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 aquire 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/acquire-method.h>
  32 #include <apt-pkg/configuration.h>
  33 #include <apt-pkg/error.h>
  34 #include <apt-pkg/hashes.h>
  35 #include <apt-pkg/netrc.h>
  36
  37 #include <sys/stat.h>
  38 #include <sys/time.h>
  39 #include <utime.h>
  40 #include <unistd.h>
  41 #include <signal.h>
  42 #include <stdio.h>
  43 #include <errno.h>
  44 #include <string.h>
  45 #include <climits>
  46 #include <iostream>
  47 #include <map>
  48
  49 // Internet stuff
  50 #include <netdb.h>
  51
  52 #include "config.h"
  53 #include "connect.h"
  54 #include "rfc2553emu.h"
  55 #include "http.h"
  56
  57 #include <apti18n.h>
  58                                                                         /*}}}*/
  59 using namespace std;
  60
  61 string HttpMethod::FailFile;
  62 int HttpMethod::FailFd = -1;
  63 time_t HttpMethod::FailTime = 0;
  64 unsigned long PipelineDepth = 0;
  65 unsigned long TimeOut = 120;
  66 bool AllowRedirect = false;
  67 bool Debug = false;
  68 URI Proxy;
  69
  70 unsigned long long CircleBuf::BwReadLimit=0;
  71 unsigned long long CircleBuf::BwTickReadData=0;
  72 struct timeval CircleBuf::BwReadTick={0,0};
  73 const unsigned int CircleBuf::BW_HZ=10;
  74
  75 // CircleBuf::CircleBuf - Circular input buffer                         /*{{{*/
  76 // ---------------------------------------------------------------------
  77 /* */
  78 CircleBuf::CircleBuf(unsigned long long Size) : Size(Size), Hash(0)
  79 {
  80    Buf = new unsigned char[Size];
  81    Reset();
  82
  83    CircleBuf::BwReadLimit = _config->FindI("Acquire::http::Dl-Limit",0)*1024;
  84 }
  85                                                                         /*}}}*/
  86 // CircleBuf::Reset - Reset to the default state                        /*{{{*/
  87 // ---------------------------------------------------------------------
  88 /* */
  89 void CircleBuf::Reset()
  90 {
  91    InP = 0;
  92    OutP = 0;
  93    StrPos = 0;
  94    MaxGet = (unsigned long long)-1;
  95    OutQueue = string();
  96    if (Hash != 0)
  97    {
  98       delete Hash;
  99       Hash = new Hashes;
 100    }
 101 };
 102                                                                         /*}}}*/
 103 // CircleBuf::Read - Read from a FD into the circular buffer            /*{{{*/
 104 // ---------------------------------------------------------------------
 105 /* This fills up the buffer with as much data as is in the FD, assuming it
 106    is non-blocking.. */
 107 bool CircleBuf::Read(int Fd)
 108 {
 109    unsigned long long BwReadMax;
 110
 111    while (1)
 112    {
 113       // Woops, buffer is full
 114       if (InP - OutP == Size)
 115          return true;
 116
 117       // what's left to read in this tick
 118       BwReadMax = CircleBuf::BwReadLimit/BW_HZ;
 119
 120       if(CircleBuf::BwReadLimit) {
 121          struct timeval now;
 122          gettimeofday(&now,0);
 123
 124          unsigned long long d = (now.tv_sec-CircleBuf::BwReadTick.tv_sec)*1000000 +
 125             now.tv_usec-CircleBuf::BwReadTick.tv_usec;
 126          if(d > 1000000/BW_HZ) {
 127             CircleBuf::BwReadTick = now;
 128             CircleBuf::BwTickReadData = 0;
 129          }
 130
 131          if(CircleBuf::BwTickReadData >= BwReadMax) {
 132             usleep(1000000/BW_HZ);
 133             return true;
 134          }
 135       }
 136
 137       // Write the buffer segment
 138       ssize_t Res;
 139       if(CircleBuf::BwReadLimit) {
 140          Res = read(Fd,Buf + (InP%Size),
 141                     BwReadMax > LeftRead() ? LeftRead() : BwReadMax);
 142       } else
 143          Res = read(Fd,Buf + (InP%Size),LeftRead());
 144
 145       if(Res > 0 && BwReadLimit > 0)
 146          CircleBuf::BwTickReadData += Res;
 147
 148       if (Res == 0)
 149          return false;
 150       if (Res < 0)
 151       {
 152          if (errno == EAGAIN)
 153             return true;
 154          return false;
 155       }
 156
 157       if (InP == 0)
 158          gettimeofday(&Start,0);
 159       InP += Res;
 160    }
 161 }
 162                                                                         /*}}}*/
 163 // CircleBuf::Read - Put the string into the buffer                     /*{{{*/
 164 // ---------------------------------------------------------------------
 165 /* This will hold the string in and fill the buffer with it as it empties */
 166 bool CircleBuf::Read(string Data)
 167 {
 168    OutQueue += Data;
 169    FillOut();
 170    return true;
 171 }
 172                                                                         /*}}}*/
 173 // CircleBuf::FillOut - Fill the buffer from the output queue           /*{{{*/
 174 // ---------------------------------------------------------------------
 175 /* */
 176 void CircleBuf::FillOut()
 177 {
 178    if (OutQueue.empty() == true)
 179       return;
 180    while (1)
 181    {
 182       // Woops, buffer is full
 183       if (InP - OutP == Size)
 184          return;
 185
 186       // Write the buffer segment
 187       unsigned long long Sz = LeftRead();
 188       if (OutQueue.length() - StrPos < Sz)
 189          Sz = OutQueue.length() - StrPos;
 190       memcpy(Buf + (InP%Size),OutQueue.c_str() + StrPos,Sz);
 191
 192       // Advance
 193       StrPos += Sz;
 194       InP += Sz;
 195       if (OutQueue.length() == StrPos)
 196       {
 197          StrPos = 0;
 198          OutQueue = "";
 199          return;
 200       }
 201    }
 202 }
 203                                                                         /*}}}*/
 204 // CircleBuf::Write - Write from the buffer into a FD                   /*{{{*/
 205 // ---------------------------------------------------------------------
 206 /* This empties the buffer into the FD. */
 207 bool CircleBuf::Write(int Fd)
 208 {
 209    while (1)
 210    {
 211       FillOut();
 212
 213       // Woops, buffer is empty
 214       if (OutP == InP)
 215          return true;
 216
 217       if (OutP == MaxGet)
 218          return true;
 219
 220       // Write the buffer segment
 221       ssize_t Res;
 222       Res = write(Fd,Buf + (OutP%Size),LeftWrite());
 223
 224       if (Res == 0)
 225          return false;
 226       if (Res < 0)
