| #! /usr/bin/env python3 |
| """An RFC 5321 smtp proxy with optional RFC 1870 and RFC 6531 extensions. |
| |
| Usage: %(program)s [options] [localhost:localport [remotehost:remoteport]] |
| |
| Options: |
| |
| --nosetuid |
| -n |
| This program generally tries to setuid `nobody', unless this flag is |
| set. The setuid call will fail if this program is not run as root (in |
| which case, use this flag). |
| |
| --version |
| -V |
| Print the version number and exit. |
| |
| --class classname |
| -c classname |
| Use `classname' as the concrete SMTP proxy class. Uses `PureProxy' by |
| default. |
| |
| --size limit |
| -s limit |
| Restrict the total size of the incoming message to "limit" number of |
| bytes via the RFC 1870 SIZE extension. Defaults to 33554432 bytes. |
| |
| --smtputf8 |
| -u |
| Enable the SMTPUTF8 extension and behave as an RFC 6531 smtp proxy. |
| |
| --debug |
| -d |
| Turn on debugging prints. |
| |
| --help |
| -h |
| Print this message and exit. |
| |
| Version: %(__version__)s |
| |
| If localhost is not given then `localhost' is used, and if localport is not |
| given then 8025 is used. If remotehost is not given then `localhost' is used, |
| and if remoteport is not given, then 25 is used. |
| """ |
| |
| # Overview: |
| # |
| # This file implements the minimal SMTP protocol as defined in RFC 5321. It |
| # has a hierarchy of classes which implement the backend functionality for the |
| # smtpd. A number of classes are provided: |
| # |
| # SMTPServer - the base class for the backend. Raises NotImplementedError |
| # if you try to use it. |
| # |
| # DebuggingServer - simply prints each message it receives on stdout. |
| # |
| # PureProxy - Proxies all messages to a real smtpd which does final |
| # delivery. One known problem with this class is that it doesn't handle |
| # SMTP errors from the backend server at all. This should be fixed |
| # (contributions are welcome!). |
| # |
| # MailmanProxy - An experimental hack to work with GNU Mailman |
| # <www.list.org>. Using this server as your real incoming smtpd, your |
| # mailhost will automatically recognize and accept mail destined to Mailman |
| # lists when those lists are created. Every message not destined for a list |
| # gets forwarded to a real backend smtpd, as with PureProxy. Again, errors |
| # are not handled correctly yet. |
| # |
| # |
| # Author: Barry Warsaw <barry@python.org> |
| # |
| # TODO: |
| # |
| # - support mailbox delivery |
| # - alias files |
| # - Handle more ESMTP extensions |
| # - handle error codes from the backend smtpd |
| |
| import sys |
| import os |
| import errno |
| import getopt |
| import time |
| import socket |
| import asyncore |
| import asynchat |
| import collections |
| from warnings import warn |
| from email._header_value_parser import get_addr_spec, get_angle_addr |
| |
| __all__ = [ |
| "SMTPChannel", "SMTPServer", "DebuggingServer", "PureProxy", |
| "MailmanProxy", |
| ] |
| |
| program = sys.argv[0] |
| __version__ = 'Python SMTP proxy version 0.3' |
| |
| |
| class Devnull: |
| def write(self, msg): pass |
| def flush(self): pass |
| |
| |
| DEBUGSTREAM = Devnull() |
| NEWLINE = '\n' |
| COMMASPACE = ', ' |
| DATA_SIZE_DEFAULT = 33554432 |
| |
| |
| def usage(code, msg=''): |
| print(__doc__ % globals(), file=sys.stderr) |
| if msg: |
| print(msg, file=sys.stderr) |
| sys.exit(code) |
| |
| |
| class SMTPChannel(asynchat.async_chat): |
| COMMAND = 0 |
| DATA = 1 |
| |
| command_size_limit = 512 |
| command_size_limits = collections.defaultdict(lambda x=command_size_limit: x) |
| |
| @property |
| def max_command_size_limit(self): |
| try: |
| return max(self.command_size_limits.values()) |
| except ValueError: |
| return self.command_size_limit |
| |
| def __init__(self, server, conn, addr, data_size_limit=DATA_SIZE_DEFAULT, |
