Better polling. Fixed possible connection issues on POSIX with slow network. Better error handling in POSIX sockets.

21 files changed, 373 insertions, 210 deletions

diff --git a/src/vmime/net/imap/IMAPParser.hpp b/src/vmime/net/imap/IMAPParser.hpp
index 533f78fb..4ea9cb57 100644
--- a/src/vmime/net/imap/IMAPParser.hpp
+++ b/src/vmime/net/imap/IMAPParser.hpp
@@ -5748,7 +5748,11 @@ public:
 
 			if (receiveBuffer.empty())   // buffer is empty
 			{
-				platform::getHandler()->wait();
+				if (sok->getStatus() & socket::STATUS_WANT_WRITE)
+					sok->waitForWrite();
+				else
+					sok->waitForRead();
+
 				continue;
 			}
 
@@ -5807,7 +5811,11 @@ public:
 
 			if (receiveBuffer.empty())   // buffer is empty
 			{
-				platform::getHandler()->wait();
+				if (sok->getStatus() & socket::STATUS_WANT_WRITE)
+					sok->waitForWrite();
+				else
+					sok->waitForRead();
+
 				continue;
 			}
 
diff --git a/src/vmime/net/pop3/POP3Response.cpp b/src/vmime/net/pop3/POP3Response.cpp
index 1dc5ee76..a3961200 100644
--- a/src/vmime/net/pop3/POP3Response.cpp
+++ b/src/vmime/net/pop3/POP3Response.cpp
@@ -178,7 +178,11 @@ void POP3Response::readResponseImpl(string& buffer, const bool multiLine)
 
 		if (receiveBuffer.empty())   // buffer is empty
 		{
-			platform::getHandler()->wait();
+			if (m_socket->getStatus() & socket::STATUS_WANT_WRITE)
+				m_socket->waitForWrite();
+			else
+				m_socket->waitForRead();
+
 			continue;
 		}
 
@@ -269,7 +273,11 @@ void POP3Response::readResponseImpl
 
 		if (read == 0)   // buffer is empty
 		{
-			platform::getHandler()->wait();
+			if (m_socket->getStatus() & socket::STATUS_WANT_WRITE)
+				m_socket->waitForWrite();
+			else
+				m_socket->waitForRead();
+
 			continue;
 		}
 
diff --git a/src/vmime/net/smtp/SMTPResponse.cpp b/src/vmime/net/smtp/SMTPResponse.cpp
index f7980351..3d8bf15c 100644
--- a/src/vmime/net/smtp/SMTPResponse.cpp
+++ b/src/vmime/net/smtp/SMTPResponse.cpp
@@ -160,7 +160,7 @@ const string SMTPResponse::readResponseLine()
 
 		if (receiveBuffer.empty())   // buffer is empty
 		{
-			platform::getHandler()->wait();
+			m_socket->waitForRead();
 			continue;
 		}
 
diff --git a/src/vmime/net/socket.hpp b/src/vmime/net/socket.hpp
index 7f878a73..72f0445f 100644
--- a/src/vmime/net/socket.hpp
+++ b/src/vmime/net/socket.hpp
@@ -49,7 +49,9 @@ public:
 
 	enum Status
 	{
-		STATUS_WOULDBLOCK = 0x1   /**< The receive operation would block. */
+		STATUS_WOULDBLOCK = 0xf,    /**< The operation would block. Retry later. */
+		STATUS_WANT_READ = 0x1,     /**< The socket wants to read data, retry when data is available. */
+		STATUS_WANT_WRITE = 0x2     /**< The socket wants to write data, retry when data can be written. */
 	};
 
 
@@ -74,6 +76,25 @@ public:
 	  */
 	virtual bool isConnected() const = 0;
 
+	/** Block until new data is available for reading. The function will
+	  * timeout after msecs milliseconds.
+	  *
+	  * @param timeout maximum wait time, in milliseconds (default is 30000);
+	  * resolution is 10ms
+	  * @return true if data is available, or false if the operation timed out
+	  */
+	virtual bool waitForRead(const int msecs = 30000) = 0;
+
+	/** Block until pending data has been written and new data can be written.
+	  * The function will timeout after msecs milliseconds.
+	  *
+	  * @param timeout maximum wait time, in milliseconds (default is 30000);
+	  * resolution is 10ms
+	  * @return true if new data can be written immediately, or false if the
+	  * operation timed out
+	  */
+	virtual bool waitForWrite(const int msecs = 30000) = 0;
+
 	/** Receive text data from the socket.
 	  *
 	  * @param buffer buffer in which to write received data
diff --git a/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.cpp b/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.cpp
index 13b7eb24..3832326c 100644
--- a/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.cpp
+++ b/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.cpp
@@ -30,6 +30,8 @@
 #include <gnutls/gnutls.h>
 #include <gnutls/x509.h>
 
+#include <errno.h>
+
 #include "vmime/net/tls/gnutls/TLSSocket_GnuTLS.hpp"
 #include "vmime/net/tls/gnutls/TLSSession_GnuTLS.hpp"
 
@@ -57,7 +59,7 @@ shared_ptr <TLSSocket> TLSSocket::wrap(shared_ptr <TLSSession> session, shared_p
 