 227       {
 228          if (errno == EAGAIN)
 229             return true;
 230
 231          return false;
 232       }
 233
 234       if (Hash != 0)
 235          Hash->Add(Buf + (OutP%Size),Res);
 236
 237       OutP += Res;
 238    }
 239 }
 240                                                                         /*}}}*/
 241 // CircleBuf::WriteTillEl - Write from the buffer to a string           /*{{{*/
 242 // ---------------------------------------------------------------------
 243 /* This copies till the first empty line */
 244 bool CircleBuf::WriteTillEl(string &Data,bool Single)
 245 {
 246    // We cheat and assume it is unneeded to have more than one buffer load
 247    for (unsigned long long I = OutP; I < InP; I++)
 248    {
 249       if (Buf[I%Size] != '\n')
 250          continue;
 251       ++I;
 252
 253       if (Single == false)
 254       {
 255          if (I < InP  && Buf[I%Size] == '\r')
 256             ++I;
 257          if (I >= InP || Buf[I%Size] != '\n')
 258             continue;
 259          ++I;
 260       }
 261
 262       Data = "";
 263       while (OutP < I)
 264       {
 265          unsigned long long Sz = LeftWrite();
 266          if (Sz == 0)
 267             return false;
 268          if (I - OutP < Sz)
 269             Sz = I - OutP;
 270          Data += string((char *)(Buf + (OutP%Size)),Sz);
 271          OutP += Sz;
 272       }
 273       return true;
 274    }
 275    return false;
 276 }
 277                                                                         /*}}}*/
 278 // CircleBuf::Stats - Print out stats information                       /*{{{*/
 279 // ---------------------------------------------------------------------
 280 /* */
 281 void CircleBuf::Stats()
 282 {
 283    if (InP == 0)
 284       return;
 285
 286    struct timeval Stop;
 287    gettimeofday(&Stop,0);
 288 /*   float Diff = Stop.tv_sec - Start.tv_sec +
 289              (float)(Stop.tv_usec - Start.tv_usec)/1000000;
 290    clog << "Got " << InP << " in " << Diff << " at " << InP/Diff << endl;*/
 291 }
 292                                                                         /*}}}*/
 293 CircleBuf::~CircleBuf()
 294 {
 295    delete [] Buf;
 296    delete Hash;
 297 }
 298
 299 // ServerState::ServerState - Constructor                               /*{{{*/
 300 // ---------------------------------------------------------------------
 301 /* */
 302 ServerState::ServerState(URI Srv,HttpMethod *Owner) : Owner(Owner),
 303                         In(64*1024), Out(4*1024),
 304                         ServerName(Srv)
 305 {
 306    Reset();
 307 }
 308                                                                         /*}}}*/
 309 // ServerState::Open - Open a connection to the server                  /*{{{*/
 310 // ---------------------------------------------------------------------
 311 /* This opens a connection to the server. */
 312 bool ServerState::Open()
 313 {
 314    // Use the already open connection if possible.
 315    if (ServerFd != -1)
 316       return true;
 317
 318    Close();
 319    In.Reset();
 320    Out.Reset();
 321    Persistent = true;
 322
 323    // Determine the proxy setting
 324    string SpecificProxy = _config->Find("Acquire::http::Proxy::" + ServerName.Host);
 325    if (!SpecificProxy.empty())
 326    {
 327            if (SpecificProxy == "DIRECT")
 328                    Proxy = "";
 329            else
 330                    Proxy = SpecificProxy;
 331    }
 332    else
 333    {
 334            string DefProxy = _config->Find("Acquire::http::Proxy");
 335            if (!DefProxy.empty())
 336            {
 337                    Proxy = DefProxy;
 338            }
 339            else
 340            {
 341                    char* result = getenv("http_proxy");
 342                    Proxy = result ? result : "";
 343            }
 344    }
 345
 346    // Parse no_proxy, a , separated list of domains
 347    if (getenv("no_proxy") != 0)
 348    {
 349       if (CheckDomainList(ServerName.Host,getenv("no_proxy")) == true)
 350          Proxy = "";
 351    }
 352
 353    // Determine what host and port to use based on the proxy settings
 354    int Port = 0;
 355    string Host;
 356    if (Proxy.empty() == true || Proxy.Host.empty() == true)
 357    {
 358       if (ServerName.Port != 0)
 359          Port = ServerName.Port;
 360       Host = ServerName.Host;
 361    }
 362    else
 363    {
 364       if (Proxy.Port != 0)
 365          Port = Proxy.Port;
 366       Host = Proxy.Host;
 367    }
 368
 369    // Connect to the remote server
 370    if (Connect(Host,Port,"http",80,ServerFd,TimeOut,Owner) == false)
 371       return false;
 372
 373    return true;
 374 }
 375                                                                         /*}}}*/
 376 // ServerState::Close - Close a connection to the server                /*{{{*/
 377 // ---------------------------------------------------------------------
 378 /* */
 379 bool ServerState::Close()
 380 {
 381    close(ServerFd);
 382    ServerFd = -1;
 383    return true;
 384 }
 385                                                                         /*}}}*/
 386 // ServerState::RunHeaders - Get the headers before the data            /*{{{*/
 387 // ---------------------------------------------------------------------
 388 /* Returns 0 if things are OK, 1 if an IO error occurred and 2 if a header
 389    parse error occurred */
 390 ServerState::RunHeadersResult ServerState::RunHeaders()
 391 {
 392    State = Header;
 393
 394    Owner->Status(_("Waiting for headers"));
 395
 396    Major = 0;
 397    Minor = 0;
 398    Result = 0;
 399    Size = 0;
 400    StartPos = 0;
 401    Encoding = Closes;
 402    HaveContent = false;
 403    time(&Date);
 404
 405    do
 406    {
 407       string Data;
 408       if (In.WriteTillEl(Data) == false)
 409          continue;
 410
 411       if (Debug == true)
 412          clog << Data;
 413
 414       for (string::const_iterator I = Data.begin(); I < Data.end(); ++I)
 415       {
 416          string::const_iterator J = I;
 417          for (; J != Data.end() && *J != '\n' && *J != '\r'; ++J);
 418          if (HeaderLine(string(I,J)) == false)
 419             return RUN_HEADERS_PARSE_ERROR;
 420          I = J;
 421       }
 422
 423       // 100 Continue is a Nop...
