2 * Spanning tree protocol; interface code
3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * $Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 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/etherdevice.h>
18 #include <linux/rtnetlink.h>
20 #include "br_private.h"
21 #include "br_private_stp.h"
24 /* Port id is composed of priority and port number.
25 * NB: least significant bits of priority are dropped to
26 * make room for more ports.
28 static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
30 return ((u16)priority << BR_PORT_BITS)
31 | (port_no & ((1<<BR_PORT_BITS)-1));
34 /* called under bridge lock */
35 void br_init_port(struct net_bridge_port *p)
37 p->port_id = br_make_port_id(p->priority, p->port_no);
38 br_become_designated_port(p);
39 p->state = BR_STATE_BLOCKING;
40 p->topology_change_ack = 0;
41 p->config_pending = 0;
44 /* called under bridge lock */
45 void br_stp_enable_bridge(struct net_bridge *br)
47 struct net_bridge_port *p;
49 spin_lock_bh(&br->lock);
50 mod_timer(&br->hello_timer, jiffies + br->hello_time);
51 mod_timer(&br->gc_timer, jiffies + HZ/10);
53 br_config_bpdu_generation(br);
55 list_for_each_entry(p, &br->port_list, list) {
56 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
57 br_stp_enable_port(p);
60 spin_unlock_bh(&br->lock);
64 void br_stp_disable_bridge(struct net_bridge *br)
66 struct net_bridge_port *p;
68 spin_lock_bh(&br->lock);
69 list_for_each_entry(p, &br->port_list, list) {
70 if (p->state != BR_STATE_DISABLED)
71 br_stp_disable_port(p);
75 br->topology_change = 0;
76 br->topology_change_detected = 0;
77 spin_unlock_bh(&br->lock);
79 del_timer_sync(&br->hello_timer);
80 del_timer_sync(&br->topology_change_timer);
81 del_timer_sync(&br->tcn_timer);
82 del_timer_sync(&br->gc_timer);
85 /* called under bridge lock */
86 void br_stp_enable_port(struct net_bridge_port *p)
89 br_port_state_selection(p->br);
92 /* called under bridge lock */
93 void br_stp_disable_port(struct net_bridge_port *p)
95 struct net_bridge *br;
99 printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
100 br->dev->name, p->port_no, p->dev->name, "disabled");
102 wasroot = br_is_root_bridge(br);
103 br_become_designated_port(p);
104 p->state = BR_STATE_DISABLED;
105 p->topology_change_ack = 0;
106 p->config_pending = 0;
108 del_timer(&p->message_age_timer);
109 del_timer(&p->forward_delay_timer);
110 del_timer(&p->hold_timer);
112 br_fdb_delete_by_port(br, p, 0);
114 br_configuration_update(br);
116 br_port_state_selection(br);
118 if (br_is_root_bridge(br) && !wasroot)
119 br_become_root_bridge(br);
122 static void br_stp_start(struct net_bridge *br)
125 char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
126 char *envp[] = { NULL };
128 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
130 br->stp_enabled = BR_USER_STP;
131 printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
133 br->stp_enabled = BR_KERNEL_STP;
134 printk(KERN_INFO "%s: starting userspace STP failed, "
135 "starting kernel STP\n", br->dev->name);
137 /* To start timers on any ports left in blocking */
138 spin_lock_bh(&br->lock);
139 br_port_state_selection(br);
140 spin_unlock_bh(&br->lock);
144 static void br_stp_stop(struct net_bridge *br)
147 char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
148 char *envp[] = { NULL };
150 if (br->stp_enabled == BR_USER_STP) {
151 r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
152 printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
156 /* To start timers on any ports left in blocking */
157 spin_lock_bh(&br->lock);
158 br_port_state_selection(br);
159 spin_unlock_bh(&br->lock);
162 br->stp_enabled = BR_NO_STP;
165 void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
170 if (br->stp_enabled == BR_NO_STP)
173 if (br->stp_enabled != BR_NO_STP)
178 /* called under bridge lock */
179 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
181 /* should be aligned on 2 bytes for compare_ether_addr() */
182 unsigned short oldaddr_aligned[ETH_ALEN >> 1];
183 unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
184 struct net_bridge_port *p;
187 wasroot = br_is_root_bridge(br);
189 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
190 memcpy(br->bridge_id.addr, addr, ETH_ALEN);
191 memcpy(br->dev->dev_addr, addr, ETH_ALEN);
193 list_for_each_entry(p, &br->port_list, list) {
194 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
195 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
197 if (!compare_ether_addr(p->designated_root.addr, oldaddr))
198 memcpy(p->designated_root.addr, addr, ETH_ALEN);
202 br_configuration_update(br);
203 br_port_state_selection(br);
204 if (br_is_root_bridge(br) && !wasroot)
205 br_become_root_bridge(br);
208 /* should be aligned on 2 bytes for compare_ether_addr() */
209 static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
211 /* called under bridge lock */
212 void br_stp_recalculate_bridge_id(struct net_bridge *br)
214 const unsigned char *br_mac_zero =
215 (const unsigned char *)br_mac_zero_aligned;
216 const unsigned char *addr = br_mac_zero;
217 struct net_bridge_port *p;
219 list_for_each_entry(p, &br->port_list, list) {
220 if (addr == br_mac_zero ||
221 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
222 addr = p->dev->dev_addr;
226 if (compare_ether_addr(br->bridge_id.addr, addr))
227 br_stp_change_bridge_id(br, addr);
230 /* called under bridge lock */
231 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
233 struct net_bridge_port *p;
236 wasroot = br_is_root_bridge(br);
238 list_for_each_entry(p, &br->port_list, list) {
239 if (p->state != BR_STATE_DISABLED &&
240 br_is_designated_port(p)) {
241 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
242 p->designated_bridge.prio[1] = newprio & 0xFF;
247 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
248 br->bridge_id.prio[1] = newprio & 0xFF;
249 br_configuration_update(br);
250 br_port_state_selection(br);
251 if (br_is_root_bridge(br) && !wasroot)
252 br_become_root_bridge(br);
255 /* called under bridge lock */
256 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
258 port_id new_port_id = br_make_port_id(newprio, p->port_no);
260 if (br_is_designated_port(p))
261 p->designated_port = new_port_id;
263 p->port_id = new_port_id;
264 p->priority = newprio;
265 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
266 p->port_id < p->designated_port) {
267 br_become_designated_port(p);
268 br_port_state_selection(p->br);
272 /* called under bridge lock */
273 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
275 p->path_cost = path_cost;
276 br_configuration_update(p->br);
277 br_port_state_selection(p->br);
280 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
282 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
283 id->prio[0], id->prio[1],
284 id->addr[0], id->addr[1], id->addr[2],
285 id->addr[3], id->addr[4], id->addr[5]);