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/smp_lock.h>
19 #include "br_private.h"
20 #include "br_private_stp.h"
23 /* Port id is composed of priority and port number.
24 * NB: least significant bits of priority are dropped to
25 * make room for more ports.
27 static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
29 return ((u16)priority << BR_PORT_BITS)
30 | (port_no & ((1<<BR_PORT_BITS)-1));
33 /* called under bridge lock */
34 void br_init_port(struct net_bridge_port *p)
36 p->port_id = br_make_port_id(p->priority, p->port_no);
37 br_become_designated_port(p);
38 p->state = BR_STATE_BLOCKING;
39 p->topology_change_ack = 0;
40 p->config_pending = 0;
42 br_stp_port_timer_init(p);
45 /* called under bridge lock */
46 void br_stp_enable_bridge(struct net_bridge *br)
48 struct net_bridge_port *p;
50 spin_lock_bh(&br->lock);
51 mod_timer(&br->hello_timer, jiffies + br->hello_time);
52 br_config_bpdu_generation(br);
54 list_for_each_entry(p, &br->port_list, list) {
55 if (p->dev->flags & IFF_UP)
56 br_stp_enable_port(p);
59 spin_unlock_bh(&br->lock);
63 void br_stp_disable_bridge(struct net_bridge *br)
65 struct net_bridge_port *p;
68 list_for_each_entry(p, &br->port_list, list) {
69 if (p->state != BR_STATE_DISABLED)
70 br_stp_disable_port(p);
74 br->topology_change = 0;
75 br->topology_change_detected = 0;
76 spin_unlock(&br->lock);
78 del_timer_sync(&br->hello_timer);
79 del_timer_sync(&br->topology_change_timer);
80 del_timer_sync(&br->tcn_timer);
83 /* called under bridge lock */
84 void br_stp_enable_port(struct net_bridge_port *p)
87 br_port_state_selection(p->br);
90 /* called under bridge lock */
91 void br_stp_disable_port(struct net_bridge_port *p)
93 struct net_bridge *br;
97 printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
98 br->dev->name, p->port_no, p->dev->name, "disabled");
100 wasroot = br_is_root_bridge(br);
101 br_become_designated_port(p);
102 p->state = BR_STATE_DISABLED;
103 p->topology_change_ack = 0;
104 p->config_pending = 0;
106 del_timer(&p->message_age_timer);
107 del_timer(&p->forward_delay_timer);
108 del_timer(&p->hold_timer);
110 br_configuration_update(br);
112 br_port_state_selection(br);
114 if (br_is_root_bridge(br) && !wasroot)
115 br_become_root_bridge(br);
118 /* called under bridge lock */
119 static void br_stp_change_bridge_id(struct net_bridge *br,
120 const unsigned char *addr)
122 unsigned char oldaddr[6];
123 struct net_bridge_port *p;
126 wasroot = br_is_root_bridge(br);
128 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
129 memcpy(br->bridge_id.addr, addr, ETH_ALEN);
130 memcpy(br->dev->dev_addr, addr, ETH_ALEN);
132 list_for_each_entry(p, &br->port_list, list) {
133 if (!memcmp(p->designated_bridge.addr, oldaddr, ETH_ALEN))
134 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
136 if (!memcmp(p->designated_root.addr, oldaddr, ETH_ALEN))
137 memcpy(p->designated_root.addr, addr, ETH_ALEN);
141 br_configuration_update(br);
142 br_port_state_selection(br);
143 if (br_is_root_bridge(br) && !wasroot)
144 br_become_root_bridge(br);
147 static const unsigned char br_mac_zero[6];
149 /* called under bridge lock */
150 void br_stp_recalculate_bridge_id(struct net_bridge *br)
152 const unsigned char *addr = br_mac_zero;
153 struct net_bridge_port *p;
155 list_for_each_entry(p, &br->port_list, list) {
156 if (addr == br_mac_zero ||
157 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
158 addr = p->dev->dev_addr;
162 if (memcmp(br->bridge_id.addr, addr, ETH_ALEN))
163 br_stp_change_bridge_id(br, addr);
166 /* called under bridge lock */
167 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
169 struct net_bridge_port *p;
172 wasroot = br_is_root_bridge(br);
174 list_for_each_entry(p, &br->port_list, list) {
175 if (p->state != BR_STATE_DISABLED &&
176 br_is_designated_port(p)) {
177 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
178 p->designated_bridge.prio[1] = newprio & 0xFF;
183 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
184 br->bridge_id.prio[1] = newprio & 0xFF;
185 br_configuration_update(br);
186 br_port_state_selection(br);
187 if (br_is_root_bridge(br) && !wasroot)
188 br_become_root_bridge(br);
191 /* called under bridge lock */
192 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
194 port_id new_port_id = br_make_port_id(newprio, p->port_no);
196 if (br_is_designated_port(p))
197 p->designated_port = new_port_id;
199 p->port_id = new_port_id;
200 p->priority = newprio;
201 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
202 p->port_id < p->designated_port) {
203 br_become_designated_port(p);
204 br_port_state_selection(p->br);
208 /* called under bridge lock */
209 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
211 p->path_cost = path_cost;
212 br_configuration_update(p->br);
213 br_port_state_selection(p->br);