lib/tdb/common/tdb_private.h

   1 #ifndef TDB_PRIVATE_H
   2 #define TDB_PRIVATE_H
   3  /*
   4    Unix SMB/CIFS implementation.
   5
   6    trivial database library - private includes
   7
   8    Copyright (C) Andrew Tridgell              2005
   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
  28 #include "replace.h"
  29 #include "system/filesys.h"
  30 #include "system/time.h"
  31 #include "system/shmem.h"
  32 #include "system/select.h"
  33 #include "system/wait.h"
  34 #include "tdb.h"
  35
  36 /* #define TDB_TRACE 1 */
  37 #ifndef HAVE_GETPAGESIZE
  38 #define getpagesize() 0x2000
  39 #endif
  40
  41 typedef uint32_t tdb_len_t;
  42 typedef uint32_t tdb_off_t;
  43
  44 #ifndef offsetof
  45 #define offsetof(t,f) ((unsigned int)&((t *)0)->f)
  46 #endif
  47
  48 #define TDB_MAGIC_FOOD "TDB file\n"
  49 #define TDB_VERSION (0x26011967 + 6)
  50 #define TDB_MAGIC (0x26011999U)
  51 #define TDB_FREE_MAGIC (~TDB_MAGIC)
  52 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
  53 #define TDB_RECOVERY_MAGIC (0xf53bc0e7U)
  54 #define TDB_RECOVERY_INVALID_MAGIC (0x0)
  55 #define TDB_HASH_RWLOCK_MAGIC (0xbad1a51U)
  56 #define TDB_ALIGNMENT 4
  57 #define DEFAULT_HASH_SIZE 131
  58 #define FREELIST_TOP (sizeof(struct tdb_header))
  59 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
  60 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
  61 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
  62 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
  63 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t))
  64 #define TDB_HASHTABLE_SIZE(tdb) ((tdb->hash_size+1)*sizeof(tdb_off_t))
  65 #define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + sizeof(tdb_off_t))
  66 #define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start)
  67 #define TDB_SEQNUM_OFS    offsetof(struct tdb_header, sequence_number)
  68 #define TDB_PAD_BYTE 0x42
  69 #define TDB_PAD_U32  0x42424242
  70
  71 /* NB assumes there is a local variable called "tdb" that is the
  72  * current context, also takes doubly-parenthesized print-style
  73  * argument. */
  74 #define TDB_LOG(x) tdb->log.log_fn x
  75
  76 #ifdef TDB_TRACE
  77 void tdb_trace(struct tdb_context *tdb, const char *op);
  78 void tdb_trace_seqnum(struct tdb_context *tdb, uint32_t seqnum, const char *op);
  79 void tdb_trace_open(struct tdb_context *tdb, const char *op,
  80                     unsigned hash_size, unsigned tdb_flags, unsigned open_flags);
  81 void tdb_trace_ret(struct tdb_context *tdb, const char *op, int ret);
  82 void tdb_trace_retrec(struct tdb_context *tdb, const char *op, TDB_DATA ret);
  83 void tdb_trace_1rec(struct tdb_context *tdb, const char *op,
  84                     TDB_DATA rec);
  85 void tdb_trace_1rec_ret(struct tdb_context *tdb, const char *op,
  86                         TDB_DATA rec, int ret);
  87 void tdb_trace_1rec_retrec(struct tdb_context *tdb, const char *op,
  88                            TDB_DATA rec, TDB_DATA ret);
  89 void tdb_trace_2rec_flag_ret(struct tdb_context *tdb, const char *op,
  90                              TDB_DATA rec1, TDB_DATA rec2, unsigned flag,
  91                              int ret);
  92 void tdb_trace_2rec_retrec(struct tdb_context *tdb, const char *op,
  93                            TDB_DATA rec1, TDB_DATA rec2, TDB_DATA ret);
  94 #else
  95 #define tdb_trace(tdb, op)
  96 #define tdb_trace_seqnum(tdb, seqnum, op)
  97 #define tdb_trace_open(tdb, op, hash_size, tdb_flags, open_flags)
  98 #define tdb_trace_ret(tdb, op, ret)
  99 #define tdb_trace_retrec(tdb, op, ret)
 100 #define tdb_trace_1rec(tdb, op, rec)
 101 #define tdb_trace_1rec_ret(tdb, op, rec, ret)
 102 #define tdb_trace_1rec_retrec(tdb, op, rec, ret)
 103 #define tdb_trace_2rec_flag_ret(tdb, op, rec1, rec2, flag, ret)
 104 #define tdb_trace_2rec_retrec(tdb, op, rec1, rec2, ret)
 105 #endif /* !TDB_TRACE */
 106
 107 /* lock offsets */
 108 #define OPEN_LOCK        0
 109 #define ACTIVE_LOCK      4
 110 #define TRANSACTION_LOCK 8
 111
 112 /* free memory if the pointer is valid and zero the pointer */
 113 #ifndef SAFE_FREE
