Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * option.c
4 : * FDW and GUC option handling for postgres_fdw
5 : *
6 : * Portions Copyright (c) 2012-2026, PostgreSQL Global Development Group
7 : *
8 : * IDENTIFICATION
9 : * contrib/postgres_fdw/option.c
10 : *
11 : *-------------------------------------------------------------------------
12 : */
13 : #include "postgres.h"
14 :
15 : #include "access/reloptions.h"
16 : #include "catalog/pg_foreign_server.h"
17 : #include "catalog/pg_foreign_table.h"
18 : #include "catalog/pg_user_mapping.h"
19 : #include "commands/defrem.h"
20 : #include "commands/extension.h"
21 : #include "libpq/libpq-be.h"
22 : #include "postgres_fdw.h"
23 : #include "utils/guc.h"
24 : #include "utils/memutils.h"
25 : #include "utils/varlena.h"
26 :
27 : /*
28 : * Describes the valid options for objects that this wrapper uses.
29 : */
30 : typedef struct PgFdwOption
31 : {
32 : const char *keyword;
33 : Oid optcontext; /* OID of catalog in which option may appear */
34 : bool is_libpq_opt; /* true if it's used in libpq */
35 : } PgFdwOption;
36 :
37 : /*
38 : * Valid options for postgres_fdw.
39 : * Allocated and filled in InitPgFdwOptions.
40 : */
41 : static PgFdwOption *postgres_fdw_options;
42 :
43 : /*
44 : * GUC parameters
45 : */
46 : char *pgfdw_application_name = NULL;
47 :
48 : /*
49 : * Helper functions
50 : */
51 : static void InitPgFdwOptions(void);
52 : static bool is_valid_option(const char *keyword, Oid context);
53 : static bool is_libpq_option(const char *keyword);
54 :
55 : #include "miscadmin.h"
56 :
57 : /*
58 : * Validate the generic options given to a FOREIGN DATA WRAPPER, SERVER,
59 : * USER MAPPING or FOREIGN TABLE that uses postgres_fdw.
60 : *
61 : * Raise an ERROR if the option or its value is considered invalid.
62 : */
63 18 : PG_FUNCTION_INFO_V1(postgres_fdw_validator);
64 :
65 : Datum
66 323 : postgres_fdw_validator(PG_FUNCTION_ARGS)
67 : {
68 323 : List *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
69 323 : Oid catalog = PG_GETARG_OID(1);
70 : ListCell *cell;
71 :
72 : /* Build our options lists if we didn't yet. */
73 323 : InitPgFdwOptions();
74 :
75 : /*
76 : * Check that only options supported by postgres_fdw, and allowed for the
77 : * current object type, are given.
78 : */
79 1046 : foreach(cell, options_list)
80 : {
81 739 : DefElem *def = (DefElem *) lfirst(cell);
82 :
83 739 : if (!is_valid_option(def->defname, catalog))
84 : {
85 : /*
86 : * Unknown option specified, complain about it. Provide a hint
87 : * with a valid option that looks similar, if there is one.
88 : */
89 : PgFdwOption *opt;
90 : const char *closest_match;
91 : ClosestMatchState match_state;
92 7 : bool has_valid_options = false;
93 :
94 7 : initClosestMatch(&match_state, def->defname, 4);
95 511 : for (opt = postgres_fdw_options; opt->keyword; opt++)
96 : {
97 504 : if (catalog == opt->optcontext)
98 : {
99 183 : has_valid_options = true;
100 183 : updateClosestMatch(&match_state, opt->keyword);
101 : }
102 : }
103 :
104 7 : closest_match = getClosestMatch(&match_state);
105 7 : ereport(ERROR,
106 : (errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
107 : errmsg("invalid option \"%s\"", def->defname),
108 : has_valid_options ? closest_match ?
109 : errhint("Perhaps you meant the option \"%s\".",
110 : closest_match) : 0 :
111 : errhint("There are no valid options in this context.")));
112 : }
113 :
114 : /*
115 : * Validate option value, when we can do so without any context.
