git.ozlabs.org Git - petitboot/blob - discover/device-handler.c

   1
   2 #include <assert.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5 #include <string.h>
   6 #include <errno.h>
   7 #include <sys/stat.h>
   8 #include <sys/wait.h>
   9
  10 #include <pb-config/pb-config.h>
  11 #include <talloc/talloc.h>
  12 #include <list/list.h>
  13 #include <log/log.h>
  14 #include <types/types.h>
  15 #include <system/system.h>
  16 #include <process/process.h>
  17 #include <url/url.h>
  18
  19 #include "device-handler.h"
  20 #include "discover-server.h"
  21 #include "event.h"
  22 #include "parser.h"
  23 #include "resource.h"
  24 #include "udev.h"
  25 #include "paths.h"
  26 #include "boot.h"
  27
  28 struct device_handler {
  29         struct discover_server  *server;
  30         int                     dry_run;
  31
  32         struct discover_device  **devices;
  33         unsigned int            n_devices;
  34
  35         struct waitset          *waitset;
  36         struct waiter           *timeout_waiter;
  37         bool                    autoboot_enabled;
  38         unsigned int            sec_to_boot;
  39
  40         struct discover_boot_option *default_boot_option;
  41         struct list             unresolved_boot_options;
  42 };
  43
  44 void discover_context_add_boot_option(struct discover_context *ctx,
  45                 struct discover_boot_option *boot_option)
  46 {
  47         boot_option->source = ctx->parser;
  48         list_add_tail(&ctx->boot_options, &boot_option->list);
  49         talloc_steal(ctx, boot_option);
  50 }
  51
  52 /**
  53  * device_handler_get_device_count - Get the count of current handler devices.
  54  */
  55
  56 int device_handler_get_device_count(const struct device_handler *handler)
  57 {
  58         return handler->n_devices;
  59 }
  60
  61 /**
  62  * device_handler_get_device - Get a handler device by index.
  63  */
  64
  65 const struct discover_device *device_handler_get_device(
  66         const struct device_handler *handler, unsigned int index)
  67 {
  68         if (index >= handler->n_devices) {
  69                 assert(0 && "bad index");
  70                 return NULL;
  71         }
  72
  73         return handler->devices[index];
  74 }
  75
  76 struct discover_boot_option *discover_boot_option_create(
  77                 struct discover_context *ctx,
  78                 struct discover_device *device)
  79 {
  80         struct discover_boot_option *opt;
  81
  82         opt = talloc_zero(ctx, struct discover_boot_option);
  83         opt->option = talloc_zero(opt, struct boot_option);
  84         opt->device = device;
  85
  86         return opt;
  87 }
  88
  89 static int device_match_path(struct discover_device *dev, const char *path)
  90 {
  91         return dev->device_path && !strcmp(dev->device_path, path);
  92 }
  93
  94 static int device_match_uuid(struct discover_device *dev, const char *uuid)
  95 {
  96         return dev->uuid && !strcmp(dev->uuid, uuid);
  97 }
  98
  99 static int device_match_label(struct discover_device *dev, const char *label)
 100 {
 101         return dev->label && !strcmp(dev->label, label);
 102 }
 103
 104 static int device_match_id(struct discover_device *dev, const char *id)
 105 {
 106         return !strcmp(dev->device->id, id);
 107 }
 108
 109 static struct discover_device *device_lookup(
 110                 struct device_handler *device_handler,
 111                 int (match_fn)(struct discover_device *, const char *),
 112                 const char *str)
 113 {
 114         struct discover_device *dev;
 115         unsigned int i;
 116
 117         if (!str)
 118                 return NULL;
 119
 120         for (i = 0; i < device_handler->n_devices; i++) {
 121                 dev = device_handler->devices[i];
