[NETFILTER]: nf_nat: add DCCP protocol support (4910a087) · Commits · e / devices / android_kernel_xiaomi_markw

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;
		}
		}