lib/tdb2/tdb.c

   1 #include "private.h"
   2 #ifndef _SAMBA_BUILD_
   3 #include <ccan/asprintf/asprintf.h>
   4 #include <stdarg.h>
   5 #endif
   6
   7 static enum TDB_ERROR update_rec_hdr(struct tdb_context *tdb,
   8                                      tdb_off_t off,
   9                                      tdb_len_t keylen,
  10                                      tdb_len_t datalen,
  11                                      struct tdb_used_record *rec,
  12                                      uint64_t h)
  13 {
  14         uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
  15         enum TDB_ERROR ecode;
  16
  17         ecode = set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
  18                            keylen + dataroom, h);
  19         if (ecode == TDB_SUCCESS) {
  20                 ecode = tdb_write_convert(tdb, off, rec, sizeof(*rec));
  21         }
  22         return ecode;
  23 }
  24
  25 static enum TDB_ERROR replace_data(struct tdb_context *tdb,
  26                                    struct hash_info *h,
  27                                    struct tdb_data key, struct tdb_data dbuf,
  28                                    tdb_off_t old_off, tdb_len_t old_room,
  29                                    bool growing)
  30 {
  31         tdb_off_t new_off;
  32         enum TDB_ERROR ecode;
  33
  34         /* Allocate a new record. */
  35         new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
  36                         growing);
  37         if (TDB_OFF_IS_ERR(new_off)) {
  38                 return new_off;
  39         }
  40
  41         /* We didn't like the existing one: remove it. */
  42         if (old_off) {
  43                 tdb->stats.frees++;
  44                 ecode = add_free_record(tdb, old_off,
  45                                         sizeof(struct tdb_used_record)
  46                                         + key.dsize + old_room,
  47                                         TDB_LOCK_WAIT, true);
  48                 if (ecode == TDB_SUCCESS)
  49                         ecode = replace_in_hash(tdb, h, new_off);
  50         } else {
  51                 ecode = add_to_hash(tdb, h, new_off);
  52         }
  53         if (ecode != TDB_SUCCESS) {
  54                 return ecode;
  55         }
  56
  57         new_off += sizeof(struct tdb_used_record);
  58         ecode = tdb->methods->twrite(tdb, new_off, key.dptr, key.dsize);
  59         if (ecode != TDB_SUCCESS) {
  60                 return ecode;
  61         }
  62
  63         new_off += key.dsize;
  64         ecode = tdb->methods->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize);
  65         if (ecode != TDB_SUCCESS) {
  66                 return ecode;
  67         }
  68
  69         if (tdb->flags & TDB_SEQNUM)
  70                 tdb_inc_seqnum(tdb);
  71
  72         return TDB_SUCCESS;
  73 }
  74
  75 static enum TDB_ERROR update_data(struct tdb_context *tdb,
  76                                   tdb_off_t off,
  77                                   struct tdb_data dbuf,
  78                                   tdb_len_t extra)
  79 {
  80         enum TDB_ERROR ecode;
  81
  82         ecode = tdb->methods->twrite(tdb, off, dbuf.dptr, dbuf.dsize);
  83         if (ecode == TDB_SUCCESS && extra) {
  84                 /* Put a zero in; future versions may append other data. */
  85                 ecode = tdb->methods->twrite(tdb, off + dbuf.dsize, "", 1);
  86         }
  87         if (tdb->flags & TDB_SEQNUM)
  88                 tdb_inc_seqnum(tdb);
  89
  90         return ecode;
  91 }
  92
  93 enum TDB_ERROR tdb_store(struct tdb_context *tdb,
  94                          struct tdb_data key, struct tdb_data dbuf, int flag)
  95 {
  96         struct hash_info h;
  97         tdb_off_t off;
  98         tdb_len_t old_room = 0;
  99         struct tdb_used_record rec;
 100         enum TDB_ERROR ecode;
 101
 102         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 103         if (TDB_OFF_IS_ERR(off)) {
 104                 return tdb->last_error = off;
 105         }
 106
 107         /* Now we have lock on this hash bucket. */
 108         if (flag == TDB_INSERT) {
 109                 if (off) {
 110                         ecode = TDB_ERR_EXISTS;
 111                         goto out;
 112                 }
 113         } else {
 114                 if (off) {
 115                         old_room = rec_data_length(&rec)
 116                                 + rec_extra_padding(&rec);
 117                         if (old_room >= dbuf.dsize) {
 118                                 /* Can modify in-place.  Easy! */
 119                                 ecode = update_rec_hdr(tdb, off,
 120                                                        key.dsize, dbuf.dsize,
