2 files changed, 12 insertions, 1 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index 4aa781b7f609..b885d75cede4 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -266,7 +266,8 @@ int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
 
 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
 {
-        return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE;
+        return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
+               inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
 }
 
 static inline bool ip_sk_use_pmtu(const struct sock *sk)
@@ -274,6 +275,12 @@ static inline bool ip_sk_use_pmtu(const struct sock *sk)
         return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
 }
 
+static inline bool ip_sk_local_df(const struct sock *sk)
+{
+        return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
+               inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
+}
+
 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
                                                     bool forwarding)
 {
diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index 393c5de09d42..c33a65e3d62c 100644
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -120,6 +120,10 @@ struct in_addr {
  * this socket to prevent accepting spoofed ones.
  */
 #define IP_PMTUDISC_INTERFACE           4
+/* weaker version of IP_PMTUDISC_INTERFACE, which allos packets to get
+ * fragmented if they exeed the interface mtu
+ */
+#define IP_PMTUDISC_OMIT                5
 
 #define IP_MULTICAST_IF                 32
 #define IP_MULTICAST_TTL                33