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 stream_length; // -1 when CL not present
  48                 int contentLength;
  49                 int totalRead;
  50                 internal long totalWritten;
  51                 bool nextReadCalled;
  52                 int pendingReads;
  53                 int pendingWrites;
  54                 ManualResetEvent pending;
  55                 bool allowBuffering;
  56                 bool sendChunked;
  57                 MemoryStream writeBuffer;
  58                 bool requestWritten;
  59                 byte [] headers;
  60                 bool disposed;
  61                 bool headersSent;
  62                 object locker = new object ();
  63                 bool initRead;
  64                 bool read_eof;
  65                 bool complete_request_written;
  66                 int read_timeout;
  67                 int write_timeout;
  68                 AsyncCallback cb_wrapper; // Calls to ReadCallbackWrapper or WriteCallbacWrapper
  69                 internal bool IgnoreIOErrors;
  70
  71                 public WebConnectionStream (WebConnection cnc)
  72                 {
  73                         isRead = true;
  74                         cb_wrapper = new AsyncCallback (ReadCallbackWrapper);
  75                         pending = new ManualResetEvent (true);
  76                         this.request = cnc.Data.request;
  77                         read_timeout = request.ReadWriteTimeout;
  78                         write_timeout = read_timeout;
  79                         this.cnc = cnc;
  80                         string contentType = cnc.Data.Headers ["Transfer-Encoding"];
  81                         bool chunkedRead = (contentType != null && contentType.IndexOf ("chunked", StringComparison.OrdinalIgnoreCase) != -1);
  82                         string clength = cnc.Data.Headers ["Content-Length"];
  83                         if (!chunkedRead && clength != null && clength != "") {
  84                                 try {
  85                                         contentLength = Int32.Parse (clength);
  86                                         if (contentLength == 0 && !IsNtlmAuth ()) {
  87                                                 ReadAll ();
  88                                         }
  89                                 } catch {
  90                                         contentLength = Int32.MaxValue;
  91                                 }
  92                         } else {
  93                                 contentLength = Int32.MaxValue;
  94                         }
  95
  96                         // Negative numbers?
  97                         if (!Int32.TryParse (clength, out stream_length))
  98                                 stream_length = -1;
  99                 }
 100
 101                 public WebConnectionStream (WebConnection cnc, HttpWebRequest request)
 102                 {
 103                         read_timeout = request.ReadWriteTimeout;
 104                         write_timeout = read_timeout;
 105                         isRead = false;
 106                         cb_wrapper = new AsyncCallback (WriteCallbackWrapper);
 107                         this.cnc = cnc;
 108                         this.request = request;
 109                         allowBuffering = request.InternalAllowBuffering;
 110                         sendChunked = request.SendChunked;
 111                         if (sendChunked)
 112                                 pending = new ManualResetEvent (true);
 113                         else if (allowBuffering)
 114                                 writeBuffer = new MemoryStream ();
 115                 }
 116
 117                 bool IsNtlmAuth ()
 118                 {
 119                         bool isProxy = (request.Proxy != null && !request.Proxy.IsBypassed (request.Address));
 120                         string header_name = (isProxy) ? "Proxy-Authenticate" : "WWW-Authenticate";
 121                         string authHeader = cnc.Data.Headers [header_name];
 122                         return (authHeader != null && authHeader.IndexOf ("NTLM", StringComparison.Ordinal) != -1);
 123                 }
 124
 125                 internal void CheckResponseInBuffer ()
 126                 {
 127                         if (contentLength > 0 && (readBufferSize - readBufferOffset) >= contentLength) {
 128                                 if (!IsNtlmAuth ())
 129                                         ReadAll ();
 130                         }
 131                 }
 132
 133                 internal HttpWebRequest Request {
 134                         get { return request; }
 135                 }
 136
 137                 internal WebConnection Connection {
 138                         get { return cnc; }
 139                 }
 140 #if NET_2_0
 141                 public override bool CanTimeout {
 142                         get { return true; }
 143                 }
 144 #endif
 145
 146 #if NET_2_0
 147                 public override
 148 #endif
 149                 int ReadTimeout {
 150                         get {
 151                                 return read_timeout;
 152                         }
 153
 154                         set {
 155                                 if (value < -1)
 156                                         throw new ArgumentOutOfRangeException ("value");
 157                                 read_timeout = value;
 158                         }
 159                 }
