Centralize DML permissions-checking logic.

Remove bespoke code in DoCopy and RI_Initial_Check, which now instead
fabricate call ExecCheckRTPerms with a manufactured RangeTblEntry.
This is intended to make it feasible for an enhanced security provider
to actually make use of ExecutorCheckPerms_hook, but also has the
advantage that RI_Initial_Check can allow use of the fast-path when
column-level but not table-level permissions are present.

KaiGai Kohei.  Reviewed (in an earlier version) by Stephen Frost, and by me.
Some further changes to the comments by me.
This commit is contained in:
Robert Haas 2010-07-22 00:47:59 +00:00
parent 9f8cf32b34
commit b8c6c71d1c
4 changed files with 89 additions and 57 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.327 2010/04/28 16:10:41 heikki Exp $
* $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.328 2010/07/22 00:47:52 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@ -21,6 +21,7 @@
#include <arpa/inet.h>
#include "access/heapam.h"
#include "access/sysattr.h"
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
@ -726,8 +727,6 @@ DoCopy(const CopyStmt *stmt, const char *queryString)
bool force_quote_all = false;
bool format_specified = false;
AclMode required_access = (is_from ? ACL_INSERT : ACL_SELECT);
AclMode relPerms;
AclMode remainingPerms;
ListCell *option;
TupleDesc tupDesc;
int num_phys_attrs;
@ -988,6 +987,10 @@ DoCopy(const CopyStmt *stmt, const char *queryString)
if (stmt->relation)
{
RangeTblEntry *rte;
List *attnums;
ListCell *cur;
Assert(!stmt->query);
cstate->queryDesc = NULL;
@ -998,28 +1001,22 @@ DoCopy(const CopyStmt *stmt, const char *queryString)
tupDesc = RelationGetDescr(cstate->rel);
/* Check relation permissions. */
relPerms = pg_class_aclmask(RelationGetRelid(cstate->rel), GetUserId(),
required_access, ACLMASK_ALL);
remainingPerms = required_access & ~relPerms;
if (remainingPerms != 0)
rte = makeNode(RangeTblEntry);
rte->rtekind = RTE_RELATION;
rte->relid = RelationGetRelid(cstate->rel);
rte->requiredPerms = required_access;
attnums = CopyGetAttnums(tupDesc, cstate->rel, attnamelist);
foreach (cur, attnums)
{
/* We don't have table permissions, check per-column permissions */
List *attnums;
ListCell *cur;
int attno = lfirst_int(cur) - FirstLowInvalidHeapAttributeNumber;
attnums = CopyGetAttnums(tupDesc, cstate->rel, attnamelist);
foreach(cur, attnums)
{
int attnum = lfirst_int(cur);
if (pg_attribute_aclcheck(RelationGetRelid(cstate->rel),
attnum,
GetUserId(),
remainingPerms) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
RelationGetRelationName(cstate->rel));
}
if (is_from)
rte->modifiedCols = bms_add_member(rte->modifiedCols, attno);
else
rte->selectedCols = bms_add_member(rte->selectedCols, attno);
}
ExecCheckRTPerms(list_make1(rte), true);
/* check read-only transaction */
if (XactReadOnly && is_from && !cstate->rel->rd_islocaltemp)

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@ -26,7 +26,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.351 2010/07/12 17:01:05 tgl Exp $
* $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.352 2010/07/22 00:47:52 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@ -75,8 +75,7 @@ static void ExecutePlan(EState *estate, PlanState *planstate,
long numberTuples,
ScanDirection direction,
DestReceiver *dest);
static void ExecCheckRTPerms(List *rangeTable);
static void ExecCheckRTEPerms(RangeTblEntry *rte);
static bool ExecCheckRTEPerms(RangeTblEntry *rte);
static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
static void EvalPlanQualStart(EPQState *epqstate, EState *parentestate,
Plan *planTree);
@ -409,26 +408,42 @@ ExecutorRewind(QueryDesc *queryDesc)
/*
* ExecCheckRTPerms
* Check access permissions for all relations listed in a range table.
*
* Returns true if permissions are adequate. Otherwise, throws an appropriate
* error if ereport_on_violation is true, or simply returns false otherwise.
*/
static void
ExecCheckRTPerms(List *rangeTable)
bool
ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation)
{
ListCell *l;
bool result = true;
foreach(l, rangeTable)
{
ExecCheckRTEPerms((RangeTblEntry *) lfirst(l));
RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
result = ExecCheckRTEPerms(rte);
if (!result)
{
Assert(rte->rtekind == RTE_RELATION);
if (ereport_on_violation)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
get_rel_name(rte->relid));
return false;
}
}
if (ExecutorCheckPerms_hook)
(*ExecutorCheckPerms_hook)(rangeTable);
result = (*ExecutorCheckPerms_hook)(rangeTable,
ereport_on_violation);
return result;
}
/*
* ExecCheckRTEPerms
* Check access permissions for a single RTE.
*/
static void
static bool
ExecCheckRTEPerms(RangeTblEntry *rte)
{
AclMode requiredPerms;
@ -445,14 +460,14 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
* Join, subquery, and special RTEs need no checks.
*/
if (rte->rtekind != RTE_RELATION)
return;
return true;
/*
* No work if requiredPerms is empty.
*/
requiredPerms = rte->requiredPerms;
if (requiredPerms == 0)
return;
return true;
relOid = rte->relid;
@ -480,8 +495,7 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
* we can fail straight away.
*/
if (remainingPerms & ~(ACL_SELECT | ACL_INSERT | ACL_UPDATE))
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
get_rel_name(relOid));
return false;
/*
* Check to see if we have the needed privileges at column level.
@ -501,8 +515,7 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
{
if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
ACLMASK_ANY) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
get_rel_name(relOid));
return false;
}
tmpset = bms_copy(rte->selectedCols);
@ -515,15 +528,13 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
/* Whole-row reference, must have priv on all cols */
if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
ACLMASK_ALL) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
get_rel_name(relOid));
return false;
}
else
{
if (pg_attribute_aclcheck(relOid, col, userid, ACL_SELECT)
!= ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
get_rel_name(relOid));
if (pg_attribute_aclcheck(relOid, col, userid,
ACL_SELECT) != ACLCHECK_OK)
return false;
}
}
bms_free(tmpset);
@ -546,8 +557,7 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
{
if (pg_attribute_aclcheck_all(relOid, userid, remainingPerms,
ACLMASK_ANY) != ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
get_rel_name(relOid));
return false;
}
tmpset = bms_copy(rte->modifiedCols);
@ -562,15 +572,15 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
}
else
{
if (pg_attribute_aclcheck(relOid, col, userid, remainingPerms)
!= ACLCHECK_OK)
aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
get_rel_name(relOid));
if (pg_attribute_aclcheck(relOid, col, userid,
remainingPerms) != ACLCHECK_OK)
return false;
}
}
bms_free(tmpset);
}
}
return true;
}
/*
@ -636,7 +646,7 @@ InitPlan(QueryDesc *queryDesc, int eflags)
/*
* Do permissions checks
*/
ExecCheckRTPerms(rangeTable);
ExecCheckRTPerms(rangeTable, true);
/*
* initialize the node's execution state