 114 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
 115 #endif
 116
 117 #define BUCKET(hash) ((hash) % tdb->hash_size)
 118
 119 #define DOCONV() (tdb->flags & TDB_CONVERT)
 120 #define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x)
 121
 122
 123 /* the body of the database is made of one tdb_record for the free space
 124    plus a separate data list for each hash value */
 125 struct tdb_record {
 126         tdb_off_t next; /* offset of the next record in the list */
 127         tdb_len_t rec_len; /* total byte length of record */
 128         tdb_len_t key_len; /* byte length of key */
 129         tdb_len_t data_len; /* byte length of data */
 130         uint32_t full_hash; /* the full 32 bit hash of the key */
 131         uint32_t magic;   /* try to catch errors */
 132         /* the following union is implied:
 133                 union {
 134                         char record[rec_len];
 135                         struct {
 136                                 char key[key_len];
 137                                 char data[data_len];
 138                         }
 139                         uint32_t totalsize; (tailer)
 140                 }
 141         */
 142 };
 143
 144
 145 /* this is stored at the front of every database */
 146 struct tdb_header {
 147         char magic_food[32]; /* for /etc/magic */
 148         uint32_t version; /* version of the code */
 149         uint32_t hash_size; /* number of hash entries */
 150         tdb_off_t rwlocks; /* obsolete - kept to detect old formats */
 151         tdb_off_t recovery_start; /* offset of transaction recovery region */
 152         tdb_off_t sequence_number; /* used when TDB_SEQNUM is set */
 153         uint32_t magic1_hash; /* hash of TDB_MAGIC_FOOD. */
 154         uint32_t magic2_hash; /* hash of TDB_MAGIC. */
 155         tdb_off_t reserved[27];
 156 };
 157
 158 struct tdb_lock_type {
 159         uint32_t off;
 160         uint32_t count;
 161         uint32_t ltype;
 162 };
 163
 164 struct tdb_traverse_lock {
 165         struct tdb_traverse_lock *next;
 166         uint32_t off;
 167         uint32_t hash;
 168         int lock_rw;
 169 };
 170
 171 enum tdb_lock_flags {
 172         /* WAIT == F_SETLKW, NOWAIT == F_SETLK */
 173         TDB_LOCK_NOWAIT = 0,
 174         TDB_LOCK_WAIT = 1,
 175         /* If set, don't log an error on failure. */
 176         TDB_LOCK_PROBE = 2,
 177         /* If set, don't actually lock at all. */
 178         TDB_LOCK_MARK_ONLY = 4,
 179 };
 180
 181 struct tdb_methods {
 182         int (*tdb_read)(struct tdb_context *, tdb_off_t , void *, tdb_len_t , int );
 183         int (*tdb_write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t);
 184         void (*next_hash_chain)(struct tdb_context *, uint32_t *);
 185         int (*tdb_oob)(struct tdb_context *, tdb_off_t , tdb_len_t, int );
 186         int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t );
 187 };
 188
 189 struct tdb_context {
 190         char *name; /* the name of the database */
 191         void *map_ptr; /* where it is currently mapped */
 192         int fd; /* open file descriptor for the database */
 193         tdb_len_t map_size; /* how much space has been mapped */
 194         int read_only; /* opened read-only */
 195         int traverse_read; /* read-only traversal */
 196         int traverse_write; /* read-write traversal */
 197         struct tdb_lock_type allrecord_lock; /* .offset == upgradable */
 198         int num_lockrecs;
 199         struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */
 200         enum TDB_ERROR ecode; /* error code for last tdb error */
 201         uint32_t hash_size;
 202         uint32_t flags; /* the flags passed to tdb_open */
 203         struct tdb_traverse_lock travlocks; /* current traversal locks */
 204         struct tdb_context *next; /* all tdbs to avoid multiple opens */
 205         dev_t device;   /* uniquely identifies this tdb */
 206         ino_t inode;    /* uniquely identifies this tdb */
 207         struct tdb_logging_context log;
 208         unsigned int (*hash_fn)(TDB_DATA *key);
