mcs/class/System/System.Net.NetworkInformation/Ping.cs

   1 //
   2 // System.Net.NetworkInformation.Ping
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@novell.com)
   6 //      Atsushi Enomoto (atsushi@ximian.com)
   7 //
   8 // Copyright (c) 2006-2007 Novell, Inc. (http://www.novell.com)
   9 // Copyright 2015 Xamarin Inc.
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System;
  32 using System.IO;
  33 using System.Text;
  34 using System.Diagnostics;
  35 using System.Globalization;
  36 using System.ComponentModel;
  37 using System.Net.Sockets;
  38 using System.Security.Principal;
  39 using System.Security.Cryptography;
  40 using System.Runtime.InteropServices;
  41 using System.Threading;
  42 using System.Threading.Tasks;
  43
  44 namespace System.Net.NetworkInformation {
  45         [MonoTODO ("IPv6 support is missing")]
  46         public class Ping : Component, IDisposable
  47         {
  48 #if !MONOTOUCH
  49                 [StructLayout(LayoutKind.Sequential)]
  50                 struct cap_user_header_t
  51                 {
  52                         public UInt32 version;
  53                         public Int32 pid;
  54                 };
  55
  56                 [StructLayout(LayoutKind.Sequential)]
  57                 struct cap_user_data_t
  58                 {
  59                         public UInt32 effective;
  60                         public UInt32 permitted;
  61                         public UInt32 inheritable;
  62                 }
  63
  64                 const int DefaultCount = 1;
  65                 static readonly string [] PingBinPaths = new string [] {
  66                         "/bin/ping",
  67                         "/sbin/ping",
  68                         "/usr/sbin/ping",
  69 #if MONODROID
  70                         "/system/bin/ping"
  71 #endif
  72                 };
  73                 static readonly string PingBinPath;
  74                 static bool canSendPrivileged;
  75 #endif
  76                 const int default_timeout = 4000; // 4 sec.
  77                 ushort identifier;
  78
  79                 // This value is correct as of Linux kernel version 2.6.25.9
  80                 // See /usr/include/linux/capability.h
  81                 const UInt32 linux_cap_version = 0x20071026;
  82
  83                 static readonly byte [] default_buffer = new byte [0];
  84
  85
  86                 BackgroundWorker worker;
  87                 object user_async_state;
  88                 CancellationTokenSource cts;
  89
  90                 public event PingCompletedEventHandler PingCompleted;
  91
  92 #if !MONOTOUCH && !ORBIS
  93                 static Ping ()
  94                 {
  95                         if (Environment.OSVersion.Platform == PlatformID.Unix) {
  96                                 CheckLinuxCapabilities ();
  97                                 if (!canSendPrivileged && WindowsIdentity.GetCurrent ().Name == "root")
  98                                         canSendPrivileged = true;
  99
 100                                 // Since different Unix systems can have different path to bin, we try some
 101                                 // of the known ones.
