Set IPV6_ONLY on IPv6 sockets

Fixes #9

Cargo.toml

@@ -19,7 +19,7 @@ coarsetime = "0.1.11"
 daemonize-simple = "0.1.2"
 derivative = "1.0.3"
 dnsstamps = "0.1.2"
-env_logger = { version="0.7.0", default-features = false, features = ["humantime"]}
+env_logger = { version="0.7.1", default-features = false, features = ["humantime"]}
 failure = "0.1.6"
 futures-preview = { version = "=0.3.0-alpha.19", features = ["async-await"] }
 jemallocator = "0.3.2"

src/main.rs

@@ -237,11 +237,14 @@ async fn tls_proxy(
         Some(tls_upstream_addr) => tls_upstream_addr,
     };
     let std_socket = match globals.external_addr {
-        SocketAddr::V4(_) => net2::TcpBuilder::new_v4(),
-        SocketAddr::V6(_) => net2::TcpBuilder::new_v6(),
-    }?
-    .bind(&globals.external_addr)?
-    .to_tcp_stream()?;
+        SocketAddr::V4(_) => net2::TcpBuilder::new_v4()?
+            .bind(&globals.external_addr)?
+            .to_tcp_stream()?,
+        SocketAddr::V6(_) => net2::TcpBuilder::new_v6()?
+            .only_v6(true)?
+            .bind(&globals.external_addr)?
+            .to_tcp_stream()?,
+    };
     let mut ext_socket =
         TcpStream::connect_std(std_socket, tls_upstream_addr, &Default::default()).await?;
     let (mut erh, mut ewh) = ext_socket.split();
@@ -384,15 +387,29 @@ async fn start(
 
 fn bind_listeners(
     listen_addrs: &[SocketAddr],
-    runtime: Arc<Runtime>,
 ) -> Result<Vec<(TcpListener, std::net::UdpSocket)>, Error> {
     let mut sockets = Vec::with_capacity(listen_addrs.len());
     for listen_addr in listen_addrs {
-        let tcp_listener = match runtime.block_on(TcpListener::bind(&listen_addr)) {
+        let std_socket = match listen_addr {
+            SocketAddr::V4(_) => net2::TcpBuilder::new_v4()?
+                .bind(&listen_addr)?
+                .to_tcp_listener()?,
+            SocketAddr::V6(_) => net2::TcpBuilder::new_v6()?
+                .only_v6(true)?
+                .bind(&listen_addr)?
+                .to_tcp_listener()?,
+        };
+        let tcp_listener = match TcpListener::from_std(std_socket, &Default::default()) {
             Ok(tcp_listener) => tcp_listener,
             Err(e) => bail!(format_err!("{}/TCP: {}", listen_addr, e)),
         };
-        let udp_socket = match std::net::UdpSocket::bind(&listen_addr) {
+        let std_socket = match listen_addr {
+            SocketAddr::V4(_) => net2::UdpBuilder::new_v4()?.bind(&listen_addr),
+            SocketAddr::V6(_) => net2::UdpBuilder::new_v6()?
+                .only_v6(true)?
+                .bind(&listen_addr),
+        };
+        let udp_socket = match std_socket {
             Ok(udp_socket) => udp_socket,
             Err(e) => bail!(format_err!("{}/UDP: {}", listen_addr, e)),
         };
@@ -486,7 +503,7 @@ fn main() -> Result<(), Error> {
     let runtime = Arc::new(runtime_builder.build()?);
 
     let listen_addrs: Vec<_> = config.listen_addrs.iter().map(|x| x.local).collect();
-    let listeners = bind_listeners(&listen_addrs, runtime.clone())
+    let listeners = bind_listeners(&listen_addrs)
         .map_err(|e| {
             error!("Unable to listen to the requested IPs and ports: [{}]", e);
             std::process::exit(1);

src/metrics.rs

@@ -10,6 +10,7 @@ use hyper::service::service_fn;
 use hyper::{Body, Request, Response, StatusCode};
 use prometheus::{self, Encoder, TextEncoder};
 use std::mem;
+use std::net::SocketAddr;
 use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::Arc;
 use tokio::net::TcpListener;
@@ -52,7 +53,16 @@ pub async fn prometheus_service(
     runtime: Arc<Runtime>,
 ) -> Result<(), Error> {
     let path = Arc::new(metrics_config.path);
-    let mut stream = TcpListener::bind(metrics_config.listen_addr).await?;
+    let std_socket = match metrics_config.listen_addr {
+        SocketAddr::V4(_) => net2::TcpBuilder::new_v4()?
+            .bind(&metrics_config.listen_addr)?
+            .to_tcp_listener()?,
+        SocketAddr::V6(_) => net2::TcpBuilder::new_v6()?
+            .only_v6(true)?
+            .bind(&metrics_config.listen_addr)?
+            .to_tcp_listener()?,
+    };
+    let mut stream = TcpListener::from_std(std_socket, &Default::default())?;
     let concurrent_connections = Arc::new(AtomicU32::new(0));
     loop {
         let (client, _client_addr) = stream.accept().await?;

src/resolver.rs

@@ -18,7 +18,13 @@ pub async fn resolve_udp(
     tid: u16,
     has_cached_response: bool,
 ) -> Result<Vec<u8>, Error> {
-    let mut ext_socket = UdpSocket::bind(&globals.external_addr).await?;
+    let std_socket = match globals.external_addr {
+        SocketAddr::V4(_) => net2::UdpBuilder::new_v4()?.bind(&globals.external_addr)?,
+        SocketAddr::V6(_) => net2::UdpBuilder::new_v6()?
+            .only_v6(true)?
+            .bind(&globals.external_addr)?,
+    };
+    let mut ext_socket = UdpSocket::from_std(std_socket, &Default::default())?;
     ext_socket.connect(&globals.upstream_addr).await?;
     dns::set_edns_max_payload_size(&mut packet, DNS_MAX_PACKET_SIZE as u16)?;
     let mut response;
@@ -60,11 +66,14 @@ pub async fn resolve_tcp(
     tid: u16,
 ) -> Result<Vec<u8>, Error> {
     let std_socket = match globals.external_addr {
-        SocketAddr::V4(_) => net2::TcpBuilder::new_v4(),
-        SocketAddr::V6(_) => net2::TcpBuilder::new_v6(),
-    }?
-    .bind(&globals.external_addr)?
-    .to_tcp_stream()?;
+        SocketAddr::V4(_) => net2::TcpBuilder::new_v4()?
+            .bind(&globals.external_addr)?
+            .to_tcp_stream()?,
+        SocketAddr::V6(_) => net2::TcpBuilder::new_v6()?
+            .only_v6(true)?
+            .bind(&globals.external_addr)?
+            .to_tcp_stream()?,
+    };
     let mut ext_socket =
         TcpStream::connect_std(std_socket, &globals.upstream_addr, &Default::default()).await?;
     ext_socket.set_nodelay(true)?;