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[BRIDGE]: fix crash in STP
[net-next-2.6.git] / net / bridge / br_if.c
CommitLineData
1da177e4
LT
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>
46f25dff 23#include <linux/if_ether.h>
1da177e4
LT
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 * Need to simulate user ioctl because not all device's that support
33 * ethtool, use ethtool_ops. Also, since driver might sleep need to
34 * not be holding any locks.
35 */
4433f420 36static int port_cost(struct net_device *dev)
1da177e4 37{
1da177e4
LT
38 struct ethtool_cmd ecmd = { ETHTOOL_GSET };
39 struct ifreq ifr;
40 mm_segment_t old_fs;
41 int err;
42
43 strncpy(ifr.ifr_name, dev->name, IFNAMSIZ);
44 ifr.ifr_data = (void __user *) &ecmd;
45
46 old_fs = get_fs();
47 set_fs(KERNEL_DS);
48 err = dev_ethtool(&ifr);
49 set_fs(old_fs);
50
51 if (!err) {
52 switch(ecmd.speed) {
53 case SPEED_100:
54 return 19;
55 case SPEED_1000:
56 return 4;
57 case SPEED_10000:
58 return 2;
59 case SPEED_10:
60 return 100;
1da177e4
LT
61 }
62 }
63
64 /* Old silly heuristics based on name */
65 if (!strncmp(dev->name, "lec", 3))
66 return 7;
67
68 if (!strncmp(dev->name, "plip", 4))
69 return 2500;
70
71 return 100; /* assume old 10Mbps */
72}
73
4433f420
SH
74
75/*
76 * Check for port carrier transistions.
77 * Called from work queue to allow for calling functions that
78 * might sleep (such as speed check), and to debounce.
79 */
80static void port_carrier_check(void *arg)
81{
b3f1be4b
SH
82 struct net_device *dev = arg;
83 struct net_bridge_port *p;
6e86b890 84 struct net_bridge *br;
4433f420
SH
85
86 rtnl_lock();
b3f1be4b
SH
87 p = dev->br_port;
88 if (!p)
89 goto done;
6e86b890
SH
90 br = p->br;
91
92 if (netif_carrier_ok(dev))
93 p->path_cost = port_cost(dev);
94
95 if (br->dev->flags & IFF_UP) {
96 spin_lock_bh(&br->lock);
97 if (netif_carrier_ok(dev)) {
98 if (p->state == BR_STATE_DISABLED)
99 br_stp_enable_port(p);
100 } else {
101 if (p->state != BR_STATE_DISABLED)
102 br_stp_disable_port(p);
4433f420 103 }
6e86b890 104 spin_unlock_bh(&br->lock);
4433f420 105 }
b3f1be4b 106done:
4433f420
SH
107 rtnl_unlock();
108}
109
bab1deea
SH
110static void release_nbp(struct kobject *kobj)
111{
112 struct net_bridge_port *p
113 = container_of(kobj, struct net_bridge_port, kobj);
114 kfree(p);
115}
116
117static struct kobj_type brport_ktype = {
118#ifdef CONFIG_SYSFS
119 .sysfs_ops = &brport_sysfs_ops,
120#endif
121 .release = release_nbp,
122};
123
1da177e4
LT
124static void destroy_nbp(struct net_bridge_port *p)
125{
126 struct net_device *dev = p->dev;
127
1da177e4
LT
128 p->br = NULL;
129 p->dev = NULL;
130 dev_put(dev);
131
bab1deea 132 kobject_put(&p->kobj);
1da177e4
LT
133}
134
135static void destroy_nbp_rcu(struct rcu_head *head)
136{
137 struct net_bridge_port *p =
138 container_of(head, struct net_bridge_port, rcu);
139 destroy_nbp(p);
140}
141
3f4cfc2d
SH
142/* Delete port(interface) from bridge is done in two steps.
143 * via RCU. First step, marks device as down. That deletes
144 * all the timers and stops new packets from flowing through.
145 *
146 * Final cleanup doesn't occur until after all CPU's finished
147 * processing packets.
