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 using System.Threading.Tasks;
  45
  46 #if !MOBILE
  47 using Mono.Net.Dns;
  48 #endif
  49
  50 namespace System.Net {
  51         public static class Dns {
  52 #if !MOBILE
  53                 static bool use_mono_dns;
  54                 static SimpleResolver resolver;
  55 #endif
  56
  57                 static Dns ()
  58                 {
  59 #if !MOBILE
  60                         if (Environment.GetEnvironmentVariable ("MONO_DNS") != null) {
  61                                 resolver = new SimpleResolver ();
  62                                 use_mono_dns = true;
  63                         }
  64 #endif
  65                 }
  66
  67 #if !MOBILE
  68                 internal static bool UseMonoDns {
  69                         get { return use_mono_dns; }
  70                 }
  71 #endif
  72
  73                 private delegate IPHostEntry GetHostByNameCallback (string hostName);
  74                 private delegate IPHostEntry ResolveCallback (string hostName);
  75                 private delegate IPHostEntry GetHostEntryNameCallback (string hostName);
  76                 private delegate IPHostEntry GetHostEntryIPCallback (IPAddress hostAddress);
  77                 private delegate IPAddress [] GetHostAddressesCallback (string hostName);
  78
  79 #if !MOBILE
  80                 static void OnCompleted (object sender, SimpleResolverEventArgs e)
  81                 {
  82                         DnsAsyncResult ares = (DnsAsyncResult) e.UserToken;
  83                         IPHostEntry entry = e.HostEntry;
  84                         if (entry == null || e.ResolverError != 0) {
  85                                 ares.SetCompleted (false, new Exception ("Error: " + e.ResolverError));
  86                                 return;
  87                         }
  88                         ares.SetCompleted (false, entry);
  89                 }
  90
  91                 static IAsyncResult BeginAsyncCallAddresses (string host, AsyncCallback callback, object state)
  92                 {
  93                         SimpleResolverEventArgs e = new SimpleResolverEventArgs ();
  94                         e.Completed += OnCompleted;
  95                         e.HostName = host;
  96                         DnsAsyncResult ares = new DnsAsyncResult (callback, state);
  97                         e.UserToken = ares;
  98                         if (resolver.GetHostAddressesAsync (e) == false)
  99                                 ares.SetCompleted (true, e.HostEntry); // Completed synchronously
 100                         return ares;
 101                 }
 102
 103                 static IAsyncResult BeginAsyncCall (string host, AsyncCallback callback, object state)
 104                 {
 105                         SimpleResolverEventArgs e = new SimpleResolverEventArgs ();
 106                         e.Completed += OnCompleted;
 107                         e.HostName = host;
 108                         DnsAsyncResult ares = new DnsAsyncResult (callback, state);
 109                         e.UserToken = ares;
 110                         if (resolver.GetHostEntryAsync (e) == false)
 111                                 ares.SetCompleted (true, e.HostEntry); // Completed synchronously
 112                         return ares;
 113                 }
 114
 115                 static IPHostEntry EndAsyncCall (DnsAsyncResult ares)
 116                 {
 117                         if (ares == null)
 118                                 throw new ArgumentException ("Invalid asyncResult");
 119                         if (!ares.IsCompleted)
 120                                 ares.AsyncWaitHandle.WaitOne ();
 121                         if (ares.Exception != null)
 122                                 throw ares.Exception;
 123                         IPHostEntry entry = ares.HostEntry;
 124                         if (entry == null || entry.AddressList == null || entry.AddressList.Length == 0)
 125                                 Error_11001 (entry.HostName);
 126                         return entry;
 127                 }
 128 #endif
 129
 130                 [Obsolete ("Use BeginGetHostEntry instead")]
 131                 public static IAsyncResult BeginGetHostByName (string hostName, AsyncCallback requestCallback, object stateObject)
 132                 {
 133 #if FEATURE_NO_BSD_SOCKETS
 134                         throw new PlatformNotSupportedException ("System.Net.Dns:BeginGetHostByName is not supported on this platform.");
 135 #else
