Merge pull request #8805 from breez/jssdwt-insert-edge-when-not-found

localchans: recreate missing edge if not found

channeldb/graph.go

@@ -1023,6 +1023,10 @@ func (c *ChannelGraph) AddChannelEdge(edge *models.ChannelEdgeInfo,
 	}
 
 	for _, f := range op {
+		if f == nil {
+			return fmt.Errorf("nil scheduler option was used")
+		}
+
 		f(r)
 	}
 

cmd/commands/commands.go

@@ -2359,6 +2359,21 @@ var updateChannelPolicyCommand = cli.Command{
 				"channels will be updated. Takes the form of " +
 				"txid:output_index",
 		},
+		cli.BoolFlag{
+			Name: "create_missing_edge",
+			Usage: "Under unknown circumstances a channel can " +
+				"exist with a missing edge in the graph " +
+				"database. This can cause an 'edge not " +
+				"found' error when calling `getchaninfo` " +
+				"and/or cause the default channel policy to " +
+				"be used during forwards. Setting this flag " +
+				"will recreate the edge if not found, " +
+				"allowing updating this channel policy and " +
+				"fixing the missing edge problem for this " +
+				"channel permanently. For fields not set in " +
+				"this command, the default policy will be " +
+				"created.",
+		},
 	},
 	Action: actionDecorator(updateChannelPolicy),
 }
@@ -2518,11 +2533,14 @@ func updateChannelPolicy(ctx *cli.Context) error {
 		}
 	}
 
+	createMissingEdge := ctx.Bool("create_missing_edge")
+
 	req := &lnrpc.PolicyUpdateRequest{
-		BaseFeeMsat:   baseFee,
-		TimeLockDelta: uint32(timeLockDelta),
-		MaxHtlcMsat:   ctx.Uint64("max_htlc_msat"),
-		InboundFee:    inboundFee,
+		BaseFeeMsat:       baseFee,
+		TimeLockDelta:     uint32(timeLockDelta),
+		MaxHtlcMsat:       ctx.Uint64("max_htlc_msat"),
+		InboundFee:        inboundFee,
+		CreateMissingEdge: createMissingEdge,
 	}
 
 	if ctx.IsSet("min_htlc_msat") {

docs/release-notes/release-notes-0.18.4.md

@@ -84,6 +84,10 @@ types in a series of changes:
 
 ## lncli Additions
 
+* [`updatechanpolicy`](https://github.com/lightningnetwork/lnd/pull/8805) will
+  now update the channel policy if the edge was not found in the graph
+  database if the `create_missing_edge` flag is set.
+
 # Improvements
 ## Functional Updates
 ## RPC Updates

lnrpc/lightning.pb.go

@@ -15183,6 +15183,14 @@ type PolicyUpdateRequest struct {
 	// Optional inbound fee. If unset, the previously set value will be
 	// retained [EXPERIMENTAL].
 	InboundFee *InboundFee `protobuf:"bytes,10,opt,name=inbound_fee,json=inboundFee,proto3" json:"inbound_fee,omitempty"`
+	// Under unknown circumstances a channel can exist with a missing edge in
+	// the graph database. This can cause an 'edge not found' error when calling
+	// `getchaninfo` and/or cause the default channel policy to be used during
+	// forwards. Setting this flag will recreate the edge if not found, allowing
+	// updating this channel policy and fixing the missing edge problem for this
+	// channel permanently. For fields not set in this command, the default
+	// policy will be created.
+	CreateMissingEdge bool `protobuf:"varint,11,opt,name=create_missing_edge,json=createMissingEdge,proto3" json:"create_missing_edge,omitempty"`
 }
 
 func (x *PolicyUpdateRequest) Reset() {
@@ -15294,6 +15302,13 @@ func (x *PolicyUpdateRequest) GetInboundFee() *InboundFee {
 	return nil
 }
 
