mcs/class/System/Test/System.Net/DnsTest.cs

   1 // DnsTest.cs - NUnit Test Cases for the System.Net.Dns class\r
   2 //\r
   3 // Authors: \r
   4 //   Mads Pultz (mpultz@diku.dk)\r
   5 //   Martin Willemoes Hansen (mwh@sysrq.dk)\r
   6 //\r
   7 // (C) 2001 Mads Pultz\r
   8 // (C) 2003 Martin Willemoes Hansen\r
   9 // \r
  10 \r
  11 using System;\r
  12 using System.Linq;\r
  13 using System.Net;\r
  14 using System.Net.Sockets;\r
  15 using System.Threading;\r
  16 \r
  17 using NUnit.Framework;\r
  18 \r
  19 namespace MonoTests.System.Net\r
  20 {\r
  21         [TestFixture]\r
  22         [Category ("RequiresBSDSockets")]\r
  23         public class DnsTest\r
  24         {\r
  25                 private String site1Name = "google-public-dns-a.google.com",\r
  26                         site1Dot = "8.8.8.8",\r
  27                         site2Name = "google-public-dns-b.google.com",\r
  28                         site2Dot = "8.8.4.4",\r
  29                         noneExistingSite = "unlikely.xamarin.com";\r
  30                 private uint site1IP = 134744072, site2IP = 134743044; // Big-Endian\r
  31 \r
  32                 [Test]\r
  33                 public void AsyncGetHostByName ()\r
  34                 {\r
  35                         IAsyncResult async = Dns.BeginGetHostByName (site1Name, null, null);\r
  36                         IPHostEntry entry = Dns.EndGetHostByName (async);\r
  37                         SubTestValidIPHostEntry (entry);\r
  38                         Assert.IsTrue (entry.HostName == "google-public-dns-a.google.com");\r
  39                 }\r
  40 \r
  41                 [Test]\r
  42                 public void AsyncGetHostByNameCallback ()\r
  43                 {\r
  44                         var evt = new ManualResetEvent (false);\r
  45                         Exception ex = null;\r
  46                         Dns.BeginGetHostByName (site1Name, new AsyncCallback ((IAsyncResult ar) =>\r
  47                         {\r
  48                                 try {\r
  49                                         IPHostEntry h;\r
  50                                         h = Dns.EndGetHostByName (ar);\r
  51                                         SubTestValidIPHostEntry (h);\r
  52                                 } catch (Exception e) {\r
  53                                         ex = e;\r
  54                                 } finally {\r
  55                                         evt.Set ();\r
  56                                 }\r
  57                         }), null);\r
  58 \r
  59                         Assert.IsTrue (evt.WaitOne (TimeSpan.FromSeconds (60)), "Wait");\r
  60                         Assert.IsNull (ex, "Exception");\r
  61                 }\r
  62 \r
  63                 [Test]\r
  64                 public void AsyncResolve ()\r
  65                 {\r
  66                         IAsyncResult async = Dns.BeginResolve (site1Dot, null, null);\r
  67                         IPHostEntry entry = Dns.EndResolve (async);\r
  68                         SubTestValidIPHostEntry (entry);\r
  69                         var ip = GetIPv4Address (entry);\r
  70                         Assert.AreEqual (site1Dot, ip.ToString ());\r
  71                 }\r
  72 \r
  73                 [Test]\r
  74                 public void AsyncResolveCallback ()\r
  75                 {\r
  76                         var evt = new ManualResetEvent (false);\r
  77                         Exception ex = null;\r
  78                         Dns.BeginResolve (site1Name, new AsyncCallback ((IAsyncResult ar) =>\r
  79                         {\r
  80                                 try {\r
  81                                         IPHostEntry h = Dns.EndResolve (ar);\r
  82                                         SubTestValidIPHostEntry (h);\r
  83                                 } catch (Exception e) {\r
  84                                         ex = e;\r
  85                                 } finally {\r
  86                                         evt.Set ();\r
  87                                 }\r
  88                         }), null);\r
  89 \r
  90                         Assert.IsTrue (evt.WaitOne (TimeSpan.FromSeconds (60)), "Wait");\r
  91                         Assert.IsNull (ex, "Exception");\r
  92                 }\r
  93 \r
  94                 [Test]\r
  95                 public void BeginGetHostAddresses_HostNameOrAddress_Null ()\r
  96                 {\r
  97                         try {\r
  98                                 Dns.BeginGetHostAddresses (\r
  99                                         (string) null,\r
 100                                         new AsyncCallback (ShouldntBeCalled),\r
 101                                         null);\r
 102                                 Assert.Fail ("#1");\r
 103                         } catch (ArgumentNullException ex) {\r
