[PATCH] allow pg_current_logfile() execution under pg_monitor role

From bfe542c5d7b3c981e75ac6551abb34fbdf646eea Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Tue, 13 Feb 2024 15:12:36 -0600
Subject: [PATCH v2 1/1] Allow pg_monitor to execute pg_current_logfile().

We allow roles with privileges of pg_monitor to execute functions
like pg_ls_logdir(), so it seems natural that such roles would also
be able to execute this function.

Bumps catversion.

Co-authored-by: Pavlo Golub
Discussion: https://postgr.es/m/CAK7ymcLmEYWyQkiCZ64WC-HCzXAB0omM%3DYpj9B3rXe8vUAFMqw%40mail.gmail.com
---
 doc/src/sgml/func.sgml                       |  5 +++++
 src/backend/catalog/system_functions.sql     |  4 ++++
 src/include/catalog/catversion.h             |  2 +-
 src/test/regress/expected/misc_functions.out | 20 ++++++++++++++++++++
 src/test/regress/sql/misc_functions.sql      | 11 +++++++++++
 5 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 11d537b341..c4e5b4967e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -23735,6 +23735,11 @@ SELECT * FROM pg_ls_dir('.') WITH ORDINALITY AS t(ls,n);
         <xref linkend="guc-log-destination"/>.
         The result reflects the contents of
         the <filename>current_logfiles</filename> file.
+       </para>
+       <para>
+        This function is restricted to superusers and roles with privileges of
+        the <literal>pg_monitor</literal> role by default, but other users can
+        be granted EXECUTE to run the function.
        </para></entry>
       </row>
 
diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 346cfb98a0..fe2bb50f46 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -777,6 +777,10 @@ GRANT EXECUTE ON FUNCTION pg_ls_logicalmapdir() TO pg_monitor;
 
 GRANT EXECUTE ON FUNCTION pg_ls_replslotdir(text) TO pg_monitor;
 
+GRANT EXECUTE ON FUNCTION pg_current_logfile() TO pg_monitor;
+
+GRANT EXECUTE ON FUNCTION pg_current_logfile(text) TO pg_monitor;
+
 GRANT pg_read_all_settings TO pg_monitor;
 
 GRANT pg_read_all_stats TO pg_monitor;
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 9fc8ac9290..80a4c19565 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202401301
+#define CATALOG_VERSION_NO	202402131
 
 #endif
diff --git a/src/test/regress/expected/misc_functions.out b/src/test/regress/expected/misc_functions.out
index 7c15477104..d5f61dfad9 100644
--- a/src/test/regress/expected/misc_functions.out
+++ b/src/test/regress/expected/misc_functions.out
@@ -683,3 +683,23 @@ SELECT gist_stratnum_identity(18::smallint);
                      18
 (1 row)
 
+-- pg_current_logfile
+CREATE ROLE regress_current_logfile;
+-- not available by default
+SELECT has_function_privilege('regress_current_logfile',
+  'pg_current_logfile()', 'EXECUTE');
+ has_function_privilege 
+------------------------
+ f
+(1 row)
+
+GRANT pg_monitor TO regress_current_logfile;
+-- role has privileges of pg_monitor and can execute the function
+SELECT has_function_privilege('regress_current_logfile',
+  'pg_current_logfile()', 'EXECUTE');
+ has_function_privilege 
+------------------------
+ t
+(1 row)
+
+DROP ROLE regress_current_logfile;
diff --git a/src/test/regress/sql/misc_functions.sql b/src/test/regress/sql/misc_functions.sql
index 851dad90f4..928b04db7f 100644
--- a/src/test/regress/sql/misc_functions.sql
+++ b/src/test/regress/sql/misc_functions.sql
@@ -254,3 +254,14 @@ FROM pg_walfile_name_offset('0/0'::pg_lsn + :segment_size - 1),
 -- test stratnum support functions
 SELECT gist_stratnum_identity(3::smallint);
 SELECT gist_stratnum_identity(18::smallint);
+
+-- pg_current_logfile
+CREATE ROLE regress_current_logfile;
+-- not available by default
+SELECT has_function_privilege('regress_current_logfile',
+  'pg_current_logfile()', 'EXECUTE');
+GRANT pg_monitor TO regress_current_logfile;
+-- role has privileges of pg_monitor and can execute the function
+SELECT has_function_privilege('regress_current_logfile',
+  'pg_current_logfile()', 'EXECUTE');
+DROP ROLE regress_current_logfile;
-- 
2.25.1