diff options
Diffstat (limited to 'Lib/smtpd.py')
| -rwxr-xr-x | Lib/smtpd.py | 324 |
1 files changed, 238 insertions, 86 deletions
diff --git a/Lib/smtpd.py b/Lib/smtpd.py index b4d208b2eeb..8cd405c5f6c 100755 --- a/Lib/smtpd.py +++ b/Lib/smtpd.py @@ -1,4 +1,4 @@ -#! /usr/bin/env python +#! /usr/bin/env python3 """An RFC 2821 smtp proxy. Usage: %(program)s [options] [localhost:localport [remotehost:remoteport]] @@ -35,6 +35,7 @@ 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 821. It @@ -58,7 +59,6 @@ and if remoteport is not given, then 25 is used. # gets forwarded to a real backend smtpd, as with PureProxy. Again, errors # are not handled correctly yet. # -# Please note that this script requires Python 2.0 # # Author: Barry Warsaw <barry@python.org> # @@ -77,6 +77,7 @@ import time import socket import asyncore import asynchat +from warnings import warn __all__ = ["SMTPServer","DebuggingServer","PureProxy","MailmanProxy"] @@ -95,56 +96,198 @@ EMPTYSTRING = '' COMMASPACE = ', ' + def usage(code, msg=''): - print >> sys.stderr, __doc__ % globals() + print(__doc__ % globals(), file=sys.stderr) if msg: - print >> sys.stderr, msg + print(msg, file=sys.stderr) sys.exit(code) + class SMTPChannel(asynchat.async_chat): COMMAND = 0 DATA = 1 + data_size_limit = 33554432 + command_size_limit = 512 + def __init__(self, server, conn, addr): asynchat.async_chat.__init__(self, conn) - self.__server = server - self.__conn = conn - self.__addr = addr - self.__line = [] - self.__state = self.COMMAND - self.__greeting = 0 - self.__mailfrom = None - self.__rcpttos = [] - self.__data = '' - self.__fqdn = socket.getfqdn() + self.smtp_server = server + self.conn = conn + self.addr = addr + self.received_lines = [] + self.smtp_state = self.COMMAND + self.seen_greeting = '' + self.mailfrom = None + self.rcpttos = [] + self.received_data = '' + self.fqdn = socket.getfqdn() + self.num_bytes = 0 try: - self.__peer = conn.getpeername() - except socket.error, err: + self.peer = conn.getpeername() + except socket.error as err: # a race condition may occur if the other end is closing # before we can get the peername self.close() - if err[0] != errno.ENOTCONN: + if err.args[0] != errno.ENOTCONN: raise return - print >> DEBUGSTREAM, 'Peer:', repr(self.__peer) - self.push('220 %s %s' % (self.__fqdn, __version__)) - self.set_terminator('\r\n') + print('Peer:', repr(self.peer), file=DEBUGSTREAM) + self.push('220 %s %s' % (self.fqdn, __version__)) + self.set_terminator(b'\r\n') + + # properties for backwards-compatibility + @property + def __server(self): + warn("Access to __server attribute on SMTPChannel is deprecated, " + "use 'smtp_server' instead", PendingDeprecationWarning, 2) + return self.smtp_server + @__server.setter + def __server(self, value): + warn("Setting __server attribute on SMTPChannel is deprecated, " + "set 'smtp_server' instead", PendingDeprecationWarning, 2) + self.smtp_server = value + + @property + def __line(self): + warn("Access to __line attribute on SMTPChannel is deprecated, " + "use 'received_lines' instead", PendingDeprecationWarning, 2) + return self.received_lines + @__line.setter + def __line(self, value): + warn("Setting __line attribute on SMTPChannel is deprecated, " + "set 'received_lines' instead", PendingDeprecationWarning, 2) + self.received_lines = value + + @property + def __state(self): + warn("Access to __state attribute on SMTPChannel is deprecated, " + "use 'smtp_state' instead", PendingDeprecationWarning, 2) + return self.smtp_state + @__state.setter + def __state(self, value): + warn("Setting __state attribute on SMTPChannel is deprecated, " + "set 'smtp_state' instead", PendingDeprecationWarning, 2) + self.smtp_state = value + + @property + def __greeting(self): + warn("Access to __greeting attribute on SMTPChannel is deprecated, " + "use 'seen_greeting' instead", PendingDeprecationWarning, 2) + return self.seen_greeting + @__greeting.setter + def __greeting(self, value): + warn("Setting __greeting attribute on SMTPChannel is deprecated, " + "set 'seen_greeting' instead", PendingDeprecationWarning, 