116 : */
117 732 : if (strcmp(def->defname, "use_remote_estimate") == 0 ||
118 693 : strcmp(def->defname, "updatable") == 0 ||
119 687 : strcmp(def->defname, "truncatable") == 0 ||
120 682 : strcmp(def->defname, "async_capable") == 0 ||
121 678 : strcmp(def->defname, "parallel_commit") == 0 ||
122 674 : strcmp(def->defname, "parallel_abort") == 0 ||
123 670 : strcmp(def->defname, "keep_connections") == 0 ||
124 652 : strcmp(def->defname, "restore_stats") == 0)
125 : {
126 : /* these accept only boolean values */
127 82 : (void) defGetBoolean(def);
128 : }
129 650 : else if (strcmp(def->defname, "fdw_startup_cost") == 0 ||
130 641 : strcmp(def->defname, "fdw_tuple_cost") == 0)
131 15 : {
132 : /*
133 : * These must have a floating point value greater than or equal to
134 : * zero.
135 : */
136 : char *value;
137 : double real_val;
138 : bool is_parsed;
139 :
140 17 : value = defGetString(def);
141 17 : is_parsed = parse_real(value, &real_val, 0, NULL);
142 :
143 17 : if (!is_parsed)
144 2 : ereport(ERROR,
145 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
146 : errmsg("invalid value for floating point option \"%s\": %s",
147 : def->defname, value)));
148 :
149 15 : if (real_val < 0)
150 0 : ereport(ERROR,
151 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
152 : errmsg("\"%s\" must be a floating point value greater than or equal to zero",
153 : def->defname)));
154 : }
155 633 : else if (strcmp(def->defname, "extensions") == 0)
156 : {
157 : /* check list syntax, warn about uninstalled extensions */
158 33 : (void) ExtractExtensionList(defGetString(def), true);
159 : }
160 600 : else if (strcmp(def->defname, "fetch_size") == 0 ||
161 595 : strcmp(def->defname, "batch_size") == 0)
162 24 : {
163 : char *value;
164 : int int_val;
165 : bool is_parsed;
166 :
167 26 : value = defGetString(def);
168 26 : is_parsed = parse_int(value, &int_val, 0, NULL);
169 :
170 26 : if (!is_parsed)
171 2 : ereport(ERROR,
172 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
173 : errmsg("invalid value for integer option \"%s\": %s",
174 : def->defname, value)));
175 :
176 24 : if (int_val <= 0)
177 0 : ereport(ERROR,
178 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
179 : errmsg("\"%s\" must be an integer value greater than zero",
180 : def->defname)));
181 : }
182 574 : else if (strcmp(def->defname, "password_required") == 0)
183 : {
184 6 : bool pw_required = defGetBoolean(def);
185 :
186 : /*
187 : * Only the superuser may set this option on a user mapping, or
188 : * alter a user mapping on which this option is set. We allow a
189 : * user to clear this option if it's set - in fact, we don't have
190 : * a choice since we can't see the old mapping when validating an
191 : * alter.
192 : */
193 6 : if (!superuser() && !pw_required)
194 1 : ereport(ERROR,
195 : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
196 : errmsg("password_required=false is superuser-only"),
197 : errhint("User mappings with the password_required option set to false may only be created or modified by the superuser.")));
198 : }
199 568 : else if (strcmp(def->defname, "sslcert") == 0 ||
200 558 : strcmp(def->defname, "sslkey") == 0)
201 : {
202 : /* similarly for sslcert / sslkey on user mapping */
203 20 : if (catalog == UserMappingRelationId && !superuser())
204 2 : ereport(ERROR,
205 : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
206 : errmsg("sslcert and sslkey are superuser-only"),
207 : errhint("User mappings with the sslcert or sslkey options set may only be created or modified by the superuser.")));
208 : }
209 548 : else if (strcmp(def->defname, "analyze_sampling") == 0)
210 : {
211 : char *value;
212 :
213 7 : value = defGetString(def);
214 :
215 : /* we recognize off/auto/random/system/bernoulli */
216 7 : if (strcmp(value, "off") != 0 &&
217 5 : strcmp(value, "auto") != 0 &&
218 4 : strcmp(value, "random") != 0 &&
219 3 : strcmp(value, "system") != 0 &&
220 2 : strcmp(value, "bernoulli") != 0)
221 1 : ereport(ERROR,
222 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
223 : errmsg("invalid value for string option \"%s\": %s",
224 : def->defname, value)));
225 : }
226 : }
227 :
228 307 : PG_RETURN_VOID();
229 : }
230 :
231 : /*
232 : * Initialize option lists.
