mcs/class/System/System.Net/WebConnection.cs

   1 //
   2 // System.Net.WebConnection
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2003 Ximian, Inc (http://www.ximian.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.IO;
  32 using System.Collections;
  33 using System.Net.Sockets;
  34 using System.Security.Cryptography.X509Certificates;
  35 using System.Text;
  36 using System.Threading;
  37 using System.Diagnostics;
  38 using Mono.Net.Security;
  39
  40 namespace System.Net
  41 {
  42         enum ReadState
  43         {
  44                 None,
  45                 Status,
  46                 Headers,
  47                 Content,
  48                 Aborted
  49         }
  50
  51         class WebConnection
  52         {
  53                 ServicePoint sPoint;
  54                 Stream nstream;
  55                 internal Socket socket;
  56                 object socketLock = new object ();
  57                 IWebConnectionState state;
  58                 WebExceptionStatus status;
  59                 WaitCallback initConn;
  60                 bool keepAlive;
  61                 byte [] buffer;
  62                 static AsyncCallback readDoneDelegate = new AsyncCallback (ReadDone);
  63                 EventHandler abortHandler;
  64                 AbortHelper abortHelper;
  65                 internal WebConnectionData Data;
  66                 bool chunkedRead;
  67                 ChunkStream chunkStream;
  68                 Queue queue;
  69                 bool reused;
  70                 int position;
  71                 HttpWebRequest priority_request;
  72                 NetworkCredential ntlm_credentials;
  73                 bool ntlm_authenticated;
  74                 bool unsafe_sharing;
  75
  76                 enum NtlmAuthState
  77                 {
  78                         None,
  79                         Challenge,
  80                         Response
  81                 }
  82                 NtlmAuthState connect_ntlm_auth_state;
  83                 HttpWebRequest connect_request;
  84
  85                 Exception connect_exception;
  86                 static object classLock = new object ();
  87                 MonoTlsStream tlsStream;
  88
  89 #if MONOTOUCH && !MONOTOUCH_TV && !MONOTOUCH_WATCH
  90                 [System.Runtime.InteropServices.DllImport ("__Internal")]
  91                 static extern void xamarin_start_wwan (string uri);
  92 #endif
  93
  94                 internal ChunkStream ChunkStream {
  95                         get { return chunkStream; }
  96                 }
  97
  98                 public WebConnection (IWebConnectionState wcs, ServicePoint sPoint)
  99                 {
 100                         this.state = wcs;
 101                         this.sPoint = sPoint;
 102                         buffer = new byte [4096];
 103                         Data = new WebConnectionData ();
 104                         initConn = new WaitCallback (state => {
 105                                 try {
 106                                         InitConnection (state);
 107                                 } catch {}
 108                                 });
 109                         queue = wcs.Group.Queue;
 110                         abortHelper = new AbortHelper ();
 111                         abortHelper.Connection = this;
 112                         abortHandler = new EventHandler (abortHelper.Abort);
 113                 }
 114
 115                 class AbortHelper {
 116                         public WebConnection Connection;
 117
 118                         public void Abort (object sender, EventArgs args)
 119                         {
 120                                 WebConnection other = ((HttpWebRequest) sender).WebConnection;
 121                                 if (other == null)
 122                                         other = Connection;
 123                                 other.Abort (sender, args);
 124                         }
 125                 }
 126
 127                 bool CanReuse ()
 128                 {
 129                         // The real condition is !(socket.Poll (0, SelectMode.SelectRead) || socket.Available != 0)
 130                         // but if there's data pending to read (!) we won't reuse the socket.
 131                         return (socket.Poll (0, SelectMode.SelectRead) == false);
 132                 }
 133
 134                 void Connect (HttpWebRequest request)
 135                 {
 136                         lock (socketLock) {
 137                                 if (socket != null && socket.Connected && status == WebExceptionStatus.Success) {
 138                                         // Take the chunked stream to the expected state (State.None)
 139                                         if (CanReuse () && CompleteChunkedRead ()) {
 140                                                 reused = true;
 141                                                 return;
 142                                         }
 143                                 }
 144
 145                                 reused = false;
 146                                 if (socket != null) {
 147                                         socket.Close();
 148                                         socket = null;
 149                                 }
 150
 151                                 chunkStream = null;
 152                                 IPHostEntry hostEntry = sPoint.HostEntry;
 153
 154                                 if (hostEntry == null) {
 155 #if MONOTOUCH && !MONOTOUCH_TV && !MONOTOUCH_WATCH
 156                                         xamarin_start_wwan (sPoint.Address.ToString ());
 157                                         hostEntry = sPoint.HostEntry;
 158                                         if (hostEntry == null) {
 159 #endif
 160                                                 status = sPoint.UsesProxy ? WebExceptionStatus.ProxyNameResolutionFailure :
 161                                                                             WebExceptionStatus.NameResolutionFailure;
 162                                                 return;
 163 #if MONOTOUCH && !MONOTOUCH_TV && !MONOTOUCH_WATCH
 164                                         }
 165 #endif
 166                                 }
 167
 168                                 //WebConnectionData data = Data;
 169                                 foreach (IPAddress address in hostEntry.AddressList) {
 170                                         try {
 171                                                 socket = new Socket (address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
 172                                         } catch (Exception se) {
 173                                                 // The Socket ctor can throw if we run out of FD's
 174                                                 if (!request.Aborted)
 175                                                                 status = WebExceptionStatus.ConnectFailure;
 176                                                 connect_exception = se;
 177                                                 return;
 178                                         }
 179                                         IPEndPoint remote = new IPEndPoint (address, sPoint.Address.Port);
 180                                         socket.NoDelay = !sPoint.UseNagleAlgorithm;
 181                                         try {
 182                                                 sPoint.KeepAliveSetup (socket);
 183                                         } catch {
 184                                                 // Ignore. Not supported in all platforms.
