src/test/test-fd-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <sys/eventfd.h>
   5 #include <sys/mount.h>
   6 #include <unistd.h>
   7
   8 #include "alloc-util.h"
   9 #include "data-fd-util.h"
  10 #include "fd-util.h"
  11 #include "fileio.h"
  12 #include "fs-util.h"
  13 #include "macro.h"
  14 #include "memory-util.h"
  15 #include "missing_syscall.h"
  16 #include "mkdir.h"
  17 #include "mount-util.h"
  18 #include "namespace-util.h"
  19 #include "path-util.h"
  20 #include "process-util.h"
  21 #include "random-util.h"
  22 #include "rlimit-util.h"
  23 #include "rm-rf.h"
  24 #include "seccomp-util.h"
  25 #include "serialize.h"
  26 #include "stat-util.h"
  27 #include "string-util.h"
  28 #include "tests.h"
  29 #include "tmpfile-util.h"
  30
  31 TEST(close_many) {
  32         int fds[3];
  33         _cleanup_(unlink_tempfilep) char name0[] = "/tmp/test-close-many.XXXXXX";
  34         _cleanup_(unlink_tempfilep) char name1[] = "/tmp/test-close-many.XXXXXX";
  35         _cleanup_(unlink_tempfilep) char name2[] = "/tmp/test-close-many.XXXXXX";
  36
  37         fds[0] = mkostemp_safe(name0);
  38         fds[1] = mkostemp_safe(name1);
  39         fds[2] = mkostemp_safe(name2);
  40
  41         close_many(fds, 2);
  42
  43         assert_se(fcntl(fds[0], F_GETFD) == -1);
  44         assert_se(fcntl(fds[1], F_GETFD) == -1);
  45         assert_se(fcntl(fds[2], F_GETFD) >= 0);
  46
  47         safe_close(fds[2]);
  48 }
  49
  50 TEST(close_nointr) {
  51         _cleanup_(unlink_tempfilep) char name[] = "/tmp/test-test-close_nointr.XXXXXX";
  52         int fd;
  53
  54         fd = mkostemp_safe(name);
  55         assert_se(fd >= 0);
  56         assert_se(close_nointr(fd) >= 0);
  57         assert_se(close_nointr(fd) < 0);
  58 }
  59
  60 TEST(same_fd) {
  61         _cleanup_close_pair_ int p[2];
  62         _cleanup_close_ int a, b, c;
  63
  64         assert_se(pipe2(p, O_CLOEXEC) >= 0);
  65         assert_se((a = fcntl(p[0], F_DUPFD, 3)) >= 0);
  66         assert_se((b = open("/dev/null", O_RDONLY|O_CLOEXEC)) >= 0);
  67         assert_se((c = fcntl(a, F_DUPFD, 3)) >= 0);
  68
  69         assert_se(same_fd(p[0], p[0]) > 0);
  70         assert_se(same_fd(p[1], p[1]) > 0);
  71         assert_se(same_fd(a, a) > 0);
  72         assert_se(same_fd(b, b) > 0);
  73
  74         assert_se(same_fd(a, p[0]) > 0);
  75         assert_se(same_fd(p[0], a) > 0);
  76         assert_se(same_fd(c, p[0]) > 0);
  77         assert_se(same_fd(p[0], c) > 0);
  78         assert_se(same_fd(a, c) > 0);
  79         assert_se(same_fd(c, a) > 0);
  80
  81         assert_se(same_fd(p[0], p[1]) == 0);
  82         assert_se(same_fd(p[1], p[0]) == 0);
  83         assert_se(same_fd(p[0], b) == 0);
  84         assert_se(same_fd(b, p[0]) == 0);
  85         assert_se(same_fd(p[1], a) == 0);
  86         assert_se(same_fd(a, p[1]) == 0);
  87         assert_se(same_fd(p[1], b) == 0);
  88         assert_se(same_fd(b, p[1]) == 0);
  89
  90         assert_se(same_fd(a, b) == 0);
  91         assert_se(same_fd(b, a) == 0);
  92 }
  93
  94 TEST(open_serialization_fd) {
  95         _cleanup_close_ int fd = -EBADF;
  96
  97         fd = open_serialization_fd("test");
  98         assert_se(fd >= 0);
  99
 100         assert_se(write(fd, "test\n", 5) == 5);
 101 }
 102
 103 TEST(open_serialization_file) {
 104         _cleanup_fclose_ FILE *f = NULL;
 105         int r;
 106
 107         r = open_serialization_file("test", &f);
 108         assert_se(r >= 0);
 109         assert_se(f);
 110
 111         assert_se(fwrite("test\n", 1, 5, f) == 5);
 112 }
 113
 114 TEST(fd_move_above_stdio) {
 115         int original_stdin, new_fd;
 116
 117         original_stdin = fcntl(0, F_DUPFD, 3);
 118         assert_se(original_stdin >= 3);
