htlcswitch: continue threading contexts through

In preparation for `failAliasUpdate` and `createFailureWithUpdate`
calling `FetchLastChannelUpdate` which is a graph DB call that will
eventually take a context.

For `ForwardPackets`, we also make sure to
listen on the newly added context param at any location where we listen
on the `linkQuit` parameter.

This commit adds a few `context.TODO()` calls that will be addressed in
future commits.

Author: ellemouton

htlcswitch/interceptable_switch.go

@@ -316,7 +316,7 @@ func (s *InterceptableSwitch) run(ctx context.Context) error {
 				}
 			}
 			err := s.htlcSwitch.ForwardPackets(
-				packets.linkQuit, notIntercepted...,
+				ctx, packets.linkQuit, notIntercepted...,
 			)
 			if err != nil {
 				log.Errorf("Cannot forward packets: %v", err)
@@ -671,9 +671,10 @@ func (f *interceptedForward) Packet() InterceptedPacket {
 
 // Resume resumes the default behavior as if the packet was not intercepted.
 func (f *interceptedForward) Resume() error {
+	ctx := context.TODO()
 	// Forward to the switch. A link quit channel isn't needed, because we
 	// are on a different thread now.
-	return f.htlcSwitch.ForwardPackets(nil, f.packet)
+	return f.htlcSwitch.ForwardPackets(ctx, nil, f.packet)
 }
 
 // ResumeModified resumes the default behavior with field modifications. The
@@ -686,6 +687,8 @@ func (f *interceptedForward) ResumeModified(
 	outAmountMsat fn.Option[lnwire.MilliSatoshi],
 	outWireCustomRecords fn.Option[lnwire.CustomRecords]) error {
 
+	ctx := context.TODO()
+
 	// Convert the optional custom records to the correct type and validate
 	// them.
 	validatedRecords, err := fn.MapOptionZ(
@@ -742,7 +745,7 @@ func (f *interceptedForward) ResumeModified(
 
 	// Forward to the switch. A link quit channel isn't needed, because we
 	// are on a different thread now.
-	return f.htlcSwitch.ForwardPackets(nil, f.packet)
+	return f.htlcSwitch.ForwardPackets(ctx, nil, f.packet)
 }
 
 // Fail notifies the intention to Fail an existing hold forward with an
@@ -757,7 +760,7 @@ func (f *interceptedForward) Fail(reason []byte) error {
 
 // FailWithCode notifies the intention to fail an existing hold forward with the
 // specified failure code.
-func (f *interceptedForward) FailWithCode(_ context.Context,
+func (f *interceptedForward) FailWithCode(ctx context.Context,
 	code lnwire.FailCode) error {
 
 	shaOnionBlob := func() [32]byte {
@@ -785,7 +788,7 @@ func (f *interceptedForward) FailWithCode(_ context.Context,
 
 	case lnwire.CodeTemporaryChannelFailure:
 		update := f.htlcSwitch.failAliasUpdate(
-			f.packet.incomingChanID, true,
+			ctx, f.packet.incomingChanID, true,
 		)
 		if update == nil {
 			// Fallback to the original, non-alias behavior.

htlcswitch/interfaces.go

@@ -85,7 +85,7 @@ type dustHandler interface {
 type scidAliasHandler interface {
 	// attachFailAliasUpdate allows the link to properly fail incoming
 	// HTLCs on option_scid_alias channels.
-	attachFailAliasUpdate(failClosure func(
+	attachFailAliasUpdate(failClosure func(ctx context.Context,
 		sid lnwire.ShortChannelID,
 		incoming bool) *lnwire.ChannelUpdate1)
 

htlcswitch/link.go

@@ -263,7 +263,7 @@ type ChannelLinkConfig struct {
 
 	// FailAliasUpdate is a function used to fail an HTLC for an
 	// option_scid_alias channel.
-	FailAliasUpdate func(sid lnwire.ShortChannelID,
+	FailAliasUpdate func(ctx context.Context, sid lnwire.ShortChannelID,
 		incoming bool) *lnwire.ChannelUpdate1
 
 	// GetAliases is used by the link and switch to fetch the set of
@@ -859,8 +859,9 @@ type failCb func(update *lnwire.ChannelUpdate1) lnwire.FailureMessage
 // outgoing HTLC. It may return a FailureMessage that references a channel's
 // alias. If the channel does not have an alias, then the regular channel
 // update from disk will be returned.
-func (l *channelLink) createFailureWithUpdate(_ context.Context, incoming bool,
-	outgoingScid lnwire.ShortChannelID, cb failCb) lnwire.FailureMessage {
+func (l *channelLink) createFailureWithUpdate(ctx context.Context,
+	incoming bool, outgoingScid lnwire.ShortChannelID,
+	cb failCb) lnwire.FailureMessage {
 
