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-rw-r--r--src/test/test-mountpoint-util.c342
1 files changed, 342 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..38a3a42
--- /dev/null
+++ b/src/test/test-mountpoint-util.c
@@ -0,0 +1,342 @@
+/* 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"
+#include "tmpfile-util.h"
+
+static void test_mount_propagation_flags_one(const char *name, int ret, unsigned long expected) {
+ unsigned long flags;
+
+ log_info("/* %s(%s) */", __func__, strnull(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;
+
+ 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;
+ const char *q;
+
+ r = path_get_mnt_id(p, &mnt_id2);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to get the mnt id of %s: %m", p);
+ continue;
+ }
+
+ if (mnt_id == mnt_id2) {
+ log_debug("mnt ids of %s is %i.", p, mnt_id);
+ continue;
+ } else
+ log_debug("mnt ids of %s are %i (from /proc/self/mountinfo), %i (from path_get_mnt_id()).", p, mnt_id, mnt_id2);
+
+ /* The ids don't match? This can easily happen e.g. running with "unshare --mount-proc".
+ * See #11505. */
+ assert_se(q = hashmap_get(h, INT_TO_PTR(mnt_id2)));
+
+ assert_se((r = path_is_mount_point(p, NULL, 0)) >= 0);
+ if (r == 0) {
+ /* If the path is not a mount point anymore, then it must be a sub directory of
+ * the path corresponds to mnt_id2. */
+ log_debug("The path %s for mnt id %i is not a mount point.", p, mnt_id2);
+ assert_se(!isempty(path_startswith(p, q)));
+ } else {
+ /* If the path is still a mount point, then it must be equivalent to the path
+ * corresponds to mnt_id2 */
+ log_debug("There are multiple mounts on the same path %s.", p);
+ assert_se(path_equal(p, q));
+ }
+ }
+}
+
+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:
+ *
+ * <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
+ log_info("Skipping bind mount file test");
+
+ assert_se(rm_rf(tmp_dir, REMOVE_ROOT|REMOVE_PHYSICAL) == 0);
+}
+
+TEST(fd_is_mount_point) {
+ _cleanup_(rm_rf_physical_and_freep) char *tmpdir = NULL;
+ _cleanup_close_ int fd = -1;
+ int r;
+
+ 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);
+
+ safe_close(fd);
+ fd = open("/tmp", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY);
+ assert_se(fd >= 0);
+
+ assert_se(mkdtemp_malloc("/tmp/not-mounted-XXXXXX", &tmpdir) >= 0);
+ assert_se(fd_is_mount_point(fd, basename(tmpdir), 0) == 0);
+ assert_se(fd_is_mount_point(fd, strjoina(basename(tmpdir), "/"), 0) == 0);
+
+ safe_close(fd);
+ fd = open("/proc", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY);
+ assert_se(fd >= 0);
+
+ assert_se(fd_is_mount_point(fd, NULL, 0) > 0);
+ assert_se(fd_is_mount_point(fd, "", 0) == -EINVAL);
+ assert_se(fd_is_mount_point(fd, "version", 0) == 0);
+
+ safe_close(fd);
+ fd = open("/proc/version", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ assert_se(fd >= 0);
+
+ r = fd_is_mount_point(fd, NULL, 0);
+ assert_se(IN_SET(r, 0, -ENOTDIR)); /* on old kernels we can't determine if regular files are mount points if we have no directory fd */
+ assert_se(fd_is_mount_point(fd, "", 0) == -EINVAL);
+}
+
+static int intro(void) {
+ /* 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);
+
+ return EXIT_SUCCESS;
+}
+
+DEFINE_TEST_MAIN_WITH_INTRO(LOG_DEBUG, intro);