diff options
Diffstat (limited to 'tdb/tdb.c')
| -rw-r--r-- | tdb/tdb.c | 2099 |
1 files changed, 0 insertions, 2099 deletions
diff --git a/tdb/tdb.c b/tdb/tdb.c deleted file mode 100644 index af475bb7ad..0000000000 --- a/tdb/tdb.c +++ /dev/null @@ -1,2099 +0,0 @@ - /* - Unix SMB/CIFS implementation. - Samba database functions - Copyright (C) Andrew Tridgell 1999-2000 - Copyright (C) Luke Kenneth Casson Leighton 2000 - Copyright (C) Paul `Rusty' Russell 2000 - Copyright (C) Jeremy Allison 2000-2003 - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program 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 General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. -*/ - - -/* NOTE: If you use tdbs under valgrind, and in particular if you run - * tdbtorture, you may get spurious "uninitialized value" warnings. I - * think this is because valgrind doesn't understand that the mmap'd - * area may be written to by other processes. Memory can, from the - * point of view of the grinded process, spontaneously become - * initialized. - * - * I can think of a few solutions. [mbp 20030311] - * - * 1 - Write suppressions for Valgrind so that it doesn't complain - * about this. Probably the most reasonable but people need to - * remember to use them. - * - * 2 - Use IO not mmap when running under valgrind. Not so nice. - * - * 3 - Use the special valgrind macros to mark memory as valid at the - * right time. Probably too hard -- the process just doesn't know. - */ - -/* udev defines */ -#define STANDALONE -#define TDB_DEBUG -#define HAVE_MMAP 1 -/* this should prevent deadlocks loops on corrupt databases - * we've discovered. Most deadlocks happend by iterating over the - * list of entries with the same hash value. */ -#define LOOP_MAX 100000 -#define TDB_LOG(x) TDB_LOG_UDEV x -#define TDB_LOG_UDEV(tdb, level, format, arg...) info(format, ##arg) - -#ifdef STANDALONE -#if HAVE_CONFIG_H -#include <config.h> -#endif - -#define _KLIBC_HAS_ARCH_SIG_ATOMIC_T -#include <stdlib.h> -#include <stdio.h> -#include <fcntl.h> -#include <unistd.h> -#include <string.h> -#include <fcntl.h> -#include <errno.h> -#include <sys/mman.h> -#include <sys/stat.h> -#include <signal.h> -#include "tdb.h" -#include "spinlock.h" -#include "../udev_lib.h" -#include "../logging.h" -#else -#include "includes.h" -#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_ALIGNMENT 4 -#define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT) -#define DEFAULT_HASH_SIZE 131 -#define TDB_PAGE_SIZE 0x2000 -#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)) - -/* NB assumes there is a local variable called "tdb" that is the - * current context, also takes doubly-parenthesized print-style - * argument. */ -#ifndef TDB_LOG -#define TDB_LOG(x) (tdb->log_fn?((tdb->log_fn x),0) : 0) -#endif - -/* lock offsets */ -#define GLOBAL_LOCK 0 -#define ACTIVE_LOCK 4 - -#ifndef MAP_FILE -#define MAP_FILE 0 -#endif - -#ifndef MAP_FAILED -#define MAP_FAILED ((void *)-1) -#endif - -/* 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) -TDB_DATA tdb_null; - -/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */ -static TDB_CONTEXT *tdbs = NULL; - -static int tdb_munmap(TDB_CONTEXT *tdb) -{ - if (tdb->flags & TDB_INTERNAL) - return 0; - -#ifdef HAVE_MMAP - if (tdb->map_ptr) { - int ret = munmap(tdb->map_ptr, tdb->map_size); - if (ret != 0) - return ret; - } -#endif - tdb->map_ptr = NULL; - return 0; -} - -static void tdb_mmap(TDB_CONTEXT *tdb) -{ - if (tdb->flags & TDB_INTERNAL) - return; - -#ifdef HAVE_MMAP - if (!(tdb->flags & TDB_NOMMAP)) { - tdb->map_ptr = mmap(NULL, tdb->map_size, - PROT_READ|(tdb->read_only? 0:PROT_WRITE), - MAP_SHARED|MAP_FILE, tdb->fd, 0); - - /* - * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!! - */ - - if (tdb->map_ptr == MAP_FAILED) { - tdb->map_ptr = NULL; - TDB_LOG((tdb, 2, "tdb_mmap failed for size %d (%s)\n", - tdb->map_size, strerror(errno))); - } - } else { - tdb->map_ptr = NULL; - } -#else - tdb->map_ptr = NULL; -#endif -} - -/* Endian conversion: we only ever deal with 4 byte quantities */ -static void *convert(void *buf, u32 size) -{ - u32 i, *p = buf; - for (i = 0; i < size / 4; i++) - p[i] = TDB_BYTEREV(p[i]); - return buf; -} -#define DOCONV() (tdb->flags & TDB_CONVERT) -#define CONVERT(x) (DOCONV() ? 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 next; /* offset of the next record in the list */ - tdb_len rec_len; /* total byte length of record */ - tdb_len key_len; /* byte length of key */ - tdb_len data_len; /* byte length of data */ - u32 full_hash; /* the full 32 bit hash of the key */ - u32 magic; /* try to catch errors */ - /* the following union is implied: - union { - char record[rec_len]; - struct { - char key[key_len]; - char data[data_len]; - } - u32 totalsize; (tailer) - } - */ -}; - -/*************************************************************** - Allow a caller to set a "alarm" flag that tdb can check to abort - a blocking lock on SIGALRM. -***************************************************************/ - -static sig_atomic_t *palarm_fired; - -void tdb_set_lock_alarm(sig_atomic_t *palarm) -{ - palarm_fired = palarm; -} - -/* a byte range locking function - return 0 on success - this functions locks/unlocks 1 byte at the specified offset. - - On error, errno is also set so that errors are passed back properly - through tdb_open(). */ -static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, - int rw_type, int lck_type, int probe) -{ - struct flock fl; - int ret; - - if (tdb->flags & TDB_NOLOCK) - return 0; - if ((rw_type == F_WRLCK) && (tdb->read_only)) { - errno = EACCES; - return -1; - } - - fl.l_type = rw_type; - fl.l_whence = SEEK_SET; - fl.l_start = offset; - fl.l_len = 1; - fl.l_pid = 0; - - do { - ret = fcntl(tdb->fd,lck_type,&fl); - if (ret == -1 && errno == EINTR && palarm_fired && *palarm_fired) - break; - } while (ret == -1 && errno == EINTR); - - if (ret == -1) { - if (!probe && lck_type != F_SETLK) { - /* Ensure error code is set for log fun to examine. */ - if (errno == EINTR && palarm_fired && *palarm_fired) - tdb->ecode = TDB_ERR_LOCK_TIMEOUT; - else - tdb->ecode = TDB_ERR_LOCK; - TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n", - tdb->fd, offset, rw_type, lck_type)); - } - /* Was it an alarm timeout ? */ - if (errno == EINTR && palarm_fired && *palarm_fired) - return TDB_ERRCODE(TDB_ERR_LOCK_TIMEOUT, -1); - /* Otherwise - generic lock error. */ - /* errno set by fcntl */ - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - return 0; -} - -/* lock a list in the database. list -1 is the alloc list */ -static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype) -{ - if (list < -1 || list >= (int)tdb->header.hash_size) { - TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n", - list, ltype)); - return -1; - } - if (tdb->flags & TDB_NOLOCK) - return 0; - - /* Since fcntl locks don't nest, we do a lock for the first one, - and simply bump the count for future ones */ - if (tdb->locked[list+1].count == 0) { - if (!tdb->read_only && tdb->header.rwlocks) { - if (tdb_spinlock(tdb, list, ltype)) { - TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list %d ltype=%d\n", - list, ltype)); - return -1; - } - } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) { - TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n", - list, ltype, strerror(errno))); - return -1; - } - tdb->locked[list+1].ltype = ltype; - } - tdb->locked[list+1].count++; - return 0; -} - -/* unlock the database: returns void because it's too late for errors. */ - /* changed to return int it may be interesting to know there - has been an error --simo */ -static int tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype) -{ - int ret = -1; - - if (tdb->flags & TDB_NOLOCK) - return 0; - - /* Sanity checks */ - if (list < -1 || list >= (int)tdb->header.hash_size) { - TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size)); - return ret; - } - - if (tdb->locked[list+1].count==0) { - TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n")); - return ret; - } - - if (tdb->locked[list+1].count == 1) { - /* Down to last nested lock: unlock underneath */ - if (!tdb->read_only && tdb->header.rwlocks) { - ret = tdb_spinunlock(tdb, list, ltype); - } else { - ret = tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0); - } - } else { - ret = 0; - } - tdb->locked[list+1].count--; - - if (ret) - TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n")); - return ret; -} - -/* This is based on the hash algorithm from gdbm */ -static u32 tdb_hash(TDB_DATA *key) -{ - u32 value; /* Used to compute the hash value. */ - u32 i; /* Used to cycle through random values. */ - - /* Set the initial value from the key size. */ - for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++) - value = (value + (key->dptr[i] << (i*5 % 24))); - - return (1103515243 * value + 12345); -} - -/* check for an out of bounds access - if it is out of bounds then - see if the database has been expanded by someone else and expand - if necessary - note that "len" is the minimum length needed for the db -*/ -static int tdb_oob(TDB_CONTEXT *tdb, tdb_off len, int probe) -{ - struct stat st; - if (len <= tdb->map_size) - return 0; - if (tdb->flags & TDB_INTERNAL) { - if (!probe) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, 0,"tdb_oob len %d beyond internal malloc size %d\n", - (int)len, (int)tdb->map_size)); - } - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - - if (fstat(tdb->fd, &st) == -1) - return TDB_ERRCODE(TDB_ERR_IO, -1); - - if (st.st_size < (size_t)len) { - if (!probe) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, 0,"tdb_oob len %d beyond eof at %d\n", - (int)len, (int)st.st_size)); - } - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - - /* Unmap, update size, remap */ - if (tdb_munmap(tdb) == -1) - return TDB_ERRCODE(TDB_ERR_IO, -1); - tdb->map_size = st.st_size; - tdb_mmap(tdb); - return 0; -} - -/* write a lump of data at a specified offset */ -static int tdb_write(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len) -{ - if (tdb_oob(tdb, off + len, 0) != 0) - return -1; - - if (tdb->map_ptr) - memcpy(off + (char *)tdb->map_ptr, buf, len); -#ifdef HAVE_PWRITE - else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) { -#else - else if (lseek(tdb->fd, off, SEEK_SET) != off - || write(tdb->fd, buf, len) != (ssize_t)len) { -#endif - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n", - off, len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - return 0; -} - -/* read a lump of data at a specified offset, maybe convert */ -static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv) -{ - if (tdb_oob(tdb, off + len, 0) != 0) - return -1; - - if (tdb->map_ptr) - memcpy(buf, off + (char *)tdb->map_ptr, len); -#ifdef HAVE_PREAD - else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) { -#else - else if (lseek(tdb->fd, off, SEEK_SET) != off - || read(tdb->fd, buf, len) != (ssize_t)len) { -#endif - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n", - off, len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - if (cv) - convert(buf, len); - return 0; -} - -/* read a lump of data, allocating the space for it */ -static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len) -{ - char *buf; - - if (!(buf = malloc(len))) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_OOM; - TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n", - len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_OOM, buf); - } - if (tdb_read(tdb, offset, buf, len, 0) == -1) { - SAFE_FREE(buf); - return NULL; - } - return buf; -} - -/* read/write a tdb_off */ -static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d) -{ - return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV()); -} -static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d) -{ - tdb_off off = *d; - return tdb_write(tdb, offset, CONVERT(off), sizeof(*d)); -} - -/* read/write a record */ -static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) -{ - if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1) - return -1; - if (TDB_BAD_MAGIC(rec)) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_CORRUPT; - TDB_LOG((tdb, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - return tdb_oob(tdb, rec->next+sizeof(*rec), 0); -} -static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) -{ - struct list_struct r = *rec; - return tdb_write(tdb, offset, CONVERT(r), sizeof(r)); -} - -/* read a freelist record and check for simple errors */ -static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec) -{ - if (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1) - return -1; - - if (rec->magic == TDB_MAGIC) { - /* this happens when a app is showdown while deleting a record - we should - not completely fail when this happens */ - TDB_LOG((tdb, 0,"rec_free_read non-free magic 0x%x at offset=%d - fixing\n", - rec->magic, off)); - rec->magic = TDB_FREE_MAGIC; - if (tdb_write(tdb, off, rec, sizeof(*rec)) == -1) - return -1; - } - - if (rec->magic != TDB_FREE_MAGIC) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_CORRUPT; - TDB_LOG((tdb, 0,"rec_free_read bad magic 0x%x at offset=%d\n", - rec->magic, off)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0) - return -1; - return 0; -} - -/* update a record tailer (must hold allocation lock) */ -static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset, - const struct list_struct *rec) -{ - tdb_off totalsize; - - /* Offset of tailer from record header */ - totalsize = sizeof(*rec) + rec->rec_len; - return ofs_write(tdb, offset + totalsize - sizeof(tdb_off), - &totalsize); -} - -static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset) -{ - struct list_struct rec; - tdb_off tailer_ofs, tailer; - - if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) { - printf("ERROR: failed to read record at %u\n", offset); - return 0; - } - - printf(" rec: offset=%u next=%d rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n", - offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic); - - tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off); - if (ofs_read(tdb, tailer_ofs, &tailer) == -1) { - printf("ERROR: failed to read tailer at %u\n", tailer_ofs); - return rec.next; - } - - if (tailer != rec.rec_len + sizeof(rec)) { - printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n", - (unsigned)tailer, (unsigned)(rec.rec_len + sizeof(rec))); - } - return rec.next; -} - -static int tdb_dump_chain(TDB_CONTEXT *tdb, int i) -{ - tdb_off rec_ptr, top; - - top = TDB_HASH_TOP(i); - - if (tdb_lock(tdb, i, F_WRLCK) != 0) - return -1; - - if (ofs_read(tdb, top, &rec_ptr) == -1) - return tdb_unlock(tdb, i, F_WRLCK); - - if (rec_ptr) - printf("hash=%d\n", i); - - while (rec_ptr) { - rec_ptr = tdb_dump_record(tdb, rec_ptr); - } - - return tdb_unlock(tdb, i, F_WRLCK); -} - -void tdb_dump_all(TDB_CONTEXT *tdb) -{ - int i; - for (i=0;i<tdb->header.hash_size;i++) { - tdb_dump_chain(tdb, i); - } - printf("freelist:\n"); - tdb_dump_chain(tdb, -1); -} - -int tdb_printfreelist(TDB_CONTEXT *tdb) -{ - int ret; - long total_free = 0; - tdb_off offset, rec_ptr; - struct list_struct rec; - - if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0) - return ret; - - offset = FREELIST_TOP; - - /* read in the freelist top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - } - - printf("freelist top=[0x%08x]\n", rec_ptr ); - while (rec_ptr) { - if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) { - tdb_unlock(tdb, -1, F_WRLCK); - return -1; - } - - if (rec.magic != TDB_FREE_MAGIC) { - printf("bad magic 0x%08x in free list\n", rec.magic); - tdb_unlock(tdb, -1, F_WRLCK); - return -1; - } - - printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)]\n", rec.next, rec.rec_len, rec.rec_len ); - total_free += rec.rec_len; - - /* move to the next record */ - rec_ptr = rec.next; - } - printf("total rec_len = [0x%08x (%d)]\n", (int)total_free, - (int)total_free); - - return tdb_unlock(tdb, -1, F_WRLCK); -} - -/* Remove an element from the freelist. Must have alloc lock. */ -static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next) -{ - tdb_off last_ptr, i; - int maxloop; - - /* read in the freelist top */ - maxloop = LOOP_MAX; - last_ptr = FREELIST_TOP; - while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) { - if (i == off) { - /* We've found it! */ - return ofs_write(tdb, last_ptr, &next); - } - /* Follow chain (next offset is at start of record) */ - last_ptr = i; - - maxloop--; - if (maxloop == 0) { - TDB_LOG((tdb, 0, "remove_from_freelist: maxloop reached; corrupt database!\n")); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - } - TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); -} - -/* Add an element into the freelist. Merge adjacent records if - neccessary. */ -static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) -{ - tdb_off right, left; - - /* Allocation and tailer lock */ - if (tdb_lock(tdb, -1, F_WRLCK) != 0) - return -1; - - /* set an initial tailer, so if we fail we don't leave a bogus record */ - if (update_tailer(tdb, offset, rec) != 0) { - TDB_LOG((tdb, 0, "tdb_free: upfate_tailer failed!\n")); - goto fail; - } - - /* Look right first (I'm an Australian, dammit) */ - right = offset + sizeof(*rec) + rec->rec_len; - if (right + sizeof(*rec) <= tdb->map_size) { - struct list_struct r; - - if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) { - TDB_LOG((tdb, 0, "tdb_free: right read failed at %u\n", right)); - goto left; - } - - /* If it's free, expand to include it. */ - if (r.magic == TDB_FREE_MAGIC) { - if (remove_from_freelist(tdb, right, r.next) == -1) { - TDB_LOG((tdb, 0, "tdb_free: right free failed at %u\n", right)); - goto left; - } - rec->rec_len += sizeof(r) + r.rec_len; - } - } - -left: - /* Look left */ - left = offset - sizeof(tdb_off); - if (left > TDB_HASH_TOP(tdb->header.hash_size-1)) { - struct list_struct l; - tdb_off leftsize; - - /* Read in tailer and jump back to header */ - if (ofs_read(tdb, left, &leftsize) == -1) { - TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left)); - goto update; - } - left = offset - leftsize; - - /* Now read in record */ - if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) { - TDB_LOG((tdb, 0, "tdb_free: left read failed at %u (%u)\n", left, leftsize)); - goto update; - } - - /* If it's free, expand to include it. */ - if (l.magic == TDB_FREE_MAGIC) { - if (remove_from_freelist(tdb, left, l.next) == -1) { - TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left)); - goto update; - } else { - offset = left; - rec->rec_len += leftsize; - } - } - } - -update: - if (update_tailer(tdb, offset, rec) == -1) { - TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset)); - goto fail; - } - - /* Now, prepend to free list */ - rec->magic = TDB_FREE_MAGIC; - - if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 || - rec_write(tdb, offset, rec) == -1 || - ofs_write(tdb, FREELIST_TOP, &offset) == -1) { - TDB_LOG((tdb, 0, "tdb_free record write failed at offset=%d\n", offset)); - goto fail; - } - - /* And we're done. */ - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - - fail: - tdb_unlock(tdb, -1, F_WRLCK); - return -1; -} - - -/* expand a file. we prefer to use ftruncate, as that is what posix - says to use for mmap expansion */ -static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition) -{ - char buf[1024]; -#if HAVE_FTRUNCATE_EXTEND - if (ftruncate(tdb->fd, size+addition) != 0) { - TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n", - size+addition, strerror(errno))); - return -1; - } -#else - char b = 0; - -#ifdef HAVE_PWRITE - if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) { -#else - if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 || - write(tdb->fd, &b, 1) != 1) { -#endif - TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n", - size+addition, strerror(errno))); - return -1; - } -#endif - - /* now fill the file with something. This ensures that the file isn't sparse, which would be - very bad if we ran out of disk. This must be done with write, not via mmap */ - memset(buf, 0x42, sizeof(buf)); - while (addition) { - int n = addition>sizeof(buf)?sizeof(buf):addition; -#ifdef HAVE_PWRITE - int ret = pwrite(tdb->fd, buf, n, size); -#else - int ret; - if (lseek(tdb->fd, size, SEEK_SET) != size) - return -1; - ret = write(tdb->fd, buf, n); -#endif - if (ret != n) { - TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n", - n, strerror(errno))); - return -1; - } - addition -= n; - size += n; - } - return 0; -} - - -/* expand the database at least size bytes by expanding the underlying - file and doing the mmap again if necessary */ -static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size) -{ - struct list_struct rec; - tdb_off offset; - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) { - TDB_LOG((tdb, 0, "lock failed in tdb_expand\n")); - return -1; - } - - /* must know about any previous expansions by another process */ - tdb_oob(tdb, tdb->map_size + 1, 1); - - /* always make room for at least 10 more records, and round - the database up to a multiple of TDB_PAGE_SIZE */ - size = TDB_ALIGN(tdb->map_size + size*10, TDB_PAGE_SIZE) - tdb->map_size; - - if (!