Merge pull request #3405 from wpaulino/chainrpc-sane-defaults

chainntnfs: validate conf/spend ntfn registration parameters

chainntnfs/bitcoindnotify/bitcoind.go

@@ -9,6 +9,7 @@ import (
 	"github.com/btcsuite/btcd/btcjson"
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 	"github.com/btcsuite/btcwallet/chain"
@@ -39,8 +40,6 @@ type chainUpdate struct {
 // chain client. Multiple concurrent clients are supported. All notifications
 // are achieved via non-blocking sends on client channels.
 type BitcoindNotifier struct {
-	confClientCounter  uint64 // To be used atomically.
-	spendClientCounter uint64 // To be used atomically.
 	epochClientCounter uint64 // To be used atomically.
 
 	started int32 // To be used atomically.
@@ -616,23 +615,11 @@ func (b *BitcoindNotifier) notifyBlockEpochClient(epochClient *blockEpochRegistr
 func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	pkScript []byte, heightHint uint32) (*chainntnfs.SpendEvent, error) {
 
-	// First, we'll construct a spend notification request and hand it off
+	// Register the conf notification with the TxNotifier. A non-nil value
-	// to the txNotifier.
+	// for `dispatch` will be returned if we are required to perform a
-	spendID := atomic.AddUint64(&b.spendClientCounter, 1)
+	// manual scan for the confirmation. Otherwise the notifier will begin
-	spendRequest, err := chainntnfs.NewSpendRequest(outpoint, pkScript)
+	// watching at tip for the transaction to confirm.
-	if err != nil {
+	ntfn, err := b.txNotifier.RegisterSpend(outpoint, pkScript, heightHint)
-		return nil, err
-	}
-	ntfn := &chainntnfs.SpendNtfn{
-		SpendID:      spendID,
-		SpendRequest: spendRequest,
-		Event: chainntnfs.NewSpendEvent(func() {
-			b.txNotifier.CancelSpend(spendRequest, spendID)
-		}),
-		HeightHint: heightHint,
-	}
-
-	historicalDispatch, _, err := b.txNotifier.RegisterSpend(ntfn)
 	if err != nil {
 		return nil, err
 	}
@@ -641,17 +628,18 @@ func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// outpoint/output script as spent.
 	//
 	// TODO(wilmer): use LoadFilter API instead.
-	if spendRequest.OutPoint == chainntnfs.ZeroOutPoint {
+	if outpoint == nil || *outpoint == chainntnfs.ZeroOutPoint {
-		addr, err := spendRequest.PkScript.Address(b.chainParams)
+		_, addrs, _, err := txscript.ExtractPkScriptAddrs(
+			pkScript, b.chainParams,
+		)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("unable to parse script: %v", err)
 		}
-		addrs := []btcutil.Address{addr}
 		if err := b.chainConn.NotifyReceived(addrs); err != nil {
 			return nil, err
 		}
 	} else {
-		ops := []*wire.OutPoint{&spendRequest.OutPoint}
+		ops := []*wire.OutPoint{outpoint}
 		if err := b.chainConn.NotifySpent(ops); err != nil {
 			return nil, err
 		}
@@ -660,7 +648,7 @@ func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// If the txNotifier didn't return any details to perform a historical
 	// scan of the chain, then we can return early as there's nothing left
 	// for us to do.
-	if historicalDispatch == nil {
+	if ntfn.HistoricalDispatch == nil {
 		return ntfn.Event, nil
 	}
 
@@ -670,9 +658,9 @@ func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// We'll short-circuit the path when dispatching the spend of a script,
 	// rather than an outpoint, as there aren't any additional checks we can
 	// make for scripts.
-	if spendRequest.OutPoint == chainntnfs.ZeroOutPoint {
+	if ntfn.HistoricalDispatch.OutPoint == chainntnfs.ZeroOutPoint {
 		select {
-		case b.notificationRegistry <- historicalDispatch:
+		case b.notificationRegistry <- ntfn.HistoricalDispatch:
 		case <-b.quit:
 			return nil, chainntnfs.ErrChainNotifierShuttingDown
 		}
@@ -687,16 +675,16 @@ func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// We'll start by checking the backend's UTXO set to determine whether
 	// the outpoint has been spent. If it hasn't, we can return to the
 	// caller as well.
-	txOut, err := b.chainConn.GetTxOut(
+	txOut, err := b.chainConn.GetTxOut(&outpoint.Hash, outpoint.Index, true)
-		&spendRequest.OutPoint.Hash, spendRequest.OutPoint.Index, true,
-	)
 	if err != nil {
 		return nil, err
 	}
 	if txOut != nil {
 		// We'll let the txNotifier know the outpoint is still unspent
 		// in order to begin updating its spend hint.
-		err := b.txNotifier.UpdateSpendDetails(spendRequest, nil)
+		err := b.txNotifier.UpdateSpendDetails(
+			ntfn.HistoricalDispatch.SpendRequest, nil,
+		)
 		if err != nil {
 			return nil, err
 		}
@@ -711,14 +699,14 @@ func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// index (if enabled) to determine if we have a better rescan starting
 	// height. We can do this as the GetRawTransaction call will return the
 	// hash of the block it was included in within the chain.
-	tx, err := b.chainConn.GetRawTransactionVerbose(&spendRequest.OutPoint.Hash)
+	tx, err := b.chainConn.GetRawTransactionVerbose(&outpoint.Hash)
 	if err != nil {
 		// Avoid returning an error if the transaction was not found to
 		// proceed with fallback methods.
 		jsonErr, ok := err.(*btcjson.RPCError)
 		if !ok || jsonErr.Code != btcjson.ErrRPCNoTxInfo {
 			return nil, fmt.Errorf("unable to query for txid %v: %v",
-				spendRequest.OutPoint.Hash, err)
+				outpoint.Hash, err)
 		}
 	}
 
@@ -741,15 +729,15 @@ func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 			return nil, err
 		}
 
-		if uint32(blockHeight) > historicalDispatch.StartHeight {
+		if uint32(blockHeight) > ntfn.HistoricalDispatch.StartHeight {
-			historicalDispatch.StartHeight = uint32(blockHeight)
+			ntfn.HistoricalDispatch.StartHeight = uint32(blockHeight)
 		}
 	}
 
 	// Now that we've determined the starting point of our rescan, we can
 	// dispatch it and return.
 	select {
-	case b.notificationRegistry <- historicalDispatch:
+	case b.notificationRegistry <- ntfn.HistoricalDispatch:
 	case <-b.quit:
 		return nil, chainntnfs.ErrChainNotifierShuttingDown
 	}
@@ -827,41 +815,23 @@ func (b *BitcoindNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
 	pkScript []byte,
 	numConfs, heightHint uint32) (*chainntnfs.ConfirmationEvent, error) {
 
