ftparchive/cachedb.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: cachedb.cc,v 1.7 2004/05/08 19:41:01 mdz Exp $
   4 /* ######################################################################
   5
   6    CacheDB
   7
   8    Simple uniform interface to a cache database.
   9
  10    ##################################################################### */
  11                                                                         /*}}}*/
  12 // Include Files                                                        /*{{{*/
  13 #ifdef __GNUG__
  14 #pragma implementation "cachedb.h"
  15 #endif
  16
  17 #include "cachedb.h"
  18
  19 #include <apti18n.h>
  20 #include <apt-pkg/error.h>
  21 #include <apt-pkg/md5.h>
  22 #include <apt-pkg/sha1.h>
  23 #include <apt-pkg/sha256.h>
  24 #include <apt-pkg/strutl.h>
  25 #include <apt-pkg/configuration.h>
  26
  27 #include <netinet/in.h>       // htonl, etc
  28                                                                         /*}}}*/
  29
  30 // CacheDB::ReadyDB - Ready the DB2                                     /*{{{*/
  31 // ---------------------------------------------------------------------
  32 /* This opens the DB2 file for caching package information */
  33 bool CacheDB::ReadyDB(string DB)
  34 {
  35    int err;
  36
  37    ReadOnly = _config->FindB("APT::FTPArchive::ReadOnlyDB",false);
  38
  39    // Close the old DB
  40    if (Dbp != 0)
  41       Dbp->close(Dbp,0);
  42
  43    /* Check if the DB was disabled while running and deal with a
  44       corrupted DB */
  45    if (DBFailed() == true)
  46    {
  47       _error->Warning(_("DB was corrupted, file renamed to %s.old"),DBFile.c_str());
  48       rename(DBFile.c_str(),(DBFile+".old").c_str());
  49    }
  50
  51    DBLoaded = false;
  52    Dbp = 0;
  53    DBFile = string();
  54
  55    if (DB.empty())
  56       return true;
  57
  58    db_create(&Dbp, NULL, 0);
  59    if ((err = Dbp->open(Dbp, NULL, DB.c_str(), NULL, DB_BTREE,
  60                         (ReadOnly?DB_RDONLY:DB_CREATE),
  61                         0644)) != 0)
  62    {
  63       if (err == DB_OLD_VERSION)
  64       {
  65           _error->Warning(_("DB is old, attempting to upgrade %s"),DBFile.c_str());
  66           err = Dbp->upgrade(Dbp, DB.c_str(), 0);
  67           if (!err)
  68              err = Dbp->open(Dbp, NULL, DB.c_str(), NULL, DB_HASH,
  69                             (ReadOnly?DB_RDONLY:DB_CREATE), 0644);
  70
  71       }
  72       // the database format has changed from DB_HASH to DB_BTREE in
  73       // apt 0.6.44
  74       if (err == EINVAL)
  75       {
  76          _error->Error(_("DB format is invalid. If you upgraded from a older version of apt, please remove and re-create the database."));
  77       }
  78       if (err)
  79       {
  80           Dbp = 0;
  81           return _error->Error(_("Unable to open DB file %s: %s"),DB.c_str(), db_strerror(err));
  82       }
  83    }
  84
  85    DBFile = DB;
  86    DBLoaded = true;
  87    return true;
  88 }
  89                                                                         /*}}}*/
  90 // CacheDB::OpenFile - Open the filei                                   /*{{{*/
  91 // ---------------------------------------------------------------------
  92 /* */
  93 bool CacheDB::OpenFile()
  94 {
  95         Fd = new FileFd(FileName,FileFd::ReadOnly);
  96         if (_error->PendingError() == true)
  97         {
  98                 delete Fd;
  99                 Fd = NULL;
 100                 return false;
 101         }
 102         return true;
 103 }
 104                                                                         /*}}}*/
 105 // CacheDB::GetFileStat - Get stats from the file                       /*{{{*/
 106 // ---------------------------------------------------------------------
 107 /* This gets the size from the database if it's there.  If we need
 108  * to look at the file, also get the mtime from the file. */
 109 bool CacheDB::GetFileStat()
 110 {
 111         if ((CurStat.Flags & FlSize) == FlSize)
 112         {
 113                 /* Already worked out the file size */
 114         }
 115         else
 116         {
 117                 /* Get it from the file. */
 118                 if (Fd == NULL && OpenFile() == false)
 119                 {
 120                         return false;
 121                 }
 122                 // Stat the file
 123                 struct stat St;
 124                 if (fstat(Fd->Fd(),&St) != 0)
 125                 {
 126                         return _error->Errno("fstat",
 127                                 _("Failed to stat %s"),FileName.c_str());
