aboutsummaryrefslogtreecommitdiffstats
path: root/net/tipc/eth_media.c
blob: f71ba9db611e17607c0f7e99294b637b482bdf45 (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
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
/*
 * net/tipc/eth_media.c: Ethernet bearer support for TIPC
 *
 * Copyright (c) 2001-2006, Ericsson AB
 * Copyright (c) 2005-2006, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <net/tipc/tipc.h>
#include <net/tipc/tipc_bearer.h>
#include <net/tipc/tipc_msg.h>
#include <linux/netdevice.h>

#define MAX_ETH_BEARERS		2
#define ETH_LINK_PRIORITY	TIPC_DEF_LINK_PRI
#define ETH_LINK_TOLERANCE	TIPC_DEF_LINK_TOL
#define ETH_LINK_WINDOW		TIPC_DEF_LINK_WIN

/**
 * struct eth_bearer - Ethernet bearer data structure
 * @bearer: ptr to associated "generic" bearer structure
 * @dev: ptr to associated Ethernet network device
 * @tipc_packet_type: used in binding TIPC to Ethernet driver
 */

struct eth_bearer {
	struct tipc_bearer *bearer;
	struct net_device *dev;
	struct packet_type tipc_packet_type;
};

static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
static int eth_started = 0;
static struct notifier_block notifier;

/**
 * send_msg - send a TIPC message out over an Ethernet interface
 */

static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
		    struct tipc_media_addr *dest)
{
	struct sk_buff *clone;
	struct net_device *dev;

	clone = skb_clone(buf, GFP_ATOMIC);
	if (clone) {
		clone->nh.raw = clone->data;
		dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
		clone->dev = dev;
		dev->hard_header(clone, dev, ETH_P_TIPC,
				 &dest->dev_addr.eth_addr,
				 dev->dev_addr, clone->len);
		dev_queue_xmit(clone);
	}
	return TIPC_OK;
}

/**
 * recv_msg - handle incoming TIPC message from an Ethernet interface
 *
 * Routine truncates any Ethernet padding/CRC appended to the message,
 * and ensures message size matches actual length
 */

static int recv_msg(struct sk_buff *buf, struct net_device *dev,
		    struct packet_type *pt, struct net_device *orig_dev)
{
	struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
	u32 size;

	if (likely(eb_ptr->bearer)) {
	       if (likely(!dev->promiscuity) ||
		   !memcmp(buf->mac.raw,dev->dev_addr,ETH_ALEN) ||
		   !memcmp(buf->mac.raw,dev->broadcast,ETH_ALEN)) {
			size = msg_size((struct tipc_msg *)buf->data);
			skb_trim(buf, size);
			if (likely(buf->len == size)) {
				buf->next = NULL;
				tipc_recv_msg(buf, eb_ptr->bearer);
				return TIPC_OK;
			}
		}
	}
	kfree_skb(buf);
	return TIPC_OK;
}

/**
 * enable_bearer - attach TIPC bearer to an Ethernet interface
 */

static int enable_bearer(struct tipc_bearer *tb_ptr)
{
	struct net_device *dev = dev_base;
	struct eth_bearer *eb_ptr = &eth_bearers[0];
	struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
	char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;

	/* Find device with specified name */

	while (dev && dev->name && strncmp(dev->name, driver_name, IFNAMSIZ)) {
		dev = dev->next;
	}
	if (!dev)
		return -ENODEV;

	/* Find Ethernet bearer for device (or create one) */

	for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);
	if (eb_ptr == stop)
		return -EDQUOT;
	if (!eb_ptr->dev) {
		eb_ptr->dev = dev;
		eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
		eb_ptr->tipc_packet_type.dev = dev;
		eb_ptr->tipc_packet_type.func = recv_msg;
		eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
		INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
		dev_hold(dev);
		dev_add_pack(&eb_ptr->tipc_packet_type);
	}

