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 "dbus-unit.h"
  20 #include "fd-util.h"
  21 #include "format-util.h"
  22 #include "io-util.h"
  23 #include "label.h"
  24 #include "mkdir.h"
  25 #include "mount-util.h"
  26 #include "mount.h"
  27 #include "mountpoint-util.h"
  28 #include "parse-util.h"
  29 #include "path-util.h"
  30 #include "process-util.h"
  31 #include "serialize.h"
  32 #include "special.h"
  33 #include "stdio-util.h"
  34 #include "string-table.h"
  35 #include "string-util.h"
  36 #include "unit-name.h"
  37 #include "unit.h"
  38
  39 static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
  40         [AUTOMOUNT_DEAD] = UNIT_INACTIVE,
  41         [AUTOMOUNT_WAITING] = UNIT_ACTIVE,
  42         [AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
  43         [AUTOMOUNT_FAILED] = UNIT_FAILED
  44 };
  45
  46 struct expire_data {
  47         int dev_autofs_fd;
  48         int ioctl_fd;
  49 };
  50
  51 static void expire_data_free(struct expire_data *data) {
  52         if (!data)
  53                 return;
  54
  55         safe_close(data->dev_autofs_fd);
  56         safe_close(data->ioctl_fd);
  57         free(data);
  58 }
  59
  60 DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
  61
  62 static int open_dev_autofs(Manager *m);
  63 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  64 static int automount_start_expire(Automount *a);
  65 static void automount_stop_expire(Automount *a);
  66 static int automount_send_ready(Automount *a, Set *tokens, int status);
  67
  68 static void automount_init(Unit *u) {
  69         Automount *a = AUTOMOUNT(u);
  70
  71         assert(u);
  72         assert(u->load_state == UNIT_STUB);
  73
  74         a->pipe_fd = -1;
  75         a->directory_mode = 0755;
  76         UNIT(a)->ignore_on_isolate = true;
  77 }
  78
  79 static void unmount_autofs(Automount *a) {
  80         int r;
  81
  82         assert(a);
  83
  84         if (a->pipe_fd < 0)
  85                 return;
  86
  87         a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
  88         a->pipe_fd = safe_close(a->pipe_fd);
  89
  90         /* If we reload/reexecute things we keep the mount point around */
  91         if (!IN_SET(UNIT(a)->manager->objective, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
  92
  93                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
  94                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
  95
  96                 if (a->where) {
  97                         r = repeat_unmount(a->where, MNT_DETACH);
  98                         if (r < 0)
  99                                 log_error_errno(r, "Failed to unmount: %m");
 100                 }
 101         }
 102 }
 103
 104 static void automount_done(Unit *u) {
 105         Automount *a = AUTOMOUNT(u);
 106
 107         assert(a);
 108
 109         unmount_autofs(a);
 110
 111         a->where = mfree(a->where);
 112
 113         a->tokens = set_free(a->tokens);
 114         a->expire_tokens = set_free(a->expire_tokens);
 115
 116         a->expire_event_source = sd_event_source_unref(a->expire_event_source);
 117 }
 118
 119 static int automount_add_trigger_dependencies(Automount *a) {
 120         Unit *x;
 121         int r;
 122
 123         assert(a);
 124
 125         r = unit_load_related_unit(UNIT(a), ".mount", &x);
 126         if (r < 0)
 127                 return r;
 128
 129         return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 130 }
 131
 132 static int automount_add_mount_dependencies(Automount *a) {
 133         _cleanup_free_ char *parent = NULL;
 134
 135         assert(a);
 136
 137         parent = dirname_malloc(a->where);
 138         if (!parent)
 139                 return -ENOMEM;
 140
 141         return unit_require_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT);
 142 }
 143
 144 static int automount_add_default_dependencies(Automount *a) {
 145         int r;
 146
 147         assert(a);
 148
 149         if (!UNIT(a)->default_dependencies)
 150                 return 0;
 151
 152         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 153                 return 0;
 154
 155         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 156         if (r < 0)
 157                 return r;
 158
 159         return 0;
 160 }
 161
 162 static int automount_verify(Automount *a) {
 163         _cleanup_free_ char *e = NULL;
 164         int r;
 165
 166         assert(a);
 167
 168         if (UNIT(a)->load_state != UNIT_LOADED)
 169                 return 0;
 170
 171         if (path_equal(a->where, "/")) {
 172                 log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing.");
 173                 return -ENOEXEC;
 174         }
 175
 176         r = unit_name_from_path(a->where, ".automount", &e);
 177         if (r < 0)
 178                 return log_unit_error_errno(UNIT(a), r, "Failed to generate unit name from path: %m");
 179
 180         if (!unit_has_name(UNIT(a), e)) {
 181                 log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing.");
 182                 return -ENOEXEC;
 183         }
 184
 185         return 0;
 186 }
 187
 188 static int automount_set_where(Automount *a) {
 189         int r;
 190
 191         assert(a);
 192
 193         if (a->where)
