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