-	// Construct a notification request for the transaction and send it to
-	// the main event loop.
-	confID := atomic.AddUint64(&b.confClientCounter, 1)
-	confRequest, err := chainntnfs.NewConfRequest(txid, pkScript)
-	if err != nil {
-		return nil, err
-	}
-	ntfn := &chainntnfs.ConfNtfn{
-		ConfID:           confID,
-		ConfRequest:      confRequest,
-		NumConfirmations: numConfs,
-		Event: chainntnfs.NewConfirmationEvent(numConfs, func() {
-			b.txNotifier.CancelConf(confRequest, confID)
-		}),
-		HeightHint: heightHint,
-	}
-
-	chainntnfs.Log.Infof("New confirmation subscription: %v, num_confs=%v",
-		confRequest, numConfs)
-
 	// Register the conf notification with the TxNotifier. A non-nil value
 	// for `dispatch` will be returned if we are required to perform a
 	// manual scan for the confirmation. Otherwise the notifier will begin
 	// watching at tip for the transaction to confirm.
-	dispatch, _, err := b.txNotifier.RegisterConf(ntfn)
+	ntfn, err := b.txNotifier.RegisterConf(
+		txid, pkScript, numConfs, heightHint,
+	)
 	if err != nil {
 		return nil, err
 	}
 
-	if dispatch == nil {
+	if ntfn.HistoricalDispatch == nil {
 		return ntfn.Event, nil
 	}
 
 	select {
-	case b.notificationRegistry <- dispatch:
+	case b.notificationRegistry <- ntfn.HistoricalDispatch:
 		return ntfn.Event, nil
 	case <-b.quit:
 		return nil, chainntnfs.ErrChainNotifierShuttingDown

chainntnfs/btcdnotify/btcd.go

@@ -11,6 +11,7 @@ import (
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/rpcclient"
+	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 	"github.com/lightningnetwork/lnd/chainntnfs"
@@ -50,8 +51,6 @@ type txUpdate struct {
 // notifications. Multiple concurrent clients are supported. All notifications
 // are achieved via non-blocking sends on client channels.
 type BtcdNotifier struct {
-	confClientCounter  uint64 // To be used aotmically.
-	spendClientCounter uint64 // To be used atomically.
 	epochClientCounter uint64 // To be used atomically.
 
 	started int32 // To be used atomically.
@@ -652,23 +651,11 @@ func (b *BtcdNotifier) notifyBlockEpochClient(epochClient *blockEpochRegistratio
 func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	pkScript []byte, heightHint uint32) (*chainntnfs.SpendEvent, error) {
 
-	// First, we'll construct a spend notification request and hand it off
+	// Register the conf notification with the TxNotifier. A non-nil value
-	// to the txNotifier.
+	// for `dispatch` will be returned if we are required to perform a
-	spendID := atomic.AddUint64(&b.spendClientCounter, 1)
+	// manual scan for the confirmation. Otherwise the notifier will begin
-	spendRequest, err := chainntnfs.NewSpendRequest(outpoint, pkScript)
+	// watching at tip for the transaction to confirm.
-	if err != nil {
+	ntfn, err := b.txNotifier.RegisterSpend(outpoint, pkScript, heightHint)
-		return nil, err
-	}
-	ntfn := &chainntnfs.SpendNtfn{
-		SpendID:      spendID,
-		SpendRequest: spendRequest,
-		Event: chainntnfs.NewSpendEvent(func() {
-			b.txNotifier.CancelSpend(spendRequest, spendID)
-		}),
-		HeightHint: heightHint,
-	}
-
-	historicalDispatch, _, err := b.txNotifier.RegisterSpend(ntfn)
 	if err != nil {
 		return nil, err
 	}
@@ -677,17 +664,18 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// outpoint/output script as spent.
 	//
 	// TODO(wilmer): use LoadFilter API instead.
-	if spendRequest.OutPoint == chainntnfs.ZeroOutPoint {
+	if outpoint == nil || *outpoint == chainntnfs.ZeroOutPoint {
-		addr, err := spendRequest.PkScript.Address(b.chainParams)
+		_, addrs, _, err := txscript.ExtractPkScriptAddrs(
+			pkScript, b.chainParams,
+		)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("unable to parse script: %v", err)
 		}
-		addrs := []btcutil.Address{addr}
 		if err := b.chainConn.NotifyReceived(addrs); err != nil {
 			return nil, err
 		}
 	} else {
-		ops := []*wire.OutPoint{&spendRequest.OutPoint}
+		ops := []*wire.OutPoint{outpoint}
 		if err := b.chainConn.NotifySpent(ops); err != nil {
 			return nil, err
 		}
@@ -696,7 +684,7 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// If the txNotifier didn't return any details to perform a historical
 	// scan of the chain, then we can return early as there's nothing left
 	// for us to do.
-	if historicalDispatch == nil {
+	if ntfn.HistoricalDispatch == nil {
 		return ntfn.Event, nil
 	}
 
@@ -706,26 +694,29 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// We'll short-circuit the path when dispatching the spend of a script,
 	// rather than an outpoint, as there aren't any additional checks we can
 	// make for scripts.
-	if spendRequest.OutPoint == chainntnfs.ZeroOutPoint {
+	if outpoint == nil || *outpoint == chainntnfs.ZeroOutPoint {
 		startHash, err := b.chainConn.GetBlockHash(
-			int64(historicalDispatch.StartHeight),
+			int64(ntfn.HistoricalDispatch.StartHeight),
 		)
 		if err != nil {
 			return nil, err
 		}
 
 		// TODO(wilmer): add retry logic if rescan fails?
-		addr, err := spendRequest.PkScript.Address(b.chainParams)
+		_, addrs, _, err := txscript.ExtractPkScriptAddrs(
+			pkScript, b.chainParams,
+		)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("unable to parse address: %v", err)
 		}
-		addrs := []btcutil.Address{addr}
+
 		asyncResult := b.chainConn.RescanAsync(startHash, addrs, nil)
 		go func() {
 			if rescanErr := asyncResult.Receive(); rescanErr != nil {
 				chainntnfs.Log.Errorf("Rescan to determine "+
 					"the spend details of %v failed: %v",
-					spendRequest, rescanErr)
+					ntfn.HistoricalDispatch.SpendRequest,
+					rescanErr)
 			}
 		}()
 
@@ -739,16 +730,16 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// We'll start by checking the backend's UTXO set to determine whether
 	// the outpoint has been spent. If it hasn't, we can return to the
 	// caller as well.
-	txOut, err := b.chainConn.GetTxOut(
+	txOut, err := b.chainConn.GetTxOut(&outpoint.Hash, outpoint.Index, true)
-		&spendRequest.OutPoint.Hash, spendRequest.OutPoint.Index, true,
-	)
 	if err != nil {
 		return nil, err
 	}
 	if txOut != nil {
 		// We'll let the txNotifier know the outpoint is still unspent
 		// in order to begin updating its spend hint.
-		err := b.txNotifier.UpdateSpendDetails(spendRequest, nil)
+		err := b.txNotifier.UpdateSpendDetails(
+			ntfn.HistoricalDispatch.SpendRequest, nil,
+		)
 		if err != nil {
 			return nil, err
 		}
@@ -760,25 +751,25 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// set, we'll determine when it happened by scanning the chain. We'll
 	// begin by fetching the block hash of our starting height.
 	startHash, err := b.chainConn.GetBlockHash(
-		int64(historicalDispatch.StartHeight),
+		int64(ntfn.HistoricalDispatch.StartHeight),
 	)
 	if err != nil {
 		return nil, fmt.Errorf("unable to get block hash for height "+
-			"%d: %v", historicalDispatch.StartHeight, err)
+			"%d: %v", ntfn.HistoricalDispatch.StartHeight, err)
 	}
 
