Add support for restrictive RLS policies

We have had support for restrictive RLS policies since 9.5, but they
were only available through extensions which use the appropriate hooks.
This adds support into the grammer, catalog, psql and pg_dump for
restrictive RLS policies, thus reducing the cases where an extension is
necessary.

In passing, also move away from using "AND"d and "OR"d in comments.
As pointed out by Alvaro, it's not really appropriate to attempt
to make verbs out of "AND" and "OR", so reword those comments which
attempted to.

Reviewed By: Jeevan Chalke, Dean Rasheed
Discussion: https://postgr.es/m/20160901063404.GY4028@tamriel.snowman.net

doc/src/sgml/catalogs.sgml

@@ -4747,6 +4747,13 @@
        or <literal>*</> for all</entry>
      </row>
 
+     <row>
+      <entry><structfield>polpermissive</structfield></entry>
+      <entry><type>boolean</type></entry>
+      <entry></entry>
+      <entry>Is the policy permissive or restrictive?</entry>
+     </row>
+
      <row>
       <entry><structfield>polroles</structfield></entry>
       <entry><type>oid[]</type></entry>
@@ -8437,6 +8444,12 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       <entry><literal><link linkend="catalog-pg-policy"><structname>pg_policy</structname></link>.polname</literal></entry>
       <entry>Name of policy</entry>
      </row>
+     <row>
+      <entry><structfield>polpermissive</structfield></entry>
+      <entry><type>text</type></entry>
+      <entry></entry>
+      <entry>Is the policy permissive or restrictive?</entry>
+     </row>
      <row>
       <entry><structfield>roles</structfield></entry>
       <entry><type>name[]</type></entry>

doc/src/sgml/ddl.sgml

@@ -1599,9 +1599,11 @@ REVOKE ALL ON accounts FROM PUBLIC;
 
   <para>
    When multiple policies apply to a given query, they are combined using
-   <literal>OR</literal>, so that a row is accessible if any policy allows
-   it.  This is similar to the rule that a given role has the privileges
-   of all roles that they are a member of.
+   either <literal>OR</literal> (for permissive policies, which are the
+   default) or using <literal>AND</literal> (for restrictive policies).
+   This is similar to the rule that a given role has the privileges
+   of all roles that they are a member of.  Permissive vs. restrictive
+   policies are discussed further below.
   </para>
 
   <para>
@@ -1761,6 +1763,56 @@ ERROR:  permission denied for relation passwd
 -- Alice can change her own password; RLS silently prevents updating other rows
 postgres=&gt; update passwd set pwhash = 'abc';
 UPDATE 1
+</programlisting>
+
+  <para>
+   All of the policies constructed thus far have been permissive policies,
+   meaning that when multiple policies are applied they are combined using
+   the "OR" boolean operator.  While permissive policies can be constructed
+   to only allow access to rows in the intended cases, it can be simpler to
+   combine permissive policies with restrictive policies (which the records
+   must pass and which are combined using the "AND" boolean operator).
+   Building on the example above, we add a restrictive policy to require
+   the administrator to be connected over a local unix socket to access the
+   records of the passwd table:
+  </para>
+
+<programlisting>
+CREATE POLICY admin_local_only ON passwd AS RESTRICTIVE TO admin
+    USING (pg_catalog.inet_client_addr() IS NULL);
+</programlisting>
+
+  <para>
+   We can then see that an administrator connecting over a network will not
+   see any records, due to the restrictive policy:
+  </para>
+
+<programlisting>
+=&gt; SELECT current_user;
+ current_user 
+--------------
+ admin
+(1 row)
+
+=&gt; select inet_client_addr();
+ inet_client_addr 
+------------------
+ 127.0.0.1
+(1 row)
+
+=&gt; SELECT current_user;
+ current_user 
+--------------
+ admin
+(1 row)
+
+=&gt; TABLE passwd;
+ user_name | pwhash | uid | gid | real_name | home_phone | extra_info | home_dir | shell
+-----------+--------+-----+-----+-----------+------------+------------+----------+-------
+(0 rows)
+
+=&gt; UPDATE passwd set pwhash = NULL;
+UPDATE 0
 </programlisting>
 
   <para>

doc/src/sgml/ref/alter_policy.sgml

@@ -35,7 +35,12 @@ ALTER POLICY <replaceable class="parameter">name</replaceable> ON <replaceable c
 
   <para>
    <command>ALTER POLICY</command> changes the definition of an existing
-   row-level security policy.
+   row-level security policy.  Note that <command>ALTER POLICY</command>
+   only allows the set of roles to which the policy applies and the
+   <literal>USING</literal> and <literal>WITH CHECK</literal> expressions to
+   be modified.  To change other properties of a policy, such as the command
+   to which it applies or whether it is permissive or restrictive, the policy
+   must be dropped and recreated.
   </para>
 
   <para>

doc/src/sgml/ref/create_policy.sgml

@@ -22,6 +22,7 @@ PostgreSQL documentation
  <refsynopsisdiv>
 <synopsis>
 CREATE POLICY <replaceable class="parameter">name</replaceable> ON <replaceable class="parameter">table_name</replaceable>
+    [ AS { PERMISSIVE | RESTRICTIVE } ]
     [ FOR { ALL | SELECT | INSERT | UPDATE | DELETE } ]
     [ TO { <replaceable class="parameter">role_name</replaceable> | PUBLIC | CURRENT_USER | SESSION_USER } [, ...] ]
     [ USING ( <replaceable class="parameter">using_expression</replaceable> ) ]
@@ -119,6 +120,33 @@ CREATE POLICY <replaceable class="parameter">name</replaceable> ON <replaceable
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term><replaceable class="parameter">PERMISSIVE</replaceable></term>
+    <listitem>
+     <para>
+      Specify that the policy is to be created as a permissive policy.
+      All permissive policies which are applicable to a given query will
+      be combined together using the boolean "OR" operator.  By creating
+      permissive policies, administrators can add to the set of records
+      which can be accessed.  Policies are PERMISSIVE by default.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term><replaceable class="parameter">RESTRICTIVE</replaceable></term>
+    <listitem>
+     <para>
+      Specify that the policy is to be created as a restrictive policy.
+      All restrictive policies which are applicable to a given query will
+      be combined together using the boolean "AND" operator.  By creating
+      restrictive policies, administrators can reduce the set of records
+      which can be accessed as all restrictive policies must be passed for
+      each record.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><replaceable class="parameter">command</replaceable></term>
     <listitem>
@@ -390,6 +418,16 @@ CREATE POLICY <replaceable class="parameter">name</replaceable> ON <replaceable
    keys) instead of keys with external meanings.
   </para>
 
