First step done,

below  is  the patch to have views to override the permission
    checks for the accessed tables. Now we can do the following:

    CREATE VIEW db_user AS SELECT
         usename,
         usesysid,
         usecreatedb,
         usetrace,
         usecatupd,
         '**********'::text as passwd,
         valuntil
        FROM pg_user;

    REVOKE ALL ON pg_user FROM public;
    REVOKE ALL ON db_user FROM public;
    GRANT SELECT ON db_user TO public;

src/backend/executor/execMain.c

@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.42 1998/02/13 03:26:38 vadim Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.43 1998/02/21 06:31:37 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -299,6 +299,17 @@ ExecCheckPerms(CmdType operation,
 	{
 		RangeTblEntry *rte = lfirst(lp);
 
+		if (rte->skipAcl)
+		{
+			/*
+			 * This happens if the access to this table is due
+			 * to a view query rewriting - the rewrite handler
+			 * checked the permissions against the view owner,
+			 * so we just skip this entry.
+			 */
+			continue;
+		}
+
 		relid = rte->relid;
 		htp = SearchSysCacheTuple(RELOID,
 								  ObjectIdGetDatum(relid),

src/backend/nodes/copyfuncs.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.38 1998/02/13 03:27:42 vadim Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.39 1998/02/21 06:31:40 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1495,6 +1495,7 @@ _copyRangeTblEntry(RangeTblEntry *from)
 	newnode->relid = from->relid;
 	newnode->inh = from->inh;
 	newnode->inFromCl = from->inFromCl;
+	newnode->skipAcl  = from->skipAcl;
 
 		
 	return newnode;

src/backend/parser/gram.c

@@ -210,7 +210,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/Attic/gram.c,v 2.1 1998/02/18 07:28:06 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/Attic/gram.c,v 2.2 1998/02/21 06:31:46 scrappy Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -3753,7 +3753,7 @@ static const short yycheck[] = {     3,
     -1,    -1,    -1,   172
 };
 /* -*-C-*-  Note some compilers choke on comments on `#line' lines.  */
-#line 3 "/usr/lib/bison.simple"
+#line 3 "/usr/share/misc/bison.simple"
 
 /* Skeleton output parser for bison,
    Copyright (C) 1984, 1989, 1990 Free Software Foundation, Inc.
@@ -3946,7 +3946,7 @@ __yy_memcpy (char *to, char *from, int count)
 #endif
 #endif
 
-#line 196 "/usr/lib/bison.simple"
+#line 196 "/usr/share/misc/bison.simple"
 
 /* The user can define YYPARSE_PARAM as the name of an argument to be passed
    into yyparse.  The argument should have type void *.
@@ -9401,7 +9401,7 @@ case 842:
     break;}
 }
    /* the action file gets copied in in place of this dollarsign */
-#line 498 "/usr/lib/bison.simple"
+#line 498 "/usr/share/misc/bison.simple"
 
   yyvsp -= yylen;
   yyssp -= yylen;

src/backend/parser/scan.c

@@ -1,7 +1,7 @@
 /* A lexical scanner generated by flex */
 
 /* Scanner skeleton version:
- * $Header: /cvsroot/pgsql/src/backend/parser/Attic/scan.c,v 1.14 1998/02/18 07:23:22 thomas Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/Attic/scan.c,v 1.15 1998/02/21 06:31:52 scrappy Exp $
  */
 
 #define FLEX_SCANNER
@@ -547,7 +547,7 @@ char *yytext;
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/Attic/scan.c,v 1.14 1998/02/18 07:23:22 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/Attic/scan.c,v 1.15 1998/02/21 06:31:52 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */

src/backend/rewrite/rewriteHandler.c

@@ -6,10 +6,11 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.11 1998/01/21 04:24:36 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.12 1998/02/21 06:31:57 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
+#include <string.h>
 #include "postgres.h"
 #include "miscadmin.h"
 #include "utils/palloc.h"
@@ -29,13 +30,19 @@
 #include "commands/creatinh.h"
 #include "access/heapam.h"
 
+#include "utils/syscache.h"
+#include "utils/acl.h"
+#include "catalog/pg_user.h"
+
 static void ApplyRetrieveRule(Query *parsetree, RewriteRule *rule,
-				  int rt_index, int relation_level, int *modified);
+				  int rt_index, int relation_level,
+				  Relation relation, int *modified);
 static List *fireRules(Query *parsetree, int rt_index, CmdType event,
 		  bool *instead_flag, List *locks, List **qual_products);
 static void QueryRewriteSubLink(Node *node);
 static List	   *QueryRewriteOne(Query *parsetree);
 static List *deepRewriteQuery(Query *parsetree);
+static void CheckViewPerms(Relation view, List *rtable);
 
