mcs/class/System/System.Net/WebConnectionStream.cs

   1 //
   2 // System.Net.WebConnectionStream
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2003 Ximian, Inc (http://www.ximian.com)
   8 // (C) 2004 Novell, Inc (http://www.novell.com)
   9 //
  10
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.IO;
  33 using System.Text;
  34 using System.Threading;
  35
  36 namespace System.Net
  37 {
  38         class WebConnectionStream : Stream
  39         {
  40                 static byte [] crlf = new byte [] { 13, 10 };
  41                 bool isRead;
  42                 WebConnection cnc;
  43                 HttpWebRequest request;
  44                 byte [] readBuffer;
  45                 int readBufferOffset;
  46                 int readBufferSize;
  47                 int contentLength;
  48                 int totalRead;
  49                 internal long totalWritten;
  50                 bool nextReadCalled;
  51                 int pendingReads;
  52                 int pendingWrites;
  53                 ManualResetEvent pending;
  54                 bool allowBuffering;
  55                 bool sendChunked;
  56                 MemoryStream writeBuffer;
  57                 bool requestWritten;
  58                 byte [] headers;
  59                 bool disposed;
  60                 bool headersSent;
  61                 object locker = new object ();
  62                 bool initRead;
  63                 bool read_eof;
  64                 bool complete_request_written;
  65                 int read_timeout;
  66                 int write_timeout;
  67                 AsyncCallback cb_wrapper; // Calls to ReadCallbackWrapper or WriteCallbacWrapper
  68                 internal bool IgnoreIOErrors;
  69
  70                 public WebConnectionStream (WebConnection cnc)
  71                 {
  72                         isRead = true;
  73                         cb_wrapper = new AsyncCallback (ReadCallbackWrapper);
  74                         pending = new ManualResetEvent (true);
  75                         this.request = cnc.Data.request;
  76                         read_timeout = request.ReadWriteTimeout;
  77                         write_timeout = read_timeout;
  78                         this.cnc = cnc;
  79                         string contentType = cnc.Data.Headers ["Transfer-Encoding"];
  80                         bool chunkedRead = (contentType != null && contentType.IndexOf ("chunked", StringComparison.OrdinalIgnoreCase) != -1);
  81                         string clength = cnc.Data.Headers ["Content-Length"];
  82                         if (!chunkedRead && clength != null && clength != "") {
  83                                 try {
  84                                         contentLength = Int32.Parse (clength);
  85                                         if (contentLength == 0 && !IsNtlmAuth ()) {
  86                                                 ReadAll ();
  87                                         }
  88                                 } catch {
  89                                         contentLength = Int32.MaxValue;
  90                                 }
  91                         } else {
  92                                 contentLength = Int32.MaxValue;
  93                         }
  94                 }
  95
  96                 public WebConnectionStream (WebConnection cnc, HttpWebRequest request)
  97                 {
  98                         read_timeout = request.ReadWriteTimeout;
  99                         write_timeout = read_timeout;
 100                         isRead = false;
 101                         cb_wrapper = new AsyncCallback (WriteCallbackWrapper);
 102                         this.cnc = cnc;
 103                         this.request = request;
 104                         allowBuffering = request.InternalAllowBuffering;
 105                         sendChunked = request.SendChunked;
 106                         if (sendChunked)
 107                                 pending = new ManualResetEvent (true);
 108                         else if (allowBuffering)
 109                                 writeBuffer = new MemoryStream ();
 110                 }
 111
 112                 bool IsNtlmAuth ()
 113                 {
 114                         bool isProxy = (request.Proxy != null && !request.Proxy.IsBypassed (request.Address));
 115                         string header_name = (isProxy) ? "Proxy-Authenticate" : "WWW-Authenticate";
 116                         string authHeader = cnc.Data.Headers [header_name];
 117                         return (authHeader != null && authHeader.IndexOf ("NTLM", StringComparison.Ordinal) != -1);
 118                 }
 119
 120                 internal void CheckResponseInBuffer ()
 121                 {
 122                         if (contentLength > 0 && (readBufferSize - readBufferOffset) >= contentLength) {
 123                                 if (!IsNtlmAuth ())
 124                                         ReadAll ();
 125                         }
 126                 }
 127
 128                 internal HttpWebRequest Request {
 129                         get { return request; }
 130                 }
 131
 132                 internal WebConnection Connection {
 133                         get { return cnc; }
 134                 }
 135 #if NET_2_0
 136                 public override bool CanTimeout {
 137                         get { return true; }
 138                 }
 139 #endif
 140
 141 #if NET_2_0
 142                 public override
 143 #endif
