htlcswitch: rename FailureDetail to OutgoingFailure

Rename FailureDetail in a separate commit so that a FailureDetail
interface can be introduced in the following commit.
OutgoingFailureOnionDecode is renamed to OutgoingFailureDecodeError
to specifically indicate that we could not decode the wire
failure that our payment experienced.

htlcswitch/failure.go

@@ -34,8 +34,8 @@ type LinkError struct {
 	// node.
 	msg lnwire.FailureMessage
 
-	// FailureDetail enriches the wire error with additional information.
-	FailureDetail
+	// OutgoingFailure enriches the wire error with additional information.
+	OutgoingFailure
 }
 
 // NewLinkError returns a LinkError with the failure message provided.
@@ -48,11 +48,11 @@ func NewLinkError(msg lnwire.FailureMessage) *LinkError {
 // NewDetailedLinkError returns a link error that enriches a wire message with
 // a failure detail.
 func NewDetailedLinkError(msg lnwire.FailureMessage,
-	detail FailureDetail) *LinkError {
+	detail OutgoingFailure) *LinkError {
 
 	return &LinkError{
-		msg:           msg,
-		FailureDetail: detail,
+		msg:             msg,
+		OutgoingFailure: detail,
 	}
 }
 
@@ -72,11 +72,11 @@ func (l *LinkError) WireMessage() lnwire.FailureMessage {
 func (l *LinkError) Error() string {
 	// If the link error has no failure detail, return the wire message's
 	// error.
-	if l.FailureDetail == FailureDetailNone {
+	if l.OutgoingFailure == OutgoingFailureNone {
 		return l.msg.Error()
 	}
 
-	return fmt.Sprintf("%v: %v", l.msg.Error(), l.FailureDetail)
+	return fmt.Sprintf("%v: %v", l.msg.Error(), l.OutgoingFailure)
 }
 
 // ForwardingError wraps an lnwire.FailureMessage in a struct that also

htlcswitch/failure_detail.go

@@ -1,63 +1,63 @@
 package htlcswitch
 
-// FailureDetail is an enum which is used to enrich failures with
-// additional information.
-type FailureDetail int
+// OutgoingFailure is an enum which is used to enrich failures which occur in
+// the switch or on our outgoing link with additional metadata.
+type OutgoingFailure int
 
 const (
-	// FailureDetailNone is returned when the wire message contains
+	// OutgoingFailureNone is returned when the wire message contains
 	// sufficient information.
-	FailureDetailNone = iota
+	OutgoingFailureNone OutgoingFailure = iota
 
-	// FailureDetailOnionDecode indicates that we could not decode an
-	// onion error.
-	FailureDetailOnionDecode
+	// OutgoingFailureDecodeError indicates that we could not decode the
+	// failure reason provided for a failed payment.
+	OutgoingFailureDecodeError
 
-	// FailureDetailLinkNotEligible indicates that a routing attempt was
+	// OutgoingFailureLinkNotEligible indicates that a routing attempt was
 	// made over a link that is not eligible for routing.
-	FailureDetailLinkNotEligible
+	OutgoingFailureLinkNotEligible
 
-	// FailureDetailOnChainTimeout indicates that a payment had to be timed
-	// out on chain before it got past the first hop by us or the remote
-	// party.
-	FailureDetailOnChainTimeout
+	// OutgoingFailureOnChainTimeout indicates that a payment had to be
+	// timed out on chain before it got past the first hop by us or the
+	// remote party.
+	OutgoingFailureOnChainTimeout
 
-	// FailureDetailHTLCExceedsMax is returned when a htlc exceeds our
+	// OutgoingFailureHTLCExceedsMax is returned when a htlc exceeds our
 	// policy's maximum htlc amount.
-	FailureDetailHTLCExceedsMax
+	OutgoingFailureHTLCExceedsMax
 
-	// FailureDetailInsufficientBalance is returned when we cannot route a
+	// OutgoingFailureInsufficientBalance is returned when we cannot route a
 	// htlc due to insufficient outgoing capacity.
-	FailureDetailInsufficientBalance
+	OutgoingFailureInsufficientBalance
 
-	// FailureDetailCircularRoute is returned when an attempt is made
+	// OutgoingFailureCircularRoute is returned when an attempt is made
 	// to forward a htlc through our node which arrives and leaves on the
 	// same channel.
-	FailureDetailCircularRoute
+	OutgoingFailureCircularRoute
 )
 
 // String returns the string representation of a failure detail.
-func (fd FailureDetail) String() string {
+func (fd OutgoingFailure) String() string {
 	switch fd {
-	case FailureDetailNone:
+	case OutgoingFailureNone:
 		return "no failure detail"
 
-	case FailureDetailOnionDecode:
-		return "could not decode onion"
+	case OutgoingFailureDecodeError:
+		return "could not decode wire failure"
 
-	case FailureDetailLinkNotEligible:
+	case OutgoingFailureLinkNotEligible:
 		return "link not eligible"
 
