git.meshlink.io Git - catta/blob - avahi-client/client.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of avahi.
   5
   6   avahi is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   avahi is distributed in the hope that it will be useful, but WITHOUT
  12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  14   Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with avahi; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29
  30 #include <dbus/dbus.h>
  31
  32 #include <avahi-common/dbus.h>
  33 #include <avahi-common/llist.h>
  34 #include <avahi-common/error.h>
  35 #include <avahi-common/dbus.h>
  36 #include <avahi-common/malloc.h>
  37 #include <avahi-common/dbus-watch-glue.h>
  38
  39 #include "client.h"
  40 #include "internal.h"
  41
  42 static int init_server(AvahiClient *client, int *ret_error);
  43
  44 int avahi_client_set_errno (AvahiClient *client, int error) {
  45     assert(client);
  46
  47     return client->error = error;
  48 }
  49
  50 int avahi_client_set_dbus_error(AvahiClient *client, DBusError *error) {
  51     assert(client);
  52     assert(error);
  53
  54     return avahi_client_set_errno(client, avahi_error_dbus_to_number(error->name));
  55 }
  56
  57 static void client_set_state (AvahiClient *client, AvahiServerState state) {
  58     assert(client);
  59
  60     if (client->state == state)
  61         return;
  62
  63     client->state = state;
  64
  65     switch (client->state) {
  66         case AVAHI_CLIENT_FAILURE:
  67             if (client->bus) {
  68                 dbus_connection_disconnect(client->bus);
  69                 dbus_connection_unref(client->bus);
  70                 client->bus = NULL;
  71             }
  72
  73             /* Fall through */
  74
  75         case AVAHI_CLIENT_S_COLLISION:
  76         case AVAHI_CLIENT_S_REGISTERING:
  77
  78             /* Clear cached strings */
  79             avahi_free(client->host_name);
  80             avahi_free(client->host_name_fqdn);
  81             avahi_free(client->domain_name);
  82
  83             client->host_name =  NULL;
  84             client->host_name_fqdn = NULL;
  85             client->domain_name = NULL;
  86             break;
  87
  88         case AVAHI_CLIENT_S_RUNNING:
  89         case AVAHI_CLIENT_CONNECTING:
  90             break;
  91
  92     }
  93
  94     if (client->callback)
  95         client->callback (client, state, client->userdata);
  96 }
  97
  98 static DBusHandlerResult filter_func(DBusConnection *bus, DBusMessage *message, void *userdata) {
  99     AvahiClient *client = userdata;
 100     DBusError error;
 101
 102     assert(bus);
 103     assert(message);
 104
 105     dbus_error_init(&error);
 106
 107 /*     fprintf(stderr, "dbus: interface=%s, path=%s, member=%s\n", */
 108 /*             dbus_message_get_interface (message), */
 109 /*             dbus_message_get_path (message), */
 110 /*             dbus_message_get_member (message)); */
 111
 112     if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
 113
 114         /* The DBUS server died or kicked us */
 115         avahi_client_set_errno(client, AVAHI_ERR_DISCONNECTED);
 116         goto fail;
 117
 118     } else if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameAcquired")) {
 119
 120         /* Ignore this message */
 121
 122     } else if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
 123         char *name, *old, *new;
 124
 125         if (!dbus_message_get_args(
 126                   message, &error,
 127                   DBUS_TYPE_STRING, &name,
 128                   DBUS_TYPE_STRING, &old,
 129                   DBUS_TYPE_STRING, &new,
 130                   DBUS_TYPE_INVALID) || dbus_error_is_set(&error)) {
 131
 132             fprintf(stderr, "WARNING: Failed to parse NameOwnerChanged signal: %s\n", error.message);
 133             avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 134             goto fail;
 135         }
 136
 137         if (strcmp(name, AVAHI_DBUS_NAME) == 0) {
 138
 139             if (avahi_client_is_connected(client)) {
 140
 141                 /* Regardless if the server lost or acquired its name or
 142                  * if the name was transfered: our services are no longer
 143                  * available, so we disconnect ourselves */
 144                 avahi_client_set_errno(client, AVAHI_ERR_DISCONNECTED);
 145                 goto fail;
 146
 147             } else if (client->state == AVAHI_CLIENT_CONNECTING && (!old || *old == 0)) {
