1
0
mirror of https://github.com/samba-team/samba.git synced 2024-12-28 07:21:54 +03:00
samba-mirror/source3/tdb/common/freelistcheck.c
Jeremy Allison cc13e21dbe r19959: Allow tdb to be built standalone in Samba3.
Add code to check for loops in the free list.
Should help us validate tdb's against corruption.
Jeremy.
(This used to be commit f8e7386773)
2007-10-10 12:16:15 -05:00

109 lines
2.7 KiB
C

/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Jeremy Allison 2006
** 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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "tdb_private.h"
/* Check the freelist is good and contains no loops.
Very memory intensive - only do this as a consistency
checker. Heh heh - uses an in memory tdb as the storage
for the "seen" record list. For some reason this strikes
me as extremely clever as I don't have to write another tree
data structure implementation :-).
*/
static int seen_insert(struct tdb_context *mem_tdb, tdb_off_t rec_ptr)
{
TDB_DATA key, data;
memset(&data, '\0', sizeof(data));
key.dptr = (char *)&rec_ptr;
key.dsize = sizeof(rec_ptr);
return tdb_store(mem_tdb, key, data, TDB_INSERT);
}
int tdb_validate_freelist(struct tdb_context *tdb, int *pnum_entries)
{
struct tdb_context *mem_tdb = NULL;
struct list_struct rec;
tdb_off_t rec_ptr, last_ptr;
int ret = -1;
*pnum_entries = 0;
mem_tdb = tdb_open("flval", tdb->header.hash_size,
TDB_INTERNAL, O_RDWR, 0600);
if (!mem_tdb) {
return -1;
}
if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
tdb_close(mem_tdb);
return 0;
}
last_ptr = FREELIST_TOP;
/* Store the FREELIST_TOP record. */
if (seen_insert(mem_tdb, last_ptr) == -1) {
ret = TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
goto fail;
}
/* read in the freelist top */
if (tdb_ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) {
goto fail;
}
while (rec_ptr) {
/* If we can't store this record (we've seen it
before) then the free list has a loop and must
be corrupt. */
if (seen_insert(mem_tdb, rec_ptr)) {
ret = TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
goto fail;
}
if (rec_free_read(tdb, rec_ptr, &rec) == -1) {
goto fail;
}
/* move to the next record */
last_ptr = rec_ptr;
rec_ptr = rec.next;
*pnum_entries += 1;
}
ret = 0;
fail:
tdb_close(mem_tdb);
tdb_unlock(tdb, -1, F_WRLCK);
return ret;
}