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         if (a->result == AUTOMOUNT_SUCCESS)
 319                 unit_log_success(UNIT(a));
 320         else
 321                 unit_log_failure(UNIT(a), automount_result_to_string(a->result));
 322
 323         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 324 }
 325
 326 static int open_dev_autofs(Manager *m) {
 327         struct autofs_dev_ioctl param;
 328
 329         assert(m);
 330
 331         if (m->dev_autofs_fd >= 0)
 332                 return m->dev_autofs_fd;
 333
 334         (void) label_fix("/dev/autofs", 0);
 335
 336         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 337         if (m->dev_autofs_fd < 0)
 338                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 339
 340         init_autofs_dev_ioctl(&param);
 341         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 342                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 343                 return -errno;
 344         }
 345
 346         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 347
 348         return m->dev_autofs_fd;
 349 }
 350
 351 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 352         struct autofs_dev_ioctl *param;
 353         size_t l;
 354
 355         assert(dev_autofs_fd >= 0);
 356         assert(where);
 357
 358         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 359         param = alloca(l);
 360
 361         init_autofs_dev_ioctl(param);
 362         param->size = l;
 363         param->ioctlfd = -1;
 364         param->openmount.devid = devid;
 365         strcpy(param->path, where);
 366
 367         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 368                 return -errno;
 369
 370         if (param->ioctlfd < 0)
 371                 return -EIO;
 372
 373         (void) fd_cloexec(param->ioctlfd, true);
 374         return param->ioctlfd;
 375 }
 376
 377 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 378         uint32_t major, minor;
 379         struct autofs_dev_ioctl param;
 380
 381         assert(dev_autofs_fd >= 0);
 382         assert(ioctl_fd >= 0);
 383
 384         init_autofs_dev_ioctl(&param);
 385         param.ioctlfd = ioctl_fd;
 386
 387         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 388                 return -errno;
 389
 390         major = param.protover.version;
 391
 392         init_autofs_dev_ioctl(&param);
 393         param.ioctlfd = ioctl_fd;
 394
 395         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 396                 return -errno;
 397
 398         minor = param.protosubver.sub_version;
 399
 400         log_debug("Autofs protocol version %i.%i", major, minor);
 401         return 0;
 402 }
 403
 404 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 405         struct autofs_dev_ioctl param;
 406
 407         assert(dev_autofs_fd >= 0);
 408         assert(ioctl_fd >= 0);
 409
 410         init_autofs_dev_ioctl(&param);
 411         param.ioctlfd = ioctl_fd;
 412
 413         if (usec == USEC_INFINITY)
 414                 param.timeout.timeout = 0;
 415         else
 416                 /* Convert to seconds, rounding up. */
 417                 param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
 418
 419         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 420                 return -errno;
 421
 422         return 0;
 423 }
 424
 425 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 426         struct autofs_dev_ioctl param;
 427
 428         assert(dev_autofs_fd >= 0);
 429         assert(ioctl_fd >= 0);
 430
 431         init_autofs_dev_ioctl(&param);
 432         param.ioctlfd = ioctl_fd;
 433
 434         if (status != 0) {
 435                 param.fail.token = token;
 436                 param.fail.status = status;
 437         } else
 438                 param.ready.token = token;
 439
 440         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 441                 return -errno;
 442
 443         return 0;
 444 }
 445
 446 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 447         _cleanup_close_ int ioctl_fd = -1;
 448         unsigned token;
 449         int r;
 450
 451         assert(a);
 452         assert(status <= 0);
 453
 454         if (set_isempty(tokens))
 455                 return 0;
 456
 457         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 458         if (ioctl_fd < 0)
 459                 return ioctl_fd;
 460
 461         if (status != 0)
 462                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 463         else
 464                 log_unit_debug(UNIT(a), "Sending success.");
 465
 466         r = 0;
 467
 468         /* Autofs thankfully does not hand out 0 as a token */
 469         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 470                 int k;
 471
 472                 /* Autofs fun fact:
 473                  *
 474                  * if you pass a positive status code here, kernels
 475                  * prior to 4.12 will freeze! Yay! */
 476
 477                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 478                                       ioctl_fd,
 479                                       token,
 480                                       status);
 481                 if (k < 0)
 482                         r = k;
 483         }
 484
 485         return r;
 486 }
 487
 488 static void automount_trigger_notify(Unit *u, Unit *other) {
 489         Automount *a = AUTOMOUNT(u);
 490         int r;
 491
 492         assert(a);
