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 #endif
  75                 const int default_timeout = 4000; // 4 sec.
  76                 ushort identifier;
  77
  78                 // This value is correct as of Linux kernel version 2.6.25.9
  79                 // See /usr/include/linux/capability.h
  80                 const UInt32 linux_cap_version = 0x20071026;
  81
  82                 static readonly byte [] default_buffer = new byte [0];
  83                 static bool canSendPrivileged;
  84
  85
  86                 BackgroundWorker worker;
  87                 object user_async_state;
  88                 CancellationTokenSource cts;
  89
  90                 public event PingCompletedEventHandler PingCompleted;
  91
  92 #if !MONOTOUCH
  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
 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                         cts = null;
 163
 164                         if (PingCompleted != null)
 165                                 PingCompleted (this, e);
 166                 }
 167
 168                 // Sync
 169
 170                 public PingReply Send (IPAddress address)
 171                 {
 172                         return Send (address, default_timeout);
 173                 }
 174
 175                 public PingReply Send (IPAddress address, int timeout)
 176                 {
 177                         return Send (address, timeout, default_buffer);
 178                 }
 179
 180                 public PingReply Send (IPAddress address, int timeout, byte [] buffer)
 181                 {
 182                         return Send (address, timeout, buffer, new PingOptions ());
 183                 }
 184
 185                 public PingReply Send (string hostNameOrAddress)
 186                 {
 187                         return Send (hostNameOrAddress, default_timeout);
 188                 }
 189
 190                 public PingReply Send (string hostNameOrAddress, int timeout)
 191                 {
 192                         return Send (hostNameOrAddress, timeout, default_buffer);
 193                 }
 194
 195                 public PingReply Send (string hostNameOrAddress, int timeout, byte [] buffer)
 196                 {
 197                         return Send (hostNameOrAddress, timeout, buffer, new PingOptions ());
 198                 }
 199
 200                 public PingReply Send (string hostNameOrAddress, int timeout, byte [] buffer, PingOptions options)
 201                 {
 202                         IPAddress [] addresses = Dns.GetHostAddresses (hostNameOrAddress);
 203                         return Send (addresses [0], timeout, buffer, options);
 204                 }
 205
 206                 static IPAddress GetNonLoopbackIP ()
 207                 {
 208                         foreach (IPAddress addr in Dns.GetHostByName (Dns.GetHostName ()).AddressList)
 209                                 if (!IPAddress.IsLoopback (addr))
 210                                         return addr;
 211                         throw new InvalidOperationException ("Could not resolve non-loopback IP address for localhost");
 212                 }
 213
 214                 public PingReply Send (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 215                 {
 216                         if (address == null)
 217                                 throw new ArgumentNullException ("address");
 218                         if (timeout < 0)
 219                                 throw new ArgumentOutOfRangeException ("timeout", "timeout must be non-negative integer");
 220                         if (buffer == null)
 221                                 throw new ArgumentNullException ("buffer");
 222                         if (buffer.Length > 65500)
 223                                 throw new ArgumentException ("buffer");
 224                         // options can be null.
 225
 226 #if MONOTOUCH
 227                         throw new InvalidOperationException ();
 228 #else
 229                         if (canSendPrivileged)
 230                                 return SendPrivileged (address, timeout, buffer, options);
 231                         return SendUnprivileged (address, timeout, buffer, options);
 232 #endif
 233                 }
 234
 235 #if !MONOTOUCH
 236                 private PingReply SendPrivileged (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 237                 {
 238                         IPEndPoint target = new IPEndPoint (address, 0);
 239                         IPEndPoint client = new IPEndPoint (GetNonLoopbackIP (), 0);
 240
 241                         // FIXME: support IPv6
 242                         using (Socket s = new Socket (AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp)) {
 243                                 if (options != null) {
 244                                         s.DontFragment = options.DontFragment;
 245                                         s.Ttl = (short) options.Ttl;
 246                                 }
 247                                 s.SendTimeout = timeout;
 248                                 s.ReceiveTimeout = timeout;
 249                                 // not sure why Identifier = 0 is unacceptable ...
