/**program description:
 *
 * this is a simple port scanner
 * based on TCP connection. You
 * should insert IP and starting
 * port as well as ending port.
 * IPv4 is accepted only. Works 
 * on Windows OS
 *
 * exercise: do input validation
 *
 * Author: X-Shab
 * Copyright 2008 - 2009
 *
 */
 
#include<iostream>
#include<string>
#include<sstream>
#include<Ws2tcpip.h>            //used instead of "Winsock2.h"
using namespace std;
 
struct addrinfo hints;      	//input connection type and ip type 
struct addrinfo *fullInfo;	//holds full address information of the target host
string ip;
string port;
 
void initiateWinsockFacility()
{
    WORD wVersionRequested;
    WSADATA wsaData;
    int error;
 
    wVersionRequested = MAKEWORD(2, 2);
 
    error = WSAStartup(wVersionRequested, &wsaData);
 
    if (error != 0) 
    {
        cout<<"WSAStartup failed with error: "<<error<<endl;
 
	system("pause");
        exit(-1);
    }
}
 
//get full information about the connection to be made - fullInfo carries the output
void getFullAddressInformation(const char *ipAddress, const char *portNumber)
{
	int status = getaddrinfo(ipAddress, portNumber, &hints, &fullInfo);
 
	if(status != 0)
	{
		cout<<"getaddrinfo() error: "<< gai_strerror(status) <<endl;
		WSACleanup();
		exit(-1);
	}
}
 
string convertIntToString(int number)
{
	string stringOutput;
 
	stringstream ss;
	ss << number;
	ss >> stringOutput;
 
	return stringOutput;
}
 
int convertStringToInt(string stringStream)
{
	int integerOutput;
 
	stringstream ss;
	ss << stringStream;
	ss >> integerOutput;
 
	return integerOutput;
}
 
int convertConstCharToInt(const char *characters)
{
	int integerOutput;
	string stringFromConstChar(characters);
 
	stringstream ss;
	ss << stringFromConstChar;
	ss >> integerOutput;
 
	return integerOutput;
}
 
int main()
{
	initiateWinsockFacility();
 
	int endingPort;
	int socketFileDescriptor;
 
	system("cls");
 
	memset(&hints, 0, sizeof(hints));
 
	hints.ai_family = AF_INET;
	hints.ai_socktype = SOCK_STREAM;
 
	cout<<"Please enter your target IP: ";
	cin>>ip;
 
	cout<<"Enter Starting Port: ";
	cin>>port;
 
	cout<<"Enter Ending Port: ";
	cin>>endingPort;
 
	cout<<"Start Checking for Open Ports: "<<endl;
 
	int incrementingPort = convertStringToInt(port);
 
	while(incrementingPort <= endingPort)
	{
		getFullAddressInformation(ip.c_str(), port.c_str());
 
		socketFileDescriptor = socket(fullInfo->ai_family, fullInfo->ai_socktype, fullInfo->ai_protocol);
 
		if(socketFileDescriptor == INVALID_SOCKET )
		{
			cout<<"Error: failed to create a socket.\n";
 
			freeaddrinfo(fullInfo);
			WSACleanup();
 
			system("pause");
			exit(-1);
		}
 
		int connectStatus = connect(socketFileDescriptor, fullInfo->ai_addr, fullInfo->ai_addrlen);
 
		if(connectStatus == SOCKET_ERROR)
		{
			//check type of error you get
			if(WSAGetLastError() == 10060)
			{
				cout<<"Connection Timed Out - Please check your IP"<<endl;
 
				closesocket(socketFileDescriptor);
				freeaddrinfo(fullInfo);
				WSACleanup();
 
				system("pause");
				exit(-1);
			}
 
			cout<<"Port No. "<< port <<" is Closed"<<endl;
 
		}else{
			cout<<"Port No. "<< port <<" is Open"<<endl;
		}
 
		closesocket(socketFileDescriptor);
		freeaddrinfo(fullInfo);
 
		incrementingPort++;
 
		port = convertIntToString(incrementingPort);
	}
 
	/**not needed since its been implemented
	 * on the last loop above
	 *
	 * closesocket(socketFileDescriptor);
	 * freeaddrinfo(fullInfo);
	 *
	 */
 
        WSACleanup();
	system("pause");
 
	return 0;
}