Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy...
[linux-2.6] / net / bridge / br_input.c
1 /*
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
22 const unsigned char bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
23
24 static int br_pass_frame_up_finish(struct sk_buff *skb)
25 {
26         netif_receive_skb(skb);
27         return 0;
28 }
29
30 static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
31 {
32         struct net_device *indev;
33
34         br->statistics.rx_packets++;
35         br->statistics.rx_bytes += skb->len;
36
37         indev = skb->dev;
38         skb->dev = br->dev;
39
40         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
41                         br_pass_frame_up_finish);
42 }
43
44 /* note: already called with rcu_read_lock (preempt_disabled) */
45 int br_handle_frame_finish(struct sk_buff *skb)
46 {
47         const unsigned char *dest = eth_hdr(skb)->h_dest;
48         struct net_bridge_port *p = skb->dev->br_port;
49         struct net_bridge *br = p->br;
50         struct net_bridge_fdb_entry *dst;
51         int passedup = 0;
52
53         /* insert into forwarding database after filtering to avoid spoofing */
54         br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
55
56         if (br->dev->flags & IFF_PROMISC) {
57                 struct sk_buff *skb2;
58
59                 skb2 = skb_clone(skb, GFP_ATOMIC);
60                 if (skb2 != NULL) {
61                         passedup = 1;
62                         br_pass_frame_up(br, skb2);
63                 }
64         }
65
66         if (dest[0] & 1) {
67                 br_flood_forward(br, skb, !passedup);
68                 if (!passedup)
69                         br_pass_frame_up(br, skb);
70                 goto out;
71         }
72
73         dst = __br_fdb_get(br, dest);
74         if (dst != NULL && dst->is_local) {
75                 if (!passedup)
76                         br_pass_frame_up(br, skb);
77                 else
78                         kfree_skb(skb);
79                 goto out;
80         }
81
82         if (dst != NULL) {
83                 br_forward(dst->dst, skb);
84                 goto out;
85         }
86
87         br_flood_forward(br, skb, 0);
88
89 out:
90         return 0;
91 }
92
93 /*
94  * Called via br_handle_frame_hook.
95  * Return 0 if *pskb should be processed furthur
96  *        1 if *pskb is handled
97  * note: already called with rcu_read_lock (preempt_disabled) 
98  */
99 int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
100 {
101         struct sk_buff *skb = *pskb;
102         const unsigned char *dest = eth_hdr(skb)->h_dest;
103
104         if (p->state == BR_STATE_DISABLED)
105                 goto err;
106
107         if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
108                 goto err;
109
110         if (p->state == BR_STATE_LEARNING)
111                 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
112
113         if (p->br->stp_enabled &&
114             !memcmp(dest, bridge_ula, 5) &&
115             !(dest[5] & 0xF0)) {
116                 if (!dest[5]) {
117                         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, 
118                                 NULL, br_stp_handle_bpdu);
119                         return 1;
120                 }
121         }
122
123         else if (p->state == BR_STATE_FORWARDING) {
124                 if (br_should_route_hook) {
125                         if (br_should_route_hook(pskb)) 
126                                 return 0;
127                         skb = *pskb;
128                         dest = eth_hdr(skb)->h_dest;
129                 }
130
131                 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
132                         skb->pkt_type = PACKET_HOST;
133
134                 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
135                         br_handle_frame_finish);
136                 return 1;
137         }
138
139 err:
140         kfree_skb(skb);
141         return 1;
142 }