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    Copyright (C) Michael Adam      2007
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #undef malloc
  24 #undef realloc
  25 #undef calloc
  26 #undef strdup
  27
  28 /* these are little tdb utility functions that are meant to make
  29    dealing with a tdb database a little less cumbersome in Samba */
  30
  31 static SIG_ATOMIC_T gotalarm;
  32
  33 /***************************************************************
  34  Signal function to tell us we timed out.
  35 ****************************************************************/
  36
  37 static void gotalarm_sig(void)
  38 {
  39         gotalarm = 1;
  40 }
  41
  42 /****************************************************************************
  43  Lock a chain with timeout (in seconds).
  44 ****************************************************************************/
  45
  46 static int tdb_chainlock_with_timeout_internal( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout, int rw_type)
  47 {
  48         /* Allow tdb_chainlock to be interrupted by an alarm. */
  49         int ret;
  50         gotalarm = 0;
  51
  52         if (timeout) {
  53                 CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
  54                 tdb_setalarm_sigptr(tdb, &gotalarm);
  55                 alarm(timeout);
  56         }
  57
  58         if (rw_type == F_RDLCK)
  59                 ret = tdb_chainlock_read(tdb, key);
  60         else
  61                 ret = tdb_chainlock(tdb, key);
  62
  63         if (timeout) {
  64                 alarm(0);
  65                 tdb_setalarm_sigptr(tdb, NULL);
  66                 CatchSignal(SIGALRM, SIGNAL_CAST SIG_IGN);
  67                 if (gotalarm && (ret == -1)) {
  68                         DEBUG(0,("tdb_chainlock_with_timeout_internal: alarm (%u) timed out for key %s in tdb %s\n",
  69                                 timeout, key.dptr, tdb_name(tdb)));
  70                         /* TODO: If we time out waiting for a lock, it might
  71                          * be nice to use F_GETLK to get the pid of the
  72                          * process currently holding the lock and print that
  73                          * as part of the debugging message. -- mbp */
  74                         return -1;
  75                 }
  76         }
  77
  78         return ret;
  79 }
  80
  81 /****************************************************************************
  82  Write lock a chain. Return -1 if timeout or lock failed.
  83 ****************************************************************************/
  84
  85 int tdb_chainlock_with_timeout( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout)
  86 {
  87         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_WRLCK);
  88 }
  89
  90 int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval,
  91                                    int timeout)
  92 {
  93         TDB_DATA key = string_term_tdb_data(keyval);
  94
  95         return tdb_chainlock_with_timeout(tdb, key, timeout);
  96 }
  97
  98 /****************************************************************************
  99  Read lock a chain by string. Return -1 if timeout or lock failed.
 100 ****************************************************************************/
 101
 102 int tdb_read_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, unsigned int timeout)
 103 {
 104         TDB_DATA key = string_term_tdb_data(keyval);
 105
 106         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_RDLCK);
 107 }
 108
 109
 110
 111
 112 int tdb_trans_store_bystring(TDB_CONTEXT *tdb, const char *keystr,
 113                              TDB_DATA data, int flags)
 114 {
 115         TDB_DATA key = string_term_tdb_data(keystr);
 116
 117         return tdb_trans_store(tdb, key, data, flags);
 118 }
 119
 120 /****************************************************************************
 121  Useful pair of routines for packing/unpacking data consisting of
 122  integers and strings.
 123 ****************************************************************************/
 124
 125 static size_t tdb_pack_va(uint8 *buf, int bufsize, const char *fmt, va_list ap)
 126 {
 127         uint8 bt;
 128         uint16 w;
 129         uint32 d;
 130         int i;
 131         void *p;
 132         int len;
 133         char *s;
 134         char c;
 135         uint8 *buf0 = buf;
 136         const char *fmt0 = fmt;
 137         int bufsize0 = bufsize;
 138
 139         while (*fmt) {
 140                 switch ((c = *fmt++)) {
 141                 case 'b': /* unsigned 8-bit integer */
 142                         len = 1;
 143                         bt = (uint8)va_arg(ap, int);
 144                         if (bufsize && bufsize >= len)
 145                                 SSVAL(buf, 0, bt);
 146                         break;
 147                 case 'w': /* unsigned 16-bit integer */
 148                         len = 2;
 149                         w = (uint16)va_arg(ap, int);
 150                         if (bufsize && bufsize >= len)
 151                                 SSVAL(buf, 0, w);
 152                         break;
 153                 case 'd': /* signed 32-bit integer (standard int in most systems) */
 154                         len = 4;
 155                         d = va_arg(ap, uint32);
 156                         if (bufsize && bufsize >= len)
 157                                 SIVAL(buf, 0, d);
 158                         break;
 159                 case 'p': /* pointer */
