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# Copyright (C) 2007-2008 The University of Melbourne
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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# Author: Matt Giuca, Tom Conway, David Coles (refactor)
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# Mainly refactored out of consoleservice
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from common import (chat, util)
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trampoline_path = os.path.join(conf.ivle_install_dir, "bin/trampoline")
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python_path = "/usr/bin/python"
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console_dir = "/opt/ivle/scripts"
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console_path = "/opt/ivle/scripts/python-console"
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class ConsoleError(Exception):
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""" The console failed in some way. This is bad. """
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def __init__(self, value):
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return repr(self.value)
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class ConsoleException(Exception):
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""" The code being exectuted on the console returned an exception.
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def __init__(self, value):
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return repr(self.value)
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class Console(object):
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""" Provides a nice python interface to the console
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def __init__(self, uid, jail_path, working_dir):
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"""Starts up a console service for user uid, inside chroot jail
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jail_path with work directory of working_dir
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self.jail_path = jail_path
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self.working_dir = working_dir
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# TODO: Check if we are already running a console. If we are shut it
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# TODO: Figure out the host name the console server is running on.
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self.host = socket.gethostname()
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self.magic = md5.new(uuid.uuid4().bytes).digest().encode('hex')
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# Try to find a free port on the server.
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# Just try some random ports in the range [3000,8000)
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# until we either succeed, or give up. If you think this
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# sounds risky, it isn't:
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# For N ports (e.g. 5000) with k (e.g. 100) in use, the
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# probability of failing to find a free port in t (e.g. 5) tries
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# is (k / N) ** t (e.g. 3.2*10e-9).
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self.port = int(random.uniform(3000, 8000))
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# Start the console server (port, magic)
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# trampoline usage: tramp uid jail_dir working_dir script_path args
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# console usage: python-console port magic
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# If we can't start the console after 5 attemps (can't find a free port
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# during random probing, syntax errors, segfaults) throw an exception.
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raise ConsoleError("Unable to start console service!")
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def __chat(self, cmd, args):
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""" A wrapper around chat.chat to comunicate directly with the
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response = chat.chat(self.host, self.port,
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{'cmd': cmd, 'text': args}, self.magic)
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except socket.error, (enumber, estring):
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if enumber == errno.ECONNREFUSED:
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"Could not establish a connection to the python console")
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# Some other error - probably serious
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raise socket.error, (enumber, estring)
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except cjson.DecodeError:
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# Couldn't decode the JSON
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"Could not understand the python console response")
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# Look for user errors
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if 'exc' in response:
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raise ConsoleException(response['exc'])
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def chat(self, code=''):
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""" Executes a partial block of code """
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return self.__chat('chat', code)
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def block(self, code):
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""" Executes a block of code and returns the output """
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block = self.__chat('block', code)
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if 'output' in block:
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return block['output']
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elif 'okay' in block:
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raise ConsoleException("Bad response from console: %s"%str(block))
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def flush(self, globs=None):
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""" Resets the consoles globals() to the default and optionally augment
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them with a dictionary simple globals. (Must be able to be pickled)
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if globs is not None:
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pickled_globs[g] = cPickle.dumps(globs[g])
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flush = self.__chat('flush', pickled_globs)
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if 'response' in flush and flush['response'] == 'okay':
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raise ConsoleError("Bad response from console: %s"%str(flush))
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def call(self, function, *args, **kwargs):
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""" Calls a function in the python console. Can take in a list of
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repr() args and dictionary of repr() values kwargs. These will be
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evaluated on the server side.
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'function': function,
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call = self.__chat('call', call_args)
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# Unpickle any exceptions
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if 'exception' in call:
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call['exception']['except'] = \
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cPickle.loads(call['exception']['except'])
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def inspect(self, code=''):
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""" Runs a block of code in the python console returning a dictionary
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summary of the evaluation. Currently this includes the values of
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stdout, stderr, simple global varibles.
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If an exception was thrown then this dictionary also includes a
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exception dictionary containg a traceback string and the exception
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inspection = self.__chat('inspect', code)
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# Unpickle the globals
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for g in inspection['globals']:
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inspection['globals'][g] = cPickle.loads(inspection['globals'][g])
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# Unpickle any exceptions
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if 'exception' in inspection:
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inspection['exception']['except'] = \
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cPickle.loads(inspection['exception']['except'])
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def set_vars(self, variables):
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""" Takes a dictionary of varibles to add to the console's global
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space. These are evaluated in the local space so you can't use this to
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set a varible to a value to be calculated on the console side.
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vars[v] = repr(variables[v])
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set_vars = self.__chat('set_vars', vars)
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if set_vars.get('response') != 'okay':
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raise ConsoleError("Could not set variables")
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""" Causes the console process to terminate """
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self.__chat('restart', None)
added
removed
lib/common/console.py
