git.meshlink.io Git - catta/blob - avahi-core/resolve-address.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 <stdlib.h>
  27
  28 #include <avahi-common/timeval.h>
  29 #include <avahi-common/malloc.h>
  30 #include <avahi-common/error.h>
  31 #include <avahi-common/domain.h>
  32
  33 #include "browse.h"
  34
  35 #define TIMEOUT_MSEC 5000
  36
  37 struct AvahiSAddressResolver {
  38     AvahiServer *server;
  39     AvahiAddress address;
  40
  41     AvahiSRecordBrowser *record_browser;
  42
  43     AvahiSAddressResolverCallback callback;
  44     void* userdata;
  45
  46     AvahiRecord *ptr_record;
  47     AvahiIfIndex interface;
  48     AvahiProtocol protocol;
  49     AvahiLookupResultFlags flags;
  50
  51     int retry_with_multicast;
  52     AvahiKey *key;
  53
  54     AvahiTimeEvent *time_event;
  55
  56     AVAHI_LLIST_FIELDS(AvahiSAddressResolver, resolver);
  57 };
  58
  59 static void finish(AvahiSAddressResolver *r, AvahiResolverEvent event) {
  60     assert(r);
  61
  62     if (r->time_event) {
  63         avahi_time_event_free(r->time_event);
  64         r->time_event = NULL;
  65     }
  66
  67     switch (event) {
  68         case AVAHI_RESOLVER_FAILURE:
  69             r->callback(r, r->interface, r->protocol, event, &r->address, NULL, r->flags, r->userdata);
  70             break;
  71
  72         case AVAHI_RESOLVER_FOUND:
  73             assert(r->ptr_record);
  74             r->callback(r, r->interface, r->protocol, event, &r->address, r->ptr_record->data.ptr.name, r->flags, r->userdata);
  75             break;
  76     }
  77 }
  78
  79 static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
  80     AvahiSAddressResolver *r = userdata;
  81
  82     assert(e);
  83     assert(r);
  84
  85     avahi_server_set_errno(r->server, AVAHI_ERR_TIMEOUT);
  86     finish(r, AVAHI_RESOLVER_FAILURE);
  87 }
  88
  89 static void start_timeout(AvahiSAddressResolver *r) {
  90     struct timeval tv;
  91     assert(r);
  92
  93     if (r->time_event)
  94         return;
  95
  96     avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
  97     r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
  98 }
  99
 100 static void record_browser_callback(
 101     AvahiSRecordBrowser*rr,
 102     AvahiIfIndex interface,
 103     AvahiProtocol protocol,
 104     AvahiBrowserEvent event,
 105     AvahiRecord *record,
 106     AvahiLookupResultFlags flags,
 107     void* userdata) {
 108
 109     AvahiSAddressResolver *r = userdata;
 110
 111     assert(rr);
 112     assert(r);
 113
 114     switch (event) {
 115         case AVAHI_BROWSER_NEW:
 116             assert(record);
 117             assert(record->key->type == AVAHI_DNS_TYPE_PTR);
 118
 119             if (r->interface > 0 && interface != r->interface)
 120                 return;
 121
 122             if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
 123                 return;
 124
 125             if (r->interface <= 0)
 126                 r->interface = interface;
 127
 128             if (r->protocol == AVAHI_PROTO_UNSPEC)
 129                 r->protocol = protocol;
 130
 131             if (!r->ptr_record) {
 132                 r->ptr_record = avahi_record_ref(record);
 133                 r->flags = flags;
 134
 135                 finish(r, AVAHI_RESOLVER_FOUND);
 136             }
 137             break;
 138
 139         case AVAHI_BROWSER_REMOVE:
 140             assert(record);
 141             assert(record->key->type == AVAHI_DNS_TYPE_PTR);
 142
 143             if (r->ptr_record && avahi_record_equal_no_ttl(record, r->ptr_record)) {
 144                 avahi_record_unref(r->ptr_record);
 145                 r->ptr_record = NULL;
 146                 r->flags = flags;
 147
 148                 /** Look for a replacement */
 149                 avahi_s_record_browser_restart(r->record_browser);
 150                 start_timeout(r);
