src/arch/win32/win32socketinterf.cpp - 4diac/org.eclipse.4diac.forte - Git at Google

 /*******************************************************************************
  * Copyright (c) 2010, 2021 ACIN, Profactor GmbH, AIT, fortiss GmbH, OFFIS e.V., HIT robot group
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
  * http://www.eclipse.org/legal/epl-2.0.
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *   Alois Zoitl, Ingo Hegny, Gerhard Ebenhofer, Thomas Strasser
  *     - initial API and implementation and/or initial documentation
  *  Jörg Walter - Windows XP compatibility
  *  Zhao Xin - fix socket resource leakage
  *******************************************************************************/

 #include <sockhand.h>      //needs to be first pulls in the platform specific includes
 #include "win32socketinterf.h"
 #include "devlog.h"
 #include <string.h>

 void CWin32SocketInterface::closeSocket(TSocketDescriptor pa_nSockD){
   closesocket(pa_nSockD);
 }

 CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openTCPServerConnection(char *pa_acIPAddr, unsigned short pa_nPort){
   TSocketDescriptor nRetVal = INVALID_SOCKET;

   DEVLOG_INFO("CWin32SocketInterface: Opening TCP-Server connection at: %s:%d\n", pa_acIPAddr, pa_nPort);

   TSocketDescriptor nSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

   if(INVALID_SOCKET != nSocket){
     struct sockaddr_in stSockAddr = { };
     stSockAddr.sin_family = AF_INET;
     stSockAddr.sin_port = htons(pa_nPort);
     stSockAddr.sin_addr.s_addr = htonl(INADDR_ANY);

     int nOptVal = 1;
     if(SOCKET_ERROR == setsockopt(nSocket, SOL_SOCKET, SO_REUSEADDR, (char*) &nOptVal, sizeof(nOptVal))) {
       LPSTR pacErrorMessage = getErrorMessage(WSAGetLastError());
       DEVLOG_ERROR("CWin32SocketInterface: could not set socket option SO_REUSEADDR:  %s\n", pacErrorMessage);
       LocalFree(pacErrorMessage);
     }

     if(0 == bind(nSocket, (struct sockaddr *) &stSockAddr, sizeof(struct sockaddr))){
       if(SOCKET_ERROR == listen(nSocket, 1)) { // for the classic IEC 61499 server only one connection at the same time is accepted TODO mayb make this adjustable for future extensions
         int nLastError = WSAGetLastError();
         LPSTR pacErrorMessage = getErrorMessage(nLastError);
         DEVLOG_ERROR("CWin32SocketInterface: listen() failed: %d - %s\n", nLastError, pacErrorMessage);
         LocalFree(pacErrorMessage);
       }
       else{
         nRetVal = nSocket;
       }
     }
     else{
       int nLastError = WSAGetLastError();
       LPSTR pacErrorMessage = getErrorMessage(nLastError);
       DEVLOG_ERROR("CWin32SocketInterface: bind() failed: %d - %s\n", nLastError, pacErrorMessage);
       LocalFree(pacErrorMessage);
     }
   }
   else{
     int nLastError = WSAGetLastError();
     LPSTR pacErrorMessage = getErrorMessage(nLastError);
     DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
     LocalFree(pacErrorMessage);
   }
   return nRetVal;
 }

 CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openTCPClientConnection(char *pa_acIPAddr, unsigned short pa_nPort){
   TSocketDescriptor nRetVal = INVALID_SOCKET;
   TSocketDescriptor nSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

   DEVLOG_INFO("CWin32SocketInterface: Opening TCP-Client connection at: %s:%d\n", pa_acIPAddr, pa_nPort);

   if(INVALID_SOCKET != nSocket) {
     sockaddr_in stSockAddr = {};
     int stSockAddrSz = sizeof(stSockAddr);
     if(WSAStringToAddressA(pa_acIPAddr, AF_INET, NULL, (LPSOCKADDR)&stSockAddr, &stSockAddrSz)) {
       DEVLOG_ERROR("CWin32SocketInterface: WSAStringToAddressA() failed: %d - %s\n", stSockAddr.sin_addr.s_addr, pa_acIPAddr);
     }
     stSockAddr.sin_family = AF_INET;
     stSockAddr.sin_port = htons(pa_nPort);

