Merge branch 'linux-2.6' into for-2.6.24
[pandora-kernel.git] / 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/etherdevice.h>
18 #include <linux/rtnetlink.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_fdb_delete_by_port(br, p, 0);
113
114         br_configuration_update(br);
115
116         br_port_state_selection(br);
117
118         if (br_is_root_bridge(br) && !wasroot)
119                 br_become_root_bridge(br);
120 }
121
122 static void br_stp_start(struct net_bridge *br)
123 {
124         int r;
125         char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
126         char *envp[] = { NULL };
127
128         r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
129         if (r == 0) {
130                 br->stp_enabled = BR_USER_STP;
131                 printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
132         } else {
133                 br->stp_enabled = BR_KERNEL_STP;
134                 printk(KERN_INFO "%s: starting userspace STP failed, "
135                                 "starting kernel STP\n", br->dev->name);
136
137                 /* To start timers on any ports left in blocking */
138                 spin_lock_bh(&br->lock);
139                 br_port_state_selection(br);
140                 spin_unlock_bh(&br->lock);
141         }
142 }
143
144 static void br_stp_stop(struct net_bridge *br)
145 {
146         int r;
147         char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
148         char *envp[] = { NULL };
149
150         if (br->stp_enabled == BR_USER_STP) {
151                 r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
152                 printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
153                         br->dev->name, r);
154
155
156                 /* To start timers on any ports left in blocking */
157                 spin_lock_bh(&br->lock);
158                 br_port_state_selection(br);
159                 spin_unlock_bh(&br->lock);
160         }
161
162         br->stp_enabled = BR_NO_STP;
163 }
164
165 void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
166 {
167         ASSERT_RTNL();
168
169         if (val) {
170                 if (br->stp_enabled == BR_NO_STP)
171                         br_stp_start(br);
172         } else {
173                 if (br->stp_enabled != BR_NO_STP)
174                         br_stp_stop(br);
175         }
176 }
177
178 /* called under bridge lock */
179 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
180 {
181         /* should be aligned on 2 bytes for compare_ether_addr() */
182         unsigned short oldaddr_aligned[ETH_ALEN >> 1];
183         unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
184         struct net_bridge_port *p;
185         int wasroot;
186
187         wasroot = br_is_root_bridge(br);
188
189         memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
190         memcpy(br->bridge_id.addr, addr, ETH_ALEN);
191         memcpy(br->dev->dev_addr, addr, ETH_ALEN);
192
193         list_for_each_entry(p, &br->port_list, list) {
194                 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
195                         memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
196
197                 if (!compare_ether_addr(p->designated_root.addr, oldaddr))
198                         memcpy(p->designated_root.addr, addr, ETH_ALEN);
199
200         }
201
202         br_configuration_update(br);
203         br_port_state_selection(br);
204         if (br_is_root_bridge(br) && !wasroot)
205                 br_become_root_bridge(br);
206 }
207
208 /* should be aligned on 2 bytes for compare_ether_addr() */
209 static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
210
211 /* called under bridge lock */
212 void br_stp_recalculate_bridge_id(struct net_bridge *br)
213 {
214         const unsigned char *br_mac_zero =
215                         (const unsigned char *)br_mac_zero_aligned;
216         const unsigned char *addr = br_mac_zero;
217         struct net_bridge_port *p;
218
219         list_for_each_entry(p, &br->port_list, list) {
220                 if (addr == br_mac_zero ||
221                     memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
222                         addr = p->dev->dev_addr;
223
224         }
225
226         if (compare_ether_addr(br->bridge_id.addr, addr))
227                 br_stp_change_bridge_id(br, addr);
228 }
229
230 /* called under bridge lock */
231 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
232 {
233         struct net_bridge_port *p;
234         int wasroot;
235
236         wasroot = br_is_root_bridge(br);
237
238         list_for_each_entry(p, &br->port_list, list) {
239                 if (p->state != BR_STATE_DISABLED &&
240                     br_is_designated_port(p)) {
241                         p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
242                         p->designated_bridge.prio[1] = newprio & 0xFF;
243                 }
244
245         }
246
247         br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
248         br->bridge_id.prio[1] = newprio & 0xFF;
249         br_configuration_update(br);
250         br_port_state_selection(br);
251         if (br_is_root_bridge(br) && !wasroot)
252                 br_become_root_bridge(br);
253 }
254
255 /* called under bridge lock */
256 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
257 {
258         port_id new_port_id = br_make_port_id(newprio, p->port_no);
259
260         if (br_is_designated_port(p))
261                 p->designated_port = new_port_id;
262
263         p->port_id = new_port_id;
264         p->priority = newprio;
265         if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
266             p->port_id < p->designated_port) {
267                 br_become_designated_port(p);
268                 br_port_state_selection(p->br);
269         }
270 }
271
272 /* called under bridge lock */
273 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
274 {
275         p->path_cost = path_cost;
276         br_configuration_update(p->br);
277         br_port_state_selection(p->br);
278 }
279
280 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
281 {
282         return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
283                id->prio[0], id->prio[1],
284                id->addr[0], id->addr[1], id->addr[2],
285                id->addr[3], id->addr[4], id->addr[5]);
286 }