public static bool RouteExists(string destinationIP)
{
List <Ip4RouteEntry> routeTable = Ip4RouteTable.GetRouteTable();
Ip4RouteEntry routeEntry = routeTable.Find(i => i.DestinationIP.ToString().Equals(destinationIP));
return(routeEntry != null);
}
public static List <Ip4RouteEntry> GetRouteTable()
{
var fwdTable = IntPtr.Zero;
int size = 0;
var result = NativeMethods.GetIpForwardTable(fwdTable, ref size, true);
fwdTable = Marshal.AllocHGlobal(size);
result = NativeMethods.GetIpForwardTable(fwdTable, ref size, true);
var forwardTable = NativeMethods.ReadIPForwardTable(fwdTable);
Marshal.FreeHGlobal(fwdTable);
List <Ip4RouteEntry> routeTable = new List <Ip4RouteEntry>();
for (int i = 0; i < forwardTable.Table.Length; ++i)
{
Ip4RouteEntry entry = new Ip4RouteEntry();
entry.DestinationIP = new IPAddress((long)forwardTable.Table[i].dwForwardDest);
entry.SubnetMask = new IPAddress((long)forwardTable.Table[i].dwForwardMask);
entry.GatewayIP = new IPAddress((long)forwardTable.Table[i].dwForwardNextHop);
entry.InterfaceIndex = Convert.ToInt32(forwardTable.Table[i].dwForwardIfIndex);
entry.ForwardType = Convert.ToInt32(forwardTable.Table[i].dwForwardType);
entry.ForwardProtocol = Convert.ToInt32(forwardTable.Table[i].dwForwardProto);
entry.ForwardAge = Convert.ToInt32(forwardTable.Table[i].dwForwardAge);
entry.Metric = Convert.ToInt32(forwardTable.Table[i].dwForwardMetric1);
routeTable.Add(entry);
}
return(routeTable);
}
public static bool InterfaceIndexExists(int interfaceIndex)
{
List <Ip4RouteEntry> routeTable = Ip4RouteTable.GetRouteTable();
Ip4RouteEntry routeEntry = routeTable.Find(i => i.InterfaceIndex.Equals(interfaceIndex));
return(routeEntry != null);
}
public static void DeleteRoute(Ip4RouteEntry routeEntry)
{
var route = new NativeMethods.MIB_IPFORWARDROW
{
dwForwardDest = BitConverter.ToUInt32(IPAddress.Parse(routeEntry.DestinationIP.ToString()).GetAddressBytes(), 0),
dwForwardMask = BitConverter.ToUInt32(IPAddress.Parse(routeEntry.SubnetMask.ToString()).GetAddressBytes(), 0),
dwForwardNextHop = BitConverter.ToUInt32(IPAddress.Parse(routeEntry.GatewayIP.ToString()).GetAddressBytes(), 0),
dwForwardMetric1 = 99,
dwForwardType = Convert.ToUInt32(3), //Default to 3
dwForwardProto = Convert.ToUInt32(3), //Default to 3
dwForwardAge = 0,
dwForwardIfIndex = Convert.ToUInt32(routeEntry.InterfaceIndex)
};
IntPtr ptr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(NativeMethods.MIB_IPFORWARDROW)));
try
{
Marshal.StructureToPtr(route, ptr, false);
var status = NativeMethods.DeleteIpForwardEntry(ptr);
}
finally
{
Marshal.FreeHGlobal(ptr);
}
}