sctp: Follow security requirement of responding with 1 packet
[GitHub/mt8127/android_kernel_alcatel_ttab.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 *
1da177e4
LT
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14#include <linux/kernel.h>
15#include <linux/netdevice.h>
16#include <linux/ethtool.h>
17#include <linux/if_arp.h>
18#include <linux/module.h>
19#include <linux/init.h>
20#include <linux/rtnetlink.h>
46f25dff 21#include <linux/if_ether.h>
1da177e4
LT
22#include <net/sock.h>
23
24#include "br_private.h"
25
26/*
27 * Determine initial path cost based on speed.
28 * using recommendations from 802.1d standard
29 *
61a44b9c 30 * Since driver might sleep need to not be holding any locks.
1da177e4 31 */
4433f420 32static int port_cost(struct net_device *dev)
1da177e4 33{
b4a488d1
SH
34 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
35 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
36
37 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) {
61a44b9c 38 switch(ecmd.speed) {
61a44b9c
MW
39 case SPEED_10000:
40 return 2;
b4a488d1
SH
41 case SPEED_1000:
42 return 4;
43 case SPEED_100:
44 return 19;
61a44b9c
MW
45 case SPEED_10:
46 return 100;
47 }
1da177e4
LT
48 }
49 }
50
51 /* Old silly heuristics based on name */
52 if (!strncmp(dev->name, "lec", 3))
53 return 7;
54
55 if (!strncmp(dev->name, "plip", 4))
56 return 2500;
57
58 return 100; /* assume old 10Mbps */
59}
60
4433f420
SH
61
62/*
63 * Check for port carrier transistions.
64 * Called from work queue to allow for calling functions that
65 * might sleep (such as speed check), and to debounce.
66 */
269def7c 67void br_port_carrier_check(struct net_bridge_port *p)
4433f420 68{
269def7c
SH
69 struct net_device *dev = p->dev;
70 struct net_bridge *br = p->br;
6e86b890
SH
71
72 if (netif_carrier_ok(dev))
73 p->path_cost = port_cost(dev);
74
269def7c 75 if (netif_running(br->dev)) {
6e86b890
SH
76 spin_lock_bh(&br->lock);
77 if (netif_carrier_ok(dev)) {
78 if (p->state == BR_STATE_DISABLED)
79 br_stp_enable_port(p);
80 } else {
81 if (p->state != BR_STATE_DISABLED)
82 br_stp_disable_port(p);
4433f420 83 }
6e86b890 84 spin_unlock_bh(&br->lock);
4433f420 85 }
4433f420
SH
86}
87
bab1deea
SH
88static void release_nbp(struct kobject *kobj)
89{
90 struct net_bridge_port *p
91 = container_of(kobj, struct net_bridge_port, kobj);
92 kfree(p);
93}
94
95static struct kobj_type brport_ktype = {
96#ifdef CONFIG_SYSFS
97 .sysfs_ops = &brport_sysfs_ops,
98#endif
99 .release = release_nbp,
100};
101
1da177e4
LT
102static void destroy_nbp(struct net_bridge_port *p)
103{
104 struct net_device *dev = p->dev;
105
1da177e4
LT
106 p->br = NULL;
107 p->dev = NULL;
108 dev_put(dev);
109
bab1deea 110 kobject_put(&p->kobj);
1da177e4
LT
111}
112
113static void destroy_nbp_rcu(struct rcu_head *head)
114{
115 struct net_bridge_port *p =
116 container_of(head, struct net_bridge_port, rcu);
117 destroy_nbp(p);
118}
119
3f4cfc2d
SH
120/* Delete port(interface) from bridge is done in two steps.
121 * via RCU. First step, marks device as down. That deletes
122 * all the timers and stops new packets from flowing through.
123 *
124 * Final cleanup doesn't occur until after all CPU's finished
125 * processing packets.
