Merge with http://kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
[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 (p->state == BR_STATE_LEARNING) {
57                 kfree_skb(skb);
58                 goto out;
59         }
60
61         if (br->dev->flags & IFF_PROMISC) {
62                 struct sk_buff *skb2;
63
64                 skb2 = skb_clone(skb, GFP_ATOMIC);
65                 if (skb2 != NULL) {
66                         passedup = 1;
67                         br_pass_frame_up(br, skb2);
68                 }
69         }
70
71         if (dest[0] & 1) {
72                 br_flood_forward(br, skb, !passedup);
73                 if (!passedup)
74                         br_pass_frame_up(br, skb);
75                 goto out;
76         }
77
78         dst = __br_fdb_get(br, dest);
79         if (dst != NULL && dst->is_local) {
80                 if (!passedup)
81                         br_pass_frame_up(br, skb);
82                 else
83                         kfree_skb(skb);
84                 goto out;
85         }
86
87         if (dst != NULL) {
88                 br_forward(dst->dst, skb);
89                 goto out;
90         }
91
92         br_flood_forward(br, skb, 0);
93
94 out:
95         return 0;
96 }
97
98 /*
99  * Called via br_handle_frame_hook.
100  * Return 0 if *pskb should be processed furthur
101  *        1 if *pskb is handled
102  * note: already called with rcu_read_lock (preempt_disabled) 
103  */
104 int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
105 {
106         struct sk_buff *skb = *pskb;
107         const unsigned char *dest = eth_hdr(skb)->h_dest;
108
109         if (p->state == BR_STATE_DISABLED)
110                 goto err;
111
112         if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
113                 goto err;
114
115         if (p->br->stp_enabled &&
116             !memcmp(dest, bridge_ula, 5) &&
117             !(dest[5] & 0xF0)) {
118                 if (!dest[5]) {
119                         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, 
120                                 NULL, br_stp_handle_bpdu);
121                         return 1;
122                 }
123                 goto err;
124         }
125
126         if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
127                 if (br_should_route_hook) {
128                         if (br_should_route_hook(pskb)) 
129                                 return 0;
130                         skb = *pskb;
131                         dest = eth_hdr(skb)->h_dest;
132                 }
133
134                 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
135                         skb->pkt_type = PACKET_HOST;
136
137                 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
138                         br_handle_frame_finish);
139                 return 1;
140         }
141
142 err:
143         kfree_skb(skb);
144         return 1;
145 }