skb->dev = dst->dev; 
static int xfrm6_tunnel_check_size(struct sk_buff *skb){	int mtu, ret = 0;	struct dst_entry *dst = skb->dst;	mtu = dst_mtu(dst);	if (mtu < IPV6_MIN_MTU)		mtu = IPV6_MIN_MTU;	if (skb->len > mtu) {		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);		ret = -EMSGSIZE;	}	return ret;}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/180e42503300629692b513daeb55a6bb0b51500c/xfrm6_output.c/clean/net/ipv6/xfrm6_output.c