Fix permissions-checking bugs and namespace-search-path bugs in

CONVERSION code.  Still need to figure out what to do about inappropriate
coding in parsing.

doc/src/sgml/ref/create_conversion.sgml

-<!-- $Header: /cvsroot/pgsql/doc/src/sgml/ref/create_conversion.sgml,v 1.4 2002/09/21 18:32:54 petere Exp $ -->
+<!-- $Header: /cvsroot/pgsql/doc/src/sgml/ref/create_conversion.sgml,v 1.5 2002/11/02 02:33:03 tgl Exp $ -->
 
 <refentry id="SQL-CREATECONVERSION">
  <refmeta>
@@ -14,8 +14,7 @@
  <refsynopsisdiv>
 <synopsis>
 CREATE [DEFAULT] CONVERSION <replaceable>conversion_name</replaceable>
-    FOR <replaceable>source_encoding</replaceable>
-    TO <replaceable>dest_encoding</replaceable> FROM <replaceable>funcname</replaceable>
+    FOR <replaceable>source_encoding</replaceable> TO <replaceable>dest_encoding</replaceable> FROM <replaceable>funcname</replaceable>
 </synopsis>
  </refsynopsisdiv>
   
@@ -24,18 +23,16 @@ CREATE [DEFAULT] CONVERSION <replaceable>conversion_name</replaceable>
 
   <para>
    <command>CREATE CONVERSION</command> defines a new encoding
-   conversion. There are two kinds of conversions. A default
-   conversion is used for an automatic encoding conversion between
-   frontend and backend. There should be only one default conversion
-   for source/destination encodings pair in a schema. None default
-   conversion never be used for the automatic conversion. Instead it
-   can be used for CONVERT() function.
+   conversion.  Conversion names may be used in the CONVERT() function
+   to specify a particular encoding conversion.  Also, conversions that
+   are marked DEFAULT can be used for automatic encoding conversion between
+   frontend and backend. For this purpose, two conversions, from encoding A to
+   B AND from encoding B to A, must be defined.
  </para>
 
   <para>
    To be able to create a conversion, you must have the execute right
-   on the function and the usage right on the schema the function
-   belongs to.
+   on the function and the create right on the destination schema.
   </para>
 
    <variablelist>
@@ -49,11 +46,7 @@ CREATE [DEFAULT] CONVERSION <replaceable>conversion_name</replaceable>
        The <literal>DEFAULT</> clause indicates that this conversion
        is the default for this particular source to destination
        encoding. There should be only one default encoding in a schema
-       for the encoding pair. A default encoding can be used for not
-       only CONVERT() function, but also for the automatic encoding
-       conversion between frontend and backend. For this purpose, two
-       conversions, from encoding A to B AND encoding B to A, must be
-       defined.
+       for the encoding pair.
       </para>
      </listitem>
     </varlistentry>
@@ -64,8 +57,8 @@ CREATE [DEFAULT] CONVERSION <replaceable>conversion_name</replaceable>
      <listitem>
       <para>
        The name of the conversion. The conversion name may be
-       schema-qualified. If it is not, a conversion is defined in the
-       current schema. The conversion name must be unique with in a
+       schema-qualified. If it is not, the conversion is defined in the
+       current schema. The conversion name must be unique within a
        schema.
       </para>
      </listitem>
@@ -102,7 +95,7 @@ CREATE [DEFAULT] CONVERSION <replaceable>conversion_name</replaceable>
        </para>
 
        <para>
-       The function must have following signature:
+       The function must have the following signature:
 
        <programlisting>
 	conv_proc(

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 1.36 2002/09/23 20:43:40 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.37 2002/11/02 02:33:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1275,40 +1275,41 @@ PopSpecialNamespace(Oid namespaceId)
 Oid
 FindConversionByName(List *name)
 {
+	char	   *schemaname;
 	char	   *conversion_name;
 	Oid			namespaceId;
 	Oid			conoid;
 	List	   *lptr;
 
