MDEV-24815 Add 'allow-suspicious-udfs' and 'skip-grant-tables' to system variables

Make two existing command line options "allow-suspicious-udfs" and
"skip-grant-tables" visible as global system variables.

Both options have security implications, but users were not able to check
their states in the server prior to this change. This was a security
issue, as the user may not be aware if the options are enabled. By adding
them into system variables, it increases users’ visibility into their
security configurations.

Create new MTR tests to verify that the system variables align with the
command line options. Minor adjustments to the existing MTR due to the new
members in system variables.

Before:
    mysql> SHOW VARIABLES WHERE
    Variable_Name LIKE 'allow_suspicious_udfs' OR
    Variable_Name LIKE 'skip_grant_tables';
    Empty set (0.000 sec)

After:
    mysql> SHOW VARIABLES WHERE
    Variable_Name LIKE 'allow_suspicious_udfs' OR
    Variable_Name LIKE 'skip_grant_tables';
    +-----------------------+-------+
    | Variable_name         | Value |
    +-----------------------+-------+
    | allow_suspicious_udfs | OFF   |
    | skip_grant_tables     | OFF   |
    +-----------------------+-------+

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.

mysql-test/main/mysql_upgrade-6984.result

@@ -168,3 +168,4 @@ connect con1,localhost,root,foo,,,;
 update mysql.global_priv set priv=json_compact(json_remove(priv, '$.plugin', '$.authentication_string'))  where user='root';
 flush privileges;
 set global event_scheduler=OFF;
+# restart

mysql-test/main/mysql_upgrade-6984.test

@@ -26,3 +26,7 @@ set global event_scheduler=OFF;
 
 let MYSQLD_DATADIR= `select @@datadir`;
 --remove_file $MYSQLD_DATADIR/mysql_upgrade_info
+
+# --skip-grant-tables state may changed during the test. Need to restart the server
+# to restore the --skip-grant-tables state. Otherwise MTR's internal check will fail
+--source include/restart_mysqld.inc

mysql-test/main/mysqld--help.result

@@ -8,10 +8,11 @@ The following specify which files/extra groups are read (specified before remain
 --defaults-group-suffix=# Additionally read default groups with # appended as a suffix.
 
  --allow-suspicious-udfs 
- Allows use of UDFs consisting of only one symbol xxx()
- without corresponding xxx_init() or xxx_deinit(). That
- also means that one can load any function from any
- library, for example exit() from libc.so
+ Allows use of user-defined functions (UDFs) consisting of
+ only one symbol xxx() without corresponding xxx_init() or
+ xxx_deinit(). That also means that one can load any
+ function from any library, for example exit() from
+ libc.so
  --alter-algorithm[=name] 
  Specify the alter table algorithm. One of: DEFAULT, COPY,
  INPLACE, NOCOPY, INSTANT

mysql-test/main/skip_grants.result

@@ -137,3 +137,17 @@ drop user baz@baz;
 #
 # End of 10.3 tests
 #
+#
+# MDEV-24815 Show "--skip-grant-tables" state in SYSTEM VARIABLES
+#
+SELECT @@skip_grant_tables AS EXPECT_1;
+EXPECT_1
+1
+# restart: --skip-skip-grant-tables
+SELECT @@skip_grant_tables AS EXPECT_0;
+EXPECT_0
+0
+# restart: --skip-grant-tables
+#
+# End of 10.10 tests
+#

mysql-test/main/skip_grants.test

@@ -160,7 +160,7 @@ alter user baz@baz identified with mysql_native_password as password("baz");
 show create user baz@baz;
 drop user bar@foo;
 drop user baz@baz;
-# need to restart the server to restore the --skip-grant state
+# Need to restart the server to restore the "--skip-grant-tables" state
 --source include/restart_mysqld.inc
 