 160
 161 #if NET_2_0
 162                 public override
 163 #endif
 164                 int WriteTimeout {
 165                         get {
 166                                 return write_timeout;
 167                         }
 168
 169                         set {
 170                                 if (value < -1)
 171                                         throw new ArgumentOutOfRangeException ("value");
 172                                 write_timeout = value;
 173                         }
 174                 }
 175
 176                 internal bool CompleteRequestWritten {
 177                         get { return complete_request_written; }
 178                 }
 179
 180                 internal bool SendChunked {
 181                         set { sendChunked = value; }
 182                 }
 183
 184                 internal byte [] ReadBuffer {
 185                         set { readBuffer = value; }
 186                 }
 187
 188                 internal int ReadBufferOffset {
 189                         set { readBufferOffset = value;}
 190                 }
 191
 192                 internal int ReadBufferSize {
 193                         set { readBufferSize = value; }
 194                 }
 195
 196                 internal byte[] WriteBuffer {
 197                         get { return writeBuffer.GetBuffer (); }
 198                 }
 199
 200                 internal int WriteBufferLength {
 201                         get { return writeBuffer != null ? (int) writeBuffer.Length : (-1); }
 202                 }
 203
 204                 internal void ForceCompletion ()
 205                 {
 206                         if (!nextReadCalled) {
 207                                 if (contentLength == Int32.MaxValue)
 208                                         contentLength = 0;
 209                                 nextReadCalled = true;
 210                                 cnc.NextRead ();
 211                         }
 212                 }
 213
 214                 internal void CheckComplete ()
 215                 {
 216                         bool nrc = nextReadCalled;
 217                         if (!nrc && readBufferSize - readBufferOffset == contentLength) {
 218                                 nextReadCalled = true;
 219                                 cnc.NextRead ();
 220                         }
 221                 }
 222
 223                 internal void ReadAll ()
 224                 {
 225                         if (!isRead || read_eof || totalRead >= contentLength || nextReadCalled) {
 226                                 if (isRead && !nextReadCalled) {
 227                                         nextReadCalled = true;
 228                                         cnc.NextRead ();
 229                                 }
 230                                 return;
 231                         }
 232
 233                         pending.WaitOne ();
 234                         lock (locker) {
 235                                 if (totalRead >= contentLength)
 236                                         return;
 237
 238                                 byte [] b = null;
 239                                 int diff = readBufferSize - readBufferOffset;
 240                                 int new_size;
 241
 242                                 if (contentLength == Int32.MaxValue) {
 243                                         MemoryStream ms = new MemoryStream ();
 244                                         byte [] buffer = null;
 245                                         if (readBuffer != null && diff > 0) {
 246                                                 ms.Write (readBuffer, readBufferOffset, diff);
 247                                                 if (readBufferSize >= 8192)
 248                                                         buffer = readBuffer;
 249                                         }
 250
 251                                         if (buffer == null)
 252                                                 buffer = new byte [8192];
 253
 254                                         int read;
 255                                         while ((read = cnc.Read (request, buffer, 0, buffer.Length)) != 0)
 256                                                 ms.Write (buffer, 0, read);
 257
 258                                         b = ms.GetBuffer ();
 259                                         new_size = (int) ms.Length;
 260                                         contentLength = new_size;
 261                                 } else {
 262                                         new_size = contentLength - totalRead;
 263                                         b = new byte [new_size];
 264                                         if (readBuffer != null && diff > 0) {
 265                                                 if (diff > new_size)
 266                                                         diff = new_size;
 267
 268                                                 Buffer.BlockCopy (readBuffer, readBufferOffset, b, 0, diff);
 269                                         }
 270
 271                                         int remaining = new_size - diff;
 272                                         int r = -1;
 273                                         while (remaining > 0 && r != 0) {
 274                                                 r = cnc.Read (request, b, diff, remaining);
 275                                                 remaining -= r;
