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 Aquire 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 <apt-pkg/fileutl.h>
  29 #include <apt-pkg/acquire-method.h>
  30 #include <apt-pkg/error.h>
  31 #include <apt-pkg/hashes.h>
  32
  33 #include <sys/stat.h>
  34 #include <sys/time.h>
  35 #include <utime.h>
  36 #include <unistd.h>
  37 #include <signal.h>
  38 #include <stdio.h>
  39 #include <errno.h>
  40 #include <string.h>
  41 #include <iostream>
  42 #include <apti18n.h>
  43
  44 // Internet stuff
  45 #include <netdb.h>
  46
  47 #include "config.h"
  48 #include "connect.h"
  49 #include "rfc2553emu.h"
  50 #include "http.h"
  51
  52                                                                         /*}}}*/
  53 using namespace std;
  54
  55 string HttpMethod::FailFile;
  56 int HttpMethod::FailFd = -1;
  57 time_t HttpMethod::FailTime = 0;
  58 unsigned long PipelineDepth = 8;
  59 unsigned long TimeOut = 120;
  60 bool Debug = false;
  61
  62 unsigned long CircleBuf::BwReadLimit=0;
  63 unsigned long CircleBuf::BwTickReadData=0;
  64 struct timeval CircleBuf::BwReadTick={0,0};
  65 const unsigned int CircleBuf::BW_HZ=10;
  66
  67 // CircleBuf::CircleBuf - Circular input buffer                         /*{{{*/
  68 // ---------------------------------------------------------------------
  69 /* */
  70 CircleBuf::CircleBuf(unsigned long Size) : Size(Size), Hash(0)
  71 {
  72    Buf = new unsigned char[Size];
  73    Reset();
  74
  75    CircleBuf::BwReadLimit = _config->FindI("Acquire::http::Dl-Limit",0)*1024;
  76 }
  77                                                                         /*}}}*/
  78 // CircleBuf::Reset - Reset to the default state                        /*{{{*/
  79 // ---------------------------------------------------------------------
  80 /* */
  81 void CircleBuf::Reset()
  82 {
  83    InP = 0;
  84    OutP = 0;
  85    StrPos = 0;
  86    MaxGet = (unsigned int)-1;
  87    OutQueue = string();
  88    if (Hash != 0)
  89    {
  90       delete Hash;
  91       Hash = new Hashes;
  92    }
  93 };
  94                                                                         /*}}}*/
  95 // CircleBuf::Read - Read from a FD into the circular buffer            /*{{{*/
  96 // ---------------------------------------------------------------------
  97 /* This fills up the buffer with as much data as is in the FD, assuming it
  98    is non-blocking.. */
  99 bool CircleBuf::Read(int Fd)
 100 {
 101    unsigned long BwReadMax;
 102
 103    while (1)
 104    {
 105       // Woops, buffer is full
 106       if (InP - OutP == Size)
 107          return true;
 108
 109       // what's left to read in this tick
 110       BwReadMax = CircleBuf::BwReadLimit/BW_HZ;
 111
 112       if(CircleBuf::BwReadLimit) {
 113          struct timeval now;
 114          gettimeofday(&now,0);
 115
 116          unsigned long d = (now.tv_sec-CircleBuf::BwReadTick.tv_sec)*1000000 +
 117             now.tv_usec-CircleBuf::BwReadTick.tv_usec;
 118          if(d > 1000000/BW_HZ) {
 119             CircleBuf::BwReadTick = now;
 120             CircleBuf::BwTickReadData = 0;
 121          }
 122
 123          if(CircleBuf::BwTickReadData >= BwReadMax) {
 124             usleep(1000000/BW_HZ);
 125             return true;
 126          }
 127       }
 128
 129       // Write the buffer segment
 130       int Res;
 131       if(CircleBuf::BwReadLimit) {
 132          Res = read(Fd,Buf + (InP%Size),
 133                     BwReadMax > LeftRead() ? LeftRead() : BwReadMax);
 134       } else
 135          Res = read(Fd,Buf + (InP%Size),LeftRead());
 136
 137       if(Res > 0 && BwReadLimit > 0)
 138          CircleBuf::BwTickReadData += Res;
 139
 140       if (Res == 0)
 141          return false;
 142       if (Res < 0)
 143       {
 144          if (errno == EAGAIN)
 145             return true;
 146          return false;
 147       }
 148
 149       if (InP == 0)
 150          gettimeofday(&Start,0);
 151       InP += Res;
 152    }
 153 }
 154                                                                         /*}}}*/
 155 // CircleBuf::Read - Put the string into the buffer                     /*{{{*/
 156 // ---------------------------------------------------------------------
 157 /* This will hold the string in and fill the buffer with it as it empties */
 158 bool CircleBuf::Read(string Data)
 159 {
 160    OutQueue += Data;
 161    FillOut();
 162    return true;
 163 }
 164                                                                         /*}}}*/
 165 // CircleBuf::FillOut - Fill the buffer from the output queue           /*{{{*/
 166 // ---------------------------------------------------------------------
 167 /* */
 168 void CircleBuf::FillOut()
 169 {
 170    if (OutQueue.empty() == true)
 171       return;
 172    while (1)
 173    {
 174       // Woops, buffer is full
 175       if (InP - OutP == Size)
 176          return;