     if(SOCKET_ERROR == connect(nSocket, (struct sockaddr*) &stSockAddr, sizeof(struct sockaddr))) {
       int nLastError = WSAGetLastError();
       LPSTR pacErrorMessage = getErrorMessage(nLastError);
       DEVLOG_ERROR("CWin32SocketInterface: connect() failed: %d - %s\n", nLastError, pacErrorMessage);
       LocalFree(pacErrorMessage);
       closeSocket(nSocket);
     }
     else{
       nRetVal = nSocket;
     }
   }
   else{
     int nLastError = WSAGetLastError();
     LPSTR pacErrorMessage = getErrorMessage(nLastError);
     DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
     LocalFree(pacErrorMessage);
   }
   return nRetVal;
 }

 CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::acceptTCPConnection(TSocketDescriptor pa_nListeningSockD){
   struct sockaddr client_addr;
   int sin_size = sizeof(struct sockaddr);
   TSocketDescriptor nRetVal = accept(pa_nListeningSockD, &client_addr, &sin_size);

   if(INVALID_SOCKET == nRetVal){
     int nLastError = WSAGetLastError();
     LPSTR pacErrorMessage = getErrorMessage(nLastError);
     DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
     LocalFree(pacErrorMessage);
   }
   return nRetVal;
 }

 int CWin32SocketInterface::sendDataOnTCP(TSocketDescriptor pa_nSockD, char* pa_pcData, unsigned int pa_unSize){
   // This function sends all data in the buffer before it returns!
   int nToSend = pa_unSize;
   int nRetVal = 0;

   while(0 < nToSend){
     //TODO: check if open connection (socket might be closed by peer)
     nRetVal = static_cast<int>(send(pa_nSockD, pa_pcData, nToSend, 0));
     if(nRetVal <= 0){
       LPSTR pacErrorMessage = getErrorMessage(WSAGetLastError());
       DEVLOG_ERROR("TCP-Socket Send failed: %s\n", pacErrorMessage);
       LocalFree(pacErrorMessage);
       break;
     }
     nToSend -= nRetVal;
     pa_pcData += nRetVal;
   }
   return nRetVal;
 }

 int CWin32SocketInterface::receiveDataFromTCP(TSocketDescriptor pa_nSockD, char* pa_pcData, unsigned int pa_unBufSize){
   int nRetVal;
   do{
     nRetVal = recv(pa_nSockD, pa_pcData, pa_unBufSize, 0);
   } while((SOCKET_ERROR == nRetVal) && (WSAEINTR == h_errno)); // recv got interrupt / recieving again
   if(SOCKET_ERROR == nRetVal) {
     int nLastError = WSAGetLastError();
     LPSTR pacErrorMessage = getErrorMessage(nLastError);
     DEVLOG_ERROR("CWin32SocketInterface: TCP-Socket recv() failed: %d - %s\n", nLastError, pacErrorMessage);
     LocalFree(pacErrorMessage);
     if(WSAECONNRESET == nLastError){
       nRetVal = 0; //inform higher levels that the peer closed connection
     }
   }
   return nRetVal;
 }

 CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openUDPSendPort(char *pa_acIPAddr, unsigned short pa_nPort, TUDPDestAddr *m_ptDestAddr){
   DEVLOG_INFO("CWin32SocketInterface: Opening UDP sending connection at: %s:%d\n", pa_acIPAddr, pa_nPort);
   TSocketDescriptor nRetVal = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

   if(INVALID_SOCKET != nRetVal) {
     *m_ptDestAddr = TUDPDestAddr();
     int m_ptDestAddrSz = sizeof(*m_ptDestAddr);
     if(WSAStringToAddressA(pa_acIPAddr, AF_INET, NULL, (LPSOCKADDR)m_ptDestAddr, &m_ptDestAddrSz)) {
       DEVLOG_ERROR("CWin32SocketInterface: WSAStringToAddressA() failed: %d - %s\n", m_ptDestAddr->sin_addr.s_addr, pa_acIPAddr);
     }
     m_ptDestAddr->sin_family = AF_INET;
     m_ptDestAddr->sin_port = htons(pa_nPort);
  }
   else{
     int nLastError = WSAGetLastError();
     LPSTR pacErrorMessage = getErrorMessage(nLastError);
     DEVLOG_ERROR("CWin32SocketInterface: UDP-Socket socket() failed: %d - %s\n", nLastError, pacErrorMessage);
     LocalFree(pacErrorMessage);
   }
   return nRetVal;
 }

 CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openUDPReceivePort(char *pa_acIPAddr, unsigned short pa_nPort){
   DEVLOG_INFO("CWin32SocketInterface: Opening UDP receiving connection at: %s:%d\n", pa_acIPAddr, pa_nPort);
   TSocketDescriptor nRetVal = INVALID_SOCKET;
   TSocketDescriptor nSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

   if(INVALID_SOCKET != nSocket) {
     int nReuseAddrVal = 1;
     if(0 <= setsockopt(nSocket, SOL_SOCKET, SO_REUSEADDR, (char *) &nReuseAddrVal, sizeof(nReuseAddrVal))){
       struct sockaddr_in stSockAddr = {};
       stSockAddr.sin_family = AF_INET;
       stSockAddr.sin_port = htons(pa_nPort);
       stSockAddr.sin_addr.s_addr = htonl(INADDR_ANY);
       if(0 == bind(nSocket, (struct sockaddr *) &stSockAddr, sizeof(struct sockaddr))){
         // setting up multicast group
         sockaddr_in stMCastAddr = {};
         int stMCastAddrSz = sizeof(stMCastAddr);
         if(WSAStringToAddressA(pa_acIPAddr, AF_INET, NULL, (LPSOCKADDR)&stMCastAddr, &stMCastAddrSz)) {
           DEVLOG_ERROR("CWin32SocketInterface: WSAStringToAddressA() failed: %d - %s\n", stMCastAddr.sin_addr.s_addr, pa_acIPAddr);
         }

         struct ip_mreq stMReq = {};
         stMReq.imr_multiaddr = stMCastAddr.sin_addr;
         stMReq.imr_interface.s_addr = htonl(INADDR_ANY);
         setsockopt(nSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*) &stMReq, sizeof(stMReq));
         //if this fails we may have given a non multicasting addr. For now we accept this. May need to be changed in the future.

         nRetVal = nSocket;
       }
       else{
         int nLastError = WSAGetLastError();
             LPSTR pacErrorMessage = getErrorMessage(nLastError);
         DEVLOG_ERROR("CWin32SocketInterface: bind() failed: %d - %s\n", nLastError,pacErrorMessage);
         LocalFree(pacErrorMessage);
       }
     }
     else{
       int nLastError = WSAGetLastError();
           LPSTR pacErrorMessage = getErrorMessage(nLastError);
       DEVLOG_ERROR("CWin32SocketInterface: setsockopt(SO_REUSEADDR) failed: %d - %s\n", nLastError, pacErrorMessage);
       LocalFree(pacErrorMessage);
     }
   }
   else{
     int nLastError = WSAGetLastError();
         LPSTR pacErrorMessage = getErrorMessage(nLastError);
     DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
     LocalFree(pacErrorMessage);
   }
   return nRetVal;
 }

 int CWin32SocketInterface::sendDataOnUDP(TSocketDescriptor pa_nSockD, TUDPDestAddr *pa_ptDestAddr, char* pa_pcData, unsigned int pa_unSize){
   // This function sends all data in the buffer before it returns!
   int nToSend = pa_unSize;
   int nRetVal = 0;

   while(0 < nToSend){
     //TODO: check if open connection (socket might be closed by peer)
     nRetVal = static_cast<int>(sendto(pa_nSockD, pa_pcData, nToSend, 0, (struct sockaddr *) pa_ptDestAddr, sizeof(struct sockaddr)));
     if(nRetVal <= 0){
       int nLastError = WSAGetLastError();
       LPSTR pacErrorMessage = getErrorMessage(nLastError);
       DEVLOG_ERROR("CWin32SocketInterface: UDP-Socket Send failed: %d - %s\n", nLastError, pacErrorMessage);
       LocalFree(pacErrorMessage);
       break;
     }
     nToSend -= nRetVal;
     pa_pcData += nRetVal;
   }
   return nRetVal;
 }

