Adding upstream version 252.22.upstream/252.22

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

1 files changed, 1890 insertions, 0 deletions

diff --git a/src/portable/portable.c b/src/portable/portable.c
new file mode 100644
index 0000000..70f9071
--- /dev/null
+++ b/src/portable/portable.c
@@ -0,0 +1,1890 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <linux/loop.h>
+
+#include "bus-common-errors.h"
+#include "bus-error.h"
+#include "chase-symlinks.h"
+#include "conf-files.h"
+#include "copy.h"
+#include "data-fd-util.h"
+#include "def.h"
+#include "dirent-util.h"
+#include "discover-image.h"
+#include "dissect-image.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "errno-list.h"
+#include "escape.h"
+#include "extension-release.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "install.h"
+#include "io-util.h"
+#include "locale-util.h"
+#include "loop-util.h"
+#include "mkdir.h"
+#include "nulstr-util.h"
+#include "os-util.h"
+#include "path-lookup.h"
+#include "portable.h"
+#include "process-util.h"
+#include "selinux-util.h"
+#include "set.h"
+#include "signal-util.h"
+#include "socket-util.h"
+#include "sort-util.h"
+#include "string-table.h"
+#include "strv.h"
+#include "tmpfile-util.h"
+#include "user-util.h"
+
+/* Markers used in the first line of our 20-portable.conf unit file drop-in to determine, that a) the unit file was
+ * dropped there by the portable service logic and b) for which image it was dropped there. */
+#define PORTABLE_DROPIN_MARKER_BEGIN "# Drop-in created for image '"
+#define PORTABLE_DROPIN_MARKER_END "', do not edit."
+
+static bool prefix_match(const char *unit, const char *prefix) {
+        const char *p;
+
+        p = startswith(unit, prefix);
+        if (!p)
+                return false;
+
+        /* Only respect prefixes followed by dash or dot or when there's a complete match */
+        return IN_SET(*p, '-', '.', '@', 0);
+}
+
+static bool unit_match(const char *unit, char **matches) {
+        const char *dot;
+
+        dot = strrchr(unit, '.');
+        if (!dot)
+                return false;
+
+        if (!STR_IN_SET(dot, ".service", ".socket", ".target", ".timer", ".path"))
+                return false;
+
+        /* Empty match expression means: everything */
+        if (strv_isempty(matches))
+                return true;
+
+        /* Otherwise, at least one needs to match */
+        STRV_FOREACH(i, matches)
+                if (prefix_match(unit, *i))
+                        return true;
+
+        return false;
+}
+
+static PortableMetadata *portable_metadata_new(const char *name, const char *path, const char *selinux_label, int fd) {
+        PortableMetadata *m;
+
+        m = malloc0(offsetof(PortableMetadata, name) + strlen(name) + 1);
+        if (!m)
+                return NULL;
+
+        /* In case of a layered attach, we want to remember which image the unit came from */
+        if (path) {
+                m->image_path = strdup(path);
+                if (!m->image_path)
+                        return mfree(m);
+        }
+
+        /* The metadata file might have SELinux labels, we need to carry them and reapply them */
+        if (!isempty(selinux_label)) {
+                m->selinux_label = strdup(selinux_label);
+                if (!m->selinux_label) {
+                        free(m->image_path);
+                        return mfree(m);
+                }
+        }
+
+        strcpy(m->name, name);
+        m->fd = fd;
+
+        return TAKE_PTR(m);
+}
+
+PortableMetadata *portable_metadata_unref(PortableMetadata *i) {
+        if (!i)
+                return NULL;
+
+        safe_close(i->fd);
+        free(i->source);
+        free(i->image_path);
+        free(i->selinux_label);
+
+        return mfree(i);
+}
+
+static int compare_metadata(PortableMetadata *const *x, PortableMetadata *const *y) {
+        return strcmp((*x)->name, (*y)->name);
+}
+
+int portable_metadata_hashmap_to_sorted_array(Hashmap *unit_files, PortableMetadata ***ret) {
+
+        _cleanup_free_ PortableMetadata **sorted = NULL;
+        PortableMetadata *item;
+        size_t k = 0;
+
+        sorted = new(PortableMetadata*, hashmap_size(unit_files));
+        if (!sorted)
+                return -ENOMEM;
+
+        HASHMAP_FOREACH(item, unit_files)
+                sorted[k++] = item;
+
+        assert(k == hashmap_size(unit_files));
+
+        typesafe_qsort(sorted, k, compare_metadata);
+
+        *ret = TAKE_PTR(sorted);
+        return 0;
+}
+
+static int send_one_fd_iov_with_data_fd(
+                int socket_fd,
+                const struct iovec *iov,
+                size_t iovlen,
+                int fd) {
+
+        _cleanup_close_ int data_fd = -1;
+
+        assert(iov || iovlen == 0);
+        assert(socket_fd >= 0);
+        assert(fd >= 0);
+
+        data_fd = copy_data_fd(fd);
+        if (data_fd < 0)
+                return data_fd;
+
+        return send_one_fd_iov(socket_fd, data_fd, iov, iovlen, 0);
+}
+
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(portable_metadata_hash_ops, char, string_hash_func, string_compare_func,
+                                              PortableMetadata, portable_metadata_unref);
+
+static int extract_now(
+                const char *where,
+                char **matches,
+                const char *image_name,
+                bool path_is_extension,
+                bool relax_extension_release_check,
+                int socket_fd,
+                PortableMetadata **ret_os_release,
+                Hashmap **ret_unit_files) {
+
+        _cleanup_hashmap_free_ Hashmap *unit_files = NULL;
+        _cleanup_(portable_metadata_unrefp) PortableMetadata *os_release = NULL;
+        _cleanup_(lookup_paths_free) LookupPaths paths = {};
+        _cleanup_close_ int os_release_fd = -1;
+        _cleanup_free_ char *os_release_path = NULL;
+        const char *os_release_id;
+        int r;
+
+        /* Extracts the metadata from a directory tree 'where'. Extracts two kinds of information: the /etc/os-release
+         * data, and all unit files matching the specified expression. Note that this function is called in two very
+         * different but also similar contexts. When the tool gets invoked on a directory tree, we'll process it
+         * directly, and in-process, and thus can return the requested data directly, via 'ret_os_release' and
+         * 'ret_unit_files'. However, if the tool is invoked on a raw disk image — which needs to be mounted first — we
+         * are invoked in a child process with private mounts and then need to send the collected data to our
+         * parent. To handle both cases in one call this function also gets a 'socket_fd' parameter, which when >= 0 is
+         * used to send the data to the parent. */
+
+        assert(where);
+
+        /* First, find os-release/extension-release and send it upstream (or just save it). */
+        if (path_is_extension) {
+                os_release_id = strjoina("/usr/lib/extension-release.d/extension-release.", image_name);
+                r = open_extension_release(where, image_name, relax_extension_release_check, &os_release_path, &os_release_fd);
+        } else {
+                os_release_id = "/etc/os-release";
+                r = open_os_release(where, &os_release_path, &os_release_fd);
+        }
+        if (r < 0)
+                log_debug_errno(r,
+                                "Couldn't acquire %s file, ignoring: %m",
+                                path_is_extension ? "extension-release " : "os-release");
+        else {
+                if (socket_fd >= 0) {
+                        struct iovec iov[] = {
+                                IOVEC_MAKE_STRING(os_release_id),
+                                IOVEC_MAKE((char *)"\0", sizeof(char)),
+                        };
+
+                        r = send_one_fd_iov_with_data_fd(socket_fd, iov, ELEMENTSOF(iov), os_release_fd);
+                        if (r < 0)
+                                return log_debug_errno(r, "Failed to send os-release file: %m");
+                }
+
+                if (ret_os_release) {
+                        os_release = portable_metadata_new(os_release_id, NULL, NULL, os_release_fd);
+                        if (!os_release)
+                                return -ENOMEM;
+
+                        os_release_fd = -1;
+                        os_release->source = TAKE_PTR(os_release_path);
+                }
+        }
+
+        /* Then, send unit file data to the parent (or/and add it to the hashmap). For that we use our usual unit
+         * discovery logic. Note that we force looking inside of /lib/systemd/system/ for units too, as we mightbe
+         * compiled for a split-usr system but the image might be a legacy-usr one. */
+        r = lookup_paths_init(&paths, LOOKUP_SCOPE_SYSTEM, LOOKUP_PATHS_SPLIT_USR, where);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to acquire lookup paths: %m");
+
+        unit_files = hashmap_new(&portable_metadata_hash_ops);
+        if (!unit_files)
+                return -ENOMEM;
+
+        STRV_FOREACH(i, paths.search_path) {
+                _cleanup_free_ char *resolved = NULL;
+                _cleanup_closedir_ DIR *d = NULL;
+
+                r = chase_symlinks_and_opendir(*i, where, 0, &resolved, &d);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to open unit path '%s', ignoring: %m", *i);
+                        continue;
+                }
+
+                FOREACH_DIRENT(de, d, return log_debug_errno(errno, "Failed to read directory: %m")) {
