src/core/automount.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <limits.h>
   6 #include <linux/auto_dev-ioctl.h>
   7 #include <linux/auto_fs4.h>
   8 #include <sys/epoll.h>
   9 #include <sys/mount.h>
  10 #include <sys/stat.h>
  11 #include <unistd.h>
  12
  13 #include "alloc-util.h"
  14 #include "async.h"
  15 #include "automount.h"
  16 #include "bus-error.h"
  17 #include "bus-util.h"
  18 #include "dbus-automount.h"
  19 #include "fd-util.h"
  20 #include "format-util.h"
  21 #include "io-util.h"
  22 #include "label.h"
  23 #include "mkdir.h"
  24 #include "mount-util.h"
  25 #include "mount.h"
  26 #include "parse-util.h"
  27 #include "path-util.h"
  28 #include "process-util.h"
  29 #include "serialize.h"
  30 #include "special.h"
  31 #include "stdio-util.h"
  32 #include "string-table.h"
  33 #include "string-util.h"
  34 #include "unit-name.h"
  35 #include "unit.h"
  36
  37 static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
  38         [AUTOMOUNT_DEAD] = UNIT_INACTIVE,
  39         [AUTOMOUNT_WAITING] = UNIT_ACTIVE,
  40         [AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
  41         [AUTOMOUNT_FAILED] = UNIT_FAILED
  42 };
  43
  44 struct expire_data {
  45         int dev_autofs_fd;
  46         int ioctl_fd;
  47 };
  48
  49 static inline void expire_data_free(struct expire_data *data) {
  50         if (!data)
  51                 return;
  52
  53         safe_close(data->dev_autofs_fd);
  54         safe_close(data->ioctl_fd);
  55         free(data);
  56 }
  57
  58 DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
  59
  60 static int open_dev_autofs(Manager *m);
  61 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  62 static int automount_start_expire(Automount *a);
  63 static void automount_stop_expire(Automount *a);
  64 static int automount_send_ready(Automount *a, Set *tokens, int status);
  65
  66 static void automount_init(Unit *u) {
  67         Automount *a = AUTOMOUNT(u);
  68
  69         assert(u);
  70         assert(u->load_state == UNIT_STUB);
  71
  72         a->pipe_fd = -1;
  73         a->directory_mode = 0755;
  74         UNIT(a)->ignore_on_isolate = true;
  75 }
  76
  77 static void unmount_autofs(Automount *a) {
  78         int r;
  79
  80         assert(a);
  81
  82         if (a->pipe_fd < 0)
  83                 return;
  84
  85         a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
  86         a->pipe_fd = safe_close(a->pipe_fd);
  87
  88         /* If we reload/reexecute things we keep the mount point around */
  89         if (!IN_SET(UNIT(a)->manager->objective, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
  90
  91                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
  92                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
  93
  94                 if (a->where) {
  95                         r = repeat_unmount(a->where, MNT_DETACH);
  96                         if (r < 0)
  97                                 log_error_errno(r, "Failed to unmount: %m");
  98                 }
  99         }
 100 }
 101
 102 static void automount_done(Unit *u) {
 103         Automount *a = AUTOMOUNT(u);
 104
 105         assert(a);
 106
 107         unmount_autofs(a);
 108
 109         a->where = mfree(a->where);
 110
 111         a->tokens = set_free(a->tokens);
 112         a->expire_tokens = set_free(a->expire_tokens);
 113
 114         a->expire_event_source = sd_event_source_unref(a->expire_event_source);
 115 }
 116
 117 static int automount_add_trigger_dependencies(Automount *a) {
 118         Unit *x;
 119         int r;
 120
 121         assert(a);
 122
 123         r = unit_load_related_unit(UNIT(a), ".mount", &x);
 124         if (r < 0)
 125                 return r;
 126
 127         return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 128 }
 129
 130 static int automount_add_mount_dependencies(Automount *a) {
 131         _cleanup_free_ char *parent = NULL;
 132
 133         assert(a);
 134
 135         parent = dirname_malloc(a->where);
 136         if (!parent)
 137                 return -ENOMEM;
 138
 139         return unit_require_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT);
 140 }
 141
 142 static int automount_add_default_dependencies(Automount *a) {
 143         int r;
 144
 145         assert(a);
 146
 147         if (!UNIT(a)->default_dependencies)
 148                 return 0;
 149
 150         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 151                 return 0;
 152
 153         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 154         if (r < 0)
 155                 return r;
 156
 157         return 0;
 158 }
 159
 160 static int automount_verify(Automount *a) {
 161         _cleanup_free_ char *e = NULL;
 162         int r;
 163
 164         assert(a);
 165
 166         if (UNIT(a)->load_state != UNIT_LOADED)
 167                 return 0;
 168
 169         if (path_equal(a->where, "/")) {
 170                 log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing.");
 171                 return -ENOEXEC;
 172         }
 173
 174         r = unit_name_from_path(a->where, ".automount", &e);
 175         if (r < 0)
 176                 return log_unit_error_errno(UNIT(a), r, "Failed to generate unit name from path: %m");
 177
 178         if (!unit_has_name(UNIT(a), e)) {
