lib/ldb/ldb_tdb/ldb_tdb_wrap.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Andrew Tridgell  2005
   5
   6      ** NOTE! The following LGPL license applies to the ldb
   7      ** library. This does NOT imply that all of Samba is released
   8      ** under the LGPL
   9
  10    This library is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU Lesser General Public
  12    License as published by the Free Software Foundation; either
  13    version 3 of the License, or (at your option) any later version.
  14
  15    This library is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License for more details.
  19
  20    You should have received a copy of the GNU Lesser General Public
  21    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "ldb_tdb.h"
  25 #include "dlinklist.h"
  26
  27 /* FIXME: TDB2 does this internally, so no need to wrap multiple opens! */
  28 #if BUILD_TDB2
  29 static void ltdb_log_fn(struct tdb_context *tdb,
  30                         enum tdb_log_level level,
  31                         enum TDB_ERROR ecode,
  32                         const char *message,
  33                         struct ldb_context *ldb)
  34 {
  35         enum ldb_debug_level ldb_level;
  36         const char *name = tdb_name(tdb);
  37
  38         switch (level) {
  39         case TDB_LOG_WARNING:
  40                 ldb_level = LDB_DEBUG_WARNING;
  41         case TDB_LOG_USE_ERROR:
  42         case TDB_LOG_ERROR:
  43                 ldb_level = LDB_DEBUG_FATAL;
  44                 break;
  45         default:
  46                 ldb_level = LDB_DEBUG_FATAL;
  47         }
  48
  49         ldb_debug(ldb, ldb_level, "ltdb: tdb(%s): %s: %s", name,
  50                   tdb_errorstr(ecode), message);
  51 }
  52 #else /* !TDB2 */
  53 static void ltdb_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
  54 static void ltdb_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
  55 {
  56         va_list ap;
  57         const char *name = tdb_name(tdb);
  58         struct ldb_context *ldb = talloc_get_type(tdb_get_logging_private(tdb), struct ldb_context);
  59         enum ldb_debug_level ldb_level;
  60         char *message;
  61
  62         if (ldb == NULL)
  63                 return;
  64
  65         va_start(ap, fmt);
  66         message = talloc_vasprintf(ldb, fmt, ap);
  67         va_end(ap);
  68
  69         switch (level) {
  70         case TDB_DEBUG_FATAL:
  71                 ldb_level = LDB_DEBUG_FATAL;
  72                 break;
  73         case TDB_DEBUG_ERROR:
  74                 ldb_level = LDB_DEBUG_ERROR;
  75                 break;
  76         case TDB_DEBUG_WARNING:
  77                 ldb_level = LDB_DEBUG_WARNING;
  78                 break;
  79         case TDB_DEBUG_TRACE:
  80                 ldb_level = LDB_DEBUG_TRACE;
  81                 break;
  82         default:
  83                 ldb_level = LDB_DEBUG_FATAL;
  84         }
  85
  86         ldb_debug(ldb, ldb_level, "ltdb: tdb(%s): %s", name, message);
  87         talloc_free(message);
  88 }
  89 #endif
  90
  91 /*
  92   the purpose of this code is to work around the braindead posix locking
  93   rules, to allow us to have a ldb open more than once while allowing
  94   locking to work
  95
  96   TDB2 handles multiple opens, so we don't have this problem there.
  97 */
  98
  99 struct ltdb_wrap {
 100         struct ltdb_wrap *next, *prev;
 101         struct tdb_context *tdb;
 102         dev_t device;
 103         ino_t inode;
 104 };
 105
 106 static struct ltdb_wrap *tdb_list;
 107
 108 /* destroy the last connection to a tdb */
 109 static int ltdb_wrap_destructor(struct ltdb_wrap *w)
 110 {
 111         tdb_close(w->tdb);
 112         DLIST_REMOVE(tdb_list, w);
 113         return 0;
 114 }
 115
 116 /*
 117   wrapped connection to a tdb database. The caller should _not_ free
 118   this as it is not a talloc structure (as tdb does not use talloc
 119   yet). It will auto-close when the caller frees the mem_ctx that is
 120   passed to this call
 121  */
 122 struct tdb_context *ltdb_wrap_open(TALLOC_CTX *mem_ctx,
 123                                    const char *path, int hash_size,
 124                                    int tdb_flags,
 125                                    int open_flags, mode_t mode,
 126                                    struct ldb_context *ldb)
 127 {
 128         struct ltdb_wrap *w;
 129         struct stat st;
 130
 131         if (stat(path, &st) == 0) {
 132                 for (w=tdb_list;w;w=w->next) {
 133                         if (st.st_dev == w->device && st.st_ino == w->inode) {
 134                                 if (!talloc_reference(mem_ctx, w)) {
 135                                         return NULL;
 136                                 }
 137                                 return w->tdb;
 138                         }
 139                 }
 140         }
 141
 142         w = talloc(mem_ctx, struct ltdb_wrap);
 143         if (w == NULL) {
 144                 return NULL;
 145         }
 146
 147         w->tdb = tdb_open_compat(path, hash_size, tdb_flags, open_flags, mode, ltdb_log_fn, ldb);
 148         if (w->tdb == NULL) {
 149                 talloc_free(w);
 150                 return NULL;
 151         }
 152
 153         if (fstat(tdb_fd(w->tdb), &st) != 0) {
 154                 tdb_close(w->tdb);
 155                 talloc_free(w);
 156                 return NULL;
 157         }
 158
 159         w->device = st.st_dev;
 160         w->inode  = st.st_ino;
 161
 162         talloc_set_destructor(w, ltdb_wrap_destructor);
 163
 164         DLIST_ADD(tdb_list, w);
 165
 166         return w->tdb;
 167 }