+  <para>
+   Note that there needs to be at least one permissive policy to grant
+   access to records before restrictive policies can be usefully used to
+   reduce that access. If only restrictive policies exist, then no records
+   will be accessible. When a mix of permissive and restrictive policies
+   are present, a record is only accessible if at least one of the
+   permissive policies passes, in addition to all the restrictive
+   policies.
+  </para>
+
   <para>
    Generally, the system will enforce filter conditions imposed using
    security policies prior to qualifications that appear in user queries,

src/backend/catalog/system_views.sql

@@ -75,6 +75,12 @@ CREATE VIEW pg_policies AS
         N.nspname AS schemaname,
         C.relname AS tablename,
         pol.polname AS policyname,
+        CASE
+            WHEN pol.polpermissive THEN
+                'PERMISSIVE'
+            ELSE
+                'RESTRICTIVE'
+        END AS permissive,
         CASE
             WHEN pol.polroles = '{0}' THEN
                 string_to_array('public', '')

src/backend/commands/policy.c

@@ -235,6 +235,7 @@ RelationBuildRowSecurity(Relation relation)
 		{
 			Datum		value_datum;
 			char		cmd_value;
+			bool		permissive_value;
 			Datum		roles_datum;
 			char	   *qual_value;
 			Expr	   *qual_expr;
@@ -257,6 +258,12 @@ RelationBuildRowSecurity(Relation relation)
 			Assert(!isnull);
 			cmd_value = DatumGetChar(value_datum);
 
+			/* Get policy permissive or restrictive */
+			value_datum = heap_getattr(tuple, Anum_pg_policy_polpermissive,
+									   RelationGetDescr(catalog), &isnull);
+			Assert(!isnull);
+			permissive_value = DatumGetBool(value_datum);
+
 			/* Get policy name */
 			value_datum = heap_getattr(tuple, Anum_pg_policy_polname,
 									   RelationGetDescr(catalog), &isnull);
@@ -298,6 +305,7 @@ RelationBuildRowSecurity(Relation relation)
 			policy = palloc0(sizeof(RowSecurityPolicy));
 			policy->policy_name = pstrdup(policy_name_value);
 			policy->polcmd = cmd_value;
+			policy->permissive = permissive_value;
 			policy->roles = DatumGetArrayTypePCopy(roles_datum);
 			policy->qual = copyObject(qual_expr);
 			policy->with_check_qual = copyObject(with_check_qual);
@@ -796,6 +804,7 @@ CreatePolicy(CreatePolicyStmt *stmt)
 	values[Anum_pg_policy_polname - 1] = DirectFunctionCall1(namein,
 										 CStringGetDatum(stmt->policy_name));
 	values[Anum_pg_policy_polcmd - 1] = CharGetDatum(polcmd);
+	values[Anum_pg_policy_polpermissive - 1] = BoolGetDatum(stmt->permissive);
 	values[Anum_pg_policy_polroles - 1] = PointerGetDatum(role_ids);
 
 	/* Add qual if present. */

src/backend/nodes/copyfuncs.c

@@ -4166,6 +4166,7 @@ _copyCreatePolicyStmt(const CreatePolicyStmt *from)
 	COPY_STRING_FIELD(policy_name);
 	COPY_NODE_FIELD(table);
 	COPY_STRING_FIELD(cmd_name);
+	COPY_SCALAR_FIELD(permissive);
 	COPY_NODE_FIELD(roles);
 	COPY_NODE_FIELD(qual);
 	COPY_NODE_FIELD(with_check);

src/backend/nodes/equalfuncs.c

@@ -2125,6 +2125,7 @@ _equalCreatePolicyStmt(const CreatePolicyStmt *a, const CreatePolicyStmt *b)
 	COMPARE_STRING_FIELD(policy_name);
 	COMPARE_NODE_FIELD(table);
 	COMPARE_STRING_FIELD(cmd_name);
+	COMPARE_SCALAR_FIELD(permissive);
 	COMPARE_NODE_FIELD(roles);
 	COMPARE_NODE_FIELD(qual);
 	COMPARE_NODE_FIELD(with_check);

src/backend/parser/gram.y

@@ -332,6 +332,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <str>		all_Op MathOp
 
 %type <str>		row_security_cmd RowSecurityDefaultForCmd
+%type <boolean> RowSecurityDefaultPermissive
 %type <node>	RowSecurityOptionalWithCheck RowSecurityOptionalExpr
 %type <list>	RowSecurityDefaultToRole RowSecurityOptionalToRole
 
@@ -4628,26 +4629,30 @@ AlterUserMappingStmt: ALTER USER MAPPING FOR auth_ident SERVER name alter_generi
 /*****************************************************************************
  *
  *		QUERIES:
- *				CREATE POLICY name ON table [FOR cmd] [TO role, ...]
- *					[USING (qual)] [WITH CHECK (with_check)]
+ *				CREATE POLICY name ON table
+ *					[AS { PERMISSIVE | RESTRICTIVE } ]
+ *					[FOR { SELECT | INSERT | UPDATE | DELETE } ]
+ *					[TO role, ...]
+ *					[USING (qual)] [WITH CHECK (with check qual)]
  *				ALTER POLICY name ON table [TO role, ...]
- *					[USING (qual)] [WITH CHECK (with_check)]
+ *					[USING (qual)] [WITH CHECK (with check qual)]
  *				DROP POLICY name ON table
  *
  *****************************************************************************/
 
