summaryrefslogtreecommitdiff
path: root/methods/basehttp.cc
blob: f79f26a7c4b3bad7e1d05cc19c3985613fd9dd82 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
/* ######################################################################

   HTTP and HTTPS share a lot of common code and these classes are
   exactly the dumping ground for this common code

   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#include <config.h>

#include <apt-pkg/configuration.h>
#include <apt-pkg/error.h>
#include <apt-pkg/fileutl.h>
#include <apt-pkg/strutl.h>

#include <ctype.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <iostream>
#include <limits>
#include <map>
#include <string>
#include <vector>

#include "basehttp.h"

#include <apti18n.h>
									/*}}}*/
using namespace std;

string BaseHttpMethod::FailFile;
int BaseHttpMethod::FailFd = -1;
time_t BaseHttpMethod::FailTime = 0;

// ServerState::RunHeaders - Get the headers before the data		/*{{{*/
// ---------------------------------------------------------------------
/* Returns 0 if things are OK, 1 if an IO error occurred and 2 if a header
   parse error occurred */
ServerState::RunHeadersResult ServerState::RunHeaders(RequestState &Req,
                                                      const std::string &Uri)
{
   Owner->Status(_("Waiting for headers"));
   do
   {
      string Data;
      if (ReadHeaderLines(Data) == false)
	 continue;

      if (Owner->Debug == true)
	 clog << "Answer for: " << Uri << endl << Data;

      for (string::const_iterator I = Data.begin(); I < Data.end(); ++I)
      {
	 string::const_iterator J = I;
	 for (; J != Data.end() && *J != '\n' && *J != '\r'; ++J);
	 if (Req.HeaderLine(string(I,J)) == false)
	    return RUN_HEADERS_PARSE_ERROR;
	 I = J;
      }

      // 100 Continue is a Nop...
      if (Req.Result == 100)
	 continue;
      
      // Tidy up the connection persistence state.
      if (Req.Encoding == RequestState::Closes && Req.HaveContent == true)
	 Persistent = false;
      
      return RUN_HEADERS_OK;
   }
   while (LoadNextResponse(false, Req) == true);
   
   return RUN_HEADERS_IO_ERROR;
}
									/*}}}*/
bool RequestState::HeaderLine(string const &Line)			/*{{{*/
{
   if (Line.empty() == true)
      return true;

   if (Line.size() > 4 && stringcasecmp(Line.data(), Line.data()+4, "HTTP") == 0)
   {
      // Evil servers return no version
      if (Line[4] == '/')
      {
	 int const elements = sscanf(Line.c_str(),"HTTP/%3u.%3u %3u%359[^\n]",&Major,&Minor,&Result,Code);
	 if (elements == 3)
	 {
	    Code[0] = '\0';
	    if (Owner != NULL && Owner->Debug == true)
	       clog << "HTTP server doesn't give Reason-Phrase for " << std::to_string(Result) << std::endl;
	 }
	 else if (elements != 4)
	    return _error->Error(_("The HTTP server sent an invalid reply header"));
      }
      else
      {
	 Major = 0;
	 Minor = 9;
	 if (sscanf(Line.c_str(),"HTTP %3u%359[^\n]",&Result,Code) != 2)
	    return _error->Error(_("The HTTP server sent an invalid reply header"));
      }

      /* Check the HTTP response header to get the default persistence
         state. */
      if (Major < 1)
	 Server->Persistent = false;
      else
      {
	 if (Major == 1 && Minor == 0)
	 {
	    Server->Persistent = false;
	 }
	 else
	 {
	    Server->Persistent = true;
	    if (Server->PipelineAllowed)
	       Server->Pipeline = true;
	 }
      }

      return true;
   }

   // Blah, some servers use "connection:closes", evil.
   // and some even send empty header fields…
   string::size_type Pos = Line.find(':');
   if (Pos == string::npos)
      return _error->Error(_("Bad header line"));
   ++Pos;