 	// As a minimal optimization, we'll query the backend's transaction
 	// index (if enabled) to determine if we have a better rescan starting
 	// height. We can do this as the GetRawTransaction call will return the
 	// hash of the block it was included in within the chain.
-	tx, err := b.chainConn.GetRawTransactionVerbose(&spendRequest.OutPoint.Hash)
+	tx, err := b.chainConn.GetRawTransactionVerbose(&outpoint.Hash)
 	if err != nil {
 		// Avoid returning an error if the transaction was not found to
 		// proceed with fallback methods.
 		jsonErr, ok := err.(*btcjson.RPCError)
 		if !ok || jsonErr.Code != btcjson.ErrRPCNoTxInfo {
 			return nil, fmt.Errorf("unable to query for txid %v: %v",
-				spendRequest.OutPoint.Hash, err)
+				outpoint.Hash, err)
 		}
 	}
 
@@ -802,7 +793,7 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 				"block %v: %v", blockHash, err)
 		}
 
-		if uint32(blockHeader.Height) > historicalDispatch.StartHeight {
+		if uint32(blockHeader.Height) > ntfn.HistoricalDispatch.StartHeight {
 			startHash, err = b.chainConn.GetBlockHash(
 				int64(blockHeader.Height),
 			)
@@ -825,13 +816,12 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	//
 	// TODO(wilmer): add retry logic if rescan fails?
 	asyncResult := b.chainConn.RescanAsync(
-		startHash, nil, []*wire.OutPoint{&spendRequest.OutPoint},
+		startHash, nil, []*wire.OutPoint{outpoint},
 	)
 	go func() {
 		if rescanErr := asyncResult.Receive(); rescanErr != nil {
 			chainntnfs.Log.Errorf("Rescan to determine the spend "+
-				"details of %v failed: %v", spendRequest,
+				"details of %v failed: %v", outpoint, rescanErr)
-				rescanErr)
 		}
 	}()
 
@@ -851,41 +841,23 @@ func (b *BtcdNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
 	pkScript []byte,
 	numConfs, heightHint uint32) (*chainntnfs.ConfirmationEvent, error) {
 
-	// Construct a notification request for the transaction and send it to
-	// the main event loop.
-	confID := atomic.AddUint64(&b.confClientCounter, 1)
-	confRequest, err := chainntnfs.NewConfRequest(txid, pkScript)
-	if err != nil {
-		return nil, err
-	}
-	ntfn := &chainntnfs.ConfNtfn{
-		ConfID:           confID,
-		ConfRequest:      confRequest,
-		NumConfirmations: numConfs,
-		Event: chainntnfs.NewConfirmationEvent(numConfs, func() {
-			b.txNotifier.CancelConf(confRequest, confID)
-		}),
-		HeightHint: heightHint,
-	}
-
-	chainntnfs.Log.Infof("New confirmation subscription: %v, num_confs=%v ",
-		confRequest, numConfs)
-
 	// Register the conf notification with the TxNotifier. A non-nil value
 	// for `dispatch` will be returned if we are required to perform a
 	// manual scan for the confirmation. Otherwise the notifier will begin
 	// watching at tip for the transaction to confirm.
-	dispatch, _, err := b.txNotifier.RegisterConf(ntfn)
+	ntfn, err := b.txNotifier.RegisterConf(
+		txid, pkScript, numConfs, heightHint,
+	)
 	if err != nil {
 		return nil, err
 	}
 
-	if dispatch == nil {
+	if ntfn.HistoricalDispatch == nil {
 		return ntfn.Event, nil
 	}
 
 	select {
-	case b.notificationRegistry <- dispatch:
+	case b.notificationRegistry <- ntfn.HistoricalDispatch:
 		return ntfn.Event, nil
 	case <-b.quit:
 		return nil, chainntnfs.ErrChainNotifierShuttingDown

chainntnfs/neutrinonotify/neutrino.go

@@ -37,8 +37,6 @@ const (
 // TODO(roasbeef): heavily consolidate with NeutrinoNotifier code
 //  * maybe combine into single package?
 type NeutrinoNotifier struct {
-	confClientCounter  uint64 // To be used atomically.
-	spendClientCounter uint64 // To be used atomically.
 	epochClientCounter uint64 // To be used atomically.
 
 	started int32 // To be used atomically.
@@ -663,23 +661,11 @@ func (n *NeutrinoNotifier) notifyBlockEpochClient(epochClient *blockEpochRegistr
 func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	pkScript []byte, heightHint uint32) (*chainntnfs.SpendEvent, error) {
 
-	// First, we'll construct a spend notification request and hand it off
+	// Register the conf notification with the TxNotifier. A non-nil value
-	// to the txNotifier.
+	// for `dispatch` will be returned if we are required to perform a
-	spendID := atomic.AddUint64(&n.spendClientCounter, 1)
+	// manual scan for the confirmation. Otherwise the notifier will begin
-	spendRequest, err := chainntnfs.NewSpendRequest(outpoint, pkScript)
+	// watching at tip for the transaction to confirm.
-	if err != nil {
+	ntfn, err := n.txNotifier.RegisterSpend(outpoint, pkScript, heightHint)
-		return nil, err
-	}
-	ntfn := &chainntnfs.SpendNtfn{
-		SpendID:      spendID,
-		SpendRequest: spendRequest,
-		Event: chainntnfs.NewSpendEvent(func() {
-			n.txNotifier.CancelSpend(spendRequest, spendID)
-		}),
-		HeightHint: heightHint,
-	}
-
-	historicalDispatch, txNotifierTip, err := n.txNotifier.RegisterSpend(ntfn)
 	if err != nil {
 		return nil, err
 	}
@@ -691,9 +677,12 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	//
 	// We'll update our filter first to ensure we can immediately detect the
 	// spend at tip.
+	if outpoint == nil {
+		outpoint = &chainntnfs.ZeroOutPoint
+	}
 	inputToWatch := neutrino.InputWithScript{
-		OutPoint: spendRequest.OutPoint,
+		OutPoint: *outpoint,
-		PkScript: spendRequest.PkScript.Script(),
+		PkScript: pkScript,
 	}
 	updateOptions := []neutrino.UpdateOption{
 		neutrino.AddInputs(inputToWatch),
@@ -704,10 +693,9 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// update. In the case of an output script spend request, we'll check if
 	// we should perform a historical rescan and start from there, as we
 	// cannot do so with GetUtxo since it matches outpoints.
-	rewindHeight := txNotifierTip
+	rewindHeight := ntfn.Height
-	if historicalDispatch != nil &&
+	if ntfn.HistoricalDispatch != nil && *outpoint == chainntnfs.ZeroOutPoint {
-		spendRequest.OutPoint == chainntnfs.ZeroOutPoint {
+		rewindHeight = ntfn.HistoricalDispatch.StartHeight
-		rewindHeight = historicalDispatch.StartHeight
 	}
 	updateOptions = append(updateOptions, neutrino.Rewind(rewindHeight))
 
@@ -734,8 +722,7 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	// scan of the chain, or if we already performed one like in the case of
 	// output script spend requests, then we can return early as there's
 	// nothing left for us to do.
-	if historicalDispatch == nil ||
+	if ntfn.HistoricalDispatch == nil || *outpoint == chainntnfs.ZeroOutPoint {
-		spendRequest.OutPoint == chainntnfs.ZeroOutPoint {
 		return ntfn.Event, nil
 	}
 
