Line data Source code
1 : /*
2 : * dblink.c
3 : *
4 : * Functions returning results from a remote database
5 : *
6 : * Joe Conway <mail@joeconway.com>
7 : * And contributors:
8 : * Darko Prenosil <Darko.Prenosil@finteh.hr>
9 : * Shridhar Daithankar <shridhar_daithankar@persistent.co.in>
10 : *
11 : * contrib/dblink/dblink.c
12 : * Copyright (c) 2001-2026, PostgreSQL Global Development Group
13 : * ALL RIGHTS RESERVED;
14 : *
15 : * Permission to use, copy, modify, and distribute this software and its
16 : * documentation for any purpose, without fee, and without a written agreement
17 : * is hereby granted, provided that the above copyright notice and this
18 : * paragraph and the following two paragraphs appear in all copies.
19 : *
20 : * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
21 : * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
22 : * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
23 : * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
24 : * POSSIBILITY OF SUCH DAMAGE.
25 : *
26 : * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
27 : * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
28 : * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
29 : * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
30 : * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
31 : *
32 : */
33 : #include "postgres.h"
34 :
35 : #include <limits.h>
36 :
37 : #include "access/htup_details.h"
38 : #include "access/relation.h"
39 : #include "access/reloptions.h"
40 : #include "access/table.h"
41 : #include "catalog/namespace.h"
42 : #include "catalog/pg_foreign_data_wrapper.h"
43 : #include "catalog/pg_foreign_server.h"
44 : #include "catalog/pg_type.h"
45 : #include "catalog/pg_user_mapping.h"
46 : #include "commands/defrem.h"
47 : #include "common/base64.h"
48 : #include "executor/spi.h"
49 : #include "foreign/foreign.h"
50 : #include "funcapi.h"
51 : #include "lib/stringinfo.h"
52 : #include "libpq-fe.h"
53 : #include "libpq/libpq-be.h"
54 : #include "libpq/libpq-be-fe-helpers.h"
55 : #include "mb/pg_wchar.h"
56 : #include "miscadmin.h"
57 : #include "parser/scansup.h"
58 : #include "utils/acl.h"
59 : #include "utils/builtins.h"
60 : #include "utils/fmgroids.h"
61 : #include "utils/guc.h"
62 : #include "utils/lsyscache.h"
63 : #include "utils/memutils.h"
64 : #include "utils/rel.h"
65 : #include "utils/varlena.h"
66 : #include "utils/wait_event.h"
67 :
68 16 : PG_MODULE_MAGIC_EXT(
69 : .name = "dblink",
70 : .version = PG_VERSION
71 : );
72 :
73 : typedef struct remoteConn
74 : {
75 : PGconn *conn; /* Hold the remote connection */
76 : int openCursorCount; /* The number of open cursors */
77 : bool newXactForCursor; /* Opened a transaction for a cursor */
78 : } remoteConn;
79 :
80 : typedef struct storeInfo
81 : {
82 : FunctionCallInfo fcinfo;
83 : Tuplestorestate *tuplestore;
84 : AttInMetadata *attinmeta;
85 : MemoryContext tmpcontext;
86 : char **cstrs;
87 : /* temp storage for results to avoid leaks on exception */
88 : PGresult *last_res;
89 : PGresult *cur_res;
90 : } storeInfo;
91 :
92 : /*
93 : * Internal declarations
94 : */
95 : static Datum dblink_record_internal(FunctionCallInfo fcinfo, bool is_async);
96 : static void prepTuplestoreResult(FunctionCallInfo fcinfo);
97 : static void materializeResult(FunctionCallInfo fcinfo, PGconn *conn,
98 : PGresult *res);
99 : static void materializeQueryResult(FunctionCallInfo fcinfo,
100 : PGconn *conn,
101 : const char *conname,
102 : const char *sql,
103 : bool fail);
104 : static PGresult *storeQueryResult(storeInfo *sinfo, PGconn *conn, const char *sql);
105 : static void storeRow(storeInfo *sinfo, PGresult *res, bool first);
106 : static remoteConn *getConnectionByName(const char *name);
107 : static HTAB *createConnHash(void);
108 : static remoteConn *createNewConnection(const char *name);
109 : static void deleteConnection(const char *name);
110 : static char **get_pkey_attnames(Relation rel, int16 *indnkeyatts);
111 : static char **get_text_array_contents(ArrayType *array, int *numitems);
112 : static char *get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals);
113 : static char *get_sql_delete(Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals);
114 : static char *get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals);
115 : static char *quote_ident_cstr(char *rawstr);
116 : static int get_attnum_pk_pos(int *pkattnums, int pknumatts, int key);
117 : static HeapTuple get_tuple_of_interest(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals);
118 : static Relation get_rel_from_relname(text *relname_text, LOCKMODE lockmode, AclMode aclmode);
119 : static char *generate_relation_name(Relation rel);
120 : static void dblink_connstr_check(const char *connstr);
121 : static bool dblink_connstr_has_pw(const char *connstr);
122 : static void dblink_security_check(PGconn *conn, const char *connname,
123 : const char *connstr);
124 : static void dblink_res_error(PGconn *conn, const char *conname, PGresult *res,
125 : bool fail, const char *fmt,...) pg_attribute_printf(5, 6);
126 : static char *get_connect_string(const char *servername);
127 : static char *escape_param_str(const char *str);
128 : static void validate_pkattnums(Relation rel,
129 : int2vector *pkattnums_arg, int32 pknumatts_arg,
130 : int **pkattnums, int *pknumatts);
131 : static bool is_valid_dblink_option(const PQconninfoOption *options,
132 : const char *option, Oid context);
133 : static int applyRemoteGucs(PGconn *conn);
134 : static void restoreLocalGucs(int nestlevel);
135 : static bool UseScramPassthrough(ForeignServer *foreign_server, UserMapping *user);
136 : static void appendSCRAMKeysInfo(StringInfo buf);
137 : static bool is_valid_dblink_fdw_option(const PQconninfoOption *options, const char *option,
138 : Oid context);
139 : static bool dblink_connstr_has_required_scram_options(const char *connstr);
140 :
141 : /* Global */
142 : static remoteConn *pconn = NULL;
143 : static HTAB *remoteConnHash = NULL;
144 :
145 : /* custom wait event values, retrieved from shared memory */
146 : static uint32 dblink_we_connect = 0;
147 : static uint32 dblink_we_get_conn = 0;
148 : static uint32 dblink_we_get_result = 0;
149 :
150 : /*
151 : * Following is hash that holds multiple remote connections.
152 : * Calling convention of each dblink function changes to accept
153 : * connection name as the first parameter. The connection hash is
154 : * much like ecpg e.g. a mapping between a name and a PGconn object.
155 : *
156 : * To avoid potentially leaking a PGconn object in case of out-of-memory
157 : * errors, we first create the hash entry, then open the PGconn.
158 : * Hence, a hash entry whose rconn.conn pointer is NULL must be
159 : * understood as a leftover from a failed create; it should be ignored
160 : * by lookup operations, and silently replaced by create operations.
161 : */
162 :
163 : typedef struct remoteConnHashEnt
164 : {
165 : char name[NAMEDATALEN];
166 : remoteConn rconn;
167 : } remoteConnHashEnt;
168 :
169 : /* initial number of connection hashes */
170 : #define NUMCONN 16
171 :
172 : pg_noreturn static void
173 0 : dblink_res_internalerror(PGconn *conn, PGresult *res, const char *p2)
174 : {
175 0 : char *msg = pchomp(PQerrorMessage(conn));
176 :
177 0 : PQclear(res);
178 0 : elog(ERROR, "%s: %s", p2, msg);
179 : }
180 :
181 : pg_noreturn static void
182 3 : dblink_conn_not_avail(const char *conname)
183 : {
184 3 : if (conname)
185 1 : ereport(ERROR,
186 : (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
187 : errmsg("connection \"%s\" not available", conname)));
188 : else
189 2 : ereport(ERROR,
190 : (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
191 : errmsg("connection not available")));
192 : }
193 :
194 : static void
195 36 : dblink_get_conn(char *conname_or_str,
196 : PGconn *volatile *conn_p, char **conname_p, volatile bool *freeconn_p)
197 : {
198 36 : remoteConn *rconn = getConnectionByName(conname_or_str);
199 : PGconn *conn;
200 : char *conname;
201 : bool freeconn;
202 :
203 36 : if (rconn)
204 : {
205 27 : conn = rconn->conn;
206 27 : conname = conname_or_str;
207 27 : freeconn = false;
208 : }
209 : else
210 : {
211 : const char *connstr;
212 :
213 9 : connstr = get_connect_string(conname_or_str);
214 9 : if (connstr == NULL)
215 6 : connstr = conname_or_str;
216 9 : dblink_connstr_check(connstr);
217 :
218 : /* first time, allocate or get the custom wait event */
219 8 : if (dblink_we_get_conn == 0)
220 4 : dblink_we_get_conn = WaitEventExtensionNew("DblinkGetConnect");
221 :
222 : /* OK to make connection */
223 8 : conn = libpqsrv_connect(connstr, dblink_we_get_conn);
224 :
225 8 : if (PQstatus(conn) == CONNECTION_BAD)
226 : {
227 2 : char *msg = pchomp(PQerrorMessage(conn));
228 :
229 2 : libpqsrv_disconnect(conn);
230 2 : ereport(ERROR,
231 : (errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
232 : errmsg("could not establish connection"),
233 : errdetail_internal("%s", msg)));
234 : }
235 :
236 6 : PQsetNoticeReceiver(conn, libpqsrv_notice_receiver,
237 : "received message via remote connection");
238 :
239 6 : dblink_security_check(conn, NULL, connstr);
240 6 : if (PQclientEncoding(conn) != GetDatabaseEncoding())
241 0 : PQsetClientEncoding(conn, GetDatabaseEncodingName());
242 6 : freeconn = true;
243 6 : conname = NULL;
244 : }
245 :
246 33 : *conn_p = conn;
247 33 : *conname_p = conname;
248 33 : *freeconn_p = freeconn;
249 33 : }
250 :
251 : static PGconn *
252 17 : dblink_get_named_conn(const char *conname)
253 : {
254 17 : remoteConn *rconn = getConnectionByName(conname);
255 :
256 17 : if (rconn)
257 17 : return rconn->conn;
258 :
259 0 : dblink_conn_not_avail(conname);
260 : return NULL; /* keep compiler quiet */
261 : }
262 :
263 : static void
264 123 : dblink_init(void)
265 : {
266 123 : if (!pconn)
267 : {
268 6 : if (dblink_we_get_result == 0)
269 6 : dblink_we_get_result = WaitEventExtensionNew("DblinkGetResult");
270 :
271 6 : pconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext, sizeof(remoteConn));
272 6 : pconn->conn = NULL;
273 6 : pconn->openCursorCount = 0;
274 6 : pconn->newXactForCursor = false;
275 : }
276 123 : }
277 :
278 : /*
279 : * Create a persistent connection to another database
280 : */
281 13 : PG_FUNCTION_INFO_V1(dblink_connect);
282 : Datum
283 16 : dblink_connect(PG_FUNCTION_ARGS)
284 : {
285 16 : char *conname_or_str = NULL;
286 16 : char *connstr = NULL;
287 16 : char *connname = NULL;
288 : char *msg;
289 16 : PGconn *conn = NULL;
290 16 : remoteConn *rconn = NULL;
291 :
292 16 : dblink_init();
293 :
294 16 : if (PG_NARGS() == 2)
295 : {
296 11 : conname_or_str = text_to_cstring(PG_GETARG_TEXT_PP(1));
297 11 : connname = text_to_cstring(PG_GETARG_TEXT_PP(0));
298 : }
299 5 : else if (PG_NARGS() == 1)
300 5 : conname_or_str = text_to_cstring(PG_GETARG_TEXT_PP(0));
301 :
302 : /* first check for valid foreign data server */
303 16 : connstr = get_connect_string(conname_or_str);
304 16 : if (connstr == NULL)
305 14 : connstr = conname_or_str;
306 :
307 : /* check password in connection string if not superuser */
308 16 : dblink_connstr_check(connstr);
309 :
310 : /* first time, allocate or get the custom wait event */
311 15 : if (dblink_we_connect == 0)
312 2 : dblink_we_connect = WaitEventExtensionNew("DblinkConnect");
313 :
314 : /* if we need a hashtable entry, make that first, since it might fail */
315 15 : if (connname)
316 : {
317 10 : rconn = createNewConnection(connname);
318 : Assert(rconn->conn == NULL);
319 : }
320 :
321 : /* OK to make connection */
322 14 : conn = libpqsrv_connect(connstr, dblink_we_connect);
323 :
324 14 : if (PQstatus(conn) == CONNECTION_BAD)
325 : {
326 0 : msg = pchomp(PQerrorMessage(conn));
327 0 : libpqsrv_disconnect(conn);
328 0 : if (connname)
329 0 : deleteConnection(connname);
330 :
331 0 : ereport(ERROR,
332 : (errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
333 : errmsg("could not establish connection"),
334 : errdetail_internal("%s", msg)));
335 : }
336 :
337 14 : PQsetNoticeReceiver(conn, libpqsrv_notice_receiver,
338 : "received message via remote connection");
339 :
340 : /* check password actually used if not superuser */
341 14 : dblink_security_check(conn, connname, connstr);
342 :
343 : /* attempt to set client encoding to match server encoding, if needed */
344 14 : if (PQclientEncoding(conn) != GetDatabaseEncoding())
345 0 : PQsetClientEncoding(conn, GetDatabaseEncodingName());
346 :
347 : /* all OK, save away the conn */
348 14 : if (connname)
349 : {
350 9 : rconn->conn = conn;
351 : }
352 : else
353 : {
354 5 : if (pconn->conn)
355 1 : libpqsrv_disconnect(pconn->conn);
356 5 : pconn->conn = conn;
357 : }
358 :
359 14 : PG_RETURN_TEXT_P(cstring_to_text("OK"));
360 : }
361 :
362 : /*
363 : * Clear a persistent connection to another database
364 : */
365 8 : PG_FUNCTION_INFO_V1(dblink_disconnect);
366 : Datum
367 13 : dblink_disconnect(PG_FUNCTION_ARGS)
368 : {
369 13 : char *conname = NULL;
370 13 : remoteConn *rconn = NULL;
371 13 : PGconn *conn = NULL;
372 :
373 13 : dblink_init();
374 :
375 13 : if (PG_NARGS() == 1)
376 : {
377 9 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
378 9 : rconn = getConnectionByName(conname);
379 9 : if (rconn)
380 8 : conn = rconn->conn;
381 : }
382 : else
383 4 : conn = pconn->conn;
384 :
385 13 : if (!conn)
386 1 : dblink_conn_not_avail(conname);
387 :
388 12 : libpqsrv_disconnect(conn);
389 12 : if (rconn)
390 8 : deleteConnection(conname);
391 : else
392 4 : pconn->conn = NULL;
393 :
394 12 : PG_RETURN_TEXT_P(cstring_to_text("OK"));
395 : }
396 :
397 : /*
398 : * opens a cursor using a persistent connection
399 : */
400 13 : PG_FUNCTION_INFO_V1(dblink_open);
401 : Datum
402 9 : dblink_open(PG_FUNCTION_ARGS)
403 : {
404 9 : PGresult *res = NULL;
405 : PGconn *conn;
406 9 : char *curname = NULL;
407 9 : char *sql = NULL;
408 9 : char *conname = NULL;
409 : StringInfoData buf;
410 9 : remoteConn *rconn = NULL;
411 9 : bool fail = true; /* default to backward compatible behavior */
412 :
413 9 : dblink_init();
414 9 : initStringInfo(&buf);
415 :
416 9 : if (PG_NARGS() == 2)
417 : {
418 : /* text,text */
419 2 : curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
420 2 : sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
421 2 : rconn = pconn;
422 : }
423 7 : else if (PG_NARGS() == 3)
424 : {
425 : /* might be text,text,text or text,text,bool */
426 6 : if (get_fn_expr_argtype(fcinfo->flinfo, 2) == BOOLOID)
427 : {
428 1 : curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
429 1 : sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
430 1 : fail = PG_GETARG_BOOL(2);
431 1 : rconn = pconn;
432 : }
433 : else
434 : {
435 5 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
436 5 : curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
437 5 : sql = text_to_cstring(PG_GETARG_TEXT_PP(2));
438 5 : rconn = getConnectionByName(conname);
439 : }
440 : }
441 1 : else if (PG_NARGS() == 4)
442 : {
443 : /* text,text,text,bool */
444 1 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
445 1 : curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
446 1 : sql = text_to_cstring(PG_GETARG_TEXT_PP(2));
447 1 : fail = PG_GETARG_BOOL(3);
448 1 : rconn = getConnectionByName(conname);
449 : }
450 :
451 9 : if (!rconn || !rconn->conn)
452 0 : dblink_conn_not_avail(conname);
453 :
454 9 : conn = rconn->conn;
455 :
456 : /* If we are not in a transaction, start one */
457 9 : if (PQtransactionStatus(conn) == PQTRANS_IDLE)
458 : {
459 7 : res = libpqsrv_exec(conn, "BEGIN", dblink_we_get_result);
460 7 : if (PQresultStatus(res) != PGRES_COMMAND_OK)
461 0 : dblink_res_internalerror(conn, res, "begin error");
462 7 : PQclear(res);
463 7 : rconn->newXactForCursor = true;
464 :
465 : /*
466 : * Since transaction state was IDLE, we force cursor count to
467 : * initially be 0. This is needed as a previous ABORT might have wiped
468 : * out our transaction without maintaining the cursor count for us.
