git.meshlink.io Git - catta/blob - avahi-core/iface.c

   1 /***
   2   This file is part of avahi.
   3
   4   avahi is free software; you can redistribute it and/or modify it
   5   under the terms of the GNU Lesser General Public License as
   6   published by the Free Software Foundation; either version 2.1 of the
   7   License, or (at your option) any later version.
   8
   9   avahi is distributed in the hope that it will be useful, but WITHOUT
  10   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  12   Public License for more details.
  13
  14   You should have received a copy of the GNU Lesser General Public
  15   License along with avahi; if not, write to the Free Software
  16   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  17   USA.
  18 ***/
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31
  32 #include <avahi-common/error.h>
  33 #include <avahi-common/malloc.h>
  34 #include <avahi-common/domain.h>
  35
  36 #include "iface.h"
  37 #include "dns.h"
  38 #include "socket.h"
  39 #include "announce.h"
  40 #include "util.h"
  41 #include "log.h"
  42 #include "multicast-lookup.h"
  43 #include "querier.h"
  44
  45 void avahi_interface_address_update_rrs(AvahiInterfaceAddress *a, int remove_rrs) {
  46     AvahiInterfaceMonitor *m;
  47
  48     assert(a);
  49     m = a->monitor;
  50
  51     if (m->list_complete &&
  52         avahi_interface_address_is_relevant(a) &&
  53         avahi_interface_is_relevant(a->interface) &&
  54         !remove_rrs &&
  55         m->server->config.publish_addresses &&
  56         (m->server->state == AVAHI_SERVER_RUNNING ||
  57         m->server->state == AVAHI_SERVER_REGISTERING)) {
  58
  59         /* Fill the entry group */
  60         if (!a->entry_group)
  61             a->entry_group = avahi_s_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
  62
  63         if (!a->entry_group) /* OOM */
  64             return;
  65
  66         if (avahi_s_entry_group_is_empty(a->entry_group)) {
  67             char t[AVAHI_ADDRESS_STR_MAX];
  68             AvahiProtocol p;
  69
  70             p = (a->interface->protocol == AVAHI_PROTO_INET && m->server->config.publish_a_on_ipv6) ||
  71                 (a->interface->protocol == AVAHI_PROTO_INET6 && m->server->config.publish_aaaa_on_ipv4) ? AVAHI_PROTO_UNSPEC : a->interface->protocol;
  72
  73             avahi_address_snprint(t, sizeof(t), &a->address);
  74             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));
  75
  76             if (avahi_server_add_address(m->server, a->entry_group, a->interface->hardware->index, p, 0, NULL, &a->address) < 0) {
  77                 avahi_log_warn(__FILE__": avahi_server_add_address() failed: %s", avahi_strerror(m->server->error));
  78                 avahi_s_entry_group_free(a->entry_group);
  79                 a->entry_group = NULL;
  80                 return;
  81             }
  82
  83             avahi_s_entry_group_commit(a->entry_group);
  84         }
  85     } else {
  86
  87         /* Clear the entry group */
  88
  89         if (a->entry_group && !avahi_s_entry_group_is_empty(a->entry_group)) {
  90             char t[AVAHI_ADDRESS_STR_MAX];
  91             avahi_address_snprint(t, sizeof(t), &a->address);
  92
  93             if (avahi_s_entry_group_get_state(a->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING &&
  94                 m->server->state == AVAHI_SERVER_REGISTERING)
  95                 avahi_server_decrease_host_rr_pending(m->server);
  96
  97             avahi_log_info("Withdrawing address record for %s on %s.", t, a->interface->hardware->name);
  98
  99             avahi_s_entry_group_reset(a->entry_group);
 100         }
 101     }
 102 }
 103
 104 void avahi_interface_update_rrs(AvahiInterface *i, int remove_rrs) {
 105     AvahiInterfaceAddress *a;
 106
 107     assert(i);
 108
 109     for (a = i->addresses; a; a = a->address_next)
