invoices: store custom records in invoice database

channeldb/invoice_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
+	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
 )
@@ -209,13 +210,15 @@ func TestInvoiceCancelSingleHtlc(t *testing.T) {
 
 	// Accept an htlc on this invoice.
 	key := CircuitKey{ChanID: lnwire.NewShortChanIDFromInt(1), HtlcID: 4}
+	htlc := HtlcAcceptDesc{
+		Amt:           500,
+		CustomRecords: make(hop.CustomRecordSet),
+	}
 	invoice, err := db.UpdateInvoice(paymentHash,
 		func(invoice *Invoice) (*InvoiceUpdateDesc, error) {
 			return &InvoiceUpdateDesc{
 				AddHtlcs: map[CircuitKey]*HtlcAcceptDesc{
-					key: {
-						Amt: 500,
-					},
+					key: &htlc,
 				},
 			}, nil
 		})
@@ -432,10 +435,11 @@ func TestDuplicateSettleInvoice(t *testing.T) {
 	invoice.SettleDate = dbInvoice.SettleDate
 	invoice.Htlcs = map[CircuitKey]*InvoiceHTLC{
 		{}: {
-			Amt:         amt,
-			AcceptTime:  time.Unix(1, 0),
-			ResolveTime: time.Unix(1, 0),
-			State:       HtlcStateSettled,
+			Amt:           amt,
+			AcceptTime:    time.Unix(1, 0),
+			ResolveTime:   time.Unix(1, 0),
+			State:         HtlcStateSettled,
+			CustomRecords: make(hop.CustomRecordSet),
 		},
 	}
 
@@ -747,6 +751,8 @@ func getUpdateInvoice(amt lnwire.MilliSatoshi) InvoiceUpdateCallback {
 			return nil, ErrInvoiceAlreadySettled
 		}
 
+		noRecords := make(hop.CustomRecordSet)
+
 		update := &InvoiceUpdateDesc{
 			State: &InvoiceStateUpdateDesc{
 				Preimage: invoice.Terms.PaymentPreimage,
@@ -754,7 +760,8 @@ func getUpdateInvoice(amt lnwire.MilliSatoshi) InvoiceUpdateCallback {
 			},
 			AddHtlcs: map[CircuitKey]*HtlcAcceptDesc{
 				{}: {
-					Amt: amt,
+					Amt:           amt,
+					CustomRecords: noRecords,
 				},
 			},
 		}
@@ -762,3 +769,64 @@ func getUpdateInvoice(amt lnwire.MilliSatoshi) InvoiceUpdateCallback {
 		return update, nil
 	}
 }
+
+// TestCustomRecords tests that custom records are properly recorded in the
+// invoice database.
+func TestCustomRecords(t *testing.T) {
+	t.Parallel()
+
+	db, cleanUp, err := makeTestDB()
+	defer cleanUp()
+	if err != nil {
+		t.Fatalf("unable to make test db: %v", err)
+	}
+
+	testInvoice := &Invoice{
+		Htlcs: map[CircuitKey]*InvoiceHTLC{},
+	}
+	testInvoice.Terms.Value = lnwire.NewMSatFromSatoshis(10000)
+	testInvoice.Terms.Features = emptyFeatures
+
+	var paymentHash lntypes.Hash
+	if _, err := db.AddInvoice(testInvoice, paymentHash); err != nil {
+		t.Fatalf("unable to find invoice: %v", err)
+	}
+
+	// Accept an htlc with custom records on this invoice.
+	key := CircuitKey{ChanID: lnwire.NewShortChanIDFromInt(1), HtlcID: 4}
+
+	records := hop.CustomRecordSet{
+		100000: []byte{},
+		100001: []byte{1, 2},
+	}
+
+	_, err = db.UpdateInvoice(paymentHash,
+		func(invoice *Invoice) (*InvoiceUpdateDesc, error) {
+			return &InvoiceUpdateDesc{
+				AddHtlcs: map[CircuitKey]*HtlcAcceptDesc{
+					key: {
+						Amt:           500,
+						CustomRecords: records,
+					},
+				},
+			}, nil
+		},
+	)
+	if err != nil {
+		t.Fatalf("unable to add invoice htlc: %v", err)
+	}
+
+	// Retrieve the invoice from that database and verify that the custom
+	// records are present.
+	dbInvoice, err := db.LookupInvoice(paymentHash)
+	if err != nil {
+		t.Fatalf("unable to lookup invoice: %v", err)
+	}
+
+	if len(dbInvoice.Htlcs) != 1 {
+		t.Fatalf("expected the htlc to be added")
+	}
+	if !reflect.DeepEqual(records, dbInvoice.Htlcs[key].CustomRecords) {
+		t.Fatalf("invalid custom records")
+	}
+}

channeldb/invoices.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/coreos/bbolt"
+	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/tlv"
@@ -308,6 +309,10 @@ type InvoiceHTLC struct {
 	// canceled htlc isn't just removed from the invoice htlcs map, because
 	// we need AcceptHeight to properly cancel the htlc back.
 	State HtlcState
+
+	// CustomRecords contains the custom key/value pairs that accompanied
+	// the htlc.
+	CustomRecords hop.CustomRecordSet
 }
 
