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1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * rewriteDefine.c
4 : : * routines for defining a rewrite rule
5 : : *
6 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
7 : : * Portions Copyright (c) 1994, Regents of the University of California
8 : : *
9 : : *
10 : : * IDENTIFICATION
11 : : * src/backend/rewrite/rewriteDefine.c
12 : : *
13 : : *-------------------------------------------------------------------------
14 : : */
15 : : #include "postgres.h"
16 : :
17 : : #include "access/htup_details.h"
18 : : #include "access/relation.h"
19 : : #include "access/table.h"
20 : : #include "catalog/catalog.h"
21 : : #include "catalog/dependency.h"
22 : : #include "catalog/indexing.h"
23 : : #include "catalog/namespace.h"
24 : : #include "catalog/objectaccess.h"
25 : : #include "catalog/pg_rewrite.h"
26 : : #include "miscadmin.h"
27 : : #include "nodes/nodeFuncs.h"
28 : : #include "parser/parse_utilcmd.h"
29 : : #include "rewrite/rewriteDefine.h"
30 : : #include "rewrite/rewriteManip.h"
31 : : #include "rewrite/rewriteSupport.h"
32 : : #include "utils/acl.h"
33 : : #include "utils/builtins.h"
34 : : #include "utils/inval.h"
35 : : #include "utils/lsyscache.h"
36 : : #include "utils/rel.h"
37 : : #include "utils/syscache.h"
38 : :
39 : :
40 : : static void checkRuleResultList(List *targetList, TupleDesc resultDesc,
41 : : bool isSelect, bool requireColumnNameMatch);
42 : : static bool setRuleCheckAsUser_walker(Node *node, Oid *context);
43 : : static void setRuleCheckAsUser_Query(Query *qry, Oid userid);
44 : :
45 : :
46 : : /*
47 : : * InsertRule -
48 : : * takes the arguments and inserts them as a row into the system
49 : : * relation "pg_rewrite"
50 : : */
51 : : static Oid
52 : 755 : InsertRule(const char *rulname,
53 : : int evtype,
54 : : Oid eventrel_oid,
55 : : bool evinstead,
56 : : Node *event_qual,
57 : : List *action,
58 : : bool replace)
59 : : {
60 : 755 : char *evqual = nodeToString(event_qual);
61 : 755 : char *actiontree = nodeToString((Node *) action);
62 : 755 : Datum values[Natts_pg_rewrite];
63 : 755 : bool nulls[Natts_pg_rewrite] = {0};
64 : 755 : NameData rname;
65 : 755 : Relation pg_rewrite_desc;
66 : 755 : HeapTuple tup,
67 : : oldtup;
68 : 755 : Oid rewriteObjectId;
69 : 755 : ObjectAddress myself,
70 : : referenced;
71 : 755 : bool is_update = false;
72 : :
73 : : /*
74 : : * Set up *nulls and *values arrays
75 : : */
76 : 755 : namestrcpy(&rname, rulname);
77 : 755 : values[Anum_pg_rewrite_rulename - 1] = NameGetDatum(&rname);
78 : 755 : values[Anum_pg_rewrite_ev_class - 1] = ObjectIdGetDatum(eventrel_oid);
79 : 755 : values[Anum_pg_rewrite_ev_type - 1] = CharGetDatum(evtype + '0');
80 : 755 : values[Anum_pg_rewrite_ev_enabled - 1] = CharGetDatum(RULE_FIRES_ON_ORIGIN);
81 : 755 : values[Anum_pg_rewrite_is_instead - 1] = BoolGetDatum(evinstead);
82 : 755 : values[Anum_pg_rewrite_ev_qual - 1] = CStringGetTextDatum(evqual);
83 : 755 : values[Anum_pg_rewrite_ev_action - 1] = CStringGetTextDatum(actiontree);
84 : :
85 : : /*
86 : : * Ready to store new pg_rewrite tuple
87 : : */
88 : 755 : pg_rewrite_desc = table_open(RewriteRelationId, RowExclusiveLock);
89 : :
90 : : /*
91 : : * Check to see if we are replacing an existing tuple
92 : : */
93 : 755 : oldtup = SearchSysCache2(RULERELNAME,
94 : 755 : ObjectIdGetDatum(eventrel_oid),
95 : 755 : PointerGetDatum(rulname));
96 : :
97 [ + + ]: 755 : if (HeapTupleIsValid(oldtup))
98 : : {
99 : 39 : bool replaces[Natts_pg_rewrite] = {0};
100 : :
101 [ + - ]: 39 : if (!replace)
102 [ # # # # ]: 0 : ereport(ERROR,
103 : : (errcode(ERRCODE_DUPLICATE_OBJECT),
104 : : errmsg("rule \"%s\" for relation \"%s\" already exists",
105 : : rulname, get_rel_name(eventrel_oid))));
106 : :
107 : : /*
108 : : * When replacing, we don't need to replace every attribute