 110         avahi_interface_address_update_rrs(a, remove_rrs);
 111 }
 112
 113 void avahi_hw_interface_update_rrs(AvahiHwInterface *hw, int remove_rrs) {
 114     AvahiInterface *i;
 115     AvahiInterfaceMonitor *m;
 116
 117     assert(hw);
 118     m = hw->monitor;
 119
 120     for (i = hw->interfaces; i; i = i->by_hardware_next)
 121         avahi_interface_update_rrs(i, remove_rrs);
 122
 123     if (m->list_complete &&
 124         !remove_rrs &&
 125         m->server->config.publish_workstation &&
 126         (m->server->state == AVAHI_SERVER_RUNNING)) {
 127
 128         if (!hw->entry_group)
 129             hw->entry_group = avahi_s_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
 130
 131         if (!hw->entry_group)
 132             return; /* OOM */
 133
 134         if (avahi_s_entry_group_is_empty(hw->entry_group)) {
 135             char name[AVAHI_LABEL_MAX], mac[256];
 136
 137             avahi_format_mac_address(mac, sizeof(mac), hw->mac_address, hw->mac_address_size);
 138             snprintf(name, sizeof(name), "%s [%s]", m->server->host_name, mac);
 139
 140             if (avahi_server_add_service(m->server, hw->entry_group, hw->index, AVAHI_PROTO_UNSPEC, 0, name, "_workstation._tcp", NULL, NULL, 9, NULL) < 0) {
 141                 avahi_log_warn(__FILE__": avahi_server_add_service() failed: %s", avahi_strerror(m->server->error));
 142                 avahi_s_entry_group_free(hw->entry_group);
 143                 hw->entry_group = NULL;
 144             } else
 145                 avahi_s_entry_group_commit(hw->entry_group);
 146         }
 147
 148     } else {
 149
 150         if (hw->entry_group && !avahi_s_entry_group_is_empty(hw->entry_group)) {
 151
 152             if (avahi_s_entry_group_get_state(hw->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING)
 153                 avahi_server_decrease_host_rr_pending(m->server);
 154
 155             avahi_s_entry_group_reset(hw->entry_group);
 156         }
 157     }
 158 }
 159
 160 void avahi_interface_monitor_update_rrs(AvahiInterfaceMonitor *m, int remove_rrs) {
 161     AvahiHwInterface *hw;
 162
 163     assert(m);
 164
 165     for (hw = m->hw_interfaces; hw; hw = hw->hardware_next)
 166         avahi_hw_interface_update_rrs(hw, remove_rrs);
 167 }
 168
 169 static int interface_mdns_mcast_join(AvahiInterface *i, int join) {
 170     char at[AVAHI_ADDRESS_STR_MAX];
 171     int r;
 172     assert(i);
 173
 174     if (!!join  == !!i->mcast_joined)
 175         return 0;
 176
 177     if ((i->protocol == AVAHI_PROTO_INET6 && i->monitor->server->fd_ipv6 < 0) ||
 178         (i->protocol == AVAHI_PROTO_INET && i->monitor->server->fd_ipv4 < 0))
 179         return -1;
 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             return -1;
 197
 198         i->local_mcast_address = a->address;
 199     }
 200
 201     avahi_log_info("%s mDNS multicast group on interface %s.%s with address %s.",
 202                    join ? "Joining" : "Leaving",
 203                    i->hardware->name,
 204                    avahi_proto_to_string(i->protocol),
 205                    avahi_address_snprint(at, sizeof(at), &i->local_mcast_address));
 206
 207     if (i->protocol == AVAHI_PROTO_INET6)
 208         r = avahi_mdns_mcast_join_ipv6(i->monitor->server->fd_ipv6, &i->local_mcast_address.data.ipv6, i->hardware->index, join);
 209     else {
 210         assert(i->protocol == AVAHI_PROTO_INET);
 211
 212         r = avahi_mdns_mcast_join_ipv4(i->monitor->server->fd_ipv4, &i->local_mcast_address.data.ipv4, i->hardware->index, join);
 213     }
 214
 215     if (r < 0)
 216         i->mcast_joined = 0;
 217     else
 218         i->mcast_joined = join;
 219
 220     return 0;
 221 }
 222
 223 static int interface_mdns_mcast_rejoin(AvahiInterface *i) {
 224     AvahiInterfaceAddress *a, *usable = NULL, *found = NULL;
 225     assert(i);
 226
 227     if (!i->mcast_joined)
