Add ReadLine with timeouts

Implement PING
Handle QUIT, STOP, EXIT
synch DatagramServer start/stop

apps/sam/java/src/net/i2p/sam/ReadLine.java

+package net.i2p.sam;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.Socket;
+import java.net.SocketException;
+import java.net.SocketTimeoutException;
+
+/**
+ * Modified from I2PTunnelHTTPServer
+ *
+ * @since 0.9.22
+ */
+class ReadLine {
+
+    private static final int MAX_LINE_LENGTH = 8*1024;
+
+    /**
+     *  Read a line teriminated by newline, with a total read timeout.
+     *
+     *  Warning - strips \n but not \r
+     *  Warning - 8KB line length limit as of 0.7.13, @throws IOException if exceeded
+     *
+     *  @param buf output
+     *  @param timeout throws SocketTimeoutException immediately if zero or negative
+     *  @throws SocketTimeoutException if timeout is reached before newline
+     *  @throws EOFException if EOF is reached before newline
+     *  @throws LineTooLongException if too long
+     *  @throws IOException on other errors in the underlying stream
+     */
+    public static void readLine(Socket socket, StringBuilder buf, int timeout) throws IOException {
+        if (timeout <= 0)
+            throw new SocketTimeoutException();
+        long expires = System.currentTimeMillis() + timeout;
+        InputStreamReader in = new InputStreamReader(socket.getInputStream(), "UTF-8");
+        int c;
+        int i = 0;
+        socket.setSoTimeout(timeout);
+        while ( (c = in.read()) != -1) {
+            if (++i > MAX_LINE_LENGTH)
+                throw new LineTooLongException("Line too long - max " + MAX_LINE_LENGTH);
+            if (c == '\n')
+                break;
+            int newTimeout = (int) (expires - System.currentTimeMillis());
+            if (newTimeout <= 0)
+                throw new SocketTimeoutException();
+            buf.append((char)c);
+            if (newTimeout != timeout) {
+                timeout = newTimeout;
+                socket.setSoTimeout(timeout);
+            }
+        }
+        if (c == -1) {
+            if (System.currentTimeMillis() >= expires)
+                throw new SocketTimeoutException();
+            else
+                throw new EOFException();
+        }
+    }
+
+    private static class LineTooLongException extends IOException {
+        public LineTooLongException(String s) {
+            super(s);
+        }
+    }
+}
+
+

apps/sam/java/src/net/i2p/sam/SAMv3DatagramServer.java

@@ -97,7 +97,7 @@ class SAMv3DatagramServer implements Handler {
 	 *  Only call once.
 	 *  @since 0.9.22
 	 */
-	public void start() {
+	private synchronized void start() {
 		_listener.start();
 		if (_parent != null)
 			_parent.register(this);
@@ -107,7 +107,7 @@ class SAMv3DatagramServer implements Handler {
 	 *  Cannot be restarted.
 	 *  @since 0.9.22
 	 */
-	public void stopHandling() {
+	public synchronized void stopHandling() {
 		synchronized(SAMv3DatagramServer.class) {
 			if (server != null) {
 				try {

apps/sam/java/src/net/i2p/sam/SAMv3Handler.java

@@ -15,7 +15,10 @@ import java.io.InputStream;
 import java.io.InterruptedIOException;
 import java.net.ConnectException;
 import java.net.InetSocketAddress;
+import java.net.Socket;
 import java.net.SocketAddress;
+import java.net.SocketException;
+import java.net.SocketTimeoutException;
 import java.net.NoRouteToHostException;
 import java.nio.channels.SocketChannel;
 import java.nio.ByteBuffer;
@@ -51,6 +54,8 @@ class SAMv3Handler extends SAMv1Handler
 	private volatile boolean stolenSocket;
 	private volatile boolean streamForwardingSocket;
 	private final boolean sendPorts;
+	private long _lastPing;
+	private static final int READ_TIMEOUT = 3*60*1000;
 	
 	interface Session {
 		String getNick();
@@ -226,6 +231,11 @@ class SAMv3Handler extends SAMv1Handler
 	public void stealSocket()
 	{
 		stolenSocket = true ;
+		if (sendPorts) {
+			try {
+			       socket.socket().setSoTimeout(0);
+			} catch (SocketException se) {}
+		}
 		this.stopHandling();
 	}
 	
@@ -246,6 +256,7 @@ class SAMv3Handler extends SAMv1Handler
 		return session;
 	}
 	
