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 *uuid, const char *id)
 225 {
 226         struct discover_device *dev;
 227
 228         if (uuid)
 229                 dev = device_lookup_by_uuid(handler, uuid);
 230         else
 231                 dev = device_lookup_by_id(handler, id);
 232
 233         if (dev)
 234                 return dev;
 235
 236         dev = talloc_zero(handler, struct discover_device);
 237         dev->device = talloc_zero(dev, struct device);
 238         dev->device->id = talloc_strdup(dev->device, id);
 239         dev->uuid = talloc_strdup(dev, uuid);
 240         list_init(&dev->params);
 241         list_init(&dev->boot_options);
 242
 243         talloc_set_destructor(dev, destroy_device);
 244
 245         return dev;
 246 }
 247
 248 struct discover_device_param {
 249         char                    *name;
 250         char                    *value;
 251         struct list_item        list;
 252 };
 253
 254 void discover_device_set_param(struct discover_device *device,
 255                 const char *name, const char *value)
 256 {
 257         struct discover_device_param *param;
 258         bool found = false;
 259
 260         list_for_each_entry(&device->params, param, list) {
 261                 if (!strcmp(param->name, name)) {
 262                         found = true;
 263                         break;
 264                 }
 265         }
 266
 267         if (!found) {
 268                 if (!value)
 269                         return;
 270                 param = talloc(device, struct discover_device_param);
 271                 param->name = talloc_strdup(param, name);
 272                 list_add(&device->params, &param->list);
 273         } else {
 274                 if (!value) {
 275                         list_remove(&param->list);
 276                         talloc_free(param);
 277                         return;
 278                 }
 279                 talloc_free(param->value);
 280         }
 281
 282         param->value = talloc_strdup(param, value);
 283 }
 284
 285 const char *discover_device_get_param(struct discover_device *device,
 286                 const char *name)
 287 {
 288         struct discover_device_param *param;
 289
 290         list_for_each_entry(&device->params, param, list) {
 291                 if (!strcmp(param->name, name))
 292                         return param->value;
 293         }
 294         return NULL;
 295 }
 296
 297 struct device_handler *device_handler_init(struct discover_server *server,
 298                 struct waitset *waitset, int dry_run)
 299 {
 300         struct device_handler *handler;
 301         int rc;
 302
 303         handler = talloc_zero(NULL, struct device_handler);
 304         handler->server = server;
 305         handler->waitset = waitset;
 306         handler->dry_run = dry_run;
 307         handler->autoboot_enabled = config_get()->autoboot_enabled;
 308
 309         list_init(&handler->unresolved_boot_options);
 310
 311         /* set up our mount point base */
 312         pb_mkdir_recursive(mount_base());
 313
 314         parser_init();
 315
 316         if (config_get()->safe_mode)
 317                 return handler;
 318
 319         rc = device_handler_init_sources(handler);
 320         if (rc) {
 321                 talloc_free(handler);
 322                 return NULL;
 323         }
 324
 325         return handler;
 326 }
 327
 328 void device_handler_reinit(struct device_handler *handler)
 329 {
 330         struct discover_boot_option *opt, *tmp;
 331         struct ramdisk_device *ramdisk;
 332         unsigned int i;
 333
 334         device_handler_cancel_default(handler);
 335
 336         /* free unresolved boot options */
 337         list_for_each_entry_safe(&handler->unresolved_boot_options,
 338                         opt, tmp, list)
 339                 talloc_free(opt);
 340         list_init(&handler->unresolved_boot_options);
 341
 342         /* drop all devices */
 343         for (i = 0; i < handler->n_devices; i++) {
 344                 discover_server_notify_device_remove(handler->server,
 345                                 handler->devices[i]->device);
 346                 ramdisk = handler->devices[i]->ramdisk;
 347                 talloc_free(handler->devices[i]);
 348                 talloc_free(ramdisk);
 349         }
 350
 351         talloc_free(handler->devices);
 352         handler->devices = NULL;
 353         handler->n_devices = 0;
 354         talloc_free(handler->ramdisks);
 355         handler->ramdisks = NULL;
 356         handler->n_ramdisks = 0;
 357
 358         device_handler_reinit_sources(handler);
 359 }
 360
 361 void device_handler_remove(struct device_handler *handler,
 362                 struct discover_device *device)
 363 {
 364         struct discover_boot_option *opt, *tmp;
 365         unsigned int i;
 366
 367         list_for_each_entry_safe(&device->boot_options, opt, tmp, list) {
 368                 if (opt == handler->default_boot_option) {
 369                         pb_log("Default option %s cancelled since device removed",
 370                                         opt->option->name);
 371                         device_handler_cancel_default(handler);
 372                         break;
 373                 }
 374         }
 375
 376         for (i = 0; i < handler->n_devices; i++)
 377                 if (handler->devices[i] == device)
 378                         break;
 379
 380         if (i == handler->n_devices) {
 381                 talloc_free(device);
 382                 return;
 383         }
 384
 385         /* Free any unresolved options, as they're currently allocated
 386          * against the handler */
 387         list_for_each_entry_safe(&handler->unresolved_boot_options,
 388                         opt, tmp, list) {
 389                 if (opt->device != device)
 390                         continue;
 391                 list_remove(&opt->list);
 392                 talloc_free(opt);
 393         }
 394
 395         /* if this is a network device, we have to unregister it from the
 396          * network code */
 397         if (device->device->type == DEVICE_TYPE_NETWORK)
 398                 network_unregister_device(handler->network, device);
 399
 400         handler->n_devices--;
 401         memmove(&handler->devices[i], &handler->devices[i + 1],
 402                 (handler->n_devices - i) * sizeof(handler->devices[0]));
 403         handler->devices = talloc_realloc(handler, handler->devices,
 404                 struct discover_device *, handler->n_devices);
 405
 406         if (device->notified)
 407                 discover_server_notify_device_remove(handler->server,
