GUAC-906: Implement GuacamoleConnectionClosedException. Throw when read/write fails due to closure.

guacamole-common/src/main/java/org/glyptodon/guacamole/GuacamoleConnectionClosedException.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2014 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.glyptodon.guacamole;
+
+import org.glyptodon.guacamole.protocol.GuacamoleStatus;
+
+
+/**
+ * An exception which is thrown when an operation cannot be performed because
+ * its corresponding connection is closed.
+ *
+ * @author Michael Jumper
+ */
+public class GuacamoleConnectionClosedException extends GuacamoleServerException {
+
+    /**
+     * Creates a new GuacamoleConnectionClosedException with the given message
+     * and cause.
+     *
+     * @param message A human readable description of the exception that
+     *                occurred.
+     * @param cause The cause of this exception.
+     */
+    public GuacamoleConnectionClosedException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    /**
+     * Creates a new GuacamoleConnectionClosedException with the given message.
+     *
+     * @param message A human readable description of the exception that
+     *                occurred.
+     */
+    public GuacamoleConnectionClosedException(String message) {
+        super(message);
+    }
+
+    /**
+     * Creates a new GuacamoleConnectionClosedException with the given cause.
+     *
+     * @param cause The cause of this exception.
+     */
+    public GuacamoleConnectionClosedException(Throwable cause) {
+        super(cause);
+    }
+
+    @Override
+    public GuacamoleStatus getStatus() {
+        return GuacamoleStatus.SERVER_ERROR;
+    }
+
+}

guacamole-common/src/main/java/org/glyptodon/guacamole/io/ReaderGuacamoleReader.java

@@ -25,9 +25,11 @@ package org.glyptodon.guacamole.io;
 
 import java.io.IOException;
 import java.io.Reader;
+import java.net.SocketException;
 import java.net.SocketTimeoutException;
 import java.util.Deque;
 import java.util.LinkedList;
+import org.glyptodon.guacamole.GuacamoleConnectionClosedException;
 import org.glyptodon.guacamole.GuacamoleException;
 import org.glyptodon.guacamole.GuacamoleServerException;
 import org.glyptodon.guacamole.GuacamoleUpstreamTimeoutException;
@@ -182,6 +184,9 @@ public class ReaderGuacamoleReader implements GuacamoleReader {
         catch (SocketTimeoutException e) {
             throw new GuacamoleUpstreamTimeoutException("Connection to guacd timed out.", e);
         }
+        catch (SocketException e) {
+            throw new GuacamoleConnectionClosedException("Connection to guacd is closed.", e);
+        }
         catch (IOException e) {
             throw new GuacamoleServerException(e);
         }

guacamole-common/src/main/java/org/glyptodon/guacamole/io/WriterGuacamoleWriter.java

@@ -25,8 +25,12 @@ package org.glyptodon.guacamole.io;
 
 import java.io.IOException;
 import java.io.Writer;
+import java.net.SocketException;
+import java.net.SocketTimeoutException;
+import org.glyptodon.guacamole.GuacamoleConnectionClosedException;
 import org.glyptodon.guacamole.GuacamoleException;
 import org.glyptodon.guacamole.GuacamoleServerException;
+import org.glyptodon.guacamole.GuacamoleUpstreamTimeoutException;
 import org.glyptodon.guacamole.protocol.GuacamoleInstruction;
 
 /**
@@ -58,6 +62,12 @@ public class WriterGuacamoleWriter implements GuacamoleWriter {
             output.write(chunk, off, len);
             output.flush();
         }
+        catch (SocketTimeoutException e) {
+            throw new GuacamoleUpstreamTimeoutException("Connection to guacd timed out.", e);
+        }
+        catch (SocketException e) {
+            throw new GuacamoleConnectionClosedException("Connection to guacd is closed.", e);
+        }
         catch (IOException e) {
             throw new GuacamoleServerException(e);
         }

guacamole-common/src/main/java/org/glyptodon/guacamole/servlet/GuacamoleHTTPTunnelServlet.java

