nyancat-server/telnetsrvlib.py

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Python
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2011-11-30 23:12:57 +00:00
#!/usr/bin/python
"""TELNET server class
Based on the telnet client in telnetlib.py
Presents a command line interface to the telnet client.
Various settings can affect the operation of the server:
authCallback = Reference to authentication function. If
there is none, no un/pw is requested. Should
raise an exception if authentication fails
Default: None
authNeedUser = Should a username be requested?
Default: False
authNeedPass = Should a password be requested?
Default: False
COMMANDS = Dictionary of supported commands
Key = command (Must be upper case)
Value = List of (function, help text)
Function.__doc__ should be long help
Function.aliases may be a list of alternative spellings
"""
#from telnetlib import IAC, WILL, WONT, DO, DONT, ECHO, SGA, Telnet
import threading
import SocketServer
import socket
import time
import sys
import traceback
import curses.ascii
import curses.has_key
import curses
import logging
import re
if not hasattr(socket, 'SHUT_RDWR'):
socket.SHUT_RDWR = 2
__all__ = ["TelnetHandler", "TelnetCLIHandler"]
IAC = chr(255) # "Interpret As Command"
DONT = chr(254)
DO = chr(253)
WONT = chr(252)
WILL = chr(251)
theNULL = chr(0)
SE = chr(240) # Subnegotiation End
NOP = chr(241) # No Operation
DM = chr(242) # Data Mark
BRK = chr(243) # Break
IP = chr(244) # Interrupt process
AO = chr(245) # Abort output
AYT = chr(246) # Are You There
EC = chr(247) # Erase Character
EL = chr(248) # Erase Line
GA = chr(249) # Go Ahead
SB = chr(250) # Subnegotiation Begin
BINARY = chr(0) # 8-bit data path
ECHO = chr(1) # echo
RCP = chr(2) # prepare to reconnect
SGA = chr(3) # suppress go ahead
NAMS = chr(4) # approximate message size
STATUS = chr(5) # give status
TM = chr(6) # timing mark
RCTE = chr(7) # remote controlled transmission and echo
NAOL = chr(8) # negotiate about output line width
NAOP = chr(9) # negotiate about output page size
NAOCRD = chr(10) # negotiate about CR disposition
NAOHTS = chr(11) # negotiate about horizontal tabstops
NAOHTD = chr(12) # negotiate about horizontal tab disposition
NAOFFD = chr(13) # negotiate about formfeed disposition
NAOVTS = chr(14) # negotiate about vertical tab stops
NAOVTD = chr(15) # negotiate about vertical tab disposition
NAOLFD = chr(16) # negotiate about output LF disposition
XASCII = chr(17) # extended ascii character set
LOGOUT = chr(18) # force logout
BM = chr(19) # byte macro
DET = chr(20) # data entry terminal
SUPDUP = chr(21) # supdup protocol
SUPDUPOUTPUT = chr(22) # supdup output
SNDLOC = chr(23) # send location
TTYPE = chr(24) # terminal type
EOR = chr(25) # end or record
TUID = chr(26) # TACACS user identification
OUTMRK = chr(27) # output marking
TTYLOC = chr(28) # terminal location number
VT3270REGIME = chr(29) # 3270 regime
X3PAD = chr(30) # X.3 PAD
NAWS = chr(31) # window size
TSPEED = chr(32) # terminal speed
LFLOW = chr(33) # remote flow control
LINEMODE = chr(34) # Linemode option
XDISPLOC = chr(35) # X Display Location
OLD_ENVIRON = chr(36) # Old - Environment variables
AUTHENTICATION = chr(37) # Authenticate
ENCRYPT = chr(38) # Encryption option
NEW_ENVIRON = chr(39) # New - Environment variables
# the following ones come from
# http://www.iana.org/assignments/telnet-options
# Unfortunately, that document does not assign identifiers
# to all of them, so we are making them up
TN3270E = chr(40) # TN3270E
XAUTH = chr(41) # XAUTH
CHARSET = chr(42) # CHARSET
