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