feat(net): auto-map the listen port via UPnP-IGD and NAT-PMP
Behind a home router the client is unreachable for incoming peer connections, so browsing/downloading firewalled peers (and the server-brokered connect-back) times out. Add a best-effort port mapper to the binary crate that, when listening is enabled, makes us reachable: - NAT-PMP (RFC 6886) hand-rolled on std::net::UdpSocket, zero deps, with an injectable gateway address so it is fully testable. - UPnP-IGD via the blocking igd-next crate as the primary path. - A background PortMapper that discovers off the main thread (never blocks startup), renews at half the lease, and removes the mapping on drop. Any failure is non-fatal and logged. - Maps the EXACT listen port only (we advertise it verbatim via SetWaitPort, so a different external port would be unreachable) and warns the user to forward manually otherwise. Wired into the TUI, search, and CLI browse (the P2P modes); chat/rooms/ messaging are server-mediated and skip it. e2e-tested against an in-process mock NAT-PMP gateway: the map request bytes, response parsing, result-code/timeout handling, and the full spawn -> map -> drop -> unmap service lifecycle.
This commit is contained in:
michel
@@ -23,3 +23,4 @@ clap = { version = "4.6.2", features = ["derive", "color", "wrap_help", "env"] }
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ratatui = "0.30.2"
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color-eyre = "0.6.5"
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dotenv = "0.15.0"
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igd-next = "0.17"
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@@ -2,6 +2,7 @@ mod cli;
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mod config;
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mod directories;
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mod models;
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mod port_mapping;
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mod ui;
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use clap::Parser;
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@@ -160,6 +161,12 @@ fn main() -> Result<()> {
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shared_directory,
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};
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// Best-effort: make ourselves reachable behind a home router so
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// firewalled peers can connect back. Kept alive for the session.
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let _port_mapper = settings
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.enable_listen
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.then(|| port_mapping::PortMapper::spawn(settings.listen_port));
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let mut client = Client::with_settings(settings);
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client.connect().map_err(|e| {
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color_eyre::eyre::eyre!("Failed to connect: {}", e)
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@@ -193,6 +200,9 @@ fn main() -> Result<()> {
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fn browse_user(settings: &ClientSettings, target: &str) -> Result<()> {
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use std::time::Instant;
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let _port_mapper = settings
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.enable_listen
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.then(|| port_mapping::PortMapper::spawn(settings.listen_port));
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let mut client = Client::with_settings(settings.clone());
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client
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.connect()
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@@ -378,6 +388,10 @@ fn search_and_download(config: SearchConfig) -> Result<()> {
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shared_directory: config.shared_directory.clone(),
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};
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let _port_mapper = settings
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.enable_listen
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.then(|| port_mapping::PortMapper::spawn(settings.listen_port));
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let mut client = Client::with_settings(settings);
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client
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.connect()
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@@ -0,0 +1,382 @@
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//! Best-effort automatic port mapping so a client behind a home router becomes
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//! reachable for incoming peer connections (browse/download of firewalled peers
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//! and the server-brokered connect-back both need this).
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//!
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//! Tries UPnP-IGD (via the `igd-next` crate) first, then hand-rolled NAT-PMP
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//! (see [`nat_pmp`]). Everything is best-effort: any failure is logged and the
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//! program continues (the user can still reach non-firewalled peers, and can
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//! port-forward manually). The mapping is renewed on a timer and removed on
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//! shutdown.
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mod nat_pmp;
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use std::net::{IpAddr, Ipv4Addr, SocketAddr, UdpSocket};
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use std::sync::Arc;
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use std::sync::atomic::{AtomicBool, Ordering};
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use std::thread::{self, JoinHandle};
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use std::time::{Duration, Instant};
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use igd_next::{PortMappingProtocol, SearchOptions, search_gateway};
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use soulseek_rs::utils::logger::{self, LogLevel};
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const MAPPING_DESCRIPTION: &str = "soulseek-rs";
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/// Lease we request; both backends renew at half this interval.
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const LEASE_SECS: u32 = nat_pmp::RECOMMENDED_LIFETIME;
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/// Interactive NAT-PMP retransmit budget (~3.75s worst case), not the full 9.
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const NATPMP_ATTEMPTS: u32 = 4;
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/// A live port mapping and its renewal thread. Dropping it stops renewal and
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/// removes the mapping (best-effort).
