lib/util/util_tdb.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    tdb utility functions
   5
   6    Copyright (C) Andrew Tridgell 1992-2006
   7    Copyright (C) Volker Lendecke 2007-2011
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "system/filesys.h"
  25 #include "../lib/tdb/include/tdb.h"
  26 #include "../lib/util/util_tdb.h"
  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 /***************************************************************
  32  Make a TDB_DATA and keep the const warning in one place
  33 ****************************************************************/
  34
  35 TDB_DATA make_tdb_data(const uint8_t *dptr, size_t dsize)
  36 {
  37         TDB_DATA ret;
  38         ret.dptr = discard_const_p(uint8_t, dptr);
  39         ret.dsize = dsize;
  40         return ret;
  41 }
  42
  43 bool tdb_data_equal(TDB_DATA t1, TDB_DATA t2)
  44 {
  45         if (t1.dsize != t2.dsize) {
  46                 return false;
  47         }
  48         return (memcmp(t1.dptr, t2.dptr, t1.dsize) == 0);
  49 }
  50
  51 bool tdb_data_is_empty(TDB_DATA d)
  52 {
  53         return (d.dsize == 0) || (d.dptr == NULL);
  54 }
  55
  56 TDB_DATA string_tdb_data(const char *string)
  57 {
  58         return make_tdb_data((const uint8_t *)string, string ? strlen(string) : 0 );
  59 }
  60
  61 TDB_DATA string_term_tdb_data(const char *string)
  62 {
  63         return make_tdb_data((const uint8_t *)string, string ? strlen(string) + 1 : 0);
  64 }
  65
  66 /****************************************************************************
  67  Lock a chain by string. Return non-zero if lock failed.
  68 ****************************************************************************/
  69
  70 int tdb_lock_bystring(struct tdb_context *tdb, const char *keyval)
  71 {
  72         TDB_DATA key = string_term_tdb_data(keyval);
  73
  74         return tdb_chainlock(tdb, key);
  75 }
  76
  77 /****************************************************************************
  78  Unlock a chain by string.
  79 ****************************************************************************/
  80
  81 void tdb_unlock_bystring(struct tdb_context *tdb, const char *keyval)
  82 {
  83         TDB_DATA key = string_term_tdb_data(keyval);
  84
  85         tdb_chainunlock(tdb, key);
  86 }
  87
  88 /****************************************************************************
  89  Read lock a chain by string. Return non-zero if lock failed.
  90 ****************************************************************************/
  91
  92 int tdb_read_lock_bystring(struct tdb_context *tdb, const char *keyval)
  93 {
  94         TDB_DATA key = string_term_tdb_data(keyval);
  95
  96         return tdb_chainlock_read(tdb, key);
  97 }
  98
  99 /****************************************************************************
 100  Read unlock a chain by string.
 101 ****************************************************************************/
 102
 103 void tdb_read_unlock_bystring(struct tdb_context *tdb, const char *keyval)
 104 {
 105         TDB_DATA key = string_term_tdb_data(keyval);
 106
 107         tdb_chainunlock_read(tdb, key);
 108 }
 109
 110
 111 /****************************************************************************
 112  Fetch a int32_t value by a arbitrary blob key, return -1 if not found.
 113  Output is int32_t in native byte order.
 114 ****************************************************************************/
 115
 116 int32_t tdb_fetch_int32_byblob(struct tdb_context *tdb, TDB_DATA key)
 117 {
 118         TDB_DATA data;
 119         int32_t ret;
 120
 121         data = tdb_fetch(tdb, key);
 122         if (!data.dptr || data.dsize != sizeof(int32_t)) {
 123                 SAFE_FREE(data.dptr);
 124                 return -1;
 125         }
 126
 127         ret = IVAL(data.dptr,0);
 128         SAFE_FREE(data.dptr);
 129         return ret;
 130 }
 131
 132 /****************************************************************************
 133  Fetch a int32_t value by string key, return -1 if not found.
 134  Output is int32_t in native byte order.
 135 ****************************************************************************/
 136
 137 int32_t tdb_fetch_int32(struct tdb_context *tdb, const char *keystr)
 138 {
 139         return tdb_fetch_int32_byblob(tdb, string_term_tdb_data(keystr));
 140 }
 141
 142 /****************************************************************************
