sweep: add wallet inputs to reach dust limit

chainregistry.go

@@ -58,6 +58,10 @@ const (
 	// expressed in sat/kw.
 	defaultBitcoinStaticFeePerKW = chainfee.SatPerKWeight(12500)
 
+	// defaultBitcoinStaticMinRelayFeeRate is the min relay fee used for
+	// static estimators.
+	defaultBitcoinStaticMinRelayFeeRate = chainfee.FeePerKwFloor
+
 	// defaultLitecoinStaticFeePerKW is the fee rate of 200 sat/vbyte
 	// expressed in sat/kw.
 	defaultLitecoinStaticFeePerKW = chainfee.SatPerKWeight(50000)
@@ -163,7 +167,8 @@ func newChainControlFromConfig(cfg *config, chanDB *channeldb.DB,
 			TimeLockDelta: cfg.Bitcoin.TimeLockDelta,
 		}
 		cc.feeEstimator = chainfee.NewStaticEstimator(
-			defaultBitcoinStaticFeePerKW, 0,
+			defaultBitcoinStaticFeePerKW,
+			defaultBitcoinStaticMinRelayFeeRate,
 		)
 	case litecoinChain:
 		cc.routingPolicy = htlcswitch.ForwardingPolicy{

contractcourt/commit_sweep_resolver.go

@@ -206,7 +206,7 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
 	c.log.Infof("sweeping commit output")
 
 	feePref := sweep.FeePreference{ConfTarget: commitOutputConfTarget}
-	resultChan, err := c.Sweeper.SweepInput(inp, feePref)
+	resultChan, err := c.Sweeper.SweepInput(inp, sweep.Params{Fee: feePref})
 	if err != nil {
 		c.log.Errorf("unable to sweep input: %v", err)
 

contractcourt/commit_sweep_resolver_test.go

@@ -102,8 +102,8 @@ func newMockSweeper() *mockSweeper {
 	}
 }
 
-func (s *mockSweeper) SweepInput(input input.Input,
-	feePreference sweep.FeePreference) (chan sweep.Result, error) {
+func (s *mockSweeper) SweepInput(input input.Input, params sweep.Params) (
+	chan sweep.Result, error) {
 
 	s.sweptInputs <- input
 

contractcourt/interfaces.go

@@ -43,8 +43,8 @@ type OnionProcessor interface {
 // UtxoSweeper defines the sweep functions that contract court requires.
 type UtxoSweeper interface {
 	// SweepInput sweeps inputs back into the wallet.
-	SweepInput(input input.Input,
-		feePreference sweep.FeePreference) (chan sweep.Result, error)
+	SweepInput(input input.Input, params sweep.Params) (chan sweep.Result,
+		error)
 
 	// CreateSweepTx accepts a list of inputs and signs and generates a txn
 	// that spends from them. This method also makes an accurate fee

lnrpc/walletrpc/walletkit_server.go

@@ -536,7 +536,7 @@ func (w *WalletKit) BumpFee(ctx context.Context,
 	}
 
 	input := input.NewBaseInput(op, witnessType, signDesc, uint32(currentHeight))
-	if _, err = w.cfg.Sweeper.SweepInput(input, feePreference); err != nil {
+	if _, err = w.cfg.Sweeper.SweepInput(input, sweep.Params{Fee: feePreference}); err != nil {
 		return nil, err
 	}
 

server.go

@@ -792,10 +792,10 @@ func newServer(listenAddrs []net.Addr, chanDB *channeldb.DB,
 	}
 
 	s.sweeper = sweep.New(&sweep.UtxoSweeperConfig{
-		FeeEstimator:       cc.feeEstimator,
-		GenSweepScript:     newSweepPkScriptGen(cc.wallet),
-		Signer:             cc.wallet.Cfg.Signer,
-		PublishTransaction: cc.wallet.PublishTransaction,
+		FeeEstimator:   cc.feeEstimator,
+		GenSweepScript: newSweepPkScriptGen(cc.wallet),
+		Signer:         cc.wallet.Cfg.Signer,
+		Wallet:         cc.wallet,
 		NewBatchTimer: func() <-chan time.Time {
 			return time.NewTimer(sweep.DefaultBatchWindowDuration).C
 		},

sweep/backend_mock_test.go

@@ -2,6 +2,8 @@ package sweep
 
 import (
 	"sync"
+	"testing"
+	"time"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
@@ -11,6 +13,8 @@ import (
 // mockBackend simulates a chain backend for realistic behaviour in unit tests
 // around double spends.
 type mockBackend struct {
+	t *testing.T
+
 	lock sync.Mutex
 
 	notifier *MockNotifier
@@ -19,14 +23,20 @@ type mockBackend struct {
 
 	unconfirmedTxes        map[chainhash.Hash]*wire.MsgTx
 	unconfirmedSpendInputs map[wire.OutPoint]struct{}
+
+	publishChan chan wire.MsgTx
+
+	walletUtxos []*lnwallet.Utxo
 }
 
-func newMockBackend(notifier *MockNotifier) *mockBackend {
+func newMockBackend(t *testing.T, notifier *MockNotifier) *mockBackend {
 	return &mockBackend{
+		t:                      t,
 		notifier:               notifier,
 		unconfirmedTxes:        make(map[chainhash.Hash]*wire.MsgTx),
 		confirmedSpendInputs:   make(map[wire.OutPoint]struct{}),
 		unconfirmedSpendInputs: make(map[wire.OutPoint]struct{}),
+		publishChan:            make(chan wire.MsgTx, 2),
 	}
 }
 
@@ -65,6 +75,27 @@ func (b *mockBackend) publishTransaction(tx *wire.MsgTx) error {
 	return nil
 }
 
+func (b *mockBackend) PublishTransaction(tx *wire.MsgTx) error {
+	log.Tracef("Publishing tx %v", tx.TxHash())
+	err := b.publishTransaction(tx)
+	select {
+	case b.publishChan <- *tx:
+	case <-time.After(defaultTestTimeout):
+		b.t.Fatalf("unexpected tx published")
+	}
+	return err
+}
+
+func (b *mockBackend) ListUnspentWitness(minconfirms, maxconfirms int32) (
+	[]*lnwallet.Utxo, error) {
+
+	return b.walletUtxos, nil
+}
+
+func (b *mockBackend) WithCoinSelectLock(f func() error) error {
+	return f()
+}
+
 func (b *mockBackend) deleteUnconfirmed(txHash chainhash.Hash) {
 	b.lock.Lock()
 	defer b.lock.Unlock()

sweep/interface.go

@@ -0,0 +1,27 @@
+package sweep
+
+import (
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/lnwallet"
+)
+
+// Wallet contains all wallet related functionality required by sweeper.
+type Wallet interface {
+	// PublishTransaction performs cursory validation (dust checks, etc) and
+	// broadcasts the passed transaction to the Bitcoin network.
+	PublishTransaction(tx *wire.MsgTx) error
+
+	// ListUnspentWitness returns all unspent outputs which are version 0
+	// witness programs. The 'minconfirms' and 'maxconfirms' parameters
+	// indicate the minimum and maximum number of confirmations an output
+	// needs in order to be returned by this method.
+	ListUnspentWitness(minconfirms, maxconfirms int32) ([]*lnwallet.Utxo,
+		error)
+
+	// WithCoinSelectLock will execute the passed function closure in a
+	// synchronized manner preventing any coin selection operations from
+	// proceeding while the closure if executing. This can be seen as the
+	// ability to execute a function closure under an exclusive coin
+	// selection lock.
+	WithCoinSelectLock(f func() error) error
+}