126 *
127 * Protected from multiple admin operations by RTNL mutex
128 */
1da177e4
LT
129static void del_nbp(struct net_bridge_port *p)
130{
131 struct net_bridge *br = p->br;
132 struct net_device *dev = p->dev;
133
43b98c4a 134 sysfs_remove_link(br->ifobj, dev->name);
bab1deea 135
1da177e4
LT
136 dev_set_promiscuity(dev, -1);
137
138 spin_lock_bh(&br->lock);
139 br_stp_disable_port(p);
140 spin_unlock_bh(&br->lock);
141
b86c4503
SH
142 br_ifinfo_notify(RTM_DELLINK, p);
143
1a620698 144 br_fdb_delete_by_port(br, p, 1);
1da177e4
LT
145
146 list_del_rcu(&p->list);
147
b3f1be4b
SH
148 rcu_assign_pointer(dev->br_port, NULL);
149
125a12cc 150 kobject_uevent(&p->kobj, KOBJ_REMOVE);
bab1deea
SH
151 kobject_del(&p->kobj);
152
1da177e4
LT
153 call_rcu(&p->rcu, destroy_nbp_rcu);
154}
155
156/* called with RTNL */
157static void del_br(struct net_bridge *br)
158{
159 struct net_bridge_port *p, *n;
160
161 list_for_each_entry_safe(p, n, &br->port_list, list) {
1da177e4
LT
162 del_nbp(p);
163 }
164
165 del_timer_sync(&br->gc_timer);
166
167 br_sysfs_delbr(br->dev);
9d6f229f 168 unregister_netdevice(br->dev);
1da177e4
LT
169}
170
171static struct net_device *new_bridge_dev(const char *name)
172{
173 struct net_bridge *br;
174 struct net_device *dev;
175
176 dev = alloc_netdev(sizeof(struct net_bridge), name,
177 br_dev_setup);
9d6f229f 178
1da177e4
LT
179 if (!dev)
180 return NULL;
181
182 br = netdev_priv(dev);
183 br->dev = dev;
184
185 spin_lock_init(&br->lock);
186 INIT_LIST_HEAD(&br->port_list);
187 spin_lock_init(&br->hash_lock);
188
189 br->bridge_id.prio[0] = 0x80;
190 br->bridge_id.prio[1] = 0x00;
cee48541
SH
191
192 memcpy(br->group_addr, br_group_address, ETH_ALEN);
1da177e4 193
edb5e46f 194 br->feature_mask = dev->features;
9cde0708 195 br->stp_enabled = BR_NO_STP;
1da177e4
LT
196 br->designated_root = br->bridge_id;
197 br->root_path_cost = 0;
198 br->root_port = 0;
199 br->bridge_max_age = br->max_age = 20 * HZ;
200 br->bridge_hello_time = br->hello_time = 2 * HZ;
201 br->bridge_forward_delay = br->forward_delay = 15 * HZ;
202 br->topology_change = 0;
203 br->topology_change_detected = 0;
204 br->ageing_time = 300 * HZ;
205 INIT_LIST_HEAD(&br->age_list);
206
207 br_stp_timer_init(br);
208
209 return dev;
210}
211
212/* find an available port number */
213static int find_portno(struct net_bridge *br)
214{
215 int index;
216 struct net_bridge_port *p;
217 unsigned long *inuse;
218
3b781fa1 219 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
1da177e4
LT
220 GFP_KERNEL);
221 if (!inuse)
222 return -ENOMEM;
223
1da177e4
LT
224 set_bit(0, inuse); /* zero is reserved */
225 list_for_each_entry(p, &br->port_list, list) {
226 set_bit(p->port_no, inuse);
227 }
228 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
229 kfree(inuse);
230
231 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
232}
233
4433f420 234/* called with RTNL but without bridge lock */
9d6f229f 235static struct net_bridge_port *new_nbp(struct net_bridge *br,
4433f420 236 struct net_device *dev)
1da177e4
LT
237{
238 int index;
239 struct net_bridge_port *p;
9d6f229f 240
1da177e4
LT
241 index = find_portno(br);
242 if (index < 0)
243 return ERR_PTR(index);
244
cee48541 245 p = kzalloc(sizeof(*p), GFP_KERNEL);
1da177e4
LT
246 if (p == NULL)
247 return ERR_PTR(-ENOMEM);
248
1da177e4
LT
249 p->br = br;
250 dev_hold(dev);
251 p->dev = dev;
4433f420 252 p->path_cost = port_cost(dev);
9d6f229f 253 p->priority = 0x8000 >> BR_PORT_BITS;
1da177e4
LT
254 p->port_no = index;
255 br_init_port(p);
256 p->state = BR_STATE_DISABLED;
d32439c0 257 br_stp_port_timer_init(p);
1da177e4
LT
258
259 return p;
260}
261
262int br_add_bridge(const char *name)
263{
264 struct net_device *dev;