 104                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 105                                 Assert.IsNull (ex.InnerException, "#3");\r
 106                                 Assert.IsNotNull (ex.Message, "#4");\r
 107                                 Assert.AreEqual ("hostName", ex.ParamName, "#5");\r
 108                         }\r
 109                 }\r
 110 \r
 111                 [Test]\r
 112                 public void BeginGetHostAddresses_HostNameOrAddress_UnspecifiedAddress ()\r
 113                 {\r
 114                         // IPv4\r
 115                         try {\r
 116                                 Dns.BeginGetHostAddresses (\r
 117                                         "0.0.0.0",\r
 118                                         new AsyncCallback (ShouldntBeCalled),\r
 119                                         null);\r
 120                                 Assert.Fail ("#A1");\r
 121                         } catch (ArgumentException ex) {\r
 122                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 123                                 // unspecified addresses that cannot be used as\r
 124                                 // a target address\r
 125                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#A2");\r
 126                                 Assert.IsNull (ex.InnerException, "#A3");\r
 127                                 Assert.IsNotNull (ex.Message, "#A4");\r
 128                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#A5");\r
 129                         }\r
 130 \r
 131                         // IPv6\r
 132                         try {\r
 133                                 Dns.BeginGetHostAddresses (\r
 134                                         "::0",\r
 135                                         new AsyncCallback (ShouldntBeCalled),\r
 136                                         null);\r
 137                                 Assert.Fail ("#B1");\r
 138                         } catch (ArgumentException ex) {\r
 139                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 140                                 // unspecified addresses that cannot be used as\r
 141                                 // a target address\r
 142                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#B2");\r
 143                                 Assert.IsNull (ex.InnerException, "#B3");\r
 144                                 Assert.IsNotNull (ex.Message, "#B4");\r
 145                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#B5");\r
 146                         }\r
 147                 }\r
 148 \r
 149                 void ShouldntBeCalled (IAsyncResult ar)\r
 150                 {\r
 151                         Assert.Fail ("Should not be called");\r
 152                 }\r
 153 \r
 154                 [Test]\r
 155                 public void GetHostAddresses_HostNameOrAddress_Null ()\r
 156                 {\r
 157                         try {\r
 158                                 Dns.GetHostAddresses ((string) null);\r
 159                                 Assert.Fail ("#1");\r
 160                         } catch (ArgumentNullException ex) {\r
 161                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 162                                 Assert.IsNull (ex.InnerException, "#3");\r
 163                                 Assert.IsNotNull (ex.Message, "#4");\r
 164                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#5");\r
 165                         }\r
 166                 }\r
 167 \r
 168                 [Test]\r
 169                 public void GetHostAddresses_HostNameOrAddress_UnspecifiedAddress ()\r
 170                 {\r
 171                         // IPv4\r
 172                         try {\r
 173                                 Dns.GetHostAddresses ("0.0.0.0");\r
 174                                 Assert.Fail ("#A1");\r
 175                         } catch (ArgumentException ex) {\r
 176                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 177                                 // unspecified addresses that cannot be used as\r
 178                                 // a target address\r
 179                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#A2");\r
 180                                 Assert.IsNull (ex.InnerException, "#A3");\r
 181                                 Assert.IsNotNull (ex.Message, "#A4");\r
 182                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#A5");\r
 183                         }\r
 184 \r
 185                         // IPv6\r
 186                         try {\r
 187                                 Dns.GetHostAddresses ("::0");\r
 188                                 Assert.Fail ("#B1");\r
 189                         } catch (ArgumentException ex) {\r
 190                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 191                                 // unspecified addresses that cannot be used as\r
 192                                 // a target address\r
