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 using System.Threading.Tasks;
  42
  43 namespace System.Net.Sockets
  44 {
  45         /// <remarks>
  46         /// A slightly more abstracted way to listen for incoming
  47         /// network connections than a Socket.
  48         /// </remarks>
  49         public class TcpListener
  50         {
  51                 // private data
  52
  53                 bool active;
  54                 Socket server;
  55                 EndPoint savedEP;
  56
  57                 // constructor
  58
  59                 /// <summary>
  60                 /// Some code that is shared between the constructors.
  61                 /// </summary>
  62                 private void Init (AddressFamily family, EndPoint ep)
  63                 {
  64                         active = false;
  65                         server = new Socket(family, SocketType.Stream, ProtocolType.Tcp);
  66                         savedEP = ep;
  67                 }
  68
  69                 /// <summary>
  70                 /// Constructs a new TcpListener to listen on a specified port
  71                 /// </summary>
  72                 /// <param name="port">The port to listen on, e.g. 80 if you
  73                 /// are a web server</param>
  74                 [Obsolete ("Use TcpListener (IPAddress address, int port) instead")]
  75                 public TcpListener (int port)
  76                 {
  77                         if (port < 0 || port > 65535)
  78                                 throw new ArgumentOutOfRangeException ("port");
  79
  80                         Init (AddressFamily.InterNetwork, new IPEndPoint (IPAddress.Any, port));
  81                 }
  82
  83                 /// <summary>
  84                 /// Constructs a new TcpListener with a specified local endpoint
  85                 /// </summary>
  86                 /// <param name="local_end_point">The endpoint</param>
  87                 public TcpListener (IPEndPoint localEP)
  88                 {
  89                         if (localEP == null)
  90                                 throw new ArgumentNullException ("localEP");
  91
  92                         Init (localEP.AddressFamily, localEP);
  93                 }
  94
  95                 /// <summary>
  96                 /// Constructs a new TcpListener, listening on a specified port
  97                 /// and IP (for use on a multi-homed machine)
  98                 /// </summary>
  99                 /// <param name="listen_ip">The IP to listen on</param>
 100                 /// <param name="port">The port to listen on</param>
 101                 public TcpListener (IPAddress localaddr, int port)
 102                 {
 103                         if (localaddr == null)
 104                                 throw new ArgumentNullException ("localaddr");
 105
 106                         if (port < 0 || port > 65535)
 107                                 throw new ArgumentOutOfRangeException ("port");
 108
 109                         Init (localaddr.AddressFamily, new IPEndPoint (localaddr, port));
 110                 }
 111
 112
 113                 // properties
 114
 115                 /// <summary>
 116                 /// A flag that is 'true' if the TcpListener is listening,
 117                 /// or 'false' if it is not listening
 118                 /// </summary>
 119                 protected bool Active
 120                 {
 121                         get { return active; }
 122                 }
 123
 124                 /// <summary>
 125                 /// The local end point
 126                 /// </summary>
 127                 public EndPoint LocalEndpoint
 128                 {
 129                         get {
 130                                 if (active)
 131                                         return server.LocalEndPoint;
 132
 133                                 return savedEP;
 134                         }
 135                 }
 136
 137                 /// <summary>
 138                 /// The listening socket
 139                 /// </summary>
 140                 public Socket Server
 141                 {
 142                         get { return server; }
 143                 }
 144
 145                 /// <summary>
 146                 /// Specifies whether the TcpListener allows only one
 147                 /// underlying socket to listen to a specific port
 148                 /// </summary>
 149                 public bool ExclusiveAddressUse
 150                 {
 151                         get {
 152                                 if (server == null) {
 153                                         throw new ObjectDisposedException (GetType ().ToString ());
 154                                 }
 155                                 if (active) {
 156                                         throw new InvalidOperationException ("The TcpListener has been started");
 157                                 }
 158
 159                                 return(server.ExclusiveAddressUse);
 160                         }
 161                         set {
 162                                 if (server == null) {
 163                                         throw new ObjectDisposedException (GetType ().ToString ());
 164                                 }
 165                                 if (active) {
 166                                         throw new InvalidOperationException ("The TcpListener has been started");
 167                                 }
 168
 169                                 server.ExclusiveAddressUse = value;
 170                         }
 171                 }
 172
 173                 // methods
 174
 175                 /// <summary>
 176                 /// Accepts a pending connection
 177                 /// </summary>
 178                 /// <returns>A Socket object for the new connection</returns>
 179                 public Socket AcceptSocket ()
 180                 {
 181                         if (!active)
 182                                 throw new InvalidOperationException ("Socket is not listening");
 183
 184                         return server.Accept();
 185                 }
 186
 187                 /// <summary>
