Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Spanning tree protocol; BPDU handling |
| 3 | * Linux ethernet bridge |
| 4 | * |
| 5 | * Authors: |
| 6 | * Lennert Buytenhek <buytenh@gnu.org> |
| 7 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 16 | #include <linux/etherdevice.h> |
| 17 | #include <linux/llc.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 18 | #include <linux/slab.h> |
Eric W. Biederman | e730c15 | 2007-09-17 11:53:39 -0700 | [diff] [blame] | 19 | #include <net/net_namespace.h> |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 20 | #include <net/llc.h> |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 21 | #include <net/llc_pdu.h> |
Patrick McHardy | 7c85fbf | 2008-07-05 21:25:56 -0700 | [diff] [blame] | 22 | #include <net/stp.h> |
Peter Chubb | 4dc6d9c | 2006-03-23 21:39:47 -0800 | [diff] [blame] | 23 | #include <asm/unaligned.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
| 25 | #include "br_private.h" |
| 26 | #include "br_private_stp.h" |
| 27 | |
Stephen Hemminger | 18fdb2b | 2006-03-20 22:58:49 -0800 | [diff] [blame] | 28 | #define STP_HZ 256 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 30 | #define LLC_RESERVE sizeof(struct llc_pdu_un) |
| 31 | |
| 32 | static void br_send_bpdu(struct net_bridge_port *p, |
YOSHIFUJI Hideaki | 9d6f229 | 2007-02-09 23:24:35 +0900 | [diff] [blame] | 33 | const unsigned char *data, int length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | struct sk_buff *skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 37 | skb = dev_alloc_skb(length+LLC_RESERVE); |
| 38 | if (!skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 41 | skb->dev = p->dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | skb->protocol = htons(ETH_P_802_2); |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 43 | |
| 44 | skb_reserve(skb, LLC_RESERVE); |
| 45 | memcpy(__skb_put(skb, length), data, length); |
| 46 | |
| 47 | llc_pdu_header_init(skb, LLC_PDU_TYPE_U, LLC_SAP_BSPAN, |
| 48 | LLC_SAP_BSPAN, LLC_PDU_CMD); |
| 49 | llc_pdu_init_as_ui_cmd(skb); |
| 50 | |
| 51 | llc_mac_hdr_init(skb, p->dev->dev_addr, p->br->group_addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
Florian Westphal | e6f2612 | 2011-01-03 04:16:28 +0000 | [diff] [blame] | 53 | skb_reset_mac_header(skb); |
| 54 | |
Jan Engelhardt | 713aefa | 2010-03-23 04:07:21 +0100 | [diff] [blame] | 55 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | dev_queue_xmit); |
| 57 | } |
| 58 | |
Stephen Hemminger | 18fdb2b | 2006-03-20 22:58:49 -0800 | [diff] [blame] | 59 | static inline void br_set_ticks(unsigned char *dest, int j) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | { |
Stephen Hemminger | 18fdb2b | 2006-03-20 22:58:49 -0800 | [diff] [blame] | 61 | unsigned long ticks = (STP_HZ * j)/ HZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
Harvey Harrison | d3e2ce3 | 2008-05-02 16:26:16 -0700 | [diff] [blame] | 63 | put_unaligned_be16(ticks, dest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | } |
| 65 | |
Stephen Hemminger | 18fdb2b | 2006-03-20 22:58:49 -0800 | [diff] [blame] | 66 | static inline int br_get_ticks(const unsigned char *src) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | { |
Harvey Harrison | d3e2ce3 | 2008-05-02 16:26:16 -0700 | [diff] [blame] | 68 | unsigned long ticks = get_unaligned_be16(src); |
Stephen Hemminger | 18fdb2b | 2006-03-20 22:58:49 -0800 | [diff] [blame] | 69 | |
