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>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
21 #include "br_private.h"
22 #include "br_private_stp.h"
25 /* Port id is composed of priority and port number.
26 * NB: least significant bits of priority are dropped to
27 * make room for more ports.
29 static inline port_id
br_make_port_id(__u8 priority
, __u16 port_no
)
31 return ((u16
)priority
<< BR_PORT_BITS
)
32 | (port_no
& ((1<<BR_PORT_BITS
)-1));
35 /* called under bridge lock */
36 void br_init_port(struct net_bridge_port
*p
)
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;
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 mod_timer(&br
->gc_timer
, jiffies
+ HZ
/10);
54 br_config_bpdu_generation(br
);
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
);
61 spin_unlock_bh(&br
->lock
);
65 void br_stp_disable_bridge(struct net_bridge
*br
)
67 struct net_bridge_port
*p
;
69 spin_lock_bh(&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
);
76 br
->topology_change
= 0;
77 br
->topology_change_detected
= 0;
78 spin_unlock_bh(&br
->lock
);
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
);
86 /* called under bridge lock */
87 void br_stp_enable_port(struct net_bridge_port
*p
)
90 br_port_state_selection(p
->br
);
93 /* called under bridge lock */
94 void br_stp_disable_port(struct net_bridge_port
*p
)
96 struct net_bridge
*br
;
100 printk(KERN_INFO
"%s: port %i(%s) entering %s state\n",
101 br
->dev
->name
, p
->port_no
, p
->dev
->name
, "disabled");
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;
109 del_timer(&p
->message_age_timer
);
110 del_timer(&p
->forward_delay_timer
);
111 del_timer(&p
->hold_timer
);
113 br_fdb_delete_by_port(br
, p
, 0);
115 br_configuration_update(br
);
117 br_port_state_selection(br
);
119 if (br_is_root_bridge(br
) && !wasroot
)
120 br_become_root_bridge(br
);
123 static void br_stp_start(struct net_bridge
*br
)
126 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "start", NULL
};
127 char *envp
[] = { NULL
};
129 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, 1);
131 br
->stp_enabled
= BR_USER_STP
;
132 printk(KERN_INFO
"%s: userspace STP started\n", br
->dev
->name
);
134 br
->stp_enabled
= BR_KERNEL_STP
;
135 printk(KERN_INFO
"%s: starting userspace STP failed, "
136 "staring kernel STP\n", br
->dev
->name
);
138 /* To start timers on any ports left in blocking */
139 spin_lock_bh(&br
->lock
);
140 br_port_state_selection(br
);
141 spin_unlock_bh(&br
->lock
);
145 static void br_stp_stop(struct net_bridge
*br
)
148 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "stop", NULL
};
149 char *envp
[] = { NULL
};
151 if (br
->stp_enabled
== BR_USER_STP
) {
152 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, 1);
153 printk(KERN_INFO
"%s: userspace STP stopped, return code %d\n",
157 /* To start timers on any ports left in blocking */
158 spin_lock_bh(&br
->lock
);
159 br_port_state_selection(br
);
160 spin_unlock_bh(&br
->lock
);
163 br
->stp_enabled
= BR_NO_STP
;
166 void br_stp_set_enabled(struct net_bridge
*br
, unsigned long val
)
171 if (br
->stp_enabled
== BR_NO_STP
)
174 if (br
->stp_enabled
!= BR_NO_STP
)
179 /* called under bridge lock */
180 void br_stp_change_bridge_id(struct net_bridge