 185                                         }
 186
 187                                         if (!sPoint.CallEndPointDelegate (socket, remote)) {
 188                                                 socket.Close ();
 189                                                 socket = null;
 190                                                 status = WebExceptionStatus.ConnectFailure;
 191                                         } else {
 192                                                 try {
 193                                                         if (request.Aborted)
 194                                                                 return;
 195                                                         socket.Connect (remote);
 196                                                         status = WebExceptionStatus.Success;
 197                                                         break;
 198                                                 } catch (ThreadAbortException) {
 199                                                         // program exiting...
 200                                                         Socket s = socket;
 201                                                         socket = null;
 202                                                         if (s != null)
 203                                                                 s.Close ();
 204                                                         return;
 205                                                 } catch (ObjectDisposedException) {
 206                                                         // socket closed from another thread
 207                                                         return;
 208                                                 } catch (Exception exc) {
 209                                                         Socket s = socket;
 210                                                         socket = null;
 211                                                         if (s != null)
 212                                                                 s.Close ();
 213                                                         if (!request.Aborted)
 214                                                                 status = WebExceptionStatus.ConnectFailure;
 215                                                         connect_exception = exc;
 216                                                 }
 217                                         }
 218                                 }
 219                         }
 220                 }
 221
 222                 bool CreateTunnel (HttpWebRequest request, Uri connectUri,
 223                                    Stream stream, out byte[] buffer)
 224                 {
 225                         StringBuilder sb = new StringBuilder ();
 226                         sb.Append ("CONNECT ");
 227                         sb.Append (request.Address.Host);
 228                         sb.Append (':');
 229                         sb.Append (request.Address.Port);
 230                         sb.Append (" HTTP/");
 231                         if (request.ServicePoint.ProtocolVersion == HttpVersion.Version11)
 232                                 sb.Append ("1.1");
 233                         else
 234                                 sb.Append ("1.0");
 235
 236                         sb.Append ("\r\nHost: ");
 237                         sb.Append (request.Address.Authority);
 238
 239                         bool ntlm = false;
 240                         var challenge = Data.Challenge;
 241                         Data.Challenge = null;
 242                         var auth_header = request.Headers ["Proxy-Authorization"];
 243                         bool have_auth = auth_header != null;
 244                         if (have_auth) {
 245                                 sb.Append ("\r\nProxy-Authorization: ");
 246                                 sb.Append (auth_header);
 247                                 ntlm = auth_header.ToUpper ().Contains ("NTLM");
 248                         } else if (challenge != null && Data.StatusCode == 407) {
 249                                 ICredentials creds = request.Proxy.Credentials;
 250                                 have_auth = true;
 251
 252                                 if (connect_request == null) {
 253                                         // create a CONNECT request to use with Authenticate
 254                                         connect_request = (HttpWebRequest)WebRequest.Create (
 255                                                 connectUri.Scheme + "://" + connectUri.Host + ":" + connectUri.Port + "/");
 256                                         connect_request.Method = "CONNECT";
 257                                         connect_request.Credentials = creds;
 258                                 }
 259
 260                                 for (int i = 0; i < challenge.Length; i++) {
 261                                         var auth = AuthenticationManager.Authenticate (challenge [i], connect_request, creds);
 262                                         if (auth == null)
 263                                                 continue;
 264                                         ntlm = (auth.ModuleAuthenticationType == "NTLM");
 265                                         sb.Append ("\r\nProxy-Authorization: ");
 266                                         sb.Append (auth.Message);
 267                                         break;
 268                                 }
 269                         }
 270
 271                         if (ntlm) {
 272                                 sb.Append ("\r\nProxy-Connection: keep-alive");
 273                                 connect_ntlm_auth_state++;
 274                         }
 275
 276                         sb.Append ("\r\n\r\n");
 277
 278                         Data.StatusCode = 0;
 279                         byte [] connectBytes = Encoding.Default.GetBytes (sb.ToString ());
 280                         stream.Write (connectBytes, 0, connectBytes.Length);
 281
 282                         int status;
 283                         WebHeaderCollection result = ReadHeaders (stream, out buffer, out status);
 284                         if ((!have_auth || connect_ntlm_auth_state == NtlmAuthState.Challenge) &&
 285                             result != null && status == 407) { // Needs proxy auth
 286                                 var connectionHeader = result ["Connection"];
 287                                 if (socket != null && !string.IsNullOrEmpty (connectionHeader) &&
 288                                     connectionHeader.ToLower() == "close") {
 289                                         // The server is requesting that this connection be closed
 290                                         socket.Close();
 291                                         socket = null;
 292                                 }
 293
 294                                 Data.StatusCode = status;
 295                                 Data.Challenge = result.GetValues ("Proxy-Authentic");
