src/core/automount.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <limits.h>
  23 #include <linux/auto_dev-ioctl.h>
  24 #include <linux/auto_fs4.h>
  25 #include <sys/epoll.h>
  26 #include <sys/mount.h>
  27 #include <sys/stat.h>
  28 #include <unistd.h>
  29
  30 #include "alloc-util.h"
  31 #include "async.h"
  32 #include "automount.h"
  33 #include "bus-error.h"
  34 #include "bus-util.h"
  35 #include "dbus-automount.h"
  36 #include "fd-util.h"
  37 #include "format-util.h"
  38 #include "io-util.h"
  39 #include "label.h"
  40 #include "mkdir.h"
  41 #include "mount-util.h"
  42 #include "mount.h"
  43 #include "parse-util.h"
  44 #include "path-util.h"
  45 #include "process-util.h"
  46 #include "special.h"
  47 #include "stdio-util.h"
  48 #include "string-table.h"
  49 #include "string-util.h"
  50 #include "unit-name.h"
  51 #include "unit.h"
  52
  53 static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
  54         [AUTOMOUNT_DEAD] = UNIT_INACTIVE,
  55         [AUTOMOUNT_WAITING] = UNIT_ACTIVE,
  56         [AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
  57         [AUTOMOUNT_FAILED] = UNIT_FAILED
  58 };
  59
  60 struct expire_data {
  61         int dev_autofs_fd;
  62         int ioctl_fd;
  63 };
  64
  65 static inline void expire_data_free(struct expire_data *data) {
  66         if (!data)
  67                 return;
  68
  69         safe_close(data->dev_autofs_fd);
  70         safe_close(data->ioctl_fd);
  71         free(data);
  72 }
  73
  74 DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
  75
  76 static int open_dev_autofs(Manager *m);
  77 static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
  78 static int automount_start_expire(Automount *a);
  79 static void automount_stop_expire(Automount *a);
  80 static int automount_send_ready(Automount *a, Set *tokens, int status);
  81
  82 static void automount_init(Unit *u) {
  83         Automount *a = AUTOMOUNT(u);
  84
  85         assert(u);
  86         assert(u->load_state == UNIT_STUB);
  87
  88         a->pipe_fd = -1;
  89         a->directory_mode = 0755;
  90         UNIT(a)->ignore_on_isolate = true;
  91 }
  92
  93 static void unmount_autofs(Automount *a) {
  94         int r;
  95
  96         assert(a);
  97
  98         if (a->pipe_fd < 0)
  99                 return;
 100
 101         a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
 102         a->pipe_fd = safe_close(a->pipe_fd);
 103
 104         /* If we reload/reexecute things we keep the mount point around */
 105         if (!IN_SET(UNIT(a)->manager->exit_code, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
 106
 107                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 108                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 109
 110                 if (a->where) {
 111                         r = repeat_unmount(a->where, MNT_DETACH);
 112                         if (r < 0)
 113                                 log_error_errno(r, "Failed to unmount: %m");
 114                 }
 115         }
 116 }
 117
 118 static void automount_done(Unit *u) {
 119         Automount *a = AUTOMOUNT(u);
 120
 121         assert(a);
 122
 123         unmount_autofs(a);
 124
 125         a->where = mfree(a->where);
 126
 127         a->tokens = set_free(a->tokens);
 128         a->expire_tokens = set_free(a->expire_tokens);
 129
 130         a->expire_event_source = sd_event_source_unref(a->expire_event_source);
 131 }
 132
 133 static int automount_add_mount_links(Automount *a) {
 134         _cleanup_free_ char *parent = NULL;
 135
 136         assert(a);
 137
 138         parent = dirname_malloc(a->where);
 139         if (!parent)
 140                 return -ENOMEM;
 141
 142         return unit_require_mounts_for(UNIT(a), parent);
 143 }
 144
 145 static int automount_add_default_dependencies(Automount *a) {
 146         int r;
 147
 148         assert(a);
 149
 150         if (!UNIT(a)->default_dependencies)
 151                 return 0;
 152
 153         if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
 154                 return 0;
 155
 156         r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true);
 157         if (r < 0)
 158                 return r;
 159
 160         return 0;
 161 }
 162
 163 static int automount_verify(Automount *a) {
 164         _cleanup_free_ char *e = NULL;
 165         int r;
 166
 167         assert(a);
 168
 169         if (UNIT(a)->load_state != UNIT_LOADED)
 170                 return 0;
 171
 172         if (path_equal(a->where, "/")) {
 173                 log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing.");
 174                 return -EINVAL;
 175         }
 176
 177         r = unit_name_from_path(a->where, ".automount", &e);
 178         if (r < 0)
 179                 return log_unit_error(UNIT(a), "Failed to generate unit name from path: %m");
 180