 TLSSocket_GnuTLS::TLSSocket_GnuTLS(shared_ptr <TLSSession_GnuTLS> session, shared_ptr <socket> sok)
 	: m_session(session), m_wrapped(sok), m_connected(false),
-	  m_handshaking(false), m_ex(NULL), m_status(0)
+	  m_ex(NULL), m_status(0)
 {
 	gnutls_transport_set_ptr(*m_session->m_gnutlsSession, this);
 
@@ -144,6 +146,18 @@ shared_ptr <timeoutHandler> TLSSocket_GnuTLS::getTimeoutHandler()
 }
 
 
+bool TLSSocket_GnuTLS::waitForRead(const int msecs)
+{
+	return m_wrapped->waitForRead(msecs);
+}
+
+
+bool TLSSocket_GnuTLS::waitForWrite(const int msecs)
+{
+	return m_wrapped->waitForWrite(msecs);
+}
+
+
 void TLSSocket_GnuTLS::receive(string& buffer)
 {
 	const size_t size = receiveRaw(m_buffer, sizeof(m_buffer));
@@ -165,7 +179,7 @@ void TLSSocket_GnuTLS::send(const char* str)
 
 size_t TLSSocket_GnuTLS::receiveRaw(byte_t* buffer, const size_t count)
 {
-	m_status &= ~STATUS_WOULDBLOCK;
+	m_status &= ~(STATUS_WANT_WRITE | STATUS_WANT_READ);
 
 	const ssize_t ret = gnutls_record_recv
 		(*m_session->m_gnutlsSession,
@@ -178,7 +192,11 @@ size_t TLSSocket_GnuTLS::receiveRaw(byte_t* buffer, const size_t count)
 	{
 		if (ret == GNUTLS_E_AGAIN)
 		{
-			m_status |= STATUS_WOULDBLOCK;
+			if (gnutls_record_get_direction(*m_session->m_gnutlsSession) == 0)
+				m_status |= STATUS_WANT_READ;
+			else
+				m_status |= STATUS_WANT_WRITE;
+
 			return 0;
 		}
 
@@ -191,7 +209,7 @@ size_t TLSSocket_GnuTLS::receiveRaw(byte_t* buffer, const size_t count)
 
 void TLSSocket_GnuTLS::sendRaw(const byte_t* buffer, const size_t count)
 {
-	m_status &= ~STATUS_WOULDBLOCK;
+	m_status &= ~(STATUS_WANT_WRITE | STATUS_WANT_READ);
 
 	for (size_t size = count ; size > 0 ; )
 	{
@@ -206,7 +224,11 @@ void TLSSocket_GnuTLS::sendRaw(const byte_t* buffer, const size_t count)
 		{
 			if (ret == GNUTLS_E_AGAIN)
 			{
-				platform::getHandler()->wait();
+				if (gnutls_record_get_direction(*m_session->m_gnutlsSession) == 0)
+					m_wrapped->waitForRead();
+				else
+					m_wrapped->waitForWrite();
+
 				continue;
 			}
 
@@ -223,6 +245,8 @@ void TLSSocket_GnuTLS::sendRaw(const byte_t* buffer, const size_t count)
 
 size_t TLSSocket_GnuTLS::sendRawNonBlocking(const byte_t* buffer, const size_t count)
 {
+	m_status &= ~(STATUS_WANT_WRITE | STATUS_WANT_READ);
+
 	ssize_t ret = gnutls_record_send
 		(*m_session->m_gnutlsSession,
 		 buffer, static_cast <size_t>(count));
@@ -234,7 +258,11 @@ size_t TLSSocket_GnuTLS::sendRawNonBlocking(const byte_t* buffer, const size_t c
 	{
 		if (ret == GNUTLS_E_AGAIN)
 		{
-			m_status |= STATUS_WOULDBLOCK;
+			if (gnutls_record_get_direction(*m_session->m_gnutlsSession) == 0)
+				m_status |= STATUS_WANT_READ;
+			else
+				m_status |= STATUS_WANT_WRITE;
+
 			return 0;
 		}
 
@@ -259,8 +287,6 @@ void TLSSocket_GnuTLS::handshake()
 		toHandler->resetTimeOut();
 
 	// Start handshaking process
-	m_handshaking = true;
-
 	try
 	{
 		while (true)
@@ -272,11 +298,17 @@ void TLSSocket_GnuTLS::handshake()
 
 			if (ret < 0)
 			{
-				if (ret == GNUTLS_E_AGAIN ||
-				    ret == GNUTLS_E_INTERRUPTED)
+				if (ret == GNUTLS_E_AGAIN)
+				{
+					if (gnutls_record_get_direction(*m_session->m_gnutlsSession) == 0)
+						m_wrapped->waitForRead();
+					else
+						m_wrapped->waitForWrite();
+				}
+				else if (ret == GNUTLS_E_INTERRUPTED)
 				{
 					// Non-fatal error
-					platform::getHandler()->wait();
+					m_wrapped->waitForRead();
 				}
 				else
 				{
@@ -292,12 +324,9 @@ void TLSSocket_GnuTLS::handshake()
 	}
 	catch (...)
 	{
-		m_handshaking = false;
 		throw;
 	}
 
-	m_handshaking = false;
-
 	// Verify server's certificate(s)
 	shared_ptr <security::cert::certificateChain> certs = getPeerCertificates();
 
