src/test/test-mountpoint-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <sched.h>
   4 #include <sys/mount.h>
   5 #include <unistd.h>
   6
   7 #include "alloc-util.h"
   8 #include "constants.h"
   9 #include "fd-util.h"
  10 #include "fileio.h"
  11 #include "hashmap.h"
  12 #include "log.h"
  13 #include "mountpoint-util.h"
  14 #include "path-util.h"
  15 #include "rm-rf.h"
  16 #include "string-util.h"
  17 #include "tests.h"
  18 #include "tmpfile-util.h"
  19
  20 static void test_mount_propagation_flag_one(const char *name, int ret, unsigned long expected) {
  21         unsigned long flags;
  22
  23         log_info("/* %s(%s) */", __func__, strnull(name));
  24
  25         assert_se(mount_propagation_flag_from_string(name, &flags) == ret);
  26
  27         if (ret >= 0) {
  28                 const char *c;
  29
  30                 assert_se(flags == expected);
  31
  32                 c = mount_propagation_flag_to_string(flags);
  33                 if (isempty(name))
  34                         assert_se(isempty(c));
  35                 else
  36                         ASSERT_STREQ(c, name);
  37         }
  38 }
  39
  40 TEST(mount_propagation_flag) {
  41         test_mount_propagation_flag_one("shared", 0, MS_SHARED);
  42         test_mount_propagation_flag_one("slave", 0, MS_SLAVE);
  43         test_mount_propagation_flag_one("private", 0, MS_PRIVATE);
  44         test_mount_propagation_flag_one(NULL, 0, 0);
  45         test_mount_propagation_flag_one("", 0, 0);
  46         test_mount_propagation_flag_one("xxxx", -EINVAL, 0);
  47         test_mount_propagation_flag_one(" ", -EINVAL, 0);
  48 }
  49
  50 TEST(mnt_id) {
  51         _cleanup_fclose_ FILE *f = NULL;
  52         _cleanup_hashmap_free_free_ Hashmap *h = NULL;
  53         char *p;
  54         void *k;
  55         int r;
  56
  57         assert_se(f = fopen("/proc/self/mountinfo", "re"));
  58         assert_se(h = hashmap_new(&trivial_hash_ops));
  59
  60         for (;;) {
  61                 _cleanup_free_ char *line = NULL, *path = NULL;
  62                 int mnt_id;
  63
  64                 r = read_line(f, LONG_LINE_MAX, &line);
  65                 if (r == 0)
  66                         break;
  67                 assert_se(r > 0);
  68
  69                 assert_se(sscanf(line, "%i %*s %*s %*s %ms", &mnt_id, &path) == 2);
  70 #if HAS_FEATURE_MEMORY_SANITIZER
  71                 /* We don't know the length of the string, so we need to unpoison it one char at a time */
  72                 for (const char *c = path; ; c++) {
  73                         msan_unpoison(c, 1);
  74                         if (!*c)
  75                                 break;
  76                 }
  77 #endif
  78                 log_debug("mountinfo: %s → %i", path, mnt_id);
  79
  80                 assert_se(hashmap_put(h, INT_TO_PTR(mnt_id), path) >= 0);
  81                 path = NULL;
  82         }
  83
  84         HASHMAP_FOREACH_KEY(p, k, h) {
  85                 int mnt_id = PTR_TO_INT(k), mnt_id2;
  86                 const char *q;
  87
  88                 r = path_get_mnt_id(p, &mnt_id2);
  89                 if (r < 0) {
  90                         log_debug_errno(r, "Failed to get the mnt id of %s: %m", p);
  91                         continue;
  92                 }
  93
  94                 if (mnt_id == mnt_id2) {
  95                         log_debug("mnt ids of %s is %i.", p, mnt_id);
  96                         continue;
  97                 } else
  98                         log_debug("mnt ids of %s are %i (from /proc/self/mountinfo), %i (from path_get_mnt_id()).", p, mnt_id, mnt_id2);
  99
 100                 /* The ids don't match? This can easily happen e.g. running with "unshare --mount-proc".
