| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <fcntl.h> |
| #include <getopt.h> |
| #include <linux/loop.h> |
| #include <sys/file.h> |
| #include <sys/mount.h> |
| #include <unistd.h> |
| |
| #include "build.h" |
| #include "capability-util.h" |
| #include "chase-symlinks.h" |
| #include "devnum-util.h" |
| #include "discover-image.h" |
| #include "dissect-image.h" |
| #include "env-util.h" |
| #include "escape.h" |
| #include "extension-release.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "format-table.h" |
| #include "fs-util.h" |
| #include "hashmap.h" |
| #include "initrd-util.h" |
| #include "log.h" |
| #include "main-func.h" |
| #include "missing_magic.h" |
| #include "mkdir.h" |
| #include "mount-util.h" |
| #include "mountpoint-util.h" |
| #include "os-util.h" |
| #include "pager.h" |
| #include "parse-argument.h" |
| #include "parse-util.h" |
| #include "pretty-print.h" |
| #include "process-util.h" |
| #include "sort-util.h" |
| #include "terminal-util.h" |
| #include "user-util.h" |
| #include "verbs.h" |
| |
| static char **arg_hierarchies = NULL; /* "/usr" + "/opt" by default */ |
| static char *arg_root = NULL; |
| static JsonFormatFlags arg_json_format_flags = JSON_FORMAT_OFF; |
| static PagerFlags arg_pager_flags = 0; |
| static bool arg_legend = true; |
| static bool arg_force = false; |
| |
| STATIC_DESTRUCTOR_REGISTER(arg_hierarchies, strv_freep); |
| STATIC_DESTRUCTOR_REGISTER(arg_root, freep); |
| |
| static int is_our_mount_point(const char *p) { |
| _cleanup_free_ char *buf = NULL, *f = NULL; |
| struct stat st; |
| dev_t dev; |
| int r; |
| |
| r = path_is_mount_point(p, NULL, 0); |
| if (r == -ENOENT) { |
| log_debug_errno(r, "Hierarchy '%s' doesn't exist.", p); |
| return false; |
| } |
| if (r < 0) |
| return log_error_errno(r, "Failed to determine whether '%s' is a mount point: %m", p); |
| if (r == 0) { |
| log_debug("Hierarchy '%s' is not a mount point, skipping.", p); |
| return false; |
| } |
| |
| /* So we know now that it's a mount point. Now let's check if it's one of ours, so that we don't |
| * accidentally unmount the user's own /usr/ but just the mounts we established ourselves. We do this |
| * check by looking into the metadata directory we place in merged mounts: if the file |
| * .systemd-sysext/dev contains the major/minor device pair of the mount we have a good reason to |
| * believe this is one of our mounts. This thorough check has the benefit that we aren't easily |
| * confused if people tar up one of our merged trees and untar them elsewhere where we might mistake |
| * them for a live sysext tree. */ |
| |
| f = path_join(p, ".systemd-sysext/dev"); |
| if (!f) |
| return log_oom(); |
| |
| r = read_one_line_file(f, &buf); |
| if (r == -ENOENT) { |
| log_debug("Hierarchy '%s' does not carry a .systemd-sysext/dev file, not a sysext merged tree.", p); |
| return false; |
| } |
| if (r < 0) |
| return log_error_errno(r, "Failed to determine whether hierarchy '%s' contains '.systemd-sysext/dev': %m", p); |
| |
| r = parse_devnum(buf, &dev); |
| if (r < 0) |
| return log_error_errno(r, "Failed to parse device major/minor stored in '.systemd-sysext/dev' file on '%s': %m", p); |
| |
| if (lstat(p, &st) < 0) |
| return log_error_errno(r, "Failed to stat %s: %m", p); |
| |
| if (st.st_dev != dev) { |
| log_debug("Hierarchy '%s' reports a different device major/minor than what we are seeing, assuming offline copy.", p); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static int unmerge_hierarchy(const char *p) { |
| int r; |
| |
| for (;;) { |
| /* We only unmount /usr/ if it is a mount point and really one of ours, in order not to break |
| * systems where /usr/ is a mount point of its own already. */ |
| |
| r = is_our_mount_point(p); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| break; |
| |
| r = umount_verbose(LOG_ERR, p, MNT_DETACH|UMOUNT_NOFOLLOW); |