@@ -321,14 +350,21 @@ ssize_t TLSSocket_GnuTLS::gnutlsPushFunc
 			(sok->m_wrapped->sendRawNonBlocking
 				(reinterpret_cast <const byte_t*>(data), len));
 
-		if (ret == 0 && sok->m_wrapped->getStatus() & socket::STATUS_WOULDBLOCK)
-			return GNUTLS_E_AGAIN;
+		if (ret == 0)
+		{
+			if (sok->m_wrapped->getStatus() & socket::STATUS_WOULDBLOCK)
+				gnutls_transport_set_errno(*sok->m_session->m_gnutlsSession, EAGAIN);
+			else
+				gnutls_transport_set_errno(*sok->m_session->m_gnutlsSession, 0);
+
+			return -1;
+		}
 
 		return ret;
 	}
 	catch (exception& e)
 	{
-		// Workaround for bad behaviour when throwing C++ exceptions
+		// Workaround for non-portable behaviour when throwing C++ exceptions
 		// from C functions (GNU TLS)
 		sok->m_ex = e.clone();
 		return -1;
@@ -343,54 +379,25 @@ ssize_t TLSSocket_GnuTLS::gnutlsPullFunc
 
 	try
 	{
-		// Workaround for cross-platform asynchronous handshaking:
-		// gnutls_handshake() only returns GNUTLS_E_AGAIN if recv()
-		// returns -1 and errno is set to EGAIN...
-		if (sok->m_handshaking)
-		{
-			shared_ptr <timeoutHandler> toHandler = sok->m_wrapped->getTimeoutHandler();
-
-			while (true)
-			{
-				const ssize_t ret = static_cast <ssize_t>
-					(sok->m_wrapped->receiveRaw
-						(reinterpret_cast <byte_t*>(data), len));
+		const ssize_t n = static_cast <ssize_t>
+			(sok->m_wrapped->receiveRaw
+				(reinterpret_cast <byte_t*>(data), len));
 
-				if (ret == 0)
-				{
-					// No data available yet
-					platform::getHandler()->wait();
-				}
-				else
-				{
-					return ret;
-				}
-
-				// Check whether the time-out delay is elapsed
-				if (toHandler && toHandler->isTimeOut())
-				{
-					if (!toHandler->handleTimeOut())
-						throw exceptions::operation_timed_out();
-
-					toHandler->resetTimeOut();
-				}
-			}
-		}
-		else
+		if (n == 0)
 		{
-			const ssize_t n = static_cast <ssize_t>
-				(sok->m_wrapped->receiveRaw
-					(reinterpret_cast <byte_t*>(data), len));
-
-			if (n == 0 && sok->m_wrapped->getStatus() & socket::STATUS_WOULDBLOCK)
-				return GNUTLS_E_AGAIN;
+			if (sok->m_wrapped->getStatus() & socket::STATUS_WOULDBLOCK)
+				gnutls_transport_set_errno(*sok->m_session->m_gnutlsSession, EAGAIN);
+			else
+				gnutls_transport_set_errno(*sok->m_session->m_gnutlsSession, 0);
 
-			return n;
+			return -1;
 		}
+
+		return n;
 	}
 	catch (exception& e)
 	{
-		// Workaround for bad behaviour when throwing C++ exceptions
+		// Workaround for non-portable behaviour when throwing C++ exceptions
 		// from C functions (GNU TLS)
 		sok->m_ex = e.clone();
 		return -1;
diff --git a/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.hpp b/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.hpp
index ddba9d0e..faa3a423 100644
--- a/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.hpp
+++ b/src/vmime/net/tls/gnutls/TLSSocket_GnuTLS.hpp
@@ -63,6 +63,9 @@ public:
 	void disconnect();
 	bool isConnected() const;
 
+	bool waitForRead(const int msecs = 30000);
+	bool waitForWrite(const int msecs = 30000);
+
 	void receive(string& buffer);
 	size_t receiveRaw(byte_t* buffer, const size_t count);
 
@@ -100,8 +103,6 @@ private:
 
 	byte_t m_buffer[65536];
 
-	bool m_handshaking;
-
 	exception* m_ex;
 
 	unsigned int m_status;
diff --git a/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.cpp b/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.cpp
index 595a0091..bec41612 100644
--- a/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.cpp
+++ b/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.cpp
@@ -113,7 +113,7 @@ void TLSSocket_OpenSSL::createSSLHandle()
 
 		SSL_set_bio(m_ssl, sockBio, sockBio);
 		SSL_set_connect_state(m_ssl);
-		SSL_set_mode(m_ssl, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
+		SSL_set_mode(m_ssl, SSL_MODE_AUTO_RETRY | SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 	}
 	else
 	{
@@ -193,6 +193,18 @@ shared_ptr <timeoutHandler> TLSSocket_OpenSSL::getTimeoutHandler()
 }
 
 
+bool TLSSocket_OpenSSL::waitForRead(const int msecs)
+{
+	return m_wrapped->waitForRead(msecs);
+}
+
+
+bool TLSSocket_OpenSSL::waitForWrite(const int msecs)
+{
+	return m_wrapped->waitForWrite(msecs);
+}
+
+
 void TLSSocket_OpenSSL::receive(string& buffer)
 {
 	const size_t size = receiveRaw(m_buffer, sizeof(m_buffer));
@@ -221,7 +233,7 @@ size_t TLSSocket_OpenSSL::receiveRaw(byte_t* buffer, const size_t count)
 	if (!m_ssl)
 		throw exceptions::socket_not_connected_exception();
 