| map=None, enable_SMTPUTF8=False, decode_data=False): |
| asynchat.async_chat.__init__(self, conn, map=map) |
| self.smtp_server = server |
| self.conn = conn |
| self.addr = addr |
| self.data_size_limit = data_size_limit |
| self.enable_SMTPUTF8 = enable_SMTPUTF8 |
| self._decode_data = decode_data |
| if enable_SMTPUTF8 and decode_data: |
| raise ValueError("decode_data and enable_SMTPUTF8 cannot" |
| " be set to True at the same time") |
| if decode_data: |
| self._emptystring = '' |
| self._linesep = '\r\n' |
| self._dotsep = '.' |
| self._newline = NEWLINE |
| else: |
| self._emptystring = b'' |
| self._linesep = b'\r\n' |
| self._dotsep = ord(b'.') |
| self._newline = b'\n' |
| self._set_rset_state() |
| self.seen_greeting = '' |
| self.extended_smtp = False |
| self.command_size_limits.clear() |
| self.fqdn = socket.getfqdn() |
| try: |
| self.peer = conn.getpeername() |
| except OSError as err: |
| # a race condition may occur if the other end is closing |
| # before we can get the peername |
| self.close() |
| if err.args[0] != errno.ENOTCONN: |
| raise |
| return |
| print('Peer:', repr(self.peer), file=DEBUGSTREAM) |
| self.push('220 %s %s' % (self.fqdn, __version__)) |
| |
| def _set_post_data_state(self): |
| """Reset state variables to their post-DATA state.""" |
| self.smtp_state = self.COMMAND |
| self.mailfrom = None |
| self.rcpttos = [] |
| self.require_SMTPUTF8 = False |
| self.num_bytes = 0 |
| self.set_terminator(b'\r\n') |
| |
| def _set_rset_state(self): |
| """Reset all state variables except the greeting.""" |
| self._set_post_data_state() |
| self.received_data = '' |
| self.received_lines = [] |
| |
| |
| # properties for backwards-compatibility |
| @property |
| def __server(self): |
| warn("Access to __server attribute on SMTPChannel is deprecated, " |
| "use 'smtp_server' instead", DeprecationWarning, 2) |
| return self.smtp_server |
| @__server.setter |
| def __server(self, value): |
| warn("Setting __server attribute on SMTPChannel is deprecated, " |
| "set 'smtp_server' instead", DeprecationWarning, 2) |
| self.smtp_server = value |
| |
| @property |
| def __line(self): |
| warn("Access to __line attribute on SMTPChannel is deprecated, " |
| "use 'received_lines' instead", DeprecationWarning, 2) |
| return self.received_lines |
| @__line.setter |
| def __line(self, value): |
| warn("Setting __line attribute on SMTPChannel is deprecated, " |
| "set 'received_lines' instead", DeprecationWarning, 2) |
| self.received_lines = value |
| |
| @property |
| def __state(self): |
| warn("Access to __state attribute on SMTPChannel is deprecated, " |
| "use 'smtp_state' instead", DeprecationWarning, 2) |
| return self.smtp_state |
| @__state.setter |
| def __state(self, value): |
| warn("Setting __state attribute on SMTPChannel is deprecated, " |
| "set 'smtp_state' instead", DeprecationWarning, 2) |
| self.smtp_state = value |
| |
| @property |
| def __greeting(self): |
| warn("Access to __greeting attribute on SMTPChannel is deprecated, " |
| "use 'seen_greeting' instead", DeprecationWarning, 2) |
| return self.seen_greeting |
| @__greeting.setter |
| def __greeting(self, value): |
| warn("Setting __greeting attribute on SMTPChannel is deprecated, " |
| "set 'seen_greeting' instead", DeprecationWarning, 2) |
| self.seen_greeting = value |
| |
| @property |
| def __mailfrom(self): |
| warn("Access to __mailfrom attribute on SMTPChannel is deprecated, " |
| "use 'mailfrom' instead", DeprecationWarning, 2) |
| return self.mailfrom |
| @__mailfrom.setter |
| def __mailfrom(self, value): |
| warn("Setting __mailfrom attribute on SMTPChannel is deprecated, " |
| "set 'mailfrom' instead", DeprecationWarning, 2) |
| self.mailfrom = value |
| |
| @property |
| def __rcpttos(self): |