   // Parse off any trailing spaces between the : and the next word.
   string::size_type Pos2 = Pos;
   while (Pos2 < Line.length() && isspace_ascii(Line[Pos2]) != 0)
      Pos2++;

   string const Tag(Line,0,Pos);
   string const Val(Line,Pos2);

   if (stringcasecmp(Tag,"Content-Length:") == 0)
   {
      auto ContentLength = strtoull(Val.c_str(), NULL, 10);
      if (ContentLength == 0)
	 return true;
      if (Encoding == Closes)
	 Encoding = Stream;
      HaveContent = true;

      unsigned long long * DownloadSizePtr = &DownloadSize;
      if (Result == 416 || (Result >= 300 && Result < 400))
	 DownloadSizePtr = &JunkSize;

      *DownloadSizePtr = ContentLength;
      if (*DownloadSizePtr >= std::numeric_limits<unsigned long long>::max())
	 return _error->Errno("HeaderLine", _("The HTTP server sent an invalid Content-Length header"));
      else if (*DownloadSizePtr == 0)
	 HaveContent = false;

      // On partial content (206) the Content-Length less than the real
      // size, so do not set it here but leave that to the Content-Range
      // header instead
      if(Result != 206 && TotalFileSize == 0)
         TotalFileSize = DownloadSize;

      return true;
   }

   if (stringcasecmp(Tag,"Content-Type:") == 0)
   {
      HaveContent = true;
      return true;
   }

   // The Content-Range field only has a meaning in HTTP/1.1 for the
   // 206 (Partial Content) and 416 (Range Not Satisfiable) responses
   // according to RFC7233 "Range Requests", §4.2, so only consider it
   // for such responses.
   if ((Result == 416 || Result == 206) && stringcasecmp(Tag,"Content-Range:") == 0)
   {
      HaveContent = true;

      // §14.16 says 'byte-range-resp-spec' should be a '*' in case of 416
      if (Result == 416 && sscanf(Val.c_str(), "bytes */%llu",&TotalFileSize) == 1)
	 ; // we got the expected filesize which is all we wanted
      else if (sscanf(Val.c_str(),"bytes %llu-%*u/%llu",&StartPos,&TotalFileSize) != 2)
	 return _error->Error(_("The HTTP server sent an invalid Content-Range header"));
      if ((unsigned long long)StartPos > TotalFileSize)
	 return _error->Error(_("This HTTP server has broken range support"));

      // figure out what we will download
      DownloadSize = TotalFileSize - StartPos;
      return true;
   }

   if (stringcasecmp(Tag,"Transfer-Encoding:") == 0)
   {
      HaveContent = true;
      if (stringcasecmp(Val,"chunked") == 0)
	 Encoding = Chunked;
      return true;
   }

   if (stringcasecmp(Tag,"Connection:") == 0)
   {
      if (stringcasecmp(Val,"close") == 0)
      {
	 Server->Persistent = false;
	 Server->Pipeline = false;
	 /* Some servers send error pages (as they are dynamically generated)
	    for simplicity via a connection close instead of e.g. chunked,
	    so assuming an always closing server only if we get a file + close */
	 if (Result >= 200 && Result < 300)
	    Server->PipelineAllowed = false;
      }
      else if (stringcasecmp(Val,"keep-alive") == 0)
	 Server->Persistent = true;
      return true;
   }

   if (stringcasecmp(Tag,"Last-Modified:") == 0)
   {
      if (RFC1123StrToTime(Val.c_str(), Date) == false)
	 return _error->Error(_("Unknown date format"));
      return true;
   }

   if (stringcasecmp(Tag,"Location:") == 0)
   {
      Location = Val;
      return true;
   }

   if (stringcasecmp(Tag, "Accept-Ranges:") == 0)
   {
      std::string ranges = ',' + Val + ',';
      ranges.erase(std::remove(ranges.begin(), ranges.end(), ' '), ranges.end());
      if (ranges.find(",bytes,") == std::string::npos)
	 Server->RangesAllowed = false;
      return true;
   }

   return true;
}
									/*}}}*/
// ServerState::ServerState - Constructor				/*{{{*/
ServerState::ServerState(URI Srv, BaseHttpMethod *Owner) :
   ServerName(Srv), TimeOut(120), Owner(Owner)
{
   Reset();
}
									/*}}}*/
bool RequestState::AddPartialFileToHashes(FileFd &File)			/*{{{*/
{
   File.Truncate(StartPos);
   return Server->GetHashes()->AddFD(File, StartPos);
}
									/*}}}*/
void ServerState::Reset()						/*{{{*/
{
   Persistent = false;
   Pipeline = false;
   PipelineAllowed = true;
   RangesAllowed = true;
}
									/*}}}*/

// BaseHttpMethod::DealWithHeaders - Handle the retrieved header data	/*{{{*/
// ---------------------------------------------------------------------
/* We look at the header data we got back from the server and decide what
   to do. Returns DealWithHeadersResult (see http.h for details).
 */
BaseHttpMethod::DealWithHeadersResult
BaseHttpMethod::DealWithHeaders(FetchResult &Res, RequestState &Req)
{
   // Not Modified
   if (Req.Result == 304)
   {
      RemoveFile("server", Queue->DestFile);
      Res.IMSHit = true;
      Res.LastModified = Queue->LastModified;
      Res.Size = 0;
      return IMS_HIT;
   }

