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