 424       if (Result == 100)
 425          continue;
 426
 427       // Tidy up the connection persistance state.
 428       if (Encoding == Closes && HaveContent == true)
 429          Persistent = false;
 430
 431       return RUN_HEADERS_OK;
 432    }
 433    while (Owner->Go(false,this) == true);
 434
 435    return RUN_HEADERS_IO_ERROR;
 436 }
 437                                                                         /*}}}*/
 438 // ServerState::RunData - Transfer the data from the socket             /*{{{*/
 439 // ---------------------------------------------------------------------
 440 /* */
 441 bool ServerState::RunData()
 442 {
 443    State = Data;
 444
 445    // Chunked transfer encoding is fun..
 446    if (Encoding == Chunked)
 447    {
 448       while (1)
 449       {
 450          // Grab the block size
 451          bool Last = true;
 452          string Data;
 453          In.Limit(-1);
 454          do
 455          {
 456             if (In.WriteTillEl(Data,true) == true)
 457                break;
 458          }
 459          while ((Last = Owner->Go(false,this)) == true);
 460
 461          if (Last == false)
 462             return false;
 463
 464          // See if we are done
 465          unsigned long long Len = strtoull(Data.c_str(),0,16);
 466          if (Len == 0)
 467          {
 468             In.Limit(-1);
 469
 470             // We have to remove the entity trailer
 471             Last = true;
 472             do
 473             {
 474                if (In.WriteTillEl(Data,true) == true && Data.length() <= 2)
 475                   break;
 476             }
 477             while ((Last = Owner->Go(false,this)) == true);
 478             if (Last == false)
 479                return false;
 480             return !_error->PendingError();
 481          }
 482
 483          // Transfer the block
 484          In.Limit(Len);
 485          while (Owner->Go(true,this) == true)
 486             if (In.IsLimit() == true)
 487                break;
 488
 489          // Error
 490          if (In.IsLimit() == false)
 491             return false;
 492
 493          // The server sends an extra new line before the next block specifier..
 494          In.Limit(-1);
 495          Last = true;
 496          do
 497          {
 498             if (In.WriteTillEl(Data,true) == true)
 499                break;
 500          }
 501          while ((Last = Owner->Go(false,this)) == true);
 502          if (Last == false)
 503             return false;
 504       }
 505    }
 506    else
 507    {
 508       /* Closes encoding is used when the server did not specify a size, the
 509          loss of the connection means we are done */
 510       if (Encoding == Closes)
 511          In.Limit(-1);
 512       else
 513          In.Limit(Size - StartPos);
 514
 515       // Just transfer the whole block.
 516       do
 517       {
 518          if (In.IsLimit() == false)
 519             continue;
 520
 521          In.Limit(-1);
 522          return !_error->PendingError();
 523       }
 524       while (Owner->Go(true,this) == true);
 525    }
 526
 527    return Owner->Flush(this) && !_error->PendingError();
 528 }
 529                                                                         /*}}}*/
 530 // ServerState::HeaderLine - Process a header line                      /*{{{*/
 531 // ---------------------------------------------------------------------
 532 /* */
 533 bool ServerState::HeaderLine(string Line)
 534 {
 535    if (Line.empty() == true)
 536       return true;
 537
 538    string::size_type Pos = Line.find(' ');
 539    if (Pos == string::npos || Pos+1 > Line.length())
 540    {
 541       // Blah, some servers use "connection:closes", evil.
 542       Pos = Line.find(':');
 543       if (Pos == string::npos || Pos + 2 > Line.length())
 544          return _error->Error(_("Bad header line"));
 545       Pos++;
 546    }
 547
 548    // Parse off any trailing spaces between the : and the next word.
