1 /*
2 * Userspace interface
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
8 * $Id: br_if.c,v 1.7 2001/12/24 00:59:55 davem Exp $
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/netdevice.h>
18 #include <linux/ethtool.h>
19 #include <linux/if_arp.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/rtnetlink.h>
23 #include <linux/if_ether.h>
24 #include <net/sock.h>
25
26 #include "br_private.h"
27
28 /*
29 * Determine initial path cost based on speed.
30 * using recommendations from 802.1d standard
31 *
32 * Since driver might sleep need to not be holding any locks.
33 */
34 static int port_cost(struct net_device *dev)
35 {
36 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
37 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
38
39 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) {
40 switch(ecmd.speed) {
41 case SPEED_10000:
42 return 2;
43 case SPEED_1000:
44 return 4;
45 case SPEED_100:
46 return 19;
47 case SPEED_10:
48 return 100;
49 }
50 }
51 }
52
53 /* Old silly heuristics based on name */
54 if (!strncmp(dev->name, "lec", 3))
55 return 7;
56
57 if (!strncmp(dev->name, "plip", 4))
58 return 2500;
59
60 return 100; /* assume old 10Mbps */
61 }
62
63
64 /*
65 * Check for port carrier transistions.
66 * Called from work queue to allow for calling functions that
67 * might sleep (such as speed check), and to debounce.
68 */
69 void br_port_carrier_check(struct net_bridge_port *p)
70 {
71 struct net_device *dev = p->dev;
72 struct net_bridge *br = p->br;
73
74 if (netif_carrier_ok(dev))
75 p->path_cost = port_cost(dev);
76
77 if (netif_running(br->dev)) {
78 spin_lock_bh(&br->lock);
79 if (netif_carrier_ok(dev)) {
80 if (p->state == BR_STATE_DISABLED)
81 br_stp_enable_port(p);
82 } else {
83 if (p->state != BR_STATE_DISABLED)
84 br_stp_disable_port(p);
85 }
86 spin_unlock_bh(&br->lock);
87 }
88 }
89
90 static void release_nbp(struct kobject *kobj)
91 {
92 struct net_bridge_port *p
93 = container_of(kobj, struct net_bridge_port, kobj);
94 kfree(p);
95 }
96
97 static struct kobj_type brport_ktype = {
98 #ifdef CONFIG_SYSFS
99 .sysfs_ops = &brport_sysfs_ops,
100 #endif
101 .release = release_nbp,
102 };
103
104 static void destroy_nbp(struct net_bridge_port *p)
105 {
106 struct net_device *dev = p->dev;
107
108 p->br = NULL;
109 p->dev = NULL;
110 dev_put(dev);
111
112 kobject_put(&p->kobj);
113 }
114
115 static void destroy_nbp_rcu(struct rcu_head *head)
116 {
117 struct net_bridge_port *p =
118 container_of(head, struct net_bridge_port, rcu);
119 destroy_nbp(p);
120 }
121
122 /* Delete port(interface) from bridge is done in two steps.
123 * via RCU. First step, marks device as down. That deletes
124 * all the timers and stops new packets from flowing through.
125 *
126 * Final cleanup doesn't occur until after all CPU's finished
127 * processing packets.