+func (x *PolicyUpdateRequest) GetCreateMissingEdge() bool {
+	if x != nil {
+		return x.CreateMissingEdge
+	}
+	return false
+}
+
 type isPolicyUpdateRequest_Scope interface {
 	isPolicyUpdateRequest_Scope()
 }
@@ -20763,7 +20778,7 @@ var file_lightning_proto_rawDesc = []byte{
 	0x65, 0x65, 0x5f, 0x6d, 0x73, 0x61, 0x74, 0x18, 0x01, 0x20, 0x01, 0x28, 0x05, 0x52, 0x0b, 0x62,
 	0x61, 0x73, 0x65, 0x46, 0x65, 0x65, 0x4d, 0x73, 0x61, 0x74, 0x12, 0x20, 0x0a, 0x0c, 0x66, 0x65,
 	0x65, 0x5f, 0x72, 0x61, 0x74, 0x65, 0x5f, 0x70, 0x70, 0x6d, 0x18, 0x02, 0x20, 0x01, 0x28, 0x05,
-	0x52, 0x0a, 0x66, 0x65, 0x65, 0x52, 0x61, 0x74, 0x65, 0x50, 0x70, 0x6d, 0x22, 0xaa, 0x03, 0x0a,
+	0x52, 0x0a, 0x66, 0x65, 0x65, 0x52, 0x61, 0x74, 0x65, 0x50, 0x70, 0x6d, 0x22, 0xda, 0x03, 0x0a,
 	0x13, 0x50, 0x6f, 0x6c, 0x69, 0x63, 0x79, 0x55, 0x70, 0x64, 0x61, 0x74, 0x65, 0x52, 0x65, 0x71,
 	0x75, 0x65, 0x73, 0x74, 0x12, 0x18, 0x0a, 0x06, 0x67, 0x6c, 0x6f, 0x62, 0x61, 0x6c, 0x18, 0x01,
 	0x20, 0x01, 0x28, 0x08, 0x48, 0x00, 0x52, 0x06, 0x67, 0x6c, 0x6f, 0x62, 0x61, 0x6c, 0x12, 0x34,
@@ -20790,6 +20805,9 @@ var file_lightning_proto_rawDesc = []byte{
 	0x69, 0x6e, 0x62, 0x6f, 0x75, 0x6e, 0x64, 0x5f, 0x66, 0x65, 0x65, 0x18, 0x0a, 0x20, 0x01, 0x28,
 	0x0b, 0x32, 0x11, 0x2e, 0x6c, 0x6e, 0x72, 0x70, 0x63, 0x2e, 0x49, 0x6e, 0x62, 0x6f, 0x75, 0x6e,
 	0x64, 0x46, 0x65, 0x65, 0x52, 0x0a, 0x69, 0x6e, 0x62, 0x6f, 0x75, 0x6e, 0x64, 0x46, 0x65, 0x65,
+	0x12, 0x2e, 0x0a, 0x13, 0x63, 0x72, 0x65, 0x61, 0x74, 0x65, 0x5f, 0x6d, 0x69, 0x73, 0x73, 0x69,
+	0x6e, 0x67, 0x5f, 0x65, 0x64, 0x67, 0x65, 0x18, 0x0b, 0x20, 0x01, 0x28, 0x08, 0x52, 0x11, 0x63,
+	0x72, 0x65, 0x61, 0x74, 0x65, 0x4d, 0x69, 0x73, 0x73, 0x69, 0x6e, 0x67, 0x45, 0x64, 0x67, 0x65,
 	0x42, 0x07, 0x0a, 0x05, 0x73, 0x63, 0x6f, 0x70, 0x65, 0x22, 0x8c, 0x01, 0x0a, 0x0c, 0x46, 0x61,
 	0x69, 0x6c, 0x65, 0x64, 0x55, 0x70, 0x64, 0x61, 0x74, 0x65, 0x12, 0x2b, 0x0a, 0x08, 0x6f, 0x75,
 	0x74, 0x70, 0x6f, 0x69, 0x6e, 0x74, 0x18, 0x01, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x0f, 0x2e, 0x6c,

lnrpc/lightning.proto

@@ -4558,6 +4558,15 @@ message PolicyUpdateRequest {
     // Optional inbound fee. If unset, the previously set value will be
     // retained [EXPERIMENTAL].
     InboundFee inbound_fee = 10;
+
+    // Under unknown circumstances a channel can exist with a missing edge in
+    // the graph database. This can cause an 'edge not found' error when calling
+    // `getchaninfo` and/or cause the default channel policy to be used during
+    // forwards. Setting this flag will recreate the edge if not found, allowing
+    // updating this channel policy and fixing the missing edge problem for this
+    // channel permanently. For fields not set in this command, the default
+    // policy will be created.
+    bool create_missing_edge = 11;
 }
 
 enum UpdateFailure {

lnrpc/lightning.swagger.json

@@ -6751,6 +6751,10 @@
         "inbound_fee": {
           "$ref": "#/definitions/lnrpcInboundFee",
           "description": "Optional inbound fee. If unset, the previously set value will be\nretained [EXPERIMENTAL]."
+        },
+        "create_missing_edge": {
+          "type": "boolean",
+          "description": "Under unknown circumstances a channel can exist with a missing edge in\nthe graph database. This can cause an 'edge not found' error when calling\n`getchaninfo` and/or cause the default channel policy to be used during\nforwards. Setting this flag will recreate the edge if not found, allowing\nupdating this channel policy and fixing the missing edge problem for this\nchannel permanently. For fields not set in this command, the default\npolicy will be created."
         }
       }
     },

log.go

@@ -46,6 +46,7 @@ import (
 	"github.com/lightningnetwork/lnd/peernotifier"
 	"github.com/lightningnetwork/lnd/routing"
 	"github.com/lightningnetwork/lnd/routing/blindedpath"
+	"github.com/lightningnetwork/lnd/routing/localchans"
 	"github.com/lightningnetwork/lnd/rpcperms"
 	"github.com/lightningnetwork/lnd/signal"
 	"github.com/lightningnetwork/lnd/sweep"
@@ -172,6 +173,7 @@ func SetupLoggers(root *build.SubLoggerManager, interceptor signal.Interceptor)
 	AddSubLogger(root, "CHFD", interceptor, chanfunding.UseLogger)
 	AddSubLogger(root, "PEER", interceptor, peer.UseLogger)
 	AddSubLogger(root, "CHCL", interceptor, chancloser.UseLogger)
+	AddSubLogger(root, "LCHN", interceptor, localchans.UseLogger)
 
