apt-inst/deb/dpkgdb.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: dpkgdb.cc,v 1.2 2001/02/20 07:03:17 jgg Exp $
   4 /* ######################################################################
   5
   6    DPKGv1 Database Implemenation
   7
   8    This class provides parsers and other implementations for the DPKGv1
   9    database. It reads the diversion file, the list files and the status
  10    file to build both the list of currently installed files and the
  11    currently installed package list.
  12
  13    ##################################################################### */
  14                                                                         /*}}}*/
  15 // Include Files                                                        /*{{{*/
  16 #ifdef __GNUG__
  17 #pragma implementation "apt-pkg/dpkgdb.h"
  18 #endif
  19
  20 #include <apt-pkg/dpkgdb.h>
  21 #include <apt-pkg/configuration.h>
  22 #include <apt-pkg/error.h>
  23 #include <apt-pkg/progress.h>
  24 #include <apt-pkg/tagfile.h>
  25 #include <apt-pkg/strutl.h>
  26
  27 #include <stdio.h>
  28 #include <errno.h>
  29 #include <sys/stat.h>
  30 #include <sys/mman.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33                                                                         /*}}}*/
  34
  35 // EraseDir - Erase A Directory                                         /*{{{*/
  36 // ---------------------------------------------------------------------
  37 /* This is necessary to create a new empty sub directory. The caller should
  38    invoke mkdir after this with the proper permissions and check for
  39    error. Maybe stick this in fileutils */
  40 static bool EraseDir(const char *Dir)
  41 {
  42    // First we try a simple RM
  43    if (rmdir(Dir) == 0 ||
  44        errno == ENOENT)
  45       return true;
  46
  47    // A file? Easy enough..
  48    if (errno == ENOTDIR)
  49    {
  50       if (unlink(Dir) != 0)
  51          return _error->Errno("unlink","Failed to remove %s",Dir);
  52       return true;
  53    }
  54
  55    // Should not happen
  56    if (errno != ENOTEMPTY)
  57       return _error->Errno("rmdir","Failed to remove %s",Dir);
  58
  59    // Purge it using rm
  60    int Pid = ExecFork();
  61
  62    // Spawn the subprocess
  63    if (Pid == 0)
  64    {
  65       execlp(_config->Find("Dir::Bin::rm","/bin/rm").c_str(),
  66              "rm","-rf","--",Dir,0);
  67       _exit(100);
  68    }
  69    return ExecWait(Pid,_config->Find("dir::bin::rm","/bin/rm").c_str());
  70 }
  71                                                                         /*}}}*/
  72 // DpkgDB::debDpkgDB - Constructor                                      /*{{{*/
  73 // ---------------------------------------------------------------------
  74 /* */
  75 debDpkgDB::debDpkgDB() : CacheMap(0), FileMap(0)
  76 {
  77    AdminDir = flNotFile(_config->Find("Dir::State::status"));
  78    DiverInode = 0;
  79    DiverTime = 0;
  80 }
  81                                                                         /*}}}*/
  82 // DpkgDB::~debDpkgDB - Destructor                                      /*{{{*/
  83 // ---------------------------------------------------------------------
  84 /* */
  85 debDpkgDB::~debDpkgDB()
  86 {
  87    delete Cache;
  88    Cache = 0;
  89    delete CacheMap;
  90    CacheMap = 0;
  91
  92    delete FList;
  93    FList = 0;
  94    delete FileMap;
  95    FileMap = 0;
  96 }
  97                                                                         /*}}}*/
  98 // DpkgDB::InitMetaTmp - Get the temp dir for meta information          /*{{{*/
  99 // ---------------------------------------------------------------------
 100 /* This creats+empties the meta temporary directory /var/lib/dpkg/tmp.ci
 101    Only one package at a time can be using the returned meta directory. */
 102 bool debDpkgDB::InitMetaTmp(string &Dir)
 103 {
 104    string Tmp = AdminDir + "tmp.ci/";
 105    if (EraseDir(Tmp.c_str()) == false)
 106       return _error->Error("Unable to create %s",Tmp.c_str());
 107    if (mkdir(Tmp.c_str(),0755) != 0)
 108       return _error->Errno("mkdir","Unable to create %s",Tmp.c_str());
 109
 110    // Verify it is on the same filesystem as the main info directory
 111    dev_t Dev;
 112    struct stat St;
 113    if (stat((AdminDir + "info").c_str(),&St) != 0)
 114       return _error->Errno("stat","Failed to stat %sinfo",AdminDir.c_str());
 115    Dev = St.st_dev;
 116    if (stat(Tmp.c_str(),&St) != 0)
 117       return _error->Errno("stat","Failed to stat %s",Tmp.c_str());
 118    if (Dev != St.st_dev)