128 *
129 * Protected from multiple admin operations by RTNL mutex
130 */
131 static void del_nbp(struct net_bridge_port *p)
132 {
133 struct net_bridge *br = p->br;
134 struct net_device *dev = p->dev;
135
136 sysfs_remove_link(br->ifobj, dev->name);
137
138 dev_set_promiscuity(dev, -1);
139
140 spin_lock_bh(&br->lock);
141 br_stp_disable_port(p);
142 spin_unlock_bh(&br->lock);
143
144 br_ifinfo_notify(RTM_DELLINK, p);
145
146 br_fdb_delete_by_port(br, p, 1);
147
148 list_del_rcu(&p->list);
149
150 rcu_assign_pointer(dev->br_port, NULL);
151
152 kobject_uevent(&p->kobj, KOBJ_REMOVE);
153 kobject_del(&p->kobj);
154
155 call_rcu(&p->rcu, destroy_nbp_rcu);
156 }
157
158 /* called with RTNL */
159 static void del_br(struct net_bridge *br)
160 {
161 struct net_bridge_port *p, *n;
162
163 list_for_each_entry_safe(p, n, &br->port_list, list) {
164 del_nbp(p);
165 }
166
167 del_timer_sync(&br->gc_timer);
168
169 br_sysfs_delbr(br->dev);
170 unregister_netdevice(br->dev);
171 }
172
173 static struct net_device *new_bridge_dev(const char *name)
174 {
175 struct net_bridge *br;
176 struct net_device *dev;
177
178 dev = alloc_netdev(sizeof(struct net_bridge), name,
179 br_dev_setup);
180
181 if (!dev)
182 return NULL;
183
184 br = netdev_priv(dev);
185 br->dev = dev;
186
187 spin_lock_init(&br->lock);
188 INIT_LIST_HEAD(&br->port_list);
189 spin_lock_init(&br->hash_lock);
190
191 br->bridge_id.prio[0] = 0x80;
192 br->bridge_id.prio[1] = 0x00;
193
194 memcpy(br->group_addr, br_group_address, ETH_ALEN);
195
196 br->feature_mask = dev->features;
197 br->stp_enabled = BR_NO_STP;
198 br->designated_root = br->bridge_id;
199 br->root_path_cost = 0;
200 br->root_port = 0;
201 br->bridge_max_age = br->max_age = 20 * HZ;
202 br->bridge_hello_time = br->hello_time = 2 * HZ;
203 br->bridge_forward_delay = br->forward_delay = 15 * HZ;
204 br->topology_change = 0;
205 br->topology_change_detected = 0;
206 br->ageing_time = 300 * HZ;
207 INIT_LIST_HEAD(&br->age_list);
208
209 br_stp_timer_init(br);
210
211 return dev;
212 }
213
214 /* find an available port number */
215 static int find_portno(struct net_bridge *br)
216 {
217 int index;
218 struct net_bridge_port *p;
219 unsigned long *inuse;
220
221 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
222 GFP_KERNEL);
223 if (!inuse)
224 return -ENOMEM;
225
226 set_bit(0, inuse); /* zero is reserved */
227 list_for_each_entry(p, &br->port_list, list) {
228 set_bit(p->port_no, inuse);
229 }
230 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
231 kfree(inuse);
232
233 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
234 }
235
236 /* called with RTNL but without bridge lock */
237 static struct net_bridge_port *new_nbp(struct net_bridge *br,
238 struct net_device *dev)
239 {
240 int index;
241 struct net_bridge_port *p;
242
243 index = find_portno(br);
244 if (index < 0)
245 return ERR_PTR(index);
246
247 p = kzalloc(sizeof(*p), GFP_KERNEL);
248 if (p == NULL)
249 return ERR_PTR(-ENOMEM);
250
251 p->br = br;
252 dev_hold(dev);
253 p->dev = dev;
254 p->path_cost = port_cost(dev);
255 p->priority = 0x8000 >> BR_PORT_BITS;
256 p->port_no = index;
257 br_init_port(p);
258 p->state = BR_STATE_DISABLED;
259 br_stp_port_timer_init(p);
260
261 return p;
262 }
263
264 int br_add_bridge(const char *name)
265 {
266 struct net_device *dev;
267 int ret;
268
269 dev = new_bridge_dev(name);
270 if (!dev)
271 return -ENOMEM;
272
273 rtnl_lock();
274 if (strchr(dev->name, '%')) {
275 ret = dev_alloc_name(dev, dev->name);
276 if (ret < 0) {
277 free_netdev(dev);
278 goto out;
279 }
280 }
281