@@ -753,7 +740,7 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 			currentHeight := uint32(n.bestBlock.Height)
 			n.bestBlockMtx.RUnlock()
 
-			if currentHeight >= historicalDispatch.StartHeight {
+			if currentHeight >= ntfn.HistoricalDispatch.StartHeight {
 				break
 			}
 
@@ -767,10 +754,10 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 		spendReport, err := n.p2pNode.GetUtxo(
 			neutrino.WatchInputs(inputToWatch),
 			neutrino.StartBlock(&waddrmgr.BlockStamp{
-				Height: int32(historicalDispatch.StartHeight),
+				Height: int32(ntfn.HistoricalDispatch.StartHeight),
 			}),
 			neutrino.EndBlock(&waddrmgr.BlockStamp{
-				Height: int32(historicalDispatch.EndHeight),
+				Height: int32(ntfn.HistoricalDispatch.EndHeight),
 			}),
 			neutrino.QuitChan(n.quit),
 		)
@@ -785,7 +772,7 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 		if spendReport != nil && spendReport.SpendingTx != nil {
 			spendingTxHash := spendReport.SpendingTx.TxHash()
 			spendDetails = &chainntnfs.SpendDetail{
-				SpentOutPoint:     &spendRequest.OutPoint,
+				SpentOutPoint:     outpoint,
 				SpenderTxHash:     &spendingTxHash,
 				SpendingTx:        spendReport.SpendingTx,
 				SpenderInputIndex: spendReport.SpendingInputIndex,
@@ -797,7 +784,9 @@ func (n *NeutrinoNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 		// not, we'll mark our historical rescan as complete to ensure the
 		// outpoint's spend hint gets updated upon connected/disconnected
 		// blocks.
-		err = n.txNotifier.UpdateSpendDetails(spendRequest, spendDetails)
+		err = n.txNotifier.UpdateSpendDetails(
+			ntfn.HistoricalDispatch.SpendRequest, spendDetails,
+		)
 		if err != nil {
 			chainntnfs.Log.Errorf("Failed to update spend details: %v", err)
 			return
@@ -820,31 +809,13 @@ func (n *NeutrinoNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
 	pkScript []byte,
 	numConfs, heightHint uint32) (*chainntnfs.ConfirmationEvent, error) {
 
-	// Construct a notification request for the transaction and send it to
-	// the main event loop.
-	confID := atomic.AddUint64(&n.confClientCounter, 1)
-	confRequest, err := chainntnfs.NewConfRequest(txid, pkScript)
-	if err != nil {
-		return nil, err
-	}
-	ntfn := &chainntnfs.ConfNtfn{
-		ConfID:           confID,
-		ConfRequest:      confRequest,
-		NumConfirmations: numConfs,
-		Event: chainntnfs.NewConfirmationEvent(numConfs, func() {
-			n.txNotifier.CancelConf(confRequest, confID)
-		}),
-		HeightHint: heightHint,
-	}
-
-	chainntnfs.Log.Infof("New confirmation subscription: %v, num_confs=%v",
-		confRequest, numConfs)
-
 	// Register the conf notification with the TxNotifier. A non-nil value
 	// for `dispatch` will be returned if we are required to perform a
 	// manual scan for the confirmation. Otherwise the notifier will begin
 	// watching at tip for the transaction to confirm.
-	dispatch, txNotifierTip, err := n.txNotifier.RegisterConf(ntfn)
+	ntfn, err := n.txNotifier.RegisterConf(
+		txid, pkScript, numConfs, heightHint,
+	)
 	if err != nil {
 		return nil, err
 	}
@@ -859,9 +830,7 @@ func (n *NeutrinoNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
 	// type so we can instruct neutrino to match if the transaction
 	// containing the script is found in a block.
 	params := n.p2pNode.ChainParams()
-	_, addrs, _, err := txscript.ExtractPkScriptAddrs(
+	_, addrs, _, err := txscript.ExtractPkScriptAddrs(pkScript, &params)
-		confRequest.PkScript.Script(), &params,
-	)
 	if err != nil {
 		return nil, fmt.Errorf("unable to extract script: %v", err)
 	}
@@ -873,7 +842,7 @@ func (n *NeutrinoNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
 	case n.notificationRegistry <- &rescanFilterUpdate{
 		updateOptions: []neutrino.UpdateOption{
 			neutrino.AddAddrs(addrs...),
-			neutrino.Rewind(txNotifierTip),
+			neutrino.Rewind(ntfn.Height),
 			neutrino.DisableDisconnectedNtfns(true),
 		},
 		errChan: errChan,
@@ -893,14 +862,14 @@ func (n *NeutrinoNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
 
 	// If a historical rescan was not requested by the txNotifier, then we
 	// can return to the caller.
-	if dispatch == nil {
+	if ntfn.HistoricalDispatch == nil {
 		return ntfn.Event, nil
 	}
 
 	// Finally, with the filter updated, we can dispatch the historical
 	// rescan to ensure we can detect if the event happened in the past.
 	select {
-	case n.notificationRegistry <- dispatch:
+	case n.notificationRegistry <- ntfn.HistoricalDispatch:
 	case <-n.quit:
 		return nil, chainntnfs.ErrChainNotifierShuttingDown
 	}

chainntnfs/txnotifier.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"sync"
+	"sync/atomic"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/txscript"
@@ -45,10 +46,22 @@ var (
 	// with the TxNotifier but it been shut down.
 	ErrTxNotifierExiting = errors.New("TxNotifier is exiting")
 
-	// ErrTxMaxConfs signals that the user requested a number of
+	// ErrNoScript is an error returned when a confirmation/spend
-	// confirmations beyond the reorg safety limit.
+	// registration is attempted without providing an accompanying output
-	ErrTxMaxConfs = fmt.Errorf("too many confirmations requested, max is %d",
+	// script.
-		MaxNumConfs)
+	ErrNoScript = errors.New("an output script must be provided")
+
+	// ErrNoHeightHint is an error returned when a confirmation/spend
+	// registration is attempted without providing an accompanying height
+	// hint.
+	ErrNoHeightHint = errors.New("a height hint greater than 0 must be " +
+		"provided")
+
+	// ErrNumConfsOutOfRange is an error returned when a confirmation/spend
+	// registration is attempted and the number of confirmations provided is
+	// out of range.
+	ErrNumConfsOutOfRange = fmt.Errorf("number of confirmations must be "+
+		"between %d and %d", 1, MaxNumConfs)
 )
 
 // rescanState indicates the progression of a registration before the notifier
@@ -255,6 +268,25 @@ type HistoricalConfDispatch struct {
 	EndHeight uint32
 }
 
+// ConfRegistration encompasses all of the information required for callers to
+// retrieve details about a confirmation event.
+type ConfRegistration struct {
+	// Event contains references to the channels that the notifications are
+	// to be sent over.
+	Event *ConfirmationEvent
+
+	// HistoricalDispatch, if non-nil, signals to the client who registered
+	// the notification that they are responsible for attempting to manually
+	// rescan blocks for the txid/output script between the start and end
+	// heights.
+	HistoricalDispatch *HistoricalConfDispatch
+
+	// Height is the height of the TxNotifier at the time the confirmation
+	// notification was registered. This can be used so that backends can
+	// request to be notified of confirmations from this point forwards.
+	Height uint32
+}
+
 // SpendRequest encapsulates a request for a spend notification of either an
 // outpoint or output script.
 type SpendRequest struct {
@@ -395,12 +427,34 @@ type HistoricalSpendDispatch struct {
 	EndHeight uint32
 }
 