 296                                 return false;
 297                         } else if (status != 200) {
 298                                 string msg = String.Format ("The remote server returned a {0} status code.", status);
 299                                 HandleError (WebExceptionStatus.SecureChannelFailure, null, msg);
 300                                 return false;
 301                         }
 302
 303                         return (result != null);
 304                 }
 305
 306                 WebHeaderCollection ReadHeaders (Stream stream, out byte [] retBuffer, out int status)
 307                 {
 308                         retBuffer = null;
 309                         status = 200;
 310
 311                         byte [] buffer = new byte [1024];
 312                         MemoryStream ms = new MemoryStream ();
 313
 314                         while (true) {
 315                                 int n = stream.Read (buffer, 0, 1024);
 316                                 if (n == 0) {
 317                                         HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders");
 318                                         return null;
 319                                 }
 320
 321                                 ms.Write (buffer, 0, n);
 322                                 int start = 0;
 323                                 string str = null;
 324                                 bool gotStatus = false;
 325                                 WebHeaderCollection headers = new WebHeaderCollection ();
 326                                 while (ReadLine (ms.GetBuffer (), ref start, (int) ms.Length, ref str)) {
 327                                         if (str == null) {
 328                                                 int contentLen = 0;
 329                                                 try     {
 330                                                         contentLen = int.Parse(headers["Content-Length"]);
 331                                                 }
 332                                                 catch {
 333                                                         contentLen = 0;
 334                                                 }
 335
 336                                                 if (ms.Length - start - contentLen > 0) {
 337                                                         // we've read more data than the response header and conents,
 338                                                         // give back extra data to the caller
 339                                                         retBuffer = new byte[ms.Length - start - contentLen];
 340                                                         Buffer.BlockCopy(ms.GetBuffer(), start + contentLen, retBuffer, 0, retBuffer.Length);
 341                                                 }
 342                                                 else {
 343                                                         // haven't read in some or all of the contents for the response, do so now
 344                                                         FlushContents(stream, contentLen - (int)(ms.Length - start));
 345                                                 }
 346
 347                                                 return headers;
 348                                         }
 349
 350                                         if (gotStatus) {
 351                                                 headers.Add (str);
 352                                                 continue;
 353                                         }
 354
 355                                         string[] parts = str.Split (' ');
 356                                         if (parts.Length < 2) {
 357                                                 HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders2");
 358                                                 return null;
 359                                         }
 360
 361                                         if (String.Compare (parts [0], "HTTP/1.1", true) == 0)
 362                                                 Data.ProxyVersion = HttpVersion.Version11;
 363                                         else if (String.Compare (parts [0], "HTTP/1.0", true) == 0)
 364                                                 Data.ProxyVersion = HttpVersion.Version10;
 365                                         else {
 366                                                 HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders2");
 367                                                 return null;
 368                                         }
 369
 370                                         status = (int)UInt32.Parse (parts [1]);
 371                                         gotStatus = true;
 372                                 }
 373                         }
 374                 }
 375
 376                 void FlushContents(Stream stream, int contentLength)
 377                 {
 378                         while (contentLength > 0) {
 379                                 byte[] contentBuffer = new byte[contentLength];
 380                                 int bytesRead = stream.Read(contentBuffer, 0, contentLength);
 381                                 if (bytesRead > 0) {
 382                                         contentLength -= bytesRead;
 383                                 }
 384                                 else {
 385                                         break;
 386                                 }
 387                         }
 388                 }
 389
 390                 bool CreateStream (HttpWebRequest request)
 391                 {
 392                         try {
 393                                 NetworkStream serverStream = new NetworkStream (socket, false);
 394
 395                                 if (request.Address.Scheme == Uri.UriSchemeHttps) {
 396 #if SECURITY_DEP
 397                                         if (!reused || nstream == null || tlsStream == null) {
 398                                                 byte [] buffer = null;
 399                                                 if (sPoint.UseConnect) {
 400                                                         bool ok = CreateTunnel (request, sPoint.Address, serverStream, out buffer);
 401                                                         if (!ok)
 402                                                                 return false;
 403                                                 }
 404                                                 tlsStream = new MonoTlsStream (request, serverStream);
 405                                                 nstream = tlsStream.CreateStream (buffer);
 406                                         }
 407                                         // we also need to set ServicePoint.Certificate
 408                                         // and ServicePoint.ClientCertificate but this can
 409                                         // only be done later (after handshake - which is
 410                                         // done only after a read operation).
