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-rw-r--r--src/shared/discover-image.c1313
1 files changed, 1313 insertions, 0 deletions
diff --git a/src/shared/discover-image.c b/src/shared/discover-image.c
new file mode 100644
index 0000000..0350dd1
--- /dev/null
+++ b/src/shared/discover-image.c
@@ -0,0 +1,1313 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fs.h>
+#include <linux/loop.h>
+#include <linux/magic.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "btrfs-util.h"
+#include "chase-symlinks.h"
+#include "chattr-util.h"
+#include "copy.h"
+#include "dirent-util.h"
+#include "discover-image.h"
+#include "dissect-image.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "hashmap.h"
+#include "hostname-setup.h"
+#include "id128-util.h"
+#include "lockfile-util.h"
+#include "log.h"
+#include "loop-util.h"
+#include "macro.h"
+#include "mkdir.h"
+#include "nulstr-util.h"
+#include "os-util.h"
+#include "path-util.h"
+#include "rm-rf.h"
+#include "stat-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "utf8.h"
+#include "xattr-util.h"
+
+static const char* const image_search_path[_IMAGE_CLASS_MAX] = {
+ [IMAGE_MACHINE] = "/etc/machines\0" /* only place symlinks here */
+ "/run/machines\0" /* and here too */
+ "/var/lib/machines\0" /* the main place for images */
+ "/var/lib/container\0" /* legacy */
+ "/usr/local/lib/machines\0"
+ "/usr/lib/machines\0",
+
+ [IMAGE_PORTABLE] = "/etc/portables\0" /* only place symlinks here */
+ "/run/portables\0" /* and here too */
+ "/var/lib/portables\0" /* the main place for images */
+ "/usr/local/lib/portables\0"
+ "/usr/lib/portables\0",
+
+ [IMAGE_EXTENSION] = "/etc/extensions\0" /* only place symlinks here */
+ "/run/extensions\0" /* and here too */
+ "/var/lib/extensions\0" /* the main place for images */
+ "/usr/local/lib/extensions\0"
+ "/usr/lib/extensions\0",
+};
+
+static Image *image_free(Image *i) {
+ assert(i);
+
+ free(i->name);
+ free(i->path);
+
+ free(i->hostname);
+ strv_free(i->machine_info);
+ strv_free(i->os_release);
+ strv_free(i->extension_release);
+
+ return mfree(i);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(Image, image, image_free);
+DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(image_hash_ops, char, string_hash_func, string_compare_func,
+ Image, image_unref);
+
+static char **image_settings_path(Image *image) {
+ _cleanup_strv_free_ char **l = NULL;
+ const char *fn;
+ unsigned i = 0;
+
+ assert(image);
+
+ l = new0(char*, 4);
+ if (!l)
+ return NULL;
+
+ fn = strjoina(image->name, ".nspawn");
+
+ FOREACH_STRING(s, "/etc/systemd/nspawn", "/run/systemd/nspawn") {
+ l[i] = path_join(s, fn);
+ if (!l[i])
+ return NULL;
+
+ i++;
+ }
+
+ l[i] = file_in_same_dir(image->path, fn);
+ if (!l[i])
+ return NULL;
+
+ return TAKE_PTR(l);
+}
+
+static char *image_roothash_path(Image *image) {
+ const char *fn;
+
+ assert(image);
+
+ fn = strjoina(image->name, ".roothash");
+
+ return file_in_same_dir(image->path, fn);
+}
+
+static int image_new(
+ ImageType t,
+ const char *pretty,
+ const char *path,
+ const char *filename,
+ bool read_only,
+ usec_t crtime,
+ usec_t mtime,
+ Image **ret) {
+
+ _cleanup_(image_unrefp) Image *i = NULL;
+
+ assert(t >= 0);
+ assert(t < _IMAGE_TYPE_MAX);
+ assert(pretty);
+ assert(filename);
+ assert(ret);
+
+ i = new(Image, 1);
+ if (!i)
+ return -ENOMEM;
+
+ *i = (Image) {
+ .n_ref = 1,
+ .type = t,
+ .read_only = read_only,
+ .crtime = crtime,
+ .mtime = mtime,
+ .usage = UINT64_MAX,
+ .usage_exclusive = UINT64_MAX,
+ .limit = UINT64_MAX,
+ .limit_exclusive = UINT64_MAX,
+ };
+
+ i->name = strdup(pretty);
+ if (!i->name)
+ return -ENOMEM;
+
+ i->path = path_join(path, filename);
+ if (!i->path)
+ return -ENOMEM;
+
+ path_simplify(i->path);
+
+ *ret = TAKE_PTR(i);
+
+ return 0;
+}
+
+static int extract_pretty(const char *path, const char *suffix, char **ret) {
+ _cleanup_free_ char *name = NULL;
+ const char *p;
+ size_t n;
+
+ assert(path);
+ assert(ret);
+
+ p = last_path_component(path);
+ n = strcspn(p, "/");
+
+ name = strndup(p, n);
+ if (!name)
+ return -ENOMEM;
+
+ if (suffix) {
+ char *e;
+
+ e = endswith(name, suffix);
+ if (!e)
+ return -EINVAL;
+
+ *e = 0;
+ }
+
+ if (!image_name_is_valid(name))
+ return -EINVAL;
+
+ *ret = TAKE_PTR(name);
+ return 0;
+}
+
+static int image_make(
+ const char *pretty,
+ int dfd,
+ const char *path,
+ const char *filename,
+ const struct stat *st,
+ Image **ret) {
+
+ _cleanup_free_ char *pretty_buffer = NULL, *parent = NULL;
+ struct stat stbuf;
+ bool read_only;
+ int r;
+
+ assert(dfd >= 0 || dfd == AT_FDCWD);
+ assert(path || dfd == AT_FDCWD);
+ assert(filename);
+
+ /* We explicitly *do* follow symlinks here, since we want to allow symlinking trees, raw files and block
+ * devices into /var/lib/machines/, and treat them normally.
