public void Scan(ICollection <IpV4Address> addresses)
{
if (IsScanning)
{
return;
}
IsScanning = true;
_totalScans = addresses.Count;
_finishedScans = 0;
var sourceAddress = ((IpV4SocketAddress)_networkInfo.InterfaceAddress.Address).Address;
var sourcePhysicalAddress = _networkInfo.Interface.GetNetworkInterface().GetPhysicalAddress();
_tokenSource = new CancellationTokenSource();
var cancellationToken = _tokenSource.Token;
var discoveredHosts = new List <Host>();
Task.Run(() =>
{
while (true)
{
if (cancellationToken.IsCancellationRequested)
{
break;
}
_networkInfo.Communicator.ReceivePacket(out Packet p);
if (!cancellationToken.IsCancellationRequested &&
p != null &&
p.IsValid &&
p.Ethernet.IsValid &&
p.Ethernet.EtherType == EthernetType.Arp &&
p.Ethernet.Arp.IsValid &&
p.Ethernet.Arp.Operation == ArpOperation.Reply &&
addresses.Contains(p.Ethernet.Arp.SenderProtocolIpV4Address) &&
p.Ethernet.Arp.TargetProtocolIpV4Address == sourceAddress)
{
var host = new Host(
p.Ethernet.Arp.SenderProtocolIpV4Address,
new MacAddress(BitConverter.ToString(p.Ethernet.Arp.SenderHardwareAddress.ToArray()).Replace('-', ':'))
);
if (!discoveredHosts.Contains(host))
{
discoveredHosts.Add(host);
}
}
}
}, cancellationToken);
Task.Run(() =>
{
foreach (var addr in addresses)
{
var packet = PacketBuilder.Build(
DateTime.Now,
new EthernetLayer()
{
EtherType = EthernetType.None,
Source = NetworkUtilities.PhysicalAddressToMacAddress(sourcePhysicalAddress),
Destination = NetworkUtilities.BroadcastMac,
},
new ArpLayer()
{
ProtocolType = EthernetType.IpV4,
Operation = ArpOperation.Request,
SenderProtocolAddress = sourceAddress.ToBytes(),
SenderHardwareAddress = sourcePhysicalAddress.GetAddressBytes().AsReadOnly(),
TargetProtocolAddress = addr.ToBytes(),
TargetHardwareAddress = MacAddress.Zero.ToBytes(),
}
);
_networkInfo.Communicator.SendPacket(packet);
if (cancellationToken.IsCancellationRequested)
{
break;
}
Interlocked.Increment(ref _finishedScans);
OnHostScanned(new HostScannedEventArgs(_totalScans, _finishedScans));
Thread.Sleep(Config.ScanSendInterval);
}
if (!cancellationToken.IsCancellationRequested)
{
Thread.Sleep(Config.ScanReplyTimeout);
_tokenSource.Cancel();
foreach (var host in discoveredHosts)
{
host.HostName = NetworkUtilities.GetHostNameByIp(host.IpAddress);
}
OnScanFinished(new ScanFinishedEventArgs(discoveredHosts));
}
IsScanning = false;
}, cancellationToken);
}