 /*
  * gatherRewriteMeta -
@@ -219,7 +226,7 @@ FireRetrieveRulesAtQuery(Query *parsetree,
 				*instead_flag = TRUE;
 				return rule_lock->actions;
 			}
-			ApplyRetrieveRule(parsetree, rule_lock, rt_index, relation_level,
+			ApplyRetrieveRule(parsetree, rule_lock, rt_index, relation_level, relation,
 							  &modified);
 			if (modified)
 			{
@@ -247,6 +254,7 @@ ApplyRetrieveRule(Query *parsetree,
 				  RewriteRule *rule,
 				  int rt_index,
 				  int relation_level,
+				  Relation relation,
 				  int *modified)
 {
 	Query	   *rule_action = NULL;
@@ -256,6 +264,7 @@ ApplyRetrieveRule(Query *parsetree,
 	int			nothing,
 				rt_length;
 	int			badsql = FALSE;
+	int			viewAclOverride = FALSE;
 
 	rule_qual = rule->qual;
 	if (rule->actions)
@@ -263,9 +272,33 @@ ApplyRetrieveRule(Query *parsetree,
 		if (length(rule->actions) > 1)	/* ??? because we don't handle
 						 * rules with more than one
 						 * action? -ay */
+
+						/* WARNING!!!
+						 * If we sometimes handle
+						 * rules with more than one
+						 * action, the view acl checks
+						 * might get broken. 
+						 * viewAclOverride should only
+						 * become true (below) if this
+						 * is a relation_level, instead,
+						 * select query - Jan
+						 */
 			return;
 		rule_action = copyObject(lfirst(rule->actions));
 		nothing = FALSE;
+
+		/*
+		 * If this rule is on the relation level, the rule action
+		 * is a select and the rule is instead then it must be
+		 * a view. Permissions for views now follow the owner of
+		 * the view, not the current user.
+		 */
+		if (relation_level && rule_action->commandType == CMD_SELECT
+					&& rule->isInstead)
+		{
+		    CheckViewPerms(relation, rule_action->rtable);
+		    viewAclOverride = TRUE;
+		}
 	}
 	else
 	{
@@ -284,7 +317,30 @@ ApplyRetrieveRule(Query *parsetree,
 		rte->inFromCl = false;
 	}
 	rt_length = length(rtable);
+
+	if (viewAclOverride)
+	{
+		List		*rule_rtable, *rule_rt;
+		RangeTblEntry	*rte;
+
+		rule_rtable = copyObject(rule_action->rtable);
+		foreach(rule_rt, rule_rtable)
+		{
+			rte = lfirst(rule_rt);
+
+			/*
+			 * tell the executor that the ACL check on this
+			 * range table entry is already done
+			 */
+			rte->skipAcl = true;
+		}
+
+		rtable = nconc(rtable, rule_rtable);
+	}
+	else
+	{
 		rtable = nconc(rtable, copyObject(rule_action->rtable));
+	}
 	parsetree->rtable = rtable;
 
 	rule_action->rtable = rtable;
@@ -750,3 +806,45 @@ deepRewriteQuery(Query *parsetree)
 
 	return rewritten;
 }
+
+
+static void
+CheckViewPerms(Relation view, List *rtable)
+{
+	HeapTuple	utup;
+	NameData	uname;
+	List		*rt;
+	RangeTblEntry	*rte;
+	int32		aclcheck_res;
+
+	/*
+	 * get the usename of the view's owner
+	 */
+	utup = SearchSysCacheTuple(USESYSID, view->rd_rel->relowner, 0, 0, 0);
+	if (!HeapTupleIsValid(utup))
+	{
+		elog(ERROR, "cache lookup for userid %d failed",
+						view->rd_rel->relowner);
+	}
+	StrNCpy(uname.data,
+			((Form_pg_user) GETSTRUCT(utup))->usename.data,
+			NAMEDATALEN);
+
+	/*
+	 * check that we have read access to all the
+	 * classes in the range table of the view
+	 */
+	foreach(rt, rtable)
+	{
+		rte = (RangeTblEntry *)lfirst(rt);
+
+		aclcheck_res = pg_aclcheck(rte->relname, uname.data, ACL_RD);
+		if (aclcheck_res != ACLCHECK_OK)
+		{
+			elog(ERROR, "%s: %s", rte->relname, aclcheck_error_strings[aclcheck_res]);
+		}
+	}
+}
+
+
+

src/include/nodes/parsenodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.47 1998/02/10 16:04:26 momjian Exp $
+ * $Id: parsenodes.h,v 1.48 1998/02/21 06:32:02 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -864,6 +864,7 @@ typedef struct RangeTblEntry
 	Oid			relid;
 	bool		inh;			/* inheritance? */
 	bool		inFromCl;		/* comes from From Clause */
+	bool		skipAcl;		/* skip ACL check in executor */
 } RangeTblEntry;
 
 /*

src/interfaces/ecpg/Makefile

@@ -1,7 +1,5 @@
 SUBDIRS = include lib preproc doc
 
 all install uninstall clean:
-	$(MAKE) -C include $@
 	$(MAKE) -C lib $@
 	$(MAKE) -C preproc $@
-#	$(MAKE) -C doc $@