Alice resumes swaps

.github/workflows/ci.yml

@@ -110,10 +110,12 @@ jobs:
             happy_path,
             happy_path_restart_bob_after_xmr_locked,
             happy_path_restart_bob_before_xmr_locked,
+            happy_path_restart_alice_after_xmr_locked,
             bob_refunds_using_cancel_and_refund_command,
             bob_refunds_using_cancel_and_refund_command_timelock_not_expired,
             bob_refunds_using_cancel_and_refund_command_timelock_not_expired_force,
-            punish
+            punish,
+            alice_punishes_after_restart_punish_timelock_expired
         ]
     runs-on: ubuntu-latest
     steps:

CHANGELOG.md

@@ -15,6 +15,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - A changelog file.
+- Automatic resume of unfinished swaps for the `asb` upon startup.
+  Unfinished swaps from earlier versions will be skipped.
 
 ### Fixed
 

bors.toml

@@ -8,9 +8,11 @@ status = [
     "test (macos-latest)",
     "docker_tests (happy_path)",
     "docker_tests (happy_path_restart_bob_after_xmr_locked)",
+    "docker_tests (happy_path_restart_alice_after_xmr_locked)",
     "docker_tests (happy_path_restart_bob_before_xmr_locked)",
     "docker_tests (bob_refunds_using_cancel_and_refund_command)",
     "docker_tests (bob_refunds_using_cancel_and_refund_command_timelock_not_expired_force)",
     "docker_tests (bob_refunds_using_cancel_and_refund_command_timelock_not_expired)",
-    "docker_tests (punish)"
+    "docker_tests (punish)",
+    "docker_tests (alice_punishes_after_restart_punish_timelock_expired)"
 ]

swap/src/asb/fixed_rate.rs

@@ -1,6 +1,6 @@
 use crate::asb::Rate;
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Copy, Debug)]
 pub struct FixedRate(Rate);
 
 impl FixedRate {

swap/src/protocol/alice/event_loop.rs

@@ -84,6 +84,43 @@ where
         // terminate forever.
         self.send_transfer_proof.push(future::pending().boxed());
 
+        let unfinished_swaps = match self.db.unfinished_alice() {
+            Ok(unfinished_swaps) => unfinished_swaps,
+            Err(_) => {
+                tracing::error!("Failed to load unfinished swaps");
+                return;
+            }
+        };
+
+        for (swap_id, state) in unfinished_swaps {
+            let peer_id = match self.db.get_peer_id(swap_id) {
+                Ok(peer_id) => peer_id,
+                Err(_) => {
+                    tracing::warn!(%swap_id, "Resuming swap skipped because no peer-id found for swap in database");
+                    continue;
+                }
+            };
+
+            let handle = self.new_handle(peer_id);
+
+            let swap = Swap {
+                event_loop_handle: handle,
+                bitcoin_wallet: self.bitcoin_wallet.clone(),
+                monero_wallet: self.monero_wallet.clone(),
+                env_config: self.env_config,
+                db: self.db.clone(),
+                state: state.into(),
+                swap_id,
+            };
+
+            match self.swap_sender.send(swap).await {
+                Ok(_) => tracing::info!(%swap_id, "Resuming swap"),
+                Err(_) => {
+                    tracing::warn!(%swap_id, "Failed to resume swap because receiver has been dropped")
+                }
+            }
+        }
+
         loop {
             tokio::select! {
                 swarm_event = self.swarm.next_event() => {
@@ -264,10 +301,20 @@ where
             swap_id,
         };
 
+        // TODO: Consider adding separate components for start/rsume of swaps
+
+        // swaps save peer id so we can resume
+        match self.db.insert_peer_id(swap_id, bob_peer_id).await {
+            Ok(_) => {
                 if let Err(error) = self.swap_sender.send(swap).await {
                     tracing::warn!(%swap_id, "Swap cannot be spawned: {}", error);
                 }
             }
+            Err(error) => {
+                tracing::warn!(%swap_id, "Unable to save peer-id, swap cannot be spawned: {}", error);
+            }
+        }
+    }
 
     /// Create a new [`EventLoopHandle`] that is scoped for communication with
     /// the given peer.

