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Diffstat (limited to '')
| -rw-r--r-- | common/tdb_private.h | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/common/tdb_private.h b/common/tdb_private.h new file mode 100644 index 0000000..2979043 --- /dev/null +++ b/common/tdb_private.h @@ -0,0 +1,370 @@ +#ifndef TDB_PRIVATE_H +#define TDB_PRIVATE_H + /* + 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 <http://www.gnu.org/licenses/>. +*/ + +#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" + +/* #define TDB_TRACE 1 */ +#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_RECOVERY_INVALID_MAGIC (0x0) +#define TDB_HASH_RWLOCK_MAGIC (0xbad1a51U) +#define TDB_FEATURE_FLAG_MAGIC (0xbad1a52U) +#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->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 + +#define TDB_FEATURE_FLAG_MUTEX 0x00000001 + +#define TDB_SUPPORTED_FEATURE_FLAGS ( \ + TDB_FEATURE_FLAG_MUTEX | \ + 0) + +/* 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 + +#ifdef TDB_TRACE +void tdb_trace(struct tdb_context *tdb, const char *op); +void tdb_trace_seqnum(struct tdb_context *tdb, uint32_t seqnum, const char *op); +void tdb_trace_open(struct tdb_context *tdb, const char *op, + unsigned hash_size, unsigned tdb_flags, unsigned open_flags); +void tdb_trace_ret(struct tdb_context *tdb, const char *op, int ret); +void tdb_trace_retrec(struct tdb_context *tdb, const char *op, TDB_DATA ret); +void tdb_trace_1rec(struct tdb_context *tdb, const char *op, + TDB_DATA rec); +void tdb_trace_1rec_ret(struct tdb_context *tdb, const char *op, + TDB_DATA rec, int ret); +void tdb_trace_1rec_retrec(struct tdb_context *tdb, const char *op, + TDB_DATA rec, TDB_DATA ret); +void tdb_trace_2rec_flag_ret(struct tdb_context *tdb, const char *op, + TDB_DATA rec1, TDB_DATA rec2, unsigned flag, + int ret); +void tdb_trace_1plusn_rec_flag_ret(struct tdb_context *tdb, const char *op, + TDB_DATA rec, + const TDB_DATA *recs, int num_recs, + unsigned flag, int ret); +void tdb_trace_2rec_retrec(struct tdb_context *tdb, const char *op, + TDB_DATA rec1, TDB_DATA rec2, TDB_DATA ret); +#else +#define tdb_trace(tdb, op) +#define tdb_trace_seqnum(tdb, seqnum, op) +#define tdb_trace_open(tdb, op, hash_size, tdb_flags, open_flags) +#define tdb_trace_ret(tdb, op, ret) +#define tdb_trace_retrec(tdb, op, ret) +#define tdb_trace_1rec(tdb, op, rec) +#define tdb_trace_1rec_ret(tdb, op, rec, ret) +#define tdb_trace_1rec_retrec(tdb, op, rec, ret) +#define tdb_trace_2rec_flag_ret(tdb, op, rec1, rec2, flag, ret) +#define tdb_trace_1plusn_rec_flag_ret(tdb, op, rec, recs, num_recs, flag, ret); +#define tdb_trace_2rec_retrec(tdb, op, rec1, rec2, ret) +#endif /* !TDB_TRACE */ + +/* lock offsets */ +#define OPEN_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 + +/* + * Note: the BUCKET macro is broken as it returns an unexpected result when + * called as BUCKET(-1) for the freelist: + * + * -1 is sign converted to an unsigned int 4294967295 and then the modulo + * tdb->hashtable_size is computed. So with a hashtable_size of 10 the result + * is + * + * 4294967295 % hashtable_size = 5. + * + * where it should be -1 (C uses symmetric modulo). + * + * As all callers will lock the same wrong list consistently locking is still + * consistent. We can not change this without an incompatible on-disk format + * change, otherwise different tdb versions would use incompatible locking. + */ +#define BUCKET(hash) ((hash) % tdb->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 tdb_record for the free space + plus a separate data list for each hash value */ +struct tdb_record { + 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 */ + uint32_t magic1_hash; /* hash of TDB_MAGIC_FOOD. */ + uint32_t magic2_hash; /* hash of TDB_MAGIC. */ + uint32_t feature_flags; + tdb_len_t mutex_size; /* set if TDB_FEATURE_FLAG_MUTEX is set */ + tdb_off_t reserved[25]; +}; + +struct tdb_lock_type { + uint32_t off; + uint32_t count; + uint32_t ltype; +}; + +struct tdb_chainwalk_ctx { + tdb_off_t slow_ptr; + bool slow_chase; +}; + +struct tdb_traverse_lock { + struct tdb_traverse_lock *next; + uint32_t off; + uint32_t list; + int lock_rw; +}; + +void tdb_chainwalk_init(struct tdb_chainwalk_ctx *ctx, tdb_off_t ptr); +bool tdb_chainwalk_check(struct tdb_context *tdb, + struct tdb_chainwalk_ctx *ctx, + tdb_off_t next_ptr); + +enum tdb_lock_flags { + /* WAIT == F_SETLKW, NOWAIT == F_SETLK */ + TDB_LOCK_NOWAIT = 0, + TDB_LOCK_WAIT = 1, + /* If set, don't log an error on failure. */ + TDB_LOCK_PROBE = 2, + /* If set, don't actually lock at all. */ + TDB_LOCK_MARK_ONLY = 4, +}; + +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 , tdb_len_t, int ); + int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t ); +}; + +struct tdb_mutexes; + +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 allrecord_lock; /* .offset == upgradable */ + int num_lockrecs; + struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */ + int lockrecs_array_length; + + tdb_off_t hdr_ofs; /* this is 0 or header.mutex_size */ + struct tdb_mutexes *mutexes; /* mmap of the mutex area */ + + enum TDB_ERROR ecode; /* error code for last tdb error */ + uint32_t hash_size; + uint32_t feature_flags; + 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 */ + const struct tdb_methods *methods; + struct tdb_transaction *transaction; + int page_size; + int max_dead_records; +#ifdef TDB_TRACE + int tracefd; +#endif + volatile sig_atomic_t *interrupt_sig_ptr; +}; + + +/* + internal prototypes +*/ +int tdb_munmap(struct tdb_context *tdb); +int 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_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype, + enum tdb_lock_flags flags); +int tdb_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype, + bool mark_lock); +int tdb_unlock(struct tdb_context *tdb, int list, int ltype); +int tdb_brlock(struct tdb_context *tdb, + int rw_type, tdb_off_t offset, size_t len, + enum tdb_lock_flags flags); +int tdb_brunlock(struct tdb_context *tdb, + int rw_type, tdb_off_t offset, size_t len); +bool tdb_have_extra_locks(struct tdb_context *tdb); +void tdb_release_transaction_locks(struct tdb_context *tdb); +int tdb_transaction_lock(struct tdb_context *tdb, int ltype, + enum tdb_lock_flags lockflags); +int tdb_transaction_unlock(struct tdb_context *tdb, int ltype); +int tdb_recovery_area(struct tdb_context *tdb, + const struct tdb_methods *methods, + tdb_off_t *recovery_offset, + struct tdb_record *rec); +int tdb_allrecord_lock(struct tdb_context *tdb, int ltype, + enum tdb_lock_flags flags, bool upgradable); +int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype, bool mark_lock); +int tdb_allrecord_upgrade(struct tdb_context *tdb); +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 tdb_record *rec); +tdb_off_t tdb_allocate(struct tdb_context *tdb, int hash, tdb_len_t length, + struct tdb_record *rec); + +int _tdb_oob(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len, int probe); + +static inline int tdb_oob( + struct tdb_context *tdb, tdb_off_t off, tdb_len_t len, int probe) +{ + if (likely((off + len >= off) && (off + len <= tdb->map_size))) { + return 0; + } + return _tdb_oob(tdb, off, len, probe); +} + + +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); +bool tdb_needs_recovery(struct tdb_context *tdb); +int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *rec); +int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct tdb_record *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 tdb_record *rec); +tdb_off_t tdb_find_dead(struct tdb_context *tdb, uint32_t hash, + struct tdb_record *r, tdb_len_t length, + tdb_off_t *p_last_ptr); +int tdb_trim_dead(struct tdb_context *tdb, uint32_t hash); +void tdb_io_init(struct tdb_context *tdb); +int tdb_expand(struct tdb_context *tdb, tdb_off_t size); +tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size); +int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off, + struct tdb_record *rec); +bool tdb_write_all(int fd, const void *buf, size_t count); +int tdb_transaction_recover(struct tdb_context *tdb); +void tdb_header_hash(struct tdb_context *tdb, + uint32_t *magic1_hash, uint32_t *magic2_hash); +unsigned int tdb_old_hash(TDB_DATA *key); +size_t tdb_dead_space(struct tdb_context *tdb, tdb_off_t off); +bool tdb_add_off_t(tdb_off_t a, tdb_off_t b, tdb_off_t *pret); + +/* tdb_off_t and tdb_len_t right now are both uint32_t */ +#define tdb_add_len_t tdb_add_off_t + +size_t tdb_mutex_size(struct tdb_context *tdb); +bool tdb_have_mutexes(struct tdb_context *tdb); +int tdb_mutex_init(struct tdb_context *tdb); +int tdb_mutex_mmap(struct tdb_context *tdb); +int tdb_mutex_munmap(struct tdb_context *tdb); +bool tdb_mutex_lock(struct tdb_context *tdb, int rw, off_t off, off_t len, + bool waitflag, int *pret); +bool tdb_mutex_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len, + int *pret); +int tdb_mutex_allrecord_lock(struct tdb_context *tdb, int ltype, + enum tdb_lock_flags flags); +int tdb_mutex_allrecord_unlock(struct tdb_context *tdb); +int tdb_mutex_allrecord_upgrade(struct tdb_context *tdb); +void tdb_mutex_allrecord_downgrade(struct tdb_context *tdb); + +#endif /* TDB_PRIVATE_H */ |