mcs/class/System/System.Net/Dns.cs

   1 // System.Net.Dns.cs
   2 //
   3 // Authors:
   4 //      Mads Pultz (mpultz@diku.dk)
   5 //      Lawrence Pit (loz@cable.a2000.nl)
   6
   7 // Author: Mads Pultz (mpultz@diku.dk)
   8 //         Lawrence Pit (loz@cable.a2000.nl)
   9 //         Marek Safar (marek.safar@gmail.com)
  10 //         Gonzalo Paniagua Javier (gonzalo.mono@gmail.com)
  11 //
  12 // (C) Mads Pultz, 2001
  13 // Copyright (c) 2011 Novell, Inc.
  14 // Copyright (c) 2011 Xamarin, Inc.
  15
  16 //
  17 // Permission is hereby granted, free of charge, to any person obtaining
  18 // a copy of this software and associated documentation files (the
  19 // "Software"), to deal in the Software without restriction, including
  20 // without limitation the rights to use, copy, modify, merge, publish,
  21 // distribute, sublicense, and/or sell copies of the Software, and to
  22 // permit persons to whom the Software is furnished to do so, subject to
  23 // the following conditions:
  24 //
  25 // The above copyright notice and this permission notice shall be
  26 // included in all copies or substantial portions of the Software.
  27 //
  28 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  29 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  30 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  31 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  32 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  33 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  34 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  35 //
  36
  37 using System;
  38 using System.Net.Sockets;
  39 using System.Text;
  40 using System.Collections;
  41 using System.Threading;
  42 using System.Runtime.CompilerServices;
  43 using System.Runtime.Remoting.Messaging;
  44 #if NET_4_5
  45 using System.Threading.Tasks;
  46 #endif
  47
  48 #if !MOBILE
  49 using Mono.Net.Dns;
  50 #endif
  51
  52 namespace System.Net {
  53         public static class Dns {
  54 #if !MOBILE
  55                 static bool use_mono_dns;
  56                 static SimpleResolver resolver;
  57 #endif
  58
  59                 static Dns ()
  60                 {
  61                         System.Net.Sockets.Socket.CheckProtocolSupport();
  62
  63 #if !MOBILE
  64                         if (Environment.GetEnvironmentVariable ("MONO_DNS") != null) {
  65                                 resolver = new SimpleResolver ();
  66                                 use_mono_dns = true;
  67                         }
  68 #endif
  69                 }
  70
  71 #if !MOBILE
  72                 internal static bool UseMonoDns {
  73                         get { return use_mono_dns; }
  74                 }
  75 #endif
  76
  77                 private delegate IPHostEntry GetHostByNameCallback (string hostName);
  78                 private delegate IPHostEntry ResolveCallback (string hostName);
  79                 private delegate IPHostEntry GetHostEntryNameCallback (string hostName);
  80                 private delegate IPHostEntry GetHostEntryIPCallback (IPAddress hostAddress);
  81                 private delegate IPAddress [] GetHostAddressesCallback (string hostName);
  82
  83 #if !MOBILE
  84                 static void OnCompleted (object sender, SimpleResolverEventArgs e)
  85                 {
  86                         DnsAsyncResult ares = (DnsAsyncResult) e.UserToken;
  87                         IPHostEntry entry = e.HostEntry;
  88                         if (entry == null || e.ResolverError != 0) {
  89                                 ares.SetCompleted (false, new Exception ("Error: " + e.ResolverError));
  90                                 return;
  91                         }
  92                         ares.SetCompleted (false, entry);
  93                 }
  94
  95                 static IAsyncResult BeginAsyncCallAddresses (string host, AsyncCallback callback, object state)
  96                 {
  97                         SimpleResolverEventArgs e = new SimpleResolverEventArgs ();
  98                         e.Completed += OnCompleted;
  99                         e.HostName = host;
 100                         DnsAsyncResult ares = new DnsAsyncResult (callback, state);
 101                         e.UserToken = ares;
 102                         if (resolver.GetHostAddressesAsync (e) == false)
 103                                 ares.SetCompleted (true, e.HostEntry); // Completed synchronously
 104                         return ares;
 105                 }
 106
 107                 static IAsyncResult BeginAsyncCall (string host, AsyncCallback callback, object state)
 108                 {
 109                         SimpleResolverEventArgs e = new SimpleResolverEventArgs ();
 110                         e.Completed += OnCompleted;
 111                         e.HostName = host;
 112                         DnsAsyncResult ares = new DnsAsyncResult (callback, state);
 113                         e.UserToken = ares;
 114                         if (resolver.GetHostEntryAsync (e) == false)
 115                                 ares.SetCompleted (true, e.HostEntry); // Completed synchronously
 116                         return ares;
