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 /****************************************************************************
  33  Useful pair of routines for packing/unpacking data consisting of
  34  integers and strings.
  35 ****************************************************************************/
  36
  37 static size_t tdb_pack_va(uint8_t *buf, int bufsize, const char *fmt, va_list ap)
  38 {
  39         uint8_t bt;
  40         uint16_t w;
  41         uint32_t d;
  42         int i;
  43         void *p;
  44         int len = 0;
  45         char *s;
  46         char c;
  47         const char *fmt0 = fmt;
  48         int bufsize0 = bufsize;
  49         size_t to_write = 0;
  50         while (*fmt) {
  51                 switch ((c = *fmt++)) {
  52                 case 'b': /* unsigned 8-bit integer */
  53                         len = 1;
  54                         bt = (uint8_t)va_arg(ap, int);
  55                         if (bufsize && bufsize >= len)
  56                                 SSVAL(buf, 0, bt);
  57                         break;
  58                 case 'w': /* unsigned 16-bit integer */
  59                         len = 2;
  60                         w = (uint16_t)va_arg(ap, int);
  61                         if (bufsize && bufsize >= len)
  62                                 SSVAL(buf, 0, w);
  63                         break;
  64                 case 'd': /* signed 32-bit integer (standard int in most systems) */
  65                         len = 4;
  66                         d = va_arg(ap, uint32_t);
  67                         if (bufsize && bufsize >= len)
  68                                 SIVAL(buf, 0, d);
  69                         break;
  70                 case 'p': /* pointer */
  71                         len = 4;
  72                         p = va_arg(ap, void *);
  73                         d = p?1:0;
  74                         if (bufsize && bufsize >= len)
  75                                 SIVAL(buf, 0, d);
  76                         break;
  77                 case 'P': /* null-terminated string */
  78                 case 'f': /* null-terminated string */
  79                         s = va_arg(ap,char *);
  80                         if (s == NULL) {
  81                                 smb_panic("Invalid argument");
  82                         }
  83                         w = strlen(s);
  84                         len = w + 1;
  85                         if (bufsize && bufsize >= len)
  86                                 memcpy(buf, s, len);
  87                         break;
  88                 case 'B': /* fixed-length string */
  89                         i = va_arg(ap, int);
  90                         s = va_arg(ap, char *);
  91                         len = 4+i;
  92                         if (bufsize && bufsize >= len) {
  93                                 SIVAL(buf, 0, i);
  94                                 if (s != NULL) {
  95                                         memcpy(buf+4, s, i);
  96                                 }
  97                         }
  98                         break;
  99                 default:
 100                         DEBUG(0,("Unknown tdb_pack format %c in %s\n",
 101                                  c, fmt));
 102                         len = 0;
 103                         break;
 104                 }
 105
 106                 to_write += len;
 107                 if (bufsize > 0) {
 108                         bufsize -= len;
 109                         buf += len;
 110                 }
 111                 if (bufsize < 0)
 112                         bufsize = 0;
 113         }
 114
 115         DEBUG(18,("tdb_pack_va(%s, %d) -> %d\n",
 116                  fmt0, bufsize0, (int)to_write));
 117
 118         return to_write;
 119 }
 120
 121 size_t tdb_pack(uint8_t *buf, int bufsize, const char *fmt, ...)
 122 {
 123         va_list ap;
 124         size_t result;
 125
 126         va_start(ap, fmt);
 127         result = tdb_pack_va(buf, bufsize, fmt, ap);
 128         va_end(ap);
 129         return result;
 130 }
 131
 132 /****************************************************************************
 133  Useful pair of routines for packing/unpacking data consisting of
 134  integers and strings.
 135 ****************************************************************************/
 136
 137 int tdb_unpack(const uint8_t *buf, int in_bufsize, const char *fmt, ...)
 138 {
 139         va_list ap;
 140         uint8_t *bt;
 141         uint16_t *w;
 142         uint32_t *d;
 143         size_t bufsize = in_bufsize;
 144         size_t len;
 145         uint32_t *i;
 146         void **p;
 147         char *s, **b, **ps;
 148         char c;
 149         const uint8_t *buf0 = buf;
 150         const char *fmt0 = fmt;
 151
 152         va_start(ap, fmt);
 153
 154         while (*fmt) {
 155                 switch ((c=*fmt++)) {
 156                 case 'b': /* unsigned 8-bit integer */
 157                         len = 1;
 158                         bt = va_arg(ap, uint8_t *);
 159                         if (bufsize < len)
 160                                 goto no_space;
 161                         *bt = SVAL(buf, 0);
 162                         break;
 163                 case 'w': /* unsigned 16-bit integer */
 164                         len = 2;
 165                         w = va_arg(ap, uint16_t *);
 166                         if (bufsize < len)
 167                                 goto no_space;
 168                         *w = SVAL(buf, 0);
 169                         break;
 170                 case 'd': /* unsigned 32-bit integer (standard int in most systems) */
 171                         len = 4;
 172                         d = va_arg(ap, uint32_t *);
 173                         if (bufsize < len)
 174                                 goto no_space;
 175                         *d = IVAL(buf, 0);
 176                         break;
 177                 case 'p': /* pointer */
 178                         len = 4;
 179                         p = va_arg(ap, void **);
 180                         if (bufsize < len)
 181                                 goto no_space;
 182                         /*
 183                          * This isn't a real pointer - only a token (1 or 0)
 184                          * to mark the fact a pointer is present.
