Merge branch 'master' into upstream
[linux-2.6] / net / bridge / br_stp_if.c
1 /*
2  *      Spanning tree protocol; interface code
3  *      Linux ethernet bridge
4  *
5  *      Authors:
6  *      Lennert Buytenhek               <buytenh@gnu.org>
7  *
8  *      $Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 davem Exp $
9  *
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.
14  */
15
16 #include <linux/kernel.h>
17 #include <linux/smp_lock.h>
18 #include <linux/etherdevice.h>
19
20 #include "br_private.h"
21 #include "br_private_stp.h"
22
23
24 /* Port id is composed of priority and port number.
25  * NB: least significant bits of priority are dropped to
26  *     make room for more ports.
27  */
28 static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
29 {
30         return ((u16)priority << BR_PORT_BITS) 
31                 | (port_no & ((1<<BR_PORT_BITS)-1));
32 }
33
34 /* called under bridge lock */
35 void br_init_port(struct net_bridge_port *p)
36 {
37         p->port_id = br_make_port_id(p->priority, p->port_no);
38         br_become_designated_port(p);
39         p->state = BR_STATE_BLOCKING;
40         p->topology_change_ack = 0;
41         p->config_pending = 0;
42 }
43
44 /* called under bridge lock */
45 void br_stp_enable_bridge(struct net_bridge *br)
46 {
47         struct net_bridge_port *p;
48
49         spin_lock_bh(&br->lock);
50         mod_timer(&br->hello_timer, jiffies + br->hello_time);
51         mod_timer(&br->gc_timer, jiffies + HZ/10);
52         
53         br_config_bpdu_generation(br);
54
55         list_for_each_entry(p, &br->port_list, list) {
56                 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
57                         br_stp_enable_port(p);
58
59         }
60         spin_unlock_bh(&br->lock);
61 }
62
63 /* NO locks held */
64 void br_stp_disable_bridge(struct net_bridge *br)
65 {
66         struct net_bridge_port *p;
67
68         spin_lock_bh(&br->lock);
69         list_for_each_entry(p, &br->port_list, list) {
70                 if (p->state != BR_STATE_DISABLED)
71                         br_stp_disable_port(p);
72
73         }
74
75         br->topology_change = 0;
76         br->topology_change_detected = 0;
77         spin_unlock_bh(&br->lock);
78
79         del_timer_sync(&br->hello_timer);
80         del_timer_sync(&br->topology_change_timer);
81         del_timer_sync(&br->tcn_timer);
82         del_timer_sync(&br->gc_timer);
83 }
84
85 /* called under bridge lock */
86 void br_stp_enable_port(struct net_bridge_port *p)
87 {
88         br_init_port(p);
89         br_port_state_selection(p->br);
90 }
91
92 /* called under bridge lock */
93 void br_stp_disable_port(struct net_bridge_port *p)
94 {
95         struct net_bridge *br;
96         int wasroot;
97
98         br = p->br;
99         printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
100                br->dev->name, p->port_no, p->dev->name, "disabled");
101
102         wasroot = br_is_root_bridge(br);
103         br_become_designated_port(p);
104         p->state = BR_STATE_DISABLED;
105         p->topology_change_ack = 0;
106         p->config_pending = 0;
107
108         del_timer(&p->message_age_timer);
109         del_timer(&p->forward_delay_timer);
110         del_timer(&p->hold_timer);
111
112         br_configuration_update(br);
113
114         br_port_state_selection(br);
115
116         if (br_is_root_bridge(br) && !wasroot)
117                 br_become_root_bridge(br);
118 }
119
120 /* called under bridge lock */
121 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
122 {
123         unsigned char oldaddr[6];
124         struct net_bridge_port *p;
125         int wasroot;
126
127         wasroot = br_is_root_bridge(br);
128
129         memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
130         memcpy(br->bridge_id.addr, addr, ETH_ALEN);
131         memcpy(br->dev->dev_addr, addr, ETH_ALEN);
132
133         list_for_each_entry(p, &br->port_list, list) {
134                 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
135                         memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
136
137                 if (!compare_ether_addr(p->designated_root.addr, oldaddr))
138                         memcpy(p->designated_root.addr, addr, ETH_ALEN);
139
140         }
141
142         br_configuration_update(br);
143         br_port_state_selection(br);
144         if (br_is_root_bridge(br) && !wasroot)
145                 br_become_root_bridge(br);
146 }
147
148 static const unsigned char br_mac_zero[6];
149
150 /* called under bridge lock */
151 void br_stp_recalculate_bridge_id(struct net_bridge *br)
152 {
153         const unsigned char *addr = br_mac_zero;
154         struct net_bridge_port *p;
155
156         list_for_each_entry(p, &br->port_list, list) {
157                 if (addr == br_mac_zero ||
158                     memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
159                         addr = p->dev->dev_addr;
160
161         }
162
163         if (compare_ether_addr(br->bridge_id.addr, addr))
164                 br_stp_change_bridge_id(br, addr);
165 }
166
167 /* called under bridge lock */
168 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
169 {
170         struct net_bridge_port *p;
171         int wasroot;
172
173         wasroot = br_is_root_bridge(br);
174
175         list_for_each_entry(p, &br->port_list, list) {
176                 if (p->state != BR_STATE_DISABLED &&
177                     br_is_designated_port(p)) {
178                         p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
179                         p->designated_bridge.prio[1] = newprio & 0xFF;
180                 }
181
182         }
183
184         br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
185         br->bridge_id.prio[1] = newprio & 0xFF;
186         br_configuration_update(br);
187         br_port_state_selection(br);
188         if (br_is_root_bridge(br) && !wasroot)
189                 br_become_root_bridge(br);
190 }
191
192 /* called under bridge lock */
193 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
194 {
195         port_id new_port_id = br_make_port_id(newprio, p->port_no);
196
197         if (br_is_designated_port(p))
198                 p->designated_port = new_port_id;
199
200         p->port_id = new_port_id;
201         p->priority = newprio;
202         if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
203             p->port_id < p->designated_port) {
204                 br_become_designated_port(p);
205                 br_port_state_selection(p->br);
206         }
207 }
208
209 /* called under bridge lock */
210 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
211 {
212         p->path_cost = path_cost;
213         br_configuration_update(p->br);
214         br_port_state_selection(p->br);
215 }
216
217 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
218 {
219         return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
220                id->prio[0], id->prio[1],
221                id->addr[0], id->addr[1], id->addr[2],
222                id->addr[3], id->addr[4], id->addr[5]);
223 }