diff options
Diffstat (limited to 'Lib/smtpd.py')
| -rwxr-xr-x | Lib/smtpd.py | 244 |
1 files changed, 195 insertions, 49 deletions
diff --git a/Lib/smtpd.py b/Lib/smtpd.py index ab3e0e2..599e79b 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]] @@ -59,7 +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> # @@ -78,6 +77,7 @@ import time import socket import asyncore import asynchat +from warnings import warn __all__ = ["SMTPServer","DebuggingServer","PureProxy","MailmanProxy"] @@ -109,20 +109,24 @@ 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() + 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 @@ -130,24 +134,160 @@ class SMTPChannel(asynchat.async_chat): if err.args[0] != errno.ENOTCONN: raise return - print('Peer:', repr(self.__peer), file=DEBUGSTREAM) - self.push('220 %s %s' % (self.__fqdn, __version__)) + 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, bytes(msg + '\r\n', 'ascii')) # Implementation of base class abstract method def collect_incoming_data(self, data): - self.__line.append(str(data, "utf8")) + 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) + line = EMPTYSTRING.join(self.received_lines) print('Data:', repr(line), file=DEBUGSTREAM) - self.__line = [] - if self.__state == self.COMMAND: + 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 @@ -166,8 +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. @@ -177,14 +322,15 @@ 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.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') @@ -196,11 +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: @@ -233,24 +379,24 @@ class SMTPChannel(asynchat.async_chat): 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('sender:', self.__mailfrom, file=DEBUGSTREAM) + self.mailfrom = address + print('sender:', self.mailfrom, file=DEBUGSTREAM) self.push('250 Ok') def smtp_RCPT(self, arg): print('===> RCPT', arg, file=DEBUGSTREAM) - if not self.__mailfrom: + 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('recips:', self.__rcpttos, file=DEBUGSTREAM) + self.rcpttos.append(address) + print('recips:', self.rcpttos, file=DEBUGSTREAM) self.push('250 Ok') def smtp_RSET(self, arg): @@ -258,26 +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.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 @@ -296,12 +445,9 @@ class SMTPServer(asyncore.dispatcher): self.__class__.__name__, time.ctime(time.time()), localaddr, remoteaddr), file=DEBUGSTREAM) - def handle_accept(self): - pair = self.accept() - if pair is not None: - conn, addr = pair - print('Incoming connection from %s' % repr(addr), file=DEBUGSTREAM) - 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): |