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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>
Paul Gortmaker79bb1ee2011-08-29 17:55:05 -040015#include <linux/kmod.h>
Stephen Hemminger6ede2462005-10-25 15:04:59 -070016#include <linux/etherdevice.h>
Stephen Hemminger11dc1f32006-05-25 16:00:12 -070017#include <linux/rtnetlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
19#include "br_private.h"
20#include "br_private_stp.h"
21
22
23/* Port id is composed of priority and port number.
stephen hemminger14f98f22011-04-04 14:03:33 +000024 * NB: some bits of priority are dropped to
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 * make room for more ports.
26 */
27static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
28{
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090029 return ((u16)priority << BR_PORT_BITS)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 | (port_no & ((1<<BR_PORT_BITS)-1));
31}
32
stephen hemminger14f98f22011-04-04 14:03:33 +000033#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035/* called under bridge lock */
36void br_init_port(struct net_bridge_port *p)
37{
38 p->port_id = br_make_port_id(p->priority, p->port_no);
39 br_become_designated_port(p);
40 p->state = BR_STATE_BLOCKING;
41 p->topology_change_ack = 0;
42 p->config_pending = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043}
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);
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090053
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 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
Adrian Drzewiecki78872cc2006-02-15 01:47:48 -080069 spin_lock_bh(&br->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 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;
Adrian Drzewiecki78872cc2006-02-15 01:47:48 -080078 spin_unlock_bh(&br->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
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);
stephen hemminger28a16c92010-05-10 09:31:09 +000091 br_log_state(p);
stephen hemminger4ecb9612011-07-22 07:47:09 +000092 br_ifinfo_notify(RTM_NEWLINK, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093}
94
95/* called under bridge lock */
96void br_stp_disable_port(struct net_bridge_port *p)
97{
stephen hemminger28a16c92010-05-10 09:31:09 +000098 struct net_bridge *br = p->br;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 int wasroot;
100
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 wasroot = br_is_root_bridge(br);
102 br_become_designated_port(p);
103 p->state = BR_STATE_DISABLED;
104 p->topology_change_ack = 0;
105 p->config_pending = 0;
106
Paulius Zaleckas52009592012-03-06 22:25:22 +0000107 br_log_state(p);
stephen hemminger4ecb9612011-07-22 07:47:09 +0000108 br_ifinfo_notify(RTM_NEWLINK, p);
109
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 del_timer(&p->message_age_timer);
111 del_timer(&p->forward_delay_timer);
112 del_timer(&p->hold_timer);
113
Stephen Hemminger1a620692006-10-12 14:45:38 -0700114 br_fdb_delete_by_port(br, p, 0);
Herbert Xu3fe2d7c2010-02-28 00:49:38 -0800115 br_multicast_disable_port(p);
Stephen Hemminger1a620692006-10-12 14:45:38 -0700116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 br_configuration_update(br);
118
119 br_port_state_selection(br);
120
121 if (br_is_root_bridge(br) && !wasroot)
122 br_become_root_bridge(br);
123}
124
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700125static void br_stp_start(struct net_bridge *br)
126{
127 int r;
128 char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
129 char *envp[] = { NULL };
130
Jeremy Fitzhardinge86313c42007-07-17 18:37:03 -0700131 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700132 if (r == 0) {
133 br->stp_enabled = BR_USER_STP;
stephen hemminger28a16c92010-05-10 09:31:09 +0000134 br_debug(br, "userspace STP started\n");
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700135 } else {
136 br->stp_enabled = BR_KERNEL_STP;
stephen hemminger28a16c92010-05-10 09:31:09 +0000137 br_debug(br, "using kernel STP\n");
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700138
139 /* To start timers on any ports left in blocking */
140 spin_lock_bh(&br->lock);
141 br_port_state_selection(br);
142 spin_unlock_bh(&br->lock);
143 }
144}
145
146static void br_stp_stop(struct net_bridge *br)
147{
148 int r;
149 char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
150 char *envp[] = { NULL };
151
152 if (br->stp_enabled == BR_USER_STP) {
Tomas Winkler1a9180a2011-01-03 11:08:58 +0000153 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
stephen hemminger28a16c92010-05-10 09:31:09 +0000154 br_info(br, "userspace STP stopped, return code %d\n", r);
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700155
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);
160 }
161
162 br->stp_enabled = BR_NO_STP;
163}
164
165void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
166{
167 ASSERT_RTNL();
168
169 if (val) {
170 if (br->stp_enabled == BR_NO_STP)
171 br_stp_start(br);
172 } else {
173 if (br->stp_enabled != BR_NO_STP)
174 br_stp_stop(br);
