I would like to close an existing connection between to application running on my server. If you have a suggestion please reply on how to program this, you will be appreciated.
Note that: TCPView application can close the connection exactly as I need, but I would like to run it as a console application or other command line.
Really the way it should be done is the application which owns the connected socket should close it, which will happen when the application terminates also.
Finally I found the solution for my request. Cradit to: http://www.csharpfriends.com/Forums/ShowPost.aspx?PostID=20989
The following windows API should be used: //API to get list of connections [DllImport("iphlpapi.dll")] private static extern int GetTcpTable(IntPtr pTcpTable, ref int pdwSize, bool bOrder);
//API to change status of connection [DllImport("iphlpapi.dll")] private static extern int SetTcpEntry(IntPtr pTcprow);
//Convert 16-bit value from network to host byte order [DllImport("wsock32.dll")] private static extern int ntohs(int netshort);
//Convert 16-bit value back again [DllImport("wsock32.dll")] private static extern int htons(int netshort);
using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using System.Runtime.InteropServices;
namespace ConnectionManager
{
class Disconnector
{
}
public class Starter
{
public static void Main(string[] args)
{
if (args.Length == 0)
{
Console.WriteLine("Disconnect IP1 [IP2 [IP3 [IPn]]]");
Console.WriteLine("");
Console.WriteLine("Connections up now:");
string[] cons = Disconnecter.Connections(Disconnecter.State.Established);
foreach (string s in cons)
{
Console.WriteLine(s);
}
}
else
{
foreach (string s in args)
{
Disconnecter.CloseLocalIP(s);
Disconnecter.CloseRemoteIP(s);
}
}
}
}
public class Disconnecter
{
/// <summary>
/// Enumeration of the states
/// </summary>
public enum State
{
/// <summary> All </summary>
All = 0,
/// <summary> Closed </summary>
Closed = 1,
/// <summary> Listen </summary>
Listen = 2,
/// <summary> Syn_Sent </summary>
Syn_Sent = 3,
/// <summary> Syn_Rcvd </summary>
Syn_Rcvd = 4,
/// <summary> Established </summary>
Established = 5,
/// <summary> Fin_Wait1 </summary>
Fin_Wait1 = 6,
/// <summary> Fin_Wait2 </summary>
Fin_Wait2 = 7,
/// <summary> Close_Wait </summary>
Close_Wait = 8,
/// <summary> Closing </summary>
Closing = 9,
/// <summary> Last_Ack </summary>
Last_Ack = 10,
/// <summary> Time_Wait </summary>
Time_Wait = 11,
/// <summary> Delete_TCB </summary>
Delete_TCB = 12
}
/// <summary>
/// Connection info
/// </summary>
private struct MIB_TCPROW
{
public int dwState;
public int dwLocalAddr;
public int dwLocalPort;
public int dwRemoteAddr;
public int dwRemotePort;
}
//API to get list of connections
[DllImport("iphlpapi.dll")]
private static extern int GetTcpTable(IntPtr pTcpTable, ref int pdwSize, bool bOrder);
//API to change status of connection
[DllImport("iphlpapi.dll")]
//private static extern int SetTcpEntry(MIB_TCPROW tcprow);
private static extern int SetTcpEntry(IntPtr pTcprow);
//Convert 16-bit value from network to host byte order
[DllImport("wsock32.dll")]
private static extern int ntohs(int netshort);
//Convert 16-bit value back again
[DllImport("wsock32.dll")]
private static extern int htons(int netshort);
/// <summary>
/// Testexample
/// </summary>
public static void TEST()
{
Console.WriteLine("Not Working Yet!!!");
//string[] ret = Connections(State.All);
//foreach (string con in ret) if (con.IndexOf("192.168.0.101") > -1) System.Diagnostics.Debug.WriteLine(con);
