methods/http.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: http.cc,v 1.59 2004/05/08 19:42:35 mdz Exp $
   4 /* ######################################################################
   5
   6    HTTP Acquire Method - This is the HTTP acquire method for APT.
   7
   8    It uses HTTP/1.1 and many of the fancy options there-in, such as
   9    pipelining, range, if-range and so on.
  10
  11    It is based on a doubly buffered select loop. A groupe of requests are
  12    fed into a single output buffer that is constantly fed out the
  13    socket. This provides ideal pipelining as in many cases all of the
  14    requests will fit into a single packet. The input socket is buffered
  15    the same way and fed into the fd for the file (may be a pipe in future).
  16
  17    This double buffering provides fairly substantial transfer rates,
  18    compared to wget the http method is about 4% faster. Most importantly,
  19    when HTTP is compared with FTP as a protocol the speed difference is
  20    huge. In tests over the internet from two sites to llug (via ATM) this
  21    program got 230k/s sustained http transfer rates. FTP on the other
  22    hand topped out at 170k/s. That combined with the time to setup the
  23    FTP connection makes HTTP a vastly superior protocol.
  24
  25    ##################################################################### */
  26                                                                         /*}}}*/
  27 // Include Files                                                        /*{{{*/
  28 #include <config.h>
  29
  30 #include <apt-pkg/fileutl.h>
  31 #include <apt-pkg/configuration.h>
  32 #include <apt-pkg/error.h>
  33 #include <apt-pkg/hashes.h>
  34 #include <apt-pkg/netrc.h>
  35 #include <apt-pkg/strutl.h>
  36 #include <apt-pkg/proxy.h>
  37
  38 #include <stddef.h>
  39 #include <stdlib.h>
  40 #include <sys/select.h>
  41 #include <cstring>
  42 #include <sys/stat.h>
  43 #include <sys/time.h>
  44 #include <unistd.h>
  45 #include <stdio.h>
  46 #include <errno.h>
  47 #include <iostream>
  48 #include <sstream>
  49
  50 #include "config.h"
  51 #include "connect.h"
  52 #include "http.h"
  53
  54 #include <apti18n.h>
  55                                                                         /*}}}*/
  56 using namespace std;
  57
  58 unsigned long long CircleBuf::BwReadLimit=0;
  59 unsigned long long CircleBuf::BwTickReadData=0;
  60 struct timeval CircleBuf::BwReadTick={0,0};
  61 const unsigned int CircleBuf::BW_HZ=10;
  62
  63 // CircleBuf::CircleBuf - Circular input buffer                         /*{{{*/
  64 // ---------------------------------------------------------------------
  65 /* */
  66 CircleBuf::CircleBuf(unsigned long long Size)
  67    : Size(Size), Hash(NULL), TotalWriten(0)
  68 {
  69    Buf = new unsigned char[Size];
  70    Reset();
  71
  72    CircleBuf::BwReadLimit = _config->FindI("Acquire::http::Dl-Limit",0)*1024;
  73 }
  74                                                                         /*}}}*/
  75 // CircleBuf::Reset - Reset to the default state                        /*{{{*/
  76 // ---------------------------------------------------------------------
  77 /* */
  78 void CircleBuf::Reset()
  79 {
  80    InP = 0;
  81    OutP = 0;
  82    StrPos = 0;
  83    TotalWriten = 0;
  84    MaxGet = (unsigned long long)-1;
  85    OutQueue = string();
  86    if (Hash != NULL)
  87    {
  88       delete Hash;
  89       Hash = NULL;
  90    }
  91 }
  92                                                                         /*}}}*/
  93 // CircleBuf::Read - Read from a FD into the circular buffer            /*{{{*/
  94 // ---------------------------------------------------------------------
  95 /* This fills up the buffer with as much data as is in the FD, assuming it
  96    is non-blocking.. */
  97 bool CircleBuf::Read(int Fd)
  98 {
  99    while (1)
 100    {
 101       // Woops, buffer is full
 102       if (InP - OutP == Size)
 103          return true;
 104
 105       // what's left to read in this tick
 106       unsigned long long const BwReadMax = CircleBuf::BwReadLimit/BW_HZ;
 107
 108       if(CircleBuf::BwReadLimit) {
 109          struct timeval now;
 110          gettimeofday(&now,0);
 111
 112          unsigned long long d = (now.tv_sec-CircleBuf::BwReadTick.tv_sec)*1000000 +
