git.ozlabs.org Git - petitboot/blob - discover/device-handler.c

   1 #include <assert.h>
   2 #include <stdlib.h>
   3 #include <stdbool.h>
   4 #include <unistd.h>
   5 #include <string.h>
   6 #include <errno.h>
   7 #include <mntent.h>
   8 #include <locale.h>
   9 #include <sys/stat.h>
  10 #include <sys/wait.h>
  11 #include <sys/mount.h>
  12
  13 #include <talloc/talloc.h>
  14 #include <list/list.h>
  15 #include <log/log.h>
  16 #include <types/types.h>
  17 #include <system/system.h>
  18 #include <process/process.h>
  19 #include <url/url.h>
  20 #include <i18n/i18n.h>
  21
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <netdb.h>
  25 #include <arpa/inet.h>
  26
  27 #include "device-handler.h"
  28 #include "discover-server.h"
  29 #include "devmapper.h"
  30 #include "user-event.h"
  31 #include "platform.h"
  32 #include "event.h"
  33 #include "parser.h"
  34 #include "resource.h"
  35 #include "paths.h"
  36 #include "sysinfo.h"
  37 #include "boot.h"
  38 #include "udev.h"
  39 #include "network.h"
  40 #include "ipmi.h"
  41
  42 enum default_priority {
  43         DEFAULT_PRIORITY_REMOTE         = 1,
  44         DEFAULT_PRIORITY_LOCAL_FIRST    = 2,
  45         DEFAULT_PRIORITY_LOCAL_LAST     = 0xfe,
  46         DEFAULT_PRIORITY_DISABLED       = 0xff,
  47 };
  48
  49 struct device_handler {
  50         struct discover_server  *server;
  51         int                     dry_run;
  52
  53         struct pb_udev          *udev;
  54         struct network          *network;
  55         struct user_event       *user_event;
  56
  57         struct discover_device  **devices;
  58         unsigned int            n_devices;
  59
  60         struct ramdisk_device   **ramdisks;
  61         unsigned int            n_ramdisks;
  62
  63         struct waitset          *waitset;
  64         struct waiter           *timeout_waiter;
  65         bool                    autoboot_enabled;
  66         unsigned int            sec_to_boot;
  67
  68         struct discover_boot_option *default_boot_option;
  69         int                     default_boot_option_priority;
  70
  71         struct list             unresolved_boot_options;
  72
  73         struct boot_task        *pending_boot;
  74         bool                    pending_boot_is_default;
  75 };
  76
  77 static int mount_device(struct discover_device *dev);
  78 static int umount_device(struct discover_device *dev);
  79
  80 static int device_handler_init_sources(struct device_handler *handler);
  81 static void device_handler_reinit_sources(struct device_handler *handler);
  82
  83 static void device_handler_update_lang(const char *lang);
  84
  85 void discover_context_add_boot_option(struct discover_context *ctx,
  86                 struct discover_boot_option *boot_option)
  87 {
  88         boot_option->source = ctx->parser;
  89         list_add_tail(&ctx->boot_options, &boot_option->list);
  90         talloc_steal(ctx, boot_option);
  91 }
  92
  93 /**
  94  * device_handler_get_device_count - Get the count of current handler devices.
  95  */
  96
  97 int device_handler_get_device_count(const struct device_handler *handler)
  98 {
  99         return handler->n_devices;
 100 }
 101
 102 /**
 103  * device_handler_get_device - Get a handler device by index.
 104  */
 105
 106 const struct discover_device *device_handler_get_device(
 107         const struct device_handler *handler, unsigned int index)
 108 {
 109         if (index >= handler->n_devices) {
 110                 assert(0 && "bad index");
 111                 return NULL;
 112         }
 113
 114         return handler->devices[index];
 115 }
 116
 117 struct discover_boot_option *discover_boot_option_create(
 118                 struct discover_context *ctx,
 119                 struct discover_device *device)
 120 {
 121         struct discover_boot_option *opt;
 122
 123         opt = talloc_zero(ctx, struct discover_boot_option);
 124         opt->option = talloc_zero(opt, struct boot_option);
 125         opt->device = device;
 126
 127         return opt;
 128 }
 129
 130 static int device_match_uuid(struct discover_device *dev, const char *uuid)
 131 {
 132         return dev->uuid && !strcmp(dev->uuid, uuid);
 133 }
 134
 135 static int device_match_label(struct discover_device *dev, const char *label)
 136 {
 137         return dev->label && !strcmp(dev->label, label);
 138 }
 139
 140 static int device_match_id(struct discover_device *dev, const char *id)
 141 {
 142         return !strcmp(dev->device->id, id);
 143 }
 144
 145 static int device_match_serial(struct discover_device *dev, const char *serial)
 146 {
 147         const char *val = discover_device_get_param(dev, "ID_SERIAL");
 148         return val && !strcmp(val, serial);
 149 }
 150
 151 static struct discover_device *device_lookup(
 152                 struct device_handler *device_handler,
 153                 int (match_fn)(struct discover_device *, const char *),
 154                 const char *str)
 155 {
 156         struct discover_device *dev;
 157         unsigned int i;
 158
 159         if (!str)
 160                 return NULL;
 161
 162         for (i = 0; i < device_handler->n_devices; i++) {
 163                 dev = device_handler->devices[i];
 164
 165                 if (match_fn(dev, str))
 166                         return dev;
 167         }
 168
 169         return NULL;
 170 }
 171
 172 struct discover_device *device_lookup_by_name(struct device_handler *handler,
 173                 const char *name)
 174 {
 175         if (!strncmp(name, "/dev/", strlen("/dev/")))
 176                 name += strlen("/dev/");
 177
 178         return device_lookup_by_id(handler, name);
 179 }
 180
 181 struct discover_device *device_lookup_by_uuid(
 182                 struct device_handler *device_handler,
 183                 const char *uuid)
 184 {
 185         return device_lookup(device_handler, device_match_uuid, uuid);
 186 }
 187
 188 struct discover_device *device_lookup_by_label(
 189                 struct device_handler *device_handler,
 190                 const char *label)
 191 {
 192         return device_lookup(device_handler, device_match_label, label);
 193 }
 194
 195 struct discover_device *device_lookup_by_id(
 196                 struct device_handler *device_handler,
 197                 const char *id)
 198 {
 199         return device_lookup(device_handler, device_match_id, id);
 200 }
 201
 202 struct discover_device *device_lookup_by_serial(
 203                 struct device_handler *device_handler,
 204                 const char *serial)
 205 {
 206         return device_lookup(device_handler, device_match_serial, serial);
 207 }
 208
 209 void device_handler_destroy(struct device_handler *handler)
 210 {
 211         talloc_free(handler);
 212 }
 213
 214 static int destroy_device(void *arg)
 215 {
 216         struct discover_device *dev = arg;
 217
 218         umount_device(dev);
 219
 220         return 0;
 221 }
 222
 223 struct discover_device *discover_device_create(struct device_handler *handler,
 224                 const char *id)
 225 {
 226         struct discover_device *dev;
 227
 228         dev = device_lookup_by_id(handler, id);
 229         if (dev)
 230                 return dev;
 231
 232         dev = talloc_zero(handler, struct discover_device);
 233         dev->device = talloc_zero(dev, struct device);
 234         dev->device->id = talloc_strdup(dev->device, id);
 235         list_init(&dev->params);
 236         list_init(&dev->boot_options);
 237
 238         talloc_set_destructor(dev, destroy_device);