233 : */
234 : static void
235 517 : InitPgFdwOptions(void)
236 : {
237 : int num_libpq_opts;
238 : PQconninfoOption *libpq_options;
239 : PQconninfoOption *lopt;
240 : PgFdwOption *popt;
241 :
242 : /* non-libpq FDW-specific FDW options */
243 : static const PgFdwOption non_libpq_options[] = {
244 : {"schema_name", ForeignTableRelationId, false},
245 : {"table_name", ForeignTableRelationId, false},
246 : {"column_name", AttributeRelationId, false},
247 : /* use_remote_estimate is available on both server and table */
248 : {"use_remote_estimate", ForeignServerRelationId, false},
249 : {"use_remote_estimate", ForeignTableRelationId, false},
250 : /* cost factors */
251 : {"fdw_startup_cost", ForeignServerRelationId, false},
252 : {"fdw_tuple_cost", ForeignServerRelationId, false},
253 : /* shippable extensions */
254 : {"extensions", ForeignServerRelationId, false},
255 : /* updatable is available on both server and table */
256 : {"updatable", ForeignServerRelationId, false},
257 : {"updatable", ForeignTableRelationId, false},
258 : /* truncatable is available on both server and table */
259 : {"truncatable", ForeignServerRelationId, false},
260 : {"truncatable", ForeignTableRelationId, false},
261 : /* fetch_size is available on both server and table */
262 : {"fetch_size", ForeignServerRelationId, false},
263 : {"fetch_size", ForeignTableRelationId, false},
264 : /* batch_size is available on both server and table */
265 : {"batch_size", ForeignServerRelationId, false},
266 : {"batch_size", ForeignTableRelationId, false},
267 : /* async_capable is available on both server and table */
268 : {"async_capable", ForeignServerRelationId, false},
269 : {"async_capable", ForeignTableRelationId, false},
270 : {"parallel_commit", ForeignServerRelationId, false},
271 : {"parallel_abort", ForeignServerRelationId, false},
272 : {"keep_connections", ForeignServerRelationId, false},
273 : {"password_required", UserMappingRelationId, false},
274 :
275 : /* sampling is available on both server and table */
276 : {"analyze_sampling", ForeignServerRelationId, false},
277 : {"analyze_sampling", ForeignTableRelationId, false},
278 : /* restore_stats is available on both server and table */
279 : {"restore_stats", ForeignServerRelationId, false},
280 : {"restore_stats", ForeignTableRelationId, false},
281 :
282 : {"use_scram_passthrough", ForeignServerRelationId, false},
283 : {"use_scram_passthrough", UserMappingRelationId, false},
284 :
285 : /*
286 : * sslcert and sslkey are in fact libpq options, but we repeat them
287 : * here to allow them to appear in both foreign server context (when
288 : * we generate libpq options) and user mapping context (from here).
289 : */
290 : {"sslcert", UserMappingRelationId, true},
291 : {"sslkey", UserMappingRelationId, true},
292 :
293 : /*
294 : * gssdelegation is also a libpq option but should be allowed in a
295 : * user mapping context too
296 : */
297 : {"gssdelegation", UserMappingRelationId, true},
298 :
299 : {NULL, InvalidOid, false}
300 : };
301 :
302 : /* Prevent redundant initialization. */
303 517 : if (postgres_fdw_options)
304 487 : return;
305 :
306 : /*
307 : * Get list of valid libpq options.
308 : *
309 : * To avoid unnecessary work, we get the list once and use it throughout
310 : * the lifetime of this backend process. Hence, we'll allocate it in
311 : * TopMemoryContext.
312 : */
313 30 : libpq_options = PQconndefaults();
314 30 : if (!libpq_options) /* assume reason for failure is OOM */
315 0 : ereport(ERROR,
316 : (errcode(ERRCODE_FDW_OUT_OF_MEMORY),
317 : errmsg("out of memory"),
318 : errdetail("Could not get libpq's default connection options.")));
319 :
320 : /* Count how many libpq options are available. */
321 30 : num_libpq_opts = 0;
322 1590 : for (lopt = libpq_options; lopt->keyword; lopt++)
323 1560 : num_libpq_opts++;
324 :
325 : /*
326 : * Construct an array which consists of all valid options for
327 : * postgres_fdw, by appending FDW-specific options to libpq options.
