mcs/class/System/System.Net/FtpWebRequest.cs

   1 //
   2 // System.Net.FtpWebRequest.cs
   3 //
   4 // Authors:
   5 //      Carlos Alberto Cortez (calberto.cortez@gmail.com)
   6 //
   7 // (c) Copyright 2006 Novell, Inc. (http://www.novell.com)
   8 //
   9 #if NET_2_0
  10
  11 using System;
  12 using System.IO;
  13 using System.Net.Sockets;
  14 using System.Text;
  15 using System.Threading;
  16 using System.Net.Cache;
  17 using System.Security.Cryptography.X509Certificates;
  18 using System.Net;
  19
  20
  21 namespace System.Net
  22 {
  23         public sealed class FtpWebRequest : WebRequest
  24         {
  25                 Uri requestUri;
  26                 string file_name; // By now, used for upload
  27                 ServicePoint servicePoint;
  28                 Socket dataSocket;
  29                 NetworkStream controlStream;
  30                 StreamReader controlReader;
  31                 NetworkCredential credentials;
  32                 IPHostEntry hostEntry;
  33                 IPEndPoint localEndPoint;
  34                 IWebProxy proxy;
  35                 int timeout = 100000;
  36                 int rwTimeout = 300000;
  37                 long offset = 0;
  38                 bool binary = true;
  39                 bool enableSsl = false;
  40                 bool usePassive = true;
  41                 bool keepAlive = false;
  42                 string method = WebRequestMethods.Ftp.DownloadFile;
  43                 string renameTo;
  44                 object locker = new object ();
  45
  46                 RequestState requestState = RequestState.Before;
  47                 FtpAsyncResult asyncResult;
  48                 FtpWebResponse ftpResponse;
  49                 Stream requestStream;
  50                 string initial_path;
  51
  52                 const string ChangeDir = "CWD";
  53                 const string UserCommand = "USER";
  54                 const string PasswordCommand = "PASS";
  55                 const string TypeCommand = "TYPE";
  56                 const string PassiveCommand = "PASV";
  57                 const string PortCommand = "PORT";
  58                 const string AbortCommand = "ABOR";
  59                 const string AuthCommand = "AUTH";
  60                 const string RestCommand = "REST";
  61                 const string RenameFromCommand = "RNFR";
  62                 const string RenameToCommand = "RNTO";
  63                 const string QuitCommand = "QUIT";
  64                 const string EOL = "\r\n"; // Special end of line
  65
  66                 enum RequestState
  67                 {
  68                         Before,
  69                         Scheduled,
  70                         Connecting,
  71                         Authenticating,
  72                         OpeningData,
  73                         TransferInProgress,
  74                         Finished,
  75                         Aborted,
  76                         Error
  77                 }
  78
  79                 // sorted commands
  80                 static readonly string [] supportedCommands = new string [] {
  81                         WebRequestMethods.Ftp.AppendFile, // APPE
  82                         WebRequestMethods.Ftp.DeleteFile, // DELE
  83                         WebRequestMethods.Ftp.ListDirectoryDetails, // LIST
  84                         WebRequestMethods.Ftp.GetDateTimestamp, // MDTM
  85                         WebRequestMethods.Ftp.MakeDirectory, // MKD
  86                         WebRequestMethods.Ftp.ListDirectory, // NLST
  87                         WebRequestMethods.Ftp.PrintWorkingDirectory, // PWD
  88                         WebRequestMethods.Ftp.Rename, // RENAME
  89                         WebRequestMethods.Ftp.DownloadFile, // RETR
  90                         WebRequestMethods.Ftp.RemoveDirectory, // RMD
  91                         WebRequestMethods.Ftp.GetFileSize, // SIZE
  92                         WebRequestMethods.Ftp.UploadFile, // STOR
  93                         WebRequestMethods.Ftp.UploadFileWithUniqueName // STUR
  94                         };
  95
  96                 internal FtpWebRequest (Uri uri)
  97                 {
  98                         this.requestUri = uri;
  99                         this.proxy = GlobalProxySelection.Select;
 100                 }
 101
 102                 static Exception GetMustImplement ()
 103                 {
 104                         return new NotImplementedException ();
 105                 }
 106
 107                 [MonoTODO]
 108                 public X509CertificateCollection ClientCertificates
 109                 {
 110                         get {
 111                                 throw GetMustImplement ();
 112                         }
 113                         set {
 114                                 throw GetMustImplement ();
 115                         }
 116                 }
 117
 118                 [MonoTODO]
 119                 public override string ConnectionGroupName
 120                 {
 121                         get {
 122                                 throw GetMustImplement ();
 123                         }
 124                         set {
 125                                 throw GetMustImplement ();
 126                         }
 127                 }
 128
 129                 public override string ContentType {
 130                         get {
 131                                 throw new NotSupportedException ();
 132                         }
 133                         set {
 134                                 throw new NotSupportedException ();
 135                         }
 136                 }
 137
 138                 public override long ContentLength {
 139                         get {
 140                                 return 0;
 141                         }
 142                         set {
 143                                 // DO nothing
 144                         }
 145                 }
 146
 147                 public long ContentOffset {
 148                         get {
 149                                 return offset;
 150                         }
 151                         set {
 152                                 CheckRequestStarted ();
 153                                 if (value < 0)
 154                                         throw new ArgumentOutOfRangeException ();
 155
 156                                 offset = value;
 157                         }
 158                 }
 159
 160                 public override ICredentials Credentials {
 161                         get {
 162                                 return credentials;
 163                         }
 164                         set {
 165                                 CheckRequestStarted ();
 166                                 if (value == null)