 160                         len = 4;
 161                         p = va_arg(ap, void *);
 162                         d = p?1:0;
 163                         if (bufsize && bufsize >= len)
 164                                 SIVAL(buf, 0, d);
 165                         break;
 166                 case 'P': /* null-terminated string */
 167                         s = va_arg(ap,char *);
 168                         w = strlen(s);
 169                         len = w + 1;
 170                         if (bufsize && bufsize >= len)
 171                                 memcpy(buf, s, len);
 172                         break;
 173                 case 'f': /* null-terminated string */
 174                         s = va_arg(ap,char *);
 175                         w = strlen(s);
 176                         len = w + 1;
 177                         if (bufsize && bufsize >= len)
 178                                 memcpy(buf, s, len);
 179                         break;
 180                 case 'B': /* fixed-length string */
 181                         i = va_arg(ap, int);
 182                         s = va_arg(ap, char *);
 183                         len = 4+i;
 184                         if (bufsize && bufsize >= len) {
 185                                 SIVAL(buf, 0, i);
 186                                 memcpy(buf+4, s, i);
 187                         }
 188                         break;
 189                 default:
 190                         DEBUG(0,("Unknown tdb_pack format %c in %s\n",
 191                                  c, fmt));
 192                         len = 0;
 193                         break;
 194                 }
 195
 196                 buf += len;
 197                 if (bufsize)
 198                         bufsize -= len;
 199                 if (bufsize < 0)
 200                         bufsize = 0;
 201         }
 202
 203         DEBUG(18,("tdb_pack_va(%s, %d) -> %d\n",
 204                  fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
 205
 206         return PTR_DIFF(buf, buf0);
 207 }
 208
 209 size_t tdb_pack(uint8 *buf, int bufsize, const char *fmt, ...)
 210 {
 211         va_list ap;
 212         size_t result;
 213
 214         va_start(ap, fmt);
 215         result = tdb_pack_va(buf, bufsize, fmt, ap);
 216         va_end(ap);
 217         return result;
 218 }
 219
 220 bool tdb_pack_append(TALLOC_CTX *mem_ctx, uint8 **buf, size_t *len,
 221                      const char *fmt, ...)
 222 {
 223         va_list ap;
 224         size_t len1, len2;
 225
 226         va_start(ap, fmt);
 227         len1 = tdb_pack_va(NULL, 0, fmt, ap);
 228         va_end(ap);
 229
 230         if (mem_ctx != NULL) {
 231                 *buf = TALLOC_REALLOC_ARRAY(mem_ctx, *buf, uint8,
 232                                             (*len) + len1);
 233         } else {
 234                 *buf = SMB_REALLOC_ARRAY(*buf, uint8, (*len) + len1);
 235         }
 236
 237         if (*buf == NULL) {
 238                 return False;
 239         }
 240
 241         va_start(ap, fmt);
 242         len2 = tdb_pack_va((*buf)+(*len), len1, fmt, ap);
 243         va_end(ap);
 244
 245         if (len1 != len2) {
 246                 return False;
 247         }
 248
 249         *len += len2;
 250
 251         return True;
 252 }
 253
 254 /****************************************************************************
 255  Useful pair of routines for packing/unpacking data consisting of
 256  integers and strings.
 257 ****************************************************************************/
 258
 259 int tdb_unpack(const uint8 *buf, int bufsize, const char *fmt, ...)
 260 {
 261         va_list ap;
 262         uint8 *bt;
 263         uint16 *w;
 264         uint32 *d;
 265         int len;
 266         int *i;
 267         void **p;
 268         char *s, **b, **ps;
 269         char c;
 270         const uint8 *buf0 = buf;
 271         const char *fmt0 = fmt;
 272         int bufsize0 = bufsize;
 273
 274         va_start(ap, fmt);
 275
 276         while (*fmt) {
 277                 switch ((c=*fmt++)) {
 278                 case 'b': /* unsigned 8-bit integer */
 279                         len = 1;
 280                         bt = va_arg(ap, uint8 *);
 281                         if (bufsize < len)
 282                                 goto no_space;
 283                         *bt = SVAL(buf, 0);
 284                         break;
 285                 case 'w': /* unsigned 16-bit integer */
 286                         len = 2;
 287                         w = va_arg(ap, uint16 *);
 288                         if (bufsize < len)
 289                                 goto no_space;
 290                         *w = SVAL(buf, 0);
 291                         break;
 292                 case 'd': /* signed 32-bit integer (standard int in most systems) */
 293                         len = 4;
 294                         d = va_arg(ap, uint32 *);
 295                         if (bufsize < len)
 296                                 goto no_space;
 297                         *d = IVAL(buf, 0);
 298                         break;
 299                 case 'p': /* pointer */
 300                         len = 4;
 301                         p = va_arg(ap, void **);
 302                         if (bufsize < len)
 303                                 goto no_space;
 304                         /*
 305                          * This isn't a real pointer - only a token (1 or 0)
 306                          * to mark the fact a pointer is present.
