git.meshlink.io Git - catta/blob - avahi-core/iface.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 <string.h>
  27 #include <errno.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <netinet/in.h>
  31 #include <sys/types.h>
  32 #include <sys/socket.h>
  33
  34 #include <avahi-common/error.h>
  35 #include <avahi-common/malloc.h>
  36 #include <avahi-common/domain.h>
  37
  38 #include "iface.h"
  39 #include "dns.h"
  40 #include "socket.h"
  41 #include "announce.h"
  42 #include "util.h"
  43 #include "log.h"
  44 #include "multicast-lookup.h"
  45 #include "querier.h"
  46
  47 void avahi_interface_address_update_rrs(AvahiInterfaceAddress *a, int remove_rrs) {
  48     AvahiInterfaceMonitor *m;
  49
  50     assert(a);
  51     m = a->monitor;
  52
  53     if (a->interface->announcing &&
  54         m->list_complete &&
  55         avahi_interface_address_is_relevant(a) &&
  56         !remove_rrs &&
  57         m->server->config.publish_addresses &&
  58         (m->server->state == AVAHI_SERVER_RUNNING ||
  59         m->server->state == AVAHI_SERVER_REGISTERING)) {
  60
  61         /* Fill the entry group */
  62         if (!a->entry_group)
  63             a->entry_group = avahi_s_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
  64
  65         if (!a->entry_group) /* OOM */
  66             return;
  67
  68         if (avahi_s_entry_group_is_empty(a->entry_group)) {
  69             char t[AVAHI_ADDRESS_STR_MAX];
  70             avahi_address_snprint(t, sizeof(t), &a->address);
  71
  72             avahi_log_info("Registering new address record for %s on %s.", t, a->interface->hardware->name);
  73
  74             if (avahi_server_add_address(m->server, a->entry_group, a->interface->hardware->index, a->interface->protocol, 0, NULL, &a->address) < 0) {
  75                 avahi_log_warn(__FILE__": avahi_server_add_address() failed: %s", avahi_strerror(m->server->error));
  76                 avahi_s_entry_group_free(a->entry_group);
  77                 a->entry_group = NULL;
  78                 return;
  79             }
  80
  81             avahi_s_entry_group_commit(a->entry_group);
  82         }
  83     } else {
  84
  85         /* Clear the entry group */
  86
  87         if (a->entry_group && !avahi_s_entry_group_is_empty(a->entry_group)) {
  88             char t[AVAHI_ADDRESS_STR_MAX];
  89             avahi_address_snprint(t, sizeof(t), &a->address);
  90
  91             if (avahi_s_entry_group_get_state(a->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING &&
  92                 m->server->state == AVAHI_SERVER_REGISTERING)
  93                 avahi_server_decrease_host_rr_pending(m->server);
  94
  95             avahi_log_info("Withdrawing address record for %s on %s.", t, a->interface->hardware->name);
  96
  97             avahi_s_entry_group_reset(a->entry_group);
  98         }
  99     }
 100 }
 101
 102 void avahi_interface_update_rrs(AvahiInterface *i, int remove_rrs) {
 103     AvahiInterfaceAddress *a;
 104
 105     assert(i);
 106
 107     for (a = i->addresses; a; a = a->address_next)
 108         avahi_interface_address_update_rrs(a, remove_rrs);
 109 }
 110
 111 void avahi_hw_interface_update_rrs(AvahiHwInterface *hw, int remove_rrs) {
 112     AvahiInterface *i;
 113     AvahiInterfaceMonitor *m;
 114
 115     assert(hw);
 116     m = hw->monitor;
 117
 118     for (i = hw->interfaces; i; i = i->by_hardware_next)
 119         avahi_interface_update_rrs(i, remove_rrs);
 120
 121     if (m->list_complete &&
 122         !remove_rrs &&
 123         m->server->config.publish_workstation &&
 124         (m->server->state == AVAHI_SERVER_RUNNING ||
 125         m->server->state == AVAHI_SERVER_REGISTERING)) {
 126
 127         if (!hw->entry_group)
 128             hw->entry_group = avahi_s_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