109 : : */
110 : 39 : replaces[Anum_pg_rewrite_ev_type - 1] = true;
111 : 39 : replaces[Anum_pg_rewrite_is_instead - 1] = true;
112 : 39 : replaces[Anum_pg_rewrite_ev_qual - 1] = true;
113 : 39 : replaces[Anum_pg_rewrite_ev_action - 1] = true;
114 : :
115 : 78 : tup = heap_modify_tuple(oldtup, RelationGetDescr(pg_rewrite_desc),
116 : 39 : values, nulls, replaces);
117 : :
118 : 39 : CatalogTupleUpdate(pg_rewrite_desc, &tup->t_self, tup);
119 : :
120 : 39 : ReleaseSysCache(oldtup);
121 : :
122 : 39 : rewriteObjectId = ((Form_pg_rewrite) GETSTRUCT(tup))->oid;
123 : 39 : is_update = true;
124 : 39 : }
125 : : else
126 : : {
127 : 716 : rewriteObjectId = GetNewOidWithIndex(pg_rewrite_desc,
128 : : RewriteOidIndexId,
129 : : Anum_pg_rewrite_oid);
130 : 716 : values[Anum_pg_rewrite_oid - 1] = ObjectIdGetDatum(rewriteObjectId);
131 : :
132 : 716 : tup = heap_form_tuple(pg_rewrite_desc->rd_att, values, nulls);
133 : :
134 : 716 : CatalogTupleInsert(pg_rewrite_desc, tup);
135 : : }
136 : :
137 : :
138 : 755 : heap_freetuple(tup);
139 : :
140 : : /* If replacing, get rid of old dependencies and make new ones */
141 [ + + ]: 755 : if (is_update)
142 : 39 : deleteDependencyRecordsFor(RewriteRelationId, rewriteObjectId, false);
143 : :
144 : : /*
145 : : * Install dependency on rule's relation to ensure it will go away on
146 : : * relation deletion. If the rule is ON SELECT, make the dependency
147 : : * implicit --- this prevents deleting a view's SELECT rule. Other kinds
148 : : * of rules can be AUTO.
149 : : */
150 : 755 : myself.classId = RewriteRelationId;
151 : 755 : myself.objectId = rewriteObjectId;
152 : 755 : myself.objectSubId = 0;
153 : :
154 : 755 : referenced.classId = RelationRelationId;
155 : 755 : referenced.objectId = eventrel_oid;
156 : 755 : referenced.objectSubId = 0;
157 : :
158 : 755 : recordDependencyOn(&myself, &referenced,
159 : 755 : (evtype == CMD_SELECT) ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
160 : :
161 : : /*
162 : : * Also install dependencies on objects referenced in action and qual.
163 : : */
164 : 755 : recordDependencyOnExpr(&myself, (Node *) action, NIL,
165 : : DEPENDENCY_NORMAL);
166 : :
167 [ + + ]: 755 : if (event_qual != NULL)
168 : : {
169 : : /* Find query containing OLD/NEW rtable entries */
170 : 26 : Query *qry = linitial_node(Query, action);
171 : :
172 : 26 : qry = getInsertSelectQuery(qry, NULL);
173 : 26 : recordDependencyOnExpr(&myself, event_qual, qry->rtable,
174 : : DEPENDENCY_NORMAL);
175 : 26 : }
176 : :
177 : : /* Post creation hook for new rule */
178 [ + - ]: 755 : InvokeObjectPostCreateHook(RewriteRelationId, rewriteObjectId, 0);
179 : :
180 : 755 : table_close(pg_rewrite_desc, RowExclusiveLock);
181 : :
182 : 1510 : return rewriteObjectId;
183 : 755 : }
184 : :
185 : : /*
186 : : * DefineRule
187 : : * Execute a CREATE RULE command.
188 : : */
189 : : ObjectAddress
190 : 137 : DefineRule(RuleStmt *stmt, const char *queryString)
191 : : {
192 : 137 : List *actions;
193 : 137 : Node *whereClause;
194 : 137 : Oid relId;
195 : :
196 : : /* Parse analysis. */
197 : 137 : transformRuleStmt(stmt, queryString, &actions, &whereClause);
198 : :
199 : : /*
200 : : * Find and lock the relation. Lock level should match
201 : : * DefineQueryRewrite.
202 : : */
203 : 137 : relId = RangeVarGetRelid(stmt->relation, AccessExclusiveLock, false);
204 : :
205 : : /* ... and execute */
206 : 274 : return DefineQueryRewrite(stmt->rulename,
207 : 137 : relId,
208 : 137 : whereClause,
209 : 137 : stmt->event,
210 : 137 : stmt->instead,
211 : 137 : stmt->replace,
212 : 137 : actions);
213 : 137 : }
214 : :
215 : :
216 : : /*
217 : : * DefineQueryRewrite
218 : : * Create a rule
219 : : *
220 : : * This is essentially the same as DefineRule() except that the rule's
221 : : * action and qual have already been passed through parse analysis.
