blob: a260679afad8b0beabbff8a21a7e53079f525f8c [file] [log] [blame]
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 *
8 * $Id: br_input.c,v 1.10 2001/12/24 04:50:20 davem Exp $
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16#include <linux/kernel.h>
17#include <linux/netdevice.h>
18#include <linux/etherdevice.h>
19#include <linux/netfilter_bridge.h>
20#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
Linus Torvalds1da177e2005-04-16 15:20:36 -070025static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
26{
27 struct net_device *indev;
28
29 br->statistics.rx_packets++;
30 br->statistics.rx_bytes += skb->len;
31
32 indev = skb->dev;
33 skb->dev = br->dev;
34
35 NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
Stephen Hemmingerd5513a72006-03-20 22:57:18 -080036 netif_receive_skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037}
38
39/* note: already called with rcu_read_lock (preempt_disabled) */
40int br_handle_frame_finish(struct sk_buff *skb)
41{
42 const unsigned char *dest = eth_hdr(skb)->h_dest;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080043 struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
44 struct net_bridge *br;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 struct net_bridge_fdb_entry *dst;
46 int passedup = 0;
47
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080048 if (!p || p->state == BR_STATE_DISABLED)
49 goto drop;
Stephen Hemminger85967bb2005-05-29 14:15:55 -070050
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080051 /* insert into forwarding database after filtering to avoid spoofing */
52 br = p->br;
53 br_fdb_update(br, p, eth_hdr(skb)->h_source);
54
55 if (p->state == BR_STATE_LEARNING)
56 goto drop;
Stephen Hemminger0e5eaba2005-12-21 19:00:18 -080057
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 if (br->dev->flags & IFF_PROMISC) {
59 struct sk_buff *skb2;
60
61 skb2 = skb_clone(skb, GFP_ATOMIC);
62 if (skb2 != NULL) {
63 passedup = 1;
64 br_pass_frame_up(br, skb2);
65 }
66 }
67
Kris Katterjohndbbc0982006-01-06 13:05:58 -080068 if (is_multicast_ether_addr(dest)) {
Stephen Hemminger1c29fc42006-05-05 17:07:13 -070069 br->statistics.multicast++;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 br_flood_forward(br, skb, !passedup);
71 if (!passedup)
72 br_pass_frame_up(br, skb);
73 goto out;
74 }
75
76 dst = __br_fdb_get(br, dest);
77 if (dst != NULL && dst->is_local) {
78 if (!passedup)
79 br_pass_frame_up(br, skb);
80 else
81 kfree_skb(skb);
82 goto out;
83 }
84
85 if (dst != NULL) {
86 br_forward(dst->dst, skb);
87 goto out;
88 }
89
90 br_flood_forward(br, skb, 0);
91
92out:
93 return 0;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080094drop:
95 kfree_skb(skb);
96 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097}
98
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -080099/* note: already called with rcu_read_lock (preempt_disabled) */
100static int br_handle_local_finish(struct sk_buff *skb)
101{
102 struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
103
104 if (p && p->state != BR_STATE_DISABLED)
105 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
106
107 return 0; /* process further */
108}
109
110/* Does address match the link local multicast address.
111 * 01:80:c2:00:00:0X
112 */
Andrew Mortonb3e83d62006-03-20 23:00:56 -0800113static inline int is_link_local(const unsigned char *dest)
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800114{
Stephen Hemmingerfd74e6c2007-03-12 16:25:32 -0700115 const u16 *a = (const u16 *) dest;
116 static const u16 *const b = (const u16 *const ) br_group_address;
117 static const u16 m = __constant_cpu_to_be16(0xfff0);
118
119 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800120}
121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122/*
123 * Called via br_handle_frame_hook.
124 * Return 0 if *pskb should be processed furthur
125 * 1 if *pskb is handled
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900126 * note: already called with rcu_read_lock (preempt_disabled)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 */
128int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
129{
130 struct sk_buff *skb = *pskb;
131 const unsigned char *dest = eth_hdr(skb)->h_dest;
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
134 goto err;
135
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800136 if (unlikely(is_link_local(dest))) {
137 skb->pkt_type = PACKET_HOST;
138 return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
139 NULL, br_handle_local_finish) != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 }
141
Stephen Hemminger0e5eaba2005-12-21 19:00:18 -0800142 if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 if (br_should_route_hook) {
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +0900144 if (br_should_route_hook(pskb))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 return 0;
146 skb = *pskb;
147 dest = eth_hdr(skb)->h_dest;
148 }
149
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700150 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 skb->pkt_type = PACKET_HOST;
152
153 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
154 br_handle_frame_finish);
155 return 1;
156 }
157
158err:
159 kfree_skb(skb);
160 return 1;
161}