 122
 123                 if (match_fn(dev, str))
 124                         return dev;
 125         }
 126
 127         return NULL;
 128 }
 129
 130 struct discover_device *device_lookup_by_name(struct device_handler *handler,
 131                 const char *name)
 132 {
 133         struct discover_device *dev;
 134         char *path;
 135
 136         if (strncmp(name, "/dev/", strlen("/dev/")))
 137                 path = talloc_asprintf(NULL, "/dev/%s", name);
 138         else
 139                 path = talloc_strdup(NULL, name);
 140
 141         dev = device_lookup_by_path(handler, path);
 142
 143         talloc_free(path);
 144
 145         return dev;
 146 }
 147
 148 struct discover_device *device_lookup_by_path(
 149                 struct device_handler *device_handler,
 150                 const char *path)
 151 {
 152         return device_lookup(device_handler, device_match_path, path);
 153 }
 154
 155 struct discover_device *device_lookup_by_uuid(
 156                 struct device_handler *device_handler,
 157                 const char *uuid)
 158 {
 159         return device_lookup(device_handler, device_match_uuid, uuid);
 160 }
 161
 162 struct discover_device *device_lookup_by_label(
 163                 struct device_handler *device_handler,
 164                 const char *label)
 165 {
 166         return device_lookup(device_handler, device_match_label, label);
 167 }
 168
 169 struct discover_device *device_lookup_by_id(
 170                 struct device_handler *device_handler,
 171                 const char *id)
 172 {
 173         return device_lookup(device_handler, device_match_id, id);
 174 }
 175
 176 void device_handler_destroy(struct device_handler *handler)
 177 {
 178         talloc_free(handler);
 179 }
 180
 181 #ifdef PETITBOOT_TEST
 182
 183 /* we have a simplified interface for petitboot testing, but still want
 184  * to keep struct device_handler opaque. */
 185 struct device_handler *device_handler_init(
 186                 struct discover_server *server __attribute__((unused)),
 187                 struct waitset *waitset __attribute__((unused)),
 188                 int dry_run __attribute__((unused)))
 189 {
 190         struct device_handler *handler;
 191
 192         handler = talloc_zero(NULL, struct device_handler);
 193         list_init(&handler->unresolved_boot_options);
 194
 195         return handler;
 196 }
 197
 198 void device_handler_add_device(struct device_handler *handler,
 199                 struct discover_device *dev)
 200 {
 201         handler->n_devices++;
 202         handler->devices = talloc_realloc(handler, handler->devices,
 203                 struct discover_device *, handler->n_devices);
 204         handler->devices[handler->n_devices - 1] = dev;
 205 }
 206
 207 #else
 208
 209 static int mount_device(struct discover_device *dev)
 210 {
 211         int rc;
 212
 213         if (!dev->device_path)
 214                 return -1;
 215
 216         if (!dev->mount_path)
 217                 dev->mount_path = join_paths(dev, mount_base(),
 218                                                 dev->device_path);
 219
 220         if (pb_mkdir_recursive(dev->mount_path))
 221                 pb_log("couldn't create mount directory %s: %s\n",
 222                                 dev->mount_path, strerror(errno));
 223
 224         rc = process_run_simple(dev, pb_system_apps.mount,
 225                         dev->device_path, dev->mount_path,
 226                         "-o", "ro", NULL);
 227
 228         if (!rc)
 229                 return 0;
 230
 231         /* Retry mount without ro option. */
 232         rc = process_run_simple(dev, pb_system_apps.mount,
 233                         dev->device_path, dev->mount_path, NULL);
 234
 235         if (!rc)
