static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct iphdr *iph;
int optlen = 0;
int err = -EINVAL;
if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
struct ip_beet_phdr *ph;
int phlen;
if (!pskb_may_pull(skb, sizeof(*ph)))
goto out;
ph = (struct ip_beet_phdr *)skb->data;
phlen = sizeof(*ph) + ph->padlen;
optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
if (optlen < 0 || optlen & 3 || optlen > 250)
goto out;
XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;
if (!pskb_may_pull(skb, phlen))
goto out;
__skb_pull(skb, phlen);
}
skb_push(skb, sizeof(*iph));
skb_reset_network_header(skb);
memmove(skb->data - skb->mac_len, skb_mac_header(skb),
skb->mac_len);
skb_set_mac_header(skb, -skb->mac_len);
xfrm4_beet_make_header(skb);
iph = ip_hdr(skb);
iph->ihl += optlen / 4;
iph->tot_len = htons(skb->len);
iph->daddr = x->sel.daddr.a4;
iph->saddr = x->sel.saddr.a4;
iph->check = 0;
iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
err = 0;
out:
return err;
}
/* Add encapsulation header.
*
* The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
*/
static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct ip_beet_phdr *ph;
struct iphdr *top_iph;
int hdrlen, optlen;
hdrlen = 0;
optlen = XFRM_MODE_SKB_CB(skb)->optlen;
if (unlikely(optlen))
hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
skb_set_network_header(skb, -x->props.header_len -
hdrlen + (XFRM_MODE_SKB_CB(skb)->ihl - sizeof(*top_iph)));
if (x->sel.family != AF_INET6)
skb->network_header += IPV4_BEET_PHMAXLEN;
skb->mac_header = skb->network_header +
offsetof(struct iphdr, protocol);
skb->transport_header = skb->network_header + sizeof(*top_iph);
xfrm4_beet_make_header(skb);
ph = (struct ip_beet_phdr *)
__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdrlen);
top_iph = ip_hdr(skb);
if (unlikely(optlen)) {
BUG_ON(optlen < 0);
ph->padlen = 4 - (optlen & 4);
ph->hdrlen = optlen / 8;
ph->nexthdr = top_iph->protocol;
if (ph->padlen)
memset(ph + 1, IPOPT_NOP, ph->padlen);
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;
}