 167                                         throw new ArgumentNullException ();
 168                                 if (!(value is NetworkCredential))
 169                                         throw new ArgumentException ();
 170
 171                                 credentials = value as NetworkCredential;
 172                         }
 173                 }
 174
 175                 [MonoTODO]
 176                 public static new RequestCachePolicy DefaultCachePolicy
 177                 {
 178                         get {
 179                                 throw GetMustImplement ();
 180                         }
 181                         set {
 182                                 throw GetMustImplement ();
 183                         }
 184                 }
 185
 186                 public bool EnableSsl {
 187                         get {
 188                                 return enableSsl;
 189                         }
 190                         set {
 191                                 CheckRequestStarted ();
 192                                 enableSsl = value;
 193                         }
 194                 }
 195
 196                 [MonoTODO]
 197                 public override WebHeaderCollection Headers
 198                 {
 199                         get {
 200                                 throw GetMustImplement ();
 201                         }
 202                         set {
 203                                 throw GetMustImplement ();
 204                         }
 205                 }
 206
 207                 public bool KeepAlive {
 208                         get {
 209                                 return keepAlive;
 210                         }
 211                         set {
 212                                 CheckRequestStarted ();
 213                                 keepAlive = value;
 214                         }
 215                 }
 216
 217                 public override string Method {
 218                         get {
 219                                 return method;
 220                         }
 221                         set {
 222                                 CheckRequestStarted ();
 223                                 if (value == null)
 224                                         throw new ArgumentNullException ("Method string cannot be null");
 225
 226                                 if (value.Length == 0 || Array.BinarySearch (supportedCommands, value) < 0)
 227                                         throw new ArgumentException ("Method not supported", "value");
 228
 229                                 method = value;
 230                         }
 231                 }
 232
 233                 public override bool PreAuthenticate {
 234                         get {
 235                                 throw new NotSupportedException ();
 236                         }
 237                         set {
 238                                 throw new NotSupportedException ();
 239                         }
 240                 }
 241
 242                 public override IWebProxy Proxy {
 243                         get {
 244                                 return proxy;
 245                         }
 246                         set {
 247                                 CheckRequestStarted ();
 248                                 if (value == null)
 249                                         throw new ArgumentNullException ();
 250
 251                                 proxy = value;
 252                         }
 253                 }
 254
 255                 public int ReadWriteTimeout {
 256                         get {
 257                                 return rwTimeout;
 258                         }
 259                         set {
 260                                 CheckRequestStarted ();
 261
 262                                 if (value < - 1)
 263                                         throw new ArgumentOutOfRangeException ();
 264                                 else
 265                                         rwTimeout = value;
 266                         }
 267                 }
 268
 269                 public string RenameTo {
 270                         get {
 271                                 return renameTo;
 272                         }
 273                         set {
 274                                 CheckRequestStarted ();
 275                                 if (value == null || value.Length == 0)
 276                                         throw new ArgumentException ("RenameTo value can't be null or empty", "RenameTo");
 277
 278                                 renameTo = value;
 279                         }
 280                 }
 281
 282                 public override Uri RequestUri {
 283                         get {
 284                                 return requestUri;
 285                         }
 286                 }
 287
 288                 public ServicePoint ServicePoint {
 289                         get {
 290                                 return GetServicePoint ();
 291                         }
 292                 }
 293
 294                 public bool UsePassive {
 295                         get {
 296                                 return usePassive;
 297                         }
 298                         set {
 299                                 CheckRequestStarted ();
 300                                 usePassive = value;
 301                         }
 302                 }
 303
 304                 [MonoTODO]
 305                 public override bool UseDefaultCredentials
 306                 {
 307                         get {
 308                                 throw GetMustImplement ();
 309                         }
 310                         set {
 311                                 throw GetMustImplement ();
 312                         }
 313                 }
 314
 315                 public bool UseBinary {
 316                         get {
 317                                 return binary;
 318                         } set {
 319                                 CheckRequestStarted ();
 320                                 binary = value;
 321                         }
 322                 }
 323
 324                 public override int Timeout {
 325                         get {
 326                                 return timeout;
 327                         }
 328                         set {
 329                                 CheckRequestStarted ();
 330
 331                                 if (value < -1)
 332                                         throw new ArgumentOutOfRangeException ();
 333                                 else
 334                                         timeout = value;
 335                         }
 336                 }
 337
