From: Jeremy Stanley Date: Tue, 4 May 2010 03:01:14 +0000 (+0000) Subject: Proper RFC 1143 Telnet option negotiation queue. X-Git-Tag: 0.0.1~310 X-Git-Url: https://mudpy.org/gitweb?a=commitdiff_plain;h=0fca7fa3d5ac08111c8850555813d341d699797f;p=mudpy.git Proper RFC 1143 Telnet option negotiation queue. * lib/mudpy/__init__.py: Added telnet to the modules list. * lib/mudpy/misc.py (Element.send, User.__init__) (User.adjust_echoing, User.enqueue_input, User.flush) (User.replace_old_connections, User.send, check_for_connection) (get_echo_sequence, handle_user_input): Minor adjustments to accomodate new code in telnet.py. (User.negotiate_telnet_options, telnet_proto): Moved to telnet.py and reworked option negotiation stack to eliminate a possible loop, bringing the code fully in compliance with the "Q" method described in IETF RFC 1143. * lib/mudpy/telnet.py: New file for constants and functions related to support of the Telnet protocol. --- diff --git a/lib/mudpy/__init__.py b/lib/mudpy/__init__.py index 0676090..d462528 100644 --- a/lib/mudpy/__init__.py +++ b/lib/mudpy/__init__.py @@ -21,5 +21,5 @@ def load(): except NameError: exec(u"import %s" % module) # load the modules contained in this package -modules = [ u"misc" ] +modules = [ u"misc", u"telnet" ] load() diff --git a/lib/mudpy/misc.py b/lib/mudpy/misc.py index 3464744..3b11a12 100644 --- a/lib/mudpy/misc.py +++ b/lib/mudpy/misc.py @@ -185,11 +185,22 @@ class Element: raw=False, flush=False, add_prompt=True, - just_prompt=False + just_prompt=False, + add_terminator=False, + prepend_padding=True ): u"""Convenience method to pass messages to an owner.""" if self.owner: - self.owner.send(message, eol, raw, flush, add_prompt, just_prompt) + self.owner.send( + message, + eol, + raw, + flush, + add_prompt, + just_prompt, + add_terminator, + prepend_padding + ) def can_run(self, command): u"""Check if the user can run this command object.""" @@ -642,15 +653,13 @@ class User: def __init__(self): u"""Default values for the in-memory user variables.""" + import telnet self.account = None self.address = u"" self.authenticated = False self.avatar = None - self.client_displays_binary = False - self.client_sends_binary = False self.columns = 79 self.connection = None - self.echoing = True self.error = u"" self.input_queue = [] self.last_address = u"" @@ -661,9 +670,8 @@ class User: self.output_queue = [] self.partial_input = "" self.password_tries = 0 - self.received_newline = True self.state = u"initial" - self.terminator = telnet_proto([u"IAC",u"GA"]) + self.telopts = {} def quit(self): u"""Log, close the connection and remove.""" @@ -776,14 +784,6 @@ class User: old_user.connection = self.connection old_user.last_address = old_user.address old_user.address = self.address - old_user.client_displays_binary = self.client_displays_binary - old_user.client_sends_binary = self.client_sends_binary - - # may need to tell the new connection to echo - if old_user.echoing: - old_user.send( - get_echo_sequence(old_user.state, self.echoing), raw=True - ) # take this one out of the list and delete self.remove() @@ -823,8 +823,12 @@ class User: def adjust_echoing(self): u"""Adjust echoing to match state menu requirements.""" - if self.echoing and not menu_echo_on(self.state): self.echoing = False - elif not self.echoing and menu_echo_on(self.state): self.echoing = True + import telnet + if telnet.is_enabled(self, telnet.TELOPT_ECHO, telnet.US): + if menu_echo_on(self.state): + telnet.disable(self, telnet.TELOPT_ECHO, telnet.US) + elif