 193                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#B2");\r
 194                                 Assert.IsNull (ex.InnerException, "#B3");\r
 195                                 Assert.IsNotNull (ex.Message, "#B4");\r
 196                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#B5");\r
 197                         }\r
 198                 }\r
 199 \r
 200                 [Test]\r
 201                 public void GetHostName ()\r
 202                 {\r
 203                         string hostName = Dns.GetHostName ();\r
 204                         Assert.IsNotNull (hostName);\r
 205                 }\r
 206 \r
 207                 [Test]\r
 208                 public void GetHostByName ()\r
 209                 {\r
 210                         SubTestGetHostByName (site1Name, site1Dot);\r
 211                         SubTestGetHostByName (site2Name, site2Dot);\r
 212                         try {\r
 213                                 var entry = Dns.GetHostByName (noneExistingSite);\r
 214                                 /*\r
 215                                  * Work around broken t-online.de DNS Server.\r
 216                                  * \r
 217                                  * T-Online's DNS Server for DSL Customers resolves\r
 218                                  * non-exisitng domain names to\r
 219                                  * http://navigationshilfe1.t-online.de/dnserror?url=....\r
 220                                  * instead of reporting an error.\r
 221                                  */\r
 222                                 var navigationshilfe1 = IPAddress.Parse ("80.156.86.78");\r
 223                                 var navigationshilfe2 = IPAddress.Parse ("62.157.140.133");\r
 224                                 foreach (var addr in entry.AddressList) {\r
 225                                         if (addr.Equals (navigationshilfe1) || addr.Equals (navigationshilfe2))\r
 226                                                 return;\r
 227                                 }\r
 228                                 Assert.Fail ("Should raise a SocketException (assuming that '" + noneExistingSite + "' does not exist)");\r
 229                         } catch (SocketException) {\r
 230                         }\r
 231                 }\r
 232 \r
 233                 static IPAddress GetIPv4Address (IPHostEntry h)\r
 234                 {\r
 235                         var al = h.AddressList.FirstOrDefault (x => x.AddressFamily == AddressFamily.InterNetwork);\r
 236                         if (al == null)\r
 237                                 Assert.Ignore ("Could not resolve an IPv4 address as required by this test case, e.g. running on an IPv6 only network");\r
 238                         return al;\r
 239                 }\r
 240 \r
 241                 void SubTestGetHostByName (string siteName, string siteDot)\r
 242                 {\r
 243                         IPHostEntry h = Dns.GetHostByName (siteName);\r
 244                         SubTestValidIPHostEntry (h);\r
 245                         Assert.AreEqual (siteName, h.HostName, "siteName");\r
 246                         var ip = GetIPv4Address (h);\r
 247                         Assert.AreEqual (siteDot, ip.ToString (), "siteDot");\r
 248                 }\r
 249 \r
 250                 [Test]\r
 251                 public void GetHostByName_HostName_Null ()\r
 252                 {\r
 253                         try {\r
 254                                 Dns.GetHostByName ((string) null);\r
 255                                 Assert.Fail ("#1");\r
 256                         } catch (ArgumentNullException ex) {\r
 257                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 258                                 Assert.IsNull (ex.InnerException, "#3");\r
 259                                 Assert.IsNotNull (ex.Message, "#4");\r
 260                                 Assert.AreEqual ("hostName", ex.ParamName, "#5");\r
 261                         }\r
 262                 }\r
 263 \r
 264                 [Test]\r
 265                 public void GetHostByAddressString_Address_Null ()\r
 266                 {\r
 267                         try {\r
 268                                 Dns.GetHostByAddress ((string) null);\r
 269                                 Assert.Fail ("#1");\r
 270                         } catch (ArgumentNullException ex) {\r
 271                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 272                                 Assert.IsNull (ex.InnerException, "#3");\r
 273                                 Assert.IsNotNull (ex.Message, "#4");\r
 274                                 Assert.AreEqual ("address", ex.ParamName, "#5");\r
 275                         }\r
 276                 }\r
 277 \r
 278                 [Test]\r
 279                 [ExpectedException (typeof (SocketException))]\r
 280                 public void GetHostByAddressString2 ()\r
 281                 {\r
