apt-pkg/contrib/fileutl.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /* ######################################################################
   4
   5    File Utilities
   6
   7    CopyFile - Buffered copy of a single file
   8    GetLock - dpkg compatible lock file manipulation (fcntl)
   9
  10    Most of this source is placed in the Public Domain, do with it what
  11    you will
  12    It was originally written by Jason Gunthorpe <jgg@debian.org>.
  13    FileFd gzip support added by Martin Pitt <martin.pitt@canonical.com>
  14
  15    The exception is RunScripts() it is under the GPLv2
  16
  17    ##################################################################### */
  18                                                                         /*}}}*/
  19 // Include Files                                                        /*{{{*/
  20 #include <config.h>
  21
  22 #include <apt-pkg/fileutl.h>
  23 #include <apt-pkg/strutl.h>
  24 #include <apt-pkg/error.h>
  25 #include <apt-pkg/sptr.h>
  26 #include <apt-pkg/aptconfiguration.h>
  27 #include <apt-pkg/configuration.h>
  28 #include <apt-pkg/macros.h>
  29
  30 #include <ctype.h>
  31 #include <stdarg.h>
  32 #include <stddef.h>
  33 #include <sys/select.h>
  34 #include <time.h>
  35 #include <string>
  36 #include <vector>
  37 #include <cstdlib>
  38 #include <cstring>
  39 #include <cstdio>
  40 #include <iostream>
  41 #include <unistd.h>
  42 #include <fcntl.h>
  43 #include <sys/stat.h>
  44 #include <sys/time.h>
  45 #include <sys/wait.h>
  46 #include <dirent.h>
  47 #include <signal.h>
  48 #include <errno.h>
  49 #include <glob.h>
  50 #include <pwd.h>
  51 #include <grp.h>
  52
  53 #include <set>
  54 #include <algorithm>
  55
  56 #ifdef HAVE_ZLIB
  57         #include <zlib.h>
  58 #endif
  59 #ifdef HAVE_BZ2
  60         #include <bzlib.h>
  61 #endif
  62 #ifdef HAVE_LZMA
  63         #include <lzma.h>
  64 #endif
  65 #include <endian.h>
  66 #include <stdint.h>
  67
  68 #if __gnu_linux__
  69 #include <sys/prctl.h>
  70 #endif
  71
  72 #include <apti18n.h>
  73                                                                         /*}}}*/
  74
  75 using namespace std;
  76
  77 // RunScripts - Run a set of scripts from a configuration subtree       /*{{{*/
  78 // ---------------------------------------------------------------------
  79 /* */
  80 bool RunScripts(const char *Cnf)
  81 {
  82    Configuration::Item const *Opts = _config->Tree(Cnf);
  83    if (Opts == 0 || Opts->Child == 0)
  84       return true;
  85    Opts = Opts->Child;
  86
  87    // Fork for running the system calls
  88    pid_t Child = ExecFork();
  89
  90    // This is the child
  91    if (Child == 0)
  92    {
  93       if (_config->FindDir("DPkg::Chroot-Directory","/") != "/")
  94       {
  95          std::cerr << "Chrooting into "
  96                    << _config->FindDir("DPkg::Chroot-Directory")
  97                    << std::endl;
  98          if (chroot(_config->FindDir("DPkg::Chroot-Directory","/").c_str()) != 0)
  99             _exit(100);
 100       }
 101
 102       if (chdir("/tmp/") != 0)
 103          _exit(100);
 104
 105       unsigned int Count = 1;
 106       for (; Opts != 0; Opts = Opts->Next, Count++)
 107       {
 108          if (Opts->Value.empty() == true)
 109             continue;
 110
 111          if(_config->FindB("Debug::RunScripts", false) == true)
 112             std::clog << "Running external script: '"
 113                       << Opts->Value << "'" << std::endl;
 114
 115          if (system(Opts->Value.c_str()) != 0)
 116             _exit(100+Count);
 117       }
 118       _exit(0);
 119    }
 120
 121    // Wait for the child
 122    int Status = 0;
 123    while (waitpid(Child,&Status,0) != Child)
 124    {
 125       if (errno == EINTR)
 126          continue;
 127       return _error->Errno("waitpid","Couldn't wait for subprocess");
 128    }
 129
 130    // Restore sig int/quit
 131    signal(SIGQUIT,SIG_DFL);
 132    signal(SIGINT,SIG_DFL);
 133
 134    // Check for an error code.
 135    if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
 136    {
 137       unsigned int Count = WEXITSTATUS(Status);
 138       if (Count > 100)
 139       {
 140          Count -= 100;
 141          for (; Opts != 0 && Count != 1; Opts = Opts->Next, Count--);
 142          _error->Error("Problem executing scripts %s '%s'",Cnf,Opts->Value.c_str());
 143       }
 144
 145       return _error->Error("Sub-process returned an error code");
 146    }
 147
 148    return true;
 149 }
 150                                                                         /*}}}*/
 151
 152 // CopyFile - Buffered copy of a file                                   /*{{{*/
 153 // ---------------------------------------------------------------------
 154 /* The caller is expected to set things so that failure causes erasure */
 155 bool CopyFile(FileFd &From,FileFd &To)
 156 {
 157    if (From.IsOpen() == false || To.IsOpen() == false ||
 158          From.Failed() == true || To.Failed() == true)
 159       return false;
 160
 161    // Buffered copy between fds
 162    SPtrArray<unsigned char> Buf = new unsigned char[64000];
 163    unsigned long long Size = From.Size();
 164    while (Size != 0)
 165    {
 166       unsigned long long ToRead = Size;
 167       if (Size > 64000)
 168          ToRead = 64000;
 169
 170       if (From.Read(Buf,ToRead) == false ||
 171           To.Write(Buf,ToRead) == false)
 172          return false;
 173
 174       Size -= ToRead;
 175    }
 176
 177    return true;
 178 }
 179                                                                         /*}}}*/
 180 // GetLock - Gets a lock file                                           /*{{{*/
 181 // ---------------------------------------------------------------------
 182 /* This will create an empty file of the given name and lock it. Once this
 183    is done all other calls to GetLock in any other process will fail with
 184    -1. The return result is the fd of the file, the call should call
 185    close at some time. */
 186 int GetLock(string File,bool Errors)
 187 {
 188    // GetLock() is used in aptitude on directories with public-write access
 189    // Use O_NOFOLLOW here to prevent symlink traversal attacks
 190    int FD = open(File.c_str(),O_RDWR | O_CREAT | O_NOFOLLOW,0640);
 191    if (FD < 0)
 192    {
 193       // Read only .. can't have locking problems there.
 194       if (errno == EROFS)
 195       {
 196          _error->Warning(_("Not using locking for read only lock file %s"),File.c_str());
 197          return dup(0);       // Need something for the caller to close
 198       }
 199
 200       if (Errors == true)
 201          _error->Errno("open",_("Could not open lock file %s"),File.c_str());
 202
 203       // Feh.. We do this to distinguish the lock vs open case..
 204       errno = EPERM;
 205       return -1;
 206    }
 207    SetCloseExec(FD,true);
 208
 209    // Acquire a write lock
 210    struct flock fl;
 211    fl.l_type = F_WRLCK;
 212    fl.l_whence = SEEK_SET;
 213    fl.l_start = 0;
 214    fl.l_len = 0;
 215    if (fcntl(FD,F_SETLK,&fl) == -1)
 216    {
 217       // always close to not leak resources
 218       int Tmp = errno;
 219       close(FD);
 220       errno = Tmp;
 221
 222       if (errno == ENOLCK)
 223       {
 224          _error->Warning(_("Not using locking for nfs mounted lock file %s"),File.c_str());
 225          return dup(0);       // Need something for the caller to close
 226       }
 227
 228       if (Errors == true)
 229          _error->Errno("open",_("Could not get lock %s"),File.c_str());
 230
 231       return -1;
 232    }
 233
 234    return FD;
 235 }
 236                                                                         /*}}}*/
 237 // FileExists - Check if a file exists                                  /*{{{*/
 238 // ---------------------------------------------------------------------
 239 /* Beware: Directories are also files! */
 240 bool FileExists(string File)
 241 {
 242    struct stat Buf;
 243    if (stat(File.c_str(),&Buf) != 0)
 244       return false;
 245    return true;
 246 }
 247                                                                         /*}}}*/
 248 // RealFileExists - Check if a file exists and if it is really a file   /*{{{*/
 249 // ---------------------------------------------------------------------
 250 /* */
 251 bool RealFileExists(string File)
 252 {
 253    struct stat Buf;
 254    if (stat(File.c_str(),&Buf) != 0)
 255       return false;
 256    return ((Buf.st_mode & S_IFREG) != 0);
 257 }
 258                                                                         /*}}}*/
 259 // DirectoryExists - Check if a directory exists and is really one      /*{{{*/
 260 // ---------------------------------------------------------------------
 261 /* */
 262 bool DirectoryExists(string const &Path)
 263 {
 264    struct stat Buf;
 265    if (stat(Path.c_str(),&Buf) != 0)
 266       return false;
 267    return ((Buf.st_mode & S_IFDIR) != 0);
 268 }
 269                                                                         /*}}}*/
 270 // CreateDirectory - poor man's mkdir -p guarded by a parent directory  /*{{{*/
 271 // ---------------------------------------------------------------------
 272 /* This method will create all directories needed for path in good old
 273    mkdir -p style but refuses to do this if Parent is not a prefix of
 274    this Path. Example: /var/cache/ and /var/cache/apt/archives are given,
 275    so it will create apt/archives if /var/cache exists - on the other
 276    hand if the parent is /var/lib the creation will fail as this path
 277    is not a parent of the path to be generated. */
 278 bool CreateDirectory(string const &Parent, string const &Path)
 279 {
 280    if (Parent.empty() == true || Path.empty() == true)
 281       return false;
 282
 283    if (DirectoryExists(Path) == true)
 284       return true;
 285
 286    if (DirectoryExists(Parent) == false)
 287       return false;
 288
 289    // we are not going to create directories "into the blue"
 290    if (Path.compare(0, Parent.length(), Parent) != 0)
 291       return false;
 292
 293    vector<string> const dirs = VectorizeString(Path.substr(Parent.size()), '/');
 294    string progress = Parent;
 295    for (vector<string>::const_iterator d = dirs.begin(); d != dirs.end(); ++d)
 296    {
 297       if (d->empty() == true)
 298          continue;
 299
 300       progress.append("/").append(*d);
 301       if (DirectoryExists(progress) == true)
 302          continue;
 303
 304       if (mkdir(progress.c_str(), 0755) != 0)
 305          return false;
 306    }
 307    return true;
 308 }
 309                                                                         /*}}}*/
 310 // CreateAPTDirectoryIfNeeded - ensure that the given directory exists          /*{{{*/
 311 // ---------------------------------------------------------------------
 312 /* a small wrapper around CreateDirectory to check if it exists and to
 313    remove the trailing "/apt/" from the parent directory if needed */
 314 bool CreateAPTDirectoryIfNeeded(string const &Parent, string const &Path)
 315 {
 316    if (DirectoryExists(Path) == true)
 317       return true;
 318
 319    size_t const len = Parent.size();
 320    if (len > 5 && Parent.find("/apt/", len - 6, 5) == len - 5)
 321    {
 322       if (CreateDirectory(Parent.substr(0,len-5), Path) == true)
 323          return true;
 324    }
 325    else if (CreateDirectory(Parent, Path) == true)
 326       return true;
 327
 328    return false;
 329 }
 330                                                                         /*}}}*/
 331 // GetListOfFilesInDir - returns a vector of files in the given dir     /*{{{*/
 332 // ---------------------------------------------------------------------
 333 /* If an extension is given only files with this extension are included
 334    in the returned vector, otherwise every "normal" file is included. */
 335 std::vector<string> GetListOfFilesInDir(string const &Dir, string const &Ext,
 336                                         bool const &SortList, bool const &AllowNoExt)
 337 {
 338    std::vector<string> ext;
 339    ext.reserve(2);
 340    if (Ext.empty() == false)
 341       ext.push_back(Ext);
 342    if (AllowNoExt == true && ext.empty() == false)
 343       ext.push_back("");
 344    return GetListOfFilesInDir(Dir, ext, SortList);
 345 }
 346 std::vector<string> GetListOfFilesInDir(string const &Dir, std::vector<string> const &Ext,
 347                                         bool const &SortList)
 348 {
 349    // Attention debuggers: need to be set with the environment config file!