 307                          */
 308
 309                         *p = (void *)(IVAL(buf, 0) ? (void *)1 : NULL);
 310                         break;
 311                 case 'P': /* null-terminated string */
 312                         /* Return malloc'ed string. */
 313                         ps = va_arg(ap,char **);
 314                         len = strlen((const char *)buf) + 1;
 315                         *ps = SMB_STRDUP((const char *)buf);
 316                         break;
 317                 case 'f': /* null-terminated string */
 318                         s = va_arg(ap,char *);
 319                         len = strlen((const char *)buf) + 1;
 320                         if (bufsize < len || len > sizeof(fstring))
 321                                 goto no_space;
 322                         memcpy(s, buf, len);
 323                         break;
 324                 case 'B': /* fixed-length string */
 325                         i = va_arg(ap, int *);
 326                         b = va_arg(ap, char **);
 327                         len = 4;
 328                         if (bufsize < len)
 329                                 goto no_space;
 330                         *i = IVAL(buf, 0);
 331                         if (! *i) {
 332                                 *b = NULL;
 333                                 break;
 334                         }
 335                         len += *i;
 336                         if (bufsize < len)
 337                                 goto no_space;
 338                         *b = (char *)SMB_MALLOC(*i);
 339                         if (! *b)
 340                                 goto no_space;
 341                         memcpy(*b, buf+4, *i);
 342                         break;
 343                 default:
 344                         DEBUG(0,("Unknown tdb_unpack format %c in %s\n",
 345                                  c, fmt));
 346
 347                         len = 0;
 348                         break;
 349                 }
 350
 351                 buf += len;
 352                 bufsize -= len;
 353         }
 354
 355         va_end(ap);
 356
 357         DEBUG(18,("tdb_unpack(%s, %d) -> %d\n",
 358                  fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
 359
 360         return PTR_DIFF(buf, buf0);
 361
 362  no_space:
 363         va_end(ap);
 364         return -1;
 365 }
 366
 367
 368 /****************************************************************************
 369  Log tdb messages via DEBUG().
 370 ****************************************************************************/
 371
 372 static void tdb_log(TDB_CONTEXT *tdb, enum tdb_debug_level level, const char *format, ...)
 373 {
 374         va_list ap;
 375         char *ptr = NULL;
 376         int ret;
 377
 378         va_start(ap, format);
 379         ret = vasprintf(&ptr, format, ap);
 380         va_end(ap);
 381
 382         if ((ret == -1) || !*ptr)
 383                 return;
 384
 385         DEBUG((int)level, ("tdb(%s): %s", tdb_name(tdb) ? tdb_name(tdb) : "unnamed", ptr));
 386         SAFE_FREE(ptr);
 387 }
 388
 389 /****************************************************************************
 390  Like tdb_open() but also setup a logging function that redirects to
 391  the samba DEBUG() system.
 392 ****************************************************************************/
 393
 394 TDB_CONTEXT *tdb_open_log(const char *name, int hash_size, int tdb_flags,
 395                           int open_flags, mode_t mode)
 396 {
 397         TDB_CONTEXT *tdb;
 398         struct tdb_logging_context log_ctx;
 399
 400         if (!lp_use_mmap())
 401                 tdb_flags |= TDB_NOMMAP;
 402
 403         log_ctx.log_fn = tdb_log;
 404         log_ctx.log_private = NULL;
 405
 406         if ((hash_size == 0) && (name != NULL)) {
 407                 const char *base = strrchr_m(name, '/');
 408                 if (base != NULL) {
 409                         base += 1;
 410                 }
 411                 else {
 412                         base = name;
 413                 }
 414                 hash_size = lp_parm_int(-1, "tdb_hashsize", base, 0);
 415         }
 416
 417         tdb = tdb_open_ex(name, hash_size, tdb_flags,
 418                           open_flags, mode, &log_ctx, NULL);
 419         if (!tdb)
 420                 return NULL;
 421
 422         return tdb;
 423 }
 424
 425 /****************************************************************************
 426  tdb_store, wrapped in a transaction. This way we make sure that a process
 427  that dies within writing does not leave a corrupt tdb behind.
 428 ****************************************************************************/
 429
 430 int tdb_trans_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf,
 431                     int flag)
 432 {
 433         int res;
 434
 435         if ((res = tdb_transaction_start(tdb)) != 0) {
 436                 DEBUG(5, ("tdb_transaction_start failed\n"));
 437                 return res;
 438         }
 439
 440         if ((res = tdb_store(tdb, key, dbuf, flag)) != 0) {
 441                 DEBUG(10, ("tdb_store failed\n"));
 442                 if (tdb_transaction_cancel(tdb) != 0) {
 443                         smb_panic("Cancelling transaction failed");
 444                 }
 445                 return res;
 446         }
 447
 448         if ((res = tdb_transaction_commit(tdb)) != 0) {
 449                 DEBUG(5, ("tdb_transaction_commit failed\n"));
 450         }
 451
 452         return res;
 453 }
 454
 455 /****************************************************************************
 456  tdb_delete, wrapped in a transaction. This way we make sure that a process
 457  that dies within deleting does not leave a corrupt tdb behind.
