postfix.py   [plain text]

# -*- test-case-name: twisted.test.test_postfix -*-
#
# Twisted, the Framework of Your Internet
# Copyright (C) 2001-2003 Matthew W. Lefkowitz
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

"""Postfix mail transport agent related protocols."""

import sys

# Twisted imports
from twisted.protocols import basic
from twisted.protocols import policies
from twisted.internet import protocol, defer, reactor
from twisted.python import log
import UserDict
import urllib

# urllib's quote functions just happen to match
# the postfix semantics.

def quote(s):
    return urllib.quote(s)

def unquote(s):
    return urllib.unquote(s)

class PostfixTCPMapServer(basic.LineReceiver, policies.TimeoutMixin):
    """Postfix mail transport agent TCP map protocol implementation.

    Receive requests for data matching given key via lineReceived,
    asks it's factory for the data with self.factory.get(key), and
    returns the data to the requester. None means no entry found.

    You can use postfix's postmap to test the map service::

    /usr/sbin/postmap -q KEY tcp:localhost:4242

    """

    timeout = 600
    delimiter = '\n'

    def connectionMade(self):
        self.setTimeout(self.timeout)

    def sendCode(self, code, message=''):
        "Send an SMTP-like code with a message."
        self.sendLine('%3.3d %s' % (code, message or ''))

    def lineReceived(self, line):
        self.resetTimeout()
        try:
            request, params = line.split(None, 1)
        except ValueError:
            request = line
            params = None
        try:
            f = getattr(self, 'do_' + request)
        except AttributeError:
            self.sendCode(400, 'unknown command')
        else:
            try:
                f(params)
            except:
                self.sendCode(400, 'Command %r failed: %s.' % (request, sys.exc_value))

    def do_get(self, key):
        if key is None:
            self.sendCode(400, 'Command %r takes 1 parameters.' % 'get')
        else:
            d = defer.maybeDeferred(self.factory.get, key)
            d.addCallbacks(self._cbGot, self._cbNot)
            d.addErrback(log.err)

    def _cbNot(self, fail):
        self.sendCode(400, fail.getErrorMessage())

    def _cbGot(self, value):
        if value is None:
            self.sendCode(500)
        else:
            self.sendCode(200, quote(value))

    def do_put(self, keyAndValue):
        if keyAndValue is None:
            self.sendCode(400, 'Command %r takes 2 parameters.' % 'put')
        else:
            try:
                key, value = keyAndValue.split(None, 1)
            except ValueError:
                self.sendCode(400, 'Command %r takes 2 parameters.' % 'put')
            else:
                self.sendCode(500, 'put is not implemented yet.')


class PostfixTCPMapDictServerFactory(protocol.ServerFactory,
                                     UserDict.UserDict):
    """An in-memory dictionary factory for PostfixTCPMapServer."""

    protocol = PostfixTCPMapServer

class PostfixTCPMapDeferringDictServerFactory(protocol.ServerFactory):
    """An in-memory dictionary factory for PostfixTCPMapServer."""

    protocol = PostfixTCPMapServer

    def __init__(self, data=None):
        self.data = {}
        if data is not None:
            self.data.update(data)

    def get(self, key):
        d = defer.Deferred()
        reactor.callLater(0, d.callback, self.data.get(key))
        return d

if __name__ == '__main__':
    """Test app for PostfixTCPMapServer. Call with parameters
    KEY1=VAL1 KEY2=VAL2 ..."""
    from twisted.internet import reactor
    from twisted.python import log
    import sys
    log.startLogging(sys.stdout)
    d = {}
    for arg in sys.argv[1:]:
        try:
            k,v = arg.split('=', 1)
        except ValueError:
            k = arg
            v = ''
        d[k]=v
    f=PostfixTCPMapDictServerFactory(d)
    port = reactor.listenTCP(4242, f, interface='127.0.0.1')
    reactor.run()