469 : */
470 7 : rconn->openCursorCount = 0;
471 : }
472 :
473 : /* if we started a transaction, increment cursor count */
474 9 : if (rconn->newXactForCursor)
475 9 : (rconn->openCursorCount)++;
476 :
477 9 : appendStringInfo(&buf, "DECLARE %s CURSOR FOR %s", curname, sql);
478 9 : res = libpqsrv_exec(conn, buf.data, dblink_we_get_result);
479 9 : if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
480 : {
481 2 : dblink_res_error(conn, conname, res, fail,
482 : "while opening cursor \"%s\"", curname);
483 2 : PG_RETURN_TEXT_P(cstring_to_text("ERROR"));
484 : }
485 :
486 7 : PQclear(res);
487 7 : PG_RETURN_TEXT_P(cstring_to_text("OK"));
488 : }
489 :
490 : /*
491 : * closes a cursor
492 : */
493 10 : PG_FUNCTION_INFO_V1(dblink_close);
494 : Datum
495 5 : dblink_close(PG_FUNCTION_ARGS)
496 : {
497 : PGconn *conn;
498 5 : PGresult *res = NULL;
499 5 : char *curname = NULL;
500 5 : char *conname = NULL;
501 : StringInfoData buf;
502 5 : remoteConn *rconn = NULL;
503 5 : bool fail = true; /* default to backward compatible behavior */
504 :
505 5 : dblink_init();
506 5 : initStringInfo(&buf);
507 :
508 5 : if (PG_NARGS() == 1)
509 : {
510 : /* text */
511 0 : curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
512 0 : rconn = pconn;
513 : }
514 5 : else if (PG_NARGS() == 2)
515 : {
516 : /* might be text,text or text,bool */
517 5 : if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
518 : {
519 2 : curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
520 2 : fail = PG_GETARG_BOOL(1);
521 2 : rconn = pconn;
522 : }
523 : else
524 : {
525 3 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
526 3 : curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
527 3 : rconn = getConnectionByName(conname);
528 : }
529 : }
530 5 : if (PG_NARGS() == 3)
531 : {
532 : /* text,text,bool */
533 0 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
534 0 : curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
535 0 : fail = PG_GETARG_BOOL(2);
536 0 : rconn = getConnectionByName(conname);
537 : }
538 :
539 5 : if (!rconn || !rconn->conn)
540 0 : dblink_conn_not_avail(conname);
541 :
542 5 : conn = rconn->conn;
543 :
544 5 : appendStringInfo(&buf, "CLOSE %s", curname);
545 :
546 : /* close the cursor */
547 5 : res = libpqsrv_exec(conn, buf.data, dblink_we_get_result);
548 5 : if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
549 : {
550 1 : dblink_res_error(conn, conname, res, fail,
551 : "while closing cursor \"%s\"", curname);
552 1 : PG_RETURN_TEXT_P(cstring_to_text("ERROR"));
553 : }
554 :
555 4 : PQclear(res);
556 :
557 : /* if we started a transaction, decrement cursor count */
558 4 : if (rconn->newXactForCursor)
559 : {
560 4 : (rconn->openCursorCount)--;
561 :
562 : /* if count is zero, commit the transaction */
563 4 : if (rconn->openCursorCount == 0)
564 : {
565 2 : rconn->newXactForCursor = false;
566 :
567 2 : res = libpqsrv_exec(conn, "COMMIT", dblink_we_get_result);
568 2 : if (PQresultStatus(res) != PGRES_COMMAND_OK)
569 0 : dblink_res_internalerror(conn, res, "commit error");
570 2 : PQclear(res);
571 : }
572 : }
573 :
574 4 : PG_RETURN_TEXT_P(cstring_to_text("OK"));
575 : }
576 :
577 : /*
578 : * Fetch results from an open cursor
579 : */
580 13 : PG_FUNCTION_INFO_V1(dblink_fetch);
581 : Datum
582 13 : dblink_fetch(PG_FUNCTION_ARGS)
583 : {
584 13 : PGresult *res = NULL;
585 13 : char *conname = NULL;
586 13 : remoteConn *rconn = NULL;
587 13 : PGconn *conn = NULL;
588 : StringInfoData buf;
589 13 : char *curname = NULL;
590 13 : int howmany = 0;
591 13 : bool fail = true; /* default to backward compatible */
592 :
593 13 : prepTuplestoreResult(fcinfo);
594 :
595 13 : dblink_init();
596 :
597 13 : if (PG_NARGS() == 4)
598 : {
599 : /* text,text,int,bool */
600 1 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
601 1 : curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
602 1 : howmany = PG_GETARG_INT32(2);
603 1 : fail = PG_GETARG_BOOL(3);
604 :
605 1 : rconn = getConnectionByName(conname);
606 1 : if (rconn)
607 1 : conn = rconn->conn;
608 : }
609 12 : else if (PG_NARGS() == 3)
610 : {
611 : /* text,text,int or text,int,bool */
612 8 : if (get_fn_expr_argtype(fcinfo->flinfo, 2) == BOOLOID)
613 : {
614 2 : curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
615 2 : howmany = PG_GETARG_INT32(1);
616 2 : fail = PG_GETARG_BOOL(2);
617 2 : conn = pconn->conn;
618 : }
619 : else
620 : {
621 6 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
622 6 : curname = text_to_cstring(PG_GETARG_TEXT_PP(1));
623 6 : howmany = PG_GETARG_INT32(2);
624 :
625 6 : rconn = getConnectionByName(conname);
626 6 : if (rconn)
627 6 : conn = rconn->conn;
628 : }
629 : }
630 4 : else if (PG_NARGS() == 2)
631 : {
632 : /* text,int */
633 4 : curname = text_to_cstring(PG_GETARG_TEXT_PP(0));
634 4 : howmany = PG_GETARG_INT32(1);
635 4 : conn = pconn->conn;
636 : }
637 :
638 13 : if (!conn)
639 0 : dblink_conn_not_avail(conname);
640 :
641 13 : initStringInfo(&buf);
642 13 : appendStringInfo(&buf, "FETCH %d FROM %s", howmany, curname);
643 :
644 : /*
645 : * Try to execute the query. Note that since libpq uses malloc, the
646 : * PGresult will be long-lived even though we are still in a short-lived
647 : * memory context.
648 : */
649 13 : res = libpqsrv_exec(conn, buf.data, dblink_we_get_result);
650 26 : if (!res ||
651 26 : (PQresultStatus(res) != PGRES_COMMAND_OK &&
652 13 : PQresultStatus(res) != PGRES_TUPLES_OK))
653 : {
654 5 : dblink_res_error(conn, conname, res, fail,
655 : "while fetching from cursor \"%s\"", curname);
656 3 : return (Datum) 0;
657 : }
658 8 : else if (PQresultStatus(res) == PGRES_COMMAND_OK)
659 : {
660 : /* cursor does not exist - closed already or bad name */
661 0 : PQclear(res);
662 0 : ereport(ERROR,
663 : (errcode(ERRCODE_INVALID_CURSOR_NAME),
664 : errmsg("cursor \"%s\" does not exist", curname)));
665 : }
666 :
667 8 : materializeResult(fcinfo, conn, res);
668 7 : return (Datum) 0;
669 : }
670 :
671 : /*
672 : * Note: this is the new preferred version of dblink
673 : */
674 18 : PG_FUNCTION_INFO_V1(dblink_record);
675 : Datum
676 28 : dblink_record(PG_FUNCTION_ARGS)
677 : {
678 28 : return dblink_record_internal(fcinfo, false);
679 : }
680 :
681 4 : PG_FUNCTION_INFO_V1(dblink_send_query);
682 : Datum
683 6 : dblink_send_query(PG_FUNCTION_ARGS)
684 : {
685 : PGconn *conn;
686 : char *sql;
687 : int retval;
688 :
689 6 : if (PG_NARGS() == 2)
690 : {
691 6 : conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
692 6 : sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
693 : }
694 : else
695 : /* shouldn't happen */
696 0 : elog(ERROR, "wrong number of arguments");
697 :
698 : /* async query send */
699 6 : retval = PQsendQuery(conn, sql);
700 6 : if (retval != 1)
701 0 : elog(NOTICE, "could not send query: %s", pchomp(PQerrorMessage(conn)));
702 :
703 6 : PG_RETURN_INT32(retval);
704 : }
705 :
706 6 : PG_FUNCTION_INFO_V1(dblink_get_result);
707 : Datum
708 8 : dblink_get_result(PG_FUNCTION_ARGS)
709 : {
710 8 : return dblink_record_internal(fcinfo, true);
711 : }
712 :
713 : static Datum
714 36 : dblink_record_internal(FunctionCallInfo fcinfo, bool is_async)
715 : {
716 36 : PGconn *volatile conn = NULL;
717 36 : volatile bool freeconn = false;
718 :
719 36 : prepTuplestoreResult(fcinfo);
720 :
721 36 : dblink_init();
722 :
723 36 : PG_TRY();
724 : {
725 36 : char *sql = NULL;
726 36 : char *conname = NULL;
727 36 : bool fail = true; /* default to backward compatible */
728 :
729 36 : if (!is_async)
730 : {
731 28 : if (PG_NARGS() == 3)
732 : {
733 : /* text,text,bool */
734 1 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
735 1 : sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
736 1 : fail = PG_GETARG_BOOL(2);
737 1 : dblink_get_conn(conname, &conn, &conname, &freeconn);
738 : }
739 27 : else if (PG_NARGS() == 2)
740 : {
741 : /* text,text or text,bool */
742 20 : if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
743 : {
744 1 : sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
745 1 : fail = PG_GETARG_BOOL(1);
746 1 : conn = pconn->conn;
747 : }
748 : else
749 : {
750 19 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
751 19 : sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
752 19 : dblink_get_conn(conname, &conn, &conname, &freeconn);
753 : }
754 : }
755 7 : else if (PG_NARGS() == 1)
756 : {
757 : /* text */
758 7 : conn = pconn->conn;
759 7 : sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
760 : }
761 : else
762 : /* shouldn't happen */
763 0 : elog(ERROR, "wrong number of arguments");
764 : }
765 : else /* is_async */
766 : {
767 : /* get async result */
768 8 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
769 :
770 8 : if (PG_NARGS() == 2)
771 : {
772 : /* text,bool */
773 0 : fail = PG_GETARG_BOOL(1);
774 0 : conn = dblink_get_named_conn(conname);
775 : }
776 8 : else if (PG_NARGS() == 1)
777 : {
778 : /* text */
779 8 : conn = dblink_get_named_conn(conname);
780 : }
781 : else
782 : /* shouldn't happen */
783 0 : elog(ERROR, "wrong number of arguments");
784 : }
785 :
786 33 : if (!conn)
787 2 : dblink_conn_not_avail(conname);
788 :
789 31 : if (!is_async)
790 : {
791 : /* synchronous query, use efficient tuple collection method */
792 23 : materializeQueryResult(fcinfo, conn, conname, sql, fail);
793 : }
794 : else
795 : {
796 : /* async result retrieval, do it the old way */
797 8 : PGresult *res = libpqsrv_get_result(conn, dblink_we_get_result);
798 :
799 : /* NULL means we're all done with the async results */
800 8 : if (res)
801 : {
802 5 : if (PQresultStatus(res) != PGRES_COMMAND_OK &&
803 5 : PQresultStatus(res) != PGRES_TUPLES_OK)
804 : {
805 0 : dblink_res_error(conn, conname, res, fail,
806 : "while executing query");
807 : /* if fail isn't set, we'll return an empty query result */
808 : }
809 : else
810 : {
811 5 : materializeResult(fcinfo, conn, res);
812 : }
813 : }
814 : }
815 : }
816 5 : PG_FINALLY();
817 : {
818 : /* if needed, close the connection to the database */
819 36 : if (freeconn)
820 5 : libpqsrv_disconnect(conn);
821 : }
822 36 : PG_END_TRY();
823 :
824 31 : return (Datum) 0;
825 : }
826 :
827 : /*
828 : * Verify function caller can handle a tuplestore result, and set up for that.
829 : *
830 : * Note: if the caller returns without actually creating a tuplestore, the
831 : * executor will treat the function result as an empty set.