 239
 240         return dev;
 241 }
 242
 243 struct discover_device_param {
 244         char                    *name;
 245         char                    *value;
 246         struct list_item        list;
 247 };
 248
 249 void discover_device_set_param(struct discover_device *device,
 250                 const char *name, const char *value)
 251 {
 252         struct discover_device_param *param;
 253         bool found = false;
 254
 255         list_for_each_entry(&device->params, param, list) {
 256                 if (!strcmp(param->name, name)) {
 257                         found = true;
 258                         break;
 259                 }
 260         }
 261
 262         if (!found) {
 263                 if (!value)
 264                         return;
 265                 param = talloc(device, struct discover_device_param);
 266                 param->name = talloc_strdup(param, name);
 267                 list_add(&device->params, &param->list);
 268         } else {
 269                 if (!value) {
 270                         list_remove(&param->list);
 271                         talloc_free(param);
 272                         return;
 273                 }
 274                 talloc_free(param->value);
 275         }
 276
 277         param->value = talloc_strdup(param, value);
 278 }
 279
 280 const char *discover_device_get_param(struct discover_device *device,
 281                 const char *name)
 282 {
 283         struct discover_device_param *param;
 284
 285         list_for_each_entry(&device->params, param, list) {
 286                 if (!strcmp(param->name, name))
 287                         return param->value;
 288         }
 289         return NULL;
 290 }
 291
 292 struct device_handler *device_handler_init(struct discover_server *server,
 293                 struct waitset *waitset, int dry_run)
 294 {
 295         struct device_handler *handler;
 296         int rc;
 297
 298         handler = talloc_zero(NULL, struct device_handler);
 299         handler->server = server;
 300         handler->waitset = waitset;
 301         handler->dry_run = dry_run;
 302         handler->autoboot_enabled = config_get()->autoboot_enabled;
 303
 304         list_init(&handler->unresolved_boot_options);
 305
 306         /* set up our mount point base */
 307         pb_mkdir_recursive(mount_base());
 308
 309         parser_init();
 310
 311         if (config_get()->safe_mode)
 312                 return handler;
 313
 314         rc = device_handler_init_sources(handler);
 315         if (rc) {
 316                 talloc_free(handler);
 317                 return NULL;
 318         }
 319
 320         return handler;
 321 }
 322
 323 void device_handler_reinit(struct device_handler *handler)
 324 {
 325         struct discover_boot_option *opt, *tmp;
 326         struct ramdisk_device *ramdisk;
 327         unsigned int i;
 328
 329         device_handler_cancel_default(handler);
 330
 331         /* free unresolved boot options */
 332         list_for_each_entry_safe(&handler->unresolved_boot_options,
 333                         opt, tmp, list)
 334                 talloc_free(opt);
 335         list_init(&handler->unresolved_boot_options);
 336
 337         /* drop all devices */
 338         for (i = 0; i < handler->n_devices; i++) {
 339                 discover_server_notify_device_remove(handler->server,
 340                                 handler->devices[i]->device);
 341                 ramdisk = handler->devices[i]->ramdisk;
 342                 talloc_free(handler->devices[i]);
 343                 talloc_free(ramdisk);
 344         }
 345
 346         talloc_free(handler->devices);
 347         handler->devices = NULL;
 348         handler->n_devices = 0;
 349         talloc_free(handler->ramdisks);
 350         handler->ramdisks = NULL;
 351         handler->n_ramdisks = 0;
 352
 353         device_handler_reinit_sources(handler);
 354 }
 355
 356 void device_handler_remove(struct device_handler *handler,
 357                 struct discover_device *device)
 358 {
 359         struct discover_boot_option *opt, *tmp;
 360         unsigned int i;
 361
 362         list_for_each_entry_safe(&device->boot_options, opt, tmp, list) {
 363                 if (opt == handler->default_boot_option) {
 364                         pb_log("Default option %s cancelled since device removed",
 365                                         opt->option->name);
 366                         device_handler_cancel_default(handler);
 367                         break;
 368                 }
 369         }
 370
 371         for (i = 0; i < handler->n_devices; i++)
 372                 if (handler->devices[i] == device)
 373                         break;
 374
 375         if (i == handler->n_devices) {
 376                 talloc_free(device);
 377                 return;
 378         }
 379
 380         /* Free any unresolved options, as they're currently allocated
 381          * against the handler */
 382         list_for_each_entry_safe(&handler->unresolved_boot_options,
 383                         opt, tmp, list) {
 384                 if (opt->device != device)
 385                         continue;
 386                 list_remove(&opt->list);
 387                 talloc_free(opt);
 388         }
 389
 390         /* if this is a network device, we have to unregister it from the
 391          * network code */
 392         if (device->device->type == DEVICE_TYPE_NETWORK)
 393                 network_unregister_device(handler->network, device);
 394
 395         handler->n_devices--;
 396         memmove(&handler->devices[i], &handler->devices[i + 1],
 397                 (handler->n_devices - i) * sizeof(handler->devices[0]));
 398         handler->devices = talloc_realloc(handler, handler->devices,
 399                 struct discover_device *, handler->n_devices);
 400
 401         if (device->notified)
 402                 discover_server_notify_device_remove(handler->server,
 403                                                         device->device);
 404
 405         talloc_free(device);
 406 }
 407
 408 void device_handler_boot_status(void *arg, struct boot_status *status)
 409 {
 410         struct device_handler *handler = arg;
 411
 412         discover_server_notify_boot_status(handler->server, status);
 413 }
 414
 415 static void countdown_status(struct device_handler *handler,
 416                 struct discover_boot_option *opt, unsigned int sec)
 417 {
 418         struct boot_status status;
 419
 420         status.type = BOOT_STATUS_INFO;
 421         status.progress = -1;
 422         status.detail = NULL;
 423         status.message = talloc_asprintf(handler,
 424                         _("Booting in %d sec: %s"), sec, opt->option->name);
 425
 426         discover_server_notify_boot_status(handler->server, &status);
 427
 428         talloc_free(status.message);
 429 }
 430
 431 static int default_timeout(void *arg)
 432 {
 433         struct device_handler *handler = arg;
 434         struct discover_boot_option *opt;
 435
 436         if (!handler->default_boot_option)
 437                 return 0;
 438
 439         if (handler->pending_boot)
 440                 return 0;
 441
 442         opt = handler->default_boot_option;
 443
 444         if (handler->sec_to_boot) {
 445                 countdown_status(handler, opt, handler->sec_to_boot);
 446                 handler->sec_to_boot--;
 447                 handler->timeout_waiter = waiter_register_timeout(
 448                                                 handler->waitset, 1000,