 493         assert(other);
 494
 495         /* Filter out invocations with bogus state */
 496         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 497                 return;
 498
 499         /* Don't propagate state changes from the mount if we are already down */
 500         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 501                 return;
 502
 503         /* Propagate start limit hit state */
 504         if (other->start_limit_hit) {
 505                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 506                 return;
 507         }
 508
 509         /* Don't propagate anything if there's still a job queued */
 510         if (other->job)
 511                 return;
 512
 513         /* The mount is successfully established */
 514         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 515                 (void) automount_send_ready(a, a->tokens, 0);
 516
 517                 r = automount_start_expire(a);
 518                 if (r < 0)
 519                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 520
 521                 automount_set_state(a, AUTOMOUNT_RUNNING);
 522         }
 523
 524         if (IN_SET(MOUNT(other)->state,
 525                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 526                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 527                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 528                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 529                    MOUNT_FAILED)) {
 530
 531                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 532         }
 533
 534         if (MOUNT(other)->state == MOUNT_DEAD)
 535                 (void) automount_send_ready(a, a->expire_tokens, 0);
 536
 537         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 538         if (IN_SET(MOUNT(other)->state,
 539                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 540                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 541                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 542                    MOUNT_FAILED)) {
 543
 544                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 545
 546                 automount_set_state(a, AUTOMOUNT_WAITING);
 547         }
 548 }
 549
 550 static void automount_enter_waiting(Automount *a) {
 551         _cleanup_close_ int ioctl_fd = -1;
 552         int p[2] = { -1, -1 };
 553         char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
 554         char options[STRLEN("fd=,pgrp=,minproto=5,maxproto=5,direct")
 555                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 556         bool mounted = false;
 557         int r, dev_autofs_fd;
 558         struct stat st;
 559
 560         assert(a);
 561         assert(a->pipe_fd < 0);
 562         assert(a->where);
 563
 564         set_clear(a->tokens);
 565
 566         r = unit_fail_if_noncanonical(UNIT(a), a->where);
 567         if (r < 0)
 568                 goto fail;
 569
 570         (void) mkdir_p_label(a->where, 0555);
 571
 572         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 573
 574         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 575         if (dev_autofs_fd < 0) {
 576                 r = dev_autofs_fd;
 577                 goto fail;
 578         }
 579
 580         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 581                 r = -errno;
 582                 goto fail;
 583         }
 584
 585         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 586         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 587         if (mount(name, a->where, "autofs", 0, options) < 0) {
 588                 r = -errno;
 589                 goto fail;
 590         }
 591
 592         mounted = true;
 593
 594         p[1] = safe_close(p[1]);
 595
 596         if (stat(a->where, &st) < 0) {
 597                 r = -errno;
 598                 goto fail;
 599         }
 600
 601         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 602         if (ioctl_fd < 0) {
 603                 r = ioctl_fd;
 604                 goto fail;
 605         }
 606
 607         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 608         if (r < 0)
 609                 goto fail;
 610
 611         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 612         if (r < 0)
 613                 goto fail;
 614
 615         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 616         if (r < 0)
 617                 goto fail;
 618
 619         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 620
 621         a->pipe_fd = p[0];
 622         a->dev_id = st.st_dev;
 623
 624         automount_set_state(a, AUTOMOUNT_WAITING);
 625
 626         return;
 627
 628 fail:
 629         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 630
 631         safe_close_pair(p);
 632
 633         if (mounted) {
 634                 r = repeat_unmount(a->where, MNT_DETACH);
 635                 if (r < 0)
 636                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 637         }
 638
 639         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 640 }
 641
 642 static void *expire_thread(void *p) {
 643         struct autofs_dev_ioctl param;
 644         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 645         int r;
 646
 647         assert(data->dev_autofs_fd >= 0);
 648         assert(data->ioctl_fd >= 0);
 649
 650         init_autofs_dev_ioctl(&param);
 651         param.ioctlfd = data->ioctl_fd;
 652
 653         do {
