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 "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         ret = ldb_connect(ldb, real_url, flags, options);
 129         if (ret != LDB_SUCCESS) {
 130                 talloc_free(ldb);
 131                 return NULL;
 132         }
 133
 134         talloc_free(real_url);
 135
 136         ldb_set_debug(ldb, ldb_wrap_debug, NULL);
 137
 138         ldb_set_utf8_fns(ldb, NULL, wrap_casefold);
 139
 140         return ldb;
 141 }
 142
 143
 144 /*
 145  Log tdb messages via DEBUG().
 146 */
 147 static void tdb_wrap_log(TDB_CONTEXT *tdb, int level,
 148                          const char *format, ...) PRINTF_ATTRIBUTE(3,4);
 149
 150 static void tdb_wrap_log(TDB_CONTEXT *tdb, int level,
 151                          const char *format, ...)
 152 {
 153         va_list ap;
 154         char *ptr = NULL;
 155
 156         va_start(ap, format);
 157         vasprintf(&ptr, format, ap);
 158         va_end(ap);
 159
 160         if (ptr != NULL) {
 161                 const char *name = tdb_name(tdb);
 162                 DEBUG(level, ("tdb(%s): %s", name ? name : "unnamed", ptr));
 163                 free(ptr);
 164         }
 165 }
 166
 167
 168 /* destroy the last connection to a tdb */
 169 static int tdb_wrap_destructor(struct tdb_wrap *w)
 170 {
 171         tdb_close(w->tdb);
 172         DLIST_REMOVE(tdb_list, w);
 173         return 0;
 174 }
 175
 176 /*
 177   wrapped connection to a tdb database
 178   to close just talloc_free() the tdb_wrap pointer
 179  */
 180 struct tdb_wrap *tdb_wrap_open(TALLOC_CTX *mem_ctx,
 181                                const char *name, int hash_size, int tdb_flags,
 182                                int open_flags, mode_t mode)
 183 {
 184         struct tdb_wrap *w;
 185
 186         for (w=tdb_list;w;w=w->next) {
 187                 if (strcmp(name, w->name) == 0) {
 188                         return talloc_reference(mem_ctx, w);
 189                 }
 190         }
 191
 192         w = talloc(mem_ctx, struct tdb_wrap);
 193         if (w == NULL) {
 194                 return NULL;
 195         }
 196
 197         w->name = talloc_strdup(w, name);
 198
 199         w->tdb = tdb_open_ex(name, hash_size, tdb_flags,
 200                              open_flags, mode, tdb_wrap_log, NULL);
 201         if (w->tdb == NULL) {
 202                 talloc_free(w);
 203                 return NULL;
 204         }
 205
 206         talloc_set_destructor(w, tdb_wrap_destructor);
 207
 208         DLIST_ADD(tdb_list, w);
 209
 210         return w;
 211 }