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->mount_path)
 239                 dev->mount_path = join_paths(dev, mount_base(),
 240                                                 dev->device_path);
 241
 242         if (pb_mkdir_recursive(dev->mount_path))
 243                 pb_log("couldn't create mount directory %s: %s\n",
 244                                 dev->mount_path, strerror(errno));
 245
 246         argv[0] = pb_system_apps.mount;
 247         argv[1] = dev->device_path;
 248         argv[2] = dev->mount_path;
 249         argv[3] = "-o";
 250         argv[4] = "ro";
 251         argv[5] = NULL;
 252
 253         if (pb_run_cmd(argv, 1, 0)) {
 254
 255                 /* Retry mount without ro option. */
 256
 257                 argv[0] = pb_system_apps.mount;
 258                 argv[1] = dev->device_path;
 259                 argv[2] = dev->mount_path;
 260                 argv[3] = NULL;
 261
 262                 if (pb_run_cmd(argv, 1, 0))
 263                         goto out_rmdir;
 264         }
 265
 266         return 0;
 267
 268 out_rmdir:
 269         pb_rmdir_recursive(mount_base(), dev->mount_path);
 270         return -1;
 271 }
 272
 273 static int umount_device(struct discover_device *dev)
 274 {
 275         int status;
 276         pid_t pid;
 277
 278         if (!dev->mount_path)
 279                 return 0;
 280
 281         pid = fork();
 282         if (pid == -1) {
 283                 pb_log("%s: fork failed: %s\n", __func__, strerror(errno));
 284                 return -1;
 285         }
 286
 287         if (pid == 0) {
 288                 execl(pb_system_apps.umount, pb_system_apps.umount,
 289                                                 dev->mount_path, NULL);
 290                 exit(EXIT_FAILURE);
 291         }
 292
 293         if (waitpid(pid, &status, 0) == -1) {
 294                 pb_log("%s: waitpid failed: %s\n", __func__,
 295                                 strerror(errno));
 296                 return -1;
 297         }
 298
 299         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
 300                 return -1;
 301
 302         pb_rmdir_recursive(mount_base(), dev->mount_path);
 303
 304         return 0;
 305 }
 306
 307 static struct discover_device *find_device(struct device_handler *handler,
 308                 const char *id)
 309 {
 310         struct discover_device *dev;
 311         unsigned int i;
 312
 313         for (i = 0; i < handler->n_devices; i++) {
 314                 dev = handler->devices[i];
 315                 if (!strcmp(dev->device->id, id))
 316                         return dev;
 317         }
 318
 319         return NULL;
 320 }
 321
 322 static int destroy_device(void *arg)
 323 {
 324         struct discover_device *dev = arg;
 325
 326         umount_device(dev);
 327
 328         return 0;
 329 }
 330
 331 static struct discover_device *discover_device_create(
 332                 struct device_handler *handler,
 333                 struct discover_context *ctx,
 334                 struct event *event)
 335 {
 336         struct discover_device *dev;
 337         const char *devname;
 338
 339         dev = find_device(handler, event->device);
 340         if (dev)
 341                 return dev;
 342
 343         dev = talloc_zero(ctx, struct discover_device);
 344         dev->device = talloc_zero(dev, struct device);
 345         list_init(&dev->boot_options);
 346
 347         devname = event_get_param(ctx->event, "DEVNAME");
 348         if (devname)
 349                 dev->device_path = talloc_strdup(dev, devname);
 350
 351         dev->device->id = talloc_strdup(dev, event->device);
 352
 353         talloc_set_destructor(dev, destroy_device);
 354
 355         return dev;
 356 }
 357
 358 struct discover_boot_option *discover_boot_option_create(
 359                 struct discover_context *ctx,
 360                 struct discover_device *device)
 361 {
 362         struct discover_boot_option *opt;
 363
 364         opt = talloc_zero(ctx, struct discover_boot_option);
 365         opt->option = talloc_zero(opt, struct boot_option);
 366         opt->device = device;
 367
 368         return opt;
 369 }
 370
 371
 372 static int handle_add_udev_event(struct device_handler *handler,
 373                 struct event *event)
 374 {
 375         struct discover_context *ctx;
 376         struct discover_device *dev;
 377         const char *param;
 378         int rc;
 379
 380         /* create our context */
 381         ctx = talloc(handler, struct discover_context);
 382         ctx->event = event;
 383         list_init(&ctx->boot_options);
 384
 385         /* create our top-level device */
 386         dev = discover_device_create(handler, ctx, event);
 387
 388         ctx->device = dev;
 389
 390         /* try to parse UUID and labels */