 276                                                 diff += r;
 277                                         }
 278                                 }
 279
 280                                 readBuffer = b;
 281                                 readBufferOffset = 0;
 282                                 readBufferSize = new_size;
 283                                 totalRead = 0;
 284                                 nextReadCalled = true;
 285                         }
 286
 287                         cnc.NextRead ();
 288                 }
 289
 290                 void WriteCallbackWrapper (IAsyncResult r)
 291                 {
 292                         WebAsyncResult result = r as WebAsyncResult;
 293                         if (result != null && result.AsyncWriteAll)
 294                                 return;
 295
 296                         if (r.AsyncState != null) {
 297                                 result = (WebAsyncResult) r.AsyncState;
 298                                 result.InnerAsyncResult = r;
 299                                 result.DoCallback ();
 300                         } else {
 301                                 try {
 302                                         EndWrite (r);
 303                                 } catch {
 304                                 }
 305                         }
 306                 }
 307
 308                 void ReadCallbackWrapper (IAsyncResult r)
 309                 {
 310                         WebAsyncResult result;
 311                         if (r.AsyncState != null) {
 312                                 result = (WebAsyncResult) r.AsyncState;
 313                                 result.InnerAsyncResult = r;
 314                                 result.DoCallback ();
 315                         } else {
 316                                 try {
 317                                         EndRead (r);
 318                                 } catch {
 319                                 }
 320                         }
 321                 }
 322
 323                 public override int Read (byte [] buffer, int offset, int size)
 324                 {
 325                         AsyncCallback cb = cb_wrapper;
 326                         WebAsyncResult res = (WebAsyncResult) BeginRead (buffer, offset, size, cb, null);
 327                         if (!res.IsCompleted && !res.WaitUntilComplete (ReadTimeout, false)) {
 328                                 nextReadCalled = true;
 329                                 cnc.Close (true);
 330                                 throw new WebException ("The operation has timed out.", WebExceptionStatus.Timeout);
 331                         }
 332
 333                         return EndRead (res);
 334                 }
 335
 336                 public override IAsyncResult BeginRead (byte [] buffer, int offset, int size,
 337                                                         AsyncCallback cb, object state)
 338                 {
 339                         if (!isRead)
 340                                 throw new NotSupportedException ("this stream does not allow reading");
 341
 342                         if (buffer == null)
 343                                 throw new ArgumentNullException ("buffer");
 344
 345                         int length = buffer.Length;
 346                         if (offset < 0 || length < offset)
 347                                 throw new ArgumentOutOfRangeException ("offset");
 348                         if (size < 0 || (length - offset) < size)
 349                                 throw new ArgumentOutOfRangeException ("size");
 350
 351                         lock (locker) {
 352                                 pendingReads++;
 353                                 pending.Reset ();
 354                         }
 355
 356                         WebAsyncResult result = new WebAsyncResult (cb, state, buffer, offset, size);
 357                         if (totalRead >= contentLength) {
 358                                 result.SetCompleted (true, -1);
 359                                 result.DoCallback ();
 360                                 return result;
 361                         }
 362
 363                         int remaining = readBufferSize - readBufferOffset;
 364                         if (remaining > 0) {
 365                                 int copy = (remaining > size) ? size : remaining;
 366                                 Buffer.BlockCopy (readBuffer, readBufferOffset, buffer, offset, copy);
 367                                 readBufferOffset += copy;
 368                                 offset += copy;
 369                                 size -= copy;
 370                                 totalRead += copy;
 371                                 if (size == 0 || totalRead >= contentLength) {
 372                                         result.SetCompleted (true, copy);
 373                                         result.DoCallback ();
 374                                         return result;
 375                                 }
 376                                 result.NBytes = copy;
 377                         }
 378
 379                         if (cb != null)
 380                                 cb = cb_wrapper;
 381
 382                         if (contentLength != Int32.MaxValue && contentLength - totalRead < size)
 383                                 size = contentLength - totalRead;
 384
 385                         if (!read_eof) {
