Centralize code for interpreting schema references, which had gotten

copied more places than I first thought it would.  This fixes a bug:
a couple of these places were neglecting to enforce USAGE access on
explicitly-referenced schemas.

src/backend/catalog/namespace.c

@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.26 2002/07/20 05:16:56 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.27 2002/07/29 23:46:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -164,18 +164,7 @@ RangeVarGetRelid(const RangeVar *relation, bool failOK)
 	if (relation->schemaname)
 	{
 		/* use exact schema given */
-		AclResult	aclresult;
-
-		namespaceId = GetSysCacheOid(NAMESPACENAME,
-									 CStringGetDatum(relation->schemaname),
-									 0, 0, 0);
-		if (!OidIsValid(namespaceId))
-			elog(ERROR, "Namespace \"%s\" does not exist",
-				 relation->schemaname);
-		aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE);
-		if (aclresult != ACLCHECK_OK)
-			aclcheck_error(aclresult, relation->schemaname);
-
+		namespaceId = LookupExplicitNamespace(relation->schemaname);
 		relId = get_relname_relid(relation->relname, namespaceId);
 	}
 	else
@@ -239,6 +228,7 @@ RangeVarGetCreationNamespace(const RangeVar *newRelation)
 		if (!OidIsValid(namespaceId))
 			elog(ERROR, "Namespace \"%s\" does not exist",
 				 newRelation->schemaname);
+		/* we do not check for USAGE rights here! */
 	}
 	else
 	{
@@ -431,53 +421,19 @@ FuncCandidateList
 FuncnameGetCandidates(List *names, int nargs)
 {
 	FuncCandidateList resultList = NULL;
-	char	   *catalogname;
-	char	   *schemaname = NULL;
-	char	   *funcname = NULL;
+	char	   *schemaname;
+	char	   *funcname;
 	Oid			namespaceId;
 	CatCList   *catlist;
 	int			i;
 
 	/* deconstruct the name list */
-	switch (length(names))
-	{
-		case 1:
-			funcname = strVal(lfirst(names));
-			break;
-		case 2:
-			schemaname = strVal(lfirst(names));
-			funcname = strVal(lsecond(names));
-			break;
-		case 3:
-			catalogname = strVal(lfirst(names));
-			schemaname = strVal(lsecond(names));
-			funcname = strVal(lfirst(lnext(lnext(names))));
-			/*
-			 * We check the catalog name and then ignore it.
-			 */
-			if (strcmp(catalogname, DatabaseName) != 0)
-				elog(ERROR, "Cross-database references are not implemented");
-			break;
-		default:
-			elog(ERROR, "Improper qualified name (too many dotted names): %s",
-				 NameListToString(names));
-			break;
-	}
+	DeconstructQualifiedName(names, &schemaname, &funcname);
 
 	if (schemaname)
 	{
 		/* use exact schema given */
-		AclResult	aclresult;
-
-		namespaceId = GetSysCacheOid(NAMESPACENAME,
-									 CStringGetDatum(schemaname),
-									 0, 0, 0);
-		if (!OidIsValid(namespaceId))
-			elog(ERROR, "Namespace \"%s\" does not exist",
-				 schemaname);
-		aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE);
-		if (aclresult != ACLCHECK_OK)
-			aclcheck_error(aclresult, schemaname);
+		namespaceId = LookupExplicitNamespace(schemaname);
 	}
 	else
 	{
@@ -684,53 +640,19 @@ FuncCandidateList
 OpernameGetCandidates(List *names, char oprkind)
 {
 	FuncCandidateList resultList = NULL;
-	char	   *catalogname;
-	char	   *schemaname = NULL;
-	char	   *opername = NULL;
+	char	   *schemaname;
+	char	   *opername;
 	Oid			namespaceId;
 	CatCList   *catlist;
 	int			i;
 