 179                 log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing.");
 180                 return -ENOEXEC;
 181         }
 182
 183         return 0;
 184 }
 185
 186 static int automount_set_where(Automount *a) {
 187         int r;
 188
 189         assert(a);
 190
 191         if (a->where)
 192                 return 0;
 193
 194         r = unit_name_to_path(UNIT(a)->id, &a->where);
 195         if (r < 0)
 196                 return r;
 197
 198         path_simplify(a->where, false);
 199         return 1;
 200 }
 201
 202 static int automount_load(Unit *u) {
 203         Automount *a = AUTOMOUNT(u);
 204         int r;
 205
 206         assert(u);
 207         assert(u->load_state == UNIT_STUB);
 208
 209         /* Load a .automount file */
 210         r = unit_load_fragment_and_dropin(u);
 211         if (r < 0)
 212                 return r;
 213
 214         if (u->load_state == UNIT_LOADED) {
 215                 r = automount_set_where(a);
 216                 if (r < 0)
 217                         return r;
 218
 219                 r = automount_add_trigger_dependencies(a);
 220                 if (r < 0)
 221                         return r;
 222
 223                 r = automount_add_mount_dependencies(a);
 224                 if (r < 0)
 225                         return r;
 226
 227                 r = automount_add_default_dependencies(a);
 228                 if (r < 0)
 229                         return r;
 230         }
 231
 232         return automount_verify(a);
 233 }
 234
 235 static void automount_set_state(Automount *a, AutomountState state) {
 236         AutomountState old_state;
 237         assert(a);
 238
 239         old_state = a->state;
 240         a->state = state;
 241
 242         if (state != AUTOMOUNT_RUNNING)
 243                 automount_stop_expire(a);
 244
 245         if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 246                 unmount_autofs(a);
 247
 248         if (state != old_state)
 249                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 250
 251         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], 0);
 252 }
 253
 254 static int automount_coldplug(Unit *u) {
 255         Automount *a = AUTOMOUNT(u);
 256         int r;
 257
 258         assert(a);
 259         assert(a->state == AUTOMOUNT_DEAD);
 260
 261         if (a->deserialized_state == a->state)
 262                 return 0;
 263
 264         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 265
 266                 r = automount_set_where(a);
 267                 if (r < 0)
 268                         return r;
 269
 270                 r = open_dev_autofs(u->manager);
 271                 if (r < 0)
 272                         return r;
 273
 274                 assert(a->pipe_fd >= 0);
 275
 276                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 277                 if (r < 0)
 278                         return r;
 279
 280                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 281                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 282                         r = automount_start_expire(a);
 283                         if (r < 0)
 284                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 285                 }
 286
 287                 automount_set_state(a, a->deserialized_state);
 288         }
 289
 290         return 0;
 291 }
 292
 293 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 294         char time_string[FORMAT_TIMESPAN_MAX];
 295         Automount *a = AUTOMOUNT(u);
 296
 297         assert(a);
 298
 299         fprintf(f,
 300                 "%sAutomount State: %s\n"
 301                 "%sResult: %s\n"
 302                 "%sWhere: %s\n"
 303                 "%sDirectoryMode: %04o\n"
 304                 "%sTimeoutIdleUSec: %s\n",
 305                 prefix, automount_state_to_string(a->state),
 306                 prefix, automount_result_to_string(a->result),
 307                 prefix, a->where,
 308                 prefix, a->directory_mode,
 309                 prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
 310 }
 311
 312 static void automount_enter_dead(Automount *a, AutomountResult f) {
 313         assert(a);
 314
 315         if (a->result == AUTOMOUNT_SUCCESS)
 316                 a->result = f;
 317
 318         unit_log_result(UNIT(a), a->result == AUTOMOUNT_SUCCESS, automount_result_to_string(a->result));
 319         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 320 }
 321
 322 static int open_dev_autofs(Manager *m) {
 323         struct autofs_dev_ioctl param;
 324
 325         assert(m);
 326
 327         if (m->dev_autofs_fd >= 0)
 328                 return m->dev_autofs_fd;
 329
 330         (void) label_fix("/dev/autofs", 0);
 331
 332         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 333         if (m->dev_autofs_fd < 0)
 334                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 335
 336         init_autofs_dev_ioctl(&param);
 337         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 338                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 339                 return -errno;
 340         }
 341
 342         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 343
 344         return m->dev_autofs_fd;
