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