git.meshlink.io Git - catta/blob - avahi-core/announce.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 <avahi-common/timeval.h>
  27 #include <avahi-common/malloc.h>
  28
  29 #include "announce.h"
  30 #include "log.h"
  31 #include "rr-util.h"
  32
  33 #define AVAHI_ANNOUNCEMENT_JITTER_MSEC 250
  34 #define AVAHI_PROBE_JITTER_MSEC 250
  35 #define AVAHI_PROBE_INTERVAL_MSEC 250
  36
  37 static void remove_announcer(AvahiServer *s, AvahiAnnouncer *a) {
  38     assert(s);
  39     assert(a);
  40
  41     if (a->time_event)
  42         avahi_time_event_free(a->time_event);
  43
  44     AVAHI_LLIST_REMOVE(AvahiAnnouncer, by_interface, a->interface->announcers, a);
  45     AVAHI_LLIST_REMOVE(AvahiAnnouncer, by_entry, a->entry->announcers, a);
  46
  47     avahi_free(a);
  48 }
  49
  50 static void elapse_announce(AvahiTimeEvent *e, void *userdata);
  51
  52 static void set_timeout(AvahiAnnouncer *a, const struct timeval *tv) {
  53     assert(a);
  54
  55     if (!tv) {
  56         if (a->time_event) {
  57             avahi_time_event_free(a->time_event);
  58             a->time_event = NULL;
  59         }
  60     } else {
  61
  62         if (a->time_event)
  63             avahi_time_event_update(a->time_event, tv);
  64         else
  65             a->time_event = avahi_time_event_new(a->server->time_event_queue, tv, elapse_announce, a);
  66     }
  67 }
  68
  69 static void next_state(AvahiAnnouncer *a);
  70
  71 void avahi_s_entry_group_check_probed(AvahiSEntryGroup *g, int immediately) {
  72     AvahiEntry *e;
  73     assert(g);
  74     assert(!g->dead);
  75
  76     /* Check whether all group members have been probed */
  77
  78     if (g->state != AVAHI_ENTRY_GROUP_REGISTERING || g->n_probing > 0)
  79         return;
  80
  81     avahi_s_entry_group_change_state(g, AVAHI_ENTRY_GROUP_ESTABLISHED);
  82
  83     if (g->dead)
  84         return;
  85
  86     for (e = g->entries; e; e = e->entries_next) {
  87         AvahiAnnouncer *a;
  88
  89         for (a = e->announcers; a; a = a->by_entry_next) {
  90
  91             if (a->state != AVAHI_WAITING)
  92                 continue;
  93
  94             a->state = AVAHI_ANNOUNCING;
  95
  96             if (immediately) {
  97                 /* Shortcut */
  98
  99                 a->n_iteration = 1;
 100                 next_state(a);
 101             } else {
 102                 struct timeval tv;
 103                 a->n_iteration = 0;
 104                 avahi_elapse_time(&tv, 0, AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 105                 set_timeout(a, &tv);
 106             }
 107         }
 108     }
 109 }
 110
 111 static void next_state(AvahiAnnouncer *a) {
 112     assert(a);
 113
 114 /*     avahi_log_debug("%i -- %u", a->state, a->n_iteration);   */
 115
 116     if (a->state == AVAHI_WAITING) {
 117
 118         assert(a->entry->group);
 119
 120         avahi_s_entry_group_check_probed(a->entry->group, 1);
 121
 122     } else if (a->state == AVAHI_PROBING) {
 123
 124         if (a->n_iteration >= 4) {
 125             /* Probing done */
 126
 127 /*             char *t; */
 128
 129 /*             avahi_log_debug("Enough probes for record [%s]", t = avahi_record_to_string(a->entry->record)); */
 130 /*             avahi_free(t); */
 131
 132             if (a->entry->group) {
 133                 assert(a->entry->group->n_probing);
 134                 a->entry->group->n_probing--;
 135             }
 136
 137             if (a->entry->group && a->entry->group->state == AVAHI_ENTRY_GROUP_REGISTERING)
 138                 a->state = AVAHI_WAITING;
 139             else {
 140                 a->state = AVAHI_ANNOUNCING;
 141                 a->n_iteration = 1;
 142             }
 143
 144             set_timeout(a, NULL);
 145             next_state(a);
 146         } else {
 147             struct timeval tv;
 148
 149             avahi_interface_post_probe(a->interface, a->entry->record, 0);
 150
