[linux-2.6-block.git] / net / ipv6 / esp6_offload.c

/*
 * IPV6 GSO/GRO offload support
 * Linux INET implementation
 *
 * Copyright (C) 2016 secunet Security Networks AG
 * Author: Steffen Klassert <steffen.klassert@secunet.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * 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/ip6_route.h>
#include <net/ipv6.h>
#include <linux/icmpv6.h>

static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
{
	int off = sizeof(struct ipv6hdr);
	struct ipv6_opt_hdr *exthdr;

	if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP))
		return offsetof(struct ipv6hdr, nexthdr);

	while (off < nhlen) {
		exthdr = (void *)ipv6_hdr + off;
		if (exthdr->nexthdr == NEXTHDR_ESP)
			return off;

		off += ipv6_optlen(exthdr);
	}

	return 0;
}

static struct sk_buff **esp6_gro_receive(struct sk_buff **head,
					 struct sk_buff *skb)
{
	int offset = skb_gro_offset(skb);
	struct xfrm_offload *xo;
	struct xfrm_state *x;
	__be32 seq;
	__be32 spi;
	int nhoff;
	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)) {
		err = secpath_set(skb);
		if (err)
			goto out;

		if (skb->sp->len == XFRM_MAX_DEPTH)
			goto out;

		x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
				      (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
				      spi, IPPROTO_ESP, AF_INET6);
		if (!x)
			goto out;

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

		xo = xfrm_offload(skb);
		if (!xo) {
			xfrm_state_put(x);
			goto out;
		}
	}

	xo->flags |= XFRM_GRO;

	nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
	if (!nhoff)
		goto out;

	IP6CB(skb)->nhoff = nhoff;
	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, 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:
	skb_push(skb, offset);
	NAPI_GRO_CB(skb)->same_flow = 0;
	NAPI_GRO_CB(skb)->flush = 1;

	return NULL;
}

static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ip_esp_hdr *esph;
	struct ipv6hdr *iph = ipv6_hdr(skb);
	struct xfrm_offload *xo = xfrm_offload(skb);
	int proto = iph->nexthdr;

	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 *esp6_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);

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

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

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

	xo->flags |= XFRM_GSO_SEGMENT;

	return x->outer_mode->gso_segment(x, skb, esp_features);
}

static int esp6_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 esp6_input_done2(skb, 0);
}

static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_t features)
{
	int len;
	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) || !x->xso.offload_handle ||
	    (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;

	if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
		esp.nfrags = esp6_output_head(x, skb, &esp);
		if (esp.nfrags < 0)
			return esp.nfrags;
	}

	seq = xo->seq.low;

	esph = ip_esp_hdr(skb);
	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(xo->seq.low + ((u64)xo->seq.hi << 32));

	len = skb->len - sizeof(struct ipv6hdr);
	if (len > IPV6_MAXPLEN)
		len = 0;

	ipv6_hdr(skb)->payload_len = htons(len);

	if (hw_offload)
		return 0;

	err = esp6_output_tail(x, skb, &esp);
	if (err)
		return err;

	secpath_reset(skb);

	return 0;
}

static const struct net_offload esp6_offload = {
	.callbacks = {
		.gro_receive = esp6_gro_receive,
		.gso_segment = esp6_gso_segment,
	},
};

static const struct xfrm_type_offload esp6_type_offload = {
	.description	= "ESP6 OFFLOAD",
	.owner		= THIS_MODULE,
	.proto	     	= IPPROTO_ESP,
	.input_tail	= esp6_input_tail,
	.xmit		= esp6_xmit,
	.encap		= esp6_gso_encap,
};

static int __init esp6_offload_init(void)
{
	if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
		pr_info("%s: can't add xfrm type offload\n", __func__);
		return -EAGAIN;
	}

	return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
}

static void __exit esp6_offload_exit(void)
{
	if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0)
		pr_info("%s: can't remove xfrm type offload\n", __func__);

