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
   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 "tdb.h"
  24 #include "../lib/util/util_tdb.h"
  25
  26 /* these are little tdb utility functions that are meant to make
  27    dealing with a tdb database a little less cumbersome in Samba */
  28
  29 /***************************************************************
  30  Make a TDB_DATA and keep the const warning in one place
  31 ****************************************************************/
  32
  33 TDB_DATA make_tdb_data(const uint8_t *dptr, size_t dsize)
  34 {
  35         TDB_DATA ret;
  36         ret.dptr = discard_const_p(uint8_t, dptr);
  37         ret.dsize = dsize;
  38         return ret;
  39 }
  40
  41 TDB_DATA string_tdb_data(const char *string)
  42 {
  43         return make_tdb_data((const uint8_t *)string, string ? strlen(string) : 0 );
  44 }
  45
  46 TDB_DATA string_term_tdb_data(const char *string)
  47 {
  48         return make_tdb_data((const uint8_t *)string, string ? strlen(string) + 1 : 0);
  49 }
  50
  51 /****************************************************************************
  52  Lock a chain by string. Return -1 if lock failed.
  53 ****************************************************************************/
  54
  55 int tdb_lock_bystring(struct tdb_context *tdb, const char *keyval)
  56 {
  57         TDB_DATA key = string_term_tdb_data(keyval);
  58
  59         return tdb_chainlock(tdb, key);
  60 }
  61
  62 /****************************************************************************
  63  Unlock a chain by string.
  64 ****************************************************************************/
  65
  66 void tdb_unlock_bystring(struct tdb_context *tdb, const char *keyval)
  67 {
  68         TDB_DATA key = string_term_tdb_data(keyval);
  69
  70         tdb_chainunlock(tdb, key);
  71 }
  72
  73 /****************************************************************************
  74  Read lock a chain by string. Return -1 if lock failed.
  75 ****************************************************************************/
  76
  77 int tdb_read_lock_bystring(struct tdb_context *tdb, const char *keyval)
  78 {
  79         TDB_DATA key = string_term_tdb_data(keyval);
  80
  81         return tdb_chainlock_read(tdb, key);
  82 }
  83
  84 /****************************************************************************
  85  Read unlock a chain by string.
  86 ****************************************************************************/
  87
  88 void tdb_read_unlock_bystring(struct tdb_context *tdb, const char *keyval)
  89 {
  90         TDB_DATA key = string_term_tdb_data(keyval);
  91
  92         tdb_chainunlock_read(tdb, key);
  93 }
  94
  95
  96 /****************************************************************************
  97  Fetch a int32_t value by a arbitrary blob key, return -1 if not found.
  98  Output is int32_t in native byte order.
  99 ****************************************************************************/
 100
 101 int32_t tdb_fetch_int32_byblob(struct tdb_context *tdb, TDB_DATA key)
 102 {
 103         TDB_DATA data;
 104         int32_t ret;
 105
 106         data = tdb_fetch(tdb, key);
 107         if (!data.dptr || data.dsize != sizeof(int32_t)) {
 108                 SAFE_FREE(data.dptr);
 109                 return -1;
 110         }
 111
 112         ret = IVAL(data.dptr,0);
 113         SAFE_FREE(data.dptr);
 114         return ret;
 115 }
 116
 117 /****************************************************************************
 118  Fetch a int32_t value by string key, return -1 if not found.
 119  Output is int32_t in native byte order.
 120 ****************************************************************************/
 121
 122 int32_t tdb_fetch_int32(struct tdb_context *tdb, const char *keystr)
 123 {
 124         return tdb_fetch_int32_byblob(tdb, string_term_tdb_data(keystr));
 125 }
 126
 127 /****************************************************************************
 128  Store a int32_t value by an arbitary blob key, return 0 on success, -1 on failure.
 129  Input is int32_t in native byte order. Output in tdb is in little-endian.
 130 ****************************************************************************/
 131
 132 int tdb_store_int32_byblob(struct tdb_context *tdb, TDB_DATA key, int32_t v)
 133 {
 134         TDB_DATA data;
 135         int32_t v_store;
 136
 137         SIVAL(&v_store,0,v);
 138         data.dptr = (unsigned char *)&v_store;
 139         data.dsize = sizeof(int32_t);
 140
 141         return tdb_store(tdb, key, data, TDB_REPLACE);
 142 }
 143
 144 /****************************************************************************
 145  Store a int32_t value by string key, return 0 on success, -1 on failure.
 146  Input is int32_t in native byte order. Output in tdb is in little-endian.
 147 ****************************************************************************/
 148
 149 int tdb_store_int32(struct tdb_context *tdb, const char *keystr, int32_t v)
 150 {
 151         return tdb_store_int32_byblob(tdb, string_term_tdb_data(keystr), v);
 152 }
 153
 154 /****************************************************************************
 155  Fetch a uint32_t value by a arbitrary blob key, return false if not found.
 156  Output is uint32_t in native byte order.
 157 ****************************************************************************/
 158
 159 bool tdb_fetch_uint32_byblob(struct tdb_context *tdb, TDB_DATA key, uint32_t *value)
 160 {
 161         TDB_DATA data;
 162
 163         data = tdb_fetch(tdb, key);
 164         if (!data.dptr || data.dsize != sizeof(uint32_t)) {
 165                 SAFE_FREE(data.dptr);
 166                 return false;
 167         }
 168
 169         *value = IVAL(data.dptr,0);
 170         SAFE_FREE(data.dptr);
 171         return true;
 172 }
 173
 174 /****************************************************************************