 386                                 result.InnerAsyncResult = cnc.BeginRead (request, buffer, offset, size, cb, result);
 387                         } else {
 388                                 result.SetCompleted (true, result.NBytes);
 389                                 result.DoCallback ();
 390                         }
 391                         return result;
 392                 }
 393
 394                 public override int EndRead (IAsyncResult r)
 395                 {
 396                         WebAsyncResult result = (WebAsyncResult) r;
 397                         if (result.EndCalled) {
 398                                 int xx = result.NBytes;
 399                                 return (xx >= 0) ? xx : 0;
 400                         }
 401
 402                         result.EndCalled = true;
 403
 404                         if (!result.IsCompleted) {
 405                                 int nbytes = -1;
 406                                 try {
 407                                         nbytes = cnc.EndRead (request, result);
 408                                 } catch (Exception exc) {
 409                                         lock (locker) {
 410                                                 pendingReads--;
 411                                                 if (pendingReads == 0)
 412                                                         pending.Set ();
 413                                         }
 414
 415                                         nextReadCalled = true;
 416                                         cnc.Close (true);
 417                                         result.SetCompleted (false, exc);
 418                                         result.DoCallback ();
 419                                         throw;
 420                                 }
 421
 422                                 if (nbytes < 0) {
 423                                         nbytes = 0;
 424                                         read_eof = true;
 425                                 }
 426
 427                                 totalRead += nbytes;
 428                                 result.SetCompleted (false, nbytes + result.NBytes);
 429                                 result.DoCallback ();
 430                                 if (nbytes == 0)
 431                                         contentLength = totalRead;
 432                         }
 433
 434                         lock (locker) {
 435                                 pendingReads--;
 436                                 if (pendingReads == 0)
 437                                         pending.Set ();
 438                         }
 439
 440                         if (totalRead >= contentLength && !nextReadCalled)
 441                                 ReadAll ();
 442
 443                         int nb = result.NBytes;
 444                         return (nb >= 0) ? nb : 0;
 445                 }
 446
 447                 void WriteRequestAsyncCB (IAsyncResult r)
 448                 {
 449                         WebAsyncResult result = (WebAsyncResult) r.AsyncState;
 450                         try {
 451                                 cnc.EndWrite2 (request, r);
 452                                 result.SetCompleted (false, 0);
 453                                 if (!initRead) {
 454                                         initRead = true;
 455                                         WebConnection.InitRead (cnc);
 456                                 }
 457                         } catch (Exception e) {
 458                                 KillBuffer ();
 459                                 nextReadCalled = true;
 460                                 cnc.Close (true);
 461                                 if (e is System.Net.Sockets.SocketException)
 462                                         e = new IOException ("Error writing request", e);
 463                                 result.SetCompleted (false, e);
 464                         }
 465                         complete_request_written = true;
 466                         result.DoCallback ();
 467                 }
 468
 469                 public override IAsyncResult BeginWrite (byte [] buffer, int offset, int size,
 470                                                         AsyncCallback cb, object state)
 471                 {
 472                         if (request.Aborted)
 473                                 throw new WebException ("The request was canceled.", null, WebExceptionStatus.RequestCanceled);
 474
 475                         if (isRead)
 476                                 throw new NotSupportedException ("this stream does not allow writing");
 477
 478                         if (buffer == null)
 479                                 throw new ArgumentNullException ("buffer");
 480
 481                         int length = buffer.Length;
 482                         if (offset < 0 || length < offset)
 483                                 throw new ArgumentOutOfRangeException ("offset");
 484                         if (size < 0 || (length - offset) < size)
 485                                 throw new ArgumentOutOfRangeException ("size");
 486
 487                         if (sendChunked) {
 488                                 lock (locker) {
 489                                         pendingWrites++;
 490                                         pending.Reset ();
 491                                 }
 492                         }
 493
 494                         WebAsyncResult result = new WebAsyncResult (cb, state);