RSP = chr(43) # Telnet Remote Serial Port
COM_PORT_OPTION = chr(44) # Com Port Control Option
SUPPRESS_LOCAL_ECHO = chr(45) # Telnet Suppress Local Echo
TLS = chr(46) # Telnet Start TLS
KERMIT = chr(47) # KERMIT
SEND_URL = chr(48) # SEND-URL
FORWARD_X = chr(49) # FORWARD_X
PRAGMA_LOGON = chr(138) # TELOPT PRAGMA LOGON
SSPI_LOGON = chr(139) # TELOPT SSPI LOGON
PRAGMA_HEARTBEAT = chr(140) # TELOPT PRAGMA HEARTBEAT
EXOPL = chr(255) # Extended-Options-List
NOOPT = chr(0)
#Codes used in SB SE data stream for terminal type negotiation
IS = chr(0)
SEND = chr(1)
CMDS = {
WILL: 'WILL',
WONT: 'WONT',
DO: 'DO',
DONT: 'DONT',
SE: 'Subnegotiation End',
NOP: 'No Operation',
DM: 'Data Mark',
BRK: 'Break',
IP: 'Interrupt process',
AO: 'Abort output',
AYT: 'Are You There',
EC: 'Erase Character',
EL: 'Erase Line',
GA: 'Go Ahead',
SB: 'Subnegotiation Begin',
BINARY: 'Binary',
ECHO: 'Echo',
RCP: 'Prepare to reconnect',
SGA: 'Suppress Go-Ahead',
NAMS: 'Approximate message size',
STATUS: 'Give status',
TM: 'Timing mark',
RCTE: 'Remote controlled transmission and echo',
NAOL: 'Negotiate about output line width',
NAOP: 'Negotiate about output page size',
NAOCRD: 'Negotiate about CR disposition',
NAOHTS: 'Negotiate about horizontal tabstops',
NAOHTD: 'Negotiate about horizontal tab disposition',
NAOFFD: 'Negotiate about formfeed disposition',
NAOVTS: 'Negotiate about vertical tab stops',
NAOVTD: 'Negotiate about vertical tab disposition',
NAOLFD: 'Negotiate about output LF disposition',
XASCII: 'Extended ascii character set',
LOGOUT: 'Force logout',
BM: 'Byte macro',
DET: 'Data entry terminal',
SUPDUP: 'Supdup protocol',
SUPDUPOUTPUT: 'Supdup output',
SNDLOC: 'Send location',
TTYPE: 'Terminal type',
EOR: 'End or record',
TUID: 'TACACS user identification',
OUTMRK: 'Output marking',
TTYLOC: 'Terminal location number',
VT3270REGIME: '3270 regime',
X3PAD: 'X.3 PAD',
NAWS: 'Window size',
TSPEED: 'Terminal speed',
LFLOW: 'Remote flow control',
LINEMODE: 'Linemode option',
XDISPLOC: 'X Display Location',
OLD_ENVIRON: 'Old - Environment variables',
AUTHENTICATION: 'Authenticate',
ENCRYPT: 'Encryption option',
NEW_ENVIRON: 'New - Environment variables',
}
class TelnetHandler(SocketServer.BaseRequestHandler):
"A telnet server based on the client in telnetlib"
# What I am prepared to do?
DOACK = {
ECHO: WILL,
SGA: WILL,
NEW_ENVIRON: WONT,
}
# What do I want the client to do?
WILLACK = {
ECHO: DONT,
SGA: DO,
NAWS: DONT,
TTYPE: DO,
LINEMODE: DONT,
NEW_ENVIRON: DO,
}
# Default terminal type - used if client doesn't tell us its termtype
TERM = "ansi"
# Keycode to name mapping - used to decide which keys to query
KEYS = { # Key escape sequences
curses.KEY_UP: 'Up', # Cursor up
curses.KEY_DOWN: 'Down', # Cursor down
curses.KEY_LEFT: 'Left', # Cursor left
curses.KEY_RIGHT: 'Right', # Cursor right
curses.KEY_DC: 'Delete', # Delete right
curses.KEY_BACKSPACE: 'Backspace', # Delete left
}
# Reverse mapping of KEYS - used for cooking key codes
ESCSEQ = {
}
# Terminal output escape sequences
CODES = {
'DEOL': '', # Delete to end of line
'DEL': '', # Delete and close up
'INS': '', # Insert space
'CSRLEFT': '', # Move cursor left 1 space
'CSRRIGHT': '', # Move cursor right 1 space
}
# What prompt to display
PROMPT = "Telnet Server> "
# The function to call to verify authentication data
authCallback = None
# Does authCallback want a username?
authNeedUser = False
# Does authCallback want a password?
authNeedPass = False
# --------------------------- Environment Setup ----------------------------
def __init__(self, request, client_address, server):
"""Constructor.
