Handle FAR flags for Buffer and notify CP (#202)

Co-authored-by: badhri85 <badhri85@node.onf2.cord-testdrive-pg0.wisc.cloudlab.us>
Co-authored-by: Saikrishna Edupuganti <krsna1729@users.noreply.github.com>

conf/up4.bess

@@ -23,6 +23,7 @@ GTPUEncap = 1
 farForwardUAction = 0
 farForwardDAction = 1
 farDropAction = 2
+farBufferAction = 3
 farNotifyCPAction = 4
 pdrFailGate = 2
 farFailGate = 2
@@ -216,6 +217,7 @@ pdrLookup:pdrFailGate -> pdrLookupFail::Sink()
 farLookup:farFailGate -> farLookupFail::Sink()
 executeFAR:farDropAction -> farDrop::Sink()
 executeFAR:farNotifyCPAction -> farNotifyCP::Sink()
+executeFAR:farBufferAction -> farBuffer::Sink()
 gtpuEncap:0 -> gtpuEncapFail::Sink()
 
 # Set default gates for relevant modules

pfcpiface/bess.go

@@ -417,7 +417,8 @@ func (b *bess) sim(u *upf, method string) {
 			farID: n3,
 			fseID: n3TEID + i,
 
-			action:       farForwardD,
+			applyAction:  Action_Forward,
+			dstIntf:      access,
 			tunnelType:   0x1,
 			tunnelIP4Src: ip2int(u.accessIP),
 			tunnelIP4Dst: ip2int(enbip) + enbIdx,
@@ -430,14 +431,16 @@ func (b *bess) sim(u *upf, method string) {
 			farID: n6,
 			fseID: n3TEID + i,
 
-			action: farForwardU,
+			applyAction: Action_Forward,
+			dstIntf:     core,
 		}
 
 		farN9Up := far{
 			farID: n9,
 			fseID: n3TEID + i,
 
-			action:       farForwardU,
+			applyAction:  Action_Forward,
+			dstIntf:      core,
 			tunnelType:   0x1,
 			tunnelIP4Src: ip2int(u.coreIP),
 			tunnelIP4Dst: ip2int(aupfip),
@@ -641,15 +644,15 @@ func (b *bess) addFAR(ctx context.Context, done chan<- bool, far far) {
 	go func() {
 		var any *anypb.Any
 		var err error
-
+		var action uint8 = far.setActionValue()
 		f := &pb.ExactMatchCommandAddArg{
 			Gate: uint64(far.tunnelType),
 			Fields: []*pb.FieldData{
 				intEnc(uint64(far.farID)), /* far_id */
 				intEnc(uint64(far.fseID)), /* fseid */
 			},
 			Values: []*pb.FieldData{
-				intEnc(uint64(far.action)),       /* action */
+				intEnc(uint64(action)),           /* action */
 				intEnc(uint64(far.tunnelType)),   /* tunnel_out_type */
 				intEnc(uint64(far.tunnelIP4Src)), /* access-ip */
 				intEnc(uint64(far.tunnelIP4Dst)), /* enb ip */

pfcpiface/parse-far.go

@@ -17,6 +17,13 @@ const (
 	FwdIE_DestinationIntf
 )
 
+const (
+	Action_Forward = 0x2
+	Action_Drop    = 0x1
+	Action_Buffer  = 0x4
+	Action_Notify  = 0x8
+)
+
 const (
 	create operation = iota
 	update
@@ -27,7 +34,7 @@ type far struct {
 	fseID   uint32
 	fseidIP uint32
 
-	action       uint8
+	dstIntf      uint8
 	applyAction  uint8
 	tunnelType   uint8
 	tunnelIP4Src uint32
@@ -41,7 +48,7 @@ func (f *far) printFAR() {
 	log.Println("FAR ID:", f.farID)
 	log.Println("fseID:", f.fseID)
 	log.Println("fseIDIP:", f.fseidIP)
-	log.Println("action:", f.action)
+	log.Println("dstIntf:", f.dstIntf)
 	log.Println("applyAction:", f.applyAction)
 	log.Println("tunnelType:", f.tunnelType)
 	log.Println("tunnelIP4Src:", f.tunnelIP4Src)
@@ -51,6 +58,31 @@ func (f *far) printFAR() {
 	log.Println("--------------------------------------------")
 }
 
+func (f *far) setActionValue() uint8 {
+	if (f.applyAction & Action_Forward) != 0 {
+		if f.dstIntf == ie.DstInterfaceAccess {
+			log.Println("Set Action forwardD")
+			return farForwardD
+		} else if f.dstIntf == ie.DstInterfaceCore {
+			log.Println("Set Action forwardU")
+			return farForwardU
+		}
+	} else if (f.applyAction & Action_Drop) != 0 {
+		log.Println("Set Action drop")
+		return farDrop
+	} else if (f.applyAction & Action_Buffer) != 0 {
+		log.Println("Set Action buffer")
+		return farBuffer
+	} else if (f.applyAction & Action_Notify) != 0 {
+		log.Println("Set Action notify")
+		return farNotify
+	}
+
+	//default action
+	log.Println("Set Action drop default")
+	return farDrop
+}
+
 func (f *far) parseFAR(farIE *ie.IE, fseid uint64, upf *upf, op operation) error {
 	f.fseID = uint32(fseid)
 
@@ -65,13 +97,6 @@ func (f *far) parseFAR(farIE *ie.IE, fseid uint64, upf *upf, op operation) error
 		return err
 	}
 
-	if (action&0x02)>>1 == 0 {
-		log.Println("Handling forward action only")
-		// TODO: Handle buffer
-		f.action = farDrop
-		return nil
-	}
-
 	f.applyAction = action
 	var fwdIEs []*ie.IE
 
@@ -104,16 +129,14 @@ func (f *far) parseFAR(farIE *ie.IE, fseid uint64, upf *upf, op operation) error
 			f.tunnelPort = tunnelGTPUPort
 		case ie.DestinationInterface:
 			fields = Set(fields, FwdIE_DestinationIntf)
-			dstIface, err := fwdIE.DestinationInterface()
+			f.dstIntf, err = fwdIE.DestinationInterface()
 			if err != nil {
 				log.Println("Unable to parse DestinationInterface field")
 				continue
 			}
-			if dstIface == ie.DstInterfaceAccess {
-				f.action = farForwardD
+			if f.dstIntf == ie.DstInterfaceAccess {
 				f.tunnelIP4Src = ip2int(upf.accessIP)
-			} else if dstIface == ie.DstInterfaceCore {
-				f.action = farForwardU
+			} else if f.dstIntf == ie.DstInterfaceCore {
 				f.tunnelIP4Src = ip2int(upf.coreIP)
 			}
 		}

pfcpiface/upf.go

@@ -38,6 +38,8 @@ const (
 	farForwardU = 0x0
 	farForwardD = 0x1
 	farDrop     = 0x2
+	farBuffer   = 0x3
+	farNotify   = 0x4
 )
 
 func (u *upf) sendMsgToUPF(method string, pdrs []pdr, fars []far) uint8 {