832 : */
833 : static void
834 49 : prepTuplestoreResult(FunctionCallInfo fcinfo)
835 : {
836 49 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
837 :
838 : /* check to see if query supports us returning a tuplestore */
839 49 : if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
840 0 : ereport(ERROR,
841 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
842 : errmsg("set-valued function called in context that cannot accept a set")));
843 49 : if (!(rsinfo->allowedModes & SFRM_Materialize))
844 0 : ereport(ERROR,
845 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
846 : errmsg("materialize mode required, but it is not allowed in this context")));
847 :
848 : /* let the executor know we're sending back a tuplestore */
849 49 : rsinfo->returnMode = SFRM_Materialize;
850 :
851 : /* caller must fill these to return a non-empty result */
852 49 : rsinfo->setResult = NULL;
853 49 : rsinfo->setDesc = NULL;
854 49 : }
855 :
856 : /*
857 : * Copy the contents of the PGresult into a tuplestore to be returned
858 : * as the result of the current function.
859 : * The PGresult will be released in this function.
860 : */
861 : static void
862 13 : materializeResult(FunctionCallInfo fcinfo, PGconn *conn, PGresult *res)
863 : {
864 13 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
865 : TupleDesc tupdesc;
866 : bool is_sql_cmd;
867 : int ntuples;
868 : int nfields;
869 :
870 : /* prepTuplestoreResult must have been called previously */
871 : Assert(rsinfo->returnMode == SFRM_Materialize);
872 :
873 13 : if (PQresultStatus(res) == PGRES_COMMAND_OK)
874 : {
875 0 : is_sql_cmd = true;
876 :
877 : /*
878 : * need a tuple descriptor representing one TEXT column to return the
879 : * command status string as our result tuple
880 : */
881 0 : tupdesc = CreateTemplateTupleDesc(1);
882 0 : TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status",
883 : TEXTOID, -1, 0);
884 0 : ntuples = 1;
885 0 : nfields = 1;
886 : }
887 : else
888 : {
889 : Assert(PQresultStatus(res) == PGRES_TUPLES_OK);
890 :
891 13 : is_sql_cmd = false;
892 :
893 : /* get a tuple descriptor for our result type */
894 13 : switch (get_call_result_type(fcinfo, NULL, &tupdesc))
895 : {
896 13 : case TYPEFUNC_COMPOSITE:
897 : /* success */
898 13 : break;
899 0 : case TYPEFUNC_RECORD:
900 : /* failed to determine actual type of RECORD */
901 0 : ereport(ERROR,
902 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
903 : errmsg("function returning record called in context "
904 : "that cannot accept type record")));
905 : break;
906 0 : default:
907 : /* result type isn't composite */
908 0 : elog(ERROR, "return type must be a row type");
909 : break;
910 : }
911 :
912 : /* make sure we have a persistent copy of the tupdesc */
913 13 : tupdesc = CreateTupleDescCopy(tupdesc);
914 13 : ntuples = PQntuples(res);
915 13 : nfields = PQnfields(res);
916 : }
917 :
918 : /*
919 : * check result and tuple descriptor have the same number of columns
920 : */
921 13 : if (nfields != tupdesc->natts)
922 0 : ereport(ERROR,
923 : (errcode(ERRCODE_DATATYPE_MISMATCH),
924 : errmsg("remote query result rowtype does not match "
925 : "the specified FROM clause rowtype")));
926 :
927 13 : if (ntuples > 0)
928 : {
929 : AttInMetadata *attinmeta;
930 13 : int nestlevel = -1;
931 : Tuplestorestate *tupstore;
932 : MemoryContext oldcontext;
933 : int row;
934 : char **values;
935 :
936 13 : attinmeta = TupleDescGetAttInMetadata(tupdesc);
937 :
938 : /* Set GUCs to ensure we read GUC-sensitive data types correctly */
939 13 : if (!is_sql_cmd)
940 13 : nestlevel = applyRemoteGucs(conn);
941 :
942 13 : oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
943 13 : tupstore = tuplestore_begin_heap(true, false, work_mem);
944 13 : rsinfo->setResult = tupstore;
945 13 : rsinfo->setDesc = tupdesc;
946 13 : MemoryContextSwitchTo(oldcontext);
947 :
948 13 : values = palloc_array(char *, nfields);
949 :
950 : /* put all tuples into the tuplestore */
951 49 : for (row = 0; row < ntuples; row++)
952 : {
953 : HeapTuple tuple;
954 :
955 37 : if (!is_sql_cmd)
956 : {
957 : int i;
958 :
959 138 : for (i = 0; i < nfields; i++)
960 : {
961 101 : if (PQgetisnull(res, row, i))
962 0 : values[i] = NULL;
963 : else
964 101 : values[i] = PQgetvalue(res, row, i);
965 : }
966 : }
967 : else
968 : {
969 0 : values[0] = PQcmdStatus(res);
970 : }
971 :
972 : /* build the tuple and put it into the tuplestore. */
973 37 : tuple = BuildTupleFromCStrings(attinmeta, values);
974 36 : tuplestore_puttuple(tupstore, tuple);
975 : }
976 :
977 : /* clean up GUC settings, if we changed any */
978 12 : restoreLocalGucs(nestlevel);
979 : }
980 :
981 12 : PQclear(res);
982 12 : }
983 :
984 : /*
985 : * Execute the given SQL command and store its results into a tuplestore
986 : * to be returned as the result of the current function.
987 : *
988 : * This is equivalent to PQexec followed by materializeResult, but we make
989 : * use of libpq's single-row mode to avoid accumulating the whole result
990 : * inside libpq before it gets transferred to the tuplestore.
991 : */
992 : static void
993 23 : materializeQueryResult(FunctionCallInfo fcinfo,
994 : PGconn *conn,
995 : const char *conname,
996 : const char *sql,
997 : bool fail)
998 : {
999 23 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
1000 :
1001 : /* prepTuplestoreResult must have been called previously */
1002 : Assert(rsinfo->returnMode == SFRM_Materialize);
1003 :
1004 : /* Use a PG_TRY block to ensure we pump libpq dry of results */
1005 23 : PG_TRY();
1006 : {
1007 23 : storeInfo sinfo = {0};
1008 : PGresult *res;
1009 :
1010 23 : sinfo.fcinfo = fcinfo;
1011 : /* Create short-lived memory context for data conversions */
1012 23 : sinfo.tmpcontext = AllocSetContextCreate(CurrentMemoryContext,
1013 : "dblink temporary context",
1014 : ALLOCSET_DEFAULT_SIZES);
1015 :
1016 : /* execute query, collecting any tuples into the tuplestore */
1017 23 : res = storeQueryResult(&sinfo, conn, sql);
1018 :
1019 23 : if (!res ||
1020 23 : (PQresultStatus(res) != PGRES_COMMAND_OK &&
1021 23 : PQresultStatus(res) != PGRES_TUPLES_OK))
1022 : {
1023 2 : dblink_res_error(conn, conname, res, fail,
1024 : "while executing query");
1025 : /* if fail isn't set, we'll return an empty query result */
1026 : }
1027 21 : else if (PQresultStatus(res) == PGRES_COMMAND_OK)
1028 : {
1029 : /*
1030 : * storeRow didn't get called, so we need to convert the command
1031 : * status string to a tuple manually
1032 : */
1033 : TupleDesc tupdesc;
1034 : AttInMetadata *attinmeta;
1035 : Tuplestorestate *tupstore;
1036 : HeapTuple tuple;
1037 : char *values[1];
1038 : MemoryContext oldcontext;
1039 :
1040 : /*
1041 : * need a tuple descriptor representing one TEXT column to return
1042 : * the command status string as our result tuple
1043 : */
1044 0 : tupdesc = CreateTemplateTupleDesc(1);
1045 0 : TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status",
1046 : TEXTOID, -1, 0);
1047 0 : attinmeta = TupleDescGetAttInMetadata(tupdesc);
1048 :
1049 0 : oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
1050 0 : tupstore = tuplestore_begin_heap(true, false, work_mem);
1051 0 : rsinfo->setResult = tupstore;
1052 0 : rsinfo->setDesc = tupdesc;
1053 0 : MemoryContextSwitchTo(oldcontext);
1054 :
1055 0 : values[0] = PQcmdStatus(res);
1056 :
1057 : /* build the tuple and put it into the tuplestore. */
1058 0 : tuple = BuildTupleFromCStrings(attinmeta, values);
1059 0 : tuplestore_puttuple(tupstore, tuple);
1060 :
1061 0 : PQclear(res);
1062 : }
1063 : else
1064 : {
1065 : Assert(PQresultStatus(res) == PGRES_TUPLES_OK);
1066 : /* storeRow should have created a tuplestore */
1067 : Assert(rsinfo->setResult != NULL);
1068 :
1069 21 : PQclear(res);
1070 : }
1071 :
1072 : /* clean up data conversion short-lived memory context */
1073 23 : if (sinfo.tmpcontext != NULL)
1074 23 : MemoryContextDelete(sinfo.tmpcontext);
1075 :
1076 23 : PQclear(sinfo.last_res);
1077 23 : PQclear(sinfo.cur_res);
1078 : }
1079 0 : PG_CATCH();
1080 : {
1081 : PGresult *res;
1082 :
1083 : /* be sure to clear out any pending data in libpq */
1084 0 : while ((res = libpqsrv_get_result(conn, dblink_we_get_result)) !=
1085 : NULL)
1086 0 : PQclear(res);
1087 0 : PG_RE_THROW();
1088 : }
1089 23 : PG_END_TRY();
1090 23 : }
1091 :
1092 : /*
1093 : * Execute query, and send any result rows to sinfo->tuplestore.
1094 : */
1095 : static PGresult *
1096 23 : storeQueryResult(storeInfo *sinfo, PGconn *conn, const char *sql)
1097 : {
1098 23 : bool first = true;
1099 23 : int nestlevel = -1;
1100 : PGresult *res;
1101 :
1102 23 : if (!PQsendQuery(conn, sql))
1103 0 : elog(ERROR, "could not send query: %s", pchomp(PQerrorMessage(conn)));
1104 :
1105 23 : if (!PQsetSingleRowMode(conn)) /* shouldn't fail */
1106 0 : elog(ERROR, "failed to set single-row mode for dblink query");
1107 :
1108 : for (;;)
1109 : {
1110 198 : CHECK_FOR_INTERRUPTS();
1111 :
1112 198 : sinfo->cur_res = libpqsrv_get_result(conn, dblink_we_get_result);
1113 198 : if (!sinfo->cur_res)
1114 23 : break;
1115 :
1116 175 : if (PQresultStatus(sinfo->cur_res) == PGRES_SINGLE_TUPLE)
1117 : {
1118 : /* got one row from possibly-bigger resultset */
1119 :
1120 : /*
1121 : * Set GUCs to ensure we read GUC-sensitive data types correctly.
1122 : * We shouldn't do this until we have a row in hand, to ensure
1123 : * libpq has seen any earlier ParameterStatus protocol messages.
1124 : */
1125 152 : if (first && nestlevel < 0)
1126 21 : nestlevel = applyRemoteGucs(conn);
1127 :
1128 152 : storeRow(sinfo, sinfo->cur_res, first);
1129 :
1130 152 : PQclear(sinfo->cur_res);
1131 152 : sinfo->cur_res = NULL;
1132 152 : first = false;
1133 : }
1134 : else
1135 : {
1136 : /* if empty resultset, fill tuplestore header */
1137 23 : if (first && PQresultStatus(sinfo->cur_res) == PGRES_TUPLES_OK)
1138 0 : storeRow(sinfo, sinfo->cur_res, first);
1139 :
1140 : /* store completed result at last_res */
1141 23 : PQclear(sinfo->last_res);
1142 23 : sinfo->last_res = sinfo->cur_res;
1143 23 : sinfo->cur_res = NULL;
1144 23 : first = true;
1145 : }
1146 : }
1147 :
1148 : /* clean up GUC settings, if we changed any */
1149 23 : restoreLocalGucs(nestlevel);
1150 :
1151 : /* return last_res */
1152 23 : res = sinfo->last_res;
1153 23 : sinfo->last_res = NULL;
1154 23 : return res;
1155 : }
1156 :
1157 : /*
1158 : * Send single row to sinfo->tuplestore.
1159 : *
1160 : * If "first" is true, create the tuplestore using PGresult's metadata
1161 : * (in this case the PGresult might contain either zero or one row).
1162 : */
1163 : static void
1164 152 : storeRow(storeInfo *sinfo, PGresult *res, bool first)
1165 : {
1166 152 : int nfields = PQnfields(res);
1167 : HeapTuple tuple;
1168 : int i;
1169 : MemoryContext oldcontext;
1170 :
1171 152 : if (first)
1172 : {
1173 : /* Prepare for new result set */
1174 21 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) sinfo->fcinfo->resultinfo;
1175 : TupleDesc tupdesc;
1176 :
1177 : /*
1178 : * It's possible to get more than one result set if the query string
1179 : * contained multiple SQL commands. In that case, we follow PQexec's
1180 : * traditional behavior of throwing away all but the last result.
1181 : */
1182 21 : if (sinfo->tuplestore)
1183 0 : tuplestore_end(sinfo->tuplestore);
1184 21 : sinfo->tuplestore = NULL;
1185 :
1186 : /* get a tuple descriptor for our result type */
1187 21 : switch (get_call_result_type(sinfo->fcinfo, NULL, &tupdesc))
1188 : {
1189 21 : case TYPEFUNC_COMPOSITE:
1190 : /* success */
1191 21 : break;
1192 0 : case TYPEFUNC_RECORD:
1193 : /* failed to determine actual type of RECORD */
1194 0 : ereport(ERROR,
1195 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1196 : errmsg("function returning record called in context "
1197 : "that cannot accept type record")));
1198 : break;
1199 0 : default:
1200 : /* result type isn't composite */
1201 0 : elog(ERROR, "return type must be a row type");
1202 : break;
1203 : }
1204 :
1205 : /* make sure we have a persistent copy of the tupdesc */
1206 21 : tupdesc = CreateTupleDescCopy(tupdesc);
1207 :
1208 : /* check result and tuple descriptor have the same number of columns */
1209 21 : if (nfields != tupdesc->natts)
1210 0 : ereport(ERROR,
1211 : (errcode(ERRCODE_DATATYPE_MISMATCH),
1212 : errmsg("remote query result rowtype does not match "
1213 : "the specified FROM clause rowtype")));
1214 :
1215 : /* Prepare attinmeta for later data conversions */
1216 21 : sinfo->attinmeta = TupleDescGetAttInMetadata(tupdesc);
1217 :
1218 : /* Create a new, empty tuplestore */
1219 21 : oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
1220 21 : sinfo->tuplestore = tuplestore_begin_heap(true, false, work_mem);
1221 21 : rsinfo->setResult = sinfo->tuplestore;
1222 21 : rsinfo->setDesc = tupdesc;
1223 21 : MemoryContextSwitchTo(oldcontext);
1224 :
1225 : /* Done if empty resultset */
1226 21 : if (PQntuples(res) == 0)
1227 0 : return;
1228 :
1229 : /*
1230 : * Set up sufficiently-wide string pointers array; this won't change
1231 : * in size so it's easy to preallocate.