 495                         if (!sendChunked)
 496                                 CheckWriteOverflow (request.ContentLength, totalWritten, size);
 497                         if (allowBuffering && !sendChunked) {
 498                                 if (writeBuffer == null)
 499                                         writeBuffer = new MemoryStream ();
 500                                 writeBuffer.Write (buffer, offset, size);
 501                                 totalWritten += size;
 502                                 if (request.ContentLength > 0 && totalWritten == request.ContentLength) {
 503                                         try {
 504                                                 result.AsyncWriteAll = true;
 505                                                 result.InnerAsyncResult = WriteRequestAsync (new AsyncCallback (WriteRequestAsyncCB), result);
 506                                                 if (result.InnerAsyncResult == null) {
 507                                                         if (!result.IsCompleted)
 508                                                                 result.SetCompleted (true, 0);
 509                                                         result.DoCallback ();
 510                                                 }
 511                                         } catch (Exception exc) {
 512                                                 result.SetCompleted (true, exc);
 513                                                 result.DoCallback ();
 514                                         }
 515                                 } else {
 516                                         result.SetCompleted (true, 0);
 517                                         result.DoCallback ();
 518                                 }
 519                                 return result;
 520                         }
 521
 522                         AsyncCallback callback = null;
 523                         if (cb != null)
 524                                 callback = cb_wrapper;
 525
 526                         if (sendChunked) {
 527                                 WriteRequest ();
 528
 529                                 string cSize = String.Format ("{0:X}\r\n", size);
 530                                 byte [] head = Encoding.ASCII.GetBytes (cSize);
 531                                 int chunkSize = 2 + size + head.Length;
 532                                 byte [] newBuffer = new byte [chunkSize];
 533                                 Buffer.BlockCopy (head, 0, newBuffer, 0, head.Length);
 534                                 Buffer.BlockCopy (buffer, offset, newBuffer, head.Length, size);
 535                                 Buffer.BlockCopy (crlf, 0, newBuffer, head.Length + size, crlf.Length);
 536
 537                                 buffer = newBuffer;
 538                                 offset = 0;
 539                                 size = chunkSize;
 540                         }
 541
 542                         try {
 543                                 result.InnerAsyncResult = cnc.BeginWrite (request, buffer, offset, size, callback, result);
 544                         } catch (Exception) {
 545                                 if (!IgnoreIOErrors)
 546                                         throw;
 547                                 result.SetCompleted (true, 0);
 548                                 result.DoCallback ();
 549                         }
 550                         totalWritten += size;
 551                         return result;
 552                 }
 553
 554                 void CheckWriteOverflow (long contentLength, long totalWritten, long size)
 555                 {
 556                         if (contentLength == -1)
 557                                 return;
 558
 559                         long avail = contentLength - totalWritten;
 560                         if (size > avail) {
 561                                 KillBuffer ();
 562                                 nextReadCalled = true;
 563                                 cnc.Close (true);
 564                                 throw new ProtocolViolationException (
 565                                         "The number of bytes to be written is greater than " +
 566                                         "the specified ContentLength.");
 567                         }
 568                 }
 569
 570                 public override void EndWrite (IAsyncResult r)
 571                 {
 572                         if (r == null)
 573                                 throw new ArgumentNullException ("r");
 574
 575                         WebAsyncResult result = r as WebAsyncResult;
 576                         if (result == null)
 577                                 throw new ArgumentException ("Invalid IAsyncResult");
 578
 579                         if (result.EndCalled)
 580                                 return;
 581
 582                         result.EndCalled = true;
 583                         if (result.AsyncWriteAll) {
 584                                 result.WaitUntilComplete ();
 585                                 if (result.GotException)
 586                                         throw result.Exception;
 587                                 return;
 588                         }
 589
 590                         if (allowBuffering && !sendChunked)
 591                                 return;
 592
 593                         if (result.GotException)
 594                                 throw result.Exception;
