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 inline 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_NONBLOCK|O_CLOEXEC) < 0) {
 582                 r = -errno;
 583                 goto fail;
 584         }
 585
 586         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 587         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 588         if (mount(name, a->where, "autofs", 0, options) < 0) {
 589                 r = -errno;
 590                 goto fail;
 591         }
 592
 593         mounted = true;
 594
 595         p[1] = safe_close(p[1]);
 596
 597         if (stat(a->where, &st) < 0) {
 598                 r = -errno;
 599                 goto fail;
 600         }
 601
 602         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 603         if (ioctl_fd < 0) {
 604                 r = ioctl_fd;
 605                 goto fail;
 606         }
 607
 608         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 609         if (r < 0)
 610                 goto fail;
 611
 612         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 613         if (r < 0)
 614                 goto fail;
 615
 616         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 617         if (r < 0)
 618                 goto fail;
 619
 620         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 621
 622         a->pipe_fd = p[0];
 623         a->dev_id = st.st_dev;
 624
 625         automount_set_state(a, AUTOMOUNT_WAITING);
 626
 627         return;
 628
 629 fail:
 630         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 631
 632         safe_close_pair(p);
 633
 634         if (mounted) {
 635                 r = repeat_unmount(a->where, MNT_DETACH);
 636                 if (r < 0)
 637                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 638         }
 639
 640         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 641 }
 642
 643 static void *expire_thread(void *p) {
 644         struct autofs_dev_ioctl param;
 645         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 646         int r;
 647
 648         assert(data->dev_autofs_fd >= 0);
 649         assert(data->ioctl_fd >= 0);
 650
 651         init_autofs_dev_ioctl(&param);
 652         param.ioctlfd = data->ioctl_fd;
 653
 654         do {
 655                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 656         } while (r >= 0);
 657
 658         if (errno != EAGAIN)
 659                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 660
 661         return NULL;
 662 }
 663
 664 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 665         Automount *a = AUTOMOUNT(userdata);
 666         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 667         int r;
 668
 669         assert(a);
 670         assert(source == a->expire_event_source);
 671
 672         data = new0(struct expire_data, 1);
 673         if (!data)
 674                 return log_oom();
 675
 676         data->ioctl_fd = -1;
 677
 678         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 679         if (data->dev_autofs_fd < 0)
 680                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 681
 682         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 683         if (data->ioctl_fd < 0)
 684                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 685
 686         r = asynchronous_job(expire_thread, data);
 687         if (r < 0)
 688                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 689
 690         data = NULL;
 691
 692         return automount_start_expire(a);
 693 }
 694
 695 static int automount_start_expire(Automount *a) {
 696         int r;
 697         usec_t timeout;
 698
 699         assert(a);
 700
 701         if (a->timeout_idle_usec == 0)
 702                 return 0;
 703
 704         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 705
 706         if (a->expire_event_source) {
 707                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 708                 if (r < 0)
 709                         return r;
 710
 711                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 712         }
 713
 714         r = sd_event_add_time(
 715                         UNIT(a)->manager->event,
 716                         &a->expire_event_source,
 717                         CLOCK_MONOTONIC, timeout, 0,
 718                         automount_dispatch_expire, a);
 719         if (r < 0)
 720                 return r;
 721
 722         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 723
 724         return 0;
 725 }
 726
 727 static void automount_stop_expire(Automount *a) {
 728         assert(a);
 729
 730         if (!a->expire_event_source)
 731                 return;
 732
 733         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 734 }
 735
 736 static void automount_enter_running(Automount *a) {
 737         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 738         Unit *trigger;
 739         struct stat st;
 740         int r;
 741
 742         assert(a);
 743
 744         /* If the user masked our unit in the meantime, fail */
 745         if (UNIT(a)->load_state != UNIT_LOADED) {
 746                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 747                 goto fail;
 748         }
 749
 750         /* We don't take mount requests anymore if we are supposed to
 751          * shut down anyway */
 752         if (unit_stop_pending(UNIT(a))) {
 753                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 754                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 755                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 756                 return;
 757         }
 758
 759         mkdir_p_label(a->where, a->directory_mode);
 760
 761         /* Before we do anything, let's see if somebody is playing games with us? */
 762         if (lstat(a->where, &st) < 0) {
 763                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 764                 goto fail;
 765         }
 766
 767         /* The mount unit may have been explicitly started before we got the
 768          * autofs request. Ack it to unblock anything waiting on the mount point. */
 769         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 770                 log_unit_info(UNIT(a), "Automount point already active?");
 771                 automount_send_ready(a, a->tokens, 0);
