| 1 | /* $Cambridge: exim/src/src/lookups/pgsql.c,v 1.10 2007/08/23 10:16:51 ph10 Exp $ */ |
| 2 | |
| 3 | /************************************************* |
| 4 | * Exim - an Internet mail transport agent * |
| 5 | *************************************************/ |
| 6 | |
| 7 | /* Copyright (c) University of Cambridge 1995 - 2007 */ |
| 8 | /* See the file NOTICE for conditions of use and distribution. */ |
| 9 | |
| 10 | /* Thanks to Petr Cech for contributing the original code for these |
| 11 | functions. Thanks to Joachim Wieland for the initial patch for the Unix domain |
| 12 | socket extension. */ |
| 13 | |
| 14 | #include "../exim.h" |
| 15 | #include "lf_functions.h" |
| 16 | #include "pgsql.h" /* The local header */ |
| 17 | |
| 18 | /* We can't just compile this code and allow the library mechanism to omit the |
| 19 | functions if they are not wanted, because we need to have the PGSQL header |
| 20 | available for compiling. Therefore, compile these functions only if |
| 21 | LOOKUP_PGSQL is defined. However, some compilers don't like compiling empty |
| 22 | modules, so keep them happy with a dummy when skipping the rest. Make it |
| 23 | reference itself to stop picky compilers complaining that it is unused, and put |
| 24 | in a dummy argument to stop even pickier compilers complaining about infinite |
| 25 | loops. */ |
| 26 | |
| 27 | #ifndef LOOKUP_PGSQL |
| 28 | static void dummy(int x) { dummy(x-1); } |
| 29 | #else |
| 30 | |
| 31 | |
| 32 | #include <libpq-fe.h> /* The system header */ |
| 33 | |
| 34 | /* Structure and anchor for caching connections. */ |
| 35 | |
| 36 | typedef struct pgsql_connection { |
| 37 | struct pgsql_connection *next; |
| 38 | uschar *server; |
| 39 | PGconn *handle; |
| 40 | } pgsql_connection; |
| 41 | |
| 42 | static pgsql_connection *pgsql_connections = NULL; |
| 43 | |
| 44 | |
| 45 | |
| 46 | /************************************************* |
| 47 | * Open entry point * |
| 48 | *************************************************/ |
| 49 | |
| 50 | /* See local README for interface description. */ |
| 51 | |
| 52 | void * |
| 53 | pgsql_open(uschar *filename, uschar **errmsg) |
| 54 | { |
| 55 | return (void *)(1); /* Just return something non-null */ |
| 56 | } |
| 57 | |
| 58 | |
| 59 | |
| 60 | /************************************************* |
| 61 | * Tidy entry point * |
| 62 | *************************************************/ |
| 63 | |
| 64 | /* See local README for interface description. */ |
| 65 | |
| 66 | void |
| 67 | pgsql_tidy(void) |
| 68 | { |
| 69 | pgsql_connection *cn; |
| 70 | while ((cn = pgsql_connections) != NULL) |
| 71 | { |
| 72 | pgsql_connections = cn->next; |
| 73 | DEBUG(D_lookup) debug_printf("close PGSQL connection: %s\n", cn->server); |
| 74 | PQfinish(cn->handle); |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | |
| 79 | /************************************************* |
| 80 | * Notice processor function for pgsql * |
| 81 | *************************************************/ |
| 82 | |
| 83 | /* This function is passed to pgsql below, and called for any PostgreSQL |
| 84 | "notices". By default they are written to stderr, which is undesirable. |
| 85 | |
| 86 | Arguments: |
| 87 | arg an opaque user cookie (not used) |
| 88 | message the notice |
| 89 | |
| 90 | Returns: nothing |
| 91 | */ |
| 92 | |
| 93 | static void |
| 94 | notice_processor(void *arg, const char *message) |
| 95 | { |
| 96 | arg = arg; /* Keep compiler happy */ |
| 97 | DEBUG(D_lookup) debug_printf("PGSQL: %s\n", message); |
| 98 | } |
| 99 | |
| 100 | |
| 101 | |
| 102 | /************************************************* |
| 103 | * Internal search function * |
| 104 | *************************************************/ |
| 105 | |
| 106 | /* This function is called from the find entry point to do the search for a |
| 107 | single server. The server string is of the form "server/dbname/user/password". |
| 108 | |
| 109 | PostgreSQL supports connections through Unix domain sockets. This is usually |
| 110 | faster and costs less cpu time than a TCP/IP connection. However it can only be |
| 111 | used if the mail server runs on the same machine as the database server. A |
| 112 | configuration line for PostgreSQL via Unix domain sockets looks like this: |
| 113 | |
| 114 | hide pgsql_servers = (/tmp/.s.PGSQL.5432)/db/user/password[:<nextserver>] |
| 115 | |
| 116 | We enclose the path name in parentheses so that its slashes aren't visually |
| 117 | confused with the delimeters for the other pgsql_server settings. |
| 118 | |
| 119 | For TCP/IP connections, the server is a host name and optional port (with a |
| 120 | colon separator). |
| 121 | |
| 122 | NOTE: |
| 123 | 1) All three '/' must be present. |
| 124 | 2) If host is omitted the local unix socket is used. |
| 125 | |
| 126 | Arguments: |
| 127 | query the query string |
| 128 | server the server string; this is in dynamic memory and can be updated |
| 129 | resultptr where to store the result |
| 130 | errmsg where to point an error message |
| 131 | defer_break set TRUE if no more servers are to be tried after DEFER |
| 132 | do_cache set FALSE if data is changed |
| 133 | |
| 134 | Returns: OK, FAIL, or DEFER |
| 135 | */ |
| 136 | |
| 137 | static int |
| 138 | perform_pgsql_search(uschar *query, uschar *server, uschar **resultptr, |
| 139 | uschar **errmsg, BOOL *defer_break, BOOL *do_cache) |
| 140 | { |
| 141 | PGconn *pg_conn = NULL; |
| 142 | PGresult *pg_result = NULL; |
| 143 | |
| 144 | int i; |
| 145 | int ssize = 0; |
| 146 | int offset = 0; |
| 147 | int yield = DEFER; |
| 148 | unsigned int num_fields, num_tuples; |
| 149 | uschar *result = NULL; |
| 150 | pgsql_connection *cn; |
| 151 | uschar *server_copy = NULL; |
| 152 | uschar *sdata[3]; |
| 153 | |
| 154 | /* Disaggregate the parameters from the server argument. The order is host or |
| 155 | path, database, user, password. We can write to the string, since it is in a |
| 156 | nextinlist temporary buffer. The copy of the string that is used for caching |
| 157 | has the password removed. This copy is also used for debugging output. */ |
| 158 | |
| 159 | for (i = 2; i >= 0; i--) |
| 160 | { |
| 161 | uschar *pp = Ustrrchr(server, '/'); |
| 162 | if (pp == NULL) |
| 163 | { |
| 164 | *errmsg = string_sprintf("incomplete pgSQL server data: %s", |
| 165 | (i == 2)? server : server_copy); |
| 166 | *defer_break = TRUE; |
| 167 | return DEFER; |
| 168 | } |
| 169 | *pp++ = 0; |
| 170 | sdata[i] = pp; |
| 171 | if (i == 2) server_copy = string_copy(server); /* sans password */ |
| 172 | } |
| 173 | |
| 174 | /* The total server string has now been truncated so that what is left at the |
| 175 | start is the identification of the server (host or path). See if we have a |
| 176 | cached connection to the server. */ |
| 177 | |
| 178 | for (cn = pgsql_connections; cn != NULL; cn = cn->next) |
| 179 | { |
| 180 | if (Ustrcmp(cn->server, server_copy) == 0) |
| 181 | { |
| 182 | pg_conn = cn->handle; |
| 183 | break; |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | /* If there is no cached connection, we must set one up. */ |
| 188 | |
| 189 | if (cn == NULL) |
| 190 | { |
| 191 | uschar *port = US""; |
| 192 | |
| 193 | /* For a Unix domain socket connection, the path is in parentheses */ |
| 194 | |
| 195 | if (*server == '(') |
| 196 | { |
| 197 | uschar *last_slash, *last_dot, *p; |
| 198 | |
| 199 | p = ++server; |
| 200 | while (*p != 0 && *p != ')') p++; |
| 201 | *p = 0; |
| 202 | |
| 203 | last_slash = Ustrrchr(server, '/'); |
| 204 | last_dot = Ustrrchr(server, '.'); |
| 205 | |
| 206 | DEBUG(D_lookup) debug_printf("PGSQL new connection: socket=%s " |
| 207 | "database=%s user=%s\n", server, sdata[0], sdata[1]); |
| 208 | |
| 209 | /* A valid socket name looks like this: /var/run/postgresql/.s.PGSQL.5432 |
| 210 | We have to call PQsetdbLogin with '/var/run/postgresql' as the hostname |
| 211 | argument and put '5432' into the port variable. */ |
| 212 | |
| 213 | if (last_slash == NULL || last_dot == NULL) |
| 214 | { |
| 215 | *errmsg = string_sprintf("PGSQL invalid filename for socket: %s", |
| 216 | server); |
| 217 | *defer_break = TRUE; |
| 218 | return DEFER; |
| 219 | } |
| 220 | |
| 221 | /* Terminate the path name and set up the port: we'll have something like |
| 222 | server = "/var/run/postgresql" and port = "5432". */ |
| 223 | |
| 224 | *last_slash = 0; |
| 225 | port = last_dot + 1; |
| 226 | } |
| 227 | |
| 228 | /* Host connection; sort out the port */ |
| 229 | |
| 230 | else |
| 231 | { |
| 232 | uschar *p; |
| 233 | if ((p = Ustrchr(server, ':')) != NULL) |
| 234 | { |
| 235 | *p++ = 0; |
| 236 | port = p; |
| 237 | } |
| 238 | |
| 239 | if (Ustrchr(server, '/') != NULL) |
| 240 | { |
| 241 | *errmsg = string_sprintf("unexpected slash in pgSQL server hostname: %s", |
| 242 | server); |
| 243 | *defer_break = TRUE; |
| 244 | return DEFER; |
| 245 | } |
| 246 | |
| 247 | DEBUG(D_lookup) debug_printf("PGSQL new connection: host=%s port=%s " |
| 248 | "database=%s user=%s\n", server, port, sdata[0], sdata[1]); |
| 249 | } |
| 250 | |
| 251 | /* If the database is the empty string, set it NULL - the query must then |
| 252 | define it. */ |
| 253 | |
| 254 | if (sdata[0][0] == 0) sdata[0] = NULL; |
| 255 | |
| 256 | /* Get store for a new handle, initialize it, and connect to the server */ |
| 257 | |
| 258 | pg_conn=PQsetdbLogin( |
| 259 | /* host port options tty database user passwd */ |
| 260 | CS server, CS port, NULL, NULL, CS sdata[0], CS sdata[1], CS sdata[2]); |
| 261 | |
| 262 | if(PQstatus(pg_conn) == CONNECTION_BAD) |
| 263 | { |
| 264 | store_reset(server_copy); |
| 265 | *errmsg = string_sprintf("PGSQL connection failed: %s", |
| 266 | PQerrorMessage(pg_conn)); |
| 267 | PQfinish(pg_conn); |
| 268 | goto PGSQL_EXIT; |
| 269 | } |
| 270 | |
| 271 | /* Set the client encoding to SQL_ASCII, which means that the server will |
| 272 | not try to interpret the query as being in any fancy encoding such as UTF-8 |
| 273 | or other multibyte code that might cause problems with escaping. */ |
| 274 | |
| 275 | PQsetClientEncoding(pg_conn, "SQL_ASCII"); |
| 276 | |
| 277 | /* Set the notice processor to prevent notices from being written to stderr |
| 278 | (which is what the default does). Our function (above) just produces debug |
| 279 | output. */ |
| 280 | |
| 281 | PQsetNoticeProcessor(pg_conn, notice_processor, NULL); |
| 282 | |
| 283 | /* Add the connection to the cache */ |
| 284 | |
| 285 | cn = store_get(sizeof(pgsql_connection)); |
| 286 | cn->server = server_copy; |
| 287 | cn->handle = pg_conn; |
| 288 | cn->next = pgsql_connections; |
| 289 | pgsql_connections = cn; |
| 290 | } |
| 291 | |
| 292 | /* Else use a previously cached connection */ |
| 293 | |
| 294 | else |
| 295 | { |
| 296 | DEBUG(D_lookup) debug_printf("PGSQL using cached connection for %s\n", |
| 297 | server_copy); |
| 298 | } |
| 299 | |
| 300 | /* Run the query */ |
| 301 | |
| 302 | pg_result = PQexec(pg_conn, CS query); |
| 303 | switch(PQresultStatus(pg_result)) |
| 304 | { |
| 305 | case PGRES_EMPTY_QUERY: |
| 306 | case PGRES_COMMAND_OK: |
| 307 | /* The command was successful but did not return any data since it was |
| 308 | * not SELECT but either an INSERT, UPDATE or DELETE statement. Tell the |
| 309 | * high level code to not cache this query, and clean the current cache for |
| 310 | * this handle by setting *do_cache FALSE. */ |
| 311 | result = string_copy(US PQcmdTuples(pg_result)); |
| 312 | offset = Ustrlen(result); |
| 313 | *do_cache = FALSE; |
| 314 | DEBUG(D_lookup) debug_printf("PGSQL: command does not return any data " |
| 315 | "but was successful. Rows affected: %s\n", result); |
| 316 | |
| 317 | case PGRES_TUPLES_OK: |
| 318 | break; |
| 319 | |
| 320 | default: |
| 321 | /* This was the original code: |
| 322 | *errmsg = string_sprintf("PGSQL: query failed: %s\n", |
| 323 | PQresultErrorMessage(pg_result)); |
| 324 | This was suggested by a user: |
| 325 | */ |
| 326 | |
| 327 | *errmsg = string_sprintf("PGSQL: query failed: %s (%s) (%s)\n", |
| 328 | PQresultErrorMessage(pg_result), |
| 329 | PQresStatus(PQresultStatus(pg_result)), query); |
| 330 | goto PGSQL_EXIT; |
| 331 | } |
| 332 | |
| 333 | /* Result is in pg_result. Find the number of fields returned. If this is one, |
| 334 | we don't add field names to the data. Otherwise we do. If the query did not |
| 335 | return anything we skip the for loop; this also applies to the case |
| 336 | PGRES_COMMAND_OK. */ |
| 337 | |
| 338 | num_fields = PQnfields(pg_result); |
| 339 | num_tuples = PQntuples(pg_result); |
| 340 | |
| 341 | /* Get the fields and construct the result string. If there is more than one |
| 342 | row, we insert '\n' between them. */ |
| 343 | |
| 344 | for (i = 0; i < num_tuples; i++) |
| 345 | { |
| 346 | if (result != NULL) |
| 347 | result = string_cat(result, &ssize, &offset, US"\n", 1); |
| 348 | |
| 349 | if (num_fields == 1) |
| 350 | { |
| 351 | result = string_cat(result, &ssize, &offset, |
| 352 | US PQgetvalue(pg_result, i, 0), PQgetlength(pg_result, i, 0)); |
| 353 | } |
| 354 | |
| 355 | else |
| 356 | { |
| 357 | int j; |
| 358 | for (j = 0; j < num_fields; j++) |
| 359 | { |
| 360 | uschar *tmp = US PQgetvalue(pg_result, i, j); |
| 361 | result = lf_quote(US PQfname(pg_result, j), tmp, Ustrlen(tmp), result, |
| 362 | &ssize, &offset); |
| 363 | } |
| 364 | } |
| 365 | } |
| 366 | |
| 367 | /* If result is NULL then no data has been found and so we return FAIL. |
| 368 | Otherwise, we must terminate the string which has been built; string_cat() |
| 369 | always leaves enough room for a terminating zero. */ |
| 370 | |
| 371 | if (result == NULL) |
| 372 | { |
| 373 | yield = FAIL; |
| 374 | *errmsg = US"PGSQL: no data found"; |
| 375 | } |
| 376 | else |
| 377 | { |
| 378 | result[offset] = 0; |
| 379 | store_reset(result + offset + 1); |
| 380 | } |
| 381 | |
| 382 | /* Get here by goto from various error checks. */ |
| 383 | |
| 384 | PGSQL_EXIT: |
| 385 | |
| 386 | /* Free store for any result that was got; don't close the connection, as |
| 387 | it is cached. */ |
| 388 | |
| 389 | if (pg_result != NULL) PQclear(pg_result); |
| 390 | |
| 391 | /* Non-NULL result indicates a sucessful result */ |
| 392 | |
| 393 | if (result != NULL) |
| 394 | { |
| 395 | *resultptr = result; |
| 396 | return OK; |
| 397 | } |
| 398 | else |
| 399 | { |
| 400 | DEBUG(D_lookup) debug_printf("%s\n", *errmsg); |
| 401 | return yield; /* FAIL or DEFER */ |
| 402 | } |
| 403 | } |
| 404 | |
| 405 | |
| 406 | |
| 407 | |
| 408 | /************************************************* |
| 409 | * Find entry point * |
| 410 | *************************************************/ |
| 411 | |
| 412 | /* See local README for interface description. The handle and filename |
| 413 | arguments are not used. The code to loop through a list of servers while the |
| 414 | query is deferred with a retryable error is now in a separate function that is |
| 415 | shared with other SQL lookups. */ |
| 416 | |
| 417 | int |
| 418 | pgsql_find(void *handle, uschar *filename, uschar *query, int length, |
| 419 | uschar **result, uschar **errmsg, BOOL *do_cache) |
| 420 | { |
| 421 | return lf_sqlperform(US"PostgreSQL", US"pgsql_servers", pgsql_servers, query, |
| 422 | result, errmsg, do_cache, perform_pgsql_search); |
| 423 | } |
| 424 | |
| 425 | |
| 426 | |
| 427 | /************************************************* |
| 428 | * Quote entry point * |
| 429 | *************************************************/ |
| 430 | |
| 431 | /* The characters that always need to be quoted (with backslash) are newline, |
| 432 | tab, carriage return, backspace, backslash itself, and the quote characters. |
| 433 | Percent and underscore are only special in contexts where they can be wild |
| 434 | cards, and this isn't usually the case for data inserted from messages, since |
| 435 | that isn't likely to be treated as a pattern of any kind. However, pgsql seems |
| 436 | to allow escaping "on spec". If you use something like "where id="ab\%cd" it |
| 437 | does treat the string as "ab%cd". So we can safely quote percent and |
| 438 | underscore. [This is different to MySQL, where you can't do this.] |
| 439 | |
| 440 | The original code quoted single quotes as \' which is documented as valid in |
| 441 | the O'Reilly book "Practical PostgreSQL" (first edition) as an alternative to |
| 442 | the SQL standard '' way of representing a single quote as data. However, in |
| 443 | June 2006 there was some security issue with using \' and so this has been |
| 444 | changed. |
| 445 | |
| 446 | [Note: There is a function called PQescapeStringConn() that quotes strings. |
| 447 | This cannot be used because it needs a PGconn argument (the connection handle). |
| 448 | Why, I don't know. Seems odd for just string escaping...] |
| 449 | |
| 450 | Arguments: |
| 451 | s the string to be quoted |
| 452 | opt additional option text or NULL if none |
| 453 | |
| 454 | Returns: the processed string or NULL for a bad option |
| 455 | */ |
| 456 | |
| 457 | uschar * |
| 458 | pgsql_quote(uschar *s, uschar *opt) |
| 459 | { |
| 460 | register int c; |
| 461 | int count = 0; |
| 462 | uschar *t = s; |
| 463 | uschar *quoted; |
| 464 | |
| 465 | if (opt != NULL) return NULL; /* No options recognized */ |
| 466 | |
| 467 | while ((c = *t++) != 0) |
| 468 | if (Ustrchr("\n\t\r\b\'\"\\%_", c) != NULL) count++; |
| 469 | |
| 470 | if (count == 0) return s; |
| 471 | t = quoted = store_get(Ustrlen(s) + count + 1); |
| 472 | |
| 473 | while ((c = *s++) != 0) |
| 474 | { |
| 475 | if (c == '\'') |
| 476 | { |
| 477 | *t++ = '\''; |
| 478 | *t++ = '\''; |
| 479 | } |
| 480 | else if (Ustrchr("\n\t\r\b\"\\%_", c) != NULL) |
| 481 | { |
| 482 | *t++ = '\\'; |
| 483 | switch(c) |
| 484 | { |
| 485 | case '\n': *t++ = 'n'; |
| 486 | break; |
| 487 | case '\t': *t++ = 't'; |
| 488 | break; |
| 489 | case '\r': *t++ = 'r'; |
| 490 | break; |
| 491 | case '\b': *t++ = 'b'; |
| 492 | break; |
| 493 | default: *t++ = c; |
| 494 | break; |
| 495 | } |
| 496 | } |
| 497 | else *t++ = c; |
| 498 | } |
| 499 | |
| 500 | *t = 0; |
| 501 | return quoted; |
| 502 | } |
| 503 | |
| 504 | #endif /* PGSQL_LOOKUP */ |
| 505 | |
| 506 | /* End of lookups/pgsql.c */ |