source3/lib/util_tdb.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    tdb utility functions
   4    Copyright (C) Andrew Tridgell   1992-1998
   5    Copyright (C) Rafal Szczesniak  2002
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #undef malloc
  23 #undef realloc
  24 #undef calloc
  25 #undef strdup
  26
  27 /* these are little tdb utility functions that are meant to make
  28    dealing with a tdb database a little less cumbersome in Samba */
  29
  30 static SIG_ATOMIC_T gotalarm;
  31
  32 /***************************************************************
  33  Signal function to tell us we timed out.
  34 ****************************************************************/
  35
  36 static void gotalarm_sig(void)
  37 {
  38         gotalarm = 1;
  39 }
  40
  41 /***************************************************************
  42  Make a TDB_DATA and keep the const warning in one place
  43 ****************************************************************/
  44
  45 TDB_DATA make_tdb_data(const uint8 *dptr, size_t dsize)
  46 {
  47         TDB_DATA ret;
  48         ret.dptr = CONST_DISCARD(uint8 *, dptr);
  49         ret.dsize = dsize;
  50         return ret;
  51 }
  52
  53 TDB_DATA string_tdb_data(const char *string)
  54 {
  55         return make_tdb_data((const uint8 *)string, string ? strlen(string) : 0 );
  56 }
  57
  58 TDB_DATA string_term_tdb_data(const char *string)
  59 {
  60         return make_tdb_data((const uint8 *)string, string ? strlen(string) + 1 : 0);
  61 }
  62
  63 /****************************************************************************
  64  Lock a chain with timeout (in seconds).
  65 ****************************************************************************/
  66
  67 static int tdb_chainlock_with_timeout_internal( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout, int rw_type)
  68 {
  69         /* Allow tdb_chainlock to be interrupted by an alarm. */
  70         int ret;
  71         gotalarm = 0;
  72
  73         if (timeout) {
  74                 CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
  75                 tdb_setalarm_sigptr(tdb, &gotalarm);
  76                 alarm(timeout);
  77         }
  78
  79         if (rw_type == F_RDLCK)
  80                 ret = tdb_chainlock_read(tdb, key);
  81         else
  82                 ret = tdb_chainlock(tdb, key);
  83
  84         if (timeout) {
  85                 alarm(0);
  86                 tdb_setalarm_sigptr(tdb, NULL);
  87                 CatchSignal(SIGALRM, SIGNAL_CAST SIG_IGN);
  88                 if (gotalarm) {
  89                         DEBUG(0,("tdb_chainlock_with_timeout_internal: alarm (%u) timed out for key %s in tdb %s\n",
  90                                 timeout, key.dptr, tdb_name(tdb)));
  91                         /* TODO: If we time out waiting for a lock, it might
  92                          * be nice to use F_GETLK to get the pid of the
  93                          * process currently holding the lock and print that
  94                          * as part of the debugging message. -- mbp */
  95                         return -1;
  96                 }
  97         }
  98
  99         return ret;
 100 }
 101
 102 /****************************************************************************
 103  Write lock a chain. Return -1 if timeout or lock failed.
 104 ****************************************************************************/
 105
 106 int tdb_chainlock_with_timeout( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout)
 107 {
 108         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_WRLCK);
 109 }
 110
 111 /****************************************************************************
 112  Lock a chain by string. Return -1 if timeout or lock failed.
 113 ****************************************************************************/
 114
 115 int tdb_lock_bystring(TDB_CONTEXT *tdb, const char *keyval)
 116 {
 117         TDB_DATA key = string_term_tdb_data(keyval);
 118
 119         return tdb_chainlock(tdb, key);
 120 }
 121
 122 int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval,
 123                                    int timeout)
 124 {
 125         TDB_DATA key = string_term_tdb_data(keyval);
 126
 127         return tdb_chainlock_with_timeout(tdb, key, timeout);
 128 }
 129
 130 /****************************************************************************
 131  Unlock a chain by string.
 132 ****************************************************************************/
 133
 134 void tdb_unlock_bystring(TDB_CONTEXT *tdb, const char *keyval)
 135 {
 136         TDB_DATA key = string_term_tdb_data(keyval);
 137
 138         tdb_chainunlock(tdb, key);
 139 }
 140
 141 /****************************************************************************
 142  Read lock a chain by string. Return -1 if timeout or lock failed.
 143 ****************************************************************************/
 144
 145 int tdb_read_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, unsigned int timeout)
 146 {
 147         TDB_DATA key = string_term_tdb_data(keyval);
 148
 149         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_RDLCK);
 150 }
 151
 152 /****************************************************************************
 153  Read unlock a chain by string.
 154 ****************************************************************************/
 155
 156 void tdb_read_unlock_bystring(TDB_CONTEXT *tdb, const char *keyval)
 157 {
 158         TDB_DATA key = string_term_tdb_data(keyval);
 159
 160         tdb_chainunlock_read(tdb, key);
 161 }
 162
 163
 164 /****************************************************************************
 165  Fetch a int32 value by a arbitrary blob key, return -1 if not found.
 166  Output is int32 in native byte order.
 167 ****************************************************************************/
 168
 169 static int32 tdb_fetch_int32_byblob(TDB_CONTEXT *tdb, TDB_DATA key)
 170 {
 171         TDB_DATA data;
 172         int32 ret;
 173
 174         data = tdb_fetch(tdb, key);
 175         if (!data.dptr || data.dsize != sizeof(int32)) {
 176                 SAFE_FREE(data.dptr);
 177                 return -1;
 178         }
 179
 180         ret = IVAL(data.dptr,0);
 181         SAFE_FREE(data.dptr);
 182         return ret;
 183 }
 184
 185 /****************************************************************************
 186  Fetch a int32 value by string key, return -1 if not found.
 187  Output is int32 in native byte order.
 188 ****************************************************************************/
 189
 190 int32 tdb_fetch_int32(TDB_CONTEXT *tdb, const char *keystr)
 191 {
 192         TDB_DATA key = string_term_tdb_data(keystr);
 193
 194         return tdb_fetch_int32_byblob(tdb, key);
 195 }
 196
 197 /****************************************************************************
