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                                 pb_log("boot option %s is unresolved, "
 160                                                 "adding to queue\n",
 161                                                 opt->option->id);
 162                                 list_add(&handler->unresolved_boot_options,
 163                                                 &opt->list);
 164                                 talloc_steal(handler, opt);
 165                         }
 166                 }
 167         }
 168 }
 169
 170 void discover_context_add_boot_option(struct discover_context *ctx,
 171                 struct discover_boot_option *boot_option)
 172 {
 173         boot_option->source = ctx->parser;
 174         list_add_tail(&ctx->boot_options, &boot_option->list);
 175         talloc_steal(ctx, boot_option);
 176 }
 177
 178 /**
 179  * device_handler_remove - Remove a device from the handler device array.
 180  */
 181
 182 static void device_handler_remove(struct device_handler *handler,
 183         struct discover_device *device)
 184 {
 185         unsigned int i;
 186
 187         for (i = 0; i < handler->n_devices; i++)
 188                 if (handler->devices[i] == device)
 189                         break;
 190
 191         if (i == handler->n_devices) {
 192                 assert(0 && "unknown device");
 193                 return;
 194         }
 195
 196         handler->n_devices--;
 197         memmove(&handler->devices[i], &handler->devices[i + 1],
 198                 (handler->n_devices - i) * sizeof(handler->devices[0]));
 199         handler->devices = talloc_realloc(handler, handler->devices,
 200                 struct discover_device *, handler->n_devices);
 201
 202         discover_server_notify_device_remove(handler->server, device->device);
 203
 204         talloc_free(device);
 205 }
 206
 207 /**
 208  * device_handler_get_device_count - Get the count of current handler devices.
 209  */
 210
 211 int device_handler_get_device_count(const struct device_handler *handler)
 212 {
 213         return handler->n_devices;
 214 }
 215
 216 /**
 217  * device_handler_get_device - Get a handler device by index.
 218  */
 219
 220 const struct discover_device *device_handler_get_device(
 221         const struct device_handler *handler, unsigned int index)
 222 {
 223         if (index >= handler->n_devices) {
 224                 assert(0 && "bad index");
 225                 return NULL;
 226         }
 227
 228         return handler->devices[index];
 229 }
 230
 231 static int mount_device(struct discover_device *dev)
 232 {
 233         const char *argv[6];
 234
 235         if (!dev->mount_path)
 236                 dev->mount_path = join_paths(dev, mount_base(),
 237                                                 dev->device_path);
 238
 239         if (pb_mkdir_recursive(dev->mount_path))
 240                 pb_log("couldn't create mount directory %s: %s\n",
 241                                 dev->mount_path, strerror(errno));
 242
 243         argv[0] = pb_system_apps.mount;
 244         argv[1] = dev->device_path;
 245         argv[2] = dev->mount_path;
 246         argv[3] = "-o";
 247         argv[4] = "ro";
 248         argv[5] = NULL;
 249
 250         if (pb_run_cmd(argv, 1, 0)) {
 251
 252                 /* Retry mount without ro option. */
 253
 254                 argv[0] = pb_system_apps.mount;
 255                 argv[1] = dev->device_path;
 256                 argv[2] = dev->mount_path;
 257                 argv[3] = NULL;
 258
 259                 if (pb_run_cmd(argv, 1, 0))
 260                         goto out_rmdir;
 261         }
 262
 263         return 0;
 264
 265 out_rmdir:
 266         pb_rmdir_recursive(mount_base(), dev->mount_path);
 267         return -1;
 268 }
 269
 270 static int umount_device(struct discover_device *dev)
 271 {
 272         int status;
 273         pid_t pid;
 274
 275         if (!dev->mount_path)
 276                 return 0;
 277
 278         pid = fork();
 279         if (pid == -1) {