2) + self.seen_greeting = value + + @property + def __mailfrom(self): + warn("Access to __mailfrom attribute on SMTPChannel is deprecated, " + "use 'mailfrom' instead", PendingDeprecationWarning, 2) + return self.mailfrom + @__mailfrom.setter + def __mailfrom(self, value): + warn("Setting __mailfrom attribute on SMTPChannel is deprecated, " + "set 'mailfrom' instead", PendingDeprecationWarning, 2) + self.mailfrom = value + + @property + def __rcpttos(self): + warn("Access to __rcpttos attribute on SMTPChannel is deprecated, " + "use 'rcpttos' instead", PendingDeprecationWarning, 2) + return self.rcpttos + @__rcpttos.setter + def __rcpttos(self, value): + warn("Setting __rcpttos attribute on SMTPChannel is deprecated, " + "set 'rcpttos' instead", PendingDeprecationWarning, 2) + self.rcpttos = value + + @property + def __data(self): + warn("Access to __data attribute on SMTPChannel is deprecated, " + "use 'received_data' instead", PendingDeprecationWarning, 2) + return self.received_data + @__data.setter + def __data(self, value): + warn("Setting __data attribute on SMTPChannel is deprecated, " + "set 'received_data' instead", PendingDeprecationWarning, 2) + self.received_data = value + + @property + def __fqdn(self): + warn("Access to __fqdn attribute on SMTPChannel is deprecated, " + "use 'fqdn' instead", PendingDeprecationWarning, 2) + return self.fqdn + @__fqdn.setter + def __fqdn(self, value): + warn("Setting __fqdn attribute on SMTPChannel is deprecated, " + "set 'fqdn' instead", PendingDeprecationWarning, 2) + self.fqdn = value + + @property + def __peer(self): + warn("Access to __peer attribute on SMTPChannel is deprecated, " + "use 'peer' instead", PendingDeprecationWarning, 2) + return self.peer + @__peer.setter + def __peer(self, value): + warn("Setting __peer attribute on SMTPChannel is deprecated, " + "set 'peer' instead", PendingDeprecationWarning, 2) + self.peer = value + + @property + def __conn(self): + warn("Access to __conn attribute on SMTPChannel is deprecated, " + "use 'conn' instead", PendingDeprecationWarning, 2) + return self.conn + @__conn.setter + def __conn(self, value): + warn("Setting __conn attribute on SMTPChannel is deprecated, " + "set 'conn' instead", PendingDeprecationWarning, 2) + self.conn = value + + @property + def __addr(self): + warn("Access to __addr attribute on SMTPChannel is deprecated, " + "use 'addr' instead", PendingDeprecationWarning, 2) + return self.addr + @__addr.setter + def __addr(self, value): + warn("Setting __addr attribute on SMTPChannel is deprecated, " + "set 'addr' instead", PendingDeprecationWarning, 2) + self.addr = value # Overrides base class for convenience def push(self, msg): - asynchat.async_chat.push(self, msg + '\r\n') + asynchat.async_chat.push(self, bytes(msg + '\r\n', 'ascii')) # Implementation of base class abstract method def collect_incoming_data(self, data): - self.__line.append(data) + limit = None + if self.smtp_state == self.COMMAND: + limit = self.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) + self.received_lines.append(str(data, "utf8")) # Implementation of base class abstract method def found_terminator(self): - line = EMPTYSTRING.join(self.__line) - print >> DEBUGSTREAM, 'Data:', repr(line) - self.__line = [] - if self.__state == self.COMMAND: + line = EMPTYSTRING.join(self.received_lines) + print('Data:', repr(line), file=DEBUGSTREAM) + self.received_lines = [] + if self.smtp_state == self.COMMAND: + if self.num_bytes > self.command_size_limit: + self.push('500 Error: line too long') + self.num_bytes = 0 + return + self.num_bytes = 0 if not line: self.push('500 Error: bad syntax') return @@ -163,8 +306,13 @@ class SMTPChannel(asynchat.async_chat): method(arg) return else: - if self.__state != self.DATA: + if self.smtp_state != self.DATA: self.push('451 Internal confusion') + self.num_bytes = 0 + return + if 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 821, Section 4.5.2. @@ -174,15 +322,16 @@ class SMTPChannel(asynchat.async_chat): data.append(text[1:]) else: data.append(text) - self.