 102                                 foreach (string ping_path in PingBinPaths)
 103                                         if (File.Exists (ping_path)) {
 104                                                 PingBinPath = ping_path;
 105                                                 break;
 106                                         }
 107                         }
 108                         else
 109                                 canSendPrivileged = true;
 110
 111                         if (PingBinPath == null)
 112                                 PingBinPath = "/bin/ping"; // default, fallback value
 113                 }
 114 #endif
 115
 116                 public Ping ()
 117                 {
 118                         // Generate a new random 16 bit identifier for every ping
 119                         RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider ();
 120                         byte [] randomIdentifier = new byte [2];
 121                         rng.GetBytes (randomIdentifier);
 122                         identifier = (ushort)(randomIdentifier [0] + (randomIdentifier [1] << 8));
 123                 }
 124
 125 #if !MONOTOUCH && !ORBIS
 126                 [DllImport ("libc", EntryPoint="capget")]
 127                 static extern int capget (ref cap_user_header_t header, ref cap_user_data_t data);
 128
 129                 static void CheckLinuxCapabilities ()
 130                 {
 131                         try {
 132                                 cap_user_header_t header = new cap_user_header_t ();
 133                                 cap_user_data_t data = new cap_user_data_t ();
 134
 135                                 header.version = linux_cap_version;
 136
 137                                 int ret = -1;
 138
 139                                 try {
 140                                         ret = capget (ref header, ref data);
 141                                 } catch (Exception) {
 142                                 }
 143
 144                                 if (ret == -1)
 145                                         return;
 146
 147                                 canSendPrivileged = (data.effective & (1 << 13)) != 0;
 148                         } catch {
 149                                 canSendPrivileged = false;
 150                         }
 151                 }
 152 #endif
 153
 154                 void IDisposable.Dispose ()
 155                 {
 156                 }
 157
 158                 protected void OnPingCompleted (PingCompletedEventArgs e)
 159                 {
 160                         user_async_state = null;
 161                         worker = null;
 162
 163                         if (cts != null) {
 164                                 cts.Dispose();
 165                                 cts = null;
 166                         }
 167
 168                         if (PingCompleted != null)
 169                                 PingCompleted (this, e);
 170                 }
 171
 172                 // Sync
 173
 174                 public PingReply Send (IPAddress address)
 175                 {
 176                         return Send (address, default_timeout);
 177                 }
 178
 179                 public PingReply Send (IPAddress address, int timeout)
 180                 {
 181                         return Send (address, timeout, default_buffer);
 182                 }
 183
 184                 public PingReply Send (IPAddress address, int timeout, byte [] buffer)
 185                 {
 186                         return Send (address, timeout, buffer, new PingOptions ());
 187                 }
 188
 189                 public PingReply Send (string hostNameOrAddress)
 190                 {
 191                         return Send (hostNameOrAddress, default_timeout);
 192                 }
 193
 194                 public PingReply Send (string hostNameOrAddress, int timeout)
 195                 {
 196                         return Send (hostNameOrAddress, timeout, default_buffer);
 197                 }
 198
 199                 public PingReply Send (string hostNameOrAddress, int timeout, byte [] buffer)
 200                 {
 201                         return Send (hostNameOrAddress, timeout, buffer, new PingOptions ());
 202                 }
 203
 204                 public PingReply Send (string hostNameOrAddress, int timeout, byte [] buffer, PingOptions options)
 205                 {
 206                         IPAddress [] addresses = Dns.GetHostAddresses (hostNameOrAddress);
 207                         return Send (addresses [0], timeout, buffer, options);
 208                 }
 209
 210                 public PingReply Send (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 211                 {
 212                         if (address == null)
 213                                 throw new ArgumentNullException ("address");
 214                         if (timeout < 0)
 215                                 throw new ArgumentOutOfRangeException ("timeout", "timeout must be non-negative integer");
 216                         if (buffer == null)
 217                                 throw new ArgumentNullException ("buffer");
 218                         if (buffer.Length > 65500)
 219                                 throw new ArgumentException ("buffer");
 220                         // options can be null.
 221
 222 #if MONOTOUCH
 223                         throw new InvalidOperationException ();
 224 #else
 225                         if (canSendPrivileged)
 226                                 return SendPrivileged (address, timeout, buffer, options);
 227                         return SendUnprivileged (address, timeout, buffer, options);
 228 #endif
 229                 }
 230
 231 #if !MONOTOUCH
 232                 private PingReply SendPrivileged (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 233                 {
 234                         IPEndPoint target = new IPEndPoint (address, 0);
 235
 236                         // FIXME: support IPv6
 237                         using (Socket s = new Socket (AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp)) {
 238                                 if (options != null) {
 239                                         s.DontFragment = options.DontFragment;
 240                                         s.Ttl = (short) options.Ttl;
 241                                 }
 242                                 s.SendTimeout = timeout;
 243                                 s.ReceiveTimeout = timeout;
 244                                 // not sure why Identifier = 0 is unacceptable ...