(tdb->flags & TDB_INTERNAL)) - tdb_munmap(tdb); - - /* - * We must ensure the file is unmapped before doing this - * to ensure consistency with systems like OpenBSD where - * writes and mmaps are not consistent. - */ - - /* expand the file itself */ - if (!(tdb->flags & TDB_INTERNAL)) { - if (expand_file(tdb, tdb->map_size, size) != 0) - goto fail; - } - - tdb->map_size += size; - - if (tdb->flags & TDB_INTERNAL) - tdb->map_ptr = realloc(tdb->map_ptr, tdb->map_size); - else { - /* - * We must ensure the file is remapped before adding the space - * to ensure consistency with systems like OpenBSD where - * writes and mmaps are not consistent. - */ - - /* We're ok if the mmap fails as we'll fallback to read/write */ - tdb_mmap(tdb); - } - - /* form a new freelist record */ - memset(&rec,'\0',sizeof(rec)); - rec.rec_len = size - sizeof(rec); - - /* link it into the free list */ - offset = tdb->map_size - size; - if (tdb_free(tdb, offset, &rec) == -1) - goto fail; - - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - fail: - tdb_unlock(tdb, -1, F_WRLCK); - return -1; -} - -/* allocate some space from the free list. The offset returned points - to a unconnected list_struct within the database with room for at - least length bytes of total data - - 0 is returned if the space could not be allocated - */ -static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length, - struct list_struct *rec) -{ - tdb_off rec_ptr, last_ptr, newrec_ptr; - struct list_struct newrec; - int maxloop; - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) - return 0; - - /* Extra bytes required for tailer */ - length += sizeof(tdb_off); - - again: - last_ptr = FREELIST_TOP; - - /* read in the freelist top */ - if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) - goto fail; - - /* keep looking until we find a freelist record big enough */ - maxloop = LOOP_MAX; - while (rec_ptr) { - if (rec_free_read(tdb, rec_ptr, rec) == -1) - goto fail; - - if (rec->rec_len >= length) { - /* found it - now possibly split it up */ - if (rec->rec_len > length + MIN_REC_SIZE) { - /* Length of left piece */ - length = TDB_ALIGN(length, TDB_ALIGNMENT); - - /* Right piece to go on free list */ - newrec.rec_len = rec->rec_len - - (sizeof(*rec) + length); - newrec_ptr = rec_ptr + sizeof(*rec) + length; - - /* And left record is shortened */ - rec->rec_len = length; - } else - newrec_ptr = 0; - - /* Remove allocated record from the free list */ - if (ofs_write(tdb, last_ptr, &rec->next) == -1) - goto fail; - - /* Update header: do this before we drop alloc - lock, otherwise tdb_free() might try to - merge with us, thinking we're free. - (Thanks Jeremy Allison). */ - rec->magic = TDB_MAGIC; - if (rec_write(tdb, rec_ptr, rec) == -1) - goto fail; - - /* Did we create new block? */ - if (newrec_ptr) { - /* Update allocated record tailer (we - shortened it). */ - if (update_tailer(tdb, rec_ptr, rec) == -1) - goto fail; - - /* Free new record */ - if (tdb_free(tdb, newrec_ptr, &newrec) == -1) - goto fail; - } - - /* all done - return the new record offset */ - tdb_unlock(tdb, -1, F_WRLCK); - return rec_ptr; - } - /* move to the next record */ - last_ptr = rec_ptr; - rec_ptr = rec->next; - - maxloop--; - if (maxloop == 0) { - TDB_LOG((tdb, 0, "tdb_allocate: maxloop reached; corrupt database!\n")); - return TDB_ERRCODE(TDB_ERR_CORRUPT, 0); - } - } - /* we didn't find enough space. See if we can expand the - database and if we can then try again */ - if (tdb_expand(tdb, length + sizeof(*rec)) == 0) - goto again; - fail: - tdb_unlock(tdb, -1, F_WRLCK); - return 0; -} - -/* initialise a new database with a specified hash size */ -static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size) -{ - struct tdb_header *newdb; - int size, ret = -1; - - /* We make it up in memory, then write it out if not internal */ - size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off); - if (!(newdb = calloc(size, 1))) - return TDB_ERRCODE(TDB_ERR_OOM, -1); - - /* Fill in the header */ - newdb->version = TDB_VERSION; - newdb->hash_size = hash_size; -#ifdef USE_SPINLOCKS - newdb->rwlocks = size; -#endif - if (tdb->flags & TDB_INTERNAL) { - tdb->map_size = size; - tdb->map_ptr = (char *)newdb; - memcpy(&tdb->header, newdb, sizeof(tdb->header)); - /* Convert the `ondisk' version if asked. */ - CONVERT(*newdb); - return 0; - } - if (lseek(tdb->fd, 0, SEEK_SET) == -1) - goto fail; - - if (ftruncate(tdb->fd, 0) == -1) - goto fail; - - /* This creates an endian-converted header, as if read from disk */ - CONVERT(*newdb); - memcpy(&tdb->header, newdb, sizeof(tdb->header)); - /* Don't endian-convert the magic food! */ - memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1); - if (write(tdb->fd, newdb, size) != size) - ret = -1; - else - ret = tdb_create_rwlocks(tdb->fd, hash_size); - - fail: - SAFE_FREE(newdb); - return ret; -} - -/* Returns 0 on fail. On success, return offset of record, and fills - in rec */ -static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, - struct list_struct *r) -{ - tdb_off rec_ptr; - int maxloop; - - /* read in the hash top */ - if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) - return 0; - - /* keep looking until we find the right record */ - maxloop = LOOP_MAX; - while (rec_ptr) { - if (rec_read(tdb, rec_ptr, r) == -1) - return 0; - - if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) { - char *k; - /* a very likely hit - read the key */ - k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r), - r->key_len); - if (!k) - return 0; - - if (memcmp(key.dptr, k, key.dsize) == 0) { - SAFE_FREE(k); - return rec_ptr; - } - SAFE_FREE(k); - } - rec_ptr = r->next; - - maxloop--; - if (maxloop == 0) { - TDB_LOG((tdb, 0, "tdb_find maxloop reached; corrupt database!