 101                  * See #11505. */
 102                 assert_se(q = hashmap_get(h, INT_TO_PTR(mnt_id2)));
 103
 104                 assert_se((r = path_is_mount_point_full(p, NULL, 0)) >= 0);
 105                 if (r == 0) {
 106                         /* If the path is not a mount point anymore, then it must be a sub directory of
 107                          * the path corresponds to mnt_id2. */
 108                         log_debug("The path %s for mnt id %i is not a mount point.", p, mnt_id2);
 109                         assert_se(!isempty(path_startswith(p, q)));
 110                 } else {
 111                         /* If the path is still a mount point, then it must be equivalent to the path
 112                          * corresponds to mnt_id2 */
 113                         log_debug("There are multiple mounts on the same path %s.", p);
 114                         assert_se(path_equal(p, q));
 115                 }
 116         }
 117 }
 118
 119 TEST(path_is_mount_point) {
 120         int fd;
 121         char tmp_dir[] = "/tmp/test-path-is-mount-point-XXXXXX";
 122         _cleanup_free_ char *file1 = NULL, *file2 = NULL, *link1 = NULL, *link2 = NULL;
 123         _cleanup_free_ char *dir1 = NULL, *dir1file = NULL, *dirlink1 = NULL, *dirlink1file = NULL;
 124         _cleanup_free_ char *dir2 = NULL, *dir2file = NULL;
 125
 126         assert_se(path_is_mount_point_full("/", NULL, AT_SYMLINK_FOLLOW) > 0);
 127         assert_se(path_is_mount_point_full("/", NULL, 0) > 0);
 128         assert_se(path_is_mount_point_full("//", NULL, AT_SYMLINK_FOLLOW) > 0);
 129         assert_se(path_is_mount_point_full("//", NULL, 0) > 0);
 130
 131         assert_se(path_is_mount_point_full("/proc", NULL, AT_SYMLINK_FOLLOW) > 0);
 132         assert_se(path_is_mount_point_full("/proc", NULL, 0) > 0);
 133         assert_se(path_is_mount_point_full("/proc/", NULL, AT_SYMLINK_FOLLOW) > 0);
 134         assert_se(path_is_mount_point_full("/proc/", NULL, 0) > 0);
 135
 136         assert_se(path_is_mount_point_full("/proc/1", NULL, AT_SYMLINK_FOLLOW) == 0);
 137         assert_se(path_is_mount_point_full("/proc/1", NULL, 0) == 0);
 138         assert_se(path_is_mount_point_full("/proc/1/", NULL, AT_SYMLINK_FOLLOW) == 0);
 139         assert_se(path_is_mount_point_full("/proc/1/", NULL, 0) == 0);
 140
 141         /* we'll create a hierarchy of different kinds of dir/file/link
 142          * layouts:
 143          *
 144          * <tmp>/file1, <tmp>/file2
 145          * <tmp>/link1 -> file1, <tmp>/link2 -> file2
 146          * <tmp>/dir1/
 147          * <tmp>/dir1/file
 148          * <tmp>/dirlink1 -> dir1
 149          * <tmp>/dirlink1file -> dirlink1/file
 150          * <tmp>/dir2/
 151          * <tmp>/dir2/file
 152          */
 153
 154         /* file mountpoints */
 155         ASSERT_NOT_NULL(mkdtemp(tmp_dir));
 156         file1 = path_join(tmp_dir, "file1");
 157         assert_se(file1);
 158         file2 = path_join(tmp_dir, "file2");
 159         assert_se(file2);
 160         fd = open(file1, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 161         assert_se(fd > 0);
 162         close(fd);
 163         fd = open(file2, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 164         assert_se(fd > 0);
 165         close(fd);
 166         link1 = path_join(tmp_dir, "link1");
 167         assert_se(link1);
 168         assert_se(symlink("file1", link1) == 0);
 169         link2 = path_join(tmp_dir, "link2");
 170         assert_se(link1);
 171         assert_se(symlink("file2", link2) == 0);
 172
 173         assert_se(path_is_mount_point_full(file1, NULL, AT_SYMLINK_FOLLOW) == 0);
 174         assert_se(path_is_mount_point_full(file1, NULL, 0) == 0);
