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                 bool keepAlive;
  60                 byte [] buffer;
  61                 EventHandler abortHandler;
  62                 AbortHelper abortHelper;
  63                 internal WebConnectionData Data;
  64                 bool chunkedRead;
  65                 MonoChunkStream chunkStream;
  66                 Queue queue;
  67                 bool reused;
  68                 int position;
  69                 HttpWebRequest priority_request;
  70                 NetworkCredential ntlm_credentials;
  71                 bool ntlm_authenticated;
  72                 bool unsafe_sharing;
  73
  74                 enum NtlmAuthState
  75                 {
  76                         None,
  77                         Challenge,
  78                         Response
  79                 }
  80                 NtlmAuthState connect_ntlm_auth_state;
  81                 HttpWebRequest connect_request;
  82
  83                 Exception connect_exception;
  84                 MonoTlsStream tlsStream;
  85
  86 #if MONOTOUCH && !MONOTOUCH_TV && !MONOTOUCH_WATCH
  87                 [System.Runtime.InteropServices.DllImport ("__Internal")]
  88                 static extern void xamarin_start_wwan (string uri);
  89 #endif
  90
  91                 internal MonoChunkStream MonoChunkStream {
  92                         get { return chunkStream; }
  93                 }
  94
  95                 public WebConnection (IWebConnectionState wcs, ServicePoint sPoint)
  96                 {
  97                         this.state = wcs;
  98                         this.sPoint = sPoint;
  99                         buffer = new byte [4096];
 100                         Data = new WebConnectionData ();
 101                         queue = wcs.Group.Queue;
 102                         abortHelper = new AbortHelper ();
 103                         abortHelper.Connection = this;
 104                         abortHandler = new EventHandler (abortHelper.Abort);
 105                 }
 106
 107                 class AbortHelper {
 108                         public WebConnection Connection;
 109
 110                         public void Abort (object sender, EventArgs args)
 111                         {
 112                                 WebConnection other = ((HttpWebRequest) sender).WebConnection;
 113                                 if (other == null)
 114                                         other = Connection;
 115                                 other.Abort (sender, args);
 116                         }
 117                 }
 118
 119                 bool CanReuse ()
 120                 {
 121                         // The real condition is !(socket.Poll (0, SelectMode.SelectRead) || socket.Available != 0)
 122                         // but if there's data pending to read (!) we won't reuse the socket.
 123                         return (socket.Poll (0, SelectMode.SelectRead) == false);
 124                 }
 125
 126                 void Connect (HttpWebRequest request)
 127                 {
 128                         lock (socketLock) {
 129                                 if (socket != null && socket.Connected && status == WebExceptionStatus.Success) {
 130                                         // Take the chunked stream to the expected state (State.None)
 131                                         if (CanReuse () && CompleteChunkedRead ()) {
 132                                                 reused = true;
 133                                                 return;
 134                                         }
 135                                 }
 136
 137                                 reused = false;
 138                                 if (socket != null) {
 139                                         socket.Close();
 140                                         socket = null;
 141                                 }
 142
 143                                 chunkStream = null;
 144                                 IPHostEntry hostEntry = sPoint.HostEntry;
 145
 146                                 if (hostEntry == null) {
 147 #if MONOTOUCH && !MONOTOUCH_TV && !MONOTOUCH_WATCH
 148                                         xamarin_start_wwan (sPoint.Address.ToString ());
 149                                         hostEntry = sPoint.HostEntry;
 150                                         if (hostEntry == null) {
 151 #endif
 152                                                 status = sPoint.UsesProxy ? WebExceptionStatus.ProxyNameResolutionFailure :
 153                                                                             WebExceptionStatus.NameResolutionFailure;
 154                                                 return;
 155 #if MONOTOUCH && !MONOTOUCH_TV && !MONOTOUCH_WATCH
 156                                         }
 157 #endif
 158                                 }
 159
 160                                 //WebConnectionData data = Data;
 161                                 foreach (IPAddress address in hostEntry.AddressList) {
 162                                         try {
 163                                                 socket = new Socket (address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
 164                                         } catch (Exception se) {
 165                                                 // The Socket ctor can throw if we run out of FD's
 166                                                 if (!request.Aborted)
 167                                                                 status = WebExceptionStatus.ConnectFailure;
 168                                                 connect_exception = se;
 169                                                 return;
 170                                         }
 171                                         IPEndPoint remote = new IPEndPoint (address, sPoint.Address.Port);
 172                                         socket.NoDelay = !sPoint.UseNagleAlgorithm;
 173                                         try {
 174                                                 sPoint.KeepAliveSetup (socket);
 175                                         } catch {
 176                                                 // Ignore. Not supported in all platforms.
 177                                         }
 178
 179                                         if (!sPoint.CallEndPointDelegate (socket, remote)) {
 180                                                 socket.Close ();
 181                                                 socket = null;
 182                                                 status = WebExceptionStatus.ConnectFailure;
 183                                         } else {
 184                                                 try {
 185                                                         if (request.Aborted)
 186                                                                 return;
 187                                                         socket.Connect (remote);
 188                                                         status = WebExceptionStatus.Success;
 189                                                         break;
 190                                                 } catch (ThreadAbortException) {
 191                                                         // program exiting...
