<?php
/**
* Suppress "error - 0 - No summary was found for this file" on phpdoc generation
*
* @package WPDataAccess\Data_Dictionary
*/
namespace WPDataAccess\Data_Dictionary {
use WPDataAccess\List_Table\WPDA_List_Table;
use WPDataAccess\WPDA;
/**
* Class WPDA_Dictionary_Access
*
* Check if access to a given table is granted. The existence of the table name (and schema name for back-end) is
* not checked in this class. The class presumes that the table name (and schema name for back-end) is valid.
*
* The argument $done, which is used throughout the class, indicates whether the access check confirms the
* existence of the table or whether no access is granted anyway and therefor no further checks are needed. In
* some situations this saves us a query.
*
* For example:
*
* If table $wpdb->options is provided as an argument and access to WordPress tables is allowed we are done. If
* only selected tables are allowed and the table provided as an argument is either in or not in the list we done
* as well. When calling WPDA_Dictionary_Access functions check the return value as well as $done.
*
* @author Peter Schulz
* @since 1.0.0
*/
class WPDA_Dictionary_Access {
/**
* Check back-end table access
*
* Checks if access to a given schema and table is granted for back-end usage.
*
* The schema name must be provided as an argument. This argument is mainly added to support a clean access
* check for the data explorer view which uses the view TABLES from MySQL schema INFORMATION_SCHEMA (see
* {@see WPDA_List_Table::LIST_BASE_TABLE}). This is the only table/view outside the WordPress schema to
* which access is granted.
*
* @param string $schema_name Schema name in which the table or view is located.
* @param string $table_name Table or view name.
* @param boolean $done TRUE = no further checks needed, FALSE = still need to check table name.
*
* @return bool TRUE = access granted, FALSE = access denied.
* @since 1.0.0
*
* @see WPDA_List_Table::LIST_BASE_TABLE
*/
public static function check_table_access_backend( $schema_name, $table_name, &$done ) {
if ( WPDA_List_Table::LIST_BASE_TABLE === $schema_name . '.' . $table_name ) {
// Always grant access to table list.
$done = true; // No further checks needed.
return true;
}
global $wpdb;
if ( $schema_name === $wpdb->dbname && WPDA::is_wpda_table( $table_name ) ) {
// Always grant access to WPDA table's in the back-end.
$done = true; // No further checks needed.
return true;
}
if ( $schema_name === $wpdb->dbname ) {
$table_access = WPDA::get_option( WPDA::OPTION_BE_TABLE_ACCESS );
$table_access_selected = WPDA::get_option( WPDA::OPTION_BE_TABLE_ACCESS_SELECTED );
} else {
$table_access = get_option( WPDA::BACKEND_OPTIONNAME_DATABASE_ACCESS . $schema_name );
if ( false === $table_access ) {
$table_access = 'show';
}
$table_access_selected = get_option( WPDA::BACKEND_OPTIONNAME_DATABASE_SELECTED . $schema_name );
if ( false === $table_access_selected ) {
$table_access_selected = '';
}
}
return self::check_table_access( $schema_name, $table_name, $table_access, $table_access_selected, $done );
}
/**
* Check tables access
*
* Checks if access to a given table is granted for back-end or front-end usage. Whether the check is performed
* for the back-end or front-end depends on the arguments $table_access and $table_access_selected.
*
* The schema name is not reflected in this check. It presumed that the schema name if the schema in which
* WordPress is installed.
*
* This function is code which is shared between {@see WPDA_Dictionary_Access::check_table_access_backend()}
* and {@see WPDA_Dictionary_Access::check_table_access_frontend()}.
*
* @param string $schema_name Schema name in which the table or view is located.
* @param string $table_name Table or view name.
* @param string $table_access Option value for table access as stored in wp_options.
* @param string $table_access_selected Option value for tables selected access as stored in wp_options.
* @param boolean $done TRUE = no futher checks needed, FALSE = still need to check table name.
*
* @return bool TRUE = access granted, FALSE = access denied.
* @see WPDA_Dictionary_Access::check_table_access_frontend()
*
* @since 1.0.0
*
* @see WPDA_Dictionary_Access::check_table_access_backend()
*/
protected static function check_table_access( $schema_name, $table_name, $table_access, $table_access_selected, &$done ) {
if ( 'hide' === $table_access ) {
global $wpdb;
if ( $wpdb->dbname !== $schema_name ) {
// Non WordPress database: access granted.
$done = false; // Still need to check if table exists.
return true;
}
// No access to WordPress tables: check if the requested table is a WordPress table.
$wp_tables = $wpdb->tables( 'all', true );
if ( isset( $wp_tables[ substr( $table_name, strlen( $wpdb->prefix ) ) ] ) &&
$wp_tables[ substr( $table_name, strlen( $wpdb->prefix ) ) ] === $table_name
) {
// WordPress table: deny access.
$done = true; // No further checks needed.
return false;
} else {
// Non WordPress table: access granted.
$done = false; // Still need to check if table exists.
return true;
}
} elseif ( 'select' === $table_access ) {
// Only access to selected tables and views (front-end settings).
if ( '' !== $table_access_selected ) {
foreach ( $table_access_selected as $key => $value ) {
if ( $table_name === $value ) {
// Access to this table or view is granted.
$done = true; // No further checks needed.
return true;
}
}
}
// No access.
$done = true; // No further checks needed.
return false;
} else {
// Access granted to all tables and views.
$done = false; // Still need to check if table exists.
return true;
}
}
/**
* Check front-end table access
*
* Checks if access to a given table is granted for front-end usage.
*
* The schema name is not reflected in this check. It presumed that the schema name if the schema in which
* WordPress is installed.
*
* @param string $schema_name Schema name in which the table or view is located.
* @param string $table_name Table or view name.
* @param boolean $done TRUE = no futher checks needed, FALSE = still need to check table name.
*
* @return bool TRUE = access granted, FALSE = access denied.
* @since 1.0.0
*/
public static function check_table_access_frontend( $schema_name, $table_name, &$done ) {
global $wpdb;
if ( $wpdb->dbname === $schema_name ) {
$table_access = WPDA::get_option( WPDA::OPTION_FE_TABLE_ACCESS );
$table_access_selected = WPDA::get_option( WPDA::OPTION_FE_TABLE_ACCESS_SELECTED );
} else {
$table_access = get_option( WPDA::FRONTEND_OPTIONNAME_DATABASE_ACCESS . $schema_name );
if ( false === $table_access ) {
$table_access = 'select';
}
$table_access_selected = get_option( WPDA::FRONTEND_OPTIONNAME_DATABASE_SELECTED . $schema_name );
if ( false === $table_access_selected ) {
$table_access_selected = '';
}
}
return self::check_table_access( $schema_name, $table_name, $table_access, $table_access_selected, $done );
}
/**
* Check if user has CREATE (database) privilege
*
* @return bool
* @since 2.7.2
*/
public static function can_create_db() {
global $wpdb;
$wpdb->get_results(
"select * from information_schema.user_privileges
where privilege_type = 'CREATE'
and replace(grantee, '\'', '') = current_user()"
);
return $wpdb->num_rows > 0;
}
/**
* Check if user has DROP (database) privilege
*
* @return bool
* @since 2.7.2
*/
public static function can_drop_db() {
global $wpdb;
$wpdb->get_results(
"select * from information_schema.user_privileges
where privilege_type = 'DROP'
and replace(grantee, '\'', '') = current_user()"
);
return $wpdb->num_rows > 0;
}
}
}