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

   1 using System;
   2 using System.Collections;
   3 using System.Net;
   4 using System.Runtime.InteropServices;
   5 using Mono.Unix;
   6
   7 namespace Avahi
   8 {
   9
  10     internal delegate void AddressResolverCallback (IntPtr resolver, int iface, Protocol proto,
  11                                                     ResolverEvent revent, Protocol aproto, IntPtr address,
  12                                                     IntPtr hostname, IntPtr userdata);
  13
  14     public delegate void HostAddressHandler (object o, string host, IPAddress address);
  15
  16     public class AddressResolver : IDisposable
  17     {
  18         private IntPtr handle;
  19         private Client client;
  20         private int iface;
  21         private Protocol proto;
  22         private IPAddress address;
  23
  24         private IPAddress currentAddress;
  25         private string currentHost;
  26
  27         private ArrayList foundListeners = new ArrayList ();
  28         private ArrayList timeoutListeners = new ArrayList ();
  29
  30         [DllImport ("avahi-client")]
  31         private static extern IntPtr avahi_address_resolver_new (IntPtr client, int iface, Protocol proto,
  32                                                                  IntPtr address, AddressResolverCallback cb,
  33                                                                  IntPtr userdata);
  34
  35         [DllImport ("avahi-client")]
  36         private static extern void avahi_address_resolver_free (IntPtr handle);
  37
  38         public event HostAddressHandler Found
  39         {
  40             add {
  41                 foundListeners.Add (value);
  42                 Start ();
  43             }
  44             remove {
  45                 foundListeners.Remove (value);
  46                 Stop (false);
  47             }
  48         }
  49
  50         public event EventHandler Timeout
  51         {
  52             add {
  53                 timeoutListeners.Add (value);
  54                 Start ();
  55             }
  56             remove {
  57                 timeoutListeners.Remove (value);
  58                 Stop (false);
  59             }
  60         }
  61
  62         public IPAddress Address
  63         {
  64             get { return currentAddress; }
  65         }
  66
  67         public string HostName
  68         {
  69             get { return currentHost; }
  70         }
  71
  72         public AddressResolver (Client client, IPAddress address) : this (client, -1, Protocol.Unspecified, address)
  73         {
  74         }
  75
  76         public AddressResolver (Client client, int iface, Protocol proto, IPAddress address)
  77         {
  78             this.client = client;
  79             this.iface = iface;
  80             this.proto = proto;
  81             this.address = address;
  82         }
  83
  84         ~AddressResolver ()
  85         {
  86             Dispose ();
  87         }
  88
  89         public void Dispose ()
  90         {
  91             Stop (true);
  92         }
  93
  94         private void Start ()
  95         {
  96             if (handle != IntPtr.Zero || (foundListeners.Count == 0 && timeoutListeners.Count == 0))
  97                 return;
  98
  99             IntPtr addrPtr = Utility.StringToPtr (address.ToString ());
 100             handle = avahi_address_resolver_new (client.Handle, iface, proto, addrPtr,
 101                                                  OnAddressResolverCallback, IntPtr.Zero);
 102             Utility.Free (addrPtr);
 103         }
 104
 105         private void Stop (bool force)
 106         {
 107             if (handle != IntPtr.Zero && (force || (foundListeners.Count == 0 && timeoutListeners.Count == 0))) {
 108                 avahi_address_resolver_free (handle);
 109                 handle = IntPtr.Zero;
 110             }
 111         }
 112
 113         private void OnAddressResolverCallback (IntPtr resolver, int iface, Protocol proto,
 114                                                 ResolverEvent revent, Protocol aproto, IntPtr address,
 115                                                 IntPtr hostname, IntPtr userdata)
 116         {
 117             if (revent == ResolverEvent.Found) {
 118                 currentAddress = Utility.PtrToAddress (address);
 119                 currentHost = Utility.PtrToString (hostname);
 120
 121                 foreach (HostAddressHandler handler in foundListeners)
 122                     handler (this, currentHost, currentAddress);
 123             } else {
 124                 currentAddress = null;
 125                 currentHost = null;
 126
 127                 foreach (EventHandler handler in timeoutListeners)
 128                     handler (this, new EventArgs ());
 129             }
 130         }
 131     }
 132 }