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
ldb_wrap_debug(void * context,enum ldb_debug_level level,const char * fmt,va_list ap)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
wrap_casefold(void * context,void * mem_ctx,const char * s)63 char *wrap_casefold(void *context, void *mem_ctx, const char *s)
64 {
65 return strupper_talloc(mem_ctx, s);
66 }
67
68 /* check for memory leaks on the ldb context */
ldb_wrap_destructor(struct ldb_context * ldb)69 static int ldb_wrap_destructor(struct ldb_context *ldb)
70 {
71 size_t *startup_blocks = (size_t *)ldb_get_opaque(ldb, "startup_blocks");
72 if (startup_blocks &&
73 talloc_total_blocks(ldb) > *startup_blocks + 100) {
74 DEBUG(0,("WARNING: probable memory leak in ldb %s - %lu blocks (startup %lu) %lu bytes\n",
75 (char *)ldb_get_opaque(ldb, "wrap_url"),
76 (unsigned long)talloc_total_blocks(ldb),
77 (unsigned long)*startup_blocks,
78 (unsigned long)talloc_total_size(ldb)));
79 #if 0
80 talloc_report_full(ldb, stdout);
81 #endif
82 }
83 return 0;
84 }
85
86 /*
87 wrapped connection to a ldb database
88 to close just talloc_free() the returned ldb_context
89
90 TODO: We need an error_string parameter
91 */
ldb_wrap_connect(TALLOC_CTX * mem_ctx,const char * url,struct auth_session_info * session_info,struct cli_credentials * credentials,unsigned int flags,const char * options[])92 struct ldb_context *ldb_wrap_connect(TALLOC_CTX *mem_ctx,
93 const char *url,
94 struct auth_session_info *session_info,
95 struct cli_credentials *credentials,
96 unsigned int flags,
97 const char *options[])
98 {
99 struct ldb_context *ldb;
100 int ret;
101 struct event_context *ev;
102 char *real_url = NULL;
103 size_t *startup_blocks;
104
105 ldb = ldb_init(mem_ctx);
106 if (ldb == NULL) {
107 return NULL;
108 }
109
110 /* we want to use the existing event context if possible. This
111 relies on the fact that in smbd, everything is a child of
112 the main event_context */
113 ev = event_context_find(ldb);
114
115 if (ldb_set_opaque(ldb, "EventContext", ev)) {
116 talloc_free(ldb);
117 return NULL;
118 }
119
120 if (ldb_set_opaque(ldb, "sessionInfo", session_info)) {
121 talloc_free(ldb);
122 return NULL;
123 }
124
125 if (ldb_set_opaque(ldb, "credentials", credentials)) {
126 talloc_free(ldb);
127 return NULL;
128 }
129
130 ret = ldb_register_samba_handlers(ldb);
131 if (ret == -1) {
132 talloc_free(ldb);
133 return NULL;
134 }
135
136 real_url = private_path(ldb, url);
137 if (real_url == NULL) {
138 talloc_free(ldb);
139 return NULL;
140 }
141
142 /* allow admins to force non-sync ldb for all databases */
143 if (lp_parm_bool(-1, "ldb", "nosync", False)) {
144 flags |= LDB_FLG_NOSYNC;
145 }
146
147 /* we usually want Samba databases to be private. If we later
148 find we need one public, we will need to add a parameter to
149 ldb_wrap_connect() */
150 ldb_set_create_perms(ldb, 0600);
151
152 ret = ldb_connect(ldb, real_url, flags, options);
153 if (ret != LDB_SUCCESS) {
154 talloc_free(ldb);
155 return NULL;
156 }
157
158 ldb_set_debug(ldb, ldb_wrap_debug, NULL);
159
160 ldb_set_utf8_fns(ldb, NULL, wrap_casefold);
161
162 /* setup for leak detection */
163 ldb_set_opaque(ldb, "wrap_url", real_url);
164 startup_blocks = talloc(ldb, size_t);
165 *startup_blocks = talloc_total_blocks(ldb);
166 ldb_set_opaque(ldb, "startup_blocks", startup_blocks);
167
168 talloc_set_destructor(ldb, ldb_wrap_destructor);
169
170 return ldb;
171 }
172
173
174 /*
175 Log tdb messages via DEBUG().
176 */
177 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
178 const char *format, ...) PRINTF_ATTRIBUTE(3,4);
179
tdb_wrap_log(TDB_CONTEXT * tdb,enum tdb_debug_level level,const char * format,...)180 static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level,
181 const char *format, ...)
182 {
183 va_list ap;
184 char *ptr = NULL;
185 int debug_level;
186
187 va_start(ap, format);
188 vasprintf(&ptr, format, ap);
189 va_end(ap);
190
191 switch (level) {
192 case TDB_DEBUG_FATAL:
193 debug_level = 0;
194 break;
195 case TDB_DEBUG_ERROR:
196 debug_level = 1;
197 break;
198 case TDB_DEBUG_WARNING:
199 debug_level = 2;
200 break;
201 case TDB_DEBUG_TRACE:
202 debug_level = 5;
203 break;
204 default:
205 debug_level = 0;
206 }
207
208 if (ptr != NULL) {
209 const char *name = tdb_name(tdb);
210 DEBUG(debug_level, ("tdb(%s): %s", name ? name : "unnamed", ptr));
211 free(ptr);
212 }
213 }
214
215
216 /* destroy the last connection to a tdb */
tdb_wrap_destructor(struct tdb_wrap * w)217 static int tdb_wrap_destructor(struct tdb_wrap *w)
218 {
219 tdb_close(w->tdb);
220 DLIST_REMOVE(tdb_list, w);
221 return 0;
222 }
223
224 /*
225 wrapped connection to a tdb database
226 to close just talloc_free() the tdb_wrap pointer
227 */
tdb_wrap_open(TALLOC_CTX * mem_ctx,const char * name,int hash_size,int tdb_flags,int open_flags,mode_t mode)228 struct tdb_wrap *tdb_wrap_open(TALLOC_CTX *mem_ctx,
229 const char *name, int hash_size, int tdb_flags,
230 int open_flags, mode_t mode)
231 {
232 struct tdb_wrap *w;
233 struct tdb_logging_context log_ctx;
234 log_ctx.log_fn = tdb_wrap_log;
235
236 for (w=tdb_list;w;w=w->next) {
237 if (strcmp(name, w->name) == 0) {
238 return talloc_reference(mem_ctx, w);
239 }
240 }
241
242 w = talloc(mem_ctx, struct tdb_wrap);
243 if (w == NULL) {
244 return NULL;
245 }
246
247 w->name = talloc_strdup(w, name);
248
249 w->tdb = tdb_open_ex(name, hash_size, tdb_flags,
250 open_flags, mode, &log_ctx, NULL);
251 if (w->tdb == NULL) {
252 talloc_free(w);
253 return NULL;
254 }
255
256 talloc_set_destructor(w, tdb_wrap_destructor);
257
258 DLIST_ADD(tdb_list, w);
259
260 return w;
261 }
262