 119         assert_se(close_nointr(0) != EBADF);
 120
 121         new_fd = open("/dev/null", O_RDONLY);
 122         assert_se(new_fd == 0);
 123
 124         new_fd = fd_move_above_stdio(new_fd);
 125         assert_se(new_fd >= 3);
 126
 127         assert_se(dup(original_stdin) == 0);
 128         assert_se(close_nointr(original_stdin) != EBADF);
 129         assert_se(close_nointr(new_fd) != EBADF);
 130 }
 131
 132 TEST(rearrange_stdio) {
 133         pid_t pid;
 134         int r;
 135
 136         r = safe_fork("rearrange", FORK_WAIT|FORK_LOG, &pid);
 137         assert_se(r >= 0);
 138
 139         if (r == 0) {
 140                 _cleanup_free_ char *path = NULL;
 141                 int pipe_read_fd, pair[2];
 142                 char buffer[10];
 143
 144                 /* Child */
 145
 146                 safe_close(STDERR_FILENO); /* Let's close an fd < 2, to make it more interesting */
 147
 148                 assert_se(rearrange_stdio(-EBADF, -EBADF, -EBADF) >= 0);
 149                 /* Reconfigure logging after rearranging stdout/stderr, so we still log to somewhere if the
 150                  * following tests fail, making it slightly less annoying to debug */
 151                 log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
 152                 log_open();
 153
 154                 assert_se(fd_get_path(STDIN_FILENO, &path) >= 0);
 155                 assert_se(path_equal(path, "/dev/null"));
 156                 path = mfree(path);
 157
 158                 assert_se(fd_get_path(STDOUT_FILENO, &path) >= 0);
 159                 assert_se(path_equal(path, "/dev/null"));
 160                 path = mfree(path);
 161
 162                 assert_se(fd_get_path(STDOUT_FILENO, &path) >= 0);
 163                 assert_se(path_equal(path, "/dev/null"));
 164                 path = mfree(path);
 165
 166                 safe_close(STDIN_FILENO);
 167                 safe_close(STDOUT_FILENO);
 168                 safe_close(STDERR_FILENO);
 169
 170                 assert_se(pipe(pair) >= 0);
 171                 assert_se(pair[0] == 0);
 172                 assert_se(pair[1] == 1);
 173                 pipe_read_fd = fd_move_above_stdio(0);
 174                 assert_se(pipe_read_fd >= 3);
 175
 176                 assert_se(open("/dev/full", O_WRONLY|O_CLOEXEC) == 0);
 177                 assert_se(acquire_data_fd("foobar") == 2);
 178
 179                 assert_se(rearrange_stdio(2, 0, 1) >= 0);
 180
 181                 assert_se(write(1, "x", 1) < 0 && errno == ENOSPC);
 182                 assert_se(write(2, "z", 1) == 1);
 183                 assert_se(read(pipe_read_fd, buffer, sizeof(buffer)) == 1);
 184                 assert_se(buffer[0] == 'z');
 185                 assert_se(read(0, buffer, sizeof(buffer)) == 6);
 186                 assert_se(memcmp(buffer, "foobar", 6) == 0);
 187
 188                 assert_se(rearrange_stdio(-EBADF, 1, 2) >= 0);
 189                 assert_se(write(1, "a", 1) < 0 && errno == ENOSPC);
 190                 assert_se(write(2, "y", 1) == 1);
 191                 assert_se(read(pipe_read_fd, buffer, sizeof(buffer)) == 1);
 192                 assert_se(buffer[0] == 'y');
 193
 194                 assert_se(fd_get_path(0, &path) >= 0);
 195                 assert_se(path_equal(path, "/dev/null"));
 196                 path = mfree(path);
 197
 198                 _exit(EXIT_SUCCESS);
 199         }
 200 }
 201
 202 TEST(read_nr_open) {
 203         log_info("nr-open: %i", read_nr_open());
 204 }
 205
 206 static size_t validate_fds(
 207                 bool opened,
 208                 const int *fds,
 209                 size_t n_fds) {
 210
 211         size_t c = 0;
 212
 213         /* Validates that fds in the specified array are one of the following three:
 214          *
 215          *  1. < 0 (test is skipped) or
