5 * Grzegorz Borowiak <grzes@gnu.univ.gda.pl>
6 * Bart De Schuymer <bdschuym@pandora.be>
12 #include <linux/netfilter_bridge/ebtables.h>
13 #include <linux/netfilter_bridge/ebt_arpreply.h>
14 #include <linux/if_arp.h>
16 #include <linux/module.h>
18 static int ebt_target_reply(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)
22 struct ebt_arpreply_info *info = (struct ebt_arpreply_info *)data;
23 __be32 _sip, *siptr, _dip, *diptr;
24 struct arphdr _ah, *ap;
25 unsigned char _sha[ETH_ALEN], *shp;
27 ap = skb_header_pointer(skb, 0, sizeof(_ah), &_ah);
31 if (ap->ar_op != htons(ARPOP_REQUEST) ||
32 ap->ar_hln != ETH_ALEN ||
33 ap->ar_pro != htons(ETH_P_IP) ||
37 shp = skb_header_pointer(skb, sizeof(_ah), ETH_ALEN, &_sha);
41 siptr = skb_header_pointer(skb, sizeof(_ah) + ETH_ALEN,
46 diptr = skb_header_pointer(skb,
47 sizeof(_ah) + 2 * ETH_ALEN + sizeof(_sip),
52 arp_send(ARPOP_REPLY, ETH_P_ARP, *siptr, (struct net_device *)in,
53 *diptr, shp, info->mac, shp);
58 static int ebt_target_reply_check(const char *tablename, unsigned int hookmask,
59 const struct ebt_entry *e, void *data, unsigned int datalen)
61 struct ebt_arpreply_info *info = (struct ebt_arpreply_info *)data;
63 if (datalen != EBT_ALIGN(sizeof(struct ebt_arpreply_info)))
65 if (BASE_CHAIN && info->target == EBT_RETURN)
67 if (e->ethproto != htons(ETH_P_ARP) ||
68 e->invflags & EBT_IPROTO)
71 if (strcmp(tablename, "nat") || hookmask & ~(1 << NF_BR_PRE_ROUTING))
76 static struct ebt_target reply_target =
78 .name = EBT_ARPREPLY_TARGET,
79 .target = ebt_target_reply,
80 .check = ebt_target_reply_check,
84 static int __init ebt_arpreply_init(void)
86 return ebt_register_target(&reply_target);
89 static void __exit ebt_arpreply_fini(void)
91 ebt_unregister_target(&reply_target);
94 module_init(ebt_arpreply_init);
95 module_exit(ebt_arpreply_fini);
96 MODULE_LICENSE("GPL");