| if (r < 0) |
| return log_error_errno(r, "Failed to unmount file system '%s': %m", p); |
| |
| log_info("Unmerged '%s'.", p); |
| } |
| |
| return 0; |
| } |
| |
| static int unmerge(void) { |
| int r, ret = 0; |
| |
| STRV_FOREACH(p, arg_hierarchies) { |
| _cleanup_free_ char *resolved = NULL; |
| |
| r = chase_symlinks(*p, arg_root, CHASE_PREFIX_ROOT, &resolved, NULL); |
| if (r == -ENOENT) { |
| log_debug_errno(r, "Hierarchy '%s%s' does not exist, ignoring.", strempty(arg_root), *p); |
| continue; |
| } |
| if (r < 0) { |
| log_error_errno(r, "Failed to resolve path to hierarchy '%s%s': %m", strempty(arg_root), *p); |
| if (ret == 0) |
| ret = r; |
| |
| continue; |
| } |
| |
| r = unmerge_hierarchy(resolved); |
| if (r < 0 && ret == 0) |
| ret = r; |
| } |
| |
| return ret; |
| } |
| |
| static int verb_unmerge(int argc, char **argv, void *userdata) { |
| int r; |
| |
| r = have_effective_cap(CAP_SYS_ADMIN); |
| if (r < 0) |
| return log_error_errno(r, "Failed to check if we have enough privileges: %m"); |
| if (r == 0) |
| return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Need to be privileged."); |
| |
| return unmerge(); |
| } |
| |
| static int verb_status(int argc, char **argv, void *userdata) { |
| _cleanup_(table_unrefp) Table *t = NULL; |
| int r, ret = 0; |
| |
| t = table_new("hierarchy", "extensions", "since"); |
| if (!t) |
| return log_oom(); |
| |
| table_set_ersatz_string(t, TABLE_ERSATZ_DASH); |
| |
| STRV_FOREACH(p, arg_hierarchies) { |
| _cleanup_free_ char *resolved = NULL, *f = NULL, *buf = NULL; |
| _cleanup_strv_free_ char **l = NULL; |
| struct stat st; |
| |
| r = chase_symlinks(*p, arg_root, CHASE_PREFIX_ROOT, &resolved, NULL); |
| if (r == -ENOENT) { |
| log_debug_errno(r, "Hierarchy '%s%s' does not exist, ignoring.", strempty(arg_root), *p); |
| continue; |
| } |
| if (r < 0) { |
| log_error_errno(r, "Failed to resolve path to hierarchy '%s%s': %m", strempty(arg_root), *p); |
| goto inner_fail; |
| } |
| |
| r = is_our_mount_point(resolved); |
| if (r < 0) |
| goto inner_fail; |
| if (r == 0) { |
| r = table_add_many( |
| t, |
| TABLE_PATH, *p, |
| TABLE_STRING, "none", |
| TABLE_SET_COLOR, ansi_grey(), |
| TABLE_EMPTY); |
| if (r < 0) |
| return table_log_add_error(r); |
| |
| continue; |
| } |
| |
| f = path_join(*p, ".systemd-sysext/extensions"); |
| if (!f) |
| return log_oom(); |
| |
| r = read_full_file(f, &buf, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to open '%s': %m", f); |
| |
| l = strv_split_newlines(buf); |
| if (!l) |
| return log_oom(); |
| |
| if (stat(*p, &st) < 0) |
| return log_error_errno(r, "Failed to stat() '%s': %m", *p); |
| |
| r = table_add_many( |
| t, |
| TABLE_PATH, *p, |
| TABLE_STRV, l, |
| TABLE_TIMESTAMP, timespec_load(&st.st_mtim)); |
| if (r < 0) |
| return table_log_add_error(r); |
| |
| continue; |
| |
| inner_fail: |
| if (ret == 0) |
| ret = r; |
| } |
| |
| (void) table_set_sort(t, (size_t) 0); |
| |
| r = table_print_with_pager(t, arg_json_format_flags, arg_pager_flags, arg_legend); |
| if (r < 0) |
| return r; |
| |
| return ret; |
| } |
| |
| static int mount_overlayfs( |
| const char *where, |
| char **layers) { |
| |
| _cleanup_free_ char *options = NULL; |
| bool separator = false; |
| int r; |
| |
| assert(where); |
| |
| options = strdup("lowerdir="); |
| if (!options) |
| return log_oom(); |
| |
| STRV_FOREACH(l, layers) { |
| _cleanup_free_ char *escaped = NULL; |
| |
| escaped = shell_escape(*l, ",:"); |
| if (!escaped) |
| return log_oom(); |
| |
| if (!strextend(&options, separator ? ":" : "", escaped)) |
| return log_oom(); |
| |
| separator = true; |
| } |
| |
| /* Now mount the actual overlayfs */ |
| r = mount_nofollow_verbose(LOG_ERR, "sysext", where, "overlay", MS_RDONLY, options); |
| if (r < 0) |
| return r; |
| |
| return 0; |
| } |
| |
| static int merge_hierarchy( |
| const char *hierarchy, |
