"""\
@file backdoor.py
@author Bob Ippolito

Copyright (c) 2005-2006, Bob Ippolito
Copyright (c) 2007, Linden Research, Inc.
Copyright (c) 2008, Donovan Preston

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
"""

import socket
import sys
from code import InteractiveConsole
from eventlet import greenlib

from eventlet import api
from eventlet.support import greenlets

try:
    sys.ps1
except AttributeError:
    sys.ps1 = '>>> '
try:
    sys.ps2
except AttributeError:
    sys.ps2 = '... '


class SocketConsole(greenlets.greenlet):
    def __init__(self, desc, hostport, locals):
        self.hostport = hostport
        self.locals = locals
        # mangle the socket
        self.desc = desc
        readline = desc.readline
        self.old = {}
        self.fixups = {
            'softspace': 0,
            'isatty': lambda: True,
            'flush': lambda: None,
            'readline': lambda *a: readline(*a).replace('\r\n', '\n'),
        }
        for key, value in self.fixups.iteritems():
            if hasattr(desc, key):
                self.old[key] = getattr(desc, key)
            setattr(desc, key, value)

        greenlets.greenlet.__init__(self)

    def run(self):
        try:
            console = InteractiveConsole(self.locals)
            console.interact()
        finally:
            self.switch_out()
            self.finalize()

    def switch(self, *args, **kw):
        self.saved = sys.stdin, sys.stderr, sys.stdout
        sys.stdin = sys.stdout = sys.stderr = self.desc
        greenlets.greenlet.switch(self, *args, **kw)

    def switch_out(self):
        sys.stdin, sys.stderr, sys.stdout = self.saved

    def finalize(self):
        # restore the state of the socket
        for key in self.fixups:
            try:
                value = self.old[key]
            except KeyError:
                delattr(self.desc, key)
            else:
                setattr(self.desc, key, value)
        self.fixups.clear()
        self.old.clear()
        self.desc = None
        print "backdoor closed to %s:%s" % self.hostport


def backdoor_server(server, locals=None):
    print "backdoor listening on %s:%s" % server.getsockname()
    try:
        try:
            while True:
                (conn, (host, port)) = server.accept()
                print "backdoor connected to %s:%s" % (host, port)
                fl = conn.makeGreenFile("rw")
                fl.newlines = '\n'
                greenlet = SocketConsole(fl, (host, port), locals)
                hub = api.get_hub()
                hub.schedule_call_global(0, greenlet.switch)
                hub.switch()
        except socket.error, e:
            # Broken pipe means it was shutdown
            if e[0] != 32:
                raise
    finally:
        server.close()