 175  Fetch a uint32_t value by string key, return false if not found.
 176  Output is uint32_t in native byte order.
 177 ****************************************************************************/
 178
 179 bool tdb_fetch_uint32(struct tdb_context *tdb, const char *keystr, uint32_t *value)
 180 {
 181         return tdb_fetch_uint32_byblob(tdb, string_term_tdb_data(keystr), value);
 182 }
 183
 184 /****************************************************************************
 185  Store a uint32_t value by an arbitary blob key, return 0 on success, -1 on failure.
 186  Input is uint32_t in native byte order. Output in tdb is in little-endian.
 187 ****************************************************************************/
 188
 189 bool tdb_store_uint32_byblob(struct tdb_context *tdb, TDB_DATA key, uint32_t value)
 190 {
 191         TDB_DATA data;
 192         uint32_t v_store;
 193         bool ret = true;
 194
 195         SIVAL(&v_store, 0, value);
 196         data.dptr = (unsigned char *)&v_store;
 197         data.dsize = sizeof(uint32_t);
 198
 199         if (tdb_store(tdb, key, data, TDB_REPLACE) == -1)
 200                 ret = false;
 201
 202         return ret;
 203 }
 204
 205 /****************************************************************************
 206  Store a uint32_t value by string key, return 0 on success, -1 on failure.
 207  Input is uint32_t in native byte order. Output in tdb is in little-endian.
 208 ****************************************************************************/
 209
 210 bool tdb_store_uint32(struct tdb_context *tdb, const char *keystr, uint32_t value)
 211 {
 212         return tdb_store_uint32_byblob(tdb, string_term_tdb_data(keystr), value);
 213 }
 214 /****************************************************************************
 215  Store a buffer by a null terminated string key.  Return 0 on success, -1
 216  on failure.
 217 ****************************************************************************/
 218
 219 int tdb_store_bystring(struct tdb_context *tdb, const char *keystr, TDB_DATA data, int flags)
 220 {
 221         TDB_DATA key = string_term_tdb_data(keystr);
 222
 223         return tdb_store(tdb, key, data, flags);
 224 }
 225
 226 /****************************************************************************
 227  Fetch a buffer using a null terminated string key.  Don't forget to call
 228  free() on the result dptr.
 229 ****************************************************************************/
 230
 231 TDB_DATA tdb_fetch_bystring(struct tdb_context *tdb, const char *keystr)
 232 {
 233         TDB_DATA key = string_term_tdb_data(keystr);
 234
 235         return tdb_fetch(tdb, key);
 236 }
 237
 238 /****************************************************************************
 239  Delete an entry using a null terminated string key.
 240 ****************************************************************************/
 241
 242 int tdb_delete_bystring(struct tdb_context *tdb, const char *keystr)
 243 {
 244         TDB_DATA key = string_term_tdb_data(keystr);
 245
 246         return tdb_delete(tdb, key);
 247 }
 248
 249 /****************************************************************************
 250  Atomic integer change. Returns old value. To create, set initial value in *oldval.
 251 ****************************************************************************/
 252
 253 int32_t tdb_change_int32_atomic(struct tdb_context *tdb, const char *keystr, int32_t *oldval, int32_t change_val)
 254 {
 255         int32_t val;
 256         int32_t ret = -1;
 257
 258         if (tdb_lock_bystring(tdb, keystr) == -1)
 259                 return -1;
 260
 261         if ((val = tdb_fetch_int32(tdb, keystr)) == -1) {
 262                 /* The lookup failed */
 263                 if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
 264                         /* but not because it didn't exist */
 265                         goto err_out;
 266                 }
 267
 268                 /* Start with 'old' value */
 269                 val = *oldval;
 270
 271         } else {
 272                 /* It worked, set return value (oldval) to tdb data */
 273                 *oldval = val;
 274         }
 275
 276         /* Increment value for storage and return next time */
 277         val += change_val;
 278
 279         if (tdb_store_int32(tdb, keystr, val) == -1)
 280                 goto err_out;
 281
 282         ret = 0;
 283
 284   err_out:
 285
 286         tdb_unlock_bystring(tdb, keystr);
 287         return ret;
 288 }
 289
 290 /****************************************************************************
 291  Atomic unsigned integer change. Returns old value. To create, set initial value in *oldval.
 292 ****************************************************************************/
 293
 294 bool tdb_change_uint32_atomic(struct tdb_context *tdb, const char *keystr, uint32_t *oldval, uint32_t change_val)
 295 {
 296         uint32_t val;
 297         bool ret = false;
 298
 299         if (tdb_lock_bystring(tdb, keystr) == -1)
 300                 return false;
 301
 302         if (!tdb_fetch_uint32(tdb, keystr, &val)) {
 303                 /* It failed */
 304                 if (tdb_error(tdb) != TDB_ERR_NOEXIST) {
 305                         /* and not because it didn't exist */
 306                         goto err_out;
 307                 }
 308
 309                 /* Start with 'old' value */
 310                 val = *oldval;
 311
 312         } else {
 313                 /* it worked, set return value (oldval) to tdb data */
 314                 *oldval = val;
 315
 316         }
 317
 318         /* get a new value to store */
 319         val += change_val;
 320
 321         if (!tdb_store_uint32(tdb, keystr, val))
 322                 goto err_out;
 323
 324         ret = true;
 325
 326   err_out:
 327
 328         tdb_unlock_bystring(tdb, keystr);
 329         return ret;
 330 }
 331
 332 /****************************************************************************
 333  Allow tdb_delete to be used as a tdb_traversal_fn.
 334 ****************************************************************************/
 335
 336 int tdb_traverse_delete_fn(struct tdb_context *the_tdb, TDB_DATA key, TDB_DATA dbuf,
 337                      void *state)
 338 {
 339     return tdb_delete(the_tdb, key);
 340 }