 449                                                 default_timeout, handler);
 450                 return 0;
 451         }
 452
 453         handler->timeout_waiter = NULL;
 454
 455         pb_log("Timeout expired, booting default option %s\n", opt->option->id);
 456
 457         platform_pre_boot();
 458
 459         handler->pending_boot = boot(handler, handler->default_boot_option,
 460                         NULL, handler->dry_run, device_handler_boot_status,
 461                         handler);
 462         handler->pending_boot_is_default = true;
 463         return 0;
 464 }
 465
 466 struct {
 467         enum ipmi_bootdev       ipmi_type;
 468         enum device_type        device_type;
 469 } device_type_map[] = {
 470         { IPMI_BOOTDEV_NETWORK, DEVICE_TYPE_NETWORK },
 471         { IPMI_BOOTDEV_DISK, DEVICE_TYPE_DISK },
 472         { IPMI_BOOTDEV_DISK, DEVICE_TYPE_USB },
 473         { IPMI_BOOTDEV_CDROM, DEVICE_TYPE_OPTICAL },
 474 };
 475
 476 static bool ipmi_device_type_matches(enum ipmi_bootdev ipmi_type,
 477                 enum device_type device_type)
 478 {
 479         unsigned int i;
 480
 481         for (i = 0; i < ARRAY_SIZE(device_type_map); i++) {
 482                 if (device_type_map[i].device_type == device_type)
 483                         return device_type_map[i].ipmi_type == ipmi_type;
 484         }
 485
 486         return false;
 487 }
 488
 489 static int autoboot_option_priority(const struct config *config,
 490                                 struct discover_boot_option *opt)
 491 {
 492         enum device_type type = opt->device->device->type;
 493         const char *uuid = opt->device->uuid;
 494         struct autoboot_option *auto_opt;
 495         unsigned int i;
 496
 497         for (i = 0; i < config->n_autoboot_opts; i++) {
 498                 auto_opt = &config->autoboot_opts[i];
 499                 if (auto_opt->boot_type == BOOT_DEVICE_UUID)
 500                         if (!strcmp(auto_opt->uuid, uuid))
 501                                 return DEFAULT_PRIORITY_LOCAL_FIRST + i;
 502
 503                 if (auto_opt->boot_type == BOOT_DEVICE_TYPE)
 504                         if (auto_opt->type == type ||
 505                             auto_opt->type == DEVICE_TYPE_ANY)
 506                                 return DEFAULT_PRIORITY_LOCAL_FIRST + i;
 507         }
 508
 509         return -1;
 510 }
 511
 512 /*
 513  * We have different priorities to resolve conflicts between boot options that
 514  * report to be the default for their device. This function assigns a priority
 515  * for these options.
 516  */
 517 static enum default_priority default_option_priority(
 518                 struct discover_boot_option *opt)
 519 {
 520         const struct config *config;
 521
 522         config = config_get();
 523
 524         /* We give highest priority to IPMI-configured boot options. If
 525          * we have an IPMI bootdev configuration set, then we don't allow
 526          * any other defaults */
 527         if (config->ipmi_bootdev) {
 528                 bool ipmi_match = ipmi_device_type_matches(config->ipmi_bootdev,
 529                                 opt->device->device->type);
 530                 if (ipmi_match)
 531                         return DEFAULT_PRIORITY_REMOTE;
 532
 533                 pb_debug("handler: disabled default priority due to "
 534                                 "non-matching IPMI type %x\n",
 535                                 config->ipmi_bootdev);
 536                 return DEFAULT_PRIORITY_DISABLED;
 537         }
 538
 539         /* Next, try to match the option against the user-defined autoboot
 540          * options, either by device UUID or type. */
 541         if (config->n_autoboot_opts) {
 542                 int boot_match = autoboot_option_priority(config, opt);
 543                 if (boot_match > 0)
 544                         return boot_match;
 545         }
 546
 547         /* If the option didn't match any entry in the array, it is disabled */
 548         pb_debug("handler: disabled default priority due to "
 549                         "non-matching UUID or type\n");
 550         return DEFAULT_PRIORITY_DISABLED;
 551 }
 552
 553 static void set_default(struct device_handler *handler,
 554                 struct discover_boot_option *opt)
 555 {
 556         enum default_priority cur_prio, new_prio;
 557
 558         if (!handler->autoboot_enabled)
 559                 return;
 560
 561         pb_debug("handler: new default option: %s\n", opt->option->id);
 562
 563         new_prio = default_option_priority(opt);
 564
 565         /* Anything outside our range prevents a default boot */
 566         if (new_prio >= DEFAULT_PRIORITY_DISABLED)
 567                 return;
 568
 569         pb_debug("handler: calculated priority %d\n", new_prio);
 570
 571         /* Resolve any conflicts: if we have a new default option, it only
 572          * replaces the current if it has a higher priority. */
 573         if (handler->default_boot_option) {
 574
 575                 cur_prio = handler->default_boot_option_priority;
 576
 577                 if (new_prio < cur_prio) {
 578                         pb_log("handler: new prio %d beats "
 579                                         "old prio %d for %s\n",
 580                                         new_prio, cur_prio,
 581                                         handler->default_boot_option
 582                                                 ->option->id);
 583                         handler->default_boot_option = opt;
 584                         handler->default_boot_option_priority = new_prio;
 585                         /* extend the timeout a little, so the user sees some
 586                          * indication of the change */
 587                         handler->sec_to_boot += 2;
 588                 }
 589
 590                 return;
 591         }
 592
 593         handler->sec_to_boot = config_get()->autoboot_timeout_sec;
 594         handler->default_boot_option = opt;
 595         handler->default_boot_option_priority = new_prio;
 596
 597         pb_log("handler: boot option %s set as default, timeout %u sec.\n",
 598                opt->option->id, handler->sec_to_boot);
 599
 600         default_timeout(handler);
 601 }
 602
 603 static bool resource_is_resolved(struct resource *res)
 604 {
 605         return !res || res->resolved;
 606 }
 607
 608 /* We only use this in an assert, which will disappear if we're compiling
 609  * with NDEBUG, so we need the 'used' attribute for these builds */
 610 static bool __attribute__((used)) boot_option_is_resolved(
 611                 struct discover_boot_option *opt)
 612 {
 613         return resource_is_resolved(opt->boot_image) &&
 614                 resource_is_resolved(opt->initrd) &&
 615                 resource_is_resolved(opt->dtb) &&
 616                 resource_is_resolved(opt->args_sig_file) &&
 617                 resource_is_resolved(opt->icon);
 618 }
 619
 620 static bool resource_resolve(struct resource *res, const char *name,
 621                 struct discover_boot_option *opt,
 622                 struct device_handler *handler)
 623 {
 624         struct parser *parser = opt->source;
 625
 626         if (resource_is_resolved(res))
 627                 return true;
 628
 629         pb_debug("Attempting to resolve resource %s->%s with parser %s\n",
 630                         opt->option->id, name, parser->name);
 631         parser->resolve_resource(handler, res);
 632
 633         return res->resolved;
 634 }
