[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;

	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;
	}

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