 	/* deconstruct the name list */
-	switch (length(names))
-	{
-		case 1:
-			opername = strVal(lfirst(names));
-			break;
-		case 2:
-			schemaname = strVal(lfirst(names));
-			opername = strVal(lsecond(names));
-			break;
-		case 3:
-			catalogname = strVal(lfirst(names));
-			schemaname = strVal(lsecond(names));
-			opername = strVal(lfirst(lnext(lnext(names))));
-			/*
-			 * We check the catalog name and then ignore it.
-			 */
-			if (strcmp(catalogname, DatabaseName) != 0)
-				elog(ERROR, "Cross-database references are not implemented");
-			break;
-		default:
-			elog(ERROR, "Improper qualified name (too many dotted names): %s",
-				 NameListToString(names));
-			break;
-	}
+	DeconstructQualifiedName(names, &schemaname, &opername);
 
 	if (schemaname)
 	{
 		/* use exact schema given */
-		AclResult	aclresult;
-
-		namespaceId = GetSysCacheOid(NAMESPACENAME,
-									 CStringGetDatum(schemaname),
-									 0, 0, 0);
-		if (!OidIsValid(namespaceId))
-			elog(ERROR, "Namespace \"%s\" does not exist",
-				 schemaname);
-		aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE);
-		if (aclresult != ACLCHECK_OK)
-			aclcheck_error(aclresult, schemaname);
+		namespaceId = LookupExplicitNamespace(schemaname);
 	}
 	else
 	{
@@ -1105,25 +1027,22 @@ OpclassIsVisible(Oid opcid)
 	return visible;
 }
 
-
 /*
- * QualifiedNameGetCreationNamespace
- *		Given a possibly-qualified name for an object (in List-of-Values
- *		format), determine what namespace the object should be created in.
- *		Also extract and return the object name (last component of list).
+ * DeconstructQualifiedName
+ *		Given a possibly-qualified name expressed as a list of String nodes,
+ *		extract the schema name and object name.
  *
- * This is *not* used for tables.  Hence, the TEMP table namespace is
- * never selected as the creation target.
+ * *nspname_p is set to NULL if there is no explicit schema name.
  */
-Oid
-QualifiedNameGetCreationNamespace(List *names, char **objname_p)
+void
+DeconstructQualifiedName(List *names,
+						 char **nspname_p,
+						 char **objname_p)
 {
 	char	   *catalogname;
 	char	   *schemaname = NULL;
 	char	   *objname = NULL;
-	Oid			namespaceId;
 
-	/* deconstruct the name list */
 	switch (length(names))
 	{
 		case 1:
@@ -1149,6 +1068,55 @@ QualifiedNameGetCreationNamespace(List *names, char **objname_p)
 			break;
 	}
 
+	*nspname_p = schemaname;
+	*objname_p = objname;
+}
+
+/*
+ * LookupExplicitNamespace
+ *		Process an explicitly-specified schema name: look up the schema
+ *		and verify we have USAGE (lookup) rights in it.
+ *
+ * Returns the namespace OID.  Raises elog if any problem.
+ */
+Oid
+LookupExplicitNamespace(char *nspname)
+{
+	Oid			namespaceId;
+	AclResult	aclresult;
+
+	namespaceId = GetSysCacheOid(NAMESPACENAME,
+								 CStringGetDatum(nspname),
+								 0, 0, 0);
+	if (!OidIsValid(namespaceId))
+		elog(ERROR, "Namespace \"%s\" does not exist", nspname);
+
+	aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, nspname);
+
+	return namespaceId;
+}
+
+/*
+ * QualifiedNameGetCreationNamespace
+ *		Given a possibly-qualified name for an object (in List-of-Values
+ *		format), determine what namespace the object should be created in.
+ *		Also extract and return the object name (last component of list).
+ *
+ * This is *not* used for tables.  Hence, the TEMP table namespace is
+ * never selected as the creation target.
+ */
+Oid
+QualifiedNameGetCreationNamespace(List *names, char **objname_p)
+{
+	char	   *schemaname;
+	char	   *objname;
+	Oid			namespaceId;
+
+	/* deconstruct the name list */
+	DeconstructQualifiedName(names, &schemaname, &objname);
+
 	if (schemaname)
 	{
 		/* use exact schema given */
@@ -1158,6 +1126,7 @@ QualifiedNameGetCreationNamespace(List *names, char **objname_p)
 		if (!OidIsValid(namespaceId))
 			elog(ERROR, "Namespace \"%s\" does not exist",
 				 schemaname);
+		/* we do not check for USAGE rights here! */
 	}
 	else
 	{