 148                 int ret;
 149
 150                 /* Server appeared */
 151
 152                 if ((ret = init_server(client, NULL)) < 0) {
 153                     avahi_client_set_errno(client, ret);
 154                     goto fail;
 155                 }
 156             }
 157         }
 158
 159     } else if (!avahi_client_is_connected(client)) {
 160
 161         /* Ignore messages we get in unconnected state */
 162
 163     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_SERVER, "StateChanged")) {
 164         int32_t state;
 165         char *e = NULL;
 166         int c;
 167
 168         if (!dbus_message_get_args(
 169                   message, &error,
 170                   DBUS_TYPE_INT32, &state,
 171                   DBUS_TYPE_STRING, &e,
 172                   DBUS_TYPE_INVALID) || dbus_error_is_set (&error)) {
 173
 174             fprintf(stderr, "WARNING: Failed to parse Server.StateChanged signal: %s\n", error.message);
 175             avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 176             goto fail;
 177         }
 178
 179         if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
 180             avahi_client_set_errno(client, c);
 181
 182         client_set_state(client, (AvahiClientState) state);
 183
 184     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_ENTRY_GROUP, "StateChanged")) {
 185         const char *path;
 186         AvahiEntryGroup *g;
 187         path = dbus_message_get_path(message);
 188
 189         for (g = client->groups; g; g = g->groups_next)
 190             if (strcmp(g->path, path) == 0)
 191                 break;
 192
 193         if (g) {
 194             int32_t state;
 195             char *e;
 196             int c;
 197
 198             if (!dbus_message_get_args(
 199                       message, &error,
 200                       DBUS_TYPE_INT32, &state,
 201                       DBUS_TYPE_STRING, &e,
 202                       DBUS_TYPE_INVALID) ||
 203                 dbus_error_is_set(&error)) {
 204
 205                 fprintf(stderr, "WARNING: Failed to parse EntryGroup.StateChanged signal: %s\n", error.message);
 206                 avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 207                 goto fail;
 208             }
 209
 210             if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
 211                 avahi_client_set_errno(client, c);
 212
 213             avahi_entry_group_set_state(g, state);
 214         }
 215
 216     } else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemNew"))
 217         return avahi_domain_browser_event(client, AVAHI_BROWSER_NEW, message);
 218     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemRemove"))
 219         return avahi_domain_browser_event(client, AVAHI_BROWSER_REMOVE, message);
 220     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "CacheExhausted"))
 221         return avahi_domain_browser_event(client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 222     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "AllForNow"))
 223         return avahi_domain_browser_event(client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 224     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "Failure"))
 225         return avahi_domain_browser_event(client, AVAHI_BROWSER_FAILURE, message);
 226
 227     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemNew"))
 228         return avahi_service_type_browser_event (client, AVAHI_BROWSER_NEW, message);
 229     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemRemove"))
 230         return avahi_service_type_browser_event (client, AVAHI_BROWSER_REMOVE, message);
 231     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "CacheExhausted"))
 232         return avahi_service_type_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 233     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "AllForNow"))
 234         return avahi_service_type_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 235     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "Failure"))
 236         return avahi_service_type_browser_event (client, AVAHI_BROWSER_FAILURE, message);
 237
 238     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemNew"))
 239         return avahi_service_browser_event (client, AVAHI_BROWSER_NEW, message);
 240     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemRemove"))
