007f0211a8
Current the x->mode->output functions store the IPv6 nh pointer in the skb network header. This is inconvenient because the network header then has to be fixed up before the packet can leave the IPsec stack. The mac header field is unused on output so we can use that to store this instead. This patch does that and removes the network header fix-up in xfrm_output. It also uses ipv6_hdr where appropriate in the x->type->output functions. There is also a minor clean-up in esp4 to make it use the same code as esp6 to help any subsequent effort to merge the two. Lastly it kills two redundant skb_set_* statements in BEET that were simply copied over from transport mode. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/*
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* xfrm6_mode_transport.c - Transport mode encapsulation for IPv6.
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*
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* Copyright (C) 2002 USAGI/WIDE Project
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* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
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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/dst.h>
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#include <net/ipv6.h>
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#include <net/xfrm.h>
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/* Add encapsulation header.
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*
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* The IP header and mutable extension headers will be moved forward to make
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* space for the encapsulation header.
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*
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* On exit, skb->h will be set to the start of the encapsulation header to be
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* filled in by x->type->output and the mac header will be set to the
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* nextheader field of the extension header directly preceding the
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* encapsulation header, or in its absence, that of the top IP header.
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* The value of skb->data and the network header will always point to the
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* top IP header.
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*/
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static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct ipv6hdr *iph;
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u8 *prevhdr;
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int hdr_len;
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skb_push(skb, x->props.header_len);
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iph = ipv6_hdr(skb);
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hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
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skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
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skb_reset_network_header(skb);
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skb_set_transport_header(skb, hdr_len);
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memmove(skb->data, iph, hdr_len);
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return 0;
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}
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/* Remove encapsulation header.
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*
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* The IP header will be moved over the top of the encapsulation header.
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*
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* On entry, skb->h shall point to where the IP header should be and skb->nh
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* shall be set to where the IP header currently is. skb->data shall point
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* to the start of the payload.
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*/
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static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
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{
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int ihl = skb->data - skb_transport_header(skb);
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if (skb->transport_header != skb->network_header) {
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memmove(skb_transport_header(skb),
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skb_network_header(skb), ihl);
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skb->network_header = skb->transport_header;
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}
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ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
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sizeof(struct ipv6hdr));
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skb_reset_transport_header(skb);
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return 0;
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}
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static struct xfrm_mode xfrm6_transport_mode = {
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.input = xfrm6_transport_input,
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.output = xfrm6_transport_output,
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.owner = THIS_MODULE,
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.encap = XFRM_MODE_TRANSPORT,
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};
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static int __init xfrm6_transport_init(void)
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{
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return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6);
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}
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static void __exit xfrm6_transport_exit(void)
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{
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int err;
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err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6);
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BUG_ON(err);
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}
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module_init(xfrm6_transport_init);
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module_exit(xfrm6_transport_exit);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT);
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