swap/tests/alice_punishes_after_restart_punish_timelock_expired.rs

@@ -0,0 +1,62 @@
+pub mod harness;
+
+use harness::alice_run_until::is_xmr_lock_transaction_sent;
+use harness::bob_run_until::is_btc_locked;
+use harness::FastPunishConfig;
+use swap::protocol::alice::AliceState;
+use swap::protocol::bob::BobState;
+use swap::protocol::{alice, bob};
+
+/// Bob locks Btc and Alice locks Xmr. Bob does not act; he fails to send Alice
+/// the encsig and fail to refund or redeem. Alice punishes.
+#[tokio::test]
+async fn alice_punishes_after_restart_if_punish_timelock_expired() {
+    harness::setup_test(FastPunishConfig, |mut ctx| async move {
+        let (bob_swap, bob_join_handle) = ctx.bob_swap().await;
+        let bob_swap = tokio::spawn(bob::run_until(bob_swap, is_btc_locked));
+
+        let alice_swap = ctx.alice_next_swap().await;
+        let alice_bitcoin_wallet = alice_swap.bitcoin_wallet.clone();
+
+        let alice_swap = tokio::spawn(alice::run_until(alice_swap, is_xmr_lock_transaction_sent));
+
+        let bob_state = bob_swap.await??;
+        assert!(matches!(bob_state, BobState::BtcLocked { .. }));
+
+        let alice_state = alice_swap.await??;
+
+        // Ensure punish timelock is expired
+        if let AliceState::XmrLockTransactionSent { state3, .. } = alice_state {
+            alice_bitcoin_wallet
+                .subscribe_to(state3.tx_lock)
+                .await
+                .wait_until_confirmed_with(state3.punish_timelock)
+                .await?;
+        } else {
+            panic!(
+                "\
+            Alice in unexpected state {}",
+                alice_state
+            );
+        }
+
+        ctx.restart_alice().await;
+        let alice_swap = ctx.alice_next_swap().await;
+        let alice_swap = tokio::spawn(alice::run(alice_swap));
+
+        let alice_state = alice_swap.await??;
+        ctx.assert_alice_punished(alice_state).await;
+
+        // Restart Bob after Alice punished to ensure Bob transitions to
+        // punished and does not run indefinitely
+        let (bob_swap, _) = ctx.stop_and_resume_bob_from_db(bob_join_handle).await;
+        assert!(matches!(bob_swap.state, BobState::BtcLocked { .. }));
+
+        let bob_state = bob::run(bob_swap).await?;
+
+        ctx.assert_bob_punished(bob_state).await;
+
+        Ok(())
+    })
+    .await;
+}

swap/tests/happy_path_restart_alice_after_xmr_locked.rs

@@ -0,0 +1,40 @@
+pub mod harness;
+
+use harness::alice_run_until::is_xmr_lock_transaction_sent;
+use harness::SlowCancelConfig;
+use swap::protocol::alice::AliceState;
+use swap::protocol::{alice, bob};
+
+#[tokio::test]
+async fn given_alice_restarts_after_xmr_is_locked_resume_swap() {
+    harness::setup_test(SlowCancelConfig, |mut ctx| async move {
+        let (bob_swap, _) = ctx.bob_swap().await;
+        let bob_swap = tokio::spawn(bob::run(bob_swap));
+
+        let alice_swap = ctx.alice_next_swap().await;
+        let alice_swap = tokio::spawn(alice::run_until(alice_swap, is_xmr_lock_transaction_sent));
+
+        let alice_state = alice_swap.await??;
+
+        assert!(matches!(
+            alice_state,
+            AliceState::XmrLockTransactionSent { .. }
+        ));
+
+        ctx.restart_alice().await;
+        let alice_swap = ctx.alice_next_swap().await;
+        assert!(matches!(
+            alice_swap.state,
+            AliceState::XmrLockTransactionSent { .. }
+        ));
+
+        let alice_state = alice::run(alice_swap).await?;
+        ctx.assert_alice_redeemed(alice_state).await;
+
+        let bob_state = bob_swap.await??;
+        ctx.assert_bob_redeemed(bob_state).await;
+
+        Ok(())
+    })
+    .await;
+}

swap/tests/harness/mod.rs

@@ -29,8 +29,9 @@ use tempfile::tempdir;
 use testcontainers::clients::Cli;
 use testcontainers::{Container, Docker, RunArgs};
 use tokio::sync::mpsc;
+use tokio::sync::mpsc::Receiver;
 use tokio::task::JoinHandle;
-use tokio::time::interval;
+use tokio::time::{interval, timeout};
 use tracing_subscriber::util::SubscriberInitExt;
 use url::Url;
 use uuid::Uuid;
@@ -79,24 +80,40 @@ impl BobParams {
     }
 }
 
-pub struct BobEventLoopJoinHandle(JoinHandle<()>);
+pub struct BobApplicationHandle(JoinHandle<()>);
 
-impl BobEventLoopJoinHandle {
+impl BobApplicationHandle {
     pub fn abort(&self) {
         self.0.abort()
     }
 }
 
