690573bbf012fa935747d998613f1883221567f5
[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  * 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  */
36 static int port_cost(struct net_device *dev)
37 {
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;
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
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  */
80 void br_port_carrier_check(struct net_bridge_port *p)
81 {
82         struct net_device *dev = p->dev;
83         struct net_bridge *br = p->br;
84
85         if (netif_carrier_ok(dev))
86                 p->path_cost = port_cost(dev);
87
88         if (netif_running(br->dev)) {
89                 spin_lock_bh(&br->lock);
90                 if (netif_carrier_ok(dev)) {
91                         if (p->state == BR_STATE_DISABLED)
92                                 br_stp_enable_port(p);
93                 } else {
94                         if (p->state != BR_STATE_DISABLED)
95                                 br_stp_disable_port(p);
96                 }
97                 spin_unlock_bh(&br->lock);
98         }
99 }
100
101 static void release_nbp(struct kobject *kobj)
102 {
103         struct net_bridge_port *p
104                 = container_of(kobj, struct net_bridge_port, kobj);
105         kfree(p);
106 }
107
108 static struct kobj_type brport_ktype = {
109 #ifdef CONFIG_SYSFS
110         .sysfs_ops = &brport_sysfs_ops,
111 #endif
112         .release = release_nbp,
113 };
114
115 static void destroy_nbp(struct net_bridge_port *p)
116 {
117         struct net_device *dev = p->dev;
118
119         p->br = NULL;
120         p->dev = NULL;
121         dev_put(dev);
122
123         kobject_put(&p->kobj);
124 }
125
126 static void destroy_nbp_rcu(struct rcu_head *head)
127 {
128         struct net_bridge_port *p =
129                         container_of(head, struct net_bridge_port, rcu);
130         destroy_nbp(p);
131 }
132
133 /* Delete port(interface) from bridge is done in two steps.
134  * via RCU. First step, marks device as down. That deletes
135  * all the timers and stops new packets from flowing through.
136  *
137  * Final cleanup doesn't occur until after all CPU's finished
138  * processing packets.
139  *
140  * Protected from multiple admin operations by RTNL mutex
141  */
142 static void del_nbp(struct net_bridge_port *p)
143 {
144         struct net_bridge *br = p->br;
145         struct net_device *dev = p->dev;
146
147         sysfs_remove_link(&br->ifobj, dev->name);
148
149         dev_set_promiscuity(dev, -1);
150
151         spin_lock_bh(&br->lock);
152         br_stp_disable_port(p);
153         spin_unlock_bh(&br->lock);
154
155         br_ifinfo_notify(RTM_DELLINK, p);
156
157         br_fdb_delete_by_port(br, p, 1);
158
159         list_del_rcu(&p->list);
160
161         rcu_assign_pointer(dev->br_port, NULL);
162
163         kobject_uevent(&p->kobj, KOBJ_REMOVE);
164         kobject_del(&p->kobj);
165
166         call_rcu(&p->rcu, destroy_nbp_rcu);
167 }
168
169 /* called with RTNL */
170 static void del_br(struct net_bridge *br)
171 {
172         struct net_bridge_port *p, *n;
173
174         list_for_each_entry_safe(p, n, &br->port_list, list) {
175                 del_nbp(p);
176         }
177
178         del_timer_sync(&br->gc_timer);
179
180         br_sysfs_delbr(br->dev);
181         unregister_netdevice(br->dev);
182 }
183
184 static struct net_device *new_bridge_dev(const char *name)
185 {
186         struct net_bridge *br;
187         struct net_device *dev;
188
189         dev = alloc_netdev(sizeof(struct net_bridge), name,
190                            br_dev_setup);
191
192         if (!dev)
193                 return NULL;
194
195         br = netdev_priv(dev);
196         br->dev = dev;
197
198         spin_lock_init(&br->lock);
199         INIT_LIST_HEAD(&br->port_list);
200         spin_lock_init(&br->hash_lock);
201
202         br->bridge_id.prio[0] = 0x80;
203         br->bridge_id.prio[1] = 0x00;
204
205         memcpy(br->group_addr, br_group_address, ETH_ALEN);
206
207         br->feature_mask = dev->features;
208         br->stp_enabled = BR_NO_STP;
