Merge #265

265: Replace quote with spot-price protocol r=thomaseizinger a=thomaseizinger

This is essentially functionally equivalent but includes some
cleanups by removing a layer of abstraction: `spot_price::Behaviour`
is now just a type-alias for a request-response behaviour.

Co-authored-by: Thomas Eizinger <thomas@eizinger.io>

swap/src/network.rs

@@ -1,5 +1,6 @@
 pub mod peer_tracker;
 pub mod request_response;
+pub mod spot_price;
 pub mod transport;
 
 use futures::prelude::*;

swap/src/network/request_response.rs

@@ -13,21 +13,12 @@ pub const TIMEOUT: u64 = 3600; // One hour.
 /// Message receive buffer.
 pub const BUF_SIZE: usize = 1024 * 1024;
 
-#[derive(Debug, Clone, Copy, Default)]
-pub struct Swap;
-
 #[derive(Debug, Clone, Copy, Default)]
 pub struct TransferProofProtocol;
 
 #[derive(Debug, Clone, Copy, Default)]
 pub struct EncryptedSignatureProtocol;
 
-impl ProtocolName for Swap {
-    fn protocol_name(&self) -> &[u8] {
-        b"/comit/xmr/btc/swap/1.0.0"
-    }
-}
-
 impl ProtocolName for TransferProofProtocol {
     fn protocol_name(&self) -> &[u8] {
         b"/comit/xmr/btc/transfer_proof/1.0.0"

swap/src/network/spot_price.rs

@@ -0,0 +1,66 @@
+use crate::{bitcoin, monero, network::request_response::CborCodec};
+use libp2p::{
+    core::ProtocolName,
+    request_response::{
+        ProtocolSupport, RequestResponse, RequestResponseConfig, RequestResponseEvent,
+    },
+};
+use serde::{Deserialize, Serialize};
+
+pub type OutEvent = RequestResponseEvent<SpotPriceRequest, SpotPriceResponse>;
+
+/// The spot price protocol allows parties to **initiate** a trade by requesting
+/// a spot price.
+///
+/// A spot price is binding for both parties, i.e. after the spot-price protocol
+/// completes, both parties are expected to follow up with the `execution-setup`
+/// protocol.
+///
+/// If a party wishes to only inquire about the current price, they should use
+/// the `quote` protocol instead.
+#[derive(Debug, Clone, Copy, Default)]
+pub struct SpotPriceProtocol;
+
+impl ProtocolName for SpotPriceProtocol {
+    fn protocol_name(&self) -> &[u8] {
+        b"/comit/xmr/btc/spot-price/1.0.0"
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct SpotPriceRequest {
+    #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
+    pub btc: bitcoin::Amount,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct SpotPriceResponse {
+    pub xmr: monero::Amount,
+}
+
+pub type Behaviour =
+    RequestResponse<CborCodec<SpotPriceProtocol, SpotPriceRequest, SpotPriceResponse>>;
+
+/// Constructs a new instance of the `spot-price` behaviour to be used by Alice.
+///
+/// Alice only supports inbound connections, i.e. providing spot prices for BTC
+/// in XMR.
+pub fn alice() -> Behaviour {
+    Behaviour::new(
+        CborCodec::default(),
+        vec![(SpotPriceProtocol, ProtocolSupport::Inbound)],
+        RequestResponseConfig::default(),
+    )
+}
+
+/// Constructs a new instance of the `spot-price` behaviour to be used by Bob.
+///
+/// Bob only supports outbound connections, i.e. requesting a spot price for a
+/// given amount of BTC in XMR.
+pub fn bob() -> Behaviour {
+    Behaviour::new(
+        CborCodec::default(),
+        vec![(SpotPriceProtocol, ProtocolSupport::Outbound)],
+        RequestResponseConfig::default(),
+    )
+}

swap/src/protocol/alice.rs

@@ -8,7 +8,6 @@ pub use self::{
     behaviour::{Behaviour, OutEvent},
     event_loop::{EventLoop, EventLoopHandle},
     execution_setup::Message1,
-    quote_response::*,
     state::*,
     swap::{run, run_until},
     transfer_proof::TransferProof,
@@ -19,7 +18,6 @@ mod behaviour;
 mod encrypted_signature;
 pub mod event_loop;
 mod execution_setup;
-mod quote_response;
 pub mod state;
 mod steps;
 pub mod swap;