| warn("Access to __rcpttos attribute on SMTPChannel is deprecated, " |
| "use 'rcpttos' instead", DeprecationWarning, 2) |
| return self.rcpttos |
| @__rcpttos.setter |
| def __rcpttos(self, value): |
| warn("Setting __rcpttos attribute on SMTPChannel is deprecated, " |
| "set 'rcpttos' instead", DeprecationWarning, 2) |
| self.rcpttos = value |
| |
| @property |
| def __data(self): |
| warn("Access to __data attribute on SMTPChannel is deprecated, " |
| "use 'received_data' instead", DeprecationWarning, 2) |
| return self.received_data |
| @__data.setter |
| def __data(self, value): |
| warn("Setting __data attribute on SMTPChannel is deprecated, " |
| "set 'received_data' instead", DeprecationWarning, 2) |
| self.received_data = value |
| |
| @property |
| def __fqdn(self): |
| warn("Access to __fqdn attribute on SMTPChannel is deprecated, " |
| "use 'fqdn' instead", DeprecationWarning, 2) |
| return self.fqdn |
| @__fqdn.setter |
| def __fqdn(self, value): |
| warn("Setting __fqdn attribute on SMTPChannel is deprecated, " |
| "set 'fqdn' instead", DeprecationWarning, 2) |
| self.fqdn = value |
| |
| @property |
| def __peer(self): |
| warn("Access to __peer attribute on SMTPChannel is deprecated, " |
| "use 'peer' instead", DeprecationWarning, 2) |
| return self.peer |
| @__peer.setter |
| def __peer(self, value): |
| warn("Setting __peer attribute on SMTPChannel is deprecated, " |
| "set 'peer' instead", DeprecationWarning, 2) |
| self.peer = value |
| |
| @property |
| def __conn(self): |
| warn("Access to __conn attribute on SMTPChannel is deprecated, " |
| "use 'conn' instead", DeprecationWarning, 2) |
| return self.conn |
| @__conn.setter |
| def __conn(self, value): |
| warn("Setting __conn attribute on SMTPChannel is deprecated, " |
| "set 'conn' instead", DeprecationWarning, 2) |
| self.conn = value |
| |
| @property |
| def __addr(self): |
| warn("Access to __addr attribute on SMTPChannel is deprecated, " |
| "use 'addr' instead", DeprecationWarning, 2) |
| return self.addr |
| @__addr.setter |
| def __addr(self, value): |
| warn("Setting __addr attribute on SMTPChannel is deprecated, " |
| "set 'addr' instead", DeprecationWarning, 2) |
| self.addr = value |
| |
| # Overrides base class for convenience. |
| def push(self, msg): |
| asynchat.async_chat.push(self, bytes( |
| msg + '\r\n', 'utf-8' if self.require_SMTPUTF8 else 'ascii')) |
| |
| # Implementation of base class abstract method |
| def collect_incoming_data(self, data): |
| limit = None |
| if self.smtp_state == self.COMMAND: |
| limit = self.max_command_size_limit |
| elif self.smtp_state == self.DATA: |
| limit = self.data_size_limit |
| if limit and self.num_bytes > limit: |
| return |
| elif limit: |
| self.num_bytes += len(data) |
| if self._decode_data: |
| self.received_lines.append(str(data, 'utf-8')) |
| else: |
| self.received_lines.append(data) |
| |
| # Implementation of base class abstract method |
| def found_terminator(self): |
| line = self._emptystring.join(self.received_lines) |
| print('Data:', repr(line), file=DEBUGSTREAM) |
| self.received_lines = [] |
| if self.smtp_state == self.COMMAND: |
| sz, self.num_bytes = self.num_bytes, 0 |
| if not line: |
| self.push('500 Error: bad syntax') |
| return |
| if not self._decode_data: |
| line = str(line, 'utf-8') |
| i = line.find(' ') |
| if i < 0: |
| command = line.upper() |
| arg = None |
| else: |
| command = line[:i].upper() |
| arg = line[i+1:].strip() |
| max_sz = (self.command_size_limits[command] |
| if self.extended_smtp else self.command_size_limit) |
| if sz > max_sz: |
| self.push('500 Error: line too long') |
| return |
| method = getattr(self, 'smtp_' + command, None) |
| if not method: |
| self.push('500 Error: command "%s" not recognized' % command) |
| return |