 	// Determine which SCID to use in case we need to use aliases in the
 	// ChannelUpdate.
@@ -871,7 +872,7 @@ func (l *channelLink) createFailureWithUpdate(_ context.Context, incoming bool,
 
 	// Try using the FailAliasUpdate function. If it returns nil, fallback
 	// to the non-alias behavior.
-	update := l.cfg.FailAliasUpdate(scid, incoming)
+	update := l.cfg.FailAliasUpdate(ctx, scid, incoming)
 	if update == nil {
 		// Fallback to the non-alias behavior.
 		var err error
@@ -3209,7 +3210,7 @@ func (l *channelLink) getAliases() []lnwire.ShortChannelID {
 // attachFailAliasUpdate sets the link's FailAliasUpdate function.
 //
 // Part of the scidAliasHandler interface.
-func (l *channelLink) attachFailAliasUpdate(closure func(
+func (l *channelLink) attachFailAliasUpdate(closure func(ctx context.Context,
 	sid lnwire.ShortChannelID, incoming bool) *lnwire.ChannelUpdate1) {
 
 	l.Lock()

htlcswitch/link_test.go

@@ -2201,7 +2201,9 @@ func newSingleLinkTestHarness(t *testing.T, chanAmt,
 	forwardPackets := func(linkQuit <-chan struct{}, _ bool,
 		packets ...*htlcPacket) error {
 
-		return aliceSwitch.ForwardPackets(linkQuit, packets...)
+		return aliceSwitch.ForwardPackets(
+			context.Background(), linkQuit, packets...,
+		)
 	}
 
 	// Instantiate with a long interval, so that we can precisely control
@@ -4884,7 +4886,9 @@ func (h *persistentLinkHarness) restartLink(
 	forwardPackets := func(linkQuit <-chan struct{}, _ bool,
 		packets ...*htlcPacket) error {
 
-		return h.hSwitch.ForwardPackets(linkQuit, packets...)
+		return h.hSwitch.ForwardPackets(
+			context.Background(), linkQuit, packets...,
+		)
 	}
 
 	// Instantiate with a long interval, so that we can precisely control
@@ -6217,7 +6221,7 @@ func TestCheckHtlcForward(t *testing.T) {
 		return &lnwire.ChannelUpdate1{}, nil
 	}
 
-	failAliasUpdate := func(sid lnwire.ShortChannelID,
+	failAliasUpdate := func(_ context.Context, sid lnwire.ShortChannelID,
 		incoming bool) *lnwire.ChannelUpdate1 {
 
 		return nil

htlcswitch/mailbox.go

@@ -3,6 +3,7 @@ package htlcswitch
 import (
 	"bytes"
 	"container/list"
+	"context"
 	"errors"
 	"fmt"
 	"sync"
@@ -95,7 +96,8 @@ type mailBoxConfig struct {
 	// forwardPackets send a varidic number of htlcPackets to the switch to
 	// be routed. A quit channel should be provided so that the call can
 	// properly exit during shutdown.
-	forwardPackets func(<-chan struct{}, ...*htlcPacket) error
+	forwardPackets func(context.Context, <-chan struct{},
+		...*htlcPacket) error
 
 	// clock is a time source for the mailbox.
 	clock clock.Clock
@@ -107,7 +109,7 @@ type mailBoxConfig struct {
 
 	// failMailboxUpdate is used to fail an expired HTLC and use the
 	// correct SCID if the underlying channel uses aliases.
-	failMailboxUpdate func(outScid,
+	failMailboxUpdate func(ctx context.Context, outScid,
 		mailboxScid lnwire.ShortChannelID) lnwire.FailureMessage
 }
 
@@ -687,6 +689,8 @@ func (m *memoryMailBox) DustPackets() (lnwire.MilliSatoshi,
 // generated LinkError will show an OutgoingFailureDownstreamHtlcAdd
 // FailureDetail.
 func (m *memoryMailBox) FailAdd(pkt *htlcPacket) {
+	ctx := context.TODO()
+
 	// First, remove the packet from mailbox. If we didn't find the packet
 	// because it has already been acked, we'll exit early to avoid sending
 	// a duplicate fail message through the switch.
@@ -703,7 +707,7 @@ func (m *memoryMailBox) FailAdd(pkt *htlcPacket) {
 	// peer if this is a forward, or report to the user if the failed
 	// payment was locally initiated.
 	failure := m.cfg.failMailboxUpdate(
-		pkt.originalOutgoingChanID, m.cfg.shortChanID,
+		ctx, pkt.originalOutgoingChanID, m.cfg.shortChanID,
 	)
 
