Merge #142

142: Rename Swap amounts to Swap req/res r=D4nte a=D4nte

As per #140

Question: Do we prefer `Negotiation Request/Response` to `Swap Request/Response`?

Co-authored-by: Franck Royer <franck@coblox.tech>

swap/src/database/alice.rs

@@ -1,6 +1,3 @@
-use ::bitcoin::hashes::core::fmt::Display;
-use serde::{Deserialize, Serialize};
-
 use crate::{
     bitcoin::{EncryptedSignature, TxCancel, TxRefund},
     monero,
@@ -8,6 +5,8 @@ use crate::{
     protocol::{alice, alice::AliceState},
     SwapAmounts,
 };
+use ::bitcoin::hashes::core::fmt::Display;
+use serde::{Deserialize, Serialize};
 
 // Large enum variant is fine because this is only used for database
 // and is dropped once written in DB.

swap/src/database/bob.rs

@@ -1,10 +1,9 @@
-use ::bitcoin::hashes::core::fmt::Display;
-use serde::{Deserialize, Serialize};
-
 use crate::{
     protocol::{bob, bob::BobState},
     SwapAmounts,
 };
+use ::bitcoin::hashes::core::fmt::Display;
+use serde::{Deserialize, Serialize};
 
 #[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
 pub enum Bob {

swap/src/lib.rs

@@ -31,19 +31,6 @@ pub mod trace;
 
 pub type Never = std::convert::Infallible;
 
-/// Commands sent from Bob to the main task.
-#[derive(Clone, Copy, Debug)]
-pub enum Cmd {
-    VerifyAmounts(SwapAmounts),
-}
-
-/// Responses sent from the main task back to Bob.
-#[derive(Clone, Copy, Debug, PartialEq)]
-pub enum Rsp {
-    VerifiedAmounts,
-    Abort,
-}
-
 /// XMR/BTC swap amounts.
 #[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq)]
 // TODO(Franck): review necessity of this struct

swap/src/network/request_response.rs

@@ -8,10 +8,7 @@ use serde::{Deserialize, Serialize};
 use std::{fmt::Debug, io, marker::PhantomData};
 use tracing::debug;
 
-use crate::{
+use crate::protocol::{alice, bob};
-    protocol::{alice, bob},
-    SwapAmounts,
-};
 
 /// Time to wait for a response back once we send a request.
 pub const TIMEOUT: u64 = 3600; // One hour.
@@ -25,8 +22,7 @@ const BUF_SIZE: usize = 1024 * 1024;
 /// Messages Bob sends to Alice.
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub enum BobToAlice {
-    #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
+    SwapRequest(bob::SwapRequest),
-    AmountsFromBtc(::bitcoin::Amount),
     Message0(Box<bob::Message0>),
     Message1(bob::Message1),
     Message2(bob::Message2),
@@ -36,7 +32,7 @@ pub enum BobToAlice {
 /// Messages Alice sends to Bob.
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub enum AliceToBob {
-    Amounts(SwapAmounts),
+    SwapResponse(alice::SwapResponse),
     Message0(Box<alice::Message0>),
     Message1(Box<alice::Message1>),
     Message2(alice::Message2),
@@ -44,7 +40,7 @@ pub enum AliceToBob {
 }
 
 #[derive(Debug, Clone, Copy, Default)]
-pub struct AmountsProtocol;
+pub struct Swap;
 
 #[derive(Debug, Clone, Copy, Default)]
 pub struct Message0Protocol;
@@ -58,9 +54,9 @@ pub struct Message2Protocol;
 #[derive(Debug, Clone, Copy, Default)]
 pub struct Message3Protocol;
 
-impl ProtocolName for AmountsProtocol {
+impl ProtocolName for Swap {
     fn protocol_name(&self) -> &[u8] {
-        b"/xmr/btc/amounts/1.0.0"
+        b"/xmr/btc/swap/1.0.0"
     }
 }
 

swap/src/protocol/alice.rs

@@ -1,36 +1,40 @@
 //! Run an XMR/BTC swap in the role of Alice.
 //! Alice holds XMR and wishes receive BTC.
-use anyhow::{bail, Result};
-use libp2p::{request_response::ResponseChannel, NetworkBehaviour, PeerId};
-use tracing::{debug, info};
-
 use crate::{
-    bitcoin, database, monero,
+    bitcoin,
+    config::Config,
+    database,
+    database::Database,
+    monero,
     network::{
         peer_tracker::{self, PeerTracker},
         request_response::AliceToBob,
+        transport::build,
         Seed as NetworkSeed,
     },
     protocol::bob,
+    seed::Seed,
     SwapAmounts,
 };
+use anyhow::{bail, Result};
+use libp2p::{
+    core::Multiaddr, identity::Keypair, request_response::ResponseChannel, NetworkBehaviour, PeerId,
+};
+use rand::rngs::OsRng;
+use std::{path::PathBuf, sync::Arc};
+use tracing::{debug, info};
+use uuid::Uuid;
 
 pub use self::{
-    amounts::*,
     event_loop::{EventLoop, EventLoopHandle},
     message0::Message0,
     message1::Message1,
     message2::Message2,
     state::*,
     swap::{run, run_until},
+    swap_response::*,
 };
-use crate::{config::Config, database::Database, network::transport::build, seed::Seed};
-use libp2p::{core::Multiaddr, identity::Keypair};
-use rand::rngs::OsRng;
-use std::{path::PathBuf, sync::Arc};
-use uuid::Uuid;
 