222 : : */
223 : : ObjectAddress
224 : 760 : DefineQueryRewrite(const char *rulename,
225 : : Oid event_relid,
226 : : Node *event_qual,
227 : : CmdType event_type,
228 : : bool is_instead,
229 : : bool replace,
230 : : List *action)
231 : : {
232 : 760 : Relation event_relation;
233 : 760 : ListCell *l;
234 : 760 : Query *query;
235 : 760 : Oid ruleId = InvalidOid;
236 : : ObjectAddress address;
237 : :
238 : : /*
239 : : * If we are installing an ON SELECT rule, we had better grab
240 : : * AccessExclusiveLock to ensure no SELECTs are currently running on the
241 : : * event relation. For other types of rules, it would be sufficient to
242 : : * grab ShareRowExclusiveLock to lock out insert/update/delete actions and
243 : : * to ensure that we lock out current CREATE RULE statements; but because
244 : : * of race conditions in access to catalog entries, we can't do that yet.
245 : : *
246 : : * Note that this lock level should match the one used in DefineRule.
247 : : */
248 : 760 : event_relation = table_open(event_relid, AccessExclusiveLock);
249 : :
250 : : /*
251 : : * Verify relation is of a type that rules can sensibly be applied to.
252 : : * Internal callers can target materialized views, but transformRuleStmt()
253 : : * blocks them for users. Don't mention them in the error message.
254 : : */
255 [ + + ]: 760 : if (event_relation->rd_rel->relkind != RELKIND_RELATION &&
256 [ + + ]: 671 : event_relation->rd_rel->relkind != RELKIND_MATVIEW &&
257 [ + + + - ]: 621 : event_relation->rd_rel->relkind != RELKIND_VIEW &&
258 : 2 : event_relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
259 [ # # # # ]: 0 : ereport(ERROR,
260 : : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
261 : : errmsg("relation \"%s\" cannot have rules",
262 : : RelationGetRelationName(event_relation)),
263 : : errdetail_relkind_not_supported(event_relation->rd_rel->relkind)));
264 : :
265 [ + + + - ]: 760 : if (!allowSystemTableMods && IsSystemRelation(event_relation))
266 [ # # # # ]: 0 : ereport(ERROR,
267 : : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
268 : : errmsg("permission denied: \"%s\" is a system catalog",
269 : : RelationGetRelationName(event_relation))));
270 : :
271 : : /*
272 : : * Check user has permission to apply rules to this relation.
273 : : */
274 [ + - ]: 760 : if (!object_ownercheck(RelationRelationId, event_relid, GetUserId()))
275 : 0 : aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(event_relation->rd_rel->relkind),
276 : 0 : RelationGetRelationName(event_relation));
277 : :
278 : : /*
279 : : * No rule actions that modify OLD or NEW
280 : : */
281 [ + + + + : 1526 : foreach(l, action)
+ + ]
282 : : {
283 : 766 : query = lfirst_node(Query, l);
284 [ + + ]: 766 : if (query->resultRelation == 0)
285 : 648 : continue;
286 : : /* Don't be fooled by INSERT/SELECT */
287 [ + + ]: 118 : if (query != getInsertSelectQuery(query, NULL))
288 : 9 : continue;
289 [ + - ]: 109 : if (query->resultRelation == PRS2_OLD_VARNO)
290 [ # # # # ]: 0 : ereport(ERROR,
291 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
292 : : errmsg("rule actions on OLD are not implemented"),
293 : : errhint("Use views or triggers instead.")));
294 [ + - ]: 109 : if (query->resultRelation == PRS2_NEW_VARNO)
295 [ # # # # ]: 0 : ereport(ERROR,
296 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
297 : : errmsg("rule actions on NEW are not implemented"),
298 : : errhint("Use triggers instead.")));
299 : 109 : }
300 : :
301 [ + + ]: 758 : if (event_type == CMD_SELECT)
302 : : {
303 : : /*
304 : : * Rules ON SELECT are restricted to view definitions
305 : : *
306 : : * So this had better be a view, ...
307 : : */
308 [ + + + + ]: 628 : if (event_relation->rd_rel->relkind != RELKIND_VIEW &&
309 : 53 : event_relation->rd_rel->relkind != RELKIND_MATVIEW)
310 [ + - + - ]: 3 : ereport(ERROR,
311 : : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
312 : : errmsg("relation \"%s\" cannot have ON SELECT rules",
313 : : RelationGetRelationName(event_relation)),
314 : : errdetail_relkind_not_supported(event_relation->rd_rel->relkind)));
315 : :
316 : : /*
317 : : * ... there cannot be INSTEAD NOTHING, ...
318 : : */
319 [ + - ]: 625 : if (action == NIL)
320 [ # # # # ]: 0 : ereport(ERROR,
321 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
322 : : errmsg("INSTEAD NOTHING rules on SELECT are not implemented"),
323 : : errhint("Use views instead.")));
324 : :
325 : : /*
326 : : * ... there cannot be multiple actions, ...