-	m_status &= ~STATUS_WOULDBLOCK;
+	m_status &= ~(STATUS_WANT_WRITE | STATUS_WANT_READ);
 
 	int rc = SSL_read(m_ssl, buffer, static_cast <int>(count));
 
@@ -232,9 +244,14 @@ size_t TLSSocket_OpenSSL::receiveRaw(byte_t* buffer, const size_t count)
 	{
 		int error = SSL_get_error(m_ssl, rc);
 
-		if (error == SSL_ERROR_WANT_WRITE || error == SSL_ERROR_WANT_READ)
+		if (error == SSL_ERROR_WANT_WRITE)
+		{
+			m_status |= STATUS_WANT_WRITE;
+			return 0;
+		}
+		else if (error == SSL_ERROR_WANT_READ)
 		{
-			m_status |= STATUS_WOULDBLOCK;
+			m_status |= STATUS_WANT_READ;
 			return 0;
 		}
 
@@ -250,7 +267,7 @@ void TLSSocket_OpenSSL::sendRaw(const byte_t* buffer, const size_t count)
 	if (!m_ssl)
 		throw exceptions::socket_not_connected_exception();
 
-	m_status &= ~STATUS_WOULDBLOCK;
+	m_status &= ~(STATUS_WANT_WRITE | STATUS_WANT_READ);
 
 	for (size_t size = count ; size > 0 ; )
 	{
@@ -260,9 +277,14 @@ void TLSSocket_OpenSSL::sendRaw(const byte_t* buffer, const size_t count)
 		{
 			int error = SSL_get_error(m_ssl, rc);
 
-			if (error == SSL_ERROR_WANT_WRITE || error == SSL_ERROR_WANT_READ)
+			if (error == SSL_ERROR_WANT_READ)
+			{
+				m_wrapped->waitForRead();
+				continue;
+			}
+			else if (error == SSL_ERROR_WANT_WRITE)
 			{
-				platform::getHandler()->wait();
+				m_wrapped->waitForWrite();
 				continue;
 			}
 
@@ -282,7 +304,7 @@ size_t TLSSocket_OpenSSL::sendRawNonBlocking(const byte_t* buffer, const size_t
 	if (!m_ssl)
 		throw exceptions::socket_not_connected_exception();
 
-	m_status &= ~STATUS_WOULDBLOCK;
+	m_status &= ~(STATUS_WANT_WRITE | STATUS_WANT_READ);
 
 	int rc = SSL_write(m_ssl, buffer, static_cast <int>(count));
 
@@ -293,9 +315,14 @@ size_t TLSSocket_OpenSSL::sendRawNonBlocking(const byte_t* buffer, const size_t
 	{
 		int error = SSL_get_error(m_ssl, rc);
 
-		if (error == SSL_ERROR_WANT_WRITE || error == SSL_ERROR_WANT_READ)
+		if (error == SSL_ERROR_WANT_WRITE)
 		{
-			m_status |= STATUS_WOULDBLOCK;
+			m_status |= STATUS_WANT_WRITE;
+			return 0;
+		}
+		else if (error == SSL_ERROR_WANT_READ)
+		{
+			m_status |= STATUS_WANT_READ;
 			return 0;
 		}
 
@@ -328,15 +355,12 @@ void TLSSocket_OpenSSL::handshake()
 		{
 			const int err = SSL_get_error(m_ssl, rc);
 
- 			if (err == SSL_ERROR_WANT_READ || err == SSL_ERROR_WANT_WRITE)
- 			{
-				// No data available yet
-				platform::getHandler()->wait();
- 			}
- 			else
- 			{
- 				handleError(rc);
- 			}
+			if (err == SSL_ERROR_WANT_READ)
+				m_wrapped->waitForRead();
+			else if (err == SSL_ERROR_WANT_WRITE)
+				m_wrapped->waitForWrite();
+			else
+				handleError(rc);
 
 			// Check whether the time-out delay is elapsed
 			if (toHandler && toHandler->isTimeOut())
diff --git a/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.hpp b/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.hpp
index 5fbed19d..20712263 100644
--- a/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.hpp
+++ b/src/vmime/net/tls/openssl/TLSSocket_OpenSSL.hpp
@@ -67,6 +67,9 @@ public:
 	void disconnect();
 	bool isConnected() const;
 
+	bool waitForRead(const int msecs = 30000);
+	bool waitForWrite(const int msecs = 30000);
+
 	void receive(string& buffer);
 	size_t receiveRaw(byte_t* buffer, const size_t count);
 
@@ -115,7 +118,7 @@ private:
 	unsigned long m_status;
 
 	// Last exception thrown from C BIO functions
-	std::auto_ptr <std::exception> m_ex;
+	std::auto_ptr <exception> m_ex;
 };
 
 
diff --git a/src/vmime/platform.hpp b/src/vmime/platform.hpp
index c72f160e..ac1834ac 100644
--- a/src/vmime/platform.hpp
+++ b/src/vmime/platform.hpp
@@ -104,13 +104,6 @@ public:
 		  */
 		virtual const charset getLocalCharset() const = 0;
 