 // HtlcAcceptDesc describes the details of a newly accepted htlc.
@@ -320,6 +325,10 @@ type HtlcAcceptDesc struct {
 
 	// Expiry is the expiry height of this htlc.
 	Expiry uint32
+
+	// CustomRecords contains the custom key/value pairs that accompanied
+	// the htlc.
+	CustomRecords hop.CustomRecordSet
 }
 
 // InvoiceUpdateDesc describes the changes that should be applied to the
@@ -1013,7 +1022,8 @@ func serializeHtlcs(w io.Writer, htlcs map[CircuitKey]*InvoiceHTLC) error {
 		resolveTime := uint64(htlc.ResolveTime.UnixNano())
 		state := uint8(htlc.State)
 
-		tlvStream, err := tlv.NewStream(
+		var records []tlv.Record
+		records = append(records,
 			tlv.MakePrimitiveRecord(chanIDType, &chanID),
 			tlv.MakePrimitiveRecord(htlcIDType, &key.HtlcID),
 			tlv.MakePrimitiveRecord(amtType, &amt),
@@ -1025,6 +1035,16 @@ func serializeHtlcs(w io.Writer, htlcs map[CircuitKey]*InvoiceHTLC) error {
 			tlv.MakePrimitiveRecord(expiryHeightType, &htlc.Expiry),
 			tlv.MakePrimitiveRecord(htlcStateType, &state),
 		)
+
+		// Convert the custom records to tlv.Record types that are ready
+		// for serialization.
+		customRecords := tlv.MapToRecords(htlc.CustomRecords)
+
+		// Append the custom records. Their ids are in the experimental
+		// range and sorted, so there is no need to sort again.
+		records = append(records, customRecords...)
+
+		tlvStream, err := tlv.NewStream(records...)
 		if err != nil {
 			return err
 		}
@@ -1191,7 +1211,8 @@ func deserializeHtlcs(r io.Reader) (map[CircuitKey]*InvoiceHTLC, error) {
 			return nil, err
 		}
 
-		if err := tlvStream.Decode(htlcReader); err != nil {
+		parsedTypes, err := tlvStream.DecodeWithParsedTypes(htlcReader)
+		if err != nil {
 			return nil, err
 		}
 
@@ -1201,6 +1222,10 @@ func deserializeHtlcs(r io.Reader) (map[CircuitKey]*InvoiceHTLC, error) {
 		htlc.State = HtlcState(state)
 		htlc.Amt = lnwire.MilliSatoshi(amt)
 
+		// Reconstruct the custom records fields from the parsed types
+		// map return from the tlv parser.
+		htlc.CustomRecords = hop.NewCustomRecords(parsedTypes)
+
 		htlcs[key] = &htlc
 	}
 
@@ -1290,12 +1315,20 @@ func (d *DB) updateInvoice(hash lntypes.Hash, invoices, settleIndex *bbolt.Bucke
 		if _, exists := invoice.Htlcs[key]; exists {
 			return nil, fmt.Errorf("duplicate add of htlc %v", key)
 		}
+
+		// Force caller to supply htlc without custom records in a
+		// consistent way.
+		if htlcUpdate.CustomRecords == nil {
+			return nil, errors.New("nil custom records map")
+		}
+
 		htlc := &InvoiceHTLC{
-			Amt:          htlcUpdate.Amt,
-			Expiry:       htlcUpdate.Expiry,
-			AcceptHeight: uint32(htlcUpdate.AcceptHeight),
-			AcceptTime:   now,
-			State:        HtlcStateAccepted,
+			Amt:           htlcUpdate.Amt,
+			Expiry:        htlcUpdate.Expiry,
+			AcceptHeight:  uint32(htlcUpdate.AcceptHeight),
+			AcceptTime:    now,
+			State:         HtlcStateAccepted,
+			CustomRecords: htlcUpdate.CustomRecords,
 		}
 
 		invoice.Htlcs[key] = htlc

invoices/interface.go

@@ -1,6 +1,9 @@
 package invoices
 
-import "github.com/lightningnetwork/lnd/record"
+import (
+	"github.com/lightningnetwork/lnd/htlcswitch/hop"
+	"github.com/lightningnetwork/lnd/record"
+)
 
