASH)
+                                if (!strextend(&done, "/", NULL))
+                                        return -ENOMEM;
+
+                        break;
+                }
+
+                /* Just a dot? Then let's eat this up. */
+                if (path_equal(first, "/."))
+                        continue;
+
+                /* Two dots? Then chop off the last bit of what we already found out. */
+                if (path_equal(first, "/..")) {
+                        _cleanup_free_ char *parent = NULL;
+                        _cleanup_close_ int fd_parent = -1;
+
+                        /* If we already are at the top, then going up will not change anything. This is in-line with
+                         * how the kernel handles this. */
+                        if (empty_or_root(done))
+                                continue;
+
+                        parent = dirname_malloc(done);
+                        if (!parent)
+                                return -ENOMEM;
+
+                        /* Don't allow this to leave the root dir.  */
+                        if (root &&
+                            path_startswith(done, root) &&
+                            !path_startswith(parent, root))
+                                continue;
+
+                        free_and_replace(done, parent);
+
+                        if (flags & CHASE_STEP)
+                                goto chased_one;
+
+                        fd_parent = openat(fd, "..", O_CLOEXEC|O_NOFOLLOW|O_PATH);
+                        if (fd_parent < 0)
+                                return -errno;
+
+                        if (flags & CHASE_SAFE) {
+                                if (fstat(fd_parent, &st) < 0)
+                                        return -errno;
+
+                                if (unsafe_transition(&previous_stat, &st))
+                                        return log_unsafe_transition(fd, fd_parent, path, flags);
+
+                                previous_stat = st;
+                        }
+
+                        safe_close(fd);
+                        fd = TAKE_FD(fd_parent);
+
+                        continue;
+                }
+
+                /* Otherwise let's see what this is. */
+                child = openat(fd, first + n, O_CLOEXEC|O_NOFOLLOW|O_PATH);
+                if (child < 0) {
+
+                        if (errno == ENOENT &&
+                            (flags & CHASE_NONEXISTENT) &&
+                            (isempty(todo) || path_is_normalized(todo))) {
+
+                                /* If CHASE_NONEXISTENT is set, and the path does not exist, then that's OK, return
+                                 * what we got so far. But don't allow this if the remaining path contains "../ or "./"
+                                 * or something else weird. */
+
+                                /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
+                                if (streq_ptr(done, "/"))
+                                        *done = '\0';
+
+                                if (!strextend(&done, first, todo, NULL))
+                                        return -ENOMEM;
+
+                                exists = false;
+                                break;
+                        }
+
+                        return -errno;
+                }
+
+                if (fstat(child, &st) < 0)
+                        return -errno;
+                if ((flags & CHASE_SAFE) &&
+                    unsafe_transition(&previous_stat, &st))
+                        return log_unsafe_transition(fd, child, path, flags);
+
+                previous_stat = st;
+
+                if ((flags & CHASE_NO_AUTOFS) &&
+                    fd_is_fs_type(child, AUTOFS_SUPER_MAGIC) > 0)
+                        return log_autofs_mount_point(child, path, flags);
+
+                if (S_ISLNK(st.st_mode) && !((flags & CHASE_NOFOLLOW) && isempty(todo))) {
+                        char *joined;
+
+                        _cleanup_free_ char *destination = NULL;
+
+                        /* This is a symlink, in this case read the destination. But let's make sure we don't follow
+                         * symlinks without bounds. */
+                        if (--max_follow <= 0)
+                                return -ELOOP;
+
+                        r = readlinkat_malloc(fd, first + n, &destination);
+                        if (r < 0)
+                                return r;
+                        if (isempty(destination))
+                                return -EINVAL;
+
+                        if (path_is_absolute(destination)) {
+
+                                /* An absolute destination. Start the loop from the beginning, but use the root
+                                 * directory as base. */
+
+                                safe_close(fd);
+                                fd = open(root ?: "/", O_CLOEXEC|O_NOFOLLOW|O_PATH);
+                                if (fd < 0)
+                                        return -errno;
+
+                                if (flags & CHASE_SAFE) {
+                                        if (fstat(fd, &st) < 0)
+                                                return -errno;
+
+                                        if (unsafe_transition(&previous_stat, &st))
+                                                return log_unsafe_transition(child, fd, path, flags);
+
+                                        previous_stat = st;
+                                }
+
+                                free(done);
+
+                                /* Note that we do not revalidate the root, we take it as is. */
+                                if (isempty(root))
+                                        done = NULL;
+                                else {
+                                        done = strdup(root);
+                                        if (!done)
+                                                return -ENOMEM;
+                                }
+
+                                /* Prefix what's left to do with what we just read, and start the loop again, but
+                                 * remain in the current directory. */
+                                joined = strjoin(destination, todo);
+                        } else
+                                joined = strjoin("/", destination, todo);
+                        if (!joined)
+                                return -ENOMEM;
+
+                        free(buffer);
+                        todo = buffer = joined;
+
+                        if (flags & CHASE_STEP)
+                                goto chased_one;
+
+                        continue;
+                }
+
+                /* If this is not a symlink, then let's just add the name we read to what we already verified. */
+                if (!done)
+                        done = TAKE_PTR(first);
+                else {
+                        /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
+                        if (streq(done, "/"))
+                                *done = '\0';
+
+                        if (!strextend(&done, first, NULL))
+                                return -ENOMEM;
+                }
+
+                /* And iterate again, but go one directory further down. */
+                safe_close(fd);
+                fd = TAKE_FD(child);
+        }
+
+        if (!done) {
+                /* Special case, turn the empty string into "/", to indicate the root directory. */
+                done = strdup("/");
+                if (!done)
+                        return -ENOMEM;
+        }
+
+        if (ret)
+                *ret = TAKE_PTR(done);
+
+        if (flags & CHASE_OPEN) {
+                /* Return the O_PATH fd we currently are looking to the caller. It can translate it to a proper fd by
+                 * opening /proc/self/fd/xyz. */
+
+                assert(fd >= 0);
+                return TAKE_FD(fd);
+        }
+
+        if (flags & CHASE_STEP)
+                return 1;
+
+        return exists;
+
+chased_one:
+        if (ret) {
+                char *c;
+
+                c = strjoin(strempty(done), todo);
+                if (!c)
+                        return -ENOMEM;
+
+                *ret = c;
+        }
+
+        return 0;
+}
+
+int chase_symlinks_and_open(
+                const char *path,
+                const char *root,
+                unsigned chase_flags,
+                int open_flags,
+                char **ret_path) {
+
+        _cleanup_close_ int path_fd = -1;
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        if (chase_flags & CHASE_NONEXISTENT)
+                return -EINVAL;
+
+        if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
+                /* Shortcut this call if none of the special features of this call are requested */
+                r = open(path, open_flags);
+                if (r < 0)
+                        return -errno;
+
+                return r;
+        }
+
+        path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
+        if (path_fd < 0)
+                return path_fd;
+
+        r = fd_reopen(path_fd, open_flags);
+        if (r < 0)
+                return r;
+
+        if (ret_path)
+                *ret_path = TAKE_PTR(p);
+
+        return r;
+}
+
+int chase_symlinks_and_opendir(
+                const char *path,
+                const char *root,
+                unsigned chase_flags,
+                char **ret_path,
+                DIR **ret_dir) {
+
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        _cleanup_close_ int path_fd = -1;
+        _cleanup_free_ char *p = NULL;
+        DIR *d;
+
+        if (!ret_dir)
+                return -EINVAL;
+        if (chase_flags & CHASE_NONEXISTENT)
+                return -EINVAL;
+
+        if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
+                /* Shortcut this call if none of the special features of this call are requested */
+                d = opendir(path);
+                if (!d)
+                        return -errno;
+
+                *ret_dir = d;
+                return 0;
+        }
+
+        path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
+        if (path_fd < 0)
+                return path_fd;
+
+        xsprintf(procfs_path, "/proc/self/fd/%i", path_fd);
+        d = opendir(procfs_path);
+        if (!d)
+                return -errno;
+
+        if (ret_path)
+                *ret_path = TAKE_PTR(p);
+
+        *ret_dir = d;
+        return 0;
+}
+
+int chase_symlinks_and_stat(
+                const char *path,
+                const char *root,
+                unsigned chase_flags,
+                char **ret_path,
+                struct stat *ret_stat) {
+
+        _cleanup_close_ int path_fd = -1;
+        _cleanup_free_ char *p = NULL;
+
+        assert(path);
+        assert(ret_stat);
+
+        if (chase_flags & CHASE_NONEXISTENT)
+                return -EINVAL;
+
+        if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
+                /* Shortcut this call if none of the special features of this call are requested */
+                if (stat(path, ret_stat) < 0)
+                        return -errno;
+
+                return 1;
+        }
+
+        path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
+        if (path_fd < 0)
+                return path_fd;
+
+        if (fstat(path_fd, ret_stat) < 0)
+                return -errno;
+
+        if (ret_path)
+                *ret_path = TAKE_PTR(p);
+
+        if (chase_flags & CHASE_OPEN)
+                return TAKE_FD(path_fd);
+
+        return 1;
+}
+
+int access_fd(int fd, int mode) {
+        char p[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1];
+        int r;
+
+        /* Like access() but operates on an already open fd */
+
+        xsprintf(p, "/proc/self/fd/%i", fd);
+        r = access(p, mode);
+        if (r < 0)
+                return -errno;
+
+        return r;
+}
+
+void unlink_tempfilep(char (*p)[]) {
+        /* If the file is created with mkstemp(), it will (almost always)
+         * change the suffix. Treat this as a sign that the file was
+         * successfully created. We ignore both the rare case where the
+         * original suffix is used and unlink failures. */
+        if (!endswith(*p, ".XXXXXX"))
+                (void) unlink_noerrno(*p);
+}
+
+int unlinkat_deallocate(int fd, const char *name, int flags) {
+        _cleanup_close_ int truncate_fd = -1;
+        struct stat st;
+        off_t l, bs;
+
+        /* Operates like unlinkat() but also deallocates the file contents if it is a regular file and there's no other
+         * link to it. This is useful to ensure that other processes that might have the file open for reading won't be
+         * able to keep the data pinned on disk forever. This call is particular useful whenever we execute clean-up
+         * jobs ("vacuuming"), where we want to make sure the data is really gone and the disk space released and
+         * returned to the free pool.
+         *
+         * Deallocation is preferably done by FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE (👊) if supported, which means
+         * the file won't change size. That's a good thing since we shouldn't needlessly trigger SIGBUS in other
+         * programs that have mmap()ed the file. (The assumption here is that changing file contents to all zeroes
+         * underneath those programs is the better choice than simply triggering SIGBUS in them which truncation does.)
+         * However if hole punching is not implemented in the kernel or file system we'll fall back to normal file
+         * truncation (🔪), as our goal of deallocating the data space trumps our goal of being nice to readers (💐).
+         *
+         * Note that we attempt deallocation, but failure to succeed with that is not considered fatal, as long as the
+         * primary job – to delete the file – is accomplished. */
+
+        if ((flags & AT_REMOVEDIR) == 0) {
+                truncate_fd = openat(fd, name, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_NONBLOCK);
+                if (truncate_fd < 0) {
+
+                        /* If this failed because the file doesn't exist propagate the error right-away. Also,
+                         * AT_REMOVEDIR wasn't set, and we tried to open the file for writing, which means EISDIR is
+                         * returned when this is a directory but we are not supposed to delete those, hence propagate
+                         * the error right-away too. */
+                        if (IN_SET(errno, ENOENT, EISDIR))
+                                return -errno;
+
+                        if (errno != ELOOP) /* don't complain if this is a symlink */
+                                log_debug_errno(errno, "Failed to open file '%s' for deallocation, ignoring: %m", name);
+                }
+        }
+
+        if (unlinkat(fd, name, flags) < 0)
+                return -errno;
+
+        if (truncate_fd < 0) /* Don't have a file handle, can't do more ☹️ */
+                return 0;
+
+        if (fstat(truncate_fd, &st) < 0) {
+                log_debug_errno(errno, "Failed to stat file '%s' for deallocation, ignoring: %m", name);
+                return 0;
+        }
+
+        if (!S_ISREG(st.st_mode) || st.st_blocks == 0 || st.st_nlink > 0)
+                return 0;
+
+        /* If this is a regular file, it actually took up space on disk and there are no other links it's time to
+         * punch-hole/truncate this to release the disk space. */
+
+        bs = MAX(st.st_blksize, 512);
+        l = DIV_ROUND_UP(st.st_size, bs) * bs; /* Round up to next block size */
+
+        if (fallocate(truncate_fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, 0, l) >= 0)
+                return 0; /* Successfully punched a hole! 😊 */
+
+        /* Fall back to truncation */
+        if (ftruncate(truncate_fd, 0) < 0) {
+                log_debug_errno(errno, "Failed to truncate file to 0, ignoring: %m");
+                return 0;
+        }
+
+        return 0;
+}
+
+int fsync_directory_of_file(int fd) {
+        _cleanup_free_ char *path = NULL;
+        _cleanup_close_ int dfd = -1;
+        int r;
+
+        r = fd_verify_regular(fd);
+        if (r < 0)
+                return r;
+
+        r = fd_get_path(fd, &path);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to query /proc/self/fd/%d%s: %m",
+                                fd,
+                                r == -EOPNOTSUPP ? ", ignoring" : "");
+
+                if (r == -EOPNOTSUPP)
+                        /* If /proc is not available, we're most likely running in some
+                         * chroot environment, and syncing the directory is not very
+                         * important in that case. Let's just silently do nothing. */
+                        return 0;
+
+                return r;
+        }
+
+        if (!path_is_absolute(path))
+                return -EINVAL;
+
+        dfd = open_parent(path, O_CLOEXEC, 0);
+        if (dfd < 0)
+                return dfd;
+
+        if (fsync(dfd) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int fsync_path_at(int at_fd, const char *path) {
+        _cleanup_close_ int opened_fd = -1;
+        int fd;
+
+        if (isempty(path)) {
+                if (at_fd == AT_FDCWD) {
+                        opened_fd = open(".", O_RDONLY|O_DIRECTORY|O_CLOEXEC);
+                        if (opened_fd < 0)
+                                return -errno;
+
+                        fd = opened_fd;
+                } else
+                        fd = at_fd;
+        } else {
+
+                opened_fd = openat(at_fd, path, O_RDONLY|O_CLOEXEC);
+                if (opened_fd < 0)
+                        return -errno;
+
+                fd = opened_fd;
+        }
+
+        if (fsync(fd) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int open_parent(const char *path, int flags, mode_t mode) {
+        _cleanup_free_ char *parent = NULL;
+        int fd;
+
+        if (isempty(path))
+                return -EINVAL;
+        if (path_equal(path, "/")) /* requesting the parent of the root dir is fishy, let's prohibit that */
+                return -EINVAL;
+
+        parent = dirname_malloc(path);
+        if (!parent)
+                return -ENOMEM;
+
+        /* Let's insist on O_DIRECTORY since the parent of a file or directory is a directory. Except if we open an
+         * O_TMPFILE file, because in that case we are actually create a regular file below the parent directory. */
+
+        if ((flags & O_PATH) == O_PATH)
+                flags |= O_DIRECTORY;
+        else if ((flags & O_TMPFILE) != O_TMPFILE)
+                flags |= O_DIRECTORY|O_RDONLY;
+
+        fd = open(parent, flags, mode);
+        if (fd < 0)
+                return -errno;
+
+        return fd;
+}
diff --git a/src/basic/fs-util.h b/src/basic/fs-util.h
new file mode 100644
index 0000000..7ad030b
--- /dev/null
+++ b/src/basic/fs-util.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/inotify.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "time-util.h"
+#include "util.h"
+
+int unlink_noerrno(const char *path);
+
+int rmdir_parents(const char *path, const char *stop);
+
+int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
+
+int readlinkat_malloc(int fd, const char *p, char **ret);
+int readlink_malloc(const char *p, char **r);
+int readlink_value(const char *p, char **ret);
+int readlink_and_make_absolute(const char *p, char **r);
+
+int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid);
+int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid);
+
+int fchmod_umask(int fd, mode_t mode);
+int fchmod_opath(int fd, mode_t m);
+
+int fd_warn_permissions(const char *path, int fd);
+
+#define laccess(path, mode) faccessat(AT_FDCWD, (path), (mode), AT_SYMLINK_NOFOLLOW)
+
+int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode);
+int touch(const char *path);
+
+int symlink_idempotent(const char *from, const char *to, bool make_relative);
+
+int symlink_atomic(const char *from, const char *to);
+int mknod_atomic(const char *path, mode_t mode, dev_t dev);
+int mkfifo_atomic(const char *path, mode_t mode);
+int mkfifoat_atomic(int dir_fd, const char *path, mode_t mode);
+
+int get_files_in_directory(const char *path, char ***list);
+
+int tmp_dir(const char **ret);
+int var_tmp_dir(const char **ret);
+
+int unlink_or_warn(const char *filename);
+
+#define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
+
+#define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
+        for ((e) = &buffer.ev;                                \
+             (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
+             (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
+
+union inotify_event_buffer {
+        struct inotify_event ev;
+        uint8_t raw[INOTIFY_EVENT_MAX];
+};
+
+int inotify_add_watch_fd(int fd, int what, uint32_t mask);
+
+enum {
+        CHASE_PREFIX_ROOT = 1 << 0, /* If set, the specified path will be prefixed by the specified root before beginning the iteration */
+        CHASE_NONEXISTENT = 1 << 1, /* If set, it's OK if the path doesn't actually exist. */
+        CHASE_NO_AUTOFS   = 1 << 2, /* If set, return -EREMOTE if autofs mount point found */
+        CHASE_SAFE        = 1 << 3, /* If set, return EPERM if we ever traverse from unprivileged to privileged files or directories */
+        CHASE_OPEN        = 1 << 4, /* If set, return an O_PATH object to the final component */
+        CHASE_TRAIL_SLASH = 1 << 5, /* If set, any trailing slash will be preserved */
+        CHASE_STEP        = 1 << 6, /* If set, just execute a single step of the normalization */
+        CHASE_NOFOLLOW    = 1 << 7, /* Only valid with CHASE_OPEN: when the path's right-most component refers to symlink return O_PATH fd of the symlink, rather than following it. */
+        CHASE_WARN        = 1 << 8, /* Emit an appropriate warning when an error is encountered */
+};
+
+/* How many iterations to execute before returning -ELOOP */
+#define CHASE_SYMLINKS_MAX 32
+
+int chase_symlinks(const char *path_with_prefix, const char *root, unsigned flags, char **ret);
+
+int chase_symlinks_and_open(const char *path, const char *root, unsigned chase_flags, int open_flags, char **ret_path);
+int chase_symlinks_and_opendir(const char *path, const char *root, unsigned chase_flags, char **ret_path, DIR **ret_dir);
+int chase_symlinks_and_stat(const char *path, const char *root, unsigned chase_flags, char **ret_path, struct stat *ret_stat);
+
+/* Useful for usage with _cleanup_(), removes a directory and frees the pointer */
+static inline void rmdir_and_free(char *p) {
+        PROTECT_ERRNO;
+        (void) rmdir(p);
+        free(p);
+}
+DEFINE_TRIVIAL_CLEANUP_FUNC(char*, rmdir_and_free);
+
+static inline void unlink_and_free(char *p) {
+        (void) unlink_noerrno(p);
+        free(p);
+}
+DEFINE_TRIVIAL_CLEANUP_FUNC(char*, unlink_and_free);
+
+int access_fd(int fd, int mode);
+
+void unlink_tempfilep(char (*p)[]);
+int unlinkat_deallocate(int fd, const char *name, int flags);
+
+int fsync_directory_of_file(int fd);
+int fsync_path_at(int at_fd, const char *path);
+
+int open_parent(const char *path, int flags, mode_t mode);
diff --git a/src/basic/gcrypt-util.c b/src/basic/gcrypt-util.c
new file mode 100644
index 0000000..f304a2b
--- /dev/null
+++ b/src/basic/gcrypt-util.c
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#if HAVE_GCRYPT
+#include <gcrypt.h>
+
+#include "gcrypt-util.h"
+#include "hexdecoct.h"
+
+void initialize_libgcrypt(bool secmem) {
+        const char *p;
+        if (gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P))
+                return;
+
+        p = gcry_check_version("1.4.5");
+        assert(p);
+
+        /* Turn off "secmem". Clients which wish to make use of this
+         * feature should initialize the library manually */
+        if (!secmem)
+                gcry_control(GCRYCTL_DISABLE_SECMEM);
+        gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
+}
+
+int string_hashsum(const char *s, size_t len, int md_algorithm, char **out) {
+        _cleanup_(gcry_md_closep) gcry_md_hd_t md = NULL;
+        size_t hash_size;
+        void *hash;
+        char *enc;
+
+        initialize_libgcrypt(false);
+
+        hash_size = gcry_md_get_algo_dlen(md_algorithm);
+        assert(hash_size > 0);
+
+        gcry_md_open(&md, md_algorithm, 0);
+        if (!md)
+                return -EIO;
+
+        gcry_md_write(md, s, len);
+
+        hash = gcry_md_read(md, 0);
+        if (!hash)
+                return -EIO;
+
+        enc = hexmem(hash, hash_size);
+        if (!enc)
+                return -ENOMEM;
+
+        *out = enc;
+        return 0;
+}
+#endif
diff --git a/src/basic/gcrypt-util.h b/src/basic/gcrypt-util.h
new file mode 100644
index 0000000..87eb606
--- /dev/null
+++ b/src/basic/gcrypt-util.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#pragma once
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+#if HAVE_GCRYPT
+#include <gcrypt.h>
+
+#include "macro.h"
+
+void initialize_libgcrypt(bool secmem);
+int string_hashsum(const char *s, size_t len, int md_algorithm, char **out);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(gcry_md_hd_t, gcry_md_close);
+#endif
+
+static inline int string_hashsum_sha224(const char *s, size_t len, char **out) {
+#if HAVE_GCRYPT
+        return string_hashsum(s, len, GCRY_MD_SHA224, out);
+#else
+        return -EOPNOTSUPP;
+#endif
+}
+
+static inline int string_hashsum_sha256(const char *s, size_t len, char **out) {
+#if HAVE_GCRYPT
+        return string_hashsum(s, len, GCRY_MD_SHA256, out);
+#else
+        return -EOPNOTSUPP;
+#endif
+}
diff --git a/src/basic/generate-af-list.sh b/src/basic/generate-af-list.sh
new file mode 100755
index 0000000..5bf244c
--- /dev/null
+++ b/src/basic/generate-af-list.sh
@@ -0,0 +1,6 @@
+#!/bin/sh
+set -eu
+
+$1 -E -dM -include sys/socket.h -include "$2" -include "$3" - </dev/null | \
+        grep -Ev 'AF_UNSPEC|AF_MAX' | \
+        awk '/^#define[ \t]+AF_[^ \t]+[ \t]+[AP]F_[^ \t]/ { print $2; }'
diff --git a/src/basic/generate-arphrd-list.sh b/src/basic/generate-arphrd-list.sh
new file mode 100755
index 0000000..e6e874a
--- /dev/null
+++ b/src/basic/generate-arphrd-list.sh
@@ -0,0 +1,6 @@
+#!/bin/sh
+set -eu
+
+$1 -dM -include net/if_arp.h -include "$2" -include "$3" - </dev/null | \
+        awk '/^#define[ \t]+ARPHRD_[^ \t]+[ \t]+[^ \t]/ { print $2; }' | \
+        sed -e 's/ARPHRD_//'
diff --git a/src/basic/generate-cap-list.sh b/src/basic/generate-cap-list.sh
new file mode 100755
index 0000000..0628d24
--- /dev/null
+++ b/src/basic/generate-cap-list.sh
@@ -0,0 +1,6 @@
+#!/bin/sh
+set -eu
+
+$1 -dM -include linux/capability.h -include "$2" -include "$3" - </dev/null | \
+        awk '/^#define[ \t]+CAP_[A-Z_]+[ \t]+/ { print $2; }' | \
+        grep -v CAP_LAST_CAP
diff --git a/src/basic/generate-errno-list.sh b/src/basic/generate-errno-list.sh
new file mode 100755
index 0000000..953d5e3
--- /dev/null
+++ b/src/basic/generate-errno-list.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+set -eu
+
+$1 -dM -include errno.h - </dev/null | \
+        awk '/^#define[ \t]+E[^ _]+[ \t]+/ { print $2; }'
diff --git a/src/basic/glob-util.c b/src/basic/glob-util.c
new file mode 100644
index 0000000..9fac676
--- /dev/null
+++ b/src/basic/glob-util.c
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <glob.h>
+#include <sys/types.h>
+
+#include "dirent-util.h"
+#include "glob-util.h"
+#include "macro.h"
+#include "path-util.h"
+#include "strv.h"
+
+static void closedir_wrapper(void* v) {
+        (void) closedir(v);
+}
+
+int safe_glob(const char *path, int flags, glob_t *pglob) {
+        int k;
+
+        /* We want to set GLOB_ALTDIRFUNC ourselves, don't allow it to be set. */
+        assert(!(flags & GLOB_ALTDIRFUNC));
+
+        if (!pglob->gl_closedir)
+                pglob->gl_closedir = closedir_wrapper;
+        if (!pglob->gl_readdir)
+                pglob->gl_readdir = (struct dirent *(*)(void *)) readdir_no_dot;
+        if (!pglob->gl_opendir)
+                pglob->gl_opendir = (void *(*)(const char *)) opendir;
+        if (!pglob->gl_lstat)
+                pglob->gl_lstat = lstat;
+        if (!pglob->gl_stat)
+                pglob->gl_stat = stat;
+
+        errno = 0;
+        k = glob(path, flags | GLOB_ALTDIRFUNC, NULL, pglob);
+
+        if (k == GLOB_NOMATCH)
+                return -ENOENT;
+        if (k == GLOB_NOSPACE)
+                return -ENOMEM;
+        if (k != 0)
+                return errno > 0 ? -errno : -EIO;
+        if (strv_isempty(pglob->gl_pathv))
+                return -ENOENT;
+
+        return 0;
+}
+
+int glob_exists(const char *path) {
+        _cleanup_globfree_ glob_t g = {};
+        int k;
+
+        assert(path);
+
+        k = safe_glob(path, GLOB_NOSORT|GLOB_BRACE, &g);
+        if (k == -ENOENT)
+                return false;
+        if (k < 0)
+                return k;
+        return true;
+}
+
+int glob_extend(char ***strv, const char *path) {
+        _cleanup_globfree_ glob_t g = {};
+        int k;
+
+        k = safe_glob(path, GLOB_NOSORT|GLOB_BRACE, &g);
+        if (k < 0)
+                return k;
+
+        return strv_extend_strv(strv, g.gl_pathv, false);
+}
diff --git a/src/basic/glob-util.h b/src/basic/glob-util.h
new file mode 100644
index 0000000..8e226c1
--- /dev/null
+++ b/src/basic/glob-util.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <glob.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include "macro.h"
+#include "string-util.h"
+
+/* Note: this function modifies pglob to set various functions. */
+int safe_glob(const char *path, int flags, glob_t *pglob);
+
+int glob_exists(const char *path);
+int glob_extend(char ***strv, const char *path);
+
+#define _cleanup_globfree_ _cleanup_(globfree)
+
+_pure_ static inline bool string_is_glob(const char *p) {
+        /* Check if a string contains any glob patterns. */
+        return !!strpbrk(p, GLOB_CHARS);
+}
diff --git a/src/basic/gunicode.c b/src/basic/gunicode.c
new file mode 100644
index 0000000..c51b1a7
--- /dev/null
+++ b/src/basic/gunicode.c
@@ -0,0 +1,110 @@
+/* gunicode.c - Unicode manipulation functions
+ *
+ *  Copyright (C) 1999, 2000 Tom Tromey
+ *  Copyright © 2000, 2005 Red Hat, Inc.
+ */
+
+#include "gunicode.h"
+
+#define unichar uint32_t
+
+/**
+ * g_utf8_prev_char:
+ * @p: a pointer to a position within a UTF-8 encoded string
+ *
+ * Finds the previous UTF-8 character in the string before @p.
+ *
+ * @p does not have to be at the beginning of a UTF-8 character. No check
+ * is made to see if the character found is actually valid other than
+ * it starts with an appropriate byte. If @p might be the first
+ * character of the string, you must use g_utf8_find_prev_char() instead.
+ *
+ * Return value: a pointer to the found character.
+ **/
+char *
+utf8_prev_char (const char *p)
+{
+  for (;;)
+    {
+      p--;
+      if ((*p & 0xc0) != 0x80)
+        return (char *)p;
+    }
+}
+
+struct Interval
+{
+  unichar start, end;
+};
+
+static int
+interval_compare (const void *key, const void *elt)
+{
+  unichar c = (unichar) (long) (key);
+  struct Interval *interval = (struct Interval *)elt;
+
+  if (c < interval->start)
+    return -1;
+  if (c > interval->end)
+    return +1;
+
+  return 0;
+}
+
+/*
+ * NOTE:
+ *
+ * The tables for g_unichar_iswide() and g_unichar_iswide_cjk() are
+ * generated from the Unicode Character Database's file
+ * extracted/DerivedEastAsianWidth.txt using the gen-iswide-table.py
+ * in this way:
+ *
+ *   ./gen-iswide-table.py < path/to/ucd/extracted/DerivedEastAsianWidth.txt | fmt
+ *
+ * Last update for Unicode 6.0.
+ */
+
+/**
+ * g_unichar_iswide:
+ * @c: a Unicode character
+ *
+ * Determines if a character is typically rendered in a double-width
+ * cell.
+ *
+ * Return value: %TRUE if the character is wide
+ **/
+bool
+unichar_iswide (unichar c)
+{
+  /* See NOTE earlier for how to update this table. */
+  static const struct Interval wide[] = {
+    {0x1100, 0x115F}, {0x2329, 0x232A}, {0x2E80, 0x2E99}, {0x2E9B, 0x2EF3},
+    {0x2F00, 0x2FD5}, {0x2FF0, 0x2FFB}, {0x3000, 0x303E}, {0x3041, 0x3096},
+    {0x3099, 0x30FF}, {0x3105, 0x312D}, {0x3131, 0x318E}, {0x3190, 0x31BA},
+    {0x31C0, 0x31E3}, {0x31F0, 0x321E}, {0x3220, 0x3247}, {0x3250, 0x32FE},
+    {0x3300, 0x4DBF}, {0x4E00, 0xA48C}, {0xA490, 0xA4C6}, {0xA960, 0xA97C},
+    {0xAC00, 0xD7A3}, {0xF900, 0xFAFF}, {0xFE10, 0xFE19}, {0xFE30, 0xFE52},
+    {0xFE54, 0xFE66}, {0xFE68, 0xFE6B}, {0xFF01, 0xFF60}, {0xFFE0, 0xFFE6},
+    {0x1B000, 0x1B001}, {0x1F200, 0x1F202}, {0x1F210, 0x1F23A},
+    {0x1F240, 0x1F248}, {0x1F250, 0x1F251},
+    {0x1F300, 0x1F567}, /* Miscellaneous Symbols and Pictographs */
+    {0x20000, 0x2FFFD}, {0x30000, 0x3FFFD},
+  };
+
+  if (bsearch ((void *)(uintptr_t)c, wide, (sizeof (wide) / sizeof ((wide)[0])), sizeof wide[0],
+               interval_compare))
+    return true;
+
+  return false;
+}
+
+const char utf8_skip_data[256] = {
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,1,1
+};
diff --git a/src/basic/gunicode.h b/src/basic/gunicode.h
new file mode 100644
index 0000000..a16b7b6
--- /dev/null
+++ b/src/basic/gunicode.h
@@ -0,0 +1,30 @@
+#pragma once
+
+/* gunicode.h - Unicode manipulation functions
+ *
+ *  Copyright (C) 1999, 2000 Tom Tromey
+ *  Copyright © 2000, 2005 Red Hat, Inc.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+char *utf8_prev_char (const char *p);
+
+extern const char utf8_skip_data[256];
+
+/**
+ * g_utf8_next_char:
+ * @p: Pointer to the start of a valid UTF-8 character
+ *
+ * Skips to the next character in a UTF-8 string. The string must be
+ * valid; this macro is as fast as possible, and has no error-checking.
+ * You would use this macro to iterate over a string character by
+ * character. The macro returns the start of the next UTF-8 character.
+ * Before using this macro, use g_utf8_validate() to validate strings
+ * that may contain invalid UTF-8.
+ */
+#define utf8_next_char(p) (char *)((p) + utf8_skip_data[*(const unsigned char *)(p)])
+
+bool unichar_iswide (uint32_t c);
diff --git a/src/basic/hash-funcs.c b/src/basic/hash-funcs.c
new file mode 100644
index 0000000..1be43d4
--- /dev/null
+++ b/src/basic/hash-funcs.c
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <string.h>
+
+#include "hash-funcs.h"
+#include "path-util.h"
+
+void string_hash_func(const char *p, struct siphash *state) {
+        siphash24_compress(p, strlen(p) + 1, state);
+}
+
+DEFINE_HASH_OPS(string_hash_ops, char, string_hash_func, string_compare_func);
+
+void path_hash_func(const char *q, struct siphash *state) {
+        size_t n;
+
+        assert(q);
+        assert(state);
+
+        /* Calculates a hash for a path in a way this duplicate inner slashes don't make a differences, and also
+         * whether there's a trailing slash or not. This fits well with the semantics of path_compare(), which does
+         * similar checks and also doesn't care for trailing slashes. Note that relative and absolute paths (i.e. those
+         * which begin in a slash or not) will hash differently though. */
+
+        n = strspn(q, "/");
+        if (n > 0) { /* Eat up initial slashes, and add one "/" to the hash for all of them */
+                siphash24_compress(q, 1, state);
+                q += n;
+        }
+
+        for (;;) {
+                /* Determine length of next component */
+                n = strcspn(q, "/");
+                if (n == 0) /* Reached the end? */
+                        break;
+
+                /* Add this component to the hash and skip over it */
+                siphash24_compress(q, n, state);
+                q += n;
+
+                /* How many slashes follow this component? */
+                n = strspn(q, "/");
+                if (q[n] == 0) /* Is this a trailing slash? If so, we are at the end, and don't care about the slashes anymore */
+                        break;
+
+                /* We are not add the end yet. Hash exactly one slash for all of the ones we just encountered. */
+                siphash24_compress(q, 1, state);
+                q += n;
+        }
+}
+
+int path_compare_func(const char *a, const char *b) {
+        return path_compare(a, b);
+}
+
+DEFINE_HASH_OPS(path_hash_ops, char, path_hash_func, path_compare_func);
+
+void trivial_hash_func(const void *p, struct siphash *state) {
+        siphash24_compress(&p, sizeof(p), state);
+}
+
+int trivial_compare_func(const void *a, const void *b) {
+        return CMP(a, b);
+}
+
+const struct hash_ops trivial_hash_ops = {
+        .hash = trivial_hash_func,
+        .compare = trivial_compare_func,
+};
+
+void uint64_hash_func(const uint64_t *p, struct siphash *state) {
+        siphash24_compress(p, sizeof(uint64_t), state);
+}
+
+int uint64_compare_func(const uint64_t *a, const uint64_t *b) {
+        return CMP(*a, *b);
+}
+
+DEFINE_HASH_OPS(uint64_hash_ops, uint64_t, uint64_hash_func, uint64_compare_func);
+
+#if SIZEOF_DEV_T != 8
+void devt_hash_func(const dev_t *p, struct siphash *state) {
+        siphash24_compress(p, sizeof(dev_t), state);
+}
+
+int devt_compare_func(const dev_t *a, const dev_t *b) {
+        return CMP(*a, *b);
+}
+
+DEFINE_HASH_OPS(devt_hash_ops, dev_t, devt_hash_func, devt_compare_func);
+#endif
diff --git a/src/basic/hash-funcs.h b/src/basic/hash-funcs.h
new file mode 100644
index 0000000..3d2ae4b
--- /dev/null
+++ b/src/basic/hash-funcs.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "alloc-util.h"
+#include "macro.h"
+#include "siphash24.h"
+
+typedef void (*hash_func_t)(const void *p, struct siphash *state);
+typedef int (*compare_func_t)(const void *a, const void *b);
+
+struct hash_ops {
+        hash_func_t hash;
+        compare_func_t compare;
+        free_func_t free_key;
+        free_func_t free_value;
+};
+
+#define _DEFINE_HASH_OPS(uq, name, type, hash_func, compare_func, free_key_func, free_value_func, scope) \
+        _unused_ static void (* UNIQ_T(static_hash_wrapper, uq))(const type *, struct siphash *) = hash_func; \
+        _unused_ static int (* UNIQ_T(static_compare_wrapper, uq))(const type *, const type *) = compare_func; \
+        scope const struct hash_ops name = {                            \
+                .hash = (hash_func_t) hash_func,                        \
+                .compare = (compare_func_t) compare_func,               \
+                .free_key = free_key_func,                              \
+                .free_value = free_value_func,                          \
+        }
+
+#define _DEFINE_FREE_FUNC(uq, type, wrapper_name, func)                 \
+        /* Type-safe free function */                                   \
+        static void UNIQ_T(wrapper_name, uq)(void *a) {                 \
+                type *_a = a;                                           \
+                func(_a);                                               \
+        }
+
+#define _DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(uq, name, type, hash_func, compare_func, free_func, scope) \
+        _DEFINE_FREE_FUNC(uq, type, static_free_wrapper, free_func);    \
+        _DEFINE_HASH_OPS(uq, name, type, hash_func, compare_func,       \
+                         UNIQ_T(static_free_wrapper, uq), NULL, scope)
+
+#define _DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(uq, name, type, hash_func, compare_func, type_value, free_func, scope) \
+        _DEFINE_FREE_FUNC(uq, type_value, static_free_wrapper, free_func); \
+        _DEFINE_HASH_OPS(uq, name, type, hash_func, compare_func,       \
+                         NULL, UNIQ_T(static_free_wrapper, uq), scope)
+
+#define _DEFINE_HASH_OPS_FULL(uq, name, type, hash_func, compare_func, free_key_func, type_value, free_value_func, scope) \
+        _DEFINE_FREE_FUNC(uq, type, static_free_key_wrapper, free_key_func); \
+        _DEFINE_FREE_FUNC(uq, type_value, static_free_value_wrapper, free_value_func); \
+        _DEFINE_HASH_OPS(uq, name, type, hash_func, compare_func,       \
+                         UNIQ_T(static_free_key_wrapper, uq),           \
+                         UNIQ_T(static_free_value_wrapper, uq), scope)
+
+#define DEFINE_HASH_OPS(name, type, hash_func, compare_func)            \
+        _DEFINE_HASH_OPS(UNIQ, name, type, hash_func, compare_func, NULL, NULL,)
+
+#define DEFINE_PRIVATE_HASH_OPS(name, type, hash_func, compare_func)    \
+        _DEFINE_HASH_OPS(UNIQ, name, type, hash_func, compare_func, NULL, NULL, static)
+
+#define DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(name, type, hash_func, compare_func, free_func) \
+        _DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(UNIQ, name, type, hash_func, compare_func, free_func,)
+
+#define DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(name, type, hash_func, compare_func, free_func) \
+        _DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(UNIQ, name, type, hash_func, compare_func, free_func, static)
+
+#define DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(name, type, hash_func, compare_func, value_type, free_func) \
+        _DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(UNIQ, name, type, hash_func, compare_func, value_type, free_func,)
+
+#define DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(name, type, hash_func, compare_func, value_type, free_func) \
+        _DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(UNIQ, name, type, hash_func, compare_func, value_type, free_func, static)
+
+#define DEFINE_HASH_OPS_FULL(name, type, hash_func, compare_func, free_key_func, value_type, free_value_func) \
+        _DEFINE_HASH_OPS_FULL(UNIQ, name, type, hash_func, compare_func, free_key_func, value_type, free_value_func,)
+
+#define DEFINE_PRIVATE_HASH_OPS_FULL(name, type, hash_func, compare_func, free_key_func, value_type, free_value_func) \
+        _DEFINE_HASH_OPS_FULL(UNIQ, name, type, hash_func, compare_func, free_key_func, value_type, free_value_func, static)
+
+void string_hash_func(const char *p, struct siphash *state);
+#define string_compare_func strcmp
+extern const struct hash_ops string_hash_ops;
+
+void path_hash_func(const char *p, struct siphash *state);
+int path_compare_func(const char *a, const char *b) _pure_;
+extern const struct hash_ops path_hash_ops;
+
+/* This will compare the passed pointers directly, and will not dereference them. This is hence not useful for strings
+ * or suchlike. */
+void trivial_hash_func(const void *p, struct siphash *state);
+int trivial_compare_func(const void *a, const void *b) _const_;
+extern const struct hash_ops trivial_hash_ops;
+
+/* 32bit values we can always just embed in the pointer itself, but in order to support 32bit archs we need store 64bit
+ * values indirectly, since they don't fit in a pointer. */
+void uint64_hash_func(const uint64_t *p, struct siphash *state);
+int uint64_compare_func(const uint64_t *a, const uint64_t *b) _pure_;
+extern const struct hash_ops uint64_hash_ops;
+
+/* On some archs dev_t is 32bit, and on others 64bit. And sometimes it's 64bit on 32bit archs, and sometimes 32bit on
+ * 64bit archs. Yuck! */
+#if SIZEOF_DEV_T != 8
+void devt_hash_func(const dev_t *p, struct siphash *state) _pure_;
+int devt_compare_func(const dev_t *a, const dev_t *b) _pure_;
+extern const struct hash_ops devt_hash_ops;
+#else
+#define devt_hash_func uint64_hash_func
+#define devt_compare_func uint64_compare_func
+#define devt_hash_ops uint64_hash_ops
+#endif
diff --git a/src/basic/hashmap.c b/src/basic/hashmap.c
new file mode 100644
index 0000000..66e9e00
--- /dev/null
+++ b/src/basic/hashmap.c
@@ -0,0 +1,1911 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "fileio.h"
+#include "hashmap.h"
+#include "macro.h"
+#include "mempool.h"
+#include "process-util.h"
+#include "random-util.h"
+#include "set.h"
+#include "siphash24.h"
+#include "string-util.h"
+#include "strv.h"
+#include "util.h"
+
+#if ENABLE_DEBUG_HASHMAP
+#include <pthread.h>
+#include "list.h"
+#endif
+
+/*
+ * Implementation of hashmaps.
+ * Addressing: open
+ *   - uses less RAM compared to closed addressing (chaining), because
+ *     our entries are small (especially in Sets, which tend to contain
+ *     the majority of entries in systemd).
+ * Collision resolution: Robin Hood
+ *   - tends to equalize displacement of entries from their optimal buckets.
+ * Probe sequence: linear
+ *   - though theoretically worse than random probing/uniform hashing/double
+ *     hashing, it is good for cache locality.
+ *
+ * References:
+ * Celis, P. 1986. Robin Hood Hashing.
+ * Ph.D. Dissertation. University of Waterloo, Waterloo, Ont., Canada, Canada.
+ * https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf
+ * - The results are derived for random probing. Suggests deletion with
+ *   tombstones and two mean-centered search methods. None of that works
+ *   well for linear probing.
+ *
+ * Janson, S. 2005. Individual displacements for linear probing hashing with different insertion policies.
+ * ACM Trans. Algorithms 1, 2 (October 2005), 177-213.
+ * DOI=10.1145/1103963.1103964 http://doi.acm.org/10.1145/1103963.1103964
+ * http://www.math.uu.se/~svante/papers/sj157.pdf
+ * - Applies to Robin Hood with linear probing. Contains remarks on
+ *   the unsuitability of mean-centered search with linear probing.
+ *
+ * Viola, A. 2005. Exact distribution of individual displacements in linear probing hashing.
+ * ACM Trans. Algorithms 1, 2 (October 2005), 214-242.
+ * DOI=10.1145/1103963.1103965 http://doi.acm.org/10.1145/1103963.1103965
+ * - Similar to Janson. Note that Viola writes about C_{m,n} (number of probes
+ *   in a successful search), and Janson writes about displacement. C = d + 1.
+ *
+ * Goossaert, E. 2013. Robin Hood hashing: backward shift deletion.
+ * http://codecapsule.com/2013/11/17/robin-hood-hashing-backward-shift-deletion/
+ * - Explanation of backward shift deletion with pictures.
+ *
+ * Khuong, P. 2013. The Other Robin Hood Hashing.
+ * http://www.pvk.ca/Blog/2013/11/26/the-other-robin-hood-hashing/
+ * - Short summary of random vs. linear probing, and tombstones vs. backward shift.
+ */
+
+/*
+ * XXX Ideas for improvement:
+ * For unordered hashmaps, randomize iteration order, similarly to Perl:
+ * http://blog.booking.com/hardening-perls-hash-function.html
+ */
+
+/* INV_KEEP_FREE = 1 / (1 - max_load_factor)
+ * e.g. 1 / (1 - 0.8) = 5 ... keep one fifth of the buckets free. */
+#define INV_KEEP_FREE            5U
+
+/* Fields common to entries of all hashmap/set types */
+struct hashmap_base_entry {
+        const void *key;
+};
+
+/* Entry types for specific hashmap/set types
+ * hashmap_base_entry must be at the beginning of each entry struct. */
+
+struct plain_hashmap_entry {
+        struct hashmap_base_entry b;
+        void *value;
+};
+
+struct ordered_hashmap_entry {
+        struct plain_hashmap_entry p;
+        unsigned iterate_next, iterate_previous;
+};
+
+struct set_entry {
+        struct hashmap_base_entry b;
+};
+
+/* In several functions it is advantageous to have the hash table extended
+ * virtually by a couple of additional buckets. We reserve special index values
+ * for these "swap" buckets. */
+#define _IDX_SWAP_BEGIN     (UINT_MAX - 3)
+#define IDX_PUT             (_IDX_SWAP_BEGIN + 0)
+#define IDX_TMP             (_IDX_SWAP_BEGIN + 1)
+#define _IDX_SWAP_END       (_IDX_SWAP_BEGIN + 2)
+
+#define IDX_FIRST           (UINT_MAX - 1) /* special index for freshly initialized iterators */
+#define IDX_NIL             UINT_MAX       /* special index value meaning "none" or "end" */
+
+assert_cc(IDX_FIRST == _IDX_SWAP_END);
+assert_cc(IDX_FIRST == _IDX_ITERATOR_FIRST);
+
+/* Storage space for the "swap" buckets.
+ * All entry types can fit into a ordered_hashmap_entry. */
+struct swap_entries {
+        struct ordered_hashmap_entry e[_IDX_SWAP_END - _IDX_SWAP_BEGIN];
+};
+
+/* Distance from Initial Bucket */
+typedef uint8_t dib_raw_t;
+#define DIB_RAW_OVERFLOW ((dib_raw_t)0xfdU)   /* indicates DIB value is greater than representable */
+#define DIB_RAW_REHASH   ((dib_raw_t)0xfeU)   /* entry yet to be rehashed during in-place resize */
+#define DIB_RAW_FREE     ((dib_raw_t)0xffU)   /* a free bucket */
+#define DIB_RAW_INIT     ((char)DIB_RAW_FREE) /* a byte to memset a DIB store with when initializing */
+
+#define DIB_FREE UINT_MAX
+
+#if ENABLE_DEBUG_HASHMAP
+struct hashmap_debug_info {
+        LIST_FIELDS(struct hashmap_debug_info, debug_list);
+        unsigned max_entries;  /* high watermark of n_entries */
+
+        /* who allocated this hashmap */
+        int line;
+        const char *file;
+        const char *func;
+
+        /* fields to detect modification while iterating */
+        unsigned put_count;    /* counts puts into the hashmap */
+        unsigned rem_count;    /* counts removals from hashmap */
+        unsigned last_rem_idx; /* remembers last removal index */
+};
+
+/* Tracks all existing hashmaps. Get at it from gdb. See sd_dump_hashmaps.py */
+static LIST_HEAD(struct hashmap_debug_info, hashmap_debug_list);
+static pthread_mutex_t hashmap_debug_list_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+#define HASHMAP_DEBUG_FIELDS struct hashmap_debug_info debug;
+
+#else /* !ENABLE_DEBUG_HASHMAP */
+#define HASHMAP_DEBUG_FIELDS
+#endif /* ENABLE_DEBUG_HASHMAP */
+
+enum HashmapType {
+        HASHMAP_TYPE_PLAIN,
+        HASHMAP_TYPE_ORDERED,
+        HASHMAP_TYPE_SET,
+        _HASHMAP_TYPE_MAX
+};
+
+struct _packed_ indirect_storage {
+        void *storage;                     /* where buckets and DIBs are stored */
+        uint8_t  hash_key[HASH_KEY_SIZE];  /* hash key; changes during resize */
+
+        unsigned n_entries;                /* number of stored entries */
+        unsigned n_buckets;                /* number of buckets */
+
+        unsigned idx_lowest_entry;         /* Index below which all buckets are free.
+                                              Makes "while(hashmap_steal_first())" loops
+                                              O(n) instead of O(n^2) for unordered hashmaps. */
+        uint8_t  _pad[3];                  /* padding for the whole HashmapBase */
+        /* The bitfields in HashmapBase complete the alignment of the whole thing. */
+};
+
+struct direct_storage {
+        /* This gives us 39 bytes on 64bit, or 35 bytes on 32bit.
+         * That's room for 4 set_entries + 4 DIB bytes + 3 unused bytes on 64bit,
+         *              or 7 set_entries + 7 DIB bytes + 0 unused bytes on 32bit. */
+        uint8_t storage[sizeof(struct indirect_storage)];
+};
+
+#define DIRECT_BUCKETS(entry_t) \
+        (sizeof(struct direct_storage) / (sizeof(entry_t) + sizeof(dib_raw_t)))
+
+/* We should be able to store at least one entry directly. */
+assert_cc(DIRECT_BUCKETS(struct ordered_hashmap_entry) >= 1);
+
+/* We have 3 bits for n_direct_entries. */
+assert_cc(DIRECT_BUCKETS(struct set_entry) < (1 << 3));
+
+/* Hashmaps with directly stored entries all use this shared hash key.
+ * It's no big deal if the key is guessed, because there can be only
+ * a handful of directly stored entries in a hashmap. When a hashmap
+ * outgrows direct storage, it gets its own key for indirect storage. */
+static uint8_t shared_hash_key[HASH_KEY_SIZE];
+static bool shared_hash_key_initialized;
+
+/* Fields that all hashmap/set types must have */
+struct HashmapBase {
+        const struct hash_ops *hash_ops;  /* hash and compare ops to use */
+
+        union _packed_ {
+                struct indirect_storage indirect; /* if  has_indirect */
+                struct direct_storage direct;     /* if !has_indirect */
+        };
+
+        enum HashmapType type:2;     /* HASHMAP_TYPE_* */
+        bool has_indirect:1;         /* whether indirect storage is used */
+        unsigned n_direct_entries:3; /* Number of entries in direct storage.
+                                      * Only valid if !has_indirect. */
+        bool from_pool:1;            /* whether was allocated from mempool */
+        bool dirty:1;                /* whether dirtied since last iterated_cache_get() */
+        bool cached:1;               /* whether this hashmap is being cached */
+        HASHMAP_DEBUG_FIELDS         /* optional hashmap_debug_info */
+};
+
+/* Specific hash types
+ * HashmapBase must be at the beginning of each hashmap struct. */
+
+struct Hashmap {
+        struct HashmapBase b;
+};
+
+struct OrderedHashmap {
+        struct HashmapBase b;
+        unsigned iterate_list_head, iterate_list_tail;
+};
+
+struct Set {
+        struct HashmapBase b;
+};
+
+typedef struct CacheMem {
+        const void **ptr;
+        size_t n_populated, n_allocated;
+        bool active:1;
+} CacheMem;
+
+struct IteratedCache {
+        HashmapBase *hashmap;
+        CacheMem keys, values;
+};
+
+DEFINE_MEMPOOL(hashmap_pool,         Hashmap,        8);
+DEFINE_MEMPOOL(ordered_hashmap_pool, OrderedHashmap, 8);
+/* No need for a separate Set pool */
+assert_cc(sizeof(Hashmap) == sizeof(Set));
+
+struct hashmap_type_info {
+        size_t head_size;
+        size_t entry_size;
+        struct mempool *mempool;
+        unsigned n_direct_buckets;
+};
+
+static const struct hashmap_type_info hashmap_type_info[_HASHMAP_TYPE_MAX] = {
+        [HASHMAP_TYPE_PLAIN] = {
+                .head_size        = sizeof(Hashmap),
+                .entry_size       = sizeof(struct plain_hashmap_entry),
+                .mempool          = &hashmap_pool,
+                .n_direct_buckets = DIRECT_BUCKETS(struct plain_hashmap_entry),
+        },
+        [HASHMAP_TYPE_ORDERED] = {
+                .head_size        = sizeof(OrderedHashmap),
+                .entry_size       = sizeof(struct ordered_hashmap_entry),
+                .mempool          = &ordered_hashmap_pool,
+                .n_direct_buckets = DIRECT_BUCKETS(struct ordered_hashmap_entry),
+        },
+        [HASHMAP_TYPE_SET] = {
+                .head_size        = sizeof(Set),
+                .entry_size       = sizeof(struct set_entry),
+                .mempool          = &hashmap_pool,
+                .n_direct_buckets = DIRECT_BUCKETS(struct set_entry),
+        },
+};
+
+#if VALGRIND
+_destructor_ static void cleanup_pools(void) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        /* Be nice to valgrind */
+
+        /* The pool is only allocated by the main thread, but the memory can
+         * be passed to other threads. Let's clean up if we are the main thread
+         * and no other threads are live. */
+        if (!is_main_thread())
+                return;
+
+        r = get_proc_field("/proc/self/status", "Threads", WHITESPACE, &t);
+        if (r < 0 || !streq(t, "1"))
+                return;
+
+        mempool_drop(&hashmap_pool);
+        mempool_drop(&ordered_hashmap_pool);
+}
+#endif
+
+static unsigned n_buckets(HashmapBase *h) {
+        return h->has_indirect ? h->indirect.n_buckets
+                               : hashmap_type_info[h->type].n_direct_buckets;
+}
+
+static unsigned n_entries(HashmapBase *h) {
+        return h->has_indirect ? h->indirect.n_entries
+                               : h->n_direct_entries;
+}
+
+static void n_entries_inc(HashmapBase *h) {
+        if (h->has_indirect)
+                h->indirect.n_entries++;
+        else
+                h->n_direct_entries++;
+}
+
+static void n_entries_dec(HashmapBase *h) {
+        if (h->has_indirect)
+                h->indirect.n_entries--;
+        else
+                h->n_direct_entries--;
+}
+
+static void *storage_ptr(HashmapBase *h) {
+        return h->has_indirect ? h->indirect.storage
+                               : h->direct.storage;
+}
+
+static uint8_t *hash_key(HashmapBase *h) {
+        return h->has_indirect ? h->indirect.hash_key
+                               : shared_hash_key;
+}
+
+static unsigned base_bucket_hash(HashmapBase *h, const void *p) {
+        struct siphash state;
+        uint64_t hash;
+
+        siphash24_init(&state, hash_key(h));
+
+        h->hash_ops->hash(p, &state);
+
+        hash = siphash24_finalize(&state);
+
+        return (unsigned) (hash % n_buckets(h));
+}
+#define bucket_hash(h, p) base_bucket_hash(HASHMAP_BASE(h), p)
+
+static void base_set_dirty(HashmapBase *h) {
+        h->dirty = true;
+}
+#define hashmap_set_dirty(h) base_set_dirty(HASHMAP_BASE(h))
+
+static void get_hash_key(uint8_t hash_key[HASH_KEY_SIZE], bool reuse_is_ok) {
+        static uint8_t current[HASH_KEY_SIZE];
+        static bool current_initialized = false;
+
+        /* Returns a hash function key to use. In order to keep things
+         * fast we will not generate a new key each time we allocate a
+         * new hash table. Instead, we'll just reuse the most recently
+         * generated one, except if we never generated one or when we
+         * are rehashing an entire hash table because we reached a
+         * fill level */
+
+        if (!current_initialized || !reuse_is_ok) {
+                random_bytes(current, sizeof(current));
+                current_initialized = true;
+        }
+
+        memcpy(hash_key, current, sizeof(current));
+}
+
+static struct hashmap_base_entry *bucket_at(HashmapBase *h, unsigned idx) {
+        return (struct hashmap_base_entry*)
+                ((uint8_t*) storage_ptr(h) + idx * hashmap_type_info[h->type].entry_size);
+}
+
+static struct plain_hashmap_entry *plain_bucket_at(Hashmap *h, unsigned idx) {
+        return (struct plain_hashmap_entry*) bucket_at(HASHMAP_BASE(h), idx);
+}
+
+static struct ordered_hashmap_entry *ordered_bucket_at(OrderedHashmap *h, unsigned idx) {
+        return (struct ordered_hashmap_entry*) bucket_at(HASHMAP_BASE(h), idx);
+}
+
+static struct set_entry *set_bucket_at(Set *h, unsigned idx) {
+        return (struct set_entry*) bucket_at(HASHMAP_BASE(h), idx);
+}
+
+static struct ordered_hashmap_entry *bucket_at_swap(struct swap_entries *swap, unsigned idx) {
+        return &swap->e[idx - _IDX_SWAP_BEGIN];
+}
+
+/* Returns a pointer to the bucket at index idx.
+ * Understands real indexes and swap indexes, hence "_virtual". */
+static struct hashmap_base_entry *bucket_at_virtual(HashmapBase *h, struct swap_entries *swap,
+                                                    unsigned idx) {
+        if (idx < _IDX_SWAP_BEGIN)
+                return bucket_at(h, idx);
+
+        if (idx < _IDX_SWAP_END)
+                return &bucket_at_swap(swap, idx)->p.b;
+
+        assert_not_reached("Invalid index");
+}
+
+static dib_raw_t *dib_raw_ptr(HashmapBase *h) {
+        return (dib_raw_t*)
+                ((uint8_t*) storage_ptr(h) + hashmap_type_info[h->type].entry_size * n_buckets(h));
+}
+
+static unsigned bucket_distance(HashmapBase *h, unsigned idx, unsigned from) {
+        return idx >= from ? idx - from
+                           : n_buckets(h) + idx - from;
+}
+
+static unsigned bucket_calculate_dib(HashmapBase *h, unsigned idx, dib_raw_t raw_dib) {
+        unsigned initial_bucket;
+
+        if (raw_dib == DIB_RAW_FREE)
+                return DIB_FREE;
+
+        if (_likely_(raw_dib < DIB_RAW_OVERFLOW))
+                return raw_dib;
+
+        /*
+         * Having an overflow DIB value is very unlikely. The hash function
+         * would have to be bad. For example, in a table of size 2^24 filled
+         * to load factor 0.9 the maximum observed DIB is only about 60.
+         * In theory (assuming I used Maxima correctly), for an infinite size
+         * hash table with load factor 0.8 the probability of a given entry
+         * having DIB > 40 is 1.9e-8.
+         * This returns the correct DIB value by recomputing the hash value in
+         * the unlikely case. XXX Hitting this case could be a hint to rehash.
+         */
+        initial_bucket = bucket_hash(h, bucket_at(h, idx)->key);
+        return bucket_distance(h, idx, initial_bucket);
+}
+
+static void bucket_set_dib(HashmapBase *h, unsigned idx, unsigned dib) {
+        dib_raw_ptr(h)[idx] = dib != DIB_FREE ? MIN(dib, DIB_RAW_OVERFLOW) : DIB_RAW_FREE;
+}
+
+static unsigned skip_free_buckets(HashmapBase *h, unsigned idx) {
+        dib_raw_t *dibs;
+
+        dibs = dib_raw_ptr(h);
+
+        for ( ; idx < n_buckets(h); idx++)
+                if (dibs[idx] != DIB_RAW_FREE)
+                        return idx;
+
+        return IDX_NIL;
+}
+
+static void bucket_mark_free(HashmapBase *h, unsigned idx) {
+        memzero(bucket_at(h, idx), hashmap_type_info[h->type].entry_size);
+        bucket_set_dib(h, idx, DIB_FREE);
+}
+
+static void bucket_move_entry(HashmapBase *h, struct swap_entries *swap,
+                              unsigned from, unsigned to) {
+        struct hashmap_base_entry *e_from, *e_to;
+
+        assert(from != to);
+
+        e_from = bucket_at_virtual(h, swap, from);
+        e_to   = bucket_at_virtual(h, swap, to);
+
+        memcpy(e_to, e_from, hashmap_type_info[h->type].entry_size);
+
+        if (h->type == HASHMAP_TYPE_ORDERED) {
+                OrderedHashmap *lh = (OrderedHashmap*) h;
+                struct ordered_hashmap_entry *le, *le_to;
+
+                le_to = (struct ordered_hashmap_entry*) e_to;
+
+                if (le_to->iterate_next != IDX_NIL) {
+                        le = (struct ordered_hashmap_entry*)
+                             bucket_at_virtual(h, swap, le_to->iterate_next);
+                        le->iterate_previous = to;
+                }
+
+                if (le_to->iterate_previous != IDX_NIL) {
+                        le = (struct ordered_hashmap_entry*)
+                             bucket_at_virtual(h, swap, le_to->iterate_previous);
+                        le->iterate_next = to;
+                }
+
+                if (lh->iterate_list_head == from)
+                        lh->iterate_list_head = to;
+                if (lh->iterate_list_tail == from)
+                        lh->iterate_list_tail = to;
+        }
+}
+
+static unsigned next_idx(HashmapBase *h, unsigned idx) {
+        return (idx + 1U) % n_buckets(h);
+}
+
+static unsigned prev_idx(HashmapBase *h, unsigned idx) {
+        return (n_buckets(h) + idx - 1U) % n_buckets(h);
+}
+
+static void *entry_value(HashmapBase *h, struct hashmap_base_entry *e) {
+        switch (h->type) {
+
+        case HASHMAP_TYPE_PLAIN:
+        case HASHMAP_TYPE_ORDERED:
+                return ((struct plain_hashmap_entry*)e)->value;
+
+        case HASHMAP_TYPE_SET:
+                return (void*) e->key;
+
+        default:
+                assert_not_reached("Unknown hashmap type");
+        }
+}
+
+static void base_remove_entry(HashmapBase *h, unsigned idx) {
+        unsigned left, right, prev, dib;
+        dib_raw_t raw_dib, *dibs;
+
+        dibs = dib_raw_ptr(h);
+        assert(dibs[idx] != DIB_RAW_FREE);
+
+#if ENABLE_DEBUG_HASHMAP
+        h->debug.rem_count++;
+        h->debug.last_rem_idx = idx;
+#endif
+
+        left = idx;
+        /* Find the stop bucket ("right"). It is either free or has DIB == 0. */
+        for (right = next_idx(h, left); ; right = next_idx(h, right)) {
+                raw_dib = dibs[right];
+                if (IN_SET(raw_dib, 0, DIB_RAW_FREE))
+                        break;
+
+                /* The buckets are not supposed to be all occupied and with DIB > 0.
+                 * That would mean we could make everyone better off by shifting them
+                 * backward. This scenario is impossible. */
+                assert(left != right);
+        }
+
+        if (h->type == HASHMAP_TYPE_ORDERED) {
+                OrderedHashmap *lh = (OrderedHashmap*) h;
+                struct ordered_hashmap_entry *le = ordered_bucket_at(lh, idx);
+
+                if (le->iterate_next != IDX_NIL)
+                        ordered_bucket_at(lh, le->iterate_next)->iterate_previous = le->iterate_previous;
+                else
+                        lh->iterate_list_tail = le->iterate_previous;
+
+                if (le->iterate_previous != IDX_NIL)
+                        ordered_bucket_at(lh, le->iterate_previous)->iterate_next = le->iterate_next;
+                else
+                        lh->iterate_list_head = le->iterate_next;
+        }
+
+        /* Now shift all buckets in the interval (left, right) one step backwards */
+        for (prev = left, left = next_idx(h, left); left != right;
+             prev = left, left = next_idx(h, left)) {
+                dib = bucket_calculate_dib(h, left, dibs[left]);
+                assert(dib != 0);
+                bucket_move_entry(h, NULL, left, prev);
+                bucket_set_dib(h, prev, dib - 1);
+        }
+
+        bucket_mark_free(h, prev);
+        n_entries_dec(h);
+        base_set_dirty(h);
+}
+#define remove_entry(h, idx) base_remove_entry(HASHMAP_BASE(h), idx)
+
+static unsigned hashmap_iterate_in_insertion_order(OrderedHashmap *h, Iterator *i) {
+        struct ordered_hashmap_entry *e;
+        unsigned idx;
+
+        assert(h);
+        assert(i);
+
+        if (i->idx == IDX_NIL)
+                goto at_end;
+
+        if (i->idx == IDX_FIRST && h->iterate_list_head == IDX_NIL)
+                goto at_end;
+
+        if (i->idx == IDX_FIRST) {
+                idx = h->iterate_list_head;
+                e = ordered_bucket_at(h, idx);
+        } else {
+                idx = i->idx;
+                e = ordered_bucket_at(h, idx);
+                /*
+                 * We allow removing the current entry while iterating, but removal may cause
+                 * a backward shift. The next entry may thus move one bucket to the left.
+                 * To detect when it happens, we remember the key pointer of the entry we were
+                 * going to iterate next. If it does not match, there was a backward shift.
+                 */
+                if (e->p.b.key != i->next_key) {
+                        idx = prev_idx(HASHMAP_BASE(h), idx);
+                        e = ordered_bucket_at(h, idx);
+                }
+                assert(e->p.b.key == i->next_key);
+        }
+
+#if ENABLE_DEBUG_HASHMAP
+        i->prev_idx = idx;
+#endif
+
+        if (e->iterate_next != IDX_NIL) {
+                struct ordered_hashmap_entry *n;
+                i->idx = e->iterate_next;
+                n = ordered_bucket_at(h, i->idx);
+                i->next_key = n->p.b.key;
+        } else
+                i->idx = IDX_NIL;
+
+        return idx;
+
+at_end:
+        i->idx = IDX_NIL;
+        return IDX_NIL;
+}
+
+static unsigned hashmap_iterate_in_internal_order(HashmapBase *h, Iterator *i) {
+        unsigned idx;
+
+        assert(h);
+        assert(i);
+
+        if (i->idx == IDX_NIL)
+                goto at_end;
+
+        if (i->idx == IDX_FIRST) {
+                /* fast forward to the first occupied bucket */
+                if (h->has_indirect) {
+                        i->idx = skip_free_buckets(h, h->indirect.idx_lowest_entry);
+                        h->indirect.idx_lowest_entry = i->idx;
+                } else
+                        i->idx = skip_free_buckets(h, 0);
+
+                if (i->idx == IDX_NIL)
+                        goto at_end;
+        } else {
+                struct hashmap_base_entry *e;
+
+                assert(i->idx > 0);
+
+                e = bucket_at(h, i->idx);
+                /*
+                 * We allow removing the current entry while iterating, but removal may cause
+                 * a backward shift. The next entry may thus move one bucket to the left.
+                 * To detect when it happens, we remember the key pointer of the entry we were
+                 * going to iterate next. If it does not match, there was a backward shift.
+                 */
+                if (e->key != i->next_key)
+                        e = bucket_at(h, --i->idx);
+
+                assert(e->key == i->next_key);
+        }
+
+        idx = i->idx;
+#if ENABLE_DEBUG_HASHMAP
+        i->prev_idx = idx;
+#endif
+
+        i->idx = skip_free_buckets(h, i->idx + 1);
+        if (i->idx != IDX_NIL)
+                i->next_key = bucket_at(h, i->idx)->key;
+        else
+                i->idx = IDX_NIL;
+
+        return idx;
+
+at_end:
+        i->idx = IDX_NIL;
+        return IDX_NIL;
+}
+
+static unsigned hashmap_iterate_entry(HashmapBase *h, Iterator *i) {
+        if (!h) {
+                i->idx = IDX_NIL;
+                return IDX_NIL;
+        }
+
+#if ENABLE_DEBUG_HASHMAP
+        if (i->idx == IDX_FIRST) {
+                i->put_count = h->debug.put_count;
+                i->rem_count = h->debug.rem_count;
+        } else {
+                /* While iterating, must not add any new entries */
+                assert(i->put_count == h->debug.put_count);
+                /* ... or remove entries other than the current one */
+                assert(i->rem_count == h->debug.rem_count ||
+                       (i->rem_count == h->debug.rem_count - 1 &&
+                        i->prev_idx == h->debug.last_rem_idx));
+                /* Reset our removals counter */
+                i->rem_count = h->debug.rem_count;
+        }
+#endif
+
+        return h->type == HASHMAP_TYPE_ORDERED ? hashmap_iterate_in_insertion_order((OrderedHashmap*) h, i)
+                                               : hashmap_iterate_in_internal_order(h, i);
+}
+
+bool internal_hashmap_iterate(HashmapBase *h, Iterator *i, void **value, const void **key) {
+        struct hashmap_base_entry *e;
+        void *data;
+        unsigned idx;
+
+        idx = hashmap_iterate_entry(h, i);
+        if (idx == IDX_NIL) {
+                if (value)
+                        *value = NULL;
+                if (key)
+                        *key = NULL;
+
+                return false;
+        }
+
+        e = bucket_at(h, idx);
+        data = entry_value(h, e);
+        if (value)
+                *value = data;
+        if (key)
+                *key = e->key;
+
+        return true;
+}
+
+bool set_iterate(Set *s, Iterator *i, void **value) {
+        return internal_hashmap_iterate(HASHMAP_BASE(s), i, value, NULL);
+}
+
+#define HASHMAP_FOREACH_IDX(idx, h, i) \
+        for ((i) = ITERATOR_FIRST, (idx) = hashmap_iterate_entry((h), &(i)); \
+             (idx != IDX_NIL); \
+             (idx) = hashmap_iterate_entry((h), &(i)))
+
+IteratedCache *internal_hashmap_iterated_cache_new(HashmapBase *h) {
+        IteratedCache *cache;
+
+        assert(h);
+        assert(!h->cached);
+
+        if (h->cached)
+                return NULL;
+
+        cache = new0(IteratedCache, 1);
+        if (!cache)
+                return NULL;
+
+        cache->hashmap = h;
+        h->cached = true;
+
+        return cache;
+}
+
+static void reset_direct_storage(HashmapBase *h) {
+        const struct hashmap_type_info *hi = &hashmap_type_info[h->type];
+        void *p;
+
+        assert(!h->has_indirect);
+
+        p = mempset(h->direct.storage, 0, hi->entry_size * hi->n_direct_buckets);
+        memset(p, DIB_RAW_INIT, sizeof(dib_raw_t) * hi->n_direct_buckets);
+}
+
+static struct HashmapBase *hashmap_base_new(const struct hash_ops *hash_ops, enum HashmapType type HASHMAP_DEBUG_PARAMS) {
+        HashmapBase *h;
+        const struct hashmap_type_info *hi = &hashmap_type_info[type];
+        bool up;
+
+        up = mempool_enabled();
+
+        h = up ? mempool_alloc0_tile(hi->mempool) : malloc0(hi->head_size);
+        if (!h)
+                return NULL;
+
+        h->type = type;
+        h->from_pool = up;
+        h->hash_ops = hash_ops ?: &trivial_hash_ops;
+
+        if (type == HASHMAP_TYPE_ORDERED) {
+                OrderedHashmap *lh = (OrderedHashmap*)h;
+                lh->iterate_list_head = lh->iterate_list_tail = IDX_NIL;
+        }
+
+        reset_direct_storage(h);
+
+        if (!shared_hash_key_initialized) {
+                random_bytes(shared_hash_key, sizeof(shared_hash_key));
+                shared_hash_key_initialized= true;
+        }
+
+#if ENABLE_DEBUG_HASHMAP
+        h->debug.func = func;
+        h->debug.file = file;
+        h->debug.line = line;
+        assert_se(pthread_mutex_lock(&hashmap_debug_list_mutex) == 0);
+        LIST_PREPEND(debug_list, hashmap_debug_list, &h->debug);
+        assert_se(pthread_mutex_unlock(&hashmap_debug_list_mutex) == 0);
+#endif
+
+        return h;
+}
+
+Hashmap *internal_hashmap_new(const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS) {
+        return (Hashmap*)        hashmap_base_new(hash_ops, HASHMAP_TYPE_PLAIN HASHMAP_DEBUG_PASS_ARGS);
+}
+
+OrderedHashmap *internal_ordered_hashmap_new(const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS) {
+        return (OrderedHashmap*) hashmap_base_new(hash_ops, HASHMAP_TYPE_ORDERED HASHMAP_DEBUG_PASS_ARGS);
+}
+
+Set *internal_set_new(const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS) {
+        return (Set*)            hashmap_base_new(hash_ops, HASHMAP_TYPE_SET HASHMAP_DEBUG_PASS_ARGS);
+}
+
+static int hashmap_base_ensure_allocated(HashmapBase **h, const struct hash_ops *hash_ops,
+                                         enum HashmapType type HASHMAP_DEBUG_PARAMS) {
+        HashmapBase *q;
+
+        assert(h);
+
+        if (*h)
+                return 0;
+
+        q = hashmap_base_new(hash_ops, type HASHMAP_DEBUG_PASS_ARGS);
+        if (!q)
+                return -ENOMEM;
+
+        *h = q;
+        return 0;
+}
+
+int internal_hashmap_ensure_allocated(Hashmap **h, const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS) {
+        return hashmap_base_ensure_allocated((HashmapBase**)h, hash_ops, HASHMAP_TYPE_PLAIN HASHMAP_DEBUG_PASS_ARGS);
+}
+
+int internal_ordered_hashmap_ensure_allocated(OrderedHashmap **h, const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS) {
+        return hashmap_base_ensure_allocated((HashmapBase**)h, hash_ops, HASHMAP_TYPE_ORDERED HASHMAP_DEBUG_PASS_ARGS);
+}
+
+int internal_set_ensure_allocated(Set **s, const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS) {
+        return hashmap_base_ensure_allocated((HashmapBase**)s, hash_ops, HASHMAP_TYPE_SET HASHMAP_DEBUG_PASS_ARGS);
+}
+
+static void hashmap_free_no_clear(HashmapBase *h) {
+        assert(!h->has_indirect);
+        assert(h->n_direct_entries == 0);
+
+#if ENABLE_DEBUG_HASHMAP
+        assert_se(pthread_mutex_lock(&hashmap_debug_list_mutex) == 0);
+        LIST_REMOVE(debug_list, hashmap_debug_list, &h->debug);
+        assert_se(pthread_mutex_unlock(&hashmap_debug_list_mutex) == 0);
+#endif
+
+        if (h->from_pool) {
+                /* Ensure that the object didn't get migrated between threads. */
+                assert_se(is_main_thread());
+                mempool_free_tile(hashmap_type_info[h->type].mempool, h);
+        } else
+                free(h);
+}
+
+HashmapBase *internal_hashmap_free(HashmapBase *h, free_func_t default_free_key, free_func_t default_free_value) {
+        if (h) {
+                internal_hashmap_clear(h, default_free_key, default_free_value);
+                hashmap_free_no_clear(h);
+        }
+
+        return NULL;
+}
+
+void internal_hashmap_clear(HashmapBase *h, free_func_t default_free_key, free_func_t default_free_value) {
+        free_func_t free_key, free_value;
+        if (!h)
+                return;
+
+        free_key = h->hash_ops->free_key ?: default_free_key;
+        free_value = h->hash_ops->free_value ?: default_free_value;
+
+        if (free_key || free_value) {
+
+                /* If destructor calls are defined, let's destroy things defensively: let's take the item out of the
+                 * hash table, and only then call the destructor functions. If these destructors then try to unregister
+                 * themselves from our hash table a second time, the entry is already gone. */
+
+                while (internal_hashmap_size(h) > 0) {
+                        void *k = NULL;
+                        void *v;
+
+                        v = internal_hashmap_first_key_and_value(h, true, &k);
+
+                        if (free_key)
+                                free_key(k);
+
+                        if (free_value)
+                                free_value(v);
+                }
+        }
+
+        if (h->has_indirect) {
+                free(h->indirect.storage);
+                h->has_indirect = false;
+        }
+
+        h->n_direct_entries = 0;
+        reset_direct_storage(h);
+
+        if (h->type == HASHMAP_TYPE_ORDERED) {
+                OrderedHashmap *lh = (OrderedHashmap*) h;
+                lh->iterate_list_head = lh->iterate_list_tail = IDX_NIL;
+        }
+
+        base_set_dirty(h);
+}
+
+static int resize_buckets(HashmapBase *h, unsigned entries_add);
+
+/*
+ * Finds an empty bucket to put an entry into, starting the scan at 'idx'.
+ * Performs Robin Hood swaps as it goes. The entry to put must be placed
+ * by the caller into swap slot IDX_PUT.
+ * If used for in-place resizing, may leave a displaced entry in swap slot
+ * IDX_PUT. Caller must rehash it next.
+ * Returns: true if it left a displaced entry to rehash next in IDX_PUT,
+ *          false otherwise.
+ */
+static bool hashmap_put_robin_hood(HashmapBase *h, unsigned idx,
+                                   struct swap_entries *swap) {
+        dib_raw_t raw_dib, *dibs;
+        unsigned dib, distance;
+
+#if ENABLE_DEBUG_HASHMAP
+        h->debug.put_count++;
+#endif
+
+        dibs = dib_raw_ptr(h);
+
+        for (distance = 0; ; distance++) {
+                raw_dib = dibs[idx];
+                if (IN_SET(raw_dib, DIB_RAW_FREE, DIB_RAW_REHASH)) {
+                        if (raw_dib == DIB_RAW_REHASH)
+                                bucket_move_entry(h, swap, idx, IDX_TMP);
+
+                        if (h->has_indirect && h->indirect.idx_lowest_entry > idx)
+                                h->indirect.idx_lowest_entry = idx;
+
+                        bucket_set_dib(h, idx, distance);
+                        bucket_move_entry(h, swap, IDX_PUT, idx);
+                        if (raw_dib == DIB_RAW_REHASH) {
+                                bucket_move_entry(h, swap, IDX_TMP, IDX_PUT);
+                                return true;
+                        }
+
+                        return false;
+                }
+
+                dib = bucket_calculate_dib(h, idx, raw_dib);
+
+                if (dib < distance) {
+                        /* Found a wealthier entry. Go Robin Hood! */
+                        bucket_set_dib(h, idx, distance);
+
+                        /* swap the entries */
+                        bucket_move_entry(h, swap, idx, IDX_TMP);
+                        bucket_move_entry(h, swap, IDX_PUT, idx);
+                        bucket_move_entry(h, swap, IDX_TMP, IDX_PUT);
+
+                        distance = dib;
+                }
+
+                idx = next_idx(h, idx);
+        }
+}
+
+/*
+ * Puts an entry into a hashmap, boldly - no check whether key already exists.
+ * The caller must place the entry (only its key and value, not link indexes)
+ * in swap slot IDX_PUT.
+ * Caller must ensure: the key does not exist yet in the hashmap.
+ *                     that resize is not needed if !may_resize.
+ * Returns: 1 if entry was put successfully.
+ *          -ENOMEM if may_resize==true and resize failed with -ENOMEM.
+ *          Cannot return -ENOMEM if !may_resize.
+ */
+static int hashmap_base_put_boldly(HashmapBase *h, unsigned idx,
+                                   struct swap_entries *swap, bool may_resize) {
+        struct ordered_hashmap_entry *new_entry;
+        int r;
+
+        assert(idx < n_buckets(h));
+
+        new_entry = bucket_at_swap(swap, IDX_PUT);
+
+        if (may_resize) {
+                r = resize_buckets(h, 1);
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        idx = bucket_hash(h, new_entry->p.b.key);
+        }
+        assert(n_entries(h) < n_buckets(h));
+
+        if (h->type == HASHMAP_TYPE_ORDERED) {
+                OrderedHashmap *lh = (OrderedHashmap*) h;
+
+                new_entry->iterate_next = IDX_NIL;
+                new_entry->iterate_previous = lh->iterate_list_tail;
+
+                if (lh->iterate_list_tail != IDX_NIL) {
+                        struct ordered_hashmap_entry *old_tail;
+
+                        old_tail = ordered_bucket_at(lh, lh->iterate_list_tail);
+                        assert(old_tail->iterate_next == IDX_NIL);
+                        old_tail->iterate_next = IDX_PUT;
+                }
+
+                lh->iterate_list_tail = IDX_PUT;
+                if (lh->iterate_list_head == IDX_NIL)
+                        lh->iterate_list_head = IDX_PUT;
+        }
+
+        assert_se(hashmap_put_robin_hood(h, idx, swap) == false);
+
+        n_entries_inc(h);
+#if ENABLE_DEBUG_HASHMAP
+        h->debug.max_entries = MAX(h->debug.max_entries, n_entries(h));
+#endif
+
+        base_set_dirty(h);
+
+        return 1;
+}
+#define hashmap_put_boldly(h, idx, swap, may_resize) \
+        hashmap_base_put_boldly(HASHMAP_BASE(h), idx, swap, may_resize)
+
+/*
+ * Returns 0 if resize is not needed.
+ *         1 if successfully resized.
+ *         -ENOMEM on allocation failure.
+ */
+static int resize_buckets(HashmapBase *h, unsigned entries_add) {
+        struct swap_entries swap;
+        void *new_storage;
+        dib_raw_t *old_dibs, *new_dibs;
+        const struct hashmap_type_info *hi;
+        unsigned idx, optimal_idx;
+        unsigned old_n_buckets, new_n_buckets, n_rehashed, new_n_entries;
+        uint8_t new_shift;
+        bool rehash_next;
+
+        assert(h);
+
+        hi = &hashmap_type_info[h->type];
+        new_n_entries = n_entries(h) + entries_add;
+
+        /* overflow? */
+        if (_unlikely_(new_n_entries < entries_add))
+                return -ENOMEM;
+
+        /* For direct storage we allow 100% load, because it's tiny. */
+        if (!h->has_indirect && new_n_entries <= hi->n_direct_buckets)
+                return 0;
+
+        /*
+         * Load factor = n/m = 1 - (1/INV_KEEP_FREE).
+         * From it follows: m = n + n/(INV_KEEP_FREE - 1)
+         */
+        new_n_buckets = new_n_entries + new_n_entries / (INV_KEEP_FREE - 1);
+        /* overflow? */
+        if (_unlikely_(new_n_buckets < new_n_entries))
+                return -ENOMEM;
+
+        if (_unlikely_(new_n_buckets > UINT_MAX / (hi->entry_size + sizeof(dib_raw_t))))
+                return -ENOMEM;
+
+        old_n_buckets = n_buckets(h);
+
+        if (_likely_(new_n_buckets <= old_n_buckets))
+                return 0;
+
+        new_shift = log2u_round_up(MAX(
+                        new_n_buckets * (hi->entry_size + sizeof(dib_raw_t)),
+                        2 * sizeof(struct direct_storage)));
+
+        /* Realloc storage (buckets and DIB array). */
+        new_storage = realloc(h->has_indirect ? h->indirect.storage : NULL,
+                              1U << new_shift);
+        if (!new_storage)
+                return -ENOMEM;
+
+        /* Must upgrade direct to indirect storage. */
+        if (!h->has_indirect) {
+                memcpy(new_storage, h->direct.storage,
+                       old_n_buckets * (hi->entry_size + sizeof(dib_raw_t)));
+                h->indirect.n_entries = h->n_direct_entries;
+                h->indirect.idx_lowest_entry = 0;
+                h->n_direct_entries = 0;
+        }
+
+        /* Get a new hash key. If we've just upgraded to indirect storage,
+         * allow reusing a previously generated key. It's still a different key
+         * from the shared one that we used for direct storage. */
+        get_hash_key(h->indirect.hash_key, !h->has_indirect);
+
+        h->has_indirect = true;
+        h->indirect.storage = new_storage;
+        h->indirect.n_buckets = (1U << new_shift) /
+                                (hi->entry_size + sizeof(dib_raw_t));
+
+        old_dibs = (dib_raw_t*)((uint8_t*) new_storage + hi->entry_size * old_n_buckets);
+        new_dibs = dib_raw_ptr(h);
+
+        /*
+         * Move the DIB array to the new place, replacing valid DIB values with
+         * DIB_RAW_REHASH to indicate all of the used buckets need rehashing.
+         * Note: Overlap is not possible, because we have at least doubled the
+         * number of buckets and dib_raw_t is smaller than any entry type.
+         */
+        for (idx = 0; idx < old_n_buckets; idx++) {
+                assert(old_dibs[idx] != DIB_RAW_REHASH);
+                new_dibs[idx] = old_dibs[idx] == DIB_RAW_FREE ? DIB_RAW_FREE
+                                                              : DIB_RAW_REHASH;
+        }
+
+        /* Zero the area of newly added entries (including the old DIB area) */
+        memzero(bucket_at(h, old_n_buckets),
+               (n_buckets(h) - old_n_buckets) * hi->entry_size);
+
+        /* The upper half of the new DIB array needs initialization */
+        memset(&new_dibs[old_n_buckets], DIB_RAW_INIT,
+               (n_buckets(h) - old_n_buckets) * sizeof(dib_raw_t));
+
+        /* Rehash entries that need it */
+        n_rehashed = 0;
+        for (idx = 0; idx < old_n_buckets; idx++) {
+                if (new_dibs[idx] != DIB_RAW_REHASH)
+                        continue;
+
+                optimal_idx = bucket_hash(h, bucket_at(h, idx)->key);
+
+                /*
+                 * Not much to do if by luck the entry hashes to its current
+                 * location. Just set its DIB.
+                 */
+                if (optimal_idx == idx) {
+                        new_dibs[idx] = 0;
+                        n_rehashed++;
+                        continue;
+                }
+
+                new_dibs[idx] = DIB_RAW_FREE;
+                bucket_move_entry(h, &swap, idx, IDX_PUT);
+                /* bucket_move_entry does not clear the source */
+                memzero(bucket_at(h, idx), hi->entry_size);
+
+                do {
+                        /*
+                         * Find the new bucket for the current entry. This may make
+                         * another entry homeless and load it into IDX_PUT.
+                         */
+                        rehash_next = hashmap_put_robin_hood(h, optimal_idx, &swap);
+                        n_rehashed++;
+
+                        /* Did the current entry displace another one? */
+                        if (rehash_next)
+                                optimal_idx = bucket_hash(h, bucket_at_swap(&swap, IDX_PUT)->p.b.key);
+                } while (rehash_next);
+        }
+
+        assert(n_rehashed == n_entries(h));
+
+        return 1;
+}
+
+/*
+ * Finds an entry with a matching key
+ * Returns: index of the found entry, or IDX_NIL if not found.
+ */
+static unsigned base_bucket_scan(HashmapBase *h, unsigned idx, const void *key) {
+        struct hashmap_base_entry *e;
+        unsigned dib, distance;
+        dib_raw_t *dibs = dib_raw_ptr(h);
+
+        assert(idx < n_buckets(h));
+
+        for (distance = 0; ; distance++) {
+                if (dibs[idx] == DIB_RAW_FREE)
+                        return IDX_NIL;
+
+                dib = bucket_calculate_dib(h, idx, dibs[idx]);
+
+                if (dib < distance)
+                        return IDX_NIL;
+                if (dib == distance) {
+                        e = bucket_at(h, idx);
+                        if (h->hash_ops->compare(e->key, key) == 0)
+                                return idx;
+                }
+
+                idx = next_idx(h, idx);
+        }
+}
+#define bucket_scan(h, idx, key) base_bucket_scan(HASHMAP_BASE(h), idx, key)
+
+int hashmap_put(Hashmap *h, const void *key, void *value) {
+        struct swap_entries swap;
+        struct plain_hashmap_entry *e;
+        unsigned hash, idx;
+
+        assert(h);
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx != IDX_NIL) {
+                e = plain_bucket_at(h, idx);
+                if (e->value == value)
+                        return 0;
+                return -EEXIST;
+        }
+
+        e = &bucket_at_swap(&swap, IDX_PUT)->p;
+        e->b.key = key;
+        e->value = value;
+        return hashmap_put_boldly(h, hash, &swap, true);
+}
+
+int set_put(Set *s, const void *key) {
+        struct swap_entries swap;
+        struct hashmap_base_entry *e;
+        unsigned hash, idx;
+
+        assert(s);
+
+        hash = bucket_hash(s, key);
+        idx = bucket_scan(s, hash, key);
+        if (idx != IDX_NIL)
+                return 0;
+
+        e = &bucket_at_swap(&swap, IDX_PUT)->p.b;
+        e->key = key;
+        return hashmap_put_boldly(s, hash, &swap, true);
+}
+
+int hashmap_replace(Hashmap *h, const void *key, void *value) {
+        struct swap_entries swap;
+        struct plain_hashmap_entry *e;
+        unsigned hash, idx;
+
+        assert(h);
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx != IDX_NIL) {
+                e = plain_bucket_at(h, idx);
+#if ENABLE_DEBUG_HASHMAP
+                /* Although the key is equal, the key pointer may have changed,
+                 * and this would break our assumption for iterating. So count
+                 * this operation as incompatible with iteration. */
+                if (e->b.key != key) {
+                        h->b.debug.put_count++;
+                        h->b.debug.rem_count++;
+                        h->b.debug.last_rem_idx = idx;
+                }
+#endif
+                e->b.key = key;
+                e->value = value;
+                hashmap_set_dirty(h);
+
+                return 0;
+        }
+
+        e = &bucket_at_swap(&swap, IDX_PUT)->p;
+        e->b.key = key;
+        e->value = value;
+        return hashmap_put_boldly(h, hash, &swap, true);
+}
+
+int hashmap_update(Hashmap *h, const void *key, void *value) {
+        struct plain_hashmap_entry *e;
+        unsigned hash, idx;
+
+        assert(h);
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx == IDX_NIL)
+                return -ENOENT;
+
+        e = plain_bucket_at(h, idx);
+        e->value = value;
+        hashmap_set_dirty(h);
+
+        return 0;
+}
+
+void *internal_hashmap_get(HashmapBase *h, const void *key) {
+        struct hashmap_base_entry *e;
+        unsigned hash, idx;
+
+        if (!h)
+                return NULL;
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx == IDX_NIL)
+                return NULL;
+
+        e = bucket_at(h, idx);
+        return entry_value(h, e);
+}
+
+void *hashmap_get2(Hashmap *h, const void *key, void **key2) {
+        struct plain_hashmap_entry *e;
+        unsigned hash, idx;
+
+        if (!h)
+                return NULL;
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx == IDX_NIL)
+                return NULL;
+
+        e = plain_bucket_at(h, idx);
+        if (key2)
+                *key2 = (void*) e->b.key;
+
+        return e->value;
+}
+
+bool internal_hashmap_contains(HashmapBase *h, const void *key) {
+        unsigned hash;
+
+        if (!h)
+                return false;
+
+        hash = bucket_hash(h, key);
+        return bucket_scan(h, hash, key) != IDX_NIL;
+}
+
+void *internal_hashmap_remove(HashmapBase *h, const void *key) {
+        struct hashmap_base_entry *e;
+        unsigned hash, idx;
+        void *data;
+
+        if (!h)
+                return NULL;
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx == IDX_NIL)
+                return NULL;
+
+        e = bucket_at(h, idx);
+        data = entry_value(h, e);
+        remove_entry(h, idx);
+
+        return data;
+}
+
+void *hashmap_remove2(Hashmap *h, const void *key, void **rkey) {
+        struct plain_hashmap_entry *e;
+        unsigned hash, idx;
+        void *data;
+
+        if (!h) {
+                if (rkey)
+                        *rkey = NULL;
+                return NULL;
+        }
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx == IDX_NIL) {
+                if (rkey)
+                        *rkey = NULL;
+                return NULL;
+        }
+
+        e = plain_bucket_at(h, idx);
+        data = e->value;
+        if (rkey)
+                *rkey = (void*) e->b.key;
+
+        remove_entry(h, idx);
+
+        return data;
+}
+
+int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value) {
+        struct swap_entries swap;
+        struct plain_hashmap_entry *e;
+        unsigned old_hash, new_hash, idx;
+
+        if (!h)
+                return -ENOENT;
+
+        old_hash = bucket_hash(h, old_key);
+        idx = bucket_scan(h, old_hash, old_key);
+        if (idx == IDX_NIL)
+                return -ENOENT;
+
+        new_hash = bucket_hash(h, new_key);
+        if (bucket_scan(h, new_hash, new_key) != IDX_NIL)
+                return -EEXIST;
+
+        remove_entry(h, idx);
+
+        e = &bucket_at_swap(&swap, IDX_PUT)->p;
+        e->b.key = new_key;
+        e->value = value;
+        assert_se(hashmap_put_boldly(h, new_hash, &swap, false) == 1);
+
+        return 0;
+}
+
+int set_remove_and_put(Set *s, const void *old_key, const void *new_key) {
+        struct swap_entries swap;
+        struct hashmap_base_entry *e;
+        unsigned old_hash, new_hash, idx;
+
+        if (!s)
+                return -ENOENT;
+
+        old_hash = bucket_hash(s, old_key);
+        idx = bucket_scan(s, old_hash, old_key);
+        if (idx == IDX_NIL)
+                return -ENOENT;
+
+        new_hash = bucket_hash(s, new_key);
+        if (bucket_scan(s, new_hash, new_key) != IDX_NIL)
+                return -EEXIST;
+
+        remove_entry(s, idx);
+
+        e = &bucket_at_swap(&swap, IDX_PUT)->p.b;
+        e->key = new_key;
+        assert_se(hashmap_put_boldly(s, new_hash, &swap, false) == 1);
+
+        return 0;
+}
+
+int hashmap_remove_and_replace(Hashmap *h, const void *old_key, const void *new_key, void *value) {
+        struct swap_entries swap;
+        struct plain_hashmap_entry *e;
+        unsigned old_hash, new_hash, idx_old, idx_new;
+
+        if (!h)
+                return -ENOENT;
+
+        old_hash = bucket_hash(h, old_key);
+        idx_old = bucket_scan(h, old_hash, old_key);
+        if (idx_old == IDX_NIL)
+                return -ENOENT;
+
+        old_key = bucket_at(HASHMAP_BASE(h), idx_old)->key;
+
+        new_hash = bucket_hash(h, new_key);
+        idx_new = bucket_scan(h, new_hash, new_key);
+        if (idx_new != IDX_NIL)
+                if (idx_old != idx_new) {
+                        remove_entry(h, idx_new);
+                        /* Compensate for a possible backward shift. */
+                        if (old_key != bucket_at(HASHMAP_BASE(h), idx_old)->key)
+                                idx_old = prev_idx(HASHMAP_BASE(h), idx_old);
+                        assert(old_key == bucket_at(HASHMAP_BASE(h), idx_old)->key);
+                }
+
+        remove_entry(h, idx_old);
+
+        e = &bucket_at_swap(&swap, IDX_PUT)->p;
+        e->b.key = new_key;
+        e->value = value;
+        assert_se(hashmap_put_boldly(h, new_hash, &swap, false) == 1);
+
+        return 0;
+}
+
+void *internal_hashmap_remove_value(HashmapBase *h, const void *key, void *value) {
+        struct hashmap_base_entry *e;
+        unsigned hash, idx;
+
+        if (!h)
+                return NULL;
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx == IDX_NIL)
+                return NULL;
+
+        e = bucket_at(h, idx);
+        if (entry_value(h, e) != value)
+                return NULL;
+
+        remove_entry(h, idx);
+
+        return value;
+}
+
+static unsigned find_first_entry(HashmapBase *h) {
+        Iterator i = ITERATOR_FIRST;
+
+        if (!h || !n_entries(h))
+                return IDX_NIL;
+
+        return hashmap_iterate_entry(h, &i);
+}
+
+void *internal_hashmap_first_key_and_value(HashmapBase *h, bool remove, void **ret_key) {
+        struct hashmap_base_entry *e;
+        void *key, *data;
+        unsigned idx;
+
+        idx = find_first_entry(h);
+        if (idx == IDX_NIL) {
+                if (ret_key)
+                        *ret_key = NULL;
+                return NULL;
+        }
+
+        e = bucket_at(h, idx);
+        key = (void*) e->key;
+        data = entry_value(h, e);
+
+        if (remove)
+                remove_entry(h, idx);
+
+        if (ret_key)
+                *ret_key = key;
+
+        return data;
+}
+
+unsigned internal_hashmap_size(HashmapBase *h) {
+
+        if (!h)
+                return 0;
+
+        return n_entries(h);
+}
+
+unsigned internal_hashmap_buckets(HashmapBase *h) {
+
+        if (!h)
+                return 0;
+
+        return n_buckets(h);
+}
+
+int internal_hashmap_merge(Hashmap *h, Hashmap *other) {
+        Iterator i;
+        unsigned idx;
+
+        assert(h);
+
+        HASHMAP_FOREACH_IDX(idx, HASHMAP_BASE(other), i) {
+                struct plain_hashmap_entry *pe = plain_bucket_at(other, idx);
+                int r;
+
+                r = hashmap_put(h, pe->b.key, pe->value);
+                if (r < 0 && r != -EEXIST)
+                        return r;
+        }
+
+        return 0;
+}
+
+int set_merge(Set *s, Set *other) {
+        Iterator i;
+        unsigned idx;
+
+        assert(s);
+
+        HASHMAP_FOREACH_IDX(idx, HASHMAP_BASE(other), i) {
+                struct set_entry *se = set_bucket_at(other, idx);
+                int r;
+
+                r = set_put(s, se->b.key);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int internal_hashmap_reserve(HashmapBase *h, unsigned entries_add) {
+        int r;
+
+        assert(h);
+
+        r = resize_buckets(h, entries_add);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+/*
+ * The same as hashmap_merge(), but every new item from other is moved to h.
+ * Keys already in h are skipped and stay in other.
+ * Returns: 0 on success.
+ *          -ENOMEM on alloc failure, in which case no move has been done.
+ */
+int internal_hashmap_move(HashmapBase *h, HashmapBase *other) {
+        struct swap_entries swap;
+        struct hashmap_base_entry *e, *n;
+        Iterator i;
+        unsigned idx;
+        int r;
+
+        assert(h);
+
+        if (!other)
+                return 0;
+
+        assert(other->type == h->type);
+
+        /*
+         * This reserves buckets for the worst case, where none of other's
+         * entries are yet present in h. This is preferable to risking
+         * an allocation failure in the middle of the moving and having to
+         * rollback or return a partial result.
+         */
+        r = resize_buckets(h, n_entries(other));
+        if (r < 0)
+                return r;
+
+        HASHMAP_FOREACH_IDX(idx, other, i) {
+                unsigned h_hash;
+
+                e = bucket_at(other, idx);
+                h_hash = bucket_hash(h, e->key);
+                if (bucket_scan(h, h_hash, e->key) != IDX_NIL)
+                        continue;
+
+                n = &bucket_at_swap(&swap, IDX_PUT)->p.b;
+                n->key = e->key;
+                if (h->type != HASHMAP_TYPE_SET)
+                        ((struct plain_hashmap_entry*) n)->value =
+                                ((struct plain_hashmap_entry*) e)->value;
+                assert_se(hashmap_put_boldly(h, h_hash, &swap, false) == 1);
+
+                remove_entry(other, idx);
+        }
+
+        return 0;
+}
+
+int internal_hashmap_move_one(HashmapBase *h, HashmapBase *other, const void *key) {
+        struct swap_entries swap;
+        unsigned h_hash, other_hash, idx;
+        struct hashmap_base_entry *e, *n;
+        int r;
+
+        assert(h);
+
+        h_hash = bucket_hash(h, key);
+        if (bucket_scan(h, h_hash, key) != IDX_NIL)
+                return -EEXIST;
+
+        if (!other)
+                return -ENOENT;
+
+        assert(other->type == h->type);
+
+        other_hash = bucket_hash(other, key);
+        idx = bucket_scan(other, other_hash, key);
+        if (idx == IDX_NIL)
+                return -ENOENT;
+
+        e = bucket_at(other, idx);
+
+        n = &bucket_at_swap(&swap, IDX_PUT)->p.b;
+        n->key = e->key;
+        if (h->type != HASHMAP_TYPE_SET)
+                ((struct plain_hashmap_entry*) n)->value =
+                        ((struct plain_hashmap_entry*) e)->value;
+        r = hashmap_put_boldly(h, h_hash, &swap, true);
+        if (r < 0)
+                return r;
+
+        remove_entry(other, idx);
+        return 0;
+}
+
+HashmapBase *internal_hashmap_copy(HashmapBase *h) {
+        HashmapBase *copy;
+        int r;
+
+        assert(h);
+
+        copy = hashmap_base_new(h->hash_ops, h->type  HASHMAP_DEBUG_SRC_ARGS);
+        if (!copy)
+                return NULL;
+
+        switch (h->type) {
+        case HASHMAP_TYPE_PLAIN:
+        case HASHMAP_TYPE_ORDERED:
+                r = hashmap_merge((Hashmap*)copy, (Hashmap*)h);
+                break;
+        case HASHMAP_TYPE_SET:
+                r = set_merge((Set*)copy, (Set*)h);
+                break;
+        default:
+                assert_not_reached("Unknown hashmap type");
+        }
+
+        if (r < 0) {
+                internal_hashmap_free(copy, false, false);
+                return NULL;
+        }
+
+        return copy;
+}
+
+char **internal_hashmap_get_strv(HashmapBase *h) {
+        char **sv;
+        Iterator i;
+        unsigned idx, n;
+
+        sv = new(char*, n_entries(h)+1);
+        if (!sv)
+                return NULL;
+
+        n = 0;
+        HASHMAP_FOREACH_IDX(idx, h, i)
+                sv[n++] = entry_value(h, bucket_at(h, idx));
+        sv[n] = NULL;
+
+        return sv;
+}
+
+void *ordered_hashmap_next(OrderedHashmap *h, const void *key) {
+        struct ordered_hashmap_entry *e;
+        unsigned hash, idx;
+
+        if (!h)
+                return NULL;
+
+        hash = bucket_hash(h, key);
+        idx = bucket_scan(h, hash, key);
+        if (idx == IDX_NIL)
+                return NULL;
+
+        e = ordered_bucket_at(h, idx);
+        if (e->iterate_next == IDX_NIL)
+                return NULL;
+        return ordered_bucket_at(h, e->iterate_next)->p.value;
+}
+
+int set_consume(Set *s, void *value) {
+        int r;
+
+        assert(s);
+        assert(value);
+
+        r = set_put(s, value);
+        if (r <= 0)
+                free(value);
+
+        return r;
+}
+
+int set_put_strdup(Set *s, const char *p) {
+        char *c;
+
+        assert(s);
+        assert(p);
+
+        if (set_contains(s, (char*) p))
+                return 0;
+
+        c = strdup(p);
+        if (!c)
+                return -ENOMEM;
+
+        return set_consume(s, c);
+}
+
+int set_put_strdupv(Set *s, char **l) {
+        int n = 0, r;
+        char **i;
+
+        assert(s);
+
+        STRV_FOREACH(i, l) {
+                r = set_put_strdup(s, *i);
+                if (r < 0)
+                        return r;
+
+                n += r;
+        }
+
+        return n;
+}
+
+int set_put_strsplit(Set *s, const char *v, const char *separators, ExtractFlags flags) {
+        const char *p = v;
+        int r;
+
+        assert(s);
+        assert(v);
+
+        for (;;) {
+                char *word;
+
+                r = extract_first_word(&p, &word, separators, flags);
+                if (r <= 0)
+                        return r;
+
+                r = set_consume(s, word);
+                if (r < 0)
+                        return r;
+        }
+}
+
+/* expand the cachemem if needed, return true if newly (re)activated. */
+static int cachemem_maintain(CacheMem *mem, unsigned size) {
+        assert(mem);
+
+        if (!GREEDY_REALLOC(mem->ptr, mem->n_allocated, size)) {
+                if (size > 0)
+                        return -ENOMEM;
+        }
+
+        if (!mem->active) {
+                mem->active = true;
+                return true;
+        }
+
+        return false;
+}
+
+int iterated_cache_get(IteratedCache *cache, const void ***res_keys, const void ***res_values, unsigned *res_n_entries) {
+        bool sync_keys = false, sync_values = false;
+        unsigned size;
+        int r;
+
+        assert(cache);
+        assert(cache->hashmap);
+
+        size = n_entries(cache->hashmap);
+
+        if (res_keys) {
+                r = cachemem_maintain(&cache->keys, size);
+                if (r < 0)
+                        return r;
+
+                sync_keys = r;
+        } else
+                cache->keys.active = false;
+
+        if (res_values) {
+                r = cachemem_maintain(&cache->values, size);
+                if (r < 0)
+                        return r;
+
+                sync_values = r;
+        } else
+                cache->values.active = false;
+
+        if (cache->hashmap->dirty) {
+                if (cache->keys.active)
+                        sync_keys = true;
+                if (cache->values.active)
+                        sync_values = true;
+
+                cache->hashmap->dirty = false;
+        }
+
+        if (sync_keys || sync_values) {
+                unsigned i, idx;
+                Iterator iter;
+
+                i = 0;
+                HASHMAP_FOREACH_IDX(idx, cache->hashmap, iter) {
+                        struct hashmap_base_entry *e;
+
+                        e = bucket_at(cache->hashmap, idx);
+
+                        if (sync_keys)
+                                cache->keys.ptr[i] = e->key;
+                        if (sync_values)
+                                cache->values.ptr[i] = entry_value(cache->hashmap, e);
+                        i++;
+                }
+        }
+
+        if (res_keys)
+                *res_keys = cache->keys.ptr;
+        if (res_values)
+                *res_values = cache->values.ptr;
+        if (res_n_entries)
+                *res_n_entries = size;
+
+        return 0;
+}
+
+IteratedCache *iterated_cache_free(IteratedCache *cache) {
+        if (cache) {
+                free(cache->keys.ptr);
+                free(cache->values.ptr);
+                free(cache);
+        }
+
+        return NULL;
+}
diff --git a/src/basic/hashmap.h b/src/basic/hashmap.h
new file mode 100644
index 0000000..e16a9f9
--- /dev/null
+++ b/src/basic/hashmap.h
@@ -0,0 +1,429 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+#include "hash-funcs.h"
+#include "macro.h"
+#include "util.h"
+
+/*
+ * A hash table implementation. As a minor optimization a NULL hashmap object
+ * will be treated as empty hashmap for all read operations. That way it is not
+ * necessary to instantiate an object for each Hashmap use.
+ *
+ * If ENABLE_DEBUG_HASHMAP is defined (by configuring with --enable-debug=hashmap),
+ * the implementation will:
+ * - store extra data for debugging and statistics (see tools/gdb-sd_dump_hashmaps.py)
+ * - perform extra checks for invalid use of iterators
+ */
+
+#define HASH_KEY_SIZE 16
+
+typedef void* (*hashmap_destroy_t)(void *p);
+
+/* The base type for all hashmap and set types. Many functions in the
+ * implementation take (HashmapBase*) parameters and are run-time polymorphic,
+ * though the API is not meant to be polymorphic (do not call functions
+ * internal_*() directly). */
+typedef struct HashmapBase HashmapBase;
+
+/* Specific hashmap/set types */
+typedef struct Hashmap Hashmap;               /* Maps keys to values */
+typedef struct OrderedHashmap OrderedHashmap; /* Like Hashmap, but also remembers entry insertion order */
+typedef struct Set Set;                       /* Stores just keys */
+
+typedef struct IteratedCache IteratedCache;   /* Caches the iterated order of one of the above */
+
+/* Ideally the Iterator would be an opaque struct, but it is instantiated
+ * by hashmap users, so the definition has to be here. Do not use its fields
+ * directly. */
+typedef struct {
+        unsigned idx;         /* index of an entry to be iterated next */
+        const void *next_key; /* expected value of that entry's key pointer */
+#if ENABLE_DEBUG_HASHMAP
+        unsigned put_count;   /* hashmap's put_count recorded at start of iteration */
+        unsigned rem_count;   /* hashmap's rem_count in previous iteration */
+        unsigned prev_idx;    /* idx in previous iteration */
+#endif
+} Iterator;
+
+#define _IDX_ITERATOR_FIRST (UINT_MAX - 1)
+#define ITERATOR_FIRST ((Iterator) { .idx = _IDX_ITERATOR_FIRST, .next_key = NULL })
+
+/* Macros for type checking */
+#define PTR_COMPATIBLE_WITH_HASHMAP_BASE(h) \
+        (__builtin_types_compatible_p(typeof(h), HashmapBase*) || \
+         __builtin_types_compatible_p(typeof(h), Hashmap*) || \
+         __builtin_types_compatible_p(typeof(h), OrderedHashmap*) || \
+         __builtin_types_compatible_p(typeof(h), Set*))
+
+#define PTR_COMPATIBLE_WITH_PLAIN_HASHMAP(h) \
+        (__builtin_types_compatible_p(typeof(h), Hashmap*) || \
+         __builtin_types_compatible_p(typeof(h), OrderedHashmap*)) \
+
+#define HASHMAP_BASE(h) \
+        __builtin_choose_expr(PTR_COMPATIBLE_WITH_HASHMAP_BASE(h), \
+                (HashmapBase*)(h), \
+                (void)0)
+
+#define PLAIN_HASHMAP(h) \
+        __builtin_choose_expr(PTR_COMPATIBLE_WITH_PLAIN_HASHMAP(h), \
+                (Hashmap*)(h), \
+                (void)0)
+
+#if ENABLE_DEBUG_HASHMAP
+# define HASHMAP_DEBUG_PARAMS , const char *func, const char *file, int line
+# define HASHMAP_DEBUG_SRC_ARGS   , __func__, __FILE__, __LINE__
+# define HASHMAP_DEBUG_PASS_ARGS   , func, file, line
+#else
+# define HASHMAP_DEBUG_PARAMS
+# define HASHMAP_DEBUG_SRC_ARGS
+# define HASHMAP_DEBUG_PASS_ARGS
+#endif
+
+Hashmap *internal_hashmap_new(const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS);
+OrderedHashmap *internal_ordered_hashmap_new(const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS);
+#define hashmap_new(ops) internal_hashmap_new(ops  HASHMAP_DEBUG_SRC_ARGS)
+#define ordered_hashmap_new(ops) internal_ordered_hashmap_new(ops  HASHMAP_DEBUG_SRC_ARGS)
+
+HashmapBase *internal_hashmap_free(HashmapBase *h, free_func_t default_free_key, free_func_t default_free_value);
+static inline Hashmap *hashmap_free(Hashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), NULL, NULL);
+}
+static inline OrderedHashmap *ordered_hashmap_free(OrderedHashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), NULL, NULL);
+}
+
+static inline Hashmap *hashmap_free_free(Hashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), NULL, free);
+}
+static inline OrderedHashmap *ordered_hashmap_free_free(OrderedHashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), NULL, free);
+}
+
+static inline Hashmap *hashmap_free_free_key(Hashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), free, NULL);
+}
+static inline OrderedHashmap *ordered_hashmap_free_free_key(OrderedHashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), free, NULL);
+}
+
+static inline Hashmap *hashmap_free_free_free(Hashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), free, free);
+}
+static inline OrderedHashmap *ordered_hashmap_free_free_free(OrderedHashmap *h) {
+        return (void*) internal_hashmap_free(HASHMAP_BASE(h), free, free);
+}
+
+IteratedCache *iterated_cache_free(IteratedCache *cache);
+int iterated_cache_get(IteratedCache *cache, const void ***res_keys, const void ***res_values, unsigned *res_n_entries);
+
+HashmapBase *internal_hashmap_copy(HashmapBase *h);
+static inline Hashmap *hashmap_copy(Hashmap *h) {
+        return (Hashmap*) internal_hashmap_copy(HASHMAP_BASE(h));
+}
+static inline OrderedHashmap *ordered_hashmap_copy(OrderedHashmap *h) {
+        return (OrderedHashmap*) internal_hashmap_copy(HASHMAP_BASE(h));
+}
+
+int internal_hashmap_ensure_allocated(Hashmap **h, const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS);
+int internal_ordered_hashmap_ensure_allocated(OrderedHashmap **h, const struct hash_ops *hash_ops  HASHMAP_DEBUG_PARAMS);
+#define hashmap_ensure_allocated(h, ops) internal_hashmap_ensure_allocated(h, ops  HASHMAP_DEBUG_SRC_ARGS)
+#define ordered_hashmap_ensure_allocated(h, ops) internal_ordered_hashmap_ensure_allocated(h, ops  HASHMAP_DEBUG_SRC_ARGS)
+
+IteratedCache *internal_hashmap_iterated_cache_new(HashmapBase *h);
+static inline IteratedCache *hashmap_iterated_cache_new(Hashmap *h) {
+        return (IteratedCache*) internal_hashmap_iterated_cache_new(HASHMAP_BASE(h));
+}
+static inline IteratedCache *ordered_hashmap_iterated_cache_new(OrderedHashmap *h) {
+        return (IteratedCache*) internal_hashmap_iterated_cache_new(HASHMAP_BASE(h));
+}
+
+int hashmap_put(Hashmap *h, const void *key, void *value);
+static inline int ordered_hashmap_put(OrderedHashmap *h, const void *key, void *value) {
+        return hashmap_put(PLAIN_HASHMAP(h), key, value);
+}
+
+int hashmap_update(Hashmap *h, const void *key, void *value);
+static inline int ordered_hashmap_update(OrderedHashmap *h, const void *key, void *value) {
+        return hashmap_update(PLAIN_HASHMAP(h), key, value);
+}
+
+int hashmap_replace(Hashmap *h, const void *key, void *value);
+static inline int ordered_hashmap_replace(OrderedHashmap *h, const void *key, void *value) {
+        return hashmap_replace(PLAIN_HASHMAP(h), key, value);
+}
+
+void *internal_hashmap_get(HashmapBase *h, const void *key);
+static inline void *hashmap_get(Hashmap *h, const void *key) {
+        return internal_hashmap_get(HASHMAP_BASE(h), key);
+}
+static inline void *ordered_hashmap_get(OrderedHashmap *h, const void *key) {
+        return internal_hashmap_get(HASHMAP_BASE(h), key);
+}
+
+void *hashmap_get2(Hashmap *h, const void *key, void **rkey);
+static inline void *ordered_hashmap_get2(OrderedHashmap *h, const void *key, void **rkey) {
+        return hashmap_get2(PLAIN_HASHMAP(h), key, rkey);
+}
+
+bool internal_hashmap_contains(HashmapBase *h, const void *key);
+static inline bool hashmap_contains(Hashmap *h, const void *key) {
+        return internal_hashmap_contains(HASHMAP_BASE(h), key);
+}
+static inline bool ordered_hashmap_contains(OrderedHashmap *h, const void *key) {
+        return internal_hashmap_contains(HASHMAP_BASE(h), key);
+}
+
+void *internal_hashmap_remove(HashmapBase *h, const void *key);
+static inline void *hashmap_remove(Hashmap *h, const void *key) {
+        return internal_hashmap_remove(HASHMAP_BASE(h), key);
+}
+static inline void *ordered_hashmap_remove(OrderedHashmap *h, const void *key) {
+        return internal_hashmap_remove(HASHMAP_BASE(h), key);
+}
+
+void *hashmap_remove2(Hashmap *h, const void *key, void **rkey);
+static inline void *ordered_hashmap_remove2(OrderedHashmap *h, const void *key, void **rkey) {
+        return hashmap_remove2(PLAIN_HASHMAP(h), key, rkey);
+}
+
+void *internal_hashmap_remove_value(HashmapBase *h, const void *key, void *value);
+static inline void *hashmap_remove_value(Hashmap *h, const void *key, void *value) {
+        return internal_hashmap_remove_value(HASHMAP_BASE(h), key, value);
+}
+
+static inline void *ordered_hashmap_remove_value(OrderedHashmap *h, const void *key, void *value) {
+        return hashmap_remove_value(PLAIN_HASHMAP(h), key, value);
+}
+
+int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value);
+static inline int ordered_hashmap_remove_and_put(OrderedHashmap *h, const void *old_key, const void *new_key, void *value) {
+        return hashmap_remove_and_put(PLAIN_HASHMAP(h), old_key, new_key, value);
+}
+
+int hashmap_remove_and_replace(Hashmap *h, const void *old_key, const void *new_key, void *value);
+static inline int ordered_hashmap_remove_and_replace(OrderedHashmap *h, const void *old_key, const void *new_key, void *value) {
+        return hashmap_remove_and_replace(PLAIN_HASHMAP(h), old_key, new_key, value);
+}
+
+/* Since merging data from a OrderedHashmap into a Hashmap or vice-versa
+ * should just work, allow this by having looser type-checking here. */
+int internal_hashmap_merge(Hashmap *h, Hashmap *other);
+#define hashmap_merge(h, other) internal_hashmap_merge(PLAIN_HASHMAP(h), PLAIN_HASHMAP(other))
+#define ordered_hashmap_merge(h, other) hashmap_merge(h, other)
+
+int internal_hashmap_reserve(HashmapBase *h, unsigned entries_add);
+static inline int hashmap_reserve(Hashmap *h, unsigned entries_add) {
+        return internal_hashmap_reserve(HASHMAP_BASE(h), entries_add);
+}
+static inline int ordered_hashmap_reserve(OrderedHashmap *h, unsigned entries_add) {
+        return internal_hashmap_reserve(HASHMAP_BASE(h), entries_add);
+}
+
+int internal_hashmap_move(HashmapBase *h, HashmapBase *other);
+/* Unlike hashmap_merge, hashmap_move does not allow mixing the types. */
+static inline int hashmap_move(Hashmap *h, Hashmap *other) {
+        return internal_hashmap_move(HASHMAP_BASE(h), HASHMAP_BASE(other));
+}
+static inline int ordered_hashmap_move(OrderedHashmap *h, OrderedHashmap *other) {
+        return internal_hashmap_move(HASHMAP_BASE(h), HASHMAP_BASE(other));
+}
+
+int internal_hashmap_move_one(HashmapBase *h, HashmapBase *other, const void *key);
+static inline int hashmap_move_one(Hashmap *h, Hashmap *other, const void *key) {
+        return internal_hashmap_move_one(HASHMAP_BASE(h), HASHMAP_BASE(other), key);
+}
+static inline int ordered_hashmap_move_one(OrderedHashmap *h, OrderedHashmap *other, const void *key) {
+        return internal_hashmap_move_one(HASHMAP_BASE(h), HASHMAP_BASE(other), key);
+}
+
+unsigned internal_hashmap_size(HashmapBase *h) _pure_;
+static inline unsigned hashmap_size(Hashmap *h) {
+        return internal_hashmap_size(HASHMAP_BASE(h));
+}
+static inline unsigned ordered_hashmap_size(OrderedHashmap *h) {
+        return internal_hashmap_size(HASHMAP_BASE(h));
+}
+
+static inline bool hashmap_isempty(Hashmap *h) {
+        return hashmap_size(h) == 0;
+}
+static inline bool ordered_hashmap_isempty(OrderedHashmap *h) {
+        return ordered_hashmap_size(h) == 0;
+}
+
+unsigned internal_hashmap_buckets(HashmapBase *h) _pure_;
+static inline unsigned hashmap_buckets(Hashmap *h) {
+        return internal_hashmap_buckets(HASHMAP_BASE(h));
+}
+static inline unsigned ordered_hashmap_buckets(OrderedHashmap *h) {
+        return internal_hashmap_buckets(HASHMAP_BASE(h));
+}
+
+bool internal_hashmap_iterate(HashmapBase *h, Iterator *i, void **value, const void **key);
+static inline bool hashmap_iterate(Hashmap *h, Iterator *i, void **value, const void **key) {
+        return internal_hashmap_iterate(HASHMAP_BASE(h), i, value, key);
+}
+static inline bool ordered_hashmap_iterate(OrderedHashmap *h, Iterator *i, void **value, const void **key) {
+        return internal_hashmap_iterate(HASHMAP_BASE(h), i, value, key);
+}
+
+void internal_hashmap_clear(HashmapBase *h, free_func_t default_free_key, free_func_t default_free_value);
+static inline void hashmap_clear(Hashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), NULL, NULL);
+}
+static inline void ordered_hashmap_clear(OrderedHashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), NULL, NULL);
+}
+
+static inline void hashmap_clear_free(Hashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), NULL, free);
+}
+static inline void ordered_hashmap_clear_free(OrderedHashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), NULL, free);
+}
+
+static inline void hashmap_clear_free_key(Hashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), free, NULL);
+}
+static inline void ordered_hashmap_clear_free_key(OrderedHashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), free, NULL);
+}
+
+static inline void hashmap_clear_free_free(Hashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), free, free);
+}
+static inline void ordered_hashmap_clear_free_free(OrderedHashmap *h) {
+        internal_hashmap_clear(HASHMAP_BASE(h), free, free);
+}
+
+/*
+ * Note about all *_first*() functions
+ *
+ * For plain Hashmaps and Sets the order of entries is undefined.
+ * The functions find whatever entry is first in the implementation
+ * internal order.
+ *
+ * Only for OrderedHashmaps the order is well defined and finding
+ * the first entry is O(1).
+ */
+
+void *internal_hashmap_first_key_and_value(HashmapBase *h, bool remove, void **ret_key);
+static inline void *hashmap_steal_first_key_and_value(Hashmap *h, void **ret) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), true, ret);
+}
+static inline void *ordered_hashmap_steal_first_key_and_value(OrderedHashmap *h, void **ret) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), true, ret);
+}
+static inline void *hashmap_first_key_and_value(Hashmap *h, void **ret) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), false, ret);
+}
+static inline void *ordered_hashmap_first_key_and_value(OrderedHashmap *h, void **ret) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), false, ret);
+}
+
+static inline void *hashmap_steal_first(Hashmap *h) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), true, NULL);
+}
+static inline void *ordered_hashmap_steal_first(OrderedHashmap *h) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), true, NULL);
+}
+static inline void *hashmap_first(Hashmap *h) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), false, NULL);
+}
+static inline void *ordered_hashmap_first(OrderedHashmap *h) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(h), false, NULL);
+}
+
+static inline void *internal_hashmap_first_key(HashmapBase *h, bool remove) {
+        void *key = NULL;
+
+        (void) internal_hashmap_first_key_and_value(HASHMAP_BASE(h), remove, &key);
+        return key;
+}
+static inline void *hashmap_steal_first_key(Hashmap *h) {
+        return internal_hashmap_first_key(HASHMAP_BASE(h), true);
+}
+static inline void *ordered_hashmap_steal_first_key(OrderedHashmap *h) {
+        return internal_hashmap_first_key(HASHMAP_BASE(h), true);
+}
+static inline void *hashmap_first_key(Hashmap *h) {
+        return internal_hashmap_first_key(HASHMAP_BASE(h), false);
+}
+static inline void *ordered_hashmap_first_key(OrderedHashmap *h) {
+        return internal_hashmap_first_key(HASHMAP_BASE(h), false);
+}
+
+#define hashmap_clear_with_destructor(_s, _f)                   \
+        ({                                                      \
+                void *_item;                                    \
+                while ((_item = hashmap_steal_first(_s)))       \
+                        _f(_item);                              \
+        })
+#define hashmap_free_with_destructor(_s, _f)                    \
+        ({                                                      \
+                hashmap_clear_with_destructor(_s, _f);          \
+                hashmap_free(_s);                               \
+        })
+#define ordered_hashmap_clear_with_destructor(_s, _f)                   \
+        ({                                                              \
+                void *_item;                                            \
+                while ((_item = ordered_hashmap_steal_first(_s)))       \
+                        _f(_item);                                      \
+        })
+#define ordered_hashmap_free_with_destructor(_s, _f)                    \
+        ({                                                              \
+                ordered_hashmap_clear_with_destructor(_s, _f);          \
+                ordered_hashmap_free(_s);                               \
+        })
+
+/* no hashmap_next */
+void *ordered_hashmap_next(OrderedHashmap *h, const void *key);
+
+char **internal_hashmap_get_strv(HashmapBase *h);
+static inline char **hashmap_get_strv(Hashmap *h) {
+        return internal_hashmap_get_strv(HASHMAP_BASE(h));
+}
+static inline char **ordered_hashmap_get_strv(OrderedHashmap *h) {
+        return internal_hashmap_get_strv(HASHMAP_BASE(h));
+}
+
+/*
+ * Hashmaps are iterated in unpredictable order.
+ * OrderedHashmaps are an exception to this. They are iterated in the order
+ * the entries were inserted.
+ * It is safe to remove the current entry.
+ */
+#define HASHMAP_FOREACH(e, h, i) \
+        for ((i) = ITERATOR_FIRST; hashmap_iterate((h), &(i), (void**)&(e), NULL); )
+
+#define ORDERED_HASHMAP_FOREACH(e, h, i) \
+        for ((i) = ITERATOR_FIRST; ordered_hashmap_iterate((h), &(i), (void**)&(e), NULL); )
+
+#define HASHMAP_FOREACH_KEY(e, k, h, i) \
+        for ((i) = ITERATOR_FIRST; hashmap_iterate((h), &(i), (void**)&(e), (const void**) &(k)); )
+
+#define ORDERED_HASHMAP_FOREACH_KEY(e, k, h, i) \
+        for ((i) = ITERATOR_FIRST; ordered_hashmap_iterate((h), &(i), (void**)&(e), (const void**) &(k)); )
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap*, hashmap_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap*, hashmap_free_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(Hashmap*, hashmap_free_free_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedHashmap*, ordered_hashmap_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedHashmap*, ordered_hashmap_free_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedHashmap*, ordered_hashmap_free_free_free);
+
+#define _cleanup_hashmap_free_ _cleanup_(hashmap_freep)
+#define _cleanup_hashmap_free_free_ _cleanup_(hashmap_free_freep)
+#define _cleanup_hashmap_free_free_free_ _cleanup_(hashmap_free_free_freep)
+#define _cleanup_ordered_hashmap_free_ _cleanup_(ordered_hashmap_freep)
+#define _cleanup_ordered_hashmap_free_free_ _cleanup_(ordered_hashmap_free_freep)
+#define _cleanup_ordered_hashmap_free_free_free_ _cleanup_(ordered_hashmap_free_free_freep)
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(IteratedCache*, iterated_cache_free);
+
+#define _cleanup_iterated_cache_free_ _cleanup_(iterated_cache_freep)
diff --git a/src/basic/hexdecoct.c b/src/basic/hexdecoct.c
new file mode 100644
index 0000000..c0f9640
--- /dev/null
+++ b/src/basic/hexdecoct.c
@@ -0,0 +1,819 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "hexdecoct.h"
+#include "macro.h"
+#include "string-util.h"
+#include "util.h"
+
+char octchar(int x) {
+        return '0' + (x & 7);
+}
+
+int unoctchar(char c) {
+
+        if (c >= '0' && c <= '7')
+                return c - '0';
+
+        return -EINVAL;
+}
+
+char decchar(int x) {
+        return '0' + (x % 10);
+}
+
+int undecchar(char c) {
+
+        if (c >= '0' && c <= '9')
+                return c - '0';
+
+        return -EINVAL;
+}
+
+char hexchar(int x) {
+        static const char table[16] = "0123456789abcdef";
+
+        return table[x & 15];
+}
+
+int unhexchar(char c) {
+
+        if (c >= '0' && c <= '9')
+                return c - '0';
+
+        if (c >= 'a' && c <= 'f')
+                return c - 'a' + 10;
+
+        if (c >= 'A' && c <= 'F')
+                return c - 'A' + 10;
+
+        return -EINVAL;
+}
+
+char *hexmem(const void *p, size_t l) {
+        const uint8_t *x;
+        char *r, *z;
+
+        z = r = new(char, l * 2 + 1);
+        if (!r)
+                return NULL;
+
+        for (x = p; x < (const uint8_t*) p + l; x++) {
+                *(z++) = hexchar(*x >> 4);
+                *(z++) = hexchar(*x & 15);
+        }
+
+        *z = 0;
+        return r;
+}
+
+static int unhex_next(const char **p, size_t *l) {
+        int r;
+
+        assert(p);
+        assert(l);
+
+        /* Find the next non-whitespace character, and decode it. We
+         * greedily skip all preceding and all following whitespace. */
+
+        for (;;) {
+                if (*l == 0)
+                        return -EPIPE;
+
+                if (!strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip leading whitespace */
+                (*p)++, (*l)--;
+        }
+
+        r = unhexchar(**p);
+        if (r < 0)
+                return r;
+
+        for (;;) {
+                (*p)++, (*l)--;
+
+                if (*l == 0 || !strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip following whitespace */
+        }
+
+        return r;
+}
+
+int unhexmem(const char *p, size_t l, void **ret, size_t *ret_len) {
+        _cleanup_free_ uint8_t *buf = NULL;
+        const char *x;
+        uint8_t *z;
+
+        assert(ret);
+        assert(ret_len);
+        assert(p || l == 0);
+
+        if (l == (size_t) -1)
+                l = strlen(p);
+
+        /* Note that the calculation of memory size is an upper boundary, as we ignore whitespace while decoding */
+        buf = malloc((l + 1) / 2 + 1);
+        if (!buf)
+                return -ENOMEM;
+
+        for (x = p, z = buf;;) {
+                int a, b;
+
+                a = unhex_next(&x, &l);
+                if (a == -EPIPE) /* End of string */
+                        break;
+                if (a < 0)
+                        return a;
+
+                b = unhex_next(&x, &l);
+                if (b < 0)
+                        return b;
+
+                *(z++) = (uint8_t) a << 4 | (uint8_t) b;
+        }
+
+        *z = 0;
+
+        *ret_len = (size_t) (z - buf);
+        *ret = TAKE_PTR(buf);
+
+        return 0;
+}
+
+/* https://tools.ietf.org/html/rfc4648#section-6
+ * Notice that base32hex differs from base32 in the alphabet it uses.
