[net-next-2.6.git] / net / ipv6 / xfrm6_mode_beet.c

/*
 * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
 *
 * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
 *                    Miika Komu     <miika@iki.fi>
 *                    Herbert Xu     <herbert@gondor.apana.org.au>
 *                    Abhinav Pathak <abhinav.pathak@hiit.fi>
 *                    Jeff Ahrenholz <ahrenholz@gmail.com>
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/stringify.h>
#include <net/dsfield.h>
#include <net/dst.h>
#include <net/inet_ecn.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

static void xfrm6_beet_make_header(struct sk_buff *skb)
{
	struct ipv6hdr *iph = ipv6_hdr(skb);

	iph->version = 6;

	memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	       sizeof(iph->flow_lbl));
	iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;

	ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
	iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
}

/* Add encapsulation header.
 *
 * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
 */
static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ipv6hdr *top_iph;
	struct ip_beet_phdr *ph;
	struct iphdr *iphv4;
	int optlen, hdr_len;

	iphv4 = ip_hdr(skb);
	hdr_len = 0;
	optlen = XFRM_MODE_SKB_CB(skb)->optlen;
	if (unlikely(optlen))
		hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);

	skb_set_network_header(skb, -x->props.header_len - hdr_len);
	if (x->sel.family != AF_INET6)
		skb->network_header += IPV4_BEET_PHMAXLEN;
	skb->mac_header = skb->network_header +
			  offsetof(struct ipv6hdr, nexthdr);
	skb->transport_header = skb->network_header + sizeof(*top_iph);
	ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len);

	xfrm6_beet_make_header(skb);

	top_iph = ipv6_hdr(skb);
	if (unlikely(optlen)) {

		BUG_ON(optlen < 0);

		ph->padlen = 4 - (optlen & 4);
		ph->hdrlen = optlen / 8;
		ph->nexthdr = top_iph->nexthdr;
		if (ph->padlen)
			memset(ph + 1, IPOPT_NOP, ph->padlen);

		top_iph->nexthdr = IPPROTO_BEETPH;
	}

	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
	return 0;
}

static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ipv6hdr *ip6h;
	const unsigned char *old_mac;
	int size = sizeof(struct ipv6hdr);
	int err;

	err = skb_cow_head(skb, size + skb->mac_len);
	if (err)
		goto out;

	__skb_push(skb, size);
	skb_reset_network_header(skb);

	old_mac = skb_mac_header(skb);
	skb_set_mac_header(skb, -skb->mac_len);
	memmove(skb_mac_header(skb), old_mac, skb->mac_len);

	xfrm6_beet_make_header(skb);

	ip6h = ipv6_hdr(skb);
	ip6h->payload_len = htons(skb->len - size);
	ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
	ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
	err = 0;
out:
	return err;
}

static struct xfrm_mode xfrm6_beet_mode = {
	.input2 = xfrm6_beet_input,
	.input = xfrm_prepare_input,
	.output2 = xfrm6_beet_output,
	.output = xfrm6_prepare_output,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_BEET,
	.flags = XFRM_MODE_FLAG_TUNNEL,
};

static int __init xfrm6_beet_init(void)
{
	return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
}

static void __exit xfrm6_beet_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
	BUG_ON(err);
}

