Default monitoring roles

Three nologin roles with non-overlapping privs are created by default
* pg_read_all_settings - read all GUCs.
* pg_read_all_stats - pg_stat_*, pg_database_size(), pg_tablespace_size()
* pg_stat_scan_tables - may lock/scan tables

Top level role - pg_monitor includes all of the above by default, plus others

Author: Dave Page
Reviewed-by: Stephen Frost, Robert Haas, Peter Eisentraut, Simon Riggs

Author: simonat2ndQuadrant

contrib/pg_buffercache/Makefile

@@ -4,8 +4,9 @@ MODULE_big = pg_buffercache
 OBJS = pg_buffercache_pages.o $(WIN32RES)
 
 EXTENSION = pg_buffercache
-DATA = pg_buffercache--1.2.sql pg_buffercache--1.1--1.2.sql \
-	pg_buffercache--1.0--1.1.sql pg_buffercache--unpackaged--1.0.sql
+DATA = pg_buffercache--1.2.sql pg_buffercache--1.2--1.3.sql \
+	pg_buffercache--1.1--1.2.sql pg_buffercache--1.0--1.1.sql \
+	pg_buffercache--unpackaged--1.0.sql
 PGFILEDESC = "pg_buffercache - monitoring of shared buffer cache in real-time"
 
 ifdef USE_PGXS

contrib/pg_buffercache/pg_buffercache--1.2--1.3.sql

@@ -0,0 +1,7 @@
+/* contrib/pg_buffercache/pg_buffercache--1.2--1.3.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_buffercache UPDATE TO '1.3'" to load this file. \quit
+
+GRANT EXECUTE ON FUNCTION pg_buffercache_pages() TO pg_monitor;
+GRANT SELECT ON pg_buffercache TO pg_monitor;

contrib/pg_buffercache/pg_buffercache.control

@@ -1,5 +1,5 @@
 # pg_buffercache extension
 comment = 'examine the shared buffer cache'
-default_version = '1.2'
+default_version = '1.3'
 module_pathname = '$libdir/pg_buffercache'
 relocatable = true

contrib/pg_freespacemap/Makefile

@@ -4,8 +4,8 @@ MODULE_big = pg_freespacemap
 OBJS = pg_freespacemap.o $(WIN32RES)
 
 EXTENSION = pg_freespacemap
-DATA = pg_freespacemap--1.1.sql pg_freespacemap--1.0--1.1.sql \
-	pg_freespacemap--unpackaged--1.0.sql
+DATA = pg_freespacemap--1.1.sql pg_freespacemap--1.1--1.2.sql \
+	pg_freespacemap--1.0--1.1.sql pg_freespacemap--unpackaged--1.0.sql
 PGFILEDESC = "pg_freespacemap - monitoring of free space map"
 
 ifdef USE_PGXS

contrib/pg_freespacemap/pg_freespacemap--1.1--1.2.sql

@@ -0,0 +1,7 @@
+/* contrib/pg_freespacemap/pg_freespacemap--1.1--1.2.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_freespacemap UPDATE TO '1.2'" to load this file. \quit
+
+GRANT EXECUTE ON FUNCTION  pg_freespace(regclass, bigint) TO pg_stat_scan_tables;
+GRANT EXECUTE ON FUNCTION  pg_freespace(regclass) TO pg_stat_scan_tables;

contrib/pg_freespacemap/pg_freespacemap.control

@@ -1,5 +1,5 @@
 # pg_freespacemap extension
 comment = 'examine the free space map (FSM)'
-default_version = '1.1'
+default_version = '1.2'
 module_pathname = '$libdir/pg_freespacemap'
 relocatable = true

contrib/pg_stat_statements/Makefile

@@ -4,9 +4,10 @@ MODULE_big = pg_stat_statements
 OBJS = pg_stat_statements.o $(WIN32RES)
 
 EXTENSION = pg_stat_statements
-DATA = pg_stat_statements--1.4.sql pg_stat_statements--1.3--1.4.sql \
-	pg_stat_statements--1.2--1.3.sql pg_stat_statements--1.1--1.2.sql \
-	pg_stat_statements--1.0--1.1.sql pg_stat_statements--unpackaged--1.0.sql
+DATA = pg_stat_statements--1.4.sql pg_stat_statements--1.4--1.5.sql \
+	pg_stat_statements--1.3--1.4.sql pg_stat_statements--1.2--1.3.sql \
+	pg_stat_statements--1.1--1.2.sql pg_stat_statements--1.0--1.1.sql \
+	pg_stat_statements--unpackaged--1.0.sql
 PGFILEDESC = "pg_stat_statements - execution statistics of SQL statements"
 
