MysqlInstaller.php

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<?php
use MediaWiki\Html\Html;
use MediaWiki\MediaWikiServices;
use Wikimedia\Rdbms\Database;
use Wikimedia\Rdbms\DatabaseFactory;
use Wikimedia\Rdbms\DBConnectionError;
use Wikimedia\Rdbms\DBQueryError;
 
class MysqlInstaller extends DatabaseInstaller {
 
    protected $globalNames = [
        'wgDBserver',
        'wgDBname',
        'wgDBuser',
        'wgDBpassword',
        'wgDBprefix',
        'wgDBTableOptions',
    ];
 
    protected $internalDefaults = [
        '_MysqlEngine' => 'InnoDB',
        '_MysqlCharset' => 'binary',
        '_InstallUser' => 'root',
    ];
 
    public $supportedEngines = [ 'InnoDB' ];
 
    public static $minimumVersion = '5.7.0';
    protected static $notMinimumVersionMessage = 'config-mysql-old';
 
    public $webUserPrivs = [
        'DELETE',
        'INSERT',
        'SELECT',
        'UPDATE',
        'CREATE TEMPORARY TABLES',
    ];
 
    public function getName() {
        return 'mysql';
    }
 
    public function isCompiled() {
        return self::checkExtension( 'mysqli' );
    }
 
    public function getConnectForm() {
        return $this->getTextBox(
            'wgDBserver',
            'config-db-host',
            [],
            $this->parent->getHelpBox( 'config-db-host-help' )
        ) .
            Html::openElement( 'fieldset' ) .
            Html::element( 'legend', [], wfMessage( 'config-db-wiki-settings' )->text() ) .
            $this->getTextBox( 'wgDBname', 'config-db-name', [ 'dir' => 'ltr' ],
                $this->parent->getHelpBox( 'config-db-name-help' ) ) .
            $this->getTextBox( 'wgDBprefix', 'config-db-prefix', [ 'dir' => 'ltr' ],
                $this->parent->getHelpBox( 'config-db-prefix-help' ) ) .
            Html::closeElement( 'fieldset' ) .
            $this->getInstallUserBox();
    }
 
    public function submitConnectForm() {
        // Get variables from the request.
        $newValues = $this->setVarsFromRequest( [ 'wgDBserver', 'wgDBname', 'wgDBprefix' ] );
 
        // Validate them.
        $status = Status::newGood();
        if ( !strlen( $newValues['wgDBserver'] ) ) {
            $status->fatal( 'config-missing-db-host' );
        }
        if ( !strlen( $newValues['wgDBname'] ) ) {
            $status->fatal( 'config-missing-db-name' );
        } elseif ( !preg_match( '/^[a-z0-9+_-]+$/i', $newValues['wgDBname'] ) ) {
            $status->fatal( 'config-invalid-db-name', $newValues['wgDBname'] );
        }
        if ( !preg_match( '/^[a-z0-9_-]*$/i', $newValues['wgDBprefix'] ) ) {
            $status->fatal( 'config-invalid-db-prefix', $newValues['wgDBprefix'] );
        }
        if ( !$status->isOK() ) {
            return $status;
        }
 
        // Submit user box
        $status = $this->submitInstallUserBox();
        if ( !$status->isOK() ) {
            return $status;
        }
 
        // Try to connect
        $status = $this->getConnection();
        if ( !$status->isOK() ) {
            return $status;
        }
        $conn = $status->value;
        '@phan-var Database $conn';
 
        // Check version
        return static::meetsMinimumRequirement( $conn->getServerVersion() );
    }
 
    public function openConnection() {
        $status = Status::newGood();
        try {
            $db = ( new DatabaseFactory() )->create( 'mysql', [
                'host' => $this->getVar( 'wgDBserver' ),
                'user' => $this->getVar( '_InstallUser' ),
                'password' => $this->getVar( '_InstallPassword' ),
                'dbname' => false,
                'flags' => 0,
                'tablePrefix' => $this->getVar( 'wgDBprefix' ) ] );
            $status->value = $db;
        } catch ( DBConnectionError $e ) {
            $status->fatal( 'config-connection-error', $e->getMessage() );
        }
 
        return $status;
    }
 
    public function preUpgrade() {
        global $wgDBuser, $wgDBpassword;
 