//System.Diagnostics.Debug.WriteLine("----------------------------");
//CloseRemotePort(1863);
//CloseRemotePort(80);
//ret = Connections(State.All);
//foreach (string con in ret) if (con.IndexOf("192.168.0.101") > -1) System.Diagnostics.Debug.WriteLine(con);
}
/// <summary>
/// Close all connection to the remote IP
/// </summary>
/// <param name="IP">IPen på remote PC</param>
public static void CloseRemoteIP(string IP)
{
MIB_TCPROW[] rows = getTcpTable();
for (int i = 0; i < rows.Length; i++)
{
if (rows[i].dwRemoteAddr == IPStringToInt(IP))
{
rows[i].dwState = (int)State.Delete_TCB;
IntPtr ptr = GetPtrToNewObject(rows[i]);
int ret = SetTcpEntry(ptr);
}
}
}
/// <summary>
/// Close all connections at current local IP
/// </summary>
/// <param name="IP"></param>
public static void CloseLocalIP(string IP)
{
MIB_TCPROW[] rows = getTcpTable();
for (int i = 0; i < rows.Length; i++)
{
if (rows[i].dwLocalAddr == IPStringToInt(IP))
{
rows[i].dwState = (int)State.Delete_TCB;
IntPtr ptr = GetPtrToNewObject(rows[i]);
int ret = SetTcpEntry(ptr);
}
}
}
/// <summary>
/// Closes all connections to the remote port
/// </summary>
/// <param name="port"></param>
public static void CloseRemotePort(int port)
{
MIB_TCPROW[] rows = getTcpTable();
for (int i = 0; i < rows.Length; i++)
{
if (port == ntohs(rows[i].dwRemotePort))
{
rows[i].dwState = (int)State.Delete_TCB;
IntPtr ptr = GetPtrToNewObject(rows[i]);
int ret = SetTcpEntry(ptr);
}
}
}
/// <summary>
/// Closes all connections to the local port
/// </summary>
/// <param name="port"></param>
public static void CloseLocalPort(int port)
{
MIB_TCPROW[] rows = getTcpTable();
for (int i = 0; i < rows.Length; i++)
{
if (port == ntohs(rows[i].dwLocalPort))
{
rows[i].dwState = (int)State.Delete_TCB;
IntPtr ptr = GetPtrToNewObject(rows[i]);
int ret = SetTcpEntry(ptr);
}
}
}
/// <summary>
/// Close a connection by returning the connectionstring
/// </summary>
/// <param name="connectionstring"></param>
public static void CloseConnection(string connectionstring)
{
try
{
//Split the string to its subparts
string[] parts = connectionstring.Split('-');
if (parts.Length != 4) throw new Exception("Invalid connectionstring - use the one provided by Connections.");
string[] loc = parts[0].Split(':');
string[] rem = parts[1].Split(':');
string[] locaddr = loc[0].Split('.');
string[] remaddr = rem[0].Split('.');
//Fill structure with data
MIB_TCPROW row = new MIB_TCPROW();
row.dwState = 12;
byte[] bLocAddr = new byte[] { byte.Parse(locaddr[0]), byte.Parse(locaddr[1]), byte.Parse(locaddr[2]), byte.Parse(locaddr[3]) };
byte[] bRemAddr = new byte[] { byte.Parse(remaddr[0]), byte.Parse(remaddr[1]), byte.Parse(remaddr[2]), byte.Parse(remaddr[3]) };
row.dwLocalAddr = BitConverter.ToInt32(bLocAddr, 0);
row.dwRemoteAddr = BitConverter.ToInt32(bRemAddr, 0);
row.dwLocalPort = htons(int.Parse(loc[1]));
row.dwRemotePort = htons(int.Parse(rem[1]));
//Make copy of the structure into memory and use the pointer to call SetTcpEntry
IntPtr ptr = GetPtrToNewObject(row);
int ret = SetTcpEntry(ptr);
if (ret == -1) throw new Exception("Unsuccessful");
if (ret == 65) throw new Exception("User has no sufficient privilege to execute this API successfully");
if (ret == 87) throw new Exception("Specified port is not in state to be closed down");
if (ret != 0) throw new Exception("Unknown error (" + ret + ")");
}
catch (Exception ex)
{