 119       return _error->Error("The info and temp directories need to be on the same filesystem");
 120
 121    // Done
 122    Dir = Tmp;
 123    return true;
 124 }
 125                                                                         /*}}}*/
 126 // DpkgDB::ReadyPkgCache - Prepare the cache with the current status    /*{{{*/
 127 // ---------------------------------------------------------------------
 128 /* This reads in the status file into an empty cache. This really needs
 129    to be somehow unified with the high level APT notion of the Database
 130    directory, but there is no clear way on how to do that yet. */
 131 bool debDpkgDB::ReadyPkgCache(OpProgress &Progress)
 132 {
 133    if (Cache != 0)
 134    {
 135       Progress.OverallProgress(1,1,1,"Reading Package Lists");
 136       return true;
 137    }
 138
 139    if (CacheMap != 0)
 140    {
 141       delete CacheMap;
 142       CacheMap = 0;
 143    }
 144
 145    if (pkgMakeOnlyStatusCache(Progress,&CacheMap) == false)
 146       return false;
 147    Cache->DropProgress();
 148
 149    return true;
 150 }
 151                                                                         /*}}}*/
 152 // DpkgDB::ReadFList - Read the File Listings in                        /*{{{*/
 153 // ---------------------------------------------------------------------
 154 /* This reads the file listing in from the state directory. This is a
 155    performance critical routine, as it needs to parse about 50k lines of
 156    text spread over a hundred or more files. For an initial cold start
 157    most of the time is spent in reading file inodes and so on, not
 158    actually parsing. */
 159 bool debDpkgDB::ReadFList(OpProgress &Progress)
 160 {
 161    // Count the number of packages we need to read information for
 162    unsigned long Total = 0;
 163    pkgCache &Cache = this->Cache->GetCache();
 164    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 165    {
 166       // Only not installed packages have no files.
 167       if (I->CurrentState == pkgCache::State::NotInstalled)
 168          continue;
 169       Total++;
 170    }
 171
 172    /* Switch into the admin dir, this prevents useless lookups for the
 173       path components */
 174    string Cwd = SafeGetCWD();
 175    if (chdir((AdminDir + "info/").c_str()) != 0)
 176       return _error->Errno("chdir","Failed to change to the admin dir %sinfo",AdminDir.c_str());
 177
 178    // Allocate a buffer. Anything larger than this buffer will be mmaped
 179    unsigned long BufSize = 32*1024;
 180    char *Buffer = new char[BufSize];
 181
 182    // Begin Loading them
 183    unsigned long Count = 0;
 184    char Name[300];
 185    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 186    {
 187       /* Only not installed packages have no files. ConfFile packages have
 188          file lists but we don't want to read them in */
 189       if (I->CurrentState == pkgCache::State::NotInstalled ||
 190           I->CurrentState == pkgCache::State::ConfigFiles)
 191          continue;
 192
 193       // Fetch a package handle to associate with the file
 194       pkgFLCache::PkgIterator FlPkg = FList->GetPkg(I.Name(),0,true);
 195       if (FlPkg.end() == true)
 196       {
 197          _error->Error("Internal Error getting a Package Name");
 198          break;
 199       }
 200
 201       Progress.OverallProgress(Count,Total,1,"Reading File Listing");
 202
 203       // Open the list file
 204       snprintf(Name,sizeof(Name),"%s.list",I.Name());
 205       int Fd = open(Name,O_RDONLY);
 206
 207       /* Okay this is very strange and bad.. Best thing is to bail and
 208          instruct the user to look into it. */
 209       struct stat Stat;
 210       if (Fd == -1 || fstat(Fd,&Stat) != 0)
 211       {
 212          _error->Errno("open","Failed to open the list file '%sinfo/%s'. If you "
 213                        "cannot restore this file then make it empty "
 214                        "and immediately re-install the same version of the package!",
 215                        AdminDir.c_str(),Name);
 216          break;
 217       }
 218
 219       // Set File to be a memory buffer containing the whole file
 220       char *File;
 221       if ((unsigned)Stat.st_size < BufSize)
 222       {
 223          if (read(Fd,Buffer,Stat.st_size) != Stat.st_size)
 224          {
 225             _error->Errno("read","Failed reading the list file %sinfo/%s",
 226                           AdminDir.c_str(),Name);
 227             close(Fd);
 228             break;
 229          }
 230          File = Buffer;
 231       }
 232       else
 233       {
 234          // Use mmap
 235          File = (char *)mmap(0,Stat.st_size,PROT_READ,MAP_PRIVATE,Fd,0);
