1 files changed, 41 insertions, 1 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 259cbeee9a8b..132737a7c83a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -965,7 +965,7 @@ void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
 }
 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
 
-void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
+static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 {
         const struct iphdr *iph = (const struct iphdr *) skb->data;
         struct flowi4 fl4;
@@ -978,6 +978,46 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
                 ip_rt_put(rt);
         }
 }
+
+void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
+{
+        const struct iphdr *iph = (const struct iphdr *) skb->data;
+        struct flowi4 fl4;
+        struct rtable *rt;
+        struct dst_entry *dst;
+
+        bh_lock_sock(sk);
+        rt = (struct rtable *) __sk_dst_get(sk);
+
+        if (sock_owned_by_user(sk) || !rt) {
+                __ipv4_sk_update_pmtu(skb, sk, mtu);
+                goto out;
+        }
+
+        __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
+
+        if (!__sk_dst_check(sk, 0)) {
+                rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
+                if (IS_ERR(rt))
+                        goto out;
+        }
+
+        __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
+
+        dst = dst_check(&rt->dst, 0);
+        if (!dst) {
+                rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
+                if (IS_ERR(rt))
+                        goto out;
+
+                dst = &rt->dst;
+        }
+
+         __sk_dst_set(sk, dst);
+
+out:
+        bh_unlock_sock(sk);
+}
 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
 
 void ipv4_redirect(struct sk_buff *skb, struct net *net,