Add interface optional string for csum.

ovs/vswitch.go

@@ -274,6 +274,11 @@ type InterfaceOptions struct {
 	// tunneled traffic leaving this interface. Optionally it could be set to
 	// "flow" which expects the flow to set tunnel ID.
 	Key string
+
+	// Optionally compute encapsulation header (either GRE or UDP) checksums on
+	// outgoing packets. Default is false, set to true to enable. Checksums present
+	// on incoming packets will be validated regardless of this setting.
+	Csum string
 }
 
 // slice creates a string slice containing any non-zero option values from the
@@ -315,5 +320,9 @@ func (i InterfaceOptions) slice() []string {
 		s = append(s, fmt.Sprintf("options:key=%s", i.Key))
 	}
 
+	if i.Csum != "" {
+		s = append(s, fmt.Sprintf("options:csum=%s", i.Csum))
+	}
+
 	return s
 }

ovs/vswitch_test.go

@@ -857,6 +857,21 @@ func TestInterfaceOptions_slice(t *testing.T) {
 				"options:key=flow",
 			},
 		},
+		{
+			desc: "flow based VXLAN tunnel",
+			i: InterfaceOptions{
+				Type:     InterfaceTypeVXLAN,
+				RemoteIP: "flow",
+				Key:      "flow",
+				Csum:     "true",
+			},
+			out: []string{
+				"type=vxlan",
+				"options:remote_ip=flow",
+				"options:key=flow",
+				"options:csum=true",
+			},
+		},
 		{
 			desc: "all options",
 			i: InterfaceOptions{