e1144e1617be38814ebb2fb497755cb10b646559
[linux-3.10.git] / net / bridge / br_if.c
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         dev->rtnl_link_ops = &br_link_ops;
244
245         res = register_netdev(dev);
246         if (res)
247                 free_netdev(dev);
248         return res;
249 }
250
251 int br_del_bridge(struct net *net, const char *name)
252 {
253         struct net_device *dev;
254         int ret = 0;
255
256         rtnl_lock();
257         dev = __dev_get_by_name(net, name);
258         if (dev == NULL)
259                 ret =  -ENXIO;  /* Could not find device */
260
261         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
262                 /* Attempt to delete non bridge device! */
263                 ret = -EPERM;
264         }
265
266         else if (dev->flags & IFF_UP) {
267                 /* Not shutdown yet. */
268                 ret = -EBUSY;
269         }
270
271         else
272                 br_dev_delete(dev, NULL);
273
274         rtnl_unlock();
275         return ret;
276 }
277
278 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
279 int br_min_mtu(const struct net_bridge *br)
280 {
281         const struct net_bridge_port *p;
282         int mtu = 0;
283
284         ASSERT_RTNL();
285
286         if (list_empty(&br->port_list))
287                 mtu = ETH_DATA_LEN;
288         else {
289                 list_for_each_entry(p, &br->port_list, list) {
290                         if (!mtu  || p->dev->mtu < mtu)
291                                 mtu = p->dev->mtu;
292                 }
293         }
294         return mtu;
295 }
296
297 /*
298  * Recomputes features using slave's features
299  */
300 netdev_features_t br_features_recompute(struct net_bridge *br,
301         netdev_features_t features)
302 {
303         struct net_bridge_port *p;
304         netdev_features_t mask;
305
306         if (list_empty(&br->port_list))
307                 return features;
308
309         mask = features;
310         features &= ~NETIF_F_ONE_FOR_ALL;
311
312         list_for_each_entry(p, &br->port_list, list) {
313                 features = netdev_increment_features(features,
314                                                      p->dev->features, mask);
315         }
316
317         return features;
318 }
319
320 /* called with RTNL */
321 int br_add_if(struct net_bridge *br, struct net_device *dev)
322 {
323         struct net_bridge_port *p;
324         int err = 0;
325         bool changed_addr;
326
327         /* Don't allow bridging non-ethernet like devices */
328         if ((dev->flags & IFF_LOOPBACK) ||
329             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
330             !is_valid_ether_addr(dev->dev_addr))
331                 return -EINVAL;
332
333         /* No bridging of bridges */
334         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
335                 return -ELOOP;
336
337         /* Device is already being bridged */
338         if (br_port_exists(dev))
339                 return -EBUSY;
340
341         /* No bridging devices that dislike that (e.g. wireless) */
342         if (dev->priv_flags & IFF_DONT_BRIDGE)
343                 return -EOPNOTSUPP;
344
345         p = new_nbp(br, dev);
346         if (IS_ERR(p))
347                 return PTR_ERR(p);
348
349         call_netdevice_notifiers(NETDEV_JOIN, dev);
350
351         err = dev_set_promiscuity(dev, 1);
352         if (err)
353                 goto put_back;
354
355         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
356                                    SYSFS_BRIDGE_PORT_ATTR);
357         if (err)
358                 goto err1;
359
360         err = br_sysfs_addif(p);
361         if (err)
362                 goto err2;
363
364         if (br_netpoll_info(br) && ((err = br_netpoll_enable(p))))
365                 goto err3;
366
367         err = netdev_set_master(dev, br->dev);
368         if (err)
369                 goto err3;
370
371         err = netdev_rx_handler_register(dev, br_handle_frame, p);
372         if (err)
373                 goto err4;
374
375         dev->priv_flags |= IFF_BRIDGE_PORT;
376
377         dev_disable_lro(dev);
378
379         list_add_rcu(&p->list, &br->port_list);
380
381         netdev_update_features(br->dev);
382
383         spin_lock_bh(&br->lock);
384         changed_addr = br_stp_recalculate_bridge_id(br);
385
386         if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
387             (br->dev->flags & IFF_UP))
388                 br_stp_enable_port(p);
389         spin_unlock_bh(&br->lock);
390
391         br_ifinfo_notify(RTM_NEWLINK, p);
392
393         if (changed_addr)
394                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
395
396         dev_set_mtu(br->dev, br_min_mtu(br));
397
398         if (br_fdb_insert(br, p, dev->dev_addr))
399                 netdev_err(dev, "failed insert local address bridge forwarding table\n");
400
401         kobject_uevent(&p->kobj, KOBJ_ADD);
402
403         return 0;
404
405 err4:
406         netdev_set_master(dev, NULL);
407 err3:
408         sysfs_remove_link(br->ifobj, p->dev->name);
409 err2:
410         kobject_put(&p->kobj);
411         p = NULL; /* kobject_put frees */
412 err1:
413         dev_set_promiscuity(dev, -1);
414 put_back:
415         dev_put(dev);
416         kfree(p);
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;
424         bool changed_addr;
425
426         p = br_port_get_rtnl(dev);
427         if (!p || p->br != br)
428                 return -EINVAL;
429
430         del_nbp(p);
431
432         spin_lock_bh(&br->lock);
433         changed_addr = br_stp_recalculate_bridge_id(br);
434         spin_unlock_bh(&br->lock);
435
436         if (changed_addr)
437                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
438
439         netdev_update_features(br->dev);
440
441         return 0;
442 }
443
444 void __net_exit br_net_exit(struct net *net)
445 {
446         struct net_device *dev;
447         LIST_HEAD(list);
448
449         rtnl_lock();
450         for_each_netdev(net, dev)
451                 if (dev->priv_flags & IFF_EBRIDGE)
452                         br_dev_delete(dev, &list);
453
454         unregister_netdevice_many(&list);
455         rtnl_unlock();
456
457 }