 241         return avahi_service_browser_event (client, AVAHI_BROWSER_REMOVE, message);
 242     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "CacheExhausted"))
 243         return avahi_service_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 244     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "AllForNow"))
 245         return avahi_service_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 246     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "Failure"))
 247         return avahi_service_browser_event (client, AVAHI_BROWSER_FAILURE, message);
 248
 249     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Found"))
 250         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 251     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Failure"))
 252         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 253
 254     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Found"))
 255         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 256     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Failure"))
 257         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 258
 259     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Found"))
 260         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 261     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Failure"))
 262         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 263     else {
 264
 265         fprintf(stderr, "WARNING: Unhandled message: interface=%s, path=%s, member=%s\n",
 266                dbus_message_get_interface(message),
 267                dbus_message_get_path(message),
 268                dbus_message_get_member(message));
 269
 270         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 271     }
 272
 273     return DBUS_HANDLER_RESULT_HANDLED;
 274
 275 fail:
 276
 277     if (dbus_error_is_set(&error)) {
 278         avahi_client_set_errno(client, avahi_error_dbus_to_number(error.name));
 279         dbus_error_free(&error);
 280     }
 281
 282     client_set_state(client, AVAHI_CLIENT_FAILURE);
 283
 284     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 285 }
 286
 287 static int get_server_state(AvahiClient *client, int *ret_error) {
 288     DBusMessage *message = NULL, *reply = NULL;
 289     DBusError error;
 290     int32_t state;
 291     int e = AVAHI_ERR_NO_MEMORY;
 292
 293     assert(client);
 294
 295     dbus_error_init(&error);
 296
 297     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetState")))
 298         goto fail;
 299
 300     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 301
 302     if (!reply || dbus_error_is_set (&error))
 303         goto fail;
 304
 305     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_INT32, &state, DBUS_TYPE_INVALID) ||
 306         dbus_error_is_set (&error))
 307         goto fail;
 308
 309     client_set_state(client, (AvahiServerState) state);
 310
 311     dbus_message_unref(message);
 312     dbus_message_unref(reply);
 313
 314     return AVAHI_OK;
 315
 316 fail:
 317     if (dbus_error_is_set(&error)) {
 318         e = avahi_error_dbus_to_number (error.name);
 319         dbus_error_free(&error);
 320     }
 321
 322     if (ret_error)
 323         *ret_error = e;
 324
 325     if (message)
 326         dbus_message_unref(message);
 327     if (reply)
 328         dbus_message_unref(reply);
 329
 330     return e;
 331 }
 332
 333 static int check_version(AvahiClient *client, int *ret_error) {
 334     DBusMessage *message = NULL, *reply  = NULL;
 335     DBusError error;
 336     char *version;
 337     int e = AVAHI_ERR_NO_MEMORY;
 338
 339     assert(client);
 340
 341     dbus_error_init(&error);
 342
 343     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetVersionString")))
 344         goto fail;
 345
 346     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 347
 348     if (!reply || dbus_error_is_set (&error))
 349         goto fail;
 350
 351     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &version, DBUS_TYPE_INVALID) ||
 352         dbus_error_is_set (&error))
 353         goto fail;
 354
 355     if (strcmp(version, PACKAGE_STRING) != 0) {
 356         e = AVAHI_ERR_VERSION_MISMATCH;
 357         goto fail;
 358     }
 359
 360     dbus_message_unref(message);
 361     dbus_message_unref(reply);
 362
 363     return AVAHI_OK;
 364
 365 fail:
 366     if (dbus_error_is_set(&error)) {
 367         e = avahi_error_dbus_to_number (error.name);
 368         dbus_error_free(&error);
