bridge: Consolidate error paths in br_add_bridge().
[linux-2.6.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  *      $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                         goto out_free;
278         }
279
280         ret = register_netdevice(dev);
281         if (ret)
282                 goto out_free;
283
284         ret = br_sysfs_addbr(dev);
285         if (ret)
286                 unregister_netdevice(dev);
287  out:
288         rtnl_unlock();
289         return ret;
290
291 out_free:
292         free_netdev(dev);
293         goto out;
294 }
295
296 int br_del_bridge(const char *name)
297 {
298         struct net_device *dev;
299         int ret = 0;
300
301         rtnl_lock();
302         dev = __dev_get_by_name(&init_net, name);
303         if (dev == NULL)
304                 ret =  -ENXIO;  /* Could not find device */
305
306         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
307                 /* Attempt to delete non bridge device! */
308                 ret = -EPERM;
309         }
310
311         else if (dev->flags & IFF_UP) {
312                 /* Not shutdown yet. */
313                 ret = -EBUSY;
314         }
315
316         else
317                 del_br(netdev_priv(dev));
318
319         rtnl_unlock();
320         return ret;
321 }
322
323 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
324 int br_min_mtu(const struct net_bridge *br)
325 {
326         const struct net_bridge_port *p;
327         int mtu = 0;
328
329         ASSERT_RTNL();
330
331         if (list_empty(&br->port_list))
332                 mtu = ETH_DATA_LEN;
333         else {
334                 list_for_each_entry(p, &br->port_list, list) {
335                         if (!mtu  || p->dev->mtu < mtu)
336                                 mtu = p->dev->mtu;
337                 }
338         }
339         return mtu;
340 }
341
342 /*
343  * Recomputes features using slave's features
344  */
345 void br_features_recompute(struct net_bridge *br)
346 {
347         struct net_bridge_port *p;
348         unsigned long features;
349
350         features = br->feature_mask;
351
352         list_for_each_entry(p, &br->port_list, list) {
353                 features = netdev_compute_features(features, p->dev->features);
354         }
355
356         br->dev->features = features;
357 }
358
359 /* called with RTNL */
360 int br_add_if(struct net_bridge *br, struct net_device *dev)
361 {
362         struct net_bridge_port *p;
363         int err = 0;
364
365         if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
366                 return -EINVAL;
367
368         if (dev->hard_start_xmit == br_dev_xmit)
369                 return -ELOOP;
370
371         if (dev->br_port != NULL)
372                 return -EBUSY;
373
374         p = new_nbp(br, dev);
375         if (IS_ERR(p))
376                 return PTR_ERR(p);
377
378         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
379                                    SYSFS_BRIDGE_PORT_ATTR);
380         if (err)
381                 goto err0;
382
383         err = br_fdb_insert(br, p, dev->dev_addr);
384         if (err)
385                 goto err1;
386
387         err = br_sysfs_addif(p);
388         if (err)
389                 goto err2;
390
391         rcu_assign_pointer(dev->br_port, p);
392         dev_set_promiscuity(dev, 1);
393
394         list_add_rcu(&p->list, &br->port_list);
395
396         spin_lock_bh(&br->lock);
397         br_stp_recalculate_bridge_id(br);
398         br_features_recompute(br);
399
400         if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
401             (br->dev->flags & IFF_UP))
402                 br_stp_enable_port(p);
403         spin_unlock_bh(&br->lock);
404
405         br_ifinfo_notify(RTM_NEWLINK, p);
406
407         dev_set_mtu(br->dev, br_min_mtu(br));
408
409         kobject_uevent(&p->kobj, KOBJ_ADD);
410
411         return 0;
412 err2:
413         br_fdb_delete_by_port(br, p, 1);
414 err1:
415         kobject_del(&p->kobj);
416         goto put_back;
417 err0:
418         kobject_put(&p->kobj);
419
420 put_back:
421         dev_put(dev);
422         return err;
423 }
424
425 /* called with RTNL */
426 int br_del_if(struct net_bridge *br, struct net_device *dev)
427 {
428         struct net_bridge_port *p = dev->br_port;
429
430         if (!p || p->br != br)
431                 return -EINVAL;
432
433         del_nbp(p);
434
435         spin_lock_bh(&br->lock);
436         br_stp_recalculate_bridge_id(br);
437         br_features_recompute(br);
438         spin_unlock_bh(&br->lock);
439
440         return 0;
441 }
442
443 void __exit br_cleanup_bridges(void)
444 {
445         struct net_device *dev, *nxt;
446
447         rtnl_lock();
448         for_each_netdev_safe(&init_net, dev, nxt)
449                 if (dev->priv_flags & IFF_EBRIDGE)
450                         del_br(dev->priv);
451         rtnl_unlock();
452
453 }