krata: restructure packages for cleanliness

crates/network/src/nat/handler.rs

@@ -0,0 +1,36 @@
+use anyhow::Result;
+use async_trait::async_trait;
+use bytes::BytesMut;
+use tokio::sync::mpsc::Sender;
+
+use super::key::NatKey;
+
+#[derive(Debug, Clone)]
+pub struct NatHandlerContext {
+    pub mtu: usize,
+    pub key: NatKey,
+    pub transmit_sender: Sender<BytesMut>,
+    pub reclaim_sender: Sender<NatKey>,
+}
+
+impl NatHandlerContext {
+    pub fn try_transmit(&self, buffer: BytesMut) -> Result<()> {
+        self.transmit_sender.try_send(buffer)?;
+        Ok(())
+    }
+
+    pub async fn reclaim(&self) -> Result<()> {
+        let _ = self.reclaim_sender.try_send(self.key);
+        Ok(())
+    }
+}
+
+#[async_trait]
+pub trait NatHandler: Send {
+    async fn receive(&self, packet: &[u8]) -> Result<bool>;
+}
+
+#[async_trait]
+pub trait NatHandlerFactory: Send {
+    async fn nat(&self, context: NatHandlerContext) -> Option<Box<dyn NatHandler>>;
+}