310 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			310 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * IPV6 GSO/GRO offload support
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|  * Linux INET implementation
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|  *
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|  * Copyright (C) 2016 secunet Security Networks AG
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|  * Author: Steffen Klassert <steffen.klassert@secunet.com>
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|  *
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|  * This program is free software; you can redistribute it and/or modify it
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|  * under the terms and conditions of the GNU General Public License,
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|  * version 2, as published by the Free Software Foundation.
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|  *
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|  * ESP GRO support
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|  */
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| 
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| #include <linux/skbuff.h>
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| #include <linux/init.h>
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| #include <net/protocol.h>
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| #include <crypto/aead.h>
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| #include <crypto/authenc.h>
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| #include <linux/err.h>
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| #include <linux/module.h>
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| #include <net/ip.h>
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| #include <net/xfrm.h>
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| #include <net/esp.h>
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| #include <linux/scatterlist.h>
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| #include <linux/kernel.h>
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| #include <linux/slab.h>
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| #include <linux/spinlock.h>
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| #include <net/ip6_route.h>
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| #include <net/ipv6.h>
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| #include <linux/icmpv6.h>
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| 
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| static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
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| {
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| 	int off = sizeof(struct ipv6hdr);
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| 	struct ipv6_opt_hdr *exthdr;
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| 
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| 	if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP))
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| 		return offsetof(struct ipv6hdr, nexthdr);
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| 
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| 	while (off < nhlen) {
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| 		exthdr = (void *)ipv6_hdr + off;
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| 		if (exthdr->nexthdr == NEXTHDR_ESP)
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| 			return off;
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| 
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| 		off += ipv6_optlen(exthdr);
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static struct sk_buff *esp6_gro_receive(struct list_head *head,
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| 					struct sk_buff *skb)
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| {
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| 	int offset = skb_gro_offset(skb);
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| 	struct xfrm_offload *xo;
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| 	struct xfrm_state *x;
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| 	__be32 seq;
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| 	__be32 spi;
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| 	int nhoff;
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| 	int err;
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| 
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| 	if (!pskb_pull(skb, offset))
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| 		return NULL;
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| 
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| 	if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
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| 		goto out;
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| 
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| 	xo = xfrm_offload(skb);
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| 	if (!xo || !(xo->flags & CRYPTO_DONE)) {
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| 		err = secpath_set(skb);
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| 		if (err)
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| 			goto out;
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| 
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| 		if (skb->sp->len == XFRM_MAX_DEPTH)
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| 			goto out;
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| 
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| 		x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
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| 				      (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
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| 				      spi, IPPROTO_ESP, AF_INET6);
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| 		if (!x)
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| 			goto out;
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| 
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| 		skb->sp->xvec[skb->sp->len++] = x;
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| 		skb->sp->olen++;
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| 
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| 		xo = xfrm_offload(skb);
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| 		if (!xo) {
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| 			xfrm_state_put(x);
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| 			goto out;
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| 		}
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| 	}
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| 
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| 	xo->flags |= XFRM_GRO;
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| 
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| 	nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
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| 	if (!nhoff)
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| 		goto out;
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| 
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| 	IP6CB(skb)->nhoff = nhoff;
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| 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
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| 	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
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| 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
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| 	XFRM_SPI_SKB_CB(skb)->seq = seq;
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| 
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| 	/* We don't need to handle errors from xfrm_input, it does all
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| 	 * the error handling and frees the resources on error. */
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| 	xfrm_input(skb, IPPROTO_ESP, spi, -2);
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| 
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| 	return ERR_PTR(-EINPROGRESS);
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| out:
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| 	skb_push(skb, offset);
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| 	NAPI_GRO_CB(skb)->same_flow = 0;
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| 	NAPI_GRO_CB(skb)->flush = 1;
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| 
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| 	return NULL;
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| }
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| 
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| static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
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| {
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| 	struct ip_esp_hdr *esph;
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| 	struct ipv6hdr *iph = ipv6_hdr(skb);
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| 	struct xfrm_offload *xo = xfrm_offload(skb);
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| 	int proto = iph->nexthdr;
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| 
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| 	skb_push(skb, -skb_network_offset(skb));
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| 	esph = ip_esp_hdr(skb);
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| 	*skb_mac_header(skb) = IPPROTO_ESP;
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| 
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| 	esph->spi = x->id.spi;
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| 	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
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| 
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| 	xo->proto = proto;
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| }
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| 
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| static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
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| 				        netdev_features_t features)
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| {
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| 	struct xfrm_state *x;
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| 	struct ip_esp_hdr *esph;
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| 	struct crypto_aead *aead;
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| 	netdev_features_t esp_features = features;
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| 	struct xfrm_offload *xo = xfrm_offload(skb);
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| 
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| 	if (!xo)
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| 		return ERR_PTR(-EINVAL);
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| 
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| 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
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| 		return ERR_PTR(-EINVAL);
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| 
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| 	x = skb->sp->xvec[skb->sp->len - 1];
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| 	aead = x->data;
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| 	esph = ip_esp_hdr(skb);
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| 
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| 	if (esph->spi != x->id.spi)
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| 		return ERR_PTR(-EINVAL);
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| 
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| 	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
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| 		return ERR_PTR(-EINVAL);
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| 
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| 	__skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
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| 
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| 	skb->encap_hdr_csum = 1;
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| 
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| 	if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
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| 		esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
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| 	else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
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| 		esp_features = features & ~NETIF_F_CSUM_MASK;
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| 
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| 	xo->flags |= XFRM_GSO_SEGMENT;
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| 
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| 	return x->outer_mode->gso_segment(x, skb, esp_features);
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| }
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| 
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| static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
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| {
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| 	struct crypto_aead *aead = x->data;
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| 	struct xfrm_offload *xo = xfrm_offload(skb);
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| 
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| 	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
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| 		return -EINVAL;
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| 
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| 	if (!(xo->flags & CRYPTO_DONE))
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| 		skb->ip_summed = CHECKSUM_NONE;
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| 
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| 	return esp6_input_done2(skb, 0);
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| }
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| 
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| static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_t features)
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| {
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| 	int len;
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| 	int err;
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| 	int alen;
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| 	int blksize;
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| 	struct xfrm_offload *xo;
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| 	struct ip_esp_hdr *esph;
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| 	struct crypto_aead *aead;
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| 	struct esp_info esp;
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| 	bool hw_offload = true;
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| 	__u32 seq;
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| 
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| 	esp.inplace = true;
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| 
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| 	xo = xfrm_offload(skb);
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| 
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| 	if (!xo)
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| 		return -EINVAL;
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| 
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| 	if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
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| 		xo->flags |= CRYPTO_FALLBACK;
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| 		hw_offload = false;
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| 	}
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| 
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| 	esp.proto = xo->proto;
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| 
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| 	/* skb is pure payload to encrypt */
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| 
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| 	aead = x->data;
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| 	alen = crypto_aead_authsize(aead);
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| 
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| 	esp.tfclen = 0;
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| 	/* XXX: Add support for tfc padding here. */
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| 
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| 	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
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| 	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
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| 	esp.plen = esp.clen - skb->len - esp.tfclen;
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| 	esp.tailen = esp.tfclen + esp.plen + alen;
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| 
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| 	if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
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| 		esp.nfrags = esp6_output_head(x, skb, &esp);
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| 		if (esp.nfrags < 0)
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| 			return esp.nfrags;
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| 	}
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| 
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| 	seq = xo->seq.low;
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| 
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| 	esph = ip_esp_hdr(skb);
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| 	esph->spi = x->id.spi;
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| 
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| 	skb_push(skb, -skb_network_offset(skb));
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| 
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| 	if (xo->flags & XFRM_GSO_SEGMENT) {
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| 		esph->seq_no = htonl(seq);
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| 
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| 		if (!skb_is_gso(skb))
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| 			xo->seq.low++;
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| 		else
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| 			xo->seq.low += skb_shinfo(skb)->gso_segs;
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| 	}
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| 
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| 	esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
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| 
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| 	len = skb->len - sizeof(struct ipv6hdr);
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| 	if (len > IPV6_MAXPLEN)
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| 		len = 0;
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| 
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| 	ipv6_hdr(skb)->payload_len = htons(len);
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| 
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| 	if (hw_offload)
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| 		return 0;
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| 
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| 	err = esp6_output_tail(x, skb, &esp);
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| 	if (err)
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| 		return err;
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| 
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| 	secpath_reset(skb);
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| 
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| 	return 0;
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| }
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| 
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| static const struct net_offload esp6_offload = {
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| 	.callbacks = {
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| 		.gro_receive = esp6_gro_receive,
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| 		.gso_segment = esp6_gso_segment,
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| 	},
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| };
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| 
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| static const struct xfrm_type_offload esp6_type_offload = {
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| 	.description	= "ESP6 OFFLOAD",
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| 	.owner		= THIS_MODULE,
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| 	.proto	     	= IPPROTO_ESP,
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| 	.input_tail	= esp6_input_tail,
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| 	.xmit		= esp6_xmit,
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| 	.encap		= esp6_gso_encap,
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| };
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| 
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| static int __init esp6_offload_init(void)
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| {
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| 	if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
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| 		pr_info("%s: can't add xfrm type offload\n", __func__);
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| 		return -EAGAIN;
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| 	}
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| 
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| 	return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
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| }
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| 
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| static void __exit esp6_offload_exit(void)
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| {
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| 	if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0)
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| 		pr_info("%s: can't remove xfrm type offload\n", __func__);
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| 
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| 	inet6_del_offload(&esp6_offload, IPPROTO_ESP);
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| }
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| 
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| module_init(esp6_offload_init);
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| module_exit(esp6_offload_exit);
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| MODULE_LICENSE("GPL");
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| MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
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| MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);
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