src/core/automount.c

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