network: split nat into separate mods

network/src/nat/table.rs

@@ -0,0 +1,21 @@
+use std::collections::HashMap;
+
+use super::{handler::NatHandler, key::NatKey};
+
+pub struct NatTable {
+    pub inner: HashMap<NatKey, Box<dyn NatHandler>>,
+}
+
+impl Default for NatTable {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl NatTable {
+    pub fn new() -> Self {
+        Self {
+            inner: HashMap::new(),
+        }
+    }
+}