From 632cd9f892119858bc5b617bb60c0377a8a2ed13 Mon Sep 17 00:00:00 2001
From: Joe Conway <mail@joeconway.com>
Date: Wed, 29 Jul 2015 15:37:48 -0700
Subject: [PATCH] Create new ParseExprKind for use by policy expressions.
Policy USING and WITH CHECK expressions were using EXPR_KIND_WHERE for
parse analysis, which results in inappropriate ERROR messages when
the expression contains unsupported constructs such as aggregates.
Create a new ParseExprKind called EXPR_KIND_POLICY and tailor the
related messages to fit.
Reported by Noah Misch. Reviewed by Dean Rasheed, Alvaro Herrera,
and Robert Haas. Back-patch to 9.5 where RLS was introduced.
---
src/backend/commands/policy.c | 8 ++++----
src/backend/parser/parse_agg.c | 10 ++++++++++
src/backend/parser/parse_expr.c | 3 +++
src/include/parser/parse_node.h | 3 ++-
src/test/modules/test_rls_hooks/test_rls_hooks.c | 4 ++--
src/test/regress/expected/rowsecurity.out | 9 +++++++++
src/test/regress/sql/rowsecurity.sql | 9 +++++++++
7 files changed, 39 insertions(+), 7 deletions(-)
diff --git a/src/backend/commands/policy.c b/src/backend/commands/policy.c
index d8b43908ec..bcf4a8f35d 100644
--- a/src/backend/commands/policy.c
+++ b/src/backend/commands/policy.c
@@ -534,12 +534,12 @@ CreatePolicy(CreatePolicyStmt *stmt)
qual = transformWhereClause(qual_pstate,
copyObject(stmt->qual),
- EXPR_KIND_WHERE,
+ EXPR_KIND_POLICY,
"POLICY");
with_check_qual = transformWhereClause(with_check_pstate,
copyObject(stmt->with_check),
- EXPR_KIND_WHERE,
+ EXPR_KIND_POLICY,
"POLICY");
/* Fix up collation information */
@@ -707,7 +707,7 @@ AlterPolicy(AlterPolicyStmt *stmt)
addRTEtoQuery(qual_pstate, rte, false, true, true);
qual = transformWhereClause(qual_pstate, copyObject(stmt->qual),
- EXPR_KIND_WHERE,
+ EXPR_KIND_POLICY,
"POLICY");
/* Fix up collation information */
@@ -730,7 +730,7 @@ AlterPolicy(AlterPolicyStmt *stmt)
with_check_qual = transformWhereClause(with_check_pstate,
copyObject(stmt->with_check),
- EXPR_KIND_WHERE,
+ EXPR_KIND_POLICY,
"POLICY");
/* Fix up collation information */
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 478d8ca70b..3846b569d6 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -372,6 +372,13 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
break;
case EXPR_KIND_WHERE:
errkind = true;
+ break;
+ case EXPR_KIND_POLICY:
+ if (isAgg)
+ err = _("aggregate functions are not allowed in policy expressions");
+ else
+ err = _("grouping operations are not allowed in policy expressions");
+
break;
case EXPR_KIND_HAVING:
/* okay */
@@ -770,6 +777,9 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_WHERE:
errkind = true;
break;
+ case EXPR_KIND_POLICY:
+ err = _("window functions are not allowed in policy expressions");
+ break;
case EXPR_KIND_HAVING:
errkind = true;
break;
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 0ff46dd457..fa77ef1f8b 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -1672,6 +1672,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_FROM_SUBSELECT:
case EXPR_KIND_FROM_FUNCTION:
case EXPR_KIND_WHERE:
+ case EXPR_KIND_POLICY:
case EXPR_KIND_HAVING:
case EXPR_KIND_FILTER:
case EXPR_KIND_WINDOW_PARTITION:
@@ -3173,6 +3174,8 @@ ParseExprKindName(ParseExprKind exprKind)
return "function in FROM";
case EXPR_KIND_WHERE:
return "WHERE";
+ case EXPR_KIND_POLICY:
+ return "POLICY";
case EXPR_KIND_HAVING:
return "HAVING";
case EXPR_KIND_FILTER:
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 7ecaffc0dc..5249945369 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -63,7 +63,8 @@ typedef enum ParseExprKind
EXPR_KIND_INDEX_PREDICATE, /* index predicate */
EXPR_KIND_ALTER_COL_TRANSFORM, /* transform expr in ALTER COLUMN TYPE */
EXPR_KIND_EXECUTE_PARAMETER, /* parameter value in EXECUTE */
- EXPR_KIND_TRIGGER_WHEN /* WHEN condition in CREATE TRIGGER */
+ EXPR_KIND_TRIGGER_WHEN, /* WHEN condition in CREATE TRIGGER */
+ EXPR_KIND_POLICY /* USING or WITH CHECK expr in policy */
} ParseExprKind;
diff --git a/src/test/modules/test_rls_hooks/test_rls_hooks.c b/src/test/modules/test_rls_hooks/test_rls_hooks.c
index 61b62d55b4..d76b17ae46 100644
--- a/src/test/modules/test_rls_hooks/test_rls_hooks.c
+++ b/src/test/modules/test_rls_hooks/test_rls_hooks.c
@@ -106,7 +106,7 @@ test_rls_hooks_permissive(CmdType cmdtype, Relation relation)
e = (Node *) makeSimpleA_Expr(AEXPR_OP, "=", (Node *) n, (Node *) c, 0);
policy->qual = (Expr *) transformWhereClause(qual_pstate, copyObject(e),
- EXPR_KIND_WHERE,
+ EXPR_KIND_POLICY,
"POLICY");
policy->with_check_qual = copyObject(policy->qual);
@@ -160,7 +160,7 @@ test_rls_hooks_restrictive(CmdType cmdtype, Relation relation)
e = (Node *) makeSimpleA_Expr(AEXPR_OP, "=", (Node *) n, (Node *) c, 0);
policy->qual = (Expr *) transformWhereClause(qual_pstate, copyObject(e),
- EXPR_KIND_WHERE,
+ EXPR_KIND_POLICY,
"POLICY");
policy->with_check_qual = copyObject(policy->qual);
diff --git a/src/test/regress/expected/rowsecurity.out b/src/test/regress/expected/rowsecurity.out
index b146da373c..b0556c2ff1 100644
--- a/src/test/regress/expected/rowsecurity.out
+++ b/src/test/regress/expected/rowsecurity.out
@@ -3024,6 +3024,15 @@ CREATE RULE "_RETURN" AS ON SELECT TO t DO INSTEAD
SELECT * FROM generate_series(1,5) t0(c); -- succeeds
ROLLBACK;
--
+-- Policy expression handling
+--
+BEGIN;
+SET row_security = FORCE;
+CREATE TABLE t (c) AS VALUES ('bar'::text);
+CREATE POLICY p ON t USING (max(c)); -- fails: aggregate functions are not allowed in policy expressions
+ERROR: aggregate functions are not allowed in policy expressions
+ROLLBACK;
+--
-- Clean up objects
--
RESET SESSION AUTHORIZATION;
diff --git a/src/test/regress/sql/rowsecurity.sql b/src/test/regress/sql/rowsecurity.sql
index 54f2c89eda..300f34ad4b 100644
--- a/src/test/regress/sql/rowsecurity.sql
+++ b/src/test/regress/sql/rowsecurity.sql
@@ -1289,6 +1289,15 @@ CREATE RULE "_RETURN" AS ON SELECT TO t DO INSTEAD
SELECT * FROM generate_series(1,5) t0(c); -- succeeds
ROLLBACK;
+--
+-- Policy expression handling
+--
+BEGIN;
+SET row_security = FORCE;
+CREATE TABLE t (c) AS VALUES ('bar'::text);
+CREATE POLICY p ON t USING (max(c)); -- fails: aggregate functions are not allowed in policy expressions
+ROLLBACK;
+
--
-- Clean up objects
--
--
2.40.0