 194                 return 0;
 195
 196         r = unit_name_to_path(UNIT(a)->id, &a->where);
 197         if (r < 0)
 198                 return r;
 199
 200         path_simplify(a->where, false);
 201         return 1;
 202 }
 203
 204 static int automount_load(Unit *u) {
 205         Automount *a = AUTOMOUNT(u);
 206         int r;
 207
 208         assert(u);
 209         assert(u->load_state == UNIT_STUB);
 210
 211         /* Load a .automount file */
 212         r = unit_load_fragment_and_dropin(u);
 213         if (r < 0)
 214                 return r;
 215
 216         if (u->load_state == UNIT_LOADED) {
 217                 r = automount_set_where(a);
 218                 if (r < 0)
 219                         return r;
 220
 221                 r = automount_add_trigger_dependencies(a);
 222                 if (r < 0)
 223                         return r;
 224
 225                 r = automount_add_mount_dependencies(a);
 226                 if (r < 0)
 227                         return r;
 228
 229                 r = automount_add_default_dependencies(a);
 230                 if (r < 0)
 231                         return r;
 232         }
 233
 234         return automount_verify(a);
 235 }
 236
 237 static void automount_set_state(Automount *a, AutomountState state) {
 238         AutomountState old_state;
 239         assert(a);
 240
 241         if (a->state != state)
 242                 bus_unit_send_pending_change_signal(UNIT(a), false);
 243
 244         old_state = a->state;
 245         a->state = state;
 246
 247         if (state != AUTOMOUNT_RUNNING)
 248                 automount_stop_expire(a);
 249
 250         if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 251                 unmount_autofs(a);
 252
 253         if (state != old_state)
 254                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 255
 256         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], 0);
 257 }
 258
 259 static int automount_coldplug(Unit *u) {
 260         Automount *a = AUTOMOUNT(u);
 261         int r;
 262
 263         assert(a);
 264         assert(a->state == AUTOMOUNT_DEAD);
 265
 266         if (a->deserialized_state == a->state)
 267                 return 0;
 268
 269         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 270
 271                 r = automount_set_where(a);
 272                 if (r < 0)
 273                         return r;
 274
 275                 r = open_dev_autofs(u->manager);
 276                 if (r < 0)
 277                         return r;
 278
 279                 assert(a->pipe_fd >= 0);
 280
 281                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 282                 if (r < 0)
 283                         return r;
 284
 285                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 286                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 287                         r = automount_start_expire(a);
 288                         if (r < 0)
 289                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 290                 }
 291
 292                 automount_set_state(a, a->deserialized_state);
 293         }
 294
 295         return 0;
 296 }
 297
 298 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 299         char time_string[FORMAT_TIMESPAN_MAX];
 300         Automount *a = AUTOMOUNT(u);
 301
 302         assert(a);
 303
 304         fprintf(f,
 305                 "%sAutomount State: %s\n"
 306                 "%sResult: %s\n"
 307                 "%sWhere: %s\n"
 308                 "%sDirectoryMode: %04o\n"
 309                 "%sTimeoutIdleUSec: %s\n",
 310                 prefix, automount_state_to_string(a->state),
 311                 prefix, automount_result_to_string(a->result),
 312                 prefix, a->where,
 313                 prefix, a->directory_mode,
 314                 prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
 315 }
 316
 317 static void automount_enter_dead(Automount *a, AutomountResult f) {
 318         assert(a);
 319
 320         if (a->result == AUTOMOUNT_SUCCESS)
 321                 a->result = f;
 322
 323         unit_log_result(UNIT(a), a->result == AUTOMOUNT_SUCCESS, automount_result_to_string(a->result));
 324         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 325 }
 326
 327 static int open_dev_autofs(Manager *m) {
 328         struct autofs_dev_ioctl param;
 329
 330         assert(m);
 331
 332         if (m->dev_autofs_fd >= 0)
 333                 return m->dev_autofs_fd;
 334
 335         (void) label_fix("/dev/autofs", 0);
 336
 337         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 338         if (m->dev_autofs_fd < 0)
 339                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 340
 341         init_autofs_dev_ioctl(&param);
 342         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 343                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 344                 return -errno;
 345         }
 346
 347         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 348
 349         return m->dev_autofs_fd;
 350 }
 351
 352 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 353         struct autofs_dev_ioctl *param;
 354         size_t l;
 355
 356         assert(dev_autofs_fd >= 0);
