LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
SOCKET Accept;
LPSOCKET_INFORMATION SocketInfo;
DWORD RecvBytes, SendBytes;
DWORD Flags;
if (uMsg == WM_SOCKET)
{
if (WSAGETSELECTERROR(lParam))
{
printf("Socket failed with error %d\n", WSAGETSELECTERROR(lParam));
FreeSocketInformation(wParam);
}
else
{
switch(WSAGETSELECTEVENT(lParam))
{
case FD_ACCEPT:
if ((Accept = accept(wParam, NULL, NULL)) == INVALID_SOCKET)
{
printf("accept() failed with error %d\n", WSAGetLastError());
break;
}
// Create a socket information structure to associate with the
// socket for processing I/O.
CreateSocketInformation(Accept);
printf("Socket number %d connected\n", Accept);
WSAAsyncSelect(Accept, hwnd, WM_SOCKET, FD_READ|FD_WRITE|FD_CLOSE);
break;
case FD_READ:
SocketInfo = GetSocketInformation(wParam);
// Read data only if the receive buffer is empty.
if (SocketInfo->BytesRECV != 0)
{
SocketInfo->RecvPosted = TRUE;
return 0;
}
else
{
SocketInfo->DataBuf.buf = SocketInfo->Buffer;
SocketInfo->DataBuf.len = DATA_BUFSIZE;
Flags = 0;
if (WSARecv(SocketInfo->Socket, &(SocketInfo->DataBuf), 1, &RecvBytes,
&Flags, NULL, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != WSAEWOULDBLOCK)
{
printf("WSARecv() failed with error %d\n", WSAGetLastError());
FreeSocketInformation(wParam);
return 0;
}
}
else // No error so update the byte count
{
SocketInfo->BytesRECV = RecvBytes;
}
}
// DO NOT BREAK HERE SINCE WE GOT A SUCCESSFUL RECV. Go ahead
// and begin writing data to the client.
case FD_WRITE:
SocketInfo = GetSocketInformation(wParam);
if (SocketInfo->BytesRECV > SocketInfo->BytesSEND)
{
SocketInfo->DataBuf.buf = SocketInfo->Buffer + SocketInfo->BytesSEND;
SocketInfo->DataBuf.len = SocketInfo->BytesRECV - SocketInfo->BytesSEND;
if (WSASend(SocketInfo->Socket, &(SocketInfo->DataBuf), 1, &SendBytes, 0,
NULL, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != WSAEWOULDBLOCK)
{
printf("WSASend() failed with error %d\n", WSAGetLastError());
FreeSocketInformation(wParam);
return 0;
}
}
else // No error so update the byte count
{
SocketInfo->BytesSEND += SendBytes;
}
}
if (SocketInfo->BytesSEND == SocketInfo->BytesRECV)
{
SocketInfo->BytesSEND = 0;
SocketInfo->BytesRECV = 0;
// If a RECV occurred during our SENDs then we need to post an FD_READ
// notification on the socket.
if (SocketInfo->RecvPosted == TRUE)
{
SocketInfo->RecvPosted = FALSE;
PostMessage(hwnd, WM_SOCKET, wParam, FD_READ);
}
}
break;
case FD_CLOSE:
printf("Closing socket %d\n", wParam);
FreeSocketInformation(wParam);
break;
}
}
return 0;
}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam) {
SOCKET sd;
LPSOCKET_INFORMATION SocketInfo;
DWORD RecvBytes, SendBytes;
DWORD Flags;
switch (Message) {
case WM_CREATE:
createElements(hwnd);
break;
case WM_SOCKET:
if (WSAGETSELECTERROR(lParam)) {
printf("Socket failed with error %d\n", WSAGETSELECTERROR(lParam));
FreeSocketInformation(wParam);
} else {
switch (WSAGETSELECTEVENT(lParam)) {
case FD_CONNECT:
break;
case FD_ACCEPT:
if ((sd = accept(wParam, NULL, NULL)) == INVALID_SOCKET) {
break;
}
CreateSocketInformation(sd);
WSAAsyncSelect(sd, hwnd, WM_SOCKET, FD_READ | FD_CLOSE);
break;
case FD_READ:
SocketInfo = GetSocketInformation(wParam);
// Read data only if the receive buffer is empty.
if (SocketInfo->BytesRECV != 0) {
SocketInfo->RecvPosted = TRUE;
return 0;
} else {
SocketInfo->DataBuf.buf = SocketInfo->Buffer;
SocketInfo->DataBuf.len = DATA_BUFSIZE;
Flags = 0;
if (WSARecv(SocketInfo->Socket, &(SocketInfo->DataBuf), 1, &RecvBytes,
&Flags, NULL, NULL) == SOCKET_ERROR) {
if (WSAGetLastError() != WSAEWOULDBLOCK) {
printf("WSARecv() failed with error %d\n", WSAGetLastError());
FreeSocketInformation(wParam);
return 0;
}
} else { // No error so update the byte count
SocketInfo->BytesRECV = RecvBytes;
}
break;
}
break;
case FD_WRITE:
SocketInfo = GetSocketInformation(wParam);
if (SocketInfo->BytesRECV > SocketInfo->BytesSEND) {
SocketInfo->DataBuf.buf = SocketInfo->Buffer + SocketInfo->BytesSEND;
SocketInfo->DataBuf.len = SocketInfo->BytesRECV - SocketInfo->BytesSEND;
if (WSASend(SocketInfo->Socket, &(SocketInfo->DataBuf), 1, &SendBytes, 0,
NULL, NULL) == SOCKET_ERROR) {
if (WSAGetLastError() != WSAEWOULDBLOCK) {
printf("WSASend() failed with error %d\n", WSAGetLastError());
FreeSocketInformation(wParam);
return 0;
}
}
else { // No error so update the byte count
SocketInfo->BytesSEND += SendBytes;
}
}
if (SocketInfo->BytesSEND == SocketInfo->BytesRECV) {
SocketInfo->BytesSEND = 0;
SocketInfo->BytesRECV = 0;
// If a RECV occurred during our SENDs then we need to post an FD_READ
// notification on the socket.
if (SocketInfo->RecvPosted == TRUE) {
SocketInfo->RecvPosted = FALSE;
PostMessage(hwnd, WM_SOCKET, wParam, FD_READ);
}
}
break;
case FD_CLOSE:
printf("Closing socket %d\n", wParam);
FreeSocketInformation(wParam);
break;
}
}
break;
case WM_DESTROY: // Terminate program
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd, Message, wParam, lParam);
}
return 0;
}
