3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
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.
14 #include <linux/kernel.h>
15 #include <linux/netdevice.h>
16 #include <linux/ethtool.h>
17 #include <linux/if_arp.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/rtnetlink.h>
21 #include <linux/if_ether.h>
22 #include <linux/slab.h>
25 #include "br_private.h"
28 * Determine initial path cost based on speed.
29 * using recommendations from 802.1d standard
31 * Since driver might sleep need to not be holding any locks.
33 static int port_cost(struct net_device *dev)
35 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
36 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
38 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) {
52 /* Old silly heuristics based on name */
53 if (!strncmp(dev->name, "lec", 3))
56 if (!strncmp(dev->name, "plip", 4))
59 return 100; /* assume old 10Mbps */
64 * Check for port carrier transistions.
65 * Called from work queue to allow for calling functions that
66 * might sleep (such as speed check), and to debounce.
68 void br_port_carrier_check(struct net_bridge_port *p)
70 struct net_device *dev = p->dev;
71 struct net_bridge *br = p->br;
73 if (netif_carrier_ok(dev))
74 p->path_cost = port_cost(dev);
76 if (netif_running(br->dev)) {
77 spin_lock_bh(&br->lock);
78 if (netif_carrier_ok(dev)) {
79 if (p->state == BR_STATE_DISABLED)
80 br_stp_enable_port(p);
82 if (p->state != BR_STATE_DISABLED)
83 br_stp_disable_port(p);
85 spin_unlock_bh(&br->lock);
89 static void release_nbp(struct kobject *kobj)
91 struct net_bridge_port *p
92 = container_of(kobj, struct net_bridge_port, kobj);
96 static struct kobj_type brport_ktype = {
98 .sysfs_ops = &brport_sysfs_ops,
100 .release = release_nbp,
103 static void destroy_nbp(struct net_bridge_port *p)
105 struct net_device *dev = p->dev;
111 kobject_put(&p->kobj);
114 static void destroy_nbp_rcu(struct rcu_head *head)
116 struct net_bridge_port *p =
117 container_of(head, struct net_bridge_port, rcu);
121 /* Delete port(interface) from bridge is done in two steps.
122 * via RCU. First step, marks device as down. That deletes
123 * all the timers and stops new packets from flowing through.
125 * Final cleanup doesn't occur until after all CPU's finished
126 * processing packets.
128 * Protected from multiple admin operations by RTNL mutex
130 static void del_nbp(struct net_bridge_port *p)
132 struct net_bridge *br = p->br;
133 struct net_device *dev = p->dev;
135 sysfs_remove_link(br->ifobj, dev->name);
137 dev_set_promiscuity(dev, -1);
139 spin_lock_bh(&br->lock);
140 br_stp_disable_port(p);
141 spin_unlock_bh(&br->lock);
143 br_ifinfo_notify(RTM_DELLINK, p);
145 br_fdb_delete_by_port(br, p, 1);
147 list_del_rcu(&p->list);
149 rcu_assign_pointer(dev->br_port, NULL);
151 br_multicast_del_port(p);
153 kobject_uevent(&p->kobj, KOBJ_REMOVE);
154 kobject_del(&p->kobj);
156 call_rcu(&p->rcu, destroy_nbp_rcu);
159 /* called with RTNL */
160 static void del_br(struct net_bridge *br, struct list_head *head)
162 struct net_bridge_port *p, *n;
164 list_for_each_entry_safe(p, n, &br->port_list, list) {
168 del_timer_sync(&br->gc_timer);
170 br_sysfs_delbr(br->dev);
171 unregister_netdevice_queue(br->dev, head);
174 static struct net_device *new_bridge_dev(struct net *net, const char *name)
176 struct net_bridge *br;
177 struct net_device *dev;
179 dev = alloc_netdev(sizeof(struct net_bridge), name,
184 dev_net_set(dev, net);
186 br = netdev_priv(dev);
189 spin_lock_init(&br->lock);
190 INIT_LIST_HEAD(&br->port_list);
191 spin_lock_init(&br->hash_lock);
193 br->bridge_id.prio[0] = 0x80;
194 br->bridge_id.prio[1] = 0x00;
196 memcpy(br->group_addr, br_group_address, ETH_ALEN);
198 br->feature_mask = dev->features;
199 br->stp_enabled = BR_NO_STP;
200 br->designated_root = br->bridge_id;
201 br->root_path_cost = 0;
203 br->bridge_max_age = br->max_age = 20 * HZ;
204 br->bridge_hello_time = br->hello_time = 2 * HZ;
205 br->bridge_forward_delay = br->forward_delay = 15 * HZ;
206 br->topology_change = 0;
207 br->topology_change_detected = 0;
208 br->ageing_time = 300 * HZ;
210 br_netfilter_rtable_init(br);
212 br_stp_timer_init(br);
213 br_multicast_init(br);
218 /* find an available port number */