 228         return 0;
 229
 230     /* Check whether old address we joined with is still available. If
 231      * not, rejoin using an other address. */
 232
 233     for (a = i->addresses; a; a = a->address_next) {
 234         if (a->global_scope && !usable)
 235             usable = a;
 236
 237         if (avahi_address_cmp(&a->address, &i->local_mcast_address) == 0) {
 238
 239             if (a->global_scope)
 240                 /* No action necessary: the address still exists and
 241                  * has global scope. */
 242                 return 0;
 243
 244             found = a;
 245         }
 246     }
 247
 248     if (found && !usable)
 249         /* No action necessary: the address still exists and no better one has been found */
 250         return 0;
 251
 252     interface_mdns_mcast_join(i, 0);
 253     return interface_mdns_mcast_join(i, 1);
 254 }
 255
 256 void avahi_interface_address_free(AvahiInterfaceAddress *a) {
 257     assert(a);
 258     assert(a->interface);
 259
 260     avahi_interface_address_update_rrs(a, 1);
 261     AVAHI_LLIST_REMOVE(AvahiInterfaceAddress, address, a->interface->addresses, a);
 262
 263     if (a->entry_group)
 264         avahi_s_entry_group_free(a->entry_group);
 265
 266     interface_mdns_mcast_rejoin(a->interface);
 267
 268     avahi_free(a);
 269 }
 270
 271 void avahi_interface_free(AvahiInterface *i, int send_goodbye) {
 272     assert(i);
 273
 274     /* Handle goodbyes and remove announcers */
 275     avahi_goodbye_interface(i->monitor->server, i, send_goodbye, 1);
 276     avahi_response_scheduler_force(i->response_scheduler);
 277     assert(!i->announcers);
 278
 279     if (i->mcast_joined)
 280         interface_mdns_mcast_join(i, 0);
 281
 282     /* Remove queriers */
 283     avahi_querier_free_all(i);
 284     avahi_hashmap_free(i->queriers_by_key);
 285
 286     /* Remove local RRs */
 287     avahi_interface_update_rrs(i, 1);
 288
 289     while (i->addresses)
 290         avahi_interface_address_free(i->addresses);
 291
 292     avahi_response_scheduler_free(i->response_scheduler);
 293     avahi_query_scheduler_free(i->query_scheduler);
 294     avahi_probe_scheduler_free(i->probe_scheduler);
 295     avahi_cache_free(i->cache);
 296
 297     AVAHI_LLIST_REMOVE(AvahiInterface, interface, i->monitor->interfaces, i);
 298     AVAHI_LLIST_REMOVE(AvahiInterface, by_hardware, i->hardware->interfaces, i);
 299
 300     avahi_free(i);
 301 }
 302
 303 void avahi_hw_interface_free(AvahiHwInterface *hw, int send_goodbye) {
 304     assert(hw);
 305
 306     avahi_hw_interface_update_rrs(hw, 1);
 307
 308     while (hw->interfaces)
 309         avahi_interface_free(hw->interfaces, send_goodbye);
 310
 311     if (hw->entry_group)
 312         avahi_s_entry_group_free(hw->entry_group);
 313
 314     AVAHI_LLIST_REMOVE(AvahiHwInterface, hardware, hw->monitor->hw_interfaces, hw);
 315     avahi_hashmap_remove(hw->monitor->hashmap, &hw->index);
 316
 317     avahi_free(hw->name);
 318     avahi_free(hw);
 319 }
 320
 321 AvahiInterface* avahi_interface_new(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, AvahiProtocol protocol) {
 322     AvahiInterface *i;
 323
 324     assert(m);
 325     assert(hw);
 326     assert(AVAHI_PROTO_VALID(protocol));
 327
 328     if (!(i = avahi_new(AvahiInterface, 1)))
 329         goto fail; /* OOM */
 330
 331     i->monitor = m;
 332     i->hardware = hw;
 333     i->protocol = protocol;
 334     i->announcing = 0;
 335     i->mcast_joined = 0;
 336
 337     AVAHI_LLIST_HEAD_INIT(AvahiInterfaceAddress, i->addresses);
 338     AVAHI_LLIST_HEAD_INIT(AvahiAnnouncer, i->announcers);
 339
 340     AVAHI_LLIST_HEAD_INIT(AvahiQuerier, i->queriers);
 341     i->queriers_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL);
 342
 343     i->cache = avahi_cache_new(m->server, i);
 344     i->response_scheduler = avahi_response_scheduler_new(i);
