nss/makedb.c

   1 /* Create simple DB database from textual input.
   2    Copyright (C) 1996-2012 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <argp.h>
  21 #include <assert.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24 #include <error.h>
  25 #include <fcntl.h>
  26 #include <inttypes.h>
  27 #include <libintl.h>
  28 #include <locale.h>
  29 #include <search.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34 #include <sys/mman.h>
  35 #include <sys/param.h>
  36 #include <sys/stat.h>
  37 #include <sys/uio.h>
  38 #include "nss_db/nss_db.h"
  39
  40 /* Get libc version number.  */
  41 #include "../version.h"
  42
  43 /* The hashing function we use.  */
  44 #include "../intl/hash-string.h"
  45
  46 /* SELinux support.  */
  47 #ifdef HAVE_SELINUX
  48 # include <selinux/selinux.h>
  49 #endif
  50
  51 #ifndef MAP_POPULATE
  52 # define MAP_POPULATE 0
  53 #endif
  54
  55 #define PACKAGE _libc_intl_domainname
  56
  57 /* List of data bases.  */
  58 struct database
  59 {
  60   char dbid;
  61   bool extra_string;
  62   struct database *next;
  63   void *entries;
  64   size_t nentries;
  65   size_t nhashentries;
  66   stridx_t *hashtable;
  67   size_t keystrlen;
  68   stridx_t *keyidxtab;
  69   char *keystrtab;
  70 } *databases;
  71 static size_t ndatabases;
  72 static size_t nhashentries_total;
  73 static size_t valstrlen;
  74 static void *valstrtree;
  75 static char *valstrtab;
  76 static size_t extrastrlen;
  77
  78 /* Database entry.  */
  79 struct dbentry
  80 {
  81   stridx_t validx;
  82   uint32_t hashval;
  83   char str[0];
  84 };
  85
  86 /* Stored string entry.  */
  87 struct valstrentry
  88 {
  89   stridx_t idx;
  90   bool extra_string;
  91   char str[0];
  92 };
  93
  94
  95 /* True if any entry has been added.  */
  96 static bool any_dbentry;
  97
  98 /* If non-zero convert key to lower case.  */
  99 static int to_lowercase;
 100
 101 /* If non-zero print content of input file, one entry per line.  */
 102 static int do_undo;
 103
 104 /* If non-zero do not print informational messages.  */
 105 static int be_quiet;
 106
 107 /* Name of output file.  */
 108 static const char *output_name;
 109
 110 /* Name and version of program.  */
 111 static void print_version (FILE *stream, struct argp_state *state);
 112 void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
 113
 114 /* Definitions of arguments for argp functions.  */
 115 static const struct argp_option options[] =
 116 {
 117   { "fold-case", 'f', NULL, 0, N_("Convert key to lower case") },
 118   { "output", 'o', N_("NAME"), 0, N_("Write output to file NAME") },
 119   { "quiet", 'q', NULL, 0,
 120     N_("Do not print messages while building database") },
 121   { "undo", 'u', NULL, 0,
 122     N_("Print content of database file, one entry a line") },
 123   { "generated", 'g', N_("CHAR"), 0,
 124     N_("Generated line not part of iteration") },
 125   { NULL, 0, NULL, 0, NULL }
 126 };
 127
 128 /* Short description of program.  */
 129 static const char doc[] = N_("Create simple database from textual input.");
 130
 131 /* Strings for arguments in help texts.  */
 132 static const char args_doc[] = N_("\
 133 INPUT-FILE OUTPUT-FILE\n-o OUTPUT-FILE INPUT-FILE\n-u INPUT-FILE");
 134
 135 /* Prototype for option handler.  */
 136 static error_t parse_opt (int key, char *arg, struct argp_state *state);
 137
 138 /* Function to print some extra text in the help message.  */
 139 static char *more_help (int key, const char *text, void *input);
 140
 141 /* Data structure to communicate with argp functions.  */
 142 static struct argp argp =
 143 {
 144   options, parse_opt, args_doc, doc, NULL, more_help
 145 };
 146
 147
 148 /* List of databases which are not part of the iteration table.  */
 149 static struct db_option
 150 {
 151   char dbid;
 152   struct db_option *next;
 153 } *db_options;
 154
 155
 156 /* Prototypes for local functions.  */
 157 static int process_input (FILE *input, const char *inname,
 158                           int to_lowercase, int be_quiet);
 159 static int print_database (int fd);
 160 static void compute_tables (void);
 161 static int write_output (int fd);
 162
