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_ENTRY_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_ENTRY_UNIQUE) && !(e->flags & AVAHI_ENTRY_NOPROBE))
 216         a->state = AVAHI_PROBING;
 217     else if (!(e->flags & AVAHI_ENTRY_NOANNOUNCE)) {
 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         avahi_elapse_time(&tv, 0, immediately ? 0 : AVAHI_PROBE_JITTER_MSEC);
 235         set_timeout(a, &tv);
 236     } else if (a->state == AVAHI_ANNOUNCING) {
 237         avahi_elapse_time(&tv, 0, immediately ? 0 : AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 238         set_timeout(a, &tv);
 239     } else
 240         set_timeout(a, NULL);
 241 }
 242
 243 static void new_announcement(AvahiServer *s, AvahiInterface *i, AvahiEntry *e) {
 244     AvahiAnnouncement *a;
 245 /*     char *t;  */
 246
 247     assert(s);
 248     assert(i);
 249     assert(e);
 250     assert(!e->dead);
 251
 252 /*     avahi_log_debug("NEW ANNOUNCEMENT: %s.%i [%s]", i->hardware->name, i->protocol, t = avahi_record_to_string(e->record)); */
 253 /*     avahi_free(t); */
 254
 255     if (!avahi_interface_match(i, e->interface, e->protocol) || !i->announcing || !avahi_entry_is_commited(e))
 256         return;
 257
 258     /* We don't want duplicate announcements */
 259     if (avahi_get_announcement(s, e, i))
 260         return;
 261
 262     if ((!(a = avahi_new(AvahiAnnouncement, 1)))) {
 263         avahi_log_error(__FILE__": Out of memory.");
 264         return;
 265     }
 266
 267     a->server = s;
 268     a->interface = i;
 269     a->entry = e;
 270     a->time_event = NULL;
 271
 272     AVAHI_LLIST_PREPEND(AvahiAnnouncement, by_interface, i->announcements, a);
 273     AVAHI_LLIST_PREPEND(AvahiAnnouncement, by_entry, e->announcements, a);
 274
 275     go_to_initial_state(a, 0);
 276
 277 /*     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); */
 278 /*     avahi_free(t); */
 279 }
 280
 281 void avahi_announce_interface(AvahiServer *s, AvahiInterface *i) {
 282     AvahiEntry *e;
 283
 284     assert(s);
 285     assert(i);
 286
 287     if (!i->announcing)
 288         return;
 289
 290     for (e = s->entries; e; e = e->entries_next)
 291         if (!e->dead)
 292             new_announcement(s, i, e);
 293 }
 294
 295 static void announce_walk_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 296     AvahiEntry *e = userdata;
 297
 298     assert(m);
 299     assert(i);
 300     assert(e);
 301     assert(!e->dead);
 302
 303     new_announcement(m->server, i, e);
 304 }
 305
 306 void avahi_announce_entry(AvahiServer *s, AvahiEntry *e) {
 307     assert(s);
 308     assert(e);
 309     assert(!e->dead);
 310
 311     avahi_interface_monitor_walk(s->monitor, e->interface, e->protocol, announce_walk_callback, e);
 312 }
 313
 314 void avahi_announce_group(AvahiServer *s, AvahiSEntryGroup *g) {
 315     AvahiEntry *e;
 316
 317     assert(s);
 318     assert(g);
 319
 320     for (e = g->entries; e; e = e->by_group_next)
 321         if (!e->dead)
 322             avahi_announce_entry(s, e);
 323 }
 324
 325 int avahi_entry_is_registered(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 326     AvahiAnnouncement *a;
 327
 328     assert(s);
 329     assert(e);
 330     assert(i);
 331     assert(!e->dead);
 332
 333     if (!(a = avahi_get_announcement(s, e, i)))
 334         return 0;
 335
 336     return
 337         a->state == AVAHI_ANNOUNCING ||
 338         a->state == AVAHI_ESTABLISHED ||
 339         (a->state == AVAHI_WAITING && !(e->flags & AVAHI_ENTRY_UNIQUE));
 340 }
 341
