382 lines
12 KiB
Python
382 lines
12 KiB
Python
|
#!/usr/bin/env python3
|
||
|
|
# -*- coding: utf-8 -*-
|
||
|
|
#
|
||
|
|
# Project ___| | | | _ \| |
|
||
|
|
# / __| | | | |_) | |
|
||
|
|
# | (__| |_| | _ <| |___
|
||
|
|
# \___|\___/|_| \_\_____|
|
||
|
|
#
|
||
|
|
# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
|
||
|
|
#
|
||
|
|
# This software is licensed as described in the file COPYING, which
|
||
|
|
# you should have received as part of this distribution. The terms
|
||
|
|
# are also available at https://curl.se/docs/copyright.html.
|
||
|
|
#
|
||
|
|
# You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
||
|
|
# copies of the Software, and permit persons to whom the Software is
|
||
|
|
# furnished to do so, under the terms of the COPYING file.
|
||
|
|
#
|
||
|
|
# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
||
|
|
# KIND, either express or implied.
|
||
|
|
#
|
||
|
|
# SPDX-License-Identifier: curl
|
||
|
|
#
|
||
|
|
""" A telnet server which negotiates"""
|
||
|
|
|
||
|
|
from __future__ import (absolute_import, division, print_function,
|
||
|
|
unicode_literals)
|
||
|
|
|
||
|
|
import argparse
|
||
|
|
import logging
|
||
|
|
import os
|
||
|
|
import socket
|
||
|
|
import sys
|
||
|
|
import time
|
||
|
|
|
||
|
|
from util import ClosingFileHandler
|
||
|
|
|
||
|
|
if sys.version_info.major >= 3:
|
||
|
|
import socketserver
|
||
|
|
else:
|
||
|
|
import SocketServer as socketserver
|
||
|
|
|
||
|
|
log = logging.getLogger(__name__)
|
||
|
|
HOST = "localhost"
|
||
|
|
IDENT = "NTEL"
|
||
|
|
|
||
|
|
|
||
|
|
# The strings that indicate the test framework is checking our aliveness
|
||
|
|
VERIFIED_REQ = "verifiedserver"
|
||
|
|
VERIFIED_RSP = "WE ROOLZ: {pid}"
|
||
|
|
|
||
|
|
|
||
|
|
def telnetserver(options):
|
||
|
|
"""
|
||
|
|
Starts up a TCP server with a telnet handler and serves DICT requests
|
||
|
|
forever.
|
||
|
|
"""
|
||
|
|
if options.pidfile:
|
||
|
|
pid = os.getpid()
|
||
|
|
# see tests/server/util.c function write_pidfile
|
||
|
|
if os.name == "nt":
|
||
|
|
pid += 65536
|
||
|
|
with open(options.pidfile, "w") as f:
|
||
|
|
f.write(str(pid))
|
||
|
|
|
||
|
|
local_bind = (HOST, options.port)
|
||
|
|
log.info("Listening on %s", local_bind)
|
||
|
|
|
||
|
|
# Need to set the allow_reuse on the class, not on the instance.
|
||
|
|
socketserver.TCPServer.allow_reuse_address = True
|
||
|
|
with socketserver.TCPServer(local_bind, NegotiatingTelnetHandler) as server:
|
||
|
|
server.serve_forever()
|
||
|
|
# leaving `with` calls server.close() automatically
|
||
|
|
return ScriptRC.SUCCESS
|
||
|
|
|
||
|
|
|
||
|
|
class NegotiatingTelnetHandler(socketserver.BaseRequestHandler):
|
||
|
|
"""Handler class for Telnet connections.
|
||
|
|
|
||
|
|
"""
|
||
|
|
def handle(self):
|
||
|
|
"""
|
||
|
|
Negotiates options before reading data.
