multi: distinguish between htlc in and out constraints

htlcswitch/link.go

@@ -71,10 +71,8 @@ const (
 // the error possibly carrying along a ChannelUpdate message that includes the
 // latest policy.
 type ForwardingPolicy struct {
-	// MinHTLC is the smallest HTLC that is to be forwarded. This is
-	// set when a channel is first opened, and will be static for the
-	// lifetime of the channel.
-	MinHTLC lnwire.MilliSatoshi
+	// MinHTLC is the smallest HTLC that is to be forwarded.
+	MinHTLCOut lnwire.MilliSatoshi
 
 	// MaxHTLC is the largest HTLC that is to be forwarded.
 	MaxHTLC lnwire.MilliSatoshi
@@ -2218,9 +2216,9 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 	// As our first sanity check, we'll ensure that the passed HTLC isn't
 	// too small for the next hop. If so, then we'll cancel the HTLC
 	// directly.
-	if amt < policy.MinHTLC {
+	if amt < policy.MinHTLCOut {
 		l.log.Errorf("outgoing htlc(%x) is too small: min_htlc=%v, "+
-			"htlc_value=%v", payHash[:], policy.MinHTLC,
+			"htlc_value=%v", payHash[:], policy.MinHTLCOut,
 			amt)
 
 		// As part of the returned error, we'll send our latest routing

htlcswitch/link_test.go

@@ -1694,7 +1694,7 @@ func newSingleLinkTestHarness(chanAmt, chanReserve btcutil.Amount) (
 			quit:     make(chan struct{}),
 		}
 		globalPolicy = ForwardingPolicy{
-			MinHTLC:       lnwire.NewMSatFromSatoshis(5),
+			MinHTLCOut:    lnwire.NewMSatFromSatoshis(5),
 			MaxHTLC:       lnwire.NewMSatFromSatoshis(chanAmt),
 			BaseFee:       lnwire.NewMSatFromSatoshis(1),
 			TimeLockDelta: 6,
@@ -4253,7 +4253,7 @@ func (h *persistentLinkHarness) restartLink(
 		}
 
 		globalPolicy = ForwardingPolicy{
-			MinHTLC:       lnwire.NewMSatFromSatoshis(5),
+			MinHTLCOut:    lnwire.NewMSatFromSatoshis(5),
 			BaseFee:       lnwire.NewMSatFromSatoshis(1),
 			TimeLockDelta: 6,
 		}
@@ -5512,7 +5512,7 @@ func TestCheckHtlcForward(t *testing.T) {
 		cfg: ChannelLinkConfig{
 			FwrdingPolicy: ForwardingPolicy{
 				TimeLockDelta: 20,
-				MinHTLC:       500,
+				MinHTLCOut:    500,
 				MaxHTLC:       1000,
 				BaseFee:       10,
 			},

htlcswitch/test_utils.go

@@ -1078,7 +1078,7 @@ func newHopNetwork() *hopNetwork {
 	defaultDelta := uint32(6)
 
 	globalPolicy := ForwardingPolicy{
-		MinHTLC:       lnwire.NewMSatFromSatoshis(5),
+		MinHTLCOut:    lnwire.NewMSatFromSatoshis(5),
 		BaseFee:       lnwire.NewMSatFromSatoshis(1),
 		TimeLockDelta: defaultDelta,
 	}