 772                 return;
 773         }
 774
 775         trigger = UNIT_TRIGGER(UNIT(a));
 776         if (!trigger) {
 777                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 778                 goto fail;
 779         }
 780
 781         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 782         if (r < 0) {
 783                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 784                 goto fail;
 785         }
 786
 787         automount_set_state(a, AUTOMOUNT_RUNNING);
 788         return;
 789
 790 fail:
 791         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 792 }
 793
 794 static int automount_start(Unit *u) {
 795         Automount *a = AUTOMOUNT(u);
 796         Unit *trigger;
 797         int r;
 798
 799         assert(a);
 800         assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
 801
 802         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 803                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 804                 return -EEXIST;
 805         }
 806
 807         trigger = UNIT_TRIGGER(u);
 808         if (!trigger || trigger->load_state != UNIT_LOADED) {
 809                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 810                 return -ENOENT;
 811         }
 812
 813         r = unit_start_limit_test(u);
 814         if (r < 0) {
 815                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 816                 return r;
 817         }
 818
 819         r = unit_acquire_invocation_id(u);
 820         if (r < 0)
 821                 return r;
 822
 823         a->result = AUTOMOUNT_SUCCESS;
 824         automount_enter_waiting(a);
 825         return 1;
 826 }
 827
 828 static int automount_stop(Unit *u) {
 829         Automount *a = AUTOMOUNT(u);
 830
 831         assert(a);
 832         assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
 833
 834         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 835         return 1;
 836 }
 837
 838 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 839         Automount *a = AUTOMOUNT(u);
 840         Iterator i;
 841         void *p;
 842         int r;
 843
 844         assert(a);
 845         assert(f);
 846         assert(fds);
 847
 848         (void) serialize_item(f, "state", automount_state_to_string(a->state));
 849         (void) serialize_item(f, "result", automount_result_to_string(a->result));
 850         (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id);
 851
 852         SET_FOREACH(p, a->tokens, i)
 853                 (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p));
 854         SET_FOREACH(p, a->expire_tokens, i)
 855                 (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p));
 856
 857         r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd);
 858         if (r < 0)
 859                 return r;
 860
 861         return 0;
 862 }
 863
 864 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 865         Automount *a = AUTOMOUNT(u);
 866         int r;
 867
 868         assert(a);
 869         assert(fds);
 870
 871         if (streq(key, "state")) {
 872                 AutomountState state;
 873
 874                 state = automount_state_from_string(value);
 875                 if (state < 0)
 876                         log_unit_debug(u, "Failed to parse state value: %s", value);
 877                 else
 878                         a->deserialized_state = state;
 879         } else if (streq(key, "result")) {
 880                 AutomountResult f;
 881
 882                 f = automount_result_from_string(value);
 883                 if (f < 0)
 884                         log_unit_debug(u, "Failed to parse result value: %s", value);
 885                 else if (f != AUTOMOUNT_SUCCESS)
 886                         a->result = f;
 887
 888         } else if (streq(key, "dev-id")) {
 889                 unsigned long d;
 890
 891                 if (safe_atolu(value, &d) < 0)
 892                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 893                 else
 894                         a->dev_id = (dev_t) d;
 895
 896         } else if (streq(key, "token")) {
 897                 unsigned token;
 898
 899                 if (safe_atou(value, &token) < 0)
 900                         log_unit_debug(u, "Failed to parse token value: %s", value);
 901                 else {
 902                         r = set_ensure_allocated(&a->tokens, NULL);
 903                         if (r < 0) {
 904                                 log_oom();
 905                                 return 0;
 906                         }
 907
 908                         r = set_put(a->tokens, UINT_TO_PTR(token));
 909                         if (r < 0)
 910                                 log_unit_error_errno(u, r, "Failed to add token to set: %m");
 911                 }
 912         } else if (streq(key, "expire-token")) {
 913                 unsigned token;
 914
 915                 if (safe_atou(value, &token) < 0)
 916                         log_unit_debug(u, "Failed to parse token value: %s", value);
 917                 else {
 918                         r = set_ensure_allocated(&a->expire_tokens, NULL);
 919                         if (r < 0) {
 920                                 log_oom();
 921                                 return 0;
 922                         }
 923
 924                         r = set_put(a->expire_tokens, UINT_TO_PTR(token));
 925                         if (r < 0)
 926                                 log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
 927                 }
 928         } else if (streq(key, "pipe-fd")) {
 929                 int fd;
 930
 931                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 932                         log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
 933                 else {
 934                         safe_close(a->pipe_fd);
 935                         a->pipe_fd = fdset_remove(fds, fd);
 936                 }
 937         } else
 938                 log_unit_debug(u, "Unknown serialization key: %s", key);
 939
 940         return 0;
 941 }
 942
 943 static UnitActiveState automount_active_state(Unit *u) {
 944         assert(u);
 945
 946         return state_translation_table[AUTOMOUNT(u)->state];
 947 }
 948
 949 static const char *automount_sub_state_to_string(Unit *u) {
