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   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 <sys/types.h>
  31 #include <sys/socket.h>
  32 #include <netinet/in.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 (m->list_complete &&
  54         avahi_interface_address_is_relevant(a) &&
  55         avahi_interface_is_relevant(a->interface) &&
  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             AvahiProtocol p;
  71
  72             p = (a->interface->protocol == AVAHI_PROTO_INET && m->server->config.publish_a_on_ipv6) ||
  73                 (a->interface->protocol == AVAHI_PROTO_INET6 && m->server->config.publish_aaaa_on_ipv4) ? AVAHI_PROTO_UNSPEC : a->interface->protocol;
  74
  75             avahi_address_snprint(t, sizeof(t), &a->address);
  76             avahi_log_info("Registering new address record for %s on %s.%s.", t, a->interface->hardware->name, p == AVAHI_PROTO_UNSPEC ? "*" : avahi_proto_to_string(p));
  77
  78             if (avahi_server_add_address(m->server, a->entry_group, a->interface->hardware->index, p, 0, NULL, &a->address) < 0) {
  79                 avahi_log_warn(__FILE__": avahi_server_add_address() failed: %s", avahi_strerror(m->server->error));
  80                 avahi_s_entry_group_free(a->entry_group);
  81                 a->entry_group = NULL;
  82                 return;
  83             }
  84
  85             avahi_s_entry_group_commit(a->entry_group);
  86         }
  87     } else {
  88
  89         /* Clear the entry group */
  90
  91         if (a->entry_group && !avahi_s_entry_group_is_empty(a->entry_group)) {
  92             char t[AVAHI_ADDRESS_STR_MAX];
  93             avahi_address_snprint(t, sizeof(t), &a->address);
  94
  95             if (avahi_s_entry_group_get_state(a->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING &&
  96                 m->server->state == AVAHI_SERVER_REGISTERING)
  97                 avahi_server_decrease_host_rr_pending(m->server);
  98
  99             avahi_log_info("Withdrawing address record for %s on %s.", t, a->interface->hardware->name);
 100
 101             avahi_s_entry_group_reset(a->entry_group);
 102         }
 103     }
 104 }
 105
 106 void avahi_interface_update_rrs(AvahiInterface *i, int remove_rrs) {
 107     AvahiInterfaceAddress *a;
 108
 109     assert(i);
 110
 111     for (a = i->addresses; a; a = a->address_next)
 112         avahi_interface_address_update_rrs(a, remove_rrs);
 113 }
 114
 115 void avahi_hw_interface_update_rrs(AvahiHwInterface *hw, int remove_rrs) {
 116     AvahiInterface *i;
 117     AvahiInterfaceMonitor *m;
 118
 119     assert(hw);
 120     m = hw->monitor;
 121
 122     for (i = hw->interfaces; i; i = i->by_hardware_next)
 123         avahi_interface_update_rrs(i, remove_rrs);
 124
 125     if (m->list_complete &&
 126         !remove_rrs &&
 127         m->server->config.publish_workstation &&
 128         (m->server->state == AVAHI_SERVER_RUNNING)) {
 129
 130         if (!hw->entry_group)
 131             hw->entry_group = avahi_s_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
 132
 133         if (!hw->entry_group)
 134             return; /* OOM */
 135
 136         if (avahi_s_entry_group_is_empty(hw->entry_group)) {
 137             char name[AVAHI_LABEL_MAX], mac[256];
 138
 139             avahi_format_mac_address(mac, sizeof(mac), hw->mac_address, hw->mac_address_size);
 140             snprintf(name, sizeof(name), "%s [%s]", m->server->host_name, mac);
 141
 142             if (avahi_server_add_service(m->server, hw->entry_group, hw->index, AVAHI_PROTO_UNSPEC, 0, name, "_workstation._tcp", NULL, NULL, 9, NULL) < 0) {
 143                 avahi_log_warn(__FILE__": avahi_server_add_service() failed: %s", avahi_strerror(m->server->error));
 144                 avahi_s_entry_group_free(hw->entry_group);
 145                 hw->entry_group = NULL;
 146             } else
