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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - net/bridge/br_stp_if.c
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
)
41 p
->port_id
= br_make_port_id(p
->priority
, p
->port_no
);
42 br_become_designated_port(p
);
43 br_set_state(p
, BR_STATE_BLOCKING
);
44 p
->topology_change_ack
= 0;
45 p
->config_pending
= 0;
47 err
= __set_ageing_time(p
->dev
, p
->br
->ageing_time
);
49 netdev_err(p
->dev
, "failed to offload ageing time\n");
53 void br_stp_enable_bridge(struct net_bridge
*br
)
55 struct net_bridge_port
*p
;
57 spin_lock_bh(&br
->lock
);
58 if (br
->stp_enabled
== BR_KERNEL_STP
)
59 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
60 mod_delayed_work(system_long_wq
, &br
->gc_work
, HZ
/ 10);
62 br_config_bpdu_generation(br
);
64 list_for_each_entry(p
, &br
->port_list
, list
) {
65 if (netif_running(p
->dev
) && netif_oper_up(p
->dev
))
66 br_stp_enable_port(p
);
69 spin_unlock_bh(&br
->lock
);
73 void br_stp_disable_bridge(struct net_bridge
*br
)
75 struct net_bridge_port
*p
;
77 spin_lock_bh(&br
->lock
);
78 list_for_each_entry(p
, &br
->port_list
, list
) {
79 if (p
->state
!= BR_STATE_DISABLED
)
80 br_stp_disable_port(p
);
84 __br_set_topology_change(br
, 0);
85 br
->topology_change_detected
= 0;
86 spin_unlock_bh(&br
->lock
);
88 del_timer_sync(&br
->hello_timer
);
89 del_timer_sync(&br
->topology_change_timer
);
90 del_timer_sync(&br
->tcn_timer
);
91 cancel_delayed_work_sync(&br
->gc_work
);
94 /* called under bridge lock */
95 void br_stp_enable_port(struct net_bridge_port
*p
)
98 br_port_state_selection(p
->br
);
99 br_ifinfo_notify(RTM_NEWLINK
, p
);
102 /* called under bridge lock */
103 void br_stp_disable_port(struct net_bridge_port
*p
)
105 struct net_bridge
*br
= p
->br
;
108 wasroot
= br_is_root_bridge(br
);
109 br_become_designated_port(p
);
110 br_set_state(p
, BR_STATE_DISABLED
);
111 p
->topology_change_ack
= 0;
112 p
->config_pending
= 0;
114 br_ifinfo_notify(RTM_NEWLINK
, p
);
116 del_timer(&p
->message_age_timer
);
117 del_timer(&p
->forward_delay_timer
);
118 del_timer(&p
->hold_timer
);
120 br_fdb_delete_by_port(br
, p
, 0, 0);
121 br_multicast_disable_port(p
);
123 br_configuration_update(br
);
125 br_port_state_selection(br
);
127 if (br_is_root_bridge(br
) && !wasroot
)
128 br_become_root_bridge(br
);
131 static int br_stp_call_user(struct net_bridge
*br
, char *arg
)
133 char *argv
[] = { BR_STP_PROG
, br
->dev
->name
, arg
, NULL
};
134 char *envp
[] = { NULL
};
137 /* call userspace STP and report program errors */
138 rc
= call_usermodehelper(BR_STP_PROG
, argv
, envp
, UMH_WAIT_PROC
);
141 br_debug(br
, BR_STP_PROG
" received signal %d\n",
144 br_debug(br
, BR_STP_PROG
" exited with code %d\n",
151 static void br_stp_start(struct net_bridge
*br
)
153 struct net_bridge_port
*p
;
156 if (net_eq(dev_net(br
->dev
), &init_net
))
157 err
= br_stp_call_user(br
, "start");
159 if (err
&& err
!= -ENOENT
)
160 br_err(br
, "failed to start userspace STP (%d)\n", err
);
162 spin_lock_bh(&br
->lock
);
164 if (br
->bridge_forward_delay
< BR_MIN_FORWARD_DELAY
)
165 __br_set_forward_delay(br
, BR_MIN_FORWARD_DELAY
);
166 else if (br
->bridge_forward_delay
> BR_MAX_FORWARD_DELAY
)
167 __br_set_forward_delay(br
, BR_MAX_FORWARD_DELAY
);
170 br
->stp_enabled
= BR_USER_STP
;
171 br_debug(br
, "userspace STP started\n");
173 /* Stop hello and hold timers */
174 del_timer(&br
->hello_timer
);
175 list_for_each_entry(p
, &br
->port_list
, list
)
176 del_timer(&p
->hold_timer
);
178 br
->stp_enabled
= BR_KERNEL_STP
;
179 br_debug(br
, "using kernel STP\n");
181 /* To start timers on any ports left in blocking */
182 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
183 br_port_state_selection(br
);
186 spin_unlock_bh(&br
->lock
);
189 static void br_stp_stop(struct net_bridge
*br
)
191 struct net_bridge_port
*p
;
194 if (br
->stp_enabled
== BR_USER_STP
) {
195 err
= br_stp_call_user(br
, "stop");
197 br_err(br
, "failed to stop userspace STP (%d)\n", err
);
199 /* To start timers on any ports left in blocking */
200 mod_timer(&br
->hello_timer
, jiffies
+ br
->hello_time