 198  Store a int32 value by an arbitary blob key, return 0 on success, -1 on failure.
 199  Input is int32 in native byte order. Output in tdb is in little-endian.
 200 ****************************************************************************/
 201
 202 static int tdb_store_int32_byblob(TDB_CONTEXT *tdb, TDB_DATA key, int32 v)
 203 {
 204         TDB_DATA data;
 205         int32 v_store;
 206
 207         SIVAL(&v_store,0,v);
 208         data.dptr = (uint8 *)&v_store;
 209         data.dsize = sizeof(int32);
 210
 211         return tdb_store(tdb, key, data, TDB_REPLACE);
 212 }
 213
 214 /****************************************************************************
 215  Store a int32 value by string key, return 0 on success, -1 on failure.
 216  Input is int32 in native byte order. Output in tdb is in little-endian.
 217 ****************************************************************************/
 218
 219 int tdb_store_int32(TDB_CONTEXT *tdb, const char *keystr, int32 v)
 220 {
 221         TDB_DATA key = string_term_tdb_data(keystr);
 222
 223         return tdb_store_int32_byblob(tdb, key, v);
 224 }
 225
 226 /****************************************************************************
 227  Fetch a uint32 value by a arbitrary blob key, return -1 if not found.
 228  Output is uint32 in native byte order.
 229 ****************************************************************************/
 230
 231 static bool tdb_fetch_uint32_byblob(TDB_CONTEXT *tdb, TDB_DATA key, uint32 *value)
 232 {
 233         TDB_DATA data;
 234
 235         data = tdb_fetch(tdb, key);
 236         if (!data.dptr || data.dsize != sizeof(uint32)) {
 237                 SAFE_FREE(data.dptr);
 238                 return False;
 239         }
 240
 241         *value = IVAL(data.dptr,0);
 242         SAFE_FREE(data.dptr);
 243         return True;
 244 }
 245
 246 /****************************************************************************
 247  Fetch a uint32 value by string key, return -1 if not found.
 248  Output is uint32 in native byte order.
 249 ****************************************************************************/
 250
 251 bool tdb_fetch_uint32(TDB_CONTEXT *tdb, const char *keystr, uint32 *value)
 252 {
 253         TDB_DATA key = string_term_tdb_data(keystr);
 254
 255         return tdb_fetch_uint32_byblob(tdb, key, value);
 256 }
 257
 258 /****************************************************************************
 259  Store a uint32 value by an arbitary blob key, return 0 on success, -1 on failure.
 260  Input is uint32 in native byte order. Output in tdb is in little-endian.
 261 ****************************************************************************/
 262
 263 static bool tdb_store_uint32_byblob(TDB_CONTEXT *tdb, TDB_DATA key, uint32 value)
 264 {
 265         TDB_DATA data;
 266         uint32 v_store;
 267         bool ret = True;
 268
 269         SIVAL(&v_store, 0, value);
 270         data.dptr = (uint8 *)&v_store;
 271         data.dsize = sizeof(uint32);
 272
 273         if (tdb_store(tdb, key, data, TDB_REPLACE) == -1)
 274                 ret = False;
 275
 276         return ret;
 277 }
 278
 279 /****************************************************************************
 280  Store a uint32 value by string key, return 0 on success, -1 on failure.
 281  Input is uint32 in native byte order. Output in tdb is in little-endian.
 282 ****************************************************************************/
 283
 284 bool tdb_store_uint32(TDB_CONTEXT *tdb, const char *keystr, uint32 value)
 285 {
 286         TDB_DATA key = string_term_tdb_data(keystr);
 287
 288         return tdb_store_uint32_byblob(tdb, key, value);
 289 }
 290 /****************************************************************************
 291  Store a buffer by a null terminated string key.  Return 0 on success, -1
 292  on failure.
 293 ****************************************************************************/
 294
 295 int tdb_store_bystring(TDB_CONTEXT *tdb, const char *keystr, TDB_DATA data, int flags)
 296 {
 297         TDB_DATA key = string_term_tdb_data(keystr);
 298
 299         return tdb_store(tdb, key, data, flags);
 300 }
 301
 302 int tdb_trans_store_bystring(TDB_CONTEXT *tdb, const char *keystr,
 303                              TDB_DATA data, int flags)
 304 {
 305         TDB_DATA key = string_term_tdb_data(keystr);
 306
 307         return tdb_trans_store(tdb, key, data, flags);
 308 }
 309
 310 /****************************************************************************
 311  Fetch a buffer using a null terminated string key.  Don't forget to call
 312  free() on the result dptr.
 313 ****************************************************************************/
 314
 315 TDB_DATA tdb_fetch_bystring(TDB_CONTEXT *tdb, const char *keystr)
 316 {
 317         TDB_DATA key = string_term_tdb_data(keystr);
 318
 319         return tdb_fetch(tdb, key);
 320 }
 321
 322 /****************************************************************************
 323  Delete an entry using a null terminated string key.
 324 ****************************************************************************/
 325
 326 int tdb_delete_bystring(TDB_CONTEXT *tdb, const char *keystr)
 327 {
 328         TDB_DATA key = string_term_tdb_data(keystr);
 329
 330         return tdb_delete(tdb, key);
 331 }
 332
 333 /****************************************************************************
 334  Atomic integer change. Returns old value. To create, set initial value in *oldval.
 335 ****************************************************************************/
 336
 337 int32 tdb_change_int32_atomic(TDB_CONTEXT *tdb, const char *keystr, int32 *oldval, int32 change_val)
 338 {
 339         int32 val;
 340         int32 ret = -1;
 341
 342         if (tdb_lock_bystring(tdb, keystr) == -1)
 343                 return -1;
 344
 345         if ((val = tdb_fetch_int32(tdb, keystr)) == -1) {
 346                 /* The lookup failed */
 347                 if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
 348                         /* but not because it didn't exist */
 349                         goto err_out;
 350                 }
 351
 352                 /* Start with 'old' value */
 353                 val = *oldval;
 354
 355         } else {
 356                 /* It worked, set return value (oldval) to tdb data */
 357                 *oldval = val;
 358         }
 359
 360         /* Increment value for storage and return next time */
 361         val += change_val;
 362
 363         if (tdb_store_int32(tdb, keystr, val) == -1)
 364                 goto err_out;
 365
 366         ret = 0;
 367
 368   err_out:
 369
 370         tdb_unlock_bystring(tdb, keystr);
 371         return ret;
 372 }
 373
 374 /****************************************************************************
 375  Atomic unsigned integer change. Returns old value. To create, set initial value in *oldval.
 376 ****************************************************************************/
 377
 378 bool tdb_change_uint32_atomic(TDB_CONTEXT *tdb, const char *keystr, uint32 *oldval, uint32 change_val)
 379 {
 380         uint32 val;
 381         bool ret = False;
 382
 383         if (tdb_lock_bystring(tdb, keystr) == -1)
 384                 return False;
 385
 386         if (!tdb_fetch_uint32(tdb, keystr, &val)) {
 387                 /* It failed */
 388                 if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
 389                         /* and not because it didn't exist */
 390                         goto err_out;
 391                 }
 392
 393                 /* Start with 'old' value */
 394                 val = *oldval;
 395
 396         } else {
 397                 /* it worked, set return value (oldval) to tdb data */
 398                 *oldval = val;
 399
 400         }
 401
 402         /* get a new value to store */
 403         val += change_val;
 404
 405         if (!tdb_store_uint32(tdb, keystr, val))
 406                 goto err_out;
 407
 408         ret = True;
 409
 410   err_out:
 411
 412         tdb_unlock_bystring(tdb, keystr);
 413         return ret;
 414 }
 415
 416 /****************************************************************************
 417  Useful pair of routines for packing/unpacking data consisting of
 418  integers and strings.
