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                                 Data.Headers = result;
 297                                 return false;
 298                         } else if (status != 200) {
 299                                 string msg = String.Format ("The remote server returned a {0} status code.", status);
 300                                 HandleError (WebExceptionStatus.SecureChannelFailure, null, msg);
 301                                 return false;
 302                         }
 303
 304                         return (result != null);
 305                 }
 306
 307                 WebHeaderCollection ReadHeaders (Stream stream, out byte [] retBuffer, out int status)
 308                 {
 309                         retBuffer = null;
 310                         status = 200;
 311
 312                         byte [] buffer = new byte [1024];
 313                         MemoryStream ms = new MemoryStream ();
 314
 315                         while (true) {
 316                                 int n = stream.Read (buffer, 0, 1024);
 317                                 if (n == 0) {
 318                                         HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders");
 319                                         return null;
 320                                 }
 321
 322                                 ms.Write (buffer, 0, n);
 323                                 int start = 0;
 324                                 string str = null;
 325                                 bool gotStatus = false;
 326                                 WebHeaderCollection headers = new WebHeaderCollection ();
 327                                 while (ReadLine (ms.GetBuffer (), ref start, (int) ms.Length, ref str)) {
 328                                         if (str == null) {
 329                                                 int contentLen = 0;
 330                                                 try     {
 331                                                         contentLen = int.Parse(headers["Content-Length"]);
 332                                                 }
 333                                                 catch {
 334                                                         contentLen = 0;
 335                                                 }
 336
 337                                                 if (ms.Length - start - contentLen > 0) {
 338                                                         // we've read more data than the response header and conents,
 339                                                         // give back extra data to the caller
 340                                                         retBuffer = new byte[ms.Length - start - contentLen];
 341                                                         Buffer.BlockCopy(ms.GetBuffer(), start + contentLen, retBuffer, 0, retBuffer.Length);
 342                                                 }
 343                                                 else {
 344                                                         // haven't read in some or all of the contents for the response, do so now
 345                                                         FlushContents(stream, contentLen - (int)(ms.Length - start));
 346                                                 }
 347
 348                                                 return headers;
 349                                         }
 350
 351                                         if (gotStatus) {
 352                                                 headers.Add (str);
 353                                                 continue;
 354                                         }
 355
 356                                         string[] parts = str.Split (' ');
 357                                         if (parts.Length < 2) {
 358                                                 HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders2");
 359                                                 return null;
 360                                         }
 361
 362                                         if (String.Compare (parts [0], "HTTP/1.1", true) == 0)
 363                                                 Data.ProxyVersion = HttpVersion.Version11;
 364                                         else if (String.Compare (parts [0], "HTTP/1.0", true) == 0)
 365                                                 Data.ProxyVersion = HttpVersion.Version10;
 366                                         else {
 367                                                 HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders2");
 368                                                 return null;
 369                                         }
 370
 371                                         status = (int)UInt32.Parse (parts [1]);
 372                                         if (parts.Length >= 3)
 373                                                 Data.StatusDescription = String.Join (" ", parts, 2, parts.Length - 2);
 374
 375                                         gotStatus = true;
 376                                 }
 377                         }
 378                 }
 379
 380                 void FlushContents(Stream stream, int contentLength)
 381                 {
 382                         while (contentLength > 0) {
 383                                 byte[] contentBuffer = new byte[contentLength];
 384                                 int bytesRead = stream.Read(contentBuffer, 0, contentLength);
 385                                 if (bytesRead > 0) {
 386                                         contentLength -= bytesRead;
 387                                 }
 388                                 else {
 389                                         break;
 390                                 }
 391                         }
 392                 }
 393
 394                 bool CreateStream (HttpWebRequest request)
 395                 {
 396                         try {
 397                                 NetworkStream serverStream = new NetworkStream (socket, false);
 398
 399                                 if (request.Address.Scheme == Uri.UriSchemeHttps) {
 400 #if SECURITY_DEP
 401                                         if (!reused || nstream == null || tlsStream == null) {
 402                                                 byte [] buffer = null;
 403                                                 if (sPoint.UseConnect) {
 404                                                         bool ok = CreateTunnel (request, sPoint.Address, serverStream, out buffer);
 405                                                         if (!ok)
 406                                                                 return false;
 407                                                 }
 408                                                 tlsStream = new MonoTlsStream (request, serverStream);
 409                                                 nstream = tlsStream.CreateStream (buffer);
 410                                         }
 411                                         // we also need to set ServicePoint.Certificate
 412                                         // and ServicePoint.ClientCertificate but this can
 413                                         // only be done later (after handshake - which is
 414                                         // done only after a read operation).