module_init(xfrm6_beet_init);
module_exit(xfrm6_beet_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);
Commit	Line	Data
0a69452c DB	1	/*
	2	* xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
	3	*
	4	* Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
	5	* Miika Komu <miika@iki.fi>
	6	* Herbert Xu <herbert@gondor.apana.org.au>
	7	* Abhinav Pathak <abhinav.pathak@hiit.fi>
	8	* Jeff Ahrenholz <ahrenholz@gmail.com>
	9	*/
	10
	11	#include <linux/init.h>
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/stringify.h>
	16	#include <net/dsfield.h>
	17	#include <net/dst.h>
	18	#include <net/inet_ecn.h>
	19	#include <net/ipv6.h>
	20	#include <net/xfrm.h>
	21
227620e2 HX	22	static void xfrm6_beet_make_header(struct sk_buff *skb)
	23	{
	24	struct ipv6hdr *iph = ipv6_hdr(skb);
	25
	26	iph->version = 6;
	27
	28	memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	29	sizeof(iph->flow_lbl));
	30	iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;
	31
	32	ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
	33	iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
	34	}
	35
0a69452c DB	36	/* Add encapsulation header.
	37	*
	38	* The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
0a69452c DB	39	*/
	40	static int xfrm6_beet_output(struct xfrm_state x, struct sk_buff skb)
	41	{
36cf9acf	42	struct ipv6hdr *top_iph;
abf5cdb8 JK	43	struct ip_beet_phdr *ph;
	44	struct iphdr *iphv4;
	45	int optlen, hdr_len;
0a69452c	46
abf5cdb8 JK	47	iphv4 = ip_hdr(skb);
	48	hdr_len = 0;
	49	optlen = XFRM_MODE_SKB_CB(skb)->optlen;
	50	if (unlikely(optlen))
	51	hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
	52
	53	skb_set_network_header(skb, -x->props.header_len - hdr_len);
	54	if (x->sel.family != AF_INET6)
	55	skb->network_header += IPV4_BEET_PHMAXLEN;
36cf9acf HX	56	skb->mac_header = skb->network_header +
	57	offsetof(struct ipv6hdr, nexthdr);
	58	skb->transport_header = skb->network_header + sizeof(*top_iph);
abf5cdb8	59	ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len);
0a69452c	60
227620e2	61	xfrm6_beet_make_header(skb);
36cf9acf	62
227620e2	63	top_iph = ipv6_hdr(skb);
abf5cdb8 JK	64	if (unlikely(optlen)) {
	65
	66	BUG_ON(optlen < 0);
	67
	68	ph->padlen = 4 - (optlen & 4);
	69	ph->hdrlen = optlen / 8;
	70	ph->nexthdr = top_iph->nexthdr;
	71	if (ph->padlen)
	72	memset(ph + 1, IPOPT_NOP, ph->padlen);
	73
	74	top_iph->nexthdr = IPPROTO_BEETPH;
	75	}
36cf9acf	76
0a69452c DB	77	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
0a69452c DB	78	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
0a69452c DB	79	return 0;
	80	}
	81
	82	static int xfrm6_beet_input(struct xfrm_state x, struct sk_buff skb)
	83	{
	84	struct ipv6hdr *ip6h;
39f69c6f	85	const unsigned char *old_mac;
0a69452c	86	int size = sizeof(struct ipv6hdr);
227620e2	87	int err;
0a69452c	88
227620e2 HX	89	err = skb_cow_head(skb, size + skb->mac_len);
227620e2 HX	90	if (err)
0a69452c DB	91	goto out;
0a69452c DB	92
227620e2	93	__skb_push(skb, size);
c1d2bbe1	94	skb_reset_network_header(skb);
0a69452c	95
98e399f8	96	old_mac = skb_mac_header(skb);
39f69c6f	97	skb_set_mac_header(skb, -skb->mac_len);
98e399f8	98	memmove(skb_mac_header(skb), old_mac, skb->mac_len);
0a69452c	99
227620e2 HX	100	xfrm6_beet_make_header(skb);
227620e2 HX	101
0660e03f	102	ip6h = ipv6_hdr(skb);
0a69452c DB	103	ip6h->payload_len = htons(skb->len - size);
	104	ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
	105	ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
	106	err = 0;
	107	out:
	108	return err;
	109	}
	110
	111	static struct xfrm_mode xfrm6_beet_mode = {
227620e2 HX	112	.input2 = xfrm6_beet_input,
227620e2 HX	113	.input = xfrm_prepare_input,
36cf9acf HX	114	.output2 = xfrm6_beet_output,
36cf9acf HX	115	.output = xfrm6_prepare_output,
0a69452c DB	116	.owner = THIS_MODULE,
0a69452c DB	117	.encap = XFRM_MODE_BEET,
1bfcb10f	118	.flags = XFRM_MODE_FLAG_TUNNEL,
0a69452c DB	119	};
	120
	121	static int __init xfrm6_beet_init(void)
	122	{
	123	return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
	124	}
	125
	126	static void __exit xfrm6_beet_exit(void)
	127	{
	128	int err;
	129
	130	err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
	131	BUG_ON(err);
	132	}
	133
	134	module_init(xfrm6_beet_init);
	135	module_exit(xfrm6_beet_exit);
	136	MODULE_LICENSE("GPL");
	137	MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);