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
  32 #define AVAHI_ANNOUNCEMENT_JITTER_MSEC 250
  33 #define AVAHI_PROBE_JITTER_MSEC 250
  34 #define AVAHI_PROBE_INTERVAL_MSEC 250
  35
  36 static void remove_announcement(AvahiServer *s, AvahiAnnouncement *a) {
  37     assert(s);
  38     assert(a);
  39
  40     if (a->time_event)
  41         avahi_time_event_free(a->time_event);
  42
  43     AVAHI_LLIST_REMOVE(AvahiAnnouncement, by_interface, a->interface->announcements, a);
  44     AVAHI_LLIST_REMOVE(AvahiAnnouncement, by_entry, a->entry->announcements, a);
  45
  46     avahi_free(a);
  47 }
  48
  49 static void elapse_announce(AvahiTimeEvent *e, void *userdata);
  50
  51 static void set_timeout(AvahiAnnouncement *a, const struct timeval *tv) {
  52     assert(a);
  53
  54     if (!tv) {
  55         if (a->time_event) {
  56             avahi_time_event_free(a->time_event);
  57             a->time_event = NULL;
  58         }
  59     } else {
  60
  61         if (a->time_event)
  62             avahi_time_event_update(a->time_event, tv);
  63         else
  64             a->time_event = avahi_time_event_new(a->server->time_event_queue, tv, elapse_announce, a);
  65     }
  66 }
  67
  68 static void next_state(AvahiAnnouncement *a);
  69
  70 void avahi_s_entry_group_check_probed(AvahiSEntryGroup *g, int immediately) {
  71     AvahiEntry *e;
  72     assert(g);
  73     assert(!g->dead);
  74
  75     /* Check whether all group members have been probed */
  76
  77     if (g->state != AVAHI_ENTRY_GROUP_REGISTERING || g->n_probing > 0)
  78         return;
  79
  80     avahi_s_entry_group_change_state(g, AVAHI_ENTRY_GROUP_ESTABLISHED);
  81
  82     if (g->dead)
  83         return;
  84
  85     for (e = g->entries; e; e = e->entries_next) {
  86         AvahiAnnouncement *a;
  87
  88         for (a = e->announcements; a; a = a->by_entry_next) {
  89
  90             if (a->state != AVAHI_WAITING)
  91                 continue;
  92
  93             a->state = AVAHI_ANNOUNCING;
  94
  95             if (immediately) {
  96                 /* Shortcut */
  97
  98                 a->n_iteration = 1;
  99                 next_state(a);
 100             } else {
 101                 struct timeval tv;
 102                 a->n_iteration = 0;
 103                 avahi_elapse_time(&tv, 0, AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 104                 set_timeout(a, &tv);
 105             }
 106         }
 107     }
 108 }
 109
 110 static void next_state(AvahiAnnouncement *a) {
 111     assert(a);
 112
 113 /*     avahi_log_debug("%i -- %u", a->state, a->n_iteration);   */
 114
 115     if (a->state == AVAHI_WAITING) {
 116
 117         assert(a->entry->group);
 118
 119         avahi_s_entry_group_check_probed(a->entry->group, 1);
 120
 121     } else if (a->state == AVAHI_PROBING) {
 122
 123         if (a->n_iteration >= 4) {
 124             /* Probing done */
 125
 126 /*             char *t; */
 127
 128 /*             avahi_log_debug("Enough probes for record [%s]", t = avahi_record_to_string(a->entry->record)); */
 129 /*             avahi_free(t); */
 130
 131             if (a->entry->group) {
 132                 assert(a->entry->group->n_probing);
 133                 a->entry->group->n_probing--;
 134             }
 135
 136             if (a->entry->group && a->entry->group->state == AVAHI_ENTRY_GROUP_REGISTERING)
 137                 a->state = AVAHI_WAITING;
 138             else {
 139                 a->state = AVAHI_ANNOUNCING;
 140                 a->n_iteration = 1;
 141             }
 142
 143             set_timeout(a, NULL);
 144             next_state(a);
 145         } else {
 146             struct timeval tv;
 147
 148             avahi_interface_post_probe(a->interface, a->entry->record, 0);
 149
 150             avahi_elapse_time(&tv, AVAHI_PROBE_INTERVAL_MSEC, 0);
 151             set_timeout(a, &tv);
 152
 153             a->n_iteration++;
 154         }
 155
 156     } else if (a->state == AVAHI_ANNOUNCING) {
 157
 158         if (a->entry->flags & AVAHI_PUBLISH_UNIQUE)
