[thirdparty/linux.git] / net / ipv4 / esp4_offload.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * IPV4 GSO/GRO offload support
 * Linux INET implementation
 *
 * Copyright (C) 2016 secunet Security Networks AG
 * Author: Steffen Klassert <steffen.klassert@secunet.com>
 *
 * ESP GRO support
 */

#include <linux/skbuff.h>
#include <linux/init.h>
#include <net/protocol.h>
#include <crypto/aead.h>
#include <crypto/authenc.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/esp.h>
#include <linux/scatterlist.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <net/udp.h>

static struct sk_buff *esp4_gro_receive(struct list_head *head,
					struct sk_buff *skb)
{
	int offset = skb_gro_offset(skb);
	struct xfrm_offload *xo;
	struct xfrm_state *x;
	__be32 seq;
	__be32 spi;
	int err;

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

	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
		goto out;

	xo = xfrm_offload(skb);
	if (!xo || !(xo->flags & CRYPTO_DONE)) {
		struct sec_path *sp = secpath_set(skb);

		if (!sp)
			goto out;

		if (sp->len == XFRM_MAX_DEPTH)
			goto out_reset;

		x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
				      (xfrm_address_t *)&ip_hdr(skb)->daddr,
				      spi, IPPROTO_ESP, AF_INET);
		if (!x)
			goto out_reset;

		skb->mark = xfrm_smark_get(skb->mark, x);

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

		xo = xfrm_offload(skb);
		if (!xo)
			goto out_reset;
	}

	xo->flags |= XFRM_GRO;

	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
	XFRM_SPI_SKB_CB(skb)->seq = seq;

	/* We don't need to handle errors from xfrm_input, it does all
	 * the error handling and frees the resources on error. */
	xfrm_input(skb, IPPROTO_ESP, spi, -2);

	return ERR_PTR(-EINPROGRESS);
out_reset:
	secpath_reset(skb);
out:
	skb_push(skb, offset);
	NAPI_GRO_CB(skb)->same_flow = 0;
	NAPI_GRO_CB(skb)->flush = 1;

	return NULL;
}

static void esp4_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ip_esp_hdr *esph;
	struct iphdr *iph = ip_hdr(skb);
	struct xfrm_offload *xo = xfrm_offload(skb);
	int proto = iph->protocol;

	skb_push(skb, -skb_network_offset(skb));
	esph = ip_esp_hdr(skb);
	*skb_mac_header(skb) = IPPROTO_ESP;

	esph->spi = x->id.spi;
	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);

	xo->proto = proto;
}

static struct sk_buff *xfrm4_tunnel_gso_segment(struct xfrm_state *x,
						struct sk_buff *skb,
						netdev_features_t features)
{
	__skb_push(skb, skb->mac_len);
	return skb_mac_gso_segment(skb, features);
}

static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
						   struct sk_buff *skb,
						   netdev_features_t features)
{
	const struct net_offload *ops;
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct xfrm_offload *xo = xfrm_offload(skb);

	skb->transport_header += x->props.header_len;
	ops = rcu_dereference(inet_offloads[xo->proto]);
	if (likely(ops && ops->callbacks.gso_segment))
		segs = ops->callbacks.gso_segment(skb, features);

	return segs;
}

static struct sk_buff *xfrm4_beet_gso_segment(struct xfrm_state *x,
					      struct sk_buff *skb,
					      netdev_features_t features)
{
	struct xfrm_offload *xo = xfrm_offload(skb);
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	const struct net_offload *ops;
	u8 proto = xo->proto;

	skb->transport_header += x->props.header_len;

	if (x->sel.family != AF_INET6) {
		if (proto == IPPROTO_BEETPH) {
			struct ip_beet_phdr *ph =
				(struct ip_beet_phdr *)skb->data;

			skb->transport_header += ph->hdrlen * 8;
			proto = ph->nexthdr;
		} else {
			skb->transport_header -= IPV4_BEET_PHMAXLEN;
		}
	} else {
		__be16 frag;

		skb->transport_header +=
			ipv6_skip_exthdr(skb, 0, &proto, &frag);
		if (proto == IPPROTO_TCP)
			skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
	}

