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 "announce.h"
  28
  29 #define AVAHI_ANNOUNCEMENT_JITTER_MSEC 250
  30 #define AVAHI_PROBE_JITTER_MSEC 250
  31 #define AVAHI_PROBE_INTERVAL_MSEC 250
  32
  33 static void remove_announcement(AvahiServer *s, AvahiAnnouncement *a) {
  34     g_assert(s);
  35     g_assert(a);
  36
  37     if (a->time_event)
  38         avahi_time_event_queue_remove(s->time_event_queue, a->time_event);
  39
  40     AVAHI_LLIST_REMOVE(AvahiAnnouncement, by_interface, a->interface->announcements, a);
  41     AVAHI_LLIST_REMOVE(AvahiAnnouncement, by_entry, a->entry->announcements, a);
  42
  43     g_free(a);
  44 }
  45
  46 static void elapse_announce(AvahiTimeEvent *e, void *userdata);
  47
  48 static void set_timeout(AvahiAnnouncement *a, const struct timeval *tv) {
  49     g_assert(a);
  50
  51     if (!tv) {
  52         if (a->time_event) {
  53             avahi_time_event_queue_remove(a->server->time_event_queue, a->time_event);
  54             a->time_event = NULL;
  55         }
  56     } else {
  57
  58         if (a->time_event)
  59             avahi_time_event_queue_update(a->server->time_event_queue, a->time_event, tv);
  60         else
  61             a->time_event = avahi_time_event_queue_add(a->server->time_event_queue, tv, elapse_announce, a);
  62     }
  63 }
  64
  65 static void next_state(AvahiAnnouncement *a);
  66
  67 void avahi_entry_group_check_probed(AvahiEntryGroup *g, gboolean immediately) {
  68     AvahiEntry *e;
  69     g_assert(g);
  70     g_assert(!g->dead);
  71
  72     /* Check whether all group members have been probed */
  73
  74     if (g->state != AVAHI_ENTRY_GROUP_REGISTERING || g->n_probing > 0)
  75         return;
  76
  77     avahi_entry_group_change_state(g, AVAHI_ENTRY_GROUP_ESTABLISHED);
  78
  79     if (g->dead)
  80         return;
  81
  82     for (e = g->entries; e; e = e->entries_next) {
  83         AvahiAnnouncement *a;
  84
  85         for (a = e->announcements; a; a = a->by_entry_next) {
  86
  87             if (a->state != AVAHI_WAITING)
  88                 continue;
  89
  90             a->state = AVAHI_ANNOUNCING;
  91
  92             if (immediately) {
  93                 /* Shortcut */
  94
  95                 a->n_iteration = 1;
  96                 next_state(a);
  97             } else {
  98                 struct timeval tv;
  99                 a->n_iteration = 0;
 100                 avahi_elapse_time(&tv, 0, AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 101                 set_timeout(a, &tv);
 102             }
 103         }
 104     }
 105 }
 106
 107 static void next_state(AvahiAnnouncement *a) {
 108     g_assert(a);
 109
 110 /*     avahi_log_debug("%i -- %u", a->state, a->n_iteration);   */
 111
 112     if (a->state == AVAHI_WAITING) {
 113
 114         g_assert(a->entry->group);
 115
 116         avahi_entry_group_check_probed(a->entry->group, TRUE);
 117
 118     } else if (a->state == AVAHI_PROBING) {
 119
 120         if (a->n_iteration >= 4) {
 121             /* Probing done */
 122
 123 /*             gchar *t; */
 124
 125 /*             avahi_log_debug("Enough probes for record [%s]", t = avahi_record_to_string(a->entry->record)); */
 126 /*             g_free(t); */
 127
 128             if (a->entry->group) {
 129                 g_assert(a->entry->group->n_probing);