-mod amounts;
 pub mod event_loop;
 mod message0;
 mod message1;
@@ -39,6 +43,7 @@ mod message3;
 pub mod state;
 mod steps;
 pub mod swap;
+mod swap_response;
 
 pub struct Swap {
     pub state: AliceState,
@@ -217,8 +222,9 @@ pub enum OutEvent {
     ConnectionEstablished(PeerId),
     // TODO (Franck): Change this to get both amounts so parties can verify the amounts are
     // expected early on.
-    Request(Box<amounts::OutEvent>), /* Not-uniform with Bob on purpose, ready for adding Xmr
+    Request(Box<swap_response::OutEvent>), /* Not-uniform with Bob on purpose, ready for adding
-                                      * event. */
+                                            * Xmr
+                                            * event. */
     Message0 {
         msg: Box<bob::Message0>,
         channel: ResponseChannel<AliceToBob>,
@@ -244,8 +250,8 @@ impl From<peer_tracker::OutEvent> for OutEvent {
     }
 }
 
-impl From<amounts::OutEvent> for OutEvent {
+impl From<swap_response::OutEvent> for OutEvent {
-    fn from(event: amounts::OutEvent) -> Self {
+    fn from(event: swap_response::OutEvent) -> Self {
         OutEvent::Request(Box::new(event))
     }
 }
@@ -291,7 +297,7 @@ impl From<message3::OutEvent> for OutEvent {
 #[allow(missing_debug_implementations)]
 pub struct Behaviour {
     pt: PeerTracker,
-    amounts: Amounts,
+    amounts: swap_response::Behaviour,
     message0: message0::Behaviour,
     message1: message1::Behaviour,
     message2: message2::Behaviour,
@@ -300,9 +306,12 @@ pub struct Behaviour {
 
 impl Behaviour {
     /// Alice always sends her messages as a response to a request from Bob.
-    pub fn send_amounts(&mut self, channel: ResponseChannel<AliceToBob>, amounts: SwapAmounts) {
+    pub fn send_swap_response(
-        let msg = AliceToBob::Amounts(amounts);
+        &mut self,
-        self.amounts.send(channel, msg);
+        channel: ResponseChannel<AliceToBob>,
+        swap_response: SwapResponse,
+    ) {
+        self.amounts.send(channel, swap_response);
         info!("Sent amounts response");
     }
 

swap/src/protocol/alice/event_loop.rs

@@ -9,10 +9,9 @@ use crate::{
     network::{request_response::AliceToBob, transport::SwapTransport, TokioExecutor},
     protocol::{
         alice,
-        alice::{Behaviour, OutEvent},
+        alice::{Behaviour, OutEvent, SwapResponse},
         bob,
     },
-    SwapAmounts,
 };
 
 #[allow(missing_debug_implementations)]
@@ -40,9 +39,9 @@ pub struct EventLoopHandle {
     msg1: Receiver<(bob::Message1, ResponseChannel<AliceToBob>)>,
     msg2: Receiver<(bob::Message2, ResponseChannel<AliceToBob>)>,
     msg3: Receiver<bob::Message3>,
-    request: Receiver<crate::protocol::alice::amounts::OutEvent>,
+    request: Receiver<crate::protocol::alice::swap_response::OutEvent>,
     conn_established: Receiver<PeerId>,
-    send_amounts: Sender<(ResponseChannel<AliceToBob>, SwapAmounts)>,
+    send_swap_response: Sender<(ResponseChannel<AliceToBob>, SwapResponse)>,
     send_msg0: Sender<(ResponseChannel<AliceToBob>, alice::Message0)>,
     send_msg1: Sender<(ResponseChannel<AliceToBob>, alice::Message1)>,
     send_msg2: Sender<(ResponseChannel<AliceToBob>, alice::Message2)>,
@@ -84,19 +83,24 @@ impl EventLoopHandle {
             .ok_or_else(|| anyhow!("Failed to receive Bitcoin encrypted signature from Bob"))
     }
 
