Line data Source code
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 : static void ltdb_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
28 1015 : static void ltdb_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
29 : {
30 4 : va_list ap;
31 1015 : const char *name = tdb_name(tdb);
32 1015 : struct ldb_context *ldb = talloc_get_type(tdb_get_logging_private(tdb), struct ldb_context);
33 4 : enum ldb_debug_level ldb_level;
34 4 : char *message;
35 :
36 1015 : if (ldb == NULL)
37 0 : return;
38 :
39 1015 : va_start(ap, fmt);
40 1015 : message = talloc_vasprintf(ldb, fmt, ap);
41 1015 : va_end(ap);
42 :
43 1015 : switch (level) {
44 0 : case TDB_DEBUG_FATAL:
45 0 : ldb_level = LDB_DEBUG_FATAL;
46 0 : break;
47 4 : case TDB_DEBUG_ERROR:
48 4 : ldb_level = LDB_DEBUG_ERROR;
49 4 : break;
50 1007 : case TDB_DEBUG_WARNING:
51 1007 : ldb_level = LDB_DEBUG_WARNING;
52 1007 : break;
53 0 : case TDB_DEBUG_TRACE:
54 0 : ldb_level = LDB_DEBUG_TRACE;
55 0 : break;
56 0 : default:
57 0 : ldb_level = LDB_DEBUG_FATAL;
58 : }
59 :
60 1015 : ldb_debug(ldb, ldb_level, "ltdb: tdb(%s): %s", name, message);
61 1015 : talloc_free(message);
62 : }
63 :
64 : /*
65 : the purpose of this code is to work around the braindead posix locking
66 : rules, to allow us to have a ldb open more than once while allowing
67 : locking to work
68 :
69 : TDB2 handles multiple opens, so we don't have this problem there.
70 : */
71 :
72 : struct ltdb_wrap {
73 : struct ltdb_wrap *next, *prev;
74 : struct tdb_context *tdb;
75 : dev_t device;
76 : ino_t inode;
77 : pid_t pid;
78 : };
79 :
80 : static struct ltdb_wrap *tdb_list;
81 :
82 : /* destroy the last connection to a tdb */
83 226494 : static int ltdb_wrap_destructor(struct ltdb_wrap *w)
84 : {
85 226494 : tdb_close(w->tdb);
86 226494 : DLIST_REMOVE(tdb_list, w);
87 226494 : return 0;
88 : }
89 :
90 : /*
91 : wrapped connection to a tdb database. The caller should _not_ free
92 : this as it is not a talloc structure (as tdb does not use talloc
93 : yet). It will auto-close when the caller frees the mem_ctx that is
94 : passed to this call
95 : */
96 724449 : struct tdb_context *ltdb_wrap_open(TALLOC_CTX *mem_ctx,
97 : const char *path, int hash_size,
98 : int tdb_flags,
99 : int open_flags, mode_t mode,
100 : struct ldb_context *ldb)
101 : {
102 12197 : struct ltdb_wrap *w;
103 12197 : struct tdb_logging_context lctx;
104 12197 : struct stat st;
105 :
106 724449 : if (stat(path, &st) == 0) {
107 2767179 : for (w=tdb_list;w;w=w->next) {
108 2650486 : if (st.st_dev == w->device && st.st_ino == w->inode) {
109 602118 : pid_t pid = getpid();
110 6539 : int ret;
111 602118 : if (!talloc_reference(mem_ctx, w)) {
112 0 : return NULL;
113 : }
114 602118 : if (w->pid != pid) {
115 131983 : ret = tdb_reopen(w->tdb);
116 131983 : if (ret != 0) {
117 : /*
118 : * Avoid use-after-free:
119 : * on fail the TDB
120 : * is closed!
121 : */
122 1 : DLIST_REMOVE(tdb_list,
123 : w);
124 1 : return NULL;
125 : }
126 131982 : w->pid = pid;
127 : }
128 602117 : return w->tdb;
129 : }
130 : }
131 : }
132 :
133 122331 : w = talloc(mem_ctx, struct ltdb_wrap);
134 122331 : if (w == NULL) {
135 0 : return NULL;
136 : }
137 :
138 122331 : lctx.log_fn = ltdb_log_fn;
139 122331 : lctx.log_private = ldb;
140 122331 : w->tdb = tdb_open_ex(path, hash_size, tdb_flags, open_flags, mode,
141 : &lctx, NULL);
142 122331 : if (w->tdb == NULL) {
143 1011 : talloc_free(w);
144 1011 : return NULL;
145 : }
146 :
147 121320 : if (fstat(tdb_fd(w->tdb), &st) != 0) {
148 0 : tdb_close(w->tdb);
149 0 : talloc_free(w);
150 0 : return NULL;
151 : }
152 :
153 121320 : w->device = st.st_dev;
154 121320 : w->inode = st.st_ino;
155 121320 : w->pid = getpid();
156 :
157 121320 : talloc_set_destructor(w, ltdb_wrap_destructor);
158 :
159 121320 : DLIST_ADD(tdb_list, w);
160 :
161 121320 : return w->tdb;
162 : }
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