 350    bool const Debug = _config->FindB("Debug::GetListOfFilesInDir", false);
 351    if (Debug == true)
 352    {
 353       std::clog << "Accept in " << Dir << " only files with the following " << Ext.size() << " extensions:" << std::endl;
 354       if (Ext.empty() == true)
 355          std::clog << "\tNO extension" << std::endl;
 356       else
 357          for (std::vector<string>::const_iterator e = Ext.begin();
 358               e != Ext.end(); ++e)
 359             std::clog << '\t' << (e->empty() == true ? "NO" : *e) << " extension" << std::endl;
 360    }
 361
 362    std::vector<string> List;
 363
 364    if (DirectoryExists(Dir) == false)
 365    {
 366       _error->Error(_("List of files can't be created as '%s' is not a directory"), Dir.c_str());
 367       return List;
 368    }
 369
 370    Configuration::MatchAgainstConfig SilentIgnore("Dir::Ignore-Files-Silently");
 371    DIR *D = opendir(Dir.c_str());
 372    if (D == 0)
 373    {
 374       _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
 375       return List;
 376    }
 377
 378    for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D))
 379    {
 380       // skip "hidden" files
 381       if (Ent->d_name[0] == '.')
 382          continue;
 383
 384       // Make sure it is a file and not something else
 385       string const File = flCombine(Dir,Ent->d_name);
 386 #ifdef _DIRENT_HAVE_D_TYPE
 387       if (Ent->d_type != DT_REG)
 388 #endif
 389       {
 390          if (RealFileExists(File) == false)
 391          {
 392             // do not show ignoration warnings for directories
 393             if (
 394 #ifdef _DIRENT_HAVE_D_TYPE
 395                 Ent->d_type == DT_DIR ||
 396 #endif
 397                 DirectoryExists(File) == true)
 398                continue;
 399             if (SilentIgnore.Match(Ent->d_name) == false)
 400                _error->Notice(_("Ignoring '%s' in directory '%s' as it is not a regular file"), Ent->d_name, Dir.c_str());
 401             continue;
 402          }
 403       }
 404
 405       // check for accepted extension:
 406       // no extension given -> periods are bad as hell!
 407       // extensions given -> "" extension allows no extension
 408       if (Ext.empty() == false)
 409       {
 410          string d_ext = flExtension(Ent->d_name);
 411          if (d_ext == Ent->d_name) // no extension
 412          {
 413             if (std::find(Ext.begin(), Ext.end(), "") == Ext.end())
 414             {
 415                if (Debug == true)
 416                   std::clog << "Bad file: " << Ent->d_name << " → no extension" << std::endl;
 417                if (SilentIgnore.Match(Ent->d_name) == false)
 418                   _error->Notice(_("Ignoring file '%s' in directory '%s' as it has no filename extension"), Ent->d_name, Dir.c_str());
 419                continue;
 420             }
 421          }
 422          else if (std::find(Ext.begin(), Ext.end(), d_ext) == Ext.end())
 423          {
 424             if (Debug == true)
 425                std::clog << "Bad file: " << Ent->d_name << " → bad extension »" << flExtension(Ent->d_name) << "«" << std::endl;
 426             if (SilentIgnore.Match(Ent->d_name) == false)
 427                _error->Notice(_("Ignoring file '%s' in directory '%s' as it has an invalid filename extension"), Ent->d_name, Dir.c_str());
 428             continue;
 429          }
 430       }
 431
 432       // Skip bad filenames ala run-parts
 433       const char *C = Ent->d_name;
 434       for (; *C != 0; ++C)
 435          if (isalpha(*C) == 0 && isdigit(*C) == 0
 436              && *C != '_' && *C != '-' && *C != ':') {
 437             // no required extension -> dot is a bad character
 438             if (*C == '.' && Ext.empty() == false)
 439                continue;
 440             break;
 441          }
 442
 443       // we don't reach the end of the name -> bad character included
 444       if (*C != 0)
 445       {
 446          if (Debug == true)
 447             std::clog << "Bad file: " << Ent->d_name << " → bad character »"
 448                << *C << "« in filename (period allowed: " << (Ext.empty() ? "no" : "yes") << ")" << std::endl;
 449          continue;
 450       }
 451
 452       // skip filenames which end with a period. These are never valid
 453       if (*(C - 1) == '.')
 454       {
 455          if (Debug == true)
 456             std::clog << "Bad file: " << Ent->d_name << " → Period as last character" << std::endl;
 457          continue;
 458       }
 459
 460       if (Debug == true)
 461          std::clog << "Accept file: " << Ent->d_name << " in " << Dir << std::endl;
 462       List.push_back(File);
 463    }
 464    closedir(D);
 465
 466    if (SortList == true)
 467       std::sort(List.begin(),List.end());
 468    return List;
 469 }
 470 std::vector<string> GetListOfFilesInDir(string const &Dir, bool SortList)
 471 {
 472    bool const Debug = _config->FindB("Debug::GetListOfFilesInDir", false);
 473    if (Debug == true)
 474       std::clog << "Accept in " << Dir << " all regular files" << std::endl;
 475
 476    std::vector<string> List;
 477
 478    if (DirectoryExists(Dir) == false)
 479    {
 480       _error->Error(_("List of files can't be created as '%s' is not a directory"), Dir.c_str());
 481       return List;
 482    }
 483
 484    DIR *D = opendir(Dir.c_str());
 485    if (D == 0)
 486    {
 487       _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
 488       return List;
 489    }
 490
 491    for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D))
 492    {
 493       // skip "hidden" files
 494       if (Ent->d_name[0] == '.')
 495          continue;
 496
 497       // Make sure it is a file and not something else
 498       string const File = flCombine(Dir,Ent->d_name);
 499 #ifdef _DIRENT_HAVE_D_TYPE
 500       if (Ent->d_type != DT_REG)
 501 #endif
 502       {
 503          if (RealFileExists(File) == false)
 504          {
 505             if (Debug == true)
 506                std::clog << "Bad file: " << Ent->d_name << " → it is not a real file" << std::endl;
 507             continue;
 508          }
 509       }
 510
 511       // Skip bad filenames ala run-parts
 512       const char *C = Ent->d_name;
 513       for (; *C != 0; ++C)
 514          if (isalpha(*C) == 0 && isdigit(*C) == 0
 515              && *C != '_' && *C != '-' && *C != '.')
 516             break;
 517
 518       // we don't reach the end of the name -> bad character included
 519       if (*C != 0)
 520       {
 521          if (Debug == true)
 522             std::clog << "Bad file: " << Ent->d_name << " → bad character »" << *C << "« in filename" << std::endl;
 523          continue;
 524       }
 525
 526       // skip filenames which end with a period. These are never valid
 527       if (*(C - 1) == '.')
 528       {
 529          if (Debug == true)
 530             std::clog << "Bad file: " << Ent->d_name << " → Period as last character" << std::endl;
 531          continue;
 532       }
 533
 534       if (Debug == true)
 535          std::clog << "Accept file: " << Ent->d_name << " in " << Dir << std::endl;
 536       List.push_back(File);
 537    }
 538    closedir(D);
 539
 540    if (SortList == true)
 541       std::sort(List.begin(),List.end());
 542    return List;
 543 }
 544                                                                         /*}}}*/
 545 // SafeGetCWD - This is a safer getcwd that returns a dynamic string    /*{{{*/
 546 // ---------------------------------------------------------------------
 547 /* We return / on failure. */
 548 string SafeGetCWD()
 549 {
 550    // Stash the current dir.