 163 /* SELinux support.  */
 164 #ifdef HAVE_SELINUX
 165 /* Set the SELinux file creation context for the given file. */
 166 static void set_file_creation_context (const char *outname, mode_t mode);
 167 static void reset_file_creation_context (void);
 168 #else
 169 # define set_file_creation_context(_outname,_mode)
 170 # define reset_file_creation_context()
 171 #endif
 172
 173
 174 /* External functions.  */
 175 extern void *xmalloc (size_t n)
 176   __attribute_malloc__ __attribute_alloc_size (1);
 177 extern void *xcalloc (size_t n, size_t s)
 178   __attribute_malloc__ __attribute_alloc_size (1, 2);
 179
 180
 181 int
 182 main (int argc, char *argv[])
 183 {
 184   const char *input_name;
 185   FILE *input_file;
 186   int remaining;
 187   int mode = 0644;
 188
 189   /* Set locale via LC_ALL.  */
 190   setlocale (LC_ALL, "");
 191
 192   /* Set the text message domain.  */
 193   textdomain (_libc_intl_domainname);
 194
 195   /* Initialize local variables.  */
 196   input_name = NULL;
 197
 198   /* Parse and process arguments.  */
 199   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 200
 201   /* Determine file names.  */
 202   if (do_undo || output_name != NULL)
 203     {
 204       if (remaining + 1 != argc)
 205         {
 206         wrong_arguments:
 207           error (0, 0, gettext ("wrong number of arguments"));
 208           argp_help (&argp, stdout, ARGP_HELP_SEE,
 209                      program_invocation_short_name);
 210           exit (1);
 211         }
 212       input_name = argv[remaining];
 213     }
 214   else
 215     {
 216       if (remaining + 2 != argc)
 217         goto wrong_arguments;
 218
 219       input_name = argv[remaining++];
 220       output_name = argv[remaining];
 221     }
 222
 223   /* Special handling if we are asked to print the database.  */
 224   if (do_undo)
 225     {
 226       int fd = open (input_name, O_RDONLY);
 227       if (fd == -1)
 228         error (EXIT_FAILURE, errno, gettext ("cannot open database file `%s'"),
 229                input_name);
 230
 231       int status = print_database (fd);
 232
 233       close (fd);
 234
 235       return status;
 236     }
 237
 238   /* Open input file.  */
 239   if (strcmp (input_name, "-") == 0 || strcmp (input_name, "/dev/stdin") == 0)
 240     input_file = stdin;
 241   else
 242     {
 243       struct stat64 st;
 244
 245       input_file = fopen64 (input_name, "r");
 246       if (input_file == NULL)
 247         error (EXIT_FAILURE, errno, gettext ("cannot open input file `%s'"),
 248                input_name);
 249
 250       /* Get the access rights from the source file.  The output file should
 251          have the same.  */
 252       if (fstat64 (fileno (input_file), &st) >= 0)
 253         mode = st.st_mode & ACCESSPERMS;
 254     }
 255
 256   /* Start the real work.  */
 257   int status = process_input (input_file, input_name, to_lowercase, be_quiet);
 258
 259   /* Close files.  */
 260   if (input_file != stdin)
 261     fclose (input_file);
 262
 263   /* No need to continue when we did not read the file successfully.  */
 264   if (status != EXIT_SUCCESS)
 265     return status;
 266
 267   /* Bail out if nothing is to be done.  */
 268   if (!any_dbentry)
 269     {
 270       if (be_quiet)
 271         return EXIT_SUCCESS;
 272       else
 273         error (EXIT_SUCCESS, 0, gettext ("no entries to be processed"));
 274     }
 275
 276   /* Compute hash and string tables.  */
 277   compute_tables ();
 278
 279   /* Open output file.  This must not be standard output so we don't
 280      handle "-" and "/dev/stdout" special.  */
 281   char *tmp_output_name;
 282   if (asprintf (&tmp_output_name, "%s.XXXXXX", output_name) == -1)
 283     error (EXIT_FAILURE, errno, gettext ("cannot create temporary file name"));
 284
 285   set_file_creation_context (output_name, mode);
 286   int fd = mkstemp (tmp_output_name);
 287   reset_file_creation_context ();
 288   if (fd == -1)
 289     error (EXIT_FAILURE, errno, gettext ("cannot create temporary file"));
 290
 291   status = write_output (fd);
 292
 293   if (status == EXIT_SUCCESS)
 294     {
 295       struct stat64 st;
 296
