Copyright updates:
[exim.git] / src / src / lookups / dbmdb.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim Maintainers 2020 */
7 /* See the file NOTICE for conditions of use and distribution. */
8
9 #include "../exim.h"
10 #include "lf_functions.h"
11
12
13 /*************************************************
14 * Open entry point *
15 *************************************************/
16
17 /* See local README for interface description */
18
19 static void *
20 dbmdb_open(const uschar * filename, uschar ** errmsg)
21 {
22 uschar * dirname = string_copy(filename);
23 uschar * s;
24 EXIM_DB *yield = NULL;
25
26 if ((s = Ustrrchr(dirname, '/'))) *s = '\0';
27 EXIM_DBOPEN(filename, dirname, O_RDONLY, 0, &yield);
28 if (!yield)
29 {
30 int save_errno = errno;
31 *errmsg = string_open_failed(errno, "%s as a %s file", filename, EXIM_DBTYPE);
32 errno = save_errno;
33 }
34 return yield;
35 }
36
37
38
39 /*************************************************
40 * Check entry point *
41 *************************************************/
42
43 /* This needs to know more about the underlying files than is good for it!
44 We need to know what the real file names are in order to check the owners and
45 modes. If USE_DB is set, we know it is Berkeley DB, which uses an unmodified
46 file name. If USE_TDB or USE_GDBM is set, we know it is tdb or gdbm, which do
47 the same. Otherwise, for safety, we have to check for x.db or x.dir and x.pag.
48 */
49
50 static BOOL
51 dbmdb_check(void *handle, const uschar *filename, int modemask, uid_t *owners,
52 gid_t *owngroups, uschar **errmsg)
53 {
54 int rc;
55 handle = handle; /* Keep picky compilers happy */
56
57 #if defined(USE_DB) || defined(USE_TDB) || defined(USE_GDBM)
58 rc = lf_check_file(-1, filename, S_IFREG, modemask, owners, owngroups,
59 "dbm", errmsg);
60 #else
61 {
62 uschar filebuffer[256];
63 (void)sprintf(CS filebuffer, "%.250s.db", filename);
64 rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups,
65 "dbm", errmsg);
66 if (rc < 0) /* stat() failed */
67 {
68 (void)sprintf(CS filebuffer, "%.250s.dir", filename);
69 rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups,
70 "dbm", errmsg);
71 if (rc == 0) /* x.dir was OK */
72 {
73 (void)sprintf(CS filebuffer, "%.250s.pag", filename);
74 rc = lf_check_file(-1, filebuffer, S_IFREG, modemask, owners, owngroups,
75 "dbm", errmsg);
76 }
77 }
78 }
79 #endif
80
81 return rc == 0;
82 }
83
84
85
86 /*************************************************
87 * Find entry point *
88 *************************************************/
89
90 /* See local README for interface description. This function adds 1 to
91 the keylength in order to include the terminating zero. */
92
93 static int
94 dbmdb_find(void * handle, const uschar * filename, const uschar * keystring,
95 int length, uschar ** result, uschar ** errmsg, uint * do_cache,
96 const uschar * opts)
97 {
98 EXIM_DB *d = (EXIM_DB *)handle;
99 EXIM_DATUM key, data;
100
101 filename = filename; /* Keep picky compilers happy */
102 errmsg = errmsg;
103 do_cache = do_cache;
104
105 EXIM_DATUM_INIT(key); /* Some DBM libraries require datums to */
106 EXIM_DATUM_INIT(data); /* be cleared before use. */
107 EXIM_DATUM_DATA(key) = CS keystring;
108 EXIM_DATUM_SIZE(key) = length + 1;
109
110 if (EXIM_DBGET(d, key, data))
111 {
112 *result = string_copyn(US EXIM_DATUM_DATA(data), EXIM_DATUM_SIZE(data));
113 EXIM_DATUM_FREE(data); /* Some DBM libraries need a free() call */
114 return OK;
115 }
116 return FAIL;
117 }
118
119
120
121 /*************************************************
122 * Find entry point - no zero on key *
123 *************************************************/
124
125 /* See local README for interface description */
126
127 static int
128 dbmnz_find(void * handle, const uschar * filename, const uschar * keystring,
129 int length, uschar ** result, uschar ** errmsg, uint * do_cache,
130 const uschar * opts)
131 {
132 return dbmdb_find(handle, filename, keystring, length-1, result, errmsg,
133 do_cache, opts);
134 }
135
136
137
138 /*************************************************
139 * Find entry point - zero-joined list key *
140 *************************************************/
141
142 /*
143 * The parameter passed as a key is a list in normal Exim list syntax.
144 * The elements of that list are joined together on NUL, with no trailing
145 * NUL, to form the key.