 144                 int ReadTimeout {
 145                         get {
 146                                 return read_timeout;
 147                         }
 148
 149                         set {
 150                                 if (value < -1)
 151                                         throw new ArgumentOutOfRangeException ("value");
 152                                 read_timeout = value;
 153                         }
 154                 }
 155
 156 #if NET_2_0
 157                 public override
 158 #endif
 159                 int WriteTimeout {
 160                         get {
 161                                 return write_timeout;
 162                         }
 163
 164                         set {
 165                                 if (value < -1)
 166                                         throw new ArgumentOutOfRangeException ("value");
 167                                 write_timeout = value;
 168                         }
 169                 }
 170
 171                 internal bool CompleteRequestWritten {
 172                         get { return complete_request_written; }
 173                 }
 174
 175                 internal bool SendChunked {
 176                         set { sendChunked = value; }
 177                 }
 178
 179                 internal byte [] ReadBuffer {
 180                         set { readBuffer = value; }
 181                 }
 182
 183                 internal int ReadBufferOffset {
 184                         set { readBufferOffset = value;}
 185                 }
 186
 187                 internal int ReadBufferSize {
 188                         set { readBufferSize = value; }
 189                 }
 190
 191                 internal byte[] WriteBuffer {
 192                         get { return writeBuffer.GetBuffer (); }
 193                 }
 194
 195                 internal int WriteBufferLength {
 196                         get { return writeBuffer != null ? (int) writeBuffer.Length : (-1); }
 197                 }
 198
 199                 internal void ForceCompletion ()
 200                 {
 201                         if (!nextReadCalled) {
 202                                 if (contentLength == Int32.MaxValue)
 203                                         contentLength = 0;
 204                                 nextReadCalled = true;
 205                                 cnc.NextRead ();
 206                         }
 207                 }
 208
 209                 internal void CheckComplete ()
 210                 {
 211                         bool nrc = nextReadCalled;
 212                         if (!nrc && readBufferSize - readBufferOffset == contentLength) {
 213                                 nextReadCalled = true;
 214                                 cnc.NextRead ();
 215                         }
 216                 }
 217
 218                 internal void ReadAll ()
 219                 {
 220                         if (!isRead || read_eof || totalRead >= contentLength || nextReadCalled) {
 221                                 if (isRead && !nextReadCalled) {
 222                                         nextReadCalled = true;
 223                                         cnc.NextRead ();
 224                                 }
 225                                 return;
 226                         }
 227
 228                         pending.WaitOne ();
 229                         lock (locker) {
 230                                 if (totalRead >= contentLength)
 231                                         return;
 232
 233                                 byte [] b = null;
 234                                 int diff = readBufferSize - readBufferOffset;
 235                                 int new_size;
 236
 237                                 if (contentLength == Int32.MaxValue) {
 238                                         MemoryStream ms = new MemoryStream ();
 239                                         byte [] buffer = null;
 240                                         if (readBuffer != null && diff > 0) {
 241                                                 ms.Write (readBuffer, readBufferOffset, diff);
 242                                                 if (readBufferSize >= 8192)
 243                                                         buffer = readBuffer;
 244                                         }
 245
 246                                         if (buffer == null)
 247                                                 buffer = new byte [8192];
 248
 249                                         int read;
 250                                         while ((read = cnc.Read (request, buffer, 0, buffer.Length)) != 0)
 251                                                 ms.Write (buffer, 0, read);
 252
 253                                         b = ms.GetBuffer ();
 254                                         new_size = (int) ms.Length;
 255                                         contentLength = new_size;
 256                                 } else {
 257                                         new_size = contentLength - totalRead;
 258                                         b = new byte [new_size];
 259                                         if (readBuffer != null && diff > 0) {
 260                                                 if (diff > new_size)
 261                                                         diff = new_size;
 262
 263                                                 Buffer.BlockCopy (readBuffer, readBufferOffset, b, 0, diff);
 264                                         }