 635
 636 static bool boot_option_resolve(struct discover_boot_option *opt,
 637                 struct device_handler *handler)
 638 {
 639         return resource_resolve(opt->boot_image, "boot_image", opt, handler) &&
 640                 resource_resolve(opt->initrd, "initrd", opt, handler) &&
 641                 resource_resolve(opt->dtb, "dtb", opt, handler) &&
 642                 resource_resolve(opt->args_sig_file, "args_sig_file", opt,
 643                         handler) &&
 644                 resource_resolve(opt->icon, "icon", opt, handler);
 645 }
 646
 647 static void boot_option_finalise(struct device_handler *handler,
 648                 struct discover_boot_option *opt)
 649 {
 650         assert(boot_option_is_resolved(opt));
 651
 652         /* check that the parsers haven't set any of the final data */
 653         assert(!opt->option->boot_image_file);
 654         assert(!opt->option->initrd_file);
 655         assert(!opt->option->dtb_file);
 656         assert(!opt->option->icon_file);
 657         assert(!opt->option->device_id);
 658         assert(!opt->option->args_sig_file);
 659
 660         if (opt->boot_image)
 661                 opt->option->boot_image_file = opt->boot_image->url->full;
 662         if (opt->initrd)
 663                 opt->option->initrd_file = opt->initrd->url->full;
 664         if (opt->dtb)
 665                 opt->option->dtb_file = opt->dtb->url->full;
 666         if (opt->icon)
 667                 opt->option->icon_file = opt->icon->url->full;
 668         if (opt->args_sig_file)
 669                 opt->option->args_sig_file = opt->args_sig_file->url->full;
 670
 671         opt->option->device_id = opt->device->device->id;
 672
 673         if (opt->option->is_default)
 674                 set_default(handler, opt);
 675 }
 676
 677 static void notify_boot_option(struct device_handler *handler,
 678                 struct discover_boot_option *opt)
 679 {
 680         struct discover_device *dev = opt->device;
 681
 682         if (!dev->notified)
 683                 discover_server_notify_device_add(handler->server,
 684                                                   opt->device->device);
 685         dev->notified = true;
 686         discover_server_notify_boot_option_add(handler->server, opt->option);
 687 }
 688
 689 static void process_boot_option_queue(struct device_handler *handler)
 690 {
 691         struct discover_boot_option *opt, *tmp;
 692
 693         list_for_each_entry_safe(&handler->unresolved_boot_options,
 694                         opt, tmp, list) {
 695
 696                 pb_debug("queue: attempting resolution for %s\n",
 697                                 opt->option->id);
 698
 699                 if (!boot_option_resolve(opt, handler))
 700                         continue;
 701
 702                 pb_debug("\tresolved!\n");
 703
 704                 list_remove(&opt->list);
 705                 list_add_tail(&opt->device->boot_options, &opt->list);
 706                 talloc_steal(opt->device, opt);
 707                 boot_option_finalise(handler, opt);
 708                 notify_boot_option(handler, opt);
 709         }
 710 }
 711
 712 struct discover_context *device_handler_discover_context_create(
 713                 struct device_handler *handler,
 714                 struct discover_device *device)
 715 {
 716         struct discover_context *ctx;
 717
 718         ctx = talloc_zero(handler, struct discover_context);
 719         ctx->device = device;
 720         ctx->network = handler->network;
 721         list_init(&ctx->boot_options);
 722
 723         return ctx;
 724 }
 725
 726 void device_handler_add_device(struct device_handler *handler,
 727                 struct discover_device *device)
 728 {
 729         handler->n_devices++;
 730         handler->devices = talloc_realloc(handler, handler->devices,
 731                                 struct discover_device *, handler->n_devices);
 732         handler->devices[handler->n_devices - 1] = device;
 733
 734         if (device->device->type == DEVICE_TYPE_NETWORK)
 735                 network_register_device(handler->network, device);
 736 }
 737
 738 void device_handler_add_ramdisk(struct device_handler *handler,
 739                 const char *path)
 740 {
 741         struct ramdisk_device *dev;
 742         unsigned int i;
 743
 744         if (!path)
 745                 return;
 746
 747         for (i = 0; i < handler->n_ramdisks; i++)
 748                 if (!strcmp(handler->ramdisks[i]->path, path))
 749                         return;
 750
 751         dev = talloc_zero(handler, struct ramdisk_device);
 752         if (!dev) {
 753                 pb_log("Failed to allocate memory to track %s\n", path);
 754                 return;
 755         }
 756
 757         dev->path = talloc_strdup(handler, path);
 758
 759         handler->ramdisks = talloc_realloc(handler, handler->ramdisks,
 760                                 struct ramdisk_device *,
 761                                 handler->n_ramdisks + 1);
 762         if (!handler->ramdisks) {
 763                 pb_log("Failed to reallocate memory"
 764                        "- ramdisk tracking inconsistent!\n");
 765                 return;
 766         }
 767
 768         handler->ramdisks[i] = dev;
 769         i = handler->n_ramdisks++;
 770 }
 771
 772 struct ramdisk_device *device_handler_get_ramdisk(
 773                 struct device_handler *handler)
 774 {
 775         unsigned int i;
 776         char *name;
 777         dev_t id;
 778
 779         /* Check if free ramdisk exists */
 780         for (i = 0; i < handler->n_ramdisks; i++)
 781                 if (!handler->ramdisks[i]->snapshot &&
 782                     !handler->ramdisks[i]->origin &&
 783                     !handler->ramdisks[i]->base)
 784                         return handler->ramdisks[i];
 785
 786         /* Otherwise create a new one */
 787         name = talloc_asprintf(handler, "/dev/ram%d",
 788                         handler->n_ramdisks);
 789         if (!name) {
 790                 pb_debug("Failed to allocate memory to name /dev/ram%d",
 791                         handler->n_ramdisks);
 792                 return NULL;
 793         }
 794
 795         id = makedev(1, handler->n_ramdisks);
 796         if (mknod(name, S_IFBLK, id)) {
 797                 if (errno == EEXIST) {
 798                         /* We haven't yet received updates for existing
 799                          * ramdisks - add and use this one */
 800                         pb_debug("Using untracked ramdisk %s\n", name);
 801                 } else {
 802                         pb_log("Failed to create new ramdisk %s: %s\n",
 803                                name, strerror(errno));
 804                         return NULL;
 805                 }
 806         }
 807         device_handler_add_ramdisk(handler, name);
 808         talloc_free(name);
 809
 810         return handler->ramdisks[i];
 811 }
 812
 813 void device_handler_release_ramdisk(struct discover_device *device)
 814 {
 815         struct ramdisk_device *ramdisk = device->ramdisk;
 816
 817         talloc_free(ramdisk->snapshot);
 818         talloc_free(ramdisk->origin);
 819         talloc_free(ramdisk->base);
 820
 821         ramdisk->snapshot = ramdisk->origin = ramdisk->base = NULL;
 822         ramdisk->sectors = 0;
 823
 824         device->ramdisk = NULL;
 825 }
 826
 827 /* Start discovery on a hotplugged device. The device will be in our devices
 828  * array, but has only just been initialised by the hotplug source.