 391         param = event_get_param(ctx->event, "ID_FS_UUID");
 392         if (param)
 393                 dev->uuid = talloc_strdup(dev, param);
 394
 395         param = event_get_param(ctx->event, "ID_FS_LABEL");
 396         if (param)
 397                 dev->label = talloc_strdup(dev, param);
 398
 399         rc = mount_device(dev);
 400         if (rc) {
 401                 talloc_free(ctx);
 402                 return 0;
 403         }
 404
 405         /* run the parsers. This will populate the ctx's boot_option list. */
 406         iterate_parsers(ctx, CONF_METHOD_LOCAL_FILE);
 407
 408         /* add discovered stuff to the handler */
 409         context_commit(handler, ctx);
 410
 411         talloc_free(ctx);
 412
 413         return 0;
 414 }
 415
 416 static int handle_remove_udev_event(struct device_handler *handler,
 417                 struct event *event)
 418 {
 419         struct discover_device *dev;
 420
 421         dev = find_device(handler, event->device);
 422         if (!dev)
 423                 return 0;
 424
 425         /* remove device from handler device array */
 426         device_handler_remove(handler, dev);
 427
 428         return 0;
 429 }
 430
 431 static int handle_add_user_event(struct device_handler *handler,
 432                 struct event *event)
 433 {
 434         struct discover_context *ctx;
 435         struct discover_device *dev;
 436         int rc;
 437
 438         assert(event->device);
 439
 440         ctx = talloc(handler, struct discover_context);
 441         ctx->event = event;
 442         list_init(&ctx->boot_options);
 443
 444         dev = discover_device_create(handler, ctx, event);
 445         ctx->device = dev;
 446
 447         rc = parse_user_event(ctx, event);
 448
 449         if (!rc)
 450                 context_commit(handler, ctx);
 451
 452         return rc;
 453 }
 454
 455 static int handle_remove_user_event(struct device_handler *handler,
 456                 struct event *event)
 457 {
 458         struct discover_device *dev = find_device(handler, event->device);
 459
 460         if (!dev)
 461                 return 0;
 462
 463         /* remove device from handler device array */
 464         device_handler_remove(handler, dev);
 465
 466         return 0;
 467 }
 468
 469 static enum conf_method parse_conf_method(const char *str)
 470 {
 471
 472         if (!strcasecmp(str, "dhcp")) {
 473                 return CONF_METHOD_DHCP;
 474         }
 475         return CONF_METHOD_UNKNOWN;
 476 }
 477
 478 static int handle_conf_user_event(struct device_handler *handler,
 479                 struct event *event)
 480 {
 481         struct discover_context *ctx;
 482         struct discover_device *dev;
 483         enum conf_method method;
 484         const char *val;
 485
 486         ctx = talloc(handler, struct discover_context);
 487         ctx->event = event;
 488         list_init(&ctx->boot_options);
 489
 490         val = event_get_param(event, "url");
 491         if (!val) {
 492                 talloc_free(ctx);
 493                 return 0;
 494         }
 495
 496         ctx->conf_url = pb_url_parse(ctx, val);
 497         if (!ctx->conf_url) {
 498                 talloc_free(ctx);
 499                 return 0;
 500         }
 501
 502         val = event_get_param(event, "method");
 503         if (!val) {
 504                 talloc_free(ctx);
 505                 return 0;
 506         }
 507
 508         method = parse_conf_method(val);
 509         if (method == CONF_METHOD_UNKNOWN) {
 510                 talloc_free(ctx);
 511                 return 0;
 512         }
 513
 514         dev = discover_device_create(handler, ctx, event);
 515         ctx->device = dev;
 516
 517         iterate_parsers(ctx, method);
 518
 519         context_commit(handler, ctx);
 520
 521         return 0;
 522 }
 523
 524 typedef int (*event_handler)(struct device_handler *, struct event *);
 525
 526 static event_handler handlers[EVENT_TYPE_MAX][EVENT_ACTION_MAX] = {
 527         [EVENT_TYPE_UDEV] = {
 528                 [EVENT_ACTION_ADD]      = handle_add_udev_event,
 529                 [EVENT_ACTION_REMOVE]   = handle_remove_udev_event,
 530         },
 531         [EVENT_TYPE_USER] = {
 532                 [EVENT_ACTION_ADD]      = handle_add_user_event,
 533                 [EVENT_ACTION_REMOVE]   = handle_remove_user_event,
 534                 [EVENT_ACTION_CONF]     = handle_conf_user_event,
 535         }
 536 };
 537
 538 int device_handler_event(struct device_handler *handler,
 539                 struct event *event)
 540 {
 541         if (event->type >= EVENT_TYPE_MAX ||
 542                         event->action >= EVENT_ACTION_MAX ||
 543                         !handlers[event->type][event->action]) {
 544                 pb_log("%s unknown type/action: %d/%d\n", __func__,