 129
 130         if (!hw->entry_group)
 131             return; /* OOM */
 132
 133         if (avahi_s_entry_group_is_empty(hw->entry_group)) {
 134             char name[AVAHI_LABEL_MAX];
 135             char *t;
 136
 137             if (!(t = avahi_format_mac_address(hw->mac_address, hw->mac_address_size)))
 138                 return; /* OOM */
 139
 140             snprintf(name, sizeof(name), "%s [%s]", m->server->host_name, t);
 141             avahi_free(t);
 142
 143             if (!name)
 144                 return; /* OOM */
 145
 146             if (avahi_server_add_service(m->server, hw->entry_group, hw->index, AVAHI_PROTO_UNSPEC, 0, name, "_workstation._tcp", NULL, NULL, 9, NULL) < 0) {
 147                 avahi_log_warn(__FILE__": avahi_server_add_service() failed: %s", avahi_strerror(m->server->error));
 148                 avahi_s_entry_group_free(hw->entry_group);
 149                 hw->entry_group = NULL;
 150             } else
 151                 avahi_s_entry_group_commit(hw->entry_group);
 152         }
 153
 154     } else {
 155
 156         if (hw->entry_group && !avahi_s_entry_group_is_empty(hw->entry_group)) {
 157
 158             if (avahi_s_entry_group_get_state(hw->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING)
 159                 avahi_server_decrease_host_rr_pending(m->server);
 160
 161             avahi_s_entry_group_reset(hw->entry_group);
 162         }
 163     }
 164 }
 165
 166 void avahi_interface_monitor_update_rrs(AvahiInterfaceMonitor *m, int remove_rrs) {
 167     AvahiHwInterface *hw;
 168
 169     assert(m);
 170
 171     for (hw = m->hw_interfaces; hw; hw = hw->hardware_next)
 172         avahi_hw_interface_update_rrs(hw, remove_rrs);
 173 }
 174
 175 static int interface_mdns_mcast_join(AvahiInterface *i, int join) {
 176     char at[AVAHI_ADDRESS_STR_MAX];
 177     assert(i);
 178
 179     assert((join && !i->mcast_joined) || (!join && i->mcast_joined));
 180
 181     if (join) {
 182         AvahiInterfaceAddress *a;
 183
 184         /* Look if there's an address with global scope */
 185         for (a = i->addresses; a; a = a->address_next)
 186             if (a->global_scope)
 187                 break;
 188
 189         /* No address with a global scope has been found, so let's use
 190          * any. */
 191         if (!a)
 192             a = i->addresses;
 193
 194         /* Hmm, there is no address available. */
 195         if (!a) {
 196             avahi_log_warn(__FILE__": interface_mdns_mcast_join() called but no local address available.");
 197             return -1;
 198         }
 199
 200         i->local_mcast_address = a->address;
 201     }
 202
 203     avahi_log_info("%s mDNS multicast group on interface %s.%s with address %s.",
 204                    join ? "Joining" : "Leaving",
 205                    i->hardware->name,
 206                    avahi_proto_to_string(i->protocol),
 207                    avahi_address_snprint(at, sizeof(at), &i->local_mcast_address));
 208
 209     if (i->protocol == AVAHI_PROTO_INET6)
 210         avahi_mdns_mcast_join_ipv6(i->monitor->server->fd_ipv6, &i->local_mcast_address.data.ipv6, i->hardware->index, join);
 211     else {
 212         assert(i->protocol == AVAHI_PROTO_INET);
 213
 214         avahi_mdns_mcast_join_ipv4(i->monitor->server->fd_ipv4, &i->local_mcast_address.data.ipv4, i->hardware->index, join);
 215     }
 216
 217     i->mcast_joined = join;
 218     return 0;
 219 }
 220
 221 static int interface_mdns_mcast_rejoin(AvahiInterface *i) {
 222     AvahiInterfaceAddress *a, *usable = NULL, *found = NULL;
 223     assert(i);
 224
 225     if (!i->mcast_joined)
 226         return 0;
 227
 228     /* Check whether old address we joined with is still available. If
 229      * not, rejoin using an other address. */
 230
 231     for (a = i->addresses; a; a = a->address_next) {