 408                                                         device->device);
 409
 410         talloc_free(device);
 411 }
 412
 413 void device_handler_status(struct device_handler *handler,
 414                 struct status *status)
 415 {
 416         discover_server_notify_boot_status(handler->server, status);
 417 }
 418
 419 static void device_handler_boot_status_cb(void *arg, struct status *status)
 420 {
 421         device_handler_status(arg, status);
 422 }
 423
 424 static void countdown_status(struct device_handler *handler,
 425                 struct discover_boot_option *opt, unsigned int sec)
 426 {
 427         struct status status;
 428
 429         status.type = STATUS_INFO;
 430         status.message = talloc_asprintf(handler,
 431                         _("Booting in %d sec: %s"), sec, opt->option->name);
 432
 433         device_handler_status(handler, &status);
 434
 435         talloc_free(status.message);
 436 }
 437
 438 static int default_timeout(void *arg)
 439 {
 440         struct device_handler *handler = arg;
 441         struct discover_boot_option *opt;
 442
 443         if (!handler->default_boot_option)
 444                 return 0;
 445
 446         if (handler->pending_boot)
 447                 return 0;
 448
 449         opt = handler->default_boot_option;
 450
 451         if (handler->sec_to_boot) {
 452                 countdown_status(handler, opt, handler->sec_to_boot);
 453                 handler->sec_to_boot--;
 454                 handler->timeout_waiter = waiter_register_timeout(
 455                                                 handler->waitset, 1000,
 456                                                 default_timeout, handler);
 457                 return 0;
 458         }
 459
 460         handler->timeout_waiter = NULL;
 461
 462         pb_log("Timeout expired, booting default option %s\n", opt->option->id);
 463
 464         platform_pre_boot();
 465
 466         handler->pending_boot = boot(handler, handler->default_boot_option,
 467                         NULL, handler->dry_run, device_handler_boot_status_cb,
 468                         handler);
 469         handler->pending_boot_is_default = true;
 470         return 0;
 471 }
 472
 473 struct {
 474         enum ipmi_bootdev       ipmi_type;
 475         enum device_type        device_type;
 476 } device_type_map[] = {
 477         { IPMI_BOOTDEV_NETWORK, DEVICE_TYPE_NETWORK },
 478         { IPMI_BOOTDEV_DISK, DEVICE_TYPE_DISK },
 479         { IPMI_BOOTDEV_DISK, DEVICE_TYPE_USB },
 480         { IPMI_BOOTDEV_CDROM, DEVICE_TYPE_OPTICAL },
 481 };
 482
 483 static bool ipmi_device_type_matches(enum ipmi_bootdev ipmi_type,
 484                 enum device_type device_type)
 485 {
 486         unsigned int i;
 487
 488         for (i = 0; i < ARRAY_SIZE(device_type_map); i++) {
 489                 if (device_type_map[i].device_type == device_type)
 490                         return device_type_map[i].ipmi_type == ipmi_type;
 491         }
 492
 493         return false;
 494 }
 495
 496 static int autoboot_option_priority(const struct config *config,
 497                                 struct discover_boot_option *opt)
 498 {
 499         enum device_type type = opt->device->device->type;
 500         const char *uuid = opt->device->uuid;
 501         struct autoboot_option *auto_opt;
 502         unsigned int i;
 503
 504         for (i = 0; i < config->n_autoboot_opts; i++) {
 505                 auto_opt = &config->autoboot_opts[i];
 506                 if (auto_opt->boot_type == BOOT_DEVICE_UUID)
 507                         if (!strcmp(auto_opt->uuid, uuid))
 508                                 return DEFAULT_PRIORITY_LOCAL_FIRST + i;
 509
 510                 if (auto_opt->boot_type == BOOT_DEVICE_TYPE)
 511                         if (auto_opt->type == type ||
 512                             auto_opt->type == DEVICE_TYPE_ANY)
 513                                 return DEFAULT_PRIORITY_LOCAL_FIRST + i;
 514         }
 515
 516         return -1;
 517 }
 518
 519 /*
 520  * We have different priorities to resolve conflicts between boot options that
 521  * report to be the default for their device. This function assigns a priority
 522  * for these options.
 523  */
 524 static enum default_priority default_option_priority(
 525                 struct discover_boot_option *opt)
 526 {
 527         const struct config *config;
 528
 529         config = config_get();
 530
 531         /* We give highest priority to IPMI-configured boot options. If
 532          * we have an IPMI bootdev configuration set, then we don't allow
 533          * any other defaults */
 534         if (config->ipmi_bootdev) {
 535                 bool ipmi_match = ipmi_device_type_matches(config->ipmi_bootdev,
 536                                 opt->device->device->type);
 537                 if (ipmi_match)
 538                         return DEFAULT_PRIORITY_REMOTE;
 539
 540                 pb_debug("handler: disabled default priority due to "
 541                                 "non-matching IPMI type %x\n",
 542                                 config->ipmi_bootdev);
 543                 return DEFAULT_PRIORITY_DISABLED;
 544         }
 545
 546         /* Next, try to match the option against the user-defined autoboot
 547          * options, either by device UUID or type. */
 548         if (config->n_autoboot_opts) {
 549                 int boot_match = autoboot_option_priority(config, opt);
 550                 if (boot_match > 0)
 551                         return boot_match;
 552         }
 553
 554         /* If the option didn't match any entry in the array, it is disabled */
 555         pb_debug("handler: disabled default priority due to "
 556                         "non-matching UUID or type\n");
 557         return DEFAULT_PRIORITY_DISABLED;
 558 }
 559
 560 static void set_default(struct device_handler *handler,
 561                 struct discover_boot_option *opt)
 562 {
 563         enum default_priority cur_prio, new_prio;
 564
 565         if (!handler->autoboot_enabled)
 566                 return;
 567
 568         pb_debug("handler: new default option: %s\n", opt->option->id);
 569
 570         new_prio = default_option_priority(opt);
 571
 572         /* Anything outside our range prevents a default boot */
 573         if (new_prio >= DEFAULT_PRIORITY_DISABLED)
 574                 return;
 575
 576         pb_debug("handler: calculated priority %d\n", new_prio);
 577
 578         /* Resolve any conflicts: if we have a new default option, it only
 579          * replaces the current if it has a higher priority. */
 580         if (handler->default_boot_option) {