| char **extensions, |
| char **paths, |
| const char *meta_path, |
| const char *overlay_path) { |
| |
| _cleanup_free_ char *resolved_hierarchy = NULL, *f = NULL, *buf = NULL; |
| _cleanup_strv_free_ char **layers = NULL; |
| struct stat st; |
| int r; |
| |
| assert(hierarchy); |
| assert(meta_path); |
| assert(overlay_path); |
| |
| /* Resolve the path of the host's version of the hierarchy, i.e. what we want to use as lowest layer |
| * in the overlayfs stack. */ |
| r = chase_symlinks(hierarchy, arg_root, CHASE_PREFIX_ROOT, &resolved_hierarchy, NULL); |
| if (r == -ENOENT) |
| log_debug_errno(r, "Hierarchy '%s' on host doesn't exist, not merging.", hierarchy); |
| else if (r < 0) |
| return log_error_errno(r, "Failed to resolve host hierarchy '%s': %m", hierarchy); |
| else { |
| r = dir_is_empty(resolved_hierarchy, /* ignore_hidden_or_backup= */ false); |
| if (r < 0) |
| return log_error_errno(r, "Failed to check if host hierarchy '%s' is empty: %m", resolved_hierarchy); |
| if (r > 0) { |
| log_debug("Host hierarchy '%s' is empty, not merging.", resolved_hierarchy); |
| resolved_hierarchy = mfree(resolved_hierarchy); |
| } |
| } |
| |
| /* Let's generate a metadata file that lists all extensions we took into account for this |
| * hierarchy. We include this in the final fs, to make things nicely discoverable and |
| * recognizable. */ |
| f = path_join(meta_path, ".systemd-sysext/extensions"); |
| if (!f) |
| return log_oom(); |
| |
| buf = strv_join(extensions, "\n"); |
| if (!buf) |
| return log_oom(); |
| |
| r = write_string_file(f, buf, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_MKDIR_0755); |
| if (r < 0) |
| return log_error_errno(r, "Failed to write extension meta file '%s': %m", f); |
| |
| /* Put the meta path (i.e. our synthesized stuff) at the top of the layer stack */ |
| layers = strv_new(meta_path); |
| if (!layers) |
| return log_oom(); |
| |
| /* Put the extensions in the middle */ |
| STRV_FOREACH(p, paths) { |
| _cleanup_free_ char *resolved = NULL; |
| |
| r = chase_symlinks(hierarchy, *p, CHASE_PREFIX_ROOT, &resolved, NULL); |
| if (r == -ENOENT) { |
| log_debug_errno(r, "Hierarchy '%s' in extension '%s' doesn't exist, not merging.", hierarchy, *p); |
| continue; |
| } |
| if (r < 0) |
| return log_error_errno(r, "Failed to resolve hierarchy '%s' in extension '%s': %m", hierarchy, *p); |
| |
| r = dir_is_empty(resolved, /* ignore_hidden_or_backup= */ false); |
| if (r < 0) |
| return log_error_errno(r, "Failed to check if hierarchy '%s' in extension '%s' is empty: %m", resolved, *p); |
| if (r > 0) { |
| log_debug("Hierarchy '%s' in extension '%s' is empty, not merging.", hierarchy, *p); |
| continue; |
| } |
| |
| r = strv_consume(&layers, TAKE_PTR(resolved)); |
| if (r < 0) |
| return log_oom(); |
| } |
| |
| if (!layers[1]) /* No extension with files in this hierarchy? Then don't do anything. */ |
| return 0; |
| |
| if (resolved_hierarchy) { |
| /* Add the host hierarchy as last (lowest) layer in the stack */ |
| r = strv_consume(&layers, TAKE_PTR(resolved_hierarchy)); |
| if (r < 0) |
| return log_oom(); |
| } |
| |
| r = mkdir_p(overlay_path, 0700); |
| if (r < 0) |
| return log_error_errno(r, "Failed to make directory '%s': %m", overlay_path); |
| |
| r = mount_overlayfs(overlay_path, layers); |
| if (r < 0) |
| return r; |
| |
| /* The overlayfs superblock is read-only. Let's also mark the bind mount read-only. Extra turbo safety 😎 */ |
| r = bind_remount_recursive(overlay_path, MS_RDONLY, MS_RDONLY, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to make bind mount '%s' read-only: %m", overlay_path); |
| |
| /* Now we have mounted the new file system. Let's now figure out its .st_dev field, and make that |
| * available in the metadata directory. This is useful to detect whether the metadata dir actually |
| * belongs to the fs it is found on: if .st_dev of the top-level mount matches it, it's pretty likely |