 --enable_ps_protocol
@@ -168,3 +168,22 @@ drop user baz@baz;
 --echo #
 --echo # End of 10.3 tests
 --echo #
+
+--echo #
+--echo # MDEV-24815 Show "--skip-grant-tables" state in SYSTEM VARIABLES
+--echo #
+
+SELECT @@skip_grant_tables AS EXPECT_1;
+
+# Also check when the server starts without "--skip-grant-table" option
+--let $restart_parameters = "--skip-skip-grant-tables"
+--source include/restart_mysqld.inc
+SELECT @@skip_grant_tables AS EXPECT_0;
+
+# Need to restart the server to restore the "--skip-grant-tables" state
+--let $restart_parameters = "--skip-grant-tables"
+--source include/restart_mysqld.inc
+
+--echo #
+--echo # End of 10.10 tests
+--echo #

mysql-test/suite/sys_vars/r/allow_suspicious_udfs.result

+#
+# MDEV-24815 Show "--allow-suspicious-udfs" state in SYSTEM VARIABLES
+#
+SELECT @@allow_suspicious_udfs AS EXPECT_0;
+EXPECT_0
+0
+# restart: --allow-suspicious-udfs
+SELECT @@allow_suspicious_udfs AS EXPECT_1;
+EXPECT_1
+1
+# restart: --skip-allow-suspicious-udfs

mysql-test/suite/sys_vars/r/sysvars_server_embedded.result

@@ -12,6 +12,16 @@ variable_name not in (
 'log_tc_size','have_sanitizer'
         )
 order by variable_name;
+VARIABLE_NAME	ALLOW_SUSPICIOUS_UDFS
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	BOOLEAN
+VARIABLE_COMMENT	Allows use of user-defined functions (UDFs) consisting of only one symbol xxx() without corresponding xxx_init() or xxx_deinit(). That also means that one can load any function from any library, for example exit() from libc.so
+NUMERIC_MIN_VALUE	NULL
+NUMERIC_MAX_VALUE	NULL
+NUMERIC_BLOCK_SIZE	NULL
+ENUM_VALUE_LIST	OFF,ON
+READ_ONLY	YES
+COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	ALTER_ALGORITHM
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	ENUM
@@ -3082,6 +3092,16 @@ NUMERIC_BLOCK_SIZE	NULL
 ENUM_VALUE_LIST	OFF,ON
 READ_ONLY	YES
 COMMAND_LINE_ARGUMENT	NULL
+VARIABLE_NAME	SKIP_GRANT_TABLES
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	BOOLEAN
+VARIABLE_COMMENT	Start without grant tables. This gives all users FULL ACCESS to all tables.
+NUMERIC_MIN_VALUE	NULL
+NUMERIC_MAX_VALUE	NULL
+NUMERIC_BLOCK_SIZE	NULL
+ENUM_VALUE_LIST	OFF,ON
+READ_ONLY	YES
+COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	SKIP_NAME_RESOLVE
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	BOOLEAN

mysql-test/suite/sys_vars/r/sysvars_server_notembedded.result

@@ -12,6 +12,16 @@ variable_name not in (
 'log_tc_size','have_sanitizer'
         )
 order by variable_name;
+VARIABLE_NAME	ALLOW_SUSPICIOUS_UDFS
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	BOOLEAN
+VARIABLE_COMMENT	Allows use of user-defined functions (UDFs) consisting of only one symbol xxx() without corresponding xxx_init() or xxx_deinit(). That also means that one can load any function from any library, for example exit() from libc.so
+NUMERIC_MIN_VALUE	NULL
+NUMERIC_MAX_VALUE	NULL
+NUMERIC_BLOCK_SIZE	NULL
+ENUM_VALUE_LIST	OFF,ON
+READ_ONLY	YES
+COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	ALTER_ALGORITHM
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	ENUM
@@ -3582,6 +3592,16 @@ NUMERIC_BLOCK_SIZE	NULL
 ENUM_VALUE_LIST	OFF,ON
 READ_ONLY	YES
 COMMAND_LINE_ARGUMENT	NULL
+VARIABLE_NAME	SKIP_GRANT_TABLES
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	BOOLEAN
+VARIABLE_COMMENT	Start without grant tables. This gives all users FULL ACCESS to all tables.
+NUMERIC_MIN_VALUE	NULL
+NUMERIC_MAX_VALUE	NULL
+NUMERIC_BLOCK_SIZE	NULL
+ENUM_VALUE_LIST	OFF,ON
+READ_ONLY	YES
+COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	SKIP_NAME_RESOLVE
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	BOOLEAN

