/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include "alloc-util.h" #include "def.h" #include "fd-util.h" #include "fileio.h" #include "hashmap.h" #include "log.h" #include "mountpoint-util.h" #include "path-util.h" #include "rm-rf.h" #include "string-util.h" #include "tests.h" #include "tmpfile-util.h" static void test_mount_propagation_flags_one(const char *name, int ret, unsigned long expected) { long unsigned flags; log_info("/* %s(%s) */", __func__, name); assert_se(mount_propagation_flags_from_string(name, &flags) == ret); if (ret >= 0) { const char *c; assert_se(flags == expected); c = mount_propagation_flags_to_string(flags); if (isempty(name)) assert_se(isempty(c)); else assert_se(streq(c, name)); } } TEST(mount_propagation_flags) { test_mount_propagation_flags_one("shared", 0, MS_SHARED); test_mount_propagation_flags_one("slave", 0, MS_SLAVE); test_mount_propagation_flags_one("private", 0, MS_PRIVATE); test_mount_propagation_flags_one(NULL, 0, 0); test_mount_propagation_flags_one("", 0, 0); test_mount_propagation_flags_one("xxxx", -EINVAL, 0); test_mount_propagation_flags_one(" ", -EINVAL, 0); } TEST(mnt_id) { _cleanup_fclose_ FILE *f = NULL; _cleanup_hashmap_free_free_ Hashmap *h = NULL; char *p; void *k; int r; log_info("/* %s */", __func__); assert_se(f = fopen("/proc/self/mountinfo", "re")); assert_se(h = hashmap_new(&trivial_hash_ops)); for (;;) { _cleanup_free_ char *line = NULL, *path = NULL; int mnt_id; r = read_line(f, LONG_LINE_MAX, &line); if (r == 0) break; assert_se(r > 0); assert_se(sscanf(line, "%i %*s %*s %*s %ms", &mnt_id, &path) == 2); #if HAS_FEATURE_MEMORY_SANITIZER /* We don't know the length of the string, so we need to unpoison it one char at a time */ for (const char *c = path; ;c++) { msan_unpoison(c, 1); if (!*c) break; } #endif log_debug("mountinfo: %s → %i", path, mnt_id); assert_se(hashmap_put(h, INT_TO_PTR(mnt_id), path) >= 0); path = NULL; } HASHMAP_FOREACH_KEY(p, k, h) { int mnt_id = PTR_TO_INT(k), mnt_id2; r = path_get_mnt_id(p, &mnt_id2); if (r < 0) { log_debug_errno(r, "Failed to get the mnt id of %s: %m\n", p); continue; } if (mnt_id == mnt_id2) { log_debug("mnt ids of %s is %i\n", p, mnt_id); continue; } else log_debug("mnt ids of %s are %i, %i\n", p, mnt_id, mnt_id2); /* The ids don't match? If so, then there are two mounts on the same path, let's check if * that's really the case */ char *t = hashmap_get(h, INT_TO_PTR(mnt_id2)); log_debug("the other path for mnt id %i is %s\n", mnt_id2, t); assert_se(path_equal(p, t)); } } TEST(path_is_mount_point) { int fd; char tmp_dir[] = "/tmp/test-path-is-mount-point-XXXXXX"; _cleanup_free_ char *file1 = NULL, *file2 = NULL, *link1 = NULL, *link2 = NULL; _cleanup_free_ char *dir1 = NULL, *dir1file = NULL, *dirlink1 = NULL, *dirlink1file = NULL; _cleanup_free_ char *dir2 = NULL, *dir2file = NULL; assert_se(path_is_mount_point("/", NULL, AT_SYMLINK_FOLLOW) > 0); assert_se(path_is_mount_point("/", NULL, 0) > 0); assert_se(path_is_mount_point("//", NULL, AT_SYMLINK_FOLLOW) > 0); assert_se(path_is_mount_point("//", NULL, 0) > 0); assert_se(path_is_mount_point("/proc", NULL, AT_SYMLINK_FOLLOW) > 0); assert_se(path_is_mount_point("/proc", NULL, 0) > 0); assert_se(path_is_mount_point("/proc/", NULL, AT_SYMLINK_FOLLOW) > 0); assert_se(path_is_mount_point("/proc/", NULL, 0) > 0); assert_se(path_is_mount_point("/proc/1", NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point("/proc/1", NULL, 0) == 0); assert_se(path_is_mount_point("/proc/1/", NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point("/proc/1/", NULL, 0) == 0); assert_se(path_is_mount_point("/sys", NULL, AT_SYMLINK_FOLLOW) > 0); assert_se(path_is_mount_point("/sys", NULL, 0) > 0); assert_se(path_is_mount_point("/sys/", NULL, AT_SYMLINK_FOLLOW) > 0); assert_se(path_is_mount_point("/sys/", NULL, 0) > 0); /* we'll create a hierarchy of different kinds of dir/file/link * layouts: * * /file1, /file2 * /link1 -> file1, /link2 -> file2 * /dir1/ * /dir1/file * /dirlink1 -> dir1 * /dirlink1file -> dirlink1/file * /dir2/ * /dir2/file */ /* file mountpoints */ assert_se(mkdtemp(tmp_dir) != NULL); file1 = path_join(tmp_dir, "file1"); assert_se(file1); file2 = path_join(tmp_dir, "file2"); assert_se(file2); fd = open(file1, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664); assert_se(fd > 0); close(fd); fd = open(file2, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664); assert_se(fd > 0); close(fd); link1 = path_join(tmp_dir, "link1"); assert_se(link1); assert_se(symlink("file1", link1) == 0); link2 = path_join(tmp_dir, "link2"); assert_se(link1); assert_se(symlink("file2", link2) == 0); assert_se(path_is_mount_point(file1, NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point(file1, NULL, 0) == 0); assert_se(path_is_mount_point(link1, NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point(link1, NULL, 