 345 }
 346
 347 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 348         struct autofs_dev_ioctl *param;
 349         size_t l;
 350
 351         assert(dev_autofs_fd >= 0);
 352         assert(where);
 353
 354         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 355         param = alloca(l);
 356
 357         init_autofs_dev_ioctl(param);
 358         param->size = l;
 359         param->ioctlfd = -1;
 360         param->openmount.devid = devid;
 361         strcpy(param->path, where);
 362
 363         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 364                 return -errno;
 365
 366         if (param->ioctlfd < 0)
 367                 return -EIO;
 368
 369         (void) fd_cloexec(param->ioctlfd, true);
 370         return param->ioctlfd;
 371 }
 372
 373 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 374         uint32_t major, minor;
 375         struct autofs_dev_ioctl param;
 376
 377         assert(dev_autofs_fd >= 0);
 378         assert(ioctl_fd >= 0);
 379
 380         init_autofs_dev_ioctl(&param);
 381         param.ioctlfd = ioctl_fd;
 382
 383         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 384                 return -errno;
 385
 386         major = param.protover.version;
 387
 388         init_autofs_dev_ioctl(&param);
 389         param.ioctlfd = ioctl_fd;
 390
 391         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 392                 return -errno;
 393
 394         minor = param.protosubver.sub_version;
 395
 396         log_debug("Autofs protocol version %i.%i", major, minor);
 397         return 0;
 398 }
 399
 400 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 401         struct autofs_dev_ioctl param;
 402
 403         assert(dev_autofs_fd >= 0);
 404         assert(ioctl_fd >= 0);
 405
 406         init_autofs_dev_ioctl(&param);
 407         param.ioctlfd = ioctl_fd;
 408
 409         if (usec == USEC_INFINITY)
 410                 param.timeout.timeout = 0;
 411         else
 412                 /* Convert to seconds, rounding up. */
 413                 param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
 414
 415         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 416                 return -errno;
 417
 418         return 0;
 419 }
 420
 421 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 422         struct autofs_dev_ioctl param;
 423
 424         assert(dev_autofs_fd >= 0);
 425         assert(ioctl_fd >= 0);
 426
 427         init_autofs_dev_ioctl(&param);
 428         param.ioctlfd = ioctl_fd;
 429
 430         if (status != 0) {
 431                 param.fail.token = token;
 432                 param.fail.status = status;
 433         } else
 434                 param.ready.token = token;
 435
 436         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 437                 return -errno;
 438
 439         return 0;
 440 }
 441
 442 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 443         _cleanup_close_ int ioctl_fd = -1;
 444         unsigned token;
 445         int r;
 446
 447         assert(a);
 448         assert(status <= 0);
 449
 450         if (set_isempty(tokens))
 451                 return 0;
 452
 453         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 454         if (ioctl_fd < 0)
 455                 return ioctl_fd;
 456
 457         if (status != 0)
 458                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 459         else
 460                 log_unit_debug(UNIT(a), "Sending success.");
 461
 462         r = 0;
 463
 464         /* Autofs thankfully does not hand out 0 as a token */
 465         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 466                 int k;
 467
 468                 /* Autofs fun fact:
 469                  *
 470                  * if you pass a positive status code here, kernels
 471                  * prior to 4.12 will freeze! Yay! */
 472
 473                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 474                                       ioctl_fd,
 475                                       token,
 476                                       status);
 477                 if (k < 0)
 478                         r = k;
 479         }
 480
 481         return r;
 482 }
 483
 484 static void automount_trigger_notify(Unit *u, Unit *other) {
 485         Automount *a = AUTOMOUNT(u);
 486         int r;
 487
 488         assert(a);
 489         assert(other);
 490
 491         /* Filter out invocations with bogus state */
 492         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 493                 return;
 494
 495         /* Don't propagate state changes from the mount if we are already down */
 496         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 497                 return;
 498
 499         /* Propagate start limit hit state */
 500         if (other->start_limit_hit) {
 501                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 502                 return;
 503         }
 504
 505         /* Don't propagate anything if there's still a job queued */
 506         if (other->job)
 507                 return;
 508
 509         /* The mount is successfully established */
 510         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 511                 (void) automount_send_ready(a, a->tokens, 0);