 419 ****************************************************************************/
 420
 421 static size_t tdb_pack_va(uint8 *buf, int bufsize, const char *fmt, va_list ap)
 422 {
 423         uint8 bt;
 424         uint16 w;
 425         uint32 d;
 426         int i;
 427         void *p;
 428         int len;
 429         char *s;
 430         char c;
 431         uint8 *buf0 = buf;
 432         const char *fmt0 = fmt;
 433         int bufsize0 = bufsize;
 434
 435         while (*fmt) {
 436                 switch ((c = *fmt++)) {
 437                 case 'b': /* unsigned 8-bit integer */
 438                         len = 1;
 439                         bt = (uint8)va_arg(ap, int);
 440                         if (bufsize && bufsize >= len)
 441                                 SSVAL(buf, 0, bt);
 442                         break;
 443                 case 'w': /* unsigned 16-bit integer */
 444                         len = 2;
 445                         w = (uint16)va_arg(ap, int);
 446                         if (bufsize && bufsize >= len)
 447                                 SSVAL(buf, 0, w);
 448                         break;
 449                 case 'd': /* signed 32-bit integer (standard int in most systems) */
 450                         len = 4;
 451                         d = va_arg(ap, uint32);
 452                         if (bufsize && bufsize >= len)
 453                                 SIVAL(buf, 0, d);
 454                         break;
 455                 case 'p': /* pointer */
 456                         len = 4;
 457                         p = va_arg(ap, void *);
 458                         d = p?1:0;
 459                         if (bufsize && bufsize >= len)
 460                                 SIVAL(buf, 0, d);
 461                         break;
 462                 case 'P': /* null-terminated string */
 463                         s = va_arg(ap,char *);
 464                         w = strlen(s);
 465                         len = w + 1;
 466                         if (bufsize && bufsize >= len)
 467                                 memcpy(buf, s, len);
 468                         break;
 469                 case 'f': /* null-terminated string */
 470                         s = va_arg(ap,char *);
 471                         w = strlen(s);
 472                         len = w + 1;
 473                         if (bufsize && bufsize >= len)
 474                                 memcpy(buf, s, len);
 475                         break;
 476                 case 'B': /* fixed-length string */
 477                         i = va_arg(ap, int);
 478                         s = va_arg(ap, char *);
 479                         len = 4+i;
 480                         if (bufsize && bufsize >= len) {
 481                                 SIVAL(buf, 0, i);
 482                                 memcpy(buf+4, s, i);
 483                         }
 484                         break;
 485                 default:
 486                         DEBUG(0,("Unknown tdb_pack format %c in %s\n",
 487                                  c, fmt));
 488                         len = 0;
 489                         break;
 490                 }
 491
 492                 buf += len;
 493                 if (bufsize)
 494                         bufsize -= len;
 495                 if (bufsize < 0)
 496                         bufsize = 0;
 497         }
 498
 499         DEBUG(18,("tdb_pack_va(%s, %d) -> %d\n",
 500                  fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
 501
 502         return PTR_DIFF(buf, buf0);
 503 }
 504
 505 size_t tdb_pack(uint8 *buf, int bufsize, const char *fmt, ...)
 506 {
 507         va_list ap;
 508         size_t result;
 509
 510         va_start(ap, fmt);
 511         result = tdb_pack_va(buf, bufsize, fmt, ap);
 512         va_end(ap);
 513         return result;
 514 }
 515
 516 bool tdb_pack_append(TALLOC_CTX *mem_ctx, uint8 **buf, size_t *len,
 517                      const char *fmt, ...)
 518 {
 519         va_list ap;
 520         size_t len1, len2;
 521
 522         va_start(ap, fmt);
 523         len1 = tdb_pack_va(NULL, 0, fmt, ap);
 524         va_end(ap);
 525
 526         if (mem_ctx != NULL) {
 527                 *buf = TALLOC_REALLOC_ARRAY(mem_ctx, *buf, uint8,
 528                                             (*len) + len1);
 529         } else {
 530                 *buf = SMB_REALLOC_ARRAY(*buf, uint8, (*len) + len1);
 531         }
 532
 533         if (*buf == NULL) {
 534                 return False;
 535         }
 536
 537         va_start(ap, fmt);
 538         len2 = tdb_pack_va((*buf)+(*len), len1, fmt, ap);
 539         va_end(ap);
 540
 541         if (len1 != len2) {
 542                 return False;
 543         }
 544
 545         *len += len2;
 546
 547         return True;
 548 }
 549
 550 /****************************************************************************
 551  Useful pair of routines for packing/unpacking data consisting of
 552  integers and strings.
 553 ****************************************************************************/
 554
 555 int tdb_unpack(const uint8 *buf, int bufsize, const char *fmt, ...)
 556 {
 557         va_list ap;
 558         uint8 *bt;
 559         uint16 *w;
 560         uint32 *d;
 561         int len;
 562         int *i;
 563         void **p;
 564         char *s, **b, **ps;
 565         char c;
 566         const uint8 *buf0 = buf;
 567         const char *fmt0 = fmt;
 568         int bufsize0 = bufsize;
 569
 570         va_start(ap, fmt);
 571
 572         while (*fmt) {
 573                 switch ((c=*fmt++)) {
 574                 case 'b':
 575                         len = 1;
 576                         bt = va_arg(ap, uint8 *);
 577                         if (bufsize < len)
 578                                 goto no_space;
 579                         *bt = SVAL(buf, 0);
 580                         break;
 581                 case 'w':
 582                         len = 2;
 583                         w = va_arg(ap, uint16 *);
 584                         if (bufsize < len)
 585                                 goto no_space;
 586                         *w = SVAL(buf, 0);
 587                         break;
 588                 case 'd':
 589                         len = 4;
 590                         d = va_arg(ap, uint32 *);
 591                         if (bufsize < len)
 592                                 goto no_space;
 593                         *d = IVAL(buf, 0);
 594                         break;
 595                 case 'p':
 596                         len = 4;
 597                         p = va_arg(ap, void **);
 598                         if (bufsize < len)
 599                                 goto no_space;
 600                         /*
 601                          * This isn't a real pointer - only a token (1 or 0)
 602                          * to mark the fact a pointer is present.
