1 r
"""TELNET client class.
3 Based on RFC 854: TELNET Protocol Specification, by J. Postel and
8 >>> from telnetlib import Telnet
9 >>> tn = Telnet('www.python.org', 79) # connect to finger port
10 >>> tn.write('guido\r\n')
11 >>> print tn.read_all()
12 Login Name TTY Idle When Where
13 guido Guido van Rossum pts/2 <Dec 2 11:10> snag.cnri.reston..
17 Note that read_all() won't read until eof -- it just reads some data
18 -- but it guarantees to read at least one byte unless EOF is hit.
20 It is possible to pass a Telnet object to select.select() in order to
21 wait until more data is available. Note that in this case,
22 read_eager() may return '' even if there was data on the socket,
23 because the protocol negotiation may have eaten the data. This is why
24 EOFError is needed in some cases to distinguish between "no data" and
25 "connection closed" (since the socket also appears ready for reading
30 - timeout should be intrinsic to the connection object instead of an
31 option on one of the read calls only
46 # Telnet protocol defaults
49 # Telnet protocol characters (don't change)
50 IAC
= chr(255) # "Interpret As Command"
57 SE
= chr(240) # Subnegotiation End
58 NOP
= chr(241) # No Operation
59 DM
= chr(242) # Data Mark
60 BRK
= chr(243) # Break
61 IP
= chr(244) # Interrupt process
62 AO
= chr(245) # Abort output
63 AYT
= chr(246) # Are You There
64 EC
= chr(247) # Erase Character
65 EL
= chr(248) # Erase Line
66 GA
= chr(249) # Go Ahead
67 SB
= chr(250) # Subnegotiation Begin
70 # Telnet protocol options code (don't change)
71 # These ones all come from arpa/telnet.h
72 BINARY
= chr(0) # 8-bit data path
74 RCP
= chr(2) # prepare to reconnect
75 SGA
= chr(3) # suppress go ahead
76 NAMS
= chr(4) # approximate message size
77 STATUS
= chr(5) # give status
78 TM
= chr(6) # timing mark
79 RCTE
= chr(7) # remote controlled transmission and echo
80 NAOL
= chr(8) # negotiate about output line width
81 NAOP
= chr(9) # negotiate about output page size
82 NAOCRD
= chr(10) # negotiate about CR disposition
83 NAOHTS
= chr(11) # negotiate about horizontal tabstops
84 NAOHTD
= chr(12) # negotiate about horizontal tab disposition
85 NAOFFD
= chr(13) # negotiate about formfeed disposition
86 NAOVTS
= chr(14) # negotiate about vertical tab stops
87 NAOVTD
= chr(15) # negotiate about vertical tab disposition
88 NAOLFD
= chr(16) # negotiate about output LF disposition
89 XASCII
= chr(17) # extended ascii character set
90 LOGOUT
= chr(18) # force logout
91 BM
= chr(19) # byte macro
92 DET
= chr(20) # data entry terminal
93 SUPDUP
= chr(21) # supdup protocol
94 SUPDUPOUTPUT
= chr(22) # supdup output
95 SNDLOC
= chr(23) # send location
96 TTYPE
= chr(24) # terminal type
97 EOR
= chr(25) # end or record
98 TUID
= chr(26) # TACACS user identification
99 OUTMRK
= chr(27) # output marking
100 TTYLOC
= chr(28) # terminal location number
101 VT3270REGIME
= chr(29) # 3270 regime
102 X3PAD
= chr(30) # X.3 PAD
103 NAWS
= chr(31) # window size
104 TSPEED
= chr(32) # terminal speed
105 LFLOW
= chr(33) # remote flow control
106 LINEMODE
= chr(34) # Linemode option
107 XDISPLOC
= chr(35) # X Display Location
108 OLD_ENVIRON
= chr(36) # Old - Environment variables
109 AUTHENTICATION
= chr(37) # Authenticate
110 ENCRYPT
= chr(38) # Encryption option
111 NEW_ENVIRON
= chr(39) # New - Environment variables
112 # the following ones come from
113 # http://www.iana.org/assignments/telnet-options
114 # Unfortunately, that document does not assign identifiers
115 # to all of them, so we are making them up
116 TN3270E
= chr(40) # TN3270E
117 XAUTH
= chr(41) # XAUTH
118 CHARSET
= chr(42) # CHARSET
119 RSP
= chr(43) # Telnet Remote Serial Port
120 COM_PORT_OPTION
= chr(44) # Com Port Control Option
121 SUPPRESS_LOCAL_ECHO
= chr(45) # Telnet Suppress Local Echo
122 TLS
= chr(46) # Telnet Start TLS
123 KERMIT
= chr(47) # KERMIT
124 SEND_URL
= chr(48) # SEND-URL
125 FORWARD_X
= chr(49) # FORWARD_X
126 PRAGMA_LOGON
= chr(138) # TELOPT PRAGMA LOGON
127 SSPI_LOGON
= chr(139) # TELOPT SSPI LOGON
128 PRAGMA_HEARTBEAT
= chr(140) # TELOPT PRAGMA HEARTBEAT
129 EXOPL
= chr(255) # Extended-Options-List
134 """Telnet interface class.