 345     i->query_scheduler = avahi_query_scheduler_new(i);
 346     i->probe_scheduler = avahi_probe_scheduler_new(i);
 347
 348     if (!i->cache || !i->response_scheduler || !i->query_scheduler || !i->probe_scheduler)
 349         goto fail; /* OOM */
 350
 351     AVAHI_LLIST_PREPEND(AvahiInterface, by_hardware, hw->interfaces, i);
 352     AVAHI_LLIST_PREPEND(AvahiInterface, interface, m->interfaces, i);
 353
 354     return i;
 355
 356 fail:
 357
 358     if (i) {
 359         if (i->cache)
 360             avahi_cache_free(i->cache);
 361         if (i->response_scheduler)
 362             avahi_response_scheduler_free(i->response_scheduler);
 363         if (i->query_scheduler)
 364             avahi_query_scheduler_free(i->query_scheduler);
 365         if (i->probe_scheduler)
 366             avahi_probe_scheduler_free(i->probe_scheduler);
 367     }
 368
 369     return NULL;
 370 }
 371
 372 AvahiHwInterface *avahi_hw_interface_new(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
 373     AvahiHwInterface *hw;
 374
 375     assert(m);
 376     assert(AVAHI_IF_VALID(idx));
 377
 378     if  (!(hw = avahi_new(AvahiHwInterface, 1)))
 379         return NULL;
 380
 381     hw->monitor = m;
 382     hw->name = NULL;
 383     hw->flags_ok = 0;
 384     hw->mtu = 1500;
 385     hw->index = idx;
 386     hw->mac_address_size = 0;
 387     hw->entry_group = NULL;
 388
 389     AVAHI_LLIST_HEAD_INIT(AvahiInterface, hw->interfaces);
 390     AVAHI_LLIST_PREPEND(AvahiHwInterface, hardware, m->hw_interfaces, hw);
 391
 392     avahi_hashmap_insert(m->hashmap, &hw->index, hw);
 393
 394     if (m->server->fd_ipv4 >= 0 || m->server->config.publish_a_on_ipv6)
 395         avahi_interface_new(m, hw, AVAHI_PROTO_INET);
 396     if (m->server->fd_ipv6 >= 0 || m->server->config.publish_aaaa_on_ipv4)
 397         avahi_interface_new(m, hw, AVAHI_PROTO_INET6);
 398
 399     return hw;
 400 }
 401
 402 AvahiInterfaceAddress *avahi_interface_address_new(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *addr, unsigned prefix_len) {
 403     AvahiInterfaceAddress *a;
 404
 405     assert(m);
 406     assert(i);
 407
 408     if (!(a = avahi_new(AvahiInterfaceAddress, 1)))
 409         return NULL;
 410
 411     a->interface = i;
 412     a->monitor = m;
 413     a->address = *addr;
 414     a->prefix_len = prefix_len;
 415     a->global_scope = 0;
 416     a->entry_group = NULL;
 417
 418     AVAHI_LLIST_PREPEND(AvahiInterfaceAddress, address, i->addresses, a);
 419
 420     return a;
 421 }
 422
 423 void avahi_interface_check_relevant(AvahiInterface *i) {
 424     int b;
 425     AvahiInterfaceMonitor *m;
 426
 427     assert(i);
 428     m = i->monitor;
 429
 430     b = avahi_interface_is_relevant(i);
 431
 432     if (m->list_complete && b && !i->announcing) {
 433         interface_mdns_mcast_join(i, 1);
 434
 435         if (i->mcast_joined) {
 436             avahi_log_info("New relevant interface %s.%s for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 437
 438             i->announcing = 1;
 439             avahi_announce_interface(m->server, i);
 440             avahi_multicast_lookup_engine_new_interface(m->server->multicast_lookup_engine, i);
 441         }
 442
 443     } else if (!b && i->announcing) {
 444         avahi_log_info("Interface %s.%s no longer relevant for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 445
 446         interface_mdns_mcast_join(i, 0);
 447
 448         avahi_goodbye_interface(m->server, i, 0, 1);
 449         avahi_querier_free_all(i);
 450
 451         avahi_response_scheduler_clear(i->response_scheduler);
 452         avahi_query_scheduler_clear(i->query_scheduler);
 453         avahi_probe_scheduler_clear(i->probe_scheduler);
 454         avahi_cache_flush(i->cache);
 455
 456         i->announcing = 0;
 457
 458     } else
 459         interface_mdns_mcast_rejoin(i);
 460 }
 461
 462 void avahi_hw_interface_check_relevant(AvahiHwInterface *hw) {
