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Diffstat (limited to '')
| -rw-r--r-- | src/test/test-mountpoint-util.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/src/test/test-mountpoint-util.c b/src/test/test-mountpoint-util.c new file mode 100644 index 0000000..47fde5c --- /dev/null +++ b/src/test/test-mountpoint-util.c @@ -0,0 +1,316 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <sched.h> +#include <sys/mount.h> +#include <unistd.h> + +#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" + +static void test_mount_propagation_flags(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)); + } +} + +static void test_mnt_id(void) { + _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)); + } +} + +static void test_path_is_mount_point(void) { + 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; + + log_info("/* %s */", __func__); + + 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: + * + * <tmp>/file1, <tmp>/file2 + * <tmp>/link1 -> file1, <tmp>/link2 -> file2 + * <tmp>/dir1/ + * <tmp>/dir1/file + * <tmp>/dirlink1 -> dir1 + * <tmp>/dirlink1file -> dirlink1/file + * <tmp>/dir2/ + * <tmp>/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); +} + +static void test_fd_is_mount_point(void) { + _cleanup_close_ int fd = -1; + + log_info("/* %s */", __func__); + + 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 raison d'etre 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)); +} + +int main(int argc, char *argv[]) { + test_setup_logging(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); + + test_mount_propagation_flags("shared", 0, MS_SHARED); + test_mount_propagation_flags("slave", 0, MS_SLAVE); + test_mount_propagation_flags("private", 0, MS_PRIVATE); + test_mount_propagation_flags(NULL, 0, 0); + test_mount_propagation_flags("", 0, 0); + test_mount_propagation_flags("xxxx", -EINVAL, 0); + test_mount_propagation_flags(" ", -EINVAL, 0); + + test_mnt_id(); + test_path_is_mount_point(); + test_fd_is_mount_point(); + + return 0; +} |