 	AddSubLogger(root, routing.Subsystem, interceptor, routing.UseLogger)
 	AddSubLogger(root, routerrpc.Subsystem, interceptor, routerrpc.UseLogger)

routing/localchans/log.go

@@ -0,0 +1,31 @@
+package localchans
+
+import (
+	"github.com/btcsuite/btclog/v2"
+	"github.com/lightningnetwork/lnd/build"
+)
+
+// log is a logger that is initialized with no output filters.  This means the
+// package will not perform any logging by default until the caller requests
+// it.
+var log btclog.Logger
+
+const Subsystem = "LCHN"
+
+// The default amount of logging is none.
+func init() {
+	UseLogger(build.NewSubLogger(Subsystem, nil))
+}
+
+// DisableLog disables all library log output.  Logging output is disabled by
+// default until UseLogger is called.
+func DisableLog() {
+	UseLogger(btclog.Disabled)
+}
+
+// UseLogger uses a specified Logger to output package logging info.  This
+// should be used in preference to SetLogWriter if the caller is also using
+// btclog.
+func UseLogger(logger btclog.Logger) {
+	log = logger
+}

routing/localchans/manager.go

@@ -1,10 +1,13 @@
 package localchans
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"sync"
+	"time"
 
+	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channeldb/models"
@@ -19,6 +22,12 @@ import (
 // Manager manages the node's local channels. The only operation that is
 // currently implemented is updating forwarding policies.
 type Manager struct {
+	// SelfPub contains the public key of the local node.
+	SelfPub *btcec.PublicKey
+
+	// DefaultRoutingPolicy is the default routing policy.
+	DefaultRoutingPolicy models.ForwardingPolicy
+
 	// UpdateForwardingPolicies is used by the manager to update active
 	// links with a new policy.
 	UpdateForwardingPolicies func(
@@ -30,7 +39,7 @@ type Manager struct {
 		edgesToUpdate []discovery.EdgeWithInfo) error
 
 	// ForAllOutgoingChannels is required to iterate over all our local
-	// channels.
+	// channels. The ChannelEdgePolicy parameter may be nil.
 	ForAllOutgoingChannels func(cb func(kvdb.RTx,
 		*models.ChannelEdgeInfo,
 		*models.ChannelEdgePolicy) error) error
@@ -40,6 +49,9 @@ type Manager struct {
 	FetchChannel func(tx kvdb.RTx, chanPoint wire.OutPoint) (
 		*channeldb.OpenChannel, error)
 
+	// AddEdge is used to add edge/channel to the topology of the router.
+	AddEdge func(edge *models.ChannelEdgeInfo) error
+
 	// policyUpdateLock ensures that the database and the link do not fall
 	// out of sync if there are concurrent fee update calls. Without it,
 	// there is a chance that policy A updates the database, then policy B
@@ -51,7 +63,8 @@ type Manager struct {
 // UpdatePolicy updates the policy for the specified channels on disk and in
 // the active links.
 func (r *Manager) UpdatePolicy(newSchema routing.ChannelPolicy,
-	chanPoints ...wire.OutPoint) ([]*lnrpc.FailedUpdate, error) {
+	createMissingEdge bool, chanPoints ...wire.OutPoint) (
+	[]*lnrpc.FailedUpdate, error) {
 
 	r.policyUpdateLock.Lock()
 	defer r.policyUpdateLock.Unlock()
@@ -69,10 +82,8 @@ func (r *Manager) UpdatePolicy(newSchema routing.ChannelPolicy,
 	var edgesToUpdate []discovery.EdgeWithInfo
 	policiesToUpdate := make(map[wire.OutPoint]models.ForwardingPolicy)
 
-	// Next, we'll loop over all the outgoing channels the router knows of.
-	// If we have a filter then we'll only collected those channels,
-	// otherwise we'll collect them all.
-	err := r.ForAllOutgoingChannels(func(
+	// NOTE: edge may be nil when this function is called.
+	processChan := func(
 		tx kvdb.RTx,
 		info *models.ChannelEdgeInfo,
 		edge *models.ChannelEdgePolicy) error {
@@ -88,8 +99,24 @@ func (r *Manager) UpdatePolicy(newSchema routing.ChannelPolicy,
 		// will be used to report invalid channels later on.
 		delete(unprocessedChans, info.ChannelPoint)
 
+		if edge == nil {
+			log.Errorf("Got nil channel edge policy when updating "+
+				"a channel. Channel point: %v",
+				info.ChannelPoint.String())
+
+			failedUpdates = append(failedUpdates, makeFailureItem(
+				info.ChannelPoint,
+				lnrpc.UpdateFailure_UPDATE_FAILURE_NOT_FOUND,
+				"edge policy not found",
+			))
+
+			return nil
+		}
+
 		// Apply the new policy to the edge.
-		err := r.updateEdge(tx, info.ChannelPoint, edge, newSchema)
+		err := r.updateEdge(
+			tx, info.ChannelPoint, edge, newSchema,
+		)
 		if err != nil {
 			failedUpdates = append(failedUpdates,
 				makeFailureItem(info.ChannelPoint,
@@ -125,7 +152,12 @@ func (r *Manager) UpdatePolicy(newSchema routing.ChannelPolicy,
 		}
 
 		return nil
-	})
+	}
+
+	// Next, we'll loop over all the outgoing channels the router knows of.
+	// If we have a filter then we'll only collect those channels, otherwise
+	// we'll collect them all.
+	err := r.ForAllOutgoingChannels(processChan)
 	if err != nil {
 		return nil, err
 	}
@@ -155,7 +187,37 @@ func (r *Manager) UpdatePolicy(newSchema routing.ChannelPolicy,
 					"not yet confirmed",
 				))
 