327 : : */
328 [ + - ]: 625 : if (list_length(action) > 1)
329 [ # # # # ]: 0 : ereport(ERROR,
330 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
331 : : errmsg("multiple actions for rules on SELECT are not implemented")));
332 : :
333 : : /*
334 : : * ... the one action must be a SELECT, ...
335 : : */
336 : 625 : query = linitial_node(Query, action);
337 [ + - ]: 625 : if (!is_instead ||
338 : 625 : query->commandType != CMD_SELECT)
339 [ # # # # ]: 0 : ereport(ERROR,
340 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
341 : : errmsg("rules on SELECT must have action INSTEAD SELECT")));
342 : :
343 : : /*
344 : : * ... it cannot contain data-modifying WITH ...
345 : : */
346 [ + - ]: 625 : if (query->hasModifyingCTE)
347 [ # # # # ]: 0 : ereport(ERROR,
348 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
349 : : errmsg("rules on SELECT must not contain data-modifying statements in WITH")));
350 : :
351 : : /*
352 : : * ... there can be no rule qual, ...
353 : : */
354 [ + - ]: 625 : if (event_qual != NULL)
355 [ # # # # ]: 0 : ereport(ERROR,
356 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
357 : : errmsg("event qualifications are not implemented for rules on SELECT")));
358 : :
359 : : /*
360 : : * ... the targetlist of the SELECT action must exactly match the
361 : : * event relation, ...
362 : : */
363 : 1250 : checkRuleResultList(query->targetList,
364 : 625 : RelationGetDescr(event_relation),
365 : : true,
366 : 625 : event_relation->rd_rel->relkind !=
367 : : RELKIND_MATVIEW);
368 : :
369 : : /*
370 : : * ... there must not be another ON SELECT rule already ...
371 : : */
372 [ + + + - ]: 625 : if (!replace && event_relation->rd_rules != NULL)
373 : : {
374 : 0 : int i;
375 : :
376 [ # # ]: 0 : for (i = 0; i < event_relation->rd_rules->numLocks; i++)
377 : : {
378 : 0 : RewriteRule *rule;
379 : :
380 : 0 : rule = event_relation->rd_rules->rules[i];
381 [ # # ]: 0 : if (rule->event == CMD_SELECT)
382 [ # # # # ]: 0 : ereport(ERROR,
383 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
384 : : errmsg("\"%s\" is already a view",
385 : : RelationGetRelationName(event_relation))));
386 : 0 : }
387 : 0 : }
388 : :
389 : : /*
390 : : * ... and finally the rule must be named _RETURN.
391 : : */
392 [ + - ]: 625 : if (strcmp(rulename, ViewSelectRuleName) != 0)
393 : : {
394 : : /*
395 : : * In versions before 7.3, the expected name was _RETviewname. For
396 : : * backwards compatibility with old pg_dump output, accept that
397 : : * and silently change it to _RETURN. Since this is just a quick
398 : : * backwards-compatibility hack, limit the number of characters
399 : : * checked to a few less than NAMEDATALEN; this saves having to
400 : : * worry about where a multibyte character might have gotten
401 : : * truncated.
402 : : */
403 [ # # ]: 0 : if (strncmp(rulename, "_RET", 4) != 0 ||
404 : 0 : strncmp(rulename + 4, RelationGetRelationName(event_relation),
405 : 0 : NAMEDATALEN - 4 - 4) != 0)
406 [ # # # # ]: 0 : ereport(ERROR,
407 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
408 : : errmsg("view rule for \"%s\" must be named \"%s\"",
409 : : RelationGetRelationName(event_relation),
410 : : ViewSelectRuleName)));
411 : 0 : rulename = pstrdup(ViewSelectRuleName);
412 : 0 : }
413 : 625 : }
414 : : else
415 : : {
416 : : /*
417 : : * For non-SELECT rules, a RETURNING list can appear in at most one of
418 : : * the actions ... and there can't be any RETURNING list at all in a
419 : : * conditional or non-INSTEAD rule. (Actually, there can be at most
420 : : * one RETURNING list across all rules on the same event, but it seems
421 : : * best to enforce that at rule expansion time.) If there is a
422 : : * RETURNING list, it must match the event relation.
423 : : */
424 : 130 : bool haveReturning = false;
425 : :
426 [ + - + + : 268 : foreach(l, action)
+ + ]
427 : : {
428 : 138 : query = lfirst_node(Query, l);
429 : :
430 [ + + ]: 138 : if (!query->returningList)
431 : 117 : continue;
432 [ + - ]: 21 : if (haveReturning)
433 [ # # # # ]: 0 : ereport(ERROR,
434 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
435 : : errmsg("cannot have multiple RETURNING lists in a rule")));
436 : 21 : haveReturning = true;
437 [ + - ]: 21 : if (event_qual != NULL)
438 [ # # # # ]: 0 : ereport(ERROR,
439 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
440 : : errmsg("RETURNING lists are not supported in conditional rules")));
441 [ + - ]: 21 : if (!is_instead)
442 [ # # # # ]: 0 : ereport(ERROR,
443 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
444 : : errmsg("RETURNING lists are not supported in non-INSTEAD rules")));
445 : 42 : checkRuleResultList(query->returningList,
446 : 21 : RelationGetDescr(event_relation),
447 : : false, false);
448 : 21 : }
449 : :
450 : : /*
451 : : * And finally, if it's not an ON SELECT rule then it must *not* be
452 : : * named _RETURN. This prevents accidentally or maliciously replacing
453 : : * a view's ON SELECT rule with some other kind of rule.