swap/src/protocol/alice/behaviour.rs

@@ -1,24 +1,35 @@
 use crate::{
-    network::{peer_tracker, peer_tracker::PeerTracker},
+    bitcoin,
+    execution_params::ExecutionParams,
+    monero,
+    network::{
+        peer_tracker,
+        peer_tracker::PeerTracker,
+        spot_price,
+        spot_price::{SpotPriceRequest, SpotPriceResponse},
+    },
     protocol::{
         alice::{
-            encrypted_signature, execution_setup, quote_response, transfer_proof, QuoteResponse,
-            State0, State3, TransferProof,
+            encrypted_signature, execution_setup, transfer_proof, State0, State3, TransferProof,
         },
-        bob::{EncryptedSignature, QuoteRequest},
+        bob::EncryptedSignature,
     },
 };
-use anyhow::{Error, Result};
-use libp2p::{request_response::ResponseChannel, NetworkBehaviour, PeerId};
+use anyhow::{anyhow, Error, Result};
+use libp2p::{
+    request_response::{RequestResponseMessage, ResponseChannel},
+    NetworkBehaviour, PeerId,
+};
+use rand::{CryptoRng, RngCore};
 use tracing::debug;
 
 #[derive(Debug)]
 pub enum OutEvent {
     ConnectionEstablished(PeerId),
-    QuoteRequest {
-        msg: QuoteRequest,
-        channel: ResponseChannel<QuoteResponse>,
-        bob_peer_id: PeerId,
+    SpotPriceRequested {
+        msg: SpotPriceRequest,
+        channel: ResponseChannel<SpotPriceResponse>,
+        peer: PeerId,
     },
     ExecutionSetupDone {
         bob_peer_id: PeerId,
@@ -43,21 +54,37 @@ impl From<peer_tracker::OutEvent> for OutEvent {
     }
 }
 
-impl From<quote_response::OutEvent> for OutEvent {
-    fn from(event: quote_response::OutEvent) -> Self {
-        use crate::protocol::alice::quote_response::OutEvent::*;
+impl From<spot_price::OutEvent> for OutEvent {
+    fn from(event: spot_price::OutEvent) -> Self {
         match event {
-            MsgReceived {
-                msg,
-                channel,
-                bob_peer_id,
-            } => OutEvent::QuoteRequest {
-                msg,
-                channel,
-                bob_peer_id,
-            },
-            ResponseSent => OutEvent::ResponseSent,
-            Failure(err) => OutEvent::Failure(err.context("Quote Request/Response failure")),
+            spot_price::OutEvent::Message {
+                peer,
+                message:
+                    RequestResponseMessage::Request {
+                        channel,
+                        request: msg,
+                        ..
+                    },
+            } => OutEvent::SpotPriceRequested { msg, channel, peer },
+            spot_price::OutEvent::Message {
+                message: RequestResponseMessage::Response { .. },
+                ..
+            } => OutEvent::Failure(anyhow!(
+                "Alice is only meant to hand out spot prices, not receive them"
+            )),
+            spot_price::OutEvent::ResponseSent { .. } => OutEvent::ResponseSent,
+            spot_price::OutEvent::InboundFailure { peer, error, .. } => OutEvent::Failure(anyhow!(
+                "spot_price protocol with peer {} failed due to {:?}",
+                peer,
+                error
+            )),
+            spot_price::OutEvent::OutboundFailure { peer, error, .. } => {
+                OutEvent::Failure(anyhow!(
+                    "spot_price protocol with peer {} failed due to {:?}",
+                    peer,
+                    error
+                ))
+            }
         }
     }
 }
@@ -103,29 +130,62 @@ impl From<encrypted_signature::OutEvent> for OutEvent {
 }
 
 /// A `NetworkBehaviour` that represents an XMR/BTC swap node as Alice.
-#[derive(NetworkBehaviour, Default)]
+#[derive(NetworkBehaviour)]
 #[behaviour(out_event = "OutEvent", event_process = false)]
 #[allow(missing_debug_implementations)]
 pub struct Behaviour {
     pt: PeerTracker,
-    quote_response: quote_response::Behaviour,
+    spot_price: spot_price::Behaviour,
     execution_setup: execution_setup::Behaviour,
     transfer_proof: transfer_proof::Behaviour,
     encrypted_signature: encrypted_signature::Behaviour,
 }
 