|
||
|
|
"""
|
||
|
|
neg = Negotiator(self.request)
|
||
|
|
|
||
|
|
try:
|
||
|
|
# Send some initial negotiations.
|
||
|
|
neg.send_do("NEW_ENVIRON")
|
||
|
|
neg.send_will("NEW_ENVIRON")
|
||
|
|
neg.send_dont("NAWS")
|
||
|
|
neg.send_wont("NAWS")
|
||
|
|
|
||
|
|
# Get the data passed through the negotiator
|
||
|
|
data = neg.recv(4*1024)
|
||
|
|
log.debug("Incoming data: %r", data)
|
||
|
|
|
||
|
|
if VERIFIED_REQ.encode('utf-8') in data:
|
||
|
|
log.debug("Received verification request from test framework")
|
||
|
|
pid = os.getpid()
|
||
|
|
# see tests/server/util.c function write_pidfile
|
||
|
|
if os.name == "nt":
|
||
|
|
pid += 65536
|
||
|
|
response = VERIFIED_RSP.format(pid=pid)
|
||
|
|
response_data = response.encode('utf-8')
|
||
|
|
else:
|
||
|
|
log.debug("Received normal request - echoing back")
|
||
|
|
response_data = data.decode('utf-8').strip().encode('utf-8')
|
||
|
|
|
||
|
|
if response_data:
|
||
|
|
log.debug("Sending %r", response_data)
|
||
|
|
self.request.sendall(response_data)
|
||
|
|
|
||
|
|
# put some effort into making a clean socket shutdown
|
||
|
|
# that does not give the client ECONNRESET
|
||
|
|
self.request.settimeout(0.1)
|
||
|
|
self.request.recv(4*1024)
|
||
|
|
self.request.shutdown(socket.SHUT_RDWR)
|
||
|
|
|
||
|
|
except IOError:
|
||
|
|
log.exception("IOError hit during request")
|
||
|
|
|
||
|
|
|
||
|
|
class Negotiator(object):
|
||
|
|
NO_NEG = 0
|
||
|
|
START_NEG = 1
|
||
|
|
WILL = 2
|
||
|
|
WONT = 3
|
||
|
|
DO = 4
|
||
|
|
DONT = 5
|
||
|
|
|
||
|
|
def __init__(self, tcp):
|
||
|
|
self.tcp = tcp
|
||
|
|
self.state = self.NO_NEG
|
||
|
|
|
||
|
|
def recv(self, bytes):
|
||
|
|
"""
|
||
|
|
Read bytes from TCP, handling negotiation sequences
|
||
|
|
|
||
|
|
:param bytes: Number of bytes to read
|
||
|
|
:return: a buffer of bytes
|
||
|
|
"""
|
||
|
|
buffer = bytearray()
|
||
|
|
|
||
|
|
# If we keep receiving negotiation sequences, we won't fill the buffer.
|
||
|
|
# Keep looping while we can, and until we have something to give back
|
||
|
|
# to the caller.
|
||
|
|
while len(buffer) == 0:
|
||
|
|
data = self.tcp.recv(bytes)
|
||
|
|
if not data:
|
||
|
|
# TCP failed to give us any data. Break out.
|
||
|
|
break
|
||
|
|
|
||
|
|
for byte_int in bytearray(data):
|
||
|
|
if self.state == self.NO_NEG:
|
||
|
|
self.no_neg(byte_int, buffer)
|
||
|
|
elif self.state == self.START_NEG:
|
||
|
|
self.start_neg(byte_int)
|
||
|
|
elif self.state in [self.WILL, self.WONT, self.DO, self.DONT]:
|
||
|
|
self.handle_option(byte_int)
|
||
|
|
else:
|
||
|
|
# Received an unexpected byte. Stop negotiations
|
||
|
|
log.error("Unexpected byte %s in state %s",
|
||
|
|
byte_int,
|
||
|
|
self.state)
|
||
|
|
self.state = self.NO_NEG
|
||
|
|
|
||
|
|
return buffer
|
||
|
|
|
||
|
|
def no_neg(self, byte_int, buffer):
|
||
|
|
# Not negotiating anything thus far. Check to see if we
|
||
|
|
# should.
|
||
|
|
if byte_int == NegTokens.IAC:
|
||
|
|
# Start negotiation
|
||
|
|
log.debug("Starting negotiation (IAC)")
|
||
|
|
self.state = self.START_NEG
|
||
|
|
else:
|
||
|
|
# Just append the incoming byte to the buffer
|
||
|
|
buffer.append(byte_int)
|
||
|
|
|
||
|
|
def start_neg(self, byte_int):