);
201 list_for_each_entry(p
, &br
->port_list
, list
)
202 mod_timer(&p
->hold_timer
,
203 round_jiffies(jiffies
+ BR_HOLD_TIME
));
204 spin_lock_bh(&br
->lock
);
205 br_port_state_selection(br
);
206 spin_unlock_bh(&br
->lock
);
209 br
->stp_enabled
= BR_NO_STP
;
212 void br_stp_set_enabled(struct net_bridge
*br
, unsigned long val
)
217 if (br
->stp_enabled
== BR_NO_STP
)
220 if (br
->stp_enabled
!= BR_NO_STP
)
225 /* called under bridge lock */
226 void br_stp_change_bridge_id(struct net_bridge
*br
, const unsigned char *addr
)
228 /* should be aligned on 2 bytes for ether_addr_equal() */
229 unsigned short oldaddr_aligned
[ETH_ALEN
>> 1];
230 unsigned char *oldaddr
= (unsigned char *)oldaddr_aligned
;
231 struct net_bridge_port
*p
;
234 wasroot
= br_is_root_bridge(br
);
236 br_fdb_change_mac_address(br
, addr
);
238 memcpy(oldaddr
, br
->bridge_id
.addr
, ETH_ALEN
);
239 memcpy(br
->bridge_id
.addr
, addr
, ETH_ALEN
);
240 memcpy(br
->dev
->dev_addr
, addr
, ETH_ALEN
);
242 list_for_each_entry(p
, &br
->port_list
, list
) {
243 if (ether_addr_equal(p
->designated_bridge
.addr
, oldaddr
))
244 memcpy(p
->designated_bridge
.addr
, addr
, ETH_ALEN
);
246 if (ether_addr_equal(p
->designated_root
.addr
, oldaddr
))
247 memcpy(p
->designated_root
.addr
, addr
, ETH_ALEN
);
250 br_configuration_update(br
);
251 br_port_state_selection(br
);
252 if (br_is_root_bridge(br
) && !wasroot
)
253 br_become_root_bridge(br
);
256 /* should be aligned on 2 bytes for ether_addr_equal() */
257 static const unsigned short br_mac_zero_aligned
[ETH_ALEN
>> 1];
259 /* called under bridge lock */
260 bool br_stp_recalculate_bridge_id(struct net_bridge
*br
)
262 const unsigned char *br_mac_zero
=
263 (const unsigned char *)br_mac_zero_aligned
;
264 const unsigned char *addr
= br_mac_zero
;
265 struct net_bridge_port
*p
;
267 /* user has chosen a value so keep it */
268 if (br
->dev
->addr_assign_type
== NET_ADDR_SET
)
271 list_for_each_entry(p
, &br
->port_list
, list
) {
272 if (addr
== br_mac_zero
||
273 memcmp(p
->dev
->dev_addr
, addr
, ETH_ALEN
) < 0)
274 addr
= p
->dev
->dev_addr
;
278 if (ether_addr_equal(br
->bridge_id
.addr
, addr
))
279 return false; /* no change */
281 br_stp_change_bridge_id(br
, addr
);
285 /* Acquires and releases bridge lock */
286 void br_stp_set_bridge_priority(struct net_bridge
*br
, u16 newprio
)
288 struct net_bridge_port
*p
;
291 spin_lock_bh(&br
->lock
);
292 wasroot
= br_is_root_bridge(br
);
294 list_for_each_entry(p
, &br
->port_list
, list
) {
295 if (p
->state
!= BR_STATE_DISABLED
&&
296 br_is_designated_port(p
)) {
297 p
->designated_bridge
.prio
[0] = (newprio
>> 8) & 0xFF;
298 p
->designated_bridge
.prio
[1] = newprio
& 0xFF;
303 br
->bridge_id
.prio
[0] = (newprio
>> 8) & 0xFF;
304 br
->bridge_id
.prio
[1] = newprio
& 0xFF;
305 br_configuration_update(br
);
306 br_port_state_selection(br
);
307 if (br_is_root_bridge(br
) && !wasroot
)
308 br_become_root_bridge(br
);
309 spin_unlock_bh(&br
->lock
);
312 /* called under bridge lock */
313 int br_stp_set_port_priority(struct net_bridge_port
*p
, unsigned long newprio
)
317 if (newprio
> BR_MAX_PORT_PRIORITY
)
320 new_port_id
= br_make_port_id(newprio
, p
->port_no
);
321 if (br_is_designated_port(p
))
322 p
->designated_port
= new_port_id
;
324 p
->port_id
= new_port_id
;
325 p
->priority
= newprio
;
326 if (!memcmp(&p
->br
->bridge_id
, &p
->designated_bridge
, 8) &&
327 p
->port_id
< p
->designated_port
) {
328 br_become_designated_port(p
);
329 br_port_state_selection(p
->br
);
335 /* called under bridge lock */
336 int br_stp_set_path_cost(struct net_bridge_port
*p
, unsigned long path_cost
)
338 if (path_cost
< BR_MIN_PATH_COST
||
339 path_cost
> BR_MAX_PATH_COST
)
342 p
->flags
|= BR_ADMIN_COST
;
343 p
->path_cost
= path_cost
;
344 br_configuration_update(p
->br
);
345 br_port_state_selection(p
->br
);
349 ssize_t
br_show_bridge_id(char *buf
, const struct bridge_id
*id
)
351 return sprintf(buf
, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
352 id
->prio
[0], id
->prio
[1],
353 id
->addr
[0], id
->addr
[1], id
->addr
[2],
354 id
->addr
[3], id
->addr
[4], id
->addr
[5]);