lnwire: introduce message types for dynamic commitment negotiation

lnwire: add tests for dynamic commitment wire serialization

lnwire/dyn_reject.go

@@ -0,0 +1,76 @@
+package lnwire
+
+import (
+	"bytes"
+	"io"
+)
+
+// DynReject is a message that is sent during a dynamic commitments negotiation
+// process. It is sent by both parties to propose new channel parameters.
+type DynReject struct {
+	// ChanID identifies the channel whose parameters we are trying to
+	// re-negotiate.
+	ChanID ChannelID
+
+	// UpdateRejections is a bit vector that specifies which of the
+	// DynPropose parameters we wish to call out as being unacceptable.
+	UpdateRejections RawFeatureVector
+
+	// 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.
+	//
+	// NOTE: Since the fields in this structure are part of the TLV stream,
+	// ExtraData will contain all TLV records _except_ the ones that are
+	// present in earlier parts of this structure.
+	ExtraData ExtraOpaqueData
+}
+
+// A compile time check to ensure DynReject implements the lnwire.Message
+// interface.
+var _ Message = (*DynReject)(nil)
+
+// Encode serializes the target DynReject into the passed io.Writer.
+// Serialization will observe the rules defined by the passed protocol version.
+//
+// This is a part of the lnwire.Message interface.
+func (dr *DynReject) Encode(w *bytes.Buffer, _ uint32) error {
+	if err := WriteChannelID(w, dr.ChanID); err != nil {
+		return err
+	}
+
+	if err := WriteRawFeatureVector(w, &dr.UpdateRejections); err != nil {
+		return err
+	}
+
+	return WriteBytes(w, dr.ExtraData)
+}
+
+// Decode deserializes the serialized DynReject stored in the passed io.Reader
+// into the target DynReject using the deserialization rules defined by the
+// passed protocol version.
+//
+// This is a part of the lnwire.Message interface.
+func (dr *DynReject) Decode(r io.Reader, _ uint32) error {
+	var extra ExtraOpaqueData
+
+	if err := ReadElements(
+		r, &dr.ChanID, &dr.UpdateRejections, &extra,
+	); err != nil {
+		return err
+	}
+
+	if len(extra) != 0 {
+		dr.ExtraData = extra
+	}
+
+	return nil
+}
+
+// MsgType returns the MessageType code which uniquely identifies this message
+// as a DynReject on the wire.
+//
+// This is part of the lnwire.Message interface.
+func (dr *DynReject) MsgType() MessageType {
+	return MsgDynReject
+}