 113             now.tv_usec-CircleBuf::BwReadTick.tv_usec;
 114          if(d > 1000000/BW_HZ) {
 115             CircleBuf::BwReadTick = now;
 116             CircleBuf::BwTickReadData = 0;
 117          }
 118
 119          if(CircleBuf::BwTickReadData >= BwReadMax) {
 120             usleep(1000000/BW_HZ);
 121             return true;
 122          }
 123       }
 124
 125       // Write the buffer segment
 126       ssize_t Res;
 127       if(CircleBuf::BwReadLimit) {
 128          Res = read(Fd,Buf + (InP%Size),
 129                     BwReadMax > LeftRead() ? LeftRead() : BwReadMax);
 130       } else
 131          Res = read(Fd,Buf + (InP%Size),LeftRead());
 132
 133       if(Res > 0 && BwReadLimit > 0)
 134          CircleBuf::BwTickReadData += Res;
 135
 136       if (Res == 0)
 137          return false;
 138       if (Res < 0)
 139       {
 140          if (errno == EAGAIN)
 141             return true;
 142          return false;
 143       }
 144
 145       if (InP == 0)
 146          gettimeofday(&Start,0);
 147       InP += Res;
 148    }
 149 }
 150                                                                         /*}}}*/
 151 // CircleBuf::Read - Put the string into the buffer                     /*{{{*/
 152 // ---------------------------------------------------------------------
 153 /* This will hold the string in and fill the buffer with it as it empties */
 154 bool CircleBuf::Read(string Data)
 155 {
 156    OutQueue += Data;
 157    FillOut();
 158    return true;
 159 }
 160                                                                         /*}}}*/
 161 // CircleBuf::FillOut - Fill the buffer from the output queue           /*{{{*/
 162 // ---------------------------------------------------------------------
 163 /* */
 164 void CircleBuf::FillOut()
 165 {
 166    if (OutQueue.empty() == true)
 167       return;
 168    while (1)
 169    {
 170       // Woops, buffer is full
 171       if (InP - OutP == Size)
 172          return;
 173
 174       // Write the buffer segment
 175       unsigned long long Sz = LeftRead();
 176       if (OutQueue.length() - StrPos < Sz)
 177          Sz = OutQueue.length() - StrPos;
 178       memcpy(Buf + (InP%Size),OutQueue.c_str() + StrPos,Sz);
 179
 180       // Advance
 181       StrPos += Sz;
 182       InP += Sz;
 183       if (OutQueue.length() == StrPos)
 184       {
 185          StrPos = 0;
 186          OutQueue = "";
 187          return;
 188       }
 189    }
 190 }
 191                                                                         /*}}}*/
 192 // CircleBuf::Write - Write from the buffer into a FD                   /*{{{*/
 193 // ---------------------------------------------------------------------
 194 /* This empties the buffer into the FD. */
 195 bool CircleBuf::Write(int Fd)
 196 {
 197    while (1)
 198    {
 199       FillOut();
 200
 201       // Woops, buffer is empty
 202       if (OutP == InP)
 203          return true;
 204
 205       if (OutP == MaxGet)
 206          return true;
 207
 208       // Write the buffer segment
 209       ssize_t Res;
 210       Res = write(Fd,Buf + (OutP%Size),LeftWrite());
 211
 212       if (Res == 0)
 213          return false;
 214       if (Res < 0)
 215       {
 216          if (errno == EAGAIN)
 217             return true;
 218
 219          return false;
 220       }
 221
 222       TotalWriten += Res;
 223
 224       if (Hash != NULL)
 225          Hash->Add(Buf + (OutP%Size),Res);
 226
 227       OutP += Res;
 228    }
 229 }
 230                                                                         /*}}}*/
 231 // CircleBuf::WriteTillEl - Write from the buffer to a string           /*{{{*/
 232 // ---------------------------------------------------------------------
 233 /* This copies till the first empty line */
 234 bool CircleBuf::WriteTillEl(string &Data,bool Single)
 235 {
 236    // We cheat and assume it is unneeded to have more than one buffer load
 237    for (unsigned long long I = OutP; I < InP; I++)
 238    {
 239       if (Buf[I%Size] != '\n')
 240          continue;
 241       ++I;
 242
 243       if (Single == false)
 244       {
 245          if (I < InP  && Buf[I%Size] == '\r')
 246             ++I;
 247          if (I >= InP || Buf[I%Size] != '\n')
 248             continue;