 369     }
 370
 371     if (ret_error)
 372         *ret_error = e;
 373
 374     if (message)
 375         dbus_message_unref(message);
 376     if (reply)
 377         dbus_message_unref(reply);
 378
 379     return e;
 380 }
 381
 382 static int init_server(AvahiClient *client, int *ret_error) {
 383     int r;
 384
 385     if ((r = check_version(client, ret_error)) < 0)
 386         return r;
 387
 388     if ((r = get_server_state(client, ret_error)) < 0)
 389         return r;
 390
 391     return AVAHI_OK;
 392 }
 393
 394 /* This function acts like dbus_bus_get but creates a private
 395  * connection instead */
 396 static DBusConnection* avahi_dbus_bus_get(DBusError *error) {
 397     DBusConnection *c;
 398     const char *a;
 399
 400     if (!(a = getenv("DBUS_SYSTEM_BUS_ADDRESS")) || !*a)
 401         a = DBUS_SYSTEM_BUS_DEFAULT_ADDRESS;
 402
 403     if (!(c = dbus_connection_open_private(a, error)))
 404         return NULL;
 405
 406     dbus_connection_set_exit_on_disconnect(c, FALSE);
 407
 408     if (!dbus_bus_register(c, error)) {
 409         dbus_connection_close(c);
 410         dbus_connection_unref(c);
 411         return NULL;
 412     }
 413
 414     return c;
 415 }
 416
 417 AvahiClient *avahi_client_new(const AvahiPoll *poll_api, AvahiClientFlags flags, AvahiClientCallback callback, void *userdata, int *ret_error) {
 418     AvahiClient *client = NULL;
 419     DBusError error;
 420
 421     dbus_error_init(&error);
 422
 423     if (!(client = avahi_new(AvahiClient, 1))) {
 424         if (ret_error)
 425             *ret_error = AVAHI_ERR_NO_MEMORY;
 426         goto fail;
 427     }
 428
 429     client->poll_api = poll_api;
 430     client->error = AVAHI_OK;
 431     client->callback = callback;
 432     client->userdata = userdata;
 433     client->state = (AvahiClientState) -1;
 434     client->flags = flags;
 435
 436     client->host_name = NULL;
 437     client->host_name_fqdn = NULL;
 438     client->domain_name = NULL;
 439     client->version_string = NULL;
 440     client->local_service_cookie_valid = 0;
 441
 442     AVAHI_LLIST_HEAD_INIT(AvahiEntryGroup, client->groups);
 443     AVAHI_LLIST_HEAD_INIT(AvahiDomainBrowser, client->domain_browsers);
 444     AVAHI_LLIST_HEAD_INIT(AvahiServiceBrowser, client->service_browsers);
 445     AVAHI_LLIST_HEAD_INIT(AvahiServiceTypeBrowser, client->service_type_browsers);
 446     AVAHI_LLIST_HEAD_INIT(AvahiServiceResolver, client->service_resolvers);
 447     AVAHI_LLIST_HEAD_INIT(AvahiHostNameResolver, client->host_name_resolvers);
 448     AVAHI_LLIST_HEAD_INIT(AvahiAddressResolver, client->address_resolvers);
 449
 450     if (!(client->bus = avahi_dbus_bus_get(&error)) || dbus_error_is_set(&error)) {
 451         if (ret_error)
 452             *ret_error = AVAHI_ERR_DBUS_ERROR;
 453         goto fail;
 454     }
 455
 456     if (avahi_dbus_connection_glue(client->bus, poll_api) < 0) {
 457         if (ret_error)
 458             *ret_error = AVAHI_ERR_NO_MEMORY; /* Not optimal */
 459         goto fail;
 460     }
 461
 462     if (!dbus_connection_add_filter (client->bus, filter_func, client, NULL)) {
 463         if (ret_error)
 464             *ret_error = AVAHI_ERR_NO_MEMORY;
 465         goto fail;
 466     }
 467
 468     dbus_bus_add_match(
 469         client->bus,
 470         "type='signal', "
 471         "interface='" AVAHI_DBUS_INTERFACE_SERVER "', "
 472         "sender='" AVAHI_DBUS_NAME "', "
 473         "path='" AVAHI_DBUS_PATH_SERVER "'",
 474         &error);
 475
 476     if (dbus_error_is_set(&error))
 477         goto fail;
 478
 479     dbus_bus_add_match (
 480         client->bus,
 481         "type='signal', "
 482         "interface='" DBUS_INTERFACE_DBUS "', "
 483         "sender='" DBUS_SERVICE_DBUS "', "
 484         "path='" DBUS_PATH_DBUS "'",
 485         &error);
 486
 487     if (dbus_error_is_set(&error))
 488         goto fail;
 489
 490     dbus_bus_add_match (
 491         client->bus,
 492         "type='signal', "
 493         "interface='" DBUS_INTERFACE_LOCAL "'",
 494         &error);
 495
 496     if (dbus_error_is_set(&error))
 497         goto fail;
 498
 499
 500     if (!(dbus_bus_name_has_owner(client->bus, AVAHI_DBUS_NAME, &error)) ||
 501         dbus_error_is_set(&error)) {
 502
 503         /* We free the error so its not set, that way the fail target
 504          * will return the NO_DAEMON error rather than a DBUS error */
 505         dbus_error_free(&error);
 506