 581
 582                 cur_prio = handler->default_boot_option_priority;
 583
 584                 if (new_prio < cur_prio) {
 585                         pb_log("handler: new prio %d beats "
 586                                         "old prio %d for %s\n",
 587                                         new_prio, cur_prio,
 588                                         handler->default_boot_option
 589                                                 ->option->id);
 590                         handler->default_boot_option = opt;
 591                         handler->default_boot_option_priority = new_prio;
 592                         /* extend the timeout a little, so the user sees some
 593                          * indication of the change */
 594                         handler->sec_to_boot += 2;
 595                 }
 596
 597                 return;
 598         }
 599
 600         handler->sec_to_boot = config_get()->autoboot_timeout_sec;
 601         handler->default_boot_option = opt;
 602         handler->default_boot_option_priority = new_prio;
 603
 604         pb_log("handler: boot option %s set as default, timeout %u sec.\n",
 605                opt->option->id, handler->sec_to_boot);
 606
 607         default_timeout(handler);
 608 }
 609
 610 static bool resource_is_resolved(struct resource *res)
 611 {
 612         return !res || res->resolved;
 613 }
 614
 615 /* We only use this in an assert, which will disappear if we're compiling
 616  * with NDEBUG, so we need the 'used' attribute for these builds */
 617 static bool __attribute__((used)) boot_option_is_resolved(
 618                 struct discover_boot_option *opt)
 619 {
 620         return resource_is_resolved(opt->boot_image) &&
 621                 resource_is_resolved(opt->initrd) &&
 622                 resource_is_resolved(opt->dtb) &&
 623                 resource_is_resolved(opt->args_sig_file) &&
 624                 resource_is_resolved(opt->icon);
 625 }
 626
 627 static bool resource_resolve(struct resource *res, const char *name,
 628                 struct discover_boot_option *opt,
 629                 struct device_handler *handler)
 630 {
 631         struct parser *parser = opt->source;
 632
 633         if (resource_is_resolved(res))
 634                 return true;
 635
 636         pb_debug("Attempting to resolve resource %s->%s with parser %s\n",
 637                         opt->option->id, name, parser->name);
 638         parser->resolve_resource(handler, res);
 639
 640         return res->resolved;
 641 }
 642
 643 static bool boot_option_resolve(struct discover_boot_option *opt,
 644                 struct device_handler *handler)
 645 {
 646         return resource_resolve(opt->boot_image, "boot_image", opt, handler) &&
 647                 resource_resolve(opt->initrd, "initrd", opt, handler) &&
 648                 resource_resolve(opt->dtb, "dtb", opt, handler) &&
 649                 resource_resolve(opt->args_sig_file, "args_sig_file", opt,
 650                         handler) &&
 651                 resource_resolve(opt->icon, "icon", opt, handler);
 652 }
 653
 654 static void boot_option_finalise(struct device_handler *handler,
 655                 struct discover_boot_option *opt)
 656 {
 657         assert(boot_option_is_resolved(opt));
 658
 659         /* check that the parsers haven't set any of the final data */
 660         assert(!opt->option->boot_image_file);
 661         assert(!opt->option->initrd_file);
 662         assert(!opt->option->dtb_file);
 663         assert(!opt->option->icon_file);
 664         assert(!opt->option->device_id);
 665         assert(!opt->option->args_sig_file);
 666
 667         if (opt->boot_image)
 668                 opt->option->boot_image_file = opt->boot_image->url->full;
 669         if (opt->initrd)
 670                 opt->option->initrd_file = opt->initrd->url->full;
 671         if (opt->dtb)
 672                 opt->option->dtb_file = opt->dtb->url->full;
 673         if (opt->icon)
 674                 opt->option->icon_file = opt->icon->url->full;
 675         if (opt->args_sig_file)
 676                 opt->option->args_sig_file = opt->args_sig_file->url->full;
 677
 678         opt->option->device_id = opt->device->device->id;
 679
 680         if (opt->option->is_default)
 681                 set_default(handler, opt);
 682 }
 683
 684 static void notify_boot_option(struct device_handler *handler,
 685                 struct discover_boot_option *opt)
 686 {
 687         struct discover_device *dev = opt->device;
 688
 689         if (!dev->notified)
 690                 discover_server_notify_device_add(handler->server,
 691                                                   opt->device->device);
 692         dev->notified = true;
 693         discover_server_notify_boot_option_add(handler->server, opt->option);
 694 }
 695
 696 static void process_boot_option_queue(struct device_handler *handler)
 697 {
 698         struct discover_boot_option *opt, *tmp;
 699
 700         list_for_each_entry_safe(&handler->unresolved_boot_options,
 701                         opt, tmp, list) {
 702
 703                 pb_debug("queue: attempting resolution for %s\n",
 704                                 opt->option->id);
 705
 706                 if (!boot_option_resolve(opt, handler))
 707                         continue;
 708
 709                 pb_debug("\tresolved!\n");
 710
 711                 list_remove(&opt->list);
 712                 list_add_tail(&opt->device->boot_options, &opt->list);
 713                 talloc_steal(opt->device, opt);
 714                 boot_option_finalise(handler, opt);
 715                 notify_boot_option(handler, opt);
 716         }
 717 }
 718
 719 struct discover_context *device_handler_discover_context_create(
 720                 struct device_handler *handler,
 721                 struct discover_device *device)
 722 {
 723         struct discover_context *ctx;
 724
 725         ctx = talloc_zero(handler, struct discover_context);
 726         ctx->device = device;
 727         ctx->network = handler->network;
 728         list_init(&ctx->boot_options);
 729
 730         return ctx;
 731 }
 732
 733 void device_handler_add_device(struct device_handler *handler,
 734                 struct discover_device *device)
 735 {
 736         handler->n_devices++;
 737         handler->devices = talloc_realloc(handler, handler->devices,
 738                                 struct discover_device *, handler->n_devices);
 739         handler->devices[handler->n_devices - 1] = device;
 740
 741         if (device->device->type == DEVICE_TYPE_NETWORK)
 742                 network_register_device(handler->network, device);