+                        _cleanup_(portable_metadata_unrefp) PortableMetadata *m = NULL;
+                        _cleanup_(mac_selinux_freep) char *con = NULL;
+                        _cleanup_close_ int fd = -1;
+                        struct stat st;
+
+                        if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
+                                continue;
+
+                        if (!unit_match(de->d_name, matches))
+                                continue;
+
+                        /* Filter out duplicates */
+                        if (hashmap_get(unit_files, de->d_name))
+                                continue;
+
+                        if (!IN_SET(de->d_type, DT_LNK, DT_REG))
+                                continue;
+
+                        fd = openat(dirfd(d), de->d_name, O_CLOEXEC|O_RDONLY);
+                        if (fd < 0) {
+                                log_debug_errno(errno, "Failed to open unit file '%s', ignoring: %m", de->d_name);
+                                continue;
+                        }
+
+                        /* Reject empty files, just in case */
+                        if (fstat(fd, &st) < 0) {
+                                log_debug_errno(errno, "Failed to stat unit file '%s', ignoring: %m", de->d_name);
+                                continue;
+                        }
+
+                        if (st.st_size <= 0) {
+                                log_debug("Unit file '%s' is empty, ignoring.", de->d_name);
+                                continue;
+                        }
+
+#if HAVE_SELINUX
+                        /* The units will be copied on the host's filesystem, so if they had a SELinux label
+                         * we have to preserve it. Copy it out so that it can be applied later. */
+
+                        r = fgetfilecon_raw(fd, &con);
+                        if (r < 0 && !ERRNO_IS_XATTR_ABSENT(errno))
+                                log_debug_errno(errno, "Failed to get SELinux file context from '%s', ignoring: %m", de->d_name);
+#endif
+
+                        if (socket_fd >= 0) {
+                                struct iovec iov[] = {
+                                        IOVEC_MAKE_STRING(de->d_name),
+                                        IOVEC_MAKE((char *)"\0", sizeof(char)),
+                                        IOVEC_MAKE_STRING(strempty(con)),
+                                };
+
+                                r = send_one_fd_iov_with_data_fd(socket_fd, iov, ELEMENTSOF(iov), fd);
+                                if (r < 0)
+                                        return log_debug_errno(r, "Failed to send unit metadata to parent: %m");
+                        }
+
+                        m = portable_metadata_new(de->d_name, where, con, fd);
+                        if (!m)
+                                return -ENOMEM;
+                        fd = -1;
+
+                        m->source = path_join(resolved, de->d_name);
+                        if (!m->source)
+                                return -ENOMEM;
+
+                        r = hashmap_put(unit_files, m->name, m);
+                        if (r < 0)
+                                return log_debug_errno(r, "Failed to add unit to hashmap: %m");
+                        m = NULL;
+                }
+        }
+
+        if (ret_os_release)
+                *ret_os_release = TAKE_PTR(os_release);
+        if (ret_unit_files)
+                *ret_unit_files = TAKE_PTR(unit_files);
+
+        return 0;
+}
+
+static int portable_extract_by_path(
+                const char *path,
+                bool path_is_extension,
+                bool relax_extension_release_check,
+                char **matches,
+                PortableMetadata **ret_os_release,
+                Hashmap **ret_unit_files,
+                sd_bus_error *error) {
+
+        _cleanup_hashmap_free_ Hashmap *unit_files = NULL;
+        _cleanup_(portable_metadata_unrefp) PortableMetadata* os_release = NULL;
+        _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
+        int r;
+
+        assert(path);
+
+        r = loop_device_make_by_path(path, O_RDONLY, LO_FLAGS_PARTSCAN, LOCK_SH, &d);
+        if (r == -EISDIR) {
+                _cleanup_free_ char *image_name = NULL;
+
+                /* We can't turn this into a loop-back block device, and this returns EISDIR? Then this is a directory
+                 * tree and not a raw device. It's easy then. */
+
+                r = path_extract_filename(path, &image_name);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to extract image name from path '%s': %m", path);
+
+                r = extract_now(path, matches, image_name, path_is_extension, /* relax_extension_release_check= */ false, -1, &os_release, &unit_files);
+                if (r < 0)
+                        return r;
+
+        } else if (r < 0)
+                return log_debug_errno(r, "Failed to set up loopback device for %s: %m", path);
+        else {
+                _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
+                _cleanup_(rmdir_and_freep) char *tmpdir = NULL;
+                _cleanup_(close_pairp) int seq[2] = { -1, -1 };
+                _cleanup_(sigkill_waitp) pid_t child = 0;
+
+                /* We now have a loopback block device, let's fork off a child in its own mount namespace, mount it
+                 * there, and extract the metadata we need. The metadata is sent from the child back to us. */
+
+                BLOCK_SIGNALS(SIGCHLD);
+
+                r = mkdtemp_malloc("/tmp/inspect-XXXXXX", &tmpdir);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to create temporary directory: %m");
+
+                r = dissect_loop_device(
+                                d,
+                                NULL, NULL,
+                                DISSECT_IMAGE_READ_ONLY |
+                                DISSECT_IMAGE_GENERIC_ROOT |
+                                DISSECT_IMAGE_REQUIRE_ROOT |
+                                DISSECT_IMAGE_DISCARD_ON_LOOP |
+                                DISSECT_IMAGE_RELAX_VAR_CHECK |
+                                DISSECT_IMAGE_USR_NO_ROOT |
+                                DISSECT_IMAGE_ADD_PARTITION_DEVICES |
+                                DISSECT_IMAGE_PIN_PARTITION_DEVICES,
+                                &m);
+                if (r == -ENOPKG)
+                        sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Couldn't identify a suitable partition table or file system in '%s'.", path);
+                else if (r == -EADDRNOTAVAIL)
+                        sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "No root partition for specified root hash found in '%s'.", path);
+                else if (r == -ENOTUNIQ)
+                        sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Multiple suitable root partitions found in image '%s'.", path);
+                else if (r == -ENXIO)
+                        sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "No suitable root partition found in image '%s'.", path);
+                else if (r == -EPROTONOSUPPORT)
+                        sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Device '%s' is loopback block device with partition scanning turned off, please turn it on.", path);
+                if (r < 0)
+                        return r;
+
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, seq) < 0)
+                        return log_debug_errno(errno, "Failed to allocated SOCK_SEQPACKET socket: %m");
+
+                r = safe_fork("(sd-dissect)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE|FORK_LOG, &child);
+                if (r < 0)
+                        return r;
+                if (r == 0) {
+                        DissectImageFlags flags = DISSECT_IMAGE_READ_ONLY;
+
+                        seq[0] = safe_close(seq[0]);
+
+                        if (path_is_extension)
+                                flags |= DISSECT_IMAGE_VALIDATE_OS_EXT | (relax_extension_release_check ? DISSECT_IMAGE_RELAX_SYSEXT_CHECK : 0);
+                        else
+                                flags |= DISSECT_IMAGE_VALIDATE_OS;
+
+                        r = dissected_image_mount(m, tmpdir, UID_INVALID, UID_INVALID, flags);
+                        if (r < 0) {
+                                log_debug_errno(r, "Failed to mount dissected image: %m");
+                                goto child_finish;
+                        }
+
+                        r = extract_now(tmpdir, matches, m->image_name, path_is_extension, relax_extension_release_check, seq[1], NULL, NULL);
+
+                child_finish:
+                        _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+                }
+
+                seq[1] = safe_close(seq[1]);
+
+                unit_files = hashmap_new(&portable_metadata_hash_ops);
+                if (!unit_files)
+                        return -ENOMEM;
+
+                for (;;) {
+                        _cleanup_(portable_metadata_unrefp) PortableMetadata *add = NULL;
+                        _cleanup_close_ int fd = -1;
+                        /* We use NAME_MAX space for the SELinux label here. The kernel currently enforces no limit, but
+                         * according to suggestions from the SELinux people this will change and it will probably be
+                         * identical to NAME_MAX. For now we use that, but this should be updated one day when the final
+                         * limit is known. */
+                        char iov_buffer[PATH_MAX + NAME_MAX + 2];