 216          *  2. opened (if 'opened' param is true) or
 217          *  3. closed (if 'opened' param is false)
 218          */
 219
 220         for (size_t i = 0; i < n_fds; i++) {
 221                 if (fds[i] < 0)
 222                         continue;
 223
 224                 if (opened)
 225                         assert_se(fcntl(fds[i], F_GETFD) >= 0);
 226                 else
 227                         assert_se(fcntl(fds[i], F_GETFD) < 0 && errno == EBADF);
 228
 229                 c++;
 230         }
 231
 232         return c; /* Return number of fds >= 0 in the array */
 233 }
 234
 235 static void test_close_all_fds_inner(void) {
 236         _cleanup_free_ int *fds = NULL, *keep = NULL;
 237         size_t n_fds, n_keep;
 238         int max_fd;
 239
 240         log_info("/* %s */", __func__);
 241
 242         rlimit_nofile_bump(-1);
 243
 244         max_fd = get_max_fd();
 245         assert_se(max_fd > 10);
 246
 247         if (max_fd > 7000) {
 248                 /* If the worst fallback is activated we need to iterate through all possible fds, hence,
 249                  * let's lower the limit a small bit, so that we don't run for too long. Yes, this undoes the
 250                  * rlimit_nofile_bump() call above partially. */
 251
 252                 (void) setrlimit_closest(RLIMIT_NOFILE, &(struct rlimit) { 7000, 7000 });
 253                 max_fd = 7000;
 254         }
 255
 256         /* Try to use 5000 fds, but when we can't bump the rlimit to make that happen use the whole limit minus 10 */
 257         n_fds = MIN(((size_t) max_fd & ~1U) - 10U, 5000U);
 258         assert_se((n_fds & 1U) == 0U); /* make sure even number of fds */
 259
 260         /* Allocate the determined number of fds, always two at a time */
 261         assert_se(fds = new(int, n_fds));
 262         for (size_t i = 0; i < n_fds; i += 2)
 263                 assert_se(pipe2(fds + i, O_CLOEXEC) >= 0);
 264
 265         /* Validate this worked */
 266         assert_se(validate_fds(true, fds, n_fds) == n_fds);
 267
 268         /* Randomized number of fds to keep, but at most every second */
 269         n_keep = (random_u64() % (n_fds / 2));
 270
 271         /* Now randomly select a number of fds from the array above to keep */
 272         assert_se(keep = new(int, n_keep));
 273         for (size_t k = 0; k < n_keep; k++) {
 274                 for (;;) {
 275                         size_t p;
 276
 277                         p = random_u64() % n_fds;
 278                         if (fds[p] >= 0) {
 279                                 keep[k] = TAKE_FD(fds[p]);
 280                                 break;
 281                         }
 282                 }
 283         }
 284
 285         /* Check that all fds from both arrays are still open, and test how many in each are >= 0 */
 286         assert_se(validate_fds(true, fds, n_fds) == n_fds - n_keep);
 287         assert_se(validate_fds(true, keep, n_keep) == n_keep);
 288
 289         /* Close logging fd first, so that we don't confuse it by closing its fd */
 290         log_close();
 291         log_set_open_when_needed(true);
 292         log_settle_target();
 293
 294         /* Close all but the ones to keep */
 295         assert_se(close_all_fds(keep, n_keep) >= 0);
 296
 297         assert_se(validate_fds(false, fds, n_fds) == n_fds - n_keep);
 298         assert_se(validate_fds(true, keep, n_keep) == n_keep);
 299
 300         /* Close everything else too! */
 301         assert_se(close_all_fds(NULL, 0) >= 0);
 302
 303         assert_se(validate_fds(false, fds, n_fds) == n_fds - n_keep);
 304         assert_se(validate_fds(false, keep, n_keep) == n_keep);
 305
 306         log_set_open_when_needed(false);
 307         log_open();
 308 }
 309