 CreatePolicyStmt:
-			CREATE POLICY name ON qualified_name RowSecurityDefaultForCmd
-				RowSecurityDefaultToRole RowSecurityOptionalExpr
-				RowSecurityOptionalWithCheck
+			CREATE POLICY name ON qualified_name RowSecurityDefaultPermissive
+				RowSecurityDefaultForCmd RowSecurityDefaultToRole
+				RowSecurityOptionalExpr RowSecurityOptionalWithCheck
 				{
 					CreatePolicyStmt *n = makeNode(CreatePolicyStmt);
 					n->policy_name = $3;
 					n->table = $5;
-					n->cmd_name = $6;
-					n->roles = $7;
-					n->qual = $8;
-					n->with_check = $9;
+					n->permissive = $6;
+					n->cmd_name = $7;
+					n->roles = $8;
+					n->qual = $9;
+					n->with_check = $10;
 					$$ = (Node *) n;
 				}
 		;
@@ -4711,6 +4716,24 @@ RowSecurityOptionalToRole:
 			| /* EMPTY */			{ $$ = NULL; }
 		;
 
+RowSecurityDefaultPermissive:
+			AS IDENT
+				{
+					if (strcmp($2, "permissive") == 0)
+						$$ = true;
+					else if (strcmp($2, "restrictive") == 0)
+						$$ = false;
+					else
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("unrecognized row security option \"%s\"", $2),
+								 errhint("Only PERMISSIVE or RESTRICTIVE policies are supported currently."),
+									 parser_errposition(@2)));
+
+				}
+			| /* EMPTY */			{ $$ = true; }
+		;
+
 RowSecurityDefaultForCmd:
 			FOR row_security_cmd	{ $$ = $2; }
 			| /* EMPTY */			{ $$ = "all"; }

src/backend/rewrite/rowsecurity.c

@@ -86,10 +86,10 @@ static bool check_role_for_policy(ArrayType *policy_roles, Oid user_id);
  * hooks to allow extensions to add their own security policies
  *
  * row_security_policy_hook_permissive can be used to add policies which
- * are included in the "OR"d set of policies.
+ * are combined with the other permissive policies, using OR.
  *
  * row_security_policy_hook_restrictive can be used to add policies which
- * are enforced, regardless of other policies (they are "AND"d).
+ * are enforced, regardless of other policies (they are combined using AND).
  */
 row_security_policy_hook_type row_security_policy_hook_permissive = NULL;
 row_security_policy_hook_type row_security_policy_hook_restrictive = NULL;
@@ -212,8 +212,8 @@ get_row_security_policies(Query *root, RangeTblEntry *rte, int rt_index,
 	/*
 	 * For SELECT, UPDATE and DELETE, add security quals to enforce the USING
 	 * policies.  These security quals control access to existing table rows.
-	 * Restrictive policies are "AND"d together, and permissive policies are
-	 * "OR"d together.
+	 * Restrictive policies are combined together using AND, and permissive
+	 * policies are combined together using OR.
 	 */
 
 	get_policies_for_relation(rel, commandType, user_id, &permissive_policies,
@@ -433,9 +433,20 @@ get_policies_for_relation(Relation relation, CmdType cmd, Oid user_id,
 		 * the specified role.
 		 */
 		if (cmd_matches && check_role_for_policy(policy->roles, user_id))
-			*permissive_policies = lappend(*permissive_policies, policy);
+		{
+			if (policy->permissive)
+				*permissive_policies = lappend(*permissive_policies, policy);
+			else
+				*restrictive_policies = lappend(*restrictive_policies, policy);
+		}
 	}
 
+	/*
+	 * We sort restrictive policies by name so that any WCOs they generate are
+	 * checked in a well-defined order.
+	 */
+	*restrictive_policies = sort_policies_by_name(*restrictive_policies);
+
 	/*
 	 * Then add any permissive or restrictive policies defined by extensions.
 	 * These are simply appended to the lists of internal policies, if they
@@ -447,8 +458,10 @@ get_policies_for_relation(Relation relation, CmdType cmd, Oid user_id,
 		(*row_security_policy_hook_restrictive) (cmd, relation);
 
 		/*
-		 * We sort restrictive policies by name so that any WCOs they generate
-		 * are checked in a well-defined order.
+		 * As with built-in restrictive policies, we sort any hook-provided
+		 * restrictive policies by name also.  Note that we also intentionally
+		 * always check all built-in restrictive policies, in name order,
+		 * before checking restrictive policies added by hooks, in name order.
 		 */
 		hook_policies = sort_policies_by_name(hook_policies);
 
@@ -481,8 +494,8 @@ get_policies_for_relation(Relation relation, CmdType cmd, Oid user_id,
  *
  * This is only used for restrictive policies, ensuring that any
  * WithCheckOptions they generate are applied in a well-defined order.
- * This is not necessary for permissive policies, since they are all "OR"d
- * together into a single WithCheckOption check.
+ * This is not necessary for permissive policies, since they are all combined
+ * together using OR into a single WithCheckOption check.
  */
 static List *
 sort_policies_by_name(List *policies)
@@ -580,8 +593,8 @@ add_security_quals(int rt_index,
 		/*
 		 * We now know that permissive policies exist, so we can now add
 		 * security quals based on the USING clauses from the restrictive
-		 * policies.  Since these need to be "AND"d together, we can just add
-		 * them one at a time.
+		 * policies.  Since these need to be combined together using AND, we
+		 * can just add them one at a time.
 		 */
 		foreach(item, restrictive_policies)
 		{
@@ -599,8 +612,8 @@ add_security_quals(int rt_index,
 		}
 
 		/*
-		 * Then add a single security qual "OR"ing together the USING clauses
-		 * from all the permissive policies.
+		 * Then add a single security qual combining together the USING
+		 * clauses from all the permissive policies using OR.
 		 */
 		if (list_length(permissive_quals) == 1)
 			rowsec_expr = (Expr *) linitial(permissive_quals);
@@ -681,10 +694,11 @@ add_with_check_options(Relation rel,
 	if (permissive_quals != NIL)
 	{
 		/*
-		 * Add a single WithCheckOption for all the permissive policy clauses
-		 * "OR"d together.  This check has no policy name, since if the check
-		 * fails it means that no policy granted permission to perform the
-		 * update, rather than any particular policy being violated.
+		 * Add a single WithCheckOption for all the permissive policy clauses,
+		 * combining them together using OR.  This check has no policy name,
+		 * since if the check fails it means that no policy granted permission
+		 * to perform the update, rather than any particular policy being
+		 * violated.
 		 */
 		WithCheckOption *wco;
 
