multi: query circuit map inside contractcourt

This commit adds a new config method `QueryIncomingCircuit` that can be
used to query the payment's incoming circuit for giving its outgoing
circuit key.

contractcourt/chain_arbitrator.go

@@ -3,7 +3,6 @@ package contractcourt
 import (
 	"errors"
 	"fmt"
-	"math"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -14,6 +13,7 @@ import (
 	"github.com/btcsuite/btcwallet/walletdb"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/clock"
 	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
@@ -206,6 +206,17 @@ type ChainArbitratorConfig struct {
 
 	// Budget is the configured budget for the arbitrator.
 	Budget BudgetConfig
+
+	// QueryIncomingCircuit is used to find the outgoing HTLC's
+	// corresponding incoming HTLC circuit. It queries the circuit map for
+	// a given outgoing circuit key and returns the incoming circuit key.
+	//
+	// TODO(yy): this is a hacky way to get around the cycling import issue
+	// as we cannot import `htlcswitch` here. A proper way is to define an
+	// interface here that asks for method `LookupOpenCircuit`,
+	// meanwhile, turn `PaymentCircuit` into an interface or bring it to a
+	// lower package.
+	QueryIncomingCircuit func(circuit models.CircuitKey) *models.CircuitKey
 }
 
 // ChainArbitrator is a sub-system that oversees the on-chain resolution of all
@@ -389,9 +400,11 @@ func newActiveChannelArbitrator(channel *channeldb.OpenChannel,
 			return chanStateDB.FetchHistoricalChannel(&chanPoint)
 		},
 		FindOutgoingHTLCDeadline: func(
-			rHash chainhash.Hash) fn.Option[int32] {
+			htlc channeldb.HTLC) fn.Option[int32] {
 
-			return c.FindOutgoingHTLCDeadline(chanPoint, rHash)
+			return c.FindOutgoingHTLCDeadline(
+				channel.ShortChanID(), htlc,
+			)
 		},
 	}
 
@@ -612,9 +625,11 @@ func (c *ChainArbitrator) Start() error {
 				return chanStateDB.FetchHistoricalChannel(&chanPoint)
 			},
 			FindOutgoingHTLCDeadline: func(
-				rHash chainhash.Hash) fn.Option[int32] {
+				htlc channeldb.HTLC) fn.Option[int32] {
 
-				return c.FindOutgoingHTLCDeadline(chanPoint, rHash)
+				return c.FindOutgoingHTLCDeadline(
+					closeChanInfo.ShortChanID, htlc,
+				)
 			},
 		}
 		chanLog, err := newBoltArbitratorLog(
@@ -1224,22 +1239,48 @@ func (c *ChainArbitrator) SubscribeChannelEvents(
 // by the timeout height of its corresponding incoming HTLC - this is the
 // expiry height the that remote peer can spend his/her outgoing HTLC via the
 // timeout path.
-func (c *ChainArbitrator) FindOutgoingHTLCDeadline(chanPoint wire.OutPoint,
-	rHash chainhash.Hash) fn.Option[int32] {
+func (c *ChainArbitrator) FindOutgoingHTLCDeadline(scid lnwire.ShortChannelID,
+	outgoingHTLC channeldb.HTLC) fn.Option[int32] {
 
-	// minRefundTimeout tracks the minimal refund timeout found using the
-	// rHash. It's possible that we find multiple HTLCs living in different
-	// channels sharing the same rHash if an MPP is routed by us. In this
-	// case, we'll use the smallest refund timeout as the deadline.
-	//
-	// TODO(yy): can instead query the circuit map to find the exact HTLC.
-	minRefundTimeout := uint32(math.MaxInt32)
+	// Find the outgoing HTLC's corresponding incoming HTLC in the circuit
+	// map.
+	rHash := outgoingHTLC.RHash
+	circuit := models.CircuitKey{
+		ChanID: scid,
+		HtlcID: outgoingHTLC.HtlcIndex,
+	}
+	incomingCircuit := c.cfg.QueryIncomingCircuit(circuit)
 