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pub struct PortMapper {
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stop: Arc<AtomicBool>,
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handle: Option<JoinHandle<()>>,
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}
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impl PortMapper {
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/// Spawn a background best-effort mapper for TCP `port`. Returns immediately;
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/// discovery/mapping happens on the thread so startup never blocks.
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#[must_use]
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pub fn spawn(port: u16) -> Self {
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let stop = Arc::new(AtomicBool::new(false));
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let thread_stop = stop.clone();
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let handle = thread::Builder::new()
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.name("port-mapper".into())
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.spawn(move || run(port, &thread_stop))
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.ok();
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Self { stop, handle }
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}
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}
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impl Drop for PortMapper {
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fn drop(&mut self) {
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self.stop.store(true, Ordering::SeqCst);
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if let Some(handle) = self.handle.take() {
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let _ = handle.join();
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}
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}
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}
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/// Which backend created the active mapping, carrying what's needed to renew and
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/// remove it.
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enum Backend {
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Upnp {
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gateway: Box<igd_next::Gateway>,
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local_addr: SocketAddr,
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external_port: u16,
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},
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NatPmp {
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gateway: SocketAddr,
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internal_port: u16,
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},
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}
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fn run(port: u16, stop: &AtomicBool) {
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let Some(local_ip) = local_lan_ip() else {
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warn(
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"could not determine this machine's LAN IP; skipping automatic \
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port mapping (you may need to forward the port manually)",
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);
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return;
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};
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let Some((backend, lease)) = map_once(local_ip, port) else {
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warn(&format!(
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"automatic port mapping unavailable (no UPnP/NAT-PMP router \
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found for port {port}); browsing/downloading firewalled peers \
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may fail unless you forward TCP {port} on your router"
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));
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return;
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};
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manage(&backend, lease, port, stop);
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}
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/// Renew `backend`'s mapping until `stop`, then remove it. Renews at half the
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/// granted lease, floored at 30s so a pathologically short lease can't spin us
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/// into a hot re-map loop.
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fn manage(backend: &Backend, lease: u32, port: u16, stop: &AtomicBool) {
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let renew_after = Duration::from_secs(u64::from((lease / 2).max(30)));
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loop {
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if sleep_until(renew_after, stop) {
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break; // asked to stop
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}
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if !renew(backend, port) {
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// Renewal failed; the lease will expire on its own. Stop trying.
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warn("failed to renew the port mapping; it may expire");
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return;
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}
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}
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remove(backend);
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}
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/// Attempt UPnP then NAT-PMP once. Returns the backend and granted lease seconds.
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fn map_once(local_ip: IpAddr, port: u16) -> Option<(Backend, u32)> {
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if let Some(result) = map_upnp(local_ip, port) {
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return Some(result);
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}
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map_natpmp(port)
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}
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fn map_upnp(local_ip: IpAddr, port: u16) -> Option<(Backend, u32)> {
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let options = SearchOptions {
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bind_addr: SocketAddr::new(local_ip, 0),
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timeout: Some(Duration::from_secs(5)),
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..SearchOptions::default()
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};
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let gateway = search_gateway(options).ok()?;
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let local_addr = SocketAddr::new(local_ip, port);
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// We advertise our listen port verbatim to the Soulseek server, so the
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// EXTERNAL port must equal it. If the exact port can't be mapped (e.g.
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// another LAN device already claimed it), a different external port would
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// be unreachable for our advertised address, so we give up rather than map
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// a useless port.
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if let Err(e) = gateway.add_port(
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PortMappingProtocol::TCP,
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port,
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local_addr,
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LEASE_SECS,
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MAPPING_DESCRIPTION,
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) {
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warn(&format!(
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"UPnP found a router but couldn't map port {port} ({e}); \
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try a different --listener-port or forward it manually"
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));
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return None;
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}
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let external = gateway
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.get_external_ip()
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.map_or_else(|_| "?".to_string(), |ip| ip.to_string());
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info(&format!(
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"UPnP: mapped external {external}:{port} -> local {port}"
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));
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Some((
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Backend::Upnp {
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gateway: Box::new(gateway),
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local_addr,
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external_port: port,
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},
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LEASE_SECS,
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))
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}
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fn map_natpmp(port: u16) -> Option<(Backend, u32)> {
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let gateway_ip = nat_pmp::default_gateway()?;
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let gateway =
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SocketAddr::new(IpAddr::V4(gateway_ip), nat_pmp::NAT_PMP_PORT);
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let response =
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nat_pmp::map_tcp(gateway, port, port, LEASE_SECS, NATPMP_ATTEMPTS)
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.ok()?;
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// We advertise our listen port verbatim, so a different external port would
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// be unreachable for peers. Keep the mapping but warn loudly.