src/backend/commands/comment.c

@@ -7,7 +7,7 @@
  * Copyright (c) 1996-2001, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.52 2002/07/20 05:16:57 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.53 2002/07/29 23:46:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,7 +22,6 @@
 #include "catalog/pg_constraint.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_description.h"
-#include "catalog/pg_namespace.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_rewrite.h"
 #include "catalog/pg_trigger.h"
@@ -468,36 +467,28 @@ CommentNamespace(List *qualname, char *comment)
 {
 	Oid			oid;
 	Oid			classoid;
-	HeapTuple	tp;
 	char	   *namespace;
 
 	if (length(qualname) != 1)
 		elog(ERROR, "CommentSchema: schema name may not be qualified");
 	namespace = strVal(lfirst(qualname));
 
-	tp = SearchSysCache(NAMESPACENAME,
-						CStringGetDatum(namespace),
-						0, 0, 0);
-	if (!HeapTupleIsValid(tp))
+	oid = GetSysCacheOid(NAMESPACENAME,
+						 CStringGetDatum(namespace),
+						 0, 0, 0);
+	if (!OidIsValid(oid))
 		elog(ERROR, "CommentSchema: Schema \"%s\" could not be found",
 			 namespace);
 
-	/* no TupleDesc here to Assert(...->tdhasoid); */
-	oid = HeapTupleGetOid(tp);
-
 	/* Check object security */
 	if (!pg_namespace_ownercheck(oid, GetUserId()))
 		aclcheck_error(ACLCHECK_NOT_OWNER, namespace);
 
 	/* pg_namespace doesn't have a hard-coded OID, so must look it up */
-	classoid = get_relname_relid(NamespaceRelationName, PG_CATALOG_NAMESPACE);
-	Assert(OidIsValid(classoid));
+	classoid = get_system_catalog_relid(NamespaceRelationName);
 
 	/* Call CreateComments() to create/drop the comments */
 	CreateComments(oid, classoid, 0, comment);
-
-	/* Cleanup */
-	ReleaseSysCache(tp);
 }
 
 /*
@@ -607,8 +598,7 @@ CommentRule(List *qualname, char *comment)
 		aclcheck_error(aclcheck, rulename);
 
 	/* pg_rewrite doesn't have a hard-coded OID, so must look it up */
-	classoid = get_relname_relid(RewriteRelationName, PG_CATALOG_NAMESPACE);
-	Assert(OidIsValid(classoid));
+	classoid = get_system_catalog_relid(RewriteRelationName);
 
 	/* Call CreateComments() to create/drop the comments */
 
@@ -740,8 +730,7 @@ CommentOperator(List *opername, List *arguments, char *comment)
 		aclcheck_error(ACLCHECK_NOT_OWNER, NameListToString(opername));
 
 	/* pg_operator doesn't have a hard-coded OID, so must look it up */
-	classoid = get_relname_relid(OperatorRelationName, PG_CATALOG_NAMESPACE);
-	Assert(OidIsValid(classoid));
+	classoid = get_system_catalog_relid(OperatorRelationName);
 