 236          if (File == (char *)(-1))
 237          {
 238             _error->Errno("mmap","Failed reading the list file %sinfo/%s",
 239                           AdminDir.c_str(),Name);
 240             close(Fd);
 241             break;
 242          }
 243       }
 244
 245       // Parse it
 246       const char *Start = File;
 247       const char *End = File;
 248       const char *Finish = File + Stat.st_size;
 249       for (; End < Finish; End++)
 250       {
 251          // Not an end of line
 252          if (*End != '\n' && End + 1 < Finish)
 253             continue;
 254
 255          // Skip blank lines
 256          if (End - Start > 1)
 257          {
 258             pkgFLCache::NodeIterator Node = FList->GetNode(Start,End,
 259                                               FlPkg.Offset(),true,false);
 260             if (Node.end() == true)
 261             {
 262                _error->Error("Internal Error getting a Node");
 263                break;
 264             }
 265          }
 266
 267          // Skip past the end of line
 268          for (; *End == '\n' && End < Finish; End++);
 269          Start = End;
 270       }
 271
 272       close(Fd);
 273       if ((unsigned)Stat.st_size >= BufSize)
 274          munmap((caddr_t)File,Stat.st_size);
 275
 276       // Failed
 277       if (End < Finish)
 278          break;
 279
 280       Count++;
 281    }
 282
 283    delete [] Buffer;
 284    if (chdir(Cwd.c_str()) != 0)
 285       chdir("/");
 286
 287    return !_error->PendingError();
 288 }
 289                                                                         /*}}}*/
 290 // DpkgDB::ReadDiversions - Load the diversions file                    /*{{{*/
 291 // ---------------------------------------------------------------------
 292 /* Read the diversion file in from disk. This is usually invoked by
 293    LoadChanges before performing an operation that uses the FLCache. */
 294 bool debDpkgDB::ReadDiversions()
 295 {
 296    struct stat Stat;
 297    if (stat((AdminDir + "diversions").c_str(),&Stat) != 0)
 298       return true;
 299
 300    if (_error->PendingError() == true)
 301       return false;
 302
 303    FILE *Fd = fopen((AdminDir + "diversions").c_str(),"r");
 304    if (Fd == 0)
 305       return _error->Errno("fopen","Failed to open the diversions file %sdiversions",AdminDir.c_str());
 306
 307    FList->BeginDiverLoad();
 308    while (1)
 309    {
 310       char From[300];
 311       char To[300];
 312       char Package[100];
 313
 314       // Read the three lines in
 315       if (fgets(From,sizeof(From),Fd) == 0)
 316          break;
 317       if (fgets(To,sizeof(To),Fd) == 0 ||
 318           fgets(Package,sizeof(Package),Fd) == 0)
 319       {
 320          _error->Error("The diversion file is corrupted");
 321          break;
 322       }
 323
 324       // Strip the \ns
 325       unsigned long Len = strlen(From);
 326       if (Len < 2 || From[Len-1] != '\n')
 327          _error->Error("Invalid line in the diversion file: %s",From);
 328       else
 329          From[Len-1] = 0;
 330       Len = strlen(To);
 331       if (Len < 2 || To[Len-1] != '\n')
 332          _error->Error("Invalid line in the diversion file: %s",To);
 333       else
 334          To[Len-1] = 0;
 335       Len = strlen(Package);
 336       if (Len < 2 || Package[Len-1] != '\n')
 337          _error->Error("Invalid line in the diversion file: %s",Package);
 338       else
 339          Package[Len-1] = 0;
 340
 341       // Make sure the lines were parsed OK
 342       if (_error->PendingError() == true)
 343          break;
 344
 345       // Fetch a package
 346       if (strcmp(Package,":") == 0)
 347          Package[0] = 0;
 348       pkgFLCache::PkgIterator FlPkg = FList->GetPkg(Package,0,true);
 349       if (FlPkg.end() == true)
 350       {
 351          _error->Error("Internal Error getting a Package Name");
 352          break;
 353       }
 354
 355       // Install the diversion
 356       if (FList->AddDiversion(FlPkg,From,To) == false)
 357       {
 358          _error->Error("Internal Error adding a diversion");
 359          break;
 360       }
 361    }
 362    if (_error->PendingError() == false)
 363       FList->FinishDiverLoad();
 364
 365    DiverInode = Stat.st_ino;
 366    DiverTime = Stat.st_mtime;
 367
 368    fclose(Fd);
 369    return !_error->PendingError();
 370 }
 371                                                                         /*}}}*/
 372 // DpkgDB::ReadFileList - Read the file listing                         /*{{{*/
 373 // ---------------------------------------------------------------------