 130                 a->entry->group->n_probing--;
 131             }
 132
 133             if (a->entry->group && a->entry->group->state == AVAHI_ENTRY_GROUP_REGISTERING)
 134                 a->state = AVAHI_WAITING;
 135             else {
 136                 a->state = AVAHI_ANNOUNCING;
 137                 a->n_iteration = 1;
 138             }
 139
 140             set_timeout(a, NULL);
 141             next_state(a);
 142         } else {
 143             struct timeval tv;
 144
 145             avahi_interface_post_probe(a->interface, a->entry->record, FALSE);
 146
 147             avahi_elapse_time(&tv, AVAHI_PROBE_INTERVAL_MSEC, 0);
 148             set_timeout(a, &tv);
 149
 150             a->n_iteration++;
 151         }
 152
 153     } else if (a->state == AVAHI_ANNOUNCING) {
 154
 155         if (a->entry->flags & AVAHI_ENTRY_UNIQUE)
 156             /* Send the whole rrset at once */
 157             avahi_server_prepare_matching_responses(a->server, a->interface, a->entry->record->key, FALSE);
 158         else
 159             avahi_server_prepare_response(a->server, a->interface, a->entry, FALSE, FALSE);
 160
 161         avahi_server_generate_response(a->server, a->interface, NULL, NULL, 0, FALSE, FALSE);
 162
 163         if (++a->n_iteration >= 4) {
 164 /*             gchar *t; */
 165             /* Announcing done */
 166
 167 /*             avahi_log_debug("Enough announcements for record [%s]", t = avahi_record_to_string(a->entry->record)); */
 168 /*             g_free(t); */
 169
 170             a->state = AVAHI_ESTABLISHED;
 171
 172             set_timeout(a, NULL);
 173         } else {
 174             struct timeval tv;
 175             avahi_elapse_time(&tv, a->sec_delay*1000, AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 176
 177             if (a->n_iteration < 10)
 178                 a->sec_delay *= 2;
 179
 180             set_timeout(a, &tv);
 181         }
 182     }
 183 }
 184
 185 static void elapse_announce(AvahiTimeEvent *e, void *userdata) {
 186     g_assert(e);
 187
 188     next_state(userdata);
 189 }
 190
 191 AvahiAnnouncement *avahi_get_announcement(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 192     AvahiAnnouncement *a;
 193
 194     g_assert(s);
 195     g_assert(e);
 196     g_assert(i);
 197
 198     for (a = e->announcements; a; a = a->by_entry_next)
 199         if (a->interface == i)
 200             return a;
 201
 202     return NULL;
 203 }
 204
 205 static void go_to_initial_state(AvahiAnnouncement *a, gboolean immediately) {
 206     AvahiEntry *e;
 207     struct timeval tv;
 208
 209     g_assert(a);
 210     e = a->entry;
 211
 212     if ((e->flags & AVAHI_ENTRY_UNIQUE) && !(e->flags & AVAHI_ENTRY_NOPROBE))
 213         a->state = AVAHI_PROBING;
 214     else if (!(e->flags & AVAHI_ENTRY_NOANNOUNCE)) {
 215
 216         if (!e->group || e->group->state == AVAHI_ENTRY_GROUP_ESTABLISHED)
 217             a->state = AVAHI_ANNOUNCING;
 218         else
 219             a->state = AVAHI_WAITING;
 220
 221     } else
 222         a->state = AVAHI_ESTABLISHED;
 223
 224     a->n_iteration = 1;
 225     a->sec_delay = 1;
 226
 227     if (a->state == AVAHI_PROBING && e->group)
 228         e->group->n_probing++;
 229
 230     if (a->state == AVAHI_PROBING) {
 231         avahi_elapse_time(&tv, 0, immediately ? 0 : AVAHI_PROBE_JITTER_MSEC);