 415 #else
 416                                         throw new NotSupportedException ();
 417 #endif
 418                                 } else {
 419                                         nstream = serverStream;
 420                                 }
 421                         } catch (Exception ex) {
 422                                 if (tlsStream != null)
 423                                         status = tlsStream.ExceptionStatus;
 424                                 else if (!request.Aborted)
 425                                         status = WebExceptionStatus.ConnectFailure;
 426                                 connect_exception = ex;
 427                                 return false;
 428                         }
 429
 430                         return true;
 431                 }
 432
 433                 void HandleError (WebExceptionStatus st, Exception e, string where)
 434                 {
 435                         status = st;
 436                         lock (this) {
 437                                 if (st == WebExceptionStatus.RequestCanceled)
 438                                         Data = new WebConnectionData ();
 439                         }
 440
 441                         if (e == null) { // At least we now where it comes from
 442                                 try {
 443                                         throw new Exception (new System.Diagnostics.StackTrace ().ToString ());
 444                                 } catch (Exception e2) {
 445                                         e = e2;
 446                                 }
 447                         }
 448
 449                         HttpWebRequest req = null;
 450                         if (Data != null && Data.request != null)
 451                                 req = Data.request;
 452
 453                         Close (true);
 454                         if (req != null) {
 455                                 req.FinishedReading = true;
 456                                 req.SetResponseError (st, e, where);
 457                         }
 458                 }
 459
 460                 static void ReadDone (IAsyncResult result)
 461                 {
 462                         WebConnection cnc = (WebConnection)result.AsyncState;
 463                         WebConnectionData data = cnc.Data;
 464                         Stream ns = cnc.nstream;
 465                         if (ns == null) {
 466                                 cnc.Close (true);
 467                                 return;
 468                         }
 469
 470                         int nread = -1;
 471                         try {
 472                                 nread = ns.EndRead (result);
 473                         } catch (ObjectDisposedException) {
 474                                 return;
 475                         } catch (Exception e) {
 476                                 if (e.InnerException is ObjectDisposedException)
 477                                         return;
 478
 479                                 cnc.HandleError (WebExceptionStatus.ReceiveFailure, e, "ReadDone1");
 480                                 return;
 481                         }
 482
 483                         if (nread == 0) {
 484                                 cnc.HandleError (WebExceptionStatus.ReceiveFailure, null, "ReadDone2");
 485                                 return;
 486                         }
 487
 488                         if (nread < 0) {
 489                                 cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadDone3");
 490                                 return;
 491                         }
 492
 493                         int pos = -1;
 494                         nread += cnc.position;
 495                         if (data.ReadState == ReadState.None) {
 496                                 Exception exc = null;
 497                                 try {
 498                                         pos = GetResponse (data, cnc.sPoint, cnc.buffer, nread);
 499                                 } catch (Exception e) {
 500                                         exc = e;
 501                                 }
 502
 503                                 if (exc != null || pos == -1) {
 504                                         cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, exc, "ReadDone4");
 505                                         return;
 506                                 }
 507                         }
 508
 509                         if (data.ReadState == ReadState.Aborted) {
 510                                 cnc.HandleError (WebExceptionStatus.RequestCanceled, null, "ReadDone");
 511                                 return;
 512                         }
 513
 514                         if (data.ReadState != ReadState.Content) {
 515                                 int est = nread * 2;
 516                                 int max = (est < cnc.buffer.Length) ? cnc.buffer.Length : est;
 517                                 byte [] newBuffer = new byte [max];
 518                                 Buffer.BlockCopy (cnc.buffer, 0, newBuffer, 0, nread);
 519                                 cnc.buffer = newBuffer;
 520                                 cnc.position = nread;
 521                                 data.ReadState = ReadState.None;
 522                                 InitRead (cnc);
 523                                 return;
 524                         }
 525
 526                         cnc.position = 0;
 527
 528                         WebConnectionStream stream = new WebConnectionStream (cnc, data);
 529                         bool expect_content = ExpectContent (data.StatusCode, data.request.Method);
 530                         string tencoding = null;
 531                         if (expect_content)
 532                                 tencoding = data.Headers ["Transfer-Encoding"];
 533
 534                         cnc.chunkedRead = (tencoding != null && tencoding.IndexOf ("chunked", StringComparison.OrdinalIgnoreCase) != -1);
 535                         if (!cnc.chunkedRead) {
 536                                 stream.ReadBuffer = cnc.buffer;