 159             /* Send the whole rrset at once */
 160             avahi_server_prepare_matching_responses(a->server, a->interface, a->entry->record->key, 0);
 161         else
 162             avahi_server_prepare_response(a->server, a->interface, a->entry, 0, 0);
 163
 164         avahi_server_generate_response(a->server, a->interface, NULL, NULL, 0, 0, 0);
 165
 166         if (++a->n_iteration >= 4) {
 167 /*             char *t; */
 168             /* Announcing done */
 169
 170 /*             avahi_log_debug("Enough announcements for record [%s]", t = avahi_record_to_string(a->entry->record)); */
 171 /*             avahi_free(t); */
 172
 173             a->state = AVAHI_ESTABLISHED;
 174
 175             set_timeout(a, NULL);
 176         } else {
 177             struct timeval tv;
 178             avahi_elapse_time(&tv, a->sec_delay*1000, AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 179
 180             if (a->n_iteration < 10)
 181                 a->sec_delay *= 2;
 182
 183             set_timeout(a, &tv);
 184         }
 185     }
 186 }
 187
 188 static void elapse_announce(AvahiTimeEvent *e, void *userdata) {
 189     assert(e);
 190
 191     next_state(userdata);
 192 }
 193
 194 AvahiAnnouncement *avahi_get_announcement(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 195     AvahiAnnouncement *a;
 196
 197     assert(s);
 198     assert(e);
 199     assert(i);
 200
 201     for (a = e->announcements; a; a = a->by_entry_next)
 202         if (a->interface == i)
 203             return a;
 204
 205     return NULL;
 206 }
 207
 208 static void go_to_initial_state(AvahiAnnouncement *a, int immediately) {
 209     AvahiEntry *e;
 210     struct timeval tv;
 211
 212     assert(a);
 213     e = a->entry;
 214
 215     if ((e->flags & AVAHI_PUBLISH_UNIQUE) && !(e->flags & AVAHI_PUBLISH_NO_PROBE))
 216         a->state = AVAHI_PROBING;
 217     else if (!(e->flags & AVAHI_PUBLISH_NO_ANNOUNCE)) {
 218
 219         if (!e->group || e->group->state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 220             a->state = AVAHI_ANNOUNCING;
 221         else
 222             a->state = AVAHI_WAITING;
 223
 224     } else
 225         a->state = AVAHI_ESTABLISHED;
 226
 227     a->n_iteration = 1;
 228     a->sec_delay = 1;
 229
 230     if (a->state == AVAHI_PROBING && e->group)
 231         e->group->n_probing++;
 232
 233     if (a->state == AVAHI_PROBING)
 234         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_PROBE_JITTER_MSEC));
 235     else if (a->state == AVAHI_ANNOUNCING)
 236         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_ANNOUNCEMENT_JITTER_MSEC));
 237     else
 238         set_timeout(a, NULL);
 239 }
 240
 241 static void new_announcement(AvahiServer *s, AvahiInterface *i, AvahiEntry *e) {
 242     AvahiAnnouncement *a;
 243 /*     char *t;  */
 244
 245     assert(s);
 246     assert(i);
 247     assert(e);
 248     assert(!e->dead);
 249
 250 /*     avahi_log_debug("NEW ANNOUNCEMENT: %s.%i [%s]", i->hardware->name, i->protocol, t = avahi_record_to_string(e->record)); */
 251 /*     avahi_free(t); */
 252
 253     if (!avahi_interface_match(i, e->interface, e->protocol) || !i->announcing || !avahi_entry_is_commited(e))
 254         return;
 255
 256     /* We don't want duplicate announcements */
 257     if (avahi_get_announcement(s, e, i))
 258         return;
 259
 260     if ((!(a = avahi_new(AvahiAnnouncement, 1)))) {
 261         avahi_log_error(__FILE__": Out of memory.");
 262         return;
 263     }
 264
 265     a->server = s;
 266     a->interface = i;
 267     a->entry = e;
 268     a->time_event = NULL;
 269
 270     AVAHI_LLIST_PREPEND(AvahiAnnouncement, by_interface, i->announcements, a);
 271     AVAHI_LLIST_PREPEND(AvahiAnnouncement, by_entry, e->announcements, a);
 272
 273     go_to_initial_state(a, 0);
 274
 275 /*     avahi_log_debug("New announcement on interface %s.%i for entry [%s] state=%i", i->hardware->name, i->protocol, t = avahi_record_to_string(e->record), a->state); */
 276 /*     avahi_free(t); */