 128                 }
 129                 CurStat.FileSize = St.st_size;
 130                 CurStat.mtime = htonl(St.st_mtime);
 131                 CurStat.Flags |= FlSize;
 132         }
 133         return true;
 134 }
 135                                                                         /*}}}*/
 136 // CacheDB::GetCurStat - Set the CurStat variable.                      /*{{{*/
 137 // ---------------------------------------------------------------------
 138 /* Sets the CurStat variable.  Either to 0 if no database is used
 139  * or to the value in the database if one is used */
 140 bool CacheDB::GetCurStat()
 141 {
 142    memset(&CurStat,0,sizeof(CurStat));
 143
 144         if (DBLoaded)
 145         {
 146                 /* First see if thre is anything about it
 147                    in the database */
 148
 149                 /* Get the flags (and mtime) */
 150    InitQuery("st");
 151    // Ensure alignment of the returned structure
 152    Data.data = &CurStat;
 153    Data.ulen = sizeof(CurStat);
 154    Data.flags = DB_DBT_USERMEM;
 155                 if (Get() == false)
 156       {
 157          CurStat.Flags = 0;
 158       }
 159                 CurStat.Flags = ntohl(CurStat.Flags);
 160                 CurStat.FileSize = ntohl(CurStat.FileSize);
 161    }
 162         return true;
 163 }
 164                                                                         /*}}}*/
 165 // CacheDB::GetFileInfo - Get all the info about the file               /*{{{*/
 166 // ---------------------------------------------------------------------
 167 bool CacheDB::GetFileInfo(string FileName, bool DoControl, bool DoContents,
 168                                 bool GenContentsOnly,
 169                                 bool DoMD5, bool DoSHA1, bool DoSHA256)
 170 {
 171         this->FileName = FileName;
 172
 173         if (GetCurStat() == false)
 174    {
 175                 return false;
 176    }
 177    OldStat = CurStat;
 178
 179         if (GetFileStat() == false)
 180         {
 181                 delete Fd;
 182                 Fd = NULL;
 183                 return false;
 184         }
 185
 186         Stats.Bytes += CurStat.FileSize;
 187         Stats.Packages++;
 188
 189         if (DoControl && LoadControl() == false
 190                 || DoContents && LoadContents(GenContentsOnly) == false
 191                 || DoMD5 && GetMD5(false) == false
 192                 || DoSHA1 && GetSHA1(false) == false
 193                 || DoSHA256 && GetSHA256(false) == false)
 194         {
 195                 delete Fd;
 196                 Fd = NULL;
 197                 delete DebFile;
 198                 DebFile = NULL;
 199                 return false;
 200         }
 201
 202         delete Fd;
 203         Fd = NULL;
 204         delete DebFile;
 205         DebFile = NULL;
 206
 207    return true;
 208 }
 209                                                                         /*}}}*/
 210 // CacheDB::LoadControl - Load Control information                      /*{{{*/
 211 // ---------------------------------------------------------------------
 212 /* */
 213 bool CacheDB::LoadControl()
 214 {
 215    // Try to read the control information out of the DB.
 216    if ((CurStat.Flags & FlControl) == FlControl)
 217    {
 218       // Lookup the control information
 219       InitQuery("cl");
 220       if (Get() == true && Control.TakeControl(Data.data,Data.size) == true)
 221             return true;
 222       CurStat.Flags &= ~FlControl;
 223    }
 224
 225    if (Fd == NULL && OpenFile() == false)
 226    {
 227       return false;
 228    }
 229    // Create a deb instance to read the archive
 230    if (DebFile == 0)
 231    {
 232       DebFile = new debDebFile(*Fd);
 233       if (_error->PendingError() == true)
 234          return false;
 235    }
 236
 237    Stats.Misses++;
 238    if (Control.Read(*DebFile) == false)
 239       return false;
 240
 241    if (Control.Control == 0)
 242       return _error->Error(_("Archive has no control record"));
 243
 244    // Write back the control information
 245    InitQuery("cl");
 246    if (Put(Control.Control,Control.Length) == true)
 247       CurStat.Flags |= FlControl;
 248    return true;
 249 }
 250                                                                         /*}}}*/
 251 // CacheDB::LoadContents - Load the File Listing                        /*{{{*/
 252 // ---------------------------------------------------------------------
 253 /* */
 254 bool CacheDB::LoadContents(bool GenOnly)
 255 {
 256    // Try to read the control information out of the DB.