 147                 avahi_s_entry_group_commit(hw->entry_group);
 148         }
 149
 150     } else {
 151
 152         if (hw->entry_group && !avahi_s_entry_group_is_empty(hw->entry_group)) {
 153
 154             if (avahi_s_entry_group_get_state(hw->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING)
 155                 avahi_server_decrease_host_rr_pending(m->server);
 156
 157             avahi_s_entry_group_reset(hw->entry_group);
 158         }
 159     }
 160 }
 161
 162 void avahi_interface_monitor_update_rrs(AvahiInterfaceMonitor *m, int remove_rrs) {
 163     AvahiHwInterface *hw;
 164
 165     assert(m);
 166
 167     for (hw = m->hw_interfaces; hw; hw = hw->hardware_next)
 168         avahi_hw_interface_update_rrs(hw, remove_rrs);
 169 }
 170
 171 static int interface_mdns_mcast_join(AvahiInterface *i, int join) {
 172     char at[AVAHI_ADDRESS_STR_MAX];
 173     int r;
 174     assert(i);
 175
 176     if (!!join  == !!i->mcast_joined)
 177         return 0;
 178
 179     if ((i->protocol == AVAHI_PROTO_INET6 && i->monitor->server->fd_ipv6 < 0) ||
 180         (i->protocol == AVAHI_PROTO_INET && i->monitor->server->fd_ipv4 < 0))
 181         return -1;
 182
 183     if (join) {
 184         AvahiInterfaceAddress *a;
 185
 186         /* Look if there's an address with global scope */
 187         for (a = i->addresses; a; a = a->address_next)
 188             if (a->global_scope)
 189                 break;
 190
 191         /* No address with a global scope has been found, so let's use
 192          * any. */
 193         if (!a)
 194             a = i->addresses;
 195
 196         /* Hmm, there is no address available. */
 197         if (!a)
 198             return -1;
 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         r = 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         r = avahi_mdns_mcast_join_ipv4(i->monitor->server->fd_ipv4, &i->local_mcast_address.data.ipv4, i->hardware->index, join);
 215     }
 216
 217     if (r < 0)
 218         i->mcast_joined = 0;
 219     else
 220         i->mcast_joined = join;
 221
 222     return 0;
 223 }
 224
 225 static int interface_mdns_mcast_rejoin(AvahiInterface *i) {
 226     AvahiInterfaceAddress *a, *usable = NULL, *found = NULL;
 227     assert(i);
 228
 229     if (!i->mcast_joined)
 230         return 0;
 231
 232     /* Check whether old address we joined with is still available. If
 233      * not, rejoin using an other address. */
 234
 235     for (a = i->addresses; a; a = a->address_next) {
 236         if (a->global_scope && !usable)
 237             usable = a;
 238
 239         if (avahi_address_cmp(&a->address, &i->local_mcast_address) == 0) {
 240
 241             if (a->global_scope)
 242                 /* No action necessary: the address still exists and
 243                  * has global scope. */
 244                 return 0;
 245
 246             found = a;
 247         }
 248     }
 249
 250     if (found && !usable)
 251         /* No action necessary: the address still exists and no better one has been found */
 252         return 0;
 253
 254     interface_mdns_mcast_join(i, 0);
 255     return interface_mdns_mcast_join(i, 1);
 256 }
 257
 258 void avahi_interface_address_free(AvahiInterfaceAddress *a) {
 259     assert(a);
 260     assert(a->interface);
 261
 262     avahi_interface_address_update_rrs(a, 1);
 263     AVAHI_LLIST_REMOVE(AvahiInterfaceAddress, address, a->interface->addresses, a);
 264
 265     if (a->entry_group)
 266         avahi_s_entry_group_free(a->entry_group);
 267
 268     interface_mdns_mcast_rejoin(a->interface);
 269
 270     avahi_free(a);
 271 }
 272
 273 void avahi_interface_free(AvahiInterface *i, int send_goodbye) {
 274     assert(i);
 275
 276     /* Handle goodbyes and remove announcers */
 277     avahi_goodbye_interface(i->monitor->server, i, send_goodbye, 1);
 278     avahi_response_scheduler_force(i->response_scheduler);
