[linux-2.6-block.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 list_head *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;

	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 *)&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)
{
	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.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 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;

	esp.inplace = true;

	xo = xfrm_offload(skb);

	if (!xo)
		return -EINVAL;

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

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

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

	if (hw_offload)
		return 0;

	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>");
MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);
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
d4546c25 DM	31	static struct sk_buff esp4_gro_receive(struct list_head head,
d4546c25 DM	32	struct sk_buff *skb)
7785bba2 SK	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
374d1b5a SK	41	if (!pskb_pull(skb, offset))
374d1b5a SK	42	return NULL;
7785bba2 SK	43
	44	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
	45	goto out;
	46
bcd1f8a4 SK	47	xo = xfrm_offload(skb);
	48	if (!xo \|\| !(xo->flags & CRYPTO_DONE)) {
	49	err = secpath_set(skb);
	50	if (err)
	51	goto out;
7785bba2	52
bcd1f8a4 SK	53	if (skb->sp->len == XFRM_MAX_DEPTH)
bcd1f8a4 SK	54	goto out;
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);
	59	if (!x)
	60	goto out;
7785bba2	61
bcd1f8a4 SK	62	skb->sp->xvec[skb->sp->len++] = x;
bcd1f8a4 SK	63	skb->sp->olen++;
7785bba2	64
bcd1f8a4 SK	65	xo = xfrm_offload(skb);
	66	if (!xo) {
	67	xfrm_state_put(x);
	68	goto out;
	69	}
7785bba2	70	}
bcd1f8a4	71
7785bba2 SK	72	xo->flags \|= XFRM_GRO;
	73
	74	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
	75	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
	76	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
	77	XFRM_SPI_SKB_CB(skb)->seq = seq;
	78
	79	/* We don't need to handle errors from xfrm_input, it does all
	80	* the error handling and frees the resources on error. */
	81	xfrm_input(skb, IPPROTO_ESP, spi, -2);
	82
	83	return ERR_PTR(-EINPROGRESS);
	84	out:
	85	skb_push(skb, offset);
	86	NAPI_GRO_CB(skb)->same_flow = 0;
	87	NAPI_GRO_CB(skb)->flush = 1;
	88
	89	return NULL;
	90	}
	91
7862b405 SK	92	static void esp4_gso_encap(struct xfrm_state x, struct sk_buff skb)
	93	{
	94	struct ip_esp_hdr *esph;
	95	struct iphdr *iph = ip_hdr(skb);
	96	struct xfrm_offload *xo = xfrm_offload(skb);
	97	int proto = iph->protocol;
	98
	99	skb_push(skb, -skb_network_offset(skb));
	100	esph = ip_esp_hdr(skb);
	101	*skb_mac_header(skb) = IPPROTO_ESP;
	102
	103	esph->spi = x->id.spi;
	104	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
	105
	106	xo->proto = proto;
	107	}
	108
	109	static struct sk_buff esp4_gso_segment(struct sk_buff skb,
	110	netdev_features_t features)
	111	{
7862b405 SK	112	struct xfrm_state *x;
	113	struct ip_esp_hdr *esph;
	114	struct crypto_aead *aead;
7862b405 SK	115	netdev_features_t esp_features = features;
	116	struct xfrm_offload *xo = xfrm_offload(skb);
	117
	118	if (!xo)
3dca3f38	119	return ERR_PTR(-EINVAL);
7862b405	120
121d57af	121	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
5ca11440	122	return ERR_PTR(-EINVAL);
7862b405 SK	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)
3dca3f38	129	return ERR_PTR(-EINVAL);
7862b405 SK	130
7862b405 SK	131	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
3dca3f38	132	return ERR_PTR(-EINVAL);
7862b405 SK	133
	134	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
	135
	136	skb->encap_hdr_csum = 1;
	137
fcb662de	138	if (!(features & NETIF_F_HW_ESP) \|\| x->xso.dev != skb->dev)
7862b405	139	esp_features = features & ~(NETIF_F_SG \| NETIF_F_CSUM_MASK);
5211fcfb SN	140	else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
5211fcfb SN	141	esp_features = features & ~NETIF_F_CSUM_MASK;
7862b405	142
3dca3f38	143	xo->flags \|= XFRM_GSO_SEGMENT;
7862b405	144
3dca3f38	145	return x->outer_mode->gso_segment(x, skb, esp_features);
7862b405 SK	146	}
7862b405 SK	147
fca11ebd SK	148	static int esp_input_tail(struct xfrm_state x, struct sk_buff skb)
	149	{
	150	struct crypto_aead *aead = x->data;
ec9567a9	151	struct xfrm_offload *xo = xfrm_offload(skb);
fca11ebd SK	152
	153	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
	154	return -EINVAL;
	155
ec9567a9 IT	156	if (!(xo->flags & CRYPTO_DONE))
ec9567a9 IT	157	skb->ip_summed = CHECKSUM_NONE;
fca11ebd SK	158
	159	return esp_input_done2(skb, 0);
	160	}
	161
	162	static int esp_xmit(struct xfrm_state x, struct sk_buff skb, netdev_features_t features)
	163	{
	164	int err;
	165	int alen;
	166	int blksize;
	167	struct xfrm_offload *xo;
	168	struct ip_esp_hdr *esph;
	169	struct crypto_aead *aead;
	170	struct esp_info esp;
	171	bool hw_offload = true;
3dca3f38	172	__u32 seq;
fca11ebd SK	173
	174	esp.inplace = true;
	175
	176	xo = xfrm_offload(skb);
	177
	178	if (!xo)
	179	return -EINVAL;
	180
fcb662de	181	if (!(features & NETIF_F_HW_ESP) \|\| x->xso.dev != skb->dev) {
fca11ebd SK	182	xo->flags \|= CRYPTO_FALLBACK;
	183	hw_offload = false;
	184	}
	185
	186	esp.proto = xo->proto;
	187
	188	/* skb is pure payload to encrypt */
	189
	190	aead = x->data;
	191	alen = crypto_aead_authsize(aead);
	192
	193	esp.tfclen = 0;
	194	/* XXX: Add support for tfc padding here. */
	195
	196	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	197	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	198	esp.plen = esp.clen - skb->len - esp.tfclen;
	199	esp.tailen = esp.tfclen + esp.plen + alen;
	200
	201	esp.esph = ip_esp_hdr(skb);
	202
	203
	204	if (!hw_offload \|\| (hw_offload && !skb_is_gso(skb))) {
	205	esp.nfrags = esp_output_head(x, skb, &esp);
	206	if (esp.nfrags < 0)
	207	return esp.nfrags;
	208	}
	209
3dca3f38 SK	210	seq = xo->seq.low;
3dca3f38 SK	211
fca11ebd SK	212	esph = esp.esph;
	213	esph->spi = x->id.spi;
	214
	215	skb_push(skb, -skb_network_offset(skb));
	216
	217	if (xo->flags & XFRM_GSO_SEGMENT) {
3dca3f38 SK	218	esph->seq_no = htonl(seq);
	219
	220	if (!skb_is_gso(skb))
	221	xo->seq.low++;
	222	else
	223	xo->seq.low += skb_shinfo(skb)->gso_segs;
fca11ebd SK	224	}
fca11ebd SK	225
3dca3f38 SK	226	esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
	227
	228	ip_hdr(skb)->tot_len = htons(skb->len);
	229	ip_send_check(ip_hdr(skb));
	230
fca11ebd SK	231	if (hw_offload)
	232	return 0;
	233
fca11ebd	234	err = esp_output_tail(x, skb, &esp);
4ff0308f	235	if (err)
fca11ebd SK	236	return err;
	237
	238	secpath_reset(skb);
	239
	240	return 0;
	241	}
	242
7785bba2 SK	243	static const struct net_offload esp4_offload = {
	244	.callbacks = {
	245	.gro_receive = esp4_gro_receive,
7862b405	246	.gso_segment = esp4_gso_segment,
7785bba2 SK	247	},
	248	};
	249
fca11ebd SK	250	static const struct xfrm_type_offload esp_type_offload = {
	251	.description = "ESP4 OFFLOAD",
	252	.owner = THIS_MODULE,
	253	.proto = IPPROTO_ESP,
	254	.input_tail = esp_input_tail,
	255	.xmit = esp_xmit,
7862b405	256	.encap = esp4_gso_encap,
fca11ebd SK	257	};
fca11ebd SK	258
7785bba2 SK	259	static int __init esp4_offload_init(void)
7785bba2 SK	260	{
fca11ebd SK	261	if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
	262	pr_info("%s: can't add xfrm type offload\n", __func__);
	263	return -EAGAIN;
	264	}
	265
7785bba2 SK	266	return inet_add_offload(&esp4_offload, IPPROTO_ESP);
	267	}
	268
	269	static void __exit esp4_offload_exit(void)
	270	{
fca11ebd SK	271	if (xfrm_unregister_type_offload(&esp_type_offload, AF_INET) < 0)
	272	pr_info("%s: can't remove xfrm type offload\n", __func__);
	273
7785bba2 SK	274	inet_del_offload(&esp4_offload, IPPROTO_ESP);
	275	}
	276
	277	module_init(esp4_offload_init);
	278	module_exit(esp4_offload_exit);
	279	MODULE_LICENSE("GPL");
	280	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
ffdb5211	281	MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);