From 0744019555acd46783b910991816262277957acc Mon Sep 17 00:00:00 2001
From: Kane York <rikingcoding@gmail.com>
Date: Mon, 18 Sep 2017 14:54:09 -0700
Subject: [PATCH] Handle errors in UnmarshalClientMessage

---
 socketserver/server/handlecore.go | 35 ++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/socketserver/server/handlecore.go b/socketserver/server/handlecore.go
index 1328a523..ea4847ef 100644
--- a/socketserver/server/handlecore.go
+++ b/socketserver/server/handlecore.go
@@ -249,11 +249,21 @@ func HTTPHandleRootURL(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+type fatalDecodeError string
+
+func (e fatalDecodeError) Error() string {
+	return string(e)
+}
+
+func (e fatalDecodeError) IsFatal() bool {
+	return true
+}
+
 // ErrProtocolGeneric is sent in a ErrorCommand Reply.
-var ErrProtocolGeneric error = errors.New("FFZ Socket protocol error.")
+var ErrProtocolGeneric error = fatalDecodeError("FFZ Socket protocol error.")
 
 // ErrProtocolNegativeMsgID is sent in a ErrorCommand Reply when a negative MessageID is received.
-var ErrProtocolNegativeMsgID error = errors.New("FFZ Socket protocol error: negative or zero message ID.")
+var ErrProtocolNegativeMsgID error = fatalDecodeError("FFZ Socket protocol error: negative or zero message ID.")
 
 // ErrExpectedSingleString is sent in a ErrorCommand Reply when the Arguments are of the wrong type.
 var ErrExpectedSingleString = errors.New("Error: Expected single string as arguments.")
@@ -344,7 +354,7 @@ func RunSocketConnection(conn *websocket.Conn) {
 	})
 
 	// All set up, now enter the work loop
-	go runSocketReader(conn, _errorChan, _clientChan, stoppedChan)
+	go runSocketReader(conn, &client, _errorChan, _clientChan)
 	closeReason := runSocketWriter(conn, &client, _errorChan, _clientChan, _serverMessageChan)
 
 	// Exit
@@ -376,12 +386,14 @@ func RunSocketConnection(conn *websocket.Conn) {
 	}
 }
 
-func runSocketReader(conn *websocket.Conn, errorChan chan<- error, clientChan chan<- ClientMessage, stoppedChan <-chan struct{}) {
+func runSocketReader(conn *websocket.Conn, client *ClientInfo, errorChan chan<- error, clientChan chan<- ClientMessage) {
 	var msg ClientMessage
 	var messageType int
 	var packet []byte
 	var err error
 
+	stoppedChan := client.MsgChannelIsDone
+
 	defer close(errorChan)
 	defer close(clientChan)
 
@@ -395,8 +407,15 @@ func runSocketReader(conn *websocket.Conn, errorChan chan<- error, clientChan ch
 			break
 		}
 
-		UnmarshalClientMessage(packet, messageType, &msg)
-		if msg.MessageID == 0 {
+		msg = ClientMessage{}
+		msgErr := UnmarshalClientMessage(packet, messageType, &msg)
+		if _, ok := msgErr.(interface{IsFatal() bool}); ok {
+			errorChan <- msgErr
+			continue
+		} else if msgErr != nil {
+			client.Send(msg.Reply(ErrorCommand, msgErr.Error()))
+			continue
+		} else if msg.MessageID == 0 {
 			continue
 		}
 		select {
@@ -514,11 +533,11 @@ func UnmarshalClientMessage(data []byte, _ int, v interface{}) (err error) {
 	// Message ID
 	spaceIdx = strings.IndexRune(dataStr, ' ')
 	if spaceIdx == -1 {
-		return ErrProtocolGeneric
+		return ErrProtocolGeneric // fatal error
 	}
 	messageID, err := strconv.Atoi(dataStr[:spaceIdx])
 	if messageID < -1 || messageID == 0 {
-		return ErrProtocolNegativeMsgID
+		return ErrProtocolNegativeMsgID // fatal error
 	}
 
 	out.MessageID = messageID