[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 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 err;

	skb_pull(skb, offset);

	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;

	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)
{
	__u32 seq;
	int err = 0;
	struct sk_buff *skb2;
	struct xfrm_state *x;
	struct ip_esp_hdr *esph;
	struct crypto_aead *aead;
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	netdev_features_t esp_features = features;
	struct xfrm_offload *xo = xfrm_offload(skb);

	if (!xo)
		goto out;

	seq = xo->seq.low;

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

	if (esph->spi != x->id.spi)
		goto out;

	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
		goto out;

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

	skb->encap_hdr_csum = 1;

	if (!(features & NETIF_F_HW_ESP))
		esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);

	segs = x->outer_mode->gso_segment(x, skb, esp_features);
	if (IS_ERR_OR_NULL(segs))
		goto out;

	__skb_pull(skb, skb->data - skb_mac_header(skb));

	skb2 = segs;
	do {
		struct sk_buff *nskb = skb2->next;

		xo = xfrm_offload(skb2);
		xo->flags |= XFRM_GSO_SEGMENT;
		xo->seq.low = seq;
		xo->seq.hi = xfrm_replay_seqhi(x, seq);

		if(!(features & NETIF_F_HW_ESP))
			xo->flags |= CRYPTO_FALLBACK;

		x->outer_mode->xmit(x, skb2);

		err = x->type_offload->xmit(x, skb2, esp_features);
		if (err) {
			kfree_skb_list(segs);
			return ERR_PTR(err);
		}

		if (!skb_is_gso(skb2))
			seq++;
		else
			seq += skb_shinfo(skb2)->gso_segs;

		skb_push(skb2, skb2->mac_len);
		skb2 = nskb;
	} while (skb2);

out:
	return segs;
}

static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
{
	struct crypto_aead *aead = x->data;

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

	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 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;

	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;
	}

	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(xo->seq.low);
	} else {
		int len;

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

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

	if (hw_offload)
		return 0;