 743 }
 744
 745 void device_handler_add_ramdisk(struct device_handler *handler,
 746                 const char *path)
 747 {
 748         struct ramdisk_device *dev;
 749         unsigned int i;
 750
 751         if (!path)
 752                 return;
 753
 754         for (i = 0; i < handler->n_ramdisks; i++)
 755                 if (!strcmp(handler->ramdisks[i]->path, path))
 756                         return;
 757
 758         dev = talloc_zero(handler, struct ramdisk_device);
 759         if (!dev) {
 760                 pb_log("Failed to allocate memory to track %s\n", path);
 761                 return;
 762         }
 763
 764         dev->path = talloc_strdup(handler, path);
 765
 766         handler->ramdisks = talloc_realloc(handler, handler->ramdisks,
 767                                 struct ramdisk_device *,
 768                                 handler->n_ramdisks + 1);
 769         if (!handler->ramdisks) {
 770                 pb_log("Failed to reallocate memory"
 771                        "- ramdisk tracking inconsistent!\n");
 772                 return;
 773         }
 774
 775         handler->ramdisks[i] = dev;
 776         i = handler->n_ramdisks++;
 777 }
 778
 779 struct ramdisk_device *device_handler_get_ramdisk(
 780                 struct device_handler *handler)
 781 {
 782         unsigned int i;
 783         char *name;
 784         dev_t id;
 785
 786         /* Check if free ramdisk exists */
 787         for (i = 0; i < handler->n_ramdisks; i++)
 788                 if (!handler->ramdisks[i]->snapshot &&
 789                     !handler->ramdisks[i]->origin &&
 790                     !handler->ramdisks[i]->base)
 791                         return handler->ramdisks[i];
 792
 793         /* Otherwise create a new one */
 794         name = talloc_asprintf(handler, "/dev/ram%d",
 795                         handler->n_ramdisks);
 796         if (!name) {
 797                 pb_debug("Failed to allocate memory to name /dev/ram%d",
 798                         handler->n_ramdisks);
 799                 return NULL;
 800         }
 801
 802         id = makedev(1, handler->n_ramdisks);
 803         if (mknod(name, S_IFBLK, id)) {
 804                 if (errno == EEXIST) {
 805                         /* We haven't yet received updates for existing
 806                          * ramdisks - add and use this one */
 807                         pb_debug("Using untracked ramdisk %s\n", name);
 808                 } else {
 809                         pb_log("Failed to create new ramdisk %s: %s\n",
 810                                name, strerror(errno));
 811                         return NULL;
 812                 }
 813         }
 814         device_handler_add_ramdisk(handler, name);
 815         talloc_free(name);
 816
 817         return handler->ramdisks[i];
 818 }
 819
 820 void device_handler_release_ramdisk(struct discover_device *device)
 821 {
 822         struct ramdisk_device *ramdisk = device->ramdisk;
 823
 824         talloc_free(ramdisk->snapshot);
 825         talloc_free(ramdisk->origin);
 826         talloc_free(ramdisk->base);
 827
 828         ramdisk->snapshot = ramdisk->origin = ramdisk->base = NULL;
 829         ramdisk->sectors = 0;
 830
 831         device->ramdisk = NULL;
 832 }
 833
 834 /* Start discovery on a hotplugged device. The device will be in our devices
 835  * array, but has only just been initialised by the hotplug source.
 836  */
 837 int device_handler_discover(struct device_handler *handler,
 838                 struct discover_device *dev)
 839 {
 840         struct discover_context *ctx;
 841         struct status *status;
 842         int rc;
 843
 844         status = talloc_zero(handler, struct status);
 845         status->type = STATUS_INFO;
 846         /*
 847          * TRANSLATORS: this string will be passed the type and identifier
 848          * of the device. For example, the first parameter could be "Disk",
 849          * (which will be translated accordingly) and the second a Linux device
 850          * identifier like 'sda1' (which will not be translated)
 851          */
 852         status->message = talloc_asprintf(status, _("Processing %s device %s"),
 853                                 device_type_display_name(dev->device->type),
 854                                 dev->device->id);
 855         device_handler_status(handler, status);
 856
 857         process_boot_option_queue(handler);
 858
 859         /* create our context */
 860         ctx = device_handler_discover_context_create(handler, dev);
 861
 862         rc = mount_device(dev);
 863         if (rc)
 864                 goto out;
 865
 866         /* add this device to our system info */
 867         system_info_register_blockdev(dev->device->id, dev->uuid,
 868                         dev->mount_path);
 869
 870         /* run the parsers. This will populate the ctx's boot_option list. */
 871         iterate_parsers(ctx);
 872
 873         /* add discovered stuff to the handler */
 874         device_handler_discover_context_commit(handler, ctx);
 875
 876 out:
 877         /*
 878          * TRANSLATORS: the format specifier in this string is a Linux
 879          * device identifier, like 'sda1'
 880          */
 881         status->message = talloc_asprintf(status,_("Processing %s complete"),
 882                                 dev->device->id);
 883         device_handler_status(handler, status);
 884
 885         talloc_free(status);
 886         talloc_unlink(handler, ctx);
 887
 888         return 0;
 889 }
 890
 891 /* Incoming dhcp event */
 892 int device_handler_dhcp(struct device_handler *handler,
 893                 struct discover_device *dev, struct event *event)
 894 {
 895         struct discover_context *ctx;
 896         struct status *status;
 897
 898         status = talloc_zero(handler, struct status);
 899         status->type = STATUS_INFO;
 900         /*
 901          * TRANSLATORS: this format specifier will be the name of a network
 902          * device, like 'eth0'.
 903          */
 904         status->message = talloc_asprintf(status, _("Processing dhcp event on %s"),
 905                                 dev->device->id);
 906         device_handler_status(handler, status);
 907
 908         /* create our context */
 909         ctx = device_handler_discover_context_create(handler, dev);
 910         talloc_steal(ctx, event);
 911         ctx->event = event;
 912
 913         iterate_parsers(ctx);
 914
 915         device_handler_discover_context_commit(handler, ctx);
 916
 917         /*
 918          * TRANSLATORS: this format specifier will be the name of a network
 919          * device, like 'eth0'.