not menu_echo_on(self.state): + telnet.enable(self, telnet.TELOPT_ECHO, telnet.US) def remove(self): u"""Remove a user from the list of connected users.""" @@ -838,9 +842,11 @@ class User: flush=False, add_prompt=True, just_prompt=False, - add_terminator=False + add_terminator=False, + prepend_padding=True ): u"""Send arbitrary text to a connected user.""" + import telnet # unless raw mode is on, clean it up all nice and pretty if not raw: @@ -856,11 +862,10 @@ class User: # start with a newline, append the message, then end # with the optional eol string passed to this function # and the ansi escape to return to normal text - if not just_prompt: - if not self.output_queue or not self.output_queue[-1].endswith( - "\r\n" - ): - output = u"$(eol)$(eol)" + output + if not just_prompt and prepend_padding: + if not self.output_queue \ + or not self.output_queue[-1].endswith("\r\n"): + output = u"$(eol)" + output elif not self.output_queue[-1].endswith( "\r\n\x1b[0m\r\n" ) and not self.output_queue[-1].endswith( @@ -887,18 +892,18 @@ class User: output = wrap_ansi_text(output, wrap) # if supported by the client, encode it utf-8 - if self.client_displays_binary: + if telnet.is_enabled(self, telnet.TELOPT_BINARY, telnet.US): encoded_output = output.encode(u"utf-8") # otherwise just send ascii - else: - encoded_output = output.encode(u"ascii", u"replace") - - # inject appropriate echoing changes - encoded_output += get_echo_sequence(self.state, self.echoing) + else: encoded_output = output.encode(u"ascii", u"replace") # end with a terminator if requested - if add_terminator: encoded_output += self.terminator + if add_prompt or add_terminator: + if telnet.is_enabled(self, telnet.TELOPT_EOR, telnet.US): + encoded_output += telnet.telnet_proto(telnet.IAC, telnet.EOR) + elif not telnet.is_enabled(self, telnet.TELOPT_SGA, telnet.US): + encoded_output += telnet.telnet_proto(telnet.IAC, telnet.GA) # and tack it onto the queue self.output_queue.append(encoded_output) @@ -946,10 +951,6 @@ class User: def flush(self): u"""Try to send the last item in the queue and remove it.""" if self.output_queue: - if self.received_newline: - self.received_newline = False - if self.output_queue[0].startswith("\r\n"): - self.output_queue[0] = self.output_queue[0][2:] try: self.connection.send(self.output_queue[0]) del self.output_queue[0] @@ -966,7 +967,7 @@ class User: def enqueue_input(self): u"""Process and enqueue any new input.""" - import unicodedata + import telnet, unicodedata # check for some input try: @@ -981,7 +982,7 @@ class User: self.partial_input += raw_input # reply to and remove any IAC negotiation codes - self.negotiate_telnet_options() + telnet.negotiate_telnet_options(self) # separate multiple input lines new_input_lines = self.partial_input.split("\n") @@ -1015,9 +1016,7 @@ class User: line = "" # log non-printable characters remaining - if not hasattr( - self, u"client_sends_binary" - ) or not self.client_sends_binary: + if telnet.is_enabled(self, telnet.TELOPT_BINARY, telnet.HIM): asciiline = filter(lambda x: " " <= x <= "~", line) if line != asciiline: logline = u"Non-ASCII characters from " @@ -1033,147 +1032,6 @@ class User: unicodedata.normalize( u"NFKC", unicode(line, u"utf-8") ) ) - def negotiate_telnet_options(self): - u"""Reply to/remove partial_input telnet negotiation options.""" - - # start at the begining of the input - position = 0 - - # make a local copy to play with - text = self.partial_input - - # as long as we haven't checked it all - while position < len(text): - - # jump to the first IAC you find - position = text.find(telnet_proto([u"IAC"]), position) - - # if there wasn't an IAC in the input, we're done - if position < 0: break - - # replace a double (literal) IAC if there's an LF later - elif len(text) > position+1 and text[position+1] == telnet_proto( - [u"IAC"] - ): - if text.find("\n", position) > 0: - text = text.replace( - telnet_proto([u"IAC",u"IAC"]), telnet_proto([u"IAC"]) - ) - else: position += 1 - position += 1 - - # implement an RFC 1143 option negotiation queue here - elif len(text) > position+2 and text[position+1] in ( - telnet_proto([u"DO",u"DONT",u"WILL",u"WONT"]) - ): - negotiation = text[position+1:position+3] - - # if we turned echo off, ignore the confirmation - if not self.echoing and negotiation == telnet_proto( - [u"DO",u"TELOPT_ECHO"] - ): - self.send( - telnet_proto([u"IAC",u"WILL",u"TELOPT_ECHO"]), raw=True - ) - - # BINARY mode handling for unicode support (RFC 856) - elif negotiation == telnet_proto([u"DO",u"TELOPT_BINARY"]): - self.send( - telnet_proto([u"IAC",u"WILL",u"TELOPT_BINARY"]), raw=True - ) - self.client_displays_binary = True - elif negotiation == telnet_proto([u"DONT",u"TELOPT_BINARY"]): - self.send( - telnet_proto([u"IAC",u"WONT",u"TELOPT_BINARY"]), raw=True - ) - self.client_displays_binary = False - elif negotiation == telnet_proto([u"WILL",u"TELOPT_BINARY"]): - self.send( - telnet_proto([u"IAC",u"DO",u"TELOPT_BINARY"]), raw=True - ) - self.client_sends_binary = True - elif negotiation == telnet_proto([u"WONT",u"TELOPT_BINARY"]): - self.send( - telnet_proto([u"IAC",u"DONT",u"TELOPT_BINARY"]), raw=True - ) - self.client_sends_binary = False - - # allow LINEMODE (RFC 1184) - elif negotiation == telnet_proto([u"WILL",u"TELOPT_LINEMODE"]): - self.send( - telnet_proto([u"IAC",u"DO",u"TELOPT_LINEMODE"]), raw=True - ) - elif negotiation == telnet_proto([u"WONT",u"TELOPT_LINEMODE"]): - self.send( - telnet_proto([u"IAC",u"DONT",u"TELOPT_LINEMODE"]), raw=True - ) - - # allow NAWS (RFC 1073) - elif negotiation == telnet_proto([u"WILL",u"TELOPT_NAWS"]): - self.send( - telnet_proto([u"IAC",u"DO",u"TELOPT_NAWS"]), raw=True - ) - elif negotiation == telnet_proto([u"WONT",u"TELOPT_NAWS"]): - self.send( - telnet_proto([u"IAC",u"DONT",u"TELOPT_NAWS"]), raw=True - ) - - # if the client likes EOR (RFC 885) instead of GA, note it - elif negotiation == telnet_proto([u"DO",u"TELOPT_EOR"]): - self.send( - telnet_proto([u"IAC",u"WILL",u"TELOPT_EOR"]), raw=True - ) - self.terminator = telnet_proto([u"IAC",u"EOR"]) - elif negotiation == telnet_proto([u"DONT",u"TELOPT_EOR"]): - self.send( - telnet_proto([u"IAC",u"WONT",u"TELOPT_EOR"]), raw=True - ) - if self.terminator == telnet_proto([u"IAC",u"EOR"]): - self.terminator = telnet_proto([u"IAC",u"GA"]) - - # if the client doesn't want GA, oblige (RFC 858) - elif negotiation == telnet_proto([u"DO",u"TELOPT_SGA"]): - self.send(telnet_proto([u"IAC",u"WILL",u"TELOPT_SGA"]), - raw=True) - if self.terminator == telnet_proto([u"IAC",u"GA"]): - self.terminator = "" - - # we don't want to allow anything else - elif text[position+1] == telnet_proto([u"DO"]): - self.send( - telnet_proto([u"IAC",u"WONT"])+text[position+2], raw=True - ) - elif text[position+1] == telnet_proto([u"WILL"]): - self.send( - telnet_proto([u"IAC",u"DONT"])+text[position+2], raw=True - ) - - # strip the negotiation from the input - text = text.replace(text[position:position+3], "") - - # subnegotiation options - elif len(text) > position+4 and text[ - position:position+2 - ] == telnet_proto([u"IAC",u"SB"]): - if text[position+2] == telnet_proto([u"TELOPT_NAWS"]): - self.columns = ord(text[position+3])*256+ord(text[position+4]) - end_subnegotiation = text.find( - telnet_proto([u"IAC",u"SE"]), position - ) - if end_subnegotiation > 0: - text = text[:position] + text[end_subnegotiation+2:] - else: position += 1 - - # otherwise, strip out a two-byte IAC command - elif len(text) > position+2: - text = text.replace(text[position:position+2], "") - - # and this means we got the begining of an IAC - else: position += 1 - - # replace the input with our cleaned-up text - self.partial_input = text - def new_avatar(self): u"""Instantiate a new, unconfigured avatar for this user.""" counter = 0 @@ -1247,34 +1105,6 @@ def makedict(value): elif value.find(u":") > 0: return eval(u"{" + value + u"}") else: return { value: None } -def telnet_proto(arguments): - u"""Return a concatenated series of Telnet protocol commands.""" - - # same names as bsd's arpa/telnet.h (telnetlib's are ambiguous) - telnet_commands = { - u"TELOPT_BINARY": 0, # RFC 856 - u"TELOPT_ECHO": 1, # RFC 857 - u"TELOPT_SGA": 3, # RFC 858 - u"TELOPT_EOR": 25, # RFC 885 - u"TELOPT_NAWS": 31, # RFC 1073 - u"TELOPT_LINEMODE": 34, # RFC 1184 - u"EOR": 239, - u"SE": 240, - u"GA": 249, - u"SB": 250, - u"WILL": 251, - u"WONT": 252, - u"DO": 253, - u"DONT": 254, - u"IAC": 255 - } - - # (this will need to be byte type during 2to3 migration) - command_series = "" - for argument in arguments: - command_series += chr(telnet_commands[argument]) - return command_series - def broadcast(message, add_prompt=True): u"""Send a message to all connected users.""" for each_user in universe.userlist: @@ -1699,6 +1529,7 @@ def reload_data(): def check_for_connection(listening_socket): u"""Check for a waiting connection and return a new user object.""" + import telnet # try to accept a new connection try: @@ -1722,7 +1553,7 @@ def check_for_connection(listening_socket): user.address = address[0] # let the client know we WILL EOR (RFC 885) - user.send(telnet_proto([u"IAC",u"WILL",u"TELOPT_EOR"]), raw=True) + telnet.enable(user, telnet.TELOPT_EOR, telnet.US) user.negotiation_pause = 2 # return the new user object @@ -1756,22 +1587,6 @@ def menu_echo_on(state): u"""True if echo is on, false if it is off.""" return universe.categories[u"menu"][state].getboolean(u"echo", True) -def get_echo_sequence(state, echoing): - u"""Build the appropriate IAC WILL/WONT ECHO sequence as needed.""" - - # if the user has echo on and the menu specifies it should be turned - # off, send: iac + will + echo + null - if echoing and not menu_echo_on(state): - return telnet_proto([u"IAC",u"WILL",u"TELOPT_ECHO"]) - - # if echo is not set to off in the menu and the user curently has echo - # off, send: iac + wont + echo + null - elif not echoing and menu_echo_on(state): - return telnet_proto([u"IAC",u"WONT",u"TELOPT_ECHO"]) - - # default is not to send an echo control sequence at all - else: return "" - def get_echo_message(state): u"""Return a message indicating that echo is off.""" if menu_echo_on(state): return u"" @@ -1899,9 +1714,11 @@ def get_choice_action(user, choice): def handle_user_input(user): u"""The main handler, branches to a state-specific handler.""" + import telnet # if the user's client echo is off, send a blank line for aesthetics - if user.echoing: user.received_newline = True + if telnet.is_enabled(user, telnet.TELOPT_ECHO, telnet.US): + user.send(u"", add_prompt=False, prepend_padding=False) # check to make sure the state is