 357         assert(where);
 358
 359         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 360         param = alloca(l);
 361
 362         init_autofs_dev_ioctl(param);
 363         param->size = l;
 364         param->ioctlfd = -1;
 365         param->openmount.devid = devid;
 366         strcpy(param->path, where);
 367
 368         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 369                 return -errno;
 370
 371         if (param->ioctlfd < 0)
 372                 return -EIO;
 373
 374         (void) fd_cloexec(param->ioctlfd, true);
 375         return param->ioctlfd;
 376 }
 377
 378 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 379         uint32_t major, minor;
 380         struct autofs_dev_ioctl param;
 381
 382         assert(dev_autofs_fd >= 0);
 383         assert(ioctl_fd >= 0);
 384
 385         init_autofs_dev_ioctl(&param);
 386         param.ioctlfd = ioctl_fd;
 387
 388         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 389                 return -errno;
 390
 391         major = param.protover.version;
 392
 393         init_autofs_dev_ioctl(&param);
 394         param.ioctlfd = ioctl_fd;
 395
 396         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 397                 return -errno;
 398
 399         minor = param.protosubver.sub_version;
 400
 401         log_debug("Autofs protocol version %i.%i", major, minor);
 402         return 0;
 403 }
 404
 405 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 406         struct autofs_dev_ioctl param;
 407
 408         assert(dev_autofs_fd >= 0);
 409         assert(ioctl_fd >= 0);
 410
 411         init_autofs_dev_ioctl(&param);
 412         param.ioctlfd = ioctl_fd;
 413
 414         if (usec == USEC_INFINITY)
 415                 param.timeout.timeout = 0;
 416         else
 417                 /* Convert to seconds, rounding up. */
 418                 param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
 419
 420         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 421                 return -errno;
 422
 423         return 0;
 424 }
 425
 426 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 427         struct autofs_dev_ioctl param;
 428
 429         assert(dev_autofs_fd >= 0);
 430         assert(ioctl_fd >= 0);
 431
 432         init_autofs_dev_ioctl(&param);
 433         param.ioctlfd = ioctl_fd;
 434
 435         if (status != 0) {
 436                 param.fail.token = token;
 437                 param.fail.status = status;
 438         } else
 439                 param.ready.token = token;
 440
 441         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 442                 return -errno;
 443
 444         return 0;
 445 }
 446
 447 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 448         _cleanup_close_ int ioctl_fd = -1;
 449         unsigned token;
 450         int r;
 451
 452         assert(a);
 453         assert(status <= 0);
 454
 455         if (set_isempty(tokens))
 456                 return 0;
 457
 458         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 459         if (ioctl_fd < 0)
 460                 return ioctl_fd;
 461
 462         if (status != 0)
 463                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 464         else
 465                 log_unit_debug(UNIT(a), "Sending success.");
 466
 467         r = 0;
 468
 469         /* Autofs thankfully does not hand out 0 as a token */
 470         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 471                 int k;
 472
 473                 /* Autofs fun fact:
 474                  *
 475                  * if you pass a positive status code here, kernels
 476                  * prior to 4.12 will freeze! Yay! */
 477
 478                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 479                                       ioctl_fd,
 480                                       token,
 481                                       status);
 482                 if (k < 0)
 483                         r = k;
 484         }
 485
 486         return r;
 487 }
 488
 489 static void automount_trigger_notify(Unit *u, Unit *other) {
 490         Automount *a = AUTOMOUNT(u);
 491         int r;
 492
 493         assert(a);
 494         assert(other);
 495
 496         /* Filter out invocations with bogus state */
 497         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 498                 return;
 499
 500         /* Don't propagate state changes from the mount if we are already down */
 501         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 502                 return;
 503
 504         /* Propagate start limit hit state */
 505         if (other->start_limit_hit) {
 506                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 507                 return;
 508         }
 509
 510         /* Don't propagate anything if there's still a job queued */
 511         if (other->job)
 512                 return;
 513
 514         /* The mount is successfully established */
 515         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 516                 (void) automount_send_ready(a, a->tokens, 0);
 517
 518                 r = automount_start_expire(a);
 519                 if (r < 0)
 520                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 521