 232         if (a->global_scope && !usable)
 233             usable = a;
 234
 235         if (avahi_address_cmp(&a->address, &i->local_mcast_address) == 0) {
 236
 237             if (a->global_scope)
 238                 /* No action necessary: the address still exists and
 239                  * has global scope. */
 240                 return 0;
 241
 242             found = a;
 243         }
 244     }
 245
 246     if (found && !usable)
 247         /* No action necessary: the address still exists and no better one has been found */
 248         return 0;
 249
 250     interface_mdns_mcast_join(i, 0);
 251     return interface_mdns_mcast_join(i, 1);
 252 }
 253
 254 void avahi_interface_address_free(AvahiInterfaceAddress *a) {
 255     assert(a);
 256     assert(a->interface);
 257
 258     avahi_interface_address_update_rrs(a, 1);
 259     AVAHI_LLIST_REMOVE(AvahiInterfaceAddress, address, a->interface->addresses, a);
 260
 261     if (a->entry_group)
 262         avahi_s_entry_group_free(a->entry_group);
 263
 264     interface_mdns_mcast_rejoin(a->interface);
 265
 266     avahi_free(a);
 267 }
 268
 269 void avahi_interface_free(AvahiInterface *i, int send_goodbye) {
 270     assert(i);
 271
 272     /* Handle goodbyes and remove announcers */
 273     avahi_goodbye_interface(i->monitor->server, i, send_goodbye, 1);
 274     avahi_response_scheduler_force(i->response_scheduler);
 275     assert(!i->announcers);
 276
 277     if (i->mcast_joined)
 278         interface_mdns_mcast_join(i, 0);
 279
 280     /* Remove queriers */
 281     avahi_querier_free_all(i);
 282     avahi_hashmap_free(i->queriers_by_key);
 283
 284     /* Remove local RRs */
 285     avahi_interface_update_rrs(i, 1);
 286
 287     while (i->addresses)
 288         avahi_interface_address_free(i->addresses);
 289
 290     avahi_response_scheduler_free(i->response_scheduler);
 291     avahi_query_scheduler_free(i->query_scheduler);
 292     avahi_probe_scheduler_free(i->probe_scheduler);
 293     avahi_cache_free(i->cache);
 294
 295     AVAHI_LLIST_REMOVE(AvahiInterface, interface, i->monitor->interfaces, i);
 296     AVAHI_LLIST_REMOVE(AvahiInterface, by_hardware, i->hardware->interfaces, i);
 297
 298     avahi_free(i);
 299 }
 300
 301 void avahi_hw_interface_free(AvahiHwInterface *hw, int send_goodbye) {
 302     assert(hw);
 303
 304     avahi_hw_interface_update_rrs(hw, 1);
 305
 306     while (hw->interfaces)
 307         avahi_interface_free(hw->interfaces, send_goodbye);
 308
 309     if (hw->entry_group)
 310         avahi_s_entry_group_free(hw->entry_group);
 311
 312     AVAHI_LLIST_REMOVE(AvahiHwInterface, hardware, hw->monitor->hw_interfaces, hw);
 313     avahi_hashmap_remove(hw->monitor->hashmap, &hw->index);
 314
 315     avahi_free(hw->name);
 316     avahi_free(hw);
 317 }
 318
 319 AvahiInterface* avahi_interface_new(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, AvahiProtocol protocol) {
 320     AvahiInterface *i;
 321
 322     assert(m);
 323     assert(hw);
 324     assert(AVAHI_PROTO_VALID(protocol));
 325
 326     if (!(i = avahi_new(AvahiInterface, 1)))
 327         goto fail; /* OOM */
 328
 329     i->monitor = m;
 330     i->hardware = hw;
 331     i->protocol = protocol;
 332     i->announcing = 0;
 333     i->mcast_joined = 0;
 334
 335     AVAHI_LLIST_HEAD_INIT(AvahiInterfaceAddress, i->addresses);
 336     AVAHI_LLIST_HEAD_INIT(AvahiAnnouncer, i->announcers);
 337
 338     AVAHI_LLIST_HEAD_INIT(AvahiQuerier, i->queriers);
 339     i->queriers_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL);
 340
 341     i->cache = avahi_cache_new(m->server, i);
 342     i->response_scheduler = avahi_response_scheduler_new(i);
 343     i->query_scheduler = avahi_query_scheduler_new(i);
 344     i->probe_scheduler = avahi_probe_scheduler_new(i);
 345