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if response.external_port != port {
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warn(&format!(
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"NAT-PMP granted external port {} instead of {port}; peers may not \
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reach you — try forwarding TCP {port} manually",
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response.external_port
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));
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}
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info(&format!(
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"NAT-PMP: mapped external port {} -> local {port} (lease {}s)",
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response.external_port, response.lifetime
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));
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Some((
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Backend::NatPmp {
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gateway,
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internal_port: port,
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},
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response.lifetime,
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))
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}
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fn renew(backend: &Backend, port: u16) -> bool {
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match backend {
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Backend::Upnp {
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gateway,
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local_addr,
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external_port,
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} => gateway
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.add_port(
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PortMappingProtocol::TCP,
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*external_port,
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*local_addr,
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LEASE_SECS,
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MAPPING_DESCRIPTION,
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)
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.is_ok(),
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Backend::NatPmp {
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gateway,
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internal_port,
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} => nat_pmp::map_tcp(
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*gateway,
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*internal_port,
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port,
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LEASE_SECS,
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NATPMP_ATTEMPTS,
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)
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.is_ok(),
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}
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}
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fn remove(backend: &Backend) {
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match backend {
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Backend::Upnp {
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gateway,
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external_port,
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..
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} => {
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let _ =
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gateway.remove_port(PortMappingProtocol::TCP, *external_port);
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}
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Backend::NatPmp {
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gateway,
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internal_port,
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} => {
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let _ = nat_pmp::unmap_tcp(*gateway, *internal_port, 2);
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}
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}
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}
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/// Sleep for `dur`, checking `stop` every 500ms. Returns `true` if `stop` was
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/// signalled (so the caller should exit promptly).
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fn sleep_until(dur: Duration, stop: &AtomicBool) -> bool {
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let deadline = Instant::now() + dur;
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while Instant::now() < deadline {
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if stop.load(Ordering::SeqCst) {
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return true;
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}
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thread::sleep(Duration::from_millis(500));
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}
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stop.load(Ordering::SeqCst)
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}
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/// The LAN IP of the interface that routes to the internet, found by asking the
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/// OS which local address a UDP socket would use to reach a public address. No
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/// packets are sent (UDP `connect` only sets the default route).
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fn local_lan_ip() -> Option<IpAddr> {
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let socket = UdpSocket::bind((Ipv4Addr::UNSPECIFIED, 0)).ok()?;
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socket.connect((Ipv4Addr::new(8, 8, 8, 8), 80)).ok()?;
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let ip = socket.local_addr().ok()?.ip();
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// A loopback/unspecified address can't be a forward target.
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if ip.is_loopback() || ip.is_unspecified() {
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None
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} else {
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Some(ip)
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}
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}
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fn info(message: &str) {
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logger::log(LogLevel::Info, &format!("[port-mapping] {message}"));
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}
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fn warn(message: &str) {
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logger::log(LogLevel::Warn, &format!("[port-mapping] {message}"));
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}
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#[cfg(test)]
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impl PortMapper {
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/// Spawn a mapper that uses ONLY the NAT-PMP backend against an injected
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/// gateway (no UPnP, no routing-table discovery), so the full spawn → map →
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/// renew → cleanup-on-drop lifecycle can be driven against a mock gateway.
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fn spawn_natpmp_test(port: u16, gateway: SocketAddr) -> Self {
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let stop = Arc::new(AtomicBool::new(false));
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let thread_stop = stop.clone();
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let handle = thread::Builder::new()
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.name("port-mapper-test".into())
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.spawn(move || {
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if let Ok(response) = nat_pmp::map_tcp(
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gateway,
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port,
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port,
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LEASE_SECS,
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NATPMP_ATTEMPTS,
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) {
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let backend = Backend::NatPmp {
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gateway,
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internal_port: port,
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};
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manage(&backend, response.lifetime, port, &thread_stop);
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}
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})
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.ok();
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Self { stop, handle }
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use std::sync::mpsc;
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use std::time::Duration as StdDuration;
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/// A mock NAT-PMP gateway that answers every map-TCP request with the same
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/// granted values and forwards each raw request to the test.