 549    string::size_type Pos2 = Pos;
 550    while (Pos2 < Line.length() && isspace(Line[Pos2]) != 0)
 551       Pos2++;
 552
 553    string Tag = string(Line,0,Pos);
 554    string Val = string(Line,Pos2);
 555
 556    if (stringcasecmp(Tag.c_str(),Tag.c_str()+4,"HTTP") == 0)
 557    {
 558       // Evil servers return no version
 559       if (Line[4] == '/')
 560       {
 561          int const elements = sscanf(Line.c_str(),"HTTP/%3u.%3u %3u%359[^\n]",&Major,&Minor,&Result,Code);
 562          if (elements == 3)
 563          {
 564             Code[0] = '\0';
 565             if (Debug == true)
 566                clog << "HTTP server doesn't give Reason-Phrase for " << Result << std::endl;
 567          }
 568          else if (elements != 4)
 569             return _error->Error(_("The HTTP server sent an invalid reply header"));
 570       }
 571       else
 572       {
 573          Major = 0;
 574          Minor = 9;
 575          if (sscanf(Line.c_str(),"HTTP %3u%359[^\n]",&Result,Code) != 2)
 576             return _error->Error(_("The HTTP server sent an invalid reply header"));
 577       }
 578
 579       /* Check the HTTP response header to get the default persistance
 580          state. */
 581       if (Major < 1)
 582          Persistent = false;
 583       else
 584       {
 585          if (Major == 1 && Minor == 0)
 586             Persistent = false;
 587          else
 588             Persistent = true;
 589       }
 590
 591       return true;
 592    }
 593
 594    if (stringcasecmp(Tag,"Content-Length:") == 0)
 595    {
 596       if (Encoding == Closes)
 597          Encoding = Stream;
 598       HaveContent = true;
 599
 600       // The length is already set from the Content-Range header
 601       if (StartPos != 0)
 602          return true;
 603
 604       Size = strtoull(Val.c_str(), NULL, 10);
 605       if (Size >= std::numeric_limits<unsigned long long>::max())
 606          return _error->Errno("HeaderLine", _("The HTTP server sent an invalid Content-Length header"));
 607       return true;
 608    }
 609
 610    if (stringcasecmp(Tag,"Content-Type:") == 0)
 611    {
 612       HaveContent = true;
 613       return true;
 614    }
 615
 616    if (stringcasecmp(Tag,"Content-Range:") == 0)
 617    {
 618       HaveContent = true;
 619
 620       if (sscanf(Val.c_str(),"bytes %llu-%*u/%llu",&StartPos,&Size) != 2)
 621          return _error->Error(_("The HTTP server sent an invalid Content-Range header"));
 622       if ((unsigned long long)StartPos > Size)
 623          return _error->Error(_("This HTTP server has broken range support"));
 624       return true;
 625    }
 626
 627    if (stringcasecmp(Tag,"Transfer-Encoding:") == 0)
 628    {
 629       HaveContent = true;
 630       if (stringcasecmp(Val,"chunked") == 0)
 631          Encoding = Chunked;
 632       return true;
 633    }
 634
 635    if (stringcasecmp(Tag,"Connection:") == 0)
 636    {
 637       if (stringcasecmp(Val,"close") == 0)
 638          Persistent = false;
 639       if (stringcasecmp(Val,"keep-alive") == 0)
 640          Persistent = true;
 641       return true;
 642    }
 643
 644    if (stringcasecmp(Tag,"Last-Modified:") == 0)
 645    {
 646       if (RFC1123StrToTime(Val.c_str(), Date) == false)
 647          return _error->Error(_("Unknown date format"));
 648       return true;
 649    }
 650
 651    if (stringcasecmp(Tag,"Location:") == 0)
 652    {
 653       Location = Val;
 654       return true;
 655    }
 656
 657    return true;
 658 }
 659                                                                         /*}}}*/
 660
 661 // HttpMethod::SendReq - Send the HTTP request                          /*{{{*/
 662 // ---------------------------------------------------------------------
 663 /* This places the http request in the outbound buffer */
 664 void HttpMethod::SendReq(FetchItem *Itm,CircleBuf &Out)
 665 {
 666    URI Uri = Itm->Uri;
 667
 668    // The HTTP server expects a hostname with a trailing :port
 669    char Buf[1000];
 670    string ProperHost = Uri.Host;
 671    if (Uri.Port != 0)
 672    {
 673       sprintf(Buf,":%u",Uri.Port);
 674       ProperHost += Buf;
 675    }
 676
 677    // Just in case.
 678    if (Itm->Uri.length() >= sizeof(Buf))
 679        abort();
 680
 681    /* Build the request. We include a keep-alive header only for non-proxy
 682       requests. This is to tweak old http/1.0 servers that do support keep-alive
 683       but not HTTP/1.1 automatic keep-alive. Doing this with a proxy server
 684       will glitch HTTP/1.0 proxies because they do not filter it out and
 685       pass it on, HTTP/1.1 says the connection should default to keep alive
 686       and we expect the proxy to do this */
 687    if (Proxy.empty() == true || Proxy.Host.empty())
 688    {
 689       // see LP bugs #1003633 and #1086997. The "+" is encoded as a workaround
 690       // for a amazon S3 bug
 691       sprintf(Buf,"GET %s HTTP/1.1\r\nHost: %s\r\nConnection: keep-alive\r\n",
 692               QuoteString(Uri.Path,"+~ ").c_str(),ProperHost.c_str());
 693    }
 694    else
 695    {
 696       /* Generate a cache control header if necessary. We place a max
 697          cache age on index files, optionally set a no-cache directive
 698          and a no-store directive for archives. */
 699       sprintf(Buf,"GET %s HTTP/1.1\r\nHost: %s\r\n",
 700               Itm->Uri.c_str(),ProperHost.c_str());
 701    }
 702    // generate a cache control header (if needed)
 703    if (_config->FindB("Acquire::http::No-Cache",false) == true)
 704    {
 705       strcat(Buf,"Cache-Control: no-cache\r\nPragma: no-cache\r\n");
 706    }
 707    else
 708    {
 709       if (Itm->IndexFile == true)
 710       {
 711          sprintf(Buf+strlen(Buf),"Cache-Control: max-age=%u\r\n",
 712                  _config->FindI("Acquire::http::Max-Age",0));
 713       }
 714       else
 715       {
 716          if (_config->FindB("Acquire::http::No-Store",false) == true)
 717             strcat(Buf,"Cache-Control: no-store\r\n");
 718       }
 719    }
 720
 721    // If we ask for uncompressed files servers might respond with content-
 722    // negotation which lets us end up with compressed files we do not support,
 723    // see 657029, 657560 and co, so if we have no extension on the request
 724    // ask for text only. As a sidenote: If there is nothing to negotate servers
 725    // seem to be nice and ignore it.