454 : : */
455 [ + - ]: 130 : if (strcmp(rulename, ViewSelectRuleName) == 0)
456 [ # # # # ]: 0 : ereport(ERROR,
457 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
458 : : errmsg("non-view rule for \"%s\" must not be named \"%s\"",
459 : : RelationGetRelationName(event_relation),
460 : : ViewSelectRuleName)));
461 : 130 : }
462 : :
463 : : /*
464 : : * This rule is allowed - prepare to install it.
465 : : */
466 : :
467 : : /* discard rule if it's null action and not INSTEAD; it's a no-op */
468 [ - + # # ]: 755 : if (action != NIL || is_instead)
469 : : {
470 : 1510 : ruleId = InsertRule(rulename,
471 : 755 : event_type,
472 : 755 : event_relid,
473 : 755 : is_instead,
474 : 755 : event_qual,
475 : 755 : action,
476 : 755 : replace);
477 : :
478 : : /*
479 : : * Set pg_class 'relhasrules' field true for event relation.
480 : : *
481 : : * Important side effect: an SI notice is broadcast to force all
482 : : * backends (including me!) to update relcache entries with the new
483 : : * rule.
484 : : */
485 : 755 : SetRelationRuleStatus(event_relid, true);
486 : 755 : }
487 : :
488 : 755 : ObjectAddressSet(address, RewriteRelationId, ruleId);
489 : :
490 : : /* Close rel, but keep lock till commit... */
491 : 755 : table_close(event_relation, NoLock);
492 : :
493 : : return address;
494 : 755 : }
495 : :
496 : : /*
497 : : * checkRuleResultList
498 : : * Verify that targetList produces output compatible with a tupledesc
499 : : *
500 : : * The targetList might be either a SELECT targetlist, or a RETURNING list;
501 : : * isSelect tells which. This is used for choosing error messages.
502 : : *
503 : : * A SELECT targetlist may optionally require that column names match.
504 : : */
505 : : static void
506 : 646 : checkRuleResultList(List *targetList, TupleDesc resultDesc, bool isSelect,
507 : : bool requireColumnNameMatch)
508 : : {
509 : 646 : ListCell *tllist;
510 : 646 : int i;
511 : :
512 : : /* Only a SELECT may require a column name match. */
513 [ + + + - ]: 646 : Assert(isSelect || !requireColumnNameMatch);
514 : :
515 : 646 : i = 0;
516 [ + - + + : 3542 : foreach(tllist, targetList)
+ + ]
517 : : {
518 : 2897 : TargetEntry *tle = (TargetEntry *) lfirst(tllist);
519 : 2897 : Oid tletypid;
520 : 2897 : int32 tletypmod;
521 : 2897 : Form_pg_attribute attr;
522 : 2897 : char *attname;
523 : :
524 : : /* resjunk entries may be ignored */
525 [ + + ]: 2897 : if (tle->resjunk)
526 : 16 : continue;
527 : 2881 : i++;
528 [ + + ]: 2881 : if (i > resultDesc->natts)
529 [ + - + - : 1 : ereport(ERROR,
- + ]
530 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
531 : : isSelect ?
532 : : errmsg("SELECT rule's target list has too many entries") :
533 : : errmsg("RETURNING list has too many entries")));
534 : :
535 : 2880 : attr = TupleDescAttr(resultDesc, i - 1);
536 : 2880 : attname = NameStr(attr->attname);
537 : :
538 : : /*
539 : : * Disallow dropped columns in the relation. This is not really
540 : : * expected to happen when creating an ON SELECT rule. It'd be
541 : : * possible if someone tried to convert a relation with dropped
542 : : * columns to a view, but the only case we care about supporting
543 : : * table-to-view conversion for is pg_dump, and pg_dump won't do that.
544 : : *
545 : : * Unfortunately, the situation is also possible when adding a rule
546 : : * with RETURNING to a regular table, and rejecting that case is
547 : : * altogether more annoying. In principle we could support it by
548 : : * modifying the targetlist to include dummy NULL columns
549 : : * corresponding to the dropped columns in the tupdesc. However,
550 : : * places like ruleutils.c would have to be fixed to not process such
551 : : * entries, and that would take an uncertain and possibly rather large
552 : : * amount of work. (Note we could not dodge that by marking the dummy
553 : : * columns resjunk, since it's precisely the non-resjunk tlist columns
554 : : * that are expected to correspond to table columns.)