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fn mock_gateway() -> (SocketAddr, mpsc::Receiver<Vec<u8>>) {
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let socket = UdpSocket::bind((Ipv4Addr::LOCALHOST, 0)).unwrap();
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let addr = socket.local_addr().unwrap();
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let (tx, rx) = mpsc::channel();
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thread::spawn(move || {
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let mut buf = [0u8; 64];
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// Answer many requests (initial map + cleanup unmap + any renews).
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while let Ok((n, from)) = socket.recv_from(&mut buf) {
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let request = buf[..n].to_vec();
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let internal = u16::from_be_bytes([request[4], request[5]]);
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let lifetime = u32::from_be_bytes([
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request[8],
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request[9],
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request[10],
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request[11],
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]);
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// Response: version 0, opcode 130, result 0, echo internal port
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// and grant the SAME external port + requested lifetime.
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let mut reply = vec![0u8, 130, 0, 0];
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reply.extend_from_slice(&7u32.to_be_bytes()); // epoch
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reply.extend_from_slice(&internal.to_be_bytes());
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reply.extend_from_slice(&internal.to_be_bytes());
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reply.extend_from_slice(&lifetime.to_be_bytes());
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if tx.send(request).is_err() {
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break;
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}
|
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let _ = socket.send_to(&reply, from);
|
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}
|
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});
|
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(addr, rx)
|
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}
|
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|
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#[test]
|
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fn service_maps_on_start_and_unmaps_on_drop() {
|
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let (gateway, requests) = mock_gateway();
|
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let mapper = PortMapper::spawn_natpmp_test(2234, gateway);
|
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|
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// The first request must be a map with our full requested lifetime.
|
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let map_req = requests
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.recv_timeout(StdDuration::from_secs(3))
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.expect("mapper should send an initial map request");
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assert_eq!(u16::from_be_bytes([map_req[4], map_req[5]]), 2234);
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assert_eq!(
|
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u32::from_be_bytes([
|
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map_req[8],
|
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map_req[9],
|
||||
map_req[10],
|
||||
map_req[11]
|
||||
]),
|
||||
LEASE_SECS,
|
||||
"initial map should request the full lease"
|
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);
|
||||
|
||||
// Dropping the mapper must remove the mapping (a lifetime-0 request).
|
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drop(mapper);
|
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let unmap_req = requests
|
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.recv_timeout(StdDuration::from_secs(3))
|
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.expect("dropping the mapper should send an unmap request");
|
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assert_eq!(
|
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u32::from_be_bytes([
|
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unmap_req[8],
|
||||
unmap_req[9],
|
||||
unmap_req[10],
|
||||
unmap_req[11]
|
||||
]),
|
||||
0,
|
||||
"cleanup should request lifetime 0"
|
||||
);
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,316 @@
|
||||
//! Hand-rolled NAT-PMP (RFC 6886) over `std::net::UdpSocket`, no dependencies.
|
||||
//!
|
||||
//! The gateway address is always passed in as a `SocketAddr`, so tests point it
|
||||
//! at an in-process mock gateway on `127.0.0.1`. Only [`default_gateway`] touches
|
||||
//! the OS routing table.
|
||||
|
||||
use std::io;
|
||||
use std::net::{Ipv4Addr, SocketAddr, UdpSocket};
|
||||
use std::time::Duration;
|
||||
|
||||
/// The well-known NAT-PMP gateway UDP port.
|
||||
pub const NAT_PMP_PORT: u16 = 5351;
|
||||
|
||||
const PROTO_VERSION: u8 = 0;
|
||||
const OP_MAP_TCP: u8 = 2;
|
||||
const RESPONSE_FLAG: u8 = 128; // response opcode == request opcode + 128
|
||||
/// RFC-recommended mapping lifetime (2 hours).
|
||||
pub const RECOMMENDED_LIFETIME: u32 = 7200;
|
||||
|
||||
#[derive(Debug)]
|
||||
pub enum NatPmpError {
|
||||
Io(io::Error),
|
||||
ShortResponse,
|
||||
BadVersion(u8),
|
||||
BadOpcode(u8),
|
||||
/// A non-zero RFC 6886 result code (1..=5).
|
||||
ResultCode(u16),
|
||||
/// Every retransmission timed out.