 279     assert(!i->announcers);
 280
 281     if (i->mcast_joined)
 282         interface_mdns_mcast_join(i, 0);
 283
 284     /* Remove queriers */
 285     avahi_querier_free_all(i);
 286     avahi_hashmap_free(i->queriers_by_key);
 287
 288     /* Remove local RRs */
 289     avahi_interface_update_rrs(i, 1);
 290
 291     while (i->addresses)
 292         avahi_interface_address_free(i->addresses);
 293
 294     avahi_response_scheduler_free(i->response_scheduler);
 295     avahi_query_scheduler_free(i->query_scheduler);
 296     avahi_probe_scheduler_free(i->probe_scheduler);
 297     avahi_cache_free(i->cache);
 298
 299     AVAHI_LLIST_REMOVE(AvahiInterface, interface, i->monitor->interfaces, i);
 300     AVAHI_LLIST_REMOVE(AvahiInterface, by_hardware, i->hardware->interfaces, i);
 301
 302     avahi_free(i);
 303 }
 304
 305 void avahi_hw_interface_free(AvahiHwInterface *hw, int send_goodbye) {
 306     assert(hw);
 307
 308     avahi_hw_interface_update_rrs(hw, 1);
 309
 310     while (hw->interfaces)
 311         avahi_interface_free(hw->interfaces, send_goodbye);
 312
 313     if (hw->entry_group)
 314         avahi_s_entry_group_free(hw->entry_group);
 315
 316     AVAHI_LLIST_REMOVE(AvahiHwInterface, hardware, hw->monitor->hw_interfaces, hw);
 317     avahi_hashmap_remove(hw->monitor->hashmap, &hw->index);
 318
 319     avahi_free(hw->name);
 320     avahi_free(hw);
 321 }
 322
 323 AvahiInterface* avahi_interface_new(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, AvahiProtocol protocol) {
 324     AvahiInterface *i;
 325
 326     assert(m);
 327     assert(hw);
 328     assert(AVAHI_PROTO_VALID(protocol));
 329
 330     if (!(i = avahi_new(AvahiInterface, 1)))
 331         goto fail; /* OOM */
 332
 333     i->monitor = m;
 334     i->hardware = hw;
 335     i->protocol = protocol;
 336     i->announcing = 0;
 337     i->mcast_joined = 0;
 338
 339     AVAHI_LLIST_HEAD_INIT(AvahiInterfaceAddress, i->addresses);
 340     AVAHI_LLIST_HEAD_INIT(AvahiAnnouncer, i->announcers);
 341
 342     AVAHI_LLIST_HEAD_INIT(AvahiQuerier, i->queriers);
 343     i->queriers_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL);
 344
 345     i->cache = avahi_cache_new(m->server, i);
 346     i->response_scheduler = avahi_response_scheduler_new(i);
 347     i->query_scheduler = avahi_query_scheduler_new(i);
 348     i->probe_scheduler = avahi_probe_scheduler_new(i);
 349
 350     if (!i->cache || !i->response_scheduler || !i->query_scheduler || !i->probe_scheduler)
 351         goto fail; /* OOM */
 352
 353     AVAHI_LLIST_PREPEND(AvahiInterface, by_hardware, hw->interfaces, i);
 354     AVAHI_LLIST_PREPEND(AvahiInterface, interface, m->interfaces, i);
 355
 356     return i;
 357
 358 fail:
 359
 360     if (i) {
 361         if (i->cache)
 362             avahi_cache_free(i->cache);
 363         if (i->response_scheduler)
 364             avahi_response_scheduler_free(i->response_scheduler);
 365         if (i->query_scheduler)
 366             avahi_query_scheduler_free(i->query_scheduler);
 367         if (i->probe_scheduler)
 368             avahi_probe_scheduler_free(i->probe_scheduler);
 369     }
 370
 371     return NULL;
 372 }
 373
 374 AvahiHwInterface *avahi_hw_interface_new(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
 375     AvahiHwInterface *hw;
 376
 377     assert(m);
 378     assert(AVAHI_IF_VALID(idx));
 379
 380     if  (!(hw = avahi_new(AvahiHwInterface, 1)))
 381         return NULL;
 382
 383     hw->monitor = m;
 384     hw->name = NULL;
 385     hw->flags_ok = 0;
 386     hw->mtu = 1500;
 387     hw->index = idx;
 388     hw->mac_address_size = 0;
 389     hw->entry_group = NULL;
 390
 391     AVAHI_LLIST_HEAD_INIT(AvahiInterface, hw->interfaces);
 392     AVAHI_LLIST_PREPEND(AvahiHwInterface, hardware, m->hw_interfaces, hw);
 393
 394     avahi_hashmap_insert(m->hashmap, &hw->index, hw);
 395