 603                          */
 604
 605                         *p = (void *)(IVAL(buf, 0) ? (void *)1 : NULL);
 606                         break;
 607                 case 'P':
 608                         /* Return malloc'ed string. */
 609                         ps = va_arg(ap,char **);
 610                         len = strlen((const char *)buf) + 1;
 611                         *ps = SMB_STRDUP((const char *)buf);
 612                         break;
 613                 case 'f':
 614                         s = va_arg(ap,char *);
 615                         len = strlen((const char *)buf) + 1;
 616                         if (bufsize < len || len > sizeof(fstring))
 617                                 goto no_space;
 618                         memcpy(s, buf, len);
 619                         break;
 620                 case 'B':
 621                         i = va_arg(ap, int *);
 622                         b = va_arg(ap, char **);
 623                         len = 4;
 624                         if (bufsize < len)
 625                                 goto no_space;
 626                         *i = IVAL(buf, 0);
 627                         if (! *i) {
 628                                 *b = NULL;
 629                                 break;
 630                         }
 631                         len += *i;
 632                         if (bufsize < len)
 633                                 goto no_space;
 634                         *b = (char *)SMB_MALLOC(*i);
 635                         if (! *b)
 636                                 goto no_space;
 637                         memcpy(*b, buf+4, *i);
 638                         break;
 639                 default:
 640                         DEBUG(0,("Unknown tdb_unpack format %c in %s\n",
 641                                  c, fmt));
 642
 643                         len = 0;
 644                         break;
 645                 }
 646
 647                 buf += len;
 648                 bufsize -= len;
 649         }
 650
 651         va_end(ap);
 652
 653         DEBUG(18,("tdb_unpack(%s, %d) -> %d\n",
 654                  fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
 655
 656         return PTR_DIFF(buf, buf0);
 657
 658  no_space:
 659         va_end(ap);
 660         return -1;
 661 }
 662
 663
 664 /****************************************************************************
 665  Log tdb messages via DEBUG().
 666 ****************************************************************************/
 667
 668 static void tdb_log(TDB_CONTEXT *tdb, enum tdb_debug_level level, const char *format, ...)
 669 {
 670         va_list ap;
 671         char *ptr = NULL;
 672         int ret;
 673
 674         va_start(ap, format);
 675         ret = vasprintf(&ptr, format, ap);
 676         va_end(ap);
 677
 678         if ((ret == -1) || !*ptr)
 679                 return;
 680
 681         DEBUG((int)level, ("tdb(%s): %s", tdb_name(tdb) ? tdb_name(tdb) : "unnamed", ptr));
 682         SAFE_FREE(ptr);
 683 }
 684
 685 /****************************************************************************
 686  Like tdb_open() but also setup a logging function that redirects to
 687  the samba DEBUG() system.
 688 ****************************************************************************/
 689
 690 TDB_CONTEXT *tdb_open_log(const char *name, int hash_size, int tdb_flags,
 691                           int open_flags, mode_t mode)
 692 {
 693         TDB_CONTEXT *tdb;
 694         struct tdb_logging_context log_ctx;
 695
 696         if (!lp_use_mmap())
 697                 tdb_flags |= TDB_NOMMAP;
 698
 699         log_ctx.log_fn = tdb_log;
 700         log_ctx.log_private = NULL;
 701
 702         if ((hash_size == 0) && (name != NULL)) {
 703                 const char *base = strrchr_m(name, '/');
 704                 if (base != NULL) {
 705                         base += 1;
 706                 }
 707                 else {
 708                         base = name;
 709                 }
 710                 hash_size = lp_parm_int(-1, "tdb_hashsize", base, 0);
 711         }
 712
 713         tdb = tdb_open_ex(name, hash_size, tdb_flags,
 714                           open_flags, mode, &log_ctx, NULL);
 715         if (!tdb)
 716                 return NULL;
 717
 718         return tdb;
 719 }
 720
 721 /****************************************************************************
 722  Allow tdb_delete to be used as a tdb_traversal_fn.
 723 ****************************************************************************/
 724
 725 int tdb_traverse_delete_fn(TDB_CONTEXT *the_tdb, TDB_DATA key, TDB_DATA dbuf,
 726                      void *state)
 727 {
 728     return tdb_delete(the_tdb, key);
 729 }
 730
 731
 732
 733 /**
 734  * Search across the whole tdb for keys that match the given pattern
 735  * return the result as a list of keys
 736  *
 737  * @param tdb pointer to opened tdb file context
 738  * @param pattern searching pattern used by fnmatch(3) functions
 739  *
 740  * @return list of keys found by looking up with given pattern
 741  **/
 742 TDB_LIST_NODE *tdb_search_keys(TDB_CONTEXT *tdb, const char* pattern)
 743 {
 744         TDB_DATA key, next;
 745         TDB_LIST_NODE *list = NULL;
 746         TDB_LIST_NODE *rec = NULL;
 747
 748         for (key = tdb_firstkey(tdb); key.dptr; key = next) {
 749                 /* duplicate key string to ensure null-termination */
 750                 char *key_str = SMB_STRNDUP((const char *)key.dptr, key.dsize);
 751                 if (!key_str) {
 752                         DEBUG(0, ("tdb_search_keys: strndup() failed!\n"));
 753                         smb_panic("strndup failed!\n");
 754                 }
 755
 756                 DEBUG(18, ("checking %s for match to pattern %s\n", key_str, pattern));
 757
 758                 next = tdb_nextkey(tdb, key);
 759
 760                 /* do the pattern checking */
 761                 if (fnmatch(pattern, key_str, 0) == 0) {
 762                         rec = SMB_MALLOC_P(TDB_LIST_NODE);
 763                         ZERO_STRUCTP(rec);
 764
 765                         rec->node_key = key;
 766
 767                         DLIST_ADD_END(list, rec, TDB_LIST_NODE *);
 768
 769                         DEBUG(18, ("checking %s matched pattern %s\n", key_str, pattern));
 770                 } else {
 771                         free(key.dptr);
 772                 }
 773
 774                 /* free duplicated key string */
 775                 free(key_str);
 776         }
 777
 778         return list;
 779
 780 }
 781
 782
 783 /**
 784  * Free the list returned by tdb_search_keys
 785  *
 786  * @param node list of results found by tdb_search_keys
 787  **/
 788 void tdb_search_list_free(TDB_LIST_NODE* node)
 789 {
 790         TDB_LIST_NODE *next_node;
 791
 792         while (node) {
 793                 next_node = node->next;
 794                 SAFE_FREE(node->node_key.dptr);
 795                 SAFE_FREE(node);
 796                 node = next_node;
 797         };
 798 }
 799
 800 /****************************************************************************
 801  tdb_store, wrapped in a transaction. This way we make sure that a process
 802  that dies within writing does not leave a corrupt tdb behind.
