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 static struct uloop_timeout announce;
  39 struct uloop_fd *announce_fd;
  40 static int announce_state;
  41 int announce_ttl = 75 * 60;
  42
  43 static void
  44 announce_timer(struct uloop_timeout *timeout)
  45 {
  46         char host[256];
  47
  48         snprintf(host, sizeof(host), "%s.local", hostname);
  49
  50         switch (announce_state) {
  51                 case STATE_PROBE1:
  52                 case STATE_PROBE2:
  53                 case STATE_PROBE3:
  54                         dns_send_question(cur_iface, host, TYPE_ANY);
  55                         uloop_timeout_set(timeout, 250);
  56                         announce_state++;
  57                         break;
  58
  59                 case STATE_PROBE_WAIT:
  60                         uloop_timeout_set(timeout, 500);
  61                         announce_state++;
  62                         break;
  63
  64                 case STATE_PROBE_END:
  65                         if (cache_host_is_known(host)) {
  66                                 fprintf(stderr, "the host %s already exists. stopping announce service\n", host);
  67                                 return;
  68                         }
  69                         announce_state++;
  70
  71                 case STATE_ANNOUNCE:
  72                         service_announce(announce_fd);
  73                         uloop_timeout_set(timeout, announce_ttl * 800);
  74                         break;
  75         }
  76 }
  77
  78 void
  79 announce_init(struct uloop_fd *u)
  80 {
  81         announce_state = STATE_PROBE1;
  82         announce.cb = announce_timer;
  83         announce_fd = u;
  84         uloop_timeout_set(&announce, 100);
  85 }