-	/* Convert list of names to a name and namespace */
-	namespaceId = QualifiedNameGetCreationNamespace(name, &conversion_name);
+	/* deconstruct the name list */
+	DeconstructQualifiedName(name, &schemaname, &conversion_name);
 
-	if (length(name) > 1)
+	if (schemaname)
 	{
-		/* Check we have usage rights in target namespace */
-		if (pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE) != ACLCHECK_OK)
-			return InvalidOid;
-
+		/* use exact schema given */
+		namespaceId = LookupExplicitNamespace(schemaname);
 		return FindConversion(conversion_name, namespaceId);
 	}
-
+	else
+	{
+		/* search for it in search path */
 		recomputeNamespacePath();
 
 		foreach(lptr, namespaceSearchPath)
 		{
-		Oid			namespaceId = (Oid) lfirsti(lptr);
-
+			namespaceId = (Oid) lfirsti(lptr);
 			conoid = FindConversion(conversion_name, namespaceId);
 			if (OidIsValid(conoid))
 				return conoid;
 		}
+	}
 
 	/* Not found in path */
 	return InvalidOid;
 }
 
 /*
- * FindDefaultConversionProc - find default encoding cnnversion proc
+ * FindDefaultConversionProc - find default encoding conversion proc
  */
 Oid
 FindDefaultConversionProc(int4 for_encoding, int4 to_encoding)

src/backend/catalog/pg_conversion.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_conversion.c,v 1.6 2002/09/04 20:31:14 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_conversion.c,v 1.7 2002/11/02 02:33:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,16 +30,15 @@
 #include "utils/acl.h"
 #include "miscadmin.h"
 
-/* ----------------
+/*
  * ConversionCreate
  *
- * Add a new tuple to pg_coversion.
- * ---------------
+ * Add a new tuple to pg_conversion.
  */
 Oid
 ConversionCreate(const char *conname, Oid connamespace,
 				 int32 conowner,
-				 int4 conforencoding, int4 contoencoding,
+				 int32 conforencoding, int32 contoencoding,
 				 Oid conproc, bool def)
 {
 	int			i;
@@ -58,7 +57,7 @@ ConversionCreate(const char *conname, Oid connamespace,
 		elog(ERROR, "no conversion name supplied");
 
 	/* make sure there is no existing conversion of same name */
-	if (SearchSysCacheExists(CONNAMESP,
+	if (SearchSysCacheExists(CONNAMENSP,
 							 PointerGetDatum(conname),
 							 ObjectIdGetDatum(connamespace),
 							 0, 0))
@@ -74,7 +73,8 @@ ConversionCreate(const char *conname, Oid connamespace,
 								  conforencoding,
 								  contoencoding))
 			elog(ERROR, "default conversion for %s to %s already exists",
-				 pg_encoding_to_char(conforencoding), pg_encoding_to_char(contoencoding));
+				 pg_encoding_to_char(conforencoding),
+				 pg_encoding_to_char(contoencoding));
 	}
 
 	/* open pg_conversion */
@@ -96,10 +96,7 @@ ConversionCreate(const char *conname, Oid connamespace,
 	values[Anum_pg_conversion_conforencoding - 1] = Int32GetDatum(conforencoding);
 	values[Anum_pg_conversion_contoencoding - 1] = Int32GetDatum(contoencoding);
 	values[Anum_pg_conversion_conproc - 1] = ObjectIdGetDatum(conproc);
-	if (def == true)
 	values[Anum_pg_conversion_condefault - 1] = BoolGetDatum(def);
-	else
-		nulls[Anum_pg_conversion_condefault - 1] = 'n';
 
 	tup = heap_formtuple(tupDesc, values, nulls);
 
@@ -110,11 +107,11 @@ ConversionCreate(const char *conname, Oid connamespace,
 	/* update the index if any */
 	CatalogUpdateIndexes(rel, tup);
 