 151             avahi_elapse_time(&tv, AVAHI_PROBE_INTERVAL_MSEC, 0);
 152             set_timeout(a, &tv);
 153
 154             a->n_iteration++;
 155         }
 156
 157     } else if (a->state == AVAHI_ANNOUNCING) {
 158
 159         if (a->entry->flags & AVAHI_PUBLISH_UNIQUE)
 160             /* Send the whole rrset at once */
 161             avahi_server_prepare_matching_responses(a->server, a->interface, a->entry->record->key, 0);
 162         else
 163             avahi_server_prepare_response(a->server, a->interface, a->entry, 0, 0);
 164
 165         avahi_server_generate_response(a->server, a->interface, NULL, NULL, 0, 0, 0);
 166
 167         if (++a->n_iteration >= 4) {
 168 /*             char *t; */
 169             /* Announcing done */
 170
 171 /*             avahi_log_debug("Enough announcements for record [%s]", t = avahi_record_to_string(a->entry->record)); */
 172 /*             avahi_free(t); */
 173
 174             a->state = AVAHI_ESTABLISHED;
 175
 176             set_timeout(a, NULL);
 177         } else {
 178             struct timeval tv;
 179             avahi_elapse_time(&tv, a->sec_delay*1000, AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 180
 181             if (a->n_iteration < 10)
 182                 a->sec_delay *= 2;
 183
 184             set_timeout(a, &tv);
 185         }
 186     }
 187 }
 188
 189 static void elapse_announce(AvahiTimeEvent *e, void *userdata) {
 190     assert(e);
 191
 192     next_state(userdata);
 193 }
 194
 195 static AvahiAnnouncer *get_announcer(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 196     AvahiAnnouncer *a;
 197
 198     assert(s);
 199     assert(e);
 200     assert(i);
 201
 202     for (a = e->announcers; a; a = a->by_entry_next)
 203         if (a->interface == i)
 204             return a;
 205
 206     return NULL;
 207 }
 208
 209 static void go_to_initial_state(AvahiAnnouncer *a, int immediately) {
 210     AvahiEntry *e;
 211     struct timeval tv;
 212
 213     assert(a);
 214     e = a->entry;
 215
 216     if ((e->flags & AVAHI_PUBLISH_UNIQUE) && !(e->flags & AVAHI_PUBLISH_NO_PROBE))
 217         a->state = AVAHI_PROBING;
 218     else if (!(e->flags & AVAHI_PUBLISH_NO_ANNOUNCE)) {
 219
 220         if (!e->group || e->group->state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 221             a->state = AVAHI_ANNOUNCING;
 222         else
 223             a->state = AVAHI_WAITING;
 224
 225     } else
 226         a->state = AVAHI_ESTABLISHED;
 227
 228     a->n_iteration = 1;
 229     a->sec_delay = 1;
 230
 231     if (a->state == AVAHI_PROBING && e->group)
 232         e->group->n_probing++;
 233
 234     if (a->state == AVAHI_PROBING)
 235         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_PROBE_JITTER_MSEC));
 236     else if (a->state == AVAHI_ANNOUNCING)
 237         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_ANNOUNCEMENT_JITTER_MSEC));
 238     else
 239         set_timeout(a, NULL);
 240 }
 241
 242 static void new_announcer(AvahiServer *s, AvahiInterface *i, AvahiEntry *e) {
 243     AvahiAnnouncer *a;
 244 /*     char *t;  */
 245
 246     assert(s);
 247     assert(i);
 248     assert(e);
 249     assert(!e->dead);
 250
 251 /*     avahi_log_debug("NEW ANNOUNCER: %s.%i [%s]", i->hardware->name, i->protocol, t = avahi_record_to_string(e->record)); */
 252 /*     avahi_free(t); */
 253
 254     if (!avahi_interface_match(i, e->interface, e->protocol) || !i->announcing || !avahi_entry_is_commited(e))
 255         return;
 256
 257     /* We don't want duplicate announcers */
 258     if (get_announcer(s, e, i))
 259         return;
 260
 261     if ((!(a = avahi_new(AvahiAnnouncer, 1)))) {
 262         avahi_log_error(__FILE__": Out of memory.");
 263         return;
 264     }
 265
 266     a->server = s;
 267     a->interface = i;
 268     a->entry = e;
 269     a->time_event = NULL;
 270
 271     AVAHI_LLIST_PREPEND(AvahiAnnouncer, by_interface, i->announcers, a);
 272     AVAHI_LLIST_PREPEND(AvahiAnnouncer, by_entry, e->announcers, a);
 273
