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/malloc.h>
44#include <avahi-common/error.h>
45
46static AvahiSimplePoll *simple_poll = NULL;
47static AvahiServer *server = NULL;
48
49static 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
102static 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
150int 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
200fail:
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