 177
 178       // Write the buffer segment
 179       unsigned long Sz = LeftRead();
 180       if (OutQueue.length() - StrPos < Sz)
 181          Sz = OutQueue.length() - StrPos;
 182       memcpy(Buf + (InP%Size),OutQueue.c_str() + StrPos,Sz);
 183
 184       // Advance
 185       StrPos += Sz;
 186       InP += Sz;
 187       if (OutQueue.length() == StrPos)
 188       {
 189          StrPos = 0;
 190          OutQueue = "";
 191          return;
 192       }
 193    }
 194 }
 195                                                                         /*}}}*/
 196 // CircleBuf::Write - Write from the buffer into a FD                   /*{{{*/
 197 // ---------------------------------------------------------------------
 198 /* This empties the buffer into the FD. */
 199 bool CircleBuf::Write(int Fd)
 200 {
 201    while (1)
 202    {
 203       FillOut();
 204
 205       // Woops, buffer is empty
 206       if (OutP == InP)
 207          return true;
 208
 209       if (OutP == MaxGet)
 210          return true;
 211
 212       // Write the buffer segment
 213       int Res;
 214       Res = write(Fd,Buf + (OutP%Size),LeftWrite());
 215
 216       if (Res == 0)
 217          return false;
 218       if (Res < 0)
 219       {
 220          if (errno == EAGAIN)
 221             return true;
 222
 223          return false;
 224       }
 225
 226       if (Hash != 0)
 227          Hash->Add(Buf + (OutP%Size),Res);
 228
 229       OutP += Res;
 230    }
 231 }
 232                                                                         /*}}}*/
 233 // CircleBuf::WriteTillEl - Write from the buffer to a string           /*{{{*/
 234 // ---------------------------------------------------------------------
 235 /* This copies till the first empty line */
 236 bool CircleBuf::WriteTillEl(string &Data,bool Single)
 237 {
 238    // We cheat and assume it is unneeded to have more than one buffer load
 239    for (unsigned long I = OutP; I < InP; I++)
 240    {
 241       if (Buf[I%Size] != '\n')
 242          continue;
 243       ++I;
 244
 245       if (Single == false)
 246       {
 247          if (I < InP  && Buf[I%Size] == '\r')
 248             ++I;
 249          if (I >= InP || Buf[I%Size] != '\n')
 250             continue;
 251          ++I;
 252       }
 253
 254       Data = "";
 255       while (OutP < I)
 256       {
 257          unsigned long Sz = LeftWrite();
 258          if (Sz == 0)
 259             return false;
 260          if (I - OutP < Sz)
 261             Sz = I - OutP;
 262          Data += string((char *)(Buf + (OutP%Size)),Sz);
 263          OutP += Sz;
 264       }
 265       return true;
 266    }
 267    return false;
 268 }
 269                                                                         /*}}}*/
 270 // CircleBuf::Stats - Print out stats information                       /*{{{*/
 271 // ---------------------------------------------------------------------
 272 /* */
 273 void CircleBuf::Stats()
 274 {
 275    if (InP == 0)
 276       return;
 277
 278    struct timeval Stop;
 279    gettimeofday(&Stop,0);
 280 /*   float Diff = Stop.tv_sec - Start.tv_sec +
 281              (float)(Stop.tv_usec - Start.tv_usec)/1000000;
 282    clog << "Got " << InP << " in " << Diff << " at " << InP/Diff << endl;*/
 283 }
 284                                                                         /*}}}*/
 285
 286 // ServerState::ServerState - Constructor                               /*{{{*/
 287 // ---------------------------------------------------------------------
 288 /* */
 289 ServerState::ServerState(URI Srv,HttpMethod *Owner) : Owner(Owner),
 290                         In(64*1024), Out(4*1024),
 291                         ServerName(Srv)
 292 {
 293    Reset();
 294 }
 295                                                                         /*}}}*/
 296 // ServerState::Open - Open a connection to the server                  /*{{{*/
 297 // ---------------------------------------------------------------------
 298 /* This opens a connection to the server. */
 299 bool ServerState::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    if (getenv("http_proxy") == 0)
 312    {
 313       string DefProxy = _config->Find("Acquire::http::Proxy");
 314       string SpecificProxy = _config->Find("Acquire::http::Proxy::" + ServerName.Host);
 315       if (SpecificProxy.empty() == false)
 316       {
 317          if (SpecificProxy == "DIRECT")
 318             Proxy = "";
 319          else
 320             Proxy = SpecificProxy;
 321       }
 322       else
 323          Proxy = DefProxy;
 324    }
 325    else
 326       Proxy = getenv("http_proxy");
 327
 328    // Parse no_proxy, a , separated list of domains
 329    if (getenv("no_proxy") != 0)
 330    {
 331       if (CheckDomainList(ServerName.Host,getenv("no_proxy")) == true)
 332          Proxy = "";
 333    }
 334
 335    // Determine what host and port to use based on the proxy settings