 829  */
 830 int device_handler_discover(struct device_handler *handler,
 831                 struct discover_device *dev)
 832 {
 833         struct discover_context *ctx;
 834         struct boot_status *status;
 835         int rc;
 836
 837         status = talloc_zero(handler, struct boot_status);
 838         status->type = BOOT_STATUS_INFO;
 839         /*
 840          * TRANSLATORS: this string will be passed the type and identifier
 841          * of the device. For example, the first parameter could be "Disk",
 842          * (which will be translated accordingly) and the second a Linux device
 843          * identifier like 'sda1' (which will not be translated)
 844          */
 845         status->message = talloc_asprintf(status, _("Processing %s device %s"),
 846                                 device_type_display_name(dev->device->type),
 847                                 dev->device->id);
 848         device_handler_boot_status(handler, status);
 849
 850         process_boot_option_queue(handler);
 851
 852         /* create our context */
 853         ctx = device_handler_discover_context_create(handler, dev);
 854
 855         rc = mount_device(dev);
 856         if (rc)
 857                 goto out;
 858
 859         /* add this device to our system info */
 860         system_info_register_blockdev(dev->device->id, dev->uuid,
 861                         dev->mount_path);
 862
 863         /* run the parsers. This will populate the ctx's boot_option list. */
 864         iterate_parsers(ctx);
 865
 866         /* add discovered stuff to the handler */
 867         device_handler_discover_context_commit(handler, ctx);
 868
 869 out:
 870         /*
 871          * TRANSLATORS: the format specifier in this string is a Linux
 872          * device identifier, like 'sda1'
 873          */
 874         status->message = talloc_asprintf(status,_("Processing %s complete"),
 875                                 dev->device->id);
 876         device_handler_boot_status(handler, status);
 877
 878         talloc_free(status);
 879         talloc_unlink(handler, ctx);
 880
 881         return 0;
 882 }
 883
 884 /* Incoming dhcp event */
 885 int device_handler_dhcp(struct device_handler *handler,
 886                 struct discover_device *dev, struct event *event)
 887 {
 888         struct discover_context *ctx;
 889         struct boot_status *status;
 890
 891         status = talloc_zero(handler, struct boot_status);
 892         status->type = BOOT_STATUS_INFO;
 893         /*
 894          * TRANSLATORS: this format specifier will be the name of a network
 895          * device, like 'eth0'.
 896          */
 897         status->message = talloc_asprintf(status, _("Processing dhcp event on %s"),
 898                                 dev->device->id);
 899         device_handler_boot_status(handler, status);
 900
 901         /* create our context */
 902         ctx = device_handler_discover_context_create(handler, dev);
 903         talloc_steal(ctx, event);
 904         ctx->event = event;
 905
 906         iterate_parsers(ctx);
 907
 908         device_handler_discover_context_commit(handler, ctx);
 909
 910         /*
 911          * TRANSLATORS: this format specifier will be the name of a network
 912          * device, like 'eth0'.
 913          */
 914         status->message = talloc_asprintf(status,_("Processing %s complete"),
 915                                 dev->device->id);
 916         device_handler_boot_status(handler, status);
 917
 918         talloc_free(status);
 919         talloc_unlink(handler, ctx);
 920
 921         return 0;
 922 }
 923
 924 static struct discover_boot_option *find_boot_option_by_id(
 925                 struct device_handler *handler, const char *id)
 926 {
 927         unsigned int i;
 928
 929         for (i = 0; i < handler->n_devices; i++) {
 930                 struct discover_device *dev = handler->devices[i];
 931                 struct discover_boot_option *opt;
 932
 933                 list_for_each_entry(&dev->boot_options, opt, list)
 934                         if (!strcmp(opt->option->id, id))
 935                                 return opt;
 936         }
 937
 938         return NULL;
 939 }
 940
 941 void device_handler_boot(struct device_handler *handler,
 942                 struct boot_command *cmd)
 943 {
 944         struct discover_boot_option *opt = NULL;
 945
 946         if (cmd->option_id && strlen(cmd->option_id))
 947                 opt = find_boot_option_by_id(handler, cmd->option_id);
 948
 949         if (handler->pending_boot)
 950                 boot_cancel(handler->pending_boot);
 951
 952         platform_pre_boot();
 953
 954         handler->pending_boot = boot(handler, opt, cmd, handler->dry_run,
 955                         device_handler_boot_status, handler);
 956         handler->pending_boot_is_default = false;
 957 }
 958
 959 void device_handler_cancel_default(struct device_handler *handler)
 960 {
 961         struct boot_status status;
 962
 963         if (handler->timeout_waiter)
 964                 waiter_remove(handler->timeout_waiter);
 965
 966         handler->timeout_waiter = NULL;
 967         handler->autoboot_enabled = false;
 968
 969         /* we only send status if we had a default boot option queued */
 970         if (!handler->default_boot_option)
 971                 return;
 972
 973         pb_log("Cancelling default boot option\n");
 974
 975         if (handler->pending_boot && handler->pending_boot_is_default) {
 976                 boot_cancel(handler->pending_boot);
 977                 handler->pending_boot = NULL;
 978                 handler->pending_boot_is_default = false;
 979         }
 980
 981         handler->default_boot_option = NULL;
 982
 983         status.type = BOOT_STATUS_INFO;
 984         status.progress = -1;
 985         status.detail = NULL;
 986         status.message = _("Default boot cancelled");
 987
 988         discover_server_notify_boot_status(handler->server, &status);
 989 }
 990
 991 void device_handler_update_config(struct device_handler *handler,
 992                 struct config *config)
 993 {
 994         int rc;
 995
 996         rc = config_set(config);
 997         if (rc)
 998                 return;
 999
1000         discover_server_notify_config(handler->server, config);
1001         device_handler_update_lang(config->lang);
1002         device_handler_reinit(handler);
1003 }
1004
1005 static char *device_from_addr(void *ctx, struct pb_url *url)
1006 {
1007         char *ipaddr, *buf, *tok, *dev = NULL;
1008         const char *delim = " ";
1009         struct sockaddr_in *ip;
1010         struct sockaddr_in si;
1011         struct addrinfo *res;
1012         struct process *p;
1013         int rc;
1014
1015         /* Note: IPv4 only */
1016         rc = inet_pton(AF_INET, url->host, &(si.sin_addr));
1017         if (rc > 0) {
1018                 ipaddr = url->host;
1019         } else {
1020                 /* need to turn hostname into a valid IP */
1021                 rc = getaddrinfo(url->host, NULL, NULL, &res);
1022                 if (rc) {
1023                         pb_debug("%s: Invalid URL\n",__func__);