 726    if (_config->FindB("Acquire::http::SendAccept", true) == true)
 727    {
 728       size_t const filepos = Itm->Uri.find_last_of('/');
 729       string const file = Itm->Uri.substr(filepos + 1);
 730       if (flExtension(file) == file)
 731          strcat(Buf,"Accept: text/*\r\n");
 732    }
 733
 734    string Req = Buf;
 735
 736    // Check for a partial file
 737    struct stat SBuf;
 738    if (stat(Itm->DestFile.c_str(),&SBuf) >= 0 && SBuf.st_size > 0)
 739    {
 740       // In this case we send an if-range query with a range header
 741       sprintf(Buf,"Range: bytes=%lli-\r\nIf-Range: %s\r\n",(long long)SBuf.st_size - 1,
 742               TimeRFC1123(SBuf.st_mtime).c_str());
 743       Req += Buf;
 744    }
 745    else
 746    {
 747       if (Itm->LastModified != 0)
 748       {
 749          sprintf(Buf,"If-Modified-Since: %s\r\n",TimeRFC1123(Itm->LastModified).c_str());
 750          Req += Buf;
 751       }
 752    }
 753
 754    if (Proxy.User.empty() == false || Proxy.Password.empty() == false)
 755       Req += string("Proxy-Authorization: Basic ") +
 756           Base64Encode(Proxy.User + ":" + Proxy.Password) + "\r\n";
 757
 758    maybe_add_auth (Uri, _config->FindFile("Dir::Etc::netrc"));
 759    if (Uri.User.empty() == false || Uri.Password.empty() == false)
 760    {
 761       Req += string("Authorization: Basic ") +
 762           Base64Encode(Uri.User + ":" + Uri.Password) + "\r\n";
 763    }
 764    Req += "User-Agent: " + _config->Find("Acquire::http::User-Agent",
 765                 "Debian APT-HTTP/1.3 (" PACKAGE_VERSION ")") + "\r\n\r\n";
 766
 767    if (Debug == true)
 768       cerr << Req << endl;
 769
 770    Out.Read(Req);
 771 }
 772                                                                         /*}}}*/
 773 // HttpMethod::Go - Run a single loop                                   /*{{{*/
 774 // ---------------------------------------------------------------------
 775 /* This runs the select loop over the server FDs, Output file FDs and
 776    stdin. */
 777 bool HttpMethod::Go(bool ToFile,ServerState *Srv)
 778 {
 779    // Server has closed the connection
 780    if (Srv->ServerFd == -1 && (Srv->In.WriteSpace() == false ||
 781                                ToFile == false))
 782       return false;
 783
 784    fd_set rfds,wfds;
 785    FD_ZERO(&rfds);
 786    FD_ZERO(&wfds);
 787
 788    /* Add the server. We only send more requests if the connection will
 789       be persisting */
 790    if (Srv->Out.WriteSpace() == true && Srv->ServerFd != -1
 791        && Srv->Persistent == true)
 792       FD_SET(Srv->ServerFd,&wfds);
 793    if (Srv->In.ReadSpace() == true && Srv->ServerFd != -1)
 794       FD_SET(Srv->ServerFd,&rfds);
 795
 796    // Add the file
 797    int FileFD = -1;
 798    if (File != 0)
 799       FileFD = File->Fd();
 800
 801    if (Srv->In.WriteSpace() == true && ToFile == true && FileFD != -1)
 802       FD_SET(FileFD,&wfds);
 803
 804    // Add stdin
 805    if (_config->FindB("Acquire::http::DependOnSTDIN", true) == true)
 806       FD_SET(STDIN_FILENO,&rfds);
 807
 808    // Figure out the max fd
 809    int MaxFd = FileFD;
 810    if (MaxFd < Srv->ServerFd)
 811       MaxFd = Srv->ServerFd;
 812
 813    // Select
 814    struct timeval tv;
 815    tv.tv_sec = TimeOut;
 816    tv.tv_usec = 0;
 817    int Res = 0;
 818    if ((Res = select(MaxFd+1,&rfds,&wfds,0,&tv)) < 0)
 819    {
 820       if (errno == EINTR)
 821          return true;
 822       return _error->Errno("select",_("Select failed"));
 823    }
 824
 825    if (Res == 0)
 826    {
 827       _error->Error(_("Connection timed out"));
 828       return ServerDie(Srv);
 829    }
 830
 831    // Handle server IO
 832    if (Srv->ServerFd != -1 && FD_ISSET(Srv->ServerFd,&rfds))
 833    {
 834       errno = 0;
 835       if (Srv->In.Read(Srv->ServerFd) == false)
 836          return ServerDie(Srv);
 837    }
 838
 839    if (Srv->ServerFd != -1 && FD_ISSET(Srv->ServerFd,&wfds))
 840    {
 841       errno = 0;
 842       if (Srv->Out.Write(Srv->ServerFd) == false)
 843          return ServerDie(Srv);
 844    }
 845
 846    // Send data to the file
 847    if (FileFD != -1 && FD_ISSET(FileFD,&wfds))
 848    {
 849       if (Srv->In.Write(FileFD) == false)
 850          return _error->Errno("write",_("Error writing to output file"));
 851    }
 852
 853    // Handle commands from APT
 854    if (FD_ISSET(STDIN_FILENO,&rfds))
 855    {
 856       if (Run(true) != -1)
 857          exit(100);
 858    }
 859
 860    return true;
 861 }
 862                                                                         /*}}}*/
 863 // HttpMethod::Flush - Dump the buffer into the file                    /*{{{*/
 864 // ---------------------------------------------------------------------
 865 /* This takes the current input buffer from the Server FD and writes it
 866    into the file */
 867 bool HttpMethod::Flush(ServerState *Srv)
 868 {
 869    if (File != 0)
 870    {
 871       // on GNU/kFreeBSD, apt dies on /dev/null because non-blocking
 872       // can't be set
 873       if (File->Name() != "/dev/null")
 874          SetNonBlock(File->Fd(),false);
 875       if (Srv->In.WriteSpace() == false)
 876          return true;
 877
 878       while (Srv->In.WriteSpace() == true)
 879       {
 880          if (Srv->In.Write(File->Fd()) == false)
 881             return _error->Errno("write",_("Error writing to file"));
 882          if (Srv->In.IsLimit() == true)
 883             return true;
 884       }
 885
 886       if (Srv->In.IsLimit() == true || Srv->Encoding == ServerState::Closes)
 887          return true;
 888    }
 889    return false;
 890 }
 891                                                                         /*}}}*/
