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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
31static 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
56static 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
63static 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
71void 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
116void 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
132
133
134
135void 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
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}
220