+// SpendRegistration encompasses all of the information required for callers to
+// retrieve details about a spend event.
+type SpendRegistration struct {
+	// Event contains references to the channels that the notifications are
+	// to be sent over.
+	Event *SpendEvent
+
+	// HistoricalDispatch, if non-nil, signals to the client who registered
+	// the notification that they are responsible for attempting to manually
+	// rescan blocks for the txid/output script between the start and end
+	// heights.
+	HistoricalDispatch *HistoricalSpendDispatch
+
+	// Height is the height of the TxNotifier at the time the spend
+	// notification was registered. This can be used so that backends can
+	// request to be notified of spends from this point forwards.
+	Height uint32
+}
+
 // TxNotifier is a struct responsible for delivering transaction notifications
 // to subscribers. These notifications can be of two different types:
 // transaction/output script confirmations and/or outpoint/output script spends.
 // The TxNotifier will watch the blockchain as new blocks come in, in order to
 // satisfy its client requests.
 type TxNotifier struct {
+	confClientCounter  uint64 // To be used atomically.
+	spendClientCounter uint64 // To be used atomically.
+
 	// currentHeight is the height of the tracked blockchain. It is used to
 	// determine the number of confirmations a tx has and ensure blocks are
 	// connected and disconnected in order.
@@ -484,34 +538,72 @@ func NewTxNotifier(startHeight uint32, reorgSafetyLimit uint32,
 	}
 }
 
+// newConfNtfn validates all of the parameters required to successfully create
+// and register a confirmation notification.
+func (n *TxNotifier) newConfNtfn(txid *chainhash.Hash,
+	pkScript []byte, numConfs, heightHint uint32) (*ConfNtfn, error) {
+
+	// An accompanying output script must always be provided.
+	if len(pkScript) == 0 {
+		return nil, ErrNoScript
+	}
+
+	// Enforce that we will not dispatch confirmations beyond the reorg
+	// safety limit.
+	if numConfs == 0 || numConfs > n.reorgSafetyLimit {
+		return nil, ErrNumConfsOutOfRange
+	}
+
+	// A height hint must be provided to prevent scanning from the genesis
+	// block.
+	if heightHint == 0 {
+		return nil, ErrNoHeightHint
+	}
+
+	// Ensure the output script is of a supported type.
+	confRequest, err := NewConfRequest(txid, pkScript)
+	if err != nil {
+		return nil, err
+	}
+
+	confID := atomic.AddUint64(&n.confClientCounter, 1)
+	return &ConfNtfn{
+		ConfID:           confID,
+		ConfRequest:      confRequest,
+		NumConfirmations: numConfs,
+		Event: NewConfirmationEvent(numConfs, func() {
+			n.CancelConf(confRequest, confID)
+		}),
+		HeightHint: heightHint,
+	}, nil
+}
+
 // RegisterConf handles a new confirmation notification request. The client will
 // be notified when the transaction/output script gets a sufficient number of
-// confirmations in the blockchain. The registration succeeds if no error is
+// confirmations in the blockchain.
-// returned. If the returned HistoricalConfDispatch is non-nil, the caller is
-// responsible for attempting to manually rescan blocks for the txid/output
-// script between the start and end heights. The notifier's current height is
-// also returned so that backends can request to be notified of confirmations
-// from this point forwards.
 //
 // NOTE: If the transaction/output script has already been included in a block
 // on the chain, the confirmation details must be provided with the
 // UpdateConfDetails method, otherwise we will wait for the transaction/output
 // script to confirm even though it already has.
-func (n *TxNotifier) RegisterConf(ntfn *ConfNtfn) (*HistoricalConfDispatch,
+func (n *TxNotifier) RegisterConf(txid *chainhash.Hash, pkScript []byte,
-	uint32, error) {
+	numConfs, heightHint uint32) (*ConfRegistration, error) {
 
 	select {
 	case <-n.quit:
-		return nil, 0, ErrTxNotifierExiting
+		return nil, ErrTxNotifierExiting
 	default:
 	}
 
-	// Enforce that we will not dispatch confirmations beyond the reorg
+	// We'll start by performing a series of validation checks.
-	// safety limit.
+	ntfn, err := n.newConfNtfn(txid, pkScript, numConfs, heightHint)
-	if ntfn.NumConfirmations > n.reorgSafetyLimit {
+	if err != nil {
-		return nil, 0, ErrTxMaxConfs
+		return nil, err
 	}
 
+	Log.Infof("New confirmation subscription: %v, num_confs=%v ",
+		ntfn.ConfRequest, numConfs)
+
 	// Before proceeding to register the notification, we'll query our
 	// height hint cache to determine whether a better one exists.
 	//
@@ -557,9 +649,16 @@ func (n *TxNotifier) RegisterConf(ntfn *ConfNtfn) (*HistoricalConfDispatch,
 			"registration since rescan has finished",
 			ntfn.ConfRequest)
 
-		return nil, n.currentHeight, n.dispatchConfDetails(
+		err := n.dispatchConfDetails(ntfn, confSet.details)
-			ntfn, confSet.details,
+		if err != nil {
-		)
+			return nil, err
+		}
+
+		return &ConfRegistration{
+			Event:              ntfn.Event,
+			HistoricalDispatch: nil,
+			Height:             n.currentHeight,
+		}, nil
 
 	// A rescan is already in progress, return here to prevent dispatching
 	// another. When the rescan returns, this notification's details will be
@@ -568,7 +667,11 @@ func (n *TxNotifier) RegisterConf(ntfn *ConfNtfn) (*HistoricalConfDispatch,
 		Log.Debugf("Waiting for pending rescan to finish before "+
 			"notifying %v at tip", ntfn.ConfRequest)
 
-		return nil, n.currentHeight, nil
+		return &ConfRegistration{
+			Event:              ntfn.Event,
+			HistoricalDispatch: nil,
+			Height:             n.currentHeight,
+		}, nil
 
 	// If no rescan has been dispatched, attempt to do so now.
 	case rescanNotStarted:
@@ -587,7 +690,11 @@ func (n *TxNotifier) RegisterConf(ntfn *ConfNtfn) (*HistoricalConfDispatch,
 		// notifier to start delivering messages for this set
 		// immediately.
 		confSet.rescanStatus = rescanComplete
-		return nil, n.currentHeight, nil
+		return &ConfRegistration{
+			Event:              ntfn.Event,
+			HistoricalDispatch: nil,
+			Height:             n.currentHeight,
+		}, nil
 	}
 
 	Log.Debugf("Dispatching historical confirmation rescan for %v",
@@ -607,7 +714,11 @@ func (n *TxNotifier) RegisterConf(ntfn *ConfNtfn) (*HistoricalConfDispatch,
 	// registrations don't also attempt a dispatch.
 	confSet.rescanStatus = rescanPending
 
-	return dispatch, n.currentHeight, nil
+	return &ConfRegistration{
+		Event:              ntfn.Event,
+		HistoricalDispatch: dispatch,
+		Height:             n.currentHeight,
+	}, nil
 }
 