 	// If the payment was locally initiated (which is indicated by a nil
@@ -748,7 +752,7 @@ func (m *memoryMailBox) FailAdd(pkt *htlcPacket) {
 		},
 	}
 
-	if err := m.cfg.forwardPackets(m.quit, failPkt); err != nil {
+	if err := m.cfg.forwardPackets(ctx, m.quit, failPkt); err != nil {
 		log.Errorf("Unhandled error while reforwarding packets "+
 			"settle/fail over htlcswitch: %v", err)
 	}
@@ -804,7 +808,8 @@ type mailOrchConfig struct {
 	// forwardPackets send a varidic number of htlcPackets to the switch to
 	// be routed. A quit channel should be provided so that the call can
 	// properly exit during shutdown.
-	forwardPackets func(<-chan struct{}, ...*htlcPacket) error
+	forwardPackets func(context.Context, <-chan struct{},
+		...*htlcPacket) error
 
 	// clock is a time source for the generated mailboxes.
 	clock clock.Clock
@@ -816,7 +821,7 @@ type mailOrchConfig struct {
 
 	// failMailboxUpdate is used to fail an expired HTLC and use the
 	// correct SCID if the underlying channel uses aliases.
-	failMailboxUpdate func(outScid,
+	failMailboxUpdate func(ctx context.Context, outScid,
 		mailboxScid lnwire.ShortChannelID) lnwire.FailureMessage
 }
 

htlcswitch/mailbox_test.go

@@ -1,6 +1,7 @@
 package htlcswitch
 
 import (
+	"context"
 	prand "math/rand"
 	"reflect"
 	"testing"
@@ -206,7 +207,7 @@ func newMailboxContextWithClock(t *testing.T,
 		forwards: make(chan *htlcPacket, 1),
 	}
 
-	failMailboxUpdate := func(outScid,
+	failMailboxUpdate := func(_ context.Context, outScid,
 		mboxScid lnwire.ShortChannelID) lnwire.FailureMessage {
 
 		return &lnwire.FailTemporaryNodeFailure{}
@@ -232,7 +233,7 @@ func newMailboxContext(t *testing.T, startTime time.Time,
 		forwards: make(chan *htlcPacket, 1),
 	}
 
-	failMailboxUpdate := func(outScid,
+	failMailboxUpdate := func(_ context.Context, outScid,
 		mboxScid lnwire.ShortChannelID) lnwire.FailureMessage {
 
 		return &lnwire.FailTemporaryNodeFailure{}
@@ -250,7 +251,7 @@ func newMailboxContext(t *testing.T, startTime time.Time,
 	return ctx
 }
 
-func (c *mailboxContext) forward(_ <-chan struct{},
+func (c *mailboxContext) forward(_ context.Context, _ <-chan struct{},
 	pkts ...*htlcPacket) error {
 
 	for _, pkt := range pkts {
@@ -697,7 +698,7 @@ func testMailBoxDust(t *testing.T, chantype channeldb.ChannelType) {
 func TestMailOrchestrator(t *testing.T) {
 	t.Parallel()
 
-	failMailboxUpdate := func(outScid,
+	failMailboxUpdate := func(_ context.Context, outScid,
 		mboxScid lnwire.ShortChannelID) lnwire.FailureMessage {
 
 		return &lnwire.FailTemporaryNodeFailure{}
@@ -706,7 +707,7 @@ func TestMailOrchestrator(t *testing.T) {
 	// First, we'll create a new instance of our orchestrator.
 	mo := newMailOrchestrator(&mailOrchConfig{
 		failMailboxUpdate: failMailboxUpdate,
-		forwardPackets: func(_ <-chan struct{},
+		forwardPackets: func(_ context.Context, _ <-chan struct{},
 			pkts ...*htlcPacket) error {
 
 			return nil

htlcswitch/mock.go

@@ -735,7 +735,7 @@ type mockChannelLink struct {
 
 	checkHtlcForwardResult *LinkError
 
-	failAliasUpdate func(sid lnwire.ShortChannelID,
+	failAliasUpdate func(_ context.Context, sid lnwire.ShortChannelID,
 		incoming bool) *lnwire.ChannelUpdate1
 
 	confirmedZC bool
@@ -872,7 +872,8 @@ func (f *mockChannelLink) AttachMailBox(mailBox MailBox) {
 }
 
 func (f *mockChannelLink) attachFailAliasUpdate(closure func(
-	sid lnwire.ShortChannelID, incoming bool) *lnwire.ChannelUpdate1) {
+	ctx context.Context, sid lnwire.ShortChannelID,
+	incoming bool) *lnwire.ChannelUpdate1) {
 
 	f.failAliasUpdate = closure
 }