|
||||
NoResponse,
|
||||
}
|
||||
|
||||
impl std::fmt::Display for NatPmpError {
|
||||
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
|
||||
match self {
|
||||
Self::Io(e) => write!(f, "network error: {e}"),
|
||||
Self::ShortResponse => write!(f, "truncated gateway response"),
|
||||
Self::BadVersion(v) => write!(f, "unexpected version {v}"),
|
||||
Self::BadOpcode(o) => write!(f, "unexpected opcode {o}"),
|
||||
Self::ResultCode(c) => write!(f, "gateway result code {c}"),
|
||||
Self::NoResponse => write!(f, "no response from gateway"),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl From<io::Error> for NatPmpError {
|
||||
fn from(e: io::Error) -> Self {
|
||||
Self::Io(e)
|
||||
}
|
||||
}
|
||||
|
||||
/// A successful TCP mapping. The gateway may grant a different external port or
|
||||
/// a shorter lifetime than requested, so callers must use these values.
|
||||
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
|
||||
pub struct MapResponse {
|
||||
/// Seconds since the gateway's port table was initialised (reboot detector).
|
||||
pub epoch: u32,
|
||||
pub internal_port: u16,
|
||||
pub external_port: u16,
|
||||
pub lifetime: u32,
|
||||
}
|
||||
|
||||
/// Request (or, with `lifetime == 0`, remove) a TCP port mapping from the
|
||||
/// NAT-PMP gateway at `gateway`. `attempts` bounds the retransmissions; RFC 6886
|
||||
/// allows up to 9 (~64s), but an interactive tool should pass a smaller number
|
||||
/// so a non-NAT-PMP router doesn't stall for a minute.
|
||||
///
|
||||
/// # Errors
|
||||
/// Returns a [`NatPmpError`] on I/O failure, a malformed/short reply, a non-zero
|
||||
/// gateway result code, or if no reply arrives within `attempts` retransmits.
|
||||
pub fn map_tcp(
|
||||
gateway: SocketAddr,
|
||||
internal_port: u16,
|
||||
suggested_external: u16,
|
||||
lifetime: u32,
|
||||
attempts: u32,
|
||||
) -> Result<MapResponse, NatPmpError> {
|
||||
let mut request = Vec::with_capacity(12);
|
||||
request.push(PROTO_VERSION);
|
||||
request.push(OP_MAP_TCP);
|
||||
request.extend_from_slice(&[0, 0]); // reserved
|
||||
request.extend_from_slice(&internal_port.to_be_bytes());
|
||||
request.extend_from_slice(&suggested_external.to_be_bytes());
|
||||
request.extend_from_slice(&lifetime.to_be_bytes());
|
||||
|
||||
let response = transact(gateway, &request, OP_MAP_TCP, attempts)?;
|
||||
if response.len() < 16 {
|
||||
return Err(NatPmpError::ShortResponse);
|
||||
}
|
||||
Ok(MapResponse {
|
||||
epoch: u32::from_be_bytes([
|
||||
response[4],
|
||||
response[5],
|
||||
response[6],
|
||||
response[7],
|
||||
]),
|
||||
internal_port: u16::from_be_bytes([response[8], response[9]]),
|
||||
external_port: u16::from_be_bytes([response[10], response[11]]),
|
||||
lifetime: u32::from_be_bytes([
|
||||
response[12],
|
||||
response[13],
|
||||
response[14],
|
||||
response[15],
|
||||
]),
|
||||
})
|
||||
}
|
||||
|
||||
/// Remove a TCP mapping for `internal_port` (external port 0, lifetime 0).
|
||||
///
|
||||
/// # Errors
|
||||
/// As [`map_tcp`].
|
||||
pub fn unmap_tcp(
|
||||
gateway: SocketAddr,
|
||||
internal_port: u16,
|
||||
attempts: u32,
|
||||
) -> Result<(), NatPmpError> {
|
||||
map_tcp(gateway, internal_port, 0, 0, attempts).map(|_| ())
|
||||
}
|
||||
|
||||
/// Send `request` to `gateway` and return the validated response body, retrying
|
||||
/// with RFC 6886's 250ms exponential backoff up to `attempts` times.