 LDFLAGS_SL += $(filter -lm, $(LIBS))

contrib/pg_stat_statements/pg_stat_statements--1.4--1.5.sql

@@ -0,0 +1,6 @@
+/* contrib/pg_stat_statements/pg_stat_statements--1.4--1.5.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.5'" to load this file. \quit
+
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset() TO pg_read_all_stats;

contrib/pg_stat_statements/pg_stat_statements.c

@@ -62,6 +62,7 @@
 #include <unistd.h>
 
 #include "access/hash.h"
+#include "catalog/pg_authid.h"
 #include "executor/instrument.h"
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
@@ -1391,14 +1392,17 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 	MemoryContext per_query_ctx;
 	MemoryContext oldcontext;
 	Oid			userid = GetUserId();
-	bool		is_superuser = superuser();
+	bool		is_allowed_role = false;
 	char	   *qbuffer = NULL;
 	Size		qbuffer_size = 0;
 	Size		extent = 0;
 	int			gc_count = 0;
 	HASH_SEQ_STATUS hash_seq;
 	pgssEntry  *entry;
 
+	/* Superusers or members of pg_read_all_stats members are allowed */
+	is_allowed_role = is_member_of_role(GetUserId(), DEFAULT_ROLE_READ_ALL_STATS);
+
 	/* hash table must exist already */
 	if (!pgss || !pgss_hash)
 		ereport(ERROR,
@@ -1541,7 +1545,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 		values[i++] = ObjectIdGetDatum(entry->key.userid);
 		values[i++] = ObjectIdGetDatum(entry->key.dbid);
 
-		if (is_superuser || entry->key.userid == userid)
+		if (is_allowed_role || entry->key.userid == userid)
 		{
 			if (api_version >= PGSS_V1_2)
 				values[i++] = Int64GetDatumFast(queryid);

contrib/pg_stat_statements/pg_stat_statements.control

@@ -1,5 +1,5 @@
 # pg_stat_statements extension
 comment = 'track execution statistics of all SQL statements executed'
-default_version = '1.4'
+default_version = '1.5'
 module_pathname = '$libdir/pg_stat_statements'
 relocatable = true

contrib/pg_visibility/Makefile

@@ -4,7 +4,8 @@ MODULE_big = pg_visibility
 OBJS = pg_visibility.o $(WIN32RES)
 
 EXTENSION = pg_visibility
-DATA = pg_visibility--1.1.sql pg_visibility--1.0--1.1.sql
+DATA = pg_visibility--1.1.sql pg_visibility--1.1--1.2.sql \
+	pg_visibility--1.0--1.1.sql
 PGFILEDESC = "pg_visibility - page visibility information"
 
 REGRESS = pg_visibility

contrib/pg_visibility/pg_visibility--1.1--1.2.sql

@@ -0,0 +1,13 @@
+/* contrib/pg_visibility/pg_visibility--1.1--1.2.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_visibility UPDATE TO '1.2'" to load this file. \quit
+
+-- Allow use of monitoring functions by pg_monitor members
+GRANT EXECUTE ON FUNCTION pg_visibility_map(regclass, bigint) TO pg_stat_scan_tables;
+GRANT EXECUTE ON FUNCTION pg_visibility(regclass, bigint) TO pg_stat_scan_tables;
+GRANT EXECUTE ON FUNCTION pg_visibility_map(regclass) TO pg_stat_scan_tables;
+GRANT EXECUTE ON FUNCTION pg_visibility(regclass) TO pg_stat_scan_tables;
+GRANT EXECUTE ON FUNCTION pg_visibility_map_summary(regclass) TO pg_stat_scan_tables;
+GRANT EXECUTE ON FUNCTION pg_check_frozen(regclass) TO pg_stat_scan_tables;
+GRANT EXECUTE ON FUNCTION pg_check_visible(regclass) TO pg_stat_scan_tables;

contrib/pg_visibility/pg_visibility.control

@@ -1,5 +1,5 @@
 # pg_visibility extension
 comment = 'examine the visibility map (VM) and page-level visibility info'
-default_version = '1.1'
+default_version = '1.2'
 module_pathname = '$libdir/pg_visibility'
 relocatable = true

contrib/pgrowlocks/pgrowlocks.c

@@ -28,6 +28,7 @@
 #include "access/relscan.h"
 #include "access/xact.h"
 #include "catalog/namespace.h"
+#include "catalog/pg_authid.h"
 #include "funcapi.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
@@ -98,9 +99,11 @@ pgrowlocks(PG_FUNCTION_ARGS)
 		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
 		rel = heap_openrv(relrv, AccessShareLock);
 