	__skb_pull(skb, skb_transport_offset(skb));
	ops = rcu_dereference(inet_offloads[proto]);
	if (likely(ops && ops->callbacks.gso_segment))
		segs = ops->callbacks.gso_segment(skb, features);

	return segs;
}

static struct sk_buff *xfrm4_outer_mode_gso_segment(struct xfrm_state *x,
						    struct sk_buff *skb,
						    netdev_features_t features)
{
	switch (x->outer_mode.encap) {
	case XFRM_MODE_TUNNEL:
		return xfrm4_tunnel_gso_segment(x, skb, features);
	case XFRM_MODE_TRANSPORT:
		return xfrm4_transport_gso_segment(x, skb, features);
	case XFRM_MODE_BEET:
		return xfrm4_beet_gso_segment(x, skb, features);
	}

	return ERR_PTR(-EOPNOTSUPP);
}

static struct sk_buff *esp4_gso_segment(struct sk_buff *skb,
				        netdev_features_t features)
{
	struct xfrm_state *x;
	struct ip_esp_hdr *esph;
	struct crypto_aead *aead;
	netdev_features_t esp_features = features;
	struct xfrm_offload *xo = xfrm_offload(skb);
	struct sec_path *sp;

	if (!xo)
		return ERR_PTR(-EINVAL);

	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
		return ERR_PTR(-EINVAL);

	sp = skb_sec_path(skb);
	x = sp->xvec[sp->len - 1];
	aead = x->data;
	esph = ip_esp_hdr(skb);

	if (esph->spi != x->id.spi)
		return ERR_PTR(-EINVAL);

	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
		return ERR_PTR(-EINVAL);

	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));

	skb->encap_hdr_csum = 1;

	if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) &&
	     !(features & NETIF_F_HW_ESP)) || x->xso.dev != skb->dev)
		esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
	else if (!(features & NETIF_F_HW_ESP_TX_CSUM) &&
		 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM))
		esp_features = features & ~NETIF_F_CSUM_MASK;

	xo->flags |= XFRM_GSO_SEGMENT;

	return xfrm4_outer_mode_gso_segment(x, skb, esp_features);
}

static int esp_input_tail(struct xfrm_state *x, struct sk_buff *skb)
{
	struct crypto_aead *aead = x->data;
	struct xfrm_offload *xo = xfrm_offload(skb);

	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
		return -EINVAL;

	if (!(xo->flags & CRYPTO_DONE))
		skb->ip_summed = CHECKSUM_NONE;

	return esp_input_done2(skb, 0);
}

static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_t features)
{
	int err;
	int alen;
	int blksize;
	struct xfrm_offload *xo;
	struct ip_esp_hdr *esph;
	struct crypto_aead *aead;
	struct esp_info esp;
	bool hw_offload = true;
	__u32 seq;

	esp.inplace = true;

	xo = xfrm_offload(skb);

	if (!xo)
		return -EINVAL;

	if ((!(features & NETIF_F_HW_ESP) &&
	     !(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) ||
	    x->xso.dev != skb->dev) {
		xo->flags |= CRYPTO_FALLBACK;
		hw_offload = false;
	}

	esp.proto = xo->proto;

	/* skb is pure payload to encrypt */

	aead = x->data;
	alen = crypto_aead_authsize(aead);

	esp.tfclen = 0;
	/* XXX: Add support for tfc padding here. */

	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	esp.plen = esp.clen - skb->len - esp.tfclen;
	esp.tailen = esp.tfclen + esp.plen + alen;

	esp.esph = ip_esp_hdr(skb);


	if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
		esp.nfrags = esp_output_head(x, skb, &esp);
		if (esp.nfrags < 0)
			return esp.nfrags;
	}

	seq = xo->seq.low;

	esph = esp.esph;
	esph->spi = x->id.spi;

	skb_push(skb, -skb_network_offset(skb));

	if (xo->flags & XFRM_GSO_SEGMENT) {
		esph->seq_no = htonl(seq);