|
||
|
|
# In a negotiation.
|
||
|
|
log.debug("In negotiation (%s)",
|
||
|
|
NegTokens.from_val(byte_int))
|
||
|
|
|
||
|
|
if byte_int == NegTokens.WILL:
|
||
|
|
# Client is confirming they are willing to do an option
|
||
|
|
log.debug("Client is willing")
|
||
|
|
self.state = self.WILL
|
||
|
|
elif byte_int == NegTokens.WONT:
|
||
|
|
# Client is confirming they are unwilling to do an
|
||
|
|
# option
|
||
|
|
log.debug("Client is unwilling")
|
||
|
|
self.state = self.WONT
|
||
|
|
elif byte_int == NegTokens.DO:
|
||
|
|
# Client is indicating they can do an option
|
||
|
|
log.debug("Client can do")
|
||
|
|
self.state = self.DO
|
||
|
|
elif byte_int == NegTokens.DONT:
|
||
|
|
# Client is indicating they can't do an option
|
||
|
|
log.debug("Client can't do")
|
||
|
|
self.state = self.DONT
|
||
|
|
else:
|
||
|
|
# Received an unexpected byte. Stop negotiations
|
||
|
|
log.error("Unexpected byte %s in state %s",
|
||
|
|
byte_int,
|
||
|
|
self.state)
|
||
|
|
self.state = self.NO_NEG
|
||
|
|
|
||
|
|
def handle_option(self, byte_int):
|
||
|
|
if byte_int in [NegOptions.BINARY,
|
||
|
|
NegOptions.CHARSET,
|
||
|
|
NegOptions.SUPPRESS_GO_AHEAD,
|
||
|
|
NegOptions.NAWS,
|
||
|
|
NegOptions.NEW_ENVIRON]:
|
||
|
|
log.debug("Option: %s", NegOptions.from_val(byte_int))
|
||
|
|
|
||
|
|
# No further negotiation of this option needed. Reset the state.
|
||
|
|
self.state = self.NO_NEG
|
||
|
|
|
||
|
|
else:
|
||
|
|
# Received an unexpected byte. Stop negotiations
|
||
|
|
log.error("Unexpected byte %s in state %s",
|
||
|
|
byte_int,
|
||
|
|
self.state)
|
||
|
|
self.state = self.NO_NEG
|
||
|
|
|
||
|
|
def send_message(self, message_ints):
|
||
|
|
self.tcp.sendall(bytearray(message_ints))
|
||
|
|
|
||
|
|
def send_iac(self, arr):
|
||
|
|
message = [NegTokens.IAC]
|
||
|
|
message.extend(arr)
|
||
|
|
self.send_message(message)
|
||
|
|
|
||
|
|
def send_do(self, option_str):
|
||
|
|
log.debug("Sending DO %s", option_str)
|
||
|
|
self.send_iac([NegTokens.DO, NegOptions.to_val(option_str)])
|
||
|
|
|
||
|
|
def send_dont(self, option_str):
|
||
|
|
log.debug("Sending DONT %s", option_str)
|
||
|
|
self.send_iac([NegTokens.DONT, NegOptions.to_val(option_str)])
|
||
|
|
|
||
|
|
def send_will(self, option_str):
|
||
|
|
log.debug("Sending WILL %s", option_str)
|
||
|
|
self.send_iac([NegTokens.WILL, NegOptions.to_val(option_str)])
|
||
|
|
|
||
|
|
def send_wont(self, option_str):
|
||
|
|
log.debug("Sending WONT %s", option_str)
|
||
|
|
self.send_iac([NegTokens.WONT, NegOptions.to_val(option_str)])
|
||
|
|
|
||
|
|
|
||
|
|
class NegBase(object):
|
||
|
|
@classmethod
|
||
|
|
def to_val(cls, name):
|
||
|
|
return getattr(cls, name)
|
||
|
|
|
||
|
|
@classmethod
|
||
|
|
def from_val(cls, val):
|
||
|
|
for k in cls.__dict__.keys():
|
||
|
|
if getattr(cls, k) == val:
|
||
|
|
return k
|
||
|
|
|
||
|
|
return "<unknown>"
|
||
|
|
|
||
|
|
|
||
|
|
class NegTokens(NegBase):
