enigma-bbs/core/door.js

/* jslint node: true */
'use strict';

const stringFormat = require('./string_format.js');
const { Errors } = require('./enig_error.js');
const Events = require('./events');

//  deps
const pty = require('node-pty');
const decode = require('iconv-lite').decode;
const createServer = require('net').createServer;
const paths = require('path');
const _ = require('lodash');

module.exports = class Door {
    constructor(client) {
        this.client = client;
        this.restored = false;
    }

    prepare(ioType, cb) {
        this.io = ioType;

        //  we currently only have to do any real setup for 'socket'
        if ('socket' !== ioType) {
            return cb(null);
        }

        this.sockServer = createServer(conn => {
            conn.once('end', () => {
                return this.restoreIo(conn);
            });

            conn.once('error', err => {
                this.client.log.info(
                    { error: err.message },
                    'Door socket server connection'
                );
                return this.restoreIo(conn);
            });

            this.sockServer.getConnections((err, count) => {
                //  We expect only one connection from our DOOR/emulator/etc.
                if (!err && count <= 1) {
                    this.client.term.output.pipe(conn);
                    conn.on('data', this.doorDataHandler.bind(this));
                }
            });
        });

        this.sockServer.listen(0, () => {
            return cb(null);
        });
    }

    run(exeInfo, cb) {
        this.encoding = (exeInfo.encoding || 'cp437').toLowerCase();

        if ('socket' === this.io && !this.sockServer) {
            return cb(Errors.UnexpectedState('Socket server is not running'));
        }

        const cwd = exeInfo.cwd || paths.dirname(exeInfo.cmd);

        const formatObj = {
            dropFile: exeInfo.dropFile,
            dropFilePath: exeInfo.dropFilePath,
            node: exeInfo.node.toString(),
            srvPort: this.sockServer ? this.sockServer.address().port.toString() : '-1',
            userId: this.client.user.userId.toString(),
            userName: this.client.user.getSanitizedName(),
            userNameRaw: this.client.user.username,
            cwd: cwd,
        };

        const args = exeInfo.args.map(arg => stringFormat(arg, formatObj));

        this.client.log.info(
            { cmd: exeInfo.cmd, args, io: this.io },
            'Executing external door process'
        );

        try {
            this.doorPty = pty.spawn(exeInfo.cmd, args, {
                cols: this.client.term.termWidth,
                rows: this.client.term.termHeight,
                cwd: cwd,
                env: exeInfo.env,
                encoding: null, //  we want to handle all encoding ourself
            });
        } catch (e) {
            return cb(e);
        }

        //
        //  PID is launched. Make sure it's killed off if the user disconnects.
        //
        Events.once(Events.getSystemEvents().ClientDisconnected, evt => {
            if (
                this.doorPty &&
                this.client.session.uniqueId === _.get(evt, 'client.session.uniqueId')
            ) {
                this.client.log.info(
                    { pid: this.doorPty.pid },
                    'User has disconnected; Killing door process.'
                );
                this.doorPty.kill();
            }
        });

        this.client.log.debug(
            { processId: this.doorPty.pid },
            'External door process spawned'
        );

        if ('stdio' === this.io) {
            this.client.log.debug('Using stdio for door I/O');

            this.client.term.output.pipe(this.doorPty);

            this.doorPty.onData(this.doorDataHandler.bind(this));

            this.doorPty.once('close', () => {
                return this.restoreIo(this.doorPty);
            });
        } else if ('socket' === this.io) {
            this.client.log.debug(
                {
                    srvPort: this.sockServer.address().port,
                    srvSocket: this.sockServerSocket,
                },
                'Using temporary socket server for door I/O'
            );
        }

        this.doorPty.once('exit', exitCode => {
            this.client.log.info({ exitCode: exitCode }, 'Door exited');

            if (this.sockServer) {
                this.sockServer.close();
            }

            //  we may not get a close
            if ('stdio' === this.io) {
                this.restoreIo(this.doorPty);
            }

            this.doorPty.removeAllListeners();
            delete this.doorPty;

            return cb(null);
        });
    }

    doorDataHandler(data) {
        this.client.term.write(decode(data, this.encoding));
    }

    restoreIo(piped) {
        if (!this.restored) {
            if (this.doorPty) {
                this.doorPty.kill();
            }

            const output = this.client.term.output;
            if (output) {
                output.unpipe(piped);
                output.resume();
            }
            this.restored = true;
        }
    }
};