lnwire: add LeaseExpiry custom record for Open+AcceptChannel

lnwire/accept_channel.go

@@ -99,6 +99,12 @@ type AcceptChannel struct {
 	// open.
 	ChannelType *ChannelType
 
+	// LeaseExpiry represents the absolute expiration height of a channel
+	// lease. This is a custom TLV record that will only apply when a leased
+	// channel is being opened using the script enforced lease commitment
+	// type.
+	LeaseExpiry *LeaseExpiry
+
 	// ExtraData is the set of data that was appended to this message to
 	// fill out the full maximum transport message size. These fields can
 	// be used to specify optional data such as custom TLV fields.
@@ -125,6 +131,9 @@ func (a *AcceptChannel) Encode(w *bytes.Buffer, pver uint32) error {
 	if a.ChannelType != nil {
 		recordProducers = append(recordProducers, a.ChannelType)
 	}
+	if a.LeaseExpiry != nil {
+		recordProducers = append(recordProducers, a.LeaseExpiry)
+	}
 	err := EncodeMessageExtraData(&a.ExtraData, recordProducers...)
 	if err != nil {
 		return err
@@ -226,9 +235,12 @@ func (a *AcceptChannel) Decode(r io.Reader, pver uint32) error {
 
 	// Next we'll parse out the set of known records, keeping the raw tlv
 	// bytes untouched to ensure we don't drop any bytes erroneously.
-	var chanType ChannelType
+	var (
+		chanType    ChannelType
+		leaseExpiry LeaseExpiry
+	)
 	typeMap, err := tlvRecords.ExtractRecords(
-		&a.UpfrontShutdownScript, &chanType,
+		&a.UpfrontShutdownScript, &chanType, &leaseExpiry,
 	)
 	if err != nil {
 		return err
@@ -238,6 +250,9 @@ func (a *AcceptChannel) Decode(r io.Reader, pver uint32) error {
 	if val, ok := typeMap[ChannelTypeRecordType]; ok && val == nil {
 		a.ChannelType = &chanType
 	}
+	if val, ok := typeMap[LeaseExpiryRecordType]; ok && val == nil {
+		a.LeaseExpiry = &leaseExpiry
+	}
 
 	a.ExtraData = tlvRecords
 

lnwire/lnwire_test.go

@@ -360,7 +360,7 @@ func TestLightningWireProtocol(t *testing.T) {
 				return
 			}
 
-			// 1/2 chance empty upfront shutdown script.
+			// 1/2 chance empty TLV records.
 			if r.Intn(2) == 0 {
 				req.UpfrontShutdownScript, err = randDeliveryAddress(r)
 				if err != nil {
@@ -370,6 +370,9 @@ func TestLightningWireProtocol(t *testing.T) {
 
 				req.ChannelType = new(ChannelType)
 				*req.ChannelType = ChannelType(*randRawFeatureVector(r))
+
+				req.LeaseExpiry = new(LeaseExpiry)
+				*req.LeaseExpiry = LeaseExpiry(1337)
 			} else {
 				req.UpfrontShutdownScript = []byte{}
 			}
@@ -429,7 +432,7 @@ func TestLightningWireProtocol(t *testing.T) {
 				return
 			}
 
-			// 1/2 chance empty upfront shutdown script.
+			// 1/2 chance empty TLV records.
 			if r.Intn(2) == 0 {
 				req.UpfrontShutdownScript, err = randDeliveryAddress(r)
 				if err != nil {
@@ -439,6 +442,9 @@ func TestLightningWireProtocol(t *testing.T) {
 
 				req.ChannelType = new(ChannelType)
 				*req.ChannelType = ChannelType(*randRawFeatureVector(r))
+
+				req.LeaseExpiry = new(LeaseExpiry)
+				*req.LeaseExpiry = LeaseExpiry(1337)
 			} else {
 				req.UpfrontShutdownScript = []byte{}
 			}

lnwire/open_channel.go

@@ -135,6 +135,12 @@ type OpenChannel struct {
 	// open.
 	ChannelType *ChannelType
 