 537                                 stream.ReadBufferOffset = pos;
 538                                 stream.ReadBufferSize = nread;
 539                                 try {
 540                                         stream.CheckResponseInBuffer ();
 541                                 } catch (Exception e) {
 542                                         cnc.HandleError (WebExceptionStatus.ReceiveFailure, e, "ReadDone7");
 543                                 }
 544                         } else if (cnc.chunkStream == null) {
 545                                 try {
 546                                         cnc.chunkStream = new ChunkStream (cnc.buffer, pos, nread, data.Headers);
 547                                 } catch (Exception e) {
 548                                         cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, e, "ReadDone5");
 549                                         return;
 550                                 }
 551                         } else {
 552                                 cnc.chunkStream.ResetBuffer ();
 553                                 try {
 554                                         cnc.chunkStream.Write (cnc.buffer, pos, nread);
 555                                 } catch (Exception e) {
 556                                         cnc.HandleError (WebExceptionStatus.ServerProtocolViolation, e, "ReadDone6");
 557                                         return;
 558                                 }
 559                         }
 560
 561                         data.stream = stream;
 562
 563                         if (!expect_content)
 564                                 stream.ForceCompletion ();
 565
 566                         data.request.SetResponseData (data);
 567                 }
 568
 569                 static bool ExpectContent (int statusCode, string method)
 570                 {
 571                         if (method == "HEAD")
 572                                 return false;
 573                         return (statusCode >= 200 && statusCode != 204 && statusCode != 304);
 574                 }
 575
 576                 internal static void InitRead (object state)
 577                 {
 578                         WebConnection cnc = (WebConnection) state;
 579                         Stream ns = cnc.nstream;
 580
 581                         try {
 582                                 int size = cnc.buffer.Length - cnc.position;
 583                                 ns.BeginRead (cnc.buffer, cnc.position, size, readDoneDelegate, cnc);
 584                         } catch (Exception e) {
 585                                 cnc.HandleError (WebExceptionStatus.ReceiveFailure, e, "InitRead");
 586                         }
 587                 }
 588
 589                 static int GetResponse (WebConnectionData data, ServicePoint sPoint,
 590                                         byte [] buffer, int max)
 591                 {
 592                         int pos = 0;
 593                         string line = null;
 594                         bool lineok = false;
 595                         bool isContinue = false;
 596                         bool emptyFirstLine = false;
 597                         do {
 598                                 if (data.ReadState == ReadState.Aborted)
 599                                         return -1;
 600
 601                                 if (data.ReadState == ReadState.None) {
 602                                         lineok = ReadLine (buffer, ref pos, max, ref line);
 603                                         if (!lineok)
 604                                                 return 0;
 605
 606                                         if (line == null) {
 607                                                 emptyFirstLine = true;
 608                                                 continue;
 609                                         }
 610                                         emptyFirstLine = false;
 611                                         data.ReadState = ReadState.Status;
 612
 613                                         string [] parts = line.Split (' ');
 614                                         if (parts.Length < 2)
 615                                                 return -1;
 616
 617                                         if (String.Compare (parts [0], "HTTP/1.1", true) == 0) {
 618                                                 data.Version = HttpVersion.Version11;
 619                                                 sPoint.SetVersion (HttpVersion.Version11);
 620                                         } else {
 621                                                 data.Version = HttpVersion.Version10;
 622                                                 sPoint.SetVersion (HttpVersion.Version10);
 623                                         }
 624
 625                                         data.StatusCode = (int) UInt32.Parse (parts [1]);
 626                                         if (parts.Length >= 3)
 627                                                 data.StatusDescription = String.Join (" ", parts, 2, parts.Length - 2);
 628                                         else
 629                                                 data.StatusDescription = "";
 630
 631                                         if (pos >= max)
 632                                                 return pos;
 633                                 }
 634
 635                                 emptyFirstLine = false;
 636                                 if (data.ReadState == ReadState.Status) {
 637                                         data.ReadState = ReadState.Headers;
 638                                         data.Headers = new WebHeaderCollection ();
 639                                         ArrayList headers = new ArrayList ();
 640                                         bool finished = false;
 641                                         while (!finished) {
 642                                                 if (ReadLine (buffer, ref pos, max, ref line) == false)
 643                                                         break;
 644
 645                                                 if (line == null) {