 175         assert_se(path_is_mount_point_full(link1, NULL, AT_SYMLINK_FOLLOW) == 0);
 176         assert_se(path_is_mount_point_full(link1, NULL, 0) == 0);
 177
 178         /* directory mountpoints */
 179         dir1 = path_join(tmp_dir, "dir1");
 180         assert_se(dir1);
 181         assert_se(mkdir(dir1, 0755) == 0);
 182         dirlink1 = path_join(tmp_dir, "dirlink1");
 183         assert_se(dirlink1);
 184         assert_se(symlink("dir1", dirlink1) == 0);
 185         dirlink1file = path_join(tmp_dir, "dirlink1file");
 186         assert_se(dirlink1file);
 187         assert_se(symlink("dirlink1/file", dirlink1file) == 0);
 188         dir2 = path_join(tmp_dir, "dir2");
 189         assert_se(dir2);
 190         assert_se(mkdir(dir2, 0755) == 0);
 191
 192         assert_se(path_is_mount_point_full(dir1, NULL, AT_SYMLINK_FOLLOW) == 0);
 193         assert_se(path_is_mount_point_full(dir1, NULL, 0) == 0);
 194         assert_se(path_is_mount_point_full(dirlink1, NULL, AT_SYMLINK_FOLLOW) == 0);
 195         assert_se(path_is_mount_point_full(dirlink1, NULL, 0) == 0);
 196
 197         /* file in subdirectory mountpoints */
 198         dir1file = path_join(dir1, "file");
 199         assert_se(dir1file);
 200         fd = open(dir1file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 201         assert_se(fd > 0);
 202         close(fd);
 203
 204         assert_se(path_is_mount_point_full(dir1file, NULL, AT_SYMLINK_FOLLOW) == 0);
 205         assert_se(path_is_mount_point_full(dir1file, NULL, 0) == 0);
 206         assert_se(path_is_mount_point_full(dirlink1file, NULL, AT_SYMLINK_FOLLOW) == 0);
 207         assert_se(path_is_mount_point_full(dirlink1file, NULL, 0) == 0);
 208
 209         /* these tests will only work as root */
 210         if (mount(file1, file2, NULL, MS_BIND, NULL) >= 0) {
 211                 int rf, rt, rdf, rdt, rlf, rlt, rl1f, rl1t;
 212                 const char *file2d;
 213
 214                 /* files */
 215                 /* capture results in vars, to avoid dangling mounts on failure */
 216                 log_info("%s: %s", __func__, file2);
 217                 rf = path_is_mount_point_full(file2, NULL, 0);
 218                 rt = path_is_mount_point_full(file2, NULL, AT_SYMLINK_FOLLOW);
 219
 220                 file2d = strjoina(file2, "/");
 221                 log_info("%s: %s", __func__, file2d);
 222                 rdf = path_is_mount_point_full(file2d, NULL, 0);
 223                 rdt = path_is_mount_point_full(file2d, NULL, AT_SYMLINK_FOLLOW);
 224
 225                 log_info("%s: %s", __func__, link2);
 226                 rlf = path_is_mount_point_full(link2, NULL, 0);
 227                 rlt = path_is_mount_point_full(link2, NULL, AT_SYMLINK_FOLLOW);
 228
 229                 assert_se(umount(file2) == 0);
 230
 231                 assert_se(rf == 1);
 232                 assert_se(rt == 1);
 233                 assert_se(rdf == -ENOTDIR);
 234                 assert_se(rdt == -ENOTDIR);
 235                 assert_se(rlf == 0);
 236                 assert_se(rlt == 1);
 237
 238                 /* dirs */
 239                 dir2file = path_join(dir2, "file");
 240                 assert_se(dir2file);
 241                 fd = open(dir2file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 242                 assert_se(fd > 0);
 243                 close(fd);
 244
 245                 assert_se(mount(dir2, dir1, NULL, MS_BIND, NULL) >= 0);
 246
 247                 log_info("%s: %s", __func__, dir1);
 248                 rf = path_is_mount_point_full(dir1, NULL, 0);
 249                 rt = path_is_mount_point_full(dir1, NULL, AT_SYMLINK_FOLLOW);
 250                 log_info("%s: %s", __func__, dirlink1);
 251                 rlf = path_is_mount_point_full(dirlink1, NULL, 0);