 192                                                         Socket s = socket;
 193                                                         socket = null;
 194                                                         if (s != null)
 195                                                                 s.Close ();
 196                                                         return;
 197                                                 } catch (ObjectDisposedException) {
 198                                                         // socket closed from another thread
 199                                                         return;
 200                                                 } catch (Exception exc) {
 201                                                         Socket s = socket;
 202                                                         socket = null;
 203                                                         if (s != null)
 204                                                                 s.Close ();
 205                                                         if (!request.Aborted)
 206                                                                 status = WebExceptionStatus.ConnectFailure;
 207                                                         connect_exception = exc;
 208                                                 }
 209                                         }
 210                                 }
 211                         }
 212                 }
 213
 214                 bool CreateTunnel (HttpWebRequest request, Uri connectUri,
 215                                    Stream stream, out byte[] buffer)
 216                 {
 217                         StringBuilder sb = new StringBuilder ();
 218                         sb.Append ("CONNECT ");
 219                         sb.Append (request.Address.Host);
 220                         sb.Append (':');
 221                         sb.Append (request.Address.Port);
 222                         sb.Append (" HTTP/");
 223                         if (request.ServicePoint.ProtocolVersion == HttpVersion.Version11)
 224                                 sb.Append ("1.1");
 225                         else
 226                                 sb.Append ("1.0");
 227
 228                         sb.Append ("\r\nHost: ");
 229                         sb.Append (request.Address.Authority);
 230
 231                         bool ntlm = false;
 232                         var challenge = Data.Challenge;
 233                         Data.Challenge = null;
 234                         var auth_header = request.Headers ["Proxy-Authorization"];
 235                         bool have_auth = auth_header != null;
 236                         if (have_auth) {
 237                                 sb.Append ("\r\nProxy-Authorization: ");
 238                                 sb.Append (auth_header);
 239                                 ntlm = auth_header.ToUpper ().Contains ("NTLM");
 240                         } else if (challenge != null && Data.StatusCode == 407) {
 241                                 ICredentials creds = request.Proxy.Credentials;
 242                                 have_auth = true;
 243
 244                                 if (connect_request == null) {
 245                                         // create a CONNECT request to use with Authenticate
 246                                         connect_request = (HttpWebRequest)WebRequest.Create (
 247                                                 connectUri.Scheme + "://" + connectUri.Host + ":" + connectUri.Port + "/");
 248                                         connect_request.Method = "CONNECT";
 249                                         connect_request.Credentials = creds;
 250                                 }
 251
 252                                 if (creds != null) {
 253                                         for (int i = 0; i < challenge.Length; i++) {
 254                                                 var auth = AuthenticationManager.Authenticate (challenge [i], connect_request, creds);
 255                                                 if (auth == null)
 256                                                         continue;
 257                                                 ntlm = (auth.ModuleAuthenticationType == "NTLM");
 258                                                 sb.Append ("\r\nProxy-Authorization: ");
 259                                                 sb.Append (auth.Message);
 260                                                 break;
 261                                         }
 262                                 }
 263                         }
 264
 265                         if (ntlm) {
 266                                 sb.Append ("\r\nProxy-Connection: keep-alive");
 267                                 connect_ntlm_auth_state++;
 268                         }
 269
 270                         sb.Append ("\r\n\r\n");
 271
 272                         Data.StatusCode = 0;
 273                         byte [] connectBytes = Encoding.Default.GetBytes (sb.ToString ());
 274                         stream.Write (connectBytes, 0, connectBytes.Length);
 275
 276                         int status;
 277                         WebHeaderCollection result = ReadHeaders (stream, out buffer, out status);
 278                         if ((!have_auth || connect_ntlm_auth_state == NtlmAuthState.Challenge) &&
 279                             result != null && status == 407) { // Needs proxy auth
 280                                 var connectionHeader = result ["Connection"];
 281                                 if (socket != null && !string.IsNullOrEmpty (connectionHeader) &&
 282                                     connectionHeader.ToLower() == "close") {
 283                                         // The server is requesting that this connection be closed
 284                                         socket.Close();
 285                                         socket = null;
 286                                 }
 287
 288                                 Data.StatusCode = status;
 289                                 Data.Challenge = result.GetValues ("Proxy-Authenticate");
 290                                 Data.Headers = result;
 291                                 return false;
 292                         }
 293
 294                         if (status != 200) {
 295                                 Data.StatusCode = status;
 296                                 Data.Headers = result;
 297                                 return false;
 298                         }
 299
 300                         return (result != null);
 301                 }
 302
 303                 WebHeaderCollection ReadHeaders (Stream stream, out byte [] retBuffer, out int status)
 304                 {
 305                         retBuffer = null;
 306                         status = 200;
 307
 308                         byte [] buffer = new byte [1024];
 309                         MemoryStream ms = new MemoryStream ();
 310
 311                         while (true) {
 312                                 int n = stream.Read (buffer, 0, 1024);
 313                                 if (n == 0) {
 314                                         HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders");
 315                                         return null;
 316                                 }
 317
 318                                 ms.Write (buffer, 0, n);
 319                                 int start = 0;
 320                                 string str = null;
 321                                 bool gotStatus = false;
 322                                 WebHeaderCollection headers = new WebHeaderCollection ();
 323                                 while (ReadLine (ms.GetBuffer (), ref start, (int) ms.Length, ref str)) {
 324                                         if (str == null) {
 325                                                 int contentLen = 0;
 326                                                 try     {
