[mirror_ubuntu-artful-kernel.git] / net / netfilter / nf_nat_proto_udp.c

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 *
 * 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/export.h>
#include <linux/init.h>
#include <linux/udp.h>

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

static u16 udp_port_rover;

static void
udp_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,
				    &udp_port_rover);
}

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

	if (maniptype == NF_NAT_MANIP_SRC) {
		/* Get rid of src 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;
	}
	if (do_csum) {
		l3proto->csum_update(skb, iphdroff, &hdr->check,
				     tuple, maniptype);
		inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport,
					 false);
		if (!hdr->check)
			hdr->check = CSUM_MANGLED_0;
	}
	*portptr = newport;
}

static bool udp_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;
	bool do_csum;

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

	hdr = (struct udphdr *)(skb->data + hdroff);
	do_csum = hdr->check || skb->ip_summed == CHECKSUM_PARTIAL;

	__udp_manip_pkt(skb, l3proto, iphdroff, hdr, tuple, maniptype, do_csum);
	return true;
}

#ifdef CONFIG_NF_NAT_PROTO_UDPLITE
static u16 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;

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

	hdr = (struct udphdr *)(skb->data + hdroff);
	__udp_manip_pkt(skb, l3proto, iphdroff, hdr, tuple, maniptype, true);
	return true;
}

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);
}

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
};
#endif /* CONFIG_NF_NAT_PROTO_UDPLITE */

const struct nf_nat_l4proto nf_nat_l4proto_udp = {
	.l4proto		= IPPROTO_UDP,
	.manip_pkt		= udp_manip_pkt,
	.in_range		= nf_nat_l4proto_in_range,
	.unique_tuple		= udp_unique_tuple,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
	.nlattr_to_range	= nf_nat_l4proto_nlattr_to_range,
#endif
};
Commit	Line	Data
5b1158e9 JK	1	/* (C) 1999-2001 Paul `Rusty' Russell
	2	* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/types.h>
bc3b2d7f	10	#include <linux/export.h>
5b1158e9	11	#include <linux/init.h>
5b1158e9 JK	12	#include <linux/udp.h>
	13
	14	#include <linux/netfilter.h>
	15	#include <net/netfilter/nf_nat.h>
	16	#include <net/netfilter/nf_nat_core.h>
c7232c99 PM	17	#include <net/netfilter/nf_nat_l3proto.h>
c7232c99 PM	18	#include <net/netfilter/nf_nat_l4proto.h>
5b1158e9	19
c7232c99	20	static u16 udp_port_rover;
5b1158e9	21
f43dc98b	22	static void
c7232c99 PM	23	udp_unique_tuple(const struct nf_nat_l3proto *l3proto,
	24	struct nf_conntrack_tuple *tuple,
	25	const struct nf_nat_range *range,
5b1158e9 JK	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	&udp_port_rover);
5b1158e9 JK	31	}
5b1158e9 JK	32
9700ba80 FW	33	static void
	34	__udp_manip_pkt(struct sk_buff *skb,
	35	const struct nf_nat_l3proto *l3proto,
	36	unsigned int iphdroff, struct udphdr *hdr,
	37	const struct nf_conntrack_tuple *tuple,
	38	enum nf_nat_manip_type maniptype, bool do_csum)
5b1158e9	39	{
5b1158e9 JK	40	__be16 *portptr, newport;
5b1158e9 JK	41
cbc9f2f4	42	if (maniptype == NF_NAT_MANIP_SRC) {
c7232c99	43	/* Get rid of src port */
5b1158e9 JK	44	newport = tuple->src.u.udp.port;
	45	portptr = &hdr->source;
	46	} else {
c7232c99	47	/* Get rid of dst port */
5b1158e9 JK	48	newport = tuple->dst.u.udp.port;
	49	portptr = &hdr->dest;
	50	}
9700ba80	51	if (do_csum) {
c7232c99 PM	52	l3proto->csum_update(skb, iphdroff, &hdr->check,
c7232c99 PM	53	tuple, maniptype);
be0ea7d5	54	inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport,
4b048d6d	55	false);
5b1158e9 JK	56	if (!hdr->check)
	57	hdr->check = CSUM_MANGLED_0;
	58	}
	59	*portptr = newport;
9700ba80 FW	60	}
	61
	62	static bool udp_manip_pkt(struct sk_buff *skb,
	63	const struct nf_nat_l3proto *l3proto,
	64	unsigned int iphdroff, unsigned int hdroff,
	65	const struct nf_conntrack_tuple *tuple,
	66	enum nf_nat_manip_type maniptype)
	67	{
	68	struct udphdr *hdr;
	69	bool do_csum;
	70
	71	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
	72	return false;
	73
	74	hdr = (struct udphdr *)(skb->data + hdroff);
	75	do_csum = hdr->check \|\| skb->ip_summed == CHECKSUM_PARTIAL;
	76
	77	__udp_manip_pkt(skb, l3proto, iphdroff, hdr, tuple, maniptype, do_csum);
	78	return true;
	79	}
	80
	81	#ifdef CONFIG_NF_NAT_PROTO_UDPLITE
	82	static u16 udplite_port_rover;
	83
	84	static bool udplite_manip_pkt(struct sk_buff *skb,
	85	const struct nf_nat_l3proto *l3proto,
	86	unsigned int iphdroff, unsigned int hdroff,
	87	const struct nf_conntrack_tuple *tuple,
	88	enum nf_nat_manip_type maniptype)
	89	{
	90	struct udphdr *hdr;
	91
	92	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
	93	return false;
	94
	95	hdr = (struct udphdr *)(skb->data + hdroff);
	96	__udp_manip_pkt(skb, l3proto, iphdroff, hdr, tuple, maniptype, true);
f2ea825f	97	return true;
5b1158e9 JK	98	}
5b1158e9 JK	99
9700ba80 FW	100	static void
	101	udplite_unique_tuple(const struct nf_nat_l3proto *l3proto,
	102	struct nf_conntrack_tuple *tuple,
	103	const struct nf_nat_range *range,
	104	enum nf_nat_manip_type maniptype,
	105	const struct nf_conn *ct)
	106	{
	107	nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct,
	108	&udplite_port_rover);
	109	}
	110
	111	const struct nf_nat_l4proto nf_nat_l4proto_udplite = {
	112	.l4proto = IPPROTO_UDPLITE,
	113	.manip_pkt = udplite_manip_pkt,
	114	.in_range = nf_nat_l4proto_in_range,
	115	.unique_tuple = udplite_unique_tuple,
	116	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
	117	.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
	118	#endif
	119	};
	120	#endif /* CONFIG_NF_NAT_PROTO_UDPLITE */
	121
c7232c99 PM	122	const struct nf_nat_l4proto nf_nat_l4proto_udp = {
c7232c99 PM	123	.l4proto = IPPROTO_UDP,
5b1158e9	124	.manip_pkt = udp_manip_pkt,
c7232c99	125	.in_range = nf_nat_l4proto_in_range,
5b1158e9	126	.unique_tuple = udp_unique_tuple,
24de3d37	127	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
c7232c99	128	.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
5b1158e9 JK	129	#endif
5b1158e9 JK	130	};