 117                 }
 118
 119                 static IPHostEntry EndAsyncCall (DnsAsyncResult ares)
 120                 {
 121                         if (ares == null)
 122                                 throw new ArgumentException ("Invalid asyncResult");
 123                         if (!ares.IsCompleted)
 124                                 ares.AsyncWaitHandle.WaitOne ();
 125                         if (ares.Exception != null)
 126                                 throw ares.Exception;
 127                         IPHostEntry entry = ares.HostEntry;
 128                         if (entry == null || entry.AddressList == null || entry.AddressList.Length == 0)
 129                                 Error_11001 (entry.HostName);
 130                         return entry;
 131                 }
 132 #endif
 133
 134                 [Obsolete ("Use BeginGetHostEntry instead")]
 135                 public static IAsyncResult BeginGetHostByName (string hostName, AsyncCallback requestCallback, object stateObject)
 136                 {
 137                         if (hostName == null)
 138                                 throw new ArgumentNullException ("hostName");
 139
 140 #if !MOBILE
 141                         if (use_mono_dns)
 142                                 return BeginAsyncCall (hostName, requestCallback, stateObject);
 143 #endif
 144
 145                         GetHostByNameCallback c = new GetHostByNameCallback (GetHostByName);
 146                         return c.BeginInvoke (hostName, requestCallback, stateObject);
 147                 }
 148
 149                 [Obsolete ("Use BeginGetHostEntry instead")]
 150                 public static IAsyncResult BeginResolve (string hostName, AsyncCallback requestCallback, object stateObject)
 151                 {
 152                         if (hostName == null)
 153                                 throw new ArgumentNullException ("hostName");
 154
 155 #if !MOBILE
 156                         if (use_mono_dns)
 157                                 return BeginAsyncCall (hostName, requestCallback, stateObject);
 158 #endif
 159
 160                         ResolveCallback c = new ResolveCallback (Resolve);
 161                         return c.BeginInvoke (hostName, requestCallback, stateObject);
 162                 }
 163
 164                 public static IAsyncResult BeginGetHostAddresses (string hostNameOrAddress, AsyncCallback requestCallback, object state)
 165                 {
 166                         if (hostNameOrAddress == null)
 167                                 throw new ArgumentNullException ("hostName");
 168                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 169                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 170                                         "and ::0 (IPv6) are unspecified addresses. You " +
 171                                         "cannot use them as target address.",
 172                                         "hostNameOrAddress");
 173
 174 #if !MOBILE
 175                         if (use_mono_dns)
 176                                 return BeginAsyncCallAddresses (hostNameOrAddress, requestCallback, state);
 177 #endif
 178
 179                         GetHostAddressesCallback c = new GetHostAddressesCallback (GetHostAddresses);
 180                         return c.BeginInvoke (hostNameOrAddress, requestCallback, state);
 181                 }
 182
 183                 public static IAsyncResult BeginGetHostEntry (string hostNameOrAddress, AsyncCallback requestCallback, object stateObject)
 184                 {
 185                         if (hostNameOrAddress == null)
 186                                 throw new ArgumentNullException ("hostName");
 187                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 188                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 189                                         "and ::0 (IPv6) are unspecified addresses. You " +
 190                                         "cannot use them as target address.",
 191                                         "hostNameOrAddress");
 192
 193 #if !MOBILE
 194                         if (use_mono_dns)
 195                                 return BeginAsyncCall (hostNameOrAddress, requestCallback, stateObject);
 196 #endif
 197
 198                         GetHostEntryNameCallback c = new GetHostEntryNameCallback (GetHostEntry);
 199                         return c.BeginInvoke (hostNameOrAddress, requestCallback, stateObject);
 200                 }
 201
 202                 public static IAsyncResult BeginGetHostEntry (IPAddress address, AsyncCallback requestCallback, object stateObject)
 203                 {
 204                         if (address == null)
 205                                 throw new ArgumentNullException ("address");
 206
 207 #if !MOBILE
 208                         if (use_mono_dns)
 209                                 return BeginAsyncCall (address.ToString (), requestCallback, stateObject);
 210 #endif
 211
 212                         GetHostEntryIPCallback c = new GetHostEntryIPCallback (GetHostEntry);
 213                         return c.BeginInvoke (address, requestCallback, stateObject);