-	// Iterate over all active channels to find the HTLC with the matching
-	// rHash.
+	// If there's no incoming circuit found, we will use the default
+	// deadline.
+	if incomingCircuit == nil {
+		log.Warnf("ChannelArbitrator(%v): incoming circuit key not "+
+			"found for rHash=%x, using default deadline instead",
+			scid, rHash)
+
+		return fn.None[int32]()
+	}
+
+	// If this is a locally initiated HTLC, it means we are the first hop.
+	// In this case, we can relax the deadline.
+	if incomingCircuit.ChanID.IsDefault() {
+		log.Infof("ChannelArbitrator(%v): using default deadline for "+
+			"locally initiated HTLC for rHash=%x", scid, rHash)
+
+		return fn.None[int32]()
+	}
+
+	log.Debugf("Found incoming circuit %v for rHash=%x using outgoing "+
+		"circuit %v", incomingCircuit, rHash, circuit)
+
+	c.Lock()
+	defer c.Unlock()
+
+	// Iterate over all active channels to find the incoming HTLC specified
+	// by its circuit key.
 	for cp, channelArb := range c.activeChannels {
-		// Skip the targeted channel as the incoming HTLC is not here.
-		if cp == chanPoint {
+		// Skip if the SCID doesn't match.
+		if channelArb.cfg.ShortChanID != incomingCircuit.ChanID {
 			continue
 		}
 
@@ -1247,32 +1288,25 @@ func (c *ChainArbitrator) FindOutgoingHTLCDeadline(chanPoint wire.OutPoint,
 		// HTLC.
 		for _, htlcs := range channelArb.activeHTLCs {
 			for _, htlc := range htlcs.incomingHTLCs {
-				if htlc.RHash != rHash {
+				// Skip if the index doesn't match.
+				if htlc.HtlcIndex != incomingCircuit.HtlcID {
 					continue
 				}
 
 				log.Debugf("ChannelArbitrator(%v): found "+
 					"incoming HTLC in channel=%v using "+
-					"rHash=%v, refundTimeout=%v", chanPoint,
+					"rHash=%x, refundTimeout=%v", scid,
 					cp, rHash, htlc.RefundTimeout)
 
-				// Update the value if it's smaller.
-				if minRefundTimeout > htlc.RefundTimeout {
-					minRefundTimeout = htlc.RefundTimeout
-				}
+				return fn.Some(int32(htlc.RefundTimeout))
 			}
 		}
 	}
 
-	// Return the refund timeout value if found.
-	if minRefundTimeout != math.MaxInt32 {
-		return fn.Some(int32(minRefundTimeout))
-	}
-
-	// If there's no incoming HTLC found, it means we are the first hop. In
-	// this case, we can relax the deadline.
-	log.Infof("ChannelArbitrator(%v): incoming HTLC not found for "+
-		"rHash=%v, using default deadline instead", chanPoint, rHash)
+	// If there's no incoming HTLC found, yet we have the incoming circuit,
+	// something is wrong - in this case, we return the none deadline.
+	log.Errorf("ChannelArbitrator(%v): incoming HTLC not found for "+
+		"rHash=%x, using default deadline instead", scid, rHash)
 
 	return fn.None[int32]()
 }

contractcourt/chain_arbitrator_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/clock"
 	"github.com/lightningnetwork/lnd/lntest/mock"
 	"github.com/lightningnetwork/lnd/lnwallet"
@@ -172,6 +173,11 @@ func TestResolveContract(t *testing.T) {
 		},
 		Clock:  clock.NewDefaultClock(),
 		Budget: *DefaultBudgetConfig(),
+		QueryIncomingCircuit: func(
+			circuit models.CircuitKey) *models.CircuitKey {
+
+			return nil
+		},
 	}
 	chainArb := NewChainArbitrator(
 		chainArbCfg, db,