		if (!skb_is_gso(skb))
			xo->seq.low++;
		else
			xo->seq.low += skb_shinfo(skb)->gso_segs;
	}

	esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));

	ip_hdr(skb)->tot_len = htons(skb->len);
	ip_send_check(ip_hdr(skb));

	if (hw_offload)
		return 0;

	err = esp_output_tail(x, skb, &esp);
	if (err)
		return err;

	secpath_reset(skb);

	return 0;
}

static const struct net_offload esp4_offload = {
	.callbacks = {
		.gro_receive = esp4_gro_receive,
		.gso_segment = esp4_gso_segment,
	},
};

static const struct xfrm_type_offload esp_type_offload = {
	.description	= "ESP4 OFFLOAD",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_ESP,
	.input_tail	= esp_input_tail,
	.xmit		= esp_xmit,
	.encap		= esp4_gso_encap,
};

static int __init esp4_offload_init(void)
{
	if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
		pr_info("%s: can't add xfrm type offload\n", __func__);
		return -EAGAIN;
	}

	return inet_add_offload(&esp4_offload, IPPROTO_ESP);
}

static void __exit esp4_offload_exit(void)
{
	xfrm_unregister_type_offload(&esp_type_offload, AF_INET);
	inet_del_offload(&esp4_offload, IPPROTO_ESP);
}