148 *
149 * Protected from multiple admin operations by RTNL mutex
150 */
1da177e4
LT
151static void del_nbp(struct net_bridge_port *p)
152{
153 struct net_bridge *br = p->br;
154 struct net_device *dev = p->dev;
155
bab1deea
SH
156 sysfs_remove_link(&br->ifobj, dev->name);
157
1da177e4
LT
158 dev_set_promiscuity(dev, -1);
159
4433f420 160 cancel_delayed_work(&p->carrier_check);
4433f420 161
1da177e4
LT
162 spin_lock_bh(&br->lock);
163 br_stp_disable_port(p);
164 spin_unlock_bh(&br->lock);
165
166 br_fdb_delete_by_port(br, p);
167
168 list_del_rcu(&p->list);
169
b3f1be4b
SH
170 rcu_assign_pointer(dev->br_port, NULL);
171
bab1deea
SH
172 kobject_del(&p->kobj);
173
1da177e4
LT
174 call_rcu(&p->rcu, destroy_nbp_rcu);
175}
176
177/* called with RTNL */
178static void del_br(struct net_bridge *br)
179{
180 struct net_bridge_port *p, *n;
181
182 list_for_each_entry_safe(p, n, &br->port_list, list) {
1da177e4
LT
183 del_nbp(p);
184 }
185
186 del_timer_sync(&br->gc_timer);
187
188 br_sysfs_delbr(br->dev);
189 unregister_netdevice(br->dev);
190}
191
192static struct net_device *new_bridge_dev(const char *name)
193{
194 struct net_bridge *br;
195 struct net_device *dev;
196
197 dev = alloc_netdev(sizeof(struct net_bridge), name,
198 br_dev_setup);
199
200 if (!dev)
201 return NULL;
202
203 br = netdev_priv(dev);
204 br->dev = dev;
205
206 spin_lock_init(&br->lock);
207 INIT_LIST_HEAD(&br->port_list);
208 spin_lock_init(&br->hash_lock);
209
210 br->bridge_id.prio[0] = 0x80;
211 br->bridge_id.prio[1] = 0x00;
212 memset(br->bridge_id.addr, 0, ETH_ALEN);
213
edb5e46f 214 br->feature_mask = dev->features;
1da177e4
LT
215 br->stp_enabled = 0;
216 br->designated_root = br->bridge_id;
217 br->root_path_cost = 0;
218 br->root_port = 0;
219 br->bridge_max_age = br->max_age = 20 * HZ;
220 br->bridge_hello_time = br->hello_time = 2 * HZ;
221 br->bridge_forward_delay = br->forward_delay = 15 * HZ;
222 br->topology_change = 0;
223 br->topology_change_detected = 0;
224 br->ageing_time = 300 * HZ;
225 INIT_LIST_HEAD(&br->age_list);
226
227 br_stp_timer_init(br);
228
229 return dev;
230}
231
232/* find an available port number */
233static int find_portno(struct net_bridge *br)
234{
235 int index;
236 struct net_bridge_port *p;
237 unsigned long *inuse;
238
239 inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long),
240 GFP_KERNEL);
241 if (!inuse)
242 return -ENOMEM;
243
244 memset(inuse, 0, BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long));
245 set_bit(0, inuse); /* zero is reserved */
246 list_for_each_entry(p, &br->port_list, list) {
247 set_bit(p->port_no, inuse);
248 }
249 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
250 kfree(inuse);
251
252 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
253}
254
4433f420 255/* called with RTNL but without bridge lock */
1da177e4 256static struct net_bridge_port *new_nbp(struct net_bridge *br,
4433f420 257 struct net_device *dev)
1da177e4
LT
258{
259 int index;
260 struct net_bridge_port *p;
261
262 index = find_portno(br);
263 if (index < 0)
264 return ERR_PTR(index);
265
266 p = kmalloc(sizeof(*p), GFP_KERNEL);
267 if (p == NULL)
268 return ERR_PTR(-ENOMEM);
269
270 memset(p, 0, sizeof(*p));
271 p->br = br;
272 dev_hold(dev);
273 p->dev = dev;
4433f420 274 p->path_cost = port_cost(dev);
1da177e4 275 p->priority = 0x8000 >> BR_PORT_BITS;
1da177e4
LT
276 p->port_no = index;
277 br_init_port(p);
278 p->state = BR_STATE_DISABLED;
b3f1be4b 279 INIT_WORK(&p->carrier_check, port_carrier_check, dev);
1da177e4
LT
280 kobject_init(&p->kobj);
281
bab1deea
SH
282 kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR);
283 p->kobj.ktype = &brport_ktype;
284 p->kobj.parent = &(dev->class_dev.kobj);
285 p->kobj.kset = NULL;
286
1da177e4
LT
287 return p;
288}
289
290int br_add_bridge(const char *name)
291{
292 struct net_device *dev;
293 int ret;
294
295 dev = new_bridge_dev(name);
296 if (!dev)
297 return -ENOMEM;
298
299 rtnl_lock();
300 if (strchr(dev->name, '%')) {
301 ret = dev_alloc_name(dev, dev->name);
302 if (ret < 0)
303 goto err1;
304 }
305
306 ret = register_netdevice(dev);
307 if (ret)
308 goto err2;
309
310 /* network device kobject is not setup until
311 * after rtnl_unlock does it's hotplug magic.
312 * so hold reference to avoid race.