 249          ++I;
 250       }
 251
 252       Data = "";
 253       while (OutP < I)
 254       {
 255          unsigned long long Sz = LeftWrite();
 256          if (Sz == 0)
 257             return false;
 258          if (I - OutP < Sz)
 259             Sz = I - OutP;
 260          Data += string((char *)(Buf + (OutP%Size)),Sz);
 261          OutP += Sz;
 262       }
 263       return true;
 264    }
 265    return false;
 266 }
 267                                                                         /*}}}*/
 268 // CircleBuf::Stats - Print out stats information                       /*{{{*/
 269 // ---------------------------------------------------------------------
 270 /* */
 271 void CircleBuf::Stats()
 272 {
 273    if (InP == 0)
 274       return;
 275
 276    struct timeval Stop;
 277    gettimeofday(&Stop,0);
 278 /*   float Diff = Stop.tv_sec - Start.tv_sec +
 279              (float)(Stop.tv_usec - Start.tv_usec)/1000000;
 280    clog << "Got " << InP << " in " << Diff << " at " << InP/Diff << endl;*/
 281 }
 282                                                                         /*}}}*/
 283 CircleBuf::~CircleBuf()
 284 {
 285    delete [] Buf;
 286    delete Hash;
 287 }
 288
 289 // HttpServerState::HttpServerState - Constructor                       /*{{{*/
 290 HttpServerState::HttpServerState(URI Srv,HttpMethod *Owner) : ServerState(Srv, Owner), In(64*1024), Out(4*1024)
 291 {
 292    TimeOut = _config->FindI("Acquire::http::Timeout",TimeOut);
 293    Reset();
 294 }
 295                                                                         /*}}}*/
 296 // HttpServerState::Open - Open a connection to the server              /*{{{*/
 297 // ---------------------------------------------------------------------
 298 /* This opens a connection to the server. */
 299 bool HttpServerState::Open()
 300 {
 301    // Use the already open connection if possible.
 302    if (ServerFd != -1)
 303       return true;
 304
 305    Close();
 306    In.Reset();
 307    Out.Reset();
 308    Persistent = true;
 309
 310    // Determine the proxy setting
 311    AutoDetectProxy(ServerName);
 312    string SpecificProxy = _config->Find("Acquire::http::Proxy::" + ServerName.Host);
 313    if (!SpecificProxy.empty())
 314    {
 315            if (SpecificProxy == "DIRECT")
 316                    Proxy = "";
 317            else
 318                    Proxy = SpecificProxy;
 319    }
 320    else
 321    {
 322            string DefProxy = _config->Find("Acquire::http::Proxy");
 323            if (!DefProxy.empty())
 324            {
 325                    Proxy = DefProxy;
 326            }
 327            else
 328            {
 329                    char* result = getenv("http_proxy");
 330                    Proxy = result ? result : "";
 331            }
 332    }
 333
 334    // Parse no_proxy, a , separated list of domains
 335    if (getenv("no_proxy") != 0)
 336    {
 337       if (CheckDomainList(ServerName.Host,getenv("no_proxy")) == true)
 338          Proxy = "";
 339    }
 340
 341    // Determine what host and port to use based on the proxy settings
 342    int Port = 0;
 343    string Host;
 344    if (Proxy.empty() == true || Proxy.Host.empty() == true)
 345    {
 346       if (ServerName.Port != 0)
 347          Port = ServerName.Port;
 348       Host = ServerName.Host;
 349    }
 350    else
 351    {
 352       if (Proxy.Port != 0)
 353          Port = Proxy.Port;
 354       Host = Proxy.Host;
 355    }
 356
 357    // Connect to the remote server
 358    if (Connect(Host,Port,"http",80,ServerFd,TimeOut,Owner) == false)
 359       return false;
 360
 361    return true;
 362 }
 363                                                                         /*}}}*/
 364 // HttpServerState::Close - Close a connection to the server            /*{{{*/
 365 // ---------------------------------------------------------------------
 366 /* */
 367 bool HttpServerState::Close()
 368 {
 369    close(ServerFd);
 370    ServerFd = -1;
 371    return true;
 372 }
 373                                                                         /*}}}*/
 374 // HttpServerState::RunData - Transfer the data from the socket         /*{{{*/
 375 bool HttpServerState::RunData(FileFd * const File)
 376 {
 377    State = Data;
 378
 379    // Chunked transfer encoding is fun..