-	myself.classId = get_system_catalog_relid(ConversionRelationName);
+	myself.classId = RelationGetRelid(rel);
 	myself.objectId = HeapTupleGetOid(tup);
 	myself.objectSubId = 0;
 
-	/* dependency on conversion procedure */
+	/* create dependency on conversion procedure */
 	referenced.classId = RelOid_pg_proc;
 	referenced.objectId = conproc;
 	referenced.objectSubId = 0;
@@ -126,79 +123,46 @@ ConversionCreate(const char *conname, Oid connamespace,
 	return oid;
 }
 
-/* ----------------
+/*
  * ConversionDrop
  *
- * Drop a conversion and do dependency check.
- * ---------------
+ * Drop a conversion after doing permission checks.
  */
 void
-ConversionDrop(const char *conname, Oid connamespace,
-			   int32 conowner, DropBehavior behavior)
+ConversionDrop(Oid conversionOid, DropBehavior behavior)
 {
-	Relation	rel;
-	TupleDesc	tupDesc;
 	HeapTuple	tuple;
-	HeapScanDesc scan;
-	ScanKeyData scanKeyData;
-	Form_pg_conversion body;
 	ObjectAddress object;
-	Oid			myoid;
-
-	/* sanity checks */
-	if (!conname)
-		elog(ERROR, "no conversion name supplied");
-
-	ScanKeyEntryInitialize(&scanKeyData,
-						   0,
-						   Anum_pg_conversion_connamespace,
-						   F_OIDEQ,
-						   ObjectIdGetDatum(connamespace));
-
-	/* open pg_conversion */
-	rel = heap_openr(ConversionRelationName, AccessShareLock);
-	tupDesc = rel->rd_att;
-
-	scan = heap_beginscan(rel, SnapshotNow,
-						  1, &scanKeyData);
-
-	/* search for the target tuple */
-	while (HeapTupleIsValid(tuple = heap_getnext(scan, ForwardScanDirection)))
-	{
-		body = (Form_pg_conversion) GETSTRUCT(tuple);
-		if (!strncmp(NameStr(body->conname), conname, NAMEDATALEN))
-			break;
-	}
 
+	tuple = SearchSysCache(CONOID,
+						   ObjectIdGetDatum(conversionOid),
+						   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
-	{
-		elog(ERROR, "conversion %s not found", conname);
-		return;
-	}
+		elog(ERROR, "Conversion %u search from syscache failed",
+			 conversionOid);
 
-	if (!superuser() && ((Form_pg_conversion) GETSTRUCT(tuple))->conowner != GetUserId())
+	if (!superuser() &&
+		((Form_pg_conversion) GETSTRUCT(tuple))->conowner != GetUserId())
 		elog(ERROR, "permission denied");
 
-	myoid = HeapTupleGetOid(tuple);
-	heap_endscan(scan);
-	heap_close(rel, AccessShareLock);
+	ReleaseSysCache(tuple);
 
 	/*
 	 * Do the deletion
 	 */
 	object.classId = get_system_catalog_relid(ConversionRelationName);
-	object.objectId = myoid;
+	object.objectId = conversionOid;
 	object.objectSubId = 0;
 
 	performDeletion(&object, behavior);
 }
 
-/* ----------------
+/*
  * RemoveConversionById
  *
- * Remove a tuple from pg_conversion by Oid. This function is soley
+ * Remove a tuple from pg_conversion by Oid. This function is solely
  * called inside catalog/dependency.c
- * --------------- */
+ */
 void
 RemoveConversionById(Oid conversionOid)
 {
@@ -230,15 +194,17 @@ RemoveConversionById(Oid conversionOid)
 	heap_close(rel, RowExclusiveLock);
 }
 
