git.ozlabs.org Git - ccan/blob - ccan/tdb2/check.c

   1  /*
   2    Trivial Database 2: free list/block handling
   3    Copyright (C) Rusty Russell 2010
   4
   5    This library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 3 of the License, or (at your option) any later version.
   9
  10    This library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17 */
  18 #include "private.h"
  19 #include <ccan/likely/likely.h>
  20 #include <ccan/asearch/asearch.h>
  21
  22 /* We keep an ordered array of offsets. */
  23 static bool append(tdb_off_t **arr, size_t *num, tdb_off_t off)
  24 {
  25         tdb_off_t *new = realloc(*arr, (*num + 1) * sizeof(tdb_off_t));
  26         if (!new)
  27                 return false;
  28         new[(*num)++] = off;
  29         *arr = new;
  30         return true;
  31 }
  32
  33 static bool check_header(struct tdb_context *tdb, tdb_off_t *recovery)
  34 {
  35         uint64_t hash_test;
  36         struct tdb_header hdr;
  37         enum TDB_ERROR ecode;
  38
  39         ecode = tdb_read_convert(tdb, 0, &hdr, sizeof(hdr));
  40         if (ecode != TDB_SUCCESS) {
  41                 tdb->ecode = ecode;
  42                 return false;
  43         }
  44         /* magic food should not be converted, so convert back. */
  45         tdb_convert(tdb, hdr.magic_food, sizeof(hdr.magic_food));
  46
  47         hash_test = TDB_HASH_MAGIC;
  48         hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
  49         if (hdr.hash_test != hash_test) {
  50                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
  51                            "check: hash test %llu should be %llu",
  52                            (long long)hdr.hash_test,
  53                            (long long)hash_test);
  54                 return false;
  55         }
  56
  57         if (strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
  58                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
  59                            "check: bad magic '%.*s'",
  60                            (unsigned)sizeof(hdr.magic_food), hdr.magic_food);
  61                 return false;
  62         }
  63
  64         *recovery = hdr.recovery;
  65         if (*recovery) {
  66                 if (*recovery < sizeof(hdr) || *recovery > tdb->map_size) {
  67                         tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
  68                                  "tdb_check: invalid recovery offset %zu",
  69                                  (size_t)*recovery);
  70                         return false;
  71                 }
  72         }
  73
  74         /* Don't check reserved: they *can* be used later. */
  75         return true;
  76 }
  77
  78 static bool check_hash_tree(struct tdb_context *tdb,
  79                             tdb_off_t off, unsigned int group_bits,
  80                             uint64_t hprefix,
  81                             unsigned hprefix_bits,
  82                             tdb_off_t used[],
  83                             size_t num_used,
  84                             size_t *num_found,
  85                             int (*check)(TDB_DATA, TDB_DATA, void *),
  86                             void *private_data);
  87
  88 static bool check_hash_chain(struct tdb_context *tdb,
  89                              tdb_off_t off,
  90                              uint64_t hash,
  91                              tdb_off_t used[],
  92                              size_t num_used,
  93                              size_t *num_found,
  94                              int (*check)(TDB_DATA, TDB_DATA, void *),
  95                              void *private_data)
  96 {
  97         struct tdb_used_record rec;
  98         enum TDB_ERROR ecode;
  99
 100         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec));
 101         if (ecode != TDB_SUCCESS) {
 102                 tdb->ecode = ecode;
 103                 return false;
 104         }
 105
 106         if (rec_magic(&rec) != TDB_CHAIN_MAGIC) {
 107                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 108                            "tdb_check: Bad hash chain magic %llu",
 109                            (long long)rec_magic(&rec));
 110                 return false;
 111         }
 112
 113         if (rec_data_length(&rec) != sizeof(struct tdb_chain)) {
 114                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 115                            "tdb_check: Bad hash chain length %llu vs %zu",
 116                            (long long)rec_data_length(&rec),
 117                            sizeof(struct tdb_chain));
 118                 return false;
 119         }
 120         if (rec_key_length(&rec) != 0) {
 121                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 122                          "tdb_check: Bad hash chain key length %llu",
 123                          (long long)rec_key_length(&rec));
 124                 return false;
 125         }
 126         if (rec_hash(&rec) != 0) {
 127                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 128                          "tdb_check: Bad hash chain hash value %llu",
