1 /* PLEASE NOTE *
2 * This file demonstrates how to use Avahi's core API, this is
3 * the embeddable mDNS stack for embedded applications.
4 *
5 * End user applications should *not* use this API and should use
6 * the D-Bus or C APIs, please see
7 * client-browse-services.c and glib-integration.c
8 *
9 * I repeat, you probably do *not* want to use this example.
10 */
11
12 /***
13 This file is part of avahi.
14
15 avahi is free software; you can redistribute it and/or modify it
16 under the terms of the GNU Lesser General Public License as
17 published by the Free Software Foundation; either version 2.1 of the
18 License, or (at your option) any later version.
19
20 avahi is distributed in the hope that it will be useful, but WITHOUT
21 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
22 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
23 Public License for more details.
24
25 You should have received a copy of the GNU Lesser General Public
26 License along with avahi; if not, write to the Free Software
27 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
28 USA.
29 ***/
30
31 #ifdef HAVE_CONFIG_H
32 #include <config.h>
33 #endif
34
35 #include <stdio.h>
36 #include <assert.h>
37 #include <stdlib.h>
38 #include <time.h>
39
40 #include <avahi-core/core.h>
41 #include <avahi-core/lookup.h>
42 #include <avahi-common/simple-watch.h>
43 #include "avahi-common/avahi-malloc.h"
44 #include <avahi-common/error.h>
45
46 static AvahiSimplePoll *simple_poll = NULL;
47 static AvahiServer *server = NULL;
48
resolve_callback(AvahiSServiceResolver * r,AVAHI_GCC_UNUSED AvahiIfIndex interface,AVAHI_GCC_UNUSED AvahiProtocol protocol,AvahiResolverEvent event,const char * name,const char * type,const char * domain,const char * host_name,const AvahiAddress * address,uint16_t port,AvahiStringList * txt,AvahiLookupResultFlags flags,AVAHI_GCC_UNUSED void * userdata)49 static void resolve_callback(
50 AvahiSServiceResolver *r,
51 AVAHI_GCC_UNUSED AvahiIfIndex interface,
52 AVAHI_GCC_UNUSED AvahiProtocol protocol,
53 AvahiResolverEvent event,
54 const char *name,
55 const char *type,
56 const char *domain,
57 const char *host_name,
58 const AvahiAddress *address,
59 uint16_t port,
60 AvahiStringList *txt,
61 AvahiLookupResultFlags flags,
62 AVAHI_GCC_UNUSED void* userdata) {
63
64 assert(r);
65
66 /* Called whenever a service has been resolved successfully or timed out */
67
68 switch (event) {
69 case AVAHI_RESOLVER_FAILURE:
70 fprintf(stderr, "(Resolver) Failed to resolve service '%s' of type '%s' in domain '%s': %s\n", name, type, domain, avahi_strerror(avahi_server_errno(server)));
71 break;
72
73 case AVAHI_RESOLVER_FOUND: {
74 char a[AVAHI_ADDRESS_STR_MAX], *t;
75
76 fprintf(stderr, "(Resolver) Service '%s' of type '%s' in domain '%s':\n", name, type, domain);
77
78 avahi_address_snprint(a, sizeof(a), address);
79 t = avahi_string_list_to_string(txt);
80 fprintf(stderr,
81 "\t%s:%u (%s)\n"
82 "\tTXT=%s\n"
83 "\tcookie is %u\n"
84 "\tis_local: %i\n"
85 "\twide_area: %i\n"
86 "\tmulticast: %i\n"
87 "\tcached: %i\n",
88 host_name, port, a,
89 t,
90 avahi_string_list_get_service_cookie(txt),
91 !!(flags & AVAHI_LOOKUP_RESULT_LOCAL),
92 !!(flags & AVAHI_LOOKUP_RESULT_WIDE_AREA),
93 !!(flags & AVAHI_LOOKUP_RESULT_MULTICAST),
94 !!(flags & AVAHI_LOOKUP_RESULT_CACHED));
95 avahi_free(t);
96 }
97 }
98
99 avahi_s_service_resolver_free(r);
100 }
101
browse_callback(AvahiSServiceBrowser * b,AvahiIfIndex interface,AvahiProtocol protocol,AvahiBrowserEvent event,const char * name,const char * type,const char * domain,AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,void * userdata)102 static void browse_callback(
