src/test/test-mountpoint-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <sched.h>
   4 #include <stdlib.h>
   5 #include <sys/mount.h>
   6 #include <unistd.h>
   7
   8 #include "alloc-util.h"
   9 #include "fd-util.h"
  10 #include "fileio.h"
  11 #include "fs-util.h"
  12 #include "hashmap.h"
  13 #include "log.h"
  14 #include "mountpoint-util.h"
  15 #include "path-util.h"
  16 #include "rm-rf.h"
  17 #include "stat-util.h"
  18 #include "string-util.h"
  19 #include "tests.h"
  20 #include "tmpfile-util.h"
  21
  22 static void test_mount_propagation_flag_one(const char *name, int ret, unsigned long expected) {
  23         unsigned long flags;
  24
  25         log_info("/* %s(%s) */", __func__, strnull(name));
  26
  27         assert_se(mount_propagation_flag_from_string(name, &flags) == ret);
  28
  29         if (ret >= 0) {
  30                 const char *c;
  31
  32                 assert_se(flags == expected);
  33
  34                 c = mount_propagation_flag_to_string(flags);
  35                 if (isempty(name))
  36                         assert_se(isempty(c));
  37                 else
  38                         ASSERT_STREQ(c, name);
  39         }
  40 }
  41
  42 TEST(mount_propagation_flag) {
  43         test_mount_propagation_flag_one("shared", 0, MS_SHARED);
  44         test_mount_propagation_flag_one("slave", 0, MS_SLAVE);
  45         test_mount_propagation_flag_one("private", 0, MS_PRIVATE);
  46         test_mount_propagation_flag_one(NULL, 0, 0);
  47         test_mount_propagation_flag_one("", 0, 0);
  48         test_mount_propagation_flag_one("xxxx", -EINVAL, 0);
  49         test_mount_propagation_flag_one(" ", -EINVAL, 0);
  50 }
  51
  52 TEST(mnt_id) {
  53         _cleanup_fclose_ FILE *f = NULL;
  54         _cleanup_hashmap_free_ Hashmap *h = NULL;
  55         char *p;
  56         void *k;
  57         int r;
  58
  59         assert_se(f = fopen("/proc/self/mountinfo", "re"));
  60         assert_se(h = hashmap_new(&trivial_hash_ops_value_free));
  61
  62         for (;;) {
  63                 _cleanup_free_ char *line = NULL, *path = NULL;
  64                 int mnt_id;
  65
  66                 r = read_line(f, LONG_LINE_MAX, &line);
  67                 if (r == 0)
  68                         break;
  69                 assert_se(r > 0);
  70
  71                 assert_se(sscanf(line, "%i %*s %*s %*s %ms", &mnt_id, &path) == 2);
  72 #if HAS_FEATURE_MEMORY_SANITIZER
  73                 /* We don't know the length of the string, so we need to unpoison it one char at a time */
  74                 for (const char *c = path; ; c++) {
  75                         msan_unpoison(c, 1);
  76                         if (!*c)
  77                                 break;
  78                 }
  79 #endif
  80                 log_debug("mountinfo: %s → %i", path, mnt_id);
  81
  82                 assert_se(hashmap_put(h, INT_TO_PTR(mnt_id), path) >= 0);
  83                 path = NULL;
  84         }
  85
  86         HASHMAP_FOREACH_KEY(p, k, h) {
  87                 int mnt_id = PTR_TO_INT(k), mnt_id2;
  88                 const char *q;
  89
  90                 r = path_get_mnt_id(p, &mnt_id2);
  91                 if (r < 0) {
  92                         log_debug_errno(r, "Failed to get the mnt id of %s: %m", p);
  93                         continue;
  94                 }
  95
  96                 if (mnt_id == mnt_id2) {
  97                         log_debug("mnt ids of %s is %i.", p, mnt_id);
  98                         continue;
  99                 } else
 100                         log_debug("mnt ids of %s are %i (from /proc/self/mountinfo), %i (from path_get_mnt_id()).", p, mnt_id, mnt_id2);
 101
 102                 /* The ids don't match? This can easily happen e.g. running with "unshare --mount-proc".
