lib/tdb2/tdb1_open.c

   1  /*
   2    Unix SMB/CIFS implementation.
   3
   4    trivial database library
   5
   6    Copyright (C) Andrew Tridgell              1999-2005
   7    Copyright (C) Paul `Rusty' Russell              2000
   8    Copyright (C) Jeremy Allison                    2000-2003
   9
  10      ** NOTE! The following LGPL license applies to the tdb
  11      ** library. This does NOT imply that all of Samba is released
  12      ** under the LGPL
  13
  14    This library is free software; you can redistribute it and/or
  15    modify it under the terms of the GNU Lesser General Public
  16    License as published by the Free Software Foundation; either
  17    version 3 of the License, or (at your option) any later version.
  18
  19    This library is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22    Lesser General Public License for more details.
  23
  24    You should have received a copy of the GNU Lesser General Public
  25    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  26 */
  27 #include <assert.h>
  28 #include "tdb1_private.h"
  29 #include <assert.h>
  30
  31 /* We use two hashes to double-check they're using the right hash function. */
  32 void tdb1_header_hash(struct tdb_context *tdb,
  33                      uint32_t *magic1_hash, uint32_t *magic2_hash)
  34 {
  35         uint32_t tdb1_magic = TDB1_MAGIC;
  36
  37         *magic1_hash = tdb_hash(tdb, TDB_MAGIC_FOOD, sizeof(TDB_MAGIC_FOOD));
  38         *magic2_hash = tdb_hash(tdb, TDB1_CONV(tdb1_magic), sizeof(tdb1_magic));
  39
  40         /* Make sure at least one hash is non-zero! */
  41         if (*magic1_hash == 0 && *magic2_hash == 0)
  42                 *magic1_hash = 1;
  43 }
  44
  45 static void tdb_context_init(struct tdb_context *tdb,
  46                              struct tdb_attribute_tdb1_max_dead *max_dead)
  47 {
  48         assert(tdb->flags & TDB_VERSION1);
  49
  50         tdb1_io_init(tdb);
  51
  52         tdb->tdb1.traverse_read = tdb->tdb1.traverse_write = 0;
  53         memset(&tdb->tdb1.travlocks, 0, sizeof(tdb->tdb1.travlocks));
  54         tdb->tdb1.transaction = NULL;
  55
  56         /* cache the page size */
  57         tdb->tdb1.page_size = getpagesize();
  58         if (tdb->tdb1.page_size <= 0) {
  59                 tdb->tdb1.page_size = 0x2000;
  60         }
  61
  62         if (max_dead) {
  63                 tdb->tdb1.max_dead_records = max_dead->max_dead;
  64         } else {
  65                 tdb->tdb1.max_dead_records = 0;
  66         }
  67 }
  68
  69 /* initialise a new database */
  70 enum TDB_ERROR tdb1_new_database(struct tdb_context *tdb,
  71                                  struct tdb_attribute_tdb1_hashsize *hashsize,
  72                                  struct tdb_attribute_tdb1_max_dead *max_dead)
  73 {
  74         struct tdb1_header *newdb;
  75         size_t size;
  76         int hash_size = TDB1_DEFAULT_HASH_SIZE;
  77         enum TDB_ERROR ret;
  78
  79         tdb_context_init(tdb, max_dead);
  80
  81         /* Default TDB2 hash becomes default TDB1 hash. */
  82         if (tdb->hash_fn == tdb_jenkins_hash)
  83                 tdb->hash_fn = tdb1_old_hash;
  84
  85         if (hashsize)
  86                 hash_size = hashsize->hsize;
  87
  88         /* We make it up in memory, then write it out if not internal */
  89         size = sizeof(struct tdb1_header) + (hash_size+1)*sizeof(tdb1_off_t);
  90         if (!(newdb = (struct tdb1_header *)calloc(size, 1))) {
  91                 return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
  92                                   "Could not allocate new database header");
  93         }
  94
  95         /* Fill in the header */
  96         newdb->version = TDB1_VERSION;
  97         newdb->hash_size = hash_size;
  98
  99         tdb1_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
 100
 101         /* Make sure older tdbs (which don't check the magic hash fields)
 102          * will refuse to open this TDB. */
 103         if (tdb->hash_fn == tdb1_incompatible_hash)
 104                 newdb->rwlocks = TDB1_HASH_RWLOCK_MAGIC;
 105
 106         memcpy(&tdb->tdb1.header, newdb, sizeof(tdb->tdb1.header));
 107         /* This creates an endian-converted db. */
 108         TDB1_CONV(*newdb);
 109         /* Don't endian-convert the magic food! */
 110         memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
 111
 112         if (tdb->flags & TDB_INTERNAL) {
 113                 tdb->file->map_size = size;
 114                 tdb->file->map_ptr = (char *)newdb;
 115                 return TDB_SUCCESS;
 116         }
 117         if (lseek(tdb->file->fd, 0, SEEK_SET) == -1) {
 118                 ret = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 119                                  "tdb1_new_database: lseek failed");