 136                         if (hostName == null)
 137                                 throw new ArgumentNullException ("hostName");
 138
 139 #if !MOBILE
 140                         if (use_mono_dns)
 141                                 return BeginAsyncCall (hostName, requestCallback, stateObject);
 142 #endif
 143
 144                         GetHostByNameCallback c = new GetHostByNameCallback (GetHostByName);
 145                         return c.BeginInvoke (hostName, requestCallback, stateObject);
 146 #endif // FEATURE_NO_BSD_SOCKETS
 147                 }
 148
 149                 [Obsolete ("Use BeginGetHostEntry instead")]
 150                 public static IAsyncResult BeginResolve (string hostName, AsyncCallback requestCallback, object stateObject)
 151                 {
 152 #if FEATURE_NO_BSD_SOCKETS
 153                         throw new PlatformNotSupportedException ("System.Net.Dns:BeginResolve is not supported on this platform.");
 154 #else
 155                         if (hostName == null)
 156                                 throw new ArgumentNullException ("hostName");
 157
 158 #if !MOBILE
 159                         if (use_mono_dns)
 160                                 return BeginAsyncCall (hostName, requestCallback, stateObject);
 161 #endif
 162
 163                         ResolveCallback c = new ResolveCallback (Resolve);
 164                         return c.BeginInvoke (hostName, requestCallback, stateObject);
 165 #endif // FEATURE_NO_BSD_SOCKETS
 166                 }
 167
 168                 public static IAsyncResult BeginGetHostAddresses (string hostNameOrAddress, AsyncCallback requestCallback, object state)
 169                 {
 170                         if (hostNameOrAddress == null)
 171                                 throw new ArgumentNullException ("hostName");
 172                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 173                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 174                                         "and ::0 (IPv6) are unspecified addresses. You " +
 175                                         "cannot use them as target address.",
 176                                         "hostNameOrAddress");
 177
 178 #if !MOBILE
 179                         if (use_mono_dns)
 180                                 return BeginAsyncCallAddresses (hostNameOrAddress, requestCallback, state);
 181 #endif
 182
 183                         GetHostAddressesCallback c = new GetHostAddressesCallback (GetHostAddresses);
 184                         return c.BeginInvoke (hostNameOrAddress, requestCallback, state);
 185                 }
 186
 187                 public static IAsyncResult BeginGetHostEntry (string hostNameOrAddress, AsyncCallback requestCallback, object stateObject)
 188                 {
 189 #if FEATURE_NO_BSD_SOCKETS
 190                         throw new PlatformNotSupportedException ("System.Net.Dns:GetHostEntry is not supported on this platform.");
 191 #else
 192                         if (hostNameOrAddress == null)
 193                                 throw new ArgumentNullException ("hostName");
 194                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 195                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 196                                         "and ::0 (IPv6) are unspecified addresses. You " +
 197                                         "cannot use them as target address.",
 198                                         "hostNameOrAddress");
 199
 200 #if !MOBILE
 201                         if (use_mono_dns)
 202                                 return BeginAsyncCall (hostNameOrAddress, requestCallback, stateObject);
 203 #endif
 204
 205                         GetHostEntryNameCallback c = new GetHostEntryNameCallback (GetHostEntry);
 206                         return c.BeginInvoke (hostNameOrAddress, requestCallback, stateObject);
 207 #endif // FEATURE_NO_BSD_SOCKETS
 208                 }
 209
 210                 public static IAsyncResult BeginGetHostEntry (IPAddress address, AsyncCallback requestCallback, object stateObject)
 211                 {
 212 #if FEATURE_NO_BSD_SOCKETS
 213                         throw new PlatformNotSupportedException ("System.Net.Dns:BeginGetHostEntry is not supported on this platform.");
 214 #else
 215                         if (address == null)
 216                                 throw new ArgumentNullException ("address");
 217
 218 #if !MOBILE
 219                         if (use_mono_dns)
 220                                 return BeginAsyncCall (address.ToString (), requestCallback, stateObject);
