From 4b4d34fcceaf3a1e6d0d858e61624f33e148f6fd Mon Sep 17 00:00:00 2001
From: Carsten Otto <git@c-otto.de>
Date: Mon, 17 May 2021 11:13:59 +0100
Subject: [PATCH] htlcswitch: change errors to warnings

for issues caused by bogus incoming HTLC data
---
 htlcswitch/link.go                   | 14 +++++++-------
 lntest/itest/log_error_whitelist.txt |  2 --
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/htlcswitch/link.go b/htlcswitch/link.go
index 8d8423eb..2718ae63 100644
--- a/htlcswitch/link.go
+++ b/htlcswitch/link.go
@@ -2217,7 +2217,7 @@ func (l *channelLink) CheckHtlcForward(payHash [32]byte,
 	// any case, we'll cancel this HTLC.
 	actualFee := incomingHtlcAmt - amtToForward
 	if incomingHtlcAmt < amtToForward || actualFee < expectedFee {
-		l.log.Errorf("outgoing htlc(%x) has insufficient fee: "+
+		l.log.Warnf("outgoing htlc(%x) has insufficient fee: "+
 			"expected %v, got %v",
 			payHash[:], int64(expectedFee), int64(actualFee))
 
@@ -2239,7 +2239,7 @@ func (l *channelLink) CheckHtlcForward(payHash [32]byte,
 	// sender messed up, or an intermediate node tampered with the HTLC.
 	timeDelta := policy.TimeLockDelta
 	if incomingTimeout < outgoingTimeout+timeDelta {
-		l.log.Errorf("incoming htlc(%x) has incorrect time-lock value: "+
+		l.log.Warnf("incoming htlc(%x) has incorrect time-lock value: "+
 			"expected at least %v block delta, got %v block delta",
 			payHash[:], timeDelta, incomingTimeout-outgoingTimeout)
 
@@ -2286,7 +2286,7 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 	// too small for the next hop. If so, then we'll cancel the HTLC
 	// directly.
 	if amt < policy.MinHTLCOut {
-		l.log.Errorf("outgoing htlc(%x) is too small: min_htlc=%v, "+
+		l.log.Warnf("outgoing htlc(%x) is too small: min_htlc=%v, "+
 			"htlc_value=%v", payHash[:], policy.MinHTLCOut,
 			amt)
 
@@ -2305,7 +2305,7 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 	// Next, ensure that the passed HTLC isn't too large. If so, we'll
 	// cancel the HTLC directly.
 	if policy.MaxHTLC != 0 && amt > policy.MaxHTLC {
-		l.log.Errorf("outgoing htlc(%x) is too large: max_htlc=%v, "+
+		l.log.Warnf("outgoing htlc(%x) is too large: max_htlc=%v, "+
 			"htlc_value=%v", payHash[:], policy.MaxHTLC, amt)
 
 		// As part of the returned error, we'll send our latest routing
@@ -2322,7 +2322,7 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 	// future, so we'll reject an HTLC if the outgoing expiration time is
 	// too close to the current height.
 	if timeout <= heightNow+l.cfg.OutgoingCltvRejectDelta {
-		l.log.Errorf("htlc(%x) has an expiry that's too soon: "+
+		l.log.Warnf("htlc(%x) has an expiry that's too soon: "+
 			"outgoing_expiry=%v, best_height=%v", payHash[:],
 			timeout, heightNow)
 		failure := l.createFailureWithUpdate(
@@ -2335,7 +2335,7 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 
 	// Check absolute max delta.
 	if timeout > l.cfg.MaxOutgoingCltvExpiry+heightNow {
-		l.log.Errorf("outgoing htlc(%x) has a time lock too far in "+
+		l.log.Warnf("outgoing htlc(%x) has a time lock too far in "+
 			"the future: got %v, but maximum is %v", payHash[:],
 			timeout-heightNow, l.cfg.MaxOutgoingCltvExpiry)
 
@@ -2344,7 +2344,7 @@ func (l *channelLink) canSendHtlc(policy ForwardingPolicy,
 
 	// Check to see if there is enough balance in this channel.
 	if amt > l.Bandwidth() {
-		l.log.Errorf("insufficient bandwidth to route htlc: %v is "+
+		l.log.Warnf("insufficient bandwidth to route htlc: %v is "+
 			"larger than %v", amt, l.Bandwidth())
 		failure := l.createFailureWithUpdate(
 			func(upd *lnwire.ChannelUpdate) lnwire.FailureMessage {
diff --git a/lntest/itest/log_error_whitelist.txt b/lntest/itest/log_error_whitelist.txt
index 82fe9f3b..a51376df 100644
--- a/lntest/itest/log_error_whitelist.txt
+++ b/lntest/itest/log_error_whitelist.txt
@@ -109,8 +109,6 @@
 <time> [ERR] HSWC: ChannelLink(<chan>): failing link: unable to synchronize channel states: unable to send chan sync message for ChannelPoint(<chan_point>): write tcp <ip>-><ip>: write: connection reset by peer with error: unable to resume channel, recovery required
 <time> [ERR] HSWC: ChannelLink(<chan>): failing link: unable to update commitment: link shutting down with error: internal error
 <time> [ERR] HSWC: ChannelLink(<chan>): link failed, exiting htlcManager
-<time> [ERR] HSWC: ChannelLink(<chan>): outgoing htlc(<hex>) has insufficient fee: expected 575000, got 1075
-<time> [ERR] HSWC: ChannelLink(<chan>): outgoing htlc(<hex>) is too small: min_htlc=<amt>, htlc_value=<amt>
 <time> [ERR] HSWC: ChannelLink(<chan>): unable to cancel incoming HTLC for circuit-key=(Chan ID=<chan>, HTLC ID=0): HTLC with ID 0 has already been failed
 <time> [ERR] HSWC: ChannelLink(<chan>): unable to decode onion hop iterator: TemporaryChannelFailure
 <time> [ERR] HSWC: ChannelLink(<chan>): unable to update signals