用twisted实现的简单ftp服务端

因工作需要，最近写了个twisted的ftp服务端。用户验证用的是django

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""a very simple ftp server by twisted
"""

__author__ = "Bobning([e-mail])"


import sys, os
sys.path.append('../../..')
os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'

from twisted.protocols import ftp
from twisted.cred import portal, checkers, credentials, error as credError
from twisted.internet import reactor, defer
from zope.interface import implements
from twisted.python import filepath
from django.contrib.auth import authenticate
from django.contrib.auth.models import User


class UserChecker:
    implements(checkers.ICredentialsChecker)
    credentialInterfaces = (credentials.IUsernamePassword,)
    
    def __init__(self):
        "passwords: a dict-like object mapping usernames to passwords"

    
    def requestAvatarId(self, credentials):
        user = authenticate(username=credentials.username, password=credentials.password)
        if user is not None:
            if user.is_active:
                return defer.succeed(credentials.username)
            else:
                return defer.fail(credError.UnauthorizedLogin("access denied"))
        else:
            return defer.fail(credError.UnauthorizedLogin("No such user"))


class MyFTPRealm:
    implements(portal.IRealm)
    
    def __init__(self, anonymousRoot):
        self.anonymousRoot = filepath.FilePath(anonymousRoot)
    
    def requestAvatar(self, avatarId, mind, *interfaces):
        for iface in interfaces:
            if iface is ftp.IFTPShell:
                if avatarId is checkers.ANONYMOUS:
                    avatar = ftp.FTPAnonymousShell(self.anonymousRoot)
                else:
                    try:
                        user = User.objects.get(username=avatarId)
                        ftpdir = user.ftp.all()[0].ftpdir
                    except:
                        raise "没有该用户"
                    avatar = ftp.FTPShell(filepath.FilePath(ftpdir.encode("utf-8")))
                return ftp.IFTPShell, avatar, getattr(avatar, "logout", lambda:None)
        raise NotImplementedError("only IFTPShell interface is supported by this realm")


class MyFtpServer(ftp.FTP):
    def __init__(self, *args, **kw):
        super(ftp.FTP, self).__init__(*args, **kw)

    def dataReceived(self, data):
        self.transport.write(data)


if __name__ == "__main__":
    p = portal.Portal(MyFTPRealm(""))
    p.registerChecker(UserChecker())

    factory = ftp.FTPFactory(MyFtpServer())
    factory.portal = p
    reactor.listenTCP(2121, factory)
    reactor.run()