 646                                                         // Empty line: end of headers
 647                                                         finished = true;
 648                                                         continue;
 649                                                 }
 650
 651                                                 if (line.Length > 0 && (line [0] == ' ' || line [0] == '\t')) {
 652                                                         int count = headers.Count - 1;
 653                                                         if (count < 0)
 654                                                                 break;
 655
 656                                                         string prev = (string) headers [count] + line;
 657                                                         headers [count] = prev;
 658                                                 } else {
 659                                                         headers.Add (line);
 660                                                 }
 661                                         }
 662
 663                                         if (!finished)
 664                                                 return 0;
 665
 666                                         // .NET uses ParseHeaders or ParseHeadersStrict which is much better
 667                                         foreach (string s in headers) {
 668
 669                                                 int pos_s = s.IndexOf (':');
 670                                                 if (pos_s == -1)
 671                                                         throw new ArgumentException ("no colon found", "header");
 672
 673                                                 var header = s.Substring (0, pos_s);
 674                                                 var value = s.Substring (pos_s + 1).Trim ();
 675
 676                                                 var h = data.Headers;
 677                                                 if (WebHeaderCollection.AllowMultiValues (header)) {
 678                                                         h.AddInternal (header, value);
 679                                                 } else  {
 680                                                         h.SetInternal (header, value);
 681                                                 }
 682                                         }
 683
 684                                         if (data.StatusCode == (int) HttpStatusCode.Continue) {
 685                                                 sPoint.SendContinue = true;
 686                                                 if (pos >= max)
 687                                                         return pos;
 688
 689                                                 if (data.request.ExpectContinue) {
 690                                                         data.request.DoContinueDelegate (data.StatusCode, data.Headers);
 691                                                         // Prevent double calls when getting the
 692                                                         // headers in several packets.
 693                                                         data.request.ExpectContinue = false;
 694                                                 }
 695
 696                                                 data.ReadState = ReadState.None;
 697                                                 isContinue = true;
 698                                         }
 699                                         else {
 700                                                 data.ReadState = ReadState.Content;
 701                                                 return pos;
 702                                         }
 703                                 }
 704                         } while (emptyFirstLine || isContinue);
 705
 706                         return -1;
 707                 }
 708
 709                 void InitConnection (object state)
 710                 {
 711                         HttpWebRequest request = (HttpWebRequest) state;
 712                         request.WebConnection = this;
 713                         if (request.ReuseConnection)
 714                                 request.StoredConnection = this;
 715
 716                         if (request.Aborted)
 717                                 return;
 718
 719                         keepAlive = request.KeepAlive;
 720                         Data = new WebConnectionData (request);
 721                 retry:
 722                         Connect (request);
 723                         if (request.Aborted)
 724                                 return;
 725
 726                         if (status != WebExceptionStatus.Success) {
 727                                 if (!request.Aborted) {
 728                                         request.SetWriteStreamError (status, connect_exception);
 729                                         Close (true);
 730                                 }
 731                                 return;
 732                         }
 733
 734                         if (!CreateStream (request)) {
 735                                 if (request.Aborted)
 736                                         return;
 737
 738                                 WebExceptionStatus st = status;
 739                                 if (Data.Challenge != null)
 740                                         goto retry;
 741
 742                                 Exception cnc_exc = connect_exception;
 743                                 if (cnc_exc == null && (Data.StatusCode == 401 || Data.StatusCode == 407)) {
 744                                         st = WebExceptionStatus.ProtocolError;
 745                                         if (Data.Headers == null)
 746                                                 Data.Headers = new WebHeaderCollection ();
 747
 748                                         var webResponse = new HttpWebResponse (sPoint.Address, "CONNECT", Data, null);
 749                                         cnc_exc = new WebException (Data.StatusCode == 407 ? "(407) Proxy Authentication Required" : "(401) Unauthorized", null, st, webResponse);