 338                 string DataType {
 339                         get {
 340                                 return binary ? "I" : "A";
 341                         }
 342                 }
 343
 344                 RequestState State {
 345                         get {
 346                                 lock (locker) {
 347                                         return requestState;
 348                                 }
 349                         }
 350
 351                         set {
 352                                 lock (locker) {
 353                                         CheckIfAborted ();
 354                                         CheckFinalState ();
 355                                         requestState = value;
 356                                 }
 357                         }
 358                 }
 359
 360                 public override void Abort () {
 361                         lock (locker) {
 362                                 if (State == RequestState.TransferInProgress) {
 363                                         /*FtpStatus status = */
 364                                         SendCommand (false, AbortCommand);
 365                                 }
 366
 367                                 if (!InFinalState ()) {
 368                                         State = RequestState.Aborted;
 369                                         ftpResponse = new FtpWebResponse (requestUri, method, FtpStatusCode.FileActionAborted, "Aborted by request");
 370                                 }
 371                         }
 372                 }
 373
 374                 public override IAsyncResult BeginGetResponse (AsyncCallback callback, object state) {
 375                         if (asyncResult != null && !asyncResult.IsCompleted) {
 376                                 throw new InvalidOperationException ("Cannot re-call BeginGetRequestStream/BeginGetResponse while a previous call is still in progress");
 377                         }
 378
 379                         CheckIfAborted ();
 380
 381                         asyncResult = new FtpAsyncResult (callback, state);
 382
 383                         lock (locker) {
 384                                 if (InFinalState ())
 385                                         asyncResult.SetCompleted (true, ftpResponse);
 386                                 else {
 387                                         if (State == RequestState.Before)
 388                                                 State = RequestState.Scheduled;
 389
 390                                         Thread thread = new Thread (ProcessRequest);
 391                                         thread.Start ();
 392                                 }
 393                         }
 394
 395                         return asyncResult;
 396                 }
 397
 398                 public override WebResponse EndGetResponse (IAsyncResult asyncResult) {
 399                         if (asyncResult == null)
 400                                 throw new ArgumentNullException ("AsyncResult cannot be null!");
 401
 402                         if (!(asyncResult is FtpAsyncResult) || asyncResult != this.asyncResult)
 403                                 throw new ArgumentException ("AsyncResult is from another request!");
 404
 405                         FtpAsyncResult asyncFtpResult = (FtpAsyncResult) asyncResult;
 406                         if (!asyncFtpResult.WaitUntilComplete (timeout, false)) {
 407                                 Abort ();
 408                                 throw new WebException ("Transfer timed out.", WebExceptionStatus.Timeout);
 409                         }
 410
 411                         CheckIfAborted ();
 412
 413                         asyncResult = null;
 414
 415                         if (asyncFtpResult.GotException)
 416                                 throw asyncFtpResult.Exception;
 417
 418                         return asyncFtpResult.Response;
 419                 }
 420
 421                 public override WebResponse GetResponse () {
 422                         IAsyncResult asyncResult = BeginGetResponse (null, null);
 423                         return EndGetResponse (asyncResult);
 424                 }
 425
 426                 public override IAsyncResult BeginGetRequestStream (AsyncCallback callback, object state) {
 427                         if (method != WebRequestMethods.Ftp.UploadFile && method != WebRequestMethods.Ftp.UploadFileWithUniqueName &&
 428                                         method != WebRequestMethods.Ftp.AppendFile)
 429                                 throw new ProtocolViolationException ();
 430
 431                         lock (locker) {
 432                                 CheckIfAborted ();
 433
 434                                 if (State != RequestState.Before)
 435                                         throw new InvalidOperationException ("Cannot re-call BeginGetRequestStream/BeginGetResponse while a previous call is still in progress");
 436
 437                                 State = RequestState.Scheduled;
 438                         }
 439
 440                         asyncResult = new FtpAsyncResult (callback, state);
 441                         Thread thread = new Thread (ProcessRequest);
 442                         thread.Start ();
 443
 444                         return asyncResult;
 445                 }
 446
 447                 public override Stream EndGetRequestStream (IAsyncResult asyncResult) {
 448                         if (asyncResult == null)
 449                                 throw new ArgumentNullException ("asyncResult");
 450
 451                         if (!(asyncResult is FtpAsyncResult))
 452                                 throw new ArgumentException ("asyncResult");
 453
 454                         if (State == RequestState.Aborted) {
 455                                 throw new WebException ("Request aborted", WebExceptionStatus.RequestCanceled);
 456                         }
 457
 458                         if (asyncResult != this.asyncResult)
 459                                 throw new ArgumentException ("AsyncResult is from another request!");
 460
 461                         FtpAsyncResult res = (FtpAsyncResult) asyncResult;
 462
 463                         if (!res.WaitUntilComplete (timeout, false)) {
 464                                 Abort ();
 465                                 throw new WebException ("Request timed out");
 466                         }
 467
 468                         if (res.GotException)
 469                                 throw res.Exception;
 470
 471                         return res.Stream;
 472                 }
 473
 474                 public override Stream GetRequestStream () {
 475                         IAsyncResult asyncResult = BeginGetRequestStream (null, null);