-/* ----------------
+/*
  * FindDefaultConversion
  *
- * Find "default" conversion proc by for_encoding and to_encoding in this name space.
- * If found, returns the procedure's oid, otherwise InvalidOid.
- * ---------------
+ * Find "default" conversion proc by for_encoding and to_encoding in the
+ * given namespace.
+ *
+ * If found, returns the procedure's oid, otherwise InvalidOid.  Note that
+ * you get the procedure's OID not the conversion's OID!
  */
 Oid
-FindDefaultConversion(Oid name_space, int4 for_encoding, int4 to_encoding)
+FindDefaultConversion(Oid name_space, int32 for_encoding, int32 to_encoding)
 {
 	CatCList   *catlist;
 	HeapTuple	tuple;
@@ -246,10 +212,6 @@ FindDefaultConversion(Oid name_space, int4 for_encoding, int4 to_encoding)
 	Oid			proc = InvalidOid;
 	int			i;
 
-	/* Check we have usage rights in target namespace */
-	if (pg_namespace_aclcheck(name_space, GetUserId(), ACL_USAGE) != ACLCHECK_OK)
-		return proc;
-
 	catlist = SearchSysCacheList(CONDEFAULT, 3,
 								 ObjectIdGetDatum(name_space),
 								 Int32GetDatum(for_encoding),
@@ -260,7 +222,7 @@ FindDefaultConversion(Oid name_space, int4 for_encoding, int4 to_encoding)
 	{
 		tuple = &catlist->members[i]->tuple;
 		body = (Form_pg_conversion) GETSTRUCT(tuple);
-		if (body->condefault == TRUE)
+		if (body->condefault)
 		{
 			proc = body->conproc;
 			break;
@@ -270,12 +232,11 @@ FindDefaultConversion(Oid name_space, int4 for_encoding, int4 to_encoding)
 	return proc;
 }
 
-/* ----------------
- * FindConversionByName
+/*
+ * FindConversion
  *
  * Find conversion by namespace and conversion name.
- * Returns conversion oid.
- * ---------------
+ * Returns conversion OID.
  */
 Oid
 FindConversion(const char *conname, Oid connamespace)
@@ -286,13 +247,13 @@ FindConversion(const char *conname, Oid connamespace)
 	AclResult	aclresult;
 
 	/* search pg_conversion by connamespace and conversion name */
-	tuple = SearchSysCache(CONNAMESP,
+	tuple = SearchSysCache(CONNAMENSP,
 						   PointerGetDatum(conname),
 						   ObjectIdGetDatum(connamespace),
 						   0, 0);
-
 	if (!HeapTupleIsValid(tuple))
 		return InvalidOid;
+
 	procoid = ((Form_pg_conversion) GETSTRUCT(tuple))->conproc;
 	conoid = HeapTupleGetOid(tuple);
 

src/backend/commands/conversioncmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/conversioncmds.c,v 1.4 2002/09/04 20:31:14 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/conversioncmds.c,v 1.5 2002/11/02 02:33:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -38,17 +38,14 @@ CreateConversionCommand(CreateConversionStmt *stmt)
 	int			for_encoding;
 	int			to_encoding;
 	Oid			funcoid;
-	Oid			funcnamespace;
-	char	   *dummy;
-
 	const char *for_encoding_name = stmt->for_encoding_name;
 	const char *to_encoding_name = stmt->to_encoding_name;
 	List	   *func_name = stmt->func_name;
-
 	static Oid	funcargs[] = {INT4OID, INT4OID, CSTRINGOID, CSTRINGOID, INT4OID};
 
 	/* Convert list of names to a name and namespace */
-	namespaceId = QualifiedNameGetCreationNamespace(stmt->conversion_name, &conversion_name);
+	namespaceId = QualifiedNameGetCreationNamespace(stmt->conversion_name,
+													&conversion_name);
 
