185 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
187 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
203 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
271 	unsigned int mtu;  in ip6_skb_dst_mtu()  local
274 		mtu = READ_ONCE(dst->dev->mtu);  in ip6_skb_dst_mtu()
275 		mtu -= lwtunnel_headroom(dst->lwtstate, mtu);  in ip6_skb_dst_mtu()
277 		mtu = dst_mtu(dst);  in ip6_skb_dst_mtu()
279 	return mtu;  in ip6_skb_dst_mtu()
323 	unsigned int mtu;  in ip6_dst_mtu_maybe_forward()  local
326 		mtu = dst_metric_raw(dst, RTAX_MTU);  in ip6_dst_mtu_maybe_forward()
327 		if (mtu)  in ip6_dst_mtu_maybe_forward()
331 	mtu = IPV6_MIN_MTU;  in ip6_dst_mtu_maybe_forward()
335 		mtu = idev->cnf.mtu6;  in ip6_dst_mtu_maybe_forward()
339 	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);  in ip6_dst_mtu_maybe_forward()