Convert servers to cooperative multitasking

4 files changed, 108 insertions, 26 deletions

diff --git a/lib/libtdekrb/src/tdekrbclientsocket.cpp b/lib/libtdekrb/src/tdekrbclientsocket.cpp
index 9ea30fa..2736f5a 100644
--- a/lib/libtdekrb/src/tdekrbclientsocket.cpp
+++ b/lib/libtdekrb/src/tdekrbclientsocket.cpp
@@ -32,6 +32,20 @@
 
 #define NET_SEC_BUF_SIZE (2048)
 
+// When control comes back from processEvents() my object may be completely gone!  This attempts to mitigate the risk
+#define SAFELY_PROCESS_EVENTS		if (!m_canary) {		\
+						m_canary = new bool;	\
+						*m_canary = false;	\
+					}				\
+					bool* canary = m_canary;	\
+					tqApp->processEvents();		\
+					if (*canary == true) {		\
+						delete canary;		\
+						return -1;		\
+					}				\
+					delete m_canary;		\
+					m_canary = NULL;
+
 /* exception handling */
 struct exit_exception {
 	int c;
@@ -79,7 +93,7 @@ static int logSASLMessages(void *context __attribute__((unused)), int priority,
 	return SASL_OK;
 }
 
-TDEKerberosClientSocket::TDEKerberosClientSocket(TQObject *parent, const char *name) : TQSocket(parent, name), m_kerberosRequested(false), m_criticalSection(0), m_bufferLength(0), m_negotiatedMaxBufferSize(NET_SEC_BUF_SIZE) {
+TDEKerberosClientSocket::TDEKerberosClientSocket(TQObject *parent, const char *name) : TQSocket(parent, name), m_kerberosRequested(false), m_criticalSection(0), m_bufferLength(0), m_canary(NULL), m_negotiatedMaxBufferSize(NET_SEC_BUF_SIZE) {
 	saslData = new SASLDataPrivate;
 	saslData->m_krbConnection = NULL;
 	m_buffer = new TQBuffer();
@@ -87,6 +101,9 @@ TDEKerberosClientSocket::TDEKerberosClientSocket(TQObject *parent, const char *n
 }
 
 TDEKerberosClientSocket::~TDEKerberosClientSocket() {
+	if (m_canary) {
+		*m_canary = true;
+	}
 	m_buffer->close();
 	delete m_buffer;
 	delete saslData;
@@ -102,9 +119,6 @@ bool TDEKerberosClientSocket::open(int mode) {
 
 void TDEKerberosClientSocket::close() {
 	TQSocket::close();
-	if (m_criticalSection > 0) {
-		throw exit_exception(-1);
-	}
 }
 
 void TDEKerberosClientSocket::flush() {
@@ -221,6 +235,10 @@ TQ_LONG TDEKerberosClientSocket::readBlock(char *data, TQ_ULONG maxlen) {
 		int wrlen;
 		char* buf = (char*)malloc(m_negotiatedMaxBufferSize);
 		reclen = receiveEncryptedData(buf, m_negotiatedMaxBufferSize);
+		if (reclen < 0) {
+			free(buf);
+			return -1;
+		}
 		if (reclen > 0) {
 			m_buffer->at(m_bufferLength);
 			wrlen = m_buffer->writeBlock(buf, reclen);
@@ -278,6 +296,10 @@ TQ_LONG TDEKerberosClientSocket::readLine(char *data, TQ_ULONG maxlen) {
 		int wrlen;
 		char* buf = (char*)malloc(m_negotiatedMaxBufferSize);
 		reclen = receiveEncryptedData(buf, m_negotiatedMaxBufferSize);
+		if (reclen < 0) {
+			free(buf);
+			return -1;
+		}
 		if (reclen > 0) {
 			m_buffer->at(m_bufferLength);
 			wrlen = m_buffer->writeBlock(buf, reclen);
@@ -325,6 +347,10 @@ TQString TDEKerberosClientSocket::readLine() {
 		maxlen = m_negotiatedMaxBufferSize;
 		char* buf = (char*)malloc(m_negotiatedMaxBufferSize);
 		reclen = receiveEncryptedData(buf, m_negotiatedMaxBufferSize);
+		if (reclen < 0) {
+			free(buf);
+			return TQString::null;
+		}
 		if (reclen > 0) {
 			m_buffer->at(m_bufferLength);
 			wrlen = m_buffer->writeBlock(buf, reclen);
@@ -410,17 +436,25 @@ void TDEKerberosClientSocket::sendSASLDataToNetwork(const char *buffer, unsigned
 	free(buf);
 }
 
