Merge #1417

1417: feat(asb): allow asb to register with mulitple rendezvous nodes r=binarybaron a=delta1

implements #633  

This PR updates the ASB to be able to register with multiple rendezvous nodes. A unit test is added that checks this behaviour. I also tested it manually overnight and it repeatedly reregistered with the specified nodes.  

The config file option is left as `rendezvous_point` for backwards compatibility, but now uses the same deserialization as introduced in #1231 so that multiple addresses can be specified in a comma separated string, or as a toml array of strings.

Co-authored-by: Byron Hambly <bhambly@blockstream.com>

CHANGELOG.md

@@ -9,7 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
-- Minimum Supported Rust Version (MSRV) bumped to 1.63
+- Minimum Supported Rust Version (MSRV) bumped to 1.67
+- ASB can now register with multiple rendezvous nodes. The `rendezvous_point` option in `config.toml` can be a string with comma separated addresses, or a toml array of address strings.
 
 ## [0.12.1] - 2023-01-09
 

docs/asb/README.md

@@ -42,13 +42,16 @@ Since the ASB is a long running task we specify the person running an ASB as ser
 The ASB daemon supports the libp2p [rendezvous-protocol](https://github.com/libp2p/specs/tree/master/rendezvous).
 Usage of the rendezvous functionality is entirely optional.
 
-You can configure a rendezvous point in the `[network]` section of your config file.
+You can configure one or more rendezvous point in the `[network]` section of your config file.
 For the registration to be successful, you also need to configure the externally reachable addresses within the `[network]` section.
 For example:
 
 ```toml
 [network]
-rendezvous_point = "/dns4/discover.unstoppableswap.net/tcp/8888/p2p/12D3KooWA6cnqJpVnreBVnoro8midDL9Lpzmg8oJPoAGi7YYaamE"
+rendezvous_point = [
+   "/dns4/discover.unstoppableswap.net/tcp/8888/p2p/12D3KooWA6cnqJpVnreBVnoro8midDL9Lpzmg8oJPoAGi7YYaamE",
+   "/dns4/eratosthen.es/tcp/7798/p2p/12D3KooWAh7EXXa2ZyegzLGdjvj1W4G3EXrTGrf6trraoT1MEobs",
+]
 external_addresses = ["/dns4/example.com/tcp/9939"]
 ```
 

swap/src/asb.rs

@@ -8,6 +8,7 @@ pub mod tracing;
 
 pub use event_loop::{EventLoop, EventLoopHandle, FixedRate, KrakenRate, LatestRate};
 pub use network::behaviour::{Behaviour, OutEvent};
+pub use network::rendezvous::RendezvousNode;
 pub use network::transport;
 pub use rate::Rate;
 pub use recovery::cancel::cancel;
@@ -18,4 +19,4 @@ pub use recovery::safely_abort::safely_abort;
 pub use recovery::{cancel, refund};
 
 #[cfg(test)]
-pub use network::rendezous;
+pub use network::rendezvous;

swap/src/asb/config.rs

@@ -134,8 +134,8 @@ pub struct Data {
 pub struct Network {
     #[serde(deserialize_with = "addr_list::deserialize")]
     pub listen: Vec<Multiaddr>,
-    #[serde(default)]
-    pub rendezvous_point: Option<Multiaddr>,
+    #[serde(default, deserialize_with = "addr_list::deserialize")]
+    pub rendezvous_point: Vec<Multiaddr>,
     #[serde(default, deserialize_with = "addr_list::deserialize")]
     pub external_addresses: Vec<Multiaddr>,
 }
@@ -156,7 +156,7 @@ mod addr_list {
                 let list: Result<Vec<_>, _> = s
                     .split(',')
                     .filter(|s| !s.is_empty())
-                    .map(|s| s.parse().map_err(de::Error::custom))
+                    .map(|s| s.trim().parse().map_err(de::Error::custom))
                     .collect();
                 Ok(list?)
             }
@@ -165,7 +165,7 @@ mod addr_list {
                     .iter()
                     .map(|v| {
                         if let Value::String(s) = v {
-                            s.parse().map_err(de::Error::custom)
+                            s.trim().parse().map_err(de::Error::custom)
                         } else {
                             Err(de::Error::custom("expected a string"))
                         }
@@ -347,10 +347,27 @@ pub fn query_user_for_initial_config(testnet: bool) -> Result<Config> {
     }
     let ask_spread = Decimal::from_f64(ask_spread).context("Unable to parse spread")?;
 
