Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * option.c
4 : * FDW and GUC option handling for postgres_fdw
5 : *
6 : * Portions Copyright (c) 2012-2024, 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/builtins.h"
24 : #include "utils/guc.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 : * Valid options for libpq.
45 : * Allocated and filled in InitPgFdwOptions.
46 : */
47 : static PQconninfoOption *libpq_options;
48 :
49 : /*
50 : * GUC parameters
51 : */
52 : char *pgfdw_application_name = NULL;
53 :
54 : /*
55 : * Helper functions
56 : */
57 : static void InitPgFdwOptions(void);
58 : static bool is_valid_option(const char *keyword, Oid context);
59 : static bool is_libpq_option(const char *keyword);
60 :
61 : #include "miscadmin.h"
62 :
63 : /*
64 : * Validate the generic options given to a FOREIGN DATA WRAPPER, SERVER,
65 : * USER MAPPING or FOREIGN TABLE that uses postgres_fdw.
66 : *
67 : * Raise an ERROR if the option or its value is considered invalid.
68 : */
69 6 : PG_FUNCTION_INFO_V1(postgres_fdw_validator);
70 :
71 : Datum
72 538 : postgres_fdw_validator(PG_FUNCTION_ARGS)
73 : {
74 538 : List *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
75 538 : Oid catalog = PG_GETARG_OID(1);
76 : ListCell *cell;
77 :
78 : /* Build our options lists if we didn't yet. */
79 538 : InitPgFdwOptions();
80 :
81 : /*
82 : * Check that only options supported by postgres_fdw, and allowed for the
83 : * current object type, are given.
84 : */
85 1730 : foreach(cell, options_list)
86 : {
87 1216 : DefElem *def = (DefElem *) lfirst(cell);
88 :
89 1216 : if (!is_valid_option(def->defname, catalog))
90 : {
91 : /*
92 : * Unknown option specified, complain about it. Provide a hint
93 : * with a valid option that looks similar, if there is one.
94 : */
95 : PgFdwOption *opt;
96 : const char *closest_match;
97 : ClosestMatchState match_state;
98 6 : bool has_valid_options = false;
99 :
100 6 : initClosestMatch(&match_state, def->defname, 4);
101 396 : for (opt = postgres_fdw_options; opt->keyword; opt++)
102 : {
103 390 : if (catalog == opt->optcontext)
104 : {
105 110 : has_valid_options = true;
106 110 : updateClosestMatch(&match_state, opt->keyword);
107 : }
108 : }
109 :
110 6 : closest_match = getClosestMatch(&match_state);
111 6 : ereport(ERROR,
112 : (errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
113 : errmsg("invalid option \"%s\"", def->defname),
114 : has_valid_options ? closest_match ?
115 : errhint("Perhaps you meant the option \"%s\".",
116 : closest_match) : 0 :
117 : errhint("There are no valid options in this context.")));
118 : }
119 :
120 : /*
121 : * Validate option value, when we can do so without any context.
122 : */
123 1210 : if (strcmp(def->defname, "use_remote_estimate") == 0 ||
124 1146 : strcmp(def->defname, "updatable") == 0 ||
125 1138 : strcmp(def->defname, "truncatable") == 0 ||
126 1128 : strcmp(def->defname, "async_capable") == 0 ||
127 1120 : strcmp(def->defname, "parallel_commit") == 0 ||
128 1112 : strcmp(def->defname, "parallel_abort") == 0 ||
129 1104 : strcmp(def->defname, "keep_connections") == 0)
130 : {
131 : /* these accept only boolean values */
132 140 : (void) defGetBoolean(def);
133 : }
134 1070 : else if (strcmp(def->defname, "fdw_startup_cost") == 0 ||
135 1056 : strcmp(def->defname, "fdw_tuple_cost") == 0)
136 22 : {
137 : /*
138 : * These must have a floating point value greater than or equal to
139 : * zero.