module_init(esp4_offload_init);
module_exit(esp4_offload_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);
Commit	Line	Data
75a6faf6	1	// SPDX-License-Identifier: GPL-2.0-only
7785bba2 SK	2	/*
	3	* IPV4 GSO/GRO offload support
	4	* Linux INET implementation
	5	*
	6	* Copyright (C) 2016 secunet Security Networks AG
	7	* Author: Steffen Klassert <steffen.klassert@secunet.com>
	8	*
7785bba2 SK	9	* ESP GRO support
	10	*/
	11
	12	#include <linux/skbuff.h>
	13	#include <linux/init.h>
	14	#include <net/protocol.h>
	15	#include <crypto/aead.h>
	16	#include <crypto/authenc.h>
	17	#include <linux/err.h>
	18	#include <linux/module.h>
	19	#include <net/ip.h>
	20	#include <net/xfrm.h>
	21	#include <net/esp.h>
	22	#include <linux/scatterlist.h>
	23	#include <linux/kernel.h>
	24	#include <linux/slab.h>
	25	#include <linux/spinlock.h>
	26	#include <net/udp.h>
	27
d4546c25 DM	28	static struct sk_buff esp4_gro_receive(struct list_head head,
d4546c25 DM	29	struct sk_buff *skb)
7785bba2 SK	30	{
	31	int offset = skb_gro_offset(skb);
	32	struct xfrm_offload *xo;
	33	struct xfrm_state *x;
	34	__be32 seq;
	35	__be32 spi;
	36	int err;
	37
374d1b5a SK	38	if (!pskb_pull(skb, offset))
374d1b5a SK	39	return NULL;
7785bba2 SK	40
	41	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
	42	goto out;
	43
bcd1f8a4 SK	44	xo = xfrm_offload(skb);
bcd1f8a4 SK	45	if (!xo \|\| !(xo->flags & CRYPTO_DONE)) {
0ca64da1 FW	46	struct sec_path *sp = secpath_set(skb);
	47
	48	if (!sp)
bcd1f8a4	49	goto out;
7785bba2	50
0ca64da1	51	if (sp->len == XFRM_MAX_DEPTH)
6ed69184	52	goto out_reset;
7785bba2	53
bcd1f8a4 SK	54	x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
	55	(xfrm_address_t *)&ip_hdr(skb)->daddr,
	56	spi, IPPROTO_ESP, AF_INET);
	57	if (!x)
6ed69184	58	goto out_reset;
7785bba2	59
4e4362d2 UW	60	skb->mark = xfrm_smark_get(skb->mark, x);
4e4362d2 UW	61
0ca64da1 FW	62	sp->xvec[sp->len++] = x;
0ca64da1 FW	63	sp->olen++;
7785bba2	64
bcd1f8a4	65	xo = xfrm_offload(skb);
db87668a	66	if (!xo)
6ed69184	67	goto out_reset;
7785bba2	68	}
bcd1f8a4	69
7785bba2 SK	70	xo->flags \|= XFRM_GRO;
	71
	72	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
	73	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
	74	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
	75	XFRM_SPI_SKB_CB(skb)->seq = seq;
	76
	77	/* We don't need to handle errors from xfrm_input, it does all
	78	* the error handling and frees the resources on error. */
	79	xfrm_input(skb, IPPROTO_ESP, spi, -2);
	80
	81	return ERR_PTR(-EINPROGRESS);
6ed69184 MJ	82	out_reset:
6ed69184 MJ	83	secpath_reset(skb);
7785bba2 SK	84	out:
	85	skb_push(skb, offset);
	86	NAPI_GRO_CB(skb)->same_flow = 0;
	87	NAPI_GRO_CB(skb)->flush = 1;
	88
	89	return NULL;
	90	}
	91
7862b405 SK	92	static void esp4_gso_encap(struct xfrm_state x, struct sk_buff skb)
	93	{
	94	struct ip_esp_hdr *esph;
	95	struct iphdr *iph = ip_hdr(skb);
	96	struct xfrm_offload *xo = xfrm_offload(skb);
	97	int proto = iph->protocol;
	98
	99	skb_push(skb, -skb_network_offset(skb));
	100	esph = ip_esp_hdr(skb);
	101	*skb_mac_header(skb) = IPPROTO_ESP;
	102
	103	esph->spi = x->id.spi;
	104	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
	105
	106	xo->proto = proto;
	107	}
	108
7613b92b FW	109	static struct sk_buff xfrm4_tunnel_gso_segment(struct xfrm_state x,
	110	struct sk_buff *skb,
	111	netdev_features_t features)
	112	{
	113	__skb_push(skb, skb->mac_len);
	114	return skb_mac_gso_segment(skb, features);
	115	}
	116
	117	static struct sk_buff xfrm4_transport_gso_segment(struct xfrm_state x,
	118	struct sk_buff *skb,
	119	netdev_features_t features)
	120	{
	121	const struct net_offload *ops;
	122	struct sk_buff *segs = ERR_PTR(-EINVAL);
	123	struct xfrm_offload *xo = xfrm_offload(skb);
	124
	125	skb->transport_header += x->props.header_len;
	126	ops = rcu_dereference(inet_offloads[xo->proto]);
	127	if (likely(ops && ops->callbacks.gso_segment))
	128	segs = ops->callbacks.gso_segment(skb, features);
	129
	130	return segs;
	131	}
	132
384a46ea XL	133	static struct sk_buff xfrm4_beet_gso_segment(struct xfrm_state x,
	134	struct sk_buff *skb,
	135	netdev_features_t features)
	136	{
	137	struct xfrm_offload *xo = xfrm_offload(skb);
	138	struct sk_buff *segs = ERR_PTR(-EINVAL);
	139	const struct net_offload *ops;
6f297068	140	u8 proto = xo->proto;
384a46ea XL	141
	142	skb->transport_header += x->props.header_len;
	143
3ffb93ba XL	144	if (x->sel.family != AF_INET6) {
	145	if (proto == IPPROTO_BEETPH) {
	146	struct ip_beet_phdr *ph =
	147	(struct ip_beet_phdr *)skb->data;
	148
	149	skb->transport_header += ph->hdrlen * 8;
	150	proto = ph->nexthdr;
	151	} else {
	152	skb->transport_header -= IPV4_BEET_PHMAXLEN;
	153	}
	154	} else {
6f297068 XL	155	__be16 frag;
	156
	157	skb->transport_header +=
	158	ipv6_skip_exthdr(skb, 0, &proto, &frag);
	159	if (proto == IPPROTO_TCP)
	160	skb_shinfo(skb)->gso_type \|= SKB_GSO_TCPV4;
384a46ea XL	161	}
	162
	163	__skb_pull(skb, skb_transport_offset(skb));
	164	ops = rcu_dereference(inet_offloads[proto]);
	165	if (likely(ops && ops->callbacks.gso_segment))
	166	segs = ops->callbacks.gso_segment(skb, features);
	167
	168	return segs;
	169	}
	170
7613b92b FW	171	static struct sk_buff xfrm4_outer_mode_gso_segment(struct xfrm_state x,
	172	struct sk_buff *skb,
	173	netdev_features_t features)
	174	{
c9500d7b	175	switch (x->outer_mode.encap) {
7613b92b FW	176	case XFRM_MODE_TUNNEL:
	177	return xfrm4_tunnel_gso_segment(x, skb, features);
	178	case XFRM_MODE_TRANSPORT:
	179	return xfrm4_transport_gso_segment(x, skb, features);
384a46ea XL	180	case XFRM_MODE_BEET:
384a46ea XL	181	return xfrm4_beet_gso_segment(x, skb, features);
7613b92b FW	182	}
	183
	184	return ERR_PTR(-EOPNOTSUPP);
	185	}
	186
7862b405 SK	187	static struct sk_buff esp4_gso_segment(struct sk_buff skb,
	188	netdev_features_t features)
	189	{
7862b405 SK	190	struct xfrm_state *x;
	191	struct ip_esp_hdr *esph;
	192	struct crypto_aead *aead;
7862b405 SK	193	netdev_features_t esp_features = features;
7862b405 SK	194	struct xfrm_offload *xo = xfrm_offload(skb);
2294be0f	195	struct sec_path *sp;
7862b405 SK	196
7862b405 SK	197	if (!xo)
3dca3f38	198	return ERR_PTR(-EINVAL);
7862b405	199
121d57af	200	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
5ca11440	201	return ERR_PTR(-EINVAL);
7862b405	202
2294be0f FW	203	sp = skb_sec_path(skb);
2294be0f FW	204	x = sp->xvec[sp->len - 1];
7862b405 SK	205	aead = x->data;
	206	esph = ip_esp_hdr(skb);
	207
	208	if (esph->spi != x->id.spi)
3dca3f38	209	return ERR_PTR(-EINVAL);
7862b405 SK	210
7862b405 SK	211	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
3dca3f38	212	return ERR_PTR(-EINVAL);
7862b405 SK	213
	214	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
	215
	216	skb->encap_hdr_csum = 1;
	217
65fd2c2a BP	218	if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) &&
65fd2c2a BP	219	!(features & NETIF_F_HW_ESP)) \|\| x->xso.dev != skb->dev)
7862b405	220	esp_features = features & ~(NETIF_F_SG \| NETIF_F_CSUM_MASK);
65fd2c2a BP	221	else if (!(features & NETIF_F_HW_ESP_TX_CSUM) &&
65fd2c2a BP	222	!(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM))
5211fcfb	223	esp_features = features & ~NETIF_F_CSUM_MASK;
7862b405	224
3dca3f38	225	xo->flags \|= XFRM_GSO_SEGMENT;
7862b405	226
7613b92b	227	return xfrm4_outer_mode_gso_segment(x, skb, esp_features);
7862b405 SK	228	}
7862b405 SK	229
fca11ebd SK	230	static int esp_input_tail(struct xfrm_state x, struct sk_buff skb)
	231	{