 280                 pb_log("%s: fork failed: %s\n", __func__, strerror(errno));
 281                 return -1;
 282         }
 283
 284         if (pid == 0) {
 285                 execl(pb_system_apps.umount, pb_system_apps.umount,
 286                                                 dev->mount_path, NULL);
 287                 exit(EXIT_FAILURE);
 288         }
 289
 290         if (waitpid(pid, &status, 0) == -1) {
 291                 pb_log("%s: waitpid failed: %s\n", __func__,
 292                                 strerror(errno));
 293                 return -1;
 294         }
 295
 296         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
 297                 return -1;
 298
 299         pb_rmdir_recursive(mount_base(), dev->mount_path);
 300
 301         return 0;
 302 }
 303
 304 static struct discover_device *find_device(struct device_handler *handler,
 305                 const char *id)
 306 {
 307         struct discover_device *dev;
 308         unsigned int i;
 309
 310         for (i = 0; i < handler->n_devices; i++) {
 311                 dev = handler->devices[i];
 312                 if (!strcmp(dev->device->id, id))
 313                         return dev;
 314         }
 315
 316         return NULL;
 317 }
 318
 319 static int destroy_device(void *arg)
 320 {
 321         struct discover_device *dev = arg;
 322
 323         umount_device(dev);
 324
 325         return 0;
 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 struct discover_boot_option *discover_boot_option_create(
 356                 struct discover_context *ctx,
 357                 struct discover_device *device)
 358 {
 359         struct discover_boot_option *opt;
 360
 361         opt = talloc_zero(ctx, struct discover_boot_option);
 362         opt->option = talloc_zero(opt, struct boot_option);
 363         opt->device = device;
 364
 365         return opt;
 366 }
 367
 368
 369 static int handle_add_udev_event(struct device_handler *handler,
 370                 struct event *event)
 371 {
 372         struct discover_context *ctx;
 373         struct discover_device *dev;
 374         const char *param;
 375         int rc;
 376
 377         /* create our context */
 378         ctx = talloc(handler, struct discover_context);
 379         ctx->event = event;
 380         list_init(&ctx->boot_options);
 381
 382         /* create our top-level device */
 383         dev = discover_device_create(handler, ctx, event);
 384
 385         ctx->device = dev;
 386
 387         /* try to parse UUID and labels */
 388         param = event_get_param(ctx->event, "ID_FS_UUID");
 389         if (param)
 390                 dev->uuid = talloc_strdup(dev, param);
 391
 392         param = event_get_param(ctx->event, "ID_FS_LABEL");
 393         if (param)
 394                 dev->label = talloc_strdup(dev, param);
 395
 396         rc = mount_device(dev);
 397         if (rc) {
 398                 talloc_free(ctx);
 399                 return 0;
 400         }
 401
 402         /* run the parsers. This will populate the ctx's boot_option list. */
 403         iterate_parsers(ctx, CONF_METHOD_LOCAL_FILE);
 404
 405         /* add discovered stuff to the handler */
 406         context_commit(handler, ctx);
 407
 408         talloc_free(ctx);
 409
 410         return 0;
 411 }
 412
 413 static int handle_remove_udev_event(struct device_handler *handler,
 414                 struct event *event)
 415 {
 416         struct discover_device *dev;
 417
 418         dev = find_device(handler, event->device);
 419         if (!dev)
 420                 return 0;
 421
 422         /* remove device from handler device array */
 423         device_handler_remove(handler, dev);
 424
 425         return 0;
 426 }
 427
 428 static int handle_add_user_event(struct device_handler *handler,
 429                 struct event *event)
 430 {
 431         struct discover_context *ctx;
 432         struct discover_device *dev;
 433         int rc;
 434
 435         assert(event->device);
 436
 437         ctx = talloc(handler, struct discover_context);
