RBXLegacy-src/Open.NAT/Open.Nat/Discovery/Searcher.cs

115 lines
4.0 KiB
C#

//
// Authors:
// Ben Motmans <ben.motmans@gmail.com>
// Lucas Ontivero lucasontivero@gmail.com
//
// Copyright (C) 2007 Ben Motmans
// Copyright (C) 2014 Lucas Ontivero
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Threading.Tasks;
namespace Open.Nat
{
internal abstract class Searcher
{
private readonly List<NatDevice> _devices = new List<NatDevice>();
protected List<UdpClient> Sockets;
public EventHandler<DeviceEventArgs> DeviceFound;
internal DateTime NextSearch = DateTime.UtcNow;
public async Task<IEnumerable<NatDevice>> Search(CancellationToken cancelationToken)
{
await Task.Factory.StartNew(async _ =>
{
NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
while (!cancelationToken.IsCancellationRequested)
{
Discover(cancelationToken);
Receive(cancelationToken);
}
CloseSockets();
}, cancelationToken);
return _devices;
}
private void Discover(CancellationToken cancelationToken)
{
if(DateTime.UtcNow < NextSearch) return;
foreach (var socket in Sockets)
{
try
{
Discover(socket, cancelationToken);
}
catch (Exception e)
{
NatDiscoverer.TraceSource.LogError("Error searching {0} - Details:", GetType().Name);
NatDiscoverer.TraceSource.LogError(e.ToString());
}
}
}
private void Receive(CancellationToken cancelationToken)
{
foreach (var client in Sockets.Where(x=>x.Available>0))
{
if(cancelationToken.IsCancellationRequested) return;
var localHost = ((IPEndPoint)client.Client.LocalEndPoint).Address;
var receivedFrom = new IPEndPoint(IPAddress.None, 0);
var buffer = client.Receive(ref receivedFrom);
var device = AnalyseReceivedResponse(localHost, buffer, receivedFrom);
if (device != null) RaiseDeviceFound(device);
}
}
protected abstract void Discover(UdpClient client, CancellationToken cancelationToken);
public abstract NatDevice AnalyseReceivedResponse(IPAddress localAddress, byte[] response, IPEndPoint endpoint);
public void CloseSockets()
{
foreach (var udpClient in Sockets)
{
udpClient.Close();
}
}
private void RaiseDeviceFound(NatDevice device)
{
_devices.Add(device);
var handler = DeviceFound;
if(handler!=null)
handler(this, new DeviceEventArgs(device));
}
}
}