	inet6_del_offload(&esp6_offload, IPPROTO_ESP);
}

module_init(esp6_offload_init);
module_exit(esp6_offload_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);
Commit	Line	Data
7785bba2 SK	1	/*
	2	* IPV6 GSO/GRO offload support
	3	* Linux INET implementation
	4	*
	5	* Copyright (C) 2016 secunet Security Networks AG
	6	* Author: Steffen Klassert <steffen.klassert@secunet.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms and conditions of the GNU General Public License,
	10	* version 2, as published by the Free Software Foundation.
	11	*
	12	* ESP GRO support
	13	*/
	14
	15	#include <linux/skbuff.h>
	16	#include <linux/init.h>
	17	#include <net/protocol.h>
	18	#include <crypto/aead.h>
	19	#include <crypto/authenc.h>
	20	#include <linux/err.h>
	21	#include <linux/module.h>
	22	#include <net/ip.h>
	23	#include <net/xfrm.h>
	24	#include <net/esp.h>
	25	#include <linux/scatterlist.h>
	26	#include <linux/kernel.h>
	27	#include <linux/slab.h>
	28	#include <linux/spinlock.h>
	29	#include <net/ip6_route.h>
	30	#include <net/ipv6.h>
	31	#include <linux/icmpv6.h>
	32
ca3a1b85 YK	33	static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
	34	{
	35	int off = sizeof(struct ipv6hdr);
	36	struct ipv6_opt_hdr *exthdr;
	37
	38	if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP))
	39	return offsetof(struct ipv6hdr, nexthdr);
	40
	41	while (off < nhlen) {
	42	exthdr = (void *)ipv6_hdr + off;
	43	if (exthdr->nexthdr == NEXTHDR_ESP)
	44	return off;
	45
	46	off += ipv6_optlen(exthdr);
	47	}
	48
	49	return 0;
	50	}
	51
7785bba2 SK	52	static struct sk_buff esp6_gro_receive(struct sk_buff head,
	53	struct sk_buff *skb)
	54	{
	55	int offset = skb_gro_offset(skb);
	56	struct xfrm_offload *xo;
	57	struct xfrm_state *x;
	58	__be32 seq;
	59	__be32 spi;
ca3a1b85	60	int nhoff;
7785bba2 SK	61	int err;
7785bba2 SK	62
374d1b5a SK	63	if (!pskb_pull(skb, offset))
374d1b5a SK	64	return NULL;
7785bba2 SK	65
	66	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
	67	goto out;
	68
bcd1f8a4 SK	69	xo = xfrm_offload(skb);
	70	if (!xo \|\| !(xo->flags & CRYPTO_DONE)) {
	71	err = secpath_set(skb);
	72	if (err)
	73	goto out;
7785bba2	74
bcd1f8a4 SK	75	if (skb->sp->len == XFRM_MAX_DEPTH)
bcd1f8a4 SK	76	goto out;
7785bba2	77
bcd1f8a4 SK	78	x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
	79	(xfrm_address_t *)&ipv6_hdr(skb)->daddr,
	80	spi, IPPROTO_ESP, AF_INET6);
	81	if (!x)
	82	goto out;
7785bba2	83
bcd1f8a4 SK	84	skb->sp->xvec[skb->sp->len++] = x;
bcd1f8a4 SK	85	skb->sp->olen++;
7785bba2	86
bcd1f8a4 SK	87	xo = xfrm_offload(skb);
	88	if (!xo) {
	89	xfrm_state_put(x);
	90	goto out;
	91	}
7785bba2	92	}
bcd1f8a4	93
7785bba2 SK	94	xo->flags \|= XFRM_GRO;
7785bba2 SK	95
ca3a1b85 YK	96	nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
	97	if (!nhoff)
	98	goto out;
	99
	100	IP6CB(skb)->nhoff = nhoff;
7785bba2 SK	101	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
	102	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
	103	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
	104	XFRM_SPI_SKB_CB(skb)->seq = seq;
	105
	106	/* We don't need to handle errors from xfrm_input, it does all