 151             }
 152
 153             break;
 154
 155         case AVAHI_BROWSER_CACHE_EXHAUSTED:
 156         case AVAHI_BROWSER_ALL_FOR_NOW:
 157             break;
 158
 159         case AVAHI_BROWSER_FAILURE:
 160
 161             if (r->retry_with_multicast) {
 162                 r->retry_with_multicast = 0;
 163
 164                 avahi_s_record_browser_free(r->record_browser);
 165                 r->record_browser = avahi_s_record_browser_new(r->server, r->interface, r->protocol, r->key, AVAHI_LOOKUP_USE_MULTICAST, record_browser_callback, r);
 166
 167                 if (r->record_browser) {
 168                     start_timeout(r);
 169                     break;
 170                 }
 171             }
 172
 173             r->flags = flags;
 174             finish(r, AVAHI_RESOLVER_FAILURE);
 175             break;
 176     }
 177 }
 178
 179 AvahiSAddressResolver *avahi_s_address_resolver_new(
 180     AvahiServer *server,
 181     AvahiIfIndex interface,
 182     AvahiProtocol protocol,
 183     const AvahiAddress *address,
 184     AvahiLookupFlags flags,
 185     AvahiSAddressResolverCallback callback,
 186     void* userdata) {
 187
 188     AvahiSAddressResolver *r;
 189     AvahiKey *k;
 190     char n[AVAHI_DOMAIN_NAME_MAX];
 191
 192     assert(server);
 193     assert(address);
 194     assert(callback);
 195
 196     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
 197     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
 198     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, address->proto == AVAHI_PROTO_INET || address->proto == AVAHI_PROTO_INET6, AVAHI_ERR_INVALID_PROTOCOL);
 199     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS);
 200
 201     avahi_reverse_lookup_name(address, n, sizeof(n));
 202
 203     if (!(k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_PTR))) {
 204         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 205         return NULL;
 206     }
 207
 208     if (!(r = avahi_new(AvahiSAddressResolver, 1))) {
 209         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 210         avahi_key_unref(k);
 211         return NULL;
 212     }
 213
 214     r->server = server;
 215     r->address = *address;
 216     r->callback = callback;
 217     r->userdata = userdata;
 218     r->ptr_record = NULL;
 219     r->interface = interface;
 220     r->protocol = protocol;
 221     r->flags = 0;
 222     r->retry_with_multicast = 0;
 223     r->key = k;
 224
 225     r->record_browser = NULL;
 226     AVAHI_LLIST_PREPEND(AvahiSAddressResolver, resolver, server->address_resolvers, r);
 227
 228     r->time_event = NULL;
 229
 230     if (!(flags & (AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_USE_WIDE_AREA))) {
 231
 232         if (!server->wide_area_lookup_engine || !avahi_wide_area_has_servers(server->wide_area_lookup_engine))
 233             flags |= AVAHI_LOOKUP_USE_MULTICAST;
 234         else {
 235             flags |= AVAHI_LOOKUP_USE_WIDE_AREA;
 236             r->retry_with_multicast = 1;
 237         }
 238     }
 239
 240     r->record_browser = avahi_s_record_browser_new(server, interface, protocol, k, flags, record_browser_callback, r);
 241
 242     if (!r->record_browser) {
 243         avahi_s_address_resolver_free(r);
 244         return NULL;
 245     }
 246
 247     start_timeout(r);
 248
 249     return r;
 250 }
 251
 252 void avahi_s_address_resolver_free(AvahiSAddressResolver *r) {
 253     assert(r);
 254
 255     AVAHI_LLIST_REMOVE(AvahiSAddressResolver, resolver, r->server->address_resolvers, r);
 256
 257     if (r->record_browser)
 258         avahi_s_record_browser_free(r->record_browser);
 259
 260     if (r->time_event)
 261         avahi_time_event_free(r->time_event);
 262
 263     if (r->ptr_record)
 264         avahi_record_unref(r->ptr_record);
 265
 266     if (r->key)
 267         avahi_key_unref(r->key);
 268
 269     avahi_free(r);
 270 }