3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * $Id: br_if.c,v 1.7 2001/12/24 00:59:55 davem Exp $
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.
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>
26 #include "br_private.h"
29 * Determine initial path cost based on speed.
30 * using recommendations from 802.1d standard
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.
36 static int port_cost(struct net_device *dev)
38 struct ethtool_cmd ecmd = { ETHTOOL_GSET };
43 strncpy(ifr.ifr_name, dev->name, IFNAMSIZ);
44 ifr.ifr_data = (void __user *) &ecmd;
48 err = dev_ethtool(&ifr);
64 /* Old silly heuristics based on name */
65 if (!strncmp(dev->name, "lec", 3))
68 if (!strncmp(dev->name, "plip", 4))
71 return 100; /* assume old 10Mbps */
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.
80 static void port_carrier_check(void *arg)
82 struct net_device *dev = arg;
83 struct net_bridge_port *p;
90 if (netif_carrier_ok(p->dev)) {
91 u32 cost = port_cost(p->dev);
93 spin_lock_bh(&p->br->lock);
94 if (p->state == BR_STATE_DISABLED) {
96 br_stp_enable_port(p);
98 spin_unlock_bh(&p->br->lock);
100 spin_lock_bh(&p->br->lock);
101 if (p->state != BR_STATE_DISABLED)
102 br_stp_disable_port(p);
103 spin_unlock_bh(&p->br->lock);
109 static void destroy_nbp(struct net_bridge_port *p)
111 struct net_device *dev = p->dev;
120 static void destroy_nbp_rcu(struct rcu_head *head)
122 struct net_bridge_port *p =
123 container_of(head, struct net_bridge_port, rcu);
127 /* Delete port(interface) from bridge is done in two steps.
128 * via RCU. First step, marks device as down. That deletes
129 * all the timers and stops new packets from flowing through.
131 * Final cleanup doesn't occur until after all CPU's finished
132 * processing packets.
134 * Protected from multiple admin operations by RTNL mutex
136 static void del_nbp(struct net_bridge_port *p)
138 struct net_bridge *br = p->br;
139 struct net_device *dev = p->dev;
141 dev_set_promiscuity(dev, -1);
143 cancel_delayed_work(&p->carrier_check);
145 spin_lock_bh(&br->lock);
146 br_stp_disable_port(p);
147 spin_unlock_bh(&br->lock);
149 br_fdb_delete_by_port(br, p);
151 list_del_rcu(&p->list);
153 rcu_assign_pointer(dev->br_port, NULL);
155 call_rcu(&p->rcu, destroy_nbp_rcu);
158 /* called with RTNL */
159 static void del_br(struct net_bridge *br)
161 struct net_bridge_port *p, *n;
163 list_for_each_entry_safe(p, n, &br->port_list, list) {
164 br_sysfs_removeif(p);
168 del_timer_sync(&br->gc_timer);
170 br_sysfs_delbr(br->dev);
171 unregister_netdevice(br->dev);
174 static struct net_device *new_bridge_dev(const char *name)
176 struct net_bridge *br;
177 struct net_device *dev;
179 dev = alloc_netdev(sizeof(struct net_bridge), name,
185 br = netdev_priv(dev);
188 spin_lock_init(&br->lock);
189 INIT_LIST_HEAD(&br->port_list);
190 spin_lock_init(&br->hash_lock);
192 br->bridge_id.prio[0] = 0x80;
193 br->bridge_id.prio[1] = 0x00;
194 memset(br->bridge_id.addr, 0, ETH_ALEN);
196 br->feature_mask = dev->features;
198 br->designated_root = br->bridge_id;
199 br->root_path_cost = 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);
209 br_stp_timer_init(br);
214 /* find an available port number */
215 static int find_portno(struct net_bridge *br)
218 struct net_bridge_port *p;
219 unsigned long *inuse;
221 inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long),
226 memset(inuse, 0, BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long));
227 set_bit(0, inuse); /* zero is reserved */
228 list_for_each_entry(p, &br->port_list, list) {
229 set_bit(p->port_no, inuse);
231 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
234 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
237 /* called with RTNL but without bridge lock */
238 static struct net_bridge_port *new_nbp(struct net_bridge *br,
239 struct net_device *dev)
242 struct net_bridge_port *p;
244 index = find_portno(br);
246 return ERR_PTR(index);
248 p = kmalloc(sizeof(*p), GFP_KERNEL);
250 return ERR_PTR(-ENOMEM);
252 memset(p, 0, sizeof(*p));
256 p->path_cost = port_cost(dev);
257 p->priority = 0x8000 >> BR_PORT_BITS;
260 p->state = BR_STATE_DISABLED;
261 INIT_WORK(&p->carrier_check, port_carrier_check, dev);
262 kobject_init(&p->kobj);
267 int br_add_bridge(const char *name)
269 struct net_device *dev;
272 dev = new_bridge_dev(name);
277 if (strchr(dev->name, '%')) {
278 ret = dev_alloc_name(dev, dev->name);
283 ret = register_netdevice(dev);
287 /* network device kobject is not setup until
288 * after rtnl_unlock does it's hotplug magic.
