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1 | /* | |
2 | * Userspace interface | |
3 | * Linux ethernet bridge | |
4 | * | |
5 | * Authors: | |
6 | * Lennert Buytenhek <buytenh@gnu.org> | |
7 | * | |
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/etherdevice.h> | |
17 | #include <linux/netpoll.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 <linux/slab.h> | |
25 | #include <net/sock.h> | |
26 | ||
27 | #include "br_private.h" | |
28 | ||
29 | /* | |
30 | * Determine initial path cost based on speed. | |
31 | * using recommendations from 802.1d standard | |
32 | * | |
33 | * Since driver might sleep need to not be holding any locks. | |
34 | */ | |
35 | static int port_cost(struct net_device *dev) | |
36 | { | |
37 | struct ethtool_cmd ecmd; | |
38 | ||
39 | if (!__ethtool_get_settings(dev, &ecmd)) { | |
40 | switch (ethtool_cmd_speed(&ecmd)) { | |
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 | /* Old silly heuristics based on name */ | |
53 | if (!strncmp(dev->name, "lec", 3)) | |
54 | return 7; | |
55 | ||
56 | if (!strncmp(dev->name, "plip", 4)) | |
57 | return 2500; | |
58 | ||
59 | return 100; /* assume old 10Mbps */ | |
60 | } | |
61 | ||
62 | ||
63 | /* Check for port carrier transistions. */ | |
64 | void br_port_carrier_check(struct net_bridge_port *p) | |
65 | { | |
66 | struct net_device *dev = p->dev; | |
67 | struct net_bridge *br = p->br; | |
68 | ||
69 | if (netif_running(dev) && netif_carrier_ok(dev)) | |
70 | p->path_cost = port_cost(dev); | |
71 | ||
72 | if (!netif_running(br->dev)) | |
73 | return; | |
74 | ||
75 | spin_lock_bh(&br->lock); | |
76 | if (netif_running(dev) && netif_carrier_ok(dev)) { | |
77 | if (p->state == BR_STATE_DISABLED) | |
78 | br_stp_enable_port(p); | |
79 | } else { | |
80 | if (p->state != BR_STATE_DISABLED) | |
81 | br_stp_disable_port(p); | |
82 | } | |
83 | spin_unlock_bh(&br->lock); | |
84 | } | |
85 | ||
86 | static void release_nbp(struct kobject *kobj) | |
87 | { | |
88 | struct net_bridge_port *p | |
89 | = container_of(kobj, struct net_bridge_port, kobj); | |
90 | kfree(p); | |
91 | } | |
92 | ||
93 | static struct kobj_type brport_ktype = { | |
94 | #ifdef CONFIG_SYSFS | |
95 | .sysfs_ops = &brport_sysfs_ops, | |
96 | #endif | |
97 | .release = release_nbp, | |
98 | }; | |
99 | ||
100 | static void destroy_nbp(struct net_bridge_port *p) | |
101 | { | |
102 | struct net_device *dev = p->dev; | |
103 | ||
104 | p->br = NULL; | |
105 | p->dev = NULL; | |
106 | dev_put(dev); | |
107 | ||
108 | kobject_put(&p->kobj); | |
109 | } | |
110 | ||
111 | static void destroy_nbp_rcu(struct rcu_head *head) | |
112 | { | |
113 | struct net_bridge_port *p = | |
114 | container_of(head, struct net_bridge_port, rcu); | |
115 | destroy_nbp(p); | |
116 | } | |
117 | ||
118 | /* Delete port(interface) from bridge is done in two steps. | |
119 | * via RCU. First step, marks device as down. That deletes | |
120 | * all the timers and stops new packets from flowing through. | |
121 | * | |
122 | * Final cleanup doesn't occur until after all CPU's finished | |
123 | * processing packets. | |
124 | * | |
125 | * Protected from multiple admin operations by RTNL mutex | |