 252                 rlt = path_is_mount_point_full(dirlink1, NULL, AT_SYMLINK_FOLLOW);
 253                 log_info("%s: %s", __func__, dirlink1file);
 254                 /* its parent is a mount point, but not /file itself */
 255                 rl1f = path_is_mount_point_full(dirlink1file, NULL, 0);
 256                 rl1t = path_is_mount_point_full(dirlink1file, NULL, AT_SYMLINK_FOLLOW);
 257
 258                 assert_se(umount(dir1) == 0);
 259
 260                 assert_se(rf == 1);
 261                 assert_se(rt == 1);
 262                 assert_se(rlf == 0);
 263                 assert_se(rlt == 1);
 264                 assert_se(rl1f == 0);
 265                 assert_se(rl1t == 0);
 266
 267         } else
 268                 log_info("Skipping bind mount file test");
 269
 270         assert_se(rm_rf(tmp_dir, REMOVE_ROOT|REMOVE_PHYSICAL) == 0);
 271 }
 272
 273 TEST(fd_is_mount_point) {
 274         _cleanup_(rm_rf_physical_and_freep) char *tmpdir = NULL;
 275         _cleanup_close_ int fd = -EBADF;
 276         int r;
 277
 278         fd = open("/", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY);
 279         assert_se(fd >= 0);
 280
 281         /* Not allowed, since "/" is a path, not a plain filename */
 282         assert_se(fd_is_mount_point(fd, "/", 0) == -EINVAL);
 283         assert_se(fd_is_mount_point(fd, ".", 0) == -EINVAL);
 284         assert_se(fd_is_mount_point(fd, "./", 0) == -EINVAL);
 285         assert_se(fd_is_mount_point(fd, "..", 0) == -EINVAL);
 286         assert_se(fd_is_mount_point(fd, "../", 0) == -EINVAL);
 287         assert_se(fd_is_mount_point(fd, "", 0) == -EINVAL);
 288         assert_se(fd_is_mount_point(fd, "/proc", 0) == -EINVAL);
 289         assert_se(fd_is_mount_point(fd, "/proc/", 0) == -EINVAL);
 290         assert_se(fd_is_mount_point(fd, "proc/sys", 0) == -EINVAL);
 291         assert_se(fd_is_mount_point(fd, "proc/sys/", 0) == -EINVAL);
 292
 293         /* This one definitely is a mount point */
 294         assert_se(fd_is_mount_point(fd, "proc", 0) > 0);
 295         assert_se(fd_is_mount_point(fd, "proc/", 0) > 0);
 296
 297         safe_close(fd);
 298         fd = open("/tmp", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY);
 299         assert_se(fd >= 0);
 300
 301         assert_se(mkdtemp_malloc("/tmp/not-mounted-XXXXXX", &tmpdir) >= 0);
 302         assert_se(fd_is_mount_point(fd, basename(tmpdir), 0) == 0);
 303         assert_se(fd_is_mount_point(fd, strjoina(basename(tmpdir), "/"), 0) == 0);
 304
 305         safe_close(fd);
 306         fd = open("/proc", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY);
 307         assert_se(fd >= 0);
 308
 309         assert_se(fd_is_mount_point(fd, NULL, 0) > 0);
 310         assert_se(fd_is_mount_point(fd, "", 0) == -EINVAL);
 311         assert_se(fd_is_mount_point(fd, "version", 0) == 0);
 312
 313         safe_close(fd);
 314         fd = open("/proc/version", O_RDONLY|O_CLOEXEC|O_NOCTTY);
 315         assert_se(fd >= 0);
 316
 317         r = fd_is_mount_point(fd, NULL, 0);
 318         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 */
 319         assert_se(fd_is_mount_point(fd, "", 0) == -EINVAL);
 320 }
 321
 322 TEST(ms_nosymfollow_supported) {
 323         log_info("MS_NOSYMFOLLOW supported: %s", yes_no(ms_nosymfollow_supported()));
 324 }
 325
 326 TEST(mount_option_supported) {
 327         int r;
 328
 329         r = mount_option_supported("tmpfs", "size", "64M");
 330         log_info("tmpfs supports size=64M: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 331         assert_se(r > 0 || r == -EAGAIN || ERRNO_IS_NEG_PRIVILEGE(r));
 332
 333         r = mount_option_supported("ext4", "discard", NULL);
