diff options
Diffstat (limited to 'src/basic/os-util.c')
| -rw-r--r-- | src/basic/os-util.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/src/basic/os-util.c b/src/basic/os-util.c new file mode 100644 index 0000000..8f8bb08 --- /dev/null +++ b/src/basic/os-util.c @@ -0,0 +1,372 @@ +/* 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 "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-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)) + 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(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, + * and {/etc|/usr/lib}/os-release as a flag for something being an OS (when not an extension). */ + r = open_extension_release(path, 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. */ + _cleanup_free_ char *extension_release_xattr = NULL; + r = fgetxattr_malloc(extension_release_fd, "user.extension-release.strict", &extension_release_xattr); + if (r < 0) { + if (!ERRNO_IS_XATTR_ABSENT(r)) + 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); + + return log_debug_errno(r, "%s/%s does not have user.extension-release.strict xattr, ignoring.", extension_release_dir_path, filename); + } + + /* Explicitly set to request strict matching? Skip it. */ + r = parse_boolean(extension_release_xattr); + if (r < 0) + return log_debug_errno(r, + "%s/%s: Failed to parse 'user.extension-release.strict' extended attribute from file, ignoring: %m", + extension_release_dir_path, filename); + 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_extension_release(const char *root, const char *extension, bool relax_extension_release_check, char **ret_path, int *ret_fd) { + _cleanup_free_ char *q = NULL; + int r, fd; + + if (extension) { + const char *extension_full_path; + + if (!image_name_is_valid(extension)) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), + "The extension name %s is invalid.", extension); + + extension_full_path = strjoina("/usr/lib/extension-release.d/extension-release.", extension); + 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; + } + + if (!relax_extension_release_check) { + k = extension_release_strict_xattr_value(extension_release_fd, + extension_release_dir_path, + de->d_name); + if (k != 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 (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 *var = secure_getenv("SYSTEMD_OS_RELEASE"); + if (var) + r = chase_symlinks(var, root, 0, + ret_path ? &q : NULL, + ret_fd ? &fd : NULL); + else + FOREACH_STRING(path, "/etc/os-release", "/usr/lib/os-release") { + r = chase_symlinks(path, root, CHASE_PREFIX_ROOT, + ret_path ? &q : NULL, + ret_fd ? &fd : NULL); + if (r != -ENOENT) + break; + } + } + if (r < 0) + return r; + + if (ret_fd) { + int real_fd; + + /* Convert the O_PATH fd into a proper, readable one */ + real_fd = fd_reopen(fd, O_RDONLY|O_CLOEXEC|O_NOCTTY); + safe_close(fd); + if (real_fd < 0) + return real_fd; + + *ret_fd = real_fd; + } + + if (ret_path) + *ret_path = TAKE_PTR(q); + + return 0; +} + +int fopen_extension_release(const char *root, const char *extension, bool relax_extension_release_check, char **ret_path, FILE **ret_file) { + _cleanup_free_ char *p = NULL; + _cleanup_close_ int fd = -1; + FILE *f; + int r; + + if (!ret_file) + return open_extension_release(root, extension, relax_extension_release_check, ret_path, NULL); + + r = open_extension_release(root, extension, relax_extension_release_check, ret_path ? &p : NULL, &fd); + if (r < 0) + return r; + + f = take_fdopen(&fd, "r"); + if (!f) + return -errno; + + if (ret_path) + *ret_path = TAKE_PTR(p); + *ret_file = f; + + return 0; +} + +static int parse_release_internal(const char *root, bool relax_extension_release_check, const char *extension, va_list ap) { + _cleanup_fclose_ FILE *f = NULL; + _cleanup_free_ char *p = NULL; + int r; + + r = fopen_extension_release(root, extension, relax_extension_release_check, &p, &f); + if (r < 0) + return r; + + return parse_env_filev(f, p, ap); +} + +int _parse_extension_release(const char *root, bool relax_extension_release_check, const char *extension, ...) { + va_list ap; + int r; + + va_start(ap, extension); + r = parse_release_internal(root, relax_extension_release_check, extension, ap); + va_end(ap); + + return r; +} + +int _parse_os_release(const char *root, ...) { + va_list ap; + int r; + + va_start(ap, root); + r = parse_release_internal(root, /* relax_extension_release_check= */ false, NULL, ap); + va_end(ap); + + return r; +} + +int load_os_release_pairs(const char *root, char ***ret) { + _cleanup_fclose_ FILE *f = NULL; + _cleanup_free_ char *p = NULL; + int r; + + r = fopen_os_release(root, &p, &f); + if (r < 0) + return r; + + return load_env_file_pairs(f, p, ret); +} + +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, const char *extension, bool relax_extension_release_check, char ***ret) { + _cleanup_fclose_ FILE *f = NULL; + _cleanup_free_ char *p = NULL; + int r; + + r = fopen_extension_release(root, extension, relax_extension_release_check, &p, &f); + if (r < 0) + return r; + + return load_env_file_pairs(f, p, ret); +} + +int os_release_support_ended(const char *support_end, bool quiet) { + _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) + return log_full_errno((r == -ENOENT || quiet) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to read os-release file, ignoring: %m"); + if (!_support_end_alloc) + return false; /* no end date defined */ + + support_end = _support_end_alloc; + } + + 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 = mktime(&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"); + + usec_t ts = now(CLOCK_REALTIME); + return DIV_ROUND_UP(ts, USEC_PER_SEC) > (usec_t) eol; +} |