-    pub async fn recv_request(&mut self) -> Result<crate::protocol::alice::amounts::OutEvent> {
+    pub async fn recv_request(
+        &mut self,
+    ) -> Result<crate::protocol::alice::swap_response::OutEvent> {
         self.request
             .recv()
             .await
             .ok_or_else(|| anyhow!("Failed to receive amounts request from Bob"))
     }
 
-    pub async fn send_amounts(
+    pub async fn send_swap_response(
         &mut self,
         channel: ResponseChannel<AliceToBob>,
-        amounts: SwapAmounts,
+        swap_response: SwapResponse,
     ) -> Result<()> {
-        let _ = self.send_amounts.send((channel, amounts)).await?;
+        let _ = self
+            .send_swap_response
+            .send((channel, swap_response))
+            .await?;
         Ok(())
     }
 
@@ -135,9 +139,9 @@ pub struct EventLoop {
     msg1: Sender<(bob::Message1, ResponseChannel<AliceToBob>)>,
     msg2: Sender<(bob::Message2, ResponseChannel<AliceToBob>)>,
     msg3: Sender<bob::Message3>,
-    request: Sender<crate::protocol::alice::amounts::OutEvent>,
+    request: Sender<crate::protocol::alice::swap_response::OutEvent>,
     conn_established: Sender<PeerId>,
-    send_amounts: Receiver<(ResponseChannel<AliceToBob>, SwapAmounts)>,
+    send_swap_response: Receiver<(ResponseChannel<AliceToBob>, SwapResponse)>,
     send_msg0: Receiver<(ResponseChannel<AliceToBob>, alice::Message0)>,
     send_msg1: Receiver<(ResponseChannel<AliceToBob>, alice::Message1)>,
     send_msg2: Receiver<(ResponseChannel<AliceToBob>, alice::Message2)>,
@@ -165,7 +169,7 @@ impl EventLoop {
         let msg3 = Channels::new();
         let request = Channels::new();
         let conn_established = Channels::new();
-        let send_amounts = Channels::new();
+        let send_swap_response = Channels::new();
         let send_msg0 = Channels::new();
         let send_msg1 = Channels::new();
         let send_msg2 = Channels::new();
@@ -178,7 +182,7 @@ impl EventLoop {
             msg3: msg3.sender,
             request: request.sender,
             conn_established: conn_established.sender,
-            send_amounts: send_amounts.receiver,
+            send_swap_response: send_swap_response.receiver,
             send_msg0: send_msg0.receiver,
             send_msg1: send_msg1.receiver,
             send_msg2: send_msg2.receiver,
@@ -191,7 +195,7 @@ impl EventLoop {
             msg3: msg3.receiver,
             request: request.receiver,
             conn_established: conn_established.receiver,
-            send_amounts: send_amounts.sender,
+            send_swap_response: send_swap_response.sender,
             send_msg0: send_msg0.sender,
             send_msg1: send_msg1.sender,
             send_msg2: send_msg2.sender,
@@ -225,9 +229,9 @@ impl EventLoop {
                         }
                     }
                 },
-                amounts = self.send_amounts.next().fuse() => {
+                swap_response = self.send_swap_response.next().fuse() => {
-                    if let Some((channel, amounts)) = amounts  {
+                    if let Some((channel, swap_response)) = swap_response  {
-                        self.swarm.send_amounts(channel, amounts);
+                        self.swarm.send_swap_response(channel, swap_response);
                     }
                 },
                 msg0 = self.send_msg0.next().fuse() => {

swap/src/protocol/alice/state.rs

@@ -268,7 +268,6 @@ impl State2 {
             S_b_monero: self.S_b_monero,
             S_b_bitcoin: self.S_b_bitcoin,
             v: self.v,
-            // TODO(Franck): Review if these amounts are actually needed
             btc: self.btc,
             xmr: self.xmr,
             cancel_timelock: self.cancel_timelock,
@@ -323,7 +322,6 @@ impl State3 {
             S_b_monero: self.S_b_monero,
             S_b_bitcoin: self.S_b_bitcoin,
             v: self.v,
-            btc: self.btc,
             xmr: self.xmr,
             cancel_timelock: self.cancel_timelock,
             punish_timelock: self.punish_timelock,
@@ -370,8 +368,6 @@ pub struct State4 {
     S_b_monero: monero::PublicKey,
     S_b_bitcoin: bitcoin::PublicKey,
     v: monero::PrivateViewKey,
-    #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
-    btc: bitcoin::Amount,
     xmr: monero::Amount,
     cancel_timelock: Timelock,
     punish_timelock: Timelock,
@@ -404,8 +400,6 @@ impl State4 {
             S_b_monero: self.S_b_monero,
             S_b_bitcoin: self.S_b_bitcoin,
             v: self.v,
-            btc: self.btc,
-            xmr: self.xmr,
             cancel_timelock: self.cancel_timelock,
             punish_timelock: self.punish_timelock,
             refund_address: self.refund_address,
@@ -467,9 +461,6 @@ pub struct State5 {
     S_b_monero: monero::PublicKey,
     S_b_bitcoin: bitcoin::PublicKey,
     v: monero::PrivateViewKey,
-    #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
-    btc: bitcoin::Amount,
-    xmr: monero::Amount,
     cancel_timelock: Timelock,
     punish_timelock: Timelock,
     refund_address: bitcoin::Address,
@@ -499,8 +490,6 @@ impl State5 {
             S_b_monero: self.S_b_monero,
             S_b_bitcoin: self.S_b_bitcoin,
             v: self.v,
-            btc: self.btc,
-            xmr: self.xmr,
             cancel_timelock: self.cancel_timelock,
             punish_timelock: self.punish_timelock,
             refund_address: self.refund_address,
@@ -557,9 +546,6 @@ pub struct State6 {
     S_b_monero: monero::PublicKey,
     S_b_bitcoin: bitcoin::PublicKey,
     v: monero::PrivateViewKey,
-    #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
-    btc: bitcoin::Amount,
-    xmr: monero::Amount,
     cancel_timelock: Timelock,
     punish_timelock: Timelock,
     refund_address: bitcoin::Address,