 654                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 655         } while (r >= 0);
 656
 657         if (errno != EAGAIN)
 658                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 659
 660         return NULL;
 661 }
 662
 663 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 664         Automount *a = AUTOMOUNT(userdata);
 665         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 666         int r;
 667
 668         assert(a);
 669         assert(source == a->expire_event_source);
 670
 671         data = new0(struct expire_data, 1);
 672         if (!data)
 673                 return log_oom();
 674
 675         data->ioctl_fd = -1;
 676
 677         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 678         if (data->dev_autofs_fd < 0)
 679                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 680
 681         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 682         if (data->ioctl_fd < 0)
 683                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 684
 685         r = asynchronous_job(expire_thread, data);
 686         if (r < 0)
 687                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 688
 689         data = NULL;
 690
 691         return automount_start_expire(a);
 692 }
 693
 694 static int automount_start_expire(Automount *a) {
 695         int r;
 696         usec_t timeout;
 697
 698         assert(a);
 699
 700         if (a->timeout_idle_usec == 0)
 701                 return 0;
 702
 703         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 704
 705         if (a->expire_event_source) {
 706                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 707                 if (r < 0)
 708                         return r;
 709
 710                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 711         }
 712
 713         r = sd_event_add_time(
 714                         UNIT(a)->manager->event,
 715                         &a->expire_event_source,
 716                         CLOCK_MONOTONIC, timeout, 0,
 717                         automount_dispatch_expire, a);
 718         if (r < 0)
 719                 return r;
 720
 721         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 722
 723         return 0;
 724 }
 725
 726 static void automount_stop_expire(Automount *a) {
 727         assert(a);
 728
 729         if (!a->expire_event_source)
 730                 return;
 731
 732         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 733 }
 734
 735 static void automount_enter_running(Automount *a) {
 736         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 737         Unit *trigger;
 738         struct stat st;
 739         int r;
 740
 741         assert(a);
 742
 743         /* If the user masked our unit in the meantime, fail */
 744         if (UNIT(a)->load_state != UNIT_LOADED) {
 745                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 746                 goto fail;
 747         }
 748
 749         /* We don't take mount requests anymore if we are supposed to
 750          * shut down anyway */
 751         if (unit_stop_pending(UNIT(a))) {
 752                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 753                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 754                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 755                 return;
 756         }
 757
 758         mkdir_p_label(a->where, a->directory_mode);
 759
 760         /* Before we do anything, let's see if somebody is playing games with us? */
 761         if (lstat(a->where, &st) < 0) {
 762                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 763                 goto fail;
 764         }
 765
 766         /* The mount unit may have been explicitly started before we got the
 767          * autofs request. Ack it to unblock anything waiting on the mount point. */
 768         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 769                 log_unit_info(UNIT(a), "Automount point already active?");
 770                 automount_send_ready(a, a->tokens, 0);
 771                 return;
 772         }
 773
 774         trigger = UNIT_TRIGGER(UNIT(a));
 775         if (!trigger) {
 776                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 777                 goto fail;
 778         }
 779
 780         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 781         if (r < 0) {
 782                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 783                 goto fail;
 784         }
 785
 786         automount_set_state(a, AUTOMOUNT_RUNNING);
 787         return;
 788
 789 fail:
 790         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 791 }
 792
 793 static int automount_start(Unit *u) {
 794         Automount *a = AUTOMOUNT(u);
 795         Unit *trigger;
 796         int r;
 797
 798         assert(a);
 799         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 800
 801         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 802                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 803                 return -EEXIST;
 804         }
 805
 806         trigger = UNIT_TRIGGER(u);
 807         if (!trigger || trigger->load_state != UNIT_LOADED) {
 808                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 809                 return -ENOENT;
 810         }
 811
 812         r = unit_start_limit_test(u);
 813         if (r < 0) {
 814                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 815                 return r;
