public void GetExTcpConnections()
{
// the size of the MIB_EXTCPROW struct = 6*DWORD
int rowsize = 24;
int BufferSize = 100000;
// allocate a dumb memory space in order to retrieve nb of connection
IntPtr lpTable = Marshal.AllocHGlobal(BufferSize);
//getting infos
int res = IPHlpAPI32Wrapper.AllocateAndGetTcpExTableFromStack(ref lpTable, true, IPHlpAPI32Wrapper.GetProcessHeap(), 0, 2);
if (res != Utils.NO_ERROR)
{
Debug.WriteLine("Error : " + IPHlpAPI32Wrapper.GetAPIErrorMessageDescription(res) + " " + res);
return; // Error. You should handle it
}
int CurrentIndex = 0;
//get the number of entries in the table
int NumEntries = (int)Marshal.ReadIntPtr(lpTable);
lpTable = IntPtr.Zero;
// free allocated space in memory
Marshal.FreeHGlobal(lpTable);
///////////////////
// calculate the real buffer size nb of entrie * size of the struct for each entrie(24) + the dwNumEntries
BufferSize = (NumEntries * rowsize) + 4;
// make the struct to hold the resullts
TcpExConnections = new IpHlpApidotnet.MIB_EXTCPTABLE();
// Allocate memory
lpTable = Marshal.AllocHGlobal(BufferSize);
res = IPHlpAPI32Wrapper.AllocateAndGetTcpExTableFromStack(ref lpTable, true, IPHlpAPI32Wrapper.GetProcessHeap(), 0, 2);
if (res != Utils.NO_ERROR)
{
Debug.WriteLine("Error : " + IPHlpAPI32Wrapper.GetAPIErrorMessageDescription(res) + " " + res);
return; // Error. You should handle it
}
// New pointer of iterating throught the data
IntPtr current = lpTable;
CurrentIndex = 0;
// get the (again) the number of entries
NumEntries = (int)Marshal.ReadIntPtr(current);
TcpExConnections.dwNumEntries = NumEntries;
// Make the array of entries
TcpExConnections.table = new MIB_EXTCPROW[NumEntries];
// iterate the pointer of 4 (the size of the DWORD dwNumEntries)
CurrentIndex += 4;
current = (IntPtr)((int)current + CurrentIndex);
// for each entries
for (int i = 0; i < NumEntries; i++)
{
// The state of the connection (in string)
TcpExConnections.table[i].StrgState = Utils.StateToStr((int)Marshal.ReadIntPtr(current));
// The state of the connection (in ID)
TcpExConnections.table[i].iState = (int)Marshal.ReadIntPtr(current);
// iterate the pointer of 4
current = (IntPtr)((int)current + 4);
// get the local address of the connection
UInt32 localAddr = (UInt32)Marshal.ReadIntPtr(current);
// iterate the pointer of 4
current = (IntPtr)((int)current + 4);
// get the local port of the connection
UInt32 localPort = (UInt32)Marshal.ReadIntPtr(current);
// iterate the pointer of 4
current = (IntPtr)((int)current + 4);
// Store the local endpoint in the struct and convertthe port in decimal (ie convert_Port())
TcpExConnections.table[i].Local = new IPEndPoint(localAddr, (int)Utils.ConvertPort(localPort));
// get the remote address of the connection
UInt32 RemoteAddr = (UInt32)Marshal.ReadIntPtr(current);
// iterate the pointer of 4
current = (IntPtr)((int)current + 4);
UInt32 RemotePort = 0;
// if the remote address = 0 (0.0.0.0) the remote port is always 0
// else get the remote port
if (RemoteAddr != 0)
{
RemotePort = (UInt32)Marshal.ReadIntPtr(current);
RemotePort = Utils.ConvertPort(RemotePort);
}
current = (IntPtr)((int)current + 4);
// store the remote endpoint in the struct and convertthe port in decimal (ie convert_Port())
TcpExConnections.table[i].Remote = new IPEndPoint(RemoteAddr, (int)RemotePort);
// store the process ID
TcpExConnections.table[i].dwProcessId = (int)Marshal.ReadIntPtr(current);
// Store and get the process name in the struct
TcpExConnections.table[i].ProcessName = Utils.GetProcessNameByPID(TcpExConnections.table[i].dwProcessId);
current = (IntPtr)((int)current + 4);
}
// free the buffer
Marshal.FreeHGlobal(lpTable);
// re init the pointer
current = IntPtr.Zero;
}
