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