Ilpo Järvinen | 172589c | 2007-08-28 15:50:33 -0700 | [diff] [blame] | 70 | return DIV_ROUND_UP(ticks * HZ, STP_HZ); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | } |
| 72 | |
| 73 | /* called under bridge lock */ |
| 74 | void br_send_config_bpdu(struct net_bridge_port *p, struct br_config_bpdu *bpdu) |
| 75 | { |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 76 | unsigned char buf[35]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
Stephen Hemminger | 9cde070 | 2007-03-21 14:22:44 -0700 | [diff] [blame] | 78 | if (p->br->stp_enabled != BR_KERNEL_STP) |
| 79 | return; |
| 80 | |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 81 | buf[0] = 0; |
| 82 | buf[1] = 0; |
| 83 | buf[2] = 0; |
| 84 | buf[3] = BPDU_TYPE_CONFIG; |
| 85 | buf[4] = (bpdu->topology_change ? 0x01 : 0) | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | (bpdu->topology_change_ack ? 0x80 : 0); |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 87 | buf[5] = bpdu->root.prio[0]; |
| 88 | buf[6] = bpdu->root.prio[1]; |
| 89 | buf[7] = bpdu->root.addr[0]; |
| 90 | buf[8] = bpdu->root.addr[1]; |
| 91 | buf[9] = bpdu->root.addr[2]; |
| 92 | buf[10] = bpdu->root.addr[3]; |
| 93 | buf[11] = bpdu->root.addr[4]; |
| 94 | buf[12] = bpdu->root.addr[5]; |
| 95 | buf[13] = (bpdu->root_path_cost >> 24) & 0xFF; |
| 96 | buf[14] = (bpdu->root_path_cost >> 16) & 0xFF; |
| 97 | buf[15] = (bpdu->root_path_cost >> 8) & 0xFF; |
| 98 | buf[16] = bpdu->root_path_cost & 0xFF; |
| 99 | buf[17] = bpdu->bridge_id.prio[0]; |
| 100 | buf[18] = bpdu->bridge_id.prio[1]; |
| 101 | buf[19] = bpdu->bridge_id.addr[0]; |
| 102 | buf[20] = bpdu->bridge_id.addr[1]; |
| 103 | buf[21] = bpdu->bridge_id.addr[2]; |
| 104 | buf[22] = bpdu->bridge_id.addr[3]; |
| 105 | buf[23] = bpdu->bridge_id.addr[4]; |
| 106 | buf[24] = bpdu->bridge_id.addr[5]; |
| 107 | buf[25] = (bpdu->port_id >> 8) & 0xFF; |
| 108 | buf[26] = bpdu->port_id & 0xFF; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 110 | br_set_ticks(buf+27, bpdu->message_age); |
| 111 | br_set_ticks(buf+29, bpdu->max_age); |
| 112 | br_set_ticks(buf+31, bpdu->hello_time); |
| 113 | br_set_ticks(buf+33, bpdu->forward_delay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 115 | br_send_bpdu(p, buf, 35); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | } |
| 117 | |
| 118 | /* called under bridge lock */ |
| 119 | void br_send_tcn_bpdu(struct net_bridge_port *p) |
| 120 | { |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 121 | unsigned char buf[4]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
Stephen Hemminger | 9cde070 | 2007-03-21 14:22:44 -0700 | [diff] [blame] | 123 | if (p->br->stp_enabled != BR_KERNEL_STP) |
| 124 | return; |
| 125 | |
Stephen Hemminger | 12ac84c | 2006-03-20 22:59:49 -0800 | [diff] [blame] | 126 | buf[0] = 0; |
| 127 | buf[1] = 0; |
| 128 | buf[2] = 0; |
| 129 | buf[3] = BPDU_TYPE_TCN; |
Stephen Hemminger | 485c296 | 2006-09-13 20:12:40 -0700 | [diff] [blame] | 130 | br_send_bpdu(p, buf, 4); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | } |
| 132 | |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 133 | /* |
| 134 | * Called from llc. |
| 135 | * |
stephen hemminger | eeaf61d | 2010-07-27 08:26:30 +0000 | [diff] [blame] | 136 | * NO locks, but rcu_read_lock |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 137 | */ |
Patrick McHardy | 7c85fbf | 2008-07-05 21:25:56 -0700 | [diff] [blame] | 138 | void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb, |
