Add flush status check in SendPacket

modules/core/04-channel/keeper/packet.go

@@ -40,6 +40,10 @@ func (k Keeper) SendPacket(
 		)
 	}
 
+	if channel.FlushStatus != types.NOTINFLUSH {
+		return 0, errorsmod.Wrapf(types.ErrInvalidFlushStatus, "expected flush status to be %s during packet send, got %s", types.NOTINFLUSH, channel.FlushStatus)
+	}
+
 	if !k.scopedKeeper.AuthenticateCapability(ctx, channelCap, host.ChannelCapabilityPath(sourcePort, sourceChannel)) {
 		return 0, errorsmod.Wrapf(types.ErrChannelCapabilityNotFound, "caller does not own capability for channel, port ID (%s) channel ID (%s)", sourcePort, sourceChannel)
 	}

modules/core/04-channel/keeper/packet_test.go

@@ -217,6 +217,43 @@ func (suite *KeeperTestSuite) TestSendPacket() {
 
 			channelCap = capabilitytypes.NewCapability(5)
 		}, false},
+		{
+			"invalid flush status: FLUSHING",
+			func() {
+				suite.coordinator.Setup(path)
+				sourceChannel = path.EndpointA.ChannelID
+
+				channel := path.EndpointA.GetChannel()
+				channel.FlushStatus = types.FLUSHING
+				path.EndpointA.SetChannel(channel)
+			},
+			false,
+		},
+		{
+			"invalid flush status: FLUSHCOMPLETE",
+			func() {
+				suite.coordinator.Setup(path)
+				sourceChannel = path.EndpointA.ChannelID
+
+				channel := path.EndpointA.GetChannel()
+				channel.FlushStatus = types.FLUSHCOMPLETE
+				path.EndpointA.SetChannel(channel)
+			},
+			false,
+		},
+		{
+			"channel is in INITUPGRADE stage",
+			func() {
+				suite.coordinator.Setup(path)
+
+				path.EndpointA.ChannelConfig.ProposedUpgrade.Fields.Version = ibcmock.UpgradeVersion
+				path.EndpointB.ChannelConfig.ProposedUpgrade.Fields.Version = ibcmock.UpgradeVersion
+
+				err := path.EndpointA.ChanUpgradeInit()
+				suite.Require().NoError(err)
+			},
+			false,
+		},
 	}
 
 	for i, tc := range testCases {