289 * so hold reference to avoid race.
294 ret = br_sysfs_addbr(dev);
298 unregister_netdev(dev);
309 int br_del_bridge(const char *name)
311 struct net_device *dev;
315 dev = __dev_get_by_name(name);
317 ret = -ENXIO; /* Could not find device */
319 else if (!(dev->priv_flags & IFF_EBRIDGE)) {
320 /* Attempt to delete non bridge device! */
324 else if (dev->flags & IFF_UP) {
325 /* Not shutdown yet. */
330 del_br(netdev_priv(dev));
336 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
337 int br_min_mtu(const struct net_bridge *br)
339 const struct net_bridge_port *p;
344 if (list_empty(&br->port_list))
347 list_for_each_entry(p, &br->port_list, list) {
348 if (!mtu || p->dev->mtu < mtu)
356 * Recomputes features using slave's features
358 void br_features_recompute(struct net_bridge *br)
360 struct net_bridge_port *p;
361 unsigned long features, checksum;
363 features = br->feature_mask &~ NETIF_F_IP_CSUM;
364 checksum = br->feature_mask & NETIF_F_IP_CSUM;
366 list_for_each_entry(p, &br->port_list, list) {
367 if (!(p->dev->features
368 & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM)))
370 features &= p->dev->features;
373 br->dev->features = features | checksum | NETIF_F_LLTX;
376 /* called with RTNL */
377 int br_add_if(struct net_bridge *br, struct net_device *dev)
379 struct net_bridge_port *p;
382 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
385 if (dev->hard_start_xmit == br_dev_xmit)
388 if (dev->br_port != NULL)
391 if (IS_ERR(p = new_nbp(br, dev)))
394 if ((err = br_fdb_insert(br, p, dev->dev_addr)))
397 else if ((err = br_sysfs_addif(p)))
400 rcu_assign_pointer(dev->br_port, p);
401 dev_set_promiscuity(dev, 1);
403 list_add_rcu(&p->list, &br->port_list);
405 spin_lock_bh(&br->lock);
406 br_stp_recalculate_bridge_id(br);
407 br_features_recompute(br);
408 if ((br->dev->flags & IFF_UP)
409 && (dev->flags & IFF_UP) && netif_carrier_ok(dev))
410 br_stp_enable_port(p);
411 spin_unlock_bh(&br->lock);
413 dev_set_mtu(br->dev, br_min_mtu(br));
419 /* called with RTNL */
420 int br_del_if(struct net_bridge *br, struct net_device *dev)
422 struct net_bridge_port *p = dev->br_port;
424 if (!p || p->br != br)
427 br_sysfs_removeif(p);
430 spin_lock_bh(&br->lock);
431 br_stp_recalculate_bridge_id(br);
432 br_features_recompute(br);
433 spin_unlock_bh(&br->lock);
438 void __exit br_cleanup_bridges(void)
440 struct net_device *dev, *nxt;
443 for (dev = dev_base; dev; dev = nxt) {
445 if (dev->priv_flags & IFF_EBRIDGE)