| * we are looking at a live sysext tree, and not an unpacked tar or so of one. */ |
| if (stat(overlay_path, &st) < 0) |
| return log_error_errno(r, "Failed to stat mount '%s': %m", overlay_path); |
| |
| free(f); |
| f = path_join(meta_path, ".systemd-sysext/dev"); |
| if (!f) |
| return log_oom(); |
| |
| r = write_string_filef(f, WRITE_STRING_FILE_CREATE, "%u:%u", major(st.st_dev), minor(st.st_dev)); |
| if (r < 0) |
| return log_error_errno(r, "Failed to write '%s': %m", f); |
| |
| /* Make sure the top-level dir has an mtime marking the point we established the merge */ |
| if (utimensat(AT_FDCWD, meta_path, NULL, AT_SYMLINK_NOFOLLOW) < 0) |
| return log_error_errno(r, "Failed fix mtime of '%s': %m", meta_path); |
| |
| return 1; |
| } |
| |
| static int strverscmp_improvedp(char *const* a, char *const* b) { |
| /* usable in qsort() for sorting a string array with strverscmp_improved() */ |
| return strverscmp_improved(*a, *b); |
| } |
| |
| static int validate_version( |
| const char *root, |
| const Image *img, |
| const char *host_os_release_id, |
| const char *host_os_release_version_id, |
| const char *host_os_release_sysext_level) { |
| |
| int r; |
| |
| assert(root); |
| assert(img); |
| |
| if (arg_force) { |
| log_debug("Force mode enabled, skipping version validation."); |
| return 1; |
| } |
| |
| /* Insist that extension images do not overwrite the underlying OS release file (it's fine if |
| * they place one in /etc/os-release, i.e. where things don't matter, as they aren't |
| * merged.) */ |
| r = chase_symlinks("/usr/lib/os-release", root, CHASE_PREFIX_ROOT, NULL, NULL); |
| if (r < 0) { |
| if (r != -ENOENT) |
| return log_error_errno(r, "Failed to determine whether /usr/lib/os-release exists in the extension image: %m"); |
| } else |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Extension image contains /usr/lib/os-release file, which is not allowed (it may carry /etc/os-release), refusing."); |
| |
| r = extension_release_validate( |
| img->name, |
| host_os_release_id, |
| host_os_release_version_id, |
| host_os_release_sysext_level, |
| in_initrd() ? "initrd" : "system", |
| img->extension_release); |
| if (r < 0) |
| return log_error_errno(r, "Failed to validate extension release information: %m"); |
| |
| return r; |
| } |
| |
| static int merge_subprocess(Hashmap *images, const char *workspace) { |
| _cleanup_free_ char *host_os_release_id = NULL, *host_os_release_version_id = NULL, *host_os_release_sysext_level = NULL, |
| *buf = NULL; |
| _cleanup_strv_free_ char **extensions = NULL, **paths = NULL; |
| size_t n_extensions = 0; |
| unsigned n_ignored = 0; |
| Image *img; |
| int r; |
| |
| /* Mark the whole of /run as MS_SLAVE, so that we can mount stuff below it that doesn't show up on |
| * the host otherwise. */ |
| r = mount_nofollow_verbose(LOG_ERR, NULL, "/run", NULL, MS_SLAVE|MS_REC, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to remount /run/ MS_SLAVE: %m"); |
| |
| /* Let's create the workspace if it's missing */ |
| r = mkdir_p(workspace, 0700); |
| if (r < 0) |
| return log_error_errno(r, "Failed to create /run/systemd/sysext: %m"); |
| |
| /* Let's mount a tmpfs to our workspace. This way we don't need to clean up the inodes we mount over, |
| * but let the kernel do that entirely automatically, once our namespace dies. Note that this file |
| * system won't be visible to anyone but us, since we opened our own namespace and then made the |
| * /run/ hierarchy (which our workspace is contained in) MS_SLAVE, see above. */ |
| r = mount_nofollow_verbose(LOG_ERR, "sysext", workspace, "tmpfs", 0, "mode=0700"); |
| if (r < 0) |
| return r; |
| |
| /* Acquire host OS release info, so that we can compare it with the extension's data */ |
| r = parse_os_release( |
| arg_root, |
| "ID", &host_os_release_id, |