 512
 513                 r = automount_start_expire(a);
 514                 if (r < 0)
 515                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 516
 517                 automount_set_state(a, AUTOMOUNT_RUNNING);
 518         }
 519
 520         if (IN_SET(MOUNT(other)->state,
 521                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 522                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 523                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 524                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 525                    MOUNT_FAILED)) {
 526
 527                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 528         }
 529
 530         if (MOUNT(other)->state == MOUNT_DEAD)
 531                 (void) automount_send_ready(a, a->expire_tokens, 0);
 532
 533         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 534         if (IN_SET(MOUNT(other)->state,
 535                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 536                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 537                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 538                    MOUNT_FAILED)) {
 539
 540                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 541
 542                 automount_set_state(a, AUTOMOUNT_WAITING);
 543         }
 544 }
 545
 546 static void automount_enter_waiting(Automount *a) {
 547         _cleanup_close_ int ioctl_fd = -1;
 548         int p[2] = { -1, -1 };
 549         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 550         char options[STRLEN("fd=,pgrp=,minproto=5,maxproto=5,direct")
 551                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 552         bool mounted = false;
 553         int r, dev_autofs_fd;
 554         struct stat st;
 555
 556         assert(a);
 557         assert(a->pipe_fd < 0);
 558         assert(a->where);
 559
 560         set_clear(a->tokens);
 561
 562         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 563         if (r < 0)
 564                 goto fail;
 565
 566         (void) mkdir_p_label(a->where, 0555);
 567
 568         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 569
 570         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 571         if (dev_autofs_fd < 0) {
 572                 r = dev_autofs_fd;
 573                 goto fail;
 574         }
 575
 576         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 577                 r = -errno;
 578                 goto fail;
 579         }
 580
 581         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 582         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 583         if (mount(name, a->where, "autofs", 0, options) < 0) {
 584                 r = -errno;
 585                 goto fail;
 586         }
 587
 588         mounted = true;
 589
 590         p[1] = safe_close(p[1]);
 591
 592         if (stat(a->where, &st) < 0) {
 593                 r = -errno;
 594                 goto fail;
 595         }
 596
 597         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 598         if (ioctl_fd < 0) {
 599                 r = ioctl_fd;
 600                 goto fail;
 601         }
 602
 603         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 604         if (r < 0)
 605                 goto fail;
 606
 607         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 608         if (r < 0)
 609                 goto fail;
 610
 611         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 612         if (r < 0)
 613                 goto fail;
 614
 615         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 616
 617         a->pipe_fd = p[0];
 618         a->dev_id = st.st_dev;
 619
 620         automount_set_state(a, AUTOMOUNT_WAITING);
 621
 622         return;
 623
 624 fail:
 625         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 626
 627         safe_close_pair(p);
 628
 629         if (mounted) {
 630                 r = repeat_unmount(a->where, MNT_DETACH);
 631                 if (r < 0)
 632                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 633         }
 634
 635         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 636 }
 637
 638 static void *expire_thread(void *p) {
 639         struct autofs_dev_ioctl param;
 640         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 641         int r;
 642
 643         assert(data->dev_autofs_fd >= 0);
 644         assert(data->ioctl_fd >= 0);
 645
 646         init_autofs_dev_ioctl(&param);
 647         param.ioctlfd = data->ioctl_fd;
 648
 649         do {
 650                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 651         } while (r >= 0);
 652
 653         if (errno != EAGAIN)
 654                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 655
 656         return NULL;
 657 }
 658
 659 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 660         Automount *a = AUTOMOUNT(userdata);
 661         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 662         int r;
 663
 664         assert(a);
 665         assert(source == a->expire_event_source);
 666
 667         data = new0(struct expire_data, 1);
 668         if (!data)
 669                 return log_oom();
 670
 671         data->ioctl_fd = -1;
