The TPROXY target implements redirection of non-local TCP/UDP traffic
to local sockets. It is simply a wrapper around functionality exported
from iptable_tproxy.

Signed-off-by: KOVACS Krisztian <[EMAIL PROTECTED]>

---

 include/linux/netfilter_ipv4/ipt_TPROXY.h |    9 +++
 net/ipv4/netfilter/Kconfig                |   11 +++
 net/ipv4/netfilter/Makefile               |    1 
 net/ipv4/netfilter/ipt_TPROXY.c           |  103 +++++++++++++++++++++++++++++
 4 files changed, 124 insertions(+), 0 deletions(-)

diff --git a/include/linux/netfilter_ipv4/ipt_TPROXY.h 
b/include/linux/netfilter_ipv4/ipt_TPROXY.h
new file mode 100644
index 0000000..d05c956
--- /dev/null
+++ b/include/linux/netfilter_ipv4/ipt_TPROXY.h
@@ -0,0 +1,9 @@
+#ifndef _IPT_TPROXY_H_target
+#define _IPT_TPROXY_H_target
+
+struct ipt_tproxy_target_info {
+       u_int16_t lport;
+       u_int32_t laddr;
+};
+
+#endif
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 312b0ef..7f76ab6 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -662,6 +662,17 @@ config IP_NF_TPROXY
 
          To compile it as a module, choose M here.  If unsure, say N.
 
+config IP_NF_TARGET_TPROXY
+       tristate "TPROXY target support"
+       depends on IP_NF_TPROXY
+       help
+         This option adds a `TPROXY' target, which is somewhat similar to
+         REDIRECT.  It can only be used in the tproxy table and is useful
+         to redirect traffic to a transparent proxy.  It does _not_ depend
+         on Netfilter connection tracking.
+
+         To compile it as a module, choose M here.  If unsure, say N.
+
 # ARP tables
 config IP_NF_ARPTABLES
        tristate "ARP tables support"
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index aa57ce4..851da93 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -97,6 +97,7 @@ obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_U
 obj-$(CONFIG_IP_NF_TARGET_TCPMSS) += ipt_TCPMSS.o
 obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
 obj-$(CONFIG_IP_NF_TARGET_TTL) += ipt_TTL.o
+obj-$(CONFIG_IP_NF_TARGET_TPROXY) += ipt_TPROXY.o
 
 # generic ARP tables
 obj-$(CONFIG_IP_NF_ARPTABLES) += arp_tables.o
diff --git a/net/ipv4/netfilter/ipt_TPROXY.c b/net/ipv4/netfilter/ipt_TPROXY.c
new file mode 100644
index 0000000..6f64717
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_TPROXY.c
@@ -0,0 +1,103 @@
+/*
+ * 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/skbuff.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/udp.h>
+#include <net/inet_sock.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ip_tproxy.h>
+#include <linux/netfilter_ipv4/ipt_TPROXY.h>
+
+static unsigned int
+target(struct sk_buff **pskb,
+       const struct net_device *in,
+       const struct net_device *out,
+       unsigned int hooknum,
+       const struct xt_target *target,
+       const void *targinfo)
+{
+       const struct iphdr *iph = (*pskb)->nh.iph;
+       unsigned int verdict = NF_ACCEPT;
+       struct sk_buff *skb = *pskb;
+       struct udphdr _hdr, *hp;
+       struct sock *sk;
+
+       /* TCP/UDP only */
+       if ((iph->protocol != IPPROTO_TCP) &&
+           (iph->protocol != IPPROTO_UDP))
+               return NF_ACCEPT;
+
+       if (in == NULL)
+               return NF_ACCEPT;
+
+       if ((skb->dst != NULL) || (skb->ip_tproxy == 1))
+               return NF_ACCEPT;
+
+       hp = skb_header_pointer(*pskb, iph->ihl * 4, sizeof(_hdr), &_hdr);
+       if (hp == NULL)
+               return NF_DROP;
+
+       sk = ip_tproxy_get_sock(iph->protocol,
+                               iph->saddr, iph->daddr,
+                               hp->source, hp->dest, in);
+       if (sk != NULL) {
+               if (ip_tproxy_do_divert(skb, sk, 0, in) < 0)
+                       verdict = NF_DROP;
+               sock_put(sk);
+       }
+
+       return verdict;
+}
+
+static int
+checkentry(const char *tablename,
+          const void *e,
+          const struct xt_target *target,
+           void *targinfo,
+           unsigned int hook_mask)
+{
+       /* checks are now done by the x_tables core based on
+        * information specified in the ipt_target structure */
+       return 1;
+}
+
+static struct ipt_target ipt_tproxy_reg = {
+       .name           = "TPROXY",
+       .target         = target,
+       .targetsize     = sizeof(struct ipt_tproxy_target_info),
+       .table          = "tproxy",
+       .checkentry     = checkentry,
+       .me             = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+       if (ipt_register_target(&ipt_tproxy_reg))
+               return -EINVAL;
+
+       return 0;
+}
+
+static void __exit fini(void)
+{
+       ipt_unregister_target(&ipt_tproxy_reg);
+}
+
+module_init(init);
+module_exit(fini);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Krisztian Kovacs <[EMAIL PROTECTED]>");
+MODULE_DESCRIPTION("Netfilter transparent proxy TPROXY target module.");
-
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