+                        struct iovec iov = IOVEC_INIT(iov_buffer, sizeof(iov_buffer));
+
+                        ssize_t n = receive_one_fd_iov(seq[0], &iov, 1, 0, &fd);
+                        if (n == -EIO)
+                                break;
+                        if (n < 0)
+                                return log_debug_errno(n, "Failed to receive item: %m");
+                        iov_buffer[n] = 0;
+
+                        /* We can't really distinguish a zero-length datagram without any fds from EOF (both are signalled the
+                         * same way by recvmsg()). Hence, accept either as end notification. */
+                        if (isempty(iov_buffer) && fd < 0)
+                                break;
+
+                        if (isempty(iov_buffer) || fd < 0)
+                                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Invalid item sent from child.");
+
+                        /* Given recvmsg cannot be used with multiple io vectors if you don't know the size in advance,
+                         * use a marker to separate the name and the optional SELinux context. */
+                        char *selinux_label = memchr(iov_buffer, 0, n);
+                        assert(selinux_label);
+                        selinux_label++;
+
+                        add = portable_metadata_new(iov_buffer, path, selinux_label, fd);
+                        if (!add)
+                                return -ENOMEM;
+                        fd = -1;
+
+                        /* Note that we do not initialize 'add->source' here, as the source path is not usable here as
+                         * it refers to a path only valid in the short-living namespaced child process we forked
+                         * here. */
+
+                        if (PORTABLE_METADATA_IS_UNIT(add)) {
+                                r = hashmap_put(unit_files, add->name, add);
+                                if (r < 0)
+                                        return log_debug_errno(r, "Failed to add item to unit file list: %m");
+
+                                add = NULL;
+
+                        } else if (PORTABLE_METADATA_IS_OS_RELEASE(add) || PORTABLE_METADATA_IS_EXTENSION_RELEASE(add)) {
+
+                                assert(!os_release);
+                                os_release = TAKE_PTR(add);
+                        } else
+                                assert_not_reached();
+                }
+
+                r = wait_for_terminate_and_check("(sd-dissect)", child, 0);
+                if (r < 0)
+                        return r;
+                child = 0;
+        }
+
+        if (!os_release)
+                return sd_bus_error_setf(error,
+                                         SD_BUS_ERROR_INVALID_ARGS,
+                                         "Image '%s' lacks %s data, refusing.",
+                                         path,
+                                         path_is_extension ? "extension-release" : "os-release");
+
+        if (ret_unit_files)
+                *ret_unit_files = TAKE_PTR(unit_files);
+
+        if (ret_os_release)
+                *ret_os_release = TAKE_PTR(os_release);
+
+        return 0;
+}
+
+static int extract_image_and_extensions(
+                const char *name_or_path,
+                char **matches,
+                char **extension_image_paths,
+                bool validate_sysext,
+                bool relax_extension_release_check,
+                Image **ret_image,
+                OrderedHashmap **ret_extension_images,
+                OrderedHashmap **ret_extension_releases,
+                PortableMetadata **ret_os_release,
+                Hashmap **ret_unit_files,
+                char ***ret_valid_prefixes,
+                sd_bus_error *error) {
+
+        _cleanup_free_ char *id = NULL, *version_id = NULL, *sysext_level = NULL;
+        _cleanup_(portable_metadata_unrefp) PortableMetadata *os_release = NULL;
+        _cleanup_ordered_hashmap_free_ OrderedHashmap *extension_images = NULL, *extension_releases = NULL;
+        _cleanup_hashmap_free_ Hashmap *unit_files = NULL;
+        _cleanup_strv_free_ char **valid_prefixes = NULL;
+        _cleanup_(image_unrefp) Image *image = NULL;
+        Image *ext;
+        int r;
+
+        assert(name_or_path);
+
+        r = image_find_harder(IMAGE_PORTABLE, name_or_path, NULL, &image);
+        if (r < 0)
+                return r;
+
+        if (!strv_isempty(extension_image_paths)) {
+                extension_images = ordered_hashmap_new(&image_hash_ops);
+                if (!extension_images)
+                        return -ENOMEM;
+
+                if (ret_extension_releases) {
+                        extension_releases = ordered_hashmap_new(&portable_metadata_hash_ops);
+                        if (!extension_releases)
+                                return -ENOMEM;
+                }
+
+                STRV_FOREACH(p, extension_image_paths) {
+                        _cleanup_(image_unrefp) Image *new = NULL;
+
+                        r = image_find_harder(IMAGE_PORTABLE, *p, NULL, &new);
+                        if (r < 0)
+                                return r;
+
+                        r = ordered_hashmap_put(extension_images, new->name, new);
+                        if (r < 0)
+                                return r;
+                        TAKE_PTR(new);
+                }
+        }
+
+        r = portable_extract_by_path(image->path, /* path_is_extension= */ false, /* relax_extension_release_check= */ false, matches, &os_release, &unit_files, error);
+        if (r < 0)
+                return r;
+
+        /* If we are layering extension images on top of a runtime image, check that the os-release and
+         * extension-release metadata match, otherwise reject it immediately as invalid, or it will fail when
+         * the units are started. Also, collect valid portable prefixes if caller requested that. */
+        if (validate_sysext || ret_valid_prefixes) {
+                _cleanup_fclose_ FILE *f = NULL;
+                _cleanup_free_ char *prefixes = NULL;
+
+                r = take_fdopen_unlocked(&os_release->fd, "r", &f);
+                if (r < 0)
+                        return r;
+
+                r = parse_env_file(f, os_release->name,
+                                   "ID", &id,
+                                   "VERSION_ID", &version_id,
+                                   "SYSEXT_LEVEL", &sysext_level,
+                                   "PORTABLE_PREFIXES", &prefixes);
+                if (r < 0)
+                        return r;
+                if (isempty(id))
+                        return sd_bus_error_set_errnof(error, SYNTHETIC_ERRNO(ESTALE), "Image %s os-release metadata lacks the ID field", name_or_path);
+
+                if (prefixes) {
+                        valid_prefixes = strv_split(prefixes, WHITESPACE);
+                        if (!valid_prefixes)
+                                return -ENOMEM;
+                }
+        }
+
+        ORDERED_HASHMAP_FOREACH(ext, extension_images) {
+                _cleanup_(portable_metadata_unrefp) PortableMetadata *extension_release_meta = NULL;
+                _cleanup_hashmap_free_ Hashmap *extra_unit_files = NULL;
+                _cleanup_strv_free_ char **extension_release = NULL;
+                _cleanup_close_ int extension_release_fd = -1;
+                _cleanup_fclose_ FILE *f = NULL;
+                const char *e;
+
+                r = portable_extract_by_path(ext->path, /* path_is_extension= */ true, relax_extension_release_check, matches, &extension_release_meta, &extra_unit_files, error);
+                if (r < 0)
+                        return r;
+
+                r = hashmap_move(unit_files, extra_unit_files);
+                if (r < 0)
+                        return r;
+
+                if (!validate_sysext && !ret_valid_prefixes && !ret_extension_releases)
+                        continue;
+
+                /* We need to keep the fd valid, to return the PortableMetadata to the caller. */
+                extension_release_fd = fd_reopen(extension_release_meta->fd, O_CLOEXEC|O_RDONLY);
+                if (extension_release_fd < 0)
+                        return extension_release_fd;
+
+                r = take_fdopen_unlocked(&extension_release_fd, "r", &f);
+                if (r < 0)
+                        return r;
+
+                r = load_env_file_pairs(f, extension_release_meta->name, &extension_release);
+                if (r < 0)
+                        return r;
+
+                if (validate_sysext) {
+                        r = extension_release_validate(ext->path, id, version_id, sysext_level, "portable", extension_release);
+                        if (r == 0)
+                                return sd_bus_error_set_errnof(error, SYNTHETIC_ERRNO(ESTALE), "Image %s extension-release metadata does not match the root's", ext->path);
+                        if (r < 0)
+                                return sd_bus_error_set_errnof(error, r, "Failed to compare image %s extension-release metadata with the root's os-release: %m", ext->path);
+                }
+
+                e = strv_env_pairs_get(extension_release, "PORTABLE_PREFIXES");
+                if (e) {
+                        _cleanup_strv_free_ char **l = NULL;
+
+                        l = strv_split(e, WHITESPACE);
+                        if (!l)
+                                return -ENOMEM;
+
+                        r = strv_extend_strv(&valid_prefixes, l, true);