 103                  * See #11505. */
 104                 assert_se(q = hashmap_get(h, INT_TO_PTR(mnt_id2)));
 105
 106                 assert_se((r = path_is_mount_point_full(p, NULL, 0)) >= 0);
 107                 if (r == 0) {
 108                         /* If the path is not a mount point anymore, then it must be a sub directory of
 109                          * the path corresponds to mnt_id2. */
 110                         log_debug("The path %s for mnt id %i is not a mount point.", p, mnt_id2);
 111                         assert_se(!isempty(path_startswith(p, q)));
 112                 } else {
 113                         /* If the path is still a mount point, then it must be equivalent to the path
 114                          * corresponds to mnt_id2 */
 115                         log_debug("There are multiple mounts on the same path %s.", p);
 116                         assert_se(path_equal(p, q));
 117                 }
 118         }
 119 }
 120
 121 TEST(path_is_mount_point) {
 122         int fd;
 123         char tmp_dir[] = "/tmp/test-path-is-mount-point-XXXXXX";
 124         _cleanup_free_ char *file1 = NULL, *file2 = NULL, *link1 = NULL, *link2 = NULL;
 125         _cleanup_free_ char *dir1 = NULL, *dir1file = NULL, *dirlink1 = NULL, *dirlink1file = NULL;
 126         _cleanup_free_ char *dir2 = NULL, *dir2file = NULL;
 127
 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         assert_se(path_is_mount_point_full("//", NULL, AT_SYMLINK_FOLLOW) > 0);
 131         assert_se(path_is_mount_point_full("//", NULL, 0) > 0);
 132
 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         assert_se(path_is_mount_point_full("/proc/", NULL, AT_SYMLINK_FOLLOW) > 0);
 136         assert_se(path_is_mount_point_full("/proc/", NULL, 0) > 0);
 137
 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         assert_se(path_is_mount_point_full("/proc/1/", NULL, AT_SYMLINK_FOLLOW) == 0);
 141         assert_se(path_is_mount_point_full("/proc/1/", NULL, 0) == 0);
 142
 143         /* we'll create a hierarchy of different kinds of dir/file/link
 144          * layouts:
 145          *
 146          * <tmp>/file1, <tmp>/file2
 147          * <tmp>/link1 -> file1, <tmp>/link2 -> file2
 148          * <tmp>/dir1/
 149          * <tmp>/dir1/file
 150          * <tmp>/dirlink1 -> dir1
 151          * <tmp>/dirlink1file -> dirlink1/file
 152          * <tmp>/dir2/
 153          * <tmp>/dir2/file
 154          */
 155
 156         /* file mountpoints */
 157         ASSERT_NOT_NULL(mkdtemp(tmp_dir));
 158         file1 = path_join(tmp_dir, "file1");
 159         assert_se(file1);
 160         file2 = path_join(tmp_dir, "file2");
 161         assert_se(file2);
 162         fd = open(file1, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 163         assert_se(fd > 0);
 164         close(fd);
 165         fd = open(file2, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 166         assert_se(fd > 0);
 167         close(fd);
 168         link1 = path_join(tmp_dir, "link1");
 169         assert_se(link1);
 170         assert_se(symlink("file1", link1) == 0);
 171         link2 = path_join(tmp_dir, "link2");
 172         assert_se(link1);
 173         assert_se(symlink("file2", link2) == 0);
 174
 175         assert_se(path_is_mount_point_full(file1, NULL, AT_SYMLINK_FOLLOW) == 0);
 176         assert_se(path_is_mount_point_full(file1, NULL, 0) == 0);
 177         assert_se(path_is_mount_point_full(link1, NULL, AT_SYMLINK_FOLLOW) == 0);
 178         assert_se(path_is_mount_point_full(link1, NULL, 0) == 0);
 179
 180         /* directory mountpoints */
 181         dir1 = path_join(tmp_dir, "dir1");
 182         assert_se(dir1);
 183         assert_se(mkdir(dir1, 0755) == 0);
 184         dirlink1 = path_join(tmp_dir, "dirlink1");
 185         assert_se(dirlink1);
 186         assert_se(symlink("dir1", dirlink1) == 0);
 187         dirlink1file = path_join(tmp_dir, "dirlink1file");
 188         assert_se(dirlink1file);
 189         assert_se(symlink("dirlink1/file", dirlink1file) == 0);