 250                                 IcmpMessage send = new IcmpMessage (8, 0, identifier, 0, buffer);
 251                                 byte [] bytes = send.GetBytes ();
 252                                 s.SendBufferSize = bytes.Length;
 253                                 s.SendTo (bytes, bytes.Length, SocketFlags.None, target);
 254
 255                                 DateTime sentTime = DateTime.Now;
 256
 257                                 // receive
 258                                 bytes = new byte [100];
 259                                 do {
 260                                         EndPoint endpoint = client;
 261                                         int error = 0;
 262                                         int rc = s.ReceiveFrom_nochecks_exc (bytes, 0, 100, SocketFlags.None,
 263                                                         ref endpoint, false, out error);
 264
 265                                         if (error != 0) {
 266                                                 if (error == (int) SocketError.TimedOut) {
 267                                                         return new PingReply (null, new byte [0], options, 0, IPStatus.TimedOut);
 268                                                 }
 269                                                 throw new NotSupportedException (String.Format ("Unexpected socket error during ping request: {0}", error));
 270                                         }
 271                                         long rtt = (long) (DateTime.Now - sentTime).TotalMilliseconds;
 272                                         int headerLength = (bytes [0] & 0xF) << 2;
 273                                         int bodyLength = rc - headerLength;
 274
 275                                         // Ping reply to different request. discard it.
 276                                         if (!((IPEndPoint) endpoint).Address.Equals (target.Address)) {
 277                                                 long t = timeout - rtt;
 278                                                 if (t <= 0)
 279                                                         return new PingReply (null, new byte [0], options, 0, IPStatus.TimedOut);
 280                                                 s.ReceiveTimeout = (int) t;
 281                                                 continue;
 282                                         }
 283
 284                                         IcmpMessage recv = new IcmpMessage (bytes, headerLength, bodyLength);
 285
 286                                         /* discard ping reply to different request or echo requests if running on same host. */
 287                                         if (recv.Identifier != identifier || recv.Type == 8) {
 288                                                 long t = timeout - rtt;
 289                                                 if (t <= 0)
 290                                                         return new PingReply (null, new byte [0], options, 0, IPStatus.TimedOut);
 291                                                 s.ReceiveTimeout = (int) t;
 292                                                 continue;
 293                                         }
 294
 295                                         return new PingReply (address, recv.Data, options, rtt, recv.IPStatus);
 296                                 } while (true);
 297                         }
 298                 }
 299
 300                 private PingReply SendUnprivileged (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 301                 {
 302 #if MONO_FEATURE_PROCESS_START
 303                         DateTime sentTime = DateTime.UtcNow;
 304
 305                         Process ping = new Process ();
 306                         string args = BuildPingArgs (address, timeout, options);
 307                         long trip_time = 0;
 308
 309                         ping.StartInfo.FileName = PingBinPath;
 310                         ping.StartInfo.Arguments = args;
 311
 312                         ping.StartInfo.CreateNoWindow = true;
 313                         ping.StartInfo.UseShellExecute = false;
 314
 315                         ping.StartInfo.RedirectStandardOutput = true;
 316                         ping.StartInfo.RedirectStandardError = true;
 317
 318                         IPStatus status = IPStatus.Unknown;
 319                         try {
 320                                 ping.Start ();
 321
 322 #pragma warning disable 219
 323                                 string stdout = ping.StandardOutput.ReadToEnd ();
 324                                 string stderr = ping.StandardError.ReadToEnd ();
 325 #pragma warning restore 219
 326
 327                                 trip_time = (long) (DateTime.UtcNow - sentTime).TotalMilliseconds;
 328                                 if (!ping.WaitForExit (timeout) || (ping.HasExited && ping.ExitCode == 2))
 329                                         status = IPStatus.TimedOut;
 330                                 else if (ping.ExitCode == 0)
