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>
20 #include "br_private.h"
21 #include "br_private_stp.h"
24 /* Port id is composed of priority and port number.
25 * NB: least significant bits of priority are dropped to
26 * make room for more ports.
28 static inline port_id
br_make_port_id(__u8 priority
, __u16 port_no
)
30 return ((u16
)priority
<< BR_PORT_BITS
)
31 | (port_no
& ((1<<BR_PORT_BITS
)-1));
34 /* called under bridge lock */
35 void br_init_port(struct net_bridge_port
*p
)
37 p
->port_id
= br_make_port_id(p
->priority
, p
->port_no
);
38 br_become_designated_port(p
);
39 p
->state
= BR_STATE_BLOCKING
;
40 p
->topology_change_ack
= 0;
41 p
->config_pending
= 0;
44 /* called under bridge lock */
45 void br_stp_enable_bridge(struct net_bridge
*br
)
47 struct net_bridge_port
*p
;
49 spin_lock_bh(&br
->lock
);
50 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
51 mod_timer(&br
->gc_timer
, jiffies
+ HZ
/10);
53 br_config_bpdu_generation(br
);
55 list_for_each_entry(p
, &br
->port_list
, list
) {
56 if ((p
->dev
->flags
& IFF_UP
) && netif_carrier_ok(p
->dev
))
57 br_stp_enable_port(p
);
60 spin_unlock_bh(&br
->lock
);
64 void br_stp_disable_bridge(struct net_bridge
*br
)
66 struct net_bridge_port
*p
;
68 spin_lock_bh(&br
->lock
);
69 list_for_each_entry(p
, &br
->port_list
, list
) {
70 if (p
->state
!= BR_STATE_DISABLED
)
71 br_stp_disable_port(p
);
75 br
->topology_change
= 0;
76 br
->topology_change_detected
= 0;
77 spin_unlock_bh(&br
->lock
);
79 del_timer_sync(&br
->hello_timer
);
80 del_timer_sync(&br
->topology_change_timer
);
81 del_timer_sync(&br
->tcn_timer
);
82 del_timer_sync(&br
->gc_timer
);
85 /* called under bridge lock */
86 void br_stp_enable_port(struct net_bridge_port
*p
)
89 br_port_state_selection(p
->br
);
92 /* called under bridge lock */
93 void br_stp_disable_port(struct net_bridge_port
*p
)
95 struct net_bridge
*br
;
99 printk(KERN_INFO
"%s: port %i(%s) entering %s state\n",
100 br
->dev
->name
, p
->port_no
, p
->dev
->name
, "disabled");
102 wasroot
= br_is_root_bridge(br
);
103 br_become_designated_port(p
);
104 p
->state
= BR_STATE_DISABLED
;
105 p
->topology_change_ack
= 0;
106 p
->config_pending
= 0;
108 del_timer(&p
->message_age_timer
);
109 del_timer(&p
->forward_delay_timer
);
110 del_timer(&p
->hold_timer
);
112 br_configuration_update(br
);
114 br_port_state_selection(br
);
116 if (br_is_root_bridge(br
) && !wasroot
)
117 br_become_root_bridge(br
);
120 /* called under bridge lock */
121 void br_stp_change_bridge_id(struct net_bridge
*br
, const unsigned char *addr
)
123 unsigned char oldaddr
[6];
124 struct net_bridge_port
*p
;
127 wasroot
= br_is_root_bridge(br
);
129 memcpy(oldaddr
, br
->bridge_id
.addr
, ETH_ALEN
);
130 memcpy(br
->bridge_id
.addr
, addr
, ETH_ALEN
);
131 memcpy(br
->dev
->dev_addr
, addr
, ETH_ALEN
);
133 list_for_each_entry(p
, &br
->port_list
, list
) {
134 if (!compare_ether_addr(p
->designated_bridge
.addr
, oldaddr
))
135 memcpy(p
->designated_bridge
.addr
, addr
, ETH_ALEN
);
137 if (!compare_ether_addr(p
->designated_root
.addr
, oldaddr
))
138 memcpy(p
->designated_root
.addr
, addr
, ETH_ALEN
);
142 br_configuration_update(br
);
143 br_port_state_selection(br
);
144 if (br_is_root_bridge(br
) && !wasroot
)
145 br_become_root_bridge(br
);
148 static const unsigned char br_mac_zero
[6];
150 /* called under bridge lock */
151 void br_stp_recalculate_bridge_id(struct net_bridge
*br
)
153 const unsigned char *addr
= br_mac_zero
;
154 struct net_bridge_port
*p
;
156 list_for_each_entry(p
, &br
->port_list
, list
) {
157 if (addr
== br_mac_zero
||
158 memcmp(p
->dev
->dev_addr
, addr
, ETH_ALEN
) < 0)
159 addr
= p
->dev
->dev_addr
;
163 if (compare_ether_addr(br
->bridge_id
.addr
, addr
))
164 br_stp_change_bridge_id(br
, addr
);
167 /* called under bridge lock */
168 void br_stp_set_bridge_priority(struct net_bridge
*br
, u16 newprio
)
170 struct net_bridge_port
*p
;
173 wasroot
= br_is_root_bridge(br
);
175 list_for_each_entry(p
, &br
->port_list
, list
) {
176 if (p
->state
!= BR_STATE_DISABLED
&&
177 br_is_designated_port(p
)) {
178 p
->designated_bridge
.prio
[0] = (newprio
>> 8) & 0xFF;
179 p
->designated_bridge
.prio
[1] = newprio
& 0xFF;
184 br
->bridge_id
.prio
[0] = (newprio
>> 8) & 0xFF;
185 br
->bridge_id
.prio
[1] = newprio
& 0xFF;
186 br_configuration_update(br
);
187 br_port_state_selection(br
);
188 if (br_is_root_bridge(br
) && !wasroot
)
189 br_become_root_bridge(br
);
192 /* called under bridge lock */
193 void br_stp_set_port_priority(struct net_bridge_port
*p
, u8 newprio
)
195 port_id new_port_id
= br_make_port_id(newprio
, p
->port_no
);
197 if (br_is_designated_port(p
))
198 p
->designated_port
= new_port_id
;
200 p
->port_id
= new_port_id
;
201 p
->priority
= newprio
;
202 if (!memcmp(&p
->br
->bridge_id
, &p
->designated_bridge
, 8) &&
203 p
->port_id
< p
->designated_port
) {
204 br_become_designated_port(p
);
205 br_port_state_selection(p
->br
);
209 /* called under bridge lock */
210 void br_stp_set_path_cost(struct net_bridge_port
*p
, u32 path_cost
)
212 p
->path_cost
= path_cost
;
213 br_configuration_update(p
->br
);
214 br_port_state_selection(p
->br
);
217 ssize_t
br_show_bridge_id(char *buf
, const struct bridge_id
*id
)
219 return sprintf(buf
, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
220 id
->prio
[0], id
->prio
[1],
221 id
->addr
[0], id
->addr
[1], id
->addr
[2],
222 id
->addr
[3], id
->addr
[4], id
->addr
[5]);