 236                 return 0;
 237
 238         pb_rmdir_recursive(mount_base(), dev->mount_path);
 239         return -1;
 240 }
 241
 242 static int umount_device(struct discover_device *dev)
 243 {
 244         int status;
 245
 246         if (!dev->mount_path)
 247                 return 0;
 248
 249         status = process_run_simple(dev, pb_system_apps.umount,
 250                         dev->mount_path, NULL);
 251
 252         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
 253                 return -1;
 254
 255         pb_rmdir_recursive(mount_base(), dev->mount_path);
 256
 257         return 0;
 258 }
 259
 260 struct device_handler *device_handler_init(struct discover_server *server,
 261                 struct waitset *waitset, int dry_run)
 262 {
 263         struct device_handler *handler;
 264
 265         handler = talloc(NULL, struct device_handler);
 266         handler->devices = NULL;
 267         handler->n_devices = 0;
 268         handler->server = server;
 269         handler->waitset = waitset;
 270         handler->dry_run = dry_run;
 271         handler->default_boot_option = NULL;
 272         handler->autoboot_enabled = config_get()->autoboot_enabled;
 273         list_init(&handler->unresolved_boot_options);
 274
 275         /* set up our mount point base */
 276         pb_mkdir_recursive(mount_base());
 277
 278         parser_init();
 279
 280         return handler;
 281 }
 282
 283 static int destroy_device(void *arg)
 284 {
 285         struct discover_device *dev = arg;
 286
 287         umount_device(dev);
 288
 289         return 0;
 290 }
 291
 292 static struct discover_device *find_device(struct device_handler *handler,
 293                 const char *id)
 294 {
 295         struct discover_device *dev;
 296         unsigned int i;
 297
 298         for (i = 0; i < handler->n_devices; i++) {
 299                 dev = handler->devices[i];
 300                 if (!strcmp(dev->device->id, id))
 301                         return dev;
 302         }
 303
 304         return NULL;
 305 }
 306
 307 static enum device_type event_device_type(struct device *device,
 308                 struct event *event)
 309 {
 310         const char *param;
 311
 312         param = event_get_param(event, "type");
 313         if (!param) {
 314                 pb_log("%s: empty type\n", device->id);
 315                 return DEVICE_TYPE_UNKNOWN;
 316         }
 317
 318         if (!strcmp(param, "disk") || !strcmp(param, "partition"))
 319                 return DEVICE_TYPE_DISK;
 320
 321         if (!strcmp(param, "net"))
 322                 return DEVICE_TYPE_NETWORK;
 323
 324         pb_log("%s: unknown type '%s'\n", device->id, param);
 325         return DEVICE_TYPE_UNKNOWN;
 326 }
 327
 328 static struct discover_device *discover_device_create(
 329                 struct device_handler *handler,
 330                 struct discover_context *ctx,
 331                 struct event *event)
 332 {
 333         struct discover_device *dev;
 334         const char *devname;
 335
 336         dev = find_device(handler, event->device);
 337         if (dev)
 338                 return dev;
 339
 340         dev = talloc_zero(ctx, struct discover_device);
 341         dev->device = talloc_zero(dev, struct device);
 342         list_init(&dev->boot_options);
 343
 344         devname = event_get_param(ctx->event, "DEVNAME");
 345         if (devname)
 346                 dev->device_path = talloc_strdup(dev, devname);
 347
 348         dev->device->id = talloc_strdup(dev, event->device);
 349         dev->device->type = event_device_type(dev->device, event);
 350
 351         talloc_set_destructor(dev, destroy_device);
 352
 353         return dev;
 354 }
 355
 356 /**
 357  * device_handler_remove - Remove a device from the handler device array.
