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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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14#include <linux/kernel.h>
Stephen Hemminger6ede2462005-10-25 15:04:59 -070015#include <linux/etherdevice.h>
Stephen Hemminger11dc1f32006-05-25 16:00:12 -070016#include <linux/rtnetlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017
18#include "br_private.h"
19#include "br_private_stp.h"
20
21
22/* Port id is composed of priority and port number.
23 * NB: least significant bits of priority are dropped to
24 * make room for more ports.
25 */
26static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
27{
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090028 return ((u16)priority << BR_PORT_BITS)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 | (port_no & ((1<<BR_PORT_BITS)-1));
30}
31
32/* called under bridge lock */
33void br_init_port(struct net_bridge_port *p)
34{
35 p->port_id = br_make_port_id(p->priority, p->port_no);
36 br_become_designated_port(p);
37 p->state = BR_STATE_BLOCKING;
38 p->topology_change_ack = 0;
39 p->config_pending = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040}
41
42/* called under bridge lock */
43void br_stp_enable_bridge(struct net_bridge *br)
44{
45 struct net_bridge_port *p;
46
47 spin_lock_bh(&br->lock);
48 mod_timer(&br->hello_timer, jiffies + br->hello_time);
49 mod_timer(&br->gc_timer, jiffies + HZ/10);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090050
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 br_config_bpdu_generation(br);
52
53 list_for_each_entry(p, &br->port_list, list) {
54 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
55 br_stp_enable_port(p);
56
57 }
58 spin_unlock_bh(&br->lock);
59}
60
61/* NO locks held */
62void br_stp_disable_bridge(struct net_bridge *br)
63{
64 struct net_bridge_port *p;
65
Adrian Drzewiecki78872cc2006-02-15 01:47:48 -080066 spin_lock_bh(&br->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 list_for_each_entry(p, &br->port_list, list) {
68 if (p->state != BR_STATE_DISABLED)
69 br_stp_disable_port(p);
70
71 }
72
73 br->topology_change = 0;
74 br->topology_change_detected = 0;
Adrian Drzewiecki78872cc2006-02-15 01:47:48 -080075 spin_unlock_bh(&br->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77 del_timer_sync(&br->hello_timer);
78 del_timer_sync(&br->topology_change_timer);
79 del_timer_sync(&br->tcn_timer);
80 del_timer_sync(&br->gc_timer);
81}
82
83/* called under bridge lock */
84void br_stp_enable_port(struct net_bridge_port *p)
85{
86 br_init_port(p);
87 br_port_state_selection(p->br);
stephen hemminger28a16c92010-05-10 09:31:09 +000088 br_log_state(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089}
90
91/* called under bridge lock */
92void br_stp_disable_port(struct net_bridge_port *p)
93{
stephen hemminger28a16c92010-05-10 09:31:09 +000094 struct net_bridge *br = p->br;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 int wasroot;
96
stephen hemminger28a16c92010-05-10 09:31:09 +000097 br_log_state(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 wasroot = br_is_root_bridge(br);
100 br_become_designated_port(p);
101 p->state = BR_STATE_DISABLED;
102 p->topology_change_ack = 0;
103 p->config_pending = 0;
104
105 del_timer(&p->message_age_timer);
106 del_timer(&p->forward_delay_timer);
107 del_timer(&p->hold_timer);
108
Stephen Hemminger1a620692006-10-12 14:45:38 -0700109 br_fdb_delete_by_port(br, p, 0);
Herbert Xu3fe2d7c2010-02-28 00:49:38 -0800110 br_multicast_disable_port(p);
Stephen Hemminger1a620692006-10-12 14:45:38 -0700111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 br_configuration_update(br);
113
114 br_port_state_selection(br);
115
116 if (br_is_root_bridge(br) && !wasroot)
117 br_become_root_bridge(br);
118}
119
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700120static void br_stp_start(struct net_bridge *br)
121{
122 int r;
123 char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
124 char *envp[] = { NULL };
125
Jeremy Fitzhardinge86313c42007-07-17 18:37:03 -0700126 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700127 if (r == 0) {
128 br->stp_enabled = BR_USER_STP;
stephen hemminger28a16c92010-05-10 09:31:09 +0000129 br_debug(br, "userspace STP started\n");
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700130 } else {
131 br->stp_enabled = BR_KERNEL_STP;
stephen hemminger28a16c92010-05-10 09:31:09 +0000132 br_debug(br, "using kernel STP\n");
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700133
134 /* To start timers on any ports left in blocking */
135 spin_lock_bh(&br->lock);
136 br_port_state_selection(br);
137 spin_unlock_bh(&br->lock);
138 }
139}
140
141static void br_stp_stop(struct net_bridge *br)
142{
143 int r;
