summaryrefslogtreecommitdiff
path: root/src/tethering.c
blob: decb1122689db881aea8507a6536e9a3e30de765 (plain)
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
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
/*
 *
 *  Connection Manager
 *
 *  Copyright (C) 2007-2012  Intel Corporation. All rights reserved.
 *  Copyright (C) 2011	ProFUSION embedded systems
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  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 St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/sockios.h>
#include <string.h>
#include <fcntl.h>
#include <linux/if_tun.h>

#include "connman.h"

#include <gdhcp/gdhcp.h>

#include <gdbus.h>

#ifndef DBUS_TYPE_UNIX_FD
#define DBUS_TYPE_UNIX_FD -1
#endif

#define BRIDGE_PROC_DIR "/proc/sys/net/bridge"

#define BRIDGE_NAME "tether"
#define BRIDGE_DNS "8.8.8.8"

#define DEFAULT_MTU	1500

#define PRIVATE_NETWORK_PRIMARY_DNS BRIDGE_DNS
#define PRIVATE_NETWORK_SECONDARY_DNS "8.8.4.4"

static volatile int tethering_enabled;
static GDHCPServer *tethering_dhcp_server = NULL;
static struct connman_ippool *dhcp_ippool = NULL;
static DBusConnection *connection;
static GHashTable *pn_hash;

struct connman_private_network {
	char *owner;
	char *path;
	guint watch;
	DBusMessage *msg;
	DBusMessage *reply;
	int fd;
	char *interface;
	int index;
	guint iface_watch;
	struct connman_ippool *pool;
	const char *primary_dns;
	const char *secondary_dns;
};

const char *__connman_tethering_get_bridge(void)
{
	struct stat st;

	if (stat(BRIDGE_PROC_DIR, &st) < 0) {
		connman_error("Missing support for 802.1d ethernet bridging");
		return NULL;
	}

	return BRIDGE_NAME;
}

static void dhcp_server_debug(const char *str, void *data)
{
	connman_info("%s: %s\n", (const char *) data, str);
}

static void dhcp_server_error(GDHCPServerError error)
{
	switch (error) {
	case G_DHCP_SERVER_ERROR_NONE:
		connman_error("OK");
		break;
	case G_DHCP_SERVER_ERROR_INTERFACE_UNAVAILABLE:
		connman_error("Interface unavailable");
		break;
	case G_DHCP_SERVER_ERROR_INTERFACE_IN_USE:
		connman_error("Interface in use");
		break;
	case G_DHCP_SERVER_ERROR_INTERFACE_DOWN:
		connman_error("Interface down");
		break;
	case G_DHCP_SERVER_ERROR_NOMEM:
		connman_error("No memory");
		break;
	case G_DHCP_SERVER_ERROR_INVALID_INDEX:
		connman_error("Invalid index");
		break;
	case G_DHCP_SERVER_ERROR_INVALID_OPTION:
		connman_error("Invalid option");
		break;
	case G_DHCP_SERVER_ERROR_IP_ADDRESS_INVALID:
		connman_error("Invalid address");
		break;
	}
}

static GDHCPServer *dhcp_server_start(const char *bridge,
				const char *router, const char* subnet,
				const char *start_ip, const char *end_ip,
				unsigned int lease_time, const char *dns)
{
	GDHCPServerError error;
	GDHCPServer *dhcp_server;
	int index;

	DBG("");

	index = connman_inet_ifindex(bridge);
	if (index < 0)
		return NULL;

	dhcp_server = g_dhcp_server_new(G_DHCP_IPV4, index, &error);
	if (dhcp_server == NULL) {
		dhcp_server_error(error);
		return NULL;
	}

	g_dhcp_server_set_debug(dhcp_server, dhcp_server_debug, "DHCP server");

	g_dhcp_server_set_lease_time(dhcp_server, lease_time);
	g_dhcp_server_set_option(dhcp_server, G_DHCP_SUBNET, subnet);
	g_dhcp_server_set_option(dhcp_server, G_DHCP_ROUTER, router);
	g_dhcp_server_set_option(dhcp_server, G_DHCP_DNS_SERVER, dns);
	g_dhcp_server_set_ip_range(dhcp_server, start_ip, end_ip);

	g_dhcp_server_start(dhcp_server);

	return dhcp_server;
}

static void dhcp_server_stop(GDHCPServer *server)
{
	if (server == NULL)
		return;

	g_dhcp_server_unref(server);
}

static void tethering_restart(struct connman_ippool *pool, void *user_data)
{
	__connman_tethering_set_disabled();
	__connman_tethering_set_enabled();
}

void __connman_tethering_set_enabled(void)
{
	int index;
	int err;
	const char *gateway;
	const char *broadcast;
	const char *subnet_mask;
	const char *start_ip;
	const char *end_ip;
	const char *dns;
	unsigned char prefixlen;