 920          */
 921         status->message = talloc_asprintf(status,_("Processing %s complete"),
 922                                 dev->device->id);
 923         device_handler_status(handler, status);
 924
 925         talloc_free(status);
 926         talloc_unlink(handler, ctx);
 927
 928         return 0;
 929 }
 930
 931 static struct discover_boot_option *find_boot_option_by_id(
 932                 struct device_handler *handler, const char *id)
 933 {
 934         unsigned int i;
 935
 936         for (i = 0; i < handler->n_devices; i++) {
 937                 struct discover_device *dev = handler->devices[i];
 938                 struct discover_boot_option *opt;
 939
 940                 list_for_each_entry(&dev->boot_options, opt, list)
 941                         if (!strcmp(opt->option->id, id))
 942                                 return opt;
 943         }
 944
 945         return NULL;
 946 }
 947
 948 void device_handler_boot(struct device_handler *handler,
 949                 struct boot_command *cmd)
 950 {
 951         struct discover_boot_option *opt = NULL;
 952
 953         if (cmd->option_id && strlen(cmd->option_id))
 954                 opt = find_boot_option_by_id(handler, cmd->option_id);
 955
 956         if (handler->pending_boot)
 957                 boot_cancel(handler->pending_boot);
 958
 959         platform_pre_boot();
 960
 961         handler->pending_boot = boot(handler, opt, cmd, handler->dry_run,
 962                         device_handler_boot_status_cb, handler);
 963         handler->pending_boot_is_default = false;
 964 }
 965
 966 void device_handler_cancel_default(struct device_handler *handler)
 967 {
 968         struct status status;
 969
 970         if (handler->timeout_waiter)
 971                 waiter_remove(handler->timeout_waiter);
 972
 973         handler->timeout_waiter = NULL;
 974         handler->autoboot_enabled = false;
 975
 976         /* we only send status if we had a default boot option queued */
 977         if (!handler->default_boot_option)
 978                 return;
 979
 980         pb_log("Cancelling default boot option\n");
 981
 982         if (handler->pending_boot && handler->pending_boot_is_default) {
 983                 boot_cancel(handler->pending_boot);
 984                 handler->pending_boot = NULL;
 985                 handler->pending_boot_is_default = false;
 986         }
 987
 988         handler->default_boot_option = NULL;
 989
 990         status.type = STATUS_INFO;
 991         status.message = _("Default boot cancelled");
 992
 993         device_handler_status(handler, &status);
 994 }
 995
 996 void device_handler_update_config(struct device_handler *handler,
 997                 struct config *config)
 998 {
 999         int rc;
1000
1001         rc = config_set(config);
1002         if (rc)
1003                 return;
1004
1005         discover_server_notify_config(handler->server, config);
1006         device_handler_update_lang(config->lang);
1007         device_handler_reinit(handler);
1008 }
1009
1010 static char *device_from_addr(void *ctx, struct pb_url *url)
1011 {
1012         char *ipaddr, *buf, *tok, *dev = NULL;
1013         const char *delim = " ";
1014         struct sockaddr_in *ip;
1015         struct sockaddr_in si;
1016         struct addrinfo *res;
1017         struct process *p;
1018         int rc;
1019
1020         /* Note: IPv4 only */
1021         rc = inet_pton(AF_INET, url->host, &(si.sin_addr));
1022         if (rc > 0) {
1023                 ipaddr = url->host;
1024         } else {
1025                 /* need to turn hostname into a valid IP */
1026                 rc = getaddrinfo(url->host, NULL, NULL, &res);
1027                 if (rc) {
1028                         pb_debug("%s: Invalid URL\n",__func__);
1029                         return NULL;
1030                 }
1031                 ipaddr = talloc_array(ctx,char,INET_ADDRSTRLEN);
1032                 ip = (struct sockaddr_in *) res->ai_addr;
1033                 inet_ntop(AF_INET, &(ip->sin_addr), ipaddr, INET_ADDRSTRLEN);
1034                 freeaddrinfo(res);
1035         }
1036
1037         const char *argv[] = {
1038                 pb_system_apps.ip,
1039                 "route", "show", "to", "match",
1040                 ipaddr,
1041                 NULL
1042         };
1043
1044         p = process_create(ctx);
1045
1046         p->path = pb_system_apps.ip;
1047         p->argv = argv;
1048         p->keep_stdout = true;
1049
1050         rc = process_run_sync(p);
1051
1052         if (rc || p->exit_status) {
1053                 /* ip has complained for some reason; most likely
1054                  * there is no route to the host - bail out */
1055                 pb_debug("%s: `ip` returns non-zero exit status\n", __func__);
1056                 pb_debug("ip buf: %s\n", p->stdout_buf);
1057                 process_release(p);
1058                 return NULL;
1059         }
1060
1061         buf = p->stdout_buf;
1062         /* If a route is found, ip-route output will be of the form
1063          * "... dev DEVNAME ... " */
1064         tok = strtok(buf, delim);
1065         while (tok) {
1066                 if (!strcmp(tok, "dev")) {
1067                         tok = strtok(NULL, delim);
1068                         dev = talloc_strdup(ctx, tok);
1069                         break;
1070                 }
1071                 tok = strtok(NULL, delim);
1072         }
1073
1074         process_release(p);
1075         if (dev)
1076                 pb_debug("%s: Found interface '%s'\n", __func__,dev);
1077         return dev;
1078 }
1079
1080 void device_handler_process_url(struct device_handler *handler,
1081                 const char *url, const char *mac, const char *ip)
1082 {
1083         struct discover_context *ctx;
1084         struct discover_device *dev;
1085         struct status *status;
1086         struct pb_url *pb_url;
1087         struct event *event;
1088         struct param *param;
1089
1090         status = talloc(handler, struct status);
1091         status->type = STATUS_ERROR;
1092
1093         if (!handler->network) {
1094                 status->message = talloc_asprintf(handler,
1095                                         _("No network configured"));
1096                 goto msg;
1097         }
1098
1099         event = talloc(handler, struct event);
1100         event->type = EVENT_TYPE_USER;
1101         event->action = EVENT_ACTION_URL;
1102
1103         if (url[strlen(url) - 1] == '/') {
1104                 event->params = talloc_array(event, struct param, 3);
1105                 param = &event->params[0];