*br
, const unsigned char *addr
)
182 /* should be aligned on 2 bytes for compare_ether_addr() */
183 unsigned short oldaddr_aligned
[ETH_ALEN
>> 1];
184 unsigned char *oldaddr
= (unsigned char *)oldaddr_aligned
;
185 struct net_bridge_port
*p
;
188 wasroot
= br_is_root_bridge(br
);
190 memcpy(oldaddr
, br
->bridge_id
.addr
, ETH_ALEN
);
191 memcpy(br
->bridge_id
.addr
, addr
, ETH_ALEN
);
192 memcpy(br
->dev
->dev_addr
, addr
, ETH_ALEN
);
194 list_for_each_entry(p
, &br
->port_list
, list
) {
195 if (!compare_ether_addr(p
->designated_bridge
.addr
, oldaddr
))
196 memcpy(p
->designated_bridge
.addr
, addr
, ETH_ALEN
);
198 if (!compare_ether_addr(p
->designated_root
.addr
, oldaddr
))
199 memcpy(p
->designated_root
.addr
, addr
, ETH_ALEN
);
203 br_configuration_update(br
);
204 br_port_state_selection(br
);
205 if (br_is_root_bridge(br
) && !wasroot
)
206 br_become_root_bridge(br
);
209 /* should be aligned on 2 bytes for compare_ether_addr() */
210 static const unsigned short br_mac_zero_aligned
[ETH_ALEN
>> 1];
212 /* called under bridge lock */
213 void br_stp_recalculate_bridge_id(struct net_bridge
*br
)
215 const unsigned char *br_mac_zero
=
216 (const unsigned char *)br_mac_zero_aligned
;
217 const unsigned char *addr
= br_mac_zero
;
218 struct net_bridge_port
*p
;
220 list_for_each_entry(p
, &br
->port_list
, list
) {
221 if (addr
== br_mac_zero
||
222 memcmp(p
->dev
->dev_addr
, addr
, ETH_ALEN
) < 0)
223 addr
= p
->dev
->dev_addr
;
227 if (compare_ether_addr(br
->bridge_id
.addr
, addr
))
228 br_stp_change_bridge_id(br
, addr
);
231 /* called under bridge lock */
232 void br_stp_set_bridge_priority(struct net_bridge
*br
, u16 newprio
)
234 struct net_bridge_port
*p
;
237 wasroot
= br_is_root_bridge(br
);
239 list_for_each_entry(p
, &br
->port_list
, list
) {
240 if (p
->state
!= BR_STATE_DISABLED
&&
241 br_is_designated_port(p
)) {
242 p
->designated_bridge
.prio
[0] = (newprio
>> 8) & 0xFF;
243 p
->designated_bridge
.prio
[1] = newprio
& 0xFF;
248 br
->bridge_id
.prio
[0] = (newprio
>> 8) & 0xFF;
249 br
->bridge_id
.prio
[1] = newprio
& 0xFF;
250 br_configuration_update(br
);
251 br_port_state_selection(br
);
252 if (br_is_root_bridge(br
) && !wasroot
)
253 br_become_root_bridge(br
);
256 /* called under bridge lock */
257 void br_stp_set_port_priority(struct net_bridge_port
*p
, u8 newprio
)
259 port_id new_port_id
= br_make_port_id(newprio
, p
->port_no
);
261 if (br_is_designated_port(p
))
262 p
->designated_port
= new_port_id
;
264 p
->port_id
= new_port_id
;
265 p
->priority
= newprio
;
266 if (!memcmp(&p
->br
->bridge_id
, &p
->designated_bridge
, 8) &&
267 p
->port_id
< p
->designated_port
) {
268 br_become_designated_port(p
);
269 br_port_state_selection(p
->br
);
273 /* called under bridge lock */
274 void br_stp_set_path_cost(struct net_bridge_port
*p
, u32 path_cost
)
276 p
->path_cost
= path_cost
;
277 br_configuration_update(p
->br
);
278 br_port_state_selection(p
->br
);
281 ssize_t
br_show_bridge_id(char *buf
, const struct bridge_id
*id
)
283 return sprintf(buf
, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
284 id
->prio
[0], id
->prio
[1],
285 id
->addr
[0], id
->addr
[1], id
->addr
[2],
286 id
->addr
[3], id
->addr
[4], id
->addr
[5]);