 750                                 }
 751
 752                                 connect_exception = null;
 753                                 request.SetWriteStreamError (st, cnc_exc);
 754                                 Close (true);
 755                                 return;
 756                         }
 757
 758                         request.SetWriteStream (new WebConnectionStream (this, request));
 759                 }
 760
 761 #if MONOTOUCH
 762                 static bool warned_about_queue = false;
 763 #endif
 764
 765                 internal EventHandler SendRequest (HttpWebRequest request)
 766                 {
 767                         if (request.Aborted)
 768                                 return null;
 769
 770                         lock (this) {
 771                                 if (state.TrySetBusy ()) {
 772                                         status = WebExceptionStatus.Success;
 773                                         ThreadPool.QueueUserWorkItem (initConn, request);
 774                                 } else {
 775                                         lock (queue) {
 776 #if MONOTOUCH
 777                                                 if (!warned_about_queue) {
 778                                                         warned_about_queue = true;
 779                                                         Console.WriteLine ("WARNING: An HttpWebRequest was added to the ConnectionGroup queue because the connection limit was reached.");
 780                                                 }
 781 #endif
 782                                                 queue.Enqueue (request);
 783                                         }
 784                                 }
 785                         }
 786
 787                         return abortHandler;
 788                 }
 789
 790                 void SendNext ()
 791                 {
 792                         lock (queue) {
 793                                 if (queue.Count > 0) {
 794                                         SendRequest ((HttpWebRequest) queue.Dequeue ());
 795                                 }
 796                         }
 797                 }
 798
 799                 internal void NextRead ()
 800                 {
 801                         lock (this) {
 802                                 if (Data.request != null)
 803                                         Data.request.FinishedReading = true;
 804                                 string header = (sPoint.UsesProxy) ? "Proxy-Connection" : "Connection";
 805                                 string cncHeader = (Data.Headers != null) ? Data.Headers [header] : null;
 806                                 bool keepAlive = (Data.Version == HttpVersion.Version11 && this.keepAlive);
 807                                 if (Data.ProxyVersion != null && Data.ProxyVersion != HttpVersion.Version11)
 808                                         keepAlive = false;
 809                                 if (cncHeader != null) {
 810                                         cncHeader = cncHeader.ToLower ();
 811                                         keepAlive = (this.keepAlive && cncHeader.IndexOf ("keep-alive", StringComparison.Ordinal) != -1);
 812                                 }
 813
 814                                 if ((socket != null && !socket.Connected) ||
 815                                    (!keepAlive || (cncHeader != null && cncHeader.IndexOf ("close", StringComparison.Ordinal) != -1))) {
 816                                         Close (false);
 817                                 }
 818
 819                                 state.SetIdle ();
 820                                 if (priority_request != null) {
 821                                         SendRequest (priority_request);
 822                                         priority_request = null;
 823                                 } else {
 824                                         SendNext ();
 825                                 }
 826                         }
 827                 }
 828
 829                 static bool ReadLine (byte [] buffer, ref int start, int max, ref string output)
 830                 {
 831                         bool foundCR = false;
 832                         StringBuilder text = new StringBuilder ();
 833
 834                         int c = 0;
 835                         while (start < max) {
 836                                 c = (int) buffer [start++];
 837
 838                                 if (c == '\n') {                        // newline
 839                                         if ((text.Length > 0) && (text [text.Length - 1] == '\r'))
 840                                                 text.Length--;
 841
 842                                         foundCR = false;
 843                                         break;
 844                                 } else if (foundCR) {
 845                                         text.Length--;
 846                                         break;
 847                                 }
 848
 849                                 if (c == '\r')
 850                                         foundCR = true;
 851
 852
 853                                 text.Append ((char) c);
 854                         }
 855
 856                         if (c != '\n' && c != '\r')
 857                                 return false;
 858
 859                         if (text.Length == 0) {
 860                                 output = null;
 861                                 return (c == '\n' || c == '\r');
 862                         }
 863
 864                         if (foundCR)
 865                                 text.Length--;
 866
 867                         output = text.ToString ();
 868                         return true;
 869                 }
 870
 871
 872                 internal IAsyncResult BeginRead (HttpWebRequest request, byte [] buffer, int offset, int size, AsyncCallback cb, object state)
 873                 {
 874                         Stream s = null;
 875                         lock (this) {
 876                                 if (Data.request != request)