 181         if (!unit_has_name(UNIT(a), e)) {
 182                 log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing.");
 183                 return -EINVAL;
 184         }
 185
 186         return 0;
 187 }
 188
 189 static int automount_set_where(Automount *a) {
 190         int r;
 191
 192         assert(a);
 193
 194         if (a->where)
 195                 return 0;
 196
 197         r = unit_name_to_path(UNIT(a)->id, &a->where);
 198         if (r < 0)
 199                 return r;
 200
 201         path_kill_slashes(a->where);
 202         return 1;
 203 }
 204
 205 static int automount_load(Unit *u) {
 206         Automount *a = AUTOMOUNT(u);
 207         int r;
 208
 209         assert(u);
 210         assert(u->load_state == UNIT_STUB);
 211
 212         /* Load a .automount file */
 213         r = unit_load_fragment_and_dropin_optional(u);
 214         if (r < 0)
 215                 return r;
 216
 217         if (u->load_state == UNIT_LOADED) {
 218                 Unit *x;
 219
 220                 r = automount_set_where(a);
 221                 if (r < 0)
 222                         return r;
 223
 224                 r = unit_load_related_unit(u, ".mount", &x);
 225                 if (r < 0)
 226                         return r;
 227
 228                 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
 229                 if (r < 0)
 230                         return r;
 231
 232                 r = automount_add_mount_links(a);
 233                 if (r < 0)
 234                         return r;
 235
 236                 r = automount_add_default_dependencies(a);
 237                 if (r < 0)
 238                         return r;
 239         }
 240
 241         return automount_verify(a);
 242 }
 243
 244 static void automount_set_state(Automount *a, AutomountState state) {
 245         AutomountState old_state;
 246         assert(a);
 247
 248         old_state = a->state;
 249         a->state = state;
 250
 251         if (state != AUTOMOUNT_RUNNING)
 252                 automount_stop_expire(a);
 253
 254         if (state != AUTOMOUNT_WAITING &&
 255             state != AUTOMOUNT_RUNNING)
 256                 unmount_autofs(a);
 257
 258         if (state != old_state)
 259                 log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
 260
 261         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], true);
 262 }
 263
 264 static int automount_coldplug(Unit *u) {
 265         Automount *a = AUTOMOUNT(u);
 266         int r;
 267
 268         assert(a);
 269         assert(a->state == AUTOMOUNT_DEAD);
 270
 271         if (a->deserialized_state == a->state)
 272                 return 0;
 273
 274         if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
 275
 276                 r = automount_set_where(a);
 277                 if (r < 0)
 278                         return r;
 279
 280                 r = open_dev_autofs(u->manager);
 281                 if (r < 0)
 282                         return r;
 283
 284                 assert(a->pipe_fd >= 0);
 285
 286                 r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
 287                 if (r < 0)
 288                         return r;
 289
 290                 (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 291                 if (a->deserialized_state == AUTOMOUNT_RUNNING) {
 292                         r = automount_start_expire(a);
 293                         if (r < 0)
 294                                 log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 295                 }
 296
 297                 automount_set_state(a, a->deserialized_state);
 298         }
 299
 300         return 0;
 301 }
 302
 303 static void automount_dump(Unit *u, FILE *f, const char *prefix) {
 304         char time_string[FORMAT_TIMESPAN_MAX];
 305         Automount *a = AUTOMOUNT(u);
 306
 307         assert(a);
 308
 309         fprintf(f,
 310                 "%sAutomount State: %s\n"
 311                 "%sResult: %s\n"
 312                 "%sWhere: %s\n"
 313                 "%sDirectoryMode: %04o\n"
 314                 "%sTimeoutIdleUSec: %s\n",
 315                 prefix, automount_state_to_string(a->state),
 316                 prefix, automount_result_to_string(a->result),
 317                 prefix, a->where,
 318                 prefix, a->directory_mode,
 319                 prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
 320 }
 321
 322 static void automount_enter_dead(Automount *a, AutomountResult f) {
 323         assert(a);
 324
 325         if (a->result == AUTOMOUNT_SUCCESS)
 326                 a->result = f;
 327
 328         automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
 329 }
 330
 331 static int open_dev_autofs(Manager *m) {
 332         struct autofs_dev_ioctl param;
 333
 334         assert(m);
 335
 336         if (m->dev_autofs_fd >= 0)
 337                 return m->dev_autofs_fd;
