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-rw-r--r--src/basic/os-util.c442
1 files changed, 442 insertions, 0 deletions
diff --git a/src/basic/os-util.c b/src/basic/os-util.c
new file mode 100644
index 0000000..dbd067f
--- /dev/null
+++ b/src/basic/os-util.c
@@ -0,0 +1,442 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "chase.h"
+#include "dirent-util.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "glyph-util.h"
+#include "macro.h"
+#include "os-util.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "stat-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "utf8.h"
+#include "xattr-util.h"
+
+static const char* const image_class_table[_IMAGE_CLASS_MAX] = {
+ [IMAGE_MACHINE] = "machine",
+ [IMAGE_PORTABLE] = "portable",
+ [IMAGE_SYSEXT] = "sysext",
+ [IMAGE_CONFEXT] = "confext",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(image_class, ImageClass);
+
+/* Helper struct for naming simplicity and reusability */
+static const struct {
+ const char *release_file_directory;
+ const char *release_file_path_prefix;
+} image_class_release_info[_IMAGE_CLASS_MAX] = {
+ [IMAGE_SYSEXT] = {
+ .release_file_directory = "/usr/lib/extension-release.d/",
+ .release_file_path_prefix = "/usr/lib/extension-release.d/extension-release.",
+ },
+ [IMAGE_CONFEXT] = {
+ .release_file_directory = "/etc/extension-release.d/",
+ .release_file_path_prefix = "/etc/extension-release.d/extension-release.",
+ }
+};
+
+bool image_name_is_valid(const char *s) {
+ if (!filename_is_valid(s))
+ return false;
+
+ if (string_has_cc(s, NULL))
+ return false;
+
+ if (!utf8_is_valid(s))
+ return false;
+
+ /* Temporary files for atomically creating new files */
+ if (startswith(s, ".#"))
+ return false;
+
+ return true;
+}
+
+int path_is_extension_tree(ImageClass image_class, const char *path, const char *extension, bool relax_extension_release_check) {
+ int r;
+
+ assert(path);
+
+ /* Does the path exist at all? If not, generate an error immediately. This is useful so that a missing root dir
+ * always results in -ENOENT, and we can properly distinguish the case where the whole root doesn't exist from
+ * the case where just the os-release file is missing. */
+ if (laccess(path, F_OK) < 0)
+ return -errno;
+
+ /* We use /usr/lib/extension-release.d/extension-release[.NAME] as flag for something being a system extension,
+ * /etc/extension-release.d/extension-release[.NAME] as flag for something being a system configuration, and finally,
+ * and {/etc|/usr/lib}/os-release as a flag for something being an OS (when not an extension). */
+ r = open_extension_release(path, image_class, extension, relax_extension_release_check, NULL, NULL);
+ if (r == -ENOENT) /* We got nothing */
+ return 0;
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static int extension_release_strict_xattr_value(int extension_release_fd, const char *extension_release_dir_path, const char *filename) {
+ int r;
+
+ assert(extension_release_fd >= 0);
+ assert(extension_release_dir_path);
+ assert(filename);
+
+ /* No xattr or cannot parse it? Then skip this. */
+ r = getxattr_at_bool(extension_release_fd, /* path= */ NULL, "user.extension-release.strict", /* flags= */ 0);
+ if (ERRNO_IS_NEG_XATTR_ABSENT(r))
+ return log_debug_errno(r, "%s/%s does not have user.extension-release.strict xattr, ignoring.",
+ extension_release_dir_path, filename);
+ if (r < 0)
+ return log_debug_errno(r, "%s/%s: Failed to read 'user.extension-release.strict' extended attribute from file, ignoring: %m",
+ extension_release_dir_path, filename);
+
+ /* Explicitly set to request strict matching? Skip it. */
+ if (r > 0) {
+ log_debug("%s/%s: 'user.extension-release.strict' attribute is true, ignoring file.",
+ extension_release_dir_path, filename);
+ return true;
+ }
+
+ log_debug("%s/%s: 'user.extension-release.strict' attribute is false%s",
+ extension_release_dir_path, filename,
+ special_glyph(SPECIAL_GLYPH_ELLIPSIS));
+
+ return false;
+}
+
+int open_os_release_at(int rfd, char **ret_path, int *ret_fd) {
+ const char *e;
+ int r;
+
+ assert(rfd >= 0 || rfd == AT_FDCWD);
+