swap/src/protocol/alice/steps.rs

@@ -1,4 +1,4 @@
-use anyhow::{bail, Context, Result};
+use anyhow::{Context, Result};
 use ecdsa_fun::{adaptor::Adaptor, nonce::Deterministic};
 use futures::{
     future::{select, Either},
@@ -24,13 +24,16 @@ use crate::{
     monero,
     monero::Transfer,
     network::request_response::AliceToBob,
-    protocol::{alice, alice::event_loop::EventLoopHandle},
+    protocol::{
+        alice,
+        alice::{event_loop::EventLoopHandle, SwapResponse},
+    },
     SwapAmounts,
 };
 
 pub async fn negotiate(
     state0: alice::State0,
-    amounts: SwapAmounts,
+    xmr_amount: monero::Amount,
     event_loop_handle: &mut EventLoopHandle,
     config: Config,
 ) -> Result<(ResponseChannel<AliceToBob>, alice::State3)> {
@@ -46,18 +49,10 @@ pub async fn negotiate(
 
     let event = timeout(config.bob_time_to_act, event_loop_handle.recv_request())
         .await
-        .context("Failed to receive amounts from Bob")??;
+        .context("Failed to receive swap request from Bob")??;
-
-    if event.btc != amounts.btc {
-        bail!(
-            "Bob proposed a different amount; got {}, expected: {}",
-            event.btc,
-            amounts.btc
-        );
-    }
 
     event_loop_handle
-        .send_amounts(event.channel, amounts)
+        .send_swap_response(event.channel, SwapResponse { xmr_amount })
         .await?;
 
     let (bob_message0, channel) =

swap/src/protocol/alice/swap.rs

@@ -105,7 +105,7 @@ async fn run_until_internal(
         match state {
             AliceState::Started { amounts, state0 } => {
                 let (channel, state3) =
-                    negotiate(state0, amounts, &mut event_loop_handle, config).await?;
+                    negotiate(state0, amounts.xmr, &mut event_loop_handle, config).await?;
 
                 let state = AliceState::Negotiated {
                     channel: Some(channel),

swap/src/protocol/alice/swap_response.rs

@@ -6,6 +6,7 @@ use libp2p::{
     swarm::{NetworkBehaviourAction, NetworkBehaviourEventProcess, PollParameters},
     NetworkBehaviour,
 };
+use serde::{Deserialize, Serialize};
 use std::{
     collections::VecDeque,
     task::{Context, Poll},
@@ -14,29 +15,37 @@ use std::{
 use tracing::{debug, error};
 
 use crate::{
-    network::request_response::{AliceToBob, AmountsProtocol, BobToAlice, Codec, TIMEOUT},
+    monero,
-    protocol::alice::amounts,
+    network::request_response::{AliceToBob, BobToAlice, Codec, Swap, TIMEOUT},
+    protocol::bob,
 };
 
 #[derive(Debug)]
 pub struct OutEvent {
-    pub btc: ::bitcoin::Amount,
+    pub msg: bob::SwapRequest,
     pub channel: ResponseChannel<AliceToBob>,
 }
 
-/// A `NetworkBehaviour` that represents getting the amounts of an XMR/BTC swap.
+#[derive(Copy, Clone, Debug, Serialize, Deserialize)]
+pub struct SwapResponse {
+    pub xmr_amount: monero::Amount,
+}
+
+/// A `NetworkBehaviour` that represents negotiate a swap using Swap
+/// request/response.
 #[derive(NetworkBehaviour)]
 #[behaviour(out_event = "OutEvent", poll_method = "poll")]
 #[allow(missing_debug_implementations)]
-pub struct Amounts {
+pub struct Behaviour {
-    rr: RequestResponse<Codec<AmountsProtocol>>,
+    rr: RequestResponse<Codec<Swap>>,
     #[behaviour(ignore)]
     events: VecDeque<OutEvent>,
 }
 
-impl Amounts {
+impl Behaviour {
     /// Alice always sends her messages as a response to a request from Bob.
-    pub fn send(&mut self, channel: ResponseChannel<AliceToBob>, msg: AliceToBob) {
+    pub fn send(&mut self, channel: ResponseChannel<AliceToBob>, msg: SwapResponse) {
+        let msg = AliceToBob::SwapResponse(msg);
         self.rr.send_response(channel, msg);
     }
 
@@ -44,7 +53,7 @@ impl Amounts {
         &mut self,
         _: &mut Context<'_>,
         _: &mut impl PollParameters,
-    ) -> Poll<NetworkBehaviourAction<RequestProtocol<Codec<AmountsProtocol>>, OutEvent>> {
+    ) -> Poll<NetworkBehaviourAction<RequestProtocol<Codec<Swap>>, OutEvent>> {
         if let Some(event) = self.events.pop_front() {
             return Poll::Ready(NetworkBehaviourAction::GenerateEvent(event));
         }
@@ -53,7 +62,7 @@ impl Amounts {
     }
 }
 
-impl Default for Amounts {
+impl Default for Behaviour {
     fn default() -> Self {
         let timeout = Duration::from_secs(TIMEOUT);
 
@@ -63,7 +72,7 @@ impl Default for Amounts {
         Self {
             rr: RequestResponse::new(
                 Codec::default(),
-                vec![(AmountsProtocol, ProtocolSupport::Full)],
+                vec![(Swap, ProtocolSupport::Full)],
                 config,
             ),
             events: Default::default(),
@@ -71,7 +80,7 @@ impl Default for Amounts {
     }
 }
 
-impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>> for Amounts {
+impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>> for Behaviour {
     fn inject_event(&mut self, event: RequestResponseEvent<BobToAlice, AliceToBob>) {
         match event {
             RequestResponseEvent::Message {
@@ -81,9 +90,9 @@ impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>>
                     },
                 ..
             } => {
-                if let BobToAlice::AmountsFromBtc(btc) = request {
+                if let BobToAlice::SwapRequest(msg) = request {
-                    debug!("Received amounts request");
+                    debug!("Received swap request");
-                    self.events.push_back(amounts::OutEvent { btc, channel })
+                    self.events.push_back(OutEvent { msg, channel })
                 }
             }
             RequestResponseEvent::Message {

swap/src/protocol/bob.rs

@@ -1,20 +1,28 @@
 //! Run an XMR/BTC swap in the role of Bob.
 //! Bob holds BTC and wishes receive XMR.
-use anyhow::{bail, Result};
-use libp2p::{core::Multiaddr, NetworkBehaviour, PeerId};
-use tracing::{debug, info};
-
 use crate::{
     bitcoin,
     bitcoin::EncryptedSignature,
-    database, monero, network,
+    config::Config,
-    network::peer_tracker::{self, PeerTracker},
+    database,
+    database::Database,
+    monero, network,
+    network::{
+        peer_tracker::{self, PeerTracker},
+        transport::build,
+    },
     protocol::{alice, bob},
+    seed::Seed,
     SwapAmounts,
 };
+use anyhow::{bail, Result};
+use libp2p::{core::Multiaddr, identity::Keypair, NetworkBehaviour, PeerId};
+use rand::rngs::OsRng;
+use std::{path::PathBuf, sync::Arc};
+use tracing::{debug, info};
+use uuid::Uuid;
 
 pub use self::{
-    amounts::*,
     event_loop::{EventLoop, EventLoopHandle},
     message0::Message0,
     message1::Message1,
@@ -22,14 +30,9 @@ pub use self::{
     message3::Message3,
     state::*,
     swap::{run, run_until},
+    swap_request::*,
 };
-use crate::{config::Config, database::Database, network::transport::build, seed::Seed};
-use libp2p::identity::Keypair;
-use rand::rngs::OsRng;
-use std::{path::PathBuf, sync::Arc};
-use uuid::Uuid;
 
-mod amounts;
 pub mod event_loop;
 mod message0;
 mod message1;
@@ -37,6 +40,7 @@ mod message2;
 mod message3;
 pub mod state;
 pub mod swap;
+mod swap_request;
 
 pub struct Swap {
     pub state: BobState,
@@ -204,7 +208,7 @@ impl Builder {
 #[derive(Debug, Clone)]
 pub enum OutEvent {
     ConnectionEstablished(PeerId),
-    Amounts(SwapAmounts),
+    SwapResponse(alice::SwapResponse),
     Message0(Box<alice::Message0>),
     Message1(Box<alice::Message1>),
     Message2(alice::Message2),
@@ -221,11 +225,9 @@ impl From<peer_tracker::OutEvent> for OutEvent {
     }
 }
 
