220aba1c39f2317b456204320441818e4f792f46
[exim.git] / src / src / lookups / mysql.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Thanks to Paul Kelly for contributing the original code for these
9 functions. */
10
11
12 #include "../exim.h"
13 #include "lf_functions.h"
14
15 #include <mysql.h> /* The system header */
16
17 /* We define symbols for *_VERSION_ID (numeric), *_VERSION_STR (char*)
18 and *_BASE_STR (char*). It's a bit of guesswork. Especially for mariadb
19 with versions before 10.2, as they do not define there there specific symbols.
20 */
21
22 /* Newer (>= 10.2) MariaDB */
23 #if defined MARIADB_VERSION_ID
24 #define EXIM_MxSQL_VERSION_ID MARIADB_VERSION_ID
25
26 /* MySQL defines MYSQL_VERSION_ID, and MariaDB does so */
27 /* https://dev.mysql.com/doc/refman/5.7/en/c-api-server-client-versions.html */
28 #elif defined LIBMYSQL_VERSION_ID
29 #define EXIM_MxSQL_VERSION_ID LIBMYSQL_VERSION_ID
30 #elif defined MYSQL_VERSION_ID
31 #define EXIM_MxSQL_VERSION_ID MYSQL_VERSION_ID
32
33 #else
34 #define EXIM_MYSQL_VERSION_ID 0
35 #endif
36
37 /* Newer (>= 10.2) MariaDB */
38 #ifdef MARIADB_CLIENT_VERSION_STR
39 #define EXIM_MxSQL_VERSION_STR MARIADB_CLIENT_VERSION_STR
40
41 /* Mysql uses MYSQL_SERVER_VERSION */
42 #elif defined LIBMYSQL_VERSION
43 #define EXIM_MxSQL_VERSION_STR LIBMYSQL_VERSION
44 #elif defined MYSQL_SERVER_VERSION
45 #define EXIM_MxSQL_VERSION_STR MYSQL_SERVER_VERSION
46
47 #else
48 #define EXIM_MxSQL_VERSION_STR "unknown"
49 #endif
50
51 #if defined MARIADB_BASE_VERSION
52 #define EXIM_MxSQL_BASE_STR MARIADB_BASE_VERSION
53
54 #elif defined MARIADB_PACKAGE_VERSION
55 #define EXIM_MxSQL_BASE_STR "mariadb"
56
57 #elif defined MYSQL_BASE_VERSION
58 #define EXIM_MxSQL_BASE_STR MYSQL_BASE_VERSION
59
60 #else
61 #define EXIM_MxSQL_BASE_STR "n.A."
62 #endif
63
64
65 /* Structure and anchor for caching connections. */
66
67 typedef struct mysql_connection {
68 struct mysql_connection *next;
69 uschar *server;
70 MYSQL *handle;
71 } mysql_connection;
72
73 static mysql_connection *mysql_connections = NULL;
74
75
76
77 /*************************************************
78 * Open entry point *
79 *************************************************/
80
81 /* See local README for interface description. */
82
83 static void *
84 mysql_open(const uschar * filename, uschar ** errmsg)
85 {
86 return (void *)(1); /* Just return something non-null */
87 }
88
89
90
91 /*************************************************
92 * Tidy entry point *
93 *************************************************/
94
95 /* See local README for interface description. */
96
97 static void
98 mysql_tidy(void)
99 {
100 mysql_connection *cn;
101 while ((cn = mysql_connections) != NULL)
102 {
103 mysql_connections = cn->next;
104 DEBUG(D_lookup) debug_printf_indent("close MYSQL connection: %s\n", cn->server);
105 mysql_close(cn->handle);
106 }
107 }
108
109
110
111 /*************************************************
112 * Internal search function *
113 *************************************************/
114
115 /* This function is called from the find entry point to do the search for a
116 single server.
117
118 Arguments:
119 query the query string
120 server the server string
121 resultptr where to store the result
122 errmsg where to point an error message
123 defer_break TRUE if no more servers are to be tried after DEFER
124 do_cache set zero if data is changed
125 opts options
126
127 The server string is of the form "host/dbname/user/password". The host can be
128 host:port. This string is in a nextinlist temporary buffer, so can be
129 overwritten.