|
||||
fn transact(
|
||||
gateway: SocketAddr,
|
||||
request: &[u8],
|
||||
expected_op: u8,
|
||||
attempts: u32,
|
||||
) -> Result<Vec<u8>, NatPmpError> {
|
||||
let socket = UdpSocket::bind((Ipv4Addr::UNSPECIFIED, 0))?;
|
||||
socket.connect(gateway)?;
|
||||
|
||||
let mut timeout = Duration::from_millis(250);
|
||||
let mut buf = [0u8; 32];
|
||||
for _ in 0..attempts.max(1) {
|
||||
socket.send(request)?;
|
||||
socket.set_read_timeout(Some(timeout))?;
|
||||
match socket.recv(&mut buf) {
|
||||
Ok(n) => {
|
||||
let response = &buf[..n];
|
||||
if response.len() < 4 {
|
||||
return Err(NatPmpError::ShortResponse);
|
||||
}
|
||||
if response[0] != PROTO_VERSION {
|
||||
return Err(NatPmpError::BadVersion(response[0]));
|
||||
}
|
||||
if response[1] != expected_op + RESPONSE_FLAG {
|
||||
return Err(NatPmpError::BadOpcode(response[1]));
|
||||
}
|
||||
let result = u16::from_be_bytes([response[2], response[3]]);
|
||||
if result != 0 {
|
||||
return Err(NatPmpError::ResultCode(result));
|
||||
}
|
||||
return Ok(response.to_vec());
|
||||
}
|
||||
Err(e)
|
||||
if matches!(
|
||||
e.kind(),
|
||||
io::ErrorKind::WouldBlock | io::ErrorKind::TimedOut
|
||||
) =>
|
||||
{
|
||||
timeout = timeout.saturating_mul(2);
|
||||
}
|
||||
Err(e) => return Err(NatPmpError::Io(e)),
|
||||
}
|
||||
}
|
||||
Err(NatPmpError::NoResponse)
|
||||
}
|
||||
|
||||
/// Best-effort discovery of the IPv4 default-gateway address from the OS routing
|
||||
/// table. Supports macOS and Linux; returns `None` elsewhere or on any parse
|
||||
/// failure (callers should treat NAT-PMP as unavailable then).
|
||||
#[must_use]
|
||||
pub fn default_gateway() -> Option<Ipv4Addr> {
|
||||
#[cfg(target_os = "macos")]
|
||||
{
|
||||
let out = std::process::Command::new("route")
|
||||
.args(["-n", "get", "default"])
|
||||
.output()
|
||||
.ok()?;
|
||||
let text = String::from_utf8_lossy(&out.stdout);
|
||||
for line in text.lines() {
|
||||
let line = line.trim();
|
||||
if let Some(rest) = line.strip_prefix("gateway:") {
|
||||
return rest.trim().parse().ok();
|
||||
}
|
||||
}
|
||||
None
|
||||
}
|
||||
#[cfg(target_os = "linux")]
|
||||
{
|
||||
// /proc/net/route: tab-separated; the default route has Destination
|
||||
// 00000000, and Gateway is a little-endian hex u32.
|
||||
let text = std::fs::read_to_string("/proc/net/route").ok()?;
|
||||
for line in text.lines().skip(1) {
|
||||
let mut fields = line.split_whitespace();
|
||||
let _iface = fields.next()?;
|
||||
let destination = fields.next()?;
|
||||
let gateway = fields.next()?;
|
||||
if destination == "00000000" {
|
||||
let raw = u32::from_str_radix(gateway, 16).ok()?;
|
||||
return Some(Ipv4Addr::from(raw.to_le_bytes()));
|
||||
}
|
||||
}
|
||||
None
|
||||
}
|
||||
#[cfg(not(any(target_os = "macos", target_os = "linux")))]
|
||||
{
|
||||
None
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod tests {
|
||||
use super::*;
|
||||
use std::sync::mpsc;
|
||||
use std::thread;
|
||||
|
||||
/// A minimal in-process NAT-PMP gateway for tests. It receives one request,
|
||||
/// hands the raw bytes back to the test, and replies with `reply`.
