[mirror_ubuntu-bionic-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;

	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)
{
	__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;

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

	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>");
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
	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
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	{
	112	__u32 seq;
	113	int err = 0;
	114	struct sk_buff *skb2;
	115	struct xfrm_state *x;
	116	struct ip_esp_hdr *esph;
	117	struct crypto_aead *aead;
	118	struct sk_buff *segs = ERR_PTR(-EINVAL);
	119	netdev_features_t esp_features = features;
	120	struct xfrm_offload *xo = xfrm_offload(skb);
	121
	122	if (!xo)
	123	goto out;
	124
121d57af WB	125	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
	126	goto out;
	127
7862b405 SK	128	seq = xo->seq.low;
	129
	130	x = skb->sp->xvec[skb->sp->len - 1];
	131	aead = x->data;
	132	esph = ip_esp_hdr(skb);
	133
	134	if (esph->spi != x->id.spi)
	135	goto out;
	136
	137	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
	138	goto out;
	139
	140	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
	141
	142	skb->encap_hdr_csum = 1;
	143
	144	if (!(features & NETIF_F_HW_ESP))
	145	esp_features = features & ~(NETIF_F_SG \| NETIF_F_CSUM_MASK);
	146
	147	segs = x->outer_mode->gso_segment(x, skb, esp_features);
	148	if (IS_ERR_OR_NULL(segs))
	149	goto out;
	150
	151	__skb_pull(skb, skb->data - skb_mac_header(skb));
	152
	153	skb2 = segs;
	154	do {
	155	struct sk_buff *nskb = skb2->next;
	156
	157	xo = xfrm_offload(skb2);
	158	xo->flags \|= XFRM_GSO_SEGMENT;
	159	xo->seq.low = seq;
	160	xo->seq.hi = xfrm_replay_seqhi(x, seq);
	161
	162	if(!(features & NETIF_F_HW_ESP))
	163	xo->flags \|= CRYPTO_FALLBACK;
	164
	165	x->outer_mode->xmit(x, skb2);
	166
	167	err = x->type_offload->xmit(x, skb2, esp_features);
	168	if (err) {
	169	kfree_skb_list(segs);
	170	return ERR_PTR(err);
	171	}
	172
	173	if (!skb_is_gso(skb2))
	174	seq++;
	175	else
	176	seq += skb_shinfo(skb2)->gso_segs;
	177
	178	skb_push(skb2, skb2->mac_len);
	179	skb2 = nskb;
	180	} while (skb2);
	181
	182	out:
	183	return segs;
	184	}
	185
fca11ebd SK	186	static int esp_input_tail(struct xfrm_state x, struct sk_buff skb)
	187	{
	188	struct crypto_aead *aead = x->data;
ec9567a9	189	struct xfrm_offload *xo = xfrm_offload(skb);
fca11ebd SK	190
	191	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
	192	return -EINVAL;
	193
ec9567a9 IT	194	if (!(xo->flags & CRYPTO_DONE))
ec9567a9 IT	195	skb->ip_summed = CHECKSUM_NONE;
fca11ebd SK	196
	197	return esp_input_done2(skb, 0);
	198	}
	199
	200	static int esp_xmit(struct xfrm_state x, struct sk_buff skb, netdev_features_t features)
	201	{
	202	int err;
	203	int alen;
	204	int blksize;
	205	struct xfrm_offload *xo;
	206	struct ip_esp_hdr *esph;
	207	struct crypto_aead *aead;
	208	struct esp_info esp;
	209	bool hw_offload = true;
	210
	211	esp.inplace = true;
	212
	213	xo = xfrm_offload(skb);
	214
	215	if (!xo)
	216	return -EINVAL;
	217
8f92e03e IT	218	if (!(features & NETIF_F_HW_ESP) \|\| !x->xso.offload_handle \|\|
8f92e03e IT	219	(x->xso.dev != skb->dev)) {
fca11ebd SK	220	xo->flags \|= CRYPTO_FALLBACK;
	221	hw_offload = false;
	222	}
	223
	224	esp.proto = xo->proto;
	225
	226	/* skb is pure payload to encrypt */
	227
	228	aead = x->data;
	229	alen = crypto_aead_authsize(aead);
	230
	231	esp.tfclen = 0;
	232	/* XXX: Add support for tfc padding here. */
	233
	234	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
	235	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
	236	esp.plen = esp.clen - skb->len - esp.tfclen;
	237	esp.tailen = esp.tfclen + esp.plen + alen;
	238
	239	esp.esph = ip_esp_hdr(skb);
	240
	241
	242	if (!hw_offload \|\| (hw_offload && !skb_is_gso(skb))) {
	243	esp.nfrags = esp_output_head(x, skb, &esp);
	244	if (esp.nfrags < 0)
	245	return esp.nfrags;
	246	}
	247
	248	esph = esp.esph;
	249	esph->spi = x->id.spi;
	250
	251	skb_push(skb, -skb_network_offset(skb));
	252
	253	if (xo->flags & XFRM_GSO_SEGMENT) {
	254	esph->seq_no = htonl(xo->seq.low);
	255	} else {
	256	ip_hdr(skb)->tot_len = htons(skb->len);
	257	ip_send_check(ip_hdr(skb));
	258	}
	259
	260	if (hw_offload)
	261	return 0;
	262
	263	esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
	264
	265	err = esp_output_tail(x, skb, &esp);
4ff0308f	266	if (err)
fca11ebd SK	267	return err;
	268
	269	secpath_reset(skb);
	270
	271	return 0;
	272	}
	273
7785bba2 SK	274	static const struct net_offload esp4_offload = {
	275	.callbacks = {
	276	.gro_receive = esp4_gro_receive,
7862b405	277	.gso_segment = esp4_gso_segment,
7785bba2 SK	278	},
	279	};
	280
fca11ebd SK	281	static const struct xfrm_type_offload esp_type_offload = {
	282	.description = "ESP4 OFFLOAD",
	283	.owner = THIS_MODULE,
	284	.proto = IPPROTO_ESP,
	285	.input_tail = esp_input_tail,
	286	.xmit = esp_xmit,
7862b405	287	.encap = esp4_gso_encap,
fca11ebd SK	288	};
fca11ebd SK	289
7785bba2 SK	290	static int __init esp4_offload_init(void)
7785bba2 SK	291	{
fca11ebd SK	292	if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
	293	pr_info("%s: can't add xfrm type offload\n", __func__);
	294	return -EAGAIN;
	295	}
	296
7785bba2 SK	297	return inet_add_offload(&esp4_offload, IPPROTO_ESP);
	298	}
	299
	300	static void __exit esp4_offload_exit(void)
	301	{
fca11ebd SK	302	if (xfrm_unregister_type_offload(&esp_type_offload, AF_INET) < 0)
	303	pr_info("%s: can't remove xfrm type offload\n", __func__);
	304
7785bba2 SK	305	inet_del_offload(&esp4_offload, IPPROTO_ESP);
	306	}
	307
	308	module_init(esp4_offload_init);
	309	module_exit(esp4_offload_exit);
	310	MODULE_LICENSE("GPL");
	311	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
ffdb5211	312	MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);