+		// If the edge was not found, but the channel is found, that
+		// means the edge is missing in the graph database and should be
+		// recreated. The edge and policy are created in-memory. The
+		// edge is inserted in createEdge below and the policy will be
+		// added to the graph in the PropagateChanPolicyUpdate call
+		// below.
+		case createMissingEdge:
+			log.Warnf("Missing edge for active channel (%s) "+
+				"during policy update. Recreating edge with "+
+				"default policy.",
+				channel.FundingOutpoint.String())
+
+			info, edge, failedUpdate := r.createMissingEdge(
+				channel, newSchema,
+			)
+			if failedUpdate == nil {
+				err = processChan(nil, info, edge)
+				if err != nil {
+					return nil, err
+				}
+			} else {
+				failedUpdates = append(
+					failedUpdates, failedUpdate,
+				)
+			}
+
 		default:
+			log.Warnf("Missing edge for active channel (%s) "+
+				"during policy update. Could not update "+
+				"policy.", channel.FundingOutpoint.String())
+
 			failedUpdates = append(failedUpdates,
 				makeFailureItem(chanPoint,
 					lnrpc.UpdateFailure_UPDATE_FAILURE_UNKNOWN,
@@ -180,11 +242,124 @@ func (r *Manager) UpdatePolicy(newSchema routing.ChannelPolicy,
 	return failedUpdates, nil
 }
 
+func (r *Manager) createMissingEdge(channel *channeldb.OpenChannel,
+	newSchema routing.ChannelPolicy) (*models.ChannelEdgeInfo,
+	*models.ChannelEdgePolicy, *lnrpc.FailedUpdate) {
+
+	info, edge, err := r.createEdge(channel, time.Now())
+	if err != nil {
+		log.Errorf("Failed to recreate missing edge "+
+			"for channel (%s): %v",
+			channel.FundingOutpoint.String(), err)
+
+		return nil, nil, makeFailureItem(
+			channel.FundingOutpoint,
+			lnrpc.UpdateFailure_UPDATE_FAILURE_UNKNOWN,
+			"could not update policies",
+		)
+	}
+
+	// Validate the newly created edge policy with the user defined new
+	// schema before adding the edge to the database.
+	err = r.updateEdge(nil, channel.FundingOutpoint, edge, newSchema)
+	if err != nil {
+		return nil, nil, makeFailureItem(
+			info.ChannelPoint,
+			lnrpc.UpdateFailure_UPDATE_FAILURE_INVALID_PARAMETER,
+			err.Error(),
+		)
+	}
+
+	// Insert the edge into the database to avoid `edge not
+	// found` errors during policy update propagation.
+	err = r.AddEdge(info)
+	if err != nil {
+		log.Errorf("Attempt to add missing edge for "+
+			"channel (%s) errored with: %v",
+			channel.FundingOutpoint.String(), err)
+
+		return nil, nil, makeFailureItem(
+			channel.FundingOutpoint,
+			lnrpc.UpdateFailure_UPDATE_FAILURE_UNKNOWN,
+			"could not add edge",
+		)
+	}
+
+	return info, edge, nil
+}
+
+// createEdge recreates an edge and policy from an open channel in-memory.
+func (r *Manager) createEdge(channel *channeldb.OpenChannel,
+	timestamp time.Time) (*models.ChannelEdgeInfo,
+	*models.ChannelEdgePolicy, error) {
+
+	nodeKey1Bytes := r.SelfPub.SerializeCompressed()
+	nodeKey2Bytes := channel.IdentityPub.SerializeCompressed()
+	bitcoinKey1Bytes := channel.LocalChanCfg.MultiSigKey.PubKey.
+		SerializeCompressed()
+	bitcoinKey2Bytes := channel.RemoteChanCfg.MultiSigKey.PubKey.
+		SerializeCompressed()
+	channelFlags := lnwire.ChanUpdateChanFlags(0)
+
+	// Make it such that node_id_1 is the lexicographically-lesser of the
+	// two compressed keys sorted in ascending lexicographic order.
+	if bytes.Compare(nodeKey2Bytes, nodeKey1Bytes) < 0 {
+		nodeKey1Bytes, nodeKey2Bytes = nodeKey2Bytes, nodeKey1Bytes
+		bitcoinKey1Bytes, bitcoinKey2Bytes = bitcoinKey2Bytes,
+			bitcoinKey1Bytes
+		channelFlags = 1
+	}
+
+	var featureBuf bytes.Buffer
+	err := lnwire.NewRawFeatureVector().Encode(&featureBuf)
+	if err != nil {
+		return nil, nil, fmt.Errorf("unable to encode features: %w",
+			err)
+	}
+
+	info := &models.ChannelEdgeInfo{
+		ChannelID:    channel.ShortChanID().ToUint64(),
+		ChainHash:    channel.ChainHash,
+		Features:     featureBuf.Bytes(),
+		Capacity:     channel.Capacity,
+		ChannelPoint: channel.FundingOutpoint,
+	}
+
+	copy(info.NodeKey1Bytes[:], nodeKey1Bytes)
+	copy(info.NodeKey2Bytes[:], nodeKey2Bytes)
+	copy(info.BitcoinKey1Bytes[:], bitcoinKey1Bytes)
+	copy(info.BitcoinKey2Bytes[:], bitcoinKey2Bytes)
+
+	// Construct a dummy channel edge policy with default values that will
+	// be updated with the new values in the call to processChan below.
+	timeLockDelta := uint16(r.DefaultRoutingPolicy.TimeLockDelta)
+	edge := &models.ChannelEdgePolicy{
+		ChannelID:                 channel.ShortChanID().ToUint64(),
+		LastUpdate:                timestamp,
+		TimeLockDelta:             timeLockDelta,
+		ChannelFlags:              channelFlags,
+		MessageFlags:              lnwire.ChanUpdateRequiredMaxHtlc,
+		FeeBaseMSat:               r.DefaultRoutingPolicy.BaseFee,
+		FeeProportionalMillionths: r.DefaultRoutingPolicy.FeeRate,
+		MinHTLC:                   r.DefaultRoutingPolicy.MinHTLCOut,
+		MaxHTLC:                   r.DefaultRoutingPolicy.MaxHTLC,
+	}
+
+	copy(edge.ToNode[:], channel.IdentityPub.SerializeCompressed())
+
+	return info, edge, nil
+}
+
 // updateEdge updates the given edge with the new schema.
 func (r *Manager) updateEdge(tx kvdb.RTx, chanPoint wire.OutPoint,
 	edge *models.ChannelEdgePolicy,
 	newSchema routing.ChannelPolicy) error {
 