+ * The distinction is that the base32hex representation preserves the
+ * order of the underlying data when compared as bytestrings, this is
+ * useful when representing NSEC3 hashes, as one can then verify the
+ * order of hashes directly from their representation. */
+char base32hexchar(int x) {
+        static const char table[32] = "0123456789"
+                                      "ABCDEFGHIJKLMNOPQRSTUV";
+
+        return table[x & 31];
+}
+
+int unbase32hexchar(char c) {
+        unsigned offset;
+
+        if (c >= '0' && c <= '9')
+                return c - '0';
+
+        offset = '9' - '0' + 1;
+
+        if (c >= 'A' && c <= 'V')
+                return c - 'A' + offset;
+
+        return -EINVAL;
+}
+
+char *base32hexmem(const void *p, size_t l, bool padding) {
+        char *r, *z;
+        const uint8_t *x;
+        size_t len;
+
+        assert(p || l == 0);
+
+        if (padding)
+                /* five input bytes makes eight output bytes, padding is added so we must round up */
+                len = 8 * (l + 4) / 5;
+        else {
+                /* same, but round down as there is no padding */
+                len = 8 * l / 5;
+
+                switch (l % 5) {
+                case 4:
+                        len += 7;
+                        break;
+                case 3:
+                        len += 5;
+                        break;
+                case 2:
+                        len += 4;
+                        break;
+                case 1:
+                        len += 2;
+                        break;
+                }
+        }
+
+        z = r = malloc(len + 1);
+        if (!r)
+                return NULL;
+
+        for (x = p; x < (const uint8_t*) p + (l / 5) * 5; x += 5) {
+                /* x[0] == XXXXXXXX; x[1] == YYYYYYYY; x[2] == ZZZZZZZZ
+                 * x[3] == QQQQQQQQ; x[4] == WWWWWWWW */
+                *(z++) = base32hexchar(x[0] >> 3);                    /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6);  /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);             /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4);  /* 000YZZZZ */
+                *(z++) = base32hexchar((x[2] & 15) << 1 | x[3] >> 7); /* 000ZZZZQ */
+                *(z++) = base32hexchar((x[3] & 127) >> 2);            /* 000QQQQQ */
+                *(z++) = base32hexchar((x[3] & 3) << 3 | x[4] >> 5);  /* 000QQWWW */
+                *(z++) = base32hexchar((x[4] & 31));                  /* 000WWWWW */
+        }
+
+        switch (l % 5) {
+        case 4:
+                *(z++) = base32hexchar(x[0] >> 3);                    /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6);  /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);             /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4);   /* 000YZZZZ */
+                *(z++) = base32hexchar((x[2] & 15) << 1 | x[3] >> 7); /* 000ZZZZQ */
+                *(z++) = base32hexchar((x[3] & 127) >> 2);            /* 000QQQQQ */
+                *(z++) = base32hexchar((x[3] & 3) << 3);              /* 000QQ000 */
+                if (padding)
+                        *(z++) = '=';
+
+                break;
+
+        case 3:
+                *(z++) = base32hexchar(x[0] >> 3);                   /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6); /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);            /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4 | x[2] >> 4); /* 000YZZZZ */
+                *(z++) = base32hexchar((x[2] & 15) << 1);            /* 000ZZZZ0 */
+                if (padding) {
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                }
+
+                break;
+
+        case 2:
+                *(z++) = base32hexchar(x[0] >> 3);                   /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2 | x[1] >> 6); /* 000XXXYY */
+                *(z++) = base32hexchar((x[1] & 63) >> 1);            /* 000YYYYY */
+                *(z++) = base32hexchar((x[1] & 1) << 4);             /* 000Y0000 */
+                if (padding) {
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                }
+
+                break;
+
+        case 1:
+                *(z++) = base32hexchar(x[0] >> 3);       /* 000XXXXX */
+                *(z++) = base32hexchar((x[0] & 7) << 2); /* 000XXX00 */
+                if (padding) {
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                        *(z++) = '=';
+                }
+
+                break;
+        }
+
+        *z = 0;
+        return r;
+}
+
+int unbase32hexmem(const char *p, size_t l, bool padding, void **mem, size_t *_len) {
+        _cleanup_free_ uint8_t *r = NULL;
+        int a, b, c, d, e, f, g, h;
+        uint8_t *z;
+        const char *x;
+        size_t len;
+        unsigned pad = 0;
+
+        assert(p || l == 0);
+        assert(mem);
+        assert(_len);
+
+        if (l == (size_t) -1)
+                l = strlen(p);
+
+        /* padding ensures any base32hex input has input divisible by 8 */
+        if (padding && l % 8 != 0)
+                return -EINVAL;
+
+        if (padding) {
+                /* strip the padding */
+                while (l > 0 && p[l - 1] == '=' && pad < 7) {
+                        pad++;
+                        l--;
+                }
+        }
+
+        /* a group of eight input bytes needs five output bytes, in case of
+         * padding we need to add some extra bytes */
+        len = (l / 8) * 5;
+
+        switch (l % 8) {
+        case 7:
+                len += 4;
+                break;
+        case 5:
+                len += 3;
+                break;
+        case 4:
+                len += 2;
+                break;
+        case 2:
+                len += 1;
+                break;
+        case 0:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        z = r = malloc(len + 1);
+        if (!r)
+                return -ENOMEM;
+
+        for (x = p; x < p + (l / 8) * 8; x += 8) {
+                /* a == 000XXXXX; b == 000YYYYY; c == 000ZZZZZ; d == 000WWWWW
+                 * e == 000SSSSS; f == 000QQQQQ; g == 000VVVVV; h == 000RRRRR */
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                e = unbase32hexchar(x[4]);
+                if (e < 0)
+                        return -EINVAL;
+
+                f = unbase32hexchar(x[5]);
+                if (f < 0)
+                        return -EINVAL;
+
+                g = unbase32hexchar(x[6]);
+                if (g < 0)
+                        return -EINVAL;
+
+                h = unbase32hexchar(x[7]);
+                if (h < 0)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
+                *(z++) = (uint8_t) e << 7 | (uint8_t) f << 2 | (uint8_t) g >> 3; /* SQQQQQVV */
+                *(z++) = (uint8_t) g << 5 | (uint8_t) h;                         /* VVVRRRRR */
+        }
+
+        switch (l % 8) {
+        case 7:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                e = unbase32hexchar(x[4]);
+                if (e < 0)
+                        return -EINVAL;
+
+                f = unbase32hexchar(x[5]);
+                if (f < 0)
+                        return -EINVAL;
+
+                g = unbase32hexchar(x[6]);
+                if (g < 0)
+                        return -EINVAL;
+
+                /* g == 000VV000 */
+                if (g & 7)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
+                *(z++) = (uint8_t) e << 7 | (uint8_t) f << 2 | (uint8_t) g >> 3; /* SQQQQQVV */
+
+                break;
+        case 5:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                e = unbase32hexchar(x[4]);
+                if (e < 0)
+                        return -EINVAL;
+
+                /* e == 000SSSS0 */
+                if (e & 1)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+                *(z++) = (uint8_t) d << 4 | (uint8_t) e >> 1;                    /* WWWWSSSS */
+
+                break;
+        case 4:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                c = unbase32hexchar(x[2]);
+                if (c < 0)
+                        return -EINVAL;
+
+                d = unbase32hexchar(x[3]);
+                if (d < 0)
+                        return -EINVAL;
+
+                /* d == 000W0000 */
+                if (d & 15)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2;                    /* XXXXXYYY */
+                *(z++) = (uint8_t) b << 6 | (uint8_t) c << 1 | (uint8_t) d >> 4; /* YYZZZZZW */
+
+                break;
+        case 2:
+                a = unbase32hexchar(x[0]);
+                if (a < 0)
+                        return -EINVAL;
+
+                b = unbase32hexchar(x[1]);
+                if (b < 0)
+                        return -EINVAL;
+
+                /* b == 000YYY00 */
+                if (b & 3)
+                        return -EINVAL;
+
+                *(z++) = (uint8_t) a << 3 | (uint8_t) b >> 2; /* XXXXXYYY */
+
+                break;
+        case 0:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        *z = 0;
+
+        *mem = TAKE_PTR(r);
+        *_len = len;
+
+        return 0;
+}
+
+/* https://tools.ietf.org/html/rfc4648#section-4 */
+char base64char(int x) {
+        static const char table[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                                      "abcdefghijklmnopqrstuvwxyz"
+                                      "0123456789+/";
+        return table[x & 63];
+}
+
+int unbase64char(char c) {
+        unsigned offset;
+
+        if (c >= 'A' && c <= 'Z')
+                return c - 'A';
+
+        offset = 'Z' - 'A' + 1;
+
+        if (c >= 'a' && c <= 'z')
+                return c - 'a' + offset;
+
+        offset += 'z' - 'a' + 1;
+
+        if (c >= '0' && c <= '9')
+                return c - '0' + offset;
+
+        offset += '9' - '0' + 1;
+
+        if (c == '+')
+                return offset;
+
+        offset++;
+
+        if (c == '/')
+                return offset;
+
+        return -EINVAL;
+}
+
+ssize_t base64mem(const void *p, size_t l, char **out) {
+        char *r, *z;
+        const uint8_t *x;
+
+        assert(p || l == 0);
+        assert(out);
+
+        /* three input bytes makes four output bytes, padding is added so we must round up */
+        z = r = malloc(4 * (l + 2) / 3 + 1);
+        if (!r)
+                return -ENOMEM;
+
+        for (x = p; x < (const uint8_t*) p + (l / 3) * 3; x += 3) {
+                /* x[0] == XXXXXXXX; x[1] == YYYYYYYY; x[2] == ZZZZZZZZ */
+                *(z++) = base64char(x[0] >> 2);                    /* 00XXXXXX */
+                *(z++) = base64char((x[0] & 3) << 4 | x[1] >> 4);  /* 00XXYYYY */
+                *(z++) = base64char((x[1] & 15) << 2 | x[2] >> 6); /* 00YYYYZZ */
+                *(z++) = base64char(x[2] & 63);                    /* 00ZZZZZZ */
+        }
+
+        switch (l % 3) {
+        case 2:
+                *(z++) = base64char(x[0] >> 2);                   /* 00XXXXXX */
+                *(z++) = base64char((x[0] & 3) << 4 | x[1] >> 4); /* 00XXYYYY */
+                *(z++) = base64char((x[1] & 15) << 2);            /* 00YYYY00 */
+                *(z++) = '=';
+
+                break;
+        case 1:
+                *(z++) = base64char(x[0] >> 2);        /* 00XXXXXX */
+                *(z++) = base64char((x[0] & 3) << 4);  /* 00XX0000 */
+                *(z++) = '=';
+                *(z++) = '=';
+
+                break;
+        }
+
+        *z = 0;
+        *out = r;
+        return z - r;
+}
+
+static int base64_append_width(
+                char **prefix, int plen,
+                const char *sep, int indent,
+                const void *p, size_t l,
+                int width) {
+
+        _cleanup_free_ char *x = NULL;
+        char *t, *s;
+        ssize_t len, slen, avail, line, lines;
+
+        len = base64mem(p, l, &x);
+        if (len <= 0)
+                return len;
+
+        lines = DIV_ROUND_UP(len, width);
+
+        slen = strlen_ptr(sep);
+        if (lines > (SSIZE_MAX - plen - 1 - slen) / (indent + width + 1))
+                return -ENOMEM;
+
+        t = realloc(*prefix, plen + 1 + slen + (indent + width + 1) * lines);
+        if (!t)
+                return -ENOMEM;
+
+        memcpy_safe(t + plen, sep, slen);
+
+        for (line = 0, s = t + plen + slen, avail = len; line < lines; line++) {
+                int act = MIN(width, avail);
+
+                if (line > 0 || sep) {
+                        memset(s, ' ', indent);
+                        s += indent;
+                }
+
+                memcpy(s, x + width * line, act);
+                s += act;
+                *(s++) = line < lines - 1 ? '\n' : '\0';
+                avail -= act;
+        }
+        assert(avail == 0);
+
+        *prefix = t;
+        return 0;
+}
+
+int base64_append(
+                char **prefix, int plen,
+                const void *p, size_t l,
+                int indent, int width) {
+
+        if (plen > width / 2 || plen + indent > width)
+                /* leave indent on the left, keep last column free */
+                return base64_append_width(prefix, plen, "\n", indent, p, l, width - indent - 1);
+        else
+                /* leave plen on the left, keep last column free */
+                return base64_append_width(prefix, plen, NULL, plen, p, l, width - plen - 1);
+}
+
+static int unbase64_next(const char **p, size_t *l) {
+        int ret;
+
+        assert(p);
+        assert(l);
+
+        /* Find the next non-whitespace character, and decode it. If we find padding, we return it as INT_MAX. We
+         * greedily skip all preceding and all following whitespace. */
+
+        for (;;) {
+                if (*l == 0)
+                        return -EPIPE;
+
+                if (!strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip leading whitespace */
+                (*p)++, (*l)--;
+        }
+
+        if (**p == '=')
+                ret = INT_MAX; /* return padding as INT_MAX */
+        else {
+                ret = unbase64char(**p);
+                if (ret < 0)
+                        return ret;
+        }
+
+        for (;;) {
+                (*p)++, (*l)--;
+
+                if (*l == 0)
+                        break;
+                if (!strchr(WHITESPACE, **p))
+                        break;
+
+                /* Skip following whitespace */
+        }
+
+        return ret;
+}
+
+int unbase64mem(const char *p, size_t l, void **ret, size_t *ret_size) {
+        _cleanup_free_ uint8_t *buf = NULL;
+        const char *x;
+        uint8_t *z;
+        size_t len;
+
+        assert(p || l == 0);
+        assert(ret);
+        assert(ret_size);
+
+        if (l == (size_t) -1)
+                l = strlen(p);
+
+        /* A group of four input bytes needs three output bytes, in case of padding we need to add two or three extra
+         * bytes. Note that this calculation is an upper boundary, as we ignore whitespace while decoding */
+        len = (l / 4) * 3 + (l % 4 != 0 ? (l % 4) - 1 : 0);
+
+        buf = malloc(len + 1);
+        if (!buf)
+                return -ENOMEM;
+
+        for (x = p, z = buf;;) {
+                int a, b, c, d; /* a == 00XXXXXX; b == 00YYYYYY; c == 00ZZZZZZ; d == 00WWWWWW */
+
+                a = unbase64_next(&x, &l);
+                if (a == -EPIPE) /* End of string */
+                        break;
+                if (a < 0)
+                        return a;
+                if (a == INT_MAX) /* Padding is not allowed at the beginning of a 4ch block */
+                        return -EINVAL;
+
+                b = unbase64_next(&x, &l);
+                if (b < 0)
+                        return b;
+                if (b == INT_MAX) /* Padding is not allowed at the second character of a 4ch block either */
+                        return -EINVAL;
+
+                c = unbase64_next(&x, &l);
+                if (c < 0)
+                        return c;
+
+                d = unbase64_next(&x, &l);
+                if (d < 0)
+                        return d;
+
+                if (c == INT_MAX) { /* Padding at the third character */
+
+                        if (d != INT_MAX) /* If the third character is padding, the fourth must be too */
+                                return -EINVAL;
+
+                        /* b == 00YY0000 */
+                        if (b & 15)
+                                return -EINVAL;
+
+                        if (l > 0) /* Trailing rubbish? */
+                                return -ENAMETOOLONG;
+
+                        *(z++) = (uint8_t) a << 2 | (uint8_t) (b >> 4); /* XXXXXXYY */
+                        break;
+                }
+
+                if (d == INT_MAX) {
+                        /* c == 00ZZZZ00 */
+                        if (c & 3)
+                                return -EINVAL;
+
+                        if (l > 0) /* Trailing rubbish? */
+                                return -ENAMETOOLONG;
+
+                        *(z++) = (uint8_t) a << 2 | (uint8_t) b >> 4; /* XXXXXXYY */
+                        *(z++) = (uint8_t) b << 4 | (uint8_t) c >> 2; /* YYYYZZZZ */
+                        break;
+                }
+
+                *(z++) = (uint8_t) a << 2 | (uint8_t) b >> 4; /* XXXXXXYY */
+                *(z++) = (uint8_t) b << 4 | (uint8_t) c >> 2; /* YYYYZZZZ */
+                *(z++) = (uint8_t) c << 6 | (uint8_t) d;      /* ZZWWWWWW */
+        }
+
+        *z = 0;
+
+        *ret_size = (size_t) (z - buf);
+        *ret = TAKE_PTR(buf);
+
+        return 0;
+}
+
+void hexdump(FILE *f, const void *p, size_t s) {
+        const uint8_t *b = p;
+        unsigned n = 0;
+
+        assert(b || s == 0);
+
+        if (!f)
+                f = stdout;
+
+        while (s > 0) {
+                size_t i;
+
+                fprintf(f, "%04x  ", n);
+
+                for (i = 0; i < 16; i++) {
+
+                        if (i >= s)
+                                fputs("   ", f);
+                        else
+                                fprintf(f, "%02x ", b[i]);
+
+                        if (i == 7)
+                                fputc(' ', f);
+                }
+
+                fputc(' ', f);
+
+                for (i = 0; i < 16; i++) {
+
+                        if (i >= s)
+                                fputc(' ', f);
+                        else
+                                fputc(isprint(b[i]) ? (char) b[i] : '.', f);
+                }
+
+                fputc('\n', f);
+
+                if (s < 16)
+                        break;
+
+                n += 16;
+                b += 16;
+                s -= 16;
+        }
+}
diff --git a/src/basic/hexdecoct.h b/src/basic/hexdecoct.h
new file mode 100644
index 0000000..9477d16
--- /dev/null
+++ b/src/basic/hexdecoct.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "macro.h"
+
+char octchar(int x) _const_;
+int unoctchar(char c) _const_;
+
+char decchar(int x) _const_;
+int undecchar(char c) _const_;
+
+char hexchar(int x) _const_;
+int unhexchar(char c) _const_;
+
+char *hexmem(const void *p, size_t l);
+int unhexmem(const char *p, size_t l, void **mem, size_t *len);
+
+char base32hexchar(int x) _const_;
+int unbase32hexchar(char c) _const_;
+
+char base64char(int x) _const_;
+int unbase64char(char c) _const_;
+
+char *base32hexmem(const void *p, size_t l, bool padding);
+int unbase32hexmem(const char *p, size_t l, bool padding, void **mem, size_t *len);
+
+ssize_t base64mem(const void *p, size_t l, char **out);
+int base64_append(char **prefix, int plen,
+                  const void *p, size_t l,
+                  int margin, int width);
+int unbase64mem(const char *p, size_t l, void **mem, size_t *len);
+
+void hexdump(FILE *f, const void *p, size_t s);
diff --git a/src/basic/hostname-util.c b/src/basic/hostname-util.c
new file mode 100644
index 0000000..5bfa028
--- /dev/null
+++ b/src/basic/hostname-util.c
@@ -0,0 +1,308 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/utsname.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "hostname-util.h"
+#include "macro.h"
+#include "string-util.h"
+
+bool hostname_is_set(void) {
+        struct utsname u;
+
+        assert_se(uname(&u) >= 0);
+
+        if (isempty(u.nodename))
+                return false;
+
+        /* This is the built-in kernel default host name */
+        if (streq(u.nodename, "(none)"))
+                return false;
+
+        return true;
+}
+
+char* gethostname_malloc(void) {
+        struct utsname u;
+
+        /* This call tries to return something useful, either the actual hostname
+         * or it makes something up. The only reason it might fail is OOM.
+         * It might even return "localhost" if that's set. */
+
+        assert_se(uname(&u) >= 0);
+
+        if (isempty(u.nodename) || streq(u.nodename, "(none)"))
+                return strdup(FALLBACK_HOSTNAME);
+
+        return strdup(u.nodename);
+}
+
+int gethostname_strict(char **ret) {
+        struct utsname u;
+        char *k;
+
+        /* This call will rather fail than make up a name. It will not return "localhost" either. */
+
+        assert_se(uname(&u) >= 0);
+
+        if (isempty(u.nodename))
+                return -ENXIO;
+
+        if (streq(u.nodename, "(none)"))
+                return -ENXIO;
+
+        if (is_localhost(u.nodename))
+                return -ENXIO;
+
+        k = strdup(u.nodename);
+        if (!k)
+                return -ENOMEM;
+
+        *ret = k;
+        return 0;
+}
+
+bool valid_ldh_char(char c) {
+        return
+                (c >= 'a' && c <= 'z') ||
+                (c >= 'A' && c <= 'Z') ||
+                (c >= '0' && c <= '9') ||
+                c == '-';
+}
+
+/**
+ * Check if s looks like a valid host name or FQDN. This does not do
+ * full DNS validation, but only checks if the name is composed of
+ * allowed characters and the length is not above the maximum allowed
+ * by Linux (c.f. dns_name_is_valid()). Trailing dot is allowed if
+ * allow_trailing_dot is true and at least two components are present
+ * in the name. Note that due to the restricted charset and length
+ * this call is substantially more conservative than
+ * dns_name_is_valid().
+ */
+bool hostname_is_valid(const char *s, bool allow_trailing_dot) {
+        unsigned n_dots = 0;
+        const char *p;
+        bool dot, hyphen;
+
+        if (isempty(s))
+                return false;
+
+        /* Doesn't accept empty hostnames, hostnames with
+         * leading dots, and hostnames with multiple dots in a
+         * sequence. Also ensures that the length stays below
+         * HOST_NAME_MAX. */
+
+        for (p = s, dot = hyphen = true; *p; p++)
+                if (*p == '.') {
+                        if (dot || hyphen)
+                                return false;
+
+                        dot = true;
+                        hyphen = false;
+                        n_dots++;
+
+                } else if (*p == '-') {
+                        if (dot)
+                                return false;
+
+                        dot = false;
+                        hyphen = true;
+
+                } else {
+                        if (!valid_ldh_char(*p))
+                                return false;
+
+                        dot = false;
+                        hyphen = false;
+                }
+
+        if (dot && (n_dots < 2 || !allow_trailing_dot))
+                return false;
+        if (hyphen)
+                return false;
+
+        if (p-s > HOST_NAME_MAX) /* Note that HOST_NAME_MAX is 64 on
+                                  * Linux, but DNS allows domain names
+                                  * up to 255 characters */
+                return false;
+
+        return true;
+}
+
+char* hostname_cleanup(char *s) {
+        char *p, *d;
+        bool dot, hyphen;
+
+        assert(s);
+
+        for (p = s, d = s, dot = hyphen = true; *p && d - s < HOST_NAME_MAX; p++)
+                if (*p == '.') {
+                        if (dot || hyphen)
+                                continue;
+
+                        *(d++) = '.';
+                        dot = true;
+                        hyphen = false;
+
+                } else if (*p == '-') {
+                        if (dot)
+                                continue;
+
+                        *(d++) = '-';
+                        dot = false;
+                        hyphen = true;
+
+                } else if (valid_ldh_char(*p)) {
+                        *(d++) = *p;
+                        dot = false;
+                        hyphen = false;
+                }
+
+        if (d > s && IN_SET(d[-1], '-', '.'))
+                /* The dot can occur at most once, but we might have multiple
+                 * hyphens, hence the loop */
+                d--;
+        *d = 0;
+
+        return s;
+}
+
+bool is_localhost(const char *hostname) {
+        assert(hostname);
+
+        /* This tries to identify local host and domain names
+         * described in RFC6761 plus the redhatism of localdomain */
+
+        return strcaseeq(hostname, "localhost") ||
+               strcaseeq(hostname, "localhost.") ||
+               strcaseeq(hostname, "localhost.localdomain") ||
+               strcaseeq(hostname, "localhost.localdomain.") ||
+               endswith_no_case(hostname, ".localhost") ||
+               endswith_no_case(hostname, ".localhost.") ||
+               endswith_no_case(hostname, ".localhost.localdomain") ||
+               endswith_no_case(hostname, ".localhost.localdomain.");
+}
+
+bool is_gateway_hostname(const char *hostname) {
+        assert(hostname);
+
+        /* This tries to identify the valid syntaxes for the our
+         * synthetic "gateway" host. */
+
+        return
+                strcaseeq(hostname, "_gateway") || strcaseeq(hostname, "_gateway.")
+#if ENABLE_COMPAT_GATEWAY_HOSTNAME
+                || strcaseeq(hostname, "gateway") || strcaseeq(hostname, "gateway.")
+#endif
+                ;
+}
+
+int sethostname_idempotent(const char *s) {
+        char buf[HOST_NAME_MAX + 1] = {};
+
+        assert(s);
+
+        if (gethostname(buf, sizeof(buf)) < 0)
+                return -errno;
+
+        if (streq(buf, s))
+                return 0;
+
+        if (sethostname(s, strlen(s)) < 0)
+                return -errno;
+
+        return 1;
+}
+
+int shorten_overlong(const char *s, char **ret) {
+        char *h, *p;
+
+        /* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
+         * whatever comes earlier. */
+
+        assert(s);
+
+        h = strdup(s);
+        if (!h)
+                return -ENOMEM;
+
+        if (hostname_is_valid(h, false)) {
+                *ret = h;
+                return 0;
+        }
+
+        p = strchr(h, '.');
+        if (p)
+                *p = 0;
+
+        strshorten(h, HOST_NAME_MAX);
+
+        if (!hostname_is_valid(h, false)) {
+                free(h);
+                return -EDOM;
+        }
+
+        *ret = h;
+        return 1;
+}
+
+int read_etc_hostname_stream(FILE *f, char **ret) {
+        int r;
+
+        assert(f);
+        assert(ret);
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                char *p;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0) /* EOF without any hostname? the file is empty, let's treat that exactly like no file at all: ENOENT */
+                        return -ENOENT;
+
+                p = strstrip(line);
+
+                /* File may have empty lines or comments, ignore them */
+                if (!IN_SET(*p, '\0', '#')) {
+                        char *copy;
+
+                        hostname_cleanup(p); /* normalize the hostname */
+
+                        if (!hostname_is_valid(p, true)) /* check that the hostname we return is valid */
+                                return -EBADMSG;
+
+                        copy = strdup(p);
+                        if (!copy)
+                                return -ENOMEM;
+
+                        *ret = copy;
+                        return 0;
+                }
+        }
+}
+
+int read_etc_hostname(const char *path, char **ret) {
+        _cleanup_fclose_ FILE *f = NULL;
+
+        assert(ret);
+
+        if (!path)
+                path = "/etc/hostname";
+
+        f = fopen(path, "re");
+        if (!f)
+                return -errno;
+
+        return read_etc_hostname_stream(f, ret);
+
+}
diff --git a/src/basic/hostname-util.h b/src/basic/hostname-util.h
new file mode 100644
index 0000000..7ba386a
--- /dev/null
+++ b/src/basic/hostname-util.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stdio.h>
+
+#include "macro.h"
+
+bool hostname_is_set(void);
+
+char* gethostname_malloc(void);
+int gethostname_strict(char **ret);
+
+bool valid_ldh_char(char c) _const_;
+bool hostname_is_valid(const char *s, bool allow_trailing_dot) _pure_;
+char* hostname_cleanup(char *s);
+
+#define machine_name_is_valid(s) hostname_is_valid(s, false)
+
+bool is_localhost(const char *hostname);
+bool is_gateway_hostname(const char *hostname);
+
+int sethostname_idempotent(const char *s);
+
+int shorten_overlong(const char *s, char **ret);
+
+int read_etc_hostname_stream(FILE *f, char **ret);
+int read_etc_hostname(const char *path, char **ret);
diff --git a/src/basic/in-addr-util.c b/src/basic/in-addr-util.c
new file mode 100644
index 0000000..2bffe47
--- /dev/null
+++ b/src/basic/in-addr-util.c
@@ -0,0 +1,622 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <arpa/inet.h>
+#include <endian.h>
+#include <errno.h>
+#include <net/if.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "in-addr-util.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "util.h"
+
+bool in4_addr_is_null(const struct in_addr *a) {
+        assert(a);
+
+        return a->s_addr == 0;
+}
+
+int in_addr_is_null(int family, const union in_addr_union *u) {
+        assert(u);
+
+        if (family == AF_INET)
+                return in4_addr_is_null(&u->in);
+
+        if (family == AF_INET6)
+                return IN6_IS_ADDR_UNSPECIFIED(&u->in6);
+
+        return -EAFNOSUPPORT;
+}
+
+bool in4_addr_is_link_local(const struct in_addr *a) {
+        assert(a);
+
+        return (be32toh(a->s_addr) & UINT32_C(0xFFFF0000)) == (UINT32_C(169) << 24 | UINT32_C(254) << 16);
+}
+
+int in_addr_is_link_local(int family, const union in_addr_union *u) {
+        assert(u);
+
+        if (family == AF_INET)
+                return in4_addr_is_link_local(&u->in);
+
+        if (family == AF_INET6)
+                return IN6_IS_ADDR_LINKLOCAL(&u->in6);
+
+        return -EAFNOSUPPORT;
+}
+
+int in_addr_is_multicast(int family, const union in_addr_union *u) {
+        assert(u);
+
+        if (family == AF_INET)
+                return IN_MULTICAST(be32toh(u->in.s_addr));
+
+        if (family == AF_INET6)
+                return IN6_IS_ADDR_MULTICAST(&u->in6);
+
+        return -EAFNOSUPPORT;
+}
+
+bool in4_addr_is_localhost(const struct in_addr *a) {
+        assert(a);
+
+        /* All of 127.x.x.x is localhost. */
+        return (be32toh(a->s_addr) & UINT32_C(0xFF000000)) == UINT32_C(127) << 24;
+}
+
+int in_addr_is_localhost(int family, const union in_addr_union *u) {
+        assert(u);
+
+        if (family == AF_INET)
+                return in4_addr_is_localhost(&u->in);
+
+        if (family == AF_INET6)
+                return IN6_IS_ADDR_LOOPBACK(&u->in6);
+
+        return -EAFNOSUPPORT;
+}
+
+int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b) {
+        assert(a);
+        assert(b);
+
+        if (family == AF_INET)
+                return a->in.s_addr == b->in.s_addr;
+
+        if (family == AF_INET6)
+                return
+                        a->in6.s6_addr32[0] == b->in6.s6_addr32[0] &&
+                        a->in6.s6_addr32[1] == b->in6.s6_addr32[1] &&
+                        a->in6.s6_addr32[2] == b->in6.s6_addr32[2] &&
+                        a->in6.s6_addr32[3] == b->in6.s6_addr32[3];
+
+        return -EAFNOSUPPORT;
+}
+
+int in_addr_prefix_intersect(
+                int family,
+                const union in_addr_union *a,
+                unsigned aprefixlen,
+                const union in_addr_union *b,
+                unsigned bprefixlen) {
+
+        unsigned m;
+
+        assert(a);
+        assert(b);
+
+        /* Checks whether there are any addresses that are in both
+         * networks */
+
+        m = MIN(aprefixlen, bprefixlen);
+
+        if (family == AF_INET) {
+                uint32_t x, nm;
+
+                x = be32toh(a->in.s_addr ^ b->in.s_addr);
+                nm = (m == 0) ? 0 : 0xFFFFFFFFUL << (32 - m);
+
+                return (x & nm) == 0;
+        }
+
+        if (family == AF_INET6) {
+                unsigned i;
+
+                if (m > 128)
+                        m = 128;
+
+                for (i = 0; i < 16; i++) {
+                        uint8_t x, nm;
+
+                        x = a->in6.s6_addr[i] ^ b->in6.s6_addr[i];
+
+                        if (m < 8)
+                                nm = 0xFF << (8 - m);
+                        else
+                                nm = 0xFF;
+
+                        if ((x & nm) != 0)
+                                return 0;
+
+                        if (m > 8)
+                                m -= 8;
+                        else
+                                m = 0;
+                }
+
+                return 1;
+        }
+
+        return -EAFNOSUPPORT;
+}
+
+int in_addr_prefix_next(int family, union in_addr_union *u, unsigned prefixlen) {
+        assert(u);
+
+        /* Increases the network part of an address by one. Returns
+         * positive it that succeeds, or 0 if this overflows. */
+
+        if (prefixlen <= 0)
+                return 0;
+
+        if (family == AF_INET) {
+                uint32_t c, n;
+
+                if (prefixlen > 32)
+                        prefixlen = 32;
+
+                c = be32toh(u->in.s_addr);
+                n = c + (1UL << (32 - prefixlen));
+                if (n < c)
+                        return 0;
+                n &= 0xFFFFFFFFUL << (32 - prefixlen);
+
+                u->in.s_addr = htobe32(n);
+                return 1;
+        }
+
+        if (family == AF_INET6) {
+                struct in6_addr add = {}, result;
+                uint8_t overflow = 0;
+                unsigned i;
+
+                if (prefixlen > 128)
+                        prefixlen = 128;
+
+                /* First calculate what we have to add */
+                add.s6_addr[(prefixlen-1) / 8] = 1 << (7 - (prefixlen-1) % 8);
+
+                for (i = 16; i > 0; i--) {
+                        unsigned j = i - 1;
+
+                        result.s6_addr[j] = u->in6.s6_addr[j] + add.s6_addr[j] + overflow;
+                        overflow = (result.s6_addr[j] < u->in6.s6_addr[j]);
+                }
+
+                if (overflow)
+                        return 0;
+
+                u->in6 = result;
+                return 1;
+        }
+
+        return -EAFNOSUPPORT;
+}
+
+int in_addr_to_string(int family, const union in_addr_union *u, char **ret) {
+        char *x;
+        size_t l;
+
+        assert(u);
+        assert(ret);
+
+        if (family == AF_INET)
+                l = INET_ADDRSTRLEN;
+        else if (family == AF_INET6)
+                l = INET6_ADDRSTRLEN;
+        else
+                return -EAFNOSUPPORT;
+
+        x = new(char, l);
+        if (!x)
+                return -ENOMEM;
+
+        errno = 0;
+        if (!inet_ntop(family, u, x, l)) {
+                free(x);
+                return errno > 0 ? -errno : -EINVAL;
+        }
+
+        *ret = x;
+        return 0;
+}
+
+int in_addr_ifindex_to_string(int family, const union in_addr_union *u, int ifindex, char **ret) {
+        size_t l;
+        char *x;
+        int r;
+
+        assert(u);
+        assert(ret);
+
+        /* Much like in_addr_to_string(), but optionally appends the zone interface index to the address, to properly
+         * handle IPv6 link-local addresses. */
+
+        if (family != AF_INET6)
+                goto fallback;
+        if (ifindex <= 0)
+                goto fallback;
+
+        r = in_addr_is_link_local(family, u);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                goto fallback;
+
+        l = INET6_ADDRSTRLEN + 1 + DECIMAL_STR_MAX(ifindex) + 1;
+        x = new(char, l);
+        if (!x)
+                return -ENOMEM;
+
+        errno = 0;
+        if (!inet_ntop(family, u, x, l)) {
+                free(x);
+                return errno > 0 ? -errno : -EINVAL;
+        }
+
+        sprintf(strchr(x, 0), "%%%i", ifindex);
+        *ret = x;
+
+        return 0;
+
+fallback:
+        return in_addr_to_string(family, u, ret);
+}
+
+int in_addr_from_string(int family, const char *s, union in_addr_union *ret) {
+        union in_addr_union buffer;
+        assert(s);
+
+        if (!IN_SET(family, AF_INET, AF_INET6))
+                return -EAFNOSUPPORT;
+
+        errno = 0;
+        if (inet_pton(family, s, ret ?: &buffer) <= 0)
+                return errno > 0 ? -errno : -EINVAL;
+
+        return 0;
+}
+
+int in_addr_from_string_auto(const char *s, int *ret_family, union in_addr_union *ret) {
+        int r;
+
+        assert(s);
+
+        r = in_addr_from_string(AF_INET, s, ret);
+        if (r >= 0) {
+                if (ret_family)
+                        *ret_family = AF_INET;
+                return 0;
+        }
+
+        r = in_addr_from_string(AF_INET6, s, ret);
+        if (r >= 0) {
+                if (ret_family)
+                        *ret_family = AF_INET6;
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+int in_addr_ifindex_from_string_auto(const char *s, int *family, union in_addr_union *ret, int *ifindex) {
+        _cleanup_free_ char *buf = NULL;
+        const char *suffix;
+        int r, ifi = 0;
+
+        assert(s);
+        assert(family);
+        assert(ret);
+
+        /* Similar to in_addr_from_string_auto() but also parses an optionally appended IPv6 zone suffix ("scope id")
+         * if one is found. */
+
+        suffix = strchr(s, '%');
+        if (suffix) {
+
+                if (ifindex) {
+                        /* If we shall return the interface index, try to parse it */
+                        r = parse_ifindex(suffix + 1, &ifi);
+                        if (r < 0) {
+                                unsigned u;
+
+                                u = if_nametoindex(suffix + 1);
+                                if (u <= 0)
+                                        return -errno;
+
+                                ifi = (int) u;
+                        }
+                }
+
+                buf = strndup(s, suffix - s);
+                if (!buf)
+                        return -ENOMEM;
+
+                s = buf;
+        }
+
+        r = in_addr_from_string_auto(s, family, ret);
+        if (r < 0)
+                return r;
+
+        if (ifindex)
+                *ifindex = ifi;
+
+        return r;
+}
+
+unsigned char in4_addr_netmask_to_prefixlen(const struct in_addr *addr) {
+        assert(addr);
+
+        return 32U - u32ctz(be32toh(addr->s_addr));
+}
+
+struct in_addr* in4_addr_prefixlen_to_netmask(struct in_addr *addr, unsigned char prefixlen) {
+        assert(addr);
+        assert(prefixlen <= 32);
+
+        /* Shifting beyond 32 is not defined, handle this specially. */
+        if (prefixlen == 0)
+                addr->s_addr = 0;
+        else
+                addr->s_addr = htobe32((0xffffffff << (32 - prefixlen)) & 0xffffffff);
+
+        return addr;
+}
+
+int in4_addr_default_prefixlen(const struct in_addr *addr, unsigned char *prefixlen) {
+        uint8_t msb_octet = *(uint8_t*) addr;
+
+        /* addr may not be aligned, so make sure we only access it byte-wise */
+
+        assert(addr);
+        assert(prefixlen);
+
+        if (msb_octet < 128)
+                /* class A, leading bits: 0 */
+                *prefixlen = 8;
+        else if (msb_octet < 192)
+                /* class B, leading bits 10 */
+                *prefixlen = 16;
+        else if (msb_octet < 224)
+                /* class C, leading bits 110 */
+                *prefixlen = 24;
+        else
+                /* class D or E, no default prefixlen */
+                return -ERANGE;
+
+        return 0;
+}
+
+int in4_addr_default_subnet_mask(const struct in_addr *addr, struct in_addr *mask) {
+        unsigned char prefixlen;
+        int r;
+
+        assert(addr);
+        assert(mask);
+
+        r = in4_addr_default_prefixlen(addr, &prefixlen);
+        if (r < 0)
+                return r;
+
+        in4_addr_prefixlen_to_netmask(mask, prefixlen);
+        return 0;
+}
+
+int in_addr_mask(int family, union in_addr_union *addr, unsigned char prefixlen) {
+        assert(addr);
+
+        if (family == AF_INET) {
+                struct in_addr mask;
+
+                if (!in4_addr_prefixlen_to_netmask(&mask, prefixlen))
+                        return -EINVAL;
+
+                addr->in.s_addr &= mask.s_addr;
+                return 0;
+        }
+
+        if (family == AF_INET6) {
+                unsigned i;
+
+                for (i = 0; i < 16; i++) {
+                        uint8_t mask;
+
+                        if (prefixlen >= 8) {
+                                mask = 0xFF;
+                                prefixlen -= 8;
+                        } else {
+                                mask = 0xFF << (8 - prefixlen);
+                                prefixlen = 0;
+                        }
+
+                        addr->in6.s6_addr[i] &= mask;
+                }
+
+                return 0;
+        }
+
+        return -EAFNOSUPPORT;
+}
+
+int in_addr_prefix_covers(int family,
+                          const union in_addr_union *prefix,
+                          unsigned char prefixlen,
+                          const union in_addr_union *address) {
+
+        union in_addr_union masked_prefix, masked_address;
+        int r;
+
+        assert(prefix);
+        assert(address);
+
+        masked_prefix = *prefix;
+        r = in_addr_mask(family, &masked_prefix, prefixlen);
+        if (r < 0)
+                return r;
+
+        masked_address = *address;
+        r = in_addr_mask(family, &masked_address, prefixlen);
+        if (r < 0)
+                return r;
+
+        return in_addr_equal(family, &masked_prefix, &masked_address);
+}
+
+int in_addr_parse_prefixlen(int family, const char *p, unsigned char *ret) {
+        uint8_t u;
+        int r;
+
+        if (!IN_SET(family, AF_INET, AF_INET6))
+                return -EAFNOSUPPORT;
+
+        r = safe_atou8(p, &u);
+        if (r < 0)
+                return r;
+
+        if (u > FAMILY_ADDRESS_SIZE(family) * 8)
+                return -ERANGE;
+
+        *ret = u;
+        return 0;
+}
+
+int in_addr_prefix_from_string(
+                const char *p,
+                int family,
+                union in_addr_union *ret_prefix,
+                unsigned char *ret_prefixlen) {
+
+        _cleanup_free_ char *str = NULL;
+        union in_addr_union buffer;
+        const char *e, *l;
+        unsigned char k;
+        int r;
+
+        assert(p);
+
+        if (!IN_SET(family, AF_INET, AF_INET6))
+                return -EAFNOSUPPORT;
+
+        e = strchr(p, '/');
+        if (e) {
+                str = strndup(p, e - p);
+                if (!str)
+                        return -ENOMEM;
+
+                l = str;
+        } else
+                l = p;
+
+        r = in_addr_from_string(family, l, &buffer);
+        if (r < 0)
+                return r;
+
+        if (e) {
+                r = in_addr_parse_prefixlen(family, e+1, &k);
+                if (r < 0)
+                        return r;
+        } else
+                k = FAMILY_ADDRESS_SIZE(family) * 8;
+
+        if (ret_prefix)
+                *ret_prefix = buffer;
+        if (ret_prefixlen)
+                *ret_prefixlen = k;
+
+        return 0;
+}
+
+int in_addr_prefix_from_string_auto_internal(
+                const char *p,
+                InAddrPrefixLenMode mode,
+                int *ret_family,
+                union in_addr_union *ret_prefix,
+                unsigned char *ret_prefixlen) {
+
+        _cleanup_free_ char *str = NULL;
+        union in_addr_union buffer;
+        const char *e, *l;
+        unsigned char k;
+        int family, r;
+
+        assert(p);
+
+        e = strchr(p, '/');
+        if (e) {
+                str = strndup(p, e - p);
+                if (!str)
+                        return -ENOMEM;
+
+                l = str;
+        } else
+                l = p;
+
+        r = in_addr_from_string_auto(l, &family, &buffer);
+        if (r < 0)
+                return r;
+
+        if (e) {
+                r = in_addr_parse_prefixlen(family, e+1, &k);
+                if (r < 0)
+                        return r;
+        } else
+                switch (mode) {
+                case PREFIXLEN_FULL:
+                        k = FAMILY_ADDRESS_SIZE(family) * 8;
+                        break;
+                case PREFIXLEN_REFUSE:
+                        return -ENOANO; /* To distinguish this error from others. */
+                case PREFIXLEN_LEGACY:
+                        if (family == AF_INET) {
+                                r = in4_addr_default_prefixlen(&buffer.in, &k);
+                                if (r < 0)
+                                        return r;
+                        } else
+                                k = 0;
+                        break;
+                default:
+                        assert_not_reached("Invalid prefixlen mode");
+                }
+
+        if (ret_family)
+                *ret_family = family;
+        if (ret_prefix)
+                *ret_prefix = buffer;
+        if (ret_prefixlen)
+                *ret_prefixlen = k;
+
+        return 0;
+
+}
+
+static void in_addr_data_hash_func(const struct in_addr_data *a, struct siphash *state) {
+        siphash24_compress(&a->family, sizeof(a->family), state);
+        siphash24_compress(&a->address, FAMILY_ADDRESS_SIZE(a->family), state);
+}
+
+static int in_addr_data_compare_func(const struct in_addr_data *x, const struct in_addr_data *y) {
+        int r;
+
+        r = CMP(x->family, y->family);
+        if (r != 0)
+                return r;
+
+        return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
+}
+
+DEFINE_HASH_OPS(in_addr_data_hash_ops, struct in_addr_data, in_addr_data_hash_func, in_addr_data_compare_func);
diff --git a/src/basic/in-addr-util.h b/src/basic/in-addr-util.h
new file mode 100644
index 0000000..3069790
--- /dev/null
+++ b/src/basic/in-addr-util.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <netinet/in.h>
+#include <stddef.h>
+#include <sys/socket.h>
+
+#include "hash-funcs.h"
+#include "macro.h"
+#include "util.h"
+
+union in_addr_union {
+        struct in_addr in;
+        struct in6_addr in6;
+};
+
+struct in_addr_data {
+        int family;
+        union in_addr_union address;
+};
+
+bool in4_addr_is_null(const struct in_addr *a);
+int in_addr_is_null(int family, const union in_addr_union *u);
+
+int in_addr_is_multicast(int family, const union in_addr_union *u);
+
+bool in4_addr_is_link_local(const struct in_addr *a);
+int in_addr_is_link_local(int family, const union in_addr_union *u);
+
+bool in4_addr_is_localhost(const struct in_addr *a);
+int in_addr_is_localhost(int family, const union in_addr_union *u);
+
+int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b);
+int in_addr_prefix_intersect(int family, const union in_addr_union *a, unsigned aprefixlen, const union in_addr_union *b, unsigned bprefixlen);
+int in_addr_prefix_next(int family, union in_addr_union *u, unsigned prefixlen);
+int in_addr_to_string(int family, const union in_addr_union *u, char **ret);
+int in_addr_ifindex_to_string(int family, const union in_addr_union *u, int ifindex, char **ret);
+int in_addr_from_string(int family, const char *s, union in_addr_union *ret);
+int in_addr_from_string_auto(const char *s, int *ret_family, union in_addr_union *ret);
+int in_addr_ifindex_from_string_auto(const char *s, int *family, union in_addr_union *ret, int *ifindex);
+unsigned char in4_addr_netmask_to_prefixlen(const struct in_addr *addr);
+struct in_addr* in4_addr_prefixlen_to_netmask(struct in_addr *addr, unsigned char prefixlen);
+int in4_addr_default_prefixlen(const struct in_addr *addr, unsigned char *prefixlen);
+int in4_addr_default_subnet_mask(const struct in_addr *addr, struct in_addr *mask);
+int in_addr_mask(int family, union in_addr_union *addr, unsigned char prefixlen);
+int in_addr_prefix_covers(int family, const union in_addr_union *prefix, unsigned char prefixlen, const union in_addr_union *address);
+int in_addr_parse_prefixlen(int family, const char *p, unsigned char *ret);
+int in_addr_prefix_from_string(const char *p, int family, union in_addr_union *ret_prefix, unsigned char *ret_prefixlen);
+
+typedef enum InAddrPrefixLenMode {
+        PREFIXLEN_FULL,   /* Default to prefixlen of address size, 32 for IPv4 or 128 for IPv6, if not specified. */
+        PREFIXLEN_REFUSE, /* Fail with -ENOANO if prefixlen is not specified. */
+        PREFIXLEN_LEGACY, /* Default to legacy default prefixlen calculation from address if not specified. */
+} InAddrPrefixLenMode;
+
+int in_addr_prefix_from_string_auto_internal(const char *p, InAddrPrefixLenMode mode, int *ret_family, union in_addr_union *ret_prefix, unsigned char *ret_prefixlen);
+static inline int in_addr_prefix_from_string_auto(const char *p, int *ret_family, union in_addr_union *ret_prefix, unsigned char *ret_prefixlen) {
+        return in_addr_prefix_from_string_auto_internal(p, PREFIXLEN_FULL, ret_family, ret_prefix, ret_prefixlen);
+}
+
+static inline size_t FAMILY_ADDRESS_SIZE(int family) {
+        assert(IN_SET(family, AF_INET, AF_INET6));
+        return family == AF_INET6 ? 16 : 4;
+}
+
+/* Workaround for clang, explicitly specify the maximum-size element here.
+ * See also oss-fuzz#11344. */
+#define IN_ADDR_NULL ((union in_addr_union) { .in6 = {} })
+
+extern const struct hash_ops in_addr_data_hash_ops;
diff --git a/src/basic/io-util.c b/src/basic/io-util.c
new file mode 100644
index 0000000..575398f
--- /dev/null
+++ b/src/basic/io-util.c
@@ -0,0 +1,264 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <poll.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "io-util.h"
+#include "string-util.h"
+#include "time-util.h"
+
+int flush_fd(int fd) {
+        struct pollfd pollfd = {
+                .fd = fd,
+                .events = POLLIN,
+        };
+        int count = 0;
+
+        /* Read from the specified file descriptor, until POLLIN is not set anymore, throwing away everything
+         * read. Note that some file descriptors (notable IP sockets) will trigger POLLIN even when no data can be read
+         * (due to IP packet checksum mismatches), hence this function is only safe to be non-blocking if the fd used
+         * was set to non-blocking too. */
+
+        for (;;) {
+                char buf[LINE_MAX];
+                ssize_t l;
+                int r;
+
+                r = poll(&pollfd, 1, 0);
+                if (r < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        return -errno;
+
+                } else if (r == 0)
+                        return count;
+
+                l = read(fd, buf, sizeof(buf));
+                if (l < 0) {
+
+                        if (errno == EINTR)
+                                continue;
+
+                        if (errno == EAGAIN)
+                                return count;
+
+                        return -errno;
+                } else if (l == 0)
+                        return count;
+
+                count += (int) l;
+        }
+}
+
+ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
+        uint8_t *p = buf;
+        ssize_t n = 0;
+
+        assert(fd >= 0);
+        assert(buf);
+
+        /* If called with nbytes == 0, let's call read() at least
+         * once, to validate the operation */
+
+        if (nbytes > (size_t) SSIZE_MAX)
+                return -EINVAL;
+
+        do {
+                ssize_t k;
+
+                k = read(fd, p, nbytes);
+                if (k < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        if (errno == EAGAIN && do_poll) {
+
+                                /* We knowingly ignore any return value here,
+                                 * and expect that any error/EOF is reported
+                                 * via read() */
+
+                                (void) fd_wait_for_event(fd, POLLIN, USEC_INFINITY);
+                                continue;
+                        }
+
+                        return n > 0 ? n : -errno;
+                }
+
+                if (k == 0)
+                        return n;
+
+                assert((size_t) k <= nbytes);
+
+                p += k;
+                nbytes -= k;
+                n += k;
+        } while (nbytes > 0);
+
+        return n;
+}
+
+int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll) {
+        ssize_t n;
+
+        n = loop_read(fd, buf, nbytes, do_poll);
+        if (n < 0)
+                return (int) n;
+        if ((size_t) n != nbytes)
+                return -EIO;
+
+        return 0;
+}
+
+int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
+        const uint8_t *p = buf;
+
+        assert(fd >= 0);
+        assert(buf);
+
+        if (_unlikely_(nbytes > (size_t) SSIZE_MAX))
+                return -EINVAL;
+
+        do {
+                ssize_t k;
+
+                k = write(fd, p, nbytes);
+                if (k < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        if (errno == EAGAIN && do_poll) {
+                                /* We knowingly ignore any return value here,
+                                 * and expect that any error/EOF is reported
+                                 * via write() */
+
+                                (void) fd_wait_for_event(fd, POLLOUT, USEC_INFINITY);
+                                continue;
+                        }
+
+                        return -errno;
+                }
+
+                if (_unlikely_(nbytes > 0 && k == 0)) /* Can't really happen */
+                        return -EIO;
+
+                assert((size_t) k <= nbytes);
+
+                p += k;
+                nbytes -= k;
+        } while (nbytes > 0);
+
+        return 0;
+}
+
+int pipe_eof(int fd) {
+        struct pollfd pollfd = {
+                .fd = fd,
+                .events = POLLIN|POLLHUP,
+        };
+
+        int r;
+
+        r = poll(&pollfd, 1, 0);
+        if (r < 0)
+                return -errno;
+
+        if (r == 0)
+                return 0;
+
+        return pollfd.revents & POLLHUP;
+}
+
+int fd_wait_for_event(int fd, int event, usec_t t) {
+
+        struct pollfd pollfd = {
+                .fd = fd,
+                .events = event,
+        };
+
+        struct timespec ts;
+        int r;
+
+        r = ppoll(&pollfd, 1, t == USEC_INFINITY ? NULL : timespec_store(&ts, t), NULL);
+        if (r < 0)
+                return -errno;
+        if (r == 0)
+                return 0;
+
+        return pollfd.revents;
+}
+
+static size_t nul_length(const uint8_t *p, size_t sz) {
+        size_t n = 0;
+
+        while (sz > 0) {
+                if (*p != 0)
+                        break;
+
+                n++;
+                p++;
+                sz--;
+        }
+
+        return n;
+}
+
+ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length) {
+        const uint8_t *q, *w, *e;
+        ssize_t l;
+
+        q = w = p;
+        e = q + sz;
+        while (q < e) {
+                size_t n;
+
+                n = nul_length(q, e - q);
+
+                /* If there are more than the specified run length of
+                 * NUL bytes, or if this is the beginning or the end
+                 * of the buffer, then seek instead of write */
+                if ((n > run_length) ||
+                    (n > 0 && q == p) ||
+                    (n > 0 && q + n >= e)) {
+                        if (q > w) {
+                                l = write(fd, w, q - w);
+                                if (l < 0)
+                                        return -errno;
+                                if (l != q -w)
+                                        return -EIO;
+                        }
+
+                        if (lseek(fd, n, SEEK_CUR) == (off_t) -1)
+                                return -errno;
+
+                        q += n;
+                        w = q;
+                } else if (n > 0)
+                        q += n;
+                else
+                        q++;
+        }
+
+        if (q > w) {
+                l = write(fd, w, q - w);
+                if (l < 0)
+                        return -errno;
+                if (l != q - w)
+                        return -EIO;
+        }
+
+        return q - (const uint8_t*) p;
+}
+
+char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) {
+        char *x;
+
+        x = strappend(field, value);
+        if (x)
+                iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x);
+        return x;
+}
diff --git a/src/basic/io-util.h b/src/basic/io-util.h
new file mode 100644
index 0000000..792a64a
--- /dev/null
+++ b/src/basic/io-util.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+
+#include "macro.h"
+#include "time-util.h"
+
+int flush_fd(int fd);
+
+ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll);
+int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll);
+int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll);
+
+int pipe_eof(int fd);
+
+int fd_wait_for_event(int fd, int event, usec_t timeout);
+
+ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length);
+
+static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, size_t n) {
+        size_t j, r = 0;
+
+        for (j = 0; j < n; j++)
+                r += i[j].iov_len;
+
+        return r;
+}
+
+static inline size_t IOVEC_INCREMENT(struct iovec *i, size_t n, size_t k) {
+        size_t j;
+
+        for (j = 0; j < n; j++) {
+                size_t sub;
+
+                if (_unlikely_(k <= 0))
+                        break;
+
+                sub = MIN(i[j].iov_len, k);
+                i[j].iov_len -= sub;
+                i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
+                k -= sub;
+        }
+
+        return k;
+}
+
+static inline bool FILE_SIZE_VALID(uint64_t l) {
+        /* ftruncate() and friends take an unsigned file size, but actually cannot deal with file sizes larger than
+         * 2^63 since the kernel internally handles it as signed value. This call allows checking for this early. */
+
+        return (l >> 63) == 0;
+}
+
+static inline bool FILE_SIZE_VALID_OR_INFINITY(uint64_t l) {
+
+        /* Same as above, but allows one extra value: -1 as indication for infinity. */
+
+        if (l == (uint64_t) -1)
+                return true;
+
+        return FILE_SIZE_VALID(l);
+
+}
+
+#define IOVEC_INIT(base, len) { .iov_base = (base), .iov_len = (len) }
+#define IOVEC_MAKE(base, len) (struct iovec) IOVEC_INIT(base, len)
+#define IOVEC_INIT_STRING(string) IOVEC_INIT((char*) string, strlen(string))
+#define IOVEC_MAKE_STRING(string) (struct iovec) IOVEC_INIT_STRING(string)
+
+char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value);
diff --git a/src/basic/ioprio.h b/src/basic/ioprio.h
new file mode 100644
index 0000000..3fb168d
--- /dev/null
+++ b/src/basic/ioprio.h
@@ -0,0 +1,56 @@
+#ifndef IOPRIO_H
+#define IOPRIO_H
+
+/* This is minimal version of Linux' linux/ioprio.h header file, which
+ * is licensed GPL2 */
+
+#include <sys/syscall.h>
+#include <unistd.h>
+
+/*
+ * Gives us 8 prio classes with 13-bits of data for each class
+ */
+#define IOPRIO_BITS             16
+#define IOPRIO_N_CLASSES        8
+#define IOPRIO_CLASS_SHIFT      13
+#define IOPRIO_PRIO_MASK        ((1UL << IOPRIO_CLASS_SHIFT) - 1)
+
+#define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT)
+#define IOPRIO_PRIO_DATA(mask)  ((mask) & IOPRIO_PRIO_MASK)
+#define IOPRIO_PRIO_VALUE(class, data)  (((class) << IOPRIO_CLASS_SHIFT) | data)
+
+#define ioprio_valid(mask)      (IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE)
+
+/*
+ * These are the io priority groups as implemented by CFQ. RT is the realtime
+ * class, it always gets premium service. BE is the best-effort scheduling
+ * class, the default for any process. IDLE is the idle scheduling class, it
+ * is only served when no one else is using the disk.
+ */
+enum {
+        IOPRIO_CLASS_NONE,
+        IOPRIO_CLASS_RT,
+        IOPRIO_CLASS_BE,
+        IOPRIO_CLASS_IDLE,
+};
+
+/*
+ * 8 best effort priority levels are supported
+ */
+#define IOPRIO_BE_NR    (8)
+
+enum {
+        IOPRIO_WHO_PROCESS = 1,
+        IOPRIO_WHO_PGRP,
+        IOPRIO_WHO_USER,
+};
+
+static inline int ioprio_set(int which, int who, int ioprio) {
+        return syscall(__NR_ioprio_set, which, who, ioprio);
+}
+
+static inline int ioprio_get(int which, int who) {
+        return syscall(__NR_ioprio_get, which, who);
+}
+
+#endif
diff --git a/src/basic/khash.c b/src/basic/khash.c
new file mode 100644
index 0000000..847f257
--- /dev/null
+++ b/src/basic/khash.c
@@ -0,0 +1,322 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <linux/if_alg.h>
+#include <stdbool.h>
+#include <sys/socket.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "hexdecoct.h"
+#include "khash.h"
+#include "macro.h"
+#include "missing.h"
+#include "string-util.h"
+#include "util.h"
+
+/* On current kernels the maximum digest (according to "grep digestsize /proc/crypto | sort -u") is actually 32, but
+ * let's add some extra room, the few wasted bytes don't really matter... */
+#define LONGEST_DIGEST 128
+
+struct khash {
+        int fd;
+        char *algorithm;
+        uint8_t digest[LONGEST_DIGEST+1];
+        size_t digest_size;
+        bool digest_valid;
+};
+
+int khash_supported(void) {
+        static const union {
+                struct sockaddr sa;
+                struct sockaddr_alg alg;
+        } sa = {
+                .alg.salg_family = AF_ALG,
+                .alg.salg_type = "hash",
+                .alg.salg_name = "sha256", /* a very common algorithm */
+        };
+
+        static int cached = -1;
+
+        if (cached < 0) {
+                _cleanup_close_ int fd1 = -1, fd2 = -1;
+                uint8_t buf[LONGEST_DIGEST+1];
+
+                fd1 = socket(AF_ALG, SOCK_SEQPACKET|SOCK_CLOEXEC, 0);
+                if (fd1 < 0) {
+                        /* The kernel returns EAFNOSUPPORT if AF_ALG is not supported at all */
+                        if (IN_SET(errno, EAFNOSUPPORT, EOPNOTSUPP))
+                                return (cached = false);
+
+                        return -errno;
+                }
+
+                if (bind(fd1, &sa.sa, sizeof(sa)) < 0) {
+                        /* The kernel returns ENOENT if the selected algorithm is not supported at all. We use a check
+                         * for SHA256 as a proxy for whether the whole API is supported at all. After all it's one of
+                         * the most common hash functions, and if it isn't supported, that's ample indication that
+                         * something is really off. */
+
+                        if (IN_SET(errno, ENOENT, EOPNOTSUPP))
+                                return (cached = false);
+
+                        return -errno;
+                }
+
+                fd2 = accept4(fd1, NULL, 0, SOCK_CLOEXEC);
+                if (fd2 < 0) {
+                        if (errno == EOPNOTSUPP)
+                                return (cached = false);
+
+                        return -errno;
+                }
+
+                if (recv(fd2, buf, sizeof(buf), 0) < 0) {
+                        /* On some kernels we get ENOKEY for non-keyed hash functions (such as sha256), let's refuse
+                         * using the API in those cases, since the kernel is
+                         * broken. https://github.com/systemd/systemd/issues/8278 */
+
+                        if (IN_SET(errno, ENOKEY, EOPNOTSUPP))
+                                return (cached = false);
+                }
+
+                cached = true;
+        }
+
+        return cached;
+}
+
+int khash_new_with_key(khash **ret, const char *algorithm, const void *key, size_t key_size) {
+        union {
+                struct sockaddr sa;
+                struct sockaddr_alg alg;
+        } sa = {
+                .alg.salg_family = AF_ALG,
+                .alg.salg_type = "hash",
+        };
+
+        _cleanup_(khash_unrefp) khash *h = NULL;
+        _cleanup_close_ int fd = -1;
+        int supported;
+        ssize_t n;
+
+        assert(ret);
+        assert(key || key_size == 0);
+
+        /* Filter out an empty algorithm early, as we do not support an algorithm by that name. */
+        if (isempty(algorithm))
+                return -EINVAL;
+
+        /* Overly long hash algorithm names we definitely do not support */
+        if (strlen(algorithm) >= sizeof(sa.alg.salg_name))
+                return -EOPNOTSUPP;
+
+        supported = khash_supported();
+        if (supported < 0)
+                return supported;
+        if (supported == 0)
+                return -EOPNOTSUPP;
+
+        fd = socket(AF_ALG, SOCK_SEQPACKET|SOCK_CLOEXEC, 0);
+        if (fd < 0)
+                return -errno;
+
+        strcpy((char*) sa.alg.salg_name, algorithm);
+        if (bind(fd, &sa.sa, sizeof(sa)) < 0) {
+                if (errno == ENOENT)
+                        return -EOPNOTSUPP;
+                return -errno;
+        }
+
+        if (key) {
+                if (setsockopt(fd, SOL_ALG, ALG_SET_KEY, key, key_size) < 0)
+                        return -errno;
+        }
+
+        h = new0(khash, 1);
+        if (!h)
+                return -ENOMEM;
+
+        h->fd = accept4(fd, NULL, 0, SOCK_CLOEXEC);
+        if (h->fd < 0)
+                return -errno;
+
+        h->algorithm = strdup(algorithm);
+        if (!h->algorithm)
+                return -ENOMEM;
+
+        /* Temporary fix for rc kernel bug: https://bugzilla.redhat.com/show_bug.cgi?id=1395896 */
+        (void) send(h->fd, NULL, 0, 0);
+
+        /* Figure out the digest size */
+        n = recv(h->fd, h->digest, sizeof(h->digest), 0);
+        if (n < 0)
+                return -errno;
+        if (n >= LONGEST_DIGEST) /* longer than what we expected? If so, we don't support this */
+                return -EOPNOTSUPP;
+
+        h->digest_size = (size_t) n;
+        h->digest_valid = true;
+
+        /* Temporary fix for rc kernel bug: https://bugzilla.redhat.com/show_bug.cgi?id=1395896 */
+        (void) send(h->fd, NULL, 0, 0);
+
+        *ret = h;
+        h = NULL;
+
+        return 0;
+}
+
+int khash_new(khash **ret, const char *algorithm) {
+        return khash_new_with_key(ret, algorithm, NULL, 0);
+}
+
+khash* khash_unref(khash *h) {
+        if (!h)
+                return NULL;
+
+        safe_close(h->fd);
+        free(h->algorithm);
+        return mfree(h);
+}
+
+int khash_dup(khash *h, khash **ret) {
+        _cleanup_(khash_unrefp) khash *copy = NULL;
+
+        assert(h);
+        assert(ret);
+
+        copy = newdup(khash, h, 1);
+        if (!copy)
+                return -ENOMEM;
+
+        copy->fd = -1;
+        copy->algorithm = strdup(h->algorithm);
+        if (!copy->algorithm)
+                return -ENOMEM;
+
+        copy->fd = accept4(h->fd, NULL, 0, SOCK_CLOEXEC);
+        if (copy->fd < 0)
+                return -errno;
+
+        *ret = TAKE_PTR(copy);
+
+        return 0;
+}
+
+const char *khash_get_algorithm(khash *h) {
+        assert(h);
+
+        return h->algorithm;
+}
+
+size_t khash_get_size(khash *h) {
+        assert(h);
+
+        return h->digest_size;
+}
+
+int khash_reset(khash *h) {
+        ssize_t n;
+
+        assert(h);
+
+        n = send(h->fd, NULL, 0, 0);
+        if (n < 0)
+                return -errno;
+
+        h->digest_valid = false;
+
+        return 0;
+}
+
+int khash_put(khash *h, const void *buffer, size_t size) {
+        ssize_t n;
+
+        assert(h);
+        assert(buffer || size == 0);
+
+        if (size <= 0)
+                return 0;
+
+        n = send(h->fd, buffer, size, MSG_MORE);
+        if (n < 0)
+                return -errno;
+
+        h->digest_valid = false;
+
+        return 0;
+}
+
+int khash_put_iovec(khash *h, const struct iovec *iovec, size_t n) {
+        struct msghdr mh = {
+                mh.msg_iov = (struct iovec*) iovec,
+                mh.msg_iovlen = n,
+        };
+        ssize_t k;
+
+        assert(h);
+        assert(iovec || n == 0);
+
+        if (n <= 0)
+                return 0;
+
+        k = sendmsg(h->fd, &mh, MSG_MORE);
+        if (k < 0)
+                return -errno;
+
+        h->digest_valid = false;
+
+        return 0;
+}
+
+static int retrieve_digest(khash *h) {
+        ssize_t n;
+
+        assert(h);
+
+        if (h->digest_valid)
+                return 0;
+
+        n = recv(h->fd, h->digest, h->digest_size, 0);
+        if (n < 0)
+                return n;
+        if ((size_t) n != h->digest_size) /* digest size changed? */
+                return -EIO;
+
+        h->digest_valid = true;
+
+        return 0;
+}
+
+int khash_digest_data(khash *h, const void **ret) {
+        int r;
+
+        assert(h);
+        assert(ret);
+
+        r = retrieve_digest(h);
+        if (r < 0)
+                return r;
+
+        *ret = h->digest;
+        return 0;
+}
+
+int khash_digest_string(khash *h, char **ret) {
+        int r;
+        char *p;
+
+        assert(h);
+        assert(ret);
+
+        r = retrieve_digest(h);
+        if (r < 0)
+                return r;
+
+        p = hexmem(h->digest, h->digest_size);
+        if (!p)
+                return -ENOMEM;
+
+        *ret = p;
+        return 0;
+}
diff --git a/src/basic/khash.h b/src/basic/khash.h
new file mode 100644
index 0000000..a3013b9
--- /dev/null
+++ b/src/basic/khash.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+
+#include "macro.h"
+
+typedef struct khash khash;
+
+int khash_supported(void);
+
+/* For plain hash functions. Hash functions commonly supported on today's kernels are: crc32c, crct10dif, crc32,
+ * sha224, sha256, sha512, sha384, sha1, md5, md4, sha3-224, sha3-256, sha3-384, sha3-512, and more. */
+int khash_new(khash **ret, const char *algorithm);
+
+/* For keyed hash functions. Hash functions commonly supported on today's kernels are: hmac(sha256), cmac(aes),
+ * cmac(des3_ede), hmac(sha3-512), hmac(sha3-384), hmac(sha3-256), hmac(sha3-224), hmac(rmd160), hmac(rmd128),
+ * hmac(sha224), hmac(sha512), hmac(sha384), hmac(sha1), hmac(md5), and more. */
+int khash_new_with_key(khash **ret, const char *algorithm, const void *key, size_t key_size);
+
+int khash_dup(khash *h, khash **ret);
+khash* khash_unref(khash *h);
+
+const char *khash_get_algorithm(khash *h);
+size_t khash_get_size(khash *h);
+
+int khash_reset(khash *h);
+
+int khash_put(khash *h, const void *buffer, size_t size);
+int khash_put_iovec(khash *h, const struct iovec *iovec, size_t n);
+
+int khash_digest_data(khash *h, const void **ret);
+int khash_digest_string(khash *h, char **ret);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(khash*, khash_unref);
diff --git a/src/basic/label.c b/src/basic/label.c
new file mode 100644
index 0000000..12a7fb0
--- /dev/null
+++ b/src/basic/label.c
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "btrfs-util.h"
+#include "label.h"
+#include "macro.h"
+#include "selinux-util.h"
+#include "smack-util.h"
+
+int label_fix(const char *path, LabelFixFlags flags) {
+        int r, q;
+
+        r = mac_selinux_fix(path, flags);
+        q = mac_smack_fix(path, flags);
+
+        if (r < 0)
+                return r;
+        if (q < 0)
+                return q;
+
+        return 0;
+}
+
+int symlink_label(const char *old_path, const char *new_path) {
+        int r;
+
+        assert(old_path);
+        assert(new_path);
+
+        r = mac_selinux_create_file_prepare(new_path, S_IFLNK);
+        if (r < 0)
+                return r;
+
+        if (symlink(old_path, new_path) < 0)
+                r = -errno;
+
+        mac_selinux_create_file_clear();
+
+        if (r < 0)
+                return r;
+
+        return mac_smack_fix(new_path, 0);
+}
+
+int btrfs_subvol_make_label(const char *path) {
+        int r;
+
+        assert(path);
+
+        r = mac_selinux_create_file_prepare(path, S_IFDIR);
+        if (r < 0)
+                return r;
+
+        r = btrfs_subvol_make(path);
+        mac_selinux_create_file_clear();
+
+        if (r < 0)
+                return r;
+
+        return mac_smack_fix(path, 0);
+}
diff --git a/src/basic/label.h b/src/basic/label.h
new file mode 100644
index 0000000..594fd65
--- /dev/null
+++ b/src/basic/label.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <sys/types.h>
+
+typedef enum LabelFixFlags {
+        LABEL_IGNORE_ENOENT = 1 << 0,
+        LABEL_IGNORE_EROFS  = 1 << 1,
+} LabelFixFlags;
+
+int label_fix(const char *path, LabelFixFlags flags);
+
+int mkdir_label(const char *path, mode_t mode);
+int mkdirat_label(int dirfd, const char *path, mode_t mode);
+int symlink_label(const char *old_path, const char *new_path);
+
+int btrfs_subvol_make_label(const char *path);
diff --git a/src/basic/list.h b/src/basic/list.h
new file mode 100644
index 0000000..f7f9700
--- /dev/null
+++ b/src/basic/list.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "macro.h"
+
+/* The head of the linked list. Use this in the structure that shall
+ * contain the head of the linked list */
+#define LIST_HEAD(t,name)                                               \
+        t *name
+
+/* The pointers in the linked list's items. Use this in the item structure */
+#define LIST_FIELDS(t,name)                                             \
+        t *name##_next, *name##_prev
+
+/* Initialize the list's head */
+#define LIST_HEAD_INIT(head)                                            \
+        do {                                                            \
+                (head) = NULL;                                          \
+        } while (false)
+
+/* Initialize a list item */
+#define LIST_INIT(name,item)                                            \
+        do {                                                            \
+                typeof(*(item)) *_item = (item);                        \
+                assert(_item);                                          \
+                _item->name##_prev = _item->name##_next = NULL;         \
+        } while (false)
+
+/* Prepend an item to the list */
+#define LIST_PREPEND(name,head,item)                                    \
+        do {                                                            \
+                typeof(*(head)) **_head = &(head), *_item = (item);     \
+                assert(_item);                                          \
+                if ((_item->name##_next = *_head))                      \
+                        _item->name##_next->name##_prev = _item;        \
+                _item->name##_prev = NULL;                              \
+                *_head = _item;                                         \
+        } while (false)
+
+/* Append an item to the list */
+#define LIST_APPEND(name,head,item)                                     \
+        do {                                                            \
+                typeof(*(head)) **_hhead = &(head), *_tail;             \
+                LIST_FIND_TAIL(name, *_hhead, _tail);                   \
+                LIST_INSERT_AFTER(name, *_hhead, _tail, item);          \
+        } while (false)
+
+/* Remove an item from the list */
+#define LIST_REMOVE(name,head,item)                                     \
+        do {                                                            \
+                typeof(*(head)) **_head = &(head), *_item = (item);     \
+                assert(_item);                                          \
+                if (_item->name##_next)                                 \
+                        _item->name##_next->name##_prev = _item->name##_prev; \
+                if (_item->name##_prev)                                 \
+                        _item->name##_prev->name##_next = _item->name##_next; \
+                else {                                                  \
+                        assert(*_head == _item);                        \
+                        *_head = _item->name##_next;                    \
+                }                                                       \
+                _item->name##_next = _item->name##_prev = NULL;         \
+        } while (false)
+
+/* Find the head of the list */
+#define LIST_FIND_HEAD(name,item,head)                                  \
+        do {                                                            \
+                typeof(*(item)) *_item = (item);                        \
+                if (!_item)                                             \
+                        (head) = NULL;                                  \
+                else {                                                  \
+                        while (_item->name##_prev)                      \
+                                _item = _item->name##_prev;             \
+                        (head) = _item;                                 \
+                }                                                       \
+        } while (false)
+
+/* Find the tail of the list */
+#define LIST_FIND_TAIL(name,item,tail)                                  \
+        do {                                                            \
+                typeof(*(item)) *_item = (item);                        \
+                if (!_item)                                             \
+                        (tail) = NULL;                                  \
+                else {                                                  \
+                        while (_item->name##_next)                      \
+                                _item = _item->name##_next;             \
+                        (tail) = _item;                                 \
+                }                                                       \
+        } while (false)
+
+/* Insert an item after another one (a = where, b = what) */
+#define LIST_INSERT_AFTER(name,head,a,b)                                \
+        do {                                                            \
+                typeof(*(head)) **_head = &(head), *_a = (a), *_b = (b); \
+                assert(_b);                                             \
+                if (!_a) {                                              \
+                        if ((_b->name##_next = *_head))                 \
+                                _b->name##_next->name##_prev = _b;      \
+                        _b->name##_prev = NULL;                         \
+                        *_head = _b;                                    \
+                } else {                                                \
+                        if ((_b->name##_next = _a->name##_next))        \
+                                _b->name##_next->name##_prev = _b;      \
+                        _b->name##_prev = _a;                           \
+                        _a->name##_next = _b;                           \
+                }                                                       \
+        } while (false)
+
+/* Insert an item before another one (a = where, b = what) */
+#define LIST_INSERT_BEFORE(name,head,a,b)                               \
+        do {                                                            \
+                typeof(*(head)) **_head = &(head), *_a = (a), *_b = (b); \
+                assert(_b);                                             \
+                if (!_a) {                                              \
+                        if (!*_head) {                                  \
+                                _b->name##_next = NULL;                 \
+                                _b->name##_prev = NULL;                 \
+                                *_head = _b;                            \
+                        } else {                                        \
+                                typeof(*(head)) *_tail = (head);        \
+                                while (_tail->name##_next)              \
+                                        _tail = _tail->name##_next;     \
+                                _b->name##_next = NULL;                 \
+                                _b->name##_prev = _tail;                \
+                                _tail->name##_next = _b;                \
+                        }                                               \
+                } else {                                                \
+                        if ((_b->name##_prev = _a->name##_prev))        \
+                                _b->name##_prev->name##_next = _b;      \
+                        else                                            \
+                                *_head = _b;                            \
+                        _b->name##_next = _a;                           \
+                        _a->name##_prev = _b;                           \
+                }                                                       \
+        } while (false)
+
+#define LIST_JUST_US(name,item)                                         \
+        (!(item)->name##_prev && !(item)->name##_next)                  \
+
+#define LIST_FOREACH(name,i,head)                                       \
+        for ((i) = (head); (i); (i) = (i)->name##_next)
+
+#define LIST_FOREACH_SAFE(name,i,n,head)                                \
+        for ((i) = (head); (i) && (((n) = (i)->name##_next), 1); (i) = (n))
+
+#define LIST_FOREACH_BEFORE(name,i,p)                                   \
+        for ((i) = (p)->name##_prev; (i); (i) = (i)->name##_prev)
+
+#define LIST_FOREACH_AFTER(name,i,p)                                    \
+        for ((i) = (p)->name##_next; (i); (i) = (i)->name##_next)
+
+/* Iterate through all the members of the list p is included in, but skip over p */
+#define LIST_FOREACH_OTHERS(name,i,p)                                   \
+        for (({                                                         \
+                (i) = (p);                                              \
+                while ((i) && (i)->name##_prev)                         \
+                        (i) = (i)->name##_prev;                         \
+                if ((i) == (p))                                         \
+                        (i) = (p)->name##_next;                         \
+             });                                                        \
+             (i);                                                       \
+             (i) = (i)->name##_next == (p) ? (p)->name##_next : (i)->name##_next)
+
+/* Loop starting from p->next until p->prev.
+   p can be adjusted meanwhile. */
+#define LIST_LOOP_BUT_ONE(name,i,head,p)                                \
+        for ((i) = (p)->name##_next ? (p)->name##_next : (head);        \
+             (i) != (p);                                                \
+             (i) = (i)->name##_next ? (i)->name##_next : (head))
+
+#define LIST_IS_EMPTY(head)                                             \
+        (!(head))
diff --git a/src/basic/locale-util.c b/src/basic/locale-util.c
new file mode 100644
index 0000000..fc1577a
--- /dev/null
+++ b/src/basic/locale-util.c
@@ -0,0 +1,460 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <ftw.h>
+#include <langinfo.h>
+#include <libintl.h>
+#include <locale.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include "def.h"
+#include "dirent-util.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "hashmap.h"
+#include "locale-util.h"
+#include "path-util.h"
+#include "set.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "utf8.h"
+
+static int add_locales_from_archive(Set *locales) {
+        /* Stolen from glibc... */
+
+        struct locarhead {
+                uint32_t magic;
+                /* Serial number.  */
+                uint32_t serial;
+                /* Name hash table.  */
+                uint32_t namehash_offset;
+                uint32_t namehash_used;
+                uint32_t namehash_size;
+                /* String table.  */
+                uint32_t string_offset;
+                uint32_t string_used;
+                uint32_t string_size;
+                /* Table with locale records.  */
+                uint32_t locrectab_offset;
+                uint32_t locrectab_used;
+                uint32_t locrectab_size;
+                /* MD5 sum hash table.  */
+                uint32_t sumhash_offset;
+                uint32_t sumhash_used;
+                uint32_t sumhash_size;
+        };
+
+        struct namehashent {
+                /* Hash value of the name.  */
+                uint32_t hashval;
+                /* Offset of the name in the string table.  */
+                uint32_t name_offset;
+                /* Offset of the locale record.  */
+                uint32_t locrec_offset;
+        };
+
+        const struct locarhead *h;
+        const struct namehashent *e;
+        const void *p = MAP_FAILED;
+        _cleanup_close_ int fd = -1;
+        size_t sz = 0;
+        struct stat st;
+        size_t i;
+        int r;
+
+        fd = open("/usr/lib/locale/locale-archive", O_RDONLY|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return errno == ENOENT ? 0 : -errno;
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (!S_ISREG(st.st_mode))
+                return -EBADMSG;
+
+        if (st.st_size < (off_t) sizeof(struct locarhead))
+                return -EBADMSG;
+
+        p = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
+        if (p == MAP_FAILED)
+                return -errno;
+
+        h = (const struct locarhead *) p;
+        if (h->magic != 0xde020109 ||
+            h->namehash_offset + h->namehash_size > st.st_size ||
+            h->string_offset + h->string_size > st.st_size ||
+            h->locrectab_offset + h->locrectab_size > st.st_size ||
+            h->sumhash_offset + h->sumhash_size > st.st_size) {
+                r = -EBADMSG;
+                goto finish;
+        }
+
+        e = (const struct namehashent*) ((const uint8_t*) p + h->namehash_offset);
+        for (i = 0; i < h->namehash_size; i++) {
+                char *z;
+
+                if (e[i].locrec_offset == 0)
+                        continue;
+
+                if (!utf8_is_valid((char*) p + e[i].name_offset))
+                        continue;
+
+                z = strdup((char*) p + e[i].name_offset);
+                if (!z) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                r = set_consume(locales, z);
+                if (r < 0)
+                        goto finish;
+        }
+
+        r = 0;
+
+ finish:
+        if (p != MAP_FAILED)
+                munmap((void*) p, sz);
+
+        return r;
+}
+
+static int add_locales_from_libdir (Set *locales) {
+        _cleanup_closedir_ DIR *dir = NULL;
+        struct dirent *entry;
+        int r;
+
+        dir = opendir("/usr/lib/locale");
+        if (!dir)
+                return errno == ENOENT ? 0 : -errno;
+
+        FOREACH_DIRENT(entry, dir, return -errno) {
+                char *z;
+
+                dirent_ensure_type(dir, entry);
+
+                if (entry->d_type != DT_DIR)
+                        continue;
+
+                z = strdup(entry->d_name);
+                if (!z)
+                        return -ENOMEM;
+
+                r = set_consume(locales, z);
+                if (r < 0 && r != -EEXIST)
+                        return r;
+        }
+
+        return 0;
+}
+
+int get_locales(char ***ret) {
+        _cleanup_set_free_ Set *locales = NULL;
+        _cleanup_strv_free_ char **l = NULL;
+        int r;
+
+        locales = set_new(&string_hash_ops);
+        if (!locales)
+                return -ENOMEM;
+
+        r = add_locales_from_archive(locales);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        r = add_locales_from_libdir(locales);
+        if (r < 0)
+                return r;
+
+        l = set_get_strv(locales);
+        if (!l)
+                return -ENOMEM;
+
+        strv_sort(l);
+
+        *ret = TAKE_PTR(l);
+
+        return 0;
+}
+
+bool locale_is_valid(const char *name) {
+
+        if (isempty(name))
+                return false;
+
+        if (strlen(name) >= 128)
+                return false;
+
+        if (!utf8_is_valid(name))
+                return false;
+
+        if (!filename_is_valid(name))
+                return false;
+
+        if (!string_is_safe(name))
+                return false;
+
+        return true;
+}
+
+void init_gettext(void) {
+        setlocale(LC_ALL, "");
+        textdomain(GETTEXT_PACKAGE);
+}
+
+bool is_locale_utf8(void) {
+        const char *set;
+        static int cached_answer = -1;
+
+        /* Note that we default to 'true' here, since today UTF8 is
+         * pretty much supported everywhere. */
+
+        if (cached_answer >= 0)
+                goto out;
+
+        if (!setlocale(LC_ALL, "")) {
+                cached_answer = true;
+                goto out;
+        }
+
+        set = nl_langinfo(CODESET);
+        if (!set) {
+                cached_answer = true;
+                goto out;
+        }
+
+        if (streq(set, "UTF-8")) {
+                cached_answer = true;
+                goto out;
+        }
+
+        /* For LC_CTYPE=="C" return true, because CTYPE is effectly
+         * unset and everything can do to UTF-8 nowadays. */
+        set = setlocale(LC_CTYPE, NULL);
+        if (!set) {
+                cached_answer = true;
+                goto out;
+        }
+
+        /* Check result, but ignore the result if C was set
+         * explicitly. */
+        cached_answer =
+                STR_IN_SET(set, "C", "POSIX") &&
+                !getenv("LC_ALL") &&
+                !getenv("LC_CTYPE") &&
+                !getenv("LANG");
+
+out:
+        return (bool) cached_answer;
+}
+
+static thread_local Set *keymaps = NULL;
+
+static int nftw_cb(
+                const char *fpath,
+                const struct stat *sb,
+                int tflag,
+                struct FTW *ftwbuf) {
+
+        char *p, *e;
+        int r;
+
+        if (tflag != FTW_F)
+                return 0;
+
+        if (!endswith(fpath, ".map") &&
+            !endswith(fpath, ".map.gz"))
+                return 0;
+
+        p = strdup(basename(fpath));
+        if (!p)
+                return FTW_STOP;
+
+        e = endswith(p, ".map");
+        if (e)
+                *e = 0;
+
+        e = endswith(p, ".map.gz");
+        if (e)
+                *e = 0;
+
+        r = set_consume(keymaps, p);
+        if (r < 0 && r != -EEXIST)
+                return r;
+
+        return 0;
+}
+
+int get_keymaps(char ***ret) {
+        _cleanup_strv_free_ char **l = NULL;
+        const char *dir;
+        int r;
+
+        keymaps = set_new(&string_hash_ops);
+        if (!keymaps)
+                return -ENOMEM;
+
+        NULSTR_FOREACH(dir, KBD_KEYMAP_DIRS) {
+                r = nftw(dir, nftw_cb, 20, FTW_PHYS|FTW_ACTIONRETVAL);
+
+                if (r == FTW_STOP)
+                        log_debug("Directory not found %s", dir);
+                else if (r < 0)
+                        log_debug_errno(r, "Can't add keymap: %m");
+        }
+
+        l = set_get_strv(keymaps);
+        if (!l) {
+                set_free_free(keymaps);
+                return -ENOMEM;
+        }
+
+        set_free(keymaps);
+
+        if (strv_isempty(l))
+                return -ENOENT;
+
+        strv_sort(l);
+
+        *ret = TAKE_PTR(l);
+
+        return 0;
+}
+
+bool keymap_is_valid(const char *name) {
+
+        if (isempty(name))
+                return false;
+
+        if (strlen(name) >= 128)
+                return false;
+
+        if (!utf8_is_valid(name))
+                return false;
+
+        if (!filename_is_valid(name))
+                return false;
+
+        if (!string_is_safe(name))
+                return false;
+
+        return true;
+}
+
+static bool emoji_enabled(void) {
+        static int cached_emoji_enabled = -1;
+
+        if (cached_emoji_enabled < 0) {
+                int val;
+
+                val = getenv_bool("SYSTEMD_EMOJI");
+                if (val < 0)
+                        cached_emoji_enabled =
+                                is_locale_utf8() &&
+                                !STRPTR_IN_SET(getenv("TERM"), "dumb", "linux");
+                else
+                        cached_emoji_enabled = val;
+        }
+
+        return cached_emoji_enabled;
+}
+
+const char *special_glyph(SpecialGlyph code) {
+
+        /* A list of a number of interesting unicode glyphs we can use to decorate our output. It's probably wise to be
+         * conservative here, and primarily stick to the glyphs defined in the eurlatgr font, so that display still
+         * works reasonably well on the Linux console. For details see:
+         *
+         * http://git.altlinux.org/people/legion/packages/kbd.git?p=kbd.git;a=blob;f=data/consolefonts/README.eurlatgr
+         */
+
+        static const char* const draw_table[2][_SPECIAL_GLYPH_MAX] = {
+                /* ASCII fallback */
+                [false] = {
+                        [SPECIAL_GLYPH_TREE_VERTICAL]           = "| ",
+                        [SPECIAL_GLYPH_TREE_BRANCH]             = "|-",
+                        [SPECIAL_GLYPH_TREE_RIGHT]              = "`-",
+                        [SPECIAL_GLYPH_TREE_SPACE]              = "  ",
+                        [SPECIAL_GLYPH_TRIANGULAR_BULLET]       = ">",
+                        [SPECIAL_GLYPH_BLACK_CIRCLE]            = "*",
+                        [SPECIAL_GLYPH_BULLET]                  = "*",
+                        [SPECIAL_GLYPH_ARROW]                   = "->",
+                        [SPECIAL_GLYPH_MDASH]                   = "-",
+                        [SPECIAL_GLYPH_ELLIPSIS]                = "...",
+                        [SPECIAL_GLYPH_MU]                      = "u",
+                        [SPECIAL_GLYPH_CHECK_MARK]              = "+",
+                        [SPECIAL_GLYPH_CROSS_MARK]              = "-",
+                        [SPECIAL_GLYPH_ECSTATIC_SMILEY]         = ":-]",
+                        [SPECIAL_GLYPH_HAPPY_SMILEY]            = ":-}",
+                        [SPECIAL_GLYPH_SLIGHTLY_HAPPY_SMILEY]   = ":-)",
+                        [SPECIAL_GLYPH_NEUTRAL_SMILEY]          = ":-|",
+                        [SPECIAL_GLYPH_SLIGHTLY_UNHAPPY_SMILEY] = ":-(",
+                        [SPECIAL_GLYPH_UNHAPPY_SMILEY]          = ":-{️",
+                        [SPECIAL_GLYPH_DEPRESSED_SMILEY]        = ":-[",
+                },
+
+                /* UTF-8 */
+                [true] = {
+                        [SPECIAL_GLYPH_TREE_VERTICAL]           = "\342\224\202 ",            /* │  */
+                        [SPECIAL_GLYPH_TREE_BRANCH]             = "\342\224\234\342\224\200", /* ├─ */
+                        [SPECIAL_GLYPH_TREE_RIGHT]              = "\342\224\224\342\224\200", /* └─ */
+                        [SPECIAL_GLYPH_TREE_SPACE]              = "  ",                       /*    */
+                        [SPECIAL_GLYPH_TRIANGULAR_BULLET]       = "\342\200\243",             /* ‣ */
+                        [SPECIAL_GLYPH_BLACK_CIRCLE]            = "\342\227\217",             /* ● */
+                        [SPECIAL_GLYPH_BULLET]                  = "\342\200\242",             /* • */
+                        [SPECIAL_GLYPH_ARROW]                   = "\342\206\222",             /* → */
+                        [SPECIAL_GLYPH_MDASH]                   = "\342\200\223",             /* – */
+                        [SPECIAL_GLYPH_ELLIPSIS]                = "\342\200\246",             /* … */
+                        [SPECIAL_GLYPH_MU]                      = "\316\274",                 /* μ */
+                        [SPECIAL_GLYPH_CHECK_MARK]              = "\342\234\223",             /* ✓ */
+                        [SPECIAL_GLYPH_CROSS_MARK]              = "\342\234\227",             /* ✗ */
+                        [SPECIAL_GLYPH_ECSTATIC_SMILEY]         = "\360\237\230\207",         /* 😇 */
+                        [SPECIAL_GLYPH_HAPPY_SMILEY]            = "\360\237\230\200",         /* 😀 */
+                        [SPECIAL_GLYPH_SLIGHTLY_HAPPY_SMILEY]   = "\360\237\231\202",         /* 🙂 */
+                        [SPECIAL_GLYPH_NEUTRAL_SMILEY]          = "\360\237\230\220",         /* 😐 */
+                        [SPECIAL_GLYPH_SLIGHTLY_UNHAPPY_SMILEY] = "\360\237\231\201",         /* 🙁 */
+                        [SPECIAL_GLYPH_UNHAPPY_SMILEY]          = "\360\237\230\250",         /* 😨️️ */
+                        [SPECIAL_GLYPH_DEPRESSED_SMILEY]        = "\360\237\244\242",         /* 🤢 */
+                },
+        };
+
+        assert(code < _SPECIAL_GLYPH_MAX);
+
+        return draw_table[code >= _SPECIAL_GLYPH_FIRST_SMILEY ? emoji_enabled() : is_locale_utf8()][code];
+}
+
+void locale_variables_free(char *l[_VARIABLE_LC_MAX]) {
+        LocaleVariable i;
+
+        if (!l)
+                return;
+
+        for (i = 0; i < _VARIABLE_LC_MAX; i++)
+                l[i] = mfree(l[i]);
+}
+
+static const char * const locale_variable_table[_VARIABLE_LC_MAX] = {
+        [VARIABLE_LANG] = "LANG",
+        [VARIABLE_LANGUAGE] = "LANGUAGE",
+        [VARIABLE_LC_CTYPE] = "LC_CTYPE",
+        [VARIABLE_LC_NUMERIC] = "LC_NUMERIC",
+        [VARIABLE_LC_TIME] = "LC_TIME",
+        [VARIABLE_LC_COLLATE] = "LC_COLLATE",
+        [VARIABLE_LC_MONETARY] = "LC_MONETARY",
+        [VARIABLE_LC_MESSAGES] = "LC_MESSAGES",
+        [VARIABLE_LC_PAPER] = "LC_PAPER",
+        [VARIABLE_LC_NAME] = "LC_NAME",
+        [VARIABLE_LC_ADDRESS] = "LC_ADDRESS",
+        [VARIABLE_LC_TELEPHONE] = "LC_TELEPHONE",
+        [VARIABLE_LC_MEASUREMENT] = "LC_MEASUREMENT",
+        [VARIABLE_LC_IDENTIFICATION] = "LC_IDENTIFICATION"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(locale_variable, LocaleVariable);
diff --git a/src/basic/locale-util.h b/src/basic/locale-util.h
new file mode 100644
index 0000000..e64f0ce
--- /dev/null
+++ b/src/basic/locale-util.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <libintl.h>
+#include <stdbool.h>
+#include <locale.h>
+
+#include "macro.h"
+
+typedef enum LocaleVariable {
+        /* We don't list LC_ALL here on purpose. People should be
+         * using LANG instead. */
+
+        VARIABLE_LANG,
+        VARIABLE_LANGUAGE,
+        VARIABLE_LC_CTYPE,
+        VARIABLE_LC_NUMERIC,
+        VARIABLE_LC_TIME,
+        VARIABLE_LC_COLLATE,
+        VARIABLE_LC_MONETARY,
+        VARIABLE_LC_MESSAGES,
+        VARIABLE_LC_PAPER,
+        VARIABLE_LC_NAME,
+        VARIABLE_LC_ADDRESS,
+        VARIABLE_LC_TELEPHONE,
+        VARIABLE_LC_MEASUREMENT,
+        VARIABLE_LC_IDENTIFICATION,
+        _VARIABLE_LC_MAX,
+        _VARIABLE_LC_INVALID = -1
+} LocaleVariable;
+
+int get_locales(char ***l);
+bool locale_is_valid(const char *name);
+
+#define _(String) gettext(String)
+#define N_(String) String
+void init_gettext(void);
+
+bool is_locale_utf8(void);
+
+typedef enum {
+        SPECIAL_GLYPH_TREE_VERTICAL,
+        SPECIAL_GLYPH_TREE_BRANCH,
+        SPECIAL_GLYPH_TREE_RIGHT,
+        SPECIAL_GLYPH_TREE_SPACE,
+        SPECIAL_GLYPH_TRIANGULAR_BULLET,
+        SPECIAL_GLYPH_BLACK_CIRCLE,
+        SPECIAL_GLYPH_BULLET,
+        SPECIAL_GLYPH_ARROW,
+        SPECIAL_GLYPH_MDASH,
+        SPECIAL_GLYPH_ELLIPSIS,
+        SPECIAL_GLYPH_MU,
+        SPECIAL_GLYPH_CHECK_MARK,
+        SPECIAL_GLYPH_CROSS_MARK,
+        _SPECIAL_GLYPH_FIRST_SMILEY,
+        SPECIAL_GLYPH_ECSTATIC_SMILEY = _SPECIAL_GLYPH_FIRST_SMILEY,
+        SPECIAL_GLYPH_HAPPY_SMILEY,
+        SPECIAL_GLYPH_SLIGHTLY_HAPPY_SMILEY,
+        SPECIAL_GLYPH_NEUTRAL_SMILEY,
+        SPECIAL_GLYPH_SLIGHTLY_UNHAPPY_SMILEY,
+        SPECIAL_GLYPH_UNHAPPY_SMILEY,
+        SPECIAL_GLYPH_DEPRESSED_SMILEY,
+        _SPECIAL_GLYPH_MAX
+} SpecialGlyph;
+
+const char *special_glyph(SpecialGlyph code) _const_;
+
+const char* locale_variable_to_string(LocaleVariable i) _const_;
+LocaleVariable locale_variable_from_string(const char *s) _pure_;
+
+int get_keymaps(char ***l);
+bool keymap_is_valid(const char *name);
+
+static inline void freelocalep(locale_t *p) {
+        if (*p == (locale_t) 0)
+                return;
+
+        freelocale(*p);
+}
+
+void locale_variables_free(char* l[_VARIABLE_LC_MAX]);
+static inline void locale_variables_freep(char*(*l)[_VARIABLE_LC_MAX]) {
+        locale_variables_free(*l);
+}
diff --git a/src/basic/log.c b/src/basic/log.c
new file mode 100644
index 0000000..0486027
--- /dev/null
+++ b/src/basic/log.c
@@ -0,0 +1,1324 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/signalfd.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/uio.h>
+#include <sys/un.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "sd-messages.h"
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "io-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "proc-cmdline.h"
+#include "process-util.h"
+#include "signal-util.h"
+#include "socket-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "syslog-util.h"
+#include "terminal-util.h"
+#include "time-util.h"
+#include "utf8.h"
+#include "util.h"
+
+#define SNDBUF_SIZE (8*1024*1024)
+
+static LogTarget log_target = LOG_TARGET_CONSOLE;
+static int log_max_level[] = {LOG_INFO, LOG_INFO};
+assert_cc(ELEMENTSOF(log_max_level) == _LOG_REALM_MAX);
+static int log_facility = LOG_DAEMON;
+
+static int console_fd = STDERR_FILENO;
+static int syslog_fd = -1;
+static int kmsg_fd = -1;
+static int journal_fd = -1;
+
+static bool syslog_is_stream = false;
+
+static bool show_color = false;
+static bool show_location = false;
+
+static bool upgrade_syslog_to_journal = false;
+static bool always_reopen_console = false;
+static bool open_when_needed = false;
+static bool prohibit_ipc = false;
+
+/* Akin to glibc's __abort_msg; which is private and we hence cannot
+ * use here. */
+static char *log_abort_msg = NULL;
+
+/* An assert to use in logging functions that does not call recursively
+ * into our logging functions (since that might lead to a loop). */
+#define assert_raw(expr)                                                \
+        do {                                                            \
+                if (_unlikely_(!(expr))) {                              \
+                        fputs(#expr "\n", stderr);                      \
+                        abort();                                        \
+                }                                                       \
+        } while (false)
+
+static void log_close_console(void) {
+        console_fd = safe_close_above_stdio(console_fd);
+}
+
+static int log_open_console(void) {
+
+        if (!always_reopen_console) {
+                console_fd = STDERR_FILENO;
+                return 0;
+        }
+
+        if (console_fd < 3) {
+                console_fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
+                if (console_fd < 0)
+                        return console_fd;
+
+                console_fd = fd_move_above_stdio(console_fd);
+        }
+
+        return 0;
+}
+
+static void log_close_kmsg(void) {
+        kmsg_fd = safe_close(kmsg_fd);
+}
+
+static int log_open_kmsg(void) {
+
+        if (kmsg_fd >= 0)
+                return 0;
+
+        kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC);
+        if (kmsg_fd < 0)
+                return -errno;
+
+        kmsg_fd = fd_move_above_stdio(kmsg_fd);
+        return 0;
+}
+
+static void log_close_syslog(void) {
+        syslog_fd = safe_close(syslog_fd);
+}
+
+static int create_log_socket(int type) {
+        struct timeval tv;
+        int fd;
+
+        fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0);
+        if (fd < 0)
+                return -errno;
+
+        fd = fd_move_above_stdio(fd);
+        (void) fd_inc_sndbuf(fd, SNDBUF_SIZE);
+
+        /* We need a blocking fd here since we'd otherwise lose messages way too early. However, let's not hang forever
+         * in the unlikely case of a deadlock. */
+        if (getpid_cached() == 1)
+                timeval_store(&tv, 10 * USEC_PER_MSEC);
+        else
+                timeval_store(&tv, 10 * USEC_PER_SEC);
+        (void) setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
+
+        return fd;
+}
+
+static int log_open_syslog(void) {
+
+        static const union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/dev/log",
+        };
+
+        int r;
+
+        if (syslog_fd >= 0)
+                return 0;
+
+        syslog_fd = create_log_socket(SOCK_DGRAM);
+        if (syslog_fd < 0) {
+                r = syslog_fd;
+                goto fail;
+        }
+
+        if (connect(syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
+                safe_close(syslog_fd);
+
+                /* Some legacy syslog systems still use stream
+                 * sockets. They really shouldn't. But what can we
+                 * do... */
+                syslog_fd = create_log_socket(SOCK_STREAM);
+                if (syslog_fd < 0) {
+                        r = syslog_fd;
+                        goto fail;
+                }
+
+                if (connect(syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
+                        r = -errno;
+                        goto fail;
+                }
+
+                syslog_is_stream = true;
+        } else
+                syslog_is_stream = false;
+
+        return 0;
+
+fail:
+        log_close_syslog();
+        return r;
+}
+
+static void log_close_journal(void) {
+        journal_fd = safe_close(journal_fd);
+}
+
+static int log_open_journal(void) {
+
+        static const union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/run/systemd/journal/socket",
+        };
+
+        int r;
+
+        if (journal_fd >= 0)
+                return 0;
+
+        journal_fd = create_log_socket(SOCK_DGRAM);
+        if (journal_fd < 0) {
+                r = journal_fd;
+                goto fail;
+        }
+
+        if (connect(journal_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
+                r = -errno;
+                goto fail;
+        }
+
+        return 0;
+
+fail:
+        log_close_journal();
+        return r;
+}
+
+int log_open(void) {
+        int r;
+
+        /* Do not call from library code. */
+
+        /* If we don't use the console we close it here, to not get
+         * killed by SAK. If we don't use syslog we close it here so
+         * that we are not confused by somebody deleting the socket in
+         * the fs, and to make sure we don't use it if prohibit_ipc is
+         * set. If we don't use /dev/kmsg we still keep it open,
+         * because there is no reason to close it. */
+
+        if (log_target == LOG_TARGET_NULL) {
+                log_close_journal();
+                log_close_syslog();
+                log_close_console();
+                return 0;
+        }
+
+        if (log_target != LOG_TARGET_AUTO ||
+            getpid_cached() == 1 ||
+            isatty(STDERR_FILENO) <= 0) {
+
+                if (!prohibit_ipc &&
+                    IN_SET(log_target, LOG_TARGET_AUTO,
+                                       LOG_TARGET_JOURNAL_OR_KMSG,
+                                       LOG_TARGET_JOURNAL)) {
+                        r = log_open_journal();
+                        if (r >= 0) {
+                                log_close_syslog();
+                                log_close_console();
+                                return r;
+                        }
+                }
+
+                if (!prohibit_ipc &&
+                    IN_SET(log_target, LOG_TARGET_SYSLOG_OR_KMSG,
+                                       LOG_TARGET_SYSLOG)) {
+                        r = log_open_syslog();
+                        if (r >= 0) {
+                                log_close_journal();
+                                log_close_console();
+                                return r;
+                        }
+                }
+
+                if (IN_SET(log_target, LOG_TARGET_AUTO,
+                                       LOG_TARGET_JOURNAL_OR_KMSG,
+                                       LOG_TARGET_SYSLOG_OR_KMSG,
+                                       LOG_TARGET_KMSG)) {
+                        r = log_open_kmsg();
+                        if (r >= 0) {
+                                log_close_journal();
+                                log_close_syslog();
+                                log_close_console();
+                                return r;
+                        }
+                }
+        }
+
+        log_close_journal();
+        log_close_syslog();
+
+        return log_open_console();
+}
+
+void log_set_target(LogTarget target) {
+        assert(target >= 0);
+        assert(target < _LOG_TARGET_MAX);
+
+        if (upgrade_syslog_to_journal) {
+                if (target == LOG_TARGET_SYSLOG)
+                        target = LOG_TARGET_JOURNAL;
+                else if (target == LOG_TARGET_SYSLOG_OR_KMSG)
+                        target = LOG_TARGET_JOURNAL_OR_KMSG;
+        }
+
+        log_target = target;
+}
+
+void log_close(void) {
+        /* Do not call from library code. */
+
+        log_close_journal();
+        log_close_syslog();
+        log_close_kmsg();
+        log_close_console();
+}
+
+void log_forget_fds(void) {
+        /* Do not call from library code. */
+
+        console_fd = kmsg_fd = syslog_fd = journal_fd = -1;
+}
+
+void log_set_max_level_realm(LogRealm realm, int level) {
+        assert((level & LOG_PRIMASK) == level);
+        assert(realm < ELEMENTSOF(log_max_level));
+
+        log_max_level[realm] = level;
+}
+
+void log_set_facility(int facility) {
+        log_facility = facility;
+}
+
+static int write_to_console(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *buffer) {
+
+        char location[256], prefix[1 + DECIMAL_STR_MAX(int) + 2];
+        struct iovec iovec[6] = {};
+        bool highlight;
+        size_t n = 0;
+
+        if (console_fd < 0)
+                return 0;
+
+        if (log_target == LOG_TARGET_CONSOLE_PREFIXED) {
+                xsprintf(prefix, "<%i>", level);
+                iovec[n++] = IOVEC_MAKE_STRING(prefix);
+        }
+
+        highlight = LOG_PRI(level) <= LOG_ERR && show_color;
+
+        if (show_location) {
+                (void) snprintf(location, sizeof location, "(%s:%i) ", file, line);
+                iovec[n++] = IOVEC_MAKE_STRING(location);
+        }
+
+        if (highlight)
+                iovec[n++] = IOVEC_MAKE_STRING(ANSI_HIGHLIGHT_RED);
+        iovec[n++] = IOVEC_MAKE_STRING(buffer);
+        if (highlight)
+                iovec[n++] = IOVEC_MAKE_STRING(ANSI_NORMAL);
+        iovec[n++] = IOVEC_MAKE_STRING("\n");
+
+        if (writev(console_fd, iovec, n) < 0) {
+
+                if (errno == EIO && getpid_cached() == 1) {
+
+                        /* If somebody tried to kick us from our
+                         * console tty (via vhangup() or suchlike),
+                         * try to reconnect */
+
+                        log_close_console();
+                        log_open_console();
+
+                        if (console_fd < 0)
+                                return 0;
+
+                        if (writev(console_fd, iovec, n) < 0)
+                                return -errno;
+                } else
+                        return -errno;
+        }
+
+        return 1;
+}
+
+static int write_to_syslog(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *buffer) {
+
+        char header_priority[2 + DECIMAL_STR_MAX(int) + 1],
+             header_time[64],
+             header_pid[4 + DECIMAL_STR_MAX(pid_t) + 1];
+        struct iovec iovec[5] = {};
+        struct msghdr msghdr = {
+                .msg_iov = iovec,
+                .msg_iovlen = ELEMENTSOF(iovec),
+        };
+        time_t t;
+        struct tm tm;
+
+        if (syslog_fd < 0)
+                return 0;
+
+        xsprintf(header_priority, "<%i>", level);
+
+        t = (time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC);
+        if (!localtime_r(&t, &tm))
+                return -EINVAL;
+
+        if (strftime(header_time, sizeof(header_time), "%h %e %T ", &tm) <= 0)
+                return -EINVAL;
+
+        xsprintf(header_pid, "["PID_FMT"]: ", getpid_cached());
+
+        iovec[0] = IOVEC_MAKE_STRING(header_priority);
+        iovec[1] = IOVEC_MAKE_STRING(header_time);
+        iovec[2] = IOVEC_MAKE_STRING(program_invocation_short_name);
+        iovec[3] = IOVEC_MAKE_STRING(header_pid);
+        iovec[4] = IOVEC_MAKE_STRING(buffer);
+
+        /* When using syslog via SOCK_STREAM separate the messages by NUL chars */
+        if (syslog_is_stream)
+                iovec[4].iov_len++;
+
+        for (;;) {
+                ssize_t n;
+
+                n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL);
+                if (n < 0)
+                        return -errno;
+
+                if (!syslog_is_stream ||
+                    (size_t) n >= IOVEC_TOTAL_SIZE(iovec, ELEMENTSOF(iovec)))
+                        break;
+
+                IOVEC_INCREMENT(iovec, ELEMENTSOF(iovec), n);
+        }
+
+        return 1;
+}
+
+static int write_to_kmsg(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *buffer) {
+
+        char header_priority[2 + DECIMAL_STR_MAX(int) + 1],
+             header_pid[4 + DECIMAL_STR_MAX(pid_t) + 1];
+        struct iovec iovec[5] = {};
+
+        if (kmsg_fd < 0)
+                return 0;
+
+        xsprintf(header_priority, "<%i>", level);
+        xsprintf(header_pid, "["PID_FMT"]: ", getpid_cached());
+
+        iovec[0] = IOVEC_MAKE_STRING(header_priority);
+        iovec[1] = IOVEC_MAKE_STRING(program_invocation_short_name);
+        iovec[2] = IOVEC_MAKE_STRING(header_pid);
+        iovec[3] = IOVEC_MAKE_STRING(buffer);
+        iovec[4] = IOVEC_MAKE_STRING("\n");
+
+        if (writev(kmsg_fd, iovec, ELEMENTSOF(iovec)) < 0)
+                return -errno;
+
+        return 1;
+}
+
+static int log_do_header(
+                char *header,
+                size_t size,
+                int level,
+                int error,
+                const char *file, int line, const char *func,
+                const char *object_field, const char *object,
+                const char *extra_field, const char *extra) {
+        int r;
+
+        error = IS_SYNTHETIC_ERRNO(error) ? 0 : ERRNO_VALUE(error);
+
+        r = snprintf(header, size,
+                     "PRIORITY=%i\n"
+                     "SYSLOG_FACILITY=%i\n"
+                     "%s%.256s%s"        /* CODE_FILE */
+                     "%s%.*i%s"          /* CODE_LINE */
+                     "%s%.256s%s"        /* CODE_FUNC */
+                     "%s%.*i%s"          /* ERRNO */
+                     "%s%.256s%s"        /* object */
+                     "%s%.256s%s"        /* extra */
+                     "SYSLOG_IDENTIFIER=%.256s\n",
+                     LOG_PRI(level),
+                     LOG_FAC(level),
+                     isempty(file) ? "" : "CODE_FILE=",
+                     isempty(file) ? "" : file,
+                     isempty(file) ? "" : "\n",
+                     line ? "CODE_LINE=" : "",
+                     line ? 1 : 0, line, /* %.0d means no output too, special case for 0 */
+                     line ? "\n" : "",
+                     isempty(func) ? "" : "CODE_FUNC=",
+                     isempty(func) ? "" : func,
+                     isempty(func) ? "" : "\n",
+                     error ? "ERRNO=" : "",
+                     error ? 1 : 0, error,
+                     error ? "\n" : "",
+                     isempty(object) ? "" : object_field,
+                     isempty(object) ? "" : object,
+                     isempty(object) ? "" : "\n",
+                     isempty(extra) ? "" : extra_field,
+                     isempty(extra) ? "" : extra,
+                     isempty(extra) ? "" : "\n",
+                     program_invocation_short_name);
+        assert_raw((size_t) r < size);
+
+        return 0;
+}
+
+static int write_to_journal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra_field,
+                const char *extra,
+                const char *buffer) {
+
+        char header[LINE_MAX];
+        struct iovec iovec[4] = {};
+        struct msghdr mh = {};
+
+        if (journal_fd < 0)
+                return 0;
+
+        log_do_header(header, sizeof(header), level, error, file, line, func, object_field, object, extra_field, extra);
+
+        iovec[0] = IOVEC_MAKE_STRING(header);
+        iovec[1] = IOVEC_MAKE_STRING("MESSAGE=");
+        iovec[2] = IOVEC_MAKE_STRING(buffer);
+        iovec[3] = IOVEC_MAKE_STRING("\n");
+
+        mh.msg_iov = iovec;
+        mh.msg_iovlen = ELEMENTSOF(iovec);
+
+        if (sendmsg(journal_fd, &mh, MSG_NOSIGNAL) < 0)
+                return -errno;
+
+        return 1;
+}
+
+int log_dispatch_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra_field,
+                const char *extra,
+                char *buffer) {
+
+        assert_raw(buffer);
+
+        if (log_target == LOG_TARGET_NULL)
+                return -ERRNO_VALUE(error);
+
+        /* Patch in LOG_DAEMON facility if necessary */
+        if ((level & LOG_FACMASK) == 0)
+                level |= log_facility;
+
+        if (open_when_needed)
+                log_open();
+
+        do {
+                char *e;
+                int k = 0;
+
+                buffer += strspn(buffer, NEWLINE);
+
+                if (buffer[0] == 0)
+                        break;
+
+                if ((e = strpbrk(buffer, NEWLINE)))
+                        *(e++) = 0;
+
+                if (IN_SET(log_target, LOG_TARGET_AUTO,
+                                       LOG_TARGET_JOURNAL_OR_KMSG,
+                                       LOG_TARGET_JOURNAL)) {
+
+                        k = write_to_journal(level, error, file, line, func, object_field, object, extra_field, extra, buffer);
+                        if (k < 0 && k != -EAGAIN)
+                                log_close_journal();
+                }
+
+                if (IN_SET(log_target, LOG_TARGET_SYSLOG_OR_KMSG,
+                                       LOG_TARGET_SYSLOG)) {
+
+                        k = write_to_syslog(level, error, file, line, func, buffer);
+                        if (k < 0 && k != -EAGAIN)
+                                log_close_syslog();
+                }
+
+                if (k <= 0 &&
+                    IN_SET(log_target, LOG_TARGET_AUTO,
+                                       LOG_TARGET_SYSLOG_OR_KMSG,
+                                       LOG_TARGET_JOURNAL_OR_KMSG,
+                                       LOG_TARGET_KMSG)) {
+
+                        if (k < 0)
+                                log_open_kmsg();
+
+                        k = write_to_kmsg(level, error, file, line, func, buffer);
+                        if (k < 0) {
+                                log_close_kmsg();
+                                log_open_console();
+                        }
+                }
+
+                if (k <= 0)
+                        (void) write_to_console(level, error, file, line, func, buffer);
+
+                buffer = e;
+        } while (buffer);
+
+        if (open_when_needed)
+                log_close();
+
+        return -ERRNO_VALUE(error);
+}
+
+int log_dump_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                char *buffer) {
+
+        LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
+        PROTECT_ERRNO;
+
+        /* This modifies the buffer... */
+
+        if (_likely_(LOG_PRI(level) > log_max_level[realm]))
+                return -ERRNO_VALUE(error);
+
+        return log_dispatch_internal(level, error, file, line, func, NULL, NULL, NULL, NULL, buffer);
+}
+
+int log_internalv_realm(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format,
+                va_list ap) {
+
+        LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
+        char buffer[LINE_MAX];
+        PROTECT_ERRNO;
+
+        if (_likely_(LOG_PRI(level) > log_max_level[realm]))
+                return -ERRNO_VALUE(error);
+
+        /* Make sure that %m maps to the specified error (or "Success"). */
+        errno = ERRNO_VALUE(error);
+
+        (void) vsnprintf(buffer, sizeof buffer, format, ap);
+
+        return log_dispatch_internal(level, error, file, line, func, NULL, NULL, NULL, NULL, buffer);
+}
+
+int log_internal_realm(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        va_list ap;
+        int r;
+
+        va_start(ap, format);
+        r = log_internalv_realm(level, error, file, line, func, format, ap);
+        va_end(ap);
+
+        return r;
+}
+
+_printf_(10,0)
+static int log_object_internalv(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra_field,
+                const char *extra,
+                const char *format,
+                va_list ap) {
+
+        PROTECT_ERRNO;
+        char *buffer, *b;
+
+        if (_likely_(LOG_PRI(level) > log_max_level[LOG_REALM_SYSTEMD]))
+                return -ERRNO_VALUE(error);
+
+        /* Make sure that %m maps to the specified error (or "Success"). */
+        errno = ERRNO_VALUE(error);
+
+        /* Prepend the object name before the message */
+        if (object) {
+                size_t n;
+
+                n = strlen(object);
+                buffer = newa(char, n + 2 + LINE_MAX);
+                b = stpcpy(stpcpy(buffer, object), ": ");
+        } else
+                b = buffer = newa(char, LINE_MAX);
+
+        (void) vsnprintf(b, LINE_MAX, format, ap);
+
+        return log_dispatch_internal(level, error, file, line, func,
+                                     object_field, object, extra_field, extra, buffer);
+}
+
+int log_object_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra_field,
+                const char *extra,
+                const char *format, ...) {
+
+        va_list ap;
+        int r;
+
+        va_start(ap, format);
+        r = log_object_internalv(level, error, file, line, func, object_field, object, extra_field, extra, format, ap);
+        va_end(ap);
+
+        return r;
+}
+
+static void log_assert(
+                int level,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format) {
+
+        static char buffer[LINE_MAX];
+        LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
+
+        if (_likely_(LOG_PRI(level) > log_max_level[realm]))
+                return;
+
+        DISABLE_WARNING_FORMAT_NONLITERAL;
+        (void) snprintf(buffer, sizeof buffer, format, text, file, line, func);
+        REENABLE_WARNING;
+
+        log_abort_msg = buffer;
+
+        log_dispatch_internal(level, 0, file, line, func, NULL, NULL, NULL, NULL, buffer);
+}
+
+_noreturn_ void log_assert_failed_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func) {
+        log_open();
+        log_assert(LOG_REALM_PLUS_LEVEL(realm, LOG_CRIT), text, file, line, func,
+                   "Assertion '%s' failed at %s:%u, function %s(). Aborting.");
+        abort();
+}
+
+_noreturn_ void log_assert_failed_unreachable_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func) {
+        log_open();
+        log_assert(LOG_REALM_PLUS_LEVEL(realm, LOG_CRIT), text, file, line, func,
+                   "Code should not be reached '%s' at %s:%u, function %s(). Aborting.");
+        abort();
+}
+
+void log_assert_failed_return_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func) {
+        PROTECT_ERRNO;
+        log_assert(LOG_REALM_PLUS_LEVEL(realm, LOG_DEBUG), text, file, line, func,
+                   "Assertion '%s' failed at %s:%u, function %s(). Ignoring.");
+}
+
+int log_oom_internal(LogRealm realm, const char *file, int line, const char *func) {
+        return log_internal_realm(LOG_REALM_PLUS_LEVEL(realm, LOG_ERR),
+                                  ENOMEM, file, line, func, "Out of memory.");
+}
+
+int log_format_iovec(
+                struct iovec *iovec,
+                size_t iovec_len,
+                size_t *n,
+                bool newline_separator,
+                int error,
+                const char *format,
+                va_list ap) {
+
+        static const char nl = '\n';
+
+        while (format && *n + 1 < iovec_len) {
+                va_list aq;
+                char *m;
+                int r;
+
+                /* We need to copy the va_list structure,
+                 * since vasprintf() leaves it afterwards at
+                 * an undefined location */
+
+                errno = ERRNO_VALUE(error);
+
+                va_copy(aq, ap);
+                r = vasprintf(&m, format, aq);
+                va_end(aq);
+                if (r < 0)
+                        return -EINVAL;
+
+                /* Now, jump enough ahead, so that we point to
+                 * the next format string */
+                VA_FORMAT_ADVANCE(format, ap);
+
+                iovec[(*n)++] = IOVEC_MAKE_STRING(m);
+
+                if (newline_separator) {
+                        iovec[*n] = IOVEC_MAKE((char *)&nl, 1);
+                        (*n)++;
+                }
+
+                format = va_arg(ap, char *);
+        }
+        return 0;
+}
+
+int log_struct_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
+        char buf[LINE_MAX];
+        bool found = false;
+        PROTECT_ERRNO;
+        va_list ap;
+
+        if (_likely_(LOG_PRI(level) > log_max_level[realm]) ||
+            log_target == LOG_TARGET_NULL)
+                return -ERRNO_VALUE(error);
+
+        if ((level & LOG_FACMASK) == 0)
+                level |= log_facility;
+
+        if (IN_SET(log_target,
+                   LOG_TARGET_AUTO,
+                   LOG_TARGET_JOURNAL_OR_KMSG,
+                   LOG_TARGET_JOURNAL)) {
+
+                if (open_when_needed)
+                        log_open_journal();
+
+                if (journal_fd >= 0) {
+                        char header[LINE_MAX];
+                        struct iovec iovec[17] = {};
+                        size_t n = 0, i;
+                        int r;
+                        struct msghdr mh = {
+                                .msg_iov = iovec,
+                        };
+                        bool fallback = false;
+
+                        /* If the journal is available do structured logging.
+                         * Do not report the errno if it is synthetic. */
+                        log_do_header(header, sizeof(header), level, error, file, line, func, NULL, NULL, NULL, NULL);
+                        iovec[n++] = IOVEC_MAKE_STRING(header);
+
+                        va_start(ap, format);
+                        r = log_format_iovec(iovec, ELEMENTSOF(iovec), &n, true, error, format, ap);
+                        if (r < 0)
+                                fallback = true;
+                        else {
+                                mh.msg_iovlen = n;
+                                (void) sendmsg(journal_fd, &mh, MSG_NOSIGNAL);
+                        }
+
+                        va_end(ap);
+                        for (i = 1; i < n; i += 2)
+                                free(iovec[i].iov_base);
+
+                        if (!fallback) {
+                                if (open_when_needed)
+                                        log_close();
+
+                                return -ERRNO_VALUE(error);
+                        }
+                }
+        }
+
+        /* Fallback if journal logging is not available or didn't work. */
+
+        va_start(ap, format);
+        while (format) {
+                va_list aq;
+
+                errno = ERRNO_VALUE(error);
+
+                va_copy(aq, ap);
+                (void) vsnprintf(buf, sizeof buf, format, aq);
+                va_end(aq);
+
+                if (startswith(buf, "MESSAGE=")) {
+                        found = true;
+                        break;
+                }
+
+                VA_FORMAT_ADVANCE(format, ap);
+
+                format = va_arg(ap, char *);
+        }
+        va_end(ap);
+
+        if (!found) {
+                if (open_when_needed)
+                        log_close();
+
+                return -ERRNO_VALUE(error);
+        }
+
+        return log_dispatch_internal(level, error, file, line, func, NULL, NULL, NULL, NULL, buf + 8);
+}
+
+int log_struct_iovec_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const struct iovec input_iovec[],
+                size_t n_input_iovec) {
+
+        LogRealm realm = LOG_REALM_REMOVE_LEVEL(level);
+        PROTECT_ERRNO;
+        size_t i;
+        char *m;
+
+        if (_likely_(LOG_PRI(level) > log_max_level[realm]) ||
+            log_target == LOG_TARGET_NULL)
+                return -ERRNO_VALUE(error);
+
+        if ((level & LOG_FACMASK) == 0)
+                level |= log_facility;
+
+        if (IN_SET(log_target, LOG_TARGET_AUTO,
+                               LOG_TARGET_JOURNAL_OR_KMSG,
+                               LOG_TARGET_JOURNAL) &&
+            journal_fd >= 0) {
+
+                struct iovec iovec[1 + n_input_iovec*2];
+                char header[LINE_MAX];
+                struct msghdr mh = {
+                        .msg_iov = iovec,
+                        .msg_iovlen = 1 + n_input_iovec*2,
+                };
+
+                log_do_header(header, sizeof(header), level, error, file, line, func, NULL, NULL, NULL, NULL);
+                iovec[0] = IOVEC_MAKE_STRING(header);
+
+                for (i = 0; i < n_input_iovec; i++) {
+                        iovec[1+i*2] = input_iovec[i];
+                        iovec[1+i*2+1] = IOVEC_MAKE_STRING("\n");
+                }
+
+                if (sendmsg(journal_fd, &mh, MSG_NOSIGNAL) >= 0)
+                        return -ERRNO_VALUE(error);
+        }
+
+        for (i = 0; i < n_input_iovec; i++)
+                if (memory_startswith(input_iovec[i].iov_base, input_iovec[i].iov_len, "MESSAGE="))
+                        break;
+
+        if (_unlikely_(i >= n_input_iovec)) /* Couldn't find MESSAGE=? */
+                return -ERRNO_VALUE(error);
+
+        m = strndupa(input_iovec[i].iov_base + STRLEN("MESSAGE="),
+                     input_iovec[i].iov_len - STRLEN("MESSAGE="));
+
+        return log_dispatch_internal(level, error, file, line, func, NULL, NULL, NULL, NULL, m);
+}
+
+int log_set_target_from_string(const char *e) {
+        LogTarget t;
+
+        t = log_target_from_string(e);
+        if (t < 0)
+                return -EINVAL;
+
+        log_set_target(t);
+        return 0;
+}
+
+int log_set_max_level_from_string_realm(LogRealm realm, const char *e) {
+        int t;
+
+        t = log_level_from_string(e);
+        if (t < 0)
+                return -EINVAL;
+
+        log_set_max_level_realm(realm, t);
+        return 0;
+}
+
+static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
+
+        /*
+         * The systemd.log_xyz= settings are parsed by all tools, and
+         * so is "debug".
+         *
+         * However, "quiet" is only parsed by PID 1, and only turns of
+         * status output to /dev/console, but does not alter the log
+         * level.
+         */
+
+        if (streq(key, "debug") && !value)
+                log_set_max_level(LOG_DEBUG);
+
+        else if (proc_cmdline_key_streq(key, "systemd.log_target")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                if (log_set_target_from_string(value) < 0)
+                        log_warning("Failed to parse log target '%s'. Ignoring.", value);
+
+        } else if (proc_cmdline_key_streq(key, "systemd.log_level")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                if (log_set_max_level_from_string(value) < 0)
+                        log_warning("Failed to parse log level '%s'. Ignoring.", value);
+
+        } else if (proc_cmdline_key_streq(key, "systemd.log_color")) {
+
+                if (log_show_color_from_string(value ?: "1") < 0)
+                        log_warning("Failed to parse log color setting '%s'. Ignoring.", value);
+
+        } else if (proc_cmdline_key_streq(key, "systemd.log_location")) {
+
+                if (log_show_location_from_string(value ?: "1") < 0)
+                        log_warning("Failed to parse log location setting '%s'. Ignoring.", value);
+        }
+
+        return 0;
+}
+
+void log_parse_environment_realm(LogRealm realm) {
+        /* Do not call from library code. */
+
+        const char *e;
+
+        if (get_ctty_devnr(0, NULL) < 0)
+                /* Only try to read the command line in daemons.  We assume that anything that has a controlling tty is
+                   user stuff. */
+                (void) proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
+
+        e = getenv("SYSTEMD_LOG_TARGET");
+        if (e && log_set_target_from_string(e) < 0)
+                log_warning("Failed to parse log target '%s'. Ignoring.", e);
+
+        e = getenv("SYSTEMD_LOG_LEVEL");
+        if (e && log_set_max_level_from_string_realm(realm, e) < 0)
+                log_warning("Failed to parse log level '%s'. Ignoring.", e);
+
+        e = getenv("SYSTEMD_LOG_COLOR");
+        if (e && log_show_color_from_string(e) < 0)
+                log_warning("Failed to parse bool '%s'. Ignoring.", e);
+
+        e = getenv("SYSTEMD_LOG_LOCATION");
+        if (e && log_show_location_from_string(e) < 0)
+                log_warning("Failed to parse bool '%s'. Ignoring.", e);
+}
+
+LogTarget log_get_target(void) {
+        return log_target;
+}
+
+int log_get_max_level_realm(LogRealm realm) {
+        return log_max_level[realm];
+}
+
+void log_show_color(bool b) {
+        show_color = b;
+}
+
+bool log_get_show_color(void) {
+        return show_color;
+}
+
+void log_show_location(bool b) {
+        show_location = b;
+}
+
+bool log_get_show_location(void) {
+        return show_location;
+}
+
+int log_show_color_from_string(const char *e) {
+        int t;
+
+        t = parse_boolean(e);
+        if (t < 0)
+                return t;
+
+        log_show_color(t);
+        return 0;
+}
+
+int log_show_location_from_string(const char *e) {
+        int t;
+
+        t = parse_boolean(e);
+        if (t < 0)
+                return t;
+
+        log_show_location(t);
+        return 0;
+}
+
+bool log_on_console(void) {
+        if (IN_SET(log_target, LOG_TARGET_CONSOLE,
+                               LOG_TARGET_CONSOLE_PREFIXED))
+                return true;
+
+        return syslog_fd < 0 && kmsg_fd < 0 && journal_fd < 0;
+}
+
+static const char *const log_target_table[_LOG_TARGET_MAX] = {
+        [LOG_TARGET_CONSOLE] = "console",
+        [LOG_TARGET_CONSOLE_PREFIXED] = "console-prefixed",
+        [LOG_TARGET_KMSG] = "kmsg",
+        [LOG_TARGET_JOURNAL] = "journal",
+        [LOG_TARGET_JOURNAL_OR_KMSG] = "journal-or-kmsg",
+        [LOG_TARGET_SYSLOG] = "syslog",
+        [LOG_TARGET_SYSLOG_OR_KMSG] = "syslog-or-kmsg",
+        [LOG_TARGET_AUTO] = "auto",
+        [LOG_TARGET_NULL] = "null",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(log_target, LogTarget);
+
+void log_received_signal(int level, const struct signalfd_siginfo *si) {
+        assert(si);
+
+        if (pid_is_valid(si->ssi_pid)) {
+                _cleanup_free_ char *p = NULL;
+
+                (void) get_process_comm(si->ssi_pid, &p);
+
+                log_full(level,
+                         "Received SIG%s from PID %"PRIu32" (%s).",
+                         signal_to_string(si->ssi_signo),
+                         si->ssi_pid, strna(p));
+        } else
+                log_full(level,
+                         "Received SIG%s.",
+                         signal_to_string(si->ssi_signo));
+}
+
+int log_syntax_internal(
+                const char *unit,
+                int level,
+                const char *config_file,
+                unsigned config_line,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        PROTECT_ERRNO;
+        char buffer[LINE_MAX];
+        va_list ap;
+        const char *unit_fmt = NULL;
+
+        if (_likely_(LOG_PRI(level) > log_max_level[LOG_REALM_SYSTEMD]) ||
+            log_target == LOG_TARGET_NULL)
+                return -ERRNO_VALUE(error);
+
+        errno = error;
+
+        va_start(ap, format);
+        (void) vsnprintf(buffer, sizeof buffer, format, ap);
+        va_end(ap);
+
+        if (unit)
+                unit_fmt = getpid_cached() == 1 ? "UNIT=%s" : "USER_UNIT=%s";
+
+        return log_struct_internal(
+                        LOG_REALM_PLUS_LEVEL(LOG_REALM_SYSTEMD, level),
+                        error,
+                        file, line, func,
+                        "MESSAGE_ID=" SD_MESSAGE_INVALID_CONFIGURATION_STR,
+                        "CONFIG_FILE=%s", config_file,
+                        "CONFIG_LINE=%u", config_line,
+                        LOG_MESSAGE("%s:%u: %s", config_file, config_line, buffer),
+                        unit_fmt, unit,
+                        NULL);
+}
+
+int log_syntax_invalid_utf8_internal(
+                const char *unit,
+                int level,
+                const char *config_file,
+                unsigned config_line,
+                const char *file,
+                int line,
+                const char *func,
+                const char *rvalue) {
+
+        _cleanup_free_ char *p = NULL;
+
+        if (rvalue)
+                p = utf8_escape_invalid(rvalue);
+
+        log_syntax_internal(unit, level, config_file, config_line, 0, file, line, func,
+                            "String is not UTF-8 clean, ignoring assignment: %s", strna(p));
+
+        return -EINVAL;
+}
+
+void log_set_upgrade_syslog_to_journal(bool b) {
+        upgrade_syslog_to_journal = b;
+
+        /* Make the change effective immediately */
+        if (b) {
+                if (log_target == LOG_TARGET_SYSLOG)
+                        log_target = LOG_TARGET_JOURNAL;
+                else if (log_target == LOG_TARGET_SYSLOG_OR_KMSG)
+                        log_target = LOG_TARGET_JOURNAL_OR_KMSG;
+        }
+}
+
+void log_set_always_reopen_console(bool b) {
+        always_reopen_console = b;
+}
+
+void log_set_open_when_needed(bool b) {
+        open_when_needed = b;
+}
+
+void log_set_prohibit_ipc(bool b) {
+        prohibit_ipc = b;
+}
+
+int log_emergency_level(void) {
+        /* Returns the log level to use for log_emergency() logging. We use LOG_EMERG only when we are PID 1, as only
+         * then the system of the whole system is obviously affected. */
+
+        return getpid_cached() == 1 ? LOG_EMERG : LOG_ERR;
+}
+
+int log_dup_console(void) {
+        int copy;
+
+        /* Duplicate the fd we use for fd logging if it's < 3 and use the copy from now on. This call is useful
+         * whenever we want to continue logging through the original fd, but want to rearrange stderr. */
+
+        if (console_fd >= 3)
+                return 0;
+
+        copy = fcntl(console_fd, F_DUPFD_CLOEXEC, 3);
+        if (copy < 0)
+                return -errno;
+
+        console_fd = copy;
+        return 0;
+}
+
+void log_setup_service(void) {
+        /* Sets up logging the way it is most appropriate for running a program as a service. Note that using this
+         * doesn't make the binary unsuitable for invocation on the command line, as log output will still go to the
+         * terminal if invoked interactively. */
+
+        log_set_target(LOG_TARGET_AUTO);
+        log_parse_environment();
+        log_open();
+}
diff --git a/src/basic/log.h b/src/basic/log.h
new file mode 100644
index 0000000..17438d7
--- /dev/null
+++ b/src/basic/log.h
@@ -0,0 +1,324 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <syslog.h>
+
+#include "macro.h"
+
+/* Some structures we reference but don't want to pull in headers for */
+struct iovec;
+struct signalfd_siginfo;
+
+typedef enum LogRealm {
+        LOG_REALM_SYSTEMD,
+        LOG_REALM_UDEV,
+        _LOG_REALM_MAX,
+} LogRealm;
+
+#ifndef LOG_REALM
+#  define LOG_REALM LOG_REALM_SYSTEMD
+#endif
+
+typedef enum LogTarget{
+        LOG_TARGET_CONSOLE,
+        LOG_TARGET_CONSOLE_PREFIXED,
+        LOG_TARGET_KMSG,
+        LOG_TARGET_JOURNAL,
+        LOG_TARGET_JOURNAL_OR_KMSG,
+        LOG_TARGET_SYSLOG,
+        LOG_TARGET_SYSLOG_OR_KMSG,
+        LOG_TARGET_AUTO, /* console if stderr is tty, JOURNAL_OR_KMSG otherwise */
+        LOG_TARGET_NULL,
+        _LOG_TARGET_MAX,
+        _LOG_TARGET_INVALID = -1
+} LogTarget;
+
+/* Note to readers: << and >> have lower precedence than & and | */
+#define LOG_REALM_PLUS_LEVEL(realm, level)  ((realm) << 10 | (level))
+#define LOG_REALM_REMOVE_LEVEL(realm_level) ((realm_level) >> 10)
+#define SYNTHETIC_ERRNO(num)                (1 << 30 | (num))
+#define IS_SYNTHETIC_ERRNO(val)             ((val) >> 30 & 1)
+#define ERRNO_VALUE(val)                    (abs(val) & 255)
+
+void log_set_target(LogTarget target);
+void log_set_max_level_realm(LogRealm realm, int level);
+#define log_set_max_level(level)                \
+        log_set_max_level_realm(LOG_REALM, (level))
+
+void log_set_facility(int facility);
+
+int log_set_target_from_string(const char *e);
+int log_set_max_level_from_string_realm(LogRealm realm, const char *e);
+#define log_set_max_level_from_string(e)        \
+        log_set_max_level_from_string_realm(LOG_REALM, (e))
+
+void log_show_color(bool b);
+bool log_get_show_color(void) _pure_;
+void log_show_location(bool b);
+bool log_get_show_location(void) _pure_;
+
+int log_show_color_from_string(const char *e);
+int log_show_location_from_string(const char *e);
+
+LogTarget log_get_target(void) _pure_;
+int log_get_max_level_realm(LogRealm realm) _pure_;
+#define log_get_max_level()                     \
+        log_get_max_level_realm(LOG_REALM)
+
+/* Functions below that open and close logs or configure logging based on the
+ * environment should not be called from library code — this is always a job
+ * for the application itself.
