Merge pull request #479 from gschaffner/exposed-descriptor-AttributeE…

…rror

Fix propagation of AttributeErrors raised by exposed descriptors

rpyc/core/protocol.py

@@ -6,6 +6,7 @@
 import time  # noqa: F401
 import gc  # noqa: F401
 
+from inspect import getattr_static
 from threading import Lock, Condition, RLock
 from rpyc.lib import spawn, Timeout, get_methods, get_id_pack
 from rpyc.lib.compat import pickle, next, maxint, select_error, acquire_lock  # noqa: F401
@@ -524,6 +525,15 @@ def root(self):  # serving
         return self._remote_root
 
     def _check_attr(self, obj, name, perm):  # attribute access
+        def hasattr_static(obj, name):
+            try:
+                getattr_static(obj, name)
+            except AttributeError:
+                return False
+            else:
+                return True
+
+
         config = self._config
         if not config[perm]:
             raise AttributeError(f"cannot access {name!r}")
@@ -532,7 +542,7 @@ def _check_attr(self, obj, name, perm):  # attribute access
         plain |= config["allow_exposed_attrs"] and name.startswith(prefix)
         plain |= config["allow_safe_attrs"] and name in config["safe_attrs"]
         plain |= config["allow_public_attrs"] and not name.startswith("_")
-        has_exposed = prefix and hasattr(obj, prefix + name)
+        has_exposed = prefix and (hasattr(obj, prefix + name) or hasattr_static(obj, prefix + name))
         if plain and (not has_exposed or hasattr(obj, name)):
             return name
         if has_exposed:

tests/test_attr_access.py

@@ -74,6 +74,16 @@ def _rpyc_getattr(_, name):
 SVC_RESTRICTED = ["exposed_foobar", "__add__", "_privy", "foo", "bar"]
 
 
+class MyDescriptor1(object):
+    def __get__(self, instance, owner=None):
+        raise AttributeError("abcd")
+
+
+class MyDescriptor2(object):
+    def __get__(self, instance, owner=None):
+        raise RuntimeError("efgh")
+
+
 class MyService(rpyc.Service):
     exposed_MyClass = MyClass
 
@@ -86,6 +96,10 @@ def exposed_get_two(self):
         protector.register(YourClass, ["lala", "baba"])
         return protector.wrap(YourClass())
 
+    exposed_desc_1 = MyDescriptor1()
+
+    exposed_desc_2 = MyDescriptor2()
+
 
 class TestRestricted(unittest.TestCase):
     def setUp(self):
@@ -152,6 +166,11 @@ def test_default_config(self):
         self.assertRaises(AttributeError, lambda: obj.foo)
         self.assertRaises(AttributeError, lambda: obj.bar)
         self.assertRaises(AttributeError, lambda: obj.spam)
+        root = self.conn.root
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.exposed_desc_1)
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.desc_1)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.exposed_desc_2)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.desc_2)
 
     def test_allow_all(self):
         self._reset_cfg()
@@ -162,6 +181,11 @@ def test_allow_all(self):
         self.assertEqual(obj._privy(), "privy")
         self.assertEqual(obj.foobar(), "Fee Fie Foe Foo")
         self.assertEqual(obj.exposed_foobar(), "Fee Fie Foe Foo")
+        root = self.conn.root
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.exposed_desc_1)
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.desc_1)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.exposed_desc_2)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.desc_2)
 
     def test_allow_exposed(self):
         self._reset_cfg()
@@ -172,6 +196,11 @@ def test_allow_exposed(self):
         except Exception:
             passed = True
         self.assertEqual(passed, True)
+        root = self.conn.root
+        self.assertRaises(AttributeError, lambda: root.exposed_desc_1)
+        self.assertRaises(AttributeError, lambda: root.desc_1)
+        self.assertRaises(AttributeError, lambda: root.exposed_desc_2)
+        self.assertRaises(AttributeError, lambda: root.desc_2)
 
     def test_allow_safe_attrs(self):
         self._reset_cfg()
@@ -184,6 +213,11 @@ def test_allow_safe_attrs(self):
         self.assertRaises(AttributeError, lambda: obj.foo)
         self.assertRaises(AttributeError, lambda: obj.bar)
         self.assertRaises(AttributeError, lambda: obj.spam)
+        root = self.conn.root
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.exposed_desc_1)
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.desc_1)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.exposed_desc_2)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.desc_2)
 
     def test_allow_public_attrs(self):
         self._reset_cfg()
@@ -195,6 +229,11 @@ def test_allow_public_attrs(self):
         self.assertEqual(obj.foobar(), "Fee Fie Foe Foo")
         self.assertEqual(obj.exposed_foobar(), "Fee Fie Foe Foo")
         self.assertRaises(AttributeError, lambda: obj._privy)
+        root = self.conn.root
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.exposed_desc_1)
+        self.assertRaisesRegex(AttributeError, "abcd", lambda: root.desc_1)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.exposed_desc_2)
+        self.assertRaisesRegex(RuntimeError, "efgh", lambda: root.desc_2)
 
 #    def test_type_protector(self):
 #        obj = self.conn.root.get_two()