feat(quic): implement hole punching

Implement `Transport::dial_as_listener` for QUIC as specified by the [DCUtR spec](https://github.com/libp2p/specs/blob/master/relay/DCUtR.md).

To facilitate hole punching in QUIC, one side needs to send random UDP packets to establish a mapping in the routing table of the NAT device. If successful, our listener will emit a new inbound connection. This connection needs to then be sent to the dialing task. We achieve this by storing a `HashMap` of hole punch attempts indexed by the remote's `SocketAddr`. A matching incoming connection is then sent via a oneshot channel to the dialing task which continues with upgrading the connection.

Related #2883.

Pull-Request: #3964.

examples/dcutr/Cargo.toml

@@ -11,4 +11,5 @@ env_logger = "0.10.0"
 futures = "0.3.28"
 futures-timer = "3.0"
 libp2p = { path = "../../libp2p", features = ["async-std", "dns", "dcutr", "identify", "macros", "noise", "ping", "relay", "rendezvous", "tcp", "tokio", "yamux"] }
+libp2p-quic = { path = "../../transports/quic", features = ["async-std"] }
 log = "0.4"

examples/dcutr/src/main.rs

@@ -23,13 +23,14 @@
 use clap::Parser;
 use futures::{
     executor::{block_on, ThreadPool},
-    future::FutureExt,
+    future::{Either, FutureExt},
     stream::StreamExt,
 };
 use libp2p::{
     core::{
         multiaddr::{Multiaddr, Protocol},
-        transport::{OrTransport, Transport},
+        muxing::StreamMuxerBox,
+        transport::Transport,
         upgrade,
     },
     dcutr,
@@ -38,9 +39,9 @@ use libp2p::{
     swarm::{NetworkBehaviour, SwarmBuilder, SwarmEvent},
     tcp, yamux, PeerId,
 };
+use libp2p_quic as quic;
 use log::info;
 use std::error::Error;
-use std::net::Ipv4Addr;
 use std::str::FromStr;
 
 #[derive(Debug, Parser)]
@@ -91,19 +92,26 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     let (relay_transport, client) = relay::client::new(local_peer_id);
 
-    let transport = OrTransport::new(
-        relay_transport,
-        block_on(DnsConfig::system(tcp::async_io::Transport::new(
-            tcp::Config::default().port_reuse(true),
-        )))
-        .unwrap(),
-    )
-    .upgrade(upgrade::Version::V1Lazy)
-    .authenticate(
-        noise::Config::new(&local_key).expect("Signing libp2p-noise static DH keypair failed."),
-    )
-    .multiplex(yamux::Config::default())
-    .boxed();
+    let transport = {
+        let relay_tcp_quic_transport = relay_transport
+            .or_transport(tcp::async_io::Transport::new(
+                tcp::Config::default().port_reuse(true),
+            ))
+            .upgrade(upgrade::Version::V1)
+            .authenticate(noise::Config::new(&local_key).unwrap())
+            .multiplex(yamux::Config::default())
+            .or_transport(quic::async_std::Transport::new(quic::Config::new(
+                &local_key,
+            )));
+
+        block_on(DnsConfig::system(relay_tcp_quic_transport))
+            .unwrap()
+            .map(|either_output, _| match either_output {
+                Either::Left((peer_id, muxer)) => (peer_id, StreamMuxerBox::new(muxer)),
+                Either::Right((peer_id, muxer)) => (peer_id, StreamMuxerBox::new(muxer)),
+            })
+            .boxed()
+    };
 
     #[derive(NetworkBehaviour)]
     #[behaviour(to_swarm = "Event")]
@@ -164,11 +172,10 @@ fn main() -> Result<(), Box<dyn Error>> {
     .build();
 
     swarm
-        .listen_on(
-            Multiaddr::empty()
-                .with("0.0.0.0".parse::<Ipv4Addr>().unwrap().into())
-                .with(Protocol::Tcp(0)),
-        )
+        .listen_on("/ip4/0.0.0.0/udp/0/quic-v1".parse().unwrap())
+        .unwrap();
+    swarm
+        .listen_on("/ip4/0.0.0.0/tcp/0".parse().unwrap())
         .unwrap();
 
     // Wait to listen on all interfaces.

examples/relay-server/Cargo.toml

@@ -12,3 +12,4 @@ async-trait = "0.1"
 env_logger = "0.10.0"
 futures = "0.3.28"
 libp2p = { path = "../../libp2p", features = ["async-std", "noise", "macros", "ping", "tcp", "identify", "yamux", "relay"] }
+libp2p-quic = { path = "../../transports/quic", features = ["async-std"] }

examples/relay-server/src/main.rs

@@ -22,10 +22,11 @@
 #![doc = include_str!("../README.md")]
 
 use clap::Parser;
-use futures::executor::block_on;
 use futures::stream::StreamExt;
+use futures::{executor::block_on, future::Either};
 use libp2p::{
     core::multiaddr::Protocol,
+    core::muxing::StreamMuxerBox,
     core::upgrade,
     core::{Multiaddr, Transport},
     identify, identity,
@@ -34,6 +35,7 @@ use libp2p::{
     swarm::{NetworkBehaviour, SwarmBuilder, SwarmEvent},
     tcp,
 };
+use libp2p_quic as quic;
 use std::error::Error;
 use std::net::{Ipv4Addr, Ipv6Addr};
 
@@ -50,12 +52,21 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     let tcp_transport = tcp::async_io::Transport::default();
 
-    let transport = tcp_transport
+    let tcp_transport = tcp_transport
         .upgrade(upgrade::Version::V1Lazy)
         .authenticate(
             noise::Config::new(&local_key).expect("Signing libp2p-noise static DH keypair failed."),
         )
-        .multiplex(libp2p::yamux::Config::default())
+        .multiplex(libp2p::yamux::Config::default());
+
+    let quic_transport = quic::async_std::Transport::new(quic::Config::new(&local_key));
+
+    let transport = quic_transport
+        .or_transport(tcp_transport)
+        .map(|either_output, _| match either_output {
+            Either::Left((peer_id, muxer)) => (peer_id, StreamMuxerBox::new(muxer)),
+            Either::Right((peer_id, muxer)) => (peer_id, StreamMuxerBox::new(muxer)),
+        })
         .boxed();
 
     let behaviour = Behaviour {
@@ -70,13 +81,22 @@ fn main() -> Result<(), Box<dyn Error>> {
     let mut swarm = SwarmBuilder::without_executor(transport, behaviour, local_peer_id).build();
 
     // Listen on all interfaces
-    let listen_addr = Multiaddr::empty()
+    let listen_addr_tcp = Multiaddr::empty()
         .with(match opt.use_ipv6 {
             Some(true) => Protocol::from(Ipv6Addr::UNSPECIFIED),
             _ => Protocol::from(Ipv4Addr::UNSPECIFIED),
         })
         .with(Protocol::Tcp(opt.port));
-    swarm.listen_on(listen_addr)?;
+    swarm.listen_on(listen_addr_tcp)?;
+
+    let listen_addr_quic = Multiaddr::empty()
+        .with(match opt.use_ipv6 {
+            Some(true) => Protocol::from(Ipv6Addr::UNSPECIFIED),
+            _ => Protocol::from(Ipv4Addr::UNSPECIFIED),
+        })
+        .with(Protocol::Udp(opt.port))
+        .with(Protocol::QuicV1);
+    swarm.listen_on(listen_addr_quic)?;
 
     block_on(async {
         loop {