@@ -705,9 +719,9 @@ add_with_check_options(Relation rel,
 
 		/*
 		 * Now add WithCheckOptions for each of the restrictive policy clauses
-		 * (which will be "AND"d together).  We use a separate WithCheckOption
-		 * for each restrictive policy to allow the policy name to be included
-		 * in error reports if the policy is violated.
+		 * (which will be combined together using AND).  We use a separate
+		 * WithCheckOption for each restrictive policy to allow the policy
+		 * name to be included in error reports if the policy is violated.
 		 */
 		foreach(item, restrictive_policies)
 		{

src/bin/pg_dump/pg_dump.c

@@ -3037,6 +3037,7 @@ getPolicies(Archive *fout, TableInfo tblinfo[], int numTables)
 	int			i_tableoid;
 	int			i_polname;
 	int			i_polcmd;
+	int			i_polpermissive;
 	int			i_polroles;
 	int			i_polqual;
 	int			i_polwithcheck;
@@ -3082,7 +3083,8 @@ getPolicies(Archive *fout, TableInfo tblinfo[], int numTables)
 			polinfo->dobj.name = pg_strdup(tbinfo->dobj.name);
 			polinfo->poltable = tbinfo;
 			polinfo->polname = NULL;
-			polinfo->polcmd = NULL;
+			polinfo->polcmd = '\0';
+			polinfo->polpermissive = 0;
 			polinfo->polroles = NULL;
 			polinfo->polqual = NULL;
 			polinfo->polwithcheck = NULL;
@@ -3101,15 +3103,26 @@ getPolicies(Archive *fout, TableInfo tblinfo[], int numTables)
 		resetPQExpBuffer(query);
 
 		/* Get the policies for the table. */
-		appendPQExpBuffer(query,
-						  "SELECT oid, tableoid, pol.polname, pol.polcmd, "
-						  "CASE WHEN pol.polroles = '{0}' THEN 'PUBLIC' ELSE "
-						  "   pg_catalog.array_to_string(ARRAY(SELECT pg_catalog.quote_ident(rolname) from pg_catalog.pg_roles WHERE oid = ANY(pol.polroles)), ', ') END AS polroles, "
-			 "pg_catalog.pg_get_expr(pol.polqual, pol.polrelid) AS polqual, "
-						  "pg_catalog.pg_get_expr(pol.polwithcheck, pol.polrelid) AS polwithcheck "
-						  "FROM pg_catalog.pg_policy pol "
-						  "WHERE polrelid = '%u'",
-						  tbinfo->dobj.catId.oid);
+		if (fout->remoteVersion >= 100000)
+			appendPQExpBuffer(query,
+							  "SELECT oid, tableoid, pol.polname, pol.polcmd, pol.polpermissive, "
+							  "CASE WHEN pol.polroles = '{0}' THEN NULL ELSE "
+							  "   pg_catalog.array_to_string(ARRAY(SELECT pg_catalog.quote_ident(rolname) from pg_catalog.pg_roles WHERE oid = ANY(pol.polroles)), ', ') END AS polroles, "
+				 "pg_catalog.pg_get_expr(pol.polqual, pol.polrelid) AS polqual, "
+							  "pg_catalog.pg_get_expr(pol.polwithcheck, pol.polrelid) AS polwithcheck "
+							  "FROM pg_catalog.pg_policy pol "
+							  "WHERE polrelid = '%u'",
+							  tbinfo->dobj.catId.oid);
+		else
+			appendPQExpBuffer(query,
+							  "SELECT oid, tableoid, pol.polname, pol.polcmd, 't' as polpermissive, "
+							  "CASE WHEN pol.polroles = '{0}' THEN NULL ELSE "
+							  "   pg_catalog.array_to_string(ARRAY(SELECT pg_catalog.quote_ident(rolname) from pg_catalog.pg_roles WHERE oid = ANY(pol.polroles)), ', ') END AS polroles, "
+				 "pg_catalog.pg_get_expr(pol.polqual, pol.polrelid) AS polqual, "
+							  "pg_catalog.pg_get_expr(pol.polwithcheck, pol.polrelid) AS polwithcheck "
+							  "FROM pg_catalog.pg_policy pol "
+							  "WHERE polrelid = '%u'",
+							  tbinfo->dobj.catId.oid);
 		res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
 
 		ntups = PQntuples(res);
@@ -3129,6 +3142,7 @@ getPolicies(Archive *fout, TableInfo tblinfo[], int numTables)
 		i_tableoid = PQfnumber(res, "tableoid");
 		i_polname = PQfnumber(res, "polname");
 		i_polcmd = PQfnumber(res, "polcmd");
+		i_polpermissive = PQfnumber(res, "polpermissive");
 		i_polroles = PQfnumber(res, "polroles");
 		i_polqual = PQfnumber(res, "polqual");
 		i_polwithcheck = PQfnumber(res, "polwithcheck");
@@ -3147,8 +3161,13 @@ getPolicies(Archive *fout, TableInfo tblinfo[], int numTables)
 			polinfo[j].polname = pg_strdup(PQgetvalue(res, j, i_polname));
 			polinfo[j].dobj.name = pg_strdup(polinfo[j].polname);
 
-			polinfo[j].polcmd = pg_strdup(PQgetvalue(res, j, i_polcmd));
-			polinfo[j].polroles = pg_strdup(PQgetvalue(res, j, i_polroles));
+			polinfo[j].polcmd = *(PQgetvalue(res, j, i_polcmd));
+			polinfo[j].polpermissive = *(PQgetvalue(res, j, i_polpermissive)) == 't';
+
+			if (PQgetisnull(res, j, i_polroles))
+				polinfo[j].polroles = NULL;
+			else
+				polinfo[j].polroles = pg_strdup(PQgetvalue(res, j, i_polroles));
 
 			if (PQgetisnull(res, j, i_polqual))
 				polinfo[j].polqual = NULL;
@@ -3210,19 +3229,19 @@ dumpPolicy(Archive *fout, PolicyInfo *polinfo)
 		return;
 	}
 