 310 static int seccomp_prohibit_close_range(void) {
 311 #if HAVE_SECCOMP && defined(__SNR_close_range)
 312         _cleanup_(seccomp_releasep) scmp_filter_ctx seccomp = NULL;
 313         int r;
 314
 315         r = seccomp_init_for_arch(&seccomp, SCMP_ARCH_NATIVE, SCMP_ACT_ALLOW);
 316         if (r < 0)
 317                 return log_warning_errno(r, "Failed to acquire seccomp context, ignoring: %m");
 318
 319         r = seccomp_rule_add_exact(
 320                         seccomp,
 321                         SCMP_ACT_ERRNO(EPERM),
 322                         SCMP_SYS(close_range),
 323                         0);
 324         if (r < 0)
 325                 return log_warning_errno(r, "Failed to add close_range() rule, ignoring: %m");
 326
 327         r = seccomp_load(seccomp);
 328         if (r < 0)
 329                 return log_warning_errno(r, "Failed to apply close_range() restrictions, ignoring: %m");
 330
 331         return 0;
 332 #else
 333         return log_warning_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Seccomp support or close_range() syscall definition not available.");
 334 #endif
 335 }
 336
 337 TEST(close_all_fds) {
 338         int r;
 339
 340         /* Runs the test four times. Once as is. Once with close_range() syscall blocked via seccomp, once
 341          * with /proc/ overmounted, and once with the combination of both. This should trigger all fallbacks
 342          * in the close_range_all() function. */
 343
 344         r = safe_fork("(caf-plain)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_WAIT, NULL);
 345         if (r == 0) {
 346                 test_close_all_fds_inner();
 347                 _exit(EXIT_SUCCESS);
 348         }
 349         assert_se(r >= 0);
 350
 351         if (geteuid() != 0)
 352                 return (void) log_tests_skipped("Lacking privileges for test with close_range() blocked and /proc/ overmounted");
 353
 354         r = safe_fork("(caf-noproc)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_WAIT|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE, NULL);
 355         if (r == 0) {
 356                 r = mount_nofollow_verbose(LOG_WARNING, "tmpfs", "/proc", "tmpfs", 0, NULL);
 357                 if (r < 0)
 358                         log_notice("Overmounting /proc/ didn't work, skipping close_all_fds() with masked /proc/.");
 359                 else
 360                         test_close_all_fds_inner();
 361                 _exit(EXIT_SUCCESS);
 362         }
 363         assert_se(r >= 0);
 364
 365         if (!is_seccomp_available())
 366                 return (void) log_tests_skipped("Seccomp not available");
 367
 368         r = safe_fork("(caf-seccomp)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_WAIT, NULL);
 369         if (r == 0) {
 370                 r = seccomp_prohibit_close_range();
 371                 if (r < 0)
 372                         log_notice("Applying seccomp filter didn't work, skipping close_all_fds() test with masked close_range().");
 373                 else
 374                         test_close_all_fds_inner();
 375
 376                 _exit(EXIT_SUCCESS);
 377         }
 378         assert_se(r >= 0);
 379
 380         r = safe_fork("(caf-scnp)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG_SIGTERM|FORK_LOG|FORK_WAIT|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE, NULL);
 381         if (r == 0) {
 382                 r = seccomp_prohibit_close_range();
 383                 if (r < 0)
 384                         log_notice("Applying seccomp filter didn't work, skipping close_all_fds() test with masked close_range().");
 385                 else {
 386                         r = mount_nofollow_verbose(LOG_WARNING, "tmpfs", "/proc", "tmpfs", 0, NULL);
 387                         if (r < 0)