 	/* Call CreateComments() to create/drop the comments */
 	CreateComments(oid, classoid, 0, comment);

src/backend/commands/indexcmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.78 2002/07/20 05:16:57 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.79 2002/07/29 23:46:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -410,9 +410,8 @@ static Oid
 GetAttrOpClass(IndexElem *attribute, Oid attrType,
 			   char *accessMethodName, Oid accessMethodId)
 {
-	char	   *catalogname;
-	char	   *schemaname = NULL;
-	char	   *opcname = NULL;
+	char	   *schemaname;
+	char	   *opcname;
 	HeapTuple	tuple;
 	Oid			opClassId,
 				opInputType;
@@ -434,42 +433,14 @@ GetAttrOpClass(IndexElem *attribute, Oid attrType,
 	 */
 
 	/* deconstruct the name list */
-	switch (length(attribute->opclass))
-	{
-		case 1:
-			opcname = strVal(lfirst(attribute->opclass));
-			break;
-		case 2:
-			schemaname = strVal(lfirst(attribute->opclass));
-			opcname = strVal(lsecond(attribute->opclass));
-			break;
-		case 3:
-			catalogname = strVal(lfirst(attribute->opclass));
-			schemaname = strVal(lsecond(attribute->opclass));
-			opcname = strVal(lfirst(lnext(lnext(attribute->opclass))));
-			/*
-			 * We check the catalog name and then ignore it.
-			 */
-			if (strcmp(catalogname, DatabaseName) != 0)
-				elog(ERROR, "Cross-database references are not implemented");
-			break;
-		default:
-			elog(ERROR, "Improper opclass name (too many dotted names): %s",
-				 NameListToString(attribute->opclass));
-			break;
-	}
+	DeconstructQualifiedName(attribute->opclass, &schemaname, &opcname);
 
 	if (schemaname)
 	{
 		/* Look in specific schema only */
 		Oid		namespaceId;
 
-		namespaceId = GetSysCacheOid(NAMESPACENAME,
-									 CStringGetDatum(schemaname),
-									 0, 0, 0);
-		if (!OidIsValid(namespaceId))
-			elog(ERROR, "Namespace \"%s\" does not exist",
-				 schemaname);
+		namespaceId = LookupExplicitNamespace(schemaname);
 		tuple = SearchSysCache(CLAAMNAMENSP,
 							   ObjectIdGetDatum(accessMethodId),
 							   PointerGetDatum(opcname),

src/backend/commands/opclasscmds.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/opclasscmds.c,v 1.1 2002/07/29 22:14:10 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/opclasscmds.c,v 1.2 2002/07/29 23:46:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -467,10 +467,9 @@ storeProcedures(Oid opclassoid, int numProcs, Oid *procedures)
 void
 RemoveOpClass(RemoveOpClassStmt *stmt)
 {
-	Oid				amID, opcID;
-	char	   *catalogname;
-	char	   *schemaname = NULL;
-	char	   *opcname = NULL;
+	Oid			amID, opcID;
+	char	   *schemaname;
+	char	   *opcname;
 	HeapTuple	tuple;
 	ObjectAddress object;
 
@@ -489,42 +488,14 @@ RemoveOpClass(RemoveOpClassStmt *stmt)
 	 */
 
 	/* deconstruct the name list */
-	switch (length(stmt->opclassname))
-	{
-		case 1:
-			opcname = strVal(lfirst(stmt->opclassname));
-			break;
-		case 2:
-			schemaname = strVal(lfirst(stmt->opclassname));
-			opcname = strVal(lsecond(stmt->opclassname));
-			break;
-		case 3:
-			catalogname = strVal(lfirst(stmt->opclassname));
-			schemaname = strVal(lsecond(stmt->opclassname));
-			opcname = strVal(lfirst(lnext(lnext(stmt->opclassname))));
-			/*
-			 * We check the catalog name and then ignore it.
-			 */
-			if (strcmp(catalogname, DatabaseName) != 0)
-				elog(ERROR, "Cross-database references are not implemented");
-			break;
-		default:
-			elog(ERROR, "Improper opclass name (too many dotted names): %s",
-				 NameListToString(stmt->opclassname));
-			break;
-	}
+	DeconstructQualifiedName(stmt->opclassname, &schemaname, &opcname);
 
 	if (schemaname)
 	{
 		/* Look in specific schema only */
 		Oid		namespaceId;
 