+ e = secure_getenv("SYSTEMD_OS_RELEASE");
+ if (e)
+ return chaseat(rfd, e, CHASE_AT_RESOLVE_IN_ROOT, ret_path, ret_fd);
+
+ FOREACH_STRING(path, "/etc/os-release", "/usr/lib/os-release") {
+ r = chaseat(rfd, path, CHASE_AT_RESOLVE_IN_ROOT, ret_path, ret_fd);
+ if (r != -ENOENT)
+ return r;
+ }
+
+ return -ENOENT;
+}
+
+int open_os_release(const char *root, char **ret_path, int *ret_fd) {
+ _cleanup_close_ int rfd = -EBADF, fd = -EBADF;
+ _cleanup_free_ char *p = NULL;
+ int r;
+
+ rfd = open(empty_to_root(root), O_CLOEXEC | O_DIRECTORY | O_PATH);
+ if (rfd < 0)
+ return -errno;
+
+ r = open_os_release_at(rfd, ret_path ? &p : NULL, ret_fd ? &fd : NULL);
+ if (r < 0)
+ return r;
+
+ if (ret_path) {
+ r = chaseat_prefix_root(p, root, ret_path);
+ if (r < 0)
+ return r;
+ }
+
+ if (ret_fd)
+ *ret_fd = TAKE_FD(fd);
+
+ return 0;
+}
+
+int open_extension_release_at(
+ int rfd,
+ ImageClass image_class,
+ const char *extension,
+ bool relax_extension_release_check,
+ char **ret_path,
+ int *ret_fd) {
+
+ _cleanup_free_ char *dir_path = NULL, *path_found = NULL;
+ _cleanup_close_ int fd_found = -EBADF;
+ _cleanup_closedir_ DIR *dir = NULL;
+ bool found = false;
+ const char *p;
+ int r;
+
+ assert(rfd >= 0 || rfd == AT_FDCWD);
+ assert(!extension || (image_class >= 0 && image_class < _IMAGE_CLASS_MAX));
+
+ if (!extension)
+ return open_os_release_at(rfd, ret_path, ret_fd);
+
+ if (!IN_SET(image_class, IMAGE_SYSEXT, IMAGE_CONFEXT))
+ return -EINVAL;
+
+ if (!image_name_is_valid(extension))
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "The extension name %s is invalid.", extension);
+
+ p = strjoina(image_class_release_info[image_class].release_file_path_prefix, extension);
+ r = chaseat(rfd, p, CHASE_AT_RESOLVE_IN_ROOT, ret_path, ret_fd);
+ log_full_errno_zerook(LOG_DEBUG, MIN(r, 0), "Checking for %s: %m", p);
+ if (r != -ENOENT)
+ return r;
+
+ /* 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. */
+
+ p = image_class_release_info[image_class].release_file_directory;
+ r = chase_and_opendirat(rfd, p, CHASE_AT_RESOLVE_IN_ROOT, &dir_path, &dir);
+ if (r < 0)
+ return log_debug_errno(r, "Cannot open %s, ignoring: %m", p);
+
+ FOREACH_DIRENT(de, dir, return -errno) {
+ _cleanup_close_ int fd = -EBADF;
+ const char *image_name;
+
+ if (!IN_SET(de->d_type, DT_REG, DT_UNKNOWN))
+ continue;
+
+ 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 release file name, ignoring.", 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. */
+ fd = openat(dirfd(dir), de->d_name, O_PATH|O_CLOEXEC|O_NOFOLLOW);
+ if (fd < 0)
+ return log_debug_errno(errno, "Failed to open release file %s/%s: %m", dir_path, de->d_name);
+
+ /* Really ensure it is a regular file after we open it. */
+ r = fd_verify_regular(fd);
+ if (r < 0) {
+ log_debug_errno(r, "%s/%s is not a regular file, ignoring: %m", dir_path, de->d_name);
+ continue;
+ }
+
+ if (!relax_extension_release_check &&
+ extension_release_strict_xattr_value(fd, dir_path, de->d_name) != 0)
+ continue;
+
+ /* 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 (found)
+ return -ENOTUNIQ;
+
+ found = true;
+
+ if (ret_fd)
+ fd_found = TAKE_FD(fd);
+
+ if (ret_path) {
+ path_found = path_join(dir_path, de->d_name);
+ if (!path_found)
+ return -ENOMEM;
+ }
+ }
+ if (!found)
+ return -ENOENT;
+
+ if (ret_fd)
+ *ret_fd = TAKE_FD(fd_found);
+ if (ret_path)
+ *ret_path = TAKE_PTR(path_found);
+
+ return 0;
+}
+
+int open_extension_release(
+ const char *root,
+ ImageClass image_class,
+ const char *extension,
+ bool relax_extension_release_check,
+ char **ret_path,
+ int *ret_fd) {
+
+ _cleanup_close_ int rfd = -EBADF, fd = -EBADF;
+ _cleanup_free_ char *p = NULL;
+ int r;
+
+ rfd = open(empty_to_root(root), O_CLOEXEC | O_DIRECTORY | O_PATH);
+ if (rfd < 0)
+ return -errno;
+
+ r = open_extension_release_at(rfd, image_class, extension, relax_extension_release_check,
+ ret_path ? &p : NULL, ret_fd ? &fd : NULL);
+ if (r < 0)
+ return r;
+
+ if (ret_path) {
+ r = chaseat_prefix_root(p, root, ret_path);
+ if (r < 0)
+ return r;
+ }
+
+ if (ret_fd)
+ *ret_fd = TAKE_FD(fd);
+
+ return 0;
+}
+