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

	err = esp6_output_tail(x, skb, &esp);
	if (err < 0)
		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>");
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
	33	static struct sk_buff esp6_gro_receive(struct sk_buff head,
	34	struct sk_buff *skb)
	35	{
	36	int offset = skb_gro_offset(skb);
	37	struct xfrm_offload *xo;
	38	struct xfrm_state *x;
	39	__be32 seq;
	40	__be32 spi;
	41	int err;
	42
	43	skb_pull(skb, offset);
	44
	45	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
	46	goto out;
	47
bcd1f8a4 SK	48	xo = xfrm_offload(skb);
	49	if (!xo \|\| !(xo->flags & CRYPTO_DONE)) {
	50	err = secpath_set(skb);
	51	if (err)
	52	goto out;
7785bba2	53
bcd1f8a4 SK	54	if (skb->sp->len == XFRM_MAX_DEPTH)
bcd1f8a4 SK	55	goto out;
7785bba2	56
bcd1f8a4 SK	57	x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
	58	(xfrm_address_t *)&ipv6_hdr(skb)->daddr,
	59	spi, IPPROTO_ESP, AF_INET6);
	60	if (!x)
	61	goto out;
7785bba2	62
bcd1f8a4 SK	63	skb->sp->xvec[skb->sp->len++] = x;
bcd1f8a4 SK	64	skb->sp->olen++;
7785bba2	65
bcd1f8a4 SK	66	xo = xfrm_offload(skb);
	67	if (!xo) {
	68	xfrm_state_put(x);
	69	goto out;
	70	}
7785bba2	71	}
bcd1f8a4	72
7785bba2 SK	73	xo->flags \|= XFRM_GRO;
	74
	75	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
	76	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
	77	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
	78	XFRM_SPI_SKB_CB(skb)->seq = seq;
	79
	80	/* We don't need to handle errors from xfrm_input, it does all
	81	* the error handling and frees the resources on error. */
	82	xfrm_input(skb, IPPROTO_ESP, spi, -2);
	83
	84	return ERR_PTR(-EINPROGRESS);
	85	out:
	86	skb_push(skb, offset);
	87	NAPI_GRO_CB(skb)->same_flow = 0;
	88	NAPI_GRO_CB(skb)->flush = 1;
	89
	90	return NULL;
	91	}
	92
7862b405 SK	93	static void esp6_gso_encap(struct xfrm_state x, struct sk_buff skb)
	94	{
	95	struct ip_esp_hdr *esph;
	96	struct ipv6hdr *iph = ipv6_hdr(skb);
	97	struct xfrm_offload *xo = xfrm_offload(skb);
	98	int proto = iph->nexthdr;
	99
	100	skb_push(skb, -skb_network_offset(skb));
	101	esph = ip_esp_hdr(skb);
	102	*skb_mac_header(skb) = IPPROTO_ESP;
	103
	104	esph->spi = x->id.spi;
	105	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
	106
	107	xo->proto = proto;
	108	}
	109
	110	static struct sk_buff esp6_gso_segment(struct sk_buff skb,
	111	netdev_features_t features)
	112	{
	113	__u32 seq;
	114	int err = 0;
	115	struct sk_buff *skb2;
	116	struct xfrm_state *x;
	117	struct ip_esp_hdr *esph;
	118	struct crypto_aead *aead;
	119	struct sk_buff *segs = ERR_PTR(-EINVAL);
	120	netdev_features_t esp_features = features;
	121	struct xfrm_offload *xo = xfrm_offload(skb);
	122
ffa6f571	123	if (!xo)
7862b405 SK	124	goto out;
	125
	126	seq = xo->seq.low;
	127
	128	x = skb->sp->xvec[skb->sp->len - 1];
	129	aead = x->data;
	130	esph = ip_esp_hdr(skb);
	131
	132	if (esph->spi != x->id.spi)
	133	goto out;
	134
	135	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
	136	goto out;
	137
	138	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
	139
	140	skb->encap_hdr_csum = 1;
	141
	142	if (!(features & NETIF_F_HW_ESP))
	143	esp_features = features & ~(NETIF_F_SG \| NETIF_F_CSUM_MASK);
	144
	145	segs = x->outer_mode->gso_segment(x, skb, esp_features);
	146	if (IS_ERR_OR_NULL(segs))
	147	goto out;
	148
	149	__skb_pull(skb, skb->data - skb_mac_header(skb));
	150
	151	skb2 = segs;
	152	do {
	153	struct sk_buff *nskb = skb2->next;
	154
	155	xo = xfrm_offload(skb2);
	156	xo->flags \|= XFRM_GSO_SEGMENT;
	157	xo->seq.low = seq;
	158	xo->seq.hi = xfrm_replay_seqhi(x, seq);
	159
	160	if(!(features & NETIF_F_HW_ESP))
	161	xo->flags \|= CRYPTO_FALLBACK;
	162
	163	x->outer_mode->xmit(x, skb2);
	164
	165	err = x->type_offload->xmit(x, skb2, esp_features);
