[net-next-2.6.git] / net / ipv6 / xfrm6_input.c

/*
 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
 *
 * Authors:
 *	Mitsuru KANDA @USAGI
 * 	Kazunori MIYAZAWA @USAGI
 * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 *	YOSHIFUJI Hideaki @USAGI
 *		IPv6 support
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
	struct ipv6hdr *outer_iph = skb->nh.ipv6h;
	struct ipv6hdr *inner_iph = skb->h.ipv6h;

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

int xfrm6_rcv_spi(struct sk_buff *skb, u32 spi)
{
	int err;
	u32 seq;
	struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
	struct xfrm_state *x;
	int xfrm_nr = 0;
	int decaps = 0;
	int nexthdr;
	unsigned int nhoff;

	nhoff = IP6CB(skb)->nhoff;
	nexthdr = skb->nh.raw[nhoff];

	seq = 0;
	if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
		goto drop;
	
	do {
		struct ipv6hdr *iph = skb->nh.ipv6h;

		if (xfrm_nr == XFRM_MAX_DEPTH)
			goto drop;

		x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6);
		if (x == NULL)
			goto drop;
		spin_lock(&x->lock);
		if (unlikely(x->km.state != XFRM_STATE_VALID))
			goto drop_unlock;

		if (x->props.replay_window && xfrm_replay_check(x, seq))
			goto drop_unlock;

		if (xfrm_state_check_expire(x))
			goto drop_unlock;

		nexthdr = x->type->input(x, skb);
		if (nexthdr <= 0)
			goto drop_unlock;

		skb->nh.raw[nhoff] = nexthdr;

		if (x->props.replay_window)
			xfrm_replay_advance(x, seq);

		x->curlft.bytes += skb->len;
		x->curlft.packets++;

		spin_unlock(&x->lock);

		xfrm_vec[xfrm_nr++] = x;

		if (x->props.mode) { /* XXX */
			if (nexthdr != IPPROTO_IPV6)
				goto drop;
			if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
				goto drop;
			if (skb_cloned(skb) &&
			    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
				goto drop;
			if (x->props.flags & XFRM_STATE_DECAP_DSCP)
				ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
			if (!(x->props.flags & XFRM_STATE_NOECN))
				ipip6_ecn_decapsulate(skb);
			skb->mac.raw = memmove(skb->data - skb->mac_len,
					       skb->mac.raw, skb->mac_len);
			skb->nh.raw = skb->data;
			decaps = 1;
			break;
		}

		if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) < 0)
			goto drop;
	} while (!err);

	/* Allocate new secpath or COW existing one. */
	if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
		struct sec_path *sp;
		sp = secpath_dup(skb->sp);
		if (!sp)
			goto drop;
		if (skb->sp)
			secpath_put(skb->sp);
		skb->sp = sp;
	}

	if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
		goto drop;

	memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec,
	       xfrm_nr * sizeof(xfrm_vec[0]));
	skb->sp->len += xfrm_nr;
	skb->ip_summed = CHECKSUM_NONE;

	nf_reset(skb);

	if (decaps) {
		if (!(skb->dev->flags&IFF_LOOPBACK)) {
			dst_release(skb->dst);
			skb->dst = NULL;
		}
		netif_rx(skb);
		return -1;
	} else {
#ifdef CONFIG_NETFILTER
		skb->nh.ipv6h->payload_len = htons(skb->len);
		__skb_push(skb, skb->data - skb->nh.raw);

		NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL,
		        ip6_rcv_finish);
		return -1;
#else
		return 1;
#endif
	}

drop_unlock:
	spin_unlock(&x->lock);
	xfrm_state_put(x);
drop:
	while (--xfrm_nr >= 0)
		xfrm_state_put(xfrm_vec[xfrm_nr]);
	kfree_skb(skb);
	return -1;
}

EXPORT_SYMBOL(xfrm6_rcv_spi);