 245                                 IcmpMessage send = new IcmpMessage (8, 0, identifier, 0, buffer);
 246                                 byte [] bytes = send.GetBytes ();
 247                                 s.SendBufferSize = bytes.Length;
 248                                 s.SendTo (bytes, bytes.Length, SocketFlags.None, target);
 249
 250                                 DateTime sentTime = DateTime.Now;
 251
 252                                 // receive
 253                                 bytes = new byte [100];
 254                                 do {
 255                                         EndPoint endpoint = target;
 256                                         SocketError error = 0;
 257                                         int rc = s.ReceiveFrom (bytes, 0, 100, SocketFlags.None,
 258                                                         ref endpoint, out error);
 259
 260                                         if (error != SocketError.Success) {
 261                                                 if (error == SocketError.TimedOut) {
 262                                                         return new PingReply (null, new byte [0], options, 0, IPStatus.TimedOut);
 263                                                 }
 264                                                 throw new NotSupportedException (String.Format ("Unexpected socket error during ping request: {0}", error));
 265                                         }
 266                                         long rtt = (long) (DateTime.Now - sentTime).TotalMilliseconds;
 267                                         int headerLength = (bytes [0] & 0xF) << 2;
 268                                         int bodyLength = rc - headerLength;
 269
 270                                         // Ping reply to different request. discard it.
 271                                         if (!((IPEndPoint) endpoint).Address.Equals (target.Address)) {
 272                                                 long t = timeout - rtt;
 273                                                 if (t <= 0)
 274                                                         return new PingReply (null, new byte [0], options, 0, IPStatus.TimedOut);
 275                                                 s.ReceiveTimeout = (int) t;
 276                                                 continue;
 277                                         }
 278
 279                                         IcmpMessage recv = new IcmpMessage (bytes, headerLength, bodyLength);
 280
 281                                         /* discard ping reply to different request or echo requests if running on same host. */
 282                                         if (recv.Identifier != identifier || recv.Type == 8) {
 283                                                 long t = timeout - rtt;
 284                                                 if (t <= 0)
 285                                                         return new PingReply (null, new byte [0], options, 0, IPStatus.TimedOut);
 286                                                 s.ReceiveTimeout = (int) t;
 287                                                 continue;
 288                                         }
 289
 290                                         return new PingReply (address, recv.Data, options, rtt, recv.IPStatus);
 291                                 } while (true);
 292                         }
 293                 }
 294
 295                 private PingReply SendUnprivileged (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 296                 {
 297 #if MONO_FEATURE_PROCESS_START
 298                         DateTime sentTime = DateTime.UtcNow;
 299
 300                         Process ping = new Process ();
 301                         string args = BuildPingArgs (address, timeout, options);
 302                         long trip_time = 0;
 303
 304                         ping.StartInfo.FileName = PingBinPath;
 305                         ping.StartInfo.Arguments = args;
 306
 307                         ping.StartInfo.CreateNoWindow = true;
 308                         ping.StartInfo.UseShellExecute = false;
 309
 310                         ping.StartInfo.RedirectStandardOutput = true;
 311                         ping.StartInfo.RedirectStandardError = true;
 312
 313                         IPStatus status = IPStatus.Unknown;
 314                         try {
 315                                 ping.Start ();
 316
 317 #pragma warning disable 219
 318                                 string stdout = ping.StandardOutput.ReadToEnd ();
 319                                 string stderr = ping.StandardError.ReadToEnd ();
 320 #pragma warning restore 219
 321
 322                                 trip_time = (long) (DateTime.UtcNow - sentTime).TotalMilliseconds;
 323                                 if (!ping.WaitForExit (timeout) || (ping.HasExited && ping.ExitCode == 2))
 324                                         status = IPStatus.TimedOut;
 325                                 else if (ping.ExitCode == 0)
 326                                         status = IPStatus.Success;