 551    char S[300];
 552    S[0] = 0;
 553    if (getcwd(S,sizeof(S)-2) == 0)
 554       return "/";
 555    unsigned int Len = strlen(S);
 556    S[Len] = '/';
 557    S[Len+1] = 0;
 558    return S;
 559 }
 560                                                                         /*}}}*/
 561 // GetModificationTime - Get the mtime of the given file or -1 on error /*{{{*/
 562 // ---------------------------------------------------------------------
 563 /* We return / on failure. */
 564 time_t GetModificationTime(string const &Path)
 565 {
 566    struct stat St;
 567    if (stat(Path.c_str(), &St) < 0)
 568       return -1;
 569    return  St.st_mtime;
 570 }
 571                                                                         /*}}}*/
 572 // flNotDir - Strip the directory from the filename                     /*{{{*/
 573 // ---------------------------------------------------------------------
 574 /* */
 575 string flNotDir(string File)
 576 {
 577    string::size_type Res = File.rfind('/');
 578    if (Res == string::npos)
 579       return File;
 580    Res++;
 581    return string(File,Res,Res - File.length());
 582 }
 583                                                                         /*}}}*/
 584 // flNotFile - Strip the file from the directory name                   /*{{{*/
 585 // ---------------------------------------------------------------------
 586 /* Result ends in a / */
 587 string flNotFile(string File)
 588 {
 589    string::size_type Res = File.rfind('/');
 590    if (Res == string::npos)
 591       return "./";
 592    Res++;
 593    return string(File,0,Res);
 594 }
 595                                                                         /*}}}*/
 596 // flExtension - Return the extension for the file                      /*{{{*/
 597 // ---------------------------------------------------------------------
 598 /* */
 599 string flExtension(string File)
 600 {
 601    string::size_type Res = File.rfind('.');
 602    if (Res == string::npos)
 603       return File;
 604    Res++;
 605    return string(File,Res,Res - File.length());
 606 }
 607                                                                         /*}}}*/
 608 // flNoLink - If file is a symlink then deref it                        /*{{{*/
 609 // ---------------------------------------------------------------------
 610 /* If the name is not a link then the returned path is the input. */
 611 string flNoLink(string File)
 612 {
 613    struct stat St;
 614    if (lstat(File.c_str(),&St) != 0 || S_ISLNK(St.st_mode) == 0)
 615       return File;
 616    if (stat(File.c_str(),&St) != 0)
 617       return File;
 618
 619    /* Loop resolving the link. There is no need to limit the number of
 620       loops because the stat call above ensures that the symlink is not
 621       circular */
 622    char Buffer[1024];
 623    string NFile = File;
 624    while (1)
 625    {
 626       // Read the link
 627       ssize_t Res;
 628       if ((Res = readlink(NFile.c_str(),Buffer,sizeof(Buffer))) <= 0 ||
 629           (size_t)Res >= sizeof(Buffer))
 630           return File;
 631
 632       // Append or replace the previous path
 633       Buffer[Res] = 0;
 634       if (Buffer[0] == '/')
 635          NFile = Buffer;
 636       else
 637          NFile = flNotFile(NFile) + Buffer;
 638
 639       // See if we are done
 640       if (lstat(NFile.c_str(),&St) != 0)
 641          return File;
 642       if (S_ISLNK(St.st_mode) == 0)
 643          return NFile;
 644    }
 645 }
 646                                                                         /*}}}*/
 647 // flCombine - Combine a file and a directory                           /*{{{*/
 648 // ---------------------------------------------------------------------
 649 /* If the file is an absolute path then it is just returned, otherwise
 650    the directory is pre-pended to it. */
 651 string flCombine(string Dir,string File)
 652 {
 653    if (File.empty() == true)
 654       return string();
 655
 656    if (File[0] == '/' || Dir.empty() == true)
 657       return File;
 658    if (File.length() >= 2 && File[0] == '.' && File[1] == '/')
 659       return File;
 660    if (Dir[Dir.length()-1] == '/')
 661       return Dir + File;
 662    return Dir + '/' + File;
 663 }
 664                                                                         /*}}}*/
 665 // flAbsPath - Return the absolute path of the filename                 /*{{{*/
 666 // ---------------------------------------------------------------------
 667 /* */
 668 string flAbsPath(string File)
 669 {
 670    char *p = realpath(File.c_str(), NULL);
 671    if (p == NULL)
 672    {
 673       _error->Errno("realpath", "flAbsPath failed");
 674       return "";
 675    }
 676    std::string AbsPath(p);
 677    free(p);
 678    return AbsPath;
 679 }
 680                                                                         /*}}}*/
 681 // SetCloseExec - Set the close on exec flag                            /*{{{*/
 682 // ---------------------------------------------------------------------
 683 /* */
 684 void SetCloseExec(int Fd,bool Close)
 685 {
 686    if (fcntl(Fd,F_SETFD,(Close == false)?0:FD_CLOEXEC) != 0)
 687    {
 688       cerr << "FATAL -> Could not set close on exec " << strerror(errno) << endl;
 689       exit(100);
 690    }
 691 }
 692                                                                         /*}}}*/
 693 // SetNonBlock - Set the nonblocking flag                               /*{{{*/
 694 // ---------------------------------------------------------------------
 695 /* */
 696 void SetNonBlock(int Fd,bool Block)
 697 {
 698    int Flags = fcntl(Fd,F_GETFL) & (~O_NONBLOCK);
 699    if (fcntl(Fd,F_SETFL,Flags | ((Block == false)?0:O_NONBLOCK)) != 0)
 700    {
 701       cerr << "FATAL -> Could not set non-blocking flag " << strerror(errno) << endl;
 702       exit(100);
 703    }
 704 }
 705                                                                         /*}}}*/
 706 // WaitFd - Wait for a FD to become readable                            /*{{{*/
 707 // ---------------------------------------------------------------------
 708 /* This waits for a FD to become readable using select. It is useful for
 709    applications making use of non-blocking sockets. The timeout is
 710    in seconds. */
 711 bool WaitFd(int Fd,bool write,unsigned long timeout)
 712 {
 713    fd_set Set;
 714    struct timeval tv;
 715    FD_ZERO(&Set);
 716    FD_SET(Fd,&Set);
 717    tv.tv_sec = timeout;
 718    tv.tv_usec = 0;
 719    if (write == true)
 720    {
 721       int Res;
 722       do
 723       {
 724          Res = select(Fd+1,0,&Set,0,(timeout != 0?&tv:0));
 725       }
 726       while (Res < 0 && errno == EINTR);
 727
 728       if (Res <= 0)
 729          return false;
 730    }
 731    else
 732    {
 733       int Res;
 734       do
 735       {
 736          Res = select(Fd+1,&Set,0,0,(timeout != 0?&tv:0));
 737       }
 738       while (Res < 0 && errno == EINTR);
 739
 740       if (Res <= 0)
 741          return false;
 742    }
 743
 744    return true;
 745 }
 746                                                                         /*}}}*/
 747 // MergeKeepFdsFromConfiguration - Merge APT::Keep-Fds configuration    /*{{{*/
 748 // ---------------------------------------------------------------------
 749 /* This is used to merge the APT::Keep-Fds with the provided KeepFDs
 750  * set.
 751  */
 752 void MergeKeepFdsFromConfiguration(std::set<int> &KeepFDs)
 753 {
 754       Configuration::Item const *Opts = _config->Tree("APT::Keep-Fds");
 755       if (Opts != 0 && Opts->Child != 0)
 756       {
 757          Opts = Opts->Child;
 758          for (; Opts != 0; Opts = Opts->Next)
 759          {
 760             if (Opts->Value.empty() == true)
 761                continue;
 762             int fd = atoi(Opts->Value.c_str());
 763             KeepFDs.insert(fd);
 764          }
 765       }
 766 }
 767                                                                         /*}}}*/
 768 // ExecFork - Magical fork that sanitizes the context before execing    /*{{{*/
 769 // ---------------------------------------------------------------------
 770 /* This is used if you want to cleanse the environment for the forked
 771    child, it fixes up the important signals and nukes all of the fds,
 772    otherwise acts like normal fork. */
 773 pid_t ExecFork()
 774 {
 775       set<int> KeepFDs;
 776       // we need to merge the Keep-Fds as external tools like
 777       // debconf-apt-progress use it
 778       MergeKeepFdsFromConfiguration(KeepFDs);
 779       return ExecFork(KeepFDs);
 780 }
 781
 782 pid_t ExecFork(std::set<int> KeepFDs)
 783 {
 784    // Fork off the process
 785    pid_t Process = fork();
 786    if (Process < 0)
 787    {
 788       cerr << "FATAL -> Failed to fork." << endl;
 789       exit(100);
 790    }
 791
 792    // Spawn the subprocess
 793    if (Process == 0)
 794    {
 795       // Setup the signals
 796       signal(SIGPIPE,SIG_DFL);
 797       signal(SIGQUIT,SIG_DFL);
 798       signal(SIGINT,SIG_DFL);
 799       signal(SIGWINCH,SIG_DFL);
 800       signal(SIGCONT,SIG_DFL);
 801       signal(SIGTSTP,SIG_DFL);
 802
 803       // Close all of our FDs - just in case
 804       for (int K = 3; K != sysconf(_SC_OPEN_MAX); K++)
 805       {
 806          if(KeepFDs.find(K) == KeepFDs.end())
 807             fcntl(K,F_SETFD,FD_CLOEXEC);
 808       }
 809    }
 810
 811    return Process;
 812 }
 813                                                                         /*}}}*/
 814 // ExecWait - Fancy waitpid                                             /*{{{*/
 815 // ---------------------------------------------------------------------
 816 /* Waits for the given sub process. If Reap is set then no errors are
 817    generated. Otherwise a failed subprocess will generate a proper descriptive
 818    message */
 819 bool ExecWait(pid_t Pid,const char *Name,bool Reap)
 820 {
 821    if (Pid <= 1)
 822       return true;
 823
 824    // Wait and collect the error code
 825    int Status;
 826    while (waitpid(Pid,&Status,0) != Pid)
 827    {
 828       if (errno == EINTR)
 829          continue;
 830
 831       if (Reap == true)
 832          return false;
 833
 834       return _error->Error(_("Waited for %s but it wasn't there"),Name);
 835    }
 836
 837
 838    // Check for an error code.