-		/* check permissions: must have SELECT on table */
-		aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
-									  ACL_SELECT);
+		/* check permissions: must have SELECT on table or be in pg_stat_scan_tables */
+		aclresult = (pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
+									  ACL_SELECT) ||
+			is_member_of_role(GetUserId(), DEFAULT_ROLE_STAT_SCAN_TABLES);
+
 		if (aclresult != ACLCHECK_OK)
 			aclcheck_error(aclresult, ACL_KIND_CLASS,
 						   RelationGetRelationName(rel));

contrib/pgstattuple/pgstattuple--1.4--1.5.sql

@@ -17,6 +17,7 @@ AS 'MODULE_PATHNAME', 'pgstattuple_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pgstattuple(text) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pgstattuple(text) TO pg_stat_scan_tables;
 
 CREATE OR REPLACE FUNCTION pgstatindex(IN relname text,
     OUT version INT,
@@ -33,13 +34,15 @@ AS 'MODULE_PATHNAME', 'pgstatindex_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pgstatindex(text) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pgstatindex(text) TO pg_stat_scan_tables;
 
 CREATE OR REPLACE FUNCTION pg_relpages(IN relname text)
 RETURNS BIGINT
 AS 'MODULE_PATHNAME', 'pg_relpages_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pg_relpages(text) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pg_relpages(text) TO pg_stat_scan_tables;
 
 /* New stuff in 1.1 begins here */
 
@@ -51,6 +54,7 @@ AS 'MODULE_PATHNAME', 'pgstatginindex_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pgstatginindex(regclass) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pgstatginindex(regclass) TO pg_stat_scan_tables;
 
 /* New stuff in 1.2 begins here */
 
@@ -68,6 +72,7 @@ AS 'MODULE_PATHNAME', 'pgstattuplebyid_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pgstattuple(regclass) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pgstattuple(regclass) TO pg_stat_scan_tables;
 
 CREATE OR REPLACE FUNCTION pgstatindex(IN relname regclass,
     OUT version INT,
@@ -84,13 +89,15 @@ AS 'MODULE_PATHNAME', 'pgstatindexbyid_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pgstatindex(regclass) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pgstatindex(regclass) TO pg_stat_scan_tables;
 
 CREATE OR REPLACE FUNCTION pg_relpages(IN relname regclass)
 RETURNS BIGINT
 AS 'MODULE_PATHNAME', 'pg_relpagesbyid_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pg_relpages(regclass) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pg_relpages(regclass) TO pg_stat_scan_tables;
 
 /* New stuff in 1.3 begins here */
 
@@ -109,6 +116,7 @@ AS 'MODULE_PATHNAME', 'pgstattuple_approx_v1_5'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pgstattuple_approx(regclass) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pgstattuple_approx(regclass) TO pg_stat_scan_tables;
 
 /* New stuff in 1.5 begins here */
 
@@ -125,3 +133,4 @@ AS 'MODULE_PATHNAME', 'pgstathashindex'
 LANGUAGE C STRICT PARALLEL SAFE;
 
 REVOKE EXECUTE ON FUNCTION pgstathashindex(regclass) FROM PUBLIC;
+GRANT EXECUTE ON FUNCTION pgstathashindex(regclass) TO pg_stat_scan_tables;

doc/src/sgml/catalogs.sgml

@@ -10221,15 +10221,17 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       <entry><type>text</type></entry>
       <entry>Configuration file the current value was set in (null for
       values set from sources other than configuration files, or when
-      examined by a non-superuser);
-      helpful when using <literal>include</> directives in configuration files</entry>
+      examined by a user who is neither a superuser or a member of
+      <literal>pg_read_all_settings</literal>); helpful when using
+      <literal>include</> directives in configuration files</entry>
      </row>
      <row>
       <entry><structfield>sourceline</structfield></entry>
       <entry><type>integer</type></entry>
       <entry>Line number within the configuration file the current value was
       set at (null for values set from sources other than configuration files,
-      or when examined by a non-superuser)
+      or when examined by a user who is neither a superuser or a member of
+      <literal>pg_read_all_settings</literal>).
       </entry>
      </row>
      <row>

doc/src/sgml/func.sgml

@@ -19408,9 +19408,11 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
     accept the OID or name of a database or tablespace, and return the total
     disk space used therein.  To use <function>pg_database_size</function>,
     you must have <literal>CONNECT</> permission on the specified database
-    (which is granted by default).  To use <function>pg_tablespace_size</>,
-    you must have <literal>CREATE</> permission on the specified tablespace,
-    unless it is the default tablespace for the current database.
+    (which is granted by default), or be a member of the <literal>pg_read_all_stats</>
+    role. To use <function>pg_tablespace_size</>, you must have
+    <literal>CREATE</> permission on the specified tablespace, or be a member
+    of the <literal>pg_read_all_stats</> role unless it is the default tablespace for
+    the current database.
    </para>
 
