+ if (iph->protocol != IPPROTO_IPIP)
+ goto drop;
+ if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+ goto drop;
+ if (skb_cloned(skb) &&
+ pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ goto drop;
+ if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+ ipv4_copy_dscp(iph, skb->h.ipiph);
+ if (!(x->props.flags & XFRM_STATE_NOECN))
+ ipip_ecn_decapsulate(skb);
+ skb->mac.raw = memmove(skb->data - skb->mac_len,
+ skb->mac.raw, skb->mac_len);
+ skb->nh.raw = skb->data;
+ memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));