Tidying: coverity issues
[exim.git] / src / src / lookups / pgsql.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2015 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Thanks to Petr Cech for contributing the original code for these
9 functions. Thanks to Joachim Wieland for the initial patch for the Unix domain
10 socket extension. */
11
12 #include "../exim.h"
13 #include "lf_functions.h"
14
15 #include <libpq-fe.h> /* The system header */
16
17 /* Structure and anchor for caching connections. */
18
19 typedef struct pgsql_connection {
20 struct pgsql_connection *next;
21 uschar *server;
22 PGconn *handle;
23 } pgsql_connection;
24
25 static pgsql_connection *pgsql_connections = NULL;
26
27
28
29 /*************************************************
30 * Open entry point *
31 *************************************************/
32
33 /* See local README for interface description. */
34
35 static void *
36 pgsql_open(uschar *filename, uschar **errmsg)
37 {
38 return (void *)(1); /* Just return something non-null */
39 }
40
41
42
43 /*************************************************
44 * Tidy entry point *
45 *************************************************/
46
47 /* See local README for interface description. */
48
49 static void
50 pgsql_tidy(void)
51 {
52 pgsql_connection *cn;
53 while ((cn = pgsql_connections) != NULL)
54 {
55 pgsql_connections = cn->next;
56 DEBUG(D_lookup) debug_printf("close PGSQL connection: %s\n", cn->server);
57 PQfinish(cn->handle);
58 }
59 }
60
61
62 /*************************************************
63 * Notice processor function for pgsql *
64 *************************************************/
65
66 /* This function is passed to pgsql below, and called for any PostgreSQL
67 "notices". By default they are written to stderr, which is undesirable.
68
69 Arguments:
70 arg an opaque user cookie (not used)
71 message the notice
72
73 Returns: nothing
74 */
75
76 static void
77 notice_processor(void *arg, const char *message)
78 {
79 arg = arg; /* Keep compiler happy */
80 DEBUG(D_lookup) debug_printf("PGSQL: %s\n", message);
81 }
82
83
84
85 /*************************************************
86 * Internal search function *
87 *************************************************/
88
89 /* This function is called from the find entry point to do the search for a
90 single server. The server string is of the form "server/dbname/user/password".
91
92 PostgreSQL supports connections through Unix domain sockets. This is usually
93 faster and costs less cpu time than a TCP/IP connection. However it can only be
94 used if the mail server runs on the same machine as the database server. A
95 configuration line for PostgreSQL via Unix domain sockets looks like this:
96
97 hide pgsql_servers = (/tmp/.s.PGSQL.5432)/db/user/password[:<nextserver>]
98
99 We enclose the path name in parentheses so that its slashes aren't visually
100 confused with the delimeters for the other pgsql_server settings.
101
102 For TCP/IP connections, the server is a host name and optional port (with a
103 colon separator).
104
105 NOTE:
106 1) All three '/' must be present.
107 2) If host is omitted the local unix socket is used.
