announce.c

   1 /*
   2  * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <sys/types.h>
  15
  16 #include <stdio.h>
  17
  18 #include <libubox/uloop.h>
  19
  20 #include "cache.h"
  21 #include "dns.h"
  22 #include "util.h"
  23 #include "service.h"
  24 #include "announce.h"
  25 #include "interface.h"
  26
  27 #define TTL_TIMEOUT     75
  28
  29 enum {
  30         STATE_PROBE1 = 0,
  31         STATE_PROBE2,
  32         STATE_PROBE3,
  33         STATE_PROBE_WAIT,
  34         STATE_PROBE_END,
  35         STATE_ANNOUNCE,
  36 };
  37
  38 int announce_ttl = 75 * 60;
  39
  40 static void
  41 announce_timer(struct uloop_timeout *timeout)
  42 {
  43         struct interface *iface = container_of(timeout, struct interface, announce_timer);
  44
  45         switch (iface->announce_state) {
  46                 case STATE_PROBE1:
  47                 case STATE_PROBE2:
  48                 case STATE_PROBE3:
  49                         dns_send_question(iface, mdns_hostname_local, TYPE_ANY, 1);
  50                         uloop_timeout_set(timeout, 250);
  51                         iface->announce_state++;
  52                         break;
  53
  54                 case STATE_PROBE_WAIT:
  55                         uloop_timeout_set(timeout, 500);
  56                         iface->announce_state++;
  57                         break;
  58
  59                 case STATE_PROBE_END:
  60                         if (cache_host_is_known(mdns_hostname_local)) {
  61                                 fprintf(stderr, "the host %s already exists. stopping announce service\n", mdns_hostname_local);
  62                                 return;
  63                         }
  64                         iface->announce_state++;
  65                         /* Fall through */
  66
  67                 case STATE_ANNOUNCE:
  68                         dns_reply_a(iface, announce_ttl);
  69                         service_announce(iface, announce_ttl);
  70                         uloop_timeout_set(timeout, announce_ttl * 800);
  71                         break;
  72         }
  73 }
  74
  75 void
  76 announce_init(struct interface *iface)
  77 {
  78         iface->announce_state = STATE_PROBE1;
  79         iface->announce_timer.cb = announce_timer;
  80         uloop_timeout_set(&iface->announce_timer, 100);
  81 }
  82
  83 void
  84 announce_free(struct interface *iface)
  85 {
  86         uloop_timeout_cancel(&iface->announce_timer);
  87 }