 336    int Port = 0;
 337    string Host;
 338    if (Proxy.empty() == true || Proxy.Host.empty() == true)
 339    {
 340       if (ServerName.Port != 0)
 341          Port = ServerName.Port;
 342       Host = ServerName.Host;
 343    }
 344    else
 345    {
 346       if (Proxy.Port != 0)
 347          Port = Proxy.Port;
 348       Host = Proxy.Host;
 349    }
 350
 351    // Connect to the remote server
 352    if (Connect(Host,Port,"http",80,ServerFd,TimeOut,Owner) == false)
 353       return false;
 354
 355    return true;
 356 }
 357                                                                         /*}}}*/
 358 // ServerState::Close - Close a connection to the server                /*{{{*/
 359 // ---------------------------------------------------------------------
 360 /* */
 361 bool ServerState::Close()
 362 {
 363    close(ServerFd);
 364    ServerFd = -1;
 365    return true;
 366 }
 367                                                                         /*}}}*/
 368 // ServerState::RunHeaders - Get the headers before the data            /*{{{*/
 369 // ---------------------------------------------------------------------
 370 /* Returns 0 if things are OK, 1 if an IO error occursed and 2 if a header
 371    parse error occured */
 372 int ServerState::RunHeaders()
 373 {
 374    State = Header;
 375
 376    Owner->Status(_("Waiting for headers"));
 377
 378    Major = 0;
 379    Minor = 0;
 380    Result = 0;
 381    Size = 0;
 382    StartPos = 0;
 383    Encoding = Closes;
 384    HaveContent = false;
 385    time(&Date);
 386
 387    do
 388    {
 389       string Data;
 390       if (In.WriteTillEl(Data) == false)
 391          continue;
 392
 393       if (Debug == true)
 394          clog << Data;
 395
 396       for (string::const_iterator I = Data.begin(); I < Data.end(); I++)
 397       {
 398          string::const_iterator J = I;
 399          for (; J != Data.end() && *J != '\n' && *J != '\r';J++);
 400          if (HeaderLine(string(I,J)) == false)
 401             return 2;
 402          I = J;
 403       }
 404
 405       // 100 Continue is a Nop...
 406       if (Result == 100)
 407          continue;
 408
 409       // Tidy up the connection persistance state.
 410       if (Encoding == Closes && HaveContent == true)
 411          Persistent = false;
 412
 413       return 0;
 414    }
 415    while (Owner->Go(false,this) == true);
 416
 417    return 1;
 418 }
 419                                                                         /*}}}*/
 420 // ServerState::RunData - Transfer the data from the socket             /*{{{*/
 421 // ---------------------------------------------------------------------
 422 /* */
 423 bool ServerState::RunData()
 424 {
 425    State = Data;
 426
 427    // Chunked transfer encoding is fun..
 428    if (Encoding == Chunked)
 429    {
 430       while (1)
 431       {
 432          // Grab the block size
 433          bool Last = true;
 434          string Data;
 435          In.Limit(-1);
 436          do
 437          {
 438             if (In.WriteTillEl(Data,true) == true)
 439                break;
 440          }
 441          while ((Last = Owner->Go(false,this)) == true);
 442
 443          if (Last == false)
 444             return false;
 445
 446          // See if we are done
 447          unsigned long Len = strtol(Data.c_str(),0,16);
 448          if (Len == 0)
 449          {
 450             In.Limit(-1);
 451
 452             // We have to remove the entity trailer
 453             Last = true;
 454             do
 455             {
 456                if (In.WriteTillEl(Data,true) == true && Data.length() <= 2)
 457                   break;
 458             }
 459             while ((Last = Owner->Go(false,this)) == true);
 460             if (Last == false)
 461                return false;
 462             return !_error->PendingError();
 463          }
 464
 465          // Transfer the block
 466          In.Limit(Len);
 467          while (Owner->Go(true,this) == true)
 468             if (In.IsLimit() == true)
 469                break;
 470
 471          // Error
 472          if (In.IsLimit() == false)
 473             return false;
 474
 475          // The server sends an extra new line before the next block specifier..
 476          In.Limit(-1);
 477          Last = true;
 478          do
 479          {
 480             if (In.WriteTillEl(Data,true) == true)
 481                break;
 482          }
 483          while ((Last = Owner->Go(false,this)) == true);
 484          if (Last == false)
 485             return false;
 486       }
 487    }
 488    else
 489    {
 490       /* Closes encoding is used when the server did not specify a size, the
 491          loss of the connection means we are done */
 492       if (Encoding == Closes)
 493          In.Limit(-1);
 494       else
 495          In.Limit(Size - StartPos);
 496
 497       // Just transfer the whole block.
