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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Handle incoming frames
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
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/netdevice.h>
17#include <linux/etherdevice.h>
18#include <linux/netfilter_bridge.h>
Paul Gortmakerbc3b2d72011-07-15 11:47:34 -040019#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include "br_private.h"
21
Stephen Hemmingerfda93d92006-03-20 22:59:21 -080022/* Bridge group multicast address 802.1d (pg 51). */
23const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Eric Dumazeta386f992010-11-15 06:38:11 +000025/* Hook for brouter */
26br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
27EXPORT_SYMBOL(br_should_route_hook);
28
Herbert Xu68b7c892010-02-27 19:41:40 +000029static int br_pass_frame_up(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030{
Herbert Xu68b7c892010-02-27 19:41:40 +000031 struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
stephen hemminger14bb4782010-03-02 13:32:09 +000032 struct net_bridge *br = netdev_priv(brdev);
33 struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Eric Dumazet406818f2010-06-23 13:00:48 -070035 u64_stats_update_begin(&brstats->syncp);
stephen hemminger14bb4782010-03-02 13:32:09 +000036 brstats->rx_packets++;
37 brstats->rx_bytes += skb->len;
Eric Dumazet406818f2010-06-23 13:00:48 -070038 u64_stats_update_end(&brstats->syncp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40 indev = skb->dev;
Pavel Emelyanova339f1c2008-05-21 14:13:47 -070041 skb->dev = brdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Jan Engelhardt713aefa2010-03-23 04:07:21 +010043 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
Herbert Xu68b7c892010-02-27 19:41:40 +000044 netif_receive_skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070045}
46
stephen hemmingereeaf61d2010-07-27 08:26:30 +000047/* note: already called with rcu_read_lock */
Linus Torvalds1da177e2005-04-16 15:20:36 -070048int br_handle_frame_finish(struct sk_buff *skb)
49{
50 const unsigned char *dest = eth_hdr(skb)->h_dest;
Jiri Pirkof350a0a2010-06-15 06:50:45 +000051 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080052 struct net_bridge *br;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 struct net_bridge_fdb_entry *dst;
Herbert Xuc4fcb782010-02-27 19:41:48 +000054 struct net_bridge_mdb_entry *mdst;
Herbert Xue081e1e2007-09-16 16:20:48 -070055 struct sk_buff *skb2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080057 if (!p || p->state == BR_STATE_DISABLED)
58 goto drop;
Stephen Hemminger85967bb2005-05-29 14:15:55 -070059
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080060 /* insert into forwarding database after filtering to avoid spoofing */
61 br = p->br;
62 br_fdb_update(br, p, eth_hdr(skb)->h_source);
63
Herbert Xu44661462011-07-05 13:58:33 +000064 if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) &&
Herbert Xuc4fcb782010-02-27 19:41:48 +000065 br_multicast_rcv(br, p, skb))
66 goto drop;
67
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080068 if (p->state == BR_STATE_LEARNING)
69 goto drop;
Stephen Hemminger0e5eaba2005-12-21 19:00:18 -080070
Herbert Xu68b7c892010-02-27 19:41:40 +000071 BR_INPUT_SKB_CB(skb)->brdev = br->dev;
72
Herbert Xue081e1e2007-09-16 16:20:48 -070073 /* The packet skb2 goes to the local host (NULL to skip). */
74 skb2 = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
Herbert Xue081e1e2007-09-16 16:20:48 -070076 if (br->dev->flags & IFF_PROMISC)
77 skb2 = skb;
78
79 dst = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Herbert Xu44661462011-07-05 13:58:33 +000081 if (is_broadcast_ether_addr(dest))
82 skb2 = skb;
83 else if (is_multicast_ether_addr(dest)) {
Herbert Xuc4fcb782010-02-27 19:41:48 +000084 mdst = br_mdb_get(br, skb);
YOSHIFUJI Hideaki / 吉藤英明32dec5d2010-03-15 21:51:18 +000085 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) {
Herbert Xu8a870172011-02-12 01:05:42 -080086 if ((mdst && mdst->mglist) ||
Herbert Xuc4fcb782010-02-27 19:41:48 +000087 br_multicast_is_router(br))
88 skb2 = skb;
89 br_multicast_forward(mdst, skb, skb2);
90 skb = NULL;
91 if (!skb2)
92 goto out;
93 } else
94 skb2 = skb;
95
Pavel Emelyanova339f1c2008-05-21 14:13:47 -070096 br->dev->stats.multicast++;
Herbert Xue081e1e2007-09-16 16:20:48 -070097 } else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) {
98 skb2 = skb;
99 /* Do not forward the packet since it's local. */
100 skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 }
102
Herbert Xue081e1e2007-09-16 16:20:48 -0700103 if (skb) {
stephen hemminger7cd88612011-04-04 14:03:28 +0000104 if (dst) {
105 dst->used = jiffies;
Michael Braun7f7708f2010-03-16 00:26:22 -0700106 br_forward(dst->dst, skb, skb2);
stephen hemminger7cd88612011-04-04 14:03:28 +0000107 } else
Herbert Xub33084b2010-02-27 19:41:41 +0000108 br_flood_forward(br, skb, skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 }
110
Herbert Xu87557c12010-02-27 19:41:39 +0000111 if (skb2)
Herbert Xu68b7c892010-02-27 19:41:40 +0000112 return br_pass_frame_up(skb2);
Herbert Xu87557c12010-02-27 19:41:39 +0000113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114out:
115 return 0;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800116drop:
117 kfree_skb(skb);
118 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119}
120
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000121/* note: already called with rcu_read_lock */
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800122static int br_handle_local_finish(struct sk_buff *skb)
123{
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000124 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800125
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000126 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800127 return 0; /* process further */
128}
129
130/* Does address match the link local multicast address.
