1 /*
2 * net/tipc/eth_media.c: Ethernet bearer support for TIPC
3 *
4 * Copyright (c) 2001-2007, Ericsson AB
5 * Copyright (c) 2005-2007, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 #include "core.h"
38 #include "bearer.h"
39
40 #define MAX_ETH_BEARERS 2
41 #define ETH_LINK_PRIORITY TIPC_DEF_LINK_PRI
42 #define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL
43 #define ETH_LINK_WINDOW TIPC_DEF_LINK_WIN
44
45 /**
46 * struct eth_bearer - Ethernet bearer data structure
47 * @bearer: ptr to associated "generic" bearer structure
48 * @dev: ptr to associated Ethernet network device
49 * @tipc_packet_type: used in binding TIPC to Ethernet driver
50 */
51
52 struct eth_bearer {
53 struct tipc_bearer *bearer;
54 struct net_device *dev;
55 struct packet_type tipc_packet_type;
56 };
57
58 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
59 static int eth_started;
60 static struct notifier_block notifier;
61
62 /**
63 * send_msg - send a TIPC message out over an Ethernet interface
64 */
65
send_msg(struct sk_buff * buf,struct tipc_bearer * tb_ptr,struct tipc_media_addr * dest)66 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
67 struct tipc_media_addr *dest)
68 {
69 struct sk_buff *clone;
70 struct net_device *dev;
71 int delta;
72
73 clone = skb_clone(buf, GFP_ATOMIC);
74 if (!clone)
75 return 0;
76
77 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
78 delta = dev->hard_header_len - skb_headroom(buf);
79
80 if ((delta > 0) &&
81 pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
82 kfree_skb(clone);
83 return 0;
84 }
85
86 skb_reset_network_header(clone);
87 clone->dev = dev;
88 dev_hard_header(clone, dev, ETH_P_TIPC, &dest->dev_addr.eth_addr,
89 dev->dev_addr, clone->len);
90 dev_queue_xmit(clone);
91 return 0;
92 }
93
94 /**
95 * recv_msg - handle incoming TIPC message from an Ethernet interface
96 *
97 * Accept only packets explicitly sent to this node, or broadcast packets;
98 * ignores packets sent using Ethernet multicast, and traffic sent to other
99 * nodes (which can happen if interface is running in promiscuous mode).
100 */
101
recv_msg(struct sk_buff * buf,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)102 static int recv_msg(struct sk_buff *buf, struct net_device *dev,
103 struct packet_type *pt, struct net_device *orig_dev)
104 {
105 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
106
107 if (!net_eq(dev_net(dev), &init_net)) {
108 kfree_skb(buf);
109 return 0;
110 }
111
112 if (likely(eb_ptr->bearer)) {
113 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
114 buf->next = NULL;
115 tipc_recv_msg(buf, eb_ptr->bearer);
116 return 0;
117 }
118 }
119 kfree_skb(buf);
120 return 0;
121 }
122
123 /**
124 * enable_bearer - attach TIPC bearer to an Ethernet interface
125 */
126
enable_bearer(struct tipc_bearer * tb_ptr)127 static int enable_bearer(struct tipc_bearer *tb_ptr)
128 {
129 struct net_device *dev = NULL;
130 struct net_device *pdev = NULL;
131 struct eth_bearer *eb_ptr = ð_bearers[0];
132 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS];
133 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
134 int pending_dev = 0;
135
136 /* Find unused Ethernet bearer structure */
137
138 while (eb_ptr->dev) {
139 if (!eb_ptr->bearer)
140 pending_dev++;
141 if (++eb_ptr == stop)
142 return pending_dev ? -EAGAIN : -EDQUOT;
143 }
144
145 /* Find device with specified name */
146
147 for_each_netdev(&init_net, pdev) {
148 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {
149 dev = pdev;
150 break;
151 }
152 }
153 if (!dev)
154 return -ENODEV;
155
156 /* Find Ethernet bearer for device (or create one) */
157
158 while ((eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev))
159 eb_ptr++;
160 if (eb_ptr == stop)
161 return -EDQUOT;
162 if (!eb_ptr->dev) {
163 eb_ptr->dev = dev;
164 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
165 eb_ptr->tipc_packet_type.dev = dev;
166 eb_ptr->tipc_packet_type.func = recv_msg;
167 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
168 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
169 dev_hold(dev);
170 dev_add_pack(&eb_ptr->tipc_packet_type);
171 }
172
173 /* Associate TIPC bearer with Ethernet bearer */
174
175 eb_ptr->bearer = tb_ptr;
176 tb_ptr->usr_handle = (void *)eb_ptr;
177 tb_ptr->mtu = dev->mtu;
178 tb_ptr->blocked = 0;
179 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
180 memcpy(&tb_ptr->addr.dev_addr, dev->dev_addr, ETH_ALEN);
181 return 0;
182 }
183
184 /**
185 * disable_bearer - detach TIPC bearer from an Ethernet interface
186 *
187 * We really should do dev_remove_pack() here, but this function can not be
188 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
189 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
190 */
191
disable_bearer(struct tipc_bearer * tb_ptr)192 static void disable_bearer(struct tipc_bearer *tb_ptr)
193 {
194 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL;
195 }
196
197 /**
198 * recv_notification - handle device updates from OS
199 *
200 * Change the state of the Ethernet bearer (if any) associated with the
201 * specified device.