-int TDEKerberosClientSocket::getSASLDataFromNetwork(char *buf, int trunclen) {
+int TDEKerberosClientSocket::getSASLDataFromNetwork(char *buf, int trunclen, bool shouldblock) {
 	m_criticalSection++;
 	try {
 		unsigned int len;
 		int result;
-	
+
 		TQByteArray ba(2048);
-	
+
+		if (!shouldblock) {
+			if ((!TQSocket::canReadLine()) || (state() != TQSocket::Connected)) {
+				return 0;
+			}
+		}
+
 		len = 0;
 		while (1) {
-			tqApp->processEvents();
+			if (shouldblock) {
+				SAFELY_PROCESS_EVENTS
+			}
 			if (state() != TQSocket::Connected) {
 				m_criticalSection--;
 				return -1;
@@ -435,7 +469,13 @@ int TDEKerberosClientSocket::getSASLDataFromNetwork(char *buf, int trunclen) {
 				}
 			}
 			else {
-				usleep(1000);
+				if (shouldblock) {
+					
+					usleep(1000);
+				}
+				else {
+					break;
+				}
 			}
 			if (len >= (ba.size()-1)) {
 				ba.resize(ba.size()+2048);
@@ -486,21 +526,21 @@ int TDEKerberosClientSocket::transmitEncryptedData(int fd, const char* readbuf,
 		data_remaining = data_remaining - data_to_write_len;
 		remnant_position = remnant_position + data_to_write_len;
 		if (data_remaining > 0) {
-			tqApp->processEvents();
+			SAFELY_PROCESS_EVENTS
 		}
 	}
 
 	return 0;
 }
 
-int TDEKerberosClientSocket::receiveEncryptedData(char *buf, unsigned int trunclen) {
+int TDEKerberosClientSocket::receiveEncryptedData(char *buf, unsigned int trunclen, bool shouldblock) {
 	unsigned int recv_len;
 	const char *recv_data;
 	int result;
 	int len;
 
 	char *encbuf = (char*)malloc(m_negotiatedMaxBufferSize);
-	len = getSASLDataFromNetwork(encbuf, m_negotiatedMaxBufferSize);
+	len = getSASLDataFromNetwork(encbuf, m_negotiatedMaxBufferSize, shouldblock);
 	if (len < 0) {
 		return -1;
 	}
diff --git a/lib/libtdekrb/src/tdekrbclientsocket.h b/lib/libtdekrb/src/tdekrbclientsocket.h
index fde4eee..ddba47a 100644
--- a/lib/libtdekrb/src/tdekrbclientsocket.h
+++ b/lib/libtdekrb/src/tdekrbclientsocket.h
@@ -58,9 +58,9 @@ class TDEKerberosClientSocket : public TQSocket
 		int initializeKerberosInterface();
 		void freeKerberosConnection();
 		void sendSASLDataToNetwork(const char *buffer, unsigned length, int netfd);
-		int getSASLDataFromNetwork(char *buf, int trunclen);
+		int getSASLDataFromNetwork(char *buf, int trunclen, bool shouldblock=true);
 		int transmitEncryptedData(int fd, const char* readbuf, int cc);
-		int receiveEncryptedData(char *buf, unsigned int trunclen);
+		int receiveEncryptedData(char *buf, unsigned int trunclen, bool shouldblock=true);
 
 	private:
 		bool m_kerberosRequested;
@@ -69,6 +69,7 @@ class TDEKerberosClientSocket : public TQSocket
 		int m_criticalSection;
 		TQBuffer* m_buffer;
 		long m_bufferLength;
+		bool* m_canary;
 
 	private:
 		SASLDataPrivate *saslData;
diff --git a/lib/libtdekrb/src/tdekrbserversocket.cpp b/lib/libtdekrb/src/tdekrbserversocket.cpp
index 89cb05d..e1e2c02 100644
--- a/lib/libtdekrb/src/tdekrbserversocket.cpp
+++ b/lib/libtdekrb/src/tdekrbserversocket.cpp
@@ -32,6 +32,20 @@
 