 672
 673         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 674         if (data->dev_autofs_fd < 0)
 675                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 676
 677         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 678         if (data->ioctl_fd < 0)
 679                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 680
 681         r = asynchronous_job(expire_thread, data);
 682         if (r < 0)
 683                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 684
 685         data = NULL;
 686
 687         return automount_start_expire(a);
 688 }
 689
 690 static int automount_start_expire(Automount *a) {
 691         int r;
 692         usec_t timeout;
 693
 694         assert(a);
 695
 696         if (a->timeout_idle_usec == 0)
 697                 return 0;
 698
 699         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 700
 701         if (a->expire_event_source) {
 702                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 703                 if (r < 0)
 704                         return r;
 705
 706                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 707         }
 708
 709         r = sd_event_add_time(
 710                         UNIT(a)->manager->event,
 711                         &a->expire_event_source,
 712                         CLOCK_MONOTONIC, timeout, 0,
 713                         automount_dispatch_expire, a);
 714         if (r < 0)
 715                 return r;
 716
 717         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 718
 719         return 0;
 720 }
 721
 722 static void automount_stop_expire(Automount *a) {
 723         assert(a);
 724
 725         if (!a->expire_event_source)
 726                 return;
 727
 728         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 729 }
 730
 731 static void automount_enter_running(Automount *a) {
 732         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 733         Unit *trigger;
 734         struct stat st;
 735         int r;
 736
 737         assert(a);
 738
 739         /* If the user masked our unit in the meantime, fail */
 740         if (UNIT(a)->load_state != UNIT_LOADED) {
 741                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 742                 goto fail;
 743         }
 744
 745         /* We don't take mount requests anymore if we are supposed to
 746          * shut down anyway */
 747         if (unit_stop_pending(UNIT(a))) {
 748                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 749                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 750                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 751                 return;
 752         }
 753
 754         mkdir_p_label(a->where, a->directory_mode);
 755
 756         /* Before we do anything, let's see if somebody is playing games with us? */
 757         if (lstat(a->where, &st) < 0) {
 758                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 759                 goto fail;
 760         }
 761
 762         /* The mount unit may have been explicitly started before we got the
 763          * autofs request. Ack it to unblock anything waiting on the mount point. */
 764         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 765                 log_unit_info(UNIT(a), "Automount point already active?");
 766                 automount_send_ready(a, a->tokens, 0);
 767                 return;
 768         }
 769
 770         trigger = UNIT_TRIGGER(UNIT(a));
 771         if (!trigger) {
 772                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 773                 goto fail;
 774         }
 775
 776         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 777         if (r < 0) {
 778                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 779                 goto fail;
 780         }
 781
 782         automount_set_state(a, AUTOMOUNT_RUNNING);
 783         return;
 784
 785 fail:
 786         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 787 }
 788
 789 static int automount_start(Unit *u) {
 790         Automount *a = AUTOMOUNT(u);
 791         Unit *trigger;
 792         int r;
 793
 794         assert(a);
 795         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 796
 797         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 798                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 799                 return -EEXIST;
 800         }
 801
 802         trigger = UNIT_TRIGGER(u);
 803         if (!trigger || trigger->load_state != UNIT_LOADED) {
 804                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 805                 return -ENOENT;
 806         }
 807
 808         r = unit_start_limit_test(u);
 809         if (r < 0) {
 810                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 811                 return r;
 812         }
 813
 814         r = unit_acquire_invocation_id(u);
 815         if (r < 0)
 816                 return r;
 817
 818         a->result = AUTOMOUNT_SUCCESS;
 819         automount_enter_waiting(a);
 820         return 1;
 821 }
 822
 823 static int automount_stop(Unit *u) {
 824         Automount *a = AUTOMOUNT(u);
 825
 826         assert(a);
 827         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 828