 388                                 log_notice("Overmounting /proc/ didn't work, skipping close_all_fds() with masked /proc/.");
 389                         else
 390                                 test_close_all_fds_inner();
 391                 }
 392
 393                 test_close_all_fds_inner();
 394                 _exit(EXIT_SUCCESS);
 395         }
 396         assert_se(r >= 0);
 397 }
 398
 399 TEST(format_proc_fd_path) {
 400         ASSERT_STREQ(FORMAT_PROC_FD_PATH(0), "/proc/self/fd/0");
 401         ASSERT_STREQ(FORMAT_PROC_FD_PATH(1), "/proc/self/fd/1");
 402         ASSERT_STREQ(FORMAT_PROC_FD_PATH(2), "/proc/self/fd/2");
 403         ASSERT_STREQ(FORMAT_PROC_FD_PATH(3), "/proc/self/fd/3");
 404         ASSERT_STREQ(FORMAT_PROC_FD_PATH(2147483647), "/proc/self/fd/2147483647");
 405 }
 406
 407 TEST(fd_reopen) {
 408         _cleanup_close_ int fd1 = -EBADF, fd2 = -EBADF;
 409         struct stat st1, st2;
 410         int fl;
 411
 412         /* Test this with a directory */
 413         fd1 = open("/proc", O_DIRECTORY|O_PATH|O_CLOEXEC);
 414         assert_se(fd1 >= 0);
 415
 416         ASSERT_OK_ERRNO(fstat(fd1, &st1));
 417         assert_se(S_ISDIR(st1.st_mode));
 418
 419         fl = fcntl(fd1, F_GETFL);
 420         assert_se(fl >= 0);
 421         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 422         assert_se(FLAGS_SET(fl, O_PATH));
 423
 424         /* fd_reopen() with O_NOFOLLOW will systematically fail, since it is implemented via a symlink in /proc/self/fd/ */
 425         assert_se(fd_reopen(fd1, O_RDONLY|O_CLOEXEC|O_NOFOLLOW) == -ELOOP);
 426         assert_se(fd_reopen(fd1, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW) == -ELOOP);
 427
 428         fd2 = fd_reopen(fd1, O_RDONLY|O_DIRECTORY|O_CLOEXEC);  /* drop the O_PATH */
 429         assert_se(fd2 >= 0);
 430
 431         ASSERT_OK_ERRNO(fstat(fd2, &st2));
 432         assert_se(S_ISDIR(st2.st_mode));
 433         assert_se(stat_inode_same(&st1, &st2));
 434
 435         fl = fcntl(fd2, F_GETFL);
 436         assert_se(fl >= 0);
 437         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 438         assert_se(!FLAGS_SET(fl, O_PATH));
 439
 440         safe_close(fd1);
 441
 442         fd1 = fd_reopen(fd2, O_DIRECTORY|O_PATH|O_CLOEXEC);  /* reacquire the O_PATH */
 443         assert_se(fd1 >= 0);
 444
 445         ASSERT_OK_ERRNO(fstat(fd1, &st1));
 446         assert_se(S_ISDIR(st1.st_mode));
 447         assert_se(stat_inode_same(&st1, &st2));
 448
 449         fl = fcntl(fd1, F_GETFL);
 450         assert_se(fl >= 0);
 451         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 452         assert_se(FLAGS_SET(fl, O_PATH));
 453
 454         safe_close(fd1);
 455
 456         /* And now, test this with a file. */
 457         fd1 = open("/proc/version", O_PATH|O_CLOEXEC);
 458         assert_se(fd1 >= 0);
 459
 460         ASSERT_OK_ERRNO(fstat(fd1, &st1));
 461         assert_se(S_ISREG(st1.st_mode));
 462
 463         fl = fcntl(fd1, F_GETFL);
 464         assert_se(fl >= 0);
 465         assert_se(!FLAGS_SET(fl, O_DIRECTORY));
 466         assert_se(FLAGS_SET(fl, O_PATH));
 467
 468         assert_se(fd_reopen(fd1, O_RDONLY|O_DIRECTORY|O_CLOEXEC) == -ENOTDIR);
 469         fd2 = fd_reopen(fd1, O_RDONLY|O_CLOEXEC);  /* drop the O_PATH */
 470         assert_se(fd2 >= 0);
 471
 472         ASSERT_OK_ERRNO(fstat(fd2, &st2));
 473         assert_se(S_ISREG(st2.st_mode));
 474         assert_se(stat_inode_same(&st1, &st2));
 475
 476         fl = fcntl(fd2, F_GETFL);
 477         assert_se(fl >= 0);
 478         assert_se(!FLAGS_SET(fl, O_DIRECTORY));
 479         assert_se(!FLAGS_SET(fl, O_PATH));
 480
 481         safe_close(fd1);
 482
 483         assert_se(fd_reopen(fd2, O_DIRECTORY|O_PATH|O_CLOEXEC) == -ENOTDIR);
 484         fd1 = fd_reopen(fd2, O_PATH|O_CLOEXEC);  /* reacquire the O_PATH */