 877                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 878                                 if (nstream == null)
 879                                         return null;
 880                                 s = nstream;
 881                         }
 882
 883                         IAsyncResult result = null;
 884                         if (!chunkedRead || (!chunkStream.DataAvailable && chunkStream.WantMore)) {
 885                                 try {
 886                                         result = s.BeginRead (buffer, offset, size, cb, state);
 887                                         cb = null;
 888                                 } catch (Exception) {
 889                                         HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked BeginRead");
 890                                         throw;
 891                                 }
 892                         }
 893
 894                         if (chunkedRead) {
 895                                 WebAsyncResult wr = new WebAsyncResult (cb, state, buffer, offset, size);
 896                                 wr.InnerAsyncResult = result;
 897                                 if (result == null) {
 898                                         // Will be completed from the data in ChunkStream
 899                                         wr.SetCompleted (true, (Exception) null);
 900                                         wr.DoCallback ();
 901                                 }
 902                                 return wr;
 903                         }
 904
 905                         return result;
 906                 }
 907
 908                 internal int EndRead (HttpWebRequest request, IAsyncResult result)
 909                 {
 910                         Stream s = null;
 911                         lock (this) {
 912                                 if (request.Aborted)
 913                                         throw new WebException ("Request aborted", WebExceptionStatus.RequestCanceled);
 914                                 if (Data.request != request)
 915                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 916                                 if (nstream == null)
 917                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 918                                 s = nstream;
 919                         }
 920
 921                         int nbytes = 0;
 922                         bool done = false;
 923                         WebAsyncResult wr = null;
 924                         IAsyncResult nsAsync = ((WebAsyncResult) result).InnerAsyncResult;
 925                         if (chunkedRead && (nsAsync is WebAsyncResult)) {
 926                                 wr = (WebAsyncResult) nsAsync;
 927                                 IAsyncResult inner = wr.InnerAsyncResult;
 928                                 if (inner != null && !(inner is WebAsyncResult)) {
 929                                         nbytes = s.EndRead (inner);
 930                                         done = nbytes == 0;
 931                                 }
 932                         } else if (!(nsAsync is WebAsyncResult)) {
 933                                 nbytes = s.EndRead (nsAsync);
 934                                 wr = (WebAsyncResult) result;
 935                                 done = nbytes == 0;
 936                         }
 937
 938                         if (chunkedRead) {
 939                                 try {
 940                                         chunkStream.WriteAndReadBack (wr.Buffer, wr.Offset, wr.Size, ref nbytes);
 941                                         if (!done && nbytes == 0 && chunkStream.WantMore)
 942                                                 nbytes = EnsureRead (wr.Buffer, wr.Offset, wr.Size);
 943                                 } catch (Exception e) {
 944                                         if (e is WebException)
 945                                                 throw e;
 946
 947                                         throw new WebException ("Invalid chunked data.", e,
 948                                                                 WebExceptionStatus.ServerProtocolViolation, null);
 949                                 }
 950
 951                                 if ((done || nbytes == 0) && chunkStream.ChunkLeft != 0) {
 952                                         HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked EndRead");
 953                                         throw new WebException ("Read error", null, WebExceptionStatus.ReceiveFailure, null);
 954                                 }
 955                         }
 956
 957                         return (nbytes != 0) ? nbytes : -1;
 958                 }
 959
 960                 // To be called on chunkedRead when we can read no data from the ChunkStream yet
 961                 int EnsureRead (byte [] buffer, int offset, int size)
 962                 {
 963                         byte [] morebytes = null;
 964                         int nbytes = 0;
 965                         while (nbytes == 0 && chunkStream.WantMore) {
 966                                 int localsize = chunkStream.ChunkLeft;
 967                                 if (localsize <= 0) // not read chunk size yet
 968                                         localsize = 1024;
 969                                 else if (localsize > 16384)
 970                                         localsize = 16384;
 971
 972                                 if (morebytes == null || morebytes.Length < localsize)
 973                                         morebytes = new byte [localsize];
 974
 975                                 int nread = nstream.Read (morebytes, 0, localsize);
 976                                 if (nread <= 0)
 977                                         return 0; // Error
 978
 979                                 chunkStream.Write (morebytes, 0, nread);
 980                                 nbytes += chunkStream.Read (buffer, offset + nbytes, size - nbytes);
 981                         }
 982
 983                         return nbytes;
 984                 }