\n")); - return TDB_ERRCODE(TDB_ERR_CORRUPT, 0); - } - } - return TDB_ERRCODE(TDB_ERR_NOEXIST, 0); -} - -/* If they do lockkeys, check that this hash is one they locked */ -static int tdb_keylocked(TDB_CONTEXT *tdb, u32 hash) -{ - u32 i; - if (!tdb->lockedkeys) - return 1; - for (i = 0; i < tdb->lockedkeys[0]; i++) - if (tdb->lockedkeys[i+1] == hash) - return 1; - return TDB_ERRCODE(TDB_ERR_NOLOCK, 0); -} - -/* As tdb_find, but if you succeed, keep the lock */ -static tdb_off tdb_find_lock(TDB_CONTEXT *tdb, TDB_DATA key, int locktype, - struct list_struct *rec) -{ - u32 hash, rec_ptr; - - hash = tdb_hash(&key); - if (!tdb_keylocked(tdb, hash)) - return 0; - if (tdb_lock(tdb, BUCKET(hash), locktype) == -1) - return 0; - if (!(rec_ptr = tdb_find(tdb, key, hash, rec))) - tdb_unlock(tdb, BUCKET(hash), locktype); - return rec_ptr; -} - -enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb) -{ - return tdb->ecode; -} - -static struct tdb_errname { - enum TDB_ERROR ecode; const char *estring; -} emap[] = { {TDB_SUCCESS, "Success"}, - {TDB_ERR_CORRUPT, "Corrupt database"}, - {TDB_ERR_IO, "IO Error"}, - {TDB_ERR_LOCK, "Locking error"}, - {TDB_ERR_OOM, "Out of memory"}, - {TDB_ERR_EXISTS, "Record exists"}, - {TDB_ERR_NOLOCK, "Lock exists on other keys"}, - {TDB_ERR_NOEXIST, "Record does not exist"} }; - -/* Error string for the last tdb error */ -const char *tdb_errorstr(TDB_CONTEXT *tdb) -{ - u32 i; - for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++) - if (tdb->ecode == emap[i].ecode) - return emap[i].estring; - return "Invalid error code"; -} - -/* update an entry in place - this only works if the new data size - is <= the old data size and the key exists. - on failure return -1. -*/ - -static int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) -{ - struct list_struct rec; - tdb_off rec_ptr; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec))) - return -1; - - /* must be long enough key, data and tailer */ - if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) { - tdb->ecode = TDB_SUCCESS; /* Not really an error */ - return -1; - } - - if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len, - dbuf.dptr, dbuf.dsize) == -1) - return -1; - - if (dbuf.dsize != rec.data_len) { - /* update size */ - rec.data_len = dbuf.dsize; - return rec_write(tdb, rec_ptr, &rec); - } - - return 0; -} - -/* find an entry in the database given a key */ -/* If an entry doesn't exist tdb_err will be set to - * TDB_ERR_NOEXIST. If a key has no data attached - * tdb_err will not be set. Both will return a - * zero pptr and zero dsize. - */ - -TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) -{ - tdb_off rec_ptr; - struct list_struct rec; - TDB_DATA ret; - - /* find which hash bucket it is in */ - if (!(rec_ptr = tdb_find_lock(tdb,key,F_RDLCK,&rec))) - return tdb_null; - - if (rec.data_len) - ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, - rec.data_len); - else - ret.dptr = NULL; - ret.dsize = rec.data_len; - tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); - return ret; -} - -/* check if an entry in the database exists - - note that 1 is returned if the key is found and 0 is returned if not found - this doesn't match the conventions in the rest of this module, but is - compatible with gdbm -*/ -int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) -{ - struct list_struct rec; - - if (tdb_find_lock(tdb, key, F_RDLCK, &rec) == 0) - return 0; - tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); - return 1; -} - -/* record lock stops delete underneath */ -static int lock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 0; -} -/* - Write locks override our own fcntl readlocks, so check it here. - Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not - an error to fail to get the lock here. -*/ - -static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - struct tdb_traverse_lock *i; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - return -1; - return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1); -} - -/* - Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not - an error to fail to get the lock here. -*/ - -static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0); -} -/* fcntl locks don't stack: avoid unlocking someone else's */ -static int unlock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - struct tdb_traverse_lock *i; - u32 count = 0; - - if (off == 0) - return 0; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - count++; - return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0); -} - -/* actually delete an entry in the database given the offset */ -static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec) -{ - tdb_off last_ptr, i; - struct list_struct lastrec; - int maxloop; - - if (tdb->read_only) return -1; - - if (write_lock_record(tdb, rec_ptr) == -1) { - /* Someone traversing here: mark it as dead */ - rec->magic = TDB_DEAD_MAGIC; - return rec_write(tdb, rec_ptr, rec); - } - if (write_unlock_record(tdb, rec_ptr) != 0) - return -1; - - /* find previous record in hash chain */ - if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1) - return -1; - - maxloop = LOOP_MAX; - for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next) { - if (rec_read(tdb, i, &lastrec) == -1) - return -1; - - maxloop--; - if (maxloop == 0) { - TDB_LOG((tdb, 0, "(tdb)do_delete: maxloop reached; corrupt database!\n")); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - } - - /* unlink it: next ptr is at start of record. */ - if (last_ptr == 0) - last_ptr = TDB_HASH_TOP(rec->full_hash); - if (ofs_write(tdb, last_ptr, &rec->next) == -1) - return -1; - - /* recover the space */ - if (tdb_free(tdb, rec_ptr, rec) == -1) - return -1; - return 0; -} - -/* Uses traverse lock: 0 = finish, -1 = error, other = record offset */ -static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock, - struct list_struct *rec) -{ - int want_next = (tlock->off != 0); - - /* No traversal allows if you've called tdb_lockkeys() */ - if (tdb->lockedkeys) - return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - - /* Lock each chain from the start one. */ - for (; tlock->hash < tdb->header.hash_size; tlock->hash++) { - if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1) - return -1; - - /* No previous record? Start at top of chain. */ - if (!tlock->off) { - if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash), - &tlock->off) == -1) - goto fail; - } else { - /* Otherwise unlock the previous record. */ - if (unlock_record(tdb, tlock->off) != 0) - goto fail; - } - - if (want_next) { - /* We have offset of old record: grab next */ - if (rec_read(tdb, tlock->off, rec) == -1) - goto fail; - tlock->off = rec->next; - } - - /* Iterate through chain */ - while( tlock->off) { - tdb_off current; - if (rec_read(tdb, tlock->off, rec) == -1) - goto fail; - if (!TDB_DEAD(rec)) { - /* Woohoo: we found one! */ - if (lock_record(tdb, tlock->off) != 0) - goto fail; - return tlock->off; - } - /* Try to clean dead ones from old traverses */ - current = tlock->off; - tlock->off = rec->next; - if (!tdb->read_only && - do_delete(tdb, current, rec) != 0) - goto fail; - } - tdb_unlock(tdb, tlock->hash, F_WRLCK); - want_next = 0; - } - /* We finished iteration without finding anything */ - return TDB_ERRCODE(TDB_SUCCESS, 0); - - fail: - tlock->off = 0; - if (tdb_unlock(tdb, tlock->hash, F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_next_lock: On error unlock failed!