+                        if (r < 0)
+                                return r;
+                }
+
+                if (ret_extension_releases) {
+                        r = ordered_hashmap_put(extension_releases, ext->name, extension_release_meta);
+                        if (r < 0)
+                                return r;
+                        TAKE_PTR(extension_release_meta);
+                }
+        }
+
+        strv_sort(valid_prefixes);
+
+        if (ret_image)
+                *ret_image = TAKE_PTR(image);
+        if (ret_extension_images)
+                *ret_extension_images = TAKE_PTR(extension_images);
+        if (ret_extension_releases)
+                *ret_extension_releases = TAKE_PTR(extension_releases);
+        if (ret_os_release)
+                *ret_os_release = TAKE_PTR(os_release);
+        if (ret_unit_files)
+                *ret_unit_files = TAKE_PTR(unit_files);
+        if (ret_valid_prefixes)
+                *ret_valid_prefixes = TAKE_PTR(valid_prefixes);
+
+        return 0;
+}
+
+int portable_extract(
+                const char *name_or_path,
+                char **matches,
+                char **extension_image_paths,
+                PortableFlags flags,
+                PortableMetadata **ret_os_release,
+                OrderedHashmap **ret_extension_releases,
+                Hashmap **ret_unit_files,
+                char ***ret_valid_prefixes,
+                sd_bus_error *error) {
+
+        _cleanup_(portable_metadata_unrefp) PortableMetadata *os_release = NULL;
+        _cleanup_ordered_hashmap_free_ OrderedHashmap *extension_images = NULL, *extension_releases = NULL;
+        _cleanup_hashmap_free_ Hashmap *unit_files = NULL;
+        _cleanup_(strv_freep) char **valid_prefixes = NULL;
+        _cleanup_(image_unrefp) Image *image = NULL;
+        int r;
+
+        assert(name_or_path);
+
+        r = extract_image_and_extensions(
+                        name_or_path,
+                        matches,
+                        extension_image_paths,
+                        /* validate_sysext= */ false,
+                        /* relax_extension_release_check= */ FLAGS_SET(flags, PORTABLE_FORCE_SYSEXT),
+                        &image,
+                        &extension_images,
+                        &extension_releases,
+                        &os_release,
+                        &unit_files,
+                        ret_valid_prefixes ? &valid_prefixes : NULL,
+                        error);
+        if (r < 0)
+                return r;
+
+        if (hashmap_isempty(unit_files)) {
+                _cleanup_free_ char *extensions = strv_join(extension_image_paths, ", ");
+                if (!extensions)
+                        return -ENOMEM;
+
+                return sd_bus_error_setf(error,
+                                         SD_BUS_ERROR_INVALID_ARGS,
+                                         "Couldn't find any matching unit files in image '%s%s%s', refusing.",
+                                         image->path,
+                                         isempty(extensions) ? "" : "' or any of its extensions '",
+                                         isempty(extensions) ? "" : extensions);
+        }
+
+        if (ret_os_release)
+                *ret_os_release = TAKE_PTR(os_release);
+        if (ret_extension_releases)
+                *ret_extension_releases = TAKE_PTR(extension_releases);
+        if (ret_unit_files)
+                *ret_unit_files = TAKE_PTR(unit_files);
+        if (ret_valid_prefixes)
+                *ret_valid_prefixes = TAKE_PTR(valid_prefixes);
+
+        return 0;
+}
+
+static int unit_file_is_active(
+                sd_bus *bus,
+                const char *name,
+                sd_bus_error *error) {
+
+        static const char *const active_states[] = {
+                "activating",
+                "active",
+                "reloading",
+                "deactivating",
+                NULL,
+        };
+        int r;
+
+        if (!bus)
+                return false;
+
+        /* If we are looking at a plain or instance things are easy, we can just query the state */
+        if (unit_name_is_valid(name, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE)) {
+                _cleanup_free_ char *path = NULL, *buf = NULL;
+
+                path = unit_dbus_path_from_name(name);
+                if (!path)
+                        return -ENOMEM;
+
+                r = sd_bus_get_property_string(
+                                bus,
+                                "org.freedesktop.systemd1",
+                                path,
+                                "org.freedesktop.systemd1.Unit",
+                                "ActiveState",
+                                error,
+                                &buf);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to retrieve unit state: %s", bus_error_message(error, r));
+
+                return strv_contains((char**) active_states, buf);
+        }
+
+        /* Otherwise we need to enumerate. But let's build the most restricted query we can */
+        if (unit_name_is_valid(name, UNIT_NAME_TEMPLATE)) {
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL, *reply = NULL;
+                const char *at, *prefix, *joined;
+
+                r = sd_bus_message_new_method_call(
+                                bus,
+                                &m,
+                                "org.freedesktop.systemd1",
+                                "/org/freedesktop/systemd1",
+                                "org.freedesktop.systemd1.Manager",
+                                "ListUnitsByPatterns");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append_strv(m, (char**) active_states);
+                if (r < 0)
+                        return r;
+
+                at = strchr(name, '@');
+                assert(at);
+
+                prefix = strndupa_safe(name, at + 1 - name);
+                joined = strjoina(prefix, "*", at + 1);
+
+                r = sd_bus_message_append_strv(m, STRV_MAKE(joined));
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_call(bus, m, 0, error, &reply);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to list units: %s", bus_error_message(error, r));
+
+                r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_ARRAY, "(ssssssouso)");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_STRUCT, "ssssssouso");
+                if (r < 0)
+                        return r;
+
+                return r > 0;
+        }
+
+        return -EINVAL;
+}
+
+static int portable_changes_add(
+                PortableChange **changes,
+                size_t *n_changes,
+                int type_or_errno, /* PORTABLE_COPY, PORTABLE_SYMLINK, … if positive, or errno if negative */
+                const char *path,
+                const char *source) {
+
+        _cleanup_free_ char *p = NULL, *s = NULL;
+        PortableChange *c;
+
+        assert(path);
+        assert(!changes == !n_changes);
+
+        if (type_or_errno >= 0)
+                assert(type_or_errno < _PORTABLE_CHANGE_TYPE_MAX);
+        else
+                assert(type_or_errno >= -ERRNO_MAX);
+
+        if (!changes)
+                return 0;
+
+        c = reallocarray(*changes, *n_changes + 1, sizeof(PortableChange));
+        if (!c)
+                return -ENOMEM;
+        *changes = c;
+
+        p = strdup(path);
+        if (!p)
+                return -ENOMEM;
+
+        path_simplify(p);
+
+        if (source) {
+                s = strdup(source);
+                if (!s)
+                        return -ENOMEM;
+
+                path_simplify(s);
+        }
+
+        c[(*n_changes)++] = (PortableChange) {
+                .type_or_errno = type_or_errno,
+                .path = TAKE_PTR(p),
+                .source = TAKE_PTR(s),
+        };
+
+        return 0;
+}
+
+static int portable_changes_add_with_prefix(
+                PortableChange **changes,
+                size_t *n_changes,
+                int type_or_errno,
+                const char *prefix,
+                const char *path,
+                const char *source) {
+
+        _cleanup_free_ char *path_buf = NULL, *source_buf = NULL;
+
+        assert(path);
+        assert(!changes == !n_changes);
+
+        if (!changes)
+                return 0;
+
+        if (prefix) {
+                path_buf = path_join(prefix, path);
+                if (!path_buf)
+                        return -ENOMEM;
+
+                path = path_buf;
+
+                if (source) {
+                        source_buf = path_join(prefix, source);
+                        if (!source_buf)
+                                return -ENOMEM;
+
+                        source = source_buf;
+                }
+        }
+
+        return portable_changes_add(changes, n_changes, type_or_errno, path, source);
+}
+
+void portable_changes_free(PortableChange *changes, size_t n_changes) {
+        size_t i;
+
+        assert(changes || n_changes == 0);
+
+        for (i = 0; i < n_changes; i++) {
+                free(changes[i].path);
+                free(changes[i].source);
+        }
+
+        free(changes);
+}
+
+static const char *root_setting_from_image(ImageType type) {
+        return IN_SET(type, IMAGE_DIRECTORY, IMAGE_SUBVOLUME) ? "RootDirectory=" : "RootImage=";
+}
+
+static const char *extension_setting_from_image(ImageType type) {
+        return IN_SET(type, IMAGE_DIRECTORY, IMAGE_SUBVOLUME) ? "ExtensionDirectories=" : "ExtensionImages=";
+}
+
