lnd.xprv/lnwire/closing_signed.go

89 lines
2.7 KiB
Go

package lnwire
import (
"io"
"github.com/btcsuite/btcutil"
)
// ClosingSigned is sent by both parties to a channel once the channel is clear
// of HTLCs, and is primarily concerned with negotiating fees for the close
// transaction. Each party provides a signature for a transaction with a fee
// that they believe is fair. The process terminates when both sides agree on
// the same fee, or when one side force closes the channel.
//
// NOTE: The responder is able to send a signature without any additional
// messages as all transactions are assembled observing BIP 69 which defines a
// canonical ordering for input/outputs. Therefore, both sides are able to
// arrive at an identical closure transaction as they know the order of the
// inputs/outputs.
type ClosingSigned struct {
// ChannelID serves to identify which channel is to be closed.
ChannelID ChannelID
// FeeSatoshis is the total fee in satoshis that the party to the
// channel would like to propose for the close transaction.
FeeSatoshis btcutil.Amount
// Signature is for the proposed channel close transaction.
Signature Sig
}
// NewClosingSigned creates a new empty ClosingSigned message.
func NewClosingSigned(cid ChannelID, fs btcutil.Amount,
sig Sig) *ClosingSigned {
return &ClosingSigned{
ChannelID: cid,
FeeSatoshis: fs,
Signature: sig,
}
}
// A compile time check to ensure ClosingSigned implements the lnwire.Message
// interface.
var _ Message = (*ClosingSigned)(nil)
// Decode deserializes a serialized ClosingSigned message stored in the passed
// io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *ClosingSigned) Decode(r io.Reader, pver uint32) error {
return readElements(r, &c.ChannelID, &c.FeeSatoshis, &c.Signature)
}
// Encode serializes the target ClosingSigned into the passed io.Writer
// observing the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *ClosingSigned) Encode(w io.Writer, pver uint32) error {
return writeElements(w, c.ChannelID, c.FeeSatoshis, c.Signature)
}
// MsgType returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (c *ClosingSigned) MsgType() MessageType {
return MsgClosingSigned
}
// MaxPayloadLength returns the maximum allowed payload size for a
// ClosingSigned complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *ClosingSigned) MaxPayloadLength(uint32) uint32 {
var length uint32
// ChannelID - 32 bytes
length += 32
// FeeSatoshis - 8 bytes
length += 8
// Signature - 64 bytes
length += 64
return length
}