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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>
19#include "br_private.h"
20
Stephen Hemmingerfda93d92006-03-20 22:59:21 -080021/* Bridge group multicast address 802.1d (pg 51). */
22const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
Eric Dumazeta386f992010-11-15 06:38:11 +000024/* Hook for brouter */
25br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
26EXPORT_SYMBOL(br_should_route_hook);
27
Herbert Xu68b7c892010-02-27 19:41:40 +000028static int br_pass_frame_up(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029{
Herbert Xu68b7c892010-02-27 19:41:40 +000030 struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
stephen hemminger14bb4782010-03-02 13:32:09 +000031 struct net_bridge *br = netdev_priv(brdev);
32 struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Eric Dumazet406818f2010-06-23 13:00:48 -070034 u64_stats_update_begin(&brstats->syncp);
stephen hemminger14bb4782010-03-02 13:32:09 +000035 brstats->rx_packets++;
36 brstats->rx_bytes += skb->len;
Eric Dumazet406818f2010-06-23 13:00:48 -070037 u64_stats_update_end(&brstats->syncp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39 indev = skb->dev;
Pavel Emelyanova339f1c2008-05-21 14:13:47 -070040 skb->dev = brdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Jan Engelhardt713aefa2010-03-23 04:07:21 +010042 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
Herbert Xu68b7c892010-02-27 19:41:40 +000043 netif_receive_skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044}
45
stephen hemmingereeaf61d2010-07-27 08:26:30 +000046/* note: already called with rcu_read_lock */
Linus Torvalds1da177e2005-04-16 15:20:36 -070047int br_handle_frame_finish(struct sk_buff *skb)
48{
49 const unsigned char *dest = eth_hdr(skb)->h_dest;
Jiri Pirkof350a0a2010-06-15 06:50:45 +000050 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080051 struct net_bridge *br;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 struct net_bridge_fdb_entry *dst;
Herbert Xuc4fcb782010-02-27 19:41:48 +000053 struct net_bridge_mdb_entry *mdst;
Herbert Xue081e1e2007-09-16 16:20:48 -070054 struct sk_buff *skb2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080056 if (!p || p->state == BR_STATE_DISABLED)
57 goto drop;
Stephen Hemminger85967bb2005-05-29 14:15:55 -070058
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080059 /* insert into forwarding database after filtering to avoid spoofing */
60 br = p->br;
61 br_fdb_update(br, p, eth_hdr(skb)->h_source);
62
Herbert Xu44661462011-07-05 13:58:33 +000063 if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) &&
Herbert Xuc4fcb782010-02-27 19:41:48 +000064 br_multicast_rcv(br, p, skb))
65 goto drop;
66
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080067 if (p->state == BR_STATE_LEARNING)
68 goto drop;
Stephen Hemminger0e5eaba2005-12-21 19:00:18 -080069
Herbert Xu68b7c892010-02-27 19:41:40 +000070 BR_INPUT_SKB_CB(skb)->brdev = br->dev;
71
Herbert Xue081e1e2007-09-16 16:20:48 -070072 /* The packet skb2 goes to the local host (NULL to skip). */
73 skb2 = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Herbert Xue081e1e2007-09-16 16:20:48 -070075 if (br->dev->flags & IFF_PROMISC)
76 skb2 = skb;
77
78 dst = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Herbert Xu44661462011-07-05 13:58:33 +000080 if (is_broadcast_ether_addr(dest))
81 skb2 = skb;
82 else if (is_multicast_ether_addr(dest)) {
Herbert Xuc4fcb782010-02-27 19:41:48 +000083 mdst = br_mdb_get(br, skb);
YOSHIFUJI Hideaki / 吉藤英明32dec5d2010-03-15 21:51:18 +000084 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) {
Herbert Xu8a870172011-02-12 01:05:42 -080085 if ((mdst && mdst->mglist) ||
Herbert Xuc4fcb782010-02-27 19:41:48 +000086 br_multicast_is_router(br))
87 skb2 = skb;
88 br_multicast_forward(mdst, skb, skb2);
89 skb = NULL;
90 if (!skb2)
91 goto out;
92 } else
93 skb2 = skb;
94
Pavel Emelyanova339f1c2008-05-21 14:13:47 -070095 br->dev->stats.multicast++;
Herbert Xue081e1e2007-09-16 16:20:48 -070096 } else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) {
97 skb2 = skb;
98 /* Do not forward the packet since it's local. */
99 skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 }
101
Herbert Xue081e1e2007-09-16 16:20:48 -0700102 if (skb) {
stephen hemminger7cd88612011-04-04 14:03:28 +0000103 if (dst) {
104 dst->used = jiffies;
Michael Braun7f7708f2010-03-16 00:26:22 -0700105 br_forward(dst->dst, skb, skb2);
stephen hemminger7cd88612011-04-04 14:03:28 +0000106 } else
Herbert Xub33084b2010-02-27 19:41:41 +0000107 br_flood_forward(br, skb, skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 }
109
Herbert Xu87557c12010-02-27 19:41:39 +0000110 if (skb2)
Herbert Xu68b7c892010-02-27 19:41:40 +0000111 return br_pass_frame_up(skb2);
Herbert Xu87557c12010-02-27 19:41:39 +0000112
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113out:
114 return 0;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800115drop:
116 kfree_skb(skb);
117 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118}
119
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000120/* note: already called with rcu_read_lock */
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800121static int br_handle_local_finish(struct sk_buff *skb)
122{
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000123 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800124
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000125 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800126 return 0; /* process further */
127}
128
129/* Does address match the link local multicast address.