\n")); - return -1; -} - -/* traverse the entire database - calling fn(tdb, key, data) on each element. - return -1 on error or the record count traversed - if fn is NULL then it is not called - a non-zero return value from fn() indicates that the traversal should stop - */ -int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *state) -{ - TDB_DATA key, dbuf; - struct list_struct rec; - struct tdb_traverse_lock tl = { NULL, 0, 0 }; - int ret, count = 0; - - /* This was in the initializaton, above, but the IRIX compiler - * did not like it. crh - */ - tl.next = tdb->travlocks.next; - - /* fcntl locks don't stack: beware traverse inside traverse */ - tdb->travlocks.next = &tl; - - /* tdb_next_lock places locks on the record returned, and its chain */ - while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) { - count++; - /* now read the full record */ - key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec), - rec.key_len + rec.data_len); - if (!key.dptr) { - ret = -1; - if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) - goto out; - if (unlock_record(tdb, tl.off) != 0) - TDB_LOG((tdb, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n")); - goto out; - } - key.dsize = rec.key_len; - dbuf.dptr = key.dptr + rec.key_len; - dbuf.dsize = rec.data_len; - - /* Drop chain lock, call out */ - if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) { - ret = -1; - goto out; - } - if (fn && fn(tdb, key, dbuf, state)) { - /* They want us to terminate traversal */ - ret = count; - if (unlock_record(tdb, tl.off) != 0) { - TDB_LOG((tdb, 0, "tdb_traverse: unlock_record failed!\n"));; - ret = -1; - } - tdb->travlocks.next = tl.next; - SAFE_FREE(key.dptr); - return count; - } - SAFE_FREE(key.dptr); - } -out: - tdb->travlocks.next = tl.next; - if (ret < 0) - return -1; - else - return count; -} - -/* find the first entry in the database and return its key */ -TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb) -{ - TDB_DATA key; - struct list_struct rec; - - /* release any old lock */ - if (unlock_record(tdb, tdb->travlocks.off) != 0) - return tdb_null; - tdb->travlocks.off = tdb->travlocks.hash = 0; - - if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0) - return tdb_null; - /* now read the key */ - key.dsize = rec.key_len; - key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize); - if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n")); - return key; -} - -/* find the next entry in the database, returning its key */ -TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey) -{ - u32 oldhash; - TDB_DATA key = tdb_null; - struct list_struct rec; - char *k = NULL; - - /* Is locked key the old key? If so, traverse will be reliable. */ - if (tdb->travlocks.off) { - if (tdb_lock(tdb,tdb->travlocks.hash,F_WRLCK)) - return tdb_null; - if (rec_read(tdb, tdb->travlocks.off, &rec) == -1 - || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec), - rec.key_len)) - || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) { - /* No, it wasn't: unlock it and start from scratch */ - if (unlock_record(tdb, tdb->travlocks.off) != 0) - return tdb_null; - if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0) - return tdb_null; - tdb->travlocks.off = 0; - } - - SAFE_FREE(k); - } - - if (!tdb->travlocks.off) { - /* No previous element: do normal find, and lock record */ - tdb->travlocks.off = tdb_find_lock(tdb, oldkey, F_WRLCK, &rec); - if (!tdb->travlocks.off) - return tdb_null; - tdb->travlocks.hash = BUCKET(rec.full_hash); - if (lock_record(tdb, tdb->travlocks.off) != 0) { - TDB_LOG((tdb, 0, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno))); - return tdb_null; - } - } - oldhash = tdb->travlocks.hash; - - /* Grab next record: locks chain and returned record, - unlocks old record */ - if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) { - key.dsize = rec.key_len; - key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec), - key.dsize); - /* Unlock the chain of this new record */ - if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); - } - /* Unlock the chain of old record */ - if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); - return key; -} - -/* delete an entry in the database given a key */ -int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) -{ - tdb_off rec_ptr; - struct list_struct rec; - int ret; - - if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec))) - return -1; - ret = do_delete(tdb, rec_ptr, &rec); - if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_delete: WARNING tdb_unlock failed!\n")); - return ret; -} - -/* store an element in the database, replacing any existing element - with the same key - - return 0 on success, -1 on failure -*/ -int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) -{ - struct list_struct rec; - u32 hash; - tdb_off rec_ptr; - char *p = NULL; - int ret = 0; - - /* find which hash bucket it is in */ - hash = tdb_hash(&key); - if (!tdb_keylocked(tdb, hash)) - return -1; - if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) - return -1; - - /* check for it existing, on insert. */ - if (flag == TDB_INSERT) { - if (tdb_exists(tdb, key)) { - tdb->ecode = TDB_ERR_EXISTS; - goto fail; - } - } else { - /* first try in-place update, on modify or replace. */ - if (tdb_update(tdb, key, dbuf) == 0) - goto out; - if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST) - goto fail; - } - /* reset the error code potentially set by the tdb_update() */ - tdb->ecode = TDB_SUCCESS; - - /* delete any existing record - if it doesn't exist we don't - care. Doing this first reduces fragmentation, and avoids - coalescing with `allocated' block before it's updated. */ - if (flag != TDB_INSERT) - tdb_delete(tdb, key); - - /* Copy key+value *before* allocating free space in case malloc - fails and we are left with a dead spot in the tdb. */ - - if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) { - tdb->ecode = TDB_ERR_OOM; - goto fail; - } - - memcpy(p, key.dptr, key.dsize); - if (dbuf.dsize) - memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize); - - /* now we're into insert / modify / replace of a record which - * we know could not be optimised by an in-place store (for - * various reasons). */ - if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec))) - goto fail; - - /* Read hash top into next ptr */ - if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) - goto fail; - - rec.key_len = key.dsize; - rec.data_len = dbuf.dsize; - rec.full_hash = hash; - rec.magic = TDB_MAGIC; - - /* write out and point the top of the hash chain at it */ - if (rec_write(tdb, rec_ptr, &rec) == -1 - || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1 - || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { - /* Need to tdb_unallocate() here */ - goto fail; - } - out: - SAFE_FREE(p); - tdb_unlock(tdb, BUCKET(hash), F_WRLCK); - return ret; -fail: - ret = -1; - goto out; -} - -/* Attempt to append data to an entry in place - this only works if the new data size - is <= the old data size and the key exists. - on failure return -1. Record must be locked before calling. -*/ -static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) -{ - struct list_struct rec; - tdb_off rec_ptr; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec))) - return -1; - - /* Append of 0 is always ok. */ - if (new_dbuf.dsize == 0) - return 0; - - /* must be long enough for key, old data + new data and tailer */ - if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) { - /* No room. */ - tdb->ecode = TDB_SUCCESS; /* Not really an error */ - return -1; - } - - if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len, - new_dbuf.dptr, new_dbuf.dsize) == -1) - return -1; - - /* update size */ - rec.data_len += new_dbuf.dsize; - return rec_write(tdb, rec_ptr, &rec); -} - -/* Append to an entry. Create if not exist. */ - -int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) -{ - struct list_struct rec; - u32 hash; - tdb_off rec_ptr; - char *p = NULL; - int ret = 0; - size_t new_data_size = 0; - - /* find which hash bucket it is in */ - hash = tdb_hash(&key); - if (!tdb_keylocked(tdb, hash)) - return -1; - if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) - return -1; - - /* first try in-place. */ - if (tdb_append_inplace(tdb, key, new_dbuf) == 0) - goto out; - - /* reset the error code potentially set by the tdb_append_inplace() */ - tdb->ecode = TDB_SUCCESS; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) { - if (tdb->ecode != TDB_ERR_NOEXIST) - goto fail; - - /* Not found - create. */ - - ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT); - goto out; - } - - new_data_size = rec.data_len + new_dbuf.dsize; - - /* Copy key+old_value+value *before* allocating free space in case malloc - fails and we are left with a dead spot in the tdb. */ - - if (!(p = (char *)malloc(key.dsize + new_data_size))) { - tdb->ecode = TDB_ERR_OOM; - goto fail; - } - - /* Copy the key in place. */ - memcpy(p, key.dptr, key.dsize); - - /* Now read the old data into place. */ - if (rec.data_len && - tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1) - goto fail; - - /* Finally append the new data. */ - if (new_dbuf.dsize) - memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize); - - /* delete any existing record - if it doesn't exist we don't - care. Doing this first reduces fragmentation, and avoids - coalescing with `allocated' block before it's updated. */ - - tdb_delete(tdb, key); - - if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec))) - goto fail; - - /* Read hash top into next ptr */ - if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) - goto fail; - - rec.key_len = key.dsize; - rec.data_len = new_data_size; - rec.full_hash = hash; - rec.magic = TDB_MAGIC; - - /* write out and point the top of the hash chain at it */ - if (rec_write(tdb, rec_ptr, &rec) == -1 - || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1 - || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { - /* Need to tdb_unallocate() here */ - goto fail; - } - - out: - SAFE_FREE(p); - tdb_unlock(tdb, BUCKET(hash), F_WRLCK); - return ret; - -fail: - ret = -1; - goto out; -} - -static int tdb_already_open(dev_t device, - ino_t ino) -{ - TDB_CONTEXT *i; - - for (i = tdbs; i; i = i->next) { - if (i->device == device && i->inode == ino) { - return 1; - } - } - - return 0; -} - -/* open the database, creating it if necessary - - The open_flags and mode are passed straight to the open call on the - database file. A flags value of O_WRONLY is invalid. The hash size - is advisory, use zero for a default value. - - Return is NULL on error, in which case errno is also set. Don't - try to call tdb_error or tdb_errname, just do strerror(errno). - - @param name may be NULL for internal databases. */ -TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode) -{ - return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL); -} - - -TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode, - tdb_log_func log_fn) -{ - TDB_CONTEXT *tdb; - struct stat st; - int rev = 0, locked; - unsigned char *vp; - u32 vertest; - - if (!(tdb = calloc(1, sizeof *tdb))) { - /* Can't log this */ - errno = ENOMEM; - goto fail; - } - tdb->fd = -1; - tdb->name = NULL; - tdb->map_ptr = NULL; - tdb->lockedkeys = NULL; - tdb->flags = tdb_flags; - tdb->open_flags = open_flags; - tdb->log_fn = log_fn; - - if ((open_flags & O_ACCMODE) == O_WRONLY) { - TDB_LOG((tdb, 0, "tdb_open_ex: can't open tdb %s write-only\n", - name)); - errno = EINVAL; - goto fail; - } - - if (hash_size == 0) - hash_size = DEFAULT_HASH_SIZE; - if ((open_flags & O_ACCMODE) == O_RDONLY) { - tdb->read_only = 1; - /* read only databases don't do locking or clear if first */ - tdb->flags |= TDB_NOLOCK; - tdb->flags &= ~TDB_CLEAR_IF_FIRST; - } - - /* internal databases don't mmap or lock, and start off cleared */ - if (tdb->flags & TDB_INTERNAL) { - tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP); - tdb->flags &= ~TDB_CLEAR_IF_FIRST; - if (tdb_new_database(tdb, hash_size) != 0) { - TDB_LOG((tdb, 0, "tdb_open_ex: tdb_new_database failed!")); - goto fail; - } - goto internal; - } - - if ((tdb->fd = open(name, open_flags, mode)) == -1) { - TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by open(2) */ - } - - /* - Close file when execing another process. - Prevents SELinux access errors. - */ - set_cloexec_flag(tdb->fd, 1); - - /* ensure there is only one process initialising at once */ - if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) { - TDB_LOG((tdb, 0, "tdb_open_ex: failed to get global lock on %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by tdb_brlock */ - } - - /* we need to zero database if we are the only one with it open */ - if ((locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0)) - && (tdb_flags & TDB_CLEAR_IF_FIRST)) { - open_flags |= O_CREAT; - if (ftruncate(tdb->fd, 0) == -1) { - TDB_LOG((tdb, 0, "tdb_open_ex: " - "failed to truncate %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by ftruncate */ - } - } - - if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header) - || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0 - || (tdb->header.version != TDB_VERSION - && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) { - /* its not a valid database - possibly initialise it */ - if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) { - errno = EIO; /* ie bad format or something */ - goto fail; - } - rev = (tdb->flags & TDB_CONVERT); - } - vp = (unsigned char *)&tdb->header.version; - vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) | - (((u32)vp[2]) << 8) | (u32)vp[3]; - tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0; - if (!rev) - tdb->flags &= ~TDB_CONVERT; - else { - tdb->flags |= TDB_CONVERT; - convert(&tdb->header, sizeof(tdb->header)); - } - if (fstat(tdb->fd, &st) == -1) - goto fail; - - /* Is it already in the open list? If so, fail. */ - if (tdb_already_open(st.st_dev, st.st_ino)) { - TDB_LOG((tdb, 2, "tdb_open_ex: " - "%s (%d:%d,%lld) is already open in this process\n", - name, major(st.st_dev), minor(st.st_dev), (unsigned long long)st.st_ino)); - errno = EBUSY; - goto fail; - } - - if (!