+impl Default for Behaviour {
+    fn default() -> Self {
+        Self {
+            pt: Default::default(),
+            spot_price: spot_price::alice(),
+            execution_setup: Default::default(),
+            transfer_proof: Default::default(),
+            encrypted_signature: Default::default(),
+        }
+    }
+}
+
 impl Behaviour {
-    pub fn send_quote_response(
+    pub fn send_spot_price(
         &mut self,
-        channel: ResponseChannel<QuoteResponse>,
-        quote_response: QuoteResponse,
+        channel: ResponseChannel<SpotPriceResponse>,
+        response: SpotPriceResponse,
     ) -> Result<()> {
-        self.quote_response.send(channel, quote_response)?;
+        self.spot_price
+            .send_response(channel, response)
+            .map_err(|_| anyhow!("failed to respond with spot price"))?;
+
         Ok(())
     }
 
-    pub fn start_execution_setup(&mut self, bob_peer_id: PeerId, state0: State0) {
-        self.execution_setup.run(bob_peer_id, state0);
+    pub async fn start_execution_setup(
+        &mut self,
+        peer: PeerId,
+        btc: bitcoin::Amount,
+        xmr: monero::Amount,
+        execution_params: ExecutionParams,
+        bitcoin_wallet: &bitcoin::Wallet,
+        rng: &mut (impl RngCore + CryptoRng),
+    ) -> Result<()> {
+        let state0 = State0::new(btc, xmr, execution_params, bitcoin_wallet, rng).await?;
+
+        tracing::info!(
+            %peer,
+            "Starting execution setup to sell {} for {}",
+            xmr, btc,
+        );
+
+        self.execution_setup.run(peer, state0);
+
+        Ok(())
     }
 
     /// Send Transfer Proof to Bob.

swap/src/protocol/alice/event_loop.rs

@@ -5,25 +5,21 @@ use crate::{
     execution_params::ExecutionParams,
     monero,
     monero::BalanceTooLow,
-    network::{transport, TokioExecutor},
+    network::{spot_price::SpotPriceResponse, transport, TokioExecutor},
     protocol::{
         alice,
-        alice::{
-            AliceState, Behaviour, OutEvent, QuoteResponse, State0, State3, Swap, TransferProof,
-        },
-        bob::{EncryptedSignature, QuoteRequest},
+        alice::{AliceState, Behaviour, OutEvent, State3, Swap, TransferProof},
+        bob::EncryptedSignature,
     },
     seed::Seed,
 };
 use anyhow::{bail, Context, Result};
 use futures::future::RemoteHandle;
-use libp2p::{
-    core::Multiaddr, futures::FutureExt, request_response::ResponseChannel, PeerId, Swarm,
-};
+use libp2p::{core::Multiaddr, futures::FutureExt, PeerId, Swarm};
 use rand::rngs::OsRng;
 use std::sync::Arc;
 use tokio::sync::{broadcast, mpsc, mpsc::error::SendError};
-use tracing::{debug, error, info, trace};
+use tracing::{debug, error, trace};
 use uuid::Uuid;
 
 #[allow(missing_debug_implementations)]
@@ -166,9 +162,30 @@ where
                         OutEvent::ConnectionEstablished(alice) => {
                             debug!("Connection Established with {}", alice);
                         }
-                        OutEvent::QuoteRequest { msg, channel, bob_peer_id } => {
-                            if let Err(error) = self.handle_quote_request(msg, channel, bob_peer_id, self.monero_wallet.clone()).await {
-                                error!("Failed to handle quote request: {:#}", error);
+                        OutEvent::SpotPriceRequested { msg, channel, peer } => {
+                            let btc = msg.btc;
+                            let xmr = match self.handle_spot_price_request(btc, self.monero_wallet.clone()).await {
+                                Ok(xmr) => xmr,
+                                Err(e) => {
+                                    tracing::warn!(%peer, "failed to produce spot price for {}: {:#}", btc, e);
+                                    continue;
+                                }
+                            };
+
+                            match self.swarm.send_spot_price(channel, SpotPriceResponse { xmr }) {
+                                Ok(_) => {},
+                                Err(e) => {
+                                    // if we can't respond, the peer probably just disconnected so it is not a huge deal, only log this on debug
+                                    debug!(%peer, "failed to respond with spot price: {:#}", e);
+                                    continue;
+                                }
+                            }
+
+                            match self.swarm.start_execution_setup(peer, btc, xmr, self.execution_params, self.bitcoin_wallet.as_ref(), &mut OsRng).await {
+                                Ok(_) => {},
+                                Err(e) => {
+                                    tracing::warn!(%peer, "failed to start execution setup: {:#}", e);
+                                }
                             }
                         }
                         OutEvent::ExecutionSetupDone{bob_peer_id, state3} => {
@@ -199,65 +216,34 @@ where
         }
     }
 