+	@Override
 	public void handle() {
 		String msg = null;
 		String domain = null;
@@ -259,15 +270,72 @@ class SAMv3Handler extends SAMv1Handler
 			_log.debug("SAMv3 handling started");
 
 		try {
-			InputStream in = getClientSocket().socket().getInputStream();
+			Socket socket = getClientSocket().socket();
+			InputStream in = socket.getInputStream();
 
+			StringBuilder buf = new StringBuilder(1024);
 			while (true) {
 				if (shouldStop()) {
 					if (_log.shouldLog(Log.DEBUG))
 						_log.debug("Stop request found");
 					break;
 				}
-				String line = DataHelper.readLine(in) ;
+				String line;
+				if (sendPorts) {
+					// client supports PING
+					try {
+						ReadLine.readLine(socket, buf, READ_TIMEOUT);
+						line = buf.toString();
+						buf.setLength(0);					
+					} catch (SocketTimeoutException ste) {
+						long now = System.currentTimeMillis();
+						if (buf.length() <= 0) {
+							if (_lastPing > 0) {
+								if (now - _lastPing >= READ_TIMEOUT) {
+									if (_log.shouldWarn())
+										_log.warn("Failed to respond to PING");
+									writeString("PING STATUS RESULT=I2P_ERROR MESSAGE=\"PONG timeout\"\n");
+									break;
+								}
+							} else {
+								if (_log.shouldDebug())
+									_log.debug("Sendng PING " + now);
+								_lastPing = now;
+								if (!writeString("PING " + now + '\n'))
+									break;
+							}
+						} else {
+							if (_lastPing > 0) {
+								if (now - _lastPing >= 2*READ_TIMEOUT) {
+									if (_log.shouldWarn())
+										_log.warn("Failed to respond to PING");
+									writeString("PING STATUS RESULT=I2P_ERROR MESSAGE=\"PONG timeout\"\n");
+									break;
+								}
+							} else if (_lastPing < 0) {
+								if (_log.shouldWarn())
+									_log.warn("2nd timeout");
+								writeString("XXX STATUS RESULT=I2P_ERROR MESSAGE=\"command timeout, bye\"\n");
+								break;
+							} else {
+								// don't clear buffer, don't send ping,
+								// go around again
+								_lastPing = -1;
+								if (_log.shouldWarn())
+									_log.warn("timeout after partial: " + buf);
+							}
+						}
+						if (_log.shouldDebug())
+							_log.debug("loop after timeout");
+						continue;
+					}
+				} else {
+					buf.setLength(0);					
+					if (DataHelper.readLine(in, buf))
+						line = buf.toString();
+					else
+						line = null;
+				}
 				if (line==null) {
 					if (_log.shouldLog(Log.DEBUG))
 						_log.debug("Connection closed by client (line read : null)");
@@ -302,6 +370,10 @@ class SAMv3Handler extends SAMv1Handler
 				} else if (domain.equals("PONG")) {
 					execPongMessage(tok);
 					continue;
+				} else if (domain.equals("QUIT") || domain.equals("STOP") ||
+				           domain.equals("EXIT")) {
+					writeString(domain + " STATUS RESULT=OK MESSAGE=bye\n");
+					break;
 				}
 				if (count <= 1) {
 					// This is not a correct message, for sure
@@ -345,7 +417,7 @@ class SAMv3Handler extends SAMv1Handler
 				if (!canContinue) {
 					break;
 				}
-			}
+			} // while
 		} catch (IOException e) {
 			if (_log.shouldLog(Log.DEBUG))
 				_log.debug("Caught IOException for message [" + msg + "]", e);
@@ -855,7 +927,26 @@ class SAMv3Handler extends SAMv1Handler
 	 * @since 0.9.22
 	 */
 	private void execPongMessage(StringTokenizer tok) {
-		// TODO. We don't send PINGs yet.
+		String s;
+		if (tok.hasMoreTokens()) {
+			s = tok.nextToken();
+		} else {
+			s = "";
+		}
+		if (_lastPing > 0) {
+			String expected = Long.toString(_lastPing);
+			if (expected.equals(s)) {
+				_lastPing = 0;
+				if (_log.shouldInfo())
+					_log.warn("Got expected pong: " + s);
+			} else {
+				if (_log.shouldInfo())
+					_log.warn("Got unexpected pong: " + s);
+			}
+		} else {
+			if (_log.shouldWarn())
+				_log.warn("Pong received without a ping: " + s);
+		}
 	}
 }