| "VERSION_ID", &host_os_release_version_id, |
| "SYSEXT_LEVEL", &host_os_release_sysext_level); |
| if (r < 0) |
| return log_error_errno(r, "Failed to acquire 'os-release' data of OS tree '%s': %m", empty_to_root(arg_root)); |
| if (isempty(host_os_release_id)) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "'ID' field not found or empty in 'os-release' data of OS tree '%s': %m", |
| empty_to_root(arg_root)); |
| |
| /* Let's now mount all images */ |
| HASHMAP_FOREACH(img, images) { |
| _cleanup_free_ char *p = NULL; |
| |
| p = path_join(workspace, "extensions", img->name); |
| if (!p) |
| return log_oom(); |
| |
| r = mkdir_p(p, 0700); |
| if (r < 0) |
| return log_error_errno(r, "Failed to create %s: %m", p); |
| |
| switch (img->type) { |
| case IMAGE_DIRECTORY: |
| case IMAGE_SUBVOLUME: |
| r = mount_nofollow_verbose(LOG_ERR, img->path, p, NULL, MS_BIND, NULL); |
| if (r < 0) |
| return r; |
| |
| /* Make this a read-only bind mount */ |
| r = bind_remount_recursive(p, MS_RDONLY, MS_RDONLY, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to make bind mount '%s' read-only: %m", p); |
| |
| break; |
| |
| case IMAGE_RAW: |
| case IMAGE_BLOCK: { |
| _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL; |
| _cleanup_(loop_device_unrefp) LoopDevice *d = NULL; |
| _cleanup_(verity_settings_done) VeritySettings verity_settings = VERITY_SETTINGS_DEFAULT; |
| DissectImageFlags flags = |
| DISSECT_IMAGE_READ_ONLY | |
| DISSECT_IMAGE_GENERIC_ROOT | |
| DISSECT_IMAGE_REQUIRE_ROOT | |
| DISSECT_IMAGE_MOUNT_ROOT_ONLY | |
| DISSECT_IMAGE_USR_NO_ROOT | |
| DISSECT_IMAGE_ADD_PARTITION_DEVICES | |
| DISSECT_IMAGE_PIN_PARTITION_DEVICES; |
| |
| r = verity_settings_load(&verity_settings, img->path, NULL, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to read verity artifacts for %s: %m", img->path); |
| |
| if (verity_settings.data_path) |
| flags |= DISSECT_IMAGE_NO_PARTITION_TABLE; |
| |
| r = loop_device_make_by_path( |
| img->path, |
| O_RDONLY, |
| /* sector_size= */ UINT32_MAX, |
| FLAGS_SET(flags, DISSECT_IMAGE_NO_PARTITION_TABLE) ? 0 : LO_FLAGS_PARTSCAN, |
| LOCK_SH, |
| &d); |
| if (r < 0) |
| return log_error_errno(r, "Failed to set up loopback device for %s: %m", img->path); |
| |
| r = dissect_loop_device_and_warn( |
| d, |
| &verity_settings, |
| NULL, |
| flags, |
| &m); |
| if (r < 0) |
| return r; |
| |
| r = dissected_image_load_verity_sig_partition( |
| m, |
| d->fd, |
| &verity_settings); |
| if (r < 0) |
| return r; |
| |
| r = dissected_image_decrypt_interactively( |
| m, NULL, |
| &verity_settings, |
| flags); |
| if (r < 0) |
| return r; |
| |
| r = dissected_image_mount_and_warn( |
| m, |
| p, |
| UID_INVALID, |
| UID_INVALID, |
| flags); |
| if (r < 0) |
| return r; |
| |
| r = dissected_image_relinquish(m); |
| if (r < 0) |
| return log_error_errno(r, "Failed to relinquish DM and loopback block devices: %m"); |
| break; |
| } |
| default: |
| assert_not_reached(); |
| } |
| |
| r = validate_version( |
| p, |
| img, |
| host_os_release_id, |
| host_os_release_version_id, |
| host_os_release_sysext_level); |
| if (r < 0) |
| return r; |
| if (r == 0) { |
| n_ignored++; |
| continue; |
| } |
| |
| /* Nice! This one is an extension we want. */ |
| r = strv_extend(&extensions, img->name); |
| if (r < 0) |
| return log_oom(); |
| |
| n_extensions ++; |
| } |
| |
| /* Nothing left? Then shortcut things */ |
| if (n_extensions == 0) { |
| if (n_ignored > 0) |
| log_info("No suitable extensions found (%u ignored due to incompatible version).", n_ignored); |
| else |
| log_info("No extensions found."); |
| return 0; |
| } |
| |
| /* Order by version sort with strverscmp_improved() */ |
| typesafe_qsort(extensions, n_extensions, strverscmp_improvedp); |
| |
| buf = strv_join(extensions, "', '"); |
| if (!buf) |
| return log_oom(); |
| |
| log_info("Using extensions '%s'.", buf); |
| |
| /* Build table of extension paths (in reverse order) */ |
