mcs/class/System/System.Net.Sockets/TcpListener.cs

   1 // TcpListener.cs
   2 //
   3 // Authors:
   4 //    Phillip Pearson (pp@myelin.co.nz)
   5 //    Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //        Patrik Torstensson
   7 //    Sridhar Kulkarni (sridharkulkarni@gmail.com)
   8 //    Marek Safar (marek.safar@gmail.com)
   9
  10 //
  11 // Copyright (C) 2001, Phillip Pearson http://www.myelin.co.nz
  12 //
  13 // (c) 2003 Ximian, Inc. (http://www.ximian.com)
  14 // (c) 2004-2006 Novell, Inc.
  15 // Copyright 2011 Xamarin Inc.
  16 //
  17
  18 //
  19 // Permission is hereby granted, free of charge, to any person obtaining
  20 // a copy of this software and associated documentation files (the
  21 // "Software"), to deal in the Software without restriction, including
  22 // without limitation the rights to use, copy, modify, merge, publish,
  23 // distribute, sublicense, and/or sell copies of the Software, and to
  24 // permit persons to whom the Software is furnished to do so, subject to
  25 // the following conditions:
  26 //
  27 // The above copyright notice and this permission notice shall be
  28 // included in all copies or substantial portions of the Software.
  29 //
  30 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  31 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  32 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  33 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  34 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  35 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  36 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  37 //
  38
  39 using System;
  40 using System.Net;
  41 #if NET_4_5
  42 using System.Threading.Tasks;
  43 #endif
  44
  45 namespace System.Net.Sockets
  46 {
  47         /// <remarks>
  48         /// A slightly more abstracted way to listen for incoming
  49         /// network connections than a Socket.
  50         /// </remarks>
  51         public class TcpListener
  52         {
  53                 // private data
  54
  55                 bool active;
  56                 Socket server;
  57                 EndPoint savedEP;
  58
  59                 // constructor
  60
  61                 /// <summary>
  62                 /// Some code that is shared between the constructors.
  63                 /// </summary>
  64                 private void Init (AddressFamily family, EndPoint ep)
  65                 {
  66                         active = false;
  67                         server = new Socket(family, SocketType.Stream, ProtocolType.Tcp);
  68                         savedEP = ep;
  69                 }
  70
  71                 /// <summary>
  72                 /// Constructs a new TcpListener to listen on a specified port
  73                 /// </summary>
  74                 /// <param name="port">The port to listen on, e.g. 80 if you
  75                 /// are a web server</param>
  76                 [Obsolete ("Use TcpListener (IPAddress address, int port) instead")]
  77                 public TcpListener (int port)
  78                 {
  79                         if (port < 0 || port > 65535)
  80                                 throw new ArgumentOutOfRangeException ("port");
  81
  82                         Init (AddressFamily.InterNetwork, new IPEndPoint (IPAddress.Any, port));
  83                 }
  84
  85                 /// <summary>
  86                 /// Constructs a new TcpListener with a specified local endpoint
  87                 /// </summary>
  88                 /// <param name="local_end_point">The endpoint</param>
  89                 public TcpListener (IPEndPoint localEP)
  90                 {
  91                         if (localEP == null)
  92                                 throw new ArgumentNullException ("localEP");
  93
  94                         Init (localEP.AddressFamily, localEP);
  95                 }
  96
  97                 /// <summary>
  98                 /// Constructs a new TcpListener, listening on a specified port
  99                 /// and IP (for use on a multi-homed machine)
 100                 /// </summary>
 101                 /// <param name="listen_ip">The IP to listen on</param>
 102                 /// <param name="port">The port to listen on</param>
 103                 public TcpListener (IPAddress localaddr, int port)
 104                 {
 105                         if (localaddr == null)
 106                                 throw new ArgumentNullException ("localaddr");
 107
 108                         if (port < 0 || port > 65535)
 109                                 throw new ArgumentOutOfRangeException ("port");
 110
 111                         Init (localaddr.AddressFamily, new IPEndPoint (localaddr, port));
 112                 }
 113
 114
 115                 // properties
 116
 117                 /// <summary>
 118                 /// A flag that is 'true' if the TcpListener is listening,
 119                 /// or 'false' if it is not listening
 120                 /// </summary>
 121                 protected bool Active
 122                 {
 123                         get { return active; }
 124                 }
 125
 126                 /// <summary>
 127                 /// The local end point
 128                 /// </summary>
 129                 public EndPoint LocalEndpoint
 130                 {
 131                         get {
 132                                 if (active)
 133                                         return server.LocalEndPoint;
 134
 135                                 return savedEP;
 136                         }
 137                 }
 138
 139                 /// <summary>
 140                 /// The listening socket
 141                 /// </summary>
 142                 public Socket Server
 143                 {
 144                         get { return server; }
 145                 }
 146
 147                 /// <summary>
 148                 /// Specifies whether the TcpListener allows only one
 149                 /// underlying socket to listen to a specific port
 150                 /// </summary>
 151 #if TARGET_JVM
 152                 [MonoNotSupported ("Not supported as Socket.ExclusiveAddressUse is not supported")]
 153 #endif
 154                 public bool ExclusiveAddressUse
 155                 {
 156                         get {
 157                                 if (server == null) {
 158                                         throw new ObjectDisposedException (GetType ().ToString ());
 159                                 }
 160                                 if (active) {