-    async fn handle_quote_request(
+    async fn handle_spot_price_request(
         &mut self,
-        quote_request: QuoteRequest,
-        channel: ResponseChannel<QuoteResponse>,
-        bob_peer_id: PeerId,
+        btc: bitcoin::Amount,
         monero_wallet: Arc<monero::Wallet>,
-    ) -> Result<()> {
-        // 1. Check if acceptable request
-        // 2. Send response
-
+    ) -> Result<monero::Amount> {
         let rate = self
             .rate_service
             .latest_rate()
             .context("Failed to get latest rate")?;
 
-        let btc_amount = quote_request.btc_amount;
-
-        if btc_amount > self.max_buy {
+        if btc > self.max_buy {
             bail!(MaximumBuyAmountExceeded {
-                actual: btc_amount,
+                actual: btc,
                 max: self.max_buy
             })
         }
 
         let xmr_balance = monero_wallet.get_balance().await?;
         let xmr_lock_fees = monero_wallet.static_tx_fee_estimate();
-        let xmr_amount = rate.sell_quote(btc_amount)?;
+        let xmr = rate.sell_quote(btc)?;
 
-        if xmr_balance < xmr_amount + xmr_lock_fees {
+        if xmr_balance < xmr + xmr_lock_fees {
             bail!(BalanceTooLow {
                 balance: xmr_balance
             })
         }
 
-        let quote_response = QuoteResponse { xmr_amount };
-
-        self.swarm
-            .send_quote_response(channel, quote_response)
-            .context("Failed to send quote response")?;
-
-        // 3. Start setup execution
-
-        let state0 = State0::new(
-            btc_amount,
-            xmr_amount,
-            self.execution_params,
-            self.bitcoin_wallet.as_ref(),
-            &mut OsRng,
-        )
-        .await?;
-
-        info!(
-            "Starting execution setup to sell {} for {} (rate of {}) with {}",
-            xmr_amount, btc_amount, rate, bob_peer_id
-        );
-
-        self.swarm.start_execution_setup(bob_peer_id, state0);
-        // Continues once the execution setup protocol is done
-        Ok(())
+        Ok(xmr)
     }
 
     async fn handle_execution_setup_done(

swap/src/protocol/alice/quote_response.rs

@@ -1,109 +0,0 @@
-use crate::{
-    monero,
-    network::request_response::{CborCodec, Swap, TIMEOUT},
-    protocol::bob::QuoteRequest,
-};
-use anyhow::{anyhow, Error, Result};
-use libp2p::{
-    request_response::{
-        ProtocolSupport, RequestResponse, RequestResponseConfig, RequestResponseEvent,
-        RequestResponseMessage, ResponseChannel,
-    },
-    NetworkBehaviour, PeerId,
-};
-use serde::{Deserialize, Serialize};
-use std::time::Duration;
-use tracing::debug;
-
-#[derive(Debug)]
-pub enum OutEvent {
-    MsgReceived {
-        msg: QuoteRequest,
-        channel: ResponseChannel<QuoteResponse>,
-        bob_peer_id: PeerId,
-    },
-    ResponseSent,
-    Failure(Error),
-}
-
-#[derive(Copy, Clone, Debug, Serialize, Deserialize)]
-pub struct QuoteResponse {
-    pub xmr_amount: monero::Amount,
-}
-
-impl From<RequestResponseEvent<QuoteRequest, QuoteResponse>> for OutEvent {
-    fn from(event: RequestResponseEvent<QuoteRequest, QuoteResponse>) -> Self {
-        match event {
-            RequestResponseEvent::Message {
-                peer,
-                message:
-                    RequestResponseMessage::Request {
-                        request, channel, ..
-                    },
-                ..
-            } => {
-                debug!("Received quote request from {}", peer);
-                OutEvent::MsgReceived {
-                    msg: request,
-                    channel,
-                    bob_peer_id: peer,
-                }
-            }
-            RequestResponseEvent::Message {
-                message: RequestResponseMessage::Response { .. },
-                ..
-            } => OutEvent::Failure(anyhow!("Alice should not get a Response")),
-            RequestResponseEvent::InboundFailure { error, .. } => {
-                OutEvent::Failure(anyhow!("Inbound failure: {:?}", error))
-            }
-            RequestResponseEvent::OutboundFailure { error, .. } => {
-                OutEvent::Failure(anyhow!("Outbound failure: {:?}", error))
-            }
-            RequestResponseEvent::ResponseSent { peer, .. } => {
-                tracing::debug!("successfully sent quote response to {}", peer);
-                OutEvent::ResponseSent
-            }
-        }
-    }
-}
-
-/// A `NetworkBehaviour` that represents negotiate a swap using Swap
-/// request/response.
-#[derive(NetworkBehaviour)]
-#[behaviour(out_event = "OutEvent", event_process = false)]
-#[allow(missing_debug_implementations)]
-pub struct Behaviour {
-    rr: RequestResponse<CborCodec<Swap, QuoteRequest, QuoteResponse>>,
-}
-
-impl Behaviour {
-    /// Alice always sends her messages as a response to a request from Bob.
-    pub fn send(
-        &mut self,
-        channel: ResponseChannel<QuoteResponse>,
-        msg: QuoteResponse,
-    ) -> Result<()> {
-        self.rr
-            .send_response(channel, msg)
-            .map_err(|_| anyhow!("failed to send quote response"))?;
-
-        Ok(())
-    }
-}
-
-impl Default for Behaviour {
-    fn default() -> Self {
-        let timeout = Duration::from_secs(TIMEOUT);
-
-        let mut config = RequestResponseConfig::default();
-        config.set_request_timeout(timeout);
-
-        Self {
-            rr: RequestResponse::new(
-                CborCodec::default(),
-                vec![(Swap, ProtocolSupport::Inbound)],
-                config,
-            ),
-        }
-    }
-}

