From ff37b711c6dea62f6acb9d0aaca36417edcda820 Mon Sep 17 00:00:00 2001
From: "Johan T. Halseth" <johanth@gmail.com>
Date: Fri, 20 Sep 2019 10:55:20 +0200
Subject: [PATCH] funding: dont's send ErrorCode on wire

Since the ErrorCodes are not part of the spec, they cannot be read by
other implementations.

Instead of only sending the error code we therefore send the complete
error message. This will have the same effect at the client, as it will
just get the full error instead of the code indicating which error it
is. It will also be compatible with other impls.

Note that the GRPC error codes will change, since we don't set them
anymore.
---
 fundingmanager.go        | 29 +++++++----------------------
 lntest/itest/lnd_test.go |  5 +++--
 2 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/fundingmanager.go b/fundingmanager.go
index 855df1b8..34b0a8f1 100644
--- a/fundingmanager.go
+++ b/fundingmanager.go
@@ -26,7 +26,6 @@ import (
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing"
 	"golang.org/x/crypto/salsa20"
-	"google.golang.org/grpc"
 )
 
 const (
@@ -862,15 +861,14 @@ func (f *fundingManager) failFundingFlow(peer lnpeer.Peer, tempChanID [32]byte,
 	var msg lnwire.ErrorData
 	switch e := fundingErr.(type) {
 
-	// Let the actual error message be sent to the remote.
+	// Let the actual error message be sent to the remote for the
+	// whitelisted types.
 	case lnwallet.ReservationError:
 		msg = lnwire.ErrorData(e.Error())
-
-	// Send the status code.
 	case lnwire.ErrorCode:
-		msg = lnwire.ErrorData{byte(e)}
+		msg = lnwire.ErrorData(e.Error())
 
-	// We just send a generic error.
+	// For all other error types we just send a generic error.
 	default:
 		msg = lnwire.ErrorData("funding failed due to internal error")
 	}
@@ -2963,25 +2961,12 @@ func (f *fundingManager) handleErrorMsg(fmsg *fundingErrorMsg) {
 
 	// If we did indeed find the funding workflow, then we'll return the
 	// error back to the caller (if any), and cancel the workflow itself.
-	lnErr := lnwire.ErrorCode(protocolErr.Data[0])
-	fndgLog.Errorf("Received funding error from %x: %v",
+	fundingErr := fmt.Errorf("received funding error from %x: %v",
 		fmsg.peerKey.SerializeCompressed(), string(protocolErr.Data),
 	)
+	fndgLog.Errorf(fundingErr.Error())
 
-	// If this isn't a simple error code, then we'll display the entire
-	// thing.
-	if len(protocolErr.Data) > 1 {
-		err = grpc.Errorf(
-			lnErr.ToGrpcCode(), string(protocolErr.Data),
-		)
-	} else {
-		// Otherwise, we'll attempt to display just the error code
-		// itself.
-		err = grpc.Errorf(
-			lnErr.ToGrpcCode(), lnErr.String(),
-		)
-	}
-	resCtx.err <- err
+	resCtx.err <- fundingErr
 }
 
 // pruneZombieReservations loops through all pending reservations and fails the
diff --git a/lntest/itest/lnd_test.go b/lntest/itest/lnd_test.go
index fbc0ea1e..e0760423 100644
--- a/lntest/itest/lnd_test.go
+++ b/lntest/itest/lnd_test.go
@@ -42,7 +42,6 @@ import (
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing"
 	"golang.org/x/net/context"
-	"google.golang.org/grpc"
 )
 
 var (
@@ -6160,7 +6159,9 @@ func testMaxPendingChannels(net *lntest.NetworkHarness, t *harnessTest) {
 
 	if err == nil {
 		t.Fatalf("error wasn't received")
-	} else if grpc.Code(err) != lnwire.ErrMaxPendingChannels.ToGrpcCode() {
+	} else if !strings.Contains(
+		err.Error(), lnwire.ErrMaxPendingChannels.Error(),
+	) {
 		t.Fatalf("not expected error was received: %v", err)
 	}