View File

@ -15,7 +15,7 @@
*
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.118 2010/02/14 18:42:16 rhaas Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.119 2010/07/22 00:47:52 rhaas Exp $
*
* ----------
*/
@ -31,10 +31,12 @@
#include "postgres.h"
#include "access/xact.h"
#include "access/sysattr.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/spi.h"
#include "parser/parse_coerce.h"
#include "parser/parse_relation.h"
@ -2624,6 +2626,8 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char pkattname[MAX_QUOTED_NAME_LEN + 3];
char fkattname[MAX_QUOTED_NAME_LEN + 3];
RangeTblEntry *pkrte;
RangeTblEntry *fkrte;
const char *sep;
int i;
int old_work_mem;
@ -2631,6 +2635,9 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
int spi_result;
SPIPlanPtr qplan;
/* Fetch constraint info. */
ri_FetchConstraintInfo(&riinfo, trigger, fk_rel, false);
/*
* Check to make sure current user has enough permissions to do the test
* query. (If not, caller can fall back to the trigger method, which
@ -2638,12 +2645,29 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
*
* XXX are there any other show-stopper conditions to check?
*/
if (pg_class_aclcheck(RelationGetRelid(fk_rel), GetUserId(), ACL_SELECT) != ACLCHECK_OK)
return false;
if (pg_class_aclcheck(RelationGetRelid(pk_rel), GetUserId(), ACL_SELECT) != ACLCHECK_OK)
return false;
pkrte = makeNode(RangeTblEntry);
pkrte->rtekind = RTE_RELATION;
pkrte->relid = RelationGetRelid(pk_rel);
pkrte->requiredPerms = ACL_SELECT;
ri_FetchConstraintInfo(&riinfo, trigger, fk_rel, false);
fkrte = makeNode(RangeTblEntry);
fkrte->rtekind = RTE_RELATION;
fkrte->relid = RelationGetRelid(fk_rel);
fkrte->requiredPerms = ACL_SELECT;
for (i = 0; i < riinfo.nkeys; i++)
{
int attno;
attno = riinfo.pk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
pkrte->selectedCols = bms_add_member(pkrte->selectedCols, attno);
attno = riinfo.fk_attnums[i] - FirstLowInvalidHeapAttributeNumber;
fkrte->selectedCols = bms_add_member(fkrte->selectedCols, attno);
}
if (!ExecCheckRTPerms(list_make2(fkrte, pkrte), false))
return false;
/*----------
* The query string built is:

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.170 2010/07/12 17:01:06 tgl Exp $
* $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.171 2010/07/22 00:47:59 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@ -75,7 +75,7 @@ typedef void (*ExecutorEnd_hook_type) (QueryDesc *queryDesc);
extern PGDLLIMPORT ExecutorEnd_hook_type ExecutorEnd_hook;
/* Hook for plugins to get control in ExecCheckRTPerms() */
typedef void (*ExecutorCheckPerms_hook_type) (List *);
typedef bool (*ExecutorCheckPerms_hook_type) (List *, bool);
extern PGDLLIMPORT ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook;
@ -161,6 +161,7 @@ extern void standard_ExecutorRun(QueryDesc *queryDesc,
extern void ExecutorEnd(QueryDesc *queryDesc);
extern void standard_ExecutorEnd(QueryDesc *queryDesc);
extern void ExecutorRewind(QueryDesc *queryDesc);
extern bool ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation);
extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
Relation resultRelationDesc,
Index resultRelationIndex,