 358  */
 359
 360 static void device_handler_remove(struct device_handler *handler,
 361         struct discover_device *device)
 362 {
 363         unsigned int i;
 364
 365         for (i = 0; i < handler->n_devices; i++)
 366                 if (handler->devices[i] == device)
 367                         break;
 368
 369         if (i == handler->n_devices) {
 370                 assert(0 && "unknown device");
 371                 return;
 372         }
 373
 374         handler->n_devices--;
 375         memmove(&handler->devices[i], &handler->devices[i + 1],
 376                 (handler->n_devices - i) * sizeof(handler->devices[0]));
 377         handler->devices = talloc_realloc(handler, handler->devices,
 378                 struct discover_device *, handler->n_devices);
 379
 380         discover_server_notify_device_remove(handler->server, device->device);
 381
 382         talloc_free(device);
 383 }
 384
 385 static void boot_status(void *arg, struct boot_status *status)
 386 {
 387         struct device_handler *handler = arg;
 388
 389         discover_server_notify_boot_status(handler->server, status);
 390 }
 391
 392 static void countdown_status(struct device_handler *handler,
 393                 struct discover_boot_option *opt, unsigned int sec)
 394 {
 395         struct boot_status status;
 396
 397         status.type = BOOT_STATUS_INFO;
 398         status.progress = -1;
 399         status.detail = NULL;
 400         status.message = talloc_asprintf(handler,
 401                         "Booting %s in %u sec", opt->option->name, sec);
 402
 403         discover_server_notify_boot_status(handler->server, &status);
 404
 405         talloc_free(status.message);
 406 }
 407
 408 static int default_timeout(void *arg)
 409 {
 410         struct device_handler *handler = arg;
 411         struct discover_boot_option *opt;
 412
 413         if (!handler->default_boot_option)
 414                 return 0;
 415
 416         opt = handler->default_boot_option;
 417
 418         if (handler->sec_to_boot) {
 419                 countdown_status(handler, opt, handler->sec_to_boot);
 420                 handler->sec_to_boot--;
 421                 handler->timeout_waiter = waiter_register_timeout(
 422                                                 handler->waitset, 1000,
 423                                                 default_timeout, handler);
 424                 return 0;
 425         }
 426
 427         pb_log("Timeout expired, booting default option %s\n", opt->option->id);
 428
 429         boot(handler, handler->default_boot_option, NULL,
 430                         handler->dry_run, boot_status, handler);
 431         return 0;
 432 }
 433
 434 static void set_default(struct device_handler *handler,
 435                 struct discover_boot_option *opt)
 436 {
 437         if (handler->default_boot_option)
 438                 return;
 439
 440         if (!handler->autoboot_enabled)
 441                 return;
 442
 443         handler->default_boot_option = opt;
 444         handler->sec_to_boot = config_get()->autoboot_timeout_sec;
 445
 446         pb_log("Boot option %s set as default, timeout %u sec.\n",
 447                opt->option->id, handler->sec_to_boot);
 448
 449         default_timeout(handler);
 450 }
 451
 452 static bool resource_is_resolved(struct resource *res)
 453 {
 454         return !res || res->resolved;
 455 }
 456
 457 /* We only use this in an assert, which will disappear if we're compiling
 458  * with NDEBUG, so we need the 'used' attribute for these builds */
 459 static bool __attribute__((used)) boot_option_is_resolved(
 460                 struct discover_boot_option *opt)
 461 {
 462         return resource_is_resolved(opt->boot_image) &&
 463                 resource_is_resolved(opt->initrd) &&
 464                 resource_is_resolved(opt->dtb) &&
 465                 resource_is_resolved(opt->icon);
 466 }
 467
 468 static bool resource_resolve(struct resource *res, const char *name,
 469                 struct discover_boot_option *opt,
 470                 struct device_handler *handler)
 471 {
 472         struct parser *parser = opt->source;
 473
 474         if (resource_is_resolved(res))
 475                 return true;
 476
 477         pb_log("Attempting to resolve resource %s->%s with parser %s\n",
 478                         opt->option->id, name, parser->name);
 479         parser->resolve_resource(handler, res);
 480