+ */
+
+int log_open(void);
+void log_close(void);
+void log_forget_fds(void);
+
+void log_parse_environment_realm(LogRealm realm);
+#define log_parse_environment() \
+        log_parse_environment_realm(LOG_REALM)
+
+int log_dispatch_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra,
+                const char *extra_field,
+                char *buffer);
+
+int log_internal_realm(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) _printf_(6,7);
+#define log_internal(level, ...) \
+        log_internal_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
+
+int log_internalv_realm(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format,
+                va_list ap) _printf_(6,0);
+#define log_internalv(level, ...) \
+        log_internalv_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
+
+/* Realm is fixed to LOG_REALM_SYSTEMD for those */
+int log_object_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra_field,
+                const char *extra,
+                const char *format, ...) _printf_(10,11);
+
+int log_struct_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) _printf_(6,0) _sentinel_;
+
+int log_oom_internal(
+                LogRealm realm,
+                const char *file,
+                int line,
+                const char *func);
+
+int log_format_iovec(
+                struct iovec *iovec,
+                size_t iovec_len,
+                size_t *n,
+                bool newline_separator,
+                int error,
+                const char *format,
+                va_list ap) _printf_(6, 0);
+
+int log_struct_iovec_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const struct iovec *input_iovec,
+                size_t n_input_iovec);
+
+/* This modifies the buffer passed! */
+int log_dump_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                char *buffer);
+
+/* Logging for various assertions */
+_noreturn_ void log_assert_failed_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func);
+#define log_assert_failed(text, ...) \
+        log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__)
+
+_noreturn_ void log_assert_failed_unreachable_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func);
+#define log_assert_failed_unreachable(text, ...) \
+        log_assert_failed_unreachable_realm(LOG_REALM, (text), __VA_ARGS__)
+
+void log_assert_failed_return_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func);
+#define log_assert_failed_return(text, ...) \
+        log_assert_failed_return_realm(LOG_REALM, (text), __VA_ARGS__)
+
+#define log_dispatch(level, error, buffer)                              \
+        log_dispatch_internal(level, error, __FILE__, __LINE__, __func__, NULL, NULL, NULL, NULL, buffer)
+
+/* Logging with level */
+#define log_full_errno_realm(realm, level, error, ...)                  \
+        ({                                                              \
+                int _level = (level), _e = (error), _realm = (realm);   \
+                (log_get_max_level_realm(_realm) >= LOG_PRI(_level))    \
+                        ? log_internal_realm(LOG_REALM_PLUS_LEVEL(_realm, _level), _e, \
+                                             __FILE__, __LINE__, __func__, __VA_ARGS__) \
+                        : -ERRNO_VALUE(_e);                             \
+        })
+
+#define log_full_errno(level, error, ...)                               \
+        log_full_errno_realm(LOG_REALM, (level), (error), __VA_ARGS__)
+
+#define log_full(level, ...) log_full_errno((level), 0, __VA_ARGS__)
+
+int log_emergency_level(void);
+
+/* Normal logging */
+#define log_debug(...)     log_full(LOG_DEBUG,   __VA_ARGS__)
+#define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
+#define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
+#define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
+#define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
+#define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
+
+/* Logging triggered by an errno-like error */
+#define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
+#define log_info_errno(error, ...)      log_full_errno(LOG_INFO,    error, __VA_ARGS__)
+#define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
+#define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
+#define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
+#define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
+
+#ifdef LOG_TRACE
+#  define log_trace(...) log_debug(__VA_ARGS__)
+#else
+#  define log_trace(...) do {} while (0)
+#endif
+
+/* Structured logging */
+#define log_struct_errno(level, error, ...) \
+        log_struct_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
+                            error, __FILE__, __LINE__, __func__, __VA_ARGS__, NULL)
+#define log_struct(level, ...) log_struct_errno(level, 0, __VA_ARGS__)
+
+#define log_struct_iovec_errno(level, error, iovec, n_iovec)            \
+        log_struct_iovec_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
+                                  error, __FILE__, __LINE__, __func__, iovec, n_iovec)
+#define log_struct_iovec(level, iovec, n_iovec) log_struct_iovec_errno(level, 0, iovec, n_iovec)
+
+/* This modifies the buffer passed! */
+#define log_dump(level, buffer) \
+        log_dump_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
+                          0, __FILE__, __LINE__, __func__, buffer)
+
+#define log_oom() log_oom_internal(LOG_REALM, __FILE__, __LINE__, __func__)
+
+bool log_on_console(void) _pure_;
+
+const char *log_target_to_string(LogTarget target) _const_;
+LogTarget log_target_from_string(const char *s) _pure_;
+
+/* Helper to prepare various field for structured logging */
+#define LOG_MESSAGE(fmt, ...) "MESSAGE=" fmt, ##__VA_ARGS__
+
+void log_received_signal(int level, const struct signalfd_siginfo *si);
+
+/* If turned on, any requests for a log target involving "syslog" will be implicitly upgraded to the equivalent journal target */
+void log_set_upgrade_syslog_to_journal(bool b);
+
+/* If turned on, and log_open() is called, we'll not use STDERR_FILENO for logging ever, but rather open /dev/console */
+void log_set_always_reopen_console(bool b);
+
+/* If turned on, we'll open the log stream implicitly if needed on each individual log call. This is normally not
+ * desired as we want to reuse our logging streams. It is useful however  */
+void log_set_open_when_needed(bool b);
+
+/* If turned on, then we'll never use IPC-based logging, i.e. never log to syslog or the journal. We'll only log to
+ * stderr, the console or kmsg */
+void log_set_prohibit_ipc(bool b);
+
+int log_dup_console(void);
+
+int log_syntax_internal(
+                const char *unit,
+                int level,
+                const char *config_file,
+                unsigned config_line,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) _printf_(9, 10);
+
+int log_syntax_invalid_utf8_internal(
+                const char *unit,
+                int level,
+                const char *config_file,
+                unsigned config_line,
+                const char *file,
+                int line,
+                const char *func,
+                const char *rvalue);
+
+#define log_syntax(unit, level, config_file, config_line, error, ...)   \
+        ({                                                              \
+                int _level = (level), _e = (error);                     \
+                (log_get_max_level() >= LOG_PRI(_level))                \
+                        ? log_syntax_internal(unit, _level, config_file, config_line, _e, __FILE__, __LINE__, __func__, __VA_ARGS__) \
+                        : -abs(_e);                                     \
+        })
+
+#define log_syntax_invalid_utf8(unit, level, config_file, config_line, rvalue) \
+        ({                                                              \
+                int _level = (level);                                   \
+                (log_get_max_level() >= LOG_PRI(_level))                \
+                        ? log_syntax_invalid_utf8_internal(unit, _level, config_file, config_line, __FILE__, __LINE__, __func__, rvalue) \
+                        : -EINVAL;                                      \
+        })
+
+#define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)
+
+void log_setup_service(void);
diff --git a/src/basic/login-util.c b/src/basic/login-util.c
new file mode 100644
index 0000000..085ccd0
--- /dev/null
+++ b/src/basic/login-util.c
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <string.h>
+
+#include "login-util.h"
+#include "string-util.h"
+
+bool session_id_valid(const char *id) {
+
+        if (isempty(id))
+                return false;
+
+        return id[strspn(id, LETTERS DIGITS)] == '\0';
+}
diff --git a/src/basic/login-util.h b/src/basic/login-util.h
new file mode 100644
index 0000000..e1e62e1
--- /dev/null
+++ b/src/basic/login-util.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <unistd.h>
+
+bool session_id_valid(const char *id);
+
+static inline bool logind_running(void) {
+        return access("/run/systemd/seats/", F_OK) >= 0;
+}
diff --git a/src/basic/macro.h b/src/basic/macro.h
new file mode 100644
index 0000000..1971e91
--- /dev/null
+++ b/src/basic/macro.h
@@ -0,0 +1,549 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <sys/param.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+
+#define _printf_(a, b) __attribute__((__format__(printf, a, b)))
+#ifdef __clang__
+#  define _alloc_(...)
+#else
+#  define _alloc_(...) __attribute__((__alloc_size__(__VA_ARGS__)))
+#endif
+#define _sentinel_ __attribute__((__sentinel__))
+#define _section_(x) __attribute__((__section__(x)))
+#define _used_ __attribute__((__used__))
+#define _unused_ __attribute__((__unused__))
+#define _destructor_ __attribute__((__destructor__))
+#define _pure_ __attribute__((__pure__))
+#define _const_ __attribute__((__const__))
+#define _deprecated_ __attribute__((__deprecated__))
+#define _packed_ __attribute__((__packed__))
+#define _malloc_ __attribute__((__malloc__))
+#define _weak_ __attribute__((__weak__))
+#define _likely_(x) (__builtin_expect(!!(x), 1))
+#define _unlikely_(x) (__builtin_expect(!!(x), 0))
+#define _public_ __attribute__((__visibility__("default")))
+#define _hidden_ __attribute__((__visibility__("hidden")))
+#define _weakref_(x) __attribute__((__weakref__(#x)))
+#define _align_(x) __attribute__((__aligned__(x)))
+#define _alignas_(x) __attribute__((__aligned__(__alignof(x))))
+#define _alignptr_ __attribute__((__aligned__(sizeof(void*))))
+#define _cleanup_(x) __attribute__((__cleanup__(x)))
+#if __GNUC__ >= 7
+#define _fallthrough_ __attribute__((__fallthrough__))
+#else
+#define _fallthrough_
+#endif
+/* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
+ * compiler versions */
+#ifndef _noreturn_
+#if __STDC_VERSION__ >= 201112L
+#define _noreturn_ _Noreturn
+#else
+#define _noreturn_ __attribute__((__noreturn__))
+#endif
+#endif
+
+#if !defined(HAS_FEATURE_MEMORY_SANITIZER)
+#  if defined(__has_feature)
+#    if __has_feature(memory_sanitizer)
+#      define HAS_FEATURE_MEMORY_SANITIZER 1
+#    endif
+#  endif
+#  if !defined(HAS_FEATURE_MEMORY_SANITIZER)
+#    define HAS_FEATURE_MEMORY_SANITIZER 0
+#  endif
+#endif
+
+#if !defined(HAS_FEATURE_ADDRESS_SANITIZER)
+#  ifdef __SANITIZE_ADDRESS__
+#      define HAS_FEATURE_ADDRESS_SANITIZER 1
+#  elif defined(__has_feature)
+#    if __has_feature(address_sanitizer)
+#      define HAS_FEATURE_ADDRESS_SANITIZER 1
+#    endif
+#  endif
+#  if !defined(HAS_FEATURE_ADDRESS_SANITIZER)
+#    define HAS_FEATURE_ADDRESS_SANITIZER 0
+#  endif
+#endif
+
+/* Note: on GCC "no_sanitize_address" is a function attribute only, on llvm it may also be applied to global
+ * variables. We define a specific macro which knows this. Note that on GCC we don't need this decorator so much, since
+ * our primary usecase for this attribute is registration structures placed in named ELF sections which shall not be
+ * padded, but GCC doesn't pad those anyway if AddressSanitizer is enabled. */
+#if HAS_FEATURE_ADDRESS_SANITIZER && defined(__clang__)
+#define _variable_no_sanitize_address_ __attribute__((__no_sanitize_address__))
+#else
+#define _variable_no_sanitize_address_
+#endif
+
+/* Temporarily disable some warnings */
+#define DISABLE_WARNING_FORMAT_NONLITERAL                               \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
+
+#define DISABLE_WARNING_MISSING_PROTOTYPES                              \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wmissing-prototypes\"")
+
+#define DISABLE_WARNING_NONNULL                                         \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wnonnull\"")
+
+#define DISABLE_WARNING_SHADOW                                          \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wshadow\"")
+
+#define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES                      \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
+
+#define REENABLE_WARNING                                                \
+        _Pragma("GCC diagnostic pop")
+
+/* automake test harness */
+#define EXIT_TEST_SKIP 77
+
+#define XSTRINGIFY(x) #x
+#define STRINGIFY(x) XSTRINGIFY(x)
+
+#define XCONCATENATE(x, y) x ## y
+#define CONCATENATE(x, y) XCONCATENATE(x, y)
+
+#define UNIQ_T(x, uniq) CONCATENATE(__unique_prefix_, CONCATENATE(x, uniq))
+#define UNIQ __COUNTER__
+
+/* builtins */
+#if __SIZEOF_INT__ == 4
+#define BUILTIN_FFS_U32(x) __builtin_ffs(x);
+#elif __SIZEOF_LONG__ == 4
+#define BUILTIN_FFS_U32(x) __builtin_ffsl(x);
+#else
+#error "neither int nor long are four bytes long?!?"
+#endif
+
+/* Rounds up */
+
+#define ALIGN4(l) (((l) + 3) & ~3)
+#define ALIGN8(l) (((l) + 7) & ~7)
+
+#if __SIZEOF_POINTER__ == 8
+#define ALIGN(l) ALIGN8(l)
+#elif __SIZEOF_POINTER__ == 4
+#define ALIGN(l) ALIGN4(l)
+#else
+#error "Wut? Pointers are neither 4 nor 8 bytes long?"
+#endif
+
+#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) (p)))
+#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) (p)))
+#define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) (p)))
+
+static inline size_t ALIGN_TO(size_t l, size_t ali) {
+        return ((l + ali - 1) & ~(ali - 1));
+}
+
+#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) (p), (ali)))
+
+/* align to next higher power-of-2 (except for: 0 => 0, overflow => 0) */
+static inline unsigned long ALIGN_POWER2(unsigned long u) {
+        /* clz(0) is undefined */
+        if (u == 1)
+                return 1;
+
+        /* left-shift overflow is undefined */
+        if (__builtin_clzl(u - 1UL) < 1)
+                return 0;
+
+        return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
+}
+
+#ifndef __COVERITY__
+#  define VOID_0 ((void)0)
+#else
+#  define VOID_0 ((void*)0)
+#endif
+
+#define ELEMENTSOF(x)                                                   \
+        (__builtin_choose_expr(                                         \
+                !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
+                sizeof(x)/sizeof((x)[0]),                               \
+                VOID_0))
+
+/*
+ * STRLEN - return the length of a string literal, minus the trailing NUL byte.
+ *          Contrary to strlen(), this is a constant expression.
+ * @x: a string literal.
+ */
+#define STRLEN(x) (sizeof(""x"") - 1)
+
+/*
+ * container_of - cast a member of a structure out to the containing structure
+ * @ptr: the pointer to the member.
+ * @type: the type of the container struct this is embedded in.
+ * @member: the name of the member within the struct.
+ */
+#define container_of(ptr, type, member) __container_of(UNIQ, (ptr), type, member)
+#define __container_of(uniq, ptr, type, member)                         \
+        ({                                                              \
+                const typeof( ((type*)0)->member ) *UNIQ_T(A, uniq) = (ptr); \
+                (type*)( (char *)UNIQ_T(A, uniq) - offsetof(type, member) ); \
+        })
+
+#undef MAX
+#define MAX(a, b) __MAX(UNIQ, (a), UNIQ, (b))
+#define __MAX(aq, a, bq, b)                             \
+        ({                                              \
+                const typeof(a) UNIQ_T(A, aq) = (a);    \
+                const typeof(b) UNIQ_T(B, bq) = (b);    \
+                UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
+        })
+
+/* evaluates to (void) if _A or _B are not constant or of different types */
+#define CONST_MAX(_A, _B) \
+        (__builtin_choose_expr(                                         \
+                __builtin_constant_p(_A) &&                             \
+                __builtin_constant_p(_B) &&                             \
+                __builtin_types_compatible_p(typeof(_A), typeof(_B)),   \
+                ((_A) > (_B)) ? (_A) : (_B),                            \
+                VOID_0))
+
+/* takes two types and returns the size of the larger one */
+#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; }))
+
+#define MAX3(x, y, z)                                   \
+        ({                                              \
+                const typeof(x) _c = MAX(x, y);         \
+                MAX(_c, z);                             \
+        })
+
+#undef MIN
+#define MIN(a, b) __MIN(UNIQ, (a), UNIQ, (b))
+#define __MIN(aq, a, bq, b)                             \
+        ({                                              \
+                const typeof(a) UNIQ_T(A, aq) = (a);    \
+                const typeof(b) UNIQ_T(B, bq) = (b);    \
+                UNIQ_T(A, aq) < UNIQ_T(B, bq) ? UNIQ_T(A, aq) : UNIQ_T(B, bq); \
+        })
+
+#define MIN3(x, y, z)                                   \
+        ({                                              \
+                const typeof(x) _c = MIN(x, y);         \
+                MIN(_c, z);                             \
+        })
+
+#define LESS_BY(a, b) __LESS_BY(UNIQ, (a), UNIQ, (b))
+#define __LESS_BY(aq, a, bq, b)                         \
+        ({                                              \
+                const typeof(a) UNIQ_T(A, aq) = (a);    \
+                const typeof(b) UNIQ_T(B, bq) = (b);    \
+                UNIQ_T(A, aq) > UNIQ_T(B, bq) ? UNIQ_T(A, aq) - UNIQ_T(B, bq) : 0; \
+        })
+
+#define CMP(a, b) __CMP(UNIQ, (a), UNIQ, (b))
+#define __CMP(aq, a, bq, b)                             \
+        ({                                              \
+                const typeof(a) UNIQ_T(A, aq) = (a);    \
+                const typeof(b) UNIQ_T(B, bq) = (b);    \
+                UNIQ_T(A, aq) < UNIQ_T(B, bq) ? -1 :    \
+                UNIQ_T(A, aq) > UNIQ_T(B, bq) ? 1 : 0;  \
+        })
+
+#undef CLAMP
+#define CLAMP(x, low, high) __CLAMP(UNIQ, (x), UNIQ, (low), UNIQ, (high))
+#define __CLAMP(xq, x, lowq, low, highq, high)                          \
+        ({                                                              \
+                const typeof(x) UNIQ_T(X, xq) = (x);                    \
+                const typeof(low) UNIQ_T(LOW, lowq) = (low);            \
+                const typeof(high) UNIQ_T(HIGH, highq) = (high);        \
+                        UNIQ_T(X, xq) > UNIQ_T(HIGH, highq) ?           \
+                                UNIQ_T(HIGH, highq) :                   \
+                                UNIQ_T(X, xq) < UNIQ_T(LOW, lowq) ?     \
+                                        UNIQ_T(LOW, lowq) :             \
+                                        UNIQ_T(X, xq);                  \
+        })
+
+/* [(x + y - 1) / y] suffers from an integer overflow, even though the
+ * computation should be possible in the given type. Therefore, we use
+ * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
+ * quotient and the remainder, so both should be equally fast. */
+#define DIV_ROUND_UP(x, y) __DIV_ROUND_UP(UNIQ, (x), UNIQ, (y))
+#define __DIV_ROUND_UP(xq, x, yq, y)                                    \
+        ({                                                              \
+                const typeof(x) UNIQ_T(X, xq) = (x);                    \
+                const typeof(y) UNIQ_T(Y, yq) = (y);                    \
+                (UNIQ_T(X, xq) / UNIQ_T(Y, yq) + !!(UNIQ_T(X, xq) % UNIQ_T(Y, yq))); \
+        })
+
+#ifdef __COVERITY__
+
+/* Use special definitions of assertion macros in order to prevent
+ * false positives of ASSERT_SIDE_EFFECT on Coverity static analyzer
+ * for uses of assert_se() and assert_return().
+ *
+ * These definitions make expression go through a (trivial) function
+ * call to ensure they are not discarded. Also use ! or !! to ensure
+ * the boolean expressions are seen as such.
+ *
+ * This technique has been described and recommended in:
+ * https://community.synopsys.com/s/question/0D534000046Yuzb/suppressing-assertsideeffect-for-functions-that-allow-for-sideeffects
+ */
+
+extern void __coverity_panic__(void);
+
+static inline int __coverity_check__(int condition) {
+        return condition;
+}
+
+#define assert_message_se(expr, message)                                \
+        do {                                                            \
+                if (__coverity_check__(!(expr)))                        \
+                        __coverity_panic__();                           \
+        } while (false)
+
+#define assert_log(expr, message) __coverity_check__(!!(expr))
+
+#else  /* ! __COVERITY__ */
+
+#define assert_message_se(expr, message)                                \
+        do {                                                            \
+                if (_unlikely_(!(expr)))                                \
+                        log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+        } while (false)
+
+#define assert_log(expr, message) ((_likely_(expr))                     \
+        ? (true)                                                        \
+        : (log_assert_failed_return(message, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
+
+#endif  /* __COVERITY__ */
+
+#define assert_se(expr) assert_message_se(expr, #expr)
+
+/* We override the glibc assert() here. */
+#undef assert
+#ifdef NDEBUG
+#define assert(expr) do {} while (false)
+#else
+#define assert(expr) assert_message_se(expr, #expr)
+#endif
+
+#define assert_not_reached(t)                                           \
+        do {                                                            \
+                log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+        } while (false)
+
+#if defined(static_assert)
+#define assert_cc(expr)                                                 \
+        static_assert(expr, #expr);
+#else
+#define assert_cc(expr)                                                 \
+        struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
+                char x[(expr) ? 0 : -1];                                \
+        };
+#endif
+
+#define assert_return(expr, r)                                          \
+        do {                                                            \
+                if (!assert_log(expr, #expr))                           \
+                        return (r);                                     \
+        } while (false)
+
+#define assert_return_errno(expr, r, err)                               \
+        do {                                                            \
+                if (!assert_log(expr, #expr)) {                         \
+                        errno = err;                                    \
+                        return (r);                                     \
+                }                                                       \
+        } while (false)
+
+#define return_with_errno(r, err)                     \
+        do {                                          \
+                errno = abs(err);                     \
+                return r;                             \
+        } while (false)
+
+#define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
+#define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
+#define PTR_TO_UINT(p) ((unsigned) ((uintptr_t) (p)))
+#define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
+
+#define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
+#define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
+#define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
+#define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
+
+#define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
+#define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
+#define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
+#define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
+
+#define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
+#define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
+#define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
+#define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
+
+#define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
+#define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
+
+#define CHAR_TO_STR(x) ((char[2]) { x, 0 })
+
+#define char_array_0(x) x[sizeof(x)-1] = 0;
+
+/* Returns the number of chars needed to format variables of the
+ * specified type as a decimal string. Adds in extra space for a
+ * negative '-' prefix (hence works correctly on signed
+ * types). Includes space for the trailing NUL. */
+#define DECIMAL_STR_MAX(type)                                           \
+        (2+(sizeof(type) <= 1 ? 3 :                                     \
+            sizeof(type) <= 2 ? 5 :                                     \
+            sizeof(type) <= 4 ? 10 :                                    \
+            sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
+
+#define DECIMAL_STR_WIDTH(x)                            \
+        ({                                              \
+                typeof(x) _x_ = (x);                    \
+                unsigned ans = 1;                       \
+                while ((_x_ /= 10) != 0)                \
+                        ans++;                          \
+                ans;                                    \
+        })
+
+#define SET_FLAG(v, flag, b) \
+        (v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
+#define FLAGS_SET(v, flags) \
+        ((~(v) & (flags)) == 0)
+
+#define CASE_F(X) case X:
+#define CASE_F_1(CASE, X) CASE_F(X)
+#define CASE_F_2(CASE, X, ...)  CASE(X) CASE_F_1(CASE, __VA_ARGS__)
+#define CASE_F_3(CASE, X, ...)  CASE(X) CASE_F_2(CASE, __VA_ARGS__)
+#define CASE_F_4(CASE, X, ...)  CASE(X) CASE_F_3(CASE, __VA_ARGS__)
+#define CASE_F_5(CASE, X, ...)  CASE(X) CASE_F_4(CASE, __VA_ARGS__)
+#define CASE_F_6(CASE, X, ...)  CASE(X) CASE_F_5(CASE, __VA_ARGS__)
+#define CASE_F_7(CASE, X, ...)  CASE(X) CASE_F_6(CASE, __VA_ARGS__)
+#define CASE_F_8(CASE, X, ...)  CASE(X) CASE_F_7(CASE, __VA_ARGS__)
+#define CASE_F_9(CASE, X, ...)  CASE(X) CASE_F_8(CASE, __VA_ARGS__)
+#define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
+#define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
+#define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
+#define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
+#define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
+#define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
+#define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
+#define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
+#define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
+#define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
+#define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
+
+#define GET_CASE_F(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,NAME,...) NAME
+#define FOR_EACH_MAKE_CASE(...) \
+        GET_CASE_F(__VA_ARGS__,CASE_F_20,CASE_F_19,CASE_F_18,CASE_F_17,CASE_F_16,CASE_F_15,CASE_F_14,CASE_F_13,CASE_F_12,CASE_F_11, \
+                               CASE_F_10,CASE_F_9,CASE_F_8,CASE_F_7,CASE_F_6,CASE_F_5,CASE_F_4,CASE_F_3,CASE_F_2,CASE_F_1) \
+                   (CASE_F,__VA_ARGS__)
+
+#define IN_SET(x, ...)                          \
+        ({                                      \
+                bool _found = false;            \
+                /* If the build breaks in the line below, you need to extend the case macros. (We use "long double" as  \
+                 * type for the array, in the hope that checkers such as ubsan don't complain that the initializers for \
+                 * the array are not representable by the base type. Ideally we'd use typeof(x) as base type, but that  \
+                 * doesn't work, as we want to use this on bitfields and gcc refuses typeof() on bitfields.) */         \
+                assert_cc((sizeof((long double[]){__VA_ARGS__})/sizeof(long double)) <= 20); \
+                switch(x) {                     \
+                FOR_EACH_MAKE_CASE(__VA_ARGS__) \
+                        _found = true;          \
+                        break;                  \
+                default:                        \
+                        break;                  \
+                }                               \
+                _found;                         \
+        })
+
+#define SWAP_TWO(x, y) do {                        \
+                typeof(x) _t = (x);                \
+                (x) = (y);                         \
+                (y) = (_t);                        \
+        } while (false)
+
+/* Define C11 thread_local attribute even on older gcc compiler
+ * version */
+#ifndef thread_local
+/*
+ * Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
+ * see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
+ */
+#if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
+#define thread_local _Thread_local
+#else
+#define thread_local __thread
+#endif
+#endif
+
+#define DEFINE_TRIVIAL_DESTRUCTOR(name, type, func)             \
+        static inline void name(type *p) {                      \
+                func(p);                                        \
+        }
+
+#define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
+        static inline void func##p(type *p) {                   \
+                if (*p)                                         \
+                        func(*p);                               \
+        }
+
+#define _DEFINE_TRIVIAL_REF_FUNC(type, name, scope)             \
+        scope type *name##_ref(type *p) {                       \
+                if (!p)                                         \
+                        return NULL;                            \
+                                                                \
+                assert(p->n_ref > 0);                           \
+                p->n_ref++;                                     \
+                return p;                                       \
+        }
+
+#define _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, scope) \
+        scope type *name##_unref(type *p) {                      \
+                if (!p)                                          \
+                        return NULL;                             \
+                                                                 \
+                assert(p->n_ref > 0);                            \
+                p->n_ref--;                                      \
+                if (p->n_ref > 0)                                \
+                        return NULL;                             \
+                                                                 \
+                return free_func(p);                             \
+        }
+
+#define DEFINE_TRIVIAL_REF_FUNC(type, name)     \
+        _DEFINE_TRIVIAL_REF_FUNC(type, name,)
+#define DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name)     \
+        _DEFINE_TRIVIAL_REF_FUNC(type, name, static)
+#define DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name)      \
+        _DEFINE_TRIVIAL_REF_FUNC(type, name, _public_)
+
+#define DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func)        \
+        _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func,)
+#define DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func)        \
+        _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, static)
+#define DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func)         \
+        _DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func, _public_)
+
+#define DEFINE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
+        DEFINE_TRIVIAL_REF_FUNC(type, name);                    \
+        DEFINE_TRIVIAL_UNREF_FUNC(type, name, free_func);
+
+#define DEFINE_PRIVATE_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
+        DEFINE_PRIVATE_TRIVIAL_REF_FUNC(type, name);                    \
+        DEFINE_PRIVATE_TRIVIAL_UNREF_FUNC(type, name, free_func);
+
+#define DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(type, name, free_func)    \
+        DEFINE_PUBLIC_TRIVIAL_REF_FUNC(type, name);                    \
+        DEFINE_PUBLIC_TRIVIAL_UNREF_FUNC(type, name, free_func);
+
+#include "log.h"
diff --git a/src/basic/memfd-util.c b/src/basic/memfd-util.c
new file mode 100644
index 0000000..f88f0fc
--- /dev/null
+++ b/src/basic/memfd-util.c
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#if HAVE_LINUX_MEMFD_H
+#include <linux/memfd.h>
+#endif
+#include <stdio.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "macro.h"
+#include "memfd-util.h"
+#include "missing.h"
+#include "string-util.h"
+#include "utf8.h"
+
+int memfd_new(const char *name) {
+        _cleanup_free_ char *g = NULL;
+        int fd;
+
+        if (!name) {
+                char pr[17] = {};
+
+                /* If no name is specified we generate one. We include
+                 * a hint indicating our library implementation, and
+                 * add the thread name to it */
+
+                assert_se(prctl(PR_GET_NAME, (unsigned long) pr) >= 0);
+
+                if (isempty(pr))
+                        name = "sd";
+                else {
+                        _cleanup_free_ char *e = NULL;
+
+                        e = utf8_escape_invalid(pr);
+                        if (!e)
+                                return -ENOMEM;
+
+                        g = strappend("sd-", e);
+                        if (!g)
+                                return -ENOMEM;
+
+                        name = g;
+                }
+        }
+
+        fd = memfd_create(name, MFD_ALLOW_SEALING | MFD_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        return fd;
+}
+
+int memfd_map(int fd, uint64_t offset, size_t size, void **p) {
+        void *q;
+        int sealed;
+
+        assert(fd >= 0);
+        assert(size > 0);
+        assert(p);
+
+        sealed = memfd_get_sealed(fd);
+        if (sealed < 0)
+                return sealed;
+
+        if (sealed)
+                q = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, offset);
+        else
+                q = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, offset);
+
+        if (q == MAP_FAILED)
+                return -errno;
+
+        *p = q;
+        return 0;
+}
+
+int memfd_set_sealed(int fd) {
+        int r;
+
+        assert(fd >= 0);
+
+        r = fcntl(fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE | F_SEAL_SEAL);
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+int memfd_get_sealed(int fd) {
+        int r;
+
+        assert(fd >= 0);
+
+        r = fcntl(fd, F_GET_SEALS);
+        if (r < 0)
+                return -errno;
+
+        return r == (F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE | F_SEAL_SEAL);
+}
+
+int memfd_get_size(int fd, uint64_t *sz) {
+        struct stat stat;
+        int r;
+
+        assert(fd >= 0);
+        assert(sz);
+
+        r = fstat(fd, &stat);
+        if (r < 0)
+                return -errno;
+
+        *sz = stat.st_size;
+        return 0;
+}
+
+int memfd_set_size(int fd, uint64_t sz) {
+        int r;
+
+        assert(fd >= 0);
+
+        r = ftruncate(fd, sz);
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+int memfd_new_and_map(const char *name, size_t sz, void **p) {
+        _cleanup_close_ int fd = -1;
+        int r;
+
+        assert(sz > 0);
+        assert(p);
+
+        fd = memfd_new(name);
+        if (fd < 0)
+                return fd;
+
+        r = memfd_set_size(fd, sz);
+        if (r < 0)
+                return r;
+
+        r = memfd_map(fd, 0, sz, p);
+        if (r < 0)
+                return r;
+
+        return TAKE_FD(fd);
+}
diff --git a/src/basic/memfd-util.h b/src/basic/memfd-util.h
new file mode 100644
index 0000000..5ebb519
--- /dev/null
+++ b/src/basic/memfd-util.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+int memfd_new(const char *name);
+int memfd_new_and_map(const char *name, size_t sz, void **p);
+
+int memfd_map(int fd, uint64_t offset, size_t size, void **p);
+
+int memfd_set_sealed(int fd);
+int memfd_get_sealed(int fd);
+
+int memfd_get_size(int fd, uint64_t *sz);
+int memfd_set_size(int fd, uint64_t sz);
diff --git a/src/basic/mempool.c b/src/basic/mempool.c
new file mode 100644
index 0000000..159c963
--- /dev/null
+++ b/src/basic/mempool.c
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "env-util.h"
+#include "macro.h"
+#include "mempool.h"
+#include "process-util.h"
+#include "util.h"
+
+struct pool {
+        struct pool *next;
+        size_t n_tiles;
+        size_t n_used;
+};
+
+void* mempool_alloc_tile(struct mempool *mp) {
+        size_t i;
+
+        /* When a tile is released we add it to the list and simply
+         * place the next pointer at its offset 0. */
+
+        assert(mp->tile_size >= sizeof(void*));
+        assert(mp->at_least > 0);
+
+        if (mp->freelist) {
+                void *r;
+
+                r = mp->freelist;
+                mp->freelist = * (void**) mp->freelist;
+                return r;
+        }
+
+        if (_unlikely_(!mp->first_pool) ||
+            _unlikely_(mp->first_pool->n_used >= mp->first_pool->n_tiles)) {
+                size_t size, n;
+                struct pool *p;
+
+                n = mp->first_pool ? mp->first_pool->n_tiles : 0;
+                n = MAX(mp->at_least, n * 2);
+                size = PAGE_ALIGN(ALIGN(sizeof(struct pool)) + n*mp->tile_size);
+                n = (size - ALIGN(sizeof(struct pool))) / mp->tile_size;
+
+                p = malloc(size);
+                if (!p)
+                        return NULL;
+
+                p->next = mp->first_pool;
+                p->n_tiles = n;
+                p->n_used = 0;
+
+                mp->first_pool = p;
+        }
+
+        i = mp->first_pool->n_used++;
+
+        return ((uint8_t*) mp->first_pool) + ALIGN(sizeof(struct pool)) + i*mp->tile_size;
+}
+
+void* mempool_alloc0_tile(struct mempool *mp) {
+        void *p;
+
+        p = mempool_alloc_tile(mp);
+        if (p)
+                memzero(p, mp->tile_size);
+        return p;
+}
+
+void mempool_free_tile(struct mempool *mp, void *p) {
+        * (void**) p = mp->freelist;
+        mp->freelist = p;
+}
+
+bool mempool_enabled(void) {
+        static int b = -1;
+
+        if (!is_main_thread())
+                return false;
+
+        if (!mempool_use_allowed)
+                b = false;
+        if (b < 0)
+                b = getenv_bool("SYSTEMD_MEMPOOL") != 0;
+
+        return b;
+}
+
+#if VALGRIND
+void mempool_drop(struct mempool *mp) {
+        struct pool *p = mp->first_pool;
+        while (p) {
+                struct pool *n;
+                n = p->next;
+                free(p);
+                p = n;
+        }
+}
+#endif
diff --git a/src/basic/mempool.h b/src/basic/mempool.h
new file mode 100644
index 0000000..0eecca0
--- /dev/null
+++ b/src/basic/mempool.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+
+struct pool;
+
+struct mempool {
+        struct pool *first_pool;
+        void *freelist;
+        size_t tile_size;
+        unsigned at_least;
+};
+
+void* mempool_alloc_tile(struct mempool *mp);
+void* mempool_alloc0_tile(struct mempool *mp);
+void mempool_free_tile(struct mempool *mp, void *p);
+
+#define DEFINE_MEMPOOL(pool_name, tile_type, alloc_at_least) \
+static struct mempool pool_name = { \
+        .tile_size = sizeof(tile_type), \
+        .at_least = alloc_at_least, \
+}
+
+extern const bool mempool_use_allowed;
+bool mempool_enabled(void);
+
+#if VALGRIND
+void mempool_drop(struct mempool *mp);
+#endif
diff --git a/src/basic/meson.build b/src/basic/meson.build
new file mode 100644
index 0000000..e5852f3
--- /dev/null
+++ b/src/basic/meson.build
@@ -0,0 +1,310 @@
+# SPDX-License-Identifier: LGPL-2.1+
+
+basic_sources = files('''
+        MurmurHash2.c
+        MurmurHash2.h
+        af-list.c
+        af-list.h
+        alloc-util.c
+        alloc-util.h
+        architecture.c
+        architecture.h
+        arphrd-list.c
+        arphrd-list.h
+        async.c
+        async.h
+        audit-util.c
+        audit-util.h
+        blockdev-util.c
+        blockdev-util.h
+        btrfs-util.c
+        btrfs-util.h
+        build.h
+        bus-label.c
+        bus-label.h
+        cap-list.c
+        cap-list.h
+        capability-util.c
+        capability-util.h
+        cgroup-util.c
+        cgroup-util.h
+        chattr-util.c
+        chattr-util.h
+        conf-files.c
+        conf-files.h
+        copy.c
+        copy.h
+        def.h
+        device-nodes.c
+        device-nodes.h
+        dirent-util.c
+        dirent-util.h
+        env-file.c
+        env-file.h
+        env-util.c
+        env-util.h
+        errno-list.c
+        errno-list.h
+        escape.c
+        escape.h
+        ether-addr-util.c
+        ether-addr-util.h
+        extract-word.c
+        extract-word.h
+        fd-util.c
+        fd-util.h
+        fileio.c
+        fileio.h
+        format-util.h
+        fs-util.c
+        fs-util.h
+        glob-util.c
+        glob-util.h
+        gunicode.c
+        gunicode.h
+        hash-funcs.c
+        hash-funcs.h
+        hashmap.c
+        hashmap.h
+        hexdecoct.c
+        hexdecoct.h
+        hostname-util.c
+        hostname-util.h
+        in-addr-util.c
+        in-addr-util.h
+        io-util.c
+        io-util.h
+        ioprio.h
+        khash.c
+        khash.h
+        label.c
+        label.h
+        list.h
+        locale-util.c
+        locale-util.h
+        log.c
+        log.h
+        login-util.c
+        login-util.h
+        macro.h
+        memfd-util.c
+        memfd-util.h
+        mempool.c
+        mempool.h
+        missing.h
+        missing_audit.h
+        missing_btrfs.h
+        missing_btrfs_tree.h
+        missing_capability.h
+        missing_drm.h
+        missing_ethtool.h
+        missing_fcntl.h
+        missing_fib_rules.h
+        missing_fou.h
+        missing_fs.h
+        missing_if_bridge.h
+        missing_if_link.h
+        missing_if_tunnel.h
+        missing_input.h
+        missing_keyctl.h
+        missing_magic.h
+        missing_mman.h
+        missing_network.h
+        missing_prctl.h
+        missing_random.h
+        missing_resource.h
+        missing_sched.h
+        missing_securebits.h
+        missing_socket.h
+        missing_stat.h
+        missing_stdlib.h
+        missing_syscall.h
+        missing_timerfd.h
+        missing_type.h
+        missing_vxcan.h
+        mkdir-label.c
+        mkdir.c
+        mkdir.h
+        mountpoint-util.c
+        mountpoint-util.h
+        nss-util.h
+        ordered-set.c
+        ordered-set.h
+        parse-util.c
+        parse-util.h
+        path-util.c
+        path-util.h
+        prioq.c
+        prioq.h
+        proc-cmdline.c
+        proc-cmdline.h
+        process-util.c
+        process-util.h
+        procfs-util.c
+        procfs-util.h
+        random-util.c
+        random-util.h
+        ratelimit.c
+        ratelimit.h
+        raw-clone.h
+        raw-reboot.h
+        refcnt.h
+        replace-var.c
+        replace-var.h
+        rlimit-util.c
+        rlimit-util.h
+        rm-rf.c
+        rm-rf.h
+        selinux-util.c
+        selinux-util.h
+        set.h
+        sigbus.c
+        sigbus.h
+        signal-util.c
+        signal-util.h
+        siphash24.c
+        siphash24.h
+        smack-util.c
+        smack-util.h
+        socket-label.c
+        socket-util.c
+        socket-util.h
+        sparse-endian.h
+        special.h
+        stat-util.c
+        stat-util.h
+        static-destruct.h
+        stdio-util.h
+        strbuf.c
+        strbuf.h
+        string-table.c
+        string-table.h
+        string-util.c
+        string-util.h
+        strv.c
+        strv.h
+        strxcpyx.c
+        strxcpyx.h
+        syslog-util.c
+        syslog-util.h
+        terminal-util.c
+        terminal-util.h
+        time-util.c
+        time-util.h
+        tmpfile-util.c
+        tmpfile-util.h
+        umask-util.h
+        unaligned.h
+        unit-def.c
+        unit-def.h
+        unit-name.c
+        unit-name.h
+        user-util.c
+        user-util.h
+        utf8.c
+        utf8.h
+        util.c
+        util.h
+        virt.c
+        virt.h
+        xattr-util.c
+        xattr-util.h
+'''.split())
+
+missing_audit_h = files('missing_audit.h')
+missing_capability_h = files('missing_capability.h')
+missing_network_h = files('missing_network.h')
+missing_socket_h = files('missing_socket.h')
+
+generate_af_list = find_program('generate-af-list.sh')
+af_list_txt = custom_target(
+        'af-list.txt',
+        output : 'af-list.txt',
+        command : [generate_af_list, cpp, config_h, missing_socket_h],
+        capture : true)
+
+generate_arphrd_list = find_program('generate-arphrd-list.sh')
+arphrd_list_txt = custom_target(
+        'arphrd-list.txt',
+        output : 'arphrd-list.txt',
+        command : [generate_arphrd_list, cpp, config_h, missing_network_h],
+        capture : true)
+
+generate_cap_list = find_program('generate-cap-list.sh')
+cap_list_txt = custom_target(
+        'cap-list.txt',
+        output : 'cap-list.txt',
+        command : [generate_cap_list, cpp, config_h, missing_capability_h],
+        capture : true)
+
+generate_errno_list = find_program('generate-errno-list.sh')
+errno_list_txt = custom_target(
+        'errno-list.txt',
+        output : 'errno-list.txt',
+        command : [generate_errno_list, cpp],
+        capture : true)
+
+generated_gperf_headers = []
+foreach item : [['af',     af_list_txt,     'af',         ''],
+                ['arphrd', arphrd_list_txt, 'arphrd',     'ARPHRD_'],
+                ['cap',    cap_list_txt,    'capability', ''],
+                ['errno',  errno_list_txt,  'errno',      '']]
+
+        fname = '@0@-from-name.gperf'.format(item[0])
+        gperf_file = custom_target(
+                fname,
+                input : item[1],
+                output : fname,
+                command : [generate_gperfs, item[2], item[3], '@INPUT@'],
+                capture : true)
+
+        fname = '@0@-from-name.h'.format(item[0])
+        target1 = custom_target(
+                fname,
+                input : gperf_file,
+                output : fname,
+                command : [gperf,
+                           '-L', 'ANSI-C', '-t', '--ignore-case',
+                           '-N', 'lookup_@0@'.format(item[2]),
+                           '-H', 'hash_@0@_name'.format(item[2]),
+                           '-p', '-C',
+                           '@INPUT@'],
+                capture : true)
+
+        fname = '@0@-to-name.h'.format(item[0])
+        awkscript = '@0@-to-name.awk'.format(item[0])
+        target2 = custom_target(
+                fname,
+                input : [awkscript, item[1]],
+                output : fname,
+                command : [awk, '-f', '@INPUT0@', '@INPUT1@'],
+                capture : true)
+
+        generated_gperf_headers += [target1, target2]
+endforeach
+
+basic_sources += generated_gperf_headers
+basic_gcrypt_sources = files(
+        'gcrypt-util.c',
+        'gcrypt-util.h')
+
+libbasic = static_library(
+        'basic',
+        basic_sources,
+        include_directories : includes,
+        dependencies : [versiondep,
+                        threads,
+                        libcap,
+                        libselinux,
+                        libm],
+        c_args : ['-fvisibility=default'],
+        install : false)
+
+# A convenience library that is separate from libbasic to avoid
+# unnecessary linking to libgcrypt.
+libbasic_gcrypt = static_library(
+        'basic-gcrypt',
+        basic_gcrypt_sources,
+        include_directories : includes,
+        dependencies : [libgcrypt],
+        c_args : ['-fvisibility=default'])
diff --git a/src/basic/missing.h b/src/basic/missing.h
new file mode 100644
index 0000000..5067c8f
--- /dev/null
+++ b/src/basic/missing.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/* Missing glibc definitions to access certain kernel APIs */
+
+#include "missing_audit.h"
+#include "missing_btrfs_tree.h"
+#include "missing_capability.h"
+#include "missing_drm.h"
+#include "missing_fcntl.h"
+#include "missing_fs.h"
+#include "missing_input.h"
+#include "missing_magic.h"
+#include "missing_mman.h"
+#include "missing_network.h"
+#include "missing_prctl.h"
+#include "missing_random.h"
+#include "missing_resource.h"
+#include "missing_sched.h"
+#include "missing_socket.h"
+#include "missing_stdlib.h"
+#include "missing_timerfd.h"
+#include "missing_type.h"
+
+#include "missing_syscall.h"
diff --git a/src/basic/missing_audit.h b/src/basic/missing_audit.h
new file mode 100644
index 0000000..b00d537
--- /dev/null
+++ b/src/basic/missing_audit.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/audit.h>
+
+#if HAVE_AUDIT
+#include <libaudit.h>
+#endif
+
+#ifndef AUDIT_SERVICE_START
+#define AUDIT_SERVICE_START 1130 /* Service (daemon) start */
+#endif
+
+#ifndef AUDIT_SERVICE_STOP
+#define AUDIT_SERVICE_STOP 1131 /* Service (daemon) stop */
+#endif
+
+#ifndef MAX_AUDIT_MESSAGE_LENGTH
+#define MAX_AUDIT_MESSAGE_LENGTH 8970
+#endif
+
+#ifndef AUDIT_NLGRP_MAX
+#define AUDIT_NLGRP_READLOG 1
+#endif
diff --git a/src/basic/missing_btrfs.h b/src/basic/missing_btrfs.h
new file mode 100644
index 0000000..34c382f
--- /dev/null
+++ b/src/basic/missing_btrfs.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/* Old btrfs.h requires stddef.h to be included before btrfs.h */
+#include <stddef.h>
+
+#include <linux/btrfs.h>
+
+/* linux@57254b6ebce4ceca02d9c8b615f6059c56c19238 (3.11) */
+#ifndef BTRFS_IOC_QUOTA_RESCAN_WAIT
+#define BTRFS_IOC_QUOTA_RESCAN_WAIT _IO(BTRFS_IOCTL_MAGIC, 46)
+#endif
+
+/* linux@83288b60bf6668933689078973136e0c9d387b38 (4.7) */
+#ifndef BTRFS_QGROUP_LIMIT_MAX_RFER
+#define BTRFS_QGROUP_LIMIT_MAX_RFER	(1ULL << 0)
+#define BTRFS_QGROUP_LIMIT_MAX_EXCL	(1ULL << 1)
+#define BTRFS_QGROUP_LIMIT_RSV_RFER	(1ULL << 2)
+#define BTRFS_QGROUP_LIMIT_RSV_EXCL	(1ULL << 3)
+#define BTRFS_QGROUP_LIMIT_RFER_CMPR	(1ULL << 4)
+#define BTRFS_QGROUP_LIMIT_EXCL_CMPR	(1ULL << 5)
+#endif
diff --git a/src/basic/missing_btrfs_tree.h b/src/basic/missing_btrfs_tree.h
new file mode 100644
index 0000000..555f90f
--- /dev/null
+++ b/src/basic/missing_btrfs_tree.h
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/types.h>
+
+#include "missing_btrfs.h"
+
+/* linux@db6711600e27c885aed89751f04e727f3af26715 (4.7) */
+#if HAVE_LINUX_BTRFS_TREE_H
+#include <linux/btrfs_tree.h>
+#else
+#define BTRFS_ROOT_TREE_OBJECTID  1
+#define BTRFS_QUOTA_TREE_OBJECTID 8
+#define BTRFS_FIRST_FREE_OBJECTID 256
+#define BTRFS_LAST_FREE_OBJECTID -256ULL
+
+#define BTRFS_ROOT_ITEM_KEY       132
+#define BTRFS_ROOT_BACKREF_KEY    144
+#define BTRFS_QGROUP_STATUS_KEY   240
+#define BTRFS_QGROUP_INFO_KEY     242
+#define BTRFS_QGROUP_LIMIT_KEY    244
+#define BTRFS_QGROUP_RELATION_KEY 246
+
+struct btrfs_disk_key {
+        __le64 objectid;
+        __u8 type;
+        __le64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_timespec {
+        __le64 sec;
+        __le32 nsec;
+} __attribute__ ((__packed__));
+
+struct btrfs_inode_item {
+        __le64 generation;
+        __le64 transid;
+        __le64 size;
+        __le64 nbytes;
+        __le64 block_group;
+        __le32 nlink;
+        __le32 uid;
+        __le32 gid;
+        __le32 mode;
+        __le64 rdev;
+        __le64 flags;
+        __le64 sequence;
+        __le64 reserved[4];
+        struct btrfs_timespec atime;
+        struct btrfs_timespec ctime;
+        struct btrfs_timespec mtime;
+        struct btrfs_timespec otime;
+} __attribute__ ((__packed__));
+
+#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
+
+struct btrfs_root_item {
+        struct btrfs_inode_item inode;
+        __le64 generation;
+        __le64 root_dirid;
+        __le64 bytenr;
+        __le64 byte_limit;
+        __le64 bytes_used;
+        __le64 last_snapshot;
+        __le64 flags;
+        __le32 refs;
+        struct btrfs_disk_key drop_progress;
+        __u8 drop_level;
+        __u8 level;
+
+        __le64 generation_v2;
+        __u8 uuid[BTRFS_UUID_SIZE];
+        __u8 parent_uuid[BTRFS_UUID_SIZE];
+        __u8 received_uuid[BTRFS_UUID_SIZE];
+        __le64 ctransid; /* updated when an inode changes */
+        __le64 otransid; /* trans when created */
+        __le64 stransid; /* trans when sent. non-zero for received subvol */
+        __le64 rtransid; /* trans when received. non-zero for received subvol */
+        struct btrfs_timespec ctime;
+        struct btrfs_timespec otime;
+        struct btrfs_timespec stime;
+        struct btrfs_timespec rtime;
+        __le64 reserved[8]; /* for future */
+} __attribute__ ((__packed__));
+
+struct btrfs_root_ref {
+        __le64 dirid;
+        __le64 sequence;
+        __le16 name_len;
+} __attribute__ ((__packed__));
+
+#define BTRFS_QGROUP_LEVEL_SHIFT  48
+
+struct btrfs_qgroup_info_item {
+        __le64 generation;
+        __le64 rfer;
+        __le64 rfer_cmpr;
+        __le64 excl;
+        __le64 excl_cmpr;
+} __attribute__ ((__packed__));
+
+struct btrfs_qgroup_limit_item {
+        __le64 flags;
+        __le64 max_rfer;
+        __le64 max_excl;
+        __le64 rsv_rfer;
+        __le64 rsv_excl;
+} __attribute__ ((__packed__));
+#endif
diff --git a/src/basic/missing_capability.h b/src/basic/missing_capability.h
new file mode 100644
index 0000000..1308a3d
--- /dev/null
+++ b/src/basic/missing_capability.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/capability.h>
+
+/* 3a101b8de0d39403b2c7e5c23fd0b005668acf48 (3.16) */
+#ifndef CAP_AUDIT_READ
+#define CAP_AUDIT_READ 37
+
+#undef  CAP_LAST_CAP
+#define CAP_LAST_CAP   CAP_AUDIT_READ
+#endif
diff --git a/src/basic/missing_drm.h b/src/basic/missing_drm.h
new file mode 100644
index 0000000..a64f74e
--- /dev/null
+++ b/src/basic/missing_drm.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#ifndef DRM_IOCTL_SET_MASTER
+#define DRM_IOCTL_SET_MASTER _IO('d', 0x1e)
+#endif
+
+#ifndef DRM_IOCTL_DROP_MASTER
+#define DRM_IOCTL_DROP_MASTER _IO('d', 0x1f)
+#endif
diff --git a/src/basic/missing_ethtool.h b/src/basic/missing_ethtool.h
new file mode 100644
index 0000000..9ba929c
--- /dev/null
+++ b/src/basic/missing_ethtool.h
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/types.h>
+
+/* Missing definitions in ethtool.h */
+
+#if !HAVE_ETHTOOL_LINK_MODE_10baseT_Half_BIT /* linux@3f1ac7a700d039c61d8d8b99f28d605d489a60cf (4.6) */
+
+#define ETHTOOL_GLINKSETTINGS   0x0000004c /* Get ethtool_link_settings */
+#define ETHTOOL_SLINKSETTINGS   0x0000004d /* Set ethtool_link_settings */
+
+struct ethtool_link_settings {
+        __u32 cmd;
+        __u32 speed;
+        __u8  duplex;
+        __u8  port;
+        __u8  phy_address;
+        __u8  autoneg;
+        __u8  mdio_support;
+        __u8  eth_tp_mdix;
+        __u8  eth_tp_mdix_ctrl;
+        __s8  link_mode_masks_nwords;
+        __u8  transceiver;
+        __u8  reserved1[3];
+        __u32 reserved[7];
+        __u32 link_mode_masks[0];
+        /* layout of link_mode_masks fields:
+         * __u32 map_supported[link_mode_masks_nwords];
+         * __u32 map_advertising[link_mode_masks_nwords];
+         * __u32 map_lp_advertising[link_mode_masks_nwords];
+         */
+};
+
+enum ethtool_link_mode_bit_indices {
+        ETHTOOL_LINK_MODE_10baseT_Half_BIT           = 0,
+        ETHTOOL_LINK_MODE_10baseT_Full_BIT           = 1,
+        ETHTOOL_LINK_MODE_100baseT_Half_BIT          = 2,
+        ETHTOOL_LINK_MODE_100baseT_Full_BIT          = 3,
+        ETHTOOL_LINK_MODE_1000baseT_Half_BIT         = 4,
+        ETHTOOL_LINK_MODE_1000baseT_Full_BIT         = 5,
+        ETHTOOL_LINK_MODE_Autoneg_BIT                = 6,
+        ETHTOOL_LINK_MODE_TP_BIT                     = 7,
+        ETHTOOL_LINK_MODE_AUI_BIT                    = 8,
+        ETHTOOL_LINK_MODE_MII_BIT                    = 9,
+        ETHTOOL_LINK_MODE_FIBRE_BIT                  = 10,
+        ETHTOOL_LINK_MODE_BNC_BIT                    = 11,
+        ETHTOOL_LINK_MODE_10000baseT_Full_BIT        = 12,
+        ETHTOOL_LINK_MODE_Pause_BIT                  = 13,
+        ETHTOOL_LINK_MODE_Asym_Pause_BIT             = 14,
+        ETHTOOL_LINK_MODE_2500baseX_Full_BIT         = 15,
+        ETHTOOL_LINK_MODE_Backplane_BIT              = 16,
+        ETHTOOL_LINK_MODE_1000baseKX_Full_BIT        = 17,
+        ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT      = 18,
+        ETHTOOL_LINK_MODE_10000baseKR_Full_BIT       = 19,
+        ETHTOOL_LINK_MODE_10000baseR_FEC_BIT         = 20,
+        ETHTOOL_LINK_MODE_20000baseMLD2_Full_BIT     = 21,
+        ETHTOOL_LINK_MODE_20000baseKR2_Full_BIT      = 22,
+        ETHTOOL_LINK_MODE_40000baseKR4_Full_BIT      = 23,
+        ETHTOOL_LINK_MODE_40000baseCR4_Full_BIT      = 24,
+        ETHTOOL_LINK_MODE_40000baseSR4_Full_BIT      = 25,
+        ETHTOOL_LINK_MODE_40000baseLR4_Full_BIT      = 26,
+        ETHTOOL_LINK_MODE_56000baseKR4_Full_BIT      = 27,
+        ETHTOOL_LINK_MODE_56000baseCR4_Full_BIT      = 28,
+        ETHTOOL_LINK_MODE_56000baseSR4_Full_BIT      = 29,
+        ETHTOOL_LINK_MODE_56000baseLR4_Full_BIT      = 30,
+        ETHTOOL_LINK_MODE_25000baseCR_Full_BIT       = 31,
+        ETHTOOL_LINK_MODE_25000baseKR_Full_BIT       = 32,
+        ETHTOOL_LINK_MODE_25000baseSR_Full_BIT       = 33,
+        ETHTOOL_LINK_MODE_50000baseCR2_Full_BIT      = 34,
+        ETHTOOL_LINK_MODE_50000baseKR2_Full_BIT      = 35,
+        ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT     = 36,
+        ETHTOOL_LINK_MODE_100000baseSR4_Full_BIT     = 37,
+        ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT     = 38,
+        ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT = 39,
+        ETHTOOL_LINK_MODE_50000baseSR2_Full_BIT      = 40,
+        ETHTOOL_LINK_MODE_1000baseX_Full_BIT         = 41,
+        ETHTOOL_LINK_MODE_10000baseCR_Full_BIT       = 42,
+        ETHTOOL_LINK_MODE_10000baseSR_Full_BIT       = 43,
+        ETHTOOL_LINK_MODE_10000baseLR_Full_BIT       = 44,
+        ETHTOOL_LINK_MODE_10000baseLRM_Full_BIT      = 45,
+        ETHTOOL_LINK_MODE_10000baseER_Full_BIT       = 46,
+        ETHTOOL_LINK_MODE_2500baseT_Full_BIT         = 47,
+        ETHTOOL_LINK_MODE_5000baseT_Full_BIT         = 48,
+
+        ETHTOOL_LINK_MODE_FEC_NONE_BIT               = 49,
+        ETHTOOL_LINK_MODE_FEC_RS_BIT                 = 50,
+        ETHTOOL_LINK_MODE_FEC_BASER_BIT              = 51,
+
+        /* Last allowed bit for __ETHTOOL_LINK_MODE_LEGACY_MASK is bit
+         * 31. Please do NOT define any SUPPORTED_* or ADVERTISED_*
+         * macro for bits > 31. The only way to use indices > 31 is to
+         * use the new ETHTOOL_GLINKSETTINGS/ETHTOOL_SLINKSETTINGS API.
+         */
+
+        __ETHTOOL_LINK_MODE_LAST
+          = ETHTOOL_LINK_MODE_FEC_BASER_BIT,
+};
+#else
+#if !HAVE_ETHTOOL_LINK_MODE_25000baseCR_Full_BIT /* linux@3851112e4737cd52aaeda0ce8d084be9ee128106 (4.7) */
+#define ETHTOOL_LINK_MODE_25000baseCR_Full_BIT       31
+#define ETHTOOL_LINK_MODE_25000baseKR_Full_BIT       32
+#define ETHTOOL_LINK_MODE_25000baseSR_Full_BIT       33
+#define ETHTOOL_LINK_MODE_50000baseCR2_Full_BIT      34
+#define ETHTOOL_LINK_MODE_50000baseKR2_Full_BIT      35
+#define ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT     36
+#define ETHTOOL_LINK_MODE_100000baseSR4_Full_BIT     37
+#define ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT     38
+#define ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT 39
+#endif
+#if !HAVE_ETHTOOL_LINK_MODE_50000baseSR2_Full_BIT /* linux@89da45b8b5b2187734a11038b8593714f964ffd1 (4.8) */
+#define ETHTOOL_LINK_MODE_50000baseSR2_Full_BIT      40
+#endif
+#if !HAVE_ETHTOOL_LINK_MODE_1000baseX_Full_BIT /* linux@5711a98221443aec54c4c81ee98c6ae46acccb65 (4.9) */
+#define ETHTOOL_LINK_MODE_1000baseX_Full_BIT         41
+#define ETHTOOL_LINK_MODE_10000baseCR_Full_BIT       42
+#define ETHTOOL_LINK_MODE_10000baseSR_Full_BIT       43
+#define ETHTOOL_LINK_MODE_10000baseLR_Full_BIT       44
+#define ETHTOOL_LINK_MODE_10000baseLRM_Full_BIT      45
+#define ETHTOOL_LINK_MODE_10000baseER_Full_BIT       46
+#endif
+#if !HAVE_ETHTOOL_LINK_MODE_2500baseT_Full_BIT /* linux@94842b4fc4d6b1691cfc86c6f5251f299d27f4ba (4.10) */
+#define ETHTOOL_LINK_MODE_2500baseT_Full_BIT         47
+#define ETHTOOL_LINK_MODE_5000baseT_Full_BIT         48
+#endif
+#if !HAVE_ETHTOOL_LINK_MODE_FEC_NONE_BIT /* linux@1a5f3da20bd966220931239fbd31e6ac6ff42251 (4.14) */
+#define ETHTOOL_LINK_MODE_FEC_NONE_BIT               49
+#define ETHTOOL_LINK_MODE_FEC_RS_BIT                 50
+#define ETHTOOL_LINK_MODE_FEC_BASER_BIT              51
+#endif
+#endif
diff --git a/src/basic/missing_fcntl.h b/src/basic/missing_fcntl.h
new file mode 100644
index 0000000..5d1c635
--- /dev/null
+++ b/src/basic/missing_fcntl.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <fcntl.h>
+
+#ifndef F_LINUX_SPECIFIC_BASE
+#define F_LINUX_SPECIFIC_BASE 1024
+#endif
+
+#ifndef F_SETPIPE_SZ
+#define F_SETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 7)
+#endif
+
+#ifndef F_GETPIPE_SZ
+#define F_GETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 8)
+#endif
+
+#ifndef F_ADD_SEALS
+#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
+#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10)
+
+#define F_SEAL_SEAL     0x0001  /* prevent further seals from being set */
+#define F_SEAL_SHRINK   0x0002  /* prevent file from shrinking */
+#define F_SEAL_GROW     0x0004  /* prevent file from growing */
+#define F_SEAL_WRITE    0x0008  /* prevent writes */
+#endif
+
+#ifndef F_OFD_GETLK
+#define F_OFD_GETLK     36
+#define F_OFD_SETLK     37
+#define F_OFD_SETLKW    38
+#endif
+
+#ifndef MAX_HANDLE_SZ
+#define MAX_HANDLE_SZ 128
+#endif
+
+/* The precise definition of __O_TMPFILE is arch specific; use the
+ * values defined by the kernel (note: some are hexa, some are octal,
+ * duplicated as-is from the kernel definitions):
+ * - alpha, parisc, sparc: each has a specific value;
+ * - others: they use the "generic" value.
+ */
+
+#ifndef __O_TMPFILE
+#if defined(__alpha__)
+#define __O_TMPFILE     0100000000
+#elif defined(__parisc__) || defined(__hppa__)
+#define __O_TMPFILE     0400000000
+#elif defined(__sparc__) || defined(__sparc64__)
+#define __O_TMPFILE     0x2000000
+#else
+#define __O_TMPFILE     020000000
+#endif
+#endif
+
+/* a horrid kludge trying to make sure that this will fail on old kernels */
+#ifndef O_TMPFILE
+#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
+#endif
diff --git a/src/basic/missing_fib_rules.h b/src/basic/missing_fib_rules.h
new file mode 100644
index 0000000..df120d7
--- /dev/null
+++ b/src/basic/missing_fib_rules.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/types.h>
+
+#if !HAVE_FRA_TUN_ID /* linux@e7030878fc8448492b6e5cecd574043f63271298 (4.3) */
+#define FRA_TUN_ID      12
+#endif
+
+#if !HAVE_FRA_SUPPRESS_PREFIXLEN /* linux@6ef94cfafba159d6b1a902ccb3349ac6a34ff6ad, 73f5698e77219bfc3ea1903759fe8e20ab5b285e (3.12) */
+#define FRA_SUPPRESS_IFGROUP 13
+#define FRA_SUPPRESS_PREFIXLEN 14
+#endif
+
+#if !HAVE_FRA_PAD /* linux@b46f6ded906ef0be52a4881ba50a084aeca64d7e (4.7) */
+#define FRA_PAD         18
+#endif
+
+#if !HAVE_FRA_L3MDEV /* linux@96c63fa7393d0a346acfe5a91e0c7d4c7782641b (4.8) */
+#define FRA_L3MDEV      19
+#endif
+
+#if !HAVE_FRA_UID_RANGE /* linux@622ec2c9d52405973c9f1ca5116eb1c393adfc7d (4.10) */
+#define FRA_UID_RANGE   20
+
+struct fib_rule_uid_range {
+        __u32 start;
+        __u32 end;
+};
+#endif
+
+#if !HAVE_FRA_DPORT_RANGE /* linux@1b71af6053af1bd2f849e9fda4f71c1e3f145dcf, bfff4862653bb96001ab57c1edd6d03f48e5f035 (4.17) */
+#define FRA_PROTOCOL    21
+#define FRA_IP_PROTO    22
+#define FRA_SPORT_RANGE 23
+#define FRA_DPORT_RANGE 24
+
+#undef  FRA_MAX
+#define FRA_MAX         24
+
+struct fib_rule_port_range {
+        __u16 start;
+        __u16 end;
+};
+#endif
diff --git a/src/basic/missing_fou.h b/src/basic/missing_fou.h
new file mode 100644
index 0000000..d8c7435
--- /dev/null
+++ b/src/basic/missing_fou.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#if !HAVE_LINUX_FOU_H /* linux@23461551c00628c3f3fe9cf837bf53cf8f212b63 (3.18) */
+
+#define FOU_GENL_NAME           "fou"
+#define FOU_GENL_VERSION        0x1
+
+enum {
+        FOU_ATTR_UNSPEC,
+        FOU_ATTR_PORT,                  /* u16 */
+        FOU_ATTR_AF,                    /* u8 */
+        FOU_ATTR_IPPROTO,               /* u8 */
+        FOU_ATTR_TYPE,                  /* u8 */
+        FOU_ATTR_REMCSUM_NOPARTIAL,     /* flag */
+
+        __FOU_ATTR_MAX,
+};
+
+#define FOU_ATTR_MAX                (__FOU_ATTR_MAX - 1)
+
+enum {
+        FOU_CMD_UNSPEC,
+        FOU_CMD_ADD,
+        FOU_CMD_DEL,
+        FOU_CMD_GET,
+
+        __FOU_CMD_MAX,
+};
+
+enum {
+        FOU_ENCAP_UNSPEC,
+        FOU_ENCAP_DIRECT,
+        FOU_ENCAP_GUE,
+};
+
+#define FOU_CMD_MAX        (__FOU_CMD_MAX - 1)
+
+#else
+
+#if !HAVE_FOU_ATTR_REMCSUM_NOPARTIAL /* linux@fe881ef11cf0220f118816181930494d484c4883 (4.0) */
+#define FOU_ATTR_REMCSUM_NOPARTIAL 5
+
+#undef  FOU_ATTR_MAX
+#define FOU_ATTR_MAX               5
+#endif
+
+#if !HAVE_FOU_CMD_GET /* linux@7a6c8c34e5b71ac50e39588e20b39494a9e1d8e5 (4.1) */
+#define FOU_CMD_GET 3
+
+#undef  FOU_CMD_MAX
+#define FOU_CMD_MAX 3
+#endif
+
+#endif
diff --git a/src/basic/missing_fs.h b/src/basic/missing_fs.h
new file mode 100644
index 0000000..48c1af0
--- /dev/null
+++ b/src/basic/missing_fs.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/* linux/fs.h */
+#ifndef RENAME_NOREPLACE /* 0a7c3937a1f23f8cb5fc77ae01661e9968a51d0c (3.15) */
+#define RENAME_NOREPLACE (1 << 0)
+#endif
+
+/* linux/fs.h or sys/mount.h */
+#ifndef MS_MOVE
+#define MS_MOVE 8192
+#endif
+
+#ifndef MS_REC
+#define MS_REC 16384
+#endif
+
+#ifndef MS_PRIVATE
+#define MS_PRIVATE      (1<<18)
+#endif
+
+#ifndef MS_SLAVE
+#define MS_SLAVE        (1<<19)
+#endif
+
+#ifndef MS_SHARED
+#define MS_SHARED       (1<<20)
+#endif
+
+#ifndef MS_RELATIME
+#define MS_RELATIME     (1<<21)
+#endif
+
+#ifndef MS_KERNMOUNT
+#define MS_KERNMOUNT    (1<<22)
+#endif
+
+#ifndef MS_I_VERSION
+#define MS_I_VERSION    (1<<23)
+#endif
+
+#ifndef MS_STRICTATIME
+#define MS_STRICTATIME  (1<<24)
+#endif
+
+#ifndef MS_LAZYTIME
+#define MS_LAZYTIME     (1<<25)
+#endif
+
+/* Not exposed yet. Defined at fs/ext4/ext4.h */
+#ifndef EXT4_IOC_RESIZE_FS
+#define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
+#endif
+
+/* Not exposed yet. Defined at fs/cifs/cifsglob.h */
+#ifndef CIFS_MAGIC_NUMBER
+#define CIFS_MAGIC_NUMBER 0xFF534D42
+#endif
+
+/* linux/nsfs.h */
+#ifndef NS_GET_NSTYPE /* d95fa3c76a66b6d76b1e109ea505c55e66360f3c (4.11) */
+#define NS_GET_NSTYPE _IO(0xb7, 0x3)
+#endif
diff --git a/src/basic/missing_if_bridge.h b/src/basic/missing_if_bridge.h
new file mode 100644
index 0000000..9306062
--- /dev/null
+++ b/src/basic/missing_if_bridge.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#if !HAVE_IFLA_BRIDGE_VLAN_TUNNEL_INFO /* linux@b3c7ef0adadc5768e0baa786213c6bd1ce521a77 (4.11) */
+#define IFLA_BRIDGE_VLAN_TUNNEL_INFO 3
+
+#undef  IFLA_BRIDGE_MAX
+#define IFLA_BRIDGE_MAX              3
+#endif
+
+#ifndef BRIDGE_VLAN_INFO_RANGE_BEGIN
+#define BRIDGE_VLAN_INFO_RANGE_BEGIN (1<<3) /* VLAN is start of vlan range */
+#endif
+
+#ifndef BRIDGE_VLAN_INFO_RANGE_END
+#define BRIDGE_VLAN_INFO_RANGE_END   (1<<4) /* VLAN is end of vlan range */
+#endif
+
+#ifndef BRIDGE_VLAN_INFO_BRENTRY
+#define BRIDGE_VLAN_INFO_BRENTRY     (1<<5) /* Global bridge VLAN entry */
+#endif
diff --git a/src/basic/missing_if_link.h b/src/basic/missing_if_link.h
new file mode 100644
index 0000000..761797f
--- /dev/null
+++ b/src/basic/missing_if_link.h
@@ -0,0 +1,393 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#if !HAVE_IFLA_INET6_ADDR_GEN_MODE /* linux@bc91b0f07ada5535427373a4e2050877bcc12218 (3.17) */
+#define IFLA_INET6_ADDR_GEN_MODE 8
+
+#undef  IFLA_INET6_MAX
+#define IFLA_INET6_MAX           8
+
+enum in6_addr_gen_mode {
+        IN6_ADDR_GEN_MODE_EUI64,
+        IN6_ADDR_GEN_MODE_NONE,
+        IN6_ADDR_GEN_MODE_STABLE_PRIVACY,
+        IN6_ADDR_GEN_MODE_RANDOM,
+};
+#else
+#if !HAVE_IN6_ADDR_GEN_MODE_STABLE_PRIVACY /* linux@622c81d57b392cc9be836670eb464a4dfaa9adfe (4.1) */
+#define IN6_ADDR_GEN_MODE_STABLE_PRIVACY 2
+#endif
+#if !HAVE_IN6_ADDR_GEN_MODE_RANDOM /* linux@cc9da6cc4f56e05cc9e591459fe0192727ff58b3 (4.5) */
+#define IN6_ADDR_GEN_MODE_RANDOM         3
+#endif
+#endif /* !HAVE_IFLA_INET6_ADDR_GEN_MODE */
+
+#if !HAVE_IFLA_IPVLAN_MODE /* linux@2ad7bf3638411cb547f2823df08166c13ab04269 (3.19) */
+enum {
+        IFLA_IPVLAN_UNSPEC,
+        IFLA_IPVLAN_MODE,
+        IFLA_IPVLAN_FLAGS,
+        __IFLA_IPVLAN_MAX
+};
+#define IFLA_IPVLAN_MAX (__IFLA_IPVLAN_MAX - 1)
+enum ipvlan_mode {
+        IPVLAN_MODE_L2 = 0,
+        IPVLAN_MODE_L3,
+        IPVLAN_MODE_L3S,
+        IPVLAN_MODE_MAX
+};
+#else
+#if !HAVE_IPVLAN_MODE_L3S /* linux@4fbae7d83c98c30efcf0a2a2ac55fbb75ef5a1a5 (4.9) */
+#define IPVLAN_MODE_L3S   2
+#define IPVLAN_MODE_MAX   3
+#endif
+#if !HAVE_IFLA_IPVLAN_FLAGS /* linux@a190d04db93710ae166749055b6985397c6d13f5 (4.15) */
+#define IFLA_IPVLAN_FLAGS 2
+
+#undef  IFLA_IPVLAN_MAX
+#define IFLA_IPVLAN_MAX   2
+#endif
+#endif /* !HAVE_IFLA_IPVLAN_MODE */
+
+/* linux@a190d04db93710ae166749055b6985397c6d13f5 (4.15) */
+#ifndef IPVLAN_F_PRIVATE
+#define IPVLAN_F_PRIVATE 0x01
+#endif
+
+/* linux@fe89aa6b250c1011ccf425fbb7998e96bd54263f (4.15) */
+#ifndef IPVLAN_F_VEPA
+#define IPVLAN_F_VEPA    0x02
+#endif
+
+#if !HAVE_IFLA_PHYS_PORT_ID /* linux@66cae9ed6bc46b8cc57a9693f99f69926f3cc7ef (3.12) */
+#define IFLA_PHYS_PORT_ID       34
+#endif
+#if !HAVE_IFLA_CARRIER_CHANGES /* linux@2d3b479df41a10e2f41f9259fcba775bd34de6e4 (3.15) */
+#define IFLA_CARRIER_CHANGES    35
+#endif
+#if !HAVE_IFLA_PHYS_SWITCH_ID /* linux@82f2841291cfaf4d225aa1766424280254d3e3b2 (3.19) */
+#define IFLA_PHYS_SWITCH_ID     36
+#endif
+#if !HAVE_IFLA_LINK_NETNSID /* linux@d37512a277dfb2cef8a578e25a3246f61399a55a (4.0) */
+#define IFLA_LINK_NETNSID       37
+#endif
+#if !HAVE_IFLA_PHYS_PORT_NAME /* linux@db24a9044ee191c397dcd1c6574f56d67d7c8df5 (4.1) */
+#define IFLA_PHYS_PORT_NAME     38
+#endif
+#if !HAVE_IFLA_PROTO_DOWN /* linux@88d6378bd6c096cb8440face3ae3f33d55a2e6e4 (4.3) */
+#define IFLA_PROTO_DOWN         39
+#endif
+#if !HAVE_IFLA_GSO_MAX_SIZE /* linux@c70ce028e834f8e51306217dbdbd441d851c64d3 (4.6) */
+#define IFLA_GSO_MAX_SEGS       40
+#define IFLA_GSO_MAX_SIZE       41
+#endif
+#if !HAVE_IFLA_PAD /* linux@18402843bf88c2e9674e1a3a05c73b7d9b09ee05 (4.7) */
+#define IFLA_PAD                42
+#endif
+#if !HAVE_IFLA_XDP /* linux@d1fdd9138682e0f272beee0cb08b6328c5478b26 (4.8) */
+#define IFLA_XDP                43
+#endif
+#if !HAVE_IFLA_EVENT /* linux@3d3ea5af5c0b382bc9d9aed378fd814fb5d4a011 (4.13) */
+#define IFLA_EVENT              44
+#endif
+#if !HAVE_IFLA_IF_NETNSID /* linux@6621dd29eb9b5e6774ec7a9a75161352fdea47fc, 79e1ad148c844f5c8b9d76b36b26e3886dca95ae (4.15) */
+#define IFLA_IF_NETNSID         45
+#define IFLA_NEW_NETNSID        46
+#endif
+#if !HAVE_IFLA_TARGET_NETNSID /* linux@19d8f1ad12fd746e60707a58d954980013c7a35a (4.20) */
+#define IFLA_TARGET_NETNSID IFLA_IF_NETNSID
+#endif
+#if !HAVE_IFLA_NEW_IFINDEX /* linux@b2d3bcfa26a7a8de41f358a6cae8b848673b3c6e, 38e01b30563a5b5ade7b54e5d739d16a2b02fe82 (4.16) */
+#define IFLA_CARRIER_UP_COUNT   47
+#define IFLA_CARRIER_DOWN_COUNT 48
+#define IFLA_NEW_IFINDEX        49
+#endif
+#if !HAVE_IFLA_MAX_MTU /* linux@3e7a50ceb11ea75c27e944f1a01e478fd62a2d8d (4.19) */
+#define IFLA_MIN_MTU            50
+#define IFLA_MAX_MTU            51
+
+#undef  IFLA_MAX
+#define IFLA_MAX                51
+#endif
+
+#if !HAVE_IFLA_BOND_MODE /* linux@90af231106c0b8d223c27d35464af95cb3d9cacf (3.13) */
+#define IFLA_BOND_MODE              1
+#endif
+#if !HAVE_IFLA_BOND_ACTIVE_SLAVE /* linux@ec76aa49855f6d6fea5e01de179fb57dd47c619d (3.13) */
+#define IFLA_BOND_ACTIVE_SLAVE      2
+#endif
+#if !HAVE_IFLA_BOND_AD_INFO /* linux@4ee7ac7526d4a9413cafa733d824edfe49fdcc46 (3.14) */
+#define IFLA_BOND_MIIMON            3
+#define IFLA_BOND_UPDELAY           4
+#define IFLA_BOND_DOWNDELAY         5
+#define IFLA_BOND_USE_CARRIER       6
+#define IFLA_BOND_ARP_INTERVAL      7
+#define IFLA_BOND_ARP_IP_TARGET     8
+#define IFLA_BOND_ARP_VALIDATE      9
+#define IFLA_BOND_ARP_ALL_TARGETS   10
+#define IFLA_BOND_PRIMARY           11
+#define IFLA_BOND_PRIMARY_RESELECT  12
+#define IFLA_BOND_FAIL_OVER_MAC     13
+#define IFLA_BOND_XMIT_HASH_POLICY  14
+#define IFLA_BOND_RESEND_IGMP       15
+#define IFLA_BOND_NUM_PEER_NOTIF    16
+#define IFLA_BOND_ALL_SLAVES_ACTIVE 17
+#define IFLA_BOND_MIN_LINKS         18
+#define IFLA_BOND_LP_INTERVAL       19
+#define IFLA_BOND_PACKETS_PER_SLAVE 20
+#define IFLA_BOND_AD_LACP_RATE      21
+#define IFLA_BOND_AD_SELECT         22
+#define IFLA_BOND_AD_INFO           23
+#endif
+#if !HAVE_IFLA_BOND_AD_ACTOR_SYSTEM /* linux@171a42c38c6e1a5a076d6276e94e55a0b5b7868c (4.2) */
+#define IFLA_BOND_AD_ACTOR_SYS_PRIO 24
+#define IFLA_BOND_AD_USER_PORT_KEY  25
+#define IFLA_BOND_AD_ACTOR_SYSTEM   26
+#endif
+#if !HAVE_IFLA_BOND_TLB_DYNAMIC_LB /* linux@0f7bffd9e512b77279bbce704fad3cb1d6887958 (4.3) */
+#define IFLA_BOND_TLB_DYNAMIC_LB    27
+
+#undef  IFLA_BOND_MAX
+#define IFLA_BOND_MAX               27
+#endif
+
+#if !HAVE_IFLA_VXLAN_UDP_ZERO_CSUM6_RX /* linux@359a0ea9875ef4f32c8425bbe1ae348e1fd2ed2a (3.16) */
+#define IFLA_VXLAN_UDP_CSUM          18
+#define IFLA_VXLAN_UDP_ZERO_CSUM6_TX 19
+#define IFLA_VXLAN_UDP_ZERO_CSUM6_RX 20
+#endif
+#if !HAVE_IFLA_VXLAN_REMCSUM_NOPARTIAL /* linux@dfd8645ea1bd91277f841e74c33e1f4dbbede808..0ace2ca89cbd6bcdf2b9d2df1fa0fa24ea9d1653 (4.0) */
+#define IFLA_VXLAN_REMCSUM_TX        21
+#define IFLA_VXLAN_REMCSUM_RX        22
+#define IFLA_VXLAN_GBP               23
+#define IFLA_VXLAN_REMCSUM_NOPARTIAL 24
+#endif
+#if !HAVE_IFLA_VXLAN_COLLECT_METADATA /* linux@f8a9b1bc1b238eed9987da747a0e52f5bb009980 (4.3) */
+#define IFLA_VXLAN_COLLECT_METADATA  25
+#endif
+#if !HAVE_IFLA_VXLAN_LABEL /* linux@e7f70af111f086a20800ad2e17f544b2e3e0f375 (4.6) */
+#define IFLA_VXLAN_LABEL             26
+#endif
+#if !HAVE_IFLA_VXLAN_GPE /* linux@e1e5314de08ba6003b358125eafc9ad9e75a950c (4.7) */
+#define IFLA_VXLAN_GPE               27
+#endif
+#if !HAVE_IFLA_VXLAN_TTL_INHERIT /* linux@72f6d71e491e6ce269b564865b21fab0a4402dd3 (4.18) */
+#define IFLA_VXLAN_TTL_INHERIT       28
+
+#undef  IFLA_VXLAN_MAX
+#define IFLA_VXLAN_MAX               28
+#endif
+
+#if !HAVE_IFLA_GENEVE_TOS /* linux@2d07dc79fe04a43d82a346ced6bbf07bdb523f1b..d89511251f6519599b109dc6cda87a6ab314ed8c (4.2) */
+enum {
+        IFLA_GENEVE_UNSPEC,
+        IFLA_GENEVE_ID,
+        IFLA_GENEVE_REMOTE,
+        IFLA_GENEVE_TTL,
+        IFLA_GENEVE_TOS,
+        IFLA_GENEVE_PORT,        /* destination port */
+        IFLA_GENEVE_COLLECT_METADATA,
+        IFLA_GENEVE_REMOTE6,
+        IFLA_GENEVE_UDP_CSUM,
+        IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
+        IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
+        IFLA_GENEVE_LABEL,
+        IFLA_GENEVE_TTL_INHERIT,
+        __IFLA_GENEVE_MAX
+};
+#define IFLA_GENEVE_MAX        (__IFLA_GENEVE_MAX - 1)
+#else
+#if !HAVE_IFLA_GENEVE_COLLECT_METADATA /* linux@e305ac6cf5a1e1386aedce7ef9cb773635d5845c (4.3) */
+#define IFLA_GENEVE_PORT              5
+#define IFLA_GENEVE_COLLECT_METADATA  6
+#endif
+#if !HAVE_IFLA_GENEVE_REMOTE6 /* linux@8ed66f0e8235118a31720acdab3bbbe9debd0f6a (4.4) */
+#define IFLA_GENEVE_REMOTE6           7
+#endif
+#if !HAVE_IFLA_GENEVE_UDP_ZERO_CSUM6_RX /* linux@abe492b4f50c3ae2ebcfaa2f5c16176aebaa1c68 (4.5) */
+#define IFLA_GENEVE_UDP_CSUM          8
+#define IFLA_GENEVE_UDP_ZERO_CSUM6_TX 9
+#define IFLA_GENEVE_UDP_ZERO_CSUM6_RX 10
+#endif
+#if !HAVE_IFLA_GENEVE_LABEL /* linux@8eb3b99554b82da968d1fbc00df9f3156c5e2d63 (4.6) */
+#define IFLA_GENEVE_LABEL             11
+#endif
+#if !HAVE_IFLA_GENEVE_TTL_INHERIT /* linux@52d0d404d39dd9eac71a181615d6ca15e23d8e38 (4.20) */
+#define IFLA_GENEVE_TTL_INHERIT       12
+
+#undef  IFLA_GENEVE_MAX
+#define IFLA_GENEVE_MAX               12
+#endif
+#endif
+
+#if !HAVE_IFLA_BR_MAX_AGE /* linux@e5c3ea5c668033b303e7ac835d7d91da32d97958 (3.18) */
+enum {
+        IFLA_BR_UNSPEC,
+        IFLA_BR_FORWARD_DELAY,
+        IFLA_BR_HELLO_TIME,
+        IFLA_BR_MAX_AGE,
+        IFLA_BR_AGEING_TIME,
+        IFLA_BR_STP_STATE,
+        IFLA_BR_PRIORITY,
+        IFLA_BR_VLAN_FILTERING,
+        IFLA_BR_VLAN_PROTOCOL,
+        IFLA_BR_GROUP_FWD_MASK,
+        IFLA_BR_ROOT_ID,
+        IFLA_BR_BRIDGE_ID,
+        IFLA_BR_ROOT_PORT,
+        IFLA_BR_ROOT_PATH_COST,
+        IFLA_BR_TOPOLOGY_CHANGE,
+        IFLA_BR_TOPOLOGY_CHANGE_DETECTED,
+        IFLA_BR_HELLO_TIMER,
+        IFLA_BR_TCN_TIMER,
+        IFLA_BR_TOPOLOGY_CHANGE_TIMER,
+        IFLA_BR_GC_TIMER,
+        IFLA_BR_GROUP_ADDR,
+        IFLA_BR_FDB_FLUSH,
+        IFLA_BR_MCAST_ROUTER,
+        IFLA_BR_MCAST_SNOOPING,
+        IFLA_BR_MCAST_QUERY_USE_IFADDR,
+        IFLA_BR_MCAST_QUERIER,
+        IFLA_BR_MCAST_HASH_ELASTICITY,
+        IFLA_BR_MCAST_HASH_MAX,
+        IFLA_BR_MCAST_LAST_MEMBER_CNT,
+        IFLA_BR_MCAST_STARTUP_QUERY_CNT,
+        IFLA_BR_MCAST_LAST_MEMBER_INTVL,
+        IFLA_BR_MCAST_MEMBERSHIP_INTVL,
+        IFLA_BR_MCAST_QUERIER_INTVL,
+        IFLA_BR_MCAST_QUERY_INTVL,
+        IFLA_BR_MCAST_QUERY_RESPONSE_INTVL,
+        IFLA_BR_MCAST_STARTUP_QUERY_INTVL,
+        IFLA_BR_NF_CALL_IPTABLES,
+        IFLA_BR_NF_CALL_IP6TABLES,
+        IFLA_BR_NF_CALL_ARPTABLES,
+        IFLA_BR_VLAN_DEFAULT_PVID,
+        IFLA_BR_PAD,
+        IFLA_BR_VLAN_STATS_ENABLED,
+        IFLA_BR_MCAST_STATS_ENABLED,
+        IFLA_BR_MCAST_IGMP_VERSION,
+        IFLA_BR_MCAST_MLD_VERSION,
+        IFLA_BR_VLAN_STATS_PER_PORT,
+        __IFLA_BR_MAX,
+};
+
+#define IFLA_BR_MAX        (__IFLA_BR_MAX - 1)
+#else
+#if !HAVE_IFLA_BR_PRIORITY /* linux@af615762e972be0c66cf1d156ca4fac13b93c0b0 (4.1) */
+#define IFLA_BR_AGEING_TIME                4
+#define IFLA_BR_STP_STATE                  5
+#define IFLA_BR_PRIORITY                   6
+#endif
+#if !HAVE_IFLA_BR_VLAN_PROTOCOL /* linux@a7854037da006a7472c48773e3190db55217ec9b, d2d427b3927bd7a0348fc7f323d0e291f79a2779 (4.3) */
+#define IFLA_BR_VLAN_FILTERING             7
+#define IFLA_BR_VLAN_PROTOCOL              8
+#endif
+#if !HAVE_IFLA_BR_VLAN_DEFAULT_PVID /* linux@7910228b6bb35f3c8e0bc72a8d84c29616cb1b90..0f963b7592ef9e054974b6672b86ec1edd84b4bc (4.4) */
+#define IFLA_BR_GROUP_FWD_MASK             9
+#define IFLA_BR_ROOT_ID                    10
+#define IFLA_BR_BRIDGE_ID                  11
+#define IFLA_BR_ROOT_PORT                  12
+#define IFLA_BR_ROOT_PATH_COST             13
+#define IFLA_BR_TOPOLOGY_CHANGE            14
+#define IFLA_BR_TOPOLOGY_CHANGE_DETECTED   15
+#define IFLA_BR_HELLO_TIMER                16
+#define IFLA_BR_TCN_TIMER                  17
+#define IFLA_BR_TOPOLOGY_CHANGE_TIMER      18
+#define IFLA_BR_GC_TIMER                   19
+#define IFLA_BR_GROUP_ADDR                 20
+#define IFLA_BR_FDB_FLUSH                  21
+#define IFLA_BR_MCAST_ROUTER               22
+#define IFLA_BR_MCAST_SNOOPING             23
+#define IFLA_BR_MCAST_QUERY_USE_IFADDR     24
+#define IFLA_BR_MCAST_QUERIER              25
+#define IFLA_BR_MCAST_HASH_ELASTICITY      26
+#define IFLA_BR_MCAST_HASH_MAX             27
+#define IFLA_BR_MCAST_LAST_MEMBER_CNT      28
+#define IFLA_BR_MCAST_STARTUP_QUERY_CNT    29
+#define IFLA_BR_MCAST_LAST_MEMBER_INTVL    30
+#define IFLA_BR_MCAST_MEMBERSHIP_INTVL     31
+#define IFLA_BR_MCAST_QUERIER_INTVL        32
+#define IFLA_BR_MCAST_QUERY_INTVL          33
+#define IFLA_BR_MCAST_QUERY_RESPONSE_INTVL 34
+#define IFLA_BR_MCAST_STARTUP_QUERY_INTVL  35
+#define IFLA_BR_NF_CALL_IPTABLES           36
+#define IFLA_BR_NF_CALL_IP6TABLES          37
+#define IFLA_BR_NF_CALL_ARPTABLES          38
+#define IFLA_BR_VLAN_DEFAULT_PVID          39
+#endif
+#if !HAVE_IFLA_BR_VLAN_STATS_ENABLED /* linux@12a0faa3bd76157b9dc096758d6818ff535e4586, 6dada9b10a0818ba72c249526a742c8c41274a73 (4.7) */
+#define IFLA_BR_PAD                        40
+#define IFLA_BR_VLAN_STATS_ENABLED         41
+#endif
+#if !HAVE_IFLA_BR_MCAST_STATS_ENABLED /* linux@1080ab95e3c7bdd77870e209aff83c763fdcf439 (4.8) */
+#define IFLA_BR_MCAST_STATS_ENABLED        42
+#endif
+#if !HAVE_IFLA_BR_MCAST_MLD_VERSION /* linux@5e9235853d652a295d5f56cb8652950b6b5bf56b, aa2ae3e71c74cc00ec22f133dc900b3817415785 (4.10) */
+#define IFLA_BR_MCAST_IGMP_VERSION         43
+#define IFLA_BR_MCAST_MLD_VERSION          44
+#endif
+#if !HAVE_IFLA_BR_VLAN_STATS_PER_PORT /* linux@9163a0fc1f0c0980f117cc25f4fa6ba9b0750a36 (4.20) */
+#define IFLA_BR_VLAN_STATS_PER_PORT        45
+
+#undef  IFLA_BR_MAX
+#define IFLA_BR_MAX                        45
+#endif
+#endif
+
+#if !HAVE_IFLA_BRPORT_LEARNING_SYNC /* linux@958501163ddd6ea22a98f94fa0e7ce6d4734e5c4, efacacdaf7cb5a0592ed772e3731636b2742e34a (3.19)*/
+#define IFLA_BRPORT_PROXYARP            10
+#define IFLA_BRPORT_LEARNING_SYNC       11
+#endif
+#if !HAVE_IFLA_BRPORT_PROXYARP_WIFI /* linux@842a9ae08a25671db3d4f689eed68b4d64be15b5 (4.1) */
+#define IFLA_BRPORT_PROXYARP_WIFI       12
+#endif
+#if !HAVE_IFLA_BRPORT_MULTICAST_ROUTER /* linux@4ebc7660ab4559cad10b6595e05f70562bb26dc5..5d6ae479ab7ddf77bb22bdf739268581453ff886 (4.4) */
+#define IFLA_BRPORT_ROOT_ID             13
+#define IFLA_BRPORT_BRIDGE_ID           14
+#define IFLA_BRPORT_DESIGNATED_PORT     15
+#define IFLA_BRPORT_DESIGNATED_COST     16
+#define IFLA_BRPORT_ID                  17
+#define IFLA_BRPORT_NO                  18
+#define IFLA_BRPORT_TOPOLOGY_CHANGE_ACK 19
+#define IFLA_BRPORT_CONFIG_PENDING      20
+#define IFLA_BRPORT_MESSAGE_AGE_TIMER   21
+#define IFLA_BRPORT_FORWARD_DELAY_TIMER 22
+#define IFLA_BRPORT_HOLD_TIMER          23
+#define IFLA_BRPORT_FLUSH               24
+#define IFLA_BRPORT_MULTICAST_ROUTER    25
+#endif
+#if !HAVE_IFLA_BRPORT_PAD /* linux@12a0faa3bd76157b9dc096758d6818ff535e4586 (4.7) */
+#define IFLA_BRPORT_PAD                 26
+#endif
+#if !HAVE_IFLA_BRPORT_MCAST_FLOOD /* linux@b6cb5ac8331b6bcfe9ce38c7f7f58db6e1d6270a (4.9) */
+#define IFLA_BRPORT_MCAST_FLOOD         27
+#endif
+#if !HAVE_IFLA_BRPORT_VLAN_TUNNEL /* linux@6db6f0eae6052b70885562e1733896647ec1d807, b3c7ef0adadc5768e0baa786213c6bd1ce521a77 (4.11) */
+#define IFLA_BRPORT_MCAST_TO_UCAST      28
+#define IFLA_BRPORT_VLAN_TUNNEL         29
+#endif
+#if !HAVE_IFLA_BRPORT_BCAST_FLOOD /* linux@99f906e9ad7b6e79ffeda30f45906a8448b9d6a2 (4.12) */
+#define IFLA_BRPORT_BCAST_FLOOD         30
+#endif
+#if !HAVE_IFLA_BRPORT_NEIGH_SUPPRESS /* linux@5af48b59f35cf712793badabe1a574a0d0ce3bd3, 821f1b21cabb46827ce39ddf82e2789680b5042a (4.15) */
+#define IFLA_BRPORT_GROUP_FWD_MASK      31
+#define IFLA_BRPORT_NEIGH_SUPPRESS      32
+#endif
+#if !HAVE_IFLA_BRPORT_ISOLATED /* linux@7d850abd5f4edb1b1ca4b4141a4453305736f564 (4.18) */
+#define IFLA_BRPORT_ISOLATED            33
+#endif
+#if !HAVE_IFLA_BRPORT_BACKUP_PORT /* linux@2756f68c314917d03eb348084edb08bb929139d9 (4.19) */
+#define IFLA_BRPORT_BACKUP_PORT         34
+
+#undef  IFLA_BRPORT_MAX
+#define IFLA_BRPORT_MAX                 34
+#endif
+
+#if !HAVE_IFLA_VRF_TABLE /* linux@4e3c89920cd3a6cfce22c6f537690747c26128dd (4.3) */
+enum {
+        IFLA_VRF_UNSPEC,
+        IFLA_VRF_TABLE,
+        __IFLA_VRF_MAX
+};
+#define IFLA_VRF_MAX (__IFLA_VRF_MAX - 1)
+#endif
diff --git a/src/basic/missing_if_tunnel.h b/src/basic/missing_if_tunnel.h
new file mode 100644
index 0000000..f51fdd1
--- /dev/null
+++ b/src/basic/missing_if_tunnel.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#if !HAVE_IFLA_VTI_FWMARK /* linux@0a473b82cb23e7a35c4be6e9765c8487a65e8f55 (4.12) */
+#define IFLA_VTI_FWMARK 6
+
+#undef  IFLA_VTI_MAX
+#define IFLA_VTI_MAX    6
+#endif
+
+#if !HAVE_IFLA_IPTUN_ENCAP_DPORT /* linux@56328486539ddd07cbaafec7a542a2c8a3043623 (3.18)*/
+#define IFLA_IPTUN_ENCAP_TYPE       15
+#define IFLA_IPTUN_ENCAP_FLAGS      16
+#define IFLA_IPTUN_ENCAP_SPORT      17
+#define IFLA_IPTUN_ENCAP_DPORT      18
+#endif
+
+#if !HAVE_IFLA_IPTUN_COLLECT_METADATA /* linux@cfc7381b3002756b1dcada32979e942aa3126e31 (4.9) */
+#define IFLA_IPTUN_COLLECT_METADATA 19
+#endif
+
+#if !HAVE_IFLA_IPTUN_FWMARK /* linux@0a473b82cb23e7a35c4be6e9765c8487a65e8f55 (4.12) */
+#define IFLA_IPTUN_FWMARK           20
+
+#undef  IFLA_IPTUN_MAX
+#define IFLA_IPTUN_MAX              20
+#endif
+
+#if !HAVE_IFLA_GRE_ENCAP_DPORT /* linux@4565e9919cda747815547e2e5d7b78f15efbffdf (3.18) */
+#define IFLA_GRE_ENCAP_TYPE       14
+#define IFLA_GRE_ENCAP_FLAGS      15
+#define IFLA_GRE_ENCAP_SPORT      16
+#define IFLA_GRE_ENCAP_DPORT      17
+#endif
+
+#if !HAVE_IFLA_GRE_COLLECT_METADATA /* linux@2e15ea390e6f4466655066d97e22ec66870a042c (4.3) */
+#define IFLA_GRE_COLLECT_METADATA 18
+#endif
+
+#if !HAVE_IFLA_GRE_IGNORE_DF /* linux@22a59be8b7693eb2d0897a9638f5991f2f8e4ddd (4.8) */
+#define IFLA_GRE_IGNORE_DF        19
+#endif
+
+#if !HAVE_IFLA_GRE_FWMARK /* linux@0a473b82cb23e7a35c4be6e9765c8487a65e8f55 (4.12) */
+#define IFLA_GRE_FWMARK           20
+#endif
+
+#if !HAVE_IFLA_GRE_ERSPAN_INDEX /* linux@84e54fe0a5eaed696dee4019c396f8396f5a908b (4.14) */
+#define IFLA_GRE_ERSPAN_INDEX     21
+#endif
+
+#if !HAVE_IFLA_GRE_ERSPAN_HWID /* linux@f551c91de262ba36b20c3ac19538afb4f4507441 (4.16) */
+#define IFLA_GRE_ERSPAN_VER       22
+#define IFLA_GRE_ERSPAN_DIR       23
+#define IFLA_GRE_ERSPAN_HWID      24
+
+#undef  IFLA_GRE_MAX
+#define IFLA_GRE_MAX              24
+#endif
diff --git a/src/basic/missing_input.h b/src/basic/missing_input.h
new file mode 100644
index 0000000..b91ccb6
--- /dev/null
+++ b/src/basic/missing_input.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/input.h>
+#include <linux/types.h>
+
+/* linux@c7dc65737c9a607d3e6f8478659876074ad129b8 (3.12) */
+#ifndef EVIOCREVOKE
+#define EVIOCREVOKE _IOW('E', 0x91, int)
+#endif
+
+/* linux@06a16293f71927f756dcf37558a79c0b05a91641 (4.4) */
+#ifndef EVIOCSMASK
+struct input_mask {
+        __u32 type;
+        __u32 codes_size;
+        __u64 codes_ptr;
+};
+
+#define EVIOCGMASK _IOR('E', 0x92, struct input_mask)
+#define EVIOCSMASK _IOW('E', 0x93, struct input_mask)
+#endif
+
+/* linux@7611392fe8ff95ecae528b01a815ae3d72ca6b95 (3.17) */
+#ifndef INPUT_PROP_POINTING_STICK
+#define INPUT_PROP_POINTING_STICK 0x05
+#endif
+
+/* linux@500d4160abe9a2e88b12e319c13ae3ebd1e18108 (4.0) */
+#ifndef INPUT_PROP_ACCELEROMETER
+#define INPUT_PROP_ACCELEROMETER  0x06
+#endif
+
+/* linux@d09bbfd2a8408a995419dff0d2ba906013cf4cc9 (3.11) */
+#ifndef BTN_DPAD_UP
+#define BTN_DPAD_UP    0x220
+#define BTN_DPAD_DOWN  0x221
+#define BTN_DPAD_LEFT  0x222
+#define BTN_DPAD_RIGHT 0x223
+#endif
+
+/* linux@358f24704f2f016af7d504b357cdf32606091d07 (3.13) */
+#ifndef KEY_ALS_TOGGLE
+#define KEY_ALS_TOGGLE 0x230
+#endif
diff --git a/src/basic/missing_keyctl.h b/src/basic/missing_keyctl.h
new file mode 100644
index 0000000..7eb7095
--- /dev/null
+++ b/src/basic/missing_keyctl.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/keyctl.h>
+
+#ifndef KEYCTL_JOIN_SESSION_KEYRING
+#define KEYCTL_JOIN_SESSION_KEYRING 1
+#endif
+
+#ifndef KEYCTL_CHOWN
+#define KEYCTL_CHOWN 4
+#endif
+
+#ifndef KEYCTL_SETPERM
+#define KEYCTL_SETPERM 5
+#endif
+
+#ifndef KEYCTL_DESCRIBE
+#define KEYCTL_DESCRIBE 6
+#endif
+
+#ifndef KEYCTL_LINK
+#define KEYCTL_LINK 8
+#endif
+
+#ifndef KEYCTL_READ
+#define KEYCTL_READ 11
+#endif
+
+#ifndef KEYCTL_SET_TIMEOUT
+#define KEYCTL_SET_TIMEOUT 15
+#endif
+
+#ifndef KEY_SPEC_USER_KEYRING
+#define KEY_SPEC_USER_KEYRING -4
+#endif
+
+#ifndef KEY_SPEC_SESSION_KEYRING
+#define KEY_SPEC_SESSION_KEYRING -3
+#endif
+
+/* From linux/key.h */
+#ifndef KEY_POS_VIEW
+
+typedef int32_t key_serial_t;
+
+#define KEY_POS_VIEW    0x01000000
+#define KEY_POS_READ    0x02000000
+#define KEY_POS_WRITE   0x04000000
+#define KEY_POS_SEARCH  0x08000000
+#define KEY_POS_LINK    0x10000000
+#define KEY_POS_SETATTR 0x20000000
+#define KEY_POS_ALL     0x3f000000
+
+#define KEY_USR_VIEW    0x00010000
+#define KEY_USR_READ    0x00020000
+#define KEY_USR_WRITE   0x00040000
+#define KEY_USR_SEARCH  0x00080000
+#define KEY_USR_LINK    0x00100000
+#define KEY_USR_SETATTR 0x00200000
+#define KEY_USR_ALL     0x003f0000
+
+#define KEY_GRP_VIEW    0x00000100
+#define KEY_GRP_READ    0x00000200
+#define KEY_GRP_WRITE   0x00000400
+#define KEY_GRP_SEARCH  0x00000800
+#define KEY_GRP_LINK    0x00001000
+#define KEY_GRP_SETATTR 0x00002000
+#define KEY_GRP_ALL     0x00003f00
+
+#define KEY_OTH_VIEW    0x00000001
+#define KEY_OTH_READ    0x00000002
+#define KEY_OTH_WRITE   0x00000004
+#define KEY_OTH_SEARCH  0x00000008
+#define KEY_OTH_LINK    0x00000010
+#define KEY_OTH_SETATTR 0x00000020
+#define KEY_OTH_ALL     0x0000003f
+#endif
diff --git a/src/basic/missing_magic.h b/src/basic/missing_magic.h
new file mode 100644
index 0000000..4910cd3
--- /dev/null
+++ b/src/basic/missing_magic.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/magic.h>
+
+/* 62aa81d7c4c24b90fdb61da70ac0dbbc414f9939 (4.13) */
+#ifndef OCFS2_SUPER_MAGIC
+#define OCFS2_SUPER_MAGIC 0x7461636f
+#endif
+
+/* 67e9c74b8a873408c27ac9a8e4c1d1c8d72c93ff (4.5) */
+#ifndef CGROUP2_SUPER_MAGIC
+#define CGROUP2_SUPER_MAGIC 0x63677270
+#endif
+
+/* 4282d60689d4f21b40692029080440cc58e8a17d (4.1) */
+#ifndef TRACEFS_MAGIC
+#define TRACEFS_MAGIC 0x74726163
+#endif
+
+/* e149ed2b805fefdccf7ccdfc19eca22fdd4514ac (3.19) */
+#ifndef NSFS_MAGIC
+#define NSFS_MAGIC 0x6e736673
+#endif
+
+/* b2197755b2633e164a439682fb05a9b5ea48f706 (4.4) */
+#ifndef BPF_FS_MAGIC
+#define BPF_FS_MAGIC 0xcafe4a11
+#endif
+
+/* Not exposed yet (4.20). Defined at ipc/mqueue.c */
+#ifndef MQUEUE_MAGIC
+#define MQUEUE_MAGIC 0x19800202
+#endif
diff --git a/src/basic/missing_mman.h b/src/basic/missing_mman.h
new file mode 100644
index 0000000..7ff12f7
--- /dev/null
+++ b/src/basic/missing_mman.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/mman.h>
+
+#ifndef MFD_ALLOW_SEALING
+#define MFD_ALLOW_SEALING 0x0002U
+#endif
+
+#ifndef MFD_CLOEXEC
+#define MFD_CLOEXEC 0x0001U
+#endif
diff --git a/src/basic/missing_network.h b/src/basic/missing_network.h
new file mode 100644
index 0000000..59a8cd2
--- /dev/null
+++ b/src/basic/missing_network.h
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/loop.h>
+#include <linux/rtnetlink.h>
+#include <net/ethernet.h>
+
+#include "missing_ethtool.h"
+#include "missing_fib_rules.h"
+#include "missing_fou.h"
+#include "missing_if_bridge.h"
+#include "missing_if_link.h"
+#include "missing_if_tunnel.h"
+#include "missing_vxcan.h"
+
+/* if.h */
+/* The following two defines are actually available in the kernel headers for longer, but we define them here anyway,
+ * since that makes it easier to use them in conjunction with the glibc net/if.h header which conflicts with
+ * linux/if.h. */
+#ifndef IF_OPER_UNKNOWN
+#define IF_OPER_UNKNOWN 0
+#endif
+
+#ifndef IF_OPER_UP
+#define IF_OPER_UP 6
+#endif
+
+#ifndef IFF_LOWER_UP
+#define IFF_LOWER_UP 0x10000
+#endif
+
+#ifndef IFF_DORMANT
+#define IFF_DORMANT 0x20000
+#endif
+
+/* if_addr.h */
+#if !HAVE_IFA_FLAGS
+#define IFA_FLAGS 8
+#endif
+
+#ifndef IFA_F_MANAGETEMPADDR
+#define IFA_F_MANAGETEMPADDR 0x100
+#endif
+
+#ifndef IFA_F_NOPREFIXROUTE
+#define IFA_F_NOPREFIXROUTE 0x200
+#endif
+
+#ifndef IFA_F_MCAUTOJOIN
+#define IFA_F_MCAUTOJOIN 0x400
+#endif
+
+/* if_arp.h */
+#ifndef ARPHRD_IP6GRE
+#define ARPHRD_IP6GRE 823
+#endif
+
+/* if_bonding.h */
+#ifndef BOND_XMIT_POLICY_ENCAP23
+#define BOND_XMIT_POLICY_ENCAP23 3
+#endif
+
+#ifndef BOND_XMIT_POLICY_ENCAP34
+#define BOND_XMIT_POLICY_ENCAP34 4
+#endif
+
+/* if_tun.h */
+#ifndef IFF_MULTI_QUEUE
+#define IFF_MULTI_QUEUE 0x100
+#endif
+
+/* in6.h */
+#ifndef IPV6_UNICAST_IF
+#define IPV6_UNICAST_IF 76
+#endif
+
+/* ip.h */
+#ifndef IPV4_MIN_MTU
+#define IPV4_MIN_MTU 68
+#endif
+
+/* ipv6.h */
+#ifndef IPV6_MIN_MTU
+#define IPV6_MIN_MTU 1280
+#endif
+
+/* loop.h */
+#if !HAVE_LO_FLAGS_PARTSCAN
+#define LO_FLAGS_PARTSCAN 8
+#endif
+
+#ifndef LOOP_CTL_REMOVE
+#define LOOP_CTL_REMOVE 0x4C81
+#endif
+
+#ifndef LOOP_CTL_GET_FREE
+#define LOOP_CTL_GET_FREE 0x4C82
+#endif
+
+/* netdevice.h */
+#ifndef NET_ADDR_RANDOM
+#define NET_ADDR_RANDOM 1
+#endif
+
+#ifndef NET_NAME_UNKNOWN
+#define NET_NAME_UNKNOWN 0
+#endif
+
+#ifndef NET_NAME_ENUM
+#define NET_NAME_ENUM 1
+#endif
+
+#ifndef NET_NAME_PREDICTABLE
+#define NET_NAME_PREDICTABLE 2
+#endif
+
+#ifndef NET_NAME_USER
+#define NET_NAME_USER 3
+#endif
+
+#ifndef NET_NAME_RENAMED
+#define NET_NAME_RENAMED 4
+#endif
+
+/* netlink.h */
+#ifndef NETLINK_LIST_MEMBERSHIPS /* b42be38b2778eda2237fc759e55e3b698b05b315 (4.2) */
+#define NETLINK_LIST_MEMBERSHIPS 9
+#endif
+
+/* rtnetlink.h */
+#ifndef RTA_PREF
+#define RTA_PREF 20
+#endif
+
+#ifndef RTAX_QUICKACK
+#define RTAX_QUICKACK 15
+#endif
+
+#ifndef RTA_EXPIRES
+#define RTA_EXPIRES 23
+#endif
+
+/* Note that LOOPBACK_IFINDEX is currently not exported by the
+ * kernel/glibc, but hardcoded internally by the kernel.  However, as
+ * it is exported to userspace indirectly via rtnetlink and the
+ * ioctls, and made use of widely we define it here too, in a way that
+ * is compatible with the kernel's internal definition. */
+#ifndef LOOPBACK_IFINDEX
+#define LOOPBACK_IFINDEX 1
+#endif
+
+/* Not exposed yet. Similar values are defined in net/ethernet.h */
+#ifndef ETHERTYPE_LLDP
+#define ETHERTYPE_LLDP 0x88cc
+#endif
diff --git a/src/basic/missing_prctl.h b/src/basic/missing_prctl.h
new file mode 100644
index 0000000..f80cd17
--- /dev/null
+++ b/src/basic/missing_prctl.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/prctl.h>
+
+/* 58319057b7847667f0c9585b9de0e8932b0fdb08 (4.3) */
+#ifndef PR_CAP_AMBIENT
+#define PR_CAP_AMBIENT 47
+
+#define PR_CAP_AMBIENT_IS_SET    1
+#define PR_CAP_AMBIENT_RAISE     2
+#define PR_CAP_AMBIENT_LOWER     3
+#define PR_CAP_AMBIENT_CLEAR_ALL 4
+#endif
diff --git a/src/basic/missing_random.h b/src/basic/missing_random.h
new file mode 100644
index 0000000..2e76031
--- /dev/null
+++ b/src/basic/missing_random.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#if USE_SYS_RANDOM_H
+#  include <sys/random.h>
+#else
+#  include <linux/random.h>
+#endif
+
+#ifndef GRND_NONBLOCK
+#define GRND_NONBLOCK 0x0001
+#endif
+
+#ifndef GRND_RANDOM
+#define GRND_RANDOM 0x0002
+#endif
diff --git a/src/basic/missing_resource.h b/src/basic/missing_resource.h
new file mode 100644
index 0000000..22ba8ab
--- /dev/null
+++ b/src/basic/missing_resource.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/resource.h>
+
+#ifndef RLIMIT_RTTIME
+#define RLIMIT_RTTIME 15
+#endif
+
+/* If RLIMIT_RTTIME is not defined, then we cannot use RLIMIT_NLIMITS as is */
+#define _RLIMIT_MAX (RLIMIT_RTTIME+1 > RLIMIT_NLIMITS ? RLIMIT_RTTIME+1 : RLIMIT_NLIMITS)
diff --git a/src/basic/missing_sched.h b/src/basic/missing_sched.h
new file mode 100644
index 0000000..baa3913
--- /dev/null
+++ b/src/basic/missing_sched.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sched.h>
+
+#ifndef CLONE_NEWCGROUP
+#define CLONE_NEWCGROUP 0x02000000
+#endif
+
+/* Not exposed yet. Defined at include/linux/sched.h */
+#ifndef PF_KTHREAD
+#define PF_KTHREAD 0x00200000
+#endif
+
+/* The maximum thread/process name length including trailing NUL byte. This mimics the kernel definition of the same
+ * name, which we need in userspace at various places but is not defined in userspace currently, neither under this
+ * name nor any other. */
+/* Not exposed yet. Defined at include/linux/sched.h */
+#ifndef TASK_COMM_LEN
+#define TASK_COMM_LEN 16
+#endif
diff --git a/src/basic/missing_securebits.h b/src/basic/missing_securebits.h
new file mode 100644
index 0000000..40d6ec9
--- /dev/null
+++ b/src/basic/missing_securebits.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <linux/securebits.h>
+
+/* 746bf6d64275be0c65b0631d8a72b16f1454cfa1 (4.3) */
+#ifndef SECURE_NO_CAP_AMBIENT_RAISE
+#define SECURE_NO_CAP_AMBIENT_RAISE        6
+#define SECURE_NO_CAP_AMBIENT_RAISE_LOCKED 7  /* make bit-6 immutable */
+#define SECBIT_NO_CAP_AMBIENT_RAISE        (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE))
+#define SECBIT_NO_CAP_AMBIENT_RAISE_LOCKED (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE_LOCKED))
+
+#undef  SECURE_ALL_BITS
+#define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) |                 \
+                         issecure_mask(SECURE_NO_SETUID_FIXUP) |        \
+                         issecure_mask(SECURE_KEEP_CAPS) |              \
+                         issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE))
+#endif
diff --git a/src/basic/missing_socket.h b/src/basic/missing_socket.h
new file mode 100644
index 0000000..a5fd457
--- /dev/null
+++ b/src/basic/missing_socket.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/socket.h>
+
+#if HAVE_LINUX_VM_SOCKETS_H
+#include <linux/vm_sockets.h>
+#else
+#define VMADDR_CID_ANY -1U
+struct sockaddr_vm {
+        unsigned short svm_family;
+        unsigned short svm_reserved1;
+        unsigned int svm_port;
+        unsigned int svm_cid;
+        unsigned char svm_zero[sizeof(struct sockaddr) -
+                               sizeof(unsigned short) -
+                               sizeof(unsigned short) -
+                               sizeof(unsigned int) -
+                               sizeof(unsigned int)];
+};
+#endif /* !HAVE_LINUX_VM_SOCKETS_H */
+
+#ifndef AF_VSOCK
+#define AF_VSOCK 40
+#endif
+
+#ifndef SO_REUSEPORT
+#define SO_REUSEPORT 15
+#endif
+
+#ifndef SO_PEERGROUPS
+#define SO_PEERGROUPS 59
+#endif
+
+#ifndef SOL_NETLINK
+#define SOL_NETLINK 270
+#endif
+
+#ifndef SOL_ALG
+#define SOL_ALG 279
+#endif
+
+/* Not exposed yet. Defined in include/linux/socket.h. */
+#ifndef SOL_SCTP
+#define SOL_SCTP 132
+#endif
+
+/* Not exposed yet. Defined in include/linux/socket.h */
+#ifndef SCM_SECURITY
+#define SCM_SECURITY 0x03
+#endif
+
+/* netinet/in.h */
+#ifndef IP_FREEBIND
+#define IP_FREEBIND 15
+#endif
+
+#ifndef IP_TRANSPARENT
+#define IP_TRANSPARENT 19
+#endif
diff --git a/src/basic/missing_stat.h b/src/basic/missing_stat.h
new file mode 100644
index 0000000..5116206
--- /dev/null
+++ b/src/basic/missing_stat.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/types.h>
+#include <sys/stat.h>
+
+#if WANT_LINUX_STAT_H
+#include <linux/stat.h>
+#endif
+
+/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
+#if !HAVE_STRUCT_STATX
+struct statx_timestamp {
+        __s64 tv_sec;
+        __u32 tv_nsec;
+        __s32 __reserved;
+};
+struct statx {
+        __u32 stx_mask;
+        __u32 stx_blksize;
+        __u64 stx_attributes;
+        __u32 stx_nlink;
+        __u32 stx_uid;
+        __u32 stx_gid;
+        __u16 stx_mode;
+        __u16 __spare0[1];
+        __u64 stx_ino;
+        __u64 stx_size;
+        __u64 stx_blocks;
+        __u64 stx_attributes_mask;
+        struct statx_timestamp stx_atime;
+        struct statx_timestamp stx_btime;
+        struct statx_timestamp stx_ctime;
+        struct statx_timestamp stx_mtime;
+        __u32 stx_rdev_major;
+        __u32 stx_rdev_minor;
+        __u32 stx_dev_major;
+        __u32 stx_dev_minor;
+        __u64 __spare2[14];
+};
+#endif
+
+/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
+#ifndef STATX_BTIME
+#define STATX_BTIME 0x00000800U
+#endif
+
+/* a528d35e8bfcc521d7cb70aaf03e1bd296c8493f (4.11) */
+#ifndef AT_STATX_DONT_SYNC
+#define AT_STATX_DONT_SYNC 0x4000
+#endif
diff --git a/src/basic/missing_stdlib.h b/src/basic/missing_stdlib.h
new file mode 100644
index 0000000..188a8d4
--- /dev/null
+++ b/src/basic/missing_stdlib.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdlib.h>
+
+/* stdlib.h */
+#if !HAVE_SECURE_GETENV
+#  if HAVE___SECURE_GETENV
+#    define secure_getenv __secure_getenv
+#  else
+#    error "neither secure_getenv nor __secure_getenv are available"
+#  endif
+#endif
diff --git a/src/basic/missing_syscall.h b/src/basic/missing_syscall.h
new file mode 100644
index 0000000..d1aa322
--- /dev/null
+++ b/src/basic/missing_syscall.h
@@ -0,0 +1,446 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/* Missing glibc definitions to access certain kernel APIs */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#ifdef ARCH_MIPS
+#include <asm/sgidefs.h>
+#endif
+
+#include "missing_keyctl.h"
+#include "missing_stat.h"
+
+/* linux/kcmp.h */
+#ifndef KCMP_FILE /* 3f4994cfc15f38a3159c6e3a4b3ab2e1481a6b02 (3.19) */
+#define KCMP_FILE 0
+#endif
+
+#if !HAVE_PIVOT_ROOT
+static inline int missing_pivot_root(const char *new_root, const char *put_old) {
+        return syscall(__NR_pivot_root, new_root, put_old);
+}
+
+#  define pivot_root missing_pivot_root
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_MEMFD_CREATE
+#  ifndef __NR_memfd_create
+#    if defined __x86_64__
+#      define __NR_memfd_create 319
+#    elif defined __arm__
+#      define __NR_memfd_create 385
+#    elif defined __aarch64__
+#      define __NR_memfd_create 279
+#    elif defined __s390__
+#      define __NR_memfd_create 350
+#    elif defined _MIPS_SIM
+#      if _MIPS_SIM == _MIPS_SIM_ABI32
+#        define __NR_memfd_create 4354
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_NABI32
+#        define __NR_memfd_create 6318
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_ABI64
+#        define __NR_memfd_create 5314
+#      endif
+#    elif defined __i386__
+#      define __NR_memfd_create 356
+#    elif defined __arc__
+#      define __NR_memfd_create 279
+#    else
+#      warning "__NR_memfd_create unknown for your architecture"
+#    endif
+#  endif
+
+static inline int missing_memfd_create(const char *name, unsigned int flags) {
+#  ifdef __NR_memfd_create
+        return syscall(__NR_memfd_create, name, flags);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define memfd_create missing_memfd_create
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_GETRANDOM
+#  ifndef __NR_getrandom
+#    if defined __x86_64__
+#      define __NR_getrandom 318
+#    elif defined(__i386__)
+#      define __NR_getrandom 355
+#    elif defined(__arm__)
+#      define __NR_getrandom 384
+#   elif defined(__aarch64__)
+#      define __NR_getrandom 278
+#    elif defined(__ia64__)
+#      define __NR_getrandom 1339
+#    elif defined(__m68k__)
+#      define __NR_getrandom 352
+#    elif defined(__s390x__)
+#      define __NR_getrandom 349
+#    elif defined(__powerpc__)
+#      define __NR_getrandom 359
+#    elif defined _MIPS_SIM
+#      if _MIPS_SIM == _MIPS_SIM_ABI32
+#        define __NR_getrandom 4353
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_NABI32
+#        define __NR_getrandom 6317
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_ABI64
+#        define __NR_getrandom 5313
+#      endif
+#    elif defined(__arc__)
+#      define __NR_getrandom 278
+#    else
+#      warning "__NR_getrandom unknown for your architecture"
+#    endif
+#  endif
+
+static inline int missing_getrandom(void *buffer, size_t count, unsigned flags) {
+#  ifdef __NR_getrandom
+        return syscall(__NR_getrandom, buffer, count, flags);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define getrandom missing_getrandom
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_GETTID
+static inline pid_t missing_gettid(void) {
+        return (pid_t) syscall(__NR_gettid);
+}
+
+#  define gettid missing_gettid
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_NAME_TO_HANDLE_AT
+#  ifndef __NR_name_to_handle_at
+#    if defined(__x86_64__)
+#      define __NR_name_to_handle_at 303
+#    elif defined(__i386__)
+#      define __NR_name_to_handle_at 341
+#    elif defined(__arm__)
+#      define __NR_name_to_handle_at 370
+#    elif defined(__powerpc__)
+#      define __NR_name_to_handle_at 345
+#    elif defined(__arc__)
+#      define __NR_name_to_handle_at 264
+#    else
+#      error "__NR_name_to_handle_at is not defined"
+#    endif
+#  endif
+
+struct file_handle {
+        unsigned int handle_bytes;
+        int handle_type;
+        unsigned char f_handle[0];
+};
+
+static inline int missing_name_to_handle_at(int fd, const char *name, struct file_handle *handle, int *mnt_id, int flags) {
+#  ifdef __NR_name_to_handle_at
+        return syscall(__NR_name_to_handle_at, fd, name, handle, mnt_id, flags);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define name_to_handle_at missing_name_to_handle_at
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_SETNS
+#  ifndef __NR_setns
+#    if defined(__x86_64__)
+#      define __NR_setns 308
+#    elif defined(__i386__)
+#      define __NR_setns 346
+#    elif defined(__arc__)
+#      define __NR_setns 268
+#    else
+#      error "__NR_setns is not defined"
+#    endif
+#  endif
+
+static inline int missing_setns(int fd, int nstype) {
+#  ifdef __NR_setns
+        return syscall(__NR_setns, fd, nstype);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define setns missing_setns
+#endif
+
+/* ======================================================================= */
+
+static inline pid_t raw_getpid(void) {
+#if defined(__alpha__)
+        return (pid_t) syscall(__NR_getxpid);
+#else
+        return (pid_t) syscall(__NR_getpid);
+#endif
+}
+
+/* ======================================================================= */
+
+#if !HAVE_RENAMEAT2
+#  ifndef __NR_renameat2
+#    if defined __x86_64__
+#      define __NR_renameat2 316
+#    elif defined __arm__
+#      define __NR_renameat2 382
+#    elif defined __aarch64__
+#      define __NR_renameat2 276
+#    elif defined _MIPS_SIM
+#      if _MIPS_SIM == _MIPS_SIM_ABI32
+#        define __NR_renameat2 4351
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_NABI32
+#        define __NR_renameat2 6315
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_ABI64
+#        define __NR_renameat2 5311
+#      endif
+#    elif defined __i386__
+#      define __NR_renameat2 353
+#    elif defined __powerpc64__
+#      define __NR_renameat2 357
+#    elif defined __s390__ || defined __s390x__
+#      define __NR_renameat2 347
+#    elif defined __arc__
+#      define __NR_renameat2 276
+#    else
+#      warning "__NR_renameat2 unknown for your architecture"
+#    endif
+#  endif
+
+static inline int missing_renameat2(int oldfd, const char *oldname, int newfd, const char *newname, unsigned flags) {
+#  ifdef __NR_renameat2
+        return syscall(__NR_renameat2, oldfd, oldname, newfd, newname, flags);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define renameat2 missing_renameat2
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_KCMP
+static inline int missing_kcmp(pid_t pid1, pid_t pid2, int type, unsigned long idx1, unsigned long idx2) {
+#  ifdef __NR_kcmp
+        return syscall(__NR_kcmp, pid1, pid2, type, idx1, idx2);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define kcmp missing_kcmp
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_KEYCTL
+static inline long missing_keyctl(int cmd, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) {
+#  ifdef __NR_keyctl
+        return syscall(__NR_keyctl, cmd, arg2, arg3, arg4, arg5);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+
+#  define keyctl missing_keyctl
+}
+
+static inline key_serial_t missing_add_key(const char *type, const char *description, const void *payload, size_t plen, key_serial_t ringid) {
+#  ifdef __NR_add_key
+        return syscall(__NR_add_key, type, description, payload, plen, ringid);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+
+#  define add_key missing_add_key
+}
+
+static inline key_serial_t missing_request_key(const char *type, const char *description, const char * callout_info, key_serial_t destringid) {
+#  ifdef __NR_request_key
+        return syscall(__NR_request_key, type, description, callout_info, destringid);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+
+#  define request_key missing_request_key
+}
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_COPY_FILE_RANGE
+#  ifndef __NR_copy_file_range
+#    if defined(__x86_64__)
+#      define __NR_copy_file_range 326
+#    elif defined(__i386__)
+#      define __NR_copy_file_range 377
+#    elif defined __s390__
+#      define __NR_copy_file_range 375
+#    elif defined __arm__
+#      define __NR_copy_file_range 391
+#    elif defined __aarch64__
+#      define __NR_copy_file_range 285
+#    elif defined __powerpc__
+#      define __NR_copy_file_range 379
+#    elif defined __arc__
+#      define __NR_copy_file_range 285
+#    else
+#      warning "__NR_copy_file_range not defined for your architecture"
+#    endif
+#  endif
+
+static inline ssize_t missing_copy_file_range(int fd_in, loff_t *off_in,
+                                              int fd_out, loff_t *off_out,
+                                              size_t len,
+                                              unsigned int flags) {
+#  ifdef __NR_copy_file_range
+        return syscall(__NR_copy_file_range, fd_in, off_in, fd_out, off_out, len, flags);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define copy_file_range missing_copy_file_range
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_BPF
+#  ifndef __NR_bpf
+#    if defined __i386__
+#      define __NR_bpf 357
+#    elif defined __x86_64__
+#      define __NR_bpf 321
+#    elif defined __aarch64__
+#      define __NR_bpf 280
+#    elif defined __arm__
+#      define __NR_bpf 386
+#    elif defined __sparc__
+#      define __NR_bpf 349
+#    elif defined __s390__
+#      define __NR_bpf 351
+#    elif defined __tilegx__
+#      define __NR_bpf 280
+#    else
+#      warning "__NR_bpf not defined for your architecture"
+#    endif
+#  endif
+
+union bpf_attr;
+
+static inline int missing_bpf(int cmd, union bpf_attr *attr, size_t size) {
+#ifdef __NR_bpf
+        return (int) syscall(__NR_bpf, cmd, attr, size);
+#else
+        errno = ENOSYS;
+        return -1;
+#endif
+}
+
+#  define bpf missing_bpf
+#endif
+
+/* ======================================================================= */
+
+#ifndef __IGNORE_pkey_mprotect
+#  ifndef __NR_pkey_mprotect
+#    if defined __i386__
+#      define __NR_pkey_mprotect 380
+#    elif defined __x86_64__
+#      define __NR_pkey_mprotect 329
+#    elif defined __arm__
+#      define __NR_pkey_mprotect 394
+#    elif defined __aarch64__
+#      define __NR_pkey_mprotect 394
+#    elif defined __powerpc__
+#      define __NR_pkey_mprotect 386
+#    elif defined _MIPS_SIM
+#      if _MIPS_SIM == _MIPS_SIM_ABI32
+#        define __NR_pkey_mprotect 4363
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_NABI32
+#        define __NR_pkey_mprotect 6327
+#      endif
+#      if _MIPS_SIM == _MIPS_SIM_ABI64
+#        define __NR_pkey_mprotect 5323
+#      endif
+#    else
+#      warning "__NR_pkey_mprotect not defined for your architecture"
+#    endif
+#  endif
+#endif
+
+/* ======================================================================= */
+
+#if !HAVE_STATX
+#  ifndef __NR_statx
+#    if defined __aarch64__ || defined __arm__
+#      define __NR_statx 397
+#    elif defined __alpha__
+#      define __NR_statx 522
+#    elif defined __i386__ || defined __powerpc64__
+#      define __NR_statx 383
+#    elif defined __sparc__
+#      define __NR_statx 360
+#    elif defined __x86_64__
+#      define __NR_statx 332
+#    else
+#      warning "__NR_statx not defined for your architecture"
+#    endif
+#  endif
+
+struct statx;
+#endif
+
+/* This typedef is supposed to be always defined. */
+typedef struct statx struct_statx;
+
+#if !HAVE_STATX
+static inline ssize_t missing_statx(int dfd, const char *filename, unsigned flags, unsigned int mask, struct statx *buffer) {
+#  ifdef __NR_statx
+        return syscall(__NR_statx, dfd, filename, flags, mask, buffer);
+#  else
+        errno = ENOSYS;
+        return -1;
+#  endif
+}
+
+#  define statx missing_statx
+#endif
diff --git a/src/basic/missing_timerfd.h b/src/basic/missing_timerfd.h
new file mode 100644
index 0000000..6b04044
--- /dev/null
+++ b/src/basic/missing_timerfd.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/timerfd.h>
+
+#ifndef TFD_TIMER_CANCEL_ON_SET
+#define TFD_TIMER_CANCEL_ON_SET (1 << 1)
+#endif
diff --git a/src/basic/missing_type.h b/src/basic/missing_type.h
new file mode 100644
index 0000000..bf8a6ca
--- /dev/null
+++ b/src/basic/missing_type.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <uchar.h>
+
+#if !HAVE_CHAR32_T
+#define char32_t uint32_t
+#endif
+
+#if !HAVE_CHAR16_T
+#define char16_t uint16_t
+#endif
diff --git a/src/basic/missing_vxcan.h b/src/basic/missing_vxcan.h
new file mode 100644
index 0000000..be430f7
--- /dev/null
+++ b/src/basic/missing_vxcan.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#if !HAVE_LINUX_CAN_VXCAN_H /* linux@a8f820a380a2a06fc4fe1a54159067958f800929 (4.12) */
+enum {
+        VXCAN_INFO_UNSPEC,
+        VXCAN_INFO_PEER,
+
+        __VXCAN_INFO_MAX
+#define VXCAN_INFO_MAX        (__VXCAN_INFO_MAX - 1)
+};
+#endif
diff --git a/src/basic/mkdir-label.c b/src/basic/mkdir-label.c
new file mode 100644
index 0000000..0eba7fc
--- /dev/null
+++ b/src/basic/mkdir-label.c
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "label.h"
+#include "macro.h"
+#include "mkdir.h"
+#include "selinux-util.h"
+#include "smack-util.h"
+
+int mkdir_label(const char *path, mode_t mode) {
+        int r;
+
+        assert(path);
+
+        r = mac_selinux_create_file_prepare(path, S_IFDIR);
+        if (r < 0)
+                return r;
+
+        r = mkdir_errno_wrapper(path, mode);
+        mac_selinux_create_file_clear();
+        if (r < 0)
+                return r;
+
+        return mac_smack_fix(path, 0);
+}
+
+int mkdirat_label(int dirfd, const char *path, mode_t mode) {
+        int r;
+
+        assert(path);
+
+        r = mac_selinux_create_file_prepare_at(dirfd, path, S_IFDIR);
+        if (r < 0)
+                return r;
+
+        r = mkdirat_errno_wrapper(dirfd, path, mode);
+        mac_selinux_create_file_clear();
+        if (r < 0)
+                return r;
+
+        return mac_smack_fix_at(dirfd, path, 0);
+}
+
+int mkdir_safe_label(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) {
+        return mkdir_safe_internal(path, mode, uid, gid, flags, mkdir_label);
+}
+
+int mkdir_parents_label(const char *path, mode_t mode) {
+        return mkdir_parents_internal(NULL, path, mode, mkdir_label);
+}
+
+int mkdir_p_label(const char *path, mode_t mode) {
+        return mkdir_p_internal(NULL, path, mode, mkdir_label);
+}
diff --git a/src/basic/mkdir.c b/src/basic/mkdir.c
new file mode 100644
index 0000000..4bb65d5
--- /dev/null
+++ b/src/basic/mkdir.c
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include "alloc-util.h"
+#include "fs-util.h"
+#include "macro.h"
+#include "mkdir.h"
+#include "path-util.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "user-util.h"
+
+int mkdir_safe_internal(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags, mkdir_func_t _mkdir) {
+        struct stat st;
+        int r;
+
+        assert(_mkdir != mkdir);
+
+        if (_mkdir(path, mode) >= 0) {
+                r = chmod_and_chown(path, mode, uid, gid);
+                if (r < 0)
+                        return r;
+        }
+
+        if (lstat(path, &st) < 0)
+                return -errno;
+
+        if ((flags & MKDIR_FOLLOW_SYMLINK) && S_ISLNK(st.st_mode)) {
+                _cleanup_free_ char *p = NULL;
+
+                r = chase_symlinks(path, NULL, CHASE_NONEXISTENT, &p);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return mkdir_safe_internal(p, mode, uid, gid,
+                                                   flags & ~MKDIR_FOLLOW_SYMLINK,
+                                                   _mkdir);
+
+                if (lstat(p, &st) < 0)
+                        return -errno;
+        }
+
+        if (!S_ISDIR(st.st_mode)) {
+                log_full(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG,
+                         "Path \"%s\" already exists and is not a directory, refusing.", path);
+                return -ENOTDIR;
+        }
+        if ((st.st_mode & 0007) > (mode & 0007) ||
+            (st.st_mode & 0070) > (mode & 0070) ||
+            (st.st_mode & 0700) > (mode & 0700)) {
+                log_full(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG,
+                         "Directory \"%s\" already exists, but has mode %04o that is too permissive (%04o was requested), refusing.",
+                         path, st.st_mode & 0777, mode);
+                return -EEXIST;
+        }
+        if ((uid != UID_INVALID && st.st_uid != uid) ||
+            (gid != GID_INVALID && st.st_gid != gid)) {
+                char u[DECIMAL_STR_MAX(uid_t)] = "-", g[DECIMAL_STR_MAX(gid_t)] = "-";
+
+                if (uid != UID_INVALID)
+                        xsprintf(u, UID_FMT, uid);
+                if (gid != UID_INVALID)
+                        xsprintf(g, GID_FMT, gid);
+                log_full(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG,
+                         "Directory \"%s\" already exists, but is owned by "UID_FMT":"GID_FMT" (%s:%s was requested), refusing.",
+                         path, st.st_uid, st.st_gid, u, g);
+                return -EEXIST;
+        }
+
+        return 0;
+}
+
+int mkdir_errno_wrapper(const char *pathname, mode_t mode) {
+        if (mkdir(pathname, mode) < 0)
+                return -errno;
+        return 0;
+}
+
+int mkdirat_errno_wrapper(int dirfd, const char *pathname, mode_t mode) {
+        if (mkdirat(dirfd, pathname, mode) < 0)
+                return -errno;
+        return 0;
+}
+
+int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) {
+        return mkdir_safe_internal(path, mode, uid, gid, flags, mkdir_errno_wrapper);
+}
+
+int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
+        const char *p, *e;
+        int r;
+
+        assert(path);
+        assert(_mkdir != mkdir);
+
+        if (prefix && !path_startswith(path, prefix))
+                return -ENOTDIR;
+
+        /* return immediately if directory exists */
+        e = strrchr(path, '/');
+        if (!e)
+                return -EINVAL;
+
+        if (e == path)
+                return 0;
+
+        p = strndupa(path, e - path);
+        r = is_dir(p, true);
+        if (r > 0)
+                return 0;
+        if (r == 0)
+                return -ENOTDIR;
+
+        /* create every parent directory in the path, except the last component */
+        p = path + strspn(path, "/");
+        for (;;) {
+                char t[strlen(path) + 1];
+
+                e = p + strcspn(p, "/");
+                p = e + strspn(e, "/");
+
+                /* Is this the last component? If so, then we're done */
+                if (*p == 0)
+                        return 0;
+
+                memcpy(t, path, e - path);
+                t[e-path] = 0;
+
+                if (prefix && path_startswith(prefix, t))
+                        continue;
+
+                r = _mkdir(t, mode);
+                if (r < 0 && r != -EEXIST)
+                        return r;
+        }
+}
+
+int mkdir_parents(const char *path, mode_t mode) {
+        return mkdir_parents_internal(NULL, path, mode, mkdir_errno_wrapper);
+}
+
+int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
+        int r;
+
+        /* Like mkdir -p */
+
+        assert(_mkdir != mkdir);
+
+        r = mkdir_parents_internal(prefix, path, mode, _mkdir);
+        if (r < 0)
+                return r;
+
+        r = _mkdir(path, mode);
+        if (r < 0 && (r != -EEXIST || is_dir(path, true) <= 0))
+                return r;
+
+        return 0;
+}
+
+int mkdir_p(const char *path, mode_t mode) {
+        return mkdir_p_internal(NULL, path, mode, mkdir_errno_wrapper);
+}
diff --git a/src/basic/mkdir.h b/src/basic/mkdir.h
new file mode 100644
index 0000000..eb54853
--- /dev/null
+++ b/src/basic/mkdir.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/types.h>
+
+typedef enum MkdirFlags {
+        MKDIR_FOLLOW_SYMLINK = 1 << 0,
+        MKDIR_WARN_MODE      = 1 << 1,
+} MkdirFlags;
+
+int mkdir_errno_wrapper(const char *pathname, mode_t mode);
+int mkdirat_errno_wrapper(int dirfd, const char *pathname, mode_t mode);
+int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags);
+int mkdir_parents(const char *path, mode_t mode);
+int mkdir_p(const char *path, mode_t mode);
+
+/* mandatory access control(MAC) versions */
+int mkdir_safe_label(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags);
+int mkdir_parents_label(const char *path, mode_t mode);
+int mkdir_p_label(const char *path, mode_t mode);
+
+/* internally used */
+typedef int (*mkdir_func_t)(const char *pathname, mode_t mode);
+int mkdir_safe_internal(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags, mkdir_func_t _mkdir);
+int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir);
+int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir);
diff --git a/src/basic/mountpoint-util.c b/src/basic/mountpoint-util.c
new file mode 100644
index 0000000..1e946a0
--- /dev/null
+++ b/src/basic/mountpoint-util.c
@@ -0,0 +1,444 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio_ext.h>
+#include <sys/mount.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "missing.h"
+#include "mountpoint-util.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "stdio-util.h"
+#include "strv.h"
+
+/* This is the original MAX_HANDLE_SZ definition from the kernel, when the API was introduced. We use that in place of
+ * any more currently defined value to future-proof things: if the size is increased in the API headers, and our code
+ * is recompiled then it would cease working on old kernels, as those refuse any sizes larger than this value with
+ * EINVAL right-away. Hence, let's disconnect ourselves from any such API changes, and stick to the original definition
+ * from when it was introduced. We use it as a start value only anyway (see below), and hence should be able to deal
+ * with large file handles anyway. */
+#define ORIGINAL_MAX_HANDLE_SZ 128
+
+int name_to_handle_at_loop(
+                int fd,
+                const char *path,
+                struct file_handle **ret_handle,
+                int *ret_mnt_id,
+                int flags) {
+
+        _cleanup_free_ struct file_handle *h = NULL;
+        size_t n = ORIGINAL_MAX_HANDLE_SZ;
+
+        /* We need to invoke name_to_handle_at() in a loop, given that it might return EOVERFLOW when the specified
+         * buffer is too small. Note that in contrast to what the docs might suggest, MAX_HANDLE_SZ is only good as a
+         * start value, it is not an upper bound on the buffer size required.
