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         char host[256];
  45
  46         snprintf(host, sizeof(host), "%s.local", hostname);
  47
  48         switch (iface->announce_state) {
  49                 case STATE_PROBE1:
  50                 case STATE_PROBE2:
  51                 case STATE_PROBE3:
  52                         dns_send_question(iface, host, TYPE_ANY);
  53                         uloop_timeout_set(timeout, 250);
  54                         iface->announce_state++;
  55                         break;
  56
  57                 case STATE_PROBE_WAIT:
  58                         uloop_timeout_set(timeout, 500);
  59                         iface->announce_state++;
  60                         break;
  61
  62                 case STATE_PROBE_END:
  63                         if (cache_host_is_known(host)) {
  64                                 fprintf(stderr, "the host %s already exists. stopping announce service\n", host);
  65                                 return;
  66                         }
  67                         iface->announce_state++;
  68
  69                 case STATE_ANNOUNCE:
  70                         service_announce(iface);
  71                         uloop_timeout_set(timeout, announce_ttl * 800);
  72                         break;
  73         }
  74 }
  75
  76 void
  77 announce_init(struct interface *iface)
  78 {
  79         iface->announce_state = STATE_PROBE1;
  80         iface->announce_timer.cb = announce_timer;
  81         uloop_timeout_set(&iface->announce_timer, 100);
  82 }
  83
  84 void
  85 announce_free(struct interface *iface)
  86 {
  87         uloop_timeout_cancel(&iface->announce_timer);
  88 }