Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * xfrm4_mode_transport.c - Transport mode encapsulation for IPv4.

 *

 * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>

 */

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/skbuff.h>

#include <linux/stringify.h>

#include <net/dst.h>

#include <net/ip.h>

#include <net/xfrm.h>

/* Add encapsulation header.

 *

 * The IP header will be moved forward to make space for the encapsulation

 * header.

 */

static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)

{

        struct iphdr *iph = ip_hdr(skb);

        int ihl = iph->ihl * 4;

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

        skb->mac_header = skb->network_header +

                          offsetof(struct iphdr, protocol);

        skb->transport_header = skb->network_header + ihl;

        __skb_pull(skb, ihl);

        memmove(skb_network_header(skb), iph, ihl);

        return 0;

}

/* Remove encapsulation header.

 *

 * The IP header will be moved over the top of the encapsulation header.

 *

 * On entry, skb->h shall point to where the IP header should be and skb->nh

 * shall be set to where the IP header currently is.  skb->data shall point

 * to the start of the payload.

 */

static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)

{

        int ihl = skb->data - skb_transport_header(skb);

        if (skb->transport_header != skb->network_header) {

                memmove(skb_transport_header(skb),

                        skb_network_header(skb), ihl);

                skb->network_header = skb->transport_header;

        }

        ip_hdr(skb)->tot_len = htons(skb->len + ihl);

        skb_reset_transport_header(skb);

        return 0;

}

static struct xfrm_mode xfrm4_transport_mode = {

        .input = xfrm4_transport_input,

        .output = xfrm4_transport_output,

        .owner = THIS_MODULE,

        .encap = XFRM_MODE_TRANSPORT,

};

static int __init xfrm4_transport_init(void)

{

        return xfrm_register_mode(&xfrm4_transport_mode, AF_INET);

}

static void __exit xfrm4_transport_exit(void)

{

        int err;

        err = xfrm_unregister_mode(&xfrm4_transport_mode, AF_INET);

        BUG_ON(err);

}

module_init(xfrm4_transport_init);

module_exit(xfrm4_transport_exit);

MODULE_LICENSE("GPL");

MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TRANSPORT);