        $status = $this->getConnection();
        if ( !$status->isOK() ) {
            $this->parent->showStatusMessage( $status );
 
            return;
        }
        $conn = $status->value;
        $this->selectDatabase( $conn, $this->getVar( 'wgDBname' ) );
        # Determine existing default character set
        if ( $conn->tableExists( "revision", __METHOD__ ) ) {
            $revision = $this->escapeLikeInternal( $this->getVar( 'wgDBprefix' ) . 'revision', '\\' );
            $res = $conn->query( "SHOW TABLE STATUS LIKE '$revision'", __METHOD__ );
            $row = $res->fetchObject();
            if ( !$row ) {
                $this->parent->showMessage( 'config-show-table-status' );
                $existingSchema = false;
                $existingEngine = false;
            } else {
                if ( preg_match( '/^latin1/', $row->Collation ) ) {
                    $existingSchema = 'latin1';
                } elseif ( preg_match( '/^utf8/', $row->Collation ) ) {
                    $existingSchema = 'utf8';
                } elseif ( preg_match( '/^binary/', $row->Collation ) ) {
                    $existingSchema = 'binary';
                } else {
                    $existingSchema = false;
                    $this->parent->showMessage( 'config-unknown-collation' );
                }
                $existingEngine = $row->Engine ?? $row->Type;
            }
        } else {
            $existingSchema = false;
            $existingEngine = false;
        }
 
        if ( $existingSchema && $existingSchema != $this->getVar( '_MysqlCharset' ) ) {
            $this->setVar( '_MysqlCharset', $existingSchema );
        }
        if ( $existingEngine && $existingEngine != $this->getVar( '_MysqlEngine' ) ) {
            $this->setVar( '_MysqlEngine', $existingEngine );
        }
 
        # Normal user and password are selected after this step, so for now
        # just copy these two
        $wgDBuser = $this->getVar( '_InstallUser' );
        $wgDBpassword = $this->getVar( '_InstallPassword' );
    }
 
    protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
        return str_replace( [ $escapeChar, '%', '_' ],
            [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
            $s );
    }
 
    public function getEngines() {
        $status = $this->getConnection();
 
        $conn = $status->value;
 
        $engines = [];
        $res = $conn->query( 'SHOW ENGINES', __METHOD__ );
        foreach ( $res as $row ) {
            if ( $row->Support == 'YES' || $row->Support == 'DEFAULT' ) {
                $engines[] = $row->Engine;
            }
        }
        $engines = array_intersect( $this->supportedEngines, $engines );
 
        return $engines;
    }
 
    public function getCharsets() {
        return [ 'binary', 'utf8' ];
    }
 
    public function canCreateAccounts() {
        $status = $this->getConnection();
        if ( !$status->isOK() ) {
            return false;
        }
        $conn = $status->value;
 
        // Get current account name
        $currentName = $conn->selectField( '', 'CURRENT_USER()', '', __METHOD__ );
        $parts = explode( '@', $currentName );
        if ( count( $parts ) != 2 ) {
            return false;
        }
        $quotedUser = $conn->addQuotes( $parts[0] ) .
            '@' . $conn->addQuotes( $parts[1] );
 
        // The user needs to have INSERT on mysql.* to be able to CREATE USER
        // The grantee will be double-quoted in this query, as required
        $res = $conn->select( 'INFORMATION_SCHEMA.USER_PRIVILEGES', '*',
            [ 'GRANTEE' => $quotedUser ], __METHOD__ );
        $insertMysql = false;
        $grantOptions = array_fill_keys( $this->webUserPrivs, true );
        foreach ( $res as $row ) {
            if ( $row->PRIVILEGE_TYPE == 'INSERT' ) {
                $insertMysql = true;
            }
            if ( $row->IS_GRANTABLE ) {
                unset( $grantOptions[$row->PRIVILEGE_TYPE] );
            }
        }
 
        // Check for DB-specific privs for mysql.*
        if ( !$insertMysql ) {
            $row = $conn->selectRow( 'INFORMATION_SCHEMA.SCHEMA_PRIVILEGES', '*',
                [
                    'GRANTEE' => $quotedUser,
                    'TABLE_SCHEMA' => 'mysql',
                    'PRIVILEGE_TYPE' => 'INSERT',
                ], __METHOD__ );
            if ( $row ) {
                $insertMysql = true;
            }
        }
 
        if ( !$insertMysql ) {
            return false;
        }
 
        // Check for DB-level grant options
        $res = $conn->select( 'INFORMATION_SCHEMA.SCHEMA_PRIVILEGES', '*',
            [
                'GRANTEE' => $quotedUser,
                'IS_GRANTABLE' => 1,
            ], __METHOD__ );
        foreach ( $res as $row ) {
            $regex = $this->likeToRegex( $row->TABLE_SCHEMA );
            if ( preg_match( $regex, $this->getVar( 'wgDBname' ) ) ) {
                unset( $grantOptions[$row->PRIVILEGE_TYPE] );
            }
        }
        if ( count( $grantOptions ) ) {
            // Can't grant everything
            return false;
        }
 
        return true;
    }
 
    protected function likeToRegex( $wildcard ) {
        $r = preg_quote( $wildcard, '/' );
        $r = strtr( $r, [
            '%' => '.*',
            '_' => '.'
        ] );
        return "/$r/s";
    }
 
    public function getSettingsForm() {
        if ( $this->canCreateAccounts() ) {
            $noCreateMsg = false;
        } else {
            $noCreateMsg = 'config-db-web-no-create-privs';
        }
        $s = $this->getWebUserBox( $noCreateMsg );
 