 545                                 event->type, event->action);
 546                 return 0;
 547         }
 548
 549         return handlers[event->type][event->action](handler, event);
 550 }
 551
 552 struct device_handler *device_handler_init(struct discover_server *server,
 553                 int dry_run)
 554 {
 555         struct device_handler *handler;
 556
 557         handler = talloc(NULL, struct device_handler);
 558         handler->devices = NULL;
 559         handler->n_devices = 0;
 560         handler->server = server;
 561         handler->dry_run = dry_run;
 562         list_init(&handler->unresolved_boot_options);
 563
 564         /* set up our mount point base */
 565         pb_mkdir_recursive(mount_base());
 566
 567         parser_init();
 568
 569         return handler;
 570 }
 571
 572 void device_handler_destroy(struct device_handler *handler)
 573 {
 574         talloc_free(handler);
 575 }
 576
 577 static int device_match_path(struct discover_device *dev, const char *path)
 578 {
 579         return !strcmp(dev->device_path, path);
 580 }
 581
 582 static int device_match_uuid(struct discover_device *dev, const char *uuid)
 583 {
 584         return dev->uuid && !strcmp(dev->uuid, uuid);
 585 }
 586
 587 static int device_match_label(struct discover_device *dev, const char *label)
 588 {
 589         return dev->label && !strcmp(dev->label, label);
 590 }
 591
 592 static int device_match_id(struct discover_device *dev, const char *id)
 593 {
 594         return !strcmp(dev->device->id, id);
 595 }
 596
 597 static struct discover_device *device_lookup(
 598                 struct device_handler *device_handler,
 599                 int (match_fn)(struct discover_device *, const char *),
 600                 const char *str)
 601 {
 602         struct discover_device *dev;
 603         unsigned int i;
 604
 605         if (!str)
 606                 return NULL;
 607
 608         for (i = 0; i < device_handler->n_devices; i++) {
 609                 dev = device_handler->devices[i];
 610
 611                 if (match_fn(dev, str))
 612                         return dev;
 613         }
 614
 615         return NULL;
 616 }
 617
 618 struct discover_device *device_lookup_by_name(struct device_handler *handler,
 619                 const char *name)
 620 {
 621         struct discover_device *dev;
 622         char *path;
 623
 624         if (strncmp(name, "/dev/", strlen("/dev/")))
 625                 path = talloc_asprintf(NULL, "/dev/%s", name);
 626         else
 627                 path = talloc_strdup(NULL, name);
 628
 629         dev = device_lookup_by_path(handler, path);
 630
 631         talloc_free(path);
 632
 633         return dev;
 634 }
 635
 636 struct discover_device *device_lookup_by_path(
 637                 struct device_handler *device_handler,
 638                 const char *path)
 639 {
 640         return device_lookup(device_handler, device_match_path, path);
 641 }
 642
 643 struct discover_device *device_lookup_by_uuid(
 644                 struct device_handler *device_handler,
 645                 const char *uuid)
 646 {
 647         return device_lookup(device_handler, device_match_uuid, uuid);
 648 }
 649
 650 struct discover_device *device_lookup_by_label(
 651                 struct device_handler *device_handler,
 652                 const char *label)
 653 {
 654         return device_lookup(device_handler, device_match_label, label);
 655 }
 656
 657 struct discover_device *device_lookup_by_id(
 658                 struct device_handler *device_handler,
 659                 const char *id)
 660 {
 661         return device_lookup(device_handler, device_match_id, id);
 662 }
 663
 664 static struct discover_boot_option *find_boot_option_by_id(
 665                 struct device_handler *handler, const char *id)
 666 {
 667         unsigned int i;
 668
 669         for (i = 0; i < handler->n_devices; i++) {
 670                 struct discover_device *dev = handler->devices[i];
 671                 struct discover_boot_option *opt;
 672
 673                 list_for_each_entry(&dev->boot_options, opt, list)
 674                         if (!strcmp(opt->option->id, id))
 675                                 return opt;
 676         }
 677
 678         return NULL;
 679 }
 680
 681 static void boot_status(void *arg, struct boot_status *status)
 682 {
 683         struct device_handler *handler = arg;
 684
 685         discover_server_notify_boot_status(handler->server, status);
 686 }
 687
 688 void device_handler_boot(struct device_handler *handler,
 689                 struct boot_command *cmd)
 690 {
 691         struct discover_boot_option *opt;
 692
 693         opt = find_boot_option_by_id(handler, cmd->option_id);
 694
 695         boot(handler, opt, cmd, handler->dry_run, boot_status, handler);
 696 }