 274     go_to_initial_state(a, 0);
 275
 276 /*     avahi_log_debug("New announcer on interface %s.%i for entry [%s] state=%i", i->hardware->name, i->protocol, t = avahi_record_to_string(e->record), a->state); */
 277 /*     avahi_free(t); */
 278 }
 279
 280 void avahi_announce_interface(AvahiServer *s, AvahiInterface *i) {
 281     AvahiEntry *e;
 282
 283     assert(s);
 284     assert(i);
 285
 286     if (!i->announcing)
 287         return;
 288
 289     for (e = s->entries; e; e = e->entries_next)
 290         if (!e->dead)
 291             new_announcer(s, i, e);
 292 }
 293
 294 static void announce_walk_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 295     AvahiEntry *e = userdata;
 296
 297     assert(m);
 298     assert(i);
 299     assert(e);
 300     assert(!e->dead);
 301
 302     new_announcer(m->server, i, e);
 303 }
 304
 305 void avahi_announce_entry(AvahiServer *s, AvahiEntry *e) {
 306     assert(s);
 307     assert(e);
 308     assert(!e->dead);
 309
 310     avahi_interface_monitor_walk(s->monitor, e->interface, e->protocol, announce_walk_callback, e);
 311 }
 312
 313 void avahi_announce_group(AvahiServer *s, AvahiSEntryGroup *g) {
 314     AvahiEntry *e;
 315
 316     assert(s);
 317     assert(g);
 318
 319     for (e = g->entries; e; e = e->by_group_next)
 320         if (!e->dead)
 321             avahi_announce_entry(s, e);
 322 }
 323
 324 int avahi_entry_is_registered(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 325     AvahiAnnouncer *a;
 326
 327     assert(s);
 328     assert(e);
 329     assert(i);
 330     assert(!e->dead);
 331
 332     if (!(a = get_announcer(s, e, i)))
 333         return 0;
 334
 335     return
 336         a->state == AVAHI_ANNOUNCING ||
 337         a->state == AVAHI_ESTABLISHED ||
 338         (a->state == AVAHI_WAITING && !(e->flags & AVAHI_PUBLISH_UNIQUE));
 339 }
 340
 341 int avahi_entry_is_probing(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 342     AvahiAnnouncer *a;
 343
 344     assert(s);
 345     assert(e);
 346     assert(i);
 347     assert(!e->dead);
 348
 349     if (!(a = get_announcer(s, e, i)))
 350         return 0;
 351
 352 /*     avahi_log_debug("state: %i", a->state); */
 353
 354     return
 355         a->state == AVAHI_PROBING ||
 356         (a->state == AVAHI_WAITING && (e->flags & AVAHI_PUBLISH_UNIQUE));
 357 }
 358
 359 void avahi_entry_return_to_initial_state(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 360     AvahiAnnouncer *a;
 361
 362     assert(s);
 363     assert(e);
 364     assert(i);
 365
 366     if (!(a = get_announcer(s, e, i)))
 367         return;
 368
 369     if (a->state == AVAHI_PROBING && a->entry->group)
 370         a->entry->group->n_probing--;
 371
 372     go_to_initial_state(a, 1);
 373 }
 374
 375 static AvahiRecord *make_goodbye_record(AvahiRecord *r) {
 376 /*     char *t; */
 377     AvahiRecord *g;
 378
 379     assert(r);
 380
 381 /*     avahi_log_debug("Preparing goodbye for record [%s]", t = avahi_record_to_string(r)); */
 382 /*     avahi_free(t); */
 383
 384     if (!(g = avahi_record_copy(r)))
 385         return NULL; /* OOM */
 386
 387     assert(g->ref == 1);
 388     g->ttl = 0;
 389
 390     return g;
 391 }
 392
 393 static int is_duplicate_entry(AvahiServer *s, AvahiEntry *e) {
 394     AvahiEntry *i;
 395
 396     assert(s);
 397     assert(e);
 398
 399     for (i = avahi_hashmap_lookup(s->entries_by_key, e->record->key); i; i = i->by_key_next) {
 400
 401         if (i == e)
 402             continue;
 403
 404         if (!avahi_record_equal_no_ttl(i->record, e->record))
 405             continue;
 406
 407         return 1;
 408     }
 409
 410     return 0;
 411 }
 412
 413 static void send_goodbye_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 414     AvahiEntry *e = userdata;
 415     AvahiRecord *g;
 416
 417     assert(m);
 418     assert(i);
 419     assert(e);
 420     assert(!e->dead);
 421
 422     if (!avahi_interface_match(i, e->interface, e->protocol))
 423         return;
