lnd.xprv/lnwallet/reservation.go

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package wallet
import (
"fmt"
"sync"
"bytes"
"encoding/binary"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
)
// ChannelReservation...
type ChannelReservation struct {
FundingType FundingType
//All of these are *our* values/requirements
//Their requirements can be the same or lower
FundingAmount btcutil.Amount //The amount we want to fund with
ReserveAmount btcutil.Amount //Our reserve. assume symmetric reserve amounts
MinFeePerKb btcutil.Amount
MinTotalFundingAmount btcutil.Amount //Our minimum value for the entire channel
//for CLTV it is nLockTime, for CSV it's nSequence, for segwit it's not needed
FundingLockTime uint32
sync.RWMutex // All fields below owned by the lnwallet.
//Current state of the channel, progesses through until complete
//Makes sure we can't go backwards and only accept messages once
channelState uint8
theirInputs []*wire.TxIn
ourInputs []*wire.TxIn
//NOTE(j): FundRequest assumes there is only one change (see ChangePkScript)
theirChange []*wire.TxOut
ourChange []*wire.TxOut
ourKey *btcec.PrivateKey
theirKey *btcec.PublicKey
// In order of sorted inputs. Sorting is done in accordance
// to BIP-69: https://github.com/bitcoin/bips/blob/master/bip-0069.mediawiki.
theirSigs [][]byte
ourSigs [][]byte
normalizedTxID wire.ShaHash
fundingTx *wire.MsgTx
// TODO(roasbef): time locks, who pays fee etc.
// TODO(roasbeef): record Bob's ln-ID?
completedFundingTx *btcutil.Tx
reservationID uint64
wallet *LightningWallet
//For CSV/CLTV revocation
ourRevocation []byte
theirRevocation []byte
theirRevocationHash []byte
//Final delivery address (P2PKH for now)
ourDeliveryAddress []byte
theirDeliveryAddress []byte
chanOpen chan *LightningChannel
}
//FundRequest serialize
//(reading from ChannelReservation directly to reduce the amount of copies)
//We can move this stuff to another file too if it's too big...
func (r *ChannelReservation) SerializeFundRequest() ([]byte, error) {
var err error
//Buffer to dump in the serialized data
b := new(bytes.Buffer)
//Fund Request
err = b.WriteByte(0x30)
if err != nil {
return nil, err
}
//ChannelType (1)
//Default to current type
err = b.WriteByte(uint8(0))
if err != nil {
return nil, err
}
//RequesterFundingAmount - The amount we are going to fund (8)
//check for positive values
err = binary.Write(b, binary.BigEndian, r.FundingAmount)
if err != nil {
return nil, err
}
//RequesterChannelMinCapacity (8)
//The amount needed to accept and sign the channel commit later
err = binary.Write(b, binary.BigEndian, r.MinTotalFundingAmount)
if err != nil {
return nil, err
}
//RevocationHash (20)
//Our revocation hash being contributed (for CLTV/CSV)
_, err = b.Write(btcutil.Hash160(r.ourRevocation))
if err != nil {
return nil, err
}
//CommitPubkey (33)
//Our public key being used for the commitment
ourPubKey := r.ourKey.PubKey().SerializeCompressed()
if len(ourPubKey) != 33 { //validation, can remove later? (NO UNCOMPRESSED KEYS!)
return nil, fmt.Errorf("Serialize FundReq: our Pubkey length incorrect")
}
_, err = b.Write(ourPubKey)
if err != nil {
return nil, err
}
//DeliveryPkHash (20)
//For now it's a P2PKH, but we will add an extra byte later for the
//option for P2SH
//This is the address to send funds to when complete or refunded
_, err = b.Write(r.ourDeliveryAddress)
if err != nil {
return nil, err
}
//ReserveAmount (8)
//Our own reserve amount
err = binary.Write(b, binary.BigEndian, r.ReserveAmount)
if err != nil {
return nil, err
}
//Minimum transaction fee per kb (8)
err = binary.Write(b, binary.BigEndian, r.MinFeePerKb)
if err != nil {
return nil, err
}
//LockTime (4)
err = binary.Write(b, binary.BigEndian, r.FundingLockTime)
if err != nil {
return nil, err
}
//Fee payer (default to split currently) (1)
err = binary.Write(b, binary.BigEndian, 0)
if err != nil {
return nil, err
}
//ChangePkScript
//Length (1)
changeScriptLength := len(r.ourChange[0].PkScript)
if changeScriptLength > 255 {
return nil, fmt.Errorf("Your changeScriptLength is too long!")
