network: split nat into separate mods

network/src/nat/mod.rs

@@ -0,0 +1,42 @@
+use anyhow::Result;
+use tokio::sync::mpsc::Sender;
+
+use self::handler::NatHandlerFactory;
+use self::processor::NatProcessor;
+use bytes::BytesMut;
+use smoltcp::wire::EthernetAddress;
+use smoltcp::wire::IpCidr;
+use tokio::task::JoinHandle;
+
+pub mod handler;
+pub mod key;
+pub mod processor;
+pub mod table;
+
+pub struct Nat {
+    pub receive_sender: Sender<BytesMut>,
+    task: JoinHandle<()>,
+}
+
+impl Nat {
+    pub fn new(
+        mtu: usize,
+        factory: Box<dyn NatHandlerFactory>,
+        local_mac: EthernetAddress,
+        local_cidrs: Vec<IpCidr>,
+        transmit_sender: Sender<BytesMut>,
+    ) -> Result<Self> {
+        let (receive_sender, task) =
+            NatProcessor::launch(mtu, factory, local_mac, local_cidrs, transmit_sender)?;
+        Ok(Self {
+            receive_sender,
+            task,
+        })
+    }
+}
+
+impl Drop for Nat {
+    fn drop(&mut self) {
+        self.task.abort();
+    }
+}