 438         ctx->event = event;
 439         list_init(&ctx->boot_options);
 440
 441         dev = discover_device_create(handler, ctx, event);
 442         ctx->device = dev;
 443
 444         rc = parse_user_event(ctx, event);
 445
 446         if (!rc)
 447                 context_commit(handler, ctx);
 448
 449         return rc;
 450 }
 451
 452 static int handle_remove_user_event(struct device_handler *handler,
 453                 struct event *event)
 454 {
 455         struct discover_device *dev = find_device(handler, event->device);
 456
 457         if (!dev)
 458                 return 0;
 459
 460         /* remove device from handler device array */
 461         device_handler_remove(handler, dev);
 462
 463         return 0;
 464 }
 465
 466 static enum conf_method parse_conf_method(const char *str)
 467 {
 468
 469         if (!strcasecmp(str, "dhcp")) {
 470                 return CONF_METHOD_DHCP;
 471         }
 472         return CONF_METHOD_UNKNOWN;
 473 }
 474
 475 static int handle_conf_user_event(struct device_handler *handler,
 476                 struct event *event)
 477 {
 478         struct discover_context *ctx;
 479         struct discover_device *dev;
 480         enum conf_method method;
 481         const char *val;
 482
 483         ctx = talloc(handler, struct discover_context);
 484         ctx->event = event;
 485         list_init(&ctx->boot_options);
 486
 487         val = event_get_param(event, "url");
 488         if (!val) {
 489                 talloc_free(ctx);
 490                 return 0;
 491         }
 492
 493         ctx->conf_url = pb_url_parse(ctx, val);
 494         if (!ctx->conf_url) {
 495                 talloc_free(ctx);
 496                 return 0;
 497         }
 498
 499         val = event_get_param(event, "method");
 500         if (!val) {
 501                 talloc_free(ctx);
 502                 return 0;
 503         }
 504
 505         method = parse_conf_method(val);
 506         if (method == CONF_METHOD_UNKNOWN) {
 507                 talloc_free(ctx);
 508                 return 0;
 509         }
 510
 511         dev = discover_device_create(handler, ctx, event);
 512         ctx->device = dev;
 513
 514         iterate_parsers(ctx, method);
 515
 516         context_commit(handler, ctx);
 517
 518         return 0;
 519 }
 520
 521 typedef int (*event_handler)(struct device_handler *, struct event *);
 522
 523 static event_handler handlers[EVENT_TYPE_MAX][EVENT_ACTION_MAX] = {
 524         [EVENT_TYPE_UDEV] = {
 525                 [EVENT_ACTION_ADD]      = handle_add_udev_event,
 526                 [EVENT_ACTION_REMOVE]   = handle_remove_udev_event,
 527         },
 528         [EVENT_TYPE_USER] = {
 529                 [EVENT_ACTION_ADD]      = handle_add_user_event,
 530                 [EVENT_ACTION_REMOVE]   = handle_remove_user_event,
 531                 [EVENT_ACTION_CONF]     = handle_conf_user_event,
 532         }
 533 };
 534
 535 int device_handler_event(struct device_handler *handler,
 536                 struct event *event)
 537 {
 538         if (event->type >= EVENT_TYPE_MAX ||
 539                         event->action >= EVENT_ACTION_MAX ||
 540                         !handlers[event->type][event->action]) {
 541                 pb_log("%s unknown type/action: %d/%d\n", __func__,
 542                                 event->type, event->action);
 543                 return 0;
 544         }
 545
 546         return handlers[event->type][event->action](handler, event);
 547 }
 548
 549 struct device_handler *device_handler_init(struct discover_server *server,
 550                 int dry_run)
 551 {
 552         struct device_handler *handler;
 553
 554         handler = talloc(NULL, struct device_handler);
 555         handler->devices = NULL;
 556         handler->n_devices = 0;
 557         handler->server = server;
 558         handler->dry_run = dry_run;
 559         list_init(&handler->unresolved_boot_options);
 560
 561         /* set up our mount point base */
 562         pb_mkdir_recursive(mount_base());
 563
 564         parser_init();