mysql-test/suite/sys_vars/t/allow_suspicious_udfs.test

+--echo #
+--echo # MDEV-24815 Show "--allow-suspicious-udfs" state in SYSTEM VARIABLES
+--echo #
+
+SELECT @@allow_suspicious_udfs AS EXPECT_0;
+
+# Restart the server the server with "--allow-suspicious-udfs" option
+--let $restart_parameters = "--allow-suspicious-udfs"
+--source include/restart_mysqld.inc
+SELECT @@allow_suspicious_udfs AS EXPECT_1;
+
+# Disable "--allow-suspicious-udfs" to restore the original state
+--let $restart_parameters = "--skip-allow-suspicious-udfs"
+--source include/restart_mysqld.inc

sql/mysqld.cc

@@ -6342,13 +6342,6 @@ struct my_option my_long_options[]=
   {"help", '?', "Display this help and exit.", 
    &opt_help, &opt_help, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0,
    0, 0},
-  {"allow-suspicious-udfs", 0,
-   "Allows use of UDFs consisting of only one symbol xxx() "
-   "without corresponding xxx_init() or xxx_deinit(). That also means "
-   "that one can load any function from any library, for example exit() "
-   "from libc.so",
-   &opt_allow_suspicious_udfs, &opt_allow_suspicious_udfs,
-   0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"ansi", 'a', "Use ANSI SQL syntax instead of MySQL syntax. This mode "
    "will also set transaction isolation level 'serializable'.", 0, 0, 0,
    GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
@@ -6673,12 +6666,6 @@ struct my_option my_long_options[]=
    GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"silent-startup", OPT_SILENT, "Don't print [Note] to the error log during startup.",
    &opt_silent_startup, &opt_silent_startup, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
-#ifndef DISABLE_GRANT_OPTIONS
-  {"skip-grant-tables", 0,
-   "Start without grant tables. This gives all users FULL ACCESS to all tables.",
-   &opt_noacl, &opt_noacl, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0,
-   0},
-#endif
   {"skip-host-cache", OPT_SKIP_HOST_CACHE, "Don't cache host names.", 0, 0, 0,
    GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"skip-slave-start", 0,

sql/sys_vars.cc

@@ -2677,6 +2677,20 @@ static Sys_var_mybool Sys_old_mode(
        SESSION_VAR(old_mode), CMD_LINE(OPT_ARG), DEFAULT(FALSE), 0, NOT_IN_BINLOG, ON_CHECK(0),
        ON_UPDATE(set_old_mode), DEPRECATED("'@@old_mode'"));
 
+static Sys_var_mybool Sys_opt_allow_suspicious_udfs(
+       "allow_suspicious_udfs",
+       "Allows use of user-defined functions (UDFs) consisting of only one symbol xxx() without corresponding xxx_init() or xxx_deinit(). That also means that one can load any function from any library, for example exit() from libc.so",
+       READ_ONLY GLOBAL_VAR(opt_allow_suspicious_udfs),
+       CMD_LINE(OPT_ARG), DEFAULT(FALSE));
+
+#ifndef DISABLE_GRANT_OPTIONS
+static Sys_var_mybool Sys_skip_grant_tables(
+       "skip_grant_tables",
+       "Start without grant tables. This gives all users FULL ACCESS to all tables.",
+       READ_ONLY GLOBAL_VAR(opt_noacl),
+       CMD_LINE(OPT_ARG), DEFAULT(FALSE));
+#endif
+
 static const char *alter_algorithm_modes[]= {"DEFAULT", "COPY", "INPLACE",
 "NOCOPY", "INSTANT", NULL};