-		/** This function is called when VMime library is waiting for
-		  * something (for example, it is called when there is no data
-		  * available in a socket). On POSIX-compliant systems, a
-		  * simple call to sched_yield() should suffice.
-		  */
-		virtual void wait() const = 0;
-
 #if VMIME_HAVE_MESSAGING_FEATURES
 		/** Return a pointer to the default socket factory for
 		  * this platform.
diff --git a/src/vmime/platforms/posix/posixHandler.cpp b/src/vmime/platforms/posix/posixHandler.cpp
index e0bfd27f..f23f09ad 100644
--- a/src/vmime/platforms/posix/posixHandler.cpp
+++ b/src/vmime/platforms/posix/posixHandler.cpp
@@ -269,24 +269,6 @@ shared_ptr <vmime::utility::childProcessFactory> posixHandler::getChildProcessFa
 #endif
 
 
-void posixHandler::wait() const
-{
-/*
-#ifdef _POSIX_PRIORITY_SCHEDULING
-	::sched_yield();
-#else
-	::sleep(1);
-#endif // _POSIX_PRIORITY_SCHEDULING
-*/
-
-	struct timespec ts;
-	ts.tv_sec = 0;
-	ts.tv_nsec = 500000;  // 500 microseconds
-
-	nanosleep(&ts, NULL);
-}
-
-
 void posixHandler::generateRandomBytes(unsigned char* buffer, const unsigned int count)
 {
 	int fd = open("/dev/urandom", O_RDONLY);
diff --git a/src/vmime/platforms/posix/posixHandler.hpp b/src/vmime/platforms/posix/posixHandler.hpp
index 0bba372b..d9eb4fbd 100644
--- a/src/vmime/platforms/posix/posixHandler.hpp
+++ b/src/vmime/platforms/posix/posixHandler.hpp
@@ -76,8 +76,6 @@ public:
 	shared_ptr <vmime::utility::childProcessFactory> getChildProcessFactory();
 #endif
 
-	void wait() const;
-
 	void generateRandomBytes(unsigned char* buffer, const unsigned int count);
 
 	shared_ptr <utility::sync::criticalSection> createCriticalSection();
diff --git a/src/vmime/platforms/posix/posixSocket.cpp b/src/vmime/platforms/posix/posixSocket.cpp
index e7eba9f1..4bb709e6 100644
--- a/src/vmime/platforms/posix/posixSocket.cpp
+++ b/src/vmime/platforms/posix/posixSocket.cpp
@@ -34,6 +34,7 @@
 #include <sys/socket.h>
 #include <arpa/inet.h>
 #include <sys/types.h>
+#include <sys/time.h>
 #include <netinet/in.h>
 #include <netdb.h>
 #include <fcntl.h>
@@ -111,13 +112,23 @@ void posixSocket::connect(const vmime::string& address, const vmime::port_t port
 	// Connect to host
 	int sock = -1;
 	struct ::addrinfo* res = res0;
+	int connectErrno = 0;
 
-	for ( ; sock == -1 && res != NULL ; res = res->ai_next)
+	if (m_timeoutHandler != NULL)
+		m_timeoutHandler->resetTimeOut();
+
+	for ( ; sock == -1 && res != NULL ; res = res->ai_next, connectErrno = ETIMEDOUT)
 	{
+		if (res->ai_family != AF_INET && res->ai_family != AF_INET6)
+			continue;
+
 		sock = ::socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 
 		if (sock < 0)
+		{
+			connectErrno = errno;
 			continue;  // try next
+		}
 
 		if (m_timeoutHandler != NULL)
 		{
@@ -142,37 +153,51 @@ void posixSocket::connect(const vmime::string& address, const vmime::port_t port
 
 				default:
 
+					connectErrno = errno;
 					::close(sock);
 					sock = -1;
 					continue;  // try next
 				}
 
 				// Wait for socket to be connected.
-				// We will check for time out every second.
-				fd_set fds;
-				FD_ZERO(&fds);
-				FD_SET(sock, &fds);
-
-				fd_set fdsError;
-				FD_ZERO(&fdsError);
-				FD_SET(sock, &fdsError);
+				bool connected = false;
 
-				struct timeval tm;
-				tm.tv_sec = 1;
-				tm.tv_usec = 0;
+				const int selectTimeout = 1000;   // select() timeout (ms)
+				const int tryNextTimeout = 5000;  // maximum time before trying next (ms)
 
-				m_timeoutHandler->resetTimeOut();
-
-				bool connected = false;
+				timeval startTime = { 0, 0 };
+				gettimeofday(&startTime, /* timezone */ NULL);
 
 				do
 				{
-					const int ret = select(sock + 1, NULL, &fds, &fdsError, &tm);
+					struct timeval tm;
+					tm.tv_sec = selectTimeout / 1000;
+					tm.tv_usec = selectTimeout % 1000;
+
+					fd_set fds;
+					FD_ZERO(&fds);
+					FD_SET(sock, &fds);
+
+					const int ret = select(sock + 1, NULL, &fds, NULL, &tm);
 