 297       if (fstat64 (fd, &st) == 0)
 298         {
 299           if ((st.st_mode & ACCESSPERMS) != mode)
 300             /* We ignore problems with changing the mode.  */
 301             fchmod (fd, mode);
 302         }
 303       else
 304         {
 305           error (0, errno, gettext ("cannot stat newly created file"));
 306           status = EXIT_FAILURE;
 307         }
 308     }
 309
 310   close (fd);
 311
 312   if (status == EXIT_SUCCESS)
 313     {
 314       if (rename (tmp_output_name, output_name) != 0)
 315         {
 316           error (0, errno, gettext ("cannot rename temporary file"));
 317           status = EXIT_FAILURE;
 318           goto do_unlink;
 319         }
 320     }
 321   else
 322   do_unlink:
 323     unlink (tmp_output_name);
 324
 325   return status;
 326 }
 327
 328
 329 /* Handle program arguments.  */
 330 static error_t
 331 parse_opt (int key, char *arg, struct argp_state *state)
 332 {
 333   struct db_option *newp;
 334
 335   switch (key)
 336     {
 337     case 'f':
 338       to_lowercase = 1;
 339       break;
 340     case 'o':
 341       output_name = arg;
 342       break;
 343     case 'q':
 344       be_quiet = 1;
 345       break;
 346     case 'u':
 347       do_undo = 1;
 348       break;
 349     case 'g':
 350       newp = xmalloc (sizeof (*newp));
 351       newp->dbid = arg[0];
 352       newp->next = db_options;
 353       db_options = newp;
 354       break;
 355     default:
 356       return ARGP_ERR_UNKNOWN;
 357     }
 358   return 0;
 359 }
 360
 361
 362 static char *
 363 more_help (int key, const char *text, void *input)
 364 {
 365   switch (key)
 366     {
 367     case ARGP_KEY_HELP_EXTRA:
 368       /* We print some extra information.  */
 369       return strdup (gettext ("\
 370 For bug reporting instructions, please see:\n\
 371 <http://www.gnu.org/software/libc/bugs.html>.\n"));
 372     default:
 373       break;
 374     }
 375   return (char *) text;
 376 }
 377
 378 /* Print the version information.  */
 379 static void
 380 print_version (FILE *stream, struct argp_state *state)
 381 {
 382   fprintf (stream, "makedb (GNU %s) %s\n", PACKAGE, VERSION);
 383   fprintf (stream, gettext ("\
 384 Copyright (C) %s Free Software Foundation, Inc.\n\
 385 This is free software; see the source for copying conditions.  There is NO\n\
 386 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
 387 "), "2012");
 388   fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
 389 }
 390
 391
 392 static int
 393 dbentry_compare (const void *p1, const void *p2)
 394 {
 395   const struct dbentry *d1 = (const struct dbentry *) p1;
 396   const struct dbentry *d2 = (const struct dbentry *) p2;
 397
 398   if (d1->hashval != d2->hashval)
 399     return d1->hashval < d2->hashval ? -1 : 1;
 400
 401   return strcmp (d1->str, d2->str);
 402 }
 403
 404
 405 static int
 406 valstr_compare (const void *p1, const void *p2)
 407 {
 408   const struct valstrentry *d1 = (const struct valstrentry *) p1;
 409   const struct valstrentry *d2 = (const struct valstrentry *) p2;
 410
 411   return strcmp (d1->str, d2->str);
 412 }
 413
 414
 415 static int
 416 process_input (input, inname, to_lowercase, be_quiet)
 417      FILE *input;
 418      const char *inname;
 419      int to_lowercase;
 420      int be_quiet;
 421 {
 422   char *line;
 423   size_t linelen;
 424   int status;
 425   size_t linenr;
 426
 427   line = NULL;
 428   linelen = 0;
 429   status = EXIT_SUCCESS;
 430   linenr = 0;
 431
 432   struct database *last_database = NULL;
 433
 434   while (!feof_unlocked (input))
 435     {
 436       ssize_t n = getline (&line, &linelen, input);
 437       if (n < 0)
 438         /* This means end of file or some bug.  */
 439         break;
 440       if (n == 0)
 441         /* Short read.  Probably interrupted system call. */
 442         continue;
 443
 444       ++linenr;
 445
 446       if (line[n - 1] == '\n')
 447         /* Remove trailing newline.  */
 448         line[--n] = '\0';
 449
 450       char *cp = line;
 451       while (isspace (*cp))
 452         ++cp;
 453
 454       if (*cp == '#' || *cp == '\0')
 455         /* First non-space character in line '#': it's a comment.