+	channel, err := r.FetchChannel(tx, chanPoint)
+	if err != nil {
+		return err
+	}
+
 	// Update forwarding fee scheme and required time lock delta.
 	edge.FeeBaseMSat = newSchema.BaseFee
 	edge.FeeProportionalMillionths = lnwire.MilliSatoshi(
@@ -192,7 +367,7 @@ func (r *Manager) updateEdge(tx kvdb.RTx, chanPoint wire.OutPoint,
 	)
 
 	// If inbound fees are set, we update the edge with them.
-	err := fn.MapOptionZ(newSchema.InboundFee,
+	err = fn.MapOptionZ(newSchema.InboundFee,
 		func(f models.InboundFee) error {
 			inboundWireFee := f.ToWire()
 			return edge.ExtraOpaqueData.PackRecords(
@@ -206,7 +381,7 @@ func (r *Manager) updateEdge(tx kvdb.RTx, chanPoint wire.OutPoint,
 	edge.TimeLockDelta = uint16(newSchema.TimeLockDelta)
 
 	// Retrieve negotiated channel htlc amt limits.
-	amtMin, amtMax, err := r.getHtlcAmtLimits(tx, chanPoint)
+	amtMin, amtMax, err := r.getHtlcAmtLimits(channel)
 	if err != nil {
 		return err
 	}
@@ -267,14 +442,9 @@ func (r *Manager) updateEdge(tx kvdb.RTx, chanPoint wire.OutPoint,
 
 // getHtlcAmtLimits retrieves the negotiated channel min and max htlc amount
 // constraints.
-func (r *Manager) getHtlcAmtLimits(tx kvdb.RTx, chanPoint wire.OutPoint) (
+func (r *Manager) getHtlcAmtLimits(ch *channeldb.OpenChannel) (
 	lnwire.MilliSatoshi, lnwire.MilliSatoshi, error) {
 
-	ch, err := r.FetchChannel(tx, chanPoint)
-	if err != nil {
-		return 0, 0, err
-	}
-
 	// The max htlc policy field must be less than or equal to the channel
 	// capacity AND less than or equal to the max in-flight HTLC value.
 	// Since the latter is always less than or equal to the former, just

routing/localchans/manager_test.go

@@ -1,14 +1,19 @@
 package localchans
 
 import (
+	"encoding/hex"
 	"testing"
+	"time"
 
+	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/discovery"
+	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -35,6 +40,18 @@ func TestManager(t *testing.T) {
 		channelSet         []channel
 	)
 