-    let rendezvous_point = Input::<Multiaddr>::with_theme(&ColorfulTheme::default())
-        .with_prompt("Do you want to advertise your ASB instance with a rendezvous node? Enter an empty string if not.")
-        .allow_empty(true)
-        .interact_text()?;
+    let mut number = 1;
+    let mut done = false;
+    let mut rendezvous_points = Vec::new();
+    println!("ASB can register with multiple rendezvous nodes for discoverability. This can also be edited in the config file later.");
+    while !done {
+        let prompt = format!(
+            "Enter the address for rendezvous node ({number}). Or just hit Enter to continue."
+        );
+        let rendezvous_addr = Input::<Multiaddr>::with_theme(&ColorfulTheme::default())
+            .with_prompt(prompt)
+            .allow_empty(true)
+            .interact_text()?;
+        if rendezvous_addr.is_empty() {
+            done = true;
+        } else if rendezvous_points.contains(&rendezvous_addr) {
+            println!("That rendezvous address is already in the list.");
+        } else {
+            rendezvous_points.push(rendezvous_addr);
+            number += 1;
+        }
+    }
 
     println!();
 
@@ -358,11 +375,7 @@ pub fn query_user_for_initial_config(testnet: bool) -> Result<Config> {
         data: Data { dir: data_dir },
         network: Network {
             listen: listen_addresses,
-            rendezvous_point: if rendezvous_point.is_empty() {
-                None
-            } else {
-                Some(rendezvous_point)
-            },
+            rendezvous_point: rendezvous_points, // keeping the singular key name for backcompat
             external_addresses: vec![],
         },
         bitcoin: Bitcoin {
@@ -417,7 +430,7 @@ mod tests {
             },
             network: Network {
                 listen: vec![defaults.listen_address_tcp, defaults.listen_address_ws],
-                rendezvous_point: None,
+                rendezvous_point: vec![],
                 external_addresses: vec![],
             },
             monero: Monero {
@@ -461,7 +474,7 @@ mod tests {
             },
             network: Network {
                 listen: vec![defaults.listen_address_tcp, defaults.listen_address_ws],
-                rendezvous_point: None,
+                rendezvous_point: vec![],
                 external_addresses: vec![],
             },
             monero: Monero {
@@ -515,7 +528,7 @@ mod tests {
             },
             network: Network {
                 listen,
-                rendezvous_point: None,
+                rendezvous_point: vec![],
                 external_addresses,
             },
             monero: Monero {

swap/src/asb/event_loop.rs

@@ -253,8 +253,8 @@ where
                                 channel
                             }.boxed());
                         }
-                        SwarmEvent::Behaviour(OutEvent::Rendezvous(libp2p::rendezvous::client::Event::Registered { .. })) => {
-                            tracing::info!("Successfully registered with rendezvous node");
+                        SwarmEvent::Behaviour(OutEvent::Rendezvous(libp2p::rendezvous::client::Event::Registered { rendezvous_node, ttl, namespace })) => {
+                            tracing::info!("Successfully registered with rendezvous node: {} with namespace: {} and TTL: {:?}", rendezvous_node, namespace, ttl);
                         }
                         SwarmEvent::Behaviour(OutEvent::Rendezvous(libp2p::rendezvous::client::Event::RegisterFailed(error))) => {
                             tracing::error!("Registration with rendezvous node failed: {:?}", error);

swap/src/asb/network.rs

@@ -44,7 +44,9 @@ pub mod transport {
 }
 
 pub mod behaviour {
-    use super::*;
+    use libp2p::swarm::behaviour::toggle::Toggle;
+
+    use super::{rendezvous::RendezvousNode, *};
 