 498       do
 499       {
 500          if (In.IsLimit() == false)
 501             continue;
 502
 503          In.Limit(-1);
 504          return !_error->PendingError();
 505       }
 506       while (Owner->Go(true,this) == true);
 507    }
 508
 509    return Owner->Flush(this) && !_error->PendingError();
 510 }
 511                                                                         /*}}}*/
 512 // ServerState::HeaderLine - Process a header line                      /*{{{*/
 513 // ---------------------------------------------------------------------
 514 /* */
 515 bool ServerState::HeaderLine(string Line)
 516 {
 517    if (Line.empty() == true)
 518       return true;
 519
 520    // The http server might be trying to do something evil.
 521    if (Line.length() >= MAXLEN)
 522       return _error->Error(_("Got a single header line over %u chars"),MAXLEN);
 523
 524    string::size_type Pos = Line.find(' ');
 525    if (Pos == string::npos || Pos+1 > Line.length())
 526    {
 527       // Blah, some servers use "connection:closes", evil.
 528       Pos = Line.find(':');
 529       if (Pos == string::npos || Pos + 2 > Line.length())
 530          return _error->Error(_("Bad header line"));
 531       Pos++;
 532    }
 533
 534    // Parse off any trailing spaces between the : and the next word.
 535    string::size_type Pos2 = Pos;
 536    while (Pos2 < Line.length() && isspace(Line[Pos2]) != 0)
 537       Pos2++;
 538
 539    string Tag = string(Line,0,Pos);
 540    string Val = string(Line,Pos2);
 541
 542    if (stringcasecmp(Tag.c_str(),Tag.c_str()+4,"HTTP") == 0)
 543    {
 544       // Evil servers return no version
 545       if (Line[4] == '/')
 546       {
 547          if (sscanf(Line.c_str(),"HTTP/%u.%u %u %[^\n]",&Major,&Minor,
 548                     &Result,Code) != 4)
 549             return _error->Error(_("The HTTP server sent an invalid reply header"));
 550       }
 551       else
 552       {
 553          Major = 0;
 554          Minor = 9;
 555          if (sscanf(Line.c_str(),"HTTP %u %[^\n]",&Result,Code) != 2)
 556             return _error->Error(_("The HTTP server sent an invalid reply header"));
 557       }
 558
 559       /* Check the HTTP response header to get the default persistance
 560          state. */
 561       if (Major < 1)
 562          Persistent = false;
 563       else
 564       {
 565          if (Major == 1 && Minor <= 0)
 566             Persistent = false;
 567          else
 568             Persistent = true;
 569       }
 570
 571       return true;
 572    }
 573
 574    if (stringcasecmp(Tag,"Content-Length:") == 0)
 575    {
 576       if (Encoding == Closes)
 577          Encoding = Stream;
 578       HaveContent = true;
 579
 580       // The length is already set from the Content-Range header
 581       if (StartPos != 0)
 582          return true;
 583
 584       if (sscanf(Val.c_str(),"%lu",&Size) != 1)
 585          return _error->Error(_("The HTTP server sent an invalid Content-Length header"));
 586       return true;
 587    }
 588
 589    if (stringcasecmp(Tag,"Content-Type:") == 0)
 590    {
 591       HaveContent = true;
 592       return true;
 593    }
 594
 595    if (stringcasecmp(Tag,"Content-Range:") == 0)
 596    {
 597       HaveContent = true;
 598
 599       if (sscanf(Val.c_str(),"bytes %lu-%*u/%lu",&StartPos,&Size) != 2)
 600          return _error->Error(_("The HTTP server sent an invalid Content-Range header"));
 601       if ((unsigned)StartPos > Size)
 602          return _error->Error(_("This HTTP server has broken range support"));
 603       return true;
 604    }
 605
 606    if (stringcasecmp(Tag,"Transfer-Encoding:") == 0)
 607    {
 608       HaveContent = true;
 609       if (stringcasecmp(Val,"chunked") == 0)
 610          Encoding = Chunked;
 611       return true;
 612    }
 613
 614    if (stringcasecmp(Tag,"Connection:") == 0)
 615    {
 616       if (stringcasecmp(Val,"close") == 0)
 617          Persistent = false;
 618       if (stringcasecmp(Val,"keep-alive") == 0)
 619          Persistent = true;
 620       return true;
 621    }
 622
 623    if (stringcasecmp(Tag,"Last-Modified:") == 0)
 624    {
 625       if (StrToTime(Val,Date) == false)
 626          return _error->Error(_("Unknown date format"));
 627       return true;
 628    }
 629
 630    return true;
 631 }
 632                                                                         /*}}}*/
 633
 634 // HttpMethod::SendReq - Send the HTTP request                          /*{{{*/
 635 // ---------------------------------------------------------------------
 636 /* This places the http request in the outbound buffer */
 637 void HttpMethod::SendReq(FetchItem *Itm,CircleBuf &Out)
 638 {
 639    URI Uri = Itm->Uri;
 640
 641    // The HTTP server expects a hostname with a trailing :port
 642    char Buf[1000];
 643    string ProperHost = Uri.Host;
 644    if (Uri.Port != 0)
 645    {
 646       sprintf(Buf,":%u",Uri.Port);
 647       ProperHost += Buf;
 648    }
 649
 650    // Just in case.