 214                 }
 215
 216                 [Obsolete ("Use EndGetHostEntry instead")]
 217                 public static IPHostEntry EndGetHostByName (IAsyncResult asyncResult)
 218                 {
 219                         if (asyncResult == null)
 220                                 throw new ArgumentNullException ("asyncResult");
 221
 222 #if !MOBILE
 223                         if (use_mono_dns)
 224                                 return EndAsyncCall (asyncResult as DnsAsyncResult);
 225 #endif
 226
 227                         AsyncResult async = (AsyncResult) asyncResult;
 228                         GetHostByNameCallback cb = (GetHostByNameCallback) async.AsyncDelegate;
 229                         return cb.EndInvoke(asyncResult);
 230                 }
 231
 232                 [Obsolete ("Use EndGetHostEntry instead")]
 233                 public static IPHostEntry EndResolve (IAsyncResult asyncResult)
 234                 {
 235                         if (asyncResult == null)
 236                                 throw new ArgumentNullException ("asyncResult");
 237
 238 #if !MOBILE
 239                         if (use_mono_dns)
 240                                 return EndAsyncCall (asyncResult as DnsAsyncResult);
 241 #endif
 242
 243                         AsyncResult async = (AsyncResult) asyncResult;
 244                         ResolveCallback cb = (ResolveCallback) async.AsyncDelegate;
 245                         return cb.EndInvoke(asyncResult);
 246                 }
 247
 248                 public static IPAddress [] EndGetHostAddresses (IAsyncResult asyncResult)
 249                 {
 250                         if (asyncResult == null)
 251                                 throw new ArgumentNullException ("asyncResult");
 252
 253 #if !MOBILE
 254                         if (use_mono_dns) {
 255                                 IPHostEntry entry = EndAsyncCall (asyncResult as DnsAsyncResult);
 256                                 if (entry == null)
 257                                         return null;
 258                                 return entry.AddressList;
 259                         }
 260 #endif
 261
 262                         AsyncResult async = (AsyncResult) asyncResult;
 263                         GetHostAddressesCallback cb = (GetHostAddressesCallback) async.AsyncDelegate;
 264                         return cb.EndInvoke(asyncResult);
 265                 }
 266
 267                 public static IPHostEntry EndGetHostEntry (IAsyncResult asyncResult)
 268                 {
 269                         if (asyncResult == null)
 270                                 throw new ArgumentNullException ("asyncResult");
 271
 272 #if !MOBILE
 273                         if (use_mono_dns)
 274                                 return EndAsyncCall (asyncResult as DnsAsyncResult);
 275 #endif
 276
 277                         AsyncResult async = (AsyncResult) asyncResult;
 278                         if (async.AsyncDelegate is GetHostEntryIPCallback)
 279                                 return ((GetHostEntryIPCallback) async.AsyncDelegate).EndInvoke (asyncResult);
 280                         GetHostEntryNameCallback cb = (GetHostEntryNameCallback) async.AsyncDelegate;
 281                         return cb.EndInvoke(asyncResult);
 282                 }
 283
 284
 285 #if !TARGET_JVM
 286                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 287                 private extern static bool GetHostByName_internal(string host, out string h_name, out string[] h_aliases, out string[] h_addr_list);
 288
 289                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 290                 private extern static bool GetHostByAddr_internal(string addr, out string h_name, out string[] h_aliases, out string[] h_addr_list);
 291
 292                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 293                 private extern static bool GetHostName_internal(out string h_name);
 294 #endif
 295
 296                 static void Error_11001 (string hostName)
 297                 {
 298                         throw new SocketException(11001, string.Format ("Could not resolve host '{0}'", hostName));
 299
 300                 }
 301
 302                 private static IPHostEntry hostent_to_IPHostEntry(string originalHostName, string h_name, string[] h_aliases, string[] h_addrlist)
 303                 {
 304                         IPHostEntry he = new IPHostEntry();
 305                         ArrayList addrlist = new ArrayList();
 306
 307                         he.HostName = h_name;
 308                         he.Aliases = h_aliases;
 309                         for(int i=0; i<h_addrlist.Length; i++) {
 310                                 try {
 311                                         IPAddress newAddress = IPAddress.Parse(h_addrlist[i]);
 312
 313                                         if( (Socket.SupportsIPv6 && newAddress.AddressFamily == AddressFamily.InterNetworkV6) ||
 314                                             (Socket.SupportsIPv4 && newAddress.AddressFamily == AddressFamily.InterNetwork) )
