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-rw-r--r--src/basic/util.c637
1 files changed, 637 insertions, 0 deletions
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");
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 12:31:16 +0000