1232 : */
1233 21 : if (sinfo->cstrs)
1234 0 : pfree(sinfo->cstrs);
1235 21 : sinfo->cstrs = palloc_array(char *, nfields);
1236 : }
1237 :
1238 : /* Should have a single-row result if we get here */
1239 : Assert(PQntuples(res) == 1);
1240 :
1241 : /*
1242 : * Do the following work in a temp context that we reset after each tuple.
1243 : * This cleans up not only the data we have direct access to, but any
1244 : * cruft the I/O functions might leak.
1245 : */
1246 152 : oldcontext = MemoryContextSwitchTo(sinfo->tmpcontext);
1247 :
1248 : /*
1249 : * Fill cstrs with null-terminated strings of column values.
1250 : */
1251 570 : for (i = 0; i < nfields; i++)
1252 : {
1253 418 : if (PQgetisnull(res, 0, i))
1254 0 : sinfo->cstrs[i] = NULL;
1255 : else
1256 418 : sinfo->cstrs[i] = PQgetvalue(res, 0, i);
1257 : }
1258 :
1259 : /* Convert row to a tuple, and add it to the tuplestore */
1260 152 : tuple = BuildTupleFromCStrings(sinfo->attinmeta, sinfo->cstrs);
1261 :
1262 152 : tuplestore_puttuple(sinfo->tuplestore, tuple);
1263 :
1264 : /* Clean up */
1265 152 : MemoryContextSwitchTo(oldcontext);
1266 152 : MemoryContextReset(sinfo->tmpcontext);
1267 : }
1268 :
1269 : /*
1270 : * List all open dblink connections by name.
1271 : * Returns an array of all connection names.
1272 : * Takes no params
1273 : */
1274 3 : PG_FUNCTION_INFO_V1(dblink_get_connections);
1275 : Datum
1276 1 : dblink_get_connections(PG_FUNCTION_ARGS)
1277 : {
1278 : HASH_SEQ_STATUS status;
1279 : remoteConnHashEnt *hentry;
1280 1 : ArrayBuildState *astate = NULL;
1281 :
1282 1 : if (remoteConnHash)
1283 : {
1284 1 : hash_seq_init(&status, remoteConnHash);
1285 4 : while ((hentry = (remoteConnHashEnt *) hash_seq_search(&status)) != NULL)
1286 : {
1287 : /* ignore it if it's not an open connection */
1288 3 : if (hentry->rconn.conn == NULL)
1289 0 : continue;
1290 : /* stash away current value */
1291 3 : astate = accumArrayResult(astate,
1292 3 : CStringGetTextDatum(hentry->name),
1293 : false, TEXTOID, CurrentMemoryContext);
1294 : }
1295 : }
1296 :
1297 1 : if (astate)
1298 1 : PG_RETURN_DATUM(makeArrayResult(astate,
1299 : CurrentMemoryContext));
1300 : else
1301 0 : PG_RETURN_NULL();
1302 : }
1303 :
1304 : /*
1305 : * Checks if a given remote connection is busy
1306 : *
1307 : * Returns 1 if the connection is busy, 0 otherwise
1308 : * Params:
1309 : * text connection_name - name of the connection to check
1310 : *
1311 : */
1312 3 : PG_FUNCTION_INFO_V1(dblink_is_busy);
1313 : Datum
1314 1 : dblink_is_busy(PG_FUNCTION_ARGS)
1315 : {
1316 : PGconn *conn;
1317 :
1318 1 : dblink_init();
1319 1 : conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
1320 :
1321 1 : PQconsumeInput(conn);
1322 1 : PG_RETURN_INT32(PQisBusy(conn));
1323 : }
1324 :
1325 : /*
1326 : * Cancels a running request on a connection
1327 : *
1328 : * Returns text:
1329 : * "OK" if the cancel request has been sent correctly,
1330 : * an error message otherwise
1331 : *
1332 : * Params:
1333 : * text connection_name - name of the connection to check
1334 : *
1335 : */
1336 3 : PG_FUNCTION_INFO_V1(dblink_cancel_query);
1337 : Datum
1338 1 : dblink_cancel_query(PG_FUNCTION_ARGS)
1339 : {
1340 : PGconn *conn;
1341 : const char *msg;
1342 : TimestampTz endtime;
1343 :
1344 1 : dblink_init();
1345 1 : conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
1346 1 : endtime = TimestampTzPlusMilliseconds(GetCurrentTimestamp(),
1347 : 30000);
1348 1 : msg = libpqsrv_cancel(conn, endtime);
1349 1 : if (msg == NULL)
1350 1 : msg = "OK";
1351 :
1352 1 : PG_RETURN_TEXT_P(cstring_to_text(msg));
1353 : }
1354 :
1355 :
1356 : /*
1357 : * Get error message from a connection
1358 : *
1359 : * Returns text:
1360 : * "OK" if no error, an error message otherwise
1361 : *
1362 : * Params:
1363 : * text connection_name - name of the connection to check
1364 : *
1365 : */
1366 3 : PG_FUNCTION_INFO_V1(dblink_error_message);
1367 : Datum
1368 1 : dblink_error_message(PG_FUNCTION_ARGS)
1369 : {
1370 : char *msg;
1371 : PGconn *conn;
1372 :
1373 1 : dblink_init();
1374 1 : conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
1375 :
1376 1 : msg = PQerrorMessage(conn);
1377 1 : if (msg == NULL || msg[0] == '\0')
1378 1 : PG_RETURN_TEXT_P(cstring_to_text("OK"));
1379 : else
1380 0 : PG_RETURN_TEXT_P(cstring_to_text(pchomp(msg)));
1381 : }
1382 :
1383 : /*
1384 : * Execute an SQL non-SELECT command
1385 : */
1386 13 : PG_FUNCTION_INFO_V1(dblink_exec);
1387 : Datum
1388 26 : dblink_exec(PG_FUNCTION_ARGS)
1389 : {
1390 26 : text *volatile sql_cmd_status = NULL;
1391 26 : PGconn *volatile conn = NULL;
1392 26 : volatile bool freeconn = false;
1393 :
1394 26 : dblink_init();
1395 :
1396 26 : PG_TRY();
1397 : {
1398 26 : PGresult *res = NULL;
1399 26 : char *sql = NULL;
1400 26 : char *conname = NULL;
1401 26 : bool fail = true; /* default to backward compatible behavior */
1402 :
1403 26 : if (PG_NARGS() == 3)
1404 : {
1405 : /* must be text,text,bool */
1406 0 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
1407 0 : sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
1408 0 : fail = PG_GETARG_BOOL(2);
1409 0 : dblink_get_conn(conname, &conn, &conname, &freeconn);
1410 : }
1411 26 : else if (PG_NARGS() == 2)
1412 : {
1413 : /* might be text,text or text,bool */
1414 17 : if (get_fn_expr_argtype(fcinfo->flinfo, 1) == BOOLOID)
1415 : {
1416 1 : sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
1417 1 : fail = PG_GETARG_BOOL(1);
1418 1 : conn = pconn->conn;
1419 : }
1420 : else
1421 : {
1422 16 : conname = text_to_cstring(PG_GETARG_TEXT_PP(0));
1423 16 : sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
1424 16 : dblink_get_conn(conname, &conn, &conname, &freeconn);
1425 : }
1426 : }
1427 9 : else if (PG_NARGS() == 1)
1428 : {
1429 : /* must be single text argument */
1430 9 : conn = pconn->conn;
1431 9 : sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
1432 : }
1433 : else
1434 : /* shouldn't happen */
1435 0 : elog(ERROR, "wrong number of arguments");
1436 :
1437 26 : if (!conn)
1438 0 : dblink_conn_not_avail(conname);
1439 :
1440 26 : res = libpqsrv_exec(conn, sql, dblink_we_get_result);
1441 26 : if (!res ||
1442 26 : (PQresultStatus(res) != PGRES_COMMAND_OK &&
1443 2 : PQresultStatus(res) != PGRES_TUPLES_OK))
1444 : {
1445 2 : dblink_res_error(conn, conname, res, fail,
1446 : "while executing command");
1447 :
1448 : /*
1449 : * and save a copy of the command status string to return as our
1450 : * result tuple
1451 : */
1452 1 : sql_cmd_status = cstring_to_text("ERROR");
1453 : }
1454 24 : else if (PQresultStatus(res) == PGRES_COMMAND_OK)
1455 : {
1456 : /*
1457 : * and save a copy of the command status string to return as our
1458 : * result tuple
1459 : */
1460 24 : sql_cmd_status = cstring_to_text(PQcmdStatus(res));
1461 24 : PQclear(res);
1462 : }
1463 : else
1464 : {
1465 0 : PQclear(res);
1466 0 : ereport(ERROR,
1467 : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
1468 : errmsg("statement returning results not allowed")));
1469 : }
1470 : }
1471 1 : PG_FINALLY();
1472 : {
1473 : /* if needed, close the connection to the database */
1474 26 : if (freeconn)
1475 1 : libpqsrv_disconnect(conn);
1476 : }
1477 26 : PG_END_TRY();
1478 :
1479 25 : PG_RETURN_TEXT_P(sql_cmd_status);
1480 : }
1481 :
1482 :
1483 : /*
1484 : * dblink_get_pkey
1485 : *
1486 : * Return list of primary key fields for the supplied relation,
1487 : * or NULL if none exists.
1488 : */
1489 3 : PG_FUNCTION_INFO_V1(dblink_get_pkey);
1490 : Datum
1491 9 : dblink_get_pkey(PG_FUNCTION_ARGS)
1492 : {
1493 : int16 indnkeyatts;
1494 : char **results;
1495 : FuncCallContext *funcctx;
1496 : int32 call_cntr;
1497 : int32 max_calls;
1498 : AttInMetadata *attinmeta;
1499 : MemoryContext oldcontext;
1500 :
1501 : /* stuff done only on the first call of the function */
1502 9 : if (SRF_IS_FIRSTCALL())
1503 : {
1504 : Relation rel;
1505 : TupleDesc tupdesc;
1506 :
1507 : /* create a function context for cross-call persistence */
1508 3 : funcctx = SRF_FIRSTCALL_INIT();
1509 :
1510 : /*
1511 : * switch to memory context appropriate for multiple function calls
1512 : */
1513 3 : oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
1514 :
1515 : /* open target relation */
1516 3 : rel = get_rel_from_relname(PG_GETARG_TEXT_PP(0), AccessShareLock, ACL_SELECT);
1517 :
1518 : /* get the array of attnums */
1519 3 : results = get_pkey_attnames(rel, &indnkeyatts);
1520 :
1521 3 : relation_close(rel, AccessShareLock);
1522 :
1523 : /*
1524 : * need a tuple descriptor representing one INT and one TEXT column
1525 : */
1526 3 : tupdesc = CreateTemplateTupleDesc(2);
1527 3 : TupleDescInitEntry(tupdesc, (AttrNumber) 1, "position",
1528 : INT4OID, -1, 0);
1529 3 : TupleDescInitEntry(tupdesc, (AttrNumber) 2, "colname",
1530 : TEXTOID, -1, 0);
1531 :
1532 : /*
1533 : * Generate attribute metadata needed later to produce tuples from raw
1534 : * C strings
1535 : */
1536 3 : attinmeta = TupleDescGetAttInMetadata(tupdesc);
1537 3 : funcctx->attinmeta = attinmeta;
1538 :
1539 3 : if ((results != NULL) && (indnkeyatts > 0))
1540 : {
1541 3 : funcctx->max_calls = indnkeyatts;
1542 :
1543 : /* got results, keep track of them */
1544 3 : funcctx->user_fctx = results;
1545 : }
1546 : else
1547 : {
1548 : /* fast track when no results */
1549 0 : MemoryContextSwitchTo(oldcontext);
1550 0 : SRF_RETURN_DONE(funcctx);
1551 : }
1552 :
1553 3 : MemoryContextSwitchTo(oldcontext);
1554 : }
1555 :
1556 : /* stuff done on every call of the function */
1557 9 : funcctx = SRF_PERCALL_SETUP();
1558 :
1559 : /*
1560 : * initialize per-call variables
1561 : */
1562 9 : call_cntr = funcctx->call_cntr;
1563 9 : max_calls = funcctx->max_calls;
1564 :
1565 9 : results = (char **) funcctx->user_fctx;
1566 9 : attinmeta = funcctx->attinmeta;
1567 :
1568 9 : if (call_cntr < max_calls) /* do when there is more left to send */
1569 : {
1570 : char **values;
1571 : HeapTuple tuple;
1572 : Datum result;
1573 :
1574 6 : values = palloc_array(char *, 2);
1575 6 : values[0] = psprintf("%d", call_cntr + 1);
1576 6 : values[1] = results[call_cntr];
1577 :
1578 : /* build the tuple */
1579 6 : tuple = BuildTupleFromCStrings(attinmeta, values);
1580 :
1581 : /* make the tuple into a datum */
1582 6 : result = HeapTupleGetDatum(tuple);
1583 :
1584 6 : SRF_RETURN_NEXT(funcctx, result);
1585 : }
1586 : else
1587 : {
1588 : /* do when there is no more left */
1589 3 : SRF_RETURN_DONE(funcctx);
1590 : }
1591 : }
1592 :
1593 :
1594 : /*
1595 : * dblink_build_sql_insert
1596 : *
1597 : * Used to generate an SQL insert statement
1598 : * based on an existing tuple in a local relation.
1599 : * This is useful for selectively replicating data
1600 : * to another server via dblink.
1601 : *
1602 : * API:
1603 : * <relname> - name of local table of interest
1604 : * <pkattnums> - an int2vector of attnums which will be used
1605 : * to identify the local tuple of interest
1606 : * <pknumatts> - number of attnums in pkattnums
1607 : * <src_pkattvals_arry> - text array of key values which will be used
1608 : * to identify the local tuple of interest
1609 : * <tgt_pkattvals_arry> - text array of key values which will be used
1610 : * to build the string for execution remotely. These are substituted
1611 : * for their counterparts in src_pkattvals_arry
1612 : */
1613 4 : PG_FUNCTION_INFO_V1(dblink_build_sql_insert);
1614 : Datum
1615 6 : dblink_build_sql_insert(PG_FUNCTION_ARGS)
1616 : {
1617 6 : text *relname_text = PG_GETARG_TEXT_PP(0);
1618 6 : int2vector *pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
1619 6 : int32 pknumatts_arg = PG_GETARG_INT32(2);
1620 6 : ArrayType *src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
1621 6 : ArrayType *tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
1622 : Relation rel;
1623 : int *pkattnums;
1624 : int pknumatts;
1625 : char **src_pkattvals;
1626 : char **tgt_pkattvals;
1627 : int src_nitems;
1628 : int tgt_nitems;
1629 : char *sql;
1630 :
1631 : /*
1632 : * Open target relation.
1633 : */
1634 6 : rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);
1635 :
1636 : /*
1637 : * Process pkattnums argument.
1638 : */
1639 6 : validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
1640 : &pkattnums, &pknumatts);
1641 :
1642 : /*
1643 : * Source array is made up of key values that will be used to locate the
1644 : * tuple of interest from the local system.