 476                         return EndGetRequestStream (asyncResult);
 477                 }
 478
 479                 ServicePoint GetServicePoint ()
 480                 {
 481                         if (servicePoint == null)
 482                                 servicePoint = ServicePointManager.FindServicePoint (requestUri, proxy);
 483
 484                         return servicePoint;
 485                 }
 486
 487                 // Probably move some code of command connection here
 488                 void ResolveHost ()
 489                 {
 490                         CheckIfAborted ();
 491                         hostEntry = GetServicePoint ().HostEntry;
 492
 493                         if (hostEntry == null) {
 494                                 ftpResponse.UpdateStatus (new FtpStatus(FtpStatusCode.ActionAbortedLocalProcessingError, "Cannot resolve server name"));
 495                                 throw new WebException ("The remote server name could not be resolved: " + requestUri,
 496                                         null, WebExceptionStatus.NameResolutionFailure, ftpResponse);
 497                         }
 498                 }
 499
 500                 void ProcessRequest () {
 501
 502                         if (State == RequestState.Scheduled) {
 503                                 ftpResponse = new FtpWebResponse (requestUri, method, keepAlive);
 504
 505                                 try {
 506                                         ProcessMethod ();
 507                                         //State = RequestState.Finished;
 508                                         //finalResponse = ftpResponse;
 509                                         asyncResult.SetCompleted (false, ftpResponse);
 510                                 }
 511                                 catch (Exception e) {
 512                                         State = RequestState.Error;
 513                                         SetCompleteWithError (e);
 514                                 }
 515                         }
 516                         else {
 517                                 if (InProgress ()) {
 518                                         FtpStatus status = GetResponseStatus ();
 519
 520                                         ftpResponse.UpdateStatus (status);
 521
 522                                         if (ftpResponse.IsFinal ()) {
 523                                                 State = RequestState.Finished;
 524                                         }
 525                                 }
 526
 527                                 asyncResult.SetCompleted (false, ftpResponse);
 528                         }
 529                 }
 530
 531                 void SetType ()
 532                 {
 533                         if (binary) {
 534                                 FtpStatus status = SendCommand (TypeCommand, DataType);
 535                                 if ((int) status.StatusCode < 200 || (int) status.StatusCode >= 300)
 536                                         throw CreateExceptionFromResponse (status);
 537                         }
 538                 }
 539
 540                 string GetRemoteFolderPath (Uri uri)
 541                 {
 542                         string result;
 543                         string local_path = Uri.UnescapeDataString (uri.LocalPath);
 544                         if (initial_path == null || initial_path == "/") {
 545                                 result = local_path;
 546                         } else {
 547                                 if (local_path [0] == '/')
 548                                         local_path = local_path.Substring (1);
 549
 550                                 Uri initial = new Uri ("ftp://dummy-host" + initial_path);
 551                                 result = new Uri (initial, local_path).LocalPath;
 552                         }
 553
 554                         int last = result.LastIndexOf ('/');
 555                         if (last == -1)
 556                                 return null;
 557
 558                         return result.Substring (0, last + 1);
 559                 }
 560
 561                 void CWDAndSetFileName (Uri uri)
 562                 {
 563                         string remote_folder = GetRemoteFolderPath (uri);
 564                         FtpStatus status;
 565                         if (remote_folder != null) {
 566                                 status = SendCommand (ChangeDir, remote_folder);
 567                                 if ((int) status.StatusCode < 200 || (int) status.StatusCode >= 300)
 568                                         throw CreateExceptionFromResponse (status);
 569
 570                                 int last = uri.LocalPath.LastIndexOf ('/');
 571                                 if (last >= 0) {
 572                                         file_name = Uri.UnescapeDataString (uri.LocalPath.Substring (last + 1));
 573                                 }
 574                         }
 575                 }
 576
 577                 void ProcessMethod ()
 578                 {
 579                         State = RequestState.Connecting;
 580
 581                         ResolveHost ();
 582
 583                         OpenControlConnection ();
 584                         CWDAndSetFileName (requestUri);
 585                         SetType ();
 586
 587                         switch (method) {
 588                         // Open data connection and receive data
 589                         case WebRequestMethods.Ftp.DownloadFile:
 590                         case WebRequestMethods.Ftp.ListDirectory:
 591                         case WebRequestMethods.Ftp.ListDirectoryDetails:
 592                                 DownloadData ();
 593                                 break;
 594                         // Open data connection and send data
 595                         case WebRequestMethods.Ftp.AppendFile:
 596                         case WebRequestMethods.Ftp.UploadFile:
 597                         case WebRequestMethods.Ftp.UploadFileWithUniqueName:
 598                                 UploadData ();
 599                                 break;
 600                         // Get info from control connection
 601                         case WebRequestMethods.Ftp.GetFileSize:
 602                         case WebRequestMethods.Ftp.GetDateTimestamp:
 603                         case WebRequestMethods.Ftp.PrintWorkingDirectory:
 604                         case WebRequestMethods.Ftp.MakeDirectory:
 605                         case WebRequestMethods.Ftp.Rename:
 606                         case WebRequestMethods.Ftp.DeleteFile:
 607                                 ProcessSimpleMethod ();
 608                                 break;
 609                         default: // What to do here?