 380    if (Encoding == Chunked)
 381    {
 382       while (1)
 383       {
 384          // Grab the block size
 385          bool Last = true;
 386          string Data;
 387          In.Limit(-1);
 388          do
 389          {
 390             if (In.WriteTillEl(Data,true) == true)
 391                break;
 392          }
 393          while ((Last = Go(false, File)) == true);
 394
 395          if (Last == false)
 396             return false;
 397
 398          // See if we are done
 399          unsigned long long Len = strtoull(Data.c_str(),0,16);
 400          if (Len == 0)
 401          {
 402             In.Limit(-1);
 403
 404             // We have to remove the entity trailer
 405             Last = true;
 406             do
 407             {
 408                if (In.WriteTillEl(Data,true) == true && Data.length() <= 2)
 409                   break;
 410             }
 411             while ((Last = Go(false, File)) == true);
 412             if (Last == false)
 413                return false;
 414             return !_error->PendingError();
 415          }
 416
 417          // Transfer the block
 418          In.Limit(Len);
 419          while (Go(true, File) == true)
 420             if (In.IsLimit() == true)
 421                break;
 422
 423          // Error
 424          if (In.IsLimit() == false)
 425             return false;
 426
 427          // The server sends an extra new line before the next block specifier..
 428          In.Limit(-1);
 429          Last = true;
 430          do
 431          {
 432             if (In.WriteTillEl(Data,true) == true)
 433                break;
 434          }
 435          while ((Last = Go(false, File)) == true);
 436          if (Last == false)
 437             return false;
 438       }
 439    }
 440    else
 441    {
 442       /* Closes encoding is used when the server did not specify a size, the
 443          loss of the connection means we are done */
 444       if (JunkSize != 0)
 445          In.Limit(JunkSize);
 446       else if (DownloadSize != 0)
 447          In.Limit(DownloadSize);
 448       else if (Persistent == false)
 449          In.Limit(-1);
 450
 451       // Just transfer the whole block.