130
131 Returns: OK, FAIL, or DEFER
132 */
133
134 static int
135 perform_mysql_search(const uschar *query, uschar *server, uschar **resultptr,
136 uschar **errmsg, BOOL *defer_break, uint *do_cache, const uschar * opts)
137 {
138 MYSQL *mysql_handle = NULL; /* Keep compilers happy */
139 MYSQL_RES *mysql_result = NULL;
140 MYSQL_ROW mysql_row_data;
141 MYSQL_FIELD *fields;
142
143 int i;
144 int yield = DEFER;
145 unsigned int num_fields;
146 gstring * result = NULL;
147 mysql_connection *cn;
148 uschar *server_copy = NULL;
149 uschar *sdata[4];
150
151 /* Disaggregate the parameters from the server argument. The order is host,
152 database, user, password. We can write to the string, since it is in a
153 nextinlist temporary buffer. The copy of the string that is used for caching
154 has the password removed. This copy is also used for debugging output. */
155
156 for (int i = 3; i > 0; i--)
157 {
158 uschar *pp = Ustrrchr(server, '/');
159 if (!pp)
160 {
161 *errmsg = string_sprintf("incomplete MySQL server data: %s",
162 (i == 3)? server : server_copy);
163 *defer_break = TRUE;
164 return DEFER;
165 }
166 *pp++ = 0;
167 sdata[i] = pp;
168 if (i == 3) server_copy = string_copy(server); /* sans password */
169 }
170 sdata[0] = server; /* What's left at the start */
171
172 /* See if we have a cached connection to the server */
173
174 for (cn = mysql_connections; cn; cn = cn->next)
175 if (Ustrcmp(cn->server, server_copy) == 0)
176 { mysql_handle = cn->handle; break; }
177
178 /* If no cached connection, we must set one up. Mysql allows for a host name
179 and port to be specified. It also allows the name of a Unix socket to be used.
180 Unfortunately, this contains slashes, but its use is expected to be rare, so
181 the rather cumbersome syntax shouldn't inconvenience too many people. We use
182 this: host:port(socket)[group] where all the parts are optional.
183 The "group" parameter specifies an option group from a MySQL option file. */
184
185 if (!cn)
186 {
187 uschar *p;
188 uschar *socket = NULL;
189 int port = 0;
190 uschar *group = US"exim";
191
192 if ((p = Ustrchr(sdata[0], '[')))
193 {
194 *p++ = 0;
195 group = p;
196 while (*p && *p != ']') p++;
197 *p = 0;
198 }
199
200 if ((p = Ustrchr(sdata[0], '(')))
201 {
202 *p++ = 0;
203 socket = p;
204 while (*p && *p != ')') p++;
205 *p = 0;
206 }
207
208 if ((p = Ustrchr(sdata[0], ':')))
209 {
210 *p++ = 0;
211 port = Uatoi(p);
212 }
213
214 if (Ustrchr(sdata[0], '/'))
215 {
216 *errmsg = string_sprintf("unexpected slash in MySQL server hostname: %s",
217 sdata[0]);
218 *defer_break = TRUE;
219 return DEFER;
220 }
221
222 /* If the database is the empty string, set it NULL - the query must then
223 define it. */
224
225 if (sdata[1][0] == 0) sdata[1] = NULL;
226
227 DEBUG(D_lookup)
228 debug_printf_indent("MYSQL new connection: host=%s port=%d socket=%s "
229 "database=%s user=%s\n", sdata[0], port, socket, sdata[1], sdata[2]);
230
231 /* Get store for a new handle, initialize it, and connect to the server */
232
233 mysql_handle = store_get(sizeof(MYSQL), FALSE);
234 mysql_init(mysql_handle);
235 mysql_options(mysql_handle, MYSQL_READ_DEFAULT_GROUP, CS group);
236 if (mysql_real_connect(mysql_handle,
237 /* host user passwd database */
238 CS sdata[0], CS sdata[2], CS sdata[3], CS sdata[1],
239 port, CS socket, CLIENT_MULTI_RESULTS) == NULL)