136 An instance of this class represents a connection to a telnet
137 server. The instance is initially not connected; the open()
138 method must be used to establish a connection. Alternatively, the
139 host name and optional port number can be passed to the
142 Don't try to reopen an already connected instance.
144 This class has many read_*() methods. Note that some of them
145 raise EOFError when the end of the connection is read, because
146 they can return an empty string for other reasons. See the
147 individual doc strings.
149 read_until(expected, [timeout])
150 Read until the expected string has been seen, or a timeout is
151 hit (default is no timeout); may block.
154 Read all data until EOF; may block.
157 Read at least one byte or EOF; may block.
160 Read all data available already queued or on the socket,
164 Read either data already queued or some data available on the
165 socket, without blocking.
168 Read all data in the raw queue (processing it first), without
169 doing any socket I/O.
172 Reads all data in the cooked queue, without doing any socket
176 Reads available data between SB ... SE sequence. Don't block.
178 set_option_negotiation_callback(callback)
179 Each time a telnet option is read on the input flow, this callback
180 (if set) is called with the following parameters :
181 callback(telnet socket, command, option)
182 option will be chr(0) when there is no option.
183 No other action is done afterwards by telnetlib.
187 def __init__(self
, host
=None, port
=0, timeout
=None):
190 When called without arguments, create an unconnected instance.
191 With a hostname argument, it connects the instance; a port
195 self
.debuglevel
= DEBUGLEVEL
198 self
.timeout
= timeout
204 self
.iacseq
= '' # Buffer for IAC sequence.
205 self
.sb
= 0 # flag for SB and SE sequence.
207 self
.option_callback
= None
209 self
.open(host
, port
, timeout
)
211 def open(self
, host
, port
=0, timeout
=None):
212 """Connect to a host.
214 The optional second argument is the port number, which
215 defaults to the standard telnet port (23).
217 Don't try to reopen an already connected instance.
225 if timeout
is not None:
226 self
.timeout
= timeout
227 self
.sock
= socket
.create_connection((host
, port
), self
.timeout
)
230 """Destructor -- close the connection."""
233 def msg(self
, msg
, *args
):
234 """Print a debug message, when the debug level is > 0.
236 If extra arguments are present, they are substituted in the
237 message using the standard string formatting operator.
240 if self
.debuglevel
> 0:
241 print 'Telnet(%s,%d):' % (self
.host
, self
.port
),
247 def set_debuglevel(self
, debuglevel
):
248 """Set the debug level.
250 The higher it is, the more debug output you get (on sys.stdout).
253 self
.debuglevel
= debuglevel
256 """Close the connection."""
264 def get_socket(self
):
265 """Return the socket object used internally."""
269 """Return the fileno() of the socket object used internally."""
270 return self
.sock
.fileno()
272 def write(self
, buffer):
273 """Write a string to the socket, doubling any IAC characters.
275 Can block if the connection is blocked. May raise
276 socket.error if the connection is closed.
280 buffer = buffer.replace(IAC
, IAC
+IAC
)
281 self
.msg("send %r", buffer)
282 self
.sock
.sendall(buffer)
284 def read_until(self
, match
, timeout
=None):
285 """Read until a given string is encountered or until timeout.