+         *
+         * This improves on raw name_to_handle_at() also in one other regard: ret_handle and ret_mnt_id can be passed
+         * as NULL if there's no interest in either. */
+
+        for (;;) {
+                int mnt_id = -1;
+
+                h = malloc0(offsetof(struct file_handle, f_handle) + n);
+                if (!h)
+                        return -ENOMEM;
+
+                h->handle_bytes = n;
+
+                if (name_to_handle_at(fd, path, h, &mnt_id, flags) >= 0) {
+
+                        if (ret_handle)
+                                *ret_handle = TAKE_PTR(h);
+
+                        if (ret_mnt_id)
+                                *ret_mnt_id = mnt_id;
+
+                        return 0;
+                }
+                if (errno != EOVERFLOW)
+                        return -errno;
+
+                if (!ret_handle && ret_mnt_id && mnt_id >= 0) {
+
+                        /* As it appears, name_to_handle_at() fills in mnt_id even when it returns EOVERFLOW when the
+                         * buffer is too small, but that's undocumented. Hence, let's make use of this if it appears to
+                         * be filled in, and the caller was interested in only the mount ID an nothing else. */
+
+                        *ret_mnt_id = mnt_id;
+                        return 0;
+                }
+
+                /* If name_to_handle_at() didn't increase the byte size, then this EOVERFLOW is caused by something
+                 * else (apparently EOVERFLOW is returned for untriggered nfs4 mounts sometimes), not by the too small
+                 * buffer. In that case propagate EOVERFLOW */
+                if (h->handle_bytes <= n)
+                        return -EOVERFLOW;
+
+                /* The buffer was too small. Size the new buffer by what name_to_handle_at() returned. */
+                n = h->handle_bytes;
+                if (offsetof(struct file_handle, f_handle) + n < n) /* check for addition overflow */
+                        return -EOVERFLOW;
+
+                h = mfree(h);
+        }
+}
+
+static int fd_fdinfo_mnt_id(int fd, const char *filename, int flags, int *mnt_id) {
+        char path[STRLEN("/proc/self/fdinfo/") + DECIMAL_STR_MAX(int)];
+        _cleanup_free_ char *fdinfo = NULL;
+        _cleanup_close_ int subfd = -1;
+        char *p;
+        int r;
+
+        if ((flags & AT_EMPTY_PATH) && isempty(filename))
+                xsprintf(path, "/proc/self/fdinfo/%i", fd);
+        else {
+                subfd = openat(fd, filename, O_CLOEXEC|O_PATH|(flags & AT_SYMLINK_FOLLOW ? 0 : O_NOFOLLOW));
+                if (subfd < 0)
+                        return -errno;
+
+                xsprintf(path, "/proc/self/fdinfo/%i", subfd);
+        }
+
+        r = read_full_file(path, &fdinfo, NULL);
+        if (r == -ENOENT) /* The fdinfo directory is a relatively new addition */
+                return -EOPNOTSUPP;
+        if (r < 0)
+                return r;
+
+        p = startswith(fdinfo, "mnt_id:");
+        if (!p) {
+                p = strstr(fdinfo, "\nmnt_id:");
+                if (!p) /* The mnt_id field is a relatively new addition */
+                        return -EOPNOTSUPP;
+
+                p += 8;
+        }
+
+        p += strspn(p, WHITESPACE);
+        p[strcspn(p, WHITESPACE)] = 0;
+
+        return safe_atoi(p, mnt_id);
+}
+
+int fd_is_mount_point(int fd, const char *filename, int flags) {
+        _cleanup_free_ struct file_handle *h = NULL, *h_parent = NULL;
+        int mount_id = -1, mount_id_parent = -1;
+        bool nosupp = false, check_st_dev = true;
+        struct stat a, b;
+        int r;
+
+        assert(fd >= 0);
+        assert(filename);
+
+        /* First we will try the name_to_handle_at() syscall, which
+         * tells us the mount id and an opaque file "handle". It is
+         * not supported everywhere though (kernel compile-time
+         * option, not all file systems are hooked up). If it works
+         * the mount id is usually good enough to tell us whether
+         * something is a mount point.
+         *
+         * If that didn't work we will try to read the mount id from
+         * /proc/self/fdinfo/<fd>. This is almost as good as
+         * name_to_handle_at(), however, does not return the
+         * opaque file handle. The opaque file handle is pretty useful
+         * to detect the root directory, which we should always
+         * consider a mount point. Hence we use this only as
+         * fallback. Exporting the mnt_id in fdinfo is a pretty recent
+         * kernel addition.
+         *
+         * As last fallback we do traditional fstat() based st_dev
+         * comparisons. This is how things were traditionally done,
+         * but unionfs breaks this since it exposes file
+         * systems with a variety of st_dev reported. Also, btrfs
+         * subvolumes have different st_dev, even though they aren't
+         * real mounts of their own. */
+
+        r = name_to_handle_at_loop(fd, filename, &h, &mount_id, flags);
+        if (IN_SET(r, -ENOSYS, -EACCES, -EPERM, -EOVERFLOW, -EINVAL))
+                /* This kernel does not support name_to_handle_at() at all (ENOSYS), or the syscall was blocked
+                 * (EACCES/EPERM; maybe through seccomp, because we are running inside of a container?), or the mount
+                 * point is not triggered yet (EOVERFLOW, think nfs4), or some general name_to_handle_at() flakiness
+                 * (EINVAL): fall back to simpler logic. */
+                goto fallback_fdinfo;
+        else if (r == -EOPNOTSUPP)
+                /* This kernel or file system does not support name_to_handle_at(), hence let's see if the upper fs
+                 * supports it (in which case it is a mount point), otherwise fallback to the traditional stat()
+                 * logic */
+                nosupp = true;
+        else if (r < 0)
+                return r;
+
+        r = name_to_handle_at_loop(fd, "", &h_parent, &mount_id_parent, AT_EMPTY_PATH);
+        if (r == -EOPNOTSUPP) {
+                if (nosupp)
+                        /* Neither parent nor child do name_to_handle_at()?  We have no choice but to fall back. */
+                        goto fallback_fdinfo;
+                else
+                        /* The parent can't do name_to_handle_at() but the directory we are interested in can?  If so,
+                         * it must be a mount point. */
+                        return 1;
+        } else if (r < 0)
+                return r;
+
+        /* The parent can do name_to_handle_at() but the
+         * directory we are interested in can't? If so, it
+         * must be a mount point. */
+        if (nosupp)
+                return 1;
+
+        /* If the file handle for the directory we are
+         * interested in and its parent are identical, we
+         * assume this is the root directory, which is a mount
+         * point. */
+
+        if (h->handle_bytes == h_parent->handle_bytes &&
+            h->handle_type == h_parent->handle_type &&
+            memcmp(h->f_handle, h_parent->f_handle, h->handle_bytes) == 0)
+                return 1;
+
+        return mount_id != mount_id_parent;
+
+fallback_fdinfo:
+        r = fd_fdinfo_mnt_id(fd, filename, flags, &mount_id);
+        if (IN_SET(r, -EOPNOTSUPP, -EACCES, -EPERM))
+                goto fallback_fstat;
+        if (r < 0)
+                return r;
+
+        r = fd_fdinfo_mnt_id(fd, "", AT_EMPTY_PATH, &mount_id_parent);
+        if (r < 0)
+                return r;
+
+        if (mount_id != mount_id_parent)
+                return 1;
+
+        /* Hmm, so, the mount ids are the same. This leaves one
+         * special case though for the root file system. For that,
+         * let's see if the parent directory has the same inode as we
+         * are interested in. Hence, let's also do fstat() checks now,
+         * too, but avoid the st_dev comparisons, since they aren't
+         * that useful on unionfs mounts. */
+        check_st_dev = false;
+
+fallback_fstat:
+        /* yay for fstatat() taking a different set of flags than the other
+         * _at() above */
+        if (flags & AT_SYMLINK_FOLLOW)
+                flags &= ~AT_SYMLINK_FOLLOW;
+        else
+                flags |= AT_SYMLINK_NOFOLLOW;
+        if (fstatat(fd, filename, &a, flags) < 0)
+                return -errno;
+
+        if (fstatat(fd, "", &b, AT_EMPTY_PATH) < 0)
+                return -errno;
+
+        /* A directory with same device and inode as its parent? Must
+         * be the root directory */
+        if (a.st_dev == b.st_dev &&
+            a.st_ino == b.st_ino)
+                return 1;
+
+        return check_st_dev && (a.st_dev != b.st_dev);
+}
+
+/* flags can be AT_SYMLINK_FOLLOW or 0 */
+int path_is_mount_point(const char *t, const char *root, int flags) {
+        _cleanup_free_ char *canonical = NULL;
+        _cleanup_close_ int fd = -1;
+        int r;
+
+        assert(t);
+        assert((flags & ~AT_SYMLINK_FOLLOW) == 0);
+
+        if (path_equal(t, "/"))
+                return 1;
+
+        /* we need to resolve symlinks manually, we can't just rely on
+         * fd_is_mount_point() to do that for us; if we have a structure like
+         * /bin -> /usr/bin/ and /usr is a mount point, then the parent that we
+         * look at needs to be /usr, not /. */
+        if (flags & AT_SYMLINK_FOLLOW) {
+                r = chase_symlinks(t, root, CHASE_TRAIL_SLASH, &canonical);
+                if (r < 0)
+                        return r;
+
+                t = canonical;
+        }
+
+        fd = open_parent(t, O_PATH|O_CLOEXEC, 0);
+        if (fd < 0)
+                return -errno;
+
+        return fd_is_mount_point(fd, last_path_component(t), flags);
+}
+
+int path_get_mnt_id(const char *path, int *ret) {
+        int r;
+
+        r = name_to_handle_at_loop(AT_FDCWD, path, NULL, ret, 0);
+        if (IN_SET(r, -EOPNOTSUPP, -ENOSYS, -EACCES, -EPERM, -EOVERFLOW, -EINVAL)) /* kernel/fs don't support this, or seccomp blocks access, or untriggered mount, or name_to_handle_at() is flaky */
+                return fd_fdinfo_mnt_id(AT_FDCWD, path, 0, ret);
+
+        return r;
+}
+
+bool fstype_is_network(const char *fstype) {
+        const char *x;
+
+        x = startswith(fstype, "fuse.");
+        if (x)
+                fstype = x;
+
+        return STR_IN_SET(fstype,
+                          "afs",
+                          "cifs",
+                          "smbfs",
+                          "sshfs",
+                          "ncpfs",
+                          "ncp",
+                          "nfs",
+                          "nfs4",
+                          "gfs",
+                          "gfs2",
+                          "glusterfs",
+                          "pvfs2", /* OrangeFS */
+                          "ocfs2",
+                          "lustre");
+}
+
+bool fstype_is_api_vfs(const char *fstype) {
+        return STR_IN_SET(fstype,
+                          "autofs",
+                          "bpf",
+                          "cgroup",
+                          "cgroup2",
+                          "configfs",
+                          "cpuset",
+                          "debugfs",
+                          "devpts",
+                          "devtmpfs",
+                          "efivarfs",
+                          "fusectl",
+                          "hugetlbfs",
+                          "mqueue",
+                          "proc",
+                          "pstore",
+                          "ramfs",
+                          "securityfs",
+                          "sysfs",
+                          "tmpfs",
+                          "tracefs");
+}
+
+bool fstype_is_ro(const char *fstype) {
+        /* All Linux file systems that are necessarily read-only */
+        return STR_IN_SET(fstype,
+                          "DM_verity_hash",
+                          "iso9660",
+                          "squashfs");
+}
+
+bool fstype_can_discard(const char *fstype) {
+        return STR_IN_SET(fstype,
+                          "btrfs",
+                          "ext4",
+                          "vfat",
+                          "xfs");
+}
+
+bool fstype_can_uid_gid(const char *fstype) {
+
+        /* All file systems that have a uid=/gid= mount option that fixates the owners of all files and directories,
+         * current and future. */
+
+        return STR_IN_SET(fstype,
+                          "adfs",
+                          "fat",
+                          "hfs",
+                          "hpfs",
+                          "iso9660",
+                          "msdos",
+                          "ntfs",
+                          "vfat");
+}
+
+int dev_is_devtmpfs(void) {
+        _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
+        int mount_id, r;
+        char *e;
+
+        r = path_get_mnt_id("/dev", &mount_id);
+        if (r < 0)
+                return r;
+
+        proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
+        if (!proc_self_mountinfo)
+                return -errno;
+
+        (void) __fsetlocking(proc_self_mountinfo, FSETLOCKING_BYCALLER);
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                int mid;
+
+                r = read_line(proc_self_mountinfo, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (sscanf(line, "%i", &mid) != 1)
+                        continue;
+
+                if (mid != mount_id)
+                        continue;
+
+                e = strstr(line, " - ");
+                if (!e)
+                        continue;
+
+                /* accept any name that starts with the currently expected type */
+                if (startswith(e + 3, "devtmpfs"))
+                        return true;
+        }
+
+        return false;
+}
+
+const char *mount_propagation_flags_to_string(unsigned long flags) {
+
+        switch (flags & (MS_SHARED|MS_SLAVE|MS_PRIVATE)) {
+        case 0:
+                return "";
+        case MS_SHARED:
+                return "shared";
+        case MS_SLAVE:
+                return "slave";
+        case MS_PRIVATE:
+                return "private";
+        }
+
+        return NULL;
+}
+
+int mount_propagation_flags_from_string(const char *name, unsigned long *ret) {
+
+        if (isempty(name))
+                *ret = 0;
+        else if (streq(name, "shared"))
+                *ret = MS_SHARED;
+        else if (streq(name, "slave"))
+                *ret = MS_SLAVE;
+        else if (streq(name, "private"))
+                *ret = MS_PRIVATE;
+        else
+                return -EINVAL;
+        return 0;
+}
diff --git a/src/basic/mountpoint-util.h b/src/basic/mountpoint-util.h
new file mode 100644
index 0000000..5398836
--- /dev/null
+++ b/src/basic/mountpoint-util.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <fcntl.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+int name_to_handle_at_loop(int fd, const char *path, struct file_handle **ret_handle, int *ret_mnt_id, int flags);
+
+int path_get_mnt_id(const char *path, int *ret);
+
+int fd_is_mount_point(int fd, const char *filename, int flags);
+int path_is_mount_point(const char *path, const char *root, int flags);
+
+bool fstype_is_network(const char *fstype);
+bool fstype_is_api_vfs(const char *fstype);
+bool fstype_is_ro(const char *fsype);
+bool fstype_can_discard(const char *fstype);
+bool fstype_can_uid_gid(const char *fstype);
+
+int dev_is_devtmpfs(void);
+
+const char *mount_propagation_flags_to_string(unsigned long flags);
+int mount_propagation_flags_from_string(const char *name, unsigned long *ret);
diff --git a/src/basic/nss-util.h b/src/basic/nss-util.h
new file mode 100644
index 0000000..2045175
--- /dev/null
+++ b/src/basic/nss-util.h
@@ -0,0 +1,183 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <grp.h>
+#include <netdb.h>
+#include <nss.h>
+#include <pwd.h>
+#include <resolv.h>
+
+#define NSS_SIGNALS_BLOCK SIGALRM,SIGVTALRM,SIGPIPE,SIGCHLD,SIGTSTP,SIGIO,SIGHUP,SIGUSR1,SIGUSR2,SIGPROF,SIGURG,SIGWINCH
+
+#ifndef DEPRECATED_RES_USE_INET6
+#  define DEPRECATED_RES_USE_INET6 0x00002000
+#endif
+
+#define NSS_GETHOSTBYNAME_PROTOTYPES(module)            \
+enum nss_status _nss_##module##_gethostbyname4_r(       \
+                const char *name,                       \
+                struct gaih_addrtuple **pat,            \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop,             \
+                int32_t *ttlp) _public_;                \
+enum nss_status _nss_##module##_gethostbyname3_r(       \
+                const char *name,                       \
+                int af,                                 \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop,             \
+                int32_t *ttlp,                          \
+                char **canonp) _public_;                \
+enum nss_status _nss_##module##_gethostbyname2_r(       \
+                const char *name,                       \
+                int af,                                 \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop) _public_;   \
+enum nss_status _nss_##module##_gethostbyname_r(        \
+                const char *name,                       \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop) _public_
+
+#define NSS_GETHOSTBYADDR_PROTOTYPES(module)            \
+enum nss_status _nss_##module##_gethostbyaddr2_r(       \
+                const void* addr, socklen_t len,        \
+                int af,                                 \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop,             \
+                int32_t *ttlp) _public_;                \
+enum nss_status _nss_##module##_gethostbyaddr_r(        \
+                const void* addr, socklen_t len,        \
+                int af,                                 \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop) _public_
+
+#define NSS_GETHOSTBYNAME_FALLBACKS(module)             \
+enum nss_status _nss_##module##_gethostbyname2_r(       \
+                const char *name,                       \
+                int af,                                 \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop) {           \
+        return _nss_##module##_gethostbyname3_r(        \
+                        name,                           \
+                        af,                             \
+                        host,                           \
+                        buffer, buflen,                 \
+                        errnop, h_errnop,               \
+                        NULL,                           \
+                        NULL);                          \
+}                                                       \
+enum nss_status _nss_##module##_gethostbyname_r(        \
+                const char *name,                       \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop) {           \
+        enum nss_status ret = NSS_STATUS_NOTFOUND;      \
+                                                        \
+        if (_res.options & DEPRECATED_RES_USE_INET6)    \
+                ret = _nss_##module##_gethostbyname3_r( \
+                        name,                           \
+                        AF_INET6,                       \
+                        host,                           \
+                        buffer, buflen,                 \
+                        errnop, h_errnop,               \
+                        NULL,                           \
+                        NULL);                          \
+        if (ret == NSS_STATUS_NOTFOUND)                 \
+                ret = _nss_##module##_gethostbyname3_r( \
+                        name,                           \
+                        AF_INET,                        \
+                        host,                           \
+                        buffer, buflen,                 \
+                        errnop, h_errnop,               \
+                        NULL,                           \
+                        NULL);                          \
+       return ret;                                      \
+}
+
+#define NSS_GETHOSTBYADDR_FALLBACKS(module)             \
+enum nss_status _nss_##module##_gethostbyaddr_r(        \
+                const void* addr, socklen_t len,        \
+                int af,                                 \
+                struct hostent *host,                   \
+                char *buffer, size_t buflen,            \
+                int *errnop, int *h_errnop) {           \
+        return _nss_##module##_gethostbyaddr2_r(        \
+                        addr, len,                      \
+                        af,                             \
+                        host,                           \
+                        buffer, buflen,                 \
+                        errnop, h_errnop,               \
+                        NULL);                          \
+}
+
+#define NSS_GETPW_PROTOTYPES(module)                    \
+enum nss_status _nss_##module##_getpwnam_r(             \
+                const char *name,                       \
+                struct passwd *pwd,                     \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_;                  \
+enum nss_status _nss_##module##_getpwuid_r(             \
+                uid_t uid,                              \
+                struct passwd *pwd,                     \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_
+
+#define NSS_GETGR_PROTOTYPES(module)                    \
+enum nss_status _nss_##module##_getgrnam_r(             \
+                const char *name,                       \
+                struct group *gr,                       \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_;                  \
+enum nss_status _nss_##module##_getgrgid_r(             \
+                gid_t gid,                              \
+                struct group *gr,                       \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_
+
+typedef enum nss_status (*_nss_gethostbyname4_r_t)(
+                const char *name,
+                struct gaih_addrtuple **pat,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp);
+
+typedef enum nss_status (*_nss_gethostbyname3_r_t)(
+                const char *name,
+                int af,
+                struct hostent *result,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp,
+                char **canonp);
+
+typedef enum nss_status (*_nss_gethostbyname2_r_t)(
+                const char *name,
+                int af,
+                struct hostent *result,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop);
+
+typedef enum nss_status (*_nss_gethostbyname_r_t)(
+                const char *name,
+                struct hostent *result,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop);
+
+typedef enum nss_status (*_nss_gethostbyaddr2_r_t)(
+                const void* addr, socklen_t len,
+                int af,
+                struct hostent *result,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop,
+                int32_t *ttlp);
+typedef enum nss_status (*_nss_gethostbyaddr_r_t)(
+                const void* addr, socklen_t len,
+                int af,
+                struct hostent *host,
+                char *buffer, size_t buflen,
+                int *errnop, int *h_errnop);
diff --git a/src/basic/ordered-set.c b/src/basic/ordered-set.c
new file mode 100644
index 0000000..ed9ba77
--- /dev/null
+++ b/src/basic/ordered-set.c
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "ordered-set.h"
+#include "strv.h"
+
+int ordered_set_consume(OrderedSet *s, void *p) {
+        int r;
+
+        r = ordered_set_put(s, p);
+        if (r <= 0)
+                free(p);
+
+        return r;
+}
+
+int ordered_set_put_strdup(OrderedSet *s, const char *p) {
+        char *c;
+        int r;
+
+        assert(s);
+        assert(p);
+
+        c = strdup(p);
+        if (!c)
+                return -ENOMEM;
+
+        r = ordered_set_consume(s, c);
+        if (r == -EEXIST)
+                return 0;
+
+        return r;
+}
+
+int ordered_set_put_strdupv(OrderedSet *s, char **l) {
+        int n = 0, r;
+        char **i;
+
+        STRV_FOREACH(i, l) {
+                r = ordered_set_put_strdup(s, *i);
+                if (r < 0)
+                        return r;
+
+                n += r;
+        }
+
+        return n;
+}
diff --git a/src/basic/ordered-set.h b/src/basic/ordered-set.h
new file mode 100644
index 0000000..7cbb718
--- /dev/null
+++ b/src/basic/ordered-set.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "hashmap.h"
+
+typedef struct OrderedSet OrderedSet;
+
+static inline OrderedSet* ordered_set_new(const struct hash_ops *ops) {
+        return (OrderedSet*) ordered_hashmap_new(ops);
+}
+
+static inline int ordered_set_ensure_allocated(OrderedSet **s, const struct hash_ops *ops) {
+        if (*s)
+                return 0;
+
+        *s = ordered_set_new(ops);
+        if (!*s)
+                return -ENOMEM;
+
+        return 0;
+}
+
+static inline OrderedSet* ordered_set_free(OrderedSet *s) {
+        return (OrderedSet*) ordered_hashmap_free((OrderedHashmap*) s);
+}
+
+static inline OrderedSet* ordered_set_free_free(OrderedSet *s) {
+        return (OrderedSet*) ordered_hashmap_free_free((OrderedHashmap*) s);
+}
+
+static inline int ordered_set_put(OrderedSet *s, void *p) {
+        return ordered_hashmap_put((OrderedHashmap*) s, p, p);
+}
+
+static inline bool ordered_set_isempty(OrderedSet *s) {
+        return ordered_hashmap_isempty((OrderedHashmap*) s);
+}
+
+static inline bool ordered_set_iterate(OrderedSet *s, Iterator *i, void **value) {
+        return ordered_hashmap_iterate((OrderedHashmap*) s, i, value, NULL);
+}
+
+static inline void* ordered_set_remove(OrderedSet *s, void *p) {
+        return ordered_hashmap_remove((OrderedHashmap*) s, p);
+}
+
+static inline void* ordered_set_steal_first(OrderedSet *s) {
+        return ordered_hashmap_steal_first((OrderedHashmap*) s);
+}
+
+int ordered_set_consume(OrderedSet *s, void *p);
+int ordered_set_put_strdup(OrderedSet *s, const char *p);
+int ordered_set_put_strdupv(OrderedSet *s, char **l);
+
+#define ORDERED_SET_FOREACH(e, s, i)                                    \
+        for ((i) = ITERATOR_FIRST; ordered_set_iterate((s), &(i), (void**)&(e)); )
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedSet*, ordered_set_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedSet*, ordered_set_free_free);
+
+#define _cleanup_ordered_set_free_ _cleanup_(ordered_set_freep)
+#define _cleanup_ordered_set_free_free_ _cleanup_(ordered_set_free_freep)
diff --git a/src/basic/parse-util.c b/src/basic/parse-util.c
new file mode 100644
index 0000000..87724af
--- /dev/null
+++ b/src/basic/parse-util.c
@@ -0,0 +1,779 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/oom.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+
+#include "alloc-util.h"
+#include "errno-list.h"
+#include "extract-word.h"
+#include "locale-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "process-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+
+int parse_boolean(const char *v) {
+        if (!v)
+                return -EINVAL;
+
+        if (streq(v, "1") || strcaseeq(v, "yes") || strcaseeq(v, "y") || strcaseeq(v, "true") || strcaseeq(v, "t") || strcaseeq(v, "on"))
+                return 1;
+        else if (streq(v, "0") || strcaseeq(v, "no") || strcaseeq(v, "n") || strcaseeq(v, "false") || strcaseeq(v, "f") || strcaseeq(v, "off"))
+                return 0;
+
+        return -EINVAL;
+}
+
+int parse_pid(const char *s, pid_t* ret_pid) {
+        unsigned long ul = 0;
+        pid_t pid;
+        int r;
+
+        assert(s);
+        assert(ret_pid);
+
+        r = safe_atolu(s, &ul);
+        if (r < 0)
+                return r;
+
+        pid = (pid_t) ul;
+
+        if ((unsigned long) pid != ul)
+                return -ERANGE;
+
+        if (!pid_is_valid(pid))
+                return -ERANGE;
+
+        *ret_pid = pid;
+        return 0;
+}
+
+int parse_mode(const char *s, mode_t *ret) {
+        char *x;
+        long l;
+
+        assert(s);
+        assert(ret);
+
+        s += strspn(s, WHITESPACE);
+        if (s[0] == '-')
+                return -ERANGE;
+
+        errno = 0;
+        l = strtol(s, &x, 8);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+        if (l < 0 || l  > 07777)
+                return -ERANGE;
+
+        *ret = (mode_t) l;
+        return 0;
+}
+
+int parse_ifindex(const char *s, int *ret) {
+        int ifi, r;
+
+        r = safe_atoi(s, &ifi);
+        if (r < 0)
+                return r;
+        if (ifi <= 0)
+                return -EINVAL;
+
+        *ret = ifi;
+        return 0;
+}
+
+int parse_mtu(int family, const char *s, uint32_t *ret) {
+        uint64_t u;
+        size_t m;
+        int r;
+
+        r = parse_size(s, 1024, &u);
+        if (r < 0)
+                return r;
+
+        if (u > UINT32_MAX)
+                return -ERANGE;
+
+        if (family == AF_INET6)
+                m = IPV6_MIN_MTU; /* This is 1280 */
+        else
+                m = IPV4_MIN_MTU; /* For all other protocols, including 'unspecified' we assume the IPv4 minimal MTU */
+
+        if (u < m)
+                return -ERANGE;
+
+        *ret = (uint32_t) u;
+        return 0;
+}
+
+int parse_size(const char *t, uint64_t base, uint64_t *size) {
+
+        /* Soo, sometimes we want to parse IEC binary suffixes, and
+         * sometimes SI decimal suffixes. This function can parse
+         * both. Which one is the right way depends on the
+         * context. Wikipedia suggests that SI is customary for
+         * hardware metrics and network speeds, while IEC is
+         * customary for most data sizes used by software and volatile
+         * (RAM) memory. Hence be careful which one you pick!
+         *
+         * In either case we use just K, M, G as suffix, and not Ki,
+         * Mi, Gi or so (as IEC would suggest). That's because that's
+         * frickin' ugly. But this means you really need to make sure
+         * to document which base you are parsing when you use this
+         * call. */
+
+        struct table {
+                const char *suffix;
+                unsigned long long factor;
+        };
+
+        static const struct table iec[] = {
+                { "E", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
+                { "P", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
+                { "T", 1024ULL*1024ULL*1024ULL*1024ULL },
+                { "G", 1024ULL*1024ULL*1024ULL },
+                { "M", 1024ULL*1024ULL },
+                { "K", 1024ULL },
+                { "B", 1ULL },
+                { "",  1ULL },
+        };
+
+        static const struct table si[] = {
+                { "E", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "P", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "T", 1000ULL*1000ULL*1000ULL*1000ULL },
+                { "G", 1000ULL*1000ULL*1000ULL },
+                { "M", 1000ULL*1000ULL },
+                { "K", 1000ULL },
+                { "B", 1ULL },
+                { "",  1ULL },
+        };
+
+        const struct table *table;
+        const char *p;
+        unsigned long long r = 0;
+        unsigned n_entries, start_pos = 0;
+
+        assert(t);
+        assert(IN_SET(base, 1000, 1024));
+        assert(size);
+
+        if (base == 1000) {
+                table = si;
+                n_entries = ELEMENTSOF(si);
+        } else {
+                table = iec;
+                n_entries = ELEMENTSOF(iec);
+        }
+
+        p = t;
+        do {
+                unsigned long long l, tmp;
+                double frac = 0;
+                char *e;
+                unsigned i;
+
+                p += strspn(p, WHITESPACE);
+
+                errno = 0;
+                l = strtoull(p, &e, 10);
+                if (errno > 0)
+                        return -errno;
+                if (e == p)
+                        return -EINVAL;
+                if (*p == '-')
+                        return -ERANGE;
+
+                if (*e == '.') {
+                        e++;
+
+                        /* strtoull() itself would accept space/+/- */
+                        if (*e >= '0' && *e <= '9') {
+                                unsigned long long l2;
+                                char *e2;
+
+                                l2 = strtoull(e, &e2, 10);
+                                if (errno > 0)
+                                        return -errno;
+
+                                /* Ignore failure. E.g. 10.M is valid */
+                                frac = l2;
+                                for (; e < e2; e++)
+                                        frac /= 10;
+                        }
+                }
+
+                e += strspn(e, WHITESPACE);
+
+                for (i = start_pos; i < n_entries; i++)
+                        if (startswith(e, table[i].suffix))
+                                break;
+
+                if (i >= n_entries)
+                        return -EINVAL;
+
+                if (l + (frac > 0) > ULLONG_MAX / table[i].factor)
+                        return -ERANGE;
+
+                tmp = l * table[i].factor + (unsigned long long) (frac * table[i].factor);
+                if (tmp > ULLONG_MAX - r)
+                        return -ERANGE;
+
+                r += tmp;
+                if ((unsigned long long) (uint64_t) r != r)
+                        return -ERANGE;
+
+                p = e + strlen(table[i].suffix);
+
+                start_pos = i + 1;
+
+        } while (*p);
+
+        *size = r;
+
+        return 0;
+}
+
+int parse_range(const char *t, unsigned *lower, unsigned *upper) {
+        _cleanup_free_ char *word = NULL;
+        unsigned l, u;
+        int r;
+
+        assert(lower);
+        assert(upper);
+
+        /* Extract the lower bound. */
+        r = extract_first_word(&t, &word, "-", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -EINVAL;
+
+        r = safe_atou(word, &l);
+        if (r < 0)
+                return r;
+
+        /* Check for the upper bound and extract it if needed */
+        if (!t)
+                /* Single number with no dashes. */
+                u = l;
+        else if (!*t)
+                /* Trailing dash is an error. */
+                return -EINVAL;
+        else {
+                r = safe_atou(t, &u);
+                if (r < 0)
+                        return r;
+        }
+
+        *lower = l;
+        *upper = u;
+        return 0;
+}
+
+int parse_errno(const char *t) {
+        int r, e;
+
+        assert(t);
+
+        r = errno_from_name(t);
+        if (r > 0)
+                return r;
+
+        r = safe_atoi(t, &e);
+        if (r < 0)
+                return r;
+
+        /* 0 is also allowed here */
+        if (!errno_is_valid(e) && e != 0)
+                return -ERANGE;
+
+        return e;
+}
+
+int parse_syscall_and_errno(const char *in, char **name, int *error) {
+        _cleanup_free_ char *n = NULL;
+        char *p;
+        int e = -1;
+
+        assert(in);
+        assert(name);
+        assert(error);
+
+        /*
+         * This parse "syscall:errno" like "uname:EILSEQ", "@sync:255".
+         * If errno is omitted, then error is set to -1.
+         * Empty syscall name is not allowed.
+         * Here, we do not check that the syscall name is valid or not.
+         */
+
+        p = strchr(in, ':');
+        if (p) {
+                e = parse_errno(p + 1);
+                if (e < 0)
+                        return e;
+
+                n = strndup(in, p - in);
+        } else
+                n = strdup(in);
+
+        if (!n)
+                return -ENOMEM;
+
+        if (isempty(n))
+                return -EINVAL;
+
+        *error = e;
+        *name = TAKE_PTR(n);
+
+        return 0;
+}
+
+char *format_bytes(char *buf, size_t l, uint64_t t) {
+        unsigned i;
+
+        /* This only does IEC units so far */
+
+        static const struct {
+                const char *suffix;
+                uint64_t factor;
+        } table[] = {
+                { "E", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
+                { "P", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
+                { "T", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
+                { "G", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
+                { "M", UINT64_C(1024)*UINT64_C(1024) },
+                { "K", UINT64_C(1024) },
+        };
+
+        if (t == (uint64_t) -1)
+                return NULL;
+
+        for (i = 0; i < ELEMENTSOF(table); i++) {
+
+                if (t >= table[i].factor) {
+                        snprintf(buf, l,
+                                 "%" PRIu64 ".%" PRIu64 "%s",
+                                 t / table[i].factor,
+                                 ((t*UINT64_C(10)) / table[i].factor) % UINT64_C(10),
+                                 table[i].suffix);
+
+                        goto finish;
+                }
+        }
+
+        snprintf(buf, l, "%" PRIu64 "B", t);
+
+finish:
+        buf[l-1] = 0;
+        return buf;
+
+}
+
+int safe_atou_full(const char *s, unsigned base, unsigned *ret_u) {
+        char *x = NULL;
+        unsigned long l;
+
+        assert(s);
+        assert(ret_u);
+        assert(base <= 16);
+
+        /* strtoul() is happy to parse negative values, and silently
+         * converts them to unsigned values without generating an
+         * error. We want a clean error, hence let's look for the "-"
+         * prefix on our own, and generate an error. But let's do so
+         * only after strtoul() validated that the string is clean
+         * otherwise, so that we return EINVAL preferably over
+         * ERANGE. */
+
+        s += strspn(s, WHITESPACE);
+
+        errno = 0;
+        l = strtoul(s, &x, base);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+        if (s[0] == '-')
+                return -ERANGE;
+        if ((unsigned long) (unsigned) l != l)
+                return -ERANGE;
+
+        *ret_u = (unsigned) l;
+        return 0;
+}
+
+int safe_atoi(const char *s, int *ret_i) {
+        char *x = NULL;
+        long l;
+
+        assert(s);
+        assert(ret_i);
+
+        errno = 0;
+        l = strtol(s, &x, 0);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+        if ((long) (int) l != l)
+                return -ERANGE;
+
+        *ret_i = (int) l;
+        return 0;
+}
+
+int safe_atollu(const char *s, long long unsigned *ret_llu) {
+        char *x = NULL;
+        unsigned long long l;
+
+        assert(s);
+        assert(ret_llu);
+
+        s += strspn(s, WHITESPACE);
+
+        errno = 0;
+        l = strtoull(s, &x, 0);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+        if (*s == '-')
+                return -ERANGE;
+
+        *ret_llu = l;
+        return 0;
+}
+
+int safe_atolli(const char *s, long long int *ret_lli) {
+        char *x = NULL;
+        long long l;
+
+        assert(s);
+        assert(ret_lli);
+
+        errno = 0;
+        l = strtoll(s, &x, 0);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+
+        *ret_lli = l;
+        return 0;
+}
+
+int safe_atou8(const char *s, uint8_t *ret) {
+        char *x = NULL;
+        unsigned long l;
+
+        assert(s);
+        assert(ret);
+
+        s += strspn(s, WHITESPACE);
+
+        errno = 0;
+        l = strtoul(s, &x, 0);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+        if (s[0] == '-')
+                return -ERANGE;
+        if ((unsigned long) (uint8_t) l != l)
+                return -ERANGE;
+
+        *ret = (uint8_t) l;
+        return 0;
+}
+
+int safe_atou16_full(const char *s, unsigned base, uint16_t *ret) {
+        char *x = NULL;
+        unsigned long l;
+
+        assert(s);
+        assert(ret);
+        assert(base <= 16);
+
+        s += strspn(s, WHITESPACE);
+
+        errno = 0;
+        l = strtoul(s, &x, base);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+        if (s[0] == '-')
+                return -ERANGE;
+        if ((unsigned long) (uint16_t) l != l)
+                return -ERANGE;
+
+        *ret = (uint16_t) l;
+        return 0;
+}
+
+int safe_atoi16(const char *s, int16_t *ret) {
+        char *x = NULL;
+        long l;
+
+        assert(s);
+        assert(ret);
+
+        errno = 0;
+        l = strtol(s, &x, 0);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+        if ((long) (int16_t) l != l)
+                return -ERANGE;
+
+        *ret = (int16_t) l;
+        return 0;
+}
+
+int safe_atod(const char *s, double *ret_d) {
+        _cleanup_(freelocalep) locale_t loc = (locale_t) 0;
+        char *x = NULL;
+        double d = 0;
+
+        assert(s);
+        assert(ret_d);
+
+        loc = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0);
+        if (loc == (locale_t) 0)
+                return -errno;
+
+        errno = 0;
+        d = strtod_l(s, &x, loc);
+        if (errno > 0)
+                return -errno;
+        if (!x || x == s || *x != 0)
+                return -EINVAL;
+
+        *ret_d = (double) d;
+        return 0;
+}
+
+int parse_fractional_part_u(const char **p, size_t digits, unsigned *res) {
+        size_t i;
+        unsigned val = 0;
+        const char *s;
+
+        s = *p;
+
+        /* accept any number of digits, strtoull is limited to 19 */
+        for (i=0; i < digits; i++,s++) {
+                if (*s < '0' || *s > '9') {
+                        if (i == 0)
+                                return -EINVAL;
+
+                        /* too few digits, pad with 0 */
+                        for (; i < digits; i++)
+                                val *= 10;
+
+                        break;
+                }
+
+                val *= 10;
+                val += *s - '0';
+        }
+
+        /* maybe round up */
+        if (*s >= '5' && *s <= '9')
+                val++;
+
+        s += strspn(s, DIGITS);
+
+        *p = s;
+        *res = val;
+
+        return 0;
+}
+
+int parse_percent_unbounded(const char *p) {
+        const char *pc, *n;
+        int r, v;
+
+        pc = endswith(p, "%");
+        if (!pc)
+                return -EINVAL;
+
+        n = strndupa(p, pc - p);
+        r = safe_atoi(n, &v);
+        if (r < 0)
+                return r;
+        if (v < 0)
+                return -ERANGE;
+
+        return v;
+}
+
+int parse_percent(const char *p) {
+        int v;
+
+        v = parse_percent_unbounded(p);
+        if (v > 100)
+                return -ERANGE;
+
+        return v;
+}
+
+int parse_permille_unbounded(const char *p) {
+        const char *pc, *pm, *dot, *n;
+        int r, q, v;
+
+        pm = endswith(p, "‰");
+        if (pm) {
+                n = strndupa(p, pm - p);
+                r = safe_atoi(n, &v);
+                if (r < 0)
+                        return r;
+                if (v < 0)
+                        return -ERANGE;
+        } else {
+                pc = endswith(p, "%");
+                if (!pc)
+                        return -EINVAL;
+
+                dot = memchr(p, '.', pc - p);
+                if (dot) {
+                        if (dot + 2 != pc)
+                                return -EINVAL;
+                        if (dot[1] < '0' || dot[1] > '9')
+                                return -EINVAL;
+                        q = dot[1] - '0';
+                        n = strndupa(p, dot - p);
+                } else {
+                        q = 0;
+                        n = strndupa(p, pc - p);
+                }
+                r = safe_atoi(n, &v);
+                if (r < 0)
+                        return r;
+                if (v < 0)
+                        return -ERANGE;
+                if (v > (INT_MAX - q) / 10)
+                        return -ERANGE;
+
+                v = v * 10 + q;
+        }
+
+        return v;
+}
+
+int parse_permille(const char *p) {
+        int v;
+
+        v = parse_permille_unbounded(p);
+        if (v > 1000)
+                return -ERANGE;
+
+        return v;
+}
+
+int parse_nice(const char *p, int *ret) {
+        int n, r;
+
+        r = safe_atoi(p, &n);
+        if (r < 0)
+                return r;
+
+        if (!nice_is_valid(n))
+                return -ERANGE;
+
+        *ret = n;
+        return 0;
+}
+
+int parse_ip_port(const char *s, uint16_t *ret) {
+        uint16_t l;
+        int r;
+
+        r = safe_atou16(s, &l);
+        if (r < 0)
+                return r;
+
+        if (l == 0)
+                return -EINVAL;
+
+        *ret = (uint16_t) l;
+
+        return 0;
+}
+
+int parse_ip_port_range(const char *s, uint16_t *low, uint16_t *high) {
+        unsigned l, h;
+        int r;
+
+        r = parse_range(s, &l, &h);
+        if (r < 0)
+                return r;
+
+        if (l <= 0 || l > 65535 || h <= 0 || h > 65535)
+                return -EINVAL;
+
+        if (h < l)
+                return -EINVAL;
+
+        *low = l;
+        *high = h;
+
+        return 0;
+}
+
+int parse_dev(const char *s, dev_t *ret) {
+        const char *major;
+        unsigned x, y;
+        size_t n;
+        int r;
+
+        n = strspn(s, DIGITS);
+        if (n == 0)
+                return -EINVAL;
+        if (s[n] != ':')
+                return -EINVAL;
+
+        major = strndupa(s, n);
+        r = safe_atou(major, &x);
+        if (r < 0)
+                return r;
+
+        r = safe_atou(s + n + 1, &y);
+        if (r < 0)
+                return r;
+
+        if (!DEVICE_MAJOR_VALID(x) || !DEVICE_MINOR_VALID(y))
+                return -ERANGE;
+
+        *ret = makedev(x, y);
+        return 0;
+}
+
+int parse_oom_score_adjust(const char *s, int *ret) {
+        int r, v;
+
+        assert(s);
+        assert(ret);
+
+        r = safe_atoi(s, &v);
+        if (r < 0)
+                return r;
+
+        if (v < OOM_SCORE_ADJ_MIN || v > OOM_SCORE_ADJ_MAX)
+                return -ERANGE;
+
+        *ret = v;
+        return 0;
+}
diff --git a/src/basic/parse-util.h b/src/basic/parse-util.h
new file mode 100644
index 0000000..e47641b
--- /dev/null
+++ b/src/basic/parse-util.h
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "macro.h"
+
+#define MODE_INVALID ((mode_t) -1)
+
+int parse_boolean(const char *v) _pure_;
+int parse_dev(const char *s, dev_t *ret);
+int parse_pid(const char *s, pid_t* ret_pid);
+int parse_mode(const char *s, mode_t *ret);
+int parse_ifindex(const char *s, int *ret);
+int parse_mtu(int family, const char *s, uint32_t *ret);
+
+int parse_size(const char *t, uint64_t base, uint64_t *size);
+int parse_range(const char *t, unsigned *lower, unsigned *upper);
+int parse_errno(const char *t);
+int parse_syscall_and_errno(const char *in, char **name, int *error);
+
+#define FORMAT_BYTES_MAX 8
+char *format_bytes(char *buf, size_t l, uint64_t t);
+
+int safe_atou_full(const char *s, unsigned base, unsigned *ret_u);
+
+static inline int safe_atou(const char *s, unsigned *ret_u) {
+        return safe_atou_full(s, 0, ret_u);
+}
+
+int safe_atoi(const char *s, int *ret_i);
+int safe_atollu(const char *s, unsigned long long *ret_u);
+int safe_atolli(const char *s, long long int *ret_i);
+
+int safe_atou8(const char *s, uint8_t *ret);
+
+int safe_atou16_full(const char *s, unsigned base, uint16_t *ret);
+
+static inline int safe_atou16(const char *s, uint16_t *ret) {
+        return safe_atou16_full(s, 0, ret);
+}
+
+static inline int safe_atoux16(const char *s, uint16_t *ret) {
+        return safe_atou16_full(s, 16, ret);
+}
+
+int safe_atoi16(const char *s, int16_t *ret);
+
+static inline int safe_atou32(const char *s, uint32_t *ret_u) {
+        assert_cc(sizeof(uint32_t) == sizeof(unsigned));
+        return safe_atou(s, (unsigned*) ret_u);
+}
+
+static inline int safe_atoi32(const char *s, int32_t *ret_i) {
+        assert_cc(sizeof(int32_t) == sizeof(int));
+        return safe_atoi(s, (int*) ret_i);
+}
+
+static inline int safe_atou64(const char *s, uint64_t *ret_u) {
+        assert_cc(sizeof(uint64_t) == sizeof(unsigned long long));
+        return safe_atollu(s, (unsigned long long*) ret_u);
+}
+
+static inline int safe_atoi64(const char *s, int64_t *ret_i) {
+        assert_cc(sizeof(int64_t) == sizeof(long long int));
+        return safe_atolli(s, (long long int*) ret_i);
+}
+
+#if LONG_MAX == INT_MAX
+static inline int safe_atolu(const char *s, unsigned long *ret_u) {
+        assert_cc(sizeof(unsigned long) == sizeof(unsigned));
+        return safe_atou(s, (unsigned*) ret_u);
+}
+static inline int safe_atoli(const char *s, long int *ret_u) {
+        assert_cc(sizeof(long int) == sizeof(int));
+        return safe_atoi(s, (int*) ret_u);
+}
+#else
+static inline int safe_atolu(const char *s, unsigned long *ret_u) {
+        assert_cc(sizeof(unsigned long) == sizeof(unsigned long long));
+        return safe_atollu(s, (unsigned long long*) ret_u);
+}
+static inline int safe_atoli(const char *s, long int *ret_u) {
+        assert_cc(sizeof(long int) == sizeof(long long int));
+        return safe_atolli(s, (long long int*) ret_u);
+}
+#endif
+
+#if SIZE_MAX == UINT_MAX
+static inline int safe_atozu(const char *s, size_t *ret_u) {
+        assert_cc(sizeof(size_t) == sizeof(unsigned));
+        return safe_atou(s, (unsigned *) ret_u);
+}
+#else
+static inline int safe_atozu(const char *s, size_t *ret_u) {
+        assert_cc(sizeof(size_t) == sizeof(long unsigned));
+        return safe_atolu(s, ret_u);
+}
+#endif
+
+int safe_atod(const char *s, double *ret_d);
+
+int parse_fractional_part_u(const char **s, size_t digits, unsigned *res);
+
+int parse_percent_unbounded(const char *p);
+int parse_percent(const char *p);
+
+int parse_permille_unbounded(const char *p);
+int parse_permille(const char *p);
+
+int parse_nice(const char *p, int *ret);
+
+int parse_ip_port(const char *s, uint16_t *ret);
+int parse_ip_port_range(const char *s, uint16_t *low, uint16_t *high);
+
+int parse_oom_score_adjust(const char *s, int *ret);
diff --git a/src/basic/path-util.c b/src/basic/path-util.c
new file mode 100644
index 0000000..2215173
--- /dev/null
+++ b/src/basic/path-util.c
@@ -0,0 +1,1150 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* When we include libgen.h because we need dirname() we immediately
+ * undefine basename() since libgen.h defines it as a macro to the
+ * POSIX version which is really broken. We prefer GNU basename(). */
+#include <libgen.h>
+#undef basename
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "fs-util.h"
+#include "glob-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "utf8.h"
+
+bool path_is_absolute(const char *p) {
+        return p[0] == '/';
+}
+
+bool is_path(const char *p) {
+        return !!strchr(p, '/');
+}
+
+int path_split_and_make_absolute(const char *p, char ***ret) {
+        char **l;
+        int r;
+
+        assert(p);
+        assert(ret);
+
+        l = strv_split(p, ":");
+        if (!l)
+                return -ENOMEM;
+
+        r = path_strv_make_absolute_cwd(l);
+        if (r < 0) {
+                strv_free(l);
+                return r;
+        }
+
+        *ret = l;
+        return r;
+}
+
+char *path_make_absolute(const char *p, const char *prefix) {
+        assert(p);
+
+        /* Makes every item in the list an absolute path by prepending
+         * the prefix, if specified and necessary */
+
+        if (path_is_absolute(p) || isempty(prefix))
+                return strdup(p);
+
+        if (endswith(prefix, "/"))
+                return strjoin(prefix, p);
+        else
+                return strjoin(prefix, "/", p);
+}
+
+int safe_getcwd(char **ret) {
+        char *cwd;
+
+        cwd = get_current_dir_name();
+        if (!cwd)
+                return negative_errno();
+
+        /* Let's make sure the directory is really absolute, to protect us from the logic behind
+         * CVE-2018-1000001 */
+        if (cwd[0] != '/') {
+                free(cwd);
+                return -ENOMEDIUM;
+        }
+
+        *ret = cwd;
+        return 0;
+}
+
+int path_make_absolute_cwd(const char *p, char **ret) {
+        char *c;
+        int r;
+
+        assert(p);
+        assert(ret);
+
+        /* Similar to path_make_absolute(), but prefixes with the
+         * current working directory. */
+
+        if (path_is_absolute(p))
+                c = strdup(p);
+        else {
+                _cleanup_free_ char *cwd = NULL;
+
+                r = safe_getcwd(&cwd);
+                if (r < 0)
+                        return r;
+
+                c = path_join(cwd, p);
+        }
+        if (!c)
+                return -ENOMEM;
+
+        *ret = c;
+        return 0;
+}
+
+int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
+        char *f, *t, *r, *p;
+        unsigned n_parents = 0;
+
+        assert(from_dir);
+        assert(to_path);
+        assert(_r);
+
+        /* Strips the common part, and adds ".." elements as necessary. */
+
+        if (!path_is_absolute(from_dir) || !path_is_absolute(to_path))
+                return -EINVAL;
+
+        f = strdupa(from_dir);
+        t = strdupa(to_path);
+
+        path_simplify(f, true);
+        path_simplify(t, true);
+
+        /* Skip the common part. */
+        for (;;) {
+                size_t a, b;
+
+                f += *f == '/';
+                t += *t == '/';
+
+                if (!*f) {
+                        if (!*t)
+                                /* from_dir equals to_path. */
+                                r = strdup(".");
+                        else
+                                /* from_dir is a parent directory of to_path. */
+                                r = strdup(t);
+                        if (!r)
+                                return -ENOMEM;
+
+                        *_r = r;
+                        return 0;
+                }
+
+                if (!*t)
+                        break;
+
+                a = strcspn(f, "/");
+                b = strcspn(t, "/");
+
+                if (a != b || memcmp(f, t, a) != 0)
+                        break;
+
+                f += a;
+                t += b;
+        }
+
+        /* If we're here, then "from_dir" has one or more elements that need to
+         * be replaced with "..". */
+
+        /* Count the number of necessary ".." elements. */
+        for (; *f;) {
+                size_t w;
+
+                w = strcspn(f, "/");
+
+                /* If this includes ".." we can't do a simple series of "..", refuse */
+                if (w == 2 && f[0] == '.' && f[1] == '.')
+                        return -EINVAL;
+
+                /* Count number of elements */
+                n_parents++;
+
+                f += w;
+                f += *f == '/';
+        }
+
+        r = new(char, n_parents * 3 + strlen(t) + 1);
+        if (!r)
+                return -ENOMEM;
+
+        for (p = r; n_parents > 0; n_parents--)
+                p = mempcpy(p, "../", 3);
+
+        if (*t)
+                strcpy(p, t);
+        else
+                /* Remove trailing slash */
+                *(--p) = 0;
+
+        *_r = r;
+        return 0;
+}
+
+int path_strv_make_absolute_cwd(char **l) {
+        char **s;
+        int r;
+
+        /* Goes through every item in the string list and makes it
+         * absolute. This works in place and won't rollback any
+         * changes on failure. */
+
+        STRV_FOREACH(s, l) {
+                char *t;
+
+                r = path_make_absolute_cwd(*s, &t);
+                if (r < 0)
+                        return r;
+
+                path_simplify(t, false);
+                free_and_replace(*s, t);
+        }
+
+        return 0;
+}
+
+char **path_strv_resolve(char **l, const char *root) {
+        char **s;
+        unsigned k = 0;
+        bool enomem = false;
+        int r;
+
+        if (strv_isempty(l))
+                return l;
+
+        /* Goes through every item in the string list and canonicalize
+         * the path. This works in place and won't rollback any
+         * changes on failure. */
+
+        STRV_FOREACH(s, l) {
+                _cleanup_free_ char *orig = NULL;
+                char *t, *u;
+
+                if (!path_is_absolute(*s)) {
+                        free(*s);
+                        continue;
+                }
+
+                if (root) {
+                        orig = *s;
+                        t = prefix_root(root, orig);
+                        if (!t) {
+                                enomem = true;
+                                continue;
+                        }
+                } else
+                        t = *s;
+
+                r = chase_symlinks(t, root, 0, &u);
+                if (r == -ENOENT) {
+                        if (root) {
+                                u = TAKE_PTR(orig);
+                                free(t);
+                        } else
+                                u = t;
+                } else if (r < 0) {
+                        free(t);
+
+                        if (r == -ENOMEM)
+                                enomem = true;
+
+                        continue;
+                } else if (root) {
+                        char *x;
+
+                        free(t);
+                        x = path_startswith(u, root);
+                        if (x) {
+                                /* restore the slash if it was lost */
+                                if (!startswith(x, "/"))
+                                        *(--x) = '/';
+
+                                t = strdup(x);
+                                free(u);
+                                if (!t) {
+                                        enomem = true;
+                                        continue;
+                                }
+                                u = t;
+                        } else {
+                                /* canonicalized path goes outside of
+                                 * prefix, keep the original path instead */
+                                free_and_replace(u, orig);
+                        }
+                } else
+                        free(t);
+
+                l[k++] = u;
+        }
+
+        l[k] = NULL;
+
+        if (enomem)
+                return NULL;
+
+        return l;
+}
+
+char **path_strv_resolve_uniq(char **l, const char *root) {
+
+        if (strv_isempty(l))
+                return l;
+
+        if (!path_strv_resolve(l, root))
+                return NULL;
+
+        return strv_uniq(l);
+}
+
+char *path_simplify(char *path, bool kill_dots) {
+        char *f, *t;
+        bool slash = false, ignore_slash = false, absolute;
+
+        assert(path);
+
+        /* Removes redundant inner and trailing slashes. Also removes unnecessary dots
+         * if kill_dots is true. Modifies the passed string in-place.
+         *
+         * ///foo//./bar/.   becomes /foo/./bar/.      (if kill_dots is false)
+         * ///foo//./bar/.   becomes /foo/bar          (if kill_dots is true)
+         * .//./foo//./bar/. becomes ././foo/./bar/.   (if kill_dots is false)
+         * .//./foo//./bar/. becomes foo/bar           (if kill_dots is true)
+         */
+
+        if (isempty(path))
+                return path;
+
+        absolute = path_is_absolute(path);
+
+        f = path;
+        if (kill_dots && *f == '.' && IN_SET(f[1], 0, '/')) {
+                ignore_slash = true;
+                f++;
+        }
+
+        for (t = path; *f; f++) {
+
+                if (*f == '/') {
+                        slash = true;
+                        continue;
+                }
+
+                if (slash) {
+                        if (kill_dots && *f == '.' && IN_SET(f[1], 0, '/'))
+                                continue;
+
+                        slash = false;
+                        if (ignore_slash)
+                                ignore_slash = false;
+                        else
+                                *(t++) = '/';
+                }
+
+                *(t++) = *f;
+        }
+
+        /* Special rule, if we stripped everything, we either need a "/" (for the root directory)
+         * or "." for the current directory */
+        if (t == path) {
+                if (absolute)
+                        *(t++) = '/';
+                else
+                        *(t++) = '.';
+        }
+
+        *t = 0;
+        return path;
+}
+
+char* path_startswith(const char *path, const char *prefix) {
+        assert(path);
+        assert(prefix);
+
+        /* Returns a pointer to the start of the first component after the parts matched by
+         * the prefix, iff
+         * - both paths are absolute or both paths are relative,
+         * and
+         * - each component in prefix in turn matches a component in path at the same position.
+         * An empty string will be returned when the prefix and path are equivalent.
+         *
+         * Returns NULL otherwise.
+         */
+
+        if ((path[0] == '/') != (prefix[0] == '/'))
+                return NULL;
+
+        for (;;) {
+                size_t a, b;
+
+                path += strspn(path, "/");
+                prefix += strspn(prefix, "/");
+
+                if (*prefix == 0)
+                        return (char*) path;
+
+                if (*path == 0)
+                        return NULL;
+
+                a = strcspn(path, "/");
+                b = strcspn(prefix, "/");
+
+                if (a != b)
+                        return NULL;
+
+                if (memcmp(path, prefix, a) != 0)
+                        return NULL;
+
+                path += a;
+                prefix += b;
+        }
+}
+
+int path_compare(const char *a, const char *b) {
+        int d;
+
+        assert(a);
+        assert(b);
+
+        /* A relative path and an absolute path must not compare as equal.
+         * Which one is sorted before the other does not really matter.
+         * Here a relative path is ordered before an absolute path. */
+        d = (a[0] == '/') - (b[0] == '/');
+        if (d != 0)
+                return d;
+
+        for (;;) {
+                size_t j, k;
+
+                a += strspn(a, "/");
+                b += strspn(b, "/");
+
+                if (*a == 0 && *b == 0)
+                        return 0;
+
+                /* Order prefixes first: "/foo" before "/foo/bar" */
+                if (*a == 0)
+                        return -1;
+                if (*b == 0)
+                        return 1;
+
+                j = strcspn(a, "/");
+                k = strcspn(b, "/");
+
+                /* Alphabetical sort: "/foo/aaa" before "/foo/b" */
+                d = memcmp(a, b, MIN(j, k));
+                if (d != 0)
+                        return (d > 0) - (d < 0); /* sign of d */
+
+                /* Sort "/foo/a" before "/foo/aaa" */
+                d = (j > k) - (j < k);  /* sign of (j - k) */
+                if (d != 0)
+                        return d;
+
+                a += j;
+                b += k;
+        }
+}
+
+bool path_equal(const char *a, const char *b) {
+        return path_compare(a, b) == 0;
+}
+
+bool path_equal_or_files_same(const char *a, const char *b, int flags) {
+        return path_equal(a, b) || files_same(a, b, flags) > 0;
+}
+
+char* path_join_internal(const char *first, ...) {
+        char *joined, *q;
+        const char *p;
+        va_list ap;
+        bool slash;
+        size_t sz;
+
+        /* Joins all listed strings until the sentinel and places a "/" between them unless the strings end/begin
+         * already with one so that it is unnecessary. Note that slashes which are already duplicate won't be
+         * removed. The string returned is hence always equal to or longer than the sum of the lengths of each
+         * individual string.
+         *
+         * Note: any listed empty string is simply skipped. This can be useful for concatenating strings of which some
+         * are optional.
+         *
+         * Examples:
+         *
+         * path_join("foo", "bar") → "foo/bar"
+         * path_join("foo/", "bar") → "foo/bar"
+         * path_join("", "foo", "", "bar", "") → "foo/bar" */
+
+        sz = strlen_ptr(first);
+        va_start(ap, first);
+        while ((p = va_arg(ap, char*)) != (const char*) -1)
+                if (!isempty(p))
+                        sz += 1 + strlen(p);
+        va_end(ap);
+
+        joined = new(char, sz + 1);
+        if (!joined)
+                return NULL;
+
+        if (!isempty(first)) {
+                q = stpcpy(joined, first);
+                slash = endswith(first, "/");
+        } else {
+                /* Skip empty items */
+                joined[0] = 0;
+                q = joined;
+                slash = true; /* no need to generate a slash anymore */
+        }
+
+        va_start(ap, first);
+        while ((p = va_arg(ap, char*)) != (const char*) -1) {
+                if (isempty(p))
+                        continue;
+
+                if (!slash && p[0] != '/')
+                        *(q++) = '/';
+
+                q = stpcpy(q, p);
+                slash = endswith(p, "/");
+        }
+        va_end(ap);
+
+        return joined;
+}
+
+int find_binary(const char *name, char **ret) {
+        int last_error, r;
+        const char *p;
+
+        assert(name);
+
+        if (is_path(name)) {
+                if (access(name, X_OK) < 0)
+                        return -errno;
+
+                if (ret) {
+                        r = path_make_absolute_cwd(name, ret);
+                        if (r < 0)
+                                return r;
+                }
+
+                return 0;
+        }
+
+        /**
+         * Plain getenv, not secure_getenv, because we want
+         * to actually allow the user to pick the binary.
+         */
+        p = getenv("PATH");
+        if (!p)
+                p = DEFAULT_PATH;
+
+        last_error = -ENOENT;
+
+        for (;;) {
+                _cleanup_free_ char *j = NULL, *element = NULL;
+
+                r = extract_first_word(&p, &element, ":", EXTRACT_RELAX|EXTRACT_DONT_COALESCE_SEPARATORS);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (!path_is_absolute(element))
+                        continue;
+
+                j = strjoin(element, "/", name);
+                if (!j)
+                        return -ENOMEM;
+
+                if (access(j, X_OK) >= 0) {
+                        /* Found it! */
+
+                        if (ret) {
+                                *ret = path_simplify(j, false);
+                                j = NULL;
+                        }
+
+                        return 0;
+                }
+
+                last_error = -errno;
+        }
+
+        return last_error;
+}
+
+bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) {
+        bool changed = false;
+        const char* const* i;
+
+        assert(timestamp);
+
+        if (!paths)
+                return false;
+
+        STRV_FOREACH(i, paths) {
+                struct stat stats;
+                usec_t u;
+
+                if (stat(*i, &stats) < 0)
+                        continue;
+
+                u = timespec_load(&stats.st_mtim);
+
+                /* first check */
+                if (*timestamp >= u)
+                        continue;
+
+                log_debug("timestamp of '%s' changed", *i);
+
+                /* update timestamp */
+                if (update) {
+                        *timestamp = u;
+                        changed = true;
+                } else
+                        return true;
+        }
+
+        return changed;
+}
+
+static int binary_is_good(const char *binary) {
+        _cleanup_free_ char *p = NULL, *d = NULL;
+        int r;
+
+        r = find_binary(binary, &p);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return r;
+
+        /* An fsck that is linked to /bin/true is a non-existent
+         * fsck */
+
+        r = readlink_malloc(p, &d);
+        if (r == -EINVAL) /* not a symlink */
+                return 1;
+        if (r < 0)
+                return r;
+
+        return !PATH_IN_SET(d, "true"
+                               "/bin/true",
+                               "/usr/bin/true",
+                               "/dev/null");
+}
+
+int fsck_exists(const char *fstype) {
+        const char *checker;
+
+        assert(fstype);
+
+        if (streq(fstype, "auto"))
+                return -EINVAL;
+
+        checker = strjoina("fsck.", fstype);
+        return binary_is_good(checker);
+}
+
+int mkfs_exists(const char *fstype) {
+        const char *mkfs;
+
+        assert(fstype);
+
+        if (streq(fstype, "auto"))
+                return -EINVAL;
+
+        mkfs = strjoina("mkfs.", fstype);
+        return binary_is_good(mkfs);
+}
+
+char *prefix_root(const char *root, const char *path) {
+        char *n, *p;
+        size_t l;
+
+        /* If root is passed, prefixes path with it. Otherwise returns
+         * it as is. */
+
+        assert(path);
+
+        /* First, drop duplicate prefixing slashes from the path */
+        while (path[0] == '/' && path[1] == '/')
+                path++;
+
+        if (empty_or_root(root))
+                return strdup(path);
+
+        l = strlen(root) + 1 + strlen(path) + 1;
+
+        n = new(char, l);
+        if (!n)
+                return NULL;
+
+        p = stpcpy(n, root);
+
+        while (p > n && p[-1] == '/')
+                p--;
+
+        if (path[0] != '/')
+                *(p++) = '/';
+
+        strcpy(p, path);
+        return n;
+}
+
+int parse_path_argument_and_warn(const char *path, bool suppress_root, char **arg) {
+        char *p;
+        int r;
+
+        /*
+         * This function is intended to be used in command line
+         * parsers, to handle paths that are passed in. It makes the
+         * path absolute, and reduces it to NULL if omitted or
+         * root (the latter optionally).
+         *
+         * NOTE THAT THIS WILL FREE THE PREVIOUS ARGUMENT POINTER ON
+         * SUCCESS! Hence, do not pass in uninitialized pointers.
+         */
+
+        if (isempty(path)) {
+                *arg = mfree(*arg);
+                return 0;
+        }
+
+        r = path_make_absolute_cwd(path, &p);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse path \"%s\" and make it absolute: %m", path);
+
+        path_simplify(p, false);
+        if (suppress_root && empty_or_root(p))
+                p = mfree(p);
+
+        free_and_replace(*arg, p);
+
+        return 0;
+}
+
+char* dirname_malloc(const char *path) {
+        char *d, *dir, *dir2;
+
+        assert(path);
+
+        d = strdup(path);
+        if (!d)
+                return NULL;
+
+        dir = dirname(d);
+        assert(dir);
+
+        if (dir == d)
+                return d;
+
+        dir2 = strdup(dir);
+        free(d);
+
+        return dir2;
+}
+
+const char *last_path_component(const char *path) {
+
+        /* Finds the last component of the path, preserving the optional trailing slash that signifies a directory.
+         *
+         *    a/b/c → c
+         *    a/b/c/ → c/
+         *    x → x
+         *    x/ → x/
+         *    /y → y
+         *    /y/ → y/
+         *    / → /
+         *    // → /
+         *    /foo/a → a
+         *    /foo/a/ → a/
+         *
+         *    Also, the empty string is mapped to itself.
+         *
+         * This is different than basename(), which returns "" when a trailing slash is present.
+         */
+
+        unsigned l, k;
+
+        if (!path)
+                return NULL;
+
+        l = k = strlen(path);
+        if (l == 0) /* special case — an empty string */
+                return path;
+
+        while (k > 0 && path[k-1] == '/')
+                k--;
+
+        if (k == 0) /* the root directory */
+                return path + l - 1;
+
+        while (k > 0 && path[k-1] != '/')
+                k--;
+
+        return path + k;
+}
+
+int path_extract_filename(const char *p, char **ret) {
+        _cleanup_free_ char *a = NULL;
+        const char *c, *e = NULL, *q;
+
+        /* Extracts the filename part (i.e. right-most component) from a path, i.e. string that passes
+         * filename_is_valid(). A wrapper around last_path_component(), but eats up trailing slashes. */
+
+        if (!p)
+                return -EINVAL;
+
+        c = last_path_component(p);
+
+        for (q = c; *q != 0; q++)
+                if (*q != '/')
+                        e = q + 1;
+
+        if (!e) /* no valid character? */
+                return -EINVAL;
+
+        a = strndup(c, e - c);
+        if (!a)
+                return -ENOMEM;
+
+        if (!filename_is_valid(a))
+                return -EINVAL;
+
+        *ret = TAKE_PTR(a);
+
+        return 0;
+}
+
+bool filename_is_valid(const char *p) {
+        const char *e;
+
+        if (isempty(p))
+                return false;
+
+        if (dot_or_dot_dot(p))
+                return false;
+
+        e = strchrnul(p, '/');
+        if (*e != 0)
+                return false;
+
+        if (e - p > FILENAME_MAX) /* FILENAME_MAX is counted *without* the trailing NUL byte */
+                return false;
+
+        return true;
+}
+
+bool path_is_valid(const char *p) {
+
+        if (isempty(p))
+                return false;
+
+        if (strlen(p) >= PATH_MAX) /* PATH_MAX is counted *with* the trailing NUL byte */
+                return false;
+
+        return true;
+}
+
+bool path_is_normalized(const char *p) {
+
+        if (!path_is_valid(p))
+                return false;
+
+        if (dot_or_dot_dot(p))
+                return false;
+
+        if (startswith(p, "../") || endswith(p, "/..") || strstr(p, "/../"))
+                return false;
+
+        if (startswith(p, "./") || endswith(p, "/.") || strstr(p, "/./"))
+                return false;
+
+        if (strstr(p, "//"))
+                return false;
+
+        return true;
+}
+
+char *file_in_same_dir(const char *path, const char *filename) {
+        char *e, *ret;
+        size_t k;
+
+        assert(path);
+        assert(filename);
+
+        /* This removes the last component of path and appends
+         * filename, unless the latter is absolute anyway or the
+         * former isn't */
+
+        if (path_is_absolute(filename))
+                return strdup(filename);
+
+        e = strrchr(path, '/');
+        if (!e)
+                return strdup(filename);
+
+        k = strlen(filename);
+        ret = new(char, (e + 1 - path) + k + 1);
+        if (!ret)
+                return NULL;
+
+        memcpy(mempcpy(ret, path, e + 1 - path), filename, k + 1);
+        return ret;
+}
+
+bool hidden_or_backup_file(const char *filename) {
+        const char *p;
+
+        assert(filename);
+
+        if (filename[0] == '.' ||
+            streq(filename, "lost+found") ||
+            streq(filename, "aquota.user") ||
+            streq(filename, "aquota.group") ||
+            endswith(filename, "~"))
+                return true;
+
+        p = strrchr(filename, '.');
+        if (!p)
+                return false;
+
+        /* Please, let's not add more entries to the list below. If external projects think it's a good idea to come up
+         * with always new suffixes and that everybody else should just adjust to that, then it really should be on
+         * them. Hence, in future, let's not add any more entries. Instead, let's ask those packages to instead adopt
+         * one of the generic suffixes/prefixes for hidden files or backups, possibly augmented with an additional
+         * string. Specifically: there's now:
+         *
+         *    The generic suffixes "~" and ".bak" for backup files
+         *    The generic prefix "." for hidden files
+         *
+         * Thus, if a new package manager "foopkg" wants its own set of ".foopkg-new", ".foopkg-old", ".foopkg-dist"
+         * or so registered, let's refuse that and ask them to use ".foopkg.new", ".foopkg.old" or ".foopkg~" instead.
+         */
+
+        return STR_IN_SET(p + 1,
+                          "rpmnew",
+                          "rpmsave",
+                          "rpmorig",
+                          "dpkg-old",
+                          "dpkg-new",
+                          "dpkg-tmp",
+                          "dpkg-dist",
+                          "dpkg-bak",
+                          "dpkg-backup",
+                          "dpkg-remove",
+                          "ucf-new",
+                          "ucf-old",
+                          "ucf-dist",
+                          "swp",
+                          "bak",
+                          "old",
+                          "new");
+}
+
+bool is_device_path(const char *path) {
+
+        /* Returns true on paths that likely refer to a device, either by path in sysfs or to something in /dev */
+
+        return PATH_STARTSWITH_SET(path, "/dev/", "/sys/");
+}
+
+bool valid_device_node_path(const char *path) {
+
+        /* Some superficial checks whether the specified path is a valid device node path, all without looking at the
+         * actual device node. */
+
+        if (!PATH_STARTSWITH_SET(path, "/dev/", "/run/systemd/inaccessible/"))
+                return false;
+
+        if (endswith(path, "/")) /* can't be a device node if it ends in a slash */
+                return false;
+
+        return path_is_normalized(path);
+}
+
+bool valid_device_allow_pattern(const char *path) {
+        assert(path);
+
+        /* Like valid_device_node_path(), but also allows full-subsystem expressions, like DeviceAllow= and DeviceDeny=
+         * accept it */
+
+        if (STARTSWITH_SET(path, "block-", "char-"))
+                return true;
+
+        return valid_device_node_path(path);
+}
+
+int systemd_installation_has_version(const char *root, unsigned minimal_version) {
+        const char *pattern;
+        int r;
+
+        /* Try to guess if systemd installation is later than the specified version. This
+         * is hacky and likely to yield false negatives, particularly if the installation
+         * is non-standard. False positives should be relatively rare.
+         */
+
+        NULSTR_FOREACH(pattern,
+                       /* /lib works for systems without usr-merge, and for systems with a sane
+                        * usr-merge, where /lib is a symlink to /usr/lib. /usr/lib is necessary
+                        * for Gentoo which does a merge without making /lib a symlink.
+                        */
+                       "lib/systemd/libsystemd-shared-*.so\0"
+                       "lib64/systemd/libsystemd-shared-*.so\0"
+                       "usr/lib/systemd/libsystemd-shared-*.so\0"
+                       "usr/lib64/systemd/libsystemd-shared-*.so\0") {
+
+                _cleanup_strv_free_ char **names = NULL;
+                _cleanup_free_ char *path = NULL;
+                char *c, **name;
+
+                path = prefix_root(root, pattern);
+                if (!path)
+                        return -ENOMEM;
+
+                r = glob_extend(&names, path);
+                if (r == -ENOENT)
+                        continue;
+                if (r < 0)
+                        return r;
+
+                assert_se(c = endswith(path, "*.so"));
+                *c = '\0'; /* truncate the glob part */
+
+                STRV_FOREACH(name, names) {
+                        /* This is most likely to run only once, hence let's not optimize anything. */
+                        char *t, *t2;
+                        unsigned version;
+
+                        t = startswith(*name, path);
+                        if (!t)
+                                continue;
+
+                        t2 = endswith(t, ".so");
+                        if (!t2)
+                                continue;
+
+                        t2[0] = '\0'; /* truncate the suffix */
+
+                        r = safe_atou(t, &version);
+                        if (r < 0) {
+                                log_debug_errno(r, "Found libsystemd shared at \"%s.so\", but failed to parse version: %m", *name);
+                                continue;
+                        }
+
+                        log_debug("Found libsystemd shared at \"%s.so\", version %u (%s).",
+                                  *name, version,
+                                  version >= minimal_version ? "OK" : "too old");
+                        if (version >= minimal_version)
+                                return true;
+                }
+        }
+
+        return false;
+}
+
+bool dot_or_dot_dot(const char *path) {
+        if (!path)
+                return false;
+        if (path[0] != '.')
+                return false;
+        if (path[1] == 0)
+                return true;
+        if (path[1] != '.')
+                return false;
+
+        return path[2] == 0;
+}
+
+bool empty_or_root(const char *root) {
+
+        /* For operations relative to some root directory, returns true if the specified root directory is redundant,
+         * i.e. either / or NULL or the empty string or any equivalent. */
+
+        if (!root)
+                return true;
+
+        return root[strspn(root, "/")] == 0;
+}
+
+int path_simplify_and_warn(
+                char *path,
+                unsigned flag,
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *lvalue) {
+
+        bool absolute, fatal = flag & PATH_CHECK_FATAL;
+
+        assert(!FLAGS_SET(flag, PATH_CHECK_ABSOLUTE | PATH_CHECK_RELATIVE));
+
+        if (!utf8_is_valid(path)) {
+                log_syntax_invalid_utf8(unit, LOG_ERR, filename, line, path);
+                return -EINVAL;
+        }
+
+        if (flag & (PATH_CHECK_ABSOLUTE | PATH_CHECK_RELATIVE)) {
+                absolute = path_is_absolute(path);
+
+                if (!absolute && (flag & PATH_CHECK_ABSOLUTE)) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "%s= path is not absolute%s: %s",
+                                   lvalue, fatal ? "" : ", ignoring", path);
+                        return -EINVAL;
+                }
+
+                if (absolute && (flag & PATH_CHECK_RELATIVE)) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0,
+                                   "%s= path is absolute%s: %s",
+                                   lvalue, fatal ? "" : ", ignoring", path);
+                        return -EINVAL;
+                }
+        }
+
+        path_simplify(path, true);
+
+        if (!path_is_normalized(path)) {
+                log_syntax(unit, LOG_ERR, filename, line, 0,
+                           "%s= path is not normalized%s: %s",
+                           lvalue, fatal ? "" : ", ignoring", path);
+                return -EINVAL;
+        }
+
+        if (!path_is_valid(path)) {
+                log_syntax(unit, LOG_ERR, filename, line, 0,
+                           "%s= path has invalid length (%zu bytes)%s.",
+                           lvalue, strlen(path), fatal ? "" : ", ignoring");
+                return -EINVAL;
+        }
+
+        return 0;
+}
diff --git a/src/basic/path-util.h b/src/basic/path-util.h
new file mode 100644
index 0000000..86c5a57
--- /dev/null
+++ b/src/basic/path-util.h
@@ -0,0 +1,190 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <alloca.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+#include "macro.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+
+#define PATH_SPLIT_SBIN_BIN(x) x "sbin:" x "bin"
+#define PATH_SPLIT_SBIN_BIN_NULSTR(x) x "sbin\0" x "bin\0"
+
+#define PATH_NORMAL_SBIN_BIN(x) x "bin"
+#define PATH_NORMAL_SBIN_BIN_NULSTR(x) x "bin\0"
+
+#if HAVE_SPLIT_BIN
+#  define PATH_SBIN_BIN(x) PATH_SPLIT_SBIN_BIN(x)
+#  define PATH_SBIN_BIN_NULSTR(x) PATH_SPLIT_SBIN_BIN_NULSTR(x)
+#else
+#  define PATH_SBIN_BIN(x) PATH_NORMAL_SBIN_BIN(x)
+#  define PATH_SBIN_BIN_NULSTR(x) PATH_NORMAL_SBIN_BIN_NULSTR(x)
+#endif
+
+#define DEFAULT_PATH_NORMAL PATH_SBIN_BIN("/usr/local/") ":" PATH_SBIN_BIN("/usr/")
+#define DEFAULT_PATH_NORMAL_NULSTR PATH_SBIN_BIN_NULSTR("/usr/local/") PATH_SBIN_BIN_NULSTR("/usr/")
+#define DEFAULT_PATH_SPLIT_USR DEFAULT_PATH_NORMAL ":" PATH_SBIN_BIN("/")
+#define DEFAULT_PATH_SPLIT_USR_NULSTR DEFAULT_PATH_NORMAL_NULSTR PATH_SBIN_BIN_NULSTR("/")
+#define DEFAULT_PATH_COMPAT PATH_SPLIT_SBIN_BIN("/usr/local/") ":" PATH_SPLIT_SBIN_BIN("/usr/") ":" PATH_SPLIT_SBIN_BIN("/")
+
+#if HAVE_SPLIT_USR
+#  define DEFAULT_PATH DEFAULT_PATH_SPLIT_USR
+#  define DEFAULT_PATH_NULSTR DEFAULT_PATH_SPLIT_USR_NULSTR
+#else
+#  define DEFAULT_PATH DEFAULT_PATH_NORMAL
+#  define DEFAULT_PATH_NULSTR DEFAULT_PATH_NORMAL_NULSTR
+#endif
+
+bool is_path(const char *p) _pure_;
+int path_split_and_make_absolute(const char *p, char ***ret);
+bool path_is_absolute(const char *p) _pure_;
+char* path_make_absolute(const char *p, const char *prefix);
+int safe_getcwd(char **ret);
+int path_make_absolute_cwd(const char *p, char **ret);
+int path_make_relative(const char *from_dir, const char *to_path, char **_r);
+char* path_startswith(const char *path, const char *prefix) _pure_;
+int path_compare(const char *a, const char *b) _pure_;
+bool path_equal(const char *a, const char *b) _pure_;
+bool path_equal_or_files_same(const char *a, const char *b, int flags);
+char* path_join_internal(const char *first, ...);
+#define path_join(x, ...) path_join_internal(x, __VA_ARGS__, (const char*) -1)
+
+char* path_simplify(char *path, bool kill_dots);
+
+static inline bool path_equal_ptr(const char *a, const char *b) {
+        return !!a == !!b && (!a || path_equal(a, b));
+}
+
+/* Note: the search terminates on the first NULL item. */
+#define PATH_IN_SET(p, ...)                                     \
+        ({                                                      \
+                char **_s;                                      \
+                bool _found = false;                            \
+                STRV_FOREACH(_s, STRV_MAKE(__VA_ARGS__))        \
+                        if (path_equal(p, *_s)) {               \
+                               _found = true;                   \
+                               break;                           \
+                        }                                       \
+                _found;                                         \
+        })
+
+#define PATH_STARTSWITH_SET(p, ...)                             \
+        ({                                                      \
+                const char *_p = (p);                           \
+                char *_found = NULL, **_i;                      \
+                STRV_FOREACH(_i, STRV_MAKE(__VA_ARGS__)) {      \
+                        _found = path_startswith(_p, *_i);      \
+                        if (_found)                             \
+                                break;                          \
+                }                                               \
+                _found;                                         \
+        })
+
+int path_strv_make_absolute_cwd(char **l);
+char** path_strv_resolve(char **l, const char *root);
+char** path_strv_resolve_uniq(char **l, const char *root);
+
+int find_binary(const char *name, char **filename);
+
+bool paths_check_timestamp(const char* const* paths, usec_t *paths_ts_usec, bool update);
+
+int fsck_exists(const char *fstype);
+int mkfs_exists(const char *fstype);
+
+/* Iterates through the path prefixes of the specified path, going up
+ * the tree, to root. Also returns "" (and not "/"!) for the root
+ * directory. Excludes the specified directory itself */
+#define PATH_FOREACH_PREFIX(prefix, path)                               \
+        for (char *_slash = ({                                          \
+                                path_simplify(strcpy(prefix, path), false); \
+                                streq(prefix, "/") ? NULL : strrchr(prefix, '/'); \
+                        });                                             \
+             _slash && ((*_slash = 0), true);                           \
+             _slash = strrchr((prefix), '/'))
+
+/* Same as PATH_FOREACH_PREFIX but also includes the specified path itself */
+#define PATH_FOREACH_PREFIX_MORE(prefix, path)                          \
+        for (char *_slash = ({                                          \
+                                path_simplify(strcpy(prefix, path), false); \
+                                if (streq(prefix, "/"))                 \
+                                        prefix[0] = 0;                  \
+                                strrchr(prefix, 0);                     \
+                        });                                             \
+             _slash && ((*_slash = 0), true);                           \
+             _slash = strrchr((prefix), '/'))
+
+char *prefix_root(const char *root, const char *path);
+
+/* Similar to prefix_root(), but returns an alloca() buffer, or
+ * possibly a const pointer into the path parameter */
+#define prefix_roota(root, path)                                        \
+        ({                                                              \
+                const char* _path = (path), *_root = (root), *_ret;     \
+                char *_p, *_n;                                          \
+                size_t _l;                                              \
+                while (_path[0] == '/' && _path[1] == '/')              \
+                        _path ++;                                       \
+                if (empty_or_root(_root))                               \
+                        _ret = _path;                                   \
+                else {                                                  \
+                        _l = strlen(_root) + 1 + strlen(_path) + 1;     \
+                        _n = newa(char, _l);                            \
+                        _p = stpcpy(_n, _root);                         \
+                        while (_p > _n && _p[-1] == '/')                \
+                                _p--;                                   \
+                        if (_path[0] != '/')                            \
+                                *(_p++) = '/';                          \
+                        strcpy(_p, _path);                              \
+                        _ret = _n;                                      \
+                }                                                       \
+                _ret;                                                   \
+        })
+
+int parse_path_argument_and_warn(const char *path, bool suppress_root, char **arg);
+
+char* dirname_malloc(const char *path);
+const char *last_path_component(const char *path);
+int path_extract_filename(const char *p, char **ret);
+
+bool filename_is_valid(const char *p) _pure_;
+bool path_is_valid(const char *p) _pure_;
+bool path_is_normalized(const char *p) _pure_;
+
+char *file_in_same_dir(const char *path, const char *filename);
+
+bool hidden_or_backup_file(const char *filename) _pure_;
+
+bool is_device_path(const char *path);
+
+bool valid_device_node_path(const char *path);
+bool valid_device_allow_pattern(const char *path);
+
+int systemd_installation_has_version(const char *root, unsigned minimal_version);
+
+bool dot_or_dot_dot(const char *path);
+
+static inline const char *skip_dev_prefix(const char *p) {
+        const char *e;
+
+        /* Drop any /dev prefix if there is any */
+
+        e = path_startswith(p, "/dev/");
+
+        return e ?: p;
+}
+
+bool empty_or_root(const char *root);
+static inline const char *empty_to_root(const char *path) {
+        return isempty(path) ? "/" : path;
+}
+
+enum {
+        PATH_CHECK_FATAL    = 1 << 0,  /* If not set, then error message is appended with 'ignoring'. */
+        PATH_CHECK_ABSOLUTE = 1 << 1,
+        PATH_CHECK_RELATIVE = 1 << 2,
+};
+
+int path_simplify_and_warn(char *path, unsigned flag, const char *unit, const char *filename, unsigned line, const char *lvalue);
diff --git a/src/basic/prioq.c b/src/basic/prioq.c
new file mode 100644
index 0000000..76b27fa
--- /dev/null
+++ b/src/basic/prioq.c
@@ -0,0 +1,300 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+/*
+ * Priority Queue
+ * The prioq object implements a priority queue. That is, it orders objects by
+ * their priority and allows O(1) access to the object with the highest
+ * priority. Insertion and removal are Θ(log n). Optionally, the caller can
+ * provide a pointer to an index which will be kept up-to-date by the prioq.
+ *
+ * The underlying algorithm used in this implementation is a Heap.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "hashmap.h"
+#include "prioq.h"
+
+struct prioq_item {
+        void *data;
+        unsigned *idx;
+};
+
+struct Prioq {
+        compare_func_t compare_func;
+        unsigned n_items, n_allocated;
+
+        struct prioq_item *items;
+};
+
+Prioq *prioq_new(compare_func_t compare_func) {
+        Prioq *q;
+
+        q = new(Prioq, 1);
+        if (!q)
+                return q;
+
+        *q = (Prioq) {
+                .compare_func = compare_func,
+        };
+
+        return q;
+}
+
+Prioq* prioq_free(Prioq *q) {
+        if (!q)
+                return NULL;
+
+        free(q->items);
+        return mfree(q);
+}
+
+int prioq_ensure_allocated(Prioq **q, compare_func_t compare_func) {
+        assert(q);
+
+        if (*q)
+                return 0;
+
+        *q = prioq_new(compare_func);
+        if (!*q)
+                return -ENOMEM;
+
+        return 0;
+}
+
+static void swap(Prioq *q, unsigned j, unsigned k) {
+        assert(q);
+        assert(j < q->n_items);
+        assert(k < q->n_items);
+
+        assert(!q->items[j].idx || *(q->items[j].idx) == j);
+        assert(!q->items[k].idx || *(q->items[k].idx) == k);
+
+        SWAP_TWO(q->items[j].data, q->items[k].data);
+        SWAP_TWO(q->items[j].idx, q->items[k].idx);
+
+        if (q->items[j].idx)
+                *q->items[j].idx = j;
+
+        if (q->items[k].idx)
+                *q->items[k].idx = k;
+}
+
+static unsigned shuffle_up(Prioq *q, unsigned idx) {
+        assert(q);
+        assert(idx < q->n_items);
+
+        while (idx > 0) {
+                unsigned k;
+
+                k = (idx-1)/2;
+
+                if (q->compare_func(q->items[k].data, q->items[idx].data) <= 0)
+                        break;
+
+                swap(q, idx, k);
+                idx = k;
+        }
+
+        return idx;
+}
+
+static unsigned shuffle_down(Prioq *q, unsigned idx) {
+        assert(q);
+
+        for (;;) {
+                unsigned j, k, s;
+
+                k = (idx+1)*2; /* right child */
+                j = k-1;       /* left child */
+
+                if (j >= q->n_items)
+                        break;
+
+                if (q->compare_func(q->items[j].data, q->items[idx].data) < 0)
+
+                        /* So our left child is smaller than we are, let's
+                         * remember this fact */
+                        s = j;
+                else
+                        s = idx;
+
+                if (k < q->n_items &&
+                    q->compare_func(q->items[k].data, q->items[s].data) < 0)
+
+                        /* So our right child is smaller than we are, let's
+                         * remember this fact */
+                        s = k;
+
+                /* s now points to the smallest of the three items */
+
+                if (s == idx)
+                        /* No swap necessary, we're done */
+                        break;
+
+                swap(q, idx, s);
+                idx = s;
+        }
+
+        return idx;
+}
+
+int prioq_put(Prioq *q, void *data, unsigned *idx) {
+        struct prioq_item *i;
+        unsigned k;
+
+        assert(q);
+
+        if (q->n_items >= q->n_allocated) {
+                unsigned n;
+                struct prioq_item *j;
+
+                n = MAX((q->n_items+1) * 2, 16u);
+                j = reallocarray(q->items, n, sizeof(struct prioq_item));
+                if (!j)
+                        return -ENOMEM;
+
+                q->items = j;
+                q->n_allocated = n;
+        }
+
+        k = q->n_items++;
+        i = q->items + k;
+        i->data = data;
+        i->idx = idx;
+
+        if (idx)
+                *idx = k;
+
+        shuffle_up(q, k);
+
+        return 0;
+}
+
+static void remove_item(Prioq *q, struct prioq_item *i) {
+        struct prioq_item *l;
+
+        assert(q);
+        assert(i);
+
+        l = q->items + q->n_items - 1;
+
+        if (i == l)
+                /* Last entry, let's just remove it */
+                q->n_items--;
+        else {
+                unsigned k;
+
+                /* Not last entry, let's replace the last entry with
+                 * this one, and reshuffle */
+
+                k = i - q->items;
+
+                i->data = l->data;
+                i->idx = l->idx;
+                if (i->idx)
+                        *i->idx = k;
+                q->n_items--;
+
+                k = shuffle_down(q, k);
+                shuffle_up(q, k);
+        }
+}
+
+_pure_ static struct prioq_item* find_item(Prioq *q, void *data, unsigned *idx) {
+        struct prioq_item *i;
+
+        assert(q);
+
+        if (q->n_items <= 0)
+                return NULL;
+
+        if (idx) {
+                if (*idx == PRIOQ_IDX_NULL ||
+                    *idx >= q->n_items)
+                        return NULL;
+
+                i = q->items + *idx;
+                if (i->data != data)
+                        return NULL;
+
+                return i;
+        } else {
+                for (i = q->items; i < q->items + q->n_items; i++)
+                        if (i->data == data)
+                                return i;
+                return NULL;
+        }
+}
+
+int prioq_remove(Prioq *q, void *data, unsigned *idx) {
+        struct prioq_item *i;
+
+        if (!q)
+                return 0;
+
+        i = find_item(q, data, idx);
+        if (!i)
+                return 0;
+
+        remove_item(q, i);
+        return 1;
+}
+
+int prioq_reshuffle(Prioq *q, void *data, unsigned *idx) {
+        struct prioq_item *i;
+        unsigned k;
+
+        assert(q);
+
+        i = find_item(q, data, idx);
+        if (!i)
+                return 0;
+
+        k = i - q->items;
+        k = shuffle_down(q, k);
+        shuffle_up(q, k);
+        return 1;
+}
+
+void *prioq_peek_by_index(Prioq *q, unsigned idx) {
+        if (!q)
+                return NULL;
+
+        if (idx >= q->n_items)
+                return NULL;
+
+        return q->items[idx].data;
+}
+
+void *prioq_pop(Prioq *q) {
+        void *data;
+
+        if (!q)
+                return NULL;
+
+        if (q->n_items <= 0)
+                return NULL;
+
+        data = q->items[0].data;
+        remove_item(q, q->items);
+        return data;
+}
+
+unsigned prioq_size(Prioq *q) {
+
+        if (!q)
+                return 0;
+
+        return q->n_items;
+}
+
+bool prioq_isempty(Prioq *q) {
+
+        if (!q)
+                return true;
+
+        return q->n_items <= 0;
+}
diff --git a/src/basic/prioq.h b/src/basic/prioq.h
new file mode 100644
index 0000000..1fb57bf
--- /dev/null
+++ b/src/basic/prioq.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "hashmap.h"
+#include "macro.h"
+
+typedef struct Prioq Prioq;
+
+#define PRIOQ_IDX_NULL ((unsigned) -1)
+
+Prioq *prioq_new(compare_func_t compare);
+Prioq *prioq_free(Prioq *q);
+DEFINE_TRIVIAL_CLEANUP_FUNC(Prioq*, prioq_free);
+int prioq_ensure_allocated(Prioq **q, compare_func_t compare_func);
+
+int prioq_put(Prioq *q, void *data, unsigned *idx);
+int prioq_remove(Prioq *q, void *data, unsigned *idx);
+int prioq_reshuffle(Prioq *q, void *data, unsigned *idx);
+
+void *prioq_peek_by_index(Prioq *q, unsigned idx) _pure_;
+static inline void *prioq_peek(Prioq *q) {
+        return prioq_peek_by_index(q, 0);
+}
+void *prioq_pop(Prioq *q);
+
+#define PRIOQ_FOREACH_ITEM(q, p)                                \
+        for (unsigned _i = 0; (p = prioq_peek_by_index(q, _i)); _i++)
+
+unsigned prioq_size(Prioq *q) _pure_;
+bool prioq_isempty(Prioq *q) _pure_;
diff --git a/src/basic/proc-cmdline.c b/src/basic/proc-cmdline.c
new file mode 100644
index 0000000..1670001
--- /dev/null
+++ b/src/basic/proc-cmdline.c
@@ -0,0 +1,363 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "fileio.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "proc-cmdline.h"
+#include "process-util.h"
+#include "special.h"
+#include "string-util.h"
+#include "util.h"
+#include "virt.h"
+
+int proc_cmdline(char **ret) {
+        const char *e;
+        assert(ret);
+
+        /* For testing purposes it is sometimes useful to be able to override what we consider /proc/cmdline to be */
+        e = secure_getenv("SYSTEMD_PROC_CMDLINE");
+        if (e) {
+                char *m;
+
+                m = strdup(e);
+                if (!m)
+                        return -ENOMEM;
+
+                *ret = m;
+                return 0;
+        }
+
+        if (detect_container() > 0)
+                return get_process_cmdline(1, 0, false, ret);
+        else
+                return read_one_line_file("/proc/cmdline", ret);
+}
+
+static int proc_cmdline_extract_first(const char **p, char **ret_word, ProcCmdlineFlags flags) {
+        const char *q = *p;
+        int r;
+
+        for (;;) {
+                _cleanup_free_ char *word = NULL;
+                const char *c;
+
+                r = extract_first_word(&q, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                /* Filter out arguments that are intended only for the initrd */
+                c = startswith(word, "rd.");
+                if (c) {
+                        if (!in_initrd())
+                                continue;
+
+                        if (FLAGS_SET(flags, PROC_CMDLINE_STRIP_RD_PREFIX)) {
+                                r = free_and_strdup(&word, c);
+                                if (r < 0)
+                                        return r;
+                        }
+
+                } else if (FLAGS_SET(flags, PROC_CMDLINE_RD_STRICT) && in_initrd())
+                        continue; /* And optionally filter out arguments that are intended only for the host */
+
+                *p = q;
+                *ret_word = TAKE_PTR(word);
+                return 1;
+        }
+
+        *p = q;
+        *ret_word = NULL;
+        return 0;
+}
+
+int proc_cmdline_parse_given(const char *line, proc_cmdline_parse_t parse_item, void *data, ProcCmdlineFlags flags) {
+        const char *p;
+        int r;
+
+        assert(parse_item);
+
+        /* The PROC_CMDLINE_VALUE_OPTIONAL flag doesn't really make sense for proc_cmdline_parse(), let's make this
+         * clear. */
+        assert(!FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL));
+
+        p = line;
+        for (;;) {
+                _cleanup_free_ char *word = NULL;
+                char *value;
+
+                r = proc_cmdline_extract_first(&p, &word, flags);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                value = strchr(word, '=');
+                if (value)
+                        *(value++) = 0;
+
+                r = parse_item(word, value, data);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int proc_cmdline_parse(proc_cmdline_parse_t parse_item, void *data, ProcCmdlineFlags flags) {
+        _cleanup_free_ char *line = NULL;
+        int r;
+
+        assert(parse_item);
+
+        r = proc_cmdline(&line);
+        if (r < 0)
+                return r;
+
+        return proc_cmdline_parse_given(line, parse_item, data, flags);
+}
+
+static bool relaxed_equal_char(char a, char b) {
+        return a == b ||
+                (a == '_' && b == '-') ||
+                (a == '-' && b == '_');
+}
+
+char *proc_cmdline_key_startswith(const char *s, const char *prefix) {
+        assert(s);
+        assert(prefix);
+
+        /* Much like startswith(), but considers "-" and "_" the same */
+
+        for (; *prefix != 0; s++, prefix++)
+                if (!relaxed_equal_char(*s, *prefix))
+                        return NULL;
+
+        return (char*) s;
+}
+
+bool proc_cmdline_key_streq(const char *x, const char *y) {
+        assert(x);
+        assert(y);
+
+        /* Much like streq(), but considers "-" and "_" the same */
+
+        for (; *x != 0 || *y != 0; x++, y++)
+                if (!relaxed_equal_char(*x, *y))
+                        return false;
+
+        return true;
+}
+
+int proc_cmdline_get_key(const char *key, ProcCmdlineFlags flags, char **ret_value) {
+        _cleanup_free_ char *line = NULL, *ret = NULL;
+        bool found = false;
+        const char *p;
+        int r;
+
+        /* Looks for a specific key on the kernel command line. Supports three modes:
+         *
+         * a) The "ret_value" parameter is used. In this case a parameter beginning with the "key" string followed by
+         *    "=" is searched for, and the value following it is returned in "ret_value".
+         *
+         * b) as above, but the PROC_CMDLINE_VALUE_OPTIONAL flag is set. In this case if the key is found as a separate
+         *    word (i.e. not followed by "=" but instead by whitespace or the end of the command line), then this is
+         *    also accepted, and "value" is returned as NULL.
+         *
+         * c) The "ret_value" parameter is NULL. In this case a search for the exact "key" parameter is performed.
+         *
+         * In all three cases, > 0 is returned if the key is found, 0 if not. */
+
+        if (isempty(key))
+                return -EINVAL;
+
+        if (FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL) && !ret_value)
+                return -EINVAL;
+
+        r = proc_cmdline(&line);
+        if (r < 0)
+                return r;
+
+        p = line;
+        for (;;) {
+                _cleanup_free_ char *word = NULL;
+
+                r = proc_cmdline_extract_first(&p, &word, flags);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (ret_value) {
+                        const char *e;
+
+                        e = proc_cmdline_key_startswith(word, key);
+                        if (!e)
+                                continue;
+
+                        if (*e == '=') {
+                                r = free_and_strdup(&ret, e+1);
+                                if (r < 0)
+                                        return r;
+
+                                found = true;
+
+                        } else if (*e == 0 && FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL))
+                                found = true;
+
+                } else {
+                        if (streq(word, key)) {
+                                found = true;
+                                break; /* we found what we were looking for */
+                        }
+                }
+        }
+
+        if (ret_value)
+                *ret_value = TAKE_PTR(ret);
+
+        return found;
+}
+
+int proc_cmdline_get_bool(const char *key, bool *ret) {
+        _cleanup_free_ char *v = NULL;
+        int r;
+
+        assert(ret);
+
+        r = proc_cmdline_get_key(key, PROC_CMDLINE_VALUE_OPTIONAL, &v);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                *ret = false;
+                return 0;
+        }
+
+        if (v) { /* parameter passed */
+                r = parse_boolean(v);
+                if (r < 0)
+                        return r;
+                *ret = r;
+        } else /* no parameter passed */
+                *ret = true;
+
+        return 1;
+}
+
+int proc_cmdline_get_key_many_internal(ProcCmdlineFlags flags, ...) {
+        _cleanup_free_ char *line = NULL;
+        const char *p;
+        va_list ap;
+        int r, ret = 0;
+
+        /* The PROC_CMDLINE_VALUE_OPTIONAL flag doesn't really make sense for proc_cmdline_get_key_many(), let's make
+         * this clear. */
+        assert(!FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL));
+
+        /* This call may clobber arguments on failure! */
+
+        r = proc_cmdline(&line);
+        if (r < 0)
+                return r;
+
+        p = line;
+        for (;;) {
+                _cleanup_free_ char *word = NULL;
+
+                r = proc_cmdline_extract_first(&p, &word, flags);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                va_start(ap, flags);
+
+                for (;;) {
+                        char **v;
+                        const char *k, *e;
+
+                        k = va_arg(ap, const char*);
+                        if (!k)
+                                break;
+
+                        assert_se(v = va_arg(ap, char**));
+
+                        e = proc_cmdline_key_startswith(word, k);
+                        if (e && *e == '=') {
+                                r = free_and_strdup(v, e + 1);
+                                if (r < 0) {
+                                        va_end(ap);
+                                        return r;
+                                }
+
+                                ret++;
+                        }
+                }
+
+                va_end(ap);
+        }
+
+        return ret;
+}
+
+int shall_restore_state(void) {
+        bool ret;
+        int r;
+
+        r = proc_cmdline_get_bool("systemd.restore_state", &ret);
+        if (r < 0)
+                return r;
+
+        return r > 0 ? ret : true;
+}
+
+static const char * const rlmap[] = {
+        "emergency", SPECIAL_EMERGENCY_TARGET,
+        "-b",        SPECIAL_EMERGENCY_TARGET,
+        "rescue",    SPECIAL_RESCUE_TARGET,
+        "single",    SPECIAL_RESCUE_TARGET,
+        "-s",        SPECIAL_RESCUE_TARGET,
+        "s",         SPECIAL_RESCUE_TARGET,
+        "S",         SPECIAL_RESCUE_TARGET,
+        "1",         SPECIAL_RESCUE_TARGET,
+        "2",         SPECIAL_MULTI_USER_TARGET,
+        "3",         SPECIAL_MULTI_USER_TARGET,
+        "4",         SPECIAL_MULTI_USER_TARGET,
+        "5",         SPECIAL_GRAPHICAL_TARGET,
+        NULL
+};
+
+static const char * const rlmap_initrd[] = {
+        "emergency", SPECIAL_EMERGENCY_TARGET,
+        "rescue",    SPECIAL_RESCUE_TARGET,
+        NULL
+};
+
+const char* runlevel_to_target(const char *word) {
+        const char * const *rlmap_ptr;
+        size_t i;
+
+        if (!word)
+                return NULL;
+
+        if (in_initrd()) {
+                word = startswith(word, "rd.");
+                if (!word)
+                        return NULL;
+        }
+
+        rlmap_ptr = in_initrd() ? rlmap_initrd : rlmap;
+
+        for (i = 0; rlmap_ptr[i]; i += 2)
+                if (streq(word, rlmap_ptr[i]))
+                        return rlmap_ptr[i+1];
+
+        return NULL;
+}
diff --git a/src/basic/proc-cmdline.h b/src/basic/proc-cmdline.h
new file mode 100644
index 0000000..ff04379
--- /dev/null
+++ b/src/basic/proc-cmdline.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "log.h"
+
+typedef enum ProcCmdlineFlags {
+        PROC_CMDLINE_STRIP_RD_PREFIX = 1 << 0,
+        PROC_CMDLINE_VALUE_OPTIONAL  = 1 << 1,
+        PROC_CMDLINE_RD_STRICT       = 1 << 2,
+} ProcCmdlineFlags;
+
+typedef int (*proc_cmdline_parse_t)(const char *key, const char *value, void *data);
+
+int proc_cmdline(char **ret);
+
+int proc_cmdline_parse_given(const char *line, proc_cmdline_parse_t parse_item, void *data, ProcCmdlineFlags flags);
+int proc_cmdline_parse(const proc_cmdline_parse_t parse, void *userdata, ProcCmdlineFlags flags);
+
+int proc_cmdline_get_key(const char *parameter, ProcCmdlineFlags flags, char **value);
+int proc_cmdline_get_bool(const char *key, bool *ret);
+
+int proc_cmdline_get_key_many_internal(ProcCmdlineFlags flags, ...);
+#define proc_cmdline_get_key_many(flags, ...) proc_cmdline_get_key_many_internal(flags, __VA_ARGS__, NULL)
+
+char *proc_cmdline_key_startswith(const char *s, const char *prefix);
+bool proc_cmdline_key_streq(const char *x, const char *y);
+
+int shall_restore_state(void);
+const char* runlevel_to_target(const char *rl);
+
+/* A little helper call, to be used in proc_cmdline_parse_t callbacks */
+static inline bool proc_cmdline_value_missing(const char *key, const char *value) {
+        if (!value) {
+                log_warning("Missing argument for %s= kernel command line switch, ignoring.", key);
+                return true;
+        }
+
+        return false;
+}
diff --git a/src/basic/process-util.c b/src/basic/process-util.c
new file mode 100644
index 0000000..78ce43b
--- /dev/null
+++ b/src/basic/process-util.c
@@ -0,0 +1,1565 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <linux/oom.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/personality.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <syslog.h>
+#include <unistd.h>
+#if HAVE_VALGRIND_VALGRIND_H
+#include <valgrind/valgrind.h>
+#endif
+
+#include "alloc-util.h"
+#include "architecture.h"
+#include "escape.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "ioprio.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "process-util.h"
+#include "raw-clone.h"
+#include "rlimit-util.h"
+#include "signal-util.h"
+#include "stat-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "terminal-util.h"
+#include "user-util.h"
+#include "util.h"
+
+int get_process_state(pid_t pid) {
+        const char *p;
+        char state;
+        int r;
+        _cleanup_free_ char *line = NULL;
+
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "stat");
+
+        r = read_one_line_file(p, &line);
+        if (r == -ENOENT)
+                return -ESRCH;
+        if (r < 0)
+                return r;
+
+        p = strrchr(line, ')');
+        if (!p)
+                return -EIO;
+
+        p++;
+
+        if (sscanf(p, " %c", &state) != 1)
+                return -EIO;
+
+        return (unsigned char) state;
+}
+
+int get_process_comm(pid_t pid, char **ret) {
+        _cleanup_free_ char *escaped = NULL, *comm = NULL;
+        const char *p;
+        int r;
+
+        assert(ret);
+        assert(pid >= 0);
+
+        escaped = new(char, TASK_COMM_LEN);
+        if (!escaped)
+                return -ENOMEM;
+
+        p = procfs_file_alloca(pid, "comm");
+
+        r = read_one_line_file(p, &comm);
+        if (r == -ENOENT)
+                return -ESRCH;
+        if (r < 0)
+                return r;
+
+        /* Escape unprintable characters, just in case, but don't grow the string beyond the underlying size */
+        cellescape(escaped, TASK_COMM_LEN, comm);
+
+        *ret = TAKE_PTR(escaped);
+        return 0;
+}
+
+int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char **line) {
+        _cleanup_fclose_ FILE *f = NULL;
+        bool space = false;
+        char *k;
+        _cleanup_free_ char *ans = NULL;
+        const char *p;
+        int c;
+
+        assert(line);
+        assert(pid >= 0);
+
+        /* Retrieves a process' command line. Replaces unprintable characters while doing so by whitespace (coalescing
+         * multiple sequential ones into one). If max_length is != 0 will return a string of the specified size at most
+         * (the trailing NUL byte does count towards the length here!), abbreviated with a "..." ellipsis. If
+         * comm_fallback is true and the process has no command line set (the case for kernel threads), or has a
+         * command line that resolves to the empty string will return the "comm" name of the process instead.
+         *
+         * Returns -ESRCH if the process doesn't exist, and -ENOENT if the process has no command line (and
+         * comm_fallback is false). Returns 0 and sets *line otherwise. */
+
+        p = procfs_file_alloca(pid, "cmdline");
+
+        f = fopen(p, "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return -ESRCH;
+                return -errno;
+        }
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        if (max_length == 0) {
+                /* This is supposed to be a safety guard against runaway command lines. */
+                long l = sysconf(_SC_ARG_MAX);
+                assert(l > 0);
+                max_length = l;
+        }
+
+        if (max_length == 1) {
+
+                /* If there's only room for one byte, return the empty string */
+                ans = new0(char, 1);
+                if (!ans)
+                        return -ENOMEM;
+
+                *line = TAKE_PTR(ans);
+                return 0;
+
+        } else {
+                bool dotdotdot = false;
+                size_t left;
+
+                ans = new(char, max_length);
+                if (!ans)
+                        return -ENOMEM;
+
+                k = ans;
+                left = max_length;
+                while ((c = getc(f)) != EOF) {
+
+                        if (isprint(c)) {
+
+                                if (space) {
+                                        if (left <= 2) {
+                                                dotdotdot = true;
+                                                break;
+                                        }
+
+                                        *(k++) = ' ';
+                                        left--;
+                                        space = false;
+                                }
+
+                                if (left <= 1) {
+                                        dotdotdot = true;
+                                        break;
+                                }
+
+                                *(k++) = (char) c;
+                                left--;
+                        } else if (k > ans)
+                                space = true;
+                }
+
+                if (dotdotdot) {
+                        if (max_length <= 4) {
+                                k = ans;
+                                left = max_length;
+                        } else {
+                                k = ans + max_length - 4;
+                                left = 4;
+
+                                /* Eat up final spaces */
+                                while (k > ans && isspace(k[-1])) {
+                                        k--;
+                                        left++;
+                                }
+                        }
+
+                        strncpy(k, "...", left-1);
+                        k[left-1] = 0;
+                } else
+                        *k = 0;
+        }
+
+        /* Kernel threads have no argv[] */
+        if (isempty(ans)) {
+                _cleanup_free_ char *t = NULL;
+                int h;
+
+                ans = mfree(ans);
+
+                if (!comm_fallback)
+                        return -ENOENT;
+
+                h = get_process_comm(pid, &t);
+                if (h < 0)
+                        return h;
+
+                size_t l = strlen(t);
+
+                if (l + 3 <= max_length) {
+                        ans = strjoin("[", t, "]");
+                        if (!ans)
+                                return -ENOMEM;
+
+                } else if (max_length <= 6) {
+                        ans = new(char, max_length);
+                        if (!ans)
+                                return -ENOMEM;
+
+                        memcpy(ans, "[...]", max_length-1);
+                        ans[max_length-1] = 0;
+                } else {
+                        t[max_length - 6] = 0;
+
+                        /* Chop off final spaces */
+                        delete_trailing_chars(t, WHITESPACE);
+
+                        ans = strjoin("[", t, "...]");
+                        if (!ans)
+                                return -ENOMEM;
+                }
+
+                *line = TAKE_PTR(ans);
+                return 0;
+        }
+
+        k = realloc(ans, strlen(ans) + 1);
+        if (!k)
+                return -ENOMEM;
+
+        ans = NULL;
+        *line = k;
+
+        return 0;
+}
+
+int rename_process(const char name[]) {
+        static size_t mm_size = 0;
+        static char *mm = NULL;
+        bool truncated = false;
+        size_t l;
+
+        /* This is a like a poor man's setproctitle(). It changes the comm field, argv[0], and also the glibc's
+         * internally used name of the process. For the first one a limit of 16 chars applies; to the second one in
+         * many cases one of 10 (i.e. length of "/sbin/init") — however if we have CAP_SYS_RESOURCES it is unbounded;
+         * to the third one 7 (i.e. the length of "systemd". If you pass a longer string it will likely be
+         * truncated.
+         *
+         * Returns 0 if a name was set but truncated, > 0 if it was set but not truncated. */
+
+        if (isempty(name))
+                return -EINVAL; /* let's not confuse users unnecessarily with an empty name */
+
+        if (!is_main_thread())
+                return -EPERM; /* Let's not allow setting the process name from other threads than the main one, as we
+                                * cache things without locking, and we make assumptions that PR_SET_NAME sets the
+                                * process name that isn't correct on any other threads */
+
+        l = strlen(name);
+
+        /* First step, change the comm field. The main thread's comm is identical to the process comm. This means we
+         * can use PR_SET_NAME, which sets the thread name for the calling thread. */
+        if (prctl(PR_SET_NAME, name) < 0)
+                log_debug_errno(errno, "PR_SET_NAME failed: %m");
+        if (l >= TASK_COMM_LEN) /* Linux process names can be 15 chars at max */
+                truncated = true;
+
+        /* Second step, change glibc's ID of the process name. */
+        if (program_invocation_name) {
+                size_t k;
+
+                k = strlen(program_invocation_name);
+                strncpy(program_invocation_name, name, k);
+                if (l > k)
+                        truncated = true;
+        }
+
+        /* Third step, completely replace the argv[] array the kernel maintains for us. This requires privileges, but
+         * has the advantage that the argv[] array is exactly what we want it to be, and not filled up with zeros at
+         * the end. This is the best option for changing /proc/self/cmdline. */
+
+        /* Let's not bother with this if we don't have euid == 0. Strictly speaking we should check for the
+         * CAP_SYS_RESOURCE capability which is independent of the euid. In our own code the capability generally is
+         * present only for euid == 0, hence let's use this as quick bypass check, to avoid calling mmap() if
+         * PR_SET_MM_ARG_{START,END} fails with EPERM later on anyway. After all geteuid() is dead cheap to call, but
+         * mmap() is not. */
+        if (geteuid() != 0)
+                log_debug("Skipping PR_SET_MM, as we don't have privileges.");
+        else if (mm_size < l+1) {
+                size_t nn_size;
+                char *nn;
+
+                nn_size = PAGE_ALIGN(l+1);
+                nn = mmap(NULL, nn_size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+                if (nn == MAP_FAILED) {
+                        log_debug_errno(errno, "mmap() failed: %m");
+                        goto use_saved_argv;
+                }
+
+                strncpy(nn, name, nn_size);
+
+                /* Now, let's tell the kernel about this new memory */
+                if (prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long) nn, 0, 0) < 0) {
+                        /* HACK: prctl() API is kind of dumb on this point.  The existing end address may already be
+                         * below the desired start address, in which case the kernel may have kicked this back due
+                         * to a range-check failure (see linux/kernel/sys.c:validate_prctl_map() to see this in
+                         * action).  The proper solution would be to have a prctl() API that could set both start+end
+                         * simultaneously, or at least let us query the existing address to anticipate this condition
+                         * and respond accordingly.  For now, we can only guess at the cause of this failure and try
+                         * a workaround--which will briefly expand the arg space to something potentially huge before
+                         * resizing it to what we want. */
+                        log_debug_errno(errno, "PR_SET_MM_ARG_START failed, attempting PR_SET_MM_ARG_END hack: %m");
+
+                        if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) nn + l + 1, 0, 0) < 0) {
+                                log_debug_errno(errno, "PR_SET_MM_ARG_END hack failed, proceeding without: %m");
+                                (void) munmap(nn, nn_size);
+                                goto use_saved_argv;
+                        }
+
+                        if (prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long) nn, 0, 0) < 0) {
+                                log_debug_errno(errno, "PR_SET_MM_ARG_START still failed, proceeding without: %m");
+                                goto use_saved_argv;
+                        }
+                } else {
+                        /* And update the end pointer to the new end, too. If this fails, we don't really know what
+                         * to do, it's pretty unlikely that we can rollback, hence we'll just accept the failure,
+                         * and continue. */
+                        if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) nn + l + 1, 0, 0) < 0)
+                                log_debug_errno(errno, "PR_SET_MM_ARG_END failed, proceeding without: %m");
+                }
+
+                if (mm)
+                        (void) munmap(mm, mm_size);
+
+                mm = nn;
+                mm_size = nn_size;
+        } else {
+                strncpy(mm, name, mm_size);
+
+                /* Update the end pointer, continuing regardless of any failure. */
+                if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) mm + l + 1, 0, 0) < 0)
+                        log_debug_errno(errno, "PR_SET_MM_ARG_END failed, proceeding without: %m");
+        }
+
+use_saved_argv:
+        /* Fourth step: in all cases we'll also update the original argv[], so that our own code gets it right too if
+         * it still looks here */
+
+        if (saved_argc > 0) {
+                int i;
+
+                if (saved_argv[0]) {
+                        size_t k;
+
+                        k = strlen(saved_argv[0]);
+                        strncpy(saved_argv[0], name, k);
+                        if (l > k)
+                                truncated = true;
+                }
+
+                for (i = 1; i < saved_argc; i++) {
+                        if (!saved_argv[i])
+                                break;
+
+                        memzero(saved_argv[i], strlen(saved_argv[i]));
+                }
+        }
+
+        return !truncated;
+}
+
+int is_kernel_thread(pid_t pid) {
+        _cleanup_free_ char *line = NULL;
+        unsigned long long flags;
+        size_t l, i;
+        const char *p;
+        char *q;
+        int r;
+
+        if (IN_SET(pid, 0, 1) || pid == getpid_cached()) /* pid 1, and we ourselves certainly aren't a kernel thread */
+                return 0;
+        if (!pid_is_valid(pid))
+                return -EINVAL;
+
+        p = procfs_file_alloca(pid, "stat");
+        r = read_one_line_file(p, &line);
+        if (r == -ENOENT)
+                return -ESRCH;
+        if (r < 0)
+                return r;
+
+        /* Skip past the comm field */
+        q = strrchr(line, ')');
+        if (!q)
+                return -EINVAL;
+        q++;
+
+        /* Skip 6 fields to reach the flags field */
+        for (i = 0; i < 6; i++) {
+                l = strspn(q, WHITESPACE);
+                if (l < 1)
+                        return -EINVAL;
+                q += l;
+
+                l = strcspn(q, WHITESPACE);
+                if (l < 1)
+                        return -EINVAL;
+                q += l;
+        }
+
+        /* Skip preceding whitespace */
+        l = strspn(q, WHITESPACE);
+        if (l < 1)
+                return -EINVAL;
+        q += l;
+
+        /* Truncate the rest */
+        l = strcspn(q, WHITESPACE);
+        if (l < 1)
+                return -EINVAL;
+        q[l] = 0;
+
+        r = safe_atollu(q, &flags);
+        if (r < 0)
+                return r;
+
+        return !!(flags & PF_KTHREAD);
+}
+
+int get_process_capeff(pid_t pid, char **capeff) {
+        const char *p;
+        int r;
+
+        assert(capeff);
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "status");
+
+        r = get_proc_field(p, "CapEff", WHITESPACE, capeff);
+        if (r == -ENOENT)
+                return -ESRCH;
+
+        return r;
+}
+
+static int get_process_link_contents(const char *proc_file, char **name) {
+        int r;
+
+        assert(proc_file);
+        assert(name);
+
+        r = readlink_malloc(proc_file, name);
+        if (r == -ENOENT)
+                return -ESRCH;
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int get_process_exe(pid_t pid, char **name) {
+        const char *p;
+        char *d;
+        int r;
+
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "exe");
+        r = get_process_link_contents(p, name);
+        if (r < 0)
+                return r;
+
+        d = endswith(*name, " (deleted)");
+        if (d)
+                *d = '\0';
+
+        return 0;
+}
+
+static int get_process_id(pid_t pid, const char *field, uid_t *uid) {
+        _cleanup_fclose_ FILE *f = NULL;
+        const char *p;
+        int r;
+
+        assert(field);
+        assert(uid);
+
+        if (pid < 0)
+                return -EINVAL;
+
+        p = procfs_file_alloca(pid, "status");
+        f = fopen(p, "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return -ESRCH;
+                return -errno;
+        }
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                char *l;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                l = strstrip(line);
+
+                if (startswith(l, field)) {
+                        l += strlen(field);
+                        l += strspn(l, WHITESPACE);
+
+                        l[strcspn(l, WHITESPACE)] = 0;
+
+                        return parse_uid(l, uid);
+                }
+        }
+
+        return -EIO;
+}
+
+int get_process_uid(pid_t pid, uid_t *uid) {
+
+        if (pid == 0 || pid == getpid_cached()) {
+                *uid = getuid();
+                return 0;
+        }
+
+        return get_process_id(pid, "Uid:", uid);
+}
+
+int get_process_gid(pid_t pid, gid_t *gid) {
+
+        if (pid == 0 || pid == getpid_cached()) {
+                *gid = getgid();
+                return 0;
+        }
+
+        assert_cc(sizeof(uid_t) == sizeof(gid_t));
+        return get_process_id(pid, "Gid:", gid);
+}
+
+int get_process_cwd(pid_t pid, char **cwd) {
+        const char *p;
+
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "cwd");
+
+        return get_process_link_contents(p, cwd);
+}
+
+int get_process_root(pid_t pid, char **root) {
+        const char *p;
+
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "root");
+
+        return get_process_link_contents(p, root);
+}
+
+#define ENVIRONMENT_BLOCK_MAX (5U*1024U*1024U)
+
+int get_process_environ(pid_t pid, char **env) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *outcome = NULL;
+        size_t allocated = 0, sz = 0;
+        const char *p;
+        int r;
+
+        assert(pid >= 0);
+        assert(env);
+
+        p = procfs_file_alloca(pid, "environ");
+
+        f = fopen(p, "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return -ESRCH;
+                return -errno;
+        }
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        for (;;) {
+                char c;
+
+                if (sz >= ENVIRONMENT_BLOCK_MAX)
+                        return -ENOBUFS;
+
+                if (!GREEDY_REALLOC(outcome, allocated, sz + 5))
+                        return -ENOMEM;
+
+                r = safe_fgetc(f, &c);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (c == '\0')
+                        outcome[sz++] = '\n';
+                else
+                        sz += cescape_char(c, outcome + sz);
+        }
+
+        outcome[sz] = '\0';
+        *env = TAKE_PTR(outcome);
+
+        return 0;
+}
+
+int get_process_ppid(pid_t pid, pid_t *_ppid) {
+        int r;
+        _cleanup_free_ char *line = NULL;
+        long unsigned ppid;
+        const char *p;
+
+        assert(pid >= 0);
+        assert(_ppid);
+
+        if (pid == 0 || pid == getpid_cached()) {
+                *_ppid = getppid();
+                return 0;
+        }
+
+        p = procfs_file_alloca(pid, "stat");
+        r = read_one_line_file(p, &line);
+        if (r == -ENOENT)
+                return -ESRCH;
+        if (r < 0)
+                return r;
+
+        /* Let's skip the pid and comm fields. The latter is enclosed
+         * in () but does not escape any () in its value, so let's
+         * skip over it manually */
+
+        p = strrchr(line, ')');
+        if (!p)
+                return -EIO;
+
+        p++;
+
+        if (sscanf(p, " "
+                   "%*c "  /* state */
+                   "%lu ", /* ppid */
+                   &ppid) != 1)
+                return -EIO;
+
+        if ((long unsigned) (pid_t) ppid != ppid)
+                return -ERANGE;
+
+        *_ppid = (pid_t) ppid;
+
+        return 0;
+}
+
+int wait_for_terminate(pid_t pid, siginfo_t *status) {
+        siginfo_t dummy;
+
+        assert(pid >= 1);
+
+        if (!status)
+                status = &dummy;
+
+        for (;;) {
+                zero(*status);
+
+                if (waitid(P_PID, pid, status, WEXITED) < 0) {
+
+                        if (errno == EINTR)
+                                continue;
+
+                        return negative_errno();
+                }
+
+                return 0;
+        }
+}
+
+/*
+ * Return values:
+ * < 0 : wait_for_terminate() failed to get the state of the
+ *       process, the process was terminated by a signal, or
+ *       failed for an unknown reason.
+ * >=0 : The process terminated normally, and its exit code is
+ *       returned.
+ *
+ * That is, success is indicated by a return value of zero, and an
+ * error is indicated by a non-zero value.
+ *
+ * A warning is emitted if the process terminates abnormally,
+ * and also if it returns non-zero unless check_exit_code is true.
+ */
+int wait_for_terminate_and_check(const char *name, pid_t pid, WaitFlags flags) {
+        _cleanup_free_ char *buffer = NULL;
+        siginfo_t status;
+        int r, prio;
+
+        assert(pid > 1);
+
+        if (!name) {
+                r = get_process_comm(pid, &buffer);
+                if (r < 0)
+                        log_debug_errno(r, "Failed to acquire process name of " PID_FMT ", ignoring: %m", pid);
+                else
+                        name = buffer;
+        }
+
+        prio = flags & WAIT_LOG_ABNORMAL ? LOG_ERR : LOG_DEBUG;
+
+        r = wait_for_terminate(pid, &status);
+        if (r < 0)
+                return log_full_errno(prio, r, "Failed to wait for %s: %m", strna(name));
+
+        if (status.si_code == CLD_EXITED) {
+                if (status.si_status != EXIT_SUCCESS)
+                        log_full(flags & WAIT_LOG_NON_ZERO_EXIT_STATUS ? LOG_ERR : LOG_DEBUG,
+                                 "%s failed with exit status %i.", strna(name), status.si_status);
+                else
+                        log_debug("%s succeeded.", name);
+
+                return status.si_status;
+
+        } else if (IN_SET(status.si_code, CLD_KILLED, CLD_DUMPED)) {
+
+                log_full(prio, "%s terminated by signal %s.", strna(name), signal_to_string(status.si_status));
+                return -EPROTO;
+        }
+
+        log_full(prio, "%s failed due to unknown reason.", strna(name));
+        return -EPROTO;
+}
+
+/*
+ * Return values:
+ *
+ * < 0 : wait_for_terminate_with_timeout() failed to get the state of the process, the process timed out, the process
+ *       was terminated by a signal, or failed for an unknown reason.
+ *
+ * >=0 : The process terminated normally with no failures.
+ *
+ * Success is indicated by a return value of zero, a timeout is indicated by ETIMEDOUT, and all other child failure
+ * states are indicated by error is indicated by a non-zero value.
+ *
+ * This call assumes SIGCHLD has been blocked already, in particular before the child to wait for has been forked off
+ * to remain entirely race-free.
+ */
+int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout) {
+        sigset_t mask;
+        int r;
+        usec_t until;
+
+        assert_se(sigemptyset(&mask) == 0);
+        assert_se(sigaddset(&mask, SIGCHLD) == 0);
+
+        /* Drop into a sigtimewait-based timeout. Waiting for the
+         * pid to exit. */
+        until = now(CLOCK_MONOTONIC) + timeout;
+        for (;;) {
+                usec_t n;
+                siginfo_t status = {};
+                struct timespec ts;
+
+                n = now(CLOCK_MONOTONIC);
+                if (n >= until)
+                        break;
+
+                r = sigtimedwait(&mask, NULL, timespec_store(&ts, until - n)) < 0 ? -errno : 0;
+                /* Assuming we woke due to the child exiting. */
+                if (waitid(P_PID, pid, &status, WEXITED|WNOHANG) == 0) {
+                        if (status.si_pid == pid) {
+                                /* This is the correct child.*/
+                                if (status.si_code == CLD_EXITED)
+                                        return (status.si_status == 0) ? 0 : -EPROTO;
+                                else
+                                        return -EPROTO;
+                        }
+                }
+                /* Not the child, check for errors and proceed appropriately */
+                if (r < 0) {
+                        switch (r) {
+                        case -EAGAIN:
+                                /* Timed out, child is likely hung. */
+                                return -ETIMEDOUT;
+                        case -EINTR:
+                                /* Received a different signal and should retry */
+                                continue;
+                        default:
+                                /* Return any unexpected errors */
+                                return r;
+                        }
+                }
+        }
+
+        return -EPROTO;
+}
+
+void sigkill_wait(pid_t pid) {
+        assert(pid > 1);
+
+        if (kill(pid, SIGKILL) >= 0)
+                (void) wait_for_terminate(pid, NULL);
+}
+
+void sigkill_waitp(pid_t *pid) {
+        PROTECT_ERRNO;
+
+        if (!pid)
+                return;
+        if (*pid <= 1)
+                return;
+
+        sigkill_wait(*pid);
+}
+
+void sigterm_wait(pid_t pid) {
+        assert(pid > 1);
+
+        if (kill_and_sigcont(pid, SIGTERM) >= 0)
+                (void) wait_for_terminate(pid, NULL);
+}
+
+int kill_and_sigcont(pid_t pid, int sig) {
+        int r;
+
+        r = kill(pid, sig) < 0 ? -errno : 0;
+
+        /* If this worked, also send SIGCONT, unless we already just sent a SIGCONT, or SIGKILL was sent which isn't
+         * affected by a process being suspended anyway. */
+        if (r >= 0 && !IN_SET(sig, SIGCONT, SIGKILL))
+                (void) kill(pid, SIGCONT);
+
+        return r;
+}
+
+int getenv_for_pid(pid_t pid, const char *field, char **ret) {
+        _cleanup_fclose_ FILE *f = NULL;
+        char *value = NULL;
+        const char *path;
+        size_t l, sum = 0;
+        int r;
+
+        assert(pid >= 0);
+        assert(field);
+        assert(ret);
+
+        if (pid == 0 || pid == getpid_cached()) {
+                const char *e;
+
+                e = getenv(field);
+                if (!e) {
+                        *ret = NULL;
+                        return 0;
+                }
+
+                value = strdup(e);
+                if (!value)
+                        return -ENOMEM;
+
+                *ret = value;
+                return 1;
+        }
+
+        if (!pid_is_valid(pid))
+                return -EINVAL;
+
+        path = procfs_file_alloca(pid, "environ");
+
+        f = fopen(path, "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return -ESRCH;
+
+                return -errno;
+        }
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        l = strlen(field);
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+
+                if (sum > ENVIRONMENT_BLOCK_MAX) /* Give up searching eventually */
+                        return -ENOBUFS;
+
+                r = read_nul_string(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)  /* EOF */
+                        break;
+
+                sum += r;
+
+                if (strneq(line, field, l) && line[l] == '=') {
+                        value = strdup(line + l + 1);
+                        if (!value)
+                                return -ENOMEM;
+
+                        *ret = value;
+                        return 1;
+                }
+        }
+
+        *ret = NULL;
+        return 0;
+}
+
+bool pid_is_unwaited(pid_t pid) {
+        /* Checks whether a PID is still valid at all, including a zombie */
+
+        if (pid < 0)
+                return false;
+
+        if (pid <= 1) /* If we or PID 1 would be dead and have been waited for, this code would not be running */
+                return true;
+
+        if (pid == getpid_cached())
+                return true;
+
+        if (kill(pid, 0) >= 0)
+                return true;
+
+        return errno != ESRCH;
+}
+
+bool pid_is_alive(pid_t pid) {
+        int r;
+
+        /* Checks whether a PID is still valid and not a zombie */
+
+        if (pid < 0)
+                return false;
+
+        if (pid <= 1) /* If we or PID 1 would be a zombie, this code would not be running */
+                return true;
+
+        if (pid == getpid_cached())
+                return true;
+
+        r = get_process_state(pid);
+        if (IN_SET(r, -ESRCH, 'Z'))
+                return false;
+
+        return true;
+}
+
+int pid_from_same_root_fs(pid_t pid) {
+        const char *root;
+
+        if (pid < 0)
+                return false;
+
+        if (pid == 0 || pid == getpid_cached())
+                return true;
+
+        root = procfs_file_alloca(pid, "root");
+
+        return files_same(root, "/proc/1/root", 0);
+}
+
+bool is_main_thread(void) {
+        static thread_local int cached = 0;
+
+        if (_unlikely_(cached == 0))
+                cached = getpid_cached() == gettid() ? 1 : -1;
+
+        return cached > 0;
+}
+
+_noreturn_ void freeze(void) {
+
+        log_close();
+
+        /* Make sure nobody waits for us on a socket anymore */
+        close_all_fds(NULL, 0);
+
+        sync();
+
+        /* Let's not freeze right away, but keep reaping zombies. */
+        for (;;) {
+                int r;
+                siginfo_t si = {};
+
+                r = waitid(P_ALL, 0, &si, WEXITED);
+                if (r < 0 && errno != EINTR)
+                        break;
+        }
+
+        /* waitid() failed with an unexpected error, things are really borked. Freeze now! */
+        for (;;)
+                pause();
+}
+
+bool oom_score_adjust_is_valid(int oa) {
+        return oa >= OOM_SCORE_ADJ_MIN && oa <= OOM_SCORE_ADJ_MAX;
+}
+
+unsigned long personality_from_string(const char *p) {
+        int architecture;
+
+        if (!p)
+                return PERSONALITY_INVALID;
+
+        /* Parse a personality specifier. We use our own identifiers that indicate specific ABIs, rather than just
+         * hints regarding the register size, since we want to keep things open for multiple locally supported ABIs for
+         * the same register size. */
+
+        architecture = architecture_from_string(p);
+        if (architecture < 0)
+                return PERSONALITY_INVALID;
+
+        if (architecture == native_architecture())
+                return PER_LINUX;
+#ifdef SECONDARY_ARCHITECTURE
+        if (architecture == SECONDARY_ARCHITECTURE)
+                return PER_LINUX32;
+#endif
+
+        return PERSONALITY_INVALID;
+}
+
+const char* personality_to_string(unsigned long p) {
+        int architecture = _ARCHITECTURE_INVALID;
+
+        if (p == PER_LINUX)
+                architecture = native_architecture();
+#ifdef SECONDARY_ARCHITECTURE
+        else if (p == PER_LINUX32)
+                architecture = SECONDARY_ARCHITECTURE;
+#endif
+
+        if (architecture < 0)
+                return NULL;
+
+        return architecture_to_string(architecture);
+}
+
+int safe_personality(unsigned long p) {
+        int ret;
+
+        /* So here's the deal, personality() is weirdly defined by glibc. In some cases it returns a failure via errno,
+         * and in others as negative return value containing an errno-like value. Let's work around this: this is a
+         * wrapper that uses errno if it is set, and uses the return value otherwise. And then it sets both errno and
+         * the return value indicating the same issue, so that we are definitely on the safe side.
