150 lines
4.0 KiB
C
150 lines
4.0 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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#include "alloc-util.h"
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#include "env-file.h"
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#include "fd-util.h"
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#include "fileio.h"
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#include "fs-util.h"
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#include "macro.h"
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#include "os-util.h"
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#include "string-util.h"
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#include "strv.h"
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int path_is_os_tree(const char *path) {
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int r;
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assert(path);
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/* Does the path exist at all? If not, generate an error immediately. This is useful so that a missing root dir
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* always results in -ENOENT, and we can properly distinguish the case where the whole root doesn't exist from
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* the case where just the os-release file is missing. */
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if (laccess(path, F_OK) < 0)
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return -errno;
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/* We use {/etc|/usr/lib}/os-release as flag file if something is an OS */
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r = open_os_release(path, NULL, NULL);
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if (r == -ENOENT) /* We got nothing */
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return 0;
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if (r < 0)
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return r;
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return 1;
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}
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int open_os_release(const char *root, char **ret_path, int *ret_fd) {
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_cleanup_free_ char *q = NULL;
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const char *p;
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int r, fd;
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FOREACH_STRING(p, "/etc/os-release", "/usr/lib/os-release") {
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r = chase_symlinks(p, root, CHASE_PREFIX_ROOT,
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ret_path ? &q : NULL,
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ret_fd ? &fd : NULL);
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if (r != -ENOENT)
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break;
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}
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if (r < 0)
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return r;
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if (ret_fd) {
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int real_fd;
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/* Convert the O_PATH fd into a proper, readable one */
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real_fd = fd_reopen(fd, O_RDONLY|O_CLOEXEC|O_NOCTTY);
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safe_close(fd);
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if (real_fd < 0)
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return real_fd;
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*ret_fd = real_fd;
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}
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if (ret_path)
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*ret_path = TAKE_PTR(q);
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return 0;
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}
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int fopen_os_release(const char *root, char **ret_path, FILE **ret_file) {
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_cleanup_free_ char *p = NULL;
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_cleanup_close_ int fd = -1;
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FILE *f;
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int r;
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if (!ret_file)
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return open_os_release(root, ret_path, NULL);
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r = open_os_release(root, ret_path ? &p : NULL, &fd);
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if (r < 0)
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return r;
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f = take_fdopen(&fd, "r");
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if (!f)
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return -errno;
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*ret_file = f;
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if (ret_path)
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*ret_path = TAKE_PTR(p);
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return 0;
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}
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int parse_os_release(const char *root, ...) {
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_cleanup_fclose_ FILE *f = NULL;
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_cleanup_free_ char *p = NULL;
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va_list ap;
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int r;
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r = fopen_os_release(root, &p, &f);
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if (r < 0)
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return r;
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va_start(ap, root);
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r = parse_env_filev(f, p, ap);
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va_end(ap);
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return r;
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}
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int load_os_release_pairs(const char *root, char ***ret) {
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_cleanup_fclose_ FILE *f = NULL;
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_cleanup_free_ char *p = NULL;
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int r;
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r = fopen_os_release(root, &p, &f);
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if (r < 0)
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return r;
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return load_env_file_pairs(f, p, ret);
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}
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int load_os_release_pairs_with_prefix(const char *root, const char *prefix, char ***ret) {
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_cleanup_strv_free_ char **os_release_pairs = NULL, **os_release_pairs_prefixed = NULL;
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char **p, **q;
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int r;
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r = load_os_release_pairs(root, &os_release_pairs);
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if (r < 0)
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return r;
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STRV_FOREACH_PAIR(p, q, os_release_pairs) {
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char *line;
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/* We strictly return only the four main ID fields and ignore the rest */
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if (!STR_IN_SET(*p, "ID", "VERSION_ID", "BUILD_ID", "VARIANT_ID"))
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continue;
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ascii_strlower(*p);
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line = strjoin(prefix, *p, "=", *q);
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if (!line)
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return -ENOMEM;
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r = strv_consume(&os_release_pairs_prefixed, line);
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if (r < 0)
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return r;
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}
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*ret = TAKE_PTR(os_release_pairs_prefixed);
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return 0;
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}
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