 651    if (Itm->Uri.length() >= sizeof(Buf))
 652        abort();
 653
 654    /* Build the request. We include a keep-alive header only for non-proxy
 655       requests. This is to tweak old http/1.0 servers that do support keep-alive
 656       but not HTTP/1.1 automatic keep-alive. Doing this with a proxy server
 657       will glitch HTTP/1.0 proxies because they do not filter it out and
 658       pass it on, HTTP/1.1 says the connection should default to keep alive
 659       and we expect the proxy to do this */
 660    if (Proxy.empty() == true || Proxy.Host.empty())
 661       sprintf(Buf,"GET %s HTTP/1.1\r\nHost: %s\r\nConnection: keep-alive\r\n",
 662               QuoteString(Uri.Path,"~").c_str(),ProperHost.c_str());
 663    else
 664    {
 665       /* Generate a cache control header if necessary. We place a max
 666          cache age on index files, optionally set a no-cache directive
 667          and a no-store directive for archives. */
 668       sprintf(Buf,"GET %s HTTP/1.1\r\nHost: %s\r\n",
 669               Itm->Uri.c_str(),ProperHost.c_str());
 670       // only generate a cache control header if we actually want to
 671       // use a cache
 672       if (_config->FindB("Acquire::http::No-Cache",false) == false)
 673       {
 674          if (Itm->IndexFile == true)
 675             sprintf(Buf+strlen(Buf),"Cache-Control: max-age=%u\r\n",
 676                     _config->FindI("Acquire::http::Max-Age",0));
 677          else
 678          {
 679             if (_config->FindB("Acquire::http::No-Store",false) == true)
 680                strcat(Buf,"Cache-Control: no-store\r\n");
 681          }
 682       }
 683    }
 684    // generate a no-cache header if needed
 685    if (_config->FindB("Acquire::http::No-Cache",false) == true)
 686       strcat(Buf,"Cache-Control: no-cache\r\nPragma: no-cache\r\n");
 687
 688
 689    string Req = Buf;
 690
 691    // Check for a partial file
 692    struct stat SBuf;
 693    if (stat(Itm->DestFile.c_str(),&SBuf) >= 0 && SBuf.st_size > 0)
 694    {
 695       // In this case we send an if-range query with a range header
 696       sprintf(Buf,"Range: bytes=%li-\r\nIf-Range: %s\r\n",(long)SBuf.st_size - 1,
 697               TimeRFC1123(SBuf.st_mtime).c_str());
 698       Req += Buf;
 699    }
 700    else
 701    {
 702       if (Itm->LastModified != 0)
 703       {
 704          sprintf(Buf,"If-Modified-Since: %s\r\n",TimeRFC1123(Itm->LastModified).c_str());
 705          Req += Buf;
 706       }
 707    }
 708
 709    if (Proxy.User.empty() == false || Proxy.Password.empty() == false)
 710       Req += string("Proxy-Authorization: Basic ") +
 711           Base64Encode(Proxy.User + ":" + Proxy.Password) + "\r\n";
 712
 713    if (Uri.User.empty() == false || Uri.Password.empty() == false)
 714       Req += string("Authorization: Basic ") +
 715           Base64Encode(Uri.User + ":" + Uri.Password) + "\r\n";
 716
 717    Req += "User-Agent: Debian APT-HTTP/1.3 ("VERSION")\r\n\r\n";
 718
 719    if (Debug == true)
 720       cerr << Req << endl;
 721
 722    Out.Read(Req);
 723 }
 724                                                                         /*}}}*/
 725 // HttpMethod::Go - Run a single loop                                   /*{{{*/
 726 // ---------------------------------------------------------------------
 727 /* This runs the select loop over the server FDs, Output file FDs and
 728    stdin. */
 729 bool HttpMethod::Go(bool ToFile,ServerState *Srv)
 730 {
 731    // Server has closed the connection
 732    if (Srv->ServerFd == -1 && (Srv->In.WriteSpace() == false ||
 733                                ToFile == false))
 734       return false;
 735
 736    fd_set rfds,wfds;
 737    FD_ZERO(&rfds);
 738    FD_ZERO(&wfds);
 739
 740    /* Add the server. We only send more requests if the connection will
 741       be persisting */
 742    if (Srv->Out.WriteSpace() == true && Srv->ServerFd != -1
 743        && Srv->Persistent == true)
 744       FD_SET(Srv->ServerFd,&wfds);
 745    if (Srv->In.ReadSpace() == true && Srv->ServerFd != -1)
 746       FD_SET(Srv->ServerFd,&rfds);
 747
 748    // Add the file
 749    int FileFD = -1;
 750    if (File != 0)
 751       FileFD = File->Fd();
 752
 753    if (Srv->In.WriteSpace() == true && ToFile == true && FileFD != -1)
 754       FD_SET(FileFD,&wfds);