+         *
+         * See https://github.com/systemd/systemd/issues/6737 */
+
+        errno = 0;
+        ret = personality(p);
+        if (ret < 0) {
+                if (errno != 0)
+                        return -errno;
+
+                errno = -ret;
+        }
+
+        return ret;
+}
+
+int opinionated_personality(unsigned long *ret) {
+        int current;
+
+        /* Returns the current personality, or PERSONALITY_INVALID if we can't determine it. This function is a bit
+         * opinionated though, and ignores all the finer-grained bits and exotic personalities, only distinguishing the
+         * two most relevant personalities: PER_LINUX and PER_LINUX32. */
+
+        current = safe_personality(PERSONALITY_INVALID);
+        if (current < 0)
+                return current;
+
+        if (((unsigned long) current & 0xffff) == PER_LINUX32)
+                *ret = PER_LINUX32;
+        else
+                *ret = PER_LINUX;
+
+        return 0;
+}
+
+void valgrind_summary_hack(void) {
+#if HAVE_VALGRIND_VALGRIND_H
+        if (getpid_cached() == 1 && RUNNING_ON_VALGRIND) {
+                pid_t pid;
+                pid = raw_clone(SIGCHLD);
+                if (pid < 0)
+                        log_emergency_errno(errno, "Failed to fork off valgrind helper: %m");
+                else if (pid == 0)
+                        exit(EXIT_SUCCESS);
+                else {
+                        log_info("Spawned valgrind helper as PID "PID_FMT".", pid);
+                        (void) wait_for_terminate(pid, NULL);
+                }
+        }
+#endif
+}
+
+int pid_compare_func(const pid_t *a, const pid_t *b) {
+        /* Suitable for usage in qsort() */
+        return CMP(*a, *b);
+}
+
+int ioprio_parse_priority(const char *s, int *ret) {
+        int i, r;
+
+        assert(s);
+        assert(ret);
+
+        r = safe_atoi(s, &i);
+        if (r < 0)
+                return r;
+
+        if (!ioprio_priority_is_valid(i))
+                return -EINVAL;
+
+        *ret = i;
+        return 0;
+}
+
+/* The cached PID, possible values:
+ *
+ *     == UNSET [0]  → cache not initialized yet
+ *     == BUSY [-1]  → some thread is initializing it at the moment
+ *     any other     → the cached PID
+ */
+
+#define CACHED_PID_UNSET ((pid_t) 0)
+#define CACHED_PID_BUSY ((pid_t) -1)
+
+static pid_t cached_pid = CACHED_PID_UNSET;
+
+void reset_cached_pid(void) {
+        /* Invoked in the child after a fork(), i.e. at the first moment the PID changed */
+        cached_pid = CACHED_PID_UNSET;
+}
+
+/* We use glibc __register_atfork() + __dso_handle directly here, as they are not included in the glibc
+ * headers. __register_atfork() is mostly equivalent to pthread_atfork(), but doesn't require us to link against
+ * libpthread, as it is part of glibc anyway. */
+extern int __register_atfork(void (*prepare) (void), void (*parent) (void), void (*child) (void), void *dso_handle);
+extern void* __dso_handle _weak_;
+
+pid_t getpid_cached(void) {
+        static bool installed = false;
+        pid_t current_value;
+
+        /* getpid_cached() is much like getpid(), but caches the value in local memory, to avoid having to invoke a
+         * system call each time. This restores glibc behaviour from before 2.24, when getpid() was unconditionally
+         * cached. Starting with 2.24 getpid() started to become prohibitively expensive when used for detecting when
+         * objects were used across fork()s. With this caching the old behaviour is somewhat restored.
+         *
+         * https://bugzilla.redhat.com/show_bug.cgi?id=1443976
+         * https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=c579f48edba88380635ab98cb612030e3ed8691e
+         */
+
+        current_value = __sync_val_compare_and_swap(&cached_pid, CACHED_PID_UNSET, CACHED_PID_BUSY);
+
+        switch (current_value) {
+
+        case CACHED_PID_UNSET: { /* Not initialized yet, then do so now */
+                pid_t new_pid;
+
+                new_pid = raw_getpid();
+
+                if (!installed) {
+                        /* __register_atfork() either returns 0 or -ENOMEM, in its glibc implementation. Since it's
+                         * only half-documented (glibc doesn't document it but LSB does — though only superficially)
+                         * we'll check for errors only in the most generic fashion possible. */
+
+                        if (__register_atfork(NULL, NULL, reset_cached_pid, __dso_handle) != 0) {
+                                /* OOM? Let's try again later */
+                                cached_pid = CACHED_PID_UNSET;
+                                return new_pid;
+                        }
+
+                        installed = true;
+                }
+
+                cached_pid = new_pid;
+                return new_pid;
+        }
+
+        case CACHED_PID_BUSY: /* Somebody else is currently initializing */
+                return raw_getpid();
+
+        default: /* Properly initialized */
+                return current_value;
+        }
+}
+
+int must_be_root(void) {
+
+        if (geteuid() == 0)
+                return 0;
+
+        return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Need to be root.");
+}
+
+int safe_fork_full(
+                const char *name,
+                const int except_fds[],
+                size_t n_except_fds,
+                ForkFlags flags,
+                pid_t *ret_pid) {
+
+        pid_t original_pid, pid;
+        sigset_t saved_ss, ss;
+        bool block_signals = false;
+        int prio, r;
+
+        /* A wrapper around fork(), that does a couple of important initializations in addition to mere forking. Always
+         * returns the child's PID in *ret_pid. Returns == 0 in the child, and > 0 in the parent. */
+
+        prio = flags & FORK_LOG ? LOG_ERR : LOG_DEBUG;
+
+        original_pid = getpid_cached();
+
+        if (flags & (FORK_RESET_SIGNALS|FORK_DEATHSIG)) {
+                /* We temporarily block all signals, so that the new child has them blocked initially. This way, we can
+                 * be sure that SIGTERMs are not lost we might send to the child. */
+
+                assert_se(sigfillset(&ss) >= 0);
+                block_signals = true;
+
+        } else if (flags & FORK_WAIT) {
+                /* Let's block SIGCHLD at least, so that we can safely watch for the child process */
+
+                assert_se(sigemptyset(&ss) >= 0);
+                assert_se(sigaddset(&ss, SIGCHLD) >= 0);
+                block_signals = true;
+        }
+
+        if (block_signals)
+                if (sigprocmask(SIG_SETMASK, &ss, &saved_ss) < 0)
+                        return log_full_errno(prio, errno, "Failed to set signal mask: %m");
+
+        if (flags & FORK_NEW_MOUNTNS)
+                pid = raw_clone(SIGCHLD|CLONE_NEWNS);
+        else
+                pid = fork();
+        if (pid < 0) {
+                r = -errno;
+
+                if (block_signals) /* undo what we did above */
+                        (void) sigprocmask(SIG_SETMASK, &saved_ss, NULL);
+
+                return log_full_errno(prio, r, "Failed to fork: %m");
+        }
+        if (pid > 0) {
+                /* We are in the parent process */
+
+                log_debug("Successfully forked off '%s' as PID " PID_FMT ".", strna(name), pid);
+
+                if (flags & FORK_WAIT) {
+                        r = wait_for_terminate_and_check(name, pid, (flags & FORK_LOG ? WAIT_LOG : 0));
+                        if (r < 0)
+                                return r;
+                        if (r != EXIT_SUCCESS) /* exit status > 0 should be treated as failure, too */
+                                return -EPROTO;
+                }
+
+                if (block_signals) /* undo what we did above */
+                        (void) sigprocmask(SIG_SETMASK, &saved_ss, NULL);
+
+                if (ret_pid)
+                        *ret_pid = pid;
+
+                return 1;
+        }
+
+        /* We are in the child process */
+
+        if (flags & FORK_REOPEN_LOG) {
+                /* Close the logs if requested, before we log anything. And make sure we reopen it if needed. */
+                log_close();
+                log_set_open_when_needed(true);
+        }
+
+        if (name) {
+                r = rename_process(name);
+                if (r < 0)
+                        log_full_errno(flags & FORK_LOG ? LOG_WARNING : LOG_DEBUG,
+                                       r, "Failed to rename process, ignoring: %m");
+        }
+
+        if (flags & FORK_DEATHSIG)
+                if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0) {
+                        log_full_errno(prio, errno, "Failed to set death signal: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+        if (flags & FORK_RESET_SIGNALS) {
+                r = reset_all_signal_handlers();
+                if (r < 0) {
+                        log_full_errno(prio, r, "Failed to reset signal handlers: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                /* This implicitly undoes the signal mask stuff we did before the fork()ing above */
+                r = reset_signal_mask();
+                if (r < 0) {
+                        log_full_errno(prio, r, "Failed to reset signal mask: %m");
+                        _exit(EXIT_FAILURE);
+                }
+        } else if (block_signals) { /* undo what we did above */
+                if (sigprocmask(SIG_SETMASK, &saved_ss, NULL) < 0) {
+                        log_full_errno(prio, errno, "Failed to restore signal mask: %m");
+                        _exit(EXIT_FAILURE);
+                }
+        }
+
+        if (flags & FORK_DEATHSIG) {
+                pid_t ppid;
+                /* Let's see if the parent PID is still the one we started from? If not, then the parent
+                 * already died by the time we set PR_SET_PDEATHSIG, hence let's emulate the effect */
+
+                ppid = getppid();
+                if (ppid == 0)
+                        /* Parent is in a differn't PID namespace. */;
+                else if (ppid != original_pid) {
+                        log_debug("Parent died early, raising SIGTERM.");
+                        (void) raise(SIGTERM);
+                        _exit(EXIT_FAILURE);
+                }
+        }
+
+        if (FLAGS_SET(flags, FORK_NEW_MOUNTNS | FORK_MOUNTNS_SLAVE)) {
+
+                /* Optionally, make sure we never propagate mounts to the host. */
+
+                if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0) {
+                        log_full_errno(prio, errno, "Failed to remount root directory as MS_SLAVE: %m");
+                        _exit(EXIT_FAILURE);
+                }
+        }
+
+        if (flags & FORK_CLOSE_ALL_FDS) {
+                /* Close the logs here in case it got reopened above, as close_all_fds() would close them for us */
+                log_close();
+
+                r = close_all_fds(except_fds, n_except_fds);
+                if (r < 0) {
+                        log_full_errno(prio, r, "Failed to close all file descriptors: %m");
+                        _exit(EXIT_FAILURE);
+                }
+        }
+
+        /* When we were asked to reopen the logs, do so again now */
+        if (flags & FORK_REOPEN_LOG) {
+                log_open();
+                log_set_open_when_needed(false);
+        }
+
+        if (flags & FORK_NULL_STDIO) {
+                r = make_null_stdio();
+                if (r < 0) {
+                        log_full_errno(prio, r, "Failed to connect stdin/stdout to /dev/null: %m");
+                        _exit(EXIT_FAILURE);
+                }
+        }
+
+        if (flags & FORK_RLIMIT_NOFILE_SAFE) {
+                r = rlimit_nofile_safe();
+                if (r < 0) {
+                        log_full_errno(prio, r, "Failed to lower RLIMIT_NOFILE's soft limit to 1K: %m");
+                        _exit(EXIT_FAILURE);
+                }
+        }
+
+        if (ret_pid)
+                *ret_pid = getpid_cached();
+
+        return 0;
+}
+
+int namespace_fork(
+                const char *outer_name,
+                const char *inner_name,
+                const int except_fds[],
+                size_t n_except_fds,
+                ForkFlags flags,
+                int pidns_fd,
+                int mntns_fd,
+                int netns_fd,
+                int userns_fd,
+                int root_fd,
+                pid_t *ret_pid) {
+
+        int r;
+
+        /* This is much like safe_fork(), but forks twice, and joins the specified namespaces in the middle
+         * process. This ensures that we are fully a member of the destination namespace, with pidns an all, so that
+         * /proc/self/fd works correctly. */
+
+        r = safe_fork_full(outer_name, except_fds, n_except_fds, (flags|FORK_DEATHSIG) & ~(FORK_REOPEN_LOG|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE), ret_pid);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                pid_t pid;
+
+                /* Child */
+
+                r = namespace_enter(pidns_fd, mntns_fd, netns_fd, userns_fd, root_fd);
+                if (r < 0) {
+                        log_full_errno(FLAGS_SET(flags, FORK_LOG) ? LOG_ERR : LOG_DEBUG, r, "Failed to join namespace: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                /* We mask a few flags here that either make no sense for the grandchild, or that we don't have to do again */
+                r = safe_fork_full(inner_name, except_fds, n_except_fds, flags & ~(FORK_WAIT|FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_NULL_STDIO), &pid);
+                if (r < 0)
+                        _exit(EXIT_FAILURE);
+                if (r == 0) {
+                        /* Child */
+                        if (ret_pid)
+                                *ret_pid = pid;
+                        return 0;
+                }
+
+                r = wait_for_terminate_and_check(inner_name, pid, FLAGS_SET(flags, FORK_LOG) ? WAIT_LOG : 0);
+                if (r < 0)
+                        _exit(EXIT_FAILURE);
+
+                _exit(r);
+        }
+
+        return 1;
+}
+
+int fork_agent(const char *name, const int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) {
+        bool stdout_is_tty, stderr_is_tty;
+        size_t n, i;
+        va_list ap;
+        char **l;
+        int r;
+
+        assert(path);
+
+        /* Spawns a temporary TTY agent, making sure it goes away when we go away */
+
+        r = safe_fork_full(name, except, n_except, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_CLOSE_ALL_FDS, ret_pid);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return 0;
+
+        /* In the child: */
+
+        stdout_is_tty = isatty(STDOUT_FILENO);
+        stderr_is_tty = isatty(STDERR_FILENO);
+
+        if (!stdout_is_tty || !stderr_is_tty) {
+                int fd;
+
+                /* Detach from stdout/stderr. and reopen
+                 * /dev/tty for them. This is important to
+                 * ensure that when systemctl is started via
+                 * popen() or a similar call that expects to
+                 * read EOF we actually do generate EOF and
+                 * not delay this indefinitely by because we
+                 * keep an unused copy of stdin around. */
+                fd = open("/dev/tty", O_WRONLY);
+                if (fd < 0) {
+                        log_error_errno(errno, "Failed to open /dev/tty: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (!stdout_is_tty && dup2(fd, STDOUT_FILENO) < 0) {
+                        log_error_errno(errno, "Failed to dup2 /dev/tty: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                if (!stderr_is_tty && dup2(fd, STDERR_FILENO) < 0) {
+                        log_error_errno(errno, "Failed to dup2 /dev/tty: %m");
+                        _exit(EXIT_FAILURE);
+                }
+
+                safe_close_above_stdio(fd);
+        }
+
+        (void) rlimit_nofile_safe();
+
+        /* Count arguments */
+        va_start(ap, path);
+        for (n = 0; va_arg(ap, char*); n++)
+                ;
+        va_end(ap);
+
+        /* Allocate strv */
+        l = newa(char*, n + 1);
+
+        /* Fill in arguments */
+        va_start(ap, path);
+        for (i = 0; i <= n; i++)
+                l[i] = va_arg(ap, char*);
+        va_end(ap);
+
+        execv(path, l);
+        _exit(EXIT_FAILURE);
+}
+
+int set_oom_score_adjust(int value) {
+        char t[DECIMAL_STR_MAX(int)];
+
+        sprintf(t, "%i", value);
+
+        return write_string_file("/proc/self/oom_score_adj", t,
+                                 WRITE_STRING_FILE_VERIFY_ON_FAILURE|WRITE_STRING_FILE_DISABLE_BUFFER);
+}
+
+static const char *const ioprio_class_table[] = {
+        [IOPRIO_CLASS_NONE] = "none",
+        [IOPRIO_CLASS_RT] = "realtime",
+        [IOPRIO_CLASS_BE] = "best-effort",
+        [IOPRIO_CLASS_IDLE] = "idle"
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ioprio_class, int, IOPRIO_N_CLASSES);
+
+static const char *const sigchld_code_table[] = {
+        [CLD_EXITED] = "exited",
+        [CLD_KILLED] = "killed",
+        [CLD_DUMPED] = "dumped",
+        [CLD_TRAPPED] = "trapped",
+        [CLD_STOPPED] = "stopped",
+        [CLD_CONTINUED] = "continued",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(sigchld_code, int);
+
+static const char* const sched_policy_table[] = {
+        [SCHED_OTHER] = "other",
+        [SCHED_BATCH] = "batch",
+        [SCHED_IDLE] = "idle",
+        [SCHED_FIFO] = "fifo",
+        [SCHED_RR] = "rr"
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(sched_policy, int, INT_MAX);
diff --git a/src/basic/process-util.h b/src/basic/process-util.h
new file mode 100644
index 0000000..c85ea30
--- /dev/null
+++ b/src/basic/process-util.h
@@ -0,0 +1,194 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <alloca.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+
+#include "format-util.h"
+#include "ioprio.h"
+#include "macro.h"
+#include "time-util.h"
+
+#define procfs_file_alloca(pid, field)                                  \
+        ({                                                              \
+                pid_t _pid_ = (pid);                                    \
+                const char *_r_;                                        \
+                if (_pid_ == 0) {                                       \
+                        _r_ = ("/proc/self/" field);                    \
+                } else {                                                \
+                        _r_ = newa(char, STRLEN("/proc/") + DECIMAL_STR_MAX(pid_t) + 1 + sizeof(field)); \
+                        sprintf((char*) _r_, "/proc/"PID_FMT"/" field, _pid_); \
+                }                                                       \
+                _r_;                                                    \
+        })
+
+int get_process_state(pid_t pid);
+int get_process_comm(pid_t pid, char **name);
+int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char **line);
+int get_process_exe(pid_t pid, char **name);
+int get_process_uid(pid_t pid, uid_t *uid);
+int get_process_gid(pid_t pid, gid_t *gid);
+int get_process_capeff(pid_t pid, char **capeff);
+int get_process_cwd(pid_t pid, char **cwd);
+int get_process_root(pid_t pid, char **root);
+int get_process_environ(pid_t pid, char **environ);
+int get_process_ppid(pid_t pid, pid_t *ppid);
+
+int wait_for_terminate(pid_t pid, siginfo_t *status);
+
+typedef enum WaitFlags {
+        WAIT_LOG_ABNORMAL             = 1 << 0,
+        WAIT_LOG_NON_ZERO_EXIT_STATUS = 1 << 1,
+
+        /* A shortcut for requesting the most complete logging */
+        WAIT_LOG = WAIT_LOG_ABNORMAL|WAIT_LOG_NON_ZERO_EXIT_STATUS,
+} WaitFlags;
+
+int wait_for_terminate_and_check(const char *name, pid_t pid, WaitFlags flags);
+int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout);
+
+void sigkill_wait(pid_t pid);
+void sigkill_waitp(pid_t *pid);
+void sigterm_wait(pid_t pid);
+
+int kill_and_sigcont(pid_t pid, int sig);
+
+int rename_process(const char name[]);
+int is_kernel_thread(pid_t pid);
+
+int getenv_for_pid(pid_t pid, const char *field, char **_value);
+
+bool pid_is_alive(pid_t pid);
+bool pid_is_unwaited(pid_t pid);
+int pid_from_same_root_fs(pid_t pid);
+
+bool is_main_thread(void);
+
+_noreturn_ void freeze(void);
+
+bool oom_score_adjust_is_valid(int oa);
+
+#ifndef PERSONALITY_INVALID
+/* personality(7) documents that 0xffffffffUL is used for querying the
+ * current personality, hence let's use that here as error
+ * indicator. */
+#define PERSONALITY_INVALID 0xffffffffLU
+#endif
+
+unsigned long personality_from_string(const char *p);
+const char *personality_to_string(unsigned long);
+
+int safe_personality(unsigned long p);
+int opinionated_personality(unsigned long *ret);
+
+int ioprio_class_to_string_alloc(int i, char **s);
+int ioprio_class_from_string(const char *s);
+
+const char *sigchld_code_to_string(int i) _const_;
+int sigchld_code_from_string(const char *s) _pure_;
+
+int sched_policy_to_string_alloc(int i, char **s);
+int sched_policy_from_string(const char *s);
+
+static inline pid_t PTR_TO_PID(const void *p) {
+        return (pid_t) ((uintptr_t) p);
+}
+
+static inline void* PID_TO_PTR(pid_t pid) {
+        return (void*) ((uintptr_t) pid);
+}
+
+void valgrind_summary_hack(void);
+
+int pid_compare_func(const pid_t *a, const pid_t *b);
+
+static inline bool nice_is_valid(int n) {
+        return n >= PRIO_MIN && n < PRIO_MAX;
+}
+
+static inline bool sched_policy_is_valid(int i) {
+        return IN_SET(i, SCHED_OTHER, SCHED_BATCH, SCHED_IDLE, SCHED_FIFO, SCHED_RR);
+}
+
+static inline bool sched_priority_is_valid(int i) {
+        return i >= 0 && i <= sched_get_priority_max(SCHED_RR);
+}
+
+static inline bool ioprio_class_is_valid(int i) {
+        return IN_SET(i, IOPRIO_CLASS_NONE, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE);
+}
+
+static inline bool ioprio_priority_is_valid(int i) {
+        return i >= 0 && i < IOPRIO_BE_NR;
+}
+
+static inline bool pid_is_valid(pid_t p) {
+        return p > 0;
+}
+
+int ioprio_parse_priority(const char *s, int *ret);
+
+pid_t getpid_cached(void);
+void reset_cached_pid(void);
+
+int must_be_root(void);
+
+typedef enum ForkFlags {
+        FORK_RESET_SIGNALS      = 1 << 0, /* Reset all signal handlers and signal mask */
+        FORK_CLOSE_ALL_FDS      = 1 << 1, /* Close all open file descriptors in the child, except for 0,1,2 */
+        FORK_DEATHSIG           = 1 << 2, /* Set PR_DEATHSIG in the child */
+        FORK_NULL_STDIO         = 1 << 3, /* Connect 0,1,2 to /dev/null */
+        FORK_REOPEN_LOG         = 1 << 4, /* Reopen log connection */
+        FORK_LOG                = 1 << 5, /* Log above LOG_DEBUG log level about failures */
+        FORK_WAIT               = 1 << 6, /* Wait until child exited */
+        FORK_NEW_MOUNTNS        = 1 << 7, /* Run child in its own mount namespace */
+        FORK_MOUNTNS_SLAVE      = 1 << 8, /* Make child's mount namespace MS_SLAVE */
+        FORK_RLIMIT_NOFILE_SAFE = 1 << 9, /* Set RLIMIT_NOFILE soft limit to 1K for select() compat */
+} ForkFlags;
+
+int safe_fork_full(const char *name, const int except_fds[], size_t n_except_fds, ForkFlags flags, pid_t *ret_pid);
+
+static inline int safe_fork(const char *name, ForkFlags flags, pid_t *ret_pid) {
+        return safe_fork_full(name, NULL, 0, flags, ret_pid);
+}
+
+int namespace_fork(const char *outer_name, const char *inner_name, const int except_fds[], size_t n_except_fds, ForkFlags flags, int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd, pid_t *ret_pid);
+
+int fork_agent(const char *name, const int except[], size_t n_except, pid_t *pid, const char *path, ...) _sentinel_;
+
+int set_oom_score_adjust(int value);
+
+#if SIZEOF_PID_T == 4
+/* The highest possibly (theoretic) pid_t value on this architecture. */
+#define PID_T_MAX ((pid_t) INT32_MAX)
+/* The maximum number of concurrent processes Linux allows on this architecture, as well as the highest valid PID value
+ * the kernel will potentially assign. This reflects a value compiled into the kernel (PID_MAX_LIMIT), and sets the
+ * upper boundary on what may be written to the /proc/sys/kernel/pid_max sysctl (but do note that the sysctl is off by
+ * 1, since PID 0 can never exist and there can hence only be one process less than the limit would suggest). Since
+ * these values are documented in proc(5) we feel quite confident that they are stable enough for the near future at
+ * least to define them here too. */
+#define TASKS_MAX 4194303U
+#elif SIZEOF_PID_T == 2
+#define PID_T_MAX ((pid_t) INT16_MAX)
+#define TASKS_MAX 32767U
+#else
+#error "Unknown pid_t size"
+#endif
+
+assert_cc(TASKS_MAX <= (unsigned long) PID_T_MAX)
+
+/* Like TAKE_PTR() but for child PIDs, resetting them to 0 */
+#define TAKE_PID(pid)                           \
+        ({                                      \
+                pid_t _pid_ = (pid);            \
+                (pid) = 0;                      \
+                _pid_;                          \
+        })
diff --git a/src/basic/procfs-util.c b/src/basic/procfs-util.c
new file mode 100644
index 0000000..7aaf95b
--- /dev/null
+++ b/src/basic/procfs-util.c
@@ -0,0 +1,268 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+
+#include "alloc-util.h"
+#include "def.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "parse-util.h"
+#include "process-util.h"
+#include "procfs-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+
+int procfs_tasks_get_limit(uint64_t *ret) {
+        _cleanup_free_ char *value = NULL;
+        uint64_t pid_max, threads_max;
+        int r;
+
+        assert(ret);
+
+        /* So there are two sysctl files that control the system limit of processes:
+         *
+         * 1. kernel.threads-max: this is probably the sysctl that makes more sense, as it directly puts a limit on
+         *    concurrent tasks.
+         *
+         * 2. kernel.pid_max: this limits the numeric range PIDs can take, and thus indirectly also limits the number
+         *    of concurrent threads. AFAICS it's primarily a compatibility concept: some crappy old code used a signed
+         *    16bit type for PIDs, hence the kernel provides a way to ensure the PIDs never go beyond INT16_MAX by
+         *    default.
+         *
+         * By default #2 is set to much lower values than #1, hence the limit people come into contact with first, as
+         * it's the lowest boundary they need to bump when they want higher number of processes.
+         *
+         * Also note the weird definition of #2: PIDs assigned will be kept below this value, which means the number of
+         * tasks that can be created is one lower, as PID 0 is not a valid process ID. */
+
+        r = read_one_line_file("/proc/sys/kernel/pid_max", &value);
+        if (r < 0)
+                return r;
+
+        r = safe_atou64(value, &pid_max);
+        if (r < 0)
+                return r;
+
+        value = mfree(value);
+        r = read_one_line_file("/proc/sys/kernel/threads-max", &value);
+        if (r < 0)
+                return r;
+
+        r = safe_atou64(value, &threads_max);
+        if (r < 0)
+                return r;
+
+        /* Subtract one from pid_max, since PID 0 is not a valid PID */
+        *ret = MIN(pid_max-1, threads_max);
+        return 0;
+}
+
+int procfs_tasks_set_limit(uint64_t limit) {
+        char buffer[DECIMAL_STR_MAX(uint64_t)+1];
+        _cleanup_free_ char *value = NULL;
+        uint64_t pid_max;
+        int r;
+
+        if (limit == 0) /* This makes no sense, we are userspace and hence count as tasks too, and we want to live,
+                         * hence the limit conceptually has to be above 0. Also, most likely if anyone asks for a zero
+                         * limit he/she probably means "no limit", hence let's better refuse this to avoid
+                         * confusion. */
+                return -EINVAL;
+
+        /* The Linux kernel doesn't allow this value to go below 20, hence don't allow this either, higher values than
+         * TASKS_MAX are not accepted by the pid_max sysctl. We'll treat anything this high as "unbounded" and hence
+         * set it to the maximum. */
+        limit = CLAMP(limit, 20U, TASKS_MAX);
+
+        r = read_one_line_file("/proc/sys/kernel/pid_max", &value);
+        if (r < 0)
+                return r;
+        r = safe_atou64(value, &pid_max);
+        if (r < 0)
+                return r;
+
+        /* As pid_max is about the numeric pid_t range we'll bump it if necessary, but only ever increase it, never
+         * decrease it, as threads-max is the much more relevant sysctl. */
+        if (limit > pid_max-1) {
+                sprintf(buffer, "%" PRIu64, limit+1); /* Add one, since PID 0 is not a valid PID */
+                r = write_string_file("/proc/sys/kernel/pid_max", buffer, WRITE_STRING_FILE_DISABLE_BUFFER);
+                if (r < 0)
+                        return r;
+        }
+
+        sprintf(buffer, "%" PRIu64, limit);
+        r = write_string_file("/proc/sys/kernel/threads-max", buffer, WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0) {
+                uint64_t threads_max;
+
+                /* Hmm, we couldn't write this? If so, maybe it was already set properly? In that case let's not
+                 * generate an error */
+
+                value = mfree(value);
+                if (read_one_line_file("/proc/sys/kernel/threads-max", &value) < 0)
+                        return r; /* return original error */
+
+                if (safe_atou64(value, &threads_max) < 0)
+                        return r; /* return original error */
+
+                if (MIN(pid_max-1, threads_max) != limit)
+                        return r; /* return original error */
+
+                /* Yay! Value set already matches what we were trying to set, hence consider this a success. */
+        }
+
+        return 0;
+}
+
+int procfs_tasks_get_current(uint64_t *ret) {
+        _cleanup_free_ char *value = NULL;
+        const char *p, *nr;
+        size_t n;
+        int r;
+
+        assert(ret);
+
+        r = read_one_line_file("/proc/loadavg", &value);
+        if (r < 0)
+                return r;
+
+        /* Look for the second part of the fourth field, which is separated by a slash from the first part. None of the
+         * earlier fields use a slash, hence let's use this to find the right spot. */
+        p = strchr(value, '/');
+        if (!p)
+                return -EINVAL;
+
+        p++;
+        n = strspn(p, DIGITS);
+        nr = strndupa(p, n);
+
+        return safe_atou64(nr, ret);
+}
+
+static uint64_t calc_gcd64(uint64_t a, uint64_t b) {
+
+        while (b > 0) {
+                uint64_t t;
+
+                t = a % b;
+
+                a = b;
+                b = t;
+        }
+
+        return a;
+}
+
+int procfs_cpu_get_usage(nsec_t *ret) {
+        _cleanup_free_ char *first_line = NULL;
+        unsigned long user_ticks, nice_ticks, system_ticks, irq_ticks, softirq_ticks,
+                guest_ticks = 0, guest_nice_ticks = 0;
+        long ticks_per_second;
+        uint64_t sum, gcd, a, b;
+        const char *p;
+        int r;
+
+        assert(ret);
+
+        r = read_one_line_file("/proc/stat", &first_line);
+        if (r < 0)
+                return r;
+
+        p = first_word(first_line, "cpu");
+        if (!p)
+                return -EINVAL;
+
+        if (sscanf(p, "%lu %lu %lu %*u %*u %lu %lu %*u %lu %lu",
+                   &user_ticks,
+                   &nice_ticks,
+                   &system_ticks,
+                   &irq_ticks,
+                   &softirq_ticks,
+                   &guest_ticks,
+                   &guest_nice_ticks) < 5) /* we only insist on the first five fields */
+                return -EINVAL;
+
+        ticks_per_second = sysconf(_SC_CLK_TCK);
+        if (ticks_per_second  < 0)
+                return -errno;
+        assert(ticks_per_second > 0);
+
+        sum = (uint64_t) user_ticks + (uint64_t) nice_ticks + (uint64_t) system_ticks +
+                (uint64_t) irq_ticks + (uint64_t) softirq_ticks +
+                (uint64_t) guest_ticks + (uint64_t) guest_nice_ticks;
+
+        /* Let's reduce this fraction before we apply it to avoid overflows when converting this to µsec */
+        gcd = calc_gcd64(NSEC_PER_SEC, ticks_per_second);
+
+        a = (uint64_t) NSEC_PER_SEC / gcd;
+        b = (uint64_t) ticks_per_second / gcd;
+
+        *ret = DIV_ROUND_UP((nsec_t) sum * (nsec_t) a, (nsec_t) b);
+        return 0;
+}
+
+int procfs_memory_get(uint64_t *ret_total, uint64_t *ret_used) {
+        uint64_t mem_total = UINT64_MAX, mem_free = UINT64_MAX;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        f = fopen("/proc/meminfo", "re");
+        if (!f)
+                return -errno;
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                uint64_t *v;
+                char *p, *e;
+                size_t n;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return -EINVAL; /* EOF: Couldn't find one or both fields? */
+
+                p = first_word(line, "MemTotal:");
+                if (p)
+                        v = &mem_total;
+                else {
+                        p = first_word(line, "MemFree:");
+                        if (p)
+                                v = &mem_free;
+                        else
+                                continue;
+                }
+
+                /* Determine length of numeric value */
+                n = strspn(p, DIGITS);
+                if (n == 0)
+                        return -EINVAL;
+                e = p + n;
+
+                /* Ensure the line ends in " kB" */
+                n = strspn(e, WHITESPACE);
+                if (n == 0)
+                        return -EINVAL;
+                if (!streq(e + n, "kB"))
+                        return -EINVAL;
+
+                *e = 0;
+                r = safe_atou64(p, v);
+                if (r < 0)
+                        return r;
+                if (*v == UINT64_MAX)
+                        return -EINVAL;
+
+                if (mem_total != UINT64_MAX && mem_free != UINT64_MAX)
+                        break;
+        }
+
+        if (mem_free > mem_total)
+                return -EINVAL;
+
+        if (ret_total)
+                *ret_total = mem_total * 1024U;
+        if (ret_used)
+                *ret_used = (mem_total - mem_free) * 1024U;
+        return 0;
+}
diff --git a/src/basic/procfs-util.h b/src/basic/procfs-util.h
new file mode 100644
index 0000000..5a44e9e
--- /dev/null
+++ b/src/basic/procfs-util.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+
+#include "time-util.h"
+
+int procfs_tasks_get_limit(uint64_t *ret);
+int procfs_tasks_set_limit(uint64_t limit);
+int procfs_tasks_get_current(uint64_t *ret);
+
+int procfs_cpu_get_usage(nsec_t *ret);
+
+int procfs_memory_get(uint64_t *ret_total, uint64_t *ret_used);
+static inline int procfs_memory_get_used(uint64_t *ret) {
+        return procfs_memory_get(NULL, ret);
+}
diff --git a/src/basic/random-util.c b/src/basic/random-util.c
new file mode 100644
index 0000000..f7decf6
--- /dev/null
+++ b/src/basic/random-util.c
@@ -0,0 +1,265 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#if defined(__i386__) || defined(__x86_64__)
+#include <cpuid.h>
+#endif
+
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+#if HAVE_SYS_AUXV_H
+#  include <sys/auxv.h>
+#endif
+
+#if USE_SYS_RANDOM_H
+#  include <sys/random.h>
+#else
+#  include <linux/random.h>
+#endif
+
+#include "fd-util.h"
+#include "io-util.h"
+#include "missing.h"
+#include "random-util.h"
+#include "time-util.h"
+
+#if HAS_FEATURE_MEMORY_SANITIZER
+#include <sanitizer/msan_interface.h>
+#endif
+
+int rdrand(unsigned long *ret) {
+
+#if defined(__i386__) || defined(__x86_64__)
+        static int have_rdrand = -1;
+        unsigned char err;
+
+        if (have_rdrand < 0) {
+                uint32_t eax, ebx, ecx, edx;
+
+                /* Check if RDRAND is supported by the CPU */
+                if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) == 0) {
+                        have_rdrand = false;
+                        return -EOPNOTSUPP;
+                }
+
+                have_rdrand = !!(ecx & (1U << 30));
+        }
+
+        if (have_rdrand == 0)
+                return -EOPNOTSUPP;
+
+        asm volatile("rdrand %0;"
+                     "setc %1"
+                     : "=r" (*ret),
+                       "=qm" (err));
+
+#if HAS_FEATURE_MEMORY_SANITIZER
+        __msan_unpoison(&err, sizeof(err));
+#endif
+
+        if (!err)
+                return -EAGAIN;
+
+        return 0;
+#else
+        return -EOPNOTSUPP;
+#endif
+}
+
+int genuine_random_bytes(void *p, size_t n, RandomFlags flags) {
+        static int have_syscall = -1;
+        _cleanup_close_ int fd = -1;
+        bool got_some = false;
+        int r;
+
+        /* Gathers some randomness from the kernel (or the CPU if the RANDOM_ALLOW_RDRAND flag is set). This call won't
+         * block, unless the RANDOM_BLOCK flag is set. If RANDOM_DONT_DRAIN is set, an error is returned if the random
+         * pool is not initialized. Otherwise it will always return some data from the kernel, regardless of whether
+         * the random pool is fully initialized or not. */
+
+        if (n == 0)
+                return 0;
+
+        if (FLAGS_SET(flags, RANDOM_ALLOW_RDRAND))
+                /* Try x86-64' RDRAND intrinsic if we have it. We only use it if high quality randomness is not
+                 * required, as we don't trust it (who does?). Note that we only do a single iteration of RDRAND here,
+                 * even though the Intel docs suggest calling this in a tight loop of 10 invocations or so. That's
+                 * because we don't really care about the quality here. We generally prefer using RDRAND if the caller
+                 * allows us too, since this way we won't drain the kernel randomness pool if we don't need it, as the
+                 * pool's entropy is scarce. */
+                for (;;) {
+                        unsigned long u;
+                        size_t m;
+
+                        if (rdrand(&u) < 0) {
+                                if (got_some && FLAGS_SET(flags, RANDOM_EXTEND_WITH_PSEUDO)) {
+                                        /* Fill in the remaining bytes using pseudo-random values */
+                                        pseudo_random_bytes(p, n);
+                                        return 0;
+                                }
+
+                                /* OK, this didn't work, let's go to getrandom() + /dev/urandom instead */
+                                break;
+                        }
+
+                        m = MIN(sizeof(u), n);
+                        memcpy(p, &u, m);
+
+                        p = (uint8_t*) p + m;
+                        n -= m;
+
+                        if (n == 0)
+                                return 0; /* Yay, success! */
+
+                        got_some = true;
+                }
+
+        /* Use the getrandom() syscall unless we know we don't have it. */
+        if (have_syscall != 0 && !HAS_FEATURE_MEMORY_SANITIZER) {
+
+                for (;;) {
+                        r = getrandom(p, n, FLAGS_SET(flags, RANDOM_BLOCK) ? 0 : GRND_NONBLOCK);
+                        if (r > 0) {
+                                have_syscall = true;
+
+                                if ((size_t) r == n)
+                                        return 0; /* Yay, success! */
+
+                                assert((size_t) r < n);
+                                p = (uint8_t*) p + r;
+                                n -= r;
+
+                                if (FLAGS_SET(flags, RANDOM_EXTEND_WITH_PSEUDO)) {
+                                        /* Fill in the remaining bytes using pseudo-random values */
+                                        pseudo_random_bytes(p, n);
+                                        return 0;
+                                }
+
+                                got_some = true;
+
+                                /* Hmm, we didn't get enough good data but the caller insists on good data? Then try again */
+                                if (FLAGS_SET(flags, RANDOM_BLOCK))
+                                        continue;
+
+                                /* Fill in the rest with /dev/urandom */
+                                break;
+
+                        } else if (r == 0) {
+                                have_syscall = true;
+                                return -EIO;
+
+                        } else if (errno == ENOSYS) {
+                                /* We lack the syscall, continue with reading from /dev/urandom. */
+                                have_syscall = false;
+                                break;
+
+                        } else if (errno == EAGAIN) {
+                                /* The kernel has no entropy whatsoever. Let's remember to use the syscall the next
+                                 * time again though.
+                                 *
+                                 * If RANDOM_DONT_DRAIN is set, return an error so that random_bytes() can produce some
+                                 * pseudo-random bytes instead. Otherwise, fall back to /dev/urandom, which we know is empty,
+                                 * but the kernel will produce some bytes for us on a best-effort basis. */
+                                have_syscall = true;
+
+                                if (got_some && FLAGS_SET(flags, RANDOM_EXTEND_WITH_PSEUDO)) {
+                                        /* Fill in the remaining bytes using pseudorandom values */
+                                        pseudo_random_bytes(p, n);
+                                        return 0;
+                                }
+
+                                if (FLAGS_SET(flags, RANDOM_DONT_DRAIN))
+                                        return -ENODATA;
+
+                                /* Use /dev/urandom instead */
+                                break;
+                        } else
+                                return -errno;
+                }
+        }
+
+        fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+        if (fd < 0)
+                return errno == ENOENT ? -ENOSYS : -errno;
+
+        return loop_read_exact(fd, p, n, true);
+}
+
+void initialize_srand(void) {
+        static bool srand_called = false;
+        unsigned x;
+#if HAVE_SYS_AUXV_H
+        const void *auxv;
+#endif
+        unsigned long k;
+
+        if (srand_called)
+                return;
+
+#if HAVE_SYS_AUXV_H
+        /* The kernel provides us with 16 bytes of entropy in auxv, so let's
+         * try to make use of that to seed the pseudo-random generator. It's
+         * better than nothing... */
+
+        auxv = (const void*) getauxval(AT_RANDOM);
+        if (auxv) {
+                assert_cc(sizeof(x) <= 16);
+                memcpy(&x, auxv, sizeof(x));
+        } else
+#endif
+                x = 0;
+
+        x ^= (unsigned) now(CLOCK_REALTIME);
+        x ^= (unsigned) gettid();
+
+        if (rdrand(&k) >= 0)
+                x ^= (unsigned) k;
+
+        srand(x);
+        srand_called = true;
+}
+
+/* INT_MAX gives us only 31 bits, so use 24 out of that. */
+#if RAND_MAX >= INT_MAX
+#  define RAND_STEP 3
+#else
+/* SHORT_INT_MAX or lower gives at most 15 bits, we just just 8 out of that. */
+#  define RAND_STEP 1
+#endif
+
+void pseudo_random_bytes(void *p, size_t n) {
+        uint8_t *q;
+
+        initialize_srand();
+
+        for (q = p; q < (uint8_t*) p + n; q += RAND_STEP) {
+                unsigned rr;
+
+                rr = (unsigned) rand();
+
+#if RAND_STEP >= 3
+                if ((size_t) (q - (uint8_t*) p + 2) < n)
+                        q[2] = rr >> 16;
+#endif
+#if RAND_STEP >= 2
+                if ((size_t) (q - (uint8_t*) p + 1) < n)
+                        q[1] = rr >> 8;
+#endif
+                q[0] = rr;
+        }
+}
+
+void random_bytes(void *p, size_t n) {
+
+        if (genuine_random_bytes(p, n, RANDOM_EXTEND_WITH_PSEUDO|RANDOM_DONT_DRAIN|RANDOM_ALLOW_RDRAND) >= 0)
+                return;
+
+        /* If for some reason some user made /dev/urandom unavailable to us, or the kernel has no entropy, use a PRNG instead. */
+        pseudo_random_bytes(p, n);
+}
diff --git a/src/basic/random-util.h b/src/basic/random-util.h
new file mode 100644
index 0000000..3e8c288
--- /dev/null
+++ b/src/basic/random-util.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef enum RandomFlags {
+        RANDOM_EXTEND_WITH_PSEUDO = 1 << 0, /* If we can't get enough genuine randomness, but some, fill up the rest with pseudo-randomness */
+        RANDOM_BLOCK              = 1 << 1, /* Rather block than return crap randomness (only if the kernel supports that) */
+        RANDOM_DONT_DRAIN         = 1 << 2, /* If we can't get any randomness at all, return early with -EAGAIN */
+        RANDOM_ALLOW_RDRAND       = 1 << 3, /* Allow usage of the CPU RNG */
+} RandomFlags;
+
+int genuine_random_bytes(void *p, size_t n, RandomFlags flags); /* returns "genuine" randomness, optionally filled upwith pseudo random, if not enough is available */
+void pseudo_random_bytes(void *p, size_t n);                    /* returns only pseudo-randommess (but possibly seeded from something better) */
+void random_bytes(void *p, size_t n);                           /* returns genuine randomness if cheaply available, and pseudo randomness if not. */
+
+void initialize_srand(void);
+
+static inline uint64_t random_u64(void) {
+        uint64_t u;
+        random_bytes(&u, sizeof(u));
+        return u;
+}
+
+static inline uint32_t random_u32(void) {
+        uint32_t u;
+        random_bytes(&u, sizeof(u));
+        return u;
+}
+
+int rdrand(unsigned long *ret);
diff --git a/src/basic/ratelimit.c b/src/basic/ratelimit.c
new file mode 100644
index 0000000..4e04e04
--- /dev/null
+++ b/src/basic/ratelimit.c
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <sys/time.h>
+
+#include "macro.h"
+#include "ratelimit.h"
+
+/* Modelled after Linux' lib/ratelimit.c by Dave Young
+ * <hidave.darkstar@gmail.com>, which is licensed GPLv2. */
+
+bool ratelimit_below(RateLimit *r) {
+        usec_t ts;
+
+        assert(r);
+
+        if (r->interval <= 0 || r->burst <= 0)
+                return true;
+
+        ts = now(CLOCK_MONOTONIC);
+
+        if (r->begin <= 0 ||
+            r->begin + r->interval < ts) {
+                r->begin = ts;
+
+                /* Reset counter */
+                r->num = 0;
+                goto good;
+        }
+
+        if (r->num < r->burst)
+                goto good;
+
+        return false;
+
+good:
+        r->num++;
+        return true;
+}
diff --git a/src/basic/ratelimit.h b/src/basic/ratelimit.h
new file mode 100644
index 0000000..de91def
--- /dev/null
+++ b/src/basic/ratelimit.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "time-util.h"
+#include "util.h"
+
+typedef struct RateLimit {
+        usec_t interval;
+        usec_t begin;
+        unsigned burst;
+        unsigned num;
+} RateLimit;
+
+#define RATELIMIT_DEFINE(_name, _interval, _burst)       \
+        RateLimit _name = {                              \
+                .interval = (_interval),                 \
+                .burst = (_burst),                       \
+                .num = 0,                                \
+                .begin = 0                               \
+        }
+
+#define RATELIMIT_INIT(v, _interval, _burst)             \
+        do {                                             \
+                RateLimit *_r = &(v);                    \
+                _r->interval = (_interval);              \
+                _r->burst = (_burst);                    \
+                _r->num = 0;                             \
+                _r->begin = 0;                           \
+        } while (false)
+
+#define RATELIMIT_RESET(v)                               \
+        do {                                             \
+                RateLimit *_r = &(v);                    \
+                _r->num = 0;                             \
+                _r->begin = 0;                           \
+        } while (false)
+
+bool ratelimit_below(RateLimit *r);
diff --git a/src/basic/raw-clone.h b/src/basic/raw-clone.h
new file mode 100644
index 0000000..b8857b0
--- /dev/null
+++ b/src/basic/raw-clone.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/***
+  Copyright © 2016 Michael Karcher
+***/
+
+#include <errno.h>
+#include <sched.h>
+#include <sys/syscall.h>
+
+#include "log.h"
+#include "macro.h"
+
+/**
+ * raw_clone() - uses clone to create a new process with clone flags
+ * @flags: Flags to pass to the clone system call
+ *
+ * Uses the clone system call to create a new process with the cloning flags and termination signal passed in the flags
+ * parameter. Opposed to glibc's clone funtion, using this function does not set up a separate stack for the child, but
+ * relies on copy-on-write semantics on the one stack at a common virtual address, just as fork does.
+ *
+ * To obtain copy-on-write semantics, flags must not contain CLONE_VM, and thus CLONE_THREAD and CLONE_SIGHAND (which
+ * require CLONE_VM) are not usable.
+ *
+ * Additionally, as this function does not pass the ptid, newtls and ctid parameters to the kernel, flags must not
+ * contain CLONE_PARENT_SETTID, CLONE_CHILD_SETTID, CLONE_CHILD_CLEARTID or CLONE_SETTLS.
+ *
+ * Returns: 0 in the child process and the child process id in the parent.
+ */
+static inline pid_t raw_clone(unsigned long flags) {
+        pid_t ret;
+
+        assert((flags & (CLONE_VM|CLONE_PARENT_SETTID|CLONE_CHILD_SETTID|
+                         CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0);
+#if defined(__s390x__) || defined(__s390__) || defined(__CRIS__)
+        /* On s390/s390x and cris the order of the first and second arguments
+         * of the raw clone() system call is reversed. */
+        ret = (pid_t) syscall(__NR_clone, NULL, flags);
+#elif defined(__sparc__)
+        {
+                /**
+                 * sparc always returns the other process id in %o0, and
+                 * a boolean flag whether this is the child or the parent in
+                 * %o1. Inline assembly is needed to get the flag returned
+                 * in %o1.
+                 */
+                int in_child, child_pid, error;
+
+                asm volatile("mov %3, %%g1\n\t"
+                             "mov %4, %%o0\n\t"
+                             "mov 0 , %%o1\n\t"
+#if defined(__arch64__)
+                             "t 0x6d\n\t"
+#else
+                             "t 0x10\n\t"
+#endif
+                             "addx %%g0, 0, %2\n\t"
+                             "mov %%o1, %0\n\t"
+                             "mov %%o0, %1" :
+                             "=r"(in_child), "=r"(child_pid), "=r"(error) :
+                             "i"(__NR_clone), "r"(flags) :
+                             "%o1", "%o0", "%g1", "cc" );
+
+                if (error) {
+                        errno = child_pid;
+                        ret = -1;
+                } else
+                        ret = in_child ? 0 : child_pid;
+        }
+#else
+        ret = (pid_t) syscall(__NR_clone, flags, NULL);
+#endif
+
+        if (ret == 0)
+                reset_cached_pid();
+
+        return ret;
+}
diff --git a/src/basic/raw-reboot.h b/src/basic/raw-reboot.h
new file mode 100644
index 0000000..8ecefe9
--- /dev/null
+++ b/src/basic/raw-reboot.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <linux/reboot.h>
+#include <sys/reboot.h>
+#include <sys/syscall.h>
+
+/* glibc defines the reboot() API call, which is a wrapper around the system call of the same name, but without the
+ * extra "arg" parameter. Since we need that parameter for some calls, let's add a "raw" wrapper that is defined the
+ * same way, except it takes the additional argument. */
+
+static inline int raw_reboot(int cmd, const void *arg) {
+        return (int) syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, arg);
+}
diff --git a/src/basic/refcnt.h b/src/basic/refcnt.h
new file mode 100644
index 0000000..40f9a84
--- /dev/null
+++ b/src/basic/refcnt.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/* A type-safe atomic refcounter.
+ *
+ * DO NOT USE THIS UNLESS YOU ACTUALLY CARE ABOUT THREAD SAFETY! */
+
+typedef struct {
+        volatile unsigned _value;
+} RefCount;
+
+#define REFCNT_GET(r) ((r)._value)
+#define REFCNT_INC(r) (__sync_add_and_fetch(&(r)._value, 1))
+#define REFCNT_DEC(r) (__sync_sub_and_fetch(&(r)._value, 1))
+
+#define REFCNT_INIT ((RefCount) { ._value = 1 })
+
+#define _DEFINE_ATOMIC_REF_FUNC(type, name, scope)                    \
+        scope type *name##_ref(type *p) {                               \
+                if (!p)                                                 \
+                        return NULL;                                    \
+                                                                        \
+                assert_se(REFCNT_INC(p->n_ref) >= 2);                   \
+                return p;                                               \
+        }
+
+#define _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func, scope)       \
+        scope type *name##_unref(type *p) {                             \
+                if (!p)                                                 \
+                        return NULL;                                    \
+                                                                        \
+                if (REFCNT_DEC(p->n_ref) > 0)                           \
+                        return NULL;                                    \
+                                                                        \
+                return free_func(p);                                    \
+        }
+
+#define DEFINE_ATOMIC_REF_FUNC(type, name)    \
+        _DEFINE_ATOMIC_REF_FUNC(type, name,)
+#define DEFINE_PUBLIC_ATOMIC_REF_FUNC(type, name)     \
+        _DEFINE_ATOMIC_REF_FUNC(type, name, _public_)
+
+#define DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func)       \
+        _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func,)
+#define DEFINE_PUBLIC_ATOMIC_UNREF_FUNC(type, name, free_func)        \
+        _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func, _public_)
+
+#define DEFINE_ATOMIC_REF_UNREF_FUNC(type, name, free_func)   \
+        DEFINE_ATOMIC_REF_FUNC(type, name);                   \
+        DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func);
+
+#define DEFINE_PUBLIC_ATOMIC_REF_UNREF_FUNC(type, name, free_func)   \
+        DEFINE_PUBLIC_ATOMIC_REF_FUNC(type, name);                   \
+        DEFINE_PUBLIC_ATOMIC_UNREF_FUNC(type, name, free_func);
diff --git a/src/basic/replace-var.c b/src/basic/replace-var.c
new file mode 100644
index 0000000..fd2b5c1
--- /dev/null
+++ b/src/basic/replace-var.c
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "macro.h"
+#include "replace-var.h"
+#include "string-util.h"
+
+/*
+ * Generic infrastructure for replacing @FOO@ style variables in
+ * strings. Will call a callback for each replacement.
+ */
+
+static int get_variable(const char *b, char **r) {
+        size_t k;
+        char *t;
+
+        assert(b);
+        assert(r);
+
+        if (*b != '@')
+                return 0;
+
+        k = strspn(b + 1, UPPERCASE_LETTERS "_");
+        if (k <= 0 || b[k+1] != '@')
+                return 0;
+
+        t = strndup(b + 1, k);
+        if (!t)
+                return -ENOMEM;
+
+        *r = t;
+        return 1;
+}
+
+char *replace_var(const char *text, char *(*lookup)(const char *variable, void *userdata), void *userdata) {
+        char *r, *t;
+        const char *f;
+        size_t l;
+
+        assert(text);
+        assert(lookup);
+
+        l = strlen(text);
+        r = new(char, l+1);
+        if (!r)
+                return NULL;
+
+        f = text;
+        t = r;
+        while (*f) {
+                _cleanup_free_ char *v = NULL, *n = NULL;
+                char *a;
+                int k;
+                size_t skip, d, nl;
+
+                k = get_variable(f, &v);
+                if (k < 0)
+                        goto oom;
+                if (k == 0) {
+                        *(t++) = *(f++);
+                        continue;
+                }
+
+                n = lookup(v, userdata);
+                if (!n)
+                        goto oom;
+
+                skip = strlen(v) + 2;
+
+                d = t - r;
+                nl = l - skip + strlen(n);
+                a = realloc(r, nl + 1);
+                if (!a)
+                        goto oom;
+
+                l = nl;
+                r = a;
+                t = r + d;
+
+                t = stpcpy(t, n);
+                f += skip;
+        }
+
+        *t = 0;
+        return r;
+
+oom:
+        return mfree(r);
+}
diff --git a/src/basic/replace-var.h b/src/basic/replace-var.h
new file mode 100644
index 0000000..e6a489f
--- /dev/null
+++ b/src/basic/replace-var.h
@@ -0,0 +1,4 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+char *replace_var(const char *text, char *(*lookup)(const char *variable, void *userdata), void *userdata);
diff --git a/src/basic/rlimit-util.c b/src/basic/rlimit-util.c
new file mode 100644
index 0000000..74b3a02
--- /dev/null
+++ b/src/basic/rlimit-util.c
@@ -0,0 +1,410 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <sys/resource.h>
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "rlimit-util.h"
+#include "string-table.h"
+#include "time-util.h"
+
+int setrlimit_closest(int resource, const struct rlimit *rlim) {
+        struct rlimit highest, fixed;
+
+        assert(rlim);
+
+        if (setrlimit(resource, rlim) >= 0)
+                return 0;
+
+        if (errno != EPERM)
+                return -errno;
+
+        /* So we failed to set the desired setrlimit, then let's try
+         * to get as close as we can */
+        if (getrlimit(resource, &highest) < 0)
+                return -errno;
+
+        /* If the hard limit is unbounded anyway, then the EPERM had other reasons, let's propagate the original EPERM
+         * then */
+        if (highest.rlim_max == RLIM_INFINITY)
+                return -EPERM;
+
+        fixed = (struct rlimit) {
+                .rlim_cur = MIN(rlim->rlim_cur, highest.rlim_max),
+                .rlim_max = MIN(rlim->rlim_max, highest.rlim_max),
+        };
+
+        /* Shortcut things if we wouldn't change anything. */
+        if (fixed.rlim_cur == highest.rlim_cur &&
+            fixed.rlim_max == highest.rlim_max)
+                return 0;
+
+        if (setrlimit(resource, &fixed) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int setrlimit_closest_all(const struct rlimit *const *rlim, int *which_failed) {
+        int i, r;
+
+        assert(rlim);
+
+        /* On failure returns the limit's index that failed in *which_failed, but only if non-NULL */
+
+        for (i = 0; i < _RLIMIT_MAX; i++) {
+                if (!rlim[i])
+                        continue;
+
+                r = setrlimit_closest(i, rlim[i]);
+                if (r < 0) {
+                        if (which_failed)
+                                *which_failed = i;
+
+                        return r;
+                }
+        }
+
+        if (which_failed)
+                *which_failed = -1;
+
+        return 0;
+}
+
+static int rlimit_parse_u64(const char *val, rlim_t *ret) {
+        uint64_t u;
+        int r;
+
+        assert(val);
+        assert(ret);
+
+        if (streq(val, "infinity")) {
+                *ret = RLIM_INFINITY;
+                return 0;
+        }
+
+        /* setrlimit(2) suggests rlim_t is always 64bit on Linux. */
+        assert_cc(sizeof(rlim_t) == sizeof(uint64_t));
+
+        r = safe_atou64(val, &u);
+        if (r < 0)
+                return r;
+        if (u >= (uint64_t) RLIM_INFINITY)
+                return -ERANGE;
+
+        *ret = (rlim_t) u;
+        return 0;
+}
+
+static int rlimit_parse_size(const char *val, rlim_t *ret) {
+        uint64_t u;
+        int r;
+
+        assert(val);
+        assert(ret);
+
+        if (streq(val, "infinity")) {
+                *ret = RLIM_INFINITY;
+                return 0;
+        }
+
+        r = parse_size(val, 1024, &u);
+        if (r < 0)
+                return r;
+        if (u >= (uint64_t) RLIM_INFINITY)
+                return -ERANGE;
+
+        *ret = (rlim_t) u;
+        return 0;
+}
+
+static int rlimit_parse_sec(const char *val, rlim_t *ret) {
+        uint64_t u;
+        usec_t t;
+        int r;
+
+        assert(val);
+        assert(ret);
+
+        if (streq(val, "infinity")) {
+                *ret = RLIM_INFINITY;
+                return 0;
+        }
+
+        r = parse_sec(val, &t);
+        if (r < 0)
+                return r;
+        if (t == USEC_INFINITY) {
+                *ret = RLIM_INFINITY;
+                return 0;
+        }
+
+        u = (uint64_t) DIV_ROUND_UP(t, USEC_PER_SEC);
+        if (u >= (uint64_t) RLIM_INFINITY)
+                return -ERANGE;
+
+        *ret = (rlim_t) u;
+        return 0;
+}
+
+static int rlimit_parse_usec(const char *val, rlim_t *ret) {
+        usec_t t;
+        int r;
+
+        assert(val);
+        assert(ret);
+
+        if (streq(val, "infinity")) {
+                *ret = RLIM_INFINITY;
+                return 0;
+        }
+
+        r = parse_time(val, &t, 1);
+        if (r < 0)
+                return r;
+        if (t == USEC_INFINITY) {
+                *ret = RLIM_INFINITY;
+                return 0;
+        }
+
+        *ret = (rlim_t) t;
+        return 0;
+}
+
+static int rlimit_parse_nice(const char *val, rlim_t *ret) {
+        uint64_t rl;
+        int r;
+
+        /* So, Linux is weird. The range for RLIMIT_NICE is 40..1, mapping to the nice levels -20..19. However, the
+         * RLIMIT_NICE limit defaults to 0 by the kernel, i.e. a value that maps to nice level 20, which of course is
+         * bogus and does not exist. In order to permit parsing the RLIMIT_NICE of 0 here we hence implement a slight
+         * asymmetry: when parsing as positive nice level we permit 0..19. When parsing as negative nice level, we
+         * permit -20..0. But when parsing as raw resource limit value then we also allow the special value 0.
+         *
+         * Yeah, Linux is quality engineering sometimes... */
+
+        if (val[0] == '+') {
+
+                /* Prefixed with "+": Parse as positive user-friendly nice value */
+                r = safe_atou64(val + 1, &rl);
+                if (r < 0)
+                        return r;
+
+                if (rl >= PRIO_MAX)
+                        return -ERANGE;
+
+                rl = 20 - rl;
+
+        } else if (val[0] == '-') {
+
+                /* Prefixed with "-": Parse as negative user-friendly nice value */
+                r = safe_atou64(val + 1, &rl);
+                if (r < 0)
+                        return r;
+
+                if (rl > (uint64_t) (-PRIO_MIN))
+                        return -ERANGE;
+
+                rl = 20 + rl;
+        } else {
+
+                /* Not prefixed: parse as raw resource limit value */
+                r = safe_atou64(val, &rl);
+                if (r < 0)
+                        return r;
+
+                if (rl > (uint64_t) (20 - PRIO_MIN))
+                        return -ERANGE;
+        }
+
+        *ret = (rlim_t) rl;
+        return 0;
+}
+
+static int (*const rlimit_parse_table[_RLIMIT_MAX])(const char *val, rlim_t *ret) = {
+        [RLIMIT_CPU] = rlimit_parse_sec,
+        [RLIMIT_FSIZE] = rlimit_parse_size,
+        [RLIMIT_DATA] = rlimit_parse_size,
+        [RLIMIT_STACK] = rlimit_parse_size,
+        [RLIMIT_CORE] = rlimit_parse_size,
+        [RLIMIT_RSS] = rlimit_parse_size,
+        [RLIMIT_NOFILE] = rlimit_parse_u64,
+        [RLIMIT_AS] = rlimit_parse_size,
+        [RLIMIT_NPROC] = rlimit_parse_u64,
+        [RLIMIT_MEMLOCK] = rlimit_parse_size,
+        [RLIMIT_LOCKS] = rlimit_parse_u64,
+        [RLIMIT_SIGPENDING] = rlimit_parse_u64,
+        [RLIMIT_MSGQUEUE] = rlimit_parse_size,
+        [RLIMIT_NICE] = rlimit_parse_nice,
+        [RLIMIT_RTPRIO] = rlimit_parse_u64,
+        [RLIMIT_RTTIME] = rlimit_parse_usec,
+};
+
+int rlimit_parse_one(int resource, const char *val, rlim_t *ret) {
+        assert(val);
+        assert(ret);
+
+        if (resource < 0)
+                return -EINVAL;
+        if (resource >= _RLIMIT_MAX)
+                return -EINVAL;
+
+        return rlimit_parse_table[resource](val, ret);
+}
+
+int rlimit_parse(int resource, const char *val, struct rlimit *ret) {
+        _cleanup_free_ char *hard = NULL, *soft = NULL;
+        rlim_t hl, sl;
+        int r;
+
+        assert(val);
+        assert(ret);
+
+        r = extract_first_word(&val, &soft, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -EINVAL;
+
+        r = rlimit_parse_one(resource, soft, &sl);
+        if (r < 0)
+                return r;
+
+        r = extract_first_word(&val, &hard, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (!isempty(val))
+                return -EINVAL;
+        if (r == 0)
+                hl = sl;
+        else {
+                r = rlimit_parse_one(resource, hard, &hl);
+                if (r < 0)
+                        return r;
+                if (sl > hl)
+                        return -EILSEQ;
+        }
+
+        *ret = (struct rlimit) {
+                .rlim_cur = sl,
+                .rlim_max = hl,
+        };
+
+        return 0;
+}
+
+int rlimit_format(const struct rlimit *rl, char **ret) {
+        char *s = NULL;
+
+        assert(rl);
+        assert(ret);
+
+        if (rl->rlim_cur >= RLIM_INFINITY && rl->rlim_max >= RLIM_INFINITY)
+                s = strdup("infinity");
+        else if (rl->rlim_cur >= RLIM_INFINITY)
+                (void) asprintf(&s, "infinity:" RLIM_FMT, rl->rlim_max);
+        else if (rl->rlim_max >= RLIM_INFINITY)
+                (void) asprintf(&s, RLIM_FMT ":infinity", rl->rlim_cur);
+        else if (rl->rlim_cur == rl->rlim_max)
+                (void) asprintf(&s, RLIM_FMT, rl->rlim_cur);
+        else
+                (void) asprintf(&s, RLIM_FMT ":" RLIM_FMT, rl->rlim_cur, rl->rlim_max);
+
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+static const char* const rlimit_table[_RLIMIT_MAX] = {
+        [RLIMIT_AS]         = "AS",
+        [RLIMIT_CORE]       = "CORE",
+        [RLIMIT_CPU]        = "CPU",
+        [RLIMIT_DATA]       = "DATA",
+        [RLIMIT_FSIZE]      = "FSIZE",
+        [RLIMIT_LOCKS]      = "LOCKS",
+        [RLIMIT_MEMLOCK]    = "MEMLOCK",
+        [RLIMIT_MSGQUEUE]   = "MSGQUEUE",
+        [RLIMIT_NICE]       = "NICE",
+        [RLIMIT_NOFILE]     = "NOFILE",
+        [RLIMIT_NPROC]      = "NPROC",
+        [RLIMIT_RSS]        = "RSS",
+        [RLIMIT_RTPRIO]     = "RTPRIO",
+        [RLIMIT_RTTIME]     = "RTTIME",
+        [RLIMIT_SIGPENDING] = "SIGPENDING",
+        [RLIMIT_STACK]      = "STACK",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(rlimit, int);
+
+int rlimit_from_string_harder(const char *s) {
+        const char *suffix;
+
+        /* The official prefix */
+        suffix = startswith(s, "RLIMIT_");
+        if (suffix)
+                return rlimit_from_string(suffix);
+
+        /* Our own unit file setting prefix */
+        suffix = startswith(s, "Limit");
+        if (suffix)
+                return rlimit_from_string(suffix);
+
+        return rlimit_from_string(s);
+}
+
+void rlimit_free_all(struct rlimit **rl) {
+        int i;
+
+        if (!rl)
+                return;
+
+        for (i = 0; i < _RLIMIT_MAX; i++)
+                rl[i] = mfree(rl[i]);
+}
+
+int rlimit_nofile_bump(int limit) {
+        int r;
+
+        /* Bumps the (soft) RLIMIT_NOFILE resource limit as close as possible to the specified limit. If a negative
+         * limit is specified, bumps it to the maximum the kernel and the hard resource limit allows. This call should
+         * be used by all our programs that might need a lot of fds, and that know how to deal with high fd numbers
+         * (i.e. do not use select() — which chokes on fds >= 1024) */
+
+        if (limit < 0)
+                limit = read_nr_open();
+
+        if (limit < 3)
+                limit = 3;
+
+        r = setrlimit_closest(RLIMIT_NOFILE, &RLIMIT_MAKE_CONST(limit));
+        if (r < 0)
+                return log_debug_errno(r, "Failed to set RLIMIT_NOFILE: %m");
+
+        return 0;
+}
+
+int rlimit_nofile_safe(void) {
+        struct rlimit rl;
+
+        /* Resets RLIMIT_NOFILE's soft limit FD_SETSIZE (i.e. 1024), for compatibility with software still using
+         * select() */
+
+        if (getrlimit(RLIMIT_NOFILE, &rl) < 0)
+                return log_debug_errno(errno, "Failed to query RLIMIT_NOFILE: %m");
+
+        if (rl.rlim_cur <= FD_SETSIZE)
+                return 0;
+
+        rl.rlim_cur = FD_SETSIZE;
+        if (setrlimit(RLIMIT_NOFILE, &rl) < 0)
+                return log_debug_errno(errno, "Failed to lower RLIMIT_NOFILE's soft limit to " RLIM_FMT ": %m", rl.rlim_cur);
+
+        return 1;
+}
diff --git a/src/basic/rlimit-util.h b/src/basic/rlimit-util.h
new file mode 100644
index 0000000..d4fca2b
--- /dev/null
+++ b/src/basic/rlimit-util.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/resource.h>
+
+#include "macro.h"
+
+const char *rlimit_to_string(int i) _const_;
+int rlimit_from_string(const char *s) _pure_;
+int rlimit_from_string_harder(const char *s) _pure_;
+
+int setrlimit_closest(int resource, const struct rlimit *rlim);
+int setrlimit_closest_all(const struct rlimit * const *rlim, int *which_failed);
+
+int rlimit_parse_one(int resource, const char *val, rlim_t *ret);
+int rlimit_parse(int resource, const char *val, struct rlimit *ret);
+
+int rlimit_format(const struct rlimit *rl, char **ret);
+
+void rlimit_free_all(struct rlimit **rl);
+
+#define RLIMIT_MAKE_CONST(lim) ((struct rlimit) { lim, lim })
+
+int rlimit_nofile_bump(int limit);
+int rlimit_nofile_safe(void);
diff --git a/src/basic/rm-rf.c b/src/basic/rm-rf.c
new file mode 100644
index 0000000..0c957c9
--- /dev/null
+++ b/src/basic/rm-rf.c
@@ -0,0 +1,220 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "btrfs-util.h"
+#include "cgroup-util.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "log.h"
+#include "macro.h"
+#include "mountpoint-util.h"
+#include "path-util.h"
+#include "rm-rf.h"
+#include "stat-util.h"
+#include "string-util.h"
+
+static bool is_physical_fs(const struct statfs *sfs) {
+        return !is_temporary_fs(sfs) && !is_cgroup_fs(sfs);
+}
+
+int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev) {
+        _cleanup_closedir_ DIR *d = NULL;
+        struct dirent *de;
+        int ret = 0, r;
+        struct statfs sfs;
+
+        assert(fd >= 0);
+
+        /* This returns the first error we run into, but nevertheless
+         * tries to go on. This closes the passed fd. */
+
+        if (!(flags & REMOVE_PHYSICAL)) {
+
+                r = fstatfs(fd, &sfs);
+                if (r < 0) {
+                        safe_close(fd);
+                        return -errno;
+                }
+
+                if (is_physical_fs(&sfs)) {
+                        /* We refuse to clean physical file systems with this call,
+                         * unless explicitly requested. This is extra paranoia just
+                         * to be sure we never ever remove non-state data. */
+                        _cleanup_free_ char *path = NULL;
+
+                        (void) fd_get_path(fd, &path);
+                        log_error("Attempted to remove disk file system under \"%s\", and we can't allow that.",
+                                  strna(path));
+
+                        safe_close(fd);
+                        return -EPERM;
+                }
+        }
+
+        d = fdopendir(fd);
+        if (!d) {
+                safe_close(fd);
+                return errno == ENOENT ? 0 : -errno;
+        }
+
+        FOREACH_DIRENT_ALL(de, d, return -errno) {
+                bool is_dir;
+                struct stat st;
+
+                if (dot_or_dot_dot(de->d_name))
+                        continue;
+
+                if (de->d_type == DT_UNKNOWN ||
+                    (de->d_type == DT_DIR && (root_dev || (flags & REMOVE_SUBVOLUME)))) {
+                        if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
+                                if (ret == 0 && errno != ENOENT)
+                                        ret = -errno;
+                                continue;
+                        }
+
+                        is_dir = S_ISDIR(st.st_mode);
+                } else
+                        is_dir = de->d_type == DT_DIR;
+
+                if (is_dir) {
+                        int subdir_fd;
+
+                        /* if root_dev is set, remove subdirectories only if device is same */
+                        if (root_dev && st.st_dev != root_dev->st_dev)
+                                continue;
+
+                        subdir_fd = openat(fd, de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+                        if (subdir_fd < 0) {
+                                if (ret == 0 && errno != ENOENT)
+                                        ret = -errno;
+                                continue;
+                        }
+
+                        /* Stop at mount points */
+                        r = fd_is_mount_point(fd, de->d_name, 0);
+                        if (r < 0) {
+                                if (ret == 0 && r != -ENOENT)
+                                        ret = r;
+
+                                safe_close(subdir_fd);
+                                continue;
+                        }
+                        if (r) {
+                                safe_close(subdir_fd);
+                                continue;
+                        }
+
+                        if ((flags & REMOVE_SUBVOLUME) && st.st_ino == 256) {
+
+                                /* This could be a subvolume, try to remove it */
+
+                                r = btrfs_subvol_remove_fd(fd, de->d_name, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
+                                if (r < 0) {
+                                        if (!IN_SET(r, -ENOTTY, -EINVAL)) {
+                                                if (ret == 0)
+                                                        ret = r;
+
+                                                safe_close(subdir_fd);
+                                                continue;
+                                        }
+
+                                        /* ENOTTY, then it wasn't a
+                                         * btrfs subvolume, continue
+                                         * below. */
+                                } else {
+                                        /* It was a subvolume, continue. */
+                                        safe_close(subdir_fd);
+                                        continue;
+                                }
+                        }
+
+                        /* We pass REMOVE_PHYSICAL here, to avoid
+                         * doing the fstatfs() to check the file
+                         * system type again for each directory */
+                        r = rm_rf_children(subdir_fd, flags | REMOVE_PHYSICAL, root_dev);
+                        if (r < 0 && ret == 0)
+                                ret = r;
+
+                        if (unlinkat(fd, de->d_name, AT_REMOVEDIR) < 0) {
+                                if (ret == 0 && errno != ENOENT)
+                                        ret = -errno;
+                        }
+
+                } else if (!(flags & REMOVE_ONLY_DIRECTORIES)) {
+
+                        if (unlinkat(fd, de->d_name, 0) < 0) {
+                                if (ret == 0 && errno != ENOENT)
+                                        ret = -errno;
+                        }
+                }
+        }
+        return ret;
+}
+
+int rm_rf(const char *path, RemoveFlags flags) {
+        int fd, r;
+        struct statfs s;
+
+        assert(path);
+
+        /* We refuse to clean the root file system with this
+         * call. This is extra paranoia to never cause a really
+         * seriously broken system. */
+        if (path_equal_or_files_same(path, "/", AT_SYMLINK_NOFOLLOW))
+                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
+                                       "Attempted to remove entire root file system (\"%s\"), and we can't allow that.",
+                                       path);
+
+        if (FLAGS_SET(flags, REMOVE_SUBVOLUME | REMOVE_ROOT | REMOVE_PHYSICAL)) {
+                /* Try to remove as subvolume first */
+                r = btrfs_subvol_remove(path, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
+                if (r >= 0)
+                        return r;
+
+                if (!IN_SET(r, -ENOTTY, -EINVAL, -ENOTDIR))
+                        return r;
+
+                /* Not btrfs or not a subvolume */
+        }
+
+        fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+        if (fd < 0) {
+                if (!IN_SET(errno, ENOTDIR, ELOOP))
+                        return -errno;
+
+                if (!(flags & REMOVE_PHYSICAL)) {
+                        if (statfs(path, &s) < 0)
+                                return -errno;
+
+                        if (is_physical_fs(&s))
+                                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
+                                                       "Attempted to remove files from a disk file system under \"%s\", refusing.",
+                                                       path);
+                }
+
+                if ((flags & REMOVE_ROOT) && !(flags & REMOVE_ONLY_DIRECTORIES))
+                        if (unlink(path) < 0 && errno != ENOENT)
+                                return -errno;
+
+                return 0;
+        }
+
+        r = rm_rf_children(fd, flags, NULL);
+
+        if (flags & REMOVE_ROOT) {
+                if (rmdir(path) < 0) {
+                        if (r == 0 && errno != ENOENT)
+                                r = -errno;
+                }
+        }
+
+        return r;
+}
diff --git a/src/basic/rm-rf.h b/src/basic/rm-rf.h
new file mode 100644
index 0000000..3ee2b97
--- /dev/null
+++ b/src/basic/rm-rf.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <sys/stat.h>
+
+#include "util.h"
+
+typedef enum RemoveFlags {
+        REMOVE_ONLY_DIRECTORIES = 1 << 0,
+        REMOVE_ROOT             = 1 << 1,
+        REMOVE_PHYSICAL         = 1 << 2, /* if not set, only removes files on tmpfs, never physical file systems */
+        REMOVE_SUBVOLUME        = 1 << 3,
+} RemoveFlags;
+
+int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev);
+int rm_rf(const char *path, RemoveFlags flags);
+
+/* Useful for usage with _cleanup_(), destroys a directory and frees the pointer */
+static inline void rm_rf_physical_and_free(char *p) {
+        PROTECT_ERRNO;
+        (void) rm_rf(p, REMOVE_ROOT|REMOVE_PHYSICAL);
+        free(p);
+}
+DEFINE_TRIVIAL_CLEANUP_FUNC(char*, rm_rf_physical_and_free);
+
+/* Similar as above, but also has magic btrfs subvolume powers */
+static inline void rm_rf_subvolume_and_free(char *p) {
+        PROTECT_ERRNO;
+        (void) rm_rf(p, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
+        free(p);
+}
+DEFINE_TRIVIAL_CLEANUP_FUNC(char*, rm_rf_subvolume_and_free);
diff --git a/src/basic/selinux-util.c b/src/basic/selinux-util.c
new file mode 100644
index 0000000..dc06f3d
--- /dev/null
+++ b/src/basic/selinux-util.c
@@ -0,0 +1,518 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <malloc.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/un.h>
+#include <syslog.h>
+
+#if HAVE_SELINUX
+#include <selinux/context.h>
+#include <selinux/label.h>
+#include <selinux/selinux.h>
+#endif
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "log.h"
+#include "macro.h"
+#include "path-util.h"
+#include "selinux-util.h"
+#include "stdio-util.h"
+#include "time-util.h"
+#include "util.h"
+
+#if HAVE_SELINUX
+DEFINE_TRIVIAL_CLEANUP_FUNC(char*, freecon);
+DEFINE_TRIVIAL_CLEANUP_FUNC(context_t, context_free);
+
+#define _cleanup_freecon_ _cleanup_(freeconp)
+#define _cleanup_context_free_ _cleanup_(context_freep)
+
+static int cached_use = -1;
+static struct selabel_handle *label_hnd = NULL;
+
+#define log_enforcing(...) log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG, __VA_ARGS__)
+#define log_enforcing_errno(r, ...) log_full_errno(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG, r, __VA_ARGS__)
+#endif
+
+bool mac_selinux_use(void) {
+#if HAVE_SELINUX
+        if (cached_use < 0)
+                cached_use = is_selinux_enabled() > 0;
+
+        return cached_use;
+#else
+        return false;
+#endif
+}
+
+void mac_selinux_retest(void) {
+#if HAVE_SELINUX
+        cached_use = -1;
+#endif
+}
+
+int mac_selinux_init(void) {
+        int r = 0;
+
+#if HAVE_SELINUX
+        usec_t before_timestamp, after_timestamp;
+        struct mallinfo before_mallinfo, after_mallinfo;
+
+        if (label_hnd)
+                return 0;
+
+        if (!mac_selinux_use())
+                return 0;
+
+        before_mallinfo = mallinfo();
+        before_timestamp = now(CLOCK_MONOTONIC);
+
+        label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0);
+        if (!label_hnd) {
+                log_enforcing_errno(errno, "Failed to initialize SELinux context: %m");
+                r = security_getenforce() == 1 ? -errno : 0;
+        } else  {
+                char timespan[FORMAT_TIMESPAN_MAX];
+                int l;
+
+                after_timestamp = now(CLOCK_MONOTONIC);
+                after_mallinfo = mallinfo();
+
+                l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0;
+
+                log_debug("Successfully loaded SELinux database in %s, size on heap is %iK.",
+                          format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp, 0),
+                          (l+1023)/1024);
+        }
+#endif
+
+        return r;
+}
+
+void mac_selinux_finish(void) {
+
+#if HAVE_SELINUX
+        if (!label_hnd)
+                return;
+
+        selabel_close(label_hnd);
+        label_hnd = NULL;
+#endif
+}
+
+int mac_selinux_fix(const char *path, LabelFixFlags flags) {
+
+#if HAVE_SELINUX
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        _cleanup_freecon_ char* fcon = NULL;
+        _cleanup_close_ int fd = -1;
+        struct stat st;
+        int r;
+
+        assert(path);
+
+        /* if mac_selinux_init() wasn't called before we are a NOOP */
+        if (!label_hnd)
+                return 0;
+
+        /* Open the file as O_PATH, to pin it while we determine and adjust the label */
+        fd = open(path, O_NOFOLLOW|O_CLOEXEC|O_PATH);
+        if (fd < 0) {
+                if ((flags & LABEL_IGNORE_ENOENT) && errno == ENOENT)
+                        return 0;
+
+                return -errno;
+        }
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (selabel_lookup_raw(label_hnd, &fcon, path, st.st_mode) < 0) {
+                r = -errno;
+
+                /* If there's no label to set, then exit without warning */
+                if (r == -ENOENT)
+                        return 0;
+
+                goto fail;
+        }
+
+        xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+        if (setfilecon_raw(procfs_path, fcon) < 0) {
+                _cleanup_freecon_ char *oldcon = NULL;
+
+                r = -errno;
+
+                /* If the FS doesn't support labels, then exit without warning */
+                if (r == -EOPNOTSUPP)
+                        return 0;
+
+                /* It the FS is read-only and we were told to ignore failures caused by that, suppress error */
+                if (r == -EROFS && (flags & LABEL_IGNORE_EROFS))
+                        return 0;
+
+                /* If the old label is identical to the new one, suppress any kind of error */
+                if (getfilecon_raw(procfs_path, &oldcon) >= 0 && streq(fcon, oldcon))
+                        return 0;
+
+                goto fail;
+        }
+
+        return 0;
+
+fail:
+        log_enforcing_errno(r, "Unable to fix SELinux security context of %s: %m", path);
+        if (security_getenforce() == 1)
+                return r;
+#endif
+
+        return 0;
+}
+
+int mac_selinux_apply(const char *path, const char *label) {
+
+#if HAVE_SELINUX
+        if (!mac_selinux_use())
+                return 0;
+
+        assert(path);
+        assert(label);
+
+        if (setfilecon(path, label) < 0) {
+                log_enforcing_errno(errno, "Failed to set SELinux security context %s on path %s: %m", label, path);
+                if (security_getenforce() > 0)
+                        return -errno;
+        }
+#endif
+        return 0;
+}
+
+int mac_selinux_get_create_label_from_exe(const char *exe, char **label) {
+        int r = -EOPNOTSUPP;
+
+#if HAVE_SELINUX
+        _cleanup_freecon_ char *mycon = NULL, *fcon = NULL;
+        security_class_t sclass;
+
+        assert(exe);
+        assert(label);
+
+        if (!mac_selinux_use())
+                return -EOPNOTSUPP;
+
+        r = getcon_raw(&mycon);
+        if (r < 0)
+                return -errno;
+
+        r = getfilecon_raw(exe, &fcon);
+        if (r < 0)
+                return -errno;
+
+        sclass = string_to_security_class("process");
+        r = security_compute_create_raw(mycon, fcon, sclass, label);
+        if (r < 0)
+                return -errno;
+#endif
+
+        return r;
+}
+
+int mac_selinux_get_our_label(char **label) {
+        int r = -EOPNOTSUPP;
+
+        assert(label);
+
+#if HAVE_SELINUX
+        if (!mac_selinux_use())
+                return -EOPNOTSUPP;
+
+        r = getcon_raw(label);
+        if (r < 0)
+                return -errno;
+#endif
+
+        return r;
+}
+
+int mac_selinux_get_child_mls_label(int socket_fd, const char *exe, const char *exec_label, char **label) {
+        int r = -EOPNOTSUPP;
+
+#if HAVE_SELINUX
+        _cleanup_freecon_ char *mycon = NULL, *peercon = NULL, *fcon = NULL;
+        _cleanup_context_free_ context_t pcon = NULL, bcon = NULL;
+        security_class_t sclass;
+        const char *range = NULL;
+
+        assert(socket_fd >= 0);
+        assert(exe);
+        assert(label);
+
+        if (!mac_selinux_use())
+                return -EOPNOTSUPP;
+
+        r = getcon_raw(&mycon);
+        if (r < 0)
+                return -errno;
+
+        r = getpeercon_raw(socket_fd, &peercon);
+        if (r < 0)
+                return -errno;
+
+        if (!exec_label) {
+                /* If there is no context set for next exec let's use context
+                   of target executable */
+                r = getfilecon_raw(exe, &fcon);
+                if (r < 0)
+                        return -errno;
+        }
+
+        bcon = context_new(mycon);
+        if (!bcon)
+                return -ENOMEM;
+
+        pcon = context_new(peercon);
+        if (!pcon)
+                return -ENOMEM;
+
+        range = context_range_get(pcon);
+        if (!range)
+                return -errno;
+
+        r = context_range_set(bcon, range);
+        if (r)
+                return -errno;
+
+        freecon(mycon);
+        mycon = strdup(context_str(bcon));
+        if (!mycon)
+                return -ENOMEM;
+
+        sclass = string_to_security_class("process");
+        r = security_compute_create_raw(mycon, fcon, sclass, label);
+        if (r < 0)
+                return -errno;
+#endif
+
+        return r;
+}
+
+char* mac_selinux_free(char *label) {
+
+#if HAVE_SELINUX
+        if (!label)
+                return NULL;
+
+        if (!mac_selinux_use())
+                return NULL;
+
+        freecon(label);
+#endif
+
+        return NULL;
+}
+
+#if HAVE_SELINUX
+static int selinux_create_file_prepare_abspath(const char *abspath, mode_t mode) {
+        _cleanup_freecon_ char *filecon = NULL;
+        int r;
+
+        assert(abspath);
+        assert(path_is_absolute(abspath));
+
+        r = selabel_lookup_raw(label_hnd, &filecon, abspath, mode);
+        if (r < 0) {
+                /* No context specified by the policy? Proceed without setting it. */
+                if (errno == ENOENT)
+                        return 0;
+
+                log_enforcing_errno(errno, "Failed to determine SELinux security context for %s: %m", abspath);
+        } else {
+                if (setfscreatecon_raw(filecon) >= 0)
+                        return 0; /* Success! */
+
+                log_enforcing_errno(errno, "Failed to set SELinux security context %s for %s: %m", filecon, abspath);
+        }
+
+        if (security_getenforce() > 0)
+                return -errno;
+
+        return 0;
+}
+#endif
+
+int mac_selinux_create_file_prepare_at(int dirfd, const char *path, mode_t mode) {
+        int r = 0;
+
+#if HAVE_SELINUX
+        _cleanup_free_ char *abspath = NULL;
+
+        assert(path);
+
+        if (!label_hnd)
+                return 0;
+
+        if (!path_is_absolute(path)) {
+                _cleanup_free_ char *p = NULL;
+
+                if (dirfd == AT_FDCWD)
+                        r = safe_getcwd(&p);
+                else
+                        r = fd_get_path(dirfd, &p);
+                if (r < 0)
+                        return r;
+
+                path = abspath = path_join(p, path);
+                if (!path)
+                        return -ENOMEM;
+        }
+
+        r = selinux_create_file_prepare_abspath(path, mode);
+#endif
+        return r;
+}
+
+int mac_selinux_create_file_prepare(const char *path, mode_t mode) {
+        int r = 0;
+
+#if HAVE_SELINUX
+        _cleanup_free_ char *abspath = NULL;
+
+        assert(path);
+
+        if (!label_hnd)
+                return 0;
+
+        r = path_make_absolute_cwd(path, &abspath);
+        if (r < 0)
+                return r;
+
+        r = selinux_create_file_prepare_abspath(abspath, mode);
+#endif
+        return r;
+}
+
+void mac_selinux_create_file_clear(void) {
+
+#if HAVE_SELINUX
+        PROTECT_ERRNO;
+
+        if (!mac_selinux_use())
+                return;
+
+        setfscreatecon_raw(NULL);
+#endif
+}
+
+int mac_selinux_create_socket_prepare(const char *label) {
+
+#if HAVE_SELINUX
+        if (!mac_selinux_use())
+                return 0;
+
+        assert(label);
+
+        if (setsockcreatecon(label) < 0) {
+                log_enforcing_errno(errno, "Failed to set SELinux security context %s for sockets: %m", label);
+
+                if (security_getenforce() == 1)
+                        return -errno;
+        }
+#endif
+
+        return 0;
+}
+
+void mac_selinux_create_socket_clear(void) {
+
+#if HAVE_SELINUX
+        PROTECT_ERRNO;
+
+        if (!mac_selinux_use())
+                return;
+
+        setsockcreatecon_raw(NULL);
+#endif
+}
+
+int mac_selinux_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) {
+
+        /* Binds a socket and label its file system object according to the SELinux policy */
+
+#if HAVE_SELINUX
+        _cleanup_freecon_ char *fcon = NULL;
+        const struct sockaddr_un *un;
+        bool context_changed = false;
+        char *path;
+        int r;
+
+        assert(fd >= 0);
+        assert(addr);
+        assert(addrlen >= sizeof(sa_family_t));
+
+        if (!label_hnd)
+                goto skipped;
+
+        /* Filter out non-local sockets */
+        if (addr->sa_family != AF_UNIX)
+                goto skipped;
+
+        /* Filter out anonymous sockets */
+        if (addrlen < offsetof(struct sockaddr_un, sun_path) + 1)
+                goto skipped;
+
+        /* Filter out abstract namespace sockets */
+        un = (const struct sockaddr_un*) addr;
+        if (un->sun_path[0] == 0)
+                goto skipped;
+
+        path = strndupa(un->sun_path, addrlen - offsetof(struct sockaddr_un, sun_path));
+
+        if (path_is_absolute(path))
+                r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFSOCK);
+        else {
+                _cleanup_free_ char *newpath = NULL;
+
+                r = path_make_absolute_cwd(path, &newpath);
+                if (r < 0)
+                        return r;
+
+                r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFSOCK);
+        }
+
+        if (r < 0) {
+                /* No context specified by the policy? Proceed without setting it */
+                if (errno == ENOENT)
+                        goto skipped;
+
+                log_enforcing_errno(errno, "Failed to determine SELinux security context for %s: %m", path);
+                if (security_getenforce() > 0)
+                        return -errno;
+
+        } else {
+                if (setfscreatecon_raw(fcon) < 0) {
+                        log_enforcing_errno(errno, "Failed to set SELinux security context %s for %s: %m", fcon, path);
+                        if (security_getenforce() > 0)
+                                return -errno;
+                } else
+                        context_changed = true;
+        }
+
+        r = bind(fd, addr, addrlen) < 0 ? -errno : 0;
+
+        if (context_changed)
+                setfscreatecon_raw(NULL);
+
+        return r;
+
+skipped:
+#endif
+        if (bind(fd, addr, addrlen) < 0)
+                return -errno;
+
+        return 0;
+}
diff --git a/src/basic/selinux-util.h b/src/basic/selinux-util.h
new file mode 100644
index 0000000..bd5207c
--- /dev/null
+++ b/src/basic/selinux-util.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#include "macro.h"
+#include "label.h"
+
+bool mac_selinux_use(void);
+void mac_selinux_retest(void);
+
+int mac_selinux_init(void);
+void mac_selinux_finish(void);
+
+int mac_selinux_fix(const char *path, LabelFixFlags flags);
+int mac_selinux_apply(const char *path, const char *label);
+
+int mac_selinux_get_create_label_from_exe(const char *exe, char **label);
+int mac_selinux_get_our_label(char **label);
+int mac_selinux_get_child_mls_label(int socket_fd, const char *exe, const char *exec_label, char **label);
+char* mac_selinux_free(char *label);
+
+int mac_selinux_create_file_prepare(const char *path, mode_t mode);
+int mac_selinux_create_file_prepare_at(int dirfd, const char *path, mode_t mode);
+void mac_selinux_create_file_clear(void);
+
+int mac_selinux_create_socket_prepare(const char *label);
+void mac_selinux_create_socket_clear(void);
+
+int mac_selinux_bind(int fd, const struct sockaddr *addr, socklen_t addrlen);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(char*, mac_selinux_free);
diff --git a/src/basic/set.h b/src/basic/set.h
new file mode 100644
index 0000000..2a80632
--- /dev/null
+++ b/src/basic/set.h
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "extract-word.h"
+#include "hashmap.h"
+#include "macro.h"
+
+Set *internal_set_new(const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS);
+#define set_new(ops) internal_set_new(ops HASHMAP_DEBUG_SRC_ARGS)
+
+static inline Set *set_free(Set *s) {
+        return (Set*) internal_hashmap_free(HASHMAP_BASE(s), NULL, NULL);
+}
+
+static inline Set *set_free_free(Set *s) {
+        return (Set*) internal_hashmap_free(HASHMAP_BASE(s), free, NULL);
+}
+
+/* no set_free_free_free */
+
+static inline Set *set_copy(Set *s) {
+        return (Set*) internal_hashmap_copy(HASHMAP_BASE(s));
+}
+
+int internal_set_ensure_allocated(Set **s, const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS);
+#define set_ensure_allocated(h, ops) internal_set_ensure_allocated(h, ops HASHMAP_DEBUG_SRC_ARGS)
+
+int set_put(Set *s, const void *key);
+/* no set_update */
+/* no set_replace */
+static inline void *set_get(Set *s, void *key) {
+        return internal_hashmap_get(HASHMAP_BASE(s), key);
+}
+/* no set_get2 */
+
+static inline bool set_contains(Set *s, const void *key) {
+        return internal_hashmap_contains(HASHMAP_BASE(s), key);
+}
+
+static inline void *set_remove(Set *s, const void *key) {
+        return internal_hashmap_remove(HASHMAP_BASE(s), key);
+}
+
+/* no set_remove2 */
+/* no set_remove_value */
+int set_remove_and_put(Set *s, const void *old_key, const void *new_key);
+/* no set_remove_and_replace */
+int set_merge(Set *s, Set *other);
+
+static inline int set_reserve(Set *h, unsigned entries_add) {
+        return internal_hashmap_reserve(HASHMAP_BASE(h), entries_add);
+}
+
+static inline int set_move(Set *s, Set *other) {
+        return internal_hashmap_move(HASHMAP_BASE(s), HASHMAP_BASE(other));
+}
+
+static inline int set_move_one(Set *s, Set *other, const void *key) {
+        return internal_hashmap_move_one(HASHMAP_BASE(s), HASHMAP_BASE(other), key);
+}
+
+static inline unsigned set_size(Set *s) {
+        return internal_hashmap_size(HASHMAP_BASE(s));
+}
+
+static inline bool set_isempty(Set *s) {
+        return set_size(s) == 0;
+}
+
+static inline unsigned set_buckets(Set *s) {
+        return internal_hashmap_buckets(HASHMAP_BASE(s));
+}
+
+bool set_iterate(Set *s, Iterator *i, void **value);
+
+static inline void set_clear(Set *s) {
+        internal_hashmap_clear(HASHMAP_BASE(s), NULL, NULL);
+}
+
+static inline void set_clear_free(Set *s) {
+        internal_hashmap_clear(HASHMAP_BASE(s), free, NULL);
+}
+
+/* no set_clear_free_free */
+
+static inline void *set_steal_first(Set *s) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(s), true, NULL);
+}
+
+#define set_clear_with_destructor(_s, _f)               \
+        ({                                              \
+                void *_item;                            \
+                while ((_item = set_steal_first(_s)))   \
+                        _f(_item);                      \
+        })
+#define set_free_with_destructor(_s, _f)                \
+        ({                                              \
+                set_clear_with_destructor(_s, _f);      \
+                set_free(_s);                           \
+        })
+
+/* no set_steal_first_key */
+/* no set_first_key */
+
+static inline void *set_first(Set *s) {
+        return internal_hashmap_first_key_and_value(HASHMAP_BASE(s), false, NULL);
+}
+
+/* no set_next */
+
+static inline char **set_get_strv(Set *s) {
+        return internal_hashmap_get_strv(HASHMAP_BASE(s));
+}
+
+int set_consume(Set *s, void *value);
+int set_put_strdup(Set *s, const char *p);
+int set_put_strdupv(Set *s, char **l);
+int set_put_strsplit(Set *s, const char *v, const char *separators, ExtractFlags flags);
+
+#define SET_FOREACH(e, s, i) \
+        for ((i) = ITERATOR_FIRST; set_iterate((s), &(i), (void**)&(e)); )
+
+#define SET_FOREACH_MOVE(e, d, s)                                       \
+        for (; ({ e = set_first(s); assert_se(!e || set_move_one(d, s, e) >= 0); e; }); )
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Set*, set_free);
+DEFINE_TRIVIAL_CLEANUP_FUNC(Set*, set_free_free);
+
+#define _cleanup_set_free_ _cleanup_(set_freep)
+#define _cleanup_set_free_free_ _cleanup_(set_free_freep)
diff --git a/src/basic/sigbus.c b/src/basic/sigbus.c
new file mode 100644
index 0000000..d5254ea
--- /dev/null
+++ b/src/basic/sigbus.c
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <stddef.h>
+#include <sys/mman.h>
+
+#include "macro.h"
+#include "sigbus.h"
+#include "util.h"
+
+#define SIGBUS_QUEUE_MAX 64
+
+static struct sigaction old_sigaction;
+static unsigned n_installed = 0;
+
+/* We maintain a fixed size list of page addresses that triggered a
+   SIGBUS. We access with list with atomic operations, so that we
+   don't have to deal with locks between signal handler and main
+   programs in possibly multiple threads. */
+
+static void* volatile sigbus_queue[SIGBUS_QUEUE_MAX];
+static volatile sig_atomic_t n_sigbus_queue = 0;
+
+static void sigbus_push(void *addr) {
+        unsigned u;
+
+        assert(addr);
+
+        /* Find a free place, increase the number of entries and leave, if we can */
+        for (u = 0; u < SIGBUS_QUEUE_MAX; u++)
+                if (__sync_bool_compare_and_swap(&sigbus_queue[u], NULL, addr)) {
+                        __sync_fetch_and_add(&n_sigbus_queue, 1);
+                        return;
+                }
+
+        /* If we can't, make sure the queue size is out of bounds, to
+         * mark it as overflow */
+        for (;;) {
+                unsigned c;
+
+                __sync_synchronize();
+                c = n_sigbus_queue;
+
+                if (c > SIGBUS_QUEUE_MAX) /* already overflow */
+                        return;
+
+                if (__sync_bool_compare_and_swap(&n_sigbus_queue, c, c + SIGBUS_QUEUE_MAX))
+                        return;
+        }
+}
+
+int sigbus_pop(void **ret) {
+        assert(ret);
+
+        for (;;) {
+                unsigned u, c;
+
+                __sync_synchronize();
+                c = n_sigbus_queue;
+
+                if (_likely_(c == 0))
+                        return 0;
+
+                if (_unlikely_(c >= SIGBUS_QUEUE_MAX))
+                        return -EOVERFLOW;
+
+                for (u = 0; u < SIGBUS_QUEUE_MAX; u++) {
+                        void *addr;
+
+                        addr = sigbus_queue[u];
+                        if (!addr)
+                                continue;
+
+                        if (__sync_bool_compare_and_swap(&sigbus_queue[u], addr, NULL)) {
+                                __sync_fetch_and_sub(&n_sigbus_queue, 1);
+                                *ret = addr;
+                                return 1;
+                        }
+                }
+        }
+}
+
+static void sigbus_handler(int sn, siginfo_t *si, void *data) {
+        unsigned long ul;
+        void *aligned;
+
+        assert(sn == SIGBUS);
+        assert(si);
+
+        if (si->si_code != BUS_ADRERR || !si->si_addr) {
+                assert_se(sigaction(SIGBUS, &old_sigaction, NULL) == 0);
+                raise(SIGBUS);
+                return;
+        }
+
+        ul = (unsigned long) si->si_addr;
+        ul = ul / page_size();
+        ul = ul * page_size();
+        aligned = (void*) ul;
+
+        /* Let's remember which address failed */
+        sigbus_push(aligned);
+
+        /* Replace mapping with an anonymous page, so that the
+         * execution can continue, however with a zeroed out page */
+        assert_se(mmap(aligned, page_size(), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0) == aligned);
+}
+
+void sigbus_install(void) {
+        struct sigaction sa = {
+                .sa_sigaction = sigbus_handler,
+                .sa_flags = SA_SIGINFO,
+        };
+
+        /* make sure that sysconf() is not called from a signal handler because
+        * it is not guaranteed to be async-signal-safe since POSIX.1-2008 */
+        (void) page_size();
+
+        n_installed++;
+
+        if (n_installed == 1)
+                assert_se(sigaction(SIGBUS, &sa, &old_sigaction) == 0);
+
+        return;
+}
+
+void sigbus_reset(void) {
+
+        if (n_installed <= 0)
+                return;
+
+        n_installed--;
+
+        if (n_installed == 0)
+                assert_se(sigaction(SIGBUS, &old_sigaction, NULL) == 0);
+
+        return;
+}
diff --git a/src/basic/sigbus.h b/src/basic/sigbus.h
new file mode 100644
index 0000000..459e19f
--- /dev/null
+++ b/src/basic/sigbus.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+void sigbus_install(void);
+void sigbus_reset(void);
+
+int sigbus_pop(void **ret);
diff --git a/src/basic/signal-util.c b/src/basic/signal-util.c
new file mode 100644
index 0000000..fb8a63f
--- /dev/null
+++ b/src/basic/signal-util.c
@@ -0,0 +1,290 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "macro.h"
+#include "parse-util.h"
+#include "signal-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "string-util.h"
+
+int reset_all_signal_handlers(void) {
+        static const struct sigaction sa = {
+                .sa_handler = SIG_DFL,
+                .sa_flags = SA_RESTART,
+        };
+        int sig, r = 0;
+
+        for (sig = 1; sig < _NSIG; sig++) {
+
+                /* These two cannot be caught... */
+                if (IN_SET(sig, SIGKILL, SIGSTOP))
+                        continue;
+
+                /* On Linux the first two RT signals are reserved by
+                 * glibc, and sigaction() will return EINVAL for them. */
+                if ((sigaction(sig, &sa, NULL) < 0))
+                        if (errno != EINVAL && r >= 0)
+                                r = -errno;
+        }
+
+        return r;
+}
+
+int reset_signal_mask(void) {
+        sigset_t ss;
+
+        if (sigemptyset(&ss) < 0)
+                return -errno;
+
+        if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int sigaction_many_ap(const struct sigaction *sa, int sig, va_list ap) {
+        int r = 0;
+
+        /* negative signal ends the list. 0 signal is skipped. */
+
+        if (sig < 0)
+                return 0;
+
+        if (sig > 0) {
+                if (sigaction(sig, sa, NULL) < 0)
+                        r = -errno;
+        }
+
+        while ((sig = va_arg(ap, int)) >= 0) {
+
+                if (sig == 0)
+                        continue;
+
+                if (sigaction(sig, sa, NULL) < 0) {
+                        if (r >= 0)
+                                r = -errno;
+                }
+        }
+
+        return r;
+}
+
+int sigaction_many(const struct sigaction *sa, ...) {
+        va_list ap;
+        int r;
+
+        va_start(ap, sa);
+        r = sigaction_many_ap(sa, 0, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int ignore_signals(int sig, ...) {
+
+        static const struct sigaction sa = {
+                .sa_handler = SIG_IGN,
+                .sa_flags = SA_RESTART,
+        };
+
+        va_list ap;
+        int r;
+
+        va_start(ap, sig);
+        r = sigaction_many_ap(&sa, sig, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int default_signals(int sig, ...) {
+
+        static const struct sigaction sa = {
+                .sa_handler = SIG_DFL,
+                .sa_flags = SA_RESTART,
+        };
+
+        va_list ap;
+        int r;
+
+        va_start(ap, sig);
+        r = sigaction_many_ap(&sa, sig, ap);
+        va_end(ap);
+
+        return r;
+}
+
+static int sigset_add_many_ap(sigset_t *ss, va_list ap) {
+        int sig, r = 0;
+
+        assert(ss);
+
+        while ((sig = va_arg(ap, int)) >= 0) {
+
+                if (sig == 0)
+                        continue;
+
+                if (sigaddset(ss, sig) < 0) {
+                        if (r >= 0)
+                                r = -errno;
+                }
+        }
+
+        return r;
+}
+
+int sigset_add_many(sigset_t *ss, ...) {
+        va_list ap;
+        int r;
+
+        va_start(ap, ss);
+        r = sigset_add_many_ap(ss, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int sigprocmask_many(int how, sigset_t *old, ...) {
+        va_list ap;
+        sigset_t ss;
+        int r;
+
+        if (sigemptyset(&ss) < 0)
+                return -errno;
+
+        va_start(ap, old);
+        r = sigset_add_many_ap(&ss, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return r;
+
+        if (sigprocmask(how, &ss, old) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static const char *const __signal_table[] = {
+        [SIGHUP] = "HUP",
+        [SIGINT] = "INT",
+        [SIGQUIT] = "QUIT",
+        [SIGILL] = "ILL",
+        [SIGTRAP] = "TRAP",
+        [SIGABRT] = "ABRT",
+        [SIGBUS] = "BUS",
+        [SIGFPE] = "FPE",
+        [SIGKILL] = "KILL",
+        [SIGUSR1] = "USR1",
+        [SIGSEGV] = "SEGV",
+        [SIGUSR2] = "USR2",
+        [SIGPIPE] = "PIPE",
+        [SIGALRM] = "ALRM",
+        [SIGTERM] = "TERM",
+#ifdef SIGSTKFLT
+        [SIGSTKFLT] = "STKFLT",  /* Linux on SPARC doesn't know SIGSTKFLT */
+#endif
+        [SIGCHLD] = "CHLD",
+        [SIGCONT] = "CONT",
+        [SIGSTOP] = "STOP",
+        [SIGTSTP] = "TSTP",
+        [SIGTTIN] = "TTIN",
+        [SIGTTOU] = "TTOU",
+        [SIGURG] = "URG",
+        [SIGXCPU] = "XCPU",
+        [SIGXFSZ] = "XFSZ",
+        [SIGVTALRM] = "VTALRM",
+        [SIGPROF] = "PROF",
+        [SIGWINCH] = "WINCH",
+        [SIGIO] = "IO",
+        [SIGPWR] = "PWR",
+        [SIGSYS] = "SYS"
+};
+
+DEFINE_PRIVATE_STRING_TABLE_LOOKUP(__signal, int);
+
+const char *signal_to_string(int signo) {
+        static thread_local char buf[STRLEN("RTMIN+") + DECIMAL_STR_MAX(int) + 1];
+        const char *name;
+
+        name = __signal_to_string(signo);
+        if (name)
+                return name;
+
+        if (signo >= SIGRTMIN && signo <= SIGRTMAX)
+                xsprintf(buf, "RTMIN+%d", signo - SIGRTMIN);
+        else
+                xsprintf(buf, "%d", signo);
+
+        return buf;
+}
+
+int signal_from_string(const char *s) {
+        const char *p;
+        int signo, r;
+
+        /* Check that the input is a signal number. */
+        if (safe_atoi(s, &signo) >= 0) {
+                if (SIGNAL_VALID(signo))
+                        return signo;
+                else
+                        return -ERANGE;
+        }
+
+        /* Drop "SIG" prefix. */
+        if (startswith(s, "SIG"))
+                s += 3;
+
+        /* Check that the input is a signal name. */
+        signo = __signal_from_string(s);
+        if (signo > 0)
+                return signo;
+
+        /* Check that the input is RTMIN or
+         * RTMIN+n (0 <= n <= SIGRTMAX-SIGRTMIN). */
+        p = startswith(s, "RTMIN");
+        if (p) {
+                if (*p == '\0')
+                        return SIGRTMIN;
+                if (*p != '+')
+                        return -EINVAL;
+
+                r = safe_atoi(p, &signo);
+                if (r < 0)
+                        return r;
+
+                if (signo < 0 || signo > SIGRTMAX - SIGRTMIN)
+                        return -ERANGE;
+
+                return signo + SIGRTMIN;
+        }
+
+        /* Check that the input is RTMAX or
+         * RTMAX-n (0 <= n <= SIGRTMAX-SIGRTMIN). */
+        p = startswith(s, "RTMAX");
+        if (p) {
+                if (*p == '\0')
+                        return SIGRTMAX;
+                if (*p != '-')
+                        return -EINVAL;
+
+                r = safe_atoi(p, &signo);
+                if (r < 0)
+                        return r;
+
+                if (signo > 0 || signo < SIGRTMIN - SIGRTMAX)
+                        return -ERANGE;
+
+                return signo + SIGRTMAX;
+        }
+
+        return -EINVAL;
+}
+
+void nop_signal_handler(int sig) {
+        /* nothing here */
+}
diff --git a/src/basic/signal-util.h b/src/basic/signal-util.h
new file mode 100644
index 0000000..92f2804
--- /dev/null
+++ b/src/basic/signal-util.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <signal.h>
+
+#include "macro.h"
+
+int reset_all_signal_handlers(void);
+int reset_signal_mask(void);
+
+int ignore_signals(int sig, ...);
+int default_signals(int sig, ...);
+int sigaction_many(const struct sigaction *sa, ...);
+
+int sigset_add_many(sigset_t *ss, ...);
+int sigprocmask_many(int how, sigset_t *old, ...);
+
+const char *signal_to_string(int i) _const_;
+int signal_from_string(const char *s) _pure_;
+
+void nop_signal_handler(int sig);
+
+static inline void block_signals_reset(sigset_t *ss) {
+        assert_se(sigprocmask(SIG_SETMASK, ss, NULL) >= 0);
+}
+
+#define BLOCK_SIGNALS(...)                                                         \
+        _cleanup_(block_signals_reset) _unused_ sigset_t _saved_sigset = ({        \
+                sigset_t _t;                                                       \
+                assert_se(sigprocmask_many(SIG_BLOCK, &_t, __VA_ARGS__, -1) >= 0); \
+                _t;                                                                \
+        })
+
+static inline bool SIGNAL_VALID(int signo) {
+        return signo > 0 && signo < _NSIG;
+}
+
+static inline const char* signal_to_string_with_check(int n) {
+        if (!SIGNAL_VALID(n))
+                return NULL;
+
+        return signal_to_string(n);
+}
diff --git a/src/basic/siphash24.c b/src/basic/siphash24.c
new file mode 100644
index 0000000..6118081
--- /dev/null
+++ b/src/basic/siphash24.c
@@ -0,0 +1,200 @@
+/*
+   SipHash reference C implementation
+
+   Written in 2012 by
+   Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
+   Daniel J. Bernstein <djb@cr.yp.to>
+
+   To the extent possible under law, the author(s) have dedicated all copyright
+   and related and neighboring rights to this software to the public domain
+   worldwide. This software is distributed without any warranty.
+
+   You should have received a copy of the CC0 Public Domain Dedication along with
+   this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
+
+   (Minimal changes made by Lennart Poettering, to make clean for inclusion in systemd)
+   (Refactored by Tom Gundersen to split up in several functions and follow systemd
+    coding style)
+*/
+
+#include <stdio.h>
+
+#include "macro.h"
+#include "siphash24.h"
+#include "unaligned.h"
+
+static uint64_t rotate_left(uint64_t x, uint8_t b) {
+        assert(b < 64);
+
+        return (x << b) | (x >> (64 - b));
+}
+
+static void sipround(struct siphash *state) {
+        assert(state);
+
+        state->v0 += state->v1;
+        state->v1 = rotate_left(state->v1, 13);
+        state->v1 ^= state->v0;
+        state->v0 = rotate_left(state->v0, 32);
+        state->v2 += state->v3;
+        state->v3 = rotate_left(state->v3, 16);
+        state->v3 ^= state->v2;
+        state->v0 += state->v3;
+        state->v3 = rotate_left(state->v3, 21);
+        state->v3 ^= state->v0;
+        state->v2 += state->v1;
+        state->v1 = rotate_left(state->v1, 17);
+        state->v1 ^= state->v2;
+        state->v2 = rotate_left(state->v2, 32);
+}
+
+void siphash24_init(struct siphash *state, const uint8_t k[static 16]) {
+        uint64_t k0, k1;
+
+        assert(state);
+        assert(k);
+
+        k0 = unaligned_read_le64(k);
+        k1 = unaligned_read_le64(k + 8);
+
+        *state = (struct siphash) {
+                /* "somepseudorandomlygeneratedbytes" */
+                .v0 = 0x736f6d6570736575ULL ^ k0,
+                .v1 = 0x646f72616e646f6dULL ^ k1,
+                .v2 = 0x6c7967656e657261ULL ^ k0,
+                .v3 = 0x7465646279746573ULL ^ k1,
+                .padding = 0,
+                .inlen = 0,
+        };
+}
+
+void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) {
+
+        const uint8_t *in = _in;
+        const uint8_t *end = in + inlen;
+        size_t left = state->inlen & 7;
+        uint64_t m;
+
+        assert(in);
+        assert(state);
+
+        /* Update total length */
+        state->inlen += inlen;
+
+        /* If padding exists, fill it out */
+        if (left > 0) {
+                for ( ; in < end && left < 8; in ++, left ++)
+                        state->padding |= ((uint64_t) *in) << (left * 8);
+
+                if (in == end && left < 8)
+                        /* We did not have enough input to fill out the padding completely */
+                        return;
+
+#if ENABLE_DEBUG_SIPHASH
+                printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+                printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+                printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+                printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
+                printf("(%3zu) compress padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t)state->padding);
+#endif
+
+                state->v3 ^= state->padding;
+                sipround(state);
+                sipround(state);
+                state->v0 ^= state->padding;
+
+                state->padding = 0;
+        }
+
+        end -= (state->inlen % sizeof(uint64_t));
+
+        for ( ; in < end; in += 8) {
+                m = unaligned_read_le64(in);
+#if ENABLE_DEBUG_SIPHASH
+                printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+                printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+                printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+                printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
+                printf("(%3zu) compress %08x %08x\n", state->inlen, (uint32_t) (m >> 32), (uint32_t) m);
+#endif
+                state->v3 ^= m;
+                sipround(state);
+                sipround(state);
+                state->v0 ^= m;
+        }
+
+        left = state->inlen & 7;
+        switch (left) {
+                case 7:
+                        state->padding |= ((uint64_t) in[6]) << 48;
+                        _fallthrough_;
+                case 6:
+                        state->padding |= ((uint64_t) in[5]) << 40;
+                        _fallthrough_;
+                case 5:
+                        state->padding |= ((uint64_t) in[4]) << 32;
+                        _fallthrough_;
+                case 4:
+                        state->padding |= ((uint64_t) in[3]) << 24;
+                        _fallthrough_;
+                case 3:
+                        state->padding |= ((uint64_t) in[2]) << 16;
+                        _fallthrough_;
+                case 2:
+                        state->padding |= ((uint64_t) in[1]) <<  8;
+                        _fallthrough_;
+                case 1:
+                        state->padding |= ((uint64_t) in[0]);
+                        _fallthrough_;
+                case 0:
+                        break;
+        }
+}
+
+uint64_t siphash24_finalize(struct siphash *state) {
+        uint64_t b;
+
+        assert(state);
+
+        b = state->padding | (((uint64_t) state->inlen) << 56);
+
+#if ENABLE_DEBUG_SIPHASH
+        printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+        printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+        printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+        printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
+        printf("(%3zu) padding   %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t) state->padding);
+#endif
+
+        state->v3 ^= b;
+        sipround(state);
+        sipround(state);
+        state->v0 ^= b;
+
+#if ENABLE_DEBUG_SIPHASH
+        printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+        printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+        printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+        printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
+#endif
+        state->v2 ^= 0xff;
+
+        sipround(state);
+        sipround(state);
+        sipround(state);
+        sipround(state);
+
+        return state->v0 ^ state->v1 ^ state->v2  ^ state->v3;
+}
+
+uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]) {
+        struct siphash state;
+
+        assert(in);
+        assert(k);
+
+        siphash24_init(&state, k);
+        siphash24_compress(in, inlen, &state);
+
+        return siphash24_finalize(&state);
+}
diff --git a/src/basic/siphash24.h b/src/basic/siphash24.h
new file mode 100644
index 0000000..67c4f75
--- /dev/null
+++ b/src/basic/siphash24.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/types.h>
+
+struct siphash {
+        uint64_t v0;
+        uint64_t v1;
+        uint64_t v2;
+        uint64_t v3;
+        uint64_t padding;
+        size_t inlen;
+};
+
+void siphash24_init(struct siphash *state, const uint8_t k[static 16]);
+void siphash24_compress(const void *in, size_t inlen, struct siphash *state);
+#define siphash24_compress_byte(byte, state) siphash24_compress((const uint8_t[]) { (byte) }, 1, (state))
+
+uint64_t siphash24_finalize(struct siphash *state);
+
+uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]);
+
+static inline uint64_t siphash24_string(const char *s, const uint8_t k[static 16]) {
+        return siphash24(s, strlen(s) + 1, k);
+}
diff --git a/src/basic/smack-util.c b/src/basic/smack-util.c
new file mode 100644
index 0000000..123d00e
--- /dev/null
+++ b/src/basic/smack-util.c
@@ -0,0 +1,289 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/***
+  Copyright © 2013 Intel Corporation
+
+  Author: Auke Kok <auke-jan.h.kok@intel.com>
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/xattr.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "log.h"
+#include "macro.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "smack-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "xattr-util.h"
+
+#if ENABLE_SMACK
+bool mac_smack_use(void) {
+        static int cached_use = -1;
+
+        if (cached_use < 0)
+                cached_use = access("/sys/fs/smackfs/", F_OK) >= 0;
+
+        return cached_use;
+}
+
+static const char* const smack_attr_table[_SMACK_ATTR_MAX] = {
+        [SMACK_ATTR_ACCESS]     = "security.SMACK64",
+        [SMACK_ATTR_EXEC]       = "security.SMACK64EXEC",
+        [SMACK_ATTR_MMAP]       = "security.SMACK64MMAP",
+        [SMACK_ATTR_TRANSMUTE]  = "security.SMACK64TRANSMUTE",
+        [SMACK_ATTR_IPIN]       = "security.SMACK64IPIN",
+        [SMACK_ATTR_IPOUT]      = "security.SMACK64IPOUT",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(smack_attr, SmackAttr);
+
+int mac_smack_read(const char *path, SmackAttr attr, char **label) {
+        assert(path);
+        assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+        assert(label);
+
+        if (!mac_smack_use())
+                return 0;
+
+        return getxattr_malloc(path, smack_attr_to_string(attr), label, true);
+}
+
+int mac_smack_read_fd(int fd, SmackAttr attr, char **label) {
+        assert(fd >= 0);
+        assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+        assert(label);
+
+        if (!mac_smack_use())
+                return 0;
+
+        return fgetxattr_malloc(fd, smack_attr_to_string(attr), label);
+}
+
+int mac_smack_apply(const char *path, SmackAttr attr, const char *label) {
+        int r;
+
+        assert(path);
+        assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+
+        if (!mac_smack_use())
+                return 0;
+
+        if (label)
+                r = lsetxattr(path, smack_attr_to_string(attr), label, strlen(label), 0);
+        else
+                r = lremovexattr(path, smack_attr_to_string(attr));
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) {
+        int r;
+
+        assert(fd >= 0);
+        assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+
+        if (!mac_smack_use())
+                return 0;
+
+        if (label)
+                r = fsetxattr(fd, smack_attr_to_string(attr), label, strlen(label), 0);
+        else
+                r = fremovexattr(fd, smack_attr_to_string(attr));
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+int mac_smack_apply_pid(pid_t pid, const char *label) {
+        const char *p;
+        int r = 0;
+
+        assert(label);
+
+        if (!mac_smack_use())
+                return 0;
+
+        p = procfs_file_alloca(pid, "attr/current");
+        r = write_string_file(p, label, WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0)
+                return r;
+
+        return r;
+}
+
+static int smack_fix_fd(int fd , const char *abspath, LabelFixFlags flags) {
+        char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
+        const char *label;
+        struct stat st;
+        int r;
+
+        /* The caller should have done the sanity checks. */
+        assert(abspath);
+        assert(path_is_absolute(abspath));
+
+        /* Path must be in /dev. */
+        if (!path_startswith(abspath, "/dev"))
+                return 0;
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        /*
+         * Label directories and character devices "*".
+         * Label symlinks "_".
+         * Don't change anything else.