 334         log_info("ext4 supports discard: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 335         assert_se(r > 0 || r == -EAGAIN || ERRNO_IS_NEG_PRIVILEGE(r));
 336
 337         r = mount_option_supported("tmpfs", "idontexist", "64M");
 338         log_info("tmpfs supports idontexist: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 339         assert_se(IN_SET(r, 0, -EAGAIN) || ERRNO_IS_NEG_PRIVILEGE(r));
 340
 341         r = mount_option_supported("tmpfs", "ialsodontexist", NULL);
 342         log_info("tmpfs supports ialsodontexist: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 343         assert_se(IN_SET(r, 0, -EAGAIN) || ERRNO_IS_NEG_PRIVILEGE(r));
 344
 345         r = mount_option_supported("proc", "hidepid", "1");
 346         log_info("proc supports hidepid=1: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 347         assert_se(r >= 0 || r == -EAGAIN || ERRNO_IS_NEG_PRIVILEGE(r));
 348 }
 349
 350 TEST(fstype_can_discard) {
 351         assert_se(fstype_can_discard("ext4"));
 352         assert_se(!fstype_can_discard("squashfs"));
 353         assert_se(!fstype_can_discard("iso9660"));
 354 }
 355
 356 TEST(fstype_can_norecovery) {
 357         assert_se(fstype_can_norecovery("ext4"));
 358         assert_se(!fstype_can_norecovery("vfat"));
 359         assert_se(!fstype_can_norecovery("tmpfs"));
 360 }
 361
 362 TEST(fstype_can_umask) {
 363         assert_se(fstype_can_umask("vfat"));
 364         assert_se(!fstype_can_umask("tmpfs"));
 365 }
 366
 367 TEST(path_get_mnt_id_at_null) {
 368         _cleanup_close_ int root_fd = -EBADF, run_fd = -EBADF;
 369         int id1, id2;
 370
 371         assert_se(path_get_mnt_id_at(AT_FDCWD, "/run/", &id1) >= 0);
 372         assert_se(id1 > 0);
 373
 374         assert_se(path_get_mnt_id_at(AT_FDCWD, "/run", &id2) >= 0);
 375         assert_se(id1 == id2);
 376         id2 = -1;
 377
 378         root_fd = open("/", O_DIRECTORY|O_CLOEXEC);
 379         assert_se(root_fd >= 0);
 380
 381         assert_se(path_get_mnt_id_at(root_fd, "/run/", &id2) >= 0);
 382         assert_se(id1 = id2);
 383         id2 = -1;
 384
 385         assert_se(path_get_mnt_id_at(root_fd, "/run", &id2) >= 0);
 386         assert_se(id1 = id2);
 387         id2 = -1;
 388
 389         assert_se(path_get_mnt_id_at(root_fd, "run", &id2) >= 0);
 390         assert_se(id1 = id2);
 391         id2 = -1;
 392
 393         assert_se(path_get_mnt_id_at(root_fd, "run/", &id2) >= 0);
 394         assert_se(id1 = id2);
 395         id2 = -1;
 396
 397         run_fd = openat(root_fd, "run", O_DIRECTORY|O_CLOEXEC);
 398         assert_se(run_fd >= 0);
 399
 400         id2 = -1;
 401         assert_se(path_get_mnt_id_at(run_fd, "", &id2) >= 0);
 402         assert_se(id1 = id2);
 403         id2 = -1;
 404
 405         assert_se(path_get_mnt_id_at(run_fd, NULL, &id2) >= 0);
 406         assert_se(id1 = id2);
 407         id2 = -1;
 408
 409         assert_se(path_get_mnt_id_at(run_fd, ".", &id2) >= 0);
 410         assert_se(id1 = id2);
 411         id2 = -1;
 412 }
 413
 414 static int intro(void) {
 415         /* let's move into our own mount namespace with all propagation from the host turned off, so
 416          * that /proc/self/mountinfo is static and constant for the whole time our test runs. */
 417
 418         if (unshare(CLONE_NEWNS) < 0) {
 419                 if (!ERRNO_IS_PRIVILEGE(errno))
 420                         return log_error_errno(errno, "Failed to detach mount namespace: %m");
 421
 422                 log_notice("Lacking privilege to create separate mount namespace, proceeding in originating mount namespace.");
 423         } else
 424                 assert_se(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL) >= 0);
 425
 426         return EXIT_SUCCESS;
 427 }
 428
 429 DEFINE_TEST_MAIN_WITH_INTRO(LOG_DEBUG, intro);