 315                                                 addrlist.Add(newAddress);
 316                                 } catch (ArgumentNullException) {
 317                                         /* Ignore this, as the
 318                                          * internal call might have
 319                                          * left some blank entries at
 320                                          * the end of the array
 321                                          */
 322                                 }
 323                         }
 324
 325                         if(addrlist.Count == 0)
 326                                 Error_11001 (originalHostName);
 327
 328                         he.AddressList = addrlist.ToArray(typeof(IPAddress)) as IPAddress[];
 329                         return he;
 330                 }
 331
 332                 [Obsolete ("Use GetHostEntry instead")]
 333                 public static IPHostEntry GetHostByAddress(IPAddress address)
 334                 {
 335                         if (address == null)
 336                                 throw new ArgumentNullException ("address");
 337
 338                         return GetHostByAddressFromString (address.ToString (), false);
 339                 }
 340
 341                 [Obsolete ("Use GetHostEntry instead")]
 342                 public static IPHostEntry GetHostByAddress(string address)
 343                 {
 344                         if (address == null)
 345                                 throw new ArgumentNullException ("address");
 346
 347                         return GetHostByAddressFromString (address, true);
 348                 }
 349
 350                 static IPHostEntry GetHostByAddressFromString (string address, bool parse)
 351                 {
 352                         // Undocumented MS behavior: when called with IF_ANY,
 353                         // this should return the local host
 354                         if (address.Equals ("0.0.0.0")) {
 355                                 address = "127.0.0.1";
 356                                 parse = false;
 357                         }
 358
 359                         // Must check the IP format, might send an exception if invalid string.
 360                         if (parse)
 361                                 IPAddress.Parse (address);
 362
 363                         string h_name;
 364                         string[] h_aliases, h_addrlist;
 365 #if TARGET_JVM
 366                         h_name = null;
 367                         h_aliases = null;
 368                         h_addrlist = null;
 369                         try {
 370                                 java.net.InetAddress[] iaArr =
 371                                         java.net.InetAddress.getAllByName(address);
 372                                 if (iaArr != null && iaArr.Length > 0)
 373                                     h_name = iaArr[0].getHostName();
 374                                 if (iaArr != null && iaArr.Length > 0)
 375                                 {
 376                                     h_addrlist = new String[iaArr.Length];
 377                                     for (int i = 0; i < h_addrlist.Length; i++)
 378                                         h_addrlist[i] = iaArr[i].getHostAddress();
 379                                 }
 380                         } catch (java.net.UnknownHostException jUHE) {
 381                                 throw new SocketException((int)SocketError.HostNotFound, jUHE.Message);
 382                         }
 383 #else
 384                         bool ret = GetHostByAddr_internal(address, out h_name, out h_aliases, out h_addrlist);
 385                         if (!ret)
 386                                 Error_11001 (address);
 387 #endif
 388                         return (hostent_to_IPHostEntry (address, h_name, h_aliases, h_addrlist));
 389
 390                 }
 391
 392                 public static IPHostEntry GetHostEntry (string hostNameOrAddress)
 393                 {
 394                         if (hostNameOrAddress == null)
 395                                 throw new ArgumentNullException ("hostNameOrAddress");
 396                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 397                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 398                                         "and ::0 (IPv6) are unspecified addresses. You " +
 399                                         "cannot use them as target address.",
 400                                         "hostNameOrAddress");
 401
 402                         IPAddress addr;
 403                         if (hostNameOrAddress.Length > 0 && IPAddress.TryParse (hostNameOrAddress, out addr))
 404                                 return GetHostEntry (addr);
 405
 406                         return GetHostByName (hostNameOrAddress);
 407                 }
 408
 409                 public static IPHostEntry GetHostEntry (IPAddress address)
 410                 {
 411                         if (address == null)
 412                                 throw new ArgumentNullException ("address");
 413
 414                         return GetHostByAddressFromString (address.ToString (), false);