 277 }
 278
 279 void avahi_announce_interface(AvahiServer *s, AvahiInterface *i) {
 280     AvahiEntry *e;
 281
 282     assert(s);
 283     assert(i);
 284
 285     if (!i->announcing)
 286         return;
 287
 288     for (e = s->entries; e; e = e->entries_next)
 289         if (!e->dead)
 290             new_announcement(s, i, e);
 291 }
 292
 293 static void announce_walk_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 294     AvahiEntry *e = userdata;
 295
 296     assert(m);
 297     assert(i);
 298     assert(e);
 299     assert(!e->dead);
 300
 301     new_announcement(m->server, i, e);
 302 }
 303
 304 void avahi_announce_entry(AvahiServer *s, AvahiEntry *e) {
 305     assert(s);
 306     assert(e);
 307     assert(!e->dead);
 308
 309     avahi_interface_monitor_walk(s->monitor, e->interface, e->protocol, announce_walk_callback, e);
 310 }
 311
 312 void avahi_announce_group(AvahiServer *s, AvahiSEntryGroup *g) {
 313     AvahiEntry *e;
 314
 315     assert(s);
 316     assert(g);
 317
 318     for (e = g->entries; e; e = e->by_group_next)
 319         if (!e->dead)
 320             avahi_announce_entry(s, e);
 321 }
 322
 323 int avahi_entry_is_registered(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 324     AvahiAnnouncement *a;
 325
 326     assert(s);
 327     assert(e);
 328     assert(i);
 329     assert(!e->dead);
 330
 331     if (!(a = avahi_get_announcement(s, e, i)))
 332         return 0;
 333
 334     return
 335         a->state == AVAHI_ANNOUNCING ||
 336         a->state == AVAHI_ESTABLISHED ||
 337         (a->state == AVAHI_WAITING && !(e->flags & AVAHI_PUBLISH_UNIQUE));
 338 }
 339
 340 int avahi_entry_is_probing(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 341     AvahiAnnouncement *a;
 342
 343     assert(s);
 344     assert(e);
 345     assert(i);
 346     assert(!e->dead);
 347
 348     if (!(a = avahi_get_announcement(s, e, i)))
 349         return 0;
 350
 351 /*     avahi_log_debug("state: %i", a->state); */
 352
 353     return
 354         a->state == AVAHI_PROBING ||
 355         (a->state == AVAHI_WAITING && (e->flags & AVAHI_PUBLISH_UNIQUE));
 356 }
 357
 358 void avahi_entry_return_to_initial_state(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 359     AvahiAnnouncement *a;
 360
 361     assert(s);
 362     assert(e);
 363     assert(i);
 364
 365     if (!(a = avahi_get_announcement(s, e, i)))
 366         return;
 367
 368     if (a->state == AVAHI_PROBING && a->entry->group)
 369         a->entry->group->n_probing--;
 370
 371     go_to_initial_state(a, 1);
 372 }
 373
 374 static AvahiRecord *make_goodbye_record(AvahiRecord *r) {
 375 /*     char *t; */
 376     AvahiRecord *g;
 377
 378     assert(r);
 379
 380 /*     avahi_log_debug("Preparing goodbye for record [%s]", t = avahi_record_to_string(r)); */
 381 /*     avahi_free(t); */
 382
 383     if (!(g = avahi_record_copy(r)))
 384         return NULL; /* OOM */
 385
 386     assert(g->ref == 1);
 387     g->ttl = 0;
 388
 389     return g;
 390 }
 391
 392 static int is_duplicate_entry(AvahiServer *s, AvahiEntry *e) {
 393     AvahiEntry *i;
 394
 395     assert(s);
 396     assert(e);
 397
 398     for (i = avahi_hashmap_lookup(s->entries_by_key, e->record->key); i; i = i->by_key_next) {
 399
 400         if (i == e)
 401             continue;
 402
 403         if (!avahi_record_equal_no_ttl(i->record, e->record))
 404             continue;
 405
 406         return 1;
 407     }
 408
 409     return 0;
 410 }
 411
 412 static void send_goodbye_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 413     AvahiEntry *e = userdata;
 414     AvahiRecord *g;
 415
 416     assert(m);
 417     assert(i);
 418     assert(e);
 419     assert(!e->dead);
 420
 421     if (!avahi_interface_match(i, e->interface, e->protocol))
 422         return;
 423
 424     if (e->flags & AVAHI_PUBLISH_NO_ANNOUNCE)
 425         return;
 426
 427     if (!avahi_entry_is_registered(m->server, e, i))
 428         return;
 429
 430     if (is_duplicate_entry(m->server, e))
 431         return;
 432