 190         dir2 = path_join(tmp_dir, "dir2");
 191         assert_se(dir2);
 192         assert_se(mkdir(dir2, 0755) == 0);
 193
 194         assert_se(path_is_mount_point_full(dir1, NULL, AT_SYMLINK_FOLLOW) == 0);
 195         assert_se(path_is_mount_point_full(dir1, NULL, 0) == 0);
 196         assert_se(path_is_mount_point_full(dirlink1, NULL, AT_SYMLINK_FOLLOW) == 0);
 197         assert_se(path_is_mount_point_full(dirlink1, NULL, 0) == 0);
 198
 199         /* file in subdirectory mountpoints */
 200         dir1file = path_join(dir1, "file");
 201         assert_se(dir1file);
 202         fd = open(dir1file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 203         assert_se(fd > 0);
 204         close(fd);
 205
 206         assert_se(path_is_mount_point_full(dir1file, NULL, AT_SYMLINK_FOLLOW) == 0);
 207         assert_se(path_is_mount_point_full(dir1file, NULL, 0) == 0);
 208         assert_se(path_is_mount_point_full(dirlink1file, NULL, AT_SYMLINK_FOLLOW) == 0);
 209         assert_se(path_is_mount_point_full(dirlink1file, NULL, 0) == 0);
 210
 211         /* these tests will only work as root */
 212         if (mount(file1, file2, NULL, MS_BIND, NULL) >= 0) {
 213                 int rf, rt, rdf, rdt, rlf, rlt, rl1f, rl1t;
 214                 const char *file2d;
 215
 216                 /* files */
 217                 /* capture results in vars, to avoid dangling mounts on failure */
 218                 log_info("%s: %s", __func__, file2);
 219                 rf = path_is_mount_point_full(file2, NULL, 0);
 220                 rt = path_is_mount_point_full(file2, NULL, AT_SYMLINK_FOLLOW);
 221
 222                 file2d = strjoina(file2, "/");
 223                 log_info("%s: %s", __func__, file2d);
 224                 rdf = path_is_mount_point_full(file2d, NULL, 0);
 225                 rdt = path_is_mount_point_full(file2d, NULL, AT_SYMLINK_FOLLOW);
 226
 227                 log_info("%s: %s", __func__, link2);
 228                 rlf = path_is_mount_point_full(link2, NULL, 0);
 229                 rlt = path_is_mount_point_full(link2, NULL, AT_SYMLINK_FOLLOW);
 230
 231                 assert_se(umount(file2) == 0);
 232
 233                 assert_se(rf == 1);
 234                 assert_se(rt == 1);
 235                 assert_se(rdf == -ENOTDIR);
 236                 assert_se(rdt == -ENOTDIR);
 237                 assert_se(rlf == 0);
 238                 assert_se(rlt == 1);
 239
 240                 /* dirs */
 241                 dir2file = path_join(dir2, "file");
 242                 assert_se(dir2file);
 243                 fd = open(dir2file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 244                 assert_se(fd > 0);
 245                 close(fd);
 246
 247                 assert_se(mount(dir2, dir1, NULL, MS_BIND, NULL) >= 0);
 248
 249                 log_info("%s: %s", __func__, dir1);
 250                 rf = path_is_mount_point_full(dir1, NULL, 0);
 251                 rt = path_is_mount_point_full(dir1, NULL, AT_SYMLINK_FOLLOW);
 252                 log_info("%s: %s", __func__, dirlink1);
 253                 rlf = path_is_mount_point_full(dirlink1, NULL, 0);
 254                 rlt = path_is_mount_point_full(dirlink1, NULL, AT_SYMLINK_FOLLOW);
 255                 log_info("%s: %s", __func__, dirlink1file);
 256                 /* its parent is a mount point, but not /file itself */
 257                 rl1f = path_is_mount_point_full(dirlink1file, NULL, 0);
 258                 rl1t = path_is_mount_point_full(dirlink1file, NULL, AT_SYMLINK_FOLLOW);
 259
 260                 assert_se(umount(dir1) == 0);
 261
 262                 assert_se(rf == 1);
 263                 assert_se(rt == 1);
 264                 assert_se(rlf == 0);
 265                 assert_se(rlt == 1);
 266                 assert_se(rl1f == 0);
 267                 assert_se(rl1t == 0);
 268
 269         } else
 270                 log_info("Skipping bind mount file test");
 271
 272         assert_se(rm_rf(tmp_dir, REMOVE_ROOT|REMOVE_PHYSICAL) == 0);