 452       do
 453       {
 454          if (In.IsLimit() == false)
 455             continue;
 456
 457          In.Limit(-1);
 458          return !_error->PendingError();
 459       }
 460       while (Go(true, File) == true);
 461    }
 462
 463    return Owner->Flush() && !_error->PendingError();
 464 }
 465                                                                         /*}}}*/
 466 bool HttpServerState::ReadHeaderLines(std::string &Data)                /*{{{*/
 467 {
 468    return In.WriteTillEl(Data);
 469 }
 470                                                                         /*}}}*/
 471 bool HttpServerState::LoadNextResponse(bool const ToFile, FileFd * const File)/*{{{*/
 472 {
 473    return Go(ToFile, File);
 474 }
 475                                                                         /*}}}*/
 476 bool HttpServerState::WriteResponse(const std::string &Data)            /*{{{*/
 477 {
 478    return Out.Read(Data);
 479 }
 480                                                                         /*}}}*/
 481 APT_PURE bool HttpServerState::IsOpen()                                 /*{{{*/
 482 {
 483    return (ServerFd != -1);
 484 }
 485                                                                         /*}}}*/
 486 bool HttpServerState::InitHashes(HashStringList const &ExpectedHashes)  /*{{{*/
 487 {
 488    delete In.Hash;
 489    In.Hash = new Hashes(ExpectedHashes);
 490    return true;
 491 }
 492                                                                         /*}}}*/
 493
 494 APT_PURE Hashes * HttpServerState::GetHashes()                          /*{{{*/
 495 {
 496    return In.Hash;
 497 }
 498                                                                         /*}}}*/
 499 // HttpServerState::Die - The server has closed the connection.         /*{{{*/
 500 bool HttpServerState::Die(FileFd &File)
 501 {
 502    unsigned int LErrno = errno;
 503
 504    // Dump the buffer to the file
 505    if (State == ServerState::Data)
 506    {
 507       // on GNU/kFreeBSD, apt dies on /dev/null because non-blocking
 508       // can't be set
 509       if (File.Name() != "/dev/null")
 510          SetNonBlock(File.Fd(),false);
 511       while (In.WriteSpace() == true)
 512       {
 513          if (In.Write(File.Fd()) == false)
 514             return _error->Errno("write",_("Error writing to the file"));
 515
 516          // Done
 517          if (In.IsLimit() == true)
 518             return true;
 519       }
 520    }
 521
 522    // See if this is because the server finished the data stream
 523    if (In.IsLimit() == false && State != HttpServerState::Header &&
 524        Persistent == true)
 525    {
 526       Close();
 527       if (LErrno == 0)
 528          return _error->Error(_("Error reading from server. Remote end closed connection"));
 529       errno = LErrno;
 530       return _error->Errno("read",_("Error reading from server"));
 531    }
 532    else
 533    {
 534       In.Limit(-1);
 535
 536       // Nothing left in the buffer
 537       if (In.WriteSpace() == false)
 538          return false;
 539
 540       // We may have got multiple responses back in one packet..
 541       Close();
 542       return true;
 543    }
 544
 545    return false;
 546 }
 547                                                                         /*}}}*/
 548 // HttpServerState::Flush - Dump the buffer into the file               /*{{{*/
 549 // ---------------------------------------------------------------------
 550 /* This takes the current input buffer from the Server FD and writes it
 551    into the file */
 552 bool HttpServerState::Flush(FileFd * const File)
 553 {
 554    if (File != NULL)
 555    {
 556       // on GNU/kFreeBSD, apt dies on /dev/null because non-blocking
 557       // can't be set
 558       if (File->Name() != "/dev/null")
 559          SetNonBlock(File->Fd(),false);
 560       if (In.WriteSpace() == false)
 561          return true;
 562
 563       while (In.WriteSpace() == true)
 564       {
 565          if (In.Write(File->Fd()) == false)
 566             return _error->Errno("write",_("Error writing to file"));
 567          if (In.IsLimit() == true)
 568             return true;
 569       }
 570
 571       if (In.IsLimit() == true || Persistent == false)
 572          return true;
 573    }
 574    return false;
 575 }
 576                                                                         /*}}}*/