swap/src/protocol/bob.rs

@@ -1,15 +1,22 @@
-//! Run an XMR/BTC swap in the role of Bob.
-//! Bob holds BTC and wishes receive XMR.
 use crate::{
     bitcoin,
     database::Database,
     execution_params::ExecutionParams,
     monero,
-    network::peer_tracker::{self, PeerTracker},
-    protocol::{alice, alice::TransferProof, bob},
+    network::{
+        peer_tracker::{self, PeerTracker},
+        spot_price,
+        spot_price::{SpotPriceRequest, SpotPriceResponse},
+    },
+    protocol::{alice::TransferProof, bob},
+};
+use anyhow::{anyhow, Error, Result};
+pub use execution_setup::{Message0, Message2, Message4};
+use libp2p::{
+    core::Multiaddr,
+    request_response::{RequestResponseMessage, ResponseChannel},
+    NetworkBehaviour, PeerId,
 };
-use anyhow::{Error, Result};
-use libp2p::{core::Multiaddr, NetworkBehaviour, PeerId};
 use std::sync::Arc;
 use tracing::debug;
 use uuid::Uuid;
@@ -18,19 +25,15 @@ pub use self::{
     cancel::cancel,
     encrypted_signature::EncryptedSignature,
     event_loop::{EventLoop, EventLoopHandle},
-    quote_request::*,
     refund::refund,
     state::*,
     swap::{run, run_until},
 };
-pub use execution_setup::{Message0, Message2, Message4};
-use libp2p::request_response::ResponseChannel;
 
 pub mod cancel;
 mod encrypted_signature;
 pub mod event_loop;
 mod execution_setup;
-mod quote_request;
 pub mod refund;
 pub mod state;
 pub mod swap;
@@ -119,7 +122,7 @@ impl Builder {
 #[derive(Debug)]
 pub enum OutEvent {
     ConnectionEstablished(PeerId),
-    QuoteResponse(alice::QuoteResponse),
+    SpotPriceReceived(SpotPriceResponse),
     ExecutionSetupDone(Result<Box<State2>>),
     TransferProof {
         msg: Box<TransferProof>,
@@ -140,12 +143,34 @@ impl From<peer_tracker::OutEvent> for OutEvent {
     }
 }
 
