2 * Spanning tree protocol; interface code
3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * 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.
14 #include <linux/kernel.h>
15 #include <linux/etherdevice.h>
16 #include <linux/rtnetlink.h>
18 #include "br_private.h"
19 #include "br_private_stp.h"
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.
26 static inline port_id
br_make_port_id(__u8 priority
, __u16 port_no
)
28 return ((u16
)priority
<< BR_PORT_BITS
)
29 | (port_no
& ((1<<BR_PORT_BITS
)-1));
32 /* called under bridge lock */
33 void br_init_port(struct net_bridge_port
*p
)
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;
42 /* called under bridge lock */
43 void br_stp_enable_bridge(struct net_bridge
*br
)
45 struct net_bridge_port
*p
;
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);
51 br_config_bpdu_generation(br
);
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
);
58 spin_unlock_bh(&br
->lock
);
62 void br_stp_disable_bridge(struct net_bridge
*br
)
64 struct net_bridge_port
*p
;
66 spin_lock_bh(&br
->lock
);
67 list_for_each_entry(p
, &br
->port_list
, list
) {
68 if (p
->state
!= BR_STATE_DISABLED
)
69 br_stp_disable_port(p
);
73 br
->topology_change
= 0;
74 br
->topology_change_detected
= 0;
75 spin_unlock_bh(&br
->lock
);
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
);
83 /* called under bridge lock */
84 void br_stp_enable_port(struct net_bridge_port
*p
)
87 br_port_state_selection(p
->br
);
90 /* called under bridge lock */
91 void br_stp_disable_port(struct net_bridge_port
*p
)
93 struct net_bridge
*br
;
97 printk(KERN_INFO
"%s: port %i(%s) entering %s state\n",
98 br
->dev
->name
, p
->port_no
, p
->dev
->name
, "disabled");
100 wasroot
= br_is_root_bridge(br
);
101 br_become_designated_port(p
);
102 p
->state
= BR_STATE_DISABLED
;
103 p
->topology_change_ack
= 0;
104 p
->config_pending
= 0;
106 del_timer(&p
->message_age_timer
);
107 del_timer(&p
->forward_delay_timer
);
108 del_timer(&p
->hold_timer
);
110 br_fdb_delete_by_port(br
, p
, 0);
111 br_multicast_disable_port(p
);
113 br_configuration_update(br
);
115 br_port_state_selection(br
);
117 if (br_is_root_bridge(br
) && !wasroot
)
118 br_become_root_bridge(br
);
121 static void br_stp_start(struct net_bridge
*br
)
124 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "start", NULL
};
125 char *envp
[] = { NULL
};
127 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
129 br
->stp_enabled
= BR_USER_STP
;
130 printk(KERN_INFO
"%s: userspace STP started\n", br
->dev
->name
);
132 br
->stp_enabled
= BR_KERNEL_STP
;
133 printk(KERN_INFO
"%s: starting userspace STP failed, "
134 "starting kernel STP\n", br
->dev
->name
);
136 /* To start timers on any ports left in blocking */
137 spin_lock_bh(&br
->lock
);
138 br_port_state_selection(br
);
139 spin_unlock_bh(&br
->lock
);
143 static void br_stp_stop(struct net_bridge
*br
)
146 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "stop", NULL
};
147 char *envp
[] = { NULL
};
149 if (br
->stp_enabled
== BR_USER_STP
) {
150 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, 1);
151 printk(KERN_INFO
"%s: userspace STP stopped, return code %d\n",
155 /* To start timers on any ports left in blocking */
156 spin_lock_bh(&br
->lock
);
157 br_port_state_selection(br
);
158 spin_unlock_bh(&br
->lock
);
161 br
->stp_enabled
= BR_NO_STP
;
164 void br_stp_set_enabled(struct net_bridge
*br
, unsigned long val
)
169 if (br