 327                                                         contentLen = int.Parse(headers["Content-Length"]);
 328                                                 }
 329                                                 catch {
 330                                                         contentLen = 0;
 331                                                 }
 332
 333                                                 if (ms.Length - start - contentLen > 0) {
 334                                                         // we've read more data than the response header and conents,
 335                                                         // give back extra data to the caller
 336                                                         retBuffer = new byte[ms.Length - start - contentLen];
 337                                                         Buffer.BlockCopy(ms.GetBuffer(), start + contentLen, retBuffer, 0, retBuffer.Length);
 338                                                 }
 339                                                 else {
 340                                                         // haven't read in some or all of the contents for the response, do so now
 341                                                         FlushContents(stream, contentLen - (int)(ms.Length - start));
 342                                                 }
 343
 344                                                 return headers;
 345                                         }
 346
 347                                         if (gotStatus) {
 348                                                 headers.Add (str);
 349                                                 continue;
 350                                         }
 351
 352                                         string[] parts = str.Split (' ');
 353                                         if (parts.Length < 2) {
 354                                                 HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders2");
 355                                                 return null;
 356                                         }
 357
 358                                         if (String.Compare (parts [0], "HTTP/1.1", true) == 0)
 359                                                 Data.ProxyVersion = HttpVersion.Version11;
 360                                         else if (String.Compare (parts [0], "HTTP/1.0", true) == 0)
 361                                                 Data.ProxyVersion = HttpVersion.Version10;
 362                                         else {
 363                                                 HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadHeaders2");
 364                                                 return null;
 365                                         }
 366
 367                                         status = (int)UInt32.Parse (parts [1]);
 368                                         if (parts.Length >= 3)
 369                                                 Data.StatusDescription = String.Join (" ", parts, 2, parts.Length - 2);
 370
 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                 void ReadDone (IAsyncResult result)
 457                 {
 458                         WebConnectionData data = Data;
 459                         Stream ns = nstream;
 460                         if (ns == null) {
 461                                 Close (true);
 462                                 return;
 463                         }
 464
 465                         int nread = -1;
 466                         try {
 467                                 nread = ns.EndRead (result);
 468                         } catch (ObjectDisposedException) {
 469                                 return;
 470                         } catch (Exception e) {
 471                                 if (e.InnerException is ObjectDisposedException)
 472                                         return;
 473
 474                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "ReadDone1");
 475                                 return;
 476                         }
 477
 478                         if (nread == 0) {
 479                                 HandleError (WebExceptionStatus.ReceiveFailure, null, "ReadDone2");
 480                                 return;
 481                         }
 482
 483                         if (nread < 0) {
 484                                 HandleError (WebExceptionStatus.ServerProtocolViolation, null, "ReadDone3");
 485                                 return;
 486                         }
 487
 488                         int pos = -1;
 489                         nread += position;
 490                         if (data.ReadState == ReadState.None) {
 491                                 Exception exc = null;
 492                                 try {
 493                                         pos = GetResponse (data, sPoint, buffer, nread);
 494                                 } catch (Exception e) {
 495                                         exc = e;
 496                                 }
 497
 498                                 if (exc != null || pos == -1) {
 499                                         HandleError (WebExceptionStatus.ServerProtocolViolation, exc, "ReadDone4");
 500                                         return;
 501                                 }
 502                         }
 503
 504                         if (data.ReadState == ReadState.Aborted) {
 505                                 HandleError (WebExceptionStatus.RequestCanceled, null, "ReadDone");
 506                                 return;
 507                         }
 508
 509                         if (data.ReadState != ReadState.Content) {
 510                                 int est = nread * 2;
 511                                 int max = (est < buffer.Length) ? buffer.Length : est;
 512                                 byte [] newBuffer = new byte [max];
 513                                 Buffer.BlockCopy (buffer, 0, newBuffer, 0, nread);
 514                                 buffer = newBuffer;
 515                                 position = nread;
 516                                 data.ReadState = ReadState.None;
 517                                 InitRead ();
 518                                 return;
 519                         }
 520
 521                         position = 0;
 522
 523                         WebConnectionStream stream = new WebConnectionStream (this, data);
 524                         bool expect_content = ExpectContent (data.StatusCode, data.request.Method);
 525                         string tencoding = null;
 526                         if (expect_content)
 527                                 tencoding = data.Headers ["Transfer-Encoding"];
 528
 529                         chunkedRead = (tencoding != null && tencoding.IndexOf ("chunked", StringComparison.OrdinalIgnoreCase) != -1);
 530                         if (!chunkedRead) {
 531                                 stream.ReadBuffer = buffer;
 532                                 stream.ReadBufferOffset = pos;
 533                                 stream.ReadBufferSize = nread;
 534                                 try {
 535                                         stream.CheckResponseInBuffer ();
 536                                 } catch (Exception e) {
 537                                         HandleError (WebExceptionStatus.ReceiveFailure, e, "ReadDone7");
 538                                 }
 539                         } else if (chunkStream == null) {
 540                                 try {
 541                                         chunkStream = new MonoChunkStream (buffer, pos, nread, data.Headers);
 542                                 } catch (Exception e) {
 543                                         HandleError (WebExceptionStatus.ServerProtocolViolation, e, "ReadDone5");
 544                                         return;
 545                                 }
 546                         } else {
 547                                 chunkStream.ResetBuffer ();
 548                                 try {