 463     AvahiInterface *i;
 464
 465     assert(hw);
 466
 467     for (i = hw->interfaces; i; i = i->by_hardware_next)
 468         avahi_interface_check_relevant(i);
 469 }
 470
 471 void avahi_interface_monitor_check_relevant(AvahiInterfaceMonitor *m) {
 472     AvahiInterface *i;
 473
 474     assert(m);
 475
 476     for (i = m->interfaces; i; i = i->interface_next)
 477         avahi_interface_check_relevant(i);
 478 }
 479
 480 AvahiInterfaceMonitor *avahi_interface_monitor_new(AvahiServer *s) {
 481     AvahiInterfaceMonitor *m = NULL;
 482
 483     if (!(m = avahi_new0(AvahiInterfaceMonitor, 1)))
 484         return NULL; /* OOM */
 485
 486     m->server = s;
 487     m->list_complete = 0;
 488     m->hashmap = avahi_hashmap_new(avahi_int_hash, avahi_int_equal, NULL, NULL);
 489
 490     AVAHI_LLIST_HEAD_INIT(AvahiInterface, m->interfaces);
 491     AVAHI_LLIST_HEAD_INIT(AvahiHwInterface, m->hw_interfaces);
 492
 493     if (avahi_interface_monitor_init_osdep(m) < 0)
 494         goto fail;
 495
 496     return m;
 497
 498 fail:
 499     avahi_interface_monitor_free(m);
 500     return NULL;
 501 }
 502
 503 void avahi_interface_monitor_free(AvahiInterfaceMonitor *m) {
 504     assert(m);
 505
 506     while (m->hw_interfaces)
 507         avahi_hw_interface_free(m->hw_interfaces, 1);
 508
 509     assert(!m->interfaces);
 510
 511     avahi_interface_monitor_free_osdep(m);
 512
 513     if (m->hashmap)
 514         avahi_hashmap_free(m->hashmap);
 515
 516     avahi_free(m);
 517 }
 518
 519
 520 AvahiInterface* avahi_interface_monitor_get_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx, AvahiProtocol protocol) {
 521     AvahiHwInterface *hw;
 522     AvahiInterface *i;
 523
 524     assert(m);
 525     assert(idx >= 0);
 526     assert(protocol != AVAHI_PROTO_UNSPEC);
 527
 528     if (!(hw = avahi_interface_monitor_get_hw_interface(m, idx)))
 529         return NULL;
 530
 531     for (i = hw->interfaces; i; i = i->by_hardware_next)
 532         if (i->protocol == protocol)
 533             return i;
 534
 535     return NULL;
 536 }
 537
 538 AvahiHwInterface* avahi_interface_monitor_get_hw_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
 539     assert(m);
 540     assert(idx >= 0);
 541
 542     return avahi_hashmap_lookup(m->hashmap, &idx);
 543 }
 544
 545 AvahiInterfaceAddress* avahi_interface_monitor_get_address(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *raddr) {
 546     AvahiInterfaceAddress *ia;
 547
 548     assert(m);
 549     assert(i);
 550     assert(raddr);
 551
 552     for (ia = i->addresses; ia; ia = ia->address_next)
 553         if (avahi_address_cmp(&ia->address, raddr) == 0)
 554             return ia;
 555
 556     return NULL;
 557 }
 558
 559 void avahi_interface_send_packet_unicast(AvahiInterface *i, AvahiDnsPacket *p, const AvahiAddress *a, uint16_t port) {
 560     assert(i);
 561     assert(p);
 562
 563     if (!i->announcing)
 564         return;
 565
 566     assert(!a || a->proto == i->protocol);
 567
 568     if (i->protocol == AVAHI_PROTO_INET && i->monitor->server->fd_ipv4 >= 0)
 569         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);
 570     else if (i->protocol == AVAHI_PROTO_INET6 && i->monitor->server->fd_ipv6 >= 0)
 571         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);
 572 }
 573
 574 void avahi_interface_send_packet(AvahiInterface *i, AvahiDnsPacket *p) {
 575     assert(i);
 576     assert(p);
 577
 578     avahi_interface_send_packet_unicast(i, p, NULL, 0);
 579 }
 580
 581 int avahi_interface_post_query(AvahiInterface *i, AvahiKey *key, int immediately, unsigned *ret_id) {
 582     assert(i);
 583     assert(key);
 584
 585     if (!i->announcing)
 586         return 0;
 587
 588     return avahi_query_scheduler_post(i->query_scheduler, key, immediately, ret_id);
 589 }
 590
 591 int avahi_interface_withraw_query(AvahiInterface *i, unsigned id) {