 338
 339         label_fix("/dev/autofs", false, false);
 340
 341         m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
 342         if (m->dev_autofs_fd < 0)
 343                 return log_error_errno(errno, "Failed to open /dev/autofs: %m");
 344
 345         init_autofs_dev_ioctl(&param);
 346         if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
 347                 m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
 348                 return -errno;
 349         }
 350
 351         log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
 352
 353         return m->dev_autofs_fd;
 354 }
 355
 356 static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
 357         struct autofs_dev_ioctl *param;
 358         size_t l;
 359
 360         assert(dev_autofs_fd >= 0);
 361         assert(where);
 362
 363         l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
 364         param = alloca(l);
 365
 366         init_autofs_dev_ioctl(param);
 367         param->size = l;
 368         param->ioctlfd = -1;
 369         param->openmount.devid = devid;
 370         strcpy(param->path, where);
 371
 372         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
 373                 return -errno;
 374
 375         if (param->ioctlfd < 0)
 376                 return -EIO;
 377
 378         (void) fd_cloexec(param->ioctlfd, true);
 379         return param->ioctlfd;
 380 }
 381
 382 static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
 383         uint32_t major, minor;
 384         struct autofs_dev_ioctl param;
 385
 386         assert(dev_autofs_fd >= 0);
 387         assert(ioctl_fd >= 0);
 388
 389         init_autofs_dev_ioctl(&param);
 390         param.ioctlfd = ioctl_fd;
 391
 392         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
 393                 return -errno;
 394
 395         major = param.protover.version;
 396
 397         init_autofs_dev_ioctl(&param);
 398         param.ioctlfd = ioctl_fd;
 399
 400         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
 401                 return -errno;
 402
 403         minor = param.protosubver.sub_version;
 404
 405         log_debug("Autofs protocol version %i.%i", major, minor);
 406         return 0;
 407 }
 408
 409 static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
 410         struct autofs_dev_ioctl param;
 411
 412         assert(dev_autofs_fd >= 0);
 413         assert(ioctl_fd >= 0);
 414
 415         init_autofs_dev_ioctl(&param);
 416         param.ioctlfd = ioctl_fd;
 417
 418         if (usec == USEC_INFINITY)
 419                 param.timeout.timeout = 0;
 420         else
 421                 /* Convert to seconds, rounding up. */
 422                 param.timeout.timeout = (usec + USEC_PER_SEC - 1) / USEC_PER_SEC;
 423
 424         if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
 425                 return -errno;
 426
 427         return 0;
 428 }
 429
 430 static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
 431         struct autofs_dev_ioctl param;
 432
 433         assert(dev_autofs_fd >= 0);
 434         assert(ioctl_fd >= 0);
 435
 436         init_autofs_dev_ioctl(&param);
 437         param.ioctlfd = ioctl_fd;
 438
 439         if (status != 0) {
 440                 param.fail.token = token;
 441                 param.fail.status = status;
 442         } else
 443                 param.ready.token = token;
 444
 445         if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
 446                 return -errno;
 447
 448         return 0;
 449 }
 450
 451 static int automount_send_ready(Automount *a, Set *tokens, int status) {
 452         _cleanup_close_ int ioctl_fd = -1;
 453         unsigned token;
 454         int r;
 455
 456         assert(a);
 457         assert(status <= 0);
 458
 459         if (set_isempty(tokens))
 460                 return 0;
 461
 462         ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 463         if (ioctl_fd < 0)
 464                 return ioctl_fd;
 465
 466         if (status != 0)
 467                 log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
 468         else
 469                 log_unit_debug(UNIT(a), "Sending success.");
 470
 471         r = 0;
 472
 473         /* Autofs thankfully does not hand out 0 as a token */
 474         while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
 475                 int k;
 476
 477                 /* Autofs fun fact:
 478                  *
 479                  * if you pass a positive status code here, kernels
 480                  * prior to 4.12 will freeze! Yay! */
 481
 482                 k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
 483                                       ioctl_fd,
 484                                       token,
 485                                       status);
 486                 if (k < 0)