 257    if ((CurStat.Flags & FlContents) == FlContents)
 258    {
 259       if (GenOnly == true)
 260          return true;
 261
 262       // Lookup the contents information
 263       InitQuery("cn");
 264       if (Get() == true)
 265       {
 266          if (Contents.TakeContents(Data.data,Data.size) == true)
 267             return true;
 268       }
 269
 270       CurStat.Flags &= ~FlContents;
 271    }
 272
 273    if (Fd == NULL && OpenFile() == false)
 274    {
 275       return false;
 276    }
 277    // Create a deb instance to read the archive
 278    if (DebFile == 0)
 279    {
 280       DebFile = new debDebFile(*Fd);
 281       if (_error->PendingError() == true)
 282          return false;
 283    }
 284
 285    if (Contents.Read(*DebFile) == false)
 286       return false;
 287
 288    // Write back the control information
 289    InitQuery("cn");
 290    if (Put(Contents.Data,Contents.CurSize) == true)
 291       CurStat.Flags |= FlContents;
 292    return true;
 293 }
 294                                                                         /*}}}*/
 295
 296 static string bytes2hex(uint8_t *bytes, size_t length) {
 297    char space[65];
 298    if (length * 2 > sizeof(space) - 1) length = (sizeof(space) - 1) / 2;
 299    for (size_t i = 0; i < length; i++)
 300       snprintf(&space[i*2], 3, "%02x", bytes[i]);
 301    return string(space);
 302 }
 303
 304 static inline unsigned char xdig2num(char dig) {
 305    if (isdigit(dig)) return dig - '0';
 306    if ('a' <= dig && dig <= 'f') return dig - 'a' + 10;
 307    if ('A' <= dig && dig <= 'F') return dig - 'A' + 10;
 308    return 0;
 309 }
 310
 311 static void hex2bytes(uint8_t *bytes, const char *hex, int length) {
 312    while (length-- > 0) {
 313       *bytes = 0;
 314       if (isxdigit(hex[0]) && isxdigit(hex[1])) {
 315           *bytes = xdig2num(hex[0]) * 16 + xdig2num(hex[1]);
 316           hex += 2;
 317       }
 318       bytes++;
 319    }
 320 }
 321
 322 void *memrchr(void *data, char value, int size) {
 323     char *cdata = (char *) data;
 324     for (int i = 0; i != size; ++i)
 325         if (cdata[size - i - 1] == value)
 326             return cdata + size - i - 1;
 327     return NULL;
 328 }
 329
 330 // CacheDB::GetMD5 - Get the MD5 hash                                   /*{{{*/
 331 // ---------------------------------------------------------------------
 332 /* */
 333 bool CacheDB::GetMD5(bool GenOnly)
 334 {
 335    // Try to read the control information out of the DB.
 336    if ((CurStat.Flags & FlMD5) == FlMD5)
 337    {
 338       if (GenOnly == true)
 339          return true;
 340
 341       MD5Res = bytes2hex(CurStat.MD5, sizeof(CurStat.MD5));
 342          return true;
 343       }
 344
 345    Stats.MD5Bytes += CurStat.FileSize;
 346
 347    if (Fd == NULL && OpenFile() == false)
 348    {
 349       return false;
 350    }
 351    MD5Summation MD5;
 352    if (Fd->Seek(0) == false || MD5.AddFD(Fd->Fd(),CurStat.FileSize) == false)
 353       return false;
 354
 355    MD5Res = MD5.Result();
 356    hex2bytes(CurStat.MD5, MD5Res.data(), sizeof(CurStat.MD5));
 357       CurStat.Flags |= FlMD5;
 358    return true;
 359 }
 360                                                                         /*}}}*/
 361 // CacheDB::GetSHA1 - Get the SHA1 hash                                 /*{{{*/
 362 // ---------------------------------------------------------------------
 363 /* */
 364 bool CacheDB::GetSHA1(bool GenOnly)
 365 {
 366    // Try to read the control information out of the DB.