555 : : */
556 [ + - ]: 2880 : if (attr->attisdropped)
557 [ # # # # : 0 : ereport(ERROR,
# # ]
558 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
559 : : isSelect ?
560 : : errmsg("cannot convert relation containing dropped columns to view") :
561 : : errmsg("cannot create a RETURNING list for a relation containing dropped columns")));
562 : :
563 : : /* Check name match if required; no need for two error texts here */
564 [ + + + - ]: 2880 : if (requireColumnNameMatch && strcmp(tle->resname, attname) != 0)
565 [ # # # # ]: 0 : ereport(ERROR,
566 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
567 : : errmsg("SELECT rule's target entry %d has different column name from column \"%s\"",
568 : : i, attname),
569 : : errdetail("SELECT target entry is named \"%s\".",
570 : : tle->resname)));
571 : :
572 : : /* Check type match. */
573 : 2880 : tletypid = exprType((Node *) tle->expr);
574 [ + - ]: 2880 : if (attr->atttypid != tletypid)
575 [ # # # # : 0 : ereport(ERROR,
# # # # ]
576 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
577 : : isSelect ?
578 : : errmsg("SELECT rule's target entry %d has different type from column \"%s\"",
579 : : i, attname) :
580 : : errmsg("RETURNING list's entry %d has different type from column \"%s\"",
581 : : i, attname),
582 : : isSelect ?
583 : : errdetail("SELECT target entry has type %s, but column has type %s.",
584 : : format_type_be(tletypid),
585 : : format_type_be(attr->atttypid)) :
586 : : errdetail("RETURNING list entry has type %s, but column has type %s.",
587 : : format_type_be(tletypid),
588 : : format_type_be(attr->atttypid))));
589 : :
590 : : /*
591 : : * Allow typmods to be different only if one of them is -1, ie,
592 : : * "unspecified". This is necessary for cases like "numeric", where
593 : : * the table will have a filled-in default length but the select
594 : : * rule's expression will probably have typmod = -1.
595 : : */
596 : 2880 : tletypmod = exprTypmod((Node *) tle->expr);
597 [ - + ]: 2880 : if (attr->atttypmod != tletypmod &&
598 [ # # # # ]: 0 : attr->atttypmod != -1 && tletypmod != -1)
599 [ # # # # : 0 : ereport(ERROR,
# # # # ]
600 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
601 : : isSelect ?
602 : : errmsg("SELECT rule's target entry %d has different size from column \"%s\"",
603 : : i, attname) :
604 : : errmsg("RETURNING list's entry %d has different size from column \"%s\"",
605 : : i, attname),
606 : : isSelect ?
607 : : errdetail("SELECT target entry has type %s, but column has type %s.",
608 : : format_type_with_typemod(tletypid, tletypmod),
609 : : format_type_with_typemod(attr->atttypid,
610 : : attr->atttypmod)) :
611 : : errdetail("RETURNING list entry has type %s, but column has type %s.",
612 : : format_type_with_typemod(tletypid, tletypmod),
613 : : format_type_with_typemod(attr->atttypid,
614 : : attr->atttypmod))));
615 [ - + + ]: 2896 : }
616 : :
617 [ + - ]: 645 : if (i != resultDesc->natts)
618 [ # # # # : 0 : ereport(ERROR,
# # ]
619 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
620 : : isSelect ?
621 : : errmsg("SELECT rule's target list has too few entries") :
622 : : errmsg("RETURNING list has too few entries")));
623 : 645 : }
624 : :
625 : : /*
626 : : * setRuleCheckAsUser
627 : : * Recursively scan a query or expression tree and set the checkAsUser
628 : : * field to the given userid in all RTEPermissionInfos of the query.
