walletrpc: make use of custom lock ID and lock duration in FundPsbt

Author: bhandras

lnrpc/walletrpc/psbt.go

@@ -6,6 +6,7 @@ package walletrpc
 import (
 	"fmt"
 	"math"
+	"time"
 
 	"github.com/btcsuite/btcd/wire"
 	base "github.com/btcsuite/btcwallet/wallet"
@@ -40,31 +41,41 @@ func verifyInputsUnspent(inputs []*wire.TxIn, utxos []*lnwallet.Utxo) error {
 	return nil
 }
 
-// lockInputs requests a lock lease for all inputs specified in a PSBT packet
-// by using the internal, static lock ID of lnd's wallet.
-func lockInputs(w lnwallet.WalletController,
-	outpoints []wire.OutPoint) ([]*base.ListLeasedOutputResult, error) {
+// lockInputs requests lock leases for all inputs specified in a PSBT packet
+// (the passed outpoints), using either the optional custom lock ID and duration
+// or the wallet's internal static lock ID with the default 10-minute duration.
+func lockInputs(w lnwallet.WalletController, outpoints []wire.OutPoint,
+	customLockID *wtxmgr.LockID, customLockDuration time.Duration) (
+	[]*base.ListLeasedOutputResult, error) {
 
 	locks := make(
 		[]*base.ListLeasedOutputResult, len(outpoints),
 	)
 	for idx := range outpoints {
 		lock := &base.ListLeasedOutputResult{
 			LockedOutput: &wtxmgr.LockedOutput{
-				LockID:   chanfunding.LndInternalLockID,
 				Outpoint: outpoints[idx],
 			},
 		}
 
+		lock.LockID = chanfunding.LndInternalLockID
+		if customLockID != nil {
+			lock.LockID = *customLockID
+		}
+
+		lockDuration := chanfunding.DefaultLockDuration
+		if customLockDuration != 0 {
+			lockDuration = customLockDuration
+		}
+
 		// Get the details about this outpoint.
 		utxo, err := w.FetchOutpointInfo(&lock.Outpoint)
 		if err != nil {
 			return nil, fmt.Errorf("fetch outpoint info: %w", err)
 		}
 
 		expiration, err := w.LeaseOutput(
-			lock.LockID, lock.Outpoint,
-			chanfunding.DefaultLockDuration,
+			lock.LockID, lock.Outpoint, lockDuration,
 		)
 		if err != nil {
 			// If we run into a problem with locking one output, we

lnrpc/walletrpc/walletkit_server.go

@@ -1600,6 +1600,24 @@ func (w *WalletKit) FundPsbt(_ context.Context,
 		account = req.Account
 	}
 
+	var customLockID *wtxmgr.LockID
+	if len(req.CustomLockId) > 0 {
+		lockID := wtxmgr.LockID{}
+		if len(req.CustomLockId) != len(lockID) {
+			return nil, fmt.Errorf("custom lock ID must be " +
+				"exactly 32 bytes")
+		}
+
+		copy(lockID[:], req.CustomLockId)
+		customLockID = &lockID
+	}
+
+	var customLockDuration time.Duration
+	if req.LockExpirationSeconds != 0 {
+		customLockDuration = time.Duration(req.LockExpirationSeconds) *
+			time.Second
+	}
+
 	// There are three ways a user can specify what we call the template (a
 	// list of inputs and outputs to use in the PSBT): Either as a PSBT
 	// packet directly with no coin selection, a PSBT with coin selection or
@@ -1619,6 +1637,7 @@ func (w *WalletKit) FundPsbt(_ context.Context,
 		return w.fundPsbtInternalWallet(
 			account, keyScopeFromChangeAddressType(req.ChangeType),
 			packet, minConfs, feeSatPerKW, coinSelectionStrategy,
+			customLockID, customLockDuration,
 		)
 
 	// The template is specified as a PSBT with the intention to perform
@@ -1701,6 +1720,7 @@ func (w *WalletKit) FundPsbt(_ context.Context,
 		return w.fundPsbtCoinSelect(
 			account, changeIndex, packet, minConfs, changeType,
 			feeSatPerKW, coinSelectionStrategy, maxFeeRatio,
+			customLockID, customLockDuration,
 		)
 
