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/*
* Transparent proxy support for Linux/iptables
*
* Copyright (c) 2006-2007 BalaBit IT Ltd.
* Author: Balazs Scheidler, Krisztian Kovacs
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/net.h>
#include <linux/if.h>
#include <linux/netdevice.h>
#include <net/udp.h>
#include <net/netfilter/nf_tproxy_core.h>
struct sock *
nf_tproxy_get_sock_v4(struct net *net, const u8 protocol,
const __be32 saddr, const __be32 daddr,
const __be16 sport, const __be16 dport,
const struct net_device *in, bool listening_only)
{
struct sock *sk;
/* look up socket */
switch (protocol) {
case IPPROTO_TCP:
if (listening_only)
sk = __inet_lookup_listener(net, &tcp_hashinfo,
daddr, ntohs(dport),
in->ifindex);
else
sk = __inet_lookup(net, &tcp_hashinfo,
saddr, sport, daddr, dport,
in->ifindex);
break;
case IPPROTO_UDP:
sk = udp4_lib_lookup(net, saddr, sport, daddr, dport,
in->ifindex);
break;
default:
WARN_ON(1);
sk = NULL;
}
pr_debug("tproxy socket lookup: proto %u %08x:%u -> %08x:%u, listener only: %d, sock %p\n",
protocol, ntohl(saddr), ntohs(sport), ntohl(daddr), ntohs(dport), listening_only, sk);
return sk;
}
EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v4);
static void
nf_tproxy_destructor(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
skb->sk = NULL;
skb->destructor = NULL;
if (sk)
nf_tproxy_put_sock(sk);
}
/* consumes sk */
int
nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
{
bool transparent = (sk->sk_state == TCP_TIME_WAIT) ?
inet_twsk(sk)->tw_transparent :
inet_sk(sk)->transparent;
if (transparent) {
skb_orphan(skb);
skb->sk = sk;
skb->destructor = nf_tproxy_destructor;
return 1;
} else
nf_tproxy_put_sock(sk);
return 0;
}
EXPORT_SYMBOL_GPL(nf_tproxy_assign_sock);
static int __init nf_tproxy_init(void)
{
pr_info("NF_TPROXY: Transparent proxy support initialized, version 4.1.0\n");
pr_info("NF_TPROXY: Copyright (c) 2006-2007 BalaBit IT Ltd.\n");
return 0;
}
module_init(nf_tproxy_init);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Krisztian Kovacs");
MODULE_DESCRIPTION("Transparent proxy support core routines");
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