 327                                 else if (ping.ExitCode == 1)
 328                                         status = IPStatus.TtlExpired;
 329                         } catch {
 330                         } finally {
 331                                 if (!ping.HasExited)
 332                                         ping.Kill ();
 333                                 ping.Dispose ();
 334                         }
 335
 336                         return new PingReply (address, buffer, options, trip_time, status);
 337 #else
 338                         throw new PlatformNotSupportedException ("Ping is not supported on this platform.");
 339 #endif // MONO_FEATURE_PROCESS_START
 340                 }
 341 #endif // !MONOTOUCH
 342
 343                 // Async
 344
 345                 public void SendAsync (IPAddress address, int timeout, byte [] buffer, object userToken)
 346                 {
 347                         SendAsync (address, default_timeout, default_buffer, new PingOptions (), userToken);
 348                 }
 349
 350                 public void SendAsync (IPAddress address, int timeout, object userToken)
 351                 {
 352                         SendAsync (address, default_timeout, default_buffer, userToken);
 353                 }
 354
 355                 public void SendAsync (IPAddress address, object userToken)
 356                 {
 357                         SendAsync (address, default_timeout, userToken);
 358                 }
 359
 360                 public void SendAsync (string hostNameOrAddress, int timeout, byte [] buffer, object userToken)
 361                 {
 362                         SendAsync (hostNameOrAddress, timeout, buffer, new PingOptions (), userToken);
 363                 }
 364
 365                 public void SendAsync (string hostNameOrAddress, int timeout, byte [] buffer, PingOptions options, object userToken)
 366                 {
 367                         IPAddress address = Dns.GetHostEntry (hostNameOrAddress).AddressList [0];
 368                         SendAsync (address, timeout, buffer, options, userToken);
 369                 }
 370
 371                 public void SendAsync (string hostNameOrAddress, int timeout, object userToken)
 372                 {
 373                         SendAsync (hostNameOrAddress, timeout, default_buffer, userToken);
 374                 }
 375
 376                 public void SendAsync (string hostNameOrAddress, object userToken)
 377                 {
 378                         SendAsync (hostNameOrAddress, default_timeout, userToken);
 379                 }
 380
 381                 public void SendAsync (IPAddress address, int timeout, byte [] buffer, PingOptions options, object userToken)
 382                 {
 383                         if ((worker != null) || (cts != null))
 384                                 throw new InvalidOperationException ("Another SendAsync operation is in progress");
 385
 386                         worker = new BackgroundWorker ();
 387                         worker.DoWork += delegate (object o, DoWorkEventArgs ea) {
 388                                 try {
 389                                         user_async_state = ea.Argument;
 390                                         ea.Result = Send (address, timeout, buffer, options);
 391                                 } catch (Exception ex) {
 392                                         ea.Result = ex;
 393                                 }
 394                         };
 395                         worker.WorkerSupportsCancellation = true;
 396                         worker.RunWorkerCompleted += delegate (object o, RunWorkerCompletedEventArgs ea) {
 397                                 // Note that RunWorkerCompletedEventArgs.UserState cannot be used (LAMESPEC)
 398                                 OnPingCompleted (new PingCompletedEventArgs (ea.Error, ea.Cancelled, user_async_state, ea.Result as PingReply));
 399                         };
 400                         worker.RunWorkerAsync (userToken);
 401                 }
 402
 403                 // SendAsyncCancel
 404
 405                 public void SendAsyncCancel ()
 406                 {
 407                         if (cts != null) {
 408                                 cts.Cancel ();
 409                                 return;
 410                         }
 411
 412                         if (worker == null)
 413                                 throw new InvalidOperationException ("SendAsync operation is not in progress");
 414                         worker.CancelAsync ();
 415                 }
 416
 417 #if !MONOTOUCH
 418                 // ICMP message
 419
 420                 class IcmpMessage
 421                 {
 422                         byte [] bytes;
 423
 424                         // received
 425                         public IcmpMessage (byte [] bytes, int offset, int size)
 426                         {
 427                                 this.bytes = new byte [size];
 428                                 Buffer.BlockCopy (bytes, offset, this.bytes, 0, size);