+	sp := [33]byte{}
+	_, _ = hex.Decode(sp[:], []byte("028d7500dd4c12685d1f568b4c2b5048e85"+
+		"34b873319f3a8daa612b469132ec7f7"))
+	rp := [33]byte{}
+	_, _ = hex.Decode(rp[:], []byte("034f355bdcb7cc0af728ef3cceb9615d906"+
+		"84bb5b2ca5f859ab0f0b704075871aa"))
+	selfpub, _ := btcec.ParsePubKey(sp[:])
+	remotepub, _ := btcec.ParsePubKey(rp[:])
+	localMultisigPrivKey, _ := btcec.NewPrivateKey()
+	localMultisigKey := localMultisigPrivKey.PubKey()
+	remoteMultisigPrivKey, _ := btcec.NewPrivateKey()
+	remoteMultisigKey := remoteMultisigPrivKey.PubKey()
 	newPolicy := routing.ChannelPolicy{
 		FeeSchema: routing.FeeSchema{
 			BaseFee: 100,
@@ -131,17 +148,42 @@ func TestManager(t *testing.T) {
 		}
 
 		return &channeldb.OpenChannel{
+			FundingOutpoint: chanPointValid,
+			IdentityPub:     remotepub,
 			LocalChanCfg: channeldb.ChannelConfig{
 				ChannelStateBounds: bounds,
+				MultiSigKey: keychain.KeyDescriptor{
+					PubKey: localMultisigKey,
+				},
+			},
+			RemoteChanCfg: channeldb.ChannelConfig{
+				ChannelStateBounds: bounds,
+				MultiSigKey: keychain.KeyDescriptor{
+					PubKey: remoteMultisigKey,
+				},
 			},
 		}, nil
 	}
 
+	addEdge := func(edge *models.ChannelEdgeInfo) error {
+		return nil
+	}
+
 	manager := Manager{
 		UpdateForwardingPolicies:  updateForwardingPolicies,
 		PropagateChanPolicyUpdate: propagateChanPolicyUpdate,
 		ForAllOutgoingChannels:    forAllOutgoingChannels,
 		FetchChannel:              fetchChannel,
+		SelfPub:                   selfpub,
+		DefaultRoutingPolicy: models.ForwardingPolicy{
+			MinHTLCOut:    minHTLC,
+			MaxHTLC:       maxPendingAmount,
+			BaseFee:       lnwire.MilliSatoshi(1000),
+			FeeRate:       lnwire.MilliSatoshi(0),
+			InboundFee:    models.InboundFee{},
+			TimeLockDelta: 80,
+		},
+		AddEdge: addEdge,
 	}
 
 	// Policy with no max htlc value.
@@ -156,6 +198,7 @@ func TestManager(t *testing.T) {
 		newPolicy              routing.ChannelPolicy
 		channelSet             []channel
 		specifiedChanPoints    []wire.OutPoint
+		createMissingEdge      bool
 		expectedNumUpdates     int
 		expectedUpdateFailures []lnrpc.UpdateFailure
 		expectErr              error
@@ -173,6 +216,7 @@ func TestManager(t *testing.T) {
 				},
 			},
 			specifiedChanPoints:    []wire.OutPoint{chanPointValid},
+			createMissingEdge:      false,
 			expectedNumUpdates:     1,
 			expectedUpdateFailures: []lnrpc.UpdateFailure{},
 			expectErr:              nil,
@@ -190,6 +234,7 @@ func TestManager(t *testing.T) {
 				},
 			},
 			specifiedChanPoints:    []wire.OutPoint{},
+			createMissingEdge:      false,
 			expectedNumUpdates:     1,
 			expectedUpdateFailures: []lnrpc.UpdateFailure{},
 			expectErr:              nil,
@@ -207,6 +252,7 @@ func TestManager(t *testing.T) {
 				},
 			},
 			specifiedChanPoints: []wire.OutPoint{chanPointMissing},
+			createMissingEdge:   false,
 			expectedNumUpdates:  0,
 			expectedUpdateFailures: []lnrpc.UpdateFailure{
 				lnrpc.UpdateFailure_UPDATE_FAILURE_NOT_FOUND,
@@ -228,10 +274,39 @@ func TestManager(t *testing.T) {
 				},
 			},
 			specifiedChanPoints:    []wire.OutPoint{chanPointValid},
+			createMissingEdge:      false,
 			expectedNumUpdates:     1,
 			expectedUpdateFailures: []lnrpc.UpdateFailure{},
 			expectErr:              nil,
 		},
+		{
+			// Here, the edge is missing, causing the edge to be
+			// recreated.
+			name:                   "missing edge recreated",
+			currentPolicy:          models.ChannelEdgePolicy{},
+			newPolicy:              newPolicy,
+			channelSet:             []channel{},
+			specifiedChanPoints:    []wire.OutPoint{chanPointValid},
+			createMissingEdge:      true,
+			expectedNumUpdates:     1,
+			expectedUpdateFailures: []lnrpc.UpdateFailure{},
+			expectErr:              nil,
+		},
+		{
+			// Here, the edge is missing, but the edge will not be
+			// recreated, because createMissingEdge is false.
+			name:                "missing edge ignored",
+			currentPolicy:       models.ChannelEdgePolicy{},
+			newPolicy:           newPolicy,
+			channelSet:          []channel{},
+			specifiedChanPoints: []wire.OutPoint{chanPointValid},
+			createMissingEdge:   false,
+			expectedNumUpdates:  0,
+			expectedUpdateFailures: []lnrpc.UpdateFailure{
+				lnrpc.UpdateFailure_UPDATE_FAILURE_UNKNOWN,
+			},
+			expectErr: nil,
+		},
 	}
 
 	for _, test := range tests {
@@ -242,6 +317,7 @@ func TestManager(t *testing.T) {
 			expectedNumUpdates = test.expectedNumUpdates
 
 			failedUpdates, err := manager.UpdatePolicy(test.newPolicy,
+				test.createMissingEdge,
 				test.specifiedChanPoints...)
 