 487                         r = k;
 488         }
 489
 490         return r;
 491 }
 492
 493 static void automount_trigger_notify(Unit *u, Unit *other) {
 494         Automount *a = AUTOMOUNT(u);
 495         int r;
 496
 497         assert(a);
 498         assert(other);
 499
 500         /* Filter out invocations with bogus state */
 501         if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
 502                 return;
 503
 504         /* Don't propagate state changes from the mount if we are already down */
 505         if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
 506                 return;
 507
 508         /* Propagate start limit hit state */
 509         if (other->start_limit_hit) {
 510                 automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
 511                 return;
 512         }
 513
 514         /* Don't propagate anything if there's still a job queued */
 515         if (other->job)
 516                 return;
 517
 518         /* The mount is successfully established */
 519         if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
 520                 (void) automount_send_ready(a, a->tokens, 0);
 521
 522                 r = automount_start_expire(a);
 523                 if (r < 0)
 524                         log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
 525
 526                 automount_set_state(a, AUTOMOUNT_RUNNING);
 527         }
 528
 529         if (IN_SET(MOUNT(other)->state,
 530                    MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
 531                    MOUNT_MOUNTED, MOUNT_REMOUNTING,
 532                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 533                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 534                    MOUNT_FAILED)) {
 535
 536                 (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
 537         }
 538
 539         if (MOUNT(other)->state == MOUNT_DEAD)
 540                 (void) automount_send_ready(a, a->expire_tokens, 0);
 541
 542         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
 543         if (IN_SET(MOUNT(other)->state,
 544                    MOUNT_DEAD, MOUNT_UNMOUNTING,
 545                    MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
 546                    MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
 547                    MOUNT_FAILED)) {
 548
 549                 (void) automount_send_ready(a, a->tokens, -ENODEV);
 550
 551                 automount_set_state(a, AUTOMOUNT_WAITING);
 552         }
 553 }
 554
 555 static void automount_enter_waiting(Automount *a) {
 556         _cleanup_close_ int ioctl_fd = -1;
 557         int p[2] = { -1, -1 };
 558         char name[sizeof("systemd-")-1 + DECIMAL_STR_MAX(pid_t) + 1];
 559         char options[sizeof("fd=,pgrp=,minproto=5,maxproto=5,direct")-1
 560                      + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
 561         bool mounted = false;
 562         int r, dev_autofs_fd;
 563         struct stat st;
 564
 565         assert(a);
 566         assert(a->pipe_fd < 0);
 567         assert(a->where);
 568
 569         set_clear(a->tokens);
 570
 571         r = unit_fail_if_symlink(UNIT(a), a->where);
 572         if (r < 0)
 573                 goto fail;
 574
 575         (void) mkdir_p_label(a->where, 0555);
 576
 577         unit_warn_if_dir_nonempty(UNIT(a), a->where);
 578
 579         dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
 580         if (dev_autofs_fd < 0) {
 581                 r = dev_autofs_fd;
 582                 goto fail;
 583         }
 584
 585         if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
 586                 r = -errno;
 587                 goto fail;
 588         }
 589
 590         xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
 591         xsprintf(name, "systemd-"PID_FMT, getpid_cached());
 592         if (mount(name, a->where, "autofs", 0, options) < 0) {
 593                 r = -errno;
 594                 goto fail;
 595         }
 596
 597         mounted = true;
 598
 599         p[1] = safe_close(p[1]);
 600
 601         if (stat(a->where, &st) < 0) {
 602                 r = -errno;
 603                 goto fail;
 604         }
 605
 606         ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
 607         if (ioctl_fd < 0) {
 608                 r = ioctl_fd;
 609                 goto fail;
 610         }
 611
 612         r = autofs_protocol(dev_autofs_fd, ioctl_fd);
 613         if (r < 0)
 614                 goto fail;
 615
 616         r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
 617         if (r < 0)
 618                 goto fail;
 619
 620         r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
 621         if (r < 0)
 622                 goto fail;
 623
 624         (void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
 625
 626         a->pipe_fd = p[0];