 265
 266                                         int remaining = new_size - diff;
 267                                         int r = -1;
 268                                         while (remaining > 0 && r != 0) {
 269                                                 r = cnc.Read (request, b, diff, remaining);
 270                                                 remaining -= r;
 271                                                 diff += r;
 272                                         }
 273                                 }
 274
 275                                 readBuffer = b;
 276                                 readBufferOffset = 0;
 277                                 readBufferSize = new_size;
 278                                 totalRead = 0;
 279                                 nextReadCalled = true;
 280                         }
 281
 282                         cnc.NextRead ();
 283                 }
 284
 285                 void WriteCallbackWrapper (IAsyncResult r)
 286                 {
 287                         WebAsyncResult result = r as WebAsyncResult;
 288                         if (result != null && result.AsyncWriteAll)
 289                                 return;
 290
 291                         if (r.AsyncState != null) {
 292                                 result = (WebAsyncResult) r.AsyncState;
 293                                 result.InnerAsyncResult = r;
 294                                 result.DoCallback ();
 295                         } else {
 296                                 try {
 297                                         EndWrite (r);
 298                                 } catch {
 299                                 }
 300                         }
 301                 }
 302
 303                 void ReadCallbackWrapper (IAsyncResult r)
 304                 {
 305                         WebAsyncResult result;
 306                         if (r.AsyncState != null) {
 307                                 result = (WebAsyncResult) r.AsyncState;
 308                                 result.InnerAsyncResult = r;
 309                                 result.DoCallback ();
 310                         } else {
 311                                 try {
 312                                         EndRead (r);
 313                                 } catch {
 314                                 }
 315                         }
 316                 }
 317
 318                 public override int Read (byte [] buffer, int offset, int size)
 319                 {
 320                         AsyncCallback cb = cb_wrapper;
 321                         WebAsyncResult res = (WebAsyncResult) BeginRead (buffer, offset, size, cb, null);
 322                         if (!res.IsCompleted && !res.WaitUntilComplete (ReadTimeout, false)) {
 323                                 nextReadCalled = true;
 324                                 cnc.Close (true);
 325                                 throw new WebException ("The operation has timed out.", WebExceptionStatus.Timeout);
 326                         }
 327
 328                         return EndRead (res);
 329                 }
 330
 331                 public override IAsyncResult BeginRead (byte [] buffer, int offset, int size,
 332                                                         AsyncCallback cb, object state)
 333                 {
 334                         if (!isRead)
 335                                 throw new NotSupportedException ("this stream does not allow reading");
 336
 337                         if (buffer == null)
 338                                 throw new ArgumentNullException ("buffer");
 339
 340                         int length = buffer.Length;
 341                         if (offset < 0 || length < offset)
 342                                 throw new ArgumentOutOfRangeException ("offset");
 343                         if (size < 0 || (length - offset) < size)
 344                                 throw new ArgumentOutOfRangeException ("size");
 345
 346                         lock (locker) {
 347                                 pendingReads++;
 348                                 pending.Reset ();
 349                         }
 350
 351                         WebAsyncResult result = new WebAsyncResult (cb, state, buffer, offset, size);
 352                         if (totalRead >= contentLength) {
 353                                 result.SetCompleted (true, -1);
 354                                 result.DoCallback ();
 355                                 return result;
 356                         }
 357
 358                         int remaining = readBufferSize - readBufferOffset;
 359                         if (remaining > 0) {
 360                                 int copy = (remaining > size) ? size : remaining;
 361                                 Buffer.BlockCopy (readBuffer, readBufferOffset, buffer, offset, copy);
 362                                 readBufferOffset += copy;
 363                                 offset += copy;
 364                                 size -= copy;
 365                                 totalRead += copy;
 366                                 if (size == 0 || totalRead >= contentLength) {
 367                                         result.SetCompleted (true, copy);
 368                                         result.DoCallback ();
 369                                         return result;
 370                                 }
 371                                 result.NBytes = copy;
 372                         }