@@ -35,9 +35,9 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;
 import org.glyptodon.guacamole.GuacamoleClientException;
+import org.glyptodon.guacamole.GuacamoleConnectionClosedException;
 import org.glyptodon.guacamole.GuacamoleException;
 import org.glyptodon.guacamole.GuacamoleResourceNotFoundException;
-import org.glyptodon.guacamole.GuacamoleSecurityException;
 import org.glyptodon.guacamole.GuacamoleServerException;
 import org.glyptodon.guacamole.io.GuacamoleReader;
 import org.glyptodon.guacamole.io.GuacamoleWriter;
@@ -287,7 +287,7 @@ public abstract class GuacamoleHTTPTunnelServlet extends HttpServlet {
                 // data yet.
                 char[] message = reader.read();
                 if (message == null)
-                    throw new GuacamoleResourceNotFoundException("Tunnel reached end of stream.");
+                    throw new GuacamoleConnectionClosedException("Tunnel reached end of stream.");
 
                 // For all messages, until another stream is ready (we send at least one message)
                 do {
@@ -317,20 +317,28 @@ public abstract class GuacamoleHTTPTunnelServlet extends HttpServlet {
                 response.flushBuffer();
             }
 
+            // Send end-of-stream marker if connection is closed
+            catch (GuacamoleConnectionClosedException e) {
+                out.write("0.;");
+                out.flush();
+                response.flushBuffer();
+            }
+
+            catch (GuacamoleException e) {
+
+                // Detach and close
+                session.detachTunnel(tunnel);
+                tunnel.close();
+
+                throw e;
+            }
+
             // Always close output stream
             finally {
                 out.close();
             }
 
         }
-        catch (GuacamoleException e) {
-
-            // Detach and close
-            session.detachTunnel(tunnel);
-            tunnel.close();
-
-            throw e;
-        }
         catch (IOException e) {
 
             // Log typically frequent I/O error if desired
@@ -411,6 +419,9 @@ public abstract class GuacamoleHTTPTunnelServlet extends HttpServlet {
             }
 
         }
+        catch (GuacamoleConnectionClosedException e) {
+            logger.debug("Connection closed.", e);
+        }
         catch (IOException e) {
 
             // Detach and close

guacamole-common/src/main/java/org/glyptodon/guacamole/websocket/GuacamoleWebSocketTunnelEndpoint.java

@@ -38,6 +38,7 @@ import org.glyptodon.guacamole.io.GuacamoleReader;
 import org.glyptodon.guacamole.io.GuacamoleWriter;
 import org.glyptodon.guacamole.net.GuacamoleTunnel;
 import org.glyptodon.guacamole.GuacamoleClientException;
+import org.glyptodon.guacamole.GuacamoleConnectionClosedException;
 import org.glyptodon.guacamole.protocol.GuacamoleStatus;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -178,6 +179,10 @@ public abstract class GuacamoleWebSocketTunnelEndpoint extends Endpoint {
                         logger.warn("Client request rejected: {}", e.getMessage());
                         closeConnection(session, e.getStatus());
                     }
+                    catch (GuacamoleConnectionClosedException e) {
+                        logger.debug("Connection closed.", e);
+                        closeConnection(session, GuacamoleStatus.SUCCESS);
+                    }
                     catch (GuacamoleException e) {
                         logger.error("Internal server error.", e);
                         closeConnection(session, e.getStatus());
@@ -205,6 +210,9 @@ public abstract class GuacamoleWebSocketTunnelEndpoint extends Endpoint {
             // Write received message
             writer.write(message.toCharArray());
         }
+        catch (GuacamoleConnectionClosedException e) {
+            logger.debug("Connection closed.", e);
+        }
         catch (GuacamoleException e) {
             logger.debug("Tunnel write failed.", e);
         }

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/websocket/jetty8/GuacamoleWebSocketTunnelServlet.java