313 */
314 dev_hold(dev);
315 rtnl_unlock();
316
317 ret = br_sysfs_addbr(dev);
318 dev_put(dev);
319
320 if (ret)
321 unregister_netdev(dev);
322 out:
323 return ret;
324
325 err2:
326 free_netdev(dev);
327 err1:
328 rtnl_unlock();
329 goto out;
330}
331
332int br_del_bridge(const char *name)
333{
334 struct net_device *dev;
335 int ret = 0;
336
337 rtnl_lock();
338 dev = __dev_get_by_name(name);
339 if (dev == NULL)
340 ret = -ENXIO; /* Could not find device */
341
342 else if (!(dev->priv_flags & IFF_EBRIDGE)) {
343 /* Attempt to delete non bridge device! */
344 ret = -EPERM;
345 }
346
347 else if (dev->flags & IFF_UP) {
348 /* Not shutdown yet. */
349 ret = -EBUSY;
350 }
351
352 else
353 del_br(netdev_priv(dev));
354
355 rtnl_unlock();
356 return ret;
357}
358
46f25dff 359/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
1da177e4
LT
360int br_min_mtu(const struct net_bridge *br)
361{
362 const struct net_bridge_port *p;
363 int mtu = 0;
364
365 ASSERT_RTNL();
366
367 if (list_empty(&br->port_list))
46f25dff 368 mtu = ETH_DATA_LEN;
1da177e4
LT
369 else {
370 list_for_each_entry(p, &br->port_list, list) {
371 if (!mtu || p->dev->mtu < mtu)
372 mtu = p->dev->mtu;
373 }
374 }
375 return mtu;
376}
377
81d35307
SH
378/*
379 * Recomputes features using slave's features
380 */
381void br_features_recompute(struct net_bridge *br)
382{
383 struct net_bridge_port *p;
384 unsigned long features, checksum;
385
edb5e46f
SH
386 features = br->feature_mask &~ NETIF_F_IP_CSUM;
387 checksum = br->feature_mask & NETIF_F_IP_CSUM;
81d35307
SH
388
389 list_for_each_entry(p, &br->port_list, list) {
390 if (!(p->dev->features
391 & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM)))
392 checksum = 0;
393 features &= p->dev->features;
394 }
395
396 br->dev->features = features | checksum | NETIF_F_LLTX;
397}
398
1da177e4
LT
399/* called with RTNL */
400int br_add_if(struct net_bridge *br, struct net_device *dev)
401{
402 struct net_bridge_port *p;
403 int err = 0;
404
405 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
406 return -EINVAL;
407
408 if (dev->hard_start_xmit == br_dev_xmit)
409 return -ELOOP;
410
411 if (dev->br_port != NULL)
412 return -EBUSY;
413
bab1deea
SH
414 p = new_nbp(br, dev);
415 if (IS_ERR(p))
1da177e4
LT
416 return PTR_ERR(p);
417
bab1deea
SH
418 err = kobject_add(&p->kobj);
419 if (err)
420 goto err0;
1da177e4 421
bab1deea
SH
422 err = br_fdb_insert(br, p, dev->dev_addr);
423 if (err)
424 goto err1;
1da177e4 425
bab1deea
SH
426 err = br_sysfs_addif(p);
427 if (err)
428 goto err2;
1da177e4 429
bab1deea
SH
430 rcu_assign_pointer(dev->br_port, p);
431 dev_set_promiscuity(dev, 1);
432
433 list_add_rcu(&p->list, &br->port_list);
434
435 spin_lock_bh(&br->lock);
436 br_stp_recalculate_bridge_id(br);
437 br_features_recompute(br);
438 schedule_delayed_work(&p->carrier_check, BR_PORT_DEBOUNCE);
439 spin_unlock_bh(&br->lock);
440
441 dev_set_mtu(br->dev, br_min_mtu(br));
442 kobject_uevent(&p->kobj, KOBJ_ADD);
1da177e4 443
bab1deea
SH
444 return 0;
445err2:
446 br_fdb_delete_by_port(br, p);
447err1:
448 kobject_del(&p->kobj);
449err0:
450 kobject_put(&p->kobj);
1da177e4
LT
451 return err;
452}
453
454/* called with RTNL */
455int br_del_if(struct net_bridge *br, struct net_device *dev)
456{
457 struct net_bridge_port *p = dev->br_port;
458
459 if (!p || p->br != br)
460 return -EINVAL;
461
1da177e4
LT
462 del_nbp(p);
463
464 spin_lock_bh(&br->lock);
465 br_stp_recalculate_bridge_id(br);
81d35307 466 br_features_recompute(br);
1da177e4
LT
467 spin_unlock_bh(&br->lock);
468
469 return 0;
470}
471
472void __exit br_cleanup_bridges(void)
473{
474 struct net_device *dev, *nxt;
475
476 rtnl_lock();
477 for (dev = dev_base; dev; dev = nxt) {
478 nxt = dev->next;
479 if (dev->priv_flags & IFF_EBRIDGE)
480 del_br(dev->priv);
481 }
482 rtnl_unlock();
483
484}