 610                                 throw new Exception (String.Format ("Support for command {0} not implemented yet", method));
 611                         }
 612
 613                         CheckIfAborted ();
 614                 }
 615
 616                 private void CloseControlConnection () {
 617                         SendCommand (QuitCommand);
 618                         controlStream.Close ();
 619                 }
 620
 621                 private void CloseDataConnection () {
 622                         if(dataSocket != null)
 623                                 dataSocket.Close ();
 624                 }
 625
 626                 private void CloseConnection () {
 627                         CloseControlConnection ();
 628                         CloseDataConnection ();
 629                 }
 630
 631                 void ProcessSimpleMethod ()
 632                 {
 633                         State = RequestState.TransferInProgress;
 634
 635                         FtpStatus status;
 636
 637                         if (method == WebRequestMethods.Ftp.PrintWorkingDirectory)
 638                                 method = "PWD";
 639
 640                         if (method == WebRequestMethods.Ftp.Rename)
 641                                 method = RenameFromCommand;
 642
 643                         status = SendCommand (method, file_name);
 644
 645                         ftpResponse.Stream = new EmptyStream ();
 646
 647                         string desc = status.StatusDescription;
 648
 649                         switch (method) {
 650                         case WebRequestMethods.Ftp.GetFileSize: {
 651                                         if (status.StatusCode != FtpStatusCode.FileStatus)
 652                                                 throw CreateExceptionFromResponse (status);
 653
 654                                         int i, len;
 655                                         long size;
 656                                         for (i = 4, len = 0; i < desc.Length && Char.IsDigit (desc [i]); i++, len++)
 657                                                 ;
 658
 659                                         if (len == 0)
 660                                                 throw new WebException ("Bad format for server response in " + method);
 661
 662                                         if (!Int64.TryParse (desc.Substring (4, len), out size))
 663                                                 throw new WebException ("Bad format for server response in " + method);
 664
 665                                         ftpResponse.contentLength = size;
 666                                 }
 667                                 break;
 668                         case WebRequestMethods.Ftp.GetDateTimestamp:
 669                                 if (status.StatusCode != FtpStatusCode.FileStatus)
 670                                         throw CreateExceptionFromResponse (status);
 671                                 ftpResponse.LastModified = DateTime.ParseExact (desc.Substring (4), "yyyyMMddHHmmss", null);
 672                                 break;
 673                         case WebRequestMethods.Ftp.MakeDirectory:
 674                                 if (status.StatusCode != FtpStatusCode.PathnameCreated)
 675                                         throw CreateExceptionFromResponse (status);
 676                                 break;
 677                         case ChangeDir:
 678                                 method = WebRequestMethods.Ftp.PrintWorkingDirectory;
 679
 680                                 if (status.StatusCode != FtpStatusCode.FileActionOK)
 681                                         throw CreateExceptionFromResponse (status);
 682
 683                                 status = SendCommand (method);
 684
 685                                 if (status.StatusCode != FtpStatusCode.PathnameCreated)
 686                                         throw CreateExceptionFromResponse (status);
 687                                 break;
 688                         case RenameFromCommand:
 689                                 method = WebRequestMethods.Ftp.Rename;
 690                                 if (status.StatusCode != FtpStatusCode.FileCommandPending)
 691                                         throw CreateExceptionFromResponse (status);
 692                                 // Pass an empty string if RenameTo wasn't specified
 693                                 status = SendCommand (RenameToCommand, renameTo != null ? renameTo : String.Empty);
 694                                 if (status.StatusCode != FtpStatusCode.FileActionOK)
 695                                         throw CreateExceptionFromResponse (status);
 696                                 break;
 697                         case WebRequestMethods.Ftp.DeleteFile:
 698                                 if (status.StatusCode != FtpStatusCode.FileActionOK)  {
 699                                         throw CreateExceptionFromResponse (status);
 700                                 }
 701                                 break;
 702                         }
 703
 704                         State = RequestState.Finished;
 705                 }
 706
 707                 void UploadData ()
 708                 {
 709                         State = RequestState.OpeningData;
 710
 711                         OpenDataConnection ();
 712
 713                         State = RequestState.TransferInProgress;
 714                         requestStream = new FtpDataStream (this, dataSocket, false);
 715                         asyncResult.Stream = requestStream;
 716                 }
 717
 718                 void DownloadData ()
 719                 {
 720                         State = RequestState.OpeningData;
 721
 722                         // Handle content offset
 723                         if (offset > 0) {
 724                                 FtpStatus status = SendCommand (RestCommand, offset.ToString ());
 725
 726                                 if (status.StatusCode != FtpStatusCode.FileCommandPending)
 727                                         throw CreateExceptionFromResponse (status);
 728                         }
 729
 730                         OpenDataConnection ();
 731
 732                         State = RequestState.TransferInProgress;
 733                         ftpResponse.Stream = new FtpDataStream (this, dataSocket, true);
 734                 }
 735
 736                 void CheckRequestStarted ()
 737                 {
 738                         if (State != RequestState.Before)
 739                                 throw new InvalidOperationException ("There is a request currently in progress");
 740                 }
 741
 742                 void OpenControlConnection ()
 743                 {