 549                                         chunkStream.Write (buffer, pos, nread);
 550                                 } catch (Exception e) {
 551                                         HandleError (WebExceptionStatus.ServerProtocolViolation, e, "ReadDone6");
 552                                         return;
 553                                 }
 554                         }
 555
 556                         data.stream = stream;
 557
 558                         if (!expect_content)
 559                                 stream.ForceCompletion ();
 560
 561                         data.request.SetResponseData (data);
 562                 }
 563
 564                 static bool ExpectContent (int statusCode, string method)
 565                 {
 566                         if (method == "HEAD")
 567                                 return false;
 568                         return (statusCode >= 200 && statusCode != 204 && statusCode != 304);
 569                 }
 570
 571                 internal void InitRead ()
 572                 {
 573                         Stream ns = nstream;
 574
 575                         try {
 576                                 int size = buffer.Length - position;
 577                                 ns.BeginRead (buffer, position, size, ReadDone, null);
 578                         } catch (Exception e) {
 579                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "InitRead");
 580                         }
 581                 }
 582
 583                 static int GetResponse (WebConnectionData data, ServicePoint sPoint,
 584                                         byte [] buffer, int max)
 585                 {
 586                         int pos = 0;
 587                         string line = null;
 588                         bool lineok = false;
 589                         bool isContinue = false;
 590                         bool emptyFirstLine = false;
 591                         do {
 592                                 if (data.ReadState == ReadState.Aborted)
 593                                         return -1;
 594
 595                                 if (data.ReadState == ReadState.None) {
 596                                         lineok = ReadLine (buffer, ref pos, max, ref line);
 597                                         if (!lineok)
 598                                                 return 0;
 599
 600                                         if (line == null) {
 601                                                 emptyFirstLine = true;
 602                                                 continue;
 603                                         }
 604                                         emptyFirstLine = false;
 605                                         data.ReadState = ReadState.Status;
 606
 607                                         string [] parts = line.Split (' ');
 608                                         if (parts.Length < 2)
 609                                                 return -1;
 610
 611                                         if (String.Compare (parts [0], "HTTP/1.1", true) == 0) {
 612                                                 data.Version = HttpVersion.Version11;
 613                                                 sPoint.SetVersion (HttpVersion.Version11);
 614                                         } else {
 615                                                 data.Version = HttpVersion.Version10;
 616                                                 sPoint.SetVersion (HttpVersion.Version10);
 617                                         }
 618
 619                                         data.StatusCode = (int) UInt32.Parse (parts [1]);
 620                                         if (parts.Length >= 3)
 621                                                 data.StatusDescription = String.Join (" ", parts, 2, parts.Length - 2);
 622                                         else
 623                                                 data.StatusDescription = "";
 624
 625                                         if (pos >= max)
 626                                                 return pos;
 627                                 }
 628
 629                                 emptyFirstLine = false;
 630                                 if (data.ReadState == ReadState.Status) {
 631                                         data.ReadState = ReadState.Headers;
 632                                         data.Headers = new WebHeaderCollection ();
 633                                         ArrayList headers = new ArrayList ();
 634                                         bool finished = false;
 635                                         while (!finished) {
 636                                                 if (ReadLine (buffer, ref pos, max, ref line) == false)
 637                                                         break;
 638
 639                                                 if (line == null) {
 640                                                         // Empty line: end of headers
 641                                                         finished = true;
 642                                                         continue;
 643                                                 }
 644
 645                                                 if (line.Length > 0 && (line [0] == ' ' || line [0] == '\t')) {
 646                                                         int count = headers.Count - 1;
 647                                                         if (count < 0)
 648                                                                 break;
 649
 650                                                         string prev = (string) headers [count] + line;
 651                                                         headers [count] = prev;
 652                                                 } else {
 653                                                         headers.Add (line);
 654                                                 }
 655                                         }
 656
 657                                         if (!finished)
 658                                                 return 0;
 659
 660                                         // .NET uses ParseHeaders or ParseHeadersStrict which is much better
 661                                         foreach (string s in headers) {
 662
 663                                                 int pos_s = s.IndexOf (':');
 664                                                 if (pos_s == -1)
 665                                                         throw new ArgumentException ("no colon found", "header");
 666
 667                                                 var header = s.Substring (0, pos_s);
 668                                                 var value = s.Substring (pos_s + 1).Trim ();
 669
 670                                                 var h = data.Headers;
 671                                                 if (WebHeaderCollection.AllowMultiValues (header)) {
 672                                                         h.AddInternal (header, value);
 673                                                 } else  {
 674                                                         h.SetInternal (header, value);
 675                                                 }
 676                                         }
 677
 678                                         if (data.StatusCode == (int) HttpStatusCode.Continue) {
 679                                                 sPoint.SendContinue = true;
 680                                                 if (pos >= max)
 681                                                         return pos;
 682
 683                                                 if (data.request.ExpectContinue) {
 684                                                         data.request.DoContinueDelegate (data.StatusCode, data.Headers);
 685                                                         // Prevent double calls when getting the
 686                                                         // headers in several packets.