-pub struct AliceEventLoopJoinHandle(JoinHandle<()>);
+pub struct AliceApplicationHandle {
+    handle: JoinHandle<()>,
+    peer_id: PeerId,
+}
+
+impl AliceApplicationHandle {
+    pub fn abort(&self) {
+        self.handle.abort()
+    }
+}
 
 pub struct TestContext {
+    env_config: Config,
+
     btc_amount: bitcoin::Amount,
     xmr_amount: monero::Amount,
 
+    alice_seed: Seed,
+    alice_db_path: PathBuf,
+    alice_listen_address: Multiaddr,
+
     alice_starting_balances: StartingBalances,
     alice_bitcoin_wallet: Arc<bitcoin::Wallet>,
     alice_monero_wallet: Arc<monero::Wallet>,
     alice_swap_handle: mpsc::Receiver<Swap>,
+    alice_handle: AliceApplicationHandle,
 
     bob_params: BobParams,
     bob_starting_balances: StartingBalances,
@@ -105,11 +122,30 @@ pub struct TestContext {
 }
 
 impl TestContext {
-    pub async fn alice_next_swap(&mut self) -> alice::Swap {
-        self.alice_swap_handle.recv().await.unwrap()
+    pub async fn restart_alice(&mut self) {
+        self.alice_handle.abort();
+
+        let (alice_handle, alice_swap_handle) = start_alice(
+            &self.alice_seed,
+            self.alice_db_path.clone(),
+            self.alice_listen_address.clone(),
+            self.env_config,
+            self.alice_bitcoin_wallet.clone(),
+            self.alice_monero_wallet.clone(),
+        );
+
+        self.alice_handle = alice_handle;
+        self.alice_swap_handle = alice_swap_handle;
     }
 
-    pub async fn bob_swap(&mut self) -> (bob::Swap, BobEventLoopJoinHandle) {
+    pub async fn alice_next_swap(&mut self) -> alice::Swap {
+        timeout(Duration::from_secs(10), self.alice_swap_handle.recv())
+            .await
+            .expect("No Alice swap within 10 seconds, aborting because this test is waiting for a swap forever...")
+            .unwrap()
+    }
+
+    pub async fn bob_swap(&mut self) -> (bob::Swap, BobApplicationHandle) {
         let (event_loop, event_loop_handle) = self.bob_params.new_eventloop().unwrap();
 
         let swap = self
@@ -123,13 +159,13 @@ impl TestContext {
 
         let join_handle = tokio::spawn(event_loop.run());
 
-        (swap, BobEventLoopJoinHandle(join_handle))
+        (swap, BobApplicationHandle(join_handle))
     }
 
     pub async fn stop_and_resume_bob_from_db(
         &mut self,
-        join_handle: BobEventLoopJoinHandle,
-    ) -> (bob::Swap, BobEventLoopJoinHandle) {
+        join_handle: BobApplicationHandle,
+    ) -> (bob::Swap, BobApplicationHandle) {
         join_handle.abort();
 
         let (event_loop, event_loop_handle) = self.bob_params.new_eventloop().unwrap();
@@ -144,7 +180,7 @@ impl TestContext {
 
         let join_handle = tokio::spawn(event_loop.run());
 
-        (swap, BobEventLoopJoinHandle(join_handle))
+        (swap, BobApplicationHandle(join_handle))
     }
 
     pub async fn assert_alice_redeemed(&mut self, state: AliceState) {
@@ -462,20 +498,12 @@ where
         btc: bitcoin::Amount::ZERO,
     };
 
-    let port = get_port().expect("Failed to find a free port");
-
-    let alice_listen_address: Multiaddr = format!("/ip4/127.0.0.1/tcp/{}", port)
-        .parse()
-        .expect("failed to parse Alice's address");
-
     let electrs_rpc_port = containers
         .electrs
         .get_host_port(harness::electrs::RPC_PORT)
         .expect("Could not map electrs rpc port");
 
     let alice_seed = Seed::random().unwrap();
-    let bob_seed = Seed::random().unwrap();
-
     let (alice_bitcoin_wallet, alice_monero_wallet) = init_test_wallets(
         MONERO_WALLET_NAME_ALICE,
         containers.bitcoind_url.clone(),
@@ -483,16 +511,27 @@ where
         alice_starting_balances.clone(),
         tempdir().unwrap().path(),
         electrs_rpc_port,
-        alice_seed,
+        &alice_seed,
         env_config,
     )
     .await;
 
-    let db_path = tempdir().unwrap();
-    let alice_db = Arc::new(Database::open(db_path.path()).unwrap());
+    let alice_listen_port = get_port().expect("Failed to find a free port");
+    let alice_listen_address: Multiaddr = format!("/ip4/127.0.0.1/tcp/{}", alice_listen_port)
+        .parse()
+        .expect("failed to parse Alice's address");
 
