#include <winsock2.h>
#include <windows.h>

typedef int	(*PFNWSASTARTUP)(WORD, LPWSADATA);
typedef SOCKET  (*PFNSOCKET)(int, int, int);
typedef int	(*PFNCLOSESOCKET)(SOCKET);
typedef int	(*PFNBIND)(SOCKET, const SOCKADDR*, int);
typedef int     (*PFNLISTEN)(SOCKET, int);
typedef SOCKET  (*PFNACCEPT)(SOCKET, SOCKADDR*, int*);
typedef int	(*PFNSEND)(SOCKET, const char*, int, int);
typedef int	(*PFNRECV)(SOCKET, char*, int, int);
typedef u_short (*PFNHTONS)(u_short);
typedef u_long  (*PFNHTONL)(u_long);
typedef int	(*PFNWSAGETLASTERROR)(void);

static PFNWSASTARTUP      pfnWSAStartup   = 0;
static PFNSOCKET          pfnSocket       = 0;
static PFNCLOSESOCKET     pfnCloseSocket  = 0;
static PFNBIND		  pfnBind	  = 0;
static PFNLISTEN	  pfnListen	  = 0;
static PFNACCEPT	  pfnAccept	  = 0;
static PFNSEND		  pfnSend         = 0;
static PFNRECV		  pfnRecv         = 0;
static PFNHTONS	          pfnHtons	  = 0;
static PFNHTONL		  pfnHtonl        = 0;
static PFNWSAGETLASTERROR pfnGetLastError = 0;

int __cdecl WinMainCRTStartup() {

	HMODULE hWinSock = LoadLibrary(L"Ws2_32.dll");
	if(!hWinSock) return 1;

	pfnWSAStartup   =
reinterpret_cast<PFNWSASTARTUP>(GetProcAddress(hWinSock,"WSAStartup"));
	pfnSocket       = reinterpret_cast<PFNSOCKET>(GetProcAddress(hWinSock, "socket"));
	pfnCloseSocket  = reinterpret_cast<PFNCLOSESOCKET>(GetProcAddress(hWinSock, "closesocket"));
	pfnBind	        = reinterpret_cast<PFNBIND>(GetProcAddress(hWinSock, "bind"));
	pfnListen	    = reinterpret_cast<PFNLISTEN>(GetProcAddress(hWinSock, "listen"));
	pfnAccept       = reinterpret_cast<PFNACCEPT>(GetProcAddress(hWinSock, "accept"));
	pfnSend		    = reinterpret_cast<PFNSEND>(GetProcAddress(hWinSock, "send"));
	pfnRecv		    = reinterpret_cast<PFNRECV>(GetProcAddress(hWinSock, "recv"));
	pfnHtons	    = reinterpret_cast<PFNHTONS>(GetProcAddress(hWinSock, "htons"));
	pfnHtonl	    = reinterpret_cast<PFNHTONL>(GetProcAddress(hWinSock, "htonl"));
	pfnGetLastError = reinterpret_cast<PFNWSAGETLASTERROR>(GetProcAddress(hWinSock, "WSAGetLastError"));

	WSAData sData;
	if(pfnWSAStartup(MAKEWORD(2, 2), &sData)) return 1;

	SOCKET iListenSocket = pfnSocket(AF_INET,
					 SOCK_STREAM,
					 IPPROTO_TCP);

	if(iListenSocket == INVALID_SOCKET) return 1;

	SOCKADDR_IN sSockAddr;
	sSockAddr.sin_addr.s_addr = INADDR_ANY;
	sSockAddr.sin_family	  = AF_INET;
	sSockAddr.sin_port	  = pfnHtons(12532);

	if(pfnBind(iListenSocket,
		   reinterpret_cast<SOCKADDR*>(&sSockAddr),
		   sizeof(sSockAddr)) == SOCKET_ERROR) return 1;

	int iLength = sizeof(sSockAddr);

	MSG msg;
	while(GetMessage(&msg, 0, 0, 0)) {

		if(pfnListen(iListenSocket, 0) == SOCKET_ERROR) return 1;

		SOCKET iAcceptSocket = pfnAccept(iListenSocket,
			                   nterpret_cast<SOCKADDR*>(&sSockAddr),
						 &iLength);

		if(iAcceptSocket == INVALID_SOCKET) return 1;

		pfnCloseSocket(iAcceptSocket);

		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	pfnCloseSocket(iListenSocket);

	FreeLibrary(hWinSock);

	return 0;
}

Alles klappt wunderbar nur der bind Funktionsaufruf schlägt fehl mit dem Errorcode WSAENOTSOCK... Irgendjemand eine Idee? Wenn ich die Portangabe weglasse klappt der bind Aufruf. Hab absolut keine Idee an was das liegen könnte.
Tut mir leid wegen der grottigen Formatierung, kriegs einfach net besser hin.

Es lag an der Aufrufkonvention der Funktionen. Ein einfaches _stdcall bei den Funktionspointern und es funktioniert so wie es soll.

kleines bsp.

typedef int (*PFNBIND)(SOCKET, const sockaddr*, int);

->

typedef int (_stdcall *PFNBIND)(SOCKET, const sockaddr*, int);