240 {
241 *errmsg = string_sprintf("MYSQL connection failed: %s",
242 mysql_error(mysql_handle));
243 *defer_break = FALSE;
244 goto MYSQL_EXIT;
245 }
246
247 /* Add the connection to the cache */
248
249 cn = store_get(sizeof(mysql_connection), FALSE);
250 cn->server = server_copy;
251 cn->handle = mysql_handle;
252 cn->next = mysql_connections;
253 mysql_connections = cn;
254 }
255
256 /* Else use a previously cached connection */
257
258 else
259 {
260 DEBUG(D_lookup)
261 debug_printf_indent("MYSQL using cached connection for %s\n", server_copy);
262 }
263
264 /* Run the query */
265
266 if (mysql_query(mysql_handle, CS query) != 0)
267 {
268 *errmsg = string_sprintf("MYSQL: query failed: %s\n",
269 mysql_error(mysql_handle));
270 *defer_break = FALSE;
271 goto MYSQL_EXIT;
272 }
273
274 /* Pick up the result. If the query was not of the type that returns data,
275 namely INSERT, UPDATE, or DELETE, an error occurs here. However, this situation
276 can be detected by calling mysql_field_count(). If its result is zero, no data
277 was expected (this is all explained clearly in the MySQL manual). In this case,
278 we return the number of rows affected by the command. In this event, we do NOT
279 want to cache the result; also the whole cache for the handle must be cleaned
280 up. Setting do_cache zero requests this. */
281
282 if (!(mysql_result = mysql_use_result(mysql_handle)))
283 {
284 if (mysql_field_count(mysql_handle) == 0)
285 {
286 DEBUG(D_lookup) debug_printf_indent("MYSQL: query was not one that returns data\n");
287 result = string_cat(result,
288 string_sprintf("%d", mysql_affected_rows(mysql_handle)));
289 *do_cache = 0;
290 goto MYSQL_EXIT;
291 }
292 *errmsg = string_sprintf("MYSQL: lookup result failed: %s\n",
293 mysql_error(mysql_handle));
294 *defer_break = FALSE;
295 goto MYSQL_EXIT;
296 }
297
298 /* Find the number of fields returned. If this is one, we don't add field
299 names to the data. Otherwise we do. */
300
301 num_fields = mysql_num_fields(mysql_result);
302
303 /* Get the fields and construct the result string. If there is more than one
304 row, we insert '\n' between them. */
305
306 fields = mysql_fetch_fields(mysql_result);
307
308 while ((mysql_row_data = mysql_fetch_row(mysql_result)))
309 {
310 unsigned long *lengths = mysql_fetch_lengths(mysql_result);
311
312 if (result)
313 result = string_catn(result, US"\n", 1);
314
315 if (num_fields != 1)
316 for (int i = 0; i < num_fields; i++)
317 result = lf_quote(US fields[i].name, US mysql_row_data[i], lengths[i],
318 result);
319
320 else if (mysql_row_data[0] != NULL) /* NULL value yields nothing */
321 result = string_catn(result, US mysql_row_data[0], lengths[0]);
322 }
323
324 /* more results? -1 = no, >0 = error, 0 = yes (keep looping)
325 This is needed because of the CLIENT_MULTI_RESULTS on mysql_real_connect(),
326 we don't expect any more results. */
327
328 while((i = mysql_next_result(mysql_handle)) >= 0)
329 if(i != 0)
330 {
331 *errmsg = string_sprintf(
332 "MYSQL: lookup result error when checking for more results: %s\n",
333 mysql_error(mysql_handle));
334 goto MYSQL_EXIT;
335 }
336 else /* just ignore more results */
337 DEBUG(D_lookup) debug_printf_indent("MYSQL: got unexpected more results\n");
338
339 /* If result is NULL then no data has been found and so we return FAIL.
