sclient.js/bin/sclient.js

#!/usr/bin/env node
'use strict';

var pkg = require('../package.json');
var remote;
var local;
var isPiped = !process.stdin.isTTY;
var localAddress;
var localPort;

function usage() {
  console.info("");
  console.info("sclient.js v" + pkg.version);
  console.info("Usage: sclient  [--servername <string>] [-k | --insecure] <servername:port> <port>");
  console.info("   ex: sclient whatever.com 3000");
  console.info("       (whatever.com:443 localhost:3000)");
  console.info("   ex: sclient whatever.com:4080 0.0.0.0:3000");
  console.info("");
}

function parseFlags(argv) {
  var args = argv.slice();
  var flags = {};

  args.some(function (arg, i) {
    if (/^-k|--?insecure$/.test(arg)) {
      flags.rejectUnauthorized = false;
      args.splice(i, 1);
      return true;
    }
  });
  args.some(function (arg, i) {
    if (/^--?servername$/.test(arg)) {
      flags.servername = args[i + 1];
      if (!flags.servername || /^-/.test(flags.servername)) {
        usage();
        process.exit(2);
      }
      args.splice(i, 2);
      return true;
    }
  });
  args.some(function (arg, i) {
    if (/^--?p(ort)?$/.test(arg)) {
      flags.port = args[i + 1];
      if (!flags.port || /^-/.test(flags.port)) {
        usage();
        process.exit(201);
      }
      args.splice(i, 2);
      return true;
    }
  });
  args.some(function (arg, i) {
    if (/^--?ssh$/.test(arg)) {
      flags.wrapSsh = true;
      args.splice(i, 1);
      return true;
    }
  });
  args.some(function (arg, i) {
    if (/^--?socks5$/.test(arg)) {
      flags.socks5 = args[i + 1];
      if (!flags.socks5 || /^-/.test(flags.socks5)) {
        usage();
        process.exit(202);
      }
      args.splice(i, 2);
      return true;
    }
  });

  // This works for most (but not all)
  // of the ssh and rsync flags - because they mostly don't have arguments
  args.sort(function (a, b) {
    if ('-' === a[0]) {
      if ('-' === b[0]) {
        return 0;
      }
      return 1;
    }
    if ('-' === b[0]) {
      return -1;
    }
    return 0;
  });

  return {
    flags: flags
  , args: args
  };
}

var sclient = require('../');

function testRemote(opts) {
  var emitter = new (require('events').EventEmitter)();

  sclient._test(opts).then(function () {
    // connected successfully (and closed)
    sclient._listen(emitter, opts);
  }).catch(function (err) {
    // did not connect succesfully
    sclient._listen(emitter, opts);
    console.warn("[warn] '" + opts.remoteAddr + ":" + opts.remotePort
      + "' may not be accepting connections: ", err.toString(), '\n');
  });

  emitter.once('listening', function (opts) {
    console.info('[listening] ' + opts.remoteAddr + ":" + opts.remotePort
      + " <= " + opts.localAddress + ":" + opts.localPort);

    if (opts.command) {
      var args = [
        opts.remoteUser + 'localhost'
      , '-p', opts.localPort
      // we're _inverse_ proxying ssh, so we must alias the serveranem and ignore the IP
      , '-o', 'HostKeyAlias=' + opts.remoteAddr
      , '-o', 'CheckHostIP=no'
      ];
      var spawn = require('child_process').spawn;
      if ('rsync' === opts.command) {
        var remote = args.shift() + ':' + opts.remotePath;
        args = [ remote, '-e', 'ssh ' + args.join(' ') ];
      }
      if (opts.socks5) {
        args.push('-D');
        args.push('localhost:' + opts.socks5);
      }
      args = args.concat(opts.args);
      var child = spawn(opts.command, args, { stdio: 'inherit' });
      child.on('exit', function () {
        console.info('closing...');
      });
      child.on('close', function () {
        opts.server.close();
      });
    }
  });
  emitter.on('connect', function (sock) {
    console.info('[connect] ' + sock.localAddress.replace('::1', 'localhost') + ":" + sock.localPort
      + " => " + opts.remoteAddr + ":" + opts.remotePort);
  });
  emitter.on('remote-error', function (err) {
    console.error('[error] (remote) ' + err.toString());
  });
  emitter.on('local-error', function (err) {
    console.error('[error] (local) ' + err.toString());
  });
}

function main() {
  var cmd = parseFlags(process.argv);
  var binParam;
  var remoteUser;

  // Re-arrange argument order for ssh
  if (cmd.flags.wrapSsh) {
    cmd.args.splice(3, 0, 'ssh');
  } else if (-1 !== [ 'ssh', 'rsync', 'vpn' ].indexOf((cmd.args[2]||'').split(':')[0])) {
    cmd.flags.wrapSsh = true;
    binParam = cmd.args.splice(2, 1);
    cmd.args.splice(3, 0, binParam[0]);
  }

  remoteUser = (cmd.args[2]||'').split('@');
  if (remoteUser[1]) {
    // has 'user@' in front
    remote = (remoteUser[1]||'').split(':');
    remoteUser = remoteUser[0] + '@';
  } else {
    // no 'user@' in front
    remote = (remoteUser[0]||'').split(':');
    remoteUser = '';
  }
  local = (cmd.args[3]||'').split(':');

  if (-1 !== [ 'ssh', 'rsync', 'vpn' ].indexOf(local[0])) {
    cmd.flags.wrapSsh = true;
  }

  if (cmd.flags.wrapSsh) {
    process.argv = cmd.args;
  } else if (4 !== cmd.args.length) {
    // arg 0 is node
    // arg 1 is sclient
    // arg 2 is remote
    // arg 3 is local (or ssh or rsync)
    if (isPiped) {
      local = ['|'];
    } else {
      usage();
      process.exit(1);
    }
  }

  // Check for the first argument (what to connect to)
  if (!remote[0]) {
    usage();
    return;
  }

  if (!local[0]) {
    usage();
    return;
  }

  // check if it looks like a port number
  if (local[0] === String(parseInt(local[0], 10))) {
    localPort = parseInt(local[0], 10);
    localAddress = 'localhost';
  } else {
    localAddress = local[0]; // potentially '-' or '|' or '$'
    localPort = parseInt(local[1], 10);
  }

  var opts = {
    remoteUser: remoteUser
  , remoteAddr: remote[0]
  , remotePort: remote[1] || 443
  , localAddress: localAddress
  , localPort: localPort
  , rejectUnauthorized: cmd.flags.rejectUnauthorized
  , servername: cmd.flags.servername
  , stdin: null
  , stdout: null
  };

  if ('-' === localAddress || '|' === localAddress) {
    opts.stdin = process.stdin;
    opts.stdout = process.stdout;
    // no need for port
  } else if (-1 !== [ 'ssh', 'rsync', 'vpn' ].indexOf(localAddress)) {
    cmd.flags.wrapSsh = true;
    opts.localAddress = 'localhost';
    opts.localPort = local[1] || 0; // choose at random
    opts.command = localAddress;
    opts.args = cmd.args.slice(4); // node, sclient, ssh, addr
    opts.socks5 = cmd.flags.socks5;
    if ('rsync' === opts.command) {
      opts.remotePath = opts.remotePort;
      opts.remotePort = 0;
    }
    if ('vpn' === opts.command) {
      opts.command = 'ssh';
      if (!opts.socks5) {
        usage();
        return;
      }
    }
    if (!opts.remotePort) {
      opts.remotePort = cmd.flags.port || 443;
    }
  } else if (!localPort) {
    usage();
    return;
  }

  testRemote(opts);
}

main();