 185                          */
 186
 187                         *p = (void *)(IVAL(buf, 0) ? (void *)1 : NULL);
 188                         break;
 189                 case 'P': /* null-terminated string */
 190                         /* Return malloc'ed string. */
 191                         ps = va_arg(ap,char **);
 192                         len = strnlen((const char *)buf, bufsize) + 1;
 193                         if (bufsize < len)
 194                                 goto no_space;
 195                         if (ps != NULL) {
 196                                 *ps = SMB_STRDUP((const char *)buf);
 197                                 if (*ps == NULL) {
 198                                         goto no_space;
 199                                 }
 200                         }
 201                         break;
 202                 case 'f': /* null-terminated string */
 203                         s = va_arg(ap,char *);
 204                         len = strnlen((const char *)buf, bufsize) + 1;
 205                         if (bufsize < len || len > sizeof(fstring))
 206                                 goto no_space;
 207                         if (s != NULL) {
 208                                 memcpy(s, buf, len);
 209                         }
 210                         break;
 211                 case 'B': /* fixed-length string */
 212                         i = va_arg(ap, uint32_t *);
 213                         b = va_arg(ap, char **);
 214                         len = 4;
 215                         if (bufsize < len)
 216                                 goto no_space;
 217                         *i = IVAL(buf, 0);
 218                         if (! *i) {
 219                                 *b = NULL;
 220                                 break;
 221                         }
 222                         len += *i;
 223                         if (len < *i) {
 224                                 goto no_space;
 225                         }
 226                         if (bufsize < len)
 227                                 goto no_space;
 228                         if (b != NULL) {
 229                                 *b = (char *)SMB_MALLOC(*i);
 230                                 if (! *b)
 231                                         goto no_space;
 232                                 memcpy(*b, buf+4, *i);
 233                         }
 234                         break;
 235                 default:
 236                         DEBUG(0,("Unknown tdb_unpack format %c in %s\n",
 237                                  c, fmt));
 238
 239                         len = 0;
 240                         break;
 241                 }
 242
 243                 buf += len;
 244                 bufsize -= len;
 245         }
 246
 247         va_end(ap);
 248
 249         DEBUG(18,("tdb_unpack(%s, %d) -> %d\n",
 250                  fmt0, in_bufsize, (int)PTR_DIFF(buf, buf0)));
 251
 252         return PTR_DIFF(buf, buf0);
 253
 254  no_space:
 255         va_end(ap);
 256         return -1;
 257 }
 258
 259
 260 /****************************************************************************
 261  Log tdb messages via DEBUG().
 262 ****************************************************************************/
 263
 264 static void tdb_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
 265                     const char *format, ...) PRINTF_ATTRIBUTE(3,4);
 266
 267 static void tdb_log(TDB_CONTEXT *tdb, enum tdb_debug_level level, const char *format, ...)
 268 {
 269         va_list ap;
 270         char *ptr = NULL;
 271         int ret;
 272
 273         va_start(ap, format);
 274         ret = vasprintf(&ptr, format, ap);
 275         va_end(ap);
 276
 277         if ((ret == -1) || !*ptr)
 278                 return;
 279
 280         DEBUG((int)level, ("tdb(%s): %s", tdb_name(tdb) ? tdb_name(tdb) : "unnamed", ptr));
 281         SAFE_FREE(ptr);
 282 }
 283
 284 /****************************************************************************
 285  Like tdb_open() but also setup a logging function that redirects to
 286  the samba DEBUG() system.