103 AvahiSServiceBrowser *b,
104 AvahiIfIndex interface,
105 AvahiProtocol protocol,
106 AvahiBrowserEvent event,
107 const char *name,
108 const char *type,
109 const char *domain,
110 AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
111 void* userdata) {
112
113 AvahiServer *s = userdata;
114 assert(b);
115
116 /* Called whenever a new services becomes available on the LAN or is removed from the LAN */
117
118 switch (event) {
119
120 case AVAHI_BROWSER_FAILURE:
121
122 fprintf(stderr, "(Browser) %s\n", avahi_strerror(avahi_server_errno(server)));
123 avahi_simple_poll_quit(simple_poll);
124 return;
125
126 case AVAHI_BROWSER_NEW:
127 fprintf(stderr, "(Browser) NEW: service '%s' of type '%s' in domain '%s'\n", name, type, domain);
128
129 /* We ignore the returned resolver object. In the callback
130 function we free it. If the server is terminated before
131 the callback function is called the server will free
132 the resolver for us. */
133
134 if (!(avahi_s_service_resolver_new(s, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, resolve_callback, s)))
135 fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_server_errno(s)));
136
137 break;
138
139 case AVAHI_BROWSER_REMOVE:
140 fprintf(stderr, "(Browser) REMOVE: service '%s' of type '%s' in domain '%s'\n", name, type, domain);
141 break;
142
143 case AVAHI_BROWSER_ALL_FOR_NOW:
144 case AVAHI_BROWSER_CACHE_EXHAUSTED:
145 fprintf(stderr, "(Browser) %s\n", event == AVAHI_BROWSER_CACHE_EXHAUSTED ? "CACHE_EXHAUSTED" : "ALL_FOR_NOW");
146 break;
147 }
148 }
149
main(AVAHI_GCC_UNUSED int argc,AVAHI_GCC_UNUSED char * argv[])150 int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char*argv[]) {
151 AvahiServerConfig config;
152 AvahiSServiceBrowser *sb = NULL;
153 int error;
154 int ret = 1;
155
156 /* Initialize the psuedo-RNG */
157 srand(time(NULL));
158
159 /* Allocate main loop object */
160 if (!(simple_poll = avahi_simple_poll_new())) {
161 fprintf(stderr, "Failed to create simple poll object.\n");
162 goto fail;
163 }
164
165 /* Do not publish any local records */
166 avahi_server_config_init(&config);
167 config.publish_hinfo = 0;
168 config.publish_addresses = 0;
169 config.publish_workstation = 0;
170 config.publish_domain = 0;
171
172 /* Set a unicast DNS server for wide area DNS-SD */
173 avahi_address_parse("192.168.50.1", AVAHI_PROTO_UNSPEC, &config.wide_area_servers[0]);
174 config.n_wide_area_servers = 1;
175 config.enable_wide_area = 1;
176
177 /* Allocate a new server */
178 server = avahi_server_new(avahi_simple_poll_get(simple_poll), &config, NULL, NULL, &error);
179
180 /* Free the configuration data */
181 avahi_server_config_free(&config);
182
183 /* Check wether creating the server object succeeded */
184 if (!server) {
185 fprintf(stderr, "Failed to create server: %s\n", avahi_strerror(error));
186 goto fail;
187 }
188
189 /* Create the service browser */
190 if (!(sb = avahi_s_service_browser_new(server, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, "_http._tcp", NULL, 0, browse_callback, server))) {
191 fprintf(stderr, "Failed to create service browser: %s\n", avahi_strerror(avahi_server_errno(server)));
192 goto fail;
193 }
194
195 /* Run the main loop */
196 avahi_simple_poll_loop(simple_poll);
197
198 ret = 0;
199
200 fail:
201
202 /* Cleanup things */
203 if (sb)
204 avahi_s_service_browser_free(sb);
205
206 if (server)
207 avahi_server_free(server);
208
209 if (simple_poll)
210 avahi_simple_poll_free(simple_poll);
211
212 return ret;
213 }
214