 458 ****************************************************************************/
 459
 460 int tdb_trans_delete(struct tdb_context *tdb, TDB_DATA key)
 461 {
 462         int res;
 463
 464         if ((res = tdb_transaction_start(tdb)) != 0) {
 465                 DEBUG(5, ("tdb_transaction_start failed\n"));
 466                 return res;
 467         }
 468
 469         if ((res = tdb_delete(tdb, key)) != 0) {
 470                 DEBUG(10, ("tdb_delete failed\n"));
 471                 if (tdb_transaction_cancel(tdb) != 0) {
 472                         smb_panic("Cancelling transaction failed");
 473                 }
 474                 return res;
 475         }
 476
 477         if ((res = tdb_transaction_commit(tdb)) != 0) {
 478                 DEBUG(5, ("tdb_transaction_commit failed\n"));
 479         }
 480
 481         return res;
 482 }
 483
 484 /*
 485  Log tdb messages via DEBUG().
 486 */
 487 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
 488                          const char *format, ...) PRINTF_ATTRIBUTE(3,4);
 489
 490 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
 491                          const char *format, ...)
 492 {
 493         va_list ap;
 494         char *ptr = NULL;
 495         int debuglevel = 0;
 496         int ret;
 497
 498         switch (level) {
 499         case TDB_DEBUG_FATAL:
 500                 debuglevel = 0;
 501                 break;
 502         case TDB_DEBUG_ERROR:
 503                 debuglevel = 1;
 504                 break;
 505         case TDB_DEBUG_WARNING:
 506                 debuglevel = 2;
 507                 break;
 508         case TDB_DEBUG_TRACE:
 509                 debuglevel = 5;
 510                 break;
 511         default:
 512                 debuglevel = 0;
 513         }
 514
 515         va_start(ap, format);
 516         ret = vasprintf(&ptr, format, ap);
 517         va_end(ap);
 518
 519         if (ret != -1) {
 520                 const char *name = tdb_name(tdb);
 521                 DEBUG(debuglevel, ("tdb(%s): %s", name ? name : "unnamed", ptr));
 522                 free(ptr);
 523         }
 524 }
 525
 526 static struct tdb_wrap *tdb_list;
 527
 528 /* destroy the last connection to a tdb */
 529 static int tdb_wrap_destructor(struct tdb_wrap *w)
 530 {
 531         tdb_close(w->tdb);
 532         DLIST_REMOVE(tdb_list, w);
 533         return 0;
 534 }
 535
 536 /*
 537   wrapped connection to a tdb database
 538   to close just talloc_free() the tdb_wrap pointer
 539  */
 540 struct tdb_wrap *tdb_wrap_open(TALLOC_CTX *mem_ctx,
 541                                const char *name, int hash_size, int tdb_flags,
 542                                int open_flags, mode_t mode)
 543 {
 544         struct tdb_wrap *w;
 545         struct tdb_logging_context log_ctx;
 546         log_ctx.log_fn = tdb_wrap_log;
 547
 548         if (!lp_use_mmap())
 549                 tdb_flags |= TDB_NOMMAP;
 550
 551         for (w=tdb_list;w;w=w->next) {
 552                 if (strcmp(name, w->name) == 0) {
 553                         /*
 554                          * Yes, talloc_reference is exactly what we want
 555                          * here. Otherwise we would have to implement our own
 556                          * reference counting.
 557                          */
 558                         return talloc_reference(mem_ctx, w);
 559                 }
 560         }
 561
 562         w = talloc(mem_ctx, struct tdb_wrap);
 563         if (w == NULL) {
 564                 return NULL;
 565         }
 566
 567         if (!(w->name = talloc_strdup(w, name))) {
 568                 talloc_free(w);
 569                 return NULL;
 570         }
 571
 572         if ((hash_size == 0) && (name != NULL)) {
 573                 const char *base = strrchr_m(name, '/');
 574                 if (base != NULL) {
 575                         base += 1;
 576                 }
 577                 else {
 578                         base = name;
 579                 }
 580                 hash_size = lp_parm_int(-1, "tdb_hashsize", base, 0);
 581         }
 582
 583         w->tdb = tdb_open_ex(name, hash_size, tdb_flags,
 584                              open_flags, mode, &log_ctx, NULL);
 585         if (w->tdb == NULL) {
 586                 talloc_free(w);
 587                 return NULL;
 588         }
 589
 590         talloc_set_destructor(w, tdb_wrap_destructor);
 591
 592         DLIST_ADD(tdb_list, w);
 593
 594         return w;
 595 }
 596
 597 NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err)
 598 {
 599         struct { enum TDB_ERROR err; NTSTATUS status; } map[] =
 600                 { { TDB_SUCCESS,        NT_STATUS_OK },
 601                   { TDB_ERR_CORRUPT,    NT_STATUS_INTERNAL_DB_CORRUPTION },
 602                   { TDB_ERR_IO,         NT_STATUS_UNEXPECTED_IO_ERROR },
 603                   { TDB_ERR_OOM,        NT_STATUS_NO_MEMORY },
 604                   { TDB_ERR_EXISTS,     NT_STATUS_OBJECT_NAME_COLLISION },
 605
 606                   /*
 607                    * TDB_ERR_LOCK is very broad, we could for example
 608                    * distinguish between fcntl locks and invalid lock
 609                    * sequences. So NT_STATUS_FILE_LOCK_CONFLICT is a
 610                    * compromise.