 456            Also go to the next line if it is empty except for whitespaces. */
 457         continue;
 458
 459       /* Skip over the character indicating the database so that it is not
 460          affected by TO_LOWERCASE.  */
 461       char *key = cp++;
 462       while (*cp != '\0' && !isspace (*cp))
 463         {
 464           if (to_lowercase)
 465             *cp = tolower (*cp);
 466           ++cp;
 467         }
 468
 469       if (*cp == '\0')
 470         /* It's a line without a value field.  */
 471         continue;
 472
 473       *cp++ = '\0';
 474       size_t keylen = cp - key;
 475
 476       while (isspace (*cp))
 477         ++cp;
 478
 479       char *data = cp;
 480       size_t datalen = (&line[n] - cp) + 1;
 481
 482       /* Find the database.  */
 483       if (last_database == NULL || last_database->dbid != key[0])
 484         {
 485           last_database = databases;
 486           while (last_database != NULL && last_database->dbid != key[0])
 487             last_database = last_database->next;
 488
 489           if (last_database == NULL)
 490             {
 491               last_database = xmalloc (sizeof (*last_database));
 492               last_database->dbid = key[0];
 493               last_database->extra_string = false;
 494               last_database->next = databases;
 495               last_database->entries = NULL;
 496               last_database->nentries = 0;
 497               last_database->keystrlen = 0;
 498               databases = last_database;
 499
 500               struct db_option *runp = db_options;
 501               while (runp != NULL)
 502                 if (runp->dbid == key[0])
 503                   {
 504                     last_database->extra_string = true;
 505                     break;
 506                   }
 507                 else
 508                   runp = runp->next;
 509             }
 510         }
 511
 512       /* Skip the database selector.  */
 513       ++key;
 514       --keylen;
 515
 516       /* Store the data.  */
 517       struct valstrentry *nentry = xmalloc (sizeof (struct valstrentry)
 518                                             + datalen);
 519       if (last_database->extra_string)
 520         nentry->idx = extrastrlen;
 521       else
 522         nentry->idx = valstrlen;
 523       nentry->extra_string = last_database->extra_string;
 524       memcpy (nentry->str, data, datalen);
 525
 526       struct valstrentry **fdata = tsearch (nentry, &valstrtree,
 527                                             valstr_compare);
 528       if (fdata == NULL)
 529         error (EXIT_FAILURE, errno, gettext ("cannot create search tree"));
 530
 531       if (*fdata != nentry)
 532         {
 533           /* We can reuse a string.  */
 534           free (nentry);
 535           nentry = *fdata;
 536         }
 537       else
 538         if (last_database->extra_string)
 539           extrastrlen += datalen;
 540         else
 541           valstrlen += datalen;
 542
 543       /* Store the key.  */
 544       struct dbentry *newp = xmalloc (sizeof (struct dbentry) + keylen);
 545       newp->validx = nentry->idx;
 546       newp->hashval = __hash_string (key);
 547       memcpy (newp->str, key, keylen);
 548
 549       struct dbentry **found = tsearch (newp, &last_database->entries,
 550                                         dbentry_compare);
 551       if (found == NULL)
 552         error (EXIT_FAILURE, errno, gettext ("cannot create search tree"));
 553
 554       if (*found != newp)
 555         {
 556           free (newp);
 557           if (!be_quiet)