 839    if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
 840    {
 841       if (Reap == true)
 842          return false;
 843       if (WIFSIGNALED(Status) != 0)
 844       {
 845          if( WTERMSIG(Status) == SIGSEGV)
 846             return _error->Error(_("Sub-process %s received a segmentation fault."),Name);
 847          else
 848             return _error->Error(_("Sub-process %s received signal %u."),Name, WTERMSIG(Status));
 849       }
 850
 851       if (WIFEXITED(Status) != 0)
 852          return _error->Error(_("Sub-process %s returned an error code (%u)"),Name,WEXITSTATUS(Status));
 853
 854       return _error->Error(_("Sub-process %s exited unexpectedly"),Name);
 855    }
 856
 857    return true;
 858 }
 859                                                                         /*}}}*/
 860 // StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned     /*{{{*/
 861 bool StartsWithGPGClearTextSignature(string const &FileName)
 862 {
 863    static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----\n";
 864    char buffer[strlen(SIGMSG)+1];
 865    FILE* gpg = fopen(FileName.c_str(), "r");
 866    if (gpg == NULL)
 867       return false;
 868
 869    char const * const test = fgets(buffer, sizeof(buffer), gpg);
 870    fclose(gpg);
 871    if (test == NULL || strcmp(buffer, SIGMSG) != 0)
 872       return false;
 873
 874    return true;
 875 }
 876                                                                         /*}}}*/
 877
 878 class FileFdPrivate {                                                   /*{{{*/
 879         public:
 880 #ifdef HAVE_ZLIB
 881         gzFile gz;
 882 #endif
 883 #ifdef HAVE_BZ2
 884         BZFILE* bz2;
 885 #endif
 886 #ifdef HAVE_LZMA
 887         struct LZMAFILE {
 888            FILE* file;
 889            uint8_t buffer[4096];
 890            lzma_stream stream;
 891            lzma_ret err;
 892            bool eof;
 893            bool compressing;
 894
 895            LZMAFILE() : file(NULL), eof(false), compressing(false) { buffer[0] = '\0'; }
 896            ~LZMAFILE() {
 897               if (compressing == true)
 898               {
 899                 for (;;) {
 900                         stream.avail_out = sizeof(buffer)/sizeof(buffer[0]);
 901                         stream.next_out = buffer;
 902                         err = lzma_code(&stream, LZMA_FINISH);
 903                         if (err != LZMA_OK && err != LZMA_STREAM_END)
 904                         {
 905                                 _error->Error("~LZMAFILE: Compress finalisation failed");
 906                                 break;
 907                         }
 908                         size_t const n =  sizeof(buffer)/sizeof(buffer[0]) - stream.avail_out;
 909                         if (n && fwrite(buffer, 1, n, file) != n)
 910                         {
 911                                 _error->Errno("~LZMAFILE",_("Write error"));
 912                                 break;
 913                         }
 914                         if (err == LZMA_STREAM_END)
 915                                 break;
 916                 }
 917               }
 918               lzma_end(&stream);
 919               fclose(file);
 920            }
 921         };
 922         LZMAFILE* lzma;
 923 #endif
 924         int compressed_fd;
 925         pid_t compressor_pid;
 926         bool pipe;
 927         APT::Configuration::Compressor compressor;
 928         unsigned int openmode;
 929         unsigned long long seekpos;
 930         FileFdPrivate() :
 931 #ifdef HAVE_ZLIB
 932                           gz(NULL),
 933 #endif
 934 #ifdef HAVE_BZ2
 935                           bz2(NULL),
 936 #endif
 937 #ifdef HAVE_LZMA
 938                           lzma(NULL),
 939 #endif
 940                           compressed_fd(-1), compressor_pid(-1), pipe(false),
 941                           openmode(0), seekpos(0) {};
 942         bool InternalClose(std::string const &FileName)
 943         {
 944            if (false)
 945               /* dummy so that the rest can be 'else if's */;
 946 #ifdef HAVE_ZLIB
 947            else if (gz != NULL) {
 948               int const e = gzclose(gz);
 949               gz = NULL;
 950               // gzdclose() on empty files always fails with "buffer error" here, ignore that
 951               if (e != 0 && e != Z_BUF_ERROR)
 952                  return _error->Errno("close",_("Problem closing the gzip file %s"), FileName.c_str());
 953            }
 954 #endif
 955 #ifdef HAVE_BZ2
 956            else if (bz2 != NULL) {
 957               BZ2_bzclose(bz2);
 958               bz2 = NULL;
 959            }
 960 #endif
 961 #ifdef HAVE_LZMA
 962            else if (lzma != NULL) {
 963               delete lzma;
 964               lzma = NULL;
 965            }
 966 #endif
 967            return true;
 968         }
 969         bool CloseDown(std::string const &FileName)
 970         {
 971            bool const Res = InternalClose(FileName);
 972
 973            if (compressor_pid > 0)
 974               ExecWait(compressor_pid, "FileFdCompressor", true);
 975            compressor_pid = -1;
 976
 977            return Res;
 978         }
 979         bool InternalStream() const {
 980            return false
 981 #ifdef HAVE_BZ2
 982               || bz2 != NULL
 983 #endif
 984 #ifdef HAVE_LZMA
 985               || lzma != NULL
 986 #endif
 987               ;
 988         }
 989
 990
 991         ~FileFdPrivate() { CloseDown(""); }
 992 };
 993                                                                         /*}}}*/
 994 // FileFd::Open - Open a file                                           /*{{{*/
 995 // ---------------------------------------------------------------------
 996 /* The most commonly used open mode combinations are given with Mode */
 997 bool FileFd::Open(string FileName,unsigned int const Mode,CompressMode Compress, unsigned long const AccessMode)
 998 {
 999    if (Mode == ReadOnlyGzip)
1000       return Open(FileName, ReadOnly, Gzip, AccessMode);
1001
1002    if (Compress == Auto && (Mode & WriteOnly) == WriteOnly)
1003       return FileFdError("Autodetection on %s only works in ReadOnly openmode!", FileName.c_str());
1004
1005    std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors();
1006    std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin();
1007    if (Compress == Auto)
1008    {
1009       for (; compressor != compressors.end(); ++compressor)
1010       {
1011          std::string file = FileName + compressor->Extension;
1012          if (FileExists(file) == false)
1013             continue;
1014          FileName = file;
1015          break;
1016       }
1017    }
1018    else if (Compress == Extension)
1019    {
1020       std::string::size_type const found = FileName.find_last_of('.');
1021       std::string ext;
1022       if (found != std::string::npos)
1023       {
1024          ext = FileName.substr(found);
1025          if (ext == ".new" || ext == ".bak")
1026          {
1027             std::string::size_type const found2 = FileName.find_last_of('.', found - 1);
1028             if (found2 != std::string::npos)
1029                ext = FileName.substr(found2, found - found2);
1030             else
1031                ext.clear();
1032          }
1033       }
1034       for (; compressor != compressors.end(); ++compressor)
1035          if (ext == compressor->Extension)
1036             break;
1037       // no matching extension - assume uncompressed (imagine files like 'example.org_Packages')
1038       if (compressor == compressors.end())
1039          for (compressor = compressors.begin(); compressor != compressors.end(); ++compressor)
1040             if (compressor->Name == ".")
1041                break;
1042    }
1043    else
1044    {
1045       std::string name;
1046       switch (Compress)
1047       {
1048       case None: name = "."; break;
1049       case Gzip: name = "gzip"; break;
1050       case Bzip2: name = "bzip2"; break;
1051       case Lzma: name = "lzma"; break;
1052       case Xz: name = "xz"; break;
1053       case Auto:
1054       case Extension:
1055          // Unreachable
1056          return FileFdError("Opening File %s in None, Auto or Extension should be already handled?!?", FileName.c_str());
1057       }
1058       for (; compressor != compressors.end(); ++compressor)
1059          if (compressor->Name == name)
1060             break;
1061       if (compressor == compressors.end())
1062          return FileFdError("Can't find a configured compressor %s for file %s", name.c_str(), FileName.c_str());
1063    }
1064
1065    if (compressor == compressors.end())
1066       return FileFdError("Can't find a match for specified compressor mode for file %s", FileName.c_str());
1067    return Open(FileName, Mode, *compressor, AccessMode);
1068 }
1069 bool FileFd::Open(string FileName,unsigned int const Mode,APT::Configuration::Compressor const &compressor, unsigned long const AccessMode)
1070 {
1071    Close();
1072    Flags = AutoClose;
1073
1074    if ((Mode & WriteOnly) != WriteOnly && (Mode & (Atomic | Create | Empty | Exclusive)) != 0)
1075       return FileFdError("ReadOnly mode for %s doesn't accept additional flags!", FileName.c_str());
1076    if ((Mode & ReadWrite) == 0)
1077       return FileFdError("No openmode provided in FileFd::Open for %s", FileName.c_str());
1078
1079    if ((Mode & Atomic) == Atomic)
1080    {
1081       Flags |= Replace;
1082    }
1083    else if ((Mode & (Exclusive | Create)) == (Exclusive | Create))
1084    {
1085       // for atomic, this will be done by rename in Close()
1086       unlink(FileName.c_str());
1087    }
1088    if ((Mode & Empty) == Empty)
1089    {
1090       struct stat Buf;
1091       if (lstat(FileName.c_str(),&Buf) == 0 && S_ISLNK(Buf.st_mode))
1092          unlink(FileName.c_str());
1093    }
1094