 121                                                        &rec, h.h);
 122                                 if (ecode != TDB_SUCCESS) {
 123                                         goto out;
 124                                 }
 125                                 ecode = update_data(tdb,
 126                                                     off + sizeof(rec)
 127                                                     + key.dsize, dbuf,
 128                                                     old_room - dbuf.dsize);
 129                                 if (ecode != TDB_SUCCESS) {
 130                                         goto out;
 131                                 }
 132                                 tdb_unlock_hashes(tdb, h.hlock_start,
 133                                                   h.hlock_range, F_WRLCK);
 134                                 return tdb->last_error = TDB_SUCCESS;
 135                         }
 136                 } else {
 137                         if (flag == TDB_MODIFY) {
 138                                 /* if the record doesn't exist and we
 139                                    are in TDB_MODIFY mode then we should fail
 140                                    the store */
 141                                 ecode = TDB_ERR_NOEXIST;
 142                                 goto out;
 143                         }
 144                 }
 145         }
 146
 147         /* If we didn't use the old record, this implies we're growing. */
 148         ecode = replace_data(tdb, &h, key, dbuf, off, old_room, off);
 149 out:
 150         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 151         return tdb->last_error = ecode;
 152 }
 153
 154 enum TDB_ERROR tdb_append(struct tdb_context *tdb,
 155                           struct tdb_data key, struct tdb_data dbuf)
 156 {
 157         struct hash_info h;
 158         tdb_off_t off;
 159         struct tdb_used_record rec;
 160         tdb_len_t old_room = 0, old_dlen;
 161         unsigned char *newdata;
 162         struct tdb_data new_dbuf;
 163         enum TDB_ERROR ecode;
 164
 165         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 166         if (TDB_OFF_IS_ERR(off)) {
 167                 return tdb->last_error = off;
 168         }
 169
 170         if (off) {
 171                 old_dlen = rec_data_length(&rec);
 172                 old_room = old_dlen + rec_extra_padding(&rec);
 173
 174                 /* Fast path: can append in place. */
 175                 if (rec_extra_padding(&rec) >= dbuf.dsize) {
 176                         ecode = update_rec_hdr(tdb, off, key.dsize,
 177                                                old_dlen + dbuf.dsize, &rec,
 178                                                h.h);
 179                         if (ecode != TDB_SUCCESS) {
 180                                 goto out;
 181                         }
 182
 183                         off += sizeof(rec) + key.dsize + old_dlen;
 184                         ecode = update_data(tdb, off, dbuf,
 185                                             rec_extra_padding(&rec));
 186                         goto out;
 187                 }
 188
 189                 /* Slow path. */
 190                 newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
 191                 if (!newdata) {
 192                         ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
 193                                            "tdb_append:"
 194                                            " failed to allocate %zu bytes",
 195                                            (size_t)(key.dsize + old_dlen
 196                                                     + dbuf.dsize));
 197                         goto out;
 198                 }
 199                 ecode = tdb->methods->tread(tdb, off + sizeof(rec) + key.dsize,
 200                                             newdata, old_dlen);
 201                 if (ecode != TDB_SUCCESS) {
 202                         goto out_free_newdata;
 203                 }
 204                 memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
 205                 new_dbuf.dptr = newdata;
 206                 new_dbuf.dsize = old_dlen + dbuf.dsize;
 207         } else {
 208                 newdata = NULL;
 209                 new_dbuf = dbuf;
 210         }
 211
 212         /* If they're using tdb_append(), it implies they're growing record. */
 213         ecode = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
 214
 215 out_free_newdata:
 216         free(newdata);
 217 out:
 218         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 219         return tdb->last_error = ecode;
 220 }
 221
 222 enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
 223                          struct tdb_data *data)
 224 {
 225         tdb_off_t off;
 226         struct tdb_used_record rec;
 227         struct hash_info h;
 228         enum TDB_ERROR ecode;
 229
 230         off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
 231         if (TDB_OFF_IS_ERR(off)) {
 232                 return tdb->last_error = off;
 233         }
 234
 235         if (!off) {
 236                 ecode = TDB_ERR_NOEXIST;
 237         } else {
 238                 data->dsize = rec_data_length(&rec);
 239                 data->dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
 240                                             data->dsize);
 241                 if (TDB_PTR_IS_ERR(data->dptr)) {
 242                         ecode = TDB_PTR_ERR(data->dptr);
 243                 } else
 244                         ecode = TDB_SUCCESS;
 245         }
 246
 247         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 248         return tdb->last_error = ecode;
 249 }
 250
 251 bool tdb_exists(struct tdb_context *tdb, TDB_DATA key)
 252 {
 253         tdb_off_t off;
 254         struct tdb_used_record rec;
 255         struct hash_info h;
 256
 257         off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
 258         if (TDB_OFF_IS_ERR(off)) {
 259                 tdb->last_error = off;
 260                 return false;
 261         }
 262         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 263
 264         tdb->last_error = TDB_SUCCESS;
 265         return off ? true : false;
 266 }
 267
 268 enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 269 {
 270         tdb_off_t off;
 271         struct tdb_used_record rec;
 272         struct hash_info h;
 273         enum TDB_ERROR ecode;
 274
 275         off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
 276         if (TDB_OFF_IS_ERR(off)) {
 277                 return tdb->last_error = off;
 278         }
 279
 280         if (!off) {
 281                 ecode = TDB_ERR_NOEXIST;
 282                 goto unlock;
 283         }
 284
 285         ecode = delete_from_hash(tdb, &h);
 286         if (ecode != TDB_SUCCESS) {
 287                 goto unlock;
 288         }
 289
 290         /* Free the deleted entry. */
 291         tdb->stats.frees++;
 292         ecode = add_free_record(tdb, off,
 293                                 sizeof(struct tdb_used_record)
 294                                 + rec_key_length(&rec)
 295                                 + rec_data_length(&rec)
 296                                 + rec_extra_padding(&rec),
 297                                 TDB_LOCK_WAIT, true);
 298
 299         if (tdb->flags & TDB_SEQNUM)
 300                 tdb_inc_seqnum(tdb);
 301
 302 unlock:
 303         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
 304         return tdb->last_error = ecode;
 305 }
 306
 307 unsigned int tdb_get_flags(struct tdb_context *tdb)
 308 {
 309         return tdb->flags;
 310 }
 311
 312 void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
 313 {
 314         if (tdb->flags & TDB_INTERNAL) {
 315                 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
 316                                              TDB_LOG_USE_ERROR,
 317                                              "tdb_add_flag: internal db");
 318                 return;
 319         }
 320         switch (flag) {
 321         case TDB_NOLOCK:
 322                 tdb->flags |= TDB_NOLOCK;
 323                 break;
 324         case TDB_NOMMAP:
 325                 tdb->flags |= TDB_NOMMAP;
 326                 tdb_munmap(tdb->file);
 327                 break;
 328         case TDB_NOSYNC:
 329                 tdb->flags |= TDB_NOSYNC;
 330                 break;
 331         case TDB_SEQNUM:
 332                 tdb->flags |= TDB_SEQNUM;
 333                 break;
 334         case TDB_ALLOW_NESTING:
 335                 tdb->flags |= TDB_ALLOW_NESTING;
 336                 break;
 337         default:
 338                 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
 339                                              TDB_LOG_USE_ERROR,
 340                                              "tdb_add_flag: Unknown flag %u",
 341                                              flag);
 342         }
 343 }
 344
 345 void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
 346 {
 347         if (tdb->flags & TDB_INTERNAL) {
 348                 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
 349                                              TDB_LOG_USE_ERROR,
 350                                              "tdb_remove_flag: internal db");
 351                 return;
 352         }
 353         switch (flag) {
 354         case TDB_NOLOCK:
 355                 tdb->flags &= ~TDB_NOLOCK;
 356                 break;
 357         case TDB_NOMMAP:
 358                 tdb->flags &= ~TDB_NOMMAP;
 359                 tdb_mmap(tdb);
 360                 break;
 361         case TDB_NOSYNC:
 362                 tdb->flags &= ~TDB_NOSYNC;
 363                 break;
 364         case TDB_SEQNUM:
 365                 tdb->flags &= ~TDB_SEQNUM;
 366                 break;
 367         case TDB_ALLOW_NESTING:
 368                 tdb->flags &= ~TDB_ALLOW_NESTING;
 369                 break;
 370         default:
 371                 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
 372                                              TDB_LOG_USE_ERROR,
 373                                              "tdb_remove_flag: Unknown flag %u",
 374                                              flag);
 375         }
 376 }
 377
 378 const char *tdb_errorstr(enum TDB_ERROR ecode)
 379 {
 380         /* Gcc warns if you miss a case in the switch, so use that. */
 381         switch (ecode) {
 382         case TDB_SUCCESS: return "Success";
 383         case TDB_ERR_CORRUPT: return "Corrupt database";
 384         case TDB_ERR_IO: return "IO Error";
 385         case TDB_ERR_LOCK: return "Locking error";
 386         case TDB_ERR_OOM: return "Out of memory";
 387         case TDB_ERR_EXISTS: return "Record exists";
 388         case TDB_ERR_EINVAL: return "Invalid parameter";
 389         case TDB_ERR_NOEXIST: return "Record does not exist";
 390         case TDB_ERR_RDONLY: return "write not permitted";
 391         }
 392         return "Invalid error code";
 393 }
 394
 395 enum TDB_ERROR tdb_error(struct tdb_context *tdb)
 396 {
 397         return tdb->last_error;
 398 }
 399
 400 enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
 401                                enum TDB_ERROR ecode,
 402                                enum tdb_log_level level,
 403                                const char *fmt, ...)
 404 {
 405         char *message;
 406         va_list ap;
 407         size_t len;
 408         /* tdb_open paths care about errno, so save it. */
 409         int saved_errno = errno;
 410
 411         if (!tdb->log_fn)
 412                 return ecode;
 413
 414         va_start(ap, fmt);
 415         len = vasprintf(&message, fmt, ap);
 416         va_end(ap);
 417
 418         if (len < 0) {
 419                 tdb->log_fn(tdb, TDB_LOG_ERROR,
 420                             "out of memory formatting message:", tdb->log_data);
 421                 tdb->log_fn(tdb, level, fmt, tdb->log_data);
 422         } else {
 423                 tdb->log_fn(tdb, level, message, tdb->log_data);
 424                 free(message);
 425         }
 426         errno = saved_errno;
 427         return ecode;
 428 }
 429
 430 enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
 431                                  TDB_DATA key,
 432                                  enum TDB_ERROR (*parse)(TDB_DATA k,
 433                                                          TDB_DATA d,
 434                                                          void *data),
 435                                  void *data)
 436 {
 437         tdb_off_t off;
 438         struct tdb_used_record rec;
 439         struct hash_info h;
 440         enum TDB_ERROR ecode;
 441
 442         off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
 443         if (TDB_OFF_IS_ERR(off)) {
 444                 return tdb->last_error = off;
 445         }
 446
 447         if (!off) {
 448                 ecode = TDB_ERR_NOEXIST;
 449         } else {
 450                 const void *dptr;
 451                 dptr = tdb_access_read(tdb, off + sizeof(rec) + key.dsize,
 452                                        rec_data_length(&rec), false);
 453                 if (TDB_PTR_IS_ERR(dptr)) {
 454                         ecode = TDB_PTR_ERR(dptr);
 455                 } else {
 456                         TDB_DATA d = tdb_mkdata(dptr, rec_data_length(&rec));
 457
 458                         ecode = parse(key, d, data);
 459                         tdb_access_release(tdb, dptr);
 460                 }
 461         }
 462
 463         tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 464         return tdb->last_error = ecode;
 465 }
 466
 467 const char *tdb_name(const struct tdb_context *tdb)
 468 {
 469         return tdb->name;
 470 }
 471
 472 int64_t tdb_get_seqnum(struct tdb_context *tdb)
 473 {
 474         tdb_off_t off = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
 475         if (TDB_OFF_IS_ERR(off))
 476                 tdb->last_error = off;
 477         else
 478                 tdb->last_error = TDB_SUCCESS;
 479         return off;
 480 }
 481
 482
 483 int tdb_fd(const struct tdb_context *tdb)
 484 {
 485         return tdb->file->fd;
 486 }