[linux-2.6-block.git] / net / ipv6 / xfrm6_input.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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/ipv6.h>
#include <net/xfrm.h>
#include <net/protocol.h>
#include <net/gro.h>

int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
		  struct ip6_tnl *t)
{
	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
	return xfrm_input(skb, nexthdr, spi, 0);
}
EXPORT_SYMBOL(xfrm6_rcv_spi);

static int xfrm6_transport_finish2(struct net *net, struct sock *sk,
				   struct sk_buff *skb)
{
	if (xfrm_trans_queue(skb, ip6_rcv_finish)) {
		kfree_skb(skb);
		return NET_RX_DROP;
	}

	return 0;
}

int xfrm6_transport_finish(struct sk_buff *skb, int async)
{
	struct xfrm_offload *xo = xfrm_offload(skb);
	int nhlen = skb->data - skb_network_header(skb);

	skb_network_header(skb)[IP6CB(skb)->nhoff] =
		XFRM_MODE_SKB_CB(skb)->protocol;

#ifndef CONFIG_NETFILTER
	if (!async)
		return 1;
#endif

	__skb_push(skb, nhlen);
	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
	skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);

	if (xo && (xo->flags & XFRM_GRO)) {
		skb_mac_header_rebuild(skb);
		skb_reset_transport_header(skb);
		return 0;
	}

	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
		dev_net(skb->dev), NULL, skb, skb->dev, NULL,
		xfrm6_transport_finish2);
	return 0;
}

static int __xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb, bool pull)
{
	struct udp_sock *up = udp_sk(sk);
	struct udphdr *uh;
	struct ipv6hdr *ip6h;
	int len;
	int ip6hlen = sizeof(struct ipv6hdr);
	__u8 *udpdata;
	__be32 *udpdata32;
	u16 encap_type;

	encap_type = READ_ONCE(up->encap_type);
	/* if this is not encapsulated socket, then just return now */
	if (!encap_type)
		return 1;

	/* If this is a paged skb, make sure we pull up
	 * whatever data we need to look at. */
	len = skb->len - sizeof(struct udphdr);
	if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
		return 1;

	/* Now we can get the pointers */
	uh = udp_hdr(skb);
	udpdata = (__u8 *)uh + sizeof(struct udphdr);
	udpdata32 = (__be32 *)udpdata;

	switch (encap_type) {
	default:
	case UDP_ENCAP_ESPINUDP:
		/* Check if this is a keepalive packet.  If so, eat it. */
		if (len == 1 && udpdata[0] == 0xff) {
			return -EINVAL;
		} else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
			/* ESP Packet without Non-ESP header */
			len = sizeof(struct udphdr);
		} else
			/* Must be an IKE packet.. pass it through */
			return 1;
		break;
	case UDP_ENCAP_ESPINUDP_NON_IKE:
		/* Check if this is a keepalive packet.  If so, eat it. */
		if (len == 1 && udpdata[0] == 0xff) {
			return -EINVAL;
		} else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
			   udpdata32[0] == 0 && udpdata32[1] == 0) {

			/* ESP Packet with Non-IKE marker */
			len = sizeof(struct udphdr) + 2 * sizeof(u32);
		} else
			/* Must be an IKE packet.. pass it through */
			return 1;
		break;
	}

	/* At this point we are sure that this is an ESPinUDP packet,
	 * so we need to remove 'len' bytes from the packet (the UDP
	 * header and optional ESP marker bytes) and then modify the
	 * protocol to ESP, and then call into the transform receiver.
	 */
	if (skb_unclone(skb, GFP_ATOMIC))
		return -EINVAL;

	/* Now we can update and verify the packet length... */
	ip6h = ipv6_hdr(skb);
	ip6h->payload_len = htons(ntohs(ip6h->payload_len) - len);
	if (skb->len < ip6hlen + len) {
		/* packet is too small!?! */
		return -EINVAL;
	}

	/* pull the data buffer up to the ESP header and set the
	 * transport header to point to ESP.  Keep UDP on the stack
	 * for later.
	 */
	if (pull) {
		__skb_pull(skb, len);
		skb_reset_transport_header(skb);
	} else {
		skb_set_transport_header(skb, len);
	}

