Merge pull request lightningnetwork#9687 from GeorgeTsagk/aux-trff-shpr-htlcview

`AuxTrafficShaper.PaymentBandwidth` uses HTLC view

Author: guggero

htlcswitch/interfaces.go

@@ -10,6 +10,7 @@ import (
 	"github.com/lightningnetwork/lnd/graph/db/models"
 	"github.com/lightningnetwork/lnd/invoices"
 	"github.com/lightningnetwork/lnd/lntypes"
+	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/record"
@@ -516,8 +517,8 @@ type AuxTrafficShaper interface {
 	// is a custom channel that should be handled by the traffic shaper, the
 	// ShouldHandleTraffic method should be called first.
 	PaymentBandwidth(htlcBlob, commitmentBlob fn.Option[tlv.Blob],
-		linkBandwidth,
-		htlcAmt lnwire.MilliSatoshi) (lnwire.MilliSatoshi, error)
+		linkBandwidth, htlcAmt lnwire.MilliSatoshi,
+		htlcView lnwallet.AuxHtlcView) (lnwire.MilliSatoshi, error)
 
 	// IsCustomHTLC returns true if the HTLC carries the set of relevant
 	// custom records to put it under the purview of the traffic shaper,

htlcswitch/link.go

@@ -3505,6 +3505,7 @@ func (l *channelLink) AuxBandwidth(amount lnwire.MilliSatoshi,
 	commitmentBlob := l.CommitmentCustomBlob()
 	auxBandwidth, err := ts.PaymentBandwidth(
 		htlcBlob, commitmentBlob, l.Bandwidth(), amount,
+		l.channel.FetchLatestAuxHTLCView(),
 	)
 	if err != nil {
 		return fn.Err[OptionalBandwidth](fmt.Errorf("failed to get "+

lnwallet/aux_leaf_store.go

@@ -133,7 +133,7 @@ type CommitDiffAuxInput struct {
 	// UnfilteredView is the unfiltered, original HTLC view of the channel.
 	// Unfiltered in this context means that the view contains all HTLCs,
 	// including the canceled ones.
-	UnfilteredView *HtlcView
+	UnfilteredView AuxHtlcView
 
 	// WhoseCommit denotes whose commitment transaction we are computing the
 	// diff for.
@@ -177,9 +177,8 @@ type AuxLeafStore interface {
 	// correspond to the passed aux blob, and an existing channel
 	// commitment.
 	FetchLeavesFromCommit(chanState AuxChanState,
-		commit channeldb.ChannelCommitment,
-		keyRing CommitmentKeyRing, whoseCommit lntypes.ChannelParty,
-	) fn.Result[CommitDiffAuxResult]
+		commit channeldb.ChannelCommitment, keyRing CommitmentKeyRing,
+		whoseCommit lntypes.ChannelParty) fn.Result[CommitDiffAuxResult]
 
 	// FetchLeavesFromRevocation attempts to fetch the auxiliary leaves
 	// from a channel revocation that stores balance + blob information.
@@ -206,7 +205,7 @@ func auxLeavesFromView(leafStore AuxLeafStore, chanState *channeldb.OpenChannel,
 			return leafStore.FetchLeavesFromView(CommitDiffAuxInput{
 				ChannelState:   NewAuxChanState(chanState),
 				PrevBlob:       blob,
-				UnfilteredView: originalView,
+				UnfilteredView: newAuxHtlcView(originalView),
 				WhoseCommit:    whoseCommit,
 				OurBalance:     ourBalance,
 				TheirBalance:   theirBalance,
@@ -227,13 +226,15 @@ func updateAuxBlob(leafStore AuxLeafStore, chanState *channeldb.OpenChannel,
 	return fn.MapOptionZ(
 		prevBlob, func(blob tlv.Blob) fn.Result[fn.Option[tlv.Blob]] {
 			return leafStore.ApplyHtlcView(CommitDiffAuxInput{
-				ChannelState:   NewAuxChanState(chanState),
-				PrevBlob:       blob,
-				UnfilteredView: nextViewUnfiltered,
-				WhoseCommit:    whoseCommit,
-				OurBalance:     ourBalance,
-				TheirBalance:   theirBalance,
-				KeyRing:        keyRing,
+				ChannelState: NewAuxChanState(chanState),
+				PrevBlob:     blob,
+				UnfilteredView: newAuxHtlcView(
+					nextViewUnfiltered,
+				),
+				WhoseCommit:  whoseCommit,
+				OurBalance:   ourBalance,
+				TheirBalance: theirBalance,
+				KeyRing:      keyRing,
 			})
 		},
 	)

lnwallet/aux_signer.go

@@ -5,6 +5,7 @@ import (
 	"github.com/lightningnetwork/lnd/fn/v2"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/lntypes"
+	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/tlv"
 )
@@ -13,6 +14,37 @@ import (
 // signatures within the custom data for an existing HTLC.
 var htlcCustomSigType tlv.TlvType65543
 