 755
 756    // Add stdin
 757    FD_SET(STDIN_FILENO,&rfds);
 758
 759    // Figure out the max fd
 760    int MaxFd = FileFD;
 761    if (MaxFd < Srv->ServerFd)
 762       MaxFd = Srv->ServerFd;
 763
 764    // Select
 765    struct timeval tv;
 766    tv.tv_sec = TimeOut;
 767    tv.tv_usec = 0;
 768    int Res = 0;
 769    if ((Res = select(MaxFd+1,&rfds,&wfds,0,&tv)) < 0)
 770    {
 771       if (errno == EINTR)
 772          return true;
 773       return _error->Errno("select",_("Select failed"));
 774    }
 775
 776    if (Res == 0)
 777    {
 778       _error->Error(_("Connection timed out"));
 779       return ServerDie(Srv);
 780    }
 781
 782    // Handle server IO
 783    if (Srv->ServerFd != -1 && FD_ISSET(Srv->ServerFd,&rfds))
 784    {
 785       errno = 0;
 786       if (Srv->In.Read(Srv->ServerFd) == false)
 787          return ServerDie(Srv);
 788    }
 789
 790    if (Srv->ServerFd != -1 && FD_ISSET(Srv->ServerFd,&wfds))
 791    {
 792       errno = 0;
 793       if (Srv->Out.Write(Srv->ServerFd) == false)
 794          return ServerDie(Srv);
 795    }
 796
 797    // Send data to the file
 798    if (FileFD != -1 && FD_ISSET(FileFD,&wfds))
 799    {
 800       if (Srv->In.Write(FileFD) == false)
 801          return _error->Errno("write",_("Error writing to output file"));
 802    }
 803
 804    // Handle commands from APT
 805    if (FD_ISSET(STDIN_FILENO,&rfds))
 806    {
 807       if (Run(true) != -1)
 808          exit(100);
 809    }
 810
 811    return true;
 812 }
 813                                                                         /*}}}*/
 814 // HttpMethod::Flush - Dump the buffer into the file                    /*{{{*/
 815 // ---------------------------------------------------------------------
 816 /* This takes the current input buffer from the Server FD and writes it
 817    into the file */
 818 bool HttpMethod::Flush(ServerState *Srv)
 819 {
 820    if (File != 0)
 821    {
 822       // on GNU/kFreeBSD, apt dies on /dev/null because non-blocking
 823       // can't be set
 824       if (File->Name() != "/dev/null")
 825          SetNonBlock(File->Fd(),false);
 826       if (Srv->In.WriteSpace() == false)
 827          return true;
 828
 829       while (Srv->In.WriteSpace() == true)
 830       {
 831          if (Srv->In.Write(File->Fd()) == false)
 832             return _error->Errno("write",_("Error writing to file"));
 833          if (Srv->In.IsLimit() == true)
 834             return true;
 835       }
 836
 837       if (Srv->In.IsLimit() == true || Srv->Encoding == ServerState::Closes)
 838          return true;
 839    }
 840    return false;
 841 }
 842                                                                         /*}}}*/
 843 // HttpMethod::ServerDie - The server has closed the connection.        /*{{{*/
 844 // ---------------------------------------------------------------------
 845 /* */
 846 bool HttpMethod::ServerDie(ServerState *Srv)
 847 {
 848    unsigned int LErrno = errno;
 849
 850    // Dump the buffer to the file
 851    if (Srv->State == ServerState::Data)
 852    {
 853       // on GNU/kFreeBSD, apt dies on /dev/null because non-blocking
 854       // can't be set
 855       if (File->Name() != "/dev/null")
 856          SetNonBlock(File->Fd(),false);
 857       while (Srv->In.WriteSpace() == true)
 858       {
 859          if (Srv->In.Write(File->Fd()) == false)
 860             return _error->Errno("write",_("Error writing to the file"));
 861
 862          // Done
 863          if (Srv->In.IsLimit() == true)
 864             return true;
 865       }
 866    }
 867
 868    // See if this is because the server finished the data stream
 869    if (Srv->In.IsLimit() == false && Srv->State != ServerState::Header &&
 870        Srv->Encoding != ServerState::Closes)
 871    {
 872       Srv->Close();
 873       if (LErrno == 0)
 874          return _error->Error(_("Error reading from server. Remote end closed connection"));
 875       errno = LErrno;
 876       return _error->Errno("read",_("Error reading from server"));
 877    }
 878    else
 879    {
 880       Srv->In.Limit(-1);
 881
 882       // Nothing left in the buffer
 883       if (Srv->In.WriteSpace() == false)
 884          return false;
 885
 886       // We may have got multiple responses back in one packet..
