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/netpoll.h>
17 #include <linux/ethtool.h>
18 #include <linux/if_arp.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/rtnetlink.h>
22 #include <linux/if_ether.h>
23 #include <linux/slab.h>
26 #include "br_private.h"
29 * Determine initial path cost based on speed.
30 * using recommendations from 802.1d standard
32 * Since driver might sleep need to not be holding any locks.
34 static int port_cost(struct net_device *dev)
36 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
37 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
39 if (!dev_ethtool_get_settings(dev, &ecmd)) {
40 switch (ethtool_cmd_speed(&ecmd)) {
53 /* Old silly heuristics based on name */
54 if (!strncmp(dev->name, "lec", 3))
57 if (!strncmp(dev->name, "plip", 4))
60 return 100; /* assume old 10Mbps */
64 /* Check for port carrier transistions. */
65 void br_port_carrier_check(struct net_bridge_port *p)
67 struct net_device *dev = p->dev;
68 struct net_bridge *br = p->br;
70 if (netif_running(dev) && netif_carrier_ok(dev))
71 p->path_cost = port_cost(dev);
73 if (!netif_running(br->dev))
76 spin_lock_bh(&br->lock);
77 if (netif_running(dev) && netif_carrier_ok(dev)) {
78 if (p->state == BR_STATE_DISABLED)
79 br_stp_enable_port(p);
81 if (p->state != BR_STATE_DISABLED)
82 br_stp_disable_port(p);
84 spin_unlock_bh(&br->lock);
87 static void release_nbp(struct kobject *kobj)
89 struct net_bridge_port *p
90 = container_of(kobj, struct net_bridge_port, kobj);
94 static struct kobj_type brport_ktype = {
96 .sysfs_ops = &brport_sysfs_ops,
98 .release = release_nbp,
101 static void destroy_nbp(struct net_bridge_port *p)
103 struct net_device *dev = p->dev;
109 kobject_put(&p->kobj);
112 static void destroy_nbp_rcu(struct rcu_head *head)
114 struct net_bridge_port *p =
115 container_of(head, struct net_bridge_port, rcu);
119 /* Delete port(interface) from bridge is done in two steps.
120 * via RCU. First step, marks device as down. That deletes
121 * all the timers and stops new packets from flowing through.
123 * Final cleanup doesn't occur until after all CPU's finished
124 * processing packets.
126 * Protected from multiple admin operations by RTNL mutex
128 static void del_nbp(struct net_bridge_port *p)
130 struct net_bridge *br = p->br;
131 struct net_device *dev = p->dev;
133 sysfs_remove_link(br->ifobj, p->dev->name);
135 dev_set_promiscuity(dev, -1);
137 spin_lock_bh(&br->lock);
138 br_stp_disable_port(p);
139 spin_unlock_bh(&br->lock);
141 br_ifinfo_notify(RTM_DELLINK, p);
143 br_fdb_delete_by_port(br, p, 1);
145 list_del_rcu(&p->list);
147 dev->priv_flags &= ~IFF_BRIDGE_PORT;
149 netdev_rx_handler_unregister(dev);
152 netdev_set_master(dev, NULL);
154 br_multicast_del_port(p);
156 kobject_uevent(&p->kobj, KOBJ_REMOVE);
157 kobject_del(&p->kobj);
159 br_netpoll_disable(p);
161 call_rcu(&p->rcu, destroy_nbp_rcu);
164 /* called with RTNL */
165 static void del_br(struct net_bridge *br, struct list_head *head)
167 struct net_bridge_port *p, *n;
169 list_for_each_entry_safe(p, n, &br->port_list, list) {
173 del_timer_sync(&br->gc_timer);
175 br_sysfs_delbr(br->dev);
176 unregister_netdevice_queue(br->dev, head);
179 /* find an available port number */
180 static int find_portno(struct net_bridge *br)
183 struct net_bridge_port *p;
184 unsigned long *inuse;
186 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
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);
195 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
198 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
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)
206 struct net_bridge_port *p;
208 index = find_portno(br);
210 return ERR_PTR(index);