contractcourt/channel_arbitrator.go

@@ -170,7 +170,7 @@ type ChannelArbitratorConfig struct {
 	// deadline is defined by the timeout height of its corresponding
 	// incoming HTLC - this is the expiry height the that remote peer can
 	// spend his/her outgoing HTLC via the timeout path.
-	FindOutgoingHTLCDeadline func(rHash chainhash.Hash) fn.Option[int32]
+	FindOutgoingHTLCDeadline func(htlc channeldb.HTLC) fn.Option[int32]
 
 	ChainArbitratorConfig
 }
@@ -764,7 +764,7 @@ func (c *ChannelArbitrator) relaunchResolvers(commitSet *CommitSet,
 		// the resolver with the expiry block height of its
 		// corresponding incoming HTLC.
 		if !htlc.Incoming {
-			deadline := c.cfg.FindOutgoingHTLCDeadline(htlc.RHash)
+			deadline := c.cfg.FindOutgoingHTLCDeadline(*htlc)
 			htlcResolver.SupplementDeadline(deadline)
 		}
 	}
@@ -2421,9 +2421,7 @@ func (c *ChannelArbitrator) prepContractResolutions(
 				// supplement the resolver with the expiry
 				// block height of its corresponding incoming
 				// HTLC.
-				deadline := c.cfg.FindOutgoingHTLCDeadline(
-					htlc.RHash,
-				)
+				deadline := c.cfg.FindOutgoingHTLCDeadline(htlc)
 				resolver.SupplementDeadline(deadline)
 
 				htlcResolvers = append(htlcResolvers, resolver)
@@ -2523,9 +2521,7 @@ func (c *ChannelArbitrator) prepContractResolutions(
 				// supplement the resolver with the expiry
 				// block height of its corresponding incoming
 				// HTLC.
-				deadline := c.cfg.FindOutgoingHTLCDeadline(
-					htlc.RHash,
-				)
+				deadline := c.cfg.FindOutgoingHTLCDeadline(htlc)
 				resolver.SupplementDeadline(deadline)
 
 				htlcResolvers = append(htlcResolvers, resolver)

contractcourt/channel_arbitrator_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/clock"
 	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
@@ -395,6 +396,11 @@ func createTestChannelArbitrator(t *testing.T, log ArbitratorLog,
 		Budget:     *DefaultBudgetConfig(),
 		PreimageDB: newMockWitnessBeacon(),
 		Registry:   &mockRegistry{},
+		QueryIncomingCircuit: func(
+			circuit models.CircuitKey) *models.CircuitKey {
+
+			return nil
+		},
 	}
 
 	// We'll use the resolvedChan to synchronize on call to
@@ -430,7 +436,7 @@ func createTestChannelArbitrator(t *testing.T, log ArbitratorLog,
 			return &channeldb.OpenChannel{}, nil
 		},
 		FindOutgoingHTLCDeadline: func(
-			rHash chainhash.Hash) fn.Option[int32] {
+			htlc channeldb.HTLC) fn.Option[int32] {
 
 			return fn.None[int32]()
 		},

contractcourt/commit_sweep_resolver_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lntest/mock"
@@ -43,6 +44,11 @@ func newCommitSweepResolverTestContext(t *testing.T,
 			Notifier: notifier,
 			Sweeper:  sweeper,
 			Budget:   *DefaultBudgetConfig(),
+			QueryIncomingCircuit: func(
+				circuit models.CircuitKey) *models.CircuitKey {
+
+				return nil
+			},
 		},
 		PutResolverReport: func(_ kvdb.RwTx,
 			_ *channeldb.ResolverReport) error {