-	if (strcmp(polinfo->polcmd, "*") == 0)
-		cmd = "ALL";
-	else if (strcmp(polinfo->polcmd, "r") == 0)
-		cmd = "SELECT";
-	else if (strcmp(polinfo->polcmd, "a") == 0)
-		cmd = "INSERT";
-	else if (strcmp(polinfo->polcmd, "w") == 0)
-		cmd = "UPDATE";
-	else if (strcmp(polinfo->polcmd, "d") == 0)
-		cmd = "DELETE";
+	if (polinfo->polcmd == '*')
+		cmd = "";
+	else if (polinfo->polcmd == 'r')
+		cmd = " FOR SELECT";
+	else if (polinfo->polcmd == 'a')
+		cmd = " FOR INSERT";
+	else if (polinfo->polcmd == 'w')
+		cmd = " FOR UPDATE";
+	else if (polinfo->polcmd == 'd')
+		cmd = " FOR DELETE";
 	else
 	{
-		write_msg(NULL, "unexpected policy command type: \"%s\"\n",
+		write_msg(NULL, "unexpected policy command type: %c\n",
 				  polinfo->polcmd);
 		exit_nicely(1);
 	}
@@ -3231,7 +3250,9 @@ dumpPolicy(Archive *fout, PolicyInfo *polinfo)
 	delqry = createPQExpBuffer();
 
 	appendPQExpBuffer(query, "CREATE POLICY %s", fmtId(polinfo->polname));
-	appendPQExpBuffer(query, " ON %s FOR %s", fmtId(tbinfo->dobj.name), cmd);
+
+	appendPQExpBuffer(query, " ON %s%s%s", fmtId(tbinfo->dobj.name),
+					  !polinfo->polpermissive ? " AS RESTRICTIVE" : "", cmd);
 
 	if (polinfo->polroles != NULL)
 		appendPQExpBuffer(query, " TO %s", polinfo->polroles);

src/bin/pg_dump/pg_dump.h

@@ -547,7 +547,8 @@ typedef struct _policyInfo
 	DumpableObject dobj;
 	TableInfo  *poltable;
 	char	   *polname;		/* null indicates RLS is enabled on rel */
-	char	   *polcmd;
+	char		polcmd;
+	bool		polpermissive;
 	char	   *polroles;
 	char	   *polqual;
 	char	   *polwithcheck;

src/bin/pg_dump/t/002_pg_dump.pl

@@ -2004,7 +2004,7 @@ my %tests = (
 						   USING (true)
 						   WITH CHECK (true);',
 		regexp => qr/^
-			\QCREATE POLICY p1 ON test_table FOR ALL TO PUBLIC \E
+			\QCREATE POLICY p1 ON test_table \E
 			\QUSING (true) WITH CHECK (true);\E
 			/xm,
 		like => {
@@ -2166,7 +2166,36 @@ my %tests = (
 			pg_dumpall_globals_clean => 1,
 			role                     => 1,
 			section_pre_data         => 1, }, },
-
+	'CREATE POLICY p6 ON test_table AS RESTRICTIVE' => {
+		create_order => 27,
+		create_sql   => 'CREATE POLICY p6 ON dump_test.test_table AS RESTRICTIVE
+						   USING (false);',
+		regexp => qr/^
+			\QCREATE POLICY p6 ON test_table AS RESTRICTIVE \E
+			\QUSING (false);\E
+			/xm,
+		like => {
+			binary_upgrade          => 1,
+			clean                   => 1,
+			clean_if_exists         => 1,
+			createdb                => 1,
+			defaults                => 1,
+			exclude_test_table_data => 1,
+			no_privs                => 1,
+			no_owner                => 1,
+			only_dump_test_schema   => 1,
+			only_dump_test_table    => 1,
+			pg_dumpall_dbprivs      => 1,
+			schema_only             => 1,
+			section_post_data       => 1,
+			test_schema_plus_blobs  => 1, },
+		unlike => {
+			exclude_dump_test_schema => 1,
+			exclude_test_table       => 1,
+			pg_dumpall_globals       => 1,
+			pg_dumpall_globals_clean => 1,
+			role                     => 1,
+		    section_pre_data         => 1, }, },
 	'CREATE SCHEMA dump_test' => {
 		all_runs => 1,
 		catch_all => 'CREATE ... commands',

src/bin/psql/describe.c

@@ -887,10 +887,44 @@ permissionsList(const char *pattern)
 						  "  ), E'\\n') AS \"%s\"",
 						  gettext_noop("Column privileges"));
 