 687                                                         data.request.ExpectContinue = false;
 688                                                 }
 689
 690                                                 data.ReadState = ReadState.None;
 691                                                 isContinue = true;
 692                                         }
 693                                         else {
 694                                                 data.ReadState = ReadState.Content;
 695                                                 return pos;
 696                                         }
 697                                 }
 698                         } while (emptyFirstLine || isContinue);
 699
 700                         return -1;
 701                 }
 702
 703                 void InitConnection (HttpWebRequest request)
 704                 {
 705                         request.WebConnection = this;
 706                         if (request.ReuseConnection)
 707                                 request.StoredConnection = this;
 708
 709                         if (request.Aborted)
 710                                 return;
 711
 712                         keepAlive = request.KeepAlive;
 713                         Data = new WebConnectionData (request);
 714                 retry:
 715                         Connect (request);
 716                         if (request.Aborted)
 717                                 return;
 718
 719                         if (status != WebExceptionStatus.Success) {
 720                                 if (!request.Aborted) {
 721                                         request.SetWriteStreamError (status, connect_exception);
 722                                         Close (true);
 723                                 }
 724                                 return;
 725                         }
 726
 727                         if (!CreateStream (request)) {
 728                                 if (request.Aborted)
 729                                         return;
 730
 731                                 WebExceptionStatus st = status;
 732                                 if (Data.Challenge != null)
 733                                         goto retry;
 734
 735                                 Exception cnc_exc = connect_exception;
 736                                 if (cnc_exc == null && (Data.StatusCode == 401 || Data.StatusCode == 407)) {
 737                                         st = WebExceptionStatus.ProtocolError;
 738                                         if (Data.Headers == null)
 739                                                 Data.Headers = new WebHeaderCollection ();
 740
 741                                         var webResponse = new HttpWebResponse (sPoint.Address, "CONNECT", Data, null);
 742                                         cnc_exc = new WebException (Data.StatusCode == 407 ? "(407) Proxy Authentication Required" : "(401) Unauthorized", null, st, webResponse);
 743                                 }
 744
 745                                 connect_exception = null;
 746                                 request.SetWriteStreamError (st, cnc_exc);
 747                                 Close (true);
 748                                 return;
 749                         }
 750
 751                         request.SetWriteStream (new WebConnectionStream (this, request));
 752                 }
 753
 754 #if MONOTOUCH
 755                 static bool warned_about_queue = false;
 756 #endif
 757
 758                 internal EventHandler SendRequest (HttpWebRequest request)
 759                 {
 760                         if (request.Aborted)
 761                                 return null;
 762
 763                         lock (this) {
 764                                 if (state.TrySetBusy ()) {
 765                                         status = WebExceptionStatus.Success;
 766                                         ThreadPool.QueueUserWorkItem (o => { try { InitConnection ((HttpWebRequest) o); } catch {} }, request);
 767                                 } else {
 768                                         lock (queue) {
 769 #if MONOTOUCH
 770                                                 if (!warned_about_queue) {
 771                                                         warned_about_queue = true;
 772                                                         Console.WriteLine ("WARNING: An HttpWebRequest was added to the ConnectionGroup queue because the connection limit was reached.");
 773                                                 }
 774 #endif
 775                                                 queue.Enqueue (request);
 776                                         }
 777                                 }
 778                         }
 779
 780                         return abortHandler;
 781                 }
 782
 783                 void SendNext ()
 784                 {
 785                         lock (queue) {
 786                                 if (queue.Count > 0) {
 787                                         SendRequest ((HttpWebRequest) queue.Dequeue ());
 788                                 }
 789                         }
 790                 }
 791
 792                 internal void NextRead ()
 793                 {
 794                         lock (this) {
 795                                 if (Data.request != null)
 796                                         Data.request.FinishedReading = true;
 797                                 string header = (sPoint.UsesProxy) ? "Proxy-Connection" : "Connection";
 798                                 string cncHeader = (Data.Headers != null) ? Data.Headers [header] : null;
 799                                 bool keepAlive = (Data.Version == HttpVersion.Version11 && this.keepAlive);
 800                                 if (Data.ProxyVersion != null && Data.ProxyVersion != HttpVersion.Version11)
 801                                         keepAlive = false;
 802                                 if (cncHeader != null) {
 803                                         cncHeader = cncHeader.ToLower ();
 804                                         keepAlive = (this.keepAlive && cncHeader.IndexOf ("keep-alive", StringComparison.Ordinal) != -1);
 805                                 }
 806
 807                                 if ((socket != null && !socket.Connected) ||
 808                                    (!keepAlive || (cncHeader != null && cncHeader.IndexOf ("close", StringComparison.Ordinal) != -1))) {
 809                                         Close (false);
 810                                 }
 811
 812                                 state.SetIdle ();
 813                                 if (priority_request != null) {
 814                                         SendRequest (priority_request);
 815                                         priority_request = null;
 816                                 } else {
 817                                         SendNext ();
 818                                 }
 819                         }
 820                 }
 821
