[mirror_ubuntu-artful-kernel.git] / net / ipv4 / esp4_offload.c

/*
 * IPV4 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/udp.h>

static struct sk_buff **esp4_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 *)&ip_hdr(skb)->daddr,
				      spi, IPPROTO_ESP, AF_INET);
		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.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:
	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 *esp4_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 esp_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 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;

	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;

	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;
	}

	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(xo->seq.low);
	} else {
		ip_hdr(skb)->tot_len = htons(skb->len);
		ip_send_check(ip_hdr(skb));
	}

	if (hw_offload)
		return 0;

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

	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)
{
	if (xfrm_unregister_type_offload(&esp_type_offload, AF_INET) < 0)
		pr_info("%s: can't remove xfrm type offload\n", __func__);

	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>");
Commit	Line	Data
7785bba2 SK	1	/*
	2	* IPV4 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/udp.h>
	30
	31	static struct sk_buff esp4_gro_receive(struct sk_buff head,
	32	struct sk_buff *skb)
	33	{
	34	int offset = skb_gro_offset(skb);
	35	struct xfrm_offload *xo;
	36	struct xfrm_state *x;
	37	__be32 seq;
	38	__be32 spi;
	39	int err;
	40
	41	skb_pull(skb, offset);
	42
	43	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
	44	goto out;
	45
bcd1f8a4 SK	46	xo = xfrm_offload(skb);
	47	if (!xo \|\| !(xo->flags & CRYPTO_DONE)) {
	48	err = secpath_set(skb);
	49	if (err)
	50	goto out;
7785bba2	51
bcd1f8a4 SK	52	if (skb->sp->len == XFRM_MAX_DEPTH)
bcd1f8a4 SK	53	goto out;
7785bba2	54
bcd1f8a4 SK	55	x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
	56	(xfrm_address_t *)&ip_hdr(skb)->daddr,
	57	spi, IPPROTO_ESP, AF_INET);
	58	if (!x)
	59	goto out;
7785bba2	60
bcd1f8a4 SK	61	skb->sp->xvec[skb->sp->len++] = x;
bcd1f8a4 SK	62	skb->sp->olen++;
7785bba2	63
bcd1f8a4 SK	64	xo = xfrm_offload(skb);
	65	if (!xo) {
	66	xfrm_state_put(x);
	67	goto out;
	68	}
7785bba2	69	}
bcd1f8a4	70
7785bba2 SK	71	xo->flags \|= XFRM_GRO;
	72
	73	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
	74	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
	75	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
	76	XFRM_SPI_SKB_CB(skb)->seq = seq;
	77
	78	/* We don't need to handle errors from xfrm_input, it does all
	79	* the error handling and frees the resources on error. */
	80	xfrm_input(skb, IPPROTO_ESP, spi, -2);
	81
	82	return ERR_PTR(-EINPROGRESS);
	83	out:
	84	skb_push(skb, offset);
	85	NAPI_GRO_CB(skb)->same_flow = 0;
	86	NAPI_GRO_CB(skb)->flush = 1;
	87
	88	return NULL;
	89	}
	90
7862b405 SK	91	static void esp4_gso_encap(struct xfrm_state x, struct sk_buff skb)
	92	{
	93	struct ip_esp_hdr *esph;
	94	struct iphdr *iph = ip_hdr(skb);
	95	struct xfrm_offload *xo = xfrm_offload(skb);
	96	int proto = iph->protocol;
	97
	98	skb_push(skb, -skb_network_offset(skb));
	99	esph = ip_esp_hdr(skb);
	100	*skb_mac_header(skb) = IPPROTO_ESP;
	101
	102	esph->spi = x->id.spi;
	103	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
	104
	105	xo->proto = proto;
	106	}
	107
	108	static struct sk_buff esp4_gso_segment(struct sk_buff skb,
	109	netdev_features_t features)
	110	{
	111	__u32 seq;
	112	int err = 0;
	113	struct sk_buff *skb2;
	114	struct xfrm_state *x;
	115	struct ip_esp_hdr *esph;
	116	struct crypto_aead *aead;
	117	struct sk_buff *segs = ERR_PTR(-EINVAL);
	118	netdev_features_t esp_features = features;
	119	struct xfrm_offload *xo = xfrm_offload(skb);
	120
	121	if (!xo)
	122	goto out;
	123
	124	seq = xo->seq.low;
	125
	126	x = skb->sp->xvec[skb->sp->len - 1];
	127	aead = x->data;
	128	esph = ip_esp_hdr(skb);
	129
	130	if (esph->spi != x->id.spi)
	131	goto out;
	132
	133	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
	134	goto out;
	135
	136	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
	137
	138	skb->encap_hdr_csum = 1;
	139
	140	if (!(features & NETIF_F_HW_ESP))
	141	esp_features = features & ~(NETIF_F_SG \| NETIF_F_CSUM_MASK);
	142
	143	segs = x->outer_mode->gso_segment(x, skb, esp_features);
	144	if (IS_ERR_OR_NULL(segs))
	145	goto out;
	146
	147	__skb_pull(skb, skb->data - skb_mac_header(skb));
	148
	149	skb2 = segs;
	150	do {
	151	struct sk_buff *nskb = skb2->next;
	152
	153	xo = xfrm_offload(skb2);
	154	xo->flags \|= XFRM_GSO_SEGMENT;
155	xo->seq.low = seq;
156	xo->seq.hi = xfrm_replay_seqhi(x, seq);
157
158	if(!(features & NETIF_F_HW_ESP))
159	xo->flags \|= CRYPTO_FALLBACK;
160
161	x->outer_mode->xmit(x, skb2);
162
163	err = x->type_offload->xmit(x, skb2, esp_features);
164	if (err) {
165	kfree_skb_list(segs);
166	return ERR_PTR(err);
167	}
168
169	if (!skb_is_gso(skb2))
170	seq++;
171	else
172	seq += skb_shinfo(skb2)->gso_segs;
173
174	skb_push(skb2, skb2->mac_len);
175	skb2 = nskb;
176	} while (skb2);
177
178	out:
179	return segs;
180	}
181
fca11ebd SK	182	static int esp_input_tail(struct xfrm_state x, struct sk_buff skb)
	183	{
	184	struct crypto_aead *aead = x->data;
	185
	186	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
	187	return -EINVAL;
	188
	189	skb->ip_summed = CHECKSUM_NONE;
	190
	191	return esp_input_done2(skb, 0);
	192	}
	193
	194	static int esp_xmit(struct xfrm_state x, struct sk_buff skb, netdev_features_t features)
	195	{
	196	int err;
	197	int alen;
	198	int blksize;
	199	struct xfrm_offload *xo;
	200	struct ip_esp_hdr *esph;
	201	struct crypto_aead *aead;
	202	struct esp_info esp;
	203	bool hw_offload = true;
	204
	205	esp.inplace = true;
	206
	207	xo = xfrm_offload(skb);
	208
	209	if (!xo)
	210	return -EINVAL;
	211
8f92e03e IT	212	if (!(features & NETIF_F_HW_ESP) \|\| !x->xso.offload_handle \|\|
8f92e03e IT	213	(x->xso.dev != skb->dev)) {
fca11ebd SK	214	xo->flags \|= CRYPTO_FALLBACK;
	215	hw_offload = false;
	216	}
	217
	218	esp.proto = xo->proto;
	219
	220	/* skb is pure payload to encrypt */
	221
	222	aead = x->data;
	223	alen = crypto_aead_authsize(aead);
	224
	225	esp.tfclen = 0;
	226	/* XXX: Add support for tfc padding here. */
	227
	228	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	229	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	230	esp.plen = esp.clen - skb->len - esp.tfclen;
	231	esp.tailen = esp.tfclen + esp.plen + alen;
	232
	233	esp.esph = ip_esp_hdr(skb);
	234
	235
	236	if (!hw_offload \|\| (hw_offload && !skb_is_gso(skb))) {
	237	esp.nfrags = esp_output_head(x, skb, &esp);
	238	if (esp.nfrags < 0)
	239	return esp.nfrags;
	240	}
	241
	242	esph = esp.esph;
	243	esph->spi = x->id.spi;
	244
	245	skb_push(skb, -skb_network_offset(skb));
	246
	247	if (xo->flags & XFRM_GSO_SEGMENT) {
	248	esph->seq_no = htonl(xo->seq.low);
	249	} else {
	250	ip_hdr(skb)->tot_len = htons(skb->len);
	251	ip_send_check(ip_hdr(skb));
	252	}
	253
	254	if (hw_offload)
	255	return 0;
	256
	257	esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
	258
	259	err = esp_output_tail(x, skb, &esp);
4ff0308f	260	if (err)
fca11ebd SK	261	return err;
	262
	263	secpath_reset(skb);
	264
	265	return 0;
	266	}
	267
7785bba2 SK	268	static const struct net_offload esp4_offload = {
	269	.callbacks = {
	270	.gro_receive = esp4_gro_receive,
7862b405	271	.gso_segment = esp4_gso_segment,
7785bba2 SK	272	},
	273	};
	274
fca11ebd SK	275	static const struct xfrm_type_offload esp_type_offload = {
	276	.description = "ESP4 OFFLOAD",
	277	.owner = THIS_MODULE,
	278	.proto = IPPROTO_ESP,
	279	.input_tail = esp_input_tail,
	280	.xmit = esp_xmit,
7862b405	281	.encap = esp4_gso_encap,
fca11ebd SK	282	};
fca11ebd SK	283
7785bba2 SK	284	static int __init esp4_offload_init(void)
7785bba2 SK	285	{
fca11ebd SK	286	if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
	287	pr_info("%s: can't add xfrm type offload\n", __func__);
	288	return -EAGAIN;
	289	}
	290
7785bba2 SK	291	return inet_add_offload(&esp4_offload, IPPROTO_ESP);
	292	}
	293
	294	static void __exit esp4_offload_exit(void)
	295	{
fca11ebd SK	296	if (xfrm_unregister_type_offload(&esp_type_offload, AF_INET) < 0)
	297	pr_info("%s: can't remove xfrm type offload\n", __func__);
	298
7785bba2 SK	299	inet_del_offload(&esp4_offload, IPPROTO_ESP);
	300	}
	301
	302	module_init(esp4_offload_init);
	303	module_exit(esp4_offload_exit);
	304	MODULE_LICENSE("GPL");
	305	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");