 565
 566         return handler;
 567 }
 568
 569 void device_handler_destroy(struct device_handler *handler)
 570 {
 571         talloc_free(handler);
 572 }
 573
 574 static int device_match_path(struct discover_device *dev, const char *path)
 575 {
 576         return !strcmp(dev->device_path, path);
 577 }
 578
 579 static int device_match_uuid(struct discover_device *dev, const char *uuid)
 580 {
 581         return dev->uuid && !strcmp(dev->uuid, uuid);
 582 }
 583
 584 static int device_match_label(struct discover_device *dev, const char *label)
 585 {
 586         return dev->label && !strcmp(dev->label, label);
 587 }
 588
 589 static int device_match_id(struct discover_device *dev, const char *id)
 590 {
 591         return !strcmp(dev->device->id, id);
 592 }
 593
 594 static struct discover_device *device_lookup(
 595                 struct device_handler *device_handler,
 596                 int (match_fn)(struct discover_device *, const char *),
 597                 const char *str)
 598 {
 599         struct discover_device *dev;
 600         unsigned int i;
 601
 602         if (!str)
 603                 return NULL;
 604
 605         for (i = 0; i < device_handler->n_devices; i++) {
 606                 dev = device_handler->devices[i];
 607
 608                 if (match_fn(dev, str))
 609                         return dev;
 610         }
 611
 612         return NULL;
 613 }
 614
 615 struct discover_device *device_lookup_by_name(struct device_handler *handler,
 616                 const char *name)
 617 {
 618         struct discover_device *dev;
 619         char *path;
 620
 621         if (strncmp(name, "/dev/", strlen("/dev/")))
 622                 path = talloc_asprintf(NULL, "/dev/%s", name);
 623         else
 624                 path = talloc_strdup(NULL, name);
 625
 626         dev = device_lookup_by_path(handler, path);
 627
 628         talloc_free(path);
 629
 630         return dev;
 631 }
 632
 633 struct discover_device *device_lookup_by_path(
 634                 struct device_handler *device_handler,
 635                 const char *path)
 636 {
 637         return device_lookup(device_handler, device_match_path, path);
 638 }
 639
 640 struct discover_device *device_lookup_by_uuid(
 641                 struct device_handler *device_handler,
 642                 const char *uuid)
 643 {
 644         return device_lookup(device_handler, device_match_uuid, uuid);
 645 }
 646
 647 struct discover_device *device_lookup_by_label(
 648                 struct device_handler *device_handler,
 649                 const char *label)
 650 {
 651         return device_lookup(device_handler, device_match_label, label);
 652 }
 653
 654 struct discover_device *device_lookup_by_id(
 655                 struct device_handler *device_handler,
 656                 const char *id)
 657 {
 658         return device_lookup(device_handler, device_match_id, id);
 659 }
 660
 661 static struct discover_boot_option *find_boot_option_by_id(
 662                 struct device_handler *handler, const char *id)
 663 {
 664         unsigned int i;
 665
 666         for (i = 0; i < handler->n_devices; i++) {
 667                 struct discover_device *dev = handler->devices[i];
 668                 struct discover_boot_option *opt;
 669
 670                 list_for_each_entry(&dev->boot_options, opt, list)
 671                         if (!strcmp(opt->option->id, id))
 672                                 return opt;
 673         }
 674
 675         return NULL;
 676 }
 677
 678 static void boot_status(void *arg, struct boot_status *status)
 679 {
 680         struct device_handler *handler = arg;
 681
 682         discover_server_notify_boot_status(handler->server, status);
 683 }
 684
 685 void device_handler_boot(struct device_handler *handler,
 686                 struct boot_command *cmd)
 687 {
 688         struct discover_boot_option *opt;
 689
 690         opt = find_boot_option_by_id(handler, cmd->option_id);
 691
 692         boot(handler, opt, cmd, handler->dry_run, boot_status, handler);
 693 }