 143  Store a int32_t value by an arbitrary blob key, return 0 on success, -ve on failure.
 144  Input is int32_t in native byte order. Output in tdb is in little-endian.
 145 ****************************************************************************/
 146
 147 int tdb_store_int32_byblob(struct tdb_context *tdb, TDB_DATA key, int32_t v)
 148 {
 149         TDB_DATA data;
 150         int32_t v_store;
 151
 152         SIVAL(&v_store,0,v);
 153         data.dptr = (unsigned char *)&v_store;
 154         data.dsize = sizeof(int32_t);
 155
 156         return tdb_store(tdb, key, data, TDB_REPLACE);
 157 }
 158
 159 /****************************************************************************
 160  Store a int32_t value by string key, return 0 on success, -ve on failure.
 161  Input is int32_t in native byte order. Output in tdb is in little-endian.
 162 ****************************************************************************/
 163
 164 int tdb_store_int32(struct tdb_context *tdb, const char *keystr, int32_t v)
 165 {
 166         return tdb_store_int32_byblob(tdb, string_term_tdb_data(keystr), v);
 167 }
 168
 169 /****************************************************************************
 170  Fetch a uint32_t value by a arbitrary blob key, return false if not found.
 171  Output is uint32_t in native byte order.
 172 ****************************************************************************/
 173
 174 bool tdb_fetch_uint32_byblob(struct tdb_context *tdb, TDB_DATA key, uint32_t *value)
 175 {
 176         TDB_DATA data;
 177
 178         data = tdb_fetch(tdb, key);
 179         if (!data.dptr || data.dsize != sizeof(uint32_t)) {
 180                 SAFE_FREE(data.dptr);
 181                 return false;
 182         }
 183
 184         *value = IVAL(data.dptr,0);
 185         SAFE_FREE(data.dptr);
 186         return true;
 187 }
 188
 189 /****************************************************************************
 190  Fetch a uint32_t value by string key, return false if not found.
 191  Output is uint32_t in native byte order.
 192 ****************************************************************************/
 193
 194 bool tdb_fetch_uint32(struct tdb_context *tdb, const char *keystr, uint32_t *value)
 195 {
 196         return tdb_fetch_uint32_byblob(tdb, string_term_tdb_data(keystr), value);
 197 }
 198
 199 /****************************************************************************
 200  Store a uint32_t value by an arbitrary blob key, return true on success, false on failure.
 201  Input is uint32_t in native byte order. Output in tdb is in little-endian.
 202 ****************************************************************************/
 203
 204 bool tdb_store_uint32_byblob(struct tdb_context *tdb, TDB_DATA key, uint32_t value)
 205 {
 206         TDB_DATA data;
 207         uint32_t v_store;
 208         bool ret = true;
 209
 210         SIVAL(&v_store, 0, value);
 211         data.dptr = (unsigned char *)&v_store;
 212         data.dsize = sizeof(uint32_t);
 213
 214         if (tdb_store(tdb, key, data, TDB_REPLACE) != 0)
 215                 ret = false;
 216
 217         return ret;
 218 }
 219
 220 /****************************************************************************
 221  Store a uint32_t value by string key, return true on success, false on failure.
 222  Input is uint32_t in native byte order. Output in tdb is in little-endian.
 223 ****************************************************************************/
 224
 225 bool tdb_store_uint32(struct tdb_context *tdb, const char *keystr, uint32_t value)
 226 {
 227         return tdb_store_uint32_byblob(tdb, string_term_tdb_data(keystr), value);
 228 }
 229 /****************************************************************************
 230  Store a buffer by a null terminated string key.  Return 0 on success, -ve
 231  on failure.
 232 ****************************************************************************/
 233
 234 int tdb_store_bystring(struct tdb_context *tdb, const char *keystr, TDB_DATA data, int flags)
 235 {
 236         TDB_DATA key = string_term_tdb_data(keystr);
 237
 238         return tdb_store(tdb, key, data, flags);
 239 }
 240
 241 /****************************************************************************
 242  Fetch a buffer using a null terminated string key.  Don't forget to call
 243  free() on the result dptr.