 985
 986                 bool CompleteChunkedRead()
 987                 {
 988                         if (!chunkedRead || chunkStream == null)
 989                                 return true;
 990
 991                         while (chunkStream.WantMore) {
 992                                 int nbytes = nstream.Read (buffer, 0, buffer.Length);
 993                                 if (nbytes <= 0)
 994                                         return false; // Socket was disconnected
 995
 996                                 chunkStream.Write (buffer, 0, nbytes);
 997                         }
 998
 999                         return true;
1000                 }
1001
1002                 internal IAsyncResult BeginWrite (HttpWebRequest request, byte [] buffer, int offset, int size, AsyncCallback cb, object state)
1003                 {
1004                         Stream s = null;
1005                         lock (this) {
1006                                 if (Data.request != request)
1007                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1008                                 if (nstream == null)
1009                                         return null;
1010                                 s = nstream;
1011                         }
1012
1013                         IAsyncResult result = null;
1014                         try {
1015                                 result = s.BeginWrite (buffer, offset, size, cb, state);
1016                         } catch (Exception) {
1017                                 status = WebExceptionStatus.SendFailure;
1018                                 throw;
1019                         }
1020
1021                         return result;
1022                 }
1023
1024                 internal bool EndWrite (HttpWebRequest request, bool throwOnError, IAsyncResult result)
1025                 {
1026                         Stream s = null;
1027                         lock (this) {
1028                                 if (status == WebExceptionStatus.RequestCanceled)
1029                                         return true;
1030                                 if (Data.request != request)
1031                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1032                                 if (nstream == null)
1033                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1034                                 s = nstream;
1035                         }
1036
1037                         try {
1038                                 s.EndWrite (result);
1039                                 return true;
1040                         } catch (Exception exc) {
1041                                 status = WebExceptionStatus.SendFailure;
1042                                 if (throwOnError && exc.InnerException != null)
1043                                         throw exc.InnerException;
1044                                 return false;
1045                         }
1046                 }
1047
1048                 internal int Read (HttpWebRequest request, byte [] buffer, int offset, int size)
1049                 {
1050                         Stream s = null;
1051                         lock (this) {
1052                                 if (Data.request != request)
1053                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1054                                 if (nstream == null)
1055                                         return 0;
1056                                 s = nstream;
1057                         }
1058
1059                         int result = 0;
1060                         try {
1061                                 bool done = false;
1062                                 if (!chunkedRead) {
1063                                         result = s.Read (buffer, offset, size);
1064                                         done = (result == 0);
1065                                 }
1066
1067                                 if (chunkedRead) {
1068                                         try {
1069                                                 chunkStream.WriteAndReadBack (buffer, offset, size, ref result);
1070                                                 if (!done && result == 0 && chunkStream.WantMore)
1071                                                         result = EnsureRead (buffer, offset, size);
1072                                         } catch (Exception e) {
1073                                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "chunked Read1");
1074                                                 throw;
1075                                         }
1076
1077                                         if ((done || result == 0) && chunkStream.WantMore) {
1078                                                 HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked Read2");
1079                                                 throw new WebException ("Read error", null, WebExceptionStatus.ReceiveFailure, null);
1080                                         }
1081                                 }
1082                         } catch (Exception e) {
1083                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "Read");
1084                         }
1085
1086                         return result;
1087                 }
1088
1089                 internal bool Write (HttpWebRequest request, byte [] buffer, int offset, int size, ref string err_msg)
1090                 {
1091                         err_msg = null;
1092                         Stream s = null;
1093                         lock (this) {
1094                                 if (Data.request != request)
1095                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1096                                 s = nstream;
1097                                 if (s == null)
1098                                         return false;
1099                         }
1100
1101                         try {
1102                                 s.Write (buffer, offset, size);
1103                         } catch (Exception e) {
1104                                 err_msg = e.Message;
1105                                 WebExceptionStatus wes = WebExceptionStatus.SendFailure;