 #define NET_SEC_BUF_SIZE (2048)
 
+// When control comes back from processEvents() my object may be completely gone!  This attempts to mitigate the risk
+#define SAFELY_PROCESS_EVENTS		if (!m_canary) {		\
+						m_canary = new bool;	\
+						*m_canary = false;	\
+					}				\
+					bool* canary = m_canary;	\
+					tqApp->processEvents();		\
+					if (*canary == true) {		\
+						delete canary;		\
+						return -1;		\
+					}				\
+					delete m_canary;		\
+					m_canary = NULL;
+
 /* exception handling */
 struct exit_exception {
 	int c;
@@ -79,7 +93,7 @@ static int logSASLMessages(void *context __attribute__((unused)), int priority,
 	return SASL_OK;
 }
 
-TDEKerberosServerSocket::TDEKerberosServerSocket(TQObject *parent, const char *name) : TQSocket(parent, name), m_kerberosRequested(false), m_criticalSection(0), m_bufferLength(0), m_negotiatedMaxBufferSize(NET_SEC_BUF_SIZE) {
+TDEKerberosServerSocket::TDEKerberosServerSocket(TQObject *parent, const char *name) : TQSocket(parent, name), m_kerberosRequested(false), m_criticalSection(0), m_bufferLength(0), m_canary(NULL), m_negotiatedMaxBufferSize(NET_SEC_BUF_SIZE) {
 	saslData = new SASLDataPrivate;
 	saslData->m_krbConnection = NULL;
 	m_buffer = new TQBuffer();
@@ -87,6 +101,9 @@ TDEKerberosServerSocket::TDEKerberosServerSocket(TQObject *parent, const char *n
 }
 
 TDEKerberosServerSocket::~TDEKerberosServerSocket() {
+	if (m_canary) {
+		*m_canary = true;
+	}
 	m_buffer->close();
 	delete m_buffer;
 	delete saslData;
@@ -102,9 +119,6 @@ bool TDEKerberosServerSocket::open(int mode) {
 
 void TDEKerberosServerSocket::close() {
 	TQSocket::close();
-	if (m_criticalSection > 0) {
-		throw exit_exception(-1);
-	}
 }
 
 void TDEKerberosServerSocket::flush() {
@@ -221,6 +235,10 @@ TQ_LONG TDEKerberosServerSocket::readBlock(char *data, TQ_ULONG maxlen) {
 		int wrlen;
 		char* buf = (char*)malloc(m_negotiatedMaxBufferSize);
 		reclen = receiveEncryptedData(buf, m_negotiatedMaxBufferSize);
+		if (reclen < 0) {
+			free(buf);
+			return -1;
+		}
 		if (reclen > 0) {
 			m_buffer->at(m_bufferLength);
 			wrlen = m_buffer->writeBlock(buf, reclen);
@@ -278,6 +296,10 @@ TQ_LONG TDEKerberosServerSocket::readLine(char *data, TQ_ULONG maxlen) {
 		int wrlen;
 		char* buf = (char*)malloc(m_negotiatedMaxBufferSize);
 		reclen = receiveEncryptedData(buf, m_negotiatedMaxBufferSize);
+		if (reclen < 0) {
+			free(buf);
+			return -1;
+		}
 		if (reclen > 0) {
 			m_buffer->at(m_bufferLength);
 			wrlen = m_buffer->writeBlock(buf, reclen);
@@ -325,6 +347,10 @@ TQString TDEKerberosServerSocket::readLine() {
 		maxlen = m_negotiatedMaxBufferSize;
 		char* buf = (char*)malloc(m_negotiatedMaxBufferSize);
 		reclen = receiveEncryptedData(buf, m_negotiatedMaxBufferSize);
+		if (reclen < 0) {
+			free(buf);
+			return TQString::null;
+		}
 		if (reclen > 0) {
 			m_buffer->at(m_bufferLength);
 			wrlen = m_buffer->writeBlock(buf, reclen);
@@ -410,7 +436,7 @@ void TDEKerberosServerSocket::sendSASLDataToNetwork(const char *buffer, unsigned
 	free(buf);
 }
 