 507         if (!(flags & AVAHI_CLIENT_NO_FAIL)) {
 508
 509             if (ret_error)
 510                 *ret_error = AVAHI_ERR_NO_DAEMON;
 511
 512             goto fail;
 513         }
 514
 515         /* The user doesn't want this call to fail if the daemon is not
 516          * available, so let's return succesfully */
 517         client_set_state(client, AVAHI_CLIENT_CONNECTING);
 518
 519     } else {
 520
 521         if (init_server(client, ret_error) < 0)
 522             goto fail;
 523     }
 524
 525     return client;
 526
 527 fail:
 528
 529     if (client)
 530         avahi_client_free(client);
 531
 532     if (dbus_error_is_set(&error)) {
 533
 534         if (ret_error)
 535             *ret_error = avahi_error_dbus_to_number(error.name);
 536
 537         dbus_error_free(&error);
 538     }
 539
 540     return NULL;
 541 }
 542
 543 void avahi_client_free(AvahiClient *client) {
 544     assert(client);
 545
 546     while (client->groups)
 547         avahi_entry_group_free(client->groups);
 548
 549     while (client->domain_browsers)
 550         avahi_domain_browser_free(client->domain_browsers);
 551
 552     while (client->service_browsers)
 553         avahi_service_browser_free(client->service_browsers);
 554
 555     while (client->service_type_browsers)
 556         avahi_service_type_browser_free(client->service_type_browsers);
 557
 558     while (client->service_resolvers)
 559         avahi_service_resolver_free(client->service_resolvers);
 560
 561     if (client->bus) {
 562         dbus_connection_disconnect(client->bus);
 563         dbus_connection_unref(client->bus);
 564     }
 565
 566     avahi_free(client->version_string);
 567     avahi_free(client->host_name);
 568     avahi_free(client->host_name_fqdn);
 569     avahi_free(client->domain_name);
 570
 571     avahi_free(client);
 572 }
 573
 574 static char* avahi_client_get_string_reply_and_block (AvahiClient *client, const char *method, const char *param) {
 575     DBusMessage *message = NULL, *reply = NULL;
 576     DBusError error;
 577     char *ret, *n;
 578
 579     assert(client);
 580     assert(method);
 581
 582     dbus_error_init (&error);
 583
 584     if (!(message = dbus_message_new_method_call (AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, method))) {
 585         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 586         goto fail;
 587     }
 588
 589     if (param) {
 590         if (!dbus_message_append_args (message, DBUS_TYPE_STRING, &param, DBUS_TYPE_INVALID)) {
 591             avahi_client_set_errno (client, AVAHI_ERR_NO_MEMORY);
 592             goto fail;
 593         }
 594     }
 595
 596     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 597
 598     if (!reply || dbus_error_is_set (&error))
 599         goto fail;
 600
 601     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &ret, DBUS_TYPE_INVALID) ||
 602         dbus_error_is_set (&error))
 603         goto fail;
 604
 605     if (!(n = avahi_strdup(ret))) {
 606         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 607         goto fail;
 608     }
 609
 610     dbus_message_unref(message);
 611     dbus_message_unref(reply);
 612
 613     return n;
 614
 615 fail:
 616
 617     if (message)
 618         dbus_message_unref(message);
 619     if (reply)
 620         dbus_message_unref(reply);
 621
 622     if (dbus_error_is_set(&error)) {
 623         avahi_client_set_dbus_error(client, &error);
 624         dbus_error_free(&error);
 625     }
 626
 627     return NULL;
 628 }
 629
 630 const char* avahi_client_get_version_string(AvahiClient *client) {
 631     assert(client);
 632
 633     if (!avahi_client_is_connected(client)) {
 634         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 635         return NULL;
 636     }
 637
 638     if (!client->version_string)
 639         client->version_string = avahi_client_get_string_reply_and_block(client, "GetVersionString", NULL);
 640
 641     return client->version_string;
 642 }
 643
 644 const char* avahi_client_get_domain_name(AvahiClient *client) {
 645     assert(client);
 646
 647     if (!avahi_client_is_connected(client)) {
 648         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 649         return NULL;
 650     }
 651
 652     if (!client->domain_name)
 653         client->domain_name = avahi_client_get_string_reply_and_block(client, "GetDomainName", NULL);
 654
 655     return client->domain_name;
 656 }
 657
