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Commit 6185f870 authored by Patrick McHardy's avatar Patrick McHardy
Browse files

[NETFILTER]: nf_nat: add UDP-Lite support



Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 2d2d84c4
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+5 −0
Original line number Diff line number Diff line
@@ -245,6 +245,11 @@ config NF_NAT_PROTO_GRE
	tristate
	depends on NF_NAT && NF_CT_PROTO_GRE

config NF_NAT_PROTO_UDPLITE
	tristate
	depends on NF_NAT && NF_CT_PROTO_UDPLITE
	default NF_NAT && NF_CT_PROTO_UDPLITE

config NF_NAT_FTP
	tristate
	depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o

# NAT protocols (nf_nat)
obj-$(CONFIG_NF_NAT_PROTO_GRE) += nf_nat_proto_gre.o
obj-$(CONFIG_NF_NAT_PROTO_UDPLITE) += nf_nat_proto_udplite.o

# generic IP tables 
obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
+99 −0
Original line number Diff line number Diff line
/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 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/types.h>
#include <linux/init.h>
#include <linux/ip.h>
#include <linux/udp.h>

#include <linux/netfilter.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_protocol.h>

static u_int16_t udplite_port_rover;

static int
udplite_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,
					 &udplite_port_rover);
}

static int
udplite_manip_pkt(struct sk_buff *skb,
		  unsigned int iphdroff,
		  const struct nf_conntrack_tuple *tuple,
		  enum nf_nat_manip_type maniptype)
{
	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
	struct udphdr *hdr;
	unsigned int hdroff = iphdroff + iph->ihl*4;
	__be32 oldip, newip;
	__be16 *portptr, newport;

	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
		return 0;

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

	if (maniptype == IP_NAT_MANIP_SRC) {
		/* Get rid of src ip and src pt */
		oldip = iph->saddr;
		newip = tuple->src.u3.ip;
		newport = tuple->src.u.udp.port;
		portptr = &hdr->source;
	} else {
		/* Get rid of dst ip and dst pt */
		oldip = iph->daddr;
		newip = tuple->dst.u3.ip;
		newport = tuple->dst.u.udp.port;
		portptr = &hdr->dest;
	}

	inet_proto_csum_replace4(&hdr->check, skb, oldip, newip, 1);
	inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, 0);
	if (!hdr->check)
		hdr->check = CSUM_MANGLED_0;

	*portptr = newport;
	return 1;
}

static const struct nf_nat_protocol nf_nat_protocol_udplite = {
	.protonum		= IPPROTO_UDPLITE,
	.me			= THIS_MODULE,
	.manip_pkt		= udplite_manip_pkt,
	.in_range		= nf_nat_proto_in_range,
	.unique_tuple		= udplite_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_udplite_init(void)
{
	return nf_nat_protocol_register(&nf_nat_protocol_udplite);
}

static void __exit nf_nat_proto_udplite_fini(void)
{
	nf_nat_protocol_unregister(&nf_nat_protocol_udplite);
}

module_init(nf_nat_proto_udplite_init);
module_exit(nf_nat_proto_udplite_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("UDP-Lite NAT protocol helper");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+4 −2
Original line number Diff line number Diff line
@@ -50,7 +50,8 @@ static void nat_decode_session(struct sk_buff *skb, struct flowi *fl)
	if (ct->status & statusbit) {
		fl->fl4_dst = t->dst.u3.ip;
		if (t->dst.protonum == IPPROTO_TCP ||
		    t->dst.protonum == IPPROTO_UDP)
		    t->dst.protonum == IPPROTO_UDP ||
		    t->dst.protonum == IPPROTO_UDPLITE)
			fl->fl_ip_dport = t->dst.u.tcp.port;
	}

@@ -59,7 +60,8 @@ static void nat_decode_session(struct sk_buff *skb, struct flowi *fl)
	if (ct->status & statusbit) {
		fl->fl4_src = t->src.u3.ip;
		if (t->dst.protonum == IPPROTO_TCP ||
		    t->dst.protonum == IPPROTO_UDP)
		    t->dst.protonum == IPPROTO_UDP ||
		    t->dst.protonum == IPPROTO_UDPLITE)
			fl->fl_ip_sport = t->src.u.tcp.port;
	}
}