146 */
147
148 static int
149 dbmjz_find(void * handle, const uschar * filename, const uschar * keystring,
150 int length, uschar ** result, uschar ** errmsg, uint * do_cache,
151 const uschar * opts)
152 {
153 uschar *key_item, *key_buffer, *key_p;
154 const uschar *key_elems = keystring;
155 int buflen, bufleft, key_item_len, sep = 0;
156
157 /* To a first approximation, the size of the lookup key needs to be about,
158 or less than, the length of the delimited list passed in + 1. */
159
160 buflen = length + 3;
161 key_buffer = store_get(buflen, is_tainted(keystring));
162
163 key_buffer[0] = '\0';
164
165 key_p = key_buffer;
166 bufleft = buflen;
167
168 /* In all cases of an empty list item, we can set 1 and advance by 1 and then
169 pick up the trailing NUL from the previous list item, EXCEPT when at the
170 beginning of the output string, in which case we need to supply that NUL
171 ourselves. */
172 while ((key_item = string_nextinlist(&key_elems, &sep, key_p, bufleft)) != NULL)
173 {
174 key_item_len = Ustrlen(key_item) + 1;
175 if (key_item_len == 1)
176 {
177 key_p[0] = '\0';
178 if (key_p == key_buffer)
179 {
180 key_p[1] = '\0';
181 key_item_len += 1;
182 }
183 }
184
185 bufleft -= key_item_len;
186 if (bufleft <= 0)
187 {
188 /* The string_nextinlist() will stop at buffer size, but we should always
189 have at least 1 character extra, so some assumption has failed. */
190 *errmsg = string_copy(US"Ran out of buffer space for joining elements");
191 return DEFER;
192 }
193 key_p += key_item_len;
194 }
195
196 if (key_p == key_buffer)
197 {
198 *errmsg = string_copy(US"empty list key");
199 return FAIL;
200 }
201
202 /* We do not pass in the final NULL; if needed, the list should include an
203 empty element to put one in. Boundary: key length 1, is a NULL */
204 key_item_len = key_p - key_buffer - 1;
205
206 DEBUG(D_lookup) debug_printf_indent("NUL-joined key length: %d\n", key_item_len);
207
208 /* beware that dbmdb_find() adds 1 to length to get back terminating NUL, so
209 because we've calculated the real length, we need to subtract one more here */
210
211 return dbmdb_find(handle, filename, key_buffer, key_item_len - 1,
212 result, errmsg, do_cache, opts);
213 }
214
215
216
217 /*************************************************
218 * Close entry point *
219 *************************************************/
220
221 /* See local README for interface description */
222
223 void
224 static dbmdb_close(void *handle)
225 {
226 EXIM_DBCLOSE((EXIM_DB *)handle);
227 }
228
229
230
231 /*************************************************
232 * Version reporting entry point *
233 *************************************************/
234
235 /* See local README for interface description. */
236
237 #include "../version.h"
238
239 void
240 dbm_version_report(FILE *f)
241 {
242 #ifdef DYNLOOKUP
243 fprintf(f, "Library version: DBM: Exim version %s\n", EXIM_VERSION_STR);
244 #endif
245 }
246
247
248 lookup_info dbm_lookup_info = {
249 .name = US"dbm", /* lookup name */
250 .type = lookup_absfile, /* uses absolute file name */
251 .open = dbmdb_open, /* open function */
252 .check = dbmdb_check, /* check function */
253 .find = dbmdb_find, /* find function */
254 .close = dbmdb_close, /* close function */
255 .tidy = NULL, /* no tidy function */
256 .quote = NULL, /* no quoting function */
257 .version_report = dbm_version_report /* version reporting */
258 };
259
260 lookup_info dbmz_lookup_info = {
261 .name = US"dbmnz", /* lookup name */
262 .type = lookup_absfile, /* uses absolute file name */
263 .open = dbmdb_open, /* sic */ /* open function */
264 .check = dbmdb_check, /* sic */ /* check function */
265 .find = dbmnz_find, /* find function */
266 .close = dbmdb_close, /* sic */ /* close function */
267 .tidy = NULL, /* no tidy function */
268 .quote = NULL, /* no quoting function */
269 .version_report = NULL /* no version reporting (redundant) */
270 };
271
272 lookup_info dbmjz_lookup_info = {
273 .name = US"dbmjz", /* lookup name */
274 .type = lookup_absfile, /* uses absolute file name */
275 .open = dbmdb_open, /* sic */ /* open function */
276 .check = dbmdb_check, /* sic */ /* check function */
277 .find = dbmjz_find, /* find function */
278 .close = dbmdb_close, /* sic */ /* close function */
279 .tidy = NULL, /* no tidy function */
280 .quote = NULL, /* no quoting function */
281 .version_report = NULL /* no version reporting (redundant) */
282 };
283
284 #ifdef DYNLOOKUP
285 #define dbmdb_lookup_module_info _lookup_module_info
286 #endif
287
288 static lookup_info *_lookup_list[] = { &dbm_lookup_info, &dbmz_lookup_info, &dbmjz_lookup_info };
289 lookup_module_info dbmdb_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 3 };
290
291 /* End of lookups/dbmdb.c */