1106                 param->name = talloc_strdup(event, "pxepathprefix");
1107                 param->value = talloc_strdup(event, url);
1108                 param = &event->params[1];
1109                 param->name = talloc_strdup(event, "mac");
1110                 param->value = talloc_strdup(event, mac);
1111                 param = &event->params[2];
1112                 param->name = talloc_strdup(event, "ip");
1113                 param->value = talloc_strdup(event, ip);
1114                 event->n_params = 3;
1115         } else {
1116                 event->params = talloc_array(event, struct param, 1);
1117                 param = &event->params[0];
1118                 param->name = talloc_strdup(event, "pxeconffile");
1119                 param->value = talloc_strdup(event, url);
1120                 event->n_params = 1;
1121         }
1122
1123         pb_url = pb_url_parse(event, event->params->value);
1124         if (!pb_url || (pb_url->scheme != pb_url_file && !pb_url->host)) {
1125                 status->message = talloc_asprintf(handler,
1126                                         _("Invalid config URL!"));
1127                 goto msg;
1128         }
1129
1130         if (pb_url->scheme == pb_url_file)
1131                 event->device = talloc_asprintf(event, "local");
1132         else
1133                 event->device = device_from_addr(event, pb_url);
1134
1135         if (!event->device) {
1136                 status->message = talloc_asprintf(status,
1137                                         _("Unable to route to host %s"),
1138                                         pb_url->host);
1139                 goto msg;
1140         }
1141
1142         dev = discover_device_create(handler, mac, event->device);
1143         if (pb_url->scheme == pb_url_file)
1144                 dev->device->type = DEVICE_TYPE_ANY;
1145         ctx = device_handler_discover_context_create(handler, dev);
1146         talloc_steal(ctx, event);
1147         ctx->event = event;
1148
1149         iterate_parsers(ctx);
1150
1151         device_handler_discover_context_commit(handler, ctx);
1152
1153         talloc_unlink(handler, ctx);
1154
1155         status->type = STATUS_INFO;
1156         status->message = talloc_asprintf(status, _("Config file %s parsed"),
1157                                         pb_url->file);
1158 msg:
1159         device_handler_status(handler, status);
1160         talloc_free(status);
1161 }
1162
1163 #ifndef PETITBOOT_TEST
1164
1165 /**
1166  * context_commit - Commit a temporary discovery context to the handler,
1167  * and notify the clients about any new options / devices
1168  */
1169 void device_handler_discover_context_commit(struct device_handler *handler,
1170                 struct discover_context *ctx)
1171 {
1172         struct discover_device *dev = ctx->device;
1173         struct discover_boot_option *opt, *tmp;
1174
1175         if (!device_lookup_by_uuid(handler, dev->uuid))
1176                 device_handler_add_device(handler, dev);
1177
1178         /* move boot options from the context to the device */
1179         list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
1180                 list_remove(&opt->list);
1181
1182                 /* All boot options need at least a kernel image */
1183                 if (!opt->boot_image || !opt->boot_image->url) {
1184                         pb_log("boot option %s is missing boot image, ignoring\n",
1185                                 opt->option->id);
1186                         talloc_free(opt);
1187                         continue;
1188                 }
1189
1190                 if (boot_option_resolve(opt, handler)) {
1191                         pb_log("boot option %s is resolved, "
1192                                         "sending to clients\n",
1193                                         opt->option->id);
1194                         list_add_tail(&dev->boot_options, &opt->list);
1195                         talloc_steal(dev, opt);
1196                         boot_option_finalise(handler, opt);
1197                         notify_boot_option(handler, opt);
1198                 } else {
1199                         if (!opt->source->resolve_resource) {
1200                                 pb_log("parser %s gave us an unresolved "
1201                                         "resource (%s), but no way to "
1202                                         "resolve it\n",
1203                                         opt->source->name, opt->option->id);
1204                                 talloc_free(opt);
1205                         } else {
1206                                 pb_log("boot option %s is unresolved, "
1207                                                 "adding to queue\n",
1208                                                 opt->option->id);
1209                                 list_add(&handler->unresolved_boot_options,
1210                                                 &opt->list);
1211                                 talloc_steal(handler, opt);
1212                         }
1213                 }
1214         }
1215 }
1216
1217 static void device_handler_update_lang(const char *lang)
1218 {
1219         const char *cur_lang;
1220
1221         if (!lang)
1222                 return;
1223
1224         cur_lang = setlocale(LC_ALL, NULL);
1225         if (cur_lang && !strcmp(cur_lang, lang))
1226                 return;
1227
1228         setlocale(LC_ALL, lang);
1229 }
1230
1231 static int device_handler_init_sources(struct device_handler *handler)
1232 {
1233         /* init our device sources: udev, network and user events */
1234         handler->udev = udev_init(handler, handler->waitset);
1235         if (!handler->udev)
1236                 return -1;
1237
1238         handler->network = network_init(handler, handler->waitset,
1239                         handler->dry_run);
1240         if (!handler->network)
1241                 return -1;
1242
1243         handler->user_event = user_event_init(handler, handler->waitset);
1244         if (!handler->user_event)
1245                 return -1;
1246
1247         return 0;
1248 }
1249
1250 static void device_handler_reinit_sources(struct device_handler *handler)
1251 {
1252         /* if we haven't initialised sources previously (becuase we started in
1253          * safe mode), then init once here. */
1254         if (!(handler->udev || handler->network || handler->user_event)) {
1255                 device_handler_init_sources(handler);
1256                 return;
1257         }
1258
1259         udev_reinit(handler->udev);
1260
1261         network_shutdown(handler->network);