 129                          (long long)rec_hash(&rec));
 130                 return false;
 131         }
 132
 133         off += sizeof(rec);
 134         if (!check_hash_tree(tdb, off, 0, hash, 64,
 135                              used, num_used, num_found, check, private_data))
 136                 return false;
 137
 138         off = tdb_read_off(tdb, off + offsetof(struct tdb_chain, next));
 139         if (off == TDB_OFF_ERR)
 140                 return false;
 141         if (off == 0)
 142                 return true;
 143         (*num_found)++;
 144         return check_hash_chain(tdb, off, hash, used, num_used, num_found,
 145                                 check, private_data);
 146 }
 147
 148 static bool check_hash_record(struct tdb_context *tdb,
 149                               tdb_off_t off,
 150                               uint64_t hprefix,
 151                               unsigned hprefix_bits,
 152                               tdb_off_t used[],
 153                               size_t num_used,
 154                               size_t *num_found,
 155                               int (*check)(TDB_DATA, TDB_DATA, void *),
 156                               void *private_data)
 157 {
 158         struct tdb_used_record rec;
 159         enum TDB_ERROR ecode;
 160
 161         if (hprefix_bits >= 64)
 162                 return check_hash_chain(tdb, off, hprefix, used, num_used,
 163                                         num_found, check, private_data);
 164
 165         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec));
 166         if (ecode != TDB_SUCCESS) {
 167                 tdb->ecode = ecode;
 168                 return false;
 169         }
 170
 171         if (rec_magic(&rec) != TDB_HTABLE_MAGIC) {
 172                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 173                            "tdb_check: Bad hash table magic %llu",
 174                            (long long)rec_magic(&rec));
 175                 return false;
 176         }
 177         if (rec_data_length(&rec)
 178             != sizeof(tdb_off_t) << TDB_SUBLEVEL_HASH_BITS) {
 179                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 180                            "tdb_check: Bad hash table length %llu vs %llu",
 181                            (long long)rec_data_length(&rec),
 182                            (long long)sizeof(tdb_off_t)
 183                            << TDB_SUBLEVEL_HASH_BITS);
 184                 return false;
 185         }
 186         if (rec_key_length(&rec) != 0) {
 187                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 188                          "tdb_check: Bad hash table key length %llu",
 189                          (long long)rec_key_length(&rec));
 190                 return false;
 191         }
 192         if (rec_hash(&rec) != 0) {
 193                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 194                          "tdb_check: Bad hash table hash value %llu",
 195                          (long long)rec_hash(&rec));
 196                 return false;
 197         }
 198
 199         off += sizeof(rec);
 200         return check_hash_tree(tdb, off,
 201                                TDB_SUBLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS,
 202                                hprefix, hprefix_bits,
 203                                used, num_used, num_found, check, private_data);
 204 }
 205
 206 static int off_cmp(const tdb_off_t *a, const tdb_off_t *b)
 207 {
 208         /* Can overflow an int. */
 209         return *a > *b ? 1
 210                 : *a < *b ? -1
 211                 : 0;
 212 }
 213
 214 static uint64_t get_bits(uint64_t h, unsigned num, unsigned *used)
 215 {
 216         *used += num;
 217
 218         return (h >> (64 - *used)) & ((1U << num) - 1);
 219 }
 220
 221 static bool check_hash_tree(struct tdb_context *tdb,
 222                             tdb_off_t off, unsigned int group_bits,
 223                             uint64_t hprefix,
 224                             unsigned hprefix_bits,
 225                             tdb_off_t used[],
 226                             size_t num_used,
 227                             size_t *num_found,
 228                             int (*check)(TDB_DATA, TDB_DATA, void *),
 229                             void *private_data)
 230 {
 231         unsigned int g, b;
 232         const tdb_off_t *hash;
 233         struct tdb_used_record rec;
 234         enum TDB_ERROR ecode;
 235
 236         hash = tdb_access_read(tdb, off,
 237                                sizeof(tdb_off_t)
 238                                << (group_bits + TDB_HASH_GROUP_BITS),
 239                                true);
 240         if (!hash)
 241                 return false;
 242
 243         for (g = 0; g < (1 << group_bits); g++) {
 244                 const tdb_off_t *group = hash + (g << TDB_HASH_GROUP_BITS);
 245                 for (b = 0; b < (1 << TDB_HASH_GROUP_BITS); b++) {
 246                         unsigned int bucket, i, used_bits;
 247                         uint64_t h;
 248                         tdb_off_t *p;
 249                         if (group[b] == 0)
 250                                 continue;
 251
 252                         off = group[b] & TDB_OFF_MASK;
 253                         p = asearch(&off, used, num_used, off_cmp);
 254                         if (!p) {
 255                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 256                                            TDB_LOG_ERROR,
 257                                            "tdb_check: Invalid offset %llu "
 258                                            "in hash", (long long)off);
 259                                 goto fail;
 260                         }
 261                         /* Mark it invalid. */
 262                         *p ^= 1;
 263                         (*num_found)++;
 264
 265                         if (hprefix_bits == 64) {
 266                                 /* Chained entries are unordered. */
 267                                 if (is_subhash(group[b])) {
 268                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 269                                                    TDB_LOG_ERROR,
 270                                                    "tdb_check: Invalid chain"
 271                                                    " entry subhash");
 272                                         goto fail;
 273                                 }
 274                                 h = hash_record(tdb, off);
 275                                 if (h != hprefix) {
 276                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 277                                                    TDB_LOG_ERROR,
 278                                                    "check: bad hash chain"
 279                                                    " placement"
 280                                                    " 0x%llx vs 0x%llx",
 281                                                    (long long)h,
 282                                                    (long long)hprefix);
 283                                         goto fail;
 284                                 }
 285                                 ecode = tdb_read_convert(tdb, off, &rec,
 286                                                          sizeof(rec));
 287                                 if (ecode != TDB_SUCCESS) {
 288                                         tdb->ecode = ecode;
 289                                         goto fail;
 290                                 }
 291                                 goto check;
 292                         }
 293
 294                         if (is_subhash(group[b])) {
 295                                 uint64_t subprefix;
 296                                 subprefix = (hprefix
 297                                      << (group_bits + TDB_HASH_GROUP_BITS))
 298                                         + g * (1 << TDB_HASH_GROUP_BITS) + b;
 299
 300                                 if (!check_hash_record(tdb,
 301                                                group[b] & TDB_OFF_MASK,
 302                                                subprefix,
 303                                                hprefix_bits
 304                                                        + group_bits
 305                                                        + TDB_HASH_GROUP_BITS,
 306                                                used, num_used, num_found,
 307                                                check, private_data))
 308                                         goto fail;
 309                                 continue;
 310                         }
 311                         /* A normal entry */
 312
 313                         /* Does it belong here at all? */
 314                         h = hash_record(tdb, off);
 315                         used_bits = 0;
 316                         if (get_bits(h, hprefix_bits, &used_bits) != hprefix
 317                             && hprefix_bits) {
 318                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 319                                            TDB_LOG_ERROR,
 320                                            "check: bad hash placement"
 321                                            " 0x%llx vs 0x%llx",
 322                                          (long long)h, (long long)hprefix);
 323                                 goto fail;
 324                         }
 325
 326                         /* Does it belong in this group? */
 327                         if (get_bits(h, group_bits, &used_bits) != g) {
 328                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 329                                            TDB_LOG_ERROR,
 330                                            "check: bad group %llu vs %u",
 331                                            (long long)h, g);
 332                                 goto fail;
 333                         }
 334
 335                         /* Are bucket bits correct? */
 336                         bucket = group[b] & TDB_OFF_HASH_GROUP_MASK;
 337                         if (get_bits(h, TDB_HASH_GROUP_BITS, &used_bits)
 338                             != bucket) {
 339                                 used_bits -= TDB_HASH_GROUP_BITS;
 340                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 341                                            TDB_LOG_ERROR,
 342                                          "check: bad bucket %u vs %u",
 343                                          (unsigned)get_bits(h,
 344                                                         TDB_HASH_GROUP_BITS,
 345                                                         &used_bits),
 346                                          bucket);
 347                                 goto fail;
 348                         }
 349
 350                         /* There must not be any zero entries between
 351                          * the bucket it belongs in and this one! */
 352                         for (i = bucket;
 353                              i != b;
 354                              i = (i + 1) % (1 << TDB_HASH_GROUP_BITS)) {
 355                                 if (group[i] == 0) {
 356                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 357                                                    TDB_LOG_ERROR,
 358                                                    "check: bad group placement"
 359                                                    " %u vs %u",
 360                                                    b, bucket);
 361                                         goto fail;
 362                                 }
 363                         }
 364
 365                         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec));
 366                         if (ecode != TDB_SUCCESS) {
 367                                 tdb->ecode = ecode;
 368                                 goto fail;
 369                         }
 370
 371                         /* Bottom bits must match header. */
 372                         if ((h & ((1 << 11)-1)) != rec_hash(&rec)) {
 373                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 374                                            TDB_LOG_ERROR,
 375                                            "tdb_check: Bad hash magic at"
 376                                            " offset %llu (0x%llx vs 0x%llx)",
 377                                            (long long)off,
 378                                            (long long)h,
 379                                            (long long)rec_hash(&rec));
 380                                 goto fail;
 381                         }
 382
 383                 check:
 384                         if (check) {
 385                                 TDB_DATA key, data;
 386                                 key.dsize = rec_key_length(&rec);
 387                                 data.dsize = rec_data_length(&rec);
 388                                 key.dptr = (void *)tdb_access_read(tdb,
 389                                                    off + sizeof(rec),
 390                                                    key.dsize + data.dsize,
 391                                                    false);
 392                                 if (!key.dptr)
 393                                         goto fail;
 394                                 data.dptr = key.dptr + key.dsize;
 395                                 if (check(key, data, private_data) != 0)
 396                                         goto fail;
 397                                 tdb_access_release(tdb, key.dptr);
 398                         }
 399                 }
 400         }
 401         tdb_access_release(tdb, hash);
 402         return true;
 403
 404 fail:
 405         tdb_access_release(tdb, hash);
 406         return false;
 407 }
 408
 409 static bool check_hash(struct tdb_context *tdb,
 410                        tdb_off_t used[],
 411                        size_t num_used, size_t num_ftables,
 412                        int (*check)(TDB_DATA, TDB_DATA, void *),
 413                        void *private_data)
 414 {
 415         /* Free tables also show up as used. */
 416         size_t num_found = num_ftables;
 417
 418         if (!check_hash_tree(tdb, offsetof(struct tdb_header, hashtable),
 419                              TDB_TOPLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS,
 420                              0, 0, used, num_used, &num_found,
 421                              check, private_data))
 422                 return false;
 423
 424         if (num_found != num_used) {
 425                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 426                            "tdb_check: Not all entries are in hash");
 427                 return false;
 428         }
 429         return true;
 430 }
 431
 432 static bool check_free(struct tdb_context *tdb,
 433                        tdb_off_t off,
 434                        const struct tdb_free_record *frec,
 435                        tdb_off_t prev, unsigned int ftable,
 436                        unsigned int bucket)
 437 {
 438         enum TDB_ERROR ecode;
 439
 440         if (frec_magic(frec) != TDB_FREE_MAGIC) {
 441                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 442                            "tdb_check: offset %llu bad magic 0x%llx",
 443                            (long long)off, (long long)frec->magic_and_prev);
 444                 return false;
 445         }
 446         if (frec_ftable(frec) != ftable) {
 447                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 448                            "tdb_check: offset %llu bad freetable %u",
 449                            (long long)off, frec_ftable(frec));
 450                 return false;
 451         }
 452
 453         ecode = tdb->methods->oob(tdb, off
 454                                   + frec_len(frec)
 455                                   + sizeof(struct tdb_used_record),
 456                                   false);
 457         if (ecode != TDB_SUCCESS) {
 458                 tdb->ecode = ecode;
 459                 return false;
 460         }
 461         if (size_to_bucket(frec_len(frec)) != bucket) {
 462                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 463                            "tdb_check: offset %llu in wrong bucket %u vs %u",
 464                            (long long)off,
 465                            bucket, size_to_bucket(frec_len(frec)));
 466                 return false;
 467         }
 468         if (prev != frec_prev(frec)) {
 469                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 470                            "tdb_check: offset %llu bad prev %llu vs %llu",
 471                            (long long)off,
 472                            (long long)prev, (long long)frec_len(frec));
 473                 return false;
 474         }
 475         return true;
 476 }
 477
 478 static bool check_free_table(struct tdb_context *tdb,
 479                              tdb_off_t ftable_off,
 480                              unsigned ftable_num,
 481                              tdb_off_t fr[],
 482                              size_t num_free,
 483                              size_t *num_found)
 484 {
 485         struct tdb_freetable ft;
 486         tdb_off_t h;
 487         unsigned int i;
 488         enum TDB_ERROR ecode;
 489
 490         ecode = tdb_read_convert(tdb, ftable_off, &ft, sizeof(ft));
 491         if (ecode != TDB_SUCCESS) {
 492                 tdb->ecode = ecode;
 493                 return false;
 494         }
 495
 496         if (rec_magic(&ft.hdr) != TDB_FTABLE_MAGIC
 497             || rec_key_length(&ft.hdr) != 0
 498             || rec_data_length(&ft.hdr) != sizeof(ft) - sizeof(ft.hdr)
 499             || rec_hash(&ft.hdr) != 0) {
 500                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 501                            "tdb_check: Invalid header on free table");
 502                 return false;
 503         }
 504
 505         for (i = 0; i < TDB_FREE_BUCKETS; i++) {
 506                 tdb_off_t off, prev = 0, *p;
 507                 struct tdb_free_record f;
 508
 509                 h = bucket_off(ftable_off, i);
 510                 for (off = tdb_read_off(tdb, h); off; off = f.next) {
 511                         if (off == TDB_OFF_ERR)
 512                                 return false;
 513                         ecode = tdb_read_convert(tdb, off, &f, sizeof(f));
 514                         if (ecode != TDB_SUCCESS) {
 515                                 tdb->ecode = ecode;
 516                                 return false;
 517                         }
 518                         if (!check_free(tdb, off, &f, prev, ftable_num, i))
 519                                 return false;
 520
 521                         /* FIXME: Check hash bits */
 522                         p = asearch(&off, fr, num_free, off_cmp);
 523                         if (!p) {
 524                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 525                                            TDB_LOG_ERROR,
 526                                            "tdb_check: Invalid offset"
 527                                            " %llu in free table",
 528                                            (long long)off);
 529                                 return false;
 530                         }
 531                         /* Mark it invalid. */
 532                         *p ^= 1;
 533                         (*num_found)++;
 534                         prev = off;
 535                 }
 536         }
 537         return true;
 538 }
 539
 540 /* Slow, but should be very rare. */
 541 size_t dead_space(struct tdb_context *tdb, tdb_off_t off)
 542 {
 543         size_t len;
 544         enum TDB_ERROR ecode;
 545
 546         for (len = 0; off + len < tdb->map_size; len++) {
 547                 char c;
 548                 ecode = tdb->methods->tread(tdb, off, &c, 1);
 549                 if (ecode != TDB_SUCCESS) {
 550                         tdb->ecode = ecode;
 551                         return 0;
 552                 }
 553                 if (c != 0 && c != 0x43)
 554                         break;
 555         }
 556         return len;
 557 }
 558
 559 static bool check_linear(struct tdb_context *tdb,
 560                          tdb_off_t **used, size_t *num_used,
 561                          tdb_off_t **fr, size_t *num_free,
 562                          tdb_off_t recovery)
 563 {
 564         tdb_off_t off;
 565         tdb_len_t len;
 566         enum TDB_ERROR ecode;
 567         bool found_recovery = false;
 568
 569         for (off = sizeof(struct tdb_header); off < tdb->map_size; off += len) {
 570                 union {
 571                         struct tdb_used_record u;
 572                         struct tdb_free_record f;
 573                         struct tdb_recovery_record r;
 574                 } rec;
 575                 /* r is larger: only get that if we need to. */
 576                 ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec.f));
 577                 if (ecode != TDB_SUCCESS) {
 578                         tdb->ecode = ecode;
 579                         return false;
 580                 }
 581
 582                 /* If we crash after ftruncate, we can get zeroes or fill. */
 583                 if (rec.r.magic == TDB_RECOVERY_INVALID_MAGIC
 584                     || rec.r.magic ==  0x4343434343434343ULL) {
 585                         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec.r));
 586                         if (ecode != TDB_SUCCESS) {
 587                                 tdb->ecode = ecode;
 588                                 return false;
 589                         }
 590                         if (recovery == off) {
 591                                 found_recovery = true;
 592                                 len = sizeof(rec.r) + rec.r.max_len;
 593                         } else {
 594                                 len = dead_space(tdb, off);
 595                                 if (len < sizeof(rec.r)) {
 596                                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 597                                                    TDB_LOG_ERROR,
 598                                                    "tdb_check: invalid dead"
 599                                                    " space at %zu",
 600                                                    (size_t)off);
 601                                         return false;
 602                                 }
 603
 604                                 tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
 605                                            "Dead space at %zu-%zu (of %zu)",
 606                                            (size_t)off, (size_t)(off + len),
 607                                            (size_t)tdb->map_size);
 608                         }
 609                 } else if (rec.r.magic == TDB_RECOVERY_MAGIC) {
 610                         ecode = tdb_read_convert(tdb, off, &rec, sizeof(rec.r));
 611                         if (ecode != TDB_SUCCESS) {
 612                                 tdb->ecode = ecode;
 613                                 return false;
 614                         }
 615                         if (recovery != off) {
 616                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 617                                            TDB_LOG_ERROR,
 618                                            "tdb_check: unexpected recovery"
 619                                            " record at offset %zu",
 620                                            (size_t)off);
 621                                 return false;
 622                         }
 623                         if (rec.r.len > rec.r.max_len) {
 624                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 625                                            TDB_LOG_ERROR,
 626                                            "tdb_check: invalid recovery length"
 627                                            " %zu", (size_t)rec.r.len);
 628                                 return false;
 629                         }
 630                         if (rec.r.eof > tdb->map_size) {
 631                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 632                                            TDB_LOG_ERROR,
 633                                            "tdb_check: invalid old EOF"
 634                                            " %zu", (size_t)rec.r.eof);
 635                                 return false;
 636                         }
 637                         found_recovery = true;
 638                         len = sizeof(rec.r) + rec.r.max_len;
 639                 } else if (frec_magic(&rec.f) == TDB_FREE_MAGIC) {
 640                         len = sizeof(rec.u) + frec_len(&rec.f);
 641                         if (off + len > tdb->map_size) {
 642                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 643                                            TDB_LOG_ERROR,
 644                                            "tdb_check: free overlength %llu"
 645                                            " at offset %llu",
 646                                            (long long)len, (long long)off);
 647                                 return false;
 648                         }
 649                         /* This record should be in free lists. */
 650                         if (frec_ftable(&rec.f) != TDB_FTABLE_NONE
 651                             && !append(fr, num_free, off)) {
 652                                 tdb_logerr(tdb, TDB_ERR_OOM,
 653                                            TDB_LOG_ERROR,
 654                                            "tdb_check: tracking %zu'th"
 655                                            " free record.", *num_free);