 188                 /// Accepts a pending connection
 189                 /// </summary>
 190                 /// <returns>A TcpClient
 191                 /// object made from the new socket.</returns>
 192                 public TcpClient AcceptTcpClient ()
 193                 {
 194                         if (!active)
 195                                 throw new InvalidOperationException ("Socket is not listening");
 196
 197                         Socket clientSocket = server.Accept ();
 198
 199                         TcpClient client = new TcpClient(clientSocket);
 200
 201                         return client;
 202                 }
 203
 204                 public void AllowNatTraversal (bool allowed)
 205                 {
 206                         if (active)
 207                                 throw new InvalidOperationException (SR.GetString (SR.net_tcplistener_mustbestopped));
 208
 209                         if (allowed)
 210                                 server.SetIPProtectionLevel (IPProtectionLevel.Unrestricted);
 211                         else
 212                                 server.SetIPProtectionLevel (IPProtectionLevel.EdgeRestricted);
 213                 }
 214
 215                 public static TcpListener Create (int port)
 216                 {
 217                         if (port < 0 || port > 65535)
 218                                 throw new ArgumentOutOfRangeException ("port");
 219
 220                         TcpListener listener = new TcpListener (IPAddress.IPv6Any, port);
 221                         listener.Server.DualMode = true;
 222
 223                         return listener;
 224                 }
 225
 226                 /// <summary>
 227                 /// Destructor - stops the listener listening
 228                 /// </summary>
 229                 ~TcpListener ()
 230                 {
 231                         if (active)
 232                                 Stop();
 233                 }
 234
 235                 /// <returns>
 236                 /// Returns 'true' if there is a connection waiting to be accepted
 237                 /// with AcceptSocket() or AcceptTcpClient().
 238                 /// </returns>
 239                 public bool Pending ()
 240                 {
 241                         if (!active)
 242                                 throw new InvalidOperationException ("Socket is not listening");
 243
 244                         return server.Poll(0, SelectMode.SelectRead);
 245                 }
 246
 247                 /// <summary>
 248                 /// Tells the TcpListener to start listening.
 249                 /// </summary>
 250                 public void Start ()
 251                 {
 252                         // MS: sets Listen to Int32.MaxValue
 253                         this.Start (5);
 254                         // According to the man page some BSD and BSD-derived
 255                         // systems limit the backlog to 5.  This should really be
 256                         // configurable though
 257                 }
 258
 259                 /// <summary>
 260                 /// Tells the TcpListener to start listening for max number
 261                 /// of pending connections.
 262                 /// </summary>
 263
 264                 public void Start (int backlog)
 265                 {
 266                         if (active) {
 267                                 return;
 268                         }
 269                         if (server == null) {
 270                                 throw new InvalidOperationException ("Invalid server socket");
 271                         }
 272
 273                         server.Bind (savedEP);
 274                         server.Listen (backlog);
 275                         active = true;
 276                 }
 277
 278                 public IAsyncResult BeginAcceptSocket (AsyncCallback callback,
 279                                                        object state)
 280                 {
 281                         if (server == null) {
 282                                 throw new ObjectDisposedException (GetType ().ToString ());
 283                         }
 284
 285                         return(server.BeginAccept (callback, state));
 286                 }
 287
 288                 public IAsyncResult BeginAcceptTcpClient (AsyncCallback callback, object state)
 289                 {
 290                         if (server == null) {
 291                                 throw new ObjectDisposedException (GetType ().ToString ());
 292                         }
 293
 294                         return(server.BeginAccept (callback, state));
 295                 }
 296
 297                 public Socket EndAcceptSocket (IAsyncResult asyncResult)
 298                 {
 299                         return(server.EndAccept (asyncResult));
 300                 }
 301
 302                 public TcpClient EndAcceptTcpClient (IAsyncResult asyncResult)
 303                 {
 304                         Socket clientSocket = server.EndAccept (asyncResult);
 305                         TcpClient client = new TcpClient (clientSocket);
 306
 307                         return(client);
 308                 }
 309
 310                 /// <summary>
 311                 /// Tells the TcpListener to stop listening and dispose
 312                 /// of all managed resources.
 313                 /// </summary>
 314                 public void Stop ()
 315                 {
 316                         if (active)
 317                         {
 318                                 server.Close ();
 319                                 server = null;
 320                         }
 321
 322                         Init (AddressFamily.InterNetwork, savedEP);
 323                 }
 324
 325                 public Task<Socket> AcceptSocketAsync ()
 326                 {
 327                         return Task<Socket>.Factory.FromAsync (BeginAcceptSocket, EndAcceptSocket, null);
 328                 }
 329
 330                 public Task<TcpClient> AcceptTcpClientAsync ()
 331                 {
 332                         return Task<TcpClient>.Factory.FromAsync (BeginAcceptTcpClient, EndAcceptTcpClient, null);
 333                 }
 334         }
 335 }