blob: 5881fbc114a9ec88612fd08f35a73d2794d56890 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Spanning tree protocol; BPDU handling
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * 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>
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -080016#include <linux/etherdevice.h>
17#include <linux/llc.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Stephen Hemminger547b4e72013-02-11 08:22:22 +000019#include <linux/pkt_sched.h>
Eric W. Biedermane730c152007-09-17 11:53:39 -070020#include <net/net_namespace.h>
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080021#include <net/llc.h>
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -080022#include <net/llc_pdu.h>
Patrick McHardy7c85fbf2008-07-05 21:25:56 -070023#include <net/stp.h>
Peter Chubb4dc6d9c2006-03-23 21:39:47 -080024#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26#include "br_private.h"
27#include "br_private_stp.h"
28
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080029#define STP_HZ 256
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080031#define LLC_RESERVE sizeof(struct llc_pdu_un)
32
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -050033static int br_send_bpdu_finish(struct net *net, struct sock *sk,
34 struct sk_buff *skb)
Eric W. Biederman1f19c572015-09-15 20:04:06 -050035{
36 return dev_queue_xmit(skb);
37}
38
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080039static void br_send_bpdu(struct net_bridge_port *p,
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090040 const unsigned char *data, int length)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041{
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080044 skb = dev_alloc_skb(length+LLC_RESERVE);
45 if (!skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080048 skb->dev = p->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 skb->protocol = htons(ETH_P_802_2);
Stephen Hemminger547b4e72013-02-11 08:22:22 +000050 skb->priority = TC_PRIO_CONTROL;
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080051
52 skb_reserve(skb, LLC_RESERVE);
53 memcpy(__skb_put(skb, length), data, length);
54
55 llc_pdu_header_init(skb, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
56 LLC_SAP_BSPAN, LLC_PDU_CMD);
57 llc_pdu_init_as_ui_cmd(skb);
58
59 llc_mac_hdr_init(skb, p->dev->dev_addr, p->br->group_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
Florian Westphale6f26122011-01-03 04:16:28 +000061 skb_reset_mac_header(skb);
62
Eric W. Biederman29a26a52015-09-15 20:04:16 -050063 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT,
64 dev_net(p->dev), NULL, skb, NULL, skb->dev,
Eric W. Biederman1f19c572015-09-15 20:04:06 -050065 br_send_bpdu_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066}
67
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080068static inline void br_set_ticks(unsigned char *dest, int j)
Linus Torvalds1da177e2005-04-16 15:20:36 -070069{
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080070 unsigned long ticks = (STP_HZ * j)/ HZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
Harvey Harrisond3e2ce32008-05-02 16:26:16 -070072 put_unaligned_be16(ticks, dest);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073}
74
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080075static inline int br_get_ticks(const unsigned char *src)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076{
Harvey Harrisond3e2ce32008-05-02 16:26:16 -070077 unsigned long ticks = get_unaligned_be16(src);
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080078
Ilpo Järvinen172589c2007-08-28 15:50:33 -070079 return DIV_ROUND_UP(ticks * HZ, STP_HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080}
81
82/* called under bridge lock */
83void br_send_config_bpdu(struct net_bridge_port *p, struct br_config_bpdu *bpdu)
84{
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080085 unsigned char buf[35];
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Stephen Hemminger9cde0702007-03-21 14:22:44 -070087 if (p->br->stp_enabled != BR_KERNEL_STP)
88 return;
89
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080090 buf[0] = 0;
91 buf[1] = 0;
92 buf[2] = 0;
93 buf[3] = BPDU_TYPE_CONFIG;
94 buf[4] = (bpdu->topology_change ? 0x01 : 0) |
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 (bpdu->topology_change_ack ? 0x80 : 0);
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080096 buf[5] = bpdu->root.prio[0];
97 buf[6] = bpdu->root.prio[1];
98 buf[7] = bpdu->root.addr[0];
99 buf[8] = bpdu->root.addr[1];
100 buf[9] = bpdu->root.addr[2];
101 buf[10] = bpdu->root.addr[3];
102 buf[11] = bpdu->root.addr[4];
103 buf[12] = bpdu->root.addr[5];
104 buf[13] = (bpdu->root_path_cost >> 24) & 0xFF;
105 buf[14] = (bpdu->root_path_cost >> 16) & 0xFF;
106 buf[15] = (bpdu->root_path_cost >> 8) & 0xFF;
107 buf[16] = bpdu->root_path_cost & 0xFF;
108 buf[17] = bpdu->bridge_id.prio[0];
109 buf[18] = bpdu->bridge_id.prio[1];
110 buf[19] = bpdu->bridge_id.addr[0];
111 buf[20] = bpdu->bridge_id.addr[1];
112 buf[21] = bpdu->bridge_id.addr[2];
113 buf[22] = bpdu->bridge_id.addr[3];
114 buf[23] = bpdu->bridge_id.addr[4];
115 buf[24] = bpdu->bridge_id.addr[5];
116 buf[25] = (bpdu->port_id >> 8) & 0xFF;
117 buf[26] = bpdu->port_id & 0xFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800119 br_set_ticks(buf+27, bpdu->message_age);
120 br_set_ticks(buf+29, bpdu->max_age);
121 br_set_ticks(buf+31, bpdu->hello_time);
122 br_set_ticks(buf+33, bpdu->forward_delay);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800124 br_send_bpdu(p, buf, 35);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125}
126
127/* called under bridge lock */
128void br_send_tcn_bpdu(struct net_bridge_port *p)
129{
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800130 unsigned char buf[4];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700132 if (p->br->stp_enabled != BR_KERNEL_STP)
133 return;
134
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800135 buf[0] = 0;
136 buf[1] = 0;
137 buf[2] = 0;
138 buf[3] = BPDU_TYPE_TCN;
Stephen Hemminger485c2962006-09-13 20:12:40 -0700139 br_send_bpdu(p, buf, 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140}
141
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800142/*
143 * Called from llc.
