[linux-2.6-block.git] / net / netfilter / nf_nat_proto_udplite.c

/* (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/udp.h>

#include <linux/netfilter.h>
#include <linux/module.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/netfilter/nf_nat_l4proto.h>

static u16 udplite_port_rover;

static void
udplite_unique_tuple(const struct nf_nat_l3proto *l3proto,
		     struct nf_conntrack_tuple *tuple,
		     const struct nf_nat_range *range,
		     enum nf_nat_manip_type maniptype,
		     const struct nf_conn *ct)
{
	nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct,
				    &udplite_port_rover);
}

static bool
udplite_manip_pkt(struct sk_buff *skb,
		  const struct nf_nat_l3proto *l3proto,
		  unsigned int iphdroff, unsigned int hdroff,
		  const struct nf_conntrack_tuple *tuple,
		  enum nf_nat_manip_type maniptype)
{
	struct udphdr *hdr;
	__be16 *portptr, newport;

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

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

	if (maniptype == NF_NAT_MANIP_SRC) {
		/* Get rid of source port */
		newport = tuple->src.u.udp.port;
		portptr = &hdr->source;
	} else {
		/* Get rid of dst port */
		newport = tuple->dst.u.udp.port;
		portptr = &hdr->dest;
	}

	l3proto->csum_update(skb, iphdroff, &hdr->check, tuple, maniptype);
	inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, 0);
	if (!hdr->check)
		hdr->check = CSUM_MANGLED_0;

	*portptr = newport;
	return true;
}

static const struct nf_nat_l4proto nf_nat_l4proto_udplite = {
	.l4proto		= IPPROTO_UDPLITE,
	.manip_pkt		= udplite_manip_pkt,
	.in_range		= nf_nat_l4proto_in_range,
	.unique_tuple		= udplite_unique_tuple,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
	.nlattr_to_range	= nf_nat_l4proto_nlattr_to_range,
#endif
};

static int __init nf_nat_proto_udplite_init(void)
{
	int err;

	err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
	if (err < 0)
		goto err1;
	err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_udplite);
	if (err < 0)
		goto err2;
	return 0;

err2:
	nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
err1:
	return err;
}

static void __exit nf_nat_proto_udplite_fini(void)
{
	nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_udplite);
	nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_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>");
Commit	Line	Data
6185f870 PM	1	/* (C) 1999-2001 Paul `Rusty' Russell
	2	* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
	3	* (C) 2008 Patrick McHardy <kaber@trash.net>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*/
	9
	10	#include <linux/types.h>
	11	#include <linux/init.h>
6185f870 PM	12	#include <linux/udp.h>
	13
	14	#include <linux/netfilter.h>
3a9a231d	15	#include <linux/module.h>
6185f870	16	#include <net/netfilter/nf_nat.h>
c7232c99 PM	17	#include <net/netfilter/nf_nat_l3proto.h>
c7232c99 PM	18	#include <net/netfilter/nf_nat_l4proto.h>
6185f870	19
c7232c99	20	static u16 udplite_port_rover;
6185f870	21
f43dc98b	22	static void
c7232c99 PM	23	udplite_unique_tuple(const struct nf_nat_l3proto *l3proto,
	24	struct nf_conntrack_tuple *tuple,
	25	const struct nf_nat_range *range,
6185f870 PM	26	enum nf_nat_manip_type maniptype,
	27	const struct nf_conn *ct)
	28	{
c7232c99 PM	29	nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct,
c7232c99 PM	30	&udplite_port_rover);
6185f870 PM	31	}
6185f870 PM	32
f2ea825f	33	static bool
6185f870	34	udplite_manip_pkt(struct sk_buff *skb,
c7232c99 PM	35	const struct nf_nat_l3proto *l3proto,
c7232c99 PM	36	unsigned int iphdroff, unsigned int hdroff,
6185f870 PM	37	const struct nf_conntrack_tuple *tuple,
	38	enum nf_nat_manip_type maniptype)
	39	{
6185f870	40	struct udphdr *hdr;
6185f870 PM	41	__be16 *portptr, newport;
	42
	43	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
f2ea825f	44	return false;
6185f870	45
6185f870 PM	46	hdr = (struct udphdr *)(skb->data + hdroff);
6185f870 PM	47
cbc9f2f4	48	if (maniptype == NF_NAT_MANIP_SRC) {
c7232c99	49	/* Get rid of source port */
6185f870 PM	50	newport = tuple->src.u.udp.port;
	51	portptr = &hdr->source;
	52	} else {
c7232c99	53	/* Get rid of dst port */
6185f870 PM	54	newport = tuple->dst.u.udp.port;
	55	portptr = &hdr->dest;
	56	}
	57
c7232c99	58	l3proto->csum_update(skb, iphdroff, &hdr->check, tuple, maniptype);
6185f870 PM	59	inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, 0);
	60	if (!hdr->check)
	61	hdr->check = CSUM_MANGLED_0;
	62
	63	*portptr = newport;
f2ea825f	64	return true;
6185f870 PM	65	}
6185f870 PM	66
c7232c99 PM	67	static const struct nf_nat_l4proto nf_nat_l4proto_udplite = {
c7232c99 PM	68	.l4proto = IPPROTO_UDPLITE,
6185f870	69	.manip_pkt = udplite_manip_pkt,
c7232c99	70	.in_range = nf_nat_l4proto_in_range,
6185f870	71	.unique_tuple = udplite_unique_tuple,
24de3d37	72	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
c7232c99	73	.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
6185f870 PM	74	#endif
	75	};
	76
	77	static int __init nf_nat_proto_udplite_init(void)
	78	{
c7232c99 PM	79	int err;
	80
	81	err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
	82	if (err < 0)
	83	goto err1;
	84	err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_udplite);
	85	if (err < 0)
	86	goto err2;
	87	return 0;
	88
	89	err2:
	90	nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
	91	err1:
	92	return err;
6185f870 PM	93	}
	94
	95	static void __exit nf_nat_proto_udplite_fini(void)
	96	{
c7232c99 PM	97	nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_udplite);
c7232c99 PM	98	nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
6185f870 PM	99	}
	100
	101	module_init(nf_nat_proto_udplite_init);
	102	module_exit(nf_nat_proto_udplite_fini);
	103
	104	MODULE_LICENSE("GPL");
	105	MODULE_DESCRIPTION("UDP-Lite NAT protocol helper");
	106	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");