contractcourt/htlc_incoming_contest_resolver_test.go

@@ -352,6 +352,11 @@ func newIncomingResolverTestContext(t *testing.T, isExit bool) *incomingResolver
 			},
 			HtlcNotifier: htlcNotifier,
 			Budget:       *DefaultBudgetConfig(),
+			QueryIncomingCircuit: func(
+				circuit models.CircuitKey) *models.CircuitKey {
+
+				return nil
+			},
 		},
 		PutResolverReport: func(_ kvdb.RwTx,
 			_ *channeldb.ResolverReport) error {

contractcourt/htlc_outgoing_contest_resolver_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lnmock"
@@ -153,6 +154,11 @@ func newOutgoingResolverTestContext(t *testing.T) *outgoingResolverTestContext {
 			},
 			OnionProcessor: onionProcessor,
 			Budget:         *DefaultBudgetConfig(),
+			QueryIncomingCircuit: func(
+				circuit models.CircuitKey) *models.CircuitKey {
+
+				return nil
+			},
 		},
 		PutResolverReport: func(_ kvdb.RwTx,
 			_ *channeldb.ResolverReport) error {

contractcourt/htlc_success_resolver_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/davecgh/go-spew/spew"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/kvdb"
@@ -92,6 +93,11 @@ func newHtlcResolverTestContext(t *testing.T,
 			},
 			HtlcNotifier: htlcNotifier,
 			Budget:       *DefaultBudgetConfig(),
+			QueryIncomingCircuit: func(
+				circuit models.CircuitKey) *models.CircuitKey {
+
+				return nil
+			},
 		},
 		PutResolverReport: func(_ kvdb.RwTx,
 			report *channeldb.ResolverReport) error {

contractcourt/htlc_timeout_resolver_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/input"
@@ -304,6 +305,9 @@ func TestHtlcTimeoutResolver(t *testing.T) {
 					return nil
 				},
 				Budget: *DefaultBudgetConfig(),
+				QueryIncomingCircuit: func(circuit models.CircuitKey) *models.CircuitKey {
+					return nil
+				},
 			},
 			PutResolverReport: func(_ kvdb.RwTx,
 				_ *channeldb.ResolverReport) error {

server.go

@@ -1134,6 +1134,7 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 		},
 	)
 
+	//nolint:lll
 	s.chainArb = contractcourt.NewChainArbitrator(contractcourt.ChainArbitratorConfig{
 		ChainHash:              *s.cfg.ActiveNetParams.GenesisHash,
 		IncomingBroadcastDelta: lncfg.DefaultIncomingBroadcastDelta,
@@ -1224,10 +1225,26 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 		PaymentsExpirationGracePeriod: cfg.PaymentsExpirationGracePeriod,
 		IsForwardedHTLC:               s.htlcSwitch.IsForwardedHTLC,
 		Clock:                         clock.NewDefaultClock(),
-		SubscribeBreachComplete:       s.breachArbitrator.SubscribeBreachComplete, //nolint:lll
-		PutFinalHtlcOutcome:           s.chanStateDB.PutOnchainFinalHtlcOutcome,   //nolint: lll
+		SubscribeBreachComplete:       s.breachArbitrator.SubscribeBreachComplete,
+		PutFinalHtlcOutcome:           s.chanStateDB.PutOnchainFinalHtlcOutcome,
 		HtlcNotifier:                  s.htlcNotifier,
 		Budget:                        *s.cfg.Sweeper.Budget,
+
+		// TODO(yy): remove this hack once PaymentCircuit is interfaced.
+		QueryIncomingCircuit: func(
+			circuit models.CircuitKey) *models.CircuitKey {
+
+			// Get the circuit map.
+			circuits := s.htlcSwitch.CircuitLookup()
+
+			// Lookup the outgoing circuit.
+			pc := circuits.LookupOpenCircuit(circuit)
+			if pc == nil {
+				return nil
+			}
+
+			return &pc.Incoming
+		},
 	}, dbs.ChanStateDB)
 
 	// Select the configuration and funding parameters for Bitcoin.