140 строки
3.3 KiB
C
140 строки
3.3 KiB
C
/*
|
|
* xfrm4_mode_beet.c - BEET mode encapsulation for IPv4.
|
|
*
|
|
* Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
|
|
* Miika Komu <miika@iki.fi>
|
|
* Herbert Xu <herbert@gondor.apana.org.au>
|
|
* Abhinav Pathak <abhinav.pathak@hiit.fi>
|
|
* Jeff Ahrenholz <ahrenholz@gmail.com>
|
|
*/
|
|
|
|
#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 top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
|
|
* The following fields in it shall be filled in by x->type->output:
|
|
* tot_len
|
|
* check
|
|
*
|
|
* On exit, skb->h will be set to the start of the payload to be processed
|
|
* by x->type->output and skb->nh will be set to the top IP header.
|
|
*/
|
|
static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
struct iphdr *iph, *top_iph = NULL;
|
|
int hdrlen, optlen;
|
|
|
|
iph = skb->nh.iph;
|
|
skb->h.ipiph = iph;
|
|
|
|
hdrlen = 0;
|
|
optlen = iph->ihl * 4 - sizeof(*iph);
|
|
if (unlikely(optlen))
|
|
hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
|
|
|
|
skb->nh.raw = skb_push(skb, x->props.header_len + hdrlen);
|
|
top_iph = skb->nh.iph;
|
|
hdrlen = iph->ihl * 4 - optlen;
|
|
skb->h.raw += hdrlen;
|
|
|
|
memmove(top_iph, iph, hdrlen);
|
|
if (unlikely(optlen)) {
|
|
struct ip_beet_phdr *ph;
|
|
|
|
BUG_ON(optlen < 0);
|
|
|
|
ph = (struct ip_beet_phdr *)skb->h.raw;
|
|
ph->padlen = 4 - (optlen & 4);
|
|
ph->hdrlen = (optlen + ph->padlen + sizeof(*ph)) / 8;
|
|
ph->nexthdr = top_iph->protocol;
|
|
|
|
top_iph->protocol = IPPROTO_BEETPH;
|
|
top_iph->ihl = sizeof(struct iphdr) / 4;
|
|
}
|
|
|
|
top_iph->saddr = x->props.saddr.a4;
|
|
top_iph->daddr = x->id.daddr.a4;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
struct iphdr *iph = skb->nh.iph;
|
|
int phlen = 0;
|
|
int optlen = 0;
|
|
__u8 ph_nexthdr = 0, protocol = 0;
|
|
int err = -EINVAL;
|
|
|
|
protocol = iph->protocol;
|
|
|
|
if (unlikely(iph->protocol == IPPROTO_BEETPH)) {
|
|
struct ip_beet_phdr *ph = (struct ip_beet_phdr*)(iph + 1);
|
|
|
|
if (!pskb_may_pull(skb, sizeof(*ph)))
|
|
goto out;
|
|
|
|
phlen = ph->hdrlen * 8;
|
|
optlen = phlen - ph->padlen - sizeof(*ph);
|
|
if (optlen < 0 || optlen & 3 || optlen > 250)
|
|
goto out;
|
|
|
|
if (!pskb_may_pull(skb, phlen))
|
|
goto out;
|
|
|
|
ph_nexthdr = ph->nexthdr;
|
|
}
|
|
|
|
skb_push(skb, sizeof(*iph) - phlen + optlen);
|
|
memmove(skb->data, skb->nh.raw, sizeof(*iph));
|
|
skb->nh.raw = skb->data;
|
|
|
|
iph = skb->nh.iph;
|
|
iph->ihl = (sizeof(*iph) + optlen) / 4;
|
|
iph->tot_len = htons(skb->len);
|
|
iph->daddr = x->sel.daddr.a4;
|
|
iph->saddr = x->sel.saddr.a4;
|
|
if (ph_nexthdr)
|
|
iph->protocol = ph_nexthdr;
|
|
else
|
|
iph->protocol = protocol;
|
|
iph->check = 0;
|
|
iph->check = ip_fast_csum(skb->nh.raw, iph->ihl);
|
|
err = 0;
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static struct xfrm_mode xfrm4_beet_mode = {
|
|
.input = xfrm4_beet_input,
|
|
.output = xfrm4_beet_output,
|
|
.owner = THIS_MODULE,
|
|
.encap = XFRM_MODE_BEET,
|
|
};
|
|
|
|
static int __init xfrm4_beet_init(void)
|
|
{
|
|
return xfrm_register_mode(&xfrm4_beet_mode, AF_INET);
|
|
}
|
|
|
|
static void __exit xfrm4_beet_exit(void)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm_unregister_mode(&xfrm4_beet_mode, AF_INET);
|
|
BUG_ON(err);
|
|
}
|
|
|
|
module_init(xfrm4_beet_init);
|
|
module_exit(xfrm4_beet_exit);
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_BEET);
|