-		namespaceId = GetSysCacheOid(NAMESPACENAME,
-									 CStringGetDatum(schemaname),
-									 0, 0, 0);
-		if (!OidIsValid(namespaceId))
-			elog(ERROR, "Namespace \"%s\" does not exist",
-				 schemaname);
+		namespaceId = LookupExplicitNamespace(schemaname);
 		tuple = SearchSysCache(CLAAMNAMENSP,
 							   ObjectIdGetDatum(amID),
 							   PointerGetDatum(opcname),

src/backend/parser/parse_type.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_type.c,v 1.45 2002/07/20 05:16:58 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_type.c,v 1.46 2002/07/29 23:46:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -99,35 +99,11 @@ LookupTypeName(const TypeName *typename)
 	else
 	{
 		/* Normal reference to a type name */
-		char	   *catalogname;
-		char	   *schemaname = NULL;
-		char	   *typname = NULL;
+		char	   *schemaname;
+		char	   *typname;
 
 		/* deconstruct the name list */
-		switch (length(typename->names))
-		{
-			case 1:
-				typname = strVal(lfirst(typename->names));
-				break;
-			case 2:
-				schemaname = strVal(lfirst(typename->names));
-				typname = strVal(lsecond(typename->names));
-				break;
-			case 3:
-				catalogname = strVal(lfirst(typename->names));
-				schemaname = strVal(lsecond(typename->names));
-				typname = strVal(lfirst(lnext(lnext(typename->names))));
-				/*
-				 * We check the catalog name and then ignore it.
-				 */
-				if (strcmp(catalogname, DatabaseName) != 0)
-					elog(ERROR, "Cross-database references are not implemented");
-				break;
-			default:
-				elog(ERROR, "Improper type name (too many dotted names): %s",
-					 NameListToString(typename->names));
-				break;
-		}
+		DeconstructQualifiedName(typename->names, &schemaname, &typname);
 
 		/* If an array reference, look up the array type instead */
 		if (typename->arrayBounds != NIL)
@@ -138,12 +114,7 @@ LookupTypeName(const TypeName *typename)
 			/* Look in specific schema only */
 			Oid		namespaceId;
 
-			namespaceId = GetSysCacheOid(NAMESPACENAME,
-										 CStringGetDatum(schemaname),
-										 0, 0, 0);
-			if (!OidIsValid(namespaceId))
-				elog(ERROR, "Namespace \"%s\" does not exist",
-					 schemaname);
+			namespaceId = LookupExplicitNamespace(schemaname);
 			restype = GetSysCacheOid(TYPENAMENSP,
 									 PointerGetDatum(typname),
 									 ObjectIdGetDatum(namespaceId),

src/include/catalog/namespace.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: namespace.h,v 1.16 2002/07/16 06:58:13 ishii Exp $
+ * $Id: namespace.h,v 1.17 2002/07/29 23:46:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -66,6 +66,11 @@ extern OpclassCandidateList OpclassGetCandidates(Oid amid);
 extern Oid	OpclassnameGetOpcid(Oid amid, const char *opcname);
 extern bool OpclassIsVisible(Oid opcid);
 
+extern void DeconstructQualifiedName(List *names,
+									 char **nspname_p,
+									 char **objname_p);
+extern Oid	LookupExplicitNamespace(char *nspname);
+
 extern Oid	QualifiedNameGetCreationNamespace(List *names, char **objname_p);
 extern RangeVar *makeRangeVarFromNameList(List *names);
 extern char *NameListToString(List *names);