 161                                         throw new InvalidOperationException ("The TcpListener has been started");
 162                                 }
 163
 164                                 return(server.ExclusiveAddressUse);
 165                         }
 166                         set {
 167                                 if (server == null) {
 168                                         throw new ObjectDisposedException (GetType ().ToString ());
 169                                 }
 170                                 if (active) {
 171                                         throw new InvalidOperationException ("The TcpListener has been started");
 172                                 }
 173
 174                                 server.ExclusiveAddressUse = value;
 175                         }
 176                 }
 177
 178                 // methods
 179
 180                 /// <summary>
 181                 /// Accepts a pending connection
 182                 /// </summary>
 183                 /// <returns>A Socket object for the new connection</returns>
 184                 public Socket AcceptSocket ()
 185                 {
 186                         if (!active)
 187                                 throw new InvalidOperationException ("Socket is not listening");
 188
 189                         return server.Accept();
 190                 }
 191
 192                 /// <summary>
 193                 /// Accepts a pending connection
 194                 /// </summary>
 195                 /// <returns>A TcpClient
 196                 /// object made from the new socket.</returns>
 197                 public TcpClient AcceptTcpClient ()
 198                 {
 199                         if (!active)
 200                                 throw new InvalidOperationException ("Socket is not listening");
 201
 202                         Socket clientSocket = server.Accept ();
 203
 204                         TcpClient client = new TcpClient(clientSocket);
 205
 206                         return client;
 207                 }
 208
 209                 /// <summary>
 210                 /// Destructor - stops the listener listening
 211                 /// </summary>
 212                 ~TcpListener ()
 213                 {
 214                         if (active)
 215                                 Stop();
 216                 }
 217
 218                 /// <returns>
 219                 /// Returns 'true' if there is a connection waiting to be accepted
 220                 /// with AcceptSocket() or AcceptTcpClient().
 221                 /// </returns>
 222                 public bool Pending ()
 223                 {
 224                         if (!active)
 225                                 throw new InvalidOperationException ("Socket is not listening");
 226
 227                         return server.Poll(0, SelectMode.SelectRead);
 228                 }
 229
 230                 /// <summary>
 231                 /// Tells the TcpListener to start listening.
 232                 /// </summary>
 233                 public void Start ()
 234                 {
 235                         // MS: sets Listen to Int32.MaxValue
 236                         this.Start (5);
 237                         // According to the man page some BSD and BSD-derived
 238                         // systems limit the backlog to 5.  This should really be
 239                         // configurable though
 240                 }
 241
 242                 /// <summary>
 243                 /// Tells the TcpListener to start listening for max number
 244                 /// of pending connections.
 245                 /// </summary>
 246
 247                 public void Start (int backlog)
 248                 {
 249                         if (active) {
 250                                 return;
 251                         }
 252                         if (server == null) {
 253                                 throw new InvalidOperationException ("Invalid server socket");
 254                         }
 255
 256                         server.Bind (savedEP);
 257                         server.Listen (backlog);
 258                         active = true;
 259                 }
 260
 261                 public IAsyncResult BeginAcceptSocket (AsyncCallback callback,
 262                                                        object state)
 263                 {
 264                         if (server == null) {
 265                                 throw new ObjectDisposedException (GetType ().ToString ());
 266                         }
 267
 268                         return(server.BeginAccept (callback, state));
 269                 }
 270
 271                 public IAsyncResult BeginAcceptTcpClient (AsyncCallback callback, object state)
 272                 {
 273                         if (server == null) {
 274                                 throw new ObjectDisposedException (GetType ().ToString ());
 275                         }
 276
 277                         return(server.BeginAccept (callback, state));
 278                 }
 279
 280                 public Socket EndAcceptSocket (IAsyncResult asyncResult)
 281                 {
 282                         return(server.EndAccept (asyncResult));
 283                 }
 284
 285                 public TcpClient EndAcceptTcpClient (IAsyncResult asyncResult)
 286                 {
 287                         Socket clientSocket = server.EndAccept (asyncResult);
 288                         TcpClient client = new TcpClient (clientSocket);
 289
 290                         return(client);
 291                 }
 292
 293                 /// <summary>
 294                 /// Tells the TcpListener to stop listening and dispose
 295                 /// of all managed resources.
 296                 /// </summary>
 297                 public void Stop ()
 298                 {
 299                         if (active)
 300                         {
 301                                 server.Close ();
 302                                 server = null;
 303                         }
 304
 305                         Init (AddressFamily.InterNetwork, savedEP);
 306                 }
 307
 308 #if NET_4_5
 309                 public Task<Socket> AcceptSocketAsync ()
 310                 {
 311                         return Task<Socket>.Factory.FromAsync (BeginAcceptSocket, EndAcceptSocket, null);
 312                 }
 313
 314                 public Task<TcpClient> AcceptTcpClientAsync ()
 315                 {
 316                         return Task<TcpClient>.Factory.FromAsync (BeginAcceptTcpClient, EndAcceptTcpClient, null);
 317                 }
 318 #endif
 319         }
 320 }