 282                         Dns.GetHostByAddress ("123.255.23");\r
 283                 }\r
 284 \r
 285                 [Test]\r
 286                 [ExpectedException (typeof (FormatException))]\r
 287                 public void GetHostByAddressString3 ()\r
 288                 {\r
 289                         Dns.GetHostByAddress ("123.256.34.10");\r
 290                 }\r
 291 \r
 292                 [Test, ExpectedException (typeof (FormatException))]\r
 293                 public void GetHostByAddressString4 ()\r
 294                 {\r
 295                         Dns.GetHostByAddress ("not an IP address");\r
 296                 }\r
 297 \r
 298                 [Test]\r
 299                 public void GetHostByAddressString5 ()\r
 300                 {\r
 301                         Dns.GetHostByAddress (site1Dot);\r
 302                 }\r
 303 \r
 304                 [Test]\r
 305                 public void GetHostByAddressIPAddress_Address_Null ()\r
 306                 {\r
 307                         try {\r
 308                                 Dns.GetHostByAddress ((IPAddress) null);\r
 309                                 Assert.Fail ("#1");\r
 310                         } catch (ArgumentNullException ex) {\r
 311                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 312                                 Assert.IsNull (ex.InnerException, "#3");\r
 313                                 Assert.IsNotNull (ex.Message, "#4");\r
 314                                 Assert.AreEqual ("address", ex.ParamName, "#5");\r
 315                         }\r
 316                 }\r
 317 \r
 318                 [Test]\r
 319                 public void GetHostByAddressIPAddress2 ()\r
 320                 {\r
 321                         IPAddress addr = new IPAddress (IPAddress.NetworkToHostOrder ((int) site1IP));\r
 322                         IPHostEntry h = Dns.GetHostByAddress (addr);\r
 323                         SubTestValidIPHostEntry (h);\r
 324                         var ip = GetIPv4Address (h);\r
 325                         Assert.AreEqual (addr.ToString (), ip.ToString ());\r
 326                 }\r
 327 \r
 328                 [Test]\r
 329                 public void GetHostByAddressIPAddress3 ()\r
 330                 {\r
 331                         IPAddress addr = new IPAddress (IPAddress.NetworkToHostOrder ((int) site2IP));\r
 332                         IPHostEntry h = Dns.GetHostByAddress (addr);\r
 333                         SubTestValidIPHostEntry (h);\r
 334                         var ip = GetIPv4Address (h);\r
 335                         Assert.AreEqual (addr.ToString (), ip.ToString ());\r
 336                 }\r
 337 \r
 338                 [Test]\r
 339                 public void BeginResolve_HostName_Null ()\r
 340                 {\r
 341                         try {\r
 342                                 Dns.BeginResolve ((string) null,\r
 343                                         new AsyncCallback (ShouldntBeCalled),\r
 344                                         null);\r
 345                                 Assert.Fail ("#1");\r
 346                         } catch (ArgumentNullException ex) {\r
 347                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 348                                 Assert.IsNull (ex.InnerException, "#3");\r
 349                                 Assert.IsNotNull (ex.Message, "#4");\r
 350                                 Assert.AreEqual ("hostName", ex.ParamName, "#5");\r
 351                         }\r
 352                 }\r
 353 \r
 354                 [Test]\r
 355                 public void Resolve ()\r
 356                 {\r
 357                         SubTestResolve (site1Name);\r
 358                         SubTestResolve (site2Name);\r
 359                         SubTestResolve (site1Dot);\r
 360                         SubTestResolve (site2Dot);\r
 361                 }\r
 362 \r
 363                 void SubTestResolve (string addr)\r
 364                 {\r
 365                         IPHostEntry h = Dns.Resolve (addr);\r
 366                         SubTestValidIPHostEntry (h);\r
 367                 }\r
 368 \r
 369                 [Test]\r
 370                 public void Resolve_HostName_Null ()\r
 371                 {\r
 372                         try {\r
 373                                 Dns.Resolve ((string) null);\r
 374                                 Assert.Fail ("#1");\r
 375                         } catch (ArgumentNullException ex) {\r
 376                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 377                                 Assert.IsNull (ex.InnerException, "#3");\r
 378                                 Assert.IsNotNull (ex.Message, "#4");\r
 379                                 Assert.AreEqual ("hostName", ex.ParamName, "#5");\r
 380                         }\r
 381                 }\r
 382 \r
 383                 [Test] // BeginGetHostEntry (IPAddress, AsyncCallback, Object)\r