	107	* the error handling and frees the resources on error. */
	108	xfrm_input(skb, IPPROTO_ESP, spi, -2);
	109
	110	return ERR_PTR(-EINPROGRESS);
	111	out:
	112	skb_push(skb, offset);
	113	NAPI_GRO_CB(skb)->same_flow = 0;
	114	NAPI_GRO_CB(skb)->flush = 1;
	115
	116	return NULL;
	117	}
	118
7862b405 SK	119	static void esp6_gso_encap(struct xfrm_state x, struct sk_buff skb)
	120	{
	121	struct ip_esp_hdr *esph;
	122	struct ipv6hdr *iph = ipv6_hdr(skb);
	123	struct xfrm_offload *xo = xfrm_offload(skb);
	124	int proto = iph->nexthdr;
	125
	126	skb_push(skb, -skb_network_offset(skb));
	127	esph = ip_esp_hdr(skb);
	128	*skb_mac_header(skb) = IPPROTO_ESP;
	129
	130	esph->spi = x->id.spi;
	131	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
	132
	133	xo->proto = proto;
	134	}
	135
	136	static struct sk_buff esp6_gso_segment(struct sk_buff skb,
	137	netdev_features_t features)
	138	{
7862b405 SK	139	struct xfrm_state *x;
	140	struct ip_esp_hdr *esph;
	141	struct crypto_aead *aead;
7862b405 SK	142	netdev_features_t esp_features = features;
	143	struct xfrm_offload *xo = xfrm_offload(skb);
	144
ffa6f571	145	if (!xo)
3dca3f38	146	return ERR_PTR(-EINVAL);
7862b405	147
121d57af	148	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
5ca11440	149	return ERR_PTR(-EINVAL);
7862b405 SK	150
	151	x = skb->sp->xvec[skb->sp->len - 1];
	152	aead = x->data;
	153	esph = ip_esp_hdr(skb);
	154
	155	if (esph->spi != x->id.spi)
3dca3f38	156	return ERR_PTR(-EINVAL);
7862b405 SK	157
7862b405 SK	158	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
3dca3f38	159	return ERR_PTR(-EINVAL);
7862b405 SK	160
	161	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
	162
	163	skb->encap_hdr_csum = 1;
	164
3dca3f38 SK	165	if (!(features & NETIF_F_HW_ESP) \|\| !x->xso.offload_handle \|\|
3dca3f38 SK	166	(x->xso.dev != skb->dev))
7862b405	167	esp_features = features & ~(NETIF_F_SG \| NETIF_F_CSUM_MASK);
5211fcfb SN	168	else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
5211fcfb SN	169	esp_features = features & ~NETIF_F_CSUM_MASK;
7862b405	170
3dca3f38	171	xo->flags \|= XFRM_GSO_SEGMENT;
7862b405	172
3dca3f38	173	return x->outer_mode->gso_segment(x, skb, esp_features);
7862b405 SK	174	}
7862b405 SK	175
383d0350 SK	176	static int esp6_input_tail(struct xfrm_state x, struct sk_buff skb)
	177	{
	178	struct crypto_aead *aead = x->data;
e51a6472	179	struct xfrm_offload *xo = xfrm_offload(skb);
383d0350 SK	180
	181	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
	182	return -EINVAL;
	183
e51a6472 IT	184	if (!(xo->flags & CRYPTO_DONE))
e51a6472 IT	185	skb->ip_summed = CHECKSUM_NONE;
383d0350 SK	186
	187	return esp6_input_done2(skb, 0);
	188	}
	189
	190	static int esp6_xmit(struct xfrm_state x, struct sk_buff skb, netdev_features_t features)
	191	{
3dca3f38	192	int len;
383d0350 SK	193	int err;
	194	int alen;
	195	int blksize;
	196	struct xfrm_offload *xo;
	197	struct ip_esp_hdr *esph;
	198	struct crypto_aead *aead;
	199	struct esp_info esp;
	200	bool hw_offload = true;
3dca3f38	201	__u32 seq;
383d0350 SK	202
	203	esp.inplace = true;
	204
	205	xo = xfrm_offload(skb);
