public void getRoutingTable()
{
_routeEntry.Clear();
IPHlpAPI32Wrapper.MIB_IPFORWARDTABLE fTable = new IPHlpAPI32Wrapper.MIB_IPFORWARDTABLE();
fTable.table = new IPHlpAPI32Wrapper.MIB_IPFORWARDROW[1];
int MIB_SIZE = Marshal.SizeOf(new IPHlpAPI32Wrapper.MIB_IPFORWARDROW()) + Marshal.SizeOf(new UInt32());
// Initialize unmanged memory to hold one struct entry.
IntPtr pTable = Marshal.AllocHGlobal(MIB_SIZE);
try
{
// Copy the struct to unmanaged memory.
// Marshal.StructureToPtr(fTable, pTable, false); //StructureToPtr does not like array inside struct
byte[] buffer = new byte[MIB_SIZE];
int dwSize = MIB_SIZE;
int iRes = IPHlpAPI32Wrapper.GetIpForwardTable(buffer, ref dwSize, true);
if (iRes == ERROR_INSUFFICIENT_BUFFER)
{
//need to get dwSize memory allocated
buffer = new byte[dwSize];
iRes = IPHlpAPI32Wrapper.GetIpForwardTable(buffer, ref dwSize, true);
//now we have a list of structs
//see also http://www.pcreview.co.uk/forums/changing-route-table-iphlpapi-dll-and-p-invoke-t2891061.html
//now we have the buffer filled, create an empty entry
IPHlpAPI32Wrapper.MIB_IPFORWARDTABLE ipForwardTable = new IPHlpAPI32Wrapper.MIB_IPFORWARDTABLE();
// ...and fill the MIB_IPFORWARDTABLE with the bytes from the buffer
int nOffset = 0;
// number of rows in the table
ipForwardTable.dwNumEntries = Convert.ToUInt32(buffer[nOffset]);
nOffset += 4;
ipForwardTable.table = new IPHlpAPI32Wrapper.MIB_IPFORWARDROW[ipForwardTable.dwNumEntries];
for (int i = 0; i < ipForwardTable.dwNumEntries; i++)
{
//dwForwardDest
//((MIB_IPFORWARDROW)(ipForwardTable.table[i])).dwForwardDest = Convert.ToUInt32(buffer[nOffset]);
((ipForwardTable.table[i])).dwForwardDest = toIPInt(buffer, nOffset);
nOffset += 4;
//dwForwardMask
((ipForwardTable.table[i])).dwForwardMask = toIPInt(buffer, nOffset);
nOffset += 4;
//dwForwardPolicy
((ipForwardTable.table[i])).dwForwardPolicy = Convert.ToUInt32(buffer[nOffset]);
nOffset += 4;
//dwForwardNextHop
((ipForwardTable.table[i])).dwForwardNextHop = toIPInt(buffer, nOffset);
nOffset += 4;
//dwForwardIfIndex
((ipForwardTable.table[i])).dwForwardIfIndex = Convert.ToUInt32(buffer[nOffset]);
nOffset += 8; //8 since we're skipping the next item (dwForwardType)
//dwForwardProto
((ipForwardTable.table[i])).dwForwardProto = Convert.ToUInt32(buffer[nOffset]);
nOffset += 4;
_routeEntry.Add(ipForwardTable.table[i]);
}
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("Exception: " + ex.Message);
}
finally
{
Marshal.FreeHGlobal(pTable);
}
}