 816         }
 817
 818         r = unit_acquire_invocation_id(u);
 819         if (r < 0)
 820                 return r;
 821
 822         a->result = AUTOMOUNT_SUCCESS;
 823         automount_enter_waiting(a);
 824         return 1;
 825 }
 826
 827 static int automount_stop(Unit *u) {
 828         Automount *a = AUTOMOUNT(u);
 829
 830         assert(a);
 831         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 832
 833         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 834         return 1;
 835 }
 836
 837 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 838         Automount *a = AUTOMOUNT(u);
 839         Iterator i;
 840         void *p;
 841         int r;
 842
 843         assert(a);
 844         assert(f);
 845         assert(fds);
 846
 847         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 848         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 849         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 850
 851         SET_FOREACH(p, a->tokens, i)
 852                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 853         SET_FOREACH(p, a->expire_tokens, i)
 854                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 855
 856         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 857         if (r < 0)
 858                 return r;
 859
 860         return 0;
 861 }
 862
 863 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 864         Automount *a = AUTOMOUNT(u);
 865         int r;
 866
 867         assert(a);
 868         assert(fds);
 869
 870         if (streq(key, "state")) {
 871                 AutomountState state;
 872
 873                 state = automount_state_from_string(value);
 874                 if (state < 0)
 875                         log_unit_debug(u, "Failed to parse state value: %s", value);
 876                 else
 877                         a->deserialized_state = state;
 878         } else if (streq(key, "result")) {
 879                 AutomountResult f;
 880
 881                 f = automount_result_from_string(value);
 882                 if (f < 0)
 883                         log_unit_debug(u, "Failed to parse result value: %s", value);
 884                 else if (f != AUTOMOUNT_SUCCESS)
 885                         a->result = f;
 886
 887         } else if (streq(key, "dev-id")) {
 888                 unsigned long d;
 889
 890                 if (safe_atolu(value, &d) < 0)
 891                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 892                 else
 893                         a->dev_id = (dev_t) d;
 894
 895         } else if (streq(key, "token")) {
 896                 unsigned token;
 897
 898                 if (safe_atou(value, &token) < 0)
 899                         log_unit_debug(u, "Failed to parse token value: %s", value);
 900                 else {
 901                         r = set_ensure_allocated(&a->tokens, NULL);
 902                         if (r < 0) {
 903                                 log_oom();
 904                                 return 0;
 905                         }
 906
 907                         r = set_put(a->tokens, UINT_TO_PTR(token));
 908                         if (r < 0)
 909                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 910                 }
 911         } else if (streq(key, "expire-token")) {
 912                 unsigned token;
 913
 914                 if (safe_atou(value, &token) < 0)
 915                         log_unit_debug(u, "Failed to parse token value: %s", value);
 916                 else {
 917                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 918                         if (r < 0) {
 919                                 log_oom();
 920                                 return 0;
 921                         }
 922
 923                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 924                         if (r < 0)
 925                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 926                 }
 927         } else if (streq(key, "pipe-fd")) {
 928                 int fd;
 929
 930                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 931                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 932                 else {
 933                         safe_close(a->pipe_fd);
 934                         a->pipe_fd = fdset_remove(fds, fd);
 935                 }
 936         } else
 937                 log_unit_debug(u, "Unknown serialization key: %s", key);
 938
 939         return 0;
 940 }
 941
 942 static UnitActiveState automount_active_state(Unit *u) {
 943         assert(u);
 944
 945         return state_translation_table[AUTOMOUNT(u)->state];
 946 }
 947
 948 static const char *automount_sub_state_to_string(Unit *u) {
 949         assert(u);
 950
 951         return automount_state_to_string(AUTOMOUNT(u)->state);
 952 }
 953
 954 static bool automount_may_gc(Unit *u) {
 955         Unit *t;
 956
 957         assert(u);
 958
 959         t = UNIT_TRIGGER(u);
 960         if (!t)
 961                 return true;
 962
 963         return UNIT_VTABLE(t)->may_gc(t);
 964 }
 965
 966 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 967         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 968         union autofs_v5_packet_union packet;
 969         Automount *a = AUTOMOUNT(userdata);
 970         Unit *trigger;
 971         int r;
 972
 973         assert(a);
 974         assert(fd == a->pipe_fd);
 975
 976         if (events != EPOLLIN) {