     #[allow(clippy::large_enum_variant)]
     #[derive(Debug)]
@@ -108,7 +110,7 @@ pub mod behaviour {
     where
         LR: LatestRate + Send + 'static,
     {
-        pub rendezvous: libp2p::swarm::behaviour::toggle::Toggle<rendezous::Behaviour>,
+        pub rendezvous: Toggle<rendezvous::Behaviour>,
         pub quote: quote::Behaviour,
         pub swap_setup: alice::Behaviour<LR>,
         pub transfer_proof: transfer_proof::Behaviour,
@@ -132,25 +134,22 @@ pub mod behaviour {
             resume_only: bool,
             env_config: env::Config,
             identify_params: (identity::Keypair, XmrBtcNamespace),
-            rendezvous_params: Option<(identity::Keypair, PeerId, Multiaddr, XmrBtcNamespace)>,
+            rendezvous_nodes: Vec<RendezvousNode>,
         ) -> Self {
-            let agentVersion = format!("asb/{} ({})", env!("CARGO_PKG_VERSION"), identify_params.1);
-            let protocolVersion = "/comit/xmr/btc/1.0.0".to_string();
-            let identifyConfig = IdentifyConfig::new(protocolVersion, identify_params.0.public())
-                .with_agent_version(agentVersion);
+            let (identity, namespace) = identify_params;
+            let agent_version = format!("asb/{} ({})", env!("CARGO_PKG_VERSION"), namespace);
+            let protocol_version = "/comit/xmr/btc/1.0.0".to_string();
+            let identifyConfig = IdentifyConfig::new(protocol_version, identity.public())
+                .with_agent_version(agent_version);
+
+            let behaviour = if rendezvous_nodes.is_empty() {
+                None
+            } else {
+                Some(rendezvous::Behaviour::new(identity, rendezvous_nodes))
+            };
 
             Self {
-                rendezvous: libp2p::swarm::behaviour::toggle::Toggle::from(rendezvous_params.map(
-                    |(identity, rendezvous_peer_id, rendezvous_address, namespace)| {
-                        rendezous::Behaviour::new(
-                            identity,
-                            rendezvous_peer_id,
-                            rendezvous_address,
-                            namespace,
-                            None, // use default ttl on rendezvous point
-                        )
-                    },
-                )),
+                rendezvous: Toggle::from(behaviour),
                 quote: quote::asb(),
                 swap_setup: alice::Behaviour::new(
                     min_buy,
@@ -186,13 +185,14 @@ pub mod behaviour {
     }
 }
 
-pub mod rendezous {
+pub mod rendezvous {
     use super::*;
     use libp2p::swarm::dial_opts::DialOpts;
     use libp2p::swarm::DialError;
+    use std::collections::VecDeque;
     use std::pin::Pin;
 
-    #[derive(PartialEq)]
+    #[derive(Clone, PartialEq)]
     enum ConnectionStatus {
         Disconnected,
         Dialling,
@@ -209,39 +209,59 @@ pub mod rendezous {
 
     pub struct Behaviour {
         inner: libp2p::rendezvous::client::Behaviour,
-        rendezvous_point: Multiaddr,
-        rendezvous_peer_id: PeerId,
-        namespace: XmrBtcNamespace,
-        registration_status: RegistrationStatus,
+        rendezvous_nodes: Vec<RendezvousNode>,
+        to_dial: VecDeque<PeerId>,
+    }
+
+    pub struct RendezvousNode {
+        pub address: Multiaddr,
         connection_status: ConnectionStatus,
-        registration_ttl: Option<u64>,
+        pub peer_id: PeerId,
+        registration_status: RegistrationStatus,
+        pub registration_ttl: Option<u64>,
+        pub namespace: XmrBtcNamespace,
     }
 