 481         return res->resolved;
 482 }
 483
 484 static bool boot_option_resolve(struct discover_boot_option *opt,
 485                 struct device_handler *handler)
 486 {
 487         return resource_resolve(opt->boot_image, "boot_image", opt, handler) &&
 488                 resource_resolve(opt->initrd, "initrd", opt, handler) &&
 489                 resource_resolve(opt->dtb, "dtb", opt, handler) &&
 490                 resource_resolve(opt->icon, "icon", opt, handler);
 491 }
 492
 493 static void boot_option_finalise(struct device_handler *handler,
 494                 struct discover_boot_option *opt)
 495 {
 496         assert(boot_option_is_resolved(opt));
 497
 498         /* check that the parsers haven't set any of the final data */
 499         assert(!opt->option->boot_image_file);
 500         assert(!opt->option->initrd_file);
 501         assert(!opt->option->dtb_file);
 502         assert(!opt->option->icon_file);
 503         assert(!opt->option->device_id);
 504
 505         if (opt->boot_image)
 506                 opt->option->boot_image_file = opt->boot_image->url->full;
 507         if (opt->initrd)
 508                 opt->option->initrd_file = opt->initrd->url->full;
 509         if (opt->dtb)
 510                 opt->option->dtb_file = opt->dtb->url->full;
 511         if (opt->icon)
 512                 opt->option->icon_file = opt->icon->url->full;
 513
 514         opt->option->device_id = opt->device->device->id;
 515
 516         if (opt->option->is_default)
 517                 set_default(handler, opt);
 518 }
 519
 520 static void process_boot_option_queue(struct device_handler *handler)
 521 {
 522         struct discover_boot_option *opt, *tmp;
 523
 524         list_for_each_entry_safe(&handler->unresolved_boot_options,
 525                         opt, tmp, list) {
 526
 527                 pb_log("queue: attempting resolution for %s\n",
 528                                 opt->option->id);
 529
 530                 if (!boot_option_resolve(opt, handler))
 531                         continue;
 532
 533                 pb_log("\tresolved!\n");
 534
 535                 list_remove(&opt->list);
 536                 list_add_tail(&opt->device->boot_options, &opt->list);
 537                 talloc_steal(opt->device, opt);
 538                 boot_option_finalise(handler, opt);
 539                 discover_server_notify_boot_option_add(handler->server,
 540                                                         opt->option);
 541         }
 542 }
 543
 544 /**
 545  * context_commit - Commit a temporary discovery context to the handler,
 546  * and notify the clients about any new options / devices
 547  */
 548 static void context_commit(struct device_handler *handler,
 549                 struct discover_context *ctx)
 550 {
 551         struct discover_device *dev = ctx->device;
 552         struct discover_boot_option *opt, *tmp;
 553         unsigned int i, existing_device = 0;
 554
 555         /* do we already have this device? */
 556         for (i = 0; i < handler->n_devices; i++) {
 557                 if (ctx->device == handler->devices[i]) {
 558                         existing_device = 1;
 559                         break;
 560                 }
 561         }
 562
 563         /* if not already present, add the device to the handler's array */
 564         if (!existing_device) {
 565                 handler->n_devices++;
 566                 handler->devices = talloc_realloc(handler, handler->devices,
 567                         struct discover_device *, handler->n_devices);
 568                 handler->devices[handler->n_devices - 1] = dev;
 569                 talloc_steal(handler, dev);
 570
 571                 discover_server_notify_device_add(handler->server, dev->device);
 572
 573                 /* this new device might be able to resolve existing boot
 574                  * options */
 575                 pb_log("New device %s, processing queue\n", dev->device->id);
 576                 process_boot_option_queue(handler);
 577         }
 578
 579
 580         /* move boot options from the context to the device */
 581         list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
 582                 list_remove(&opt->list);
 583
 584                 if (boot_option_resolve(opt, handler)) {
 585                         pb_log("boot option %s is resolved, "
 586                                         "sending to clients\n",
