Basically I have a header file like this:
#if WIN32
typedef DWORD (WSAAPI *SocketStartup) (WORD wVersionRequested, LPWSADATA lpWSAData);
typedef SOCKET (WINAPI *MakeSocket)(IN int af, IN int type, IN int protocol, IN LPWSAPROTOCOL_INFOW lpProtocolInfo, IN GROUP g, IN DWORD dwFlags );
typedef DWORD (WINAPI *SocketSendFunc) (IN SOCKET s,__in_bcount(len) const char FAR * buf, IN int len,IN int flags);
typedef DWORD (WINAPI *GetLastSocketErrorFunc)();
typedef DWORD (WINAPI *ShutdownSocketFunc)(SOCKET hSocket, int how);
typedef DWORD (WINAPI *CloseSocketFunc)(SOCKET hSocket);
#endif
and then I do something like this:
SocketStartup* start = (SocketStartup*)GetProcAddress(socketLib,"WSAStartup");
getLastSocketError = (GetLastSocketErrorFunc*)GetProcAddress(socketLib,"WSAGetLastError");
closeSocket = (CloseSocketFunc*)GetProcAddress(socketLib,"closesocket");
shutdownSocket = (ShutdownSocketFunc*) GetProcAddress(socketLib,"shutdown");
socketSend = (SocketSendFunc*) GetProcAddress(socketLib, "send");
if(start == 0 || getLastSocketError == 0 || closeSocket == 0 || shutdownSocket == 0
|| socketSend == 0)
{
printf("[!] Failed to find entry points in Ws2_32.dll. Error Code: %d\n", GetLastError());
CloseLibraries();
ErrorExit();
}
WSADATA wsdata;
//ZeroMemory(&wsdata,sizeof(wsdata));
printf("error: %d\n", GetLastError());
WORD test = MAKEWORD(1,1);
int result = (*start)(test, &wsdata);
return result == 0;
However, when I call this function (the line with (*start)(test, &wsdata)) I get this error message:
Unhandled exception at 0x7868146a in sockets.exe: 0xC0000005: Access violation.
I tried changing the calling convention (__cdecl, WINAPI, WSAAPI) but it always ends with the same error message.