+static int parse_extension_release_atv(
+ int rfd,
+ ImageClass image_class,
+ const char *extension,
+ bool relax_extension_release_check,
+ va_list ap) {
+
+ _cleanup_close_ int fd = -EBADF;
+ _cleanup_free_ char *p = NULL;
+ int r;
+
+ assert(rfd >= 0 || rfd == AT_FDCWD);
+
+ r = open_extension_release_at(rfd, image_class, extension, relax_extension_release_check, &p, &fd);
+ if (r < 0)
+ return r;
+
+ return parse_env_file_fdv(fd, p, ap);
+}
+
+int parse_extension_release_at_sentinel(
+ int rfd,
+ ImageClass image_class,
+ bool relax_extension_release_check,
+ const char *extension,
+ ...) {
+
+ va_list ap;
+ int r;
+
+ assert(rfd >= 0 || rfd == AT_FDCWD);
+
+ va_start(ap, extension);
+ r = parse_extension_release_atv(rfd, image_class, extension, relax_extension_release_check, ap);
+ va_end(ap);
+ return r;
+}
+
+int parse_extension_release_sentinel(
+ const char *root,
+ ImageClass image_class,
+ bool relax_extension_release_check,
+ const char *extension,
+ ...) {
+
+ _cleanup_close_ int rfd = -EBADF;
+ va_list ap;
+ int r;
+
+ rfd = open(empty_to_root(root), O_CLOEXEC | O_DIRECTORY | O_PATH);
+ if (rfd < 0)
+ return -errno;
+
+ va_start(ap, extension);
+ r = parse_extension_release_atv(rfd, image_class, extension, relax_extension_release_check, ap);
+ va_end(ap);
+ return r;
+}
+
+int load_os_release_pairs_with_prefix(const char *root, const char *prefix, char ***ret) {
+ _cleanup_strv_free_ char **os_release_pairs = NULL, **os_release_pairs_prefixed = NULL;
+ int r;
+
+ r = load_os_release_pairs(root, &os_release_pairs);
+ if (r < 0)
+ return r;
+
+ STRV_FOREACH_PAIR(p, q, os_release_pairs) {
+ char *line;
+
+ /* We strictly return only the four main ID fields and ignore the rest */
+ if (!STR_IN_SET(*p, "ID", "VERSION_ID", "BUILD_ID", "VARIANT_ID"))
+ continue;
+
+ ascii_strlower(*p);
+ line = strjoin(prefix, *p, "=", *q);
+ if (!line)
+ return -ENOMEM;
+ r = strv_consume(&os_release_pairs_prefixed, line);
+ if (r < 0)
+ return r;
+ }
+
+ *ret = TAKE_PTR(os_release_pairs_prefixed);
+
+ return 0;
+}
+
+int load_extension_release_pairs(const char *root, ImageClass image_class, const char *extension, bool relax_extension_release_check, char ***ret) {
+ _cleanup_close_ int fd = -EBADF;
+ _cleanup_free_ char *p = NULL;
+ int r;
+
+ r = open_extension_release(root, image_class, extension, relax_extension_release_check, &p, &fd);
+ if (r < 0)
+ return r;
+
+ return load_env_file_pairs_fd(fd, p, ret);
+}
+
+int os_release_support_ended(const char *support_end, bool quiet, usec_t *ret_eol) {
+ _cleanup_free_ char *_support_end_alloc = NULL;
+ int r;
+
+ if (!support_end) {
+ /* If the caller has the variably handy, they can pass it in. If not, we'll read it
+ * ourselves. */
+
+ r = parse_os_release(NULL,
+ "SUPPORT_END", &_support_end_alloc);
+ if (r < 0 && r != -ENOENT)
+ return log_full_errno(quiet ? LOG_DEBUG : LOG_WARNING, r,
+ "Failed to read os-release file, ignoring: %m");
+
+ support_end = _support_end_alloc;
+ }
+
+ if (isempty(support_end)) /* An empty string is a explicit way to say "no EOL exists" */
+ return false; /* no end date defined */
+
+ struct tm tm = {};
+ const char *k = strptime(support_end, "%Y-%m-%d", &tm);
+ if (!k || *k)
+ return log_full_errno(quiet ? LOG_DEBUG : LOG_WARNING, SYNTHETIC_ERRNO(EINVAL),
+ "Failed to parse SUPPORT_END= in os-release file, ignoring: %m");
+
+ time_t eol = timegm(&tm);
+ if (eol == (time_t) -1)
+ return log_full_errno(quiet ? LOG_DEBUG : LOG_WARNING, SYNTHETIC_ERRNO(EINVAL),
+ "Failed to convert SUPPORT_END= in os-release file, ignoring: %m");
+
+ if (ret_eol)
+ *ret_eol = eol * USEC_PER_SEC;
+
+ return DIV_ROUND_UP(now(CLOCK_REALTIME), USEC_PER_SEC) > (usec_t) eol;
+}
+
+const char *os_release_pretty_name(const char *pretty_name, const char *name) {
+ /* Distills a "pretty" name to show from os-release data. First argument is supposed to be the
+ * PRETTY_NAME= field, the second one the NAME= field. This function is trivial, of course, and
+ * exists mostly to ensure we use the same logic wherever possible. */
+
+ return empty_to_null(pretty_name) ?:
+ empty_to_null(name) ?: "Linux";
+}