 892 // HttpMethod::ServerDie - The server has closed the connection.        /*{{{*/
 893 // ---------------------------------------------------------------------
 894 /* */
 895 bool HttpMethod::ServerDie(ServerState *Srv)
 896 {
 897    unsigned int LErrno = errno;
 898
 899    // Dump the buffer to the file
 900    if (Srv->State == ServerState::Data)
 901    {
 902       // on GNU/kFreeBSD, apt dies on /dev/null because non-blocking
 903       // can't be set
 904       if (File->Name() != "/dev/null")
 905          SetNonBlock(File->Fd(),false);
 906       while (Srv->In.WriteSpace() == true)
 907       {
 908          if (Srv->In.Write(File->Fd()) == false)
 909             return _error->Errno("write",_("Error writing to the file"));
 910
 911          // Done
 912          if (Srv->In.IsLimit() == true)
 913             return true;
 914       }
 915    }
 916
 917    // See if this is because the server finished the data stream
 918    if (Srv->In.IsLimit() == false && Srv->State != ServerState::Header &&
 919        Srv->Encoding != ServerState::Closes)
 920    {
 921       Srv->Close();
 922       if (LErrno == 0)
 923          return _error->Error(_("Error reading from server. Remote end closed connection"));
 924       errno = LErrno;
 925       return _error->Errno("read",_("Error reading from server"));
 926    }
 927    else
 928    {
 929       Srv->In.Limit(-1);
 930
 931       // Nothing left in the buffer
 932       if (Srv->In.WriteSpace() == false)
 933          return false;
 934
 935       // We may have got multiple responses back in one packet..
 936       Srv->Close();
 937       return true;
 938    }
 939
 940    return false;
 941 }
 942                                                                         /*}}}*/
 943 // HttpMethod::DealWithHeaders - Handle the retrieved header data       /*{{{*/
 944 // ---------------------------------------------------------------------
 945 /* We look at the header data we got back from the server and decide what
 946    to do. Returns DealWithHeadersResult (see http.h for details).
 947  */
 948 HttpMethod::DealWithHeadersResult
 949 HttpMethod::DealWithHeaders(FetchResult &Res,ServerState *Srv)
 950 {
 951    // Not Modified
 952    if (Srv->Result == 304)
 953    {
 954       unlink(Queue->DestFile.c_str());
 955       Res.IMSHit = true;
 956       Res.LastModified = Queue->LastModified;
 957       return IMS_HIT;
 958    }
 959
 960    /* Redirect
 961     *
 962     * Note that it is only OK for us to treat all redirection the same
 963     * because we *always* use GET, not other HTTP methods.  There are
 964     * three redirection codes for which it is not appropriate that we
 965     * redirect.  Pass on those codes so the error handling kicks in.
 966     */
 967    if (AllowRedirect
 968        && (Srv->Result > 300 && Srv->Result < 400)
 969        && (Srv->Result != 300       // Multiple Choices
 970            && Srv->Result != 304    // Not Modified
 971            && Srv->Result != 306))  // (Not part of HTTP/1.1, reserved)
 972    {
 973       if (Srv->Location.empty() == true);
 974       else if (Srv->Location[0] == '/' && Queue->Uri.empty() == false)
 975       {
 976          URI Uri = Queue->Uri;
 977          if (Uri.Host.empty() == false)
 978          {
 979             if (Uri.Port != 0)
 980                strprintf(NextURI, "http://%s:%u", Uri.Host.c_str(), Uri.Port);
 981             else
 982                NextURI = "http://" + Uri.Host;
 983          }
 984          else
 985             NextURI.clear();
 986          NextURI.append(DeQuoteString(Srv->Location));
 987          return TRY_AGAIN_OR_REDIRECT;
 988       }
 989       else
 990       {
 991          NextURI = DeQuoteString(Srv->Location);
 992          URI tmpURI = NextURI;
 993          // Do not allow a redirection to switch protocol
 994          if (tmpURI.Access == "http")
 995             return TRY_AGAIN_OR_REDIRECT;
 996       }
 997       /* else pass through for error message */
 998    }
 999
1000    /* We have a reply we dont handle. This should indicate a perm server
1001       failure */
1002    if (Srv->Result < 200 || Srv->Result >= 300)
1003    {
1004       char err[255];
1005       snprintf(err,sizeof(err)-1,"HttpError%i",Srv->Result);
1006       SetFailReason(err);
1007       _error->Error("%u %s",Srv->Result,Srv->Code);
1008       if (Srv->HaveContent == true)
1009          return ERROR_WITH_CONTENT_PAGE;
1010       return ERROR_UNRECOVERABLE;
1011    }
1012
1013    // This is some sort of 2xx 'data follows' reply
1014    Res.LastModified = Srv->Date;
1015    Res.Size = Srv->Size;
1016
1017    // Open the file
1018    delete File;
1019    File = new FileFd(Queue->DestFile,FileFd::WriteAny);
1020    if (_error->PendingError() == true)
1021       return ERROR_NOT_FROM_SERVER;
1022
1023    FailFile = Queue->DestFile;
1024    FailFile.c_str();   // Make sure we dont do a malloc in the signal handler
1025    FailFd = File->Fd();
1026    FailTime = Srv->Date;
1027
1028    delete Srv->In.Hash;
1029    Srv->In.Hash = new Hashes;
1030
1031    // Set the expected size and read file for the hashes
1032    if (Srv->StartPos >= 0)
1033    {
1034       Res.ResumePoint = Srv->StartPos;
1035       File->Truncate(Srv->StartPos);
1036
1037       if (Srv->In.Hash->AddFD(*File,Srv->StartPos) == false)
1038       {
1039          _error->Errno("read",_("Problem hashing file"));
1040          return ERROR_NOT_FROM_SERVER;
1041       }
1042    }
1043
1044    SetNonBlock(File->Fd(),true);
1045    return FILE_IS_OPEN;
1046 }
1047                                                                         /*}}}*/
1048 // HttpMethod::SigTerm - Handle a fatal signal                          /*{{{*/
1049 // ---------------------------------------------------------------------