expected, then call that handler if u"handler_" + user.state in globals(): diff --git a/lib/mudpy/telnet.py b/lib/mudpy/telnet.py new file mode 100644 index 0000000..293d997 --- /dev/null +++ b/lib/mudpy/telnet.py @@ -0,0 +1,185 @@ +# -*- coding: utf-8 -*- +u"""Telnet functions and constants for the mudpy engine.""" + +# Copyright (c) 2004-2010 Jeremy Stanley . Permission +# to use, copy, modify, and distribute this software is granted under +# terms provided in the LICENSE file distributed with this software. + +# telnet options (from bsd's arpa/telnet.h since telnetlib's are ambiguous) +TELOPT_BINARY = 0 # transmit 8-bit data by the receiver (rfc 856) +TELOPT_ECHO = 1 # echo received data back to the sender (rfc 857) +TELOPT_SGA = 3 # suppress transmission of the go ahead character (rfc 858) +#TELOPT_TTYPE = 24 # exchange terminal type information (rfc 1091) +TELOPT_EOR = 25 # transmit end-of-record after transmitting data (rfc 885) +TELOPT_NAWS = 31 # negotiate about window size (rfc 1073) +TELOPT_LINEMODE = 34 # cooked line-by-line input mode (rfc 1184) + +supported = ( + TELOPT_BINARY, + TELOPT_ECHO, + TELOPT_SGA, + TELOPT_EOR, + TELOPT_NAWS, + TELOPT_LINEMODE +) + +# telnet commands +EOR = 239 # end-of-record signal (rfc 885) +SE = 240 # end of subnegotiation parameters (rfc 854) +GA = 249 # go ahead signal (rfc 854) +SB = 250 # what follows is subnegotiation of the indicated option (rfc 854) +WILL = 251 # desire or confirmation of performing an option (rfc 854) +WONT = 252 # refusal or confirmation of performing an option (rfc 854) +DO = 253 # request or confirm performing an option (rfc 854) +DONT = 254 # demand or confirm no longer performing an option (rfc 854) +IAC = 255 # interpret as command escape character (rfc 854) + +# RFC 1143 option negotiation states +NO = 0 # option is disabled +YES = 1 # option is enabled +WANTNO = 2 # demanded disabling option +WANTYES = 3 # requested enabling option +WANTNO_OPPOSITE = 4 # demanded disabling option but queued an enable after it +WANTYES_OPPOSITE = 5 # requested enabling option but queued a disable after it + +# RFC 1143 option negotiation parties +HIM = 0 +US = 1 + +def telnet_proto(*arguments): + u"""Return a concatenated series of Telnet protocol commands.""" + # (this will need to be byte type during 2to3 migration) + return "".join( [chr(x) for x in arguments] ) + +def send_command(user, *command): + u"""Sends a Telnet command string to the specified user's socket.""" + user.send( telnet_proto(IAC, *command), raw=True ) + +def is_enabled(user, telopt, party, state=YES): + u"""Returns True if the indicated Telnet option is enabled, False if not.""" + if (telopt, party) in user.telopts and user.telopts[ + (telopt, party) + ] is state: return True + else: return False + +def enable(user, telopt, party): + u"""Negotiates enabling a Telnet option for the indicated user's socket.""" + if party is HIM: txpos = DO + else: txpos = WILL + if not (telopt, party) in user.telopts or user.telopts[ + (telopt, party) + ] is NO: + user.telopts[ (telopt, party) ] = WANTYES + send_command(user, txpos, telopt) + elif user.telopts[ (telopt, party) ] is WANTNO: + user.telopts[ (telopt, party) ] = WANTNO_OPPOSITE + elif user.telopts[ (telopt, party) ] is WANTYES_OPPOSITE: + user.telopts[ (telopt, party) ] = WANTYES + +def disable(user, telopt, party): + u"""Negotiates disabling a Telnet option for the indicated user's socket.""" + if party is HIM: txneg = DONT + else: txneg = WONT + if not (telopt, party) in user.telopts: user.telopts[ (telopt, party) ] = NO + elif user.telopts[ (telopt, party) ] is YES: + user.telopts[ (telopt, party) ] = WANTNO + send_command(user, txneg, telopt) + elif user.telopts[ (telopt, party) ] is WANTYES: + user.telopts[ (telopt, party) ] = WANTYES_OPPOSITE + elif user.telopts[ (telopt, party) ] is WANTNO_OPPOSITE: + user.telopts[ (telopt, party) ] = WANTNO + +def negotiate_telnet_options(user): + u"""Reply to and remove telnet negotiation options from partial_input.""" + import misc + + # make a local copy to play with + text = user.partial_input + + # start at the begining of the input + position = 0 + + # as long as we haven't checked it all + len_text = len(text) + while position < len_text: + + # jump to the first IAC you find + position = text.find( telnet_proto(IAC), position ) + + # if there wasn't an IAC in the input or it's at the end, we're done + if position < 0 or position >= len_text-1: break + + # the byte following the IAC is our command + # (this will need to be byte type during 2to3 migration) + command = ord( text[position+1] ) + + # replace a double (literal) IAC if there's an LF later + if command is IAC: + if text.find("\n", position) > 0: + position += 1 + text = text[:position] + text[position+1:] + else: position += 2 + + # implement an RFC 1143 option negotiation queue here + elif len_text > position+2 and WILL <= command <= DONT: + # this will need to be byte type during 2to3 migration + telopt = ord( text[position+2] ) + if telopt in supported: + if command <= WONT: + party = HIM + rxpos = WILL + txpos = DO + txneg = DONT + else: + party = US + rxpos = DO + txpos = WILL + txneg = WONT + if (telopt, party) not in user.telopts: + user.telopts[ (telopt, party) ] = NO + if command is rxpos: + if user.telopts[ (telopt, party) ] is NO: + user.telopts[ (telopt, party) ] = YES + send_command(user, txpos, telopt) + elif user.telopts[ (telopt, party) ] is WANTNO: + user.telopts[ (telopt, party) ] = NO + elif user.telopts[ (telopt, party) ] is WANTNO_OPPOSITE: + user.telopts[ (telopt, party) ] = YES + elif user.telopts[ (telopt, party) ] is WANTYES_OPPOSITE: + user.telopts[ (telopt, party) ] = WANTNO + send_command(user, txneg, telopt) + else: user.telopts[ (telopt, party) ] = YES + else: + if user.telopts[ (telopt, party) ] is YES: + user.telopts[ (telopt, party) ] = NO + send_command(user, txneg, telopt) + elif user.telopts[ (telopt, party) ] is WANTNO_OPPOSITE: + user.telopts[ (telopt, party) ] = WANTYES + send_command(user, txpos, telopt) + else: user.telopts[ (telopt, party) ] = NO + elif command is WILL: send_command(user, DONT, telopt ) + else: send_command(user, WONT, telopt) + text = text[:position] + text[position+3:] + + # subnegotiation options + elif len_text > position+4 and command is SB: + # this will need to be byte type during 2to3 migration + telopt = ord( text[position+2] ) + if telopt is TELOPT_NAWS: + # this will need to be byte type during 2to3 migration + user.columns = ord(text[position+3])*256+ord(text[position+4]) + end_subnegotiation = text.find( telnet_proto(IAC, SE), position ) + if end_subnegotiation > 0: + text = text[:position] + text[end_subnegotiation+2:] + else: position += 1 + + # otherwise, strip out a two-byte IAC command + elif len_text > position+2: + misc.log(u"Unknown Telnet IAC command %s ignored." % command) + text = text[:position] + text[position+2:] + + # and this means we got the begining of an IAC + else: position += 1 + + # replace the input with our cleaned-up text + user.partial_input = text