-int TDEKerberosServerSocket::getSASLDataFromNetwork(char *buf, int trunclen) {
+int TDEKerberosServerSocket::getSASLDataFromNetwork(char *buf, int trunclen, bool shouldblock) {
 	m_criticalSection++;
 	try {
 		unsigned int len;
@@ -418,9 +444,17 @@ int TDEKerberosServerSocket::getSASLDataFromNetwork(char *buf, int trunclen) {
 	
 		TQByteArray ba(2048);
 	
+		if (!shouldblock) {
+			if ((!TQSocket::canReadLine()) || (state() != TQSocket::Connected)) {
+				return 0;
+			}
+		}
+
 		len = 0;
 		while (1) {
-			tqApp->processEvents();
+			if (shouldblock) {
+				SAFELY_PROCESS_EVENTS
+			}
 			if (state() != TQSocket::Connected) {
 				m_criticalSection--;
 				return -1;
@@ -435,7 +469,13 @@ int TDEKerberosServerSocket::getSASLDataFromNetwork(char *buf, int trunclen) {
 				}
 			}
 			else {
-				usleep(1000);
+				if (shouldblock) {
+					
+					usleep(1000);
+				}
+				else {
+					break;
+				}
 			}
 			if (len >= (ba.size()-1)) {
 				ba.resize(ba.size()+2048);
@@ -486,21 +526,21 @@ int TDEKerberosServerSocket::transmitEncryptedData(int fd, const char* readbuf,
 		data_remaining = data_remaining - data_to_write_len;
 		remnant_position = remnant_position + data_to_write_len;
 		if (data_remaining > 0) {
-			tqApp->processEvents();
+			SAFELY_PROCESS_EVENTS
 		}
 	}
 
 	return 0;
 }
 
-int TDEKerberosServerSocket::receiveEncryptedData(char *buf, unsigned int trunclen) {
+int TDEKerberosServerSocket::receiveEncryptedData(char *buf, unsigned int trunclen, bool shouldblock) {
 	unsigned int recv_len;
 	const char *recv_data;
 	int result;
 	int len;
 
 	char *encbuf = (char*)malloc(m_negotiatedMaxBufferSize);
-	len = getSASLDataFromNetwork(encbuf, m_negotiatedMaxBufferSize);
+	len = getSASLDataFromNetwork(encbuf, m_negotiatedMaxBufferSize, shouldblock);
 	if (len < 0) {
 		return -1;
 	}
diff --git a/lib/libtdekrb/src/tdekrbserversocket.h b/lib/libtdekrb/src/tdekrbserversocket.h
index 0d71faf..80c84fd 100644
--- a/lib/libtdekrb/src/tdekrbserversocket.h
+++ b/lib/libtdekrb/src/tdekrbserversocket.h
@@ -58,9 +58,9 @@ class TDEKerberosServerSocket : public TQSocket
 		int initializeKerberosInterface();
 		void freeKerberosConnection();
 		void sendSASLDataToNetwork(const char *buffer, unsigned length, int netfd);
-		int getSASLDataFromNetwork(char *buf, int trunclen);
+		int getSASLDataFromNetwork(char *buf, int trunclen, bool shouldblock=true);
 		int transmitEncryptedData(int fd, const char* readbuf, int cc);
-		int receiveEncryptedData(char *buf, unsigned int trunclen);
+		int receiveEncryptedData(char *buf, unsigned int trunclen, bool shouldblock=true);
 
 	protected:
 		TQString m_authenticatedUserName;
@@ -73,6 +73,7 @@ class TDEKerberosServerSocket : public TQSocket
 		int m_criticalSection;
 		TQBuffer* m_buffer;
 		long m_bufferLength;
+		bool* m_canary;
 
 	private:
 		SASLDataPrivate *saslData;