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First step done,

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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;
This commit is contained in:
Marc G. Fournier
1998-02-21 06:32:15 +00:00
parent 734328840c
commit 7b30490bc9
7 changed files with 126 additions and 17 deletions
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110
src/backend/rewrite/rewriteHandler.c
View File

@ -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;
@ -256,16 +264,41 @@ ApplyRetrieveRule(Query *parsetree,
int nothing,
rt_length;
int badsql = FALSE;
int viewAclOverride = FALSE;
rule_qual = rule->qual;
if (rule->actions)
{
if (length(rule->actions) > 1) /* ??? because we don't handle
* rules with more than one
* action? -ay */
* 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);
rtable = nconc(rtable, copyObject(rule_action->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]);
}
}
}