 558             error_at_line (0, 0, inname, linenr, gettext ("duplicate key"));
 559           continue;
 560         }
 561
 562       ++last_database->nentries;
 563       last_database->keystrlen += keylen;
 564
 565       any_dbentry = true;
 566     }
 567
 568   if (ferror_unlocked (input))
 569     {
 570       error (0, 0, gettext ("problems while reading `%s'"), inname);
 571       status = EXIT_FAILURE;
 572     }
 573
 574   return status;
 575 }
 576
 577
 578 static void
 579 copy_valstr (const void *nodep, const VISIT which, const int depth)
 580 {
 581   if (which != leaf && which != postorder)
 582     return;
 583
 584   const struct valstrentry *p = *(const struct valstrentry **) nodep;
 585
 586   strcpy (valstrtab + (p->extra_string ? valstrlen : 0) + p->idx, p->str);
 587 }
 588
 589
 590 static int
 591 is_prime (size_t candidate)
 592 {
 593   /* No even number and none less than 10 will be passed here.  */
 594   size_t divn = 3;
 595   size_t sq = divn * divn;
 596
 597   while (sq < candidate && candidate % divn != 0)
 598     {
 599       ++divn;
 600       sq += 4 * divn;
 601       ++divn;
 602     }
 603
 604   return candidate % divn != 0;
 605 }
 606
 607
 608 static size_t
 609 next_prime (size_t seed)
 610 {
 611   /* Make it definitely odd.  */
 612   seed |= 1;
 613
 614   while (!is_prime (seed))
 615     seed += 2;
 616
 617   return seed;
 618 }
 619
 620
 621 static void
 622 compute_tables (void)
 623 {
 624   valstrtab = xmalloc (roundup (valstrlen + extrastrlen, sizeof (stridx_t)));
 625   while ((valstrlen + extrastrlen) % sizeof (stridx_t) != 0)
 626     valstrtab[valstrlen++] = '\0';
 627   twalk (valstrtree, copy_valstr);
 628
 629   static struct database *db;
 630   for (db = databases; db != NULL; db = db->next)
 631     if (db->nentries != 0)
 632       {
 633         ++ndatabases;
 634
 635         /* We simply use an odd number large than twice the number of
 636            elements to store in the hash table for the size.  This gives
 637            enough efficiency.  */
 638 #define TEST_RANGE 30
 639         size_t nhashentries_min = next_prime (db->nentries < TEST_RANGE
 640                                               ? db->nentries
 641                                               : db->nentries * 2 - TEST_RANGE);
 642         size_t nhashentries_max = MAX (nhashentries_min, db->nentries * 4);
 643         size_t nhashentries_best = nhashentries_min;
 644         size_t chainlength_best = db->nentries;
 645
 646         db->hashtable = xmalloc (2 * nhashentries_max * sizeof (stridx_t)
 647                                  + db->keystrlen);
 648         db->keyidxtab = db->hashtable + nhashentries_max;
 649         db->keystrtab = (char *) (db->keyidxtab + nhashentries_max);
 650
 651         static size_t max_chainlength;
 652         static char *wp;
 653         static size_t nhashentries;
 654         static bool copy_string;
 655
 656         void add_key(const void *nodep, const VISIT which, const int depth)
 657         {
 658           if (which != leaf && which != postorder)
 659             return;
 660
 661           const struct dbentry *dbe = *(const struct dbentry **) nodep;
 662
 663           ptrdiff_t stridx;
 664           if (copy_string)
 665             {
 666               stridx = wp - db->keystrtab;
 667               wp = stpcpy (wp, dbe->str) + 1;
 668             }
 669           else
 670             stridx = 0;
 671
 672           size_t hidx = dbe->hashval % nhashentries;
 673           size_t hval2 = 1 + dbe->hashval % (nhashentries - 2);
 674           size_t chainlength = 0;
 675