140 : */
141 : char *value;
142 : double real_val;
143 : bool is_parsed;
144 :
145 26 : value = defGetString(def);
146 26 : is_parsed = parse_real(value, &real_val, 0, NULL);
147 :
148 26 : if (!is_parsed)
149 4 : ereport(ERROR,
150 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
151 : errmsg("invalid value for floating point option \"%s\": %s",
152 : def->defname, value)));
153 :
154 22 : if (real_val < 0)
155 0 : ereport(ERROR,
156 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
157 : errmsg("\"%s\" must be a floating point value greater than or equal to zero",
158 : def->defname)));
159 : }
160 1044 : else if (strcmp(def->defname, "extensions") == 0)
161 : {
162 : /* check list syntax, warn about uninstalled extensions */
163 62 : (void) ExtractExtensionList(defGetString(def), true);
164 : }
165 982 : else if (strcmp(def->defname, "fetch_size") == 0 ||
166 972 : strcmp(def->defname, "batch_size") == 0)
167 46 : {
168 : char *value;
169 : int int_val;
170 : bool is_parsed;
171 :
172 50 : value = defGetString(def);
173 50 : is_parsed = parse_int(value, &int_val, 0, NULL);
174 :
175 50 : if (!is_parsed)
176 4 : ereport(ERROR,
177 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
178 : errmsg("invalid value for integer option \"%s\": %s",
179 : def->defname, value)));
180 :
181 46 : if (int_val <= 0)
182 0 : ereport(ERROR,
183 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
184 : errmsg("\"%s\" must be an integer value greater than zero",
185 : def->defname)));
186 : }
187 932 : else if (strcmp(def->defname, "password_required") == 0)
188 : {
189 12 : bool pw_required = defGetBoolean(def);
190 :
191 : /*
192 : * Only the superuser may set this option on a user mapping, or
193 : * alter a user mapping on which this option is set. We allow a
194 : * user to clear this option if it's set - in fact, we don't have
195 : * a choice since we can't see the old mapping when validating an
196 : * alter.
197 : */
198 12 : if (!superuser() && !pw_required)
199 2 : ereport(ERROR,
200 : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
201 : errmsg("password_required=false is superuser-only"),
202 : errhint("User mappings with the password_required option set to false may only be created or modified by the superuser.")));
203 : }
204 920 : else if (strcmp(def->defname, "sslcert") == 0 ||
205 908 : strcmp(def->defname, "sslkey") == 0)
206 : {
207 : /* similarly for sslcert / sslkey on user mapping */
208 24 : if (catalog == UserMappingRelationId && !superuser())
209 4 : ereport(ERROR,
210 : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
211 : errmsg("sslcert and sslkey are superuser-only"),
212 : errhint("User mappings with the sslcert or sslkey options set may only be created or modified by the superuser.")));
213 : }
214 896 : else if (strcmp(def->defname, "analyze_sampling") == 0)
215 : {
216 : char *value;
217 :
218 12 : value = defGetString(def);
219 :
220 : /* we recognize off/auto/random/system/bernoulli */
221 12 : if (strcmp(value, "off") != 0 &&
222 10 : strcmp(value, "auto") != 0 &&
223 8 : strcmp(value, "random") != 0 &&
224 6 : strcmp(value, "system") != 0 &&
225 4 : strcmp(value, "bernoulli") != 0)
226 2 : ereport(ERROR,
227 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
228 : errmsg("invalid value for string option \"%s\": %s",
229 : def->defname, value)));
230 : }
231 : }
232 :
233 514 : PG_RETURN_VOID();
234 : }
235 :
236 : /*
237 : * Initialize option lists.
238 : */
239 : static void
240 798 : InitPgFdwOptions(void)
241 : {
242 : int num_libpq_opts;
243 : PQconninfoOption *lopt;
244 : PgFdwOption *popt;
245 :
246 : /* non-libpq FDW-specific FDW options */
247 : static const PgFdwOption non_libpq_options[] = {
248 : {"schema_name", ForeignTableRelationId, false},
249 : {"table_name", ForeignTableRelationId, false},
250 : {"column_name", AttributeRelationId, false},
251 : /* use_remote_estimate is available on both server and table */
252 : {"use_remote_estimate", ForeignServerRelationId, false},
253 : {"use_remote_estimate", ForeignTableRelationId, false},
254 : /* cost factors */
255 : {"fdw_startup_cost", ForeignServerRelationId, false},
256 : {"fdw_tuple_cost", ForeignServerRelationId, false},
257 : /* shippable extensions */
258 : {"extensions", ForeignServerRelationId, false},
259 : /* updatable is available on both server and table */
260 : {"updatable", ForeignServerRelationId, false},
261 : {"updatable", ForeignTableRelationId, false},
262 : /* truncatable is available on both server and table */
263 : {"truncatable", ForeignServerRelationId, false},
264 : {"truncatable", ForeignTableRelationId, false},
265 : /* fetch_size is available on both server and table */
266 : {"fetch_size", ForeignServerRelationId, false},
267 : {"fetch_size", ForeignTableRelationId, false},
268 : /* batch_size is available on both server and table */
269 : {"batch_size", ForeignServerRelationId, false},
270 : {"batch_size", ForeignTableRelationId, false},
271 : /* async_capable is available on both server and table */
272 : {"async_capable", ForeignServerRelationId, false},
273 : {"async_capable", ForeignTableRelationId, false},
274 : {"parallel_commit", ForeignServerRelationId, false},
275 : {"parallel_abort", ForeignServerRelationId, false},
276 : {"keep_connections", ForeignServerRelationId, false},
277 : {"password_required", UserMappingRelationId, false},
278 :
279 : /* sampling is available on both server and table */
280 : {"analyze_sampling", ForeignServerRelationId, false},
281 : {"analyze_sampling", ForeignTableRelationId, false},
282 :
283 : /*
284 : * sslcert and sslkey are in fact libpq options, but we repeat them
285 : * here to allow them to appear in both foreign server context (when
286 : * we generate libpq options) and user mapping context (from here).
287 : */
288 : {"sslcert", UserMappingRelationId, true},
289 : {"sslkey", UserMappingRelationId, true},
290 :
291 : /*
292 : * gssdelegation is also a libpq option but should be allowed in a
293 : * user mapping context too
294 : */
295 : {"gssdelegation", UserMappingRelationId, true},
296 :
297 : {NULL, InvalidOid, false}
298 : };
299 :
300 : /* Prevent redundant initialization. */
301 798 : if (postgres_fdw_options)
302 790 : return;
303 :
304 : /*
305 : * Get list of valid libpq options.
306 : *
307 : * To avoid unnecessary work, we get the list once and use it throughout
308 : * the lifetime of this backend process. We don't need to care about
309 : * memory context issues, because PQconndefaults allocates with malloc.
310 : */
311 8 : libpq_options = PQconndefaults();
312 8 : if (!libpq_options) /* assume reason for failure is OOM */
313 0 : ereport(ERROR,
314 : (errcode(ERRCODE_FDW_OUT_OF_MEMORY),
315 : errmsg("out of memory"),
316 : errdetail("Could not get libpq's default connection options.")));
317 :
318 : /* Count how many libpq options are available. */
319 8 : num_libpq_opts = 0;
320 336 : for (lopt = libpq_options; lopt->keyword; lopt++)
321 328 : num_libpq_opts++;
322 :
323 : /*
324 : * Construct an array which consists of all valid options for
325 : * postgres_fdw, by appending FDW-specific options to libpq options.
326 : *
327 : * We use plain malloc here to allocate postgres_fdw_options because it
328 : * lives as long as the backend process does. Besides, keeping
329 : * libpq_options in memory allows us to avoid copying every keyword
330 : * string.
331 : */
332 8 : postgres_fdw_options = (PgFdwOption *)
333 8 : malloc(sizeof(PgFdwOption) * num_libpq_opts +
334 : sizeof(non_libpq_options));
335 8 : if (postgres_fdw_options == NULL)
336 0 : ereport(ERROR,
337 : (errcode(ERRCODE_FDW_OUT_OF_MEMORY),
338 : errmsg("out of memory")));
339 :
340 8 : popt = postgres_fdw_options;
341 336 : for (lopt = libpq_options; lopt->keyword; lopt++)
342 : {
343 : /* Hide debug options, as well as settings we override internally. */
344 328 : if (strchr(lopt->dispchar, 'D') ||
345 320 : strcmp(lopt->keyword, "fallback_application_name") == 0 ||
346 312 : strcmp(lopt->keyword, "client_encoding") == 0)
347 24 : continue;
348 :
349 : /* We don't have to copy keyword string, as described above. */
350 304 : popt->keyword = lopt->keyword;
351 :
352 : /*
353 : * "user" and any secret options are allowed only on user mappings.