-	case FailureDetailOnChainTimeout:
+	case OutgoingFailureOnChainTimeout:
 		return "payment was resolved on-chain, then canceled back"
 
-	case FailureDetailHTLCExceedsMax:
+	case OutgoingFailureHTLCExceedsMax:
 		return "htlc exceeds maximum policy amount"
 
-	case FailureDetailInsufficientBalance:
+	case OutgoingFailureInsufficientBalance:
 		return "insufficient bandwidth to route htlc"
 
-	case FailureDetailCircularRoute:
+	case OutgoingFailureCircularRoute:
 		return "same incoming and outgoing channel"
 
 	default:

htlcswitch/link.go

@@ -2284,7 +2284,7 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 				return lnwire.NewTemporaryChannelFailure(upd)
 			},
 		)
-		return NewDetailedLinkError(failure, FailureDetailHTLCExceedsMax)
+		return NewDetailedLinkError(failure, OutgoingFailureHTLCExceedsMax)
 	}
 
 	// We want to avoid offering an HTLC which will expire in the near
@@ -2319,7 +2319,7 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 			},
 		)
 		return NewDetailedLinkError(
-			failure, FailureDetailInsufficientBalance,
+			failure, OutgoingFailureInsufficientBalance,
 		)
 	}
 

htlcswitch/switch.go

@@ -771,7 +771,7 @@ func (s *Switch) handleLocalDispatch(pkt *htlcPacket) error {
 			// will be returned back to the router.
 			return NewDetailedLinkError(
 				lnwire.NewTemporaryChannelFailure(nil),
-				FailureDetailLinkNotEligible,
+				OutgoingFailureLinkNotEligible,
 			)
 		}
 
@@ -919,11 +919,11 @@ func (s *Switch) parseFailedPayment(deobfuscator ErrorDecrypter,
 				// need to apply an update here since it goes
 				// directly to the router.
 				lnwire.NewTemporaryChannelFailure(nil),
-				FailureDetailOnionDecode,
+				OutgoingFailureDecodeError,
 			)
 
 			log.Errorf("%v: (hash=%v, pid=%d): %v",
-				linkError.FailureDetail, paymentHash, paymentID,
+				linkError.OutgoingFailure, paymentHash, paymentID,
 				err)
 
 			return linkError
@@ -939,10 +939,10 @@ func (s *Switch) parseFailedPayment(deobfuscator ErrorDecrypter,
 	case isResolution && htlc.Reason == nil:
 		linkError := NewDetailedLinkError(
 			&lnwire.FailPermanentChannelFailure{},
-			FailureDetailOnChainTimeout,
+			OutgoingFailureOnChainTimeout,
 		)
 
-		log.Info("%v: hash=%v, pid=%d", linkError.FailureDetail,
+		log.Info("%v: hash=%v, pid=%d", linkError.OutgoingFailure,
 			paymentHash, paymentID)
 
 		return linkError
@@ -1041,7 +1041,7 @@ func (s *Switch) handlePacketForward(packet *htlcPacket) error {
 			if !link.EligibleToForward() {
 				failure = NewDetailedLinkError(
 					&lnwire.FailUnknownNextPeer{},
-					FailureDetailLinkNotEligible,
+					OutgoingFailureLinkNotEligible,
 				)
 			} else {
 				// We'll ensure that the HTLC satisfies the
@@ -1217,7 +1217,7 @@ func checkCircularForward(incoming, outgoing lnwire.ShortChannelID,
 	// node, so we do not include a channel update.
 	return NewDetailedLinkError(
 		lnwire.NewTemporaryChannelFailure(nil),
-		FailureDetailCircularRoute,
+		OutgoingFailureCircularRoute,
 	)
 }
 

htlcswitch/switch_test.go

@@ -1348,7 +1348,7 @@ func TestCircularForwards(t *testing.T) {
 			allowCircularPayment: false,
 			expectedErr: NewDetailedLinkError(
 				lnwire.NewTemporaryChannelFailure(nil),
-				FailureDetailCircularRoute,
+				OutgoingFailureCircularRoute,
 			),
 		},
 	}
@@ -1465,7 +1465,7 @@ func TestCheckCircularForward(t *testing.T) {
 			outgoingLink:  lnwire.NewShortChanIDFromInt(123),
 			expectedErr: NewDetailedLinkError(
 				lnwire.NewTemporaryChannelFailure(nil),
-				FailureDetailCircularRoute,
+				OutgoingFailureCircularRoute,
 			),
 		},
 	}
@@ -1527,7 +1527,7 @@ func TestSkipIneligibleLinksMultiHopForward(t *testing.T) {
 			eligible1: true,
 			failure1: NewDetailedLinkError(
 				lnwire.NewTemporaryChannelFailure(nil),
-				FailureDetailInsufficientBalance,
+				OutgoingFailureInsufficientBalance,
 			),
 			eligible2: true,
 			failure2: NewLinkError(