 221 #endif
 222
 223                         GetHostEntryIPCallback c = new GetHostEntryIPCallback (GetHostEntry);
 224                         return c.BeginInvoke (address, requestCallback, stateObject);
 225 #endif // FEATURE_NO_BSD_SOCKETS
 226                 }
 227
 228                 [Obsolete ("Use EndGetHostEntry instead")]
 229                 public static IPHostEntry EndGetHostByName (IAsyncResult asyncResult)
 230                 {
 231                         if (asyncResult == null)
 232                                 throw new ArgumentNullException ("asyncResult");
 233
 234 #if !MOBILE
 235                         if (use_mono_dns)
 236                                 return EndAsyncCall (asyncResult as DnsAsyncResult);
 237 #endif
 238
 239                         AsyncResult async = (AsyncResult) asyncResult;
 240                         GetHostByNameCallback cb = (GetHostByNameCallback) async.AsyncDelegate;
 241                         return cb.EndInvoke(asyncResult);
 242                 }
 243
 244                 [Obsolete ("Use EndGetHostEntry instead")]
 245                 public static IPHostEntry EndResolve (IAsyncResult asyncResult)
 246                 {
 247                         if (asyncResult == null)
 248                                 throw new ArgumentNullException ("asyncResult");
 249
 250 #if !MOBILE
 251                         if (use_mono_dns)
 252                                 return EndAsyncCall (asyncResult as DnsAsyncResult);
 253 #endif
 254
 255                         AsyncResult async = (AsyncResult) asyncResult;
 256                         ResolveCallback cb = (ResolveCallback) async.AsyncDelegate;
 257                         return cb.EndInvoke(asyncResult);
 258                 }
 259
 260                 public static IPAddress [] EndGetHostAddresses (IAsyncResult asyncResult)
 261                 {
 262                         if (asyncResult == null)
 263                                 throw new ArgumentNullException ("asyncResult");
 264
 265 #if !MOBILE
 266                         if (use_mono_dns) {
 267                                 IPHostEntry entry = EndAsyncCall (asyncResult as DnsAsyncResult);
 268                                 if (entry == null)
 269                                         return null;
 270                                 return entry.AddressList;
 271                         }
 272 #endif
 273
 274                         AsyncResult async = (AsyncResult) asyncResult;
 275                         GetHostAddressesCallback cb = (GetHostAddressesCallback) async.AsyncDelegate;
 276                         return cb.EndInvoke(asyncResult);
 277                 }
 278
 279                 public static IPHostEntry EndGetHostEntry (IAsyncResult asyncResult)
 280                 {
 281                         if (asyncResult == null)
 282                                 throw new ArgumentNullException ("asyncResult");
 283
 284 #if !MOBILE
 285                         if (use_mono_dns)
 286                                 return EndAsyncCall (asyncResult as DnsAsyncResult);
 287 #endif
 288
 289                         AsyncResult async = (AsyncResult) asyncResult;
 290                         if (async.AsyncDelegate is GetHostEntryIPCallback)
 291                                 return ((GetHostEntryIPCallback) async.AsyncDelegate).EndInvoke (asyncResult);
 292                         GetHostEntryNameCallback cb = (GetHostEntryNameCallback) async.AsyncDelegate;
 293                         return cb.EndInvoke(asyncResult);
 294                 }
 295
 296
 297                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 298                 private extern static bool GetHostByName_internal(string host, out string h_name, out string[] h_aliases, out string[] h_addr_list);
 299
 300                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 301                 private extern static bool GetHostByAddr_internal(string addr, out string h_name, out string[] h_aliases, out string[] h_addr_list);
 302
 303                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 304                 private extern static bool GetHostName_internal(out string h_name);
 305
 306                 static void Error_11001 (string hostName)
 307                 {
 308                         throw new SocketException(11001, string.Format ("Could not resolve host '{0}'", hostName));
 309
 310                 }
 311
 312                 private static IPHostEntry hostent_to_IPHostEntry(string originalHostName, string h_name, string[] h_aliases, string[] h_addrlist)