-	if (pset.sversion >= 90500)
+	if (pset.sversion >= 90500 && pset.sversion < 100000)
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.array_to_string(ARRAY(\n"
+						  "    SELECT polname\n"
+						  "    || CASE WHEN polcmd != '*' THEN\n"
+						  "           E' (' || polcmd || E'):'\n"
+						  "       ELSE E':' \n"
+						  "       END\n"
+						  "    || CASE WHEN polqual IS NOT NULL THEN\n"
+						  "           E'\\n  (u): ' || pg_catalog.pg_get_expr(polqual, polrelid)\n"
+						  "       ELSE E''\n"
+						  "       END\n"
+						  "    || CASE WHEN polwithcheck IS NOT NULL THEN\n"
+						  "           E'\\n  (c): ' || pg_catalog.pg_get_expr(polwithcheck, polrelid)\n"
+						  "       ELSE E''\n"
+						  "       END"
+						  "    || CASE WHEN polroles <> '{0}' THEN\n"
+				   "           E'\\n  to: ' || pg_catalog.array_to_string(\n"
+						  "               ARRAY(\n"
+						  "                   SELECT rolname\n"
+						  "                   FROM pg_catalog.pg_roles\n"
+						  "                   WHERE oid = ANY (polroles)\n"
+						  "                   ORDER BY 1\n"
+						  "               ), E', ')\n"
+						  "       ELSE E''\n"
+						  "       END\n"
+						  "    FROM pg_catalog.pg_policy pol\n"
+						  "    WHERE polrelid = c.oid), E'\\n')\n"
+						  "    AS \"%s\"",
+						  gettext_noop("Policies"));
+
+	if (pset.sversion >= 100000)
 		appendPQExpBuffer(&buf,
 						  ",\n  pg_catalog.array_to_string(ARRAY(\n"
 						  "    SELECT polname\n"
+						  "    || CASE WHEN NOT polpermissive THEN\n"
+						  "       E' (RESTRICTIVE)'\n"
+						  "       ELSE '' END\n"
 						  "    || CASE WHEN polcmd != '*' THEN\n"
 						  "           E' (' || polcmd || E'):'\n"
 						  "       ELSE E':' \n"
@@ -2112,21 +2146,36 @@ describeOneTableDetails(const char *schemaname,
 		/* print any row-level policies */
 		if (pset.sversion >= 90500)
 		{
-			printfPQExpBuffer(&buf,
-							  "SELECT pol.polname,\n"
-							  "CASE WHEN pol.polroles = '{0}' THEN NULL ELSE array_to_string(array(select rolname from pg_roles where oid = any (pol.polroles) order by 1),',') END,\n"
-					   "pg_catalog.pg_get_expr(pol.polqual, pol.polrelid),\n"
-				  "pg_catalog.pg_get_expr(pol.polwithcheck, pol.polrelid),\n"
-							  "CASE pol.polcmd \n"
-							  "WHEN 'r' THEN 'SELECT'\n"
-							  "WHEN 'a' THEN 'INSERT'\n"
-							  "WHEN 'w' THEN 'UPDATE'\n"
-							  "WHEN 'd' THEN 'DELETE'\n"
-							  "WHEN '*' THEN 'ALL'\n"
-							  "END AS cmd\n"
-							  "FROM pg_catalog.pg_policy pol\n"
-							  "WHERE pol.polrelid = '%s' ORDER BY 1;",
-							  oid);
+			if (pset.sversion >= 100000)
+				printfPQExpBuffer(&buf,
+								  "SELECT pol.polname, pol.polpermissive,\n"
+								  "CASE WHEN pol.polroles = '{0}' THEN NULL ELSE array_to_string(array(select rolname from pg_roles where oid = any (pol.polroles) order by 1),',') END,\n"
+						   "pg_catalog.pg_get_expr(pol.polqual, pol.polrelid),\n"
+					  "pg_catalog.pg_get_expr(pol.polwithcheck, pol.polrelid),\n"
+								  "CASE pol.polcmd \n"
+								  "WHEN 'r' THEN 'SELECT'\n"
+								  "WHEN 'a' THEN 'INSERT'\n"
+								  "WHEN 'w' THEN 'UPDATE'\n"
+								  "WHEN 'd' THEN 'DELETE'\n"
+								  "END AS cmd\n"
+								  "FROM pg_catalog.pg_policy pol\n"
+								  "WHERE pol.polrelid = '%s' ORDER BY 1;",
+								  oid);
+			else
+				printfPQExpBuffer(&buf,
+								  "SELECT pol.polname, 't' as polpermissive,\n"
+								  "CASE WHEN pol.polroles = '{0}' THEN NULL ELSE array_to_string(array(select rolname from pg_roles where oid = any (pol.polroles) order by 1),',') END,\n"
+						   "pg_catalog.pg_get_expr(pol.polqual, pol.polrelid),\n"
+					  "pg_catalog.pg_get_expr(pol.polwithcheck, pol.polrelid),\n"
+								  "CASE pol.polcmd \n"
+								  "WHEN 'r' THEN 'SELECT'\n"
+								  "WHEN 'a' THEN 'INSERT'\n"
+								  "WHEN 'w' THEN 'UPDATE'\n"
+								  "WHEN 'd' THEN 'DELETE'\n"
+								  "END AS cmd\n"
+								  "FROM pg_catalog.pg_policy pol\n"
+								  "WHERE pol.polrelid = '%s' ORDER BY 1;",
+								  oid);
 
 			result = PSQLexec(buf.data);
 			if (!result)
@@ -2160,23 +2209,26 @@ describeOneTableDetails(const char *schemaname,
 				printfPQExpBuffer(&buf, "    POLICY \"%s\"",
 								  PQgetvalue(result, i, 0));
 
-				if (!PQgetisnull(result, i, 4))
+				if (*(PQgetvalue(result, i, 1)) == 'f')
+					appendPQExpBuffer(&buf, " AS RESTRICTIVE");
+
+				if (!PQgetisnull(result, i, 5))
 					appendPQExpBuffer(&buf, " FOR %s",
-									  PQgetvalue(result, i, 4));
+									  PQgetvalue(result, i, 5));
 
-				if (!PQgetisnull(result, i, 1))
+				if (!PQgetisnull(result, i, 2))
 				{
 					appendPQExpBuffer(&buf, "\n      TO %s",
-									  PQgetvalue(result, i, 1));
+									  PQgetvalue(result, i, 2));
 				}
 
-				if (!PQgetisnull(result, i, 2))
+				if (!PQgetisnull(result, i, 3))
 					appendPQExpBuffer(&buf, "\n      USING (%s)",
-									  PQgetvalue(result, i, 2));
+									  PQgetvalue(result, i, 3));
 
