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 #include "system/filesys.h"
  24 #include "util_tdb.h"
  25
  26 #undef malloc
  27 #undef realloc
  28 #undef calloc
  29 #undef strdup
  30
  31 /* these are little tdb utility functions that are meant to make
  32    dealing with a tdb database a little less cumbersome in Samba */
  33
  34 static SIG_ATOMIC_T gotalarm;
  35
  36 /***************************************************************
  37  Signal function to tell us we timed out.
  38 ****************************************************************/
  39
  40 static void gotalarm_sig(int signum)
  41 {
  42         gotalarm = 1;
  43 }
  44
  45 /****************************************************************************
  46  Lock a chain with timeout (in seconds).
  47 ****************************************************************************/
  48
  49 static int tdb_chainlock_with_timeout_internal( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout, int rw_type)
  50 {
  51         /* Allow tdb_chainlock to be interrupted by an alarm. */
  52         int ret;
  53         gotalarm = 0;
  54
  55         if (timeout) {
  56                 CatchSignal(SIGALRM, gotalarm_sig);
  57                 tdb_setalarm_sigptr(tdb, &gotalarm);
  58                 alarm(timeout);
  59         }
  60
  61         if (rw_type == F_RDLCK)
  62                 ret = tdb_chainlock_read(tdb, key);
  63         else
  64                 ret = tdb_chainlock(tdb, key);
  65
  66         if (timeout) {
  67                 alarm(0);
  68                 tdb_setalarm_sigptr(tdb, NULL);
  69                 CatchSignal(SIGALRM, SIG_IGN);
  70                 if (gotalarm && (ret == -1)) {
  71                         DEBUG(0,("tdb_chainlock_with_timeout_internal: alarm (%u) timed out for key %s in tdb %s\n",
  72                                 timeout, key.dptr, tdb_name(tdb)));
  73                         /* TODO: If we time out waiting for a lock, it might
  74                          * be nice to use F_GETLK to get the pid of the
  75                          * process currently holding the lock and print that
  76                          * as part of the debugging message. -- mbp */
  77                         return -1;
  78                 }
  79         }
  80
  81         return ret;
  82 }
  83
  84 /****************************************************************************
  85  Write lock a chain. Return -1 if timeout or lock failed.
  86 ****************************************************************************/
  87
  88 int tdb_chainlock_with_timeout( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout)
  89 {
  90         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_WRLCK);
  91 }
  92
  93 int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval,
  94                                    int timeout)
  95 {
  96         TDB_DATA key = string_term_tdb_data(keyval);
  97
  98         return tdb_chainlock_with_timeout(tdb, key, timeout);
  99 }
 100
 101 /****************************************************************************
 102  Read lock a chain by string. Return -1 if timeout or lock failed.
 103 ****************************************************************************/
 104
 105 int tdb_read_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, unsigned int timeout)
 106 {
 107         TDB_DATA key = string_term_tdb_data(keyval);
 108
 109         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_RDLCK);
 110 }
 111
 112
 113
 114
 115 int tdb_trans_store_bystring(TDB_CONTEXT *tdb, const char *keystr,
 116                              TDB_DATA data, int flags)
 117 {
 118         TDB_DATA key = string_term_tdb_data(keystr);
 119
 120         return tdb_trans_store(tdb, key, data, flags);
 121 }
 122
 123 /****************************************************************************
 124  Useful pair of routines for packing/unpacking data consisting of
 125  integers and strings.