 611                    */
 612                   { TDB_ERR_LOCK,       NT_STATUS_FILE_LOCK_CONFLICT },
 613                   /*
 614                    * The next two ones in the enum are not actually used
 615                    */
 616                   { TDB_ERR_NOLOCK,     NT_STATUS_FILE_LOCK_CONFLICT },
 617                   { TDB_ERR_LOCK_TIMEOUT, NT_STATUS_FILE_LOCK_CONFLICT },
 618                   { TDB_ERR_NOEXIST,    NT_STATUS_NOT_FOUND },
 619                   { TDB_ERR_EINVAL,     NT_STATUS_INVALID_PARAMETER },
 620                   { TDB_ERR_RDONLY,     NT_STATUS_ACCESS_DENIED }
 621                 };
 622
 623         int i;
 624
 625         for (i=0; i < sizeof(map) / sizeof(map[0]); i++) {
 626                 if (err == map[i].err) {
 627                         return map[i].status;
 628                 }
 629         }
 630
 631         return NT_STATUS_INTERNAL_ERROR;
 632 }
 633
 634
 635 /*********************************************************************
 636  * the following is a generic validation mechanism for tdbs.
 637  *********************************************************************/
 638
 639 /*
 640  * internal validation function, executed by the child.
 641  */
 642 static int tdb_validate_child(struct tdb_context *tdb,
 643                               tdb_validate_data_func validate_fn)
 644 {
 645         int ret = 1;
 646         int num_entries = 0;
 647         struct tdb_validation_status v_status;
 648
 649         v_status.tdb_error = False;
 650         v_status.bad_freelist = False;
 651         v_status.bad_entry = False;
 652         v_status.unknown_key = False;
 653         v_status.success = True;
 654
 655         if (!tdb) {
 656                 v_status.tdb_error = True;
 657                 v_status.success = False;
 658                 goto out;
 659         }
 660
 661         /* Check if the tdb's freelist is good. */
 662         if (tdb_validate_freelist(tdb, &num_entries) == -1) {
 663                 v_status.bad_freelist = True;
 664                 v_status.success = False;
 665                 goto out;
 666         }
 667
 668         DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
 669                   tdb_name(tdb), num_entries));
 670
 671         /* Now traverse the tdb to validate it. */
 672         num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status);
 673         if (!v_status.success) {
 674                 goto out;
 675         } else if (num_entries == -1) {
 676                 v_status.tdb_error = True;
 677                 v_status.success = False;
 678                 goto out;
 679         }
 680
 681         DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
 682                   tdb_name(tdb), num_entries));
 683         ret = 0; /* Cache is good. */
 684
 685 out:
 686         DEBUG(10,   ("tdb_validate_child: summary of validation status:\n"));
 687         DEBUGADD(10,(" * tdb error: %s\n", v_status.tdb_error ? "yes" : "no"));
 688         DEBUGADD(10,(" * bad freelist: %s\n",v_status.bad_freelist?"yes":"no"));
 689         DEBUGADD(10,(" * bad entry: %s\n", v_status.bad_entry ? "yes" : "no"));
 690         DEBUGADD(10,(" * unknown key: %s\n", v_status.unknown_key?"yes":"no"));
 691         DEBUGADD(10,(" => overall success: %s\n", v_status.success?"yes":"no"));
 692
 693         return ret;
 694 }
 695
 696 /*
 697  * tdb validation function.
 698  * returns 0 if tdb is ok, != 0 if it isn't.
 699  * this function expects an opened tdb.
 700  */
 701 int tdb_validate(struct tdb_context *tdb, tdb_validate_data_func validate_fn)
 702 {
 703         pid_t child_pid = -1;
 704         int child_status = 0;
 705         int wait_pid = 0;
 706         int ret = 1;
 707
 708         if (tdb == NULL) {
 709                 DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
 710                 return ret;
 711         }
 712
 713         DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb)));
 714
 715         /* fork and let the child do the validation.
 716          * benefit: no need to twist signal handlers and panic functions.