-    impl Behaviour {
+    impl RendezvousNode {
         pub fn new(
-            identity: identity::Keypair,
-            rendezvous_peer_id: PeerId,
-            rendezvous_address: Multiaddr,
+            address: &Multiaddr,
+            peer_id: PeerId,
             namespace: XmrBtcNamespace,
             registration_ttl: Option<u64>,
         ) -> Self {
             Self {
-                inner: libp2p::rendezvous::client::Behaviour::new(identity),
-                rendezvous_point: rendezvous_address,
-                rendezvous_peer_id,
+                address: address.to_owned(),
+                connection_status: ConnectionStatus::Disconnected,
                 namespace,
+                peer_id,
                 registration_status: RegistrationStatus::RegisterOnNextConnection,
-                connection_status: ConnectionStatus::Disconnected,
                 registration_ttl,
             }
         }
 
-        fn register(&mut self) {
-            self.inner.register(
-                self.namespace.into(),
-                self.rendezvous_peer_id,
-                self.registration_ttl,
-            );
+        fn set_connection(&mut self, status: ConnectionStatus) {
+            self.connection_status = status;
+        }
+
+        fn set_registration(&mut self, status: RegistrationStatus) {
+            self.registration_status = status;
+        }
+    }
+
+    impl Behaviour {
+        pub fn new(identity: identity::Keypair, rendezvous_nodes: Vec<RendezvousNode>) -> Self {
+            Self {
+                inner: libp2p::rendezvous::client::Behaviour::new(identity),
+                rendezvous_nodes,
+                to_dial: VecDeque::new(),
+            }
+        }
+
+        /// Calls the rendezvous register method of the node at node_index in the Vec of rendezvous nodes
+        fn register(&mut self, node_index: usize) {
+            let node = &self.rendezvous_nodes[node_index];
+            self.inner
+                .register(node.namespace.into(), node.peer_id, node.registration_ttl);
         }
     }
 
@@ -255,31 +275,37 @@ pub mod rendezous {
         }
 
         fn addresses_of_peer(&mut self, peer_id: &PeerId) -> Vec<Multiaddr> {
-            if peer_id == &self.rendezvous_peer_id {
-                return vec![self.rendezvous_point.clone()];
+            for node in self.rendezvous_nodes.iter() {
+                if peer_id == &node.peer_id {
+                    return vec![node.address.clone()];
+                }
             }
 
             vec![]
         }
 
         fn inject_connected(&mut self, peer_id: &PeerId) {
-            if peer_id == &self.rendezvous_peer_id {
-                self.connection_status = ConnectionStatus::Connected;
-
-                match &self.registration_status {
-                    RegistrationStatus::RegisterOnNextConnection => {
-                        self.register();
-                        self.registration_status = RegistrationStatus::Pending;
+            for i in 0..self.rendezvous_nodes.len() {
+                if peer_id == &self.rendezvous_nodes[i].peer_id {
+                    self.rendezvous_nodes[i].set_connection(ConnectionStatus::Connected);
+                    match &self.rendezvous_nodes[i].registration_status {
+                        RegistrationStatus::RegisterOnNextConnection => {
+                            self.register(i);
+                            self.rendezvous_nodes[i].set_registration(RegistrationStatus::Pending);
+                        }
+                        RegistrationStatus::Registered { .. } => {}
+                        RegistrationStatus::Pending => {}
                     }
-                    RegistrationStatus::Registered { .. } => {}
-                    RegistrationStatus::Pending => {}
                 }
             }
         }
 
         fn inject_disconnected(&mut self, peer_id: &PeerId) {
-            if peer_id == &self.rendezvous_peer_id {
-                self.connection_status = ConnectionStatus::Disconnected;
+            for i in 0..self.rendezvous_nodes.len() {
+                let mut node = &mut self.rendezvous_nodes[i];
+                if peer_id == &node.peer_id {
+                    node.connection_status = ConnectionStatus::Disconnected;
+                }
             }
         }
 