 411 #else
 412                                         throw new NotSupportedException ();
 413 #endif
 414                                 } else {
 415                                         nstream = serverStream;
 416                                 }
 417                         } catch (Exception ex) {
 418                                 if (tlsStream != null)
 419                                         status = tlsStream.ExceptionStatus;
 420                                 else if (!request.Aborted)
 421                                         status = WebExceptionStatus.ConnectFailure;
 422                                 connect_exception = ex;
 423                                 return false;
 424                         }
 425
 426                         return true;
 427                 }
 428
 429                 void HandleError (WebExceptionStatus st, Exception e, string where)
 430                 {
 431                         status = st;
 432                         lock (this) {
 433                                 if (st == WebExceptionStatus.RequestCanceled)
 434                                         Data = new WebConnectionData ();
 435                         }
 436
 437                         if (e == null) { // At least we now where it comes from
 438                                 try {
 439                                         throw new Exception (new System.Diagnostics.StackTrace ().ToString ());
 440                                 } catch (Exception e2) {
 441                                         e = e2;
 442                                 }
 443                         }
 444
 445                         HttpWebRequest req = null;
 446                         if (Data != null && Data.request != null)
 447                                 req = Data.request;
 448
 449                         Close (true);
 450                         if (req != null) {
 451                                 req.FinishedReading = true;
 452                                 req.SetResponseError (st, e, where);
 453                         }
 454                 }
 455
 456                 static void ReadDone (IAsyncResult result)
 457                 {
 458                         WebConnection cnc = (WebConnection)result.AsyncState;
 459                         WebConnectionData data = cnc.Data;
 460                         Stream ns = cnc.nstream;
 461                         if (ns == null) {
 462                                 cnc.Close (true);
 463                                 return;
 464                         }
 465
 466                         int nread = -1;
 467                         try {
 468                                 nread = ns.EndRead (result);
 469                         } catch (ObjectDisposedException) {
 470                                 return;
 471                         } catch (Exception e) {
 472                                 if (e.InnerException is ObjectDisposedException)
 473                                         return;
 474
 475                                 cnc.HandleError (WebExceptionStatus.ReceiveFailure, e, "ReadDone1");
 476                                 return;
 477                         }
 478
 479                         if (nread == 0) {
 480                                 cnc.HandleError (WebExceptionStatus.ReceiveFailure, null, "ReadDone2");
 481                                 return;
 482                         }
 483
 484                         if (nread < 0) {
 485                                 cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadDone3");
 486                                 return;
 487                         }
 488
 489                         int pos = -1;
 490                         nread += cnc.position;
 491                         if (data.ReadState == ReadState.None) {
 492                                 Exception exc = null;
 493                                 try {
 494                                         pos = GetResponse (data, cnc.sPoint, cnc.buffer, nread);
 495                                 } catch (Exception e) {
 496                                         exc = e;
 497                                 }
 498
 499                                 if (exc != null || pos == -1) {
 500                                         cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, exc, "ReadDone4");
 501                                         return;
 502                                 }
 503                         }
 504
 505                         if (data.ReadState == ReadState.Aborted) {
 506                                 cnc.HandleError (WebExceptionStatus.RequestCanceled, null, "ReadDone");
 507                                 return;
 508                         }
 509
 510                         if (data.ReadState != ReadState.Content) {
 511                                 int est = nread * 2;
 512                                 int max = (est < cnc.buffer.Length) ? cnc.buffer.Length : est;
 513                                 byte [] newBuffer = new byte [max];
 514                                 Buffer.BlockCopy (cnc.buffer, 0, newBuffer, 0, nread);
 515                                 cnc.buffer = newBuffer;
 516                                 cnc.position = nread;
 517                                 data.ReadState = ReadState.None;
 518                                 InitRead (cnc);
 519                                 return;
 520                         }
 521
 522                         cnc.position = 0;
 523
 524                         WebConnectionStream stream = new WebConnectionStream (cnc, data);
 525                         bool expect_content = ExpectContent (data.StatusCode, data.request.Method);
 526                         string tencoding = null;
 527                         if (expect_content)
 528                                 tencoding = data.Headers ["Transfer-Encoding"];
 529
 530                         cnc.chunkedRead = (tencoding != null && tencoding.IndexOf ("chunked", StringComparison.OrdinalIgnoreCase) != -1);
 531                         if (!cnc.chunkedRead) {
 532                                 stream.ReadBuffer = cnc.buffer;
 533                                 stream.ReadBufferOffset = pos;
 534                                 stream.ReadBufferSize = nread;
 535                                 try {
 536                                         stream.CheckResponseInBuffer ();
 537                                 } catch (Exception e) {
 538                                         cnc.HandleError (WebExceptionStatus.ReceiveFailure, e, "ReadDone7");
 539                                 }
 540                         } else if (cnc.chunkStream == null) {
 541                                 try {
 542                                         cnc.chunkStream = new ChunkStream (cnc.buffer, pos, nread, data.Headers);
 543                                 } catch (Exception e) {
 544                                         cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, e, "ReadDone5");
 545                                         return;
 546                                 }
 547                         } else {
 548                                 cnc.chunkStream.ResetBuffer ();
 549                                 try {
 550                                         cnc.chunkStream.Write (cnc.buffer, pos, nread);
 551                                 } catch (Exception e) {
 552                                         cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, e, "ReadDone6");
 553                                         return;
 554                                 }
 555                         }
 556
 557                         data.stream = stream;
 558
 559                         if (!expect_content)
 560                                 stream.ForceCompletion ();
 561
 562                         data.request.SetResponseData (data);
 563                 }
 564
 565                 static bool ExpectContent (int statusCode, string method)
 566                 {
 567                         if (method == "HEAD")
 568                                 return false;
 569                         return (statusCode >= 200 && statusCode != 204 && statusCode != 304);
 570                 }
 571
 572                 internal static void InitRead (object state)
 573                 {
 574                         WebConnection cnc = (WebConnection) state;
 575                         Stream ns = cnc.nstream;