 			if len(failedUpdates) != len(test.expectedUpdateFailures) {
@@ -258,3 +334,179 @@ func TestManager(t *testing.T) {
 		})
 	}
 }
+
+// Tests creating a new edge in the manager where the local pubkey is the
+// lexicographically lesser or the two.
+func TestCreateEdgeLower(t *testing.T) {
+	sp := [33]byte{}
+	_, _ = hex.Decode(sp[:], []byte("028d7500dd4c12685d1f568b4c2b5048e85"+
+		"34b873319f3a8daa612b469132ec7f7"))
+	rp := [33]byte{}
+	_, _ = hex.Decode(rp[:], []byte("034f355bdcb7cc0af728ef3cceb9615d906"+
+		"84bb5b2ca5f859ab0f0b704075871aa"))
+	selfpub, _ := btcec.ParsePubKey(sp[:])
+	remotepub, _ := btcec.ParsePubKey(rp[:])
+	localMultisigPrivKey, _ := btcec.NewPrivateKey()
+	localMultisigKey := localMultisigPrivKey.PubKey()
+	remoteMultisigPrivKey, _ := btcec.NewPrivateKey()
+	remoteMultisigKey := remoteMultisigPrivKey.PubKey()
+	timestamp := time.Now()
+	defaultPolicy := models.ForwardingPolicy{
+		MinHTLCOut: 1,
+		MaxHTLC:    2,
+		BaseFee:    3,
+		FeeRate:    4,
+		InboundFee: models.InboundFee{
+			Base: 5,
+			Rate: 6,
+		},
+		TimeLockDelta: 7,
+	}
+
+	channel := &channeldb.OpenChannel{
+		IdentityPub: remotepub,
+		LocalChanCfg: channeldb.ChannelConfig{
+			MultiSigKey: keychain.KeyDescriptor{
+				PubKey: localMultisigKey,
+			},
+		},
+		RemoteChanCfg: channeldb.ChannelConfig{
+			MultiSigKey: keychain.KeyDescriptor{
+				PubKey: remoteMultisigKey,
+			},
+		},
+		ShortChannelID: lnwire.NewShortChanIDFromInt(8),
+		ChainHash:      *chaincfg.RegressionNetParams.GenesisHash,
+		Capacity:       9,
+		FundingOutpoint: wire.OutPoint{
+			Hash:  chainhash.Hash([32]byte{}),
+			Index: 0,
+		},
+	}
+	expectedInfo := &models.ChannelEdgeInfo{
+		ChannelID:     8,
+		ChainHash:     channel.ChainHash,
+		Features:      []byte{0, 0},
+		Capacity:      9,
+		ChannelPoint:  channel.FundingOutpoint,
+		NodeKey1Bytes: sp,
+		NodeKey2Bytes: rp,
+		BitcoinKey1Bytes: [33]byte(
+			localMultisigKey.SerializeCompressed()),
+		BitcoinKey2Bytes: [33]byte(
+			remoteMultisigKey.SerializeCompressed()),
+		AuthProof:       nil,
+		ExtraOpaqueData: nil,
+	}
+	expectedEdge := &models.ChannelEdgePolicy{
+		ChannelID:                 8,
+		LastUpdate:                timestamp,
+		TimeLockDelta:             7,
+		ChannelFlags:              0,
+		MessageFlags:              lnwire.ChanUpdateRequiredMaxHtlc,
+		FeeBaseMSat:               3,
+		FeeProportionalMillionths: 4,
+		MinHTLC:                   1,
+		MaxHTLC:                   2,
+		SigBytes:                  nil,
+		ToNode:                    rp,
+		ExtraOpaqueData:           nil,
+	}
+	manager := Manager{
+		SelfPub:              selfpub,
+		DefaultRoutingPolicy: defaultPolicy,
+	}
+
+	info, edge, err := manager.createEdge(channel, timestamp)
+	require.NoError(t, err)
+	require.Equal(t, expectedInfo, info)
+	require.Equal(t, expectedEdge, edge)
+}
+
+// Tests creating a new edge in the manager where the local pubkey is the
+// lexicographically higher or the two.
+func TestCreateEdgeHigher(t *testing.T) {
+	sp := [33]byte{}
+	_, _ = hex.Decode(sp[:], []byte("034f355bdcb7cc0af728ef3cceb9615d906"+
+		"84bb5b2ca5f859ab0f0b704075871aa"))
+	rp := [33]byte{}
+	_, _ = hex.Decode(rp[:], []byte("028d7500dd4c12685d1f568b4c2b5048e85"+
+		"34b873319f3a8daa612b469132ec7f7"))
+	selfpub, _ := btcec.ParsePubKey(sp[:])
+	remotepub, _ := btcec.ParsePubKey(rp[:])
+	localMultisigPrivKey, _ := btcec.NewPrivateKey()
+	localMultisigKey := localMultisigPrivKey.PubKey()
+	remoteMultisigPrivKey, _ := btcec.NewPrivateKey()
+	remoteMultisigKey := remoteMultisigPrivKey.PubKey()
+	timestamp := time.Now()
+	defaultPolicy := models.ForwardingPolicy{
+		MinHTLCOut: 1,
+		MaxHTLC:    2,
+		BaseFee:    3,
+		FeeRate:    4,
+		InboundFee: models.InboundFee{
+			Base: 5,
+			Rate: 6,
+		},
+		TimeLockDelta: 7,
+	}
+
+	channel := &channeldb.OpenChannel{
+		IdentityPub: remotepub,
+		LocalChanCfg: channeldb.ChannelConfig{
+			MultiSigKey: keychain.KeyDescriptor{
+				PubKey: localMultisigKey,
+			},
+		},
+		RemoteChanCfg: channeldb.ChannelConfig{
+			MultiSigKey: keychain.KeyDescriptor{
+				PubKey: remoteMultisigKey,
+			},
+		},
+		ShortChannelID: lnwire.NewShortChanIDFromInt(8),
+		ChainHash:      *chaincfg.RegressionNetParams.GenesisHash,
+		Capacity:       9,
+		FundingOutpoint: wire.OutPoint{
+			Hash:  chainhash.Hash([32]byte{}),
+			Index: 0,
+		},
+	}
+	expectedInfo := &models.ChannelEdgeInfo{
+		ChannelID:     8,
+		ChainHash:     channel.ChainHash,
+		Features:      []byte{0, 0},
+		Capacity:      9,
+		ChannelPoint:  channel.FundingOutpoint,
+		NodeKey1Bytes: rp,
+		NodeKey2Bytes: sp,
+		BitcoinKey1Bytes: [33]byte(
+			remoteMultisigKey.SerializeCompressed()),
+		BitcoinKey2Bytes: [33]byte(
+			localMultisigKey.SerializeCompressed()),
+		AuthProof:       nil,
+		ExtraOpaqueData: nil,
+	}
+	expectedEdge := &models.ChannelEdgePolicy{
+		ChannelID:                 8,
+		LastUpdate:                timestamp,
+		TimeLockDelta:             7,
+		ChannelFlags:              1,
+		MessageFlags:              lnwire.ChanUpdateRequiredMaxHtlc,
+		FeeBaseMSat:               3,
+		FeeProportionalMillionths: 4,
+		MinHTLC:                   1,
+		MaxHTLC:                   2,
+		SigBytes:                  nil,
+		ToNode:                    rp,
+		ExtraOpaqueData:           nil,
+	}
+	manager := Manager{
+		SelfPub:              selfpub,
+		DefaultRoutingPolicy: defaultPolicy,
+	}
+
+	info, edge, err := manager.createEdge(channel, timestamp)
+	require.NoError(t, err)
+	require.Equal(t, expectedInfo, info)
+	require.Equal(t, expectedEdge, edge)
+}

