tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * net/tipc/eth_media.c: Ethernet bearer support for TIPC
3 *
4 * Copyright (c) 2001-2006, Ericsson AB
5 * Copyright (c) 2005, 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 <net/tipc/tipc.h>
38#include <net/tipc/tipc_bearer.h>
39#include <net/tipc/tipc_msg.h>
40#include <linux/netdevice.h>
41#include <linux/version.h>
42
43#define MAX_ETH_BEARERS 2
44#define TIPC_PROTOCOL 0x88ca
45#define ETH_LINK_PRIORITY 10
46#define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL
47
48
49/**
50 * struct eth_bearer - Ethernet bearer data structure
51 * @bearer: ptr to associated "generic" bearer structure
52 * @dev: ptr to associated Ethernet network device
53 * @tipc_packet_type: used in binding TIPC to Ethernet driver
54 */
55
56struct eth_bearer {
57 struct tipc_bearer *bearer;
58 struct net_device *dev;
59 struct packet_type tipc_packet_type;
60};
61
62static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
63static int eth_started = 0;
64static struct notifier_block notifier;
65
66/**
67 * send_msg - send a TIPC message out over an Ethernet interface
68 */
69
70static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
71 struct tipc_media_addr *dest)
72{
73 struct sk_buff *clone;
74 struct net_device *dev;
75
76 clone = skb_clone(buf, GFP_ATOMIC);
77 if (clone) {
78 clone->nh.raw = clone->data;
79 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
80 clone->dev = dev;
81 dev->hard_header(clone, dev, TIPC_PROTOCOL,
82 &dest->dev_addr.eth_addr,
83 dev->dev_addr, clone->len);
84 dev_queue_xmit(clone);
85 }
86 return TIPC_OK;
87}
88
89/**
90 * recv_msg - handle incoming TIPC message from an Ethernet interface
91 *
92 * Routine truncates any Ethernet padding/CRC appended to the message,
93 * and ensures message size matches actual length
94 */
95
96static int recv_msg(struct sk_buff *buf, struct net_device *dev,
97 struct packet_type *pt, struct net_device *orig_dev)
98{
99 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
100 u32 size;
101
102 if (likely(eb_ptr->bearer)) {
103 size = msg_size((struct tipc_msg *)buf->data);
104 skb_trim(buf, size);
105 if (likely(buf->len == size)) {
106 buf->next = NULL;
107 tipc_recv_msg(buf, eb_ptr->bearer);
108 } else {
109 kfree_skb(buf);
110 }
111 } else {
112 kfree_skb(buf);
113 }
114 return TIPC_OK;
115}
116
117/**
118 * enable_bearer - attach TIPC bearer to an Ethernet interface
119 */
120
121static int enable_bearer(struct tipc_bearer *tb_ptr)
122{
123 struct net_device *dev = dev_base;
124 struct eth_bearer *eb_ptr = ð_bearers[0];
125 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS];
126 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
127
128 /* Find device with specified name */
129
130 while (dev && dev->name &&
131 (memcmp(dev->name, driver_name, strlen(dev->name)))) {
132 dev = dev->next;
133 }
134 if (!dev)
135 return -ENODEV;
136
137 /* Find Ethernet bearer for device (or create one) */
138
139 for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);
140 if (eb_ptr == stop)
141 return -EDQUOT;
142 if (!eb_ptr->dev) {
143 eb_ptr->dev = dev;
144 eb_ptr->tipc_packet_type.type = __constant_htons(TIPC_PROTOCOL);
145 eb_ptr->tipc_packet_type.dev = dev;
146 eb_ptr->tipc_packet_type.func = recv_msg;
147 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
148 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
149 dev_hold(dev);
150 dev_add_pack(&eb_ptr->tipc_packet_type);
151 }
152
153 /* Associate TIPC bearer with Ethernet bearer */
154
155 eb_ptr->bearer = tb_ptr;
156 tb_ptr->usr_handle = (void *)eb_ptr;
157 tb_ptr->mtu = dev->mtu;
158 tb_ptr->blocked = 0;
159 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
160 memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN);
161 return 0;
162}
163
164/**
165 * disable_bearer - detach TIPC bearer from an Ethernet interface
166 *
167 * We really should do dev_remove_pack() here, but this function can not be
168 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
169 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
170 */
171
172static void disable_bearer(struct tipc_bearer *tb_ptr)
173{
174 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = 0;
175}
176
177/**
178 * recv_notification - handle device updates from OS
179 *
180 * Change the state of the Ethernet bearer (if any) associated with the
181 * specified device.
