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awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/net/ipv6/xfrm6_mode_beet.c
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/*

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 * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.

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 *

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 * Copyright (c) 2006 Diego Beltrami <[email protected]>

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 *                    Miika Komu     <[email protected]>

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 *                    Herbert Xu     <[email protected]>

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 *                    Abhinav Pathak <[email protected]>

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 *                    Jeff Ahrenholz <[email protected]>

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 */

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#include <linux/init.h>

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#include <linux/kernel.h>

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#include <linux/module.h>

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#include <linux/skbuff.h>

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#include <linux/stringify.h>

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#include <net/dsfield.h>

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#include <net/dst.h>

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#include <net/inet_ecn.h>

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#include <net/ipv6.h>

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#include <net/xfrm.h>

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static void xfrm6_beet_make_header(struct sk_buff *skb)

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{

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	struct ipv6hdr *iph = ipv6_hdr(skb);

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	iph->version = 6;

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	memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,

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	       sizeof(iph->flow_lbl));

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	iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;

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	ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos);

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	iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;

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}

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/* Add encapsulation header.

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 *

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 * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.

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 */

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static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)

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{

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	struct ipv6hdr *top_iph;

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	struct ip_beet_phdr *ph;

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	int optlen, hdr_len;

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	hdr_len = 0;

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	optlen = XFRM_MODE_SKB_CB(skb)->optlen;

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	if (unlikely(optlen))

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		hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);

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	skb_set_network_header(skb, -x->props.header_len - hdr_len);

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	if (x->sel.family != AF_INET6)

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		skb->network_header += IPV4_BEET_PHMAXLEN;

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	skb->mac_header = skb->network_header +

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			  offsetof(struct ipv6hdr, nexthdr);

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	skb->transport_header = skb->network_header + sizeof(*top_iph);

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	ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len);

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	xfrm6_beet_make_header(skb);

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	top_iph = ipv6_hdr(skb);

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	if (unlikely(optlen)) {

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		BUG_ON(optlen < 0);

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		ph->padlen = 4 - (optlen & 4);

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		ph->hdrlen = optlen / 8;

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		ph->nexthdr = top_iph->nexthdr;

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		if (ph->padlen)

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			memset(ph + 1, IPOPT_NOP, ph->padlen);

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		top_iph->nexthdr = IPPROTO_BEETPH;

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	}

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	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);

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	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);

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	return 0;

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}

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static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)

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{

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	struct ipv6hdr *ip6h;

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	const unsigned char *old_mac;

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	int size = sizeof(struct ipv6hdr);

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	int err;

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	err = skb_cow_head(skb, size + skb->mac_len);

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	if (err)

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		goto out;

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	__skb_push(skb, size);

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	skb_reset_network_header(skb);

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	old_mac = skb_mac_header(skb);

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	skb_set_mac_header(skb, -skb->mac_len);

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	memmove(skb_mac_header(skb), old_mac, skb->mac_len);

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	xfrm6_beet_make_header(skb);

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	ip6h = ipv6_hdr(skb);

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	ip6h->payload_len = htons(skb->len - size);

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	ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);

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	ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);

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	err = 0;

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out:

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	return err;

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}

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static struct xfrm_mode xfrm6_beet_mode = {

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	.input2 = xfrm6_beet_input,

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	.input = xfrm_prepare_input,

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	.output2 = xfrm6_beet_output,

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	.output = xfrm6_prepare_output,

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	.owner = THIS_MODULE,

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	.encap = XFRM_MODE_BEET,

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	.flags = XFRM_MODE_FLAG_TUNNEL,

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};

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static int __init xfrm6_beet_init(void)

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{

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	return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);

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}

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static void __exit xfrm6_beet_exit(void)

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{

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	int err;

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	err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);

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	BUG_ON(err);

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}

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module_init(xfrm6_beet_init);

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module_exit(xfrm6_beet_exit);

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MODULE_LICENSE("GPL");

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MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);

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