 829         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 830         return 1;
 831 }
 832
 833 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 834         Automount *a = AUTOMOUNT(u);
 835         Iterator i;
 836         void *p;
 837         int r;
 838
 839         assert(a);
 840         assert(f);
 841         assert(fds);
 842
 843         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 844         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 845         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 846
 847         SET_FOREACH(p, a->tokens, i)
 848                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 849         SET_FOREACH(p, a->expire_tokens, i)
 850                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 851
 852         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 853         if (r < 0)
 854                 return r;
 855
 856         return 0;
 857 }
 858
 859 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 860         Automount *a = AUTOMOUNT(u);
 861         int r;
 862
 863         assert(a);
 864         assert(fds);
 865
 866         if (streq(key, "state")) {
 867                 AutomountState state;
 868
 869                 state = automount_state_from_string(value);
 870                 if (state < 0)
 871                         log_unit_debug(u, "Failed to parse state value: %s", value);
 872                 else
 873                         a->deserialized_state = state;
 874         } else if (streq(key, "result")) {
 875                 AutomountResult f;
 876
 877                 f = automount_result_from_string(value);
 878                 if (f < 0)
 879                         log_unit_debug(u, "Failed to parse result value: %s", value);
 880                 else if (f != AUTOMOUNT_SUCCESS)
 881                         a->result = f;
 882
 883         } else if (streq(key, "dev-id")) {
 884                 unsigned long d;
 885
 886                 if (safe_atolu(value, &d) < 0)
 887                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 888                 else
 889                         a->dev_id = (dev_t) d;
 890
 891         } else if (streq(key, "token")) {
 892                 unsigned token;
 893
 894                 if (safe_atou(value, &token) < 0)
 895                         log_unit_debug(u, "Failed to parse token value: %s", value);
 896                 else {
 897                         r = set_ensure_allocated(&a->tokens, NULL);
 898                         if (r < 0) {
 899                                 log_oom();
 900                                 return 0;
 901                         }
 902
 903                         r = set_put(a->tokens, UINT_TO_PTR(token));
 904                         if (r < 0)
 905                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 906                 }
 907         } else if (streq(key, "expire-token")) {
 908                 unsigned token;
 909
 910                 if (safe_atou(value, &token) < 0)
 911                         log_unit_debug(u, "Failed to parse token value: %s", value);
 912                 else {
 913                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 914                         if (r < 0) {
 915                                 log_oom();
 916                                 return 0;
 917                         }
 918
 919                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 920                         if (r < 0)
 921                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 922                 }
 923         } else if (streq(key, "pipe-fd")) {
 924                 int fd;
 925
 926                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 927                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 928                 else {
 929                         safe_close(a->pipe_fd);
 930                         a->pipe_fd = fdset_remove(fds, fd);
 931                 }
 932         } else
 933                 log_unit_debug(u, "Unknown serialization key: %s", key);
 934
 935         return 0;
 936 }
 937
 938 static UnitActiveState automount_active_state(Unit *u) {
 939         assert(u);
 940
 941         return state_translation_table[AUTOMOUNT(u)->state];
 942 }
 943
 944 static const char *automount_sub_state_to_string(Unit *u) {
 945         assert(u);
 946
 947         return automount_state_to_string(AUTOMOUNT(u)->state);
 948 }
 949
 950 static bool automount_may_gc(Unit *u) {
 951         Unit *t;
 952
 953         assert(u);
 954
 955         t = UNIT_TRIGGER(u);
 956         if (!t)
 957                 return true;
 958
 959         return UNIT_VTABLE(t)->may_gc(t);
 960 }
 961
 962 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 963         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 964         union autofs_v5_packet_union packet;
 965         Automount *a = AUTOMOUNT(userdata);
 966         Unit *trigger;
 967         int r;
 968
 969         assert(a);
 970         assert(fd == a->pipe_fd);
 971
 972         if (events != EPOLLIN) {
 973                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 974                 goto fail;
 975         }
 976
 977         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 978         if (r < 0) {