__data = NEWLINE.join(data) - status = self.__server.process_message(self.__peer, - self.__mailfrom, - self.__rcpttos, - self.__data) - self.__rcpttos = [] - self.__mailfrom = None - self.__state = self.COMMAND - self.set_terminator('\r\n') + self.received_data = NEWLINE.join(data) + status = self.smtp_server.process_message(self.peer, + self.mailfrom, + self.rcpttos, + self.received_data) + self.rcpttos = [] + self.mailfrom = None + self.smtp_state = self.COMMAND + self.num_bytes = 0 + self.set_terminator(b'\r\n') if not status: self.push('250 Ok') else: @@ -193,11 +342,11 @@ class SMTPChannel(asynchat.async_chat): if not arg: self.push('501 Syntax: HELO hostname') return - if self.__greeting: + if self.seen_greeting: self.push('503 Duplicate HELO/EHLO') else: - self.__greeting = arg - self.push('250 %s' % self.__fqdn) + self.seen_greeting = arg + self.push('250 %s' % self.fqdn) def smtp_NOOP(self, arg): if arg: @@ -225,29 +374,29 @@ class SMTPChannel(asynchat.async_chat): return address def smtp_MAIL(self, arg): - print >> DEBUGSTREAM, '===> MAIL', arg + print('===> MAIL', arg, file=DEBUGSTREAM) address = self.__getaddr('FROM:', arg) if arg else None if not address: self.push('501 Syntax: MAIL FROM:<address>') return - if self.__mailfrom: + if self.mailfrom: self.push('503 Error: nested MAIL command') return - self.__mailfrom = address - print >> DEBUGSTREAM, 'sender:', self.__mailfrom + self.mailfrom = address + print('sender:', self.mailfrom, file=DEBUGSTREAM) self.push('250 Ok') def smtp_RCPT(self, arg): - print >> DEBUGSTREAM, '===> RCPT', arg - if not self.__mailfrom: + print('===> RCPT', arg, file=DEBUGSTREAM) + if not self.mailfrom: self.push('503 Error: need MAIL command') return address = self.__getaddr('TO:', arg) if arg else None if not address: self.push('501 Syntax: RCPT TO: <address>') return - self.__rcpttos.append(address) - print >> DEBUGSTREAM, 'recips:', self.__rcpttos + self.rcpttos.append(address) + print('recips:', self.rcpttos, file=DEBUGSTREAM) self.push('250 Ok') def smtp_RSET(self, arg): @@ -255,25 +404,29 @@ class SMTPChannel(asynchat.async_chat): self.push('501 Syntax: RSET') return # Resets the sender, recipients, and data, but not the greeting - self.__mailfrom = None - self.__rcpttos = [] - self.__data = '' - self.__state = self.COMMAND + self.mailfrom = None + self.rcpttos = [] + self.received_data = '' + self.smtp_state = self.COMMAND self.push('250 Ok') def smtp_DATA(self, arg): - if not self.__rcpttos: + if not self.rcpttos: self.push('503 Error: need RCPT command') return if arg: self.push('501 Syntax: DATA') return - self.__state = self.DATA - self.set_terminator('\r\n.\r\n') + self.smtp_state = self.DATA + self.set_terminator(b'\r\n.\r\n') self.push('354 End data with <CR><LF>.<CR><LF>') + class SMTPServer(asyncore.dispatcher): + # SMTPChannel class to use for managing client connections + channel_class = SMTPChannel + def __init__(self, localaddr, remoteaddr): self._localaddr = localaddr self._remoteaddr = remoteaddr @@ -285,21 +438,16 @@ class SMTPServer(asyncore.dispatcher): self.bind(localaddr) self.listen(5) except: - # cleanup asyncore.socket_map before raising self.close() raise else: - print >> DEBUGSTREAM, \ - '%s started at %s\n\tLocal addr: %s\n\tRemote addr:%s' % ( + print('%s started at %s\n\tLocal addr: %s\n\tRemote addr:%s' % ( self.__class__.__name__, time.ctime(time.time()), - localaddr, remoteaddr) + localaddr, remoteaddr), file=DEBUGSTREAM) - def handle_accept(self): - pair = self.accept() - if pair is not None: - conn, addr = pair - print >> DEBUGSTREAM, 'Incoming connection from %s' % repr(addr) - channel = SMTPChannel(self, conn, addr) + def handle_accepted(self, conn, addr): + print('Incoming connection from %s' % repr(addr), file=DEBUGSTREAM) + channel = self.channel_class(self, conn, addr) # API for "doing something useful with the message" def process_message(self, peer, mailfrom, rcpttos, data): @@ -327,21 +475,23 @@ class SMTPServer(asyncore.dispatcher): raise NotImplementedError + class DebuggingServer(SMTPServer): # Do