        // Do engine selector
        $engines = $this->getEngines();
        // If the current default engine is not supported, use an engine that is
        if ( !in_array( $this->getVar( '_MysqlEngine' ), $engines ) ) {
            $this->setVar( '_MysqlEngine', reset( $engines ) );
        }
 
        // If the current default charset is not supported, use a charset that is
        $charsets = $this->getCharsets();
        if ( !in_array( $this->getVar( '_MysqlCharset' ), $charsets ) ) {
            $this->setVar( '_MysqlCharset', reset( $charsets ) );
        }
 
        return $s;
    }
 
    public function submitSettingsForm() {
        $this->setVarsFromRequest( [ '_MysqlEngine', '_MysqlCharset' ] );
        $status = $this->submitWebUserBox();
        if ( !$status->isOK() ) {
            return $status;
        }
 
        // Validate the create checkbox
        $canCreate = $this->canCreateAccounts();
        if ( !$canCreate ) {
            $this->setVar( '_CreateDBAccount', false );
            $create = false;
        } else {
            $create = $this->getVar( '_CreateDBAccount' );
        }
 
        if ( !$create ) {
            // Test the web account
            try {
                MediaWikiServices::getInstance()->getDatabaseFactory()->create( 'mysql', [
                    'host' => $this->getVar( 'wgDBserver' ),
                    'user' => $this->getVar( 'wgDBuser' ),
                    'password' => $this->getVar( 'wgDBpassword' ),
                    'dbname' => false,
                    'flags' => 0,
                    'tablePrefix' => $this->getVar( 'wgDBprefix' )
                ] );
            } catch ( DBConnectionError $e ) {
                return Status::newFatal( 'config-connection-error', $e->getMessage() );
            }
        }
 
        // Validate engines and charsets
        // This is done pre-submit already so it's just for security
        $engines = $this->getEngines();
        if ( !in_array( $this->getVar( '_MysqlEngine' ), $engines ) ) {
            $this->setVar( '_MysqlEngine', reset( $engines ) );
        }
        $charsets = $this->getCharsets();
        if ( !in_array( $this->getVar( '_MysqlCharset' ), $charsets ) ) {
            $this->setVar( '_MysqlCharset', reset( $charsets ) );
        }
 
        return Status::newGood();
    }
 
    public function preInstall() {
        # Add our user callback to installSteps, right before the tables are created.
        $callback = [
            'name' => 'user',
            'callback' => [ $this, 'setupUser' ],
        ];
        $this->parent->addInstallStep( $callback, 'tables' );
    }
 
    public function setupDatabase() {
        $status = $this->getConnection();
        if ( !$status->isOK() ) {
            return $status;
        }
        $conn = $status->value;
        $dbName = $this->getVar( 'wgDBname' );
        if ( !$this->databaseExists( $dbName ) ) {
            $conn->query(
                "CREATE DATABASE " . $conn->addIdentifierQuotes( $dbName ) . "CHARACTER SET utf8",
                __METHOD__
            );
        }
        $this->selectDatabase( $conn, $dbName );
        $this->setupSchemaVars();
 
        return $status;
    }
 
    private function databaseExists( $dbName ) {
        $encDatabase = $this->db->addQuotes( $dbName );
 
        return $this->db->query(
            "SELECT 1 FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = $encDatabase",
            __METHOD__
        )->numRows() > 0;
    }
 
    public function setupUser() {
        $dbUser = $this->getVar( 'wgDBuser' );
        if ( $dbUser == $this->getVar( '_InstallUser' ) ) {
            return Status::newGood();
        }
        $status = $this->getConnection();
        if ( !$status->isOK() ) {
            return $status;
        }
 
