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]);