b8afe850cf1ec1ec77dc4773e173ea96608870dc
[linux-2.6.git] / net / bridge / netfilter / ebt_redirect.c
1 /*
2  *  ebt_redirect
3  *
4  *      Authors:
5  *      Bart De Schuymer <bdschuym@pandora.be>
6  *
7  *  April, 2002
8  *
9  */
10
11 #include <linux/netfilter.h>
12 #include <linux/netfilter_bridge/ebtables.h>
13 #include <linux/netfilter_bridge/ebt_redirect.h>
14 #include <linux/module.h>
15 #include <net/sock.h>
16 #include "../br_private.h"
17
18 static int ebt_target_redirect(struct sk_buff *skb, unsigned int hooknr,
19    const struct net_device *in, const struct net_device *out,
20    const void *data, unsigned int datalen)
21 {
22         const struct ebt_redirect_info *info = data;
23
24         if (!skb_make_writable(skb, 0))
25                 return EBT_DROP;
26
27         if (hooknr != NF_BR_BROUTING)
28                 memcpy(eth_hdr(skb)->h_dest,
29                        in->br_port->br->dev->dev_addr, ETH_ALEN);
30         else
31                 memcpy(eth_hdr(skb)->h_dest, in->dev_addr, ETH_ALEN);
32         skb->pkt_type = PACKET_HOST;
33         return info->target;
34 }
35
36 static int ebt_target_redirect_check(const char *tablename, unsigned int hookmask,
37    const struct ebt_entry *e, void *data, unsigned int datalen)
38 {
39         const struct ebt_redirect_info *info = data;
40
41         if (datalen != EBT_ALIGN(sizeof(struct ebt_redirect_info)))
42                 return -EINVAL;
43         if (BASE_CHAIN && info->target == EBT_RETURN)
44                 return -EINVAL;
45         CLEAR_BASE_CHAIN_BIT;
46         if ( (strcmp(tablename, "nat") || hookmask & ~(1 << NF_BR_PRE_ROUTING)) &&
47              (strcmp(tablename, "broute") || hookmask & ~(1 << NF_BR_BROUTING)) )
48                 return -EINVAL;
49         if (INVALID_TARGET)
50                 return -EINVAL;
51         return 0;
52 }
53
54 static struct ebt_target redirect_target __read_mostly = {
55         .name           = EBT_REDIRECT_TARGET,
56         .target         = ebt_target_redirect,
57         .check          = ebt_target_redirect_check,
58         .me             = THIS_MODULE,
59 };
60
61 static int __init ebt_redirect_init(void)
62 {
63         return ebt_register_target(&redirect_target);
64 }
65
66 static void __exit ebt_redirect_fini(void)
67 {
68         ebt_unregister_target(&redirect_target);
69 }
70
71 module_init(ebt_redirect_init);
72 module_exit(ebt_redirect_fini);
73 MODULE_DESCRIPTION("Ebtables: Packet redirection to localhost");
74 MODULE_LICENSE("GPL");