 273 }
 274
 275 TEST(is_mount_point_at) {
 276         _cleanup_(rm_rf_physical_and_freep) char *tmpdir = NULL;
 277         _cleanup_free_ char *pwd = NULL, *tmpdir_basename = NULL;
 278         _cleanup_close_ int fd = -EBADF;
 279         int r;
 280
 281         fd = open("/", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY);
 282         assert_se(fd >= 0);
 283
 284         /* Not allowed, since "/" is a path, not a plain filename */
 285         assert_se(is_mount_point_at(fd, "/", 0) == -EINVAL);
 286         assert_se(is_mount_point_at(fd, "..", 0) == -EINVAL);
 287         assert_se(is_mount_point_at(fd, "../", 0) == -EINVAL);
 288         assert_se(is_mount_point_at(fd, "/proc", 0) == -EINVAL);
 289         assert_se(is_mount_point_at(fd, "/proc/", 0) == -EINVAL);
 290         assert_se(is_mount_point_at(fd, "proc/sys", 0) == -EINVAL);
 291         assert_se(is_mount_point_at(fd, "proc/sys/", 0) == -EINVAL);
 292
 293         /* This one definitely is a mount point */
 294         assert_se(is_mount_point_at(fd, "proc", 0) > 0);
 295         assert_se(is_mount_point_at(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_OK(path_extract_filename(tmpdir, &tmpdir_basename));
 303         ASSERT_OK_ZERO(is_mount_point_at(fd, tmpdir_basename, 0));
 304         ASSERT_OK_ZERO(is_mount_point_at(fd, strjoina(tmpdir_basename, "/"), 0));
 305
 306         safe_close(fd);
 307         fd = open("/proc", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY);
 308         assert_se(fd >= 0);
 309
 310         ASSERT_OK_POSITIVE(is_mount_point_at(fd, NULL, 0));
 311         ASSERT_OK_POSITIVE(is_mount_point_at(fd, "", 0));
 312         ASSERT_OK_POSITIVE(is_mount_point_at(fd, ".", 0));
 313         ASSERT_OK_POSITIVE(is_mount_point_at(fd, "./", 0));
 314         ASSERT_OK_ZERO(is_mount_point_at(fd, "version", 0));
 315
 316         ASSERT_OK(safe_getcwd(&pwd));
 317         ASSERT_OK_ERRNO(fchdir(fd));
 318
 319         ASSERT_OK_POSITIVE(is_mount_point_at(AT_FDCWD, NULL, 0));
 320         ASSERT_OK_POSITIVE(is_mount_point_at(AT_FDCWD, "", 0));
 321         ASSERT_OK_POSITIVE(is_mount_point_at(AT_FDCWD, "./", 0));
 322
 323         ASSERT_OK_ERRNO(chdir(pwd));
 324
 325         safe_close(fd);
 326         fd = open("/proc/version", O_RDONLY|O_CLOEXEC|O_NOCTTY);
 327         assert_se(fd >= 0);
 328
 329         r = is_mount_point_at(fd, NULL, 0);
 330         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 */
 331
 332         if (!mount_new_api_supported())
 333                 return;
 334
 335         /* Symlinks can be mount points with new mount API */
 336         _cleanup_close_ int mfd = -EBADF, rfd = -EBADF;
 337         _cleanup_free_ char *t = NULL;
 338         struct stat st;
 339
 340         safe_close(fd);
 341         ASSERT_OK_ERRNO(fd = open(tmpdir, O_DIRECTORY|O_PATH|O_CLOEXEC));
 342
 343         ASSERT_OK_ERRNO(symlinkat("/usr", fd, "symlink"));
 344
 345         mfd = open_tree(fd, "symlink", AT_SYMLINK_NOFOLLOW|OPEN_TREE_CLONE|OPEN_TREE_CLOEXEC);
 346         if (mfd < 0 && ERRNO_IS_PRIVILEGE(errno))
 347                 return;
 348         ASSERT_OK_ERRNO(mfd);
 349
 350         ASSERT_OK_ERRNO(rfd = openat(fd, "regular", O_CLOEXEC|O_CREAT|O_EXCL, 0644));
 351
 352         ASSERT_OK_ERRNO(move_mount(mfd, "", rfd, "", MOVE_MOUNT_F_EMPTY_PATH|MOVE_MOUNT_T_EMPTY_PATH));
 353
 354         ASSERT_OK_ERRNO(fstatat(fd, "regular", &st, AT_SYMLINK_NOFOLLOW));
 355         ASSERT_OK(stat_verify_symlink(&st));
 356         ASSERT_OK(readlinkat_malloc(fd, "regular", &t));
 357         ASSERT_STREQ(t, "/usr");
 358
 359         ASSERT_OK(is_mount_point_at(fd, "regular", 0));
 360 }
 361
 362 TEST(ms_nosymfollow_supported) {
 363         log_info("MS_NOSYMFOLLOW supported: %s", yes_no(ms_nosymfollow_supported()));
 364 }
 365
 366 TEST(mount_option_supported) {
 367         int r;
 368
 369         r = mount_option_supported("tmpfs", "size", "64M");
 370         log_info("tmpfs supports size=64M: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 371         assert_se(r > 0 || r == -EAGAIN || ERRNO_IS_NEG_PRIVILEGE(r));
