arm: tegra: enterprise: Controls for 3d barrier
[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         br_ifinfo_notify(RTM_NEWLINK, p);
92 }
93
94 /* called under bridge lock */
95 void br_stp_disable_port(struct net_bridge_port *p)
96 {
97         struct net_bridge *br = p->br;
98         int wasroot;
99
100         br_log_state(p);
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         br_ifinfo_notify(RTM_NEWLINK, p);
109
110         del_timer(&p->message_age_timer);
111         del_timer(&p->forward_delay_timer);
112         del_timer(&p->hold_timer);
113
114         br_fdb_delete_by_port(br, p, 0);
115         br_multicast_disable_port(p);
116
117         br_configuration_update(br);
118
119         br_port_state_selection(br);
120
121         if (br_is_root_bridge(br) && !wasroot)
122                 br_become_root_bridge(br);
123 }
124
125 static void br_stp_start(struct net_bridge *br)
126 {
127         int r;
128         char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
129         char *envp[] = { NULL };
130
131         r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
132         if (r == 0) {
133                 br->stp_enabled = BR_USER_STP;
134                 br_debug(br, "userspace STP started\n");
135         } else {
136                 br->stp_enabled = BR_KERNEL_STP;
137                 br_debug(br, "using kernel STP\n");
138
139                 /* To start timers on any ports left in blocking */
140                 spin_lock_bh(&br->lock);
141                 br_port_state_selection(br);
142                 spin_unlock_bh(&br->lock);
143         }
144 }
145
146 static void br_stp_stop(struct net_bridge *br)
147 {
148         int r;
149         char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
150         char *envp[] = { NULL };
151
152         if (br->stp_enabled == BR_USER_STP) {
153                 r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
154                 br_info(br, "userspace STP stopped, return code %d\n", r);
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 bool 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         /* user has chosen a value so keep it */
220         if (br->flags & BR_SET_MAC_ADDR)
221                 return false;
222
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;
227
228         }
229
230         if (compare_ether_addr(br->bridge_id.addr, addr) == 0)
231                 return false;   /* no change */
232
233         br_stp_change_bridge_id(br, addr);
234         return true;
235 }
236
237 /* called under bridge lock */
238 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
239 {
240         struct net_bridge_port *p;
241         int wasroot;
242
243         wasroot = br_is_root_bridge(br);
244
245         list_for_each_entry(p, &br->port_list, list) {
246                 if (p->state != BR_STATE_DISABLED &&
247                     br_is_designated_port(p)) {
248                         p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
249                         p->designated_bridge.prio[1] = newprio & 0xFF;
250                 }
251
252         }
253
254         br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
255         br->bridge_id.prio[1] = newprio & 0xFF;
256         br_configuration_update(br);
257         br_port_state_selection(br);
258         if (br_is_root_bridge(br) && !wasroot)
259                 br_become_root_bridge(br);
260 }
261
262 /* called under bridge lock */
263 int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
264 {
265         port_id new_port_id;
266
267         if (newprio > BR_MAX_PORT_PRIORITY)
268                 return -ERANGE;
269
270         new_port_id = br_make_port_id(newprio, p->port_no);
271         if (br_is_designated_port(p))
272                 p->designated_port = new_port_id;
273
274         p->port_id = new_port_id;
275         p->priority = newprio;
276         if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
277             p->port_id < p->designated_port) {
278                 br_become_designated_port(p);
279                 br_port_state_selection(p->br);
280         }
281
282         return 0;
283 }
284
285 /* called under bridge lock */
286 int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
287 {
288         if (path_cost < BR_MIN_PATH_COST ||
289             path_cost > BR_MAX_PATH_COST)
290                 return -ERANGE;
291
292         p->path_cost = path_cost;
293         br_configuration_update(p->br);
294         br_port_state_selection(p->br);
295         return 0;
296 }
297
298 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
299 {
300         return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
301                id->prio[0], id->prio[1],
302                id->addr[0], id->addr[1], id->addr[2],
303                id->addr[3], id->addr[4], id->addr[5]);
304 }