354 : * Everything else is a server option.
355 : */
356 304 : if (strcmp(lopt->keyword, "user") == 0 || strchr(lopt->dispchar, '*'))
357 24 : popt->optcontext = UserMappingRelationId;
358 : else
359 280 : popt->optcontext = ForeignServerRelationId;
360 304 : popt->is_libpq_opt = true;
361 :
362 304 : popt++;
363 : }
364 :
365 : /* Append FDW-specific options and dummy terminator. */
366 8 : memcpy(popt, non_libpq_options, sizeof(non_libpq_options));
367 : }
368 :
369 : /*
370 : * Check whether the given option is one of the valid postgres_fdw options.
371 : * context is the Oid of the catalog holding the object the option is for.
372 : */
373 : static bool
374 1216 : is_valid_option(const char *keyword, Oid context)
375 : {
376 : PgFdwOption *opt;
377 :
378 : Assert(postgres_fdw_options); /* must be initialized already */
379 :
380 37880 : for (opt = postgres_fdw_options; opt->keyword; opt++)
381 : {
382 37874 : if (context == opt->optcontext && strcmp(opt->keyword, keyword) == 0)
383 1210 : return true;
384 : }
385 :
386 6 : return false;
387 : }
388 :
389 : /*
390 : * Check whether the given option is one of the valid libpq options.
391 : */
392 : static bool
393 444 : is_libpq_option(const char *keyword)
394 : {
395 : PgFdwOption *opt;
396 :
397 : Assert(postgres_fdw_options); /* must be initialized already */
398 :
399 12120 : for (opt = postgres_fdw_options; opt->keyword; opt++)
400 : {
401 11976 : if (opt->is_libpq_opt && strcmp(opt->keyword, keyword) == 0)
402 300 : return true;
403 : }
404 :
405 144 : return false;
406 : }
407 :
408 : /*
409 : * Generate key-value arrays which include only libpq options from the
410 : * given list (which can contain any kind of options). Caller must have
411 : * allocated large-enough arrays. Returns number of options found.
412 : */
413 : int
414 260 : ExtractConnectionOptions(List *defelems, const char **keywords,
415 : const char **values)
416 : {
417 : ListCell *lc;
418 : int i;
419 :
420 : /* Build our options lists if we didn't yet. */
421 260 : InitPgFdwOptions();
422 :
423 260 : i = 0;
424 704 : foreach(lc, defelems)
425 : {
426 444 : DefElem *d = (DefElem *) lfirst(lc);
427 :
428 444 : if (is_libpq_option(d->defname))
429 : {
430 300 : keywords[i] = d->defname;
431 300 : values[i] = defGetString(d);
432 300 : i++;
433 : }
434 : }
435 260 : return i;
436 : }
437 :
438 : /*
439 : * Parse a comma-separated string and return a List of the OIDs of the
440 : * extensions named in the string. If any names in the list cannot be
441 : * found, report a warning if warnOnMissing is true, else just silently
442 : * ignore them.