1050 /* This closes and timestamps the open file. This is neccessary to get
1051    resume behavoir on user abort */
1052 void HttpMethod::SigTerm(int)
1053 {
1054    if (FailFd == -1)
1055       _exit(100);
1056    close(FailFd);
1057
1058    // Timestamp
1059    struct utimbuf UBuf;
1060    UBuf.actime = FailTime;
1061    UBuf.modtime = FailTime;
1062    utime(FailFile.c_str(),&UBuf);
1063
1064    _exit(100);
1065 }
1066                                                                         /*}}}*/
1067 // HttpMethod::Fetch - Fetch an item                                    /*{{{*/
1068 // ---------------------------------------------------------------------
1069 /* This adds an item to the pipeline. We keep the pipeline at a fixed
1070    depth. */
1071 bool HttpMethod::Fetch(FetchItem *)
1072 {
1073    if (Server == 0)
1074       return true;
1075
1076    // Queue the requests
1077    int Depth = -1;
1078    for (FetchItem *I = Queue; I != 0 && Depth < (signed)PipelineDepth;
1079         I = I->Next, Depth++)
1080    {
1081       // If pipelining is disabled, we only queue 1 request
1082       if (Server->Pipeline == false && Depth >= 0)
1083          break;
1084
1085       // Make sure we stick with the same server
1086       if (Server->Comp(I->Uri) == false)
1087          break;
1088       if (QueueBack == I)
1089       {
1090          QueueBack = I->Next;
1091          SendReq(I,Server->Out);
1092          continue;
1093       }
1094    }
1095
1096    return true;
1097 };
1098                                                                         /*}}}*/
1099 // HttpMethod::Configuration - Handle a configuration message           /*{{{*/
1100 // ---------------------------------------------------------------------
1101 /* We stash the desired pipeline depth */
1102 bool HttpMethod::Configuration(string Message)
1103 {
1104    if (pkgAcqMethod::Configuration(Message) == false)
1105       return false;
1106
1107    AllowRedirect = _config->FindB("Acquire::http::AllowRedirect",true);
1108    TimeOut = _config->FindI("Acquire::http::Timeout",TimeOut);
1109    PipelineDepth = _config->FindI("Acquire::http::Pipeline-Depth",
1110                                   PipelineDepth);
1111    Debug = _config->FindB("Debug::Acquire::http",false);
1112    AutoDetectProxyCmd = _config->Find("Acquire::http::ProxyAutoDetect");
1113
1114    // Get the proxy to use
1115    AutoDetectProxy();
1116
1117    return true;
1118 }
1119                                                                         /*}}}*/
1120 // HttpMethod::Loop - Main loop                                         /*{{{*/
1121 // ---------------------------------------------------------------------
1122 /* */
1123 int HttpMethod::Loop()
1124 {
1125    typedef vector<string> StringVector;
1126    typedef vector<string>::iterator StringVectorIterator;
1127    map<string, StringVector> Redirected;
1128
1129    signal(SIGTERM,SigTerm);
1130    signal(SIGINT,SigTerm);
1131
1132    Server = 0;
1133
1134    int FailCounter = 0;
1135    while (1)
1136    {
1137       // We have no commands, wait for some to arrive
1138       if (Queue == 0)
1139       {
1140          if (WaitFd(STDIN_FILENO) == false)
1141             return 0;
1142       }
1143
1144       /* Run messages, we can accept 0 (no message) if we didn't
1145          do a WaitFd above.. Otherwise the FD is closed. */
1146       int Result = Run(true);
1147       if (Result != -1 && (Result != 0 || Queue == 0))
1148       {
1149          if(FailReason.empty() == false ||
1150             _config->FindB("Acquire::http::DependOnSTDIN", true) == true)
1151             return 100;
1152          else
1153             return 0;
1154       }
1155
1156       if (Queue == 0)
1157          continue;
1158
1159       // Connect to the server
1160       if (Server == 0 || Server->Comp(Queue->Uri) == false)
1161       {
1162          delete Server;
1163          Server = new ServerState(Queue->Uri,this);
1164       }
1165       /* If the server has explicitly said this is the last connection
1166          then we pre-emptively shut down the pipeline and tear down
1167          the connection. This will speed up HTTP/1.0 servers a tad
1168          since we don't have to wait for the close sequence to
1169          complete */
1170       if (Server->Persistent == false)
1171          Server->Close();
1172
1173       // Reset the pipeline
1174       if (Server->ServerFd == -1)
1175          QueueBack = Queue;
1176
1177       // Connnect to the host
1178       if (Server->Open() == false)
1179       {
1180          Fail(true);
1181          delete Server;
1182          Server = 0;
1183          continue;
1184       }
1185
1186       // Fill the pipeline.
1187       Fetch(0);
1188
1189       // Fetch the next URL header data from the server.
1190       switch (Server->RunHeaders())
1191       {
1192          case ServerState::RUN_HEADERS_OK:
1193          break;
1194
1195          // The header data is bad
1196          case ServerState::RUN_HEADERS_PARSE_ERROR:
1197          {
1198             _error->Error(_("Bad header data"));
1199             Fail(true);
1200             RotateDNS();
1201             continue;
1202          }
1203
1204          // The server closed a connection during the header get..
1205          default:
1206          case ServerState::RUN_HEADERS_IO_ERROR:
1207          {
1208             FailCounter++;
1209             _error->Discard();
1210             Server->Close();
1211             Server->Pipeline = false;
1212
1213             if (FailCounter >= 2)
1214             {
1215                Fail(_("Connection failed"),true);
1216                FailCounter = 0;
1217             }
1218
1219             RotateDNS();
1220             continue;
1221          }
1222       };
1223
1224       // Decide what to do.
