# Reconnect and shutdown

The connector is designed to recover from tunnel interruptions without dropping the SOCKS5 proxy.

## Purpose

Lab networks and development environments are unstable. The connector should tolerate listener restarts, network hiccups, and temporary failures without requiring manual intervention.

## Reconnect behavior

`run_reconnect_loop` in `src/tunnel.rs` continuously attempts to maintain a tunnel:

1. Connect to the target address via TCP.
2. Perform TLS handshake and server certificate verification.
3. Send the HTTP auth request and wait for 200 OK.
4. On success, create a `StreamMux`, publish it via the `watch::channel`, and run the framing loop.
5. When the tunnel drops (framing task ends), log the disconnection and retry.

### Backoff

- Initial delay: 1 second
- Exponential doubling up to a maximum of 30 seconds
- Auth failures are terminal (the loop exits rather than retrying with a bad token)

### SOCKS5 proxy during reconnect

The SOCKS5 proxy stays bound. If a client connects while the tunnel is down, the proxy sees `mux_receiver` is `None` and rejects the connection with a warning log. Once the reconnect loop succeeds, new SOCKS5 requests work immediately.

## Shutdown

Both listener and connector handle graceful shutdown:

- Unix: SIGINT or SIGTERM triggers shutdown via `tokio::signal::unix`.
- Windows: Ctrl+C or Ctrl+Break triggers shutdown via `tokio::signal::ctrl_c`.

### Listener shutdown

1. The shutdown signal breaks the `tokio::select!` in `run_listener`.
2. The TCP listener is dropped, releasing the bind port.
3. The SOCKS5 proxy task (if any) is aborted.
4. Active framing sessions end when their streams close.

### Connector shutdown

1. The shutdown signal breaks the `tokio::select!` in `run_socks5_proxy`.
2. The SOCKS5 listener is dropped.
3. The reconnect loop handle is aborted.
4. Existing SOCKS5 connections receive EOF when their streams close.

E2E tests `e2e_graceful_shutdown_listener` and `e2e_graceful_shutdown_connector` verify that ports are released within 3 seconds of abort.

## Key source files

| File | Purpose |
| ---- | ------- |
| `src/tunnel.rs` | `run_reconnect_loop`, `run_socks5_proxy`, `run_listener`, shutdown handling |
| `src/signal.rs` | Cross-platform shutdown signal future |