 126 ****************************************************************************/
 127
 128 static size_t tdb_pack_va(uint8 *buf, int bufsize, const char *fmt, va_list ap)
 129 {
 130         uint8 bt;
 131         uint16 w;
 132         uint32 d;
 133         int i;
 134         void *p;
 135         int len;
 136         char *s;
 137         char c;
 138         uint8 *buf0 = buf;
 139         const char *fmt0 = fmt;
 140         int bufsize0 = bufsize;
 141
 142         while (*fmt) {
 143                 switch ((c = *fmt++)) {
 144                 case 'b': /* unsigned 8-bit integer */
 145                         len = 1;
 146                         bt = (uint8)va_arg(ap, int);
 147                         if (bufsize && bufsize >= len)
 148                                 SSVAL(buf, 0, bt);
 149                         break;
 150                 case 'w': /* unsigned 16-bit integer */
 151                         len = 2;
 152                         w = (uint16)va_arg(ap, int);
 153                         if (bufsize && bufsize >= len)
 154                                 SSVAL(buf, 0, w);
 155                         break;
 156                 case 'd': /* signed 32-bit integer (standard int in most systems) */
 157                         len = 4;
 158                         d = va_arg(ap, uint32);
 159                         if (bufsize && bufsize >= len)
 160                                 SIVAL(buf, 0, d);
 161                         break;
 162                 case 'p': /* pointer */
 163                         len = 4;
 164                         p = va_arg(ap, void *);
 165                         d = p?1:0;
 166                         if (bufsize && bufsize >= len)
 167                                 SIVAL(buf, 0, d);
 168                         break;
 169                 case 'P': /* null-terminated string */
 170                         s = va_arg(ap,char *);
 171                         w = strlen(s);
 172                         len = w + 1;
 173                         if (bufsize && bufsize >= len)
 174                                 memcpy(buf, s, len);
 175                         break;
 176                 case 'f': /* null-terminated string */
 177                         s = va_arg(ap,char *);
 178                         w = strlen(s);
 179                         len = w + 1;
 180                         if (bufsize && bufsize >= len)
 181                                 memcpy(buf, s, len);
 182                         break;
 183                 case 'B': /* fixed-length string */
 184                         i = va_arg(ap, int);
 185                         s = va_arg(ap, char *);
 186                         len = 4+i;
 187                         if (bufsize && bufsize >= len) {
 188                                 SIVAL(buf, 0, i);
 189                                 memcpy(buf+4, s, i);
 190                         }
 191                         break;
 192                 default:
 193                         DEBUG(0,("Unknown tdb_pack format %c in %s\n",
 194                                  c, fmt));
 195                         len = 0;
 196                         break;
 197                 }
 198
 199                 buf += len;
 200                 if (bufsize)
 201                         bufsize -= len;
 202                 if (bufsize < 0)
 203                         bufsize = 0;
 204         }
 205
 206         DEBUG(18,("tdb_pack_va(%s, %d) -> %d\n",
 207                  fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
 208
 209         return PTR_DIFF(buf, buf0);
 210 }
 211
 212 size_t tdb_pack(uint8 *buf, int bufsize, const char *fmt, ...)
 213 {
 214         va_list ap;
 215         size_t result;
 216
 217         va_start(ap, fmt);
 218         result = tdb_pack_va(buf, bufsize, fmt, ap);
 219         va_end(ap);
 220         return result;
 221 }
 222
 223 bool tdb_pack_append(TALLOC_CTX *mem_ctx, uint8 **buf, size_t *len,
 224                      const char *fmt, ...)
 225 {
 226         va_list ap;
 227         size_t len1, len2;
 228
 229         va_start(ap, fmt);
 230         len1 = tdb_pack_va(NULL, 0, fmt, ap);
 231         va_end(ap);
 232
 233         if (mem_ctx != NULL) {
 234                 *buf = TALLOC_REALLOC_ARRAY(mem_ctx, *buf, uint8,
 235                                             (*len) + len1);
 236         } else {
 237                 *buf = SMB_REALLOC_ARRAY(*buf, uint8, (*len) + len1);
 238         }
 239
 240         if (*buf == NULL) {
 241                 return False;
 242         }
 243
 244         va_start(ap, fmt);
 245         len2 = tdb_pack_va((*buf)+(*len), len1, fmt, ap);
 246         va_end(ap);
 247
 248         if (len1 != len2) {
 249                 return False;
 250         }
 251
 252         *len += len2;
 253
 254         return True;
 255 }
 256
 257 /****************************************************************************
 258  Useful pair of routines for packing/unpacking data consisting of
 259  integers and strings.
 260 ****************************************************************************/
 261
 262 int tdb_unpack(const uint8 *buf, int bufsize, const char *fmt, ...)
 263 {
 264         va_list ap;
 265         uint8 *bt;
 266         uint16 *w;
 267         uint32 *d;
 268         int len;
 269         int *i;
 270         void **p;
 271         char *s, **b, **ps;
 272         char c;
 273         const uint8 *buf0 = buf;
 274         const char *fmt0 = fmt;
 275         int bufsize0 = bufsize;
 276
 277         va_start(ap, fmt);
 278
 279         while (*fmt) {
 280                 switch ((c=*fmt++)) {
 281                 case 'b': /* unsigned 8-bit integer */
 282                         len = 1;
 283                         bt = va_arg(ap, uint8 *);
 284                         if (bufsize < len)
 285                                 goto no_space;
 286                         *bt = SVAL(buf, 0);
 287                         break;
 288                 case 'w': /* unsigned 16-bit integer */
 289                         len = 2;
 290                         w = va_arg(ap, uint16 *);
 291                         if (bufsize < len)
 292                                 goto no_space;
 293                         *w = SVAL(buf, 0);
 294                         break;
 295                 case 'd': /* signed 32-bit integer (standard int in most systems) */
 296                         len = 4;
 297                         d = va_arg(ap, uint32 *);
 298                         if (bufsize < len)
 299                                 goto no_space;
 300                         *d = IVAL(buf, 0);
 301                         break;
 302                 case 'p': /* pointer */
 303                         len = 4;
 304                         p = va_arg(ap, void **);
 305                         if (bufsize < len)
 306                                 goto no_space;
 307                         /*
 308                          * This isn't a real pointer - only a token (1 or 0)
 309                          * to mark the fact a pointer is present.
 310                          */
 311
 312                         *p = (void *)(IVAL(buf, 0) ? (void *)1 : NULL);
 313                         break;
 314                 case 'P': /* null-terminated string */
 315                         /* Return malloc'ed string. */
 316                         ps = va_arg(ap,char **);
 317                         len = strlen((const char *)buf) + 1;
 318                         *ps = SMB_STRDUP((const char *)buf);
 319                         break;
 320                 case 'f': /* null-terminated string */
 321                         s = va_arg(ap,char *);
 322                         len = strlen((const char *)buf) + 1;
 323                         if (bufsize < len || len > sizeof(fstring))
 324                                 goto no_space;
 325                         memcpy(s, buf, len);
 326                         break;
 327                 case 'B': /* fixed-length string */
 328                         i = va_arg(ap, int *);
 329                         b = va_arg(ap, char **);
 330                         len = 4;
 331                         if (bufsize < len)
 332                                 goto no_space;
 333                         *i = IVAL(buf, 0);
 334                         if (! *i) {
 335                                 *b = NULL;
 336                                 break;
 337                         }
 338                         len += *i;
 339                         if (bufsize < len)
 340                                 goto no_space;
 341                         *b = (char *)SMB_MALLOC(*i);
 342                         if (! *b)
 343                                 goto no_space;
 344                         memcpy(*b, buf+4, *i);
 345                         break;
 346                 default:
 347                         DEBUG(0,("Unknown tdb_unpack format %c in %s\n",
 348                                  c, fmt));
 349
 350                         len = 0;
 351                         break;
 352                 }
 353
 354                 buf += len;
 355                 bufsize -= len;
 356         }
 357
 358         va_end(ap);
 359
 360         DEBUG(18,("tdb_unpack(%s, %d) -> %d\n",
 361                  fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
 362
 363         return PTR_DIFF(buf, buf0);
 364
 365  no_space:
 366         va_end(ap);
 367         return -1;
 368 }
 369
 370
 371 /****************************************************************************
 372  Log tdb messages via DEBUG().
 373 ****************************************************************************/
 374
 375 static void tdb_log(TDB_CONTEXT *tdb, enum tdb_debug_level level, const char *format, ...)
 376 {
 377         va_list ap;
 378         char *ptr = NULL;
 379         int ret;
 380
 381         va_start(ap, format);
 382         ret = vasprintf(&ptr, format, ap);
 383         va_end(ap);
 384
 385         if ((ret == -1) || !*ptr)
 386                 return;
 387
 388         DEBUG((int)level, ("tdb(%s): %s", tdb_name(tdb) ? tdb_name(tdb) : "unnamed", ptr));
 389         SAFE_FREE(ptr);
 390 }
 391
 392 /****************************************************************************
 393  Like tdb_open() but also setup a logging function that redirects to
 394  the samba DEBUG() system.
 395 ****************************************************************************/
 396
 397 TDB_CONTEXT *tdb_open_log(const char *name, int hash_size, int tdb_flags,
 398                           int open_flags, mode_t mode)
 399 {
 400         TDB_CONTEXT *tdb;
 401         struct tdb_logging_context log_ctx;
 402
 403         if (!lp_use_mmap())
 404                 tdb_flags |= TDB_NOMMAP;
 405
 406         log_ctx.log_fn = tdb_log;
 407         log_ctx.log_private = NULL;
 408
 409         if ((hash_size == 0) && (name != NULL)) {
 410                 const char *base = strrchr_m(name, '/');
 411                 if (base != NULL) {
 412                         base += 1;
 413                 }
 414                 else {
 415                         base = name;
 416                 }
 417                 hash_size = lp_parm_int(-1, "tdb_hashsize", base, 0);
 418         }
 419
 420         tdb = tdb_open_ex(name, hash_size, tdb_flags,
 421                           open_flags, mode, &log_ctx, NULL);
 422         if (!tdb)
 423                 return NULL;
 424
 425         return tdb;
 426 }
 427
 428 /****************************************************************************
 429  tdb_store, wrapped in a transaction. This way we make sure that a process
 430  that dies within writing does not leave a corrupt tdb behind.
 431 ****************************************************************************/
 432
 433 int tdb_trans_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf,
 434                     int flag)
 435 {
 436         int res;
 437
 438         if ((res = tdb_transaction_start(tdb)) != 0) {
 439                 DEBUG(5, ("tdb_transaction_start failed\n"));
 440                 return res;
 441         }
 442
 443         if ((res = tdb_store(tdb, key, dbuf, flag)) != 0) {
 444                 DEBUG(10, ("tdb_store failed\n"));
 445                 if (tdb_transaction_cancel(tdb) != 0) {
 446                         smb_panic("Cancelling transaction failed");
 447                 }
 448                 return res;
 449         }
 450
 451         if ((res = tdb_transaction_commit(tdb)) != 0) {
 452                 DEBUG(5, ("tdb_transaction_commit failed\n"));
 453         }
 454
 455         return res;
 456 }
 457
 458 /****************************************************************************
 459  tdb_delete, wrapped in a transaction. This way we make sure that a process
 460  that dies within deleting does not leave a corrupt tdb behind.
 461 ****************************************************************************/
 462
 463 int tdb_trans_delete(struct tdb_context *tdb, TDB_DATA key)
 464 {
 465         int res;
 466
 467         if ((res = tdb_transaction_start(tdb)) != 0) {
 468                 DEBUG(5, ("tdb_transaction_start failed\n"));
 469                 return res;
 470         }
 471
 472         if ((res = tdb_delete(tdb, key)) != 0) {
 473                 DEBUG(10, ("tdb_delete failed\n"));
 474                 if (tdb_transaction_cancel(tdb) != 0) {
 475                         smb_panic("Cancelling transaction failed");
 476                 }
 477                 return res;
 478         }
 479
 480         if ((res = tdb_transaction_commit(tdb)) != 0) {
 481                 DEBUG(5, ("tdb_transaction_commit failed\n"));
 482         }
 483
 484         return res;
 485 }
 486
 487 NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err)
 488 {
 489         NTSTATUS result = NT_STATUS_INTERNAL_ERROR;
 490
 491         switch (err) {
 492         case TDB_SUCCESS:
 493                 result = NT_STATUS_OK;
 494                 break;
 495         case TDB_ERR_CORRUPT:
 496                 result = NT_STATUS_INTERNAL_DB_CORRUPTION;
 497                 break;
 498         case TDB_ERR_IO:
 499                 result = NT_STATUS_UNEXPECTED_IO_ERROR;
 500                 break;
 501         case TDB_ERR_OOM:
 502                 result = NT_STATUS_NO_MEMORY;
 503                 break;
 504         case TDB_ERR_EXISTS:
 505                 result = NT_STATUS_OBJECT_NAME_COLLISION;
 506                 break;
 507
 508         case TDB_ERR_LOCK:
 509                 /*
 510                  * TDB_ERR_LOCK is very broad, we could for example
 511                  * distinguish between fcntl locks and invalid lock
 512                  * sequences. So NT_STATUS_FILE_LOCK_CONFLICT is a
 513                  * compromise.
 514                  */
 515                 result = NT_STATUS_FILE_LOCK_CONFLICT;
 516                 break;
 517
 518         case TDB_ERR_NOLOCK:
 519         case TDB_ERR_LOCK_TIMEOUT:
 520                 /*
 521                  * These two ones in the enum are not actually used
 522                  */
 523                 result = NT_STATUS_FILE_LOCK_CONFLICT;
 524                 break;
 525         case TDB_ERR_NOEXIST:
 526                 result = NT_STATUS_NOT_FOUND;
 527                 break;
 528         case TDB_ERR_EINVAL:
 529                 result = NT_STATUS_INVALID_PARAMETER;
 530                 break;
 531         case TDB_ERR_RDONLY:
 532                 result = NT_STATUS_ACCESS_DENIED;
 533                 break;
 534         case TDB_ERR_NESTING:
 535                 result = NT_STATUS_INTERNAL_ERROR;
 536                 break;
 537         };
 538         return result;
 539 }
 540
 541 int tdb_data_cmp(TDB_DATA t1, TDB_DATA t2)
 542 {
 543         int ret;
 544         if (t1.dptr == NULL && t2.dptr != NULL) {
 545                 return -1;
 546         }
 547         if (t1.dptr != NULL && t2.dptr == NULL) {
 548                 return 1;
 549         }
 550         if (t1.dptr == t2.dptr) {
 551                 return t1.dsize - t2.dsize;
 552         }
 553         ret = memcmp(t1.dptr, t2.dptr, MIN(t1.dsize, t2.dsize));
 554         if (ret == 0) {
 555                 return t1.dsize - t2.dsize;
 556         }
 557         return ret;
 558 }