 887       Srv->Close();
 888       return true;
 889    }
 890
 891    return false;
 892 }
 893                                                                         /*}}}*/
 894 // HttpMethod::DealWithHeaders - Handle the retrieved header data       /*{{{*/
 895 // ---------------------------------------------------------------------
 896 /* We look at the header data we got back from the server and decide what
 897    to do. Returns
 898      0 - File is open,
 899      1 - IMS hit
 900      3 - Unrecoverable error
 901      4 - Error with error content page
 902      5 - Unrecoverable non-server error (close the connection) */
 903 int HttpMethod::DealWithHeaders(FetchResult &Res,ServerState *Srv)
 904 {
 905    // Not Modified
 906    if (Srv->Result == 304)
 907    {
 908       unlink(Queue->DestFile.c_str());
 909       Res.IMSHit = true;
 910       Res.LastModified = Queue->LastModified;
 911       return 1;
 912    }
 913
 914    /* We have a reply we dont handle. This should indicate a perm server
 915       failure */
 916    if (Srv->Result < 200 || Srv->Result >= 300)
 917    {
 918       _error->Error("%u %s",Srv->Result,Srv->Code);
 919       if (Srv->HaveContent == true)
 920          return 4;
 921       return 3;
 922    }
 923
 924    // This is some sort of 2xx 'data follows' reply
 925    Res.LastModified = Srv->Date;
 926    Res.Size = Srv->Size;
 927
 928    // Open the file
 929    delete File;
 930    File = new FileFd(Queue->DestFile,FileFd::WriteAny);
 931    if (_error->PendingError() == true)
 932       return 5;
 933
 934    FailFile = Queue->DestFile;
 935    FailFile.c_str();   // Make sure we dont do a malloc in the signal handler
 936    FailFd = File->Fd();
 937    FailTime = Srv->Date;
 938
 939    // Set the expected size
 940    if (Srv->StartPos >= 0)
 941    {
 942       Res.ResumePoint = Srv->StartPos;
 943       ftruncate(File->Fd(),Srv->StartPos);
 944    }
 945
 946    // Set the start point
 947    lseek(File->Fd(),0,SEEK_END);
 948
 949    delete Srv->In.Hash;
 950    Srv->In.Hash = new Hashes;
 951
 952    // Fill the Hash if the file is non-empty (resume)
 953    if (Srv->StartPos > 0)
 954    {
 955       lseek(File->Fd(),0,SEEK_SET);
 956       if (Srv->In.Hash->AddFD(File->Fd(),Srv->StartPos) == false)
 957       {
 958          _error->Errno("read",_("Problem hashing file"));
 959          return 5;
 960       }
 961       lseek(File->Fd(),0,SEEK_END);
 962    }
 963
 964    SetNonBlock(File->Fd(),true);
 965    return 0;
 966 }
 967                                                                         /*}}}*/
 968 // HttpMethod::SigTerm - Handle a fatal signal                          /*{{{*/
 969 // ---------------------------------------------------------------------
 970 /* This closes and timestamps the open file. This is neccessary to get
 971    resume behavoir on user abort */
 972 void HttpMethod::SigTerm(int)
 973 {
 974    if (FailFd == -1)
 975       _exit(100);
 976    close(FailFd);
 977
 978    // Timestamp
 979    struct utimbuf UBuf;
 980    UBuf.actime = FailTime;
 981    UBuf.modtime = FailTime;
 982    utime(FailFile.c_str(),&UBuf);
 983
 984    _exit(100);
 985 }
 986                                                                         /*}}}*/
 987 // HttpMethod::Fetch - Fetch an item                                    /*{{{*/
 988 // ---------------------------------------------------------------------
 989 /* This adds an item to the pipeline. We keep the pipeline at a fixed
 990    depth. */
 991 bool HttpMethod::Fetch(FetchItem *)
 992 {
 993    if (Server == 0)
 994       return true;
 995
 996    // Queue the requests
 997    int Depth = -1;
 998    bool Tail = false;
 999    for (FetchItem *I = Queue; I != 0 && Depth < (signed)PipelineDepth;
1000         I = I->Next, Depth++)
1001    {
1002       // If pipelining is disabled, we only queue 1 request
1003       if (Server->Pipeline == false && Depth >= 0)
1004          break;
1005
1006       // Make sure we stick with the same server
1007       if (Server->Comp(I->Uri) == false)
1008          break;
1009       if (QueueBack == I)
1010          Tail = true;
1011       if (Tail == true)
1012       {
1013          QueueBack = I->Next;
1014          SendReq(I,Server->Out);
1015          continue;
1016       }
1017    }
1018
1019    return true;
1020 };
1021                                                                         /*}}}*/
1022 // HttpMethod::Configuration - Handle a configuration message           /*{{{*/
1023 // ---------------------------------------------------------------------
1024 /* We stash the desired pipeline depth */
1025 bool HttpMethod::Configuration(string Message)
1026 {
1027    if (pkgAcqMethod::Configuration(Message) == false)
1028       return false;
1029
1030    TimeOut = _config->FindI("Acquire::http::Timeout",TimeOut);
1031    PipelineDepth = _config->FindI("Acquire::http::Pipeline-Depth",
1032                                   PipelineDepth);
1033    Debug = _config->FindB("Debug::Acquire::http",false);
1034
1035    return true;
1036 }
1037                                                                         /*}}}*/
1038 // HttpMethod::Loop - Main loop                                         /*{{{*/
1039 // ---------------------------------------------------------------------
1040 /* */