 313                 {
 314                         IPHostEntry he = new IPHostEntry();
 315                         ArrayList addrlist = new ArrayList();
 316
 317                         he.HostName = h_name;
 318                         he.Aliases = h_aliases;
 319                         for(int i=0; i<h_addrlist.Length; i++) {
 320                                 try {
 321                                         IPAddress newAddress = IPAddress.Parse(h_addrlist[i]);
 322
 323                                         if( (Socket.SupportsIPv6 && newAddress.AddressFamily == AddressFamily.InterNetworkV6) ||
 324                                             (Socket.SupportsIPv4 && newAddress.AddressFamily == AddressFamily.InterNetwork) )
 325                                                 addrlist.Add(newAddress);
 326                                 } catch (ArgumentNullException) {
 327                                         /* Ignore this, as the
 328                                          * internal call might have
 329                                          * left some blank entries at
 330                                          * the end of the array
 331                                          */
 332                                 }
 333                         }
 334
 335                         if(addrlist.Count == 0)
 336                                 Error_11001 (originalHostName);
 337
 338                         he.AddressList = addrlist.ToArray(typeof(IPAddress)) as IPAddress[];
 339                         return he;
 340                 }
 341
 342                 [Obsolete ("Use GetHostEntry instead")]
 343                 public static IPHostEntry GetHostByAddress(IPAddress address)
 344                 {
 345                         if (address == null)
 346                                 throw new ArgumentNullException ("address");
 347
 348                         return GetHostByAddressFromString (address.ToString (), false);
 349                 }
 350
 351                 [Obsolete ("Use GetHostEntry instead")]
 352                 public static IPHostEntry GetHostByAddress(string address)
 353                 {
 354                         if (address == null)
 355                                 throw new ArgumentNullException ("address");
 356
 357                         return GetHostByAddressFromString (address, true);
 358                 }
 359
 360                 static IPHostEntry GetHostByAddressFromString (string address, bool parse)
 361                 {
 362                         // Undocumented MS behavior: when called with IF_ANY,
 363                         // this should return the local host
 364                         if (address.Equals ("0.0.0.0")) {
 365                                 address = "127.0.0.1";
 366                                 parse = false;
 367                         }
 368
 369                         // Must check the IP format, might send an exception if invalid string.
 370                         if (parse)
 371                                 IPAddress.Parse (address);
 372
 373                         string h_name;
 374                         string[] h_aliases, h_addrlist;
 375                         bool ret = GetHostByAddr_internal(address, out h_name, out h_aliases, out h_addrlist);
 376                         if (!ret)
 377                                 Error_11001 (address);
 378                         return (hostent_to_IPHostEntry (address, h_name, h_aliases, h_addrlist));
 379
 380                 }
 381
 382                 public static IPHostEntry GetHostEntry (string hostNameOrAddress)
 383                 {
 384                         if (hostNameOrAddress == null)
 385                                 throw new ArgumentNullException ("hostNameOrAddress");
 386                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 387                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 388                                         "and ::0 (IPv6) are unspecified addresses. You " +
 389                                         "cannot use them as target address.",
 390                                         "hostNameOrAddress");
 391
 392                         IPAddress addr;
 393                         if (hostNameOrAddress.Length > 0 && IPAddress.TryParse (hostNameOrAddress, out addr))
 394                                 return GetHostEntry (addr);
 395
 396                         return GetHostByName (hostNameOrAddress);
 397                 }
 398