+         */
+
+        if (S_ISDIR(st.st_mode))
+                label = SMACK_STAR_LABEL;
+        else if (S_ISLNK(st.st_mode))
+                label = SMACK_FLOOR_LABEL;
+        else if (S_ISCHR(st.st_mode))
+                label = SMACK_STAR_LABEL;
+        else
+                return 0;
+
+        xsprintf(procfs_path, "/proc/self/fd/%i", fd);
+        if (setxattr(procfs_path, "security.SMACK64", label, strlen(label), 0) < 0) {
+                _cleanup_free_ char *old_label = NULL;
+
+                r = -errno;
+
+                /* If the FS doesn't support labels, then exit without warning */
+                if (r == -EOPNOTSUPP)
+                        return 0;
+
+                /* It the FS is read-only and we were told to ignore failures caused by that, suppress error */
+                if (r == -EROFS && (flags & LABEL_IGNORE_EROFS))
+                        return 0;
+
+                /* If the old label is identical to the new one, suppress any kind of error */
+                if (getxattr_malloc(procfs_path, "security.SMACK64", &old_label, false) >= 0 &&
+                    streq(old_label, label))
+                        return 0;
+
+                return log_debug_errno(r, "Unable to fix SMACK label of %s: %m", abspath);
+        }
+
+        return 0;
+}
+
+int mac_smack_fix_at(int dirfd, const char *path, LabelFixFlags flags) {
+        _cleanup_free_ char *p = NULL;
+        _cleanup_close_ int fd = -1;
+        int r;
+
+        assert(path);
+
+        if (!mac_smack_use())
+                return 0;
+
+        fd = openat(dirfd, path, O_NOFOLLOW|O_CLOEXEC|O_PATH);
+        if (fd < 0) {
+                if ((flags & LABEL_IGNORE_ENOENT) && errno == ENOENT)
+                        return 0;
+
+                return -errno;
+        }
+
+        if (!path_is_absolute(path)) {
+                r = fd_get_path(fd, &p);
+                if (r < 0)
+                        return r;
+                path = p;
+        }
+
+        return smack_fix_fd(fd, path, flags);
+}
+
+int mac_smack_fix(const char *path, LabelFixFlags flags) {
+        _cleanup_free_ char *abspath = NULL;
+        _cleanup_close_ int fd = -1;
+        int r;
+
+        assert(path);
+
+        if (!mac_smack_use())
+                return 0;
+
+        r = path_make_absolute_cwd(path, &abspath);
+        if (r < 0)
+                return r;
+
+        fd = open(abspath, O_NOFOLLOW|O_CLOEXEC|O_PATH);
+        if (fd < 0) {
+                if ((flags & LABEL_IGNORE_ENOENT) && errno == ENOENT)
+                        return 0;
+
+                return -errno;
+        }
+
+        return smack_fix_fd(fd, abspath, flags);
+}
+
+int mac_smack_copy(const char *dest, const char *src) {
+        int r = 0;
+        _cleanup_free_ char *label = NULL;
+
+        assert(dest);
+        assert(src);
+
+        r = mac_smack_read(src, SMACK_ATTR_ACCESS, &label);
+        if (r < 0)
+                return r;
+
+        r = mac_smack_apply(dest, SMACK_ATTR_ACCESS, label);
+        if (r < 0)
+                return r;
+
+        return r;
+}
+
+#else
+bool mac_smack_use(void) {
+        return false;
+}
+
+int mac_smack_read(const char *path, SmackAttr attr, char **label) {
+        return -EOPNOTSUPP;
+}
+
+int mac_smack_read_fd(int fd, SmackAttr attr, char **label) {
+        return -EOPNOTSUPP;
+}
+
+int mac_smack_apply(const char *path, SmackAttr attr, const char *label) {
+        return 0;
+}
+
+int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) {
+        return 0;
+}
+
+int mac_smack_apply_pid(pid_t pid, const char *label) {
+        return 0;
+}
+
+int mac_smack_fix(const char *path, LabelFixFlags flags) {
+        return 0;
+}
+
+int mac_smack_fix_at(int dirfd, const char *path, LabelFixFlags flags) {
+        return 0;
+}
+
+int mac_smack_copy(const char *dest, const char *src) {
+        return 0;
+}
+#endif
diff --git a/src/basic/smack-util.h b/src/basic/smack-util.h
new file mode 100644
index 0000000..395ec07
--- /dev/null
+++ b/src/basic/smack-util.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/***
+  Copyright © 2013 Intel Corporation
+
+  Author: Auke Kok <auke-jan.h.kok@intel.com>
+***/
+
+#include <stdbool.h>
+#include <sys/types.h>
+
+#include "label.h"
+#include "macro.h"
+
+#define SMACK_FLOOR_LABEL "_"
+#define SMACK_STAR_LABEL  "*"
+
+typedef enum SmackAttr {
+        SMACK_ATTR_ACCESS,
+        SMACK_ATTR_EXEC,
+        SMACK_ATTR_MMAP,
+        SMACK_ATTR_TRANSMUTE,
+        SMACK_ATTR_IPIN,
+        SMACK_ATTR_IPOUT,
+        _SMACK_ATTR_MAX,
+        _SMACK_ATTR_INVALID = -1,
+} SmackAttr;
+
+bool mac_smack_use(void);
+
+int mac_smack_fix(const char *path, LabelFixFlags flags);
+int mac_smack_fix_at(int dirfd, const char *path, LabelFixFlags flags);
+
+const char* smack_attr_to_string(SmackAttr i) _const_;
+SmackAttr smack_attr_from_string(const char *s) _pure_;
+int mac_smack_read(const char *path, SmackAttr attr, char **label);
+int mac_smack_read_fd(int fd, SmackAttr attr, char **label);
+int mac_smack_apply(const char *path, SmackAttr attr, const char *label);
+int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label);
+int mac_smack_apply_pid(pid_t pid, const char *label);
+int mac_smack_copy(const char *dest, const char *src);
diff --git a/src/basic/socket-label.c b/src/basic/socket-label.c
new file mode 100644
index 0000000..4ed19cd
--- /dev/null
+++ b/src/basic/socket-label.c
@@ -0,0 +1,163 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <netinet/in.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "mkdir.h"
+#include "selinux-util.h"
+#include "socket-util.h"
+#include "umask-util.h"
+
+int socket_address_listen(
+                const SocketAddress *a,
+                int flags,
+                int backlog,
+                SocketAddressBindIPv6Only only,
+                const char *bind_to_device,
+                bool reuse_port,
+                bool free_bind,
+                bool transparent,
+                mode_t directory_mode,
+                mode_t socket_mode,
+                const char *label) {
+
+        _cleanup_close_ int fd = -1;
+        const char *p;
+        int r;
+
+        assert(a);
+
+        r = socket_address_verify(a, true);
+        if (r < 0)
+                return r;
+
+        if (socket_address_family(a) == AF_INET6 && !socket_ipv6_is_supported())
+                return -EAFNOSUPPORT;
+
+        if (label) {
+                r = mac_selinux_create_socket_prepare(label);
+                if (r < 0)
+                        return r;
+        }
+
+        fd = socket(socket_address_family(a), a->type | flags, a->protocol);
+        r = fd < 0 ? -errno : 0;
+
+        if (label)
+                mac_selinux_create_socket_clear();
+
+        if (r < 0)
+                return r;
+
+        if (socket_address_family(a) == AF_INET6 && only != SOCKET_ADDRESS_DEFAULT) {
+                r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_V6ONLY, only == SOCKET_ADDRESS_IPV6_ONLY);
+                if (r < 0)
+                        return r;
+        }
+
+        if (IN_SET(socket_address_family(a), AF_INET, AF_INET6)) {
+                if (bind_to_device)
+                        if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, bind_to_device, strlen(bind_to_device)+1) < 0)
+                                return -errno;
+
+                if (reuse_port) {
+                        r = setsockopt_int(fd, SOL_SOCKET, SO_REUSEPORT, true);
+                        if (r < 0)
+                                log_warning_errno(r, "SO_REUSEPORT failed: %m");
+                }
+
+                if (free_bind) {
+                        r = setsockopt_int(fd, IPPROTO_IP, IP_FREEBIND, true);
+                        if (r < 0)
+                                log_warning_errno(r, "IP_FREEBIND failed: %m");
+                }
+
+                if (transparent) {
+                        r = setsockopt_int(fd, IPPROTO_IP, IP_TRANSPARENT, true);
+                        if (r < 0)
+                                log_warning_errno(r, "IP_TRANSPARENT failed: %m");
+                }
+        }
+
+        r = setsockopt_int(fd, SOL_SOCKET, SO_REUSEADDR, true);
+        if (r < 0)
+                return r;
+
+        p = socket_address_get_path(a);
+        if (p) {
+                /* Create parents */
+                (void) mkdir_parents_label(p, directory_mode);
+
+                /* Enforce the right access mode for the socket */
+                RUN_WITH_UMASK(~socket_mode) {
+                        r = mac_selinux_bind(fd, &a->sockaddr.sa, a->size);
+                        if (r == -EADDRINUSE) {
+                                /* Unlink and try again */
+
+                                if (unlink(p) < 0)
+                                        return r; /* didn't work, return original error */
+
+                                r = mac_selinux_bind(fd, &a->sockaddr.sa, a->size);
+                        }
+                        if (r < 0)
+                                return r;
+                }
+        } else {
+                if (bind(fd, &a->sockaddr.sa, a->size) < 0)
+                        return -errno;
+        }
+
+        if (socket_address_can_accept(a))
+                if (listen(fd, backlog) < 0)
+                        return -errno;
+
+        /* Let's trigger an inotify event on the socket node, so that anyone waiting for this socket to be connectable
+         * gets notified */
+        if (p)
+                (void) touch(p);
+
+        r = fd;
+        fd = -1;
+
+        return r;
+}
+
+int make_socket_fd(int log_level, const char* address, int type, int flags) {
+        SocketAddress a;
+        int fd, r;
+
+        r = socket_address_parse(&a, address);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse socket address \"%s\": %m", address);
+
+        a.type = type;
+
+        fd = socket_address_listen(&a, type | flags, SOMAXCONN, SOCKET_ADDRESS_DEFAULT,
+                                   NULL, false, false, false, 0755, 0644, NULL);
+        if (fd < 0 || log_get_max_level() >= log_level) {
+                _cleanup_free_ char *p = NULL;
+
+                r = socket_address_print(&a, &p);
+                if (r < 0)
+                        return log_error_errno(r, "socket_address_print(): %m");
+
+                if (fd < 0)
+                        log_error_errno(fd, "Failed to listen on %s: %m", p);
+                else
+                        log_full(log_level, "Listening on %s", p);
+        }
+
+        return fd;
+}
diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
new file mode 100644
index 0000000..91bf801
--- /dev/null
+++ b/src/basic/socket-util.c
@@ -0,0 +1,1347 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <limits.h>
+#include <net/if.h>
+#include <netdb.h>
+#include <netinet/ip.h>
+#include <poll.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "escape.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "socket-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "user-util.h"
+#include "utf8.h"
+#include "util.h"
+
+#if ENABLE_IDN
+#  define IDN_FLAGS NI_IDN
+#else
+#  define IDN_FLAGS 0
+#endif
+
+static const char* const socket_address_type_table[] = {
+        [SOCK_STREAM] = "Stream",
+        [SOCK_DGRAM] = "Datagram",
+        [SOCK_RAW] = "Raw",
+        [SOCK_RDM] = "ReliableDatagram",
+        [SOCK_SEQPACKET] = "SequentialPacket",
+        [SOCK_DCCP] = "DatagramCongestionControl",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(socket_address_type, int);
+
+int socket_address_parse(SocketAddress *a, const char *s) {
+        _cleanup_free_ char *n = NULL;
+        char *e;
+        int r;
+
+        assert(a);
+        assert(s);
+
+        *a = (SocketAddress) {
+                .type = SOCK_STREAM,
+        };
+
+        if (*s == '[') {
+                uint16_t port;
+
+                /* IPv6 in [x:.....:z]:p notation */
+
+                e = strchr(s+1, ']');
+                if (!e)
+                        return -EINVAL;
+
+                n = strndup(s+1, e-s-1);
+                if (!n)
+                        return -ENOMEM;
+
+                errno = 0;
+                if (inet_pton(AF_INET6, n, &a->sockaddr.in6.sin6_addr) <= 0)
+                        return errno > 0 ? -errno : -EINVAL;
+
+                e++;
+                if (*e != ':')
+                        return -EINVAL;
+
+                e++;
+                r = parse_ip_port(e, &port);
+                if (r < 0)
+                        return r;
+
+                a->sockaddr.in6.sin6_family = AF_INET6;
+                a->sockaddr.in6.sin6_port = htobe16(port);
+                a->size = sizeof(struct sockaddr_in6);
+
+        } else if (*s == '/') {
+                /* AF_UNIX socket */
+
+                size_t l;
+
+                l = strlen(s);
+                if (l >= sizeof(a->sockaddr.un.sun_path)) /* Note that we refuse non-NUL-terminated sockets when
+                                                           * parsing (the kernel itself is less strict here in what it
+                                                           * accepts) */
+                        return -EINVAL;
+
+                a->sockaddr.un.sun_family = AF_UNIX;
+                memcpy(a->sockaddr.un.sun_path, s, l);
+                a->size = offsetof(struct sockaddr_un, sun_path) + l + 1;
+
+        } else if (*s == '@') {
+                /* Abstract AF_UNIX socket */
+                size_t l;
+
+                l = strlen(s+1);
+                if (l >= sizeof(a->sockaddr.un.sun_path) - 1) /* Note that we refuse non-NUL-terminated sockets here
+                                                               * when parsing, even though abstract namespace sockets
+                                                               * explicitly allow embedded NUL bytes and don't consider
+                                                               * them special. But it's simply annoying to debug such
+                                                               * sockets. */
+                        return -EINVAL;
+
+                a->sockaddr.un.sun_family = AF_UNIX;
+                memcpy(a->sockaddr.un.sun_path+1, s+1, l);
+                a->size = offsetof(struct sockaddr_un, sun_path) + 1 + l;
+
+        } else if (startswith(s, "vsock:")) {
+                /* AF_VSOCK socket in vsock:cid:port notation */
+                const char *cid_start = s + STRLEN("vsock:");
+                unsigned port;
+
+                e = strchr(cid_start, ':');
+                if (!e)
+                        return -EINVAL;
+
+                r = safe_atou(e+1, &port);
+                if (r < 0)
+                        return r;
+
+                n = strndup(cid_start, e - cid_start);
+                if (!n)
+                        return -ENOMEM;
+
+                if (!isempty(n)) {
+                        r = safe_atou(n, &a->sockaddr.vm.svm_cid);
+                        if (r < 0)
+                                return r;
+                } else
+                        a->sockaddr.vm.svm_cid = VMADDR_CID_ANY;
+
+                a->sockaddr.vm.svm_family = AF_VSOCK;
+                a->sockaddr.vm.svm_port = port;
+                a->size = sizeof(struct sockaddr_vm);
+
+        } else {
+                uint16_t port;
+
+                e = strchr(s, ':');
+                if (e) {
+                        r = parse_ip_port(e + 1, &port);
+                        if (r < 0)
+                                return r;
+
+                        n = strndup(s, e-s);
+                        if (!n)
+                                return -ENOMEM;
+
+                        /* IPv4 in w.x.y.z:p notation? */
+                        r = inet_pton(AF_INET, n, &a->sockaddr.in.sin_addr);
+                        if (r < 0)
+                                return -errno;
+
+                        if (r > 0) {
+                                /* Gotcha, it's a traditional IPv4 address */
+                                a->sockaddr.in.sin_family = AF_INET;
+                                a->sockaddr.in.sin_port = htobe16(port);
+                                a->size = sizeof(struct sockaddr_in);
+                        } else {
+                                unsigned idx;
+
+                                if (strlen(n) > IF_NAMESIZE-1)
+                                        return -EINVAL;
+
+                                /* Uh, our last resort, an interface name */
+                                idx = if_nametoindex(n);
+                                if (idx == 0)
+                                        return -EINVAL;
+
+                                a->sockaddr.in6.sin6_family = AF_INET6;
+                                a->sockaddr.in6.sin6_port = htobe16(port);
+                                a->sockaddr.in6.sin6_scope_id = idx;
+                                a->sockaddr.in6.sin6_addr = in6addr_any;
+                                a->size = sizeof(struct sockaddr_in6);
+                        }
+                } else {
+
+                        /* Just a port */
+                        r = parse_ip_port(s, &port);
+                        if (r < 0)
+                                return r;
+
+                        if (socket_ipv6_is_supported()) {
+                                a->sockaddr.in6.sin6_family = AF_INET6;
+                                a->sockaddr.in6.sin6_port = htobe16(port);
+                                a->sockaddr.in6.sin6_addr = in6addr_any;
+                                a->size = sizeof(struct sockaddr_in6);
+                        } else {
+                                a->sockaddr.in.sin_family = AF_INET;
+                                a->sockaddr.in.sin_port = htobe16(port);
+                                a->sockaddr.in.sin_addr.s_addr = INADDR_ANY;
+                                a->size = sizeof(struct sockaddr_in);
+                        }
+                }
+        }
+
+        return 0;
+}
+
+int socket_address_parse_and_warn(SocketAddress *a, const char *s) {
+        SocketAddress b;
+        int r;
+
+        /* Similar to socket_address_parse() but warns for IPv6 sockets when we don't support them. */
+
+        r = socket_address_parse(&b, s);
+        if (r < 0)
+                return r;
+
+        if (!socket_ipv6_is_supported() && b.sockaddr.sa.sa_family == AF_INET6) {
+                log_warning("Binding to IPv6 address not available since kernel does not support IPv6.");
+                return -EAFNOSUPPORT;
+        }
+
+        *a = b;
+        return 0;
+}
+
+int socket_address_parse_netlink(SocketAddress *a, const char *s) {
+        int family;
+        unsigned group = 0;
+        _cleanup_free_ char *sfamily = NULL;
+        assert(a);
+        assert(s);
+
+        zero(*a);
+        a->type = SOCK_RAW;
+
+        errno = 0;
+        if (sscanf(s, "%ms %u", &sfamily, &group) < 1)
+                return errno > 0 ? -errno : -EINVAL;
+
+        family = netlink_family_from_string(sfamily);
+        if (family < 0)
+                return -EINVAL;
+
+        a->sockaddr.nl.nl_family = AF_NETLINK;
+        a->sockaddr.nl.nl_groups = group;
+
+        a->type = SOCK_RAW;
+        a->size = sizeof(struct sockaddr_nl);
+        a->protocol = family;
+
+        return 0;
+}
+
+int socket_address_verify(const SocketAddress *a, bool strict) {
+        assert(a);
+
+        /* With 'strict' we enforce additional sanity constraints which are not set by the standard,
+         * but should only apply to sockets we create ourselves. */
+
+        switch (socket_address_family(a)) {
+
+        case AF_INET:
+                if (a->size != sizeof(struct sockaddr_in))
+                        return -EINVAL;
+
+                if (a->sockaddr.in.sin_port == 0)
+                        return -EINVAL;
+
+                if (!IN_SET(a->type, SOCK_STREAM, SOCK_DGRAM))
+                        return -EINVAL;
+
+                return 0;
+
+        case AF_INET6:
+                if (a->size != sizeof(struct sockaddr_in6))
+                        return -EINVAL;
+
+                if (a->sockaddr.in6.sin6_port == 0)
+                        return -EINVAL;
+
+                if (!IN_SET(a->type, SOCK_STREAM, SOCK_DGRAM))
+                        return -EINVAL;
+
+                return 0;
+
+        case AF_UNIX:
+                if (a->size < offsetof(struct sockaddr_un, sun_path))
+                        return -EINVAL;
+                if (a->size > sizeof(struct sockaddr_un) + !strict)
+                        /* If !strict, allow one extra byte, since getsockname() on Linux will append
+                         * a NUL byte if we have path sockets that are above sun_path's full size. */
+                        return -EINVAL;
+
+                if (a->size > offsetof(struct sockaddr_un, sun_path) &&
+                    a->sockaddr.un.sun_path[0] != 0 &&
+                    strict) {
+                        /* Only validate file system sockets here, and only in strict mode */
+                        const char *e;
+
+                        e = memchr(a->sockaddr.un.sun_path, 0, sizeof(a->sockaddr.un.sun_path));
+                        if (e) {
+                                /* If there's an embedded NUL byte, make sure the size of the socket address matches it */
+                                if (a->size != offsetof(struct sockaddr_un, sun_path) + (e - a->sockaddr.un.sun_path) + 1)
+                                        return -EINVAL;
+                        } else {
+                                /* If there's no embedded NUL byte, then then the size needs to match the whole
+                                 * structure or the structure with one extra NUL byte suffixed. (Yeah, Linux is awful,
+                                 * and considers both equivalent: getsockname() even extends sockaddr_un beyond its
+                                 * size if the path is non NUL terminated.)*/
+                                if (!IN_SET(a->size, sizeof(a->sockaddr.un.sun_path), sizeof(a->sockaddr.un.sun_path)+1))
+                                        return -EINVAL;
+                        }
+                }
+
+                if (!IN_SET(a->type, SOCK_STREAM, SOCK_DGRAM, SOCK_SEQPACKET))
+                        return -EINVAL;
+
+                return 0;
+
+        case AF_NETLINK:
+
+                if (a->size != sizeof(struct sockaddr_nl))
+                        return -EINVAL;
+
+                if (!IN_SET(a->type, SOCK_RAW, SOCK_DGRAM))
+                        return -EINVAL;
+
+                return 0;
+
+        case AF_VSOCK:
+                if (a->size != sizeof(struct sockaddr_vm))
+                        return -EINVAL;
+
+                if (!IN_SET(a->type, SOCK_STREAM, SOCK_DGRAM))
+                        return -EINVAL;
+
+                return 0;
+
+        default:
+                return -EAFNOSUPPORT;
+        }
+}
+
+int socket_address_print(const SocketAddress *a, char **ret) {
+        int r;
+
+        assert(a);
+        assert(ret);
+
+        r = socket_address_verify(a, false); /* We do non-strict validation, because we want to be
+                                              * able to pretty-print any socket the kernel considers
+                                              * valid. We still need to do validation to know if we
+                                              * can meaningfully print the address. */
+        if (r < 0)
+                return r;
+
+        if (socket_address_family(a) == AF_NETLINK) {
+                _cleanup_free_ char *sfamily = NULL;
+
+                r = netlink_family_to_string_alloc(a->protocol, &sfamily);
+                if (r < 0)
+                        return r;
+
+                r = asprintf(ret, "%s %u", sfamily, a->sockaddr.nl.nl_groups);
+                if (r < 0)
+                        return -ENOMEM;
+
+                return 0;
+        }
+
+        return sockaddr_pretty(&a->sockaddr.sa, a->size, false, true, ret);
+}
+
+bool socket_address_can_accept(const SocketAddress *a) {
+        assert(a);
+
+        return
+                IN_SET(a->type, SOCK_STREAM, SOCK_SEQPACKET);
+}
+
+bool socket_address_equal(const SocketAddress *a, const SocketAddress *b) {
+        assert(a);
+        assert(b);
+
+        /* Invalid addresses are unequal to all */
+        if (socket_address_verify(a, false) < 0 ||
+            socket_address_verify(b, false) < 0)
+                return false;
+
+        if (a->type != b->type)
+                return false;
+
+        if (socket_address_family(a) != socket_address_family(b))
+                return false;
+
+        switch (socket_address_family(a)) {
+
+        case AF_INET:
+                if (a->sockaddr.in.sin_addr.s_addr != b->sockaddr.in.sin_addr.s_addr)
+                        return false;
+
+                if (a->sockaddr.in.sin_port != b->sockaddr.in.sin_port)
+                        return false;
+
+                break;
+
+        case AF_INET6:
+                if (memcmp(&a->sockaddr.in6.sin6_addr, &b->sockaddr.in6.sin6_addr, sizeof(a->sockaddr.in6.sin6_addr)) != 0)
+                        return false;
+
+                if (a->sockaddr.in6.sin6_port != b->sockaddr.in6.sin6_port)
+                        return false;
+
+                break;
+
+        case AF_UNIX:
+                if (a->size <= offsetof(struct sockaddr_un, sun_path) ||
+                    b->size <= offsetof(struct sockaddr_un, sun_path))
+                        return false;
+
+                if ((a->sockaddr.un.sun_path[0] == 0) != (b->sockaddr.un.sun_path[0] == 0))
+                        return false;
+
+                if (a->sockaddr.un.sun_path[0]) {
+                        if (!path_equal_or_files_same(a->sockaddr.un.sun_path, b->sockaddr.un.sun_path, 0))
+                                return false;
+                } else {
+                        if (a->size != b->size)
+                                return false;
+
+                        if (memcmp(a->sockaddr.un.sun_path, b->sockaddr.un.sun_path, a->size) != 0)
+                                return false;
+                }
+
+                break;
+
+        case AF_NETLINK:
+                if (a->protocol != b->protocol)
+                        return false;
+
+                if (a->sockaddr.nl.nl_groups != b->sockaddr.nl.nl_groups)
+                        return false;
+
+                break;
+
+        case AF_VSOCK:
+                if (a->sockaddr.vm.svm_cid != b->sockaddr.vm.svm_cid)
+                        return false;
+
+                if (a->sockaddr.vm.svm_port != b->sockaddr.vm.svm_port)
+                        return false;
+
+                break;
+
+        default:
+                /* Cannot compare, so we assume the addresses are different */
+                return false;
+        }
+
+        return true;
+}
+
+bool socket_address_is(const SocketAddress *a, const char *s, int type) {
+        struct SocketAddress b;
+
+        assert(a);
+        assert(s);
+
+        if (socket_address_parse(&b, s) < 0)
+                return false;
+
+        b.type = type;
+
+        return socket_address_equal(a, &b);
+}
+
+bool socket_address_is_netlink(const SocketAddress *a, const char *s) {
+        struct SocketAddress b;
+
+        assert(a);
+        assert(s);
+
+        if (socket_address_parse_netlink(&b, s) < 0)
+                return false;
+
+        return socket_address_equal(a, &b);
+}
+
+const char* socket_address_get_path(const SocketAddress *a) {
+        assert(a);
+
+        if (socket_address_family(a) != AF_UNIX)
+                return NULL;
+
+        if (a->sockaddr.un.sun_path[0] == 0)
+                return NULL;
+
+        /* Note that this is only safe because we know that there's an extra NUL byte after the sockaddr_un
+         * structure. On Linux AF_UNIX file system socket addresses don't have to be NUL terminated if they take up the
+         * full sun_path space. */
+        assert_cc(sizeof(union sockaddr_union) >= sizeof(struct sockaddr_un)+1);
+        return a->sockaddr.un.sun_path;
+}
+
+bool socket_ipv6_is_supported(void) {
+        if (access("/proc/net/if_inet6", F_OK) != 0)
+                return false;
+
+        return true;
+}
+
+bool socket_address_matches_fd(const SocketAddress *a, int fd) {
+        SocketAddress b;
+        socklen_t solen;
+
+        assert(a);
+        assert(fd >= 0);
+
+        b.size = sizeof(b.sockaddr);
+        if (getsockname(fd, &b.sockaddr.sa, &b.size) < 0)
+                return false;
+
+        if (b.sockaddr.sa.sa_family != a->sockaddr.sa.sa_family)
+                return false;
+
+        solen = sizeof(b.type);
+        if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &b.type, &solen) < 0)
+                return false;
+
+        if (b.type != a->type)
+                return false;
+
+        if (a->protocol != 0)  {
+                solen = sizeof(b.protocol);
+                if (getsockopt(fd, SOL_SOCKET, SO_PROTOCOL, &b.protocol, &solen) < 0)
+                        return false;
+
+                if (b.protocol != a->protocol)
+                        return false;
+        }
+
+        return socket_address_equal(a, &b);
+}
+
+int sockaddr_port(const struct sockaddr *_sa, unsigned *ret_port) {
+        union sockaddr_union *sa = (union sockaddr_union*) _sa;
+
+        /* Note, this returns the port as 'unsigned' rather than 'uint16_t', as AF_VSOCK knows larger ports */
+
+        assert(sa);
+
+        switch (sa->sa.sa_family) {
+
+        case AF_INET:
+                *ret_port = be16toh(sa->in.sin_port);
+                return 0;
+
+        case AF_INET6:
+                *ret_port = be16toh(sa->in6.sin6_port);
+                return 0;
+
+        case AF_VSOCK:
+                *ret_port = sa->vm.svm_port;
+                return 0;
+
+        default:
+                return -EAFNOSUPPORT;
+        }
+}
+
+int sockaddr_pretty(
+                const struct sockaddr *_sa,
+                socklen_t salen,
+                bool translate_ipv6,
+                bool include_port,
+                char **ret) {
+
+        union sockaddr_union *sa = (union sockaddr_union*) _sa;
+        char *p;
+        int r;
+
+        assert(sa);
+        assert(salen >= sizeof(sa->sa.sa_family));
+
+        switch (sa->sa.sa_family) {
+
+        case AF_INET: {
+                uint32_t a;
+
+                a = be32toh(sa->in.sin_addr.s_addr);
+
+                if (include_port)
+                        r = asprintf(&p,
+                                     "%u.%u.%u.%u:%u",
+                                     a >> 24, (a >> 16) & 0xFF, (a >> 8) & 0xFF, a & 0xFF,
+                                     be16toh(sa->in.sin_port));
+                else
+                        r = asprintf(&p,
+                                     "%u.%u.%u.%u",
+                                     a >> 24, (a >> 16) & 0xFF, (a >> 8) & 0xFF, a & 0xFF);
+                if (r < 0)
+                        return -ENOMEM;
+                break;
+        }
+
+        case AF_INET6: {
+                static const unsigned char ipv4_prefix[] = {
+                        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF
+                };
+
+                if (translate_ipv6 &&
+                    memcmp(&sa->in6.sin6_addr, ipv4_prefix, sizeof(ipv4_prefix)) == 0) {
+                        const uint8_t *a = sa->in6.sin6_addr.s6_addr+12;
+                        if (include_port)
+                                r = asprintf(&p,
+                                             "%u.%u.%u.%u:%u",
+                                             a[0], a[1], a[2], a[3],
+                                             be16toh(sa->in6.sin6_port));
+                        else
+                                r = asprintf(&p,
+                                             "%u.%u.%u.%u",
+                                             a[0], a[1], a[2], a[3]);
+                        if (r < 0)
+                                return -ENOMEM;
+                } else {
+                        char a[INET6_ADDRSTRLEN];
+
+                        inet_ntop(AF_INET6, &sa->in6.sin6_addr, a, sizeof(a));
+
+                        if (include_port) {
+                                r = asprintf(&p,
+                                             "[%s]:%u",
+                                             a,
+                                             be16toh(sa->in6.sin6_port));
+                                if (r < 0)
+                                        return -ENOMEM;
+                        } else {
+                                p = strdup(a);
+                                if (!p)
+                                        return -ENOMEM;
+                        }
+                }
+
+                break;
+        }
+
+        case AF_UNIX:
+                if (salen <= offsetof(struct sockaddr_un, sun_path) ||
+                    (sa->un.sun_path[0] == 0 && salen == offsetof(struct sockaddr_un, sun_path) + 1))
+                        /* The name must have at least one character (and the leading NUL does not count) */
+                        p = strdup("<unnamed>");
+                else {
+                        /* Note that we calculate the path pointer here through the .un_buffer[] field, in order to
+                         * outtrick bounds checking tools such as ubsan, which are too smart for their own good: on
+                         * Linux the kernel may return sun_path[] data one byte longer than the declared size of the
+                         * field. */
+                        char *path = (char*) sa->un_buffer + offsetof(struct sockaddr_un, sun_path);
+                        size_t path_len = salen - offsetof(struct sockaddr_un, sun_path);
+
+                        if (path[0] == 0) {
+                                /* Abstract socket. When parsing address information from, we
+                                 * explicitly reject overly long paths and paths with embedded NULs.
+                                 * But we might get such a socket from the outside. Let's return
+                                 * something meaningful and printable in this case. */
+
+                                _cleanup_free_ char *e = NULL;
+
+                                e = cescape_length(path + 1, path_len - 1);
+                                if (!e)
+                                        return -ENOMEM;
+
+                                p = strjoin("@", e);
+                        } else {
+                                if (path[path_len - 1] == '\0')
+                                        /* We expect a terminating NUL and don't print it */
+                                        path_len --;
+
+                                p = cescape_length(path, path_len);
+                        }
+                }
+                if (!p)
+                        return -ENOMEM;
+
+                break;
+
+        case AF_VSOCK:
+                if (include_port) {
+                        if (sa->vm.svm_cid == VMADDR_CID_ANY)
+                                r = asprintf(&p, "vsock::%u", sa->vm.svm_port);
+                        else
+                                r = asprintf(&p, "vsock:%u:%u", sa->vm.svm_cid, sa->vm.svm_port);
+                } else
+                        r = asprintf(&p, "vsock:%u", sa->vm.svm_cid);
+                if (r < 0)
+                        return -ENOMEM;
+                break;
+
+        default:
+                return -EOPNOTSUPP;
+        }
+
+        *ret = p;
+        return 0;
+}
+
+int getpeername_pretty(int fd, bool include_port, char **ret) {
+        union sockaddr_union sa;
+        socklen_t salen = sizeof(sa);
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        if (getpeername(fd, &sa.sa, &salen) < 0)
+                return -errno;
+
+        if (sa.sa.sa_family == AF_UNIX) {
+                struct ucred ucred = {};
+
+                /* UNIX connection sockets are anonymous, so let's use
+                 * PID/UID as pretty credentials instead */
+
+                r = getpeercred(fd, &ucred);
+                if (r < 0)
+                        return r;
+
+                if (asprintf(ret, "PID "PID_FMT"/UID "UID_FMT, ucred.pid, ucred.uid) < 0)
+                        return -ENOMEM;
+
+                return 0;
+        }
+
+        /* For remote sockets we translate IPv6 addresses back to IPv4
+         * if applicable, since that's nicer. */
+
+        return sockaddr_pretty(&sa.sa, salen, true, include_port, ret);
+}
+
+int getsockname_pretty(int fd, char **ret) {
+        union sockaddr_union sa;
+        socklen_t salen = sizeof(sa);
+
+        assert(fd >= 0);
+        assert(ret);
+
+        if (getsockname(fd, &sa.sa, &salen) < 0)
+                return -errno;
+
+        /* For local sockets we do not translate IPv6 addresses back
+         * to IPv6 if applicable, since this is usually used for
+         * listening sockets where the difference between IPv4 and
+         * IPv6 matters. */
+
+        return sockaddr_pretty(&sa.sa, salen, false, true, ret);
+}
+
+int socknameinfo_pretty(union sockaddr_union *sa, socklen_t salen, char **_ret) {
+        int r;
+        char host[NI_MAXHOST], *ret;
+
+        assert(_ret);
+
+        r = getnameinfo(&sa->sa, salen, host, sizeof(host), NULL, 0, IDN_FLAGS);
+        if (r != 0) {
+                int saved_errno = errno;
+
+                r = sockaddr_pretty(&sa->sa, salen, true, true, &ret);
+                if (r < 0)
+                        return r;
+
+                log_debug_errno(saved_errno, "getnameinfo(%s) failed: %m", ret);
+        } else {
+                ret = strdup(host);
+                if (!ret)
+                        return -ENOMEM;
+        }
+
+        *_ret = ret;
+        return 0;
+}
+
+static const char* const netlink_family_table[] = {
+        [NETLINK_ROUTE] = "route",
+        [NETLINK_FIREWALL] = "firewall",
+        [NETLINK_INET_DIAG] = "inet-diag",
+        [NETLINK_NFLOG] = "nflog",
+        [NETLINK_XFRM] = "xfrm",
+        [NETLINK_SELINUX] = "selinux",
+        [NETLINK_ISCSI] = "iscsi",
+        [NETLINK_AUDIT] = "audit",
+        [NETLINK_FIB_LOOKUP] = "fib-lookup",
+        [NETLINK_CONNECTOR] = "connector",
+        [NETLINK_NETFILTER] = "netfilter",
+        [NETLINK_IP6_FW] = "ip6-fw",
+        [NETLINK_DNRTMSG] = "dnrtmsg",
+        [NETLINK_KOBJECT_UEVENT] = "kobject-uevent",
+        [NETLINK_GENERIC] = "generic",
+        [NETLINK_SCSITRANSPORT] = "scsitransport",
+        [NETLINK_ECRYPTFS] = "ecryptfs",
+        [NETLINK_RDMA] = "rdma",
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(netlink_family, int, INT_MAX);
+
+static const char* const socket_address_bind_ipv6_only_table[_SOCKET_ADDRESS_BIND_IPV6_ONLY_MAX] = {
+        [SOCKET_ADDRESS_DEFAULT] = "default",
+        [SOCKET_ADDRESS_BOTH] = "both",
+        [SOCKET_ADDRESS_IPV6_ONLY] = "ipv6-only"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(socket_address_bind_ipv6_only, SocketAddressBindIPv6Only);
+
+SocketAddressBindIPv6Only socket_address_bind_ipv6_only_or_bool_from_string(const char *n) {
+        int r;
+
+        r = parse_boolean(n);
+        if (r > 0)
+                return SOCKET_ADDRESS_IPV6_ONLY;
+        if (r == 0)
+                return SOCKET_ADDRESS_BOTH;
+
+        return socket_address_bind_ipv6_only_from_string(n);
+}
+
+bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b) {
+        assert(a);
+        assert(b);
+
+        if (a->sa.sa_family != b->sa.sa_family)
+                return false;
+
+        if (a->sa.sa_family == AF_INET)
+                return a->in.sin_addr.s_addr == b->in.sin_addr.s_addr;
+
+        if (a->sa.sa_family == AF_INET6)
+                return memcmp(&a->in6.sin6_addr, &b->in6.sin6_addr, sizeof(a->in6.sin6_addr)) == 0;
+
+        if (a->sa.sa_family == AF_VSOCK)
+                return a->vm.svm_cid == b->vm.svm_cid;
+
+        return false;
+}
+
+int fd_inc_sndbuf(int fd, size_t n) {
+        int r, value;
+        socklen_t l = sizeof(value);
+
+        r = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, &l);
+        if (r >= 0 && l == sizeof(value) && (size_t) value >= n*2)
+                return 0;
+
+        /* If we have the privileges we will ignore the kernel limit. */
+
+        if (setsockopt_int(fd, SOL_SOCKET, SO_SNDBUF, n) < 0) {
+                r = setsockopt_int(fd, SOL_SOCKET, SO_SNDBUFFORCE, n);
+                if (r < 0)
+                        return r;
+        }
+
+        return 1;
+}
+
+int fd_inc_rcvbuf(int fd, size_t n) {
+        int r, value;
+        socklen_t l = sizeof(value);
+
+        r = getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, &l);
+        if (r >= 0 && l == sizeof(value) && (size_t) value >= n*2)
+                return 0;
+
+        /* If we have the privileges we will ignore the kernel limit. */
+
+        if (setsockopt_int(fd, SOL_SOCKET, SO_RCVBUF, n) < 0) {
+                r = setsockopt_int(fd, SOL_SOCKET, SO_RCVBUFFORCE, n);
+                if (r < 0)
+                        return r;
+        }
+
+        return 1;
+}
+
+static const char* const ip_tos_table[] = {
+        [IPTOS_LOWDELAY] = "low-delay",
+        [IPTOS_THROUGHPUT] = "throughput",
+        [IPTOS_RELIABILITY] = "reliability",
+        [IPTOS_LOWCOST] = "low-cost",
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos, int, 0xff);
+
+bool ifname_valid(const char *p) {
+        bool numeric = true;
+
+        /* Checks whether a network interface name is valid. This is inspired by dev_valid_name() in the kernel sources
+         * but slightly stricter, as we only allow non-control, non-space ASCII characters in the interface name. We
+         * also don't permit names that only container numbers, to avoid confusion with numeric interface indexes. */
+
+        if (isempty(p))
+                return false;
+
+        if (strlen(p) >= IFNAMSIZ)
+                return false;
+
+        if (dot_or_dot_dot(p))
+                return false;
+
+        while (*p) {
+                if ((unsigned char) *p >= 127U)
+                        return false;
+
+                if ((unsigned char) *p <= 32U)
+                        return false;
+
+                if (IN_SET(*p, ':', '/'))
+                        return false;
+
+                numeric = numeric && (*p >= '0' && *p <= '9');
+                p++;
+        }
+
+        if (numeric)
+                return false;
+
+        return true;
+}
+
+bool address_label_valid(const char *p) {
+
+        if (isempty(p))
+                return false;
+
+        if (strlen(p) >= IFNAMSIZ)
+                return false;
+
+        while (*p) {
+                if ((uint8_t) *p >= 127U)
+                        return false;
+
+                if ((uint8_t) *p <= 31U)
+                        return false;
+                p++;
+        }
+
+        return true;
+}
+
+int getpeercred(int fd, struct ucred *ucred) {
+        socklen_t n = sizeof(struct ucred);
+        struct ucred u;
+        int r;
+
+        assert(fd >= 0);
+        assert(ucred);
+
+        r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &u, &n);
+        if (r < 0)
+                return -errno;
+
+        if (n != sizeof(struct ucred))
+                return -EIO;
+
+        /* Check if the data is actually useful and not suppressed due to namespacing issues */
+        if (!pid_is_valid(u.pid))
+                return -ENODATA;
+
+        /* Note that we don't check UID/GID here, as namespace translation works differently there: instead of
+         * receiving in "invalid" user/group we get the overflow UID/GID. */
+
+        *ucred = u;
+        return 0;
+}
+
+int getpeersec(int fd, char **ret) {
+        _cleanup_free_ char *s = NULL;
+        socklen_t n = 64;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        for (;;) {
+                s = new0(char, n+1);
+                if (!s)
+                        return -ENOMEM;
+
+                if (getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n) >= 0)
+                        break;
+
+                if (errno != ERANGE)
+                        return -errno;
+
+                s = mfree(s);
+        }
+
+        if (isempty(s))
+                return -EOPNOTSUPP;
+
+        *ret = TAKE_PTR(s);
+
+        return 0;
+}
+
+int getpeergroups(int fd, gid_t **ret) {
+        socklen_t n = sizeof(gid_t) * 64;
+        _cleanup_free_ gid_t *d = NULL;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        for (;;) {
+                d = malloc(n);
+                if (!d)
+                        return -ENOMEM;
+
+                if (getsockopt(fd, SOL_SOCKET, SO_PEERGROUPS, d, &n) >= 0)
+                        break;
+
+                if (errno != ERANGE)
+                        return -errno;
+
+                d = mfree(d);
+        }
+
+        assert_se(n % sizeof(gid_t) == 0);
+        n /= sizeof(gid_t);
+
+        if ((socklen_t) (int) n != n)
+                return -E2BIG;
+
+        *ret = TAKE_PTR(d);
+
+        return (int) n;
+}
+
+ssize_t send_one_fd_iov_sa(
+                int transport_fd,
+                int fd,
+                struct iovec *iov, size_t iovlen,
+                const struct sockaddr *sa, socklen_t len,
+                int flags) {
+
+        union {
+                struct cmsghdr cmsghdr;
+                uint8_t buf[CMSG_SPACE(sizeof(int))];
+        } control = {};
+        struct msghdr mh = {
+                .msg_name = (struct sockaddr*) sa,
+                .msg_namelen = len,
+                .msg_iov = iov,
+                .msg_iovlen = iovlen,
+        };
+        ssize_t k;
+
+        assert(transport_fd >= 0);
+
+        /*
+         * We need either an FD or data to send.
+         * If there's nothing, return an error.
+         */
+        if (fd < 0 && !iov)
+                return -EINVAL;
+
+        if (fd >= 0) {
+                struct cmsghdr *cmsg;
+
+                mh.msg_control = &control;
+                mh.msg_controllen = sizeof(control);
+
+                cmsg = CMSG_FIRSTHDR(&mh);
+                cmsg->cmsg_level = SOL_SOCKET;
+                cmsg->cmsg_type = SCM_RIGHTS;
+                cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+                memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
+
+                mh.msg_controllen = CMSG_SPACE(sizeof(int));
+        }
+        k = sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags);
+        if (k < 0)
+                return (ssize_t) -errno;
+
+        return k;
+}
+
+int send_one_fd_sa(
+                int transport_fd,
+                int fd,
+                const struct sockaddr *sa, socklen_t len,
+                int flags) {
+
+        assert(fd >= 0);
+
+        return (int) send_one_fd_iov_sa(transport_fd, fd, NULL, 0, sa, len, flags);
+}
+
+ssize_t receive_one_fd_iov(
+                int transport_fd,
+                struct iovec *iov, size_t iovlen,
+                int flags,
+                int *ret_fd) {
+
+        union {
+                struct cmsghdr cmsghdr;
+                uint8_t buf[CMSG_SPACE(sizeof(int))];
+        } control = {};
+        struct msghdr mh = {
+                .msg_control = &control,
+                .msg_controllen = sizeof(control),
+                .msg_iov = iov,
+                .msg_iovlen = iovlen,
+        };
+        struct cmsghdr *cmsg, *found = NULL;
+        ssize_t k;
+
+        assert(transport_fd >= 0);
+        assert(ret_fd);
+
+        /*
+         * Receive a single FD via @transport_fd. We don't care for
+         * the transport-type. We retrieve a single FD at most, so for
+         * packet-based transports, the caller must ensure to send
+         * only a single FD per packet.  This is best used in
+         * combination with send_one_fd().
+         */
+
+        k = recvmsg(transport_fd, &mh, MSG_CMSG_CLOEXEC | flags);
+        if (k < 0)
+                return (ssize_t) -errno;
+
+        CMSG_FOREACH(cmsg, &mh) {
+                if (cmsg->cmsg_level == SOL_SOCKET &&
+                    cmsg->cmsg_type == SCM_RIGHTS &&
+                    cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
+                        assert(!found);
+                        found = cmsg;
+                        break;
+                }
+        }
+
+        if (!found)
+                cmsg_close_all(&mh);
+
+        /* If didn't receive an FD or any data, return an error. */
+        if (k == 0 && !found)
+                return -EIO;
+
+        if (found)
+                *ret_fd = *(int*) CMSG_DATA(found);
+        else
+                *ret_fd = -1;
+
+        return k;
+}
+
+int receive_one_fd(int transport_fd, int flags) {
+        int fd;
+        ssize_t k;
+
+        k = receive_one_fd_iov(transport_fd, NULL, 0, flags, &fd);
+        if (k == 0)
+                return fd;
+
+        /* k must be negative, since receive_one_fd_iov() only returns
+         * a positive value if data was received through the iov. */
+        assert(k < 0);
+        return (int) k;
+}
+
+ssize_t next_datagram_size_fd(int fd) {
+        ssize_t l;
+        int k;
+
+        /* This is a bit like FIONREAD/SIOCINQ, however a bit more powerful. The difference being: recv(MSG_PEEK) will
+         * actually cause the next datagram in the queue to be validated regarding checksums, which FIONREAD doesn't
+         * do. This difference is actually of major importance as we need to be sure that the size returned here
+         * actually matches what we will read with recvmsg() next, as otherwise we might end up allocating a buffer of
+         * the wrong size. */
+
+        l = recv(fd, NULL, 0, MSG_PEEK|MSG_TRUNC);
+        if (l < 0) {
+                if (IN_SET(errno, EOPNOTSUPP, EFAULT))
+                        goto fallback;
+
+                return -errno;
+        }
+        if (l == 0)
+                goto fallback;
+
+        return l;
+
+fallback:
+        k = 0;
+
+        /* Some sockets (AF_PACKET) do not support null-sized recv() with MSG_TRUNC set, let's fall back to FIONREAD
+         * for them. Checksums don't matter for raw sockets anyway, hence this should be fine. */
+
+        if (ioctl(fd, FIONREAD, &k) < 0)
+                return -errno;
+
+        return (ssize_t) k;
+}
+
+int flush_accept(int fd) {
+
+        struct pollfd pollfd = {
+                .fd = fd,
+                .events = POLLIN,
+        };
+        int r;
+
+        /* Similar to flush_fd() but flushes all incoming connection by accepting them and immediately closing them. */
+
+        for (;;) {
+                int cfd;
+
+                r = poll(&pollfd, 1, 0);
+                if (r < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        return -errno;
+
+                } else if (r == 0)
+                        return 0;
+
+                cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
+                if (cfd < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        if (errno == EAGAIN)
+                                return 0;
+
+                        return -errno;
+                }
+
+                close(cfd);
+        }
+}
+
+struct cmsghdr* cmsg_find(struct msghdr *mh, int level, int type, socklen_t length) {
+        struct cmsghdr *cmsg;
+
+        assert(mh);
+
+        CMSG_FOREACH(cmsg, mh)
+                if (cmsg->cmsg_level == level &&
+                    cmsg->cmsg_type == type &&
+                    (length == (socklen_t) -1 || length == cmsg->cmsg_len))
+                        return cmsg;
+
+        return NULL;
+}
+
+int socket_ioctl_fd(void) {
+        int fd;
+
+        /* Create a socket to invoke the various network interface ioctl()s on. Traditionally only AF_INET was good for
+         * that. Since kernel 4.6 AF_NETLINK works for this too. We first try to use AF_INET hence, but if that's not
+         * available (for example, because it is made unavailable via SECCOMP or such), we'll fall back to the more
+         * generic AF_NETLINK. */
+
+        fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC, 0);
+        if (fd < 0)
+                fd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, NETLINK_GENERIC);
+        if (fd < 0)
+                return -errno;
+
+        return fd;
+}
+
+int sockaddr_un_unlink(const struct sockaddr_un *sa) {
+        const char *p, * nul;
+
+        assert(sa);
+
+        if (sa->sun_family != AF_UNIX)
+                return -EPROTOTYPE;
+
+        if (sa->sun_path[0] == 0) /* Nothing to do for abstract sockets */
+                return 0;
+
+        /* The path in .sun_path is not necessarily NUL terminated. Let's fix that. */
+        nul = memchr(sa->sun_path, 0, sizeof(sa->sun_path));
+        if (nul)
+                p = sa->sun_path;
+        else
+                p = memdupa_suffix0(sa->sun_path, sizeof(sa->sun_path));
+
+        if (unlink(p) < 0)
+                return -errno;
+
+        return 1;
+}
+
+int sockaddr_un_set_path(struct sockaddr_un *ret, const char *path) {
+        size_t l;
+
+        assert(ret);
+        assert(path);
+
+        /* Initialize ret->sun_path from the specified argument. This will interpret paths starting with '@' as
+         * abstract namespace sockets, and those starting with '/' as regular filesystem sockets. It won't accept
+         * anything else (i.e. no relative paths), to avoid ambiguities. Note that this function cannot be used to
+         * reference paths in the abstract namespace that include NUL bytes in the name. */
+
+        l = strlen(path);
+        if (l == 0)
+                return -EINVAL;
+        if (!IN_SET(path[0], '/', '@'))
+                return -EINVAL;
+        if (path[1] == 0)
+                return -EINVAL;
+
+        /* Don't allow paths larger than the space in sockaddr_un. Note that we are a tiny bit more restrictive than
+         * the kernel is: we insist on NUL termination (both for abstract namespace and regular file system socket
+         * addresses!), which the kernel doesn't. We do this to reduce chance of incompatibility with other apps that
+         * do not expect non-NUL terminated file system path*/
+        if (l+1 > sizeof(ret->sun_path))
+                return -EINVAL;
+
+        *ret = (struct sockaddr_un) {
+                .sun_family = AF_UNIX,
+        };
+
+        if (path[0] == '@') {
+                /* Abstract namespace socket */
+                memcpy(ret->sun_path + 1, path + 1, l); /* copy *with* trailing NUL byte */
+                return (int) (offsetof(struct sockaddr_un, sun_path) + l); /* 🔥 *don't* 🔥 include trailing NUL in size */
+
+        } else {
+                assert(path[0] == '/');
+
+                /* File system socket */
+                memcpy(ret->sun_path, path, l + 1); /* copy *with* trailing NUL byte */
+                return (int) (offsetof(struct sockaddr_un, sun_path) + l + 1); /* include trailing NUL in size */
+        }
+}
diff --git a/src/basic/socket-util.h b/src/basic/socket-util.h
new file mode 100644
index 0000000..574d2b7
--- /dev/null
+++ b/src/basic/socket-util.h
@@ -0,0 +1,200 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+#include <linux/netlink.h>
+#include <linux/if_infiniband.h>
+#include <linux/if_packet.h>
+#include <netinet/ether.h>
+#include <netinet/in.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+
+#include "macro.h"
+#include "missing_socket.h"
+#include "sparse-endian.h"
+
+union sockaddr_union {
+        /* The minimal, abstract version */
+        struct sockaddr sa;
+
+        /* The libc provided version that allocates "enough room" for every protocol */
+        struct sockaddr_storage storage;
+
+        /* Protoctol-specific implementations */
+        struct sockaddr_in in;
+        struct sockaddr_in6 in6;
+        struct sockaddr_un un;
+        struct sockaddr_nl nl;
+        struct sockaddr_ll ll;
+        struct sockaddr_vm vm;
+
+        /* Ensure there is enough space to store Infiniband addresses */
+        uint8_t ll_buffer[offsetof(struct sockaddr_ll, sll_addr) + CONST_MAX(ETH_ALEN, INFINIBAND_ALEN)];
+
+        /* Ensure there is enough space after the AF_UNIX sun_path for one more NUL byte, just to be sure that the path
+         * component is always followed by at least one NUL byte. */
+        uint8_t un_buffer[sizeof(struct sockaddr_un) + 1];
+};
+
+typedef struct SocketAddress {
+        union sockaddr_union sockaddr;
+
+        /* We store the size here explicitly due to the weird
+         * sockaddr_un semantics for abstract sockets */
+        socklen_t size;
+
+        /* Socket type, i.e. SOCK_STREAM, SOCK_DGRAM, ... */
+        int type;
+
+        /* Socket protocol, IPPROTO_xxx, usually 0, except for netlink */
+        int protocol;
+} SocketAddress;
+
+typedef enum SocketAddressBindIPv6Only {
+        SOCKET_ADDRESS_DEFAULT,
+        SOCKET_ADDRESS_BOTH,
+        SOCKET_ADDRESS_IPV6_ONLY,
+        _SOCKET_ADDRESS_BIND_IPV6_ONLY_MAX,
+        _SOCKET_ADDRESS_BIND_IPV6_ONLY_INVALID = -1
+} SocketAddressBindIPv6Only;
+
+#define socket_address_family(a) ((a)->sockaddr.sa.sa_family)
+
+const char* socket_address_type_to_string(int t) _const_;
+int socket_address_type_from_string(const char *s) _pure_;
+
+int socket_address_parse(SocketAddress *a, const char *s);
+int socket_address_parse_and_warn(SocketAddress *a, const char *s);
+int socket_address_parse_netlink(SocketAddress *a, const char *s);
+int socket_address_print(const SocketAddress *a, char **p);
+int socket_address_verify(const SocketAddress *a, bool strict) _pure_;
+
+int sockaddr_un_unlink(const struct sockaddr_un *sa);
+
+static inline int socket_address_unlink(const SocketAddress *a) {
+        return socket_address_family(a) == AF_UNIX ? sockaddr_un_unlink(&a->sockaddr.un) : 0;
+}
+
+bool socket_address_can_accept(const SocketAddress *a) _pure_;
+
+int socket_address_listen(
+                const SocketAddress *a,
+                int flags,
+                int backlog,
+                SocketAddressBindIPv6Only only,
+                const char *bind_to_device,
+                bool reuse_port,
+                bool free_bind,
+                bool transparent,
+                mode_t directory_mode,
+                mode_t socket_mode,
+                const char *label);
+int make_socket_fd(int log_level, const char* address, int type, int flags);
+
+bool socket_address_is(const SocketAddress *a, const char *s, int type);
+bool socket_address_is_netlink(const SocketAddress *a, const char *s);
+
+bool socket_address_matches_fd(const SocketAddress *a, int fd);
+
+bool socket_address_equal(const SocketAddress *a, const SocketAddress *b) _pure_;
+
+const char* socket_address_get_path(const SocketAddress *a);
+
+bool socket_ipv6_is_supported(void);
+
+int sockaddr_port(const struct sockaddr *_sa, unsigned *port);
+
+int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_ipv6, bool include_port, char **ret);
+int getpeername_pretty(int fd, bool include_port, char **ret);
+int getsockname_pretty(int fd, char **ret);
+
+int socknameinfo_pretty(union sockaddr_union *sa, socklen_t salen, char **_ret);
+
+const char* socket_address_bind_ipv6_only_to_string(SocketAddressBindIPv6Only b) _const_;
+SocketAddressBindIPv6Only socket_address_bind_ipv6_only_from_string(const char *s) _pure_;
+SocketAddressBindIPv6Only socket_address_bind_ipv6_only_or_bool_from_string(const char *s);
+
+int netlink_family_to_string_alloc(int b, char **s);
+int netlink_family_from_string(const char *s) _pure_;
+
+bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b);
+
+int fd_inc_sndbuf(int fd, size_t n);
+int fd_inc_rcvbuf(int fd, size_t n);
+
+int ip_tos_to_string_alloc(int i, char **s);
+int ip_tos_from_string(const char *s);
+
+bool ifname_valid(const char *p);
+bool address_label_valid(const char *p);
+
+int getpeercred(int fd, struct ucred *ucred);
+int getpeersec(int fd, char **ret);
+int getpeergroups(int fd, gid_t **ret);
+
+ssize_t send_one_fd_iov_sa(
+                int transport_fd,
+                int fd,
+                struct iovec *iov, size_t iovlen,
+                const struct sockaddr *sa, socklen_t len,
+                int flags);
+int send_one_fd_sa(int transport_fd,
+                   int fd,
+                   const struct sockaddr *sa, socklen_t len,
+                   int flags);
+#define send_one_fd_iov(transport_fd, fd, iov, iovlen, flags) send_one_fd_iov_sa(transport_fd, fd, iov, iovlen, NULL, 0, flags)
+#define send_one_fd(transport_fd, fd, flags) send_one_fd_iov_sa(transport_fd, fd, NULL, 0, NULL, 0, flags)
+ssize_t receive_one_fd_iov(int transport_fd, struct iovec *iov, size_t iovlen, int flags, int *ret_fd);
+int receive_one_fd(int transport_fd, int flags);
+
+ssize_t next_datagram_size_fd(int fd);
+
+int flush_accept(int fd);
+
+#define CMSG_FOREACH(cmsg, mh)                                          \
+        for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
+
+struct cmsghdr* cmsg_find(struct msghdr *mh, int level, int type, socklen_t length);
+
+/*
+ * Certain hardware address types (e.g Infiniband) do not fit into sll_addr
+ * (8 bytes) and run over the structure. This macro returns the correct size that
+ * must be passed to kernel.
+ */
+#define SOCKADDR_LL_LEN(sa)                                             \
+        ({                                                              \
+                const struct sockaddr_ll *_sa = &(sa);                  \
+                size_t _mac_len = sizeof(_sa->sll_addr);                \
+                assert(_sa->sll_family == AF_PACKET);                   \
+                if (be16toh(_sa->sll_hatype) == ARPHRD_ETHER)           \
+                        _mac_len = MAX(_mac_len, (size_t) ETH_ALEN);    \
+                if (be16toh(_sa->sll_hatype) == ARPHRD_INFINIBAND)      \
+                        _mac_len = MAX(_mac_len, (size_t) INFINIBAND_ALEN); \
+                offsetof(struct sockaddr_ll, sll_addr) + _mac_len;      \
+        })
+
+/* Covers only file system and abstract AF_UNIX socket addresses, but not unnamed socket addresses. */
+#define SOCKADDR_UN_LEN(sa)                                             \
+        ({                                                              \
+                const struct sockaddr_un *_sa = &(sa);                  \
+                assert(_sa->sun_family == AF_UNIX);                     \
+                offsetof(struct sockaddr_un, sun_path) +                \
+                        (_sa->sun_path[0] == 0 ?                        \
+                         1 + strnlen(_sa->sun_path+1, sizeof(_sa->sun_path)-1) : \
+                         strnlen(_sa->sun_path, sizeof(_sa->sun_path))+1); \
+        })
+
+int socket_ioctl_fd(void);
+
+int sockaddr_un_set_path(struct sockaddr_un *ret, const char *path);
+
+static inline int setsockopt_int(int fd, int level, int optname, int value) {
+        if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
+                return -errno;
+
+        return 0;
+}
diff --git a/src/basic/sparse-endian.h b/src/basic/sparse-endian.h
new file mode 100644
index 0000000..9583dda
--- /dev/null
+++ b/src/basic/sparse-endian.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (c) 2012 Josh Triplett <josh@joshtriplett.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#pragma once
+
+#include <byteswap.h>
+#include <endian.h>
+#include <stdint.h>
+
+#ifdef __CHECKER__
+#define __sd_bitwise __attribute__((__bitwise__))
+#define __sd_force __attribute__((__force__))
+#else
+#define __sd_bitwise
+#define __sd_force
+#endif
+
+typedef uint16_t __sd_bitwise le16_t;
+typedef uint16_t __sd_bitwise be16_t;
+typedef uint32_t __sd_bitwise le32_t;
+typedef uint32_t __sd_bitwise be32_t;
+typedef uint64_t __sd_bitwise le64_t;
+typedef uint64_t __sd_bitwise be64_t;
+
+#undef htobe16
+#undef htole16
+#undef be16toh
+#undef le16toh
+#undef htobe32
+#undef htole32
+#undef be32toh
+#undef le32toh
+#undef htobe64
+#undef htole64
+#undef be64toh
+#undef le64toh
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define bswap_16_on_le(x) __bswap_16(x)
+#define bswap_32_on_le(x) __bswap_32(x)
+#define bswap_64_on_le(x) __bswap_64(x)
+#define bswap_16_on_be(x) (x)
+#define bswap_32_on_be(x) (x)
+#define bswap_64_on_be(x) (x)
+#elif __BYTE_ORDER == __BIG_ENDIAN
+#define bswap_16_on_le(x) (x)
+#define bswap_32_on_le(x) (x)
+#define bswap_64_on_le(x) (x)
+#define bswap_16_on_be(x) __bswap_16(x)
+#define bswap_32_on_be(x) __bswap_32(x)
+#define bswap_64_on_be(x) __bswap_64(x)
+#endif
+
+static inline le16_t htole16(uint16_t value) { return (le16_t __sd_force) bswap_16_on_be(value); }
+static inline le32_t htole32(uint32_t value) { return (le32_t __sd_force) bswap_32_on_be(value); }
+static inline le64_t htole64(uint64_t value) { return (le64_t __sd_force) bswap_64_on_be(value); }
+
+static inline be16_t htobe16(uint16_t value) { return (be16_t __sd_force) bswap_16_on_le(value); }
+static inline be32_t htobe32(uint32_t value) { return (be32_t __sd_force) bswap_32_on_le(value); }
+static inline be64_t htobe64(uint64_t value) { return (be64_t __sd_force) bswap_64_on_le(value); }
+
+static inline uint16_t le16toh(le16_t value) { return bswap_16_on_be((uint16_t __sd_force)value); }
+static inline uint32_t le32toh(le32_t value) { return bswap_32_on_be((uint32_t __sd_force)value); }
+static inline uint64_t le64toh(le64_t value) { return bswap_64_on_be((uint64_t __sd_force)value); }
+
+static inline uint16_t be16toh(be16_t value) { return bswap_16_on_le((uint16_t __sd_force)value); }
+static inline uint32_t be32toh(be32_t value) { return bswap_32_on_le((uint32_t __sd_force)value); }
+static inline uint64_t be64toh(be64_t value) { return bswap_64_on_le((uint64_t __sd_force)value); }
+
+#undef __sd_bitwise
+#undef __sd_force
diff --git a/src/basic/special.h b/src/basic/special.h
new file mode 100644
index 0000000..379a3d7
--- /dev/null
+++ b/src/basic/special.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#define SPECIAL_DEFAULT_TARGET "default.target"
+
+/* Shutdown targets */
+#define SPECIAL_UMOUNT_TARGET "umount.target"
+/* This is not really intended to be started by directly. This is
+ * mostly so that other targets (reboot/halt/poweroff) can depend on
+ * it to bring all services down that want to be brought down on
+ * system shutdown. */
+#define SPECIAL_SHUTDOWN_TARGET "shutdown.target"
+#define SPECIAL_HALT_TARGET "halt.target"
+#define SPECIAL_POWEROFF_TARGET "poweroff.target"
+#define SPECIAL_REBOOT_TARGET "reboot.target"
+#define SPECIAL_KEXEC_TARGET "kexec.target"
+#define SPECIAL_EXIT_TARGET "exit.target"
+#define SPECIAL_SUSPEND_TARGET "suspend.target"
+#define SPECIAL_HIBERNATE_TARGET "hibernate.target"
+#define SPECIAL_HYBRID_SLEEP_TARGET "hybrid-sleep.target"
+#define SPECIAL_SUSPEND_THEN_HIBERNATE_TARGET "suspend-then-hibernate.target"
+
+/* Special boot targets */
+#define SPECIAL_RESCUE_TARGET "rescue.target"
+#define SPECIAL_EMERGENCY_TARGET "emergency.target"
+#define SPECIAL_MULTI_USER_TARGET "multi-user.target"
+#define SPECIAL_GRAPHICAL_TARGET "graphical.target"
+
+/* Early boot targets */
+#define SPECIAL_SYSINIT_TARGET "sysinit.target"
+#define SPECIAL_SOCKETS_TARGET "sockets.target"
+#define SPECIAL_TIMERS_TARGET "timers.target"
+#define SPECIAL_PATHS_TARGET "paths.target"
+#define SPECIAL_LOCAL_FS_TARGET "local-fs.target"
+#define SPECIAL_LOCAL_FS_PRE_TARGET "local-fs-pre.target"
+#define SPECIAL_INITRD_FS_TARGET "initrd-fs.target"
+#define SPECIAL_INITRD_ROOT_DEVICE_TARGET "initrd-root-device.target"
+#define SPECIAL_INITRD_ROOT_FS_TARGET "initrd-root-fs.target"
+#define SPECIAL_REMOTE_FS_TARGET "remote-fs.target"       /* LSB's $remote_fs */
+#define SPECIAL_REMOTE_FS_PRE_TARGET "remote-fs-pre.target"
+#define SPECIAL_SWAP_TARGET "swap.target"
+#define SPECIAL_NETWORK_ONLINE_TARGET "network-online.target"
+#define SPECIAL_TIME_SYNC_TARGET "time-sync.target"       /* LSB's $time */
+#define SPECIAL_BASIC_TARGET "basic.target"
+
+/* LSB compatibility */
+#define SPECIAL_NETWORK_TARGET "network.target"           /* LSB's $network */
+#define SPECIAL_NSS_LOOKUP_TARGET "nss-lookup.target"     /* LSB's $named */
+#define SPECIAL_RPCBIND_TARGET "rpcbind.target"           /* LSB's $portmap */
+
+/*
+ * Rules regarding adding further high level targets like the above:
+ *
+ * - Be conservative, only add more of these when we really need
+ *   them. We need strong usecases for further additions.
+ *
+ * - When there can be multiple implementations running side-by-side,
+ *   it needs to be a .target unit which can pull in all
+ *   implementations.
+ *
+ * - If something can be implemented with socket activation, and
+ *   without, it needs to be a .target unit, so that it can pull in
+ *   the appropriate unit.
+ *
+ * - Otherwise, it should be a .service unit.
+ *
+ * - In some cases it is OK to have both a .service and a .target
+ *   unit, i.e. if there can be multiple parallel implementations, but
+ *   only one is the "system" one. Example: syslog.
+ *
+ * Or to put this in other words: .service symlinks can be used to
+ * arbitrate between multiple implementations if there can be only one
+ * of a kind. .target units can be used to support multiple
+ * implementations that can run side-by-side.
+ */
+
+/* Magic early boot services */
+#define SPECIAL_FSCK_SERVICE "systemd-fsck@.service"
+#define SPECIAL_QUOTACHECK_SERVICE "systemd-quotacheck.service"
+#define SPECIAL_QUOTAON_SERVICE "quotaon.service"
+#define SPECIAL_REMOUNT_FS_SERVICE "systemd-remount-fs.service"
+
+/* Services systemd relies on */
+#define SPECIAL_DBUS_SERVICE "dbus.service"
+#define SPECIAL_DBUS_SOCKET "dbus.socket"
+#define SPECIAL_JOURNALD_SOCKET "systemd-journald.socket"
+#define SPECIAL_JOURNALD_SERVICE "systemd-journald.service"
+#define SPECIAL_TMPFILES_SETUP_SERVICE "systemd-tmpfiles-setup.service"
+
+/* Magic init signals */
+#define SPECIAL_KBREQUEST_TARGET "kbrequest.target"
+#define SPECIAL_SIGPWR_TARGET "sigpwr.target"
+#define SPECIAL_CTRL_ALT_DEL_TARGET "ctrl-alt-del.target"
+
+/* Where we add all our system units, users and machines by default */
+#define SPECIAL_SYSTEM_SLICE "system.slice"
+#define SPECIAL_USER_SLICE "user.slice"
+#define SPECIAL_MACHINE_SLICE "machine.slice"
+#define SPECIAL_ROOT_SLICE "-.slice"
+
+/* The scope unit systemd itself lives in. */
+#define SPECIAL_INIT_SCOPE "init.scope"
+
+/* The root directory. */
+#define SPECIAL_ROOT_MOUNT "-.mount"
diff --git a/src/basic/stat-util.c b/src/basic/stat-util.c
new file mode 100644
index 0000000..ea2bbc3
--- /dev/null
+++ b/src/basic/stat-util.c
@@ -0,0 +1,427 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/magic.h>
+#include <sched.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+
+int is_symlink(const char *path) {
+        struct stat info;
+
+        assert(path);
+
+        if (lstat(path, &info) < 0)
+                return -errno;
+
+        return !!S_ISLNK(info.st_mode);
+}
+
+int is_dir(const char* path, bool follow) {
+        struct stat st;
+        int r;
+
+        assert(path);
+
+        if (follow)
+                r = stat(path, &st);
+        else
+                r = lstat(path, &st);
+        if (r < 0)
+                return -errno;
+
+        return !!S_ISDIR(st.st_mode);
+}
+
+int is_dir_fd(int fd) {
+        struct stat st;
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        return !!S_ISDIR(st.st_mode);
+}
+
+int is_device_node(const char *path) {
+        struct stat info;
+
+        assert(path);
+
+        if (lstat(path, &info) < 0)
+                return -errno;
+
+        return !!(S_ISBLK(info.st_mode) || S_ISCHR(info.st_mode));
+}
+
+int dir_is_empty_at(int dir_fd, const char *path) {
+        _cleanup_close_ int fd = -1;
+        _cleanup_closedir_ DIR *d = NULL;
+        struct dirent *de;
+
+        if (path)
+                fd = openat(dir_fd, path, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
+        else
+                fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
+        if (fd < 0)
+                return -errno;
+
+        d = fdopendir(fd);
+        if (!d)
+                return -errno;
+        fd = -1;
+
+        FOREACH_DIRENT(de, d, return -errno)
+                return 0;
+
+        return 1;
+}
+
+bool null_or_empty(struct stat *st) {
+        assert(st);
+
+        if (S_ISREG(st->st_mode) && st->st_size <= 0)
+                return true;
+
+        /* We don't want to hardcode the major/minor of /dev/null,
+         * hence we do a simpler "is this a device node?" check. */
+
+        if (S_ISCHR(st->st_mode) || S_ISBLK(st->st_mode))
+                return true;
+
+        return false;
+}
+
+int null_or_empty_path(const char *fn) {
+        struct stat st;
+
+        assert(fn);
+
+        if (stat(fn, &st) < 0)
+                return -errno;
+
+        return null_or_empty(&st);
+}
+
+int null_or_empty_fd(int fd) {
+        struct stat st;
+
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        return null_or_empty(&st);
+}
+
+int path_is_read_only_fs(const char *path) {
+        struct statvfs st;
+
+        assert(path);
+
+        if (statvfs(path, &st) < 0)
+                return -errno;
+
+        if (st.f_flag & ST_RDONLY)
+                return true;
+
+        /* On NFS, statvfs() might not reflect whether we can actually
+         * write to the remote share. Let's try again with
+         * access(W_OK) which is more reliable, at least sometimes. */
+        if (access(path, W_OK) < 0 && errno == EROFS)
+                return true;
+
+        return false;
+}
+
+int files_same(const char *filea, const char *fileb, int flags) {
+        struct stat a, b;
+
+        assert(filea);
+        assert(fileb);
+
+        if (fstatat(AT_FDCWD, filea, &a, flags) < 0)
+                return -errno;
+
+        if (fstatat(AT_FDCWD, fileb, &b, flags) < 0)
+                return -errno;
+
+        return a.st_dev == b.st_dev &&
+               a.st_ino == b.st_ino;
+}
+
+bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {
+        assert(s);
+        assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));
+
+        return F_TYPE_EQUAL(s->f_type, magic_value);
+}
+
+int fd_is_fs_type(int fd, statfs_f_type_t magic_value) {
+        struct statfs s;
+
+        if (fstatfs(fd, &s) < 0)
+                return -errno;
+
+        return is_fs_type(&s, magic_value);
+}
+
+int path_is_fs_type(const char *path, statfs_f_type_t magic_value) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_PATH);
+        if (fd < 0)
+                return -errno;
+
+        return fd_is_fs_type(fd, magic_value);
+}
+
+bool is_temporary_fs(const struct statfs *s) {
+        return is_fs_type(s, TMPFS_MAGIC) ||
+                is_fs_type(s, RAMFS_MAGIC);
+}
+
+bool is_network_fs(const struct statfs *s) {
+        return is_fs_type(s, CIFS_MAGIC_NUMBER) ||
+                is_fs_type(s, CODA_SUPER_MAGIC) ||
+                is_fs_type(s, NCP_SUPER_MAGIC) ||
+                is_fs_type(s, NFS_SUPER_MAGIC) ||
+                is_fs_type(s, SMB_SUPER_MAGIC) ||
+                is_fs_type(s, V9FS_MAGIC) ||
+                is_fs_type(s, AFS_SUPER_MAGIC) ||
+                is_fs_type(s, OCFS2_SUPER_MAGIC);
+}
+
+int fd_is_temporary_fs(int fd) {
+        struct statfs s;
+
+        if (fstatfs(fd, &s) < 0)
+                return -errno;
+
+        return is_temporary_fs(&s);
+}
+
+int fd_is_network_fs(int fd) {
+        struct statfs s;
+
+        if (fstatfs(fd, &s) < 0)
+                return -errno;
+
+        return is_network_fs(&s);
+}
+
+int fd_is_network_ns(int fd) {
+        struct statfs s;
+        int r;
+
+        /* Checks whether the specified file descriptor refers to a network namespace. On old kernels there's no nice
+         * way to detect that, hence on those we'll return a recognizable error (EUCLEAN), so that callers can handle
+         * this somewhat nicely.
+         *
+         * This function returns > 0 if the fd definitely refers to a network namespace, 0 if it definitely does not
+         * refer to a network namespace, -EUCLEAN if we can't determine, and other negative error codes on error. */
+
+        if (fstatfs(fd, &s) < 0)
+                return -errno;
+
+        if (!is_fs_type(&s, NSFS_MAGIC)) {
+                /* On really old kernels, there was no "nsfs", and network namespace sockets belonged to procfs
+                 * instead. Handle that in a somewhat smart way. */
+
+                if (is_fs_type(&s, PROC_SUPER_MAGIC)) {
+                        struct statfs t;
+
+                        /* OK, so it is procfs. Let's see if our own network namespace is procfs, too. If so, then the
+                         * passed fd might refer to a network namespace, but we can't know for sure. In that case,
+                         * return a recognizable error. */
+
+                        if (statfs("/proc/self/ns/net", &t) < 0)
+                                return -errno;
+
+                        if (s.f_type == t.f_type)
+                                return -EUCLEAN; /* It's possible, we simply don't know */
+                }
+
+                return 0; /* No! */
+        }
+
+        r = ioctl(fd, NS_GET_NSTYPE);
+        if (r < 0) {
+                if (errno == ENOTTY) /* Old kernels didn't know this ioctl, let's also return a recognizable error in that case */
+                        return -EUCLEAN;
+
+                return -errno;
+        }
+
+        return r == CLONE_NEWNET;
+}
+
+int path_is_temporary_fs(const char *path) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_PATH);
+        if (fd < 0)
+                return -errno;
+
+        return fd_is_temporary_fs(fd);
+}
+
+int stat_verify_regular(const struct stat *st) {
+        assert(st);
+
+        /* Checks whether the specified stat() structure refers to a regular file. If not returns an appropriate error
+         * code. */
+
+        if (S_ISDIR(st->st_mode))
+                return -EISDIR;
+
+        if (S_ISLNK(st->st_mode))
+                return -ELOOP;
+
+        if (!S_ISREG(st->st_mode))
+                return -EBADFD;
+
+        return 0;
+}
+
+int fd_verify_regular(int fd) {
+        struct stat st;
+
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        return stat_verify_regular(&st);
+}
+
+int stat_verify_directory(const struct stat *st) {
+        assert(st);
+
+        if (S_ISLNK(st->st_mode))
+                return -ELOOP;
+
+        if (!S_ISDIR(st->st_mode))
+                return -ENOTDIR;
+
+        return 0;
+}
+
+int fd_verify_directory(int fd) {
+        struct stat st;
+
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        return stat_verify_directory(&st);
+}
+
+int device_path_make_major_minor(mode_t mode, dev_t devno, char **ret) {
+        const char *t;
+
+        /* Generates the /dev/{char|block}/MAJOR:MINOR path for a dev_t */
+
+        if (S_ISCHR(mode))
+                t = "char";
+        else if (S_ISBLK(mode))
+                t = "block";
+        else
+                return -ENODEV;
+
+        if (asprintf(ret, "/dev/%s/%u:%u", t, major(devno), minor(devno)) < 0)
+                return -ENOMEM;
+
+        return 0;
+}
+
+int device_path_make_canonical(mode_t mode, dev_t devno, char **ret) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        /* Finds the canonical path for a device, i.e. resolves the /dev/{char|block}/MAJOR:MINOR path to the end. */
+
+        assert(ret);
+
+        if (major(devno) == 0 && minor(devno) == 0) {
+                char *s;
+
+                /* A special hack to make sure our 'inaccessible' device nodes work. They won't have symlinks in
+                 * /dev/block/ and /dev/char/, hence we handle them specially here. */
+
+                if (S_ISCHR(mode))
+                        s = strdup("/run/systemd/inaccessible/chr");
+                else if (S_ISBLK(mode))
+                        s = strdup("/run/systemd/inaccessible/blk");
+                else
+                        return -ENODEV;
+
+                if (!s)
+                        return -ENOMEM;
+
+                *ret = s;
+                return 0;
+        }
+
+        r = device_path_make_major_minor(mode, devno, &p);
+        if (r < 0)
+                return r;
+
+        return chase_symlinks(p, NULL, 0, ret);
+}
+
+int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret_devno) {
+        mode_t mode;
+        dev_t devno;
+        int r;
+
+        /* Tries to extract the major/minor directly from the device path if we can. Handles /dev/block/ and /dev/char/
+         * paths, as well out synthetic inaccessible device nodes. Never goes to disk. Returns -ENODEV if the device
+         * path cannot be parsed like this.  */
+
+        if (path_equal(path, "/run/systemd/inaccessible/chr")) {
+                mode = S_IFCHR;
+                devno = makedev(0, 0);
+        } else if (path_equal(path, "/run/systemd/inaccessible/blk")) {
+                mode = S_IFBLK;
+                devno = makedev(0, 0);
+        } else {
+                const char *w;
+
+                w = path_startswith(path, "/dev/block/");
+                if (w)
+                        mode = S_IFBLK;
+                else {
+                        w = path_startswith(path, "/dev/char/");
+                        if (!w)
+                                return -ENODEV;
+
+                        mode = S_IFCHR;
+                }
+
+                r = parse_dev(w, &devno);
+                if (r < 0)
+                        return r;
+        }
+
+        if (ret_mode)
+                *ret_mode = mode;
+        if (ret_devno)
+                *ret_devno = devno;
+
+        return 0;
+}
diff --git a/src/basic/stat-util.h b/src/basic/stat-util.h
new file mode 100644
index 0000000..74fb725
--- /dev/null
+++ b/src/basic/stat-util.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <sys/vfs.h>
+
+#include "macro.h"
+
+int is_symlink(const char *path);
+int is_dir(const char *path, bool follow);
+int is_dir_fd(int fd);
+int is_device_node(const char *path);
+
+int dir_is_empty_at(int dir_fd, const char *path);
+static inline int dir_is_empty(const char *path) {
+        return dir_is_empty_at(AT_FDCWD, path);
+}
+
+static inline int dir_is_populated(const char *path) {
+        int r;
+        r = dir_is_empty(path);
+        if (r < 0)
+                return r;
+        return !r;
+}
+
+bool null_or_empty(struct stat *st) _pure_;
+int null_or_empty_path(const char *fn);
+int null_or_empty_fd(int fd);
+
+int path_is_read_only_fs(const char *path);
+
+int files_same(const char *filea, const char *fileb, int flags);
+
+/* The .f_type field of struct statfs is really weird defined on
+ * different archs. Let's give its type a name. */
+typedef typeof(((struct statfs*)NULL)->f_type) statfs_f_type_t;
+
+bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) _pure_;
+int fd_is_fs_type(int fd, statfs_f_type_t magic_value);
+int path_is_fs_type(const char *path, statfs_f_type_t magic_value);
+
+bool is_temporary_fs(const struct statfs *s) _pure_;
+bool is_network_fs(const struct statfs *s) _pure_;
+
+int fd_is_temporary_fs(int fd);
+int fd_is_network_fs(int fd);
+
+int fd_is_network_ns(int fd);
+
+int path_is_temporary_fs(const char *path);
+
+/* Because statfs.t_type can be int on some architectures, we have to cast
+ * the const magic to the type, otherwise the compiler warns about
+ * signed/unsigned comparison, because the magic can be 32 bit unsigned.
+ */
+#define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
+
+int stat_verify_regular(const struct stat *st);
+int fd_verify_regular(int fd);
+
+int stat_verify_directory(const struct stat *st);
+int fd_verify_directory(int fd);
+
+/* glibc and the Linux kernel have different ideas about the major/minor size. These calls will check whether the
+ * specified major is valid by the Linux kernel's standards, not by glibc's. Linux has 20bits of minor, and 12 bits of
+ * major space. See MINORBITS in linux/kdev_t.h in the kernel sources. (If you wonder why we define _y here, instead of
+ * comparing directly >= 0: it's to trick out -Wtype-limits, which would otherwise complain if the type is unsigned, as
+ * such a test would be pointless in such a case.) */
+
+#define DEVICE_MAJOR_VALID(x)                                           \
+        ({                                                              \
+                typeof(x) _x = (x), _y = 0;                             \
+                _x >= _y && _x < (UINT32_C(1) << 12);                   \
+                                                                        \
+        })
+
+#define DEVICE_MINOR_VALID(x)                                           \
+        ({                                                              \
+                typeof(x) _x = (x), _y = 0;                             \
+                _x >= _y && _x < (UINT32_C(1) << 20);                   \
+        })
+
+int device_path_make_major_minor(mode_t mode, dev_t devno, char **ret);
+int device_path_make_canonical(mode_t mode, dev_t devno, char **ret);
+int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret_devno);
diff --git a/src/basic/static-destruct.h b/src/basic/static-destruct.h
new file mode 100644
index 0000000..443c0e8
--- /dev/null
+++ b/src/basic/static-destruct.h
@@ -0,0 +1,56 @@
+#pragma once
+
+#include "alloc-util.h"
+#include "macro.h"
+
+/* A framework for registering static variables that shall be freed on shutdown of a process. It's a bit like gcc's
+ * destructor attribute, but allows us to precisely schedule when we want to free the variables. This is supposed to
+ * feel a bit like the gcc cleanup attribute, but for static variables. Note that this does not work for static
+ * variables declared in .so's, as the list is private to the same linking unit. But maybe that's a good thing. */
+
+typedef struct StaticDestructor {
+        void *data;
+        free_func_t destroy;
+} StaticDestructor;
+
+#define STATIC_DESTRUCTOR_REGISTER(variable, func) \
+        _STATIC_DESTRUCTOR_REGISTER(UNIQ, variable, func)
+
+#define _STATIC_DESTRUCTOR_REGISTER(uq, variable, func)                 \
+        /* Type-safe destructor */                                      \
+        static void UNIQ_T(static_destructor_wrapper, uq)(void *p) {    \
+                typeof(variable) *q = p;                                \
+                func(q);                                                \
+        }                                                               \
+        /* The actual destructor structure we place in a special section to find it */ \
+        _section_("SYSTEMD_STATIC_DESTRUCT")                            \
+        /* We pick pointer alignment, since that is apparently what gcc does for static variables */ \
+        _alignptr_                                                      \
+        /* Make sure this is not dropped from the image because not explicitly referenced */ \
+        _used_                                                          \
+        /* Make sure that AddressSanitizer doesn't pad this variable: we want everything in this section packed next to each other so that we can enumerate it. */ \
+        _variable_no_sanitize_address_                                  \
+        static const StaticDestructor UNIQ_T(static_destructor_entry, uq) = { \
+                .data = &(variable),                                    \
+                .destroy = UNIQ_T(static_destructor_wrapper, uq),       \
+        }
+
+/* Beginning and end of our section listing the destructors. We define these as weak as we want this to work even if
+ * there's not a single destructor is defined in which case the section will be missing. */
+extern const struct StaticDestructor _weak_ __start_SYSTEMD_STATIC_DESTRUCT[];
+extern const struct StaticDestructor _weak_ __stop_SYSTEMD_STATIC_DESTRUCT[];
+
+/* The function to destroy everything. (Note that this must be static inline, as it's key that it remains in the same
+ * linking unit as the variables we want to destroy. */
+static inline void static_destruct(void) {
+        const StaticDestructor *d;
+
+        if (!__start_SYSTEMD_STATIC_DESTRUCT)
+                return;
+
+        d = ALIGN_TO_PTR(__start_SYSTEMD_STATIC_DESTRUCT, sizeof(void*));
+        while (d < __stop_SYSTEMD_STATIC_DESTRUCT) {
+                d->destroy(d->data);
+                d = ALIGN_TO_PTR(d + 1, sizeof(void*));
+        }
+}
diff --git a/src/basic/stdio-util.h b/src/basic/stdio-util.h
new file mode 100644
index 0000000..dc67b6e
--- /dev/null
+++ b/src/basic/stdio-util.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <printf.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "macro.h"
+#include "util.h"
+
+#define snprintf_ok(buf, len, fmt, ...) \
+        ((size_t) snprintf(buf, len, fmt, __VA_ARGS__) < (len))
+
+#define xsprintf(buf, fmt, ...) \
+        assert_message_se(snprintf_ok(buf, ELEMENTSOF(buf), fmt, __VA_ARGS__), "xsprintf: " #buf "[] must be big enough")
+
+#define VA_FORMAT_ADVANCE(format, ap)                                   \
+do {                                                                    \
+        int _argtypes[128];                                             \
+        size_t _i, _k;                                                  \
+        /* See https://github.com/google/sanitizers/issues/992 */       \
+        if (HAS_FEATURE_MEMORY_SANITIZER)                               \
+                zero(_argtypes);                                        \
+        _k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
+        assert(_k < ELEMENTSOF(_argtypes));                             \
+        for (_i = 0; _i < _k; _i++) {                                   \
+                if (_argtypes[_i] & PA_FLAG_PTR)  {                     \
+                        (void) va_arg(ap, void*);                       \
+                        continue;                                       \
+                }                                                       \
+                                                                        \
+                switch (_argtypes[_i]) {                                \
+                case PA_INT:                                            \
+                case PA_INT|PA_FLAG_SHORT:                              \
+                case PA_CHAR:                                           \
+                        (void) va_arg(ap, int);                         \
+                        break;                                          \
+                case PA_INT|PA_FLAG_LONG:                               \
+                        (void) va_arg(ap, long int);                    \
+                        break;                                          \
+                case PA_INT|PA_FLAG_LONG_LONG:                          \
+                        (void) va_arg(ap, long long int);               \
+                        break;                                          \
+                case PA_WCHAR:                                          \
+                        (void) va_arg(ap, wchar_t);                     \
+                        break;                                          \
+                case PA_WSTRING:                                        \
+                case PA_STRING:                                         \
+                case PA_POINTER:                                        \
+                        (void) va_arg(ap, void*);                       \
+                        break;                                          \
+                case PA_FLOAT:                                          \
+                case PA_DOUBLE:                                         \
+                        (void) va_arg(ap, double);                      \
+                        break;                                          \
+                case PA_DOUBLE|PA_FLAG_LONG_DOUBLE:                     \
+                        (void) va_arg(ap, long double);                 \
+                        break;                                          \
+                default:                                                \
+                        assert_not_reached("Unknown format string argument."); \
+                }                                                       \
+        }                                                               \
+} while (false)
diff --git a/src/basic/strbuf.c b/src/basic/strbuf.c
new file mode 100644
index 0000000..81f4f21
--- /dev/null
+++ b/src/basic/strbuf.c
@@ -0,0 +1,183 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "strbuf.h"
+#include "util.h"
+
+/*
+ * Strbuf stores given strings in a single continuous allocated memory
+ * area. Identical strings are de-duplicated and return the same offset
+ * as the first string stored. If the tail of a string already exists
+ * in the buffer, the tail is returned.
+ *
+ * A trie (http://en.wikipedia.org/wiki/Trie) is used to maintain the
+ * information about the stored strings.
+ *
+ * Example of udev rules:
+ *   $ ./udevadm test .
+ *   ...
+ *   read rules file: /usr/lib/udev/rules.d/99-systemd.rules
+ *   rules contain 196608 bytes tokens (16384 * 12 bytes), 39742 bytes strings
+ *   23939 strings (207859 bytes), 20404 de-duplicated (171653 bytes), 3536 trie nodes used
+ *   ...
+ */
+
+struct strbuf *strbuf_new(void) {
+        struct strbuf *str;
+
+        str = new(struct strbuf, 1);
+        if (!str)
+                return NULL;
+        *str = (struct strbuf) {
+                .buf = new0(char, 1),
+                .root = new0(struct strbuf_node, 1),
+                .len = 1,
+                .nodes_count = 1,
+        };
+        if (!str->buf || !str->root) {
+                free(str->buf);
+                free(str->root);
+                return mfree(str);
+        }
+
+        return str;
+}
+
+static struct strbuf_node* strbuf_node_cleanup(struct strbuf_node *node) {
+        size_t i;
+
+        for (i = 0; i < node->children_count; i++)
+                strbuf_node_cleanup(node->children[i].child);
+        free(node->children);
+        return mfree(node);
+}
+
+/* clean up trie data, leave only the string buffer */
+void strbuf_complete(struct strbuf *str) {
+        if (!str)
+                return;
+        if (str->root)
+                str->root = strbuf_node_cleanup(str->root);
+}
+
+/* clean up everything */
+void strbuf_cleanup(struct strbuf *str) {
+        if (!str)
+                return;
+
+        strbuf_complete(str);
+        free(str->buf);
+        free(str);
+}
+
+static int strbuf_children_cmp(const struct strbuf_child_entry *n1,
+                               const struct strbuf_child_entry *n2) {
+        return n1->c - n2->c;
+}
+
+static void bubbleinsert(struct strbuf_node *node,
+                         uint8_t c,
+                         struct strbuf_node *node_child) {
+
+        struct strbuf_child_entry new = {
+                .c = c,
+                .child = node_child,
+        };
+        int left = 0, right = node->children_count;
+
+        while (right > left) {
+                int middle = (right + left) / 2 ;
+                if (strbuf_children_cmp(&node->children[middle], &new) <= 0)
+                        left = middle + 1;
+                else
+                        right = middle;
+        }
+
+        memmove(node->children + left + 1, node->children + left,
+                sizeof(struct strbuf_child_entry) * (node->children_count - left));
+        node->children[left] = new;
+
+        node->children_count++;
+}
+
+/* add string, return the index/offset into the buffer */
+ssize_t strbuf_add_string(struct strbuf *str, const char *s, size_t len) {
+        uint8_t c;
+        struct strbuf_node *node;
+        size_t depth;
+        char *buf_new;
+        struct strbuf_child_entry *child;
+        struct strbuf_node *node_child;
+        ssize_t off;
+
+        if (!str->root)
+                return -EINVAL;
+
+        /* search string; start from last character to find possibly matching tails */
+
+        str->in_count++;
+        if (len == 0) {
+                str->dedup_count++;
+                return 0;
+        }
+        str->in_len += len;
+
+        node = str->root;
+        for (depth = 0; depth <= len; depth++) {
+                struct strbuf_child_entry search;
+
+                /* match against current node */
+                off = node->value_off + node->value_len - len;
+                if (depth == len || (node->value_len >= len && memcmp(str->buf + off, s, len) == 0)) {
+                        str->dedup_len += len;
+                        str->dedup_count++;
+                        return off;
+                }
+
+                c = s[len - 1 - depth];
+
+                /* lookup child node */
+                search.c = c;
+                child = typesafe_bsearch(&search, node->children, node->children_count, strbuf_children_cmp);
+                if (!child)
+                        break;
+                node = child->child;
+        }
+
+        /* add new string */
+        buf_new = realloc(str->buf, str->len + len+1);
+        if (!buf_new)
+                return -ENOMEM;
+        str->buf = buf_new;
+        off = str->len;
+        memcpy(str->buf + off, s, len);
+        str->len += len;
+        str->buf[str->len++] = '\0';
+
+        /* new node */
+        node_child = new(struct strbuf_node, 1);
+        if (!node_child)
+                return -ENOMEM;
+        *node_child = (struct strbuf_node) {
+                .value_off = off,
+                .value_len = len,
+        };
+
+        /* extend array, add new entry, sort for bisection */
+        child = reallocarray(node->children, node->children_count + 1, sizeof(struct strbuf_child_entry));
+        if (!child) {
+                free(node_child);
+                return -ENOMEM;
+        }
+
+        str->nodes_count++;
+
+        node->children = child;
+        bubbleinsert(node, c, node_child);
+
+        return off;
+}
diff --git a/src/basic/strbuf.h b/src/basic/strbuf.h
new file mode 100644
index 0000000..a36944a
--- /dev/null
+++ b/src/basic/strbuf.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "macro.h"
+
+struct strbuf {
+        char *buf;
+        size_t len;
+        struct strbuf_node *root;
+
+        size_t nodes_count;
+        size_t in_count;
+        size_t in_len;
+        size_t dedup_len;
+        size_t dedup_count;
+};
+
+struct strbuf_node {
+        size_t value_off;
+        size_t value_len;
+
+        struct strbuf_child_entry *children;
+        uint8_t children_count;
+};
+
+struct strbuf_child_entry {
+        uint8_t c;
+        struct strbuf_node *child;
+};
+
+struct strbuf *strbuf_new(void);
+ssize_t strbuf_add_string(struct strbuf *str, const char *s, size_t len);
+void strbuf_complete(struct strbuf *str);
+void strbuf_cleanup(struct strbuf *str);
+DEFINE_TRIVIAL_CLEANUP_FUNC(struct strbuf*, strbuf_cleanup);
diff --git a/src/basic/string-table.c b/src/basic/string-table.c
new file mode 100644
index 0000000..34931b0
--- /dev/null
+++ b/src/basic/string-table.c
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "string-table.h"
+#include "string-util.h"
+
+ssize_t string_table_lookup(const char * const *table, size_t len, const char *key) {
+        size_t i;
+
+        if (!key)
+                return -1;
+
+        for (i = 0; i < len; ++i)
+                if (streq_ptr(table[i], key))
+                        return (ssize_t) i;
+
+        return -1;
+}
diff --git a/src/basic/string-table.h b/src/basic/string-table.h
new file mode 100644
index 0000000..228c12a
--- /dev/null
+++ b/src/basic/string-table.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#pragma once
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "macro.h"
+#include "parse-util.h"
+#include "string-util.h"
+
+ssize_t string_table_lookup(const char * const *table, size_t len, const char *key);
+
+/* For basic lookup tables with strictly enumerated entries */
+#define _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope)          \
+        scope const char *name##_to_string(type i) {                    \
+                if (i < 0 || i >= (type) ELEMENTSOF(name##_table))      \
+                        return NULL;                                    \
+                return name##_table[i];                                 \
+        }
+
+#define _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,scope)        \
+        scope type name##_from_string(const char *s) {                  \
+                return (type) string_table_lookup(name##_table, ELEMENTSOF(name##_table), s); \
+        }
+
+#define _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(name,type,yes,scope) \
+        scope type name##_from_string(const char *s) {                  \
+                int b;                                                  \
+                if (!s)                                                 \
+                        return -1;                                      \
+                b = parse_boolean(s);                                   \
+                if (b == 0)                                             \
+                        return (type) 0;                                \
+                else if (b > 0)                                         \
+                        return yes;                                     \
+                return (type) string_table_lookup(name##_table, ELEMENTSOF(name##_table), s); \
+        }
+
+#define _DEFINE_STRING_TABLE_LOOKUP_TO_STRING_FALLBACK(name,type,max,scope) \
+        scope int name##_to_string_alloc(type i, char **str) {          \
+                char *s;                                                \
+                if (i < 0 || i > max)                                   \
+                        return -ERANGE;                                 \
+                if (i < (type) ELEMENTSOF(name##_table)) {              \
+                        s = strdup(name##_table[i]);                    \
+                        if (!s)                                         \
+                                return -ENOMEM;                         \
+                } else {                                                \
+                        if (asprintf(&s, "%i", i) < 0)                  \
+                                return -ENOMEM;                         \
+                }                                                       \
+                *str = s;                                               \
+                return 0;                                               \
+        }
+
+#define _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_FALLBACK(name,type,max,scope) \
+        scope type name##_from_string(const char *s) {                  \
+                type i;                                                 \
+                unsigned u = 0;                                         \
+                if (!s)                                                 \
+                        return (type) -1;                               \
+                for (i = 0; i < (type) ELEMENTSOF(name##_table); i++)   \
+                        if (streq_ptr(name##_table[i], s))              \
+                                return i;                               \
+                if (safe_atou(s, &u) >= 0 && u <= max)                  \
+                        return (type) u;                                \
+                return (type) -1;                                       \
+        }                                                               \
+
+#define _DEFINE_STRING_TABLE_LOOKUP(name,type,scope)                    \
+        _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope)          \
+        _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,scope)
+
+#define _DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(name,type,yes,scope)   \
+        _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,scope)          \
+        _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(name,type,yes,scope)
+
+#define DEFINE_STRING_TABLE_LOOKUP(name,type) _DEFINE_STRING_TABLE_LOOKUP(name,type,)
+#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP(name,type) _DEFINE_STRING_TABLE_LOOKUP(name,type,static)
+#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(name,type) _DEFINE_STRING_TABLE_LOOKUP_TO_STRING(name,type,static)
+#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(name,type) _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING(name,type,static)
+
+#define DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(name,type,yes) _DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(name,type,yes,)
+
+/* For string conversions where numbers are also acceptable */
+#define DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(name,type,max)         \
+        _DEFINE_STRING_TABLE_LOOKUP_TO_STRING_FALLBACK(name,type,max,)  \
+        _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_FALLBACK(name,type,max,)
+
+#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING_FALLBACK(name,type,max) \
+        _DEFINE_STRING_TABLE_LOOKUP_TO_STRING_FALLBACK(name,type,max,static)
+#define DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING_FALLBACK(name,type,max) \
+        _DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_FALLBACK(name,type,max,static)
+
+#define DUMP_STRING_TABLE(name,type,max)                                \
+        do {                                                            \
+                type _k;                                                \
+                flockfile(stdout);                                      \
+                for (_k = 0; _k < (max); _k++) {                        \
+                        const char *_t;                                 \
+                        _t = name##_to_string(_k);                      \
+                        if (!_t)                                        \
+                                continue;                               \
+                        fputs_unlocked(_t, stdout);                     \
+                        fputc_unlocked('\n', stdout);                   \
+                }                                                       \
+                funlockfile(stdout);                                    \
+        } while(false)
diff --git a/src/basic/string-util.c b/src/basic/string-util.c
new file mode 100644
index 0000000..93917bc
--- /dev/null
+++ b/src/basic/string-util.c
@@ -0,0 +1,1099 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "escape.h"
+#include "gunicode.h"
+#include "locale-util.h"
+#include "macro.h"
+#include "string-util.h"
+#include "terminal-util.h"
+#include "utf8.h"
+#include "util.h"
+#include "fileio.h"
+
+int strcmp_ptr(const char *a, const char *b) {
+
+        /* Like strcmp(), but tries to make sense of NULL pointers */
+        if (a && b)
+                return strcmp(a, b);
+
+        if (!a && b)
+                return -1;
+
+        if (a && !b)
+                return 1;
+
+        return 0;
+}
+
+char* endswith(const char *s, const char *postfix) {
+        size_t sl, pl;
+
+        assert(s);
+        assert(postfix);
+
+        sl = strlen(s);
+        pl = strlen(postfix);
+
+        if (pl == 0)
+                return (char*) s + sl;
+
+        if (sl < pl)
+                return NULL;
+
+        if (memcmp(s + sl - pl, postfix, pl) != 0)
+                return NULL;
+
+        return (char*) s + sl - pl;
+}
+
+char* endswith_no_case(const char *s, const char *postfix) {
+        size_t sl, pl;
+
+        assert(s);
+        assert(postfix);
+
+        sl = strlen(s);
+        pl = strlen(postfix);
+
+        if (pl == 0)
+                return (char*) s + sl;
+
+        if (sl < pl)
+                return NULL;
+
+        if (strcasecmp(s + sl - pl, postfix) != 0)
+                return NULL;
+
+        return (char*) s + sl - pl;
+}
+
+char* first_word(const char *s, const char *word) {
+        size_t sl, wl;
+        const char *p;
+
+        assert(s);
+        assert(word);
+
+        /* Checks if the string starts with the specified word, either
+         * followed by NUL or by whitespace. Returns a pointer to the
+         * NUL or the first character after the whitespace. */
+
+        sl = strlen(s);
+        wl = strlen(word);
+
+        if (sl < wl)
+                return NULL;
+
+        if (wl == 0)
+                return (char*) s;
+
+        if (memcmp(s, word, wl) != 0)
+                return NULL;
+
+        p = s + wl;
+        if (*p == 0)
+                return (char*) p;
+
+        if (!strchr(WHITESPACE, *p))
+                return NULL;
+
+        p += strspn(p, WHITESPACE);
+        return (char*) p;
+}
+
+static size_t strcspn_escaped(const char *s, const char *reject) {
+        bool escaped = false;
+        int n;
+
+        for (n=0; s[n]; n++) {
+                if (escaped)
+                        escaped = false;
+                else if (s[n] == '\\')
+                        escaped = true;
+                else if (strchr(reject, s[n]))
+                        break;
+        }
+
+        /* if s ends in \, return index of previous char */
+        return n - escaped;
+}
+
+/* Split a string into words. */
+const char* split(const char **state, size_t *l, const char *separator, SplitFlags flags) {
+        const char *current;
+
+        current = *state;
+
+        if (!*current) {
+                assert(**state == '\0');
+                return NULL;
+        }
+
+        current += strspn(current, separator);
+        if (!*current) {
+                *state = current;
+                return NULL;
+        }
+
+        if (flags & SPLIT_QUOTES && strchr("\'\"", *current)) {
+                char quotechars[2] = {*current, '\0'};
+
+                *l = strcspn_escaped(current + 1, quotechars);
+                if (current[*l + 1] == '\0' || current[*l + 1] != quotechars[0] ||
+                    (current[*l + 2] && !strchr(separator, current[*l + 2]))) {
+                        /* right quote missing or garbage at the end */
+                        if (flags & SPLIT_RELAX) {
+                                *state = current + *l + 1 + (current[*l + 1] != '\0');
+                                return current + 1;
+                        }
+                        *state = current;
+                        return NULL;
+                }
+                *state = current++ + *l + 2;
+        } else if (flags & SPLIT_QUOTES) {
+                *l = strcspn_escaped(current, separator);
+                if (current[*l] && !strchr(separator, current[*l]) && !(flags & SPLIT_RELAX)) {
+                        /* unfinished escape */
+                        *state = current;
+                        return NULL;
+                }
+                *state = current + *l;
+        } else {
+                *l = strcspn(current, separator);
+                *state = current + *l;
+        }
+
+        return current;
+}
+
+char *strnappend(const char *s, const char *suffix, size_t b) {
+        size_t a;
+        char *r;
+
+        if (!s && !suffix)
+                return strdup("");
+
+        if (!s)
+                return strndup(suffix, b);
+
+        if (!suffix)
+                return strdup(s);
+
+        assert(s);
+        assert(suffix);
+
+        a = strlen(s);
+        if (b > ((size_t) -1) - a)
+                return NULL;
+
+        r = new(char, a+b+1);
+        if (!r)
+                return NULL;
+
+        memcpy(r, s, a);
+        memcpy(r+a, suffix, b);
+        r[a+b] = 0;
+
+        return r;
+}
+
+char *strappend(const char *s, const char *suffix) {
+        return strnappend(s, suffix, strlen_ptr(suffix));
+}
+
+char *strjoin_real(const char *x, ...) {
+        va_list ap;
+        size_t l;
+        char *r, *p;
+
+        va_start(ap, x);
+
+        if (x) {
+                l = strlen(x);
+
+                for (;;) {
+                        const char *t;
+                        size_t n;
+
+                        t = va_arg(ap, const char *);
+                        if (!t)
+                                break;
+
+                        n = strlen(t);
+                        if (n > ((size_t) -1) - l) {
+                                va_end(ap);
+                                return NULL;
+                        }
+
+                        l += n;
+                }
+        } else
+                l = 0;
+
+        va_end(ap);
+
+        r = new(char, l+1);
+        if (!r)
+                return NULL;
+
+        if (x) {
+                p = stpcpy(r, x);
+
+                va_start(ap, x);
+
+                for (;;) {
+                        const char *t;
+
+                        t = va_arg(ap, const char *);
+                        if (!t)
+                                break;
+
+                        p = stpcpy(p, t);
+                }
+
+                va_end(ap);
+        } else
+                r[0] = 0;
+
+        return r;
+}
+
+char *strstrip(char *s) {
+        if (!s)
+                return NULL;
+
+        /* Drops trailing whitespace. Modifies the string in place. Returns pointer to first non-space character */
+
+        return delete_trailing_chars(skip_leading_chars(s, WHITESPACE), WHITESPACE);
+}
+
+char *delete_chars(char *s, const char *bad) {
+        char *f, *t;
+
+        /* Drops all specified bad characters, regardless where in the string */
+
+        if (!s)
+                return NULL;
+
+        if (!bad)
+                bad = WHITESPACE;
+
+        for (f = s, t = s; *f; f++) {
+                if (strchr(bad, *f))
+                        continue;
+
+                *(t++) = *f;
+        }
+
+        *t = 0;
+
+        return s;
+}
+
+char *delete_trailing_chars(char *s, const char *bad) {
+        char *p, *c = s;
+
+        /* Drops all specified bad characters, at the end of the string */
+
+        if (!s)
+                return NULL;
+
+        if (!bad)
+                bad = WHITESPACE;
+
+        for (p = s; *p; p++)
+                if (!strchr(bad, *p))
+                        c = p + 1;
+
+        *c = 0;
+
+        return s;
+}
+
+char *truncate_nl(char *s) {
+        assert(s);
+
+        s[strcspn(s, NEWLINE)] = 0;
+        return s;
+}
+
+char ascii_tolower(char x) {
+
+        if (x >= 'A' && x <= 'Z')
+                return x - 'A' + 'a';
+
+        return x;
+}
+
+char ascii_toupper(char x) {
+
+        if (x >= 'a' && x <= 'z')
+                return x - 'a' + 'A';
+
+        return x;
+}
+
+char *ascii_strlower(char *t) {
+        char *p;
+
+        assert(t);
+
+        for (p = t; *p; p++)
+                *p = ascii_tolower(*p);
+
+        return t;
+}
+
+char *ascii_strupper(char *t) {
+        char *p;
+
+        assert(t);
+
+        for (p = t; *p; p++)
+                *p = ascii_toupper(*p);
+
+        return t;
+}
+
+char *ascii_strlower_n(char *t, size_t n) {
+        size_t i;
+
+        if (n <= 0)
+                return t;
+
+        for (i = 0; i < n; i++)
+                t[i] = ascii_tolower(t[i]);
+
+        return t;
+}
+
+int ascii_strcasecmp_n(const char *a, const char *b, size_t n) {
+
+        for (; n > 0; a++, b++, n--) {
+                int x, y;
+
+                x = (int) (uint8_t) ascii_tolower(*a);
+                y = (int) (uint8_t) ascii_tolower(*b);
+
+                if (x != y)
+                        return x - y;
+        }
+
+        return 0;
+}
+
+int ascii_strcasecmp_nn(const char *a, size_t n, const char *b, size_t m) {
+        int r;
+
+        r = ascii_strcasecmp_n(a, b, MIN(n, m));
+        if (r != 0)
+                return r;
+
+        return CMP(n, m);
+}
+
+bool chars_intersect(const char *a, const char *b) {
+        const char *p;
+
+        /* Returns true if any of the chars in a are in b. */
+        for (p = a; *p; p++)
+                if (strchr(b, *p))
+                        return true;
+
+        return false;
+}
+
+bool string_has_cc(const char *p, const char *ok) {
+        const char *t;
+
+        assert(p);
+
+        /*
+         * Check if a string contains control characters. If 'ok' is
+         * non-NULL it may be a string containing additional CCs to be
+         * considered OK.
+         */
+
+        for (t = p; *t; t++) {
+                if (ok && strchr(ok, *t))
+                        continue;
+
+                if (*t > 0 && *t < ' ')
+                        return true;
+
+                if (*t == 127)
+                        return true;
+        }
+
+        return false;
+}
+
+static int write_ellipsis(char *buf, bool unicode) {
+        if (unicode || is_locale_utf8()) {
+                buf[0] = 0xe2; /* tri-dot ellipsis: … */
+                buf[1] = 0x80;
+                buf[2] = 0xa6;
+        } else {
+                buf[0] = '.';
+                buf[1] = '.';
+                buf[2] = '.';
+        }
+
+        return 3;
+}
+
+static char *ascii_ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
+        size_t x, need_space, suffix_len;
+        char *t;
+
+        assert(s);
+        assert(percent <= 100);
+        assert(new_length != (size_t) -1);
+
+        if (old_length <= new_length)
+                return strndup(s, old_length);
+
+        /* Special case short ellipsations */
+        switch (new_length) {
+
+        case 0:
+                return strdup("");
+
+        case 1:
+                if (is_locale_utf8())
+                        return strdup("…");
+                else
+                        return strdup(".");
+
+        case 2:
+                if (!is_locale_utf8())
+                        return strdup("..");
+
+                break;
+
+        default:
+                break;
+        }
+
+        /* Calculate how much space the ellipsis will take up. If we are in UTF-8 mode we only need space for one
+         * character ("…"), otherwise for three characters ("..."). Note that in both cases we need 3 bytes of storage,
+         * either for the UTF-8 encoded character or for three ASCII characters. */
+        need_space = is_locale_utf8() ? 1 : 3;
+
+        t = new(char, new_length+3);
+        if (!t)
+                return NULL;
+
+        assert(new_length >= need_space);
+
+        x = ((new_length - need_space) * percent + 50) / 100;
+        assert(x <= new_length - need_space);
+
+        memcpy(t, s, x);
+        write_ellipsis(t + x, false);
+        suffix_len = new_length - x - need_space;
+        memcpy(t + x + 3, s + old_length - suffix_len, suffix_len);
+        *(t + x + 3 + suffix_len) = '\0';
+
+        return t;
+}
+
+char *ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
+        size_t x, k, len, len2;
+        const char *i, *j;
+        char *e;
+        int r;
+
+        /* Note that 'old_length' refers to bytes in the string, while 'new_length' refers to character cells taken up
+         * on screen. This distinction doesn't matter for ASCII strings, but it does matter for non-ASCII UTF-8
+         * strings.
+         *
+         * Ellipsation is done in a locale-dependent way:
+         * 1. If the string passed in is fully ASCII and the current locale is not UTF-8, three dots are used ("...")
+         * 2. Otherwise, a unicode ellipsis is used ("…")
+         *
+         * In other words: you'll get a unicode ellipsis as soon as either the string contains non-ASCII characters or
+         * the current locale is UTF-8.
+         */
+
+        assert(s);
+        assert(percent <= 100);
+
+        if (new_length == (size_t) -1)
+                return strndup(s, old_length);
+
+        if (new_length == 0)
+                return strdup("");
+
+        /* If no multibyte characters use ascii_ellipsize_mem for speed */
+        if (ascii_is_valid_n(s, old_length))
+                return ascii_ellipsize_mem(s, old_length, new_length, percent);
+
+        x = ((new_length - 1) * percent) / 100;
+        assert(x <= new_length - 1);
+
+        k = 0;
+        for (i = s; i < s + old_length; i = utf8_next_char(i)) {
+                char32_t c;
+                int w;
+
+                r = utf8_encoded_to_unichar(i, &c);
+                if (r < 0)
+                        return NULL;
+
+                w = unichar_iswide(c) ? 2 : 1;
+                if (k + w <= x)
+                        k += w;
+                else
+                        break;
+        }
+
+        for (j = s + old_length; j > i; ) {
+                char32_t c;
+                int w;
+                const char *jj;
+
+                jj = utf8_prev_char(j);
+                r = utf8_encoded_to_unichar(jj, &c);
+                if (r < 0)
+                        return NULL;
+
+                w = unichar_iswide(c) ? 2 : 1;
+                if (k + w <= new_length) {
+                        k += w;
+                        j = jj;
+                } else
+                        break;
+        }
+        assert(i <= j);
+
+        /* we don't actually need to ellipsize */
+        if (i == j)
+                return memdup_suffix0(s, old_length);
+
+        /* make space for ellipsis, if possible */
+        if (j < s + old_length)
+                j = utf8_next_char(j);
+        else if (i > s)
+                i = utf8_prev_char(i);
+
+        len = i - s;
+        len2 = s + old_length - j;
+        e = new(char, len + 3 + len2 + 1);
+        if (!e)
+                return NULL;
+
+        /*
+        printf("old_length=%zu new_length=%zu x=%zu len=%u len2=%u k=%u\n",
+               old_length, new_length, x, len, len2, k);
+        */
+
+        memcpy(e, s, len);
+        write_ellipsis(e + len, true);
+        memcpy(e + len + 3, j, len2);
+        *(e + len + 3 + len2) = '\0';
+
+        return e;
+}
+
+char *cellescape(char *buf, size_t len, const char *s) {
+        /* Escape and ellipsize s into buffer buf of size len. Only non-control ASCII
+         * characters are copied as they are, everything else is escaped. The result
+         * is different then if escaping and ellipsization was performed in two
+         * separate steps, because each sequence is either stored in full or skipped.
+         *
+         * This function should be used for logging about strings which expected to
+         * be plain ASCII in a safe way.
+         *
+         * An ellipsis will be used if s is too long. It was always placed at the
+         * very end.
+         */
+
+        size_t i = 0, last_char_width[4] = {}, k = 0, j;
+
+        assert(len > 0); /* at least a terminating NUL */
+
+        for (;;) {
+                char four[4];
+                int w;
+
+                if (*s == 0) /* terminating NUL detected? then we are done! */
+                        goto done;
+
+                w = cescape_char(*s, four);
+                if (i + w + 1 > len) /* This character doesn't fit into the buffer anymore? In that case let's
+                                      * ellipsize at the previous location */
+                        break;
+
+                /* OK, there was space, let's add this escaped character to the buffer */
+                memcpy(buf + i, four, w);
+                i += w;
+
+                /* And remember its width in the ring buffer */
+                last_char_width[k] = w;
+                k = (k + 1) % 4;
+
+                s++;
+        }
+
+        /* Ellipsation is necessary. This means we might need to truncate the string again to make space for 4
+         * characters ideally, but the buffer is shorter than that in the first place take what we can get */
+        for (j = 0; j < ELEMENTSOF(last_char_width); j++) {
+
+                if (i + 4 <= len) /* nice, we reached our space goal */
+                        break;
+
+                k = k == 0 ? 3 : k - 1;
+                if (last_char_width[k] == 0) /* bummer, we reached the beginning of the strings */
+                        break;
+
+                assert(i >= last_char_width[k]);
+                i -= last_char_width[k];
+        }
+
+        if (i + 4 <= len) /* yay, enough space */
+                i += write_ellipsis(buf + i, false);
+        else if (i + 3 <= len) { /* only space for ".." */
+                buf[i++] = '.';
+                buf[i++] = '.';
+        } else if (i + 2 <= len) /* only space for a single "." */
+                buf[i++] = '.';
+        else
+                assert(i + 1 <= len);
+
+ done:
+        buf[i] = '\0';
+        return buf;
+}
+
+bool nulstr_contains(const char *nulstr, const char *needle) {
+        const char *i;
+
+        if (!nulstr)
+                return false;
+
+        NULSTR_FOREACH(i, nulstr)
+                if (streq(i, needle))
+                        return true;
+
+        return false;
+}
+
+char* strshorten(char *s, size_t l) {
+        assert(s);
+
+        if (strnlen(s, l+1) > l)
+                s[l] = 0;
+
+        return s;
+}
+
+char *strreplace(const char *text, const char *old_string, const char *new_string) {
+        size_t l, old_len, new_len, allocated = 0;
+        char *t, *ret = NULL;
+        const char *f;
+
+        assert(old_string);
+        assert(new_string);
+
+        if (!text)
+                return NULL;
+
+        old_len = strlen(old_string);
+        new_len = strlen(new_string);
+
+        l = strlen(text);
+        if (!GREEDY_REALLOC(ret, allocated, l+1))
+                return NULL;
+
+        f = text;
+        t = ret;
+        while (*f) {
+                size_t d, nl;
+
+                if (!startswith(f, old_string)) {
+                        *(t++) = *(f++);
+                        continue;
+                }
+
+                d = t - ret;
+                nl = l - old_len + new_len;
+
+                if (!GREEDY_REALLOC(ret, allocated, nl + 1))
+                        return mfree(ret);
+
+                l = nl;
+                t = ret + d;
+
+                t = stpcpy(t, new_string);
+                f += old_len;
+        }
+
+        *t = 0;
+        return ret;
+}
+
+static void advance_offsets(ssize_t diff, size_t offsets[static 2], size_t shift[static 2], size_t size) {
+        if (!offsets)
+                return;
+
+        if ((size_t) diff < offsets[0])
+                shift[0] += size;
+        if ((size_t) diff < offsets[1])
+                shift[1] += size;
+}
+
+char *strip_tab_ansi(char **ibuf, size_t *_isz, size_t highlight[2]) {
+        const char *i, *begin = NULL;
+        enum {
+                STATE_OTHER,
+                STATE_ESCAPE,
+                STATE_CSI,
+                STATE_CSO,
+        } state = STATE_OTHER;
+        char *obuf = NULL;
+        size_t osz = 0, isz, shift[2] = {};
+        FILE *f;
+
+        assert(ibuf);
+        assert(*ibuf);
+
+        /* This does three things:
+         *
+         * 1. Replaces TABs by 8 spaces
+         * 2. Strips ANSI color sequences (a subset of CSI), i.e. ESC '[' … 'm' sequences
+         * 3. Strips ANSI operating system sequences (CSO), i.e. ESC ']' … BEL sequences
+         *
+         * Everything else will be left as it is. In particular other ANSI sequences are left as they are, as are any
+         * other special characters. Truncated ANSI sequences are left-as is too. This call is supposed to suppress the
+         * most basic formatting noise, but nothing else.
+         *
+         * Why care for CSO sequences? Well, to undo what terminal_urlify() and friends generate. */
+
+        isz = _isz ? *_isz : strlen(*ibuf);
+
+        f = open_memstream(&obuf, &osz);
+        if (!f)
+                return NULL;
+
+        /* Note we turn off internal locking on f for performance reasons.  It's safe to do so since we created f here
+         * and it doesn't leave our scope. */
+
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        for (i = *ibuf; i < *ibuf + isz + 1; i++) {
+
+                switch (state) {
+
+                case STATE_OTHER:
+                        if (i >= *ibuf + isz) /* EOT */
+                                break;
+                        else if (*i == '\x1B')
+                                state = STATE_ESCAPE;
+                        else if (*i == '\t') {
+                                fputs("        ", f);
+                                advance_offsets(i - *ibuf, highlight, shift, 7);
+                        } else
+                                fputc(*i, f);
+
+                        break;
+
+                case STATE_ESCAPE:
+                        if (i >= *ibuf + isz) { /* EOT */
+                                fputc('\x1B', f);
+                                advance_offsets(i - *ibuf, highlight, shift, 1);
+                                break;
+                        } else if (*i == '[') { /* ANSI CSI */
+                                state = STATE_CSI;
+                                begin = i + 1;
+                        } else if (*i == ']') { /* ANSI CSO */
+                                state = STATE_CSO;
+                                begin = i + 1;
+                        } else {
+                                fputc('\x1B', f);
+                                fputc(*i, f);
+                                advance_offsets(i - *ibuf, highlight, shift, 1);
+                                state = STATE_OTHER;
+                        }
+
+                        break;
+
+                case STATE_CSI:
+
+                        if (i >= *ibuf + isz || /* EOT … */
+                            !strchr("01234567890;m", *i)) { /* … or invalid chars in sequence */
+                                fputc('\x1B', f);
+                                fputc('[', f);
+                                advance_offsets(i - *ibuf, highlight, shift, 2);
+                                state = STATE_OTHER;
+                                i = begin-1;
+                        } else if (*i == 'm')
+                                state = STATE_OTHER;
+
+                        break;
+
+                case STATE_CSO:
+
+                        if (i >= *ibuf + isz || /* EOT … */
+                            (*i != '\a' && (uint8_t) *i < 32U) || (uint8_t) *i > 126U) { /* … or invalid chars in sequence */
+                                fputc('\x1B', f);
+                                fputc(']', f);
+                                advance_offsets(i - *ibuf, highlight, shift, 2);
+                                state = STATE_OTHER;
+                                i = begin-1;
+                        } else if (*i == '\a')
+                                state = STATE_OTHER;
+
+                        break;
+                }
+        }
+
+        if (fflush_and_check(f) < 0) {
+                fclose(f);
+                return mfree(obuf);
+        }
+
+        fclose(f);
+
+        free(*ibuf);
+        *ibuf = obuf;
+
+        if (_isz)
+                *_isz = osz;
+
+        if (highlight) {
+                highlight[0] += shift[0];
+                highlight[1] += shift[1];
+        }
+
+        return obuf;
+}
+
+char *strextend_with_separator(char **x, const char *separator, ...) {
+        bool need_separator;
+        size_t f, l, l_separator;
+        char *r, *p;
+        va_list ap;
+
+        assert(x);
+
+        l = f = strlen_ptr(*x);
+
+        need_separator = !isempty(*x);
+        l_separator = strlen_ptr(separator);
+
+        va_start(ap, separator);
+        for (;;) {
+                const char *t;
+                size_t n;
+
+                t = va_arg(ap, const char *);
+                if (!t)
+                        break;
+
+                n = strlen(t);
+
+                if (need_separator)
+                        n += l_separator;
+
+                if (n > ((size_t) -1) - l) {
+                        va_end(ap);
+                        return NULL;
+                }
+
+                l += n;
+                need_separator = true;
+        }
+        va_end(ap);
+
+        need_separator = !isempty(*x);
+
+        r = realloc(*x, l+1);
+        if (!r)
+                return NULL;
+
+        p = r + f;
+
+        va_start(ap, separator);
+        for (;;) {
+                const char *t;
+
+                t = va_arg(ap, const char *);
+                if (!t)
+                        break;
+
+                if (need_separator && separator)
+                        p = stpcpy(p, separator);
+
+                p = stpcpy(p, t);
+
+                need_separator = true;
+        }
+        va_end(ap);
+
+        assert(p == r + l);
+
+        *p = 0;
+        *x = r;
+
+        return r + l;
+}
+
+char *strrep(const char *s, unsigned n) {
+        size_t l;
+        char *r, *p;
+        unsigned i;
+
+        assert(s);
+
+        l = strlen(s);
+        p = r = malloc(l * n + 1);
+        if (!r)
+                return NULL;
+
+        for (i = 0; i < n; i++)
+                p = stpcpy(p, s);
+
+        *p = 0;
+        return r;
+}
+
+int split_pair(const char *s, const char *sep, char **l, char **r) {
+        char *x, *a, *b;
+
+        assert(s);
+        assert(sep);
+        assert(l);
+        assert(r);
+
+        if (isempty(sep))
+                return -EINVAL;
+
+        x = strstr(s, sep);
+        if (!x)
+                return -EINVAL;
+
+        a = strndup(s, x - s);
+        if (!a)
+                return -ENOMEM;
+
+        b = strdup(x + strlen(sep));
+        if (!b) {
+                free(a);
+                return -ENOMEM;
+        }
+
+        *l = a;
+        *r = b;
+
+        return 0;
+}
+
+int free_and_strdup(char **p, const char *s) {
+        char *t;
+
+        assert(p);
+
+        /* Replaces a string pointer with a strdup()ed new string,
+         * possibly freeing the old one. */
+
+        if (streq_ptr(*p, s))
+                return 0;
+
+        if (s) {
+                t = strdup(s);
+                if (!t)
+                        return -ENOMEM;
+        } else
+                t = NULL;
+
+        free(*p);
+        *p = t;
+
+        return 1;
+}
+
+int free_and_strndup(char **p, const char *s, size_t l) {
+        char *t;
+
+        assert(p);
+        assert(s || l == 0);
+
+        /* Replaces a string pointer with a strndup()ed new string,
+         * freeing the old one. */
+
+        if (!*p && !s)
+                return 0;
+
+        if (*p && s && strneq(*p, s, l) && (l > strlen(*p) || (*p)[l] == '\0'))
+                return 0;
+
+        if (s) {
+                t = strndup(s, l);
+                if (!t)
+                        return -ENOMEM;
+        } else
+                t = NULL;
+
+        free_and_replace(*p, t);
+        return 1;
+}
+
+#if !HAVE_EXPLICIT_BZERO
+/*
+ * Pointer to memset is volatile so that compiler must de-reference
+ * the pointer and can't assume that it points to any function in
+ * particular (such as memset, which it then might further "optimize")
+ * This approach is inspired by openssl's crypto/mem_clr.c.
+ */
+typedef void *(*memset_t)(void *,int,size_t);
+
+static volatile memset_t memset_func = memset;
+
+void* explicit_bzero_safe(void *p, size_t l) {
+        if (l > 0)
+                memset_func(p, '\0', l);
+
+        return p;
+}
+#endif
+
+char* string_erase(char *x) {
+        if (!x)
+                return NULL;
+
+        /* A delicious drop of snake-oil! To be called on memory where
+         * we stored passphrases or so, after we used them. */
+        explicit_bzero_safe(x, strlen(x));
+        return x;
+}
+
+char *string_free_erase(char *s) {
+        return mfree(string_erase(s));
+}
+
+bool string_is_safe(const char *p) {
+        const char *t;
+
+        if (!p)
+                return false;
+
+        for (t = p; *t; t++) {
+                if (*t > 0 && *t < ' ') /* no control characters */
+                        return false;
+
+                if (strchr(QUOTES "\\\x7f", *t))
+                        return false;
+        }
+
+        return true;
+}
diff --git a/src/basic/string-util.h b/src/basic/string-util.h
new file mode 100644
index 0000000..38070ab
--- /dev/null
+++ b/src/basic/string-util.h
@@ -0,0 +1,266 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <alloca.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "macro.h"
+
+/* What is interpreted as whitespace? */
+#define WHITESPACE        " \t\n\r"
+#define NEWLINE           "\n\r"
+#define QUOTES            "\"\'"
+#define COMMENTS          "#;"
+#define GLOB_CHARS        "*?["
+#define DIGITS            "0123456789"
+#define LOWERCASE_LETTERS "abcdefghijklmnopqrstuvwxyz"
+#define UPPERCASE_LETTERS "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+#define LETTERS           LOWERCASE_LETTERS UPPERCASE_LETTERS
+#define ALPHANUMERICAL    LETTERS DIGITS
+#define HEXDIGITS         DIGITS "abcdefABCDEF"
+
+#define streq(a,b) (strcmp((a),(b)) == 0)
+#define strneq(a, b, n) (strncmp((a), (b), (n)) == 0)
+#define strcaseeq(a,b) (strcasecmp((a),(b)) == 0)
+#define strncaseeq(a, b, n) (strncasecmp((a), (b), (n)) == 0)
+
+int strcmp_ptr(const char *a, const char *b) _pure_;
+
+static inline bool streq_ptr(const char *a, const char *b) {
+        return strcmp_ptr(a, b) == 0;
+}
+
+static inline const char* strempty(const char *s) {
+        return s ?: "";
+}
+
+static inline const char* strnull(const char *s) {
+        return s ?: "(null)";
+}
+
+static inline const char *strna(const char *s) {
+        return s ?: "n/a";
+}
+
+static inline bool isempty(const char *p) {
+        return !p || !p[0];
+}
+
+static inline const char *empty_to_null(const char *p) {
+        return isempty(p) ? NULL : p;
+}
+
+static inline const char *empty_to_dash(const char *str) {
+        return isempty(str) ? "-" : str;
+}
+
+static inline char *startswith(const char *s, const char *prefix) {
+        size_t l;
+
+        l = strlen(prefix);
+        if (strncmp(s, prefix, l) == 0)
+                return (char*) s + l;
+
+        return NULL;
+}
+
+static inline char *startswith_no_case(const char *s, const char *prefix) {
+        size_t l;
+
+        l = strlen(prefix);
+        if (strncasecmp(s, prefix, l) == 0)
+                return (char*) s + l;
+
+        return NULL;
+}
+
+char *endswith(const char *s, const char *postfix) _pure_;
+char *endswith_no_case(const char *s, const char *postfix) _pure_;
+
+char *first_word(const char *s, const char *word) _pure_;
+
+typedef enum SplitFlags {
+        SPLIT_QUOTES                     = 0x01 << 0,
+        SPLIT_RELAX                      = 0x01 << 1,
+} SplitFlags;
+
+const char* split(const char **state, size_t *l, const char *separator, SplitFlags flags);
+
+#define FOREACH_WORD(word, length, s, state)                            \
+        _FOREACH_WORD(word, length, s, WHITESPACE, 0, state)
+
+#define FOREACH_WORD_SEPARATOR(word, length, s, separator, state)       \
+        _FOREACH_WORD(word, length, s, separator, 0, state)
+
+#define _FOREACH_WORD(word, length, s, separator, flags, state)         \
+        for ((state) = (s), (word) = split(&(state), &(length), (separator), (flags)); (word); (word) = split(&(state), &(length), (separator), (flags)))
+
+char *strappend(const char *s, const char *suffix);
+char *strnappend(const char *s, const char *suffix, size_t length);
+
+char *strjoin_real(const char *x, ...) _sentinel_;
+#define strjoin(a, ...) strjoin_real((a), __VA_ARGS__, NULL)
+
+#define strjoina(a, ...)                                                \
+        ({                                                              \
+                const char *_appendees_[] = { a, __VA_ARGS__ };         \
+                char *_d_, *_p_;                                        \
+                size_t _len_ = 0;                                          \
+                size_t _i_;                                           \
+                for (_i_ = 0; _i_ < ELEMENTSOF(_appendees_) && _appendees_[_i_]; _i_++) \
+                        _len_ += strlen(_appendees_[_i_]);              \
+                _p_ = _d_ = newa(char, _len_ + 1);                      \
+                for (_i_ = 0; _i_ < ELEMENTSOF(_appendees_) && _appendees_[_i_]; _i_++) \
+                        _p_ = stpcpy(_p_, _appendees_[_i_]);            \
+                *_p_ = 0;                                               \
+                _d_;                                                    \
+        })
+
+char *strstrip(char *s);
+char *delete_chars(char *s, const char *bad);
+char *delete_trailing_chars(char *s, const char *bad);
+char *truncate_nl(char *s);
+
+static inline char *skip_leading_chars(const char *s, const char *bad) {
+
+        if (!s)
+                return NULL;
+
+        if (!bad)
+                bad = WHITESPACE;
+
+        return (char*) s + strspn(s, bad);
+}
+
+char ascii_tolower(char x);
+char *ascii_strlower(char *s);
+char *ascii_strlower_n(char *s, size_t n);
+
+char ascii_toupper(char x);
+char *ascii_strupper(char *s);
+
+int ascii_strcasecmp_n(const char *a, const char *b, size_t n);
+int ascii_strcasecmp_nn(const char *a, size_t n, const char *b, size_t m);
+
+bool chars_intersect(const char *a, const char *b) _pure_;
+
+static inline bool _pure_ in_charset(const char *s, const char* charset) {
+        assert(s);
+        assert(charset);
+        return s[strspn(s, charset)] == '\0';
+}
+
+bool string_has_cc(const char *p, const char *ok) _pure_;
+
+char *ellipsize_mem(const char *s, size_t old_length_bytes, size_t new_length_columns, unsigned percent);
+static inline char *ellipsize(const char *s, size_t length, unsigned percent) {
+        return ellipsize_mem(s, strlen(s), length, percent);
+}
+
+char *cellescape(char *buf, size_t len, const char *s);
+
+/* This limit is arbitrary, enough to give some idea what the string contains */
+#define CELLESCAPE_DEFAULT_LENGTH 64
+
+bool nulstr_contains(const char *nulstr, const char *needle);
+
+char* strshorten(char *s, size_t l);
+
+char *strreplace(const char *text, const char *old_string, const char *new_string);
+
+char *strip_tab_ansi(char **ibuf, size_t *_isz, size_t highlight[2]);
+
+char *strextend_with_separator(char **x, const char *separator, ...) _sentinel_;
+
+#define strextend(x, ...) strextend_with_separator(x, NULL, __VA_ARGS__)
+
+char *strrep(const char *s, unsigned n);
+
+int split_pair(const char *s, const char *sep, char **l, char **r);
+
+int free_and_strdup(char **p, const char *s);
+int free_and_strndup(char **p, const char *s, size_t l);
+
+/* Normal memmem() requires haystack to be nonnull, which is annoying for zero-length buffers */
+static inline void *memmem_safe(const void *haystack, size_t haystacklen, const void *needle, size_t needlelen) {
+
+        if (needlelen <= 0)
+                return (void*) haystack;
+
+        if (haystacklen < needlelen)
+                return NULL;
+
+        assert(haystack);
+        assert(needle);
+
+        return memmem(haystack, haystacklen, needle, needlelen);
+}
+
+#if HAVE_EXPLICIT_BZERO
+static inline void* explicit_bzero_safe(void *p, size_t l) {
+        if (l > 0)
+                explicit_bzero(p, l);
+
+        return p;
+}
+#else
+void *explicit_bzero_safe(void *p, size_t l);
+#endif
+
+char *string_erase(char *x);
+
+char *string_free_erase(char *s);
+DEFINE_TRIVIAL_CLEANUP_FUNC(char *, string_free_erase);
+#define _cleanup_string_free_erase_ _cleanup_(string_free_erasep)
+
+bool string_is_safe(const char *p) _pure_;
+
+static inline size_t strlen_ptr(const char *s) {
+        if (!s)
+                return 0;
+
+        return strlen(s);
+}
+
+/* Like startswith(), but operates on arbitrary memory blocks */
+static inline void *memory_startswith(const void *p, size_t sz, const char *token) {
+        size_t n;
+
+        assert(token);
+
+        n = strlen(token);
+        if (sz < n)
+                return NULL;
+
+        assert(p);
+
+        if (memcmp(p, token, n) != 0)
+                return NULL;
+
+        return (uint8_t*) p + n;
+}
+
+/* Like startswith_no_case(), but operates on arbitrary memory blocks.
+ * It works only for ASCII strings.
+ */
+static inline void *memory_startswith_no_case(const void *p, size_t sz, const char *token) {
+        size_t n, i;
+
+        assert(token);
+
+        n = strlen(token);
+        if (sz < n)
+                return NULL;
+
+        assert(p);
+
+        for (i = 0; i < n; i++) {
+                if (ascii_tolower(((char *)p)[i]) != ascii_tolower(token[i]))
+                        return NULL;
+        }
+
+        return (uint8_t*) p + n;
+}
diff --git a/src/basic/strv.c b/src/basic/strv.c
new file mode 100644
index 0000000..3a62f25
--- /dev/null
+++ b/src/basic/strv.c
@@ -0,0 +1,889 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fnmatch.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "escape.h"
+#include "extract-word.h"
+#include "fileio.h"
+#include "string-util.h"
+#include "strv.h"
+#include "util.h"
+
+char *strv_find(char **l, const char *name) {
+        char **i;
+
+        assert(name);
+
+        STRV_FOREACH(i, l)
+                if (streq(*i, name))
+                        return *i;
+
+        return NULL;
+}
+
+char *strv_find_prefix(char **l, const char *name) {
+        char **i;
+
+        assert(name);
+
+        STRV_FOREACH(i, l)
+                if (startswith(*i, name))
+                        return *i;
+
+        return NULL;
+}
+
+char *strv_find_startswith(char **l, const char *name) {
+        char **i, *e;
+
+        assert(name);
+
+        /* Like strv_find_prefix, but actually returns only the
+         * suffix, not the whole item */
+
+        STRV_FOREACH(i, l) {
+                e = startswith(*i, name);
+                if (e)
+                        return e;
+        }
+
+        return NULL;
+}
+
+void strv_clear(char **l) {
+        char **k;
+
+        if (!l)
+                return;
+
+        for (k = l; *k; k++)
+                free(*k);
+
+        *l = NULL;
+}
+
+char **strv_free(char **l) {
+        strv_clear(l);
+        return mfree(l);
+}
+
+char **strv_free_erase(char **l) {
+        char **i;
+
+        STRV_FOREACH(i, l)
+                string_erase(*i);
+
+        return strv_free(l);
+}
+
+char **strv_copy(char * const *l) {
+        char **r, **k;
+
+        k = r = new(char*, strv_length(l) + 1);
+        if (!r)
+                return NULL;
+
+        if (l)
+                for (; *l; k++, l++) {
+                        *k = strdup(*l);
+                        if (!*k) {
+                                strv_free(r);
+                                return NULL;
+                        }
+                }
+
+        *k = NULL;
+        return r;
+}
+
+size_t strv_length(char * const *l) {
+        size_t n = 0;
+
+        if (!l)
+                return 0;
+
+        for (; *l; l++)
+                n++;
+
+        return n;
+}
+
+char **strv_new_ap(const char *x, va_list ap) {
+        const char *s;
+        _cleanup_strv_free_ char **a = NULL;
+        size_t n = 0, i = 0;
+        va_list aq;
+
+        /* As a special trick we ignore all listed strings that equal
+         * STRV_IGNORE. This is supposed to be used with the
+         * STRV_IFNOTNULL() macro to include possibly NULL strings in
+         * the string list. */
+
+        if (x) {
+                n = x == STRV_IGNORE ? 0 : 1;
+
+                va_copy(aq, ap);
+                while ((s = va_arg(aq, const char*))) {
+                        if (s == STRV_IGNORE)
+                                continue;
+
+                        n++;
+                }
+
+                va_end(aq);
+        }
+
+        a = new(char*, n+1);
+        if (!a)
+                return NULL;
+
+        if (x) {
+                if (x != STRV_IGNORE) {
+                        a[i] = strdup(x);
+                        if (!a[i])
+                                return NULL;
+                        i++;
+                }
+
+                while ((s = va_arg(ap, const char*))) {
+
+                        if (s == STRV_IGNORE)
+                                continue;
+
+                        a[i] = strdup(s);
+                        if (!a[i])
+                                return NULL;
+
+                        i++;
+                }
+        }
+
+        a[i] = NULL;
+
+        return TAKE_PTR(a);
+}
+
+char **strv_new_internal(const char *x, ...) {
+        char **r;
+        va_list ap;
+
+        va_start(ap, x);
+        r = strv_new_ap(x, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int strv_extend_strv(char ***a, char **b, bool filter_duplicates) {
+        char **s, **t;
+        size_t p, q, i = 0, j;
+
+        assert(a);
+
+        if (strv_isempty(b))
+                return 0;
+
+        p = strv_length(*a);
+        q = strv_length(b);
+
+        t = reallocarray(*a, p + q + 1, sizeof(char *));
+        if (!t)
+                return -ENOMEM;
+
+        t[p] = NULL;
+        *a = t;
+
+        STRV_FOREACH(s, b) {
+
+                if (filter_duplicates && strv_contains(t, *s))
+                        continue;
+
+                t[p+i] = strdup(*s);
+                if (!t[p+i])
+                        goto rollback;
+
+                i++;
+                t[p+i] = NULL;
+        }
+
+        assert(i <= q);
+
+        return (int) i;
+
+rollback:
+        for (j = 0; j < i; j++)
+                free(t[p + j]);
+
+        t[p] = NULL;
+        return -ENOMEM;
+}
+
+int strv_extend_strv_concat(char ***a, char **b, const char *suffix) {
+        int r;
+        char **s;
+
+        STRV_FOREACH(s, b) {
+                char *v;
+
+                v = strappend(*s, suffix);
+                if (!v)
+                        return -ENOMEM;
+
+                r = strv_push(a, v);
+                if (r < 0) {
+                        free(v);
+                        return r;
+                }
+        }
+
+        return 0;
+}
+
+char **strv_split_full(const char *s, const char *separator, SplitFlags flags) {
+        const char *word, *state;
+        size_t l;
+        size_t n, i;
+        char **r;
+
+        assert(s);
+
+        if (!separator)
+                separator = WHITESPACE;
+
+        s += strspn(s, separator);
+        if (isempty(s))
+                return new0(char*, 1);
+
+        n = 0;
+        _FOREACH_WORD(word, l, s, separator, flags, state)
+                n++;
+
+        r = new(char*, n+1);
+        if (!r)
+                return NULL;
+
+        i = 0;
+        _FOREACH_WORD(word, l, s, separator, flags, state) {
+                r[i] = strndup(word, l);
+                if (!r[i]) {
+                        strv_free(r);
+                        return NULL;
+                }
+
+                i++;
+        }
+
+        r[i] = NULL;
+        return r;
+}
+
+char **strv_split_newlines(const char *s) {
+        char **l;
+        size_t n;
+
+        assert(s);
+
+        /* Special version of strv_split() that splits on newlines and
+         * suppresses an empty string at the end */
+
+        l = strv_split(s, NEWLINE);
+        if (!l)
+                return NULL;
+
+        n = strv_length(l);
+        if (n <= 0)
+                return l;
+
+        if (isempty(l[n - 1]))
+                l[n - 1] = mfree(l[n - 1]);
+
+        return l;
+}
+
+int strv_split_extract(char ***t, const char *s, const char *separators, ExtractFlags flags) {
+        _cleanup_strv_free_ char **l = NULL;
+        size_t n = 0, allocated = 0;
+        int r;
+
+        assert(t);
+        assert(s);
+
+        for (;;) {
+                _cleanup_free_ char *word = NULL;
+
+                r = extract_first_word(&s, &word, separators, flags);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (!GREEDY_REALLOC(l, allocated, n + 2))
+                        return -ENOMEM;
+
+                l[n++] = TAKE_PTR(word);
+
+                l[n] = NULL;
+        }
+
+        if (!l) {
+                l = new0(char*, 1);
+                if (!l)
+                        return -ENOMEM;
+        }
+
+        *t = TAKE_PTR(l);
+
+        return (int) n;
+}
+
+char *strv_join_prefix(char **l, const char *separator, const char *prefix) {
+        char *r, *e;
+        char **s;
+        size_t n, k, m;
+
+        if (!separator)
+                separator = " ";
+
+        k = strlen(separator);
+        m = strlen_ptr(prefix);
+
+        n = 0;
+        STRV_FOREACH(s, l) {
+                if (s != l)
+                        n += k;
+                n += m + strlen(*s);
+        }
+
+        r = new(char, n+1);
+        if (!r)
+                return NULL;
+
+        e = r;
+        STRV_FOREACH(s, l) {
+                if (s != l)
+                        e = stpcpy(e, separator);
+
+                if (prefix)
+                        e = stpcpy(e, prefix);
+
+                e = stpcpy(e, *s);
+        }
+
+        *e = 0;
+
+        return r;
+}
+
+int strv_push(char ***l, char *value) {
+        char **c;
+        size_t n, m;
+
+        if (!value)
+                return 0;
+
+        n = strv_length(*l);
+
+        /* Increase and check for overflow */
+        m = n + 2;
+        if (m < n)
+                return -ENOMEM;
+
+        c = reallocarray(*l, m, sizeof(char*));
+        if (!c)
+                return -ENOMEM;
+
+        c[n] = value;
+        c[n+1] = NULL;
+
+        *l = c;
+        return 0;
+}
+
+int strv_push_pair(char ***l, char *a, char *b) {
+        char **c;
+        size_t n, m;
+
+        if (!a && !b)
+                return 0;
+
+        n = strv_length(*l);
+
+        /* increase and check for overflow */
+        m = n + !!a + !!b + 1;
+        if (m < n)
+                return -ENOMEM;
+
+        c = reallocarray(*l, m, sizeof(char*));
+        if (!c)
+                return -ENOMEM;
+
+        if (a)
+                c[n++] = a;
+        if (b)
+                c[n++] = b;
+        c[n] = NULL;
+
+        *l = c;
+        return 0;
+}
+
+int strv_insert(char ***l, size_t position, char *value) {
+        char **c;
+        size_t n, m, i;
+
+        if (!value)
+                return 0;
+
+        n = strv_length(*l);
+        position = MIN(position, n);
+
+        /* increase and check for overflow */
+        m = n + 2;
+        if (m < n)
+                return -ENOMEM;
+
+        c = new(char*, m);
+        if (!c)
+                return -ENOMEM;
+
+        for (i = 0; i < position; i++)
+                c[i] = (*l)[i];
+        c[position] = value;
+        for (i = position; i < n; i++)
+                c[i+1] = (*l)[i];
+
+        c[n+1] = NULL;
+
+        free(*l);
+        *l = c;
+
+        return 0;
+}
+
+int strv_consume(char ***l, char *value) {
+        int r;
+
+        r = strv_push(l, value);
+        if (r < 0)
+                free(value);
+
+        return r;
+}
+
+int strv_consume_pair(char ***l, char *a, char *b) {
+        int r;
+
+        r = strv_push_pair(l, a, b);
+        if (r < 0) {
+                free(a);
+                free(b);
+        }
+
+        return r;
+}
+
+int strv_consume_prepend(char ***l, char *value) {
+        int r;
+
+        r = strv_push_prepend(l, value);
+        if (r < 0)
+                free(value);
+
+        return r;
+}
+
+int strv_extend(char ***l, const char *value) {
+        char *v;
+
+        if (!value)
+                return 0;
+
+        v = strdup(value);
+        if (!v)
+                return -ENOMEM;
+
+        return strv_consume(l, v);
+}
+
+int strv_extend_front(char ***l, const char *value) {
+        size_t n, m;
+        char *v, **c;
+
+        assert(l);
+
+        /* Like strv_extend(), but prepends rather than appends the new entry */
+
+        if (!value)
+                return 0;
+
+        n = strv_length(*l);
+
+        /* Increase and overflow check. */
+        m = n + 2;
+        if (m < n)
+                return -ENOMEM;
+
+        v = strdup(value);
+        if (!v)
+                return -ENOMEM;
+
+        c = reallocarray(*l, m, sizeof(char*));
+        if (!c) {
+                free(v);
+                return -ENOMEM;
+        }
+
+        memmove(c+1, c, n * sizeof(char*));
+        c[0] = v;
+        c[n+1] = NULL;
+
+        *l = c;
+        return 0;
+}
+
+char **strv_uniq(char **l) {
+        char **i;
+
+        /* Drops duplicate entries. The first identical string will be
+         * kept, the others dropped */
+
+        STRV_FOREACH(i, l)
+                strv_remove(i+1, *i);
+
+        return l;
+}
+
+bool strv_is_uniq(char **l) {
+        char **i;
+
+        STRV_FOREACH(i, l)
+                if (strv_find(i+1, *i))
+                        return false;
+
+        return true;
+}
+
+char **strv_remove(char **l, const char *s) {
+        char **f, **t;
+
+        if (!l)
+                return NULL;
+
+        assert(s);
+
+        /* Drops every occurrence of s in the string list, edits
+         * in-place. */
+
+        for (f = t = l; *f; f++)
+                if (streq(*f, s))
+                        free(*f);
+                else
+                        *(t++) = *f;
+
+        *t = NULL;
+        return l;
+}
+
+char **strv_parse_nulstr(const char *s, size_t l) {
+        /* l is the length of the input data, which will be split at NULs into
+         * elements of the resulting strv. Hence, the number of items in the resulting strv
+         * will be equal to one plus the number of NUL bytes in the l bytes starting at s,
+         * unless s[l-1] is NUL, in which case the final empty string is not stored in
+         * the resulting strv, and length is equal to the number of NUL bytes.
