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>
18 #include <net/switchdev.h>
20 #include "br_private.h"
21 #include "br_private_stp.h"
24 /* Port id is composed of priority and port number.
25 * NB: some 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 #define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
36 /* called under bridge lock */
37 void br_init_port(struct net_bridge_port
*p
)
39 struct switchdev_attr attr
= {
40 .id
= SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME
,
41 .flags
= SWITCHDEV_F_SKIP_EOPNOTSUPP
| SWITCHDEV_F_DEFER
,
42 .u
.ageing_time
= p
->br
->ageing_time
,
46 p
->port_id
= br_make_port_id(p
->priority
, p
->port_no
);
47 br_become_designated_port(p
);
48 br_set_state(p
, BR_STATE_BLOCKING
);
49 p
->topology_change_ack
= 0;
50 p
->config_pending
= 0;
52 err
= switchdev_port_attr_set(p
->dev
, &attr
);
53 if (err
&& err
!= -EOPNOTSUPP
)
54 netdev_err(p
->dev
, "failed to set HW ageing time\n");
57 /* called under bridge lock */
58 void br_stp_enable_bridge(struct net_bridge
*br
)
60 struct net_bridge_port
*p
;
62 spin_lock_bh(&br
->lock
);
63 if (br
->stp_enabled
== BR_KERNEL_STP
)
64 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
65 mod_timer(&br
->gc_timer
, jiffies
+ HZ
/10);
67 br_config_bpdu_generation(br
);
69 list_for_each_entry(p
, &br
->port_list
, list
) {
70 if (netif_running(p
->dev
) && netif_oper_up(p
->dev
))
71 br_stp_enable_port(p
);
74 spin_unlock_bh(&br
->lock
);
78 void br_stp_disable_bridge(struct net_bridge
*br
)
80 struct net_bridge_port
*p
;
82 spin_lock_bh(&br
->lock
);
83 list_for_each_entry(p
, &br
->port_list
, list
) {
84 if (p
->state
!= BR_STATE_DISABLED
)
85 br_stp_disable_port(p
);
89 br
->topology_change
= 0;
90 br
->topology_change_detected
= 0;
91 spin_unlock_bh(&br
->lock
);
93 del_timer_sync(&br
->hello_timer
);
94 del_timer_sync(&br
->topology_change_timer
);
95 del_timer_sync(&br
->tcn_timer
);
96 del_timer_sync(&br
->gc_timer
);
99 /* called under bridge lock */
100 void br_stp_enable_port(struct net_bridge_port
*p
)
103 br_port_state_selection(p
->br
);
105 br_ifinfo_notify(RTM_NEWLINK
, p
);
108 /* called under bridge lock */
109 void br_stp_disable_port(struct net_bridge_port
*p
)
111 struct net_bridge
*br
= p
->br
;
114 wasroot
= br_is_root_bridge(br
);
115 br_become_designated_port(p
);
116 br_set_state(p
, BR_STATE_DISABLED
);
117 p
->topology_change_ack
= 0;
118 p
->config_pending
= 0;
121 br_ifinfo_notify(RTM_NEWLINK
, p
);
123 del_timer(&p
->message_age_timer
);
124 del_timer(&p
->forward_delay_timer
);
125 del_timer(&p
->hold_timer
);
127 br_fdb_delete_by_port(br
, p
, 0, 0);
128 br_multicast_disable_port(p
);
130 br_configuration_update(br
);
132 br_port_state_selection(br
);
134 if (br_is_root_bridge(br
) && !wasroot
)
135 br_become_root_bridge(br
);
138 static void br_stp_start(struct net_bridge
*br
)
141 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "start", NULL
};
142 char *envp
[] = { NULL
};
143 struct net_bridge_port
*p
;
145 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
147 spin_lock_bh(&br
->lock
);
149 if (br
->bridge_forward_delay
< BR_MIN_FORWARD_DELAY
)
150 __br_set_forward_delay(br
, BR_MIN_FORWARD_DELAY
);
151 else if (br
->bridge_forward_delay
> BR_MAX_FORWARD_DELAY
)
152 __br_set_forward_delay(br
, BR_MAX_FORWARD_DELAY
);
155 br
->stp_enabled
= BR_USER_STP
;
156 br_debug(br
, "userspace STP started\n");
157 /* Stop hello and hold timers */
158 del_timer(&br
->hello_timer
);
159 list_for_each_entry(p
, &br
->port_list
, list
)
160 del_timer(&p
->hold_timer
);
162 br
->stp_enabled
= BR_KERNEL_STP
;
163 br_debug(br
, "using kernel STP\n");
165 /* To start timers on any ports left in blocking */
166 br_port_state_selection(br
);
169 spin_unlock_bh(&br
->lock
);
172 static void br_stp_stop(struct net_bridge
*br
)
175 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "stop", NULL
};
176 char *envp
[] = { NULL
};
177 struct net_bridge_port
*p
;
179 if (br
->stp_enabled
== BR_USER_STP
) {
180 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
181 br_info(br
, "userspace STP stopped, return code %d\n", r
);
183 /* To start timers on any ports left in blocking */