1024                         return NULL;
1025                 }
1026                 ipaddr = talloc_array(ctx,char,INET_ADDRSTRLEN);
1027                 ip = (struct sockaddr_in *) res->ai_addr;
1028                 inet_ntop(AF_INET, &(ip->sin_addr), ipaddr, INET_ADDRSTRLEN);
1029                 freeaddrinfo(res);
1030         }
1031
1032         const char *argv[] = {
1033                 pb_system_apps.ip,
1034                 "route", "show", "to", "match",
1035                 ipaddr,
1036                 NULL
1037         };
1038
1039         p = process_create(ctx);
1040
1041         p->path = pb_system_apps.ip;
1042         p->argv = argv;
1043         p->keep_stdout = true;
1044
1045         rc = process_run_sync(p);
1046
1047         if (rc || p->exit_status) {
1048                 /* ip has complained for some reason; most likely
1049                  * there is no route to the host - bail out */
1050                 pb_debug("%s: `ip` returns non-zero exit status\n", __func__);
1051                 pb_debug("ip buf: %s\n", p->stdout_buf);
1052                 process_release(p);
1053                 return NULL;
1054         }
1055
1056         buf = p->stdout_buf;
1057         /* If a route is found, ip-route output will be of the form
1058          * "... dev DEVNAME ... " */
1059         tok = strtok(buf, delim);
1060         while (tok) {
1061                 if (!strcmp(tok, "dev")) {
1062                         tok = strtok(NULL, delim);
1063                         dev = talloc_strdup(ctx, tok);
1064                         break;
1065                 }
1066                 tok = strtok(NULL, delim);
1067         }
1068
1069         process_release(p);
1070         if (dev)
1071                 pb_debug("%s: Found interface '%s'\n", __func__,dev);
1072         return dev;
1073 }
1074
1075 void device_handler_process_url(struct device_handler *handler,
1076                 const char *url, const char *mac, const char *ip)
1077 {
1078         struct discover_context *ctx;
1079         struct discover_device *dev;
1080         struct boot_status *status;
1081         struct pb_url *pb_url;
1082         struct event *event;
1083         struct param *param;
1084
1085         status = talloc(handler, struct boot_status);
1086
1087         status->type = BOOT_STATUS_ERROR;
1088         status->progress = 0;
1089         status->detail = talloc_asprintf(status,
1090                         _("Received config URL %s"), url);
1091
1092         if (!handler->network) {
1093                 status->message = talloc_asprintf(handler,
1094                                         _("No network configured"));
1095                 goto msg;
1096         }
1097
1098         event = talloc(handler, struct event);
1099         event->type = EVENT_TYPE_USER;
1100         event->action = EVENT_ACTION_URL;
1101
1102         if (url[strlen(url) - 1] == '/') {
1103                 event->params = talloc_array(event, struct param, 3);
1104                 param = &event->params[0];
1105                 param->name = talloc_strdup(event, "pxepathprefix");
1106                 param->value = talloc_strdup(event, url);
1107                 param = &event->params[1];
1108                 param->name = talloc_strdup(event, "mac");
1109                 param->value = talloc_strdup(event, mac);
1110                 param = &event->params[2];
1111                 param->name = talloc_strdup(event, "ip");
1112                 param->value = talloc_strdup(event, ip);
1113                 event->n_params = 3;
1114         } else {
1115                 event->params = talloc_array(event, struct param, 1);
1116                 param = &event->params[0];
1117                 param->name = talloc_strdup(event, "pxeconffile");
1118                 param->value = talloc_strdup(event, url);
1119                 event->n_params = 1;
1120         }
1121
1122         pb_url = pb_url_parse(event, event->params->value);
1123         if (!pb_url || (pb_url->scheme != pb_url_file && !pb_url->host)) {
1124                 status->message = talloc_asprintf(handler,
1125                                         _("Invalid config URL!"));
1126                 goto msg;
1127         }
1128
1129         if (pb_url->scheme == pb_url_file)
1130                 event->device = talloc_asprintf(event, "local");
1131         else
1132                 event->device = device_from_addr(event, pb_url);
1133
1134         if (!event->device) {
1135                 status->message = talloc_asprintf(status,
1136                                         _("Unable to route to host %s"),
1137                                         pb_url->host);
1138                 goto msg;
1139         }
1140
1141         dev = discover_device_create(handler, event->device);
1142         if (pb_url->scheme == pb_url_file)
1143                 dev->device->type = DEVICE_TYPE_ANY;
1144         ctx = device_handler_discover_context_create(handler, dev);
1145         talloc_steal(ctx, event);
1146         ctx->event = event;
1147
1148         iterate_parsers(ctx);
1149
1150         device_handler_discover_context_commit(handler, ctx);
1151
1152         talloc_unlink(handler, ctx);
1153
1154         status->type = BOOT_STATUS_INFO;
1155         status->message = talloc_asprintf(status, _("Config file %s parsed"),
1156                                         pb_url->file);
1157 msg:
1158         device_handler_boot_status(handler, status);
1159         talloc_free(status);
1160 }
1161
1162 #ifndef PETITBOOT_TEST
1163
1164 /**
1165  * context_commit - Commit a temporary discovery context to the handler,
1166  * and notify the clients about any new options / devices
1167  */
1168 void device_handler_discover_context_commit(struct device_handler *handler,
1169                 struct discover_context *ctx)
1170 {
1171         struct discover_device *dev = ctx->device;
1172         struct discover_boot_option *opt, *tmp;
1173
1174         if (!device_lookup_by_id(handler, dev->device->id))
1175                 device_handler_add_device(handler, dev);
1176
1177         /* move boot options from the context to the device */
1178         list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
1179                 list_remove(&opt->list);
1180
1181                 /* All boot options need at least a kernel image */
1182                 if (!opt->boot_image || !opt->boot_image->url) {
1183                         pb_log("boot option %s is missing boot image, ignoring\n",
1184                                 opt->option->id);
1185                         talloc_free(opt);
1186                         continue;
1187                 }
1188
1189                 if (boot_option_resolve(opt, handler)) {
1190                         pb_log("boot option %s is resolved, "
1191                                         "sending to clients\n",
1192                                         opt->option->id);
1193                         list_add_tail(&dev->boot_options, &opt->list);
1194                         talloc_steal(dev, opt);
1195                         boot_option_finalise(handler, opt);
1196                         notify_boot_option(handler, opt);