rpcserver.go

@@ -7770,7 +7770,7 @@ func (r *rpcServer) UpdateChannelPolicy(ctx context.Context,
 	// With the scope resolved, we'll now send this to the local channel
 	// manager so it can propagate the new policy for our target channel(s).
 	failedUpdates, err := r.server.localChanMgr.UpdatePolicy(chanPolicy,
-		targetChans...)
+		req.CreateMissingEdge, targetChans...)
 	if err != nil {
 		return nil, err
 	}

server.go

@@ -1118,12 +1118,31 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 		ScidCloser:              scidCloserMan,
 	}, nodeKeyDesc)
 
+	selfVertex := route.Vertex(nodeKeyDesc.PubKey.SerializeCompressed())
 	//nolint:lll
 	s.localChanMgr = &localchans.Manager{
-		ForAllOutgoingChannels:    s.graphBuilder.ForAllOutgoingChannels,
+		SelfPub:              nodeKeyDesc.PubKey,
+		DefaultRoutingPolicy: cc.RoutingPolicy,
+		ForAllOutgoingChannels: func(cb func(kvdb.RTx,
+			*models.ChannelEdgeInfo, *models.ChannelEdgePolicy) error) error {
+
+			return s.graphDB.ForEachNodeChannel(selfVertex,
+				func(tx kvdb.RTx, c *models.ChannelEdgeInfo,
+					e *models.ChannelEdgePolicy,
+					_ *models.ChannelEdgePolicy) error {
+
+					// NOTE: The invoked callback here may
+					// receive a nil channel policy.
+					return cb(tx, c, e)
+				},
+			)
+		},
 		PropagateChanPolicyUpdate: s.authGossiper.PropagateChanPolicyUpdate,
 		UpdateForwardingPolicies:  s.htlcSwitch.UpdateForwardingPolicies,
 		FetchChannel:              s.chanStateDB.FetchChannel,
+		AddEdge: func(edge *models.ChannelEdgeInfo) error {
+			return s.graphBuilder.AddEdge(edge)
+		},
 	}
 
 	utxnStore, err := contractcourt.NewNurseryStore(