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         private AddressResolverCallback cb;
  45
  46         private IPAddress currentAddress;
  47         private string currentHost;
  48
  49         private ArrayList foundListeners = new ArrayList ();
  50         private ArrayList timeoutListeners = new ArrayList ();
  51
  52         [DllImport ("avahi-client")]
  53         private static extern IntPtr avahi_address_resolver_new (IntPtr client, int iface, Protocol proto,
  54                                                                  IntPtr address, AddressResolverCallback cb,
  55                                                                  IntPtr userdata);
  56
  57         [DllImport ("avahi-client")]
  58         private static extern void avahi_address_resolver_free (IntPtr handle);
  59
  60         public event HostAddressHandler Found
  61         {
  62             add {
  63                 foundListeners.Add (value);
  64                 Start ();
  65             }
  66             remove {
  67                 foundListeners.Remove (value);
  68                 Stop (false);
  69             }
  70         }
  71
  72         public event EventHandler Timeout
  73         {
  74             add {
  75                 timeoutListeners.Add (value);
  76                 Start ();
  77             }
  78             remove {
  79                 timeoutListeners.Remove (value);
  80                 Stop (false);
  81             }
  82         }
  83
  84         public IPAddress Address
  85         {
  86             get { return currentAddress; }
  87         }
  88
  89         public string HostName
  90         {
  91             get { return currentHost; }
  92         }
  93
  94         public AddressResolver (Client client, IPAddress address) : this (client, -1, Protocol.Unspecified, address)
  95         {
  96         }
  97
  98         public AddressResolver (Client client, int iface, Protocol proto, IPAddress address)
  99         {
 100             this.client = client;
 101             this.iface = iface;
 102             this.proto = proto;
 103             this.address = address;
 104             cb = OnAddressResolverCallback;
 105         }
 106
 107         ~AddressResolver ()
 108         {
 109             Dispose ();
 110         }
 111
 112         public void Dispose ()
 113         {
 114             Stop (true);
 115         }
 116
 117         private void Start ()
 118         {
 119             if (client.Handle == IntPtr.Zero || handle != IntPtr.Zero ||
 120                 (foundListeners.Count == 0 && timeoutListeners.Count == 0))
 121                 return;
 122
 123             IntPtr addrPtr = Utility.StringToPtr (address.ToString ());
 124
 125             lock (client) {
 126                 handle = avahi_address_resolver_new (client.Handle, iface, proto, addrPtr,
 127                                                      cb, IntPtr.Zero);
 128             }
 129
 130             Utility.Free (addrPtr);
 131         }
 132
 133         private void Stop (bool force)
 134         {
 135             if (client.Handle != IntPtr.Zero && handle != IntPtr.Zero &&
 136                 (force || (foundListeners.Count == 0 && timeoutListeners.Count == 0))) {
 137
 138                 lock (client) {
 139                     avahi_address_resolver_free (handle);
 140                     handle = IntPtr.Zero;
 141                 }
 142             }
 143         }
 144
 145         private void OnAddressResolverCallback (IntPtr resolver, int iface, Protocol proto,
 146                                                 ResolverEvent revent, Protocol aproto, IntPtr address,
 147                                                 IntPtr hostname, IntPtr userdata)
 148         {
 149             if (revent == ResolverEvent.Found) {
 150                 currentAddress = Utility.PtrToAddress (address);
 151                 currentHost = Utility.PtrToString (hostname);
 152
 153                 foreach (HostAddressHandler handler in foundListeners)
 154                     handler (this, currentHost, currentAddress);
 155             } else {
 156                 currentAddress = null;
 157                 currentHost = null;
 158
 159                 foreach (EventHandler handler in timeoutListeners)
 160                     handler (this, new EventArgs ());
 161             }
 162         }
 163     }
 164 }