diff options
Diffstat (limited to 'snekbox.py')
| -rw-r--r-- | snekbox.py | 34 |
1 files changed, 29 insertions, 5 deletions
@@ -7,14 +7,15 @@ import sys from rmq import Rmq -class Snekbox(object): +class Snekbox: + """Core snekbox functionality, providing safe execution of Python code.""" + def __init__(self, nsjail_binary='nsjail', - python_binary=os.path.dirname(sys.executable)+os.sep+'python3.6'): - + python_binary=os.path.dirname(sys.executable) + os.sep + 'python3.6'): self.nsjail_binary = nsjail_binary self.python_binary = python_binary - self.nsjail_workaround() + self._nsjail_workaround() env = { 'PATH': ( @@ -27,13 +28,24 @@ class Snekbox(object): 'PYTHONDONTWRITEBYTECODE': '1', } - def nsjail_workaround(self): + def _nsjail_workaround(self): dirs = ['/sys/fs/cgroup/pids/NSJAIL', '/sys/fs/cgroup/memory/NSJAIL'] for d in dirs: if not os.path.exists(d): os.makedirs(d) def python3(self, cmd): + """ + Execute Python 3 code in a isolated environment. + + The value of ``cmd`` is passed using '-c' to a Python + interpreter that is started in a ``nsjail``, isolating it + from the rest of the system. + + Returns the output of executing the command (stdout) if + successful, or a error message if the execution failed. + """ + args = [self.nsjail_binary, '-Mo', '--rlimit_as', '700', '--chroot', '/', @@ -87,6 +99,16 @@ class Snekbox(object): return output def execute(self, body): + """ + Handles execution of a raw JSON-formatted RMQ message, contained in ``body``. + + The message metadata, including the Python code to be executed, is + extracted from the message body. The code is then executed in the + isolated environment, and the results of the execution published + to RMQ. Once published, the system exits, since the snekboxes + are created and disposed of per-execution. + """ + msg = body.decode('utf-8') result = '' snek_msg = json.loads(msg) @@ -102,6 +124,8 @@ class Snekbox(object): exit(0) def message_handler(self, ch, method, properties, body, thread_ws=None): + """Spawns a daemon process that handles RMQ messages.""" + p = multiprocessing.Process(target=self.execute, args=(body,)) p.daemon = True p.start() |