 373
 374                         if (cb != null)
 375                                 cb = cb_wrapper;
 376
 377                         if (contentLength != Int32.MaxValue && contentLength - totalRead < size)
 378                                 size = contentLength - totalRead;
 379
 380                         if (!read_eof) {
 381                                 result.InnerAsyncResult = cnc.BeginRead (request, buffer, offset, size, cb, result);
 382                         } else {
 383                                 result.SetCompleted (true, result.NBytes);
 384                                 result.DoCallback ();
 385                         }
 386                         return result;
 387                 }
 388
 389                 public override int EndRead (IAsyncResult r)
 390                 {
 391                         WebAsyncResult result = (WebAsyncResult) r;
 392                         if (result.EndCalled) {
 393                                 int xx = result.NBytes;
 394                                 return (xx >= 0) ? xx : 0;
 395                         }
 396
 397                         result.EndCalled = true;
 398
 399                         if (!result.IsCompleted) {
 400                                 int nbytes = -1;
 401                                 try {
 402                                         nbytes = cnc.EndRead (request, result);
 403                                 } catch (Exception exc) {
 404                                         lock (locker) {
 405                                                 pendingReads--;
 406                                                 if (pendingReads == 0)
 407                                                         pending.Set ();
 408                                         }
 409
 410                                         nextReadCalled = true;
 411                                         cnc.Close (true);
 412                                         result.SetCompleted (false, exc);
 413                                         result.DoCallback ();
 414                                         throw;
 415                                 }
 416
 417                                 if (nbytes < 0) {
 418                                         nbytes = 0;
 419                                         read_eof = true;
 420                                 }
 421
 422                                 totalRead += nbytes;
 423                                 result.SetCompleted (false, nbytes + result.NBytes);
 424                                 result.DoCallback ();
 425                                 if (nbytes == 0)
 426                                         contentLength = totalRead;
 427                         }
 428
 429                         lock (locker) {
 430                                 pendingReads--;
 431                                 if (pendingReads == 0)
 432                                         pending.Set ();
 433                         }
 434
 435                         if (totalRead >= contentLength && !nextReadCalled)
 436                                 ReadAll ();
 437
 438                         int nb = result.NBytes;
 439                         return (nb >= 0) ? nb : 0;
 440                 }
 441
 442                 void WriteRequestAsyncCB (IAsyncResult r)
 443                 {
 444                         WebAsyncResult result = (WebAsyncResult) r.AsyncState;
 445                         try {
 446                                 cnc.EndWrite2 (request, r);
 447                                 result.SetCompleted (false, 0);
 448                                 if (!initRead) {
 449                                         initRead = true;
 450                                         WebConnection.InitRead (cnc);
 451                                 }
 452                         } catch (Exception e) {
 453                                 KillBuffer ();
 454                                 nextReadCalled = true;
 455                                 cnc.Close (true);
 456                                 if (e is System.Net.Sockets.SocketException)
 457                                         e = new IOException ("Error writing request", e);
 458                                 result.SetCompleted (false, e);
 459                         }
 460                         complete_request_written = true;
 461                         result.DoCallback ();
 462                 }
 463
 464                 public override IAsyncResult BeginWrite (byte [] buffer, int offset, int size,
 465                                                         AsyncCallback cb, object state)
 466                 {
 467                         if (request.Aborted)
 468                                 throw new WebException ("The request was canceled.", null, WebExceptionStatus.RequestCanceled);
 469
 470                         if (isRead)
 471                                 throw new NotSupportedException ("this stream does not allow writing");
 472
 473                         if (buffer == null)
 474                                 throw new ArgumentNullException ("buffer");
 475
 476                         int length = buffer.Length;
 477                         if (offset < 0 || length < offset)
 478                                 throw new ArgumentOutOfRangeException ("offset");
 479                         if (size < 0 || (length - offset) < size)
 480                                 throw new ArgumentOutOfRangeException ("size");
 481
 482                         if (sendChunked) {