	/* process ESP */
	return 0;
}

/* If it's a keepalive packet, then just eat it.
 * If it's an encapsulated packet, then pass it to the
 * IPsec xfrm input.
 * Returns 0 if skb passed to xfrm or was dropped.
 * Returns >0 if skb should be passed to UDP.
 * Returns <0 if skb should be resubmitted (-ret is protocol)
 */
int xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
{
	int ret;

	if (skb->protocol == htons(ETH_P_IP))
		return xfrm4_udp_encap_rcv(sk, skb);

	ret = __xfrm6_udp_encap_rcv(sk, skb, true);
	if (!ret)
		return xfrm6_rcv_encap(skb, IPPROTO_ESP, 0,
				       udp_sk(sk)->encap_type);

	if (ret < 0) {
		kfree_skb(skb);
		return 0;
	}

	return ret;
}

struct sk_buff *xfrm6_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
					struct sk_buff *skb)
{
	int offset = skb_gro_offset(skb);
	const struct net_offload *ops;
	struct sk_buff *pp = NULL;
	int ret;

	if (skb->protocol == htons(ETH_P_IP))
		return xfrm4_gro_udp_encap_rcv(sk, head, skb);

	offset = offset - sizeof(struct udphdr);

	if (!pskb_pull(skb, offset))
		return NULL;

	rcu_read_lock();
	ops = rcu_dereference(inet6_offloads[IPPROTO_ESP]);
	if (!ops || !ops->callbacks.gro_receive)
		goto out;

	ret = __xfrm6_udp_encap_rcv(sk, skb, false);
	if (ret)
		goto out;

	skb_push(skb, offset);
	NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;

	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
	rcu_read_unlock();

	return pp;

out:
	rcu_read_unlock();
	skb_push(skb, offset);
	NAPI_GRO_CB(skb)->same_flow = 0;
	NAPI_GRO_CB(skb)->flush = 1;

	return NULL;
}

int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
{
	return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
			     0, t);
}
EXPORT_SYMBOL(xfrm6_rcv_tnl);

int xfrm6_rcv(struct sk_buff *skb)
{
	return xfrm6_rcv_tnl(skb, NULL);
}
EXPORT_SYMBOL(xfrm6_rcv);
int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
		     xfrm_address_t *saddr, u8 proto)
{
	struct net *net = dev_net(skb->dev);
	struct xfrm_state *x = NULL;
	struct sec_path *sp;
	int i = 0;

	sp = secpath_set(skb);
	if (!sp) {
		XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
		goto drop;
	}

	if (1 + sp->len == XFRM_MAX_DEPTH) {
		XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
		goto drop;
	}

	for (i = 0; i < 3; i++) {
		xfrm_address_t *dst, *src;

		switch (i) {
		case 0:
			dst = daddr;
			src = saddr;
			break;
		case 1:
			/* lookup state with wild-card source address */
			dst = daddr;
			src = (xfrm_address_t *)&in6addr_any;
			break;
		default:
			/* lookup state with wild-card addresses */
			dst = (xfrm_address_t *)&in6addr_any;
			src = (xfrm_address_t *)&in6addr_any;
			break;
		}

		x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
		if (!x)
			continue;

		spin_lock(&x->lock);

		if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
		    likely(x->km.state == XFRM_STATE_VALID) &&
		    !xfrm_state_check_expire(x)) {
			spin_unlock(&x->lock);
			if (x->type->input(x, skb) > 0) {
				/* found a valid state */
				break;
			}
		} else
			spin_unlock(&x->lock);

		xfrm_state_put(x);
		x = NULL;
	}

	if (!x) {
		XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
		xfrm_audit_state_notfound_simple(skb, AF_INET6);
		goto drop;
	}

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

	spin_lock(&x->lock);

