/// <summary>
/// This retrieves all current TCPIP connections, filters them based on a process id (specified by either ProcessID or ProcessWindowName parameter),
/// and updates the connections collection.
/// </summary>
/// <param name="connections">List containing prior connections that needs to be maintained</param>
public unsafe void UpdateTCPIPConnections(List <TCPConnection> connections)
{
if (ProcessID > 0)
{
_currentProcessID = ProcessID;
}
else
{
_currentProcessID = GetProcessIDByWindowName(ProcessWindowName);
}
if (_currentProcessID == 0)
{
if (connections.Count > 0)
{
Trace.WriteLine("ProcessTCPInfo: Process has exited, closing all connections.");
connections.Clear();
}
return;
}
IntPtr ptrTCPTable = IntPtr.Zero;
int bufferLength = 0;
int ret = 0;
int tcpTableCount = 0;
IntPtr tmpPtr = IntPtr.Zero;
// attempt to allocate 5 times, in case there are frequent increases in the # of tcp connections
for (int i = 0; i < 5; i++)
{
ret = GetExtendedTcpTable(ptrTCPTable, ref bufferLength, false, AF_INET, TCP_TABLE_CLASS.TCP_TABLE_OWNER_PID_ALL, 0);
if (ret == 0)
{
break;
}
if (ptrTCPTable != IntPtr.Zero)
{
Marshal.FreeHGlobal(ptrTCPTable);
ptrTCPTable = IntPtr.Zero;
}
ptrTCPTable = Marshal.AllocHGlobal(bufferLength);
}
try
{
if (ret == 0)
{
//retrieving numbers of entries
tcpTableCount = *(int *)ptrTCPTable;
tmpPtr = ptrTCPTable + sizeof(Int32);
for (int i = 0; i <= tcpTableCount - 1; i++)
{
MIB_TCPROW_EX entry = *(MIB_TCPROW_EX *)tmpPtr;
// Process if ProcessID matches
if (entry.dwProcessId == _currentProcessID)
{
bool bFound = false;
for (int j = 0; j < connections.Count; j++)
{
if (connections[j].LocalIP == entry.dwLocalAddr &&
connections[j].RemoteIP == entry.dwRemoteAddr &&
connections[j].LocalPort == (ushort)System.Net.IPAddress.NetworkToHostOrder((short)entry.dwLocalPort) &&
connections[j].RemotePort == (ushort)System.Net.IPAddress.NetworkToHostOrder((short)entry.dwRemotePort)
)
{
bFound = true;
break;
}
}
if (!bFound)
{
var connection = new TCPConnection()
{
LocalIP = entry.dwLocalAddr,
RemoteIP = entry.dwRemoteAddr,
LocalPort = (ushort)System.Net.IPAddress.NetworkToHostOrder((short)entry.dwLocalPort),
RemotePort = (ushort)System.Net.IPAddress.NetworkToHostOrder((short)entry.dwRemotePort)
};
connections.Add(connection);
Trace.WriteLine("ProcessTCPInfo: New connection detected for Process [" + _currentProcessID.ToString() + "]: " + connection.ToString());
}
}
// increment pointer
tmpPtr += sizeof(MIB_TCPROW_EX);
}
for (int i = connections.Count - 1; i >= 0; i--)
{
bool bFound = false;
tmpPtr = ptrTCPTable + sizeof(Int32);
for (int j = 0; j <= tcpTableCount - 1; j++)
{
MIB_TCPROW_EX entry = *(MIB_TCPROW_EX *)tmpPtr;
// Process if ProcessID matches
if (entry.dwProcessId == _currentProcessID)
{
if (connections[i].LocalIP == entry.dwLocalAddr &&
connections[i].RemoteIP == entry.dwRemoteAddr &&
connections[i].LocalPort == (ushort)System.Net.IPAddress.NetworkToHostOrder((short)entry.dwLocalPort) &&
connections[i].RemotePort == (ushort)System.Net.IPAddress.NetworkToHostOrder((short)entry.dwRemotePort)
)
{
bFound = true;
break;
}
}
// increment pointer
tmpPtr += sizeof(MIB_TCPROW_EX);
}
if (!bFound)
{
Trace.WriteLine("ProcessTCPInfo: Removed connection " + connections[i].ToString());
connections.RemoveAt(i);
}
}
}
else
{
Trace.WriteLine("ProcessTCPInfo: Unable to retrieve TCP table. Return code: " + ret.ToString());
throw new System.ComponentModel.Win32Exception(ret);
}
}
catch (Exception ex)
{
Trace.WriteLine("ProcessTCPInfo: Exception updating TCP connection list." + ex.ToString());
throw new System.ComponentModel.Win32Exception(ret, ex.Message);
}
finally
{
Marshal.FreeHGlobal(ptrTCPTable);
}
}