 483                                 lock (locker) {
 484                                         pendingWrites++;
 485                                         pending.Reset ();
 486                                 }
 487                         }
 488
 489                         WebAsyncResult result = new WebAsyncResult (cb, state);
 490                         if (!sendChunked)
 491                                 CheckWriteOverflow (request.ContentLength, totalWritten, size);
 492                         if (allowBuffering && !sendChunked) {
 493                                 if (writeBuffer == null)
 494                                         writeBuffer = new MemoryStream ();
 495                                 writeBuffer.Write (buffer, offset, size);
 496                                 totalWritten += size;
 497                                 if (request.ContentLength > 0 && totalWritten == request.ContentLength) {
 498                                         try {
 499                                                 result.AsyncWriteAll = true;
 500                                                 result.InnerAsyncResult = WriteRequestAsync (new AsyncCallback (WriteRequestAsyncCB), result);
 501                                                 if (result.InnerAsyncResult == null) {
 502                                                         if (!result.IsCompleted)
 503                                                                 result.SetCompleted (true, 0);
 504                                                         result.DoCallback ();
 505                                                 }
 506                                         } catch (Exception exc) {
 507                                                 result.SetCompleted (true, exc);
 508                                                 result.DoCallback ();
 509                                         }
 510                                 } else {
 511                                         result.SetCompleted (true, 0);
 512                                         result.DoCallback ();
 513                                 }
 514                                 return result;
 515                         }
 516
 517                         AsyncCallback callback = null;
 518                         if (cb != null)
 519                                 callback = cb_wrapper;
 520
 521                         if (sendChunked) {
 522                                 WriteRequest ();
 523
 524                                 string cSize = String.Format ("{0:X}\r\n", size);
 525                                 byte [] head = Encoding.ASCII.GetBytes (cSize);
 526                                 int chunkSize = 2 + size + head.Length;
 527                                 byte [] newBuffer = new byte [chunkSize];
 528                                 Buffer.BlockCopy (head, 0, newBuffer, 0, head.Length);
 529                                 Buffer.BlockCopy (buffer, offset, newBuffer, head.Length, size);
 530                                 Buffer.BlockCopy (crlf, 0, newBuffer, head.Length + size, crlf.Length);
 531
 532                                 buffer = newBuffer;
 533                                 offset = 0;
 534                                 size = chunkSize;
 535                         }
 536
 537                         try {
 538                                 result.InnerAsyncResult = cnc.BeginWrite (request, buffer, offset, size, callback, result);
 539                         } catch (Exception) {
 540                                 if (!IgnoreIOErrors)
 541                                         throw;
 542                                 result.SetCompleted (true, 0);
 543                                 result.DoCallback ();
 544                         }
 545                         totalWritten += size;
 546                         return result;
 547                 }
 548
 549                 void CheckWriteOverflow (long contentLength, long totalWritten, long size)
 550                 {
 551                         if (contentLength == -1)
 552                                 return;
 553
 554                         long avail = contentLength - totalWritten;
 555                         if (size > avail) {
 556                                 KillBuffer ();
 557                                 nextReadCalled = true;
 558                                 cnc.Close (true);
 559                                 throw new ProtocolViolationException (
 560                                         "The number of bytes to be written is greater than " +
 561                                         "the specified ContentLength.");
 562                         }
 563                 }
 564
 565                 public override void EndWrite (IAsyncResult r)
 566                 {
 567                         if (r == null)
 568                                 throw new ArgumentNullException ("r");
 569
 570                         WebAsyncResult result = r as WebAsyncResult;
 571                         if (result == null)
 572                                 throw new ArgumentException ("Invalid IAsyncResult");
 573
 574                         if (result.EndCalled)
 575                                 return;
 576
 577                         result.EndCalled = true;
 578                         if (result.AsyncWriteAll) {
 579                                 result.WaitUntilComplete ();
 580                                 if (result.GotException)
 581                                         throw result.Exception;
