evennia/src/server/telnet.py

"""
This module implements the telnet protocol.

This depends on a generic session module that implements
the actual login procedure of the game, tracks
sessions etc.

"""

import re
from twisted.conch.telnet import Telnet, StatefulTelnetProtocol, IAC, LINEMODE
from src.server.session import Session
from src.server import ttype, mssp
from src.server.mccp import Mccp, mccp_compress, MCCP
from src.utils import utils, ansi, logger

_RE_N = re.compile(r"\{n$")

class TelnetProtocol(Telnet, StatefulTelnetProtocol, Session):
    """
    Each player connecting over telnet (ie using most traditional mud
    clients) gets a telnet protocol instance assigned to them.  All
    communication between game and player goes through here.
    """
    def connectionMade(self):
        """
        This is called when the connection is first
        established.
        """
        # initialize the session
        self.iaw_mode = False
        client_address = self.transport.client
        self.init_session("telnet", client_address, self.factory.sessionhandler)
        # negotiate mccp (data compression)
        self.mccp = Mccp(self)
        # negotiate ttype (client info)
        self.ttype = ttype.Ttype(self)
        # negotiate mssp (crawler communication)
        self.mssp = mssp.Mssp(self)

        # add this new connection to sessionhandler so
        # the Server becomes aware of it.
        self.sessionhandler.connect(self)


    def enableRemote(self, option):
        """
        This sets up the options we allow for this protocol.
        """
        return (option == LINEMODE or
                option == ttype.TTYPE or
                option == MCCP or
                option == mssp.MSSP)

    def enableLocal(self, option):
        """
        Allow certain options on this protocol
        """
        return option == MCCP

    def disableLocal(self, option):
        if option == MCCP:
            self.mccp.no_mccp(option)
            return True
        else:
            return super(TelnetProtocol, self).disableLocal(option)


    def connectionLost(self, reason):
        """
        This is executed when the connection is lost for
        whatever reason. It can also be called directly, from
        the disconnect method
        """
        self.sessionhandler.disconnect(self)
        self.transport.loseConnection()

    def dataReceived(self, data):
        """
        This method will split the incoming data depending on if it
        starts with IAC (a telnet command) or not. All other data will
        be handled in line mode. Some clients also sends an erroneous
        line break after IAC, which we must watch out for.
        """
        #print "dataRcv (%s):" % data,
        #try:
        #    for b in data:
        #        print ord(b),
        #    print ""
        #except Exception, e:
        #    print str(e) + ":", str(data)

        if data and data[0] == IAC or self.iaw_mode:
            try:
                #print "IAC mode"
                super(TelnetProtocol, self).dataReceived(data)
                if len(data) == 1:
                    self.iaw_mode = True
                else:
                    self.iaw_mode = False
                return
            except Exception:
                logger.log_trace()
        # if we get to this point the command must end with a linebreak.
        # We make sure to add it, to fix some clients messing this up.
        data = data.rstrip("\r\n") + "\n"
        #print "line data in:", repr(data)
        StatefulTelnetProtocol.dataReceived(self, data)

    def _write(self, data):
        "hook overloading the one used in plain telnet"
        #print "_write (%s): %s" % (self.state,  " ".join(str(ord(c)) for c in data))
        data = data.replace('\n', '\r\n').replace('\r\r\n', '\r\n')
        #data = data.replace('\n', '\r\n')
        super(TelnetProtocol, self)._write(mccp_compress(self, data))

    def sendLine(self, line):
        "hook overloading the one used by linereceiver"
        #print "sendLine (%s):\n%s" % (self.state, line)
        #escape IAC in line mode, and correctly add \r\n
        line += self.delimiter
        line = line.replace(IAC, IAC + IAC).replace('\n', '\r\n')
        return self.transport.write(mccp_compress(self, line))

    def lineReceived(self, string):
        """
        Telnet method called when data is coming in over the telnet
        connection. We pass it on to the game engine directly.
        """
        self.sessionhandler.data_in(self, string)


    # Session hooks

    def disconnect(self, reason=None):
        """
        generic hook for the engine to call in order to
        disconnect this protocol.
        """
        if reason:
            self.data_out(reason)
        self.connectionLost(reason)

    def data_out(self, string, data=None):
        """
        generic hook method for engine to call in order to send data
        through the telnet connection.
        Data Evennia -> Player.
        data argument may contain a dict with output flags.
        """
        try:
            string = utils.to_str(string, encoding=self.encoding)
        except Exception, e:
            self.sendLine(str(e))
            return
        ttype = self.protocol_flags.get('TTYPE', {})
        nomarkup = not (ttype or ttype.get('256 COLORS') or ttype.get('ANSI') or not ttype.get("init_done"))
        raw = False
        if type(data) == dict:
            # check if we want escape codes to go through unparsed.
            raw = data.get("raw", False)
            # check if we want to remove all markup (TTYPE override)
            nomarkup = data.get("nomarkup", False)
        if raw:
            self.sendLine(string)
        else:
            # we need to make sure to kill the color at the end in order to match the webclient output.
            self.sendLine(ansi.parse_ansi(_RE_N.sub("", string) + "{n", strip_ansi=nomarkup, xterm256=ttype.get('256 COLORS')))