209         br->designated_root = br->bridge_id;
210         br->root_path_cost = 0;
211         br->root_port = 0;
212         br->bridge_max_age = br->max_age = 20 * HZ;
213         br->bridge_hello_time = br->hello_time = 2 * HZ;
214         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
215         br->topology_change = 0;
216         br->topology_change_detected = 0;
217         br->ageing_time = 300 * HZ;
218         INIT_LIST_HEAD(&br->age_list);
219
220         br_stp_timer_init(br);
221
222         return dev;
223 }
224
225 /* find an available port number */
226 static int find_portno(struct net_bridge *br)
227 {
228         int index;
229         struct net_bridge_port *p;
230         unsigned long *inuse;
231
232         inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
233                         GFP_KERNEL);
234         if (!inuse)
235                 return -ENOMEM;
236
237         set_bit(0, inuse);      /* zero is reserved */
238         list_for_each_entry(p, &br->port_list, list) {
239                 set_bit(p->port_no, inuse);
240         }
241         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
242         kfree(inuse);
243
244         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
245 }
246
247 /* called with RTNL but without bridge lock */
248 static struct net_bridge_port *new_nbp(struct net_bridge *br,
249                                        struct net_device *dev)
250 {
251         int index;
252         struct net_bridge_port *p;
253
254         index = find_portno(br);
255         if (index < 0)
256                 return ERR_PTR(index);
257
258         p = kzalloc(sizeof(*p), GFP_KERNEL);
259         if (p == NULL)
260                 return ERR_PTR(-ENOMEM);
261
262         p->br = br;
263         dev_hold(dev);
264         p->dev = dev;
265         p->path_cost = port_cost(dev);
266         p->priority = 0x8000 >> BR_PORT_BITS;
267         p->port_no = index;
268         br_init_port(p);
269         p->state = BR_STATE_DISABLED;
270         br_stp_port_timer_init(p);
271
272         kobject_init(&p->kobj);
273         kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR);
274         p->kobj.ktype = &brport_ktype;
275         p->kobj.parent = &(dev->dev.kobj);
276         p->kobj.kset = NULL;
277
278         return p;
279 }
280
281 int br_add_bridge(const char *name)
282 {
283         struct net_device *dev;
284         int ret;
285
286         dev = new_bridge_dev(name);
287         if (!dev)
288                 return -ENOMEM;
289
290         rtnl_lock();
291         if (strchr(dev->name, '%')) {
292                 ret = dev_alloc_name(dev, dev->name);
293                 if (ret < 0) {
294                         free_netdev(dev);
295                         goto out;
296                 }
297         }
298
299         ret = register_netdevice(dev);
300         if (ret)
301                 goto out;
302
303         ret = br_sysfs_addbr(dev);
304         if (ret)
305                 unregister_netdevice(dev);
306  out:
307         rtnl_unlock();
308         return ret;
309 }
310
311 int br_del_bridge(const char *name)
312 {
313         struct net_device *dev;
314         int ret = 0;
315
316         rtnl_lock();
317         dev = __dev_get_by_name(name);
318         if (dev == NULL)
319                 ret =  -ENXIO;  /* Could not find device */
320
321         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
322                 /* Attempt to delete non bridge device! */
323                 ret = -EPERM;
324         }
325
326         else if (dev->flags & IFF_UP) {
327                 /* Not shutdown yet. */
328                 ret = -EBUSY;
329         }
330
331         else
332                 del_br(netdev_priv(dev));
333
334         rtnl_unlock();
335         return ret;
336 }
337
338 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
339 int br_min_mtu(const struct net_bridge *br)
340 {
341         const struct net_bridge_port *p;
342         int mtu = 0;
343
344         ASSERT_RTNL();
345
346         if (list_empty(&br->port_list))
347                 mtu = ETH_DATA_LEN;
348         else {