 582                                 return;
 583                         }
 584
 585                         if (allowBuffering && !sendChunked)
 586                                 return;
 587
 588                         if (result.GotException)
 589                                 throw result.Exception;
 590
 591                         try {
 592                                 cnc.EndWrite2 (request, result.InnerAsyncResult);
 593                                 result.SetCompleted (false, 0);
 594                                 result.DoCallback ();
 595                         } catch (Exception e) {
 596                                 if (IgnoreIOErrors)
 597                                         result.SetCompleted (false, 0);
 598                                 else
 599                                         result.SetCompleted (false, e);
 600                                 result.DoCallback ();
 601                                 if (!IgnoreIOErrors)
 602                                         throw;
 603                         } finally {
 604                                 if (sendChunked) {
 605                                         lock (locker) {
 606                                                 pendingWrites--;
 607                                                 if (pendingWrites == 0)
 608                                                         pending.Set ();
 609                                         }
 610                                 }
 611                         }
 612                 }
 613
 614                 public override void Write (byte [] buffer, int offset, int size)
 615                 {
 616                         AsyncCallback cb = cb_wrapper;
 617                         WebAsyncResult res = (WebAsyncResult) BeginWrite (buffer, offset, size, cb, null);
 618                         if (!res.IsCompleted && !res.WaitUntilComplete (WriteTimeout, false)) {
 619                                 KillBuffer ();
 620                                 nextReadCalled = true;
 621                                 cnc.Close (true);
 622                                 throw new IOException ("Write timed out.");
 623                         }
 624
 625                         EndWrite (res);
 626                 }
 627
 628                 public override void Flush ()
 629                 {
 630                 }
 631
 632                 internal void SetHeaders (byte [] buffer)
 633                 {
 634                         if (headersSent)
 635                                 return;
 636
 637                         headers = buffer;
 638                         long cl = request.ContentLength;
 639                         string method = request.Method;
 640                         bool no_writestream = (method == "GET" || method == "CONNECT" || method == "HEAD" ||
 641                                                 method == "TRACE" || method == "DELETE");
 642                         if (sendChunked || cl > -1 || no_writestream) {
 643                                 WriteHeaders ();
 644                                 if (!initRead) {
 645                                         initRead = true;
 646                                         WebConnection.InitRead (cnc);
 647                                 }
 648                                 if (!sendChunked && cl == 0)
 649                                         requestWritten = true;
 650                         }
 651                 }
 652
 653                 internal bool RequestWritten {
 654                         get { return requestWritten; }
 655                 }
 656
 657                 IAsyncResult WriteRequestAsync (AsyncCallback cb, object state)
 658                 {
 659                         requestWritten = true;
 660                         byte [] bytes = writeBuffer.GetBuffer ();
 661                         int length = (int) writeBuffer.Length;
 662                         // Headers already written to the stream
 663                         return (length > 0) ? cnc.BeginWrite (request, bytes, 0, length, cb, state) : null;
 664                 }
 665
 666                 void WriteHeaders ()
 667                 {
 668                         if (headersSent)
 669                                 return;
 670
 671                         headersSent = true;
 672                         string err_msg = null;
 673                         if (!cnc.Write (request, headers, 0, headers.Length, ref err_msg))
 674                                 throw new WebException ("Error writing request: " + err_msg, null, WebExceptionStatus.SendFailure, null);
 675                 }
 676
 677                 internal void WriteRequest ()
 678                 {
 679                         if (requestWritten)
 680                                 return;
 681
 682                         requestWritten = true;
 683                         if (sendChunked)
 684                                 return;
 685
 686                         if (!allowBuffering || writeBuffer == null)
 687                                 return;
 688
 689                         byte [] bytes = writeBuffer.GetBuffer ();
 690                         int length = (int) writeBuffer.Length;
 691                         if (request.ContentLength != -1 && request.ContentLength < length) {
 692                                 nextReadCalled = true;
 693                                 cnc.Close (true);
 694                                 throw new WebException ("Specified Content-Length is less than the number of bytes to write", null,
