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/kmod.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
19 #include "br_private.h"
20 #include "br_private_stp.h"
23 /* Port id is composed of priority and port number.
24 * NB: some bits of priority are dropped to
25 * make room for more ports.
27 static inline port_id
br_make_port_id(__u8 priority
, __u16 port_no
)
29 return ((u16
)priority
<< BR_PORT_BITS
)
30 | (port_no
& ((1<<BR_PORT_BITS
)-1));
33 #define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
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 (netif_running(p
->dev
) && netif_oper_up(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
);
92 br_ifinfo_notify(RTM_NEWLINK
, p
);
95 /* called under bridge lock */
96 void br_stp_disable_port(struct net_bridge_port
*p
)
98 struct net_bridge
*br
= p
->br
;
101 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;
108 br_ifinfo_notify(RTM_NEWLINK
, p
);
110 del_timer(&p
->message_age_timer
);
111 del_timer(&p
->forward_delay_timer
);
112 del_timer(&p
->hold_timer
);
114 br_fdb_delete_by_port(br
, p
, 0);
115 br_multicast_disable_port(p
);
117 br_configuration_update(br
);
119 br_port_state_selection(br
);
121 if (br_is_root_bridge(br
) && !wasroot
)
122 br_become_root_bridge(br
);
125 static void br_stp_start(struct net_bridge
*br
)
128 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "start", NULL
};
129 char *envp
[] = { NULL
};
131 if (net_eq(dev_net(br
->dev
), &init_net
))
132 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
136 spin_lock_bh(&br
->lock
);
138 if (br
->bridge_forward_delay
< BR_MIN_FORWARD_DELAY
)
139 __br_set_forward_delay(br
, BR_MIN_FORWARD_DELAY
);
140 else if (br
->bridge_forward_delay
> BR_MAX_FORWARD_DELAY
)
141 __br_set_forward_delay(br
, BR_MAX_FORWARD_DELAY
);
144 br
->stp_enabled
= BR_USER_STP
;
145 br_debug(br
, "userspace STP started\n");
147 br
->stp_enabled
= BR_KERNEL_STP
;
148 br_debug(br
, "using kernel STP\n");
150 /* To start timers on any ports left in blocking */
151 br_port_state_selection(br
);
154 spin_unlock_bh(&br
->lock
);
157 static void br_stp_stop(struct net_bridge
*br
)
160 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "stop", NULL
};
161 char *envp
[] = { NULL
};
163 if (br
->stp_enabled
== BR_USER_STP
) {
164 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
165 br_info(br
, "userspace STP stopped, return code %d\n", r
);
167 /* To start timers on any ports left in blocking */
168 spin_lock_bh(&br
->lock
);
169 br_port_state_selection(br
);
170 spin_unlock_bh(&br
->lock
);
173 br
->stp_enabled
= BR_NO_STP
;
176 void br_stp_set_enabled(struct net_bridge
*br
, unsigned long val
)
181 if (br
->stp_enabled
== BR_NO_STP
)
184 if (br
->stp_enabled
!= BR_NO_STP
)
189 /* called under bridge lock */
190 void br_stp_change_bridge_id(struct net_bridge
*br
, const unsigned char *addr
)
192 /* should be aligned on 2 bytes for ether_addr_equal() */
193 unsigned short oldaddr_aligned
[ETH_ALEN
>> 1];
194 unsigned char *oldaddr
= (unsigned char *)oldaddr_aligned
;
195 struct net_bridge_port
*p
;
198 wasroot
= br_is_root_bridge(br
);
200 memcpy(oldaddr
, br
->bridge_id
.addr
, ETH_ALEN
);
201 memcpy(br
->bridge_id
.addr