 656                                 return false;
 657                         }
 658                 } else if (rec_magic(&rec.u) == TDB_USED_MAGIC
 659                            || rec_magic(&rec.u) == TDB_CHAIN_MAGIC
 660                            || rec_magic(&rec.u) == TDB_HTABLE_MAGIC
 661                            || rec_magic(&rec.u) == TDB_FTABLE_MAGIC) {
 662                         uint64_t klen, dlen, extra;
 663
 664                         /* This record is used! */
 665                         if (!append(used, num_used, off)) {
 666                                 tdb_logerr(tdb, TDB_ERR_OOM,
 667                                            TDB_LOG_ERROR,
 668                                            "tdb_check: tracking %zu'th"
 669                                            " used record.", *num_used);
 670                                 return false;
 671                         }
 672
 673                         klen = rec_key_length(&rec.u);
 674                         dlen = rec_data_length(&rec.u);
 675                         extra = rec_extra_padding(&rec.u);
 676
 677                         len = sizeof(rec.u) + klen + dlen + extra;
 678                         if (off + len > tdb->map_size) {
 679                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 680                                            TDB_LOG_ERROR,
 681                                            "tdb_check: used overlength %llu"
 682                                            " at offset %llu",
 683                                            (long long)len, (long long)off);
 684                                 return false;
 685                         }
 686
 687                         if (len < sizeof(rec.f)) {
 688                                 tdb_logerr(tdb, TDB_ERR_CORRUPT,
 689                                            TDB_LOG_ERROR,
 690                                            "tdb_check: too short record %llu"
 691                                            " at %llu",
 692                                            (long long)len, (long long)off);
 693                                 return false;
 694                         }
 695                 } else {
 696                         tdb_logerr(tdb, TDB_ERR_CORRUPT,
 697                                    TDB_LOG_ERROR,
 698                                    "tdb_check: Bad magic 0x%llx at offset %zu",
 699                                    (long long)rec_magic(&rec.u), (size_t)off);
 700                         return false;
 701                 }
 702         }
 703
 704         /* We must have found recovery area if there was one. */
 705         if (recovery != 0 && !found_recovery) {
 706                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 707                            "tdb_check: expected a recovery area at %zu",
 708                            (size_t)recovery);
 709                 return false;
 710         }
 711
 712         return true;
 713 }
 714
 715 int tdb_check(struct tdb_context *tdb,
 716               int (*check)(TDB_DATA key, TDB_DATA data, void *private_data),
 717               void *private_data)
 718 {
 719         tdb_off_t *fr = NULL, *used = NULL, ft, recovery;
 720         size_t num_free = 0, num_used = 0, num_found = 0, num_ftables = 0;
 721         enum TDB_ERROR ecode;
 722
 723         ecode = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);
 724         if (ecpde != TDB_SUCCESS) {
 725                 tdb->ecode = ecode;
 726                 return -1;
 727         }
 728
 729         ecode = tdb_lock_expand(tdb, F_RDLCK);
 730         if (ecode != TDB_SUCCESS) {
 731                 tdb->ecode = ecode;
 732                 tdb_allrecord_unlock(tdb, F_RDLCK);
 733                 return -1;
 734         }
 735
 736         if (!check_header(tdb, &recovery))
 737                 goto fail;
 738
 739         /* First we do a linear scan, checking all records. */
 740         if (!check_linear(tdb, &used, &num_used, &fr, &num_free, recovery))
 741                 goto fail;
 742
 743         for (ft = first_ftable(tdb); ft; ft = next_ftable(tdb, ft)) {
 744                 if (ft == TDB_OFF_ERR)
 745                         goto fail;
 746                 if (!check_free_table(tdb, ft, num_ftables, fr, num_free,
 747                                       &num_found))
 748                         goto fail;
 749                 num_ftables++;
 750         }
 751
 752         /* FIXME: Check key uniqueness? */
 753         if (!check_hash(tdb, used, num_used, num_ftables, check, private_data))
 754                 goto fail;
 755
 756         if (num_found != num_free) {
 757                 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 758                            "tdb_check: Not all entries are in free table");
 759                 return -1;
 760         }
 761
 762         tdb_allrecord_unlock(tdb, F_RDLCK);
 763         tdb_unlock_expand(tdb, F_RDLCK);
 764         free(fr);
 765         free(used);
 766         return 0;
 767
 768 fail:
 769         free(fr);
 770         free(used);
 771         tdb_allrecord_unlock(tdb, F_RDLCK);
 772         tdb_unlock_expand(tdb, F_RDLCK);
 773         return -1;
 774 }