1095    int fileflags = 0;
1096    #define if_FLAGGED_SET(FLAG, MODE) if ((Mode & FLAG) == FLAG) fileflags |= MODE
1097    if_FLAGGED_SET(ReadWrite, O_RDWR);
1098    else if_FLAGGED_SET(ReadOnly, O_RDONLY);
1099    else if_FLAGGED_SET(WriteOnly, O_WRONLY);
1100
1101    if_FLAGGED_SET(Create, O_CREAT);
1102    if_FLAGGED_SET(Empty, O_TRUNC);
1103    if_FLAGGED_SET(Exclusive, O_EXCL);
1104    #undef if_FLAGGED_SET
1105
1106    if ((Mode & Atomic) == Atomic)
1107    {
1108       char *name = strdup((FileName + ".XXXXXX").c_str());
1109
1110       if((iFd = mkstemp(name)) == -1)
1111       {
1112           free(name);
1113           return FileFdErrno("mkstemp", "Could not create temporary file for %s", FileName.c_str());
1114       }
1115
1116       TemporaryFileName = string(name);
1117       free(name);
1118
1119       // umask() will always set the umask and return the previous value, so
1120       // we first set the umask and then reset it to the old value
1121       mode_t const CurrentUmask = umask(0);
1122       umask(CurrentUmask);
1123       // calculate the actual file permissions (just like open/creat)
1124       mode_t const FilePermissions = (AccessMode & ~CurrentUmask);
1125
1126       if(fchmod(iFd, FilePermissions) == -1)
1127           return FileFdErrno("fchmod", "Could not change permissions for temporary file %s", TemporaryFileName.c_str());
1128    }
1129    else
1130       iFd = open(FileName.c_str(), fileflags, AccessMode);
1131
1132    this->FileName = FileName;
1133    if (iFd == -1 || OpenInternDescriptor(Mode, compressor) == false)
1134    {
1135       if (iFd != -1)
1136       {
1137          close (iFd);
1138          iFd = -1;
1139       }
1140       return FileFdErrno("open",_("Could not open file %s"), FileName.c_str());
1141    }
1142
1143    SetCloseExec(iFd,true);
1144    return true;
1145 }
1146                                                                         /*}}}*/
1147 // FileFd::OpenDescriptor - Open a filedescriptor                       /*{{{*/
1148 // ---------------------------------------------------------------------
1149 /* */
1150 bool FileFd::OpenDescriptor(int Fd, unsigned int const Mode, CompressMode Compress, bool AutoClose)
1151 {
1152    std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors();
1153    std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin();
1154    std::string name;
1155
1156    // compat with the old API
1157    if (Mode == ReadOnlyGzip && Compress == None)
1158       Compress = Gzip;
1159
1160    switch (Compress)
1161    {
1162    case None: name = "."; break;
1163    case Gzip: name = "gzip"; break;
1164    case Bzip2: name = "bzip2"; break;
1165    case Lzma: name = "lzma"; break;
1166    case Xz: name = "xz"; break;
1167    case Auto:
1168    case Extension:
1169       if (AutoClose == true && Fd != -1)
1170          close(Fd);
1171       return FileFdError("Opening Fd %d in Auto or Extension compression mode is not supported", Fd);
1172    }
1173    for (; compressor != compressors.end(); ++compressor)
1174       if (compressor->Name == name)
1175          break;
1176    if (compressor == compressors.end())
1177    {
1178       if (AutoClose == true && Fd != -1)
1179          close(Fd);
1180       return FileFdError("Can't find a configured compressor %s for file %s", name.c_str(), FileName.c_str());
1181    }
1182    return OpenDescriptor(Fd, Mode, *compressor, AutoClose);
1183 }
1184 bool FileFd::OpenDescriptor(int Fd, unsigned int const Mode, APT::Configuration::Compressor const &compressor, bool AutoClose)
1185 {
1186    Close();
1187    Flags = (AutoClose) ? FileFd::AutoClose : 0;
1188    iFd = Fd;
1189    this->FileName = "";
1190    if (OpenInternDescriptor(Mode, compressor) == false)
1191    {
1192       if (iFd != -1 && (
1193         (Flags & Compressed) == Compressed ||
1194         AutoClose == true))
1195       {
1196          close (iFd);
1197          iFd = -1;
1198       }
1199       return FileFdError(_("Could not open file descriptor %d"), Fd);
1200    }
1201    return true;
1202 }
1203 bool FileFd::OpenInternDescriptor(unsigned int const Mode, APT::Configuration::Compressor const &compressor)
1204 {
1205    if (iFd == -1)
1206       return false;
1207    if (compressor.Name == "." || compressor.Binary.empty() == true)
1208       return true;
1209
1210 #if defined HAVE_ZLIB || defined HAVE_BZ2 || defined HAVE_LZMA
1211    // the API to open files is similar, so setup to avoid code duplicates later
1212    // and while at it ensure that we close before opening (if its a reopen)
1213    void* (*compress_open)(int, const char *) = NULL;
1214    if (false)
1215       /* dummy so that the rest can be 'else if's */;
1216 #define APT_COMPRESS_INIT(NAME,OPEN) \
1217    else if (compressor.Name == NAME) \
1218    { \
1219       compress_open = (void*(*)(int, const char *)) OPEN; \
1220       if (d != NULL) d->InternalClose(FileName); \
1221    }
1222 #ifdef HAVE_ZLIB
1223    APT_COMPRESS_INIT("gzip", gzdopen)
1224 #endif
1225 #ifdef HAVE_BZ2
1226    APT_COMPRESS_INIT("bzip2", BZ2_bzdopen)
1227 #endif
1228 #ifdef HAVE_LZMA
1229    APT_COMPRESS_INIT("xz", fdopen)
1230    APT_COMPRESS_INIT("lzma", fdopen)
1231 #endif
1232 #undef APT_COMPRESS_INIT
1233 #endif
1234
1235    if (d == NULL)
1236    {
1237       d = new FileFdPrivate();
1238       d->openmode = Mode;
1239       d->compressor = compressor;
1240 #if defined HAVE_ZLIB || defined HAVE_BZ2 || defined HAVE_LZMA
1241       if ((Flags & AutoClose) != AutoClose && compress_open != NULL)
1242       {
1243          // Need to duplicate fd here or gz/bz2 close for cleanup will close the fd as well
1244          int const internFd = dup(iFd);
1245          if (internFd == -1)
1246             return FileFdErrno("OpenInternDescriptor", _("Could not open file descriptor %d"), iFd);
1247          iFd = internFd;
1248       }
1249 #endif
1250    }
1251
1252 #if defined HAVE_ZLIB || defined HAVE_BZ2 || defined HAVE_LZMA
1253    if (compress_open != NULL)
1254    {
1255       void* compress_struct = NULL;
1256       if ((Mode & ReadWrite) == ReadWrite)
1257          compress_struct = compress_open(iFd, "r+");
1258       else if ((Mode & WriteOnly) == WriteOnly)
1259          compress_struct = compress_open(iFd, "w");
1260       else
1261          compress_struct = compress_open(iFd, "r");
1262       if (compress_struct == NULL)
1263          return false;
1264
1265       if (false)
1266          /* dummy so that the rest can be 'else if's */;
1267 #ifdef HAVE_ZLIB
1268       else if (compressor.Name == "gzip")
1269          d->gz = (gzFile) compress_struct;
1270 #endif
1271 #ifdef HAVE_BZ2
1272       else if (compressor.Name == "bzip2")
1273          d->bz2 = (BZFILE*) compress_struct;
1274 #endif
1275 #ifdef HAVE_LZMA
1276       else if (compressor.Name == "xz" || compressor.Name == "lzma")
1277       {
1278          uint32_t const xzlevel = 6;
1279          uint64_t const memlimit = UINT64_MAX;
1280          if (d->lzma == NULL)
1281             d->lzma = new FileFdPrivate::LZMAFILE;
1282          d->lzma->file = (FILE*) compress_struct;
1283          lzma_stream tmp_stream = LZMA_STREAM_INIT;
1284          d->lzma->stream = tmp_stream;
1285
1286          if ((Mode & ReadWrite) == ReadWrite)
1287             return FileFdError("ReadWrite mode is not supported for file %s", FileName.c_str());
1288
1289          if ((Mode & WriteOnly) == WriteOnly)
1290          {
1291             if (compressor.Name == "xz")
1292             {
1293                if (lzma_easy_encoder(&d->lzma->stream, xzlevel, LZMA_CHECK_CRC32) != LZMA_OK)
1294                   return false;
1295             }
1296             else
1297             {
1298                lzma_options_lzma options;
1299                lzma_lzma_preset(&options, xzlevel);
1300                if (lzma_alone_encoder(&d->lzma->stream, &options) != LZMA_OK)
1301                   return false;
1302             }
1303             d->lzma->compressing = true;
1304          }
1305          else
1306          {
1307             if (compressor.Name == "xz")
1308             {
1309                if (lzma_auto_decoder(&d->lzma->stream, memlimit, 0) != LZMA_OK)
1310                   return false;
1311             }
1312             else
1313             {
1314                if (lzma_alone_decoder(&d->lzma->stream, memlimit) != LZMA_OK)
1315                   return false;
1316             }
1317             d->lzma->compressing = false;
1318          }
1319       }
1320 #endif
1321       Flags |= Compressed;
1322       return true;
1323    }
1324 #endif
1325
1326    // collect zombies here in case we reopen
1327    if (d->compressor_pid > 0)
1328       ExecWait(d->compressor_pid, "FileFdCompressor", true);
1329
1330    if ((Mode & ReadWrite) == ReadWrite)
1331       return FileFdError("ReadWrite mode is not supported for file %s", FileName.c_str());
1332
1333    bool const Comp = (Mode & WriteOnly) == WriteOnly;
1334    if (Comp == false)
1335    {
1336       // Handle 'decompression' of empty files
1337       struct stat Buf;
1338       fstat(iFd, &Buf);
1339       if (Buf.st_size == 0 && S_ISFIFO(Buf.st_mode) == false)
1340          return true;
1341
1342       // We don't need the file open - instead let the compressor open it
1343       // as he properly knows better how to efficiently read from 'his' file
1344       if (FileName.empty() == false)
1345       {
1346          close(iFd);
1347          iFd = -1;
1348       }
1349    }
1350
1351    // Create a data pipe
1352    int Pipe[2] = {-1,-1};
1353    if (pipe(Pipe) != 0)
1354       return FileFdErrno("pipe",_("Failed to create subprocess IPC"));
1355    for (int J = 0; J != 2; J++)
1356       SetCloseExec(Pipe[J],true);
1357
1358    d->compressed_fd = iFd;
1359    d->pipe = true;
1360
1361    if (Comp == true)
1362       iFd = Pipe[1];
1363    else
1364       iFd = Pipe[0];
1365
1366    // The child..
