Ensure messages are delivered by TelnetAppender when the socket is in a TIME_WAIT state (#495)

Co-authored-by: Michiel De Witte <[email protected]>

Author: michieldwitte

src/main/cpp/aprserversocket.cpp

@@ -35,7 +35,12 @@ struct APRServerSocket::APRServerSocketPriv : public ServerSocketPrivate {
 	apr_socket_t* socket;
 };
 
-APRServerSocket::APRServerSocket(int port) :
+#if LOG4CXX_ABI_VERSION <= 15
+APRServerSocket::APRServerSocket(int port) : 
+	APRServerSocket(port, false) {}
+#endif
+
+APRServerSocket::APRServerSocket(int port, bool reuseAddress) :
 	ServerSocket(std::make_unique<APRServerSocketPriv>()){
 	apr_status_t status =
 		apr_socket_create(&_priv->socket, APR_INET, SOCK_STREAM,
@@ -53,6 +58,15 @@ APRServerSocket::APRServerSocket(int port) :
 		throw SocketException(status);
 	}
 
+	if (reuseAddress) {
+		apr_status_t status = apr_socket_opt_set(_priv->socket, APR_SO_REUSEADDR, 1);
+
+		if (status != APR_SUCCESS)
+		{
+			throw SocketException(status);
+		}
+	}
+
 	// Create server socket address (including port number)
 	apr_sockaddr_t* server_addr;
 	status =

src/main/cpp/serversocket.cpp

@@ -51,6 +51,12 @@ void ServerSocket::setSoTimeout(int newVal)
 	m_priv->timeout = newVal;
 }
 
+#if LOG4CXX_ABI_VERSION <= 15
 ServerSocketUniquePtr ServerSocket::create(int port){
 	return std::make_unique<APRServerSocket>(port);
 }
+#endif
+
+ServerSocketUniquePtr ServerSocket::create(int port, bool reuseAddress){
+	return std::make_unique<APRServerSocket>(port, reuseAddress);
+}

src/main/cpp/telnetappender.cpp

@@ -58,6 +58,7 @@ struct TelnetAppender::TelnetAppenderPriv : public AppenderSkeletonPrivate
 	{ stopAcceptingConnections(); }
 
 	int port;
+	bool reuseAddress = false;
 	ConnectionList connections;
 	LogString encoding;
 	LOG4CXX_NS::helpers::CharsetEncoderPtr encoder;
@@ -112,7 +113,7 @@ void TelnetAppender::activateOptions(Pool& /* p */)
 {
 	if (_priv->serverSocket == NULL)
 	{
-		_priv->serverSocket = ServerSocket::create(_priv->port);
+		_priv->serverSocket = ServerSocket::create(_priv->port, _priv->reuseAddress);
 		_priv->serverSocket->setSoTimeout(1000);
 	}
 
@@ -135,6 +136,10 @@ void TelnetAppender::setOption(const LogString& option,
 	{
 		setEncoding(value);
 	}
+	else if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("REUSEADDRESS"), LOG4CXX_STR("reuseaddress")))
+	{
+		setReuseAddress(OptionConverter::toBoolean(value, true));
+	}
 	else
 	{
 		AppenderSkeleton::setOption(option, value);
@@ -358,6 +363,11 @@ void TelnetAppender::setMaxConnections(int newValue)
 	}
 }
 
+void TelnetAppender::setReuseAddress(bool reuseAddress)
+{
+	_priv->reuseAddress = reuseAddress;
+}
+
 bool TelnetAppender::requiresLayout() const
 {
 	return false;

src/main/include/log4cxx/helpers/serversocket.h

@@ -57,7 +57,12 @@ class LOG4CXX_EXPORT ServerSocket
 		*/
 		void setSoTimeout(int timeout);
 
+#if LOG4CXX_ABI_VERSION <= 15
 		static ServerSocketUniquePtr create(int port);
+		static ServerSocketUniquePtr create(int port, bool reuseAddress);
+#else
+		static ServerSocketUniquePtr create(int port, bool reuseAddress = false);
+#endif
 
 };
 }  // namespace helpers

src/main/include/log4cxx/net/telnetappender.h

@@ -42,6 +42,9 @@ especially when monitoring a servlet remotely.
 
 If no layout is provided, the log message only is sent to attached client(s).
 
+The ReuseAddress option is disabled by default,
+enable it if you want it to be able to bind to the address immediately after restarting / crashing
+
 See TelnetAppender::setOption() for the available options.
 
 */
@@ -96,6 +99,7 @@ class LOG4CXX_EXPORT TelnetAppender : public AppenderSkeleton
 		Port | {int} | 23
 		MaxConnections | {int} | 20
 		Encoding | C,UTF-8,UTF-16,UTF-16BE,UTF-16LE,646,US-ASCII,ISO646-US,ANSI_X3.4-1968,ISO-8859-1,ISO-LATIN-1 | UTF-8
+		ReuseAddress | True,False | True
 
 		\sa AppenderSkeleton::setOption()
 		*/
@@ -125,6 +129,14 @@ class LOG4CXX_EXPORT TelnetAppender : public AppenderSkeleton
 		 */
 		void setMaxConnections(int newValue);
 
+		/**
+		Set the SO_REUSEADDR option to of the server socket.
+		This allows the socket to bind to an address that is in a TIME_WAIT state.
+		This is useful for restarting immediately after it has been closed.
+
+		\sa setOption
+		 */
+		void setReuseAddress(bool reuseAddress);
 
 		/** Shutdown this appender. */
 		void close() override;

src/main/include/log4cxx/private/aprserversocket.h

@@ -31,7 +31,12 @@ namespace helpers
 class LOG4CXX_EXPORT APRServerSocket : public helpers::ServerSocket
 {
         public:
+#if LOG4CXX_ABI_VERSION <= 15
             APRServerSocket(int port);
+            APRServerSocket(int port, bool reuseAddress);
+#else
+            APRServerSocket(int port, bool reuseAddress = false);
+#endif
 
 	    void close() override;
 

src/test/cpp/net/socketappendertestcase.cpp

@@ -80,7 +80,7 @@ class SocketAppenderTestCase : public AppenderSkeletonTestCase
 			helpers::ServerSocketUniquePtr serverSocket;
 			try
 			{
-				serverSocket = helpers::ServerSocket::create(tcpPort);
+				serverSocket = helpers::ServerSocket::create(tcpPort, true);
 			}
 			catch (std::exception& ex)
 			{

src/test/cpp/net/telnetappendertestcase.cpp

@@ -105,6 +105,7 @@ class TelnetAppenderTestCase : public AppenderSkeletonTestCase
 			TelnetAppenderPtr appender(new TelnetAppender());
 			appender->setPort(TEST_PORT);
 			appender->setMaxConnections(1);
+			appender->setReuseAddress(true);
 			Pool p;
 			appender->activateOptions(p);
 			LoggerPtr root(Logger::getRootLogger());