   /* Redirect
    *
    * Note that it is only OK for us to treat all redirection the same
    * because we *always* use GET, not other HTTP methods.  There are
    * three redirection codes for which it is not appropriate that we
    * redirect.  Pass on those codes so the error handling kicks in.
    */
   if (AllowRedirect
       && (Req.Result > 300 && Req.Result < 400)
       && (Req.Result != 300       // Multiple Choices
           && Req.Result != 304    // Not Modified
           && Req.Result != 306))  // (Not part of HTTP/1.1, reserved)
   {
      if (Req.Location.empty() == true)
	 ;
      else if (Req.Location[0] == '/' && Queue->Uri.empty() == false)
      {
	 URI Uri = Queue->Uri;
	 if (Uri.Host.empty() == false)
            NextURI = URI::SiteOnly(Uri);
	 else
	    NextURI.clear();
	 NextURI.append(DeQuoteString(Req.Location));
	 if (Queue->Uri == NextURI)
	 {
	    SetFailReason("RedirectionLoop");
	    _error->Error("Redirection loop encountered");
	    if (Req.HaveContent == true)
	       return ERROR_WITH_CONTENT_PAGE;
	    return ERROR_UNRECOVERABLE;
	 }
	 return TRY_AGAIN_OR_REDIRECT;
      }
      else
      {
	 NextURI = DeQuoteString(Req.Location);
	 URI tmpURI = NextURI;
	 if (tmpURI.Access.find('+') != std::string::npos)
	 {
	    _error->Error("Server tried to trick us into using a specific implementation: %s", tmpURI.Access.c_str());
	    if (Req.HaveContent == true)
	       return ERROR_WITH_CONTENT_PAGE;
	    return ERROR_UNRECOVERABLE;
	 }
	 URI Uri = Queue->Uri;
	 if (Binary.find('+') != std::string::npos)
	 {
	    auto base = Binary.substr(0, Binary.find('+'));
	    if (base != tmpURI.Access)
	    {
	       tmpURI.Access = base + '+' + tmpURI.Access;
	       if (tmpURI.Access == Binary)
	       {
		  std::string tmpAccess = Uri.Access;
		  std::swap(tmpURI.Access, Uri.Access);
		  NextURI = tmpURI;
		  std::swap(tmpURI.Access, Uri.Access);
	       }
	       else
		  NextURI = tmpURI;
	    }
	 }
	 if (Queue->Uri == NextURI)
	 {
	    SetFailReason("RedirectionLoop");
	    _error->Error("Redirection loop encountered");
	    if (Req.HaveContent == true)
	       return ERROR_WITH_CONTENT_PAGE;
	    return ERROR_UNRECOVERABLE;
	 }
	 Uri.Access = Binary;
	 // same protocol redirects are okay
	 if (tmpURI.Access == Uri.Access)
	    return TRY_AGAIN_OR_REDIRECT;
	 // as well as http to https
	 else if ((Uri.Access == "http" || Uri.Access == "https+http") && tmpURI.Access == "https")
	    return TRY_AGAIN_OR_REDIRECT;
	 else
	 {
	    auto const tmpplus = tmpURI.Access.find('+');
	    if (tmpplus != std::string::npos && tmpURI.Access.substr(tmpplus + 1) == "https")
	    {
	       auto const uriplus = Uri.Access.find('+');
	       if (uriplus == std::string::npos)
	       {
		  if (Uri.Access == tmpURI.Access.substr(0, tmpplus)) // foo -> foo+https
		     return TRY_AGAIN_OR_REDIRECT;
	       }
	       else if (Uri.Access.substr(uriplus + 1) == "http" &&
		     Uri.Access.substr(0, uriplus) == tmpURI.Access.substr(0, tmpplus)) // foo+http -> foo+https
		  return TRY_AGAIN_OR_REDIRECT;
	    }
	 }
	 _error->Error("Redirection from %s to '%s' is forbidden", Uri.Access.c_str(), NextURI.c_str());
      }
      /* else pass through for error message */
   }
   // retry after an invalid range response without partial data
   else if (Req.Result == 416)
   {
      struct stat SBuf;
      if (stat(Queue->DestFile.c_str(),&SBuf) >= 0 && SBuf.st_size > 0)
      {
	 bool partialHit = false;
	 if (Queue->ExpectedHashes.usable() == true)
	 {
	    Hashes resultHashes(Queue->ExpectedHashes);
	    FileFd file(Queue->DestFile, FileFd::ReadOnly);
	    Req.TotalFileSize = file.FileSize();
	    Req.Date = file.ModificationTime();
	    resultHashes.AddFD(file);
	    HashStringList const hashList = resultHashes.GetHashStringList();
	    partialHit = (Queue->ExpectedHashes == hashList);
	 }
	 else if ((unsigned long long)SBuf.st_size == Req.TotalFileSize)
	    partialHit = true;
	 if (partialHit == true)
	 {
	    // the file is completely downloaded, but was not moved
	    if (Req.HaveContent == true)
	    {
	       // nuke the sent error page
	       Server->RunDataToDevNull(Req);
	       Req.HaveContent = false;
	    }
	    Req.StartPos = Req.TotalFileSize;
	    Req.Result = 200;
	 }
	 else if (RemoveFile("server", Queue->DestFile))
	 {
	    NextURI = Queue->Uri;
	    return TRY_AGAIN_OR_REDIRECT;
	 }
      }
   }

   /* We have a reply we don't handle. This should indicate a perm server
      failure */
   if (Req.Result < 200 || Req.Result >= 300)
   {
      if (_error->PendingError() == false)
      {
	 std::string err;
	 strprintf(err, "HttpError%u", Req.Result);
	 SetFailReason(err);
	 _error->Error("%u %s", Req.Result, Req.Code);
      }
      if (Req.HaveContent == true)
	 return ERROR_WITH_CONTENT_PAGE;
      return ERROR_UNRECOVERABLE;
   }

   // This is some sort of 2xx 'data follows' reply
   Res.LastModified = Req.Date;
   Res.Size = Req.TotalFileSize;
   return FILE_IS_OPEN;
}
									/*}}}*/
// BaseHttpMethod::SigTerm - Handle a fatal signal			/*{{{*/
// ---------------------------------------------------------------------
/* This closes and timestamps the open file. This is necessary to get
   resume behavior on user abort */
void BaseHttpMethod::SigTerm(int)
{
   if (FailFd == -1)
      _exit(100);

   struct timeval times[2];
   times[0].tv_sec = FailTime;
   times[1].tv_sec = FailTime;
   times[0].tv_usec = times[1].tv_usec = 0;
   utimes(FailFile.c_str(), times);
   close(FailFd);