328 : */
329 30 : postgres_fdw_options = (PgFdwOption *)
330 30 : MemoryContextAlloc(TopMemoryContext,
331 30 : sizeof(PgFdwOption) * num_libpq_opts +
332 : sizeof(non_libpq_options));
333 :
334 30 : popt = postgres_fdw_options;
335 1590 : for (lopt = libpq_options; lopt->keyword; lopt++)
336 : {
337 : /* Hide debug options, as well as settings we override internally. */
338 1560 : if (strchr(lopt->dispchar, 'D') ||
339 1440 : strcmp(lopt->keyword, "fallback_application_name") == 0 ||
340 1410 : strcmp(lopt->keyword, "client_encoding") == 0)
341 180 : continue;
342 :
343 : /*
344 : * Disallow OAuth options for now, since the builtin flow communicates
345 : * on stderr by default and can't cache tokens yet.
346 : */
347 1380 : if (strncmp(lopt->keyword, "oauth_", strlen("oauth_")) == 0)
348 150 : continue;
349 :
350 2460 : popt->keyword = MemoryContextStrdup(TopMemoryContext,
351 1230 : lopt->keyword);
352 :
353 : /*
354 : * "user" and any secret options are allowed only on user mappings.
355 : * Everything else is a server option.
356 : */
357 1230 : if (strcmp(lopt->keyword, "user") == 0 || strchr(lopt->dispchar, '*'))
358 90 : popt->optcontext = UserMappingRelationId;
359 : else
360 1140 : popt->optcontext = ForeignServerRelationId;
361 1230 : popt->is_libpq_opt = true;
362 :
363 1230 : popt++;
364 : }
365 :
366 : /* Done with libpq's output structure. */
367 30 : PQconninfoFree(libpq_options);
368 :
369 : /* Append FDW-specific options and dummy terminator. */
370 30 : memcpy(popt, non_libpq_options, sizeof(non_libpq_options));
371 : }
372 :
373 : /*
374 : * Check whether the given option is one of the valid postgres_fdw options.
375 : * context is the Oid of the catalog holding the object the option is for.
376 : */
377 : static bool
378 739 : is_valid_option(const char *keyword, Oid context)
379 : {
380 : PgFdwOption *opt;
381 :
382 : Assert(postgres_fdw_options); /* must be initialized already */
383 :
384 24498 : for (opt = postgres_fdw_options; opt->keyword; opt++)
385 : {
386 24491 : if (context == opt->optcontext && strcmp(opt->keyword, keyword) == 0)
387 732 : return true;
388 : }
389 :
390 7 : return false;
391 : }
392 :
393 : /*
394 : * Check whether the given option is one of the valid libpq options.
395 : */
396 : static bool
397 408 : is_libpq_option(const char *keyword)
398 : {
399 : PgFdwOption *opt;
400 :
401 : Assert(postgres_fdw_options); /* must be initialized already */
402 :
403 12096 : for (opt = postgres_fdw_options; opt->keyword; opt++)
404 : {
405 11974 : if (opt->is_libpq_opt && strcmp(opt->keyword, keyword) == 0)
406 286 : return true;
407 : }
408 :
409 122 : return false;
410 : }
411 :
412 : /*
413 : * Generate key-value arrays which include only libpq options from the
414 : * given list (which can contain any kind of options). Caller must have
415 : * allocated large-enough arrays. Returns number of options found.
416 : */
417 : int
418 194 : ExtractConnectionOptions(List *defelems, const char **keywords,
419 : const char **values)
420 : {
421 : ListCell *lc;
422 : int i;
423 :
424 : /* Build our options lists if we didn't yet. */
425 194 : InitPgFdwOptions();
426 :
427 194 : i = 0;
428 602 : foreach(lc, defelems)
429 : {
430 408 : DefElem *d = (DefElem *) lfirst(lc);
431 :
432 408 : if (is_libpq_option(d->defname))
433 : {
434 286 : keywords[i] = d->defname;
435 286 : values[i] = defGetString(d);
436 286 : i++;
437 : }
438 : }
439 194 : return i;
440 : }
441 :
442 : /*
443 : * Parse a comma-separated string and return a List of the OIDs of the
444 : * extensions named in the string. If any names in the list cannot be
445 : * found, report a warning if warnOnMissing is true, else just silently
446 : * ignore them.