108
109 Arguments:
110 query the query string
111 server the server string; this is in dynamic memory and can be updated
112 resultptr where to store the result
113 errmsg where to point an error message
114 defer_break set TRUE if no more servers are to be tried after DEFER
115 do_cache set FALSE if data is changed
116
117 Returns: OK, FAIL, or DEFER
118 */
119
120 static int
121 perform_pgsql_search(const uschar *query, uschar *server, uschar **resultptr,
122 uschar **errmsg, BOOL *defer_break, uint *do_cache)
123 {
124 PGconn *pg_conn = NULL;
125 PGresult *pg_result = NULL;
126
127 int i;
128 uschar *result = NULL;
129 int ssize = 0;
130 int offset = 0;
131 int yield = DEFER;
132 unsigned int num_fields, num_tuples;
133 pgsql_connection *cn;
134 uschar *server_copy = NULL;
135 uschar *sdata[3];
136
137 /* Disaggregate the parameters from the server argument. The order is host or
138 path, database, user, password. We can write to the string, since it is in a
139 nextinlist temporary buffer. The copy of the string that is used for caching
140 has the password removed. This copy is also used for debugging output. */
141
142 for (i = 2; i >= 0; i--)
143 {
144 uschar *pp = Ustrrchr(server, '/');
145 if (pp == NULL)
146 {
147 *errmsg = string_sprintf("incomplete pgSQL server data: %s",
148 (i == 2)? server : server_copy);
149 *defer_break = TRUE;
150 return DEFER;
151 }
152 *pp++ = 0;
153 sdata[i] = pp;
154 if (i == 2) server_copy = string_copy(server); /* sans password */
155 }
156
157 /* The total server string has now been truncated so that what is left at the
158 start is the identification of the server (host or path). See if we have a
159 cached connection to the server. */
160
161 for (cn = pgsql_connections; cn != NULL; cn = cn->next)
162 {
163 if (Ustrcmp(cn->server, server_copy) == 0)
164 {
165 pg_conn = cn->handle;
166 break;
167 }
168 }
169
170 /* If there is no cached connection, we must set one up. */
171
172 if (cn == NULL)
173 {
174 uschar *port = US"";
175
176 /* For a Unix domain socket connection, the path is in parentheses */
177
178 if (*server == '(')
179 {
180 uschar *last_slash, *last_dot, *p;
181
182 p = ++server;
183 while (*p != 0 && *p != ')') p++;
184 *p = 0;
185
186 last_slash = Ustrrchr(server, '/');
187 last_dot = Ustrrchr(server, '.');
188
189 DEBUG(D_lookup) debug_printf("PGSQL new connection: socket=%s "
190 "database=%s user=%s\n", server, sdata[0], sdata[1]);
191
192 /* A valid socket name looks like this: /var/run/postgresql/.s.PGSQL.5432
193 We have to call PQsetdbLogin with '/var/run/postgresql' as the hostname
194 argument and put '5432' into the port variable. */
195
196 if (last_slash == NULL || last_dot == NULL)
197 {
198 *errmsg = string_sprintf("PGSQL invalid filename for socket: %s",
199 server);
200 *defer_break = TRUE;
201 return DEFER;
202 }
203
204 /* Terminate the path name and set up the port: we'll have something like
205 server = "/var/run/postgresql" and port = "5432". */
206
207 *last_slash = 0;
208 port = last_dot + 1;
209 }
210
211 /* Host connection; sort out the port */
212
213 else
214 {
215 uschar *p;
216 if ((p = Ustrchr(server, ':')) != NULL)
217 {
218 *p++ = 0;
219 port = p;
220 }
221
222 if (Ustrchr(server, '/') != NULL)
223 {
224 *errmsg = string_sprintf("unexpected slash in pgSQL server hostname: %s",
225 server);
226 *defer_break = TRUE;
227 return DEFER;
228 }
229
230 DEBUG(D_lookup) debug_printf("PGSQL new connection: host=%s port=%s "
231 "database=%s user=%s\n", server, port, sdata[0], sdata[1]);
232 }
233
234 /* If the database is the empty string, set it NULL - the query must then
235 define it. */
236
237 if (sdata[0][0] == 0) sdata[0] = NULL;
238
239 /* Get store for a new handle, initialize it, and connect to the server */
240
241 pg_conn=PQsetdbLogin(
242 /* host port options tty database user passwd */
243 CS server, CS port, NULL, NULL, CS sdata[0], CS sdata[1], CS sdata[2]);
244
245 if(PQstatus(pg_conn) == CONNECTION_BAD)
246 {
247 store_reset(server_copy);
248 *errmsg = string_sprintf("PGSQL connection failed: %s",
249 PQerrorMessage(pg_conn));
250 PQfinish(pg_conn);
251 goto PGSQL_EXIT;
252 }
253
254 /* Set the client encoding to SQL_ASCII, which means that the server will
255 not try to interpret the query as being in any fancy encoding such as UTF-8
256 or other multibyte code that might cause problems with escaping. */
257
258 PQsetClientEncoding(pg_conn, "SQL_ASCII");
259
260 /* Set the notice processor to prevent notices from being written to stderr
261 (which is what the default does). Our function (above) just produces debug
262 output. */
263
264 PQsetNoticeProcessor(pg_conn, notice_processor, NULL);
265
266 /* Add the connection to the cache */
267
268 cn = store_get(sizeof(pgsql_connection));
269 cn->server = server_copy;
270 cn->handle = pg_conn;
271 cn->next = pgsql_connections;
272 pgsql_connections = cn;
273 }
274
275 /* Else use a previously cached connection */
276
277 else
278 {
279 DEBUG(D_lookup) debug_printf("PGSQL using cached connection for %s\n",
280 server_copy);
281 }
282
283 /* Run the query */
284
285 pg_result = PQexec(pg_conn, CS query);
286 switch(PQresultStatus(pg_result))
287 {
288 case PGRES_EMPTY_QUERY:
289 case PGRES_COMMAND_OK:
290 /* The command was successful but did not return any data since it was
291 * not SELECT but either an INSERT, UPDATE or DELETE statement. Tell the
292 * high level code to not cache this query, and clean the current cache for
293 * this handle by setting *do_cache zero. */
294 result = string_copy(US PQcmdTuples(pg_result));
295 offset = Ustrlen(result);
296 *do_cache = 0;
297 DEBUG(D_lookup) debug_printf("PGSQL: command does not return any data "
298 "but was successful. Rows affected: %s\n", result);
299
300 case PGRES_TUPLES_OK:
301 break;
302
303 default:
304 /* This was the original code:
305 *errmsg = string_sprintf("PGSQL: query failed: %s\n",
306 PQresultErrorMessage(pg_result));
307 This was suggested by a user:
308 */
309
310 *errmsg = string_sprintf("PGSQL: query failed: %s (%s) (%s)\n",
311 PQresultErrorMessage(pg_result),
312 PQresStatus(PQresultStatus(pg_result)), query);
313 goto PGSQL_EXIT;
314 }
315
316 /* Result is in pg_result. Find the number of fields returned. If this is one,
317 we don't add field names to the data. Otherwise we do. If the query did not
318 return anything we skip the for loop; this also applies to the case
319 PGRES_COMMAND_OK. */
320
321 num_fields = PQnfields(pg_result);
322 num_tuples = PQntuples(pg_result);
323
324 /* Get the fields and construct the result string. If there is more than one
325 row, we insert '\n' between them. */
326
327 for (i = 0; i < num_tuples; i++)
328 {
329 if (result != NULL)
330 result = string_catn(result, &ssize, &offset, US"\n", 1);
331
332 if (num_fields == 1)
333 {
334 result = string_catn(result, &ssize, &offset,
335 US PQgetvalue(pg_result, i, 0), PQgetlength(pg_result, i, 0));
336 }
337
338 else
339 {
340 int j;
341 for (j = 0; j < num_fields; j++)
342 {
343 uschar *tmp = US PQgetvalue(pg_result, i, j);
344 result = lf_quote(US PQfname(pg_result, j), tmp, Ustrlen(tmp), result,
345 &ssize, &offset);
346 }
347 }
348 }
349
350 /* If result is NULL then no data has been found and so we return FAIL.
351 Otherwise, we must terminate the string which has been built; string_cat()
352 always leaves enough room for a terminating zero. */
353
354 if (result == NULL)
355 {
356 yield = FAIL;
357 *errmsg = US"PGSQL: no data found";
358 }
359 else
360 {
361 result[offset] = 0;
362 store_reset(result + offset + 1);
363 }
364
365 /* Get here by goto from various error checks. */
366
367 PGSQL_EXIT:
368
369 /* Free store for any result that was got; don't close the connection, as
370 it is cached. */
371
372 if (pg_result != NULL) PQclear(pg_result);
373
374 /* Non-NULL result indicates a sucessful result */
375
376 if (result != NULL)
377 {
378 *resultptr = result;
379 return OK;
380 }
381 else
382 {
383 DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
384 return yield; /* FAIL or DEFER */
385 }
386 }
387
388
389
390
391 /*************************************************
392 * Find entry point *
393 *************************************************/
394
395 /* See local README for interface description. The handle and filename
396 arguments are not used. The code to loop through a list of servers while the
397 query is deferred with a retryable error is now in a separate function that is
398 shared with other SQL lookups. */
399
400 static int
401 pgsql_find(void *handle, uschar *filename, const uschar *query, int length,
402 uschar **result, uschar **errmsg, uint *do_cache)
403 {
404 return lf_sqlperform(US"PostgreSQL", US"pgsql_servers", pgsql_servers, query,
405 result, errmsg, do_cache, perform_pgsql_search);
406 }
407
408
409
410 /*************************************************
411 * Quote entry point *
412 *************************************************/
413
414 /* The characters that always need to be quoted (with backslash) are newline,
415 tab, carriage return, backspace, backslash itself, and the quote characters.
