fix e2e admission sending messages

go/cs/reservation/e2e/response.go

@@ -52,6 +52,11 @@ func NewResponse(ts time.Time, id *reservation.E2EID, idx reservation.IndexNumbe
 	}, nil
 }
 
+// IsHopByHop returns false, as all the responses travel directly to the source endhost.
+func (r *Response) IsHopByHop() bool {
+	return false
+}
+
 // ResponseSetupSuccess is the response to a success setup. It's sent on the reverse direction.
 type ResponseSetupSuccess struct {
 	Response

go/cs/reservation/request.go

@@ -40,6 +40,11 @@ func (m *RequestMetadata) Path() *spath.Path {
 	return &m.path
 }
 
+// IsHopByHop returns true. If a subtype needs not to be hop by hop, it can override the function.
+func (m *RequestMetadata) IsHopByHop() bool {
+	return true
+}
+
 // NumberOfHops returns the number of hops in this reservation.
 func (m *RequestMetadata) NumberOfHops() int {
 	return (len(m.path.Raw) - spath.InfoFieldLength) / spath.HopFieldLength

go/cs/reservation/types.go

@@ -31,5 +31,6 @@ type Capacities interface {
 // MessageWithPath is used to send messages from the COLIBRI service via the BR.
 type MessageWithPath interface {
 	Path() *spath.Path
+	IsHopByHop() bool
 	// Payload() []byte
 }

go/cs/reservationstore/store.go

@@ -286,29 +286,15 @@ func (s *Store) AdmitE2EReservation(ctx context.Context, request e2e.SetupReques
 	if err := s.validateAuthenticators(&req.RequestMetadata); err != nil {
 		return nil, serrors.WrapStr("error validating e2e request", err, "id", req.ID)
 	}
+	response, err := s.prepareFailureE2EResp(&req.Request)
+	if err != nil {
+		return nil, serrors.WrapStr("cannot construct response", err, "id", req.ID)
+	}
 	var failedResponse base.MessageWithPath
-	pathToUse := req.Path().Copy()
-	if req.IsThisASTheDst() {
-		// TODO(juagargi) find the path to the src endhost
-		// pathToUse =
-		basicResponse, err := e2e.NewResponse(time.Now(), &req.ID, req.Index, pathToUse,
-			false, uint8(req.IndexOfCurrentHop()))
-		if err != nil {
-			return nil, serrors.WrapStr("cannot construct e2e response", err)
-		}
-		failedResponse = &e2e.ResponseSetupFailure{
-			Response:  *basicResponse,
-			ErrorCode: 1,
-			MaxBWs:    req.AllocationTrail,
-		}
-	} else {
-		if err := pathToUse.Reverse(); err != nil {
-			return nil, serrors.WrapStr("cannot reverse path for response", err)
-		}
-		failedResponse = &e2e.SetupReqFailure{
-			SetupReq:  *req,
-			ErrorCode: 1, // TODO(juagargi) use error codes
-		}
+	failedResponse = &e2e.ResponseSetupFailure{
+		Response:  *response,
+		ErrorCode: 1,
+		MaxBWs:    req.AllocationTrail,
 	}
 	// sanity check: all successful requests are SetupReqSuccess. Failed ones are SetupReqFailure.
 	if request.IsSuccess() {
@@ -401,8 +387,12 @@ func (s *Store) AdmitE2EReservation(ctx context.Context, request e2e.SetupReques
 			asAResponse := failedResponse.(*e2e.ResponseSetupFailure)
 			asAResponse.MaxBWs = append(asAResponse.MaxBWs, maxWillingToAlloc)
 		} else {
-			asARequest := failedResponse.(*e2e.SetupReqFailure)
+			asARequest := &e2e.SetupReqFailure{
+				SetupReq:  *req,
+				ErrorCode: 1,
+			}
 			asARequest.AllocationTrail = append(asARequest.AllocationTrail, maxWillingToAlloc)
+			failedResponse = asARequest
 		}
 		return failedResponse, serrors.WrapStr("e2e not admitted", err, "id", req.ID,
 			"index", req.Index)