->stp_enabled
== BR_NO_STP
)
172 if (br
->stp_enabled
!= BR_NO_STP
)
177 /* called under bridge lock */
178 void br_stp_change_bridge_id(struct net_bridge
*br
, const unsigned char *addr
)
180 /* should be aligned on 2 bytes for compare_ether_addr() */
181 unsigned short oldaddr_aligned
[ETH_ALEN
>> 1];
182 unsigned char *oldaddr
= (unsigned char *)oldaddr_aligned
;
183 struct net_bridge_port
*p
;
186 wasroot
= br_is_root_bridge(br
);
188 memcpy(oldaddr
, br
->bridge_id
.addr
, ETH_ALEN
);
189 memcpy(br
->bridge_id
.addr
, addr
, ETH_ALEN
);
190 memcpy(br
->dev
->dev_addr
, addr
, ETH_ALEN
);
192 list_for_each_entry(p
, &br
->port_list
, list
) {
193 if (!compare_ether_addr(p
->designated_bridge
.addr
, oldaddr
))
194 memcpy(p
->designated_bridge
.addr
, addr
, ETH_ALEN
);
196 if (!compare_ether_addr(p
->designated_root
.addr
, oldaddr
))
197 memcpy(p
->designated_root
.addr
, addr
, ETH_ALEN
);
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
);
207 /* should be aligned on 2 bytes for compare_ether_addr() */
208 static const unsigned short br_mac_zero_aligned
[ETH_ALEN
>> 1];
210 /* called under bridge lock */
211 void br_stp_recalculate_bridge_id(struct net_bridge
*br
)
213 const unsigned char *br_mac_zero
=
214 (const unsigned char *)br_mac_zero_aligned
;
215 const unsigned char *addr
= br_mac_zero
;
216 struct net_bridge_port
*p
;
218 /* user has chosen a value so keep it */
219 if (br
->flags
& BR_SET_MAC_ADDR
)
222 list_for_each_entry(p
, &br
->port_list
, list
) {
223 if (addr
== br_mac_zero
||
224 memcmp(p
->dev
->dev_addr
, addr
, ETH_ALEN
) < 0)
225 addr
= p
->dev
->dev_addr
;
229 if (compare_ether_addr(br
->bridge_id
.addr
, addr
))
230 br_stp_change_bridge_id(br
, addr
);
233 /* called under bridge lock */
234 void br_stp_set_bridge_priority(struct net_bridge
*br
, u16 newprio
)
236 struct net_bridge_port
*p
;
239 wasroot
= br_is_root_bridge(br
);
241 list_for_each_entry(p
, &br
->port_list
, list
) {
242 if (p
->state
!= BR_STATE_DISABLED
&&
243 br_is_designated_port(p
)) {
244 p
->designated_bridge
.prio
[0] = (newprio
>> 8) & 0xFF;
245 p
->designated_bridge
.prio
[1] = newprio
& 0xFF;
250 br
->bridge_id
.prio
[0] = (newprio
>> 8) & 0xFF;
251 br
->bridge_id
.prio
[1] = newprio
& 0xFF;
252 br_configuration_update(br
);
253 br_port_state_selection(br
);
254 if (br_is_root_bridge(br
) && !wasroot
)
255 br_become_root_bridge(br
);
258 /* called under bridge lock */
259 void br_stp_set_port_priority(struct net_bridge_port
*p
, u8 newprio
)
261 port_id new_port_id
= br_make_port_id(newprio
, p
->port_no
);
263 if (br_is_designated_port(p
))
264 p
->designated_port
= new_port_id
;
266 p
->port_id
= new_port_id
;
267 p
->priority
= newprio
;
268 if (!memcmp(&p
->br
->bridge_id
, &p
->designated_bridge
, 8) &&
269 p
->port_id
< p
->designated_port
) {
270 br_become_designated_port(p
);
271 br_port_state_selection(p
->br
);
275 /* called under bridge lock */
276 void br_stp_set_path_cost(struct net_bridge_port
*p
, u32 path_cost
)
278 p
->path_cost
= path_cost
;
279 br_configuration_update(p
->br
);
280 br_port_state_selection(p
->br
);
283 ssize_t
br_show_bridge_id(char *buf
, const struct bridge_id
*id
)
285 return sprintf(buf
, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
286 id
->prio
[0], id
->prio
[1],
287 id
->addr
[0], id
->addr
[1], id
->addr
[2],
288 id
->addr
[3], id
->addr
[4], id
->addr
[5]);
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