net/netfilter/nf_tproxy_core.c

   1 /*
   2  * Transparent proxy support for Linux/iptables
   3  *
   4  * Copyright (c) 2006-2007 BalaBit IT Ltd.
   5  * Author: Balazs Scheidler, Krisztian Kovacs
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  */
  12
  13 #include <linux/module.h>
  14
  15 #include <linux/net.h>
  16 #include <linux/if.h>
  17 #include <linux/netdevice.h>
  18 #include <net/udp.h>
  19 #include <net/netfilter/nf_tproxy_core.h>
  20
  21
  22 static void
  23 nf_tproxy_destructor(struct sk_buff *skb)
  24 {
  25         struct sock *sk = skb->sk;
  26
  27         skb->sk = NULL;
  28         skb->destructor = NULL;
  29
  30         if (sk)
  31                 nf_tproxy_put_sock(sk);
  32 }
  33
  34 /* consumes sk */
  35 int
  36 nf_tproxy_assign_sock(struct sk_buff *skb, struct sock *sk)
  37 {
  38         bool transparent = (sk->sk_state == TCP_TIME_WAIT) ?
  39                                 inet_twsk(sk)->tw_transparent :
  40                                 inet_sk(sk)->transparent;
  41
  42         if (transparent) {
  43                 skb_orphan(skb);
  44                 skb->sk = sk;
  45                 skb->destructor = nf_tproxy_destructor;
  46                 return 1;
  47         } else
  48                 nf_tproxy_put_sock(sk);
  49
  50         return 0;
  51 }
  52 EXPORT_SYMBOL_GPL(nf_tproxy_assign_sock);
  53
  54 static int __init nf_tproxy_init(void)
  55 {
  56         pr_info("NF_TPROXY: Transparent proxy support initialized, version 4.1.0\n");
  57         pr_info("NF_TPROXY: Copyright (c) 2006-2007 BalaBit IT Ltd.\n");
  58         return 0;
  59 }
  60
  61 module_init(nf_tproxy_init);
  62
  63 MODULE_LICENSE("GPL");
  64 MODULE_AUTHOR("Krisztian Kovacs");
  65 MODULE_DESCRIPTION("Transparent proxy support core routines");