From 8f25a73332400e73385bf48b7f7a78fd85cda680 Mon Sep 17 00:00:00 2001
From: Olaoluwa Osuntokun <laolu32@gmail.com>
Date: Mon, 21 Aug 2017 23:30:01 -0700
Subject: [PATCH] funding: abandon usage of Code field in lnwire.Error

This commit modifies the generation and parsing of errors to abandon
usage of the Code field, and instead use the first byte of the Data
field to store the error codes that we currently use. With this change,
we ensure that our error messages properly match BOLT-0002.
---
 fundingmanager.go | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/fundingmanager.go b/fundingmanager.go
index 6e5c45ec..d2f53776 100644
--- a/fundingmanager.go
+++ b/fundingmanager.go
@@ -635,8 +635,7 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 	if len(f.activeReservations[peerIDKey]) >= cfg.MaxPendingChannels {
 		errMsg := &lnwire.Error{
 			ChanID: fmsg.msg.PendingChannelID,
-			Code:   lnwire.ErrMaxPendingChannels,
-			Data:   []byte("Number of pending channels exceed maximum"),
+			Data:   lnwire.ErrorData{byte(lnwire.ErrMaxPendingChannels)},
 		}
 		if err := f.cfg.SendToPeer(fmsg.peerAddress.IdentityKey, errMsg); err != nil {
 			fndgLog.Errorf("unable to send max pending channels "+
@@ -658,8 +657,7 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 	if !isSynced {
 		errMsg := &lnwire.Error{
 			ChanID: fmsg.msg.PendingChannelID,
-			Code:   lnwire.ErrSynchronizingChain,
-			Data:   []byte("Synchronizing blockchain"),
+			Data:   lnwire.ErrorData{byte(lnwire.ErrSynchronizingChain)},
 		}
 		if err := f.cfg.SendToPeer(fmsg.peerAddress.IdentityKey, errMsg); err != nil {
 			fndgLog.Errorf("unable to send error message to peer %v", err)
@@ -673,7 +671,7 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 	if msg.FundingAmount > maxFundingAmount {
 		errMsg := &lnwire.Error{
 			ChanID: fmsg.msg.PendingChannelID,
-			Data:   []byte("channel too large"),
+			Data:   lnwire.ErrorData{byte(lnwire.ErrChanTooLarge)},
 		}
 		err := f.cfg.SendToPeer(fmsg.peerAddress.IdentityKey, errMsg)
 		if err != nil {
@@ -1892,7 +1890,8 @@ func (f *fundingManager) processFundingError(err *lnwire.Error,
 func (f *fundingManager) handleErrorMsg(fmsg *fundingErrorMsg) {
 	e := fmsg.err
 
-	switch e.Code {
+	lnErr := lnwire.ErrorCode(e.Data[0])
+	switch lnErr {
 	case lnwire.ErrChanTooLarge:
 		fallthrough
 	case lnwire.ErrMaxPendingChannels:
@@ -1908,16 +1907,14 @@ func (f *fundingManager) handleErrorMsg(fmsg *fundingErrorMsg) {
 		}
 
 		fndgLog.Errorf("Received funding error from %x: %v",
-			peerKey.SerializeCompressed(), newLogClosure(func() string {
-				return spew.Sdump(e)
-			}),
+			peerKey.SerializeCompressed(), lnErr,
 		)
 
-		ctx.err <- grpc.Errorf(e.Code.ToGrpcCode(), string(e.Data))
+		ctx.err <- grpc.Errorf(lnErr.ToGrpcCode(), lnErr.String())
 		return
 
 	default:
-		fndgLog.Warnf("unknown funding error (%v:%v)", e.Code, e.Data)
+		fndgLog.Warnf("unknown funding error: %v", spew.Sdump(e.Data))
 	}
 }