   _exit(100);
}
									/*}}}*/
// BaseHttpMethod::Fetch - Fetch an item					/*{{{*/
// ---------------------------------------------------------------------
/* This adds an item to the pipeline. We keep the pipeline at a fixed
   depth. */
bool BaseHttpMethod::Fetch(FetchItem *)
{
   if (Server == nullptr || QueueBack == nullptr)
      return true;

   // If pipelining is disabled, we only queue 1 request
   auto const AllowedDepth = Server->Pipeline ? PipelineDepth : 0;
   // how deep is our pipeline currently?
   decltype(PipelineDepth) CurrentDepth = 0;
   for (FetchItem const *I = Queue; I != QueueBack; I = I->Next)
      ++CurrentDepth;
   if (CurrentDepth > AllowedDepth)
      return true;

   do {
      // Make sure we stick with the same server
      if (Server->Comp(QueueBack->Uri) == false)
	 break;

      bool const UsableHashes = QueueBack->ExpectedHashes.usable();
      // if we have no hashes, do at most one such request
      // as we can't fixup pipeling misbehaviors otherwise
      if (CurrentDepth != 0 && UsableHashes == false)
	 break;

      if (UsableHashes && FileExists(QueueBack->DestFile))
      {
	 FileFd partial(QueueBack->DestFile, FileFd::ReadOnly);
	 Hashes wehave(QueueBack->ExpectedHashes);
	 if (QueueBack->ExpectedHashes.FileSize() == partial.FileSize())
	 {
	    if (wehave.AddFD(partial) &&
		  wehave.GetHashStringList() == QueueBack->ExpectedHashes)
	    {
	       FetchResult Res;
	       Res.Filename = QueueBack->DestFile;
	       Res.ResumePoint = QueueBack->ExpectedHashes.FileSize();
	       URIStart(Res);
	       // move item to the start of the queue as URIDone will
	       // always dequeued the first item in the queue
	       if (Queue != QueueBack)
	       {
		  FetchItem *Prev = Queue;
		  for (; Prev->Next != QueueBack; Prev = Prev->Next)
		     /* look for the previous queue item */;
		  Prev->Next = QueueBack->Next;
		  QueueBack->Next = Queue;
		  Queue = QueueBack;
		  QueueBack = Prev->Next;
	       }
	       Res.TakeHashes(wehave);
	       URIDone(Res);
	       continue;
	    }
	    else
	       RemoveFile("Fetch-Partial", QueueBack->DestFile);
	 }
      }
      auto const Tmp = QueueBack;
      QueueBack = QueueBack->Next;
      SendReq(Tmp);
      ++CurrentDepth;
   } while (CurrentDepth <= AllowedDepth && QueueBack != nullptr);

   return true;
}
									/*}}}*/
// BaseHttpMethod::Loop - Main loop					/*{{{*/
int BaseHttpMethod::Loop()
{
   signal(SIGTERM,SigTerm);
   signal(SIGINT,SigTerm);
   
   Server = 0;
   
   int FailCounter = 0;
   while (1)
   {      
      // We have no commands, wait for some to arrive
      if (Queue == 0)
      {
	 if (WaitFd(STDIN_FILENO) == false)
	    return 0;
      }
      
      /* Run messages, we can accept 0 (no message) if we didn't
         do a WaitFd above.. Otherwise the FD is closed. */
      int Result = Run(true);
      if (Result != -1 && (Result != 0 || Queue == 0))
      {
	 if(FailReason.empty() == false ||
	    ConfigFindB("DependOnSTDIN", true) == true)
	    return 100;
	 else
	    return 0;
      }

      if (Queue == 0)
	 continue;
      
