br_if.c revision b4a488d1824a2cc3514f9ee1298d805bd5edc893 
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 */
34static 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 */
69void 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
90static 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
97static struct kobj_type brport_ktype = {
98#ifdef CONFIG_SYSFS
99	.sysfs_ops = &brport_sysfs_ops,
100#endif
101	.release = release_nbp,
102};
103
104static 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
115static 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 */
131static 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 */
159static 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
173static 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 */
215static 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 */
237static 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	kobject_init(&p->kobj);
262	kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR);
263	p->kobj.ktype = &brport_ktype;
264	p->kobj.parent = &(dev->dev.kobj);
265	p->kobj.kset = NULL;
266
267	return p;
268}
269
270int br_add_bridge(const char *name)
271{
272	struct net_device *dev;
273	int ret;
274
275	dev = new_bridge_dev(name);
276	if (!dev)
277		return -ENOMEM;
278
279	rtnl_lock();
280	if (strchr(dev->name, '%')) {
281		ret = dev_alloc_name(dev, dev->name);
282		if (ret < 0) {
283			free_netdev(dev);
284			goto out;
285		}
286	}
287
288	ret = register_netdevice(dev);
289	if (ret)
290		goto out;
291
292	ret = br_sysfs_addbr(dev);
293	if (ret)
294		unregister_netdevice(dev);
295 out:
296	rtnl_unlock();
297	return ret;
298}
299
300int br_del_bridge(const char *name)
301{
302	struct net_device *dev;
303	int ret = 0;
304
305	rtnl_lock();
306	dev = __dev_get_by_name(name);
307	if (dev == NULL)
308		ret =  -ENXIO; 	/* Could not find device */
309
310	else if (!(dev->priv_flags & IFF_EBRIDGE)) {
311		/* Attempt to delete non bridge device! */
312		ret = -EPERM;
313	}
314
315	else if (dev->flags & IFF_UP) {
316		/* Not shutdown yet. */
317		ret = -EBUSY;
318	}
319
320	else
321		del_br(netdev_priv(dev));
322
323	rtnl_unlock();
324	return ret;
325}
326
327/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
328int br_min_mtu(const struct net_bridge *br)
329{
330	const struct net_bridge_port *p;
331	int mtu = 0;
332
333	ASSERT_RTNL();
334
335	if (list_empty(&br->port_list))
336		mtu = ETH_DATA_LEN;
337	else {
338		list_for_each_entry(p, &br->port_list, list) {
339			if (!mtu  || p->dev->mtu < mtu)
340				mtu = p->dev->mtu;
341		}
342	}
343	return mtu;
344}
345
346/*
347 * Recomputes features using slave's features
348 */
349void br_features_recompute(struct net_bridge *br)
350{
351	struct net_bridge_port *p;
352	unsigned long features;
353
354	features = br->feature_mask;
355
356	list_for_each_entry(p, &br->port_list, list) {
357		features = netdev_compute_features(features, p->dev->features);
358	}
359
360	br->dev->features = features;
361}
362
363/* called with RTNL */
364int br_add_if(struct net_bridge *br, struct net_device *dev)
365{
366	struct net_bridge_port *p;
367	int err = 0;
368
369	if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
370		return -EINVAL;
371
372	if (dev->hard_start_xmit == br_dev_xmit)
373		return -ELOOP;
374
375	if (dev->br_port != NULL)
376		return -EBUSY;
377
378	p = new_nbp(br, dev);
379	if (IS_ERR(p))
380		return PTR_ERR(p);
381
382	err = kobject_add(&p->kobj);
383	if (err)
384		goto err0;
385
386	err = br_fdb_insert(br, p, dev->dev_addr);
387	if (err)
388		goto err1;
389
390	err = br_sysfs_addif(p);
391	if (err)
392		goto err2;
393
394	rcu_assign_pointer(dev->br_port, p);
395	dev_set_promiscuity(dev, 1);
396
397	list_add_rcu(&p->list, &br->port_list);
398
399	spin_lock_bh(&br->lock);
400	br_stp_recalculate_bridge_id(br);
401	br_features_recompute(br);
402
403	if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
404	    (br->dev->flags & IFF_UP))
405		br_stp_enable_port(p);
406	spin_unlock_bh(&br->lock);
407
408	br_ifinfo_notify(RTM_NEWLINK, p);
409
410	dev_set_mtu(br->dev, br_min_mtu(br));
411
412	kobject_uevent(&p->kobj, KOBJ_ADD);
413
414	return 0;
415err2:
416	br_fdb_delete_by_port(br, p, 1);
417err1:
418	kobject_del(&p->kobj);
419err0:
420	kobject_put(&p->kobj);
421	return err;
422}
423
424/* called with RTNL */
425int br_del_if(struct net_bridge *br, struct net_device *dev)
426{
427	struct net_bridge_port *p = dev->br_port;
428
429	if (!p || p->br != br)
430		return -EINVAL;
431
432	del_nbp(p);
433
434	spin_lock_bh(&br->lock);
435	br_stp_recalculate_bridge_id(br);
436	br_features_recompute(br);
437	spin_unlock_bh(&br->lock);
438
439	return 0;
440}
441
442void __exit br_cleanup_bridges(void)
443{
444	struct net_device *dev, *nxt;
445
446	rtnl_lock();
447	for_each_netdev_safe(dev, nxt)
448		if (dev->priv_flags & IFF_EBRIDGE)
449			del_br(dev->priv);
450	rtnl_unlock();
451
452}
453