 209         int open_flags; /* flags used in the open - needed by reopen */
 210         const struct tdb_methods *methods;
 211         struct tdb_transaction *transaction;
 212         int page_size;
 213         int max_dead_records;
 214 #ifdef TDB_TRACE
 215         int tracefd;
 216 #endif
 217         volatile sig_atomic_t *interrupt_sig_ptr;
 218 };
 219
 220
 221 /*
 222   internal prototypes
 223 */
 224 int tdb_munmap(struct tdb_context *tdb);
 225 int tdb_mmap(struct tdb_context *tdb);
 226 int tdb_lock(struct tdb_context *tdb, int list, int ltype);
 227 int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype);
 228 int tdb_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
 229                   enum tdb_lock_flags flags);
 230 int tdb_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype,
 231                     bool mark_lock);
 232 int tdb_unlock(struct tdb_context *tdb, int list, int ltype);
 233 int tdb_brlock(struct tdb_context *tdb,
 234                int rw_type, tdb_off_t offset, size_t len,
 235                enum tdb_lock_flags flags);
 236 int tdb_brunlock(struct tdb_context *tdb,
 237                  int rw_type, tdb_off_t offset, size_t len);
 238 bool tdb_have_extra_locks(struct tdb_context *tdb);
 239 void tdb_release_transaction_locks(struct tdb_context *tdb);
 240 int tdb_transaction_lock(struct tdb_context *tdb, int ltype,
 241                          enum tdb_lock_flags lockflags);
 242 int tdb_transaction_unlock(struct tdb_context *tdb, int ltype);
 243 int tdb_recovery_area(struct tdb_context *tdb,
 244                       const struct tdb_methods *methods,
 245                       tdb_off_t *recovery_offset,
 246                       struct tdb_record *rec);
 247 int tdb_allrecord_lock(struct tdb_context *tdb, int ltype,
 248                        enum tdb_lock_flags flags, bool upgradable);
 249 int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype, bool mark_lock);
 250 int tdb_allrecord_upgrade(struct tdb_context *tdb);
 251 int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off);
 252 int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off);
 253 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
 254 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
 255 void *tdb_convert(void *buf, uint32_t size);
 256 int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *rec);
 257 tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct tdb_record *rec);
 258 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
 259 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
 260 int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off);
 261 int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off);
 262 bool tdb_needs_recovery(struct tdb_context *tdb);
 263 int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *rec);
 264 int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *rec);
 265 int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct tdb_record *rec);
 266 unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len);
 267 int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key,
 268                    tdb_off_t offset, tdb_len_t len,
 269                    int (*parser)(TDB_DATA key, TDB_DATA data,
 270                                  void *private_data),
 271                    void *private_data);
 272 tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype,
 273                            struct tdb_record *rec);
 274 void tdb_io_init(struct tdb_context *tdb);
 275 int tdb_expand(struct tdb_context *tdb, tdb_off_t size);
 276 tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size);
 277 int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off,
 278                       struct tdb_record *rec);
 279 bool tdb_write_all(int fd, const void *buf, size_t count);
 280 int tdb_transaction_recover(struct tdb_context *tdb);
 281 void tdb_header_hash(struct tdb_context *tdb,
 282                      uint32_t *magic1_hash, uint32_t *magic2_hash);
 283 unsigned int tdb_old_hash(TDB_DATA *key);
 284 size_t tdb_dead_space(struct tdb_context *tdb, tdb_off_t off);
 285 #endif /* TDB_PRIVATE_H */