130 * 01:80:c2:00:00:0X
131 */
Andrew Mortonb3e83d62006-03-20 23:00:56 -0800132static inline int is_link_local(const unsigned char *dest)
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800133{
Al Viro582ee432007-07-26 17:33:39 +0100134 __be16 *a = (__be16 *)dest;
135 static const __be16 *b = (const __be16 *)br_group_address;
YOSHIFUJI Hideaki91c5ec32007-12-12 03:51:03 +0900136 static const __be16 m = cpu_to_be16(0xfff0);
Stephen Hemmingerfd74e6c2007-03-12 16:25:32 -0700137
138 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800139}
140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141/*
Stephen Hemminger6229e362007-03-21 13:38:47 -0700142 * Return NULL if skb is handled
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000143 * note: already called with rcu_read_lock
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 */
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000145rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146{
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000147 struct net_bridge_port *p;
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000148 struct sk_buff *skb = *pskb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 const unsigned char *dest = eth_hdr(skb)->h_dest;
Eric Dumazeta386f992010-11-15 06:38:11 +0000150 br_should_route_hook_t *rhook;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
Simon Hormanc2368e72010-08-22 17:35:32 +0000152 if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000153 return RX_HANDLER_PASS;
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
Stephen Hemminger467aea02007-03-21 13:42:06 -0700156 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Herbert Xu7b995652007-10-14 00:39:01 -0700158 skb = skb_share_check(skb, GFP_ATOMIC);
159 if (!skb)
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000160 return RX_HANDLER_CONSUMED;
Herbert Xu7b995652007-10-14 00:39:01 -0700161
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000162 p = br_port_get_rcu(skb->dev);
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000163
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700164 if (unlikely(is_link_local(dest))) {
165 /* Pause frames shouldn't be passed up by driver anyway */
166 if (skb->protocol == htons(ETH_P_PAUSE))
167 goto drop;
168
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000169 /* If STP is turned off, then forward */
David S. Millerf01cb5f2011-04-21 21:17:25 -0700170 if (p->br->stp_enabled == BR_NO_STP && dest[5] == 0)
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000171 goto forward;
172
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100173 if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000174 NULL, br_handle_local_finish)) {
175 return RX_HANDLER_CONSUMED; /* consumed by filter */
176 } else {
177 *pskb = skb;
178 return RX_HANDLER_PASS; /* continue processing */
179 }
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700180 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000182forward:
Stephen Hemminger467aea02007-03-21 13:42:06 -0700183 switch (p->state) {
184 case BR_STATE_FORWARDING:
Pavel Emelyanov82de3822007-11-29 23:58:58 +1100185 rhook = rcu_dereference(br_should_route_hook);
Eric Dumazeta386f992010-11-15 06:38:11 +0000186 if (rhook) {
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000187 if ((*rhook)(skb)) {
188 *pskb = skb;
189 return RX_HANDLER_PASS;
190 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 dest = eth_hdr(skb)->h_dest;
192 }
Stephen Hemminger467aea02007-03-21 13:42:06 -0700193 /* fall through */
194 case BR_STATE_LEARNING:
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700195 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 skb->pkt_type = PACKET_HOST;
197
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100198 NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 br_handle_frame_finish);
Stephen Hemminger467aea02007-03-21 13:42:06 -0700200 break;
201 default:
202drop:
203 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 }
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000205 return RX_HANDLER_CONSUMED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206}