1645 : */
1646 4 : src_pkattvals = get_text_array_contents(src_pkattvals_arry, &src_nitems);
1647 :
1648 : /*
1649 : * There should be one source array key value for each key attnum
1650 : */
1651 4 : if (src_nitems != pknumatts)
1652 0 : ereport(ERROR,
1653 : (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
1654 : errmsg("source key array length must match number of key attributes")));
1655 :
1656 : /*
1657 : * Target array is made up of key values that will be used to build the
1658 : * SQL string for use on the remote system.
1659 : */
1660 4 : tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);
1661 :
1662 : /*
1663 : * There should be one target array key value for each key attnum
1664 : */
1665 4 : if (tgt_nitems != pknumatts)
1666 0 : ereport(ERROR,
1667 : (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
1668 : errmsg("target key array length must match number of key attributes")));
1669 :
1670 : /*
1671 : * Prep work is finally done. Go get the SQL string.
1672 : */
1673 4 : sql = get_sql_insert(rel, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);
1674 :
1675 : /*
1676 : * Now we can close the relation.
1677 : */
1678 4 : relation_close(rel, AccessShareLock);
1679 :
1680 : /*
1681 : * And send it
1682 : */
1683 4 : PG_RETURN_TEXT_P(cstring_to_text(sql));
1684 : }
1685 :
1686 :
1687 : /*
1688 : * dblink_build_sql_delete
1689 : *
1690 : * Used to generate an SQL delete statement.
1691 : * This is useful for selectively replicating a
1692 : * delete to another server via dblink.
1693 : *
1694 : * API:
1695 : * <relname> - name of remote table of interest
1696 : * <pkattnums> - an int2vector of attnums which will be used
1697 : * to identify the remote tuple of interest
1698 : * <pknumatts> - number of attnums in pkattnums
1699 : * <tgt_pkattvals_arry> - text array of key values which will be used
1700 : * to build the string for execution remotely.
1701 : */
1702 4 : PG_FUNCTION_INFO_V1(dblink_build_sql_delete);
1703 : Datum
1704 6 : dblink_build_sql_delete(PG_FUNCTION_ARGS)
1705 : {
1706 6 : text *relname_text = PG_GETARG_TEXT_PP(0);
1707 6 : int2vector *pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
1708 6 : int32 pknumatts_arg = PG_GETARG_INT32(2);
1709 6 : ArrayType *tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
1710 : Relation rel;
1711 : int *pkattnums;
1712 : int pknumatts;
1713 : char **tgt_pkattvals;
1714 : int tgt_nitems;
1715 : char *sql;
1716 :
1717 : /*
1718 : * Open target relation.
1719 : */
1720 6 : rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);
1721 :
1722 : /*
1723 : * Process pkattnums argument.
1724 : */
1725 6 : validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
1726 : &pkattnums, &pknumatts);
1727 :
1728 : /*
1729 : * Target array is made up of key values that will be used to build the
1730 : * SQL string for use on the remote system.
1731 : */
1732 4 : tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);
1733 :
1734 : /*
1735 : * There should be one target array key value for each key attnum
1736 : */
1737 4 : if (tgt_nitems != pknumatts)
1738 0 : ereport(ERROR,
1739 : (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
1740 : errmsg("target key array length must match number of key attributes")));
1741 :
1742 : /*
1743 : * Prep work is finally done. Go get the SQL string.
1744 : */
1745 4 : sql = get_sql_delete(rel, pkattnums, pknumatts, tgt_pkattvals);
1746 :
1747 : /*
1748 : * Now we can close the relation.
1749 : */
1750 4 : relation_close(rel, AccessShareLock);
1751 :
1752 : /*
1753 : * And send it
1754 : */
1755 4 : PG_RETURN_TEXT_P(cstring_to_text(sql));
1756 : }
1757 :
1758 :
1759 : /*
1760 : * dblink_build_sql_update
1761 : *
1762 : * Used to generate an SQL update statement
1763 : * based on an existing tuple in a local relation.
1764 : * This is useful for selectively replicating data
1765 : * to another server via dblink.
1766 : *
1767 : * API:
1768 : * <relname> - name of local table of interest
1769 : * <pkattnums> - an int2vector of attnums which will be used
1770 : * to identify the local tuple of interest
1771 : * <pknumatts> - number of attnums in pkattnums
1772 : * <src_pkattvals_arry> - text array of key values which will be used
1773 : * to identify the local tuple of interest
1774 : * <tgt_pkattvals_arry> - text array of key values which will be used
1775 : * to build the string for execution remotely. These are substituted
1776 : * for their counterparts in src_pkattvals_arry
1777 : */
1778 4 : PG_FUNCTION_INFO_V1(dblink_build_sql_update);
1779 : Datum
1780 6 : dblink_build_sql_update(PG_FUNCTION_ARGS)
1781 : {
1782 6 : text *relname_text = PG_GETARG_TEXT_PP(0);
1783 6 : int2vector *pkattnums_arg = (int2vector *) PG_GETARG_POINTER(1);
1784 6 : int32 pknumatts_arg = PG_GETARG_INT32(2);
1785 6 : ArrayType *src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
1786 6 : ArrayType *tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
1787 : Relation rel;
1788 : int *pkattnums;
1789 : int pknumatts;
1790 : char **src_pkattvals;
1791 : char **tgt_pkattvals;
1792 : int src_nitems;
1793 : int tgt_nitems;
1794 : char *sql;
1795 :
1796 : /*
1797 : * Open target relation.
1798 : */
1799 6 : rel = get_rel_from_relname(relname_text, AccessShareLock, ACL_SELECT);
1800 :
1801 : /*
1802 : * Process pkattnums argument.
1803 : */
1804 6 : validate_pkattnums(rel, pkattnums_arg, pknumatts_arg,
1805 : &pkattnums, &pknumatts);
1806 :
1807 : /*
1808 : * Source array is made up of key values that will be used to locate the
1809 : * tuple of interest from the local system.
1810 : */
1811 4 : src_pkattvals = get_text_array_contents(src_pkattvals_arry, &src_nitems);
1812 :
1813 : /*
1814 : * There should be one source array key value for each key attnum
1815 : */
1816 4 : if (src_nitems != pknumatts)
1817 0 : ereport(ERROR,
1818 : (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
1819 : errmsg("source key array length must match number of key attributes")));
1820 :
1821 : /*
1822 : * Target array is made up of key values that will be used to build the
1823 : * SQL string for use on the remote system.
1824 : */
1825 4 : tgt_pkattvals = get_text_array_contents(tgt_pkattvals_arry, &tgt_nitems);
1826 :
1827 : /*
1828 : * There should be one target array key value for each key attnum
1829 : */
1830 4 : if (tgt_nitems != pknumatts)
1831 0 : ereport(ERROR,
1832 : (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
1833 : errmsg("target key array length must match number of key attributes")));
1834 :
1835 : /*
1836 : * Prep work is finally done. Go get the SQL string.
1837 : */
1838 4 : sql = get_sql_update(rel, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);
1839 :
1840 : /*
1841 : * Now we can close the relation.
1842 : */
1843 4 : relation_close(rel, AccessShareLock);
1844 :
1845 : /*
1846 : * And send it
1847 : */
1848 4 : PG_RETURN_TEXT_P(cstring_to_text(sql));
1849 : }
1850 :
1851 : /*
1852 : * dblink_current_query
1853 : * return the current query string
1854 : * to allow its use in (among other things)
1855 : * rewrite rules
1856 : */
1857 2 : PG_FUNCTION_INFO_V1(dblink_current_query);
1858 : Datum
1859 0 : dblink_current_query(PG_FUNCTION_ARGS)
1860 : {
1861 : /* This is now just an alias for the built-in function current_query() */
1862 0 : PG_RETURN_DATUM(current_query(fcinfo));
1863 : }
1864 :
1865 : /*
1866 : * Retrieve async notifications for a connection.
1867 : *
1868 : * Returns a setof record of notifications, or an empty set if none received.
1869 : * Can optionally take a named connection as parameter, but uses the unnamed
1870 : * connection per default.
1871 : *
1872 : */
1873 : #define DBLINK_NOTIFY_COLS 3
1874 :
1875 5 : PG_FUNCTION_INFO_V1(dblink_get_notify);
1876 : Datum
1877 2 : dblink_get_notify(PG_FUNCTION_ARGS)
1878 : {
1879 : PGconn *conn;
1880 : PGnotify *notify;
1881 2 : ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
1882 :
1883 2 : dblink_init();
1884 2 : if (PG_NARGS() == 1)
1885 0 : conn = dblink_get_named_conn(text_to_cstring(PG_GETARG_TEXT_PP(0)));
1886 : else
1887 2 : conn = pconn->conn;
1888 :
1889 2 : InitMaterializedSRF(fcinfo, 0);
1890 :
1891 2 : PQconsumeInput(conn);
1892 4 : while ((notify = PQnotifies(conn)) != NULL)
1893 : {
1894 : Datum values[DBLINK_NOTIFY_COLS];
1895 : bool nulls[DBLINK_NOTIFY_COLS];
1896 :
1897 2 : memset(values, 0, sizeof(values));
1898 2 : memset(nulls, 0, sizeof(nulls));
1899 :
1900 2 : if (notify->relname != NULL)
1901 2 : values[0] = CStringGetTextDatum(notify->relname);
1902 : else
1903 0 : nulls[0] = true;
1904 :
1905 2 : values[1] = Int32GetDatum(notify->be_pid);
1906 :
1907 2 : if (notify->extra != NULL)
1908 2 : values[2] = CStringGetTextDatum(notify->extra);
1909 : else
1910 0 : nulls[2] = true;
1911 :
1912 2 : tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
1913 :
1914 2 : PQfreemem(notify);
1915 2 : PQconsumeInput(conn);
1916 : }
1917 :
1918 2 : return (Datum) 0;
1919 : }
1920 :
1921 : /*
1922 : * Validate the options given to a dblink foreign server or user mapping.
1923 : * Raise an error if any option is invalid.
1924 : *
1925 : * We just check the names of options here, so semantic errors in options,
1926 : * such as invalid numeric format, will be detected at the attempt to connect.
1927 : */
1928 14 : PG_FUNCTION_INFO_V1(dblink_fdw_validator);
1929 : Datum
1930 19 : dblink_fdw_validator(PG_FUNCTION_ARGS)
1931 : {
1932 19 : List *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
1933 19 : Oid context = PG_GETARG_OID(1);
1934 : ListCell *cell;
1935 :
1936 : static const PQconninfoOption *options = NULL;
1937 :
1938 : /*
1939 : * Get list of valid libpq options.
1940 : *
1941 : * To avoid unnecessary work, we get the list once and use it throughout
1942 : * the lifetime of this backend process. We don't need to care about
1943 : * memory context issues, because PQconndefaults allocates with malloc.
1944 : */
1945 19 : if (!options)
1946 : {
1947 12 : options = PQconndefaults();
1948 12 : if (!options) /* assume reason for failure is OOM */
1949 0 : ereport(ERROR,
1950 : (errcode(ERRCODE_FDW_OUT_OF_MEMORY),
1951 : errmsg("out of memory"),
1952 : errdetail("Could not get libpq's default connection options.")));
1953 : }
1954 :
1955 : /* Validate each supplied option. */
1956 50 : foreach(cell, options_list)
1957 : {
1958 39 : DefElem *def = (DefElem *) lfirst(cell);
1959 :
1960 39 : if (!is_valid_dblink_fdw_option(options, def->defname, context))
1961 : {
1962 : /*
1963 : * Unknown option, or invalid option for the context specified, so
1964 : * complain about it. Provide a hint with a valid option that
1965 : * looks similar, if there is one.
1966 : */
1967 : const PQconninfoOption *opt;
1968 : const char *closest_match;
1969 : ClosestMatchState match_state;
1970 8 : bool has_valid_options = false;
1971 :
1972 8 : initClosestMatch(&match_state, def->defname, 4);
1973 416 : for (opt = options; opt->keyword; opt++)
1974 : {
1975 408 : if (is_valid_dblink_option(options, opt->keyword, context))
1976 : {
1977 93 : has_valid_options = true;
1978 93 : updateClosestMatch(&match_state, opt->keyword);
1979 : }
1980 : }
1981 :
1982 8 : closest_match = getClosestMatch(&match_state);
1983 8 : ereport(ERROR,
1984 : (errcode(ERRCODE_FDW_OPTION_NAME_NOT_FOUND),
1985 : errmsg("invalid option \"%s\"", def->defname),
1986 : has_valid_options ? closest_match ?
1987 : errhint("Perhaps you meant the option \"%s\".",
1988 : closest_match) : 0 :
1989 : errhint("There are no valid options in this context.")));
1990 : }
1991 : }
1992 :
1993 11 : PG_RETURN_VOID();
1994 : }
1995 :
1996 :
1997 : /*************************************************************
1998 : * internal functions
1999 : */
2000 :
2001 :
2002 : /*
2003 : * get_pkey_attnames
2004 : *
2005 : * Get the primary key attnames for the given relation.
2006 : * Return NULL, and set indnkeyatts = 0, if no primary key exists.