+// AuxHtlcView is a struct that contains a safe copy of an HTLC view that can
+// be used by aux components.
+type AuxHtlcView struct {
+	// NextHeight is the height of the commitment transaction that will be
+	// created using this view.
+	NextHeight uint64
+
+	// Updates is a Dual of the Local and Remote HTLCs.
+	Updates lntypes.Dual[[]AuxHtlcDescriptor]
+
+	// FeePerKw is the fee rate in sat/kw of the commitment transaction.
+	FeePerKw chainfee.SatPerKWeight
+}
+
+// newAuxHtlcView creates a new safe copy of the HTLC view that can be used by
+// aux components.
+//
+// NOTE: This function should only be called while holding the channel's read
+// lock, since the underlying local/remote payment descriptors are accessed
+// directly.
+func newAuxHtlcView(v *HtlcView) AuxHtlcView {
+	return AuxHtlcView{
+		NextHeight: v.NextHeight,
+		Updates: lntypes.Dual[[]AuxHtlcDescriptor]{
+			Local:  fn.Map(v.Updates.Local, newAuxHtlcDescriptor),
+			Remote: fn.Map(v.Updates.Remote, newAuxHtlcDescriptor),
+		},
+		FeePerKw: v.FeePerKw,
+	}
+}
+
 // AuxHtlcDescriptor is a struct that contains the information needed to sign or
 // verify an HTLC for custom channels.
 type AuxHtlcDescriptor struct {
@@ -99,6 +131,9 @@ func (a *AuxHtlcDescriptor) RemoveHeight(
 
 // newAuxHtlcDescriptor creates a new AuxHtlcDescriptor from a payment
 // descriptor.
+//
+// NOTE: This function should only be called while holding the channel's read
+// lock, since the underlying payment descriptors are accessed directly.
 func newAuxHtlcDescriptor(p *paymentDescriptor) AuxHtlcDescriptor {
 	return AuxHtlcDescriptor{
 		ChanID:                   p.ChanID,

lnwallet/channel.go

@@ -2704,6 +2704,20 @@ func (v *HtlcView) AuxTheirUpdates() []AuxHtlcDescriptor {
 	return fn.Map(v.Updates.Remote, newAuxHtlcDescriptor)
 }
 
+// FetchLatestAuxHTLCView returns the latest HTLC view of the lightning channel
+// as a safe copy that can be used outside the wallet code in concurrent access.
+func (lc *LightningChannel) FetchLatestAuxHTLCView() AuxHtlcView {
+	// This read lock is important, because we access both the local and
+	// remote log indexes as well as the underlying payment descriptors of
+	// the HTLCs when creating the view.
+	lc.RLock()
+	defer lc.RUnlock()
+
+	return newAuxHtlcView(lc.fetchHTLCView(
+		lc.updateLogs.Remote.logIndex, lc.updateLogs.Local.logIndex,
+	))
+}
+
 // fetchHTLCView returns all the candidate HTLC updates which should be
 // considered for inclusion within a commitment based on the passed HTLC log
 // indexes.

routing/bandwidth_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/go-errors/errors"
 	"github.com/lightningnetwork/lnd/fn/v2"
 	"github.com/lightningnetwork/lnd/htlcswitch"
+	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/tlv"
 	"github.com/stretchr/testify/require"
@@ -150,7 +151,8 @@ func (*mockTrafficShaper) ShouldHandleTraffic(_ lnwire.ShortChannelID,
 // is a custom channel that should be handled by the traffic shaper, the
 // HandleTraffic method should be called first.
 func (*mockTrafficShaper) PaymentBandwidth(_, _ fn.Option[tlv.Blob],
-	linkBandwidth, _ lnwire.MilliSatoshi) (lnwire.MilliSatoshi, error) {
+	linkBandwidth, _ lnwire.MilliSatoshi,
+	_ lnwallet.AuxHtlcView) (lnwire.MilliSatoshi, error) {
 
 	return linkBandwidth, nil
 }