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tipc: Simplify bearer shutdown logic
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CommitLineData
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1/*
2 * net/tipc/eth_media.c: Ethernet bearer support for TIPC
c4307285 3 *
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4 * Copyright (c) 2001-2007, Ericsson AB
5 * Copyright (c) 2005-2007, Wind River Systems
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6 * All rights reserved.
7 *
9ea1fd3c 8 * Redistribution and use in source and binary forms, with or without
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9 * modification, are permitted provided that the following conditions are met:
10 *
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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.
b97bf3fd 19 *
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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
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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>
5a0e3ad6 41#include <linux/slab.h>
e730c155 42#include <net/net_namespace.h>
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43
44#define MAX_ETH_BEARERS 2
16cb4b33 45#define ETH_LINK_PRIORITY TIPC_DEF_LINK_PRI
b97bf3fd 46#define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL
16cb4b33 47#define ETH_LINK_WINDOW TIPC_DEF_LINK_WIN
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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 */
c4307285 55
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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/**
c4307285 67 * send_msg - send a TIPC message out over an Ethernet interface
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68 */
69
c4307285 70static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
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71 struct tipc_media_addr *dest)
72{
73 struct sk_buff *clone;
74 struct net_device *dev;
9fbfca01 75 int delta;
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76
77 clone = skb_clone(buf, GFP_ATOMIC);
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78 if (!clone)
79 return 0;
80
81 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
82 delta = dev->hard_header_len - skb_headroom(buf);
83
84 if ((delta > 0) &&
85 pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
86 kfree_skb(clone);
87 return 0;
b97bf3fd 88 }
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89
90 skb_reset_network_header(clone);
91 clone->dev = dev;
92 dev_hard_header(clone, dev, ETH_P_TIPC, &dest->dev_addr.eth_addr,
93 dev->dev_addr, clone->len);
94 dev_queue_xmit(clone);
0e35fd5e 95 return 0;
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96}
97
98/**
99 * recv_msg - handle incoming TIPC message from an Ethernet interface
c4307285 100 *
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101 * Accept only packets explicitly sent to this node, or broadcast packets;
102 * ignores packets sent using Ethernet multicast, and traffic sent to other
103 * nodes (which can happen if interface is running in promiscuous mode).
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104 */
105
c4307285 106static int recv_msg(struct sk_buff *buf, struct net_device *dev,
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107 struct packet_type *pt, struct net_device *orig_dev)
108{
109 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
b97bf3fd 110
721499e8 111 if (!net_eq(dev_net(dev), &init_net)) {
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112 kfree_skb(buf);
113 return 0;
114 }
115
b97bf3fd 116 if (likely(eb_ptr->bearer)) {
f3ec75f6 117 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
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118 buf->next = NULL;
119 tipc_recv_msg(buf, eb_ptr->bearer);
120 return 0;
b97bf3fd 121 }
b97bf3fd 122 }
5e3c8854 123 kfree_skb(buf);
0e35fd5e 124 return 0;
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125}
126
127/**
c4307285 128 * enable_bearer - attach TIPC bearer to an Ethernet interface
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129 */
130
131static int enable_bearer(struct tipc_bearer *tb_ptr)
132{
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133 struct net_device *dev = NULL;
134 struct net_device *pdev = NULL;
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135 struct eth_bearer *eb_ptr = &eth_bearers[0];
136 struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
137 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
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138 int pending_dev = 0;
139
140 /* Find unused Ethernet bearer structure */
141
142 while (eb_ptr->dev) {
143 if (!eb_ptr->bearer)
144 pending_dev++;
145 if (++eb_ptr == stop)
146 return pending_dev ? -EAGAIN : -EDQUOT;
147 }
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148
149 /* Find device with specified name */
cb283ead 150
881d966b 151 for_each_netdev(&init_net, pdev){
cb283ead 152 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {
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153 dev = pdev;
154 break;
155 }
cb283ead 156 }
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157 if (!dev)
158 return -ENODEV;
159
160 /* Find Ethernet bearer for device (or create one) */
161
162 for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);
163 if (eb_ptr == stop)
164 return -EDQUOT;
165 if (!eb_ptr->dev) {
166 eb_ptr->dev = dev;
02ea4923 167 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
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168 eb_ptr->tipc_packet_type.dev = dev;
169 eb_ptr->tipc_packet_type.func = recv_msg;
170 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
171 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
172 dev_hold(dev);
173 dev_add_pack(&eb_ptr->tipc_packet_type);
174 }
175
176 /* Associate TIPC bearer with Ethernet bearer */
177
178 eb_ptr->bearer = tb_ptr;
179 tb_ptr->usr_handle = (void *)eb_ptr;
180 tb_ptr->mtu = dev->mtu;
c4307285 181 tb_ptr->blocked = 0;
b97bf3fd 182 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
3a6d54c5 183 memcpy(&tb_ptr->addr.dev_addr, dev->dev_addr, ETH_ALEN);
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184 return 0;
185}
186
187/**
c4307285 188 * disable_bearer - detach TIPC bearer from an Ethernet interface
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189 *
190 * We really should do dev_remove_pack() here, but this function can not be
191 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
192 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
193 */
194
195static void disable_bearer(struct tipc_bearer *tb_ptr)
196{
1fc54d8f 197 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL;
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198}
199
200/**
201 * recv_notification - handle device updates from OS
202 *
c4307285 203 * Change the state of the Ethernet bearer (if any) associated with the
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204 * specified device.