 803 ****************************************************************************/
 804
 805 int tdb_trans_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf,
 806                     int flag)
 807 {
 808         int res;
 809
 810         if ((res = tdb_transaction_start(tdb)) != 0) {
 811                 DEBUG(5, ("tdb_transaction_start failed\n"));
 812                 return res;
 813         }
 814
 815         if ((res = tdb_store(tdb, key, dbuf, flag)) != 0) {
 816                 DEBUG(10, ("tdb_store failed\n"));
 817                 if (tdb_transaction_cancel(tdb) != 0) {
 818                         smb_panic("Cancelling transaction failed");
 819                 }
 820                 return res;
 821         }
 822
 823         if ((res = tdb_transaction_commit(tdb)) != 0) {
 824                 DEBUG(5, ("tdb_transaction_commit failed\n"));
 825         }
 826
 827         return res;
 828 }
 829
 830 /****************************************************************************
 831  tdb_delete, wrapped in a transaction. This way we make sure that a process
 832  that dies within deleting does not leave a corrupt tdb behind.
 833 ****************************************************************************/
 834
 835 int tdb_trans_delete(struct tdb_context *tdb, TDB_DATA key)
 836 {
 837         int res;
 838
 839         if ((res = tdb_transaction_start(tdb)) != 0) {
 840                 DEBUG(5, ("tdb_transaction_start failed\n"));
 841                 return res;
 842         }
 843
 844         if ((res = tdb_delete(tdb, key)) != 0) {
 845                 DEBUG(10, ("tdb_delete failed\n"));
 846                 if (tdb_transaction_cancel(tdb) != 0) {
 847                         smb_panic("Cancelling transaction failed");
 848                 }
 849                 return res;
 850         }
 851
 852         if ((res = tdb_transaction_commit(tdb)) != 0) {
 853                 DEBUG(5, ("tdb_transaction_commit failed\n"));
 854         }
 855
 856         return res;
 857 }
 858
 859 /*
 860  Log tdb messages via DEBUG().
 861 */
 862 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
 863                          const char *format, ...) PRINTF_ATTRIBUTE(3,4);
 864
 865 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
 866                          const char *format, ...)
 867 {
 868         va_list ap;
 869         char *ptr = NULL;
 870         int debuglevel = 0;
 871         int ret;
 872
 873         switch (level) {
 874         case TDB_DEBUG_FATAL:
 875                 debug_level = 0;
 876                 break;
 877         case TDB_DEBUG_ERROR:
 878                 debuglevel = 1;
 879                 break;
 880         case TDB_DEBUG_WARNING:
 881                 debuglevel = 2;
 882                 break;
 883         case TDB_DEBUG_TRACE:
 884                 debuglevel = 5;
 885                 break;
 886         default:
 887                 debuglevel = 0;
 888         }
 889
 890         va_start(ap, format);
 891         ret = vasprintf(&ptr, format, ap);
 892         va_end(ap);
 893
 894         if (ret != -1) {
 895                 const char *name = tdb_name(tdb);
 896                 DEBUG(debuglevel, ("tdb(%s): %s", name ? name : "unnamed", ptr));
 897                 free(ptr);
 898         }
 899 }
 900
 901 static struct tdb_wrap *tdb_list;
 902
 903 /* destroy the last connection to a tdb */
 904 static int tdb_wrap_destructor(struct tdb_wrap *w)
 905 {
 906         tdb_close(w->tdb);
 907         DLIST_REMOVE(tdb_list, w);
 908         return 0;
 909 }
 910
 911 /*
 912   wrapped connection to a tdb database
 913   to close just talloc_free() the tdb_wrap pointer
 914  */
 915 struct tdb_wrap *tdb_wrap_open(TALLOC_CTX *mem_ctx,
 916                                const char *name, int hash_size, int tdb_flags,
 917                                int open_flags, mode_t mode)
 918 {
 919         struct tdb_wrap *w;
 920         struct tdb_logging_context log_ctx;
 921         log_ctx.log_fn = tdb_wrap_log;
 922
 923         if (!lp_use_mmap())
 924                 tdb_flags |= TDB_NOMMAP;
 925
 926         for (w=tdb_list;w;w=w->next) {
 927                 if (strcmp(name, w->name) == 0) {
 928                         /*
 929                          * Yes, talloc_reference is exactly what we want
 930                          * here. Otherwise we would have to implement our own
 931                          * reference counting.
 932                          */
 933                         return talloc_reference(mem_ctx, w);
 934                 }
 935         }
 936
 937         w = talloc(mem_ctx, struct tdb_wrap);
 938         if (w == NULL) {
 939                 return NULL;
 940         }
 941
 942         if (!(w->name = talloc_strdup(w, name))) {
 943                 talloc_free(w);
 944                 return NULL;
 945         }
 946
 947         if ((hash_size == 0) && (name != NULL)) {
 948                 const char *base = strrchr_m(name, '/');
 949                 if (base != NULL) {
 950                         base += 1;
 951                 }
 952                 else {
 953                         base = name;
 954                 }
 955                 hash_size = lp_parm_int(-1, "tdb_hashsize", base, 0);
 956         }
 957
 958         w->tdb = tdb_open_ex(name, hash_size, tdb_flags,
 959                              open_flags, mode, &log_ctx, NULL);
 960         if (w->tdb == NULL) {
 961                 talloc_free(w);
 962                 return NULL;
 963         }
 964
 965         talloc_set_destructor(w, tdb_wrap_destructor);
 966
 967         DLIST_ADD(tdb_list, w);
 968
 969         return w;
 970 }
 971
 972 NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err)
 973 {
 974         struct { enum TDB_ERROR err; NTSTATUS status; } map[] =
 975                 { { TDB_SUCCESS,        NT_STATUS_OK },
 976                   { TDB_ERR_CORRUPT,    NT_STATUS_INTERNAL_DB_CORRUPTION },
 977                   { TDB_ERR_IO,         NT_STATUS_UNEXPECTED_IO_ERROR },
 978                   { TDB_ERR_OOM,        NT_STATUS_NO_MEMORY },
 979                   { TDB_ERR_EXISTS,     NT_STATUS_OBJECT_NAME_COLLISION },
 980
 981                   /*
 982                    * TDB_ERR_LOCK is very broad, we could for example
 983                    * distinguish between fcntl locks and invalid lock
 984                    * sequences. So NT_STATUS_FILE_LOCK_CONFLICT is a
 985                    * compromise.
