microblaze: uaccess: fix put_user and get_user macros
[linux-2.6.git] / net / bridge / br_stp_bpdu.c
1 /*
2  *      Spanning tree protocol; BPDU handling
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/netfilter_bridge.h>
16 #include <linux/etherdevice.h>
17 #include <linux/llc.h>
18 #include <net/net_namespace.h>
19 #include <net/llc.h>
20 #include <net/llc_pdu.h>
21 #include <net/stp.h>
22 #include <asm/unaligned.h>
23
24 #include "br_private.h"
25 #include "br_private_stp.h"
26
27 #define STP_HZ          256
28
29 #define LLC_RESERVE sizeof(struct llc_pdu_un)
30
31 static void br_send_bpdu(struct net_bridge_port *p,
32                          const unsigned char *data, int length)
33 {
34         struct sk_buff *skb;
35
36         skb = dev_alloc_skb(length+LLC_RESERVE);
37         if (!skb)
38                 return;
39
40         skb->dev = p->dev;
41         skb->protocol = htons(ETH_P_802_2);
42
43         skb_reserve(skb, LLC_RESERVE);
44         memcpy(__skb_put(skb, length), data, length);
45
46         llc_pdu_header_init(skb, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
47                             LLC_SAP_BSPAN, LLC_PDU_CMD);
48         llc_pdu_init_as_ui_cmd(skb);
49
50         llc_mac_hdr_init(skb, p->dev->dev_addr, p->br->group_addr);
51
52         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
53                 dev_queue_xmit);
54 }
55
56 static inline void br_set_ticks(unsigned char *dest, int j)
57 {
58         unsigned long ticks = (STP_HZ * j)/ HZ;
59
60         put_unaligned_be16(ticks, dest);
61 }
62
63 static inline int br_get_ticks(const unsigned char *src)
64 {
65         unsigned long ticks = get_unaligned_be16(src);
66
67         return DIV_ROUND_UP(ticks * HZ, STP_HZ);
68 }
69
70 /* called under bridge lock */
71 void br_send_config_bpdu(struct net_bridge_port *p, struct br_config_bpdu *bpdu)
72 {
73         unsigned char buf[35];
74
75         if (p->br->stp_enabled != BR_KERNEL_STP)
76                 return;
77
78         buf[0] = 0;
79         buf[1] = 0;
80         buf[2] = 0;
81         buf[3] = BPDU_TYPE_CONFIG;
82         buf[4] = (bpdu->topology_change ? 0x01 : 0) |
83                 (bpdu->topology_change_ack ? 0x80 : 0);
84         buf[5] = bpdu->root.prio[0];
85         buf[6] = bpdu->root.prio[1];
86         buf[7] = bpdu->root.addr[0];
87         buf[8] = bpdu->root.addr[1];
88         buf[9] = bpdu->root.addr[2];
89         buf[10] = bpdu->root.addr[3];
90         buf[11] = bpdu->root.addr[4];
91         buf[12] = bpdu->root.addr[5];
92         buf[13] = (bpdu->root_path_cost >> 24) & 0xFF;
93         buf[14] = (bpdu->root_path_cost >> 16) & 0xFF;
94         buf[15] = (bpdu->root_path_cost >> 8) & 0xFF;
95         buf[16] = bpdu->root_path_cost & 0xFF;
96         buf[17] = bpdu->bridge_id.prio[0];
97         buf[18] = bpdu->bridge_id.prio[1];
98         buf[19] = bpdu->bridge_id.addr[0];
99         buf[20] = bpdu->bridge_id.addr[1];
100         buf[21] = bpdu->bridge_id.addr[2];
101         buf[22] = bpdu->bridge_id.addr[3];
102         buf[23] = bpdu->bridge_id.addr[4];
103         buf[24] = bpdu->bridge_id.addr[5];
104         buf[25] = (bpdu->port_id >> 8) & 0xFF;
105         buf[26] = bpdu->port_id & 0xFF;
106
107         br_set_ticks(buf+27, bpdu->message_age);
108         br_set_ticks(buf+29, bpdu->max_age);
109         br_set_ticks(buf+31, bpdu->hello_time);
110         br_set_ticks(buf+33, bpdu->forward_delay);
111
112         br_send_bpdu(p, buf, 35);
113 }
114
115 /* called under bridge lock */
116 void br_send_tcn_bpdu(struct net_bridge_port *p)
117 {
118         unsigned char buf[4];
119
120         if (p->br->stp_enabled != BR_KERNEL_STP)
121                 return;
122
123         buf[0] = 0;
124         buf[1] = 0;
125         buf[2] = 0;
126         buf[3] = BPDU_TYPE_TCN;
127         br_send_bpdu(p, buf, 4);
128 }
129
130 /*
131  * Called from llc.