	DBG("enabled %d", tethering_enabled + 1);

	if (__sync_fetch_and_add(&tethering_enabled, 1) != 0)
		return;

	err = __connman_bridge_create(BRIDGE_NAME);
	if (err < 0)
		return;

	index = connman_inet_ifindex(BRIDGE_NAME);
	dhcp_ippool = __connman_ippool_create(index, 2, 252,
						tethering_restart, NULL);
	if (dhcp_ippool == NULL) {
		connman_error("Fail to create IP pool");
		return;
	}

	gateway = __connman_ippool_get_gateway(dhcp_ippool);
	broadcast = __connman_ippool_get_broadcast(dhcp_ippool);
	subnet_mask = __connman_ippool_get_subnet_mask(dhcp_ippool);
	start_ip = __connman_ippool_get_start_ip(dhcp_ippool);
	end_ip = __connman_ippool_get_end_ip(dhcp_ippool);

	err = __connman_bridge_enable(BRIDGE_NAME, gateway, broadcast);
	if (err < 0 && err != -EALREADY) {
		__connman_bridge_remove(BRIDGE_NAME);
		return;
	}

	dns = gateway;
	if (__connman_dnsproxy_add_listener(BRIDGE_NAME) < 0) {
		connman_error("Can't add listener %s to DNS proxy",
								BRIDGE_NAME);
		dns = BRIDGE_DNS;
	}

	tethering_dhcp_server = dhcp_server_start(BRIDGE_NAME,
						gateway, subnet_mask,
						start_ip, end_ip,
						24 * 3600, dns);
	if (tethering_dhcp_server == NULL) {
		__connman_bridge_disable(BRIDGE_NAME);
		__connman_bridge_remove(BRIDGE_NAME);
		return;
	}

	prefixlen =
		__connman_ipconfig_netmask_prefix_len(subnet_mask);
	__connman_nat_enable(BRIDGE_NAME, start_ip, prefixlen);

	DBG("tethering started");
}

void __connman_tethering_set_disabled(void)
{
	DBG("enabled %d", tethering_enabled - 1);

	__connman_dnsproxy_remove_listener(BRIDGE_NAME);

	if (__sync_fetch_and_sub(&tethering_enabled, 1) != 1)
		return;

	__connman_nat_disable(BRIDGE_NAME);

	dhcp_server_stop(tethering_dhcp_server);

	tethering_dhcp_server = NULL;

	__connman_bridge_disable(BRIDGE_NAME);

	__connman_ippool_unref(dhcp_ippool);

	__connman_bridge_remove(BRIDGE_NAME);

	DBG("tethering stopped");
}

static void setup_tun_interface(unsigned int flags, unsigned change,
		void *data)
{
	struct connman_private_network *pn = data;
	unsigned char prefixlen;
	DBusMessageIter array, dict;
	const char *server_ip;
	const char *peer_ip;
	const char *subnet_mask;
	int err;

	DBG("index %d flags %d change %d", pn->index,  flags, change);

	if (flags & IFF_UP)
		return;

	subnet_mask = __connman_ippool_get_subnet_mask(pn->pool);
	server_ip = __connman_ippool_get_start_ip(pn->pool);
	peer_ip = __connman_ippool_get_end_ip(pn->pool);
	prefixlen =
		__connman_ipconfig_netmask_prefix_len(subnet_mask);

	if ((__connman_inet_modify_address(RTM_NEWADDR,
				NLM_F_REPLACE | NLM_F_ACK, pn->index, AF_INET,
				server_ip, peer_ip, prefixlen, NULL)) < 0) {
		DBG("address setting failed");
		return;
	}

	connman_inet_ifup(pn->index);

	err = __connman_nat_enable(BRIDGE_NAME, server_ip, prefixlen);
	if (err < 0) {
		connman_error("failed to enable NAT");
		goto error;
	}

	dbus_message_iter_init_append(pn->reply, &array);

	dbus_message_iter_append_basic(&array, DBUS_TYPE_OBJECT_PATH,
						&pn->path);

	connman_dbus_dict_open(&array, &dict);

	connman_dbus_dict_append_basic(&dict, "ServerIPv4",
					DBUS_TYPE_STRING, &server_ip);
	connman_dbus_dict_append_basic(&dict, "PeerIPv4",
					DBUS_TYPE_STRING, &peer_ip);
	connman_dbus_dict_append_basic(&dict, "PrimaryDNS",
					DBUS_TYPE_STRING, &pn->primary_dns);
	connman_dbus_dict_append_basic(&dict, "SecondaryDNS",
					DBUS_TYPE_STRING, &pn->secondary_dns);

	connman_dbus_dict_close(&array, &dict);

	dbus_message_iter_append_basic(&array, DBUS_TYPE_UNIX_FD, &pn->fd);

	g_dbus_send_message(connection, pn->reply);

	return;

error:
	pn->reply = __connman_error_failed(pn->msg, -err);
	g_dbus_send_message(connection, pn->reply);

	g_hash_table_remove(pn_hash, pn->path);
}

static void remove_private_network(gpointer user_data)
{
	struct connman_private_network *pn = user_data;

	__connman_nat_disable(BRIDGE_NAME);
	connman_rtnl_remove_watch(pn->iface_watch);
	__connman_ippool_unref(pn->pool);

	if (pn->watch > 0) {
		g_dbus_remove_watch(connection, pn->watch);
		pn->watch = 0;
	}

	close(pn->fd);

	g_free(pn->interface);
	g_free(pn->owner);
	g_free(pn->path);
	g_free(pn);
}

static void owner_disconnect(DBusConnection *conn, void *user_data)
{
	struct connman_private_network *pn = user_data;

	DBG("%s died", pn->owner);

	pn->watch = 0;

	g_hash_table_remove(pn_hash, pn->path);
}

static void ippool_disconnect(struct connman_ippool *pool, void *user_data)
{
	struct connman_private_network *pn = user_data;

	DBG("block used externally");

	g_hash_table_remove(pn_hash, pn->path);
}

int __connman_private_network_request(DBusMessage *msg, const char *owner)
{
	struct connman_private_network *pn;
	char *iface = NULL;
	char *path = NULL;
	int index, fd, err;

	if (DBUS_TYPE_UNIX_FD < 0)
		return -EINVAL;

	fd = connman_inet_create_tunnel(&iface);
	if (fd < 0)
		return fd;

	path = g_strdup_printf("/tethering/%s", iface);

	pn = g_hash_table_lookup(pn_hash, path);
	if (pn) {
		g_free(path);
		g_free(iface);
		close(fd);
		return -EEXIST;
	}

	index = connman_inet_ifindex(iface);
	if (index < 0) {
		err = -ENODEV;
		goto error;
	}
	DBG("interface %s", iface);

	err = connman_inet_set_mtu(index, DEFAULT_MTU);

	pn = g_try_new0(struct connman_private_network, 1);
	if (pn == NULL) {
		err = -ENOMEM;
		goto error;
	}

	pn->owner = g_strdup(owner);
	pn->path = path;
	pn->watch = g_dbus_add_disconnect_watch(connection, pn->owner,
					owner_disconnect, pn, NULL);
	pn->msg = msg;
	pn->reply = dbus_message_new_method_return(pn->msg);
	if (pn->reply == NULL)
		goto error;

	pn->fd = fd;
	pn->interface = iface;
	pn->index = index;
	pn->pool = __connman_ippool_create(pn->index, 1, 1, ippool_disconnect, pn);
	if (pn->pool == NULL) {
		errno = -ENOMEM;
		goto error;
	}

	pn->primary_dns = PRIVATE_NETWORK_PRIMARY_DNS;
	pn->secondary_dns = PRIVATE_NETWORK_SECONDARY_DNS;

	pn->iface_watch = connman_rtnl_add_newlink_watch(index,
						setup_tun_interface, pn);

	g_hash_table_insert(pn_hash, pn->path, pn);

	return 0;

error:
	close(fd);
	g_free(iface);
	g_free(path);
	g_free(pn);
	return err;
}

int __connman_private_network_release(const char *path)
{
	struct connman_private_network *pn;

	pn = g_hash_table_lookup(pn_hash, path);
	if (pn == NULL)
		return -EACCES;

	g_hash_table_remove(pn_hash, path);
	return 0;
}

int __connman_tethering_init(void)
{
	DBG("");

	tethering_enabled = 0;

	connection = connman_dbus_get_connection();
	if (connection == NULL)
		return -EFAULT;

	pn_hash = g_hash_table_new_full(g_str_hash, g_str_equal,
						NULL, remove_private_network);

	return 0;
}

void __connman_tethering_cleanup(void)
{
	DBG("");

	__sync_synchronize();
	if (tethering_enabled == 0) {
		if (tethering_dhcp_server)
			dhcp_server_stop(tethering_dhcp_server);
		__connman_bridge_disable(BRIDGE_NAME);
		__connman_bridge_remove(BRIDGE_NAME);
		__connman_nat_disable(BRIDGE_NAME);
	}

	if (connection == NULL)
		return;

	g_hash_table_destroy(pn_hash);
	dbus_connection_unref(connection);
}