 232         set_timeout(a, &tv);
 233     } else if (a->state == AVAHI_ANNOUNCING) {
 234         avahi_elapse_time(&tv, 0, immediately ? 0 : AVAHI_ANNOUNCEMENT_JITTER_MSEC);
 235         set_timeout(a, &tv);
 236     } else
 237         set_timeout(a, NULL);
 238 }
 239
 240 static void new_announcement(AvahiServer *s, AvahiInterface *i, AvahiEntry *e) {
 241     AvahiAnnouncement *a;
 242 /*     gchar *t;  */
 243
 244     g_assert(s);
 245     g_assert(i);
 246     g_assert(e);
 247     g_assert(!e->dead);
 248
 249 /*     avahi_log_debug("NEW ANNOUNCEMENT: %s.%i [%s]", i->hardware->name, i->protocol, t = avahi_record_to_string(e->record)); */
 250 /*     g_free(t); */
 251
 252     if (!avahi_interface_match(i, e->interface, e->protocol) || !i->announcing || !avahi_entry_commited(e))
 253         return;
 254
 255     /* We don't want duplicate announcements */
 256     if (avahi_get_announcement(s, e, i))
 257         return;
 258
 259     a = g_new(AvahiAnnouncement, 1);
 260     a->server = s;
 261     a->interface = i;
 262     a->entry = e;
 263     a->time_event = NULL;
 264
 265     AVAHI_LLIST_PREPEND(AvahiAnnouncement, by_interface, i->announcements, a);
 266     AVAHI_LLIST_PREPEND(AvahiAnnouncement, by_entry, e->announcements, a);
 267
 268     go_to_initial_state(a, FALSE);
 269
 270 /*     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); */
 271 /*     g_free(t); */
 272 }
 273
 274 void avahi_announce_interface(AvahiServer *s, AvahiInterface *i) {
 275     AvahiEntry *e;
 276
 277     g_assert(s);
 278     g_assert(i);
 279
 280     if (!i->announcing)
 281         return;
 282
 283     for (e = s->entries; e; e = e->entries_next)
 284         if (!e->dead)
 285             new_announcement(s, i, e);
 286 }
 287
 288 static void announce_walk_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, gpointer userdata) {
 289     AvahiEntry *e = userdata;
 290
 291     g_assert(m);
 292     g_assert(i);
 293     g_assert(e);
 294     g_assert(!e->dead);
 295
 296     new_announcement(m->server, i, e);
 297 }
 298
 299 void avahi_announce_entry(AvahiServer *s, AvahiEntry *e) {
 300     g_assert(s);
 301     g_assert(e);
 302     g_assert(!e->dead);
 303
 304     avahi_interface_monitor_walk(s->monitor, e->interface, e->protocol, announce_walk_callback, e);
 305 }
 306
 307 void avahi_announce_group(AvahiServer *s, AvahiEntryGroup *g) {
 308     AvahiEntry *e;
 309
 310     g_assert(s);
 311     g_assert(g);
 312
 313     for (e = g->entries; e; e = e->by_group_next)
 314         if (!e->dead)
 315             avahi_announce_entry(s, e);
 316 }
 317
 318 gboolean avahi_entry_registered(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 319     AvahiAnnouncement *a;
 320
 321     g_assert(s);
 322     g_assert(e);
 323     g_assert(i);
 324     g_assert(!e->dead);
 325
 326     if (!(a = avahi_get_announcement(s, e, i)))
 327         return FALSE;
 328
 329     return
 330         a->state == AVAHI_ANNOUNCING ||
 331         a->state == AVAHI_ESTABLISHED ||
 332         (a->state == AVAHI_WAITING && !(e->flags & AVAHI_ENTRY_UNIQUE));
 333 }
 334
 335 gboolean avahi_entry_probing(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 336     AvahiAnnouncement *a;
 337
 338     g_assert(s);
 339     g_assert(e);
 340     g_assert(i);
 341     g_assert(!e->dead);
 342
