Merge branch 'linux-2.6' into for-2.6.22
[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 #include <linux/rtnetlink.h>
20
21 #include "br_private.h"
22 #include "br_private_stp.h"
23
24
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.
28  */
29 static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
30 {
31         return ((u16)priority << BR_PORT_BITS)
32                 | (port_no & ((1<<BR_PORT_BITS)-1));
33 }
34
35 /* called under bridge lock */
36 void br_init_port(struct net_bridge_port *p)
37 {
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;
43 }
44
45 /* called under bridge lock */
46 void br_stp_enable_bridge(struct net_bridge *br)
47 {
48         struct net_bridge_port *p;
49
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);
53
54         br_config_bpdu_generation(br);
55
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);
59
60         }
61         spin_unlock_bh(&br->lock);
62 }
63
64 /* NO locks held */
65 void br_stp_disable_bridge(struct net_bridge *br)
66 {
67         struct net_bridge_port *p;
68
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);
73
74         }
75
76         br->topology_change = 0;
77         br->topology_change_detected = 0;
78         spin_unlock_bh(&br->lock);
79
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);
84 }
85
86 /* called under bridge lock */
87 void br_stp_enable_port(struct net_bridge_port *p)
88 {
89         br_init_port(p);
90         br_port_state_selection(p->br);
91 }
92
93 /* called under bridge lock */
94 void br_stp_disable_port(struct net_bridge_port *p)
95 {
96         struct net_bridge *br;
97         int wasroot;
98
99         br = p->br;
100         printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
101                br->dev->name, p->port_no, p->dev->name, "disabled");
102
103         wasroot = br_is_root_bridge(br);
104         br_become_designated_port(p);
105         p->state = BR_STATE_DISABLED;
106         p->topology_change_ack = 0;
107         p->config_pending = 0;
108
109         del_timer(&p->message_age_timer);
110         del_timer(&p->forward_delay_timer);
111         del_timer(&p->hold_timer);
112
113         br_fdb_delete_by_port(br, p, 0);
114
115         br_configuration_update(br);
116
117         br_port_state_selection(br);
118
119         if (br_is_root_bridge(br) && !wasroot)
120                 br_become_root_bridge(br);
121 }
122
123 static void br_stp_start(struct net_bridge *br)
124 {
125         int r;
126         char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
127         char *envp[] = { NULL };
128
129         r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
130         if (r == 0) {
131                 br->stp_enabled = BR_USER_STP;
132                 printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
133         } else {
134                 br->stp_enabled = BR_KERNEL_STP;
135                 printk(KERN_INFO "%s: starting userspace STP failed, "
136                                 "staring kernel STP\n", br->dev->name);
137
138                 /* To start timers on any ports left in blocking */
139                 spin_lock_bh(&br->lock);
140                 br_port_state_selection(br);
141                 spin_unlock_bh(&br->lock);
142         }
143 }
144
145 static void br_stp_stop(struct net_bridge *br)
146 {
147         int r;
148         char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
149         char *envp[] = { NULL };
150
151         if (br->stp_enabled == BR_USER_STP) {
152                 r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
153                 printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
154                         br->dev->name, r);
155
156
157                 /* To start timers on any ports left in blocking */
158                 spin_lock_bh(&br->lock);
159                 br_port_state_selection(br);
160                 spin_unlock_bh(&br->lock);
161         }
162
163         br->stp_enabled = BR_NO_STP;
164 }
165
166 void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
167 {
168         ASSERT_RTNL();
169
170         if (val) {
171                 if (br->stp_enabled == BR_NO_STP)
172                         br_stp_start(br);
173         } else {
174                 if (br->stp_enabled != BR_NO_STP)
175                         br_stp_stop(br);
176         }
177 }
178
179 /* called under bridge lock */
180 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
181 {
182         /* should be aligned on 2 bytes for compare_ether_addr() */
183         unsigned short oldaddr_aligned[ETH_ALEN >> 1];
184         unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
185         struct net_bridge_port *p;
186         int wasroot;
187
188         wasroot = br_is_root_bridge(br);
189
190         memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
191         memcpy(br->bridge_id.addr, addr, ETH_ALEN);
192         memcpy(br->dev->dev_addr, addr, ETH_ALEN);
193
194         list_for_each_entry(p, &br->port_list, list) {
195                 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
196                         memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
197
198                 if (!compare_ether_addr(p->designated_root.addr, oldaddr))
199                         memcpy(p->designated_root.addr, addr, ETH_ALEN);
200
201         }
202
203         br_configuration_update(br);
204         br_port_state_selection(br);
205         if (br_is_root_bridge(br) && !wasroot)
206                 br_become_root_bridge(br);
207 }
208
209 /* should be aligned on 2 bytes for compare_ether_addr() */
210 static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
211
212 /* called under bridge lock */
213 void br_stp_recalculate_bridge_id(struct net_bridge *br)
214 {
215         const unsigned char *br_mac_zero =
216                         (const unsigned char *)br_mac_zero_aligned;
217         const unsigned char *addr = br_mac_zero;
218         struct net_bridge_port *p;
219
220         list_for_each_entry(p, &br->port_list, list) {
221                 if (addr == br_mac_zero ||
222                     memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
223                         addr = p->dev->dev_addr;
224
225         }
226
227         if (compare_ether_addr(br->bridge_id.addr, addr))
228                 br_stp_change_bridge_id(br, addr);
229 }
230
231 /* called under bridge lock */
232 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
233 {
234         struct net_bridge_port *p;
235         int wasroot;
236
237         wasroot = br_is_root_bridge(br);
238
239         list_for_each_entry(p, &br->port_list, list) {
240                 if (p->state != BR_STATE_DISABLED &&
241                     br_is_designated_port(p)) {
242                         p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
243                         p->designated_bridge.prio[1] = newprio & 0xFF;
244                 }
245
246         }
247
248         br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
249         br->bridge_id.prio[1] = newprio & 0xFF;
250         br_configuration_update(br);
251         br_port_state_selection(br);
252         if (br_is_root_bridge(br) && !wasroot)
253                 br_become_root_bridge(br);
254 }
255
256 /* called under bridge lock */
257 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
258 {
259         port_id new_port_id = br_make_port_id(newprio, p->port_no);
260
261         if (br_is_designated_port(p))
262                 p->designated_port = new_port_id;
263
264         p->port_id = new_port_id;
265         p->priority = newprio;
266         if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
267             p->port_id < p->designated_port) {
268                 br_become_designated_port(p);
269                 br_port_state_selection(p->br);
270         }
271 }
272
273 /* called under bridge lock */
274 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
275 {
276         p->path_cost = path_cost;
277         br_configuration_update(p->br);
278         br_port_state_selection(p->br);
279 }
280
281 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
282 {
283         return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
284                id->prio[0], id->prio[1],
285                id->addr[0], id->addr[1], id->addr[2],
286                id->addr[3], id->addr[4], id->addr[5]);
287 }