throw new Exception("CloseConnection failed (" + connectionstring + ")! [" + ex.GetType().ToString() + "," + ex.Message + "]");
}
}
/// <summary>
/// Gets all connections
/// </summary>
/// <returns></returns>
public static string[] Connections()
{
return Connections(State.All);
}
/// <summary>
/// Gets a connection list of connections with a defined state
/// </summary>
/// <param name="state"></param>
/// <returns></returns>
public static string[] Connections(State state)
{
MIB_TCPROW[] rows = getTcpTable();
ArrayList arr = new ArrayList();
foreach (MIB_TCPROW row in rows)
{
if (state == State.All || state == (State)row.dwState)
{
string localaddress = IPIntToString(row.dwLocalAddr) + ":" + ntohs(row.dwLocalPort);
string remoteaddress = IPIntToString(row.dwRemoteAddr) + ":" + ntohs(row.dwRemotePort);
arr.Add(localaddress + "-" + remoteaddress + "-" + ((State)row.dwState).ToString() + "-" + row.dwState);
}
}
return (string[])arr.ToArray(typeof(System.String));
}
//The function that fills the MIB_TCPROW array with connectioninfos
private static MIB_TCPROW[] getTcpTable()
{
IntPtr buffer = IntPtr.Zero; bool allocated = false;
try
{
int iBytes = 0;
GetTcpTable(IntPtr.Zero, ref iBytes, false); //Getting size of return data
buffer = Marshal.AllocCoTaskMem(iBytes); //allocating the datasize
allocated = true;
GetTcpTable(buffer, ref iBytes, false); //Run it again to fill the memory with the data
int structCount = Marshal.ReadInt32(buffer); // Get the number of structures
IntPtr buffSubPointer = buffer; //Making a pointer that will point into the buffer
buffSubPointer = (IntPtr)((int)buffer + 4); //Move to the first data (ignoring dwNumEntries from the original MIB_TCPTABLE struct)
MIB_TCPROW[] tcpRows = new MIB_TCPROW[structCount]; //Declaring the array
//Get the struct size
MIB_TCPROW tmp = new MIB_TCPROW();
int sizeOfTCPROW = Marshal.SizeOf(tmp);
//Fill the array 1 by 1
for (int i = 0; i < structCount; i++)
{
tcpRows[i] = (MIB_TCPROW)Marshal.PtrToStructure(buffSubPointer, typeof(MIB_TCPROW)); //copy struct data
buffSubPointer = (IntPtr)((int)buffSubPointer + sizeOfTCPROW); //move to next structdata
}
return tcpRows;
}
catch (Exception ex)
{
throw new Exception("getTcpTable failed! [" + ex.GetType().ToString() + "," + ex.Message + "]");
}
finally
{
if (allocated) Marshal.FreeCoTaskMem(buffer); //Free the allocated memory
}
}
private static IntPtr GetPtrToNewObject(object obj)
{
IntPtr ptr = Marshal.AllocCoTaskMem(Marshal.SizeOf(obj));
Marshal.StructureToPtr(obj, ptr, false);
return ptr;
}
//Convert an IP string to the INT value
private static int IPStringToInt(string IP)
{
if (IP.IndexOf(".") < 0) throw new Exception("Invalid IP address");
string[] addr = IP.Split('.');
if (addr.Length != 4) throw new Exception("Invalid IP address");
byte[] bytes = new byte[] { byte.Parse(addr[0]), byte.Parse(addr[1]), byte.Parse(addr[2]), byte.Parse(addr[3]) };
return BitConverter.ToInt32(bytes, 0);
}
//Convert an IP integer to IP string
private static string IPIntToString(int IP)
{
byte[] addr = System.BitConverter.GetBytes(IP);
return addr[0] + "." + addr[1] + "." + addr[2] + "." + addr[3];
}
}
}
Very good question and very good answer! And is it possible to get it as EXe of file? Thank you.
Hallo everybody! Tsachi I as well as you interested in this question. On the search of answer spent three days. Decision for Windows here: _ttp://spamcleaner.net/en/misc/wkillcx.html Decision for Linux here: _ttp://spamcleaner.net/en/misc/killcx.html
I am happy! I searched and found! Success!