int xfrm6_rcv(struct sk_buff **pskb)
{
	return xfrm6_rcv_spi(*pskb, 0);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* xfrm6_input.c: based on net/ipv4/xfrm4_input.c
	3	*
	4	* Authors:
	5	* Mitsuru KANDA @USAGI
	6	* Kazunori MIYAZAWA @USAGI
	7	* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
	8	* YOSHIFUJI Hideaki @USAGI
	9	* IPv6 support
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/string.h>
b05e1066 PM	14	#include <linux/netfilter.h>
b05e1066 PM	15	#include <linux/netfilter_ipv6.h>
1da177e4 LT	16	#include <net/dsfield.h>
	17	#include <net/inet_ecn.h>
	18	#include <net/ip.h>
	19	#include <net/ipv6.h>
	20	#include <net/xfrm.h>
	21
	22	static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
	23	{
	24	struct ipv6hdr *outer_iph = skb->nh.ipv6h;
	25	struct ipv6hdr *inner_iph = skb->h.ipv6h;
	26
	27	if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
	28	IP6_ECN_set_ce(inner_iph);
	29	}
	30
d2acc347	31	int xfrm6_rcv_spi(struct sk_buff *skb, u32 spi)
1da177e4	32	{
1da177e4 LT	33	int err;
1da177e4 LT	34	u32 seq;
dbe5b4aa	35	struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
1da177e4 LT	36	struct xfrm_state *x;
	37	int xfrm_nr = 0;
	38	int decaps = 0;
	39	int nexthdr;
	40	unsigned int nhoff;
	41
951dbc8a	42	nhoff = IP6CB(skb)->nhoff;
1da177e4 LT	43	nexthdr = skb->nh.raw[nhoff];
	44
	45	seq = 0;
	46	if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
	47	goto drop;
	48
	49	do {
	50	struct ipv6hdr *iph = skb->nh.ipv6h;
	51
	52	if (xfrm_nr == XFRM_MAX_DEPTH)
	53	goto drop;
	54
	55	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6);
	56	if (x == NULL)
	57	goto drop;
	58	spin_lock(&x->lock);
	59	if (unlikely(x->km.state != XFRM_STATE_VALID))
	60	goto drop_unlock;
	61
	62	if (x->props.replay_window && xfrm_replay_check(x, seq))
	63	goto drop_unlock;
	64
	65	if (xfrm_state_check_expire(x))
	66	goto drop_unlock;
	67
e695633e	68	nexthdr = x->type->input(x, skb);
1da177e4 LT	69	if (nexthdr <= 0)
	70	goto drop_unlock;
	71
	72	skb->nh.raw[nhoff] = nexthdr;
	73
	74	if (x->props.replay_window)
	75	xfrm_replay_advance(x, seq);
	76
	77	x->curlft.bytes += skb->len;
	78	x->curlft.packets++;
	79
	80	spin_unlock(&x->lock);
	81
dbe5b4aa	82	xfrm_vec[xfrm_nr++] = x;
1da177e4 LT	83
	84	if (x->props.mode) { /* XXX */
	85	if (nexthdr != IPPROTO_IPV6)
	86	goto drop;
	87	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	88	goto drop;
	89	if (skb_cloned(skb) &&
	90	pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
	91	goto drop;
	92	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
	93	ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
	94	if (!(x->props.flags & XFRM_STATE_NOECN))
	95	ipip6_ecn_decapsulate(skb);
	96	skb->mac.raw = memmove(skb->data - skb->mac_len,
	97	skb->mac.raw, skb->mac_len);
	98	skb->nh.raw = skb->data;
	99	decaps = 1;
	100	break;
	101	}
	102
	103	if ((err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) < 0)
	104	goto drop;
	105	} while (!err);
	106
	107	/* Allocate new secpath or COW existing one. */
	108	if (!skb->sp \|\| atomic_read(&skb->sp->refcnt) != 1) {
	109	struct sec_path *sp;
	110	sp = secpath_dup(skb->sp);
	111	if (!sp)
	112	goto drop;
	113	if (skb->sp)
	114	secpath_put(skb->sp);
	115	skb->sp = sp;
	116	}
	117
	118	if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
	119	goto drop;
	120
dbe5b4aa HX	121	memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec,
dbe5b4aa HX	122	xfrm_nr * sizeof(xfrm_vec[0]));
1da177e4 LT	123	skb->sp->len += xfrm_nr;
	124	skb->ip_summed = CHECKSUM_NONE;
	125
b05e1066 PM	126	nf_reset(skb);
b05e1066 PM	127
1da177e4 LT	128	if (decaps) {
	129	if (!(skb->dev->flags&IFF_LOOPBACK)) {
	130	dst_release(skb->dst);
	131	skb->dst = NULL;
	132	}
	133	netif_rx(skb);
	134	return -1;
	135	} else {
b05e1066 PM	136	#ifdef CONFIG_NETFILTER
	137	skb->nh.ipv6h->payload_len = htons(skb->len);
	138	__skb_push(skb, skb->data - skb->nh.raw);
	139
	140	NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL,
	141	ip6_rcv_finish);
	142	return -1;
	143	#else
1da177e4	144	return 1;
b05e1066	145	#endif
1da177e4 LT	146	}
	147
	148	drop_unlock:
	149	spin_unlock(&x->lock);
	150	xfrm_state_put(x);
	151	drop:
	152	while (--xfrm_nr >= 0)
dbe5b4aa	153	xfrm_state_put(xfrm_vec[xfrm_nr]);
1da177e4 LT	154	kfree_skb(skb);
	155	return -1;
	156	}
	157
	158	EXPORT_SYMBOL(xfrm6_rcv_spi);
	159
951dbc8a	160	int xfrm6_rcv(struct sk_buff **pskb)
1da177e4	161	{
d2acc347	162	return xfrm6_rcv_spi(*pskb, 0);
1da177e4	163	}