 374 /* Read in the file listing. The file listing is created from three
 375    sources, *.list, Conffile sections and the Diversion table. */
 376 bool debDpkgDB::ReadyFileList(OpProgress &Progress)
 377 {
 378    if (Cache == 0)
 379       return _error->Error("The pkg cache must be initialize first");
 380    if (FList != 0)
 381    {
 382       Progress.OverallProgress(1,1,1,"Reading File List");
 383       return true;
 384    }
 385
 386    // Create the cache and read in the file listing
 387    FileMap = new DynamicMMap(MMap::Public);
 388    FList = new pkgFLCache(*FileMap);
 389    if (_error->PendingError() == true ||
 390        ReadFList(Progress) == false ||
 391        ReadConfFiles() == false ||
 392        ReadDiversions() == false)
 393    {
 394       delete FList;
 395       delete FileMap;
 396       FileMap = 0;
 397       FList = 0;
 398       return false;
 399    }
 400
 401    cout << "Node: " << FList->HeaderP->NodeCount << ',' << FList->HeaderP->UniqNodes << endl;
 402    cout << "Dir: " << FList->HeaderP->DirCount << endl;
 403    cout << "Package: " << FList->HeaderP->PackageCount << endl;
 404    cout << "HashSize: " << FList->HeaderP->HashSize << endl;
 405    cout << "Size: " << FileMap->Size() << endl;
 406    cout << endl;
 407
 408    return true;
 409 }
 410                                                                         /*}}}*/
 411 // DpkgDB::ReadConfFiles - Read the conf file sections from the s-file  /*{{{*/
 412 // ---------------------------------------------------------------------
 413 /* Reading the conf files is done by reparsing the status file. This is
 414    actually rather fast so it is no big deal. */
 415 bool debDpkgDB::ReadConfFiles()
 416 {
 417    FileFd File(_config->FindFile("Dir::State::status"),FileFd::ReadOnly);
 418    pkgTagFile Tags(&File);
 419    if (_error->PendingError() == true)
 420       return false;
 421
 422    pkgTagSection Section;
 423    while (1)
 424    {
 425       // Skip to the next section
 426       unsigned long Offset = Tags.Offset();
 427       if (Tags.Step(Section) == false)
 428          break;
 429
 430       // Parse the line
 431       const char *Start;
 432       const char *Stop;
 433       if (Section.Find("Conffiles",Start,Stop) == false)
 434          continue;
 435
 436       const char *PkgStart;
 437       const char *PkgEnd;
 438       if (Section.Find("Package",PkgStart,PkgEnd) == false)
 439          return _error->Error("Failed to find a Package: Header, offset %lu",Offset);
 440
 441       // Snag a package record for it
 442       pkgFLCache::PkgIterator FlPkg = FList->GetPkg(PkgStart,PkgEnd,true);
 443       if (FlPkg.end() == true)
 444          return _error->Error("Internal Error getting a Package Name");
 445
 446       // Parse the conf file lines
 447       while (1)
 448       {
 449          for (; isspace(*Start) != 0 && Start < Stop; Start++);
 450          if (Start == Stop)
 451             break;
 452
 453          // Split it into words
 454          const char *End = Start;
 455          for (; isspace(*End) == 0 && End < Stop; End++);
 456          const char *StartMd5 = End;
 457          for (; isspace(*StartMd5) != 0 && StartMd5 < Stop; StartMd5++);
 458          const char *EndMd5 = StartMd5;
 459          for (; isspace(*EndMd5) == 0 && EndMd5 < Stop; EndMd5++);
 460          if (StartMd5 == EndMd5 || Start == End)
 461             return _error->Error("Bad ConfFile section in the status file. Offset %lu",Offset);
 462
 463          // Insert a new entry
 464          unsigned char MD5[16];
 465          if (Hex2Num(StartMd5,EndMd5,MD5,16) == false)
 466             return _error->Error("Error parsing MD5. Offset %lu",Offset);
 467
 468          if (FList->AddConfFile(Start,End,FlPkg,MD5) == false)
 469             return false;
 470          Start = EndMd5;
 471       }
 472    }
 473
 474    return true;
 475 }
 476                                                                         /*}}}*/
 477 // DpkgDB::LoadChanges - Read in any changed state files                /*{{{*/
 478 // ---------------------------------------------------------------------
 479 /* The only file in the dpkg system that can change while packages are
 480    unpacking is the diversions file. */
 481 bool debDpkgDB::LoadChanges()
 482 {
 483    struct stat Stat;
 484    if (stat((AdminDir + "diversions").c_str(),&Stat) != 0)
 485       return true;
 486    if (DiverInode == Stat.st_ino && DiverTime == Stat.st_mtime)
 487       return true;
 488    return ReadDiversions();
 489 }
 490                                                                         /*}}}*/