aboutsummaryrefslogtreecommitdiffstats
path: root/src/ZeroconfAvahi.cxx
blob: 8fa745a69808b3b8c95fac56fba6065d36356679 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
/*
 * Copyright (C) 2003-2013 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "ZeroconfAvahi.hxx"
#include "ZeroconfInternal.hxx"
#include "Listen.hxx"
#include "mpd_error.h"

#include <glib.h>

#include <avahi-client/client.h>
#include <avahi-client/publish.h>

#include <avahi-common/alternative.h>
#include <avahi-common/domain.h>
#include <avahi-common/malloc.h>
#include <avahi-common/error.h>

#include <avahi-glib/glib-watch.h>

#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "avahi"

static char *avahiName;
static int avahiRunning;
static AvahiGLibPoll *avahi_glib_poll;
static const AvahiPoll *avahi_poll;
static AvahiClient *avahiClient;
static AvahiEntryGroup *avahiGroup;

static void avahiRegisterService(AvahiClient * c);

/* Callback when the EntryGroup changes state */
static void avahiGroupCallback(AvahiEntryGroup * g,
			       AvahiEntryGroupState state,
			       G_GNUC_UNUSED void *userdata)
{
	char *n;
	assert(g);

	g_debug("Service group changed to state %d", state);

	switch (state) {
	case AVAHI_ENTRY_GROUP_ESTABLISHED:
		/* The entry group has been established successfully */
		g_message("Service '%s' successfully established.",
			  avahiName);
		break;

	case AVAHI_ENTRY_GROUP_COLLISION:
		/* A service name collision happened. Let's pick a new name */
		n = avahi_alternative_service_name(avahiName);
		avahi_free(avahiName);
		avahiName = n;

		g_message("Service name collision, renaming service to '%s'",
			  avahiName);

		/* And recreate the services */
		avahiRegisterService(avahi_entry_group_get_client(g));
		break;

	case AVAHI_ENTRY_GROUP_FAILURE:
		g_warning("Entry group failure: %s",
			  avahi_strerror(avahi_client_errno
					 (avahi_entry_group_get_client(g))));
		/* Some kind of failure happened while we were registering our services */
		avahiRunning = 0;
		break;

	case AVAHI_ENTRY_GROUP_UNCOMMITED:
		g_debug("Service group is UNCOMMITED");
		break;
	case AVAHI_ENTRY_GROUP_REGISTERING:
		g_debug("Service group is REGISTERING");
	}
}

/* Registers a new service with avahi */
static void avahiRegisterService(AvahiClient * c)
{
	int ret;
	assert(c);
	g_debug("Registering service %s/%s", SERVICE_TYPE, avahiName);

	/* If this is the first time we're called,
	 * let's create a new entry group */
	if (!avahiGroup) {
		avahiGroup = avahi_entry_group_new(c, avahiGroupCallback, NULL);
		if (!avahiGroup) {
			g_warning("Failed to create avahi EntryGroup: %s",
				  avahi_strerror(avahi_client_errno(c)));
			goto fail;
		}
	}

	/* Add the service */
	/* TODO: This currently binds to ALL interfaces.
	 *       We could maybe add a service per actual bound interface,
	 *       if that's better. */
	ret = avahi_entry_group_add_service(avahiGroup,
					    AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
					    AvahiPublishFlags(0),
					    avahiName, SERVICE_TYPE, NULL,
					    NULL, listen_port, NULL);
	if (ret < 0) {
		g_warning("Failed to add service %s: %s", SERVICE_TYPE,
			  avahi_strerror(ret));
		goto fail;
	}

	/* Tell the server to register the service group */
	ret = avahi_entry_group_commit(avahiGroup);
	if (ret < 0) {
		g_warning("Failed to commit service group: %s",
			  avahi_strerror(ret));
		goto fail;
	}
	return;

fail:
	avahiRunning = 0;
}

/* Callback when avahi changes state */
static void avahiClientCallback(AvahiClient * c, AvahiClientState state,
				G_GNUC_UNUSED void *userdata)
{
	int reason;
	assert(c);

	/* Called whenever the client or server state changes */
	g_debug("Client changed to state %d", state);

	switch (state) {
	case AVAHI_CLIENT_S_RUNNING:
		g_debug("Client is RUNNING");

		/* The server has startup successfully and registered its host
		 * name on the network, so it's time to create our services */
		if (!avahiGroup)
			avahiRegisterService(c);
		break;

	case AVAHI_CLIENT_FAILURE:
		reason = avahi_client_errno(c);
		if (reason == AVAHI_ERR_DISCONNECTED) {
			g_message("Client Disconnected, will reconnect shortly");
			if (avahiGroup) {
				avahi_entry_group_free(avahiGroup);
				avahiGroup = NULL;
			}
			if (avahiClient)
				avahi_client_free(avahiClient);
			avahiClient =
			    avahi_client_new(avahi_poll,
					     AVAHI_CLIENT_NO_FAIL,
					     avahiClientCallback, NULL,
					     &reason);
			if (!avahiClient) {
				g_warning("Could not reconnect: %s",
					  avahi_strerror(reason));
				avahiRunning = 0;
			}
		} else {
			g_warning("Client failure: %s (terminal)",
				  avahi_strerror(reason));
			avahiRunning = 0;
		}
		break;

	case AVAHI_CLIENT_S_COLLISION:
		g_debug("Client is COLLISION");
		/* Let's drop our registered services. When the server is back
		 * in AVAHI_SERVER_RUNNING state we will register them
		 * again with the new host name. */
		if (avahiGroup) {
			g_debug("Resetting group");
			avahi_entry_group_reset(avahiGroup);
		}

	case AVAHI_CLIENT_S_REGISTERING:
		g_debug("Client is REGISTERING");
		/* The server records are now being established. This
		 * might be caused by a host name change. We need to wait
		 * for our own records to register until the host name is
		 * properly esatblished. */

		if (avahiGroup) {
			g_debug("Resetting group");
			avahi_entry_group_reset(avahiGroup);
		}

		break;

	case AVAHI_CLIENT_CONNECTING:
		g_debug("Client is CONNECTING");
	}
}

void
AvahiInit(const char *serviceName)
{
	int error;
	g_debug("Initializing interface");

	if (!avahi_is_valid_service_name(serviceName))
		MPD_ERROR("Invalid zeroconf_name \"%s\"", serviceName);

	avahiName = avahi_strdup(serviceName);

	avahiRunning = 1;

	avahi_glib_poll = avahi_glib_poll_new(NULL, G_PRIORITY_DEFAULT);
	avahi_poll = avahi_glib_poll_get(avahi_glib_poll);

	avahiClient = avahi_client_new(avahi_poll, AVAHI_CLIENT_NO_FAIL,
				       avahiClientCallback, NULL, &error);

	if (!avahiClient) {
		g_warning("Failed to create client: %s",
			  avahi_strerror(error));
		AvahiDeinit();
	}
}

void
AvahiDeinit(void)
{
	g_debug("Shutting down interface");

	if (avahiGroup) {
		avahi_entry_group_free(avahiGroup);
		avahiGroup = NULL;
	}

	if (avahiClient) {
		avahi_client_free(avahiClient);
		avahiClient = NULL;
	}

	if (avahi_glib_poll != NULL) {
		avahi_glib_poll_free(avahi_glib_poll);
		avahi_glib_poll = NULL;
	}

	avahi_free(avahiName);
	avahiName = NULL;
}