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