From 31cdf1b65f5f38bf7bfe3d618b5a5e1a35ff7ea2 Mon Sep 17 00:00:00 2001 From: Bart De Schuymer Date: Thu, 14 Aug 2003 19:55:22 +0000 Subject: by Grzegorz Borowiak --- .../include/linux/netfilter_bridge/ebt_arpreply.h | 11 +++ kernel/linux/net/bridge/netfilter/ebt_arpreply.c | 83 ++++++++++++++++++++++ 2 files changed, 94 insertions(+) create mode 100644 kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h create mode 100644 kernel/linux/net/bridge/netfilter/ebt_arpreply.c diff --git a/kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h b/kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h new file mode 100644 index 0000000..96a8339 --- /dev/null +++ b/kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h @@ -0,0 +1,11 @@ +#ifndef __LINUX_BRIDGE_EBT_ARPREPLY_H +#define __LINUX_BRIDGE_EBT_ARPREPLY_H + +struct ebt_arpreply_info +{ + unsigned char mac[ETH_ALEN]; + int target; +}; +#define EBT_ARPREPLY_TARGET "arpreply" + +#endif diff --git a/kernel/linux/net/bridge/netfilter/ebt_arpreply.c b/kernel/linux/net/bridge/netfilter/ebt_arpreply.c new file mode 100644 index 0000000..91bb1ca --- /dev/null +++ b/kernel/linux/net/bridge/netfilter/ebt_arpreply.c @@ -0,0 +1,83 @@ +/* + * ebt_reply + * + * Authors: + * Grzegorz Borowiak + * + * August, 2003 + * + */ + +#include +#include +#include +#include + +static int ebt_target_reply(struct sk_buff **pskb, unsigned int hooknr, + const struct net_device *in, const struct net_device *out, + const void *data, unsigned int datalen) +{ + struct ebt_arpreply_info *info = (struct ebt_arpreply_info *)data; + struct arphdr *ah; + unsigned char *sha, *arp_ptr; + u32 sip, tip; + + ah = (**pskb).nh.arph; + if (ah->ar_op != __constant_htons(ARPOP_REQUEST) || + ah->ar_hln != ETH_ALEN || ah->ar_pro != htons(ETH_P_IP) || + ah->ar_pln != 4) + return EBT_CONTINUE; + + arp_ptr = (unsigned char *)(ah + 1); + + /* get source and target IP */ + sha = arp_ptr; + arp_ptr += ETH_ALEN; + memcpy(&sip, arp_ptr, 4); + arp_ptr += 4 + ETH_ALEN; + memcpy(&tip, arp_ptr, 4); + + arp_send(ARPOP_REPLY, ETH_P_ARP, sip, in, tip, sha, info->mac, sha); + + return info->target; +} + +static int ebt_target_reply_check(const char *tablename, unsigned int hookmask, + const struct ebt_entry *e, void *data, unsigned int datalen) +{ + struct ebt_arpreply_info *info = (struct ebt_arpreply_info *)data; + + if (datalen != EBT_ALIGN(sizeof(struct ebt_arpreply_info))) + return -EINVAL; + if (BASE_CHAIN && info->target == EBT_RETURN) + return -EINVAL; + if (e->ethproto != __constant_htons(ETH_P_ARP) || + e->invflags & EBT_IPROTO) + return -EINVAL; + CLEAR_BASE_CHAIN_BIT; + if (strcmp(tablename, "nat") || hookmask & ~(1 << NF_BR_PRE_ROUTING)) + return -EINVAL; + return 0; +} + +static struct ebt_target reply_target = +{ + .name = EBT_ARPREPLY_TARGET, + .target = ebt_target_reply, + .check = ebt_target_reply_check, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + return ebt_register_target(&reply_target); +} + +static void __exit fini(void) +{ + ebt_unregister_target(&reply_target); +} + +module_init(init); +module_exit(fini); +MODULE_LICENSE("GPL"); -- cgit v1.2.3