blinksocks/lib/presets/_mux.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _defs = require("./defs");

var _utils = require("../utils");

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

const CMD_NEW_CONN = 0x00;
const CMD_DATA_FRAME = 0x01;
const CMD_CLOSE_CONN = 0x02;

class MuxPreset extends _defs.IPresetAddressing {
  constructor(...args) {
    super(...args);

    _defineProperty(this, "_adBuf", null);
  }

  onInit() {
    this._adBuf = new _utils.AdvancedBuffer({
      getPacketLength: this.onReceiving.bind(this)
    });

    this._adBuf.on('data', this.onChunkReceived.bind(this));
  }

  onDestroy() {
    this._adBuf.clear();

    this._adBuf = null;
  }

  onReceiving(buffer, {
    fail
  }) {
    if (buffer.length < 5) {
      return;
    }

    const cmd = buffer[0];

    switch (cmd) {
      case CMD_NEW_CONN:
        if (buffer.length < 8 + buffer[5]) {
          return;
        }

        return 8 + buffer[5];

      case CMD_DATA_FRAME:
        if (buffer.length < 7) {
          return;
        }

        return 7 + buffer.readUInt16BE(5);

      case CMD_CLOSE_CONN:
        return 5;

      default:
        fail(`unknown cmd=${cmd} dump=${(0, _utils.dumpHex)(buffer)}`);
        return -1;
    }
  }

  onChunkReceived(chunk, {
    fail
  }) {
    const cmd = chunk[0];
    const cid = chunk.slice(1, 5).toString('hex');

    switch (cmd) {
      case CMD_NEW_CONN:
        {
          const hostBuf = chunk.slice(6, -2);
          const host = hostBuf.toString();
          const port = chunk.readUInt16BE(6 + chunk[5]);

          if (!(0, _utils.isValidHostname)(host) || !(0, _utils.isValidPort)(port)) {
            return fail(`invalid host or port, host=${(0, _utils.dumpHex)(hostBuf)} port=${port}`);
          }

          return this.muxNewConn({
            cid,
            host,
            port
          });
        }

      case CMD_DATA_FRAME:
        {
          const dataLen = chunk.readUInt16BE(5);
          return this.muxDataFrame({
            cid,
            data: chunk.slice(-dataLen)
          });
        }

      case CMD_CLOSE_CONN:
        return this.muxCloseConn({
          cid
        });
    }
  }

  createDataFrames(cid, data) {
    const chunks = (0, _utils.getRandomChunks)(data, 0x0800, 0x3fff).map(chunk => Buffer.concat([(0, _utils.numberToBuffer)(CMD_DATA_FRAME, 1), cid, (0, _utils.numberToBuffer)(chunk.length), chunk]));
    return Buffer.concat(chunks);
  }

  createNewConn(host, port, cid) {
    const _host = Buffer.from(host);

    const _port = (0, _utils.numberToBuffer)(port);

    return Buffer.concat([(0, _utils.numberToBuffer)(CMD_NEW_CONN, 1), cid, (0, _utils.numberToBuffer)(_host.length, 1), _host, _port]);
  }

  createCloseConn(cid) {
    return Buffer.concat([(0, _utils.numberToBuffer)(CMD_CLOSE_CONN, 1), cid]);
  }

  clientOut({
    buffer,
    fail
  }, {
    host,
    port,
    cid,
    isClosing
  }) {
    if (cid !== undefined) {
      const _cid = Buffer.from(cid, 'hex');

      if (isClosing) {
        return this.createCloseConn(_cid);
      }

      const dataFrames = this.createDataFrames(_cid, buffer);

      if (host && port) {
        return Buffer.concat([this.createNewConn(host, port, _cid), dataFrames]);
      }

      return dataFrames;
    } else {
      fail(`cid is not provided, drop buffer=${(0, _utils.dumpHex)(buffer)}`);
    }
  }

  serverOut({
    buffer,
    fail
  }, {
    cid,
    isClosing
  }) {
    if (cid !== undefined) {
      const _cid = Buffer.from(cid, 'hex');

      if (isClosing) {
        return this.createCloseConn(_cid);
      }

      return this.createDataFrames(_cid, buffer);
    } else {
      fail(`cid is not provided, drop buffer=${(0, _utils.dumpHex)(buffer)}`);
    }
  }

  beforeIn({
    buffer,
    fail
  }) {
    this._adBuf.put(buffer, {
      fail
    });
  }

}

exports.default = MuxPreset;

_defineProperty(MuxPreset, "isPrivate", true);