 695                                                         WebExceptionStatus.ServerProtocolViolation, null);
 696                         }
 697
 698                         if (!headersSent) {
 699                                 string method = request.Method;
 700                                 bool no_writestream = (method == "GET" || method == "CONNECT" || method == "HEAD" ||
 701                                                         method == "TRACE" || method == "DELETE");
 702                                 if (!no_writestream)
 703                                         request.InternalContentLength = length;
 704                                 request.SendRequestHeaders (true);
 705                         }
 706                         WriteHeaders ();
 707                         if (cnc.Data.StatusCode != 0 && cnc.Data.StatusCode != 100)
 708                                 return;
 709
 710                         IAsyncResult result = null;
 711                         if (length > 0)
 712                                 result = cnc.BeginWrite (request, bytes, 0, length, null, null);
 713
 714                         if (!initRead) {
 715                                 initRead = true;
 716                                 WebConnection.InitRead (cnc);
 717                         }
 718
 719                         if (length > 0)
 720                                 complete_request_written = cnc.EndWrite (request, result);
 721                         else
 722                                 complete_request_written = true;
 723                 }
 724
 725                 internal void InternalClose ()
 726                 {
 727                         disposed = true;
 728                 }
 729
 730                 public override void Close ()
 731                 {
 732                         if (sendChunked) {
 733                                 if (disposed)
 734                                         return;
 735                                 disposed = true;
 736                                 pending.WaitOne ();
 737                                 byte [] chunk = Encoding.ASCII.GetBytes ("0\r\n\r\n");
 738                                 string err_msg = null;
 739                                 cnc.Write (request, chunk, 0, chunk.Length, ref err_msg);
 740                                 return;
 741                         }
 742
 743                         if (isRead) {
 744                                 if (!nextReadCalled) {
 745                                         CheckComplete ();
 746                                         // If we have not read all the contents
 747                                         if (!nextReadCalled) {
 748                                                 nextReadCalled = true;
 749                                                 cnc.Close (true);
 750                                         }
 751                                 }
 752                                 return;
 753                         } else if (!allowBuffering) {
 754                                 complete_request_written = true;
 755                                 if (!initRead) {
 756                                         initRead = true;
 757                                         WebConnection.InitRead (cnc);
 758                                 }
 759                                 return;
 760                         }
 761
 762                         if (disposed || requestWritten)
 763                                 return;
 764
 765                         long length = request.ContentLength;
 766
 767                         if (!sendChunked && length != -1 && totalWritten != length) {
 768                                 IOException io = new IOException ("Cannot close the stream until all bytes are written");
 769                                 nextReadCalled = true;
 770                                 cnc.Close (true);
 771                                 throw new WebException ("Request was cancelled.", io, WebExceptionStatus.RequestCanceled);
 772                         }
 773
 774                         WriteRequest ();
 775                         disposed = true;
 776                 }
 777
 778                 internal void KillBuffer ()
 779                 {
 780                         writeBuffer = null;
 781                 }
 782
 783                 public override long Seek (long a, SeekOrigin b)
 784                 {
 785                         throw new NotSupportedException ();
 786                 }
 787
 788                 public override void SetLength (long a)
 789                 {
 790                         throw new NotSupportedException ();
 791                 }
 792
 793                 public override bool CanSeek {
 794                         get { return false; }
 795                 }
 796
 797                 public override bool CanRead {
 798                         get { return !disposed && isRead; }
 799                 }
 800
 801                 public override bool CanWrite {
 802                         get { return !disposed && !isRead; }
 803                 }
 804
 805                 public override long Length {
 806                         get { throw new NotSupportedException (); }
 807                 }
 808
 809                 public override long Position {
 810                         get { throw new NotSupportedException (); }
 811                         set { throw new NotSupportedException (); }
 812                 }
 813         }
 814 }
 815