~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2007 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program 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 General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""A convenience class around smtplib."""

from email import Utils

import errno

import smtplib

import socket

from bzrlib import (

    config,

    osutils,

    )

from bzrlib.errors import (

    NoDestinationAddress,

    SMTPError,

    DefaultSMTPConnectionRefused,

    SMTPConnectionRefused,

    )

class SMTPConnection(object):

    """Connect to an SMTP server and send an email.

    This is a gateway between bzrlib.config.Config and smtplib.SMTP. It

    understands the basic bzr SMTP configuration information: smtp_server,

    smtp_username, and smtp_password.

    """

    _default_smtp_server = 'localhost'

    def __init__(self, config, _smtp_factory=None):

        self._smtp_factory = _smtp_factory

        if self._smtp_factory is None:

            self._smtp_factory = smtplib.SMTP

        self._config = config

        self._config_smtp_server = config.get_user_option('smtp_server')

        self._smtp_server = self._config_smtp_server

        if self._smtp_server is None:

            self._smtp_server = self._default_smtp_server

        self._smtp_username = config.get_user_option('smtp_username')

        self._smtp_password = config.get_user_option('smtp_password')

        self._connection = None

    def _connect(self):

        """If we haven't connected, connect and authenticate."""

        if self._connection is not None:

            return

        self._create_connection()

        # FIXME: _authenticate() should only be called when the server has

        # refused unauthenticated access, so it can safely try to authenticate 

        # with the default username. JRV20090407

        self._authenticate()

    def _create_connection(self):

        """Create an SMTP connection."""

        self._connection = self._smtp_factory()

        try:

            self._connection.connect(self._smtp_server)

        except socket.error, e:

            if e.args[0] == errno.ECONNREFUSED:

                if self._config_smtp_server is None:

                    raise DefaultSMTPConnectionRefused(socket.error,

                                                       self._smtp_server)

                else:

                    raise SMTPConnectionRefused(socket.error,

                                                self._smtp_server)

            else:

                raise

        # Say EHLO (falling back to HELO) to query the server's features.

        code, resp = self._connection.ehlo()

        if not (200 <= code <= 299):

            code, resp = self._connection.helo()

            if not (200 <= code <= 299):

                raise SMTPError("server refused HELO: %d %s" % (code, resp))

        # Use TLS if the server advertised it:

        if self._connection.has_extn("starttls"):

            code, resp = self._connection.starttls()

            if not (200 <= code <= 299):

                raise SMTPError("server refused STARTTLS: %d %s" % (code, resp))

            # Say EHLO again, to check for newly revealed features

            code, resp = self._connection.ehlo()

            if not (200 <= code <= 299):

                raise SMTPError("server refused EHLO: %d %s" % (code, resp))

    def _authenticate(self):

        """If necessary authenticate yourself to the server."""

        auth = config.AuthenticationConfig()

        if self._smtp_username is None:

            # FIXME: Since _authenticate gets called even when no authentication

            # is necessary, it's not possible to use the default username 

            # here yet.

            self._smtp_username = auth.get_user('smtp', self._smtp_server)

            if self._smtp_username is None:

                return

        if self._smtp_password is None:

            self._smtp_password = auth.get_password(

                'smtp', self._smtp_server, self._smtp_username)

        # smtplib requires that the username and password be byte

        # strings.  The CRAM-MD5 spec doesn't give any guidance on

        # encodings, but the SASL PLAIN spec says UTF-8, so that's

        # what we'll use.

        username = osutils.safe_utf8(self._smtp_username)

        password = osutils.safe_utf8(self._smtp_password)

        self._connection.login(username, password)

    @staticmethod

    def get_message_addresses(message):

        """Get the origin and destination addresses of a message.

        :param message: A message object supporting get() to access its

            headers, like email.Message or bzrlib.email_message.EmailMessage.

        :return: A pair (from_email, to_emails), where from_email is the email

            address in the From header, and to_emails a list of all the

            addresses in the To, Cc, and Bcc headers.

        """

        from_email = Utils.parseaddr(message.get('From', None))[1]

        to_full_addresses = []

        for header in ['To', 'Cc', 'Bcc']:

            value = message.get(header, None)

            if value:

                to_full_addresses.append(value)

        to_emails = [ pair[1] for pair in

                Utils.getaddresses(to_full_addresses) ]

        return from_email, to_emails

    def send_email(self, message):

        """Send an email message.

        The message will be sent to all addresses in the To, Cc and Bcc

        headers.

        :param message: An email.Message or email.MIMEMultipart object.

        :return: None

        """

        from_email, to_emails = self.get_message_addresses(message)

        if not to_emails:

            raise NoDestinationAddress

        try:

            self._connect()

            self._connection.sendmail(from_email, to_emails,

                                      message.as_string())

        except smtplib.SMTPRecipientsRefused, e:

            raise SMTPError('server refused recipient: %d %s' %

                    e.recipients.values()[0])

        except smtplib.SMTPResponseException, e:

            raise SMTPError('%d %s' % (e.smtp_code, e.smtp_error))

        except smtplib.SMTPException, e:

            raise SMTPError(str(e))