212 p = kzalloc(sizeof(*p), GFP_KERNEL);
214 return ERR_PTR(-ENOMEM);
219 p->path_cost = port_cost(dev);
220 p->priority = 0x8000 >> BR_PORT_BITS;
224 p->state = BR_STATE_DISABLED;
225 br_stp_port_timer_init(p);
226 br_multicast_add_port(p);
231 int br_add_bridge(struct net *net, const char *name)
233 struct net_device *dev;
235 dev = alloc_netdev(sizeof(struct net_bridge), name,
241 dev_net_set(dev, net);
243 return register_netdev(dev);
246 int br_del_bridge(struct net *net, const char *name)
248 struct net_device *dev;
252 dev = __dev_get_by_name(net, name);
254 ret = -ENXIO; /* Could not find device */
256 else if (!(dev->priv_flags & IFF_EBRIDGE)) {
257 /* Attempt to delete non bridge device! */
261 else if (dev->flags & IFF_UP) {
262 /* Not shutdown yet. */
267 del_br(netdev_priv(dev), NULL);
273 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
274 int br_min_mtu(const struct net_bridge *br)
276 const struct net_bridge_port *p;
281 if (list_empty(&br->port_list))
284 list_for_each_entry(p, &br->port_list, list) {
285 if (!mtu || p->dev->mtu < mtu)
293 * Recomputes features using slave's features
295 u32 br_features_recompute(struct net_bridge *br, u32 features)
297 struct net_bridge_port *p;
300 if (list_empty(&br->port_list))
304 features &= ~NETIF_F_ONE_FOR_ALL;
306 list_for_each_entry(p, &br->port_list, list) {
307 features = netdev_increment_features(features,
308 p->dev->features, mask);
314 /* called with RTNL */
315 int br_add_if(struct net_bridge *br, struct net_device *dev)
317 struct net_bridge_port *p;
321 /* Don't allow bridging non-ethernet like devices */
322 if ((dev->flags & IFF_LOOPBACK) ||
323 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN)
326 /* No bridging of bridges */
327 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
330 /* Device is already being bridged */
331 if (br_port_exists(dev))
334 /* No bridging devices that dislike that (e.g. wireless) */
335 if (dev->priv_flags & IFF_DONT_BRIDGE)
338 p = new_nbp(br, dev);
342 call_netdevice_notifiers(NETDEV_JOIN, dev);
344 err = dev_set_promiscuity(dev, 1);
348 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
349 SYSFS_BRIDGE_PORT_ATTR);
353 err = br_fdb_insert(br, p, dev->dev_addr);
357 err = br_sysfs_addif(p);
361 if (br_netpoll_info(br) && ((err = br_netpoll_enable(p))))
364 err = netdev_set_master(dev, br->dev);
368 err = netdev_rx_handler_register(dev, br_handle_frame, p);
372 dev->priv_flags |= IFF_BRIDGE_PORT;
374 dev_disable_lro(dev);
376 list_add_rcu(&p->list, &br->port_list);
378 netdev_update_features(br->dev);
380 spin_lock_bh(&br->lock);
381 changed_addr = br_stp_recalculate_bridge_id(br);
383 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
384 (br->dev->flags & IFF_UP))
385 br_stp_enable_port(p);
386 spin_unlock_bh(&br->lock);
388 br_ifinfo_notify(RTM_NEWLINK, p);
391 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
393 dev_set_mtu(br->dev, br_min_mtu(br));
395 kobject_uevent(&p->kobj, KOBJ_ADD);
400 netdev_set_master(dev, NULL);
402 sysfs_remove_link(br->ifobj, p->dev->name);
404 br_fdb_delete_by_port(br, p, 1);
406 kobject_put(&p->kobj);
407 p = NULL; /* kobject_put frees */
409 dev_set_promiscuity(dev, -1);
416 /* called with RTNL */
417 int br_del_if(struct net_bridge *br, struct net_device *dev)
419 struct net_bridge_port *p;
421 p = br_port_get_rtnl(dev);
422 if (!p || p->br != br)
427 spin_lock_bh(&br->lock);
428 br_stp_recalculate_bridge_id(br);
429 spin_unlock_bh(&br->lock);
431 netdev_update_features(br->dev);
436 void __net_exit br_net_exit(struct net *net)
438 struct net_device *dev;
442 for_each_netdev(net, dev)
443 if (dev->priv_flags & IFF_EBRIDGE)
444 del_br(netdev_priv(dev), &list);
446 unregister_netdevice_many(&list);