 822                 static bool ReadLine (byte [] buffer, ref int start, int max, ref string output)
 823                 {
 824                         bool foundCR = false;
 825                         StringBuilder text = new StringBuilder ();
 826
 827                         int c = 0;
 828                         while (start < max) {
 829                                 c = (int) buffer [start++];
 830
 831                                 if (c == '\n') {                        // newline
 832                                         if ((text.Length > 0) && (text [text.Length - 1] == '\r'))
 833                                                 text.Length--;
 834
 835                                         foundCR = false;
 836                                         break;
 837                                 } else if (foundCR) {
 838                                         text.Length--;
 839                                         break;
 840                                 }
 841
 842                                 if (c == '\r')
 843                                         foundCR = true;
 844
 845
 846                                 text.Append ((char) c);
 847                         }
 848
 849                         if (c != '\n' && c != '\r')
 850                                 return false;
 851
 852                         if (text.Length == 0) {
 853                                 output = null;
 854                                 return (c == '\n' || c == '\r');
 855                         }
 856
 857                         if (foundCR)
 858                                 text.Length--;
 859
 860                         output = text.ToString ();
 861                         return true;
 862                 }
 863
 864
 865                 internal IAsyncResult BeginRead (HttpWebRequest request, byte [] buffer, int offset, int size, AsyncCallback cb, object state)
 866                 {
 867                         Stream s = null;
 868                         lock (this) {
 869                                 if (Data.request != request)
 870                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 871                                 if (nstream == null)
 872                                         return null;
 873                                 s = nstream;
 874                         }
 875
 876                         IAsyncResult result = null;
 877                         if (!chunkedRead || (!chunkStream.DataAvailable && chunkStream.WantMore)) {
 878                                 try {
 879                                         result = s.BeginRead (buffer, offset, size, cb, state);
 880                                         cb = null;
 881                                 } catch (Exception) {
 882                                         HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked BeginRead");
 883                                         throw;
 884                                 }
 885                         }
 886
 887                         if (chunkedRead) {
 888                                 WebAsyncResult wr = new WebAsyncResult (cb, state, buffer, offset, size);
 889                                 wr.InnerAsyncResult = result;
 890                                 if (result == null) {
 891                                         // Will be completed from the data in MonoChunkStream
 892                                         wr.SetCompleted (true, (Exception) null);
 893                                         wr.DoCallback ();
 894                                 }
 895                                 return wr;
 896                         }
 897
 898                         return result;
 899                 }
 900
 901                 internal int EndRead (HttpWebRequest request, IAsyncResult result)
 902                 {
 903                         Stream s = null;
 904                         lock (this) {
 905                                 if (request.Aborted)
 906                                         throw new WebException ("Request aborted", WebExceptionStatus.RequestCanceled);
 907                                 if (Data.request != request)
 908                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 909                                 if (nstream == null)
 910                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
 911                                 s = nstream;
 912                         }
 913
 914                         int nbytes = 0;
 915                         bool done = false;
 916                         WebAsyncResult wr = null;
 917                         IAsyncResult nsAsync = ((WebAsyncResult) result).InnerAsyncResult;
 918                         if (chunkedRead && (nsAsync is WebAsyncResult)) {
 919                                 wr = (WebAsyncResult) nsAsync;
 920                                 IAsyncResult inner = wr.InnerAsyncResult;
 921                                 if (inner != null && !(inner is WebAsyncResult)) {
 922                                         nbytes = s.EndRead (inner);
 923                                         done = nbytes == 0;
 924                                 }
 925                         } else if (!(nsAsync is WebAsyncResult)) {
 926                                 nbytes = s.EndRead (nsAsync);
 927                                 wr = (WebAsyncResult) result;
 928                                 done = nbytes == 0;
 929                         }
 930
 931                         if (chunkedRead) {
 932                                 try {
 933                                         chunkStream.WriteAndReadBack (wr.Buffer, wr.Offset, wr.Size, ref nbytes);
 934                                         if (!done && nbytes == 0 && chunkStream.WantMore)
 935                                                 nbytes = EnsureRead (wr.Buffer, wr.Offset, wr.Size);
 936                                 } catch (Exception e) {
 937                                         if (e is WebException)
 938                                                 throw e;
 939
 940                                         throw new WebException ("Invalid chunked data.", e,
 941                                                                 WebExceptionStatus.ServerProtocolViolation, null);
 942                                 }
 943
 944                                 if ((done || nbytes == 0) && chunkStream.ChunkLeft != 0) {
 945                                         HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked EndRead");
 946                                         throw new WebException ("Read error", null, WebExceptionStatus.ReceiveFailure, null);
 947                                 }
 948                         }
 949
 950                         return (nbytes != 0) ? nbytes : -1;
 951                 }
 952
 953                 // To be called on chunkedRead when we can read no data from the MonoChunkStream yet
 954                 int EnsureRead (byte [] buffer, int offset, int size)
 955                 {
 956                         byte [] morebytes = null;
 957                         int nbytes = 0;