	206
	207	if (!xo)
	208	return -EINVAL;
	209
8f92e03e IT	210	if (!(features & NETIF_F_HW_ESP) \|\| !x->xso.offload_handle \|\|
8f92e03e IT	211	(x->xso.dev != skb->dev)) {
383d0350	212	xo->flags \|= CRYPTO_FALLBACK;
8f92e03e	213	hw_offload = false;
383d0350 SK	214	}
	215
	216	esp.proto = xo->proto;
	217
	218	/* skb is pure payload to encrypt */
	219
	220	aead = x->data;
	221	alen = crypto_aead_authsize(aead);
	222
	223	esp.tfclen = 0;
	224	/* XXX: Add support for tfc padding here. */
	225
	226	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	227	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	228	esp.plen = esp.clen - skb->len - esp.tfclen;
	229	esp.tailen = esp.tfclen + esp.plen + alen;
	230
	231	if (!hw_offload \|\| (hw_offload && !skb_is_gso(skb))) {
	232	esp.nfrags = esp6_output_head(x, skb, &esp);
	233	if (esp.nfrags < 0)
	234	return esp.nfrags;
	235	}
	236
3dca3f38 SK	237	seq = xo->seq.low;
3dca3f38 SK	238
383d0350 SK	239	esph = ip_esp_hdr(skb);
	240	esph->spi = x->id.spi;
	241
	242	skb_push(skb, -skb_network_offset(skb));
	243
	244	if (xo->flags & XFRM_GSO_SEGMENT) {
3dca3f38	245	esph->seq_no = htonl(seq);
383d0350	246
3dca3f38 SK	247	if (!skb_is_gso(skb))
	248	xo->seq.low++;
	249	else
	250	xo->seq.low += skb_shinfo(skb)->gso_segs;
383d0350 SK	251	}
383d0350 SK	252
3dca3f38 SK	253	esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
	254
	255	len = skb->len - sizeof(struct ipv6hdr);
	256	if (len > IPV6_MAXPLEN)
	257	len = 0;
	258
	259	ipv6_hdr(skb)->payload_len = htons(len);
	260
8f92e03e	261	if (hw_offload)
383d0350 SK	262	return 0;
383d0350 SK	263
383d0350	264	err = esp6_output_tail(x, skb, &esp);
4ff0308f	265	if (err)
383d0350 SK	266	return err;
	267
	268	secpath_reset(skb);
	269
	270	return 0;
	271	}
	272
7785bba2 SK	273	static const struct net_offload esp6_offload = {
	274	.callbacks = {
	275	.gro_receive = esp6_gro_receive,
7862b405	276	.gso_segment = esp6_gso_segment,
7785bba2 SK	277	},
	278	};
	279
383d0350 SK	280	static const struct xfrm_type_offload esp6_type_offload = {
	281	.description = "ESP6 OFFLOAD",
	282	.owner = THIS_MODULE,
	283	.proto = IPPROTO_ESP,
	284	.input_tail = esp6_input_tail,
	285	.xmit = esp6_xmit,
7862b405	286	.encap = esp6_gso_encap,
383d0350 SK	287	};
383d0350 SK	288
7785bba2 SK	289	static int __init esp6_offload_init(void)
7785bba2 SK	290	{
383d0350 SK	291	if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
	292	pr_info("%s: can't add xfrm type offload\n", __func__);
	293	return -EAGAIN;
	294	}
	295
7785bba2 SK	296	return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
	297	}
	298
	299	static void __exit esp6_offload_exit(void)
	300	{
383d0350 SK	301	if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0)
	302	pr_info("%s: can't remove xfrm type offload\n", __func__);
	303
7785bba2 SK	304	inet6_del_offload(&esp6_offload, IPPROTO_ESP);
	305	}
	306
	307	module_init(esp6_offload_init);
	308	module_exit(esp6_offload_exit);
	309	MODULE_LICENSE("GPL");
	310	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
ffdb5211	311	MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);