fix(quic): allow listening on ipv4 and ipv6 separately

Resolves #4165.

Pull-Request: #4289.

Cargo.toml

@@ -85,7 +85,7 @@ libp2p-perf = { version = "0.2.0", path = "protocols/perf" }
 libp2p-ping = { version = "0.43.0", path = "protocols/ping" }
 libp2p-plaintext = { version = "0.40.0", path = "transports/plaintext" }
 libp2p-pnet = { version = "0.23.0", path = "transports/pnet" }
-libp2p-quic = { version = "0.9.0-alpha", path = "transports/quic" }
+libp2p-quic = { version = "0.9.1-alpha", path = "transports/quic" }
 libp2p-relay = { version = "0.16.1", path = "protocols/relay" }
 libp2p-rendezvous = { version = "0.13.0", path = "protocols/rendezvous" }
 libp2p-request-response = { version = "0.25.1", path = "protocols/request-response" }

transports/quic/CHANGELOG.md

@@ -1,3 +1,10 @@
+## 0.9.1-alpha - unreleased
+
+- Allow listening on ipv4 and ipv6 separately.
+  See [PR 4289].
+
+[PR 4289]: https://github.com/libp2p/rust-libp2p/pull/4289
+
 ## 0.9.0-alpha
 
 - Use `quinn` instead of `quinn-proto`.

transports/quic/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libp2p-quic"
-version = "0.9.0-alpha"
+version = "0.9.1-alpha"
 authors = ["Parity Technologies <[email protected]>"]
 edition = "2021"
 rust-version = { workspace = true }
@@ -24,6 +24,7 @@ rand = "0.8.5"
 rustls = { version = "0.21.2", default-features = false }
 thiserror = "1.0.44"
 tokio = { version = "1.29.1", default-features = false, features = ["net", "rt", "time"], optional = true }
+socket2 = "0.5.3"
 
 [features]
 tokio = ["dep:tokio", "if-watch/tokio", "quinn/runtime-tokio"]

transports/quic/src/transport.rs

@@ -37,12 +37,13 @@ use libp2p_core::{
     Transport,
 };
 use libp2p_identity::PeerId;
+use socket2::{Domain, Socket, Type};
 use std::collections::hash_map::{DefaultHasher, Entry};
 use std::collections::HashMap;
-use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, UdpSocket};
 use std::time::Duration;
+use std::{fmt, io};
 use std::{
     net::SocketAddr,
     pin::Pin,
@@ -172,6 +173,21 @@ impl<P: Provider> GenTransport<P> {
             }
         }
     }
+
+    fn create_socket(&self, socket_addr: SocketAddr) -> io::Result<UdpSocket> {
+        let socket = Socket::new(
+            Domain::for_address(socket_addr),
+            Type::DGRAM,
+            Some(socket2::Protocol::UDP),
+        )?;
+        if socket_addr.is_ipv6() {
+            socket.set_only_v6(true)?;
+        }
+
+        socket.bind(&socket_addr.into())?;
+
+        Ok(socket.into())
+    }
 }
 
 impl<P: Provider> Transport for GenTransport<P> {
@@ -188,7 +204,8 @@ impl<P: Provider> Transport for GenTransport<P> {
         let (socket_addr, version, _peer_id) = self.remote_multiaddr_to_socketaddr(addr, false)?;
         let endpoint_config = self.quinn_config.endpoint_config.clone();
         let server_config = self.quinn_config.server_config.clone();
-        let socket = UdpSocket::bind(socket_addr).map_err(Self::Error::from)?;
+        let socket = self.create_socket(socket_addr).map_err(Self::Error::from)?;
+
         let socket_c = socket.try_clone().map_err(Self::Error::from)?;
         let endpoint = Self::new_endpoint(endpoint_config, Some(server_config), socket)?;
         let listener = Listener::new(
@@ -888,4 +905,25 @@ mod test {
             .unwrap();
         assert!(!transport.dialer.contains_key(&SocketFamily::Ipv4));
     }
+
+    #[cfg(feature = "tokio")]
+    #[tokio::test]
+    async fn test_listens_ipv4_ipv6_separately() {
+        let keypair = libp2p_identity::Keypair::generate_ed25519();
+        let config = Config::new(&keypair);
+        let mut transport = crate::tokio::Transport::new(config);
+
+        transport
+            .listen_on(
+                ListenerId::next(),
+                "/ip4/0.0.0.0/udp/4001/quic-v1".parse().unwrap(),
+            )
+            .unwrap();
+        transport
+            .listen_on(
+                ListenerId::next(),
+                "/ip6/::/udp/4001/quic-v1".parse().unwrap(),
+            )
+            .unwrap();
+    }
 }