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

	spin_unlock(&x->lock);

	return 1;

drop:
	return -1;
}
EXPORT_SYMBOL(xfrm6_input_addr);
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* xfrm6_input.c: based on net/ipv4/xfrm4_input.c
	4	*
	5	* Authors:
	6	* Mitsuru KANDA @USAGI
67ba4152 IM	7	* Kazunori MIYAZAWA @USAGI
67ba4152 IM	8	* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
1da177e4 LT	9	* YOSHIFUJI Hideaki @USAGI
	10	* IPv6 support
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/string.h>
b05e1066 PM	15	#include <linux/netfilter.h>
b05e1066 PM	16	#include <linux/netfilter_ipv6.h>
1da177e4 LT	17	#include <net/ipv6.h>
1da177e4 LT	18	#include <net/xfrm.h>
221ddb72 SK	19	#include <net/protocol.h>
221ddb72 SK	20	#include <net/gro.h>
1da177e4	21
63c43787 ND	22	int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
63c43787 ND	23	struct ip6_tnl *t)
1da177e4	24	{
63c43787	25	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
2fcb45b6	26	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
716062fd HX	27	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
	28	return xfrm_input(skb, nexthdr, spi, 0);
	29	}
	30	EXPORT_SYMBOL(xfrm6_rcv_spi);
b05e1066	31
acf568ee HX	32	static int xfrm6_transport_finish2(struct net net, struct sock sk,
	33	struct sk_buff *skb)
	34	{
0146dca7 SD	35	if (xfrm_trans_queue(skb, ip6_rcv_finish)) {
	36	kfree_skb(skb);
	37	return NET_RX_DROP;
	38	}
	39
	40	return 0;
acf568ee HX	41	}
acf568ee HX	42
716062fd HX	43	int xfrm6_transport_finish(struct sk_buff *skb, int async)
716062fd HX	44	{
7785bba2	45	struct xfrm_offload *xo = xfrm_offload(skb);
e9cba694	46	int nhlen = skb->data - skb_network_header(skb);
7785bba2	47
60d5fcfb HX	48	skb_network_header(skb)[IP6CB(skb)->nhoff] =
	49	XFRM_MODE_SKB_CB(skb)->protocol;
	50
0883ae0e HX	51	#ifndef CONFIG_NETFILTER
	52	if (!async)
	53	return 1;
	54	#endif
	55
e9cba694	56	__skb_push(skb, nhlen);
7c88e21a	57	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
e9cba694	58	skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
b05e1066	59
7785bba2 SK	60	if (xo && (xo->flags & XFRM_GRO)) {
7785bba2 SK	61	skb_mac_header_rebuild(skb);
bfc0698b	62	skb_reset_transport_header(skb);
0146dca7	63	return 0;
7785bba2 SK	64	}
7785bba2 SK	65
29a26a56 EB	66	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
29a26a56 EB	67	dev_net(skb->dev), NULL, skb, skb->dev, NULL,
acf568ee	68	xfrm6_transport_finish2);
0146dca7 SD	69	return 0;
	70	}
	71
221ddb72	72	static int __xfrm6_udp_encap_rcv(struct sock sk, struct sk_buff skb, bool pull)
0146dca7 SD	73	{
	74	struct udp_sock *up = udp_sk(sk);
	75	struct udphdr *uh;
	76	struct ipv6hdr *ip6h;
	77	int len;
	78	int ip6hlen = sizeof(struct ipv6hdr);
0146dca7 SD	79	__u8 *udpdata;
0146dca7 SD	80	__be32 *udpdata32;
70a36f57	81	u16 encap_type;
0146dca7	82
70a36f57	83	encap_type = READ_ONCE(up->encap_type);
0146dca7 SD	84	/* if this is not encapsulated socket, then just return now */
	85	if (!encap_type)
	86	return 1;
	87
	88	/* If this is a paged skb, make sure we pull up
	89	* whatever data we need to look at. */
	90	len = skb->len - sizeof(struct udphdr);
	91	if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
	92	return 1;
	93
	94	/* Now we can get the pointers */
	95	uh = udp_hdr(skb);
	96	udpdata = (__u8 *)uh + sizeof(struct udphdr);