 396     if (m->server->fd_ipv4 >= 0 || m->server->config.publish_a_on_ipv6)
 397         avahi_interface_new(m, hw, AVAHI_PROTO_INET);
 398     if (m->server->fd_ipv6 >= 0 || m->server->config.publish_aaaa_on_ipv4)
 399         avahi_interface_new(m, hw, AVAHI_PROTO_INET6);
 400
 401     return hw;
 402 }
 403
 404 AvahiInterfaceAddress *avahi_interface_address_new(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *addr, unsigned prefix_len) {
 405     AvahiInterfaceAddress *a;
 406
 407     assert(m);
 408     assert(i);
 409
 410     if (!(a = avahi_new(AvahiInterfaceAddress, 1)))
 411         return NULL;
 412
 413     a->interface = i;
 414     a->monitor = m;
 415     a->address = *addr;
 416     a->prefix_len = prefix_len;
 417     a->global_scope = 0;
 418     a->entry_group = NULL;
 419
 420     AVAHI_LLIST_PREPEND(AvahiInterfaceAddress, address, i->addresses, a);
 421
 422     return a;
 423 }
 424
 425 void avahi_interface_check_relevant(AvahiInterface *i) {
 426     int b;
 427     AvahiInterfaceMonitor *m;
 428
 429     assert(i);
 430     m = i->monitor;
 431
 432     b = avahi_interface_is_relevant(i);
 433
 434     if (m->list_complete && b && !i->announcing) {
 435         interface_mdns_mcast_join(i, 1);
 436
 437         if (i->mcast_joined) {
 438             avahi_log_info("New relevant interface %s.%s for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 439
 440             i->announcing = 1;
 441             avahi_announce_interface(m->server, i);
 442             avahi_multicast_lookup_engine_new_interface(m->server->multicast_lookup_engine, i);
 443         }
 444
 445     } else if (!b && i->announcing) {
 446         avahi_log_info("Interface %s.%s no longer relevant for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 447
 448         interface_mdns_mcast_join(i, 0);
 449
 450         avahi_goodbye_interface(m->server, i, 0, 1);
 451         avahi_querier_free_all(i);
 452
 453         avahi_response_scheduler_clear(i->response_scheduler);
 454         avahi_query_scheduler_clear(i->query_scheduler);
 455         avahi_probe_scheduler_clear(i->probe_scheduler);
 456         avahi_cache_flush(i->cache);
 457
 458         i->announcing = 0;
 459
 460     } else
 461         interface_mdns_mcast_rejoin(i);
 462 }
 463
 464 void avahi_hw_interface_check_relevant(AvahiHwInterface *hw) {
 465     AvahiInterface *i;
 466
 467     assert(hw);
 468
 469     for (i = hw->interfaces; i; i = i->by_hardware_next)
 470         avahi_interface_check_relevant(i);
 471 }
 472
 473 void avahi_interface_monitor_check_relevant(AvahiInterfaceMonitor *m) {
 474     AvahiInterface *i;
 475
 476     assert(m);
 477
 478     for (i = m->interfaces; i; i = i->interface_next)
 479         avahi_interface_check_relevant(i);
 480 }
 481
 482 AvahiInterfaceMonitor *avahi_interface_monitor_new(AvahiServer *s) {
 483     AvahiInterfaceMonitor *m = NULL;
 484
 485     if (!(m = avahi_new0(AvahiInterfaceMonitor, 1)))
 486         return NULL; /* OOM */
 487
 488     m->server = s;
 489     m->list_complete = 0;
 490     m->hashmap = avahi_hashmap_new(avahi_int_hash, avahi_int_equal, NULL, NULL);
 491
 492     AVAHI_LLIST_HEAD_INIT(AvahiInterface, m->interfaces);
 493     AVAHI_LLIST_HEAD_INIT(AvahiHwInterface, m->hw_interfaces);
 494
 495     if (avahi_interface_monitor_init_osdep(m) < 0)
 496         goto fail;
 497
 498     return m;
 499
 500 fail:
 501     avahi_interface_monitor_free(m);
 502     return NULL;
 503 }
 504
 505 void avahi_interface_monitor_free(AvahiInterfaceMonitor *m) {
 506     assert(m);
 507
 508     while (m->hw_interfaces)
 509         avahi_hw_interface_free(m->hw_interfaces, 1);
 510
 511     assert(!m->interfaces);
 512
 513     avahi_interface_monitor_free_osdep(m);
 514
 515     if (m->hashmap)
 516         avahi_hashmap_free(m->hashmap);
 517
 518     avahi_free(m);
 519 }
 520
 521
