summaryrefslogtreecommitdiffstats
path: root/avahi-sharp/AddressResolver.cs
blob: c11e97d751f23be7c6630158a78b7ea979267502 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
/***
  This file is part of avahi.

  avahi is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as
  published by the Free Software Foundation; either version 2.1 of the
  License, or (at your option) any later version.

  avahi is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with avahi; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

using System;
using System.Collections;
using System.Net;
using System.Runtime.InteropServices;
using Mono.Unix;

namespace Avahi
{

    internal delegate void AddressResolverCallback (IntPtr resolver, int iface, Protocol proto,
                                                    ResolverEvent revent, IntPtr address,
                                                    IntPtr hostname, LookupResultFlags flags, IntPtr userdata);

    public delegate void HostAddressHandler (object o, HostAddressArgs args);

    public class HostAddressArgs : EventArgs
    {
        private string host;
        private IPAddress address;

        public string Host
        {
            get { return host; }
        }

        public IPAddress Address
        {
            get { return address; }
        }

        public HostAddressArgs (string host, IPAddress address)
        {
            this.host = host;
            this.address = address;
        }
    }

    public class AddressResolver : ResolverBase, IDisposable
    {
        private IntPtr handle;
        private Client client;
        private int iface;
        private Protocol proto;
        private IPAddress address;
        private LookupFlags flags;
        private AddressResolverCallback cb;

        private IPAddress currentAddress;
        private string currentHost;

        private ArrayList foundListeners = new ArrayList ();
        private ArrayList timeoutListeners = new ArrayList ();

        [DllImport ("avahi-client")]
        private static extern IntPtr avahi_address_resolver_new (IntPtr client, int iface, Protocol proto,
                                                                 IntPtr address, LookupFlags flags,
                                                                 AddressResolverCallback cb,
                                                                 IntPtr userdata);

        [DllImport ("avahi-client")]
        private static extern void avahi_address_resolver_free (IntPtr handle);

        public event HostAddressHandler Found
        {
            add {
                foundListeners.Add (value);
                Start ();
            }
            remove {
                foundListeners.Remove (value);
                Stop (false);
            }
        }

        public event EventHandler Timeout
        {
            add {
                timeoutListeners.Add (value);
                Start ();
            }
            remove {
                timeoutListeners.Remove (value);
                Stop (false);
            }
        }

        public IPAddress Address
        {
            get { return currentAddress; }
        }

        public string HostName
        {
            get { return currentHost; }
        }

        public AddressResolver (Client client, IPAddress address) : this (client, -1, Protocol.Unspecified,
                                                                          address, LookupFlags.None)
        {
        }

        public AddressResolver (Client client, int iface, Protocol proto, IPAddress address, LookupFlags flags)
        {
            this.client = client;
            this.iface = iface;
            this.proto = proto;
            this.address = address;
            this.flags = flags;
            cb = OnAddressResolverCallback;
        }

        ~AddressResolver ()
        {
            Dispose ();
        }

        public void Dispose ()
        {
            Stop (true);
        }

        private void Start ()
        {
            if (client.Handle == IntPtr.Zero || handle != IntPtr.Zero ||
                (foundListeners.Count == 0 && timeoutListeners.Count == 0))
                return;

            IntPtr addrPtr = Utility.AddressToPtr (address);

            lock (client) {
                handle = avahi_address_resolver_new (client.Handle, iface, proto, addrPtr, flags,
                                                     cb, IntPtr.Zero);

                if (handle == IntPtr.Zero)
                    client.ThrowError ();
            }

            Utility.Free (addrPtr);
        }

        private void Stop (bool force)
        {
            if (client.Handle != IntPtr.Zero && handle != IntPtr.Zero &&
                (force || (foundListeners.Count == 0 && timeoutListeners.Count == 0))) {

                lock (client) {
                    avahi_address_resolver_free (handle);
                    handle = IntPtr.Zero;
                }
            }
        }

        private void OnAddressResolverCallback (IntPtr resolver, int iface, Protocol proto,
                                                ResolverEvent revent, IntPtr address,
                                                IntPtr hostname, LookupResultFlags flags, IntPtr userdata)
        {
            switch (revent) {
            case ResolverEvent.Found:
                currentAddress = Utility.PtrToAddress (address);
                currentHost = Utility.PtrToString (hostname);

                foreach (HostAddressHandler handler in foundListeners)
                    handler (this, new HostAddressArgs (currentHost, currentAddress));
                break;
            case ResolverEvent.Failure:
                EmitFailure (client.LastError);
                break;
            }
        }
    }
}