invoices: store custom records in invoice database

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"