126 | */ | |
127 | static void del_nbp(struct net_bridge_port *p) | |
128 | { | |
129 | struct net_bridge *br = p->br; | |
130 | struct net_device *dev = p->dev; | |
131 | ||
132 | sysfs_remove_link(br->ifobj, p->dev->name); | |
133 | ||
134 | dev_set_promiscuity(dev, -1); | |
135 | ||
136 | spin_lock_bh(&br->lock); | |
137 | br_stp_disable_port(p); | |
138 | spin_unlock_bh(&br->lock); | |
139 | ||
140 | br_ifinfo_notify(RTM_DELLINK, p); | |
141 | ||
142 | br_fdb_delete_by_port(br, p, 1); | |
143 | ||
144 | list_del_rcu(&p->list); | |
145 | ||
146 | dev->priv_flags &= ~IFF_BRIDGE_PORT; | |
147 | ||
148 | netdev_rx_handler_unregister(dev); | |
149 | synchronize_net(); | |
150 | ||
151 | netdev_set_master(dev, NULL); | |
152 | ||
153 | br_multicast_del_port(p); | |
154 | ||
155 | kobject_uevent(&p->kobj, KOBJ_REMOVE); | |
156 | kobject_del(&p->kobj); | |
157 | ||
158 | br_netpoll_disable(p); | |
159 | ||
160 | call_rcu(&p->rcu, destroy_nbp_rcu); | |
161 | } | |
162 | ||
163 | /* Delete bridge device */ | |
164 | void br_dev_delete(struct net_device *dev, struct list_head *head) | |
165 | { | |
166 | struct net_bridge *br = netdev_priv(dev); | |
167 | struct net_bridge_port *p, *n; | |
168 | ||
169 | list_for_each_entry_safe(p, n, &br->port_list, list) { | |
170 | del_nbp(p); | |
171 | } | |
172 | ||
173 | del_timer_sync(&br->gc_timer); | |
174 | ||
175 | br_sysfs_delbr(br->dev); | |
176 | unregister_netdevice_queue(br->dev, head); | |
177 | } | |
178 | ||
179 | /* find an available port number */ | |
180 | static int find_portno(struct net_bridge *br) | |
181 | { | |
182 | int index; | |
183 | struct net_bridge_port *p; | |
184 | unsigned long *inuse; | |
185 | ||
186 | inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), | |
187 | GFP_KERNEL); | |
188 | if (!inuse) | |
189 | return -ENOMEM; | |
190 | ||
191 | set_bit(0, inuse); /* zero is reserved */ | |
192 | list_for_each_entry(p, &br->port_list, list) { | |
193 | set_bit(p->port_no, inuse); | |
194 | } | |
195 | index = find_first_zero_bit(inuse, BR_MAX_PORTS); | |
196 | kfree(inuse); | |
197 | ||
198 | return (index >= BR_MAX_PORTS) ? -EXFULL : index; | |
199 | } | |
200 | ||
201 | /* called with RTNL but without bridge lock */ | |
202 | static struct net_bridge_port *new_nbp(struct net_bridge *br, | |
203 | struct net_device *dev) | |
204 | { | |
205 | int index; | |
206 | struct net_bridge_port *p; | |
207 | ||
208 | index = find_portno(br); | |
209 | if (index < 0) | |
210 | return ERR_PTR(index); | |
211 | ||
212 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
213 | if (p == NULL) | |
214 | return ERR_PTR(-ENOMEM); | |
215 | ||
216 | p->br = br; | |
217 | dev_hold(dev); | |
218 | p->dev = dev; | |
219 | p->path_cost = port_cost(dev); | |
220 | p->priority = 0x8000 >> BR_PORT_BITS; | |
221 | p->port_no = index; | |
222 | p->flags = 0; | |
223 | br_init_port(p); | |
224 | p->state = BR_STATE_DISABLED; | |
225 | br_stp_port_timer_init(p); | |
226 | br_multicast_add_port(p); | |
227 | ||
228 | return p; | |
229 | } | |
230 | ||
231 | int br_add_bridge(struct net *net, const char *name) | |
232 | { | |