 	// The template is specified as a RPC message. We need to create a new
@@ -1758,6 +1778,7 @@ func (w *WalletKit) FundPsbt(_ context.Context,
 		return w.fundPsbtInternalWallet(
 			account, keyScopeFromChangeAddressType(req.ChangeType),
 			packet, minConfs, feeSatPerKW, coinSelectionStrategy,
+			customLockID, customLockDuration,
 		)
 
 	default:
@@ -1770,8 +1791,9 @@ func (w *WalletKit) FundPsbt(_ context.Context,
 // wallet that does not allow specifying custom inputs while selecting coins.
 func (w *WalletKit) fundPsbtInternalWallet(account string,
 	keyScope *waddrmgr.KeyScope, packet *psbt.Packet, minConfs int32,
-	feeSatPerKW chainfee.SatPerKWeight,
-	strategy base.CoinSelectionStrategy) (*FundPsbtResponse, error) {
+	feeSatPerKW chainfee.SatPerKWeight, strategy base.CoinSelectionStrategy,
+	customLockID *wtxmgr.LockID, customLockDuration time.Duration) (
+	*FundPsbtResponse, error) {
 
 	// The RPC parsing part is now over. Several of the following operations
 	// require us to hold the global coin selection lock, so we do the rest
@@ -1885,7 +1907,8 @@ func (w *WalletKit) fundPsbtInternalWallet(account string,
 		}
 
 		response, err = w.lockAndCreateFundingResponse(
-			packet, outpoints, changeIndex,
+			packet, outpoints, changeIndex, customLockID,
+			customLockDuration,
 		)
 
 		return err
@@ -1904,7 +1927,8 @@ func (w *WalletKit) fundPsbtCoinSelect(account string, changeIndex int32,
 	packet *psbt.Packet, minConfs int32,
 	changeType chanfunding.ChangeAddressType,
 	feeRate chainfee.SatPerKWeight, strategy base.CoinSelectionStrategy,
-	maxFeeRatio float64) (*FundPsbtResponse, error) {
+	maxFeeRatio float64, customLockID *wtxmgr.LockID,
+	customLockDuration time.Duration) (*FundPsbtResponse, error) {
 
 	// We want to make sure we don't select any inputs that are already
 	// specified in the template. To do that, we require those inputs to
@@ -2019,7 +2043,10 @@ func (w *WalletKit) fundPsbtCoinSelect(account string, changeIndex int32,
 		}
 
 		// We're done. Let's serialize and return the updated package.
-		return w.lockAndCreateFundingResponse(packet, nil, changeIndex)
+		return w.lockAndCreateFundingResponse(
+			packet, nil, changeIndex, customLockID,
+			customLockDuration,
+		)
 	}
 
 	// The RPC parsing part is now over. Several of the following operations
@@ -2091,7 +2118,8 @@ func (w *WalletKit) fundPsbtCoinSelect(account string, changeIndex int32,
 		}
 
 		response, err = w.lockAndCreateFundingResponse(
-			packet, addedOutpoints, changeIndex,
+			packet, addedOutpoints, changeIndex, customLockID,
+			customLockDuration,
 		)
 
 		return err
@@ -2136,8 +2164,9 @@ func (w *WalletKit) assertNotAvailable(inputs []*wire.TxIn, minConfs int32,
 // lockAndCreateFundingResponse locks the given outpoints and creates a funding
 // response with the serialized PSBT, the change index and the locked UTXOs.
 func (w *WalletKit) lockAndCreateFundingResponse(packet *psbt.Packet,
-	newOutpoints []wire.OutPoint, changeIndex int32) (*FundPsbtResponse,
-	error) {
+	newOutpoints []wire.OutPoint, changeIndex int32,
+	customLockID *wtxmgr.LockID, customLockDuration time.Duration) (
+	*FundPsbtResponse, error) {
 
 	// Make sure we can properly serialize the packet. If this goes wrong
 	// then something isn't right with the inputs, and we probably shouldn't
@@ -2148,7 +2177,9 @@ func (w *WalletKit) lockAndCreateFundingResponse(packet *psbt.Packet,
 		return nil, fmt.Errorf("error serializing funded PSBT: %w", err)
 	}
 
-	locks, err := lockInputs(w.cfg.Wallet, newOutpoints)
+	locks, err := lockInputs(
+		w.cfg.Wallet, newOutpoints, customLockID, customLockDuration,
+	)
 	if err != nil {
 		return nil, fmt.Errorf("could not lock inputs: %w", err)
 	}

lnrpc/walletrpc/walletkit_server_test.go

@@ -660,7 +660,7 @@ func TestFundPsbtCoinSelect(t *testing.T) {
 				"", tc.changeIndex, copiedPacket, 0,
 				tc.changeType, tc.feeRate,
 				rpcServer.cfg.CoinSelectionStrategy,
-				tc.maxFeeRatio,
+				tc.maxFeeRatio, nil, 0,
 			)
 
 			switch {