 399                 public static IPHostEntry GetHostEntry (IPAddress address)
 400                 {
 401                         if (address == null)
 402                                 throw new ArgumentNullException ("address");
 403
 404                         return GetHostByAddressFromString (address.ToString (), false);
 405                 }
 406
 407                 public static IPAddress [] GetHostAddresses (string hostNameOrAddress)
 408                 {
 409                         if (hostNameOrAddress == null)
 410                                 throw new ArgumentNullException ("hostNameOrAddress");
 411
 412                         if (hostNameOrAddress == "0.0.0.0" || hostNameOrAddress == "::0")
 413                                 throw new ArgumentException ("Addresses 0.0.0.0 (IPv4) " +
 414                                         "and ::0 (IPv6) are unspecified addresses. You " +
 415                                         "cannot use them as target address.",
 416                                         "hostNameOrAddress");
 417
 418                         IPAddress addr;
 419                         if (hostNameOrAddress.Length > 0 && IPAddress.TryParse (hostNameOrAddress, out addr))
 420                                 return new IPAddress[1] { addr };
 421
 422                         return GetHostEntry (hostNameOrAddress).AddressList;
 423                 }
 424
 425                 [Obsolete ("Use GetHostEntry instead")]
 426                 public static IPHostEntry GetHostByName (string hostName)
 427                 {
 428 #if FEATURE_NO_BSD_SOCKETS
 429                         if (!string.IsNullOrEmpty (hostName))
 430                                 throw new PlatformNotSupportedException ("System.Net.Dns:GetHostByName is not supported on this platform.");
 431 #endif // FEATURE_NO_BSD_SOCKETS
 432                         if (hostName == null)
 433                                 throw new ArgumentNullException ("hostName");
 434                         string h_name;
 435                         string[] h_aliases, h_addrlist;
 436
 437                         bool ret = GetHostByName_internal(hostName, out h_name, out h_aliases, out h_addrlist);
 438                         if (ret == false)
 439                                 Error_11001 (hostName);
 440
 441                         return(hostent_to_IPHostEntry(hostName, h_name, h_aliases, h_addrlist));
 442                 }
 443
 444                 public static string GetHostName ()
 445                 {
 446                         string hostName;
 447
 448                         bool ret = GetHostName_internal(out hostName);
 449
 450                         if (ret == false)
 451                                 Error_11001 (hostName);
 452
 453                         return hostName;
 454                 }
 455
 456                 [Obsolete ("Use GetHostEntry instead")]
 457                 public static IPHostEntry Resolve(string hostName)
 458                 {
 459 #if FEATURE_NO_BSD_SOCKETS
 460                         throw new PlatformNotSupportedException ("System.Net.Dns:Resolve is not supported on this platform.");
 461 #else
 462                         if (hostName == null)
 463                                 throw new ArgumentNullException ("hostName");
 464
 465                         IPHostEntry ret = null;
 466
 467                         try {
 468                                 ret =  GetHostByAddress(hostName);
 469                         }
 470                         catch{}
 471
 472                         if(ret == null)
 473                                 ret =  GetHostByName(hostName);
 474
 475                         return ret;
 476 #endif // FEATURE_NO_BSD_SOCKETS
 477                 }
 478
 479                 public static Task<IPAddress[]> GetHostAddressesAsync (string hostNameOrAddress)
 480                 {
 481                         return Task<IPAddress[]>.Factory.FromAsync (BeginGetHostAddresses, EndGetHostAddresses, hostNameOrAddress, null);
 482                 }
 483
 484                 public static Task<IPHostEntry> GetHostEntryAsync (IPAddress address)
 485                 {
 486                         return Task<IPHostEntry>.Factory.FromAsync (BeginGetHostEntry, EndGetHostEntry, address, null);
 487                 }
 488
 489                 public static Task<IPHostEntry> GetHostEntryAsync (string hostNameOrAddress)
 490                 {
 491                         return Task<IPHostEntry>.Factory.FromAsync (BeginGetHostEntry, EndGetHostEntry, hostNameOrAddress, null);
 492                 }
 493         }
 494 }
 495