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 <avahi-common/timeval.h>
  27 #include <avahi-common/malloc.h>
  28 #include <avahi-common/error.h>
  29
  30 #include "browse.h"
  31
  32 #define TIMEOUT_MSEC 5000
  33
  34 struct AvahiSAddressResolver {
  35     AvahiServer *server;
  36     AvahiAddress address;
  37
  38     AvahiSRecordBrowser *record_browser;
  39
  40     AvahiSAddressResolverCallback callback;
  41     void* userdata;
  42
  43     AvahiRecord *ptr_record;
  44     AvahiIfIndex interface;
  45     AvahiProtocol protocol;
  46     AvahiLookupResultFlags flags;
  47
  48     int retry_with_multicast;
  49     AvahiKey *key;
  50
  51     AvahiTimeEvent *time_event;
  52
  53     AVAHI_LLIST_FIELDS(AvahiSAddressResolver, resolver);
  54 };
  55
  56 static void finish(AvahiSAddressResolver *r, AvahiResolverEvent event) {
  57     assert(r);
  58
  59     if (r->time_event) {
  60         avahi_time_event_free(r->time_event);
  61         r->time_event = NULL;
  62     }
  63
  64     switch (event) {
  65         case AVAHI_RESOLVER_FAILURE:
  66             r->callback(r, r->interface, r->protocol, event, &r->address, NULL, r->flags, r->userdata);
  67             break;
  68
  69         case AVAHI_RESOLVER_FOUND:
  70             assert(r->ptr_record);
  71             r->callback(r, r->interface, r->protocol, event, &r->address, r->ptr_record->data.ptr.name, r->flags, r->userdata);
  72             break;
  73     }
  74 }
  75
  76 static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
  77     AvahiSAddressResolver *r = userdata;
  78
  79     assert(e);
  80     assert(r);
  81
  82     avahi_server_set_errno(r->server, AVAHI_ERR_TIMEOUT);
  83     finish(r, AVAHI_RESOLVER_FAILURE);
  84 }
  85
  86 static void start_timeout(AvahiSAddressResolver *r) {
  87     struct timeval tv;
  88     assert(r);
  89
  90     if (r->time_event)
  91         return;
  92
  93     avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
  94     r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
  95 }
  96
  97 static void record_browser_callback(
  98     AvahiSRecordBrowser*rr,
  99     AvahiIfIndex interface,
 100     AvahiProtocol protocol,
 101     AvahiBrowserEvent event,
 102     AvahiRecord *record,
 103     AvahiLookupResultFlags flags,
 104     void* userdata) {
 105
 106     AvahiSAddressResolver *r = userdata;
 107
 108     assert(rr);
 109     assert(r);
 110
 111     switch (event) {
 112         case AVAHI_BROWSER_NEW:
 113             assert(record);
 114             assert(record->key->type == AVAHI_DNS_TYPE_PTR);
 115
 116             if (r->interface > 0 && interface != r->interface)
 117                 return;
 118
 119             if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
 120                 return;
 121
 122             if (r->interface <= 0)
 123                 r->interface = interface;
 124
 125             if (r->protocol == AVAHI_PROTO_UNSPEC)
 126                 r->protocol = protocol;
 127
 128             if (!r->ptr_record) {
 129                 r->ptr_record = avahi_record_ref(record);
 130                 r->flags = flags;
 131
 132                 finish(r, AVAHI_RESOLVER_FOUND);
 133             }
 134             break;
 135
 136         case AVAHI_BROWSER_REMOVE:
 137             assert(record);
 138             assert(record->key->type == AVAHI_DNS_TYPE_PTR);
 139
 140             if (r->ptr_record && avahi_record_equal_no_ttl(record, r->ptr_record)) {
 141                 avahi_record_unref(r->ptr_record);
 142                 r->ptr_record = NULL;
 143                 r->flags = flags;
 144
 145                 /** Look for a replacement */
 146                 avahi_s_record_browser_restart(r->record_browser);
 147                 start_timeout(r);
 148             }
 149
 150             break;
 151
 152         case AVAHI_BROWSER_CACHE_EXHAUSTED:
 153         case AVAHI_BROWSER_ALL_FOR_NOW:
 154             break;
 155
 156         case AVAHI_BROWSER_FAILURE:
 157
 158             if (r->retry_with_multicast) {
