lnwire: add method ParseAndExtractExtraData

Similar to `ParseAndExtractCustomRecords`, we now add this helper method
to make sure the extra data is parsed correctly.

lnwire/dyn_propose.go

@@ -119,9 +119,9 @@ func (dp *DynPropose) Decode(r io.Reader, _ uint32) error {
 	maxHtlcs := dp.MaxAcceptedHTLCs.Zero()
 	chanType := dp.ChannelType.Zero()
 
-	typeMap, err := tlvRecords.ExtractRecords(
-		&dustLimit, &maxValue, &htlcMin, &reserve, &csvDelay, &maxHtlcs,
-		&chanType,
+	knownRecords, extraData, err := ParseAndExtractExtraData(
+		tlvRecords, &dustLimit, &maxValue, &htlcMin, &reserve,
+		&csvDelay, &maxHtlcs, &chanType,
 	)
 	if err != nil {
 		return err
@@ -129,57 +129,43 @@ func (dp *DynPropose) Decode(r io.Reader, _ uint32) error {
 
 	// Check the results of the TLV Stream decoding and appropriately set
 	// message fields.
-	if val, ok := typeMap[dp.DustLimit.TlvType()]; ok && val == nil {
+	if _, ok := knownRecords[dp.DustLimit.TlvType()]; ok {
 		var rec tlv.RecordT[tlv.TlvType0, tlv.BigSizeT[btcutil.Amount]]
 		rec.Val = dustLimit.Val
 		dp.DustLimit = tlv.SomeRecordT(rec)
-		delete(typeMap, dp.DustLimit.TlvType())
 	}
-	if val, ok := typeMap[dp.MaxValueInFlight.TlvType()]; ok && val == nil {
+
+	if _, ok := knownRecords[dp.MaxValueInFlight.TlvType()]; ok {
 		var rec tlv.RecordT[tlv.TlvType2, MilliSatoshi]
 		rec.Val = maxValue.Val
 		dp.MaxValueInFlight = tlv.SomeRecordT(rec)
-
-		delete(typeMap, dp.MaxValueInFlight.TlvType())
 	}
-	if val, ok := typeMap[dp.HtlcMinimum.TlvType()]; ok && val == nil {
+
+	if _, ok := knownRecords[dp.HtlcMinimum.TlvType()]; ok {
 		var rec tlv.RecordT[tlv.TlvType4, MilliSatoshi]
 		rec.Val = htlcMin.Val
 		dp.HtlcMinimum = tlv.SomeRecordT(rec)
-
-		delete(typeMap, dp.HtlcMinimum.TlvType())
 	}
-	if val, ok := typeMap[dp.ChannelReserve.TlvType()]; ok && val == nil {
+
+	if _, ok := knownRecords[dp.ChannelReserve.TlvType()]; ok {
 		var rec tlv.RecordT[tlv.TlvType6, tlv.BigSizeT[btcutil.Amount]]
 		rec.Val = reserve.Val
 		dp.ChannelReserve = tlv.SomeRecordT(rec)
-
-		delete(typeMap, dp.ChannelReserve.TlvType())
 	}
-	if val, ok := typeMap[dp.CsvDelay.TlvType()]; ok && val == nil {
+
+	if _, ok := knownRecords[dp.CsvDelay.TlvType()]; ok {
 		dp.CsvDelay = tlv.SomeRecordT(csvDelay)
-
-		delete(typeMap, dp.CsvDelay.TlvType())
 	}
-	if val, ok := typeMap[dp.MaxAcceptedHTLCs.TlvType()]; ok && val == nil {
+
+	if _, ok := knownRecords[dp.MaxAcceptedHTLCs.TlvType()]; ok {
 		dp.MaxAcceptedHTLCs = tlv.SomeRecordT(maxHtlcs)
-
-		delete(typeMap, dp.MaxAcceptedHTLCs.TlvType())
 	}
-	if val, ok := typeMap[dp.ChannelType.TlvType()]; ok && val == nil {
+
+	if _, ok := knownRecords[dp.ChannelType.TlvType()]; ok {
 		dp.ChannelType = tlv.SomeRecordT(chanType)
-
-		delete(typeMap, dp.ChannelType.TlvType())
 	}
 
-	if len(typeMap) != 0 {
-		extraData, err := NewExtraOpaqueData(typeMap)
-		if err != nil {
-			return err
-		}
-
-		dp.ExtraData = extraData
-	}
+	dp.ExtraData = extraData
 
 	return nil
 }

lnwire/extra_bytes.go

@@ -269,3 +269,41 @@ func MergeAndEncode(knownRecords []tlv.RecordProducer,
 
 	return EncodeRecords(sortedRecords)
 }
+
+// ParseAndExtractExtraData parses the given extra data into the passed-in
+// records, then returns any remaining records as extra data.
+func ParseAndExtractExtraData(allTlvData ExtraOpaqueData,
+	knownRecords ...tlv.RecordProducer) (fn.Set[tlv.Type],
+	ExtraOpaqueData, error) {
+
+	extraDataTlvMap, err := allTlvData.ExtractRecords(knownRecords...)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Remove the known and now extracted records from the leftover extra
+	// data map.
+	parsedKnownRecords := make(fn.Set[tlv.Type], len(knownRecords))
+	for _, producer := range knownRecords {
+		r := producer.Record()
+
+		// Only remove the records if it was parsed (remainder is nil).
+		// We'll just store the type so we can tell the caller which
+		// records were actually parsed fully.
+		val, ok := extraDataTlvMap[r.Type()]
+		if ok && val == nil {
+			parsedKnownRecords.Add(r.Type())
+			delete(extraDataTlvMap, r.Type())
+		}
+	}
+
+	// Encode the remaining records back into the extra data field. These
+	// records are not in the custom records TLV type range and do not
+	// have associated fields in the struct that produced the records.
+	extraData, err := NewExtraOpaqueData(extraDataTlvMap)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return parsedKnownRecords, extraData, nil
+}

lnwire/test_message.go

@@ -881,10 +881,7 @@ func (dp *DynPropose) RandTestMessage(t *rapid.T) Message {
 		}
 	}
 
-	extraData := RandExtraOpaqueData(t, ignoreRecords)
-	if len(extraData) > 0 {
-		msg.ExtraData = extraData
-	}
+	msg.ExtraData = RandExtraOpaqueData(t, ignoreRecords)
 
 	return msg
 }