 717          * just let the child panic. we catch the signal. */
 718
 719         DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
 720         child_pid = sys_fork();
 721         if (child_pid == 0) {
 722                 /* child code */
 723                 DEBUG(10, ("tdb_validate (validation child): created\n"));
 724                 DEBUG(10, ("tdb_validate (validation child): "
 725                            "calling tdb_validate_child\n"));
 726                 exit(tdb_validate_child(tdb, validate_fn));
 727         }
 728         else if (child_pid < 0) {
 729                 DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
 730                 goto done;
 731         }
 732
 733         /* parent */
 734
 735         DEBUG(10, ("tdb_validate: fork succeeded, child PID = %d\n",child_pid));
 736
 737         DEBUG(10, ("tdb_validate: waiting for child to finish...\n"));
 738         while  ((wait_pid = sys_waitpid(child_pid, &child_status, 0)) < 0) {
 739                 if (errno == EINTR) {
 740                         DEBUG(10, ("tdb_validate: got signal during waitpid, "
 741                                    "retrying\n"));
 742                         errno = 0;
 743                         continue;
 744                 }
 745                 DEBUG(1, ("tdb_validate: waitpid failed with error '%s'.\n",
 746                           strerror(errno)));
 747                 goto done;
 748         }
 749         if (wait_pid != child_pid) {
 750                 DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
 751                           "but %d was expected\n", wait_pid, child_pid));
 752                 goto done;
 753         }
 754
 755         DEBUG(10, ("tdb_validate: validating child returned.\n"));
 756         if (WIFEXITED(child_status)) {
 757                 DEBUG(10, ("tdb_validate: child exited, code %d.\n",
 758                            WEXITSTATUS(child_status)));
 759                 ret = WEXITSTATUS(child_status);
 760         }
 761         if (WIFSIGNALED(child_status)) {
 762                 DEBUG(10, ("tdb_validate: child terminated by signal %d\n",
 763                            WTERMSIG(child_status)));
 764 #ifdef WCOREDUMP
 765                 if (WCOREDUMP(child_status)) {
 766                         DEBUGADD(10, ("core dumped\n"));
 767                 }
 768 #endif
 769                 ret = WTERMSIG(child_status);
 770         }
 771         if (WIFSTOPPED(child_status)) {
 772                 DEBUG(10, ("tdb_validate: child was stopped by signal %d\n",
 773                            WSTOPSIG(child_status)));
 774                 ret = WSTOPSIG(child_status);
 775         }
 776
 777 done:
 778         DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret,
 779                   tdb_name(tdb)));
 780
 781         return ret;
 782 }
 783
 784 /*
 785  * tdb validation function.
 786  * returns 0 if tdb is ok, != 0 if it isn't.
 787  * this is a wrapper around the actual validation function that opens and closes
 788  * the tdb.
 789  */
 790 int tdb_validate_open(const char *tdb_path, tdb_validate_data_func validate_fn)
 791 {
 792         TDB_CONTEXT *tdb = NULL;
 793         int ret = 1;
 794
 795         DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path));
 796
 797         tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDONLY, 0);
 798         if (!tdb) {
 799                 DEBUG(1, ("Error opening tdb %s\n", tdb_path));
 800                 return ret;
 801         }
 802
 803         ret = tdb_validate(tdb, validate_fn);
 804         tdb_close(tdb);
 805         return ret;
 806 }
 807
 808 /*
 809  * tdb backup function and helpers for tdb_validate wrapper with backup
 810  * handling.
 811  */
 812
 813 /* this structure eliminates the need for a global overall status for
 814  * the traverse-copy */
 815 struct tdb_copy_data {
 816         struct tdb_context *dst;
 817         bool success;
 818 };
 819
 820 static int traverse_copy_fn(struct tdb_context *tdb, TDB_DATA key,
 821                             TDB_DATA dbuf, void *private_data)
 822 {
 823         struct tdb_copy_data *data = (struct tdb_copy_data *)private_data;
 824
 825         if (tdb_store(data->dst, key, dbuf, TDB_INSERT) != 0) {
 826                 DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data->dst),
 827                           strerror(errno)));
 828                 data->success = False;
 829                 return 1;
 830         }
 831         return 0;
 832 }
 833
 834 static int tdb_copy(struct tdb_context *src, struct tdb_context *dst)
 835 {
 836         struct tdb_copy_data data;
 837         int count;
 838
 839         data.dst = dst;
 840         data.success = True;
 841
 842         count = tdb_traverse(src, traverse_copy_fn, (void *)(&data));
 843         if ((count < 0) || (data.success == False)) {
 844                 return -1;
 845         }
 846         return count;
 847 }
 848
 849 static int tdb_verify_basic(struct tdb_context *tdb)
 850 {
 851         return tdb_traverse(tdb, NULL, NULL);
 852 }
 853
 854 /* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
 855  */
 856 static int tdb_backup(TALLOC_CTX *ctx, const char *src_path,
 857                       const char *dst_path, int hash_size)
 858 {
 859         struct tdb_context *src_tdb = NULL;