-impl From<quote_request::OutEvent> for OutEvent {
-    fn from(event: quote_request::OutEvent) -> Self {
-        use quote_request::OutEvent::*;
+impl From<spot_price::OutEvent> for OutEvent {
+    fn from(event: spot_price::OutEvent) -> Self {
         match event {
-            MsgReceived(quote_response) => OutEvent::QuoteResponse(quote_response),
-            Failure(err) => OutEvent::CommunicationError(err.context("Failure with Quote Request")),
+            spot_price::OutEvent::Message {
+                message: RequestResponseMessage::Response { response, .. },
+                ..
+            } => OutEvent::SpotPriceReceived(response),
+            spot_price::OutEvent::Message {
+                message: RequestResponseMessage::Request { .. },
+                ..
+            } => OutEvent::CommunicationError(anyhow!(
+                "Bob is only meant to receive spot prices, not hand them out"
+            )),
+            spot_price::OutEvent::ResponseSent { .. } => OutEvent::ResponseSent,
+            spot_price::OutEvent::InboundFailure { peer, error, .. } => {
+                OutEvent::CommunicationError(anyhow!(
+                    "spot_price protocol with peer {} failed due to {:?}",
+                    peer,
+                    error
+                ))
+            }
+            spot_price::OutEvent::OutboundFailure { peer, error, .. } => {
+                OutEvent::CommunicationError(anyhow!(
+                    "spot_price protocol with peer {} failed due to {:?}",
+                    peer,
+                    error
+                ))
+            }
         }
     }
 }
@@ -187,21 +212,32 @@ impl From<encrypted_signature::OutEvent> for OutEvent {
 }
 
 /// A `NetworkBehaviour` that represents an XMR/BTC swap node as Bob.
-#[derive(NetworkBehaviour, Default)]
+#[derive(NetworkBehaviour)]
 #[behaviour(out_event = "OutEvent", event_process = false)]
 #[allow(missing_debug_implementations)]
 pub struct Behaviour {
     pt: PeerTracker,
-    quote_request: quote_request::Behaviour,
+    spot_price: spot_price::Behaviour,
     execution_setup: execution_setup::Behaviour,
     transfer_proof: transfer_proof::Behaviour,
     encrypted_signature: encrypted_signature::Behaviour,
 }
 
+impl Default for Behaviour {
+    fn default() -> Self {
+        Self {
+            pt: Default::default(),
+            spot_price: spot_price::bob(),
+            execution_setup: Default::default(),
+            transfer_proof: Default::default(),
+            encrypted_signature: Default::default(),
+        }
+    }
+}
+
 impl Behaviour {
-    /// Sends a quote request to Alice to retrieve the rate.
-    pub fn send_quote_request(&mut self, alice: PeerId, quote_request: QuoteRequest) {
-        let _ = self.quote_request.send(alice, quote_request);
+    pub fn request_spot_price(&mut self, alice: PeerId, request: SpotPriceRequest) {
+        let _ = self.spot_price.send_request(&alice, request);
     }
 
     pub fn start_execution_setup(

swap/src/protocol/bob/event_loop.rs

@@ -1,10 +1,14 @@
 use crate::{
     bitcoin,
     bitcoin::EncryptedSignature,
-    network::{transport, TokioExecutor},
+    monero,
+    network::{
+        spot_price::{SpotPriceRequest, SpotPriceResponse},
+        transport, TokioExecutor,
+    },
     protocol::{
-        alice::{QuoteResponse, TransferProof},
-        bob::{Behaviour, OutEvent, QuoteRequest, State0, State2},
+        alice::TransferProof,
+        bob::{Behaviour, OutEvent, State0, State2},
     },
 };
 use anyhow::{anyhow, bail, Context, Result};
@@ -35,24 +39,17 @@ impl<T> Default for Channels<T> {
 
 #[derive(Debug)]
 pub struct EventLoopHandle {
-    recv_quote_response: Receiver<QuoteResponse>,
+    recv_spot_price: Receiver<SpotPriceResponse>,
     start_execution_setup: Sender<State0>,
     done_execution_setup: Receiver<Result<State2>>,
     recv_transfer_proof: Receiver<TransferProof>,
     conn_established: Receiver<PeerId>,
     dial_alice: Sender<()>,
-    send_quote_request: Sender<QuoteRequest>,
+    request_spot_price: Sender<SpotPriceRequest>,
     send_encrypted_signature: Sender<EncryptedSignature>,
 }
 
 impl EventLoopHandle {
-    pub async fn recv_quote_response(&mut self) -> Result<QuoteResponse> {
-        self.recv_quote_response
-            .recv()
-            .await
-            .ok_or_else(|| anyhow!("Failed to receive quote response from Alice"))
-    }
-
     pub async fn execution_setup(&mut self, state0: State0) -> Result<State2> {
         let _ = self.start_execution_setup.send(state0).await?;
 