 587                                         opt->option->id);
 588                         list_add_tail(&dev->boot_options, &opt->list);
 589                         talloc_steal(dev, opt);
 590                         boot_option_finalise(handler, opt);
 591                         discover_server_notify_boot_option_add(handler->server,
 592                                                                 opt->option);
 593                 } else {
 594                         if (!opt->source->resolve_resource) {
 595                                 pb_log("parser %s gave us an unresolved "
 596                                         "resource (%s), but no way to "
 597                                         "resolve it\n",
 598                                         opt->source->name, opt->option->id);
 599                                 talloc_free(opt);
 600                         } else {
 601                                 pb_log("boot option %s is unresolved, "
 602                                                 "adding to queue\n",
 603                                                 opt->option->id);
 604                                 list_add(&handler->unresolved_boot_options,
 605                                                 &opt->list);
 606                                 talloc_steal(handler, opt);
 607                         }
 608                 }
 609         }
 610 }
 611
 612 static int handle_add_udev_event(struct device_handler *handler,
 613                 struct event *event)
 614 {
 615         struct discover_context *ctx;
 616         struct discover_device *dev;
 617         const char *param;
 618         int rc;
 619
 620         /* create our context */
 621         ctx = talloc(handler, struct discover_context);
 622         ctx->event = event;
 623         list_init(&ctx->boot_options);
 624
 625         /* create our top-level device */
 626         dev = discover_device_create(handler, ctx, event);
 627
 628         ctx->device = dev;
 629
 630         /* try to parse UUID and labels */
 631         param = event_get_param(ctx->event, "ID_FS_UUID");
 632         if (param)
 633                 dev->uuid = talloc_strdup(dev, param);
 634
 635         param = event_get_param(ctx->event, "ID_FS_LABEL");
 636         if (param)
 637                 dev->label = talloc_strdup(dev, param);
 638
 639         rc = mount_device(dev);
 640         if (rc) {
 641                 talloc_free(ctx);
 642                 return 0;
 643         }
 644
 645         /* run the parsers. This will populate the ctx's boot_option list. */
 646         iterate_parsers(ctx, CONF_METHOD_LOCAL_FILE);
 647
 648         /* add discovered stuff to the handler */
 649         context_commit(handler, ctx);
 650
 651         talloc_free(ctx);
 652
 653         return 0;
 654 }
 655
 656 static int handle_remove_udev_event(struct device_handler *handler,
 657                 struct event *event)
 658 {
 659         struct discover_device *dev;
 660
 661         dev = find_device(handler, event->device);
 662         if (!dev)
 663                 return 0;
 664
 665         /* remove device from handler device array */
 666         device_handler_remove(handler, dev);
 667
 668         return 0;
 669 }
 670
 671 static int handle_add_user_event(struct device_handler *handler,
 672                 struct event *event)
 673 {
 674         struct discover_context *ctx;
 675         struct discover_device *dev;
 676         int rc;
 677
 678         assert(event->device);
 679
 680         ctx = talloc(handler, struct discover_context);
 681         ctx->event = event;
 682         list_init(&ctx->boot_options);
 683
 684         dev = discover_device_create(handler, ctx, event);
 685         ctx->device = dev;
 686
 687         rc = parse_user_event(ctx, event);
 688
 689         if (!rc)
 690                 context_commit(handler, ctx);
 691
 692         return rc;
 693 }
 694
 695 static int handle_remove_user_event(struct device_handler *handler,
 696                 struct event *event)
 697 {
 698         struct discover_device *dev = find_device(handler, event->device);
 699
 700         if (!dev)
 701                 return 0;
 702
 703         /* remove device from handler device array */
 704         device_handler_remove(handler, dev);
 705
 706         return 0;
 707 }
 708
 709 static enum conf_method parse_conf_method(const char *str)
 710 {
 711
 712         if (!strcasecmp(str, "dhcp")) {