 627         a->dev_id = st.st_dev;
 628
 629         automount_set_state(a, AUTOMOUNT_WAITING);
 630
 631         return;
 632
 633 fail:
 634         log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
 635
 636         safe_close_pair(p);
 637
 638         if (mounted) {
 639                 r = repeat_unmount(a->where, MNT_DETACH);
 640                 if (r < 0)
 641                         log_error_errno(r, "Failed to unmount, ignoring: %m");
 642         }
 643
 644         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 645 }
 646
 647 static void *expire_thread(void *p) {
 648         struct autofs_dev_ioctl param;
 649         _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
 650         int r;
 651
 652         assert(data->dev_autofs_fd >= 0);
 653         assert(data->ioctl_fd >= 0);
 654
 655         init_autofs_dev_ioctl(&param);
 656         param.ioctlfd = data->ioctl_fd;
 657
 658         do {
 659                 r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
 660         } while (r >= 0);
 661
 662         if (errno != EAGAIN)
 663                 log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
 664
 665         return NULL;
 666 }
 667
 668 static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
 669         Automount *a = AUTOMOUNT(userdata);
 670         _cleanup_(expire_data_freep) struct expire_data *data = NULL;
 671         int r;
 672
 673         assert(a);
 674         assert(source == a->expire_event_source);
 675
 676         data = new0(struct expire_data, 1);
 677         if (!data)
 678                 return log_oom();
 679
 680         data->ioctl_fd = -1;
 681
 682         data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
 683         if (data->dev_autofs_fd < 0)
 684                 return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
 685
 686         data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
 687         if (data->ioctl_fd < 0)
 688                 return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
 689
 690         r = asynchronous_job(expire_thread, data);
 691         if (r < 0)
 692                 return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
 693
 694         data = NULL;
 695
 696         return automount_start_expire(a);
 697 }
 698
 699 static int automount_start_expire(Automount *a) {
 700         int r;
 701         usec_t timeout;
 702
 703         assert(a);
 704
 705         if (a->timeout_idle_usec == 0)
 706                 return 0;
 707
 708         timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
 709
 710         if (a->expire_event_source) {
 711                 r = sd_event_source_set_time(a->expire_event_source, timeout);
 712                 if (r < 0)
 713                         return r;
 714
 715                 return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
 716         }
 717
 718         r = sd_event_add_time(
 719                         UNIT(a)->manager->event,
 720                         &a->expire_event_source,
 721                         CLOCK_MONOTONIC, timeout, 0,
 722                         automount_dispatch_expire, a);
 723         if (r < 0)
 724                 return r;
 725
 726         (void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
 727
 728         return 0;
 729 }
 730
 731 static void automount_stop_expire(Automount *a) {
 732         assert(a);
 733
 734         if (!a->expire_event_source)
 735                 return;
 736
 737         (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
 738 }
 739
 740 static void automount_enter_running(Automount *a) {
 741         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 742         Unit *trigger;
 743         struct stat st;
 744         int r;
 745
 746         assert(a);
 747
 748         /* If the user masked our unit in the meantime, fail */
 749         if (UNIT(a)->load_state != UNIT_LOADED) {
 750                 log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
 751                 goto fail;
 752         }
 753
 754         /* We don't take mount requests anymore if we are supposed to
 755          * shut down anyway */
 756         if (unit_stop_pending(UNIT(a))) {
 757                 log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
 758                 automount_send_ready(a, a->tokens, -EHOSTDOWN);
 759                 automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
 760                 return;
 761         }
 762
 763         mkdir_p_label(a->where, a->directory_mode);
 764
 765         /* Before we do anything, let's see if somebody is playing games with us? */
 766         if (lstat(a->where, &st) < 0) {
 767                 log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
 768                 goto fail;
 769         }
 770
 771         /* The mount unit may have been explicitly started before we got the
