1 # -*- coding: utf-8 -*-
2 u"""Telnet functions and constants for the mudpy engine."""
4 # Copyright (c) 2004-2010 Jeremy Stanley <fungi@yuggoth.org>. Permission
5 # to use, copy, modify, and distribute this software is granted under
6 # terms provided in the LICENSE file distributed with this software.
8 # telnet options (from bsd's arpa/telnet.h since telnetlib's are ambiguous)
9 TELOPT_BINARY = 0 # transmit 8-bit data by the receiver (rfc 856)
10 TELOPT_ECHO = 1 # echo received data back to the sender (rfc 857)
11 TELOPT_SGA = 3 # suppress transmission of the go ahead character (rfc 858)
12 #TELOPT_TTYPE = 24 # exchange terminal type information (rfc 1091)
13 TELOPT_EOR = 25 # transmit end-of-record after transmitting data (rfc 885)
14 TELOPT_NAWS = 31 # negotiate about window size (rfc 1073)
15 TELOPT_LINEMODE = 34 # cooked line-by-line input mode (rfc 1184)
27 EOR = 239 # end-of-record signal (rfc 885)
28 SE = 240 # end of subnegotiation parameters (rfc 854)
29 GA = 249 # go ahead signal (rfc 854)
30 SB = 250 # what follows is subnegotiation of the indicated option (rfc 854)
31 WILL = 251 # desire or confirmation of performing an option (rfc 854)
32 WONT = 252 # refusal or confirmation of performing an option (rfc 854)
33 DO = 253 # request or confirm performing an option (rfc 854)
34 DONT = 254 # demand or confirm no longer performing an option (rfc 854)
35 IAC = 255 # interpret as command escape character (rfc 854)
37 # RFC 1143 option negotiation states
38 NO = 0 # option is disabled
39 YES = 1 # option is enabled
40 WANTNO = 2 # demanded disabling option
41 WANTYES = 3 # requested enabling option
42 WANTNO_OPPOSITE = 4 # demanded disabling option but queued an enable after it
43 WANTYES_OPPOSITE = 5 # requested enabling option but queued a disable after it
45 # RFC 1143 option negotiation parties
49 def telnet_proto(*arguments):
50 u"""Return a concatenated series of Telnet protocol commands."""
51 # (this will need to be byte type during 2to3 migration)
52 return "".join( [chr(x) for x in arguments] )
54 def send_command(user, *command):
55 u"""Sends a Telnet command string to the specified user's socket."""
56 user.send( telnet_proto(IAC, *command), raw=True )
58 def is_enabled(user, telopt, party, state=YES):
59 u"""Returns True if the indicated Telnet option is enabled, False if not."""
60 if (telopt, party) in user.telopts and user.telopts[
62 ] is state: return True
65 def enable(user, telopt, party):
66 u"""Negotiates enabling a Telnet option for the indicated user's socket."""
67 if party is HIM: txpos = DO
69 if not (telopt, party) in user.telopts or user.telopts[
72 user.telopts[ (telopt, party) ] = WANTYES
73 send_command(user, txpos, telopt)
74 elif user.telopts[ (telopt, party) ] is WANTNO:
75 user.telopts[ (telopt, party) ] = WANTNO_OPPOSITE
76 elif user.telopts[ (telopt, party) ] is WANTYES_OPPOSITE:
77 user.telopts[ (telopt, party) ] = WANTYES
79 def disable(user, telopt, party):
80 u"""Negotiates disabling a Telnet option for the indicated user's socket."""
81 if party is HIM: txneg = DONT
83 if not (telopt, party) in user.telopts: user.telopts[ (telopt, party) ] = NO
84 elif user.telopts[ (telopt, party) ] is YES:
85 user.telopts[ (telopt, party) ] = WANTNO
86 send_command(user, txneg, telopt)
87 elif user.telopts[ (telopt, party) ] is WANTYES:
88 user.telopts[ (telopt, party) ] = WANTYES_OPPOSITE
89 elif user.telopts[ (telopt, party) ] is WANTNO_OPPOSITE:
90 user.telopts[ (telopt, party) ] = WANTNO
92 def negotiate_telnet_options(user):
93 u"""Reply to and remove telnet negotiation options from partial_input."""
96 # make a local copy to play with
97 text = user.partial_input
99 # start at the begining of the input
102 # as long as we haven't checked it all
104 while position < len_text:
106 # jump to the first IAC you find
107 position = text.find( telnet_proto(IAC), position )
109 # if there wasn't an IAC in the input or it's at the end, we're done
110 if position < 0 or position >= len_text-1: break
112 # the byte following the IAC is our command
113 # (this will need to be byte type during 2to3 migration)
114 command = ord( text[position+1] )
116 # replace a double (literal) IAC if there's an LF later
118 if text.find("\n", position) > 0:
120 text = text[:position] + text[position+1:]
123 # implement an RFC 1143 option negotiation queue here
124 elif len_text > position+2 and WILL <= command <= DONT:
125 # this will need to be byte type during 2to3 migration
126 telopt = ord( text[position+2] )
127 if telopt in supported:
138 if (telopt, party) not in user.telopts:
139 user.telopts[ (telopt, party) ] = NO
141 if user.telopts[ (telopt, party) ] is NO:
142 user.telopts[ (telopt, party) ] = YES
143 send_command(user, txpos, telopt)
144 elif user.telopts[ (telopt, party) ] is WANTNO:
145 user.telopts[ (telopt, party) ] = NO
146 elif user.telopts[ (telopt, party) ] is WANTNO_OPPOSITE:
147 user.telopts[ (telopt, party) ] = YES
148 elif user.telopts[ (telopt, party) ] is WANTYES_OPPOSITE:
149 user.telopts[ (telopt, party) ] = WANTNO
150 send_command(user, txneg, telopt)
151 else: user.telopts[ (telopt, party) ] = YES
153 if user.telopts[ (telopt, party) ] is YES:
154 user.telopts[ (telopt, party) ] = NO
155 send_command(user, txneg, telopt)
156 elif user.telopts[ (telopt, party) ] is WANTNO_OPPOSITE:
157 user.telopts[ (telopt, party) ] = WANTYES
158 send_command(user, txpos, telopt)
159 else: user.telopts[ (telopt, party) ] = NO
160 elif command is WILL: send_command(user, DONT, telopt )
161 else: send_command(user, WONT, telopt)
162 text = text[:position] + text[position+3:]
164 # subnegotiation options
165 elif len_text > position+4 and command is SB:
166 # this will need to be byte type during 2to3 migration
167 telopt = ord( text[position+2] )
168 if telopt is TELOPT_NAWS:
169 # this will need to be byte type during 2to3 migration
170 user.columns = ord(text[position+3])*256+ord(text[position+4])
171 end_subnegotiation = text.find( telnet_proto(IAC, SE), position )
172 if end_subnegotiation > 0:
173 text = text[:position] + text[end_subnegotiation+2:]
176 # otherwise, strip out a two-byte IAC command
177 elif len_text > position+2:
178 misc.log(u"Unknown Telnet IAC command %s ignored." % command)
179 text = text[:position] + text[position+2:]
181 # and this means we got the begining of an IAC
184 # replace the input with our cleaned-up text
185 user.partial_input = text