 577 // HttpServerState::Go - Run a single loop                              /*{{{*/
 578 // ---------------------------------------------------------------------
 579 /* This runs the select loop over the server FDs, Output file FDs and
 580    stdin. */
 581 bool HttpServerState::Go(bool ToFile, FileFd * const File)
 582 {
 583    // Server has closed the connection
 584    if (ServerFd == -1 && (In.WriteSpace() == false ||
 585                                ToFile == false))
 586       return false;
 587
 588    fd_set rfds,wfds;
 589    FD_ZERO(&rfds);
 590    FD_ZERO(&wfds);
 591
 592    /* Add the server. We only send more requests if the connection will
 593       be persisting */
 594    if (Out.WriteSpace() == true && ServerFd != -1
 595        && Persistent == true)
 596       FD_SET(ServerFd,&wfds);
 597    if (In.ReadSpace() == true && ServerFd != -1)
 598       FD_SET(ServerFd,&rfds);
 599
 600    // Add the file
 601    int FileFD = -1;
 602    if (File != NULL)
 603       FileFD = File->Fd();
 604
 605    if (In.WriteSpace() == true && ToFile == true && FileFD != -1)
 606       FD_SET(FileFD,&wfds);
 607
 608    // Add stdin
 609    if (_config->FindB("Acquire::http::DependOnSTDIN", true) == true)
 610       FD_SET(STDIN_FILENO,&rfds);
 611
 612    // Figure out the max fd
 613    int MaxFd = FileFD;
 614    if (MaxFd < ServerFd)
 615       MaxFd = ServerFd;
 616
 617    // Select
 618    struct timeval tv;
 619    tv.tv_sec = TimeOut;
 620    tv.tv_usec = 0;
 621    int Res = 0;
 622    if ((Res = select(MaxFd+1,&rfds,&wfds,0,&tv)) < 0)
 623    {
 624       if (errno == EINTR)
 625          return true;
 626       return _error->Errno("select",_("Select failed"));
 627    }
 628
 629    if (Res == 0)
 630    {
 631       _error->Error(_("Connection timed out"));
 632       return Die(*File);
 633    }
 634
 635    // Handle server IO
 636    if (ServerFd != -1 && FD_ISSET(ServerFd,&rfds))
 637    {
 638       errno = 0;
 639       if (In.Read(ServerFd) == false)
 640          return Die(*File);
 641    }
 642
 643    if (ServerFd != -1 && FD_ISSET(ServerFd,&wfds))
 644    {
 645       errno = 0;
 646       if (Out.Write(ServerFd) == false)
 647          return Die(*File);
 648    }
 649
 650    // Send data to the file
 651    if (FileFD != -1 && FD_ISSET(FileFD,&wfds))
 652    {
 653       if (In.Write(FileFD) == false)
 654          return _error->Errno("write",_("Error writing to output file"));
 655    }
 656
 657    if (MaximumSize > 0 && File && File->Tell() > MaximumSize)
 658    {
 659       Owner->SetFailReason("MaximumSizeExceeded");
 660       return _error->Error("Writing more data than expected (%llu > %llu)",
 661                            File->Tell(), MaximumSize);
 662    }
 663
 664    // Handle commands from APT
 665    if (FD_ISSET(STDIN_FILENO,&rfds))
 666    {
 667       if (Owner->Run(true) != -1)
 668          exit(100);
 669    }
 670
 671    return true;
 672 }
 673                                                                         /*}}}*/
 674
 675 // HttpMethod::SendReq - Send the HTTP request                          /*{{{*/
 676 // ---------------------------------------------------------------------
 677 /* This places the http request in the outbound buffer */
 678 void HttpMethod::SendReq(FetchItem *Itm)
 679 {
 680    URI Uri = Itm->Uri;
 681
 682    // The HTTP server expects a hostname with a trailing :port
 683    std::stringstream Req;
 684    string ProperHost;
 685
 686    if (Uri.Host.find(':') != string::npos)
 687       ProperHost = '[' + Uri.Host + ']';
 688    else
 689       ProperHost = Uri.Host;
 690
 691    /* RFC 2616 §5.1.2 requires absolute URIs for requests to proxies,
 692       but while its a must for all servers to accept absolute URIs,
 693       it is assumed clients will sent an absolute path for non-proxies */
 694    std::string requesturi;
 695    if (Server->Proxy.empty() == true || Server->Proxy.Host.empty())
 696       requesturi = Uri.Path;
 697    else
 698       requesturi = Itm->Uri;
 699
 700    // The "+" is encoded as a workaround for a amazon S3 bug
 701    // see LP bugs #1003633 and #1086997.
 702    requesturi = QuoteString(requesturi, "+~ ");
 703
 704    /* Build the request. No keep-alive is included as it is the default
 705       in 1.1, can cause problems with proxies, and we are an HTTP/1.1
 706       client anyway.
