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using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
namespace Hazel.Udp
{
public class BroadcastPacket
{
public string Data;
public DateTime ReceiveTime;
public IPEndPoint Sender;
public BroadcastPacket(string data, IPEndPoint sender)
{
this.Data = data;
this.Sender = sender;
this.ReceiveTime = DateTime.Now;
}
public string GetAddress()
{
return this.Sender.Address.ToString();
}
}
public class UdpBroadcastListener : IDisposable
{
private Socket socket;
private EndPoint endpoint;
private Action<string> logger;
private byte[] buffer = new byte[1024];
private List<BroadcastPacket> packets = new List<BroadcastPacket>();
public bool Running { get; private set; }
///
public UdpBroadcastListener(int port, Action<string> logger = null)
{
this.logger = logger;
this.socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
this.socket.EnableBroadcast = true;
this.socket.MulticastLoopback = false;
this.endpoint = new IPEndPoint(IPAddress.Any, port);
this.socket.Bind(this.endpoint);
}
///
public void StartListen()
{
if (this.Running) return;
this.Running = true;
try
{
EndPoint endpt = new IPEndPoint(IPAddress.Any, 0);
this.socket.BeginReceiveFrom(buffer, 0, buffer.Length, SocketFlags.None, ref endpt, this.HandleData, null);
}
catch (NullReferenceException) { }
catch (Exception e)
{
this.logger?.Invoke("BroadcastListener: " + e);
this.Dispose();
}
}
private void HandleData(IAsyncResult result)
{
this.Running = false;
int numBytes;
EndPoint endpt = new IPEndPoint(IPAddress.Any, 0);
try
{
numBytes = this.socket.EndReceiveFrom(result, ref endpt);
}
catch (NullReferenceException)
{
// Already disposed
return;
}
catch (Exception e)
{
this.logger?.Invoke("BroadcastListener: " + e);
this.Dispose();
return;
}
if (numBytes < 3
|| buffer[0] != 4 || buffer[1] != 2)
{
this.StartListen();
return;
}
IPEndPoint ipEnd = (IPEndPoint)endpt;
string data = UTF8Encoding.UTF8.GetString(buffer, 2, numBytes - 2);
int dataHash = data.GetHashCode();
lock (packets)
{
bool found = false;
for (int i = 0; i < this.packets.Count; ++i)
{
var pkt = this.packets[i];
if (pkt == null || pkt.Data == null)
{
this.packets.RemoveAt(i);
i--;
continue;
}
if (pkt.Data.GetHashCode() == dataHash
&& pkt.Sender.Equals(ipEnd))
{
this.packets[i].ReceiveTime = DateTime.Now;
break;
}
}
if (!found)
{
this.packets.Add(new BroadcastPacket(data, ipEnd));
}
}
this.StartListen();
}
///
public BroadcastPacket[] GetPackets()
{
lock (this.packets)
{
var output = this.packets.ToArray();
this.packets.Clear();
return output;
}
}
///
public void Dispose()
{
if (this.socket != null)
{
try { this.socket.Shutdown(SocketShutdown.Both); } catch { }
try { this.socket.Close(); } catch { }
try { this.socket.Dispose(); } catch { }
this.socket = null;
}
}
}
}
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