 595
 596                         try {
 597                                 cnc.EndWrite2 (request, result.InnerAsyncResult);
 598                                 result.SetCompleted (false, 0);
 599                                 result.DoCallback ();
 600                         } catch (Exception e) {
 601                                 if (IgnoreIOErrors)
 602                                         result.SetCompleted (false, 0);
 603                                 else
 604                                         result.SetCompleted (false, e);
 605                                 result.DoCallback ();
 606                                 if (!IgnoreIOErrors)
 607                                         throw;
 608                         } finally {
 609                                 if (sendChunked) {
 610                                         lock (locker) {
 611                                                 pendingWrites--;
 612                                                 if (pendingWrites == 0)
 613                                                         pending.Set ();
 614                                         }
 615                                 }
 616                         }
 617                 }
 618
 619                 public override void Write (byte [] buffer, int offset, int size)
 620                 {
 621                         AsyncCallback cb = cb_wrapper;
 622                         WebAsyncResult res = (WebAsyncResult) BeginWrite (buffer, offset, size, cb, null);
 623                         if (!res.IsCompleted && !res.WaitUntilComplete (WriteTimeout, false)) {
 624                                 KillBuffer ();
 625                                 nextReadCalled = true;
 626                                 cnc.Close (true);
 627                                 throw new IOException ("Write timed out.");
 628                         }
 629
 630                         EndWrite (res);
 631                 }
 632
 633                 public override void Flush ()
 634                 {
 635                 }
 636
 637                 internal void SetHeaders (byte [] buffer)
 638                 {
 639                         if (headersSent)
 640                                 return;
 641
 642                         headers = buffer;
 643                         long cl = request.ContentLength;
 644                         string method = request.Method;
 645                         bool no_writestream = (method == "GET" || method == "CONNECT" || method == "HEAD" ||
 646                                                 method == "TRACE");
 647                         if (sendChunked || cl > -1 || no_writestream) {
 648                                 WriteHeaders ();
 649                                 if (!initRead) {
 650                                         initRead = true;
 651                                         WebConnection.InitRead (cnc);
 652                                 }
 653                                 if (!sendChunked && cl == 0)
 654                                         requestWritten = true;
 655                         }
 656                 }
 657
 658                 internal bool RequestWritten {
 659                         get { return requestWritten; }
 660                 }
 661
 662                 IAsyncResult WriteRequestAsync (AsyncCallback cb, object state)
 663                 {
 664                         requestWritten = true;
 665                         byte [] bytes = writeBuffer.GetBuffer ();
 666                         int length = (int) writeBuffer.Length;
 667                         // Headers already written to the stream
 668                         return (length > 0) ? cnc.BeginWrite (request, bytes, 0, length, cb, state) : null;
 669                 }
 670
 671                 void WriteHeaders ()
 672                 {
 673                         if (headersSent)
 674                                 return;
 675
 676                         headersSent = true;
 677                         string err_msg = null;
 678                         if (!cnc.Write (request, headers, 0, headers.Length, ref err_msg))
 679                                 throw new WebException ("Error writing request: " + err_msg, null, WebExceptionStatus.SendFailure, null);
 680                 }
 681
 682                 internal void WriteRequest ()
 683                 {
 684                         if (requestWritten)
 685                                 return;
 686
 687                         requestWritten = true;
 688                         if (sendChunked)
 689                                 return;
 690
 691                         if (!allowBuffering || writeBuffer == null)
 692                                 return;
 693
 694                         byte [] bytes = writeBuffer.GetBuffer ();
 695                         int length = (int) writeBuffer.Length;
 696                         if (request.ContentLength != -1 && request.ContentLength < length) {
 697                                 nextReadCalled = true;
 698                                 cnc.Close (true);
 699                                 throw new WebException ("Specified Content-Length is less than the number of bytes to write", null,
 700                                                         WebExceptionStatus.ServerProtocolViolation, null);
 701                         }
 702
 703                         if (!headersSent) {
 704                                 string method = request.Method;