 331                                         status = IPStatus.Success;
 332                                 else if (ping.ExitCode == 1)
 333                                         status = IPStatus.TtlExpired;
 334                         } catch {
 335                         } finally {
 336                                 if (!ping.HasExited)
 337                                         ping.Kill ();
 338                                 ping.Dispose ();
 339                         }
 340
 341                         return new PingReply (address, buffer, options, trip_time, status);
 342 #else
 343                         throw new NotSupportedException ("Ping is not supported on this platform.");
 344 #endif // MONO_FEATURE_PROCESS_START
 345                 }
 346 #endif // !MONOTOUCH
 347
 348                 // Async
 349
 350                 public void SendAsync (IPAddress address, int timeout, byte [] buffer, object userToken)
 351                 {
 352                         SendAsync (address, default_timeout, default_buffer, new PingOptions (), userToken);
 353                 }
 354
 355                 public void SendAsync (IPAddress address, int timeout, object userToken)
 356                 {
 357                         SendAsync (address, default_timeout, default_buffer, userToken);
 358                 }
 359
 360                 public void SendAsync (IPAddress address, object userToken)
 361                 {
 362                         SendAsync (address, default_timeout, userToken);
 363                 }
 364
 365                 public void SendAsync (string hostNameOrAddress, int timeout, byte [] buffer, object userToken)
 366                 {
 367                         SendAsync (hostNameOrAddress, timeout, buffer, new PingOptions (), userToken);
 368                 }
 369
 370                 public void SendAsync (string hostNameOrAddress, int timeout, byte [] buffer, PingOptions options, object userToken)
 371                 {
 372                         IPAddress address = Dns.GetHostEntry (hostNameOrAddress).AddressList [0];
 373                         SendAsync (address, timeout, buffer, options, userToken);
 374                 }
 375
 376                 public void SendAsync (string hostNameOrAddress, int timeout, object userToken)
 377                 {
 378                         SendAsync (hostNameOrAddress, timeout, default_buffer, userToken);
 379                 }
 380
 381                 public void SendAsync (string hostNameOrAddress, object userToken)
 382                 {
 383                         SendAsync (hostNameOrAddress, default_timeout, userToken);
 384                 }
 385
 386                 public void SendAsync (IPAddress address, int timeout, byte [] buffer, PingOptions options, object userToken)
 387                 {
 388                         if ((worker != null) || (cts != null))
 389                                 throw new InvalidOperationException ("Another SendAsync operation is in progress");
 390
 391                         worker = new BackgroundWorker ();
 392                         worker.DoWork += delegate (object o, DoWorkEventArgs ea) {
 393                                 try {
 394                                         user_async_state = ea.Argument;
 395                                         ea.Result = Send (address, timeout, buffer, options);
 396                                 } catch (Exception ex) {
 397                                         ea.Result = ex;
 398                                 }
 399                         };
 400                         worker.WorkerSupportsCancellation = true;
 401                         worker.RunWorkerCompleted += delegate (object o, RunWorkerCompletedEventArgs ea) {
 402                                 // Note that RunWorkerCompletedEventArgs.UserState cannot be used (LAMESPEC)
 403                                 OnPingCompleted (new PingCompletedEventArgs (ea.Error, ea.Cancelled, user_async_state, ea.Result as PingReply));
 404                         };
 405                         worker.RunWorkerAsync (userToken);
 406                 }
 407
 408                 // SendAsyncCancel
 409
 410                 public void SendAsyncCancel ()
 411                 {
 412                         if (cts != null) {
 413                                 cts.Cancel ();
 414                                 return;
 415                         }
 416
 417                         if (worker == null)
 418                                 throw new InvalidOperationException ("SendAsync operation is not in progress");
 419                         worker.CancelAsync ();
 420                 }
 421
 422 #if !MONOTOUCH
 423                 // ICMP message
 424
 425                 class IcmpMessage
 426                 {
 427                         byte [] bytes;
 428
 429                         // received
 430                         public IcmpMessage (byte [] bytes, int offset, int size)
 431                         {
 432                                 this.bytes = new byte [size];
 433                                 Buffer.BlockCopy (bytes, offset, this.bytes, 0, size);