|
||
|
|
# The start of a negotiation sequence
|
||
|
|
IAC = 255
|
||
|
|
# Confirm willingness to negotiate
|
||
|
|
WILL = 251
|
||
|
|
# Confirm unwillingness to negotiate
|
||
|
|
WONT = 252
|
||
|
|
# Indicate willingness to negotiate
|
||
|
|
DO = 253
|
||
|
|
# Indicate unwillingness to negotiate
|
||
|
|
DONT = 254
|
||
|
|
|
||
|
|
# The start of sub-negotiation options.
|
||
|
|
SB = 250
|
||
|
|
# The end of sub-negotiation options.
|
||
|
|
SE = 240
|
||
|
|
|
||
|
|
|
||
|
|
class NegOptions(NegBase):
|
||
|
|
# Binary Transmission
|
||
|
|
BINARY = 0
|
||
|
|
# Suppress Go Ahead
|
||
|
|
SUPPRESS_GO_AHEAD = 3
|
||
|
|
# NAWS - width and height of client
|
||
|
|
NAWS = 31
|
||
|
|
# NEW-ENVIRON - environment variables on client
|
||
|
|
NEW_ENVIRON = 39
|
||
|
|
# Charset option
|
||
|
|
CHARSET = 42
|
||
|
|
|
||
|
|
|
||
|
|
def get_options():
|
||
|
|
parser = argparse.ArgumentParser()
|
||
|
|
|
||
|
|
parser.add_argument("--port", action="store", default=9019,
|
||
|
|
type=int, help="port to listen on")
|
||
|
|
parser.add_argument("--verbose", action="store", type=int, default=0,
|
||
|
|
help="verbose output")
|
||
|
|
parser.add_argument("--pidfile", action="store",
|
||
|
|
help="file name for the PID")
|
||
|
|
parser.add_argument("--logfile", action="store",
|
||
|
|
help="file name for the log")
|
||
|
|
parser.add_argument("--srcdir", action="store", help="test directory")
|
||
|
|
parser.add_argument("--id", action="store", help="server ID")
|
||
|
|
parser.add_argument("--ipv4", action="store_true", default=0,
|
||
|
|
help="IPv4 flag")
|
||
|
|
|
||
|
|
return parser.parse_args()
|
||
|
|
|
||
|
|
|
||
|
|
def setup_logging(options):
|
||
|
|
"""
|
||
|
|
Set up logging from the command line options
|
||
|
|
"""
|
||
|
|
root_logger = logging.getLogger()
|
||
|
|
add_stdout = False
|
||
|
|
|
||
|
|
formatter = logging.Formatter("%(asctime)s %(levelname)-5.5s "
|
||
|
|
"[{ident}] %(message)s"
|
||
|
|
.format(ident=IDENT))
|
||
|
|
|
||
|
|
# Write out to a logfile
|
||
|
|
if options.logfile:
|
||
|
|
handler = ClosingFileHandler(options.logfile)
|
||
|
|
handler.setFormatter(formatter)
|
||
|
|
handler.setLevel(logging.DEBUG)
|
||
|
|
root_logger.addHandler(handler)
|
||
|
|
else:
|
||
|
|
# The logfile wasn't specified. Add a stdout logger.
|
||
|
|
add_stdout = True
|
||
|
|
|
||
|
|
if options.verbose:
|
||
|
|
# Add a stdout logger as well in verbose mode
|
||
|
|
root_logger.setLevel(logging.DEBUG)
|
||
|
|
add_stdout = True
|
||
|
|
else:
|
||
|
|
root_logger.setLevel(logging.INFO)
|
||
|
|
|
||
|
|
if add_stdout:
|
||
|
|
stdout_handler = logging.StreamHandler(sys.stdout)
|
||
|
|
stdout_handler.setFormatter(formatter)
|
||
|
|
stdout_handler.setLevel(logging.DEBUG)
|
||
|
|
root_logger.addHandler(stdout_handler)
|
||
|
|
|
||
|
|
|
||
|
|
class ScriptRC(object):
|
||
|
|
"""Enum for script return codes"""
|
||
|
|
SUCCESS = 0
|
||
|
|
FAILURE = 1
|
||
|
|
EXCEPTION = 2
|
||
|
|
|
||
|
|
|
||
|
|
class ScriptException(Exception):
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == '__main__':
|
||
|
|
# Get the options from the user.
|
||
|
|
options = get_options()
|
||
|
|
|
||
|
|
# Setup logging using the user options
|
||
|
|
setup_logging(options)
|
||
|
|
|
||
|
|
# Run main script.
|
||
|
|
try:
|
||
|
|
rc = telnetserver(options)
|
||
|
|
except Exception as e:
|
||
|
|
log.exception(e)
|
||
|
|
rc = ScriptRC.EXCEPTION
|
||
|
|
|
||
|
|
if options.pidfile and os.path.isfile(options.pidfile):
|
||
|
|
os.unlink(options.pidfile)
|
||
|
|
|
||
|
|
log.info("Returning %d", rc)
|
||
|
|
sys.exit(rc)
|