 958                         while (nbytes == 0 && chunkStream.WantMore) {
 959                                 int localsize = chunkStream.ChunkLeft;
 960                                 if (localsize <= 0) // not read chunk size yet
 961                                         localsize = 1024;
 962                                 else if (localsize > 16384)
 963                                         localsize = 16384;
 964
 965                                 if (morebytes == null || morebytes.Length < localsize)
 966                                         morebytes = new byte [localsize];
 967
 968                                 int nread = nstream.Read (morebytes, 0, localsize);
 969                                 if (nread <= 0)
 970                                         return 0; // Error
 971
 972                                 chunkStream.Write (morebytes, 0, nread);
 973                                 nbytes += chunkStream.Read (buffer, offset + nbytes, size - nbytes);
 974                         }
 975
 976                         return nbytes;
 977                 }
 978
 979                 bool CompleteChunkedRead()
 980                 {
 981                         if (!chunkedRead || chunkStream == null)
 982                                 return true;
 983
 984                         while (chunkStream.WantMore) {
 985                                 int nbytes = nstream.Read (buffer, 0, buffer.Length);
 986                                 if (nbytes <= 0)
 987                                         return false; // Socket was disconnected
 988
 989                                 chunkStream.Write (buffer, 0, nbytes);
 990                         }
 991
 992                         return true;
 993                 }
 994
 995                 internal IAsyncResult BeginWrite (HttpWebRequest request, byte [] buffer, int offset, int size, AsyncCallback cb, object state)
 996                 {
 997                         Stream s = null;
 998                         lock (this) {
 999                                 if (Data.request != request)
1000                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1001                                 if (nstream == null)
1002                                         return null;
1003                                 s = nstream;
1004                         }
1005
1006                         IAsyncResult result = null;
1007                         try {
1008                                 result = s.BeginWrite (buffer, offset, size, cb, state);
1009                         } catch (ObjectDisposedException) {
1010                                 lock (this) {
1011                                         if (Data.request != request)
1012                                                 return null;
1013                                 }
1014                                 throw;
1015                         } catch (IOException e) {
1016                                 SocketException se = e.InnerException as SocketException;
1017                                 if (se != null && se.SocketErrorCode == SocketError.NotConnected) {
1018                                         return null;
1019                                 }
1020                                 throw;
1021                         } catch (Exception) {
1022                                 status = WebExceptionStatus.SendFailure;
1023                                 throw;
1024                         }
1025
1026                         return result;
1027                 }
1028
1029                 internal bool EndWrite (HttpWebRequest request, bool throwOnError, IAsyncResult result)
1030                 {
1031                         Stream s = null;
1032                         lock (this) {
1033                                 if (status == WebExceptionStatus.RequestCanceled)
1034                                         return true;
1035                                 if (Data.request != request)
1036                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1037                                 if (nstream == null)
1038                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1039                                 s = nstream;
1040                         }
1041
1042                         try {
1043                                 s.EndWrite (result);
1044                                 return true;
1045                         } catch (Exception exc) {
1046                                 status = WebExceptionStatus.SendFailure;
1047                                 if (throwOnError && exc.InnerException != null)
1048                                         throw exc.InnerException;
1049                                 return false;
1050                         }
1051                 }
1052
1053                 internal int Read (HttpWebRequest request, byte [] buffer, int offset, int size)
1054                 {
1055                         Stream s = null;
1056                         lock (this) {
1057                                 if (Data.request != request)
1058                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1059                                 if (nstream == null)
1060                                         return 0;
1061                                 s = nstream;
1062                         }
1063
1064                         int result = 0;
1065                         try {
1066                                 bool done = false;
1067                                 if (!chunkedRead) {
1068                                         result = s.Read (buffer, offset, size);
1069                                         done = (result == 0);
1070                                 }
1071
1072                                 if (chunkedRead) {
1073                                         try {
1074                                                 chunkStream.WriteAndReadBack (buffer, offset, size, ref result);
1075                                                 if (!done && result == 0 && chunkStream.WantMore)
1076                                                         result = EnsureRead (buffer, offset, size);
1077                                         } catch (Exception e) {
1078                                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "chunked Read1");
1079                                                 throw;
1080                                         }
1081
1082                                         if ((done || result == 0) && chunkStream.WantMore) {
1083                                                 HandleError (WebExceptionStatus.ReceiveFailure, null, "chunked Read2");
1084                                                 throw new WebException ("Read error", null, WebExceptionStatus.ReceiveFailure, null);
1085                                         }
1086                                 }
1087                         } catch (Exception e) {
1088                                 HandleError (WebExceptionStatus.ReceiveFailure, e, "Read");
1089                         }
1090
1091                         return result;