 244 ****************************************************************************/
 245
 246 TDB_DATA tdb_fetch_bystring(struct tdb_context *tdb, const char *keystr)
 247 {
 248         TDB_DATA key = string_term_tdb_data(keystr);
 249
 250         return tdb_fetch(tdb, key);
 251 }
 252
 253 /****************************************************************************
 254  Delete an entry using a null terminated string key.
 255 ****************************************************************************/
 256
 257 int tdb_delete_bystring(struct tdb_context *tdb, const char *keystr)
 258 {
 259         TDB_DATA key = string_term_tdb_data(keystr);
 260
 261         return tdb_delete(tdb, key);
 262 }
 263
 264 /****************************************************************************
 265  Atomic integer change. Returns old value. To create, set initial value in *oldval.
 266 ****************************************************************************/
 267
 268 int32_t tdb_change_int32_atomic(struct tdb_context *tdb, const char *keystr, int32_t *oldval, int32_t change_val)
 269 {
 270         int32_t val;
 271         int32_t ret = -1;
 272
 273         if (tdb_lock_bystring(tdb, keystr) != 0)
 274                 return -1;
 275
 276         if ((val = tdb_fetch_int32(tdb, keystr)) == -1) {
 277                 /* The lookup failed */
 278                 if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
 279                         /* but not because it didn't exist */
 280                         goto err_out;
 281                 }
 282
 283                 /* Start with 'old' value */
 284                 val = *oldval;
 285
 286         } else {
 287                 /* It worked, set return value (oldval) to tdb data */
 288                 *oldval = val;
 289         }
 290
 291         /* Increment value for storage and return next time */
 292         val += change_val;
 293
 294         if (tdb_store_int32(tdb, keystr, val) != 0)
 295                 goto err_out;
 296
 297         ret = 0;
 298
 299   err_out:
 300
 301         tdb_unlock_bystring(tdb, keystr);
 302         return ret;
 303 }
 304
 305 static sig_atomic_t gotalarm;
 306
 307 /***************************************************************
 308  Signal function to tell us we timed out.
 309 ****************************************************************/
 310
 311 static void gotalarm_sig(int signum)
 312 {
 313         gotalarm = 1;
 314 }
 315
 316 /****************************************************************************
 317  Lock a chain with timeout (in seconds).
 318 ****************************************************************************/
 319
 320 static int tdb_chainlock_with_timeout_internal( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout, int rw_type)
 321 {
 322         /* Allow tdb_chainlock to be interrupted by an alarm. */
 323         int ret;
 324         gotalarm = 0;
 325
 326         if (timeout) {
 327                 CatchSignal(SIGALRM, gotalarm_sig);
 328                 tdb_setalarm_sigptr(tdb, &gotalarm);
 329                 alarm(timeout);
 330         }
 331
 332         if (rw_type == F_RDLCK)
 333                 ret = tdb_chainlock_read(tdb, key);
 334         else
 335                 ret = tdb_chainlock(tdb, key);
 336
 337         if (timeout) {
 338                 alarm(0);
 339                 tdb_setalarm_sigptr(tdb, NULL);
 340                 CatchSignal(SIGALRM, SIG_IGN);
 341                 if (gotalarm && (ret != 0)) {
 342                         DEBUG(0,("tdb_chainlock_with_timeout_internal: alarm (%u) timed out for key %s in tdb %s\n",
 343                                 timeout, key.dptr, tdb_name(tdb)));
 344                         /* TODO: If we time out waiting for a lock, it might
 345                          * be nice to use F_GETLK to get the pid of the
 346                          * process currently holding the lock and print that
 347                          * as part of the debugging message. -- mbp */
 348                         return -1;
 349                 }
 350         }
 351
 352         return ret == 0 ? 0 : -1;
 353 }
 354
 355 /****************************************************************************
 356  Write lock a chain. Return non-zero if timeout or lock failed.
 357 ****************************************************************************/
 358
 359 int tdb_chainlock_with_timeout( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout)
 360 {
 361         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_WRLCK);
 362 }
 363
 364 int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval,
 365                                    int timeout)
 366 {
 367         TDB_DATA key = string_term_tdb_data(keyval);
 368
 369         return tdb_chainlock_with_timeout(tdb, key, timeout);
 370 }
 371
 372 /****************************************************************************