When called without arguments, create an unconnected instance.
With a hostname argument, it connects the instance; a port
number is optional.
"""
# Am I doing the echoing?
self.DOECHO = True
# What opts have I sent DO/DONT for and what did I send?
self.DOOPTS = {}
# What opts have I sent WILL/WONT for and what did I send?
self.WILLOPTS = {}
# What commands does this CLI support
self.COMMANDS = {}
self.sock = None # TCP socket
self.rawq = '' # Raw input string
self.cookedq = [] # This is the cooked input stream (list of charcodes)
self.sbdataq = '' # Sub-Neg string
self.eof = 0 # Has EOF been reached?
self.iacseq = '' # Buffer for IAC sequence.
self.sb = 0 # Flag for SB and SE sequence.
self.history = [] # Command history
self.IQUEUELOCK = threading.Lock()
self.OQUEUELOCK = threading.Lock()
self.RUNSHELL = True
# A little magic - Everything called cmdXXX is a command
for k in dir(self):
if k[:3] == 'cmd':
name = k[3:]
method = getattr(self, k)
self.COMMANDS[name] = method
for alias in getattr(method, "aliases", []):
self.COMMANDS[alias] = self.COMMANDS[name]
SocketServer.BaseRequestHandler.__init__(self, request, client_address, server)
def setterm(self, term):
"Set the curses structures for this terminal"
logging.debug("Setting termtype to %s" % (term, ))
curses.setupterm(term) # This will raise if the termtype is not supported
self.TERM = term
self.ESCSEQ = {}
for k in self.KEYS.keys():
str = curses.tigetstr(curses.has_key._capability_names[k])
if str:
self.ESCSEQ[str] = k
self.CODES['DEOL'] = curses.tigetstr('el')
self.CODES['DEL'] = curses.tigetstr('dch1')
self.CODES['INS'] = curses.tigetstr('ich1')
self.CODES['CSRLEFT'] = curses.tigetstr('cub1')
self.CODES['CSRRIGHT'] = curses.tigetstr('cuf1')
def setup(self):
"Connect incoming connection to a telnet session"
self.setterm(self.TERM)
self.sock = self.request._sock
for k in self.DOACK.keys():
self.sendcommand(self.DOACK[k], k)
for k in self.WILLACK.keys():
self.sendcommand(self.WILLACK[k], k)
self.thread_ic = threading.Thread(target=self.inputcooker)
self.thread_ic.setDaemon(True)
self.thread_ic.start()
# Sleep for 0.5 second to allow options negotiation
time.sleep(0.5)
def finish(self):
"End this session"
self.sock.shutdown(socket.SHUT_RDWR)
# ------------------------- Telnet Options Engine --------------------------
def options_handler(self, sock, cmd, opt):
"Negotiate options"
# if CMDS.has_key(cmd):
# cmdtxt = CMDS[cmd]
# else:
# cmdtxt = "cmd:%d" % ord(cmd)
# if cmd in [WILL, WONT, DO, DONT]:
# if CMDS.has_key(opt):
# opttxt = CMDS[opt]
# else:
# opttxt = "opt:%d" % ord(opt)
# else:
# opttxt = ""
# logging.debug("OPTION: %s %s" % (cmdtxt, opttxt, ))
if cmd == NOP:
self.sendcommand(NOP)
elif cmd == WILL or cmd == WONT:
if self.WILLACK.has_key(opt):
self.sendcommand(self.WILLACK[opt], opt)
else:
self.sendcommand(DONT, opt)
if cmd == WILL and opt == TTYPE:
self.writecooked(IAC + SB + TTYPE + SEND + IAC + SE)
elif cmd == DO or cmd == DONT:
if self.DOACK.has_key(opt):
self.sendcommand(self.DOACK[opt], opt)
else:
self.sendcommand(WONT, opt)
if opt == ECHO:
self.DOECHO = (cmd == DO)
elif cmd == SE:
subreq = self.read_sb_data()
if subreq[0] == TTYPE and subreq[1] == IS:
try:
self.setterm(subreq[2:])
except:
logging.debug("Terminal type not known")
elif cmd == SB:
pass
else:
logging.debug("Unhandled option: %s %s" % (cmdtxt, opttxt, ))
def sendcommand(self, cmd, opt=None):
"Send a telnet command (IAC)"
# if CMDS.has_key(cmd):
# cmdtxt = CMDS[cmd]
# else:
# cmdtxt = "cmd:%d" % ord(cmd)
# if opt == None:
# opttxt = ''
# else:
# if CMDS.has_key(opt):
# opttxt = CMDS[opt]
# else:
# opttxt = "opt:%d" % ord(opt)
if cmd in [DO, DONT]:
if not self.DOOPTS.has_key(opt):
self.DOOPTS[opt] = None
if (((cmd == DO) and (self.DOOPTS[opt] != True))
or ((cmd == DONT) and (self.DOOPTS[opt] != False))):