| method(arg) |
| return |
| else: |
| if self.smtp_state != self.DATA: |
| self.push('451 Internal confusion') |
| self.num_bytes = 0 |
| return |
| if self.data_size_limit and self.num_bytes > self.data_size_limit: |
| self.push('552 Error: Too much mail data') |
| self.num_bytes = 0 |
| return |
| # Remove extraneous carriage returns and de-transparency according |
| # to RFC 5321, Section 4.5.2. |
| data = [] |
| for text in line.split(self._linesep): |
| if text and text[0] == self._dotsep: |
| data.append(text[1:]) |
| else: |
| data.append(text) |
| self.received_data = self._newline.join(data) |
| args = (self.peer, self.mailfrom, self.rcpttos, self.received_data) |
| kwargs = {} |
| if not self._decode_data: |
| kwargs = { |
| 'mail_options': self.mail_options, |
| 'rcpt_options': self.rcpt_options, |
| } |
| status = self.smtp_server.process_message(*args, **kwargs) |
| self._set_post_data_state() |
| if not status: |
| self.push('250 OK') |
| else: |
| self.push(status) |
| |
| # SMTP and ESMTP commands |
| def smtp_HELO(self, arg): |
| if not arg: |
| self.push('501 Syntax: HELO hostname') |
| return |
| # See issue #21783 for a discussion of this behavior. |
| if self.seen_greeting: |
| self.push('503 Duplicate HELO/EHLO') |
| return |
| self._set_rset_state() |
| self.seen_greeting = arg |
| self.push('250 %s' % self.fqdn) |
| |
| def smtp_EHLO(self, arg): |
| if not arg: |
| self.push('501 Syntax: EHLO hostname') |
| return |
| # See issue #21783 for a discussion of this behavior. |
| if self.seen_greeting: |
| self.push('503 Duplicate HELO/EHLO') |
| return |
| self._set_rset_state() |
| self.seen_greeting = arg |
| self.extended_smtp = True |
| self.push('250-%s' % self.fqdn) |
| if self.data_size_limit: |
| self.push('250-SIZE %s' % self.data_size_limit) |
| self.command_size_limits['MAIL'] += 26 |
| if not self._decode_data: |
| self.push('250-8BITMIME') |
| if self.enable_SMTPUTF8: |
| self.push('250-SMTPUTF8') |
| self.command_size_limits['MAIL'] += 10 |
| self.push('250 HELP') |
| |
| def smtp_NOOP(self, arg): |
| if arg: |
| self.push('501 Syntax: NOOP') |
| else: |
| self.push('250 OK') |
| |
| def smtp_QUIT(self, arg): |
| # args is ignored |
| self.push('221 Bye') |
| self.close_when_done() |
| |
| def _strip_command_keyword(self, keyword, arg): |
| keylen = len(keyword) |
| if arg[:keylen].upper() == keyword: |
| return arg[keylen:].strip() |
| return '' |
| |
| def _getaddr(self, arg): |
| if not arg: |
| return '', '' |
| if arg.lstrip().startswith('<'): |
| address, rest = get_angle_addr(arg) |
| else: |
| address, rest = get_addr_spec(arg) |
| if not address: |
| return address, rest |
| return address.addr_spec, rest |
| |
| def _getparams(self, params): |
| # Return params as dictionary. Return None if not all parameters |
| # appear to be syntactically valid according to RFC 1869. |
| result = {} |
| for param in params: |
| param, eq, value = param.partition('=') |
| if not param.isalnum() or eq and not value: |
| return None |
| result[param] = value if eq else True |
| return result |
| |
| def smtp_HELP(self, arg): |
| if arg: |
| extended = ' [SP <mail-parameters>]' |
| lc_arg = arg.upper() |
| if lc_arg == 'EHLO': |
| self.push('250 Syntax: EHLO hostname') |
| elif lc_arg == 'HELO': |
| self.push('250 Syntax: HELO hostname') |
| elif lc_arg == 'MAIL': |
| msg = '250 Syntax: MAIL FROM: <address>' |
| if self.extended_smtp: |
| msg += extended |
| self.push(msg) |
| elif lc_arg == 'RCPT': |
| msg = '250 Syntax: RCPT TO: <address>' |
| if self.extended_smtp: |
| msg += extended |
| self.push(msg) |
| elif lc_arg == 'DATA': |
| self.push('250 Syntax: DATA') |
| elif lc_arg == 'RSET': |
| self.push('250 Syntax: RSET') |
| elif lc_arg == 'NOOP': |
| self.push('250 Syntax: NOOP') |
| elif lc_arg == 'QUIT': |