, addr
, ETH_ALEN
);
202 memcpy(br
->dev
->dev_addr
, addr
, ETH_ALEN
);
204 list_for_each_entry(p
, &br
->port_list
, list
) {
205 if (ether_addr_equal(p
->designated_bridge
.addr
, oldaddr
))
206 memcpy(p
->designated_bridge
.addr
, addr
, ETH_ALEN
);
208 if (ether_addr_equal(p
->designated_root
.addr
, oldaddr
))
209 memcpy(p
->designated_root
.addr
, addr
, ETH_ALEN
);
212 br_configuration_update(br
);
213 br_port_state_selection(br
);
214 if (br_is_root_bridge(br
) && !wasroot
)
215 br_become_root_bridge(br
);
218 /* should be aligned on 2 bytes for ether_addr_equal() */
219 static const unsigned short br_mac_zero_aligned
[ETH_ALEN
>> 1];
221 /* called under bridge lock */
222 bool br_stp_recalculate_bridge_id(struct net_bridge
*br
)
224 const unsigned char *br_mac_zero
=
225 (const unsigned char *)br_mac_zero_aligned
;
226 const unsigned char *addr
= br_mac_zero
;
227 struct net_bridge_port
*p
;
229 /* user has chosen a value so keep it */
230 if (br
->dev
->addr_assign_type
== NET_ADDR_SET
)
233 list_for_each_entry(p
, &br
->port_list
, list
) {
234 if (addr
== br_mac_zero
||
235 memcmp(p
->dev
->dev_addr
, addr
, ETH_ALEN
) < 0)
236 addr
= p
->dev
->dev_addr
;
240 if (ether_addr_equal(br
->bridge_id
.addr
, addr
))
241 return false; /* no change */
243 br_stp_change_bridge_id(br
, addr
);
247 /* Acquires and releases bridge lock */
248 void br_stp_set_bridge_priority(struct net_bridge
*br
, u16 newprio
)
250 struct net_bridge_port
*p
;
253 spin_lock_bh(&br
->lock
);
254 wasroot
= br_is_root_bridge(br
);
256 list_for_each_entry(p
, &br
->port_list
, list
) {
257 if (p
->state
!= BR_STATE_DISABLED
&&
258 br_is_designated_port(p
)) {
259 p
->designated_bridge
.prio
[0] = (newprio
>> 8) & 0xFF;
260 p
->designated_bridge
.prio
[1] = newprio
& 0xFF;
265 br
->bridge_id
.prio
[0] = (newprio
>> 8) & 0xFF;
266 br
->bridge_id
.prio
[1] = newprio
& 0xFF;
267 br_configuration_update(br
);
268 br_port_state_selection(br
);
269 if (br_is_root_bridge(br
) && !wasroot
)
270 br_become_root_bridge(br
);
271 spin_unlock_bh(&br
->lock
);
274 /* called under bridge lock */
275 int br_stp_set_port_priority(struct net_bridge_port
*p
, unsigned long newprio
)
279 if (newprio
> BR_MAX_PORT_PRIORITY
)
282 new_port_id
= br_make_port_id(newprio
, p
->port_no
);
283 if (br_is_designated_port(p
))
284 p
->designated_port
= new_port_id
;
286 p
->port_id
= new_port_id
;
287 p
->priority
= newprio
;
288 if (!memcmp(&p
->br
->bridge_id
, &p
->designated_bridge
, 8) &&
289 p
->port_id
< p
->designated_port
) {
290 br_become_designated_port(p
);
291 br_port_state_selection(p
->br
);
297 /* called under bridge lock */
298 int br_stp_set_path_cost(struct net_bridge_port
*p
, unsigned long path_cost
)
300 if (path_cost
< BR_MIN_PATH_COST
||
301 path_cost
> BR_MAX_PATH_COST
)
304 p
->flags
|= BR_ADMIN_COST
;
305 p
->path_cost
= path_cost
;
306 br_configuration_update(p
->br
);
307 br_port_state_selection(p
->br
);
311 ssize_t
br_show_bridge_id(char *buf
, const struct bridge_id
*id
)
313 return sprintf(buf
, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
314 id
->prio
[0], id
->prio
[1],
315 id
->addr
[0], id
->addr
[1], id
->addr
[2],
316 id
->addr
[3], id
->addr
[4], id
->addr
[5]);