1367    d->compressor_pid = ExecFork();
1368    if (d->compressor_pid == 0)
1369    {
1370       if (Comp == true)
1371       {
1372          dup2(d->compressed_fd,STDOUT_FILENO);
1373          dup2(Pipe[0],STDIN_FILENO);
1374       }
1375       else
1376       {
1377          if (d->compressed_fd != -1)
1378             dup2(d->compressed_fd,STDIN_FILENO);
1379          dup2(Pipe[1],STDOUT_FILENO);
1380       }
1381       int const nullfd = open("/dev/null", O_WRONLY);
1382       if (nullfd != -1)
1383       {
1384          dup2(nullfd,STDERR_FILENO);
1385          close(nullfd);
1386       }
1387
1388       SetCloseExec(STDOUT_FILENO,false);
1389       SetCloseExec(STDIN_FILENO,false);
1390
1391       std::vector<char const*> Args;
1392       Args.push_back(compressor.Binary.c_str());
1393       std::vector<std::string> const * const addArgs =
1394                 (Comp == true) ? &(compressor.CompressArgs) : &(compressor.UncompressArgs);
1395       for (std::vector<std::string>::const_iterator a = addArgs->begin();
1396            a != addArgs->end(); ++a)
1397          Args.push_back(a->c_str());
1398       if (Comp == false && FileName.empty() == false)
1399       {
1400          // commands not needing arguments, do not need to be told about using standard output
1401          // in reality, only testcases with tools like cat, rev, rot13, … are able to trigger this
1402          if (compressor.CompressArgs.empty() == false && compressor.UncompressArgs.empty() == false)
1403             Args.push_back("--stdout");
1404          if (TemporaryFileName.empty() == false)
1405             Args.push_back(TemporaryFileName.c_str());
1406          else
1407             Args.push_back(FileName.c_str());
1408       }
1409       Args.push_back(NULL);
1410
1411       execvp(Args[0],(char **)&Args[0]);
1412       cerr << _("Failed to exec compressor ") << Args[0] << endl;
1413       _exit(100);
1414    }
1415    if (Comp == true)
1416       close(Pipe[0]);
1417    else
1418       close(Pipe[1]);
1419
1420    return true;
1421 }
1422                                                                         /*}}}*/
1423 // FileFd::~File - Closes the file                                      /*{{{*/
1424 // ---------------------------------------------------------------------
1425 /* If the proper modes are selected then we close the Fd and possibly
1426    unlink the file on error. */
1427 FileFd::~FileFd()
1428 {
1429    Close();
1430    if (d != NULL)
1431       d->CloseDown(FileName);
1432    delete d;
1433    d = NULL;
1434 }
1435                                                                         /*}}}*/
1436 // FileFd::Read - Read a bit of the file                                /*{{{*/
1437 // ---------------------------------------------------------------------
1438 /* We are careful to handle interruption by a signal while reading
1439    gracefully. */
1440 bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual)
1441 {
1442    ssize_t Res;
1443    errno = 0;
1444    if (Actual != 0)
1445       *Actual = 0;
1446    *((char *)To) = '\0';
1447    do
1448    {
1449       if (false)
1450          /* dummy so that the rest can be 'else if's */;
1451 #ifdef HAVE_ZLIB
1452       else if (d != NULL && d->gz != NULL)
1453          Res = gzread(d->gz,To,Size);
1454 #endif
1455 #ifdef HAVE_BZ2
1456       else if (d != NULL && d->bz2 != NULL)
1457          Res = BZ2_bzread(d->bz2,To,Size);
1458 #endif
1459 #ifdef HAVE_LZMA
1460       else if (d != NULL && d->lzma != NULL)
1461       {
1462          if (d->lzma->eof == true)
1463             break;
1464
1465          d->lzma->stream.next_out = (uint8_t *) To;
1466          d->lzma->stream.avail_out = Size;
1467          if (d->lzma->stream.avail_in == 0)
1468          {
1469             d->lzma->stream.next_in = d->lzma->buffer;
1470             d->lzma->stream.avail_in = fread(d->lzma->buffer, 1, sizeof(d->lzma->buffer)/sizeof(d->lzma->buffer[0]), d->lzma->file);
1471          }
1472          d->lzma->err = lzma_code(&d->lzma->stream, LZMA_RUN);
1473          if (d->lzma->err == LZMA_STREAM_END)
1474          {
1475             d->lzma->eof = true;
1476             Res = Size - d->lzma->stream.avail_out;
1477          }
1478          else if (d->lzma->err != LZMA_OK)
1479          {
1480             Res = -1;
1481             errno = 0;
1482          }
1483          else
1484          {
1485             Res = Size - d->lzma->stream.avail_out;
1486             if (Res == 0)
1487             {
1488                // lzma run was okay, but produced no output…
1489                Res = -1;
1490                errno = EINTR;
1491             }
1492          }
1493       }
1494 #endif
1495       else
1496          Res = read(iFd,To,Size);
1497
1498       if (Res < 0)
1499       {
1500          if (errno == EINTR)
1501          {
1502             // trick the while-loop into running again
1503             Res = 1;
1504             errno = 0;
1505             continue;
1506          }
1507          if (false)
1508             /* dummy so that the rest can be 'else if's */;
1509 #ifdef HAVE_ZLIB
1510          else if (d != NULL && d->gz != NULL)
1511          {
1512             int err;
1513             char const * const errmsg = gzerror(d->gz, &err);
1514             if (err != Z_ERRNO)
1515                return FileFdError("gzread: %s (%d: %s)", _("Read error"), err, errmsg);
1516          }
1517 #endif
1518 #ifdef HAVE_BZ2
1519          else if (d != NULL && d->bz2 != NULL)
1520          {
1521             int err;
1522             char const * const errmsg = BZ2_bzerror(d->bz2, &err);
1523             if (err != BZ_IO_ERROR)
1524                return FileFdError("BZ2_bzread: %s %s (%d: %s)", FileName.c_str(), _("Read error"), err, errmsg);
1525          }
1526 #endif
1527 #ifdef HAVE_LZMA
1528          else if (d != NULL && d->lzma != NULL)
1529             return FileFdError("lzma_read: %s (%d)", _("Read error"), d->lzma->err);
1530 #endif
1531          return FileFdErrno("read",_("Read error"));
1532       }
1533
1534       To = (char *)To + Res;
1535       Size -= Res;
1536       if (d != NULL)
1537          d->seekpos += Res;
1538       if (Actual != 0)
1539          *Actual += Res;
1540    }
1541    while (Res > 0 && Size > 0);
1542
1543    if (Size == 0)
1544       return true;
1545
1546    // Eof handling
1547    if (Actual != 0)
1548    {
1549       Flags |= HitEof;
1550       return true;
1551    }
1552
1553    return FileFdError(_("read, still have %llu to read but none left"), Size);
1554 }
1555                                                                         /*}}}*/
1556 // FileFd::ReadLine - Read a complete line from the file                /*{{{*/
1557 // ---------------------------------------------------------------------
1558 /* Beware: This method can be quiet slow for big buffers on UNcompressed
1559    files because of the naive implementation! */
1560 char* FileFd::ReadLine(char *To, unsigned long long const Size)
1561 {
1562    *To = '\0';
1563 #ifdef HAVE_ZLIB
1564    if (d != NULL && d->gz != NULL)
1565       return gzgets(d->gz, To, Size);
1566 #endif
1567
1568    unsigned long long read = 0;
1569    while ((Size - 1) != read)
1570    {
1571       unsigned long long done = 0;
1572       if (Read(To + read, 1, &done) == false)
1573          return NULL;
1574       if (done == 0)
1575          break;
1576       if (To[read++] == '\n')
1577          break;
1578    }
1579    if (read == 0)
1580       return NULL;
1581    To[read] = '\0';
1582    return To;
1583 }
1584                                                                         /*}}}*/
1585 // FileFd::Write - Write to the file                                    /*{{{*/
1586 // ---------------------------------------------------------------------
1587 /* */
1588 bool FileFd::Write(const void *From,unsigned long long Size)
1589 {
1590    ssize_t Res;
1591    errno = 0;
1592    do
1593    {
1594       if (false)
1595          /* dummy so that the rest can be 'else if's */;
1596 #ifdef HAVE_ZLIB
1597       else if (d != NULL && d->gz != NULL)
1598          Res = gzwrite(d->gz,From,Size);
1599 #endif
1600 #ifdef HAVE_BZ2
1601       else if (d != NULL && d->bz2 != NULL)
1602          Res = BZ2_bzwrite(d->bz2,(void*)From,Size);
1603 #endif
1604 #ifdef HAVE_LZMA
1605       else if (d != NULL && d->lzma != NULL)
1606       {
1607          d->lzma->stream.next_in = (uint8_t *)From;
1608          d->lzma->stream.avail_in = Size;
1609          d->lzma->stream.next_out = d->lzma->buffer;
1610          d->lzma->stream.avail_out = sizeof(d->lzma->buffer)/sizeof(d->lzma->buffer[0]);
1611          d->lzma->err = lzma_code(&d->lzma->stream, LZMA_RUN);
1612          if (d->lzma->err != LZMA_OK)
1613             return false;
1614          size_t const n = sizeof(d->lzma->buffer)/sizeof(d->lzma->buffer[0]) - d->lzma->stream.avail_out;
1615          size_t const m = (n == 0) ? 0 : fwrite(d->lzma->buffer, 1, n, d->lzma->file);
1616          if (m != n)
1617             Res = -1;
1618          else
1619             Res = Size - d->lzma->stream.avail_in;
1620       }
1621 #endif
1622       else
1623          Res = write(iFd,From,Size);
1624
1625       if (Res < 0 && errno == EINTR)
1626          continue;
1627       if (Res < 0)
1628       {
1629          if (false)
1630             /* dummy so that the rest can be 'else if's */;
1631 #ifdef HAVE_ZLIB
1632          else if (d != NULL && d->gz != NULL)
1633          {
1634             int err;
1635             char const * const errmsg = gzerror(d->gz, &err);
1636             if (err != Z_ERRNO)
1637                return FileFdError("gzwrite: %s (%d: %s)", _("Write error"), err, errmsg);
1638          }
1639 #endif
1640 #ifdef HAVE_BZ2
1641          else if (d != NULL && d->bz2 != NULL)
1642          {
1643             int err;
1644             char const * const errmsg = BZ2_bzerror(d->bz2, &err);
1645             if (err != BZ_IO_ERROR)
1646                return FileFdError("BZ2_bzwrite: %s (%d: %s)", _("Write error"), err, errmsg);
1647          }
1648 #endif
1649 #ifdef HAVE_LZMA
1650          else if (d != NULL && d->lzma != NULL)
1651             return FileFdErrno("lzma_fwrite", _("Write error"));
1652 #endif
1653          return FileFdErrno("write",_("Write error"));
1654       }
1655
1656       From = (char const *)From + Res;
1657       Size -= Res;
1658       if (d != NULL)
1659          d->seekpos += Res;
1660    }
1661    while (Res > 0 && Size > 0);
1662
1663    if (Size == 0)
1664       return true;
1665
1666    return FileFdError(_("write, still have %llu to write but couldn't"), Size);
1667 }
1668 bool FileFd::Write(int Fd, const void *From, unsigned long long Size)
1669 {
1670    ssize_t Res;
1671    errno = 0;
1672    do
1673    {
1674       Res = write(Fd,From,Size);
1675       if (Res < 0 && errno == EINTR)
1676          continue;
1677       if (Res < 0)
1678          return _error->Errno("write",_("Write error"));
1679
1680       From = (char const *)From + Res;
1681       Size -= Res;
1682    }
1683    while (Res > 0 && Size > 0);
1684
1685    if (Size == 0)
1686       return true;
1687
1688    return _error->Error(_("write, still have %llu to write but couldn't"), Size);
1689 }
1690                                                                         /*}}}*/
1691 // FileFd::Seek - Seek in the file                                      /*{{{*/
1692 // ---------------------------------------------------------------------
1693 /* */