2007 : */
2008 : static char **
2009 3 : get_pkey_attnames(Relation rel, int16 *indnkeyatts)
2010 : {
2011 : Relation indexRelation;
2012 : ScanKeyData skey;
2013 : SysScanDesc scan;
2014 : HeapTuple indexTuple;
2015 : int i;
2016 3 : char **result = NULL;
2017 : TupleDesc tupdesc;
2018 :
2019 : /* initialize indnkeyatts to 0 in case no primary key exists */
2020 3 : *indnkeyatts = 0;
2021 :
2022 3 : tupdesc = rel->rd_att;
2023 :
2024 : /* Prepare to scan pg_index for entries having indrelid = this rel. */
2025 3 : indexRelation = table_open(IndexRelationId, AccessShareLock);
2026 3 : ScanKeyInit(&skey,
2027 : Anum_pg_index_indrelid,
2028 : BTEqualStrategyNumber, F_OIDEQ,
2029 : ObjectIdGetDatum(RelationGetRelid(rel)));
2030 :
2031 3 : scan = systable_beginscan(indexRelation, IndexIndrelidIndexId, true,
2032 : NULL, 1, &skey);
2033 :
2034 3 : while (HeapTupleIsValid(indexTuple = systable_getnext(scan)))
2035 : {
2036 3 : Form_pg_index index = (Form_pg_index) GETSTRUCT(indexTuple);
2037 :
2038 : /* we're only interested if it is the primary key */
2039 3 : if (index->indisprimary)
2040 : {
2041 3 : *indnkeyatts = index->indnkeyatts;
2042 3 : if (*indnkeyatts > 0)
2043 : {
2044 3 : result = palloc_array(char *, *indnkeyatts);
2045 :
2046 9 : for (i = 0; i < *indnkeyatts; i++)
2047 6 : result[i] = SPI_fname(tupdesc, index->indkey.values[i]);
2048 : }
2049 3 : break;
2050 : }
2051 : }
2052 :
2053 3 : systable_endscan(scan);
2054 3 : table_close(indexRelation, AccessShareLock);
2055 :
2056 3 : return result;
2057 : }
2058 :
2059 : /*
2060 : * Deconstruct a text[] into C-strings (note any NULL elements will be
2061 : * returned as NULL pointers)
2062 : */
2063 : static char **
2064 20 : get_text_array_contents(ArrayType *array, int *numitems)
2065 : {
2066 20 : int ndim = ARR_NDIM(array);
2067 20 : int *dims = ARR_DIMS(array);
2068 : int nitems;
2069 : int16 typlen;
2070 : bool typbyval;
2071 : char typalign;
2072 : uint8 typalignby;
2073 : char **values;
2074 : char *ptr;
2075 : bits8 *bitmap;
2076 : int bitmask;
2077 : int i;
2078 :
2079 : Assert(ARR_ELEMTYPE(array) == TEXTOID);
2080 :
2081 20 : *numitems = nitems = ArrayGetNItems(ndim, dims);
2082 :
2083 20 : get_typlenbyvalalign(ARR_ELEMTYPE(array),
2084 : &typlen, &typbyval, &typalign);
2085 20 : typalignby = typalign_to_alignby(typalign);
2086 :
2087 20 : values = palloc_array(char *, nitems);
2088 :
2089 20 : ptr = ARR_DATA_PTR(array);
2090 20 : bitmap = ARR_NULLBITMAP(array);
2091 20 : bitmask = 1;
2092 :
2093 55 : for (i = 0; i < nitems; i++)
2094 : {
2095 35 : if (bitmap && (*bitmap & bitmask) == 0)
2096 : {
2097 0 : values[i] = NULL;
2098 : }
2099 : else
2100 : {
2101 35 : values[i] = TextDatumGetCString(PointerGetDatum(ptr));
2102 35 : ptr = att_addlength_pointer(ptr, typlen, ptr);
2103 35 : ptr = (char *) att_nominal_alignby(ptr, typalignby);
2104 : }
2105 :
2106 : /* advance bitmap pointer if any */
2107 35 : if (bitmap)
2108 : {
2109 0 : bitmask <<= 1;
2110 0 : if (bitmask == 0x100)
2111 : {
2112 0 : bitmap++;
2113 0 : bitmask = 1;
2114 : }
2115 : }
2116 : }
2117 :
2118 20 : return values;
2119 : }
2120 :
2121 : static char *
2122 4 : get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
2123 : {
2124 : char *relname;
2125 : HeapTuple tuple;
2126 : TupleDesc tupdesc;
2127 : int natts;
2128 : StringInfoData buf;
2129 : char *val;
2130 : int key;
2131 : int i;
2132 : bool needComma;
2133 :
2134 4 : initStringInfo(&buf);
2135 :
2136 : /* get relation name including any needed schema prefix and quoting */
2137 4 : relname = generate_relation_name(rel);
2138 :
2139 4 : tupdesc = rel->rd_att;
2140 4 : natts = tupdesc->natts;
2141 :
2142 4 : tuple = get_tuple_of_interest(rel, pkattnums, pknumatts, src_pkattvals);
2143 4 : if (!tuple)
2144 0 : ereport(ERROR,
2145 : (errcode(ERRCODE_CARDINALITY_VIOLATION),
2146 : errmsg("source row not found")));
2147 :
2148 4 : appendStringInfo(&buf, "INSERT INTO %s(", relname);
2149 :
2150 4 : needComma = false;
2151 19 : for (i = 0; i < natts; i++)
2152 : {
2153 15 : Form_pg_attribute att = TupleDescAttr(tupdesc, i);
2154 :
2155 15 : if (att->attisdropped)
2156 2 : continue;
2157 :
2158 13 : if (needComma)
2159 9 : appendStringInfoChar(&buf, ',');
2160 :
2161 13 : appendStringInfoString(&buf,
2162 13 : quote_ident_cstr(NameStr(att->attname)));
2163 13 : needComma = true;
2164 : }
2165 :
2166 4 : appendStringInfoString(&buf, ") VALUES(");
2167 :
2168 : /*
2169 : * Note: i is physical column number (counting from 0).
2170 : */
2171 4 : needComma = false;
2172 19 : for (i = 0; i < natts; i++)
2173 : {
2174 15 : if (TupleDescAttr(tupdesc, i)->attisdropped)
2175 2 : continue;
2176 :
2177 13 : if (needComma)
2178 9 : appendStringInfoChar(&buf, ',');
2179 :
2180 13 : key = get_attnum_pk_pos(pkattnums, pknumatts, i);
2181 :
2182 13 : if (key >= 0)
2183 7 : val = tgt_pkattvals[key] ? pstrdup(tgt_pkattvals[key]) : NULL;
2184 : else
2185 6 : val = SPI_getvalue(tuple, tupdesc, i + 1);
2186 :
2187 13 : if (val != NULL)
2188 : {
2189 13 : appendStringInfoString(&buf, quote_literal_cstr(val));
2190 13 : pfree(val);
2191 : }
2192 : else
2193 0 : appendStringInfoString(&buf, "NULL");
2194 13 : needComma = true;
2195 : }
2196 4 : appendStringInfoChar(&buf, ')');
2197 :
2198 4 : return buf.data;
2199 : }
2200 :
2201 : static char *
2202 4 : get_sql_delete(Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals)
2203 : {
2204 : char *relname;
2205 : TupleDesc tupdesc;
2206 : StringInfoData buf;
2207 : int i;
2208 :
2209 4 : initStringInfo(&buf);
2210 :
2211 : /* get relation name including any needed schema prefix and quoting */
2212 4 : relname = generate_relation_name(rel);
2213 :
2214 4 : tupdesc = rel->rd_att;
2215 :
2216 4 : appendStringInfo(&buf, "DELETE FROM %s WHERE ", relname);
2217 11 : for (i = 0; i < pknumatts; i++)
2218 : {
2219 7 : int pkattnum = pkattnums[i];
2220 7 : Form_pg_attribute attr = TupleDescAttr(tupdesc, pkattnum);
2221 :
2222 7 : if (i > 0)
2223 3 : appendStringInfoString(&buf, " AND ");
2224 :
2225 7 : appendStringInfoString(&buf,
2226 7 : quote_ident_cstr(NameStr(attr->attname)));
2227 :
2228 7 : if (tgt_pkattvals[i] != NULL)
2229 7 : appendStringInfo(&buf, " = %s",
2230 7 : quote_literal_cstr(tgt_pkattvals[i]));
2231 : else
2232 0 : appendStringInfoString(&buf, " IS NULL");
2233 : }
2234 :
2235 4 : return buf.data;
2236 : }
2237 :
2238 : static char *
2239 4 : get_sql_update(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals)
2240 : {
2241 : char *relname;
2242 : HeapTuple tuple;
2243 : TupleDesc tupdesc;
2244 : int natts;
2245 : StringInfoData buf;
2246 : char *val;
2247 : int key;
2248 : int i;
2249 : bool needComma;
2250 :
2251 4 : initStringInfo(&buf);
2252 :
2253 : /* get relation name including any needed schema prefix and quoting */
2254 4 : relname = generate_relation_name(rel);
2255 :
2256 4 : tupdesc = rel->rd_att;
2257 4 : natts = tupdesc->natts;
2258 :
2259 4 : tuple = get_tuple_of_interest(rel, pkattnums, pknumatts, src_pkattvals);
2260 4 : if (!tuple)
2261 0 : ereport(ERROR,
2262 : (errcode(ERRCODE_CARDINALITY_VIOLATION),
2263 : errmsg("source row not found")));
2264 :
2265 4 : appendStringInfo(&buf, "UPDATE %s SET ", relname);
2266 :
2267 : /*
2268 : * Note: i is physical column number (counting from 0).
2269 : */
2270 4 : needComma = false;
2271 19 : for (i = 0; i < natts; i++)
2272 : {
2273 15 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
2274 :
2275 15 : if (attr->attisdropped)
2276 2 : continue;
2277 :
2278 13 : if (needComma)
2279 9 : appendStringInfoString(&buf, ", ");
2280 :
2281 13 : appendStringInfo(&buf, "%s = ",
2282 13 : quote_ident_cstr(NameStr(attr->attname)));
2283 :
2284 13 : key = get_attnum_pk_pos(pkattnums, pknumatts, i);
2285 :
2286 13 : if (key >= 0)
2287 7 : val = tgt_pkattvals[key] ? pstrdup(tgt_pkattvals[key]) : NULL;
2288 : else
2289 6 : val = SPI_getvalue(tuple, tupdesc, i + 1);
2290 :
2291 13 : if (val != NULL)
2292 : {
2293 13 : appendStringInfoString(&buf, quote_literal_cstr(val));
2294 13 : pfree(val);
2295 : }
2296 : else
2297 0 : appendStringInfoString(&buf, "NULL");
2298 13 : needComma = true;
2299 : }
2300 :
2301 4 : appendStringInfoString(&buf, " WHERE ");
2302 :
2303 11 : for (i = 0; i < pknumatts; i++)
2304 : {
2305 7 : int pkattnum = pkattnums[i];
2306 7 : Form_pg_attribute attr = TupleDescAttr(tupdesc, pkattnum);
2307 :
2308 7 : if (i > 0)
2309 3 : appendStringInfoString(&buf, " AND ");
2310 :
2311 7 : appendStringInfoString(&buf,
2312 7 : quote_ident_cstr(NameStr(attr->attname)));
2313 :
2314 7 : val = tgt_pkattvals[i];
2315 :
2316 7 : if (val != NULL)
2317 7 : appendStringInfo(&buf, " = %s", quote_literal_cstr(val));
2318 : else
2319 0 : appendStringInfoString(&buf, " IS NULL");
2320 : }
2321 :
2322 4 : return buf.data;
2323 : }
2324 :
2325 : /*
2326 : * Return a properly quoted identifier.
2327 : * Uses quote_ident in quote.c
2328 : */
2329 : static char *
2330 80 : quote_ident_cstr(char *rawstr)
2331 : {
2332 : text *rawstr_text;
2333 : text *result_text;
2334 : char *result;
2335 :
2336 80 : rawstr_text = cstring_to_text(rawstr);
2337 80 : result_text = DatumGetTextPP(DirectFunctionCall1(quote_ident,
2338 : PointerGetDatum(rawstr_text)));
2339 80 : result = text_to_cstring(result_text);
2340 :
2341 80 : return result;
2342 : }
2343 :
2344 : static int
2345 26 : get_attnum_pk_pos(int *pkattnums, int pknumatts, int key)
2346 : {
2347 : int i;
2348 :
2349 : /*
2350 : * Not likely a long list anyway, so just scan for the value
2351 : */
2352 50 : for (i = 0; i < pknumatts; i++)
2353 38 : if (key == pkattnums[i])
2354 14 : return i;
2355 :
2356 12 : return -1;
2357 : }
2358 :
2359 : static HeapTuple
2360 8 : get_tuple_of_interest(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals)
2361 : {
2362 : char *relname;
2363 : TupleDesc tupdesc;
2364 : int natts;
2365 : StringInfoData buf;
2366 : int ret;
2367 : HeapTuple tuple;
2368 : int i;
2369 :
2370 : /*
2371 : * Connect to SPI manager
2372 : */
2373 8 : SPI_connect();
2374 :
2375 8 : initStringInfo(&buf);
2376 :
2377 : /* get relation name including any needed schema prefix and quoting */
2378 8 : relname = generate_relation_name(rel);
2379 :
2380 8 : tupdesc = rel->rd_att;
2381 8 : natts = tupdesc->natts;
2382 :
2383 : /*
2384 : * Build sql statement to look up tuple of interest, ie, the one matching
2385 : * src_pkattvals. We used to use "SELECT *" here, but it's simpler to
2386 : * generate a result tuple that matches the table's physical structure,
2387 : * with NULLs for any dropped columns. Otherwise we have to deal with two
2388 : * different tupdescs and everything's very confusing.
2389 : */
2390 8 : appendStringInfoString(&buf, "SELECT ");
2391 :
2392 38 : for (i = 0; i < natts; i++)
2393 : {
2394 30 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
2395 :
2396 30 : if (i > 0)
2397 22 : appendStringInfoString(&buf, ", ");
2398 :
2399 30 : if (attr->attisdropped)
2400 4 : appendStringInfoString(&buf, "NULL");
2401 : else
2402 26 : appendStringInfoString(&buf,
2403 26 : quote_ident_cstr(NameStr(attr->attname)));
2404 : }
2405 :
2406 8 : appendStringInfo(&buf, " FROM %s WHERE ", relname);
2407 :
2408 22 : for (i = 0; i < pknumatts; i++)
2409 : {
2410 14 : int pkattnum = pkattnums[i];
2411 14 : Form_pg_attribute attr = TupleDescAttr(tupdesc, pkattnum);
2412 :
2413 14 : if (i > 0)
2414 6 : appendStringInfoString(&buf, " AND ");
2415 :
2416 14 : appendStringInfoString(&buf,
2417 14 : quote_ident_cstr(NameStr(attr->attname)));
2418 :
2419 14 : if (src_pkattvals[i] != NULL)
2420 14 : appendStringInfo(&buf, " = %s",
2421 14 : quote_literal_cstr(src_pkattvals[i]));
2422 : else
2423 0 : appendStringInfoString(&buf, " IS NULL");
2424 : }
2425 :
2426 : /*
2427 : * Retrieve the desired tuple
2428 : */
2429 8 : ret = SPI_exec(buf.data, 0);
2430 8 : pfree(buf.data);
2431 :
2432 : /*
2433 : * Only allow one qualifying tuple
2434 : */
2435 8 : if ((ret == SPI_OK_SELECT) && (SPI_processed > 1))
2436 0 : ereport(ERROR,
2437 : (errcode(ERRCODE_CARDINALITY_VIOLATION),
2438 : errmsg("source criteria matched more than one record")));
2439 :
2440 8 : else if (ret == SPI_OK_SELECT && SPI_processed == 1)
2441 : {
2442 8 : SPITupleTable *tuptable = SPI_tuptable;
2443 :
2444 8 : tuple = SPI_copytuple(tuptable->vals[0]);
2445 8 : SPI_finish();
2446 :
2447 8 : return tuple;
2448 : }
2449 : else
2450 : {
2451 : /*
2452 : * no qualifying tuples
2453 : */
2454 0 : SPI_finish();
2455 :
2456 0 : return NULL;
2457 : }
2458 :
2459 : /*
2460 : * never reached, but keep compiler quiet
2461 : */
2462 : return NULL;
2463 : }
2464 :
2465 : static void
2466 21 : RangeVarCallbackForDblink(const RangeVar *relation,
2467 : Oid relId, Oid oldRelId, void *arg)
2468 : {
2469 : AclResult aclresult;
2470 :
2471 21 : if (!OidIsValid(relId))
2472 0 : return;
2473 :
2474 21 : aclresult = pg_class_aclcheck(relId, GetUserId(), *((AclMode *) arg));
2475 21 : if (aclresult != ACLCHECK_OK)
2476 0 : aclcheck_error(aclresult, get_relkind_objtype(get_rel_relkind(relId)),
2477 0 : relation->relname);
2478 : }
2479 :
2480 : /*
2481 : * Open the relation named by relname_text, acquire specified type of lock,
2482 : * verify we have specified permissions.