1106                                 string msg = "Write: " + err_msg;
1107                                 if (e is WebException) {
1108                                         HandleError (wes, e, msg);
1109                                         return false;
1110                                 }
1111
1112                                 HandleError (wes, e, msg);
1113                                 return false;
1114                         }
1115                         return true;
1116                 }
1117
1118                 internal void Close (bool sendNext)
1119                 {
1120                         lock (this) {
1121                                 if (Data != null && Data.request != null && Data.request.ReuseConnection) {
1122                                         Data.request.ReuseConnection = false;
1123                                         return;
1124                                 }
1125
1126                                 if (nstream != null) {
1127                                         try {
1128                                                 nstream.Close ();
1129                                         } catch {}
1130                                         nstream = null;
1131                                 }
1132
1133                                 if (socket != null) {
1134                                         try {
1135                                                 socket.Close ();
1136                                         } catch {}
1137                                         socket = null;
1138                                 }
1139
1140                                 if (ntlm_authenticated)
1141                                         ResetNtlm ();
1142                                 if (Data != null) {
1143                                         lock (Data) {
1144                                                 Data.ReadState = ReadState.Aborted;
1145                                         }
1146                                 }
1147                                 state.SetIdle ();
1148                                 Data = new WebConnectionData ();
1149                                 if (sendNext)
1150                                         SendNext ();
1151
1152                                 connect_request = null;
1153                                 connect_ntlm_auth_state = NtlmAuthState.None;
1154                         }
1155                 }
1156
1157                 void Abort (object sender, EventArgs args)
1158                 {
1159                         lock (this) {
1160                                 lock (queue) {
1161                                         HttpWebRequest req = (HttpWebRequest) sender;
1162                                         if (Data.request == req || Data.request == null) {
1163                                                 if (!req.FinishedReading) {
1164                                                         status = WebExceptionStatus.RequestCanceled;
1165                                                         Close (false);
1166                                                         if (queue.Count > 0) {
1167                                                                 Data.request = (HttpWebRequest) queue.Dequeue ();
1168                                                                 SendRequest (Data.request);
1169                                                         }
1170                                                 }
1171                                                 return;
1172                                         }
1173
1174                                         req.FinishedReading = true;
1175                                         req.SetResponseError (WebExceptionStatus.RequestCanceled, null, "User aborted");
1176                                         if (queue.Count > 0 && queue.Peek () == sender) {
1177                                                 queue.Dequeue ();
1178                                         } else if (queue.Count > 0) {
1179                                                 object [] old = queue.ToArray ();
1180                                                 queue.Clear ();
1181                                                 for (int i = old.Length - 1; i >= 0; i--) {
1182                                                         if (old [i] != sender)
1183                                                                 queue.Enqueue (old [i]);
1184                                                 }
1185                                         }
1186                                 }
1187                         }
1188                 }
1189
1190                 internal void ResetNtlm ()
1191                 {
1192                         ntlm_authenticated = false;
1193                         ntlm_credentials = null;
1194                         unsafe_sharing = false;
1195                 }
1196
1197                 internal bool Connected {
1198                         get {
1199                                 lock (this) {
1200                                         return (socket != null && socket.Connected);
1201                                 }
1202                         }
1203                 }
1204
1205                 // -Used for NTLM authentication
1206                 internal HttpWebRequest PriorityRequest {
1207                         set { priority_request = value; }
1208                 }
1209
1210                 internal bool NtlmAuthenticated {
1211                         get { return ntlm_authenticated; }
1212                         set { ntlm_authenticated = value; }
1213                 }
1214
1215                 internal NetworkCredential NtlmCredential {
1216                         get { return ntlm_credentials; }
1217                         set { ntlm_credentials = value; }
1218                 }
1219
1220                 internal bool UnsafeAuthenticatedConnectionSharing {
1221                         get { return unsafe_sharing; }
1222                         set { unsafe_sharing = value; }
1223                 }
1224                 // -
1225         }
1226 }
1227