 287 ****************************************************************************/
 288
 289 TDB_CONTEXT *tdb_open_log(const char *name, int hash_size, int tdb_flags,
 290                           int open_flags, mode_t mode)
 291 {
 292         TDB_CONTEXT *tdb;
 293         struct tdb_logging_context log_ctx = { .log_fn = tdb_log };
 294
 295         if (!lp_use_mmap())
 296                 tdb_flags |= TDB_NOMMAP;
 297
 298         if ((hash_size == 0) && (name != NULL)) {
 299                 const char *base = strrchr_m(name, '/');
 300                 if (base != NULL) {
 301                         base += 1;
 302                 }
 303                 else {
 304                         base = name;
 305                 }
 306                 hash_size = lp_parm_int(-1, "tdb_hashsize", base, 0);
 307         }
 308
 309         tdb = tdb_open_ex(name, hash_size, tdb_flags,
 310                           open_flags, mode, &log_ctx, NULL);
 311         if (!tdb)
 312                 return NULL;
 313
 314         return tdb;
 315 }
 316
 317 int tdb_data_cmp(TDB_DATA t1, TDB_DATA t2)
 318 {
 319         int ret;
 320         if (t1.dptr == NULL && t2.dptr != NULL) {
 321                 return -1;
 322         }
 323         if (t1.dptr != NULL && t2.dptr == NULL) {
 324                 return 1;
 325         }
 326         if (t1.dptr == t2.dptr) {
 327                 return NUMERIC_CMP(t1.dsize, t2.dsize);
 328         }
 329         ret = memcmp(t1.dptr, t2.dptr, MIN(t1.dsize, t2.dsize));
 330         if (ret == 0) {
 331                 return NUMERIC_CMP(t1.dsize, t2.dsize);
 332         }
 333         return ret;
 334 }
 335
 336 char *tdb_data_string(TALLOC_CTX *mem_ctx, TDB_DATA d)
 337 {
 338         int len;
 339         char *ret = NULL;
 340         cbuf *ost = cbuf_new(mem_ctx);
 341
 342         if (ost == NULL) {
 343                 return NULL;
 344         }
 345
 346         len = cbuf_printf(ost, "%zu:", d.dsize);
 347         if (len == -1) {
 348                 goto done;
 349         }
 350
 351         if (d.dptr == NULL) {
 352                 len = cbuf_puts(ost, "<NULL>", -1);
 353         } else {
 354                 len = cbuf_print_quoted(ost, (const char*)d.dptr, d.dsize);
 355         }
 356         if (len == -1) {
 357                 goto done;
 358         }
 359
 360         cbuf_swapptr(ost, &ret, 0);
 361         talloc_steal(mem_ctx, ret);
 362
 363 done:
 364         talloc_free(ost);
 365         return ret;
 366 }
 367
 368 char *tdb_data_dbg(TDB_DATA d)
 369 {
 370         return hex_encode_talloc(talloc_tos(), d.dptr, d.dsize);
 371 }
 372
 373 static sig_atomic_t gotalarm;
 374
 375 /***************************************************************
 376  Signal function to tell us we timed out.
 377 ****************************************************************/
 378
 379 static void gotalarm_sig(int signum)
 380 {
 381         gotalarm = 1;
 382 }
 383
 384 /****************************************************************************
 385  Lock a chain with timeout (in seconds).
 386 ****************************************************************************/
 387
 388 static int tdb_chainlock_with_timeout_internal( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout, int rw_type)
 389 {
 390         /* Allow tdb_chainlock to be interrupted by an alarm. */
 391         int ret;
 392         gotalarm = 0;
 393
 394         if (timeout) {
 395                 CatchSignal(SIGALRM, gotalarm_sig);
 396                 tdb_setalarm_sigptr(tdb, &gotalarm);
 397                 alarm(timeout);
 398         }
 399
 400         if (rw_type == F_RDLCK)
 401                 ret = tdb_chainlock_read(tdb, key);
 402         else
 403                 ret = tdb_chainlock(tdb, key);
 404
 405         if (timeout) {
 406                 alarm(0);
 407                 tdb_setalarm_sigptr(tdb, NULL);
 408                 CatchSignal(SIGALRM, SIG_IGN);
 409                 if (gotalarm && (ret != 0)) {
 410                         DEBUG(0,("tdb_chainlock_with_timeout_internal: alarm (%u) timed out for key %s in tdb %s\n",
 411                                 timeout, key.dptr, tdb_name(tdb)));
 412                         /* TODO: If we time out waiting for a lock, it might
 413                          * be nice to use F_GETLK to get the pid of the
 414                          * process currently holding the lock and print that
 415                          * as part of the debugging message. -- mbp */
 416                         return -1;
 417                 }
 418         }
 419
 420         return ret == 0 ? 0 : -1;
 421 }
 422
 423 /****************************************************************************
 424  Write lock a chain. Return non-zero if timeout or lock failed.
 425 ****************************************************************************/
 426
 427 int tdb_chainlock_with_timeout( TDB_CONTEXT *tdb, TDB_DATA key, unsigned int timeout)
 428 {
 429         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_WRLCK);
 430 }
 431
 432 int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval,
 433                                    int timeout)
 434 {
 435         TDB_DATA key = string_term_tdb_data(keyval);
 436
 437         return tdb_chainlock_with_timeout(tdb, key, timeout);
 438 }
 439
 440 /****************************************************************************
 441  Read lock a chain by string. Return non-zero if timeout or lock failed.
 442 ****************************************************************************/
 443
 444 int tdb_read_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, unsigned int timeout)
 445 {
 446         TDB_DATA key = string_term_tdb_data(keyval);
 447
 448         return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_RDLCK);
 449 }