@@ -298,9 +324,12 @@ pub mod rendezous {
             _handler: Self::ProtocolsHandler,
             _error: &DialError,
         ) {
-            if let Some(id) = peer_id {
-                if id == self.rendezvous_peer_id {
-                    self.connection_status = ConnectionStatus::Disconnected;
+            for i in 0..self.rendezvous_nodes.len() {
+                let mut node = &mut self.rendezvous_nodes[i];
+                if let Some(id) = peer_id {
+                    if id == node.peer_id {
+                        node.connection_status = ConnectionStatus::Disconnected;
+                    }
                 }
             }
         }
@@ -311,62 +340,73 @@ pub mod rendezous {
             cx: &mut std::task::Context<'_>,
             params: &mut impl PollParameters,
         ) -> Poll<NetworkBehaviourAction<Self::OutEvent, Self::ProtocolsHandler>> {
-            match &mut self.registration_status {
-                RegistrationStatus::RegisterOnNextConnection => match self.connection_status {
-                    ConnectionStatus::Disconnected => {
-                        self.connection_status = ConnectionStatus::Dialling;
-
-                        return Poll::Ready(NetworkBehaviourAction::Dial {
-                            opts: DialOpts::peer_id(self.rendezvous_peer_id)
-                                .condition(PeerCondition::Disconnected)
-                                .build(),
-
-                            handler: Self::ProtocolsHandler::new(Duration::from_secs(30)),
-                        });
-                    }
-                    ConnectionStatus::Dialling => {}
-                    ConnectionStatus::Connected => {
-                        self.registration_status = RegistrationStatus::Pending;
-                        self.register();
-                    }
-                },
-                RegistrationStatus::Registered { re_register_in } => {
-                    if let Poll::Ready(()) = re_register_in.poll_unpin(cx) {
-                        match self.connection_status {
-                            ConnectionStatus::Connected => {
-                                self.registration_status = RegistrationStatus::Pending;
-                                self.register();
-                            }
-                            ConnectionStatus::Disconnected => {
-                                self.registration_status =
-                                    RegistrationStatus::RegisterOnNextConnection;
-
-                                return Poll::Ready(NetworkBehaviourAction::Dial {
-                                    opts: DialOpts::peer_id(self.rendezvous_peer_id)
-                                        .condition(PeerCondition::Disconnected)
-                                        .build(),
-                                    handler: Self::ProtocolsHandler::new(Duration::from_secs(30)),
-                                });
+            if let Some(peer_id) = self.to_dial.pop_front() {
+                return Poll::Ready(NetworkBehaviourAction::Dial {
+                    opts: DialOpts::peer_id(peer_id)
+                        .condition(PeerCondition::Disconnected)
+                        .build(),
+
+                    handler: Self::ProtocolsHandler::new(Duration::from_secs(30)),
+                });
+            }
+            // check the status of each rendezvous node
+            for i in 0..self.rendezvous_nodes.len() {
+                let connection_status = self.rendezvous_nodes[i].connection_status.clone();
+                match &mut self.rendezvous_nodes[i].registration_status {
+                    RegistrationStatus::RegisterOnNextConnection => match connection_status {
+                        ConnectionStatus::Disconnected => {
+                            self.rendezvous_nodes[i].set_connection(ConnectionStatus::Dialling);
+                            self.to_dial.push_back(self.rendezvous_nodes[i].peer_id);
+                        }
+                        ConnectionStatus::Dialling => {}
+                        ConnectionStatus::Connected => {
+                            self.rendezvous_nodes[i].set_registration(RegistrationStatus::Pending);
+                            self.register(i);
+                        }
+                    },
+                    RegistrationStatus::Registered { re_register_in } => {
+                        if let Poll::Ready(()) = re_register_in.poll_unpin(cx) {
+                            match connection_status {
+                                ConnectionStatus::Connected => {
+                                    self.rendezvous_nodes[i]
+                                        .set_registration(RegistrationStatus::Pending);
+                                    self.register(i);
+                                }
+                                ConnectionStatus::Disconnected => {
+                                    self.rendezvous_nodes[i].set_registration(
+                                        RegistrationStatus::RegisterOnNextConnection,
+                                    );
+                                    self.to_dial.push_back(self.rendezvous_nodes[i].peer_id);
+                                }
+                                ConnectionStatus::Dialling => {}
                             }
-                            ConnectionStatus::Dialling => {}
                         }
                     }
+                    RegistrationStatus::Pending => {}
                 }
-                RegistrationStatus::Pending => {}
             }
 
             let inner_poll = self.inner.poll(cx, params);
 