447 : */
448 : List *
449 963 : ExtractExtensionList(const char *extensionsString, bool warnOnMissing)
450 : {
451 963 : List *extensionOids = NIL;
452 : List *extlist;
453 : ListCell *lc;
454 :
455 : /* SplitIdentifierString scribbles on its input, so pstrdup first */
456 963 : if (!SplitIdentifierString(pstrdup(extensionsString), ',', &extlist))
457 : {
458 : /* syntax error in name list */
459 1 : ereport(ERROR,
460 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
461 : errmsg("parameter \"%s\" must be a list of extension names",
462 : "extensions")));
463 : }
464 :
465 1925 : foreach(lc, extlist)
466 : {
467 963 : const char *extension_name = (const char *) lfirst(lc);
468 963 : Oid extension_oid = get_extension_oid(extension_name, true);
469 :
470 963 : if (OidIsValid(extension_oid))
471 : {
472 961 : extensionOids = lappend_oid(extensionOids, extension_oid);
473 : }
474 2 : else if (warnOnMissing)
475 : {
476 2 : ereport(WARNING,
477 : (errcode(ERRCODE_UNDEFINED_OBJECT),
478 : errmsg("extension \"%s\" is not installed",
479 : extension_name)));
480 : }
481 : }
482 :
483 962 : list_free(extlist);
484 962 : return extensionOids;
485 : }
486 :
487 : /*
488 : * Replace escape sequences beginning with % character in the given
489 : * application_name with status information, and return it.
490 : *
491 : * This function always returns a palloc'd string, so the caller is
492 : * responsible for pfreeing it.
493 : */
494 : char *
495 28 : process_pgfdw_appname(const char *appname)
496 : {
497 : const char *p;
498 : StringInfoData buf;
499 :
500 28 : initStringInfo(&buf);
501 :
502 389 : for (p = appname; *p != '\0'; p++)
503 : {
504 361 : if (*p != '%')
505 : {
506 : /* literal char, just copy */
507 352 : appendStringInfoChar(&buf, *p);
508 352 : continue;
509 : }
510 :
511 : /* must be a '%', so skip to the next char */
512 9 : p++;
513 9 : if (*p == '\0')
514 0 : break; /* format error - ignore it */
515 9 : else if (*p == '%')
516 : {
517 : /* string contains %% */
518 1 : appendStringInfoChar(&buf, '%');
519 1 : continue;
520 : }
521 :
522 : /* process the option */
523 8 : switch (*p)
524 : {
525 1 : case 'a':
526 1 : appendStringInfoString(&buf, application_name);
527 1 : break;
528 2 : case 'c':
529 2 : appendStringInfo(&buf, "%" PRIx64 ".%x", MyStartTime, MyProcPid);
530 2 : break;
531 2 : case 'C':
532 2 : appendStringInfoString(&buf, cluster_name);
533 2 : break;
534 1 : case 'd':
535 1 : if (MyProcPort)
536 : {
537 1 : const char *dbname = MyProcPort->database_name;
538 :
539 1 : if (dbname)
540 1 : appendStringInfoString(&buf, dbname);
541 : else
542 0 : appendStringInfoString(&buf, "[unknown]");
543 : }
544 1 : break;
545 1 : case 'p':
546 1 : appendStringInfo(&buf, "%d", MyProcPid);
547 1 : break;
548 1 : case 'u':
549 1 : if (MyProcPort)
550 : {
551 1 : const char *username = MyProcPort->user_name;
552 :
553 1 : if (username)
554 1 : appendStringInfoString(&buf, username);
555 : else
556 0 : appendStringInfoString(&buf, "[unknown]");
557 : }
558 1 : break;
559 0 : default:
560 : /* format error - ignore it */
561 0 : break;
562 : }
563 : }
564 :
565 28 : return buf.data;
566 : }
567 :
568 : /*
569 : * Module load callback
570 : */
571 : void
572 30 : _PG_init(void)
573 : {
574 : /*
575 : * Unlike application_name GUC, don't set GUC_IS_NAME flag nor check_hook
576 : * to allow postgres_fdw.application_name to be any string more than
577 : * NAMEDATALEN characters and to include non-ASCII characters. Instead,
578 : * remote server truncates application_name of remote connection to less
579 : * than NAMEDATALEN and replaces any non-ASCII characters in it with a '?'
580 : * character.
581 : */
582 30 : DefineCustomStringVariable("postgres_fdw.application_name",
583 : "Sets the application name to be used on the remote server.",
584 : NULL,
585 : &pgfdw_application_name,
586 : NULL,
587 : PGC_USERSET,
588 : 0,
589 : NULL,
590 : NULL,
591 : NULL);
592 :
593 30 : MarkGUCPrefixReserved("postgres_fdw");
594 30 : }
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