 860         struct tdb_context *dst_tdb = NULL;
 861         char *tmp_path = NULL;
 862         struct stat st;
 863         int count1, count2;
 864         int saved_errno = 0;
 865         int ret = -1;
 866
 867         if (stat(src_path, &st) != 0) {
 868                 DEBUG(3, ("Could not stat '%s': %s\n", src_path,
 869                           strerror(errno)));
 870                 goto done;
 871         }
 872
 873         /* open old tdb RDWR - so we can lock it */
 874         src_tdb = tdb_open_log(src_path, 0, TDB_DEFAULT, O_RDWR, 0);
 875         if (src_tdb == NULL) {
 876                 DEBUG(3, ("Failed to open tdb '%s'\n", src_path));
 877                 goto done;
 878         }
 879
 880         if (tdb_lockall(src_tdb) != 0) {
 881                 DEBUG(3, ("Failed to lock tdb '%s'\n", src_path));
 882                 goto done;
 883         }
 884
 885         tmp_path = talloc_asprintf(ctx, "%s%s", dst_path, ".tmp");
 886         unlink(tmp_path);
 887         dst_tdb = tdb_open_log(tmp_path,
 888                                hash_size ? hash_size : tdb_hash_size(src_tdb),
 889                                TDB_DEFAULT, O_RDWR | O_CREAT | O_EXCL,
 890                                st.st_mode & 0777);
 891         if (dst_tdb == NULL) {
 892                 DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path,
 893                           strerror(errno)));
 894                 saved_errno = errno;
 895                 unlink(tmp_path);
 896                 goto done;
 897         }
 898
 899         count1 = tdb_copy(src_tdb, dst_tdb);
 900         if (count1 < 0) {
 901                 DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path,
 902                           strerror(errno)));
 903                 tdb_close(dst_tdb);
 904                 goto done;
 905         }
 906
 907         /* reopen ro and do basic verification */
 908         tdb_close(dst_tdb);
 909         dst_tdb = tdb_open_log(tmp_path, 0, TDB_DEFAULT, O_RDONLY, 0);
 910         if (!dst_tdb) {
 911                 DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path,
 912                           strerror(errno)));
 913                 goto done;
 914         }
 915         count2 = tdb_verify_basic(dst_tdb);
 916         if (count2 != count1) {
 917                 DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
 918                           src_path));
 919                 tdb_close(dst_tdb);
 920                 goto done;
 921         }
 922
 923         DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1));
 924
 925         /* make sure the new tdb has reached stable storage
 926          * then rename it to its destination */
 927         fsync(tdb_fd(dst_tdb));
 928         tdb_close(dst_tdb);
 929         unlink(dst_path);
 930         if (rename(tmp_path, dst_path) != 0) {
 931                 DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
 932                           tmp_path, dst_path, strerror(errno)));
 933                 goto done;
 934         }
 935
 936         /* success */
 937         ret = 0;
 938
 939 done:
 940         if (src_tdb != NULL) {
 941                 tdb_close(src_tdb);
 942         }
 943         if (tmp_path != NULL) {
 944                 unlink(tmp_path);
 945                 TALLOC_FREE(tmp_path);
 946         }
 947         if (saved_errno != 0) {
 948                 errno = saved_errno;
 949         }
 950         return ret;
 951 }
 952
 953 static int rename_file_with_suffix(TALLOC_CTX *ctx, const char *path,
 954                                    const char *suffix)
 955 {
 956         int ret = -1;
 957         char *dst_path;
 958
 959         dst_path = talloc_asprintf(ctx, "%s%s", path, suffix);
 960
 961         ret = (rename(path, dst_path) != 0);
 962
 963         if (ret == 0) {
 964                 DEBUG(5, ("moved '%s' to '%s'\n", path, dst_path));
 965         } else if (errno == ENOENT) {
 966                 DEBUG(3, ("file '%s' does not exist - so not moved\n", path));
 967                 ret = 0;
 968         } else {
 969                 DEBUG(3, ("error renaming %s to %s: %s\n", path, dst_path,
 970                           strerror(errno)));
 971         }
 972
 973         TALLOC_FREE(dst_path);
 974         return ret;
 975 }
 976
 977 /*
 978  * do a backup of a tdb, moving the destination out of the way first
 979  */
 980 static int tdb_backup_with_rotate(TALLOC_CTX *ctx, const char *src_path,
 981                                   const char *dst_path, int hash_size,
 982                                   const char *rotate_suffix,
 983                                   bool retry_norotate_if_nospc,
 984                                   bool rename_as_last_resort_if_nospc)
 985 {
 986         int ret;
 987
 988         rename_file_with_suffix(ctx, dst_path, rotate_suffix);
 989
 990         ret = tdb_backup(ctx, src_path, dst_path, hash_size);
 991
 992         if (ret != 0) {
 993                 DEBUG(10, ("backup of %s failed: %s\n", src_path, strerror(errno)));
 994         }
 995         if ((ret != 0) && (errno == ENOSPC) && retry_norotate_if_nospc)
 996         {
 997                 char *rotate_path = talloc_asprintf(ctx, "%s%s", dst_path,
 998                                                     rotate_suffix);