 367    if ((CurStat.Flags & FlSHA1) == FlSHA1)
 368    {
 369       if (GenOnly == true)
 370          return true;
 371
 372       SHA1Res = bytes2hex(CurStat.SHA1, sizeof(CurStat.SHA1));
 373       return true;
 374    }
 375
 376    Stats.SHA1Bytes += CurStat.FileSize;
 377
 378    if (Fd == NULL && OpenFile() == false)
 379    {
 380       return false;
 381    }
 382    SHA1Summation SHA1;
 383    if (Fd->Seek(0) == false || SHA1.AddFD(Fd->Fd(),CurStat.FileSize) == false)
 384       return false;
 385
 386    SHA1Res = SHA1.Result();
 387    hex2bytes(CurStat.SHA1, SHA1Res.data(), sizeof(CurStat.SHA1));
 388    CurStat.Flags |= FlSHA1;
 389    return true;
 390 }
 391                                                                         /*}}}*/
 392 // CacheDB::GetSHA256 - Get the SHA256 hash                             /*{{{*/
 393 // ---------------------------------------------------------------------
 394 /* */
 395 bool CacheDB::GetSHA256(bool GenOnly)
 396 {
 397    // Try to read the control information out of the DB.
 398    if ((CurStat.Flags & FlSHA256) == FlSHA256)
 399    {
 400       if (GenOnly == true)
 401          return true;
 402
 403       SHA256Res = bytes2hex(CurStat.SHA256, sizeof(CurStat.SHA256));
 404       return true;
 405    }
 406
 407    Stats.SHA256Bytes += CurStat.FileSize;
 408
 409    if (Fd == NULL && OpenFile() == false)
 410    {
 411       return false;
 412    }
 413    SHA256Summation SHA256;
 414    if (Fd->Seek(0) == false || SHA256.AddFD(Fd->Fd(),CurStat.FileSize) == false)
 415       return false;
 416
 417    SHA256Res = SHA256.Result();
 418    hex2bytes(CurStat.SHA256, SHA256Res.data(), sizeof(CurStat.SHA256));
 419    CurStat.Flags |= FlSHA256;
 420    return true;
 421 }
 422                                                                         /*}}}*/
 423 // CacheDB::Finish - Write back the cache structure                     /*{{{*/
 424 // ---------------------------------------------------------------------
 425 /* */
 426 bool CacheDB::Finish()
 427 {
 428    // Optimize away some writes.
 429    if (CurStat.Flags == OldStat.Flags &&
 430        CurStat.mtime == OldStat.mtime)
 431       return true;
 432
 433    // Write the stat information
 434    CurStat.Flags = htonl(CurStat.Flags);
 435    CurStat.FileSize = htonl(CurStat.FileSize);
 436    InitQuery("st");
 437    Put(&CurStat,sizeof(CurStat));
 438    CurStat.Flags = ntohl(CurStat.Flags);
 439    CurStat.FileSize = ntohl(CurStat.FileSize);
 440
 441    return true;
 442 }
 443                                                                         /*}}}*/
 444 // CacheDB::Clean - Clean the Database                                  /*{{{*/
 445 // ---------------------------------------------------------------------
 446 /* Tidy the database by removing files that no longer exist at all. */
 447 bool CacheDB::Clean()
 448 {
 449    if (DBLoaded == false)
 450       return true;
 451
 452    /* I'm not sure what VERSION_MINOR should be here.. 2.4.14 certainly
 453       needs the lower one and 2.7.7 needs the upper.. */
 454    DBC *Cursor;
 455    if ((errno = Dbp->cursor(Dbp, NULL, &Cursor, 0)) != 0)
 456       return _error->Error(_("Unable to get a cursor"));
 457
 458    DBT Key;
 459    DBT Data;
 460    memset(&Key,0,sizeof(Key));
 461    memset(&Data,0,sizeof(Data));
 462    while ((errno = Cursor->c_get(Cursor,&Key,&Data,DB_NEXT)) == 0)
 463    {
 464       const char *Colon = (char*)memrchr(Key.data, ':', Key.size);
 465       if (Colon)
 466       {
 467          if (stringcmp(Colon + 1, (char *)Key.data+Key.size,"st") == 0 ||
 468              stringcmp(Colon + 1, (char *)Key.data+Key.size,"cl") == 0 ||
 469              stringcmp(Colon + 1, (char *)Key.data+Key.size,"cn") == 0)
 470          {
 471             if (FileExists(string((const char *)Key.data,Colon)) == true)
 472                 continue;
 473          }
 474       }
 475
 476       Cursor->c_del(Cursor,0);
 477    }
 478
 479    return true;
 480 }
 481                                                                         /*}}}*/