 707       C.f. https://tools.ietf.org/wg/httpbis/trac/ticket/158 */
 708    Req << "GET " << requesturi << " HTTP/1.1\r\n";
 709    if (Uri.Port != 0)
 710       Req << "Host: " << ProperHost << ":" << std::to_string(Uri.Port) << "\r\n";
 711    else
 712       Req << "Host: " << ProperHost << "\r\n";
 713
 714    // generate a cache control header (if needed)
 715    if (_config->FindB("Acquire::http::No-Cache",false) == true)
 716       Req << "Cache-Control: no-cache\r\n"
 717          << "Pragma: no-cache\r\n";
 718    else if (Itm->IndexFile == true)
 719       Req << "Cache-Control: max-age=" << std::to_string(_config->FindI("Acquire::http::Max-Age",0)) << "\r\n";
 720    else if (_config->FindB("Acquire::http::No-Store",false) == true)
 721       Req << "Cache-Control: no-store\r\n";
 722
 723    // If we ask for uncompressed files servers might respond with content-
 724    // negotiation which lets us end up with compressed files we do not support,
 725    // see 657029, 657560 and co, so if we have no extension on the request
 726    // ask for text only. As a sidenote: If there is nothing to negotate servers
 727    // seem to be nice and ignore it.
 728    if (_config->FindB("Acquire::http::SendAccept", true) == true)
 729    {
 730       size_t const filepos = Itm->Uri.find_last_of('/');
 731       string const file = Itm->Uri.substr(filepos + 1);
 732       if (flExtension(file) == file)
 733          Req << "Accept: text/*\r\n";
 734    }
 735
 736    // Check for a partial file and send if-queries accordingly
 737    struct stat SBuf;
 738    if (stat(Itm->DestFile.c_str(),&SBuf) >= 0 && SBuf.st_size > 0)
 739       Req << "Range: bytes=" << SBuf.st_size << "-\r\n"
 740          << "If-Range: " << TimeRFC1123(SBuf.st_mtime, false) << "\r\n";
 741    else if (Itm->LastModified != 0)
 742       Req << "If-Modified-Since: " << TimeRFC1123(Itm->LastModified, false).c_str() << "\r\n";
 743
 744    if (Server->Proxy.User.empty() == false || Server->Proxy.Password.empty() == false)
 745       Req << "Proxy-Authorization: Basic "
 746          << Base64Encode(Server->Proxy.User + ":" + Server->Proxy.Password) << "\r\n";
 747
 748    maybe_add_auth (Uri, _config->FindFile("Dir::Etc::netrc"));
 749    if (Uri.User.empty() == false || Uri.Password.empty() == false)
 750       Req << "Authorization: Basic "
 751          << Base64Encode(Uri.User + ":" + Uri.Password) << "\r\n";
 752
 753    Req << "User-Agent: " << _config->Find("Acquire::http::User-Agent",
 754                 "Debian APT-HTTP/1.3 (" PACKAGE_VERSION ")") << "\r\n";
 755
 756    Req << "\r\n";
 757
 758    if (Debug == true)
 759       cerr << Req.str() << endl;
 760
 761    Server->WriteResponse(Req.str());
 762 }
 763                                                                         /*}}}*/
 764 // HttpMethod::Configuration - Handle a configuration message           /*{{{*/
 765 // ---------------------------------------------------------------------
 766 /* We stash the desired pipeline depth */
 767 bool HttpMethod::Configuration(string Message)
 768 {
 769    if (ServerMethod::Configuration(Message) == false)
 770       return false;
 771
 772    AllowRedirect = _config->FindB("Acquire::http::AllowRedirect",true);
 773    PipelineDepth = _config->FindI("Acquire::http::Pipeline-Depth",
 774                                   PipelineDepth);
 775    Debug = _config->FindB("Debug::Acquire::http",false);
 776
 777    return true;
 778 }
 779                                                                         /*}}}*/
 780 std::unique_ptr<ServerState> HttpMethod::CreateServerState(URI const &uri)/*{{{*/
 781 {
 782    return std::unique_ptr<ServerState>(new HttpServerState(uri, this));
 783 }
 784                                                                         /*}}}*/
 785 void HttpMethod::RotateDNS()                                            /*{{{*/
 786 {
 787    ::RotateDNS();
 788 }
 789                                                                         /*}}}*/