Get rid of the separate RULE privilege for tables: now only a table's owner

can create or modify rules for the table.  Do setRuleCheckAsUser() while
loading rules into the relcache, rather than when defining a rule.  This
ensures that permission checks for tables referenced in a rule are done with
respect to the current owner of the rule's table, whereas formerly ALTER TABLE
OWNER would fail to update the permission checking for associated rules.
Removal of separate RULE privilege is needed to prevent various scenarios
in which a grantee of RULE privilege could effectively have any privilege
of the table owner.  For backwards compatibility, GRANT/REVOKE RULE is still
accepted, but it doesn't do anything.  Per discussion here:
http://archives.postgresql.org/pgsql-hackers/2006-04/msg01138.php

1 files changed, 27 insertions, 48 deletions

diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c
index a961f49d9b1..17f437c3855 100644
--- a/src/backend/rewrite/rewriteDefine.c
+++ b/src/backend/rewrite/rewriteDefine.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteDefine.c,v 1.113 2006/09/02 17:06:52 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteDefine.c,v 1.114 2006/09/05 21:08:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -33,9 +33,8 @@
 
 static void checkRuleResultList(List *targetList, TupleDesc resultDesc,
 								bool isSelect);
-static void setRuleCheckAsUser_Query(Query *qry, Oid userid);
-static void setRuleCheckAsUser_Expr(Node *node, Oid userid);
 static bool setRuleCheckAsUser_walker(Node *node, Oid *context);
+static void setRuleCheckAsUser_Query(Query *qry, Oid userid);
 
 
 /*
@@ -193,7 +192,6 @@ DefineQueryRewrite(RuleStmt *stmt)
 	int			event_attno;
 	ListCell   *l;
 	Query	   *query;
-	AclResult	aclresult;
 	bool		RelisBecomingView = false;
 
 	/*
@@ -209,9 +207,8 @@ DefineQueryRewrite(RuleStmt *stmt)
 	/*
 	 * Check user has permission to apply rules to this relation.
 	 */
-	aclresult = pg_class_aclcheck(ev_relid, GetUserId(), ACL_RULE);
-	if (aclresult != ACLCHECK_OK)
-		aclcheck_error(aclresult, ACL_KIND_CLASS,
+	if (!pg_class_ownercheck(ev_relid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
 					   RelationGetRelationName(event_relation));
 
 	/*
@@ -411,19 +408,6 @@ DefineQueryRewrite(RuleStmt *stmt)
 	 */
 	event_attno = -1;
 
-	/*
-	 * We want the rule's table references to be checked as though by the rule
-	 * owner, not the user referencing the rule.  Therefore, scan through the
-	 * rule's rtables and set the checkAsUser field on all rtable entries.  We
-	 * have to look at event_qual as well, in case it contains sublinks.
-	 */
-	foreach(l, action)
-	{
-		query = (Query *) lfirst(l);
-		setRuleCheckAsUser_Query(query, GetUserId());
-	}
-	setRuleCheckAsUser_Expr(event_qual, GetUserId());
-
 	/* discard rule if it's null action and not INSTEAD; it's a no-op */
 	if (action != NIL || is_instead)
 	{
@@ -554,9 +538,9 @@ checkRuleResultList(List *targetList, TupleDesc resultDesc, bool isSelect)
 }
 
 /*
- * setRuleCheckAsUser_Query
- *		Recursively scan a query and set the checkAsUser field to the
- *		given userid in all rtable entries.
+ * setRuleCheckAsUser
+ *		Recursively scan a query or expression tree and set the checkAsUser
+ *		field to the given userid in all rtable entries.
  *
  * Note: for a view (ON SELECT rule), the checkAsUser field of the *OLD*
  * RTE entry will be overridden when the view rule is expanded, and the
@@ -565,6 +549,26 @@ checkRuleResultList(List *targetList, TupleDesc resultDesc, bool isSelect)
  * it's important to set these fields to match the rule owner.  So we just set
  * them always.
  */
+void
+setRuleCheckAsUser(Node *node, Oid userid)
+{
+	(void) setRuleCheckAsUser_walker(node, &userid);
+}
+
+static bool
+setRuleCheckAsUser_walker(Node *node, Oid *context)
+{
+	if (node == NULL)
+		return false;
+	if (IsA(node, Query))
+	{
+		setRuleCheckAsUser_Query((Query *) node, *context);
+		return false;
+	}
+	return expression_tree_walker(node, setRuleCheckAsUser_walker,
+								  (void *) context);
+}
+
 static void
 setRuleCheckAsUser_Query(Query *qry, Oid userid)
 {
@@ -591,31 +595,6 @@ setRuleCheckAsUser_Query(Query *qry, Oid userid)
 						  QTW_IGNORE_RT_SUBQUERIES);
 }
 
-/*
- * Expression-tree walker to find sublink queries
- */
-static void
-setRuleCheckAsUser_Expr(Node *node, Oid userid)
-{
-	(void) setRuleCheckAsUser_walker(node, &userid);
-}
-
-static bool
-setRuleCheckAsUser_walker(Node *node, Oid *context)
-{
-	if (node == NULL)
-		return false;
-	if (IsA(node, Query))
-	{
-		Query	   *qry = (Query *) node;
-
-		setRuleCheckAsUser_Query(qry, *context);
-		return false;
-	}
-	return expression_tree_walker(node, setRuleCheckAsUser_walker,
-								  (void *) context);
-}
-
 
 /*
  * Rename an existing rewrite rule.