 434                         }
 435
 436                         // to be sent
 437                         public IcmpMessage (byte type, byte code, ushort identifier, ushort sequence, byte [] data)
 438                         {
 439                                 bytes = new byte [data.Length + 8];
 440                                 bytes [0] = type;
 441                                 bytes [1] = code;
 442                                 bytes [4] = (byte) (identifier & 0xFF);
 443                                 bytes [5] = (byte) ((int) identifier >> 8);
 444                                 bytes [6] = (byte) (sequence & 0xFF);
 445                                 bytes [7] = (byte) ((int) sequence >> 8);
 446                                 Buffer.BlockCopy (data, 0, bytes, 8, data.Length);
 447
 448                                 ushort checksum = ComputeChecksum (bytes);
 449                                 bytes [2] = (byte) (checksum & 0xFF);
 450                                 bytes [3] = (byte) ((int) checksum >> 8);
 451                         }
 452
 453                         public byte Type {
 454                                 get { return bytes [0]; }
 455                         }
 456
 457                         public byte Code {
 458                                 get { return bytes [1]; }
 459                         }
 460
 461                         public ushort Identifier {
 462                                 get { return (ushort) (bytes [4] + (bytes [5] << 8)); }
 463                         }
 464
 465                         public ushort Sequence {
 466                                 get { return (ushort) (bytes [6] + (bytes [7] << 8)); }
 467                         }
 468
 469                         public byte [] Data {
 470                                 get {
 471                                         byte [] data = new byte [bytes.Length - 8];
 472                                         Buffer.BlockCopy (bytes, 8, data, 0, data.Length);
 473                                         return data;
 474                                 }
 475                         }
 476
 477                         public byte [] GetBytes ()
 478                         {
 479                                 return bytes;
 480                         }
 481
 482                         static ushort ComputeChecksum (byte [] data)
 483                         {
 484                                 uint ret = 0;
 485                                 for (int i = 0; i < data.Length; i += 2) {
 486                                         ushort us = i + 1 < data.Length ? data [i + 1] : (byte) 0;
 487                                         us <<= 8;
 488                                         us += data [i];
 489                                         ret += us;
 490                                 }
 491                                 ret = (ret >> 16) + (ret & 0xFFFF);
 492                                 return (ushort) ~ ret;
 493                         }
 494
 495                         public IPStatus IPStatus {
 496                                 get {
 497                                         switch (Type) {
 498                                         case 0:
 499                                                 return IPStatus.Success;
 500                                         case 3: // destination unreacheable
 501                                                 switch (Code) {
 502                                                 case 0:
 503                                                         return IPStatus.DestinationNetworkUnreachable;
 504                                                 case 1:
 505                                                         return IPStatus.DestinationHostUnreachable;
 506                                                 case 2:
 507                                                         return IPStatus.DestinationProtocolUnreachable;
 508                                                 case 3:
 509                                                         return IPStatus.DestinationPortUnreachable;
 510                                                 case 4:
 511                                                         return IPStatus.BadOption; // FIXME: likely wrong
 512                                                 case 5:
 513                                                         return IPStatus.BadRoute; // not sure if it is correct
 514                                                 }
 515                                                 break;
 516                                         case 11:
 517                                                 switch (Code) {
 518                                                 case 0:
 519                                                         return IPStatus.TimeExceeded;
 520                                                 case 1:
 521                                                         return IPStatus.TtlReassemblyTimeExceeded;
 522                                                 }
