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 = 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 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
148 spin_lock_bh(&br->lock);
150 if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
151 __br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
152 else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
153 __br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
156 br->stp_enabled = BR_USER_STP;
157 br_debug(br, "userspace STP started\n");
158 /* Stop hello and hold timers */
159 del_timer(&br->hello_timer);
160 list_for_each_entry(p, &br->port_list, list)
161 del_timer(&p->hold_timer);
163 br->stp_enabled = BR_KERNEL_STP;
164 br_debug(br, "using kernel STP\n");
166 /* To start timers on any ports left in blocking */
167 br_port_state_selection(br);
170 spin_unlock_bh(&br->lock);
173 static void br_stp_stop(struct net_bridge *br)
176 char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
177 char *envp[] = { NULL };
178 struct net_bridge_port *p;
180 if (br->stp_enabled == BR_USER_STP) {
181 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
182 br_info(br, "userspace STP stopped, return code %d\n", r);
184 /* To start timers on any ports left in blocking */
185 mod_timer(&br->hello_timer, jiffies + br->hello_time);
186 list_for_each_entry(p, &br->port_list, list)
187 mod_timer(&p->hold_timer,
188 round_jiffies(jiffies + BR_HOLD_TIME));
189 spin_lock_bh(&br->lock);
190 br_port_state_selection(br);
191 spin_unlock_bh(&br->lock);
194 br->stp_enabled = BR_NO_STP;
197 void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
202 if (br->stp_enabled == BR_NO_STP)
205 if (br->stp_enabled != BR_NO_STP)
210 /* called under bridge lock */
211 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
213 /* should be aligned on 2 bytes for ether_addr_equal() */
214 unsigned short oldaddr_aligned[ETH_ALEN >> 1];
215 unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
216 struct net_bridge_port *p;
219 wasroot = br_is_root_bridge(br);
221 br_fdb_change_mac_address(br, addr);
223 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
224 memcpy(br->bridge_id.addr, addr, ETH_ALEN);
225 memcpy(br->dev->dev_addr, addr, ETH_ALEN);
227 list_for_each_entry(p, &br->port_list, list) {
228 if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
229 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
231 if (ether_addr_equal(p->designated_root.addr, oldaddr))
232 memcpy(p->designated_root.addr, addr, ETH_ALEN);
235 br_configuration_update(br);
236 br_port_state_selection(br);
237 if (br_is_root_bridge(br) && !wasroot)
238 br_become_root_bridge(br);
241 /* should be aligned on 2 bytes for ether_addr_equal() */
242 static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
244 /* called under bridge lock */
245 bool br_stp_recalculate_bridge_id(struct net_bridge *br)
247 const unsigned char *br_mac_zero =
248 (const unsigned char *)br_mac_zero_aligned;
249 const unsigned char *addr = br_mac_zero;
250 struct net_bridge_port *p;
252 /* user has chosen a value so keep it */
253 if (br->dev->addr_assign_type == NET_ADDR_SET)
256 list_for_each_entry(p, &br->port_list, list) {
257 if (addr == br_mac_zero ||
258 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
259 addr = p->dev->dev_addr;
263 if (ether_addr_equal(br->bridge_id.addr, addr))
264 return false; /* no change */
266 br_stp_change_bridge_id(br, addr);
270 /* Acquires and releases bridge lock */
271 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
273 struct net_bridge_port *p;
276 spin_lock_bh(&br->lock);
277 wasroot = br_is_root_bridge(br);
279 list_for_each_entry(p, &br->port_list, list) {
280 if (p->state != BR_STATE_DISABLED &&
281 br_is_designated_port(p)) {
282 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
283 p->designated_bridge.prio[1] = newprio & 0xFF;
288 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
289 br->bridge_id.prio[1] = newprio & 0xFF;
290 br_configuration_update(br);
291 br_port_state_selection(br);
292 if (br_is_root_bridge(br) && !wasroot)
293 br_become_root_bridge(br);
294 spin_unlock_bh(&br->lock);
297 /* called under bridge lock */
298 int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
302 if (newprio > BR_MAX_PORT_PRIORITY)
305 new_port_id = br_make_port_id(newprio, p->port_no);
306 if (br_is_designated_port(p))
307 p->designated_port = new_port_id;
309 p->port_id = new_port_id;
310 p->priority = newprio;
311 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
312 p->port_id < p->designated_port) {
313 br_become_designated_port(p);
314 br_port_state_selection(p->br);
320 /* called under bridge lock */
321 int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
323 if (path_cost < BR_MIN_PATH_COST ||
324 path_cost > BR_MAX_PATH_COST)
327 p->flags |= BR_ADMIN_COST;
328 p->path_cost = path_cost;
329 br_configuration_update(p->br);
330 br_port_state_selection(p->br);
334 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
336 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
337 id->prio[0], id->prio[1],
338 id->addr[0], id->addr[1], id->addr[2],
339 id->addr[3], id->addr[4], id->addr[5]);