/* Unix SMB/CIFS implementation. trivial database library - private includes Copyright (C) Andrew Tridgell 2005 ** NOTE! The following LGPL license applies to the tdb ** library. This does NOT imply that all of Samba is released ** under the LGPL This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, see . */ #include "replace.h" #include "system/filesys.h" #include "system/time.h" #include "system/shmem.h" #include "system/select.h" #include "system/wait.h" #include "tdb.h" #ifndef HAVE_GETPAGESIZE #define getpagesize() 0x2000 #endif typedef uint32_t tdb_len_t; typedef uint32_t tdb_off_t; #ifndef offsetof #define offsetof(t,f) ((unsigned int)&((t *)0)->f) #endif #define TDB_MAGIC_FOOD "TDB file\n" #define TDB_VERSION (0x26011967 + 6) #define TDB_MAGIC (0x26011999U) #define TDB_FREE_MAGIC (~TDB_MAGIC) #define TDB_DEAD_MAGIC (0xFEE1DEAD) #define TDB_RECOVERY_MAGIC (0xf53bc0e7U) #define TDB_ALIGNMENT 4 #define DEFAULT_HASH_SIZE 131 #define FREELIST_TOP (sizeof(struct tdb_header)) #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1)) #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24)) #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC) #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r)) #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t)) #define TDB_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb_off_t)) #define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + sizeof(tdb_off_t)) #define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start) #define TDB_SEQNUM_OFS offsetof(struct tdb_header, sequence_number) #define TDB_PAD_BYTE 0x42 #define TDB_PAD_U32 0x42424242 /* NB assumes there is a local variable called "tdb" that is the * current context, also takes doubly-parenthesized print-style * argument. */ #define TDB_LOG(x) tdb->log.log_fn x /* lock offsets */ #define GLOBAL_LOCK 0 #define ACTIVE_LOCK 4 #define TRANSACTION_LOCK 8 /* free memory if the pointer is valid and zero the pointer */ #ifndef SAFE_FREE #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0) #endif #define BUCKET(hash) ((hash) % tdb->header.hash_size) #define DOCONV() (tdb->flags & TDB_CONVERT) #define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x) /* the body of the database is made of one list_struct for the free space plus a separate data list for each hash value */ struct list_struct { tdb_off_t next; /* offset of the next record in the list */ tdb_len_t rec_len; /* total byte length of record */ tdb_len_t key_len; /* byte length of key */ tdb_len_t data_len; /* byte length of data */ uint32_t full_hash; /* the full 32 bit hash of the key */ uint32_t magic; /* try to catch errors */ /* the following union is implied: union { char record[rec_len]; struct { char key[key_len]; char data[data_len]; } uint32_t totalsize; (tailer) } */ }; /* this is stored at the front of every database */ struct tdb_header { char magic_food[32]; /* for /etc/magic */ uint32_t version; /* version of the code */ uint32_t hash_size; /* number of hash entries */ tdb_off_t rwlocks; /* obsolete - kept to detect old formats */ tdb_off_t recovery_start; /* offset of transaction recovery region */ tdb_off_t sequence_number; /* used when TDB_SEQNUM is set */ tdb_off_t reserved[29]; }; struct tdb_lock_type { int list; uint32_t count; uint32_t ltype; }; struct tdb_traverse_lock { struct tdb_traverse_lock *next; uint32_t off; uint32_t hash; int lock_rw; }; struct tdb_methods { int (*tdb_read)(struct tdb_context *, tdb_off_t , void *, tdb_len_t , int ); int (*tdb_write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t); void (*next_hash_chain)(struct tdb_context *, uint32_t *); int (*tdb_oob)(struct tdb_context *, tdb_off_t , int ); int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t ); int (*tdb_brlock)(struct tdb_context *, tdb_off_t , int, int, int, size_t); }; struct tdb_context { char *name; /* the name of the database */ void *map_ptr; /* where it is currently mapped */ int fd; /* open file descriptor for the database */ tdb_len_t map_size; /* how much space has been mapped */ int read_only; /* opened read-only */ int traverse_read; /* read-only traversal */ int traverse_write; /* read-write traversal */ struct tdb_lock_type global_lock; int num_lockrecs; struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */ enum TDB_ERROR ecode; /* error code for last tdb error */ struct tdb_header header; /* a cached copy of the header */ uint32_t flags; /* the flags passed to tdb_open */ struct tdb_traverse_lock travlocks; /* current traversal locks */ struct tdb_context *next; /* all tdbs to avoid multiple opens */ dev_t device; /* uniquely identifies this tdb */ ino_t inode; /* uniquely identifies this tdb */ struct tdb_logging_context log; unsigned int (*hash_fn)(TDB_DATA *key); int open_flags; /* flags used in the open - needed by reopen */ unsigned int num_locks; /* number of chain locks held */ const struct tdb_methods *methods; struct tdb_transaction *transaction; int page_size; int max_dead_records; bool have_transaction_lock; volatile sig_atomic_t *interrupt_sig_ptr; }; /* internal prototypes */ int tdb_munmap(struct tdb_context *tdb); void tdb_mmap(struct tdb_context *tdb); int tdb_lock(struct tdb_context *tdb, int list, int ltype); int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype); int tdb_unlock(struct tdb_context *tdb, int list, int ltype); int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, int rw_type, int lck_type, int probe, size_t len); int tdb_transaction_lock(struct tdb_context *tdb, int ltype); int tdb_transaction_unlock(struct tdb_context *tdb); int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len); int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off); int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off); int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); void *tdb_convert(void *buf, uint32_t size); int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec); int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off); int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off); int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec); unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len); int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key, tdb_off_t offset, tdb_len_t len, int (*parser)(TDB_DATA key, TDB_DATA data, void *private_data), void *private_data); tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype, struct list_struct *rec); void tdb_io_init(struct tdb_context *tdb); int tdb_expand(struct tdb_context *tdb, tdb_off_t size); int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off, struct list_struct *rec);