lnd.xprv/lnwire/funding_request.go

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package lnwire
import (
"fmt"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/wire"
"github.com/roasbeef/btcutil"
"io"
)
type FundingRequest struct {
ReservationID uint64
ChannelType uint8
RequesterFundingAmount btcutil.Amount
RequesterReserveAmount btcutil.Amount
MinFeePerKb btcutil.Amount
// The funding requester can request payment
// This wallet only allows positive values,
// which is a payment to the responder
// (This can be used to fund the Reserve)
// If the responder disagrees, then the funding request fails
// THIS VALUE GOES INTO THE RESPONDER'S FUNDING AMOUNT
// total requester input value = RequesterFundingAmount + PaymentAmount + "Total Change" + Fees(?)
// RequesterFundingAmount = "Available Balance" + RequesterReserveAmount
// Payment SHOULD NOT be acknowledged until the minimum confirmation has elapsed
// (Due to double-spend risks the recipient will not want to acknolwedge confirmation until later)
// This is to make a payment as part of opening the channel
PaymentAmount btcutil.Amount
// Minimum number of confirmations to validate transaction
MinDepth uint32
// Should double-check the total funding later
MinTotalFundingAmount btcutil.Amount
// CLTV/CSV lock-time to use
LockTime uint32
// Who pays the fees
// 0: (default) channel initiator
// 1: split
// 2: channel responder
FeePayer uint8
RevocationHash [20]byte
Pubkey *btcec.PublicKey
DeliveryPkScript PkScript // *MUST* be either P2PKH or P2SH
ChangePkScript PkScript // *MUST* be either P2PKH or P2SH
Inputs []*wire.TxIn
}
func (c *FundingRequest) Decode(r io.Reader, pver uint32) error {
// Reservation ID (8)
// Channel Type (1)
// Funding Amount (8)
// Channel Minimum Capacity (8)
// Revocation Hash (20)
// Commitment Pubkey (32)
// Reserve Amount (8)
// Minimum Transaction Fee Per Kb (8)
// PaymentAmount (8)
// MinDepth (4)
// LockTime (4)
// FeePayer (1)
// DeliveryPkScript (final delivery)
// First byte length then pkscript
// ChangePkScript (change for extra from inputs)
// First byte length then pkscript
// Inputs: Create the TxIns
// First byte is number of inputs
// For each input, it's 32bytes txin & 4bytes index
err := readElements(r,
&c.ReservationID,
&c.ChannelType,
&c.RequesterFundingAmount,
&c.MinTotalFundingAmount,
&c.RevocationHash,
&c.Pubkey,
&c.RequesterReserveAmount,
&c.MinFeePerKb,
&c.PaymentAmount,
&c.MinDepth,
&c.LockTime,
&c.FeePayer,
&c.DeliveryPkScript,
&c.ChangePkScript,
&c.Inputs)
if err != nil {
return err
}
return nil
}
// Creates a new FundingRequest
func NewFundingRequest() *FundingRequest {
return &FundingRequest{}
}
// Serializes the item from the FundingRequest struct
// Writes the data to w
func (c *FundingRequest) Encode(w io.Writer, pver uint32) error {
// Channel Type
// Funding Amont
// Channel Minimum Capacity
// Revocation Hash
// Commitment Pubkey
// Reserve Amount
// Minimum Transaction Fee Per KB
// LockTime
// FeePayer
// DeliveryPkScript
// ChangePkScript
// Inputs: Append the actual Txins
err := writeElements(w,
c.ReservationID,
c.ChannelType,
c.RequesterFundingAmount,
c.MinTotalFundingAmount,
c.RevocationHash,
c.Pubkey,
c.RequesterReserveAmount,
c.MinFeePerKb,
c.PaymentAmount,
c.MinDepth,
c.LockTime,
c.FeePayer,
c.DeliveryPkScript,
c.ChangePkScript,
c.Inputs)
if err != nil {
return err
}
return nil
}
func (c *FundingRequest) Command() uint32 {
return CmdFundingRequest
}
func (c *FundingRequest) MaxPayloadLength(uint32) uint32 {
// 110 (base size) + 26 (pkscript) + 26 (pkscript) + 1 (numTxes) + 127*36(127 inputs * sha256+idx)
return 4735
}
// Makes sure the struct data is valid (e.g. no negatives or invalid pkscripts)
func (c *FundingRequest) Validate() error {
var err error
// No negative values
if c.RequesterFundingAmount < 0 {
return fmt.Errorf("RequesterFundingAmount cannot be negative")
}
if c.RequesterReserveAmount < 0 {
return fmt.Errorf("RequesterReserveAmount cannot be negative")
}
if c.MinFeePerKb < 0 {
return fmt.Errorf("MinFeePerKb cannot be negative")
}
if c.MinTotalFundingAmount < 0 {
return fmt.Errorf("MinTotalFundingAmount cannot be negative")
}
// Validation of what makes sense...