265 int ret;
266
267 dev = new_bridge_dev(name);
9d6f229f 268 if (!dev)
1da177e4
LT
269 return -ENOMEM;
270
271 rtnl_lock();
272 if (strchr(dev->name, '%')) {
273 ret = dev_alloc_name(dev, dev->name);
e340a90e
PE
274 if (ret < 0)
275 goto out_free;
1da177e4
LT
276 }
277
278 ret = register_netdevice(dev);
e340a90e
PE
279 if (ret)
280 goto out_free;
1da177e4 281
1da177e4 282 ret = br_sysfs_addbr(dev);
ac05202e 283 if (ret)
36485707
JB
284 unregister_netdevice(dev);
285 out:
1da177e4 286 rtnl_unlock();
ac05202e 287 return ret;
e340a90e
PE
288
289out_free:
290 free_netdev(dev);
291 goto out;
1da177e4
LT
292}
293
294int br_del_bridge(const char *name)
295{
296 struct net_device *dev;
297 int ret = 0;
298
299 rtnl_lock();
881d966b 300 dev = __dev_get_by_name(&init_net, name);
9d6f229f 301 if (dev == NULL)
1da177e4
LT
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;
9d6f229f 312 }
1da177e4 313
9d6f229f 314 else
1da177e4
LT
315 del_br(netdev_priv(dev));
316
317 rtnl_unlock();
318 return ret;
319}
320
46f25dff 321/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
1da177e4
LT
322int 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))
46f25dff 330 mtu = ETH_DATA_LEN;
1da177e4
LT
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
81d35307
SH
340/*
341 * Recomputes features using slave's features
342 */
343void br_features_recompute(struct net_bridge *br)
344{
345 struct net_bridge_port *p;
7f353bf2 346 unsigned long features;
81d35307 347
7f353bf2 348 features = br->feature_mask;
81d35307
SH
349
350 list_for_each_entry(p, &br->port_list, list) {
7f353bf2 351 features = netdev_compute_features(features, p->dev->features);
81d35307
SH
352 }
353
7f353bf2 354 br->dev->features = features;
81d35307
SH
355}
356
1da177e4
LT
357/* called with RTNL */
358int 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
bab1deea
SH
372 p = new_nbp(br, dev);
373 if (IS_ERR(p))
1da177e4
LT
374 return PTR_ERR(p);
375
e32cc736
GKH
376 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
377 SYSFS_BRIDGE_PORT_ATTR);
bab1deea
SH
378 if (err)
379 goto err0;
1da177e4 380
9d6f229f 381 err = br_fdb_insert(br, p, dev->dev_addr);
bab1deea
SH
382 if (err)
383 goto err1;
1da177e4 384
bab1deea
SH
385 err = br_sysfs_addif(p);
386 if (err)
387 goto err2;
1da177e4 388
bab1deea
SH
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);
de79059e
AS
397
398 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
399 (br->dev->flags & IFF_UP))
400 br_stp_enable_port(p);
bab1deea
SH
401 spin_unlock_bh(&br->lock);
402
b86c4503
SH
403 br_ifinfo_notify(RTM_NEWLINK, p);
404
bab1deea 405 dev_set_mtu(br->dev, br_min_mtu(br));
269def7c 406
bab1deea 407 kobject_uevent(&p->kobj, KOBJ_ADD);
1da177e4 408
bab1deea
SH
409 return 0;
410err2:
1a620698 411 br_fdb_delete_by_port(br, p, 1);
bab1deea
SH
412err1:
413 kobject_del(&p->kobj);
43af8532 414 goto put_back;
bab1deea
SH
415err0:
416 kobject_put(&p->kobj);
43af8532
VL
417
418put_back:
419 dev_put(dev);
1da177e4
LT
420 return err;
421}
422
423/* called with RTNL */
424int br_del_if(struct net_bridge *br, struct net_device *dev)
425{
426 struct net_bridge_port *p = dev->br_port;
9d6f229f
YH
427
428 if (!p || p->br != br)
1da177e4
LT
429 return -EINVAL;
430
1da177e4
LT
431 del_nbp(p);
432
433 spin_lock_bh(&br->lock);
434 br_stp_recalculate_bridge_id(br);
81d35307 435 br_features_recompute(br);
1da177e4
LT
436 spin_unlock_bh(&br->lock);
437
438 return 0;
439}
440
441void __exit br_cleanup_bridges(void)
442{
443 struct net_device *dev, *nxt;
444
445 rtnl_lock();
881d966b 446 for_each_netdev_safe(&init_net, dev, nxt)
1da177e4
LT
447 if (dev->priv_flags & IFF_EBRIDGE)
448 del_br(dev->priv);
1da177e4
LT
449 rtnl_unlock();
450
451}