205 */
206
c4307285 207static int recv_notification(struct notifier_block *nb, unsigned long evt,
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208 void *dv)
209{
210 struct net_device *dev = (struct net_device *)dv;
211 struct eth_bearer *eb_ptr = &eth_bearers[0];
212 struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
213
721499e8 214 if (!net_eq(dev_net(dev), &init_net))
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215 return NOTIFY_DONE;
216
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217 while ((eb_ptr->dev != dev)) {
218 if (++eb_ptr == stop)
219 return NOTIFY_DONE; /* couldn't find device */
220 }
221 if (!eb_ptr->bearer)
222 return NOTIFY_DONE; /* bearer had been disabled */
223
c4307285 224 eb_ptr->bearer->mtu = dev->mtu;
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225
226 switch (evt) {
227 case NETDEV_CHANGE:
228 if (netif_carrier_ok(dev))
229 tipc_continue(eb_ptr->bearer);
230 else
231 tipc_block_bearer(eb_ptr->bearer->name);
232 break;
233 case NETDEV_UP:
234 tipc_continue(eb_ptr->bearer);
235 break;
236 case NETDEV_DOWN:
237 tipc_block_bearer(eb_ptr->bearer->name);
238 break;
239 case NETDEV_CHANGEMTU:
c4307285 240 case NETDEV_CHANGEADDR:
b97bf3fd 241 tipc_block_bearer(eb_ptr->bearer->name);
c4307285 242 tipc_continue(eb_ptr->bearer);
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243 break;
244 case NETDEV_UNREGISTER:
c4307285 245 case NETDEV_CHANGENAME:
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246 tipc_disable_bearer(eb_ptr->bearer->name);
247 break;
248 }
249 return NOTIFY_OK;
250}
251
252/**
253 * eth_addr2str - convert Ethernet address to string
254 */
255
256static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
c4307285 257{
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258 unchar *addr = (unchar *)&a->dev_addr;
259
260 if (str_size < 18)
261 *str_buf = '\0';
262 else
e174961c 263 sprintf(str_buf, "%pM", addr);
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264 return str_buf;
265}
266
267/**
4323add6 268 * tipc_eth_media_start - activate Ethernet bearer support
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269 *
270 * Register Ethernet media type with TIPC bearer code. Also register
271 * with OS for notifications about device state changes.
272 */
273
4323add6 274int tipc_eth_media_start(void)
c4307285 275{
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276 struct tipc_media_addr bcast_addr;
277 int res;
278
279 if (eth_started)
280 return -EINVAL;
281
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282 bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
283 memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN);
284
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285 memset(eth_bearers, 0, sizeof(eth_bearers));
286
287 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
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288 enable_bearer, disable_bearer, send_msg,
289 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
16cb4b33 290 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW);
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291 if (res)
292 return res;
293
294 notifier.notifier_call = &recv_notification;
295 notifier.priority = 0;
296 res = register_netdevice_notifier(&notifier);
297 if (!res)
298 eth_started = 1;
299 return res;
300}
301
302/**
4323add6 303 * tipc_eth_media_stop - deactivate Ethernet bearer support
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304 */
305
4323add6 306void tipc_eth_media_stop(void)
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307{
308 int i;
309
310 if (!eth_started)
311 return;
312
313 unregister_netdevice_notifier(&notifier);
314 for (i = 0; i < MAX_ETH_BEARERS ; i++) {
315 if (eth_bearers[i].bearer) {
316 eth_bearers[i].bearer->blocked = 1;
1fc54d8f 317 eth_bearers[i].bearer = NULL;
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318 }
319 if (eth_bearers[i].dev) {
320 dev_remove_pack(&eth_bearers[i].tipc_packet_type);
321 dev_put(eth_bearers[i].dev);
322 }
323 }
324 memset(&eth_bearers, 0, sizeof(eth_bearers));
325 eth_started = 0;
326}