+         *
+         * Note that contrary to a normal nulstr which cannot contain empty strings, because
+         * the input data is terminated by any two consequent NUL bytes, this parser accepts
+         * empty strings in s.
+         */
+
+        const char *p;
+        size_t c = 0, i = 0;
+        char **v;
+
+        assert(s || l <= 0);
+
+        if (l <= 0)
+                return new0(char*, 1);
+
+        for (p = s; p < s + l; p++)
+                if (*p == 0)
+                        c++;
+
+        if (s[l-1] != 0)
+                c++;
+
+        v = new0(char*, c+1);
+        if (!v)
+                return NULL;
+
+        p = s;
+        while (p < s + l) {
+                const char *e;
+
+                e = memchr(p, 0, s + l - p);
+
+                v[i] = strndup(p, e ? e - p : s + l - p);
+                if (!v[i]) {
+                        strv_free(v);
+                        return NULL;
+                }
+
+                i++;
+
+                if (!e)
+                        break;
+
+                p = e + 1;
+        }
+
+        assert(i == c);
+
+        return v;
+}
+
+char **strv_split_nulstr(const char *s) {
+        const char *i;
+        char **r = NULL;
+
+        NULSTR_FOREACH(i, s)
+                if (strv_extend(&r, i) < 0) {
+                        strv_free(r);
+                        return NULL;
+                }
+
+        if (!r)
+                return strv_new(NULL);
+
+        return r;
+}
+
+int strv_make_nulstr(char **l, char **p, size_t *q) {
+        /* A valid nulstr with two NULs at the end will be created, but
+         * q will be the length without the two trailing NULs. Thus the output
+         * string is a valid nulstr and can be iterated over using NULSTR_FOREACH,
+         * and can also be parsed by strv_parse_nulstr as long as the length
+         * is provided separately.
+         */
+
+        size_t n_allocated = 0, n = 0;
+        _cleanup_free_ char *m = NULL;
+        char **i;
+
+        assert(p);
+        assert(q);
+
+        STRV_FOREACH(i, l) {
+                size_t z;
+
+                z = strlen(*i);
+
+                if (!GREEDY_REALLOC(m, n_allocated, n + z + 2))
+                        return -ENOMEM;
+
+                memcpy(m + n, *i, z + 1);
+                n += z + 1;
+        }
+
+        if (!m) {
+                m = new0(char, 1);
+                if (!m)
+                        return -ENOMEM;
+                n = 1;
+        } else
+                /* make sure there is a second extra NUL at the end of resulting nulstr */
+                m[n] = '\0';
+
+        assert(n > 0);
+        *p = m;
+        *q = n - 1;
+
+        m = NULL;
+
+        return 0;
+}
+
+bool strv_overlap(char **a, char **b) {
+        char **i;
+
+        STRV_FOREACH(i, a)
+                if (strv_contains(b, *i))
+                        return true;
+
+        return false;
+}
+
+static int str_compare(char * const *a, char * const *b) {
+        return strcmp(*a, *b);
+}
+
+char **strv_sort(char **l) {
+        typesafe_qsort(l, strv_length(l), str_compare);
+        return l;
+}
+
+bool strv_equal(char **a, char **b) {
+
+        if (strv_isempty(a))
+                return strv_isempty(b);
+
+        if (strv_isempty(b))
+                return false;
+
+        for ( ; *a || *b; ++a, ++b)
+                if (!streq_ptr(*a, *b))
+                        return false;
+
+        return true;
+}
+
+void strv_print(char **l) {
+        char **s;
+
+        STRV_FOREACH(s, l)
+                puts(*s);
+}
+
+int strv_extendf(char ***l, const char *format, ...) {
+        va_list ap;
+        char *x;
+        int r;
+
+        va_start(ap, format);
+        r = vasprintf(&x, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return strv_consume(l, x);
+}
+
+char **strv_reverse(char **l) {
+        size_t n, i;
+
+        n = strv_length(l);
+        if (n <= 1)
+                return l;
+
+        for (i = 0; i < n / 2; i++)
+                SWAP_TWO(l[i], l[n-1-i]);
+
+        return l;
+}
+
+char **strv_shell_escape(char **l, const char *bad) {
+        char **s;
+
+        /* Escapes every character in every string in l that is in bad,
+         * edits in-place, does not roll-back on error. */
+
+        STRV_FOREACH(s, l) {
+                char *v;
+
+                v = shell_escape(*s, bad);
+                if (!v)
+                        return NULL;
+
+                free(*s);
+                *s = v;
+        }
+
+        return l;
+}
+
+bool strv_fnmatch(char* const* patterns, const char *s, int flags) {
+        char* const* p;
+
+        STRV_FOREACH(p, patterns)
+                if (fnmatch(*p, s, flags) == 0)
+                        return true;
+
+        return false;
+}
+
+char ***strv_free_free(char ***l) {
+        char ***i;
+
+        if (!l)
+                return NULL;
+
+        for (i = l; *i; i++)
+                strv_free(*i);
+
+        return mfree(l);
+}
+
+char **strv_skip(char **l, size_t n) {
+
+        while (n > 0) {
+                if (strv_isempty(l))
+                        return l;
+
+                l++, n--;
+        }
+
+        return l;
+}
+
+int strv_extend_n(char ***l, const char *value, size_t n) {
+        size_t i, j, k;
+        char **nl;
+
+        assert(l);
+
+        if (!value)
+                return 0;
+        if (n == 0)
+                return 0;
+
+        /* Adds the value n times to l */
+
+        k = strv_length(*l);
+
+        nl = reallocarray(*l, k + n + 1, sizeof(char *));
+        if (!nl)
+                return -ENOMEM;
+
+        *l = nl;
+
+        for (i = k; i < k + n; i++) {
+                nl[i] = strdup(value);
+                if (!nl[i])
+                        goto rollback;
+        }
+
+        nl[i] = NULL;
+        return 0;
+
+rollback:
+        for (j = k; j < i; j++)
+                free(nl[j]);
+
+        nl[k] = NULL;
+        return -ENOMEM;
+}
+
+int fputstrv(FILE *f, char **l, const char *separator, bool *space) {
+        bool b = false;
+        char **s;
+        int r;
+
+        /* Like fputs(), but for strv, and with a less stupid argument order */
+
+        if (!space)
+                space = &b;
+
+        STRV_FOREACH(s, l) {
+                r = fputs_with_space(f, *s, separator, space);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
diff --git a/src/basic/strv.h b/src/basic/strv.h
new file mode 100644
index 0000000..392cab6
--- /dev/null
+++ b/src/basic/strv.h
@@ -0,0 +1,190 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <fnmatch.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "macro.h"
+#include "string-util.h"
+#include "util.h"
+
+char *strv_find(char **l, const char *name) _pure_;
+char *strv_find_prefix(char **l, const char *name) _pure_;
+char *strv_find_startswith(char **l, const char *name) _pure_;
+
+char **strv_free(char **l);
+DEFINE_TRIVIAL_CLEANUP_FUNC(char**, strv_free);
+#define _cleanup_strv_free_ _cleanup_(strv_freep)
+
+char **strv_free_erase(char **l);
+DEFINE_TRIVIAL_CLEANUP_FUNC(char**, strv_free_erase);
+#define _cleanup_strv_free_erase_ _cleanup_(strv_free_erasep)
+
+void strv_clear(char **l);
+
+char **strv_copy(char * const *l);
+size_t strv_length(char * const *l) _pure_;
+
+int strv_extend_strv(char ***a, char **b, bool filter_duplicates);
+int strv_extend_strv_concat(char ***a, char **b, const char *suffix);
+int strv_extend(char ***l, const char *value);
+int strv_extendf(char ***l, const char *format, ...) _printf_(2,0);
+int strv_extend_front(char ***l, const char *value);
+int strv_push(char ***l, char *value);
+int strv_push_pair(char ***l, char *a, char *b);
+int strv_insert(char ***l, size_t position, char *value);
+
+static inline int strv_push_prepend(char ***l, char *value) {
+        return strv_insert(l, 0, value);
+}
+
+int strv_consume(char ***l, char *value);
+int strv_consume_pair(char ***l, char *a, char *b);
+int strv_consume_prepend(char ***l, char *value);
+
+char **strv_remove(char **l, const char *s);
+char **strv_uniq(char **l);
+bool strv_is_uniq(char **l);
+
+bool strv_equal(char **a, char **b);
+
+#define strv_contains(l, s) (!!strv_find((l), (s)))
+
+char **strv_new_internal(const char *x, ...) _sentinel_;
+char **strv_new_ap(const char *x, va_list ap);
+#define strv_new(...) strv_new_internal(__VA_ARGS__, NULL)
+
+#define STRV_IGNORE ((const char *) -1)
+
+static inline const char* STRV_IFNOTNULL(const char *x) {
+        return x ? x : STRV_IGNORE;
+}
+
+static inline bool strv_isempty(char * const *l) {
+        return !l || !*l;
+}
+
+char **strv_split_full(const char *s, const char *separator, SplitFlags flags);
+static inline char **strv_split(const char *s, const char *separator) {
+        return strv_split_full(s, separator, 0);
+}
+char **strv_split_newlines(const char *s);
+
+int strv_split_extract(char ***t, const char *s, const char *separators, ExtractFlags flags);
+
+char *strv_join_prefix(char **l, const char *separator, const char *prefix);
+static inline char *strv_join(char **l, const char *separator) {
+        return strv_join_prefix(l, separator, NULL);
+}
+
+char **strv_parse_nulstr(const char *s, size_t l);
+char **strv_split_nulstr(const char *s);
+int strv_make_nulstr(char **l, char **p, size_t *n);
+
+bool strv_overlap(char **a, char **b) _pure_;
+
+#define STRV_FOREACH(s, l)                      \
+        for ((s) = (l); (s) && *(s); (s)++)
+
+#define STRV_FOREACH_BACKWARDS(s, l)                                \
+        for (s = ({                                                 \
+                        char **_l = l;                              \
+                        _l ? _l + strv_length(_l) - 1U : NULL;      \
+                        });                                         \
+             (l) && ((s) >= (l));                                   \
+             (s)--)
+
+#define STRV_FOREACH_PAIR(x, y, l)               \
+        for ((x) = (l), (y) = (x+1); (x) && *(x) && *(y); (x) += 2, (y) = (x + 1))
+
+char **strv_sort(char **l);
+void strv_print(char **l);
+
+#define STRV_MAKE(...) ((char**) ((const char*[]) { __VA_ARGS__, NULL }))
+
+#define STRV_MAKE_EMPTY ((char*[1]) { NULL })
+
+#define strv_from_stdarg_alloca(first)                          \
+        ({                                                      \
+                char **_l;                                      \
+                                                                \
+                if (!first)                                     \
+                        _l = (char**) &first;                   \
+                else {                                          \
+                        size_t _n;                              \
+                        va_list _ap;                            \
+                                                                \
+                        _n = 1;                                 \
+                        va_start(_ap, first);                   \
+                        while (va_arg(_ap, char*))              \
+                                _n++;                           \
+                        va_end(_ap);                            \
+                                                                \
+                        _l = newa(char*, _n+1);                 \
+                        _l[_n = 0] = (char*) first;             \
+                        va_start(_ap, first);                   \
+                        for (;;) {                              \
+                                _l[++_n] = va_arg(_ap, char*);  \
+                                if (!_l[_n])                    \
+                                        break;                  \
+                        }                                       \
+                        va_end(_ap);                            \
+                }                                               \
+                _l;                                             \
+        })
+
+#define STR_IN_SET(x, ...) strv_contains(STRV_MAKE(__VA_ARGS__), x)
+#define STRPTR_IN_SET(x, ...)                                    \
+        ({                                                       \
+                const char* _x = (x);                            \
+                _x && strv_contains(STRV_MAKE(__VA_ARGS__), _x); \
+        })
+
+#define STARTSWITH_SET(p, ...)                                  \
+        ({                                                      \
+                const char *_p = (p);                           \
+                char  *_found = NULL, **_i;                     \
+                STRV_FOREACH(_i, STRV_MAKE(__VA_ARGS__)) {      \
+                        _found = startswith(_p, *_i);           \
+                        if (_found)                             \
+                                break;                          \
+                }                                               \
+                _found;                                         \
+        })
+
+#define FOREACH_STRING(x, y, ...)                                       \
+        for (char **_l = STRV_MAKE(({ x = y; }), ##__VA_ARGS__);        \
+             x;                                                         \
+             x = *(++_l))
+
+char **strv_reverse(char **l);
+char **strv_shell_escape(char **l, const char *bad);
+
+bool strv_fnmatch(char* const* patterns, const char *s, int flags);
+
+static inline bool strv_fnmatch_or_empty(char* const* patterns, const char *s, int flags) {
+        assert(s);
+        return strv_isempty(patterns) ||
+               strv_fnmatch(patterns, s, flags);
+}
+
+char ***strv_free_free(char ***l);
+DEFINE_TRIVIAL_CLEANUP_FUNC(char***, strv_free_free);
+
+char **strv_skip(char **l, size_t n);
+
+int strv_extend_n(char ***l, const char *value, size_t n);
+
+int fputstrv(FILE *f, char **l, const char *separator, bool *space);
+
+#define strv_free_and_replace(a, b)             \
+        ({                                      \
+                strv_free(a);                   \
+                (a) = (b);                      \
+                (b) = NULL;                     \
+                0;                              \
+        })
diff --git a/src/basic/strxcpyx.c b/src/basic/strxcpyx.c
new file mode 100644
index 0000000..9210277
--- /dev/null
+++ b/src/basic/strxcpyx.c
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+/*
+ * Concatenates/copies strings. In any case, terminates in all cases
+ * with '\0' and moves the @dest pointer forward to the added '\0'.
+ * Returns the remaining size, and 0 if the string was truncated.
+ *
+ * Due to the intended usage, these helpers silently noop invocations
+ * having zero size.  This is technically an exception to the above
+ * statement "terminates in all cases".  It's unexpected for such calls to
+ * occur outside of a loop where this is the preferred behavior.
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "strxcpyx.h"
+
+size_t strpcpy(char **dest, size_t size, const char *src) {
+        size_t len;
+
+        assert(dest);
+        assert(src);
+
+        if (size == 0)
+                return 0;
+
+        len = strlen(src);
+        if (len >= size) {
+                if (size > 1)
+                        *dest = mempcpy(*dest, src, size-1);
+                size = 0;
+        } else if (len > 0) {
+                *dest = mempcpy(*dest, src, len);
+                size -= len;
+        }
+
+        *dest[0] = '\0';
+        return size;
+}
+
+size_t strpcpyf(char **dest, size_t size, const char *src, ...) {
+        va_list va;
+        int i;
+
+        assert(dest);
+        assert(src);
+
+        if (size == 0)
+                return 0;
+
+        va_start(va, src);
+        i = vsnprintf(*dest, size, src, va);
+        if (i < (int)size) {
+                *dest += i;
+                size -= i;
+        } else
+                size = 0;
+        va_end(va);
+        return size;
+}
+
+size_t strpcpyl(char **dest, size_t size, const char *src, ...) {
+        va_list va;
+
+        assert(dest);
+        assert(src);
+
+        va_start(va, src);
+        do {
+                size = strpcpy(dest, size, src);
+                src = va_arg(va, char *);
+        } while (src);
+        va_end(va);
+        return size;
+}
+
+size_t strscpy(char *dest, size_t size, const char *src) {
+        char *s;
+
+        assert(dest);
+        assert(src);
+
+        s = dest;
+        return strpcpy(&s, size, src);
+}
+
+size_t strscpyl(char *dest, size_t size, const char *src, ...) {
+        va_list va;
+        char *s;
+
+        assert(dest);
+        assert(src);
+
+        va_start(va, src);
+        s = dest;
+        do {
+                size = strpcpy(&s, size, src);
+                src = va_arg(va, char *);
+        } while (src);
+        va_end(va);
+
+        return size;
+}
diff --git a/src/basic/strxcpyx.h b/src/basic/strxcpyx.h
new file mode 100644
index 0000000..0f2b749
--- /dev/null
+++ b/src/basic/strxcpyx.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stddef.h>
+
+#include "macro.h"
+
+size_t strpcpy(char **dest, size_t size, const char *src);
+size_t strpcpyf(char **dest, size_t size, const char *src, ...) _printf_(3, 4);
+size_t strpcpyl(char **dest, size_t size, const char *src, ...) _sentinel_;
+size_t strscpy(char *dest, size_t size, const char *src);
+size_t strscpyl(char *dest, size_t size, const char *src, ...) _sentinel_;
diff --git a/src/basic/syslog-util.c b/src/basic/syslog-util.c
new file mode 100644
index 0000000..fe12948
--- /dev/null
+++ b/src/basic/syslog-util.c
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <string.h>
+#include <syslog.h>
+
+#include "hexdecoct.h"
+#include "macro.h"
+#include "string-table.h"
+#include "syslog-util.h"
+
+int syslog_parse_priority(const char **p, int *priority, bool with_facility) {
+        int a = 0, b = 0, c = 0;
+        const char *end;
+        size_t k;
+
+        assert(p);
+        assert(*p);
+        assert(priority);
+
+        if ((*p)[0] != '<')
+                return 0;
+
+        end = strchr(*p, '>');
+        if (!end)
+                return 0;
+
+        k = end - *p;
+        assert(k > 0);
+
+        if (k == 2)
+                c = undecchar((*p)[1]);
+        else if (k == 3) {
+                b = undecchar((*p)[1]);
+                c = undecchar((*p)[2]);
+        } else if (k == 4) {
+                a = undecchar((*p)[1]);
+                b = undecchar((*p)[2]);
+                c = undecchar((*p)[3]);
+        } else
+                return 0;
+
+        if (a < 0 || b < 0 || c < 0 ||
+            (!with_facility && (a || b || c > 7)))
+                return 0;
+
+        if (with_facility)
+                *priority = a*100 + b*10 + c;
+        else
+                *priority = (*priority & LOG_FACMASK) | c;
+
+        *p += k + 1;
+        return 1;
+}
+
+static const char *const log_facility_unshifted_table[LOG_NFACILITIES] = {
+        [LOG_FAC(LOG_KERN)] = "kern",
+        [LOG_FAC(LOG_USER)] = "user",
+        [LOG_FAC(LOG_MAIL)] = "mail",
+        [LOG_FAC(LOG_DAEMON)] = "daemon",
+        [LOG_FAC(LOG_AUTH)] = "auth",
+        [LOG_FAC(LOG_SYSLOG)] = "syslog",
+        [LOG_FAC(LOG_LPR)] = "lpr",
+        [LOG_FAC(LOG_NEWS)] = "news",
+        [LOG_FAC(LOG_UUCP)] = "uucp",
+        [LOG_FAC(LOG_CRON)] = "cron",
+        [LOG_FAC(LOG_AUTHPRIV)] = "authpriv",
+        [LOG_FAC(LOG_FTP)] = "ftp",
+        [LOG_FAC(LOG_LOCAL0)] = "local0",
+        [LOG_FAC(LOG_LOCAL1)] = "local1",
+        [LOG_FAC(LOG_LOCAL2)] = "local2",
+        [LOG_FAC(LOG_LOCAL3)] = "local3",
+        [LOG_FAC(LOG_LOCAL4)] = "local4",
+        [LOG_FAC(LOG_LOCAL5)] = "local5",
+        [LOG_FAC(LOG_LOCAL6)] = "local6",
+        [LOG_FAC(LOG_LOCAL7)] = "local7"
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(log_facility_unshifted, int, LOG_FAC(~0));
+
+bool log_facility_unshifted_is_valid(int facility) {
+        return facility >= 0 && facility <= LOG_FAC(~0);
+}
+
+static const char *const log_level_table[] = {
+        [LOG_EMERG] = "emerg",
+        [LOG_ALERT] = "alert",
+        [LOG_CRIT] = "crit",
+        [LOG_ERR] = "err",
+        [LOG_WARNING] = "warning",
+        [LOG_NOTICE] = "notice",
+        [LOG_INFO] = "info",
+        [LOG_DEBUG] = "debug"
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(log_level, int, LOG_DEBUG);
+
+bool log_level_is_valid(int level) {
+        return level >= 0 && level <= LOG_DEBUG;
+}
diff --git a/src/basic/syslog-util.h b/src/basic/syslog-util.h
new file mode 100644
index 0000000..8f419e8
--- /dev/null
+++ b/src/basic/syslog-util.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+int log_facility_unshifted_to_string_alloc(int i, char **s);
+int log_facility_unshifted_from_string(const char *s);
+bool log_facility_unshifted_is_valid(int faciliy);
+
+int log_level_to_string_alloc(int i, char **s);
+int log_level_from_string(const char *s);
+bool log_level_is_valid(int level);
+
+int syslog_parse_priority(const char **p, int *priority, bool with_facility);
diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c
new file mode 100644
index 0000000..0f38120
--- /dev/null
+++ b/src/basic/terminal-util.c
@@ -0,0 +1,1318 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <linux/kd.h>
+#include <linux/tiocl.h>
+#include <linux/vt.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/inotify.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/sysmacros.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "copy.h"
+#include "def.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "log.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "proc-cmdline.h"
+#include "process-util.h"
+#include "socket-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
+#include "time-util.h"
+#include "util.h"
+
+static volatile unsigned cached_columns = 0;
+static volatile unsigned cached_lines = 0;
+
+static volatile int cached_on_tty = -1;
+static volatile int cached_colors_enabled = -1;
+static volatile int cached_underline_enabled = -1;
+
+int chvt(int vt) {
+        _cleanup_close_ int fd;
+
+        /* Switch to the specified vt number. If the VT is specified <= 0 switch to the VT the kernel log messages go,
+         * if that's configured. */
+
+        fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
+        if (fd < 0)
+                return -errno;
+
+        if (vt <= 0) {
+                int tiocl[2] = {
+                        TIOCL_GETKMSGREDIRECT,
+                        0
+                };
+
+                if (ioctl(fd, TIOCLINUX, tiocl) < 0)
+                        return -errno;
+
+                vt = tiocl[0] <= 0 ? 1 : tiocl[0];
+        }
+
+        if (ioctl(fd, VT_ACTIVATE, vt) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) {
+        _cleanup_free_ char *line = NULL;
+        struct termios old_termios;
+        int r;
+
+        assert(f);
+        assert(ret);
+
+        /* If this is a terminal, then switch canonical mode off, so that we can read a single character */
+        if (tcgetattr(fileno(f), &old_termios) >= 0) {
+                struct termios new_termios = old_termios;
+
+                new_termios.c_lflag &= ~ICANON;
+                new_termios.c_cc[VMIN] = 1;
+                new_termios.c_cc[VTIME] = 0;
+
+                if (tcsetattr(fileno(f), TCSADRAIN, &new_termios) >= 0) {
+                        char c;
+
+                        if (t != USEC_INFINITY) {
+                                if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) {
+                                        (void) tcsetattr(fileno(f), TCSADRAIN, &old_termios);
+                                        return -ETIMEDOUT;
+                                }
+                        }
+
+                        r = safe_fgetc(f, &c);
+                        (void) tcsetattr(fileno(f), TCSADRAIN, &old_termios);
+                        if (r < 0)
+                                return r;
+                        if (r == 0)
+                                return -EIO;
+
+                        if (need_nl)
+                                *need_nl = c != '\n';
+
+                        *ret = c;
+                        return 0;
+                }
+        }
+
+        if (t != USEC_INFINITY) {
+                if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0)
+                        return -ETIMEDOUT;
+        }
+
+        /* If this is not a terminal, then read a full line instead */
+
+        r = read_line(f, 16, &line); /* longer than necessary, to eat up UTF-8 chars/vt100 key sequences */
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -EIO;
+
+        if (strlen(line) != 1)
+                return -EBADMSG;
+
+        if (need_nl)
+                *need_nl = false;
+
+        *ret = line[0];
+        return 0;
+}
+
+#define DEFAULT_ASK_REFRESH_USEC (2*USEC_PER_SEC)
+
+int ask_char(char *ret, const char *replies, const char *fmt, ...) {
+        int r;
+
+        assert(ret);
+        assert(replies);
+        assert(fmt);
+
+        for (;;) {
+                va_list ap;
+                char c;
+                bool need_nl = true;
+
+                if (colors_enabled())
+                        fputs(ANSI_HIGHLIGHT, stdout);
+
+                putchar('\r');
+
+                va_start(ap, fmt);
+                vprintf(fmt, ap);
+                va_end(ap);
+
+                if (colors_enabled())
+                        fputs(ANSI_NORMAL, stdout);
+
+                fflush(stdout);
+
+                r = read_one_char(stdin, &c, DEFAULT_ASK_REFRESH_USEC, &need_nl);
+                if (r < 0) {
+
+                        if (r == -ETIMEDOUT)
+                                continue;
+
+                        if (r == -EBADMSG) {
+                                puts("Bad input, please try again.");
+                                continue;
+                        }
+
+                        putchar('\n');
+                        return r;
+                }
+
+                if (need_nl)
+                        putchar('\n');
+
+                if (strchr(replies, c)) {
+                        *ret = c;
+                        return 0;
+                }
+
+                puts("Read unexpected character, please try again.");
+        }
+}
+
+int ask_string(char **ret, const char *text, ...) {
+        int r;
+
+        assert(ret);
+        assert(text);
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                va_list ap;
+
+                if (colors_enabled())
+                        fputs(ANSI_HIGHLIGHT, stdout);
+
+                va_start(ap, text);
+                vprintf(text, ap);
+                va_end(ap);
+
+                if (colors_enabled())
+                        fputs(ANSI_NORMAL, stdout);
+
+                fflush(stdout);
+
+                r = read_line(stdin, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return -EIO;
+
+                if (!isempty(line)) {
+                        *ret = TAKE_PTR(line);
+                        return 0;
+                }
+        }
+}
+
+int reset_terminal_fd(int fd, bool switch_to_text) {
+        struct termios termios;
+        int r = 0;
+
+        /* Set terminal to some sane defaults */
+
+        assert(fd >= 0);
+
+        /* We leave locked terminal attributes untouched, so that
+         * Plymouth may set whatever it wants to set, and we don't
+         * interfere with that. */
+
+        /* Disable exclusive mode, just in case */
+        (void) ioctl(fd, TIOCNXCL);
+
+        /* Switch to text mode */
+        if (switch_to_text)
+                (void) ioctl(fd, KDSETMODE, KD_TEXT);
+
+        /* Set default keyboard mode */
+        (void) vt_reset_keyboard(fd);
+
+        if (tcgetattr(fd, &termios) < 0) {
+                r = -errno;
+                goto finish;
+        }
+
+        /* We only reset the stuff that matters to the software. How
+         * hardware is set up we don't touch assuming that somebody
+         * else will do that for us */
+
+        termios.c_iflag &= ~(IGNBRK | BRKINT | ISTRIP | INLCR | IGNCR | IUCLC);
+        termios.c_iflag |= ICRNL | IMAXBEL | IUTF8;
+        termios.c_oflag |= ONLCR;
+        termios.c_cflag |= CREAD;
+        termios.c_lflag = ISIG | ICANON | IEXTEN | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOPRT | ECHOKE;
+
+        termios.c_cc[VINTR]    =   03;  /* ^C */
+        termios.c_cc[VQUIT]    =  034;  /* ^\ */
+        termios.c_cc[VERASE]   = 0177;
+        termios.c_cc[VKILL]    =  025;  /* ^X */
+        termios.c_cc[VEOF]     =   04;  /* ^D */
+        termios.c_cc[VSTART]   =  021;  /* ^Q */
+        termios.c_cc[VSTOP]    =  023;  /* ^S */
+        termios.c_cc[VSUSP]    =  032;  /* ^Z */
+        termios.c_cc[VLNEXT]   =  026;  /* ^V */
+        termios.c_cc[VWERASE]  =  027;  /* ^W */
+        termios.c_cc[VREPRINT] =  022;  /* ^R */
+        termios.c_cc[VEOL]     =    0;
+        termios.c_cc[VEOL2]    =    0;
+
+        termios.c_cc[VTIME]  = 0;
+        termios.c_cc[VMIN]   = 1;
+
+        if (tcsetattr(fd, TCSANOW, &termios) < 0)
+                r = -errno;
+
+finish:
+        /* Just in case, flush all crap out */
+        (void) tcflush(fd, TCIOFLUSH);
+
+        return r;
+}
+
+int reset_terminal(const char *name) {
+        _cleanup_close_ int fd = -1;
+
+        /* We open the terminal with O_NONBLOCK here, to ensure we
+         * don't block on carrier if this is a terminal with carrier
+         * configured. */
+
+        fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
+        if (fd < 0)
+                return fd;
+
+        return reset_terminal_fd(fd, true);
+}
+
+int open_terminal(const char *name, int mode) {
+        unsigned c = 0;
+        int fd;
+
+        /*
+         * If a TTY is in the process of being closed opening it might
+         * cause EIO. This is horribly awful, but unlikely to be
+         * changed in the kernel. Hence we work around this problem by
+         * retrying a couple of times.
+         *
+         * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/554172/comments/245
+         */
+
+        if (mode & O_CREAT)
+                return -EINVAL;
+
+        for (;;) {
+                fd = open(name, mode, 0);
+                if (fd >= 0)
+                        break;
+
+                if (errno != EIO)
+                        return -errno;
+
+                /* Max 1s in total */
+                if (c >= 20)
+                        return -errno;
+
+                usleep(50 * USEC_PER_MSEC);
+                c++;
+        }
+
+        if (isatty(fd) <= 0) {
+                safe_close(fd);
+                return -ENOTTY;
+        }
+
+        return fd;
+}
+
+int acquire_terminal(
+                const char *name,
+                AcquireTerminalFlags flags,
+                usec_t timeout) {
+
+        _cleanup_close_ int notify = -1, fd = -1;
+        usec_t ts = USEC_INFINITY;
+        int r, wd = -1;
+
+        assert(name);
+        assert(IN_SET(flags & ~ACQUIRE_TERMINAL_PERMISSIVE, ACQUIRE_TERMINAL_TRY, ACQUIRE_TERMINAL_FORCE, ACQUIRE_TERMINAL_WAIT));
+
+        /* We use inotify to be notified when the tty is closed. We create the watch before checking if we can actually
+         * acquire it, so that we don't lose any event.
+         *
+         * Note: strictly speaking this actually watches for the device being closed, it does *not* really watch
+         * whether a tty loses its controlling process. However, unless some rogue process uses TIOCNOTTY on /dev/tty
+         * *after* closing its tty otherwise this will not become a problem. As long as the administrator makes sure to
+         * not configure any service on the same tty as an untrusted user this should not be a problem. (Which they
+         * probably should not do anyway.) */
+
+        if ((flags & ~ACQUIRE_TERMINAL_PERMISSIVE) == ACQUIRE_TERMINAL_WAIT) {
+                notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0));
+                if (notify < 0)
+                        return -errno;
+
+                wd = inotify_add_watch(notify, name, IN_CLOSE);
+                if (wd < 0)
+                        return -errno;
+
+                if (timeout != USEC_INFINITY)
+                        ts = now(CLOCK_MONOTONIC);
+        }
+
+        for (;;) {
+                struct sigaction sa_old, sa_new = {
+                        .sa_handler = SIG_IGN,
+                        .sa_flags = SA_RESTART,
+                };
+
+                if (notify >= 0) {
+                        r = flush_fd(notify);
+                        if (r < 0)
+                                return r;
+                }
+
+                /* We pass here O_NOCTTY only so that we can check the return value TIOCSCTTY and have a reliable way
+                 * to figure out if we successfully became the controlling process of the tty */
+                fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+                if (fd < 0)
+                        return fd;
+
+                /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed if we already own the tty. */
+                assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
+
+                /* First, try to get the tty */
+                r = ioctl(fd, TIOCSCTTY,
+                          (flags & ~ACQUIRE_TERMINAL_PERMISSIVE) == ACQUIRE_TERMINAL_FORCE) < 0 ? -errno : 0;
+
+                /* Reset signal handler to old value */
+                assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
+
+                /* Success? Exit the loop now! */
+                if (r >= 0)
+                        break;
+
+                /* Any failure besides -EPERM? Fail, regardless of the mode. */
+                if (r != -EPERM)
+                        return r;
+
+                if (flags & ACQUIRE_TERMINAL_PERMISSIVE) /* If we are in permissive mode, then EPERM is fine, turn this
+                                                          * into a success. Note that EPERM is also returned if we
+                                                          * already are the owner of the TTY. */
+                        break;
+
+                if (flags != ACQUIRE_TERMINAL_WAIT) /* If we are in TRY or FORCE mode, then propagate EPERM as EPERM */
+                        return r;
+
+                assert(notify >= 0);
+                assert(wd >= 0);
+
+                for (;;) {
+                        union inotify_event_buffer buffer;
+                        struct inotify_event *e;
+                        ssize_t l;
+
+                        if (timeout != USEC_INFINITY) {
+                                usec_t n;
+
+                                assert(ts != USEC_INFINITY);
+
+                                n = now(CLOCK_MONOTONIC);
+                                if (ts + timeout < n)
+                                        return -ETIMEDOUT;
+
+                                r = fd_wait_for_event(notify, POLLIN, ts + timeout - n);
+                                if (r < 0)
+                                        return r;
+                                if (r == 0)
+                                        return -ETIMEDOUT;
+                        }
+
+                        l = read(notify, &buffer, sizeof(buffer));
+                        if (l < 0) {
+                                if (IN_SET(errno, EINTR, EAGAIN))
+                                        continue;
+
+                                return -errno;
+                        }
+
+                        FOREACH_INOTIFY_EVENT(e, buffer, l) {
+                                if (e->mask & IN_Q_OVERFLOW) /* If we hit an inotify queue overflow, simply check if the terminal is up for grabs now. */
+                                        break;
+
+                                if (e->wd != wd || !(e->mask & IN_CLOSE)) /* Safety checks */
+                                        return -EIO;
+                        }
+
+                        break;
+                }
+
+                /* We close the tty fd here since if the old session ended our handle will be dead. It's important that
+                 * we do this after sleeping, so that we don't enter an endless loop. */
+                fd = safe_close(fd);
+        }
+
+        return TAKE_FD(fd);
+}
+
+int release_terminal(void) {
+        static const struct sigaction sa_new = {
+                .sa_handler = SIG_IGN,
+                .sa_flags = SA_RESTART,
+        };
+
+        _cleanup_close_ int fd = -1;
+        struct sigaction sa_old;
+        int r;
+
+        fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
+        if (fd < 0)
+                return -errno;
+
+        /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
+         * by our own TIOCNOTTY */
+        assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
+
+        r = ioctl(fd, TIOCNOTTY) < 0 ? -errno : 0;
+
+        assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
+
+        return r;
+}
+
+int terminal_vhangup_fd(int fd) {
+        assert(fd >= 0);
+
+        if (ioctl(fd, TIOCVHANGUP) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int terminal_vhangup(const char *name) {
+        _cleanup_close_ int fd;
+
+        fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
+        if (fd < 0)
+                return fd;
+
+        return terminal_vhangup_fd(fd);
+}
+
+int vt_disallocate(const char *name) {
+        _cleanup_close_ int fd = -1;
+        const char *e, *n;
+        unsigned u;
+        int r;
+
+        /* Deallocate the VT if possible. If not possible
+         * (i.e. because it is the active one), at least clear it
+         * entirely (including the scrollback buffer) */
+
+        e = path_startswith(name, "/dev/");
+        if (!e)
+                return -EINVAL;
+
+        if (!tty_is_vc(name)) {
+                /* So this is not a VT. I guess we cannot deallocate
+                 * it then. But let's at least clear the screen */
+
+                fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+                if (fd < 0)
+                        return fd;
+
+                loop_write(fd,
+                           "\033[r"    /* clear scrolling region */
+                           "\033[H"    /* move home */
+                           "\033[2J",  /* clear screen */
+                           10, false);
+                return 0;
+        }
+
+        n = startswith(e, "tty");
+        if (!n)
+                return -EINVAL;
+
+        r = safe_atou(n, &u);
+        if (r < 0)
+                return r;
+
+        if (u <= 0)
+                return -EINVAL;
+
+        /* Try to deallocate */
+        fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK);
+        if (fd < 0)
+                return fd;
+
+        r = ioctl(fd, VT_DISALLOCATE, u);
+        fd = safe_close(fd);
+
+        if (r >= 0)
+                return 0;
+
+        if (errno != EBUSY)
+                return -errno;
+
+        /* Couldn't deallocate, so let's clear it fully with
+         * scrollback */
+        fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return fd;
+
+        loop_write(fd,
+                   "\033[r"   /* clear scrolling region */
+                   "\033[H"   /* move home */
+                   "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
+                   10, false);
+        return 0;
+}
+
+int make_console_stdio(void) {
+        int fd, r;
+
+        /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
+
+        fd = acquire_terminal("/dev/console", ACQUIRE_TERMINAL_FORCE|ACQUIRE_TERMINAL_PERMISSIVE, USEC_INFINITY);
+        if (fd < 0)
+                return log_error_errno(fd, "Failed to acquire terminal: %m");
+
+        r = reset_terminal_fd(fd, true);
+        if (r < 0)
+                log_warning_errno(r, "Failed to reset terminal, ignoring: %m");
+
+        r = rearrange_stdio(fd, fd, fd); /* This invalidates 'fd' both on success and on failure. */
+        if (r < 0)
+                return log_error_errno(r, "Failed to make terminal stdin/stdout/stderr: %m");
+
+        reset_terminal_feature_caches();
+
+        return 0;
+}
+
+bool tty_is_vc(const char *tty) {
+        assert(tty);
+
+        return vtnr_from_tty(tty) >= 0;
+}
+
+bool tty_is_console(const char *tty) {
+        assert(tty);
+
+        return streq(skip_dev_prefix(tty), "console");
+}
+
+int vtnr_from_tty(const char *tty) {
+        int i, r;
+
+        assert(tty);
+
+        tty = skip_dev_prefix(tty);
+
+        if (!startswith(tty, "tty") )
+                return -EINVAL;
+
+        if (tty[3] < '0' || tty[3] > '9')
+                return -EINVAL;
+
+        r = safe_atoi(tty+3, &i);
+        if (r < 0)
+                return r;
+
+        if (i < 0 || i > 63)
+                return -EINVAL;
+
+        return i;
+}
+
+ int resolve_dev_console(char **ret) {
+        _cleanup_free_ char *active = NULL;
+        char *tty;
+        int r;
+
+        assert(ret);
+
+        /* Resolve where /dev/console is pointing to, if /sys is actually ours (i.e. not read-only-mounted which is a
+         * sign for container setups) */
+
+        if (path_is_read_only_fs("/sys") > 0)
+                return -ENOMEDIUM;
+
+        r = read_one_line_file("/sys/class/tty/console/active", &active);
+        if (r < 0)
+                return r;
+
+        /* If multiple log outputs are configured the last one is what /dev/console points to */
+        tty = strrchr(active, ' ');
+        if (tty)
+                tty++;
+        else
+                tty = active;
+
+        if (streq(tty, "tty0")) {
+                active = mfree(active);
+
+                /* Get the active VC (e.g. tty1) */
+                r = read_one_line_file("/sys/class/tty/tty0/active", &active);
+                if (r < 0)
+                        return r;
+
+                tty = active;
+        }
+
+        if (tty == active)
+                *ret = TAKE_PTR(active);
+        else {
+                char *tmp;
+
+                tmp = strdup(tty);
+                if (!tmp)
+                        return -ENOMEM;
+
+                *ret = tmp;
+        }
+
+        return 0;
+}
+
+int get_kernel_consoles(char ***ret) {
+        _cleanup_strv_free_ char **l = NULL;
+        _cleanup_free_ char *line = NULL;
+        const char *p;
+        int r;
+
+        assert(ret);
+
+        /* If /sys is mounted read-only this means we are running in some kind of container environment. In that
+         * case /sys would reflect the host system, not us, hence ignore the data we can read from it. */
+        if (path_is_read_only_fs("/sys") > 0)
+                goto fallback;
+
+        r = read_one_line_file("/sys/class/tty/console/active", &line);
+        if (r < 0)
+                return r;
+
+        p = line;
+        for (;;) {
+                _cleanup_free_ char *tty = NULL;
+                char *path;
+
+                r = extract_first_word(&p, &tty, NULL, 0);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                if (streq(tty, "tty0")) {
+                        tty = mfree(tty);
+                        r = read_one_line_file("/sys/class/tty/tty0/active", &tty);
+                        if (r < 0)
+                                return r;
+                }
+
+                path = strappend("/dev/", tty);
+                if (!path)
+                        return -ENOMEM;
+
+                if (access(path, F_OK) < 0) {
+                        log_debug_errno(errno, "Console device %s is not accessible, skipping: %m", path);
+                        free(path);
+                        continue;
+                }
+
+                r = strv_consume(&l, path);
+                if (r < 0)
+                        return r;
+        }
+
+        if (strv_isempty(l)) {
+                log_debug("No devices found for system console");
+                goto fallback;
+        }
+
+        *ret = TAKE_PTR(l);
+
+        return 0;
+
+fallback:
+        r = strv_extend(&l, "/dev/console");
+        if (r < 0)
+                return r;
+
+        *ret = TAKE_PTR(l);
+
+        return 0;
+}
+
+bool tty_is_vc_resolve(const char *tty) {
+        _cleanup_free_ char *resolved = NULL;
+
+        assert(tty);
+
+        tty = skip_dev_prefix(tty);
+
+        if (streq(tty, "console")) {
+                if (resolve_dev_console(&resolved) < 0)
+                        return false;
+
+                tty = resolved;
+        }
+
+        return tty_is_vc(tty);
+}
+
+const char *default_term_for_tty(const char *tty) {
+        return tty && tty_is_vc_resolve(tty) ? "linux" : "vt220";
+}
+
+int fd_columns(int fd) {
+        struct winsize ws = {};
+
+        if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
+                return -errno;
+
+        if (ws.ws_col <= 0)
+                return -EIO;
+
+        return ws.ws_col;
+}
+
+unsigned columns(void) {
+        const char *e;
+        int c;
+
+        if (cached_columns > 0)
+                return cached_columns;
+
+        c = 0;
+        e = getenv("COLUMNS");
+        if (e)
+                (void) safe_atoi(e, &c);
+
+        if (c <= 0 || c > USHRT_MAX) {
+                c = fd_columns(STDOUT_FILENO);
+                if (c <= 0)
+                        c = 80;
+        }
+
+        cached_columns = c;
+        return cached_columns;
+}
+
+int fd_lines(int fd) {
+        struct winsize ws = {};
+
+        if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
+                return -errno;
+
+        if (ws.ws_row <= 0)
+                return -EIO;
+
+        return ws.ws_row;
+}
+
+unsigned lines(void) {
+        const char *e;
+        int l;
+
+        if (cached_lines > 0)
+                return cached_lines;
+
+        l = 0;
+        e = getenv("LINES");
+        if (e)
+                (void) safe_atoi(e, &l);
+
+        if (l <= 0 || l > USHRT_MAX) {
+                l = fd_lines(STDOUT_FILENO);
+                if (l <= 0)
+                        l = 24;
+        }
+
+        cached_lines = l;
+        return cached_lines;
+}
+
+/* intended to be used as a SIGWINCH sighandler */
+void columns_lines_cache_reset(int signum) {
+        cached_columns = 0;
+        cached_lines = 0;
+}
+
+void reset_terminal_feature_caches(void) {
+        cached_columns = 0;
+        cached_lines = 0;
+
+        cached_colors_enabled = -1;
+        cached_underline_enabled = -1;
+        cached_on_tty = -1;
+}
+
+bool on_tty(void) {
+
+        /* We check both stdout and stderr, so that situations where pipes on the shell are used are reliably
+         * recognized, regardless if only the output or the errors are piped to some place. Since on_tty() is generally
+         * used to default to a safer, non-interactive, non-color mode of operation it's probably good to be defensive
+         * here, and check for both. Note that we don't check for STDIN_FILENO, because it should fine to use fancy
+         * terminal functionality when outputting stuff, even if the input is piped to us. */
+
+        if (cached_on_tty < 0)
+                cached_on_tty =
+                        isatty(STDOUT_FILENO) > 0 &&
+                        isatty(STDERR_FILENO) > 0;
+
+        return cached_on_tty;
+}
+
+int getttyname_malloc(int fd, char **ret) {
+        size_t l = 100;
+        int r;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        for (;;) {
+                char path[l];
+
+                r = ttyname_r(fd, path, sizeof(path));
+                if (r == 0) {
+                        char *c;
+
+                        c = strdup(skip_dev_prefix(path));
+                        if (!c)
+                                return -ENOMEM;
+
+                        *ret = c;
+                        return 0;
+                }
+
+                if (r != ERANGE)
+                        return -r;
+
+                l *= 2;
+        }
+
+        return 0;
+}
+
+int getttyname_harder(int fd, char **r) {
+        int k;
+        char *s = NULL;
+
+        k = getttyname_malloc(fd, &s);
+        if (k < 0)
+                return k;
+
+        if (streq(s, "tty")) {
+                free(s);
+                return get_ctty(0, NULL, r);
+        }
+
+        *r = s;
+        return 0;
+}
+
+int get_ctty_devnr(pid_t pid, dev_t *d) {
+        int r;
+        _cleanup_free_ char *line = NULL;
+        const char *p;
+        unsigned long ttynr;
+
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "stat");
+        r = read_one_line_file(p, &line);
+        if (r < 0)
+                return r;
+
+        p = strrchr(line, ')');
+        if (!p)
+                return -EIO;
+
+        p++;
+
+        if (sscanf(p, " "
+                   "%*c "  /* state */
+                   "%*d "  /* ppid */
+                   "%*d "  /* pgrp */
+                   "%*d "  /* session */
+                   "%lu ", /* ttynr */
+                   &ttynr) != 1)
+                return -EIO;
+
+        if (major(ttynr) == 0 && minor(ttynr) == 0)
+                return -ENXIO;
+
+        if (d)
+                *d = (dev_t) ttynr;
+
+        return 0;
+}
+
+int get_ctty(pid_t pid, dev_t *ret_devnr, char **ret) {
+        _cleanup_free_ char *fn = NULL, *b = NULL;
+        dev_t devnr;
+        int r;
+
+        r = get_ctty_devnr(pid, &devnr);
+        if (r < 0)
+                return r;
+
+        r = device_path_make_canonical(S_IFCHR, devnr, &fn);
+        if (r < 0) {
+                if (r != -ENOENT) /* No symlink for this in /dev/char/? */
+                        return r;
+
+                if (major(devnr) == 136) {
+                        /* This is an ugly hack: PTY devices are not listed in /dev/char/, as they don't follow the
+                         * Linux device model. This means we have no nice way to match them up against their actual
+                         * device node. Let's hence do the check by the fixed, assigned major number. Normally we try
+                         * to avoid such fixed major/minor matches, but there appears to nother nice way to handle
+                         * this. */
+
+                        if (asprintf(&b, "pts/%u", minor(devnr)) < 0)
+                                return -ENOMEM;
+                } else {
+                        /* Probably something similar to the ptys which have no symlink in /dev/char/. Let's return
+                         * something vaguely useful. */
+
+                        r = device_path_make_major_minor(S_IFCHR, devnr, &fn);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        if (!b) {
+                const char *w;
+
+                w = path_startswith(fn, "/dev/");
+                if (w) {
+                        b = strdup(w);
+                        if (!b)
+                                return -ENOMEM;
+                } else
+                        b = TAKE_PTR(fn);
+        }
+
+        if (ret)
+                *ret = TAKE_PTR(b);
+
+        if (ret_devnr)
+                *ret_devnr = devnr;
+
+        return 0;
+}
+
+int ptsname_malloc(int fd, char **ret) {
+        size_t l = 100;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        for (;;) {
+                char *c;
+
+                c = new(char, l);
+                if (!c)
+                        return -ENOMEM;
+
+                if (ptsname_r(fd, c, l) == 0) {
+                        *ret = c;
+                        return 0;
+                }
+                if (errno != ERANGE) {
+                        free(c);
+                        return -errno;
+                }
+
+                free(c);
+                l *= 2;
+        }
+}
+
+int ptsname_namespace(int pty, char **ret) {
+        int no = -1, r;
+
+        /* Like ptsname(), but doesn't assume that the path is
+         * accessible in the local namespace. */
+
+        r = ioctl(pty, TIOCGPTN, &no);
+        if (r < 0)
+                return -errno;
+
+        if (no < 0)
+                return -EIO;
+
+        if (asprintf(ret, "/dev/pts/%i", no) < 0)
+                return -ENOMEM;
+
+        return 0;
+}
+
+int openpt_in_namespace(pid_t pid, int flags) {
+        _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
+        _cleanup_close_pair_ int pair[2] = { -1, -1 };
+        pid_t child;
+        int r;
+
+        assert(pid > 0);
+
+        r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
+        if (r < 0)
+                return r;
+
+        if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
+                return -errno;
+
+        r = namespace_fork("(sd-openptns)", "(sd-openpt)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG,
+                           pidnsfd, mntnsfd, -1, usernsfd, rootfd, &child);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                int master;
+
+                pair[0] = safe_close(pair[0]);
+
+                master = posix_openpt(flags|O_NOCTTY|O_CLOEXEC);
+                if (master < 0)
+                        _exit(EXIT_FAILURE);
+
+                if (unlockpt(master) < 0)
+                        _exit(EXIT_FAILURE);
+
+                if (send_one_fd(pair[1], master, 0) < 0)
+                        _exit(EXIT_FAILURE);
+
+                _exit(EXIT_SUCCESS);
+        }
+
+        pair[1] = safe_close(pair[1]);
+
+        r = wait_for_terminate_and_check("(sd-openptns)", child, 0);
+        if (r < 0)
+                return r;
+        if (r != EXIT_SUCCESS)
+                return -EIO;
+
+        return receive_one_fd(pair[0], 0);
+}
+
+int open_terminal_in_namespace(pid_t pid, const char *name, int mode) {
+        _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
+        _cleanup_close_pair_ int pair[2] = { -1, -1 };
+        pid_t child;
+        int r;
+
+        r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
+        if (r < 0)
+                return r;
+
+        if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
+                return -errno;
+
+        r = namespace_fork("(sd-terminalns)", "(sd-terminal)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG,
+                           pidnsfd, mntnsfd, -1, usernsfd, rootfd, &child);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                int master;
+
+                pair[0] = safe_close(pair[0]);
+
+                master = open_terminal(name, mode|O_NOCTTY|O_CLOEXEC);
+                if (master < 0)
+                        _exit(EXIT_FAILURE);
+
+                if (send_one_fd(pair[1], master, 0) < 0)
+                        _exit(EXIT_FAILURE);
+
+                _exit(EXIT_SUCCESS);
+        }
+
+        pair[1] = safe_close(pair[1]);
+
+        r = wait_for_terminate_and_check("(sd-terminalns)", child, 0);
+        if (r < 0)
+                return r;
+        if (r != EXIT_SUCCESS)
+                return -EIO;
+
+        return receive_one_fd(pair[0], 0);
+}
+
+static bool getenv_terminal_is_dumb(void) {
+        const char *e;
+
+        e = getenv("TERM");
+        if (!e)
+                return true;
+
+        return streq(e, "dumb");
+}
+
+bool terminal_is_dumb(void) {
+        if (!on_tty())
+                return true;
+
+        return getenv_terminal_is_dumb();
+}
+
+bool colors_enabled(void) {
+
+        /* Returns true if colors are considered supported on our stdout. For that we check $SYSTEMD_COLORS first
+         * (which is the explicit way to turn colors on/off). If that didn't work we turn colors off unless we are on a
+         * TTY. And if we are on a TTY we turn it off if $TERM is set to "dumb". There's one special tweak though: if
+         * we are PID 1 then we do not check whether we are connected to a TTY, because we don't keep /dev/console open
+         * continously due to fear of SAK, and hence things are a bit weird. */
+
+        if (cached_colors_enabled < 0) {
+                int val;
+
+                val = getenv_bool("SYSTEMD_COLORS");
+                if (val >= 0)
+                        cached_colors_enabled = val;
+                else if (getpid_cached() == 1)
+                        /* PID1 outputs to the console without holding it open all the time */
+                        cached_colors_enabled = !getenv_terminal_is_dumb();
+                else
+                        cached_colors_enabled = !terminal_is_dumb();
+        }
+
+        return cached_colors_enabled;
+}
+
+bool dev_console_colors_enabled(void) {
+        _cleanup_free_ char *s = NULL;
+        int b;
+
+        /* Returns true if we assume that color is supported on /dev/console.
+         *
+         * For that we first check if we explicitly got told to use colors or not, by checking $SYSTEMD_COLORS. If that
+         * isn't set we check whether PID 1 has $TERM set, and if not, whether TERM is set on the kernel command
+         * line. If we find $TERM set we assume color if it's not set to "dumb", similarly to how regular
+         * colors_enabled() operates. */
+
+        b = getenv_bool("SYSTEMD_COLORS");
+        if (b >= 0)
+                return b;
+
+        if (getenv_for_pid(1, "TERM", &s) <= 0)
+                (void) proc_cmdline_get_key("TERM", 0, &s);
+
+        return !streq_ptr(s, "dumb");
+}
+
+bool underline_enabled(void) {
+
+        if (cached_underline_enabled < 0) {
+
+                /* The Linux console doesn't support underlining, turn it off, but only there. */
+
+                if (colors_enabled())
+                        cached_underline_enabled = !streq_ptr(getenv("TERM"), "linux");
+                else
+                        cached_underline_enabled = false;
+        }
+
+        return cached_underline_enabled;
+}
+
+int vt_default_utf8(void) {
+        _cleanup_free_ char *b = NULL;
+        int r;
+
+        /* Read the default VT UTF8 setting from the kernel */
+
+        r = read_one_line_file("/sys/module/vt/parameters/default_utf8", &b);
+        if (r < 0)
+                return r;
+
+        return parse_boolean(b);
+}
+
+int vt_reset_keyboard(int fd) {
+        int kb;
+
+        /* If we can't read the default, then default to unicode. It's 2017 after all. */
+        kb = vt_default_utf8() != 0 ? K_UNICODE : K_XLATE;
+
+        if (ioctl(fd, KDSKBMODE, kb) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int vt_restore(int fd) {
+        static const struct vt_mode mode = {
+                .mode = VT_AUTO,
+        };
+        int r, q = 0;
+
+        r = ioctl(fd, KDSETMODE, KD_TEXT);
+        if (r < 0)
+                q = log_debug_errno(errno, "Failed to set VT in text mode, ignoring: %m");
+
+        r = vt_reset_keyboard(fd);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to reset keyboard mode, ignoring: %m");
+                if (q >= 0)
+                        q = r;
+        }
+
+        r = ioctl(fd, VT_SETMODE, &mode);
+        if (r < 0) {
+                log_debug_errno(errno, "Failed to set VT_AUTO mode, ignoring: %m");
+                if (q >= 0)
+                        q = -errno;
+        }
+
+        r = fchown(fd, 0, (gid_t) -1);
+        if (r < 0) {
+                log_debug_errno(errno, "Failed to chown VT, ignoring: %m");
+                if (q >= 0)
+                        q = -errno;
+        }
+
+        return q;
+}
+
+int vt_release(int fd, bool restore) {
+        assert(fd >= 0);
+
+        /* This function releases the VT by acknowledging the VT-switch signal
+         * sent by the kernel and optionally reset the VT in text and auto
+         * VT-switching modes. */
+
+        if (ioctl(fd, VT_RELDISP, 1) < 0)
+                return -errno;
+
+        if (restore)
+                return vt_restore(fd);
+
+        return 0;
+}
diff --git a/src/basic/terminal-util.h b/src/basic/terminal-util.h
new file mode 100644
index 0000000..c885e0a
--- /dev/null
+++ b/src/basic/terminal-util.h
@@ -0,0 +1,160 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "macro.h"
+#include "time-util.h"
+
+/* Regular colors */
+#define ANSI_BLACK   "\x1B[0;30m"
+#define ANSI_RED     "\x1B[0;31m"
+#define ANSI_GREEN   "\x1B[0;32m"
+#define ANSI_YELLOW  "\x1B[0;33m"
+#define ANSI_BLUE    "\x1B[0;34m"
+#define ANSI_MAGENTA "\x1B[0;35m"
+#define ANSI_CYAN    "\x1B[0;36m"
+#define ANSI_WHITE   "\x1B[0;37m"
+#define ANSI_GREY    "\x1B[0;2;37m"
+
+/* Bold/highlighted */
+#define ANSI_HIGHLIGHT_BLACK   "\x1B[0;1;30m"
+#define ANSI_HIGHLIGHT_RED     "\x1B[0;1;31m"
+#define ANSI_HIGHLIGHT_GREEN   "\x1B[0;1;32m"
+#define ANSI_HIGHLIGHT_YELLOW  "\x1B[0;1;33m"
+#define ANSI_HIGHLIGHT_BLUE    "\x1B[0;1;34m"
+#define ANSI_HIGHLIGHT_MAGENTA "\x1B[0;1;35m"
+#define ANSI_HIGHLIGHT_CYAN    "\x1B[0;1;36m"
+#define ANSI_HIGHLIGHT_WHITE   "\x1B[0;1;37m"
+
+/* Underlined */
+#define ANSI_HIGHLIGHT_BLACK_UNDERLINE   "\x1B[0;1;4;30m"
+#define ANSI_HIGHLIGHT_RED_UNDERLINE     "\x1B[0;1;4;31m"
+#define ANSI_HIGHLIGHT_GREEN_UNDERLINE   "\x1B[0;1;4;32m"
+#define ANSI_HIGHLIGHT_YELLOW_UNDERLINE  "\x1B[0;1;4;33m"
+#define ANSI_HIGHLIGHT_BLUE_UNDERLINE    "\x1B[0;1;4;34m"
+#define ANSI_HIGHLIGHT_MAGENTA_UNDERLINE "\x1B[0;1;4;35m"
+#define ANSI_HIGHLIGHT_CYAN_UNDERLINE    "\x1B[0;1;4;36m"
+#define ANSI_HIGHLIGHT_WHITE_UNDERLINE   "\x1B[0;1;4;37m"
+
+/* Other ANSI codes */
+#define ANSI_UNDERLINE "\x1B[0;4m"
+#define ANSI_HIGHLIGHT "\x1B[0;1;39m"
+#define ANSI_HIGHLIGHT_UNDERLINE "\x1B[0;1;4m"
+
+/* Reset/clear ANSI styles */
+#define ANSI_NORMAL "\x1B[0m"
+
+/* Erase characters until the end of the line */
+#define ANSI_ERASE_TO_END_OF_LINE "\x1B[K"
+
+/* Move cursor up one line */
+#define ANSI_REVERSE_LINEFEED "\x1BM"
+
+/* Set cursor to top left corner and clear screen */
+#define ANSI_HOME_CLEAR "\x1B[H\x1B[2J"
+
+int reset_terminal_fd(int fd, bool switch_to_text);
+int reset_terminal(const char *name);
+
+int open_terminal(const char *name, int mode);
+
+/* Flags for tweaking the way we become the controlling process of a terminal. */
+typedef enum AcquireTerminalFlags {
+        /* Try to become the controlling process of the TTY. If we can't return -EPERM. */
+        ACQUIRE_TERMINAL_TRY        = 0,
+
+        /* Tell the kernel to forcibly make us the controlling process of the TTY. Returns -EPERM if the kernel doesn't allow that. */
+        ACQUIRE_TERMINAL_FORCE      = 1,
+
+        /* If we can't become the controlling process of the TTY right-away, then wait until we can. */
+        ACQUIRE_TERMINAL_WAIT       = 2,
+
+        /* Pick one of the above, and then OR this flag in, in order to request permissive behaviour, if we can't become controlling process then don't mind */
+        ACQUIRE_TERMINAL_PERMISSIVE = 1 << 2,
+} AcquireTerminalFlags;
+
+int acquire_terminal(const char *name, AcquireTerminalFlags flags, usec_t timeout);
+int release_terminal(void);
+
+int terminal_vhangup_fd(int fd);
+int terminal_vhangup(const char *name);
+
+int chvt(int vt);
+
+int read_one_char(FILE *f, char *ret, usec_t timeout, bool *need_nl);
+int ask_char(char *ret, const char *replies, const char *text, ...) _printf_(3, 4);
+int ask_string(char **ret, const char *text, ...) _printf_(2, 3);
+
+int vt_disallocate(const char *name);
+
+int resolve_dev_console(char **ret);
+int get_kernel_consoles(char ***ret);
+bool tty_is_vc(const char *tty);
+bool tty_is_vc_resolve(const char *tty);
+bool tty_is_console(const char *tty) _pure_;
+int vtnr_from_tty(const char *tty);
+const char *default_term_for_tty(const char *tty);
+
+int make_console_stdio(void);
+
+int fd_columns(int fd);
+unsigned columns(void);
+int fd_lines(int fd);
+unsigned lines(void);
+
+void columns_lines_cache_reset(int _unused_ signum);
+void reset_terminal_feature_caches(void);
+
+bool on_tty(void);
+bool terminal_is_dumb(void);
+bool colors_enabled(void);
+bool underline_enabled(void);
+bool dev_console_colors_enabled(void);
+
+#define DEFINE_ANSI_FUNC(name, NAME)                            \
+        static inline const char *ansi_##name(void) {           \
+                return colors_enabled() ? ANSI_##NAME : "";     \
+        }
+
+#define DEFINE_ANSI_FUNC_UNDERLINE(name, NAME, REPLACEMENT)             \
+        static inline const char *ansi_##name(void) {                   \
+                return underline_enabled() ? ANSI_##NAME :              \
+                        colors_enabled() ? ANSI_##REPLACEMENT : "";     \
+        }
+
+DEFINE_ANSI_FUNC(highlight,                  HIGHLIGHT);
+DEFINE_ANSI_FUNC(highlight_red,              HIGHLIGHT_RED);
+DEFINE_ANSI_FUNC(highlight_green,            HIGHLIGHT_GREEN);
+DEFINE_ANSI_FUNC(highlight_yellow,           HIGHLIGHT_YELLOW);
+DEFINE_ANSI_FUNC(highlight_blue,             HIGHLIGHT_BLUE);
+DEFINE_ANSI_FUNC(highlight_magenta,          HIGHLIGHT_MAGENTA);
+DEFINE_ANSI_FUNC(normal,                     NORMAL);
+DEFINE_ANSI_FUNC(grey,                       GREY);
+
+DEFINE_ANSI_FUNC_UNDERLINE(underline,                  UNDERLINE, NORMAL);
+DEFINE_ANSI_FUNC_UNDERLINE(highlight_underline,        HIGHLIGHT_UNDERLINE, HIGHLIGHT);
+DEFINE_ANSI_FUNC_UNDERLINE(highlight_red_underline,    HIGHLIGHT_RED_UNDERLINE, HIGHLIGHT_RED);
+DEFINE_ANSI_FUNC_UNDERLINE(highlight_green_underline,  HIGHLIGHT_GREEN_UNDERLINE, HIGHLIGHT_GREEN);
+DEFINE_ANSI_FUNC_UNDERLINE(highlight_yellow_underline, HIGHLIGHT_YELLOW_UNDERLINE, HIGHLIGHT_YELLOW);
+DEFINE_ANSI_FUNC_UNDERLINE(highlight_blue_underline,   HIGHLIGHT_BLUE_UNDERLINE, HIGHLIGHT_BLUE);
+
+int get_ctty_devnr(pid_t pid, dev_t *d);
+int get_ctty(pid_t, dev_t *_devnr, char **r);
+
+int getttyname_malloc(int fd, char **r);
+int getttyname_harder(int fd, char **r);
+
+int ptsname_malloc(int fd, char **ret);
+int ptsname_namespace(int pty, char **ret);
+
+int openpt_in_namespace(pid_t pid, int flags);
+int open_terminal_in_namespace(pid_t pid, const char *name, int mode);
+
+int vt_default_utf8(void);
+int vt_reset_keyboard(int fd);
+int vt_restore(int fd);
+int vt_release(int fd, bool restore_vt);
diff --git a/src/basic/time-util.c b/src/basic/time-util.c
new file mode 100644
index 0000000..62cdc30
--- /dev/null
+++ b/src/basic/time-util.c
@@ -0,0 +1,1471 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/timerfd.h>
+#include <sys/timex.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing_timerfd.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+
+static clockid_t map_clock_id(clockid_t c) {
+
+        /* Some more exotic archs (s390, ppc, …) lack the "ALARM" flavour of the clocks. Thus, clock_gettime() will
+         * fail for them. Since they are essentially the same as their non-ALARM pendants (their only difference is
+         * when timers are set on them), let's just map them accordingly. This way, we can get the correct time even on
+         * those archs. */
+
+        switch (c) {
+
+        case CLOCK_BOOTTIME_ALARM:
+                return CLOCK_BOOTTIME;
+
+        case CLOCK_REALTIME_ALARM:
+                return CLOCK_REALTIME;
+
+        default:
+                return c;
+        }
+}
+
+usec_t now(clockid_t clock_id) {
+        struct timespec ts;
+
+        assert_se(clock_gettime(map_clock_id(clock_id), &ts) == 0);
+
+        return timespec_load(&ts);
+}
+
+nsec_t now_nsec(clockid_t clock_id) {
+        struct timespec ts;
+
+        assert_se(clock_gettime(map_clock_id(clock_id), &ts) == 0);
+
+        return timespec_load_nsec(&ts);
+}
+
+dual_timestamp* dual_timestamp_get(dual_timestamp *ts) {
+        assert(ts);
+
+        ts->realtime = now(CLOCK_REALTIME);
+        ts->monotonic = now(CLOCK_MONOTONIC);
+
+        return ts;
+}
+
+triple_timestamp* triple_timestamp_get(triple_timestamp *ts) {
+        assert(ts);
+
+        ts->realtime = now(CLOCK_REALTIME);
+        ts->monotonic = now(CLOCK_MONOTONIC);
+        ts->boottime = clock_boottime_supported() ? now(CLOCK_BOOTTIME) : USEC_INFINITY;
+
+        return ts;
+}
+
+dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u) {
+        int64_t delta;
+        assert(ts);
+
+        if (u == USEC_INFINITY || u <= 0) {
+                ts->realtime = ts->monotonic = u;
+                return ts;
+        }
+
+        ts->realtime = u;
+
+        delta = (int64_t) now(CLOCK_REALTIME) - (int64_t) u;
+        ts->monotonic = usec_sub_signed(now(CLOCK_MONOTONIC), delta);
+
+        return ts;
+}
+
+triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u) {
+        int64_t delta;
+
+        assert(ts);
+
+        if (u == USEC_INFINITY || u <= 0) {
+                ts->realtime = ts->monotonic = ts->boottime = u;
+                return ts;
+        }
+
+        ts->realtime = u;
+        delta = (int64_t) now(CLOCK_REALTIME) - (int64_t) u;
+        ts->monotonic = usec_sub_signed(now(CLOCK_MONOTONIC), delta);
+        ts->boottime = clock_boottime_supported() ? usec_sub_signed(now(CLOCK_BOOTTIME), delta) : USEC_INFINITY;
+
+        return ts;
+}
+
+dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u) {
+        int64_t delta;
+        assert(ts);
+
+        if (u == USEC_INFINITY) {
+                ts->realtime = ts->monotonic = USEC_INFINITY;
+                return ts;
+        }
+
+        ts->monotonic = u;
+        delta = (int64_t) now(CLOCK_MONOTONIC) - (int64_t) u;
+        ts->realtime = usec_sub_signed(now(CLOCK_REALTIME), delta);
+
+        return ts;
+}
+
+dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u) {
+        int64_t delta;
+
+        if (u == USEC_INFINITY) {
+                ts->realtime = ts->monotonic = USEC_INFINITY;
+                return ts;
+        }
+
+        dual_timestamp_get(ts);
+        delta = (int64_t) now(clock_boottime_or_monotonic()) - (int64_t) u;
+        ts->realtime = usec_sub_signed(ts->realtime, delta);
+        ts->monotonic = usec_sub_signed(ts->monotonic, delta);
+
+        return ts;
+}
+
+usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock) {
+
+        switch (clock) {
+
+        case CLOCK_REALTIME:
+        case CLOCK_REALTIME_ALARM:
+                return ts->realtime;
+
+        case CLOCK_MONOTONIC:
+                return ts->monotonic;
+
+        case CLOCK_BOOTTIME:
+        case CLOCK_BOOTTIME_ALARM:
+                return ts->boottime;
+
+        default:
+                return USEC_INFINITY;
+        }
+}
+
+usec_t timespec_load(const struct timespec *ts) {
+        assert(ts);
+
+        if (ts->tv_sec < 0 || ts->tv_nsec < 0)
+                return USEC_INFINITY;
+
+        if ((usec_t) ts->tv_sec > (UINT64_MAX - (ts->tv_nsec / NSEC_PER_USEC)) / USEC_PER_SEC)
+                return USEC_INFINITY;
+
+        return
+                (usec_t) ts->tv_sec * USEC_PER_SEC +
+                (usec_t) ts->tv_nsec / NSEC_PER_USEC;
+}
+
+nsec_t timespec_load_nsec(const struct timespec *ts) {
+        assert(ts);
+
+        if (ts->tv_sec < 0 || ts->tv_nsec < 0)
+                return NSEC_INFINITY;
+
+        if ((nsec_t) ts->tv_sec >= (UINT64_MAX - ts->tv_nsec) / NSEC_PER_SEC)
+                return NSEC_INFINITY;
+
+        return (nsec_t) ts->tv_sec * NSEC_PER_SEC + (nsec_t) ts->tv_nsec;
+}
+
+struct timespec *timespec_store(struct timespec *ts, usec_t u)  {
+        assert(ts);
+
+        if (u == USEC_INFINITY ||
+            u / USEC_PER_SEC >= TIME_T_MAX) {
+                ts->tv_sec = (time_t) -1;
+                ts->tv_nsec = (long) -1;
+                return ts;
+        }
+
+        ts->tv_sec = (time_t) (u / USEC_PER_SEC);
+        ts->tv_nsec = (long int) ((u % USEC_PER_SEC) * NSEC_PER_USEC);
+
+        return ts;
+}
+
+usec_t timeval_load(const struct timeval *tv) {
+        assert(tv);
+
+        if (tv->tv_sec < 0 || tv->tv_usec < 0)
+                return USEC_INFINITY;
+
+        if ((usec_t) tv->tv_sec > (UINT64_MAX - tv->tv_usec) / USEC_PER_SEC)
+                return USEC_INFINITY;
+
+        return
+                (usec_t) tv->tv_sec * USEC_PER_SEC +
+                (usec_t) tv->tv_usec;
+}
+
+struct timeval *timeval_store(struct timeval *tv, usec_t u) {
+        assert(tv);
+
+        if (u == USEC_INFINITY ||
+            u / USEC_PER_SEC > TIME_T_MAX) {
+                tv->tv_sec = (time_t) -1;
+                tv->tv_usec = (suseconds_t) -1;
+        } else {
+                tv->tv_sec = (time_t) (u / USEC_PER_SEC);
+                tv->tv_usec = (suseconds_t) (u % USEC_PER_SEC);
+        }
+
+        return tv;
+}
+
+static char *format_timestamp_internal(
+                char *buf,
+                size_t l,
+                usec_t t,
+                bool utc,
+                bool us) {
+
+        /* The weekdays in non-localized (English) form. We use this instead of the localized form, so that our
+         * generated timestamps may be parsed with parse_timestamp(), and always read the same. */
+        static const char * const weekdays[] = {
+                [0] = "Sun",
+                [1] = "Mon",
+                [2] = "Tue",
+                [3] = "Wed",
+                [4] = "Thu",
+                [5] = "Fri",
+                [6] = "Sat",
+        };
+
+        struct tm tm;
+        time_t sec;
+        size_t n;
+
+        assert(buf);
+
+        if (l <
+            3 +                  /* week day */
+            1 + 10 +             /* space and date */
+            1 + 8 +              /* space and time */
+            (us ? 1 + 6 : 0) +   /* "." and microsecond part */
+            1 + 1 +              /* space and shortest possible zone */
+            1)
+                return NULL; /* Not enough space even for the shortest form. */
+        if (t <= 0 || t == USEC_INFINITY)
+                return NULL; /* Timestamp is unset */
+
+        /* Let's not format times with years > 9999 */
+        if (t > USEC_TIMESTAMP_FORMATTABLE_MAX) {
+                assert(l >= STRLEN("--- XXXX-XX-XX XX:XX:XX") + 1);
+                strcpy(buf, "--- XXXX-XX-XX XX:XX:XX");
+                return buf;
+        }
+
+        sec = (time_t) (t / USEC_PER_SEC); /* Round down */
+
+        if (!localtime_or_gmtime_r(&sec, &tm, utc))
+                return NULL;
+
+        /* Start with the week day */
+        assert((size_t) tm.tm_wday < ELEMENTSOF(weekdays));
+        memcpy(buf, weekdays[tm.tm_wday], 4);
+
+        /* Add the main components */
+        if (strftime(buf + 3, l - 3, " %Y-%m-%d %H:%M:%S", &tm) <= 0)
+                return NULL; /* Doesn't fit */
+
+        /* Append the microseconds part, if that's requested */
+        if (us) {
+                n = strlen(buf);
+                if (n + 8 > l)
+                        return NULL; /* Microseconds part doesn't fit. */
+
+                sprintf(buf + n, ".%06"PRI_USEC, t % USEC_PER_SEC);
+        }
+
+        /* Append the timezone */
+        n = strlen(buf);
+        if (utc) {
+                /* If this is UTC then let's explicitly use the "UTC" string here, because gmtime_r() normally uses the
+                 * obsolete "GMT" instead. */
+                if (n + 5 > l)
+                        return NULL; /* "UTC" doesn't fit. */
+
+                strcpy(buf + n, " UTC");
+
+        } else if (!isempty(tm.tm_zone)) {
+                size_t tn;
+
+                /* An explicit timezone is specified, let's use it, if it fits */
+                tn = strlen(tm.tm_zone);
+                if (n + 1 + tn + 1 > l) {
+                        /* The full time zone does not fit in. Yuck. */
+
+                        if (n + 1 + _POSIX_TZNAME_MAX + 1 > l)
+                                return NULL; /* Not even enough space for the POSIX minimum (of 6)? In that case, complain that it doesn't fit */
+
+                        /* So the time zone doesn't fit in fully, but the caller passed enough space for the POSIX
+                         * minimum time zone length. In this case suppress the timezone entirely, in order not to dump
+                         * an overly long, hard to read string on the user. This should be safe, because the user will
+                         * assume the local timezone anyway if none is shown. And so does parse_timestamp(). */
+                } else {
+                        buf[n++] = ' ';
+                        strcpy(buf + n, tm.tm_zone);
+                }
+        }
+
+        return buf;
+}
+
+char *format_timestamp(char *buf, size_t l, usec_t t) {
+        return format_timestamp_internal(buf, l, t, false, false);
+}
+
+char *format_timestamp_utc(char *buf, size_t l, usec_t t) {
+        return format_timestamp_internal(buf, l, t, true, false);
+}
+
+char *format_timestamp_us(char *buf, size_t l, usec_t t) {
+        return format_timestamp_internal(buf, l, t, false, true);
+}
+
+char *format_timestamp_us_utc(char *buf, size_t l, usec_t t) {
+        return format_timestamp_internal(buf, l, t, true, true);
+}
+
+char *format_timestamp_relative(char *buf, size_t l, usec_t t) {
+        const char *s;
+        usec_t n, d;
+
+        if (t <= 0 || t == USEC_INFINITY)
+                return NULL;
+
+        n = now(CLOCK_REALTIME);
+        if (n > t) {
+                d = n - t;
+                s = "ago";
+        } else {
+                d = t - n;
+                s = "left";
+        }
+
+        if (d >= USEC_PER_YEAR)
+                snprintf(buf, l, USEC_FMT " years " USEC_FMT " months %s",
+                         d / USEC_PER_YEAR,
+                         (d % USEC_PER_YEAR) / USEC_PER_MONTH, s);
+        else if (d >= USEC_PER_MONTH)
+                snprintf(buf, l, USEC_FMT " months " USEC_FMT " days %s",
+                         d / USEC_PER_MONTH,
+                         (d % USEC_PER_MONTH) / USEC_PER_DAY, s);
+        else if (d >= USEC_PER_WEEK)
+                snprintf(buf, l, USEC_FMT " weeks " USEC_FMT " days %s",
+                         d / USEC_PER_WEEK,
+                         (d % USEC_PER_WEEK) / USEC_PER_DAY, s);
+        else if (d >= 2*USEC_PER_DAY)
+                snprintf(buf, l, USEC_FMT " days %s", d / USEC_PER_DAY, s);
+        else if (d >= 25*USEC_PER_HOUR)
+                snprintf(buf, l, "1 day " USEC_FMT "h %s",
+                         (d - USEC_PER_DAY) / USEC_PER_HOUR, s);
+        else if (d >= 6*USEC_PER_HOUR)
+                snprintf(buf, l, USEC_FMT "h %s",
+                         d / USEC_PER_HOUR, s);
+        else if (d >= USEC_PER_HOUR)
+                snprintf(buf, l, USEC_FMT "h " USEC_FMT "min %s",
+                         d / USEC_PER_HOUR,
+                         (d % USEC_PER_HOUR) / USEC_PER_MINUTE, s);
+        else if (d >= 5*USEC_PER_MINUTE)
+                snprintf(buf, l, USEC_FMT "min %s",
+                         d / USEC_PER_MINUTE, s);
+        else if (d >= USEC_PER_MINUTE)
+                snprintf(buf, l, USEC_FMT "min " USEC_FMT "s %s",
+                         d / USEC_PER_MINUTE,
+                         (d % USEC_PER_MINUTE) / USEC_PER_SEC, s);
+        else if (d >= USEC_PER_SEC)
+                snprintf(buf, l, USEC_FMT "s %s",
+                         d / USEC_PER_SEC, s);
+        else if (d >= USEC_PER_MSEC)
+                snprintf(buf, l, USEC_FMT "ms %s",
+                         d / USEC_PER_MSEC, s);
+        else if (d > 0)
+                snprintf(buf, l, USEC_FMT"us %s",
+                         d, s);
+        else
+                snprintf(buf, l, "now");
+
+        buf[l-1] = 0;
+        return buf;
+}
+
+char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy) {
+        static const struct {
+                const char *suffix;
+                usec_t usec;
+        } table[] = {
+                { "y",     USEC_PER_YEAR   },
+                { "month", USEC_PER_MONTH  },
+                { "w",     USEC_PER_WEEK   },
+                { "d",     USEC_PER_DAY    },
+                { "h",     USEC_PER_HOUR   },
+                { "min",   USEC_PER_MINUTE },
+                { "s",     USEC_PER_SEC    },
+                { "ms",    USEC_PER_MSEC   },
+                { "us",    1               },
+        };
+
+        size_t i;
+        char *p = buf;
+        bool something = false;
+
+        assert(buf);
+        assert(l > 0);
+
+        if (t == USEC_INFINITY) {
+                strncpy(p, "infinity", l-1);
+                p[l-1] = 0;
+                return p;
+        }
+
+        if (t <= 0) {
+                strncpy(p, "0", l-1);
+                p[l-1] = 0;
+                return p;
+        }
+
+        /* The result of this function can be parsed with parse_sec */
+
+        for (i = 0; i < ELEMENTSOF(table); i++) {
+                int k = 0;
+                size_t n;
+                bool done = false;
+                usec_t a, b;
+
+                if (t <= 0)
+                        break;
+
+                if (t < accuracy && something)
+                        break;
+
+                if (t < table[i].usec)
+                        continue;
+
+                if (l <= 1)
+                        break;
+
+                a = t / table[i].usec;
+                b = t % table[i].usec;
+
+                /* Let's see if we should shows this in dot notation */
+                if (t < USEC_PER_MINUTE && b > 0) {
+                        usec_t cc;
+                        signed char j;
+
+                        j = 0;
+                        for (cc = table[i].usec; cc > 1; cc /= 10)
+                                j++;
+
+                        for (cc = accuracy; cc > 1; cc /= 10) {
+                                b /= 10;
+                                j--;
+                        }
+
+                        if (j > 0) {
+                                k = snprintf(p, l,
+                                             "%s"USEC_FMT".%0*"PRI_USEC"%s",
+                                             p > buf ? " " : "",
+                                             a,
+                                             j,
+                                             b,
+                                             table[i].suffix);
+
+                                t = 0;
+                                done = true;
+                        }
+                }
+
+                /* No? Then let's show it normally */
+                if (!done) {
+                        k = snprintf(p, l,
+                                     "%s"USEC_FMT"%s",
+                                     p > buf ? " " : "",
+                                     a,
+                                     table[i].suffix);
+
+                        t = b;
+                }
+
+                n = MIN((size_t) k, l);
+
+                l -= n;
+                p += n;
+
+                something = true;
+        }
+
+        *p = 0;
+
+        return buf;
+}
+
+static int parse_timestamp_impl(const char *t, usec_t *usec, bool with_tz) {
+        static const struct {
+                const char *name;
+                const int nr;
+        } day_nr[] = {
+                { "Sunday",    0 },
+                { "Sun",       0 },
+                { "Monday",    1 },
+                { "Mon",       1 },
+                { "Tuesday",   2 },
+                { "Tue",       2 },
+                { "Wednesday", 3 },
+                { "Wed",       3 },
+                { "Thursday",  4 },
+                { "Thu",       4 },
+                { "Friday",    5 },
+                { "Fri",       5 },
+                { "Saturday",  6 },
+                { "Sat",       6 },
+        };
+
+        const char *k, *utc = NULL, *tzn = NULL;
+        struct tm tm, copy;
+        time_t x;
+        usec_t x_usec, plus = 0, minus = 0, ret;
+        int r, weekday = -1, dst = -1;
+        size_t i;
+
+        /* Allowed syntaxes:
+         *
+         *   2012-09-22 16:34:22
+         *   2012-09-22 16:34     (seconds will be set to 0)
+         *   2012-09-22           (time will be set to 00:00:00)
+         *   16:34:22             (date will be set to today)
+         *   16:34                (date will be set to today, seconds to 0)
+         *   now
+         *   yesterday            (time is set to 00:00:00)
+         *   today                (time is set to 00:00:00)
+         *   tomorrow             (time is set to 00:00:00)
+         *   +5min
+         *   -5days
+         *   @2147483647          (seconds since epoch)
+         */
+
+        assert(t);
+        assert(usec);
+
+        if (t[0] == '@' && !with_tz)
+                return parse_sec(t + 1, usec);
+
+        ret = now(CLOCK_REALTIME);
+
+        if (!with_tz) {
+                if (streq(t, "now"))
+                        goto finish;
+
+                else if (t[0] == '+') {
+                        r = parse_sec(t+1, &plus);
+                        if (r < 0)
+                                return r;
+
+                        goto finish;
+
+                } else if (t[0] == '-') {
+                        r = parse_sec(t+1, &minus);
+                        if (r < 0)
+                                return r;
+
+                        goto finish;
+
+                } else if ((k = endswith(t, " ago"))) {
+                        t = strndupa(t, k - t);
+
+                        r = parse_sec(t, &minus);
+                        if (r < 0)
+                                return r;
+
+                        goto finish;
+
+                } else if ((k = endswith(t, " left"))) {
+                        t = strndupa(t, k - t);
+
+                        r = parse_sec(t, &plus);
+                        if (r < 0)
+                                return r;
+
+                        goto finish;
+                }
+
+                /* See if the timestamp is suffixed with UTC */
+                utc = endswith_no_case(t, " UTC");
+                if (utc)
+                        t = strndupa(t, utc - t);
+                else {
+                        const char *e = NULL;
+                        int j;
+
+                        tzset();
+
+                        /* See if the timestamp is suffixed by either the DST or non-DST local timezone. Note that we only
+                         * support the local timezones here, nothing else. Not because we wouldn't want to, but simply because
+                         * there are no nice APIs available to cover this. By accepting the local time zone strings, we make
+                         * sure that all timestamps written by format_timestamp() can be parsed correctly, even though we don't
+                         * support arbitrary timezone specifications. */
+
+                        for (j = 0; j <= 1; j++) {
+
+                                if (isempty(tzname[j]))
+                                        continue;
+
+                                e = endswith_no_case(t, tzname[j]);
+                                if (!e)
+                                        continue;
+                                if (e == t)
+                                        continue;
+                                if (e[-1] != ' ')
+                                        continue;
+
+                                break;
+                        }
+
+                        if (IN_SET(j, 0, 1)) {
+                                /* Found one of the two timezones specified. */
+                                t = strndupa(t, e - t - 1);
+                                dst = j;
+                                tzn = tzname[j];
+                        }
+                }
+        }
+
+        x = (time_t) (ret / USEC_PER_SEC);
+        x_usec = 0;
+
+        if (!localtime_or_gmtime_r(&x, &tm, utc))
+                return -EINVAL;
+
+        tm.tm_isdst = dst;
+        if (!with_tz && tzn)
+                tm.tm_zone = tzn;
+
+        if (streq(t, "today")) {
+                tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
+                goto from_tm;
+
+        } else if (streq(t, "yesterday")) {
+                tm.tm_mday--;
+                tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
+                goto from_tm;
+
+        } else if (streq(t, "tomorrow")) {
+                tm.tm_mday++;
+                tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
+                goto from_tm;
+        }
+
+        for (i = 0; i < ELEMENTSOF(day_nr); i++) {
+                size_t skip;
+
+                if (!startswith_no_case(t, day_nr[i].name))
+                        continue;
+
+                skip = strlen(day_nr[i].name);
+                if (t[skip] != ' ')
+                        continue;
+
+                weekday = day_nr[i].nr;
+                t += skip + 1;
+                break;
+        }
+
+        copy = tm;
+        k = strptime(t, "%y-%m-%d %H:%M:%S", &tm);
+        if (k) {
+                if (*k == '.')
+                        goto parse_usec;
+                else if (*k == 0)
+                        goto from_tm;
+        }
+
+        tm = copy;
+        k = strptime(t, "%Y-%m-%d %H:%M:%S", &tm);
+        if (k) {
+                if (*k == '.')
+                        goto parse_usec;
+                else if (*k == 0)
+                        goto from_tm;
+        }
+
+        tm = copy;
+        k = strptime(t, "%y-%m-%d %H:%M", &tm);
+        if (k && *k == 0) {
+                tm.tm_sec = 0;
+                goto from_tm;
+        }
+
+        tm = copy;
+        k = strptime(t, "%Y-%m-%d %H:%M", &tm);
+        if (k && *k == 0) {
+                tm.tm_sec = 0;
+                goto from_tm;
+        }
+
+        tm = copy;
+        k = strptime(t, "%y-%m-%d", &tm);
+        if (k && *k == 0) {
+                tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
+                goto from_tm;
+        }
+
+        tm = copy;
+        k = strptime(t, "%Y-%m-%d", &tm);
+        if (k && *k == 0) {
+                tm.tm_sec = tm.tm_min = tm.tm_hour = 0;
+                goto from_tm;
+        }
+
+        tm = copy;
+        k = strptime(t, "%H:%M:%S", &tm);
+        if (k) {
+                if (*k == '.')
+                        goto parse_usec;
+                else if (*k == 0)
+                        goto from_tm;
+        }
+
+        tm = copy;
+        k = strptime(t, "%H:%M", &tm);
+        if (k && *k == 0) {
+                tm.tm_sec = 0;
+                goto from_tm;
+        }
+
+        return -EINVAL;
+
+parse_usec:
+        {
+                unsigned add;
+
+                k++;
+                r = parse_fractional_part_u(&k, 6, &add);
+                if (r < 0)
+                        return -EINVAL;
+
+                if (*k)
+                        return -EINVAL;
+
+                x_usec = add;
+        }
+
+from_tm:
+        if (weekday >= 0 && tm.tm_wday != weekday)
+                return -EINVAL;
+
+        x = mktime_or_timegm(&tm, utc);
+        if (x < 0)
+                return -EINVAL;
+
+        ret = (usec_t) x * USEC_PER_SEC + x_usec;
+        if (ret > USEC_TIMESTAMP_FORMATTABLE_MAX)
+                return -EINVAL;
+
+finish:
+        if (ret + plus < ret) /* overflow? */
+                return -EINVAL;
+        ret += plus;
+        if (ret > USEC_TIMESTAMP_FORMATTABLE_MAX)
+                return -EINVAL;
+
+        if (ret >= minus)
+                ret -= minus;
+        else
+                return -EINVAL;
+
+        *usec = ret;
+
+        return 0;
+}
+
+typedef struct ParseTimestampResult {
+        usec_t usec;
+        int return_value;
+} ParseTimestampResult;
+
+int parse_timestamp(const char *t, usec_t *usec) {
+        char *last_space, *tz = NULL;
+        ParseTimestampResult *shared, tmp;
+        int r;
+
+        last_space = strrchr(t, ' ');
+        if (last_space != NULL && timezone_is_valid(last_space + 1, LOG_DEBUG))
+                tz = last_space + 1;
+
+        if (!tz || endswith_no_case(t, " UTC"))
+                return parse_timestamp_impl(t, usec, false);
+
+        shared = mmap(NULL, sizeof *shared, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
+        if (shared == MAP_FAILED)
+                return negative_errno();
+
+        r = safe_fork("(sd-timestamp)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_WAIT, NULL);
+        if (r < 0) {
+                (void) munmap(shared, sizeof *shared);
+                return r;
+        }
+        if (r == 0) {
+                bool with_tz = true;
+
+                if (setenv("TZ", tz, 1) != 0) {
+                        shared->return_value = negative_errno();
+                        _exit(EXIT_FAILURE);
+                }
+
+                tzset();
+
+                /* If there is a timezone that matches the tzname fields, leave the parsing to the implementation.
+                 * Otherwise just cut it off. */
+                with_tz = !STR_IN_SET(tz, tzname[0], tzname[1]);
+
+                /* Cut off the timezone if we don't need it. */
+                if (with_tz)
+                        t = strndupa(t, last_space - t);
+
+                shared->return_value = parse_timestamp_impl(t, &shared->usec, with_tz);
+
+                _exit(EXIT_SUCCESS);
+        }
+
+        tmp = *shared;
+        if (munmap(shared, sizeof *shared) != 0)
+                return negative_errno();
+
+        if (tmp.return_value == 0)
+                *usec = tmp.usec;
+
+        return tmp.return_value;
+}
+
+static const char* extract_multiplier(const char *p, usec_t *multiplier) {
+        static const struct {
+                const char *suffix;
+                usec_t usec;
+        } table[] = {
+                { "seconds", USEC_PER_SEC    },
+                { "second",  USEC_PER_SEC    },
+                { "sec",     USEC_PER_SEC    },
+                { "s",       USEC_PER_SEC    },
+                { "minutes", USEC_PER_MINUTE },
+                { "minute",  USEC_PER_MINUTE },
+                { "min",     USEC_PER_MINUTE },
+                { "months",  USEC_PER_MONTH  },
+                { "month",   USEC_PER_MONTH  },
+                { "M",       USEC_PER_MONTH  },
+                { "msec",    USEC_PER_MSEC   },
+                { "ms",      USEC_PER_MSEC   },
+                { "m",       USEC_PER_MINUTE },
+                { "hours",   USEC_PER_HOUR   },
+                { "hour",    USEC_PER_HOUR   },
+                { "hr",      USEC_PER_HOUR   },
+                { "h",       USEC_PER_HOUR   },
+                { "days",    USEC_PER_DAY    },
+                { "day",     USEC_PER_DAY    },
+                { "d",       USEC_PER_DAY    },
+                { "weeks",   USEC_PER_WEEK   },
+                { "week",    USEC_PER_WEEK   },
+                { "w",       USEC_PER_WEEK   },
+                { "years",   USEC_PER_YEAR   },
+                { "year",    USEC_PER_YEAR   },
+                { "y",       USEC_PER_YEAR   },
+                { "usec",    1ULL            },
+                { "us",      1ULL            },
+                { "µs",      1ULL            },
+        };
+        size_t i;
+
+        for (i = 0; i < ELEMENTSOF(table); i++) {
+                char *e;
+
+                e = startswith(p, table[i].suffix);
+                if (e) {
+                        *multiplier = table[i].usec;
+                        return e;
+                }
+        }
+
+        return p;
+}
+
+int parse_time(const char *t, usec_t *usec, usec_t default_unit) {
+        const char *p, *s;
+        usec_t r = 0;
+        bool something = false;
+
+        assert(t);
+        assert(usec);
+        assert(default_unit > 0);
+
+        p = t;
+
+        p += strspn(p, WHITESPACE);
+        s = startswith(p, "infinity");
+        if (s) {
+                s += strspn(s, WHITESPACE);
+                if (*s != 0)
+                        return -EINVAL;
+
+                *usec = USEC_INFINITY;
+                return 0;
+        }
+
+        for (;;) {
+                usec_t multiplier = default_unit, k;
+                long long l;
+                char *e;
+
+                p += strspn(p, WHITESPACE);
+
+                if (*p == 0) {
+                        if (!something)
+                                return -EINVAL;
+
+                        break;
+                }
+
+                if (*p == '-') /* Don't allow "-0" */
+                        return -ERANGE;
+
+                errno = 0;
+                l = strtoll(p, &e, 10);
+                if (errno > 0)
+                        return -errno;
+                if (l < 0)
+                        return -ERANGE;
+
+                if (*e == '.') {
+                        p = e + 1;
+                        p += strspn(p, DIGITS);
+                } else if (e == p)
+                        return -EINVAL;
+                else
+                        p = e;
+
+                s = extract_multiplier(p + strspn(p, WHITESPACE), &multiplier);
+                if (s == p && *s != '\0')
+                        /* Don't allow '12.34.56', but accept '12.34 .56' or '12.34s.56'*/
+                        return -EINVAL;
+
+                p = s;
+
+                if ((usec_t) l >= USEC_INFINITY / multiplier)
+                        return -ERANGE;
+
+                k = (usec_t) l * multiplier;
+                if (k >= USEC_INFINITY - r)
+                        return -ERANGE;
+
+                r += k;
+
+                something = true;
+
+                if (*e == '.') {
+                        usec_t m = multiplier / 10;
+                        const char *b;
+
+                        for (b = e + 1; *b >= '0' && *b <= '9'; b++, m /= 10) {
+                                k = (usec_t) (*b - '0') * m;
+                                if (k >= USEC_INFINITY - r)
+                                        return -ERANGE;
+
+                                r += k;
+                        }
+
+                        /* Don't allow "0.-0", "3.+1", "3. 1", "3.sec" or "3.hoge"*/
+                        if (b == e + 1)
+                                return -EINVAL;
+                }
+        }
+
+        *usec = r;
+
+        return 0;
+}
+
+int parse_sec(const char *t, usec_t *usec) {
+        return parse_time(t, usec, USEC_PER_SEC);
+}
+
+int parse_sec_fix_0(const char *t, usec_t *ret) {
+        usec_t k;
+        int r;
+
+        assert(t);
+        assert(ret);
+
+        r = parse_sec(t, &k);
+        if (r < 0)
+                return r;
+
+        *ret = k == 0 ? USEC_INFINITY : k;
+        return r;
+}
+
+static const char* extract_nsec_multiplier(const char *p, nsec_t *multiplier) {
+        static const struct {
+                const char *suffix;
+                nsec_t nsec;
+        } table[] = {
+                { "seconds", NSEC_PER_SEC    },
+                { "second",  NSEC_PER_SEC    },
+                { "sec",     NSEC_PER_SEC    },
+                { "s",       NSEC_PER_SEC    },
+                { "minutes", NSEC_PER_MINUTE },
+                { "minute",  NSEC_PER_MINUTE },
+                { "min",     NSEC_PER_MINUTE },
+                { "months",  NSEC_PER_MONTH  },
+                { "month",   NSEC_PER_MONTH  },
+                { "M",       NSEC_PER_MONTH  },
+                { "msec",    NSEC_PER_MSEC   },
+                { "ms",      NSEC_PER_MSEC   },
+                { "m",       NSEC_PER_MINUTE },
+                { "hours",   NSEC_PER_HOUR   },
+                { "hour",    NSEC_PER_HOUR   },
+                { "hr",      NSEC_PER_HOUR   },
+                { "h",       NSEC_PER_HOUR   },
+                { "days",    NSEC_PER_DAY    },
+                { "day",     NSEC_PER_DAY    },
+                { "d",       NSEC_PER_DAY    },
+                { "weeks",   NSEC_PER_WEEK   },
+                { "week",    NSEC_PER_WEEK   },
+                { "w",       NSEC_PER_WEEK   },
+                { "years",   NSEC_PER_YEAR   },
+                { "year",    NSEC_PER_YEAR   },
+                { "y",       NSEC_PER_YEAR   },
+                { "usec",    NSEC_PER_USEC   },
+                { "us",      NSEC_PER_USEC   },
+                { "µs",      NSEC_PER_USEC   },
+                { "nsec",    1ULL            },
+                { "ns",      1ULL            },
+                { "",        1ULL            }, /* default is nsec */
+        };
+        size_t i;
+
+        for (i = 0; i < ELEMENTSOF(table); i++) {
+                char *e;
+
+                e = startswith(p, table[i].suffix);
+                if (e) {
+                        *multiplier = table[i].nsec;
+                        return e;
+                }
+        }
+
+        return p;
+}
+
+int parse_nsec(const char *t, nsec_t *nsec) {
+        const char *p, *s;
+        nsec_t r = 0;
+        bool something = false;
+
+        assert(t);
+        assert(nsec);
+
+        p = t;
+
+        p += strspn(p, WHITESPACE);
+        s = startswith(p, "infinity");
+        if (s) {
+                s += strspn(s, WHITESPACE);
+                if (*s != 0)
+                        return -EINVAL;
+
+                *nsec = NSEC_INFINITY;
+                return 0;
+        }
+
+        for (;;) {
+                nsec_t multiplier = 1, k;
+                long long l;
+                char *e;
+
+                p += strspn(p, WHITESPACE);
+
+                if (*p == 0) {
+                        if (!something)
+                                return -EINVAL;
+
+                        break;
+                }
+
+                if (*p == '-') /* Don't allow "-0" */
+                        return -ERANGE;
+
+                errno = 0;
+                l = strtoll(p, &e, 10);
+                if (errno > 0)
+                        return -errno;
+                if (l < 0)
+                        return -ERANGE;
+
+                if (*e == '.') {
+                        p = e + 1;
+                        p += strspn(p, DIGITS);
+                } else if (e == p)
+                        return -EINVAL;
+                else
+                        p = e;
+
+                s = extract_nsec_multiplier(p + strspn(p, WHITESPACE), &multiplier);
+                if (s == p && *s != '\0')
+                        /* Don't allow '12.34.56', but accept '12.34 .56' or '12.34s.56'*/
+                        return -EINVAL;
+
+                p = s;
+
+                if ((nsec_t) l >= NSEC_INFINITY / multiplier)
+                        return -ERANGE;
+
+                k = (nsec_t) l * multiplier;
+                if (k >= NSEC_INFINITY - r)
+                        return -ERANGE;
+
+                r += k;
+
+                something = true;
+
+                if (*e == '.') {
+                        nsec_t m = multiplier / 10;
+                        const char *b;
+
+                        for (b = e + 1; *b >= '0' && *b <= '9'; b++, m /= 10) {
+                                k = (nsec_t) (*b - '0') * m;
+                                if (k >= NSEC_INFINITY - r)
+                                        return -ERANGE;
+
+                                r += k;
+                        }
+
+                        /* Don't allow "0.-0", "3.+1", "3. 1", "3.sec" or "3.hoge"*/
+                        if (b == e + 1)
+                                return -EINVAL;
+                }
+        }
+
+        *nsec = r;
+
+        return 0;
+}
+
+bool ntp_synced(void) {
+        struct timex txc = {};
+
+        if (adjtimex(&txc) < 0)
+                return false;
+
+        if (txc.status & STA_UNSYNC)
+                return false;
+
+        return true;
+}
+
+int get_timezones(char ***ret) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_strv_free_ char **zones = NULL;
+        size_t n_zones = 0, n_allocated = 0;
+        int r;
+
+        assert(ret);
+
+        zones = strv_new("UTC");
+        if (!zones)
+                return -ENOMEM;
+
+        n_allocated = 2;
+        n_zones = 1;
+
+        f = fopen("/usr/share/zoneinfo/zone.tab", "re");
+        if (f) {
+                for (;;) {
+                        _cleanup_free_ char *line = NULL;
+                        char *p, *w;
+                        size_t k;
+
+                        r = read_line(f, LONG_LINE_MAX, &line);
+                        if (r < 0)
+                                return r;
+                        if (r == 0)
+                                break;
+
+                        p = strstrip(line);
+
+                        if (isempty(p) || *p == '#')
+                                continue;
+
+                        /* Skip over country code */
+                        p += strcspn(p, WHITESPACE);
+                        p += strspn(p, WHITESPACE);
+
+                        /* Skip over coordinates */
+                        p += strcspn(p, WHITESPACE);
+                        p += strspn(p, WHITESPACE);
+
+                        /* Found timezone name */
+                        k = strcspn(p, WHITESPACE);
+                        if (k <= 0)
+                                continue;
+
+                        w = strndup(p, k);
+                        if (!w)
+                                return -ENOMEM;
+
+                        if (!GREEDY_REALLOC(zones, n_allocated, n_zones + 2)) {
+                                free(w);
+                                return -ENOMEM;
+                        }
+
+                        zones[n_zones++] = w;
+                        zones[n_zones] = NULL;
+                }
+
+                strv_sort(zones);
+
+        } else if (errno != ENOENT)
+                return -errno;
+
+        *ret = TAKE_PTR(zones);
+
+        return 0;
+}
+
+bool timezone_is_valid(const char *name, int log_level) {
+        bool slash = false;
+        const char *p, *t;
+        _cleanup_close_ int fd = -1;
+        char buf[4];
+        int r;
+
+        if (isempty(name))
+                return false;
+
+        if (name[0] == '/')
+                return false;
+
+        for (p = name; *p; p++) {
+                if (!(*p >= '0' && *p <= '9') &&
+                    !(*p >= 'a' && *p <= 'z') &&
+                    !(*p >= 'A' && *p <= 'Z') &&
+                    !IN_SET(*p, '-', '_', '+', '/'))
+                        return false;
+
+                if (*p == '/') {
+
+                        if (slash)
+                                return false;
+
+                        slash = true;
+                } else
+                        slash = false;
+        }
+
+        if (slash)
+                return false;
+
+        if (p - name >= PATH_MAX)
+                return false;
+
+        t = strjoina("/usr/share/zoneinfo/", name);
+
+        fd = open(t, O_RDONLY|O_CLOEXEC);
+        if (fd < 0) {
+                log_full_errno(log_level, errno, "Failed to open timezone file '%s': %m", t);
+                return false;
+        }
+
+        r = fd_verify_regular(fd);
+        if (r < 0) {
+                log_full_errno(log_level, r, "Timezone file '%s' is not  a regular file: %m", t);
+                return false;
+        }
+
+        r = loop_read_exact(fd, buf, 4, false);
+        if (r < 0) {
+                log_full_errno(log_level, r, "Failed to read from timezone file '%s': %m", t);
+                return false;
+        }
+
+        /* Magic from tzfile(5) */
+        if (memcmp(buf, "TZif", 4) != 0) {
+                log_full(log_level, "Timezone file '%s' has wrong magic bytes", t);
+                return false;
+        }
+
+        return true;
+}
+
+bool clock_boottime_supported(void) {
+        static int supported = -1;
+
+        /* Note that this checks whether CLOCK_BOOTTIME is available in general as well as available for timerfds()! */
+
+        if (supported < 0) {
+                int fd;
+
+                fd = timerfd_create(CLOCK_BOOTTIME, TFD_NONBLOCK|TFD_CLOEXEC);
+                if (fd < 0)
+                        supported = false;
+                else {
+                        safe_close(fd);
+                        supported = true;
+                }
+        }
+
+        return supported;
+}
+
+clockid_t clock_boottime_or_monotonic(void) {
+        if (clock_boottime_supported())
+                return CLOCK_BOOTTIME;
+        else
+                return CLOCK_MONOTONIC;
+}
+
+bool clock_supported(clockid_t clock) {
+        struct timespec ts;
+
+        switch (clock) {
+
+        case CLOCK_MONOTONIC:
+        case CLOCK_REALTIME:
+                return true;
+
+        case CLOCK_BOOTTIME:
+                return clock_boottime_supported();
+
+        case CLOCK_BOOTTIME_ALARM:
+                if (!clock_boottime_supported())
+                        return false;
+
+                _fallthrough_;
+        default:
+                /* For everything else, check properly */
+                return clock_gettime(clock, &ts) >= 0;
+        }
+}
+
+int get_timezone(char **tz) {
+        _cleanup_free_ char *t = NULL;
+        const char *e;
+        char *z;
+        int r;
+
+        r = readlink_malloc("/etc/localtime", &t);
+        if (r < 0)
+                return r; /* returns EINVAL if not a symlink */
+
+        e = PATH_STARTSWITH_SET(t, "/usr/share/zoneinfo/", "../usr/share/zoneinfo/");
+        if (!e)
+                return -EINVAL;
+
+        if (!timezone_is_valid(e, LOG_DEBUG))
+                return -EINVAL;
+
+        z = strdup(e);
+        if (!z)
+                return -ENOMEM;
+
+        *tz = z;
+        return 0;
+}
+
+time_t mktime_or_timegm(struct tm *tm, bool utc) {
+        return utc ? timegm(tm) : mktime(tm);
+}
+
+struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc) {
+        return utc ? gmtime_r(t, tm) : localtime_r(t, tm);
+}
+
+unsigned long usec_to_jiffies(usec_t u) {
+        static thread_local unsigned long hz = 0;
+        long r;
+
+        if (hz == 0) {
+                r = sysconf(_SC_CLK_TCK);
+
+                assert(r > 0);
+                hz = r;
+        }
+
+        return DIV_ROUND_UP(u , USEC_PER_SEC / hz);
+}
+
+usec_t usec_shift_clock(usec_t x, clockid_t from, clockid_t to) {
+        usec_t a, b;
+
+        if (x == USEC_INFINITY)
+                return USEC_INFINITY;
+        if (map_clock_id(from) == map_clock_id(to))
+                return x;
+
+        a = now(from);
+        b = now(to);
+
+        if (x > a)
+                /* x lies in the future */
+                return usec_add(b, usec_sub_unsigned(x, a));
+        else
+                /* x lies in the past */
+                return usec_sub_unsigned(b, usec_sub_unsigned(a, x));
+}
+
+bool in_utc_timezone(void) {
+        tzset();
+
+        return timezone == 0 && daylight == 0;
+}
+
+int time_change_fd(void) {
+
+        /* We only care for the cancellation event, hence we set the timeout to the latest possible value. */
+        static const struct itimerspec its = {
+                .it_value.tv_sec = TIME_T_MAX,
+        };
+
+        _cleanup_close_ int fd;
+
+        assert_cc(sizeof(time_t) == sizeof(TIME_T_MAX));
+
+        /* Uses TFD_TIMER_CANCEL_ON_SET to get notifications whenever CLOCK_REALTIME makes a jump relative to
+         * CLOCK_MONOTONIC. */
+
+        fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        if (timerfd_settime(fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0)
+                return -errno;
+
+        return TAKE_FD(fd);
+}
diff --git a/src/basic/time-util.h b/src/basic/time-util.h
new file mode 100644
index 0000000..5316305
--- /dev/null
+++ b/src/basic/time-util.h
@@ -0,0 +1,179 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <time.h>
+
+typedef uint64_t usec_t;
+typedef uint64_t nsec_t;
+
+#define PRI_NSEC PRIu64
+#define PRI_USEC PRIu64
+#define NSEC_FMT "%" PRI_NSEC
+#define USEC_FMT "%" PRI_USEC
+
+#include "macro.h"
+
+typedef struct dual_timestamp {
+        usec_t realtime;
+        usec_t monotonic;
+} dual_timestamp;
+
+typedef struct triple_timestamp {
+        usec_t realtime;
+        usec_t monotonic;
+        usec_t boottime;
+} triple_timestamp;
+
+#define USEC_INFINITY ((usec_t) -1)
+#define NSEC_INFINITY ((nsec_t) -1)
+
+#define MSEC_PER_SEC  1000ULL
+#define USEC_PER_SEC  ((usec_t) 1000000ULL)
+#define USEC_PER_MSEC ((usec_t) 1000ULL)
+#define NSEC_PER_SEC  ((nsec_t) 1000000000ULL)
+#define NSEC_PER_MSEC ((nsec_t) 1000000ULL)
+#define NSEC_PER_USEC ((nsec_t) 1000ULL)
+
+#define USEC_PER_MINUTE ((usec_t) (60ULL*USEC_PER_SEC))
+#define NSEC_PER_MINUTE ((nsec_t) (60ULL*NSEC_PER_SEC))
+#define USEC_PER_HOUR ((usec_t) (60ULL*USEC_PER_MINUTE))
+#define NSEC_PER_HOUR ((nsec_t) (60ULL*NSEC_PER_MINUTE))
+#define USEC_PER_DAY ((usec_t) (24ULL*USEC_PER_HOUR))
+#define NSEC_PER_DAY ((nsec_t) (24ULL*NSEC_PER_HOUR))
+#define USEC_PER_WEEK ((usec_t) (7ULL*USEC_PER_DAY))
+#define NSEC_PER_WEEK ((nsec_t) (7ULL*NSEC_PER_DAY))
+#define USEC_PER_MONTH ((usec_t) (2629800ULL*USEC_PER_SEC))
+#define NSEC_PER_MONTH ((nsec_t) (2629800ULL*NSEC_PER_SEC))
+#define USEC_PER_YEAR ((usec_t) (31557600ULL*USEC_PER_SEC))
+#define NSEC_PER_YEAR ((nsec_t) (31557600ULL*NSEC_PER_SEC))
+
+/* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
+ * to 6. Let's rely on that. */
+#define FORMAT_TIMESTAMP_MAX (3+1+10+1+8+1+6+1+6+1)
+#define FORMAT_TIMESTAMP_WIDTH 28 /* when outputting, assume this width */
+#define FORMAT_TIMESTAMP_RELATIVE_MAX 256
+#define FORMAT_TIMESPAN_MAX 64
+
+#define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
+
+#define DUAL_TIMESTAMP_NULL ((struct dual_timestamp) {})
+#define TRIPLE_TIMESTAMP_NULL ((struct triple_timestamp) {})
+
+usec_t now(clockid_t clock);
+nsec_t now_nsec(clockid_t clock);
+
+dual_timestamp* dual_timestamp_get(dual_timestamp *ts);
+dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u);
+dual_timestamp* dual_timestamp_from_monotonic(dual_timestamp *ts, usec_t u);
+dual_timestamp* dual_timestamp_from_boottime_or_monotonic(dual_timestamp *ts, usec_t u);
+
+triple_timestamp* triple_timestamp_get(triple_timestamp *ts);
+triple_timestamp* triple_timestamp_from_realtime(triple_timestamp *ts, usec_t u);
+
+#define DUAL_TIMESTAMP_HAS_CLOCK(clock)                               \
+        IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC)
+
+#define TRIPLE_TIMESTAMP_HAS_CLOCK(clock)                               \
+        IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)
+
+static inline bool dual_timestamp_is_set(const dual_timestamp *ts) {
+        return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
+                (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY));
+}
+
+static inline bool triple_timestamp_is_set(const triple_timestamp *ts) {
+        return ((ts->realtime > 0 && ts->realtime != USEC_INFINITY) ||
+                (ts->monotonic > 0 && ts->monotonic != USEC_INFINITY) ||
+                (ts->boottime > 0 && ts->boottime != USEC_INFINITY));
+}
+
+usec_t triple_timestamp_by_clock(triple_timestamp *ts, clockid_t clock);
+
+usec_t timespec_load(const struct timespec *ts) _pure_;
+nsec_t timespec_load_nsec(const struct timespec *ts) _pure_;
+struct timespec *timespec_store(struct timespec *ts, usec_t u);
+
+usec_t timeval_load(const struct timeval *tv) _pure_;
+struct timeval *timeval_store(struct timeval *tv, usec_t u);
+
+char *format_timestamp(char *buf, size_t l, usec_t t);
+char *format_timestamp_utc(char *buf, size_t l, usec_t t);
+char *format_timestamp_us(char *buf, size_t l, usec_t t);
+char *format_timestamp_us_utc(char *buf, size_t l, usec_t t);
+char *format_timestamp_relative(char *buf, size_t l, usec_t t);
+char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy);
+
+int parse_timestamp(const char *t, usec_t *usec);
+
+int parse_sec(const char *t, usec_t *usec);
+int parse_sec_fix_0(const char *t, usec_t *usec);
+int parse_time(const char *t, usec_t *usec, usec_t default_unit);
+int parse_nsec(const char *t, nsec_t *nsec);
+
+bool ntp_synced(void);
+
+int get_timezones(char ***l);
+bool timezone_is_valid(const char *name, int log_level);
+
+bool clock_boottime_supported(void);
+bool clock_supported(clockid_t clock);
+clockid_t clock_boottime_or_monotonic(void);
+
+usec_t usec_shift_clock(usec_t, clockid_t from, clockid_t to);
+
+int get_timezone(char **timezone);
+
+time_t mktime_or_timegm(struct tm *tm, bool utc);
+struct tm *localtime_or_gmtime_r(const time_t *t, struct tm *tm, bool utc);
+
+unsigned long usec_to_jiffies(usec_t usec);
+
+bool in_utc_timezone(void);
+
+static inline usec_t usec_add(usec_t a, usec_t b) {
+        usec_t c;
+
+        /* Adds two time values, and makes sure USEC_INFINITY as input results as USEC_INFINITY in output, and doesn't
+         * overflow. */
+
+        c = a + b;
+        if (c < a || c < b) /* overflow check */
+                return USEC_INFINITY;
+
+        return c;
+}
+
+static inline usec_t usec_sub_unsigned(usec_t timestamp, usec_t delta) {
+
+        if (timestamp == USEC_INFINITY) /* Make sure infinity doesn't degrade */
+                return USEC_INFINITY;
+        if (timestamp < delta)
+                return 0;
+
+        return timestamp - delta;
+}
+
+static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
+        if (delta < 0)
+                return usec_add(timestamp, (usec_t) (-delta));
+        else
+                return usec_sub_unsigned(timestamp, (usec_t) delta);
+}
+
+#if SIZEOF_TIME_T == 8
+/* The last second we can format is 31. Dec 9999, 1s before midnight, because otherwise we'd enter 5 digit year
+ * territory. However, since we want to stay away from this in all timezones we take one day off. */
+#define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 253402214399000000)
+#elif SIZEOF_TIME_T == 4
+/* With a 32bit time_t we can't go beyond 2038... */
+#define USEC_TIMESTAMP_FORMATTABLE_MAX ((usec_t) 2147483647000000)
+#else
+#error "Yuck, time_t is neither 4 nor 8 bytes wide?"
+#endif
+
+int time_change_fd(void);
diff --git a/src/basic/tmpfile-util.c b/src/basic/tmpfile-util.c
new file mode 100644
index 0000000..bc92d6a
--- /dev/null
+++ b/src/basic/tmpfile-util.c
@@ -0,0 +1,330 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <sys/mman.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "hexdecoct.h"
+#include "macro.h"
+#include "memfd-util.h"
+#include "missing_fcntl.h"
+#include "missing_syscall.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "random-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "tmpfile-util.h"
+#include "umask-util.h"
+
+int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
+        FILE *f;
+        char *t;
+        int r, fd;
+
+        assert(path);
+        assert(_f);
+        assert(_temp_path);
+
+        r = tempfn_xxxxxx(path, NULL, &t);
+        if (r < 0)
+                return r;
+
+        fd = mkostemp_safe(t);
+        if (fd < 0) {
+                free(t);
+                return -errno;
+        }
+
+        f = fdopen(fd, "w");
+        if (!f) {
+                unlink_noerrno(t);
+                free(t);
+                safe_close(fd);
+                return -errno;
+        }
+
+        *_f = f;
+        *_temp_path = t;
+
+        return 0;
+}
+
+/* This is much like mkostemp() but is subject to umask(). */
+int mkostemp_safe(char *pattern) {
+        _cleanup_umask_ mode_t u = 0;
+        int fd;
+
+        assert(pattern);
+
+        u = umask(077);
+
+        fd = mkostemp(pattern, O_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        return fd;
+}
+
+int fmkostemp_safe(char *pattern, const char *mode, FILE **ret_f) {
+        int fd;
+        FILE *f;
+
+        fd = mkostemp_safe(pattern);
+        if (fd < 0)
+                return fd;
+
+        f = fdopen(fd, mode);
+        if (!f) {
+                safe_close(fd);
+                return -errno;
+        }
+
+        *ret_f = f;
+        return 0;
+}
+
+int tempfn_xxxxxx(const char *p, const char *extra, char **ret) {
+        const char *fn;
+        char *t;
+
+        assert(ret);
+
+        if (isempty(p))
+                return -EINVAL;
+        if (path_equal(p, "/"))
+                return -EINVAL;
+
+        /*
+         * Turns this:
+         *         /foo/bar/waldo
+         *
+         * Into this:
+         *         /foo/bar/.#<extra>waldoXXXXXX
+         */
+
+        fn = basename(p);
+        if (!filename_is_valid(fn))
+                return -EINVAL;
+
+        extra = strempty(extra);
+
+        t = new(char, strlen(p) + 2 + strlen(extra) + 6 + 1);
+        if (!t)
+                return -ENOMEM;
+
+        strcpy(stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn), "XXXXXX");
+
+        *ret = path_simplify(t, false);
+        return 0;
+}
+
+int tempfn_random(const char *p, const char *extra, char **ret) {
+        const char *fn;
+        char *t, *x;
+        uint64_t u;
+        unsigned i;
+
+        assert(ret);
+
+        if (isempty(p))
+                return -EINVAL;
+        if (path_equal(p, "/"))
+                return -EINVAL;
+
+        /*
+         * Turns this:
+         *         /foo/bar/waldo
+         *
+         * Into this:
+         *         /foo/bar/.#<extra>waldobaa2a261115984a9
+         */
+
+        fn = basename(p);
+        if (!filename_is_valid(fn))
+                return -EINVAL;
+
+        extra = strempty(extra);
+
+        t = new(char, strlen(p) + 2 + strlen(extra) + 16 + 1);
+        if (!t)
+                return -ENOMEM;
+
+        x = stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn);
+
+        u = random_u64();
+        for (i = 0; i < 16; i++) {
+                *(x++) = hexchar(u & 0xF);
+                u >>= 4;
+        }
+
+        *x = 0;
+
+        *ret = path_simplify(t, false);
+        return 0;
+}
+
+int tempfn_random_child(const char *p, const char *extra, char **ret) {
+        char *t, *x;
+        uint64_t u;
+        unsigned i;
+        int r;
+
+        assert(ret);
+
+        /* Turns this:
+         *         /foo/bar/waldo
+         * Into this:
+         *         /foo/bar/waldo/.#<extra>3c2b6219aa75d7d0
+         */
+
+        if (!p) {
+                r = tmp_dir(&p);
+                if (r < 0)
+                        return r;
+        }
+
+        extra = strempty(extra);
+
+        t = new(char, strlen(p) + 3 + strlen(extra) + 16 + 1);
+        if (!t)
+                return -ENOMEM;
+
+        if (isempty(p))
+                x = stpcpy(stpcpy(t, ".#"), extra);
+        else
+                x = stpcpy(stpcpy(stpcpy(t, p), "/.#"), extra);
+
+        u = random_u64();
+        for (i = 0; i < 16; i++) {
+                *(x++) = hexchar(u & 0xF);
+                u >>= 4;
+        }
+
+        *x = 0;
+
+        *ret = path_simplify(t, false);
+        return 0;
+}
+
+int open_tmpfile_unlinkable(const char *directory, int flags) {
+        char *p;
+        int fd, r;
+
+        if (!directory) {
+                r = tmp_dir(&directory);
+                if (r < 0)
+                        return r;
+        } else if (isempty(directory))
+                return -EINVAL;
+
+        /* Returns an unlinked temporary file that cannot be linked into the file system anymore */
+
+        /* Try O_TMPFILE first, if it is supported */
+        fd = open(directory, flags|O_TMPFILE|O_EXCL, S_IRUSR|S_IWUSR);
+        if (fd >= 0)
+                return fd;
+
+        /* Fall back to unguessable name + unlinking */
+        p = strjoina(directory, "/systemd-tmp-XXXXXX");
+
+        fd = mkostemp_safe(p);
+        if (fd < 0)
+                return fd;
+
+        (void) unlink(p);
+
+        return fd;
+}
+
+int open_tmpfile_linkable(const char *target, int flags, char **ret_path) {
+        _cleanup_free_ char *tmp = NULL;
+        int r, fd;
+
+        assert(target);
+        assert(ret_path);
+
+        /* Don't allow O_EXCL, as that has a special meaning for O_TMPFILE */
+        assert((flags & O_EXCL) == 0);
+
+        /* Creates a temporary file, that shall be renamed to "target" later. If possible, this uses O_TMPFILE – in
+         * which case "ret_path" will be returned as NULL. If not possible a the tempoary path name used is returned in
+         * "ret_path". Use link_tmpfile() below to rename the result after writing the file in full. */
+
+        fd = open_parent(target, O_TMPFILE|flags, 0640);
+        if (fd >= 0) {
+                *ret_path = NULL;
+                return fd;
+        }
+
+        log_debug_errno(fd, "Failed to use O_TMPFILE for %s: %m", target);
+
+        r = tempfn_random(target, NULL, &tmp);
+        if (r < 0)
+                return r;
+
+        fd = open(tmp, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|flags, 0640);
+        if (fd < 0)
+                return -errno;
+
+        *ret_path = TAKE_PTR(tmp);
+
+        return fd;
+}
+
+int link_tmpfile(int fd, const char *path, const char *target) {
+        int r;
+
+        assert(fd >= 0);
+        assert(target);
+
+        /* Moves a temporary file created with open_tmpfile() above into its final place. if "path" is NULL an fd
+         * created with O_TMPFILE is assumed, and linkat() is used. Otherwise it is assumed O_TMPFILE is not supported
+         * on the directory, and renameat2() is used instead.