 523                                                 break;
 524                                         case 12:
 525                                                 return IPStatus.ParameterProblem;
 526                                         case 4:
 527                                                 return IPStatus.SourceQuench;
 528                                         case 8:
 529                                                 return IPStatus.Success;
 530                                         }
 531                                         return IPStatus.Unknown;
 532                                         //throw new NotSupportedException (String.Format ("Unexpected pair of ICMP message type and code: type is {0} and code is {1}", Type, Code));
 533                                 }
 534                         }
 535                 }
 536
 537                 private string BuildPingArgs (IPAddress address, int timeout, PingOptions options)
 538                 {
 539                         CultureInfo culture = CultureInfo.InvariantCulture;
 540                         StringBuilder args = new StringBuilder ();
 541                         uint t = Convert.ToUInt32 (Math.Floor ((timeout + 1000) / 1000.0));
 542                         bool is_mac = Platform.IsMacOS;
 543                         if (!is_mac)
 544                                 args.AppendFormat (culture, "-q -n -c {0} -w {1} -t {2} -M ", DefaultCount, t, options.Ttl);
 545                         else
 546                                 args.AppendFormat (culture, "-q -n -c {0} -t {1} -o -m {2} ", DefaultCount, t, options.Ttl);
 547                         if (!is_mac)
 548                                 args.Append (options.DontFragment ? "do " : "dont ");
 549                         else if (options.DontFragment)
 550                                 args.Append ("-D ");
 551
 552                         args.Append (address.ToString ());
 553
 554                         return args.ToString ();
 555                 }
 556 #endif // !MONOTOUCH
 557
 558                 public Task<PingReply> SendPingAsync (IPAddress address, int timeout, byte [] buffer)
 559                 {
 560                         return SendPingAsync (address, default_timeout, default_buffer, new PingOptions ());
 561                 }
 562
 563                 public Task<PingReply> SendPingAsync (IPAddress address, int timeout)
 564                 {
 565                         return SendPingAsync (address, default_timeout, default_buffer);
 566                 }
 567
 568                 public Task<PingReply> SendPingAsync (IPAddress address)
 569                 {
 570                         return SendPingAsync (address, default_timeout);
 571                 }
 572
 573                 public Task<PingReply> SendPingAsync (string hostNameOrAddress, int timeout, byte [] buffer)
 574                 {
 575                         return SendPingAsync (hostNameOrAddress, timeout, buffer, new PingOptions ());
 576                 }
 577
 578                 public Task<PingReply> SendPingAsync (string hostNameOrAddress, int timeout, byte [] buffer, PingOptions options)
 579                 {
 580                         IPAddress address = Dns.GetHostEntry (hostNameOrAddress).AddressList [0];
 581                         return SendPingAsync (address, timeout, buffer, options);
 582                 }
 583
 584                 public Task<PingReply> SendPingAsync (string hostNameOrAddress, int timeout)
 585                 {
 586                         return SendPingAsync (hostNameOrAddress, timeout, default_buffer);
 587                 }
 588
 589                 public Task<PingReply> SendPingAsync (string hostNameOrAddress)
 590                 {
 591                         return SendPingAsync (hostNameOrAddress, default_timeout);
 592                 }
 593
 594                 public Task<PingReply> SendPingAsync (IPAddress address, int timeout, byte [] buffer, PingOptions options)
 595                 {
 596                         if ((worker != null) || (cts != null))
 597                                 throw new InvalidOperationException ("Another SendAsync operation is in progress");
 598
 599                         var task = Task<PingReply>.Factory.StartNew (
 600                                 () => Send (address, timeout, buffer, options), cts.Token);
 601
 602                         task.ContinueWith ((t) => {
 603                                 if (t.IsCanceled)
 604                                         OnPingCompleted (new PingCompletedEventArgs (null, true, null, null));
 605                                 else if (t.IsFaulted)
 606                                         OnPingCompleted (new PingCompletedEventArgs (t.Exception, false, null, null));
 607                                 else
 608                                         OnPingCompleted (new PingCompletedEventArgs (null, false, null, t.Result));
 609                         });
 610
 611                         return task;
 612                 }
 613         }
 614 }