 744                         Exception exception = null;
 745                         Socket sock = null;
 746                         foreach (IPAddress address in hostEntry.AddressList) {
 747                                 sock = new Socket (address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
 748
 749                                 IPEndPoint remote = new IPEndPoint (address, requestUri.Port);
 750
 751                                 if (!ServicePoint.CallEndPointDelegate (sock, remote)) {
 752                                         sock.Close ();
 753                                         sock = null;
 754                                 } else {
 755                                         try {
 756                                                 sock.Connect (remote);
 757                                                 localEndPoint = (IPEndPoint) sock.LocalEndPoint;
 758                                                 break;
 759                                         } catch (SocketException exc) {
 760                                                 exception = exc;
 761                                                 sock.Close ();
 762                                                 sock = null;
 763                                         }
 764                                 }
 765                         }
 766
 767                         // Couldn't connect to any address
 768                         if (sock == null)
 769                                 throw new WebException ("Unable to connect to remote server", exception,
 770                                                 WebExceptionStatus.UnknownError, ftpResponse);
 771
 772                         controlStream = new NetworkStream (sock);
 773                         controlReader = new StreamReader (controlStream, Encoding.ASCII);
 774
 775                         State = RequestState.Authenticating;
 776
 777                         Authenticate ();
 778                         FtpStatus status = SendCommand ("OPTS", "utf8", "on");
 779                         // ignore status for OPTS
 780                         status = SendCommand (WebRequestMethods.Ftp.PrintWorkingDirectory);
 781                         initial_path = GetInitialPath (status);
 782                 }
 783
 784                 static string GetInitialPath (FtpStatus status)
 785                 {
 786                         int s = (int) status.StatusCode;
 787                         if (s < 200 || s > 300 || status.StatusDescription.Length <= 4)
 788                                 throw new WebException ("Error getting current directory: " + status.StatusDescription, null,
 789                                                 WebExceptionStatus.UnknownError, null);
 790
 791                         string msg = status.StatusDescription.Substring (4);
 792                         if (msg [0] == '"') {
 793                                 int next_quote = msg.IndexOf ('\"', 1);
 794                                 if (next_quote == -1)
 795                                         throw new WebException ("Error getting current directory: PWD -> " + status.StatusDescription, null,
 796                                                                 WebExceptionStatus.UnknownError, null);
 797
 798                                 msg = msg.Substring (1, next_quote - 1);
 799                         }
 800
 801                         if (!msg.EndsWith ("/"))
 802                                 msg += "/";
 803                         return msg;
 804                 }
 805
 806                 // Probably we could do better having here a regex
 807                 Socket SetupPassiveConnection (string statusDescription)
 808                 {
 809                         // Current response string
 810                         string response = statusDescription;
 811                         if (response.Length < 4)
 812                                 throw new WebException ("Cannot open passive data connection");
 813
 814                         // Look for first digit after code
 815                         int i;
 816                         for (i = 3; i < response.Length && !Char.IsDigit (response [i]); i++)
 817                                 ;
 818                         if (i >= response.Length)
 819                                 throw new WebException ("Cannot open passive data connection");
 820
 821                         // Get six elements
 822                         string [] digits = response.Substring (i).Split (new char [] {','}, 6);
 823                         if (digits.Length != 6)
 824                                 throw new WebException ("Cannot open passive data connection");
 825
 826                         // Clean non-digits at the end of last element
 827                         int j;
 828                         for (j = digits [5].Length - 1; j >= 0 && !Char.IsDigit (digits [5][j]); j--)
 829                                 ;
 830                         if (j < 0)
 831                                 throw new WebException ("Cannot open passive data connection");
 832
 833                         digits [5] = digits [5].Substring (0, j + 1);
 834
 835                         IPAddress ip;
 836                         try {
 837                                 ip = IPAddress.Parse (String.Join (".", digits, 0, 4));
 838                         } catch (FormatException) {
 839                                 throw new WebException ("Cannot open passive data connection");
 840                         }
 841
 842                         // Get the port
 843                         int p1, p2, port;
 844                         if (!Int32.TryParse (digits [4], out p1) || !Int32.TryParse (digits [5], out p2))
 845                                 throw new WebException ("Cannot open passive data connection");
 846
 847                         port = (p1 << 8) + p2; // p1 * 256 + p2
 848                         //port = p1 * 256 + p2;
 849                         if (port < IPEndPoint.MinPort || port > IPEndPoint.MaxPort)
 850                                 throw new WebException ("Cannot open passive data connection");
 851
 852                         IPEndPoint ep = new IPEndPoint (ip, port);
 853                         Socket sock = new Socket (ep.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
 854                         try {
 855                                 sock.Connect (ep);
 856                         } catch (SocketException) {
 857                                 sock.Close ();
 858                                 throw new WebException ("Cannot open passive data connection");
 859                         }
 860
 861                         return sock;
 862                 }
 863
 864                 Exception CreateExceptionFromResponse (FtpStatus status)
 865                 {