233 | struct net_device *dev; | |
234 | int res; | |
235 | ||
236 | dev = alloc_netdev(sizeof(struct net_bridge), name, | |
237 | br_dev_setup); | |
238 | ||
239 | if (!dev) | |
240 | return -ENOMEM; | |
241 | ||
242 | dev_net_set(dev, net); | |
243 | ||
244 | res = register_netdev(dev); | |
245 | if (res) | |
246 | free_netdev(dev); | |
247 | return res; | |
248 | } | |
249 | ||
250 | int br_del_bridge(struct net *net, const char *name) | |
251 | { | |
252 | struct net_device *dev; | |
253 | int ret = 0; | |
254 | ||
255 | rtnl_lock(); | |
256 | dev = __dev_get_by_name(net, name); | |
257 | if (dev == NULL) | |
258 | ret = -ENXIO; /* Could not find device */ | |
259 | ||
260 | else if (!(dev->priv_flags & IFF_EBRIDGE)) { | |
261 | /* Attempt to delete non bridge device! */ | |
262 | ret = -EPERM; | |
263 | } | |
264 | ||
265 | else if (dev->flags & IFF_UP) { | |
266 | /* Not shutdown yet. */ | |
267 | ret = -EBUSY; | |
268 | } | |
269 | ||
270 | else | |
271 | br_dev_delete(dev, NULL); | |
272 | ||
273 | rtnl_unlock(); | |
274 | return ret; | |
275 | } | |
276 | ||
277 | /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ | |
278 | int br_min_mtu(const struct net_bridge *br) | |
279 | { | |
280 | const struct net_bridge_port *p; | |
281 | int mtu = 0; | |
282 | ||
283 | ASSERT_RTNL(); | |
284 | ||
285 | if (list_empty(&br->port_list)) | |
286 | mtu = ETH_DATA_LEN; | |
287 | else { | |
288 | list_for_each_entry(p, &br->port_list, list) { | |
289 | if (!mtu || p->dev->mtu < mtu) | |
290 | mtu = p->dev->mtu; | |
291 | } | |
292 | } | |
293 | return mtu; | |
294 | } | |
295 | ||
296 | /* | |
297 | * Recomputes features using slave's features | |
298 | */ | |
299 | netdev_features_t br_features_recompute(struct net_bridge *br, | |
300 | netdev_features_t features) | |
301 | { | |
302 | struct net_bridge_port *p; | |
303 | netdev_features_t mask; | |
304 | ||
305 | if (list_empty(&br->port_list)) | |
306 | return features; | |
307 | ||
308 | mask = features; | |
309 | features &= ~NETIF_F_ONE_FOR_ALL; | |
310 | ||
311 | list_for_each_entry(p, &br->port_list, list) { | |
312 | features = netdev_increment_features(features, | |
313 | p->dev->features, mask); | |
314 | } | |
315 | ||
316 | return features; | |
317 | } | |
318 | ||
319 | /* called with RTNL */ | |
320 | int br_add_if(struct net_bridge *br, struct net_device *dev) | |
321 | { | |
322 | struct net_bridge_port *p; | |
323 | int err = 0; | |
324 | bool changed_addr; | |
325 | ||
326 | /* Don't allow bridging non-ethernet like devices */ | |
327 | if ((dev->flags & IFF_LOOPBACK) || | |
328 | dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || | |
329 | !is_valid_ether_addr(dev->dev_addr)) | |
330 | return -EINVAL; | |
331 | ||
332 | /* No bridging of bridges */ | |
333 | if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) | |
334 | return -ELOOP; | |
335 | ||
336 | /* Device is already being bridged */ | |
337 | if (br_port_exists(dev)) | |
338 | return -EBUSY; | |
339 | ||
340 | /* No bridging devices that dislike that (e.g. wireless) */ | |
341 | if (dev->priv_flags & IFF_DONT_BRIDGE) | |
342 | return -EOPNOTSUPP; | |
343 | ||