| self.push('250 Syntax: QUIT') |
| elif lc_arg == 'VRFY': |
| self.push('250 Syntax: VRFY <address>') |
| else: |
| self.push('501 Supported commands: EHLO HELO MAIL RCPT ' |
| 'DATA RSET NOOP QUIT VRFY') |
| else: |
| self.push('250 Supported commands: EHLO HELO MAIL RCPT DATA ' |
| 'RSET NOOP QUIT VRFY') |
| |
| def smtp_VRFY(self, arg): |
| if arg: |
| address, params = self._getaddr(arg) |
| if address: |
| self.push('252 Cannot VRFY user, but will accept message ' |
| 'and attempt delivery') |
| else: |
| self.push('502 Could not VRFY %s' % arg) |
| else: |
| self.push('501 Syntax: VRFY <address>') |
| |
| def smtp_MAIL(self, arg): |
| if not self.seen_greeting: |
| self.push('503 Error: send HELO first') |
| return |
| print('===> MAIL', arg, file=DEBUGSTREAM) |
| syntaxerr = '501 Syntax: MAIL FROM: <address>' |
| if self.extended_smtp: |
| syntaxerr += ' [SP <mail-parameters>]' |
| if arg is None: |
| self.push(syntaxerr) |
| return |
| arg = self._strip_command_keyword('FROM:', arg) |
| address, params = self._getaddr(arg) |
| if not address: |
| self.push(syntaxerr) |
| return |
| if not self.extended_smtp and params: |
| self.push(syntaxerr) |
| return |
| if self.mailfrom: |
| self.push('503 Error: nested MAIL command') |
| return |
| self.mail_options = params.upper().split() |
| params = self._getparams(self.mail_options) |
| if params is None: |
| self.push(syntaxerr) |
| return |
| if not self._decode_data: |
| body = params.pop('BODY', '7BIT') |
| if body not in ['7BIT', '8BITMIME']: |
| self.push('501 Error: BODY can only be one of 7BIT, 8BITMIME') |
| return |
| if self.enable_SMTPUTF8: |
| smtputf8 = params.pop('SMTPUTF8', False) |
| if smtputf8 is True: |
| self.require_SMTPUTF8 = True |
| elif smtputf8 is not False: |
| self.push('501 Error: SMTPUTF8 takes no arguments') |
| return |
| size = params.pop('SIZE', None) |
| if size: |
| if not size.isdigit(): |
| self.push(syntaxerr) |
| return |
| elif self.data_size_limit and int(size) > self.data_size_limit: |
| self.push('552 Error: message size exceeds fixed maximum message size') |
| return |
| if len(params.keys()) > 0: |
| self.push('555 MAIL FROM parameters not recognized or not implemented') |
| return |
| self.mailfrom = address |
| print('sender:', self.mailfrom, file=DEBUGSTREAM) |
| self.push('250 OK') |
| |
| def smtp_RCPT(self, arg): |
| if not self.seen_greeting: |
| self.push('503 Error: send HELO first'); |
| return |
| print('===> RCPT', arg, file=DEBUGSTREAM) |
| if not self.mailfrom: |
| self.push('503 Error: need MAIL command') |
| return |
| syntaxerr = '501 Syntax: RCPT TO: <address>' |
| if self.extended_smtp: |
| syntaxerr += ' [SP <mail-parameters>]' |
| if arg is None: |
| self.push(syntaxerr) |
| return |
| arg = self._strip_command_keyword('TO:', arg) |
| address, params = self._getaddr(arg) |
| if not address: |
| self.push(syntaxerr) |
| return |
| if not self.extended_smtp and params: |
| self.push(syntaxerr) |
| return |
| self.rcpt_options = params.upper().split() |
| params = self._getparams(self.rcpt_options) |
| if params is None: |
| self.push(syntaxerr) |
| return |
| # XXX currently there are no options we recognize. |
| if len(params.keys()) > 0: |
| self.push('555 RCPT TO parameters not recognized or not implemented') |
| return |
| self.rcpttos.append(address) |
| print('recips:', self.rcpttos, file=DEBUGSTREAM) |
| self.push('250 OK') |
| |
| def smtp_RSET(self, arg): |
| if arg: |
| self.push('501 Syntax: RSET') |
| return |
| self._set_rset_state() |
| self.push('250 OK') |
| |
| def smtp_DATA(self, arg): |
| if not self.seen_greeting: |
| self.push('503 Error: send HELO first'); |
| return |
| if not self.rcpttos: |
| self.push('503 Error: need RCPT command') |
| return |
| if arg: |
| self.push('501 Syntax: DATA') |