2483 : * Caller must close rel when done with it.
2484 : */
2485 : static Relation
2486 21 : get_rel_from_relname(text *relname_text, LOCKMODE lockmode, AclMode aclmode)
2487 : {
2488 : RangeVar *relvar;
2489 : Oid relid;
2490 :
2491 21 : relvar = makeRangeVarFromNameList(textToQualifiedNameList(relname_text));
2492 21 : relid = RangeVarGetRelidExtended(relvar, lockmode, 0,
2493 : RangeVarCallbackForDblink, &aclmode);
2494 :
2495 21 : return table_open(relid, NoLock);
2496 : }
2497 :
2498 : /*
2499 : * generate_relation_name - copied from ruleutils.c
2500 : * Compute the name to display for a relation
2501 : *
2502 : * The result includes all necessary quoting and schema-prefixing.
2503 : */
2504 : static char *
2505 20 : generate_relation_name(Relation rel)
2506 : {
2507 : char *nspname;
2508 : char *result;
2509 :
2510 : /* Qualify the name if not visible in search path */
2511 20 : if (RelationIsVisible(RelationGetRelid(rel)))
2512 15 : nspname = NULL;
2513 : else
2514 5 : nspname = get_namespace_name(rel->rd_rel->relnamespace);
2515 :
2516 20 : result = quote_qualified_identifier(nspname, RelationGetRelationName(rel));
2517 :
2518 20 : return result;
2519 : }
2520 :
2521 :
2522 : static remoteConn *
2523 78 : getConnectionByName(const char *name)
2524 : {
2525 : remoteConnHashEnt *hentry;
2526 : char *key;
2527 :
2528 78 : if (!remoteConnHash)
2529 5 : remoteConnHash = createConnHash();
2530 :
2531 78 : key = pstrdup(name);
2532 78 : truncate_identifier(key, strlen(key), false);
2533 78 : hentry = (remoteConnHashEnt *) hash_search(remoteConnHash,
2534 : key, HASH_FIND, NULL);
2535 :
2536 78 : if (hentry && hentry->rconn.conn != NULL)
2537 68 : return &hentry->rconn;
2538 :
2539 10 : return NULL;
2540 : }
2541 :
2542 : static HTAB *
2543 6 : createConnHash(void)
2544 : {
2545 : HASHCTL ctl;
2546 :
2547 6 : ctl.keysize = NAMEDATALEN;
2548 6 : ctl.entrysize = sizeof(remoteConnHashEnt);
2549 :
2550 6 : return hash_create("Remote Con hash", NUMCONN, &ctl,
2551 : HASH_ELEM | HASH_STRINGS);
2552 : }
2553 :
2554 : static remoteConn *
2555 10 : createNewConnection(const char *name)
2556 : {
2557 : remoteConnHashEnt *hentry;
2558 : bool found;
2559 : char *key;
2560 :
2561 10 : if (!remoteConnHash)
2562 1 : remoteConnHash = createConnHash();
2563 :
2564 10 : key = pstrdup(name);
2565 10 : truncate_identifier(key, strlen(key), true);
2566 10 : hentry = (remoteConnHashEnt *) hash_search(remoteConnHash, key,
2567 : HASH_ENTER, &found);
2568 :
2569 10 : if (found && hentry->rconn.conn != NULL)
2570 1 : ereport(ERROR,
2571 : (errcode(ERRCODE_DUPLICATE_OBJECT),
2572 : errmsg("duplicate connection name")));
2573 :
2574 : /* New, or reusable, so initialize the rconn struct to zeroes */
2575 9 : memset(&hentry->rconn, 0, sizeof(remoteConn));
2576 :
2577 9 : return &hentry->rconn;
2578 : }
2579 :
2580 : static void
2581 8 : deleteConnection(const char *name)
2582 : {
2583 : remoteConnHashEnt *hentry;
2584 : bool found;
2585 : char *key;
2586 :
2587 8 : if (!remoteConnHash)
2588 0 : remoteConnHash = createConnHash();
2589 :
2590 8 : key = pstrdup(name);
2591 8 : truncate_identifier(key, strlen(key), false);
2592 8 : hentry = (remoteConnHashEnt *) hash_search(remoteConnHash,
2593 : key, HASH_REMOVE, &found);
2594 :
2595 8 : if (!hentry)
2596 0 : ereport(ERROR,
2597 : (errcode(ERRCODE_UNDEFINED_OBJECT),
2598 : errmsg("undefined connection name")));
2599 8 : }
2600 :
2601 : /*
2602 : * Ensure that require_auth and SCRAM keys are correctly set on connstr.
2603 : * SCRAM keys used to pass-through are coming from the initial connection
2604 : * from the client with the server.
2605 : *
2606 : * All required SCRAM options are set by dblink, so we just need to ensure
2607 : * that these options are not overwritten by the user.
2608 : *
2609 : * See appendSCRAMKeysInfo and its usage for more.
2610 : */
2611 : bool
2612 5 : dblink_connstr_has_required_scram_options(const char *connstr)
2613 : {
2614 : PQconninfoOption *options;
2615 5 : bool has_scram_server_key = false;
2616 5 : bool has_scram_client_key = false;
2617 5 : bool has_require_auth = false;
2618 5 : bool has_scram_keys = false;
2619 :
2620 5 : options = PQconninfoParse(connstr, NULL);
2621 5 : if (options)
2622 : {
2623 : /*
2624 : * Continue iterating even if we found the keys that we need to
2625 : * validate to make sure that there is no other declaration of these
2626 : * keys that can overwrite the first.
2627 : */
2628 260 : for (PQconninfoOption *option = options; option->keyword != NULL; option++)
2629 : {
2630 255 : if (strcmp(option->keyword, "require_auth") == 0)
2631 : {
2632 5 : if (option->val != NULL && strcmp(option->val, "scram-sha-256") == 0)
2633 4 : has_require_auth = true;
2634 : else
2635 1 : has_require_auth = false;
2636 : }
2637 :
2638 255 : if (strcmp(option->keyword, "scram_client_key") == 0)
2639 : {
2640 5 : if (option->val != NULL && option->val[0] != '\0')
2641 5 : has_scram_client_key = true;
2642 : else
2643 0 : has_scram_client_key = false;
2644 : }
2645 :
2646 255 : if (strcmp(option->keyword, "scram_server_key") == 0)
2647 : {
2648 5 : if (option->val != NULL && option->val[0] != '\0')
2649 5 : has_scram_server_key = true;
2650 : else
2651 0 : has_scram_server_key = false;
2652 : }
2653 : }
2654 5 : PQconninfoFree(options);
2655 : }
2656 :
2657 5 : has_scram_keys = has_scram_client_key && has_scram_server_key && MyProcPort != NULL && MyProcPort->has_scram_keys;
2658 :
2659 5 : return (has_scram_keys && has_require_auth);
2660 : }
2661 :
2662 : /*
2663 : * We need to make sure that the connection made used credentials
2664 : * which were provided by the user, so check what credentials were
2665 : * used to connect and then make sure that they came from the user.
2666 : *
2667 : * On failure, we close "conn" and also delete the hashtable entry
2668 : * identified by "connname" (if that's not NULL).
2669 : */
2670 : static void
2671 20 : dblink_security_check(PGconn *conn, const char *connname, const char *connstr)
2672 : {
2673 : /* Superuser bypasses security check */
2674 20 : if (superuser())
2675 18 : return;
2676 :
2677 : /* If password was used to connect, make sure it was one provided */
2678 2 : if (PQconnectionUsedPassword(conn) && dblink_connstr_has_pw(connstr))
2679 0 : return;
2680 :
2681 : /*
2682 : * Password was not used to connect, check if SCRAM pass-through is in
2683 : * use.
2684 : *
2685 : * If dblink_connstr_has_required_scram_options is true we assume that
2686 : * UseScramPassthrough is also true because the required SCRAM keys are
2687 : * only added if UseScramPassthrough is set, and the user is not allowed
2688 : * to add the SCRAM keys on fdw and user mapping options.
2689 : */
2690 2 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && dblink_connstr_has_required_scram_options(connstr))
2691 2 : return;
2692 :
2693 : #ifdef ENABLE_GSS
2694 : /* If GSSAPI creds used to connect, make sure it was one delegated */
2695 : if (PQconnectionUsedGSSAPI(conn) && be_gssapi_get_delegation(MyProcPort))
2696 : return;
2697 : #endif
2698 :
2699 : /* Otherwise, fail out */
2700 0 : libpqsrv_disconnect(conn);
2701 0 : if (connname)
2702 0 : deleteConnection(connname);
2703 :
2704 0 : ereport(ERROR,
2705 : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
2706 : errmsg("password or GSSAPI delegated credentials required"),
2707 : errdetail("Non-superusers may only connect using credentials they provide, eg: password in connection string or delegated GSSAPI credentials"),
2708 : errhint("Ensure provided credentials match target server's authentication method.")));
2709 : }
2710 :
2711 : /*
2712 : * Function to check if the connection string includes an explicit
2713 : * password, needed to ensure that non-superuser password-based auth
2714 : * is using a provided password and not one picked up from the
2715 : * environment.
2716 : */
2717 : static bool
2718 6 : dblink_connstr_has_pw(const char *connstr)
2719 : {
2720 : PQconninfoOption *options;
2721 : PQconninfoOption *option;
2722 6 : bool connstr_gives_password = false;
2723 :
2724 6 : options = PQconninfoParse(connstr, NULL);
2725 6 : if (options)
2726 : {
2727 312 : for (option = options; option->keyword != NULL; option++)
2728 : {
2729 306 : if (strcmp(option->keyword, "password") == 0)
2730 : {
2731 6 : if (option->val != NULL && option->val[0] != '\0')
2732 : {
2733 0 : connstr_gives_password = true;
2734 0 : break;
2735 : }
2736 : }
2737 : }
2738 6 : PQconninfoFree(options);
2739 : }
2740 :
2741 6 : return connstr_gives_password;
2742 : }
2743 :
2744 : /*
2745 : * For non-superusers, insist that the connstr specify a password, except if
2746 : * GSSAPI credentials have been delegated (and we check that they are used for
2747 : * the connection in dblink_security_check later) or if SCRAM pass-through is
2748 : * being used. This prevents a password or GSSAPI credentials from being
2749 : * picked up from .pgpass, a service file, the environment, etc. We don't want
2750 : * the postgres user's passwords or Kerberos credentials to be accessible to
2751 : * non-superusers. In case of SCRAM pass-through insist that the connstr
2752 : * has the required SCRAM pass-through options.
2753 : */
2754 : static void
2755 25 : dblink_connstr_check(const char *connstr)
2756 : {
2757 25 : if (superuser())
2758 21 : return;
2759 :
2760 4 : if (dblink_connstr_has_pw(connstr))
2761 0 : return;
2762 :
2763 4 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && dblink_connstr_has_required_scram_options(connstr))
2764 2 : return;
2765 :
2766 : #ifdef ENABLE_GSS
2767 : if (be_gssapi_get_delegation(MyProcPort))
2768 : return;
2769 : #endif
2770 :
2771 2 : ereport(ERROR,
2772 : (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
2773 : errmsg("password or GSSAPI delegated credentials required"),
2774 : errdetail("Non-superusers must provide a password in the connection string or send delegated GSSAPI credentials.")));
2775 : }
2776 :
2777 : /*
2778 : * Report an error received from the remote server
2779 : *
2780 : * res: the received error result
2781 : * fail: true for ERROR ereport, false for NOTICE
2782 : * fmt and following args: sprintf-style format and values for errcontext;
2783 : * the resulting string should be worded like "while <some action>"
2784 : *
2785 : * If "res" is not NULL, it'll be PQclear'ed here (unless we throw error,
2786 : * in which case memory context cleanup will clear it eventually).
2787 : */
2788 : static void
2789 12 : dblink_res_error(PGconn *conn, const char *conname, PGresult *res,
2790 : bool fail, const char *fmt,...)
2791 : {
2792 : int level;
2793 12 : char *pg_diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
2794 12 : char *message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY);
2795 12 : char *message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL);
2796 12 : char *message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT);
2797 12 : char *message_context = PQresultErrorField(res, PG_DIAG_CONTEXT);
2798 : int sqlstate;
2799 : va_list ap;
2800 : char dblink_context_msg[512];
2801 :
2802 12 : if (fail)
2803 3 : level = ERROR;
2804 : else
2805 9 : level = NOTICE;
2806 :
2807 12 : if (pg_diag_sqlstate)
2808 12 : sqlstate = MAKE_SQLSTATE(pg_diag_sqlstate[0],
2809 : pg_diag_sqlstate[1],
2810 : pg_diag_sqlstate[2],
2811 : pg_diag_sqlstate[3],
2812 : pg_diag_sqlstate[4]);
2813 : else
2814 0 : sqlstate = ERRCODE_CONNECTION_FAILURE;
2815 :
2816 : /*
2817 : * If we don't get a message from the PGresult, try the PGconn. This is
2818 : * needed because for connection-level failures, PQgetResult may just
2819 : * return NULL, not a PGresult at all.
2820 : */
2821 12 : if (message_primary == NULL)
2822 0 : message_primary = pchomp(PQerrorMessage(conn));
2823 :
2824 : /*
2825 : * Format the basic errcontext string. Below, we'll add on something
2826 : * about the connection name. That's a violation of the translatability
2827 : * guidelines about constructing error messages out of parts, but since
2828 : * there's no translation support for dblink, there's no need to worry
2829 : * about that (yet).
2830 : */
2831 12 : va_start(ap, fmt);
2832 12 : vsnprintf(dblink_context_msg, sizeof(dblink_context_msg), fmt, ap);
2833 12 : va_end(ap);
2834 :
2835 12 : ereport(level,
2836 : (errcode(sqlstate),
2837 : (message_primary != NULL && message_primary[0] != '\0') ?
2838 : errmsg_internal("%s", message_primary) :
2839 : errmsg("could not obtain message string for remote error"),
2840 : message_detail ? errdetail_internal("%s", message_detail) : 0,
2841 : message_hint ? errhint("%s", message_hint) : 0,
2842 : message_context ? (errcontext("%s", message_context)) : 0,
2843 : conname ?
2844 : (errcontext("%s on dblink connection named \"%s\"",
2845 : dblink_context_msg, conname)) :
2846 : (errcontext("%s on unnamed dblink connection",
2847 : dblink_context_msg))));
2848 9 : PQclear(res);
2849 9 : }
2850 :
2851 : /*
2852 : * Obtain connection string for a foreign server
2853 : */
2854 : static char *
2855 25 : get_connect_string(const char *servername)
2856 : {
2857 25 : ForeignServer *foreign_server = NULL;
2858 : UserMapping *user_mapping;
2859 : ListCell *cell;
2860 : StringInfoData buf;
2861 : ForeignDataWrapper *fdw;
2862 : AclResult aclresult;
2863 : char *srvname;
2864 :
2865 : static const PQconninfoOption *options = NULL;
2866 :
2867 25 : initStringInfo(&buf);
2868 :
2869 : /*
2870 : * Get list of valid libpq options.