 342 int avahi_entry_is_probing(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 343     AvahiAnnouncement *a;
 344
 345     assert(s);
 346     assert(e);
 347     assert(i);
 348     assert(!e->dead);
 349
 350     if (!(a = avahi_get_announcement(s, e, i)))
 351         return 0;
 352
 353 /*     avahi_log_debug("state: %i", a->state); */
 354
 355     return
 356         a->state == AVAHI_PROBING ||
 357         (a->state == AVAHI_WAITING && (e->flags & AVAHI_ENTRY_UNIQUE));
 358 }
 359
 360 void avahi_entry_return_to_initial_state(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 361     AvahiAnnouncement *a;
 362
 363     assert(s);
 364     assert(e);
 365     assert(i);
 366
 367     if (!(a = avahi_get_announcement(s, e, i)))
 368         return;
 369
 370     if (a->state == AVAHI_PROBING && a->entry->group)
 371         a->entry->group->n_probing--;
 372
 373     go_to_initial_state(a, 1);
 374 }
 375
 376 static AvahiRecord *make_goodbye_record(AvahiRecord *r) {
 377 /*     char *t; */
 378     AvahiRecord *g;
 379
 380     assert(r);
 381
 382 /*     avahi_log_debug("Preparing goodbye for record [%s]", t = avahi_record_to_string(r)); */
 383 /*     avahi_free(t); */
 384
 385     if (!(g = avahi_record_copy(r)))
 386         return NULL; /* OOM */
 387
 388     assert(g->ref == 1);
 389     g->ttl = 0;
 390
 391     return g;
 392 }
 393
 394 static void send_goodbye_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) {
 395     AvahiEntry *e = userdata;
 396     AvahiRecord *g;
 397
 398     assert(m);
 399     assert(i);
 400     assert(e);
 401     assert(!e->dead);
 402
 403     if (!avahi_interface_match(i, e->interface, e->protocol))
 404         return;
 405
 406     if (e->flags & AVAHI_ENTRY_NOANNOUNCE)
 407         return;
 408
 409     if (!avahi_entry_is_registered(m->server, e, i))
 410         return;
 411
 412     if (!(g = make_goodbye_record(e->record)))
 413         return; /* OOM */
 414
 415     avahi_interface_post_response(i, g, e->flags & AVAHI_ENTRY_UNIQUE, NULL, 1);
 416     avahi_record_unref(g);
 417 }
 418
 419 void avahi_goodbye_interface(AvahiServer *s, AvahiInterface *i, int goodbye) {
 420     assert(s);
 421     assert(i);
 422
 423 /*     avahi_log_debug("goodbye interface: %s.%u", i->hardware->name, i->protocol); */
 424
 425     if (goodbye && avahi_interface_relevant(i)) {
 426         AvahiEntry *e;
 427
 428         for (e = s->entries; e; e = e->entries_next)
 429             if (!e->dead)
 430                 send_goodbye_callback(s->monitor, i, e);
 431     }
 432
 433     while (i->announcements)
 434         remove_announcement(s, i->announcements);
 435
 436 /*     avahi_log_debug("goodbye interface done: %s.%u", i->hardware->name, i->protocol); */
 437 }
 438
 439 void avahi_goodbye_entry(AvahiServer *s, AvahiEntry *e, int goodbye) {
 440     assert(s);
 441     assert(e);
 442
 443 /*     avahi_log_debug("goodbye entry: %p", e); */
 444
 445     if (goodbye && !e->dead)
 446         avahi_interface_monitor_walk(s->monitor, 0, AF_UNSPEC, send_goodbye_callback, e);
 447
 448     while (e->announcements)
 449         remove_announcement(s, e->announcements);
 450
 451 /*     avahi_log_debug("goodbye entry done: %p", e); */
 452
 453 }
 454
 455 void avahi_goodbye_all(AvahiServer *s, int goodbye) {
 456     AvahiEntry *e;
 457
 458     assert(s);
 459
 460 /*     avahi_log_debug("goodbye all"); */
 461
 462     for (e = s->entries; e; e = e->entries_next)
 463         if (!e->dead)
 464             avahi_goodbye_entry(s, e, goodbye);
 465
 466 /*     avahi_log_debug("goodbye all done"); */
 467
 468 }
 469