[linux-block.git] / net / ipv6 / xfrm6_mode_tunnel.c

/*
 * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
 *
 * Copyright (C) 2002 USAGI/WIDE Project
 * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <linux/gfp.h>
#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/ip6_route.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
	struct ipv6hdr *outer_iph = ipv6_hdr(skb);
	struct ipv6hdr *inner_iph = ipipv6_hdr(skb);

	if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
		IP6_ECN_set_ce(inner_iph);
}

/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.
 */
static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *top_iph;
	int dsfield;

	skb_set_network_header(skb, -x->props.header_len);
	skb->mac_header = skb->network_header +
			  offsetof(struct ipv6hdr, nexthdr);
	skb->transport_header = skb->network_header + sizeof(*top_iph);
	top_iph = ipv6_hdr(skb);

	top_iph->version = 6;

	memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	       sizeof(top_iph->flow_lbl));
	top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);

	dsfield = XFRM_MODE_SKB_CB(skb)->tos;
	dsfield = INET_ECN_encapsulate(dsfield, dsfield);
	if (x->props.flags & XFRM_STATE_NOECN)
		dsfield &= ~INET_ECN_MASK;
	ipv6_change_dsfield(top_iph, 0, dsfield);
	top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
	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_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
	int err = -EINVAL;
	const unsigned char *old_mac;

	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
		goto out;
	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
		goto out;

	if (skb_cloned(skb) &&
	    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
		goto out;

	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
		ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
			       ipipv6_hdr(skb));
	if (!(x->props.flags & XFRM_STATE_NOECN))
		ipip6_ecn_decapsulate(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);
	skb_reset_network_header(skb);
	err = 0;

out:
	return err;
}

static struct xfrm_mode xfrm6_tunnel_mode = {
	.input2 = xfrm6_mode_tunnel_input,
	.input = xfrm_prepare_input,
	.output2 = xfrm6_mode_tunnel_output,
	.output = xfrm6_prepare_output,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_TUNNEL,
	.flags = XFRM_MODE_FLAG_TUNNEL,
};

static int __init xfrm6_mode_tunnel_init(void)
{
	return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
}

static void __exit xfrm6_mode_tunnel_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
	BUG_ON(err);
}

module_init(xfrm6_mode_tunnel_init);
module_exit(xfrm6_mode_tunnel_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
Commit	Line	Data
b59f45d0 HX	1	/*
	2	* xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
	3	*
	4	* Copyright (C) 2002 USAGI/WIDE Project
	5	* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
	6	*/
	7
5a0e3ad6	8	#include <linux/gfp.h>
b59f45d0 HX	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/skbuff.h>
	13	#include <linux/stringify.h>
	14	#include <net/dsfield.h>
	15	#include <net/dst.h>
	16	#include <net/inet_ecn.h>
abbf46ae	17	#include <net/ip6_route.h>
b59f45d0 HX	18	#include <net/ipv6.h>
	19	#include <net/xfrm.h>
	20
	21	static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
	22	{
0660e03f	23	struct ipv6hdr *outer_iph = ipv6_hdr(skb);
39b89160	24	struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
b59f45d0 HX	25
	26	if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
	27	IP6_ECN_set_ce(inner_iph);
	28	}
	29
	30	/* Add encapsulation header.
	31	*
ceb1eec8	32	* The top IP header will be constructed per RFC 2401.
b59f45d0	33	*/
195ad6a3	34	static int xfrm6_mode_tunnel_output(struct xfrm_state x, struct sk_buff skb)
b59f45d0	35	{
adf30907	36	struct dst_entry *dst = skb_dst(skb);
36cf9acf	37	struct ipv6hdr *top_iph;
b59f45d0 HX	38	int dsfield;
b59f45d0 HX	39
7b277b1a	40	skb_set_network_header(skb, -x->props.header_len);
37fedd3a HX	41	skb->mac_header = skb->network_header +
37fedd3a HX	42	offsetof(struct ipv6hdr, nexthdr);
36cf9acf	43	skb->transport_header = skb->network_header + sizeof(*top_iph);
0660e03f	44	top_iph = ipv6_hdr(skb);
b59f45d0 HX	45
b59f45d0 HX	46	top_iph->version = 6;
36cf9acf HX	47
	48	memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	49	sizeof(top_iph->flow_lbl));
adf30907	50	top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
36cf9acf HX	51
36cf9acf HX	52	dsfield = XFRM_MODE_SKB_CB(skb)->tos;
b59f45d0 HX	53	dsfield = INET_ECN_encapsulate(dsfield, dsfield);
	54	if (x->props.flags & XFRM_STATE_NOECN)
	55	dsfield &= ~INET_ECN_MASK;
	56	ipv6_change_dsfield(top_iph, 0, dsfield);
abbf46ae	57	top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
b59f45d0 HX	58	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
	59	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
	60	return 0;
	61	}
	62
195ad6a3	63	static int xfrm6_mode_tunnel_input(struct xfrm_state x, struct sk_buff skb)
b59f45d0 HX	64	{
b59f45d0 HX	65	int err = -EINVAL;
39f69c6f	66	const unsigned char *old_mac;
b59f45d0	67
227620e2	68	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
b59f45d0 HX	69	goto out;
	70	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	71	goto out;
	72
	73	if (skb_cloned(skb) &&
	74	(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
	75	goto out;
	76
227620e2 HX	77	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
	78	ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
	79	ipipv6_hdr(skb));
	80	if (!(x->props.flags & XFRM_STATE_NOECN))
	81	ipip6_ecn_decapsulate(skb);
	82
98e399f8	83	old_mac = skb_mac_header(skb);
39f69c6f	84	skb_set_mac_header(skb, -skb->mac_len);
98e399f8	85	memmove(skb_mac_header(skb), old_mac, skb->mac_len);
c1d2bbe1	86	skb_reset_network_header(skb);
b59f45d0 HX	87	err = 0;
	88
	89	out:
	90	return err;
	91	}
	92
	93	static struct xfrm_mode xfrm6_tunnel_mode = {
195ad6a3	94	.input2 = xfrm6_mode_tunnel_input,
227620e2	95	.input = xfrm_prepare_input,
195ad6a3	96	.output2 = xfrm6_mode_tunnel_output,
36cf9acf	97	.output = xfrm6_prepare_output,
b59f45d0 HX	98	.owner = THIS_MODULE,
b59f45d0 HX	99	.encap = XFRM_MODE_TUNNEL,
1bfcb10f	100	.flags = XFRM_MODE_FLAG_TUNNEL,
b59f45d0 HX	101	};
b59f45d0 HX	102
195ad6a3	103	static int __init xfrm6_mode_tunnel_init(void)
b59f45d0 HX	104	{
	105	return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
	106	}
	107
195ad6a3	108	static void __exit xfrm6_mode_tunnel_exit(void)
b59f45d0 HX	109	{
	110	int err;
	111
	112	err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
	113	BUG_ON(err);
	114	}
	115
195ad6a3 HX	116	module_init(xfrm6_mode_tunnel_init);
195ad6a3 HX	117	module_exit(xfrm6_mode_tunnel_exit);
b59f45d0 HX	118	MODULE_LICENSE("GPL");
b59f45d0 HX	119	MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);