629 : : */
630 : : void
631 : 5440 : setRuleCheckAsUser(Node *node, Oid userid)
632 : : {
633 : 5440 : (void) setRuleCheckAsUser_walker(node, &userid);
634 : 5440 : }
635 : :
636 : : static bool
637 : 22213 : setRuleCheckAsUser_walker(Node *node, Oid *context)
638 : : {
639 [ + + ]: 22213 : if (node == NULL)
640 : 4908 : return false;
641 [ + + ]: 17305 : if (IsA(node, Query))
642 : : {
643 : 2607 : setRuleCheckAsUser_Query((Query *) node, *context);
644 : 2607 : return false;
645 : : }
646 : 14698 : return expression_tree_walker(node, setRuleCheckAsUser_walker,
647 : : context);
648 : 22213 : }
649 : :
650 : : static void
651 : 3035 : setRuleCheckAsUser_Query(Query *qry, Oid userid)
652 : : {
653 : 3035 : ListCell *l;
654 : :
655 : : /* Set in all RTEPermissionInfos for this query. */
656 [ + + + + : 6654 : foreach(l, qry->rteperminfos)
+ + ]
657 : : {
658 : 3619 : RTEPermissionInfo *perminfo = lfirst_node(RTEPermissionInfo, l);
659 : :
660 : 3619 : perminfo->checkAsUser = userid;
661 : 3619 : }
662 : :
663 : : /* Now recurse to any subquery RTEs */
664 [ + + + + : 8259 : foreach(l, qry->rtable)
+ + ]
665 : : {
666 : 5224 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
667 : :
668 [ + + ]: 5224 : if (rte->rtekind == RTE_SUBQUERY)
669 : 399 : setRuleCheckAsUser_Query(rte->subquery, userid);
670 : 5224 : }
671 : :
672 : : /* Recurse into subquery-in-WITH */
673 [ + + + + : 3064 : foreach(l, qry->cteList)
+ + ]
674 : : {
675 : 29 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(l);
676 : :
677 : 29 : setRuleCheckAsUser_Query(castNode(Query, cte->ctequery), userid);
678 : 29 : }
679 : :
680 : : /* If there are sublinks, search for them and process their RTEs */
681 [ + + ]: 3035 : if (qry->hasSubLinks)
682 : 144 : query_tree_walker(qry, setRuleCheckAsUser_walker, &userid,
683 : : QTW_IGNORE_RC_SUBQUERIES);
684 : 3035 : }
685 : :
686 : :
687 : : /*
688 : : * Change the firing semantics of an existing rule.
689 : : */
690 : : void
691 : 6 : EnableDisableRule(Relation rel, const char *rulename,
692 : : char fires_when)
693 : : {
694 : 6 : Relation pg_rewrite_desc;
695 : 6 : Oid owningRel = RelationGetRelid(rel);
696 : 6 : Oid eventRelationOid;
697 : 6 : HeapTuple ruletup;
698 : 6 : Form_pg_rewrite ruleform;
699 : 6 : bool changed = false;
700 : :
701 : : /*
702 : : * Find the rule tuple to change.
703 : : */
704 : 6 : pg_rewrite_desc = table_open(RewriteRelationId, RowExclusiveLock);
705 : 6 : ruletup = SearchSysCacheCopy2(RULERELNAME,
706 : : ObjectIdGetDatum(owningRel),
707 : : PointerGetDatum(rulename));
708 [ + - ]: 6 : if (!HeapTupleIsValid(ruletup))
709 [ # # # # ]: 0 : ereport(ERROR,
710 : : (errcode(ERRCODE_UNDEFINED_OBJECT),
711 : : errmsg("rule \"%s\" for relation \"%s\" does not exist",
712 : : rulename, get_rel_name(owningRel))));
713 : :
714 : 6 : ruleform = (Form_pg_rewrite) GETSTRUCT(ruletup);
715 : :
716 : : /*
717 : : * Verify that the user has appropriate permissions.
718 : : */
719 : 6 : eventRelationOid = ruleform->ev_class;
720 [ + - ]: 6 : Assert(eventRelationOid == owningRel);
721 [ + - ]: 6 : if (!object_ownercheck(RelationRelationId, eventRelationOid, GetUserId()))
722 : 0 : aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(eventRelationOid)),
723 : 0 : get_rel_name(eventRelationOid));
724 : :
725 : : /*
726 : : * Change ev_enabled if it is different from the desired new state.
727 : : */
728 [ - + ]: 6 : if (ruleform->ev_enabled != fires_when)
729 : : {
730 : 6 : ruleform->ev_enabled = fires_when;
731 : 6 : CatalogTupleUpdate(pg_rewrite_desc, &ruletup->t_self, ruletup);
732 : :
733 : 6 : changed = true;
734 : 6 : }
735 : :
736 [ + - ]: 6 : InvokeObjectPostAlterHook(RewriteRelationId, ruleform->oid, 0);
737 : :
738 : 6 : heap_freetuple(ruletup);
739 : 6 : table_close(pg_rewrite_desc, RowExclusiveLock);
740 : :
741 : : /*
742 : : * If we changed anything, broadcast a SI inval message to force each
743 : : * backend (including our own!) to rebuild relation's relcache entry.
744 : : * Otherwise they will fail to apply the change promptly.
745 : : */
746 [ - + ]: 6 : if (changed)
747 : 6 : CacheInvalidateRelcache(rel);
748 : 6 : }
749 : :
750 : :
751 : : /*
752 : : * Perform permissions and integrity checks before acquiring a relation lock.
