From 0b13bbd8a4977c4355dab0e9a533ac6574d66ed2 Mon Sep 17 00:00:00 2001
From: ianchen0119 <ychen.desl@gmail.com>
Date: Wed, 14 Sep 2022 05:41:26 +0000
Subject: [PATCH] The DLFAR of pfcp session est req must includes
 forwardingParameter

---
 internal/context/datapath.go   |  9 +++++----
 internal/pfcp/message/build.go | 12 +++++++++++-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/internal/context/datapath.go b/internal/context/datapath.go
index 9a533e2a..6264d35d 100644
--- a/internal/context/datapath.go
+++ b/internal/context/datapath.go
@@ -528,11 +528,12 @@ func (dataPath *DataPath) ActivateTunnelAndPDR(smContext *SMContext, precedence
 					}
 				}
 			} else {
+				ANUPF := dataPath.FirstDPNode
+				DLPDR := ANUPF.DownLinkTunnel.PDR
+				DLFAR := DLPDR.FAR
+				DLFAR.ForwardingParameters = new(ForwardingParameters)
+				DLFAR.ForwardingParameters.DestinationInterface.InterfaceValue = pfcpType.DestinationInterfaceAccess
 				if anIP := smContext.Tunnel.ANInformation.IPAddress; anIP != nil {
-					ANUPF := dataPath.FirstDPNode
-					DLPDR := ANUPF.DownLinkTunnel.PDR
-					DLFAR := DLPDR.FAR
-					DLFAR.ForwardingParameters = new(ForwardingParameters)
 					DLFAR.ForwardingParameters.DestinationInterface.InterfaceValue = pfcpType.DestinationInterfaceAccess
 					DLFAR.ForwardingParameters.NetworkInstance = &pfcpType.NetworkInstance{NetworkInstance: smContext.Dnn}
 					DLFAR.ForwardingParameters.OuterHeaderCreation = new(pfcpType.OuterHeaderCreation)
diff --git a/internal/pfcp/message/build.go b/internal/pfcp/message/build.go
index a1da60b1..2c70caca 100644
--- a/internal/pfcp/message/build.go
+++ b/internal/pfcp/message/build.go
@@ -111,7 +111,17 @@ func farToCreateFAR(far *context.FAR) *pfcp.CreateFAR {
 	createFAR.FARID.FarIdValue = far.FARID
 
 	createFAR.ApplyAction = new(pfcpType.ApplyAction)
-	createFAR.ApplyAction.Forw = true
+	if far.ForwardingParameters != nil {
+		createFAR.ApplyAction.Forw = true
+	} else {
+		/*
+			29.244 v15.3 Table 7.5.2.3-1
+			Farwarding Parameters IE shall be present when the Apply-Action requests the packets to be forwarded.
+		*/
+		// FAR without Farwarding Parameters set Apply Action as Drop instead of Forward.
+		createFAR.ApplyAction.Forw = false
+		createFAR.ApplyAction.Drop = true
+	}
 
 	if far.BAR != nil {
 		createFAR.BARID = new(pfcpType.BARID)