1262         handler->network = network_init(handler, handler->waitset,
1263                         handler->dry_run);
1264 }
1265
1266 static inline const char *get_device_path(struct discover_device *dev)
1267 {
1268         return dev->ramdisk ? dev->ramdisk->snapshot : dev->device_path;
1269 }
1270
1271 static char *check_subvols(struct discover_device *dev)
1272 {
1273         const char *fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1274         struct stat sb;
1275         char *path;
1276         int rc;
1277
1278         if (strncmp(fstype, "btrfs", strlen("btrfs")))
1279                 return dev->mount_path;
1280
1281         /* On btrfs a device's root may be under a subvolume path */
1282         path = join_paths(dev, dev->mount_path, "@");
1283         rc = stat(path, &sb);
1284         if (!rc && S_ISDIR(sb.st_mode)) {
1285                 pb_debug("Using '%s' for btrfs root path\n", path);
1286                 return path;
1287         }
1288
1289         talloc_free(path);
1290         return dev->mount_path;
1291 }
1292
1293 static bool check_existing_mount(struct discover_device *dev)
1294 {
1295         struct stat devstat, mntstat;
1296         const char *device_path;
1297         struct mntent *mnt;
1298         FILE *fp;
1299         int rc;
1300
1301         device_path = get_device_path(dev);
1302
1303         rc = stat(device_path, &devstat);
1304         if (rc) {
1305                 pb_debug("%s: stat failed: %s\n", __func__, strerror(errno));
1306                 return false;
1307         }
1308
1309         if (!S_ISBLK(devstat.st_mode)) {
1310                 pb_debug("%s: %s isn't a block device?\n", __func__,
1311                                 dev->device_path);
1312                 return false;
1313         }
1314
1315         fp = fopen("/proc/self/mounts", "r");
1316
1317         for (;;) {
1318                 mnt = getmntent(fp);
1319                 if (!mnt)
1320                         break;
1321
1322                 if (!mnt->mnt_fsname || mnt->mnt_fsname[0] != '/')
1323                         continue;
1324
1325                 rc = stat(mnt->mnt_fsname, &mntstat);
1326                 if (rc)
1327                         continue;
1328
1329                 if (!S_ISBLK(mntstat.st_mode))
1330                         continue;
1331
1332                 if (mntstat.st_rdev == devstat.st_rdev) {
1333                         dev->mount_path = talloc_strdup(dev, mnt->mnt_dir);
1334                         dev->root_path = check_subvols(dev);
1335                         dev->mounted_rw = !!hasmntopt(mnt, "rw");
1336                         dev->mounted = true;
1337                         dev->unmount = false;
1338
1339                         pb_debug("%s: %s is already mounted (r%c) at %s\n",
1340                                         __func__, dev->device_path,
1341                                         dev->mounted_rw ? 'w' : 'o',
1342                                         mnt->mnt_dir);
1343                         break;
1344                 }
1345         }
1346
1347         fclose(fp);
1348
1349         return mnt != NULL;
1350 }
1351
1352 /*
1353  * Attempt to mount a filesystem safely, while handling certain filesytem-
1354  * specific options
1355  */
1356 static int try_mount(const char *device_path, const char *mount_path,
1357                              const char *fstype, unsigned long flags,
1358                              bool have_snapshot)
1359 {
1360         const char *fs, *safe_opts;
1361         int rc;
1362
1363         /* Mount ext3 as ext4 instead so 'norecovery' can be used */
1364         if (strncmp(fstype, "ext3", strlen("ext3")) == 0) {
1365                 pb_debug("Mounting ext3 filesystem as ext4\n");
1366                 fs = "ext4";
1367         } else
1368                 fs = fstype;
1369
1370         if (strncmp(fs, "xfs", strlen("xfs")) == 0 ||
1371             strncmp(fs, "ext4", strlen("ext4")) == 0)
1372                 safe_opts = "norecovery";
1373         else
1374                 safe_opts = NULL;
1375
1376         errno = 0;
1377         /* If no snapshot is available don't attempt recovery */
1378         if (!have_snapshot)
1379                 return mount(device_path, mount_path, fs, flags, safe_opts);
1380
1381         rc = mount(device_path, mount_path, fs, flags, NULL);
1382
1383         if (!rc)
1384                 return rc;
1385
1386         /* Mounting failed; some filesystems will fail to mount if a recovery
1387          * journal exists (eg. cross-endian XFS), so try again with norecovery
1388          * where that option is available.
1389          * If mounting read-write just return the error as norecovery is not a
1390          * valid option */
1391         if ((flags & MS_RDONLY) != MS_RDONLY || !safe_opts)
1392                 return rc;
1393
1394         errno = 0;
1395         return mount(device_path, mount_path, fs, flags, safe_opts);
1396 }
1397
1398 static int mount_device(struct discover_device *dev)
1399 {
1400         const char *fstype, *device_path;
1401         int rc;
1402
1403         if (!dev->device_path)
1404                 return -1;
1405
1406         if (dev->mounted)
1407                 return 0;
1408
1409         if (check_existing_mount(dev))
1410                 return 0;
1411
1412         fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1413         if (!fstype)
1414                 return 0;
1415
1416         dev->mount_path = join_paths(dev, mount_base(),
1417                                         dev->device_path);
1418
1419         if (pb_mkdir_recursive(dev->mount_path)) {
1420                 pb_log("couldn't create mount directory %s: %s\n",
1421                                 dev->mount_path, strerror(errno));
1422                 goto err_free;
1423         }
1424
1425         device_path = get_device_path(dev);
1426
1427         pb_log("mounting device %s read-only\n", dev->device_path);
1428         rc = try_mount(device_path, dev->mount_path, fstype,
1429                        MS_RDONLY | MS_SILENT, dev->ramdisk);
1430
1431         if (!rc) {
1432                 dev->mounted = true;
1433                 dev->mounted_rw = false;
1434                 dev->unmount = true;
1435                 dev->root_path = check_subvols(dev);
1436                 return 0;
1437         }
1438
1439         pb_log("couldn't mount device %s: mount failed: %s\n",
1440                         device_path, strerror(errno));
1441
1442         /* If mount fails clean up any snapshot */
1443         devmapper_destroy_snapshot(dev);
1444
1445         pb_rmdir_recursive(mount_base(), dev->mount_path);
1446 err_free:
1447         talloc_free(dev->mount_path);
1448         dev->mount_path = NULL;
1449         return -1;
1450 }
1451
1452 static int umount_device(struct discover_device *dev)
1453 {
1454         const char *device_path;
1455         int rc;
1456
1457         if (!dev->mounted || !dev->unmount)
1458                 return 0;
1459
1460         device_path = get_device_path(dev);
1461
1462         pb_log("unmounting device %s\n", device_path);
1463         rc = umount(dev->mount_path);
1464         if (rc)
1465                 return -1;
1466
1467         dev->mounted = false;
1468         devmapper_destroy_snapshot(dev);
1469
1470         pb_rmdir_recursive(mount_base(), dev->mount_path);
1471
1472         talloc_free(dev->mount_path);
1473         dev->mount_path = NULL;
1474         dev->root_path = NULL;
1475
1476         return 0;
1477 }
1478
1479 int device_request_write(struct discover_device *dev, bool *release)
1480 {
1481         const char *fstype, *device_path;
1482         const struct config *config;
1483         int rc;
1484
1485         *release = false;
1486
1487         config = config_get();
1488         if (!config->allow_writes)
1489                 return -1;
1490
1491         if (!dev->mounted)
1492                 return -1;
1493
1494         if (dev->mounted_rw)
1495                 return 0;
1496
1497         fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1498
1499         device_path = get_device_path(dev);
1500
1501         pb_log("remounting device %s read-write\n", device_path);
1502
1503         rc = umount(dev->mount_path);
1504         if (rc) {
1505                 pb_log("Failed to unmount %s: %s\n",
1506                        dev->mount_path, strerror(errno));
1507                 return -1;
1508         }
1509
1510         rc = try_mount(device_path, dev->mount_path, fstype,
1511                        MS_SILENT, dev->ramdisk);
1512         if (rc)
1513                 goto mount_ro;
1514
1515         dev->mounted_rw = true;
1516         *release = true;
1517         return 0;
1518
1519 mount_ro:
1520         pb_log("Unable to remount device %s read-write: %s\n",
1521                device_path, strerror(errno));
1522         rc = try_mount(device_path, dev->mount_path, fstype,
1523                        MS_RDONLY | MS_SILENT, dev->ramdisk);
1524         if (rc)
1525                 pb_log("Unable to recover mount for %s: %s\n",
1526                        device_path, strerror(errno));
1527         return -1;
1528 }
1529
1530 void device_release_write(struct discover_device *dev, bool release)
1531 {
1532         const char *fstype, *device_path;
1533
1534         if (!release)
1535                 return;
1536
1537         device_path = get_device_path(dev);
1538
1539         fstype = discover_device_get_param(dev, "ID_FS_TYPE");
1540
1541         pb_log("remounting device %s read-only\n", device_path);
1542
1543         if (umount(dev->mount_path)) {
1544                 pb_log("Failed to unmount %s\n", dev->mount_path);
1545                 return;
1546         }
1547         dev->mounted_rw = dev->mounted = false;
1548
1549         if (dev->ramdisk) {
1550                 devmapper_merge_snapshot(dev);
1551                 /* device_path becomes stale after merge */
1552                 device_path = get_device_path(dev);
1553         }
1554
1555         if (try_mount(device_path, dev->mount_path, fstype,
1556                        MS_RDONLY | MS_SILENT, dev->ramdisk))
1557                 pb_log("Failed to remount %s read-only: %s\n",
1558                        device_path, strerror(errno));
1559         else
1560                 dev->mounted = true;
1561 }
1562
1563 void device_sync_snapshots(struct device_handler *handler, const char *device)
1564 {
1565         struct discover_device *dev = NULL;
1566         unsigned int i;
1567
1568         if (device) {
1569                 /* Find matching device and sync */
1570                 dev = device_lookup_by_name(handler, device);
1571                 if (!dev) {
1572                         pb_log("%s: device name '%s' unrecognised\n",
1573                                 __func__, device);
1574                         return;
1575                 }
1576                 if (dev->ramdisk)
1577                         device_release_write(dev, true);
1578                 else
1579                         pb_log("%s has no snapshot to merge, skipping\n",
1580                                 dev->device->id);
1581                 return;
1582         }
1583
1584         /* Otherwise sync all relevant devices */
1585         for (i = 0; i < handler->n_devices; i++) {
1586                 dev = handler->devices[i];
1587                 if (dev->device->type != DEVICE_TYPE_DISK &&
1588                         dev->device->type != DEVICE_TYPE_USB)
1589                         continue;
1590                 if (dev->ramdisk)
1591                         device_release_write(dev, true);
1592                 else
1593                         pb_log("%s has no snapshot to merge, skipping\n",
1594                                 dev->device->id);
1595         }
1596 }
1597
1598 #else
1599
1600 void device_handler_discover_context_commit(
1601                 struct device_handler *handler __attribute__((unused)),
1602                 struct discover_context *ctx __attribute__((unused)))
1603 {
1604         pb_log("%s stubbed out for test cases\n", __func__);
1605 }
1606
1607 static void device_handler_update_lang(const char *lang __attribute__((unused)))
1608 {
1609 }
1610
1611 static int device_handler_init_sources(
1612                 struct device_handler *handler __attribute__((unused)))
1613 {
1614         return 0;
1615 }
1616
1617 static void device_handler_reinit_sources(
1618                 struct device_handler *handler __attribute__((unused)))
1619 {
1620 }
1621
1622 static int umount_device(struct discover_device *dev __attribute__((unused)))
1623 {
1624         return 0;
1625 }
1626
1627 static int __attribute__((unused)) mount_device(
1628                 struct discover_device *dev __attribute__((unused)))
1629 {
1630         return 0;
1631 }
1632
1633 int device_request_write(struct discover_device *dev __attribute__((unused)),
1634                 bool *release)
1635 {
1636         *release = true;
1637         return 0;
1638 }
1639
1640 void device_release_write(struct discover_device *dev __attribute__((unused)),
1641         bool release __attribute__((unused)))
1642 {
1643 }
1644
1645 void device_sync_snapshots(
1646                 struct device_handler *handler __attribute__((unused)),
1647                 const char *device __attribute__((unused)))
1648 {
1649 }
1650
1651 #endif