 676           while (db->hashtable[hidx] != ~((stridx_t) 0))
 677             {
 678               ++chainlength;
 679               if ((hidx += hval2) >= nhashentries)
 680                 hidx -= nhashentries;
 681             }
 682
 683           db->hashtable[hidx] = ((db->extra_string ? valstrlen : 0)
 684                                  + dbe->validx);
 685           db->keyidxtab[hidx] = stridx;
 686
 687           max_chainlength = MAX (max_chainlength, chainlength);
 688         }
 689
 690         copy_string = false;
 691         nhashentries = nhashentries_min;
 692         for (size_t cnt = 0; cnt < TEST_RANGE; ++cnt)
 693           {
 694             memset (db->hashtable, '\xff', nhashentries * sizeof (stridx_t));
 695
 696             max_chainlength = 0;
 697             wp = db->keystrtab;
 698
 699             twalk (db->entries, add_key);
 700
 701             if (max_chainlength == 0)
 702               {
 703                 /* No need to look further, this is as good as it gets.  */
 704                 nhashentries_best = nhashentries;
 705                 break;
 706               }
 707
 708             if (max_chainlength < chainlength_best)
 709               {
 710                 chainlength_best = max_chainlength;
 711                 nhashentries_best = nhashentries;
 712               }
 713
 714             nhashentries = next_prime (nhashentries + 1);
 715             if (nhashentries > nhashentries_max)
 716               break;
 717           }
 718
 719         /* Recompute the best table again, this time fill in the strings.  */
 720         nhashentries = nhashentries_best;
 721         memset (db->hashtable, '\xff',
 722                 2 * nhashentries_max * sizeof (stridx_t));
 723         copy_string = true;
 724         wp = db->keystrtab;
 725
 726         twalk (db->entries, add_key);
 727
 728         db->nhashentries = nhashentries_best;
 729         nhashentries_total += nhashentries_best;
 730     }
 731 }
 732
 733
 734 static int
 735 write_output (int fd)
 736 {
 737   struct nss_db_header *header;
 738   uint64_t file_offset = (sizeof (struct nss_db_header)
 739                           + (ndatabases * sizeof (header->dbs[0])));
 740   header = alloca (file_offset);
 741
 742   header->magic = NSS_DB_MAGIC;
 743   header->ndbs = ndatabases;
 744   header->valstroffset = file_offset;
 745   header->valstrlen = valstrlen;
 746
 747   size_t filled_dbs = 0;
 748   struct iovec iov[2 + ndatabases * 3];
 749   iov[0].iov_base = header;
 750   iov[0].iov_len = file_offset;
 751
 752   iov[1].iov_base = valstrtab;
 753   iov[1].iov_len = valstrlen + extrastrlen;
 754   file_offset += iov[1].iov_len;
 755
 756   size_t keydataoffset = file_offset + nhashentries_total * sizeof (stridx_t);
 757   for (struct database *db = databases; db != NULL; db = db->next)
 758     if (db->entries != NULL)
 759       {
 760         assert (file_offset % sizeof (stridx_t) == 0);
 761         assert (filled_dbs < ndatabases);
 762
 763         header->dbs[filled_dbs].id = db->dbid;
 764         memset (header->dbs[filled_dbs].pad, '\0',
 765                 sizeof (header->dbs[0].pad));
 766         header->dbs[filled_dbs].hashsize = db->nhashentries;
 767
 768         iov[2 + filled_dbs].iov_base = db->hashtable;
 769         iov[2 + filled_dbs].iov_len = db->nhashentries * sizeof (stridx_t);
 770         header->dbs[filled_dbs].hashoffset = file_offset;
 771         file_offset += iov[2 + filled_dbs].iov_len;
 772
 773         iov[2 + ndatabases + filled_dbs * 2].iov_base = db->keyidxtab;
 774         iov[2 + ndatabases + filled_dbs * 2].iov_len