| paths = new0(char*, n_extensions + 1); |
| if (!paths) |
| return log_oom(); |
| |
| for (size_t k = 0; k < n_extensions; k++) { |
| _cleanup_free_ char *p = NULL; |
| |
| assert_se(img = hashmap_get(images, extensions[n_extensions - 1 - k])); |
| |
| p = path_join(workspace, "extensions", img->name); |
| if (!p) |
| return log_oom(); |
| |
| paths[k] = TAKE_PTR(p); |
| } |
| |
| /* Let's now unmerge the status quo ante, since to build the new overlayfs we need a reference to the |
| * underlying fs. */ |
| STRV_FOREACH(h, arg_hierarchies) { |
| _cleanup_free_ char *resolved = NULL; |
| |
| r = chase_symlinks(*h, arg_root, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &resolved, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to resolve hierarchy '%s%s': %m", strempty(arg_root), *h); |
| |
| r = unmerge_hierarchy(resolved); |
| if (r < 0) |
| return r; |
| } |
| |
| /* Create overlayfs mounts for all hierarchies */ |
| STRV_FOREACH(h, arg_hierarchies) { |
| _cleanup_free_ char *meta_path = NULL, *overlay_path = NULL; |
| |
| meta_path = path_join(workspace, "meta", *h); /* The place where to store metadata about this instance */ |
| if (!meta_path) |
| return log_oom(); |
| |
| overlay_path = path_join(workspace, "overlay", *h); /* The resulting overlayfs instance */ |
| if (!overlay_path) |
| return log_oom(); |
| |
| r = merge_hierarchy(*h, extensions, paths, meta_path, overlay_path); |
| if (r < 0) |
| return r; |
| } |
| |
| /* And move them all into place. This is where things appear in the host namespace */ |
| STRV_FOREACH(h, arg_hierarchies) { |
| _cleanup_free_ char *p = NULL, *resolved = NULL; |
| |
| p = path_join(workspace, "overlay", *h); |
| if (!p) |
| return log_oom(); |
| |
| if (laccess(p, F_OK) < 0) { |
| if (errno != ENOENT) |
| return log_error_errno(errno, "Failed to check if '%s' exists: %m", p); |
| |
| /* Hierarchy apparently was empty in all extensions, and wasn't mounted, ignoring. */ |
| continue; |
| } |
| |
| r = chase_symlinks(*h, arg_root, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &resolved, NULL); |
| if (r < 0) |
| return log_error_errno(r, "Failed to resolve hierarchy '%s%s': %m", strempty(arg_root), *h); |
| |
| r = mkdir_p(resolved, 0755); |
| if (r < 0) |
| return log_error_errno(r, "Failed to create hierarchy mount point '%s': %m", resolved); |
| |
| r = mount_nofollow_verbose(LOG_ERR, p, resolved, NULL, MS_BIND, NULL); |
| if (r < 0) |
| return r; |
| |
| log_info("Merged extensions into '%s'.", resolved); |
| } |
| |
| return 1; |
| } |
| |
| static int merge(Hashmap *images) { |
| pid_t pid; |
| int r; |
| |
| r = safe_fork("(sd-sysext)", FORK_DEATHSIG|FORK_LOG|FORK_NEW_MOUNTNS, &pid); |
| if (r < 0) |
| return log_error_errno(r, "Failed to fork off child: %m"); |
| if (r == 0) { |
| /* Child with its own mount namespace */ |
| |
| r = merge_subprocess(images, "/run/systemd/sysext"); |
| if (r < 0) |
| _exit(EXIT_FAILURE); |
| |
| /* Our namespace ceases to exist here, also implicitly detaching all temporary mounts we |
| * created below /run. Nice! */ |
| |
| _exit(r > 0 ? EXIT_SUCCESS : 123); /* 123 means: didn't find any extensions */ |
| } |
| |
| r = wait_for_terminate_and_check("(sd-sysext)", pid, WAIT_LOG_ABNORMAL); |
| if (r < 0) |
| return r; |
| |
| return r != 123; /* exit code 123 means: didn't do anything */ |
| } |
| |
| static int image_discover_and_read_metadata(Hashmap **ret_images) { |
| _cleanup_(hashmap_freep) Hashmap *images = NULL; |
| Image *img; |
| int r; |
| |
| assert(ret_images); |
| |
| images = hashmap_new(&image_hash_ops); |
| if (!images) |
| return log_oom(); |
| |
| r = image_discover(IMAGE_EXTENSION, arg_root, images); |
| if (r < 0) |
| return log_error_errno(r, "Failed to discover extension images: %m"); |
| |
| HASHMAP_FOREACH(img, images) { |
| r = image_read_metadata(img); |
| if (r < 0) |