@@ -82,9 +79,19 @@ impl EventLoopHandle {
         Ok(())
     }
 
-    pub async fn send_quote_request(&mut self, quote_request: QuoteRequest) -> Result<()> {
-        let _ = self.send_quote_request.send(quote_request).await?;
-        Ok(())
+    pub async fn request_spot_price(&mut self, btc: bitcoin::Amount) -> Result<monero::Amount> {
+        let _ = self
+            .request_spot_price
+            .send(SpotPriceRequest { btc })
+            .await?;
+
+        let response = self
+            .recv_spot_price
+            .recv()
+            .await
+            .ok_or_else(|| anyhow!("Failed to receive spot price from Alice"))?;
+
+        Ok(response.xmr)
     }
 
     pub async fn send_encrypted_signature(
@@ -102,13 +109,13 @@ pub struct EventLoop {
     swarm: libp2p::Swarm<Behaviour>,
     bitcoin_wallet: Arc<bitcoin::Wallet>,
     alice_peer_id: PeerId,
-    recv_quote_response: Sender<QuoteResponse>,
+    request_spot_price: Receiver<SpotPriceRequest>,
+    recv_spot_price: Sender<SpotPriceResponse>,
     start_execution_setup: Receiver<State0>,
     done_execution_setup: Sender<Result<State2>>,
     recv_transfer_proof: Sender<TransferProof>,
     dial_alice: Receiver<()>,
     conn_established: Sender<PeerId>,
-    send_quote_request: Receiver<QuoteRequest>,
     send_encrypted_signature: Receiver<EncryptedSignature>,
 }
 
@@ -147,24 +154,24 @@ impl EventLoop {
             swarm,
             alice_peer_id,
             bitcoin_wallet,
-            recv_quote_response: quote_response.sender,
+            recv_spot_price: quote_response.sender,
             start_execution_setup: start_execution_setup.receiver,
             done_execution_setup: done_execution_setup.sender,
             recv_transfer_proof: recv_transfer_proof.sender,
             conn_established: conn_established.sender,
             dial_alice: dial_alice.receiver,
-            send_quote_request: send_quote_request.receiver,
+            request_spot_price: send_quote_request.receiver,
             send_encrypted_signature: send_encrypted_signature.receiver,
         };
 
         let handle = EventLoopHandle {
-            recv_quote_response: quote_response.receiver,
+            recv_spot_price: quote_response.receiver,
             start_execution_setup: start_execution_setup.sender,
             done_execution_setup: done_execution_setup.receiver,
             recv_transfer_proof: recv_transfer_proof.receiver,
             conn_established: conn_established.receiver,
             dial_alice: dial_alice.sender,
-            send_quote_request: send_quote_request.sender,
+            request_spot_price: send_quote_request.sender,
             send_encrypted_signature: send_encrypted_signature.sender,
         };
 
@@ -179,8 +186,8 @@ impl EventLoop {
                         OutEvent::ConnectionEstablished(peer_id) => {
                             let _ = self.conn_established.send(peer_id).await;
                         }
-                        OutEvent::QuoteResponse(msg) => {
-                            let _ = self.recv_quote_response.send(msg).await;
+                        OutEvent::SpotPriceReceived(msg) => {
+                            let _ = self.recv_spot_price.send(msg).await;
                         },
                         OutEvent::ExecutionSetupDone(res) => {
                             let _ = self.done_execution_setup.send(res.map(|state|*state)).await;
@@ -213,9 +220,9 @@ impl EventLoop {
                         }
                     }
                 },
-                quote_request = self.send_quote_request.recv().fuse() =>  {
+                quote_request = self.request_spot_price.recv().fuse() =>  {
                     if let Some(quote_request) = quote_request {
-                        self.swarm.send_quote_request(self.alice_peer_id, quote_request);
+                        self.swarm.request_spot_price(self.alice_peer_id, quote_request);
                     }
                 },
                 option = self.start_execution_setup.recv().fuse() => {