-            // reset the timer if we successfully registered
+            // reset the timer for the specific rendezvous node if we successfully registered
             if let Poll::Ready(NetworkBehaviourAction::GenerateEvent(
-                libp2p::rendezvous::client::Event::Registered { ttl, .. },
+                libp2p::rendezvous::client::Event::Registered {
+                    ttl,
+                    rendezvous_node,
+                    ..
+                },
             )) = &inner_poll
             {
-                let half_of_ttl = Duration::from_secs(*ttl) / 2;
-
-                self.registration_status = RegistrationStatus::Registered {
-                    re_register_in: Box::pin(tokio::time::sleep(half_of_ttl)),
-                };
+                if let Some(i) = self
+                    .rendezvous_nodes
+                    .iter()
+                    .position(|n| &n.peer_id == rendezvous_node)
+                {
+                    let half_of_ttl = Duration::from_secs(*ttl) / 2;
+                    let re_register_in = Box::pin(tokio::time::sleep(half_of_ttl));
+                    let status = RegistrationStatus::Registered { re_register_in };
+                    self.rendezvous_nodes[i].set_registration(status);
+                }
             }
 
             inner_poll
@@ -380,6 +420,7 @@ pub mod rendezous {
         use futures::StreamExt;
         use libp2p::rendezvous;
         use libp2p::swarm::SwarmEvent;
+        use std::collections::HashMap;
 
         #[tokio::test]
         async fn given_no_initial_connection_when_constructed_asb_connects_and_registers_with_rendezvous_node(
@@ -387,16 +428,16 @@ pub mod rendezous {
             let mut rendezvous_node = new_swarm(|_, _| {
                 rendezvous::server::Behaviour::new(rendezvous::server::Config::default())
             });
-            let rendezvous_address = rendezvous_node.listen_on_random_memory_address().await;
+            let address = rendezvous_node.listen_on_random_memory_address().await;
+            let rendezvous_point = RendezvousNode::new(
+                &address,
+                rendezvous_node.local_peer_id().to_owned(),
+                XmrBtcNamespace::Testnet,
+                None,
+            );
 
             let mut asb = new_swarm(|_, identity| {
-                rendezous::Behaviour::new(
-                    identity,
-                    *rendezvous_node.local_peer_id(),
-                    rendezvous_address,
-                    XmrBtcNamespace::Testnet,
-                    None,
-                )
+                super::rendezvous::Behaviour::new(identity, vec![rendezvous_point])
             });
             asb.listen_on_random_memory_address().await; // this adds an external address
 
@@ -428,16 +469,16 @@ pub mod rendezous {
                     rendezvous::server::Config::default().with_min_ttl(2),
                 )
             });
-            let rendezvous_address = rendezvous_node.listen_on_random_memory_address().await;
+            let address = rendezvous_node.listen_on_random_memory_address().await;
+            let rendezvous_point = RendezvousNode::new(
+                &address,
+                rendezvous_node.local_peer_id().to_owned(),
+                XmrBtcNamespace::Testnet,
+                Some(5),
+            );
 
             let mut asb = new_swarm(|_, identity| {
-                rendezous::Behaviour::new(
-                    identity,
-                    *rendezvous_node.local_peer_id(),
-                    rendezvous_address,
-                    XmrBtcNamespace::Testnet,
-                    Some(5),
-                )
+                super::rendezvous::Behaviour::new(identity, vec![rendezvous_point])
             });
             asb.listen_on_random_memory_address().await; // this adds an external address
 