 int CWin32SocketInterface::receiveDataFromUDP(TSocketDescriptor pa_nSockD, char* pa_pcData, unsigned int pa_unBufSize){
   int nRetVal;
   do{
     nRetVal = recvfrom(pa_nSockD, pa_pcData, pa_unBufSize, 0, 0, 0);
   } while((SOCKET_ERROR == nRetVal) && (WSAEINTR == h_errno)); // recv got interrupt / recieving again

   if(SOCKET_ERROR == nRetVal) {
     int nLastError = WSAGetLastError();
     LPSTR pacErrorMessage = getErrorMessage(nLastError);
     DEVLOG_ERROR("CWin32SocketInterface: UDP-Socket recvfrom() failed: %d - %s\n", nLastError, pacErrorMessage);
     LocalFree(pacErrorMessage);
   }
   return nRetVal;
 }

 LPSTR CWin32SocketInterface::getErrorMessage(int pa_nErrorNumber){
   LPSTR pacErrorMessage = NULL;
   FormatMessage(
   FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
   NULL, pa_nErrorNumber, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), pacErrorMessage, 0,
   NULL);
   return pacErrorMessage;
 }
	/*******************************************************************************
	* Copyright (c) 2010, 2021 ACIN, Profactor GmbH, AIT, fortiss GmbH, OFFIS e.V., HIT robot group
	* This program and the accompanying materials are made available under the
	* terms of the Eclipse Public License 2.0 which is available at
	* http://www.eclipse.org/legal/epl-2.0.
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* Alois Zoitl, Ingo Hegny, Gerhard Ebenhofer, Thomas Strasser
	* - initial API and implementation and/or initial documentation
	* Jörg Walter - Windows XP compatibility
	* Zhao Xin - fix socket resource leakage
	*******************************************************************************/

	#include <sockhand.h> //needs to be first pulls in the platform specific includes
	#include "win32socketinterf.h"
	#include "devlog.h"
	#include <string.h>

	void CWin32SocketInterface::closeSocket(TSocketDescriptor pa_nSockD){
	closesocket(pa_nSockD);
	}

	CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openTCPServerConnection(char *pa_acIPAddr, unsigned short pa_nPort){
	TSocketDescriptor nRetVal = INVALID_SOCKET;

	DEVLOG_INFO("CWin32SocketInterface: Opening TCP-Server connection at: %s:%d\n", pa_acIPAddr, pa_nPort);

	TSocketDescriptor nSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

	if(INVALID_SOCKET != nSocket){
	struct sockaddr_in stSockAddr = { };
	stSockAddr.sin_family = AF_INET;
	stSockAddr.sin_port = htons(pa_nPort);
	stSockAddr.sin_addr.s_addr = htonl(INADDR_ANY);

	int nOptVal = 1;
	if(SOCKET_ERROR == setsockopt(nSocket, SOL_SOCKET, SO_REUSEADDR, (char*) &nOptVal, sizeof(nOptVal))) {
	LPSTR pacErrorMessage = getErrorMessage(WSAGetLastError());
	DEVLOG_ERROR("CWin32SocketInterface: could not set socket option SO_REUSEADDR: %s\n", pacErrorMessage);
	LocalFree(pacErrorMessage);
	}

	if(0 == bind(nSocket, (struct sockaddr *) &stSockAddr, sizeof(struct sockaddr))){
	if(SOCKET_ERROR == listen(nSocket, 1)) { // for the classic IEC 61499 server only one connection at the same time is accepted TODO mayb make this adjustable for future extensions
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: listen() failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	else{
	nRetVal = nSocket;
	}
	}
	else{
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: bind() failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	}
	else{
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	return nRetVal;
	}

	CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openTCPClientConnection(char *pa_acIPAddr, unsigned short pa_nPort){
	TSocketDescriptor nRetVal = INVALID_SOCKET;
	TSocketDescriptor nSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