}
err = binary.Write(b, binary.BigEndian, uint8(changeScriptLength))
if err != nil {
return nil, err
}
//For now it's a P2PKH, but we will add an extra byte later for the
//option for P2SH
//This is the address to send change to (only allow one)
//ChangePkScript (length of script)
_, err = b.Write(r.ourChange[0].PkScript)
if err != nil {
return nil, err
}
//Append the unsigned(!!) txins
//First one byte for the amount of txins (1)
if len(r.ourInputs) > 127 {
return nil, fmt.Errorf("Too many txins")
}
err = b.WriteByte(uint8(len(r.ourInputs)))
if err != nil {
return nil, err
}
//Append the actual Txins (NumOfTxins * 36)
//Do not include the sequence number to eliminate funny business
for _, in := range r.ourInputs {
//Hash
_, err = b.Write(in.PreviousOutPoint.Hash.Bytes())
if err != nil {
return nil, err
}
//Index
err = binary.Write(b, binary.BigEndian, in.PreviousOutPoint.Index)
if err != nil {
return nil, err
}
}
return b.Bytes(), err
}
func (r *ChannelReservation) DeserializeFundRequest(wireMsg []byte) error {
//Make sure we're not overwriting stuff...
//Update the channelState to 1 before progressing if you want to re-do it.
//Assumes only one thread is writing at a time
if r.channelState > 1 {
return fmt.Errorf("FundRequest: Channel State Mismatch")
}
var err error
b := bytes.NewBuffer(wireMsg)
msgid, _ := b.ReadByte()
if msgid != 0x30 {
return fmt.Errorf("Cannot deserialize: not a funding request")
}
if err != nil {
return err
}
//Update the channel state as complete
r.channelState = 2
return nil
}
//Validation on the data being supplied from the fund request
func (r *ChannelReservation) ValidateFundRequest(wireMsg []byte) error {
return nil
}
//Serialize CSV Revocation
//After the Commitment Transaction has been created, send a message to revoke this tx
func (r *ChannelReservation) SerializeCSVRefundRevocation() ([]byte, error) {
return nil, nil
}
//Deserialize CSV Revocation
//Validate the revocation, after this step, the channel is fully set up
func (r *ChannelReservation) DeserializeCSVRefundRevocation() error {
return nil
}
// newChannelReservation...
func newChannelReservation(t FundingType, fundingAmt btcutil.Amount,
minFeeRate btcutil.Amount, wallet *LightningWallet, id uint64) *ChannelReservation {
return &ChannelReservation{
FundingType: t,
FundingAmount: fundingAmt,
MinFeePerKb: minFeeRate,
wallet: wallet,
reservationID: id,
}
}
// OurFunds...
func (r *ChannelReservation) OurFunds() ([]*wire.TxIn, []*wire.TxOut, *btcec.PublicKey) {
r.RLock()
defer r.RUnlock()
return r.ourInputs, r.ourChange, r.ourKey.PubKey()
}
// AddCounterPartyFunds...
func (r *ChannelReservation) AddFunds(theirInputs []*wire.TxIn, theirChangeOutputs []*wire.TxOut, multiSigKey *btcec.PublicKey) error {
errChan := make(chan error, 1)
r.wallet.msgChan <- &addCounterPartyFundsMsg{
pendingFundingID: r.reservationID,
theirInputs: theirInputs,
theirChangeOutputs: theirChangeOutputs,
theirKey: multiSigKey,
err: errChan,
}
return <-errChan
}
// OurSigs...
func (r *ChannelReservation) OurSigs() [][]byte {
r.RLock()
defer r.RUnlock()
return r.ourSigs
}
// TheirFunds...
// TODO(roasbeef): return error if accessors not yet populated?
func (r *ChannelReservation) TheirFunds() ([]*wire.TxIn, []*wire.TxOut, *btcec.PublicKey) {
r.RLock()
defer r.RUnlock()
return r.theirInputs, r.theirChange, r.theirKey
}
// CompleteFundingReservation...
func (r *ChannelReservation) CompleteReservation(theirSigs [][]byte) error {
errChan := make(chan error, 1)
r.wallet.msgChan <- &addCounterPartySigsMsg{
pendingFundingID: r.reservationID,
theirSigs: theirSigs,
err: errChan,
}
return <-errChan
}
// FinalFundingTransaction...
func (r *ChannelReservation) FinalFundingTx() *btcutil.Tx {
r.RLock()
defer r.RUnlock()
return r.completedFundingTx
}
// RequestFundingReserveCancellation...
// TODO(roasbeef): also return mutated state?
func (r *ChannelReservation) Cancel() error {
errChan := make(chan error, 1)
r.wallet.msgChan <- &fundingReserveCancelMsg{
pendingFundingID: r.reservationID,
err: errChan,
}
return <-errChan
}
// WaitForChannelOpen...
func (r *ChannelReservation) WaitForChannelOpen() *LightningChannel {
return nil
}
2015-12-16 00:22:33 +03:00
// * finish reset of tests
// * comment out stuff that'll need a node.
// * start on commitment side
// * implement rusty's shachain
// * set up logic to get notification from node when funding tx gets 6 deep.
// * prob spawn into ChainNotifier struct
// * create builder for initial funding transaction
// * fascade through the wallet, for signing and such.
// * channel should have active namespace to it's bucket, query at that point fo past commits etc