| return |
| self.smtp_state = self.DATA |
| self.set_terminator(b'\r\n.\r\n') |
| self.push('354 End data with <CR><LF>.<CR><LF>') |
| |
| # Commands that have not been implemented |
| def smtp_EXPN(self, arg): |
| self.push('502 EXPN not implemented') |
| |
| |
| class SMTPServer(asyncore.dispatcher): |
| # SMTPChannel class to use for managing client connections |
| channel_class = SMTPChannel |
| |
| def __init__(self, localaddr, remoteaddr, |
| data_size_limit=DATA_SIZE_DEFAULT, map=None, |
| enable_SMTPUTF8=False, decode_data=False): |
| self._localaddr = localaddr |
| self._remoteaddr = remoteaddr |
| self.data_size_limit = data_size_limit |
| self.enable_SMTPUTF8 = enable_SMTPUTF8 |
| self._decode_data = decode_data |
| if enable_SMTPUTF8 and decode_data: |
| raise ValueError("decode_data and enable_SMTPUTF8 cannot" |
| " be set to True at the same time") |
| asyncore.dispatcher.__init__(self, map=map) |
| try: |
| gai_results = socket.getaddrinfo(*localaddr, |
| type=socket.SOCK_STREAM) |
| self.create_socket(gai_results[0][0], gai_results[0][1]) |
| # try to re-use a server port if possible |
| self.set_reuse_addr() |
| self.bind(localaddr) |
| self.listen(5) |
| except: |
| self.close() |
| raise |
| else: |
| print('%s started at %s\n\tLocal addr: %s\n\tRemote addr:%s' % ( |
| self.__class__.__name__, time.ctime(time.time()), |
| localaddr, remoteaddr), file=DEBUGSTREAM) |
| |
| def handle_accepted(self, conn, addr): |
| print('Incoming connection from %s' % repr(addr), file=DEBUGSTREAM) |
| channel = self.channel_class(self, |
| conn, |
| addr, |
| self.data_size_limit, |
| self._map, |
| self.enable_SMTPUTF8, |
| self._decode_data) |
| |
| # API for "doing something useful with the message" |
| def process_message(self, peer, mailfrom, rcpttos, data, **kwargs): |
| """Override this abstract method to handle messages from the client. |
| |
| peer is a tuple containing (ipaddr, port) of the client that made the |
| socket connection to our smtp port. |
| |
| mailfrom is the raw address the client claims the message is coming |
| from. |
| |
| rcpttos is a list of raw addresses the client wishes to deliver the |
| message to. |
| |
| data is a string containing the entire full text of the message, |
| headers (if supplied) and all. It has been `de-transparencied' |
| according to RFC 821, Section 4.5.2. In other words, a line |
| containing a `.' followed by other text has had the leading dot |
| removed. |
| |
| kwargs is a dictionary containing additional information. It is |
| empty if decode_data=True was given as init parameter, otherwise |
| it will contain the following keys: |
| 'mail_options': list of parameters to the mail command. All |
| elements are uppercase strings. Example: |
| ['BODY=8BITMIME', 'SMTPUTF8']. |
| 'rcpt_options': same, for the rcpt command. |
| |
| This function should return None for a normal `250 Ok' response; |
| otherwise, it should return the desired response string in RFC 821 |
| format. |
| |
| """ |
| raise NotImplementedError |
| |
| |
| class DebuggingServer(SMTPServer): |
| |
| def _print_message_content(self, peer, data): |
| inheaders = 1 |
| lines = data.splitlines() |
| for line in lines: |
| # headers first |
| if inheaders and not line: |
| peerheader = 'X-Peer: ' + peer[0] |
| if not isinstance(data, str): |
| # decoded_data=false; make header match other binary output |
| peerheader = repr(peerheader.encode('utf-8')) |
| print(peerheader) |
| inheaders = 0 |
| if not isinstance(data, str): |
| # Avoid spurious 'str on bytes instance' warning. |
| line = repr(line) |
| print(line) |
| |
| def process_message(self, peer, mailfrom, rcpttos, data, **kwargs): |
| print('---------- MESSAGE FOLLOWS ----------') |
| if kwargs: |
| if kwargs.get('mail_options'): |