2871 : *
2872 : * To avoid unnecessary work, we get the list once and use it throughout
2873 : * the lifetime of this backend process. We don't need to care about
2874 : * memory context issues, because PQconndefaults allocates with malloc.
2875 : */
2876 25 : if (!options)
2877 : {
2878 6 : options = PQconndefaults();
2879 6 : if (!options) /* assume reason for failure is OOM */
2880 0 : ereport(ERROR,
2881 : (errcode(ERRCODE_FDW_OUT_OF_MEMORY),
2882 : errmsg("out of memory"),
2883 : errdetail("Could not get libpq's default connection options.")));
2884 : }
2885 :
2886 : /* first gather the server connstr options */
2887 25 : srvname = pstrdup(servername);
2888 25 : truncate_identifier(srvname, strlen(srvname), false);
2889 25 : foreign_server = GetForeignServerByName(srvname, true);
2890 :
2891 25 : if (foreign_server)
2892 : {
2893 5 : Oid serverid = foreign_server->serverid;
2894 5 : Oid fdwid = foreign_server->fdwid;
2895 5 : Oid userid = GetUserId();
2896 :
2897 5 : user_mapping = GetUserMapping(userid, serverid);
2898 5 : fdw = GetForeignDataWrapper(fdwid);
2899 :
2900 : /* Check permissions, user must have usage on the server. */
2901 5 : aclresult = object_aclcheck(ForeignServerRelationId, serverid, userid, ACL_USAGE);
2902 5 : if (aclresult != ACLCHECK_OK)
2903 0 : aclcheck_error(aclresult, OBJECT_FOREIGN_SERVER, foreign_server->servername);
2904 :
2905 : /*
2906 : * First append hardcoded options needed for SCRAM pass-through, so if
2907 : * the user overwrites these options we can ereport on
2908 : * dblink_connstr_check and dblink_security_check.
2909 : */
2910 5 : if (MyProcPort != NULL && MyProcPort->has_scram_keys && UseScramPassthrough(foreign_server, user_mapping))
2911 3 : appendSCRAMKeysInfo(&buf);
2912 :
2913 5 : foreach(cell, fdw->options)
2914 : {
2915 0 : DefElem *def = lfirst(cell);
2916 :
2917 0 : if (is_valid_dblink_option(options, def->defname, ForeignDataWrapperRelationId))
2918 0 : appendStringInfo(&buf, "%s='%s' ", def->defname,
2919 0 : escape_param_str(strVal(def->arg)));
2920 : }
2921 :
2922 22 : foreach(cell, foreign_server->options)
2923 : {
2924 17 : DefElem *def = lfirst(cell);
2925 :
2926 17 : if (is_valid_dblink_option(options, def->defname, ForeignServerRelationId))
2927 14 : appendStringInfo(&buf, "%s='%s' ", def->defname,
2928 14 : escape_param_str(strVal(def->arg)));
2929 : }
2930 :
2931 10 : foreach(cell, user_mapping->options)
2932 : {
2933 :
2934 5 : DefElem *def = lfirst(cell);
2935 :
2936 5 : if (is_valid_dblink_option(options, def->defname, UserMappingRelationId))
2937 5 : appendStringInfo(&buf, "%s='%s' ", def->defname,
2938 5 : escape_param_str(strVal(def->arg)));
2939 : }
2940 :
2941 5 : return buf.data;
2942 : }
2943 : else
2944 20 : return NULL;
2945 : }
2946 :
2947 : /*
2948 : * Escaping libpq connect parameter strings.
2949 : *
2950 : * Replaces "'" with "\'" and "\" with "\\".
2951 : */
2952 : static char *
2953 19 : escape_param_str(const char *str)
2954 : {
2955 : const char *cp;
2956 : StringInfoData buf;
2957 :
2958 19 : initStringInfo(&buf);
2959 :
2960 172 : for (cp = str; *cp; cp++)
2961 : {
2962 153 : if (*cp == '\\' || *cp == '\'')
2963 0 : appendStringInfoChar(&buf, '\\');
2964 153 : appendStringInfoChar(&buf, *cp);
2965 : }
2966 :
2967 19 : return buf.data;
2968 : }
2969 :
2970 : /*
2971 : * Validate the PK-attnums argument for dblink_build_sql_insert() and related
2972 : * functions, and translate to the internal representation.
2973 : *
2974 : * The user supplies an int2vector of 1-based logical attnums, plus a count
2975 : * argument (the need for the separate count argument is historical, but we
2976 : * still check it). We check that each attnum corresponds to a valid,
2977 : * non-dropped attribute of the rel. We do *not* prevent attnums from being
2978 : * listed twice, though the actual use-case for such things is dubious.
2979 : * Note that before Postgres 9.0, the user's attnums were interpreted as
2980 : * physical not logical column numbers; this was changed for future-proofing.
2981 : *
2982 : * The internal representation is a palloc'd int array of 0-based physical
2983 : * attnums.
2984 : */
2985 : static void
2986 18 : validate_pkattnums(Relation rel,
2987 : int2vector *pkattnums_arg, int32 pknumatts_arg,
2988 : int **pkattnums, int *pknumatts)
2989 : {
2990 18 : TupleDesc tupdesc = rel->rd_att;
2991 18 : int natts = tupdesc->natts;
2992 : int i;
2993 :
2994 : /* Don't take more array elements than there are */
2995 18 : pknumatts_arg = Min(pknumatts_arg, pkattnums_arg->dim1);
2996 :
2997 : /* Must have at least one pk attnum selected */
2998 18 : if (pknumatts_arg <= 0)
2999 0 : ereport(ERROR,
3000 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3001 : errmsg("number of key attributes must be > 0")));
3002 :
3003 : /* Allocate output array */
3004 18 : *pkattnums = palloc_array(int, pknumatts_arg);
3005 18 : *pknumatts = pknumatts_arg;
3006 :
3007 : /* Validate attnums and convert to internal form */
3008 57 : for (i = 0; i < pknumatts_arg; i++)
3009 : {
3010 45 : int pkattnum = pkattnums_arg->values[i];
3011 : int lnum;
3012 : int j;
3013 :
3014 : /* Can throw error immediately if out of range */
3015 45 : if (pkattnum <= 0 || pkattnum > natts)
3016 6 : ereport(ERROR,
3017 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3018 : errmsg("invalid attribute number %d", pkattnum)));
3019 :
3020 : /* Identify which physical column has this logical number */
3021 39 : lnum = 0;
3022 69 : for (j = 0; j < natts; j++)
3023 : {
3024 : /* dropped columns don't count */
3025 69 : if (TupleDescCompactAttr(tupdesc, j)->attisdropped)
3026 3 : continue;
3027 :
3028 66 : if (++lnum == pkattnum)
3029 39 : break;
3030 : }
3031 :
3032 39 : if (j < natts)
3033 39 : (*pkattnums)[i] = j;
3034 : else
3035 0 : ereport(ERROR,
3036 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3037 : errmsg("invalid attribute number %d", pkattnum)));
3038 : }
3039 12 : }
3040 :
3041 : /*
3042 : * Check if the specified connection option is valid.
3043 : *
3044 : * We basically allow whatever libpq thinks is an option, with these
3045 : * restrictions:
3046 : * debug options: disallowed
3047 : * "client_encoding": disallowed
3048 : * "user": valid only in USER MAPPING options
3049 : * secure options (eg password): valid only in USER MAPPING options
3050 : * others: valid only in FOREIGN SERVER options
3051 : *
3052 : * We disallow client_encoding because it would be overridden anyway via
3053 : * PQclientEncoding; allowing it to be specified would merely promote
3054 : * confusion.
3055 : */
3056 : static bool
3057 465 : is_valid_dblink_option(const PQconninfoOption *options, const char *option,
3058 : Oid context)
3059 : {
3060 : const PQconninfoOption *opt;
3061 :
3062 : /* Look up the option in libpq result */
3063 11545 : for (opt = options; opt->keyword; opt++)
3064 : {
3065 11540 : if (strcmp(opt->keyword, option) == 0)
3066 460 : break;
3067 : }
3068 465 : if (opt->keyword == NULL)
3069 5 : return false;
3070 :
3071 : /* Disallow debug options (particularly "replication") */
3072 460 : if (strchr(opt->dispchar, 'D'))
3073 34 : return false;
3074 :
3075 : /* Disallow "client_encoding" */
3076 426 : if (strcmp(opt->keyword, "client_encoding") == 0)
3077 8 : return false;
3078 :
3079 : /*
3080 : * Disallow OAuth options for now, since the builtin flow communicates on
3081 : * stderr by default and can't cache tokens yet.
3082 : */
3083 418 : if (strncmp(opt->keyword, "oauth_", strlen("oauth_")) == 0)
3084 36 : return false;
3085 :
3086 : /*
3087 : * If the option is "user" or marked secure, it should be specified only
3088 : * in USER MAPPING. Others should be specified only in SERVER.
3089 : */
3090 382 : if (strcmp(opt->keyword, "user") == 0 || strchr(opt->dispchar, '*'))
3091 : {
3092 37 : if (context != UserMappingRelationId)
3093 9 : return false;
3094 : }
3095 : else
3096 : {
3097 345 : if (context != ForeignServerRelationId)
3098 234 : return false;
3099 : }
3100 :
3101 139 : return true;
3102 : }
3103 :
3104 : /*
3105 : * Same as is_valid_dblink_option but also check for only dblink_fdw specific
3106 : * options.
3107 : */
3108 : static bool
3109 39 : is_valid_dblink_fdw_option(const PQconninfoOption *options, const char *option,
3110 : Oid context)
3111 : {
3112 39 : if (strcmp(option, "use_scram_passthrough") == 0)
3113 4 : return true;
3114 :
3115 35 : return is_valid_dblink_option(options, option, context);
3116 : }
3117 :
3118 : /*
3119 : * Copy the remote session's values of GUCs that affect datatype I/O
3120 : * and apply them locally in a new GUC nesting level. Returns the new
3121 : * nestlevel (which is needed by restoreLocalGucs to undo the settings),
3122 : * or -1 if no new nestlevel was needed.
3123 : *
3124 : * We use the equivalent of a function SET option to allow the settings to
3125 : * persist only until the caller calls restoreLocalGucs. If an error is
3126 : * thrown in between, guc.c will take care of undoing the settings.
3127 : */
3128 : static int
3129 34 : applyRemoteGucs(PGconn *conn)
3130 : {
3131 : static const char *const GUCsAffectingIO[] = {
3132 : "DateStyle",
3133 : "IntervalStyle"
3134 : };
3135 :
3136 34 : int nestlevel = -1;
3137 : int i;
3138 :
3139 102 : for (i = 0; i < lengthof(GUCsAffectingIO); i++)
3140 : {
3141 68 : const char *gucName = GUCsAffectingIO[i];
3142 68 : const char *remoteVal = PQparameterStatus(conn, gucName);
3143 : const char *localVal;
3144 :
3145 : /*
3146 : * If the remote server is pre-8.4, it won't have IntervalStyle, but
3147 : * that's okay because its output format won't be ambiguous. So just
3148 : * skip the GUC if we don't get a value for it. (We might eventually
3149 : * need more complicated logic with remote-version checks here.)
3150 : */
3151 68 : if (remoteVal == NULL)
3152 0 : continue;
3153 :
3154 : /*
3155 : * Avoid GUC-setting overhead if the remote and local GUCs already
3156 : * have the same value.
3157 : */
3158 68 : localVal = GetConfigOption(gucName, false, false);
3159 : Assert(localVal != NULL);
3160 :
3161 68 : if (strcmp(remoteVal, localVal) == 0)
3162 51 : continue;
3163 :
3164 : /* Create new GUC nest level if we didn't already */
3165 17 : if (nestlevel < 0)
3166 9 : nestlevel = NewGUCNestLevel();
3167 :
3168 : /* Apply the option (this will throw error on failure) */
3169 17 : (void) set_config_option(gucName, remoteVal,
3170 : PGC_USERSET, PGC_S_SESSION,
3171 : GUC_ACTION_SAVE, true, 0, false);
3172 : }
3173 :
3174 34 : return nestlevel;
3175 : }
3176 :
3177 : /*
3178 : * Restore local GUCs after they have been overlaid with remote settings.
3179 : */
3180 : static void
3181 35 : restoreLocalGucs(int nestlevel)
3182 : {
3183 : /* Do nothing if no new nestlevel was created */
3184 35 : if (nestlevel > 0)
3185 8 : AtEOXact_GUC(true, nestlevel);
3186 35 : }
3187 :
3188 : /*
3189 : * Append SCRAM client key and server key information from the global
3190 : * MyProcPort into the given StringInfo buffer.
3191 : */
3192 : static void
3193 3 : appendSCRAMKeysInfo(StringInfo buf)
3194 : {
3195 : int len;
3196 : int encoded_len;
3197 : char *client_key;
3198 : char *server_key;
3199 :
3200 3 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ClientKey));
3201 : /* don't forget the zero-terminator */
3202 3 : client_key = palloc0(len + 1);
3203 3 : encoded_len = pg_b64_encode(MyProcPort->scram_ClientKey,
3204 : sizeof(MyProcPort->scram_ClientKey),
3205 : client_key, len);
3206 3 : if (encoded_len < 0)
3207 0 : elog(ERROR, "could not encode SCRAM client key");
3208 :
3209 3 : len = pg_b64_enc_len(sizeof(MyProcPort->scram_ServerKey));
3210 : /* don't forget the zero-terminator */
3211 3 : server_key = palloc0(len + 1);
3212 3 : encoded_len = pg_b64_encode(MyProcPort->scram_ServerKey,
3213 : sizeof(MyProcPort->scram_ServerKey),
3214 : server_key, len);
3215 3 : if (encoded_len < 0)
3216 0 : elog(ERROR, "could not encode SCRAM server key");
3217 :
3218 3 : appendStringInfo(buf, "scram_client_key='%s' ", client_key);
3219 3 : appendStringInfo(buf, "scram_server_key='%s' ", server_key);
3220 3 : appendStringInfoString(buf, "require_auth='scram-sha-256' ");
3221 :
3222 3 : pfree(client_key);
3223 3 : pfree(server_key);
3224 3 : }
3225 :
3226 :
3227 : static bool
3228 3 : UseScramPassthrough(ForeignServer *foreign_server, UserMapping *user)
3229 : {
3230 : ListCell *cell;
3231 :
3232 12 : foreach(cell, foreign_server->options)
3233 : {
3234 12 : DefElem *def = lfirst(cell);
3235 :
3236 12 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
3237 3 : return defGetBoolean(def);
3238 : }
3239 :
3240 0 : foreach(cell, user->options)
3241 : {
3242 0 : DefElem *def = (DefElem *) lfirst(cell);
3243 :
3244 0 : if (strcmp(def->defname, "use_scram_passthrough") == 0)
3245 0 : return defGetBoolean(def);
3246 : }
3247 :
3248 0 : return false;
3249 : }
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