lnd.xprv/lnwire/single_funding_complete.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

132 lines
4.0 KiB
Go

package lnwire
import (
"bytes"
"fmt"
"io"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/wire"
)
// SingleFundingComplete is the message Alice sends to Bob once she is able to
// fully assemble the funding transaction, and both versions of the commitment
// transaction. The purpose of this message is to present Bob with the items
// required for him to generate a signature for Alice's version of the
// commitment transaction.
type SingleFundingComplete struct {
// ChannelID serves to uniquely identify the future channel created by
// the initiated single funder workflow.
// TODO(roasbeef): change all to PendingChannelID, document schema
ChannelID uint64
// FundingOutPoint is the outpoint (txid:index) of the funding
// transaction. With this value, Bob will be able to generate a
// signature for Alice's version of the commitment transaction.
FundingOutPoint *wire.OutPoint
// CommitSignature is Alice's signature for Bob's version of the
// commitment transaction.
CommitSignature *btcec.Signature
}
// NewSingleFundingComplete creates, and returns a new empty
// SingleFundingResponse.
func NewSingleFundingComplete(chanID uint64, fundingPoint *wire.OutPoint,
commitSig *btcec.Signature) *SingleFundingComplete {
return &SingleFundingComplete{
ChannelID: chanID,
FundingOutPoint: fundingPoint,
CommitSignature: commitSig,
}
}
// Decode deserializes the serialized SingleFundingComplete stored in the passed
// io.Reader into the target SingleFundingComplete using the deserialization
// rules defined by the passed protocol version.
//
// This is part of the lnwire.Message interface.
func (s *SingleFundingComplete) Decode(r io.Reader, pver uint32) error {
// ChannelID (8)
// FundingOutPoint (36)
// Commitment Signature (73)
err := readElements(r,
&s.ChannelID,
&s.FundingOutPoint,
&s.CommitSignature)
if err != nil {
return err
}
return nil
}
// Encode serializes the target SingleFundingComplete 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 (s *SingleFundingComplete) Encode(w io.Writer, pver uint32) error {
// ChannelID (8)
// FundingOutPoint (36)
// Commitment Signature (73)
err := writeElements(w,
s.ChannelID,
s.FundingOutPoint,
s.CommitSignature)
if err != nil {
return err
}
return nil
}
// Command returns the uint32 code which uniquely identifies this message as a
// SingleFundingRequest on the wire.
//
// This is part of the lnwire.Message interface.
func (s *SingleFundingComplete) Command() uint32 {
return CmdSingleFundingComplete
}
// MaxPayloadLength returns the maximum allowed payload length for a
// SingleFundingComplete. This is calculated by summing the max length of all
// the fields within a SingleFundingResponse. To enforce a maximum
// DeliveryPkScript size, the size of a P2PKH public key script is used.
// Therefore, the final breakdown is: 8 + 36 + 73 = 117
//
// This is part of the lnwire.Message interface.
func (s *SingleFundingComplete) MaxPayloadLength(uint32) uint32 {
return 117
}
// Validate examines each populated field within the SingleFundingComplete for
// field sanity.
//
// This is part of the lnwire.Message interface.
func (s *SingleFundingComplete) Validate() error {
var zeroHash [32]byte
if bytes.Equal(zeroHash[:], s.FundingOutPoint.Hash[:]) {
return fmt.Errorf("funding outpoint hash must be non-zero")
}
if s.CommitSignature == nil {
return fmt.Errorf("commitment signature must be non-nil")
}
// We're good!
return nil
}
// String returns the string representation of the SingleFundingResponse.
//
// This is part of the lnwire.Message interface.
func (s *SingleFundingComplete) String() string {
return fmt.Sprintf("\n--- Begin SingleFundingComplete ---\n") +
fmt.Sprintf("ChannelID:\t\t\t%d\n", s.ChannelID) +
fmt.Sprintf("FundingOutPoint:\t\t\t%x\n", s.FundingOutPoint) +
fmt.Sprintf("CommitSignature\t\t\t\t%x\n", s.CommitSignature) +
fmt.Sprintf("--- End SingleFundingComplete ---\n")
}