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                 public bool ExclusiveAddressUse
 152                 {
 153                         get {
 154                                 if (server == null) {
 155                                         throw new ObjectDisposedException (GetType ().ToString ());
 156                                 }
 157                                 if (active) {
 158                                         throw new InvalidOperationException ("The TcpListener has been started");
 159                                 }
 160
 161                                 return(server.ExclusiveAddressUse);
 162                         }
 163                         set {
 164                                 if (server == null) {
 165                                         throw new ObjectDisposedException (GetType ().ToString ());
 166                                 }
 167                                 if (active) {
 168                                         throw new InvalidOperationException ("The TcpListener has been started");
 169                                 }
 170
 171                                 server.ExclusiveAddressUse = value;
 172                         }
 173                 }
 174
 175                 // methods
 176
 177                 /// <summary>
 178                 /// Accepts a pending connection
 179                 /// </summary>
 180                 /// <returns>A Socket object for the new connection</returns>
 181                 public Socket AcceptSocket ()
 182                 {
 183                         if (!active)
 184                                 throw new InvalidOperationException ("Socket is not listening");
 185
 186                         return server.Accept();
 187                 }
 188
 189                 /// <summary>
 190                 /// Accepts a pending connection
 191                 /// </summary>
 192                 /// <returns>A TcpClient
 193                 /// object made from the new socket.</returns>
 194                 public TcpClient AcceptTcpClient ()
 195                 {
 196                         if (!active)
 197                                 throw new InvalidOperationException ("Socket is not listening");
 198
 199                         Socket clientSocket = server.Accept ();
 200
 201                         TcpClient client = new TcpClient(clientSocket);
 202
 203                         return client;
 204                 }
 205
 206                 /// <summary>
 207                 /// Destructor - stops the listener listening
 208                 /// </summary>
 209                 ~TcpListener ()
 210                 {
 211                         if (active)
 212                                 Stop();
 213                 }
 214
 215                 /// <returns>
 216                 /// Returns 'true' if there is a connection waiting to be accepted
 217                 /// with AcceptSocket() or AcceptTcpClient().
 218                 /// </returns>
 219                 public bool Pending ()
 220                 {
 221                         if (!active)
 222                                 throw new InvalidOperationException ("Socket is not listening");
 223
 224                         return server.Poll(0, SelectMode.SelectRead);
 225                 }
 226
 227                 /// <summary>
 228                 /// Tells the TcpListener to start listening.
 229                 /// </summary>
 230                 public void Start ()
 231                 {
 232                         // MS: sets Listen to Int32.MaxValue
 233                         this.Start (5);
 234                         // According to the man page some BSD and BSD-derived
 235                         // systems limit the backlog to 5.  This should really be
 236                         // configurable though
 237                 }
 238
 239                 /// <summary>
 240                 /// Tells the TcpListener to start listening for max number
 241                 /// of pending connections.
 242                 /// </summary>
 243
 244                 public void Start (int backlog)
 245                 {
 246                         if (active) {
 247                                 return;
 248                         }
 249                         if (server == null) {
 250                                 throw new InvalidOperationException ("Invalid server socket");
 251                         }
 252
 253                         server.Bind (savedEP);
 254                         server.Listen (backlog);
 255                         active = true;
 256                 }
 257
 258                 public IAsyncResult BeginAcceptSocket (AsyncCallback callback,
 259                                                        object state)
 260                 {
 261                         if (server == null) {
 262                                 throw new ObjectDisposedException (GetType ().ToString ());
 263                         }
 264
 265                         return(server.BeginAccept (callback, state));
 266                 }
 267
 268                 public IAsyncResult BeginAcceptTcpClient (AsyncCallback callback, object state)
 269                 {
 270                         if (server == null) {
 271                                 throw new ObjectDisposedException (GetType ().ToString ());
 272                         }
 273
 274                         return(server.BeginAccept (callback, state));
 275                 }
 276
 277                 public Socket EndAcceptSocket (IAsyncResult asyncResult)
 278                 {
 279                         return(server.EndAccept (asyncResult));
 280                 }
 281
 282                 public TcpClient EndAcceptTcpClient (IAsyncResult asyncResult)
 283                 {
 284                         Socket clientSocket = server.EndAccept (asyncResult);
 285                         TcpClient client = new TcpClient (clientSocket);
 286
 287                         return(client);
 288                 }
 289
 290                 /// <summary>
 291                 /// Tells the TcpListener to stop listening and dispose
 292                 /// of all managed resources.
 293                 /// </summary>
 294                 public void Stop ()
 295                 {
 296                         if (active)
 297                         {
 298                                 server.Close ();
 299                                 server = null;
 300                         }
 301
 302                         Init (AddressFamily.InterNetwork, savedEP);
 303                 }
 304
 305 #if NET_4_5
 306                 public Task<Socket> AcceptSocketAsync ()
 307                 {
 308                         return Task<Socket>.Factory.FromAsync (BeginAcceptSocket, EndAcceptSocket, null);
 309                 }
 310
 311                 public Task<TcpClient> AcceptTcpClientAsync ()
 312                 {
 313                         return Task<TcpClient>.Factory.FromAsync (BeginAcceptTcpClient, EndAcceptTcpClient, null);
 314                 }
 315 #endif
 316         }
 317 }