+static int make_marker_text(const char *image_path, OrderedHashmap *extension_images, char **ret_text) {
+        _cleanup_free_ char *text = NULL, *escaped_image_path = NULL;
+        Image *ext;
+
+        assert(image_path);
+        assert(ret_text);
+
+        escaped_image_path = xescape(image_path, ":");
+        if (!escaped_image_path)
+                return -ENOMEM;
+
+        /* If the image is layered, include all layers in the marker as a colon-separated
+         * list of paths, so that we can do exact matches on removal. */
+        text = strjoin(PORTABLE_DROPIN_MARKER_BEGIN, escaped_image_path);
+        if (!text)
+                return -ENOMEM;
+
+        ORDERED_HASHMAP_FOREACH(ext, extension_images) {
+                _cleanup_free_ char *escaped = NULL;
+
+                escaped = xescape(ext->path, ":");
+                if (!escaped)
+                        return -ENOMEM;
+
+                if (!strextend(&text, ":", escaped))
+                        return -ENOMEM;
+        }
+
+        if (!strextend(&text, PORTABLE_DROPIN_MARKER_END "\n"))
+                return -ENOMEM;
+
+        *ret_text = TAKE_PTR(text);
+        return 0;
+}
+
+static int install_chroot_dropin(
+                const char *image_path,
+                ImageType type,
+                OrderedHashmap *extension_images,
+                const PortableMetadata *m,
+                const char *dropin_dir,
+                PortableFlags flags,
+                char **ret_dropin,
+                PortableChange **changes,
+                size_t *n_changes) {
+
+        _cleanup_free_ char *text = NULL, *dropin = NULL;
+        int r;
+
+        assert(image_path);
+        assert(m);
+        assert(dropin_dir);
+
+        dropin = path_join(dropin_dir, "20-portable.conf");
+        if (!dropin)
+                return -ENOMEM;
+
+        r = make_marker_text(image_path, extension_images, &text);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to generate marker string for portable drop-in: %m");
+
+        if (endswith(m->name, ".service")) {
+                const char *os_release_source, *root_type;
+                _cleanup_free_ char *base_name = NULL;
+                Image *ext;
+
+                root_type = root_setting_from_image(type);
+
+                if (access("/etc/os-release", F_OK) < 0) {
+                        if (errno != ENOENT)
+                                return log_debug_errno(errno, "Failed to check if /etc/os-release exists: %m");
+
+                        os_release_source = "/usr/lib/os-release";
+                } else
+                        os_release_source = "/etc/os-release";
+
+                r = path_extract_filename(m->image_path ?: image_path, &base_name);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to extract basename from '%s': %m", m->image_path ?: image_path);
+
+                if (!strextend(&text,
+                               "\n"
+                               "[Service]\n",
+                               root_type, image_path, "\n"
+                               "Environment=PORTABLE=", base_name, "\n"
+                               "BindReadOnlyPaths=", os_release_source, ":/run/host/os-release\n"
+                               "LogExtraFields=PORTABLE=", base_name, "\n"))
+                        return -ENOMEM;
+
+                if (m->image_path && !path_equal(m->image_path, image_path))
+                        ORDERED_HASHMAP_FOREACH(ext, extension_images)
+                                if (!strextend(&text,
+                                               extension_setting_from_image(ext->type),
+                                               ext->path,
+                                               /* With --force tell PID1 to avoid enforcing that the image <name> and
+                                                * extension-release.<name> have to match. */
+                                               !IN_SET(type, IMAGE_DIRECTORY, IMAGE_SUBVOLUME) &&
+                                                   FLAGS_SET(flags, PORTABLE_FORCE_SYSEXT) ?
+                                                       ":x-systemd.relax-extension-release-check" :
+                                                       "",
+                                               "\n"))
+                                        return -ENOMEM;
+        }
+
+        r = write_string_file(dropin, text, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC|WRITE_STRING_FILE_SYNC);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to write '%s': %m", dropin);
+
+        (void) portable_changes_add(changes, n_changes, PORTABLE_WRITE, dropin, NULL);
+
+        if (ret_dropin)
+                *ret_dropin = TAKE_PTR(dropin);
+
+        return 0;
+}
+
+static int install_profile_dropin(
+                const char *image_path,
+                const PortableMetadata *m,
+                const char *dropin_dir,
+                const char *profile,
+                PortableFlags flags,
+                char **ret_dropin,
+                PortableChange **changes,
+                size_t *n_changes) {
+
+        _cleanup_free_ char *dropin = NULL, *from = NULL;
+        int r;
+
+        assert(image_path);
+        assert(m);
+        assert(dropin_dir);
+
+        if (!profile)
+                return 0;
+
+        r = find_portable_profile(profile, m->name, &from);
+        if (r < 0) {
+                if (r != -ENOENT)
+                        return log_debug_errno(errno, "Profile '%s' is not accessible: %m", profile);
+
+                log_debug_errno(errno, "Skipping link to profile '%s', as it does not exist: %m", profile);
+                return 0;
+        }
+
+        dropin = path_join(dropin_dir, "10-profile.conf");
+        if (!dropin)
+                return -ENOMEM;
+
+        if (flags & PORTABLE_PREFER_COPY) {
+
+                r = copy_file_atomic(from, dropin, 0644, 0, 0, COPY_REFLINK|COPY_FSYNC);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to copy %s %s %s: %m", from, special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), dropin);
+
+                (void) portable_changes_add(changes, n_changes, PORTABLE_COPY, dropin, from);
+
+        } else {
+
+                if (symlink(from, dropin) < 0)
+                        return log_debug_errno(errno, "Failed to link %s %s %s: %m", from, special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), dropin);
+
+                (void) portable_changes_add(changes, n_changes, PORTABLE_SYMLINK, dropin, from);
+        }
+
+        if (ret_dropin)
+                *ret_dropin = TAKE_PTR(dropin);
+
+        return 0;
+}
+
+static const char *attached_path(const LookupPaths *paths, PortableFlags flags) {
+        const char *where;
+
+        assert(paths);
+
+        if (flags & PORTABLE_RUNTIME)
+                where = paths->runtime_attached;
+        else
+                where = paths->persistent_attached;
+
+        assert(where);
+        return where;
+}
+
+static int attach_unit_file(
+                const LookupPaths *paths,
+                const char *image_path,
+                ImageType type,
+                OrderedHashmap *extension_images,
+                const PortableMetadata *m,
+                const char *profile,
+                PortableFlags flags,
+                PortableChange **changes,
+                size_t *n_changes) {
+
+        _cleanup_(unlink_and_freep) char *chroot_dropin = NULL, *profile_dropin = NULL;
+        _cleanup_(rmdir_and_freep) char *dropin_dir = NULL;
+        _cleanup_free_ char *path = NULL;
+        const char *where;
+        int r;
+
+        assert(paths);
+        assert(image_path);
+        assert(m);
+        assert(PORTABLE_METADATA_IS_UNIT(m));
+
+        where = attached_path(paths, flags);
+
+        (void) mkdir_parents(where, 0755);
+        if (mkdir(where, 0755) < 0) {
+                if (errno != EEXIST)
+                        return log_debug_errno(errno, "Failed to create attach directory %s: %m", where);
+        } else
+                (void) portable_changes_add(changes, n_changes, PORTABLE_MKDIR, where, NULL);
+
+        path = path_join(where, m->name);
+        if (!path)
+                return -ENOMEM;
+
+        dropin_dir = strjoin(path, ".d");
+        if (!dropin_dir)
+                return -ENOMEM;
+
+        if (mkdir(dropin_dir, 0755) < 0) {
+                if (errno != EEXIST)
+                        return log_debug_errno(errno, "Failed to create drop-in directory %s: %m", dropin_dir);
+        } else
+                (void) portable_changes_add(changes, n_changes, PORTABLE_MKDIR, dropin_dir, NULL);
+
+        /* We install the drop-ins first, and the actual unit file last to achieve somewhat atomic behaviour if PID 1
+         * is reloaded while we are creating things here: as long as only the drop-ins exist the unit doesn't exist at
+         * all for PID 1. */
+
+        r = install_chroot_dropin(image_path, type, extension_images, m, dropin_dir, flags, &chroot_dropin, changes, n_changes);
+        if (r < 0)
+                return r;
+
+        r = install_profile_dropin(image_path, m, dropin_dir, profile, flags, &profile_dropin, changes, n_changes);
+        if (r < 0)
+                return r;
+
+        if ((flags & PORTABLE_PREFER_SYMLINK) && m->source) {
+
+                if (symlink(m->source, path) < 0)
+                        return log_debug_errno(errno, "Failed to symlink unit file '%s': %m", path);
+
+                (void) portable_changes_add(changes, n_changes, PORTABLE_SYMLINK, path, m->source);
+
+        } else {
