[deliverable/linux.git] / net / xfrm / xfrm_input.c

/*
 * xfrm_input.c
 *
 * Changes:
 * 	YOSHIFUJI Hideaki @USAGI
 * 		Split up af-specific portion
 *
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/xfrm.h>

static struct kmem_cache *secpath_cachep __read_mostly;

void __secpath_destroy(struct sec_path *sp)
{
	int i;
	for (i = 0; i < sp->len; i++)
		xfrm_state_put(sp->xvec[i]);
	kmem_cache_free(secpath_cachep, sp);
}
EXPORT_SYMBOL(__secpath_destroy);

struct sec_path *secpath_dup(struct sec_path *src)
{
	struct sec_path *sp;

	sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
	if (!sp)
		return NULL;

	sp->len = 0;
	if (src) {
		int i;

		memcpy(sp, src, sizeof(*sp));
		for (i = 0; i < sp->len; i++)
			xfrm_state_hold(sp->xvec[i]);
	}
	atomic_set(&sp->refcnt, 1);
	return sp;
}
EXPORT_SYMBOL(secpath_dup);

/* Fetch spi and seq from ipsec header */

int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
{
	int offset, offset_seq;
	int hlen;

	switch (nexthdr) {
	case IPPROTO_AH:
		hlen = sizeof(struct ip_auth_hdr);
		offset = offsetof(struct ip_auth_hdr, spi);
		offset_seq = offsetof(struct ip_auth_hdr, seq_no);
		break;
	case IPPROTO_ESP:
		hlen = sizeof(struct ip_esp_hdr);
		offset = offsetof(struct ip_esp_hdr, spi);
		offset_seq = offsetof(struct ip_esp_hdr, seq_no);
		break;
	case IPPROTO_COMP:
		if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
			return -EINVAL;
		*spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2)));
		*seq = 0;
		return 0;
	default:
		return 1;
	}

	if (!pskb_may_pull(skb, hlen))
		return -EINVAL;

	*spi = *(__be32*)(skb_transport_header(skb) + offset);
	*seq = *(__be32*)(skb_transport_header(skb) + offset_seq);
	return 0;
}
EXPORT_SYMBOL(xfrm_parse_spi);

int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;

	err = x->outer_mode->afinfo->extract_input(x, skb);
	if (err)
		return err;

	skb->protocol = x->inner_mode->afinfo->eth_proto;
	return x->inner_mode->input2(x, skb);
}
EXPORT_SYMBOL(xfrm_prepare_input);

int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
{
	int err;
	__be32 seq;
	struct xfrm_state *x;
	xfrm_address_t *daddr;
	unsigned int family;
	int decaps = 0;
	int async = 0;

	/* A negative encap_type indicates async resumption. */
	if (encap_type < 0) {
		async = 1;
		x = xfrm_input_state(skb);
		seq = XFRM_SKB_CB(skb)->seq;
		goto resume;
	}

	/* 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;
	}

	daddr = (xfrm_address_t *)(skb_network_header(skb) +
				   XFRM_SPI_SKB_CB(skb)->daddroff);
	family = XFRM_SPI_SKB_CB(skb)->family;

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

	do {
		if (skb->sp->len == XFRM_MAX_DEPTH)
			goto drop;

		x = xfrm_state_lookup(daddr, spi, nexthdr, family);
		if (x == NULL)
			goto drop;

		skb->sp->xvec[skb->sp->len++] = x;

		spin_lock(&x->lock);
		if (unlikely(x->km.state != XFRM_STATE_VALID))
			goto drop_unlock;

		if ((x->encap ? x->encap->encap_type : 0) != encap_type)
			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;

		spin_unlock(&x->lock);

		XFRM_SKB_CB(skb)->seq = seq;

		nexthdr = x->type->input(x, skb);

		if (nexthdr == -EINPROGRESS)
			return 0;

resume:
		spin_lock(&x->lock);
		if (nexthdr <= 0) {
			if (nexthdr == -EBADMSG)
				x->stats.integrity_failed++;
			goto drop_unlock;
		}

		/* only the first xfrm gets the encap type */
		encap_type = 0;

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

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

		spin_unlock(&x->lock);

		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;

		if (x->inner_mode->input(x, skb))
			goto drop;

		if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
			decaps = 1;
			break;
		}

		/*
		 * We need the inner address.  However, we only get here for
		 * transport mode so the outer address is identical.
		 */
		daddr = &x->id.daddr;
		family = x->outer_mode->afinfo->family;