 429                         }
 430
 431                         // to be sent
 432                         public IcmpMessage (byte type, byte code, ushort identifier, ushort sequence, byte [] data)
 433                         {
 434                                 bytes = new byte [data.Length + 8];
 435                                 bytes [0] = type;
 436                                 bytes [1] = code;
 437                                 bytes [4] = (byte) (identifier & 0xFF);
 438                                 bytes [5] = (byte) ((int) identifier >> 8);
 439                                 bytes [6] = (byte) (sequence & 0xFF);
 440                                 bytes [7] = (byte) ((int) sequence >> 8);
 441                                 Buffer.BlockCopy (data, 0, bytes, 8, data.Length);
 442
 443                                 ushort checksum = ComputeChecksum (bytes);
 444                                 bytes [2] = (byte) (checksum & 0xFF);
 445                                 bytes [3] = (byte) ((int) checksum >> 8);
 446                         }
 447
 448                         public byte Type {
 449                                 get { return bytes [0]; }
 450                         }
 451
 452                         public byte Code {
 453                                 get { return bytes [1]; }
 454                         }
 455
 456                         public ushort Identifier {
 457                                 get { return (ushort) (bytes [4] + (bytes [5] << 8)); }
 458                         }
 459
 460                         public ushort Sequence {
 461                                 get { return (ushort) (bytes [6] + (bytes [7] << 8)); }
 462                         }
 463
 464                         public byte [] Data {
 465                                 get {
 466                                         byte [] data = new byte [bytes.Length - 8];
 467                                         Buffer.BlockCopy (bytes, 8, data, 0, data.Length);
 468                                         return data;
 469                                 }
 470                         }
 471
 472                         public byte [] GetBytes ()
 473                         {
 474                                 return bytes;
 475                         }
 476
 477                         static ushort ComputeChecksum (byte [] data)
 478                         {
 479                                 uint ret = 0;
 480                                 for (int i = 0; i < data.Length; i += 2) {
 481                                         ushort us = i + 1 < data.Length ? data [i + 1] : (byte) 0;
 482                                         us <<= 8;
 483                                         us += data [i];
 484                                         ret += us;
 485                                 }
 486                                 ret = (ret >> 16) + (ret & 0xFFFF);
 487                                 return (ushort) ~ ret;
 488                         }
 489
 490                         public IPStatus IPStatus {
 491                                 get {
 492                                         switch (Type) {
 493                                         case 0:
 494                                                 return IPStatus.Success;
 495                                         case 3: // destination unreacheable
 496                                                 switch (Code) {
 497                                                 case 0:
 498                                                         return IPStatus.DestinationNetworkUnreachable;
 499                                                 case 1:
 500                                                         return IPStatus.DestinationHostUnreachable;
 501                                                 case 2:
 502                                                         return IPStatus.DestinationProtocolUnreachable;
 503                                                 case 3:
 504                                                         return IPStatus.DestinationPortUnreachable;
 505                                                 case 4:
 506                                                         return IPStatus.BadOption; // FIXME: likely wrong
 507                                                 case 5:
 508                                                         return IPStatus.BadRoute; // not sure if it is correct
 509                                                 }
 510                                                 break;
 511                                         case 11:
 512                                                 switch (Code) {
 513                                                 case 0:
 514                                                         return IPStatus.TimeExceeded;
 515                                                 case 1:
 516                                                         return IPStatus.TtlReassemblyTimeExceeded;
 517                                                 }
