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