[linux-block.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/gro.h>
#include <net/gso.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;
	int encap_type = 0;
	__be32 seq;
	__be32 spi;

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

	if (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 (unlikely(x && x->dir && x->dir != XFRM_SA_DIR_IN)) {
			/* non-offload path will record the error and audit log */
			xfrm_state_put(x);
			x = NULL;
		}

		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;

	if (NAPI_GRO_CB(skb)->proto == IPPROTO_UDP)
		encap_type = UDP_ENCAP_ESPINUDP;

	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, encap_type);

	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)
{
	__be16 type = x->inner_mode.family == AF_INET6 ? htons(ETH_P_IPV6)
						       : htons(ETH_P_IP);

	return skb_eth_gso_segment(skb, features, type);
}

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;
	}

	if (proto == IPPROTO_IPV6)
		skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;

	__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 |
					    NETIF_F_SCTP_CRC);
	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 |
					    NETIF_F_SCTP_CRC);

	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;
	int encap_type = 0;

	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 (x->encap)
		encap_type = x->encap->encap_type;

	if (!hw_offload || !skb_is_gso(skb) || (hw_offload && encap_type == UDP_ENCAP_ESPINUDP)) {
		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;
	}

	if (xo->seq.low < seq)
		xo->seq.hi++;

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

	if (hw_offload && encap_type == UDP_ENCAP_ESPINUDP) {
		/* In the XFRM stack, the encapsulation protocol is set to iphdr->protocol by
		 * setting *skb_mac_header(skb) (see esp_output_udp_encap()) where skb->mac_header
		 * points to iphdr->protocol (see xfrm4_tunnel_encap_add()).
		 * However, in esp_xmit(), skb->mac_header doesn't point to iphdr->protocol.
		 * Therefore, the protocol field needs to be corrected.
		 */
		ip_hdr(skb)->protocol = IPPROTO_UDP;

		esph->seq_no = htonl(seq);
	}

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

	if (hw_offload) {
		if (!skb_ext_add(skb, SKB_EXT_SEC_PATH))
			return -ENOMEM;

		xo = xfrm_offload(skb);
		if (!xo)
			return -EINVAL;

		xo->flags |= XFRM_XMIT;
		return 0;
	}

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

	secpath_reset(skb);