287 When no match is found, return whatever is available instead,
288 possibly the empty string. Raise EOFError if the connection
289 is closed and no cooked data is available.
294 i
= self
.cookedq
.find(match
)
297 buf
= self
.cookedq
[:i
]
298 self
.cookedq
= self
.cookedq
[i
:]
300 s_reply
= ([self
], [], [])
302 if timeout
is not None:
303 s_args
= s_args
+ (timeout
,)
304 from time
import time
306 while not self
.eof
and select
.select(*s_args
) == s_reply
:
307 i
= max(0, len(self
.cookedq
)-n
)
310 i
= self
.cookedq
.find(match
, i
)
313 buf
= self
.cookedq
[:i
]
314 self
.cookedq
= self
.cookedq
[i
:]
316 if timeout
is not None:
317 elapsed
= time() - time_start
318 if elapsed
>= timeout
:
320 s_args
= s_reply
+ (timeout
-elapsed
,)
321 return self
.read_very_lazy()
324 """Read all data until EOF; block until connection closed."""
334 """Read at least one byte of cooked data unless EOF is hit.
336 Return '' if EOF is hit. Block if no data is immediately
341 while not self
.cookedq
and not self
.eof
:
348 def read_very_eager(self
):
349 """Read everything that's possible without blocking in I/O (eager).
351 Raise EOFError if connection closed and no cooked data
352 available. Return '' if no cooked data available otherwise.
353 Don't block unless in the midst of an IAC sequence.
357 while not self
.eof
and self
.sock_avail():
360 return self
.read_very_lazy()
362 def read_eager(self
):
363 """Read readily available data.
365 Raise EOFError if connection closed and no cooked data
366 available. Return '' if no cooked data available otherwise.
367 Don't block unless in the midst of an IAC sequence.
371 while not self
.cookedq
and not self
.eof
and self
.sock_avail():
374 return self
.read_very_lazy()
377 """Process and return data that's already in the queues (lazy).
379 Raise EOFError if connection closed and no data available.
380 Return '' if no cooked data available otherwise. Don't block
381 unless in the midst of an IAC sequence.
385 return self
.read_very_lazy()
387 def read_very_lazy(self
):
388 """Return any data available in the cooked queue (very lazy).
390 Raise EOFError if connection closed and no data available.
391 Return '' if no cooked data available otherwise. Don't block.
396 if not buf
and self
.eof
and not self
.rawq
:
397 raise EOFError, 'telnet connection closed'
400 def read_sb_data(self
):
401 """Return any data available in the SB ... SE queue.
403 Return '' if no SB ... SE available. Should only be called
404 after seeing a SB or SE command. When a new SB command is
405 found, old unread SB data will be discarded. Don't block.
412 def set_option_negotiation_callback(self
, callback
):
413 """Provide a callback function called after each receipt of a telnet option."""
414 self
.option_callback
= callback
416 def process_rawq(self
):
417 """Transfer from raw queue to cooked queue.
419 Set self.eof when connection is closed. Don't block unless in
420 the midst of an IAC sequence.
426 c
= self
.rawq_getchar()
433 buf
[self
.sb
] = buf
[self
.sb
] + c
437 elif len(self
.iacseq
) == 1:
438 # 'IAC: IAC CMD [OPTION only for WILL/WONT/DO/DONT]'
439 if c
in (DO
, DONT
, WILL
, WONT
):
445 buf
[self
.sb
] = buf
[self
.sb
] + c
447 if c
== SB
: # SB ... SE start.
452 self
.sbdataq
= self
.sbdataq
+ buf
[1]
454 if self
.option_callback
:
455 # Callback is supposed to look into
457 self
.option_callback(self
.sock
, c
, NOOPT
)
459 # We can't offer automatic processing of
460 # suboptions. Alas, we should not get any
461 # unless we did a WILL/DO before.