	232	struct crypto_aead *aead = x->data;
ec9567a9	233	struct xfrm_offload *xo = xfrm_offload(skb);
fca11ebd SK	234
	235	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
	236	return -EINVAL;
	237
ec9567a9 IT	238	if (!(xo->flags & CRYPTO_DONE))
ec9567a9 IT	239	skb->ip_summed = CHECKSUM_NONE;
fca11ebd SK	240
	241	return esp_input_done2(skb, 0);
	242	}
	243
	244	static int esp_xmit(struct xfrm_state x, struct sk_buff skb, netdev_features_t features)
	245	{
	246	int err;
	247	int alen;
	248	int blksize;
	249	struct xfrm_offload *xo;
	250	struct ip_esp_hdr *esph;
	251	struct crypto_aead *aead;
	252	struct esp_info esp;
	253	bool hw_offload = true;
3dca3f38	254	__u32 seq;
fca11ebd SK	255
	256	esp.inplace = true;
	257
	258	xo = xfrm_offload(skb);
	259
	260	if (!xo)
	261	return -EINVAL;
	262
65fd2c2a BP	263	if ((!(features & NETIF_F_HW_ESP) &&
	264	!(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) \|\|
	265	x->xso.dev != skb->dev) {
fca11ebd SK	266	xo->flags \|= CRYPTO_FALLBACK;
	267	hw_offload = false;
	268	}
	269
	270	esp.proto = xo->proto;
	271
	272	/* skb is pure payload to encrypt */
	273
	274	aead = x->data;
	275	alen = crypto_aead_authsize(aead);
	276
	277	esp.tfclen = 0;
	278	/* XXX: Add support for tfc padding here. */
	279
	280	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	281	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	282	esp.plen = esp.clen - skb->len - esp.tfclen;
	283	esp.tailen = esp.tfclen + esp.plen + alen;
	284
	285	esp.esph = ip_esp_hdr(skb);
	286
	287
	288	if (!hw_offload \|\| (hw_offload && !skb_is_gso(skb))) {
	289	esp.nfrags = esp_output_head(x, skb, &esp);
	290	if (esp.nfrags < 0)
	291	return esp.nfrags;
	292	}
	293
3dca3f38 SK	294	seq = xo->seq.low;
3dca3f38 SK	295
fca11ebd SK	296	esph = esp.esph;
	297	esph->spi = x->id.spi;
	298
	299	skb_push(skb, -skb_network_offset(skb));
	300
	301	if (xo->flags & XFRM_GSO_SEGMENT) {
3dca3f38 SK	302	esph->seq_no = htonl(seq);
	303
	304	if (!skb_is_gso(skb))
	305	xo->seq.low++;
	306	else
	307	xo->seq.low += skb_shinfo(skb)->gso_segs;
fca11ebd SK	308	}
fca11ebd SK	309
3dca3f38 SK	310	esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
	311
	312	ip_hdr(skb)->tot_len = htons(skb->len);
	313	ip_send_check(ip_hdr(skb));
	314
fca11ebd SK	315	if (hw_offload)
	316	return 0;
	317
fca11ebd	318	err = esp_output_tail(x, skb, &esp);
4ff0308f	319	if (err)
fca11ebd SK	320	return err;
	321
	322	secpath_reset(skb);
	323
	324	return 0;
	325	}
	326
7785bba2 SK	327	static const struct net_offload esp4_offload = {
	328	.callbacks = {
	329	.gro_receive = esp4_gro_receive,
7862b405	330	.gso_segment = esp4_gso_segment,
7785bba2 SK	331	},
	332	};
	333
fca11ebd SK	334	static const struct xfrm_type_offload esp_type_offload = {
	335	.description = "ESP4 OFFLOAD",
	336	.owner = THIS_MODULE,
	337	.proto = IPPROTO_ESP,
	338	.input_tail = esp_input_tail,
	339	.xmit = esp_xmit,
7862b405	340	.encap = esp4_gso_encap,
fca11ebd SK	341	};
fca11ebd SK	342
7785bba2 SK	343	static int __init esp4_offload_init(void)
7785bba2 SK	344	{
fca11ebd SK	345	if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
	346	pr_info("%s: can't add xfrm type offload\n", __func__);
	347	return -EAGAIN;
	348	}
	349
7785bba2 SK	350	return inet_add_offload(&esp4_offload, IPPROTO_ESP);
	351	}
	352
	353	static void __exit esp4_offload_exit(void)
	354	{
4f518e80	355	xfrm_unregister_type_offload(&esp_type_offload, AF_INET);
7785bba2 SK	356	inet_del_offload(&esp4_offload, IPPROTO_ESP);
	357	}
	358
	359	module_init(esp4_offload_init);
	360	module_exit(esp4_offload_exit);
	361	MODULE_LICENSE("GPL");
	362	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
ffdb5211	363	MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);