 485         assert_se(fd1 >= 0);
 486
 487         ASSERT_OK_ERRNO(fstat(fd1, &st1));
 488         assert_se(S_ISREG(st1.st_mode));
 489         assert_se(stat_inode_same(&st1, &st2));
 490
 491         fl = fcntl(fd1, F_GETFL);
 492         assert_se(fl >= 0);
 493         assert_se(!FLAGS_SET(fl, O_DIRECTORY));
 494         assert_se(FLAGS_SET(fl, O_PATH));
 495
 496         /* Also check the right error is generated if the fd is already closed */
 497         safe_close(fd1);
 498         assert_se(fd_reopen(fd1, O_RDONLY|O_CLOEXEC) == -EBADF);
 499         fd1 = -EBADF;
 500
 501         /* Validate what happens if we reopen a symlink */
 502         fd1 = open("/proc/self", O_PATH|O_CLOEXEC|O_NOFOLLOW);
 503         assert_se(fd1 >= 0);
 504         ASSERT_OK_ERRNO(fstat(fd1, &st1));
 505         assert_se(S_ISLNK(st1.st_mode));
 506
 507         fd2 = fd_reopen(fd1, O_PATH|O_CLOEXEC);
 508         assert_se(fd2 >= 0);
 509         ASSERT_OK_ERRNO(fstat(fd2, &st2));
 510         assert_se(S_ISLNK(st2.st_mode));
 511         assert_se(stat_inode_same(&st1, &st2));
 512         fd2 = safe_close(fd2);
 513
 514         /* So here's the thing: if we have an O_PATH fd to a symlink, we *cannot* convert it to a regular fd
 515          * with that. i.e. you cannot have the VFS follow a symlink pinned via an O_PATH fd. */
 516         assert_se(fd_reopen(fd1, O_RDONLY|O_CLOEXEC) == -ELOOP);
 517 }
 518
 519 TEST(fd_reopen_condition) {
 520         _cleanup_close_ int fd1 = -EBADF, fd3 = -EBADF;
 521         int fd2, fl;
 522
 523         /* Open without O_PATH */
 524         fd1 = open("/usr/", O_RDONLY|O_DIRECTORY|O_CLOEXEC);
 525         assert_se(fd1 >= 0);
 526
 527         fl = fcntl(fd1, F_GETFL);
 528         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 529         assert_se(!FLAGS_SET(fl, O_PATH));
 530
 531         fd2 = fd_reopen_condition(fd1, O_DIRECTORY, O_DIRECTORY|O_PATH, &fd3);
 532         assert_se(fd2 == fd1);
 533         assert_se(fd3 < 0);
 534
 535         /* Switch on O_PATH */
 536         fd2 = fd_reopen_condition(fd1, O_DIRECTORY|O_PATH, O_DIRECTORY|O_PATH, &fd3);
 537         assert_se(fd2 != fd1);
 538         assert_se(fd3 == fd2);
 539
 540         fl = fcntl(fd2, F_GETFL);
 541         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 542         assert_se(FLAGS_SET(fl, O_PATH));
 543
 544         close_and_replace(fd1, fd3);
 545
 546         fd2 = fd_reopen_condition(fd1, O_DIRECTORY|O_PATH, O_DIRECTORY|O_PATH, &fd3);
 547         assert_se(fd2 == fd1);
 548         assert_se(fd3 < 0);
 549
 550         /* Switch off O_PATH again */
 551         fd2 = fd_reopen_condition(fd1, O_DIRECTORY, O_DIRECTORY|O_PATH, &fd3);
 552         assert_se(fd2 != fd1);
 553         assert_se(fd3 == fd2);
 554
 555         fl = fcntl(fd2, F_GETFL);
 556         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 557         assert_se(!FLAGS_SET(fl, O_PATH));
 558
 559         close_and_replace(fd1, fd3);
 560
 561         fd2 = fd_reopen_condition(fd1, O_DIRECTORY, O_DIRECTORY|O_PATH, &fd3);
 562         assert_se(fd2 == fd1);
 563         assert_se(fd3 < 0);
 564 }
 565
 566 TEST(take_fd) {
 567         _cleanup_close_ int fd1 = -EBADF, fd2 = -EBADF;
 568         int array[2] = EBADF_PAIR, i = 0;
 569
 570         assert_se(fd1 == -EBADF);
 571         assert_se(fd2 == -EBADF);
 572
 573         fd1 = eventfd(0, EFD_CLOEXEC);
 574         assert_se(fd1 >= 0);
 575
 576         fd2 = TAKE_FD(fd1);
 577         assert_se(fd1 == -EBADF);
 578         assert_se(fd2 >= 0);
 579
 580         assert_se(array[0] == -EBADF);
 581         assert_se(array[1] == -EBADF);
 582
 583         array[0] = TAKE_FD(fd2);
 584         assert_se(fd1 == -EBADF);
 585         assert_se(fd2 == -EBADF);
 586         assert_se(array[0] >= 0);