 576
 577                         try {
 578                                 int size = cnc.buffer.Length - cnc.position;
 579                                 ns.BeginRead (cnc.buffer, cnc.position, size, readDoneDelegate, cnc);
 580                         } catch (Exception e) {
 581                                 cnc.HandleError (WebExceptionStatus.ReceiveFailure, e, "InitRead");
 582                         }
 583                 }
 584
 585                 static int GetResponse (WebConnectionData data, ServicePoint sPoint,
 586                                         byte [] buffer, int max)
 587                 {
 588                         int pos = 0;
 589                         string line = null;
 590                         bool lineok = false;
 591                         bool isContinue = false;
 592                         bool emptyFirstLine = false;
 593                         do {
 594                                 if (data.ReadState == ReadState.Aborted)
 595                                         return -1;
 596
 597                                 if (data.ReadState == ReadState.None) {
 598                                         lineok = ReadLine (buffer, ref pos, max, ref line);
 599                                         if (!lineok)
 600                                                 return 0;
 601
 602                                         if (line == null) {
 603                                                 emptyFirstLine = true;
 604                                                 continue;
 605                                         }
 606                                         emptyFirstLine = false;
 607                                         data.ReadState = ReadState.Status;
 608
 609                                         string [] parts = line.Split (' ');
 610                                         if (parts.Length < 2)
 611                                                 return -1;
 612
 613                                         if (String.Compare (parts [0], "HTTP/1.1", true) == 0) {
 614                                                 data.Version = HttpVersion.Version11;
 615                                                 sPoint.SetVersion (HttpVersion.Version11);
 616                                         } else {
 617                                                 data.Version = HttpVersion.Version10;
 618                                                 sPoint.SetVersion (HttpVersion.Version10);
 619                                         }
 620
 621                                         data.StatusCode = (int) UInt32.Parse (parts [1]);
 622                                         if (parts.Length >= 3)
 623                                                 data.StatusDescription = String.Join (" ", parts, 2, parts.Length - 2);
 624                                         else
 625                                                 data.StatusDescription = "";
 626
 627                                         if (pos >= max)
 628                                                 return pos;
 629                                 }
 630
 631                                 emptyFirstLine = false;
 632                                 if (data.ReadState == ReadState.Status) {
 633                                         data.ReadState = ReadState.Headers;
 634                                         data.Headers = new WebHeaderCollection ();
 635                                         ArrayList headers = new ArrayList ();
 636                                         bool finished = false;
 637                                         while (!finished) {
 638                                                 if (ReadLine (buffer, ref pos, max, ref line) == false)
 639                                                         break;
 640
 641                                                 if (line == null) {
 642                                                         // Empty line: end of headers
 643                                                         finished = true;
 644                                                         continue;
 645                                                 }
 646
 647                                                 if (line.Length > 0 && (line [0] == ' ' || line [0] == '\t')) {
 648                                                         int count = headers.Count - 1;
 649                                                         if (count < 0)
 650                                                                 break;
 651
 652                                                         string prev = (string) headers [count] + line;
 653                                                         headers [count] = prev;
 654                                                 } else {
 655                                                         headers.Add (line);
 656                                                 }
 657                                         }
 658
 659                                         if (!finished)
 660                                                 return 0;
 661
 662                                         // .NET uses ParseHeaders or ParseHeadersStrict which is much better
 663                                         foreach (string s in headers) {
 664
 665                                                 int pos_s = s.IndexOf (':');
 666                                                 if (pos_s == -1)
 667                                                         throw new ArgumentException ("no colon found", "header");
 668
 669                                                 var header = s.Substring (0, pos_s);
 670                                                 var value = s.Substring (pos_s + 1).Trim ();
 671
 672                                                 var h = data.Headers;
 673                                                 if (h.AllowMultiValues (header)) {
 674                                                         h.AddInternal (header, value);
 675                                                 } else  {
 676                                                         h.SetInternal (header, value);
 677                                                 }
 678                                         }
 679
 680                                         if (data.StatusCode == (int) HttpStatusCode.Continue) {
 681                                                 sPoint.SendContinue = true;
 682                                                 if (pos >= max)
 683                                                         return pos;
 684
 685                                                 if (data.request.ExpectContinue) {
 686                                                         data.request.DoContinueDelegate (data.StatusCode, data.Headers);
 687                                                         // Prevent double calls when getting the
 688                                                         // headers in several packets.
 689                                                         data.request.ExpectContinue = false;
 690                                                 }
 691
 692                                                 data.ReadState = ReadState.None;
 693                                                 isContinue = true;
 694                                         }
 695                                         else {
 696                                                 data.ReadState = ReadState.Content;
 697                                                 return pos;
 698                                         }
 699                                 }
 700                         } while (emptyFirstLine || isContinue);
 701
 702                         return -1;
 703                 }
 704
 705                 void InitConnection (object state)
 706                 {
 707                         HttpWebRequest request = (HttpWebRequest) state;
 708                         request.WebConnection = this;
 709                         if (request.ReuseConnection)
 710                                 request.StoredConnection = this;
 711
 712                         if (request.Aborted)
 713                                 return;
 714
 715                         keepAlive = request.KeepAlive;
 716                         Data = new WebConnectionData (request);
 717                 retry:
 718                         Connect (request);