344 | p = new_nbp(br, dev); | |
345 | if (IS_ERR(p)) | |
346 | return PTR_ERR(p); | |
347 | ||
348 | call_netdevice_notifiers(NETDEV_JOIN, dev); | |
349 | ||
350 | err = dev_set_promiscuity(dev, 1); | |
351 | if (err) | |
352 | goto put_back; | |
353 | ||
354 | err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), | |
355 | SYSFS_BRIDGE_PORT_ATTR); | |
356 | if (err) | |
357 | goto err1; | |
358 | ||
359 | err = br_sysfs_addif(p); | |
360 | if (err) | |
361 | goto err2; | |
362 | ||
363 | if (br_netpoll_info(br) && ((err = br_netpoll_enable(p)))) | |
364 | goto err3; | |
365 | ||
366 | err = netdev_set_master(dev, br->dev); | |
367 | if (err) | |
368 | goto err3; | |
369 | ||
370 | err = netdev_rx_handler_register(dev, br_handle_frame, p); | |
371 | if (err) | |
372 | goto err4; | |
373 | ||
374 | dev->priv_flags |= IFF_BRIDGE_PORT; | |
375 | ||
376 | dev_disable_lro(dev); | |
377 | ||
378 | list_add_rcu(&p->list, &br->port_list); | |
379 | ||
380 | netdev_update_features(br->dev); | |
381 | ||
382 | spin_lock_bh(&br->lock); | |
383 | changed_addr = br_stp_recalculate_bridge_id(br); | |
384 | ||
385 | if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && | |
386 | (br->dev->flags & IFF_UP)) | |
387 | br_stp_enable_port(p); | |
388 | spin_unlock_bh(&br->lock); | |
389 | ||
390 | br_ifinfo_notify(RTM_NEWLINK, p); | |
391 | ||
392 | if (changed_addr) | |
393 | call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); | |
394 | ||
395 | dev_set_mtu(br->dev, br_min_mtu(br)); | |
396 | ||
397 | if (br_fdb_insert(br, p, dev->dev_addr)) | |
398 | netdev_err(dev, "failed insert local address bridge forwarding table\n"); | |
399 | ||
400 | kobject_uevent(&p->kobj, KOBJ_ADD); | |
401 | ||
402 | return 0; | |
403 | ||
404 | err4: | |
405 | netdev_set_master(dev, NULL); | |
406 | err3: | |
407 | sysfs_remove_link(br->ifobj, p->dev->name); | |
408 | err2: | |
409 | kobject_put(&p->kobj); | |
410 | p = NULL; /* kobject_put frees */ | |
411 | err1: | |
412 | dev_set_promiscuity(dev, -1); | |
413 | put_back: | |
414 | dev_put(dev); | |
415 | kfree(p); | |
416 | return err; | |
417 | } | |
418 | ||
419 | /* called with RTNL */ | |
420 | int br_del_if(struct net_bridge *br, struct net_device *dev) | |
421 | { | |
422 | struct net_bridge_port *p; | |
423 | bool changed_addr; | |
424 | ||
425 | p = br_port_get_rtnl(dev); | |
426 | if (!p || p->br != br) | |
427 | return -EINVAL; | |
428 | ||
429 | del_nbp(p); | |
430 | ||
431 | spin_lock_bh(&br->lock); | |
432 | changed_addr = br_stp_recalculate_bridge_id(br); | |
433 | spin_unlock_bh(&br->lock); | |
434 | ||
435 | if (changed_addr) | |
436 | call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); | |
437 | ||
438 | netdev_update_features(br->dev); | |
439 | ||
440 | return 0; | |
441 | } | |
442 | ||
443 | void __net_exit br_net_exit(struct net *net) | |
444 | { | |
445 | struct net_device *dev; | |
446 | LIST_HEAD(list); | |
447 | ||
448 | rtnl_lock(); | |
449 | for_each_netdev(net, dev) | |
450 | if (dev->priv_flags & IFF_EBRIDGE) | |
451 | br_dev_delete(dev, &list); | |
452 | ||
453 | unregister_netdevice_many(&list); | |
454 | rtnl_unlock(); | |
455 | ||
456 | } |