416
417 The original code quoted single quotes as \' which is documented as valid in
418 the O'Reilly book "Practical PostgreSQL" (first edition) as an alternative to
419 the SQL standard '' way of representing a single quote as data. However, in
420 June 2006 there was some security issue with using \' and so this has been
421 changed.
422
423 [Note: There is a function called PQescapeStringConn() that quotes strings.
424 This cannot be used because it needs a PGconn argument (the connection handle).
425 Why, I don't know. Seems odd for just string escaping...]
426
427 Arguments:
428 s the string to be quoted
429 opt additional option text or NULL if none
430
431 Returns: the processed string or NULL for a bad option
432 */
433
434 static uschar *
435 pgsql_quote(uschar *s, uschar *opt)
436 {
437 register int c;
438 int count = 0;
439 uschar *t = s;
440 uschar *quoted;
441
442 if (opt != NULL) return NULL; /* No options recognized */
443
444 while ((c = *t++) != 0)
445 if (Ustrchr("\n\t\r\b\'\"\\", c) != NULL) count++;
446
447 if (count == 0) return s;
448 t = quoted = store_get(Ustrlen(s) + count + 1);
449
450 while ((c = *s++) != 0)
451 {
452 if (c == '\'')
453 {
454 *t++ = '\'';
455 *t++ = '\'';
456 }
457 else if (Ustrchr("\n\t\r\b\"\\", c) != NULL)
458 {
459 *t++ = '\\';
460 switch(c)
461 {
462 case '\n': *t++ = 'n';
463 break;
464 case '\t': *t++ = 't';
465 break;
466 case '\r': *t++ = 'r';
467 break;
468 case '\b': *t++ = 'b';
469 break;
470 default: *t++ = c;
471 break;
472 }
473 }
474 else *t++ = c;
475 }
476
477 *t = 0;
478 return quoted;
479 }
480
481
482 /*************************************************
483 * Version reporting entry point *
484 *************************************************/
485
486 /* See local README for interface description. */
487
488 #include "../version.h"
489
490 void
491 pgsql_version_report(FILE *f)
492 {
493 #ifdef DYNLOOKUP
494 fprintf(f, "Library version: PostgreSQL: Exim version %s\n", EXIM_VERSION_STR);
495 #endif
496
497 /* Version reporting: there appears to be no available information about
498 the client library in libpq-fe.h; once you have a connection object, you
499 can access the server version and the chosen protocol version, but those
500 aren't really what we want. It might make sense to debug_printf those
501 when the connection is established though? */
502 }
503
504
505 static lookup_info _lookup_info = {
506 US"pgsql", /* lookup name */
507 lookup_querystyle, /* query-style lookup */
508 pgsql_open, /* open function */
509 NULL, /* no check function */
510 pgsql_find, /* find function */
511 NULL, /* no close function */
512 pgsql_tidy, /* tidy function */
513 pgsql_quote, /* quoting function */
514 pgsql_version_report /* version reporting */
515 };
516
517 #ifdef DYNLOOKUP
518 #define pgsql_lookup_module_info _lookup_module_info
519 #endif
520
521 static lookup_info *_lookup_list[] = { &_lookup_info };
522 lookup_module_info pgsql_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
523
524 /* End of lookups/pgsql.c */