Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6.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  *      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.
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/etherdevice.h>
16 #include <linux/rtnetlink.h>
17
18 #include "br_private.h"
19 #include "br_private_stp.h"
20
21
22 /* Port id is composed of priority and port number.
23  * NB: some bits of priority are dropped to
24  *     make room for more ports.
25  */
26 static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
27 {
28         return ((u16)priority << BR_PORT_BITS)
29                 | (port_no & ((1<<BR_PORT_BITS)-1));
30 }
31
32 #define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
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         br_log_state(p);
91 }
92
93 /* called under bridge lock */
94 void br_stp_disable_port(struct net_bridge_port *p)
95 {
96         struct net_bridge *br = p->br;
97         int wasroot;
98
99         br_log_state(p);
100
101         wasroot = br_is_root_bridge(br);
102         br_become_designated_port(p);
103         p->state = BR_STATE_DISABLED;
104         p->topology_change_ack = 0;
105         p->config_pending = 0;
106
107         del_timer(&p->message_age_timer);
108         del_timer(&p->forward_delay_timer);
109         del_timer(&p->hold_timer);
110
111         br_fdb_delete_by_port(br, p, 0);
112         br_multicast_disable_port(p);
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                 br_debug(br, "userspace STP started\n");
132         } else {
133                 br->stp_enabled = BR_KERNEL_STP;
134                 br_debug(br, "using kernel STP\n");
135
136                 /* To start timers on any ports left in blocking */
137                 spin_lock_bh(&br->lock);
138                 br_port_state_selection(br);
139                 spin_unlock_bh(&br->lock);
140         }
141 }
142
143 static void br_stp_stop(struct net_bridge *br)
144 {
145         int r;
146         char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
147         char *envp[] = { NULL };
148
149         if (br->stp_enabled == BR_USER_STP) {
150                 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
151                 br_info(br, "userspace STP stopped, return code %d\n", r);
152
153                 /* To start timers on any ports left in blocking */
154                 spin_lock_bh(&br->lock);
155                 br_port_state_selection(br);
156                 spin_unlock_bh(&br->lock);
157         }
158
159         br->stp_enabled = BR_NO_STP;
160 }
161
162 void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
163 {
164         ASSERT_RTNL();
165
166         if (val) {
167                 if (br->stp_enabled == BR_NO_STP)
168                         br_stp_start(br);
169         } else {
170                 if (br->stp_enabled != BR_NO_STP)
171                         br_stp_stop(br);
172         }
173 }
174
175 /* called under bridge lock */
176 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
177 {
178         /* should be aligned on 2 bytes for compare_ether_addr() */
179         unsigned short oldaddr_aligned[ETH_ALEN >> 1];
180         unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
181         struct net_bridge_port *p;
182         int wasroot;
183
184         wasroot = br_is_root_bridge(br);
185
186         memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
187         memcpy(br->bridge_id.addr, addr, ETH_ALEN);
188         memcpy(br->dev->dev_addr, addr, ETH_ALEN);
189
190         list_for_each_entry(p, &br->port_list, list) {
191                 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
192                         memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
193
194                 if (!compare_ether_addr(p->designated_root.addr, oldaddr))
195                         memcpy(p->designated_root.addr, addr, ETH_ALEN);
196
197         }
198
199         br_configuration_update(br);
200         br_port_state_selection(br);
201         if (br_is_root_bridge(br) && !wasroot)
202                 br_become_root_bridge(br);
203 }
204
205 /* should be aligned on 2 bytes for compare_ether_addr() */
206 static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
207
208 /* called under bridge lock */
209 bool br_stp_recalculate_bridge_id(struct net_bridge *br)
210 {
211         const unsigned char *br_mac_zero =
212                         (const unsigned char *)br_mac_zero_aligned;
213         const unsigned char *addr = br_mac_zero;
214         struct net_bridge_port *p;
215
216         /* user has chosen a value so keep it */
217         if (br->flags & BR_SET_MAC_ADDR)
218                 return false;
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) == 0)
228                 return false;   /* no change */
229
230         br_stp_change_bridge_id(br, addr);
231         return true;
232 }
233
234 /* called under bridge lock */
235 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
236 {
237         struct net_bridge_port *p;
238         int wasroot;
239
240         wasroot = br_is_root_bridge(br);
241
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;
247                 }
248
249         }
250
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);
257 }
258
259 /* called under bridge lock */
260 int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
261 {
262         port_id new_port_id;
263
264         if (newprio > BR_MAX_PORT_PRIORITY)
265                 return -ERANGE;
266
267         new_port_id = br_make_port_id(newprio, p->port_no);
268         if (br_is_designated_port(p))
269                 p->designated_port = new_port_id;
270
271         p->port_id = new_port_id;
272         p->priority = newprio;
273         if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
274             p->port_id < p->designated_port) {
275                 br_become_designated_port(p);
276                 br_port_state_selection(p->br);
277         }
278
279         return 0;
280 }
281
282 /* called under bridge lock */
283 int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
284 {
285         if (path_cost < BR_MIN_PATH_COST ||
286             path_cost > BR_MAX_PATH_COST)
287                 return -ERANGE;
288
289         p->path_cost = path_cost;
290         br_configuration_update(p->br);
291         br_port_state_selection(p->br);
292         return 0;
293 }
294
295 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
296 {
297         return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
298                id->prio[0], id->prio[1],
299                id->addr[0], id->addr[1], id->addr[2],
300                id->addr[3], id->addr[4], id->addr[5]);
301 }