0) == 0); /* directory mountpoints */ dir1 = path_join(tmp_dir, "dir1"); assert_se(dir1); assert_se(mkdir(dir1, 0755) == 0); dirlink1 = path_join(tmp_dir, "dirlink1"); assert_se(dirlink1); assert_se(symlink("dir1", dirlink1) == 0); dirlink1file = path_join(tmp_dir, "dirlink1file"); assert_se(dirlink1file); assert_se(symlink("dirlink1/file", dirlink1file) == 0); dir2 = path_join(tmp_dir, "dir2"); assert_se(dir2); assert_se(mkdir(dir2, 0755) == 0); assert_se(path_is_mount_point(dir1, NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point(dir1, NULL, 0) == 0); assert_se(path_is_mount_point(dirlink1, NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point(dirlink1, NULL, 0) == 0); /* file in subdirectory mountpoints */ dir1file = path_join(dir1, "file"); assert_se(dir1file); fd = open(dir1file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664); assert_se(fd > 0); close(fd); assert_se(path_is_mount_point(dir1file, NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point(dir1file, NULL, 0) == 0); assert_se(path_is_mount_point(dirlink1file, NULL, AT_SYMLINK_FOLLOW) == 0); assert_se(path_is_mount_point(dirlink1file, NULL, 0) == 0); /* these tests will only work as root */ if (mount(file1, file2, NULL, MS_BIND, NULL) >= 0) { int rf, rt, rdf, rdt, rlf, rlt, rl1f, rl1t; const char *file2d; /* files */ /* capture results in vars, to avoid dangling mounts on failure */ log_info("%s: %s", __func__, file2); rf = path_is_mount_point(file2, NULL, 0); rt = path_is_mount_point(file2, NULL, AT_SYMLINK_FOLLOW); file2d = strjoina(file2, "/"); log_info("%s: %s", __func__, file2d); rdf = path_is_mount_point(file2d, NULL, 0); rdt = path_is_mount_point(file2d, NULL, AT_SYMLINK_FOLLOW); log_info("%s: %s", __func__, link2); rlf = path_is_mount_point(link2, NULL, 0); rlt = path_is_mount_point(link2, NULL, AT_SYMLINK_FOLLOW); assert_se(umount(file2) == 0); assert_se(rf == 1); assert_se(rt == 1); assert_se(rdf == -ENOTDIR); assert_se(rdt == -ENOTDIR); assert_se(rlf == 0); assert_se(rlt == 1); /* dirs */ dir2file = path_join(dir2, "file"); assert_se(dir2file); fd = open(dir2file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664); assert_se(fd > 0); close(fd); assert_se(mount(dir2, dir1, NULL, MS_BIND, NULL) >= 0); log_info("%s: %s", __func__, dir1); rf = path_is_mount_point(dir1, NULL, 0); rt = path_is_mount_point(dir1, NULL, AT_SYMLINK_FOLLOW); log_info("%s: %s", __func__, dirlink1); rlf = path_is_mount_point(dirlink1, NULL, 0); rlt = path_is_mount_point(dirlink1, NULL, AT_SYMLINK_FOLLOW); log_info("%s: %s", __func__, dirlink1file); /* its parent is a mount point, but not /file itself */ rl1f = path_is_mount_point(dirlink1file, NULL, 0); rl1t = path_is_mount_point(dirlink1file, NULL, AT_SYMLINK_FOLLOW); assert_se(umount(dir1) == 0); assert_se(rf == 1); assert_se(rt == 1); assert_se(rlf == 0); assert_se(rlt == 1); assert_se(rl1f == 0); assert_se(rl1t == 0); } else printf("Skipping bind mount file test: %m\n"); assert_se(rm_rf(tmp_dir, REMOVE_ROOT|REMOVE_PHYSICAL) == 0); } TEST(fd_is_mount_point) { _cleanup_close_ int fd = -1; fd = open("/", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY); assert_se(fd >= 0); /* Not allowed, since "/" is a path, not a plain filename */ assert_se(fd_is_mount_point(fd, "/", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, ".", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "./", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "..", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "../", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "/proc", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "/proc/", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "proc/sys", 0) == -EINVAL); assert_se(fd_is_mount_point(fd, "proc/sys/", 0) == -EINVAL); /* This one definitely is a mount point */ assert_se(fd_is_mount_point(fd, "proc", 0) > 0); assert_se(fd_is_mount_point(fd, "proc/", 0) > 0); /* /root's entire reason for being is to be on the root file system (i.e. not in /home/ which * might be split off), so that the user can always log in, so it cannot be a mount point unless * the system is borked. Let's allow for it to be missing though. */ assert_se(IN_SET(fd_is_mount_point(fd, "root", 0), -ENOENT, 0)); assert_se(IN_SET(fd_is_mount_point(fd, "root/", 0), -ENOENT, 0)); } DEFINE_CUSTOM_TEST_MAIN( LOG_DEBUG, ({ /* let's move into our own mount namespace with all propagation from the host turned off, so * that /proc/self/mountinfo is static and constant for the whole time our test runs. */ if (unshare(CLONE_NEWNS) < 0) { if (!ERRNO_IS_PRIVILEGE(errno)) return log_error_errno(errno, "Failed to detach mount namespace: %m"); log_notice("Lacking privilege to create separate mount namespace, proceeding in originating mount namespace."); } else assert_se(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL) >= 0); }), /* no outro */);