      // Connect to the server
      if (Server == 0 || Server->Comp(Queue->Uri) == false)
      {
	 Server = CreateServerState(Queue->Uri);
	 setPostfixForMethodNames(::URI(Queue->Uri).Host.c_str());
	 AllowRedirect = ConfigFindB("AllowRedirect", true);
	 PipelineDepth = ConfigFindI("Pipeline-Depth", 10);
	 Debug = DebugEnabled();
      }

      /* If the server has explicitly said this is the last connection
         then we pre-emptively shut down the pipeline and tear down 
	 the connection. This will speed up HTTP/1.0 servers a tad
	 since we don't have to wait for the close sequence to
         complete */
      if (Server->Persistent == false)
	 Server->Close();

      // Reset the pipeline
      if (Server->IsOpen() == false)
	 QueueBack = Queue;

      // Connect to the host
      if (Server->Open() == false)
      {
	 Fail(true);
	 Server = nullptr;
	 continue;
      }

      // Fill the pipeline.
      Fetch(0);

      RequestState Req(this, Server.get());
      // Fetch the next URL header data from the server.
      switch (Server->RunHeaders(Req, Queue->Uri))
      {
	 case ServerState::RUN_HEADERS_OK:
	 break;
	 
	 // The header data is bad
	 case ServerState::RUN_HEADERS_PARSE_ERROR:
	 {
	    _error->Error(_("Bad header data"));
	    Fail(true);
	    Server->Close();
	    RotateDNS();
	    continue;
	 }
	 
	 // The server closed a connection during the header get..
	 default:
	 case ServerState::RUN_HEADERS_IO_ERROR:
	 {
	    FailCounter++;
	    _error->Discard();
	    Server->Close();
	    Server->Pipeline = false;
	    Server->PipelineAllowed = false;
	    
	    if (FailCounter >= 2)
	    {
	       Fail(_("Connection failed"),true);
	       FailCounter = 0;
	    }
	    
	    RotateDNS();
	    continue;
	 }
      };

      // Decide what to do.
      FetchResult Res;
      Res.Filename = Queue->DestFile;
      switch (DealWithHeaders(Res, Req))
      {
	 // Ok, the file is Open
	 case FILE_IS_OPEN:
	 {
	    URIStart(Res);

	    // Run the data
	    bool Result = true;

            // ensure we don't fetch too much
            // we could do "Server->MaximumSize = Queue->MaximumSize" here
            // but that would break the clever pipeline messup detection
            // so instead we use the size of the biggest item in the queue
            Req.MaximumSize = FindMaximumObjectSizeInQueue();

            if (Req.HaveContent)
	       Result = Server->RunData(Req);

	    /* If the server is sending back sizeless responses then fill in
	       the size now */
	    if (Res.Size == 0)
	       Res.Size = Req.File.Size();

	    // Close the file, destroy the FD object and timestamp it
	    FailFd = -1;
	    Req.File.Close();

	    // Timestamp
	    struct timeval times[2];
	    times[0].tv_sec = times[1].tv_sec = Req.Date;
	    times[0].tv_usec = times[1].tv_usec = 0;
	    utimes(Queue->DestFile.c_str(), times);

	    // Send status to APT
	    if (Result == true)
	    {
	       Hashes * const resultHashes = Server->GetHashes();
	       HashStringList const hashList = resultHashes->GetHashStringList();
	       if (PipelineDepth != 0 && Queue->ExpectedHashes.usable() == true && Queue->ExpectedHashes != hashList)
	       {
		  // we did not get the expected hash… mhhh:
		  // could it be that server/proxy messed up pipelining?
		  FetchItem * BeforeI = Queue;
		  for (FetchItem *I = Queue->Next; I != 0 && I != QueueBack; I = I->Next)
		  {
		     if (I->ExpectedHashes.usable() == true && I->ExpectedHashes == hashList)
		     {
			// yes, he did! Disable pipelining and rewrite queue
			if (Server->Pipeline == true)
			{
			   Warning(_("Automatically disabled %s due to incorrect response from server/proxy. (man 5 apt.conf)"), "Acquire::http::Pipeline-Depth");
			   Server->Pipeline = false;
			   Server->PipelineAllowed = false;
			   // we keep the PipelineDepth value so that the rest of the queue can be fixed up as well
			}
			Rename(Res.Filename, I->DestFile);
			Res.Filename = I->DestFile;
			BeforeI->Next = I->Next;
			I->Next = Queue;
			Queue = I;
			break;
		     }
		     BeforeI = I;
		  }
	       }
	       Res.TakeHashes(*resultHashes);
	       URIDone(Res);
	    }
	    else
	    {
	       if (Server->IsOpen() == false)
	       {
		  FailCounter++;
		  _error->Discard();
		  Server->Close();
		  
