/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "alloc-util.h"
+#include "chase-symlinks.h"
+#include "dirent-util.h"
#include "env-file.h"
#include "env-util.h"
#include "fd-util.h"
#include "fs-util.h"
#include "macro.h"
#include "os-util.h"
+#include "parse-util.h"
#include "path-util.h"
+#include "stat-util.h"
#include "string-util.h"
#include "strv.h"
#include "utf8.h"
+#include "xattr-util.h"
bool image_name_is_valid(const char *s) {
if (!filename_is_valid(s))
if (laccess(path, F_OK) < 0)
return -errno;
- /* We use /usr/lib/extension-release.d/extension-release.NAME as flag file if something is a system extension,
- * and {/etc|/usr/lib}/os-release as flag file if something is an OS (in case extension == NULL) */
+ /* We use /usr/lib/extension-release.d/extension-release[.NAME] as flag for something being a system extension,
+ * and {/etc|/usr/lib}/os-release as a flag for something being an OS (when not an extension). */
r = open_extension_release(path, extension, NULL, NULL);
if (r == -ENOENT) /* We got nothing */
return 0;
r = chase_symlinks(extension_full_path, root, CHASE_PREFIX_ROOT,
ret_path ? &q : NULL,
ret_fd ? &fd : NULL);
+ log_full_errno_zerook(LOG_DEBUG, MIN(r, 0), "Checking for %s: %m", extension_full_path);
+
+ /* Cannot find the expected extension-release file? The image filename might have been
+ * mangled on deployment, so fallback to checking for any file in the extension-release.d
+ * directory, and return the first one with a user.extension-release xattr instead.
+ * The user.extension-release.strict xattr is checked to ensure the author of the image
+ * considers it OK if names do not match. */
+ if (r == -ENOENT) {
+ _cleanup_free_ char *extension_release_dir_path = NULL;
+ _cleanup_closedir_ DIR *extension_release_dir = NULL;
+
+ r = chase_symlinks_and_opendir("/usr/lib/extension-release.d/", root, CHASE_PREFIX_ROOT,
+ &extension_release_dir_path, &extension_release_dir);
+ if (r < 0)
+ return log_debug_errno(r, "Cannot open %s/usr/lib/extension-release.d/, ignoring: %m", root);
+
+ r = -ENOENT;
+ FOREACH_DIRENT(de, extension_release_dir, return -errno) {
+ int k;
+
+ if (!IN_SET(de->d_type, DT_REG, DT_UNKNOWN))
+ continue;
+
+ const char *image_name = startswith(de->d_name, "extension-release.");
+ if (!image_name)
+ continue;
+
+ if (!image_name_is_valid(image_name)) {
+ log_debug("%s/%s is not a valid extension-release file name, ignoring.",
+ extension_release_dir_path, de->d_name);
+ continue;
+ }
+
+ /* We already chased the directory, and checked that
+ * this is a real file, so we shouldn't fail to open it. */
+ _cleanup_close_ int extension_release_fd = openat(dirfd(extension_release_dir),
+ de->d_name,
+ O_PATH|O_CLOEXEC|O_NOFOLLOW);
+ if (extension_release_fd < 0)
+ return log_debug_errno(errno,
+ "Failed to open extension-release file %s/%s: %m",
+ extension_release_dir_path,
+ de->d_name);
+
+ /* Really ensure it is a regular file after we open it. */
+ if (fd_verify_regular(extension_release_fd) < 0) {
+ log_debug("%s/%s is not a regular file, ignoring.", extension_release_dir_path, de->d_name);
+ continue;
+ }
+
+ /* No xattr or cannot parse it? Then skip this. */
+ _cleanup_free_ char *extension_release_xattr = NULL;
+ k = fgetxattr_malloc(extension_release_fd, "user.extension-release.strict", &extension_release_xattr);
+ if (k < 0 && !ERRNO_IS_NOT_SUPPORTED(k) && k != -ENODATA)
+ log_debug_errno(k,
+ "%s/%s: Failed to read 'user.extension-release.strict' extended attribute from file: %m",
+ extension_release_dir_path, de->d_name);
+ if (k < 0) {
+ log_debug("%s/%s does not have user.extension-release.strict xattr, ignoring.", extension_release_dir_path, de->d_name);
+ continue;
+ }
+
+ /* Explicitly set to request strict matching? Skip it. */
+ k = parse_boolean(extension_release_xattr);
+ if (k < 0)
+ log_debug_errno(k,
+ "%s/%s: Failed to parse 'user.extension-release.strict' extended attribute from file: %m",
+ extension_release_dir_path, de->d_name);
+ else if (k > 0)
+ log_debug("%s/%s: 'user.extension-release.strict' attribute is true, ignoring file.",
+ extension_release_dir_path, de->d_name);
+ if (k != 0)
+ continue;
+
+ log_debug("%s/%s: 'user.extension-release.strict' attribute is falseā¦",
+ extension_release_dir_path, de->d_name);
+
+ /* We already found what we were looking for, but there's another candidate?
+ * We treat this as an error, as we want to enforce that there are no ambiguities
+ * in case we are in the fallback path.*/
+ if (r == 0) {
+ r = -ENOTUNIQ;
+ break;
+ }
+
+ r = 0; /* Found it! */
+
+ if (ret_fd)
+ fd = TAKE_FD(extension_release_fd);
+
+ if (ret_path) {
+ q = path_join(extension_release_dir_path, de->d_name);
+ if (!q)
+ return -ENOMEM;
+ }
+ }
+ }
} else {
const char *p;