753 : : */
754 : : static void
755 : 5 : RangeVarCallbackForRenameRule(const RangeVar *rv, Oid relid, Oid oldrelid,
756 : : void *arg)
757 : : {
758 : 5 : HeapTuple tuple;
759 : 5 : Form_pg_class form;
760 : :
761 : 5 : tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
762 [ + - ]: 5 : if (!HeapTupleIsValid(tuple))
763 : 0 : return; /* concurrently dropped */
764 : 5 : form = (Form_pg_class) GETSTRUCT(tuple);
765 : :
766 : : /* only tables and views can have rules */
767 [ + - ]: 5 : if (form->relkind != RELKIND_RELATION &&
768 [ + + + - ]: 5 : form->relkind != RELKIND_VIEW &&
769 : 1 : form->relkind != RELKIND_PARTITIONED_TABLE)
770 [ # # # # ]: 0 : ereport(ERROR,
771 : : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
772 : : errmsg("relation \"%s\" cannot have rules", rv->relname),
773 : : errdetail_relkind_not_supported(form->relkind)));
774 : :
775 [ + - + - ]: 5 : if (!allowSystemTableMods && IsSystemClass(relid, form))
776 [ # # # # ]: 0 : ereport(ERROR,
777 : : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
778 : : errmsg("permission denied: \"%s\" is a system catalog",
779 : : rv->relname)));
780 : :
781 : : /* you must own the table to rename one of its rules */
782 [ + - ]: 5 : if (!object_ownercheck(RelationRelationId, relid, GetUserId()))
783 : 0 : aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relid)), rv->relname);
784 : :
785 : 5 : ReleaseSysCache(tuple);
786 [ - + ]: 5 : }
787 : :
788 : : /*
789 : : * Rename an existing rewrite rule.
790 : : */
791 : : ObjectAddress
792 : 5 : RenameRewriteRule(RangeVar *relation, const char *oldName,
793 : : const char *newName)
794 : : {
795 : 5 : Oid relid;
796 : 5 : Relation targetrel;
797 : 5 : Relation pg_rewrite_desc;
798 : 5 : HeapTuple ruletup;
799 : 5 : Form_pg_rewrite ruleform;
800 : 5 : Oid ruleOid;
801 : : ObjectAddress address;
802 : :
803 : : /*
804 : : * Look up name, check permissions, and acquire lock (which we will NOT
805 : : * release until end of transaction).
806 : : */
807 : 5 : relid = RangeVarGetRelidExtended(relation, AccessExclusiveLock,
808 : : 0,
809 : : RangeVarCallbackForRenameRule,
810 : : NULL);
811 : :
812 : : /* Have lock already, so just need to build relcache entry. */
813 : 5 : targetrel = relation_open(relid, NoLock);
814 : :
815 : : /* Prepare to modify pg_rewrite */
816 : 5 : pg_rewrite_desc = table_open(RewriteRelationId, RowExclusiveLock);
817 : :
818 : : /* Fetch the rule's entry (it had better exist) */
819 : 5 : ruletup = SearchSysCacheCopy2(RULERELNAME,
820 : : ObjectIdGetDatum(relid),
821 : : PointerGetDatum(oldName));
822 [ + + ]: 5 : if (!HeapTupleIsValid(ruletup))
823 [ + - + - ]: 1 : ereport(ERROR,
824 : : (errcode(ERRCODE_UNDEFINED_OBJECT),
825 : : errmsg("rule \"%s\" for relation \"%s\" does not exist",
826 : : oldName, RelationGetRelationName(targetrel))));
827 : 4 : ruleform = (Form_pg_rewrite) GETSTRUCT(ruletup);
828 : 4 : ruleOid = ruleform->oid;
829 : :
830 : : /* rule with the new name should not already exist */
831 [ + + ]: 4 : if (IsDefinedRewriteRule(relid, newName))
832 [ + - + - ]: 1 : ereport(ERROR,
833 : : (errcode(ERRCODE_DUPLICATE_OBJECT),
834 : : errmsg("rule \"%s\" for relation \"%s\" already exists",
835 : : newName, RelationGetRelationName(targetrel))));
836 : :
837 : : /*
838 : : * We disallow renaming ON SELECT rules, because they should always be
839 : : * named "_RETURN".
840 : : */
841 [ + + ]: 3 : if (ruleform->ev_type == CMD_SELECT + '0')
842 [ + - + - ]: 1 : ereport(ERROR,
843 : : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
844 : : errmsg("renaming an ON SELECT rule is not allowed")));
845 : :
846 : : /* OK, do the update */
847 : 2 : namestrcpy(&(ruleform->rulename), newName);
848 : :
849 : 2 : CatalogTupleUpdate(pg_rewrite_desc, &ruletup->t_self, ruletup);
850 : :
851 [ + - ]: 2 : InvokeObjectPostAlterHook(RewriteRelationId, ruleOid, 0);
852 : :
853 : 2 : heap_freetuple(ruletup);
854 : 2 : table_close(pg_rewrite_desc, RowExclusiveLock);
855 : :
856 : : /*
857 : : * Invalidate relation's relcache entry so that other backends (and this
858 : : * one too!) are sent SI message to make them rebuild relcache entries.
859 : : * (Ideally this should happen automatically...)
860 : : */
861 : 2 : CacheInvalidateRelcache(targetrel);
862 : :
863 : 2 : ObjectAddressSet(address, RewriteRelationId, ruleOid);
864 : :
865 : : /*
866 : : * Close rel, but keep exclusive lock!
867 : : */
868 : 2 : relation_close(targetrel, NoLock);
869 : :
870 : : return address;
871 : 2 : }
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