lnd/lnwire/channel_ready.go
2023-06-13 11:58:33 +02:00

116 lines
3.5 KiB
Go

package lnwire
import (
"bytes"
"io"
"github.com/btcsuite/btcd/btcec/v2"
"github.com/lightningnetwork/lnd/tlv"
)
// ChannelReady is the message that both parties to a new channel creation
// send once they have observed the funding transaction being confirmed on the
// blockchain. ChannelReady contains the signatures necessary for the channel
// participants to advertise the existence of the channel to the rest of the
// network.
type ChannelReady struct {
// ChanID is the outpoint of the channel's funding transaction. This
// can be used to query for the channel in the database.
ChanID ChannelID
// NextPerCommitmentPoint is the secret that can be used to revoke the
// next commitment transaction for the channel.
NextPerCommitmentPoint *btcec.PublicKey
// AliasScid is an alias ShortChannelID used to refer to the underlying
// channel. It can be used instead of the confirmed on-chain
// ShortChannelID for forwarding.
AliasScid *ShortChannelID
// 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.
ExtraData ExtraOpaqueData
}
// NewChannelReady creates a new ChannelReady message, populating it with the
// necessary IDs and revocation secret.
func NewChannelReady(cid ChannelID, npcp *btcec.PublicKey) *ChannelReady {
return &ChannelReady{
ChanID: cid,
NextPerCommitmentPoint: npcp,
ExtraData: make([]byte, 0),
}
}
// A compile time check to ensure ChannelReady implements the lnwire.Message
// interface.
var _ Message = (*ChannelReady)(nil)
// Decode deserializes the serialized ChannelReady message stored in the
// passed io.Reader into the target ChannelReady using the deserialization
// rules defined by the passed protocol version.
//
// This is part of the lnwire.Message interface.
func (c *ChannelReady) Decode(r io.Reader, _ uint32) error {
// Read all the mandatory fields in the message.
err := ReadElements(r,
&c.ChanID,
&c.NextPerCommitmentPoint,
&c.ExtraData,
)
if err != nil {
return err
}
// Next we'll parse out the set of known records. For now, this is just
// the AliasScidRecordType.
var aliasScid ShortChannelID
typeMap, err := c.ExtraData.ExtractRecords(&aliasScid)
if err != nil {
return err
}
// We'll only set AliasScid if the corresponding TLV type was included
// in the stream.
if val, ok := typeMap[AliasScidRecordType]; ok && val == nil {
c.AliasScid = &aliasScid
}
return nil
}
// Encode serializes the target ChannelReady message into the passed io.Writer
// implementation. Serialization will observe the rules defined by the passed
// protocol version.
//
// This is part of the lnwire.Message interface.
func (c *ChannelReady) Encode(w *bytes.Buffer, _ uint32) error {
if err := WriteChannelID(w, c.ChanID); err != nil {
return err
}
if err := WritePublicKey(w, c.NextPerCommitmentPoint); err != nil {
return err
}
// We'll only encode the AliasScid in a TLV segment if it exists.
if c.AliasScid != nil {
recordProducers := []tlv.RecordProducer{c.AliasScid}
err := EncodeMessageExtraData(&c.ExtraData, recordProducers...)
if err != nil {
return err
}
}
return WriteBytes(w, c.ExtraData)
}
// MsgType returns the uint32 code which uniquely identifies this message as a
// ChannelReady message on the wire.
//
// This is part of the lnwire.Message interface.
func (c *ChannelReady) MsgType() MessageType {
return MsgChannelReady
}