	DEVLOG_INFO("CWin32SocketInterface: Opening TCP-Client connection at: %s:%d\n", pa_acIPAddr, pa_nPort);

	if(INVALID_SOCKET != nSocket) {
	sockaddr_in stSockAddr = {};
	int stSockAddrSz = sizeof(stSockAddr);
	if(WSAStringToAddressA(pa_acIPAddr, AF_INET, NULL, (LPSOCKADDR)&stSockAddr, &stSockAddrSz)) {
	DEVLOG_ERROR("CWin32SocketInterface: WSAStringToAddressA() failed: %d - %s\n", stSockAddr.sin_addr.s_addr, pa_acIPAddr);
	}
	stSockAddr.sin_family = AF_INET;
	stSockAddr.sin_port = htons(pa_nPort);

	if(SOCKET_ERROR == connect(nSocket, (struct sockaddr*) &stSockAddr, sizeof(struct sockaddr))) {
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: connect() failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	closeSocket(nSocket);
	}
	else{
	nRetVal = nSocket;
	}
	}
	else{
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	return nRetVal;
	}

	CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::acceptTCPConnection(TSocketDescriptor pa_nListeningSockD){
	struct sockaddr client_addr;
	int sin_size = sizeof(struct sockaddr);
	TSocketDescriptor nRetVal = accept(pa_nListeningSockD, &client_addr, &sin_size);

	if(INVALID_SOCKET == nRetVal){
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	return nRetVal;
	}

	int CWin32SocketInterface::sendDataOnTCP(TSocketDescriptor pa_nSockD, char* pa_pcData, unsigned int pa_unSize){
	// This function sends all data in the buffer before it returns!
	int nToSend = pa_unSize;
	int nRetVal = 0;

	while(0 < nToSend){
	//TODO: check if open connection (socket might be closed by peer)
	nRetVal = static_cast<int>(send(pa_nSockD, pa_pcData, nToSend, 0));
	if(nRetVal <= 0){
	LPSTR pacErrorMessage = getErrorMessage(WSAGetLastError());
	DEVLOG_ERROR("TCP-Socket Send failed: %s\n", pacErrorMessage);
	LocalFree(pacErrorMessage);
	break;
	}
	nToSend -= nRetVal;
	pa_pcData += nRetVal;
	}
	return nRetVal;
	}

	int CWin32SocketInterface::receiveDataFromTCP(TSocketDescriptor pa_nSockD, char* pa_pcData, unsigned int pa_unBufSize){
	int nRetVal;
	do{
	nRetVal = recv(pa_nSockD, pa_pcData, pa_unBufSize, 0);
	} while((SOCKET_ERROR == nRetVal) && (WSAEINTR == h_errno)); // recv got interrupt / recieving again
	if(SOCKET_ERROR == nRetVal) {
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: TCP-Socket recv() failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	if(WSAECONNRESET == nLastError){
	nRetVal = 0; //inform higher levels that the peer closed connection
	}
	}
	return nRetVal;
	}

	CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openUDPSendPort(char pa_acIPAddr, unsigned short pa_nPort, TUDPDestAddr m_ptDestAddr){
	DEVLOG_INFO("CWin32SocketInterface: Opening UDP sending connection at: %s:%d\n", pa_acIPAddr, pa_nPort);
	TSocketDescriptor nRetVal = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

	if(INVALID_SOCKET != nRetVal) {
	*m_ptDestAddr = TUDPDestAddr();
	int m_ptDestAddrSz = sizeof(*m_ptDestAddr);
	if(WSAStringToAddressA(pa_acIPAddr, AF_INET, NULL, (LPSOCKADDR)m_ptDestAddr, &m_ptDestAddrSz)) {
	DEVLOG_ERROR("CWin32SocketInterface: WSAStringToAddressA() failed: %d - %s\n", m_ptDestAddr->sin_addr.s_addr, pa_acIPAddr);
	}
	m_ptDestAddr->sin_family = AF_INET;
	m_ptDestAddr->sin_port = htons(pa_nPort);
	}
	else{
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: UDP-Socket socket() failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	return nRetVal;
	}