|
||||
fn mock_gateway(reply: Vec<u8>) -> (SocketAddr, mpsc::Receiver<Vec<u8>>) {
|
||||
let socket = UdpSocket::bind((Ipv4Addr::LOCALHOST, 0)).unwrap();
|
||||
let addr = socket.local_addr().unwrap();
|
||||
let (tx, rx) = mpsc::channel();
|
||||
thread::spawn(move || {
|
||||
let mut buf = [0u8; 64];
|
||||
if let Ok((n, from)) = socket.recv_from(&mut buf) {
|
||||
let _ = tx.send(buf[..n].to_vec());
|
||||
let _ = socket.send_to(&reply, from);
|
||||
}
|
||||
});
|
||||
(addr, rx)
|
||||
}
|
||||
|
||||
fn map_reply(
|
||||
result: u16,
|
||||
internal: u16,
|
||||
external: u16,
|
||||
lifetime: u32,
|
||||
) -> Vec<u8> {
|
||||
let mut r = vec![PROTO_VERSION, OP_MAP_TCP + RESPONSE_FLAG];
|
||||
r.extend_from_slice(&result.to_be_bytes());
|
||||
r.extend_from_slice(&123u32.to_be_bytes()); // epoch
|
||||
r.extend_from_slice(&internal.to_be_bytes());
|
||||
r.extend_from_slice(&external.to_be_bytes());
|
||||
r.extend_from_slice(&lifetime.to_be_bytes());
|
||||
r
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn map_tcp_sends_correct_request_and_parses_response() {
|
||||
// Gateway grants a DIFFERENT external port and a SHORTER lease than asked.
|
||||
let (gateway, requests) = mock_gateway(map_reply(0, 2234, 40000, 3600));
|
||||
let resp = map_tcp(gateway, 2234, 2234, 7200, 3)
|
||||
.expect("mapping should succeed");
|
||||
|
||||
// The request bytes must match the RFC 6886 map-TCP layout.
|
||||
let req = requests.recv().unwrap();
|
||||
assert_eq!(req.len(), 12);
|
||||
assert_eq!(req[0], 0, "version");
|
||||
assert_eq!(req[1], 2, "opcode TCP");
|
||||
assert_eq!(&req[2..4], &[0, 0], "reserved");
|
||||
assert_eq!(u16::from_be_bytes([req[4], req[5]]), 2234, "internal port");
|
||||
assert_eq!(
|
||||
u16::from_be_bytes([req[6], req[7]]),
|
||||
2234,
|
||||
"suggested external"
|
||||
);
|
||||
assert_eq!(
|
||||
u32::from_be_bytes([req[8], req[9], req[10], req[11]]),
|
||||
7200,
|
||||
"lifetime"
|
||||
);
|
||||
|
||||
// The response's granted values (not the requested ones) are returned.
|
||||
assert_eq!(resp.external_port, 40000);
|
||||
assert_eq!(resp.lifetime, 3600);
|
||||
assert_eq!(resp.internal_port, 2234);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn map_tcp_surfaces_gateway_result_code() {
|
||||
// Result code 2 = "not authorized/refused" per RFC 6886.
|
||||
let (gateway, _req) = mock_gateway(map_reply(2, 2234, 0, 0));
|
||||
match map_tcp(gateway, 2234, 2234, 7200, 3) {
|
||||
Err(NatPmpError::ResultCode(2)) => {}
|
||||
other => panic!("expected ResultCode(2), got {other:?}"),
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn map_tcp_times_out_when_gateway_is_silent() {
|
||||
// Bind a socket but never reply: the mapper must give up, not hang.
|
||||
let dead = UdpSocket::bind((Ipv4Addr::LOCALHOST, 0)).unwrap();
|
||||
let addr = dead.local_addr().unwrap();
|
||||
drop(dead); // nothing listening now
|
||||
match map_tcp(addr, 2234, 2234, 7200, 2) {
|
||||
Err(NatPmpError::NoResponse | NatPmpError::Io(_)) => {}
|
||||
other => panic!("expected timeout/io error, got {other:?}"),
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn unmap_sends_zero_lifetime_and_port() {
|
||||
let (gateway, requests) = mock_gateway(map_reply(0, 2234, 0, 0));
|
||||
unmap_tcp(gateway, 2234, 3).expect("unmap should succeed");
|
||||
let req = requests.recv().unwrap();
|
||||
assert_eq!(
|
||||
u16::from_be_bytes([req[6], req[7]]),
|
||||
0,
|
||||
"external port 0 to delete"
|
||||
);
|
||||
assert_eq!(
|
||||
u32::from_be_bytes([req[8], req[9], req[10], req[11]]),
|
||||
0,
|
||||
"lifetime 0 to delete"
|
||||
);
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user