structure libmproxy.script

4 files changed, 255 insertions, 0 deletions

diff --git a/libmproxy/script/__init__.py b/libmproxy/script/__init__.py
new file mode 100644
index 00000000..0f487795
--- /dev/null
+++ b/libmproxy/script/__init__.py
@@ -0,0 +1,11 @@
+from .script import Script, script_change
+from .script_context import ScriptContext
+from .concurrent import concurrent
+from ..exceptions import ScriptException
+
+__all__ = [
+    "Script", "script_change",
+    "ScriptContext",
+    "concurrent",
+    "ScriptException"
+]
\ No newline at end of file
diff --git a/libmproxy/script/concurrent.py b/libmproxy/script/concurrent.py
new file mode 100644
index 00000000..bee2d43b
--- /dev/null
+++ b/libmproxy/script/concurrent.py
@@ -0,0 +1,62 @@
+"""
+This module provides a @concurrent decorator primitive to
+offload computations from mitmproxy's main master thread.
+"""
+from __future__ import absolute_import, print_function, division
+import threading
+
+
+class ReplyProxy(object):
+    def __init__(self, original_reply, script_thread):
+        self.original_reply = original_reply
+        self.script_thread = script_thread
+        self._ignore_call = True
+        self.lock = threading.Lock()
+
+    def __call__(self, *args, **kwargs):
+        with self.lock:
+            if self._ignore_call:
+                self.script_thread.start()
+                self._ignore_call = False
+                return
+        self.original_reply(*args, **kwargs)
+
+    def __getattr__(self, k):
+        return getattr(self.original_reply, k)
+
+
+def _handle_concurrent_reply(fn, o, *args, **kwargs):
+    # Make first call to o.reply a no op and start the script thread.
+    # We must not start the script thread before, as this may lead to a nasty race condition
+    # where the script thread replies a different response before the normal reply, which then gets swallowed.
+
+    def run():
+        fn(*args, **kwargs)
+        # If the script did not call .reply(), we have to do it now.
+        reply_proxy()
+
+    script_thread = ScriptThread(target=run)
+
+    reply_proxy = ReplyProxy(o.reply, script_thread)
+    o.reply = reply_proxy
+
+
+class ScriptThread(threading.Thread):
+    name = "ScriptThread"
+
+
+def concurrent(fn):
+    if fn.func_name in (
+            "request",
+            "response",
+            "error",
+            "clientconnect",
+            "serverconnect",
+            "clientdisconnect",
+            "next_layer"):
+        def _concurrent(ctx, obj):
+            _handle_concurrent_reply(fn, obj, ctx, obj)
+
+        return _concurrent
+    raise NotImplementedError(
+        "Concurrent decorator not supported for '%s' method." % fn.func_name)
diff --git a/libmproxy/script/script.py b/libmproxy/script/script.py
new file mode 100644
index 00000000..a58ba0af
--- /dev/null
+++ b/libmproxy/script/script.py
@@ -0,0 +1,123 @@
+"""
+The script object representing mitmproxy inline scripts.
+Script objects know nothing about mitmproxy or mitmproxy's API - this knowledge is provided
+by the mitmproxy-specific ScriptContext.
+"""
+from __future__ import absolute_import, print_function, division
+import os
+import shlex
+import traceback
+import sys
+import blinker
+
+from watchdog.events import PatternMatchingEventHandler, FileModifiedEvent
+from watchdog.observers import Observer
+
+from ..exceptions import ScriptException
+
+script_change = blinker.Signal()
+
+
+class Script(object):
+    """
+        Script object representing an inline script.
+    """
+
+    def __init__(self, command, context, use_reloader=True):
+        self.command = command
+        self.args = self.parse_command(command)
+        self.ctx = context
+        self.ns = None
+        self.load()
+        if use_reloader:
+            self.start_observe()
+
+    @classmethod
+    def parse_command(cls, command):
+        if not command or not command.strip():
+            raise ScriptException("Empty script command.")
+        if os.name == "nt":  # Windows: escape all backslashes in the path.
