net/ipv6/esp6_offload.c - kernel/msm-5.4 - Gitiles

 /*
  * 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>");
	/*
	* 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>");