184 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
185 list_for_each_entry(p
, &br
->port_list
, list
)
186 mod_timer(&p
->hold_timer
,
187 round_jiffies(jiffies
+ BR_HOLD_TIME
));
188 spin_lock_bh(&br
->lock
);
189 br_port_state_selection(br
);
190 spin_unlock_bh(&br
->lock
);
193 br
->stp_enabled
= BR_NO_STP
;
196 void br_stp_set_enabled(struct net_bridge
*br
, unsigned long val
)
201 if (br
->stp_enabled
== BR_NO_STP
)
204 if (br
->stp_enabled
!= BR_NO_STP
)
209 /* called under bridge lock */
210 void br_stp_change_bridge_id(struct net_bridge
*br
, const unsigned char *addr
)
212 /* should be aligned on 2 bytes for ether_addr_equal() */
213 unsigned short oldaddr_aligned
[ETH_ALEN
>> 1];
214 unsigned char *oldaddr
= (unsigned char *)oldaddr_aligned
;
215 struct net_bridge_port
*p
;
218 wasroot
= br_is_root_bridge(br
);
220 br_fdb_change_mac_address(br
, addr
);
222 memcpy(oldaddr
, br
->bridge_id
.addr
, ETH_ALEN
);
223 memcpy(br
->bridge_id
.addr
, addr
, ETH_ALEN
);
224 memcpy(br
->dev
->dev_addr
, addr
, ETH_ALEN
);
226 list_for_each_entry(p
, &br
->port_list
, list
) {
227 if (ether_addr_equal(p
->designated_bridge
.addr
, oldaddr
))
228 memcpy(p
->designated_bridge
.addr
, addr
, ETH_ALEN
);
230 if (ether_addr_equal(p
->designated_root
.addr
, oldaddr
))
231 memcpy(p
->designated_root
.addr
, addr
, ETH_ALEN
);
234 br_configuration_update(br
);
235 br_port_state_selection(br
);
236 if (br_is_root_bridge(br
) && !wasroot
)
237 br_become_root_bridge(br
);
240 /* should be aligned on 2 bytes for ether_addr_equal() */
241 static const unsigned short br_mac_zero_aligned
[ETH_ALEN
>> 1];
243 /* called under bridge lock */
244 bool br_stp_recalculate_bridge_id(struct net_bridge
*br
)
246 const unsigned char *br_mac_zero
=
247 (const unsigned char *)br_mac_zero_aligned
;
248 const unsigned char *addr
= br_mac_zero
;
249 struct net_bridge_port
*p
;
251 /* user has chosen a value so keep it */
252 if (br
->dev
->addr_assign_type
== NET_ADDR_SET
)
255 list_for_each_entry(p
, &br
->port_list
, list
) {
256 if (addr
== br_mac_zero
||
257 memcmp(p
->dev
->dev_addr
, addr
, ETH_ALEN
) < 0)
258 addr
= p
->dev
->dev_addr
;
262 if (ether_addr_equal(br
->bridge_id
.addr
, addr
))
263 return false; /* no change */
265 br_stp_change_bridge_id(br
, addr
);
269 /* Acquires and releases bridge lock */
270 void br_stp_set_bridge_priority(struct net_bridge
*br
, u16 newprio
)
272 struct net_bridge_port
*p
;
275 spin_lock_bh(&br
->lock
);
276 wasroot
= br_is_root_bridge(br
);
278 list_for_each_entry(p
, &br
->port_list
, list
) {
279 if (p
->state
!= BR_STATE_DISABLED
&&
280 br_is_designated_port(p
)) {
281 p
->designated_bridge
.prio
[0] = (newprio
>> 8) & 0xFF;
282 p
->designated_bridge
.prio
[1] = newprio
& 0xFF;
287 br
->bridge_id
.prio
[0] = (newprio
>> 8) & 0xFF;
288 br
->bridge_id
.prio
[1] = newprio
& 0xFF;
289 br_configuration_update(br
);
290 br_port_state_selection(br
);
291 if (br_is_root_bridge(br
) && !wasroot
)
292 br_become_root_bridge(br
);
293 spin_unlock_bh(&br
->lock
);
296 /* called under bridge lock */
297 int br_stp_set_port_priority(struct net_bridge_port
*p
, unsigned long newprio
)
301 if (newprio
> BR_MAX_PORT_PRIORITY
)
304 new_port_id
= br_make_port_id(newprio
, p
->port_no
);
305 if (br_is_designated_port(p
))
306 p
->designated_port
= new_port_id
;
308 p
->port_id
= new_port_id
;
309 p
->priority
= newprio
;
310 if (!memcmp(&p
->br
->bridge_id
, &p
->designated_bridge
, 8) &&
311 p
->port_id
< p
->designated_port
) {
312 br_become_designated_port(p
);
313 br_port_state_selection(p
->br
);
319 /* called under bridge lock */
320 int br_stp_set_path_cost(struct net_bridge_port
*p
, unsigned long path_cost
)
322 if (path_cost
< BR_MIN_PATH_COST
||
323 path_cost
> BR_MAX_PATH_COST
)
326 p
->flags
|= BR_ADMIN_COST
;
327 p
->path_cost
= path_cost
;
328 br_configuration_update(p
->br
);
329 br_port_state_selection(p
->br
);
333 ssize_t
br_show_bridge_id(char *buf
, const struct bridge_id
*id
)
335 return sprintf(buf
, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
336 id
->prio
[0], id
->prio
[1],
337 id
->addr
[0], id
->addr
[1], id
->addr
[2],
338 id
->addr
[3], id
->addr
[4], id
->addr
[5]);