simple-ftpd

simple-ftpd is a event based ftp-server for node.js.

Features

• Supports multiple modern ftp clients such as FileZilla, WinSCP, Transmission.
• A real File System is not required.
• For now it only supports basic authentication.
• It supports passive mode only.
• It only supports streams for writing and reading files.
• It currently only supports a subset of FTP commands, but it should be enough for any modern FTP client.
• It is intended to be used mainly to create local network ftp servers.

Used pyftpdlib extensively as a reference for the FTP protocol specification, as reading RFC documents is super boring :=)

Install

yarn add simple-ftpd
# or
npm install simple-ftpd --save

const ftpd = require('simple-ftpd')

API

Syntax: ftpd(opts, sessionCallback) or ftpd(host:port, sessionCallback)

Should you need more control, the ftpd function will return a net.Server instance.

Example

Simple, fs-based ftp server implementation example:

'use strict'

const ftpd = require('simple-ftpd')

ftpd({ host: '127.0.0.1', port: 1337, root: '/public/files' }, (session) => {

  session.on('pass', (username, password, cb) => {
    if (username === 'superadmin' && password === '53cr3t') {
      session.readOnly = false
      session.root = '/private/secret/files'
      cb(null, 'Welcome admin')
    } else {
      cb(null, 'Welcome guest')
    }
  })

  session.on('stat', fs.stat)
  // AKA
  // session.on('stat', (pathName, cb) => {
  //  fs.stat(pathName, cb)
  // })

  session.on('readdir', fs.readdir)
  // AKA
  // session.on('readdir', (pathName, cb) => {
  //   fs.readdir(pathName, cb)
  // })

  session.on('read', (pathName, offset, cb) => {
    cb(null, fs.createReadStream(pathName, { start: offset }))
  })

  session.on('write', (pathName, offset, cb) => {
    cb(null, fs.createWriteStream(pathName, { start: offset }))
  })

  // I'd do some checking if I were you, but hey.

  session.on('mkdir', fs.mkdir)
  session.on('unlink', fs.unlink)
  session.on('rename', fs.rename)
  session.on('remove', require('rimraf'))
})

Options

| option | | description | | --- | --- | --- | | host | required | Must be a valid ipv4 address (for now). Defaults to 127.0.0.1 | | port | required | Server port. Defaults to 1337. | | readOnly | optional | Disables client write requests. Defaults to true. Can be overridden on a connection-basis by setting the readOnly property on the session object before logging in. | | root | optional | The path passed to events will always be joined to root. Can be overridden on a connection-basis by setting the root property on the session object before logging in. The ftp client will not see root, and will think he's at /. This is simply a convenience to avoid manually joining the path you get in every event. | | maxConnections | optional | Maximum number of server connections. Defaults to 10. |

Passive connections will be initialized on an unused port assigned by the os.

Instead of options, you can pass ${host}:${port} ("192.168.1.10:1337").

Events

Every event gets some arguments and a node-style callback you must call with an Error object (if any) and results.

If you do not listen to a specific event, then that feature will become unavailable to the client. For example, if you do not listen to write events, the client will get a 502 error when trying to write files.

pass [username, password, cb]

The client wants to login with username and password. Will consider the user logged in if no error is passed to cb()

User names are always accepted, because (from pyftpdlib):

In order to prevent a malicious client from determining valid usernames on a server, it is suggested by RFC-2577 that a server always return 331 to the USER command and then reject the combination of username and password for an invalid username when PASS is provided later.

read [pathName, offset, cb]:

The client wants to read the file at pathName, starting at offset. Requires a readable stream to be passed as cb(null, readStream).

write [pathName, offset, cb]:

The client wants to write a file at pathName, starting at offset. Requires a writable stream to be passed as cb(null, writeStream).

stat [pathName, cb]:

the client wants the stats to a file or directory at pathName. Requires a fs.stat-like object to be passed as cb(null, stat).

Properties are:

{
  // fs.stat mode
  mode: 16822,
  //  size in bytes
  size: 12345,
  // lastModifiedTime as Date or number (or whatever gets parsed by moment)
  mtime: Date.now(),
  // optional, will use it for display if available, otherwise "owner"
  uname: 'kamicane',
  // optional, will use it for display if available, otherwise "group"
  gname: 'admins',
}

readdir [pathName, cb]:

The client wants a list of files in the directory pathName. requires an array of file names, relative to pathName, to be passed as cb(null, list).

mkdir [pathName, cb]:

The client wants to create a directory at pathName. Will consider the directory written if no error is passed to cb()

unlink [pathName, cb]:

The client wants to delete the file at pathName. Will consider the file deleted if no error is passed to cb()

remove [pathName, cb]:

The client wants to remove a directory, and all of its contents, at pathName. Will consider the directory and its contents removed if no error is passed to cb()

rename [fromName, toName, cb]:

The client wants to rename a file or directory, from fromName to toName. Will consider the file renamed if no error is passed to cb()

CLI

When installed globally, ftpd will provide a small cli, which will quickly create a fs-based ftp server.

You can use it like this:

ftp-server /public/files --host 192.168.0.1 --port 1234 --max-connections 10

• --host will default to 127.0.0.1
• --port will default to 1337
• --max-connections will default to 10
• --read-only will default to true
• Unless specified, the ftp root will default to process.cwd()

The cli will accept any login, so be careful when setting --read-only to false.

License

MIT