 522 AvahiInterface* avahi_interface_monitor_get_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx, AvahiProtocol protocol) {
 523     AvahiHwInterface *hw;
 524     AvahiInterface *i;
 525
 526     assert(m);
 527     assert(idx >= 0);
 528     assert(protocol != AVAHI_PROTO_UNSPEC);
 529
 530     if (!(hw = avahi_interface_monitor_get_hw_interface(m, idx)))
 531         return NULL;
 532
 533     for (i = hw->interfaces; i; i = i->by_hardware_next)
 534         if (i->protocol == protocol)
 535             return i;
 536
 537     return NULL;
 538 }
 539
 540 AvahiHwInterface* avahi_interface_monitor_get_hw_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
 541     assert(m);
 542     assert(idx >= 0);
 543
 544     return avahi_hashmap_lookup(m->hashmap, &idx);
 545 }
 546
 547 AvahiInterfaceAddress* avahi_interface_monitor_get_address(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *raddr) {
 548     AvahiInterfaceAddress *ia;
 549
 550     assert(m);
 551     assert(i);
 552     assert(raddr);
 553
 554     for (ia = i->addresses; ia; ia = ia->address_next)
 555         if (avahi_address_cmp(&ia->address, raddr) == 0)
 556             return ia;
 557
 558     return NULL;
 559 }
 560
 561 void avahi_interface_send_packet_unicast(AvahiInterface *i, AvahiDnsPacket *p, const AvahiAddress *a, uint16_t port) {
 562     assert(i);
 563     assert(p);
 564
 565     if (!i->announcing)
 566         return;
 567
 568     assert(!a || a->proto == 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 (!i->announcing)
 588         return 0;
 589
 590     return avahi_query_scheduler_post(i->query_scheduler, key, immediately, ret_id);
 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 (!i->announcing)
 603         return 0;
 604
 605     return avahi_response_scheduler_post(i->response_scheduler, record, flush_cache, querier, immediately);
 606 }
 607
 608 int avahi_interface_post_probe(AvahiInterface *i, AvahiRecord *record, int immediately) {
 609     assert(i);
 610     assert(record);
 611
 612     if (!i->announcing)
 613         return 0;
 614
 615     return avahi_probe_scheduler_post(i->probe_scheduler, record, immediately);
 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
 638     assert(i);
 639
 640     if (!i->hardware->flags_ok)
 641         return 0;
 642
 643     for (a = i->addresses; a; a = a->address_next)
 644         if (avahi_interface_address_is_relevant(a))
 645             return 1;
 646
 647     return 0;
 648 }
 649
 650 int avahi_interface_address_is_relevant(AvahiInterfaceAddress *a) {
 651     AvahiInterfaceAddress *b;
 652     assert(a);
 653
 654     /* Publish public IP addresses */
 655     if (a->global_scope)
 656         return 1;
 657     else {
 658
 659         /* Publish link local IP addresses if they are the only ones on the link */
 660         for (b = a->interface->addresses; b; b = b->address_next) {
 661             if (b == a)
 662                 continue;
 663
 664             if (b->global_scope)
 665                 return 0;
 666         }
 667
 668         return 1;
 669     }
 670
 671     return 0;
 672 }
 673
 674 int avahi_interface_match(AvahiInterface *i, AvahiIfIndex idx, AvahiProtocol protocol) {
 675     assert(i);
 676
 677     if (idx != AVAHI_IF_UNSPEC && idx != i->hardware->index)
 678         return 0;
 679
 680     if (protocol != AVAHI_PROTO_UNSPEC && protocol != i->protocol)
 681         return 0;
 682
 683     return 1;
 684 }
 685
 686 void avahi_interface_monitor_walk(AvahiInterfaceMonitor *m, AvahiIfIndex interface, AvahiProtocol protocol, AvahiInterfaceMonitorWalkCallback callback, void* userdata) {
 687     assert(m);
 688     assert(callback);
 689
 690     if (interface != AVAHI_IF_UNSPEC) {
 691         if (protocol != AVAHI_PROTO_UNSPEC) {
 692             AvahiInterface *i;
 693
 694             if ((i = avahi_interface_monitor_get_interface(m, interface, protocol)))
 695                 callback(m, i, userdata);