| return log_error_errno(r, "Failed to read metadata for image %s: %m", img->name); |
| } |
| |
| *ret_images = TAKE_PTR(images); |
| |
| return 0; |
| } |
| |
| static int verb_merge(int argc, char **argv, void *userdata) { |
| _cleanup_(hashmap_freep) Hashmap *images = NULL; |
| int r; |
| |
| r = have_effective_cap(CAP_SYS_ADMIN); |
| if (r < 0) |
| return log_error_errno(r, "Failed to check if we have enough privileges: %m"); |
| if (r == 0) |
| return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Need to be privileged."); |
| |
| r = image_discover_and_read_metadata(&images); |
| if (r < 0) |
| return r; |
| |
| /* In merge mode fail if things are already merged. (In --refresh mode below we'll unmerge if we find |
| * things are already merged...) */ |
| STRV_FOREACH(p, arg_hierarchies) { |
| _cleanup_free_ char *resolved = NULL; |
| |
| r = chase_symlinks(*p, arg_root, CHASE_PREFIX_ROOT, &resolved, NULL); |
| if (r == -ENOENT) { |
| log_debug_errno(r, "Hierarchy '%s%s' does not exist, ignoring.", strempty(arg_root), *p); |
| continue; |
| } |
| if (r < 0) |
| return log_error_errno(r, "Failed to resolve path to hierarchy '%s%s': %m", strempty(arg_root), *p); |
| |
| r = is_our_mount_point(resolved); |
| if (r < 0) |
| return r; |
| if (r > 0) |
| return log_error_errno(SYNTHETIC_ERRNO(EBUSY), |
| "Hierarchy '%s' is already merged.", *p); |
| } |
| |
| return merge(images); |
| } |
| |
| static int verb_refresh(int argc, char **argv, void *userdata) { |
| _cleanup_(hashmap_freep) Hashmap *images = NULL; |
| int r; |
| |
| r = have_effective_cap(CAP_SYS_ADMIN); |
| if (r < 0) |
| return log_error_errno(r, "Failed to check if we have enough privileges: %m"); |
| if (r == 0) |
| return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Need to be privileged."); |
| |
| r = image_discover_and_read_metadata(&images); |
| if (r < 0) |
| return r; |
| |
| r = merge(images); /* Returns > 0 if it did something, i.e. a new overlayfs is mounted now. When it |
| * does so it implicitly unmounts any overlayfs placed there before. Returns == 0 |
| * if it did nothing, i.e. no extension images found. In this case the old |
| * overlayfs remains in place if there was one. */ |
| if (r < 0) |
| return r; |
| if (r == 0) /* No images found? Then unmerge. The goal of --refresh is after all that after having |
| * called there's a guarantee that the merge status matches the installed extensions. */ |
| r = unmerge(); |
| |
| /* Net result here is that: |
| * |
| * 1. If an overlayfs was mounted before and no extensions exist anymore, we'll have unmerged things. |
| * |
| * 2. If an overlayfs was mounted before, and there are still extensions installed' we'll have |
| * unmerged and then merged things again. |
| * |
| * 3. If an overlayfs so far wasn't mounted, and there are extensions installed, we'll have it |
| * mounted now. |
| * |
| * 4. If there was no overlayfs mount so far, and no extensions installed, we implement a NOP. |
| */ |
| |
| return 0; |
| } |
| |
| static int verb_list(int argc, char **argv, void *userdata) { |
| _cleanup_(hashmap_freep) Hashmap *images = NULL; |
| _cleanup_(table_unrefp) Table *t = NULL; |
| Image *img; |
| int r; |
| |
| images = hashmap_new(&image_hash_ops); |
| if (!images) |
| return log_oom(); |
| |
| r = image_discover(IMAGE_EXTENSION, arg_root, images); |
| if (r < 0) |
| return log_error_errno(r, "Failed to discover extension images: %m"); |
| |
| if ((arg_json_format_flags & JSON_FORMAT_OFF) && hashmap_isempty(images)) { |
| log_info("No OS extensions found."); |
| return 0; |
| } |
| |
| t = table_new("name", "type", "path", "time"); |
| if (!t) |
| return log_oom(); |
| |
| HASHMAP_FOREACH(img, images) { |
| r = table_add_many( |
| t, |
| TABLE_STRING, img->name, |
| TABLE_STRING, image_type_to_string(img->type), |
| TABLE_PATH, img->path, |
| TABLE_TIMESTAMP, img->mtime != 0 ? img->mtime : img->crtime); |