 346     if (!i->cache || !i->response_scheduler || !i->query_scheduler || !i->probe_scheduler)
 347         goto fail; /* OOM */
 348
 349     AVAHI_LLIST_PREPEND(AvahiInterface, by_hardware, hw->interfaces, i);
 350     AVAHI_LLIST_PREPEND(AvahiInterface, interface, m->interfaces, i);
 351
 352     return i;
 353
 354 fail:
 355
 356     if (i) {
 357         if (i->cache)
 358             avahi_cache_free(i->cache);
 359         if (i->response_scheduler)
 360             avahi_response_scheduler_free(i->response_scheduler);
 361         if (i->query_scheduler)
 362             avahi_query_scheduler_free(i->query_scheduler);
 363         if (i->probe_scheduler)
 364             avahi_probe_scheduler_free(i->probe_scheduler);
 365     }
 366
 367     return NULL;
 368 }
 369
 370 AvahiHwInterface *avahi_hw_interface_new(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
 371     AvahiHwInterface *hw;
 372
 373     assert(m);
 374     assert(AVAHI_IF_VALID(idx));
 375
 376     if  (!(hw = avahi_new(AvahiHwInterface, 1)))
 377         return NULL;
 378
 379     hw->monitor = m;
 380     hw->name = NULL;
 381     hw->flags_ok = 0;
 382     hw->mtu = 1500;
 383     hw->index = idx;
 384     hw->mac_address_size = 0;
 385     hw->entry_group = NULL;
 386
 387     AVAHI_LLIST_HEAD_INIT(AvahiInterface, hw->interfaces);
 388     AVAHI_LLIST_PREPEND(AvahiHwInterface, hardware, m->hw_interfaces, hw);
 389
 390     avahi_hashmap_insert(m->hashmap, &hw->index, hw);
 391
 392     if (m->server->fd_ipv4 >= 0)
 393         avahi_interface_new(m, hw, AVAHI_PROTO_INET);
 394     if (m->server->fd_ipv6 >= 0)
 395         avahi_interface_new(m, hw, AVAHI_PROTO_INET6);
 396
 397     return hw;
 398 }
 399
 400 AvahiInterfaceAddress *avahi_interface_address_new(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *addr, unsigned prefix_len) {
 401     AvahiInterfaceAddress *a;
 402
 403     assert(m);
 404     assert(i);
 405
 406     if (!(a = avahi_new(AvahiInterfaceAddress, 1)))
 407         return NULL;
 408
 409     a->interface = i;
 410     a->monitor = m;
 411     a->address = *addr;
 412     a->prefix_len = prefix_len;
 413     a->global_scope = 0;
 414     a->entry_group = NULL;
 415
 416     AVAHI_LLIST_PREPEND(AvahiInterfaceAddress, address, i->addresses, a);
 417
 418     return a;
 419 }
 420
 421 void avahi_interface_check_relevant(AvahiInterface *i) {
 422     int b;
 423     AvahiInterfaceMonitor *m;
 424
 425     assert(i);
 426     m = i->monitor;
 427
 428     b = avahi_interface_is_relevant(i);
 429
 430     if (m->list_complete && b && !i->announcing) {
 431         avahi_log_info("New relevant interface %s.%s for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 432
 433         interface_mdns_mcast_join(i, 1);
 434
 435         i->announcing = 1;
 436         avahi_announce_interface(m->server, i);
 437         avahi_multicast_lookup_engine_new_interface(m->server->multicast_lookup_engine, i);
 438     } else if (!b && i->announcing) {
 439         avahi_log_info("Interface %s.%s no longer relevant for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 440
 441         interface_mdns_mcast_join(i, 0);
 442
 443         avahi_goodbye_interface(m->server, i, 0, 1);
 444         avahi_querier_free_all(i);
 445
 446         avahi_response_scheduler_clear(i->response_scheduler);
 447         avahi_query_scheduler_clear(i->query_scheduler);
 448         avahi_probe_scheduler_clear(i->probe_scheduler);
 449         avahi_cache_flush(i->cache);
 450
 451         i->announcing = 0;
 452
 453     } else
 454         interface_mdns_mcast_rejoin(i);
 455 }
 456
 457 void avahi_hw_interface_check_relevant(AvahiHwInterface *hw) {
 458     AvahiInterface *i;
 459
 460     assert(hw);
 461
 462     for (i = hw->interfaces; i; i = i->by_hardware_next)
 463         avahi_interface_check_relevant(i);
 464 }
 465