| 139 | struct net_device *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | { |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 141 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
Jiri Pirko | f350a0a8 | 2010-06-15 06:50:45 +0000 | [diff] [blame] | 142 | struct net_bridge_port *p; |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 143 | struct net_bridge *br; |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 144 | const unsigned char *buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 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 | |
stephen hemminger | b5ed54e | 2010-11-15 06:38:13 +0000 | [diff] [blame] | 154 | p = br_port_get_rcu(dev); |
| 155 | if (!p) |
| 156 | goto err; |
| 157 | |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 158 | br = p->br; |
| 159 | spin_lock(&br->lock); |
| 160 | |
Stephen Hemminger | 9cde070 | 2007-03-21 14:22:44 -0700 | [diff] [blame] | 161 | if (br->stp_enabled != BR_KERNEL_STP) |
| 162 | goto out; |
| 163 | |
| 164 | if (!(br->dev->flags & IFF_UP)) |
| 165 | goto out; |
| 166 | |
| 167 | if (p->state == BR_STATE_DISABLED) |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 168 | goto out; |
| 169 | |
Stephen Hemminger | fda93d9 | 2006-03-20 22:59:21 -0800 | [diff] [blame] | 170 | if (compare_ether_addr(dest, br->group_addr) != 0) |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 171 | goto out; |
Stephen Hemminger | 85967bb | 2005-05-29 14:15:55 -0700 | [diff] [blame] | 172 | |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 173 | buf = skb_pull(skb, 3); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | if (buf[0] == BPDU_TYPE_CONFIG) { |
| 176 | struct br_config_bpdu bpdu; |
| 177 | |
| 178 | if (!pskb_may_pull(skb, 32)) |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 179 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | |
| 181 | buf = skb->data; |
| 182 | bpdu.topology_change = (buf[1] & 0x01) ? 1 : 0; |
| 183 | bpdu.topology_change_ack = (buf[1] & 0x80) ? 1 : 0; |
| 184 | |
| 185 | bpdu.root.prio[0] = buf[2]; |
| 186 | bpdu.root.prio[1] = buf[3]; |
| 187 | bpdu.root.addr[0] = buf[4]; |
| 188 | bpdu.root.addr[1] = buf[5]; |
| 189 | bpdu.root.addr[2] = buf[6]; |
| 190 | bpdu.root.addr[3] = buf[7]; |
| 191 | bpdu.root.addr[4] = buf[8]; |
| 192 | bpdu.root.addr[5] = buf[9]; |
| 193 | bpdu.root_path_cost = |
| 194 | (buf[10] << 24) | |
| 195 | (buf[11] << 16) | |
| 196 | (buf[12] << 8) | |
| 197 | buf[13]; |
| 198 | bpdu.bridge_id.prio[0] = buf[14]; |
| 199 | bpdu.bridge_id.prio[1] = buf[15]; |
| 200 | bpdu.bridge_id.addr[0] = buf[16]; |
| 201 | bpdu.bridge_id.addr[1] = buf[17]; |
| 202 | bpdu.bridge_id.addr[2] = buf[18]; |
| 203 | bpdu.bridge_id.addr[3] = buf[19]; |
| 204 | bpdu.bridge_id.addr[4] = buf[20]; |
| 205 | bpdu.bridge_id.addr[5] = buf[21]; |
| 206 | bpdu.port_id = (buf[22] << 8) | buf[23]; |
| 207 | |
| 208 | bpdu.message_age = br_get_ticks(buf+24); |
| 209 | bpdu.max_age = br_get_ticks(buf+26); |
| 210 | bpdu.hello_time = br_get_ticks(buf+28); |
| 211 | bpdu.forward_delay = br_get_ticks(buf+30); |
| 212 | |
| 213 | br_received_config_bpdu(p, &bpdu); |
| 214 | } |
| 215 | |
| 216 | else if (buf[0] == BPDU_TYPE_TCN) { |
| 217 | br_received_tcn_bpdu(p); |
| 218 | } |
| 219 | out: |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 220 | spin_unlock(&br->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | err: |
| 222 | kfree_skb(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |