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