GUACAMOLE-1048: Leverage exception conversion provided by GuacamoleStatus for "error" instruction handling.

guacamole-common/src/main/java/org/apache/guacamole/GuacamoleServerErrorInstructionException.java

@@ -1,55 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.apache.guacamole;
-
-import org.apache.guacamole.protocol.GuacamoleStatus;
-
-/**
- * The exception thrown when the Guacamole server explicitly sends an error
- * instruction to the client. The error message and status code reflect the arguments
- * of the error instruction as determined by the server.
- */
-public class GuacamoleServerErrorInstructionException extends GuacamoleServerException {
-    /**
-     * The Guacamole protocol status code, as determined by the server;
-     */
-    private final GuacamoleStatus status;
-
-    /**
-     * Creates a new GuacamoleServerErrorInstructionException with the given
-     * message and status.
-     *
-     * @param message
-     *     A human readable description of the exception that occurred.
-     *
-     * @param status
-     *     The status code, as determined by the server from which the
-     *     instruction originated.
-     */
-    public GuacamoleServerErrorInstructionException(String message, GuacamoleStatus status) {
-        super(message);
-        this.status = status;
-    }
-
-    @Override
-    public GuacamoleStatus getStatus() {
-        return status;
-    }
-}

guacamole-common/src/main/java/org/apache/guacamole/protocol/ConfiguredGuacamoleSocket.java

@@ -21,12 +21,13 @@ package org.apache.guacamole.protocol;
 
 import java.util.List;
 import org.apache.guacamole.GuacamoleException;
-import org.apache.guacamole.GuacamoleServerErrorInstructionException;
 import org.apache.guacamole.GuacamoleServerException;
 import org.apache.guacamole.io.GuacamoleReader;
 import org.apache.guacamole.io.GuacamoleWriter;
 import org.apache.guacamole.net.DelegatingGuacamoleSocket;
 import org.apache.guacamole.net.GuacamoleSocket;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * A GuacamoleSocket which pre-configures the connection based on a given
@@ -40,6 +41,12 @@ import org.apache.guacamole.net.GuacamoleSocket;
  */
 public class ConfiguredGuacamoleSocket extends DelegatingGuacamoleSocket {
 
+    /**
+     * Logger for this class.
+     */
+    private static final Logger logger =
+            LoggerFactory.getLogger(ConfiguredGuacamoleSocket.class);
+
     /**
      * The configuration to use when performing the Guacamole protocol
      * handshake.
@@ -62,23 +69,59 @@ public class ConfiguredGuacamoleSocket extends DelegatingGuacamoleSocket {
             GuacamoleProtocolVersion.VERSION_1_0_0;
 
     /**
-     * Parses the arguments for the Guacamole "error" server instruction and returns
-     * the corresponding exception.
-     * @param args The arguments as provided by the server instruction.
-     * @return An instance of {@link GuacamoleServerErrorInstructionException} configured
-     *         with the server-provided arguments, or a generic {@link GuacamoleServerException} if
-     *         the specified arguments are invalid.
+     * Parses the given "error" instruction, throwing a GuacamoleException that
+     * corresponds to its status code and message.
+     *
+     * @param instruction
+     *     The "error" instruction to parse.
+     *
+     * @throws GuacamoleException
+     *     A GuacamoleException that corresponds to the status code and message
+     *     present within the given "error" instruction.
      */
-    private static GuacamoleServerException parseServerErrorInstructionArgs(List<String> args) {
-        try {
-            if (args.size() >= 2) {
-                int code = Integer.parseInt(args.get(1));
-                GuacamoleStatus status = GuacamoleStatus.fromGuacamoleStatusCode(code);
-                return new GuacamoleServerErrorInstructionException(args.get(0), status);
-            }
-        } catch (NumberFormatException ignored) {}
+    private static void handleReceivedError(GuacamoleInstruction instruction)
+            throws GuacamoleException {
+
+        // Provide reasonable default error message for invalid "error"
+        // instructions that fail to provide one
+        String message = "Internal error within guacd / protocol handling.";
+
+        // Consider all error instructions without a corresponding status code
+        // to be server errors
+        GuacamoleStatus status = GuacamoleStatus.SERVER_ERROR;
+
+        // Parse human-readable message from "error" instruction, warning if no
+        // message was given
+        List<String> args = instruction.getArgs();
+        if (args.size() >= 1)
+            message = args.get(0);
+        else
+            logger.debug("Received \"error\" instruction with no corresponding message.");
+
+        // Parse the status code from the received error instruction, warning
+        // if the status code is missing or invalid
+        if (args.size() >= 2) {
+            try {
+                
+                // Translate numeric status code into a GuacamoleStatus
+                int statusCode = Integer.parseInt(args.get(1));
+                GuacamoleStatus parsedStatus = GuacamoleStatus.fromGuacamoleStatusCode(statusCode);
+                if (parsedStatus != null)
+                    status = parsedStatus;
+                else
+                    logger.debug("Received \"error\" instruction with unknown/invalid status code: {}", statusCode);
+
+            }
+            catch (NumberFormatException e) {
+                logger.debug("Received \"error\" instruction with non-numeric status code.", e);
+            }
+        }
+        else
+            logger.debug("Received \"error\" instruction without status code.");
+
+        // Convert parsed status code and message to a GuacamoleException
+        throw status.toException(message);
 
-        return new GuacamoleServerException("Invalid error instruction arguments received: " + args);
     }
 
     /**
@@ -107,7 +150,7 @@ public class ConfiguredGuacamoleSocket extends DelegatingGuacamoleSocket {
         if ("disconnect".equals(instruction.getOpcode()))
             throw new GuacamoleServerException("Server disconnected while waiting for \"" + opcode + "\".");
         if ("error".equals(instruction.getOpcode()))
-            throw parseServerErrorInstructionArgs(instruction.getArgs());
+            handleReceivedError(instruction);
 
         // Ensure instruction has expected opcode
         if (!instruction.getOpcode().equals(opcode))