-				if (!PQgetisnull(result, i, 3))
+				if (!PQgetisnull(result, i, 4))
 					appendPQExpBuffer(&buf, "\n      WITH CHECK (%s)",
-									  PQgetvalue(result, i, 3));
+									  PQgetvalue(result, i, 4));
 
 				printTableAddFooter(&cont, buf.data);
 

src/bin/psql/tab-complete.c

@@ -2162,9 +2162,15 @@ psql_completion(const char *text, int start, int end)
 	/* Complete "CREATE POLICY <name> ON <table>" */
 	else if (Matches4("CREATE", "POLICY", MatchAny, "ON"))
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_tables, NULL);
-	/* Complete "CREATE POLICY <name> ON <table> FOR|TO|USING|WITH CHECK" */
+	/* Complete "CREATE POLICY <name> ON <table> AS|FOR|TO|USING|WITH CHECK" */
 	else if (Matches5("CREATE", "POLICY", MatchAny, "ON", MatchAny))
-		COMPLETE_WITH_LIST4("FOR", "TO", "USING (", "WITH CHECK (");
+		COMPLETE_WITH_LIST5("AS", "FOR", "TO", "USING (", "WITH CHECK (");
+	/* CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE */
+	else if (Matches6("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS"))
+		COMPLETE_WITH_LIST2("PERMISSIVE", "RESTRICTIVE");
+	/* CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE FOR|TO|USING|WITH CHECK */
+	else if (Matches7("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS", MatchAny))
+		COMPLETE_WITH_LIST4("FOR", "TO", "USING", "WITH CHECK");
 	/* CREATE POLICY <name> ON <table> FOR ALL|SELECT|INSERT|UPDATE|DELETE */
 	else if (Matches6("CREATE", "POLICY", MatchAny, "ON", MatchAny, "FOR"))
 		COMPLETE_WITH_LIST5("ALL", "SELECT", "INSERT", "UPDATE", "DELETE");
@@ -2183,6 +2189,25 @@ psql_completion(const char *text, int start, int end)
 	/* Complete "CREATE POLICY <name> ON <table> USING (" */
 	else if (Matches6("CREATE", "POLICY", MatchAny, "ON", MatchAny, "USING"))
 		COMPLETE_WITH_CONST("(");
+	/* CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE FOR ALL|SELECT|INSERT|UPDATE|DELETE */
+	else if (Matches8("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS", MatchAny, "FOR"))
+		COMPLETE_WITH_LIST5("ALL", "SELECT", "INSERT", "UPDATE", "DELETE");
+	/* Complete "CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE FOR INSERT TO|WITH CHECK" */
+	else if (Matches9("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS", MatchAny, "FOR", "INSERT"))
+		COMPLETE_WITH_LIST2("TO", "WITH CHECK (");
+	/* Complete "CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE FOR SELECT|DELETE TO|USING" */
+	else if (Matches9("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS", MatchAny, "FOR", "SELECT|DELETE"))
+		COMPLETE_WITH_LIST2("TO", "USING (");
+	/* CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE FOR ALL|UPDATE TO|USING|WITH CHECK */
+	else if (Matches9("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS", MatchAny, "FOR", "ALL|UPDATE"))
+		COMPLETE_WITH_LIST3("TO", "USING (", "WITH CHECK (");
+	/* Complete "CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE TO <role>" */
+	else if (Matches8("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS", MatchAny, "TO"))
+		COMPLETE_WITH_QUERY(Query_for_list_of_grant_roles);
+	/* Complete "CREATE POLICY <name> ON <table> AS PERMISSIVE|RESTRICTIVE USING (" */
+	else if (Matches8("CREATE", "POLICY", MatchAny, "ON", MatchAny, "AS", MatchAny, "USING"))
+		COMPLETE_WITH_CONST("(");
+
 
 /* CREATE RULE */
 	/* Complete "CREATE RULE <sth>" with "AS ON" */

src/include/catalog/pg_policy.h

@@ -23,6 +23,7 @@ CATALOG(pg_policy,3256)
 	NameData	polname;		/* Policy name. */
 	Oid			polrelid;		/* Oid of the relation with policy. */
 	char		polcmd;			/* One of ACL_*_CHR, or '*' for all */
+	bool		polpermissive;	/* restrictive or permissive policy */
 
 #ifdef CATALOG_VARLEN
 	Oid			polroles[1];	/* Roles associated with policy, not-NULL */
@@ -42,12 +43,13 @@ typedef FormData_pg_policy *Form_pg_policy;
  *		compiler constants for pg_policy
  * ----------------
  */
-#define Natts_pg_policy				6
-#define Anum_pg_policy_polname		1
-#define Anum_pg_policy_polrelid		2
-#define Anum_pg_policy_polcmd		3
-#define Anum_pg_policy_polroles		4
-#define Anum_pg_policy_polqual		5
-#define Anum_pg_policy_polwithcheck 6
+#define Natts_pg_policy					7
+#define Anum_pg_policy_polname			1
+#define Anum_pg_policy_polrelid			2
+#define Anum_pg_policy_polcmd			3
+#define Anum_pg_policy_polpermissive	4
+#define Anum_pg_policy_polroles			5
+#define Anum_pg_policy_polqual			6
+#define Anum_pg_policy_polwithcheck 	7
 
 #endif   /* PG_POLICY_H */

src/include/nodes/parsenodes.h

@@ -2077,6 +2077,7 @@ typedef struct CreatePolicyStmt
 	char	   *policy_name;	/* Policy's name */
 	RangeVar   *table;			/* the table name the policy applies to */
 	char	   *cmd_name;		/* the command name the policy applies to */
+	bool		permissive;		/* restrictive or permissive policy */
 	List	   *roles;			/* the roles associated with the policy */
 	Node	   *qual;			/* the policy's condition */
 	Node	   *with_check;		/* the policy's WITH CHECK condition. */

src/include/rewrite/rowsecurity.h

@@ -22,6 +22,7 @@ typedef struct RowSecurityPolicy
 	char	   *policy_name;	/* Name of the policy */
 	char		polcmd;			/* Type of command policy is for */
 	ArrayType  *roles;			/* Array of roles policy is for */
+	bool		permissive;		/* restrictive or permissive policy */
 	Expr	   *qual;			/* Expression to filter rows */
 	Expr	   *with_check_qual;	/* Expression to limit rows allowed */
 	bool		hassublinks;	/* If either expression has sublinks */

src/test/regress/expected/rules.out

@@ -1379,6 +1379,10 @@ pg_matviews| SELECT n.nspname AS schemaname,
 pg_policies| SELECT n.nspname AS schemaname,
     c.relname AS tablename,
     pol.polname AS policyname,
+        CASE
+            WHEN pol.polpermissive THEN 'PERMISSIVE'::text
+            ELSE 'RESTRICTIVE'::text
+        END AS permissive,
         CASE
             WHEN (pol.polroles = '{0}'::oid[]) THEN (string_to_array('public'::text, ''::text))::name[]
             ELSE ARRAY( SELECT pg_authid.rolname