+	// LeaseExpiry represents the absolute expiration height of a channel
+	// lease. This is a custom TLV record that will only apply when a leased
+	// channel is being opened using the script enforced lease commitment
+	// type.
+	LeaseExpiry *LeaseExpiry
+
 	// ExtraData is the set of data that was appended to this message to
 	// fill out the full maximum transport message size. These fields can
 	// be used to specify optional data such as custom TLV fields.
@@ -160,6 +166,9 @@ func (o *OpenChannel) Encode(w *bytes.Buffer, pver uint32) error {
 	if o.ChannelType != nil {
 		recordProducers = append(recordProducers, o.ChannelType)
 	}
+	if o.LeaseExpiry != nil {
+		recordProducers = append(recordProducers, o.LeaseExpiry)
+	}
 	err := EncodeMessageExtraData(&o.ExtraData, recordProducers...)
 	if err != nil {
 		return err
@@ -282,9 +291,12 @@ func (o *OpenChannel) Decode(r io.Reader, pver uint32) error {
 
 	// Next we'll parse out the set of known records, keeping the raw tlv
 	// bytes untouched to ensure we don't drop any bytes erroneously.
-	var chanType ChannelType
+	var (
+		chanType    ChannelType
+		leaseExpiry LeaseExpiry
+	)
 	typeMap, err := tlvRecords.ExtractRecords(
-		&o.UpfrontShutdownScript, &chanType,
+		&o.UpfrontShutdownScript, &chanType, &leaseExpiry,
 	)
 	if err != nil {
 		return err
@@ -294,6 +306,9 @@ func (o *OpenChannel) Decode(r io.Reader, pver uint32) error {
 	if val, ok := typeMap[ChannelTypeRecordType]; ok && val == nil {
 		o.ChannelType = &chanType
 	}
+	if val, ok := typeMap[LeaseExpiryRecordType]; ok && val == nil {
+		o.LeaseExpiry = &leaseExpiry
+	}
 
 	o.ExtraData = tlvRecords
 

lnwire/typed_lease_expiry.go

@@ -0,0 +1,52 @@
+package lnwire
+
+import (
+	"io"
+
+	"github.com/lightningnetwork/lnd/tlv"
+)
+
+const (
+	// LeaseExpiryType is the type of the experimental record used to
+	// communicate the expiration of a channel lease throughout the channel
+	// funding process.
+	//
+	// TODO: Decide on actual TLV type. Custom records start at 2^16.
+	LeaseExpiryRecordType tlv.Type = 1 << 16
+)
+
+// LeaseExpiry represents the absolute expiration height of a channel lease. All
+// outputs that pay directly to the channel initiator are locked until this
+// height is reached.
+type LeaseExpiry uint32
+
+// Record returns a TLV record that can be used to encode/decode the LeaseExpiry
+// type from a given TLV stream.
+func (l *LeaseExpiry) Record() tlv.Record {
+	return tlv.MakeStaticRecord(
+		LeaseExpiryRecordType, l, 4, leaseExpiryEncoder, leaseExpiryDecoder,
+	)
+}
+
+// leaseExpiryEncoder is a custom TLV encoder for the LeaseExpiry record.
+func leaseExpiryEncoder(w io.Writer, val interface{}, buf *[8]byte) error {
+	if v, ok := val.(*LeaseExpiry); ok {
+		return tlv.EUint32T(w, uint32(*v), buf)
+	}
+
+	return tlv.NewTypeForEncodingErr(val, "lnwire.LeaseExpiry")
+}
+
+// leaseExpiryDecoder is a custom TLV decoder for the LeaseExpiry record.
+func leaseExpiryDecoder(r io.Reader, val interface{}, buf *[8]byte, l uint64) error {
+	if v, ok := val.(*LeaseExpiry); ok {
+		var leaseExpiry uint32
+		if err := tlv.DUint32(r, &leaseExpiry, buf, l); err != nil {
+			return err
+		}
+		*v = LeaseExpiry(leaseExpiry)
+		return nil
+	}
+
+	return tlv.NewTypeForEncodingErr(val, "lnwire.LeaseExpiry")
+}

lnwire/typed_lease_expiry_test.go

@@ -0,0 +1,25 @@
+package lnwire
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestChannelTypeEncodeDecode tests that we're able to properly encode and
+// decode channel types within TLV streams.
+func TestLeaseExpiryEncodeDecode(t *testing.T) {
+	t.Parallel()
+
+	leaseExpiry := LeaseExpiry(1337)
+
+	var extraData ExtraOpaqueData
+	require.NoError(t, extraData.PackRecords(&leaseExpiry))
+
+	var leaseExpiry2 LeaseExpiry
+	tlvs, err := extraData.ExtractRecords(&leaseExpiry2)
+	require.NoError(t, err)
+
+	require.Contains(t, tlvs, LeaseExpiryRecordType)
+	require.Equal(t, leaseExpiry, leaseExpiry2)
+}