+                _cleanup_(unlink_and_freep) char *tmp = NULL;
+                _cleanup_close_ int fd = -1;
+
+                (void) mac_selinux_create_file_prepare_label(path, m->selinux_label);
+
+                fd = open_tmpfile_linkable(path, O_WRONLY|O_CLOEXEC, &tmp);
+                mac_selinux_create_file_clear(); /* Clear immediately in case of errors */
+                if (fd < 0)
+                        return log_debug_errno(fd, "Failed to create unit file '%s': %m", path);
+
+                r = copy_bytes(m->fd, fd, UINT64_MAX, COPY_REFLINK);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to copy unit file '%s': %m", path);
+
+                if (fchmod(fd, 0644) < 0)
+                        return log_debug_errno(errno, "Failed to change unit file access mode for '%s': %m", path);
+
+                r = link_tmpfile(fd, tmp, path);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to install unit file '%s': %m", path);
+
+                tmp = mfree(tmp);
+
+                (void) portable_changes_add(changes, n_changes, PORTABLE_COPY, path, m->source);
+        }
+
+        /* All is established now, now let's disable any rollbacks */
+        chroot_dropin = mfree(chroot_dropin);
+        profile_dropin = mfree(profile_dropin);
+        dropin_dir = mfree(dropin_dir);
+
+        return 0;
+}
+
+static int image_symlink(
+                const char *image_path,
+                PortableFlags flags,
+                char **ret) {
+
+        const char *fn, *where;
+        char *joined = NULL;
+
+        assert(image_path);
+        assert(ret);
+
+        fn = last_path_component(image_path);
+
+        if (flags & PORTABLE_RUNTIME)
+                where = "/run/portables/";
+        else
+                where = "/etc/portables/";
+
+        joined = strjoin(where, fn);
+        if (!joined)
+                return -ENOMEM;
+
+        *ret = joined;
+        return 0;
+}
+
+static int install_image_symlink(
+                const char *image_path,
+                PortableFlags flags,
+                PortableChange **changes,
+                size_t *n_changes) {
+
+        _cleanup_free_ char *sl = NULL;
+        int r;
+
+        assert(image_path);
+
+        /* If the image is outside of the image search also link it into it, so that it can be found with short image
+         * names and is listed among the images. */
+
+        if (image_in_search_path(IMAGE_PORTABLE, NULL, image_path))
+                return 0;
+
+        r = image_symlink(image_path, flags, &sl);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to generate image symlink path: %m");
+
+        (void) mkdir_parents(sl, 0755);
+
+        if (symlink(image_path, sl) < 0)
+                return log_debug_errno(errno, "Failed to link %s %s %s: %m", image_path, special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), sl);
+
+        (void) portable_changes_add(changes, n_changes, PORTABLE_SYMLINK, sl, image_path);
+        return 0;
+}
+
+static int install_image_and_extensions_symlinks(
+                const Image *image,
+                OrderedHashmap *extension_images,
+                PortableFlags flags,
+                PortableChange **changes,
+                size_t *n_changes) {
+
+        Image *ext;
+        int r;
+
+        assert(image);
+
+        ORDERED_HASHMAP_FOREACH(ext, extension_images) {
+                r = install_image_symlink(ext->path, flags, changes, n_changes);
+                if (r < 0)
+                        return r;
+        }
+
+        r = install_image_symlink(image->path, flags, changes, n_changes);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static bool prefix_matches_compatible(char **matches, char **valid_prefixes) {
+        /* Checks if all 'matches' are included in the list of 'valid_prefixes' */
+
+        STRV_FOREACH(m, matches)
+                if (!strv_contains(valid_prefixes, *m))
+                        return false;
+
+        return true;
+}
+
+int portable_attach(
+                sd_bus *bus,
+                const char *name_or_path,
+                char **matches,
+                const char *profile,
+                char **extension_image_paths,
+                PortableFlags flags,
+                PortableChange **changes,
+                size_t *n_changes,
+                sd_bus_error *error) {
+
+        _cleanup_ordered_hashmap_free_ OrderedHashmap *extension_images = NULL;
+        _cleanup_hashmap_free_ Hashmap *unit_files = NULL;
+        _cleanup_(lookup_paths_free) LookupPaths paths = {};
+        _cleanup_strv_free_ char **valid_prefixes = NULL;
+        _cleanup_(image_unrefp) Image *image = NULL;
+        PortableMetadata *item;
+        int r;
+
+        r = extract_image_and_extensions(
+                        name_or_path,
+                        matches,
+                        extension_image_paths,
+                        /* validate_sysext= */ true,
+                        /* relax_extension_release_check= */ FLAGS_SET(flags, PORTABLE_FORCE_SYSEXT),
+                        &image,
+                        &extension_images,
+                        /* extension_releases= */ NULL,
+                        /* os_release= */ NULL,
+                        &unit_files,
+                        &valid_prefixes,
+                        error);
+        if (r < 0)
+                return r;
+
+        if (valid_prefixes && !prefix_matches_compatible(matches, valid_prefixes)) {
+                _cleanup_free_ char *matches_joined = NULL, *extensions_joined = NULL, *valid_prefixes_joined = NULL;
+
+                matches_joined = strv_join(matches, "', '");
+                if (!matches_joined)
+                        return -ENOMEM;
+
+                extensions_joined = strv_join(extension_image_paths, ", ");
+                if (!extensions_joined)
+                        return -ENOMEM;
+
+                valid_prefixes_joined = strv_join(valid_prefixes, ", ");
+                if (!valid_prefixes_joined)
+                        return -ENOMEM;
+
+                return sd_bus_error_setf(
+                                error,
+                                SD_BUS_ERROR_INVALID_ARGS,
+                                "Selected matches '%s' are not compatible with portable service image '%s%s%s', refusing. (Acceptable prefix matches are: %s)",
+                                matches_joined,
+                                image->path,
+                                isempty(extensions_joined) ? "" : "' or any of its extensions '",
+                                strempty(extensions_joined),
+                                valid_prefixes_joined);
+        }
+
+        if (hashmap_isempty(unit_files)) {
+                _cleanup_free_ char *extensions_joined = strv_join(extension_image_paths, ", ");
+                if (!extensions_joined)
+                        return -ENOMEM;
+
+                return sd_bus_error_setf(
+                                error,
+                                SD_BUS_ERROR_INVALID_ARGS,
+                                "Couldn't find any matching unit files in image '%s%s%s', refusing.",
+                                image->path,
+                                isempty(extensions_joined) ? "" : "' or any of its extensions '",
+                                strempty(extensions_joined));
+        }
+
+        r = lookup_paths_init(&paths, LOOKUP_SCOPE_SYSTEM, LOOKUP_PATHS_SPLIT_USR, NULL);
+        if (r < 0)
+                return r;
+
+        if (!FLAGS_SET(flags, PORTABLE_REATTACH) && !FLAGS_SET(flags, PORTABLE_FORCE_ATTACH))
+                HASHMAP_FOREACH(item, unit_files) {
+                        r = unit_file_exists(LOOKUP_SCOPE_SYSTEM, &paths, item->name);
+                        if (r < 0)
+                                return sd_bus_error_set_errnof(error, r, "Failed to determine whether unit '%s' exists on the host: %m", item->name);
+                        if (r > 0)
+                                return sd_bus_error_setf(error, BUS_ERROR_UNIT_EXISTS, "Unit file '%s' exists on the host already, refusing.", item->name);
+
+                        r = unit_file_is_active(bus, item->name, error);
+                        if (r < 0)
+                                return r;
+                        if (r > 0)
+                                return sd_bus_error_setf(error, BUS_ERROR_UNIT_EXISTS, "Unit file '%s' is active already, refusing.", item->name);
+                }
+
+        HASHMAP_FOREACH(item, unit_files) {
+                r = attach_unit_file(&paths, image->path, image->type, extension_images,
+                                     item, profile, flags, changes, n_changes);
+                if (r < 0)
+                        return sd_bus_error_set_errnof(error, r, "Failed to attach unit '%s': %m", item->name);
+        }
+
+        /* We don't care too much for the image symlink, it's just a convenience thing, it's not necessary for proper
+         * operation otherwise. */
+        (void) install_image_and_extensions_symlinks(image, extension_images, flags, changes, n_changes);
+
+        return 0;
+}
+
+static bool marker_matches_images(const char *marker, const char *name_or_path, char **extension_image_paths) {
+        _cleanup_strv_free_ char **root_and_extensions = NULL;
+        const char *a;
+        int r;
+
+        assert(marker);
+        assert(name_or_path);
+
+        /* If extensions were used when attaching, the marker will be a colon-separated
+         * list of images/paths. We enforce strict 1:1 matching, so that we are sure
+         * we are detaching exactly what was attached.