 705                                 bool no_writestream = (method == "GET" || method == "CONNECT" || method == "HEAD" ||
 706                                                         method == "TRACE");
 707                                 if (!no_writestream)
 708                                         request.InternalContentLength = length;
 709                                 request.SendRequestHeaders (true);
 710                         }
 711                         WriteHeaders ();
 712                         if (cnc.Data.StatusCode != 0 && cnc.Data.StatusCode != 100)
 713                                 return;
 714
 715                         IAsyncResult result = null;
 716                         if (length > 0)
 717                                 result = cnc.BeginWrite (request, bytes, 0, length, null, null);
 718
 719                         if (!initRead) {
 720                                 initRead = true;
 721                                 WebConnection.InitRead (cnc);
 722                         }
 723
 724                         if (length > 0)
 725                                 complete_request_written = cnc.EndWrite (request, result);
 726                         else
 727                                 complete_request_written = true;
 728                 }
 729
 730                 internal void InternalClose ()
 731                 {
 732                         disposed = true;
 733                 }
 734
 735                 public override void Close ()
 736                 {
 737                         if (sendChunked) {
 738                                 if (disposed)
 739                                         return;
 740                                 disposed = true;
 741                                 pending.WaitOne ();
 742                                 byte [] chunk = Encoding.ASCII.GetBytes ("0\r\n\r\n");
 743                                 string err_msg = null;
 744                                 cnc.Write (request, chunk, 0, chunk.Length, ref err_msg);
 745                                 return;
 746                         }
 747
 748                         if (isRead) {
 749                                 if (!nextReadCalled) {
 750                                         CheckComplete ();
 751                                         // If we have not read all the contents
 752                                         if (!nextReadCalled) {
 753                                                 nextReadCalled = true;
 754                                                 cnc.Close (true);
 755                                         }
 756                                 }
 757                                 return;
 758                         } else if (!allowBuffering) {
 759                                 complete_request_written = true;
 760                                 if (!initRead) {
 761                                         initRead = true;
 762                                         WebConnection.InitRead (cnc);
 763                                 }
 764                                 return;
 765                         }
 766
 767                         if (disposed || requestWritten)
 768                                 return;
 769
 770                         long length = request.ContentLength;
 771
 772                         if (!sendChunked && length != -1 && totalWritten != length) {
 773                                 IOException io = new IOException ("Cannot close the stream until all bytes are written");
 774                                 nextReadCalled = true;
 775                                 cnc.Close (true);
 776                                 throw new WebException ("Request was cancelled.", io, WebExceptionStatus.RequestCanceled);
 777                         }
 778
 779                         // Commented out the next line to fix xamarin bug #1512
 780                         //WriteRequest ();
 781                         disposed = true;
 782                 }
 783
 784                 internal void KillBuffer ()
 785                 {
 786                         writeBuffer = null;
 787                 }
 788
 789                 public override long Seek (long a, SeekOrigin b)
 790                 {
 791                         throw new NotSupportedException ();
 792                 }
 793
 794                 public override void SetLength (long a)
 795                 {
 796                         throw new NotSupportedException ();
 797                 }
 798
 799                 public override bool CanSeek {
 800                         get { return false; }
 801                 }
 802
 803                 public override bool CanRead {
 804                         get { return !disposed && isRead; }
 805                 }
 806
 807                 public override bool CanWrite {
 808                         get { return !disposed && !isRead; }
 809                 }
 810
 811                 public override long Length {
 812                         get {
 813                                 if (!isRead)
 814                                         throw new NotSupportedException ();
 815                                 return stream_length;
 816                         }
 817                 }
 818
 819                 public override long Position {
 820                         get { throw new NotSupportedException (); }
 821                         set { throw new NotSupportedException (); }
 822                 }
 823         }
 824 }
 825