        $this->setupSchemaVars();
        $dbName = $this->getVar( 'wgDBname' );
        $this->selectDatabase( $this->db, $dbName );
        $server = $this->getVar( 'wgDBserver' );
        $password = $this->getVar( 'wgDBpassword' );
        $grantableNames = [];
 
        if ( $this->getVar( '_CreateDBAccount' ) ) {
            // Before we blindly try to create a user that already has access,
            try { // first attempt to connect to the database
                ( new DatabaseFactory() )->create( 'mysql', [
                    'host' => $server,
                    'user' => $dbUser,
                    'password' => $password,
                    'dbname' => false,
                    'flags' => 0,
                    'tablePrefix' => $this->getVar( 'wgDBprefix' )
                ] );
                $grantableNames[] = $this->buildFullUserName( $dbUser, $server );
                $tryToCreate = false;
            } catch ( DBConnectionError $e ) {
                $tryToCreate = true;
            }
        } else {
            $grantableNames[] = $this->buildFullUserName( $dbUser, $server );
            $tryToCreate = false;
        }
 
        if ( $tryToCreate ) {
            $createHostList = [
                $server,
                'localhost',
                'localhost.localdomain',
                '%'
            ];
 
            $createHostList = array_unique( $createHostList );
            $escPass = $this->db->addQuotes( $password );
 
            foreach ( $createHostList as $host ) {
                $fullName = $this->buildFullUserName( $dbUser, $host );
                if ( !$this->userDefinitelyExists( $host, $dbUser ) ) {
                    try {
                        $this->db->begin( __METHOD__ );
                        $this->db->query( "CREATE USER $fullName IDENTIFIED BY $escPass", __METHOD__ );
                        $this->db->commit( __METHOD__ );
                        $grantableNames[] = $fullName;
                    } catch ( DBQueryError $dqe ) {
                        if ( $this->db->lastErrno() == 1396 /* ER_CANNOT_USER */ ) {
                            // User (probably) already exists
                            $this->db->rollback( __METHOD__ );
                            $status->warning( 'config-install-user-alreadyexists', $dbUser );
                            $grantableNames[] = $fullName;
                            break;
                        } else {
                            // If we couldn't create for some bizarre reason and the
                            // user probably doesn't exist, skip the grant
                            $this->db->rollback( __METHOD__ );
                            $status->warning( 'config-install-user-create-failed', $dbUser, $dqe->getMessage() );
                        }
                    }
                } else {
                    $status->warning( 'config-install-user-alreadyexists', $dbUser );
                    $grantableNames[] = $fullName;
                    break;
                }
            }
        }
 
        // Try to grant to all the users we know exist or we were able to create
        $dbAllTables = $this->db->addIdentifierQuotes( $dbName ) . '.*';
        foreach ( $grantableNames as $name ) {
            try {
                $this->db->begin( __METHOD__ );
                $this->db->query( "GRANT ALL PRIVILEGES ON $dbAllTables TO $name", __METHOD__ );
                $this->db->commit( __METHOD__ );
            } catch ( DBQueryError $dqe ) {
                $this->db->rollback( __METHOD__ );
                $status->fatal( 'config-install-user-grant-failed', $dbUser, $dqe->getMessage() );
            }
        }
 
        return $status;
    }
 
    private function buildFullUserName( $name, $host ) {
        return $this->db->addQuotes( $name ) . '@' . $this->db->addQuotes( $host );
    }
 
    private function userDefinitelyExists( $host, $user ) {
        try {
            $res = $this->db->selectRow( 'mysql.user', [ 'Host', 'User' ],
                [ 'Host' => $host, 'User' => $user ], __METHOD__ );
 
            return (bool)$res;
        } catch ( DBQueryError $dqe ) {
            return false;
        }
    }
 
    protected function getTableOptions() {
        $options = [];
        if ( $this->getVar( '_MysqlEngine' ) !== null ) {
            $options[] = "ENGINE=" . $this->getVar( '_MysqlEngine' );
        }
        if ( $this->getVar( '_MysqlCharset' ) !== null ) {
            $options[] = 'DEFAULT CHARSET=' . $this->getVar( '_MysqlCharset' );
        }
 
        return implode( ', ', $options );
    }
 
    public function getSchemaVars() {
        return [
            'wgDBTableOptions' => $this->getTableOptions(),
            'wgDBname' => $this->getVar( 'wgDBname' ),
            'wgDBuser' => $this->getVar( 'wgDBuser' ),
            'wgDBpassword' => $this->getVar( 'wgDBpassword' ),
        ];
    }
 
    public function getLocalSettings() {
        $prefix = LocalSettingsGenerator::escapePhpString( $this->getVar( 'wgDBprefix' ) );
        $tblOpts = LocalSettingsGenerator::escapePhpString( $this->getTableOptions() );
 
        return "# MySQL specific settings
\$wgDBprefix = \"{$prefix}\";
 
# MySQL table options to use during installation or update
\$wgDBTableOptions = \"{$tblOpts}\";";
    }
}