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