 696
 697         } else {
 698             AvahiHwInterface *hw;
 699             AvahiInterface *i;
 700
 701             if ((hw = avahi_interface_monitor_get_hw_interface(m, interface)))
 702                 for (i = hw->interfaces; i; i = i->by_hardware_next)
 703                     if (avahi_interface_match(i, interface, protocol))
 704                         callback(m, i, userdata);
 705         }
 706
 707     } else {
 708         AvahiInterface *i;
 709
 710         for (i = m->interfaces; i; i = i->interface_next)
 711             if (avahi_interface_match(i, interface, protocol))
 712                 callback(m, i, userdata);
 713     }
 714 }
 715
 716
 717 int avahi_address_is_local(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
 718     AvahiInterface *i;
 719     AvahiInterfaceAddress *ia;
 720     assert(m);
 721     assert(a);
 722
 723     for (i = m->interfaces; i; i = i->interface_next)
 724         for (ia = i->addresses; ia; ia = ia->address_next)
 725             if (avahi_address_cmp(a, &ia->address) == 0)
 726                 return 1;
 727
 728     return 0;
 729 }
 730
 731 int avahi_interface_address_on_link(AvahiInterface *i, const AvahiAddress *a) {
 732     AvahiInterfaceAddress *ia;
 733
 734     assert(i);
 735     assert(a);
 736
 737     if (a->proto != i->protocol)
 738         return 0;
 739
 740     for (ia = i->addresses; ia; ia = ia->address_next) {
 741
 742         if (a->proto == AVAHI_PROTO_INET) {
 743             uint32_t m;
 744
 745             m = ~(((uint32_t) -1) >> ia->prefix_len);
 746
 747             if ((ntohl(a->data.ipv4.address) & m) == (ntohl(ia->address.data.ipv4.address) & m))
 748                 return 1;
 749         } else {
 750             unsigned j;
 751             unsigned char pl;
 752             assert(a->proto == AVAHI_PROTO_INET6);
 753
 754             pl = ia->prefix_len;
 755
 756             for (j = 0; j < 16; j++) {
 757                 uint8_t m;
 758
 759                 if (pl == 0)
 760                     return 1;
 761
 762                 if (pl >= 8) {
 763                     m = 0xFF;
 764                     pl -= 8;
 765                 } else {
 766                     m = ~(0xFF >> pl);
 767                     pl = 0;
 768                 }
 769
 770                 if ((a->data.ipv6.address[j] & m) != (ia->address.data.ipv6.address[j] & m))
 771                     break;
 772             }
 773         }
 774     }
 775
 776     return 0;
 777 }
 778
 779 int avahi_interface_has_address(AvahiInterfaceMonitor *m, AvahiIfIndex iface, const AvahiAddress *a) {
 780     AvahiInterface *i;
 781     AvahiInterfaceAddress *j;
 782
 783     assert(m);
 784     assert(iface != AVAHI_IF_UNSPEC);
 785     assert(a);
 786
 787     if (!(i = avahi_interface_monitor_get_interface(m, iface, a->proto)))
 788         return 0;
 789
 790     for (j = i->addresses; j; j = j->address_next)
 791         if (avahi_address_cmp(a, &j->address) == 0)
 792             return 1;
 793
 794     return 0;
 795 }
 796
 797 AvahiIfIndex avahi_find_interface_for_address(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
 798     AvahiInterface *i;
 799     assert(m);
 800
 801     /* Some stupid OS don't support passing the interface index when a
 802      * packet is received. We have to work around that limitation by
 803      * looking for an interface that has the incoming address
 804      * attached. This is sometimes ambiguous, but we have to live with
 805      * it. */
 806
 807     for (i = m->interfaces; i; i = i->interface_next) {
 808         AvahiInterfaceAddress *ai;
 809
 810         if (i->protocol != a->proto)
 811             continue;
 812
 813         for (ai = i->addresses; ai; ai = ai->address_next)
 814             if (avahi_address_cmp(a, &ai->address) == 0)
 815                 return i->hardware->index;
 816     }
 817
 818     return AVAHI_IF_UNSPEC;
 819 }