 713                 return CONF_METHOD_DHCP;
 714         }
 715         return CONF_METHOD_UNKNOWN;
 716 }
 717
 718 static int handle_conf_user_event(struct device_handler *handler,
 719                 struct event *event)
 720 {
 721         struct discover_context *ctx;
 722         struct discover_device *dev;
 723         enum conf_method method;
 724         const char *val;
 725
 726         ctx = talloc(handler, struct discover_context);
 727         ctx->event = event;
 728         list_init(&ctx->boot_options);
 729
 730         val = event_get_param(event, "url");
 731         if (!val) {
 732                 talloc_free(ctx);
 733                 return 0;
 734         }
 735
 736         ctx->conf_url = pb_url_parse(ctx, val);
 737         if (!ctx->conf_url) {
 738                 talloc_free(ctx);
 739                 return 0;
 740         }
 741
 742         val = event_get_param(event, "method");
 743         if (!val) {
 744                 talloc_free(ctx);
 745                 return 0;
 746         }
 747
 748         method = parse_conf_method(val);
 749         if (method == CONF_METHOD_UNKNOWN) {
 750                 talloc_free(ctx);
 751                 return 0;
 752         }
 753
 754         dev = discover_device_create(handler, ctx, event);
 755         ctx->device = dev;
 756
 757         iterate_parsers(ctx, method);
 758
 759         context_commit(handler, ctx);
 760
 761         return 0;
 762 }
 763
 764 typedef int (*event_handler)(struct device_handler *, struct event *);
 765
 766 static event_handler handlers[EVENT_TYPE_MAX][EVENT_ACTION_MAX] = {
 767         [EVENT_TYPE_UDEV] = {
 768                 [EVENT_ACTION_ADD]      = handle_add_udev_event,
 769                 [EVENT_ACTION_REMOVE]   = handle_remove_udev_event,
 770         },
 771         [EVENT_TYPE_USER] = {
 772                 [EVENT_ACTION_ADD]      = handle_add_user_event,
 773                 [EVENT_ACTION_REMOVE]   = handle_remove_user_event,
 774                 [EVENT_ACTION_CONF]     = handle_conf_user_event,
 775         }
 776 };
 777
 778 int device_handler_event(struct device_handler *handler,
 779                 struct event *event)
 780 {
 781         if (event->type >= EVENT_TYPE_MAX ||
 782                         event->action >= EVENT_ACTION_MAX ||
 783                         !handlers[event->type][event->action]) {
 784                 pb_log("%s unknown type/action: %d/%d\n", __func__,
 785                                 event->type, event->action);
 786                 return 0;
 787         }
 788
 789         return handlers[event->type][event->action](handler, event);
 790 }
 791
 792 static struct discover_boot_option *find_boot_option_by_id(
 793                 struct device_handler *handler, const char *id)
 794 {
 795         unsigned int i;
 796
 797         for (i = 0; i < handler->n_devices; i++) {
 798                 struct discover_device *dev = handler->devices[i];
 799                 struct discover_boot_option *opt;
 800
 801                 list_for_each_entry(&dev->boot_options, opt, list)
 802                         if (!strcmp(opt->option->id, id))
 803                                 return opt;
 804         }
 805
 806         return NULL;
 807 }
 808
 809 void device_handler_boot(struct device_handler *handler,
 810                 struct boot_command *cmd)
 811 {
 812         struct discover_boot_option *opt;
 813
 814         opt = find_boot_option_by_id(handler, cmd->option_id);
 815
 816         boot(handler, opt, cmd, handler->dry_run, boot_status, handler);
 817 }
 818
 819 void device_handler_cancel_default(struct device_handler *handler)
 820 {
 821         struct boot_status status;
 822
 823         if (handler->timeout_waiter)
 824                 waiter_remove(handler->timeout_waiter);
 825
 826         handler->timeout_waiter = NULL;
 827         handler->autoboot_enabled = false;
 828
 829         /* we only send status if we had a default boot option queued */
 830         if (!handler->default_boot_option)
 831                 return;
 832
 833         pb_log("Cancelling default boot option\n");
 834
 835         handler->default_boot_option = NULL;
 836
 837         status.type = BOOT_STATUS_INFO;
 838         status.progress = -1;
 839         status.detail = NULL;
 840         status.message = "Default boot cancelled";
 841
 842         discover_server_notify_boot_status(handler->server, &status);
 843 }
 844 #endif