 433     if (!(g = make_goodbye_record(e->record)))
 434         return; /* OOM */
 435
 436     avahi_interface_post_response(i, g, e->flags & AVAHI_PUBLISH_UNIQUE, NULL, 1);
 437     avahi_record_unref(g);
 438 }
 439
 440 static void reannounce(AvahiAnnouncement *a) {
 441     AvahiEntry *e;
 442     struct timeval tv;
 443
 444     assert(a);
 445     e = a->entry;
 446
 447     /* If the group this entry belongs to is not even commited, there's nothing to reannounce */
 448     if (e->group && (e->group->state == AVAHI_ENTRY_GROUP_UNCOMMITED || e->group->state == AVAHI_ENTRY_GROUP_COLLISION))
 449         return;
 450
 451     /* Because we might change state we decrease the probing counter first */
 452     if (a->state == AVAHI_PROBING && a->entry->group)
 453         a->entry->group->n_probing--;
 454
 455     if (a->state == AVAHI_PROBING ||
 456         (a->state == AVAHI_WAITING && (e->flags & AVAHI_PUBLISH_UNIQUE) && !(e->flags & AVAHI_PUBLISH_NO_PROBE)))
 457
 458         /* We were probing or waiting after probe, so we restart probing from the beginning here */
 459
 460         a->state = AVAHI_PROBING;
 461     else if (a->state == AVAHI_WAITING)
 462
 463         /* We were waiting, but were not probing before, so we continue waiting  */
 464         a->state = AVAHI_WAITING;
 465
 466     else if (e->flags & AVAHI_PUBLISH_NO_ANNOUNCE)
 467
 468         /* No announcement needed */
 469         a->state = AVAHI_ESTABLISHED;
 470
 471     else {
 472
 473         /* Ok, let's restart announcing */
 474         a->state = AVAHI_ANNOUNCING;
 475     }
 476
 477     /* Now let's increase the probing counter again */
 478     if (a->state == AVAHI_PROBING && e->group)
 479         e->group->n_probing++;
 480
 481     a->n_iteration = 1;
 482     a->sec_delay = 1;
 483
 484     if (a->state == AVAHI_PROBING)
 485         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_PROBE_JITTER_MSEC));
 486     else if (a->state == AVAHI_ANNOUNCING)
 487         set_timeout(a, avahi_elapse_time(&tv, 0, AVAHI_ANNOUNCEMENT_JITTER_MSEC));
 488     else
 489         set_timeout(a, NULL);
 490 }
 491
 492
 493 static void reannounce_walk_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 494     AvahiEntry *e = userdata;
 495     AvahiAnnouncement *a;
 496
 497     assert(m);
 498     assert(i);
 499     assert(e);
 500     assert(!e->dead);
 501
 502     if (!(a = avahi_get_announcement(m->server, e, i)))
 503         return;
 504
 505     reannounce(a);
 506 }
 507
 508 void avahi_reannounce_entry(AvahiServer *s, AvahiEntry *e) {
 509
 510     assert(s);
 511     assert(e);
 512     assert(!e->dead);
 513
 514     avahi_interface_monitor_walk(s->monitor, e->interface, e->protocol, reannounce_walk_callback, e);
 515 }
 516
 517 void avahi_goodbye_interface(AvahiServer *s, AvahiInterface *i, int send_goodbye, int remove) {
 518     assert(s);
 519     assert(i);
 520
 521     if (send_goodbye)
 522         if (avahi_interface_is_relevant(i)) {
 523             AvahiEntry *e;
 524
 525             for (e = s->entries; e; e = e->entries_next)
 526                 if (!e->dead)
 527                     send_goodbye_callback(s->monitor, i, e);
 528         }
 529
 530     if (remove)
 531         while (i->announcements)
 532             remove_announcement(s, i->announcements);
 533 }
 534
 535 void avahi_goodbye_entry(AvahiServer *s, AvahiEntry *e, int send_goodbye, int remove) {
 536     assert(s);
 537     assert(e);
 538
 539     if (send_goodbye)
 540         if (!e->dead)
 541             avahi_interface_monitor_walk(s->monitor, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, send_goodbye_callback, e);
 542
 543     if (remove)
 544         while (e->announcements)
 545             remove_announcement(s, e->announcements);
 546 }
 547
 548 void avahi_goodbye_all(AvahiServer *s, int send_goodbye, int remove) {
 549     AvahiEntry *e;
 550
 551     assert(s);
 552
 553     for (e = s->entries; e; e = e->entries_next)
 554         if (!e->dead)
 555             avahi_goodbye_entry(s, e, send_goodbye, remove);
 556
 557 }
 558