 518                                                 break;
 519                                         case 12:
 520                                                 return IPStatus.ParameterProblem;
 521                                         case 4:
 522                                                 return IPStatus.SourceQuench;
 523                                         case 8:
 524                                                 return IPStatus.Success;
 525                                         }
 526                                         return IPStatus.Unknown;
 527                                         //throw new NotSupportedException (String.Format ("Unexpected pair of ICMP message type and code: type is {0} and code is {1}", Type, Code));
 528                                 }
 529                         }
 530                 }
 531
 532                 private string BuildPingArgs (IPAddress address, int timeout, PingOptions options)
 533                 {
 534                         CultureInfo culture = CultureInfo.InvariantCulture;
 535                         StringBuilder args = new StringBuilder ();
 536                         uint t = Convert.ToUInt32 (Math.Floor ((timeout + 1000) / 1000.0));
 537                         bool is_mac = Platform.IsMacOS;
 538                         if (!is_mac)
 539                                 args.AppendFormat (culture, "-q -n -c {0} -w {1} -t {2} -M ", DefaultCount, t, options.Ttl);
 540                         else
 541                                 args.AppendFormat (culture, "-q -n -c {0} -t {1} -o -m {2} ", DefaultCount, t, options.Ttl);
 542                         if (!is_mac)
 543                                 args.Append (options.DontFragment ? "do " : "dont ");
 544                         else if (options.DontFragment)
 545                                 args.Append ("-D ");
 546
 547                         args.Append (address.ToString ());
 548
 549                         return args.ToString ();
 550                 }
 551 #endif // !MONOTOUCH
 552
 553                 public Task<PingReply> SendPingAsync (IPAddress address, int timeout, byte [] buffer)
 554                 {
 555                         return SendPingAsync (address, default_timeout, default_buffer, new PingOptions ());
 556                 }
 557
 558                 public Task<PingReply> SendPingAsync (IPAddress address, int timeout)
 559                 {
 560                         return SendPingAsync (address, default_timeout, default_buffer);
 561                 }
 562
 563                 public Task<PingReply> SendPingAsync (IPAddress address)
 564                 {
 565                         return SendPingAsync (address, default_timeout);
 566                 }
 567
 568                 public Task<PingReply> SendPingAsync (string hostNameOrAddress, int timeout, byte [] buffer)
 569                 {
 570                         return SendPingAsync (hostNameOrAddress, timeout, buffer, new PingOptions ());
 571                 }
 572
 573                 public Task<PingReply> SendPingAsync (string hostNameOrAddress, int timeout, byte [] buffer, PingOptions options)
 574                 {
 575                         IPAddress address = Dns.GetHostEntry (hostNameOrAddress).AddressList [0];
 576                         return SendPingAsync (address, timeout, buffer, options);
 577                 }
 578
 579                 public Task<PingReply> SendPingAsync (string hostNameOrAddress, int timeout)
 580                 {
 581                         return SendPingAsync (hostNameOrAddress, timeout, default_buffer);
 582                 }
 583
 584                 public Task<PingReply> SendPingAsync (string hostNameOrAddress)
 585                 {
 586                         return SendPingAsync (hostNameOrAddress, default_timeout);
 587                 }
 588
 589                 public Task<PingReply> SendPingAsync (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 590                 {
 591                         if ((worker != null) || (cts != null))
 592                                 throw new InvalidOperationException ("Another SendAsync operation is in progress");
 593
 594                         cts = new CancellationTokenSource();
 595
 596                         var task = Task<PingReply>.Factory.StartNew (
 597                                 () => Send (address, timeout, buffer, options), cts.Token);
 598
 599                         task.ContinueWith ((t) => {
 600                                 if (t.IsCanceled)
 601                                         OnPingCompleted (new PingCompletedEventArgs (null, true, null, null));
 602                                 else if (t.IsFaulted)
 603                                         OnPingCompleted (new PingCompletedEventArgs (t.Exception, false, null, null));
 604                                 else
 605                                         OnPingCompleted (new PingCompletedEventArgs (null, false, null, t.Result));
 606                         });
 607
 608                         return task;
 609                 }
 610         }
 611 }