1197                 } else {
1198                         if (!opt->source->resolve_resource) {
1199                                 pb_log("parser %s gave us an unresolved "
1200                                         "resource (%s), but no way to "
1201                                         "resolve it\n",
1202                                         opt->source->name, opt->option->id);
1203                                 talloc_free(opt);
1204                         } else {
1205                                 pb_log("boot option %s is unresolved, "
1206                                                 "adding to queue\n",
1207                                                 opt->option->id);
1208                                 list_add(&handler->unresolved_boot_options,
1209                                                 &opt->list);
1210                                 talloc_steal(handler, opt);
1211                         }
1212                 }
1213         }
1214 }
1215
1216 static void device_handler_update_lang(const char *lang)
1217 {
1218         const char *cur_lang;
1219
1220         if (!lang)
1221                 return;
1222
1223         cur_lang = setlocale(LC_ALL, NULL);
1224         if (cur_lang && !strcmp(cur_lang, lang))
1225                 return;
1226
1227         setlocale(LC_ALL, lang);
1228 }
1229
1230 static int device_handler_init_sources(struct device_handler *handler)
1231 {
1232         /* init our device sources: udev, network and user events */
1233         handler->udev = udev_init(handler, handler->waitset);
1234         if (!handler->udev)
1235                 return -1;
1236
1237         handler->network = network_init(handler, handler->waitset,
1238                         handler->dry_run);
1239         if (!handler->network)
1240                 return -1;
1241
1242         handler->user_event = user_event_init(handler, handler->waitset);
1243         if (!handler->user_event)
1244                 return -1;
1245
1246         return 0;
1247 }
1248
1249 static void device_handler_reinit_sources(struct device_handler *handler)
1250 {
1251         /* if we haven't initialised sources previously (becuase we started in
1252          * safe mode), then init once here. */
1253         if (!(handler->udev || handler->network || handler->user_event)) {
1254                 device_handler_init_sources(handler);
1255                 return;
1256         }
1257
1258         udev_reinit(handler->udev);
1259
1260         network_shutdown(handler->network);
1261         handler->network = network_init(handler, handler->waitset,
1262                         handler->dry_run);
1263 }
1264
1265 static inline const char *get_device_path(struct discover_device *dev)
1266 {
1267         return dev->ramdisk ? dev->ramdisk->snapshot : dev->device_path;
1268 }
1269
1270 static char *check_subvols(struct discover_device *dev)
1271 {
1272         const char *fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1273         struct stat sb;
1274         char *path;
1275         int rc;
1276
1277         if (strncmp(fstype, "btrfs", strlen("btrfs")))
1278                 return dev->mount_path;
1279
1280         /* On btrfs a device's root may be under a subvolume path */
1281         path = join_paths(dev, dev->mount_path, "@");
1282         rc = stat(path, &sb);
1283         if (!rc && S_ISDIR(sb.st_mode)) {
1284                 pb_debug("Using '%s' for btrfs root path\n", path);
1285                 return path;
1286         }
1287
1288         talloc_free(path);
1289         return dev->mount_path;
1290 }
1291
1292 static bool check_existing_mount(struct discover_device *dev)
1293 {
1294         struct stat devstat, mntstat;
1295         const char *device_path;
1296         struct mntent *mnt;
1297         FILE *fp;
1298         int rc;
1299
1300         device_path = get_device_path(dev);
1301
1302         rc = stat(device_path, &devstat);
1303         if (rc) {
1304                 pb_debug("%s: stat failed: %s\n", __func__, strerror(errno));
1305                 return false;
1306         }
1307
1308         if (!S_ISBLK(devstat.st_mode)) {
1309                 pb_debug("%s: %s isn't a block device?\n", __func__,
1310                                 dev->device_path);
1311                 return false;
1312         }
1313
1314         fp = fopen("/proc/self/mounts", "r");
1315
1316         for (;;) {
1317                 mnt = getmntent(fp);
1318                 if (!mnt)
1319                         break;
1320
1321                 if (!mnt->mnt_fsname || mnt->mnt_fsname[0] != '/')
1322                         continue;
1323
1324                 rc = stat(mnt->mnt_fsname, &mntstat);
1325                 if (rc)
1326                         continue;
1327
1328                 if (!S_ISBLK(mntstat.st_mode))
1329                         continue;
1330
1331                 if (mntstat.st_rdev == devstat.st_rdev) {
1332                         dev->mount_path = talloc_strdup(dev, mnt->mnt_dir);
1333                         dev->root_path = check_subvols(dev);
1334                         dev->mounted_rw = !!hasmntopt(mnt, "rw");
1335                         dev->mounted = true;
1336                         dev->unmount = false;
1337
1338                         pb_debug("%s: %s is already mounted (r%c) at %s\n",
1339                                         __func__, dev->device_path,
1340                                         dev->mounted_rw ? 'w' : 'o',
1341                                         mnt->mnt_dir);
1342                         break;
1343                 }
1344         }
1345
1346         fclose(fp);
1347
1348         return mnt != NULL;
1349 }
1350
1351 /*
1352  * Attempt to mount a filesystem safely, while handling certain filesytem-
1353  * specific options
1354  */
1355 static int try_mount(const char *device_path, const char *mount_path,
1356                              const char *fstype, unsigned long flags,
1357                              bool have_snapshot)
1358 {
1359         const char *fs, *safe_opts;
1360         int rc;
1361
1362         /* Mount ext3 as ext4 instead so 'norecovery' can be used */
1363         if (strncmp(fstype, "ext3", strlen("ext3")) == 0) {
1364                 pb_debug("Mounting ext3 filesystem as ext4\n");
1365                 fs = "ext4";
1366         } else
1367                 fs = fstype;
1368
1369         if (strncmp(fs, "xfs", strlen("xfs")) == 0 ||
1370             strncmp(fs, "ext4", strlen("ext4")) == 0)
1371                 safe_opts = "norecovery";
1372         else
1373                 safe_opts = NULL;
1374
1375         errno = 0;
1376         /* If no snapshot is available don't attempt recovery */
1377         if (!have_snapshot)
1378                 return mount(device_path, mount_path, fs, flags, safe_opts);
1379
1380         rc = mount(device_path, mount_path, fs, flags, NULL);
1381
1382         if (!rc)
1383                 return rc;
1384
1385         /* Mounting failed; some filesystems will fail to mount if a recovery
1386          * journal exists (eg. cross-endian XFS), so try again with norecovery
1387          * where that option is available.