462 self
.msg('IAC %d not recognized' % ord(c
))
463 elif len(self
.iacseq
) == 2:
467 if cmd
in (DO
, DONT
):
468 self
.msg('IAC %s %d',
469 cmd
== DO
and 'DO' or 'DONT', ord(opt
))
470 if self
.option_callback
:
471 self
.option_callback(self
.sock
, cmd
, opt
)
473 self
.sock
.sendall(IAC
+ WONT
+ opt
)
474 elif cmd
in (WILL
, WONT
):
475 self
.msg('IAC %s %d',
476 cmd
== WILL
and 'WILL' or 'WONT', ord(opt
))
477 if self
.option_callback
:
478 self
.option_callback(self
.sock
, cmd
, opt
)
480 self
.sock
.sendall(IAC
+ DONT
+ opt
)
481 except EOFError: # raised by self.rawq_getchar()
482 self
.iacseq
= '' # Reset on EOF
485 self
.cookedq
= self
.cookedq
+ buf
[0]
486 self
.sbdataq
= self
.sbdataq
+ buf
[1]
488 def rawq_getchar(self
):
489 """Get next char from raw queue.
491 Block if no data is immediately available. Raise EOFError
492 when connection is closed.
499 c
= self
.rawq
[self
.irawq
]
500 self
.irawq
= self
.irawq
+ 1
501 if self
.irawq
>= len(self
.rawq
):
507 """Fill raw queue from exactly one recv() system call.
509 Block if no data is immediately available. Set self.eof when
510 connection is closed.
513 if self
.irawq
>= len(self
.rawq
):
516 # The buffer size should be fairly small so as to avoid quadratic
517 # behavior in process_rawq() above
518 buf
= self
.sock
.recv(50)
519 self
.msg("recv %r", buf
)
521 self
.rawq
= self
.rawq
+ buf
523 def sock_avail(self
):
524 """Test whether data is available on the socket."""
525 return select
.select([self
], [], [], 0) == ([self
], [], [])
528 """Interaction function, emulates a very dumb telnet client."""
529 if sys
.platform
== "win32":
533 rfd
, wfd
, xfd
= select
.select([self
, sys
.stdin
], [], [])
536 text
= self
.read_eager()
538 print '*** Connection closed by remote host ***'
541 sys
.stdout
.write(text
)
544 line
= sys
.stdin
.readline()
549 def mt_interact(self
):
550 """Multithreaded version of interact()."""
552 thread
.start_new_thread(self
.listener
, ())
554 line
= sys
.stdin
.readline()
560 """Helper for mt_interact() -- this executes in the other thread."""
563 data
= self
.read_eager()
565 print '*** Connection closed by remote host ***'
568 sys
.stdout
.write(data
)
572 def expect(self
, list, timeout
=None):
573 """Read until one from a list of a regular expressions matches.
575 The first argument is a list of regular expressions, either
576 compiled (re.RegexObject instances) or uncompiled (strings).
577 The optional second argument is a timeout, in seconds; default
580 Return a tuple of three items: the index in the list of the
581 first regular expression that matches; the match object
582 returned; and the text read up till and including the match.
584 If EOF is read and no text was read, raise EOFError.
585 Otherwise, when nothing matches, return (-1, None, text) where
586 text is the text received so far (may be the empty string if a
589 If a regular expression ends with a greedy match (e.g. '.*')
590 or if more than one expression can match the same input, the
591 results are undeterministic, and may depend on the I/O timing.
596 indices
= range(len(list))
598 if not hasattr(list[i
], "search"):
600 list[i
] = re
.compile(list[i
])
601 if timeout
is not None:
602 from time
import time
607 m
= list[i
].search(self
.cookedq
)
610 text
= self
.cookedq
[:e
]
611 self
.cookedq
= self
.cookedq
[e
:]
615 if timeout
is not None:
616 elapsed
= time() - time_start
617 if elapsed
>= timeout
:
619 s_args
= ([self
.fileno()], [], [], timeout
-elapsed
)
620 r
, w
, x
= select
.select(*s_args
)
624 text
= self
.read_very_lazy()
625 if not text
and self
.eof
:
627 return (-1, None, text
)
631 """Test program for telnetlib.
633 Usage: python telnetlib.py [-d] ... [host [port]]
635 Default host is localhost; default port is 23.
639 while sys
.argv
[1:] and sys
.argv
[1] == '-d':
640 debuglevel
= debuglevel
+1
647 portstr
= sys
.argv
[2]
651 port
= socket
.getservbyname(portstr
, 'tcp')
653 tn
.set_debuglevel(debuglevel
)
654 tn
.open(host
, port
, timeout
=0.5)
658 if __name__
== '__main__':