 // Payload abstracts access to any additional fields provided in the final hop's
 // TLV onion payload.
@@ -8,4 +11,8 @@ type Payload interface {
 	// MultiPath returns the record corresponding the option_mpp parsed from
 	// the onion payload.
 	MultiPath() *record.MPP
+
+	// CustomRecords returns the custom tlv type records that were parsed
+	// from the payload.
+	CustomRecords() hop.CustomRecordSet
 }

invoices/invoiceregistry.go

@@ -443,6 +443,7 @@ func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 		expiry:               expiry,
 		currentHeight:        currentHeight,
 		finalCltvRejectDelta: i.finalCltvRejectDelta,
+		customRecords:        payload.CustomRecords(),
 	}
 
 	// We'll attempt to settle an invoice matching this rHash on disk (if

invoices/invoiceregistry_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/record"
@@ -669,3 +670,7 @@ type mockPayload struct {
 func (p *mockPayload) MultiPath() *record.MPP {
 	return p.mpp
 }
+
+func (p *mockPayload) CustomRecords() hop.CustomRecordSet {
+	return make(hop.CustomRecordSet)
+}

invoices/update.go

@@ -3,6 +3,8 @@ package invoices
 import (
 	"errors"
 
+	"github.com/lightningnetwork/lnd/htlcswitch/hop"
+
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnwire"
 )
@@ -74,6 +76,7 @@ type invoiceUpdateCtx struct {
 	expiry               uint32
 	currentHeight        int32
 	finalCltvRejectDelta int32
+	customRecords        hop.CustomRecordSet
 }
 
 // updateInvoice is a callback for DB.UpdateInvoice that contains the invoice
@@ -125,9 +128,10 @@ func updateInvoice(ctx *invoiceUpdateCtx, inv *channeldb.Invoice) (
 	// Record HTLC in the invoice database.
 	newHtlcs := map[channeldb.CircuitKey]*channeldb.HtlcAcceptDesc{
 		ctx.circuitKey: {
-			Amt:          ctx.amtPaid,
-			Expiry:       ctx.expiry,
-			AcceptHeight: ctx.currentHeight,
+			Amt:           ctx.amtPaid,
+			Expiry:        ctx.expiry,
+			AcceptHeight:  ctx.currentHeight,
+			CustomRecords: ctx.customRecords,
 		},
 	}
 

lnrpc/invoicesrpc/utils.go

@@ -75,13 +75,14 @@ func CreateRPCInvoice(invoice *channeldb.Invoice,
 		}
 
 		rpcHtlc := lnrpc.InvoiceHTLC{
-			ChanId:       key.ChanID.ToUint64(),
-			HtlcIndex:    key.HtlcID,
-			AcceptHeight: int32(htlc.AcceptHeight),
-			AcceptTime:   htlc.AcceptTime.Unix(),
-			ExpiryHeight: int32(htlc.Expiry),
-			AmtMsat:      uint64(htlc.Amt),
-			State:        state,
+			ChanId:        key.ChanID.ToUint64(),
+			HtlcIndex:     key.HtlcID,
+			AcceptHeight:  int32(htlc.AcceptHeight),
+			AcceptTime:    htlc.AcceptTime.Unix(),
+			ExpiryHeight:  int32(htlc.Expiry),
+			AmtMsat:       uint64(htlc.Amt),
+			State:         state,
+			CustomRecords: htlc.CustomRecords,
 		}
 
 		// Only report resolved times if htlc is resolved.

lnrpc/rpc.proto

@@ -2396,6 +2396,9 @@ message InvoiceHTLC {
 
     /// Current state the htlc is in.
     InvoiceHTLCState state = 8 [json_name = "state"];
+
+    /// Custom tlv records.
+    map<uint64, bytes> custom_records = 9 [json_name = "custom_records"];
 }
 
 message AddInvoiceResponse {

lnrpc/rpc.swagger.json

@@ -2819,6 +2819,14 @@
         "state": {
           "$ref": "#/definitions/lnrpcInvoiceHTLCState",
           "description": "/ Current state the htlc is in."
+        },
+        "custom_records": {
+          "type": "object",
+          "additionalProperties": {
+            "type": "string",
+            "format": "byte"
+          },
+          "description": "/ Custom tlv records."
         }
       },
       "title": "/ Details of an HTLC that paid to an invoice"