 719                         if (request.Aborted)
 720                                 return;
 721
 722                         if (status != WebExceptionStatus.Success) {
 723                                 if (!request.Aborted) {
 724                                         request.SetWriteStreamError (status, connect_exception);
 725                                         Close (true);
 726                                 }
 727                                 return;
 728                         }
 729
 730                         if (!CreateStream (request)) {
 731                                 if (request.Aborted)
 732                                         return;
 733
 734                                 WebExceptionStatus st = status;
 735                                 if (Data.Challenge != null)
 736                                         goto retry;
 737
 738                                 Exception cnc_exc = connect_exception;
 739                                 connect_exception = null;
 740                                 request.SetWriteStreamError (st, cnc_exc);
 741                                 Close (true);
 742                                 return;
 743                         }
 744
 745                         request.SetWriteStream (new WebConnectionStream (this, request));
 746                 }
 747
 748 #if MONOTOUCH
 749                 static bool warned_about_queue = false;
 750 #endif
 751
 752                 internal EventHandler SendRequest (HttpWebRequest request)
 753                 {
 754                         if (request.Aborted)
 755                                 return null;
 756
 757                         lock (this) {
 758                                 if (state.TrySetBusy ()) {
 759                                         status = WebExceptionStatus.Success;
 760                                         ThreadPool.QueueUserWorkItem (initConn, request);
 761                                 } else {
 762                                         lock (queue) {
 763 #if MONOTOUCH
 764                                                 if (!warned_about_queue) {
 765                                                         warned_about_queue = true;
 766                                                         Console.WriteLine ("WARNING: An HttpWebRequest was added to the ConnectionGroup queue because the connection limit was reached.");
 767                                                 }
 768 #endif
 769                                                 queue.Enqueue (request);
 770                                         }
 771                                 }
 772                         }
 773
 774                         return abortHandler;
 775                 }
 776
 777                 void SendNext ()
 778                 {
 779                         lock (queue) {
 780                                 if (queue.Count > 0) {
 781                                         SendRequest ((HttpWebRequest) queue.Dequeue ());
 782                                 }
 783                         }
 784                 }
 785
 786                 internal void NextRead ()
 787                 {
 788                         lock (this) {
 789                                 if (Data.request != null)
 790                                         Data.request.FinishedReading = true;
 791                                 string header = (sPoint.UsesProxy) ? "Proxy-Connection" : "Connection";
 792                                 string cncHeader = (Data.Headers != null) ? Data.Headers [header] : null;
 793                                 bool keepAlive = (Data.Version == HttpVersion.Version11 && this.keepAlive);
 794                                 if (Data.ProxyVersion != null && Data.ProxyVersion != HttpVersion.Version11)
 795                                         keepAlive = false;
 796                                 if (cncHeader != null) {
 797                                         cncHeader = cncHeader.ToLower ();
 798                                         keepAlive = (this.keepAlive && cncHeader.IndexOf ("keep-alive", StringComparison.Ordinal) != -1);
 799                                 }
 800
 801                                 if ((socket != null && !socket.Connected) ||
 802                                    (!keepAlive || (cncHeader != null && cncHeader.IndexOf ("close", StringComparison.Ordinal) != -1))) {
 803                                         Close (false);
 804                                 }
 805
 806                                 state.SetIdle ();
 807                                 if (priority_request != null) {
 808                                         SendRequest (priority_request);
 809                                         priority_request = null;
 810                                 } else {
 811                                         SendNext ();
 812                                 }
 813                         }
 814                 }
 815
 816                 static bool ReadLine (byte [] buffer, ref int start, int max, ref string output)
 817                 {
 818                         bool foundCR = false;
 819                         StringBuilder text = new StringBuilder ();
 820
 821                         int c = 0;
 822                         while (start < max) {
 823                                 c = (int) buffer [start++];
 824
 825                                 if (c == '\n') {                        // newline
 826                                         if ((text.Length > 0) && (text [text.Length - 1] == '\r'))
 827                                                 text.Length--;
 828
 829                                         foundCR = false;
 830                                         break;
 831                                 } else if (foundCR) {
 832                                         text.Length--;
 833                                         break;
 834                                 }
 835
 836                                 if (c == '\r')
 837                                         foundCR = true;
 838
 839
 840                                 text.Append ((char) c);
 841                         }
 842
 843                         if (c != '\n' && c != '\r')
 844                                 return false;
 845
 846                         if (text.Length == 0) {
 847                                 output = null;
 848                                 return (c == '\n' || c == '\r');
 849                         }
 850
 851                         if (foundCR)
 852                                 text.Length--;
 853
 854                         output = text.ToString ();
 855                         return true;
 856                 }
 857
 858
 859                 internal IAsyncResult BeginRead (HttpWebRequest request, byte [] buffer, int offset, int size, AsyncCallback cb, object state)
 860                 {
 861                         Stream s = null;
 862                         lock (this) {
 863                                 if (Data.request != request)
 864                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 865                                 if (nstream == null)
 866                                         return null;
 867                                 s = nstream;
 868                         }
 869
 870                         IAsyncResult result = null;
 871                         if (!chunkedRead || (!chunkStream.DataAvailable && chunkStream.WantMore)) {
 872                                 try {
 873                                         result = s.BeginRead (buffer, offset, size, cb, state);
 874                                         cb = null;
 875                                 } catch (Exception) {
 876                                         HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked BeginRead");
 877                                         throw;
 878                                 }
 879                         }
 880
 881                         if (chunkedRead) {
 882                                 WebAsyncResult wr = new WebAsyncResult (cb, state, buffer, offset, size);
 883                                 wr.InnerAsyncResult = result;
 884                                 if (result == null) {
 885                                         // Will be completed from the data in ChunkStream
 886                                         wr.SetCompleted (true, (Exception) null);