 120                 goto fail;
 121         }
 122
 123         if (ftruncate(tdb->file->fd, 0) == -1) {
 124                 ret = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 125                                  "tdb1_new_database: ftruncate failed");
 126                 goto fail;
 127         }
 128
 129         if (!tdb1_write_all(tdb->file->fd, newdb, size)) {
 130                 ret = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 131                                  "tdb1_new_database: write failed");
 132                 goto fail;
 133         }
 134         ret = TDB_SUCCESS;
 135
 136   fail:
 137         SAFE_FREE(newdb);
 138         return ret;
 139 }
 140
 141 typedef void (*tdb1_log_func)(struct tdb_context *, enum tdb_log_level, enum TDB_ERROR,
 142                               const char *, void *);
 143 typedef uint64_t (*tdb1_hash_func)(const void *key, size_t len, uint64_t seed,
 144                                    void *data);
 145
 146 struct tdb1_logging_context {
 147         tdb1_log_func log_fn;
 148         void *log_private;
 149 };
 150
 151 static bool hash_correct(struct tdb_context *tdb,
 152                          uint32_t *m1, uint32_t *m2)
 153 {
 154         /* older TDB without magic hash references */
 155         if (tdb->tdb1.header.magic1_hash == 0
 156             && tdb->tdb1.header.magic2_hash == 0) {
 157                 return true;
 158         }
 159
 160         tdb1_header_hash(tdb, m1, m2);
 161         return (tdb->tdb1.header.magic1_hash == *m1 &&
 162                 tdb->tdb1.header.magic2_hash == *m2);
 163 }
 164
 165 static bool check_header_hash(struct tdb_context *tdb,
 166                               uint32_t *m1, uint32_t *m2)
 167 {
 168         if (hash_correct(tdb, m1, m2))
 169                 return true;
 170
 171         /* If they use one inbuilt, try the other inbuilt hash. */
 172         if (tdb->hash_fn == tdb1_old_hash)
 173                 tdb->hash_fn = tdb1_incompatible_hash;
 174         else if (tdb->hash_fn == tdb1_incompatible_hash)
 175                 tdb->hash_fn = tdb1_old_hash;
 176         else
 177                 return false;
 178         return hash_correct(tdb, m1, m2);
 179 }
 180
 181 /* We are hold the TDB open lock on tdb->fd. */
 182 enum TDB_ERROR tdb1_open(struct tdb_context *tdb,
 183                          struct tdb_attribute_tdb1_max_dead *max_dead)
 184 {
 185         const char *hash_alg;
 186         uint32_t magic1, magic2;
 187
 188         tdb->flags |= TDB_VERSION1;
 189
 190         tdb_context_init(tdb, max_dead);
 191
 192         /* Default TDB2 hash becomes default TDB1 hash. */
 193         if (tdb->hash_fn == tdb_jenkins_hash) {
 194                 tdb->hash_fn = tdb1_old_hash;
 195                 hash_alg = "default";
 196         } else if (tdb->hash_fn == tdb1_incompatible_hash)
 197                 hash_alg = "tdb1_incompatible_hash";
 198         else
 199                 hash_alg = "the user defined";
 200
 201         if (tdb->tdb1.header.version != TDB1_BYTEREV(TDB1_VERSION)) {
 202                 if (tdb->flags & TDB_CONVERT) {
 203                         return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
 204                                           "tdb1_open:"
 205                                           " %s does not need TDB_CONVERT",
 206                                           tdb->name);
 207                 }
 208         } else {
 209                 tdb->flags |= TDB_CONVERT;
 210                 tdb1_convert(&tdb->tdb1.header, sizeof(tdb->tdb1.header));
 211         }
 212
 213         if (tdb->tdb1.header.rwlocks != 0 &&
 214             tdb->tdb1.header.rwlocks != TDB1_HASH_RWLOCK_MAGIC) {
 215                 return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
 216                                   "tdb1_open: spinlocks no longer supported");
 217         }
 218
 219         if (!check_header_hash(tdb, &magic1, &magic2)) {
 220                 return tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_USE_ERROR,
 221                            "tdb1_open: "
 222                            "%s was not created with %s hash function we are using\n"
 223                            "magic1_hash[0x%08X %s 0x%08X] "
 224                            "magic2_hash[0x%08X %s 0x%08X]",
 225                            tdb->name, hash_alg,
 226                            tdb->tdb1.header.magic1_hash,
 227                            (tdb->tdb1.header.magic1_hash == magic1) ? "==" : "!=",
 228                            magic1,
 229                            tdb->tdb1.header.magic2_hash,
 230                            (tdb->tdb1.header.magic2_hash == magic2) ? "==" : "!=",
 231                            magic2);
 232         }
 233         return TDB_SUCCESS;
 234 }