340 Otherwise, we must terminate the string which has been built; string_cat()
341 always leaves enough room for a terminating zero. */
342
343 if (!result)
344 {
345 yield = FAIL;
346 *errmsg = US"MYSQL: no data found";
347 }
348
349 /* Get here by goto from various error checks and from the case where no data
350 was read (e.g. an update query). */
351
352 MYSQL_EXIT:
353
354 /* Free mysal store for any result that was got; don't close the connection, as
355 it is cached. */
356
357 if (mysql_result) mysql_free_result(mysql_result);
358
359 /* Non-NULL result indicates a successful result */
360
361 if (result)
362 {
363 *resultptr = string_from_gstring(result);
364 gstring_release_unused(result);
365 return OK;
366 }
367 else
368 {
369 DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
370 return yield; /* FAIL or DEFER */
371 }
372 }
373
374
375
376
377 /*************************************************
378 * Find entry point *
379 *************************************************/
380
381 /* See local README for interface description. The handle and filename
382 arguments are not used. The code to loop through a list of servers while the
383 query is deferred with a retryable error is now in a separate function that is
384 shared with other SQL lookups. */
385
386 static int
387 mysql_find(void * handle, const uschar * filename, const uschar * query,
388 int length, uschar ** result, uschar ** errmsg, uint * do_cache,
389 const uschar * opts)
390 {
391 return lf_sqlperform(US"MySQL", US"mysql_servers", mysql_servers, query,
392 result, errmsg, do_cache, opts, perform_mysql_search);
393 }
394
395
396
397 /*************************************************
398 * Quote entry point *
399 *************************************************/
400
401 /* The only characters that need to be quoted (with backslash) are newline,
402 tab, carriage return, backspace, backslash itself, and the quote characters.
403 Percent, and underscore and not escaped. They are only special in contexts
404 where they can be wild cards, and this isn't usually the case for data inserted
405 from messages, since that isn't likely to be treated as a pattern of any kind.
406 Sadly, MySQL doesn't seem to behave like other programs. If you use something
407 like "where id="ab\%cd" it does not treat the string as "ab%cd". So you really
408 can't quote "on spec".
409
410 Arguments:
411 s the string to be quoted
412 opt additional option text or NULL if none
413
414 Returns: the processed string or NULL for a bad option
415 */
416
417 static uschar *
418 mysql_quote(uschar *s, uschar *opt)
419 {
420 register int c;
421 int count = 0;
422 uschar *t = s;
423 uschar *quoted;
424
425 if (opt != NULL) return NULL; /* No options recognized */
426
427 while ((c = *t++) != 0)
428 if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL) count++;
429
430 if (count == 0) return s;
431 t = quoted = store_get(Ustrlen(s) + count + 1, is_tainted(s));
432
433 while ((c = *s++) != 0)
434 {
435 if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL)
436 {
437 *t++ = '\\';
438 switch(c)
439 {
440 case '\n': *t++ = 'n';
441 break;
442 case '\t': *t++ = 't';
443 break;
444 case '\r': *t++ = 'r';
445 break;
446 case '\b': *t++ = 'b';
447 break;
448 default: *t++ = c;
449 break;
450 }
451 }
452 else *t++ = c;
453 }
454
455 *t = 0;
456 return quoted;
457 }
458
459
460 /*************************************************
461 * Version reporting entry point *
462 *************************************************/
463
464 /* See local README for interface description. */
465
466 #include "../version.h"
467
468 void
469 mysql_version_report(FILE *f)
470 {
471 fprintf(f, "Library version: MySQL: Compile: %lu %s [%s]\n"
472 " Runtime: %lu %s\n",
473 (long)EXIM_MxSQL_VERSION_ID, EXIM_MxSQL_VERSION_STR, EXIM_MxSQL_BASE_STR,
474 mysql_get_client_version(), mysql_get_client_info());
475 #ifdef DYNLOOKUP
476 fprintf(f, " Exim version %s\n", EXIM_VERSION_STR);
477 #endif
478 }
479
480 /* These are the lookup_info blocks for this driver */
481
482 static lookup_info mysql_lookup_info = {
483 US"mysql", /* lookup name */
484 lookup_querystyle, /* query-style lookup */
485 mysql_open, /* open function */
486 NULL, /* no check function */
487 mysql_find, /* find function */
488 NULL, /* no close function */
489 mysql_tidy, /* tidy function */
490 mysql_quote, /* quoting function */
491 mysql_version_report /* version reporting */
492 };
493
494 #ifdef DYNLOOKUP
495 #define mysql_lookup_module_info _lookup_module_info
496 #endif
497
498 static lookup_info *_lookup_list[] = { &mysql_lookup_info };
499 lookup_module_info mysql_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
500
501 /* End of lookups/mysql.c */