	CWin32SocketInterface::TSocketDescriptor CWin32SocketInterface::openUDPReceivePort(char *pa_acIPAddr, unsigned short pa_nPort){
	DEVLOG_INFO("CWin32SocketInterface: Opening UDP receiving connection at: %s:%d\n", pa_acIPAddr, pa_nPort);
	TSocketDescriptor nRetVal = INVALID_SOCKET;
	TSocketDescriptor nSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

	if(INVALID_SOCKET != nSocket) {
	int nReuseAddrVal = 1;
	if(0 <= setsockopt(nSocket, SOL_SOCKET, SO_REUSEADDR, (char *) &nReuseAddrVal, sizeof(nReuseAddrVal))){
	struct sockaddr_in stSockAddr = {};
	stSockAddr.sin_family = AF_INET;
	stSockAddr.sin_port = htons(pa_nPort);
	stSockAddr.sin_addr.s_addr = htonl(INADDR_ANY);
	if(0 == bind(nSocket, (struct sockaddr *) &stSockAddr, sizeof(struct sockaddr))){
	// setting up multicast group
	sockaddr_in stMCastAddr = {};
	int stMCastAddrSz = sizeof(stMCastAddr);
	if(WSAStringToAddressA(pa_acIPAddr, AF_INET, NULL, (LPSOCKADDR)&stMCastAddr, &stMCastAddrSz)) {
	DEVLOG_ERROR("CWin32SocketInterface: WSAStringToAddressA() failed: %d - %s\n", stMCastAddr.sin_addr.s_addr, pa_acIPAddr);
	}

	struct ip_mreq stMReq = {};
	stMReq.imr_multiaddr = stMCastAddr.sin_addr;
	stMReq.imr_interface.s_addr = htonl(INADDR_ANY);
	setsockopt(nSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*) &stMReq, sizeof(stMReq));
	//if this fails we may have given a non multicasting addr. For now we accept this. May need to be changed in the future.

	nRetVal = nSocket;
	}
	else{
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: bind() failed: %d - %s\n", nLastError,pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	}
	else{
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: setsockopt(SO_REUSEADDR) failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	}
	else{
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: Couldn't create socket: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	return nRetVal;
	}

	int CWin32SocketInterface::sendDataOnUDP(TSocketDescriptor pa_nSockD, TUDPDestAddr pa_ptDestAddr, char pa_pcData, unsigned int pa_unSize){
	// This function sends all data in the buffer before it returns!
	int nToSend = pa_unSize;
	int nRetVal = 0;

	while(0 < nToSend){
	//TODO: check if open connection (socket might be closed by peer)
	nRetVal = static_cast<int>(sendto(pa_nSockD, pa_pcData, nToSend, 0, (struct sockaddr *) pa_ptDestAddr, sizeof(struct sockaddr)));
	if(nRetVal <= 0){
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: UDP-Socket Send failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	break;
	}
	nToSend -= nRetVal;
	pa_pcData += nRetVal;
	}
	return nRetVal;
	}

	int CWin32SocketInterface::receiveDataFromUDP(TSocketDescriptor pa_nSockD, char* pa_pcData, unsigned int pa_unBufSize){
	int nRetVal;
	do{
	nRetVal = recvfrom(pa_nSockD, pa_pcData, pa_unBufSize, 0, 0, 0);
	} while((SOCKET_ERROR == nRetVal) && (WSAEINTR == h_errno)); // recv got interrupt / recieving again

	if(SOCKET_ERROR == nRetVal) {
	int nLastError = WSAGetLastError();
	LPSTR pacErrorMessage = getErrorMessage(nLastError);
	DEVLOG_ERROR("CWin32SocketInterface: UDP-Socket recvfrom() failed: %d - %s\n", nLastError, pacErrorMessage);
	LocalFree(pacErrorMessage);
	}
	return nRetVal;
	}

	LPSTR CWin32SocketInterface::getErrorMessage(int pa_nErrorNumber){
	LPSTR pacErrorMessage = NULL;
	FormatMessage(
	FORMAT_MESSAGE_ALLOCATE_BUFFER \| FORMAT_MESSAGE_FROM_SYSTEM \| FORMAT_MESSAGE_IGNORE_INSERTS,
	NULL, pa_nErrorNumber, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), pacErrorMessage, 0,
	NULL);
	return pacErrorMessage;
	}