 // CancelConf cancels an existing request for a spend notification of an
@@ -818,29 +929,62 @@ func (n *TxNotifier) dispatchConfDetails(
 	return nil
 }
 
+// newSpendNtfn validates all of the parameters required to successfully create
+// and register a spend notification.
+func (n *TxNotifier) newSpendNtfn(outpoint *wire.OutPoint,
+	pkScript []byte, heightHint uint32) (*SpendNtfn, error) {
+
+	// An accompanying output script must always be provided.
+	if len(pkScript) == 0 {
+		return nil, ErrNoScript
+	}
+
+	// A height hint must be provided to prevent scanning from the genesis
+	// block.
+	if heightHint == 0 {
+		return nil, ErrNoHeightHint
+	}
+
+	// Ensure the output script is of a supported type.
+	spendRequest, err := NewSpendRequest(outpoint, pkScript)
+	if err != nil {
+		return nil, err
+	}
+
+	spendID := atomic.AddUint64(&n.spendClientCounter, 1)
+	return &SpendNtfn{
+		SpendID:      spendID,
+		SpendRequest: spendRequest,
+		Event: NewSpendEvent(func() {
+			n.CancelSpend(spendRequest, spendID)
+		}),
+		HeightHint: heightHint,
+	}, nil
+}
+
 // RegisterSpend handles a new spend notification request. The client will be
 // notified once the outpoint/output script is detected as spent within the
 // chain.
 //
-// The registration succeeds if no error is returned. If the returned
-// HistoricalSpendDisaptch is non-nil, the caller is responsible for attempting
-// to determine whether the outpoint/output script has been spent between the
-// start and end heights. The notifier's current height is also returned so that
-// backends can request to be notified of spends from this point forwards.
-//
 // NOTE: If the outpoint/output script has already been spent within the chain
 // before the notifier's current tip, the spend details must be provided with
 // the UpdateSpendDetails method, otherwise we will wait for the outpoint/output
 // script to be spent at tip, even though it already has.
-func (n *TxNotifier) RegisterSpend(ntfn *SpendNtfn) (*HistoricalSpendDispatch,
+func (n *TxNotifier) RegisterSpend(outpoint *wire.OutPoint, pkScript []byte,
-	uint32, error) {
+	heightHint uint32) (*SpendRegistration, error) {
 
 	select {
 	case <-n.quit:
-		return nil, 0, ErrTxNotifierExiting
+		return nil, ErrTxNotifierExiting
 	default:
 	}
 
+	// We'll start by performing a series of validation checks.
+	ntfn, err := n.newSpendNtfn(outpoint, pkScript, heightHint)
+	if err != nil {
+		return nil, err
+	}
+
 	// Before proceeding to register the notification, we'll query our spend
 	// hint cache to determine whether a better one exists.
 	startHeight := ntfn.HeightHint
@@ -886,9 +1030,16 @@ func (n *TxNotifier) RegisterSpend(ntfn *SpendNtfn) (*HistoricalSpendDispatch,
 			"registration since rescan has finished",
 			ntfn.SpendRequest)
 
-		return nil, n.currentHeight, n.dispatchSpendDetails(
+		err := n.dispatchSpendDetails(ntfn, spendSet.details)
-			ntfn, spendSet.details,
+		if err != nil {
-		)
+			return nil, err
+		}
+
+		return &SpendRegistration{
+			Event:              ntfn.Event,
+			HistoricalDispatch: nil,
+			Height:             n.currentHeight,
+		}, nil
 
 	// If there is an active rescan to determine whether the request has
 	// been spent, then we won't trigger another one.
@@ -896,7 +1047,11 @@ func (n *TxNotifier) RegisterSpend(ntfn *SpendNtfn) (*HistoricalSpendDispatch,
 		Log.Debugf("Waiting for pending rescan to finish before "+
 			"notifying %v at tip", ntfn.SpendRequest)
 
-		return nil, n.currentHeight, nil
+		return &SpendRegistration{
+			Event:              ntfn.Event,
+			HistoricalDispatch: nil,
+			Height:             n.currentHeight,
+		}, nil
 
 	// Otherwise, we'll fall through and let the caller know that a rescan
 	// should be dispatched to determine whether the request has already
@@ -916,7 +1071,11 @@ func (n *TxNotifier) RegisterSpend(ntfn *SpendNtfn) (*HistoricalSpendDispatch,
 		// spend hints for this request get updated upon
 		// connected/disconnected blocks.
 		spendSet.rescanStatus = rescanComplete
-		return nil, n.currentHeight, nil
+		return &SpendRegistration{
+			Event:              ntfn.Event,
+			HistoricalDispatch: nil,
+			Height:             n.currentHeight,
+		}, nil
 	}
 
 	// We'll set the rescan status to pending to ensure subsequent
@@ -926,11 +1085,15 @@ func (n *TxNotifier) RegisterSpend(ntfn *SpendNtfn) (*HistoricalSpendDispatch,
 	Log.Debugf("Dispatching historical spend rescan for %v",
 		ntfn.SpendRequest)
 
-	return &HistoricalSpendDispatch{
+	return &SpendRegistration{
-		SpendRequest: ntfn.SpendRequest,
+		Event: ntfn.Event,
-		StartHeight:  startHeight,
+		HistoricalDispatch: &HistoricalSpendDispatch{
-		EndHeight:    n.currentHeight,
+			SpendRequest: ntfn.SpendRequest,
-	}, n.currentHeight, nil
+			StartHeight:  startHeight,
+			EndHeight:    n.currentHeight,
+		},
+		Height: n.currentHeight,
+	}, nil
 }
 
 // CancelSpend cancels an existing request for a spend notification of an
@@ -1749,11 +1912,11 @@ func (n *TxNotifier) dispatchSpendReorg(ntfn *SpendNtfn) error {
 // closes the event channels of all registered notifications that have not been
 // dispatched yet.
 func (n *TxNotifier) TearDown() {
+	close(n.quit)
+
 	n.Lock()
 	defer n.Unlock()
 
-	close(n.quit)
-
 	for _, confSet := range n.confNotifications {
 		for _, ntfn := range confSet.ntfns {
 			close(ntfn.Event.Confirmed)

lnrpc/walletrpc/config_active.go

@@ -43,4 +43,8 @@ type Config struct {
 	// Sweeper is the central batching engine of lnd. It is responsible for
 	// sweeping inputs in batches back into the wallet.
 	Sweeper *sweep.UtxoSweeper
+
+	// Chain is an interface that the WalletKit will use to determine state
+	// about the backing chain of the wallet.
+	Chain lnwallet.BlockChainIO
 }

lnrpc/walletrpc/driver.go

@@ -51,6 +51,14 @@ func createNewSubServer(configRegistry lnrpc.SubServerConfigDispatcher) (lnrpc.S
 	case config.KeyRing == nil:
 		return nil, nil, fmt.Errorf("KeyRing must be set to create " +
 			"WalletKit RPC server")
+
+	case config.Sweeper == nil:
+		return nil, nil, fmt.Errorf("Sweeper must be set to create " +
+			"WalletKit RPC server")
+
+	case config.Chain == nil:
+		return nil, nil, fmt.Errorf("Chain must be set to create " +
+			"WalletKit RPC server")
 	}
 
 	return New(config)

lnrpc/walletrpc/walletkit_server.go

@@ -4,6 +4,7 @@ package walletrpc
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -496,27 +497,44 @@ func (w *WalletKit) BumpFee(ctx context.Context,
 	//
 	// We'll gather all of the information required by the UtxoSweeper in
 	// order to sweep the output.
-	txOut, err := w.cfg.Wallet.FetchInputInfo(op)
+	utxo, err := w.cfg.Wallet.FetchInputInfo(op)
 	if err != nil {
 		return nil, err
 	}
 