 587         assert_se(array[1] == -EBADF);
 588
 589         array[1] = TAKE_FD(array[i]);
 590         assert_se(array[0] == -EBADF);
 591         assert_se(array[1] >= 0);
 592
 593         i = 1 - i;
 594         array[0] = TAKE_FD(*(array + i));
 595         assert_se(array[0] >= 0);
 596         assert_se(array[1] == -EBADF);
 597
 598         i = 1 - i;
 599         fd1 = TAKE_FD(array[i]);
 600         assert_se(fd1 >= 0);
 601         assert_se(array[0] == -EBADF);
 602         assert_se(array[1] == -EBADF);
 603 }
 604
 605 TEST(dir_fd_is_root) {
 606         _cleanup_close_ int fd = -EBADF;
 607         int r;
 608
 609         assert_se(dir_fd_is_root_or_cwd(AT_FDCWD) > 0);
 610
 611         assert_se((fd = open("/", O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW)) >= 0);
 612         assert_se(dir_fd_is_root(fd) > 0);
 613         assert_se(dir_fd_is_root_or_cwd(fd) > 0);
 614
 615         fd = safe_close(fd);
 616
 617         assert_se((fd = open("/usr", O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW)) >= 0);
 618         assert_se(dir_fd_is_root(fd) == 0);
 619         assert_se(dir_fd_is_root_or_cwd(fd) == 0);
 620
 621         r = detach_mount_namespace();
 622         if (r < 0)
 623                 return (void) log_tests_skipped_errno(r, "Failed to detach mount namespace");
 624
 625         _cleanup_(rm_rf_physical_and_freep) char *tmp = NULL;
 626         _cleanup_free_ char *x = NULL, *y = NULL;
 627
 628         assert_se(mkdtemp_malloc("/tmp/test-mkdir-XXXXXX", &tmp) >= 0);
 629         assert_se(x = path_join(tmp, "x"));
 630         assert_se(y = path_join(tmp, "x/y"));
 631         assert_se(mkdir_p(y, 0755) >= 0);
 632         assert_se(mount_nofollow_verbose(LOG_DEBUG, x, y, NULL, MS_BIND, NULL) >= 0);
 633
 634         fd = safe_close(fd);
 635
 636         assert_se((fd = open(tmp, O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW)) >= 0);
 637         assert_se(dir_fd_is_root(fd) == 0);
 638         assert_se(dir_fd_is_root_or_cwd(fd) == 0);
 639
 640         fd = safe_close(fd);
 641
 642         assert_se((fd = open(x, O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW)) >= 0);
 643         assert_se(dir_fd_is_root(fd) == 0);
 644         assert_se(dir_fd_is_root_or_cwd(fd) == 0);
 645
 646         fd = safe_close(fd);
 647
 648         assert_se((fd = open(y, O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW)) >= 0);
 649         assert_se(dir_fd_is_root(fd) == 0);
 650         assert_se(dir_fd_is_root_or_cwd(fd) == 0);
 651 }
 652
 653 TEST(fds_are_same_mount) {
 654         _cleanup_close_ int fd1 = -EBADF, fd2 = -EBADF, fd3 = -EBADF, fd4 = -EBADF;
 655
 656         fd1 = open("/sys", O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW);
 657         fd2 = open("/proc", O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW);
 658         fd3 = open("/proc", O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW);
 659         fd4 = open("/", O_CLOEXEC|O_PATH|O_DIRECTORY|O_NOFOLLOW);
 660
 661         if (fd1 < 0 || fd2 < 0 || fd3 < 0 || fd4 < 0)
 662                 return (void) log_tests_skipped_errno(errno, "Failed to open /sys or /proc or /");
 663
 664         if (fds_are_same_mount(fd1, fd4) > 0 && fds_are_same_mount(fd2, fd4) > 0)
 665                 return (void) log_tests_skipped("Cannot test fds_are_same_mount() as /sys and /proc are not mounted");
 666
 667         assert_se(fds_are_same_mount(fd1, fd2) == 0);
 668         assert_se(fds_are_same_mount(fd2, fd3) > 0);
 669 }
 670
 671 TEST(fd_get_path) {
 672         _cleanup_(rm_rf_physical_and_freep) char *t = NULL;
 673         _cleanup_close_ int tfd = -EBADF, fd = -EBADF;
 674         _cleanup_free_ char *p = NULL, *q = NULL, *saved_cwd = NULL;
 675
 676         tfd = mkdtemp_open(NULL, O_PATH, &t);