 424
 425     if (e->flags & AVAHI_PUBLISH_NO_ANNOUNCE)
 426         return;
 427
 428     if (!avahi_entry_is_registered(m->server, e, i))
 429         return;
 430
 431     if (is_duplicate_entry(m->server, e))
 432         return;
 433
 434     if (!(g = make_goodbye_record(e->record)))
 435         return; /* OOM */
 436
 437     avahi_interface_post_response(i, g, e->flags & AVAHI_PUBLISH_UNIQUE, NULL, 1);
 438     avahi_record_unref(g);
 439 }
 440
 441 static void reannounce(AvahiAnnouncer *a) {
 442     AvahiEntry *e;
 443     struct timeval tv;
 444
 445     assert(a);
 446     e = a->entry;
 447
 448     /* If the group this entry belongs to is not even commited, there's nothing to reannounce */
 449     if (e->group && (e->group->state == AVAHI_ENTRY_GROUP_UNCOMMITED || e->group->state == AVAHI_ENTRY_GROUP_COLLISION))
 450         return;
 451
 452     /* Because we might change state we decrease the probing counter first */
 453     if (a->state == AVAHI_PROBING && a->entry->group)
 454         a->entry->group->n_probing--;
 455
 456     if (a->state == AVAHI_PROBING ||
 457         (a->state == AVAHI_WAITING && (e->flags & AVAHI_PUBLISH_UNIQUE) && !(e->flags & AVAHI_PUBLISH_NO_PROBE)))
 458
 459         /* We were probing or waiting after probe, so we restart probing from the beginning here */
 460
 461         a->state = AVAHI_PROBING;
 462     else if (a->state == AVAHI_WAITING)
 463
 464         /* We were waiting, but were not probing before, so we continue waiting  */
 465         a->state = AVAHI_WAITING;
 466
 467     else if (e->flags & AVAHI_PUBLISH_NO_ANNOUNCE)
 468
 469         /* No announcer needed */
 470         a->state = AVAHI_ESTABLISHED;
 471
 472     else {
 473
 474         /* Ok, let's restart announcing */
 475         a->state = AVAHI_ANNOUNCING;
 476     }
 477
 478     /* Now let's increase the probing counter again */
 479     if (a->state == AVAHI_PROBING && e->group)
 480         e->group->n_probing++;
 481
 482     a->n_iteration = 1;
 483     a->sec_delay = 1;
 484
 485     if (a->state == AVAHI_PROBING)
 486         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_PROBE_JITTER_MSEC));
 487     else if (a->state == AVAHI_ANNOUNCING)
 488         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_ANNOUNCEMENT_JITTER_MSEC));
 489     else
 490         set_timeout(a, NULL);
 491 }
 492
 493
 494 static void reannounce_walk_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 495     AvahiEntry *e = userdata;
 496     AvahiAnnouncer *a;
 497
 498     assert(m);
 499     assert(i);
 500     assert(e);
 501     assert(!e->dead);
 502
 503     if (!(a = get_announcer(m->server, e, i)))
 504         return;
 505
 506     reannounce(a);
 507 }
 508
 509 void avahi_reannounce_entry(AvahiServer *s, AvahiEntry *e) {
 510
 511     assert(s);
 512     assert(e);
 513     assert(!e->dead);
 514
 515     avahi_interface_monitor_walk(s->monitor, e->interface, e->protocol, reannounce_walk_callback, e);
 516 }
 517
 518 void avahi_goodbye_interface(AvahiServer *s, AvahiInterface *i, int send_goodbye, int remove) {
 519     assert(s);
 520     assert(i);
 521
 522     if (send_goodbye)
 523         if (avahi_interface_is_relevant(i)) {
 524             AvahiEntry *e;
 525
 526             for (e = s->entries; e; e = e->entries_next)
 527                 if (!e->dead)
 528                     send_goodbye_callback(s->monitor, i, e);
 529         }
 530
 531     if (remove)
 532         while (i->announcers)
 533             remove_announcer(s, i->announcers);
 534 }
 535
 536 void avahi_goodbye_entry(AvahiServer *s, AvahiEntry *e, int send_goodbye, int remove) {
 537     assert(s);
 538     assert(e);
 539
 540     if (send_goodbye)
 541         if (!e->dead)
 542             avahi_interface_monitor_walk(s->monitor, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, send_goodbye_callback, e);
 543
 544     if (remove)
 545         while (e->announcers)
 546             remove_announcer(s, e->announcers);
 547 }
 548