+	// We're only able to bump the fee of unconfirmed transactions.
+	if utxo.Confirmations > 0 {
+		return nil, errors.New("unable to bump fee of a confirmed " +
+			"transaction")
+	}
+
 	var witnessType input.WitnessType
-	switch {
+	switch utxo.AddressType {
-	case txscript.IsPayToWitnessPubKeyHash(txOut.PkScript):
+	case lnwallet.WitnessPubKey:
 		witnessType = input.WitnessKeyHash
-	case txscript.IsPayToScriptHash(txOut.PkScript):
+	case lnwallet.NestedWitnessPubKey:
 		witnessType = input.NestedWitnessKeyHash
 	default:
 		return nil, fmt.Errorf("unknown input witness %v", op)
 	}
 
 	signDesc := &input.SignDescriptor{
-		Output:   txOut,
+		Output: &wire.TxOut{
+			PkScript: utxo.PkScript,
+			Value:    int64(utxo.Value),
+		},
 		HashType: txscript.SigHashAll,
 	}
 
-	input := input.NewBaseInput(op, witnessType, signDesc, 0)
+	// We'll use the current height as the height hint since we're dealing
+	// with an unconfirmed transaction.
+	_, currentHeight, err := w.cfg.Chain.GetBestBlock()
+	if err != nil {
+		return nil, fmt.Errorf("unable to retrieve current height: %v",
+			err)
+	}
+
+	input := input.NewBaseInput(op, witnessType, signDesc, uint32(currentHeight))
 	if _, err = w.cfg.Sweeper.SweepInput(input, feePreference); err != nil {
 		return nil, err
 	}

lnwallet/btcwallet/btcwallet.go

@@ -59,11 +59,6 @@ type BtcWallet struct {
 	netParams *chaincfg.Params
 
 	chainKeyScope waddrmgr.KeyScope
-
-	// utxoCache is a cache used to speed up repeated calls to
-	// FetchInputInfo.
-	utxoCache map[wire.OutPoint]*wire.TxOut
-	cacheMtx  sync.RWMutex
 }
 
 // A compile time check to ensure that BtcWallet implements the
@@ -130,7 +125,6 @@ func New(cfg Config) (*BtcWallet, error) {
 		chain:         cfg.ChainSource,
 		netParams:     cfg.NetParams,
 		chainKeyScope: chainKeyScope,
-		utxoCache:     make(map[wire.OutPoint]*wire.TxOut),
 	}, nil
 }
 

lnwallet/btcwallet/signer.go

@@ -1,6 +1,8 @@
 package btcwallet
 
 import (
+	"fmt"
+
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/txscript"
@@ -21,22 +23,8 @@ import (
 // of ErrNotMine should be returned instead.
 //
 // This is a part of the WalletController interface.
-func (b *BtcWallet) FetchInputInfo(prevOut *wire.OutPoint) (*wire.TxOut, error) {
+func (b *BtcWallet) FetchInputInfo(prevOut *wire.OutPoint) (*lnwallet.Utxo, error) {
-	var (
+	// We manually look up the output within the tx store.
-		err    error
-		output *wire.TxOut
-	)
-
-	// First check to see if the output is already within the utxo cache.
-	// If so we can return directly saving a disk access.
-	b.cacheMtx.RLock()
-	if output, ok := b.utxoCache[*prevOut]; ok {
-		b.cacheMtx.RUnlock()
-		return output, nil
-	}
-	b.cacheMtx.RUnlock()
-
-	// Otherwise, we manually look up the output within the tx store.
 	txid := &prevOut.Hash
 	txDetail, err := base.UnstableAPI(b.wallet).TxDetails(txid)
 	if err != nil {
@@ -49,16 +37,40 @@ func (b *BtcWallet) FetchInputInfo(prevOut *wire.OutPoint) (*wire.TxOut, error)
 	// we actually have control of this output. We do this because the check
 	// above only guarantees that the transaction is somehow relevant to us,
 	// like in the event of us being the sender of the transaction.
-	output = txDetail.TxRecord.MsgTx.TxOut[prevOut.Index]
+	pkScript := txDetail.TxRecord.MsgTx.TxOut[prevOut.Index].PkScript
-	if _, err := b.fetchOutputAddr(output.PkScript); err != nil {
+	if _, err := b.fetchOutputAddr(pkScript); err != nil {
 		return nil, err
 	}
 
-	b.cacheMtx.Lock()
+	// Then, we'll populate all of the information required by the struct.
-	b.utxoCache[*prevOut] = output
+	addressType := lnwallet.UnknownAddressType
-	b.cacheMtx.Unlock()
+	switch {
+	case txscript.IsPayToWitnessPubKeyHash(pkScript):
+		addressType = lnwallet.WitnessPubKey
+	case txscript.IsPayToScriptHash(pkScript):
+		addressType = lnwallet.NestedWitnessPubKey
+	}
 
-	return output, nil
+	// Determine the number of confirmations the output currently has.
+	_, currentHeight, err := b.GetBestBlock()
+	if err != nil {
+		return nil, fmt.Errorf("unable to retrieve current height: %v",
+			err)
+	}
+	confs := int64(0)
+	if txDetail.Block.Height != -1 {
+		confs = int64(currentHeight - txDetail.Block.Height)
+	}
+
+	return &lnwallet.Utxo{
+		AddressType: addressType,
+		Value: btcutil.Amount(
+			txDetail.TxRecord.MsgTx.TxOut[prevOut.Index].Value,
+		),
+		PkScript:      pkScript,
+		Confirmations: confs,
+		OutPoint:      *prevOut,
+	}, nil
 }
 
 // fetchOutputAddr attempts to fetch the managed address corresponding to the

lnwallet/interface.go

@@ -59,8 +59,6 @@ type Utxo struct {
 	Value         btcutil.Amount
 	Confirmations int64
 	PkScript      []byte
-	RedeemScript  []byte
-	WitnessScript []byte
 	wire.OutPoint
 }
 
@@ -137,7 +135,7 @@ type WalletController interface {
 	// passed outpoint. If the base wallet determines this output is under
 	// its control, then the original txout should be returned.  Otherwise,
 	// a non-nil error value of ErrNotMine should be returned instead.
-	FetchInputInfo(prevOut *wire.OutPoint) (*wire.TxOut, error)
+	FetchInputInfo(prevOut *wire.OutPoint) (*Utxo, error)
 
 	// ConfirmedBalance returns the sum of all the wallet's unspent outputs
 	// that have at least confs confirmations. If confs is set to zero,

lnwallet/wallet.go

@@ -774,7 +774,10 @@ func (l *LightningWallet) handleContributionMsg(req *addContributionMsg) {
 			return
 		}
 