 522                 automount_set_state(a, AUTOMOUNT_RUNNING);
 523         }
 524
 525         if (IN_SET(MOUNT(other)->state,
 526                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 527                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 528                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 529                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 530                    MOUNT_FAILED)) {
 531
 532                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 533         }
 534
 535         if (MOUNT(other)->state == MOUNT_DEAD)
 536                 (void) automount_send_ready(a, a->expire_tokens, 0);
 537
 538         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 539         if (IN_SET(MOUNT(other)->state,
 540                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 541                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 542                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 543                    MOUNT_FAILED)) {
 544
 545                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 546
 547                 automount_set_state(a, AUTOMOUNT_WAITING);
 548         }
 549 }
 550
 551 static void automount_enter_waiting(Automount *a) {
 552         _cleanup_close_ int ioctl_fd = -1;
 553         int p[2] = { -1, -1 };
 554         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 555         char options[STRLEN("fd=,pgrp=,minproto=5,maxproto=5,direct")
 556                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 557         bool mounted = false;
 558         int r, dev_autofs_fd;
 559         struct stat st;
 560
 561         assert(a);
 562         assert(a->pipe_fd < 0);
 563         assert(a->where);
 564
 565         set_clear(a->tokens);
 566
 567         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 568         if (r < 0)
 569                 goto fail;
 570
 571         (void) mkdir_p_label(a->where, 0555);
 572
 573         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 574
 575         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 576         if (dev_autofs_fd < 0) {
 577                 r = dev_autofs_fd;
 578                 goto fail;
 579         }
 580
 581         if (pipe2(p, O_CLOEXEC) < 0) {
 582                 r = -errno;
 583                 goto fail;
 584         }
 585         r = fd_nonblock(p[0], true);
 586         if (r < 0)
 587                 goto fail;
 588
 589         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 590         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 591         if (mount(name, a->where, "autofs", 0, options) < 0) {
 592                 r = -errno;
 593                 goto fail;
 594         }
 595
 596         mounted = true;
 597
 598         p[1] = safe_close(p[1]);
 599
 600         if (stat(a->where, &st) < 0) {
 601                 r = -errno;
 602                 goto fail;
 603         }
 604
 605         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 606         if (ioctl_fd < 0) {
 607                 r = ioctl_fd;
 608                 goto fail;
 609         }
 610
 611         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 612         if (r < 0)
 613                 goto fail;
 614
 615         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 616         if (r < 0)
 617                 goto fail;
 618
 619         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 620         if (r < 0)
 621                 goto fail;
 622
 623         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 624
 625         a->pipe_fd = p[0];
 626         a->dev_id = st.st_dev;
 627
 628         automount_set_state(a, AUTOMOUNT_WAITING);
 629
 630         return;
 631
 632 fail:
 633         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 634
 635         safe_close_pair(p);
 636
 637         if (mounted) {
 638                 r = repeat_unmount(a->where, MNT_DETACH);
 639                 if (r < 0)
 640                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 641         }
 642
 643         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 644 }
 645
 646 static void *expire_thread(void *p) {
 647         struct autofs_dev_ioctl param;
 648         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 649         int r;
 650
 651         assert(data->dev_autofs_fd >= 0);
 652         assert(data->ioctl_fd >= 0);
 653
 654         init_autofs_dev_ioctl(&param);
 655         param.ioctlfd = data->ioctl_fd;
 656
 657         do {
 658                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 659         } while (r >= 0);
 660
 661         if (errno != EAGAIN)
 662                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 663
 664         return NULL;
 665 }
 666
 667 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 668         Automount *a = AUTOMOUNT(userdata);
 669         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 670         int r;
 671
 672         assert(a);
 673         assert(source == a->expire_event_source);
 674
 675         data = new0(struct expire_data, 1);
 676         if (!data)
 677                 return log_oom();
 678
 679         data->ioctl_fd = -1;
 680
