2 * Spanning tree protocol; interface code
3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * $Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 davem Exp $
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
16 #include <linux/kernel.h>
17 #include <linux/smp_lock.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
21 #include "br_private.h"
22 #include "br_private_stp.h"
25 /* Port id is composed of priority and port number.
26 * NB: least significant bits of priority are dropped to
27 * make room for more ports.
29 static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
31 return ((u16)priority << BR_PORT_BITS)
32 | (port_no & ((1<<BR_PORT_BITS)-1));
35 /* called under bridge lock */
36 void br_init_port(struct net_bridge_port *p)
38 p->port_id = br_make_port_id(p->priority, p->port_no);
39 br_become_designated_port(p);
40 p->state = BR_STATE_BLOCKING;
41 p->topology_change_ack = 0;
42 p->config_pending = 0;
45 /* called under bridge lock */
46 void br_stp_enable_bridge(struct net_bridge *br)
48 struct net_bridge_port *p;
50 spin_lock_bh(&br->lock);
51 mod_timer(&br->hello_timer, jiffies + br->hello_time);
52 mod_timer(&br->gc_timer, jiffies + HZ/10);
54 br_config_bpdu_generation(br);
56 list_for_each_entry(p, &br->port_list, list) {
57 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
58 br_stp_enable_port(p);
61 spin_unlock_bh(&br->lock);
65 void br_stp_disable_bridge(struct net_bridge *br)
67 struct net_bridge_port *p;
69 spin_lock_bh(&br->lock);
70 list_for_each_entry(p, &br->port_list, list) {
71 if (p->state != BR_STATE_DISABLED)
72 br_stp_disable_port(p);
76 br->topology_change = 0;
77 br->topology_change_detected = 0;
78 spin_unlock_bh(&br->lock);
80 del_timer_sync(&br->hello_timer);
81 del_timer_sync(&br->topology_change_timer);
82 del_timer_sync(&br->tcn_timer);
83 del_timer_sync(&br->gc_timer);
86 /* called under bridge lock */
87 void br_stp_enable_port(struct net_bridge_port *p)
90 br_ifinfo_notify(RTM_NEWLINK, p);
91 br_port_state_selection(p->br);
94 /* called under bridge lock */
95 void br_stp_disable_port(struct net_bridge_port *p)
97 struct net_bridge *br;
101 printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
102 br->dev->name, p->port_no, p->dev->name, "disabled");
104 br_ifinfo_notify(RTM_DELLINK, p);
106 wasroot = br_is_root_bridge(br);
107 br_become_designated_port(p);
108 p->state = BR_STATE_DISABLED;
109 p->topology_change_ack = 0;
110 p->config_pending = 0;
112 del_timer(&p->message_age_timer);
113 del_timer(&p->forward_delay_timer);
114 del_timer(&p->hold_timer);
116 br_fdb_delete_by_port(br, p, 0);
118 br_configuration_update(br);
120 br_port_state_selection(br);
122 if (br_is_root_bridge(br) && !wasroot)
123 br_become_root_bridge(br);
126 static void br_stp_start(struct net_bridge *br)
129 char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
130 char *envp[] = { NULL };
132 r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
134 br->stp_enabled = BR_USER_STP;
135 printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
137 br->stp_enabled = BR_KERNEL_STP;
138 printk(KERN_INFO "%s: starting userspace STP failed, "
139 "staring kernel STP\n", br->dev->name);
141 /* To start timers on any ports left in blocking */
142 spin_lock_bh(&br->lock);
143 br_port_state_selection(br);
144 spin_unlock_bh(&br->lock);
148 static void br_stp_stop(struct net_bridge *br)
151 char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
152 char *envp[] = { NULL };
154 if (br->stp_enabled == BR_USER_STP) {
155 r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
156 printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
160 /* To start timers on any ports left in blocking */
161 spin_lock_bh(&br->lock);
162 br_port_state_selection(br);
163 spin_unlock_bh(&br->lock);
166 br->stp_enabled = BR_NO_STP;
169 void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
174 if (br->stp_enabled == BR_NO_STP)
177 if (br->stp_enabled != BR_NO_STP)
182 /* called under bridge lock */
183 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
185 /* should be aligned on 2 bytes for compare_ether_addr() */
186 unsigned short oldaddr_aligned[ETH_ALEN >> 1];
187 unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
188 struct net_bridge_port *p;
191 wasroot = br_is_root_bridge(br);
193 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
194 memcpy(br->bridge_id.addr, addr, ETH_ALEN);
195 memcpy(br->dev->dev_addr, addr, ETH_ALEN);
197 list_for_each_entry(p, &br->port_list, list) {
198 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
199 memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
201 if (!compare_ether_addr(p->designated_root.addr, oldaddr))
202 memcpy(p->designated_root.addr, addr, ETH_ALEN);
206 br_configuration_update(br);
207 br_port_state_selection(br);
208 if (br_is_root_bridge(br) && !wasroot)
209 br_become_root_bridge(br);
212 /* should be aligned on 2 bytes for compare_ether_addr() */
213 static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
215 /* called under bridge lock */
216 void br_stp_recalculate_bridge_id(struct net_bridge *br)
218 const unsigned char *br_mac_zero =
219 (const unsigned char *)br_mac_zero_aligned;
220 const unsigned char *addr = br_mac_zero;
221 struct net_bridge_port *p;
223 list_for_each_entry(p, &br->port_list, list) {
224 if (addr == br_mac_zero ||
225 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
226 addr = p->dev->dev_addr;
230 if (compare_ether_addr(br->bridge_id.addr, addr))
231 br_stp_change_bridge_id(br, addr);
234 /* called under bridge lock */
235 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
237 struct net_bridge_port *p;
240 wasroot = br_is_root_bridge(br);
242 list_for_each_entry(p, &br->port_list, list) {
243 if (p->state != BR_STATE_DISABLED &&
244 br_is_designated_port(p)) {
245 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
246 p->designated_bridge.prio[1] = newprio & 0xFF;
251 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
252 br->bridge_id.prio[1] = newprio & 0xFF;
253 br_configuration_update(br);
254 br_port_state_selection(br);
255 if (br_is_root_bridge(br) && !wasroot)
256 br_become_root_bridge(br);
259 /* called under bridge lock */
260 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
262 port_id new_port_id = br_make_port_id(newprio, p->port_no);
264 if (br_is_designated_port(p))
265 p->designated_port = new_port_id;
267 p->port_id = new_port_id;
268 p->priority = newprio;
269 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
270 p->port_id < p->designated_port) {
271 br_become_designated_port(p);
272 br_port_state_selection(p->br);
276 /* called under bridge lock */
277 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
279 p->path_cost = path_cost;
280 br_configuration_update(p->br);
281 br_port_state_selection(p->br);
284 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
286 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
287 id->prio[0], id->prio[1],
288 id->addr[0], id->addr[1], id->addr[2],
289 id->addr[3], id->addr[4], id->addr[5]);