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