	166	if (err) {
	167	kfree_skb_list(segs);
	168	return ERR_PTR(err);
	169	}
	170
	171	if (!skb_is_gso(skb2))
	172	seq++;
	173	else
	174	seq += skb_shinfo(skb2)->gso_segs;
	175
	176	skb_push(skb2, skb2->mac_len);
	177	skb2 = nskb;
	178	} while (skb2);
	179
	180	out:
	181	return segs;
	182	}
	183
383d0350 SK	184	static int esp6_input_tail(struct xfrm_state x, struct sk_buff skb)
	185	{
	186	struct crypto_aead *aead = x->data;
	187
	188	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
	189	return -EINVAL;
	190
	191	skb->ip_summed = CHECKSUM_NONE;
	192
	193	return esp6_input_done2(skb, 0);
	194	}
	195
	196	static int esp6_xmit(struct xfrm_state x, struct sk_buff skb, netdev_features_t features)
	197	{
	198	int err;
	199	int alen;
	200	int blksize;
	201	struct xfrm_offload *xo;
	202	struct ip_esp_hdr *esph;
	203	struct crypto_aead *aead;
	204	struct esp_info esp;
	205	bool hw_offload = true;
	206
	207	esp.inplace = true;
	208
	209	xo = xfrm_offload(skb);
	210
	211	if (!xo)
	212	return -EINVAL;
	213
8f92e03e IT	214	if (!(features & NETIF_F_HW_ESP) \|\| !x->xso.offload_handle \|\|
8f92e03e IT	215	(x->xso.dev != skb->dev)) {
383d0350	216	xo->flags \|= CRYPTO_FALLBACK;
8f92e03e	217	hw_offload = false;
383d0350 SK	218	}
	219
	220	esp.proto = xo->proto;
	221
	222	/* skb is pure payload to encrypt */
	223
	224	aead = x->data;
	225	alen = crypto_aead_authsize(aead);
	226
	227	esp.tfclen = 0;
	228	/* XXX: Add support for tfc padding here. */
	229
	230	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	231	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	232	esp.plen = esp.clen - skb->len - esp.tfclen;
	233	esp.tailen = esp.tfclen + esp.plen + alen;
	234
	235	if (!hw_offload \|\| (hw_offload && !skb_is_gso(skb))) {
	236	esp.nfrags = esp6_output_head(x, skb, &esp);
	237	if (esp.nfrags < 0)
	238	return esp.nfrags;
	239	}
	240
	241	esph = ip_esp_hdr(skb);
	242	esph->spi = x->id.spi;
	243
	244	skb_push(skb, -skb_network_offset(skb));
	245
	246	if (xo->flags & XFRM_GSO_SEGMENT) {
	247	esph->seq_no = htonl(xo->seq.low);
	248	} else {
	249	int len;
	250
	251	len = skb->len - sizeof(struct ipv6hdr);
	252	if (len > IPV6_MAXPLEN)
	253	len = 0;
	254
	255	ipv6_hdr(skb)->payload_len = htons(len);
	256	}
	257
8f92e03e	258	if (hw_offload)
383d0350 SK	259	return 0;
	260
	261	esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
	262
	263	err = esp6_output_tail(x, skb, &esp);
	264	if (err < 0)
	265	return err;
	266
	267	secpath_reset(skb);
	268
	269	return 0;
	270	}
	271
7785bba2 SK	272	static const struct net_offload esp6_offload = {
	273	.callbacks = {
	274	.gro_receive = esp6_gro_receive,
7862b405	275	.gso_segment = esp6_gso_segment,
7785bba2 SK	276	},
	277	};
	278
383d0350 SK	279	static const struct xfrm_type_offload esp6_type_offload = {
	280	.description = "ESP6 OFFLOAD",
	281	.owner = THIS_MODULE,
	282	.proto = IPPROTO_ESP,
	283	.input_tail = esp6_input_tail,
	284	.xmit = esp6_xmit,
7862b405	285	.encap = esp6_gso_encap,
383d0350 SK	286	};
383d0350 SK	287
7785bba2 SK	288	static int __init esp6_offload_init(void)
7785bba2 SK	289	{
383d0350 SK	290	if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
	291	pr_info("%s: can't add xfrm type offload\n", __func__);
	292	return -EAGAIN;
	293	}
	294
7785bba2 SK	295	return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
	296	}
	297
	298	static void __exit esp6_offload_exit(void)
	299	{
383d0350 SK	300	if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0)
	301	pr_info("%s: can't remove xfrm type offload\n", __func__);
	302
7785bba2 SK	303	inet6_del_offload(&esp6_offload, IPPROTO_ESP);
	304	}
	305
	306	module_init(esp6_offload_init);
	307	module_exit(esp6_offload_exit);
	308	MODULE_LICENSE("GPL");
	309	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");