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

	nf_reset(skb);

	if (decaps) {
		dst_release(skb->dst);
		skb->dst = NULL;
		netif_rx(skb);
		return 0;
	} else {
		return x->inner_mode->afinfo->transport_finish(skb, async);
	}

drop_unlock:
	spin_unlock(&x->lock);
drop:
	kfree_skb(skb);
	return 0;
}
EXPORT_SYMBOL(xfrm_input);

int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
{
	return xfrm_input(skb, nexthdr, 0, -1);
}
EXPORT_SYMBOL(xfrm_input_resume);

void __init xfrm_input_init(void)
{
	secpath_cachep = kmem_cache_create("secpath_cache",
					   sizeof(struct sec_path),
					   0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
					   NULL);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* xfrm_input.c
	3	*
	4	* Changes:
	5	* YOSHIFUJI Hideaki @USAGI
	6	* Split up af-specific portion
a716c119	7	*
1da177e4 LT	8	*/
	9
	10	#include <linux/slab.h>
	11	#include <linux/module.h>
716062fd HX	12	#include <linux/netdevice.h>
716062fd HX	13	#include <net/dst.h>
1da177e4 LT	14	#include <net/ip.h>
	15	#include <net/xfrm.h>
	16
e18b890b	17	static struct kmem_cache *secpath_cachep __read_mostly;
1da177e4 LT	18
	19	void __secpath_destroy(struct sec_path *sp)
	20	{
	21	int i;
	22	for (i = 0; i < sp->len; i++)
dbe5b4aa	23	xfrm_state_put(sp->xvec[i]);
1da177e4 LT	24	kmem_cache_free(secpath_cachep, sp);
	25	}
	26	EXPORT_SYMBOL(__secpath_destroy);
	27
	28	struct sec_path secpath_dup(struct sec_path src)
	29	{
	30	struct sec_path *sp;
	31
54e6ecb2	32	sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
1da177e4 LT	33	if (!sp)
	34	return NULL;
	35
	36	sp->len = 0;
	37	if (src) {
	38	int i;
	39
	40	memcpy(sp, src, sizeof(*sp));
	41	for (i = 0; i < sp->len; i++)
dbe5b4aa	42	xfrm_state_hold(sp->xvec[i]);
1da177e4 LT	43	}
	44	atomic_set(&sp->refcnt, 1);
	45	return sp;
	46	}
	47	EXPORT_SYMBOL(secpath_dup);
	48
	49	/* Fetch spi and seq from ipsec header */
	50
6067b2ba	51	int xfrm_parse_spi(struct sk_buff skb, u8 nexthdr, __be32 spi, __be32 *seq)
1da177e4 LT	52	{
1da177e4 LT	53	int offset, offset_seq;
44072500	54	int hlen;
1da177e4 LT	55
	56	switch (nexthdr) {
	57	case IPPROTO_AH:
44072500	58	hlen = sizeof(struct ip_auth_hdr);
1da177e4 LT	59	offset = offsetof(struct ip_auth_hdr, spi);
	60	offset_seq = offsetof(struct ip_auth_hdr, seq_no);
	61	break;
	62	case IPPROTO_ESP:
44072500	63	hlen = sizeof(struct ip_esp_hdr);
1da177e4 LT	64	offset = offsetof(struct ip_esp_hdr, spi);
	65	offset_seq = offsetof(struct ip_esp_hdr, seq_no);
	66	break;
	67	case IPPROTO_COMP:
	68	if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
	69	return -EINVAL;
9c70220b	70	spi = htonl(ntohs((__be16*)(skb_transport_header(skb) + 2)));
1da177e4 LT	71	*seq = 0;
	72	return 0;
	73	default:
	74	return 1;
	75	}
	76
44072500	77	if (!pskb_may_pull(skb, hlen))
1da177e4 LT	78	return -EINVAL;
1da177e4 LT	79
9c70220b ACM	80	spi = (__be32*)(skb_transport_header(skb) + offset);
9c70220b ACM	81	seq = (__be32*)(skb_transport_header(skb) + offset_seq);
1da177e4 LT	82	return 0;
	83	}
	84	EXPORT_SYMBOL(xfrm_parse_spi);
	85
227620e2 HX	86	int xfrm_prepare_input(struct xfrm_state x, struct sk_buff skb)
	87	{
	88	int err;
	89
	90	err = x->outer_mode->afinfo->extract_input(x, skb);
	91	if (err)
	92	return err;
	93
	94	skb->protocol = x->inner_mode->afinfo->eth_proto;
	95	return x->inner_mode->input2(x, skb);
	96	}
	97	EXPORT_SYMBOL(xfrm_prepare_input);
	98
716062fd HX	99	int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
	100	{
	101	int err;
	102	__be32 seq;
716062fd	103	struct xfrm_state *x;
1bf06cd2	104	xfrm_address_t *daddr;
2fcb45b6	105	unsigned int family;
716062fd	106	int decaps = 0;