 999                 DEBUG(10, ("backup of %s failed due to lack of space\n",
1000                            src_path));
1001                 DEBUGADD(10, ("trying to free some space by removing rotated "
1002                               "dst %s\n", rotate_path));
1003                 if (unlink(rotate_path) == -1) {
1004                         DEBUG(10, ("unlink of %s failed: %s\n", rotate_path,
1005                                    strerror(errno)));
1006                 } else {
1007                         ret = tdb_backup(ctx, src_path, dst_path, hash_size);
1008                 }
1009                 TALLOC_FREE(rotate_path);
1010         }
1011
1012         if ((ret != 0) && (errno == ENOSPC) && rename_as_last_resort_if_nospc)
1013         {
1014                 DEBUG(10, ("backup of %s failed due to lack of space\n",
1015                            src_path));
1016                 DEBUGADD(10, ("using 'rename' as a last resort\n"));
1017                 ret = rename(src_path, dst_path);
1018         }
1019
1020         return ret;
1021 }
1022
1023 /*
1024  * validation function with backup handling:
1025  *
1026  *  - calls tdb_validate
1027  *  - if the tdb is ok, create a backup "name.bak", possibly moving
1028  *    existing backup to name.bak.old,
1029  *    return 0 (success) even if the backup fails
1030  *  - if the tdb is corrupt:
1031  *    - move the tdb to "name.corrupt"
1032  *    - check if there is valid backup.
1033  *      if so, restore the backup.
1034  *      if restore is successful, return 0 (success),
1035  *    - otherwise return -1 (failure)
1036  */
1037 int tdb_validate_and_backup(const char *tdb_path,
1038                             tdb_validate_data_func validate_fn)
1039 {
1040         int ret = -1;
1041         const char *backup_suffix = ".bak";
1042         const char *corrupt_suffix = ".corrupt";
1043         const char *rotate_suffix = ".old";
1044         char *tdb_path_backup;
1045         struct stat st;
1046         TALLOC_CTX *ctx = NULL;
1047
1048         ctx = talloc_new(NULL);
1049         if (ctx == NULL) {
1050                 DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
1051                 goto done;
1052         }
1053
1054         tdb_path_backup = talloc_asprintf(ctx, "%s%s", tdb_path, backup_suffix);
1055
1056         ret = tdb_validate_open(tdb_path, validate_fn);
1057
1058         if (ret == 0) {
1059                 DEBUG(1, ("tdb '%s' is valid\n", tdb_path));
1060                 ret = tdb_backup_with_rotate(ctx, tdb_path, tdb_path_backup, 0,
1061                                              rotate_suffix, True, False);
1062                 if (ret != 0) {
1063                         DEBUG(1, ("Error creating backup of tdb '%s'\n",
1064                                   tdb_path));
1065                         /* the actual validation was successful: */
1066                         ret = 0;
1067                 } else {
1068                         DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
1069                                   tdb_path_backup, tdb_path));
1070                 }
1071         } else {
1072                 DEBUG(1, ("tdb '%s' is invalid\n", tdb_path));
1073
1074                 ret =stat(tdb_path_backup, &st);
1075                 if (ret != 0) {
1076                         DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup,
1077                                   strerror(errno)));
1078                         DEBUG(1, ("No backup found.\n"));
1079                 } else {
1080                         DEBUG(1, ("backup '%s' found.\n", tdb_path_backup));
1081                         ret = tdb_validate_open(tdb_path_backup, validate_fn);
1082                         if (ret != 0) {
1083                                 DEBUG(1, ("Backup '%s' is invalid.\n",
1084                                           tdb_path_backup));
1085                         }
1086                 }
1087
1088                 if (ret != 0) {
1089                         int renamed = rename_file_with_suffix(ctx, tdb_path,
1090                                                               corrupt_suffix);
1091                         if (renamed != 0) {
1092                                 DEBUG(1, ("Error moving tdb to '%s%s'\n",
1093                                           tdb_path, corrupt_suffix));
1094                         } else {
1095                                 DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
1096                                           tdb_path, corrupt_suffix));
1097                         }
1098                         goto done;
1099                 }
1100
1101                 DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup));
1102                 ret = tdb_backup_with_rotate(ctx, tdb_path_backup, tdb_path, 0,
1103                                              corrupt_suffix, True, True);
1104                 if (ret != 0) {
1105                         DEBUG(1, ("Error restoring backup from '%s'\n",
1106                                   tdb_path_backup));
1107                 } else {
1108                         DEBUG(1, ("Restored tdb backup from '%s'\n",
1109                                   tdb_path_backup));
1110                 }
1111         }
1112
1113 done:
1114         TALLOC_FREE(ctx);
1115         return ret;
1116 }