219 static int find_portno(struct net_bridge *br)
222 struct net_bridge_port *p;
223 unsigned long *inuse;
225 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
230 set_bit(0, inuse); /* zero is reserved */
231 list_for_each_entry(p, &br->port_list, list) {
232 set_bit(p->port_no, inuse);
234 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
237 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
240 /* called with RTNL but without bridge lock */
241 static struct net_bridge_port *new_nbp(struct net_bridge *br,
242 struct net_device *dev)
245 struct net_bridge_port *p;
247 index = find_portno(br);
249 return ERR_PTR(index);
251 p = kzalloc(sizeof(*p), GFP_KERNEL);
253 return ERR_PTR(-ENOMEM);
258 p->path_cost = port_cost(dev);
259 p->priority = 0x8000 >> BR_PORT_BITS;
263 p->state = BR_STATE_DISABLED;
264 br_stp_port_timer_init(p);
265 br_multicast_add_port(p);
270 static struct device_type br_type = {
274 int br_add_bridge(struct net *net, const char *name)
276 struct net_device *dev;
279 dev = new_bridge_dev(net, name);
284 if (strchr(dev->name, '%')) {
285 ret = dev_alloc_name(dev, dev->name);
290 SET_NETDEV_DEVTYPE(dev, &br_type);
292 ret = register_netdevice(dev);
296 ret = br_sysfs_addbr(dev);
298 unregister_netdevice(dev);
308 int br_del_bridge(struct net *net, const char *name)
310 struct net_device *dev;
314 dev = __dev_get_by_name(net, name);
316 ret = -ENXIO; /* Could not find device */
318 else if (!(dev->priv_flags & IFF_EBRIDGE)) {
319 /* Attempt to delete non bridge device! */
323 else if (dev->flags & IFF_UP) {
324 /* Not shutdown yet. */
329 del_br(netdev_priv(dev), NULL);
335 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
336 int br_min_mtu(const struct net_bridge *br)
338 const struct net_bridge_port *p;
343 if (list_empty(&br->port_list))
346 list_for_each_entry(p, &br->port_list, list) {
347 if (!mtu || p->dev->mtu < mtu)
355 * Recomputes features using slave's features
357 void br_features_recompute(struct net_bridge *br)
359 struct net_bridge_port *p;
360 unsigned long features, mask;
362 features = mask = br->feature_mask;
363 if (list_empty(&br->port_list))
366 features &= ~NETIF_F_ONE_FOR_ALL;
368 list_for_each_entry(p, &br->port_list, list) {
369 features = netdev_increment_features(features,
370 p->dev->features, mask);
374 br->dev->features = netdev_fix_features(features, NULL);
377 /* called with RTNL */
378 int br_add_if(struct net_bridge *br, struct net_device *dev)
380 struct net_bridge_port *p;
383 /* Don't allow bridging non-ethernet like devices */
384 if ((dev->flags & IFF_LOOPBACK) ||
385 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN)
388 /* No bridging of bridges */
389 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
392 /* Device is already being bridged */
393 if (dev->br_port != NULL)
396 /* No bridging devices that dislike that (e.g. wireless) */
397 if (dev->priv_flags & IFF_DONT_BRIDGE)
400 p = new_nbp(br, dev);
404 err = dev_set_promiscuity(dev, 1);
408 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
409 SYSFS_BRIDGE_PORT_ATTR);
413 err = br_fdb_insert(br, p, dev->dev_addr);
417 err = br_sysfs_addif(p);
421 rcu_assign_pointer(dev->br_port, p);
422 dev_disable_lro(dev);
424 list_add_rcu(&p->list, &br->port_list);
426 spin_lock_bh(&br->lock);
427 br_stp_recalculate_bridge_id(br);
428 br_features_recompute(br);
430 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
431 (br->dev->flags & IFF_UP))
432 br_stp_enable_port(p);
433 spin_unlock_bh(&br->lock);
435 br_ifinfo_notify(RTM_NEWLINK, p);
437 dev_set_mtu(br->dev, br_min_mtu(br));
439 kobject_uevent(&p->kobj, KOBJ_ADD);
443 br_fdb_delete_by_port(br, p, 1);
445 kobject_put(&p->kobj);
446 p = NULL; /* kobject_put frees */
448 dev_set_promiscuity(dev, -1);
455 /* called with RTNL */
456 int br_del_if(struct net_bridge *br, struct net_device *dev)
458 struct net_bridge_port *p = dev->br_port;
460 if (!p || p->br != br)
465 spin_lock_bh(&br->lock);
466 br_stp_recalculate_bridge_id(br);
467 br_features_recompute(br);
468 spin_unlock_bh(&br->lock);
473 void __net_exit br_net_exit(struct net *net)
475 struct net_device *dev;
479 for_each_netdev(net, dev)
480 if (dev->priv_flags & IFF_EBRIDGE)
481 del_br(netdev_priv(dev), &list);
483 unregister_netdevice_many(&list);