something with the gathered message def process_message(self, peer, mailfrom, rcpttos, data): inheaders = 1 lines = data.split('\n') - print '---------- MESSAGE FOLLOWS ----------' + print('---------- MESSAGE FOLLOWS ----------') for line in lines: # headers first if inheaders and not line: - print 'X-Peer:', peer[0] + print('X-Peer:', peer[0]) inheaders = 0 - print line - print '------------ END MESSAGE ------------' + print(line) + print('------------ END MESSAGE ------------') + class PureProxy(SMTPServer): def process_message(self, peer, mailfrom, rcpttos, data): lines = data.split('\n') @@ -355,7 +505,7 @@ class PureProxy(SMTPServer): data = NEWLINE.join(lines) refused = self._deliver(mailfrom, rcpttos, data) # TBD: what to do with refused addresses? - print >> DEBUGSTREAM, 'we got some refusals:', refused + print('we got some refusals:', refused, file=DEBUGSTREAM) def _deliver(self, mailfrom, rcpttos, data): import smtplib @@ -367,11 +517,11 @@ class PureProxy(SMTPServer): refused = s.sendmail(mailfrom, rcpttos, data) finally: s.quit() - except smtplib.SMTPRecipientsRefused, e: - print >> DEBUGSTREAM, 'got SMTPRecipientsRefused' + except smtplib.SMTPRecipientsRefused as e: + print('got SMTPRecipientsRefused', file=DEBUGSTREAM) refused = e.recipients - except (socket.error, smtplib.SMTPException), e: - print >> DEBUGSTREAM, 'got', e.__class__ + except (socket.error, 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. @@ -382,9 +532,10 @@ class PureProxy(SMTPServer): return refused + class MailmanProxy(PureProxy): def process_message(self, peer, mailfrom, rcpttos, data): - from cStringIO import StringIO + from io import StringIO from Mailman import Utils from Mailman import Message from Mailman import MailList @@ -419,11 +570,11 @@ class MailmanProxy(PureProxy): for rcpt, listname, command in listnames: rcpttos.remove(rcpt) # If there's any non-list destined recipients left, - print >> DEBUGSTREAM, 'forwarding recips:', ' '.join(rcpttos) + print('forwarding recips:', ' '.join(rcpttos), file=DEBUGSTREAM) if rcpttos: refused = self._deliver(mailfrom, rcpttos, data) # TBD: what to do with refused addresses? - print >> DEBUGSTREAM, 'we got refusals:', refused + print('we got refusals:', refused, file=DEBUGSTREAM) # Now deliver directly to the list commands mlists = {} s = StringIO(data) @@ -431,12 +582,12 @@ class MailmanProxy(PureProxy): # 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.getheader('from'): + if not msg.get('from'): msg['From'] = mailfrom - if not msg.getheader('date'): + if not msg.get('date'): msg['Date'] = time.ctime(time.time()) for rcpt, listname, command in listnames: - print >> DEBUGSTREAM, 'sending message to', rcpt + print('sending message to', rcpt, file=DEBUGSTREAM) mlist = mlists.get(listname) if not mlist: mlist = MailList.MailList(listname, lock=0) @@ -460,18 +611,20 @@ class MailmanProxy(PureProxy): msg.Enqueue(mlist, torequest=1) + class Options: setuid = 1 classname = 'PureProxy' + def parseargs(): global DEBUGSTREAM try: opts, args = getopt.getopt( sys.argv[1:], 'nVhc:d', ['class=', 'nosetuid', 'version', 'help', 'debug']) - except getopt.error, e: + except getopt.error as e: usage(1, e) options = Options() @@ -479,7 +632,7 @@ def parseargs(): if opt in ('-h', '--help'): usage(0) elif opt in ('-V', '--version'): - print >> sys.stderr, __version__ + print(__version__, file=sys.stderr) sys.exit(0) elif opt in ('-n', '--nosetuid'): options.setuid = 0 @@ -521,6 +674,7 @@ def parseargs(): return options + if __name__ == '__main__': options = parseargs() # Become nobody @@ -538,16 +692,14 @@ if __name__ == '__main__': try: import pwd except ImportError: - print >> sys.stderr, \ - 'Cannot import module "pwd"; try running with -n option.' + 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 OSError, e: + except OSError as e: if e.errno != errno.EPERM: raise - print >> sys.stderr, \ - 'Cannot setuid "nobody"; try running with -n option.' + print('Cannot setuid "nobody"; try running with -n option.', file=sys.stderr) sys.exit(1) try: asyncore.loop() |