131 * 01:80:c2:00:00:0X
132 */
Andrew Mortonb3e83d62006-03-20 23:00:56 -0800133static inline int is_link_local(const unsigned char *dest)
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800134{
Al Viro582ee432007-07-26 17:33:39 +0100135 __be16 *a = (__be16 *)dest;
136 static const __be16 *b = (const __be16 *)br_group_address;
YOSHIFUJI Hideaki91c5ec32007-12-12 03:51:03 +0900137 static const __be16 m = cpu_to_be16(0xfff0);
Stephen Hemmingerfd74e6c2007-03-12 16:25:32 -0700138
139 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800140}
141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142/*
Stephen Hemminger6229e362007-03-21 13:38:47 -0700143 * Return NULL if skb is handled
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000144 * note: already called with rcu_read_lock
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 */
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000146rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147{
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000148 struct net_bridge_port *p;
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000149 struct sk_buff *skb = *pskb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 const unsigned char *dest = eth_hdr(skb)->h_dest;
Eric Dumazeta386f992010-11-15 06:38:11 +0000151 br_should_route_hook_t *rhook;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Simon Hormanc2368e72010-08-22 17:35:32 +0000153 if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000154 return RX_HANDLER_PASS;
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
Stephen Hemminger467aea02007-03-21 13:42:06 -0700157 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Herbert Xu7b995652007-10-14 00:39:01 -0700159 skb = skb_share_check(skb, GFP_ATOMIC);
160 if (!skb)
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000161 return RX_HANDLER_CONSUMED;
Herbert Xu7b995652007-10-14 00:39:01 -0700162
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000163 p = br_port_get_rcu(skb->dev);
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000164
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700165 if (unlikely(is_link_local(dest))) {
stephen hemminger515853c2011-10-03 18:14:46 +0000166 /*
167 * See IEEE 802.1D Table 7-10 Reserved addresses
168 *
169 * Assignment Value
170 * Bridge Group Address 01-80-C2-00-00-00
171 * (MAC Control) 802.3 01-80-C2-00-00-01
172 * (Link Aggregation) 802.3 01-80-C2-00-00-02
173 * 802.1X PAE address 01-80-C2-00-00-03
174 *
175 * 802.1AB LLDP 01-80-C2-00-00-0E
176 *
177 * Others reserved for future standardization
178 */
179 switch (dest[5]) {
180 case 0x00: /* Bridge Group Address */
181 /* If STP is turned off,
182 then must forward to keep loop detection */
183 if (p->br->stp_enabled == BR_NO_STP)
184 goto forward;
185 break;
186
187 case 0x01: /* IEEE MAC (Pause) */
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700188 goto drop;
189
stephen hemminger515853c2011-10-03 18:14:46 +0000190 default:
191 /* Allow selective forwarding for most other protocols */
192 if (p->br->group_fwd_mask & (1u << dest[5]))
193 goto forward;
194 }
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000195
stephen hemminger515853c2011-10-03 18:14:46 +0000196 /* Deliver packet to local host only */
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100197 if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000198 NULL, br_handle_local_finish)) {
199 return RX_HANDLER_CONSUMED; /* consumed by filter */
200 } else {
201 *pskb = skb;
202 return RX_HANDLER_PASS; /* continue processing */
203 }
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700204 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000206forward:
Stephen Hemminger467aea02007-03-21 13:42:06 -0700207 switch (p->state) {
208 case BR_STATE_FORWARDING:
Pavel Emelyanov82de3822007-11-29 23:58:58 +1100209 rhook = rcu_dereference(br_should_route_hook);
Eric Dumazeta386f992010-11-15 06:38:11 +0000210 if (rhook) {
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000211 if ((*rhook)(skb)) {
212 *pskb = skb;
213 return RX_HANDLER_PASS;
214 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 dest = eth_hdr(skb)->h_dest;
216 }
Stephen Hemminger467aea02007-03-21 13:42:06 -0700217 /* fall through */
218 case BR_STATE_LEARNING:
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700219 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 skb->pkt_type = PACKET_HOST;
221
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100222 NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 br_handle_frame_finish);
Stephen Hemminger467aea02007-03-21 13:42:06 -0700224 break;
225 default:
226drop:
227 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 }
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000229 return RX_HANDLER_CONSUMED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230}