1 files changed, 8 insertions, 0 deletions

diff --git a/include/net/route.h b/include/net/route.h
index 2ea40c1b5e00..afdeeb5bec25 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -317,4 +317,12 @@ static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
         return hoplimit;
 }
 
+static inline int ip_skb_dst_mtu(struct sk_buff *skb)
+{
+        struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL;
+
+        return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ?
+               skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb));
+}
+
 #endif  /* _ROUTE_H */