 	/* Check we have creation rights in target namespace */
 	aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE);
@@ -70,17 +67,13 @@ CreateConversionCommand(CreateConversionStmt *stmt)
 	 */
 	funcoid = LookupFuncName(func_name, sizeof(funcargs) / sizeof(Oid), funcargs);
 	if (!OidIsValid(funcoid))
-		elog(ERROR, "Function %s does not exist", NameListToString(func_name));
-
-	/* Check the rights for this function and name space */
-	funcnamespace = QualifiedNameGetCreationNamespace(func_name, &dummy);
-	aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE);
-	if (aclresult != ACLCHECK_OK)
-		aclcheck_error(aclresult, get_namespace_name(funcnamespace));
+		func_error("CreateConversion", func_name,
+				   sizeof(funcargs) / sizeof(Oid), funcargs, NULL);
 
+	/* Check we have EXECUTE rights for the function */
 	aclresult = pg_proc_aclcheck(funcoid, GetUserId(), ACL_EXECUTE);
 	if (aclresult != ACLCHECK_OK)
-		aclcheck_error(aclresult, get_namespace_name(funcnamespace));
+		aclcheck_error(aclresult, NameListToString(func_name));
 
 	/*
 	 * All seem ok, go ahead (possible failure would be a duplicate
@@ -96,21 +89,12 @@ CreateConversionCommand(CreateConversionStmt *stmt)
 void
 DropConversionCommand(List *name, DropBehavior behavior)
 {
-	Oid			namespaceId;
-	char	   *conversion_name;
-	AclResult	aclresult;
+	Oid			conversionOid;
 
-	/* Convert list of names to a name and namespace */
-	namespaceId = QualifiedNameGetCreationNamespace(name, &conversion_name);
+	conversionOid = FindConversionByName(name);
 
-	/* Check we have creation rights in target namespace */
-	aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE);
-	if (aclresult != ACLCHECK_OK)
-		aclcheck_error(aclresult, get_namespace_name(namespaceId));
+	if (!OidIsValid(conversionOid))
+		elog(ERROR, "conversion %s not found", NameListToString(name));
 
-	/*
-	 * Go ahead (possible failure would be: none existing conversion not
-	 * ower of this conversion
-	 */
-	ConversionDrop(conversion_name, namespaceId, GetUserId(), behavior);
+	ConversionDrop(conversionOid, behavior);
 }

src/include/catalog/pg_conversion.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_conversion.h,v 1.6 2002/09/04 20:31:37 momjian Exp $
+ * $Id: pg_conversion.h,v 1.7 2002/11/02 02:33:03 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -85,12 +85,11 @@ typedef FormData_pg_conversion *Form_pg_conversion;
 
 extern Oid ConversionCreate(const char *conname, Oid connamespace,
 				 int32 conowner,
-				 int4 conforencoding, int4 contoencoding,
+				 int32 conforencoding, int32 contoencoding,
 				 Oid conproc, bool def);
-extern void ConversionDrop(const char *conname, Oid connamespace,
-			   int32 conowner, DropBehavior behavior);
+extern void ConversionDrop(Oid conversionOid, DropBehavior behavior);
 extern void RemoveConversionById(Oid conversionOid);
 extern Oid	FindConversion(const char *conname, Oid connamespace);
-extern Oid	FindDefaultConversion(Oid connamespace, int4 for_encoding, int4 to_encoding);
+extern Oid	FindDefaultConversion(Oid connamespace, int32 for_encoding, int32 to_encoding);
 
 #endif   /* PG_CONVERSION_H */

src/include/utils/syscache.h

@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: syscache.h,v 1.53 2002/09/04 20:31:46 momjian Exp $
+ * $Id: syscache.h,v 1.54 2002/11/02 02:33:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,7 +40,7 @@
 #define CLAAMNAMENSP	9
 #define CLAOID			10
 #define CONDEFAULT		11
-#define CONNAMESP		12
+#define CONNAMENSP		12
 #define CONOID			13
 #define GRONAME			14
 #define GROSYSID		15