 592
 593     return avahi_query_scheduler_withdraw_by_id(i->query_scheduler, id);
 594 }
 595
 596 int avahi_interface_post_response(AvahiInterface *i, AvahiRecord *record, int flush_cache, const AvahiAddress *querier, int immediately) {
 597     assert(i);
 598     assert(record);
 599
 600     if (!i->announcing)
 601         return 0;
 602
 603     return avahi_response_scheduler_post(i->response_scheduler, record, flush_cache, querier, immediately);
 604 }
 605
 606 int avahi_interface_post_probe(AvahiInterface *i, AvahiRecord *record, int immediately) {
 607     assert(i);
 608     assert(record);
 609
 610     if (!i->announcing)
 611         return 0;
 612
 613     return avahi_probe_scheduler_post(i->probe_scheduler, record, immediately);
 614 }
 615
 616 int avahi_dump_caches(AvahiInterfaceMonitor *m, AvahiDumpCallback callback, void* userdata) {
 617     AvahiInterface *i;
 618     assert(m);
 619
 620     for (i = m->interfaces; i; i = i->interface_next) {
 621         if (avahi_interface_is_relevant(i)) {
 622             char ln[256];
 623             snprintf(ln, sizeof(ln), ";;; INTERFACE %s.%s ;;;", i->hardware->name, avahi_proto_to_string(i->protocol));
 624             callback(ln, userdata);
 625             if (avahi_cache_dump(i->cache, callback, userdata) < 0)
 626                 return -1;
 627         }
 628     }
 629
 630     return 0;
 631 }
 632
 633 static int avahi_interface_is_relevant_internal(AvahiInterface *i) {
 634     AvahiInterfaceAddress *a;
 635
 636     assert(i);
 637
 638     if (!i->hardware->flags_ok)
 639         return 0;
 640
 641     for (a = i->addresses; a; a = a->address_next)
 642         if (avahi_interface_address_is_relevant(a))
 643             return 1;
 644
 645     return 0;
 646 }
 647
 648 int avahi_interface_is_relevant(AvahiInterface *i) {
 649     AvahiStringList *l;
 650     assert(i);
 651
 652     for (l = i->monitor->server->config.deny_interfaces; l; l = l->next)
 653         if (strcasecmp((char*) l->text, i->hardware->name) == 0)
 654             return 0;
 655
 656     if (i->monitor->server->config.allow_interfaces) {
 657
 658         for (l = i->monitor->server->config.allow_interfaces; l; l = l->next)
 659             if (strcasecmp((char*) l->text, i->hardware->name) == 0)
 660                 goto good;
 661
 662         return 0;
 663     }
 664
 665 good:
 666     return avahi_interface_is_relevant_internal(i);
 667 }
 668
 669 int avahi_interface_address_is_relevant(AvahiInterfaceAddress *a) {
 670     AvahiInterfaceAddress *b;
 671     assert(a);
 672
 673     /* Publish public IP addresses */
 674     if (a->global_scope)
 675         return 1;
 676     else {
 677
 678         /* Publish link local IP addresses if they are the only ones on the link */
 679         for (b = a->interface->addresses; b; b = b->address_next) {
 680             if (b == a)
 681                 continue;
 682
 683             if (b->global_scope)
 684                 return 0;
 685         }
 686
 687         return 1;
 688     }
 689
 690     return 0;
 691 }
 692
 693 int avahi_interface_match(AvahiInterface *i, AvahiIfIndex idx, AvahiProtocol protocol) {
 694     assert(i);
 695
 696     if (idx != AVAHI_IF_UNSPEC && idx != i->hardware->index)
 697         return 0;
 698
 699     if (protocol != AVAHI_PROTO_UNSPEC && protocol != i->protocol)
 700         return 0;
 701
 702     return 1;
 703 }
 704
 705 void avahi_interface_monitor_walk(AvahiInterfaceMonitor *m, AvahiIfIndex interface, AvahiProtocol protocol, AvahiInterfaceMonitorWalkCallback callback, void* userdata) {
 706     assert(m);
 707     assert(callback);
 708
 709     if (interface != AVAHI_IF_UNSPEC) {
 710         if (protocol != AVAHI_PROTO_UNSPEC) {
 711             AvahiInterface *i;
 712
 713             if ((i = avahi_interface_monitor_get_interface(m, interface, protocol)))
 714                 callback(m, i, userdata);