144 char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
145 char *envp[] = { NULL };
146
147 if (br->stp_enabled == BR_USER_STP) {
Tomas Winkler1a9180a2011-01-03 11:08:58 +0000148 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
stephen hemminger28a16c92010-05-10 09:31:09 +0000149 br_info(br, "userspace STP stopped, return code %d\n", r);
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700150
151 /* To start timers on any ports left in blocking */
152 spin_lock_bh(&br->lock);
153 br_port_state_selection(br);
154 spin_unlock_bh(&br->lock);
155 }
156
157 br->stp_enabled = BR_NO_STP;
158}
159
160void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
161{
162 ASSERT_RTNL();
163
164 if (val) {
165 if (br->stp_enabled == BR_NO_STP)
166 br_stp_start(br);
167 } else {
168 if (br->stp_enabled != BR_NO_STP)
169 br_stp_stop(br);
170 }
171}
172
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173/* called under bridge lock */
Stephen Hemminger4505a3e2005-12-21 18:51:49 -0800174void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175{
Evgeny Kravtsunov19bb3502007-04-17 12:31:24 -0700176 /* should be aligned on 2 bytes for compare_ether_addr() */
177 unsigned short oldaddr_aligned[ETH_ALEN >> 1];
178 unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 struct net_bridge_port *p;
180 int wasroot;
181
182 wasroot = br_is_root_bridge(br);
183
184 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
185 memcpy(br->bridge_id.addr, addr, ETH_ALEN);
186 memcpy(br->dev->dev_addr, addr, ETH_ALEN);
187
188 list_for_each_entry(p, &br->port_list, list) {
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700189 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
191
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700192 if (!compare_ether_addr(p->designated_root.addr, oldaddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 memcpy(p->designated_root.addr, addr, ETH_ALEN);
194
195 }
196
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
Evgeny Kravtsunov19bb3502007-04-17 12:31:24 -0700203/* should be aligned on 2 bytes for compare_ether_addr() */
204static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206/* called under bridge lock */
207void br_stp_recalculate_bridge_id(struct net_bridge *br)
208{
Evgeny Kravtsunov19bb3502007-04-17 12:31:24 -0700209 const unsigned char *br_mac_zero =
210 (const unsigned char *)br_mac_zero_aligned;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 const unsigned char *addr = br_mac_zero;
212 struct net_bridge_port *p;
213
Stephen Hemminger92c05742008-06-17 16:10:06 -0700214 /* user has chosen a value so keep it */
215 if (br->flags & BR_SET_MAC_ADDR)
216 return;
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 list_for_each_entry(p, &br->port_list, list) {
219 if (addr == br_mac_zero ||
Stephen Hemminger554c9a82006-01-03 14:35:54 -0800220 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 addr = p->dev->dev_addr;
222
223 }
224
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700225 if (compare_ether_addr(br->bridge_id.addr, addr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 br_stp_change_bridge_id(br, addr);
227}
228
229/* called under bridge lock */
230void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
231{
232 struct net_bridge_port *p;
233 int wasroot;
234
235 wasroot = br_is_root_bridge(br);
236
237 list_for_each_entry(p, &br->port_list, list) {
238 if (p->state != BR_STATE_DISABLED &&
239 br_is_designated_port(p)) {
240 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
241 p->designated_bridge.prio[1] = newprio & 0xFF;
242 }
243
244 }
245
246 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
247 br->bridge_id.prio[1] = newprio & 0xFF;
248 br_configuration_update(br);
249 br_port_state_selection(br);
250 if (br_is_root_bridge(br) && !wasroot)
251 br_become_root_bridge(br);
252}
253
254/* called under bridge lock */
255void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
256{
257 port_id new_port_id = br_make_port_id(newprio, p->port_no);
258
259 if (br_is_designated_port(p))
260 p->designated_port = new_port_id;
261
262 p->port_id = new_port_id;
263 p->priority = newprio;
264 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
265 p->port_id < p->designated_port) {
266 br_become_designated_port(p);
267 br_port_state_selection(p->br);
268 }
269}
270
271/* called under bridge lock */
272void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
273{
274 p->path_cost = path_cost;
275 br_configuration_update(p->br);
276 br_port_state_selection(p->br);
277}
278
279ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
280{
281 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
282 id->prio[0], id->prio[1],
283 id->addr[0], id->addr[1], id->addr[2],
284 id->addr[3], id->addr[4], id->addr[5]);
285}