Implemented WSA* calls for Windows.

tcpscanner.cpp

@@ -1,5 +1,6 @@
 #include "tcpscanner.h"
 #include <boost/lexical_cast.hpp>
+#include <iostream>
 
 using namespace std;
 using namespace boost;
@@ -111,12 +112,23 @@ void TcpScanner::initSocket(Service* service)
 	u_long mode = 1;
 	ioctlsocket(sock, FIONBIO, &mode);
 
-	// allocate file descriptor set
+	// set up the OS's choice of signaling for non-blocking sockets
+
+#if Windows
+
+	WSAEVENT evt = WSACreateEvent();
+	WSAEventSelect(sock, evt, FD_WRITE);
+	WSAResetEvent(evt);
+	data->event = evt;
+
+#elif Linux
 
 	data->fdset = new fd_set();
 	FD_ZERO(data->fdset);
 	FD_SET(sock, data->fdset);
 
+#endif
+
 	// start non-blocking connection process
 
 	connect(sock, reinterpret_cast<struct sockaddr*>(info->ai_addr), info->ai_addrlen);
@@ -129,49 +141,57 @@ void TcpScanner::pollSocket(Service* service, bool last)
 		return;
 	}
 
-	TIMEVAL tv = { 0, 0 };
 	auto data = reinterpret_cast<TcpScanData*>(service->data);
 
-	// check if socket is writable, which basically means the connection was successful
+#if Windows
 
-	// for some reason, Linux requires the first parameter to be counterintuitively socket+1, while Windows doesn't
-	// time spent searching for this error: ~1.5 hours
+	// check if the event was signalled
 
-	select(
-		data->socket
-#if Linux
-			+ 1
-#endif
-		, nullptr, data->fdset, nullptr, &tv
-	);
+	auto sigr = WSAWaitForMultipleEvents(1, &data->event, false, 0, false);
+	auto serr = WSAGetLastError();
 
-	// check if the writable flag is set
+	// the return value 258 is not documented in MSDN, however this
+	// is what seems to be returned in case of errors
 
-	auto isOpen = FD_ISSET(data->socket, data->fdset);
+	if (sigr == 258 && serr != WSAEWOULDBLOCK)
+	{
+		service->alive = false;
+		service->reason = AR_IcmpUnreachable;
+	}
+	else if (sigr == 0)
+	{
+		service->alive = true;
+	}
 
-#if Linux
-	if (isOpen)
+#elif Linux
+
+	// check if socket is writable
+
+	TIMEVAL tv = { 0, 0 };
+	select(data->socket + 1, nullptr, data->fdset, nullptr, &tv);
+
+	if (FD_ISSET(data->socket, data->fdset))
 	{
-		// yet again Linux decided to troll me. all select() requests will become "writable", and you have
-		// to check if there was an error or not, to actually determine if the connect() was successful
+		// since it seems writability bit will be set on connection refused errors,
+		// check if this is a legit instance of writable socket or an error
 
 		int serr;
 		socklen_t slen = sizeof(serr);
 		getsockopt(data->socket, SOL_SOCKET, SO_ERROR, &serr, &slen);
-		isOpen = serr == 0;
+
+		service->alive = serr == 0;
 
 		if (serr == ECONNREFUSED)
 		{
 			service->reason = AR_IcmpUnreachable;
 		}
 	}
-#endif
 
-	service->alive = isOpen == 1;
+#endif
 
 	// mark service accordingly
 
-	if (isOpen)
+	if (service->alive)
 	{
 		service->reason = AR_InProgress2;
 		readBanner(service, last);
@@ -185,8 +205,10 @@ void TcpScanner::pollSocket(Service* service, bool last)
 		}
 		else if (service->reason == AR_InProgress)
 		{
+#if Linux
 			FD_ZERO(data->fdset);
 			FD_SET(data->socket, data->fdset);
+#endif
 			return;
 		}
 	}
@@ -197,7 +219,12 @@ void TcpScanner::pollSocket(Service* service, bool last)
 
 	closesocket(data->socket);
 
+#if Windows
+	WSACloseEvent(data->event);
+#elif Linux
 	delete data->fdset;
+#endif
+
 	delete data;
 }
 
@@ -245,7 +272,12 @@ void TcpScanner::readBanner(Service* service, bool last)
 	shutdown(data->socket, SD_BOTH);
 	closesocket(data->socket);
 
+#if Windows
+	WSACloseEvent(data->event);
+#elif Linux
 	delete data->fdset;
+#endif
+
 	delete data;
 }
 

tcpscanner.h

@@ -13,11 +13,22 @@ struct TcpScanData
 	 */
 	SOCKET socket;
 
+#if Windows
+
 	/*!
-	 * File descriptor set for writability.
+	 * Event object to be signalled on connection.
 	 */
+	WSAEVENT event;
+
+#elif Linux
+
+	/*!
+	* File descriptor set to determine writability.
+	*/
 	fd_set* fdset;
 
+#endif
+
 };
 
 /*!