144 *
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000145 * NO locks, but rcu_read_lock
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800146 */
Patrick McHardy7c85fbf2008-07-05 21:25:56 -0700147void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
148 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149{
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800150 const unsigned char *dest = eth_hdr(skb)->h_dest;
Jiri Pirkof350a0a82010-06-15 06:50:45 +0000151 struct net_bridge_port *p;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800152 struct net_bridge *br;
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800153 const unsigned char *buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800155 if (!pskb_may_pull(skb, 4))
156 goto err;
157
158 /* compare of protocol id and version */
159 buf = skb->data;
160 if (buf[0] != 0 || buf[1] != 0 || buf[2] != 0)
161 goto err;
162
Jiri Pirko859828c2013-12-05 16:27:37 +0100163 p = br_port_get_check_rcu(dev);
stephen hemmingerb5ed54e2010-11-15 06:38:13 +0000164 if (!p)
165 goto err;
166
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800167 br = p->br;
168 spin_lock(&br->lock);
169
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700170 if (br->stp_enabled != BR_KERNEL_STP)
171 goto out;
172
173 if (!(br->dev->flags & IFF_UP))
174 goto out;
175
176 if (p->state == BR_STATE_DISABLED)
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800177 goto out;
178
Joe Perches9a7b6ef92012-05-08 18:56:49 +0000179 if (!ether_addr_equal(dest, br->group_addr))
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800180 goto out;
Stephen Hemminger85967bb2005-05-29 14:15:55 -0700181
stephen hemmingera2e01a62012-11-13 07:53:07 +0000182 if (p->flags & BR_BPDU_GUARD) {
183 br_notice(br, "BPDU received on blocked port %u(%s)\n",
184 (unsigned int) p->port_no, p->dev->name);
185 br_stp_disable_port(p);
186 goto out;
187 }
188
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800189 buf = skb_pull(skb, 3);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 if (buf[0] == BPDU_TYPE_CONFIG) {
192 struct br_config_bpdu bpdu;
193
194 if (!pskb_may_pull(skb, 32))
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800195 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
197 buf = skb->data;
198 bpdu.topology_change = (buf[1] & 0x01) ? 1 : 0;
199 bpdu.topology_change_ack = (buf[1] & 0x80) ? 1 : 0;
200
201 bpdu.root.prio[0] = buf[2];
202 bpdu.root.prio[1] = buf[3];
203 bpdu.root.addr[0] = buf[4];
204 bpdu.root.addr[1] = buf[5];
205 bpdu.root.addr[2] = buf[6];
206 bpdu.root.addr[3] = buf[7];
207 bpdu.root.addr[4] = buf[8];
208 bpdu.root.addr[5] = buf[9];
209 bpdu.root_path_cost =
210 (buf[10] << 24) |
211 (buf[11] << 16) |
212 (buf[12] << 8) |
213 buf[13];
214 bpdu.bridge_id.prio[0] = buf[14];
215 bpdu.bridge_id.prio[1] = buf[15];
216 bpdu.bridge_id.addr[0] = buf[16];
217 bpdu.bridge_id.addr[1] = buf[17];
218 bpdu.bridge_id.addr[2] = buf[18];
219 bpdu.bridge_id.addr[3] = buf[19];
220 bpdu.bridge_id.addr[4] = buf[20];
221 bpdu.bridge_id.addr[5] = buf[21];
222 bpdu.port_id = (buf[22] << 8) | buf[23];
223
224 bpdu.message_age = br_get_ticks(buf+24);
225 bpdu.max_age = br_get_ticks(buf+26);
226 bpdu.hello_time = br_get_ticks(buf+28);
227 bpdu.forward_delay = br_get_ticks(buf+30);
228
stephen hemminger0652cac2011-07-22 07:47:07 +0000229 if (bpdu.message_age > bpdu.max_age) {
230 if (net_ratelimit())
231 br_notice(p->br,
232 "port %u config from %pM"
233 " (message_age %ul > max_age %ul)\n",
234 p->port_no,
235 eth_hdr(skb)->h_source,
236 bpdu.message_age, bpdu.max_age);
237 goto out;
238 }
239
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 br_received_config_bpdu(p, &bpdu);
stephen hemminger160d73b2011-07-22 07:47:10 +0000241 } else if (buf[0] == BPDU_TYPE_TCN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 br_received_tcn_bpdu(p);
243 }
244 out:
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800245 spin_unlock(&br->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 err:
247 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248}