| print('mail options: %s' % kwargs['mail_options']) |
| if kwargs.get('rcpt_options'): |
| print('rcpt options: %s\n' % kwargs['rcpt_options']) |
| self._print_message_content(peer, data) |
| print('------------ END MESSAGE ------------') |
| |
| |
| class PureProxy(SMTPServer): |
| def __init__(self, *args, **kwargs): |
| if 'enable_SMTPUTF8' in kwargs and kwargs['enable_SMTPUTF8']: |
| raise ValueError("PureProxy does not support SMTPUTF8.") |
| super(PureProxy, self).__init__(*args, **kwargs) |
| |
| def process_message(self, peer, mailfrom, rcpttos, data): |
| lines = data.split('\n') |
| # Look for the last header |
| i = 0 |
| for line in lines: |
| if not line: |
| break |
| i += 1 |
| lines.insert(i, 'X-Peer: %s' % peer[0]) |
| data = NEWLINE.join(lines) |
| refused = self._deliver(mailfrom, rcpttos, data) |
| # TBD: what to do with refused addresses? |
| print('we got some refusals:', refused, file=DEBUGSTREAM) |
| |
| def _deliver(self, mailfrom, rcpttos, data): |
| import smtplib |
| refused = {} |
| try: |
| s = smtplib.SMTP() |
| s.connect(self._remoteaddr[0], self._remoteaddr[1]) |
| try: |
| refused = s.sendmail(mailfrom, rcpttos, data) |
| finally: |
| s.quit() |
| except smtplib.SMTPRecipientsRefused as e: |
| print('got SMTPRecipientsRefused', file=DEBUGSTREAM) |
| refused = e.recipients |
| except (OSError, smtplib.SMTPException) as e: |
| print('got', e.__class__, file=DEBUGSTREAM) |
| # All recipients were refused. If the exception had an associated |
| # error code, use it. Otherwise,fake it with a non-triggering |
| # exception code. |
| errcode = getattr(e, 'smtp_code', -1) |
| errmsg = getattr(e, 'smtp_error', 'ignore') |
| for r in rcpttos: |
| refused[r] = (errcode, errmsg) |
| return refused |
| |
| |
| class MailmanProxy(PureProxy): |
| def __init__(self, *args, **kwargs): |
| if 'enable_SMTPUTF8' in kwargs and kwargs['enable_SMTPUTF8']: |
| raise ValueError("MailmanProxy does not support SMTPUTF8.") |
| super(PureProxy, self).__init__(*args, **kwargs) |
| |
| def process_message(self, peer, mailfrom, rcpttos, data): |
| from io import StringIO |
| from Mailman import Utils |
| from Mailman import Message |
| from Mailman import MailList |
| # If the message is to a Mailman mailing list, then we'll invoke the |
| # Mailman script directly, without going through the real smtpd. |
| # Otherwise we'll forward it to the local proxy for disposition. |
| listnames = [] |
| for rcpt in rcpttos: |
| local = rcpt.lower().split('@')[0] |
| # We allow the following variations on the theme |
| # listname |
| # listname-admin |
| # listname-owner |
| # listname-request |
| # listname-join |
| # listname-leave |
| parts = local.split('-') |
| if len(parts) > 2: |
| continue |
| listname = parts[0] |
| if len(parts) == 2: |
| command = parts[1] |
| else: |
| command = '' |
| if not Utils.list_exists(listname) or command not in ( |
| '', 'admin', 'owner', 'request', 'join', 'leave'): |
| continue |
| listnames.append((rcpt, listname, command)) |
| # Remove all list recipients from rcpttos and forward what we're not |
| # going to take care of ourselves. Linear removal should be fine |
| # since we don't expect a large number of recipients. |
| for rcpt, listname, command in listnames: |
| rcpttos.remove(rcpt) |
| # If there's any non-list destined recipients left, |
| print('forwarding recips:', ' '.join(rcpttos), file=DEBUGSTREAM) |
| if rcpttos: |
| refused = self._deliver(mailfrom, rcpttos, data) |
| # TBD: what to do with refused addresses? |
| print('we got refusals:', refused, file=DEBUGSTREAM) |
| # Now deliver directly to the list commands |
| mlists = {} |
| s = StringIO(data) |
| msg = Message.Message(s) |
| # These headers are required for the proper execution of Mailman. All |