+         * For each image, starting with the root, we look for a token in the marker,
+         * and return a negative answer on any non-matching combination. */
+
+        root_and_extensions = strv_new(name_or_path);
+        if (!root_and_extensions)
+                return -ENOMEM;
+
+        r = strv_extend_strv(&root_and_extensions, extension_image_paths, false);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(image_name_or_path, root_and_extensions) {
+                _cleanup_free_ char *image = NULL;
+
+                r = extract_first_word(&marker, &image, ":", EXTRACT_UNQUOTE|EXTRACT_RETAIN_ESCAPE);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to parse marker: %s", marker);
+                if (r == 0)
+                        return false;
+
+                a = last_path_component(image);
+
+                if (image_name_is_valid(*image_name_or_path)) {
+                        const char *e, *underscore;
+
+                        /* We shall match against an image name. In that case let's compare the last component, and optionally
+                        * allow either a suffix of ".raw" or a series of "/".
+                        * But allow matching on a different version of the same image, when a "_" is used as a separator. */
+                        underscore = strchr(*image_name_or_path, '_');
+                        if (underscore) {
+                                if (strneq(a, *image_name_or_path, underscore - *image_name_or_path))
+                                        continue;
+                                return false;
+                        }
+
+                        e = startswith(a, *image_name_or_path);
+                        if (!e)
+                                return false;
+
+                        if(!(e[strspn(e, "/")] == 0 || streq(e, ".raw")))
+                                return false;
+                } else {
+                        const char *b, *underscore;
+                        size_t l;
+
+                        /* We shall match against a path. Let's ignore any prefix here though, as often there are many ways to
+                         * reach the same file. However, in this mode, let's validate any file suffix.
+                         * But also ensure that we don't fail if both components don't have a '/' at all
+                         * (strcspn returns the full length of the string in that case, which might not
+                         * match as the versions might differ). */
+
+                        l = strcspn(a, "/");
+                        b = last_path_component(*image_name_or_path);
+
+                        if ((a[l] != '/') != !strchr(b, '/')) /* One is a directory, the other is not */
+                                return false;
+
+                        if (a[l] != 0 && strcspn(b, "/") != l)
+                                return false;
+
+                        underscore = strchr(b, '_');
+                        if (underscore)
+                                l = underscore - b;
+                        else { /* Either component could be versioned */
+                                underscore = strchr(a, '_');
+                                if (underscore)
+                                        l = underscore - a;
+                        }
+
+                        if (!strneq(a, b, l))
+                                return false;
+                }
+        }
+
+        return true;
+}
+
+static int test_chroot_dropin(
+                DIR *d,
+                const char *where,
+                const char *fname,
+                const char *name_or_path,
+                char **extension_image_paths,
+                char **ret_marker) {
+
+        _cleanup_free_ char *line = NULL, *marker = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_close_ int fd = -1;
+        const char *p, *e, *k;
+        int r;
+
+        assert(d);
+        assert(where);
+        assert(fname);
+
+        /* We recognize unis created from portable images via the drop-in we created for them */
+
+        p = strjoina(fname, ".d/20-portable.conf");
+        fd = openat(dirfd(d), p, O_RDONLY|O_CLOEXEC);
+        if (fd < 0) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_debug_errno(errno, "Failed to open %s/%s: %m", where, p);
+        }
+
+        r = take_fdopen_unlocked(&fd, "r", &f);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to convert file handle: %m");
+
+        r = read_line(f, LONG_LINE_MAX, &line);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to read from %s/%s: %m", where, p);
+
+        e = startswith(line, PORTABLE_DROPIN_MARKER_BEGIN);
+        if (!e)
+                return 0;
+
+        k = endswith(e, PORTABLE_DROPIN_MARKER_END);
+        if (!k)
+                return 0;
+
+        marker = strndup(e, k - e);
+        if (!marker)
+                return -ENOMEM;
+
+        if (!name_or_path)
+                r = true;
+        else
+                r = marker_matches_images(marker, name_or_path, extension_image_paths);
+
+        if (ret_marker)
+                *ret_marker = TAKE_PTR(marker);
+
+        return r;
+}
+
+int portable_detach(
+                sd_bus *bus,
+                const char *name_or_path,
+                char **extension_image_paths,
+                PortableFlags flags,
+                PortableChange **changes,
+                size_t *n_changes,
+                sd_bus_error *error) {
+
+        _cleanup_(lookup_paths_free) LookupPaths paths = {};
+        _cleanup_set_free_ Set *unit_files = NULL, *markers = NULL;
+        _cleanup_free_ char *extensions = NULL;
+        _cleanup_closedir_ DIR *d = NULL;
+        const char *where, *item;
+        int ret = 0;
+        int r;
+
+        assert(name_or_path);
+
+        r = lookup_paths_init(&paths, LOOKUP_SCOPE_SYSTEM, LOOKUP_PATHS_SPLIT_USR, NULL);
+        if (r < 0)
+                return r;
+
+        where = attached_path(&paths, flags);
+
+        d = opendir(where);
+        if (!d) {
+                if (errno == ENOENT)
+                        goto not_found;
+
+                return log_debug_errno(errno, "Failed to open '%s' directory: %m", where);
+        }
+
+        FOREACH_DIRENT(de, d, return log_debug_errno(errno, "Failed to enumerate '%s' directory: %m", where)) {
+                _cleanup_free_ char *marker = NULL, *unit_name = NULL;
+                const char *dot;
+
+                /* When a portable service is enabled with "portablectl --copy=symlink --enable --now attach",
+                 * and is disabled with "portablectl --enable --now detach", which calls DisableUnitFilesWithFlags
+                 * DBus method, the main unit file is removed, but its drop-ins are not. Hence, here we need
+                 * to list both main unit files and drop-in directories (without the main unit files). */
+
+                dot = endswith(de->d_name, ".d");
+                if (dot)
+                        unit_name = strndup(de->d_name, dot - de->d_name);
+                else
+                        unit_name = strdup(de->d_name);
+                if (!unit_name)
+                        return -ENOMEM;
+
+                if (!unit_name_is_valid(unit_name, UNIT_NAME_ANY))
+                        continue;
+
+                /* Filter out duplicates */
+                if (set_contains(unit_files, unit_name))
+                        continue;
+
+                if (dot ? !IN_SET(de->d_type, DT_LNK, DT_DIR) : !IN_SET(de->d_type, DT_LNK, DT_REG))
+                        continue;
+
+                r = test_chroot_dropin(d, where, unit_name, name_or_path, extension_image_paths, &marker);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        continue;
+
+                if (!FLAGS_SET(flags, PORTABLE_REATTACH) && !FLAGS_SET(flags, PORTABLE_FORCE_ATTACH)) {
+                        r = unit_file_is_active(bus, unit_name, error);
+                        if (r < 0)
+                                return r;
+                        if (r > 0)
+                                return sd_bus_error_setf(error, BUS_ERROR_UNIT_EXISTS, "Unit file '%s' is active, can't detach.", unit_name);
+                }
+
+                r = set_ensure_consume(&unit_files, &string_hash_ops_free, TAKE_PTR(unit_name));
+                if (r < 0)
+                        return log_oom_debug();
+
+                for (const char *p = marker;;) {
+                        _cleanup_free_ char *image = NULL;
+
+                        r = extract_first_word(&p, &image, ":", EXTRACT_UNESCAPE_SEPARATORS|EXTRACT_RETAIN_ESCAPE);
+                        if (r < 0)
+                                return log_debug_errno(r, "Failed to parse marker: %s", p);
+                        if (r == 0)
+                                break;
+
+                        if (path_is_absolute(image) && !image_in_search_path(IMAGE_PORTABLE, NULL, image)) {
+                                r = set_ensure_consume(&markers, &path_hash_ops_free, TAKE_PTR(image));
+                                if (r < 0)