 715
 716         } else {
 717             AvahiHwInterface *hw;
 718             AvahiInterface *i;
 719
 720             if ((hw = avahi_interface_monitor_get_hw_interface(m, interface)))
 721                 for (i = hw->interfaces; i; i = i->by_hardware_next)
 722                     if (avahi_interface_match(i, interface, protocol))
 723                         callback(m, i, userdata);
 724         }
 725
 726     } else {
 727         AvahiInterface *i;
 728
 729         for (i = m->interfaces; i; i = i->interface_next)
 730             if (avahi_interface_match(i, interface, protocol))
 731                 callback(m, i, userdata);
 732     }
 733 }
 734
 735
 736 int avahi_address_is_local(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
 737     AvahiInterface *i;
 738     AvahiInterfaceAddress *ia;
 739     assert(m);
 740     assert(a);
 741
 742     for (i = m->interfaces; i; i = i->interface_next)
 743         for (ia = i->addresses; ia; ia = ia->address_next)
 744             if (avahi_address_cmp(a, &ia->address) == 0)
 745                 return 1;
 746
 747     return 0;
 748 }
 749
 750 int avahi_interface_address_on_link(AvahiInterface *i, const AvahiAddress *a) {
 751     AvahiInterfaceAddress *ia;
 752
 753     assert(i);
 754     assert(a);
 755
 756     if (a->proto != i->protocol)
 757         return 0;
 758
 759     for (ia = i->addresses; ia; ia = ia->address_next) {
 760
 761         if (a->proto == AVAHI_PROTO_INET) {
 762             uint32_t m;
 763
 764             m = ~(((uint32_t) -1) >> ia->prefix_len);
 765
 766             if ((ntohl(a->data.ipv4.address) & m) == (ntohl(ia->address.data.ipv4.address) & m))
 767                 return 1;
 768         } else {
 769             unsigned j;
 770             unsigned char pl;
 771             assert(a->proto == AVAHI_PROTO_INET6);
 772
 773             pl = ia->prefix_len;
 774
 775             for (j = 0; j < 16; j++) {
 776                 uint8_t m;
 777
 778                 if (pl == 0)
 779                     return 1;
 780
 781                 if (pl >= 8) {
 782                     m = 0xFF;
 783                     pl -= 8;
 784                 } else {
 785                     m = ~(0xFF >> pl);
 786                     pl = 0;
 787                 }
 788
 789                 if ((a->data.ipv6.address[j] & m) != (ia->address.data.ipv6.address[j] & m))
 790                     break;
 791             }
 792         }
 793     }
 794
 795     return 0;
 796 }
 797
 798 int avahi_interface_has_address(AvahiInterfaceMonitor *m, AvahiIfIndex iface, const AvahiAddress *a) {
 799     AvahiInterface *i;
 800     AvahiInterfaceAddress *j;
 801
 802     assert(m);
 803     assert(iface != AVAHI_IF_UNSPEC);
 804     assert(a);
 805
 806     if (!(i = avahi_interface_monitor_get_interface(m, iface, a->proto)))
 807         return 0;
 808
 809     for (j = i->addresses; j; j = j->address_next)
 810         if (avahi_address_cmp(a, &j->address) == 0)
 811             return 1;
 812
 813     return 0;
 814 }
 815
 816 AvahiIfIndex avahi_find_interface_for_address(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
 817     AvahiInterface *i;
 818     assert(m);
 819
 820     /* Some stupid OS don't support passing the interface index when a
 821      * packet is received. We have to work around that limitation by
 822      * looking for an interface that has the incoming address
 823      * attached. This is sometimes ambiguous, but we have to live with
 824      * it. */
 825
 826     for (i = m->interfaces; i; i = i->interface_next) {
 827         AvahiInterfaceAddress *ai;
 828
 829         if (i->protocol != a->proto)
 830             continue;
 831
 832         for (ai = i->addresses; ai; ai = ai->address_next)
 833             if (avahi_address_cmp(a, &ai->address) == 0)
 834                 return i->hardware->index;
 835     }
 836
 837     return AVAHI_IF_UNSPEC;
 838 }