 					// Success
 					if (ret > 0)
 					{
-						connected = true;
+						int error = 0;
+						socklen_t len = sizeof(error);
+
+						if (getsockopt(sock, SOL_SOCKET, SO_ERROR, &error, &len) < 0)
+						{
+							connectErrno = errno;
+						}
+						else
+						{
+							if (error != 0)
+								connectErrno = error;
+							else
+								connected = true;
+						}
+
 						break;
 					}
 					// Error
@@ -181,10 +206,11 @@ void posixSocket::connect(const vmime::string& address, const vmime::port_t port
 						if (errno != EINTR)
 						{
 							// Cancel connection
+							connectErrno = errno;
 							break;
 						}
 					}
-					// 1-second timeout
+					// Check for timeout
 					else if (ret == 0)
 					{
 						if (m_timeoutHandler->isTimeOut())
@@ -192,6 +218,7 @@ void posixSocket::connect(const vmime::string& address, const vmime::port_t port
 							if (!m_timeoutHandler->handleTimeOut())
 							{
 								// Cancel connection
+								connectErrno = ETIMEDOUT;
 								break;
 							}
 							else
@@ -206,7 +233,15 @@ void posixSocket::connect(const vmime::string& address, const vmime::port_t port
 						}
 					}
 
-					::sched_yield();
+					timeval curTime = { 0, 0 };
+					gettimeofday(&curTime, /* timezone */ NULL);
+
+					if (res->ai_next != NULL &&
+						curTime.tv_usec - startTime.tv_usec >= tryNextTimeout * 1000)
+					{
+						connectErrno = ETIMEDOUT;
+						break;
+					}
 
 				} while (true);
 
@@ -219,11 +254,17 @@ void posixSocket::connect(const vmime::string& address, const vmime::port_t port
 
 				break;
 			}
+			else
+			{
+				// Connection successful
+				break;
+			}
 		}
 		else
 		{
 			if (::connect(sock, res->ai_addr, res->ai_addrlen) < 0)
 			{
+				connectErrno = errno;
 				::close(sock);
 				sock = -1;
 				continue;  // try next
@@ -237,7 +278,7 @@ void posixSocket::connect(const vmime::string& address, const vmime::port_t port
 	{
 		try
 		{
-			throwSocketError(errno);
+			throwSocketError(connectErrno);
 		}
 		catch (exceptions::socket_exception& e)
 		{
@@ -434,6 +475,65 @@ size_t posixSocket::getBlockSize() const
 }
 
 
+bool posixSocket::waitForData(const bool read, const bool write, const int msecs)
+{
+	for (int i = 0 ; i <= msecs / 10 ; ++i)
+	{
+		// Check whether data is available
+		fd_set fds;
+		FD_ZERO(&fds);
+		FD_SET(m_desc, &fds);
+
+		struct timeval tv;
+		tv.tv_sec = 0;
+		tv.tv_usec = 10000;  // 10 ms
+
+		ssize_t ret = ::select(m_desc + 1, read ? &fds : NULL, write ? &fds : NULL, NULL, &tv);
+
+		if (ret <= 0)
+		{
+			if (ret < 0 && !IS_EAGAIN(errno))
+				throwSocketError(errno);
+
+			// No data available at this time
+			// Check if we are timed out
+			if (m_timeoutHandler &&
+			    m_timeoutHandler->isTimeOut())
+			{
+				if (!m_timeoutHandler->handleTimeOut())
+				{
+					// Server did not react within timeout delay
+					throw exceptions::operation_timed_out();
+				}
+				else
+				{
+					// Reset timeout
+					m_timeoutHandler->resetTimeOut();
+				}
+			}
+		}
+		else if (ret > 0)
+		{
+			return true;
+		}
+	}
+
+	return false;  // time out
+}
+
+
+bool posixSocket::waitForRead(const int msecs)
+{
+	return waitForData(/* read */ true, /* write */ false, msecs);
+}
+
+
+bool posixSocket::waitForWrite(const int msecs)
+{
+	return waitForData(/* read */ false, /* write */ true, msecs);
+}
+
+
 void posixSocket::receive(vmime::string& buffer)
 {
 	const size_t size = receiveRaw(m_buffer, sizeof(m_buffer));
@@ -446,38 +546,8 @@ size_t posixSocket::receiveRaw(byte_t* buffer, const size_t count)
 	m_status &= ~STATUS_WOULDBLOCK;
 
 	// Check whether data is available
-	fd_set fds;
-	FD_ZERO(&fds);
-	FD_SET(m_desc, &fds);
-
-	struct timeval tv;
-	tv.tv_sec = 1;
-	tv.tv_usec = 0;
-
-	ssize_t ret = ::select(m_desc + 1, &fds, NULL, NULL, &tv);
-
-	if (ret < 0)
+	if (!waitForRead(50 /* msecs */))
 	{
-		if (!IS_EAGAIN(errno))
-			throwSocketError(errno);
-
-		// No data available at this time
-		// Check if we are timed out
-		if (m_timeoutHandler &&
-		    m_timeoutHandler->isTimeOut())
-		{
-			if (!m_timeoutHandler->handleTimeOut())
-			{
-				// Server did not react within timeout delay
-				throwSocketError(errno);
-			}
-			else
-			{
-				// Reset timeout
-				m_timeoutHandler->resetTimeOut();
-			}
-		}
-
 		m_status |= STATUS_WOULDBLOCK;
 
