Merge release-20200818.0-83-gbdd5996a7 (automated)

1 files changed, 16 insertions, 0 deletions

diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index cd72d4f02..47a8d7c86 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -841,10 +841,26 @@ const (
 	PMTUDiscoveryProbe
 )
 
+// GettableNetworkProtocolOption is a marker interface for network protocol
+// options that may be queried.
+type GettableNetworkProtocolOption interface {
+	isGettableNetworkProtocolOption()
+}
+
+// SettableNetworkProtocolOption is a marker interface for network protocol
+// options that may be set.
+type SettableNetworkProtocolOption interface {
+	isSettableNetworkProtocolOption()
+}
+
 // DefaultTTLOption is used by stack.(*Stack).NetworkProtocolOption to specify
 // a default TTL.
 type DefaultTTLOption uint8
 
+func (*DefaultTTLOption) isGettableNetworkProtocolOption() {}
+
+func (*DefaultTTLOption) isSettableNetworkProtocolOption() {}
+
 // AvailableCongestionControlOption is used to query the supported congestion
 // control algorithms.
 type AvailableCongestionControlOption string