282 ret = register_netdevice(dev);
283 if (ret)
284 goto out;
285
286 ret = br_sysfs_addbr(dev);
287 if (ret)
288 unregister_netdevice(dev);
289 out:
290 rtnl_unlock();
291 return ret;
292 }
293
294 int br_del_bridge(const char *name)
295 {
296 struct net_device *dev;
297 int ret = 0;
298
299 rtnl_lock();
300 dev = __dev_get_by_name(&init_net, name);
301 if (dev == NULL)
302 ret = -ENXIO; /* Could not find device */
303
304 else if (!(dev->priv_flags & IFF_EBRIDGE)) {
305 /* Attempt to delete non bridge device! */
306 ret = -EPERM;
307 }
308
309 else if (dev->flags & IFF_UP) {
310 /* Not shutdown yet. */
311 ret = -EBUSY;
312 }
313
314 else
315 del_br(netdev_priv(dev));
316
317 rtnl_unlock();
318 return ret;
319 }
320
321 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
322 int br_min_mtu(const struct net_bridge *br)
323 {
324 const struct net_bridge_port *p;
325 int mtu = 0;
326
327 ASSERT_RTNL();
328
329 if (list_empty(&br->port_list))
330 mtu = ETH_DATA_LEN;
331 else {
332 list_for_each_entry(p, &br->port_list, list) {
333 if (!mtu || p->dev->mtu < mtu)
334 mtu = p->dev->mtu;
335 }
336 }
337 return mtu;
338 }
339
340 /*
341 * Recomputes features using slave's features
342 */
343 void br_features_recompute(struct net_bridge *br)
344 {
345 struct net_bridge_port *p;
346 unsigned long features;
347
348 features = br->feature_mask;
349
350 list_for_each_entry(p, &br->port_list, list) {
351 features = netdev_compute_features(features, p->dev->features);
352 }
353
354 br->dev->features = features;
355 }
356
357 /* called with RTNL */
358 int br_add_if(struct net_bridge *br, struct net_device *dev)
359 {
360 struct net_bridge_port *p;
361 int err = 0;
362
363 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
364 return -EINVAL;
365
366 if (dev->hard_start_xmit == br_dev_xmit)
367 return -ELOOP;
368
369 if (dev->br_port != NULL)
370 return -EBUSY;
371
372 p = new_nbp(br, dev);
373 if (IS_ERR(p))
374 return PTR_ERR(p);
375
376 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
377 SYSFS_BRIDGE_PORT_ATTR);
378 if (err)
379 goto err0;
380
381 err = br_fdb_insert(br, p, dev->dev_addr);
382 if (err)
383 goto err1;
384
385 err = br_sysfs_addif(p);
386 if (err)
387 goto err2;
388
389 rcu_assign_pointer(dev->br_port, p);
390 dev_set_promiscuity(dev, 1);
391
392 list_add_rcu(&p->list, &br->port_list);
393
394 spin_lock_bh(&br->lock);
395 br_stp_recalculate_bridge_id(br);
396 br_features_recompute(br);
397
398 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
399 (br->dev->flags & IFF_UP))
400 br_stp_enable_port(p);
401 spin_unlock_bh(&br->lock);
402
403 br_ifinfo_notify(RTM_NEWLINK, p);
404
405 dev_set_mtu(br->dev, br_min_mtu(br));
406
407 kobject_uevent(&p->kobj, KOBJ_ADD);
408
409 return 0;
410 err2:
411 br_fdb_delete_by_port(br, p, 1);
412 err1:
413 kobject_del(&p->kobj);
414 return err;
415 err0:
416 kobject_put(&p->kobj);
417 return err;
418 }
419
420 /* called with RTNL */
421 int br_del_if(struct net_bridge *br, struct net_device *dev)
422 {
423 struct net_bridge_port *p = dev->br_port;
424
425 if (!p || p->br != br)
426 return -EINVAL;
427
428 del_nbp(p);
429
430 spin_lock_bh(&br->lock);
431 br_stp_recalculate_bridge_id(br);
432 br_features_recompute(br);
433 spin_unlock_bh(&br->lock);
434
435 return 0;
436 }
437
438 void __exit br_cleanup_bridges(void)
439 {
440 struct net_device *dev, *nxt;
441
442 rtnl_lock();
443 for_each_netdev_safe(&init_net, dev, nxt)
444 if (dev->priv_flags & IFF_EBRIDGE)
445 del_br(dev->priv);
446 rtnl_unlock();
447
448 }
449
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