if c.MinTotalFundingAmount < c.RequesterFundingAmount {
return fmt.Errorf("Requester's minimum too low.")
}
if c.RequesterFundingAmount < c.RequesterReserveAmount {
return fmt.Errorf("Reserve must be below Funding Amount")
}
// This wallet only allows payment from the requester to responder
if c.PaymentAmount < 0 {
return fmt.Errorf("This wallet requieres payment to be greater than zero.")
}
// Make sure there's not more than 127 inputs
if len(c.Inputs) > 127 {
return fmt.Errorf("Too many inputs")
}
// DeliveryPkScript is either P2SH or P2PKH
err = ValidatePkScript(c.DeliveryPkScript)
if err != nil {
return err
}
// ChangePkScript is either P2SH or P2PKH
err = ValidatePkScript(c.ChangePkScript)
if err != nil {
return err
}
// We're good!
return nil
}
func (c *FundingRequest) String() string {
var inputs string
for i, in := range c.Inputs {
inputs += fmt.Sprintf("\n Slice\t%d\n", i)
if &in != nil {
inputs += fmt.Sprintf("\tHash\t%s\n", in.PreviousOutPoint.Hash)
inputs += fmt.Sprintf("\tIndex\t%d\n", in.PreviousOutPoint.Index)
}
}
var serializedPubkey []byte
if &c.Pubkey != nil && c.Pubkey.X != nil {
serializedPubkey = c.Pubkey.SerializeCompressed()
}
return fmt.Sprintf("\n--- Begin FundingRequest ---\n") +
fmt.Sprintf("ReservationID:\t\t\t%d\n", c.ReservationID) +
fmt.Sprintf("ChannelType:\t\t\t%x\n", c.ChannelType) +
fmt.Sprintf("RequesterFundingAmount:\t\t%s\n", c.RequesterFundingAmount.String()) +
fmt.Sprintf("RequesterReserveAmount:\t\t%s\n", c.RequesterReserveAmount.String()) +
fmt.Sprintf("MinFeePerKb:\t\t\t%s\n", c.MinFeePerKb.String()) +
fmt.Sprintf("PaymentAmount:\t\t\t%s\n", c.PaymentAmount.String()) +
fmt.Sprintf("MinDepth:\t\t\t%d\n", c.MinDepth) +
fmt.Sprintf("MinTotalFundingAmount\t\t%s\n", c.MinTotalFundingAmount.String()) +
fmt.Sprintf("LockTime\t\t\t%d\n", c.LockTime) +
fmt.Sprintf("FeePayer\t\t\t%x\n", c.FeePayer) +
fmt.Sprintf("RevocationHash\t\t\t%x\n", c.RevocationHash) +
fmt.Sprintf("Pubkey\t\t\t\t%x\n", serializedPubkey) +
fmt.Sprintf("DeliveryPkScript\t\t%x\n", c.DeliveryPkScript) +
fmt.Sprintf("Inputs:") +
inputs +
fmt.Sprintf("--- End FundingRequest ---\n")
}