1bf06cd2 HX	107	int async = 0;
	108
	109	/* A negative encap_type indicates async resumption. */
	110	if (encap_type < 0) {
	111	async = 1;
00501121	112	x = xfrm_input_state(skb);
1bf06cd2 HX	113	seq = XFRM_SKB_CB(skb)->seq;
	114	goto resume;
	115	}
716062fd	116
b2aa5e9d HX	117	/* Allocate new secpath or COW existing one. */
	118	if (!skb->sp \|\| atomic_read(&skb->sp->refcnt) != 1) {
	119	struct sec_path *sp;
	120
	121	sp = secpath_dup(skb->sp);
	122	if (!sp)
	123	goto drop;
	124	if (skb->sp)
	125	secpath_put(skb->sp);
	126	skb->sp = sp;
	127	}
	128
1bf06cd2 HX	129	daddr = (xfrm_address_t *)(skb_network_header(skb) +
1bf06cd2 HX	130	XFRM_SPI_SKB_CB(skb)->daddroff);
2fcb45b6	131	family = XFRM_SPI_SKB_CB(skb)->family;
1bf06cd2	132
716062fd HX	133	seq = 0;
	134	if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
	135	goto drop;
	136
	137	do {
b2aa5e9d	138	if (skb->sp->len == XFRM_MAX_DEPTH)
716062fd HX	139	goto drop;
716062fd HX	140
2fcb45b6	141	x = xfrm_state_lookup(daddr, spi, nexthdr, family);
716062fd HX	142	if (x == NULL)
	143	goto drop;
	144
b2aa5e9d HX	145	skb->sp->xvec[skb->sp->len++] = x;
b2aa5e9d HX	146
716062fd HX	147	spin_lock(&x->lock);
	148	if (unlikely(x->km.state != XFRM_STATE_VALID))
	149	goto drop_unlock;
	150
	151	if ((x->encap ? x->encap->encap_type : 0) != encap_type)
	152	goto drop_unlock;
	153
	154	if (x->props.replay_window && xfrm_replay_check(x, seq))
	155	goto drop_unlock;
	156
	157	if (xfrm_state_check_expire(x))
	158	goto drop_unlock;
	159
0ebea8ef HX	160	spin_unlock(&x->lock);
0ebea8ef HX	161
1bf06cd2 HX	162	XFRM_SKB_CB(skb)->seq = seq;
1bf06cd2 HX	163
716062fd	164	nexthdr = x->type->input(x, skb);
0ebea8ef	165
1bf06cd2 HX	166	if (nexthdr == -EINPROGRESS)
	167	return 0;
	168
	169	resume:
0ebea8ef	170	spin_lock(&x->lock);
668dc8af HX	171	if (nexthdr <= 0) {
	172	if (nexthdr == -EBADMSG)
	173	x->stats.integrity_failed++;
716062fd	174	goto drop_unlock;
668dc8af	175	}
716062fd	176
716062fd HX	177	/* only the first xfrm gets the encap type */
	178	encap_type = 0;
	179
	180	if (x->props.replay_window)
	181	xfrm_replay_advance(x, seq);
	182
	183	x->curlft.bytes += skb->len;
	184	x->curlft.packets++;
	185
	186	spin_unlock(&x->lock);
	187
60d5fcfb HX	188	XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
60d5fcfb HX	189
716062fd HX	190	if (x->inner_mode->input(x, skb))
	191	goto drop;
	192
	193	if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
	194	decaps = 1;
	195	break;
	196	}
	197
1bf06cd2 HX	198	/*
	199	* We need the inner address. However, we only get here for
	200	* transport mode so the outer address is identical.
	201	*/
	202	daddr = &x->id.daddr;
2fcb45b6	203	family = x->outer_mode->afinfo->family;
1bf06cd2	204
716062fd HX	205	err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
	206	if (err < 0)
	207	goto drop;
	208	} while (!err);
	209
716062fd HX	210	nf_reset(skb);
	211
	212	if (decaps) {
	213	dst_release(skb->dst);
	214	skb->dst = NULL;
	215	netif_rx(skb);
	216	return 0;
	217	} else {
1bf06cd2	218	return x->inner_mode->afinfo->transport_finish(skb, async);
716062fd HX	219	}
	220
	221	drop_unlock:
	222	spin_unlock(&x->lock);
716062fd	223	drop:
716062fd HX	224	kfree_skb(skb);
	225	return 0;
	226	}
	227	EXPORT_SYMBOL(xfrm_input);
	228
1bf06cd2 HX	229	int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
	230	{
	231	return xfrm_input(skb, nexthdr, 0, -1);
	232	}
	233	EXPORT_SYMBOL(xfrm_input_resume);
	234
1da177e4 LT	235	void __init xfrm_input_init(void)
	236	{
	237	secpath_cachep = kmem_cache_create("secpath_cache",
	238	sizeof(struct sec_path),
e5d679f3	239	0, SLAB_HWCACHE_ALIGN\|SLAB_PANIC,
20c2df83	240	NULL);
1da177e4	241	}