 466 void avahi_interface_monitor_check_relevant(AvahiInterfaceMonitor *m) {
 467     AvahiInterface *i;
 468
 469     assert(m);
 470
 471     for (i = m->interfaces; i; i = i->interface_next)
 472         avahi_interface_check_relevant(i);
 473 }
 474
 475 AvahiInterfaceMonitor *avahi_interface_monitor_new(AvahiServer *s) {
 476     AvahiInterfaceMonitor *m = NULL;
 477
 478     if (!(m = avahi_new0(AvahiInterfaceMonitor, 1)))
 479         return NULL; /* OOM */
 480
 481     m->server = s;
 482     m->list_complete = 0;
 483     m->hashmap = avahi_hashmap_new(avahi_int_hash, avahi_int_equal, NULL, NULL);
 484
 485     AVAHI_LLIST_HEAD_INIT(AvahiInterface, m->interfaces);
 486     AVAHI_LLIST_HEAD_INIT(AvahiHwInterface, m->hw_interfaces);
 487
 488     if (avahi_interface_monitor_init_osdep(m) < 0)
 489         goto fail;
 490
 491     return m;
 492
 493 fail:
 494     avahi_interface_monitor_free(m);
 495     return NULL;
 496 }
 497
 498 void avahi_interface_monitor_free(AvahiInterfaceMonitor *m) {
 499     assert(m);
 500
 501     while (m->hw_interfaces)
 502         avahi_hw_interface_free(m->hw_interfaces, 1);
 503
 504     assert(!m->interfaces);
 505
 506     avahi_interface_monitor_free_osdep(m);
 507
 508     if (m->hashmap)
 509         avahi_hashmap_free(m->hashmap);
 510
 511     avahi_free(m);
 512 }
 513
 514
 515 AvahiInterface* avahi_interface_monitor_get_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx, AvahiProtocol protocol) {
 516     AvahiHwInterface *hw;
 517     AvahiInterface *i;
 518
 519     assert(m);
 520     assert(idx >= 0);
 521     assert(protocol != AVAHI_PROTO_UNSPEC);
 522
 523     if (!(hw = avahi_interface_monitor_get_hw_interface(m, idx)))
 524         return NULL;
 525
 526     for (i = hw->interfaces; i; i = i->by_hardware_next)
 527         if (i->protocol == protocol)
 528             return i;
 529
 530     return NULL;
 531 }
 532
 533 AvahiHwInterface* avahi_interface_monitor_get_hw_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
 534     assert(m);
 535     assert(idx > 0);
 536
 537     return avahi_hashmap_lookup(m->hashmap, &idx);
 538 }
 539
 540 AvahiInterfaceAddress* avahi_interface_monitor_get_address(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *raddr) {
 541     AvahiInterfaceAddress *ia;
 542
 543     assert(m);
 544     assert(i);
 545     assert(raddr);
 546
 547     for (ia = i->addresses; ia; ia = ia->address_next)
 548         if (avahi_address_cmp(&ia->address, raddr) == 0)
 549             return ia;
 550
 551     return NULL;
 552 }
 553
 554
 555 void avahi_interface_send_packet_unicast(AvahiInterface *i, AvahiDnsPacket *p, const AvahiAddress *a, uint16_t port) {
 556     assert(i);
 557     assert(p);
 558 /*     char t[AVAHI_ADDRESS_STR_MAX]; */
 559
 560     if (!avahi_interface_is_relevant(i))
 561         return;
 562
 563     assert(!a || a->proto == i->protocol);
 564
 565 /*     if (a) */
 566 /*         avahi_log_debug("unicast sending on '%s.%i' to %s:%u", i->hardware->name, i->protocol, avahi_address_snprint(t, sizeof(t), a), port); */
 567 /*     else */
 568 /*         avahi_log_debug("multicast sending on '%s.%i'", i->hardware->name, i->protocol); */
 569
 570     if (i->protocol == AVAHI_PROTO_INET && i->monitor->server->fd_ipv4 >= 0)
 571         avahi_send_dns_packet_ipv4(i->monitor->server->fd_ipv4, i->hardware->index, p, i->mcast_joined ? &i->local_mcast_address.data.ipv4 : NULL, a ? &a->data.ipv4 : NULL, port);
 572     else if (i->protocol == AVAHI_PROTO_INET6 && i->monitor->server->fd_ipv6 >= 0)
 573         avahi_send_dns_packet_ipv6(i->monitor->server->fd_ipv6, i->hardware->index, p, i->mcast_joined ? &i->local_mcast_address.data.ipv6 : NULL, a ? &a->data.ipv6 : NULL, port);
 574 }
 575
 576 void avahi_interface_send_packet(AvahiInterface *i, AvahiDnsPacket *p) {
 577     assert(i);
 578     assert(p);
 579