1092                 }
1093
1094                 internal bool Write (HttpWebRequest request, byte [] buffer, int offset, int size, ref string err_msg)
1095                 {
1096                         err_msg = null;
1097                         Stream s = null;
1098                         lock (this) {
1099                                 if (Data.request != request)
1100                                         throw new ObjectDisposedException (typeof (NetworkStream).FullName);
1101                                 s = nstream;
1102                                 if (s == null)
1103                                         return false;
1104                         }
1105
1106                         try {
1107                                 s.Write (buffer, offset, size);
1108                         } catch (Exception e) {
1109                                 err_msg = e.Message;
1110                                 WebExceptionStatus wes = WebExceptionStatus.SendFailure;
1111                                 string msg = "Write: " + err_msg;
1112                                 if (e is WebException) {
1113                                         HandleError (wes, e, msg);
1114                                         return false;
1115                                 }
1116
1117                                 HandleError (wes, e, msg);
1118                                 return false;
1119                         }
1120                         return true;
1121                 }
1122
1123                 internal void Close (bool sendNext)
1124                 {
1125                         lock (this) {
1126                                 if (Data != null && Data.request != null && Data.request.ReuseConnection) {
1127                                         Data.request.ReuseConnection = false;
1128                                         return;
1129                                 }
1130
1131                                 if (nstream != null) {
1132                                         try {
1133                                                 nstream.Close ();
1134                                         } catch {}
1135                                         nstream = null;
1136                                 }
1137
1138                                 if (socket != null) {
1139                                         try {
1140                                                 socket.Close ();
1141                                         } catch {}
1142                                         socket = null;
1143                                 }
1144
1145                                 if (ntlm_authenticated)
1146                                         ResetNtlm ();
1147                                 if (Data != null) {
1148                                         lock (Data) {
1149                                                 Data.ReadState = ReadState.Aborted;
1150                                         }
1151                                 }
1152                                 state.SetIdle ();
1153                                 Data = new WebConnectionData ();
1154                                 if (sendNext)
1155                                         SendNext ();
1156
1157                                 connect_request = null;
1158                                 connect_ntlm_auth_state = NtlmAuthState.None;
1159                         }
1160                 }
1161
1162                 void Abort (object sender, EventArgs args)
1163                 {
1164                         lock (this) {
1165                                 lock (queue) {
1166                                         HttpWebRequest req = (HttpWebRequest) sender;
1167                                         if (Data.request == req || Data.request == null) {
1168                                                 if (!req.FinishedReading) {
1169                                                         status = WebExceptionStatus.RequestCanceled;
1170                                                         Close (false);
1171                                                         if (queue.Count > 0) {
1172                                                                 Data.request = (HttpWebRequest) queue.Dequeue ();
1173                                                                 SendRequest (Data.request);
1174                                                         }
1175                                                 }
1176                                                 return;
1177                                         }
1178
1179                                         req.FinishedReading = true;
1180                                         req.SetResponseError (WebExceptionStatus.RequestCanceled, null, "User aborted");
1181                                         if (queue.Count > 0 && queue.Peek () == sender) {
1182                                                 queue.Dequeue ();
1183                                         } else if (queue.Count > 0) {
1184                                                 object [] old = queue.ToArray ();
1185                                                 queue.Clear ();
1186                                                 for (int i = old.Length - 1; i >= 0; i--) {
1187                                                         if (old [i] != sender)
1188                                                                 queue.Enqueue (old [i]);
1189                                                 }
1190                                         }
1191                                 }
1192                         }
1193                 }
1194
1195                 internal void ResetNtlm ()
1196                 {
1197                         ntlm_authenticated = false;
1198                         ntlm_credentials = null;
1199                         unsafe_sharing = false;
1200                 }
1201
1202                 internal bool Connected {
1203                         get {
1204                                 lock (this) {
1205                                         return (socket != null && socket.Connected);
1206                                 }
1207                         }
1208                 }
1209
1210                 // -Used for NTLM authentication
1211                 internal HttpWebRequest PriorityRequest {
1212                         set { priority_request = value; }
1213                 }
1214
1215                 internal bool NtlmAuthenticated {
1216                         get { return ntlm_authenticated; }
1217                         set { ntlm_authenticated = value; }
1218                 }
1219
1220                 internal NetworkCredential NtlmCredential {
1221                         get { return ntlm_credentials; }
1222                         set { ntlm_credentials = value; }
1223                 }
1224
1225                 internal bool UnsafeAuthenticatedConnectionSharing {
1226                         get { return unsafe_sharing; }
1227                         set { unsafe_sharing = value; }
1228                 }
1229                 // -
1230         }
1231 }
1232