 986                    */
 987                   { TDB_ERR_LOCK,       NT_STATUS_FILE_LOCK_CONFLICT },
 988                   /*
 989                    * The next two ones in the enum are not actually used
 990                    */
 991                   { TDB_ERR_NOLOCK,     NT_STATUS_FILE_LOCK_CONFLICT },
 992                   { TDB_ERR_LOCK_TIMEOUT, NT_STATUS_FILE_LOCK_CONFLICT },
 993                   { TDB_ERR_NOEXIST,    NT_STATUS_NOT_FOUND },
 994                   { TDB_ERR_EINVAL,     NT_STATUS_INVALID_PARAMETER },
 995                   { TDB_ERR_RDONLY,     NT_STATUS_ACCESS_DENIED }
 996                 };
 997
 998         int i;
 999
1000         for (i=0; i < sizeof(map) / sizeof(map[0]); i++) {
1001                 if (err == map[i].err) {
1002                         return map[i].status;
1003                 }
1004         }
1005
1006         return NT_STATUS_INTERNAL_ERROR;
1007 }
1008
1009
1010 /*********************************************************************
1011  * the following is a generic validation mechanism for tdbs.
1012  *********************************************************************/
1013
1014 /*
1015  * internal validation function, executed by the child.
1016  */
1017 static int tdb_validate_child(struct tdb_context *tdb,
1018                               tdb_validate_data_func validate_fn)
1019 {
1020         int ret = 1;
1021         int num_entries = 0;
1022         struct tdb_validation_status v_status;
1023
1024         v_status.tdb_error = False;
1025         v_status.bad_freelist = False;
1026         v_status.bad_entry = False;
1027         v_status.unknown_key = False;
1028         v_status.success = True;
1029
1030         if (!tdb) {
1031                 v_status.tdb_error = True;
1032                 v_status.success = False;
1033                 goto out;
1034         }
1035
1036         /* Check if the tdb's freelist is good. */
1037         if (tdb_validate_freelist(tdb, &num_entries) == -1) {
1038                 v_status.bad_freelist = True;
1039                 v_status.success = False;
1040                 goto out;
1041         }
1042
1043         DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
1044                   tdb_name(tdb), num_entries));
1045
1046         /* Now traverse the tdb to validate it. */
1047         num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status);
1048         if (!v_status.success) {
1049                 goto out;
1050         } else if (num_entries == -1) {
1051                 v_status.tdb_error = True;
1052                 v_status.success = False;
1053                 goto out;
1054         }
1055
1056         DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
1057                   tdb_name(tdb), num_entries));
1058         ret = 0; /* Cache is good. */
1059
1060 out:
1061         DEBUG(10,   ("tdb_validate_child: summary of validation status:\n"));
1062         DEBUGADD(10,(" * tdb error: %s\n", v_status.tdb_error ? "yes" : "no"));
1063         DEBUGADD(10,(" * bad freelist: %s\n",v_status.bad_freelist?"yes":"no"));
1064         DEBUGADD(10,(" * bad entry: %s\n", v_status.bad_entry ? "yes" : "no"));
1065         DEBUGADD(10,(" * unknown key: %s\n", v_status.unknown_key?"yes":"no"));
1066         DEBUGADD(10,(" => overall success: %s\n", v_status.success?"yes":"no"));
1067
1068         return ret;
1069 }
1070
1071 /*
1072  * tdb validation function.
1073  * returns 0 if tdb is ok, != 0 if it isn't.
1074  * this function expects an opened tdb.
1075  */
1076 int tdb_validate(struct tdb_context *tdb, tdb_validate_data_func validate_fn)
1077 {
1078         pid_t child_pid = -1;
1079         int child_status = 0;
1080         int wait_pid = 0;
1081         int ret = 1;
1082
1083         if (tdb == NULL) {
1084                 DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
1085                 return ret;
1086         }
1087
1088         DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb)));
1089
1090         /* fork and let the child do the validation.
1091          * benefit: no need to twist signal handlers and panic functions.
1092          * just let the child panic. we catch the signal. */
1093
1094         DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
1095         child_pid = sys_fork();
1096         if (child_pid == 0) {
1097                 /* child code */
1098                 DEBUG(10, ("tdb_validate (validation child): created\n"));
1099                 DEBUG(10, ("tdb_validate (validation child): "
1100                            "calling tdb_validate_child\n"));
1101                 exit(tdb_validate_child(tdb, validate_fn));
1102         }
1103         else if (child_pid < 0) {
1104                 DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
1105                 goto done;
1106         }
1107
1108         /* parent */
1109
1110         DEBUG(10, ("tdb_validate: fork succeeded, child PID = %d\n",child_pid));
1111
1112         DEBUG(10, ("tdb_validate: waiting for child to finish...\n"));
1113         while  ((wait_pid = sys_waitpid(child_pid, &child_status, 0)) < 0) {
1114                 if (errno == EINTR) {
1115                         DEBUG(10, ("tdb_validate: got signal during waitpid, "
1116                                    "retrying\n"));
1117                         errno = 0;
1118                         continue;
1119                 }
1120                 DEBUG(1, ("tdb_validate: waitpid failed with error '%s'.\n",
1121                           strerror(errno)));
1122                 goto done;
1123         }
1124         if (wait_pid != child_pid) {
1125                 DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
1126                           "but %d was expected\n", wait_pid, child_pid));
1127                 goto done;
1128         }
1129
1130         DEBUG(10, ("tdb_validate: validating child returned.\n"));
1131         if (WIFEXITED(child_status)) {
1132                 DEBUG(10, ("tdb_validate: child exited, code %d.\n",
1133                            WEXITSTATUS(child_status)));
1134                 ret = WEXITSTATUS(child_status);
1135         }
1136         if (WIFSIGNALED(child_status)) {
1137                 DEBUG(10, ("tdb_validate: child terminated by signal %d\n",
1138                            WTERMSIG(child_status)));
1139 #ifdef WCOREDUMP
1140                 if (WCOREDUMP(child_status)) {
1141                         DEBUGADD(10, ("core dumped\n"));
1142                 }
1143 #endif
1144                 ret = WTERMSIG(child_status);
1145         }
1146         if (WIFSTOPPED(child_status)) {
1147                 DEBUG(10, ("tdb_validate: child was stopped by signal %d\n",
1148                            WSTOPSIG(child_status)));
1149                 ret = WSTOPSIG(child_status);
1150         }
1151
1152 done:
1153         DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret,
1154                   tdb_name(tdb)));
1155
1156         return ret;
1157 }
1158
1159 /*
1160  * tdb validation function.