# logging.debug("Sending %s %s" % (cmdtxt, opttxt, ))
self.DOOPTS[opt] = (cmd == DO)
self.writecooked(IAC + cmd + opt)
# else:
# logging.debug("Not resending %s %s" % (cmdtxt, opttxt, ))
elif cmd in [WILL, WONT]:
if not self.WILLOPTS.has_key(opt):
self.WILLOPTS[opt] = ''
if (((cmd == WILL) and (self.WILLOPTS[opt] != True))
or ((cmd == WONT) and (self.WILLOPTS[opt] != False))):
# logging.debug("Sending %s %s" % (cmdtxt, opttxt, ))
self.WILLOPTS[opt] = (cmd == WILL)
self.writecooked(IAC + cmd + opt)
# else:
# logging.debug("Not resending %s %s" % (cmdtxt, opttxt, ))
else:
self.writecooked(IAC + cmd)
def read_sb_data(self):
"""Return any data available in the SB ... SE queue.
Return '' if no SB ... SE available. Should only be called
after seeing a SB or SE command. When a new SB command is
found, old unread SB data will be discarded. Don't block.
"""
buf = self.sbdataq
self.sbdataq = ''
return buf
# ---------------------------- Input Functions -----------------------------
def _readline_echo(self, char, echo):
"""Echo a recieved character, move cursor etc..."""
if echo == True or (echo == None and self.DOECHO == True):
self.write(char)
def readline(self, echo=None):
"""Return a line of text, including the terminating LF
If echo is true always echo, if echo is false never echo
If echo is None follow the negotiated setting.
"""
line = []
insptr = 0
histptr = len(self.history)
while True:
c = self.getc(block=True)
if c == theNULL:
continue
elif c == curses.KEY_LEFT:
if insptr > 0:
insptr = insptr - 1
self._readline_echo(self.CODES['CSRLEFT'], echo)
else:
self._readline_echo(chr(7), echo)
continue
elif c == curses.KEY_RIGHT:
if insptr < len(line):
insptr = insptr + 1
self._readline_echo(self.CODES['CSRRIGHT'], echo)
else:
self._readline_echo(chr(7), echo)
continue
elif c == curses.KEY_UP or c == curses.KEY_DOWN:
if c == curses.KEY_UP:
if histptr > 0:
histptr = histptr - 1
else:
self._readline_echo(chr(7), echo)
continue
elif c == curses.KEY_DOWN:
if histptr < len(self.history):
histptr = histptr + 1
else:
self._readline_echo(chr(7), echo)
continue
line = []
if histptr < len(self.history):
line.extend(self.history[histptr])
for char in range(insptr):
self._readline_echo(self.CODES['CSRLEFT'], echo)
self._readline_echo(self.CODES['DEOL'], echo)
self._readline_echo(''.join(line), echo)
insptr = len(line)
continue
elif c == chr(3):
self._readline_echo('\n' + curses.ascii.unctrl(c) + ' ABORT\n', echo)
return ''
elif c == chr(4):
if len(line) > 0:
self._readline_echo('\n' + curses.ascii.unctrl(c) + ' ABORT (QUIT)\n', echo)
return ''
self._readline_echo('\n' + curses.ascii.unctrl(c) + ' QUIT\n', echo)
return 'QUIT'
elif c == chr(10):
self._readline_echo(c, echo)
if echo == True or (echo == None and self.DOECHO == True):
self.history.append(line)
return ''.join(line)
elif c == curses.KEY_BACKSPACE or c == chr(127) or c == chr(8):
if insptr > 0:
self._readline_echo(self.CODES['CSRLEFT'] + self.CODES['DEL'], echo)
insptr = insptr - 1
del line[insptr]
else:
self._readline_echo(chr(7), echo)
continue
elif c == curses.KEY_DC:
if insptr < len(line):
self._readline_echo(self.CODES['DEL'], echo)
del line[insptr]
else:
self._readline_echo(chr(7), echo)
continue
else:
if ord(c) < 32:
c = curses.ascii.unctrl(c)
self._readline_echo(c, echo)
line[insptr:insptr] = c
insptr = insptr + len(c)
def getc(self, block=True):
"""Return one character from the input queue"""
if not block:
if not len(self.cookedq):
return ''
while not len(self.cookedq):
time.sleep(0.05)
self.IQUEUELOCK.acquire()
ret = self.cookedq[0]
self.cookedq = self.cookedq[1:]
self.IQUEUELOCK.release()
return ret
# --------------------------- Output Functions -----------------------------
def writeline(self, text):
"""Send a packet with line ending."""