182 */
183
184static int recv_notification(struct notifier_block *nb, unsigned long evt,
185 void *dv)
186{
187 struct net_device *dev = (struct net_device *)dv;
188 struct eth_bearer *eb_ptr = ð_bearers[0];
189 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS];
190
191 while ((eb_ptr->dev != dev)) {
192 if (++eb_ptr == stop)
193 return NOTIFY_DONE; /* couldn't find device */
194 }
195 if (!eb_ptr->bearer)
196 return NOTIFY_DONE; /* bearer had been disabled */
197
198 eb_ptr->bearer->mtu = dev->mtu;
199
200 switch (evt) {
201 case NETDEV_CHANGE:
202 if (netif_carrier_ok(dev))
203 tipc_continue(eb_ptr->bearer);
204 else
205 tipc_block_bearer(eb_ptr->bearer->name);
206 break;
207 case NETDEV_UP:
208 tipc_continue(eb_ptr->bearer);
209 break;
210 case NETDEV_DOWN:
211 tipc_block_bearer(eb_ptr->bearer->name);
212 break;
213 case NETDEV_CHANGEMTU:
214 case NETDEV_CHANGEADDR:
215 tipc_block_bearer(eb_ptr->bearer->name);
216 tipc_continue(eb_ptr->bearer);
217 break;
218 case NETDEV_UNREGISTER:
219 case NETDEV_CHANGENAME:
220 tipc_disable_bearer(eb_ptr->bearer->name);
221 break;
222 }
223 return NOTIFY_OK;
224}
225
226/**
227 * eth_addr2str - convert Ethernet address to string
228 */
229
230static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
231{
232 unchar *addr = (unchar *)&a->dev_addr;
233
234 if (str_size < 18)
235 *str_buf = '\0';
236 else
237 sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
238 addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
239 return str_buf;
240}
241
242/**
243 * eth_media_start - activate Ethernet bearer support
244 *
245 * Register Ethernet media type with TIPC bearer code. Also register
246 * with OS for notifications about device state changes.
247 */
248
249int eth_media_start(void)
250{
251 struct tipc_media_addr bcast_addr;
252 int res;
253
254 if (eth_started)
255 return -EINVAL;
256
257 memset(&bcast_addr, 0xff, sizeof(bcast_addr));
258 memset(eth_bearers, 0, sizeof(eth_bearers));
259
260 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
261 enable_bearer, disable_bearer, send_msg,
262 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
263 ETH_LINK_TOLERANCE, TIPC_DEF_LINK_WIN);
264 if (res)
265 return res;
266
267 notifier.notifier_call = &recv_notification;
268 notifier.priority = 0;
269 res = register_netdevice_notifier(¬ifier);
270 if (!res)
271 eth_started = 1;
272 return res;
273}
274
275/**
276 * eth_media_stop - deactivate Ethernet bearer support
277 */
278
279void eth_media_stop(void)
280{
281 int i;
282
283 if (!eth_started)
284 return;
285
286 unregister_netdevice_notifier(¬ifier);
287 for (i = 0; i < MAX_ETH_BEARERS ; i++) {
288 if (eth_bearers[i].bearer) {
289 eth_bearers[i].bearer->blocked = 1;
290 eth_bearers[i].bearer = 0;
291 }
292 if (eth_bearers[i].dev) {
293 dev_remove_pack(ð_bearers[i].tipc_packet_type);
294 dev_put(eth_bearers[i].dev);
295 }
296 }
297 memset(ð_bearers, 0, sizeof(eth_bearers));
298 eth_started = 0;
299}