| if (r < 0) |
| return table_log_add_error(r); |
| } |
| |
| (void) table_set_sort(t, (size_t) 0); |
| |
| return table_print_with_pager(t, arg_json_format_flags, arg_pager_flags, arg_legend); |
| } |
| |
| static int verb_help(int argc, char **argv, void *userdata) { |
| _cleanup_free_ char *link = NULL; |
| int r; |
| |
| r = terminal_urlify_man("systemd-sysext", "8", &link); |
| if (r < 0) |
| return log_oom(); |
| |
| printf("%1$s [OPTIONS...] COMMAND\n" |
| "\n%5$sMerge extension images into /usr/ and /opt/ hierarchies.%6$s\n" |
| "\n%3$sCommands:%4$s\n" |
| " status Show current merge status (default)\n" |
| " merge Merge extensions into /usr/ and /opt/\n" |
| " unmerge Unmerge extensions from /usr/ and /opt/\n" |
| " refresh Unmerge/merge extensions again\n" |
| " list List installed extensions\n" |
| " -h --help Show this help\n" |
| " --version Show package version\n" |
| "\n%3$sOptions:%4$s\n" |
| " --no-pager Do not pipe output into a pager\n" |
| " --no-legend Do not show the headers and footers\n" |
| " --root=PATH Operate relative to root path\n" |
| " --json=pretty|short|off\n" |
| " Generate JSON output\n" |
| " --force Ignore version incompatibilities\n" |
| "\nSee the %2$s for details.\n", |
| program_invocation_short_name, |
| link, |
| ansi_underline(), |
| ansi_normal(), |
| ansi_highlight(), |
| ansi_normal()); |
| |
| return 0; |
| } |
| |
| static int parse_argv(int argc, char *argv[]) { |
| |
| enum { |
| ARG_VERSION = 0x100, |
| ARG_NO_PAGER, |
| ARG_NO_LEGEND, |
| ARG_ROOT, |
| ARG_JSON, |
| ARG_FORCE, |
| }; |
| |
| static const struct option options[] = { |
| { "help", no_argument, NULL, 'h' }, |
| { "version", no_argument, NULL, ARG_VERSION }, |
| { "no-pager", no_argument, NULL, ARG_NO_PAGER }, |
| { "no-legend", no_argument, NULL, ARG_NO_LEGEND }, |
| { "root", required_argument, NULL, ARG_ROOT }, |
| { "json", required_argument, NULL, ARG_JSON }, |
| { "force", no_argument, NULL, ARG_FORCE }, |
| {} |
| }; |
| |
| int c, r; |
| |
| assert(argc >= 0); |
| assert(argv); |
| |
| while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) |
| |
| switch (c) { |
| |
| case 'h': |
| return verb_help(argc, argv, NULL); |
| |
| case ARG_VERSION: |
| return version(); |
| |
| case ARG_NO_PAGER: |
| arg_pager_flags |= PAGER_DISABLE; |
| break; |
| |
| case ARG_NO_LEGEND: |
| arg_legend = false; |
| break; |
| |
| case ARG_ROOT: |
| r = parse_path_argument(optarg, false, &arg_root); |
| if (r < 0) |
| return r; |
| break; |
| |
| case ARG_JSON: |
| r = parse_json_argument(optarg, &arg_json_format_flags); |
| if (r <= 0) |
| return r; |
| |
| break; |
| |
| case ARG_FORCE: |
| arg_force = true; |
| break; |
| |
| case '?': |
| return -EINVAL; |
| |
| default: |
| assert_not_reached(); |
| } |
| |
| return 1; |
| } |
| |
| static int sysext_main(int argc, char *argv[]) { |
| |
| static const Verb verbs[] = { |
| { "status", VERB_ANY, 1, VERB_DEFAULT, verb_status }, |
| { "merge", VERB_ANY, 1, 0, verb_merge }, |
| { "unmerge", VERB_ANY, 1, 0, verb_unmerge }, |
| { "refresh", VERB_ANY, 1, 0, verb_refresh }, |
| { "list", VERB_ANY, 1, 0, verb_list }, |
| { "help", VERB_ANY, 1, 0, verb_help }, |
| {} |
| }; |
| |
| return dispatch_verb(argc, argv, verbs, NULL); |
| } |
| |
| static int run(int argc, char *argv[]) { |
| int r; |
| |
| log_setup(); |
| |
| r = parse_argv(argc, argv); |
| if (r <= 0) |
| return r; |
| |
| /* For debugging purposes it might make sense to do this for other hierarchies than /usr/ and |
| * /opt/, but let's make that a hacker/debugging feature, i.e. env var instead of cmdline |
| * switch. */ |
| r = parse_env_extension_hierarchies(&arg_hierarchies); |
| if (r < 0) |
| return log_error_errno(r, "Failed to parse $SYSTEMD_SYSEXT_HIERARCHIES environment variable: %m"); |
| |
| return sysext_main(argc, argv); |
| } |
| |
| DEFINE_MAIN_FUNCTION(run); |