swap/src/protocol/bob/quote_request.rs

@@ -1,86 +0,0 @@
-use crate::{
-    network::request_response::{CborCodec, Swap, TIMEOUT},
-    protocol::alice::QuoteResponse,
-};
-use anyhow::{anyhow, Error, Result};
-use libp2p::{
-    request_response::{
-        ProtocolSupport, RequestId, RequestResponse, RequestResponseConfig, RequestResponseEvent,
-        RequestResponseMessage,
-    },
-    NetworkBehaviour, PeerId,
-};
-use serde::{Deserialize, Serialize};
-use std::time::Duration;
-use tracing::debug;
-
-#[derive(Clone, Copy, Debug, Serialize, Deserialize)]
-pub struct QuoteRequest {
-    #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
-    pub btc_amount: bitcoin::Amount,
-}
-
-#[derive(Debug)]
-pub enum OutEvent {
-    MsgReceived(QuoteResponse),
-    Failure(Error),
-}
-
-/// A `NetworkBehaviour` that represents doing the negotiation of a swap.
-#[derive(NetworkBehaviour)]
-#[behaviour(out_event = "OutEvent", event_process = false)]
-#[allow(missing_debug_implementations)]
-pub struct Behaviour {
-    rr: RequestResponse<CborCodec<Swap, QuoteRequest, QuoteResponse>>,
-}
-
-impl Behaviour {
-    pub fn send(&mut self, alice: PeerId, quote_request: QuoteRequest) -> Result<RequestId> {
-        debug!("Requesting quote for {}", quote_request.btc_amount);
-
-        let id = self.rr.send_request(&alice, quote_request);
-
-        Ok(id)
-    }
-}
-
-impl Default for Behaviour {
-    fn default() -> Self {
-        let timeout = Duration::from_secs(TIMEOUT);
-
-        let mut config = RequestResponseConfig::default();
-        config.set_request_timeout(timeout);
-
-        Self {
-            rr: RequestResponse::new(
-                CborCodec::default(),
-                vec![(Swap, ProtocolSupport::Outbound)],
-                config,
-            ),
-        }
-    }
-}
-
-impl From<RequestResponseEvent<QuoteRequest, QuoteResponse>> for OutEvent {
-    fn from(event: RequestResponseEvent<QuoteRequest, QuoteResponse>) -> Self {
-        match event {
-            RequestResponseEvent::Message {
-                message: RequestResponseMessage::Request { .. },
-                ..
-            } => OutEvent::Failure(anyhow!("Bob should never get a request from Alice")),
-            RequestResponseEvent::Message {
-                message: RequestResponseMessage::Response { response, .. },
-                ..
-            } => OutEvent::MsgReceived(response),
-            RequestResponseEvent::InboundFailure { error, .. } => {
-                OutEvent::Failure(anyhow!("Inbound failure: {:?}", error))
-            }
-            RequestResponseEvent::OutboundFailure { error, .. } => {
-                OutEvent::Failure(anyhow!("Outbound failure: {:?}", error))
-            }
-            RequestResponseEvent::ResponseSent { .. } => {
-                OutEvent::Failure(anyhow!("Bob does not send a quote response to Alice"))
-            }
-        }
-    }
-}

swap/src/protocol/bob/swap.rs

@@ -5,7 +5,7 @@ use crate::{
     execution_params::ExecutionParams,
     monero,
     monero::InsufficientFunds,
-    protocol::bob::{self, event_loop::EventLoopHandle, state::*, QuoteRequest},
+    protocol::bob::{self, event_loop::EventLoopHandle, state::*},
 };
 use anyhow::{bail, Result};
 use async_recursion::async_recursion;
@@ -72,7 +72,7 @@ async fn run_until_internal(
 
                 event_loop_handle.dial().await?;
 
-                let state2 = request_quote_and_setup(
+                let state2 = request_price_and_setup(
                     btc_amount,
                     &mut event_loop_handle,
                     execution_params,
@@ -394,24 +394,20 @@ async fn run_until_internal(
     }
 }
 
-pub async fn request_quote_and_setup(
-    btc_amount: bitcoin::Amount,
+pub async fn request_price_and_setup(
+    btc: bitcoin::Amount,
     event_loop_handle: &mut EventLoopHandle,
     execution_params: ExecutionParams,
     bitcoin_refund_address: bitcoin::Address,
 ) -> Result<bob::state::State2> {
-    event_loop_handle
-        .send_quote_request(QuoteRequest { btc_amount })
-        .await?;
+    let xmr = event_loop_handle.request_spot_price(btc).await?;
 
-    let xmr_amount = event_loop_handle.recv_quote_response().await?.xmr_amount;
-
-    tracing::info!("Quote for {} is {}", btc_amount, xmr_amount);
+    tracing::info!("Spot price for {} is {}", btc, xmr);
 
     let state0 = State0::new(
         &mut OsRng,
-        btc_amount,
-        xmr_amount,
+        btc,
+        xmr,
         execution_params.bitcoin_cancel_timelock,
         execution_params.bitcoin_punish_timelock,
         bitcoin_refund_address,