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
= {
41 .id
= SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME
,
42 .flags
= SWITCHDEV_F_SKIP_EOPNOTSUPP
| SWITCHDEV_F_DEFER
,
43 .u
.ageing_time
= jiffies_to_clock_t(p
->br
->ageing_time
),
47 p
->port_id
= br_make_port_id(p
->priority
, p
->port_no
);
48 br_become_designated_port(p
);
49 br_set_state(p
, BR_STATE_BLOCKING
);
50 p
->topology_change_ack
= 0;
51 p
->config_pending
= 0;
53 err
= switchdev_port_attr_set(p
->dev
, &attr
);
54 if (err
&& err
!= -EOPNOTSUPP
)
55 netdev_err(p
->dev
, "failed to set HW ageing time\n");
58 /* called under bridge lock */
59 void br_stp_enable_bridge(struct net_bridge
*br
)
61 struct net_bridge_port
*p
;
63 spin_lock_bh(&br
->lock
);
64 if (br
->stp_enabled
== BR_KERNEL_STP
)
65 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
66 mod_timer(&br
->gc_timer
, jiffies
+ HZ
/10);
68 br_config_bpdu_generation(br
);
70 list_for_each_entry(p
, &br
->port_list
, list
) {
71 if (netif_running(p
->dev
) && netif_oper_up(p
->dev
))
72 br_stp_enable_port(p
);
75 spin_unlock_bh(&br
->lock
);
79 void br_stp_disable_bridge(struct net_bridge
*br
)
81 struct net_bridge_port
*p
;
83 spin_lock_bh(&br
->lock
);
84 list_for_each_entry(p
, &br
->port_list
, list
) {
85 if (p
->state
!= BR_STATE_DISABLED
)
86 br_stp_disable_port(p
);
90 br
->topology_change
= 0;
91 br
->topology_change_detected
= 0;
92 spin_unlock_bh(&br
->lock
);
94 del_timer_sync(&br
->hello_timer
);
95 del_timer_sync(&br
->topology_change_timer
);
96 del_timer_sync(&br
->tcn_timer
);
97 del_timer_sync(&br
->gc_timer
);
100 /* called under bridge lock */
101 void br_stp_enable_port(struct net_bridge_port
*p
)
104 br_port_state_selection(p
->br
);
106 br_ifinfo_notify(RTM_NEWLINK
, p
);
109 /* called under bridge lock */
110 void br_stp_disable_port(struct net_bridge_port
*p
)
112 struct net_bridge
*br
= p
->br
;
115 wasroot
= br_is_root_bridge(br
);
116 br_become_designated_port(p
);
117 br_set_state(p
, BR_STATE_DISABLED
);
118 p
->topology_change_ack
= 0;
119 p
->config_pending
= 0;
122 br_ifinfo_notify(RTM_NEWLINK
, p
);
124 del_timer(&p
->message_age_timer
);
125 del_timer(&p
->forward_delay_timer
);
126 del_timer(&p
->hold_timer
);
128 br_fdb_delete_by_port(br
, p
, 0, 0);
129 br_multicast_disable_port(p
);
131 br_configuration_update(br
);
133 br_port_state_selection(br
);
135 if (br_is_root_bridge(br
) && !wasroot
)
136 br_become_root_bridge(br
);
139 static void br_stp_start(struct net_bridge
*br
)
142 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "start", NULL
};
143 char *envp
[] = { NULL
};
144 struct net_bridge_port
*p
;
146 if (net_eq(dev_net(br
->dev
), &init_net
))
147 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
151 spin_lock_bh(&br
->lock
);
153 if (br
->bridge_forward_delay
< BR_MIN_FORWARD_DELAY
)
154 __br_set_forward_delay(br
, BR_MIN_FORWARD_DELAY
);
155 else if (br
->bridge_forward_delay
> BR_MAX_FORWARD_DELAY
)
156 __br_set_forward_delay(br
, BR_MAX_FORWARD_DELAY
);
159 br
->stp_enabled
= BR_USER_STP
;
160 br_debug(br
, "userspace STP started\n");
161 /* Stop hello and hold timers */
162 del_timer(&br
->hello_timer
);
163 list_for_each_entry(p
, &br
->port_list
, list
)
164 del_timer(&p
->hold_timer
);
166 br
->stp_enabled
= BR_KERNEL_STP
;
167 br_debug(br
, "using kernel STP\n");
169 /* To start timers on any ports left in blocking */
170 br_port_state_selection(br
);
173 spin_unlock_bh(&br
->lock
);
176 static void br_stp_stop(struct net_bridge
*br
)
179 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, "stop", NULL
};
180 char *envp
[] = { NULL
};
181 struct net_bridge_port
*p
;
183 if (br
->stp_enabled
== BR_USER_STP
) {
184 r
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
185 br_info(br
, "userspace STP stopped, return code %d\n", r
);
187 /* To start timers on any ports left in blocking */
188 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
189 list_for_each_entry(p
, &br
->port_list
, list
)
190 mod_timer(&p
->hold_timer
,
191 round_jiffies(jiffies