 580     avahi_interface_send_packet_unicast(i, p, NULL, 0);
 581 }
 582
 583 int avahi_interface_post_query(AvahiInterface *i, AvahiKey *key, int immediately, unsigned *ret_id) {
 584     assert(i);
 585     assert(key);
 586
 587     if (avahi_interface_is_relevant(i))
 588         return avahi_query_scheduler_post(i->query_scheduler, key, immediately, ret_id);
 589
 590     return 0;
 591 }
 592
 593 int avahi_interface_withraw_query(AvahiInterface *i, unsigned id) {
 594
 595     return avahi_query_scheduler_withdraw_by_id(i->query_scheduler, id);
 596 }
 597
 598 int avahi_interface_post_response(AvahiInterface *i, AvahiRecord *record, int flush_cache, const AvahiAddress *querier, int immediately) {
 599     assert(i);
 600     assert(record);
 601
 602     if (avahi_interface_is_relevant(i))
 603         return avahi_response_scheduler_post(i->response_scheduler, record, flush_cache, querier, immediately);
 604
 605     return 0;
 606 }
 607
 608 int avahi_interface_post_probe(AvahiInterface *i, AvahiRecord *record, int immediately) {
 609     assert(i);
 610     assert(record);
 611
 612     if (avahi_interface_is_relevant(i))
 613         return avahi_probe_scheduler_post(i->probe_scheduler, record, immediately);
 614
 615     return 0;
 616 }
 617
 618 int avahi_dump_caches(AvahiInterfaceMonitor *m, AvahiDumpCallback callback, void* userdata) {
 619     AvahiInterface *i;
 620     assert(m);
 621
 622     for (i = m->interfaces; i; i = i->interface_next) {
 623         if (avahi_interface_is_relevant(i)) {
 624             char ln[256];
 625             snprintf(ln, sizeof(ln), ";;; INTERFACE %s.%s ;;;", i->hardware->name, avahi_proto_to_string(i->protocol));
 626             callback(ln, userdata);
 627             if (avahi_cache_dump(i->cache, callback, userdata) < 0)
 628                 return -1;
 629         }
 630     }
 631
 632     return 0;
 633 }
 634
 635 int avahi_interface_is_relevant(AvahiInterface *i) {
 636     AvahiInterfaceAddress *a;
 637     int relevant_address;
 638
 639     assert(i);
 640
 641     relevant_address = 0;
 642
 643     for (a = i->addresses; a; a = a->address_next)
 644         if (avahi_interface_address_is_relevant(a)) {
 645             relevant_address = 1;
 646             break;
 647         }
 648
 649     return i->hardware->flags_ok && relevant_address;
 650 }
 651
 652 int avahi_interface_address_is_relevant(AvahiInterfaceAddress *a) {
 653     AvahiInterfaceAddress *b;
 654     assert(a);
 655
 656     /* Publish public IP addresses */
 657     if (a->global_scope)
 658         return 1;
 659     else {
 660
 661         /* Publish link local IP addresses if they are the only ones on the link */
 662         for (b = a->interface->addresses; b; b = b->address_next) {
 663             if (b == a)
 664                 continue;
 665
 666             if (b->global_scope)
 667                 return 0;
 668         }
 669
 670         return 1;
 671     }
 672
 673     return 0;
 674 }
 675
 676 int avahi_interface_match(AvahiInterface *i, AvahiIfIndex idx, AvahiProtocol protocol) {
 677     assert(i);
 678
 679     if (idx != AVAHI_IF_UNSPEC && idx != i->hardware->index)
 680         return 0;
 681
 682     if (protocol != AVAHI_PROTO_UNSPEC && protocol != i->protocol)
 683         return 0;
 684
 685     return 1;
 686 }
 687
 688 void avahi_interface_monitor_walk(AvahiInterfaceMonitor *m, AvahiIfIndex interface, AvahiProtocol protocol, AvahiInterfaceMonitorWalkCallback callback, void* userdata) {
 689     assert(m);
 690     assert(callback);
 691
 692     if (interface != AVAHI_IF_UNSPEC) {
 693         if (protocol != AVAHI_PROTO_UNSPEC) {
 694             AvahiInterface *i;
 695
 696             if ((i = avahi_interface_monitor_get_interface(m, interface, protocol)))
 697                 callback(m, i, userdata);
 698
 699         } else {
 700             AvahiHwInterface *hw;
