a5648b8094
chase_symlinks() would return negative on error, and either a non-negative status or a non-negative fd when CHASE_OPEN was given. This made the interface quite complicated, because dependning on the flags used, we would get two different "types" of return object. Coverity was always confused by this, and flagged every use of chase_symlinks() without CHASE_OPEN as a resource leak (because it would this that an fd is returned). This patch uses a saparate output parameter, so there is no confusion. (I think it is OK to have functions which return either an error or an fd. It's only returning *either* an fd or a non-fd that is confusing.)
120 lines
3.1 KiB
C
120 lines
3.1 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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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 "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 = fdopen(fd, "r");
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if (!f)
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return -errno;
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fd = -1;
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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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