lnd.xprv/lnwire/close_request.go
Olaoluwa Osuntokun 6c7880ef76
lnwire: channels are now identified by outpoint
This commit modifies most of the wire messages to uniquely identify any
*active* channels by their funding output. This allows the wire
protocol to support funding transactions which open several channels in
parallel.

Any pending channels created by partial completion of the funding
workflow are to be identified by a uint64 initialized by both sides as
follows: the initiator of the connection starts from 0, while the
listening node starts from (1 << 63). These pending channel identifiers
are expected to be monotonically increasing with each new funding
workflow between two nodes. This identifier is volatile w.r.t to each
connection initiation.
2016-06-21 13:13:07 -07:00

136 lines
3.9 KiB
Go

package lnwire
import (
"fmt"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/wire"
"github.com/roasbeef/btcutil"
"io"
)
// CloseRequest is sent by either side in order to initiate the cooperative
// closure of a channel. This message is rather sparse as both side implicitly
// know to craft a transaction sending the settled funds of both parties to the
// final delivery addresses negotiated during the funding workflow.
//
// NOTE: The requester is able to only send a signature to initiate the
// cooperative channel closure as all transactions are assembled observing
// BIP 69 which defines a cannonical 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 CloseRequest struct {
// ChannelPoint serves to identify which channel is to be closed.
ChannelPoint *wire.OutPoint
// RequesterCloseSig is the signature of the requester for the fully
// assembled closing transaction.
RequesterCloseSig *btcec.Signature
// Fee is the required fee-per-KB the closing transaction must have.
// It is recommended that a "sufficient" fee be paid in order to achieve
// timely channel closure.
// TODO(roasbeef): if initiator always pays fees, then no longer needed.
Fee btcutil.Amount
}
// NewCloseRequest creates a new CloseRequest.
func NewCloseRequest(cp *wire.OutPoint, sig *btcec.Signature) *CloseRequest {
// TODO(roasbeef): update once fees aren't hardcoded
return &CloseRequest{
ChannelPoint: cp,
RequesterCloseSig: sig,
}
}
// A compile time check to ensure CloseRequest implements the lnwire.Message
// interface.
var _ Message = (*CloseRequest)(nil)
// Decode deserializes a serialized CloseRequest stored in the passed io.Reader
// observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CloseRequest) Decode(r io.Reader, pver uint32) error {
// ChannelPoint (8)
// RequesterCloseSig (73)
// First byte length then sig
// Fee (8)
err := readElements(r,
&c.ChannelPoint,
&c.RequesterCloseSig,
&c.Fee)
if err != nil {
return err
}
return nil
}
// Encode serializes the target CloseRequest into the passed io.Writer observing
// the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *CloseRequest) Encode(w io.Writer, pver uint32) error {
// ChannelID
// RequesterCloseSig
// Fee
err := writeElements(w,
c.ChannelPoint,
c.RequesterCloseSig,
c.Fee)
if err != nil {
return err
}
return nil
}
// Command returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (c *CloseRequest) Command() uint32 {
return CmdCloseRequest
}
// MaxPayloadLength returns the maximum allowed payload size for this message
// observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CloseRequest) MaxPayloadLength(pver uint32) uint32 {
// 36 + 73 + 8
return 117
}
// Validate performs any necessary sanity checks to ensure all fields present
// on the CloseRequest are valid.
//
// This is part of the lnwire.Message interface.
func (c *CloseRequest) Validate() error {
// Fee must be greater than 0.
if c.Fee < 0 {
return fmt.Errorf("Fee must be greater than zero.")
}
// We're good!
return nil
}
// String returns the string representation of the target CloseRequest.
//
// This is part of the lnwire.Message interface.
func (c *CloseRequest) String() string {
var serializedSig []byte
if c.RequesterCloseSig != nil && c.RequesterCloseSig.R != nil {
serializedSig = c.RequesterCloseSig.Serialize()
}
return fmt.Sprintf("\n--- Begin CloseRequest ---\n") +
fmt.Sprintf("ChannelPoint:\t\t%d\n", c.ChannelPoint) +
fmt.Sprintf("CloseSig\t\t%x\n", serializedSig) +
fmt.Sprintf("Fee:\t\t\t%d\n", c.Fee) +
fmt.Sprintf("--- End CloseRequest ---\n")
}