 701             AvahiInterface *i;
 702
 703             if ((hw = avahi_interface_monitor_get_hw_interface(m, interface)))
 704                 for (i = hw->interfaces; i; i = i->by_hardware_next)
 705                     if (avahi_interface_match(i, interface, protocol))
 706                         callback(m, i, userdata);
 707         }
 708
 709     } else {
 710         AvahiInterface *i;
 711
 712         for (i = m->interfaces; i; i = i->interface_next)
 713             if (avahi_interface_match(i, interface, protocol))
 714                 callback(m, i, userdata);
 715     }
 716 }
 717
 718
 719 int avahi_address_is_local(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
 720     AvahiInterface *i;
 721     AvahiInterfaceAddress *ia;
 722     assert(m);
 723     assert(a);
 724
 725     for (i = m->interfaces; i; i = i->interface_next)
 726         for (ia = i->addresses; ia; ia = ia->address_next)
 727             if (avahi_address_cmp(a, &ia->address) == 0)
 728                 return 1;
 729
 730     return 0;
 731 }
 732
 733 int avahi_interface_address_on_link(AvahiInterface *i, const AvahiAddress *a) {
 734     AvahiInterfaceAddress *ia;
 735
 736     assert(i);
 737     assert(a);
 738
 739     if (a->proto != i->protocol)
 740         return 0;
 741
 742     for (ia = i->addresses; ia; ia = ia->address_next) {
 743
 744         if (a->proto == AVAHI_PROTO_INET) {
 745             uint32_t m;
 746
 747             m = ~(((uint32_t) -1) >> ia->prefix_len);
 748
 749             if ((ntohl(a->data.ipv4.address) & m) == (ntohl(ia->address.data.ipv4.address) & m))
 750                 return 1;
 751         } else {
 752             unsigned j;
 753             unsigned char pl;
 754             assert(a->proto == AVAHI_PROTO_INET6);
 755
 756             pl = ia->prefix_len;
 757
 758             for (j = 0; j < 16; j++) {
 759                 uint8_t m;
 760
 761                 if (pl == 0)
 762                     return 1;
 763
 764                 if (pl >= 8) {
 765                     m = 0xFF;
 766                     pl -= 8;
 767                 } else {
 768                     m = ~(0xFF >> pl);
 769                     pl = 0;
 770                 }
 771
 772                 if ((a->data.ipv6.address[j] & m) != (ia->address.data.ipv6.address[j] & m))
 773                     break;
 774             }
 775         }
 776     }
 777
 778     return 0;
 779 }
 780
 781 int avahi_interface_has_address(AvahiInterfaceMonitor *m, AvahiIfIndex iface, const AvahiAddress *a) {
 782     AvahiInterface *i;
 783     AvahiInterfaceAddress *j;
 784
 785     assert(m);
 786     assert(iface != AVAHI_IF_UNSPEC);
 787     assert(a);
 788
 789     if (!(i = avahi_interface_monitor_get_interface(m, iface, a->proto)))
 790         return 0;
 791
 792     for (j = i->addresses; j; j = j->address_next)
 793         if (avahi_address_cmp(a, &j->address) == 0)
 794             return 1;
 795
 796     return 0;
 797 }
 798
 799 AvahiIfIndex avahi_find_interface_for_address(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
 800     AvahiInterface *i;
 801     assert(m);
 802
 803     /* Some stupid OS don't support passing the interface index when a
 804      * packet is recieved. We have to work around that limitation by
 805      * looking for an interface that has the incoming address
 806      * attached. This is sometimes ambiguous, but we have to live with
 807      * it. */
 808
 809     for (i = m->interfaces; i; i = i->interface_next) {
 810         AvahiInterfaceAddress *ai;
 811
 812         if (i->protocol != a->proto)
 813             continue;
 814
 815         for (ai = i->addresses; ai; ai = ai->address_next)
 816             if (avahi_address_cmp(a, &ai->address) == 0)
 817                 return i->hardware->index;
 818     }
 819
 820     return AVAHI_IF_UNSPEC;
 821 }