 384                 public void BeginGetHostEntry1_Address_Null ()\r
 385                 {\r
 386                         try {\r
 387                                 Dns.BeginGetHostEntry (\r
 388                                         (IPAddress) null,\r
 389                                         new AsyncCallback (ShouldntBeCalled),\r
 390                                         null);\r
 391                                 Assert.Fail ("#1");\r
 392                         } catch (ArgumentNullException ex) {\r
 393                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 394                                 Assert.IsNull (ex.InnerException, "#3");\r
 395                                 Assert.IsNotNull (ex.Message, "#4");\r
 396                                 Assert.AreEqual ("address", ex.ParamName, "#5");\r
 397                         }\r
 398                 }\r
 399 \r
 400                 [Test] // BeginGetHostEntry (String, AsyncCallback, Object)\r
 401                 public void BeginGetHostEntry2_HostNameOrAddress_Null ()\r
 402                 {\r
 403                         try {\r
 404                                 Dns.BeginGetHostEntry (\r
 405                                         (string) null,\r
 406                                         new AsyncCallback (ShouldntBeCalled),\r
 407                                         null);\r
 408                                 Assert.Fail ("#1");\r
 409                         } catch (ArgumentNullException ex) {\r
 410                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 411                                 Assert.IsNull (ex.InnerException, "#3");\r
 412                                 Assert.IsNotNull (ex.Message, "#4");\r
 413                                 Assert.AreEqual ("hostName", ex.ParamName, "#5");\r
 414                         }\r
 415                 }\r
 416 \r
 417                 [Test] // BeginGetHostEntry (String, AsyncCallback, Object)\r
 418                 public void BeginGetHostEntry2_HostNameOrAddress_UnspecifiedAddress ()\r
 419                 {\r
 420                         // IPv4\r
 421                         try {\r
 422                                 Dns.BeginGetHostEntry (\r
 423                                         "0.0.0.0",\r
 424                                         new AsyncCallback (GetHostEntryCallback),\r
 425                                         null);\r
 426                                 Assert.Fail ("#1");\r
 427                         } catch (ArgumentException ex) {\r
 428                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 429                                 // unspecified addresses that cannot be used as\r
 430                                 // a target address\r
 431                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#2");\r
 432                                 Assert.IsNull (ex.InnerException, "#3");\r
 433                                 Assert.IsNotNull (ex.Message, "#4");\r
 434                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#5");\r
 435                         }\r
 436 \r
 437                         // IPv6\r
 438                         try {\r
 439                                 Dns.BeginGetHostEntry (\r
 440                                         "::0",\r
 441                                         new AsyncCallback (GetHostEntryCallback),\r
 442                                         null);\r
 443                                 Assert.Fail ("#1");\r
 444                         } catch (ArgumentException ex) {\r
 445                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 446                                 // unspecified addresses that cannot be used as\r
 447                                 // a target address\r
 448                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#2");\r
 449                                 Assert.IsNull (ex.InnerException, "#3");\r
 450                                 Assert.IsNotNull (ex.Message, "#4");\r
 451                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#5");\r
 452                         }\r
 453                 }\r
 454 \r
 455                 void GetHostEntryCallback (IAsyncResult ar)\r
 456                 {\r
 457                         IPHostEntry hostEntry = Dns.EndGetHostEntry (ar);\r
 458                         Assert.IsNotNull (hostEntry);\r
 459                 }\r
 460 \r
 461                 [Test] // GetHostEntry (IPAddress)\r
 462                 public void GetHostEntry1_Address_Null ()\r
 463                 {\r
 464                         try {\r
 465                                 Dns.GetHostEntry ((IPAddress) null);\r
 466                                 Assert.Fail ("#1");\r
 467                         } catch (ArgumentNullException ex) {\r
 468                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 469                                 Assert.IsNull (ex.InnerException, "#3");\r
