git.meshlink.io Git - catta/blob - avahi-sharp/AddressResolver.cs

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of avahi.
   5
   6   avahi is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   avahi is distributed in the hope that it will be useful, but WITHOUT
  12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  14   Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with avahi; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 using System;
  23 using System.Collections;
  24 using System.Net;
  25 using System.Runtime.InteropServices;
  26 using Mono.Unix;
  27
  28 namespace Avahi
  29 {
  30
  31     internal delegate void AddressResolverCallback (IntPtr resolver, int iface, Protocol proto,
  32                                                     ResolverEvent revent, Protocol aproto, IntPtr address,
  33                                                     IntPtr hostname, IntPtr userdata);
  34
  35     public delegate void HostAddressHandler (object o, string host, IPAddress address);
  36
  37     public class AddressResolver : IDisposable
  38     {
  39         private IntPtr handle;
  40         private Client client;
  41         private int iface;
  42         private Protocol proto;
  43         private IPAddress address;
  44
  45         private IPAddress currentAddress;
  46         private string currentHost;
  47
  48         private ArrayList foundListeners = new ArrayList ();
  49         private ArrayList timeoutListeners = new ArrayList ();
  50
  51         [DllImport ("avahi-client")]
  52         private static extern IntPtr avahi_address_resolver_new (IntPtr client, int iface, Protocol proto,
  53                                                                  IntPtr address, AddressResolverCallback cb,
  54                                                                  IntPtr userdata);
  55
  56         [DllImport ("avahi-client")]
  57         private static extern void avahi_address_resolver_free (IntPtr handle);
  58
  59         public event HostAddressHandler Found
  60         {
  61             add {
  62                 foundListeners.Add (value);
  63                 Start ();
  64             }
  65             remove {
  66                 foundListeners.Remove (value);
  67                 Stop (false);
  68             }
  69         }
  70
  71         public event EventHandler Timeout
  72         {
  73             add {
  74                 timeoutListeners.Add (value);
  75                 Start ();
  76             }
  77             remove {
  78                 timeoutListeners.Remove (value);
  79                 Stop (false);
  80             }
  81         }
  82
  83         public IPAddress Address
  84         {
  85             get { return currentAddress; }
  86         }
  87
  88         public string HostName
  89         {
  90             get { return currentHost; }
  91         }
  92
  93         public AddressResolver (Client client, IPAddress address) : this (client, -1, Protocol.Unspecified, address)
  94         {
  95         }
  96
  97         public AddressResolver (Client client, int iface, Protocol proto, IPAddress address)
  98         {
  99             this.client = client;
 100             this.iface = iface;
 101             this.proto = proto;
 102             this.address = address;
 103         }
 104
 105         ~AddressResolver ()
 106         {
 107             Dispose ();
 108         }
 109
 110         public void Dispose ()
 111         {
 112             Stop (true);
 113         }
 114
 115         private void Start ()
 116         {
 117             if (handle != IntPtr.Zero || (foundListeners.Count == 0 && timeoutListeners.Count == 0))
 118                 return;
 119
 120             IntPtr addrPtr = Utility.StringToPtr (address.ToString ());
 121             handle = avahi_address_resolver_new (client.Handle, iface, proto, addrPtr,
 122                                                  OnAddressResolverCallback, IntPtr.Zero);
 123             Utility.Free (addrPtr);
 124         }
 125
 126         private void Stop (bool force)
 127         {
 128             if (handle != IntPtr.Zero && (force || (foundListeners.Count == 0 && timeoutListeners.Count == 0))) {
 129                 avahi_address_resolver_free (handle);
 130                 handle = IntPtr.Zero;
 131             }
 132         }
 133
 134         private void OnAddressResolverCallback (IntPtr resolver, int iface, Protocol proto,
 135                                                 ResolverEvent revent, Protocol aproto, IntPtr address,
 136                                                 IntPtr hostname, IntPtr userdata)
 137         {
 138             if (revent == ResolverEvent.Found) {
 139                 currentAddress = Utility.PtrToAddress (address);
 140                 currentHost = Utility.PtrToString (hostname);
 141
 142                 foreach (HostAddressHandler handler in foundListeners)
 143                     handler (this, currentHost, currentAddress);
 144             } else {
 145                 currentAddress = null;
 146                 currentHost = null;
 147
 148                 foreach (EventHandler handler in timeoutListeners)
 149                     handler (this, new EventArgs ());
 150             }
 151         }
 152     }
 153 }