File: /usr/src/linux/net/bridge/br_stp_if.c
1 /*
2 * Spanning tree protocol; interface code
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
8 * $Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 davem Exp $
9 *
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.
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/if_bridge.h>
18 #include <linux/smp_lock.h>
19 #include <asm/uaccess.h>
20 #include "br_private.h"
21 #include "br_private_stp.h"
22
23 __u16 br_make_port_id(struct net_bridge_port *p)
24 {
25 return (p->priority << 8) | p->port_no;
26 }
27
28 /* called under bridge lock */
29 void br_init_port(struct net_bridge_port *p)
30 {
31 p->port_id = br_make_port_id(p);
32 br_become_designated_port(p);
33 p->state = BR_STATE_BLOCKING;
34 p->topology_change_ack = 0;
35 p->config_pending = 0;
36 br_timer_clear(&p->message_age_timer);
37 br_timer_clear(&p->forward_delay_timer);
38 br_timer_clear(&p->hold_timer);
39 }
40
41 /* called under bridge lock */
42 void br_stp_enable_bridge(struct net_bridge *br)
43 {
44 struct net_bridge_port *p;
45 struct timer_list *timer = &br->tick;
46
47 init_timer(timer);
48 timer->data = (unsigned long) br;
49 timer->function = br_tick;
50 timer->expires = jiffies + 1;
51 add_timer(timer);
52
53 br_timer_set(&br->hello_timer, jiffies);
54 br_config_bpdu_generation(br);
55
56 p = br->port_list;
57 while (p != NULL) {
58 if (p->dev->flags & IFF_UP)
59 br_stp_enable_port(p);
60
61 p = p->next;
62 }
63
64 br_timer_set(&br->gc_timer, jiffies);
65 }
66
67 /* called under bridge lock */
68 void br_stp_disable_bridge(struct net_bridge *br)
69 {
70 struct net_bridge_port *p;
71
72 br->topology_change = 0;
73 br->topology_change_detected = 0;
74 br_timer_clear(&br->hello_timer);
75 br_timer_clear(&br->topology_change_timer);
76 br_timer_clear(&br->tcn_timer);
77 br_timer_clear(&br->gc_timer);
78 br_fdb_cleanup(br);
79
80 p = br->port_list;
81 while (p != NULL) {
82 if (p->state != BR_STATE_DISABLED)
83 br_stp_disable_port(p);
84
85 p = p->next;
86 }
87
88 del_timer(&br->tick);
89 }
90
91 /* called under bridge lock */
92 void br_stp_enable_port(struct net_bridge_port *p)
93 {
94 br_init_port(p);
95 br_port_state_selection(p->br);
96 }
97
98 /* called under bridge lock */
99 void br_stp_disable_port(struct net_bridge_port *p)
100 {
101 struct net_bridge *br;
102 int wasroot;
103
104 br = p->br;
105 printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
106 br->dev.name, p->port_no, p->dev->name, "disabled");
107
108 wasroot = br_is_root_bridge(br);
109 br_become_designated_port(p);
110 p->state = BR_STATE_DISABLED;
111 p->topology_change_ack = 0;
112 p->config_pending = 0;
113 br_timer_clear(&p->message_age_timer);
114 br_timer_clear(&p->forward_delay_timer);
115 br_timer_clear(&p->hold_timer);
116 br_configuration_update(br);
117 br_port_state_selection(br);
118
119 if (br_is_root_bridge(br) && !wasroot)
120 br_become_root_bridge(br);
121 }
122
123 /* called under bridge lock */
124 static void br_stp_change_bridge_id(struct net_bridge *br, unsigned char *addr)
125 {
126 unsigned char oldaddr[6];
127 struct net_bridge_port *p;
128 int wasroot;
129
130 wasroot = br_is_root_bridge(br);
131
132 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
133 memcpy(br->bridge_id.addr, addr, ETH_ALEN);
134 memcpy(br->dev.dev_addr, addr, ETH_ALEN);
135
136 p = br->port_list;
137 while (p != NULL) {
138 if (!memcmp(p->designated_bridge.addr, oldaddr, ETH_ALEN))
139 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
140
141 if (!memcmp(p->designated_root.addr, oldaddr, ETH_ALEN))
142 memcpy(p->designated_root.addr, addr, ETH_ALEN);
143
144 p = p->next;
145 }
146
147 br_configuration_update(br);
148 br_port_state_selection(br);
149 if (br_is_root_bridge(br) && !wasroot)
150 br_become_root_bridge(br);
151 }
152
153 static unsigned char br_mac_zero[6] = {0,0,0,0,0,0};
154
155 /* called under bridge lock */
156 void br_stp_recalculate_bridge_id(struct net_bridge *br)
157 {
158 unsigned char *addr;
159 struct net_bridge_port *p;
160
161 addr = br_mac_zero;
162
163 p = br->port_list;
164 while (p != NULL) {
165 if (addr == br_mac_zero ||
166 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
167 addr = p->dev->dev_addr;
168
169 p = p->next;
170 }
171
172 if (memcmp(br->bridge_id.addr, addr, ETH_ALEN))
173 br_stp_change_bridge_id(br, addr);
174 }
175
176 /* called under bridge lock */
177 void br_stp_set_bridge_priority(struct net_bridge *br, int newprio)
178 {
179 struct net_bridge_port *p;
180 int wasroot;
181
182 wasroot = br_is_root_bridge(br);
183
184 p = br->port_list;
185 while (p != NULL) {
186 if (p->state != BR_STATE_DISABLED &&
187 br_is_designated_port(p)) {
188 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
189 p->designated_bridge.prio[1] = newprio & 0xFF;
190 }
191
192 p = p->next;
193 }
194
195 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
196 br->bridge_id.prio[1] = newprio & 0xFF;
197 br_configuration_update(br);
198 br_port_state_selection(br);
199 if (br_is_root_bridge(br) && !wasroot)
200 br_become_root_bridge(br);
201 }
202
203 /* called under bridge lock */
204 void br_stp_set_port_priority(struct net_bridge_port *p, int newprio)
205 {
206 __u16 new_port_id;
207
208 p->priority = newprio & 0xFF;
209 new_port_id = br_make_port_id(p);
210
211 if (br_is_designated_port(p))
212 p->designated_port = new_port_id;
213
214 p->port_id = new_port_id;
215 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
216 p->port_id < p->designated_port) {
217 br_become_designated_port(p);
218 br_port_state_selection(p->br);
219 }
220 }
221
222 /* called under bridge lock */
223 void br_stp_set_path_cost(struct net_bridge_port *p, int path_cost)
224 {
225 p->path_cost = path_cost;
226 br_configuration_update(p->br);
227 br_port_state_selection(p->br);
228 }
229