 772          * autofs request. Ack it to unblock anything waiting on the mount point. */
 773         if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
 774                 log_unit_info(UNIT(a), "Automount point already active?");
 775                 automount_send_ready(a, a->tokens, 0);
 776                 return;
 777         }
 778
 779         trigger = UNIT_TRIGGER(UNIT(a));
 780         if (!trigger) {
 781                 log_unit_error(UNIT(a), "Unit to trigger vanished.");
 782                 goto fail;
 783         }
 784
 785         r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 786         if (r < 0) {
 787                 log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
 788                 goto fail;
 789         }
 790
 791         automount_set_state(a, AUTOMOUNT_RUNNING);
 792         return;
 793
 794 fail:
 795         automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
 796 }
 797
 798 static int automount_start(Unit *u) {
 799         Automount *a = AUTOMOUNT(u);
 800         Unit *trigger;
 801         int r;
 802
 803         assert(a);
 804         assert(a->state == AUTOMOUNT_DEAD || a->state == AUTOMOUNT_FAILED);
 805
 806         if (path_is_mount_point(a->where, NULL, 0) > 0) {
 807                 log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
 808                 return -EEXIST;
 809         }
 810
 811         trigger = UNIT_TRIGGER(u);
 812         if (!trigger || trigger->load_state != UNIT_LOADED) {
 813                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 814                 return -ENOENT;
 815         }
 816
 817         r = unit_start_limit_test(u);
 818         if (r < 0) {
 819                 automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
 820                 return r;
 821         }
 822
 823         r = unit_acquire_invocation_id(u);
 824         if (r < 0)
 825                 return r;
 826
 827         a->result = AUTOMOUNT_SUCCESS;
 828         automount_enter_waiting(a);
 829         return 1;
 830 }
 831
 832 static int automount_stop(Unit *u) {
 833         Automount *a = AUTOMOUNT(u);
 834
 835         assert(a);
 836         assert(a->state == AUTOMOUNT_WAITING || a->state == AUTOMOUNT_RUNNING);
 837
 838         automount_enter_dead(a, AUTOMOUNT_SUCCESS);
 839         return 1;
 840 }
 841
 842 static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
 843         Automount *a = AUTOMOUNT(u);
 844         Iterator i;
 845         void *p;
 846         int r;
 847
 848         assert(a);
 849         assert(f);
 850         assert(fds);
 851
 852         unit_serialize_item(u, f, "state", automount_state_to_string(a->state));
 853         unit_serialize_item(u, f, "result", automount_result_to_string(a->result));
 854         unit_serialize_item_format(u, f, "dev-id", "%u", (unsigned) a->dev_id);
 855
 856         SET_FOREACH(p, a->tokens, i)
 857                 unit_serialize_item_format(u, f, "token", "%u", PTR_TO_UINT(p));
 858         SET_FOREACH(p, a->expire_tokens, i)
 859                 unit_serialize_item_format(u, f, "expire-token", "%u", PTR_TO_UINT(p));
 860
 861         r = unit_serialize_item_fd(u, f, fds, "pipe-fd", a->pipe_fd);
 862         if (r < 0)
 863                 return r;
 864
 865         return 0;
 866 }
 867
 868 static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 869         Automount *a = AUTOMOUNT(u);
 870         int r;
 871
 872         assert(a);
 873         assert(fds);
 874
 875         if (streq(key, "state")) {
 876                 AutomountState state;
 877
 878                 state = automount_state_from_string(value);
 879                 if (state < 0)
 880                         log_unit_debug(u, "Failed to parse state value: %s", value);
 881                 else
 882                         a->deserialized_state = state;
 883         } else if (streq(key, "result")) {
 884                 AutomountResult f;
 885
 886                 f = automount_result_from_string(value);
 887                 if (f < 0)
 888                         log_unit_debug(u, "Failed to parse result value: %s", value);
 889                 else if (f != AUTOMOUNT_SUCCESS)
 890                         a->result = f;
 891
 892         } else if (streq(key, "dev-id")) {
 893                 unsigned d;
 894
 895                 if (safe_atou(value, &d) < 0)
 896                         log_unit_debug(u, "Failed to parse dev-id value: %s", value);
 897                 else
 898                         a->dev_id = (unsigned) d;
 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_check_gc(Unit *u) {
 959         assert(u);
 960
 961         if (!UNIT_TRIGGER(u))
 962                 return false;
 963
 964         return UNIT_VTABLE(UNIT_TRIGGER(u))->check_gc(UNIT_TRIGGER(u));
 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         .check_gc = automount_check_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 };