 887                                         wr.DoCallback ();
 888                                 }
 889                                 return wr;
 890                         }
 891
 892                         return result;
 893                 }
 894
 895                 internal int EndRead (HttpWebRequest request, IAsyncResult result)
 896                 {
 897                         Stream s = null;
 898                         lock (this) {
 899                                 if (Data.request != request)
 900                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 901                                 if (nstream == null)
 902                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 903                                 s = nstream;
 904                         }
 905
 906                         int nbytes = 0;
 907                         bool done = false;
 908                         WebAsyncResult wr = null;
 909                         IAsyncResult nsAsync = ((WebAsyncResult) result).InnerAsyncResult;
 910                         if (chunkedRead && (nsAsync is WebAsyncResult)) {
 911                                 wr = (WebAsyncResult) nsAsync;
 912                                 IAsyncResult inner = wr.InnerAsyncResult;
 913                                 if (inner != null && !(inner is WebAsyncResult)) {
 914                                         nbytes = s.EndRead (inner);
 915                                         done = nbytes == 0;
 916                                 }
 917                         } else if (!(nsAsync is WebAsyncResult)) {
 918                                 nbytes = s.EndRead (nsAsync);
 919                                 wr = (WebAsyncResult) result;
 920                                 done = nbytes == 0;
 921                         }
 922
 923                         if (chunkedRead) {
 924                                 try {
 925                                         chunkStream.WriteAndReadBack (wr.Buffer, wr.Offset, wr.Size, ref nbytes);
 926                                         if (!done && nbytes == 0 && chunkStream.WantMore)
 927                                                 nbytes = EnsureRead (wr.Buffer, wr.Offset, wr.Size);
 928                                 } catch (Exception e) {
 929                                         if (e is WebException)
 930                                                 throw e;
 931
 932                                         throw new WebException ("Invalid chunked data.", e,
 933                                                                 WebExceptionStatus.ServerProtocolViolation, null);
 934                                 }
 935
 936                                 if ((done || nbytes == 0) && chunkStream.ChunkLeft != 0) {
 937                                         HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked EndRead");
 938                                         throw new WebException ("Read error", null, WebExceptionStatus.ReceiveFailure, null);
 939                                 }
 940                         }
 941
 942                         return (nbytes != 0) ? nbytes : -1;
 943                 }
 944
 945                 // To be called on chunkedRead when we can read no data from the ChunkStream yet
 946                 int EnsureRead (byte [] buffer, int offset, int size)
 947                 {
 948                         byte [] morebytes = null;
 949                         int nbytes = 0;
 950                         while (nbytes == 0 && chunkStream.WantMore) {
 951                                 int localsize = chunkStream.ChunkLeft;
 952                                 if (localsize <= 0) // not read chunk size yet
 953                                         localsize = 1024;
 954                                 else if (localsize > 16384)
 955                                         localsize = 16384;
 956
 957                                 if (morebytes == null || morebytes.Length < localsize)
 958                                         morebytes = new byte [localsize];
 959
 960                                 int nread = nstream.Read (morebytes, 0, localsize);
 961                                 if (nread <= 0)
 962                                         return 0; // Error
 963
 964                                 chunkStream.Write (morebytes, 0, nread);
 965                                 nbytes += chunkStream.Read (buffer, offset + nbytes, size - nbytes);
 966                         }
 967
 968                         return nbytes;
 969                 }
 970
 971                 bool CompleteChunkedRead()
 972                 {
 973                         if (!chunkedRead || chunkStream == null)
 974                                 return true;
 975
 976                         while (chunkStream.WantMore) {
 977                                 int nbytes = nstream.Read (buffer, 0, buffer.Length);
 978                                 if (nbytes <= 0)
 979                                         return false; // Socket was disconnected
 980
 981                                 chunkStream.Write (buffer, 0, nbytes);
 982                         }
 983
 984                         return true;
 985                 }
 986
 987                 internal IAsyncResult BeginWrite (HttpWebRequest request, byte [] buffer, int offset, int size, AsyncCallback cb, object state)
 988                 {
 989                         Stream s = null;
 990                         lock (this) {
 991                                 if (Data.request != request)
 992                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 993                                 if (nstream == null)
 994                                         return null;
 995                                 s = nstream;
 996                         }
 997
 998                         IAsyncResult result = null;
 999                         try {
1000                                 result = s.BeginWrite (buffer, offset, size, cb, state);
1001                         } catch (Exception) {
1002                                 status = WebExceptionStatus.SendFailure;
1003                                 throw;
1004                         }
1005
1006                         return result;
1007                 }
1008
1009                 internal bool EndWrite (HttpWebRequest request, bool throwOnError, IAsyncResult result)
1010                 {
1011                         Stream s = null;
1012                         lock (this) {
1013                                 if (status == WebExceptionStatus.RequestCanceled)
1014                                         return true;
1015                                 if (Data.request != request)
1016                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1017                                 if (nstream == null)
1018                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1019                                 s = nstream;
1020                         }
1021
1022                         try {
1023                                 s.EndWrite (result);
1024                                 return true;
1025                         } catch (Exception exc) {
1026                                 status = WebExceptionStatus.SendFailure;
1027                                 if (throwOnError && exc.InnerException != null)
1028                                         throw exc.InnerException;
1029                                 return false;
1030                         }
1031                 }
1032
1033                 internal int Read (HttpWebRequest request, byte [] buffer, int offset, int size)
1034                 {
1035                         Stream s = null;
1036                         lock (this) {
1037                                 if (Data.request != request)
1038                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1039                                 if (nstream == null)
1040                                         return 0;
1041                                 s = nstream;
1042                         }
1043
1044                         int result = 0;
1045                         try {
1046                                 bool done = false;
1047                                 if (!chunkedRead) {
1048                                         result = s.Read (buffer, offset, size);
1049                                         done = (result == 0);
1050                                 }