self.write(text+chr(10))
def write(self, text):
"""Send a packet to the socket. This function cooks output."""
text = text.replace(IAC, IAC+IAC)
text = text.replace(chr(10), chr(13)+chr(10))
self.writecooked(text)
def writecooked(self, text):
"""Put data directly into the output queue (bypass output cooker)"""
self.OQUEUELOCK.acquire()
self.sock.sendall(text)
self.OQUEUELOCK.release()
# ------------------------------- Input Cooker -----------------------------
def _inputcooker_getc(self, block=True):
"""Get one character from the raw queue. Optionally blocking.
Raise EOFError on end of stream. SHOULD ONLY BE CALLED FROM THE
INPUT COOKER."""
if self.rawq:
ret = self.rawq[0]
self.rawq = self.rawq[1:]
return ret
if not block:
if select.select([self.sock.fileno()], [], [], 0) == ([], [], []):
return ''
ret = self.sock.recv(20)
self.eof = not(ret)
self.rawq = self.rawq + ret
if self.eof:
raise EOFError
return self._inputcooker_getc(block)
def _inputcooker_ungetc(self, char):
"""Put characters back onto the head of the rawq. SHOULD ONLY
BE CALLED FROM THE INPUT COOKER."""
self.rawq = char + self.rawq
def _inputcooker_store(self, char):
"""Put the cooked data in the correct queue (with locking)"""
if self.sb:
self.sbdataq = self.sbdataq + char
else:
self.IQUEUELOCK.acquire()
if type(char) in [type(()), type([]), type("")]:
for v in char:
self.cookedq.append(v)
else:
self.cookedq.append(char)
self.IQUEUELOCK.release()
def inputcooker(self):
"""Input Cooker - Transfer from raw queue to cooked queue.
Set self.eof when connection is closed. Don't block unless in
the midst of an IAC sequence.
"""
try:
while True:
c = self._inputcooker_getc()
if not self.iacseq:
if c == IAC:
self.iacseq += c
continue
elif c == chr(13) and not(self.sb):
c2 = self._inputcooker_getc(block=False)
if c2 == theNULL or c2 == '':
c = chr(10)
elif c2 == chr(10):
c = c2
else:
self._inputcooker_ungetc(c2)
c = chr(10)
elif c in [x[0] for x in self.ESCSEQ.keys()]:
'Looks like the begining of a key sequence'
codes = c
for keyseq in self.ESCSEQ.keys():
if len(keyseq) == 0:
continue
while codes == keyseq[:len(codes)] and len(codes) <= keyseq:
if codes == keyseq:
c = self.ESCSEQ[keyseq]
break
codes = codes + self._inputcooker_getc()
if codes == keyseq:
break
self._inputcooker_ungetc(codes[1:])
codes = codes[0]
self._inputcooker_store(c)
elif len(self.iacseq) == 1:
'IAC: IAC CMD [OPTION only for WILL/WONT/DO/DONT]'
if c in (DO, DONT, WILL, WONT):
self.iacseq += c
continue
self.iacseq = ''
if c == IAC:
self._inputcooker_store(c)
else:
if c == SB: # SB ... SE start.
self.sb = 1
self.sbdataq = ''
# continue
elif c == SE: # SB ... SE end.
self.sb = 0
# Callback is supposed to look into
# the sbdataq
self.options_handler(self.sock, c, NOOPT)
elif len(self.iacseq) == 2:
cmd = self.iacseq[1]
self.iacseq = ''
if cmd in (DO, DONT, WILL, WONT):
self.options_handler(self.sock, cmd, c)
except EOFError:
pass
# ------------------------------- Basic Commands ---------------------------
# Format of docstrings for command methods:
# Line 0: Command paramater(s) if any. (Can be blank line)
# Line 1: Short descriptive text. (Mandatory)
# Line 2+: Long descriptive text. (Can be blank line)
def cmdHELP(self, params):
"""[<command>]
Display help
Display either brief help on all commands, or detailed
help on a single command passed as a parameter.