	if (skb_needs_linearize(skb, skb->dev->features) &&
	    __skb_linearize(skb))
		return -ENOMEM;
	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 = {
	.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);
MODULE_DESCRIPTION("IPV4 GSO/GRO offload support");
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>
4721031c	19	#include <net/gro.h>
d457a0e3	20	#include <net/gso.h>
7785bba2 SK	21	#include <net/ip.h>
	22	#include <net/xfrm.h>
	23	#include <net/esp.h>
	24	#include <linux/scatterlist.h>
	25	#include <linux/kernel.h>
	26	#include <linux/slab.h>
	27	#include <linux/spinlock.h>
	28	#include <net/udp.h>
	29
d4546c25 DM	30	static struct sk_buff esp4_gro_receive(struct list_head head,
d4546c25 DM	31	struct sk_buff *skb)
7785bba2 SK	32	{
	33	int offset = skb_gro_offset(skb);
	34	struct xfrm_offload *xo;
	35	struct xfrm_state *x;
172bf009	36	int encap_type = 0;
7785bba2 SK	37	__be32 seq;
7785bba2 SK	38	__be32 spi;
7785bba2	39
374d1b5a SK	40	if (!pskb_pull(skb, offset))
374d1b5a SK	41	return NULL;
7785bba2	42
335a2a1f	43	if (xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq) != 0)
7785bba2 SK	44	goto out;
7785bba2 SK	45
bcd1f8a4 SK	46	xo = xfrm_offload(skb);
bcd1f8a4 SK	47	if (!xo \|\| !(xo->flags & CRYPTO_DONE)) {
0ca64da1 FW	48	struct sec_path *sp = secpath_set(skb);
	49
	50	if (!sp)
bcd1f8a4	51	goto out;
7785bba2	52
0ca64da1	53	if (sp->len == XFRM_MAX_DEPTH)
6ed69184	54	goto out_reset;
7785bba2	55
bcd1f8a4 SK	56	x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
	57	(xfrm_address_t *)&ip_hdr(skb)->daddr,
	58	spi, IPPROTO_ESP, AF_INET);
15f5fe9e AA	59
	60	if (unlikely(x && x->dir && x->dir != XFRM_SA_DIR_IN)) {
	61	/* non-offload path will record the error and audit log */
	62	xfrm_state_put(x);
	63	x = NULL;
	64	}
	65
bcd1f8a4	66	if (!x)
6ed69184	67	goto out_reset;
7785bba2	68
4e4362d2 UW	69	skb->mark = xfrm_smark_get(skb->mark, x);
4e4362d2 UW	70
0ca64da1 FW	71	sp->xvec[sp->len++] = x;
0ca64da1 FW	72	sp->olen++;
7785bba2	73
bcd1f8a4	74	xo = xfrm_offload(skb);
db87668a	75	if (!xo)
6ed69184	76	goto out_reset;
7785bba2	77	}
bcd1f8a4	78
7785bba2 SK	79	xo->flags \|= XFRM_GRO;
7785bba2 SK	80
172bf009 SK	81	if (NAPI_GRO_CB(skb)->proto == IPPROTO_UDP)
	82	encap_type = UDP_ENCAP_ESPINUDP;
	83
7785bba2 SK	84	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
	85	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
	86	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
	87	XFRM_SPI_SKB_CB(skb)->seq = seq;
	88
	89	/* We don't need to handle errors from xfrm_input, it does all
	90	* the error handling and frees the resources on error. */
172bf009	91	xfrm_input(skb, IPPROTO_ESP, spi, encap_type);
7785bba2 SK	92
7785bba2 SK	93	return ERR_PTR(-EINPROGRESS);
6ed69184 MJ	94	out_reset:
6ed69184 MJ	95	secpath_reset(skb);
7785bba2 SK	96	out:
	97	skb_push(skb, offset);
	98	NAPI_GRO_CB(skb)->same_flow = 0;
	99	NAPI_GRO_CB(skb)->flush = 1;
	100
	101	return NULL;
	102	}
	103
7862b405 SK	104	static void esp4_gso_encap(struct xfrm_state x, struct sk_buff skb)
	105	{
	106	struct ip_esp_hdr *esph;
	107	struct iphdr *iph = ip_hdr(skb);
	108	struct xfrm_offload *xo = xfrm_offload(skb);
	109	int proto = iph->protocol;
	110
	111	skb_push(skb, -skb_network_offset(skb));
	112	esph = ip_esp_hdr(skb);
	113	*skb_mac_header(skb) = IPPROTO_ESP;
	114
	115	esph->spi = x->id.spi;
	116	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
	117
	118	xo->proto = proto;
	119	}
	120
7613b92b FW	121	static struct sk_buff xfrm4_tunnel_gso_segment(struct xfrm_state x,
	122	struct sk_buff *skb,
	123	netdev_features_t features)
	124	{
26dbd66e SD	125	__be16 type = x->inner_mode.family == AF_INET6 ? htons(ETH_P_IPV6)
	126	: htons(ETH_P_IP);
	127
	128	return skb_eth_gso_segment(skb, features, type);
7613b92b FW	129	}
	130
	131	static struct sk_buff xfrm4_transport_gso_segment(struct xfrm_state x,
	132	struct sk_buff *skb,
	133	netdev_features_t features)
	134	{
	135	const struct net_offload *ops;
	136	struct sk_buff *segs = ERR_PTR(-EINVAL);
	137	struct xfrm_offload *xo = xfrm_offload(skb);
	138
	139	skb->transport_header += x->props.header_len;
	140	ops = rcu_dereference(inet_offloads[xo->proto]);
	141	if (likely(ops && ops->callbacks.gso_segment))
	142	segs = ops->callbacks.gso_segment(skb, features);
	143
	144	return segs;
	145	}
	146
384a46ea XL	147	static struct sk_buff xfrm4_beet_gso_segment(struct xfrm_state x,
	148	struct sk_buff *skb,
	149	netdev_features_t features)
	150	{
	151	struct xfrm_offload *xo = xfrm_offload(skb);
	152	struct sk_buff *segs = ERR_PTR(-EINVAL);
	153	const struct net_offload *ops;
6f297068	154	u8 proto = xo->proto;
384a46ea XL	155
	156	skb->transport_header += x->props.header_len;
	157
3ffb93ba XL	158	if (x->sel.family != AF_INET6) {
	159	if (proto == IPPROTO_BEETPH) {
	160	struct ip_beet_phdr *ph =
	161	(struct ip_beet_phdr *)skb->data;
	162
	163	skb->transport_header += ph->hdrlen * 8;
	164	proto = ph->nexthdr;
	165	} else {
	166	skb->transport_header -= IPV4_BEET_PHMAXLEN;
	167	}
	168	} else {
6f297068 XL	169	__be16 frag;
	170
	171	skb->transport_header +=
	172	ipv6_skip_exthdr(skb, 0, &proto, &frag);
	173	if (proto == IPPROTO_TCP)
	174	skb_shinfo(skb)->gso_type \|= SKB_GSO_TCPV4;
384a46ea XL	175	}
384a46ea XL	176
053c8fdf SK	177	if (proto == IPPROTO_IPV6)
	178	skb_shinfo(skb)->gso_type \|= SKB_GSO_IPXIP4;
	179
384a46ea XL	180	__skb_pull(skb, skb_transport_offset(skb));
	181	ops = rcu_dereference(inet_offloads[proto]);
	182	if (likely(ops && ops->callbacks.gso_segment))
	183	segs = ops->callbacks.gso_segment(skb, features);
	184
	185	return segs;
	186	}
	187
7613b92b FW	188	static struct sk_buff xfrm4_outer_mode_gso_segment(struct xfrm_state x,
	189	struct sk_buff *skb,
	190	netdev_features_t features)
	191	{
c9500d7b	192	switch (x->outer_mode.encap) {
7613b92b FW	193	case XFRM_MODE_TUNNEL:
	194	return xfrm4_tunnel_gso_segment(x, skb, features);
	195	case XFRM_MODE_TRANSPORT:
	196	return xfrm4_transport_gso_segment(x, skb, features);
384a46ea XL	197	case XFRM_MODE_BEET:
384a46ea XL	198	return xfrm4_beet_gso_segment(x, skb, features);
7613b92b FW	199	}
	200
	201	return ERR_PTR(-EOPNOTSUPP);
	202	}
	203
7862b405 SK	204	static struct sk_buff esp4_gso_segment(struct sk_buff skb,
	205	netdev_features_t features)
	206	{
7862b405 SK	207	struct xfrm_state *x;
	208	struct ip_esp_hdr *esph;
	209	struct crypto_aead *aead;
7862b405 SK	210	netdev_features_t esp_features = features;
7862b405 SK	211	struct xfrm_offload *xo = xfrm_offload(skb);
2294be0f	212	struct sec_path *sp;
7862b405 SK	213
7862b405 SK	214	if (!xo)
3dca3f38	215	return ERR_PTR(-EINVAL);
7862b405	216
121d57af	217	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
5ca11440	218	return ERR_PTR(-EINVAL);
7862b405	219
2294be0f FW	220	sp = skb_sec_path(skb);
2294be0f FW	221	x = sp->xvec[sp->len - 1];
7862b405 SK	222	aead = x->data;
	223	esph = ip_esp_hdr(skb);
	224
	225	if (esph->spi != x->id.spi)
3dca3f38	226	return ERR_PTR(-EINVAL);
7862b405 SK	227
7862b405 SK	228	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
3dca3f38	229	return ERR_PTR(-EINVAL);
7862b405 SK	230
	231	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
	232
	233	skb->encap_hdr_csum = 1;
	234
65fd2c2a BP	235	if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) &&
65fd2c2a BP	236	!(features & NETIF_F_HW_ESP)) \|\| x->xso.dev != skb->dev)
154deab6 XL	237	esp_features = features & ~(NETIF_F_SG \| NETIF_F_CSUM_MASK \|
154deab6 XL	238	NETIF_F_SCTP_CRC);
65fd2c2a BP	239	else if (!(features & NETIF_F_HW_ESP_TX_CSUM) &&
65fd2c2a BP	240	!(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM))
154deab6 XL	241	esp_features = features & ~(NETIF_F_CSUM_MASK \|
154deab6 XL	242	NETIF_F_SCTP_CRC);
7862b405	243
3dca3f38	244	xo->flags \|= XFRM_GSO_SEGMENT;
7862b405	245
7613b92b	246	return xfrm4_outer_mode_gso_segment(x, skb, esp_features);
7862b405 SK	247	}
7862b405 SK	248
fca11ebd SK	249	static int esp_input_tail(struct xfrm_state x, struct sk_buff skb)
	250	{
	251	struct crypto_aead *aead = x->data;
ec9567a9	252	struct xfrm_offload *xo = xfrm_offload(skb);
fca11ebd SK	253
	254	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
	255	return -EINVAL;
	256
ec9567a9 IT	257	if (!(xo->flags & CRYPTO_DONE))
ec9567a9 IT	258	skb->ip_summed = CHECKSUM_NONE;
fca11ebd SK	259
	260	return esp_input_done2(skb, 0);
	261	}
	262
	263	static int esp_xmit(struct xfrm_state x, struct sk_buff skb, netdev_features_t features)
	264	{
	265	int err;
	266	int alen;
	267	int blksize;
	268	struct xfrm_offload *xo;
	269	struct ip_esp_hdr *esph;
	270	struct crypto_aead *aead;
	271	struct esp_info esp;
	272	bool hw_offload = true;
3dca3f38	273	__u32 seq;
447bc4b1	274	int encap_type = 0;
fca11ebd SK	275
	276	esp.inplace = true;
	277
	278	xo = xfrm_offload(skb);
	279
	280	if (!xo)
	281	return -EINVAL;
	282
65fd2c2a BP	283	if ((!(features & NETIF_F_HW_ESP) &&
	284	!(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) \|\|
	285	x->xso.dev != skb->dev) {
fca11ebd SK	286	xo->flags \|= CRYPTO_FALLBACK;
	287	hw_offload = false;
	288	}
	289
	290	esp.proto = xo->proto;
	291
	292	/* skb is pure payload to encrypt */
	293
	294	aead = x->data;
	295	alen = crypto_aead_authsize(aead);
	296
	297	esp.tfclen = 0;
	298	/* XXX: Add support for tfc padding here. */
	299
	300	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	301	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	302	esp.plen = esp.clen - skb->len - esp.tfclen;
	303	esp.tailen = esp.tfclen + esp.plen + alen;
	304
	305	esp.esph = ip_esp_hdr(skb);
	306
447bc4b1 MY	307	if (x->encap)
447bc4b1 MY	308	encap_type = x->encap->encap_type;
fca11ebd	309
