Listen on tcp and websocket transports

- Listen on both tcp and websockets as default
- Listening addresses in config as array
- Configure fallback transport using `or_transport` - if listening on a given address fails on WS, we fall back to TCP.

swap/Cargo.toml

@@ -27,7 +27,7 @@ directories-next = "2"
 ecdsa_fun = { git = "https://github.com/LLFourn/secp256kfun", features = ["libsecp_compat", "serde"] }
 futures = { version = "0.3", default-features = false }
 itertools = "0.10"
-libp2p = { version = "0.36", default-features = false, features = ["tcp-tokio", "yamux", "mplex", "dns-tokio", "noise", "request-response"] }
+libp2p = { version = "0.36", default-features = false, features = ["tcp-tokio", "yamux", "mplex", "dns-tokio", "noise", "request-response", "websocket"] }
 libp2p-async-await = { git = "https://github.com/comit-network/rust-libp2p-async-await" }
 miniscript = { version = "5", features = ["serde"] }
 monero = { version = "0.11", features = ["serde_support"] }

swap/src/asb/config.rs

@@ -11,7 +11,8 @@ use std::path::{Path, PathBuf};
 use tracing::info;
 use url::Url;
 
-const DEFAULT_LISTEN_ADDRESS: &str = "/ip4/0.0.0.0/tcp/9939";
+const DEFAULT_LISTEN_ADDRESS_TCP: &str = "/ip4/0.0.0.0/tcp/9939";
+const DEFAULT_LISTEN_ADDRESS_WS: &str = "/ip4/0.0.0.0/tcp/9940/ws";
 const DEFAULT_ELECTRUM_RPC_URL: &str = "ssl://electrum.blockstream.info:60002";
 const DEFAULT_MONERO_WALLET_RPC_TESTNET_URL: &str = "http://127.0.0.1:38083/json_rpc";
 
@@ -45,7 +46,7 @@ pub struct Data {
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 #[serde(deny_unknown_fields)]
 pub struct Network {
-    pub listen: Multiaddr,
+    pub listen: Vec<Multiaddr>,
 }
 
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
@@ -112,11 +113,14 @@ pub fn query_user_for_initial_testnet_config() -> Result<Config> {
         .interact_text()?;
     let data_dir = data_dir.as_str().parse()?;
 
-    let listen_address = Input::with_theme(&ColorfulTheme::default())
-        .with_prompt("Enter multiaddress on which asb should list for peer-to-peer communications or hit return to use default")
-        .default(DEFAULT_LISTEN_ADDRESS.to_owned())
+    let listen_addresses = Input::with_theme(&ColorfulTheme::default())
+        .with_prompt("Enter multiaddresses (comma separated) on which asb should list for peer-to-peer communications or hit return to use default")
+        .default( format!("{},{}", DEFAULT_LISTEN_ADDRESS_TCP, DEFAULT_LISTEN_ADDRESS_WS))
         .interact_text()?;
-    let listen_address = listen_address.as_str().parse()?;
+    let listen_addresses = listen_addresses
+        .split(',')
+        .map(|str| str.parse())
+        .collect::<Result<Vec<Multiaddr>, _>>()?;
 
     let electrum_rpc_url: String = Input::with_theme(&ColorfulTheme::default())
         .with_prompt("Enter Electrum RPC URL or hit return to use default")
@@ -134,7 +138,7 @@ pub fn query_user_for_initial_testnet_config() -> Result<Config> {
     Ok(Config {
         data: Data { dir: data_dir },
         network: Network {
-            listen: listen_address,
+            listen: listen_addresses,
         },
         bitcoin: Bitcoin { electrum_rpc_url },
         monero: Monero {
@@ -162,7 +166,10 @@ mod tests {
                 electrum_rpc_url: Url::from_str(DEFAULT_ELECTRUM_RPC_URL).unwrap(),
             },
             network: Network {
-                listen: DEFAULT_LISTEN_ADDRESS.parse().unwrap(),
+                listen: vec![
+                    DEFAULT_LISTEN_ADDRESS_TCP.parse().unwrap(),
+                    DEFAULT_LISTEN_ADDRESS_WS.parse().unwrap(),
+                ],
             },
 
             monero: Monero {

swap/src/bin/asb.rs

@@ -98,8 +98,11 @@ async fn main() -> Result<()> {
             let kraken_price_updates = kraken::connect()?;
 
             let mut swarm = swarm::alice(&seed)?;
-            Swarm::listen_on(&mut swarm, config.network.listen)
-                .context("Failed to listen network interface")?;
+
+            for listen in config.network.listen {
+                Swarm::listen_on(&mut swarm, listen.clone())
+                    .with_context(|| format!("Failed to listen on network interface {}", listen))?;
+            }
 
             let (event_loop, mut swap_receiver) = EventLoop::new(
                 swarm,

swap/src/network/transport.rs

@@ -6,11 +6,13 @@ use libp2p::core::{identity, Transport};
 use libp2p::dns::TokioDnsConfig;
 use libp2p::mplex::MplexConfig;
 use libp2p::noise::{self, NoiseConfig, X25519Spec};
+use libp2p::websocket::WsConfig;
 use libp2p::{yamux, PeerId};
 use std::time::Duration;
 
 /// Builds a libp2p transport with the following features:
 /// - TcpConnection
+/// - WebSocketConnection
 /// - DNS name resolution
 /// - authentication via noise
 /// - multiplexing via yamux or mplex
@@ -22,8 +24,10 @@ pub fn build(id_keys: &identity::Keypair) -> Result<SwapTransport> {
 
     let tcp = TokioTcpConfig::new().nodelay(true);
     let dns = TokioDnsConfig::system(tcp)?;
+    let websocket = WsConfig::new(dns.clone());
 
-    let transport = dns
+    let transport = websocket
+        .or_transport(dns)
         .upgrade(Version::V1)
         .authenticate(noise)
         .multiplex(SelectUpgrade::new(