 775           = db->nhashentries * sizeof (stridx_t);
 776         header->dbs[filled_dbs].keyidxoffset = keydataoffset;
 777         keydataoffset += iov[2 + ndatabases + filled_dbs * 2].iov_len;
 778
 779         iov[3 + ndatabases + filled_dbs * 2].iov_base = db->keystrtab;
 780         iov[3 + ndatabases + filled_dbs * 2].iov_len = db->keystrlen;
 781         header->dbs[filled_dbs].keystroffset = keydataoffset;
 782         keydataoffset += iov[3 + ndatabases + filled_dbs * 2].iov_len;
 783
 784         ++filled_dbs;
 785       }
 786
 787   assert (filled_dbs == ndatabases);
 788   assert (file_offset == (iov[0].iov_len + iov[1].iov_len
 789                           + nhashentries_total * sizeof (stridx_t)));
 790   header->allocate = file_offset;
 791
 792   if (writev (fd, iov, 2 + ndatabases * 3) != keydataoffset)
 793     {
 794       error (0, errno, gettext ("failed to write new database file"));
 795       return EXIT_FAILURE;
 796     }
 797
 798   return EXIT_SUCCESS;
 799 }
 800
 801
 802 static int
 803 print_database (int fd)
 804 {
 805   struct stat64 st;
 806   if (fstat64 (fd, &st) != 0)
 807     error (EXIT_FAILURE, errno, gettext ("cannot stat database file"));
 808
 809   const struct nss_db_header *header = mmap (NULL, st.st_size, PROT_READ,
 810                                              MAP_PRIVATE|MAP_POPULATE, fd, 0);
 811   if (header == MAP_FAILED)
 812     error (EXIT_FAILURE, errno, gettext ("cannot map database file"));
 813
 814   if (header->magic != NSS_DB_MAGIC)
 815     error (EXIT_FAILURE, 0, gettext ("file not a database file"));
 816
 817   const char *valstrtab = (const char *) header + header->valstroffset;
 818
 819   for (unsigned int dbidx = 0; dbidx < header->ndbs; ++dbidx)
 820     {
 821       const stridx_t *stridxtab
 822         = ((const stridx_t *) ((const char *) header
 823                                + header->dbs[dbidx].keyidxoffset));
 824       const char *keystrtab
 825         = (const char *) header + header->dbs[dbidx].keystroffset;
 826       const stridx_t *hashtab
 827         = (const stridx_t *) ((const char *) header
 828                               + header->dbs[dbidx].hashoffset);
 829
 830       for (uint32_t hidx = 0; hidx < header->dbs[dbidx].hashsize; ++hidx)
 831         if (hashtab[hidx] != ~((stridx_t) 0))
 832           printf ("%c%s %s\n",
 833                   header->dbs[dbidx].id,
 834                   keystrtab + stridxtab[hidx],
 835                   valstrtab + hashtab[hidx]);
 836     }
 837
 838   return EXIT_SUCCESS;
 839 }
 840
 841
 842 #ifdef HAVE_SELINUX
 843 static void
 844 set_file_creation_context (const char *outname, mode_t mode)
 845 {
 846   static int enabled;
 847   static int enforcing;
 848   security_context_t ctx;
 849
 850   /* Check if SELinux is enabled, and remember. */
 851   if (enabled == 0)
 852     enabled = is_selinux_enabled () ? 1 : -1;
 853   if (enabled < 0)
 854     return;
 855
 856   /* Check if SELinux is enforcing, and remember. */
 857   if (enforcing == 0)
 858     enforcing = security_getenforce () ? 1 : -1;
 859
 860   /* Determine the context which the file should have. */
 861   ctx = NULL;
 862   if (matchpathcon (outname, S_IFREG | mode, &ctx) == 0 && ctx != NULL)
 863     {
 864       if (setfscreatecon (ctx) != 0)
 865         error (enforcing > 0 ? EXIT_FAILURE : 0, 0,
 866                gettext ("cannot set file creation context for `%s'"),
 867                outname);
 868
 869       freecon (ctx);
 870     }
 871 }
 872
 873 static void
 874 reset_file_creation_context (void)
 875 {
 876   setfscreatecon (NULL);
 877 }
 878 #endif