blob: 0da11ff05fa3a9a9d9c218f9a394735b137fac7f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/smp_lock.h>
18
19#include "br_private.h"
20#include "br_private_stp.h"
21
22
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.
26 */
27static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
28{
29 return ((u16)priority << BR_PORT_BITS)
30 | (port_no & ((1<<BR_PORT_BITS)-1));
31}
32
33/* called under bridge lock */
34void br_init_port(struct net_bridge_port *p)
35{
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;
41
42 br_stp_port_timer_init(p);
43}
44
45/* called under bridge lock */
46void br_stp_enable_bridge(struct net_bridge *br)
47{
48 struct net_bridge_port *p;
49
50 spin_lock_bh(&br->lock);
51 mod_timer(&br->hello_timer, jiffies + br->hello_time);
52 mod_timer(&br->gc_timer, jiffies + HZ/10);
53
54 br_config_bpdu_generation(br);
55
56 list_for_each_entry(p, &br->port_list, list) {
57 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
58 br_stp_enable_port(p);
59
60 }
61 spin_unlock_bh(&br->lock);
62}
63
64/* NO locks held */
65void br_stp_disable_bridge(struct net_bridge *br)
66{
67 struct net_bridge_port *p;
68
69 spin_lock(&br->lock);
70 list_for_each_entry(p, &br->port_list, list) {
71 if (p->state != BR_STATE_DISABLED)
72 br_stp_disable_port(p);
73
74 }
75
76 br->topology_change = 0;
77 br->topology_change_detected = 0;
78 spin_unlock(&br->lock);
79
80 del_timer_sync(&br->hello_timer);
81 del_timer_sync(&br->topology_change_timer);
82 del_timer_sync(&br->tcn_timer);
83 del_timer_sync(&br->gc_timer);
84}
85
86/* called under bridge lock */
87void br_stp_enable_port(struct net_bridge_port *p)
88{
89 br_init_port(p);
90 br_port_state_selection(p->br);
91}
92
93/* called under bridge lock */
94void br_stp_disable_port(struct net_bridge_port *p)
95{
96 struct net_bridge *br;
97 int wasroot;
98
99 br = p->br;
100 printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
101 br->dev->name, p->port_no, p->dev->name, "disabled");
102
103 wasroot = br_is_root_bridge(br);
104 br_become_designated_port(p);
105 p->state = BR_STATE_DISABLED;
106 p->topology_change_ack = 0;
107 p->config_pending = 0;
108
109 del_timer(&p->message_age_timer);
110 del_timer(&p->forward_delay_timer);
111 del_timer(&p->hold_timer);
112
113 br_configuration_update(br);
114
115 br_port_state_selection(br);
116
117 if (br_is_root_bridge(br) && !wasroot)
118 br_become_root_bridge(br);
119}
120
121/* called under bridge lock */
122static void br_stp_change_bridge_id(struct net_bridge *br,
123 const unsigned char *addr)
124{
125 unsigned char oldaddr[6];
126 struct net_bridge_port *p;
127 int wasroot;
128
129 wasroot = br_is_root_bridge(br);
130
131 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
132 memcpy(br->bridge_id.addr, addr, ETH_ALEN);
133 memcpy(br->dev->dev_addr, addr, ETH_ALEN);
134
135 list_for_each_entry(p, &br->port_list, list) {
136 if (!memcmp(p->designated_bridge.addr, oldaddr, ETH_ALEN))
137 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
138
139 if (!memcmp(p->designated_root.addr, oldaddr, ETH_ALEN))
140 memcpy(p->designated_root.addr, addr, ETH_ALEN);
141
142 }
143
144 br_configuration_update(br);
145 br_port_state_selection(br);
146 if (br_is_root_bridge(br) && !wasroot)
147 br_become_root_bridge(br);
148}
149
150static const unsigned char br_mac_zero[6];
151
152/* called under bridge lock */
153void br_stp_recalculate_bridge_id(struct net_bridge *br)
154{
155 const unsigned char *addr = br_mac_zero;
156 struct net_bridge_port *p;
157
158 list_for_each_entry(p, &br->port_list, list) {
159 if (addr == br_mac_zero ||
160 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
161 addr = p->dev->dev_addr;
162
163 }
164
165 if (memcmp(br->bridge_id.addr, addr, ETH_ALEN))
166 br_stp_change_bridge_id(br, addr);
167}
168
169/* called under bridge lock */
170void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
171{
172 struct net_bridge_port *p;
173 int wasroot;
174
175 wasroot = br_is_root_bridge(br);
176
177 list_for_each_entry(p, &br->port_list, list) {
178 if (p->state != BR_STATE_DISABLED &&
179 br_is_designated_port(p)) {
180 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
181 p->designated_bridge.prio[1] = newprio & 0xFF;
182 }
183
184 }
185
186 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
187 br->bridge_id.prio[1] = newprio & 0xFF;
188 br_configuration_update(br);
189 br_port_state_selection(br);
190 if (br_is_root_bridge(br) && !wasroot)
191 br_become_root_bridge(br);
192}
193
194/* called under bridge lock */
195void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
196{
197 port_id new_port_id = br_make_port_id(newprio, p->port_no);
198
199 if (br_is_designated_port(p))
200 p->designated_port = new_port_id;
201
202 p->port_id = new_port_id;
203 p->priority = newprio;
204 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
205 p->port_id < p->designated_port) {
206 br_become_designated_port(p);
207 br_port_state_selection(p->br);
208 }
209}
210
211/* called under bridge lock */
212void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
213{
214 p->path_cost = path_cost;
215 br_configuration_update(p->br);
216 br_port_state_selection(p->br);
217}
218
219ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
220{
221 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
222 id->prio[0], id->prio[1],
223 id->addr[0], id->addr[1], id->addr[2],
224 id->addr[3], id->addr[4], id->addr[5]);
225}