 415                 }
 416
 417                 public static IPAddress [] GetHostAddresses (string hostNameOrAddress)
 418                 {
 419                         if (hostNameOrAddress == null)
 420                                 throw new ArgumentNullException ("hostNameOrAddress");
 421
 422                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 423                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 424                                         "and ::0 (IPv6) are unspecified addresses. You " +
 425                                         "cannot use them as target address.",
 426                                         "hostNameOrAddress");
 427
 428                         IPAddress addr;
 429                         if (hostNameOrAddress.Length > 0 && IPAddress.TryParse (hostNameOrAddress, out addr))
 430                                 return new IPAddress[1] { addr };
 431
 432                         return GetHostEntry (hostNameOrAddress).AddressList;
 433                 }
 434
 435                 [Obsolete ("Use GetHostEntry instead")]
 436                 public static IPHostEntry GetHostByName (string hostName)
 437                 {
 438                         if (hostName == null)
 439                                 throw new ArgumentNullException ("hostName");
 440 #if TARGET_JVM
 441                         if (hostName.Length == 0)
 442                                 hostName = "localhost";
 443                         try {
 444                                 java.net.InetAddress[] iaArr = java.net.InetAddress.getAllByName(hostName);
 445                                 IPHostEntry host = new IPHostEntry();
 446                                 if (iaArr != null && iaArr.Length > 0)
 447                                 {
 448                                         host.HostName = iaArr[0].getHostName();
 449                                         IPAddress[] ipArr = new IPAddress[iaArr.Length];
 450                                         for (int i = 0; i < iaArr.Length; i++)
 451                                                 ipArr[i] = IPAddress.Parse(iaArr[i].getHostAddress());
 452
 453                                         host.AddressList = ipArr;
 454                                 }
 455                                 return host;
 456                         } catch (java.net.UnknownHostException jUHE) {
 457                                 throw new SocketException((int)SocketError.HostNotFound, jUHE.Message);
 458                         }
 459 #else
 460                         string h_name;
 461                         string[] h_aliases, h_addrlist;
 462
 463                         bool ret = GetHostByName_internal(hostName, out h_name, out h_aliases, out h_addrlist);
 464                         if (ret == false)
 465                                 Error_11001 (hostName);
 466
 467                         return(hostent_to_IPHostEntry(hostName, h_name, h_aliases, h_addrlist));
 468 #endif
 469                 }
 470
 471                 public static string GetHostName ()
 472                 {
 473 #if TARGET_JVM
 474                         return java.net.InetAddress.getLocalHost ().getHostName ();
 475 #else
 476                         string hostName;
 477
 478                         bool ret = GetHostName_internal(out hostName);
 479
 480                         if (ret == false)
 481                                 Error_11001 (hostName);
 482
 483                         return hostName;
 484 #endif
 485                 }
 486
 487                 [Obsolete ("Use GetHostEntry instead")]
 488                 public static IPHostEntry Resolve(string hostName)
 489                 {
 490                         if (hostName == null)
 491                                 throw new ArgumentNullException ("hostName");
 492
 493                         IPHostEntry ret = null;
 494
 495                         try {
 496                                 ret =  GetHostByAddress(hostName);
 497                         }
 498                         catch{}
 499
 500                         if(ret == null)
 501                                 ret =  GetHostByName(hostName);
 502
 503                         return ret;
 504                 }
 505
 506 #if NET_4_5
 507                 public static Task<IPAddress[]> GetHostAddressesAsync (string hostNameOrAddress)
 508                 {
 509                         return Task<IPAddress[]>.Factory.FromAsync (BeginGetHostAddresses, EndGetHostAddresses, hostNameOrAddress, null);
 510                 }
 511
 512                 public static Task<IPHostEntry> GetHostEntryAsync (IPAddress address)
 513                 {
 514                         return Task<IPHostEntry>.Factory.FromAsync (BeginGetHostEntry, EndGetHostEntry, address, null);
 515                 }
 516
 517                 public static Task<IPHostEntry> GetHostEntryAsync (string hostNameOrAddress)
 518                 {
 519                         return Task<IPHostEntry>.Factory.FromAsync (BeginGetHostEntry, EndGetHostEntry, hostNameOrAddress, null);
 520                 }
 521 #endif
 522         }
 523 }
 524