+ *
+ * This function returns -ENOENT if we can't find the image after all, and -EMEDIUMTYPE if it's not a file we
+ * recognize. */
+
+ if (!st) {
+ if (fstatat(dfd, filename, &stbuf, 0) < 0)
+ return -errno;
+
+ st = &stbuf;
+ }
+
+ if (!path) {
+ if (dfd == AT_FDCWD)
+ (void) safe_getcwd(&parent);
+ else
+ (void) fd_get_path(dfd, &parent);
+ }
+
+ read_only =
+ (path && path_startswith(path, "/usr")) ||
+ (faccessat(dfd, filename, W_OK, AT_EACCESS) < 0 && errno == EROFS);
+
+ if (S_ISDIR(st->st_mode)) {
+ _cleanup_close_ int fd = -1;
+ unsigned file_attr = 0;
+ usec_t crtime = 0;
+
+ if (!ret)
+ return 0;
+
+ if (!pretty) {
+ r = extract_pretty(filename, NULL, &pretty_buffer);
+ if (r < 0)
+ return r;
+
+ pretty = pretty_buffer;
+ }
+
+ fd = openat(dfd, filename, O_CLOEXEC|O_NOCTTY|O_DIRECTORY);
+ if (fd < 0)
+ return -errno;
+
+ if (btrfs_might_be_subvol(st)) {
+
+ r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC);
+ if (r < 0)
+ return r;
+ if (r) {
+ BtrfsSubvolInfo info;
+
+ /* It's a btrfs subvolume */
+
+ r = btrfs_subvol_get_info_fd(fd, 0, &info);
+ if (r < 0)
+ return r;
+
+ r = image_new(IMAGE_SUBVOLUME,
+ pretty,
+ path,
+ filename,
+ info.read_only || read_only,
+ info.otime,
+ 0,
+ ret);
+ if (r < 0)
+ return r;
+
+ if (btrfs_quota_scan_ongoing(fd) == 0) {
+ BtrfsQuotaInfo quota;
+
+ r = btrfs_subvol_get_subtree_quota_fd(fd, 0, &quota);
+ if (r >= 0) {
+ (*ret)->usage = quota.referenced;
+ (*ret)->usage_exclusive = quota.exclusive;
+
+ (*ret)->limit = quota.referenced_max;
+ (*ret)->limit_exclusive = quota.exclusive_max;
+ }
+ }
+
+ return 0;
+ }
+ }
+
+ /* Get directory creation time (not available everywhere, but that's OK */
+ (void) fd_getcrtime(fd, &crtime);
+
+ /* If the IMMUTABLE bit is set, we consider the directory read-only. Since the ioctl is not
+ * supported everywhere we ignore failures. */
+ (void) read_attr_fd(fd, &file_attr);
+
+ /* It's just a normal directory. */
+ r = image_new(IMAGE_DIRECTORY,
+ pretty,
+ path,
+ filename,
+ read_only || (file_attr & FS_IMMUTABLE_FL),
+ crtime,
+ 0, /* we don't use mtime of stat() here, since it's not the time of last change of the tree, but only of the top-level dir */
+ ret);
+ if (r < 0)
+ return r;
+
+ return 0;
+
+ } else if (S_ISREG(st->st_mode) && endswith(filename, ".raw")) {
+ usec_t crtime = 0;
+
+ /* It's a RAW disk image */
+
+ if (!ret)
+ return 0;
+
+ (void) fd_getcrtime_at(dfd, filename, AT_SYMLINK_FOLLOW, &crtime);
+
+ if (!pretty) {
+ r = extract_pretty(filename, ".raw", &pretty_buffer);
+ if (r < 0)
+ return r;
+
+ pretty = pretty_buffer;
+ }
+
+ r = image_new(IMAGE_RAW,
+ pretty,
+ path,
+ filename,
+ !(st->st_mode & 0222) || read_only,
+ crtime,
+ timespec_load(&st->st_mtim),
+ ret);
+ if (r < 0)
+ return r;
+
+ (*ret)->usage = (*ret)->usage_exclusive = st->st_blocks * 512;
+ (*ret)->limit = (*ret)->limit_exclusive = st->st_size;
+
+ return 0;
+
+ } else if (S_ISBLK(st->st_mode)) {
+ _cleanup_close_ int block_fd = -1;
+ uint64_t size = UINT64_MAX;
+
+ /* A block device */
+
+ if (!ret)
+ return 0;
+
+ if (!pretty) {
+ r = extract_pretty(filename, NULL, &pretty_buffer);
+ if (r < 0)
+ return r;
+
+ pretty = pretty_buffer;
+ }
+
+ block_fd = openat(dfd, filename, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY);
+ if (block_fd < 0)
+ log_debug_errno(errno, "Failed to open block device %s/%s, ignoring: %m", path ?: strnull(parent), filename);
+ else {
+ /* Refresh stat data after opening the node */
+ if (fstat(block_fd, &stbuf) < 0)
+ return -errno;
+ st = &stbuf;
+
+ if (!S_ISBLK(st->st_mode)) /* Verify that what we opened is actually what we think it is */
+ return -ENOTTY;
+
+ if (!read_only) {
+ int state = 0;
+
+ if (ioctl(block_fd, BLKROGET, &state) < 0)
+ log_debug_errno(errno, "Failed to issue BLKROGET on device %s/%s, ignoring: %m", path ?: strnull(parent), filename);