 677         assert_se(tfd >= 0);
 678         assert_se(fd_get_path(tfd, &p) >= 0);
 679         ASSERT_STREQ(p, t);
 680
 681         p = mfree(p);
 682
 683         assert_se(safe_getcwd(&saved_cwd) >= 0);
 684         assert_se(chdir(t) >= 0);
 685
 686         assert_se(fd_get_path(AT_FDCWD, &p) >= 0);
 687         ASSERT_STREQ(p, t);
 688
 689         p = mfree(p);
 690
 691         assert_se(q = path_join(t, "regular"));
 692         assert_se(touch(q) >= 0);
 693         assert_se(mkdirat_parents(tfd, "subdir/symlink", 0755) >= 0);
 694         assert_se(symlinkat("../regular", tfd, "subdir/symlink") >= 0);
 695         assert_se(symlinkat("subdir", tfd, "symdir") >= 0);
 696
 697         fd = openat(tfd, "regular", O_CLOEXEC|O_PATH);
 698         assert_se(fd >= 0);
 699         assert_se(fd_get_path(fd, &p) >= 0);
 700         ASSERT_STREQ(p, q);
 701
 702         p = mfree(p);
 703         fd = safe_close(fd);
 704
 705         fd = openat(AT_FDCWD, "regular", O_CLOEXEC|O_PATH);
 706         assert_se(fd >= 0);
 707         assert_se(fd_get_path(fd, &p) >= 0);
 708         ASSERT_STREQ(p, q);
 709
 710         p = mfree(p);
 711         fd = safe_close(fd);
 712
 713         fd = openat(tfd, "subdir/symlink", O_CLOEXEC|O_PATH);
 714         assert_se(fd >= 0);
 715         assert_se(fd_verify_regular(fd) >= 0);
 716         assert_se(fd_get_path(fd, &p) >= 0);
 717         ASSERT_STREQ(p, q);
 718
 719         p = mfree(p);
 720         fd = safe_close(fd);
 721
 722         fd = openat(AT_FDCWD, "subdir/symlink", O_CLOEXEC|O_PATH);
 723         assert_se(fd >= 0);
 724         assert_se(fd_verify_regular(fd) >= 0);
 725         assert_se(fd_get_path(fd, &p) >= 0);
 726         ASSERT_STREQ(p, q);
 727
 728         p = mfree(p);
 729         fd = safe_close(fd);
 730
 731         fd = openat(tfd, "symdir//./symlink", O_CLOEXEC|O_PATH);
 732         assert_se(fd >= 0);
 733         assert_se(fd_verify_regular(fd) >= 0);
 734         assert_se(fd_get_path(fd, &p) >= 0);
 735         ASSERT_STREQ(p, q);
 736
 737         p = mfree(p);
 738         fd = safe_close(fd);
 739
 740         fd = openat(AT_FDCWD, "symdir//./symlink", O_CLOEXEC|O_PATH);
 741         assert_se(fd >= 0);
 742         assert_se(fd_verify_regular(fd) >= 0);
 743         assert_se(fd_get_path(fd, &p) >= 0);
 744         ASSERT_STREQ(p, q);
 745
 746         p = mfree(p);
 747         q = mfree(q);
 748         fd = safe_close(fd);
 749
 750         assert_se(q = path_join(t, "subdir/symlink"));
 751         fd = openat(tfd, "subdir/symlink", O_CLOEXEC|O_PATH|O_NOFOLLOW);
 752         assert_se(fd >= 0);
 753         assert_se(fd_verify_regular(fd) == -ELOOP);
 754         assert_se(fd_get_path(fd, &p) >= 0);
 755         ASSERT_STREQ(p, q);
 756
 757         p = mfree(p);
 758         fd = safe_close(fd);
 759
 760         fd = openat(AT_FDCWD, "subdir/symlink", O_CLOEXEC|O_PATH|O_NOFOLLOW);
 761         assert_se(fd >= 0);
 762         assert_se(fd_verify_regular(fd) == -ELOOP);
 763         assert_se(fd_get_path(fd, &p) >= 0);
 764         ASSERT_STREQ(p, q);
 765
 766         p = mfree(p);
 767         fd = safe_close(fd);
 768
 769         fd = openat(tfd, "symdir//./symlink", O_CLOEXEC|O_PATH|O_NOFOLLOW);
 770         assert_se(fd >= 0);
 771         assert_se(fd_verify_regular(fd) == -ELOOP);
 772         assert_se(fd_get_path(fd, &p) >= 0);
 773         ASSERT_STREQ(p, q);
 774
 775         p = mfree(p);
 776         fd = safe_close(fd);
 777
 778         fd = openat(AT_FDCWD, "symdir//./symlink", O_CLOEXEC|O_PATH|O_NOFOLLOW);
 779         assert_se(fd >= 0);
 780         assert_se(fd_verify_regular(fd) == -ELOOP);
 781         assert_se(fd_get_path(fd, &p) >= 0);
 782         ASSERT_STREQ(p, q);
 783
 784         assert_se(chdir(saved_cwd) >= 0);
 785 }
 786
 787 DEFINE_TEST_MAIN(LOG_DEBUG);