 866                         FtpWebResponse ftpResponse = new FtpWebResponse (requestUri, method, status);
 867
 868                         WebException exc = new WebException ("Server returned an error: " + status.StatusDescription,
 869                                 null, WebExceptionStatus.ProtocolError, ftpResponse);
 870                         return exc;
 871                 }
 872
 873                 // Here we could also get a server error, so be cautious
 874                 internal void SetTransferCompleted ()
 875                 {
 876                         if (InFinalState ())
 877                                 return;
 878
 879                         State = RequestState.Finished;
 880                         FtpStatus status = GetResponseStatus ();
 881                         ftpResponse.UpdateStatus (status);
 882                         if(!keepAlive)
 883                                 CloseConnection ();
 884                 }
 885
 886                 void SetCompleteWithError (Exception exc)
 887                 {
 888                         if (asyncResult != null) {
 889                                 asyncResult.SetCompleted (false, exc);
 890                         }
 891                 }
 892
 893                 Socket InitDataConnection ()
 894                 {
 895                         FtpStatus status;
 896
 897                         if (usePassive) {
 898                                 status = SendCommand (PassiveCommand);
 899                                 if (status.StatusCode != FtpStatusCode.EnteringPassive) {
 900                                         throw CreateExceptionFromResponse (status);
 901                                 }
 902
 903                                 return SetupPassiveConnection (status.StatusDescription);
 904                         }
 905
 906                         // Open a socket to listen the server's connection
 907                         Socket sock = new Socket (AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
 908                         try {
 909                                 sock.Bind (new IPEndPoint (localEndPoint.Address, 0));
 910                                 sock.Listen (1); // We only expect a connection from server
 911
 912                         } catch (SocketException e) {
 913                                 sock.Close ();
 914
 915                                 throw new WebException ("Couldn't open listening socket on client", e);
 916                         }
 917
 918                         IPEndPoint ep = (IPEndPoint) sock.LocalEndPoint;
 919                         string ipString = ep.Address.ToString ().Replace ('.', ',');
 920                         int h1 = ep.Port >> 8; // ep.Port / 256
 921                         int h2 = ep.Port % 256;
 922
 923                         string portParam = ipString + "," + h1 + "," + h2;
 924                         status = SendCommand (PortCommand, portParam);
 925
 926                         if (status.StatusCode != FtpStatusCode.CommandOK) {
 927                                 sock.Close ();
 928                                 throw (CreateExceptionFromResponse (status));
 929                         }
 930
 931                         return sock;
 932                 }
 933
 934                 void OpenDataConnection ()
 935                 {
 936                         FtpStatus status;
 937
 938                         Socket s = InitDataConnection ();
 939
 940                         if (method != WebRequestMethods.Ftp.ListDirectory && method != WebRequestMethods.Ftp.ListDirectoryDetails &&
 941                             method != WebRequestMethods.Ftp.UploadFileWithUniqueName) {
 942                                 status = SendCommand (method, file_name);
 943                         } else {
 944                                 status = SendCommand (method);
 945                         }
 946
 947                         if (status.StatusCode != FtpStatusCode.OpeningData && status.StatusCode != FtpStatusCode.DataAlreadyOpen)
 948                                 throw CreateExceptionFromResponse (status);
 949
 950                         if (usePassive) {
 951                                 dataSocket = s;
 952                         }
 953                         else {
 954
 955                                 // Active connection (use Socket.Blocking to true)
 956                                 Socket incoming = null;
 957                                 try {
 958                                         incoming = s.Accept ();
 959                                 }
 960                                 catch (SocketException) {
 961                                         s.Close ();
 962                                         if (incoming != null)
 963                                                 incoming.Close ();
 964
 965                                         throw new ProtocolViolationException ("Server commited a protocol violation.");
 966                                 }
 967
 968                                 s.Close ();
 969                                 dataSocket = incoming;
 970                         }
 971
 972                         if (EnableSsl) {
 973                                 InitiateSecureConnection (ref controlStream);
 974                                 controlReader = new StreamReader (controlStream, Encoding.ASCII);
 975                         }
 976
 977                         ftpResponse.UpdateStatus (status);
 978                 }
 979
 980                 void Authenticate ()
 981                 {
 982                         string username = null;
 983                         string password = null;
 984                         string domain = null;
 985
 986                         if (credentials != null) {
 987                                 username = credentials.UserName;
 988                                 password = credentials.Password;
 989                                 domain = credentials.Domain;
 990                         }
 991
 992                         if (username == null)
 993                                 username = "anonymous";
 994                         if (password == null)
 995                                 password = "@anonymous";
 996                         if (!string.IsNullOrEmpty (domain))
 997                                 username = domain + '\\' + username;
 998
 999                         // Connect to server and get banner message
1000                         FtpStatus status = GetResponseStatus ();
1001                         ftpResponse.BannerMessage = status.StatusDescription;
1002
1003                         if (EnableSsl) {
1004                                 InitiateSecureConnection (ref controlStream);
1005                                 controlReader = new StreamReader (controlStream, Encoding.ASCII);