@@ -32,6 +32,7 @@ import org.eclipse.jetty.websocket.WebSocket;
 import org.eclipse.jetty.websocket.WebSocket.Connection;
 import org.eclipse.jetty.websocket.WebSocketServlet;
 import org.glyptodon.guacamole.GuacamoleClientException;
+import org.glyptodon.guacamole.GuacamoleConnectionClosedException;
 import org.glyptodon.guacamole.protocol.GuacamoleStatus;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -93,6 +94,9 @@ public abstract class GuacamoleWebSocketTunnelServlet extends WebSocketServlet {
                 try {
                     writer.write(string.toCharArray());
                 }
+                catch (GuacamoleConnectionClosedException e) {
+                    logger.debug("Connection closed.", e);
+                }
                 catch (GuacamoleException e) {
                     logger.debug("Tunnel write failed.", e);
                 }
@@ -148,6 +152,10 @@ public abstract class GuacamoleWebSocketTunnelServlet extends WebSocketServlet {
                                 logger.warn("Client request rejected: {}", e.getMessage());
                                 closeConnection(connection, e.getStatus());
                             }
+                            catch (GuacamoleConnectionClosedException e) {
+                                logger.debug("Connection closed.", e);
+                                closeConnection(connection, GuacamoleStatus.SUCCESS);
+                            }
                             catch (GuacamoleException e) {
                                 logger.error("Internal server error.", e);
                                 closeConnection(connection, e.getStatus());

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/websocket/jetty9/GuacamoleWebSocketTunnelListener.java

@@ -28,6 +28,7 @@ import org.eclipse.jetty.websocket.api.RemoteEndpoint;
 import org.eclipse.jetty.websocket.api.Session;
 import org.eclipse.jetty.websocket.api.WebSocketListener;
 import org.glyptodon.guacamole.GuacamoleClientException;
+import org.glyptodon.guacamole.GuacamoleConnectionClosedException;
 import org.glyptodon.guacamole.GuacamoleException;
 import org.glyptodon.guacamole.io.GuacamoleReader;
 import org.glyptodon.guacamole.io.GuacamoleWriter;
@@ -164,6 +165,10 @@ public abstract class GuacamoleWebSocketTunnelListener implements WebSocketListe
                         logger.warn("Client request rejected: {}", e.getMessage());
                         closeConnection(session, e.getStatus());
                     }
+                    catch (GuacamoleConnectionClosedException e) {
+                        logger.debug("Connection closed.", e);
+                        closeConnection(session, GuacamoleStatus.SUCCESS);
+                    }
                     catch (GuacamoleException e) {
                         logger.error("Internal server error.", e);
                         closeConnection(session, e.getStatus());
@@ -191,6 +196,9 @@ public abstract class GuacamoleWebSocketTunnelListener implements WebSocketListe
             // Write received message
             writer.write(message.toCharArray());
         }
+        catch (GuacamoleConnectionClosedException e) {
+            logger.debug("Connection closed.", e);
+        }
         catch (GuacamoleException e) {
             logger.debug("Tunnel write failed.", e);
         }

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/websocket/tomcat/GuacamoleWebSocketTunnelServlet.java

@@ -37,6 +37,7 @@ import org.apache.catalina.websocket.StreamInbound;
 import org.apache.catalina.websocket.WebSocketServlet;
 import org.apache.catalina.websocket.WsOutbound;
 import org.glyptodon.guacamole.GuacamoleClientException;
+import org.glyptodon.guacamole.GuacamoleConnectionClosedException;
 import org.glyptodon.guacamole.protocol.GuacamoleStatus;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -120,6 +121,9 @@ public abstract class GuacamoleWebSocketTunnelServlet extends WebSocketServlet {
                         writer.write(buffer, 0, num_read);
 
                 }
+                catch (GuacamoleConnectionClosedException e) {
+                    logger.debug("Connection closed.", e);
+                }
                 catch (GuacamoleException e) {
                     logger.debug("Tunnel write failed.", e);
                 }
@@ -180,6 +184,10 @@ public abstract class GuacamoleWebSocketTunnelServlet extends WebSocketServlet {
                                 logger.warn("Client request rejected: {}", e.getMessage());
                                 closeConnection(outbound, e.getStatus());
                             }
+                            catch (GuacamoleConnectionClosedException e) {
+                                logger.debug("Connection closed.", e);
+                                closeConnection(outbound, GuacamoleStatus.SUCCESS);
+                            }
                             catch (GuacamoleException e) {
                                 logger.error("Internal server error.", e);
                                 closeConnection(outbound, e.getStatus());