 977                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 978                 goto fail;
 979         }
 980
 981         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 982         if (r < 0) {
 983                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 984                 goto fail;
 985         }
 986
 987         switch (packet.hdr.type) {
 988
 989         case autofs_ptype_missing_direct:
 990
 991                 if (packet.v5_packet.pid > 0) {
 992                         _cleanup_free_ char *p = NULL;
 993
 994                         get_process_comm(packet.v5_packet.pid, &p);
 995                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 996                 } else
 997                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
 998
 999                 r = set_ensure_allocated(&a->tokens, NULL);
1000                 if (r < 0) {
1001                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1002                         goto fail;
1003                 }
1004
1005                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1006                 if (r < 0) {
1007                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1008                         goto fail;
1009                 }
1010
1011                 automount_enter_running(a);
1012                 break;
1013
1014         case autofs_ptype_expire_direct:
1015                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1016
1017                 automount_stop_expire(a);
1018
1019                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1020                 if (r < 0) {
1021                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1022                         goto fail;
1023                 }
1024
1025                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1026                 if (r < 0) {
1027                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1028                         goto fail;
1029                 }
1030
1031                 trigger = UNIT_TRIGGER(UNIT(a));
1032                 if (!trigger) {
1033                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1034                         goto fail;
1035                 }
1036
1037                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1038                 if (r < 0) {
1039                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1040                         goto fail;
1041                 }
1042                 break;
1043
1044         default:
1045                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1046                 break;
1047         }
1048
1049         return 0;
1050
1051 fail:
1052         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1053         return 0;
1054 }
1055
1056 static void automount_shutdown(Manager *m) {
1057         assert(m);
1058
1059         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1060 }
1061
1062 static void automount_reset_failed(Unit *u) {
1063         Automount *a = AUTOMOUNT(u);
1064
1065         assert(a);
1066
1067         if (a->state == AUTOMOUNT_FAILED)
1068                 automount_set_state(a, AUTOMOUNT_DEAD);
1069
1070         a->result = AUTOMOUNT_SUCCESS;
1071 }
1072
1073 static bool automount_supported(void) {
1074         static int supported = -1;
1075
1076         if (supported < 0)
1077                 supported = access("/dev/autofs", F_OK) >= 0;
1078
1079         return supported;
1080 }
1081
1082 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1083         [AUTOMOUNT_SUCCESS] = "success",
1084         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1085         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1086         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1087 };
1088
1089 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1090
1091 const UnitVTable automount_vtable = {
1092         .object_size = sizeof(Automount),
1093
1094         .sections =
1095                 "Unit\0"
1096                 "Automount\0"
1097                 "Install\0",
1098
1099         .init = automount_init,
1100         .load = automount_load,
1101         .done = automount_done,
1102
1103         .coldplug = automount_coldplug,
1104
1105         .dump = automount_dump,
1106
1107         .start = automount_start,
1108         .stop = automount_stop,
1109
1110         .serialize = automount_serialize,
1111         .deserialize_item = automount_deserialize_item,
1112
1113         .active_state = automount_active_state,
1114         .sub_state_to_string = automount_sub_state_to_string,
1115
1116         .may_gc = automount_may_gc,
1117
1118         .trigger_notify = automount_trigger_notify,
1119
1120         .reset_failed = automount_reset_failed,
1121
1122         .bus_vtable = bus_automount_vtable,
1123         .bus_set_property = bus_automount_set_property,
1124
1125         .can_transient = true,
1126
1127         .shutdown = automount_shutdown,
1128         .supported = automount_supported,
1129
1130         .status_message_formats = {
1131                 .finished_start_job = {
1132                         [JOB_DONE]       = "Set up automount %s.",
1133                         [JOB_FAILED]     = "Failed to set up automount %s.",
1134                 },
1135                 .finished_stop_job = {
1136                         [JOB_DONE]       = "Unset automount %s.",
1137                         [JOB_FAILED]     = "Failed to unset automount %s.",
1138                 },
1139         },
1140 };