	97	udpdata32 = (__be32 *)udpdata;
	98
	99	switch (encap_type) {
	100	default:
	101	case UDP_ENCAP_ESPINUDP:
	102	/* Check if this is a keepalive packet. If so, eat it. */
	103	if (len == 1 && udpdata[0] == 0xff) {
221ddb72	104	return -EINVAL;
0146dca7 SD	105	} else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
	106	/* ESP Packet without Non-ESP header */
	107	len = sizeof(struct udphdr);
	108	} else
	109	/* Must be an IKE packet.. pass it through */
	110	return 1;
	111	break;
	112	case UDP_ENCAP_ESPINUDP_NON_IKE:
	113	/* Check if this is a keepalive packet. If so, eat it. */
	114	if (len == 1 && udpdata[0] == 0xff) {
221ddb72	115	return -EINVAL;
0146dca7 SD	116	} else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
	117	udpdata32[0] == 0 && udpdata32[1] == 0) {
	118
	119	/* ESP Packet with Non-IKE marker */
	120	len = sizeof(struct udphdr) + 2 * sizeof(u32);
	121	} else
	122	/* Must be an IKE packet.. pass it through */
	123	return 1;
	124	break;
	125	}
	126
	127	/* At this point we are sure that this is an ESPinUDP packet,
	128	* so we need to remove 'len' bytes from the packet (the UDP
	129	* header and optional ESP marker bytes) and then modify the
	130	* protocol to ESP, and then call into the transform receiver.
	131	*/
	132	if (skb_unclone(skb, GFP_ATOMIC))
221ddb72	133	return -EINVAL;
0146dca7 SD	134
	135	/* Now we can update and verify the packet length... */
	136	ip6h = ipv6_hdr(skb);
	137	ip6h->payload_len = htons(ntohs(ip6h->payload_len) - len);
	138	if (skb->len < ip6hlen + len) {
	139	/* packet is too small!?! */
221ddb72	140	return -EINVAL;
0146dca7 SD	141	}
	142
	143	/* pull the data buffer up to the ESP header and set the
	144	* transport header to point to ESP. Keep UDP on the stack
	145	* for later.
	146	*/
221ddb72 SK	147	if (pull) {
	148	__skb_pull(skb, len);
	149	skb_reset_transport_header(skb);
	150	} else {
	151	skb_set_transport_header(skb, len);
	152	}
0146dca7 SD	153
0146dca7 SD	154	/* process ESP */
0146dca7	155	return 0;
1da177e4 LT	156	}
1da177e4 LT	157
221ddb72 SK	158	/* If it's a keepalive packet, then just eat it.
	159	* If it's an encapsulated packet, then pass it to the
	160	* IPsec xfrm input.
	161	* Returns 0 if skb passed to xfrm or was dropped.
	162	* Returns >0 if skb should be passed to UDP.
	163	* Returns <0 if skb should be resubmitted (-ret is protocol)
	164	*/
	165	int xfrm6_udp_encap_rcv(struct sock sk, struct sk_buff skb)
	166	{
	167	int ret;
	168
53a5b4f2 SK	169	if (skb->protocol == htons(ETH_P_IP))
	170	return xfrm4_udp_encap_rcv(sk, skb);
	171
221ddb72 SK	172	ret = __xfrm6_udp_encap_rcv(sk, skb, true);
	173	if (!ret)
	174	return xfrm6_rcv_encap(skb, IPPROTO_ESP, 0,
	175	udp_sk(sk)->encap_type);
	176
	177	if (ret < 0) {
	178	kfree_skb(skb);
	179	return 0;
	180	}
	181
	182	return ret;
	183	}
	184
	185	struct sk_buff xfrm6_gro_udp_encap_rcv(struct sock sk, struct list_head *head,
	186	struct sk_buff *skb)
	187	{
	188	int offset = skb_gro_offset(skb);
	189	const struct net_offload *ops;
	190	struct sk_buff *pp = NULL;
	191	int ret;
	192
53a5b4f2 SK	193	if (skb->protocol == htons(ETH_P_IP))
	194	return xfrm4_gro_udp_encap_rcv(sk, head, skb);
	195
221ddb72 SK	196	offset = offset - sizeof(struct udphdr);
	197
	198	if (!pskb_pull(skb, offset))
	199	return NULL;
	200
	201	rcu_read_lock();
	202	ops = rcu_dereference(inet6_offloads[IPPROTO_ESP]);
	203	if (!ops \|\| !ops->callbacks.gro_receive)
	204	goto out;
	205
	206	ret = __xfrm6_udp_encap_rcv(sk, skb, false);
	207	if (ret)
	208	goto out;
	209
	210	skb_push(skb, offset);
	211	NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;
	212
	213	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
	214	rcu_read_unlock();
	215
	216	return pp;
	217
	218	out:
	219	rcu_read_unlock();
	220	skb_push(skb, offset);
	221	NAPI_GRO_CB(skb)->same_flow = 0;
	222	NAPI_GRO_CB(skb)->flush = 1;
	223
	224	return NULL;
	225	}
	226
63c43787	227	int xfrm6_rcv_tnl(struct sk_buff skb, struct ip6_tnl t)
1da177e4	228	{
33b5ecb8	229	return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
63c43787	230	0, t);
1da177e4	231	}
63c43787	232	EXPORT_SYMBOL(xfrm6_rcv_tnl);
7159039a	233
63c43787 ND	234	int xfrm6_rcv(struct sk_buff *skb)
	235	{
	236	return xfrm6_rcv_tnl(skb, NULL);
	237	}
	238	EXPORT_SYMBOL(xfrm6_rcv);
fbd9a5b4 MN	239	int xfrm6_input_addr(struct sk_buff skb, xfrm_address_t daddr,
	240	xfrm_address_t *saddr, u8 proto)
	241	{
59c9940e	242	struct net *net = dev_net(skb->dev);
1ab1457c	243	struct xfrm_state *x = NULL;
0ca64da1	244	struct sec_path *sp;
fbd9a5b4 MN	245	int i = 0;
fbd9a5b4 MN	246
0ca64da1 FW	247	sp = secpath_set(skb);
0ca64da1 FW	248	if (!sp) {
b0fcee82 SK	249	XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
b0fcee82 SK	250	goto drop;
9473e1f6 MN	251	}
9473e1f6 MN	252
0ca64da1	253	if (1 + sp->len == XFRM_MAX_DEPTH) {
59c9940e	254	XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
9473e1f6 MN	255	goto drop;
	256	}
	257
fbd9a5b4 MN	258	for (i = 0; i < 3; i++) {
fbd9a5b4 MN	259	xfrm_address_t dst, src;
a002c6fd	260
fbd9a5b4 MN	261	switch (i) {
	262	case 0:
	263	dst = daddr;
	264	src = saddr;
	265	break;
	266	case 1:
	267	/* lookup state with wild-card source address */
fbd9a5b4	268	dst = daddr;
a002c6fd	269	src = (xfrm_address_t *)&in6addr_any;
fbd9a5b4	270	break;
fbd9a5b4	271	default:
1ab1457c	272	/* lookup state with wild-card addresses */
a002c6fd YH	273	dst = (xfrm_address_t *)&in6addr_any;
a002c6fd YH	274	src = (xfrm_address_t *)&in6addr_any;
fbd9a5b4	275	break;
1ab1457c	276	}
fbd9a5b4	277
bd55775c	278	x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
fbd9a5b4 MN	279	if (!x)
	280	continue;
	281
	282	spin_lock(&x->lock);
	283
a002c6fd YH	284	if ((!i \|\| (x->props.flags & XFRM_STATE_WILDRECV)) &&
	285	likely(x->km.state == XFRM_STATE_VALID) &&
	286	!xfrm_state_check_expire(x)) {
fbd9a5b4	287	spin_unlock(&x->lock);
a002c6fd YH	288	if (x->type->input(x, skb) > 0) {
	289	/* found a valid state */
	290	break;
	291	}
	292	} else
fbd9a5b4	293	spin_unlock(&x->lock);
fbd9a5b4	294
a002c6fd YH	295	xfrm_state_put(x);
a002c6fd YH	296	x = NULL;
fbd9a5b4 MN	297	}
fbd9a5b4 MN	298
9473e1f6	299	if (!x) {
59c9940e	300	XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
afeb14b4	301	xfrm_audit_state_notfound_simple(skb, AF_INET6);
fbd9a5b4	302	goto drop;
fbd9a5b4 MN	303	}
fbd9a5b4 MN	304
2294be0f	305	sp->xvec[sp->len++] = x;
9473e1f6 MN	306
9473e1f6 MN	307	spin_lock(&x->lock);
fbd9a5b4	308
9473e1f6 MN	309	x->curlft.bytes += skb->len;
	310	x->curlft.packets++;
	311
	312	spin_unlock(&x->lock);
fbd9a5b4 MN	313
fbd9a5b4 MN	314	return 1;
9473e1f6	315
fbd9a5b4	316	drop:
fbd9a5b4 MN	317	return -1;
fbd9a5b4 MN	318	}
7159039a	319	EXPORT_SYMBOL(xfrm6_input_addr);