(tdb->name = (char *)strdup(name))) { - errno = ENOMEM; - goto fail; - } - - tdb->map_size = st.st_size; - tdb->device = st.st_dev; - tdb->inode = st.st_ino; - tdb->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0])); - if (!tdb->locked) { - TDB_LOG((tdb, 2, "tdb_open_ex: " - "failed to allocate lock structure for %s\n", - name)); - errno = ENOMEM; - goto fail; - } - tdb_mmap(tdb); - if (locked) { - if (!tdb->read_only) - if (tdb_clear_spinlocks(tdb) != 0) { - TDB_LOG((tdb, 0, "tdb_open_ex: " - "failed to clear spinlock\n")); - goto fail; - } - if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) { - TDB_LOG((tdb, 0, "tdb_open_ex: " - "failed to take ACTIVE_LOCK on %s: %s\n", - name, strerror(errno))); - goto fail; - } - } - /* leave this lock in place to indicate it's in use */ - if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) - goto fail; - - internal: - /* Internal (memory-only) databases skip all the code above to - * do with disk files, and resume here by releasing their - * global lock and hooking into the active list. */ - if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1) - goto fail; - tdb->next = tdbs; - tdbs = tdb; - return tdb; - - fail: - { int save_errno = errno; - - if (!tdb) - return NULL; - - if (tdb->map_ptr) { - if (tdb->flags & TDB_INTERNAL) - SAFE_FREE(tdb->map_ptr); - else - tdb_munmap(tdb); - } - SAFE_FREE(tdb->name); - if (tdb->fd != -1) - if (close(tdb->fd) != 0) - TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd on error!\n")); - SAFE_FREE(tdb->locked); - SAFE_FREE(tdb); - errno = save_errno; - return NULL; - } -} - -/** - * Close a database. - * - * @returns -1 for error; 0 for success. - **/ -int tdb_close(TDB_CONTEXT *tdb) -{ - TDB_CONTEXT **i; - int ret = 0; - - if (tdb->map_ptr) { - if (tdb->flags & TDB_INTERNAL) - SAFE_FREE(tdb->map_ptr); - else - tdb_munmap(tdb); - } - SAFE_FREE(tdb->name); - if (tdb->fd != -1) - ret = close(tdb->fd); - SAFE_FREE(tdb->locked); - SAFE_FREE(tdb->lockedkeys); - - /* Remove from contexts list */ - for (i = &tdbs; *i; i = &(*i)->next) { - if (*i == tdb) { - *i = tdb->next; - break; - } - } - - memset(tdb, 0, sizeof(*tdb)); - SAFE_FREE(tdb); - - return ret; -} - -/* lock/unlock entire database */ -int tdb_lockall(TDB_CONTEXT *tdb) -{ - u32 i; - - /* There are no locks on read-only dbs */ - if (tdb->read_only) - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - if (tdb->lockedkeys) - return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - for (i = 0; i < tdb->header.hash_size; i++) - if (tdb_lock(tdb, i, F_WRLCK)) - break; - - /* If error, release locks we have... */ - if (i < tdb->header.hash_size) { - u32 j; - - for ( j = 0; j < i; j++) - tdb_unlock(tdb, j, F_WRLCK); - return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - } - - return 0; -} -void tdb_unlockall(TDB_CONTEXT *tdb) -{ - u32 i; - for (i=0; i < tdb->header.hash_size; i++) - tdb_unlock(tdb, i, F_WRLCK); -} - -int tdb_lockkeys(TDB_CONTEXT *tdb, u32 number, TDB_DATA keys[]) -{ - u32 i, j, hash; - - /* Can't lock more keys if already locked */ - if (tdb->lockedkeys) - return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - if (!(tdb->lockedkeys = malloc(sizeof(u32) * (number+1)))) - return TDB_ERRCODE(TDB_ERR_OOM, -1); - /* First number in array is # keys */ - tdb->lockedkeys[0] = number; - - /* Insertion sort by bucket */ - for (i = 0; i < number; i++) { - hash = tdb_hash(&keys[i]); - for (j = 0; j < i && BUCKET(tdb->lockedkeys[j+1]) < BUCKET(hash); j++); - memmove(&tdb->lockedkeys[j+2], &tdb->lockedkeys[j+1], sizeof(u32) * (i-j)); - tdb->lockedkeys[j+1] = hash; - } - /* Finally, lock in order */ - for (i = 0; i < number; i++) - if (tdb_lock(tdb, i, F_WRLCK)) - break; - - /* If error, release locks we have... */ - if (i < number) { - for ( j = 0; j < i; j++) - tdb_unlock(tdb, j, F_WRLCK); - SAFE_FREE(tdb->lockedkeys); - return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - } - return 0; -} - -/* Unlock the keys previously locked by tdb_lockkeys() */ -void tdb_unlockkeys(TDB_CONTEXT *tdb) -{ - u32 i; - if (!tdb->lockedkeys) - return; - for (i = 0; i < tdb->lockedkeys[0]; i++) - tdb_unlock(tdb, tdb->lockedkeys[i+1], F_WRLCK); - SAFE_FREE(tdb->lockedkeys); -} - -/* lock/unlock one hash chain. This is meant to be used to reduce - contention - it cannot guarantee how many records will be locked */ -int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK); -} - -int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK); -} - -int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK); -} - -int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_RDLCK); -} - - -/* register a loging function */ -void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...)) -{ - tdb->log_fn = fn; -} - - -/* reopen a tdb - this is used after a fork to ensure that we have an independent - seek pointer from our parent and to re-establish locks */ -int tdb_reopen(TDB_CONTEXT *tdb) -{ - struct stat st; - - if (tdb_munmap(tdb) != 0) { - TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno))); - goto fail; - } - if (close(tdb->fd) != 0) - TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n")); - tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0); - if (tdb->fd == -1) { - TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno))); - goto fail; - } - if (fstat(tdb->fd, &st) != 0) { - TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno))); - goto fail; - } - if (st.st_ino != tdb->inode || st.st_dev != tdb->device) { - TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n")); - goto fail; - } - tdb_mmap(tdb); - if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) { - TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n")); - goto fail; - } - - return 0; - -fail: - tdb_close(tdb); - return -1; -} - -/* reopen all tdb's */ -int tdb_reopen_all(void) -{ - TDB_CONTEXT *tdb; - - for (tdb=tdbs; tdb; tdb = tdb->next) { - if (tdb_reopen(tdb) != 0) return -1; - } - - return 0; -} |