175 }
176}
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178/* called under bridge lock */
Stephen Hemminger4505a3e2005-12-21 18:51:49 -0800179void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Joe Perches9a7b6ef92012-05-08 18:56:49 +0000181 /* should be aligned on 2 bytes for ether_addr_equal() */
Evgeny Kravtsunov19bb3502007-04-17 12:31:24 -0700182 unsigned short oldaddr_aligned[ETH_ALEN >> 1];
183 unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 struct net_bridge_port *p;
185 int wasroot;
186
187 wasroot = br_is_root_bridge(br);
188
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);
192
193 list_for_each_entry(p, &br->port_list, list) {
Joe Perches9a7b6ef92012-05-08 18:56:49 +0000194 if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
196
Joe Perches9a7b6ef92012-05-08 18:56:49 +0000197 if (ether_addr_equal(p->designated_root.addr, oldaddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 memcpy(p->designated_root.addr, addr, ETH_ALEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 }
200
201 br_configuration_update(br);
202 br_port_state_selection(br);
203 if (br_is_root_bridge(br) && !wasroot)
204 br_become_root_bridge(br);
205}
206
Joe Perches9a7b6ef92012-05-08 18:56:49 +0000207/* should be aligned on 2 bytes for ether_addr_equal() */
Evgeny Kravtsunov19bb3502007-04-17 12:31:24 -0700208static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210/* called under bridge lock */
stephen hemmingeredf947f2011-03-24 13:24:01 +0000211bool br_stp_recalculate_bridge_id(struct net_bridge *br)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212{
Evgeny Kravtsunov19bb3502007-04-17 12:31:24 -0700213 const unsigned char *br_mac_zero =
214 (const unsigned char *)br_mac_zero_aligned;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 const unsigned char *addr = br_mac_zero;
216 struct net_bridge_port *p;
217
Stephen Hemminger92c05742008-06-17 16:10:06 -0700218 /* user has chosen a value so keep it */
219 if (br->flags & BR_SET_MAC_ADDR)
Balaji G1459a3c2011-03-29 06:20:04 +0000220 return false;
Stephen Hemminger92c05742008-06-17 16:10:06 -0700221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 list_for_each_entry(p, &br->port_list, list) {
223 if (addr == br_mac_zero ||
Stephen Hemminger554c9a82006-01-03 14:35:54 -0800224 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 addr = p->dev->dev_addr;
226
227 }
228
Joe Perches9a7b6ef92012-05-08 18:56:49 +0000229 if (ether_addr_equal(br->bridge_id.addr, addr))
stephen hemmingeredf947f2011-03-24 13:24:01 +0000230 return false; /* no change */
231
232 br_stp_change_bridge_id(br, addr);
233 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234}
235
236/* called under bridge lock */
237void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
238{
239 struct net_bridge_port *p;
240 int wasroot;
241
242 wasroot = br_is_root_bridge(br);
243
244 list_for_each_entry(p, &br->port_list, list) {
245 if (p->state != BR_STATE_DISABLED &&
246 br_is_designated_port(p)) {
247 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
248 p->designated_bridge.prio[1] = newprio & 0xFF;
249 }
250
251 }
252
253 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
254 br->bridge_id.prio[1] = newprio & 0xFF;
255 br_configuration_update(br);
256 br_port_state_selection(br);
257 if (br_is_root_bridge(br) && !wasroot)
258 br_become_root_bridge(br);
259}
260
261/* called under bridge lock */
stephen hemminger14f98f22011-04-04 14:03:33 +0000262int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263{
stephen hemminger14f98f22011-04-04 14:03:33 +0000264 port_id new_port_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
stephen hemminger14f98f22011-04-04 14:03:33 +0000266 if (newprio > BR_MAX_PORT_PRIORITY)
267 return -ERANGE;
268
269 new_port_id = br_make_port_id(newprio, p->port_no);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 if (br_is_designated_port(p))
271 p->designated_port = new_port_id;
272
273 p->port_id = new_port_id;
274 p->priority = newprio;
275 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
276 p->port_id < p->designated_port) {
277 br_become_designated_port(p);
278 br_port_state_selection(p->br);
279 }
stephen hemminger14f98f22011-04-04 14:03:33 +0000280
281 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282}
283
284/* called under bridge lock */
stephen hemminger14f98f22011-04-04 14:03:33 +0000285int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286{
stephen hemminger14f98f22011-04-04 14:03:33 +0000287 if (path_cost < BR_MIN_PATH_COST ||
288 path_cost > BR_MAX_PATH_COST)
289 return -ERANGE;
290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 p->path_cost = path_cost;
292 br_configuration_update(p->br);
293 br_port_state_selection(p->br);
stephen hemminger14f98f22011-04-04 14:03:33 +0000294 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295}
296
297ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
298{
299 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
300 id->prio[0], id->prio[1],
301 id->addr[0], id->addr[1], id->addr[2],
302 id->addr[3], id->addr[4], id->addr[5]);
303}