+            backslashes = shlex.split(command, posix=False)[0].count("\\")
+            command = command.replace("\\", "\\\\", backslashes)
+        args = shlex.split(command)
+        args[0] = os.path.expanduser(args[0])
+        if not os.path.exists(args[0]):
+            raise ScriptException(
+                ("Script file not found: %s.\r\n"
+                 "If your script path contains spaces, "
+                 "make sure to wrap it in additional quotes, e.g. -s \"'./foo bar/baz.py' --args\".") %
+                args[0])
+        elif os.path.isdir(args[0]):
+            raise ScriptException("Not a file: %s" % args[0])
+        return args
+
+    def load(self):
+        """
+            Loads an inline script.
+
+            Returns:
+                The return value of self.run("start", ...)
+
+            Raises:
+                ScriptException on failure
+        """
+        if self.ns is not None:
+            self.unload()
+        script_dir = os.path.dirname(os.path.abspath(self.args[0]))
+        ns = {'__file__': os.path.abspath(self.args[0])}
+        sys.path.append(script_dir)
+        try:
+            execfile(self.args[0], ns, ns)
+        except Exception as e:
+            # Python 3: use exception chaining, https://www.python.org/dev/peps/pep-3134/
+            raise ScriptException(traceback.format_exc(e))
+        sys.path.pop()
+        self.ns = ns
+        return self.run("start", self.args)
+
+    def unload(self):
+        ret = self.run("done")
+        self.ns = None
+        return ret
+
+    def run(self, name, *args, **kwargs):
+        """
+            Runs an inline script hook.
+
+            Returns:
+                The return value of the method.
+                None, if the script does not provide the method.
+
+            Raises:
+                ScriptException if there was an exception.
+        """
+        f = self.ns.get(name)
+        if f:
+            try:
+                return f(self.ctx, *args, **kwargs)
+            except Exception as e:
+                raise ScriptException(traceback.format_exc(e))
+        else:
+            return None
+
+    def start_observe(self):
+        script_dir = os.path.dirname(self.args[0])
+        event_handler = ScriptModified(self)
+        observer = Observer()
+        observer.schedule(event_handler, script_dir)
+        observer.start()
+
+    def stop_observe(self):
+        raise NotImplementedError() # FIXME
+
+
+class ScriptModified(PatternMatchingEventHandler):
+    def __init__(self, script):
+        # We could enumerate all relevant *.py files (as werkzeug does it),
+        # but our case looks like it isn't as simple as enumerating sys.modules.
+        # This should be good enough for now.
+        super(ScriptModified, self).__init__(ignore_directories=True, patterns=["*.py"])
+        self.script = script
+
+    def on_modified(self, event=FileModifiedEvent):
+        script_change.send(self.script)
diff --git a/libmproxy/script/script_context.py b/libmproxy/script/script_context.py
new file mode 100644
index 00000000..d8748cb2
--- /dev/null
+++ b/libmproxy/script/script_context.py
@@ -0,0 +1,59 @@
+"""
+The mitmproxy script context provides an API to inline scripts.
+"""
+from __future__ import absolute_import, print_function, division
+from .. import contentviews
+
+
+class ScriptContext(object):
+    """
+    The script context should be used to interact with the global mitmproxy state from within a
+    script.
+    """
+
+    def __init__(self, master):
+        self._master = master
+
+    def log(self, message, level="info"):
+        """
+        Logs an event.
+
+        By default, only events with level "error" get displayed. This can be controlled with the "-v" switch.
+        How log messages are handled depends on the front-end. mitmdump will print them to stdout,
+        mitmproxy sends output to the eventlog for display ("e" keyboard shortcut).
+        """
+        self._master.add_event(message, level)
+
+    def kill_flow(self, f):
+        """
+        Kills a flow immediately. No further data will be sent to the client or the server.
+        """
+        f.kill(self._master)
+
+    def duplicate_flow(self, f):
+        """
+        Returns a duplicate of the specified flow. The flow is also
+        injected into the current state, and is ready for editing, replay,
+        etc.
+        """
+        self._master.pause_scripts = True
+        f = self._master.duplicate_flow(f)
+        self._master.pause_scripts = False
+        return f
+
+    def replay_request(self, f):
+        """
+        Replay the request on the current flow. The response will be added
+        to the flow object.
+        """
+        return self._master.replay_request(f, block=True, run_scripthooks=False)
+
+    @property
+    def app_registry(self):
+        return self._master.apps
+
+    def add_contentview(self, view_obj):
+        contentviews.add(view_obj)
+
+    def remove_contentview(self, view_obj):
+        contentviews.remove(view_obj)