 159                 r->retry_with_multicast = 0;
 160
 161                 avahi_s_record_browser_free(r->record_browser);
 162                 r->record_browser = avahi_s_record_browser_new(r->server, r->interface, r->protocol, r->key, AVAHI_LOOKUP_USE_MULTICAST, record_browser_callback, r);
 163
 164                 if (r->record_browser) {
 165                     start_timeout(r);
 166                     break;
 167                 }
 168             }
 169
 170             r->flags = flags;
 171             finish(r, AVAHI_RESOLVER_FAILURE);
 172             break;
 173     }
 174 }
 175
 176 AvahiSAddressResolver *avahi_s_address_resolver_new(
 177     AvahiServer *server,
 178     AvahiIfIndex interface,
 179     AvahiProtocol protocol,
 180     const AvahiAddress *address,
 181     AvahiLookupFlags flags,
 182     AvahiSAddressResolverCallback callback,
 183     void* userdata) {
 184
 185     AvahiSAddressResolver *r;
 186     AvahiKey *k;
 187     char *n;
 188
 189     assert(server);
 190     assert(address);
 191     assert(callback);
 192
 193     assert(address->proto == AVAHI_PROTO_INET || address->proto == AVAHI_PROTO_INET6);
 194
 195     if (!AVAHI_IF_VALID(interface)) {
 196         avahi_server_set_errno(server, AVAHI_ERR_INVALID_INTERFACE);
 197         return NULL;
 198     }
 199
 200     if (!AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST)) {
 201         avahi_server_set_errno(server, AVAHI_ERR_INVALID_FLAGS);
 202         return NULL;
 203     }
 204
 205     if (address->proto == AVAHI_PROTO_INET)
 206         n = avahi_reverse_lookup_name_ipv4(&address->data.ipv4);
 207     else
 208         n = avahi_reverse_lookup_name_ipv6(&address->data.ipv6);
 209
 210     if (!n) {
 211         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 212         return NULL;
 213     }
 214
 215     k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_PTR);
 216     avahi_free(n);
 217
 218     if (!k) {
 219         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 220         return NULL;
 221     }
 222
 223     if (!(r = avahi_new(AvahiSAddressResolver, 1))) {
 224         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 225         avahi_key_unref(k);
 226         return NULL;
 227     }
 228
 229     r->server = server;
 230     r->address = *address;
 231     r->callback = callback;
 232     r->userdata = userdata;
 233     r->ptr_record = NULL;
 234     r->interface = interface;
 235     r->protocol = protocol;
 236     r->flags = 0;
 237     r->retry_with_multicast = 0;
 238     r->key = k;
 239
 240     r->record_browser = NULL;
 241     AVAHI_LLIST_PREPEND(AvahiSAddressResolver, resolver, server->address_resolvers, r);
 242
 243     r->time_event = NULL;
 244
 245     if (!(flags & (AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_USE_WIDE_AREA))) {
 246
 247         if (!server->wide_area_lookup_engine || !avahi_wide_area_has_servers(server->wide_area_lookup_engine))
 248             flags |= AVAHI_LOOKUP_USE_MULTICAST;
 249         else {
 250             flags |= AVAHI_LOOKUP_USE_WIDE_AREA;
 251             r->retry_with_multicast = 1;
 252         }
 253     }
 254
 255     r->record_browser = avahi_s_record_browser_new(server, interface, protocol, k, flags, record_browser_callback, r);
 256
 257     if (!r->record_browser) {
 258         avahi_s_address_resolver_free(r);
 259         return NULL;
 260     }
 261
 262     start_timeout(r);
 263
 264     return r;
 265 }
 266
 267 void avahi_s_address_resolver_free(AvahiSAddressResolver *r) {
 268     assert(r);
 269
 270     AVAHI_LLIST_REMOVE(AvahiSAddressResolver, resolver, r->server->address_resolvers, r);
 271
 272     if (r->record_browser)
 273         avahi_s_record_browser_free(r->record_browser);
 274
 275     if (r->time_event)
 276         avahi_time_event_free(r->time_event);
 277
 278     if (r->ptr_record)
 279         avahi_record_unref(r->ptr_record);
 280
 281     if (r->key)
 282         avahi_key_unref(r->key);
 283
 284     avahi_free(r);
 285 }