-    let alice_seed = Seed::random().unwrap();
+    let alice_db_path = tempdir().unwrap().into_path();
+    let (alice_handle, alice_swap_handle) = start_alice(
+        &alice_seed,
+        alice_db_path.clone(),
+        alice_listen_address.clone(),
+        env_config,
+        alice_bitcoin_wallet.clone(),
+        alice_monero_wallet.clone(),
+    );
 
+    let bob_seed = Seed::random().unwrap();
     let bob_starting_balances = StartingBalances {
         xmr: monero::Amount::ZERO,
         btc: btc_amount * 10,
@@ -505,47 +544,34 @@ where
         bob_starting_balances.clone(),
         tempdir().unwrap().path(),
         electrs_rpc_port,
-        bob_seed,
+        &bob_seed,
         env_config,
     )
     .await;
 
-    let mut alice_swarm = swarm::new::<alice::Behaviour>(&alice_seed).unwrap();
-    Swarm::listen_on(&mut alice_swarm, alice_listen_address.clone()).unwrap();
-
-    let (alice_event_loop, alice_swap_handle) = alice::EventLoop::new(
-        alice_swarm,
-        env_config,
-        alice_bitcoin_wallet.clone(),
-        alice_monero_wallet.clone(),
-        alice_db,
-        FixedRate::default(),
-        bitcoin::Amount::ONE_BTC,
-    )
-    .unwrap();
-
-    let alice_peer_id = alice_event_loop.peer_id();
-
-    tokio::spawn(alice_event_loop.run());
-
     let bob_params = BobParams {
         seed: Seed::random().unwrap(),
         db_path: tempdir().unwrap().path().to_path_buf(),
         swap_id: Uuid::new_v4(),
         bitcoin_wallet: bob_bitcoin_wallet.clone(),
         monero_wallet: bob_monero_wallet.clone(),
-        alice_address: alice_listen_address,
-        alice_peer_id,
+        alice_address: alice_listen_address.clone(),
+        alice_peer_id: alice_handle.peer_id,
         env_config,
     };
 
     let test = TestContext {
+        env_config,
         btc_amount,
         xmr_amount,
+        alice_seed,
+        alice_db_path,
+        alice_listen_address,
         alice_starting_balances,
         alice_bitcoin_wallet,
         alice_monero_wallet,
         alice_swap_handle,
+        alice_handle,
         bob_params,
         bob_starting_balances,
         bob_bitcoin_wallet,
@@ -555,6 +581,36 @@ where
     testfn(test).await.unwrap()
 }
 
+fn start_alice(
+    seed: &Seed,
+    db_path: PathBuf,
+    listen_address: Multiaddr,
+    env_config: Config,
+    bitcoin_wallet: Arc<bitcoin::Wallet>,
+    monero_wallet: Arc<monero::Wallet>,
+) -> (AliceApplicationHandle, Receiver<alice::Swap>) {
+    let db = Arc::new(Database::open(db_path.as_path()).unwrap());
+
+    let mut swarm = swarm::new::<alice::Behaviour>(&seed).unwrap();
+    Swarm::listen_on(&mut swarm, listen_address).unwrap();
+
+    let (event_loop, swap_handle) = alice::EventLoop::new(
+        swarm,
+        env_config,
+        bitcoin_wallet,
+        monero_wallet,
+        db,
+        FixedRate::default(),
+        bitcoin::Amount::ONE_BTC,
+    )
+    .unwrap();
+
+    let peer_id = event_loop.peer_id();
+    let handle = tokio::spawn(event_loop.run());
+
+    (AliceApplicationHandle { handle, peer_id }, swap_handle)
+}
+
 fn random_prefix() -> String {
     use rand::distributions::Alphanumeric;
     use rand::{thread_rng, Rng};
@@ -714,7 +770,7 @@ async fn init_test_wallets(
     starting_balances: StartingBalances,
     datadir: &Path,
     electrum_rpc_port: u16,
-    seed: Seed,
+    seed: &Seed,
     env_config: Config,
 ) -> (Arc<bitcoin::Wallet>, Arc<monero::Wallet>) {
     monero
@@ -847,7 +903,7 @@ impl GetConfig for FastPunishConfig {
     fn get_config() -> Config {
         Config {
             bitcoin_cancel_timelock: CancelTimelock::new(10),
-            bitcoin_punish_timelock: PunishTimelock::new(1),
+            bitcoin_punish_timelock: PunishTimelock::new(10),
             ..env::Regtest::get_config()
         }
     }