1225       FetchResult Res;
1226       Res.Filename = Queue->DestFile;
1227       switch (DealWithHeaders(Res,Server))
1228       {
1229          // Ok, the file is Open
1230          case FILE_IS_OPEN:
1231          {
1232             URIStart(Res);
1233
1234             // Run the data
1235             bool Result =  Server->RunData();
1236
1237             /* If the server is sending back sizeless responses then fill in
1238                the size now */
1239             if (Res.Size == 0)
1240                Res.Size = File->Size();
1241
1242             // Close the file, destroy the FD object and timestamp it
1243             FailFd = -1;
1244             delete File;
1245             File = 0;
1246
1247             // Timestamp
1248             struct utimbuf UBuf;
1249             time(&UBuf.actime);
1250             UBuf.actime = Server->Date;
1251             UBuf.modtime = Server->Date;
1252             utime(Queue->DestFile.c_str(),&UBuf);
1253
1254             // Send status to APT
1255             if (Result == true)
1256             {
1257                Res.TakeHashes(*Server->In.Hash);
1258                URIDone(Res);
1259             }
1260             else
1261             {
1262                if (Server->ServerFd == -1)
1263                {
1264                   FailCounter++;
1265                   _error->Discard();
1266                   Server->Close();
1267
1268                   if (FailCounter >= 2)
1269                   {
1270                      Fail(_("Connection failed"),true);
1271                      FailCounter = 0;
1272                   }
1273
1274                   QueueBack = Queue;
1275                }
1276                else
1277                   Fail(true);
1278             }
1279             break;
1280          }
1281
1282          // IMS hit
1283          case IMS_HIT:
1284          {
1285             URIDone(Res);
1286             break;
1287          }
1288
1289          // Hard server error, not found or something
1290          case ERROR_UNRECOVERABLE:
1291          {
1292             Fail();
1293             break;
1294          }
1295
1296          // Hard internal error, kill the connection and fail
1297          case ERROR_NOT_FROM_SERVER:
1298          {
1299             delete File;
1300             File = 0;
1301
1302             Fail();
1303             RotateDNS();
1304             Server->Close();
1305             break;
1306          }
1307
1308          // We need to flush the data, the header is like a 404 w/ error text
1309          case ERROR_WITH_CONTENT_PAGE:
1310          {
1311             Fail();
1312
1313             // Send to content to dev/null
1314             File = new FileFd("/dev/null",FileFd::WriteExists);
1315             Server->RunData();
1316             delete File;
1317             File = 0;
1318             break;
1319          }
1320
1321          // Try again with a new URL
1322          case TRY_AGAIN_OR_REDIRECT:
1323          {
1324             // Clear rest of response if there is content
1325             if (Server->HaveContent)
1326             {
1327                File = new FileFd("/dev/null",FileFd::WriteExists);
1328                Server->RunData();
1329                delete File;
1330                File = 0;
1331             }
1332
1333             /* Detect redirect loops.  No more redirects are allowed
1334                after the same URI is seen twice in a queue item. */
1335             StringVector &R = Redirected[Queue->DestFile];
1336             bool StopRedirects = false;
1337             if (R.empty() == true)
1338                R.push_back(Queue->Uri);
1339             else if (R[0] == "STOP" || R.size() > 10)
1340                StopRedirects = true;
1341             else
1342             {
1343                for (StringVectorIterator I = R.begin(); I != R.end(); ++I)
1344                   if (Queue->Uri == *I)
1345                   {
1346                      R[0] = "STOP";
1347                      break;
1348                   }
1349
1350                R.push_back(Queue->Uri);
1351             }
1352
1353             if (StopRedirects == false)
1354                Redirect(NextURI);
1355             else
1356                Fail();
1357
1358             break;
1359          }
1360
1361          default:
1362          Fail(_("Internal error"));
1363          break;
1364       }
1365
1366       FailCounter = 0;
1367    }
1368
1369    return 0;
1370 }
1371                                                                         /*}}}*/
1372 // HttpMethod::AutoDetectProxy - auto detect proxy                      /*{{{*/
1373 // ---------------------------------------------------------------------
1374 /* */
1375 bool HttpMethod::AutoDetectProxy()
1376 {
1377    if (AutoDetectProxyCmd.empty())
1378       return true;
1379
1380    if (Debug)
1381       clog << "Using auto proxy detect command: " << AutoDetectProxyCmd << endl;
1382
1383    int Pipes[2] = {-1,-1};
1384    if (pipe(Pipes) != 0)
1385       return _error->Errno("pipe", "Failed to create Pipe");
1386
1387    pid_t Process = ExecFork();
1388    if (Process == 0)
1389    {
1390       close(Pipes[0]);
1391       dup2(Pipes[1],STDOUT_FILENO);
1392       SetCloseExec(STDOUT_FILENO,false);
1393
1394       const char *Args[2];
1395       Args[0] = AutoDetectProxyCmd.c_str();
1396       Args[1] = 0;
1397       execv(Args[0],(char **)Args);
1398       cerr << "Failed to exec method " << Args[0] << endl;
1399       _exit(100);
1400    }
1401    char buf[512];
1402    int InFd = Pipes[0];
1403    close(Pipes[1]);
1404    int res = read(InFd, buf, sizeof(buf));
1405    ExecWait(Process, "ProxyAutoDetect", true);
1406
1407    if (res < 0)
1408       return _error->Errno("read", "Failed to read");
1409    if (res == 0)
1410       return _error->Warning("ProxyAutoDetect returned no data");
1411
1412    // add trailing \0
1413    buf[res] = 0;
1414
1415    if (Debug)
1416       clog << "auto detect command returned: '" << buf << "'" << endl;
1417
1418    if (strstr(buf, "http://") == buf)
1419       _config->Set("Acquire::http::proxy", _strstrip(buf));
1420
1421    return true;
1422 }
1423                                                                         /*}}}*/
1424
1425