202 */
203
recv_notification(struct notifier_block * nb,unsigned long evt,void * dv)204 static int recv_notification(struct notifier_block *nb, unsigned long evt,
205 void *dv)
206 {
207 struct net_device *dev = (struct net_device *)dv;
208 struct eth_bearer *eb_ptr = ð_bearers[0];
209 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS];
210
211 if (!net_eq(dev_net(dev), &init_net))
212 return NOTIFY_DONE;
213
214 while ((eb_ptr->dev != dev)) {
215 if (++eb_ptr == stop)
216 return NOTIFY_DONE; /* couldn't find device */
217 }
218 if (!eb_ptr->bearer)
219 return NOTIFY_DONE; /* bearer had been disabled */
220
221 eb_ptr->bearer->mtu = dev->mtu;
222
223 switch (evt) {
224 case NETDEV_CHANGE:
225 if (netif_carrier_ok(dev))
226 tipc_continue(eb_ptr->bearer);
227 else
228 tipc_block_bearer(eb_ptr->bearer->name);
229 break;
230 case NETDEV_UP:
231 tipc_continue(eb_ptr->bearer);
232 break;
233 case NETDEV_DOWN:
234 tipc_block_bearer(eb_ptr->bearer->name);
235 break;
236 case NETDEV_CHANGEMTU:
237 case NETDEV_CHANGEADDR:
238 tipc_block_bearer(eb_ptr->bearer->name);
239 tipc_continue(eb_ptr->bearer);
240 break;
241 case NETDEV_UNREGISTER:
242 case NETDEV_CHANGENAME:
243 tipc_disable_bearer(eb_ptr->bearer->name);
244 break;
245 }
246 return NOTIFY_OK;
247 }
248
249 /**
250 * eth_addr2str - convert Ethernet address to string
251 */
252
eth_addr2str(struct tipc_media_addr * a,char * str_buf,int str_size)253 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
254 {
255 unchar *addr = (unchar *)&a->dev_addr;
256
257 if (str_size < 18)
258 *str_buf = '\0';
259 else
260 sprintf(str_buf, "%pM", addr);
261 return str_buf;
262 }
263
264 /**
265 * tipc_eth_media_start - activate Ethernet bearer support
266 *
267 * Register Ethernet media type with TIPC bearer code. Also register
268 * with OS for notifications about device state changes.
269 */
270
tipc_eth_media_start(void)271 int tipc_eth_media_start(void)
272 {
273 struct tipc_media_addr bcast_addr;
274 int res;
275
276 if (eth_started)
277 return -EINVAL;
278
279 bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
280 memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN);
281
282 memset(eth_bearers, 0, sizeof(eth_bearers));
283
284 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
285 enable_bearer, disable_bearer, send_msg,
286 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
287 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW);
288 if (res)
289 return res;
290
291 notifier.notifier_call = &recv_notification;
292 notifier.priority = 0;
293 res = register_netdevice_notifier(¬ifier);
294 if (!res)
295 eth_started = 1;
296 return res;
297 }
298
299 /**
300 * tipc_eth_media_stop - deactivate Ethernet bearer support
301 */
302
tipc_eth_media_stop(void)303 void tipc_eth_media_stop(void)
304 {
305 int i;
306
307 if (!eth_started)
308 return;
309
310 unregister_netdevice_notifier(¬ifier);
311 for (i = 0; i < MAX_ETH_BEARERS ; i++) {
312 if (eth_bearers[i].bearer) {
313 eth_bearers[i].bearer->blocked = 1;
314 eth_bearers[i].bearer = NULL;
315 }
316 if (eth_bearers[i].dev) {
317 dev_remove_pack(ð_bearers[i].tipc_packet_type);
318 dev_put(eth_bearers[i].dev);
319 }
320 }
321 memset(ð_bearers, 0, sizeof(eth_bearers));
322 eth_started = 0;
323 }
324