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