Commit 4910a087 authored by Patrick McHardy's avatar Patrick McHardy
Browse files

[NETFILTER]: nf_nat: add DCCP protocol support 



Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 2bc78049

net/ipv4/netfilter/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -241,6 +241,11 @@ config NF_NAT_SNMP_BASIC 
#           <expr> '&&' <expr>                   (6)

#

# (6) Returns the result of min(/expr/, /expr/).

config NF_NAT_PROTO_DCCP

	tristate

	depends on NF_NAT && NF_CT_PROTO_DCCP

	default NF_NAT && NF_CT_PROTO_DCCP



config NF_NAT_PROTO_GRE

	tristate

	depends on NF_NAT && NF_CT_PROTO_GRE

net/ipv4/netfilter/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o 
obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o



# NAT protocols (nf_nat)

obj-$(CONFIG_NF_NAT_PROTO_DCCP) += nf_nat_proto_dccp.o

obj-$(CONFIG_NF_NAT_PROTO_GRE) += nf_nat_proto_gre.o

obj-$(CONFIG_NF_NAT_PROTO_UDPLITE) += nf_nat_proto_udplite.o

net/ipv4/netfilter/nf_nat_proto_dccp.c

0 → 100644
+108 −0
Original line number Diff line number Diff line 
/*

 * DCCP NAT protocol helper

 *

 * Copyright (c) 2005, 2006. 2008 Patrick McHardy <kaber@trash.net>

 *

 * 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/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/skbuff.h>

#include <linux/ip.h>

#include <linux/dccp.h>



#include <net/netfilter/nf_conntrack.h>

#include <net/netfilter/nf_nat.h>

#include <net/netfilter/nf_nat_protocol.h>



static u_int16_t dccp_port_rover;



static int

dccp_unique_tuple(struct nf_conntrack_tuple *tuple,

		  const struct nf_nat_range *range,

		  enum nf_nat_manip_type maniptype,

		  const struct nf_conn *ct)

{

	return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,

					 &dccp_port_rover);

}



static int

dccp_manip_pkt(struct sk_buff *skb,

	       unsigned int iphdroff,

	       const struct nf_conntrack_tuple *tuple,

	       enum nf_nat_manip_type maniptype)

{

	struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);

	struct dccp_hdr *hdr;

	unsigned int hdroff = iphdroff + iph->ihl * 4;

	__be32 oldip, newip;

	__be16 *portptr, oldport, newport;

	int hdrsize = 8; /* DCCP connection tracking guarantees this much */



	if (skb->len >= hdroff + sizeof(struct dccp_hdr))

		hdrsize = sizeof(struct dccp_hdr);



	if (!skb_make_writable(skb, hdroff + hdrsize))

		return 0;



	iph = (struct iphdr *)(skb->data + iphdroff);

	hdr = (struct dccp_hdr *)(skb->data + hdroff);



	if (maniptype == IP_NAT_MANIP_SRC) {

		oldip = iph->saddr;

		newip = tuple->src.u3.ip;

		newport = tuple->src.u.dccp.port;

		portptr = &hdr->dccph_sport;

	} else {

		oldip = iph->daddr;

		newip = tuple->dst.u3.ip;

		newport = tuple->dst.u.dccp.port;

		portptr = &hdr->dccph_dport;

	}



	oldport = *portptr;

	*portptr = newport;



	if (hdrsize < sizeof(*hdr))

		return 1;



	inet_proto_csum_replace4(&hdr->dccph_checksum, skb, oldip, newip, 1);

	inet_proto_csum_replace2(&hdr->dccph_checksum, skb, oldport, newport,

				 0);

	return 1;

}



static const struct nf_nat_protocol nf_nat_protocol_dccp = {

	.protonum		= IPPROTO_DCCP,

	.me			= THIS_MODULE,

	.manip_pkt		= dccp_manip_pkt,

	.in_range		= nf_nat_proto_in_range,

	.unique_tuple		= dccp_unique_tuple,

#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)

	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,

	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,

#endif

};



static int __init nf_nat_proto_dccp_init(void)

{

	return nf_nat_protocol_register(&nf_nat_protocol_dccp);

}



static void __exit nf_nat_proto_dccp_fini(void)

{

	nf_nat_protocol_unregister(&nf_nat_protocol_dccp);

}



module_init(nf_nat_proto_dccp_init);

module_exit(nf_nat_proto_dccp_fini);



MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");

MODULE_DESCRIPTION("DCCP NAT protocol helper");

MODULE_LICENSE("GPL");

net/ipv4/netfilter/nf_nat_standalone.c

+4 −2
Original line number Diff line number Diff line
@@ -51,7 +51,8 @@ static void nat_decode_session(struct sk_buff *skb, struct flowi *fl) 
		fl->fl4_dst = t->dst.u3.ip;

		if (t->dst.protonum == IPPROTO_TCP ||

		    t->dst.protonum == IPPROTO_UDP ||

		    t->dst.protonum == IPPROTO_UDPLITE)

		    t->dst.protonum == IPPROTO_UDPLITE ||

		    t->dst.protonum == IPPROTO_DCCP)

			fl->fl_ip_dport = t->dst.u.tcp.port;

	}
@@ -61,7 +62,8 @@ static void nat_decode_session(struct sk_buff *skb, struct flowi *fl) 
		fl->fl4_src = t->src.u3.ip;

		if (t->dst.protonum == IPPROTO_TCP ||

		    t->dst.protonum == IPPROTO_UDP ||

		    t->dst.protonum == IPPROTO_UDPLITE)

		    t->dst.protonum == IPPROTO_UDPLITE ||

		    t->dst.protonum == IPPROTO_DCCP)

			fl->fl_ip_sport = t->src.u.tcp.port;

	}

}