| # MTAs in existence seem to add these if the original message doesn't |
| # have them. |
| if not msg.get('from'): |
| msg['From'] = mailfrom |
| if not msg.get('date'): |
| msg['Date'] = time.ctime(time.time()) |
| for rcpt, listname, command in listnames: |
| print('sending message to', rcpt, file=DEBUGSTREAM) |
| mlist = mlists.get(listname) |
| if not mlist: |
| mlist = MailList.MailList(listname, lock=0) |
| mlists[listname] = mlist |
| # dispatch on the type of command |
| if command == '': |
| # post |
| msg.Enqueue(mlist, tolist=1) |
| elif command == 'admin': |
| msg.Enqueue(mlist, toadmin=1) |
| elif command == 'owner': |
| msg.Enqueue(mlist, toowner=1) |
| elif command == 'request': |
| msg.Enqueue(mlist, torequest=1) |
| elif command in ('join', 'leave'): |
| # TBD: this is a hack! |
| if command == 'join': |
| msg['Subject'] = 'subscribe' |
| else: |
| msg['Subject'] = 'unsubscribe' |
| msg.Enqueue(mlist, torequest=1) |
| |
| |
| class Options: |
| setuid = True |
| classname = 'PureProxy' |
| size_limit = None |
| enable_SMTPUTF8 = False |
| |
| |
| def parseargs(): |
| global DEBUGSTREAM |
| try: |
| opts, args = getopt.getopt( |
| sys.argv[1:], 'nVhc:s:du', |
| ['class=', 'nosetuid', 'version', 'help', 'size=', 'debug', |
| 'smtputf8']) |
| except getopt.error as e: |
| usage(1, e) |
| |
| options = Options() |
| for opt, arg in opts: |
| if opt in ('-h', '--help'): |
| usage(0) |
| elif opt in ('-V', '--version'): |
| print(__version__) |
| sys.exit(0) |
| elif opt in ('-n', '--nosetuid'): |
| options.setuid = False |
| elif opt in ('-c', '--class'): |
| options.classname = arg |
| elif opt in ('-d', '--debug'): |
| DEBUGSTREAM = sys.stderr |
| elif opt in ('-u', '--smtputf8'): |
| options.enable_SMTPUTF8 = True |
| elif opt in ('-s', '--size'): |
| try: |
| int_size = int(arg) |
| options.size_limit = int_size |
| except: |
| print('Invalid size: ' + arg, file=sys.stderr) |
| sys.exit(1) |
| |
| # parse the rest of the arguments |
| if len(args) < 1: |
| localspec = 'localhost:8025' |
| remotespec = 'localhost:25' |
| elif len(args) < 2: |
| localspec = args[0] |
| remotespec = 'localhost:25' |
| elif len(args) < 3: |
| localspec = args[0] |
| remotespec = args[1] |
| else: |
| usage(1, 'Invalid arguments: %s' % COMMASPACE.join(args)) |
| |
| # split into host/port pairs |
| i = localspec.find(':') |
| if i < 0: |
| usage(1, 'Bad local spec: %s' % localspec) |
| options.localhost = localspec[:i] |
| try: |
| options.localport = int(localspec[i+1:]) |
| except ValueError: |
| usage(1, 'Bad local port: %s' % localspec) |
| i = remotespec.find(':') |
| if i < 0: |
| usage(1, 'Bad remote spec: %s' % remotespec) |
| options.remotehost = remotespec[:i] |
| try: |
| options.remoteport = int(remotespec[i+1:]) |
| except ValueError: |
| usage(1, 'Bad remote port: %s' % remotespec) |
| return options |
| |
| |
| if __name__ == '__main__': |
| options = parseargs() |
| # Become nobody |
| classname = options.classname |
| if "." in classname: |
| lastdot = classname.rfind(".") |
| mod = __import__(classname[:lastdot], globals(), locals(), [""]) |
| classname = classname[lastdot+1:] |
| else: |
| import __main__ as mod |
| class_ = getattr(mod, classname) |
| proxy = class_((options.localhost, options.localport), |
| (options.remotehost, options.remoteport), |
| options.size_limit, enable_SMTPUTF8=options.enable_SMTPUTF8) |
| if options.setuid: |
| try: |
| import pwd |
| except ImportError: |
| print('Cannot import module "pwd"; try running with -n option.', file=sys.stderr) |
| sys.exit(1) |
| nobody = pwd.getpwnam('nobody')[2] |
| try: |
| os.setuid(nobody) |
| except PermissionError: |
| print('Cannot setuid "nobody"; try running with -n option.', file=sys.stderr) |
| sys.exit(1) |
| try: |
| asyncore.loop() |
| except KeyboardInterrupt: |
| pass |