1694 bool FileFd::Seek(unsigned long long To)
1695 {
1696    Flags &= ~HitEof;
1697
1698    if (d != NULL && (d->pipe == true || d->InternalStream() == true))
1699    {
1700       // Our poor man seeking in pipes is costly, so try to avoid it
1701       unsigned long long seekpos = Tell();
1702       if (seekpos == To)
1703          return true;
1704       else if (seekpos < To)
1705          return Skip(To - seekpos);
1706
1707       if ((d->openmode & ReadOnly) != ReadOnly)
1708          return FileFdError("Reopen is only implemented for read-only files!");
1709       d->InternalClose(FileName);
1710       if (iFd != -1)
1711          close(iFd);
1712       iFd = -1;
1713       if (TemporaryFileName.empty() == false)
1714          iFd = open(TemporaryFileName.c_str(), O_RDONLY);
1715       else if (FileName.empty() == false)
1716          iFd = open(FileName.c_str(), O_RDONLY);
1717       else
1718       {
1719          if (d->compressed_fd > 0)
1720             if (lseek(d->compressed_fd, 0, SEEK_SET) != 0)
1721                iFd = d->compressed_fd;
1722          if (iFd < 0)
1723             return FileFdError("Reopen is not implemented for pipes opened with FileFd::OpenDescriptor()!");
1724       }
1725
1726       if (OpenInternDescriptor(d->openmode, d->compressor) == false)
1727          return FileFdError("Seek on file %s because it couldn't be reopened", FileName.c_str());
1728
1729       if (To != 0)
1730          return Skip(To);
1731
1732       d->seekpos = To;
1733       return true;
1734    }
1735    off_t res;
1736 #ifdef HAVE_ZLIB
1737    if (d != NULL && d->gz)
1738       res = gzseek(d->gz,To,SEEK_SET);
1739    else
1740 #endif
1741       res = lseek(iFd,To,SEEK_SET);
1742    if (res != (off_t)To)
1743       return FileFdError("Unable to seek to %llu", To);
1744
1745    if (d != NULL)
1746       d->seekpos = To;
1747    return true;
1748 }
1749                                                                         /*}}}*/
1750 // FileFd::Skip - Seek in the file                                      /*{{{*/
1751 // ---------------------------------------------------------------------
1752 /* */
1753 bool FileFd::Skip(unsigned long long Over)
1754 {
1755    if (d != NULL && (d->pipe == true || d->InternalStream() == true))
1756    {
1757       char buffer[1024];
1758       while (Over != 0)
1759       {
1760          unsigned long long toread = std::min((unsigned long long) sizeof(buffer), Over);
1761          if (Read(buffer, toread) == false)
1762             return FileFdError("Unable to seek ahead %llu",Over);
1763          Over -= toread;
1764       }
1765       return true;
1766    }
1767
1768    off_t res;
1769 #ifdef HAVE_ZLIB
1770    if (d != NULL && d->gz != NULL)
1771       res = gzseek(d->gz,Over,SEEK_CUR);
1772    else
1773 #endif
1774       res = lseek(iFd,Over,SEEK_CUR);
1775    if (res < 0)
1776       return FileFdError("Unable to seek ahead %llu",Over);
1777    if (d != NULL)
1778       d->seekpos = res;
1779
1780    return true;
1781 }
1782                                                                         /*}}}*/
1783 // FileFd::Truncate - Truncate the file                                 /*{{{*/
1784 // ---------------------------------------------------------------------
1785 /* */
1786 bool FileFd::Truncate(unsigned long long To)
1787 {
1788    // truncating /dev/null is always successful - as we get an error otherwise
1789    if (To == 0 && FileName == "/dev/null")
1790       return true;
1791 #if defined HAVE_ZLIB || defined HAVE_BZ2 || defined HAVE_LZMA
1792    if (d != NULL && (d->InternalStream() == true
1793 #ifdef HAVE_ZLIB
1794             || d->gz != NULL
1795 #endif
1796             ))
1797       return FileFdError("Truncating compressed files is not implemented (%s)", FileName.c_str());
1798 #endif
1799    if (ftruncate(iFd,To) != 0)
1800       return FileFdError("Unable to truncate to %llu",To);
1801
1802    return true;
1803 }
1804                                                                         /*}}}*/
1805 // FileFd::Tell - Current seek position                                 /*{{{*/
1806 // ---------------------------------------------------------------------
1807 /* */
1808 unsigned long long FileFd::Tell()
1809 {
1810    // In theory, we could just return seekpos here always instead of
1811    // seeking around, but not all users of FileFd use always Seek() and co
1812    // so d->seekpos isn't always true and we can just use it as a hint if
1813    // we have nothing else, but not always as an authority…
1814    if (d != NULL && (d->pipe == true || d->InternalStream() == true))
1815       return d->seekpos;
1816
1817    off_t Res;
1818 #ifdef HAVE_ZLIB
1819    if (d != NULL && d->gz != NULL)
1820      Res = gztell(d->gz);
1821    else
1822 #endif
1823      Res = lseek(iFd,0,SEEK_CUR);
1824    if (Res == (off_t)-1)
1825       FileFdErrno("lseek","Failed to determine the current file position");
1826    if (d != NULL)
1827       d->seekpos = Res;
1828    return Res;
1829 }
1830                                                                         /*}}}*/
1831 static bool StatFileFd(char const * const msg, int const iFd, std::string const &FileName, struct stat &Buf, FileFdPrivate * const d) /*{{{*/
1832 {
1833    bool ispipe = (d != NULL && d->pipe == true);
1834    if (ispipe == false)
1835    {
1836       if (fstat(iFd,&Buf) != 0)
1837          // higher-level code will generate more meaningful messages,
1838          // even translated this would be meaningless for users
1839          return _error->Errno("fstat", "Unable to determine %s for fd %i", msg, iFd);
1840       if (FileName.empty() == false)
1841          ispipe = S_ISFIFO(Buf.st_mode);
1842    }
1843
1844    // for compressor pipes st_size is undefined and at 'best' zero
1845    if (ispipe == true)
1846    {
1847       // we set it here, too, as we get the info here for free
1848       // in theory the Open-methods should take care of it already
1849       if (d != NULL)
1850          d->pipe = true;
1851       if (stat(FileName.c_str(), &Buf) != 0)
1852          return _error->Errno("fstat", "Unable to determine %s for file %s", msg, FileName.c_str());
1853    }
1854    return true;
1855 }
1856                                                                         /*}}}*/
1857 // FileFd::FileSize - Return the size of the file                       /*{{{*/
1858 unsigned long long FileFd::FileSize()
1859 {
1860    struct stat Buf;
1861    if (StatFileFd("file size", iFd, FileName, Buf, d) == false)
1862    {
1863       Flags |= Fail;
1864       return 0;
1865    }
1866    return Buf.st_size;
1867 }
1868                                                                         /*}}}*/
1869 // FileFd::ModificationTime - Return the time of last touch             /*{{{*/
1870 time_t FileFd::ModificationTime()
1871 {
1872    struct stat Buf;
1873    if (StatFileFd("modification time", iFd, FileName, Buf, d) == false)
1874    {
1875       Flags |= Fail;
1876       return 0;
1877    }
1878    return Buf.st_mtime;
1879 }
1880                                                                         /*}}}*/
1881 // FileFd::Size - Return the size of the content in the file            /*{{{*/
1882 // ---------------------------------------------------------------------
1883 /* */
1884 unsigned long long FileFd::Size()
1885 {
1886    unsigned long long size = FileSize();
1887
1888    // for compressor pipes st_size is undefined and at 'best' zero,
1889    // so we 'read' the content and 'seek' back - see there
1890    if (d != NULL && (d->pipe == true || (d->InternalStream() == true && size > 0)))
1891    {
1892       unsigned long long const oldSeek = Tell();
1893       char ignore[1000];
1894       unsigned long long read = 0;
1895       do {
1896          if (Read(ignore, sizeof(ignore), &read) == false)
1897          {
1898             Seek(oldSeek);
1899             return 0;
1900          }
1901       } while(read != 0);
1902       size = Tell();
1903       Seek(oldSeek);
1904    }
1905 #ifdef HAVE_ZLIB
1906    // only check gzsize if we are actually a gzip file, just checking for
1907    // "gz" is not sufficient as uncompressed files could be opened with
1908    // gzopen in "direct" mode as well
1909    else if (d != NULL && d->gz && !gzdirect(d->gz) && size > 0)
1910    {
1911        off_t const oldPos = lseek(iFd,0,SEEK_CUR);
1912        /* unfortunately zlib.h doesn't provide a gzsize(), so we have to do
1913         * this ourselves; the original (uncompressed) file size is the last 32
1914         * bits of the file */
1915        // FIXME: Size for gz-files is limited by 32bit… no largefile support
1916        if (lseek(iFd, -4, SEEK_END) < 0)
1917        {
1918           FileFdErrno("lseek","Unable to seek to end of gzipped file");
1919           return 0;
1920        }
1921        uint32_t size = 0;
1922        if (read(iFd, &size, 4) != 4)
1923        {
1924           FileFdErrno("read","Unable to read original size of gzipped file");
1925           return 0;
1926        }
1927        size = le32toh(size);
1928
1929        if (lseek(iFd, oldPos, SEEK_SET) < 0)
1930        {
1931           FileFdErrno("lseek","Unable to seek in gzipped file");
1932           return 0;
1933        }
1934
1935        return size;
1936    }
1937 #endif
1938
1939    return size;
1940 }
1941                                                                         /*}}}*/
1942 // FileFd::Close - Close the file if the close flag is set              /*{{{*/
1943 // ---------------------------------------------------------------------
1944 /* */
1945 bool FileFd::Close()
1946 {
1947    if (iFd == -1)
1948       return true;
1949
1950    bool Res = true;
1951    if ((Flags & AutoClose) == AutoClose)
1952    {
1953       if ((Flags & Compressed) != Compressed && iFd > 0 && close(iFd) != 0)
1954          Res &= _error->Errno("close",_("Problem closing the file %s"), FileName.c_str());
1955       if (d != NULL)
1956       {
1957          Res &= d->CloseDown(FileName);
1958          delete d;
1959          d = NULL;
1960       }
1961    }
1962
1963    if ((Flags & Replace) == Replace) {
1964       if (rename(TemporaryFileName.c_str(), FileName.c_str()) != 0)
1965          Res &= _error->Errno("rename",_("Problem renaming the file %s to %s"), TemporaryFileName.c_str(), FileName.c_str());
1966
1967       FileName = TemporaryFileName; // for the unlink() below.
1968       TemporaryFileName.clear();
1969    }
1970
1971    iFd = -1;
1972
1973    if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail &&
1974        FileName.empty() == false)
1975       if (unlink(FileName.c_str()) != 0)
1976          Res &= _error->WarningE("unlnk",_("Problem unlinking the file %s"), FileName.c_str());
1977
1978    if (Res == false)
1979       Flags |= Fail;
1980    return Res;
1981 }
1982                                                                         /*}}}*/
1983 // FileFd::Sync - Sync the file                                         /*{{{*/
1984 // ---------------------------------------------------------------------
1985 /* */
1986 bool FileFd::Sync()
1987 {
1988    if (fsync(iFd) != 0)
1989       return FileFdErrno("sync",_("Problem syncing the file"));
1990    return true;
1991 }
1992                                                                         /*}}}*/
1993 // FileFd::FileFdErrno - set Fail and call _error->Errno                *{{{*/
1994 bool FileFd::FileFdErrno(const char *Function, const char *Description,...)