 372
 373         r = mount_option_supported("ext4", "discard", NULL);
 374         log_info("ext4 supports discard: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 375         assert_se(r > 0 || r == -EAGAIN || ERRNO_IS_NEG_PRIVILEGE(r));
 376
 377         r = mount_option_supported("tmpfs", "idontexist", "64M");
 378         log_info("tmpfs supports idontexist: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 379         assert_se(IN_SET(r, 0, -EAGAIN) || ERRNO_IS_NEG_PRIVILEGE(r));
 380
 381         r = mount_option_supported("tmpfs", "ialsodontexist", NULL);
 382         log_info("tmpfs supports ialsodontexist: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 383         assert_se(IN_SET(r, 0, -EAGAIN) || ERRNO_IS_NEG_PRIVILEGE(r));
 384
 385         r = mount_option_supported("proc", "hidepid", "1");
 386         log_info("proc supports hidepid=1: %s (%i)", r < 0 ? "don't know" : yes_no(r), r);
 387         assert_se(r >= 0 || r == -EAGAIN || ERRNO_IS_NEG_PRIVILEGE(r));
 388 }
 389
 390 TEST(fstype_can_discard) {
 391         assert_se(fstype_can_discard("ext4"));
 392         assert_se(!fstype_can_discard("squashfs"));
 393         assert_se(!fstype_can_discard("iso9660"));
 394 }
 395
 396 TEST(fstype_can_norecovery) {
 397         ASSERT_STREQ(fstype_norecovery_option("ext4"), "norecovery");
 398         ASSERT_NULL(fstype_norecovery_option("vfat"));
 399         ASSERT_NULL(fstype_norecovery_option("tmpfs"));
 400 }
 401
 402 TEST(fstype_can_fmask_dmask) {
 403         assert_se(fstype_can_fmask_dmask("vfat"));
 404         assert_se(!fstype_can_fmask_dmask("tmpfs"));
 405 }
 406
 407 TEST(path_get_mnt_id_at_null) {
 408         _cleanup_close_ int root_fd = -EBADF, run_fd = -EBADF;
 409         int id1, id2;
 410
 411         assert_se(path_get_mnt_id_at(AT_FDCWD, "/run/", &id1) >= 0);
 412         assert_se(id1 > 0);
 413
 414         assert_se(path_get_mnt_id_at(AT_FDCWD, "/run", &id2) >= 0);
 415         assert_se(id1 == id2);
 416         id2 = -1;
 417
 418         root_fd = open("/", O_DIRECTORY|O_CLOEXEC);
 419         assert_se(root_fd >= 0);
 420
 421         assert_se(path_get_mnt_id_at(root_fd, "/run/", &id2) >= 0);
 422         assert_se(id1 = id2);
 423         id2 = -1;
 424
 425         assert_se(path_get_mnt_id_at(root_fd, "/run", &id2) >= 0);
 426         assert_se(id1 = id2);
 427         id2 = -1;
 428
 429         assert_se(path_get_mnt_id_at(root_fd, "run", &id2) >= 0);
 430         assert_se(id1 = id2);
 431         id2 = -1;
 432
 433         assert_se(path_get_mnt_id_at(root_fd, "run/", &id2) >= 0);
 434         assert_se(id1 = id2);
 435         id2 = -1;
 436
 437         run_fd = openat(root_fd, "run", O_DIRECTORY|O_CLOEXEC);
 438         assert_se(run_fd >= 0);
 439
 440         id2 = -1;
 441         assert_se(path_get_mnt_id_at(run_fd, "", &id2) >= 0);
 442         assert_se(id1 = id2);
 443         id2 = -1;
 444
 445         assert_se(path_get_mnt_id_at(run_fd, NULL, &id2) >= 0);
 446         assert_se(id1 = id2);
 447         id2 = -1;
 448
 449         assert_se(path_get_mnt_id_at(run_fd, ".", &id2) >= 0);
 450         assert_se(id1 = id2);
 451         id2 = -1;
 452 }
 453
 454 static int intro(void) {
 455         /* let's move into our own mount namespace with all propagation from the host turned off, so
 456          * that /proc/self/mountinfo is static and constant for the whole time our test runs. */
 457
 458         if (unshare(CLONE_NEWNS) < 0) {
 459                 if (!ERRNO_IS_PRIVILEGE(errno))
 460                         return log_error_errno(errno, "Failed to detach mount namespace: %m");
 461
 462                 log_notice("Lacking privilege to create separate mount namespace, proceeding in originating mount namespace.");
 463         } else
 464                 assert_se(mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL) >= 0);
 465
 466         return EXIT_SUCCESS;
 467 }
 468
 469 DEFINE_TEST_MAIN_WITH_INTRO(LOG_DEBUG, intro);