 343     if (!(a = avahi_get_announcement(s, e, i)))
 344         return FALSE;
 345
 346 /*     avahi_log_debug("state: %i", a->state); */
 347
 348     return
 349         a->state == AVAHI_PROBING ||
 350         (a->state == AVAHI_WAITING && (e->flags & AVAHI_ENTRY_UNIQUE));
 351 }
 352
 353 void avahi_entry_return_to_initial_state(AvahiServer *s, AvahiEntry *e, AvahiInterface *i) {
 354     AvahiAnnouncement *a;
 355
 356     g_assert(s);
 357     g_assert(e);
 358     g_assert(i);
 359
 360     if (!(a = avahi_get_announcement(s, e, i)))
 361         return;
 362
 363     if (a->state == AVAHI_PROBING && a->entry->group)
 364         a->entry->group->n_probing--;
 365
 366     go_to_initial_state(a, TRUE);
 367 }
 368
 369 static AvahiRecord *make_goodbye_record(AvahiRecord *r) {
 370 /*     gchar *t; */
 371     AvahiRecord *g;
 372
 373     g_assert(r);
 374
 375 /*     avahi_log_debug("Preparing goodbye for record [%s]", t = avahi_record_to_string(r)); */
 376 /*     g_free(t); */
 377
 378     g = avahi_record_copy(r);
 379     g_assert(g->ref == 1);
 380     g->ttl = 0;
 381
 382     return g;
 383 }
 384
 385 static void send_goodbye_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, gpointer userdata) {
 386     AvahiEntry *e = userdata;
 387     AvahiRecord *g;
 388
 389     g_assert(m);
 390     g_assert(i);
 391     g_assert(e);
 392     g_assert(!e->dead);
 393
 394     if (!avahi_interface_match(i, e->interface, e->protocol))
 395         return;
 396
 397     if (e->flags & AVAHI_ENTRY_NOANNOUNCE)
 398         return;
 399
 400     if (!avahi_entry_registered(m->server, e, i))
 401         return;
 402
 403     g = make_goodbye_record(e->record);
 404     avahi_interface_post_response(i, g, e->flags & AVAHI_ENTRY_UNIQUE, NULL, TRUE);
 405     avahi_record_unref(g);
 406 }
 407
 408 void avahi_goodbye_interface(AvahiServer *s, AvahiInterface *i, gboolean goodbye) {
 409     g_assert(s);
 410     g_assert(i);
 411
 412 /*     avahi_log_debug("goodbye interface: %s.%u", i->hardware->name, i->protocol); */
 413
 414     if (goodbye && avahi_interface_relevant(i)) {
 415         AvahiEntry *e;
 416
 417         for (e = s->entries; e; e = e->entries_next)
 418             if (!e->dead)
 419                 send_goodbye_callback(s->monitor, i, e);
 420     }
 421
 422     while (i->announcements)
 423         remove_announcement(s, i->announcements);
 424
 425 /*     avahi_log_debug("goodbye interface done: %s.%u", i->hardware->name, i->protocol); */
 426
 427 }
 428
 429 void avahi_goodbye_entry(AvahiServer *s, AvahiEntry *e, gboolean goodbye) {
 430     g_assert(s);
 431     g_assert(e);
 432
 433 /*     avahi_log_debug("goodbye entry: %p", e); */
 434
 435     if (goodbye && !e->dead)
 436         avahi_interface_monitor_walk(s->monitor, 0, AF_UNSPEC, send_goodbye_callback, e);
 437
 438     while (e->announcements)
 439         remove_announcement(s, e->announcements);
 440
 441 /*     avahi_log_debug("goodbye entry done: %p", e); */
 442
 443 }
 444
 445 void avahi_goodbye_all(AvahiServer *s, gboolean goodbye) {
 446     AvahiEntry *e;
 447
 448     g_assert(s);
 449
 450 /*     avahi_log_debug("goodbye all"); */
 451
 452     for (e = s->entries; e; e = e->entries_next)
 453         if (!e->dead)
 454             avahi_goodbye_entry(s, e, goodbye);
 455
 456 /*     avahi_log_debug("goodbye all done"); */
 457
 458 }
 459