349                 list_for_each_entry(p, &br->port_list, list) {
350                         if (!mtu  || p->dev->mtu < mtu)
351                                 mtu = p->dev->mtu;
352                 }
353         }
354         return mtu;
355 }
356
357 /*
358  * Recomputes features using slave's features
359  */
360 void br_features_recompute(struct net_bridge *br)
361 {
362         struct net_bridge_port *p;
363         unsigned long features, checksum;
364
365         checksum = br->feature_mask & NETIF_F_ALL_CSUM ? NETIF_F_NO_CSUM : 0;
366         features = br->feature_mask & ~NETIF_F_ALL_CSUM;
367
368         list_for_each_entry(p, &br->port_list, list) {
369                 unsigned long feature = p->dev->features;
370
371                 if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM))
372                         checksum ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM;
373                 if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM))
374                         checksum ^= NETIF_F_HW_CSUM | NETIF_F_IP_CSUM;
375                 if (!(feature & NETIF_F_IP_CSUM))
376                         checksum = 0;
377
378                 if (feature & NETIF_F_GSO)
379                         feature |= NETIF_F_GSO_SOFTWARE;
380                 feature |= NETIF_F_GSO;
381
382                 features &= feature;
383         }
384
385         if (!(checksum & NETIF_F_ALL_CSUM))
386                 features &= ~NETIF_F_SG;
387         if (!(features & NETIF_F_SG))
388                 features &= ~NETIF_F_GSO_MASK;
389
390         br->dev->features = features | checksum | NETIF_F_LLTX |
391                             NETIF_F_GSO_ROBUST;
392 }
393
394 /* called with RTNL */
395 int br_add_if(struct net_bridge *br, struct net_device *dev)
396 {
397         struct net_bridge_port *p;
398         int err = 0;
399
400         if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
401                 return -EINVAL;
402
403         if (dev->hard_start_xmit == br_dev_xmit)
404                 return -ELOOP;
405
406         if (dev->br_port != NULL)
407                 return -EBUSY;
408
409         p = new_nbp(br, dev);
410         if (IS_ERR(p))
411                 return PTR_ERR(p);
412
413         err = kobject_add(&p->kobj);
414         if (err)
415                 goto err0;
416
417         err = br_fdb_insert(br, p, dev->dev_addr);
418         if (err)
419                 goto err1;
420
421         err = br_sysfs_addif(p);
422         if (err)
423                 goto err2;
424
425         rcu_assign_pointer(dev->br_port, p);
426         dev_set_promiscuity(dev, 1);
427
428         list_add_rcu(&p->list, &br->port_list);
429
430         spin_lock_bh(&br->lock);
431         br_stp_recalculate_bridge_id(br);
432         br_features_recompute(br);
433
434         if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
435             (br->dev->flags & IFF_UP))
436                 br_stp_enable_port(p);
437         spin_unlock_bh(&br->lock);
438
439         br_ifinfo_notify(RTM_NEWLINK, p);
440
441         dev_set_mtu(br->dev, br_min_mtu(br));
442
443         kobject_uevent(&p->kobj, KOBJ_ADD);
444
445         return 0;
446 err2:
447         br_fdb_delete_by_port(br, p, 1);
448 err1:
449         kobject_del(&p->kobj);
450 err0:
451         kobject_put(&p->kobj);
452         return err;
453 }
454
455 /* called with RTNL */
456 int br_del_if(struct net_bridge *br, struct net_device *dev)
457 {
458         struct net_bridge_port *p = dev->br_port;
459
460         if (!p || p->br != br)
461                 return -EINVAL;
462
463         del_nbp(p);
464
465         spin_lock_bh(&br->lock);
466         br_stp_recalculate_bridge_id(br);
467         br_features_recompute(br);
468         spin_unlock_bh(&br->lock);
469
470         return 0;
471 }
472
473 void __exit br_cleanup_bridges(void)
474 {
475         struct net_device *dev, *nxt;
476
477         rtnl_lock();
478         for (dev = dev_base; dev; dev = nxt) {
479                 nxt = dev->next;
480                 if (dev->priv_flags & IFF_EBRIDGE)
481                         del_br(dev->priv);
482         }
483         rtnl_unlock();
484
485 }