 		// Continue waiting for data
@@ -485,7 +555,7 @@ size_t posixSocket::receiveRaw(byte_t* buffer, const size_t count)
 	}
 
 	// Read available data
-	ret = ::recv(m_desc, buffer, count, 0);
+	ssize_t ret = ::recv(m_desc, buffer, count, 0);
 
 	if (ret < 0)
 	{
@@ -556,7 +626,7 @@ void posixSocket::sendRaw(const byte_t* buffer, const size_t count)
 			if (ret < 0 && !IS_EAGAIN(errno))
 				throwSocketError(errno);
 
-			platform::getHandler()->wait();
+			waitForWrite(50 /* msecs */);
 		}
 		else
 		{
@@ -589,7 +659,7 @@ size_t posixSocket::sendRawNonBlocking(const byte_t* buffer, const size_t count)
 			if (!m_timeoutHandler->handleTimeOut())
 			{
 				// Could not send data within timeout delay
-				throwSocketError(errno);
+				throw exceptions::operation_timed_out();
 			}
 			else
 			{
diff --git a/src/vmime/platforms/posix/posixSocket.hpp b/src/vmime/platforms/posix/posixSocket.hpp
index 5d29d710..b8009154 100644
--- a/src/vmime/platforms/posix/posixSocket.hpp
+++ b/src/vmime/platforms/posix/posixSocket.hpp
@@ -50,6 +50,9 @@ public:
 	bool isConnected() const;
 	void disconnect();
 
+	bool waitForRead(const int msecs = 30000);
+	bool waitForWrite(const int msecs = 30000);
+
 	void receive(vmime::string& buffer);
 	size_t receiveRaw(byte_t* buffer, const size_t count);
 
@@ -69,6 +72,8 @@ public:
 
 protected:
 
+	bool waitForData(const bool read, const bool write, const int msecs);
+
 	static void throwSocketError(const int err);
 
 private:
diff --git a/src/vmime/platforms/windows/windowsHandler.cpp b/src/vmime/platforms/windows/windowsHandler.cpp
index 9c96b271..4bc32dae 100644
--- a/src/vmime/platforms/windows/windowsHandler.cpp
+++ b/src/vmime/platforms/windows/windowsHandler.cpp
@@ -299,12 +299,6 @@ shared_ptr <vmime::utility::childProcessFactory> windowsHandler::getChildProcess
 #endif
 
 
-void windowsHandler::wait() const
-{
-	::Sleep(100);
-}
-
-
 void windowsHandler::generateRandomBytes(unsigned char* buffer, const unsigned int count)
 {
 	HCRYPTPROV cryptProvider = 0;
diff --git a/src/vmime/platforms/windows/windowsHandler.hpp b/src/vmime/platforms/windows/windowsHandler.hpp
index 4a3678eb..b80f0de8 100644
--- a/src/vmime/platforms/windows/windowsHandler.hpp
+++ b/src/vmime/platforms/windows/windowsHandler.hpp
@@ -75,8 +75,6 @@ public:
 	shared_ptr <vmime::utility::childProcessFactory> getChildProcessFactory();
 #endif
 
-	void wait() const;
-
 	void generateRandomBytes(unsigned char* buffer, const unsigned int count);
 
 	shared_ptr <utility::sync::criticalSection> createCriticalSection();
diff --git a/src/vmime/platforms/windows/windowsSocket.cpp b/src/vmime/platforms/windows/windowsSocket.cpp
index bd20e5d4..d18fa1a1 100644
--- a/src/vmime/platforms/windows/windowsSocket.cpp
+++ b/src/vmime/platforms/windows/windowsSocket.cpp
@@ -249,10 +249,7 @@ size_t windowsSocket::receiveRaw(byte_t* buffer, const size_t count)
 	m_status &= ~STATUS_WOULDBLOCK;
 
 	// Check whether data is available
-	bool timedout;
-	waitForData(READ, timedout);
-
-	if (timedout)
+	if (!waitForRead(50 /* msecs */))
 	{
 		// No data available at this time
 		// Check if we are timed out
@@ -335,8 +332,7 @@ void windowsSocket::sendRaw(const byte_t* buffer, const size_t count)
 			if (err != WSAEWOULDBLOCK)
 				throwSocketError(err);
 
-			bool timedout;
-			waitForData(WRITE, timedout);
+			waitForWrite(50 /* msecs */);
 		}
 		else
 		{
@@ -430,33 +426,62 @@ void windowsSocket::throwSocketError(const int err)
 }
 
 
-void windowsSocket::waitForData(const WaitOpType t, bool& timedOut)
+bool windowsSocket::waitForData(const bool read, const bool write, const int msecs)
 {
-	// Check whether data is available
-	fd_set fds;
-	FD_ZERO(&fds);
-	FD_SET(m_desc, &fds);
-
-	struct timeval tv;
-	tv.tv_sec = 1;
-	tv.tv_usec = 0;
+	for (int i = 0 ; i <= msecs / 10 ; ++i)
+	{
+		// Check whether data is available
+		fd_set fds;
+		FD_ZERO(&fds);
+		FD_SET(m_desc, &fds);
 
-	int ret;
+		struct timeval tv;
+		tv.tv_sec = 0;
+		tv.tv_usec = 10000;  // 10 ms
 