src/test/regress/sql/rowsecurity.sql

@@ -10,6 +10,7 @@ SET client_min_messages TO 'warning';
 DROP USER IF EXISTS regress_rls_alice;
 DROP USER IF EXISTS regress_rls_bob;
 DROP USER IF EXISTS regress_rls_carol;
+DROP USER IF EXISTS regress_rls_dave;
 DROP USER IF EXISTS regress_rls_exempt_user;
 DROP ROLE IF EXISTS regress_rls_group1;
 DROP ROLE IF EXISTS regress_rls_group2;
@@ -22,6 +23,7 @@ RESET client_min_messages;
 CREATE USER regress_rls_alice NOLOGIN;
 CREATE USER regress_rls_bob NOLOGIN;
 CREATE USER regress_rls_carol NOLOGIN;
+CREATE USER regress_rls_dave NOLOGIN;
 CREATE USER regress_rls_exempt_user BYPASSRLS NOLOGIN;
 CREATE ROLE regress_rls_group1 NOLOGIN;
 CREATE ROLE regress_rls_group2 NOLOGIN;
@@ -80,14 +82,35 @@ INSERT INTO document VALUES
     ( 5, 44, 2, 'regress_rls_bob', 'my second manga'),
     ( 6, 22, 1, 'regress_rls_carol', 'great science fiction'),
     ( 7, 33, 2, 'regress_rls_carol', 'great technology book'),
-    ( 8, 44, 1, 'regress_rls_carol', 'great manga');
+    ( 8, 44, 1, 'regress_rls_carol', 'great manga'),
+    ( 9, 22, 1, 'regress_rls_dave', 'awesome science fiction'),
+    (10, 33, 2, 'regress_rls_dave', 'awesome technology book');
 
 ALTER TABLE document ENABLE ROW LEVEL SECURITY;
 
 -- user's security level must be higher than or equal to document's
-CREATE POLICY p1 ON document
+CREATE POLICY p1 ON document AS PERMISSIVE
     USING (dlevel <= (SELECT seclv FROM uaccount WHERE pguser = current_user));
 
+-- try to create a policy of bogus type
+CREATE POLICY p1 ON document AS UGLY
+    USING (dlevel <= (SELECT seclv FROM uaccount WHERE pguser = current_user));
+
+-- but Dave isn't allowed to anything at cid 50 or above
+-- this is to make sure that we sort the policies by name first
+-- when applying WITH CHECK, a later INSERT by Dave should fail due
+-- to p1r first
+CREATE POLICY p2r ON document AS RESTRICTIVE TO regress_rls_dave
+    USING (cid <> 44 AND cid < 50);
+
+-- and Dave isn't allowed to see manga documents
+CREATE POLICY p1r ON document AS RESTRICTIVE TO regress_rls_dave
+    USING (cid <> 44);
+
+\dp
+\d document
+SELECT * FROM pg_policies WHERE schemaname = 'regress_rls_schema' AND tablename = 'document' ORDER BY policyname;
+
 -- viewpoint from regress_rls_bob
 SET SESSION AUTHORIZATION regress_rls_bob;
 SET row_security TO ON;
@@ -110,6 +133,20 @@ SELECT * FROM document TABLESAMPLE BERNOULLI(50) REPEATABLE(0)
 EXPLAIN (COSTS OFF) SELECT * FROM document WHERE f_leak(dtitle);
 EXPLAIN (COSTS OFF) SELECT * FROM document NATURAL JOIN category WHERE f_leak(dtitle);
 
+-- viewpoint from regress_rls_dave
+SET SESSION AUTHORIZATION regress_rls_dave;
+SELECT * FROM document WHERE f_leak(dtitle) ORDER BY did;
+SELECT * FROM document NATURAL JOIN category WHERE f_leak(dtitle) ORDER BY did;
+
+EXPLAIN (COSTS OFF) SELECT * FROM document WHERE f_leak(dtitle);
+EXPLAIN (COSTS OFF) SELECT * FROM document NATURAL JOIN category WHERE f_leak(dtitle);
+
+-- 44 would technically fail for both p2r and p1r, but we should get an error
+-- back from p1r for this because it sorts first
+INSERT INTO document VALUES (100, 44, 1, 'regress_rls_dave', 'testing sorting of policies'); -- fail
+-- Just to see a p2r error
+INSERT INTO document VALUES (100, 55, 1, 'regress_rls_dave', 'testing sorting of policies'); -- fail
+
 -- only owner can change policies
 ALTER POLICY p1 ON document USING (true);    --fail
 DROP POLICY p1 ON document;                  --fail
@@ -147,7 +184,7 @@ DELETE FROM category WHERE cid = 33;    -- fails with FK violation
 -- can insert FK referencing invisible PK
 SET SESSION AUTHORIZATION regress_rls_carol;
 SELECT * FROM document d FULL OUTER JOIN category c on d.cid = c.cid;
-INSERT INTO document VALUES (10, 33, 1, current_user, 'hoge');
+INSERT INTO document VALUES (11, 33, 1, current_user, 'hoge');
 
 -- UNIQUE or PRIMARY KEY constraint violation DOES reveal presence of row
 SET SESSION AUTHORIZATION regress_rls_bob;
@@ -517,6 +554,7 @@ SELECT * FROM b1;
 
 SET SESSION AUTHORIZATION regress_rls_alice;
 DROP POLICY p1 ON document;
+DROP POLICY p1r ON document;
 
 CREATE POLICY p1 ON document FOR SELECT USING (true);
 CREATE POLICY p2 ON document FOR INSERT WITH CHECK (dauthor = current_user);
@@ -1577,6 +1615,7 @@ RESET client_min_messages;
 DROP USER regress_rls_alice;
 DROP USER regress_rls_bob;
 DROP USER regress_rls_carol;
+DROP USER regress_rls_dave;
 DROP USER regress_rls_exempt_user;
 DROP ROLE regress_rls_group1;
 DROP ROLE regress_rls_group2;