1051
1052                                 if (chunkedRead) {
1053                                         try {
1054                                                 chunkStream.WriteAndReadBack (buffer, offset, size, ref result);
1055                                                 if (!done && result == 0 && chunkStream.WantMore)
1056                                                         result = EnsureRead (buffer, offset, size);
1057                                         } catch (Exception e) {
1058                                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "chunked Read1");
1059                                                 throw;
1060                                         }
1061
1062                                         if ((done || result == 0) && chunkStream.WantMore) {
1063                                                 HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked Read2");
1064                                                 throw new WebException ("Read error", null, WebExceptionStatus.ReceiveFailure, null);
1065                                         }
1066                                 }
1067                         } catch (Exception e) {
1068                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "Read");
1069                         }
1070
1071                         return result;
1072                 }
1073
1074                 internal bool Write (HttpWebRequest request, byte [] buffer, int offset, int size, ref string err_msg)
1075                 {
1076                         err_msg = null;
1077                         Stream s = null;
1078                         lock (this) {
1079                                 if (Data.request != request)
1080                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1081                                 s = nstream;
1082                                 if (s == null)
1083                                         return false;
1084                         }
1085
1086                         try {
1087                                 s.Write (buffer, offset, size);
1088                         } catch (Exception e) {
1089                                 err_msg = e.Message;
1090                                 WebExceptionStatus wes = WebExceptionStatus.SendFailure;
1091                                 string msg = "Write: " + err_msg;
1092                                 if (e is WebException) {
1093                                         HandleError (wes, e, msg);
1094                                         return false;
1095                                 }
1096
1097                                 HandleError (wes, e, msg);
1098                                 return false;
1099                         }
1100                         return true;
1101                 }
1102
1103                 internal void Close (bool sendNext)
1104                 {
1105                         lock (this) {
1106                                 if (Data != null && Data.request != null && Data.request.ReuseConnection) {
1107                                         Data.request.ReuseConnection = false;
1108                                         return;
1109                                 }
1110
1111                                 if (nstream != null) {
1112                                         try {
1113                                                 nstream.Close ();
1114                                         } catch {}
1115                                         nstream = null;
1116                                 }
1117
1118                                 if (socket != null) {
1119                                         try {
1120                                                 socket.Close ();
1121                                         } catch {}
1122                                         socket = null;
1123                                 }
1124
1125                                 if (ntlm_authenticated)
1126                                         ResetNtlm ();
1127                                 if (Data != null) {
1128                                         lock (Data) {
1129                                                 Data.ReadState = ReadState.Aborted;
1130                                         }
1131                                 }
1132                                 state.SetIdle ();
1133                                 Data = new WebConnectionData ();
1134                                 if (sendNext)
1135                                         SendNext ();
1136
1137                                 connect_request = null;
1138                                 connect_ntlm_auth_state = NtlmAuthState.None;
1139                         }
1140                 }
1141
1142                 void Abort (object sender, EventArgs args)
1143                 {
1144                         lock (this) {
1145                                 lock (queue) {
1146                                         HttpWebRequest req = (HttpWebRequest) sender;
1147                                         if (Data.request == req || Data.request == null) {
1148                                                 if (!req.FinishedReading) {
1149                                                         status = WebExceptionStatus.RequestCanceled;
1150                                                         Close (false);
1151                                                         if (queue.Count > 0) {
1152                                                                 Data.request = (HttpWebRequest) queue.Dequeue ();
1153                                                                 SendRequest (Data.request);
1154                                                         }
1155                                                 }
1156                                                 return;
1157                                         }
1158
1159                                         req.FinishedReading = true;
1160                                         req.SetResponseError (WebExceptionStatus.RequestCanceled, null, "User aborted");
1161                                         if (queue.Count > 0 && queue.Peek () == sender) {
1162                                                 queue.Dequeue ();
1163                                         } else if (queue.Count > 0) {
1164                                                 object [] old = queue.ToArray ();
1165                                                 queue.Clear ();
1166                                                 for (int i = old.Length - 1; i >= 0; i--) {
1167                                                         if (old [i] != sender)
1168                                                                 queue.Enqueue (old [i]);
1169                                                 }
1170                                         }
1171                                 }
1172                         }
1173                 }
1174
1175                 internal void ResetNtlm ()
1176                 {
1177                         ntlm_authenticated = false;
1178                         ntlm_credentials = null;
1179                         unsafe_sharing = false;
1180                 }
1181
1182                 internal bool Connected {
1183                         get {
1184                                 lock (this) {
1185                                         return (socket != null && socket.Connected);
1186                                 }
1187                         }
1188                 }
1189
1190                 // -Used for NTLM authentication
1191                 internal HttpWebRequest PriorityRequest {
1192                         set { priority_request = value; }
1193                 }
1194
1195                 internal bool NtlmAuthenticated {
1196                         get { return ntlm_authenticated; }
1197                         set { ntlm_authenticated = value; }
1198                 }
1199
1200                 internal NetworkCredential NtlmCredential {
1201                         get { return ntlm_credentials; }
1202                         set { ntlm_credentials = value; }
1203                 }
1204
1205                 internal bool UnsafeAuthenticatedConnectionSharing {
1206                         get { return unsafe_sharing; }
1207                         set { unsafe_sharing = value; }
1208                 }
1209                 // -
1210         }
1211 }
1212