-	if (t & READ)
-		ret = ::select(m_desc + 1, &fds, NULL, NULL, &tv);
-	else if (t & WRITE)
-		ret = ::select(m_desc + 1, NULL, &fds, NULL, &tv);
-	else
-		ret = ::select(m_desc + 1, &fds, &fds, NULL, &tv);
+		ssize_t ret = ::select(m_desc + 1, read ? &fds : NULL, write ? &fds : NULL, NULL, &tv);
 
-	timedOut = (ret == 0);
+		if (ret == SOCKET_ERROR)
+		{
+			int err = WSAGetLastError();
+			throwSocketError(err);
+		}
+		else if (ret > 0)
+		{
+			return true;
+		}
 
-	if (ret == SOCKET_ERROR)
-	{
-		int err = WSAGetLastError();
-		throwSocketError(err);
+		// No data available at this time
+		// Check if we are timed out
+		if (m_timeoutHandler &&
+		    m_timeoutHandler->isTimeOut())
+		{
+			if (!m_timeoutHandler->handleTimeOut())
+			{
+				// Server did not react within timeout delay
+				throw exceptions::operation_timed_out();
+			}
+			else
+			{
+				// Reset timeout
+				m_timeoutHandler->resetTimeOut();
+			}
+		}
 	}
+
+	return false;  // time out
+}
+
+
+bool windowsSocket::waitForRead(const int msecs)
+{
+	return waitForData(/* read */ true, /* write */ false, msecs);
+}
+
+
+bool windowsSocket::waitForWrite(const int msecs = 30000)
+{
+	return waitForData(/* read */ false, /* write */ true, msecs);
 }
 
 
diff --git a/src/vmime/platforms/windows/windowsSocket.hpp b/src/vmime/platforms/windows/windowsSocket.hpp
index 31e1488b..42ba3156 100644
--- a/src/vmime/platforms/windows/windowsSocket.hpp
+++ b/src/vmime/platforms/windows/windowsSocket.hpp
@@ -54,6 +54,9 @@ public:
 	bool isConnected() const;
 	void disconnect();
 
+	bool waitForRead(const int msecs = 30000);
+	bool waitForWrite(const int msecs = 30000);
+
 	void receive(vmime::string& buffer);
 	size_t receiveRaw(byte_t* buffer, const size_t count);
 	
@@ -75,14 +78,7 @@ protected:
 
 	void throwSocketError(const int err);
 
-	enum WaitOpType
-	{
-		READ  = 1,
-		WRITE = 2,
-		BOTH  = 4
-	};
-
-	void waitForData(const WaitOpType t, bool& timedOut);
+	bool waitForData(const bool read, const bool write, const int msecs);
 
 private:
 
diff --git a/src/vmime/security/sasl/SASLSocket.cpp b/src/vmime/security/sasl/SASLSocket.cpp
index 541fc904..de468fb3 100644
--- a/src/vmime/security/sasl/SASLSocket.cpp
+++ b/src/vmime/security/sasl/SASLSocket.cpp
@@ -102,6 +102,18 @@ shared_ptr <net::timeoutHandler> SASLSocket::getTimeoutHandler()
 }
 
 
+bool SASLSocket::waitForRead(const int msecs)
+{
+	return m_wrapped->waitForRead(msecs);
+}
+
+
+bool SASLSocket::waitForWrite(const int msecs)
+{
+	return m_wrapped->waitForWrite(msecs);
+}
+
+
 void SASLSocket::receive(string& buffer)
 {
 	const size_t n = receiveRaw(m_recvBuffer, sizeof(m_recvBuffer));
diff --git a/src/vmime/security/sasl/SASLSocket.hpp b/src/vmime/security/sasl/SASLSocket.hpp
index d2d82411..474d5596 100644
--- a/src/vmime/security/sasl/SASLSocket.hpp
+++ b/src/vmime/security/sasl/SASLSocket.hpp
@@ -58,6 +58,9 @@ public:
 
 	bool isConnected() const;
 
+	bool waitForRead(const int msecs = 30000);
+	bool waitForWrite(const int msecs = 30000);
+
 	void receive(string& buffer);
 	size_t receiveRaw(byte_t* buffer, const size_t count);
 
diff --git a/tests/testUtils.cpp b/tests/testUtils.cpp
index ee642bea..c4fce447 100644
--- a/tests/testUtils.cpp
+++ b/tests/testUtils.cpp
@@ -85,6 +85,18 @@ vmime::shared_ptr <vmime::net::timeoutHandler> testSocket::getTimeoutHandler()
 }
 
 
+bool testSocket::waitForRead(const int msecs)
+{
+	return true;
+}
+
+
+bool testSocket::waitForWrite(const int msecs)
+{
+	return true;
+}
+
+
 void testSocket::receive(vmime::string& buffer)
 {
 	buffer = m_inBuffer;
diff --git a/tests/testUtils.hpp b/tests/testUtils.hpp
index 9e72158a..20ebdf20 100644
--- a/tests/testUtils.hpp
+++ b/tests/testUtils.hpp
@@ -248,6 +248,9 @@ public:
 
 	bool isConnected() const;
 
+	bool waitForWrite(const int msecs = 30000);
+	bool waitForRead(const int msecs = 30000);
+
 	void receive(vmime::string& buffer);
 	void send(const vmime::string& buffer);
 	void send(const char* str);