447bc4b1	310	if (!hw_offload \|\| !skb_is_gso(skb) \|\| (hw_offload && encap_type == UDP_ENCAP_ESPINUDP)) {
fca11ebd SK	311	esp.nfrags = esp_output_head(x, skb, &esp);
	312	if (esp.nfrags < 0)
	313	return esp.nfrags;
	314	}
	315
3dca3f38 SK	316	seq = xo->seq.low;
3dca3f38 SK	317
fca11ebd SK	318	esph = esp.esph;
	319	esph->spi = x->id.spi;
	320
	321	skb_push(skb, -skb_network_offset(skb));
	322
	323	if (xo->flags & XFRM_GSO_SEGMENT) {
3dca3f38 SK	324	esph->seq_no = htonl(seq);
	325
	326	if (!skb_is_gso(skb))
	327	xo->seq.low++;
	328	else
	329	xo->seq.low += skb_shinfo(skb)->gso_segs;
fca11ebd SK	330	}
fca11ebd SK	331
4b549ccc CL	332	if (xo->seq.low < seq)
	333	xo->seq.hi++;
	334
3dca3f38 SK	335	esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
3dca3f38 SK	336
447bc4b1 MY	337	if (hw_offload && encap_type == UDP_ENCAP_ESPINUDP) {
	338	/* In the XFRM stack, the encapsulation protocol is set to iphdr->protocol by
	339	* setting *skb_mac_header(skb) (see esp_output_udp_encap()) where skb->mac_header
	340	* points to iphdr->protocol (see xfrm4_tunnel_encap_add()).
	341	* However, in esp_xmit(), skb->mac_header doesn't point to iphdr->protocol.
	342	* Therefore, the protocol field needs to be corrected.
	343	*/
	344	ip_hdr(skb)->protocol = IPPROTO_UDP;
	345
	346	esph->seq_no = htonl(seq);
	347	}
	348
3dca3f38 SK	349	ip_hdr(skb)->tot_len = htons(skb->len);
	350	ip_send_check(ip_hdr(skb));
	351
c7dbf4c0 SK	352	if (hw_offload) {
	353	if (!skb_ext_add(skb, SKB_EXT_SEC_PATH))
	354	return -ENOMEM;
	355
	356	xo = xfrm_offload(skb);
	357	if (!xo)
	358	return -EINVAL;
	359
	360	xo->flags \|= XFRM_XMIT;
fca11ebd	361	return 0;
c7dbf4c0	362	}
fca11ebd	363
fca11ebd	364	err = esp_output_tail(x, skb, &esp);
4ff0308f	365	if (err)
fca11ebd SK	366	return err;
	367
	368	secpath_reset(skb);
	369
f015b900 SAS	370	if (skb_needs_linearize(skb, skb->dev->features) &&
	371	__skb_linearize(skb))
	372	return -ENOMEM;
fca11ebd SK	373	return 0;
	374	}
	375
7785bba2 SK	376	static const struct net_offload esp4_offload = {
	377	.callbacks = {
	378	.gro_receive = esp4_gro_receive,
7862b405	379	.gso_segment = esp4_gso_segment,
7785bba2 SK	380	},
	381	};
	382
fca11ebd	383	static const struct xfrm_type_offload esp_type_offload = {
fca11ebd SK	384	.owner = THIS_MODULE,
	385	.proto = IPPROTO_ESP,
	386	.input_tail = esp_input_tail,
	387	.xmit = esp_xmit,
7862b405	388	.encap = esp4_gso_encap,
fca11ebd SK	389	};
fca11ebd SK	390
7785bba2 SK	391	static int __init esp4_offload_init(void)
7785bba2 SK	392	{
fca11ebd SK	393	if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
	394	pr_info("%s: can't add xfrm type offload\n", __func__);
	395	return -EAGAIN;
	396	}
	397
7785bba2 SK	398	return inet_add_offload(&esp4_offload, IPPROTO_ESP);
	399	}
	400
	401	static void __exit esp4_offload_exit(void)
	402	{
4f518e80	403	xfrm_unregister_type_offload(&esp_type_offload, AF_INET);
7785bba2 SK	404	inet_del_offload(&esp4_offload, IPPROTO_ESP);
	405	}
	406
	407	module_init(esp4_offload_init);
	408	module_exit(esp4_offload_exit);
	409	MODULE_LICENSE("GPL");
	410	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
ffdb5211	411	MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);
67c20de3	412	MODULE_DESCRIPTION("IPV4 GSO/GRO offload support");