    <para>
@@ -19736,7 +19738,8 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
        <entry><type>setof record</type></entry>
        <entry>
         List the name, size, and last modification time of files in the log
-        directory.  Access may be granted to non-superuser roles.
+        directory. Access is granted to members of the <literal>pg_monitor</>
+        role and may be granted to other non-superuser roles.
        </entry>
       </row>
       <row>
@@ -19746,7 +19749,8 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
        <entry><type>setof record</type></entry>
        <entry>
         List the name, size, and last modification time of files in the WAL
-        directory.  Access may be granted to non-superuser roles.
+        directory. Access is granted to members of the <literal>pg_monitor</>
+        role and may be granted to other non-superuser roles.
        </entry>
       </row>
       <row>
@@ -19807,8 +19811,8 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
    <para>
     <function>pg_ls_logdir</> returns the name, size, and last modified time
     (mtime) of each file in the log directory. By default, only superusers
-    can use this function, but access may be granted to others using
-    <command>GRANT</command>.
+    and members of the <literal>pg_monitor</> role can use this function.
+    Access may be granted to others using <command>GRANT</command>.
    </para>
 
    <indexterm>
@@ -19817,8 +19821,9 @@ postgres=# SELECT * FROM pg_walfile_name_offset(pg_stop_backup());
    <para>
     <function>pg_ls_waldir</> returns the name, size, and last modified time
     (mtime) of each file in the write ahead log (WAL) directory. By
-    default only superusers can use this function, but access may be granted
-    to others using <command>GRANT</command>.
+    default only superusers and members of the <literal>pg_monitor</> role
+    can use this function. Access may be granted to others using
+    <command>GRANT</command>.
    </para>
 
    <indexterm>

doc/src/sgml/pgbuffercache.sgml

@@ -24,8 +24,9 @@
  </para>
 
  <para>
-  By default public access is revoked from both of these, just in case there
-  are security issues lurking.
+  By default use is restricted to superusers and members of the
+  <literal>pg_read_all_stats</literal> role. Access may be granted to others
+  using <command>GRANT</command>.
  </para>
 
  <sect2>

doc/src/sgml/pgfreespacemap.sgml

@@ -16,8 +16,9 @@
  </para>
 
  <para>
-  By default public access is revoked from the functions, just in case
-  there are security issues lurking.
+  By default use is restricted to superusers and members of the
+  <literal>pg_stat_scan_tables</literal> role. Access may be granted to others
+  using <command>GRANT</command>.
  </para>
 
  <sect2>

doc/src/sgml/pgrowlocks.sgml

@@ -12,6 +12,13 @@
   locking information for a specified table.
  </para>
 
+ <para>
+  By default use is restricted to superusers, members of the
+  <literal>pg_stat_scan_tables</literal> role, and users with
+  <literal>SELECT</literal> permissions on the table.
+ </para>
+
+
  <sect2>
   <title>Overview</title>
 

doc/src/sgml/pgstatstatements.sgml

@@ -226,10 +226,11 @@
   </table>
 
   <para>
-   For security reasons, non-superusers are not allowed to see the SQL
-   text or <structfield>queryid</structfield> of queries executed by other users.
-   They can see the statistics, however, if the view has been installed in their
-   database.
+   For security reasons, only superusers and members of the
+   <literal>pg_read_all_stats<literal> role are allowed to see the SQL text and
+   <structfield>queryid</structfield> of queries executed by other users.
+   Other users can see the statistics, however, if the view has been installed
+   in their database.
   </para>
 
   <para>

doc/src/sgml/pgstattuple.sgml

@@ -16,7 +16,8 @@
   As these functions return detailed page-level information, only the superuser
   has EXECUTE privileges on them upon installation.  After the functions have
   been installed, users may issue <command>GRANT</command> commands to change
-  the privileges on the functions to allow non-superusers to execute them.  See
+  the privileges on the functions to allow non-superusers to execute them. Members
+  of the <literal>pg_stat_scan_tables</literal> role are granted access by default. See
   the description of the <xref linkend="sql-grant"> command for specifics.
  </para>
 

doc/src/sgml/pgvisibility.sgml

@@ -140,7 +140,10 @@
   </variablelist>
 
   <para>
-   By default, these functions are executable only by superusers.
+   By default, these functions are executable only by superusers and members of the
+   <literal>pg_stat_scan_tables</literal> role, with the exception of
+   <function>pg_truncate_visibility_map(relation regclass)</function> which can only
+   be executed by superusers.
   </para>
  </sect2>