Multithreaded port scanner written by C #

Program | port Scan | Multithreading Author: She


I was fortunate enough to buy a CD with Visual Studio. NET, and hastily install a set, a very good feeling, learn to write Port scanner one, dedicated to this edition of Friends:
Using System;;
Using System.Drawing;;
using System.Collections;;
Using System.ComponentModel;;
Using System.Windows.Forms;;
Add the following.
using System.Data;;
Using System.Net.Sockets;;
using System.Net;;
Using System.IO;;
using System.Text;;
using System.Threading;;

Namespace Iportscan
{
〈summary〉
Summary description for Form1.
〈/summary〉
public class Form1:System.Windows.Forms.Form
{
This is where the public variables that the program is going to use
public string scanhost = Dns.gethostname ();;//default current native IP
Public Int32 tport = 0;;//Current Connection port number
Public Int32 connstate = 0;;//Scan status
public int portsum = 0;;//Port totals
public bool Endthread = false;;//End State
Public AutoResetEvent Asyncopsaredone = new AutoResetEvent (false);;
Private System.Windows.Forms.Label Label1;;
Private System.Windows.Forms.TextBox txthostname;;
Private System.Windows.Forms.Button CmdExec;;
Private System.Windows.Forms.ListBox loglist;;
public System.Windows.Forms.CheckedListBox portlist;;
Private System.Windows.Forms.Label label2;;
Private System.Windows.Forms.Label label3;;
Private System.Windows.Forms.NumericUpDown snum;;
Private System.Windows.Forms.NumericUpDown eNum;;
Private System.Windows.Forms.CheckBox Showdie;;
Private System.Windows.Forms.Label label4;;
Private System.Windows.Forms.Button button1;;
Private System.Windows.Forms.ToolTip toolTip1;;
Private System.Windows.Forms.StatusBar statusBar1;;
Private System.Windows.Forms.LinkLabel linkLabel1;;
Private System.Windows.Forms.LinkLabel linkLabel2;;
private System.ComponentModel.IContainer components;;
/*
The property settings code for each called control is omitted here
*/
static void Main ()
{
Application.Run (New Form1 ());
}

private void Cmdexec_click (object sender, System.EventArgs e)
{
Int32 Startport = (Int32) snum.value;;
Int32 Endport = (Int32) enum.value;;
if (txthostname.text.length==0)
{
MessageBox.Show ("Please enter the name of a host!") "," System hints ");;
Txthostname.text = Scanhost.tostring ();;
Txthostname.focus ();;
return;;
}
if (Startport〉endport)
{
MessageBox.Show ("error, starting port must be less than end port!", "System Prompt");;
Startport = endPort-1;;
Snum.text = Startport.tostring ();;
Snum.focus ();;
return;;
}

if (cmdexec.text== "&scan")
{
endthread= false;;
cmdexec.text= "&stop";;
}
Else
{
endthread= true;;
cmdexec.text= "&scan";;
}

if (endthread!=true)
{
connstate = 0;;
portsum = 0;;
Scanhost = Txthostname.text;;
Try
{
IPAddress ipaddr = (ipaddress) dns.resolve (scanhost). Addresslist.getvalue (0);;
Txthostname.text = ipaddr. ToString ();;
}
Catch
{
Txthostname.focus ();;
MessageBox.Show ("Please enter the correct host address, this address DNS cannot resolve", "System Prompt");;
return;;
}
LogList.Items.Clear ();;

for (Int32 threadnum = startport;; threadnum〈=endport;; threadnum++)
{
ThreadPool.QueueUserWorkItem (New WaitCallback (Startscan), threadnum);
LOGLIST.ITEMS.ADD ("Scan port:" + threadnum.tostring ());;
}

}
}
public void Startscan (Object state)
{
Int32 port = (Int32) state;;
String tmsg = "";;
String getData = "";;
int lindex = 0;;
int eindex = 0;;
connstate++;//determine Number of threads
if (endthread==true)
{
if (connstate== (Int32) enum.value-(Int32) snum.value))
{
Cmdexec.text = "&scan";;
LOGLIST.ITEMS.ADD ("Scan completed!"); ；
}
Else
{
Cmdexec.text = "&stop";;
LOGLIST.ITEMS.ADD ("Stopping on" +port.) ToString () + "Scan thread for port");;
}
LOGLIST.ITEMS.ADD ("End Thread:" +port.) ToString ());;
Asyncopsaredone.close ();;
}
Else
{
Try
{
TcpClient TCP = new TcpClient ();;
Tcp. Connect (scanhost,port);;
If a connection error is established, the following code will not be executed ...
Portsum + +;;
Lindex = PORTLIST.ITEMS.ADD (port. ToString () + "Port open", false);;
Portlist.selectedindex=lindex;;
Stream sm = tcp. GetStream ();;
Sm. Write (Encoding.Default.GetBytes (Tmsg.tochararray ()), 0,tmsg.length);
StreamReader sr = new StreamReader (TCP. GetStream (), encoding.default);
GetData = Sr. ReadLine ();;
if (lindex!=0&&getdata.length!=0)
{
tmsg = "+-" + port. ToString () + "Port data:" +getdata.tostring ();
Eindex = PortList.Items.Add (tmsg);;//Insert an information record
PortList.Items.Insert (LINDEX+1,TMSG);
PortList.Items.RemoveAt (Eindex);
}
Sr. Close ();;
Sm. Close ();;
Tcp. Close ();;
}
Catch
{
Show necrotic ports
if (Showdie. Checked==true)
{
PORTLIST.ITEMS.ADD (port. ToString () + "Port cannot connect, return data is empty");;
}
}
Finally
{
Thread.Sleep (0);;
LOGLIST.ITEMS.ADD ("End Thread:" +port.) ToString ());;
Asyncopsaredone.close ();;
Statusbar1.text = "Port total:" +portsum.tostring ();;
if (connstate== (Int32) enum.value-(Int32) snum.value))
{
Cmdexec.text = "&scan";;
}
}
}
}

private void Button1_Click (object sender, System.EventArgs e)
{
Application.exit ();;
}