1161  * returns 0 if tdb is ok, != 0 if it isn't.
1162  * this is a wrapper around the actual validation function that opens and closes
1163  * the tdb.
1164  */
1165 int tdb_validate_open(const char *tdb_path, tdb_validate_data_func validate_fn)
1166 {
1167         TDB_CONTEXT *tdb = NULL;
1168         int ret = 1;
1169
1170         DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path));
1171
1172         tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDONLY, 0);
1173         if (!tdb) {
1174                 DEBUG(1, ("Error opening tdb %s\n", tdb_path));
1175                 return ret;
1176         }
1177
1178         ret = tdb_validate(tdb, validate_fn);
1179         tdb_close(tdb);
1180         return ret;
1181 }
1182
1183 /*
1184  * tdb backup function and helpers for tdb_validate wrapper with backup
1185  * handling.
1186  */
1187
1188 /* this structure eliminates the need for a global overall status for
1189  * the traverse-copy */
1190 struct tdb_copy_data {
1191         struct tdb_context *dst;
1192         bool success;
1193 };
1194
1195 static int traverse_copy_fn(struct tdb_context *tdb, TDB_DATA key,
1196                             TDB_DATA dbuf, void *private_data)
1197 {
1198         struct tdb_copy_data *data = (struct tdb_copy_data *)private_data;
1199
1200         if (tdb_store(data->dst, key, dbuf, TDB_INSERT) != 0) {
1201                 DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data->dst),
1202                           strerror(errno)));
1203                 data->success = False;
1204                 return 1;
1205         }
1206         return 0;
1207 }
1208
1209 static int tdb_copy(struct tdb_context *src, struct tdb_context *dst)
1210 {
1211         struct tdb_copy_data data;
1212         int count;
1213
1214         data.dst = dst;
1215         data.success = True;
1216
1217         count = tdb_traverse(src, traverse_copy_fn, (void *)(&data));
1218         if ((count < 0) || (data.success == False)) {
1219                 return -1;
1220         }
1221         return count;
1222 }
1223
1224 static int tdb_verify_basic(struct tdb_context *tdb)
1225 {
1226         return tdb_traverse(tdb, NULL, NULL);
1227 }
1228
1229 /* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
1230  */
1231 static int tdb_backup(TALLOC_CTX *ctx, const char *src_path,
1232                       const char *dst_path, int hash_size)
1233 {
1234         struct tdb_context *src_tdb = NULL;
1235         struct tdb_context *dst_tdb = NULL;
1236         char *tmp_path = NULL;
1237         struct stat st;
1238         int count1, count2;
1239         int saved_errno = 0;
1240         int ret = -1;
1241
1242         if (stat(src_path, &st) != 0) {
1243                 DEBUG(3, ("Could not stat '%s': %s\n", src_path,
1244                           strerror(errno)));
1245                 goto done;
1246         }
1247
1248         /* open old tdb RDWR - so we can lock it */
1249         src_tdb = tdb_open_log(src_path, 0, TDB_DEFAULT, O_RDWR, 0);
1250         if (src_tdb == NULL) {
1251                 DEBUG(3, ("Failed to open tdb '%s'\n", src_path));
1252                 goto done;
1253         }
1254
1255         if (tdb_lockall(src_tdb) != 0) {
1256                 DEBUG(3, ("Failed to lock tdb '%s'\n", src_path));
1257                 goto done;
1258         }
1259
1260         tmp_path = talloc_asprintf(ctx, "%s%s", dst_path, ".tmp");
1261         unlink(tmp_path);
1262         dst_tdb = tdb_open_log(tmp_path,
1263                                hash_size ? hash_size : tdb_hash_size(src_tdb),
1264                                TDB_DEFAULT, O_RDWR | O_CREAT | O_EXCL,
1265                                st.st_mode & 0777);
1266         if (dst_tdb == NULL) {
1267                 DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path,
1268                           strerror(errno)));
1269                 saved_errno = errno;
1270                 unlink(tmp_path);
1271                 goto done;
1272         }
1273
1274         count1 = tdb_copy(src_tdb, dst_tdb);
1275         if (count1 < 0) {
1276                 DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path,
1277                           strerror(errno)));
1278                 tdb_close(dst_tdb);
1279                 goto done;
1280         }
1281
1282         /* reopen ro and do basic verification */
1283         tdb_close(dst_tdb);
1284         dst_tdb = tdb_open_log(tmp_path, 0, TDB_DEFAULT, O_RDONLY, 0);
1285         if (!dst_tdb) {
1286                 DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path,
1287                           strerror(errno)));
1288                 goto done;
1289         }
1290         count2 = tdb_verify_basic(dst_tdb);
1291         if (count2 != count1) {
1292                 DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
1293                           src_path));
1294                 tdb_close(dst_tdb);
1295                 goto done;
1296         }
1297
1298         DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1));
1299
1300         /* make sure the new tdb has reached stable storage
1301          * then rename it to its destination */
1302         fsync(tdb_fd(dst_tdb));
1303         tdb_close(dst_tdb);
1304         unlink(dst_path);
1305         if (rename(tmp_path, dst_path) != 0) {
1306                 DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
1307                           tmp_path, dst_path, strerror(errno)));
1308                 goto done;
1309         }
1310
1311         /* success */
1312         ret = 0;
1313
1314 done:
1315         if (src_tdb != NULL) {
1316                 tdb_close(src_tdb);
1317         }
1318         if (tmp_path != NULL) {
1319                 unlink(tmp_path);
1320                 TALLOC_FREE(tmp_path);
1321         }
1322         if (saved_errno != 0) {
1323                 errno = saved_errno;
1324         }
1325         return ret;
1326 }
1327
1328 static int rename_file_with_suffix(TALLOC_CTX *ctx, const char *path,
1329                                    const char *suffix)
1330 {
1331         int ret = -1;
1332         char *dst_path;
1333
1334         dst_path = talloc_asprintf(ctx, "%s%s", path, suffix);
1335
1336         ret = (rename(path, dst_path) != 0);
1337
1338         if (ret == 0) {
1339                 DEBUG(5, ("moved '%s' to '%s'\n", path, dst_path));
1340         } else if (errno == ENOENT) {
1341                 DEBUG(3, ("file '%s' does not exist - so not moved\n", path));
1342                 ret = 0;
1343         } else {
