move helper annotations to helpers module

pythonbpf/helper/helpers.py

@@ -0,0 +1,19 @@
+import ctypes
+
+
+def ktime():
+    return ctypes.c_int64(0)
+
+
+def pid():
+    return ctypes.c_int32(0)
+
+
+def deref(ptr):
+    "dereference a pointer"
+    result = ctypes.cast(ptr, ctypes.POINTER(ctypes.c_void_p)).contents.value
+    return result if result is not None else 0
+
+
+XDP_DROP = ctypes.c_int64(1)
+XDP_PASS = ctypes.c_int64(2)