@@ -467,5 +508,62 @@ pub mod rendezous {
                 .unwrap()
                 .unwrap();
         }
+
+        #[tokio::test]
+        async fn asb_registers_multiple() {
+            let registration_ttl = Some(10);
+            let mut rendezvous_nodes = Vec::new();
+            let mut registrations = HashMap::new();
+            // register with 5 rendezvous nodes
+            for _ in 0..5 {
+                let mut rendezvous = new_swarm(|_, _| {
+                    rendezvous::server::Behaviour::new(
+                        rendezvous::server::Config::default().with_min_ttl(2),
+                    )
+                });
+                let address = rendezvous.listen_on_random_memory_address().await;
+                let id = *rendezvous.local_peer_id();
+                registrations.insert(id, 0);
+                rendezvous_nodes.push(RendezvousNode::new(
+                    &address,
+                    *rendezvous.local_peer_id(),
+                    XmrBtcNamespace::Testnet,
+                    registration_ttl,
+                ));
+                tokio::spawn(async move {
+                    loop {
+                        rendezvous.next().await;
+                    }
+                });
+            }
+
+            let mut asb = new_swarm(|_, identity| {
+                super::rendezvous::Behaviour::new(identity, rendezvous_nodes)
+            });
+            asb.listen_on_random_memory_address().await; // this adds an external address
+
+            let handle = tokio::spawn(async move {
+                loop {
+                    if let SwarmEvent::Behaviour(rendezvous::client::Event::Registered {
+                        rendezvous_node,
+                        ..
+                    }) = asb.select_next_some().await
+                    {
+                        registrations
+                            .entry(rendezvous_node)
+                            .and_modify(|counter| *counter += 1);
+                    }
+
+                    if registrations.iter().all(|(_, &count)| count >= 4) {
+                        break;
+                    }
+                }
+            });
+
+            tokio::time::timeout(Duration::from_secs(30), handle)
+                .await
+                .unwrap()
+                .unwrap();
+        }
     }
 }

swap/src/bin/asb.rs

@@ -102,6 +102,19 @@ async fn main() -> Result<()> {
 
     match cmd {
         Command::Start { resume_only } => {
+            // check and warn for duplicate rendezvous points
+            let mut rendezvous_addrs = config.network.rendezvous_point.clone();
+            let prev_len = rendezvous_addrs.len();
+            rendezvous_addrs.sort();
+            rendezvous_addrs.dedup();
+            let new_len = rendezvous_addrs.len();
+            if new_len < prev_len {
+                tracing::warn!(
+                    "`rendezvous_point` config has {} duplicate entries, they are being ignored.",
+                    prev_len - new_len
+                );
+            }
+
             let monero_wallet = init_monero_wallet(&config, env_config).await?;
             let monero_address = monero_wallet.get_main_address();
             tracing::info!(%monero_address, "Monero wallet address");
@@ -161,7 +174,7 @@ async fn main() -> Result<()> {
                 resume_only,
                 env_config,
                 namespace,
-                config.network.rendezvous_point,
+                &rendezvous_addrs,
             )?;
 
             for listen in config.network.listen.clone() {

swap/src/cli.rs

@@ -15,6 +15,7 @@ pub use list_sellers::{list_sellers, Seller, Status as SellerStatus};
 mod tests {
     use super::*;
     use crate::asb;
+    use crate::asb::rendezvous::RendezvousNode;
     use crate::cli::list_sellers::{Seller, Status};
     use crate::network::quote;
     use crate::network::quote::BidQuote;
@@ -33,10 +34,8 @@ mod tests {
     async fn list_sellers_should_report_all_registered_asbs_with_a_quote() {
         let namespace = XmrBtcNamespace::Mainnet;
         let (rendezvous_address, rendezvous_peer_id) = setup_rendezvous_point().await;
-        let expected_seller_1 =
-            setup_asb(rendezvous_peer_id, rendezvous_address.clone(), namespace).await;
-        let expected_seller_2 =
-            setup_asb(rendezvous_peer_id, rendezvous_address.clone(), namespace).await;
+        let expected_seller_1 = setup_asb(rendezvous_peer_id, &rendezvous_address, namespace).await;
+        let expected_seller_2 = setup_asb(rendezvous_peer_id, &rendezvous_address, namespace).await;
 
         let list_sellers = list_sellers(
             rendezvous_peer_id,
@@ -72,7 +71,7 @@ mod tests {
 
     async fn setup_asb(
         rendezvous_peer_id: PeerId,
-        rendezvous_address: Multiaddr,
+        rendezvous_address: &Multiaddr,
         namespace: XmrBtcNamespace,
     ) -> Seller {
         let static_quote = BidQuote {
@@ -81,18 +80,18 @@ mod tests {
             max_quantity: bitcoin::Amount::from_sat(9001),
         };
 
-        let mut asb = new_swarm(|_, identity| StaticQuoteAsbBehaviour {
-            rendezvous: asb::rendezous::Behaviour::new(
-                identity,
-                rendezvous_peer_id,
-                rendezvous_address,
-                namespace,
-                None,
-            ),
-            ping: Default::default(),
-            quote: quote::asb(),
-            static_quote,
-            registered: false,
+        let mut asb = new_swarm(|_, identity| {
+            let rendezvous_node =
+                RendezvousNode::new(rendezvous_address, rendezvous_peer_id, namespace, None);
+            let rendezvous = asb::rendezvous::Behaviour::new(identity, vec![rendezvous_node]);
+
+            StaticQuoteAsbBehaviour {
+                rendezvous,
+                ping: Default::default(),
+                quote: quote::asb(),
+                static_quote,
+                registered: false,
+            }
         });
 
         let asb_address = asb.listen_on_tcp_localhost().await;
@@ -121,7 +120,7 @@ mod tests {
     #[derive(libp2p::NetworkBehaviour)]
     #[behaviour(event_process = true)]
     struct StaticQuoteAsbBehaviour {
-        rendezvous: asb::rendezous::Behaviour,
+        rendezvous: asb::rendezvous::Behaviour,
         // Support `Ping` as a workaround until https://github.com/libp2p/rust-libp2p/issues/2109 is fixed.
         ping: libp2p::ping::Ping,
         quote: quote::Behaviour,

swap/src/network/swarm.rs

@@ -1,9 +1,9 @@
-use crate::asb::LatestRate;
+use crate::asb::{LatestRate, RendezvousNode};
 use crate::libp2p_ext::MultiAddrExt;
 use crate::network::rendezvous::XmrBtcNamespace;
 use crate::seed::Seed;
 use crate::{asb, bitcoin, cli, env, tor};
-use anyhow::{Context, Result};
+use anyhow::Result;
 use libp2p::swarm::{NetworkBehaviour, SwarmBuilder};
 use libp2p::{identity, Multiaddr, Swarm};
 use std::fmt::Debug;
@@ -17,22 +17,23 @@ pub fn asb<LR>(
     resume_only: bool,
     env_config: env::Config,
     namespace: XmrBtcNamespace,
-    rendezvous_point: Option<Multiaddr>,
+    rendezvous_addrs: &[Multiaddr],
 ) -> Result<Swarm<asb::Behaviour<LR>>>
 where
     LR: LatestRate + Send + 'static + Debug + Clone,
 {
     let identity = seed.derive_libp2p_identity();
 
-    let rendezvous_params = if let Some(address) = rendezvous_point {
-        let peer_id = address
-            .extract_peer_id()
-            .context("Rendezvous node address must contain peer ID")?;
+    let rendezvous_nodes = rendezvous_addrs
+        .iter()
+        .map(|addr| {
+            let peer_id = addr
+                .extract_peer_id()
+                .expect("Rendezvous node address must contain peer ID");
 
-        Some((identity.clone(), peer_id, address, namespace))
-    } else {
-        None
-    };
+            RendezvousNode::new(addr, peer_id, namespace, None)
+        })
+        .collect();
 
     let behaviour = asb::Behaviour::new(
         min_buy,
@@ -41,7 +42,7 @@ where
         resume_only,
         env_config,
         (identity.clone(), namespace),
-        rendezvous_params,
+        rendezvous_nodes,
     );
 
     let transport = asb::transport::new(&identity)?;

swap/tests/harness/mod.rs

@@ -248,7 +248,7 @@ async fn start_alice(
         resume_only,
         env_config,
         XmrBtcNamespace::Testnet,
-        None,
+        &[],
     )
     .unwrap();
     swarm.listen_on(listen_address).unwrap();