1344                 DEBUG(3, ("error renaming %s to %s: %s\n", path, dst_path,
1345                           strerror(errno)));
1346         }
1347
1348         TALLOC_FREE(dst_path);
1349         return ret;
1350 }
1351
1352 /*
1353  * do a backup of a tdb, moving the destination out of the way first
1354  */
1355 static int tdb_backup_with_rotate(TALLOC_CTX *ctx, const char *src_path,
1356                                   const char *dst_path, int hash_size,
1357                                   const char *rotate_suffix,
1358                                   bool retry_norotate_if_nospc,
1359                                   bool rename_as_last_resort_if_nospc)
1360 {
1361         int ret;
1362
1363         rename_file_with_suffix(ctx, dst_path, rotate_suffix);
1364
1365         ret = tdb_backup(ctx, src_path, dst_path, hash_size);
1366
1367         if (ret != 0) {
1368                 DEBUG(10, ("backup of %s failed: %s\n", src_path, strerror(errno)));
1369         }
1370         if ((ret != 0) && (errno == ENOSPC) && retry_norotate_if_nospc)
1371         {
1372                 char *rotate_path = talloc_asprintf(ctx, "%s%s", dst_path,
1373                                                     rotate_suffix);
1374                 DEBUG(10, ("backup of %s failed due to lack of space\n",
1375                            src_path));
1376                 DEBUGADD(10, ("trying to free some space by removing rotated "
1377                               "dst %s\n", rotate_path));
1378                 if (unlink(rotate_path) == -1) {
1379                         DEBUG(10, ("unlink of %s failed: %s\n", rotate_path,
1380                                    strerror(errno)));
1381                 } else {
1382                         ret = tdb_backup(ctx, src_path, dst_path, hash_size);
1383                 }
1384                 TALLOC_FREE(rotate_path);
1385         }
1386
1387         if ((ret != 0) && (errno == ENOSPC) && rename_as_last_resort_if_nospc)
1388         {
1389                 DEBUG(10, ("backup of %s failed due to lack of space\n",
1390                            src_path));
1391                 DEBUGADD(10, ("using 'rename' as a last resort\n"));
1392                 ret = rename(src_path, dst_path);
1393         }
1394
1395         return ret;
1396 }
1397
1398 /*
1399  * validation function with backup handling:
1400  *
1401  *  - calls tdb_validate
1402  *  - if the tdb is ok, create a backup "name.bak", possibly moving
1403  *    existing backup to name.bak.old,
1404  *    return 0 (success) even if the backup fails
1405  *  - if the tdb is corrupt:
1406  *    - move the tdb to "name.corrupt"
1407  *    - check if there is valid backup.
1408  *      if so, restore the backup.
1409  *      if restore is successful, return 0 (success),
1410  *    - otherwise return -1 (failure)
1411  */
1412 int tdb_validate_and_backup(const char *tdb_path,
1413                             tdb_validate_data_func validate_fn)
1414 {
1415         int ret = -1;
1416         const char *backup_suffix = ".bak";
1417         const char *corrupt_suffix = ".corrupt";
1418         const char *rotate_suffix = ".old";
1419         char *tdb_path_backup;
1420         struct stat st;
1421         TALLOC_CTX *ctx = NULL;
1422
1423         ctx = talloc_new(NULL);
1424         if (ctx == NULL) {
1425                 DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
1426                 goto done;
1427         }
1428
1429         tdb_path_backup = talloc_asprintf(ctx, "%s%s", tdb_path, backup_suffix);
1430
1431         ret = tdb_validate_open(tdb_path, validate_fn);
1432
1433         if (ret == 0) {
1434                 DEBUG(1, ("tdb '%s' is valid\n", tdb_path));
1435                 ret = tdb_backup_with_rotate(ctx, tdb_path, tdb_path_backup, 0,
1436                                              rotate_suffix, True, False);
1437                 if (ret != 0) {
1438                         DEBUG(1, ("Error creating backup of tdb '%s'\n",
1439                                   tdb_path));
1440                         /* the actual validation was successful: */
1441                         ret = 0;
1442                 } else {
1443                         DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
1444                                   tdb_path_backup, tdb_path));
1445                 }
1446         } else {
1447                 DEBUG(1, ("tdb '%s' is invalid\n", tdb_path));
1448
1449                 ret =stat(tdb_path_backup, &st);
1450                 if (ret != 0) {
1451                         DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup,
1452                                   strerror(errno)));
1453                         DEBUG(1, ("No backup found.\n"));
1454                 } else {
1455                         DEBUG(1, ("backup '%s' found.\n", tdb_path_backup));
1456                         ret = tdb_validate_open(tdb_path_backup, validate_fn);
1457                         if (ret != 0) {
1458                                 DEBUG(1, ("Backup '%s' is invalid.\n",
1459                                           tdb_path_backup));
1460                         }
1461                 }
1462
1463                 if (ret != 0) {
1464                         int renamed = rename_file_with_suffix(ctx, tdb_path,
1465                                                               corrupt_suffix);
1466                         if (renamed != 0) {
1467                                 DEBUG(1, ("Error moving tdb to '%s%s'\n",
1468                                           tdb_path, corrupt_suffix));
1469                         } else {
1470                                 DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
1471                                           tdb_path, corrupt_suffix));
1472                         }
1473                         goto done;
1474                 }
1475
1476                 DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup));
1477                 ret = tdb_backup_with_rotate(ctx, tdb_path_backup, tdb_path, 0,
1478                                              corrupt_suffix, True, True);
1479                 if (ret != 0) {
1480                         DEBUG(1, ("Error restoring backup from '%s'\n",
1481                                   tdb_path_backup));
1482                 } else {
1483                         DEBUG(1, ("Restored tdb backup from '%s'\n",
1484                                   tdb_path_backup));
1485                 }
1486         }
1487
1488 done:
1489         TALLOC_FREE(ctx);
1490         return ret;
1491 }