+ BR_HOLD_TIME
));
192 spin_lock_bh(&br
->lock
);
193 br_port_state_selection(br
);
194 spin_unlock_bh(&br
->lock
);
197 br
->stp_enabled
= BR_NO_STP
;
200 void br_stp_set_enabled(struct net_bridge
*br
, unsigned long val
)
205 if (br
->stp_enabled
== BR_NO_STP
)
208 if (br
->stp_enabled
!= BR_NO_STP
)
213 /* called under bridge lock */
214 void br_stp_change_bridge_id(struct net_bridge
*br
, const unsigned char *addr
)
216 /* should be aligned on 2 bytes for ether_addr_equal() */
217 unsigned short oldaddr_aligned
[ETH_ALEN
>> 1];
218 unsigned char *oldaddr
= (unsigned char *)oldaddr_aligned
;
219 struct net_bridge_port
*p
;
222 wasroot
= br_is_root_bridge(br
);
224 br_fdb_change_mac_address(br
, addr
);
226 memcpy(oldaddr
, br
->bridge_id
.addr
, ETH_ALEN
);
227 memcpy(br
->bridge_id
.addr
, addr
, ETH_ALEN
);
228 memcpy(br
->dev
->dev_addr
, addr
, ETH_ALEN
);
230 list_for_each_entry(p
, &br
->port_list
, list
) {
231 if (ether_addr_equal(p
->designated_bridge
.addr
, oldaddr
))
232 memcpy(p
->designated_bridge
.addr
, addr
, ETH_ALEN
);
234 if (ether_addr_equal(p
->designated_root
.addr
, oldaddr
))
235 memcpy(p
->designated_root
.addr
, addr
, ETH_ALEN
);
238 br_configuration_update(br
);
239 br_port_state_selection(br
);
240 if (br_is_root_bridge(br
) && !wasroot
)
241 br_become_root_bridge(br
);
244 /* should be aligned on 2 bytes for ether_addr_equal() */
245 static const unsigned short br_mac_zero_aligned
[ETH_ALEN
>> 1];
247 /* called under bridge lock */
248 bool br_stp_recalculate_bridge_id(struct net_bridge
*br
)
250 const unsigned char *br_mac_zero
=
251 (const unsigned char *)br_mac_zero_aligned
;
252 const unsigned char *addr
= br_mac_zero
;
253 struct net_bridge_port
*p
;
255 /* user has chosen a value so keep it */
256 if (br
->dev
->addr_assign_type
== NET_ADDR_SET
)
259 list_for_each_entry(p
, &br
->port_list
, list
) {
260 if (addr
== br_mac_zero
||
261 memcmp(p
->dev
->dev_addr
, addr
, ETH_ALEN
) < 0)
262 addr
= p
->dev
->dev_addr
;
266 if (ether_addr_equal(br
->bridge_id
.addr
, addr
))
267 return false; /* no change */
269 br_stp_change_bridge_id(br
, addr
);
273 /* Acquires and releases bridge lock */
274 void br_stp_set_bridge_priority(struct net_bridge
*br
, u16 newprio
)
276 struct net_bridge_port
*p
;
279 spin_lock_bh(&br
->lock
);
280 wasroot
= br_is_root_bridge(br
);
282 list_for_each_entry(p
, &br
->port_list
, list
) {
283 if (p
->state
!= BR_STATE_DISABLED
&&
284 br_is_designated_port(p
)) {
285 p
->designated_bridge
.prio
[0] = (newprio
>> 8) & 0xFF;
286 p
->designated_bridge
.prio
[1] = newprio
& 0xFF;
291 br
->bridge_id
.prio
[0] = (newprio
>> 8) & 0xFF;
292 br
->bridge_id
.prio
[1] = newprio
& 0xFF;
293 br_configuration_update(br
);
294 br_port_state_selection(br
);
295 if (br_is_root_bridge(br
) && !wasroot
)
296 br_become_root_bridge(br
);
297 spin_unlock_bh(&br
->lock
);
300 /* called under bridge lock */
301 int br_stp_set_port_priority(struct net_bridge_port
*p
, unsigned long newprio
)
305 if (newprio
> BR_MAX_PORT_PRIORITY
)
308 new_port_id
= br_make_port_id(newprio
, p
->port_no
);
309 if (br_is_designated_port(p
))
310 p
->designated_port
= new_port_id
;
312 p
->port_id
= new_port_id
;
313 p
->priority
= newprio
;
314 if (!memcmp(&p
->br
->bridge_id
, &p
->designated_bridge
, 8) &&
315 p
->port_id
< p
->designated_port
) {
316 br_become_designated_port(p
);
317 br_port_state_selection(p
->br
);
323 /* called under bridge lock */
324 int br_stp_set_path_cost(struct net_bridge_port
*p
, unsigned long path_cost
)
326 if (path_cost
< BR_MIN_PATH_COST
||
327 path_cost
> BR_MAX_PATH_COST
)
330 p
->flags
|= BR_ADMIN_COST
;
331 p
->path_cost
= path_cost
;
332 br_configuration_update(p
->br
);
333 br_port_state_selection(p
->br
);
337 ssize_t
br_show_bridge_id(char *buf
, const struct bridge_id
*id
)
339 return sprintf(buf
, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
340 id
->prio
[0], id
->prio
[1],
341 id
->addr
[0], id
->addr
[1], id
->addr
[2],
342 id
->addr
[3], id
->addr
[4], id
->addr
[5]);