+         *
+         * Note that in both cases we will not replace existing files. This is because linkat() does not support this
+         * operation currently (renameat2() does), and there is no nice way to emulate this. */
+
+        if (path) {
+                r = rename_noreplace(AT_FDCWD, path, AT_FDCWD, target);
+                if (r < 0)
+                        return r;
+        } else {
+                char proc_fd_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1];
+
+                xsprintf(proc_fd_path, "/proc/self/fd/%i", fd);
+
+                if (linkat(AT_FDCWD, proc_fd_path, AT_FDCWD, target, AT_SYMLINK_FOLLOW) < 0)
+                        return -errno;
+        }
+
+        return 0;
+}
+
+int mkdtemp_malloc(const char *template, char **ret) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        assert(ret);
+
+        if (template)
+                p = strdup(template);
+        else {
+                const char *tmp;
+
+                r = tmp_dir(&tmp);
+                if (r < 0)
+                        return r;
+
+                p = strjoin(tmp, "/XXXXXX");
+        }
+        if (!p)
+                return -ENOMEM;
+
+        if (!mkdtemp(p))
+                return -errno;
+
+        *ret = TAKE_PTR(p);
+        return 0;
+}
diff --git a/src/basic/tmpfile-util.h b/src/basic/tmpfile-util.h
new file mode 100644
index 0000000..802c85d
--- /dev/null
+++ b/src/basic/tmpfile-util.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdio.h>
+
+int fopen_temporary(const char *path, FILE **_f, char **_temp_path);
+int mkostemp_safe(char *pattern);
+int fmkostemp_safe(char *pattern, const char *mode, FILE**_f);
+
+int tempfn_xxxxxx(const char *p, const char *extra, char **ret);
+int tempfn_random(const char *p, const char *extra, char **ret);
+int tempfn_random_child(const char *p, const char *extra, char **ret);
+
+int open_tmpfile_unlinkable(const char *directory, int flags);
+int open_tmpfile_linkable(const char *target, int flags, char **ret_path);
+
+int link_tmpfile(int fd, const char *path, const char *target);
+
+int mkdtemp_malloc(const char *template, char **ret);
diff --git a/src/basic/umask-util.h b/src/basic/umask-util.h
new file mode 100644
index 0000000..e964292
--- /dev/null
+++ b/src/basic/umask-util.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "macro.h"
+
+static inline void umaskp(mode_t *u) {
+        umask(*u);
+}
+
+#define _cleanup_umask_ _cleanup_(umaskp)
+
+struct _umask_struct_ {
+        mode_t mask;
+        bool quit;
+};
+
+static inline void _reset_umask_(struct _umask_struct_ *s) {
+        umask(s->mask);
+};
+
+#define RUN_WITH_UMASK(mask)                                            \
+        for (_cleanup_(_reset_umask_) struct _umask_struct_ _saved_umask_ = { umask(mask), false }; \
+             !_saved_umask_.quit ;                                      \
+             _saved_umask_.quit = true)
diff --git a/src/basic/unaligned.h b/src/basic/unaligned.h
new file mode 100644
index 0000000..00c17f8
--- /dev/null
+++ b/src/basic/unaligned.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <endian.h>
+#include <stdint.h>
+
+/* BE */
+
+static inline uint16_t unaligned_read_be16(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint16_t x; } *u = _u;
+
+        return be16toh(u->x);
+}
+
+static inline uint32_t unaligned_read_be32(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint32_t x; } *u = _u;
+
+        return be32toh(u->x);
+}
+
+static inline uint64_t unaligned_read_be64(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint64_t x; } *u = _u;
+
+        return be64toh(u->x);
+}
+
+static inline void unaligned_write_be16(void *_u, uint16_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint16_t x; } *u = _u;
+
+        u->x = be16toh(a);
+}
+
+static inline void unaligned_write_be32(void *_u, uint32_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint32_t x; } *u = _u;
+
+        u->x = be32toh(a);
+}
+
+static inline void unaligned_write_be64(void *_u, uint64_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint64_t x; } *u = _u;
+
+        u->x = be64toh(a);
+}
+
+/* LE */
+
+static inline uint16_t unaligned_read_le16(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint16_t x; } *u = _u;
+
+        return le16toh(u->x);
+}
+
+static inline uint32_t unaligned_read_le32(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint32_t x; } *u = _u;
+
+        return le32toh(u->x);
+}
+
+static inline uint64_t unaligned_read_le64(const void *_u) {
+        const struct __attribute__((__packed__, __may_alias__)) { uint64_t x; } *u = _u;
+
+        return le64toh(u->x);
+}
+
+static inline void unaligned_write_le16(void *_u, uint16_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint16_t x; } *u = _u;
+
+        u->x = le16toh(a);
+}
+
+static inline void unaligned_write_le32(void *_u, uint32_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint32_t x; } *u = _u;
+
+        u->x = le32toh(a);
+}
+
+static inline void unaligned_write_le64(void *_u, uint64_t a) {
+        struct __attribute__((__packed__, __may_alias__)) { uint64_t x; } *u = _u;
+
+        u->x = le64toh(a);
+}
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define unaligned_read_ne16 unaligned_read_be16
+#define unaligned_read_ne32 unaligned_read_be32
+#define unaligned_read_ne64 unaligned_read_be64
+
+#define unaligned_write_ne16 unaligned_write_be16
+#define unaligned_write_ne32 unaligned_write_be32
+#define unaligned_write_ne64 unaligned_write_be64
+#else
+#define unaligned_read_ne16 unaligned_read_le16
+#define unaligned_read_ne32 unaligned_read_le32
+#define unaligned_read_ne64 unaligned_read_le64
+
+#define unaligned_write_ne16 unaligned_write_le16
+#define unaligned_write_ne32 unaligned_write_le32
+#define unaligned_write_ne64 unaligned_write_le64
+#endif
diff --git a/src/basic/unit-def.c b/src/basic/unit-def.c
new file mode 100644
index 0000000..245daab
--- /dev/null
+++ b/src/basic/unit-def.c
@@ -0,0 +1,273 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "alloc-util.h"
+#include "bus-label.h"
+#include "string-table.h"
+#include "unit-def.h"
+#include "unit-name.h"
+
+char *unit_dbus_path_from_name(const char *name) {
+        _cleanup_free_ char *e = NULL;
+
+        assert(name);
+
+        e = bus_label_escape(name);
+        if (!e)
+                return NULL;
+
+        return strappend("/org/freedesktop/systemd1/unit/", e);
+}
+
+int unit_name_from_dbus_path(const char *path, char **name) {
+        const char *e;
+        char *n;
+
+        e = startswith(path, "/org/freedesktop/systemd1/unit/");
+        if (!e)
+                return -EINVAL;
+
+        n = bus_label_unescape(e);
+        if (!n)
+                return -ENOMEM;
+
+        *name = n;
+        return 0;
+}
+
+const char* unit_dbus_interface_from_type(UnitType t) {
+
+        static const char *const table[_UNIT_TYPE_MAX] = {
+                [UNIT_SERVICE] = "org.freedesktop.systemd1.Service",
+                [UNIT_SOCKET] = "org.freedesktop.systemd1.Socket",
+                [UNIT_TARGET] = "org.freedesktop.systemd1.Target",
+                [UNIT_DEVICE] = "org.freedesktop.systemd1.Device",
+                [UNIT_MOUNT] = "org.freedesktop.systemd1.Mount",
+                [UNIT_AUTOMOUNT] = "org.freedesktop.systemd1.Automount",
+                [UNIT_SWAP] = "org.freedesktop.systemd1.Swap",
+                [UNIT_TIMER] = "org.freedesktop.systemd1.Timer",
+                [UNIT_PATH] = "org.freedesktop.systemd1.Path",
+                [UNIT_SLICE] = "org.freedesktop.systemd1.Slice",
+                [UNIT_SCOPE] = "org.freedesktop.systemd1.Scope",
+        };
+
+        if (t < 0)
+                return NULL;
+        if (t >= _UNIT_TYPE_MAX)
+                return NULL;
+
+        return table[t];
+}
+
+const char *unit_dbus_interface_from_name(const char *name) {
+        UnitType t;
+
+        t = unit_name_to_type(name);
+        if (t < 0)
+                return NULL;
+
+        return unit_dbus_interface_from_type(t);
+}
+
+static const char* const unit_type_table[_UNIT_TYPE_MAX] = {
+        [UNIT_SERVICE] = "service",
+        [UNIT_SOCKET] = "socket",
+        [UNIT_TARGET] = "target",
+        [UNIT_DEVICE] = "device",
+        [UNIT_MOUNT] = "mount",
+        [UNIT_AUTOMOUNT] = "automount",
+        [UNIT_SWAP] = "swap",
+        [UNIT_TIMER] = "timer",
+        [UNIT_PATH] = "path",
+        [UNIT_SLICE] = "slice",
+        [UNIT_SCOPE] = "scope",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(unit_type, UnitType);
+
+static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
+        [UNIT_STUB] = "stub",
+        [UNIT_LOADED] = "loaded",
+        [UNIT_NOT_FOUND] = "not-found",
+        [UNIT_BAD_SETTING] = "bad-setting",
+        [UNIT_ERROR] = "error",
+        [UNIT_MERGED] = "merged",
+        [UNIT_MASKED] = "masked"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
+
+static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
+        [UNIT_ACTIVE] = "active",
+        [UNIT_RELOADING] = "reloading",
+        [UNIT_INACTIVE] = "inactive",
+        [UNIT_FAILED] = "failed",
+        [UNIT_ACTIVATING] = "activating",
+        [UNIT_DEACTIVATING] = "deactivating"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
+
+static const char* const automount_state_table[_AUTOMOUNT_STATE_MAX] = {
+        [AUTOMOUNT_DEAD] = "dead",
+        [AUTOMOUNT_WAITING] = "waiting",
+        [AUTOMOUNT_RUNNING] = "running",
+        [AUTOMOUNT_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(automount_state, AutomountState);
+
+static const char* const device_state_table[_DEVICE_STATE_MAX] = {
+        [DEVICE_DEAD] = "dead",
+        [DEVICE_TENTATIVE] = "tentative",
+        [DEVICE_PLUGGED] = "plugged",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
+
+static const char* const mount_state_table[_MOUNT_STATE_MAX] = {
+        [MOUNT_DEAD] = "dead",
+        [MOUNT_MOUNTING] = "mounting",
+        [MOUNT_MOUNTING_DONE] = "mounting-done",
+        [MOUNT_MOUNTED] = "mounted",
+        [MOUNT_REMOUNTING] = "remounting",
+        [MOUNT_UNMOUNTING] = "unmounting",
+        [MOUNT_REMOUNTING_SIGTERM] = "remounting-sigterm",
+        [MOUNT_REMOUNTING_SIGKILL] = "remounting-sigkill",
+        [MOUNT_UNMOUNTING_SIGTERM] = "unmounting-sigterm",
+        [MOUNT_UNMOUNTING_SIGKILL] = "unmounting-sigkill",
+        [MOUNT_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(mount_state, MountState);
+
+static const char* const path_state_table[_PATH_STATE_MAX] = {
+        [PATH_DEAD] = "dead",
+        [PATH_WAITING] = "waiting",
+        [PATH_RUNNING] = "running",
+        [PATH_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(path_state, PathState);
+
+static const char* const scope_state_table[_SCOPE_STATE_MAX] = {
+        [SCOPE_DEAD] = "dead",
+        [SCOPE_RUNNING] = "running",
+        [SCOPE_ABANDONED] = "abandoned",
+        [SCOPE_STOP_SIGTERM] = "stop-sigterm",
+        [SCOPE_STOP_SIGKILL] = "stop-sigkill",
+        [SCOPE_FAILED] = "failed",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(scope_state, ScopeState);
+
+static const char* const service_state_table[_SERVICE_STATE_MAX] = {
+        [SERVICE_DEAD] = "dead",
+        [SERVICE_START_PRE] = "start-pre",
+        [SERVICE_START] = "start",
+        [SERVICE_START_POST] = "start-post",
+        [SERVICE_RUNNING] = "running",
+        [SERVICE_EXITED] = "exited",
+        [SERVICE_RELOAD] = "reload",
+        [SERVICE_STOP] = "stop",
+        [SERVICE_STOP_WATCHDOG] = "stop-watchdog",
+        [SERVICE_STOP_SIGTERM] = "stop-sigterm",
+        [SERVICE_STOP_SIGKILL] = "stop-sigkill",
+        [SERVICE_STOP_POST] = "stop-post",
+        [SERVICE_FINAL_SIGTERM] = "final-sigterm",
+        [SERVICE_FINAL_SIGKILL] = "final-sigkill",
+        [SERVICE_FAILED] = "failed",
+        [SERVICE_AUTO_RESTART] = "auto-restart",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(service_state, ServiceState);
+
+static const char* const slice_state_table[_SLICE_STATE_MAX] = {
+        [SLICE_DEAD] = "dead",
+        [SLICE_ACTIVE] = "active"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(slice_state, SliceState);
+
+static const char* const socket_state_table[_SOCKET_STATE_MAX] = {
+        [SOCKET_DEAD] = "dead",
+        [SOCKET_START_PRE] = "start-pre",
+        [SOCKET_START_CHOWN] = "start-chown",
+        [SOCKET_START_POST] = "start-post",
+        [SOCKET_LISTENING] = "listening",
+        [SOCKET_RUNNING] = "running",
+        [SOCKET_STOP_PRE] = "stop-pre",
+        [SOCKET_STOP_PRE_SIGTERM] = "stop-pre-sigterm",
+        [SOCKET_STOP_PRE_SIGKILL] = "stop-pre-sigkill",
+        [SOCKET_STOP_POST] = "stop-post",
+        [SOCKET_FINAL_SIGTERM] = "final-sigterm",
+        [SOCKET_FINAL_SIGKILL] = "final-sigkill",
+        [SOCKET_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(socket_state, SocketState);
+
+static const char* const swap_state_table[_SWAP_STATE_MAX] = {
+        [SWAP_DEAD] = "dead",
+        [SWAP_ACTIVATING] = "activating",
+        [SWAP_ACTIVATING_DONE] = "activating-done",
+        [SWAP_ACTIVE] = "active",
+        [SWAP_DEACTIVATING] = "deactivating",
+        [SWAP_DEACTIVATING_SIGTERM] = "deactivating-sigterm",
+        [SWAP_DEACTIVATING_SIGKILL] = "deactivating-sigkill",
+        [SWAP_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(swap_state, SwapState);
+
+static const char* const target_state_table[_TARGET_STATE_MAX] = {
+        [TARGET_DEAD] = "dead",
+        [TARGET_ACTIVE] = "active"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(target_state, TargetState);
+
+static const char* const timer_state_table[_TIMER_STATE_MAX] = {
+        [TIMER_DEAD] = "dead",
+        [TIMER_WAITING] = "waiting",
+        [TIMER_RUNNING] = "running",
+        [TIMER_ELAPSED] = "elapsed",
+        [TIMER_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
+
+static const char* const unit_dependency_table[_UNIT_DEPENDENCY_MAX] = {
+        [UNIT_REQUIRES] = "Requires",
+        [UNIT_REQUISITE] = "Requisite",
+        [UNIT_WANTS] = "Wants",
+        [UNIT_BINDS_TO] = "BindsTo",
+        [UNIT_PART_OF] = "PartOf",
+        [UNIT_REQUIRED_BY] = "RequiredBy",
+        [UNIT_REQUISITE_OF] = "RequisiteOf",
+        [UNIT_WANTED_BY] = "WantedBy",
+        [UNIT_BOUND_BY] = "BoundBy",
+        [UNIT_CONSISTS_OF] = "ConsistsOf",
+        [UNIT_CONFLICTS] = "Conflicts",
+        [UNIT_CONFLICTED_BY] = "ConflictedBy",
+        [UNIT_BEFORE] = "Before",
+        [UNIT_AFTER] = "After",
+        [UNIT_ON_FAILURE] = "OnFailure",
+        [UNIT_TRIGGERS] = "Triggers",
+        [UNIT_TRIGGERED_BY] = "TriggeredBy",
+        [UNIT_PROPAGATES_RELOAD_TO] = "PropagatesReloadTo",
+        [UNIT_RELOAD_PROPAGATED_FROM] = "ReloadPropagatedFrom",
+        [UNIT_JOINS_NAMESPACE_OF] = "JoinsNamespaceOf",
+        [UNIT_REFERENCES] = "References",
+        [UNIT_REFERENCED_BY] = "ReferencedBy",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(unit_dependency, UnitDependency);
+
+static const char* const notify_access_table[_NOTIFY_ACCESS_MAX] = {
+        [NOTIFY_NONE] = "none",
+        [NOTIFY_MAIN] = "main",
+        [NOTIFY_EXEC] = "exec",
+        [NOTIFY_ALL] = "all"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(notify_access, NotifyAccess);
diff --git a/src/basic/unit-def.h b/src/basic/unit-def.h
new file mode 100644
index 0000000..85f3e42
--- /dev/null
+++ b/src/basic/unit-def.h
@@ -0,0 +1,284 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "macro.h"
+
+typedef enum UnitType {
+        UNIT_SERVICE = 0,
+        UNIT_SOCKET,
+        UNIT_TARGET,
+        UNIT_DEVICE,
+        UNIT_MOUNT,
+        UNIT_AUTOMOUNT,
+        UNIT_SWAP,
+        UNIT_TIMER,
+        UNIT_PATH,
+        UNIT_SLICE,
+        UNIT_SCOPE,
+        _UNIT_TYPE_MAX,
+        _UNIT_TYPE_INVALID = -1
+} UnitType;
+
+typedef enum UnitLoadState {
+        UNIT_STUB = 0,
+        UNIT_LOADED,
+        UNIT_NOT_FOUND,    /* error condition #1: unit file not found */
+        UNIT_BAD_SETTING,  /* error condition #2: we couldn't parse some essential unit file setting */
+        UNIT_ERROR,        /* error condition #3: other "system" error, catchall for the rest */
+        UNIT_MERGED,
+        UNIT_MASKED,
+        _UNIT_LOAD_STATE_MAX,
+        _UNIT_LOAD_STATE_INVALID = -1
+} UnitLoadState;
+
+typedef enum UnitActiveState {
+        UNIT_ACTIVE,
+        UNIT_RELOADING,
+        UNIT_INACTIVE,
+        UNIT_FAILED,
+        UNIT_ACTIVATING,
+        UNIT_DEACTIVATING,
+        _UNIT_ACTIVE_STATE_MAX,
+        _UNIT_ACTIVE_STATE_INVALID = -1
+} UnitActiveState;
+
+typedef enum AutomountState {
+        AUTOMOUNT_DEAD,
+        AUTOMOUNT_WAITING,
+        AUTOMOUNT_RUNNING,
+        AUTOMOUNT_FAILED,
+        _AUTOMOUNT_STATE_MAX,
+        _AUTOMOUNT_STATE_INVALID = -1
+} AutomountState;
+
+/* We simply watch devices, we cannot plug/unplug them. That
+ * simplifies the state engine greatly */
+typedef enum DeviceState {
+        DEVICE_DEAD,
+        DEVICE_TENTATIVE, /* mounted or swapped, but not (yet) announced by udev */
+        DEVICE_PLUGGED,   /* announced by udev */
+        _DEVICE_STATE_MAX,
+        _DEVICE_STATE_INVALID = -1
+} DeviceState;
+
+typedef enum MountState {
+        MOUNT_DEAD,
+        MOUNT_MOUNTING,               /* /usr/bin/mount is running, but the mount is not done yet. */
+        MOUNT_MOUNTING_DONE,          /* /usr/bin/mount is running, and the mount is done. */
+        MOUNT_MOUNTED,
+        MOUNT_REMOUNTING,
+        MOUNT_UNMOUNTING,
+        MOUNT_REMOUNTING_SIGTERM,
+        MOUNT_REMOUNTING_SIGKILL,
+        MOUNT_UNMOUNTING_SIGTERM,
+        MOUNT_UNMOUNTING_SIGKILL,
+        MOUNT_FAILED,
+        _MOUNT_STATE_MAX,
+        _MOUNT_STATE_INVALID = -1
+} MountState;
+
+typedef enum PathState {
+        PATH_DEAD,
+        PATH_WAITING,
+        PATH_RUNNING,
+        PATH_FAILED,
+        _PATH_STATE_MAX,
+        _PATH_STATE_INVALID = -1
+} PathState;
+
+typedef enum ScopeState {
+        SCOPE_DEAD,
+        SCOPE_RUNNING,
+        SCOPE_ABANDONED,
+        SCOPE_STOP_SIGTERM,
+        SCOPE_STOP_SIGKILL,
+        SCOPE_FAILED,
+        _SCOPE_STATE_MAX,
+        _SCOPE_STATE_INVALID = -1
+} ScopeState;
+
+typedef enum ServiceState {
+        SERVICE_DEAD,
+        SERVICE_START_PRE,
+        SERVICE_START,
+        SERVICE_START_POST,
+        SERVICE_RUNNING,
+        SERVICE_EXITED,            /* Nothing is running anymore, but RemainAfterExit is true hence this is OK */
+        SERVICE_RELOAD,
+        SERVICE_STOP,              /* No STOP_PRE state, instead just register multiple STOP executables */
+        SERVICE_STOP_WATCHDOG,
+        SERVICE_STOP_SIGTERM,
+        SERVICE_STOP_SIGKILL,
+        SERVICE_STOP_POST,
+        SERVICE_FINAL_SIGTERM,     /* In case the STOP_POST executable hangs, we shoot that down, too */
+        SERVICE_FINAL_SIGKILL,
+        SERVICE_FAILED,
+        SERVICE_AUTO_RESTART,
+        _SERVICE_STATE_MAX,
+        _SERVICE_STATE_INVALID = -1
+} ServiceState;
+
+typedef enum SliceState {
+        SLICE_DEAD,
+        SLICE_ACTIVE,
+        _SLICE_STATE_MAX,
+        _SLICE_STATE_INVALID = -1
+} SliceState;
+
+typedef enum SocketState {
+        SOCKET_DEAD,
+        SOCKET_START_PRE,
+        SOCKET_START_CHOWN,
+        SOCKET_START_POST,
+        SOCKET_LISTENING,
+        SOCKET_RUNNING,
+        SOCKET_STOP_PRE,
+        SOCKET_STOP_PRE_SIGTERM,
+        SOCKET_STOP_PRE_SIGKILL,
+        SOCKET_STOP_POST,
+        SOCKET_FINAL_SIGTERM,
+        SOCKET_FINAL_SIGKILL,
+        SOCKET_FAILED,
+        _SOCKET_STATE_MAX,
+        _SOCKET_STATE_INVALID = -1
+} SocketState;
+
+typedef enum SwapState {
+        SWAP_DEAD,
+        SWAP_ACTIVATING,               /* /sbin/swapon is running, but the swap not yet enabled. */
+        SWAP_ACTIVATING_DONE,          /* /sbin/swapon is running, and the swap is done. */
+        SWAP_ACTIVE,
+        SWAP_DEACTIVATING,
+        SWAP_DEACTIVATING_SIGTERM,
+        SWAP_DEACTIVATING_SIGKILL,
+        SWAP_FAILED,
+        _SWAP_STATE_MAX,
+        _SWAP_STATE_INVALID = -1
+} SwapState;
+
+typedef enum TargetState {
+        TARGET_DEAD,
+        TARGET_ACTIVE,
+        _TARGET_STATE_MAX,
+        _TARGET_STATE_INVALID = -1
+} TargetState;
+
+typedef enum TimerState {
+        TIMER_DEAD,
+        TIMER_WAITING,
+        TIMER_RUNNING,
+        TIMER_ELAPSED,
+        TIMER_FAILED,
+        _TIMER_STATE_MAX,
+        _TIMER_STATE_INVALID = -1
+} TimerState;
+
+typedef enum UnitDependency {
+        /* Positive dependencies */
+        UNIT_REQUIRES,
+        UNIT_REQUISITE,
+        UNIT_WANTS,
+        UNIT_BINDS_TO,
+        UNIT_PART_OF,
+
+        /* Inverse of the above */
+        UNIT_REQUIRED_BY,             /* inverse of 'requires' is 'required_by' */
+        UNIT_REQUISITE_OF,            /* inverse of 'requisite' is 'requisite_of' */
+        UNIT_WANTED_BY,               /* inverse of 'wants' */
+        UNIT_BOUND_BY,                /* inverse of 'binds_to' */
+        UNIT_CONSISTS_OF,             /* inverse of 'part_of' */
+
+        /* Negative dependencies */
+        UNIT_CONFLICTS,               /* inverse of 'conflicts' is 'conflicted_by' */
+        UNIT_CONFLICTED_BY,
+
+        /* Order */
+        UNIT_BEFORE,                  /* inverse of 'before' is 'after' and vice versa */
+        UNIT_AFTER,
+
+        /* On Failure */
+        UNIT_ON_FAILURE,
+
+        /* Triggers (i.e. a socket triggers a service) */
+        UNIT_TRIGGERS,
+        UNIT_TRIGGERED_BY,
+
+        /* Propagate reloads */
+        UNIT_PROPAGATES_RELOAD_TO,
+        UNIT_RELOAD_PROPAGATED_FROM,
+
+        /* Joins namespace of */
+        UNIT_JOINS_NAMESPACE_OF,
+
+        /* Reference information for GC logic */
+        UNIT_REFERENCES,              /* Inverse of 'references' is 'referenced_by' */
+        UNIT_REFERENCED_BY,
+
+        _UNIT_DEPENDENCY_MAX,
+        _UNIT_DEPENDENCY_INVALID = -1
+} UnitDependency;
+
+typedef enum NotifyAccess {
+        NOTIFY_NONE,
+        NOTIFY_ALL,
+        NOTIFY_MAIN,
+        NOTIFY_EXEC,
+        _NOTIFY_ACCESS_MAX,
+        _NOTIFY_ACCESS_INVALID = -1
+} NotifyAccess;
+
+char *unit_dbus_path_from_name(const char *name);
+int unit_name_from_dbus_path(const char *path, char **name);
+
+const char* unit_dbus_interface_from_type(UnitType t);
+const char *unit_dbus_interface_from_name(const char *name);
+
+const char *unit_type_to_string(UnitType i) _const_;
+UnitType unit_type_from_string(const char *s) _pure_;
+
+const char *unit_load_state_to_string(UnitLoadState i) _const_;
+UnitLoadState unit_load_state_from_string(const char *s) _pure_;
+
+const char *unit_active_state_to_string(UnitActiveState i) _const_;
+UnitActiveState unit_active_state_from_string(const char *s) _pure_;
+
+const char* automount_state_to_string(AutomountState i) _const_;
+AutomountState automount_state_from_string(const char *s) _pure_;
+
+const char* device_state_to_string(DeviceState i) _const_;
+DeviceState device_state_from_string(const char *s) _pure_;
+
+const char* mount_state_to_string(MountState i) _const_;
+MountState mount_state_from_string(const char *s) _pure_;
+
+const char* path_state_to_string(PathState i) _const_;
+PathState path_state_from_string(const char *s) _pure_;
+
+const char* scope_state_to_string(ScopeState i) _const_;
+ScopeState scope_state_from_string(const char *s) _pure_;
+
+const char* service_state_to_string(ServiceState i) _const_;
+ServiceState service_state_from_string(const char *s) _pure_;
+
+const char* slice_state_to_string(SliceState i) _const_;
+SliceState slice_state_from_string(const char *s) _pure_;
+
+const char* socket_state_to_string(SocketState i) _const_;
+SocketState socket_state_from_string(const char *s) _pure_;
+
+const char* swap_state_to_string(SwapState i) _const_;
+SwapState swap_state_from_string(const char *s) _pure_;
+
+const char* target_state_to_string(TargetState i) _const_;
+TargetState target_state_from_string(const char *s) _pure_;
+
+const char *timer_state_to_string(TimerState i) _const_;
+TimerState timer_state_from_string(const char *s) _pure_;
+
+const char *unit_dependency_to_string(UnitDependency i) _const_;
+UnitDependency unit_dependency_from_string(const char *s) _pure_;
+
+const char* notify_access_to_string(NotifyAccess i) _const_;
+NotifyAccess notify_access_from_string(const char *s) _pure_;
diff --git a/src/basic/unit-name.c b/src/basic/unit-name.c
new file mode 100644
index 0000000..1b81fe2
--- /dev/null
+++ b/src/basic/unit-name.c
@@ -0,0 +1,775 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "glob-util.h"
+#include "hexdecoct.h"
+#include "path-util.h"
+#include "special.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+
+/* Characters valid in a unit name. */
+#define VALID_CHARS                             \
+        DIGITS                                  \
+        LETTERS                                 \
+        ":-_.\\"
+
+/* The same, but also permits the single @ character that may appear */
+#define VALID_CHARS_WITH_AT                     \
+        "@"                                     \
+        VALID_CHARS
+
+/* All chars valid in a unit name glob */
+#define VALID_CHARS_GLOB                        \
+        VALID_CHARS_WITH_AT                     \
+        "[]!-*?"
+
+bool unit_name_is_valid(const char *n, UnitNameFlags flags) {
+        const char *e, *i, *at;
+
+        assert((flags & ~(UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE)) == 0);
+
+        if (_unlikely_(flags == 0))
+                return false;
+
+        if (isempty(n))
+                return false;
+
+        if (strlen(n) >= UNIT_NAME_MAX)
+                return false;
+
+        e = strrchr(n, '.');
+        if (!e || e == n)
+                return false;
+
+        if (unit_type_from_string(e + 1) < 0)
+                return false;
+
+        for (i = n, at = NULL; i < e; i++) {
+
+                if (*i == '@' && !at)
+                        at = i;
+
+                if (!strchr("@" VALID_CHARS, *i))
+                        return false;
+        }
+
+        if (at == n)
+                return false;
+
+        if (flags & UNIT_NAME_PLAIN)
+                if (!at)
+                        return true;
+
+        if (flags & UNIT_NAME_INSTANCE)
+                if (at && e > at + 1)
+                        return true;
+
+        if (flags & UNIT_NAME_TEMPLATE)
+                if (at && e == at + 1)
+                        return true;
+
+        return false;
+}
+
+bool unit_prefix_is_valid(const char *p) {
+
+        /* We don't allow additional @ in the prefix string */
+
+        if (isempty(p))
+                return false;
+
+        return in_charset(p, VALID_CHARS);
+}
+
+bool unit_instance_is_valid(const char *i) {
+
+        /* The max length depends on the length of the string, so we
+         * don't really check this here. */
+
+        if (isempty(i))
+                return false;
+
+        /* We allow additional @ in the instance string, we do not
+         * allow them in the prefix! */
+
+        return in_charset(i, "@" VALID_CHARS);
+}
+
+bool unit_suffix_is_valid(const char *s) {
+        if (isempty(s))
+                return false;
+
+        if (s[0] != '.')
+                return false;
+
+        if (unit_type_from_string(s + 1) < 0)
+                return false;
+
+        return true;
+}
+
+int unit_name_to_prefix(const char *n, char **ret) {
+        const char *p;
+        char *s;
+
+        assert(n);
+        assert(ret);
+
+        if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+                return -EINVAL;
+
+        p = strchr(n, '@');
+        if (!p)
+                p = strrchr(n, '.');
+
+        assert_se(p);
+
+        s = strndup(n, p - n);
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+int unit_name_to_instance(const char *n, char **instance) {
+        const char *p, *d;
+        char *i;
+
+        assert(n);
+        assert(instance);
+
+        if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+                return -EINVAL;
+
+        /* Everything past the first @ and before the last . is the instance */
+        p = strchr(n, '@');
+        if (!p) {
+                *instance = NULL;
+                return 0;
+        }
+
+        p++;
+
+        d = strrchr(p, '.');
+        if (!d)
+                return -EINVAL;
+
+        i = strndup(p, d-p);
+        if (!i)
+                return -ENOMEM;
+
+        *instance = i;
+        return 1;
+}
+
+int unit_name_to_prefix_and_instance(const char *n, char **ret) {
+        const char *d;
+        char *s;
+
+        assert(n);
+        assert(ret);
+
+        if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+                return -EINVAL;
+
+        d = strrchr(n, '.');
+        if (!d)
+                return -EINVAL;
+
+        s = strndup(n, d - n);
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+UnitType unit_name_to_type(const char *n) {
+        const char *e;
+
+        assert(n);
+
+        if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+                return _UNIT_TYPE_INVALID;
+
+        assert_se(e = strrchr(n, '.'));
+
+        return unit_type_from_string(e + 1);
+}
+
+int unit_name_change_suffix(const char *n, const char *suffix, char **ret) {
+        char *e, *s;
+        size_t a, b;
+
+        assert(n);
+        assert(suffix);
+        assert(ret);
+
+        if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+                return -EINVAL;
+
+        if (!unit_suffix_is_valid(suffix))
+                return -EINVAL;
+
+        assert_se(e = strrchr(n, '.'));
+
+        a = e - n;
+        b = strlen(suffix);
+
+        s = new(char, a + b + 1);
+        if (!s)
+                return -ENOMEM;
+
+        strcpy(mempcpy(s, n, a), suffix);
+        *ret = s;
+
+        return 0;
+}
+
+int unit_name_build(const char *prefix, const char *instance, const char *suffix, char **ret) {
+        UnitType type;
+
+        assert(prefix);
+        assert(suffix);
+        assert(ret);
+
+        if (suffix[0] != '.')
+                return -EINVAL;
+
+        type = unit_type_from_string(suffix + 1);
+        if (type < 0)
+                return -EINVAL;
+
+        return unit_name_build_from_type(prefix, instance, type, ret);
+}
+
+int unit_name_build_from_type(const char *prefix, const char *instance, UnitType type, char **ret) {
+        const char *ut;
+        char *s;
+
+        assert(prefix);
+        assert(type >= 0);
+        assert(type < _UNIT_TYPE_MAX);
+        assert(ret);
+
+        if (!unit_prefix_is_valid(prefix))
+                return -EINVAL;
+
+        if (instance && !unit_instance_is_valid(instance))
+                return -EINVAL;
+
+        ut = unit_type_to_string(type);
+
+        if (!instance)
+                s = strjoin(prefix, ".", ut);
+        else
+                s = strjoin(prefix, "@", instance, ".", ut);
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+static char *do_escape_char(char c, char *t) {
+        assert(t);
+
+        *(t++) = '\\';
+        *(t++) = 'x';
+        *(t++) = hexchar(c >> 4);
+        *(t++) = hexchar(c);
+
+        return t;
+}
+
+static char *do_escape(const char *f, char *t) {
+        assert(f);
+        assert(t);
+
+        /* do not create units with a leading '.', like for "/.dotdir" mount points */
+        if (*f == '.') {
+                t = do_escape_char(*f, t);
+                f++;
+        }
+
+        for (; *f; f++) {
+                if (*f == '/')
+                        *(t++) = '-';
+                else if (IN_SET(*f, '-', '\\') || !strchr(VALID_CHARS, *f))
+                        t = do_escape_char(*f, t);
+                else
+                        *(t++) = *f;
+        }
+
+        return t;
+}
+
+char *unit_name_escape(const char *f) {
+        char *r, *t;
+
+        assert(f);
+
+        r = new(char, strlen(f)*4+1);
+        if (!r)
+                return NULL;
+
+        t = do_escape(f, r);
+        *t = 0;
+
+        return r;
+}
+
+int unit_name_unescape(const char *f, char **ret) {
+        _cleanup_free_ char *r = NULL;
+        char *t;
+
+        assert(f);
+
+        r = strdup(f);
+        if (!r)
+                return -ENOMEM;
+
+        for (t = r; *f; f++) {
+                if (*f == '-')
+                        *(t++) = '/';
+                else if (*f == '\\') {
+                        int a, b;
+
+                        if (f[1] != 'x')
+                                return -EINVAL;
+
+                        a = unhexchar(f[2]);
+                        if (a < 0)
+                                return -EINVAL;
+
+                        b = unhexchar(f[3]);
+                        if (b < 0)
+                                return -EINVAL;
+
+                        *(t++) = (char) (((uint8_t) a << 4U) | (uint8_t) b);
+                        f += 3;
+                } else
+                        *(t++) = *f;
+        }
+
+        *t = 0;
+
+        *ret = TAKE_PTR(r);
+
+        return 0;
+}
+
+int unit_name_path_escape(const char *f, char **ret) {
+        char *p, *s;
+
+        assert(f);
+        assert(ret);
+
+        p = strdupa(f);
+        if (!p)
+                return -ENOMEM;
+
+        path_simplify(p, false);
+
+        if (empty_or_root(p))
+                s = strdup("-");
+        else {
+                if (!path_is_normalized(p))
+                        return -EINVAL;
+
+                /* Truncate trailing slashes */
+                delete_trailing_chars(p, "/");
+
+                /* Truncate leading slashes */
+                p = skip_leading_chars(p, "/");
+
+                s = unit_name_escape(p);
+        }
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+int unit_name_path_unescape(const char *f, char **ret) {
+        char *s;
+        int r;
+
+        assert(f);
+
+        if (isempty(f))
+                return -EINVAL;
+
+        if (streq(f, "-")) {
+                s = strdup("/");
+                if (!s)
+                        return -ENOMEM;
+        } else {
+                char *w;
+
+                r = unit_name_unescape(f, &w);
+                if (r < 0)
+                        return r;
+
+                /* Don't accept trailing or leading slashes */
+                if (startswith(w, "/") || endswith(w, "/")) {
+                        free(w);
+                        return -EINVAL;
+                }
+
+                /* Prefix a slash again */
+                s = strappend("/", w);
+                free(w);
+                if (!s)
+                        return -ENOMEM;
+
+                if (!path_is_normalized(s)) {
+                        free(s);
+                        return -EINVAL;
+                }
+        }
+
+        if (ret)
+                *ret = s;
+        else
+                free(s);
+
+        return 0;
+}
+
+int unit_name_replace_instance(const char *f, const char *i, char **ret) {
+        const char *p, *e;
+        char *s;
+        size_t a, b;
+
+        assert(f);
+        assert(i);
+        assert(ret);
+
+        if (!unit_name_is_valid(f, UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE))
+                return -EINVAL;
+        if (!unit_instance_is_valid(i))
+                return -EINVAL;
+
+        assert_se(p = strchr(f, '@'));
+        assert_se(e = strrchr(f, '.'));
+
+        a = p - f;
+        b = strlen(i);
+
+        s = new(char, a + 1 + b + strlen(e) + 1);
+        if (!s)
+                return -ENOMEM;
+
+        strcpy(mempcpy(mempcpy(s, f, a + 1), i, b), e);
+
+        *ret = s;
+        return 0;
+}
+
+int unit_name_template(const char *f, char **ret) {
+        const char *p, *e;
+        char *s;
+        size_t a;
+
+        assert(f);
+        assert(ret);
+
+        if (!unit_name_is_valid(f, UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE))
+                return -EINVAL;
+
+        assert_se(p = strchr(f, '@'));
+        assert_se(e = strrchr(f, '.'));
+
+        a = p - f;
+
+        s = new(char, a + 1 + strlen(e) + 1);
+        if (!s)
+                return -ENOMEM;
+
+        strcpy(mempcpy(s, f, a + 1), e);
+
+        *ret = s;
+        return 0;
+}
+
+int unit_name_from_path(const char *path, const char *suffix, char **ret) {
+        _cleanup_free_ char *p = NULL;
+        char *s = NULL;
+        int r;
+
+        assert(path);
+        assert(suffix);
+        assert(ret);
+
+        if (!unit_suffix_is_valid(suffix))
+                return -EINVAL;
+
+        r = unit_name_path_escape(path, &p);
+        if (r < 0)
+                return r;
+
+        s = strappend(p, suffix);
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+int unit_name_from_path_instance(const char *prefix, const char *path, const char *suffix, char **ret) {
+        _cleanup_free_ char *p = NULL;
+        char *s;
+        int r;
+
+        assert(prefix);
+        assert(path);
+        assert(suffix);
+        assert(ret);
+
+        if (!unit_prefix_is_valid(prefix))
+                return -EINVAL;
+
+        if (!unit_suffix_is_valid(suffix))
+                return -EINVAL;
+
+        r = unit_name_path_escape(path, &p);
+        if (r < 0)
+                return r;
+
+        s = strjoin(prefix, "@", p, suffix);
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+int unit_name_to_path(const char *name, char **ret) {
+        _cleanup_free_ char *prefix = NULL;
+        int r;
+
+        assert(name);
+
+        r = unit_name_to_prefix(name, &prefix);
+        if (r < 0)
+                return r;
+
+        return unit_name_path_unescape(prefix, ret);
+}
+
+static bool do_escape_mangle(const char *f, bool allow_globs, char *t) {
+        const char *valid_chars;
+        bool mangled = false;
+
+        assert(f);
+        assert(t);
+
+        /* We'll only escape the obvious characters here, to play safe.
+         *
+         * Returns true if any characters were mangled, false otherwise.
+         */
+
+        valid_chars = allow_globs ? VALID_CHARS_GLOB : VALID_CHARS_WITH_AT;
+
+        for (; *f; f++)
+                if (*f == '/') {
+                        *(t++) = '-';
+                        mangled = true;
+                } else if (!strchr(valid_chars, *f)) {
+                        t = do_escape_char(*f, t);
+                        mangled = true;
+                } else
+                        *(t++) = *f;
+        *t = 0;
+
+        return mangled;
+}
+
+/**
+ *  Convert a string to a unit name. /dev/blah is converted to dev-blah.device,
+ *  /blah/blah is converted to blah-blah.mount, anything else is left alone,
+ *  except that @suffix is appended if a valid unit suffix is not present.
+ *
+ *  If @allow_globs, globs characters are preserved. Otherwise, they are escaped.
+ */
+int unit_name_mangle_with_suffix(const char *name, UnitNameMangle flags, const char *suffix, char **ret) {
+        char *s;
+        int r;
+        bool mangled;
+
+        assert(name);
+        assert(suffix);
+        assert(ret);
+
+        if (isempty(name)) /* We cannot mangle empty unit names to become valid, sorry. */
+                return -EINVAL;
+
+        if (!unit_suffix_is_valid(suffix))
+                return -EINVAL;
+
+        /* Already a fully valid unit name? If so, no mangling is necessary... */
+        if (unit_name_is_valid(name, UNIT_NAME_ANY))
+                goto good;
+
+        /* Already a fully valid globbing expression? If so, no mangling is necessary either... */
+        if ((flags & UNIT_NAME_MANGLE_GLOB) &&
+            string_is_glob(name) &&
+            in_charset(name, VALID_CHARS_GLOB))
+                goto good;
+
+        if (is_device_path(name)) {
+                r = unit_name_from_path(name, ".device", ret);
+                if (r >= 0)
+                        return 1;
+                if (r != -EINVAL)
+                        return r;
+        }
+
+        if (path_is_absolute(name)) {
+                r = unit_name_from_path(name, ".mount", ret);
+                if (r >= 0)
+                        return 1;
+                if (r != -EINVAL)
+                        return r;
+        }
+
+        s = new(char, strlen(name) * 4 + strlen(suffix) + 1);
+        if (!s)
+                return -ENOMEM;
+
+        mangled = do_escape_mangle(name, flags & UNIT_NAME_MANGLE_GLOB, s);
+        if (mangled)
+                log_full(flags & UNIT_NAME_MANGLE_WARN ? LOG_NOTICE : LOG_DEBUG,
+                         "Invalid unit name \"%s\" was escaped as \"%s\" (maybe you should use systemd-escape?)",
+                         name, s);
+
+        /* Append a suffix if it doesn't have any, but only if this is not a glob, so that we can allow "foo.*" as a
+         * valid glob. */
+        if ((!(flags & UNIT_NAME_MANGLE_GLOB) || !string_is_glob(s)) && unit_name_to_type(s) < 0)
+                strcat(s, suffix);
+
+        *ret = s;
+        return 1;
+
+good:
+        s = strdup(name);
+        if (!s)
+                return -ENOMEM;
+
+        *ret = s;
+        return 0;
+}
+
+int slice_build_parent_slice(const char *slice, char **ret) {
+        char *s, *dash;
+        int r;
+
+        assert(slice);
+        assert(ret);
+
+        if (!slice_name_is_valid(slice))
+                return -EINVAL;
+
+        if (streq(slice, SPECIAL_ROOT_SLICE)) {
+                *ret = NULL;
+                return 0;
+        }
+
+        s = strdup(slice);
+        if (!s)
+                return -ENOMEM;
+
+        dash = strrchr(s, '-');
+        if (dash)
+                strcpy(dash, ".slice");
+        else {
+                r = free_and_strdup(&s, SPECIAL_ROOT_SLICE);
+                if (r < 0) {
+                        free(s);
+                        return r;
+                }
+        }
+
+        *ret = s;
+        return 1;
+}
+
+int slice_build_subslice(const char *slice, const char *name, char **ret) {
+        char *subslice;
+
+        assert(slice);
+        assert(name);
+        assert(ret);
+
+        if (!slice_name_is_valid(slice))
+                return -EINVAL;
+
+        if (!unit_prefix_is_valid(name))
+                return -EINVAL;
+
+        if (streq(slice, SPECIAL_ROOT_SLICE))
+                subslice = strappend(name, ".slice");
+        else {
+                char *e;
+
+                assert_se(e = endswith(slice, ".slice"));
+
+                subslice = new(char, (e - slice) + 1 + strlen(name) + 6 + 1);
+                if (!subslice)
+                        return -ENOMEM;
+
+                stpcpy(stpcpy(stpcpy(mempcpy(subslice, slice, e - slice), "-"), name), ".slice");
+        }
+
+        *ret = subslice;
+        return 0;
+}
+
+bool slice_name_is_valid(const char *name) {
+        const char *p, *e;
+        bool dash = false;
+
+        if (!unit_name_is_valid(name, UNIT_NAME_PLAIN))
+                return false;
+
+        if (streq(name, SPECIAL_ROOT_SLICE))
+                return true;
+
+        e = endswith(name, ".slice");
+        if (!e)
+                return false;
+
+        for (p = name; p < e; p++) {
+
+                if (*p == '-') {
+
+                        /* Don't allow initial dash */
+                        if (p == name)
+                                return false;
+
+                        /* Don't allow multiple dashes */
+                        if (dash)
+                                return false;
+
+                        dash = true;
+                } else
+                        dash = false;
+        }
+
+        /* Don't allow trailing hash */
+        if (dash)
+                return false;
+
+        return true;
+}
diff --git a/src/basic/unit-name.h b/src/basic/unit-name.h
new file mode 100644
index 0000000..0629db3
--- /dev/null
+++ b/src/basic/unit-name.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "macro.h"
+#include "unit-def.h"
+
+#define UNIT_NAME_MAX 256
+
+typedef enum UnitNameFlags {
+        UNIT_NAME_PLAIN    = 1 << 0, /* Allow foo.service */
+        UNIT_NAME_INSTANCE = 1 << 1, /* Allow foo@bar.service */
+        UNIT_NAME_TEMPLATE = 1 << 2, /* Allow foo@.service */
+        UNIT_NAME_ANY = UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE,
+} UnitNameFlags;
+
+bool unit_name_is_valid(const char *n, UnitNameFlags flags) _pure_;
+bool unit_prefix_is_valid(const char *p) _pure_;
+bool unit_instance_is_valid(const char *i) _pure_;
+bool unit_suffix_is_valid(const char *s) _pure_;
+
+static inline int unit_prefix_and_instance_is_valid(const char *p) {
+        /* For prefix+instance and instance the same rules apply */
+        return unit_instance_is_valid(p);
+}
+
+int unit_name_to_prefix(const char *n, char **prefix);
+int unit_name_to_instance(const char *n, char **instance);
+int unit_name_to_prefix_and_instance(const char *n, char **ret);
+
+UnitType unit_name_to_type(const char *n) _pure_;
+
+int unit_name_change_suffix(const char *n, const char *suffix, char **ret);
+
+int unit_name_build(const char *prefix, const char *instance, const char *suffix, char **ret);
+int unit_name_build_from_type(const char *prefix, const char *instance, UnitType, char **ret);
+
+char *unit_name_escape(const char *f);
+int unit_name_unescape(const char *f, char **ret);
+int unit_name_path_escape(const char *f, char **ret);
+int unit_name_path_unescape(const char *f, char **ret);
+
+int unit_name_replace_instance(const char *f, const char *i, char **ret);
+
+int unit_name_template(const char *f, char **ret);
+
+int unit_name_from_path(const char *path, const char *suffix, char **ret);
+int unit_name_from_path_instance(const char *prefix, const char *path, const char *suffix, char **ret);
+int unit_name_to_path(const char *name, char **ret);
+
+typedef enum UnitNameMangle {
+        UNIT_NAME_MANGLE_GLOB = 1 << 0,
+        UNIT_NAME_MANGLE_WARN = 1 << 1,
+} UnitNameMangle;
+
+int unit_name_mangle_with_suffix(const char *name, UnitNameMangle flags, const char *suffix, char **ret);
+
+static inline int unit_name_mangle(const char *name, UnitNameMangle flags, char **ret) {
+        return unit_name_mangle_with_suffix(name, flags, ".service", ret);
+}
+
+int slice_build_parent_slice(const char *slice, char **ret);
+int slice_build_subslice(const char *slice, const char *name, char **subslice);
+bool slice_name_is_valid(const char *name);
diff --git a/src/basic/user-util.c b/src/basic/user-util.c
new file mode 100644
index 0000000..260f3d2
--- /dev/null
+++ b/src/basic/user-util.c
@@ -0,0 +1,857 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <alloca.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <utmp.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "user-util.h"
+#include "utf8.h"
+
+bool uid_is_valid(uid_t uid) {
+
+        /* Also see POSIX IEEE Std 1003.1-2008, 2016 Edition, 3.436. */
+
+        /* Some libc APIs use UID_INVALID as special placeholder */
+        if (uid == (uid_t) UINT32_C(0xFFFFFFFF))
+                return false;
+
+        /* A long time ago UIDs where 16bit, hence explicitly avoid the 16bit -1 too */
+        if (uid == (uid_t) UINT32_C(0xFFFF))
+                return false;
+
+        return true;
+}
+
+int parse_uid(const char *s, uid_t *ret) {
+        uint32_t uid = 0;
+        int r;
+
+        assert(s);
+
+        assert_cc(sizeof(uid_t) == sizeof(uint32_t));
+        r = safe_atou32(s, &uid);
+        if (r < 0)
+                return r;
+
+        if (!uid_is_valid(uid))
+                return -ENXIO; /* we return ENXIO instead of EINVAL
+                                * here, to make it easy to distuingish
+                                * invalid numeric uids from invalid
+                                * strings. */
+
+        if (ret)
+                *ret = uid;
+
+        return 0;
+}
+
+char* getlogname_malloc(void) {
+        uid_t uid;
+        struct stat st;
+
+        if (isatty(STDIN_FILENO) && fstat(STDIN_FILENO, &st) >= 0)
+                uid = st.st_uid;
+        else
+                uid = getuid();
+
+        return uid_to_name(uid);
+}
+
+char *getusername_malloc(void) {
+        const char *e;
+
+        e = getenv("USER");
+        if (e)
+                return strdup(e);
+
+        return uid_to_name(getuid());
+}
+
+static bool is_nologin_shell(const char *shell) {
+
+        return PATH_IN_SET(shell,
+                           /* 'nologin' is the friendliest way to disable logins for a user account. It prints a nice
+                            * message and exits. Different distributions place the binary at different places though,
+                            * hence let's list them all. */
+                           "/bin/nologin",
+                           "/sbin/nologin",
+                           "/usr/bin/nologin",
+                           "/usr/sbin/nologin",
+                           /* 'true' and 'false' work too for the same purpose, but are less friendly as they don't do
+                            * any message printing. Different distributions place the binary at various places but at
+                            * least not in the 'sbin' directory. */
+                           "/bin/false",
+                           "/usr/bin/false",
+                           "/bin/true",
+                           "/usr/bin/true");
+}
+
+static int synthesize_user_creds(
+                const char **username,
+                uid_t *uid, gid_t *gid,
+                const char **home,
+                const char **shell,
+                UserCredsFlags flags) {
+
+        /* We enforce some special rules for uid=0 and uid=65534: in order to avoid NSS lookups for root we hardcode
+         * their user record data. */
+
+        if (STR_IN_SET(*username, "root", "0")) {
+                *username = "root";
+
+                if (uid)
+                        *uid = 0;
+                if (gid)
+                        *gid = 0;
+
+                if (home)
+                        *home = "/root";
+
+                if (shell)
+                        *shell = "/bin/sh";
+
+                return 0;
+        }
+
+        if (synthesize_nobody() &&
+            STR_IN_SET(*username, NOBODY_USER_NAME, "65534")) {
+                *username = NOBODY_USER_NAME;
+
+                if (uid)
+                        *uid = UID_NOBODY;
+                if (gid)
+                        *gid = GID_NOBODY;
+
+                if (home)
+                        *home = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : "/";
+
+                if (shell)
+                        *shell = FLAGS_SET(flags, USER_CREDS_CLEAN) ? NULL : "/sbin/nologin";
+
+                return 0;
+        }
+
+        return -ENOMEDIUM;
+}
+
+int get_user_creds(
+                const char **username,
+                uid_t *uid, gid_t *gid,
+                const char **home,
+                const char **shell,
+                UserCredsFlags flags) {
+
+        uid_t u = UID_INVALID;
+        struct passwd *p;
+        int r;
+
+        assert(username);
+        assert(*username);
+
+        if (!FLAGS_SET(flags, USER_CREDS_PREFER_NSS) ||
+            (!home && !shell)) {
+
+                /* So here's the deal: normally, we'll try to synthesize all records we can synthesize, and override
+                 * the user database with that. However, if the user specifies USER_CREDS_PREFER_NSS then the
+                 * user database will override the synthetic records instead — except if the user is only interested in
+                 * the UID and/or GID (but not the home directory, or the shell), in which case we'll always override
+                 * the user database (i.e. the USER_CREDS_PREFER_NSS flag has no effect in this case). Why?
+                 * Simply because there are valid usecase where the user might change the home directory or the shell
+                 * of the relevant users, but changing the UID/GID mappings for them is something we explicitly don't
+                 * support. */
+
+                r = synthesize_user_creds(username, uid, gid, home, shell, flags);
+                if (r >= 0)
+                        return 0;
+                if (r != -ENOMEDIUM) /* not a username we can synthesize */
+                        return r;
+        }
+
+        if (parse_uid(*username, &u) >= 0) {
+                errno = 0;
+                p = getpwuid(u);
+
+                /* If there are multiple users with the same id, make sure to leave $USER to the configured value
+                 * instead of the first occurrence in the database. However if the uid was configured by a numeric uid,
+                 * then let's pick the real username from /etc/passwd. */
+                if (p)
+                        *username = p->pw_name;
+                else if (FLAGS_SET(flags, USER_CREDS_ALLOW_MISSING) && !gid && !home && !shell) {
+
+                        /* If the specified user is a numeric UID and it isn't in the user database, and the caller
+                         * passed USER_CREDS_ALLOW_MISSING and was only interested in the UID, then juts return that
+                         * and don't complain. */
+
+                        if (uid)
+                                *uid = u;
+
+                        return 0;
+                }
+        } else {
+                errno = 0;
+                p = getpwnam(*username);
+        }
+        if (!p) {
+                r = errno > 0 ? -errno : -ESRCH;
+
+                /* If the user requested that we only synthesize as fallback, do so now */
+                if (FLAGS_SET(flags, USER_CREDS_PREFER_NSS)) {
+                        if (synthesize_user_creds(username, uid, gid, home, shell, flags) >= 0)
+                                return 0;
+                }
+
+                return r;
+        }
+
+        if (uid) {
+                if (!uid_is_valid(p->pw_uid))
+                        return -EBADMSG;
+
+                *uid = p->pw_uid;
+        }
+
+        if (gid) {
+                if (!gid_is_valid(p->pw_gid))
+                        return -EBADMSG;
+
+                *gid = p->pw_gid;
+        }
+
+        if (home) {
+                if (FLAGS_SET(flags, USER_CREDS_CLEAN) && empty_or_root(p->pw_dir))
+                        *home = NULL;
+                else
+                        *home = p->pw_dir;
+        }
+
+        if (shell) {
+                if (FLAGS_SET(flags, USER_CREDS_CLEAN) && (isempty(p->pw_shell) || is_nologin_shell(p->pw_shell)))
+                        *shell = NULL;
+                else
+                        *shell = p->pw_shell;
+        }
+
+        return 0;
+}
+
+int get_group_creds(const char **groupname, gid_t *gid, UserCredsFlags flags) {
+        struct group *g;
+        gid_t id;
+
+        assert(groupname);
+
+        /* We enforce some special rules for gid=0: in order to avoid NSS lookups for root we hardcode its data. */
+
+        if (STR_IN_SET(*groupname, "root", "0")) {
+                *groupname = "root";
+
+                if (gid)
+                        *gid = 0;
+
+                return 0;
+        }
+
+        if (synthesize_nobody() &&
+            STR_IN_SET(*groupname, NOBODY_GROUP_NAME, "65534")) {
+                *groupname = NOBODY_GROUP_NAME;
+
+                if (gid)
+                        *gid = GID_NOBODY;
+
+                return 0;
+        }
+
+        if (parse_gid(*groupname, &id) >= 0) {
+                errno = 0;
+                g = getgrgid(id);
+
+                if (g)
+                        *groupname = g->gr_name;
+                else if (FLAGS_SET(flags, USER_CREDS_ALLOW_MISSING)) {
+                        if (gid)
+                                *gid = id;
+
+                        return 0;
+                }
+        } else {
+                errno = 0;
+                g = getgrnam(*groupname);
+        }
+
+        if (!g)
+                return errno > 0 ? -errno : -ESRCH;
+
+        if (gid) {
+                if (!gid_is_valid(g->gr_gid))
+                        return -EBADMSG;
+
+                *gid = g->gr_gid;
+        }
+
+        return 0;
+}
+
+char* uid_to_name(uid_t uid) {
+        char *ret;
+        int r;
+
+        /* Shortcut things to avoid NSS lookups */
+        if (uid == 0)
+                return strdup("root");
+        if (synthesize_nobody() &&
+            uid == UID_NOBODY)
+                return strdup(NOBODY_USER_NAME);
+
+        if (uid_is_valid(uid)) {
+                long bufsize;
+
+                bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
+                if (bufsize <= 0)
+                        bufsize = 4096;
+
+                for (;;) {
+                        struct passwd pwbuf, *pw = NULL;
+                        _cleanup_free_ char *buf = NULL;
+
+                        buf = malloc(bufsize);
+                        if (!buf)
+                                return NULL;
+
+                        r = getpwuid_r(uid, &pwbuf, buf, (size_t) bufsize, &pw);
+                        if (r == 0 && pw)
+                                return strdup(pw->pw_name);
+                        if (r != ERANGE)
+                                break;
+
+                        bufsize *= 2;
+                }
+        }
+
+        if (asprintf(&ret, UID_FMT, uid) < 0)
+                return NULL;
+
+        return ret;
+}
+
+char* gid_to_name(gid_t gid) {
+        char *ret;
+        int r;
+
+        if (gid == 0)
+                return strdup("root");
+        if (synthesize_nobody() &&
+            gid == GID_NOBODY)
+                return strdup(NOBODY_GROUP_NAME);
+
+        if (gid_is_valid(gid)) {
+                long bufsize;
+
+                bufsize = sysconf(_SC_GETGR_R_SIZE_MAX);
+                if (bufsize <= 0)
+                        bufsize = 4096;
+
+                for (;;) {
+                        struct group grbuf, *gr = NULL;
+                        _cleanup_free_ char *buf = NULL;
+
+                        buf = malloc(bufsize);
+                        if (!buf)
+                                return NULL;
+
+                        r = getgrgid_r(gid, &grbuf, buf, (size_t) bufsize, &gr);
+                        if (r == 0 && gr)
+                                return strdup(gr->gr_name);
+                        if (r != ERANGE)
+                                break;
+
+                        bufsize *= 2;
+                }
+        }
+
+        if (asprintf(&ret, GID_FMT, gid) < 0)
+                return NULL;
+
+        return ret;
+}
+
+int in_gid(gid_t gid) {
+        long ngroups_max;
+        gid_t *gids;
+        int r, i;
+
+        if (getgid() == gid)
+                return 1;
+
+        if (getegid() == gid)
+                return 1;
+
+        if (!gid_is_valid(gid))
+                return -EINVAL;
+
+        ngroups_max = sysconf(_SC_NGROUPS_MAX);
+        assert(ngroups_max > 0);
+
+        gids = newa(gid_t, ngroups_max);
+
+        r = getgroups(ngroups_max, gids);
+        if (r < 0)
+                return -errno;
+
+        for (i = 0; i < r; i++)
+                if (gids[i] == gid)
+                        return 1;
+
+        return 0;
+}
+
+int in_group(const char *name) {
+        int r;
+        gid_t gid;
+
+        r = get_group_creds(&name, &gid, 0);
+        if (r < 0)
+                return r;
+
+        return in_gid(gid);
+}
+
+int get_home_dir(char **_h) {
+        struct passwd *p;
+        const char *e;
+        char *h;
+        uid_t u;
+
+        assert(_h);
+
+        /* Take the user specified one */
+        e = secure_getenv("HOME");
+        if (e && path_is_absolute(e)) {
+                h = strdup(e);
+                if (!h)
+                        return -ENOMEM;
+
+                *_h = h;
+                return 0;
+        }
+
+        /* Hardcode home directory for root and nobody to avoid NSS */
+        u = getuid();
+        if (u == 0) {
+                h = strdup("/root");
+                if (!h)
+                        return -ENOMEM;
+
+                *_h = h;
+                return 0;
+        }
+        if (synthesize_nobody() &&
+            u == UID_NOBODY) {
+                h = strdup("/");
+                if (!h)
+                        return -ENOMEM;
+
+                *_h = h;
+                return 0;
+        }
+
+        /* Check the database... */
+        errno = 0;
+        p = getpwuid(u);
+        if (!p)
+                return errno > 0 ? -errno : -ESRCH;
+
+        if (!path_is_absolute(p->pw_dir))
+                return -EINVAL;
+
+        h = strdup(p->pw_dir);
+        if (!h)
+                return -ENOMEM;
+
+        *_h = h;
+        return 0;
+}
+
+int get_shell(char **_s) {
+        struct passwd *p;
+        const char *e;
+        char *s;
+        uid_t u;
+
+        assert(_s);
+
+        /* Take the user specified one */
+        e = getenv("SHELL");
+        if (e) {
+                s = strdup(e);
+                if (!s)
+                        return -ENOMEM;
+
+                *_s = s;
+                return 0;
+        }
+
+        /* Hardcode shell for root and nobody to avoid NSS */
+        u = getuid();
+        if (u == 0) {
+                s = strdup("/bin/sh");
+                if (!s)
+                        return -ENOMEM;
+
+                *_s = s;
+                return 0;
+        }
+        if (synthesize_nobody() &&
+            u == UID_NOBODY) {
+                s = strdup("/sbin/nologin");
+                if (!s)
+                        return -ENOMEM;
+
+                *_s = s;
+                return 0;
+        }
+
+        /* Check the database... */
+        errno = 0;
+        p = getpwuid(u);
+        if (!p)
+                return errno > 0 ? -errno : -ESRCH;
+
+        if (!path_is_absolute(p->pw_shell))
+                return -EINVAL;
+
+        s = strdup(p->pw_shell);
+        if (!s)
+                return -ENOMEM;
+
+        *_s = s;
+        return 0;
+}
+
+int reset_uid_gid(void) {
+        int r;
+
+        r = maybe_setgroups(0, NULL);
+        if (r < 0)
+                return r;
+
+        if (setresgid(0, 0, 0) < 0)
+                return -errno;
+
+        if (setresuid(0, 0, 0) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int take_etc_passwd_lock(const char *root) {
+
+        struct flock flock = {
+                .l_type = F_WRLCK,
+                .l_whence = SEEK_SET,
+                .l_start = 0,
+                .l_len = 0,
+        };
+
+        const char *path;
+        int fd, r;
+
+        /* This is roughly the same as lckpwdf(), but not as awful. We
+         * don't want to use alarm() and signals, hence we implement
+         * our own trivial version of this.
+         *
+         * Note that shadow-utils also takes per-database locks in
+         * addition to lckpwdf(). However, we don't given that they
+         * are redundant as they invoke lckpwdf() first and keep
+         * it during everything they do. The per-database locks are
+         * awfully racy, and thus we just won't do them. */
+
+        if (root)
+                path = prefix_roota(root, ETC_PASSWD_LOCK_PATH);
+        else
+                path = ETC_PASSWD_LOCK_PATH;
+
+        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600);
+        if (fd < 0)
+                return log_debug_errno(errno, "Cannot open %s: %m", path);
+
+        r = fcntl(fd, F_SETLKW, &flock);
+        if (r < 0) {
+                safe_close(fd);
+                return log_debug_errno(errno, "Locking %s failed: %m", path);
+        }
+
+        return fd;
+}
+
+bool valid_user_group_name(const char *u) {
+        const char *i;
+        long sz;
+
+        /* Checks if the specified name is a valid user/group name. Also see POSIX IEEE Std 1003.1-2008, 2016 Edition,
+         * 3.437. We are a bit stricter here however. Specifically we deviate from POSIX rules:
+         *
+         * - We don't allow any dots (this would break chown syntax which permits dots as user/group name separator)
+         * - We require that names fit into the appropriate utmp field
+         * - We don't allow empty user names
+         *
+         * Note that other systems are even more restrictive, and don't permit underscores or uppercase characters.
+         */
+
+        if (isempty(u))
+                return false;
+
+        if (!(u[0] >= 'a' && u[0] <= 'z') &&
+            !(u[0] >= 'A' && u[0] <= 'Z') &&
+            u[0] != '_')
+                return false;
+
+        for (i = u+1; *i; i++) {
+                if (!(*i >= 'a' && *i <= 'z') &&
+                    !(*i >= 'A' && *i <= 'Z') &&
+                    !(*i >= '0' && *i <= '9') &&
+                    !IN_SET(*i, '_', '-'))
+                        return false;
+        }
+
+        sz = sysconf(_SC_LOGIN_NAME_MAX);
+        assert_se(sz > 0);
+
+        if ((size_t) (i-u) > (size_t) sz)
+                return false;
+
+        if ((size_t) (i-u) > UT_NAMESIZE - 1)
+                return false;
+
+        return true;
+}
+
+bool valid_user_group_name_or_id(const char *u) {
+
+        /* Similar as above, but is also fine with numeric UID/GID specifications, as long as they are in the right
+         * range, and not the invalid user ids. */
+
+        if (isempty(u))
+                return false;
+
+        if (valid_user_group_name(u))
+                return true;
+
+        return parse_uid(u, NULL) >= 0;
+}
+
+bool valid_gecos(const char *d) {
+
+        if (!d)
+                return false;
+
+        if (!utf8_is_valid(d))
+                return false;
+
+        if (string_has_cc(d, NULL))
+                return false;
+
+        /* Colons are used as field separators, and hence not OK */
+        if (strchr(d, ':'))
+                return false;
+
+        return true;
+}
+
+bool valid_home(const char *p) {
+        /* Note that this function is also called by valid_shell(), any
+         * changes must account for that. */
+
+        if (isempty(p))
+                return false;
+
+        if (!utf8_is_valid(p))
+                return false;
+
+        if (string_has_cc(p, NULL))
+                return false;
+
+        if (!path_is_absolute(p))
+                return false;
+
+        if (!path_is_normalized(p))
+                return false;
+
+        /* Colons are used as field separators, and hence not OK */
+        if (strchr(p, ':'))
+                return false;
+
+        return true;
+}
+
+int maybe_setgroups(size_t size, const gid_t *list) {
+        int r;
+
+        /* Check if setgroups is allowed before we try to drop all the auxiliary groups */
+        if (size == 0) { /* Dropping all aux groups? */
+                _cleanup_free_ char *setgroups_content = NULL;
+                bool can_setgroups;
+
+                r = read_one_line_file("/proc/self/setgroups", &setgroups_content);
+                if (r == -ENOENT)
+                        /* Old kernels don't have /proc/self/setgroups, so assume we can use setgroups */
+                        can_setgroups = true;
+                else if (r < 0)
+                        return r;
+                else
+                        can_setgroups = streq(setgroups_content, "allow");
+
+                if (!can_setgroups) {
+                        log_debug("Skipping setgroups(), /proc/self/setgroups is set to 'deny'");
+                        return 0;
+                }
+        }
+
+        if (setgroups(size, list) < 0)
+                return -errno;
+
+        return 0;
+}
+
+bool synthesize_nobody(void) {
+        /* Returns true when we shall synthesize the "nobody" user (which we do by default). This can be turned off by
+         * touching /etc/systemd/dont-synthesize-nobody in order to provide upgrade compatibility with legacy systems
+         * that used the "nobody" user name and group name for other UIDs/GIDs than 65534.
+         *
+         * Note that we do not employ any kind of synchronization on the following caching variable. If the variable is
+         * accessed in multi-threaded programs in the worst case it might happen that we initialize twice, but that
+         * shouldn't matter as each initialization should come to the same result. */
+        static int cache = -1;
+
+        if (cache < 0)
+                cache = access("/etc/systemd/dont-synthesize-nobody", F_OK) < 0;
+
+        return cache;
+}
+
+int putpwent_sane(const struct passwd *pw, FILE *stream) {
+        assert(pw);
+        assert(stream);
+
+        errno = 0;
+        if (putpwent(pw, stream) != 0)
+                return errno > 0 ? -errno : -EIO;
+
+        return 0;
+}
+
+int putspent_sane(const struct spwd *sp, FILE *stream) {
+        assert(sp);
+        assert(stream);
+
+        errno = 0;
+        if (putspent(sp, stream) != 0)
+                return errno > 0 ? -errno : -EIO;
+
+        return 0;
+}
+
+int putgrent_sane(const struct group *gr, FILE *stream) {
+        assert(gr);
+        assert(stream);
+
+        errno = 0;
+        if (putgrent(gr, stream) != 0)
+                return errno > 0 ? -errno : -EIO;
+
+        return 0;
+}
+
+#if ENABLE_GSHADOW
+int putsgent_sane(const struct sgrp *sg, FILE *stream) {
+        assert(sg);
+        assert(stream);
+
+        errno = 0;
+        if (putsgent(sg, stream) != 0)
+                return errno > 0 ? -errno : -EIO;
+
+        return 0;
+}
+#endif
+
+int fgetpwent_sane(FILE *stream, struct passwd **pw) {
+        struct passwd *p;
+
+        assert(pw);
+        assert(stream);
+
+        errno = 0;
+        p = fgetpwent(stream);
+        if (!p && errno != ENOENT)
+                return errno > 0 ? -errno : -EIO;
+
+        *pw = p;
+        return !!p;
+}
+
+int fgetspent_sane(FILE *stream, struct spwd **sp) {
+        struct spwd *s;
+
+        assert(sp);
+        assert(stream);
+
+        errno = 0;
+        s = fgetspent(stream);
+        if (!s && errno != ENOENT)
+                return errno > 0 ? -errno : -EIO;
+
+        *sp = s;
+        return !!s;
+}
+
+int fgetgrent_sane(FILE *stream, struct group **gr) {
+        struct group *g;
+
+        assert(gr);
+        assert(stream);
+
+        errno = 0;
+        g = fgetgrent(stream);
+        if (!g && errno != ENOENT)
+                return errno > 0 ? -errno : -EIO;
+
+        *gr = g;
+        return !!g;
+}
+
+#if ENABLE_GSHADOW
+int fgetsgent_sane(FILE *stream, struct sgrp **sg) {
+        struct sgrp *s;
+
+        assert(sg);
+        assert(stream);
+
+        errno = 0;
+        s = fgetsgent(stream);
+        if (!s && errno != ENOENT)
+                return errno > 0 ? -errno : -EIO;
+
+        *sg = s;
+        return !!s;
+}
+#endif
diff --git a/src/basic/user-util.h b/src/basic/user-util.h
new file mode 100644
index 0000000..cc899ee
--- /dev/null
+++ b/src/basic/user-util.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <grp.h>
+#if ENABLE_GSHADOW
+#include <gshadow.h>
+#endif
+#include <pwd.h>
+#include <shadow.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+bool uid_is_valid(uid_t uid);
+
+static inline bool gid_is_valid(gid_t gid) {
+        return uid_is_valid((uid_t) gid);
+}
+
+int parse_uid(const char *s, uid_t* ret_uid);
+
+static inline int parse_gid(const char *s, gid_t *ret_gid) {
+        return parse_uid(s, (uid_t*) ret_gid);
+}
+
+char* getlogname_malloc(void);
+char* getusername_malloc(void);
+
+typedef enum UserCredsFlags {
+        USER_CREDS_PREFER_NSS    = 1 << 0,  /* if set, only synthesize user records if database lacks them. Normally we bypass the userdb entirely for the records we can synthesize */
+        USER_CREDS_ALLOW_MISSING = 1 << 1,  /* if a numeric UID string is resolved, be OK if there's no record for it */
+        USER_CREDS_CLEAN         = 1 << 2,  /* try to clean up shell and home fields with invalid data */
+} UserCredsFlags;
+
+int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home, const char **shell, UserCredsFlags flags);
+int get_group_creds(const char **groupname, gid_t *gid, UserCredsFlags flags);
+
+char* uid_to_name(uid_t uid);
+char* gid_to_name(gid_t gid);
+
+int in_gid(gid_t gid);
+int in_group(const char *name);
+
+int get_home_dir(char **ret);
+int get_shell(char **_ret);
+
+int reset_uid_gid(void);
+
+int take_etc_passwd_lock(const char *root);
+
+#define UID_INVALID ((uid_t) -1)
+#define GID_INVALID ((gid_t) -1)
+
+#define UID_NOBODY ((uid_t) 65534U)
+#define GID_NOBODY ((gid_t) 65534U)
+
+#define ETC_PASSWD_LOCK_PATH "/etc/.pwd.lock"
+
+static inline bool uid_is_dynamic(uid_t uid) {
+        return DYNAMIC_UID_MIN <= uid && uid <= DYNAMIC_UID_MAX;
+}
+
+static inline bool gid_is_dynamic(gid_t gid) {
+        return uid_is_dynamic((uid_t) gid);
+}
+
+static inline bool uid_is_system(uid_t uid) {
+        return uid <= SYSTEM_UID_MAX;
+}
+
+static inline bool gid_is_system(gid_t gid) {
+        return gid <= SYSTEM_GID_MAX;
+}
+
+/* The following macros add 1 when converting things, since UID 0 is a valid UID, while the pointer
+ * NULL is special */
+#define PTR_TO_UID(p) ((uid_t) (((uintptr_t) (p))-1))
+#define UID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
+
+#define PTR_TO_GID(p) ((gid_t) (((uintptr_t) (p))-1))
+#define GID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
+
+static inline bool userns_supported(void) {
+        return access("/proc/self/uid_map", F_OK) >= 0;
+}
+
+bool valid_user_group_name(const char *u);
+bool valid_user_group_name_or_id(const char *u);
+bool valid_gecos(const char *d);
+bool valid_home(const char *p);
+
+static inline bool valid_shell(const char *p) {
+        /* We have the same requirements, so just piggy-back on the home check.
+         *
+         * Let's ignore /etc/shells because this is only applicable to real and
+         * not system users. It is also incompatible with the idea of empty /etc.
+         */
+        return valid_home(p);
+}
+
+int maybe_setgroups(size_t size, const gid_t *list);
+
+bool synthesize_nobody(void);
+
+int fgetpwent_sane(FILE *stream, struct passwd **pw);
+int fgetspent_sane(FILE *stream, struct spwd **sp);
+int fgetgrent_sane(FILE *stream, struct group **gr);
+int putpwent_sane(const struct passwd *pw, FILE *stream);
+int putspent_sane(const struct spwd *sp, FILE *stream);
+int putgrent_sane(const struct group *gr, FILE *stream);
+#if ENABLE_GSHADOW
+int fgetsgent_sane(FILE *stream, struct sgrp **sg);
+int putsgent_sane(const struct sgrp *sg, FILE *stream);
+#endif
diff --git a/src/basic/utf8.c b/src/basic/utf8.c
new file mode 100644
index 0000000..e0d1949
--- /dev/null
+++ b/src/basic/utf8.c
@@ -0,0 +1,532 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+/* Parts of this file are based on the GLIB utf8 validation functions. The
+ * original license text follows. */
+
+/* gutf8.c - Operations on UTF-8 strings.
+ *
+ * Copyright (C) 1999 Tom Tromey
+ * Copyright (C) 2000 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "gunicode.h"
+#include "hexdecoct.h"
+#include "macro.h"
+#include "utf8.h"
+
+bool unichar_is_valid(char32_t ch) {
+
+        if (ch >= 0x110000) /* End of unicode space */
+                return false;
+        if ((ch & 0xFFFFF800) == 0xD800) /* Reserved area for UTF-16 */
+                return false;
+        if ((ch >= 0xFDD0) && (ch <= 0xFDEF)) /* Reserved */
+                return false;
+        if ((ch & 0xFFFE) == 0xFFFE) /* BOM (Byte Order Mark) */
+                return false;
+
+        return true;
+}
+
+static bool unichar_is_control(char32_t ch) {
+
+        /*
+          0 to ' '-1 is the C0 range.
+          DEL=0x7F, and DEL+1 to 0x9F is C1 range.
+          '\t' is in C0 range, but more or less harmless and commonly used.
+        */
+
+        return (ch < ' ' && !IN_SET(ch, '\t', '\n')) ||
+                (0x7F <= ch && ch <= 0x9F);
+}
+
+/* count of characters used to encode one unicode char */
+static size_t utf8_encoded_expected_len(const char *str) {
+        uint8_t c;
+
+        assert(str);
+
+        c = (uint8_t) str[0];
+        if (c < 0x80)
+                return 1;
+        if ((c & 0xe0) == 0xc0)
+                return 2;
+        if ((c & 0xf0) == 0xe0)
+                return 3;
+        if ((c & 0xf8) == 0xf0)
+                return 4;
+        if ((c & 0xfc) == 0xf8)
+                return 5;
+        if ((c & 0xfe) == 0xfc)
+                return 6;
+
+        return 0;
+}
+
+/* decode one unicode char */
+int utf8_encoded_to_unichar(const char *str, char32_t *ret_unichar) {
+        char32_t unichar;
+        size_t len, i;
+
+        assert(str);
+
+        len = utf8_encoded_expected_len(str);
+
+        switch (len) {
+        case 1:
+                *ret_unichar = (char32_t)str[0];
+                return 0;
+        case 2:
+                unichar = str[0] & 0x1f;
+                break;
+        case 3:
+                unichar = (char32_t)str[0] & 0x0f;
+                break;
+        case 4:
+                unichar = (char32_t)str[0] & 0x07;
+                break;
+        case 5:
+                unichar = (char32_t)str[0] & 0x03;
+                break;
+        case 6:
+                unichar = (char32_t)str[0] & 0x01;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        for (i = 1; i < len; i++) {
+                if (((char32_t)str[i] & 0xc0) != 0x80)
+                        return -EINVAL;
+
+                unichar <<= 6;
+                unichar |= (char32_t)str[i] & 0x3f;
+        }
+
+        *ret_unichar = unichar;
+
+        return 0;
+}
+
+bool utf8_is_printable_newline(const char* str, size_t length, bool newline) {
+        const char *p;
+
+        assert(str);
+
+        for (p = str; length;) {
+                int encoded_len, r;
+                char32_t val;
+
+                encoded_len = utf8_encoded_valid_unichar(p);
+                if (encoded_len < 0 ||
+                    (size_t) encoded_len > length)
+                        return false;
+
+                r = utf8_encoded_to_unichar(p, &val);
+                if (r < 0 ||
+                    unichar_is_control(val) ||
+                    (!newline && val == '\n'))
+                        return false;
+
+                length -= encoded_len;
+                p += encoded_len;
+        }
+
+        return true;
+}
+
+char *utf8_is_valid(const char *str) {
+        const char *p;
+
+        assert(str);
+
+        p = str;
+        while (*p) {
+                int len;
+
+                len = utf8_encoded_valid_unichar(p);
+                if (len < 0)
+                        return NULL;
+
+                p += len;
+        }
+
+        return (char*) str;
+}
+
+char *utf8_escape_invalid(const char *str) {
+        char *p, *s;
+
+        assert(str);
+
+        p = s = malloc(strlen(str) * 4 + 1);
+        if (!p)
+                return NULL;
+
+        while (*str) {
+                int len;
+
+                len = utf8_encoded_valid_unichar(str);
+                if (len > 0) {
+                        s = mempcpy(s, str, len);
+                        str += len;
+                } else {
+                        s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER);
+                        str += 1;
+                }
+        }
+
+        *s = '\0';
+
+        return p;
+}
+
+char *utf8_escape_non_printable(const char *str) {
+        char *p, *s;
+
+        assert(str);
+
+        p = s = malloc(strlen(str) * 4 + 1);
+        if (!p)
+                return NULL;
+
+        while (*str) {
+                int len;
+
+                len = utf8_encoded_valid_unichar(str);
+                if (len > 0) {
+                        if (utf8_is_printable(str, len)) {
+                                s = mempcpy(s, str, len);
+                                str += len;
+                        } else {
+                                while (len > 0) {
+                                        *(s++) = '\\';
+                                        *(s++) = 'x';
+                                        *(s++) = hexchar((int) *str >> 4);
+                                        *(s++) = hexchar((int) *str);
+
+                                        str += 1;
+                                        len--;
+                                }
+                        }
+                } else {
+                        s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER);
+                        str += 1;
+                }
+        }
+
+        *s = '\0';
+
+        return p;
+}
+
+char *ascii_is_valid(const char *str) {
+        const char *p;
+
+        /* Check whether the string consists of valid ASCII bytes,
+         * i.e values between 0 and 127, inclusive. */
+
+        assert(str);
+
+        for (p = str; *p; p++)
+                if ((unsigned char) *p >= 128)
+                        return NULL;
+
+        return (char*) str;
+}
+
+char *ascii_is_valid_n(const char *str, size_t len) {
+        size_t i;
+
+        /* Very similar to ascii_is_valid(), but checks exactly len
+         * bytes and rejects any NULs in that range. */
+
+        assert(str);
+
+        for (i = 0; i < len; i++)
+                if ((unsigned char) str[i] >= 128 || str[i] == 0)
+                        return NULL;
+
+        return (char*) str;
+}
+
+/**
+ * utf8_encode_unichar() - Encode single UCS-4 character as UTF-8
+ * @out_utf8: output buffer of at least 4 bytes or NULL
+ * @g: UCS-4 character to encode
+ *
+ * This encodes a single UCS-4 character as UTF-8 and writes it into @out_utf8.
+ * The length of the character is returned. It is not zero-terminated! If the
+ * output buffer is NULL, only the length is returned.
+ *
+ * Returns: The length in bytes that the UTF-8 representation does or would
+ *          occupy.
+ */
+size_t utf8_encode_unichar(char *out_utf8, char32_t g) {
+
+        if (g < (1 << 7)) {
+                if (out_utf8)
+                        out_utf8[0] = g & 0x7f;
+                return 1;
+        } else if (g < (1 << 11)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xc0 | ((g >> 6) & 0x1f);
+                        out_utf8[1] = 0x80 | (g & 0x3f);
+                }
+                return 2;
+        } else if (g < (1 << 16)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xe0 | ((g >> 12) & 0x0f);
+                        out_utf8[1] = 0x80 | ((g >> 6) & 0x3f);
+                        out_utf8[2] = 0x80 | (g & 0x3f);
+                }
+                return 3;
+        } else if (g < (1 << 21)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xf0 | ((g >> 18) & 0x07);
+                        out_utf8[1] = 0x80 | ((g >> 12) & 0x3f);
+                        out_utf8[2] = 0x80 | ((g >> 6) & 0x3f);
+                        out_utf8[3] = 0x80 | (g & 0x3f);
+                }
+                return 4;
+        }
+
+        return 0;
+}
+
+char *utf16_to_utf8(const char16_t *s, size_t length /* bytes! */) {
+        const uint8_t *f;
+        char *r, *t;
+
+        assert(s);
+
+        /* Input length is in bytes, i.e. the shortest possible character takes 2 bytes. Each unicode character may
+         * take up to 4 bytes in UTF-8. Let's also account for a trailing NUL byte. */
+        if (length * 2 < length)
+                return NULL; /* overflow */
+
+        r = new(char, length * 2 + 1);
+        if (!r)
+                return NULL;
+
+        f = (const uint8_t*) s;
+        t = r;
+
+        while (f + 1 < (const uint8_t*) s + length) {
+                char16_t w1, w2;
+
+                /* see RFC 2781 section 2.2 */
+
+                w1 = f[1] << 8 | f[0];
+                f += 2;
+
+                if (!utf16_is_surrogate(w1)) {
+                        t += utf8_encode_unichar(t, w1);
+                        continue;
+                }
+
+                if (utf16_is_trailing_surrogate(w1))
+                        continue; /* spurious trailing surrogate, ignore */
+
+                if (f + 1 >= (const uint8_t*) s + length)
+                        break;
+
+                w2 = f[1] << 8 | f[0];
+                f += 2;
+
+                if (!utf16_is_trailing_surrogate(w2)) {
+                        f -= 2;
+                        continue; /* surrogate missing its trailing surrogate, ignore */
+                }
+
+                t += utf8_encode_unichar(t, utf16_surrogate_pair_to_unichar(w1, w2));
+        }
+
+        *t = 0;
+        return r;
+}
+
+size_t utf16_encode_unichar(char16_t *out, char32_t c) {
+
+        /* Note that this encodes as little-endian. */
+
+        switch (c) {
+
+        case 0 ... 0xd7ffU:
+        case 0xe000U ... 0xffffU:
+                out[0] = htole16(c);
+                return 1;
+
+        case 0x10000U ... 0x10ffffU:
+                c -= 0x10000U;
+                out[0] = htole16((c >> 10) + 0xd800U);
+                out[1] = htole16((c & 0x3ffU) + 0xdc00U);
+                return 2;
+
+        default: /* A surrogate (invalid) */
+                return 0;
+        }
+}
+
+char16_t *utf8_to_utf16(const char *s, size_t length) {
+        char16_t *n, *p;
+        size_t i;
+        int r;
+
+        assert(s);
+
+        n = new(char16_t, length + 1);
+        if (!n)
+                return NULL;
+
+        p = n;
+
+        for (i = 0; i < length;) {
+                char32_t unichar;
+                size_t e;
+
+                e = utf8_encoded_expected_len(s + i);
+                if (e <= 1) /* Invalid and single byte characters are copied as they are */
+                        goto copy;
+
+                if (i + e > length) /* sequence longer than input buffer, then copy as-is */
+                        goto copy;
+
+                r = utf8_encoded_to_unichar(s + i, &unichar);
+                if (r < 0) /* sequence invalid, then copy as-is */
+                        goto copy;
+
+                p += utf16_encode_unichar(p, unichar);
+                i += e;
+                continue;
+
+        copy:
+                *(p++) = htole16(s[i++]);
+        }
+
+        *p = 0;
+        return n;
+}
+
+size_t char16_strlen(const char16_t *s) {
+        size_t n = 0;
+
+        assert(s);
+
+        while (*s != 0)
+                n++, s++;
+
+        return n;
+}
+
+/* expected size used to encode one unicode char */
+static int utf8_unichar_to_encoded_len(char32_t unichar) {
+
+        if (unichar < 0x80)
+                return 1;
+        if (unichar < 0x800)
+                return 2;
+        if (unichar < 0x10000)
+                return 3;
+        if (unichar < 0x200000)
+                return 4;
+        if (unichar < 0x4000000)
+                return 5;
+
+        return 6;
+}
+
+/* validate one encoded unicode char and return its length */
+int utf8_encoded_valid_unichar(const char *str) {
+        char32_t unichar;
+        size_t len, i;
+        int r;
+
+        assert(str);
+
+        len = utf8_encoded_expected_len(str);
+        if (len == 0)
+                return -EINVAL;
+
+        /* ascii is valid */
+        if (len == 1)
+                return 1;
+
+        /* check if expected encoded chars are available */
+        for (i = 0; i < len; i++)
+                if ((str[i] & 0x80) != 0x80)
+                        return -EINVAL;
+
+        r = utf8_encoded_to_unichar(str, &unichar);
+        if (r < 0)
+                return r;
+
+        /* check if encoded length matches encoded value */
+        if (utf8_unichar_to_encoded_len(unichar) != (int) len)
+                return -EINVAL;
+
+        /* check if value has valid range */
+        if (!unichar_is_valid(unichar))
+                return -EINVAL;
+
+        return (int) len;
+}
+
+size_t utf8_n_codepoints(const char *str) {
+        size_t n = 0;
+
+        /* Returns the number of UTF-8 codepoints in this string, or (size_t) -1 if the string is not valid UTF-8. */
+
+        while (*str != 0) {
+                int k;
+
+                k = utf8_encoded_valid_unichar(str);
+                if (k < 0)
+                        return (size_t) -1;
+
+                str += k;
+                n++;
+        }
+
+        return n;
+}
+
+size_t utf8_console_width(const char *str) {
+        size_t n = 0;
+
+        /* Returns the approximate width a string will take on screen when printed on a character cell
+         * terminal/console. */
+
+        while (*str != 0) {
+                char32_t c;
+
+                if (utf8_encoded_to_unichar(str, &c) < 0)
+                        return (size_t) -1;
+
+                str = utf8_next_char(str);
+
+                n += unichar_iswide(c) ? 2 : 1;
+        }
+
+        return n;
+}
diff --git a/src/basic/utf8.h b/src/basic/utf8.h
new file mode 100644
index 0000000..6284569
--- /dev/null
+++ b/src/basic/utf8.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <uchar.h>
+
+#include "macro.h"
+#include "missing_type.h"
+
+#define UTF8_REPLACEMENT_CHARACTER "\xef\xbf\xbd"
+#define UTF8_BYTE_ORDER_MARK "\xef\xbb\xbf"
+
+bool unichar_is_valid(char32_t c);
+
+char *utf8_is_valid(const char *s) _pure_;
+char *ascii_is_valid(const char *s) _pure_;
+char *ascii_is_valid_n(const char *str, size_t len);
+
+bool utf8_is_printable_newline(const char* str, size_t length, bool newline) _pure_;
+#define utf8_is_printable(str, length) utf8_is_printable_newline(str, length, true)
+
+char *utf8_escape_invalid(const char *s);
+char *utf8_escape_non_printable(const char *str);
+
+size_t utf8_encode_unichar(char *out_utf8, char32_t g);
+size_t utf16_encode_unichar(char16_t *out, char32_t c);
+
+char *utf16_to_utf8(const char16_t *s, size_t length /* bytes! */);
+char16_t *utf8_to_utf16(const char *s, size_t length);
+
+size_t char16_strlen(const char16_t *s); /* returns the number of 16bit words in the string (not bytes!) */
+
+int utf8_encoded_valid_unichar(const char *str);
+int utf8_encoded_to_unichar(const char *str, char32_t *ret_unichar);
+
+static inline bool utf16_is_surrogate(char16_t c) {
+        return c >= 0xd800U && c <= 0xdfffU;
+}
+
+static inline bool utf16_is_trailing_surrogate(char16_t c) {
+        return c >= 0xdc00U && c <= 0xdfffU;
+}
+
+static inline char32_t utf16_surrogate_pair_to_unichar(char16_t lead, char16_t trail) {
+        return ((((char32_t) lead - 0xd800U) << 10) + ((char32_t) trail - 0xdc00U) + 0x10000U);
+}
+
+size_t utf8_n_codepoints(const char *str);
+size_t utf8_console_width(const char *str);
diff --git a/src/basic/util.c b/src/basic/util.c
new file mode 100644
index 0000000..e577c93
--- /dev/null
+++ b/src/basic/util.c
@@ -0,0 +1,637 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <alloca.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <sys/statfs.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "btrfs-util.h"
+#include "build.h"
+#include "cgroup-util.h"
+#include "def.h"
+#include "device-nodes.h"
+#include "dirent-util.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "hashmap.h"
+#include "hostname-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "procfs-util.h"
+#include "set.h"
+#include "signal-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "umask-util.h"
+#include "user-util.h"
+#include "util.h"
+#include "virt.h"
+
+int saved_argc = 0;
+char **saved_argv = NULL;
+static int saved_in_initrd = -1;
+
+size_t page_size(void) {
+        static thread_local size_t pgsz = 0;
+        long r;
+
+        if (_likely_(pgsz > 0))
+                return pgsz;
+
+        r = sysconf(_SC_PAGESIZE);
+        assert(r > 0);
+
+        pgsz = (size_t) r;
+        return pgsz;
+}
+
+bool plymouth_running(void) {
+        return access("/run/plymouth/pid", F_OK) >= 0;
+}
+
+bool display_is_local(const char *display) {
+        assert(display);
+
+        return
+                display[0] == ':' &&
+                display[1] >= '0' &&
+                display[1] <= '9';
+}
+
+bool kexec_loaded(void) {
+       _cleanup_free_ char *s = NULL;
+
+       if (read_one_line_file("/sys/kernel/kexec_loaded", &s) < 0)
+               return false;
+
+       return s[0] == '1';
+}
+
+int prot_from_flags(int flags) {
+
+        switch (flags & O_ACCMODE) {
+
+        case O_RDONLY:
+                return PROT_READ;
+
+        case O_WRONLY:
+                return PROT_WRITE;
+
+        case O_RDWR:
+                return PROT_READ|PROT_WRITE;
+
+        default:
+                return -EINVAL;
+        }
+}
+
+bool in_initrd(void) {
+        struct statfs s;
+        int r;
+
+        if (saved_in_initrd >= 0)
+                return saved_in_initrd;
+
+        /* We make two checks here:
+         *
+         * 1. the flag file /etc/initrd-release must exist
+         * 2. the root file system must be a memory file system
+         *
+         * The second check is extra paranoia, since misdetecting an
+         * initrd can have bad consequences due the initrd
+         * emptying when transititioning to the main systemd.
+         */
+
+        r = getenv_bool_secure("SYSTEMD_IN_INITRD");
+        if (r < 0 && r != -ENXIO)
+                log_debug_errno(r, "Failed to parse $SYSTEMD_IN_INITRD, ignoring: %m");
+
+        if (r >= 0)
+                saved_in_initrd = r > 0;
+        else
+                saved_in_initrd = access("/etc/initrd-release", F_OK) >= 0 &&
+                                  statfs("/", &s) >= 0 &&
+                                  is_temporary_fs(&s);
+
+        return saved_in_initrd;
+}
+
+void in_initrd_force(bool value) {
+        saved_in_initrd = value;
+}
+
+/* hey glibc, APIs with callbacks without a user pointer are so useless */
+void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
+                 __compar_d_fn_t compar, void *arg) {
+        size_t l, u, idx;
+        const void *p;
+        int comparison;
+
+        assert(!size_multiply_overflow(nmemb, size));
+
+        l = 0;
+        u = nmemb;
+        while (l < u) {
+                idx = (l + u) / 2;
+                p = (const uint8_t*) base + idx * size;
+                comparison = compar(key, p, arg);
+                if (comparison < 0)
+                        u = idx;
+                else if (comparison > 0)
+                        l = idx + 1;
+                else
+                        return (void *)p;
+        }
+        return NULL;
+}
+
+bool memeqzero(const void *data, size_t length) {
+        /* Does the buffer consist entirely of NULs?
+         * Copied from https://github.com/systemd/casync/, copied in turn from
+         * https://github.com/rustyrussell/ccan/blob/master/ccan/mem/mem.c#L92,
+         * which is licensed CC-0.
+         */
+
+        const uint8_t *p = data;
+        size_t i;
+
+        /* Check first 16 bytes manually */
+        for (i = 0; i < 16; i++, length--) {
+                if (length == 0)
+                        return true;
+                if (p[i])
+                        return false;
+        }
+
+        /* Now we know first 16 bytes are NUL, memcmp with self.  */
+        return memcmp(data, p + i, length) == 0;
+}
+
+int on_ac_power(void) {
+        bool found_offline = false, found_online = false;
+        _cleanup_closedir_ DIR *d = NULL;
+        struct dirent *de;
+
+        d = opendir("/sys/class/power_supply");
+        if (!d)
+                return errno == ENOENT ? true : -errno;
+
+        FOREACH_DIRENT(de, d, return -errno) {
+                _cleanup_close_ int fd = -1, device = -1;
+                char contents[6];
+                ssize_t n;
+
+                device = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY|O_CLOEXEC|O_NOCTTY);
+                if (device < 0) {
+                        if (IN_SET(errno, ENOENT, ENOTDIR))
+                                continue;
+
+                        return -errno;
+                }
+
+                fd = openat(device, "type", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+                if (fd < 0) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        return -errno;
+                }
+
+                n = read(fd, contents, sizeof(contents));
+                if (n < 0)
+                        return -errno;
+
+                if (n != 6 || memcmp(contents, "Mains\n", 6))
+                        continue;
+
+                safe_close(fd);
+                fd = openat(device, "online", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+                if (fd < 0) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        return -errno;
+                }
+
+                n = read(fd, contents, sizeof(contents));
+                if (n < 0)
+                        return -errno;
+
+                if (n != 2 || contents[1] != '\n')
+                        return -EIO;
+
+                if (contents[0] == '1') {
+                        found_online = true;
+                        break;
+                } else if (contents[0] == '0')
+                        found_offline = true;
+                else
+                        return -EIO;
+        }
+
+        return found_online || !found_offline;
+}
+
+int container_get_leader(const char *machine, pid_t *pid) {
+        _cleanup_free_ char *s = NULL, *class = NULL;
+        const char *p;
+        pid_t leader;
+        int r;
+
+        assert(machine);
+        assert(pid);
+
+        if (streq(machine, ".host")) {
+                *pid = 1;
+                return 0;
+        }
+
+        if (!machine_name_is_valid(machine))
+                return -EINVAL;
+
+        p = strjoina("/run/systemd/machines/", machine);
+        r = parse_env_file(NULL, p,
+                           "LEADER", &s,
+                           "CLASS", &class);
+        if (r == -ENOENT)
+                return -EHOSTDOWN;
+        if (r < 0)
+                return r;
+        if (!s)
+                return -EIO;
+
+        if (!streq_ptr(class, "container"))
+                return -EIO;
+
+        r = parse_pid(s, &leader);
+        if (r < 0)
+                return r;
+        if (leader <= 1)
+                return -EIO;
+
+        *pid = leader;
+        return 0;
+}
+
+int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd) {
+        _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, netnsfd = -1, usernsfd = -1;
+        int rfd = -1;
+
+        assert(pid >= 0);
+
+        if (mntns_fd) {
+                const char *mntns;
+
+                mntns = procfs_file_alloca(pid, "ns/mnt");
+                mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+                if (mntnsfd < 0)
+                        return -errno;
+        }
+
+        if (pidns_fd) {
+                const char *pidns;
+
+                pidns = procfs_file_alloca(pid, "ns/pid");
+                pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+                if (pidnsfd < 0)
+                        return -errno;
+        }
+
+        if (netns_fd) {
+                const char *netns;
+
+                netns = procfs_file_alloca(pid, "ns/net");
+                netnsfd = open(netns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+                if (netnsfd < 0)
+                        return -errno;
+        }
+
+        if (userns_fd) {
+                const char *userns;
+
+                userns = procfs_file_alloca(pid, "ns/user");
+                usernsfd = open(userns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+                if (usernsfd < 0 && errno != ENOENT)
+                        return -errno;
+        }
+
+        if (root_fd) {
+                const char *root;
+
+                root = procfs_file_alloca(pid, "root");
+                rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+                if (rfd < 0)
+                        return -errno;
+        }
+
+        if (pidns_fd)
+                *pidns_fd = pidnsfd;
+
+        if (mntns_fd)
+                *mntns_fd = mntnsfd;
+
+        if (netns_fd)
+                *netns_fd = netnsfd;
+
+        if (userns_fd)
+                *userns_fd = usernsfd;
+
+        if (root_fd)
+                *root_fd = rfd;
+
+        pidnsfd = mntnsfd = netnsfd = usernsfd = -1;
+
+        return 0;
+}
+
+int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd) {
+        if (userns_fd >= 0) {
+                /* Can't setns to your own userns, since then you could
+                 * escalate from non-root to root in your own namespace, so
+                 * check if namespaces equal before attempting to enter. */
+                _cleanup_free_ char *userns_fd_path = NULL;
+                int r;
+                if (asprintf(&userns_fd_path, "/proc/self/fd/%d", userns_fd) < 0)
+                        return -ENOMEM;
+
+                r = files_same(userns_fd_path, "/proc/self/ns/user", 0);
+                if (r < 0)
+                        return r;
+                if (r)
+                        userns_fd = -1;
+        }
+
+        if (pidns_fd >= 0)
+                if (setns(pidns_fd, CLONE_NEWPID) < 0)
+                        return -errno;
+
+        if (mntns_fd >= 0)
+                if (setns(mntns_fd, CLONE_NEWNS) < 0)
+                        return -errno;
+
+        if (netns_fd >= 0)
+                if (setns(netns_fd, CLONE_NEWNET) < 0)
+                        return -errno;
+
+        if (userns_fd >= 0)
+                if (setns(userns_fd, CLONE_NEWUSER) < 0)
+                        return -errno;
+
+        if (root_fd >= 0) {
+                if (fchdir(root_fd) < 0)
+                        return -errno;
+
+                if (chroot(".") < 0)
+                        return -errno;
+        }
+
+        return reset_uid_gid();
+}
+
+uint64_t physical_memory(void) {
+        _cleanup_free_ char *root = NULL, *value = NULL;
+        uint64_t mem, lim;
+        size_t ps;
+        long sc;
+        int r;
+
+        /* We return this as uint64_t in case we are running as 32bit process on a 64bit kernel with huge amounts of
+         * memory.
+         *
+         * In order to support containers nicely that have a configured memory limit we'll take the minimum of the
+         * physically reported amount of memory and the limit configured for the root cgroup, if there is any. */
+
+        sc = sysconf(_SC_PHYS_PAGES);
+        assert(sc > 0);
+
+        ps = page_size();
+        mem = (uint64_t) sc * (uint64_t) ps;
+
+        r = cg_get_root_path(&root);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to determine root cgroup, ignoring cgroup memory limit: %m");
+                return mem;
+        }
+
+        r = cg_all_unified();
+        if (r < 0) {
+                log_debug_errno(r, "Failed to determine root unified mode, ignoring cgroup memory limit: %m");
+                return mem;
+        }
+        if (r > 0) {
+                r = cg_get_attribute("memory", root, "memory.max", &value);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to read memory.max cgroup attribute, ignoring cgroup memory limit: %m");
+                        return mem;
+                }
+
+                if (streq(value, "max"))
+                        return mem;
+        } else {
+                r = cg_get_attribute("memory", root, "memory.limit_in_bytes", &value);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to read memory.limit_in_bytes cgroup attribute, ignoring cgroup memory limit: %m");
+                        return mem;
+                }
+        }
+
+        r = safe_atou64(value, &lim);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to parse cgroup memory limit '%s', ignoring: %m", value);
+                return mem;
+        }
+        if (lim == UINT64_MAX)
+                return mem;
+
+        /* Make sure the limit is a multiple of our own page size */
+        lim /= ps;
+        lim *= ps;
+
+        return MIN(mem, lim);
+}
+
+uint64_t physical_memory_scale(uint64_t v, uint64_t max) {
+        uint64_t p, m, ps, r;
+
+        assert(max > 0);
+
+        /* Returns the physical memory size, multiplied by v divided by max. Returns UINT64_MAX on overflow. On success
+         * the result is a multiple of the page size (rounds down). */
+
+        ps = page_size();
+        assert(ps > 0);
+
+        p = physical_memory() / ps;
+        assert(p > 0);
+
+        m = p * v;
+        if (m / p != v)
+                return UINT64_MAX;
+
+        m /= max;
+
+        r = m * ps;
+        if (r / ps != m)
+                return UINT64_MAX;
+
+        return r;
+}
+
+uint64_t system_tasks_max(void) {
+
+        uint64_t a = TASKS_MAX, b = TASKS_MAX;
+        _cleanup_free_ char *root = NULL;
+        int r;
+
+        /* Determine the maximum number of tasks that may run on this system. We check three sources to determine this
+         * limit:
+         *
+         * a) the maximum tasks value the kernel allows on this architecture
+         * b) the cgroups pids_max attribute for the system
+         * c) the kernel's configured maximum PID value
+         *
+         * And then pick the smallest of the three */
+
+        r = procfs_tasks_get_limit(&a);
+        if (r < 0)
+                log_debug_errno(r, "Failed to read maximum number of tasks from /proc, ignoring: %m");
+
+        r = cg_get_root_path(&root);
+        if (r < 0)
+                log_debug_errno(r, "Failed to determine cgroup root path, ignoring: %m");
+        else {
+                _cleanup_free_ char *value = NULL;
+
+                r = cg_get_attribute("pids", root, "pids.max", &value);
+                if (r < 0)
+                        log_debug_errno(r, "Failed to read pids.max attribute of cgroup root, ignoring: %m");
+                else if (!streq(value, "max")) {
+                        r = safe_atou64(value, &b);
+                        if (r < 0)
+                                log_debug_errno(r, "Failed to parse pids.max attribute of cgroup root, ignoring: %m");
+                }
+        }
+
+        return MIN3(TASKS_MAX,
+                    a <= 0 ? TASKS_MAX : a,
+                    b <= 0 ? TASKS_MAX : b);
+}
+
+uint64_t system_tasks_max_scale(uint64_t v, uint64_t max) {
+        uint64_t t, m;
+
+        assert(max > 0);
+
+        /* Multiply the system's task value by the fraction v/max. Hence, if max==100 this calculates percentages
+         * relative to the system's maximum number of tasks. Returns UINT64_MAX on overflow. */
+
+        t = system_tasks_max();
+        assert(t > 0);
+
+        m = t * v;
+        if (m / t != v) /* overflow? */
+                return UINT64_MAX;
+
+        return m / max;
+}
+
+int version(void) {
+        puts("systemd " STRINGIFY(PROJECT_VERSION) " (" GIT_VERSION ")\n"
+             SYSTEMD_FEATURES);
+        return 0;
+}
+
+/* This is a direct translation of str_verscmp from boot.c */
+static bool is_digit(int c) {
+        return c >= '0' && c <= '9';
+}
+
+static int c_order(int c) {
+        if (c == 0 || is_digit(c))
+                return 0;
+
+        if ((c >= 'a') && (c <= 'z'))
+                return c;
+
+        return c + 0x10000;
+}
+
+int str_verscmp(const char *s1, const char *s2) {
+        const char *os1, *os2;
+
+        assert(s1);
+        assert(s2);
+
+        os1 = s1;
+        os2 = s2;
+
+        while (*s1 || *s2) {
+                int first;
+
+                while ((*s1 && !is_digit(*s1)) || (*s2 && !is_digit(*s2))) {
+                        int order;
+
+                        order = c_order(*s1) - c_order(*s2);
+                        if (order != 0)
+                                return order;
+                        s1++;
+                        s2++;
+                }
+
+                while (*s1 == '0')
+                        s1++;
+                while (*s2 == '0')
+                        s2++;
+
+                first = 0;
+                while (is_digit(*s1) && is_digit(*s2)) {
+                        if (first == 0)
+                                first = *s1 - *s2;
+                        s1++;
+                        s2++;
+                }
+
+                if (is_digit(*s1))
+                        return 1;
+                if (is_digit(*s2))
+                        return -1;
+
+                if (first != 0)
+                        return first;
+        }
+
+        return strcmp(os1, os2);
+}
+
+/* Turn off core dumps but only if we're running outside of a container. */
+void disable_coredumps(void) {
+        int r;
+
+        if (detect_container() > 0)
+                return;
+
+        r = write_string_file("/proc/sys/kernel/core_pattern", "|/bin/false", WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0)
+                log_debug_errno(r, "Failed to turn off coredumps, ignoring: %m");
+}
diff --git a/src/basic/util.h b/src/basic/util.h
new file mode 100644
index 0000000..dc33d66
--- /dev/null
+++ b/src/basic/util.h
@@ -0,0 +1,253 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <alloca.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <locale.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/inotify.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "format-util.h"
+#include "macro.h"
+#include "time-util.h"
+
+size_t page_size(void) _pure_;
+#define PAGE_ALIGN(l) ALIGN_TO((l), page_size())
+
+static inline const char* yes_no(bool b) {
+        return b ? "yes" : "no";
+}
+
+static inline const char* true_false(bool b) {
+        return b ? "true" : "false";
+}
+
+static inline const char* one_zero(bool b) {
+        return b ? "1" : "0";
+}
+
+static inline const char* enable_disable(bool b) {
+        return b ? "enable" : "disable";
+}
+
+bool plymouth_running(void);
+
+bool display_is_local(const char *display) _pure_;
+
+#define NULSTR_FOREACH(i, l)                                    \
+        for ((i) = (l); (i) && *(i); (i) = strchr((i), 0)+1)
+
+#define NULSTR_FOREACH_PAIR(i, j, l)                             \
+        for ((i) = (l), (j) = strchr((i), 0)+1; (i) && *(i); (i) = strchr((j), 0)+1, (j) = *(i) ? strchr((i), 0)+1 : (i))
+
+extern int saved_argc;
+extern char **saved_argv;
+
+bool kexec_loaded(void);
+
+int prot_from_flags(int flags) _const_;
+
+bool in_initrd(void);
+void in_initrd_force(bool value);
+
+void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
+                 __compar_d_fn_t compar, void *arg);
+
+#define typesafe_bsearch_r(k, b, n, func, userdata)                     \
+        ({                                                              \
+                const typeof(b[0]) *_k = k;                             \
+                int (*_func_)(const typeof(b[0])*, const typeof(b[0])*, typeof(userdata)) = func; \
+                xbsearch_r((const void*) _k, (b), (n), sizeof((b)[0]), (__compar_d_fn_t) _func_, userdata); \
+        })
+
+/**
+ * Normal bsearch requires base to be nonnull. Here were require
+ * that only if nmemb > 0.
+ */
+static inline void* bsearch_safe(const void *key, const void *base,
+                                 size_t nmemb, size_t size, __compar_fn_t compar) {
+        if (nmemb <= 0)
+                return NULL;
+
+        assert(base);
+        return bsearch(key, base, nmemb, size, compar);
+}
+
+#define typesafe_bsearch(k, b, n, func)                                 \
+        ({                                                              \
+                const typeof(b[0]) *_k = k;                             \
+                int (*_func_)(const typeof(b[0])*, const typeof(b[0])*) = func; \
+                bsearch_safe((const void*) _k, (b), (n), sizeof((b)[0]), (__compar_fn_t) _func_); \
+        })
+
+/**
+ * Normal qsort requires base to be nonnull. Here were require
+ * that only if nmemb > 0.
+ */
+static inline void qsort_safe(void *base, size_t nmemb, size_t size, __compar_fn_t compar) {
+        if (nmemb <= 1)
+                return;
+
+        assert(base);
+        qsort(base, nmemb, size, compar);
+}
+
+/* A wrapper around the above, but that adds typesafety: the element size is automatically derived from the type and so
+ * is the prototype for the comparison function */
+#define typesafe_qsort(p, n, func)                                      \
+        ({                                                              \
+                int (*_func_)(const typeof(p[0])*, const typeof(p[0])*) = func; \
+                qsort_safe((p), (n), sizeof((p)[0]), (__compar_fn_t) _func_); \
+        })
+
+static inline void qsort_r_safe(void *base, size_t nmemb, size_t size, __compar_d_fn_t compar, void *userdata) {
+        if (nmemb <= 1)
+                return;
+
+        assert(base);
+        qsort_r(base, nmemb, size, compar, userdata);
+}
+
+#define typesafe_qsort_r(p, n, func, userdata)                          \
+        ({                                                              \
+                int (*_func_)(const typeof(p[0])*, const typeof(p[0])*, typeof(userdata)) = func; \
+                qsort_r_safe((p), (n), sizeof((p)[0]), (__compar_d_fn_t) _func_, userdata); \
+        })
+
+/* Normal memcpy requires src to be nonnull. We do nothing if n is 0. */
+static inline void memcpy_safe(void *dst, const void *src, size_t n) {
+        if (n == 0)
+                return;
+        assert(src);
+        memcpy(dst, src, n);
+}
+
+/* Normal memcmp requires s1 and s2 to be nonnull. We do nothing if n is 0. */
+static inline int memcmp_safe(const void *s1, const void *s2, size_t n) {
+        if (n == 0)
+                return 0;
+        assert(s1);
+        assert(s2);
+        return memcmp(s1, s2, n);
+}
+
+/* Compare s1 (length n1) with s2 (length n2) in lexicographic order. */
+static inline int memcmp_nn(const void *s1, size_t n1, const void *s2, size_t n2) {
+        return memcmp_safe(s1, s2, MIN(n1, n2))
+            ?: CMP(n1, n2);
+}
+
+int on_ac_power(void);
+
+#define memzero(x,l)                                            \
+        ({                                                      \
+                size_t _l_ = (l);                               \
+                void *_x_ = (x);                                \
+                _l_ == 0 ? _x_ : memset(_x_, 0, _l_);           \
+        })
+
+#define zero(x) (memzero(&(x), sizeof(x)))
+
+bool memeqzero(const void *data, size_t length);
+
+#define eqzero(x) memeqzero(x, sizeof(x))
+
+static inline void *mempset(void *s, int c, size_t n) {
+        memset(s, c, n);
+        return (uint8_t*)s + n;
+}
+
+static inline void _reset_errno_(int *saved_errno) {
+        if (*saved_errno < 0) /* Invalidated by UNPROTECT_ERRNO? */
+                return;
+
+        errno = *saved_errno;
+}
+
+#define PROTECT_ERRNO                                                   \
+        _cleanup_(_reset_errno_) _unused_ int _saved_errno_ = errno
+
+#define UNPROTECT_ERRNO                         \
+        do {                                    \
+                errno = _saved_errno_;          \
+                _saved_errno_ = -1;             \
+        } while (false)
+
+static inline int negative_errno(void) {
+        /* This helper should be used to shut up gcc if you know 'errno' is
+         * negative. Instead of "return -errno;", use "return negative_errno();"
+         * It will suppress bogus gcc warnings in case it assumes 'errno' might
+         * be 0 and thus the caller's error-handling might not be triggered. */
+        assert_return(errno > 0, -EINVAL);
+        return -errno;
+}
+
+static inline unsigned u64log2(uint64_t n) {
+#if __SIZEOF_LONG_LONG__ == 8
+        return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
+#else
+#error "Wut?"
+#endif
+}
+
+static inline unsigned u32ctz(uint32_t n) {
+#if __SIZEOF_INT__ == 4
+        return n != 0 ? __builtin_ctz(n) : 32;
+#else
+#error "Wut?"
+#endif
+}
+
+static inline unsigned log2i(int x) {
+        assert(x > 0);
+
+        return __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1;
+}
+
+static inline unsigned log2u(unsigned x) {
+        assert(x > 0);
+
+        return sizeof(unsigned) * 8 - __builtin_clz(x) - 1;
+}
+
+static inline unsigned log2u_round_up(unsigned x) {
+        assert(x > 0);
+
+        if (x == 1)
+                return 0;
+
+        return log2u(x - 1) + 1;
+}
+
+int container_get_leader(const char *machine, pid_t *pid);
+
+int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd);
+int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd);
+
+uint64_t physical_memory(void);
+uint64_t physical_memory_scale(uint64_t v, uint64_t max);
+
+uint64_t system_tasks_max(void);
+uint64_t system_tasks_max_scale(uint64_t v, uint64_t max);
+
+int version(void);
+
+int str_verscmp(const char *s1, const char *s2);
+
+void disable_coredumps(void);
diff --git a/src/basic/virt.c b/src/basic/virt.c
new file mode 100644
index 0000000..f63f15f
--- /dev/null
+++ b/src/basic/virt.c
@@ -0,0 +1,642 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#if defined(__i386__) || defined(__x86_64__)
+#include <cpuid.h>
+#endif
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "dirent-util.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "macro.h"
+#include "process-util.h"
+#include "stat-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "virt.h"
+
+static int detect_vm_cpuid(void) {
+
+        /* CPUID is an x86 specific interface. */
+#if defined(__i386__) || defined(__x86_64__)
+
+        static const struct {
+                const char *cpuid;
+                int id;
+        } cpuid_vendor_table[] = {
+                { "XenVMMXenVMM", VIRTUALIZATION_XEN       },
+                { "KVMKVMKVM",    VIRTUALIZATION_KVM       },
+                { "TCGTCGTCGTCG", VIRTUALIZATION_QEMU      },
+                /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
+                { "VMwareVMware", VIRTUALIZATION_VMWARE    },
+                /* https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs */
+                { "Microsoft Hv", VIRTUALIZATION_MICROSOFT },
+                /* https://wiki.freebsd.org/bhyve */
+                { "bhyve bhyve ", VIRTUALIZATION_BHYVE     },
+                { "QNXQVMBSQG",   VIRTUALIZATION_QNX       },
+        };
+
+        uint32_t eax, ebx, ecx, edx;
+        bool hypervisor;
+
+        /* http://lwn.net/Articles/301888/ */
+
+        /* First detect whether there is a hypervisor */
+        if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) == 0)
+                return VIRTUALIZATION_NONE;
+
+        hypervisor = ecx & 0x80000000U;
+
+        if (hypervisor) {
+                union {
+                        uint32_t sig32[3];
+                        char text[13];
+                } sig = {};
+                unsigned j;
+
+                /* There is a hypervisor, see what it is */
+                __cpuid(0x40000000U, eax, ebx, ecx, edx);
+
+                sig.sig32[0] = ebx;
+                sig.sig32[1] = ecx;
+                sig.sig32[2] = edx;
+
+                log_debug("Virtualization found, CPUID=%s", sig.text);
+
+                for (j = 0; j < ELEMENTSOF(cpuid_vendor_table); j ++)
+                        if (streq(sig.text, cpuid_vendor_table[j].cpuid))
+                                return cpuid_vendor_table[j].id;
+
+                return VIRTUALIZATION_VM_OTHER;
+        }
+#endif
+        log_debug("No virtualization found in CPUID");
+
+        return VIRTUALIZATION_NONE;
+}
+
+static int detect_vm_device_tree(void) {
+#if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
+        _cleanup_free_ char *hvtype = NULL;
+        int r;
+
+        r = read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype);
+        if (r == -ENOENT) {
+                _cleanup_closedir_ DIR *dir = NULL;
+                struct dirent *dent;
+
+                dir = opendir("/proc/device-tree");
+                if (!dir) {
+                        if (errno == ENOENT) {
+                                log_debug_errno(errno, "/proc/device-tree: %m");
+                                return VIRTUALIZATION_NONE;
+                        }
+                        return -errno;
+                }
+
+                FOREACH_DIRENT(dent, dir, return -errno)
+                        if (strstr(dent->d_name, "fw-cfg")) {
+                                log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent->d_name);
+                                return VIRTUALIZATION_QEMU;
+                        }
+
+                log_debug("No virtualization found in /proc/device-tree/*");
+                return VIRTUALIZATION_NONE;
+        } else if (r < 0)
+                return r;
+
+        log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype);
+        if (streq(hvtype, "linux,kvm"))
+                return VIRTUALIZATION_KVM;
+        else if (strstr(hvtype, "xen"))
+                return VIRTUALIZATION_XEN;
+        else
+                return VIRTUALIZATION_VM_OTHER;
+#else
+        log_debug("This platform does not support /proc/device-tree");
+        return VIRTUALIZATION_NONE;
+#endif
+}
+
+static int detect_vm_dmi(void) {
+#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
+
+        static const char *const dmi_vendors[] = {
+                "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
+                "/sys/class/dmi/id/sys_vendor",
+                "/sys/class/dmi/id/board_vendor",
+                "/sys/class/dmi/id/bios_vendor"
+        };
+
+        static const struct {
+                const char *vendor;
+                int id;
+        } dmi_vendor_table[] = {
+                { "KVM",           VIRTUALIZATION_KVM       },
+                { "QEMU",          VIRTUALIZATION_QEMU      },
+                /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
+                { "VMware",        VIRTUALIZATION_VMWARE    },
+                { "VMW",           VIRTUALIZATION_VMWARE    },
+                { "innotek GmbH",  VIRTUALIZATION_ORACLE    },
+                { "Xen",           VIRTUALIZATION_XEN       },
+                { "Bochs",         VIRTUALIZATION_BOCHS     },
+                { "Parallels",     VIRTUALIZATION_PARALLELS },
+                /* https://wiki.freebsd.org/bhyve */
+                { "BHYVE",         VIRTUALIZATION_BHYVE     },
+        };
+        unsigned i;
+        int r;
+
+        for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
+                _cleanup_free_ char *s = NULL;
+                unsigned j;
+
+                r = read_one_line_file(dmi_vendors[i], &s);
+                if (r < 0) {
+                        if (r == -ENOENT)
+                                continue;
+
+                        return r;
+                }
+
+                for (j = 0; j < ELEMENTSOF(dmi_vendor_table); j++)
+                        if (startswith(s, dmi_vendor_table[j].vendor)) {
+                                log_debug("Virtualization %s found in DMI (%s)", s, dmi_vendors[i]);
+                                return dmi_vendor_table[j].id;
+                        }
+        }
+#endif
+
+        log_debug("No virtualization found in DMI");
+
+        return VIRTUALIZATION_NONE;
+}
+
+static int detect_vm_xen(void) {
+
+        /* Check for Dom0 will be executed later in detect_vm_xen_dom0
+           The presence of /proc/xen indicates some form of a Xen domain */
+        if (access("/proc/xen", F_OK) < 0) {
+                log_debug("Virtualization XEN not found, /proc/xen does not exist");
+                return VIRTUALIZATION_NONE;
+        }
+
+        log_debug("Virtualization XEN found (/proc/xen exists)");
+        return VIRTUALIZATION_XEN;
+}
+
+#define XENFEAT_dom0 11 /* xen/include/public/features.h */
+#define PATH_FEATURES "/sys/hypervisor/properties/features"
+/* Returns -errno, or 0 for domU, or 1 for dom0 */
+static int detect_vm_xen_dom0(void) {
+        _cleanup_free_ char *domcap = NULL;
+        char *cap, *i;
+        int r;
+
+        r = read_one_line_file(PATH_FEATURES, &domcap);
+        if (r < 0 && r != -ENOENT)
+                return r;
+        if (r == 0) {
+                unsigned long features;
+
+                /* Here, we need to use sscanf() instead of safe_atoul()
+                 * as the string lacks the leading "0x". */
+                r = sscanf(domcap, "%lx", &features);
+                if (r == 1) {
+                        r = !!(features & (1U << XENFEAT_dom0));
+                        log_debug("Virtualization XEN, found %s with value %08lx, "
+                                  "XENFEAT_dom0 (indicating the 'hardware domain') is%s set.",
+                                  PATH_FEATURES, features, r ? "" : " not");
+                        return r;
+                }
+                log_debug("Virtualization XEN, found %s, unhandled content '%s'",
+                          PATH_FEATURES, domcap);
+        }
+
+        r = read_one_line_file("/proc/xen/capabilities", &domcap);
+        if (r == -ENOENT) {
+                log_debug("Virtualization XEN because /proc/xen/capabilities does not exist");
+                return 0;
+        }
+        if (r < 0)
+                return r;
+
+        i = domcap;
+        while ((cap = strsep(&i, ",")))
+                if (streq(cap, "control_d"))
+                        break;
+        if (!cap) {
+                log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
+                return 0;
+        }
+
+        log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
+        return 1;
+}
+
+static int detect_vm_hypervisor(void) {
+        _cleanup_free_ char *hvtype = NULL;
+        int r;
+
+        r = read_one_line_file("/sys/hypervisor/type", &hvtype);
+        if (r == -ENOENT)
+                return VIRTUALIZATION_NONE;
+        if (r < 0)
+                return r;
+
+        log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype);
+
+        if (streq(hvtype, "xen"))
+                return VIRTUALIZATION_XEN;
+        else
+                return VIRTUALIZATION_VM_OTHER;
+}
+
+static int detect_vm_uml(void) {
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        /* Detect User-Mode Linux by reading /proc/cpuinfo */
+        f = fopen("/proc/cpuinfo", "re");
+        if (!f) {
+                if (errno == ENOENT) {
+                        log_debug("/proc/cpuinfo not found, assuming no UML virtualization.");
+                        return VIRTUALIZATION_NONE;
+                }
+                return -errno;
+        }
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                const char *t;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        break;
+
+                t = startswith(line, "vendor_id\t: ");
+                if (t) {
+                        if (startswith(t, "User Mode Linux")) {
+                                log_debug("UML virtualization found in /proc/cpuinfo");
+                                return VIRTUALIZATION_UML;
+                        }
+
+                        break;
+                }
+        }
+
+        log_debug("UML virtualization not found in /proc/cpuinfo.");
+        return VIRTUALIZATION_NONE;
+}
+
+static int detect_vm_zvm(void) {
+
+#if defined(__s390__)
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        r = get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE, &t);
+        if (r == -ENOENT)
+                return VIRTUALIZATION_NONE;
+        if (r < 0)
+                return r;
+
+        log_debug("Virtualization %s found in /proc/sysinfo", t);
+        if (streq(t, "z/VM"))
+                return VIRTUALIZATION_ZVM;
+        else
+                return VIRTUALIZATION_KVM;
+#else
+        log_debug("This platform does not support /proc/sysinfo");
+        return VIRTUALIZATION_NONE;
+#endif
+}
+
+/* Returns a short identifier for the various VM implementations */
+int detect_vm(void) {
+        static thread_local int cached_found = _VIRTUALIZATION_INVALID;
+        bool other = false;
+        int r, dmi;
+
+        if (cached_found >= 0)
+                return cached_found;
+
+        /* We have to use the correct order here:
+         *
+         * → First, try to detect Oracle Virtualbox, even if it uses KVM, as well as Xen even if it cloaks as Microsoft
+         *   Hyper-V.
+         *
+         * → Second, try to detect from CPUID, this will report KVM for whatever software is used even if info in DMI is
+         *   overwritten.
+         *
+         * → Third, try to detect from DMI. */
+
+        dmi = detect_vm_dmi();
+        if (IN_SET(dmi, VIRTUALIZATION_ORACLE, VIRTUALIZATION_XEN)) {
+                r = dmi;
+                goto finish;
+        }
+
+        r = detect_vm_cpuid();
+        if (r < 0)
+                return r;
+        if (r == VIRTUALIZATION_VM_OTHER)
+                other = true;
+        else if (r != VIRTUALIZATION_NONE)
+                goto finish;
+
+        /* Now, let's get back to DMI */
+        if (dmi < 0)
+                return dmi;
+        if (dmi == VIRTUALIZATION_VM_OTHER)
+                other = true;
+        else if (dmi != VIRTUALIZATION_NONE) {
+                r = dmi;
+                goto finish;
+        }
+
+        /* x86 xen will most likely be detected by cpuid. If not (most likely
+         * because we're not an x86 guest), then we should try the /proc/xen
+         * directory next. If that's not found, then we check for the high-level
+         * hypervisor sysfs file.
+         */
+
+        r = detect_vm_xen();
+        if (r < 0)
+                return r;
+        if (r == VIRTUALIZATION_VM_OTHER)
+                other = true;
+        else if (r != VIRTUALIZATION_NONE)
+                goto finish;
+
+        r = detect_vm_hypervisor();
+        if (r < 0)
+                return r;
+        if (r == VIRTUALIZATION_VM_OTHER)
+                other = true;
+        else if (r != VIRTUALIZATION_NONE)
+                goto finish;
+
+        r = detect_vm_device_tree();
+        if (r < 0)
+                return r;
+        if (r == VIRTUALIZATION_VM_OTHER)
+                other = true;
+        else if (r != VIRTUALIZATION_NONE)
+                goto finish;
+
+        r = detect_vm_uml();
+        if (r < 0)
+                return r;
+        if (r == VIRTUALIZATION_VM_OTHER)
+                other = true;
+        else if (r != VIRTUALIZATION_NONE)
+                goto finish;
+
+        r = detect_vm_zvm();
+        if (r < 0)
+                return r;
+
+finish:
+        /* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
+         * In order to detect the Dom0 as not virtualization we need to
+         * double-check it */
+        if (r == VIRTUALIZATION_XEN) {
+                int dom0;
+
+                dom0 = detect_vm_xen_dom0();
+                if (dom0 < 0)
+                        return dom0;
+                if (dom0 > 0)
+                        r = VIRTUALIZATION_NONE;
+        } else if (r == VIRTUALIZATION_NONE && other)
+                r = VIRTUALIZATION_VM_OTHER;
+
+        cached_found = r;
+        log_debug("Found VM virtualization %s", virtualization_to_string(r));
+        return r;
+}
+
+int detect_container(void) {
+
+        static const struct {
+                const char *value;
+                int id;
+        } value_table[] = {
+                { "lxc",            VIRTUALIZATION_LXC            },
+                { "lxc-libvirt",    VIRTUALIZATION_LXC_LIBVIRT    },
+                { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
+                { "docker",         VIRTUALIZATION_DOCKER         },
+                { "rkt",            VIRTUALIZATION_RKT            },
+        };
+
+        static thread_local int cached_found = _VIRTUALIZATION_INVALID;
+        _cleanup_free_ char *m = NULL;
+        const char *e = NULL;
+        unsigned j;
+        int r;
+
+        if (cached_found >= 0)
+                return cached_found;
+
+        /* /proc/vz exists in container and outside of the container, /proc/bc only outside of the container. */
+        if (access("/proc/vz", F_OK) >= 0 &&
+            access("/proc/bc", F_OK) < 0) {
+                r = VIRTUALIZATION_OPENVZ;
+                goto finish;
+        }
+
+        if (getpid_cached() == 1) {
+                /* If we are PID 1 we can just check our own environment variable, and that's authoritative. */
+
+                e = getenv("container");
+                if (isempty(e)) {
+                        r = VIRTUALIZATION_NONE;
+                        goto finish;
+                }
+
+                goto translate_name;
+        }
+
+        /* Otherwise, PID 1 might have dropped this information into a file in /run. This is better than accessing
+         * /proc/1/environ, since we don't need CAP_SYS_PTRACE for that. */
+        r = read_one_line_file("/run/systemd/container", &m);
+        if (r >= 0) {
+                e = m;
+                goto translate_name;
+        }
+        if (r != -ENOENT)
+                return log_debug_errno(r, "Failed to read /run/systemd/container: %m");
+
+        /* Fallback for cases where PID 1 was not systemd (for example, cases where init=/bin/sh is used. */
+        r = getenv_for_pid(1, "container", &m);
+        if (r > 0) {
+                e = m;
+                goto translate_name;
+        }
+        if (r < 0) /* This only works if we have CAP_SYS_PTRACE, hence let's better ignore failures here */
+                log_debug_errno(r, "Failed to read $container of PID 1, ignoring: %m");
+
+        /* Interestingly /proc/1/sched actually shows the host's PID for what we see as PID 1. Hence, if the PID shown
+         * there is not 1, we know we are in a PID namespace. and hence a container. */
+        r = read_one_line_file("/proc/1/sched", &m);
+        if (r >= 0) {
+                const char *t;
+
+                t = strrchr(m, '(');
+                if (!t)
+                        return -EIO;
+
+                if (!startswith(t, "(1,")) {
+                        r = VIRTUALIZATION_CONTAINER_OTHER;
+                        goto finish;
+                }
+        } else if (r != -ENOENT)
+                return r;
+
+        /* If that didn't work, give up, assume no container manager. */
+        r = VIRTUALIZATION_NONE;
+        goto finish;
+
+translate_name:
+        for (j = 0; j < ELEMENTSOF(value_table); j++)
+                if (streq(e, value_table[j].value)) {
+                        r = value_table[j].id;
+                        goto finish;
+                }
+
+        r = VIRTUALIZATION_CONTAINER_OTHER;
+
+finish:
+        log_debug("Found container virtualization %s.", virtualization_to_string(r));
+        cached_found = r;
+        return r;
+}
+
+int detect_virtualization(void) {
+        int r;
+
+        r = detect_container();
+        if (r == 0)
+                r = detect_vm();
+
+        return r;
+}
+
+static int userns_has_mapping(const char *name) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *buf = NULL;
+        size_t n_allocated = 0;
+        ssize_t n;
+        uint32_t a, b, c;
+        int r;
+
+        f = fopen(name, "re");
+        if (!f) {
+                log_debug_errno(errno, "Failed to open %s: %m", name);
+                return errno == ENOENT ? false : -errno;
+        }
+
+        n = getline(&buf, &n_allocated, f);
+        if (n < 0) {
+                if (feof(f)) {
+                        log_debug("%s is empty, we're in an uninitialized user namespace", name);
+                        return true;
+                }
+
+                return log_debug_errno(errno, "Failed to read %s: %m", name);
+        }
+
+        r = sscanf(buf, "%"PRIu32" %"PRIu32" %"PRIu32, &a, &b, &c);
+        if (r < 3)
+                return log_debug_errno(errno, "Failed to parse %s: %m", name);
+
+        if (a == 0 && b == 0 && c == UINT32_MAX) {
+                /* The kernel calls mappings_overlap() and does not allow overlaps */
+                log_debug("%s has a full 1:1 mapping", name);
+                return false;
+        }
+
+        /* Anything else implies that we are in a user namespace */
+        log_debug("Mapping found in %s, we're in a user namespace", name);
+        return true;
+}
+
+int running_in_userns(void) {
+        _cleanup_free_ char *line = NULL;
+        int r;
+
+        r = userns_has_mapping("/proc/self/uid_map");
+        if (r != 0)
+                return r;
+
+        r = userns_has_mapping("/proc/self/gid_map");
+        if (r != 0)
+                return r;
+
+        /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
+         * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
+         * also does not exist. We cannot distinguish those two cases, so assume that
+         * we're running on a stripped-down recent kernel, rather than on an old one,
+         * and if the file is not found, return false.
+         */
+        r = read_one_line_file("/proc/self/setgroups", &line);
+        if (r < 0) {
+                log_debug_errno(r, "/proc/self/setgroups: %m");
+                return r == -ENOENT ? false : r;
+        }
+
+        truncate_nl(line);
+        r = streq(line, "deny");
+        /* See user_namespaces(7) for a description of this "setgroups" contents. */
+        log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line, r ? "in" : "not in");
+        return r;
+}
+
+int running_in_chroot(void) {
+        int r;
+
+        if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
+                return 0;
+
+        r = files_same("/proc/1/root", "/", 0);
+        if (r < 0)
+                return r;
+
+        return r == 0;
+}
+
+static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
+        [VIRTUALIZATION_NONE] = "none",
+        [VIRTUALIZATION_KVM] = "kvm",
+        [VIRTUALIZATION_QEMU] = "qemu",
+        [VIRTUALIZATION_BOCHS] = "bochs",
+        [VIRTUALIZATION_XEN] = "xen",
+        [VIRTUALIZATION_UML] = "uml",
+        [VIRTUALIZATION_VMWARE] = "vmware",
+        [VIRTUALIZATION_ORACLE] = "oracle",
+        [VIRTUALIZATION_MICROSOFT] = "microsoft",
+        [VIRTUALIZATION_ZVM] = "zvm",
+        [VIRTUALIZATION_PARALLELS] = "parallels",
+        [VIRTUALIZATION_BHYVE] = "bhyve",
+        [VIRTUALIZATION_QNX] = "qnx",
+        [VIRTUALIZATION_VM_OTHER] = "vm-other",
+
+        [VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
+        [VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
+        [VIRTUALIZATION_LXC] = "lxc",
+        [VIRTUALIZATION_OPENVZ] = "openvz",
+        [VIRTUALIZATION_DOCKER] = "docker",
+        [VIRTUALIZATION_RKT] = "rkt",
+        [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(virtualization, int);
diff --git a/src/basic/virt.h b/src/basic/virt.h
new file mode 100644
index 0000000..c4cf4bf
--- /dev/null
+++ b/src/basic/virt.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "macro.h"
+
+enum {
+        VIRTUALIZATION_NONE = 0,
+
+        VIRTUALIZATION_VM_FIRST,
+        VIRTUALIZATION_KVM = VIRTUALIZATION_VM_FIRST,
+        VIRTUALIZATION_QEMU,
+        VIRTUALIZATION_BOCHS,
+        VIRTUALIZATION_XEN,
+        VIRTUALIZATION_UML,
+        VIRTUALIZATION_VMWARE,
+        VIRTUALIZATION_ORACLE,
+        VIRTUALIZATION_MICROSOFT,
+        VIRTUALIZATION_ZVM,
+        VIRTUALIZATION_PARALLELS,
+        VIRTUALIZATION_BHYVE,
+        VIRTUALIZATION_QNX,
+        VIRTUALIZATION_VM_OTHER,
+        VIRTUALIZATION_VM_LAST = VIRTUALIZATION_VM_OTHER,
+
+        VIRTUALIZATION_CONTAINER_FIRST,
+        VIRTUALIZATION_SYSTEMD_NSPAWN = VIRTUALIZATION_CONTAINER_FIRST,
+        VIRTUALIZATION_LXC_LIBVIRT,
+        VIRTUALIZATION_LXC,
+        VIRTUALIZATION_OPENVZ,
+        VIRTUALIZATION_DOCKER,
+        VIRTUALIZATION_RKT,
+        VIRTUALIZATION_CONTAINER_OTHER,
+        VIRTUALIZATION_CONTAINER_LAST = VIRTUALIZATION_CONTAINER_OTHER,
+
+        _VIRTUALIZATION_MAX,
+        _VIRTUALIZATION_INVALID = -1
+};
+
+static inline bool VIRTUALIZATION_IS_VM(int x) {
+        return x >= VIRTUALIZATION_VM_FIRST && x <= VIRTUALIZATION_VM_LAST;
+}
+
+static inline bool VIRTUALIZATION_IS_CONTAINER(int x) {
+        return x >= VIRTUALIZATION_CONTAINER_FIRST && x <= VIRTUALIZATION_CONTAINER_LAST;
+}
+
+int detect_vm(void);
+int detect_container(void);
+int detect_virtualization(void);
+
+int running_in_userns(void);
+int running_in_chroot(void);
+
+const char *virtualization_to_string(int v) _const_;
+int virtualization_from_string(const char *s) _pure_;
diff --git a/src/basic/xattr-util.c b/src/basic/xattr-util.c
new file mode 100644
index 0000000..0ee0979
--- /dev/null
+++ b/src/basic/xattr-util.c
@@ -0,0 +1,217 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/xattr.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "sparse-endian.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "time-util.h"
+#include "xattr-util.h"
+
+int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink) {
+        char *v;
+        size_t l;
+        ssize_t n;
+
+        assert(path);
+        assert(name);
+        assert(value);
+
+        for (l = 100; ; l = (size_t) n + 1) {
+                v = new0(char, l);
+                if (!v)
+                        return -ENOMEM;
+
+                if (allow_symlink)
+                        n = lgetxattr(path, name, v, l);
+                else
+                        n = getxattr(path, name, v, l);
+
+                if (n >= 0 && (size_t) n < l) {
+                        *value = v;
+                        return n;
+                }
+
+                free(v);
+
+                if (n < 0 && errno != ERANGE)
+                        return -errno;
+
+                if (allow_symlink)
+                        n = lgetxattr(path, name, NULL, 0);
+                else
+                        n = getxattr(path, name, NULL, 0);
+                if (n < 0)
+                        return -errno;
+        }
+}
+
+int fgetxattr_malloc(int fd, const char *name, char **value) {
+        char *v;
+        size_t l;
+        ssize_t n;
+
+        assert(fd >= 0);
+        assert(name);
+        assert(value);
+
+        for (l = 100; ; l = (size_t) n + 1) {
+                v = new0(char, l);
+                if (!v)
+                        return -ENOMEM;
+
+                n = fgetxattr(fd, name, v, l);
+
+                if (n >= 0 && (size_t) n < l) {
+                        *value = v;
+                        return n;
+                }
+
+                free(v);
+
+                if (n < 0 && errno != ERANGE)
+                        return -errno;
+
+                n = fgetxattr(fd, name, NULL, 0);
+                if (n < 0)
+                        return -errno;
+        }
+}
+
+int fgetxattrat_fake(
+                int dirfd,
+                const char *filename,
+                const char *attribute,
+                void *value, size_t size,
+                int flags,
+                size_t *ret_size) {
+
+        char fn[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
+        _cleanup_close_ int fd = -1;
+        ssize_t l;
+
+        /* The kernel doesn't have a fgetxattrat() command, hence let's emulate one */
+
+        if (flags & ~(AT_SYMLINK_NOFOLLOW|AT_EMPTY_PATH))
+                return -EINVAL;
+
+        if (isempty(filename)) {
+                if (!(flags & AT_EMPTY_PATH))
+                        return -EINVAL;
+
+                xsprintf(fn, "/proc/self/fd/%i", dirfd);
+        } else {
+                fd = openat(dirfd, filename, O_CLOEXEC|O_PATH|(flags & AT_SYMLINK_NOFOLLOW ? O_NOFOLLOW : 0));
+                if (fd < 0)
+                        return -errno;
+
+                xsprintf(fn, "/proc/self/fd/%i", fd);
+        }
+
+        l = getxattr(fn, attribute, value, size);
+        if (l < 0)
+                return -errno;
+
+        *ret_size = l;
+        return 0;
+}
+
+static int parse_crtime(le64_t le, usec_t *usec) {
+        uint64_t u;
+
+        assert(usec);
+
+        u = le64toh(le);
+        if (IN_SET(u, 0, (uint64_t) -1))
+                return -EIO;
+
+        *usec = (usec_t) u;
+        return 0;
+}
+
+int fd_getcrtime_at(int dirfd, const char *name, usec_t *ret, int flags) {
+        struct_statx sx;
+        usec_t a, b;
+        le64_t le;
+        size_t n;
+        int r;
+
+        assert(ret);
+
+        if (flags & ~(AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW))
+                return -EINVAL;
+
+        /* So here's the deal: the creation/birth time (crtime/btime) of a file is a relatively newly supported concept
+         * on Linux (or more strictly speaking: a concept that only recently got supported in the API, it was
+         * implemented on various file systems on the lower level since a while, but never was accessible). However, we
+         * needed a concept like that for vaccuuming algorithms and such, hence we emulated it via a user xattr for a
+         * long time. Starting with Linux 4.11 there's statx() which exposes the timestamp to userspace for the first
+         * time, where it is available. Thius function will read it, but it tries to keep some compatibility with older
+         * systems: we try to read both the crtime/btime and the xattr, and then use whatever is older. After all the
+         * concept is useful for determining how "old" a file really is, and hence using the older of the two makes
+         * most sense. */
+
+        if (statx(dirfd, strempty(name), flags|AT_STATX_DONT_SYNC, STATX_BTIME, &sx) >= 0 &&
+            (sx.stx_mask & STATX_BTIME) &&
+            sx.stx_btime.tv_sec != 0)
+                a = (usec_t) sx.stx_btime.tv_sec * USEC_PER_SEC +
+                        (usec_t) sx.stx_btime.tv_nsec / NSEC_PER_USEC;
+        else
+                a = USEC_INFINITY;
+
+        r = fgetxattrat_fake(dirfd, name, "user.crtime_usec", &le, sizeof(le), flags, &n);
+        if (r >= 0) {
+                if (n != sizeof(le))
+                        r = -EIO;
+                else
+                        r = parse_crtime(le, &b);
+        }
+        if (r < 0) {
+                if (a != USEC_INFINITY) {
+                        *ret = a;
+                        return 0;
+                }
+
+                return r;
+        }
+
+        if (a != USEC_INFINITY)
+                *ret = MIN(a, b);
+        else
+                *ret = b;
+
+        return 0;
+}
+
+int fd_getcrtime(int fd, usec_t *ret) {
+        return fd_getcrtime_at(fd, NULL, ret, AT_EMPTY_PATH);
+}
+
+int path_getcrtime(const char *p, usec_t *ret) {
+        return fd_getcrtime_at(AT_FDCWD, p, ret, 0);
+}
+
+int fd_setcrtime(int fd, usec_t usec) {
+        le64_t le;
+
+        assert(fd >= 0);
+
+        if (IN_SET(usec, 0, USEC_INFINITY))
+                usec = now(CLOCK_REALTIME);
+
+        le = htole64((uint64_t) usec);
+        if (fsetxattr(fd, "user.crtime_usec", &le, sizeof(le), 0) < 0)
+                return -errno;
+
+        return 0;
+}
diff --git a/src/basic/xattr-util.h b/src/basic/xattr-util.h
new file mode 100644
index 0000000..9fa85d7
--- /dev/null
+++ b/src/basic/xattr-util.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <sys/types.h>
+
+#include "time-util.h"
+
+int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink);
+int fgetxattr_malloc(int fd, const char *name, char **value);
+
+int fgetxattrat_fake(
+                int dirfd,
+                const char *filename,
+                const char *attribute,
+                void *value, size_t size,
+                int flags,
+                size_t *ret_size);
+
+int fd_setcrtime(int fd, usec_t usec);
+
+int fd_getcrtime(int fd, usec_t *usec);
+int path_getcrtime(const char *p, usec_t *usec);
+int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags);