int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
{
int nexthdr;
int err = -ENOMEM;
struct ip_comp_hdr *ipch;
if (skb_linearize_cow(skb))
goto out;
skb->ip_summed = CHECKSUM_NONE;
ipch = (void *)skb->data;
nexthdr = ipch->nexthdr;
skb->transport_header = skb->network_header + sizeof(*ipch);
__skb_pull(skb, sizeof(*ipch));
err = ipcomp_decompress(x, skb);
if (err)
goto out;
err = nexthdr;
out:
return err;
}
static int ipcomp_input(struct xfrm_state *x,
struct xfrm_decap_state *decap, struct sk_buff *skb)
{
u8 nexthdr;
int err = 0;
struct iphdr *iph;
union {
struct iphdr iph;
char buf[60];
} tmp_iph;
if ((skb_is_nonlinear(skb) || skb_cloned(skb)) &&
skb_linearize(skb, GFP_ATOMIC) != 0) {
err = -ENOMEM;
goto out;
}
skb->ip_summed = CHECKSUM_NONE;
/* Remove ipcomp header and decompress original payload */
iph = skb->nh.iph;
memcpy(&tmp_iph, iph, iph->ihl * 4);
nexthdr = *(u8 *)skb->data;
skb_pull(skb, sizeof(struct ip_comp_hdr));
skb->nh.raw += sizeof(struct ip_comp_hdr);
memcpy(skb->nh.raw, &tmp_iph, tmp_iph.iph.ihl * 4);
iph = skb->nh.iph;
iph->tot_len = htons(ntohs(iph->tot_len) - sizeof(struct ip_comp_hdr));
iph->protocol = nexthdr;
skb->h.raw = skb->data;
err = ipcomp_decompress(x, skb);
out:
return err;
}