132  *
133  * NO locks, but rcu_read_lock (preempt_disabled)
134  */
135 void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
136                 struct net_device *dev)
137 {
138         const unsigned char *dest = eth_hdr(skb)->h_dest;
139         struct net_bridge_port *p = rcu_dereference(dev->br_port);
140         struct net_bridge *br;
141         const unsigned char *buf;
142
143         if (!p)
144                 goto err;
145
146         if (!pskb_may_pull(skb, 4))
147                 goto err;
148
149         /* compare of protocol id and version */
150         buf = skb->data;
151         if (buf[0] != 0 || buf[1] != 0 || buf[2] != 0)
152                 goto err;
153
154         br = p->br;
155         spin_lock(&br->lock);
156
157         if (br->stp_enabled != BR_KERNEL_STP)
158                 goto out;
159
160         if (!(br->dev->flags & IFF_UP))
161                 goto out;
162
163         if (p->state == BR_STATE_DISABLED)
164                 goto out;
165
166         if (compare_ether_addr(dest, br->group_addr) != 0)
167                 goto out;
168
169         buf = skb_pull(skb, 3);
170
171         if (buf[0] == BPDU_TYPE_CONFIG) {
172                 struct br_config_bpdu bpdu;
173
174                 if (!pskb_may_pull(skb, 32))
175                         goto out;
176
177                 buf = skb->data;
178                 bpdu.topology_change = (buf[1] & 0x01) ? 1 : 0;
179                 bpdu.topology_change_ack = (buf[1] & 0x80) ? 1 : 0;
180
181                 bpdu.root.prio[0] = buf[2];
182                 bpdu.root.prio[1] = buf[3];
183                 bpdu.root.addr[0] = buf[4];
184                 bpdu.root.addr[1] = buf[5];
185                 bpdu.root.addr[2] = buf[6];
186                 bpdu.root.addr[3] = buf[7];
187                 bpdu.root.addr[4] = buf[8];
188                 bpdu.root.addr[5] = buf[9];
189                 bpdu.root_path_cost =
190                         (buf[10] << 24) |
191                         (buf[11] << 16) |
192                         (buf[12] << 8) |
193                         buf[13];
194                 bpdu.bridge_id.prio[0] = buf[14];
195                 bpdu.bridge_id.prio[1] = buf[15];
196                 bpdu.bridge_id.addr[0] = buf[16];
197                 bpdu.bridge_id.addr[1] = buf[17];
198                 bpdu.bridge_id.addr[2] = buf[18];
199                 bpdu.bridge_id.addr[3] = buf[19];
200                 bpdu.bridge_id.addr[4] = buf[20];
201                 bpdu.bridge_id.addr[5] = buf[21];
202                 bpdu.port_id = (buf[22] << 8) | buf[23];
203
204                 bpdu.message_age = br_get_ticks(buf+24);
205                 bpdu.max_age = br_get_ticks(buf+26);
206                 bpdu.hello_time = br_get_ticks(buf+28);
207                 bpdu.forward_delay = br_get_ticks(buf+30);
208
209                 br_received_config_bpdu(p, &bpdu);
210         }
211
212         else if (buf[0] == BPDU_TYPE_TCN) {
213                 br_received_tcn_bpdu(p);
214         }
215  out:
216         spin_unlock(&br->lock);
217  err:
218         kfree_skb(skb);
219 }