 979                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 980                 goto fail;
 981         }
 982
 983         switch (packet.hdr.type) {
 984
 985         case autofs_ptype_missing_direct:
 986
 987                 if (packet.v5_packet.pid > 0) {
 988                         _cleanup_free_ char *p = NULL;
 989
 990                         get_process_comm(packet.v5_packet.pid, &p);
 991                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 992                 } else
 993                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
 994
 995                 r = set_ensure_allocated(&a->tokens, NULL);
 996                 if (r < 0) {
 997                         log_unit_error(UNIT(a), "Failed to allocate token set.");
 998                         goto fail;
 999                 }
1000
1001                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1002                 if (r < 0) {
1003                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1004                         goto fail;
1005                 }
1006
1007                 automount_enter_running(a);
1008                 break;
1009
1010         case autofs_ptype_expire_direct:
1011                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1012
1013                 automount_stop_expire(a);
1014
1015                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1016                 if (r < 0) {
1017                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1018                         goto fail;
1019                 }
1020
1021                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1022                 if (r < 0) {
1023                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1024                         goto fail;
1025                 }
1026
1027                 trigger = UNIT_TRIGGER(UNIT(a));
1028                 if (!trigger) {
1029                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1030                         goto fail;
1031                 }
1032
1033                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1034                 if (r < 0) {
1035                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1036                         goto fail;
1037                 }
1038                 break;
1039
1040         default:
1041                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1042                 break;
1043         }
1044
1045         return 0;
1046
1047 fail:
1048         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1049         return 0;
1050 }
1051
1052 static void automount_shutdown(Manager *m) {
1053         assert(m);
1054
1055         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1056 }
1057
1058 static void automount_reset_failed(Unit *u) {
1059         Automount *a = AUTOMOUNT(u);
1060
1061         assert(a);
1062
1063         if (a->state == AUTOMOUNT_FAILED)
1064                 automount_set_state(a, AUTOMOUNT_DEAD);
1065
1066         a->result = AUTOMOUNT_SUCCESS;
1067 }
1068
1069 static bool automount_supported(void) {
1070         static int supported = -1;
1071
1072         if (supported < 0)
1073                 supported = access("/dev/autofs", F_OK) >= 0;
1074
1075         return supported;
1076 }
1077
1078 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1079         [AUTOMOUNT_SUCCESS] = "success",
1080         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1081         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1082         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1083 };
1084
1085 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1086
1087 const UnitVTable automount_vtable = {
1088         .object_size = sizeof(Automount),
1089
1090         .sections =
1091                 "Unit\0"
1092                 "Automount\0"
1093                 "Install\0",
1094
1095         .init = automount_init,
1096         .load = automount_load,
1097         .done = automount_done,
1098
1099         .coldplug = automount_coldplug,
1100
1101         .dump = automount_dump,
1102
1103         .start = automount_start,
1104         .stop = automount_stop,
1105
1106         .serialize = automount_serialize,
1107         .deserialize_item = automount_deserialize_item,
1108
1109         .active_state = automount_active_state,
1110         .sub_state_to_string = automount_sub_state_to_string,
1111
1112         .may_gc = automount_may_gc,
1113
1114         .trigger_notify = automount_trigger_notify,
1115
1116         .reset_failed = automount_reset_failed,
1117
1118         .bus_vtable = bus_automount_vtable,
1119         .bus_set_property = bus_automount_set_property,
1120
1121         .can_transient = true,
1122
1123         .shutdown = automount_shutdown,
1124         .supported = automount_supported,
1125
1126         .status_message_formats = {
1127                 .finished_start_job = {
1128                         [JOB_DONE]       = "Set up automount %s.",
1129                         [JOB_FAILED]     = "Failed to set up automount %s.",
1130                 },
1131                 .finished_stop_job = {
1132                         [JOB_DONE]       = "Unset automount %s.",
1133                         [JOB_FAILED]     = "Failed to unset automount %s.",
1134                 },
1135         },
1136 };