 681         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 682         if (data->dev_autofs_fd < 0)
 683                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 684
 685         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 686         if (data->ioctl_fd < 0)
 687                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 688
 689         r = asynchronous_job(expire_thread, data);
 690         if (r < 0)
 691                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 692
 693         data = NULL;
 694
 695         return automount_start_expire(a);
 696 }
 697
 698 static int automount_start_expire(Automount *a) {
 699         int r;
 700         usec_t timeout;
 701
 702         assert(a);
 703
 704         if (a->timeout_idle_usec == 0)
 705                 return 0;
 706
 707         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 708
 709         if (a->expire_event_source) {
 710                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 711                 if (r < 0)
 712                         return r;
 713
 714                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 715         }
 716
 717         r = sd_event_add_time(
 718                         UNIT(a)->manager->event,
 719                         &a->expire_event_source,
 720                         CLOCK_MONOTONIC, timeout, 0,
 721                         automount_dispatch_expire, a);
 722         if (r < 0)
 723                 return r;
 724
 725         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 726
 727         return 0;
 728 }
 729
 730 static void automount_stop_expire(Automount *a) {
 731         assert(a);
 732
 733         if (!a->expire_event_source)
 734                 return;
 735
 736         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 737 }
 738
 739 static void automount_enter_running(Automount *a) {
 740         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 741         Unit *trigger;
 742         struct stat st;
 743         int r;
 744
 745         assert(a);
 746
 747         /* If the user masked our unit in the meantime, fail */
 748         if (UNIT(a)->load_state != UNIT_LOADED) {
 749                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 750                 goto fail;
 751         }
 752
 753         /* We don't take mount requests anymore if we are supposed to
 754          * shut down anyway */
 755         if (unit_stop_pending(UNIT(a))) {
 756                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 757                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 758                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 759                 return;
 760         }
 761
 762         mkdir_p_label(a->where, a->directory_mode);
 763
 764         /* Before we do anything, let's see if somebody is playing games with us? */
 765         if (lstat(a->where, &st) < 0) {
 766                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 767                 goto fail;
 768         }
 769
 770         /* The mount unit may have been explicitly started before we got the
 771          * autofs request. Ack it to unblock anything waiting on the mount point. */
 772         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 773                 log_unit_info(UNIT(a), "Automount point already active?");
 774                 automount_send_ready(a, a->tokens, 0);
 775                 return;
 776         }
 777
 778         trigger = UNIT_TRIGGER(UNIT(a));
 779         if (!trigger) {
 780                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 781                 goto fail;
 782         }
 783
 784         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 785         if (r < 0) {
 786                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 787                 goto fail;
 788         }
 789
 790         automount_set_state(a, AUTOMOUNT_RUNNING);
 791         return;
 792
 793 fail:
 794         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 795 }
 796
 797 static int automount_start(Unit *u) {
 798         Automount *a = AUTOMOUNT(u);
 799         Unit *trigger;
 800         int r;
 801
 802         assert(a);
 803         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 804
 805         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 806                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 807                 return -EEXIST;
 808         }
 809
 810         trigger = UNIT_TRIGGER(u);
 811         if (!trigger || trigger->load_state != UNIT_LOADED) {
 812                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 813                 return -ENOENT;
 814         }
 815
 816         r = unit_start_limit_test(u);
 817         if (r < 0) {
 818                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 819                 return r;
 820         }
 821
 822         r = unit_acquire_invocation_id(u);
 823         if (r < 0)
 824                 return r;
 825
 826         a->result = AUTOMOUNT_SUCCESS;
 827         automount_enter_waiting(a);
 828         return 1;
 829 }
 830
 831 static int automount_stop(Unit *u) {
 832         Automount *a = AUTOMOUNT(u);
 833
 834         assert(a);
 835         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 836
