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-rwxr-xr-xtests/negtelnetserver.py349
1 files changed, 349 insertions, 0 deletions
diff --git a/tests/negtelnetserver.py b/tests/negtelnetserver.py
new file mode 100755
index 000000000..8cfd4093b
--- /dev/null
+++ b/tests/negtelnetserver.py
@@ -0,0 +1,349 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+""" A telnet server which negotiates"""
+
+from __future__ import (absolute_import, division, print_function,
+ unicode_literals)
+import argparse
+import os
+import sys
+import logging
+import struct
+try: # Python 2
+ import SocketServer as socketserver
+except ImportError: # Python 3
+ import socketserver
+
+
+log = logging.getLogger(__name__)
+HOST = "localhost"
+IDENT = "NTEL"
+
+
+# The strings that indicate the test framework is checking our aliveness
+VERIFIED_REQ = b"verifiedserver"
+VERIFIED_RSP = b"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()
+ with open(options.pidfile, "w") as f:
+ f.write(b"{0}".format(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
+ server = socketserver.TCPServer(local_bind, NegotiatingTelnetHandler)
+ server.serve_forever()
+
+ 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(1024)
+ log.debug("Incoming data: %r", data)
+
+ if VERIFIED_REQ in data:
+ log.debug("Received verification request from test framework")
+ response_data = VERIFIED_RSP.format(pid=os.getpid())
+ else:
+ log.debug("Received normal request - echoing back")
+ response_data = data.strip()
+
+ if response_data:
+ log.debug("Sending %r", response_data)
+ self.request.sendall(response_data)
+
+ 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 in data:
+ byte_int = self.byte_to_int(byte)
+
+ if self.state == self.NO_NEG:
+ self.no_neg(byte, 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 byte_to_int(self, byte):
+ return struct.unpack(b'B', byte)[0]
+
+ def no_neg(self, byte, 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)
+
+ 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):
+ packed_message = self.pack(message)
+ self.tcp.sendall(packed_message)
+
+ def pack(self, arr):
+ return struct.pack(b'{0}B'.format(len(arr)), *arr)
+
+ 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 = logging.FileHandler(options.logfile, mode="w")
+ 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
+
+ log.info("Returning %d", rc)
+ sys.exit(rc)