 373  Read lock a chain by string. Return non-zero if timeout or lock failed.
 374 ****************************************************************************/
 375
 376 int tdb_read_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, unsigned int timeout)
 377 {
 378         TDB_DATA key = string_term_tdb_data(keyval);
 379
 380         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_RDLCK);
 381 }
 382
 383 /****************************************************************************
 384  Atomic unsigned integer change. Returns old value. To create, set initial value in *oldval.
 385 ****************************************************************************/
 386
 387 bool tdb_change_uint32_atomic(struct tdb_context *tdb, const char *keystr, uint32_t *oldval, uint32_t change_val)
 388 {
 389         uint32_t val;
 390         bool ret = false;
 391
 392         if (tdb_lock_bystring(tdb, keystr) != 0)
 393                 return false;
 394
 395         if (!tdb_fetch_uint32(tdb, keystr, &val)) {
 396                 /* It failed */
 397                 if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
 398                         /* and not because it didn't exist */
 399                         goto err_out;
 400                 }
 401
 402                 /* Start with 'old' value */
 403                 val = *oldval;
 404
 405         } else {
 406                 /* it worked, set return value (oldval) to tdb data */
 407                 *oldval = val;
 408
 409         }
 410
 411         /* get a new value to store */
 412         val += change_val;
 413
 414         if (!tdb_store_uint32(tdb, keystr, val))
 415                 goto err_out;
 416
 417         ret = true;
 418
 419   err_out:
 420
 421         tdb_unlock_bystring(tdb, keystr);
 422         return ret;
 423 }
 424
 425 /****************************************************************************
 426  Allow tdb_delete to be used as a tdb_traversal_fn.
 427 ****************************************************************************/
 428
 429 int tdb_traverse_delete_fn(struct tdb_context *the_tdb, TDB_DATA key, TDB_DATA dbuf,
 430                      void *state)
 431 {
 432     return tdb_delete(the_tdb, key);
 433 }
 434
 435 /****************************************************************************
 436  Return an NTSTATUS from a TDB_ERROR
 437 ****************************************************************************/
 438
 439 NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err)
 440 {
 441         NTSTATUS result = NT_STATUS_INTERNAL_ERROR;
 442
 443         switch (err) {
 444         case TDB_SUCCESS:
 445                 result = NT_STATUS_OK;
 446                 break;
 447         case TDB_ERR_CORRUPT:
 448                 result = NT_STATUS_INTERNAL_DB_CORRUPTION;
 449                 break;
 450         case TDB_ERR_IO:
 451                 result = NT_STATUS_UNEXPECTED_IO_ERROR;
 452                 break;
 453         case TDB_ERR_OOM:
 454                 result = NT_STATUS_NO_MEMORY;
 455                 break;
 456         case TDB_ERR_EXISTS:
 457                 result = NT_STATUS_OBJECT_NAME_COLLISION;
 458                 break;
 459
 460         case TDB_ERR_LOCK:
 461                 /*
 462                  * TDB_ERR_LOCK is very broad, we could for example
 463                  * distinguish between fcntl locks and invalid lock
 464                  * sequences. So NT_STATUS_FILE_LOCK_CONFLICT is a
 465                  * compromise.
 466                  */
 467                 result = NT_STATUS_FILE_LOCK_CONFLICT;
 468                 break;
 469
 470         case TDB_ERR_NOLOCK:
 471         case TDB_ERR_LOCK_TIMEOUT:
 472                 /*
 473                  * These two ones in the enum are not actually used
 474                  */
 475                 result = NT_STATUS_FILE_LOCK_CONFLICT;
 476                 break;
 477         case TDB_ERR_NOEXIST:
 478                 result = NT_STATUS_NOT_FOUND;
 479                 break;
 480         case TDB_ERR_EINVAL:
 481                 result = NT_STATUS_INVALID_PARAMETER;
 482                 break;
 483         case TDB_ERR_RDONLY:
 484                 result = NT_STATUS_ACCESS_DENIED;
 485                 break;
 486         case TDB_ERR_NESTING:
 487                 result = NT_STATUS_INTERNAL_ERROR;
 488                 break;
 489         };
 490         return result;
 491 }