		  if (FailCounter >= 2)
		  {
		     Fail(_("Connection failed"),true);
		     FailCounter = 0;
		  }
		  
		  QueueBack = Queue;
	       }
	       else
               {
                  Server->Close();
		  Fail(true);
               }
	    }
	    break;
	 }
	 
	 // IMS hit
	 case IMS_HIT:
	 {
	    URIDone(Res);
	    break;
	 }
	 
	 // Hard server error, not found or something
	 case ERROR_UNRECOVERABLE:
	 {
	    Fail();
	    break;
	 }
	  
	 // Hard internal error, kill the connection and fail
	 case ERROR_NOT_FROM_SERVER:
	 {
	    Fail();
	    RotateDNS();
	    Server->Close();
	    break;
	 }

	 // We need to flush the data, the header is like a 404 w/ error text
	 case ERROR_WITH_CONTENT_PAGE:
	 {
	    Server->RunDataToDevNull(Req);
	    Fail();
	    break;
	 }

	 // Try again with a new URL
	 case TRY_AGAIN_OR_REDIRECT:
	 {
	    // Clear rest of response if there is content
	    if (Req.HaveContent)
	       Server->RunDataToDevNull(Req);
	    Redirect(NextURI);
	    break;
	 }

	 default:
	 Fail(_("Internal error"));
	 break;
      }
      
      FailCounter = 0;
   }
   
   return 0;
}
									/*}}}*/
unsigned long long BaseHttpMethod::FindMaximumObjectSizeInQueue() const	/*{{{*/
{
   unsigned long long MaxSizeInQueue = 0;
   for (FetchItem *I = Queue; I != 0 && I != QueueBack; I = I->Next)
      MaxSizeInQueue = std::max(MaxSizeInQueue, I->MaximumSize);
   return MaxSizeInQueue;
}
									/*}}}*/
BaseHttpMethod::BaseHttpMethod(std::string &&Binary, char const * const Ver,unsigned long const Flags) :/*{{{*/
   aptMethod(std::move(Binary), Ver, Flags), Server(nullptr), PipelineDepth(10),
   AllowRedirect(false), Debug(false)
{
}
									/*}}}*/
bool BaseHttpMethod::Configuration(std::string Message)			/*{{{*/
{
   if (aptMethod::Configuration(Message) == false)
      return false;

   _config->CndSet("Acquire::tor::Proxy",
	 "socks5h://apt-transport-tor@localhost:9050");
   return true;
}
									/*}}}*/
bool BaseHttpMethod::AddProxyAuth(URI &Proxy, URI const &Server) const	/*{{{*/
{
   if (std::find(methodNames.begin(), methodNames.end(), "tor") != methodNames.end() &&
	 Proxy.User == "apt-transport-tor" && Proxy.Password.empty())
   {
      std::string pass = Server.Host;
      pass.erase(std::remove_if(pass.begin(), pass.end(), [](char const c) { return std::isalnum(c) == 0; }), pass.end());
      if (pass.length() > 255)
	 Proxy.Password = pass.substr(0, 255);
      else
	 Proxy.Password = std::move(pass);
   }
   // FIXME: should we support auth.conf for proxies?
   return true;
}
									/*}}}*/