"""
if params:
cmd = params[0].upper()
if self.COMMANDS.has_key(cmd):
method = self.COMMANDS[cmd]
doc = method.__doc__.split("\n")
docp = doc[0].strip()
docl = '\n'.join(doc[2:]).replace("\n\t\t", " ").replace("\t", "").strip()
if len(docl) < 4:
docl = doc[1].strip()
self.writeline(
"%s %s\n\n%s" % (
cmd,
docp,
docl,
)
)
return
else:
self.writeline("Command '%s' not known" % cmd)
else:
self.writeline("Help on built in commands\n")
keys = self.COMMANDS.keys()
keys.sort()
for cmd in keys:
method = self.COMMANDS[cmd]
doc = method.__doc__.split("\n")
docp = doc[0].strip()
docs = doc[1].strip()
if len(docp) > 0:
docps = "%s - %s" % (docp, docs, )
else:
docps = "- %s" % (docs, )
self.writeline(
"%s %s" % (
cmd,
docps,
)
)
cmdHELP.aliases = ['?']
def cmdEXIT(self, params):
"""
Exit the command shell
"""
self.RUNSHELL = False
self.writeline("Goodbye")
cmdEXIT.aliases = ['QUIT', 'BYE', 'LOGOUT']
def cmdDEBUG(self, params):
"""
Display some debugging data
"""
for (v,k) in self.ESCSEQ.items():
line = '%-10s : ' % (self.KEYS[k], )
for c in v:
if ord(c)<32 or ord(c)>126:
line = line + curses.ascii.unctrl(c)
else:
line = line + c
self.writeline(line)
def cmdHISTORY(self, params):
"""
Display the command history
"""
cnt = 0
self.writeline('Command history\n')
for line in self.history:
cnt = cnt + 1
self.writeline("%-5d : %s" % (cnt, ''.join(line)))
# ----------------------- Command Line Processor Engine --------------------
def handleException(self, exc_type, exc_param, exc_tb):
"Exception handler (False to abort)"
self.writeline(traceback.format_exception_only(exc_type, exc_param)[-1])
return True
def handle(self):
"The actual service to which the user has connected."
username = None
password = None
if self.authCallback:
if self.authNeedUser:
if self.DOECHO:
self.write("Username: ")
username = self.readline()
if self.authNeedPass:
if self.DOECHO:
self.write("Password: ")
password = self.readline(echo=False)
if self.DOECHO:
self.write("\n")
try:
self.authCallback(username, password)
except:
return
while self.RUNSHELL:
if self.DOECHO:
self.write(self.PROMPT)
cmdlist = [item.strip() for item in self.readline().split()]
idx = 0
while idx < (len(cmdlist) - 1):
if cmdlist[idx][0] in ["'", '"']:
cmdlist[idx] = cmdlist[idx] + " " + cmdlist.pop(idx+1)
if cmdlist[idx][0] != cmdlist[idx][-1]:
continue
cmdlist[idx] = cmdlist[idx][1:-1]
idx = idx + 1
if cmdlist:
cmd = cmdlist[0].upper()
params = cmdlist[1:]
if self.COMMANDS.has_key(cmd):
try:
self.COMMANDS[cmd](params)
except:
(t, p, tb) = sys.exc_info()
if self.handleException(t, p, tb):
break
else:
self.write("Unknown command '%s'\n" % cmd)
logging.debug("Exiting handler")
if __name__ == '__main__':
"Testing - Accept a single connection"
class TNS(SocketServer.TCPServer):
allow_reuse_address = True
class TNH(TelnetHandler):
def cmdECHO(self, params):
""" [<arg> ...]
Echo parameters
Echo command line parameters back to user, one per line.
"""
self.writeline("Parameters:")
for item in params:
self.writeline("\t%s" % item)
logging.getLogger('').setLevel(logging.DEBUG)
tns = TNS(("0.0.0.0", 23), TNH)
tns.serve_forever()
# vim: set syntax=python ai showmatch: