source4/lib/db_wrap.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    database wrap functions
   5
   6    Copyright (C) Andrew Tridgell 2004
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 /*
  24   the stupidity of the unix fcntl locking design forces us to never
  25   allow a database file to be opened twice in the same process. These
  26   wrappers provide convenient access to a tdb or ldb, taking advantage
  27   of talloc destructors to ensure that only a single open is done
  28 */
  29
  30 #include "includes.h"
  31 #include "lib/util/dlinklist.h"
  32 #include "lib/events/events.h"
  33 #include "lib/tdb/include/tdb.h"
  34 #include "lib/ldb/include/ldb.h"
  35 #include "lib/ldb/include/ldb_errors.h"
  36 #include "lib/ldb/samba/ldif_handlers.h"
  37 #include "db_wrap.h"
  38
  39 static struct tdb_wrap *tdb_list;
  40
  41 /*
  42   this is used to catch debug messages from ldb
  43 */
  44 static void ldb_wrap_debug(void *context, enum ldb_debug_level level,
  45                            const char *fmt, va_list ap)  PRINTF_ATTRIBUTE(3,0);
  46
  47 static void ldb_wrap_debug(void *context, enum ldb_debug_level level,
  48                            const char *fmt, va_list ap)
  49 {
  50         char *s = NULL;
  51         if (DEBUGLEVEL < 4 && level > LDB_DEBUG_WARNING) {
  52                 return;
  53         }
  54         if (DEBUGLEVEL < 2 && level > LDB_DEBUG_ERROR) {
  55                 return;
  56         }
  57         vasprintf(&s, fmt, ap);
  58         if (!s) return;
  59         DEBUG(level, ("ldb: %s\n", s));
  60         free(s);
  61 }
  62
  63 char *wrap_casefold(void *context, void *mem_ctx, const char *s)
  64 {
  65         return strupper_talloc(mem_ctx, s);
  66 }
  67
  68 /*
  69   wrapped connection to a ldb database
  70   to close just talloc_free() the returned ldb_context
  71
  72   TODO:  We need an error_string parameter
  73  */
  74 struct ldb_context *ldb_wrap_connect(TALLOC_CTX *mem_ctx,
  75                                      const char *url,
  76                                      struct auth_session_info *session_info,
  77                                      struct cli_credentials *credentials,
  78                                      unsigned int flags,
  79                                      const char *options[])
  80 {
  81         struct ldb_context *ldb;
  82         int ret;
  83         struct event_context *ev;
  84         char *real_url = NULL;
  85
  86         ldb = ldb_init(mem_ctx);
  87         if (ldb == NULL) {
  88                 return NULL;
  89         }
  90
  91         /* we want to use the existing event context if possible. This
  92            relies on the fact that in smbd, everything is a child of
  93            the main event_context */
  94         ev = event_context_find(ldb);
  95
  96         if (ldb_set_opaque(ldb, "EventContext", ev)) {
  97                 talloc_free(ldb);
  98                 return NULL;
  99         }
 100
 101         if (ldb_set_opaque(ldb, "sessionInfo", session_info)) {
 102                 talloc_free(ldb);
 103                 return NULL;
 104         }
 105
 106         if (ldb_set_opaque(ldb, "credentials", credentials)) {
 107                 talloc_free(ldb);
 108                 return NULL;
 109         }
 110
 111         ret = ldb_register_samba_handlers(ldb);
 112         if (ret == -1) {
 113                 talloc_free(ldb);
 114                 return NULL;
 115         }
 116
 117         real_url = private_path(ldb, url);
 118         if (real_url == NULL) {
 119                 talloc_free(ldb);
 120                 return NULL;
 121         }
 122
 123         /* allow admins to force non-sync ldb for all databases */
 124         if (lp_parm_bool(-1, "ldb", "nosync", False)) {
 125                 flags |= LDB_FLG_NOSYNC;
 126         }
 127
 128         /* we usually want Samba databases to be private. If we later
 129            find we need one public, we will need to add a parameter to
 130            ldb_wrap_connect() */
 131         ldb_set_create_perms(ldb, 0600);
 132
 133         ret = ldb_connect(ldb, real_url, flags, options);
 134         if (ret != LDB_SUCCESS) {
 135                 talloc_free(ldb);
 136                 return NULL;
 137         }
 138
 139         talloc_free(real_url);
 140
 141         ldb_set_debug(ldb, ldb_wrap_debug, NULL);
 142
 143         ldb_set_utf8_fns(ldb, NULL, wrap_casefold);
 144
 145         return ldb;
 146 }
 147
 148
 149 /*
 150  Log tdb messages via DEBUG().
 151 */
 152 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
 153                          const char *format, ...) PRINTF_ATTRIBUTE(3,4);
 154
 155 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
 156                          const char *format, ...)
 157 {
 158         va_list ap;
 159         char *ptr = NULL;
 160         int debug_level;
 161
 162         va_start(ap, format);
 163         vasprintf(&ptr, format, ap);
 164         va_end(ap);
 165
 166         switch (level) {
 167         case TDB_DEBUG_FATAL:
 168                 debug_level = 0;
 169                 break;
 170         case TDB_DEBUG_ERROR:
 171                 debug_level = 1;
 172                 break;
 173         case TDB_DEBUG_WARNING:
 174                 debug_level = 2;
 175                 break;
 176         case TDB_DEBUG_TRACE:
 177                 debug_level = 5;
 178                 break;
 179         default:
 180                 debug_level = 0;
 181         }
 182
 183         if (ptr != NULL) {
 184                 const char *name = tdb_name(tdb);
 185                 DEBUG(debug_level, ("tdb(%s): %s", name ? name : "unnamed", ptr));
 186                 free(ptr);
 187         }
 188 }
 189
 190
 191 /* destroy the last connection to a tdb */
 192 static int tdb_wrap_destructor(struct tdb_wrap *w)
 193 {
 194         tdb_close(w->tdb);
 195         DLIST_REMOVE(tdb_list, w);
 196         return 0;
 197 }
 198
 199 /*
 200   wrapped connection to a tdb database
 201   to close just talloc_free() the tdb_wrap pointer
 202  */
 203 struct tdb_wrap *tdb_wrap_open(TALLOC_CTX *mem_ctx,
 204                                const char *name, int hash_size, int tdb_flags,
 205                                int open_flags, mode_t mode)
 206 {
 207         struct tdb_wrap *w;
 208         struct tdb_logging_context log_ctx;
 209         log_ctx.log_fn = tdb_wrap_log;
 210
 211         for (w=tdb_list;w;w=w->next) {
 212                 if (strcmp(name, w->name) == 0) {
 213                         return talloc_reference(mem_ctx, w);
 214                 }
 215         }
 216
 217         w = talloc(mem_ctx, struct tdb_wrap);
 218         if (w == NULL) {
 219                 return NULL;
 220         }
 221
 222         w->name = talloc_strdup(w, name);
 223
 224         w->tdb = tdb_open_ex(name, hash_size, tdb_flags,
 225                              open_flags, mode, &log_ctx, NULL);
 226         if (w->tdb == NULL) {
 227                 talloc_free(w);
 228                 return NULL;
 229         }
 230
 231         talloc_set_destructor(w, tdb_wrap_destructor);
 232
 233         DLIST_ADD(tdb_list, w);
 234
 235         return w;
 236 }