1006                         }
1007
1008                         if (status.StatusCode != FtpStatusCode.SendUserCommand)
1009                                 throw CreateExceptionFromResponse (status);
1010
1011                         status = SendCommand (UserCommand, username);
1012
1013                         switch (status.StatusCode) {
1014                         case FtpStatusCode.SendPasswordCommand:
1015                                 status = SendCommand (PasswordCommand, password);
1016                                 if (status.StatusCode != FtpStatusCode.LoggedInProceed)
1017                                         throw CreateExceptionFromResponse (status);
1018                                 break;
1019                         case FtpStatusCode.LoggedInProceed:
1020                                 break;
1021                         default:
1022                                 throw CreateExceptionFromResponse (status);
1023                         }
1024
1025                         ftpResponse.WelcomeMessage = status.StatusDescription;
1026                         ftpResponse.UpdateStatus (status);
1027                 }
1028
1029                 FtpStatus SendCommand (string command, params string [] parameters) {
1030                         return SendCommand (true, command, parameters);
1031                 }
1032
1033                 FtpStatus SendCommand (bool waitResponse, string command, params string [] parameters)
1034                 {
1035                         byte [] cmd;
1036                         string commandString = command;
1037                         if (parameters.Length > 0)
1038                                 commandString += " " + String.Join (" ", parameters);
1039
1040                         commandString += EOL;
1041                         cmd = Encoding.ASCII.GetBytes (commandString);
1042                         try {
1043                                 controlStream.Write (cmd, 0, cmd.Length);
1044                         } catch (IOException) {
1045                                 //controlStream.Close ();
1046                                 return new FtpStatus(FtpStatusCode.ServiceNotAvailable, "Write failed");
1047                         }
1048
1049                         if(!waitResponse)
1050                                 return null;
1051
1052                         FtpStatus result = GetResponseStatus ();
1053                         if (ftpResponse != null)
1054                                 ftpResponse.UpdateStatus (result);
1055                         return result;
1056                 }
1057
1058                 internal static FtpStatus ServiceNotAvailable ()
1059                 {
1060                         return new FtpStatus (FtpStatusCode.ServiceNotAvailable, Locale.GetText ("Invalid response from server"));
1061                 }
1062
1063                 internal FtpStatus GetResponseStatus ()
1064                 {
1065                         while (true) {
1066                                 string response = null;
1067
1068                                 try {
1069                                         response = controlReader.ReadLine ();
1070                                 } catch (IOException) {
1071                                 }
1072
1073                                 if (response == null || response.Length < 3)
1074                                         return ServiceNotAvailable ();
1075
1076                                 int code;
1077                                 if (!Int32.TryParse (response.Substring (0, 3), out code))
1078                                         return ServiceNotAvailable ();
1079
1080                                 if (response [3] == '-'){
1081                                         string line = null;
1082                                         string find = code.ToString() + ' ';
1083                                         while (true){
1084                                                 try {
1085                                                         line = controlReader.ReadLine();
1086                                                 } catch (IOException) {
1087                                                 }
1088                                                 if (line == null)
1089                                                         return ServiceNotAvailable ();
1090
1091                                                 response += Environment.NewLine + line;
1092
1093                                                 if (line.StartsWith(find, StringComparison.Ordinal))
1094                                                         break;
1095                                         }
1096                                 }
1097                                 return new FtpStatus ((FtpStatusCode) code, response);
1098                         }
1099                 }
1100
1101                 private void InitiateSecureConnection (ref NetworkStream stream) {
1102                         FtpStatus status = SendCommand (AuthCommand, "TLS");
1103
1104                         if (status.StatusCode != FtpStatusCode.ServerWantsSecureSession) {
1105                                 throw CreateExceptionFromResponse (status);
1106                         }
1107
1108                         ChangeToSSLSocket (ref stream);
1109                 }
1110
1111                 internal static bool ChangeToSSLSocket (ref NetworkStream stream) {
1112 #if TARGET_JVM
1113                         stream.ChangeToSSLSocket ();
1114                         return true;
1115 #else
1116                         throw new NotImplementedException ();
1117 #endif
1118                 }
1119
1120                 bool InFinalState () {
1121                         return (State == RequestState.Aborted || State == RequestState.Error || State == RequestState.Finished);
1122                 }
1123
1124                 bool InProgress () {
1125                         return (State != RequestState.Before && !InFinalState ());
1126                 }
1127
1128                 internal void CheckIfAborted () {
1129                         if (State == RequestState.Aborted)
1130                                 throw new WebException ("Request aborted", WebExceptionStatus.RequestCanceled);
1131                 }
1132
1133                 void CheckFinalState () {
1134                         if (InFinalState ())
1135                                 throw new InvalidOperationException ("Cannot change final state");
1136                 }
1137
1138                 class EmptyStream : MemoryStream
1139                 {
1140                         internal EmptyStream ()
1141                                 : base (new byte [0], false) {
1142                         }
1143                 }
1144         }
1145 }
1146
1147 #endif
1148