 837         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 838         return 1;
 839 }
 840
 841 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 842         Automount *a = AUTOMOUNT(u);
 843         Iterator i;
 844         void *p;
 845         int r;
 846
 847         assert(a);
 848         assert(f);
 849         assert(fds);
 850
 851         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 852         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 853         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 854
 855         SET_FOREACH(p, a->tokens, i)
 856                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 857         SET_FOREACH(p, a->expire_tokens, i)
 858                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 859
 860         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 861         if (r < 0)
 862                 return r;
 863
 864         return 0;
 865 }
 866
 867 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 868         Automount *a = AUTOMOUNT(u);
 869         int r;
 870
 871         assert(a);
 872         assert(fds);
 873
 874         if (streq(key, "state")) {
 875                 AutomountState state;
 876
 877                 state = automount_state_from_string(value);
 878                 if (state < 0)
 879                         log_unit_debug(u, "Failed to parse state value: %s", value);
 880                 else
 881                         a->deserialized_state = state;
 882         } else if (streq(key, "result")) {
 883                 AutomountResult f;
 884
 885                 f = automount_result_from_string(value);
 886                 if (f < 0)
 887                         log_unit_debug(u, "Failed to parse result value: %s", value);
 888                 else if (f != AUTOMOUNT_SUCCESS)
 889                         a->result = f;
 890
 891         } else if (streq(key, "dev-id")) {
 892                 unsigned long d;
 893
 894                 if (safe_atolu(value, &d) < 0)
 895                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 896                 else
 897                         a->dev_id = (dev_t) d;
 898
 899         } else if (streq(key, "token")) {
 900                 unsigned token;
 901
 902                 if (safe_atou(value, &token) < 0)
 903                         log_unit_debug(u, "Failed to parse token value: %s", value);
 904                 else {
 905                         r = set_ensure_allocated(&a->tokens, NULL);
 906                         if (r < 0) {
 907                                 log_oom();
 908                                 return 0;
 909                         }
 910
 911                         r = set_put(a->tokens, UINT_TO_PTR(token));
 912                         if (r < 0)
 913                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 914                 }
 915         } else if (streq(key, "expire-token")) {
 916                 unsigned token;
 917
 918                 if (safe_atou(value, &token) < 0)
 919                         log_unit_debug(u, "Failed to parse token value: %s", value);
 920                 else {
 921                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 922                         if (r < 0) {
 923                                 log_oom();
 924                                 return 0;
 925                         }
 926
 927                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 928                         if (r < 0)
 929                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 930                 }
 931         } else if (streq(key, "pipe-fd")) {
 932                 int fd;
 933
 934                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 935                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 936                 else {
 937                         safe_close(a->pipe_fd);
 938                         a->pipe_fd = fdset_remove(fds, fd);
 939                 }
 940         } else
 941                 log_unit_debug(u, "Unknown serialization key: %s", key);
 942
 943         return 0;
 944 }
 945
 946 static UnitActiveState automount_active_state(Unit *u) {
 947         assert(u);
 948
 949         return state_translation_table[AUTOMOUNT(u)->state];
 950 }
 951
 952 static const char *automount_sub_state_to_string(Unit *u) {
 953         assert(u);
 954
 955         return automount_state_to_string(AUTOMOUNT(u)->state);
 956 }
 957
 958 static bool automount_may_gc(Unit *u) {
 959         Unit *t;
 960
 961         assert(u);
 962
 963         t = UNIT_TRIGGER(u);
 964         if (!t)
 965                 return true;
 966
 967         return UNIT_VTABLE(t)->may_gc(t);
 968 }
 969
 970 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 971         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 972         union autofs_v5_packet_union packet;
 973         Automount *a = AUTOMOUNT(userdata);
 974         Unit *trigger;
 975         int r;
 976
 977         assert(a);
 978         assert(fd == a->pipe_fd);
 979
 980         if (events != EPOLLIN) {
 981                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 982                 goto fail;
 983         }
 984
 985         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 986         if (r < 0) {