 950         assert(u);
 951
 952         return automount_state_to_string(AUTOMOUNT(u)->state);
 953 }
 954
 955 static bool automount_may_gc(Unit *u) {
 956         Unit *t;
 957
 958         assert(u);
 959
 960         t = UNIT_TRIGGER(u);
 961         if (!t)
 962                 return true;
 963
 964         return UNIT_VTABLE(t)->may_gc(t);
 965 }
 966
 967 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
 968         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 969         union autofs_v5_packet_union packet;
 970         Automount *a = AUTOMOUNT(userdata);
 971         Unit *trigger;
 972         int r;
 973
 974         assert(a);
 975         assert(fd == a->pipe_fd);
 976
 977         if (events != EPOLLIN) {
 978                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
 979                 goto fail;
 980         }
 981
 982         r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
 983         if (r < 0) {
 984                 log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
 985                 goto fail;
 986         }
 987
 988         switch (packet.hdr.type) {
 989
 990         case autofs_ptype_missing_direct:
 991
 992                 if (packet.v5_packet.pid > 0) {
 993                         _cleanup_free_ char *p = NULL;
 994
 995                         get_process_comm(packet.v5_packet.pid, &p);
 996                         log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
 997                 } else
 998                         log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
 999
1000                 r = set_ensure_allocated(&a->tokens, NULL);
1001                 if (r < 0) {
1002                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1003                         goto fail;
1004                 }
1005
1006                 r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1007                 if (r < 0) {
1008                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1009                         goto fail;
1010                 }
1011
1012                 automount_enter_running(a);
1013                 break;
1014
1015         case autofs_ptype_expire_direct:
1016                 log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
1017
1018                 automount_stop_expire(a);
1019
1020                 r = set_ensure_allocated(&a->expire_tokens, NULL);
1021                 if (r < 0) {
1022                         log_unit_error(UNIT(a), "Failed to allocate token set.");
1023                         goto fail;
1024                 }
1025
1026                 r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
1027                 if (r < 0) {
1028                         log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
1029                         goto fail;
1030                 }
1031
1032                 trigger = UNIT_TRIGGER(UNIT(a));
1033                 if (!trigger) {
1034                         log_unit_error(UNIT(a), "Unit to trigger vanished.");
1035                         goto fail;
1036                 }
1037
1038                 r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
1039                 if (r < 0) {
1040                         log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
1041                         goto fail;
1042                 }
1043                 break;
1044
1045         default:
1046                 log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
1047                 break;
1048         }
1049
1050         return 0;
1051
1052 fail:
1053         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
1054         return 0;
1055 }
1056
1057 static void automount_shutdown(Manager *m) {
1058         assert(m);
1059
1060         m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
1061 }
1062
1063 static void automount_reset_failed(Unit *u) {
1064         Automount *a = AUTOMOUNT(u);
1065
1066         assert(a);
1067
1068         if (a->state == AUTOMOUNT_FAILED)
1069                 automount_set_state(a, AUTOMOUNT_DEAD);
1070
1071         a->result = AUTOMOUNT_SUCCESS;
1072 }
1073
1074 static bool automount_supported(void) {
1075         static int supported = -1;
1076
1077         if (supported < 0)
1078                 supported = access("/dev/autofs", F_OK) >= 0;
1079
1080         return supported;
1081 }
1082
1083 static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
1084         [AUTOMOUNT_SUCCESS] = "success",
1085         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
1086         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1087         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
1088 };
1089
1090 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
1091
1092 const UnitVTable automount_vtable = {
1093         .object_size = sizeof(Automount),
1094
1095         .sections =
1096                 "Unit\0"
1097                 "Automount\0"
1098                 "Install\0",
1099
1100         .init = automount_init,
1101         .load = automount_load,
1102         .done = automount_done,
1103
1104         .coldplug = automount_coldplug,
1105
1106         .dump = automount_dump,
1107
1108         .start = automount_start,
1109         .stop = automount_stop,
1110
1111         .serialize = automount_serialize,
1112         .deserialize_item = automount_deserialize_item,
1113
1114         .active_state = automount_active_state,
1115         .sub_state_to_string = automount_sub_state_to_string,
1116
1117         .may_gc = automount_may_gc,
1118
1119         .trigger_notify = automount_trigger_notify,
1120
1121         .reset_failed = automount_reset_failed,
1122
1123         .bus_vtable = bus_automount_vtable,
1124         .bus_set_property = bus_automount_set_property,
1125
1126         .can_transient = true,
1127
1128         .shutdown = automount_shutdown,
1129         .supported = automount_supported,
1130
1131         .status_message_formats = {
1132                 .finished_start_job = {
1133                         [JOB_DONE]       = "Set up automount %s.",
1134                         [JOB_FAILED]     = "Failed to set up automount %s.",
1135                 },
1136                 .finished_stop_job = {
1137                         [JOB_DONE]       = "Unset automount %s.",
1138                         [JOB_FAILED]     = "Failed to unset automount %s.",
1139                 },
1140         },
1141 };