 658 const char* avahi_client_get_host_name(AvahiClient *client) {
 659     assert(client);
 660
 661     if (!avahi_client_is_connected(client)) {
 662         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 663         return NULL;
 664     }
 665
 666     if (!client->host_name)
 667         client->host_name = avahi_client_get_string_reply_and_block(client, "GetHostName", NULL);
 668
 669     return client->host_name;
 670 }
 671
 672 const char* avahi_client_get_host_name_fqdn (AvahiClient *client) {
 673     assert(client);
 674
 675     if (!avahi_client_is_connected(client)) {
 676         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 677         return NULL;
 678     }
 679
 680     if (!client->host_name_fqdn)
 681         client->host_name_fqdn = avahi_client_get_string_reply_and_block(client, "GetHostNameFqdn", NULL);
 682
 683     return client->host_name_fqdn;
 684 }
 685
 686 AvahiClientState avahi_client_get_state(AvahiClient *client) {
 687     assert(client);
 688
 689     return client->state;
 690 }
 691
 692 int avahi_client_errno(AvahiClient *client) {
 693     assert(client);
 694
 695     return client->error;
 696 }
 697
 698 /* Just for internal use */
 699 int avahi_client_simple_method_call(AvahiClient *client, const char *path, const char *interface, const char *method) {
 700     DBusMessage *message = NULL, *reply = NULL;
 701     DBusError error;
 702     int r = AVAHI_OK;
 703
 704     dbus_error_init(&error);
 705
 706     assert(client);
 707     assert(path);
 708     assert(interface);
 709     assert(method);
 710
 711     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, path, interface, method))) {
 712         r = avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 713         goto fail;
 714     }
 715
 716     if (!(reply = dbus_connection_send_with_reply_and_block(client->bus, message, -1, &error)) ||
 717         dbus_error_is_set (&error)) {
 718         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 719         goto fail;
 720     }
 721
 722     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_INVALID) ||
 723         dbus_error_is_set (&error)) {
 724         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 725         goto fail;
 726     }
 727
 728     dbus_message_unref(message);
 729     dbus_message_unref(reply);
 730
 731     return AVAHI_OK;
 732
 733 fail:
 734     if (dbus_error_is_set(&error)) {
 735         r = avahi_client_set_dbus_error(client, &error);
 736         dbus_error_free(&error);
 737     }
 738
 739     if (message)
 740         dbus_message_unref(message);
 741
 742     if (reply)
 743         dbus_message_unref(reply);
 744
 745     return r;
 746 }
 747
 748 uint32_t avahi_client_get_local_service_cookie(AvahiClient *client) {
 749     DBusMessage *message = NULL, *reply = NULL;
 750     DBusError error;
 751     assert(client);
 752
 753     if (!avahi_client_is_connected(client)) {
 754         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 755         return AVAHI_SERVICE_COOKIE_INVALID;
 756     }
 757
 758     if (client->local_service_cookie_valid)
 759         return client->local_service_cookie;
 760
 761     dbus_error_init (&error);
 762
 763     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetLocalServiceCookie"))) {
 764         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 765         goto fail;
 766     }
 767
 768     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 769
 770     if (!reply || dbus_error_is_set (&error))
 771         goto fail;
 772
 773     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_UINT32, &client->local_service_cookie, DBUS_TYPE_INVALID) ||
 774         dbus_error_is_set (&error))
 775         goto fail;
 776
 777     dbus_message_unref(message);
 778     dbus_message_unref(reply);
 779
 780     client->local_service_cookie_valid = 1;
 781     return client->local_service_cookie;
 782
 783 fail:
 784
 785     if (message)
 786         dbus_message_unref(message);
 787     if (reply)
 788         dbus_message_unref(reply);
 789
 790     if (dbus_error_is_set(&error)) {
 791         avahi_client_set_dbus_error(client, &error);
 792         dbus_error_free(&error);
 793     }
 794
 795     return AVAHI_SERVICE_COOKIE_INVALID;
 796 }
 797
 798 int avahi_client_is_connected(AvahiClient *client) {
 799     assert(client);
 800
 801     return client->state == AVAHI_CLIENT_S_RUNNING || client->state == AVAHI_CLIENT_S_REGISTERING || client->state == AVAHI_CLIENT_S_COLLISION;
 802 }