	/* Associate TIPC bearer with Ethernet bearer */

	eb_ptr->bearer = tb_ptr;
	tb_ptr->usr_handle = (void *)eb_ptr;
	tb_ptr->mtu = dev->mtu;
	tb_ptr->blocked = 0;
	tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
	memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN);
	return 0;
}

/**
 * disable_bearer - detach TIPC bearer from an Ethernet interface
 *
 * We really should do dev_remove_pack() here, but this function can not be
 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
 */

static void disable_bearer(struct tipc_bearer *tb_ptr)
{
	((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL;
}

/**
 * recv_notification - handle device updates from OS
 *
 * Change the state of the Ethernet bearer (if any) associated with the
 * specified device.
 */

static int recv_notification(struct notifier_block *nb, unsigned long evt,
			     void *dv)
{
	struct net_device *dev = (struct net_device *)dv;
	struct eth_bearer *eb_ptr = &eth_bearers[0];
	struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];

	while ((eb_ptr->dev != dev)) {
		if (++eb_ptr == stop)
			return NOTIFY_DONE;	/* couldn't find device */
	}
	if (!eb_ptr->bearer)
		return NOTIFY_DONE;		/* bearer had been disabled */

	eb_ptr->bearer->mtu = dev->mtu;

	switch (evt) {
	case NETDEV_CHANGE:
		if (netif_carrier_ok(dev))
			tipc_continue(eb_ptr->bearer);
		else
			tipc_block_bearer(eb_ptr->bearer->name);
		break;
	case NETDEV_UP:
		tipc_continue(eb_ptr->bearer);
		break;
	case NETDEV_DOWN:
		tipc_block_bearer(eb_ptr->bearer->name);
		break;
	case NETDEV_CHANGEMTU:
	case NETDEV_CHANGEADDR:
		tipc_block_bearer(eb_ptr->bearer->name);
		tipc_continue(eb_ptr->bearer);
		break;
	case NETDEV_UNREGISTER:
	case NETDEV_CHANGENAME:
		tipc_disable_bearer(eb_ptr->bearer->name);
		break;
	}
	return NOTIFY_OK;
}

/**
 * eth_addr2str - convert Ethernet address to string
 */

static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
{
	unchar *addr = (unchar *)&a->dev_addr;

	if (str_size < 18)
		*str_buf = '\0';
	else
		sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
			addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
	return str_buf;
}

/**
 * tipc_eth_media_start - activate Ethernet bearer support
 *
 * Register Ethernet media type with TIPC bearer code.  Also register
 * with OS for notifications about device state changes.
 */

int tipc_eth_media_start(void)
{
	struct tipc_media_addr bcast_addr;
	int res;

	if (eth_started)
		return -EINVAL;

	bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
	memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN);

	memset(eth_bearers, 0, sizeof(eth_bearers));

	res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
				  enable_bearer, disable_bearer, send_msg,
				  eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
				  ETH_LINK_TOLERANCE, ETH_LINK_WINDOW);
	if (res)
		return res;

	notifier.notifier_call = &recv_notification;
	notifier.priority = 0;
	res = register_netdevice_notifier(&notifier);
	if (!res)
		eth_started = 1;
	return res;
}

/**
 * tipc_eth_media_stop - deactivate Ethernet bearer support
 */

void tipc_eth_media_stop(void)
{
	int i;

	if (!eth_started)
		return;

	unregister_netdevice_notifier(&notifier);
	for (i = 0; i < MAX_ETH_BEARERS ; i++) {
		if (eth_bearers[i].bearer) {
			eth_bearers[i].bearer->blocked = 1;
			eth_bearers[i].bearer = NULL;
		}
		if (eth_bearers[i].dev) {
			dev_remove_pack(&eth_bearers[i].tipc_packet_type);
			dev_put(eth_bearers[i].dev);
		}
	}
	memset(&eth_bearers, 0, sizeof(eth_bearers));
	eth_started = 0;
}