-impl From<amounts::OutEvent> for OutEvent {
+impl From<swap_request::OutEvent> for OutEvent {
-    fn from(event: amounts::OutEvent) -> Self {
+    fn from(event: swap_request::OutEvent) -> Self {
-        match event {
+        OutEvent::SwapResponse(event.swap_response)
-            amounts::OutEvent::Amounts(amounts) => OutEvent::Amounts(amounts),
-        }
     }
 }
 
@@ -267,7 +269,7 @@ impl From<message3::OutEvent> for OutEvent {
 #[allow(missing_debug_implementations)]
 pub struct Behaviour {
     pt: PeerTracker,
-    amounts: Amounts,
+    swap_request: swap_request::Behaviour,
     message0: message0::Behaviour,
     message1: message1::Behaviour,
     message2: message2::Behaviour,
@@ -275,11 +277,10 @@ pub struct Behaviour {
 }
 
 impl Behaviour {
-    /// Sends a message to Alice to get current amounts based on `btc`.
+    /// Sends a swap request to Alice to negotiate the swap.
-    pub fn request_amounts(&mut self, alice: PeerId, btc: u64) {
+    pub fn send_swap_request(&mut self, alice: PeerId, swap_request: SwapRequest) {
-        let btc = ::bitcoin::Amount::from_sat(btc);
+        let _id = self.swap_request.send(alice.clone(), swap_request);
-        let _id = self.amounts.request_amounts(alice.clone(), btc);
+        info!("Requesting swap from: {}", alice);
-        info!("Requesting amounts from: {}", alice);
     }
 
     /// Sends Bob's first message to Alice.

swap/src/protocol/bob/event_loop.rs

@@ -1,3 +1,12 @@
+use crate::{
+    bitcoin::EncryptedSignature,
+    network::{transport::SwapTransport, TokioExecutor},
+    protocol::{
+        alice,
+        alice::SwapResponse,
+        bob::{self, Behaviour, OutEvent, SwapRequest},
+    },
+};
 use anyhow::{anyhow, Result};
 use futures::FutureExt;
 use libp2p::{core::Multiaddr, PeerId};
@@ -7,15 +16,6 @@ use tokio::{
 };
 use tracing::{debug, error, info};
 
-use crate::{
-    bitcoin::EncryptedSignature,
-    network::{transport::SwapTransport, TokioExecutor},
-    protocol::{
-        alice,
-        bob::{self, Behaviour, OutEvent},
-    },
-};
-
 #[derive(Debug)]
 pub struct Channels<T> {
     sender: Sender<T>,
@@ -37,12 +37,13 @@ impl<T> Default for Channels<T> {
 
 #[derive(Debug)]
 pub struct EventLoopHandle {
+    swap_response: Receiver<SwapResponse>,
     msg0: Receiver<alice::Message0>,
     msg1: Receiver<alice::Message1>,
     msg2: Receiver<alice::Message2>,
-    request_amounts: Sender<::bitcoin::Amount>,
     conn_established: Receiver<PeerId>,
     dial_alice: Sender<()>,
+    send_swap_request: Sender<SwapRequest>,
     send_msg0: Sender<bob::Message0>,
     send_msg1: Sender<bob::Message1>,
     send_msg2: Sender<bob::Message2>,
@@ -50,25 +51,32 @@ pub struct EventLoopHandle {
 }
 
 impl EventLoopHandle {
+    pub async fn recv_swap_response(&mut self) -> Result<SwapResponse> {
+        self.swap_response
+            .recv()
+            .await
+            .ok_or_else(|| anyhow!("Failed to receive swap response from Alice"))
+    }
+
     pub async fn recv_message0(&mut self) -> Result<alice::Message0> {
         self.msg0
             .recv()
             .await
-            .ok_or_else(|| anyhow!("Failed to receive message 0 from Bob"))
+            .ok_or_else(|| anyhow!("Failed to receive message 0 from Alice"))
     }
 
     pub async fn recv_message1(&mut self) -> Result<alice::Message1> {
         self.msg1
             .recv()
             .await
-            .ok_or_else(|| anyhow!("Failed to receive message 1 from Bob"))
+            .ok_or_else(|| anyhow!("Failed to receive message 1 from Alice"))
     }
 
     pub async fn recv_message2(&mut self) -> Result<alice::Message2> {
         self.msg2
             .recv()
             .await
-            .ok_or_else(|| anyhow!("Failed o receive message 2 from Bob"))
+            .ok_or_else(|| anyhow!("Failed o receive message 2 from Alice"))
     }
 