+                                        return r;
+                        }
+                }
+        }
+
+        if (set_isempty(unit_files))
+                goto not_found;
+
+        SET_FOREACH(item, unit_files) {
+                _cleanup_free_ char *md = NULL;
+
+                if (unlinkat(dirfd(d), item, 0) < 0) {
+                        log_debug_errno(errno, "Can't remove unit file %s/%s: %m", where, item);
+
+                        if (errno != ENOENT && ret >= 0)
+                                ret = -errno;
+                } else
+                        portable_changes_add_with_prefix(changes, n_changes, PORTABLE_UNLINK, where, item, NULL);
+
+                FOREACH_STRING(suffix, ".d/10-profile.conf", ".d/20-portable.conf") {
+                        _cleanup_free_ char *dropin = NULL;
+
+                        dropin = strjoin(item, suffix);
+                        if (!dropin)
+                                return -ENOMEM;
+
+                        if (unlinkat(dirfd(d), dropin, 0) < 0) {
+                                log_debug_errno(errno, "Can't remove drop-in %s/%s: %m", where, dropin);
+
+                                if (errno != ENOENT && ret >= 0)
+                                        ret = -errno;
+                        } else
+                                portable_changes_add_with_prefix(changes, n_changes, PORTABLE_UNLINK, where, dropin, NULL);
+                }
+
+                md = strjoin(item, ".d");
+                if (!md)
+                        return -ENOMEM;
+
+                if (unlinkat(dirfd(d), md, AT_REMOVEDIR) < 0) {
+                        log_debug_errno(errno, "Can't remove drop-in directory %s/%s: %m", where, md);
+
+                        if (errno != ENOENT && ret >= 0)
+                                ret = -errno;
+                } else
+                        portable_changes_add_with_prefix(changes, n_changes, PORTABLE_UNLINK, where, md, NULL);
+        }
+
+        /* Now, also drop any image symlink, for images outside of the sarch path */
+        SET_FOREACH(item, markers) {
+                _cleanup_free_ char *sl = NULL;
+                struct stat st;
+
+                r = image_symlink(item, flags, &sl);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to determine image symlink for '%s', ignoring: %m", item);
+                        continue;
+                }
+
+                if (lstat(sl, &st) < 0) {
+                        log_debug_errno(errno, "Failed to stat '%s', ignoring: %m", sl);
+                        continue;
+                }
+
+                if (!S_ISLNK(st.st_mode)) {
+                        log_debug("Image '%s' is not a symlink, ignoring.", sl);
+                        continue;
+                }
+
+                if (unlink(sl) < 0) {
+                        log_debug_errno(errno, "Can't remove image symlink '%s': %m", sl);
+
+                        if (errno != ENOENT && ret >= 0)
+                                ret = -errno;
+                } else
+                        portable_changes_add(changes, n_changes, PORTABLE_UNLINK, sl, NULL);
+        }
+
+        /* Try to remove the unit file directory, if we can */
+        if (rmdir(where) >= 0)
+                portable_changes_add(changes, n_changes, PORTABLE_UNLINK, where, NULL);
+
+        return ret;
+
+not_found:
+        extensions = strv_join(extension_image_paths, ", ");
+        if (!extensions)
+                return -ENOMEM;
+
+        r = sd_bus_error_setf(error,
+                              BUS_ERROR_NO_SUCH_UNIT,
+                              "No unit files associated with '%s%s%s' found attached to the system. Image not attached?",
+                              name_or_path,
+                              isempty(extensions) ? "" : "' or any of its extensions '",
+                              isempty(extensions) ? "" : extensions);
+        return log_debug_errno(r, "%s", error->message);
+}
+
+static int portable_get_state_internal(
+                sd_bus *bus,
+                const char *name_or_path,
+                char **extension_image_paths,
+                PortableFlags flags,
+                PortableState *ret,
+                sd_bus_error *error) {
+
+        _cleanup_(lookup_paths_free) LookupPaths paths = {};
+        bool found_enabled = false, found_running = false;
+        _cleanup_set_free_ Set *unit_files = NULL;
+        _cleanup_closedir_ DIR *d = NULL;
+        const char *where;
+        int r;
+
+        assert(name_or_path);
+        assert(ret);
+
+        r = lookup_paths_init(&paths, LOOKUP_SCOPE_SYSTEM, LOOKUP_PATHS_SPLIT_USR, NULL);
+        if (r < 0)
+                return r;
+
+        where = attached_path(&paths, flags);
+
+        d = opendir(where);
+        if (!d) {
+                if (errno == ENOENT) {
+                        /* If the 'attached' directory doesn't exist at all, then we know for sure this image isn't attached. */
+                        *ret = PORTABLE_DETACHED;
+                        return 0;
+                }
+
+                return log_debug_errno(errno, "Failed to open '%s' directory: %m", where);
+        }
+
+        FOREACH_DIRENT(de, d, return log_debug_errno(errno, "Failed to enumerate '%s' directory: %m", where)) {
+                UnitFileState state;
+
+                if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
+                        continue;
+
+                /* Filter out duplicates */
+                if (set_contains(unit_files, de->d_name))
+                        continue;
+
+                if (!IN_SET(de->d_type, DT_LNK, DT_REG))
+                        continue;
+
+                r = test_chroot_dropin(d, where, de->d_name, name_or_path, extension_image_paths, NULL);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        continue;
+
+                r = unit_file_lookup_state(LOOKUP_SCOPE_SYSTEM, &paths, de->d_name, &state);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to determine unit file state of '%s': %m", de->d_name);
+                if (!IN_SET(state, UNIT_FILE_STATIC, UNIT_FILE_DISABLED, UNIT_FILE_LINKED, UNIT_FILE_LINKED_RUNTIME))
+                        found_enabled = true;
+
+                r = unit_file_is_active(bus, de->d_name, error);
+                if (r < 0)
+                        return r;
+                if (r > 0)
+                        found_running = true;
+
+                r = set_put_strdup(&unit_files, de->d_name);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to add unit name '%s' to set: %m", de->d_name);
+        }
+
+        *ret = found_running ? (!set_isempty(unit_files) && (flags & PORTABLE_RUNTIME) ? PORTABLE_RUNNING_RUNTIME : PORTABLE_RUNNING) :
+                found_enabled ?            (flags & PORTABLE_RUNTIME ? PORTABLE_ENABLED_RUNTIME : PORTABLE_ENABLED) :
+                !set_isempty(unit_files) ? (flags & PORTABLE_RUNTIME ? PORTABLE_ATTACHED_RUNTIME : PORTABLE_ATTACHED) : PORTABLE_DETACHED;
+
+        return 0;
+}
+
+int portable_get_state(
+                sd_bus *bus,
+                const char *name_or_path,
+                char **extension_image_paths,
+                PortableFlags flags,
+                PortableState *ret,
+                sd_bus_error *error) {
+
+        PortableState state;
+        int r;
+
+        assert(name_or_path);
+        assert(ret);
+
+        /* We look for matching units twice: once in the regular directories, and once in the runtime directories — but
+         * the latter only if we didn't find anything in the former. */
+
+        r = portable_get_state_internal(bus, name_or_path, extension_image_paths, flags & ~PORTABLE_RUNTIME, &state, error);
+        if (r < 0)
+                return r;
+
+        if (state == PORTABLE_DETACHED) {
+                r = portable_get_state_internal(bus, name_or_path, extension_image_paths, flags | PORTABLE_RUNTIME, &state, error);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret = state;
+        return 0;
+}
+
+int portable_get_profiles(char ***ret) {
+        assert(ret);
+
+        return conf_files_list_nulstr(ret, NULL, NULL, CONF_FILES_DIRECTORY|CONF_FILES_BASENAME|CONF_FILES_FILTER_MASKED, PORTABLE_PROFILE_DIRS);
+}
+
+static const char* const portable_change_type_table[_PORTABLE_CHANGE_TYPE_MAX] = {
+        [PORTABLE_COPY] = "copy",
+        [PORTABLE_MKDIR] = "mkdir",
+        [PORTABLE_SYMLINK] = "symlink",
+        [PORTABLE_UNLINK] = "unlink",
+        [PORTABLE_WRITE] = "write",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(portable_change_type, int);
+
+static const char* const portable_state_table[_PORTABLE_STATE_MAX] = {
+        [PORTABLE_DETACHED] = "detached",
+        [PORTABLE_ATTACHED] = "attached",
+        [PORTABLE_ATTACHED_RUNTIME] = "attached-runtime",
+        [PORTABLE_ENABLED] = "enabled",
+        [PORTABLE_ENABLED_RUNTIME] = "enabled-runtime",
+        [PORTABLE_RUNNING] = "running",
+        [PORTABLE_RUNNING_RUNTIME] = "running-runtime",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(portable_state, PortableState);