1388          * If mounting read-write just return the error as norecovery is not a
1389          * valid option */
1390         if ((flags & MS_RDONLY) != MS_RDONLY || !safe_opts)
1391                 return rc;
1392
1393         errno = 0;
1394         return mount(device_path, mount_path, fs, flags, safe_opts);
1395 }
1396
1397 static int mount_device(struct discover_device *dev)
1398 {
1399         const char *fstype, *device_path;
1400         int rc;
1401
1402         if (!dev->device_path)
1403                 return -1;
1404
1405         if (dev->mounted)
1406                 return 0;
1407
1408         if (check_existing_mount(dev))
1409                 return 0;
1410
1411         fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1412         if (!fstype)
1413                 return 0;
1414
1415         dev->mount_path = join_paths(dev, mount_base(),
1416                                         dev->device_path);
1417
1418         if (pb_mkdir_recursive(dev->mount_path)) {
1419                 pb_log("couldn't create mount directory %s: %s\n",
1420                                 dev->mount_path, strerror(errno));
1421                 goto err_free;
1422         }
1423
1424         device_path = get_device_path(dev);
1425
1426         pb_log("mounting device %s read-only\n", dev->device_path);
1427         rc = try_mount(device_path, dev->mount_path, fstype,
1428                        MS_RDONLY | MS_SILENT, dev->ramdisk);
1429
1430         if (!rc) {
1431                 dev->mounted = true;
1432                 dev->mounted_rw = false;
1433                 dev->unmount = true;
1434                 dev->root_path = check_subvols(dev);
1435                 return 0;
1436         }
1437
1438         pb_log("couldn't mount device %s: mount failed: %s\n",
1439                         device_path, strerror(errno));
1440
1441         /* If mount fails clean up any snapshot */
1442         devmapper_destroy_snapshot(dev);
1443
1444         pb_rmdir_recursive(mount_base(), dev->mount_path);
1445 err_free:
1446         talloc_free(dev->mount_path);
1447         dev->mount_path = NULL;
1448         return -1;
1449 }
1450
1451 static int umount_device(struct discover_device *dev)
1452 {
1453         const char *device_path;
1454         int rc;
1455
1456         if (!dev->mounted || !dev->unmount)
1457                 return 0;
1458
1459         device_path = get_device_path(dev);
1460
1461         pb_log("unmounting device %s\n", device_path);
1462         rc = umount(dev->mount_path);
1463         if (rc)
1464                 return -1;
1465
1466         dev->mounted = false;
1467         devmapper_destroy_snapshot(dev);
1468
1469         pb_rmdir_recursive(mount_base(), dev->mount_path);
1470
1471         talloc_free(dev->mount_path);
1472         dev->mount_path = NULL;
1473         dev->root_path = NULL;
1474
1475         return 0;
1476 }
1477
1478 int device_request_write(struct discover_device *dev, bool *release)
1479 {
1480         const char *fstype, *device_path;
1481         const struct config *config;
1482         int rc;
1483
1484         *release = false;
1485
1486         config = config_get();
1487         if (!config->allow_writes)
1488                 return -1;
1489
1490         if (!dev->mounted)
1491                 return -1;
1492
1493         if (dev->mounted_rw)
1494                 return 0;
1495
1496         fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1497
1498         device_path = get_device_path(dev);
1499
1500         pb_log("remounting device %s read-write\n", device_path);
1501
1502         rc = umount(dev->mount_path);
1503         if (rc) {
1504                 pb_log("Failed to unmount %s: %s\n",
1505                        dev->mount_path, strerror(errno));
1506                 return -1;
1507         }
1508
1509         rc = try_mount(device_path, dev->mount_path, fstype,
1510                        MS_SILENT, dev->ramdisk);
1511         if (rc)
1512                 goto mount_ro;
1513
1514         dev->mounted_rw = true;
1515         *release = true;
1516         return 0;
1517
1518 mount_ro:
1519         pb_log("Unable to remount device %s read-write: %s\n",
1520                device_path, strerror(errno));
1521         rc = try_mount(device_path, dev->mount_path, fstype,
1522                        MS_RDONLY | MS_SILENT, dev->ramdisk);
1523         if (rc)
1524                 pb_log("Unable to recover mount for %s: %s\n",
1525                        device_path, strerror(errno));
1526         return -1;
1527 }
1528
1529 void device_release_write(struct discover_device *dev, bool release)
1530 {
1531         const char *fstype, *device_path;
1532
1533         if (!release)
1534                 return;
1535
1536         device_path = get_device_path(dev);
1537
1538         fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1539
1540         pb_log("remounting device %s read-only\n", device_path);
1541
1542         if (umount(dev->mount_path)) {
1543                 pb_log("Failed to unmount %s\n", dev->mount_path);
1544                 return;
1545         }
1546         dev->mounted_rw = dev->mounted = false;
1547
1548         if (dev->ramdisk) {
1549                 devmapper_merge_snapshot(dev);
1550                 /* device_path becomes stale after merge */
1551                 device_path = get_device_path(dev);
1552         }
1553
1554         if (try_mount(device_path, dev->mount_path, fstype,
1555                        MS_RDONLY | MS_SILENT, dev->ramdisk))
1556                 pb_log("Failed to remount %s read-only: %s\n",
1557                        device_path, strerror(errno));
1558         else
1559                 dev->mounted = true;
1560 }
1561
1562 void device_sync_snapshots(struct device_handler *handler, const char *device)
1563 {
1564         struct discover_device *dev = NULL;
1565         unsigned int i;
1566
1567         if (device) {
1568                 /* Find matching device and sync */
1569                 dev = device_lookup_by_name(handler, device);
1570                 if (!dev) {
1571                         pb_log("%s: device name '%s' unrecognised\n",
1572                                 __func__, device);
1573                         return;
1574                 }
1575                 if (dev->ramdisk)
1576                         device_release_write(dev, true);
1577                 else
1578                         pb_log("%s has no snapshot to merge, skipping\n",
1579                                 dev->device->id);
1580                 return;
1581         }
1582
1583         /* Otherwise sync all relevant devices */
1584         for (i = 0; i < handler->n_devices; i++) {
1585                 dev = handler->devices[i];
1586                 if (dev->device->type != DEVICE_TYPE_DISK &&
1587                         dev->device->type != DEVICE_TYPE_USB)
1588                         continue;
1589                 if (dev->ramdisk)
1590                         device_release_write(dev, true);
1591                 else
1592                         pb_log("%s has no snapshot to merge, skipping\n",
1593                                 dev->device->id);
1594         }
1595 }
1596
1597 #else
1598
1599 void device_handler_discover_context_commit(
1600                 struct device_handler *handler __attribute__((unused)),
1601                 struct discover_context *ctx __attribute__((unused)))
1602 {
1603         pb_log("%s stubbed out for test cases\n", __func__);
1604 }
1605
1606 static void device_handler_update_lang(const char *lang __attribute__((unused)))
1607 {
1608 }
1609
1610 static int device_handler_init_sources(
1611                 struct device_handler *handler __attribute__((unused)))
1612 {
1613         return 0;
1614 }
1615
1616 static void device_handler_reinit_sources(
1617                 struct device_handler *handler __attribute__((unused)))
1618 {
1619 }
1620
1621 static int umount_device(struct discover_device *dev __attribute__((unused)))
1622 {
1623         return 0;
1624 }
1625
1626 static int __attribute__((unused)) mount_device(
1627                 struct discover_device *dev __attribute__((unused)))
1628 {
1629         return 0;
1630 }
1631
1632 int device_request_write(struct discover_device *dev __attribute__((unused)),
1633                 bool *release)
1634 {
1635         *release = true;
1636         return 0;
1637 }
1638
1639 void device_release_write(struct discover_device *dev __attribute__((unused)),
1640         bool release __attribute__((unused)))
1641 {
1642 }
1643
1644 void device_sync_snapshots(
1645                 struct device_handler *handler __attribute__((unused)),
1646                 const char *device __attribute__((unused)))
1647 {
1648 }
1649
1650 #endif