private static bool PeekARP(System.Net.IPAddress adr)
{
byte[] macAddr = new byte[6];
uint macAddrLen = (uint)macAddr.Length;
int Ret = SendARP((int)adr.Address, 0, macAddr, ref macAddrLen);
System.Diagnostics.Trace.WriteLine(string.Format("Peeking {0} as {1}", adr.ToString(), Ret));
return(Ret == 0);
}
public static PrefixedIPv4Address NextAddress(PrefixedIPv4Address Orig)
{
System.Net.IPAddress adr = null;
System.Diagnostics.Trace.WriteLine("Parsing address" + Orig.Address);
if (!System.Net.IPAddress.TryParse(Orig.Address, out adr))
{
System.Diagnostics.Trace.WriteLine("Failed with parsing");
return(Orig);
}
long from = (adr.Address >> 24) & 0xff;
long i;
/*
* if (!PeekARP(adr))
* { // ARP not available - so just guess
* i = from + 1;
* if (i >= 254) i = 1;
* adr.Address = (adr.Address & 0xffffff) | (i << 24);
* return new PrefixedIPv4Address() { Address = adr.ToString(), PrefixLength = Orig.PrefixLength };
* }*/
// do ARP scanning, after current
for (i = from + 1; i <= 254; i++)
{
adr.Address = (adr.Address & 0xffffff) | (i << 24);
if (!PeekARP(adr))
{
break;
}
}
if (i >= 254)
{
// do ARP scanning, before current
for (i = 1; i < from; i++)
{
adr.Address = (adr.Address & 0xffffff) | (i << 24);
if (!PeekARP(adr))
{
break;
}
}
// nothing found - just guess
if (i >= from)
{
i = from + 1;
if (i >= 254)
{
i = 1;
}
adr.Address = (adr.Address & 0xffffff) | (i << 24);
}
}
return(new PrefixedIPv4Address()
{
Address = adr.ToString(), PrefixLength = Orig.PrefixLength
});
}