 987                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 988                 goto fail;
 989         }
 990
 991         switch (packet.hdr.type) {
 992
 993         case autofs_ptype_missing_direct:
 994
 995                 if (packet.v5_packet.pid > 0) {
 996                         _cleanup_free_ char *p = NULL;
 997
 998                         get_process_comm(packet.v5_packet.pid, &p);
 999                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
1000                 } else
1001                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
1002
1003                 r = set_ensure_allocated(&a->tokens, NULL);
1004                 if (r < 0) {
1005                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1006                         goto fail;
1007                 }
1008
1009                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1010                 if (r < 0) {
1011                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1012                         goto fail;
1013                 }
1014
1015                 automount_enter_running(a);
1016                 break;
1017
1018         case autofs_ptype_expire_direct:
1019                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1020
1021                 automount_stop_expire(a);
1022
1023                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1024                 if (r < 0) {
1025                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1026                         goto fail;
1027                 }
1028
1029                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1030                 if (r < 0) {
1031                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1032                         goto fail;
1033                 }
1034
1035                 trigger = UNIT_TRIGGER(UNIT(a));
1036                 if (!trigger) {
1037                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1038                         goto fail;
1039                 }
1040
1041                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1042                 if (r < 0) {
1043                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1044                         goto fail;
1045                 }
1046                 break;
1047
1048         default:
1049                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1050                 break;
1051         }
1052
1053         return 0;
1054
1055 fail:
1056         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1057         return 0;
1058 }
1059
1060 static void automount_shutdown(Manager *m) {
1061         assert(m);
1062
1063         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1064 }
1065
1066 static void automount_reset_failed(Unit *u) {
1067         Automount *a = AUTOMOUNT(u);
1068
1069         assert(a);
1070
1071         if (a->state == AUTOMOUNT_FAILED)
1072                 automount_set_state(a, AUTOMOUNT_DEAD);
1073
1074         a->result = AUTOMOUNT_SUCCESS;
1075 }
1076
1077 static bool automount_supported(void) {
1078         static int supported = -1;
1079
1080         if (supported < 0)
1081                 supported = access("/dev/autofs", F_OK) >= 0;
1082
1083         return supported;
1084 }
1085
1086 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1087         [AUTOMOUNT_SUCCESS] = "success",
1088         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1089         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1090         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1091 };
1092
1093 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1094
1095 const UnitVTable automount_vtable = {
1096         .object_size = sizeof(Automount),
1097
1098         .sections =
1099                 "Unit\0"
1100                 "Automount\0"
1101                 "Install\0",
1102
1103         .init = automount_init,
1104         .load = automount_load,
1105         .done = automount_done,
1106
1107         .coldplug = automount_coldplug,
1108
1109         .dump = automount_dump,
1110
1111         .start = automount_start,
1112         .stop = automount_stop,
1113
1114         .serialize = automount_serialize,
1115         .deserialize_item = automount_deserialize_item,
1116
1117         .active_state = automount_active_state,
1118         .sub_state_to_string = automount_sub_state_to_string,
1119
1120         .may_gc = automount_may_gc,
1121
1122         .trigger_notify = automount_trigger_notify,
1123
1124         .reset_failed = automount_reset_failed,
1125
1126         .bus_vtable = bus_automount_vtable,
1127         .bus_set_property = bus_automount_set_property,
1128
1129         .can_transient = true,
1130
1131         .shutdown = automount_shutdown,
1132         .supported = automount_supported,
1133
1134         .status_message_formats = {
1135                 .finished_start_job = {
1136                         [JOB_DONE]       = "Set up automount %s.",
1137                         [JOB_FAILED]     = "Failed to set up automount %s.",
1138                 },
1139                 .finished_stop_job = {
1140                         [JOB_DONE]       = "Unset automount %s.",
1141                         [JOB_FAILED]     = "Failed to unset automount %s.",
1142                 },
1143         },
1144 };