443 : */
444 : List *
445 1860 : ExtractExtensionList(const char *extensionsString, bool warnOnMissing)
446 : {
447 1860 : List *extensionOids = NIL;
448 : List *extlist;
449 : ListCell *lc;
450 :
451 : /* SplitIdentifierString scribbles on its input, so pstrdup first */
452 1860 : if (!SplitIdentifierString(pstrdup(extensionsString), ',', &extlist))
453 : {
454 : /* syntax error in name list */
455 2 : ereport(ERROR,
456 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
457 : errmsg("parameter \"%s\" must be a list of extension names",
458 : "extensions")));
459 : }
460 :
461 3718 : foreach(lc, extlist)
462 : {
463 1860 : const char *extension_name = (const char *) lfirst(lc);
464 1860 : Oid extension_oid = get_extension_oid(extension_name, true);
465 :
466 1860 : if (OidIsValid(extension_oid))
467 : {
468 1856 : extensionOids = lappend_oid(extensionOids, extension_oid);
469 : }
470 4 : else if (warnOnMissing)
471 : {
472 4 : ereport(WARNING,
473 : (errcode(ERRCODE_UNDEFINED_OBJECT),
474 : errmsg("extension \"%s\" is not installed",
475 : extension_name)));
476 : }
477 : }
478 :
479 1858 : list_free(extlist);
480 1858 : return extensionOids;
481 : }
482 :
483 : /*
484 : * Replace escape sequences beginning with % character in the given
485 : * application_name with status information, and return it.
486 : *
487 : * This function always returns a palloc'd string, so the caller is
488 : * responsible for pfreeing it.
489 : */
490 : char *
491 32 : process_pgfdw_appname(const char *appname)
492 : {
493 : const char *p;
494 : StringInfoData buf;
495 :
496 32 : initStringInfo(&buf);
497 :
498 442 : for (p = appname; *p != '\0'; p++)
499 : {
500 410 : if (*p != '%')
501 : {
502 : /* literal char, just copy */
503 392 : appendStringInfoChar(&buf, *p);
504 392 : continue;
505 : }
506 :
507 : /* must be a '%', so skip to the next char */
508 18 : p++;
509 18 : if (*p == '\0')
510 0 : break; /* format error - ignore it */
511 18 : else if (*p == '%')
512 : {
513 : /* string contains %% */
514 2 : appendStringInfoChar(&buf, '%');
515 2 : continue;
516 : }
517 :
518 : /* process the option */
519 16 : switch (*p)
520 : {
521 2 : case 'a':
522 2 : appendStringInfoString(&buf, application_name);
523 2 : break;
524 4 : case 'c':
525 4 : appendStringInfo(&buf, "%lx.%x", (long) (MyStartTime), MyProcPid);
526 4 : break;
527 4 : case 'C':
528 4 : appendStringInfoString(&buf, cluster_name);
529 4 : break;
530 2 : case 'd':
531 2 : if (MyProcPort)
532 : {
533 2 : const char *dbname = MyProcPort->database_name;
534 :
535 2 : if (dbname)
536 2 : appendStringInfoString(&buf, dbname);
537 : else
538 0 : appendStringInfoString(&buf, "[unknown]");
539 : }
540 2 : break;
541 2 : case 'p':
542 2 : appendStringInfo(&buf, "%d", MyProcPid);
543 2 : break;
544 2 : case 'u':
545 2 : if (MyProcPort)
546 : {
547 2 : const char *username = MyProcPort->user_name;
548 :
549 2 : if (username)
550 2 : appendStringInfoString(&buf, username);
551 : else
552 0 : appendStringInfoString(&buf, "[unknown]");
553 : }
554 2 : break;
555 0 : default:
556 : /* format error - ignore it */
557 0 : break;
558 : }
559 : }
560 :
561 32 : return buf.data;
562 : }
563 :
564 : /*
565 : * Module load callback
566 : */
567 : void
568 8 : _PG_init(void)
569 : {
570 : /*
571 : * Unlike application_name GUC, don't set GUC_IS_NAME flag nor check_hook
572 : * to allow postgres_fdw.application_name to be any string more than
573 : * NAMEDATALEN characters and to include non-ASCII characters. Instead,
574 : * remote server truncates application_name of remote connection to less
575 : * than NAMEDATALEN and replaces any non-ASCII characters in it with a '?'
576 : * character.
577 : */
578 8 : DefineCustomStringVariable("postgres_fdw.application_name",
579 : "Sets the application name to be used on the remote server.",
580 : NULL,
581 : &pgfdw_application_name,
582 : NULL,
583 : PGC_USERSET,
584 : 0,
585 : NULL,
586 : NULL,
587 : NULL);
588 :
589 8 : MarkGUCPrefixReserved("postgres_fdw");
590 8 : }
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