-		signDesc.Output = info
+		signDesc.Output = &wire.TxOut{
+			PkScript: info.PkScript,
+			Value:    int64(info.Value),
+		}
 		signDesc.InputIndex = i
 
 		inputScript, err := l.Cfg.Signer.ComputeInputScript(

mock.go

@@ -242,12 +242,15 @@ func (*mockWalletController) BackEnd() string {
 // FetchInputInfo will be called to get info about the inputs to the funding
 // transaction.
 func (*mockWalletController) FetchInputInfo(
-	prevOut *wire.OutPoint) (*wire.TxOut, error) {
+	prevOut *wire.OutPoint) (*lnwallet.Utxo, error) {
-	txOut := &wire.TxOut{
+	utxo := &lnwallet.Utxo{
-		Value:    int64(10 * btcutil.SatoshiPerBitcoin),
+		AddressType:   lnwallet.WitnessPubKey,
-		PkScript: []byte("dummy"),
+		Value:         10 * btcutil.SatoshiPerBitcoin,
+		PkScript:      []byte("dummy"),
+		Confirmations: 1,
+		OutPoint:      *prevOut,
 	}
-	return txOut, nil
+	return utxo, nil
 }
 func (*mockWalletController) ConfirmedBalance(confs int32) (btcutil.Amount, error) {
 	return 0, nil

subrpcserver_config.go

@@ -152,6 +152,9 @@ func (s *subRPCServerConfigs) PopulateDependencies(cc *chainControl,
 			subCfgValue.FieldByName("Sweeper").Set(
 				reflect.ValueOf(sweeper),
 			)
+			subCfgValue.FieldByName("Chain").Set(
+				reflect.ValueOf(cc.chainIO),
+			)
 
 		case *autopilotrpc.Config:
 			subCfgValue := extractReflectValue(subCfg)

sweep/walletsweep.go

@@ -101,11 +101,6 @@ type UtxoSource interface {
 	// ListUnspentWitness returns all UTXOs from the source that have
 	// between minConfs and maxConfs number of confirmations.
 	ListUnspentWitness(minConfs, maxConfs int32) ([]*lnwallet.Utxo, error)
-
-	// FetchInputInfo returns the matching output for an outpoint. If the
-	// outpoint doesn't belong to this UTXO source, then an error should be
-	// returned.
-	FetchInputInfo(*wire.OutPoint) (*wire.TxOut, error)
 }
 
 // CoinSelectionLocker is an interface that allows the caller to perform an
@@ -217,41 +212,34 @@ func CraftSweepAllTx(feeRate lnwallet.SatPerKWeight, blockHeight uint32,
 	// sweeper to generate and sign a transaction for us.
 	var inputsToSweep []input.Input
 	for _, output := range allOutputs {
-		// We'll consult the utxoSource for information concerning this
-		// outpoint, we'll need to properly populate a signDescriptor
-		// for this output.
-		outputInfo, err := utxoSource.FetchInputInfo(&output.OutPoint)
-		if err != nil {
-			unlockOutputs()
-
-			return nil, err
-		}
-
 		// As we'll be signing for outputs under control of the wallet,
 		// we only need to populate the output value and output script.
 		// The rest of the items will be populated internally within
 		// the sweeper via the witness generation function.
 		signDesc := &input.SignDescriptor{
-			Output:   outputInfo,
+			Output: &wire.TxOut{
+				PkScript: output.PkScript,
+				Value:    int64(output.Value),
+			},
 			HashType: txscript.SigHashAll,
 		}
 
-		pkScript := outputInfo.PkScript
+		pkScript := output.PkScript
 
 		// Based on the output type, we'll map it to the proper witness
 		// type so we can generate the set of input scripts needed to
 		// sweep the output.
 		var witnessType input.WitnessType
-		switch {
+		switch output.AddressType {
 
 		// If this is a p2wkh output, then we'll assume it's a witness
 		// key hash witness type.
-		case txscript.IsPayToWitnessPubKeyHash(pkScript):
+		case lnwallet.WitnessPubKey:
 			witnessType = input.WitnessKeyHash
 
 		// If this is a p2sh output, then as since it's under control
 		// of the wallet, we'll assume it's a nested p2sh output.
-		case txscript.IsPayToScriptHash(pkScript):
+		case lnwallet.NestedWitnessPubKey:
 			witnessType = input.NestedWitnessKeyHash
 
 		// All other output types we count as unknown and will fail to

sweep/walletsweep_test.go

@@ -108,25 +108,13 @@ func TestDetermineFeePerKw(t *testing.T) {
 }
 
 type mockUtxoSource struct {
-	outpoints map[wire.OutPoint]*wire.TxOut
-
 	outputs []*lnwallet.Utxo
 }
 
 func newMockUtxoSource(utxos []*lnwallet.Utxo) *mockUtxoSource {
-	m := &mockUtxoSource{
+	return &mockUtxoSource{
-		outputs:   utxos,
+		outputs: utxos,
-		outpoints: make(map[wire.OutPoint]*wire.TxOut),
 	}
-
-	for _, utxo := range utxos {
-		m.outpoints[utxo.OutPoint] = &wire.TxOut{
-			Value:    int64(utxo.Value),
-			PkScript: utxo.PkScript,
-		}
-	}
-
-	return m
 }
 
 func (m *mockUtxoSource) ListUnspentWitness(minConfs int32,
@@ -135,15 +123,6 @@ func (m *mockUtxoSource) ListUnspentWitness(minConfs int32,
 	return m.outputs, nil
 }
 
-func (m *mockUtxoSource) FetchInputInfo(op *wire.OutPoint) (*wire.TxOut, error) {
-	txOut, ok := m.outpoints[*op]
-	if !ok {
-		return nil, fmt.Errorf("no output found")
-	}
-
-	return txOut, nil
-}
-
 type mockCoinSelectionLocker struct {
 	fail bool
 }
@@ -202,6 +181,7 @@ var deliveryAddr = func() btcutil.Address {
 var testUtxos = []*lnwallet.Utxo{
 	{
 		// A p2wkh output.
+		AddressType: lnwallet.WitnessPubKey,
 		PkScript: []byte{
 			0x0, 0x14, 0x64, 0x3d, 0x8b, 0x15, 0x69, 0x4a, 0x54,
 			0x7d, 0x57, 0x33, 0x6e, 0x51, 0xdf, 0xfd, 0x38, 0xe3,
@@ -215,6 +195,7 @@ var testUtxos = []*lnwallet.Utxo{
 
 	{
 		// A np2wkh output.
+		AddressType: lnwallet.NestedWitnessPubKey,
 		PkScript: []byte{
 			0xa9, 0x14, 0x97, 0x17, 0xf7, 0xd1, 0x5f, 0x6f, 0x8b,
 			0x7, 0xe3, 0x58, 0x43, 0x19, 0xb9, 0x7e, 0xa9, 0x20,
@@ -228,6 +209,7 @@ var testUtxos = []*lnwallet.Utxo{
 
 	// A p2wsh output.
 	{
+		AddressType: lnwallet.UnknownAddressType,
 		PkScript: []byte{
 			0x0, 0x20, 0x70, 0x1a, 0x8d, 0x40, 0x1c, 0x84, 0xfb, 0x13,
 			0xe6, 0xba, 0xf1, 0x69, 0xd5, 0x96, 0x84, 0xe2, 0x7a, 0xbd,