     /// Dials other party and wait for the connection to be established.
@@ -85,8 +93,8 @@ impl EventLoopHandle {
         Ok(())
     }
 
-    pub async fn request_amounts(&mut self, btc_amount: ::bitcoin::Amount) -> Result<()> {
+    pub async fn send_swap_request(&mut self, swap_request: SwapRequest) -> Result<()> {
-        let _ = self.request_amounts.send(btc_amount).await?;
+        let _ = self.send_swap_request.send(swap_request).await?;
         Ok(())
     }
 
@@ -115,12 +123,13 @@ impl EventLoopHandle {
 pub struct EventLoop {
     swarm: libp2p::Swarm<Behaviour>,
     alice_peer_id: PeerId,
+    swap_response: Sender<SwapResponse>,
     msg0: Sender<alice::Message0>,
     msg1: Sender<alice::Message1>,
     msg2: Sender<alice::Message2>,
     conn_established: Sender<PeerId>,
-    request_amounts: Receiver<::bitcoin::Amount>,
     dial_alice: Receiver<()>,
+    send_swap_request: Receiver<SwapRequest>,
     send_msg0: Receiver<bob::Message0>,
     send_msg1: Receiver<bob::Message1>,
     send_msg2: Receiver<bob::Message2>,
@@ -143,12 +152,13 @@ impl EventLoop {
 
         swarm.add_address(alice_peer_id.clone(), alice_addr);
 
-        let amounts = Channels::new();
+        let swap_response = Channels::new();
         let msg0 = Channels::new();
         let msg1 = Channels::new();
         let msg2 = Channels::new();
         let conn_established = Channels::new();
         let dial_alice = Channels::new();
+        let send_swap_request = Channels::new();
         let send_msg0 = Channels::new();
         let send_msg1 = Channels::new();
         let send_msg2 = Channels::new();
@@ -157,12 +167,13 @@ impl EventLoop {
         let event_loop = EventLoop {
             swarm,
             alice_peer_id,
-            request_amounts: amounts.receiver,
+            swap_response: swap_response.sender,
             msg0: msg0.sender,
             msg1: msg1.sender,
             msg2: msg2.sender,
             conn_established: conn_established.sender,
             dial_alice: dial_alice.receiver,
+            send_swap_request: send_swap_request.receiver,
             send_msg0: send_msg0.receiver,
             send_msg1: send_msg1.receiver,
             send_msg2: send_msg2.receiver,
@@ -170,12 +181,13 @@ impl EventLoop {
         };
 
         let handle = EventLoopHandle {
-            request_amounts: amounts.sender,
+            swap_response: swap_response.receiver,
             msg0: msg0.receiver,
             msg1: msg1.receiver,
             msg2: msg2.receiver,
             conn_established: conn_established.receiver,
             dial_alice: dial_alice.sender,
+            send_swap_request: send_swap_request.sender,
             send_msg0: send_msg0.sender,
             send_msg1: send_msg1.sender,
             send_msg2: send_msg2.sender,
@@ -193,7 +205,9 @@ impl EventLoop {
                         OutEvent::ConnectionEstablished(peer_id) => {
                             let _ = self.conn_established.send(peer_id).await;
                         }
-                        OutEvent::Amounts(_amounts) => info!("Amounts received from Alice"),
+                        OutEvent::SwapResponse(msg) => {
+                            let _ = self.swap_response.send(msg).await;
+                        },
                         OutEvent::Message0(msg) => {
                             let _ = self.msg0.send(*msg).await;
                         }
@@ -222,9 +236,9 @@ impl EventLoop {
                         }
                     }
                 },
-                amounts = self.request_amounts.next().fuse() =>  {
+                swap_request = self.send_swap_request.next().fuse() =>  {
-                    if let Some(btc_amount) = amounts {
+                    if let Some(swap_request) = swap_request {
-                        self.swarm.request_amounts(self.alice_peer_id.clone(), btc_amount.as_sat());
+                        self.swarm.send_swap_request(self.alice_peer_id.clone(), swap_request);
                     }
                 },
 

swap/src/protocol/bob/swap.rs

@@ -11,7 +11,7 @@ use crate::{
     config::Config,
     database::{Database, Swap},
     monero,
-    protocol::bob::{self, event_loop::EventLoopHandle, state::*},
+    protocol::bob::{self, event_loop::EventLoopHandle, state::*, SwapRequest},
     ExpiredTimelocks, SwapAmounts,
 };
 
