diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 2efe89610..8119cd05b 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -310,7 +310,8 @@ class Field(object):
     def __init__(self, read_only=False, write_only=False,
                  required=None, default=empty, initial=empty, source=None,
                  label=None, help_text=None, style=None,
-                 error_messages=None, validators=None, allow_null=False):
+                 error_messages=None, validators=None, allow_null=False,
+                 permission=0, read_permission=0, write_permission=0):
         self._creation_counter = Field._creation_counter
         Field._creation_counter += 1
 
@@ -334,6 +335,9 @@ class Field(object):
         self.help_text = help_text
         self.style = {} if style is None else style
         self.allow_null = allow_null
+        self.permission = permission
+        self.read_permission = read_permission
+        self.write_permission = write_permission
 
         if self.default_empty_html is not empty:
             if default is not empty:
@@ -443,8 +447,6 @@ class Field(object):
         try:
             return get_attribute(instance, self.source_attrs)
         except (KeyError, AttributeError) as exc:
-            if not self.required and self.default is empty:
-                raise SkipField()
             msg = (
                 'Got {exc_type} when attempting to get a value for field '
                 '`{field}` on serializer `{serializer}`.\nThe serializer '
diff --git a/rest_framework/routers.py b/rest_framework/routers.py
index 4e3fbc4de..770635784 100644
--- a/rest_framework/routers.py
+++ b/rest_framework/routers.py
@@ -136,12 +136,14 @@ class SimpleRouter(BaseRouter):
         it from the viewset.
         """
         queryset = getattr(viewset, 'queryset', None)
-
-        assert queryset is not None, '`base_name` argument not specified, and could ' \
+        model = getattr(viewset, 'model', None)
+        
+        assert ((queryset is not None) or (model is not None)), '`base_name` argument not specified, and could ' \
             'not automatically determine the name from the viewset, as ' \
             'it does not have a `.queryset` attribute.'
 
-        return queryset.model._meta.object_name.lower()
+        model = model if model is not None else queryset.model
+        return model._meta.object_name.lower()
 
     def get_routes(self, viewset):
         """
diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index 94c37321f..69cc7a717 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -156,6 +156,14 @@ class BaseSerializer(Field):
         list_serializer_class = getattr(meta, 'list_serializer_class', ListSerializer)
         return list_serializer_class(*args, **list_kwargs)
 
+    '''
+    HACK to pass context down to child serializers in rippling.
+    The right way might be to remove @cached_property from fields.py
+    and set self._context here
+    '''
+    def set_context(self, context):
+        self.context = context;
+
     def to_internal_value(self, data):
         raise NotImplementedError('`to_internal_value()` must be implemented.')