+ else if (state)
+ read_only = true;
+ }
+
+ if (ioctl(block_fd, BLKGETSIZE64, &size) < 0)
+ log_debug_errno(errno, "Failed to issue BLKGETSIZE64 on device %s/%s, ignoring: %m", path ?: strnull(parent), filename);
+
+ block_fd = safe_close(block_fd);
+ }
+
+ r = image_new(IMAGE_BLOCK,
+ pretty,
+ path,
+ filename,
+ !(st->st_mode & 0222) || read_only,
+ 0,
+ 0,
+ ret);
+ if (r < 0)
+ return r;
+
+ if (!IN_SET(size, 0, UINT64_MAX))
+ (*ret)->usage = (*ret)->usage_exclusive = (*ret)->limit = (*ret)->limit_exclusive = size;
+
+ return 0;
+ }
+
+ return -EMEDIUMTYPE;
+}
+
+int image_find(ImageClass class,
+ const char *name,
+ const char *root,
+ Image **ret) {
+
+ const char *path;
+ int r;
+
+ assert(class >= 0);
+ assert(class < _IMAGE_CLASS_MAX);
+ assert(name);
+
+ /* There are no images with invalid names */
+ if (!image_name_is_valid(name))
+ return -ENOENT;
+
+ NULSTR_FOREACH(path, image_search_path[class]) {
+ _cleanup_free_ char *resolved = NULL;
+ _cleanup_closedir_ DIR *d = NULL;
+ struct stat st;
+ int flags;
+
+ r = chase_symlinks_and_opendir(path, root, CHASE_PREFIX_ROOT, &resolved, &d);
+ if (r == -ENOENT)
+ continue;
+ if (r < 0)
+ return r;
+
+ /* As mentioned above, we follow symlinks on this fstatat(), because we want to permit people
+ * to symlink block devices into the search path. (For now, we disable that when operating
+ * relative to some root directory.) */
+ flags = root ? AT_SYMLINK_NOFOLLOW : 0;
+ if (fstatat(dirfd(d), name, &st, flags) < 0) {
+ _cleanup_free_ char *raw = NULL;
+
+ if (errno != ENOENT)
+ return -errno;
+
+ raw = strjoin(name, ".raw");
+ if (!raw)
+ return -ENOMEM;
+
+ if (fstatat(dirfd(d), raw, &st, flags) < 0) {
+ if (errno == ENOENT)
+ continue;
+
+ return -errno;
+ }
+
+ if (!S_ISREG(st.st_mode))
+ continue;
+
+ r = image_make(name, dirfd(d), resolved, raw, &st, ret);
+
+ } else {
+ if (!S_ISDIR(st.st_mode) && !S_ISBLK(st.st_mode))
+ continue;
+
+ r = image_make(name, dirfd(d), resolved, name, &st, ret);
+ }
+ if (IN_SET(r, -ENOENT, -EMEDIUMTYPE))
+ continue;
+ if (r < 0)
+ return r;
+
+ if (ret)
+ (*ret)->discoverable = true;
+
+ return 1;
+ }
+
+ if (class == IMAGE_MACHINE && streq(name, ".host")) {
+ r = image_make(".host", AT_FDCWD, NULL, empty_to_root(root), NULL, ret);
+ if (r < 0)
+ return r;
+
+ if (ret)
+ (*ret)->discoverable = true;
+
+ return r;
+ }
+
+ return -ENOENT;
+};
+
+int image_from_path(const char *path, Image **ret) {
+
+ /* Note that we don't set the 'discoverable' field of the returned object, because we don't check here whether
+ * the image is in the image search path. And if it is we don't know if the path we used is actually not
+ * overridden by another, different image earlier in the search path */
+
+ if (path_equal(path, "/"))
+ return image_make(".host", AT_FDCWD, NULL, "/", NULL, ret);
+
+ return image_make(NULL, AT_FDCWD, NULL, path, NULL, ret);
+}
+
+int image_find_harder(ImageClass class, const char *name_or_path, const char *root, Image **ret) {
+ if (image_name_is_valid(name_or_path))
+ return image_find(class, name_or_path, root, ret);
+
+ return image_from_path(name_or_path, ret);
+}
+
+int image_discover(
+ ImageClass class,
+ const char *root,
+ Hashmap *h) {
+
+ const char *path;
+ int r;
+
+ assert(class >= 0);
+ assert(class < _IMAGE_CLASS_MAX);
+ assert(h);
+
+ NULSTR_FOREACH(path, image_search_path[class]) {
+ _cleanup_free_ char *resolved = NULL;
+ _cleanup_closedir_ DIR *d = NULL;
+
+ r = chase_symlinks_and_opendir(path, root, CHASE_PREFIX_ROOT, &resolved, &d);
+ if (r == -ENOENT)
+ continue;
+ if (r < 0)
+ return r;
+
+ FOREACH_DIRENT_ALL(de, d, return -errno) {
+ _cleanup_(image_unrefp) Image *image = NULL;
+ _cleanup_free_ char *truncated = NULL;
+ const char *pretty;
+ struct stat st;
+ int flags;
+
+ if (dot_or_dot_dot(de->d_name))
+ continue;
+
+ /* As mentioned above, we follow symlinks on this fstatat(), because we want to
+ * permit people to symlink block devices into the search path. */
+ flags = root ? AT_SYMLINK_NOFOLLOW : 0;
+ if (fstatat(dirfd(d), de->d_name, &st, flags) < 0) {
+ if (errno == ENOENT)
+ continue;
+
+ return -errno;
+ }
+
+ if (S_ISREG(st.st_mode)) {
+ const char *e;
+
+ e = endswith(de->d_name, ".raw");
+ if (!e)
+ continue;
+
+ truncated = strndup(de->d_name, e - de->d_name);
+ if (!truncated)
+ return -ENOMEM;
+
+ pretty = truncated;
+ } else if (S_ISDIR(st.st_mode) || S_ISBLK(st.st_mode))
+ pretty = de->d_name;
+ else
+ continue;
+
+ if (!image_name_is_valid(pretty))
+ continue;
+
+ if (hashmap_contains(h, pretty))
+ continue;
+
+ r = image_make(pretty, dirfd(d), resolved, de->d_name, &st, &image);
+ if (IN_SET(r, -ENOENT, -EMEDIUMTYPE))
+ continue;
+ if (r < 0)
+ return r;
+
+ image->discoverable = true;
+
+ r = hashmap_put(h, image->name, image);
+ if (r < 0)
+ return r;
+
+ image = NULL;
+ }
+ }
+
+ if (class == IMAGE_MACHINE && !hashmap_contains(h, ".host")) {
+ _cleanup_(image_unrefp) Image *image = NULL;
+
+ r = image_make(".host", AT_FDCWD, NULL, empty_to_root("/"), NULL, &image);
+ if (r < 0)
+ return r;
+
+ image->discoverable = true;
+
+ r = hashmap_put(h, image->name, image);
+ if (r < 0)
+ return r;
+
+ image = NULL;
+ }
+
+ return 0;
+}
+
+int image_remove(Image *i) {
+ _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
+ _cleanup_strv_free_ char **settings = NULL;
+ _cleanup_free_ char *roothash = NULL;
+ int r;
+
+ assert(i);
+
+ if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+ return -EROFS;
+
+ settings = image_settings_path(i);
+ if (!settings)
+ return -ENOMEM;
+
+ roothash = image_roothash_path(i);
+ if (!roothash)
+ return -ENOMEM;
+
+ /* Make sure we don't interfere with a running nspawn */
+ r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
+ if (r < 0)
+ return r;
+
+ switch (i->type) {
+
+ case IMAGE_SUBVOLUME:
+
+ /* Let's unlink first, maybe it is a symlink? If that works we are happy. Otherwise, let's get out the
+ * big guns */
+ if (unlink(i->path) < 0) {
+ r = btrfs_subvol_remove(i->path, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
+ if (r < 0)
+ return r;
+ }
+
+ break;
+
+ case IMAGE_DIRECTORY:
+ /* Allow deletion of read-only directories */
+ (void) chattr_path(i->path, 0, FS_IMMUTABLE_FL, NULL);
+ r = rm_rf(i->path, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case IMAGE_BLOCK:
+
+ /* If this is inside of /dev, then it's a real block device, hence let's not touch the device node
+ * itself (but let's remove the stuff stored alongside it). If it's anywhere else, let's try to unlink
+ * the thing (it's most likely a symlink after all). */
+
+ if (path_startswith(i->path, "/dev"))
+ break;
+
+ _fallthrough_;
+ case IMAGE_RAW:
+ if (unlink(i->path) < 0)
+ return -errno;
+ break;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ STRV_FOREACH(j, settings)
+ if (unlink(*j) < 0 && errno != ENOENT)
+ log_debug_errno(errno, "Failed to unlink %s, ignoring: %m", *j);
+
+ if (unlink(roothash) < 0 && errno != ENOENT)
+ log_debug_errno(errno, "Failed to unlink %s, ignoring: %m", roothash);
+
+ return 0;
+}
+
+static int rename_auxiliary_file(const char *path, const char *new_name, const char *suffix) {
+ _cleanup_free_ char *rs = NULL;
+ const char *fn;
+
+ fn = strjoina(new_name, suffix);
+
+ rs = file_in_same_dir(path, fn);
+ if (!rs)
+ return -ENOMEM;
+
+ return rename_noreplace(AT_FDCWD, path, AT_FDCWD, rs);
+}
+
+int image_rename(Image *i, const char *new_name) {
+ _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT, name_lock = LOCK_FILE_INIT;
+ _cleanup_free_ char *new_path = NULL, *nn = NULL, *roothash = NULL;
+ _cleanup_strv_free_ char **settings = NULL;
+ unsigned file_attr = 0;
+ int r;
+
+ assert(i);
+
+ if (!image_name_is_valid(new_name))
+ return -EINVAL;
+
+ if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+ return -EROFS;
+
+ settings = image_settings_path(i);
+ if (!settings)
+ return -ENOMEM;
+
+ roothash = image_roothash_path(i);
+ if (!roothash)
+ return -ENOMEM;
+
+ /* Make sure we don't interfere with a running nspawn */
+ r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
+ if (r < 0)
+ return r;
+
+ /* Make sure nobody takes the new name, between the time we
+ * checked it is currently unused in all search paths, and the
+ * time we take possession of it */
+ r = image_name_lock(new_name, LOCK_EX|LOCK_NB, &name_lock);
+ if (r < 0)
+ return r;
+
+ r = image_find(IMAGE_MACHINE, new_name, NULL, NULL);
+ if (r >= 0)
+ return -EEXIST;
+ if (r != -ENOENT)
+ return r;
+
+ switch (i->type) {
+
+ case IMAGE_DIRECTORY:
+ /* Turn of the immutable bit while we rename the image, so that we can rename it */
+ (void) read_attr_path(i->path, &file_attr);
+
+ if (file_attr & FS_IMMUTABLE_FL)
+ (void) chattr_path(i->path, 0, FS_IMMUTABLE_FL, NULL);
+
+ _fallthrough_;
+ case IMAGE_SUBVOLUME:
+ new_path = file_in_same_dir(i->path, new_name);
+ break;
+
+ case IMAGE_BLOCK:
+
+ /* Refuse renaming raw block devices in /dev, the names are picked by udev after all. */
+ if (path_startswith(i->path, "/dev"))
+ return -EROFS;
+
+ new_path = file_in_same_dir(i->path, new_name);
+ break;
+
+ case IMAGE_RAW: {
+ const char *fn;
+
+ fn = strjoina(new_name, ".raw");
+ new_path = file_in_same_dir(i->path, fn);
+ break;
+ }
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ if (!new_path)
+ return -ENOMEM;
+
+ nn = strdup(new_name);
+ if (!nn)
+ return -ENOMEM;
+
+ r = rename_noreplace(AT_FDCWD, i->path, AT_FDCWD, new_path);
+ if (r < 0)
+ return r;
+
+ /* Restore the immutable bit, if it was set before */
+ if (file_attr & FS_IMMUTABLE_FL)
+ (void) chattr_path(new_path, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL, NULL);
+
+ free_and_replace(i->path, new_path);
+ free_and_replace(i->name, nn);
+
+ STRV_FOREACH(j, settings) {
+ r = rename_auxiliary_file(*j, new_name, ".nspawn");
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to rename settings file %s, ignoring: %m", *j);
+ }
+
+ r = rename_auxiliary_file(roothash, new_name, ".roothash");
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to rename roothash file %s, ignoring: %m", roothash);
+
+ return 0;
+}
+
+static int clone_auxiliary_file(const char *path, const char *new_name, const char *suffix) {
+ _cleanup_free_ char *rs = NULL;
+ const char *fn;
+
+ fn = strjoina(new_name, suffix);
+
+ rs = file_in_same_dir(path, fn);
+ if (!rs)
+ return -ENOMEM;
+
+ return copy_file_atomic(path, rs, 0664, 0, 0, COPY_REFLINK);
+}
+
+int image_clone(Image *i, const char *new_name, bool read_only) {
+ _cleanup_(release_lock_file) LockFile name_lock = LOCK_FILE_INIT;
+ _cleanup_strv_free_ char **settings = NULL;
+ _cleanup_free_ char *roothash = NULL;
+ const char *new_path;
+ int r;
+
+ assert(i);
+
+ if (!image_name_is_valid(new_name))
+ return -EINVAL;
+
+ settings = image_settings_path(i);
+ if (!settings)
+ return -ENOMEM;
+
+ roothash = image_roothash_path(i);
+ if (!roothash)
+ return -ENOMEM;
+
+ /* Make sure nobody takes the new name, between the time we
+ * checked it is currently unused in all search paths, and the
+ * time we take possession of it */
+ r = image_name_lock(new_name, LOCK_EX|LOCK_NB, &name_lock);
+ if (r < 0)
+ return r;
+
+ r = image_find(IMAGE_MACHINE, new_name, NULL, NULL);
+ if (r >= 0)
+ return -EEXIST;
+ if (r != -ENOENT)
+ return r;
+
+ switch (i->type) {
+
+ case IMAGE_SUBVOLUME:
+ case IMAGE_DIRECTORY:
+ /* If we can we'll always try to create a new btrfs subvolume here, even if the source is a plain
+ * directory. */
+
+ new_path = strjoina("/var/lib/machines/", new_name);
+
+ r = btrfs_subvol_snapshot(i->path, new_path,
+ (read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
+ BTRFS_SNAPSHOT_FALLBACK_COPY |
+ BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
+ BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE |
+ BTRFS_SNAPSHOT_RECURSIVE |
+ BTRFS_SNAPSHOT_QUOTA);
+ if (r >= 0)
+ /* Enable "subtree" quotas for the copy, if we didn't copy any quota from the source. */
+ (void) btrfs_subvol_auto_qgroup(new_path, 0, true);
+
+ break;
+
+ case IMAGE_RAW:
+ new_path = strjoina("/var/lib/machines/", new_name, ".raw");
+
+ r = copy_file_atomic(i->path, new_path, read_only ? 0444 : 0644, FS_NOCOW_FL, FS_NOCOW_FL, COPY_REFLINK|COPY_CRTIME);
+ break;
+
+ case IMAGE_BLOCK:
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ if (r < 0)
+ return r;
+
+ STRV_FOREACH(j, settings) {
+ r = clone_auxiliary_file(*j, new_name, ".nspawn");
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to clone settings %s, ignoring: %m", *j);
+ }
+
+ r = clone_auxiliary_file(roothash, new_name, ".roothash");
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to clone root hash file %s, ignoring: %m", roothash);
+
+ return 0;
+}
+
+int image_read_only(Image *i, bool b) {
+ _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
+ int r;
+
+ assert(i);
+
+ if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+ return -EROFS;
+
+ /* Make sure we don't interfere with a running nspawn */
+ r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
+ if (r < 0)
+ return r;
+
+ switch (i->type) {
+
+ case IMAGE_SUBVOLUME:
+
+ /* Note that we set the flag only on the top-level
+ * subvolume of the image. */
+
+ r = btrfs_subvol_set_read_only(i->path, b);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case IMAGE_DIRECTORY:
+ /* For simple directory trees we cannot use the access
+ mode of the top-level directory, since it has an
+ effect on the container itself. However, we can
+ use the "immutable" flag, to at least make the
+ top-level directory read-only. It's not as good as
+ a read-only subvolume, but at least something, and
+ we can read the value back. */
+
+ r = chattr_path(i->path, b ? FS_IMMUTABLE_FL : 0, FS_IMMUTABLE_FL, NULL);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case IMAGE_RAW: {
+ struct stat st;
+
+ if (stat(i->path, &st) < 0)
+ return -errno;
+
+ if (chmod(i->path, (st.st_mode & 0444) | (b ? 0000 : 0200)) < 0)
+ return -errno;
+
+ /* If the images is now read-only, it's a good time to
+ * defrag it, given that no write patterns will
+ * fragment it again. */
+ if (b)
+ (void) btrfs_defrag(i->path);
+ break;
+ }
+
+ case IMAGE_BLOCK: {
+ _cleanup_close_ int fd = -1;
+ struct stat st;
+ int state = b;
+
+ fd = open(i->path, O_CLOEXEC|O_RDONLY|O_NONBLOCK|O_NOCTTY);
+ if (fd < 0)
+ return -errno;
+
+ if (fstat(fd, &st) < 0)
+ return -errno;
+ if (!S_ISBLK(st.st_mode))
+ return -ENOTTY;
+
+ if (ioctl(fd, BLKROSET, &state) < 0)
+ return -errno;
+
+ break;
+ }
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static void make_lock_dir(void) {
+ (void) mkdir_p("/run/systemd/nspawn", 0755);
+ (void) mkdir("/run/systemd/nspawn/locks", 0700);
+}
+
+int image_path_lock(const char *path, int operation, LockFile *global, LockFile *local) {
+ _cleanup_free_ char *p = NULL;
+ LockFile t = LOCK_FILE_INIT;
+ struct stat st;
+ bool exclusive;
+ int r;
+
+ assert(path);
+ assert(global);
+ assert(local);
+
+ /* Locks an image path. This actually creates two locks: one "local" one, next to the image path
+ * itself, which might be shared via NFS. And another "global" one, in /run, that uses the
+ * device/inode number. This has the benefit that we can even lock a tree that is a mount point,
+ * correctly. */
+
+ if (!path_is_absolute(path))
+ return -EINVAL;
+
+ switch (operation & (LOCK_SH|LOCK_EX)) {
+ case LOCK_SH:
+ exclusive = false;
+ break;
+ case LOCK_EX:
+ exclusive = true;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (getenv_bool("SYSTEMD_NSPAWN_LOCK") == 0) {
+ *local = *global = (LockFile) LOCK_FILE_INIT;
+ return 0;
+ }
+
+ /* Prohibit taking exclusive locks on the host image. We can't allow this, since we ourselves are
+ * running off it after all, and we don't want any images to manipulate the host image. We make an
+ * exception for shared locks however: we allow those (and make them NOPs since there's no point in
+ * taking them if there can't be exclusive locks). Strictly speaking these are questionable as well,
+ * since it means changes made to the host might propagate to the container as they happen (and a
+ * shared lock kinda suggests that no changes happen at all while it is in place), but it's too
+ * useful not to allow read-only containers off the host root, hence let's support this, and trust
+ * the user to do the right thing with this. */
+ if (path_equal(path, "/")) {
+ if (exclusive)
+ return -EBUSY;
+
+ *local = *global = (LockFile) LOCK_FILE_INIT;
+ return 0;
+ }
+
+ if (stat(path, &st) >= 0) {
+ if (S_ISBLK(st.st_mode))
+ r = asprintf(&p, "/run/systemd/nspawn/locks/block-%u:%u", major(st.st_rdev), minor(st.st_rdev));
+ else if (S_ISDIR(st.st_mode) || S_ISREG(st.st_mode))
+ r = asprintf(&p, "/run/systemd/nspawn/locks/inode-%lu:%lu", (unsigned long) st.st_dev, (unsigned long) st.st_ino);
+ else
+ return -ENOTTY;
+ if (r < 0)
+ return -ENOMEM;
+ }
+
+ /* For block devices we don't need the "local" lock, as the major/minor lock above should be
+ * sufficient, since block devices are host local anyway. */
+ if (!path_startswith(path, "/dev/")) {
+ r = make_lock_file_for(path, operation, &t);
+ if (r < 0) {
+ if (!exclusive && r == -EROFS)
+ log_debug_errno(r, "Failed to create shared lock for '%s', ignoring: %m", path);
+ else
+ return r;
+ }
+ }
+
+ if (p) {
+ make_lock_dir();
+
+ r = make_lock_file(p, operation, global);
+ if (r < 0) {
+ release_lock_file(&t);
+ return r;
+ }
+ } else
+ *global = (LockFile) LOCK_FILE_INIT;
+
+ *local = t;
+ return 0;
+}
+
+int image_set_limit(Image *i, uint64_t referenced_max) {
+ assert(i);
+
+ if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+ return -EROFS;
+
+ if (i->type != IMAGE_SUBVOLUME)
+ return -EOPNOTSUPP;
+
+ /* We set the quota both for the subvolume as well as for the
+ * subtree. The latter is mostly for historical reasons, since
+ * we didn't use to have a concept of subtree quota, and hence
+ * only modified the subvolume quota. */
+
+ (void) btrfs_qgroup_set_limit(i->path, 0, referenced_max);
+ (void) btrfs_subvol_auto_qgroup(i->path, 0, true);
+ return btrfs_subvol_set_subtree_quota_limit(i->path, 0, referenced_max);
+}
+
+int image_read_metadata(Image *i) {
+ _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
+ int r;
+
+ assert(i);
+
+ r = image_path_lock(i->path, LOCK_SH|LOCK_NB, &global_lock, &local_lock);
+ if (r < 0)
+ return r;
+
+ switch (i->type) {
+
+ case IMAGE_SUBVOLUME:
+ case IMAGE_DIRECTORY: {
+ _cleanup_strv_free_ char **machine_info = NULL, **os_release = NULL, **extension_release = NULL;
+ sd_id128_t machine_id = SD_ID128_NULL;
+ _cleanup_free_ char *hostname = NULL;
+ _cleanup_free_ char *path = NULL;
+
+ r = chase_symlinks("/etc/hostname", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path, NULL);
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to chase /etc/hostname in image %s: %m", i->name);
+ else if (r >= 0) {
+ r = read_etc_hostname(path, &hostname);
+ if (r < 0)
+ log_debug_errno(errno, "Failed to read /etc/hostname of image %s: %m", i->name);
+ }
+
+ path = mfree(path);
+
+ r = chase_symlinks("/etc/machine-id", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path, NULL);
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to chase /etc/machine-id in image %s: %m", i->name);
+ else if (r >= 0) {
+ _cleanup_close_ int fd = -1;
+
+ fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0)
+ log_debug_errno(errno, "Failed to open %s: %m", path);
+ else {
+ r = id128_read_fd(fd, ID128_FORMAT_PLAIN, &machine_id);
+ if (r < 0)
+ log_debug_errno(r, "Image %s contains invalid machine ID.", i->name);
+ }
+ }
+
+ path = mfree(path);
+
+ r = chase_symlinks("/etc/machine-info", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path, NULL);
+ if (r < 0 && r != -ENOENT)
+ log_debug_errno(r, "Failed to chase /etc/machine-info in image %s: %m", i->name);
+ else if (r >= 0) {
+ r = load_env_file_pairs(NULL, path, &machine_info);
+ if (r < 0)
+ log_debug_errno(r, "Failed to parse machine-info data of %s: %m", i->name);
+ }
+
+ r = load_os_release_pairs(i->path, &os_release);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read os-release in image, ignoring: %m");
+
+ r = load_extension_release_pairs(i->path, i->name, /* relax_extension_release_check= */ false, &extension_release);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read extension-release in image, ignoring: %m");
+
+ free_and_replace(i->hostname, hostname);
+ i->machine_id = machine_id;
+ strv_free_and_replace(i->machine_info, machine_info);
+ strv_free_and_replace(i->os_release, os_release);
+ strv_free_and_replace(i->extension_release, extension_release);
+
+ break;
+ }
+
+ case IMAGE_RAW:
+ case IMAGE_BLOCK: {
+ _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
+ _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
+
+ r = loop_device_make_by_path(i->path, O_RDONLY, LO_FLAGS_PARTSCAN, LOCK_SH, &d);
+ if (r < 0)
+ return r;
+
+ r = dissect_loop_device(
+ d,
+ NULL, NULL,
+ DISSECT_IMAGE_GENERIC_ROOT |
+ DISSECT_IMAGE_REQUIRE_ROOT |
+ DISSECT_IMAGE_RELAX_VAR_CHECK |
+ DISSECT_IMAGE_READ_ONLY |
+ DISSECT_IMAGE_USR_NO_ROOT |
+ DISSECT_IMAGE_ADD_PARTITION_DEVICES |
+ DISSECT_IMAGE_PIN_PARTITION_DEVICES,
+ &m);
+ if (r < 0)
+ return r;
+
+ r = dissected_image_acquire_metadata(m,
+ DISSECT_IMAGE_VALIDATE_OS |
+ DISSECT_IMAGE_VALIDATE_OS_EXT);
+ if (r < 0)
+ return r;
+
+ free_and_replace(i->hostname, m->hostname);
+ i->machine_id = m->machine_id;
+ strv_free_and_replace(i->machine_info, m->machine_info);
+ strv_free_and_replace(i->os_release, m->os_release);
+ strv_free_and_replace(i->extension_release, m->extension_release);
+
+ break;
+ }
+
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ i->metadata_valid = true;
+
+ return 0;
+}
+
+int image_name_lock(const char *name, int operation, LockFile *ret) {
+ const char *p;
+
+ assert(name);
+ assert(ret);
+
+ /* Locks an image name, regardless of the precise path used. */
+
+ if (streq(name, ".host"))
+ return -EBUSY;
+
+ if (!image_name_is_valid(name))
+ return -EINVAL;
+
+ if (getenv_bool("SYSTEMD_NSPAWN_LOCK") == 0) {
+ *ret = (LockFile) LOCK_FILE_INIT;
+ return 0;
+ }
+
+ make_lock_dir();
+
+ p = strjoina("/run/systemd/nspawn/locks/name-", name);
+ return make_lock_file(p, operation, ret);
+}
+
+bool image_in_search_path(
+ ImageClass class,
+ const char *root,
+ const char *image) {
+
+ const char *path;
+
+ assert(image);
+
+ NULSTR_FOREACH(path, image_search_path[class]) {
+ const char *p, *q;
+ size_t k;
+
+ if (!empty_or_root(root)) {
+ q = path_startswith(path, root);
+ if (!q)
+ continue;
+ } else
+ q = path;
+
+ p = path_startswith(q, path);
+ if (!p)
+ continue;
+
+ /* Make sure there's a filename following */
+ k = strcspn(p, "/");
+ if (k == 0)
+ continue;
+
+ p += k;
+
+ /* Accept trailing slashes */
+ if (p[strspn(p, "/")] == 0)
+ return true;
+ }
+
+ return false;
+}
+
+static const char* const image_type_table[_IMAGE_TYPE_MAX] = {
+ [IMAGE_DIRECTORY] = "directory",
+ [IMAGE_SUBVOLUME] = "subvolume",
+ [IMAGE_RAW] = "raw",
+ [IMAGE_BLOCK] = "block",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(image_type, ImageType);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 04:05:13 +0000