@@ -373,7 +373,15 @@ where
     R: RngCore + CryptoRng + Send,
 {
     tracing::trace!("Starting negotiate");
-    swarm.request_amounts(amounts.btc).await?;
+    swarm
+        .send_swap_request(SwapRequest {
+            btc_amount: amounts.btc,
+        })
+        .await?;
+
+    // TODO: Use this once Bob's CLI is modified to only pass xmr amount in
+    // argument.
+    let _swap_response = swarm.recv_swap_response().await?;
 
     swarm.send_message0(state0.next_message(&mut rng)).await?;
     let msg0 = swarm.recv_message0().await?;

swap/src/protocol/bob/swap_request.rs

@@ -1,3 +1,7 @@
+use crate::{
+    network::request_response::{AliceToBob, BobToAlice, Codec, Swap, TIMEOUT},
+    protocol::alice::SwapResponse,
+};
 use anyhow::Result;
 use libp2p::{
     request_response::{
@@ -7,6 +11,7 @@ use libp2p::{
     swarm::{NetworkBehaviourAction, NetworkBehaviourEventProcess, PollParameters},
     NetworkBehaviour, PeerId,
 };
+use serde::{Deserialize, Serialize};
 use std::{
     collections::VecDeque,
     task::{Context, Poll},
@@ -14,29 +19,30 @@ use std::{
 };
 use tracing::{debug, error};
 
-use crate::{
+#[derive(Clone, Debug, Serialize, Deserialize)]
-    network::request_response::{AliceToBob, AmountsProtocol, BobToAlice, Codec, TIMEOUT},
+pub struct SwapRequest {
-    SwapAmounts,
+    #[serde(with = "::bitcoin::util::amount::serde::as_sat")]
-};
+    pub btc_amount: bitcoin::Amount,
-
-#[derive(Copy, Clone, Debug)]
-pub enum OutEvent {
-    Amounts(SwapAmounts),
 }
 
-/// A `NetworkBehaviour` that represents getting the amounts of an XMR/BTC swap.
+#[derive(Copy, Clone, Debug)]
+pub struct OutEvent {
+    pub swap_response: SwapResponse,
+}
+
+/// A `NetworkBehaviour` that represents doing the negotiation of a swap.
 #[derive(NetworkBehaviour)]
 #[behaviour(out_event = "OutEvent", poll_method = "poll")]
 #[allow(missing_debug_implementations)]
-pub struct Amounts {
+pub struct Behaviour {
-    rr: RequestResponse<Codec<AmountsProtocol>>,
+    rr: RequestResponse<Codec<Swap>>,
     #[behaviour(ignore)]
     events: VecDeque<OutEvent>,
 }
 
-impl Amounts {
+impl Behaviour {
-    pub fn request_amounts(&mut self, alice: PeerId, btc: ::bitcoin::Amount) -> Result<RequestId> {
+    pub fn send(&mut self, alice: PeerId, swap_request: SwapRequest) -> Result<RequestId> {
-        let msg = BobToAlice::AmountsFromBtc(btc);
+        let msg = BobToAlice::SwapRequest(swap_request);
         let id = self.rr.send_request(&alice, msg);
 
         Ok(id)
@@ -46,7 +52,7 @@ impl Amounts {
         &mut self,
         _: &mut Context<'_>,
         _: &mut impl PollParameters,
-    ) -> Poll<NetworkBehaviourAction<RequestProtocol<Codec<AmountsProtocol>>, OutEvent>> {
+    ) -> Poll<NetworkBehaviourAction<RequestProtocol<Codec<Swap>>, OutEvent>> {
         if let Some(event) = self.events.pop_front() {
             return Poll::Ready(NetworkBehaviourAction::GenerateEvent(event));
         }
@@ -55,7 +61,7 @@ impl Amounts {
     }
 }
 
-impl Default for Amounts {
+impl Default for Behaviour {
     fn default() -> Self {
         let timeout = Duration::from_secs(TIMEOUT);
 
@@ -65,7 +71,7 @@ impl Default for Amounts {
         Self {
             rr: RequestResponse::new(
                 Codec::default(),
-                vec![(AmountsProtocol, ProtocolSupport::Full)],
+                vec![(Swap, ProtocolSupport::Full)],
                 config,
             ),
             events: Default::default(),
@@ -73,7 +79,7 @@ impl Default for Amounts {
     }
 }
 
-impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>> for Amounts {
+impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>> for Behaviour {
     fn inject_event(&mut self, event: RequestResponseEvent<BobToAlice, AliceToBob>) {
         match event {
             RequestResponseEvent::Message {
@@ -84,9 +90,9 @@ impl NetworkBehaviourEventProcess<RequestResponseEvent<BobToAlice, AliceToBob>>
                 message: RequestResponseMessage::Response { response, .. },
                 ..
             } => {
-                if let AliceToBob::Amounts(p) = response {
+                if let AliceToBob::SwapResponse(swap_response) = response {
-                    debug!("Received amounts response");
+                    debug!("Received swap response");
-                    self.events.push_back(OutEvent::Amounts(p));
+                    self.events.push_back(OutEvent { swap_response });
                 }
             }
             RequestResponseEvent::InboundFailure { error, .. } => {