1041 int HttpMethod::Loop()
1042 {
1043    signal(SIGTERM,SigTerm);
1044    signal(SIGINT,SigTerm);
1045
1046    Server = 0;
1047
1048    int FailCounter = 0;
1049    while (1)
1050    {
1051       // We have no commands, wait for some to arrive
1052       if (Queue == 0)
1053       {
1054          if (WaitFd(STDIN_FILENO) == false)
1055             return 0;
1056       }
1057
1058       /* Run messages, we can accept 0 (no message) if we didn't
1059          do a WaitFd above.. Otherwise the FD is closed. */
1060       int Result = Run(true);
1061       if (Result != -1 && (Result != 0 || Queue == 0))
1062          return 100;
1063
1064       if (Queue == 0)
1065          continue;
1066
1067       // Connect to the server
1068       if (Server == 0 || Server->Comp(Queue->Uri) == false)
1069       {
1070          delete Server;
1071          Server = new ServerState(Queue->Uri,this);
1072       }
1073
1074       /* If the server has explicitly said this is the last connection
1075          then we pre-emptively shut down the pipeline and tear down
1076          the connection. This will speed up HTTP/1.0 servers a tad
1077          since we don't have to wait for the close sequence to
1078          complete */
1079       if (Server->Persistent == false)
1080          Server->Close();
1081
1082       // Reset the pipeline
1083       if (Server->ServerFd == -1)
1084          QueueBack = Queue;
1085
1086       // Connnect to the host
1087       if (Server->Open() == false)
1088       {
1089          Fail(true);
1090          delete Server;
1091          Server = 0;
1092          continue;
1093       }
1094
1095       // Fill the pipeline.
1096       Fetch(0);
1097
1098       // Fetch the next URL header data from the server.
1099       switch (Server->RunHeaders())
1100       {
1101          case 0:
1102          break;
1103
1104          // The header data is bad
1105          case 2:
1106          {
1107             _error->Error(_("Bad header data"));
1108             Fail(true);
1109             RotateDNS();
1110             continue;
1111          }
1112
1113          // The server closed a connection during the header get..
1114          default:
1115          case 1:
1116          {
1117             FailCounter++;
1118             _error->Discard();
1119             Server->Close();
1120             Server->Pipeline = false;
1121
1122             if (FailCounter >= 2)
1123             {
1124                Fail(_("Connection failed"),true);
1125                FailCounter = 0;
1126             }
1127
1128             RotateDNS();
1129             continue;
1130          }
1131       };
1132
1133       // Decide what to do.
1134       FetchResult Res;
1135       Res.Filename = Queue->DestFile;
1136       switch (DealWithHeaders(Res,Server))
1137       {
1138          // Ok, the file is Open
1139          case 0:
1140          {
1141             URIStart(Res);
1142
1143             // Run the data
1144             bool Result =  Server->RunData();
1145
1146             /* If the server is sending back sizeless responses then fill in
1147                the size now */
1148             if (Res.Size == 0)
1149                Res.Size = File->Size();
1150
1151             // Close the file, destroy the FD object and timestamp it
1152             FailFd = -1;
1153             delete File;
1154             File = 0;
1155
1156             // Timestamp
1157             struct utimbuf UBuf;
1158             time(&UBuf.actime);
1159             UBuf.actime = Server->Date;
1160             UBuf.modtime = Server->Date;
1161             utime(Queue->DestFile.c_str(),&UBuf);
1162
1163             // Send status to APT
1164             if (Result == true)
1165             {
1166                Res.TakeHashes(*Server->In.Hash);
1167                URIDone(Res);
1168             }
1169             else
1170                Fail(true);
1171
1172             break;
1173          }
1174
1175          // IMS hit
1176          case 1:
1177          {
1178             URIDone(Res);
1179             break;
1180          }
1181
1182          // Hard server error, not found or something
1183          case 3:
1184          {
1185             Fail();
1186             break;
1187          }
1188
1189          // Hard internal error, kill the connection and fail
1190          case 5:
1191          {
1192             delete File;
1193             File = 0;
1194
1195             Fail();
1196             RotateDNS();
1197             Server->Close();
1198             break;
1199          }
1200
1201          // We need to flush the data, the header is like a 404 w/ error text
1202          case 4:
1203          {
1204             Fail();
1205
1206             // Send to content to dev/null
1207             File = new FileFd("/dev/null",FileFd::WriteExists);
1208             Server->RunData();
1209             delete File;
1210             File = 0;
1211             break;
1212          }
1213
1214          default:
1215          Fail(_("Internal error"));
1216          break;
1217       }
1218
1219       FailCounter = 0;
1220    }
1221
1222    return 0;
1223 }
1224                                                                         /*}}}*/
1225
1226 int main()
1227 {
1228    setlocale(LC_ALL, "");
1229
1230    HttpMethod Mth;
1231
1232    return Mth.Loop();
1233 }
1234
1235