 470                                 Assert.IsNotNull (ex.Message, "#4");\r
 471                                 Assert.AreEqual ("address", ex.ParamName, "#5");\r
 472                         }\r
 473                 }\r
 474 \r
 475                 [Test] // GetHostEntry (String)\r
 476                 public void GetHostEntry2 ()\r
 477                 {\r
 478                         Dns.GetHostEntry (site1Name); // hostname\r
 479                         Dns.GetHostEntry (site1Dot); // IP address\r
 480                 }\r
 481 \r
 482                 [Test] // GetHostEntry (String)\r
 483                 public void GetHostEntry2_HostNameOrAddress_Null ()\r
 484                 {\r
 485                         try {\r
 486                                 Dns.GetHostEntry ((string) null);\r
 487                                 Assert.Fail ("#1");\r
 488                         } catch (ArgumentNullException ex) {\r
 489                                 Assert.AreEqual (typeof (ArgumentNullException), ex.GetType (), "#2");\r
 490                                 Assert.IsNull (ex.InnerException, "#3");\r
 491                                 Assert.IsNotNull (ex.Message, "#4");\r
 492                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#5");\r
 493                         }\r
 494                 }\r
 495 \r
 496                 [Test] // GetHostEntry (String)\r
 497                 public void GetHostEntry2_HostNameOrAddress_UnspecifiedAddress ()\r
 498                 {\r
 499                         // IPv4\r
 500                         try {\r
 501                                 Dns.GetHostEntry ("0.0.0.0");\r
 502                                 Assert.Fail ("#A1");\r
 503                         } catch (ArgumentException ex) {\r
 504                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 505                                 // unspecified addresses that cannot be used as\r
 506                                 // a target address\r
 507                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#A2");\r
 508                                 Assert.IsNull (ex.InnerException, "#A3");\r
 509                                 Assert.IsNotNull (ex.Message, "#A4");\r
 510                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#A5");\r
 511                         }\r
 512 \r
 513                         // IPv6\r
 514                         try {\r
 515                                 Dns.GetHostEntry ("::0");\r
 516                                 Assert.Fail ("#B1");\r
 517                         } catch (ArgumentException ex) {\r
 518                                 // IPv4 address 0.0.0.0 and IPv6 address ::0 are\r
 519                                 // unspecified addresses that cannot be used as\r
 520                                 // a target address\r
 521                                 Assert.AreEqual (typeof (ArgumentException), ex.GetType (), "#B2");\r
 522                                 Assert.IsNull (ex.InnerException, "#B3");\r
 523                                 Assert.IsNotNull (ex.Message, "#B4");\r
 524                                 Assert.AreEqual ("hostNameOrAddress", ex.ParamName, "#B5");\r
 525                         }\r
 526                 }\r
 527 \r
 528                 void SubTestValidIPHostEntry (IPHostEntry h)\r
 529                 {\r
 530                         Assert.IsNotNull (h.HostName, "HostName not null");\r
 531                         Assert.IsNotNull (h.AddressList, "AddressList not null");\r
 532                         Assert.IsTrue (h.AddressList.Length > 0, "AddressList.Length");\r
 533                 }\r
 534 \r
 535                 [Test]\r
 536                 public void GetHostEntry_StringEmpty ()\r
 537                 {\r
 538                         Dns.GetHostEntry (string.Empty);\r
 539                 }\r
 540 \r
 541                 /* This isn't used anymore, but could be useful for debugging\r
 542                 static void printIPHostEntry(IPHostEntry h)\r
 543                 {\r
 544                         Console.WriteLine("----------------------------------------------------");\r
 545                         Console.WriteLine("Host name:");\r
 546                         Console.WriteLine(h.HostName);\r
 547                         Console.WriteLine("IP addresses:");\r
 548                         IPAddress[] list = h.AddressList;\r
 549                         for(int i = 0; i < list.Length; ++i)\r
 550                                 Console.WriteLine(list[i]);\r
 551                         Console.WriteLine("Aliases:");\r
 552                         string[] aliases = h.Aliases;\r
 553                         for(int i = 0; i < aliases.Length; ++i)\r
 554                                 Console.WriteLine(aliases[i]);\r
 555                         Console.WriteLine("----------------------------------------------------");\r
 556                 }\r
 557                 */\r
 558         }\r
 559 }\r