jellyfin-server/Mono.Nat/Pmp/Searchers/PmpSearcher.cs
2016-09-11 03:33:53 -04:00

150 lines
4.7 KiB
C#

//
// Authors:
// Alan McGovern alan.mcgovern@gmail.com
// Ben Motmans <ben.motmans@gmail.com>
// Nicholas Terry <nick.i.terry@gmail.com>
//
// Copyright (C) 2006 Alan McGovern
// Copyright (C) 2007 Ben Motmans
// Copyright (C) 2014 Nicholas Terry
//
// 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.Text;
using System.Net;
using Mono.Nat.Pmp;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Linq;
namespace Mono.Nat
{
internal class PmpSearcher : Pmp.Pmp, ISearcher
{
static PmpSearcher instance = new PmpSearcher();
public static PmpSearcher Instance
{
get { return instance; }
}
private int timeout;
private DateTime nextSearch;
public event EventHandler<DeviceEventArgs> DeviceFound;
public event EventHandler<DeviceEventArgs> DeviceLost;
static PmpSearcher()
{
CreateSocketsAndAddGateways();
}
PmpSearcher()
{
timeout = 250;
}
public void Search()
{
foreach (UdpClient s in sockets)
{
try
{
Search(s);
}
catch
{
// Ignore any search errors
}
}
}
void Search (UdpClient client)
{
// Sort out the time for the next search first. The spec says the
// timeout should double after each attempt. Once it reaches 64 seconds
// (and that attempt fails), assume no devices available
nextSearch = DateTime.Now.AddMilliseconds(timeout);
timeout *= 2;
// We've tried 9 times as per spec, try searching again in 5 minutes
if (timeout == 128 * 1000)
{
timeout = 250;
nextSearch = DateTime.Now.AddMinutes(10);
return;
}
// The nat-pmp search message. Must be sent to GatewayIP:53531
byte[] buffer = new byte[] { PmpConstants.Version, PmpConstants.OperationCode };
foreach (IPEndPoint gatewayEndpoint in gatewayLists[client])
client.Send(buffer, buffer.Length, gatewayEndpoint);
}
bool IsSearchAddress(IPAddress address)
{
foreach (List<IPEndPoint> gatewayList in gatewayLists.Values)
foreach (IPEndPoint gatewayEndpoint in gatewayList)
if (gatewayEndpoint.Address.Equals(address))
return true;
return false;
}
public void Handle(IPAddress localAddress, byte[] response, IPEndPoint endpoint)
{
if (!IsSearchAddress(endpoint.Address))
return;
if (response.Length != 12)
return;
if (response[0] != PmpConstants.Version)
return;
if (response[1] != PmpConstants.ServerNoop)
return;
int errorcode = IPAddress.NetworkToHostOrder(BitConverter.ToInt16(response, 2));
if (errorcode != 0)
NatUtility.Log("Non zero error: {0}", errorcode);
IPAddress publicIp = new IPAddress(new byte[] { response[8], response[9], response[10], response[11] });
nextSearch = DateTime.Now.AddMinutes(5);
timeout = 250;
OnDeviceFound(new DeviceEventArgs(new PmpNatDevice(endpoint.Address, publicIp)));
}
public DateTime NextSearch
{
get { return nextSearch; }
}
private void OnDeviceFound(DeviceEventArgs args)
{
if (DeviceFound != null)
DeviceFound(this, args);
}
public NatProtocol Protocol
{
get { return NatProtocol.Pmp; }
}
}
}