1995 {
1996    Flags |= Fail;
1997    va_list args;
1998    size_t msgSize = 400;
1999    int const errsv = errno;
2000    while (true)
2001    {
2002       va_start(args,Description);
2003       if (_error->InsertErrno(GlobalError::ERROR, Function, Description, args, errsv, msgSize) == false)
2004          break;
2005       va_end(args);
2006    }
2007    return false;
2008 }
2009                                                                         /*}}}*/
2010 // FileFd::FileFdError - set Fail and call _error->Error                *{{{*/
2011 bool FileFd::FileFdError(const char *Description,...) {
2012    Flags |= Fail;
2013    va_list args;
2014    size_t msgSize = 400;
2015    while (true)
2016    {
2017       va_start(args,Description);
2018       if (_error->Insert(GlobalError::ERROR, Description, args, msgSize) == false)
2019          break;
2020       va_end(args);
2021    }
2022    return false;
2023 }
2024                                                                         /*}}}*/
2025
2026 APT_DEPRECATED gzFile FileFd::gzFd() {
2027 #ifdef HAVE_ZLIB
2028    return d->gz;
2029 #else
2030    return NULL;
2031 #endif
2032 }
2033
2034 // Glob - wrapper around "glob()"                                       /*{{{*/
2035 std::vector<std::string> Glob(std::string const &pattern, int flags)
2036 {
2037    std::vector<std::string> result;
2038    glob_t globbuf;
2039    int glob_res;
2040    unsigned int i;
2041
2042    glob_res = glob(pattern.c_str(),  flags, NULL, &globbuf);
2043
2044    if (glob_res != 0)
2045    {
2046       if(glob_res != GLOB_NOMATCH) {
2047          _error->Errno("glob", "Problem with glob");
2048          return result;
2049       }
2050    }
2051
2052    // append results
2053    for(i=0;i<globbuf.gl_pathc;i++)
2054       result.push_back(string(globbuf.gl_pathv[i]));
2055
2056    globfree(&globbuf);
2057    return result;
2058 }
2059                                                                         /*}}}*/
2060 std::string GetTempDir()                                                /*{{{*/
2061 {
2062    const char *tmpdir = getenv("TMPDIR");
2063
2064 #ifdef P_tmpdir
2065    if (!tmpdir)
2066       tmpdir = P_tmpdir;
2067 #endif
2068
2069    struct stat st;
2070    if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set
2071          stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0 || // exists and is directory
2072          access(tmpdir, R_OK | W_OK | X_OK) != 0 // current user has rwx access to directory
2073       )
2074       tmpdir = "/tmp";
2075
2076    return string(tmpdir);
2077 }
2078                                                                         /*}}}*/
2079 FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)    /*{{{*/
2080 {
2081    char fn[512];
2082    FileFd *Fd = new FileFd();
2083
2084    std::string tempdir = GetTempDir();
2085    snprintf(fn, sizeof(fn), "%s/%s.XXXXXX",
2086             tempdir.c_str(), Prefix.c_str());
2087    int fd = mkstemp(fn);
2088    if(ImmediateUnlink)
2089       unlink(fn);
2090    if (fd < 0)
2091    {
2092       _error->Errno("GetTempFile",_("Unable to mkstemp %s"), fn);
2093       return NULL;
2094    }
2095    if (!Fd->OpenDescriptor(fd, FileFd::WriteOnly, FileFd::None, true))
2096    {
2097       _error->Errno("GetTempFile",_("Unable to write to %s"),fn);
2098       return NULL;
2099    }
2100
2101    return Fd;
2102 }
2103                                                                         /*}}}*/
2104 bool Rename(std::string From, std::string To)                           /*{{{*/
2105 {
2106    if (rename(From.c_str(),To.c_str()) != 0)
2107    {
2108       _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno),
2109                     From.c_str(),To.c_str());
2110       return false;
2111    }
2112    return true;
2113 }
2114                                                                         /*}}}*/
2115 bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/*{{{*/
2116 {
2117    int fd;
2118    if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly)
2119       return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only");
2120
2121    int Pipe[2] = {-1, -1};
2122    if(pipe(Pipe) != 0)
2123       return _error->Errno("pipe", _("Failed to create subprocess IPC"));
2124
2125    std::set<int> keep_fds;
2126    keep_fds.insert(Pipe[0]);
2127    keep_fds.insert(Pipe[1]);
2128    Child = ExecFork(keep_fds);
2129    if(Child < 0)
2130       return _error->Errno("fork", "Failed to fork");
2131    if(Child == 0)
2132    {
2133       if(Mode == FileFd::ReadOnly)
2134       {
2135          close(Pipe[0]);
2136          fd = Pipe[1];
2137       }
2138       else if(Mode == FileFd::WriteOnly)
2139       {
2140          close(Pipe[1]);
2141          fd = Pipe[0];
2142       }
2143
2144       if(Mode == FileFd::ReadOnly)
2145       {
2146          dup2(fd, 1);
2147          dup2(fd, 2);
2148       } else if(Mode == FileFd::WriteOnly)
2149          dup2(fd, 0);
2150
2151       execv(Args[0], (char**)Args);
2152       _exit(100);
2153    }
2154    if(Mode == FileFd::ReadOnly)
2155    {
2156       close(Pipe[1]);
2157       fd = Pipe[0];
2158    } else if(Mode == FileFd::WriteOnly)
2159    {
2160       close(Pipe[0]);
2161       fd = Pipe[1];
2162    }
2163    Fd.OpenDescriptor(fd, Mode, FileFd::None, true);
2164
2165    return true;
2166 }
2167                                                                         /*}}}*/
2168 bool DropPrivileges()                                                   /*{{{*/
2169 {
2170    if(_config->FindB("Debug::NoDropPrivs", false) == true)
2171       return true;
2172
2173 #if __gnu_linux__
2174 #if defined(PR_SET_NO_NEW_PRIVS) && ( PR_SET_NO_NEW_PRIVS != 38 )
2175 #error "PR_SET_NO_NEW_PRIVS is defined, but with a different value than expected!"
2176 #endif
2177    // see prctl(2), needs linux3.5 at runtime - magic constant to avoid it at buildtime
2178    int ret = prctl(38, 1, 0, 0, 0);
2179    // ignore EINVAL - kernel is too old to understand the option
2180    if(ret < 0 && errno != EINVAL)
2181       _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
2182 #endif
2183
2184    // empty setting disables privilege dropping - this also ensures
2185    // backward compatibility, see bug #764506
2186    const std::string toUser = _config->Find("APT::Sandbox::User");
2187    if (toUser.empty())
2188       return true;
2189
2190    // uid will be 0 in the end, but gid might be different anyway
2191    uid_t const old_uid = getuid();
2192    gid_t const old_gid = getgid();
2193
2194    if (old_uid != 0)
2195       return true;
2196
2197    struct passwd *pw = getpwnam(toUser.c_str());
2198    if (pw == NULL)
2199       return _error->Error("No user %s, can not drop rights", toUser.c_str());
2200
2201    // Do not change the order here, it might break things
2202    if (setgroups(1, &pw->pw_gid))
2203       return _error->Errno("setgroups", "Failed to setgroups");
2204
2205    if (setegid(pw->pw_gid) != 0)
2206       return _error->Errno("setegid", "Failed to setegid");
2207
2208    if (setgid(pw->pw_gid) != 0)
2209       return _error->Errno("setgid", "Failed to setgid");
2210
2211    if (setuid(pw->pw_uid) != 0)
2212       return _error->Errno("setuid", "Failed to setuid");
2213
2214    // the seteuid() is probably uneeded (at least thats what the linux
2215    // man-page says about setuid(2)) but we cargo culted it anyway
2216    if (seteuid(pw->pw_uid) != 0)
2217       return _error->Errno("seteuid", "Failed to seteuid");
2218
2219    // Verify that the user has only a single group, and the correct one
2220    gid_t groups[1];
2221    if (getgroups(1, groups) != 1)
2222       return _error->Errno("getgroups", "Could not get new groups");
2223    if (groups[0] != pw->pw_gid)
2224       return _error->Error("Could not switch group");
2225
2226    // Verify that gid, egid, uid, and euid changed
2227    if (getgid() != pw->pw_gid)
2228       return _error->Error("Could not switch group");
2229    if (getegid() != pw->pw_gid)
2230       return _error->Error("Could not switch effective group");
2231    if (getuid() != pw->pw_uid)
2232       return _error->Error("Could not switch user");
2233    if (geteuid() != pw->pw_uid)
2234       return _error->Error("Could not switch effective user");
2235
2236 #ifdef HAVE_GETRESUID
2237    // verify that the saved set-user-id was changed as well
2238    uid_t ruid = 0;
2239    uid_t euid = 0;
2240    uid_t suid = 0;
2241    if (getresuid(&ruid, &euid, &suid))
2242       return _error->Errno("getresuid", "Could not get saved set-user-ID");
2243    if (suid != pw->pw_uid)
2244       return _error->Error("Could not switch saved set-user-ID");
2245 #endif
2246
2247 #ifdef HAVE_GETRESGID
2248    // verify that the saved set-group-id was changed as well
2249    gid_t rgid = 0;
2250    gid_t egid = 0;
2251    gid_t sgid = 0;
2252    if (getresgid(&rgid, &egid, &sgid))
2253       return _error->Errno("getresuid", "Could not get saved set-group-ID");
2254    if (sgid != pw->pw_gid)
2255       return _error->Error("Could not switch saved set-group-ID");
2256 #endif
2257
2258    // Check that uid and gid changes do not work anymore
2259    if (pw->pw_gid != old_gid && (setgid(old_gid) != -1 || setegid(old_gid) != -1))
2260       return _error->Error("Could restore a gid to root, privilege dropping did not work");
2261
2262    if (pw->pw_uid != old_uid && (setuid(old_uid) != -1 || seteuid(old_uid) != -1))
2263       return _error->Error("Could restore a uid to root, privilege dropping did not work");
2264
2265    return true;
2266 }
2267                                                                         /*}}}*/