Merge #94

94: T1Expired state for Bob and check expiries in states after both locked r=da-kami a=da-kami



Co-authored-by: Daniel Karzel <daniel@comit.network>

swap/src/bob/swap.rs

@@ -7,13 +7,10 @@ use crate::{
 };
 use anyhow::{bail, Result};
 use async_recursion::async_recursion;
-use futures::{
-    future::{select, Either},
-    pin_mut,
-};
 use libp2p::{core::Multiaddr, PeerId};
 use rand::{CryptoRng, RngCore};
 use std::{convert::TryFrom, fmt, sync::Arc};
+use tokio::select;
 use tracing::info;
 use uuid::Uuid;
 use xmr_btc::{
@@ -33,6 +30,7 @@ pub enum BobState {
     XmrLocked(bob::State4, PeerId),
     EncSigSent(bob::State4, PeerId),
     BtcRedeemed(bob::State5),
+    T1Expired(bob::State4),
     Cancelled(bob::State4),
     BtcRefunded(bob::State4),
     XmrRedeemed,
@@ -49,6 +47,7 @@ impl fmt::Display for BobState {
             BobState::XmrLocked(..) => write!(f, "xmr_locked"),
             BobState::EncSigSent(..) => write!(f, "encsig_sent"),
             BobState::BtcRedeemed(..) => write!(f, "btc_redeemed"),
+            BobState::T1Expired(..) => write!(f, "t1_expired"),
             BobState::Cancelled(..) => write!(f, "cancelled"),
             BobState::BtcRefunded(..) => write!(f, "btc_refunded"),
             BobState::XmrRedeemed => write!(f, "xmr_redeemed"),
@@ -70,6 +69,7 @@ impl From<BobState> for state::Bob {
             BobState::XmrLocked(state4, peer_id) => Bob::XmrLocked { state4, peer_id },
             BobState::EncSigSent(state4, peer_id) => Bob::EncSigSent { state4, peer_id },
             BobState::BtcRedeemed(state5) => Bob::BtcRedeemed(state5),
+            BobState::T1Expired(state4) => Bob::T1Expired(state4),
             BobState::Cancelled(state4) => Bob::BtcCancelled(state4),
             BobState::BtcRefunded(_)
             | BobState::XmrRedeemed
@@ -90,6 +90,7 @@ impl TryFrom<state::Swap> for BobState {
                 Bob::XmrLocked { state4, peer_id } => BobState::XmrLocked(state4, peer_id),
                 Bob::EncSigSent { state4, peer_id } => BobState::EncSigSent(state4, peer_id),
                 Bob::BtcRedeemed(state5) => BobState::BtcRedeemed(state5),
+                Bob::T1Expired(state4) => BobState::T1Expired(state4),
                 Bob::BtcCancelled(state4) => BobState::Cancelled(state4),
                 Bob::SwapComplete => BobState::SafelyAborted,
             };
@@ -272,18 +273,28 @@ where
                 .await
             }
             BobState::XmrLocked(state, alice_peer_id) => {
-                // Alice has locked Xmr
-                // Bob sends Alice his key
-                let tx_redeem_encsig = state.tx_redeem_encsig();
-                // Do we have to wait for a response?
-                // What if Alice fails to receive this? Should we always resend?
-                // todo: If we cannot dial Alice we should go to EncSigSent. Maybe dialing
-                // should happen in this arm?
-                event_loop_handle
-                    .send_message3(alice_peer_id.clone(), tx_redeem_encsig)
-                    .await?;
+                let state = if let Epoch::T0 = state.current_epoch(bitcoin_wallet.as_ref()).await? {
+                    // Alice has locked Xmr
+                    // Bob sends Alice his key
+                    let tx_redeem_encsig = state.tx_redeem_encsig();
+
+                    let state4_clone = state.clone();
+                    let enc_sig_sent_watcher =
+                        event_loop_handle.send_message3(alice_peer_id.clone(), tx_redeem_encsig);
+                    let bitcoin_wallet = bitcoin_wallet.clone();
+                    let t1_timeout = state4_clone.wait_for_t1(bitcoin_wallet.as_ref());
 
-                let state = BobState::EncSigSent(state, alice_peer_id);
+                    select! {
+                        _ = enc_sig_sent_watcher => {
+                            BobState::EncSigSent(state, alice_peer_id)
+                        },
+                        _ = t1_timeout => {
+                            BobState::T1Expired(state)
+                        }
+                    }
+                } else {
+                    BobState::T1Expired(state)
+                };
                 let db_state = state.clone().into();
                 db.insert_latest_state(swap_id, state::Swap::Bob(db_state))
                     .await?;
@@ -300,28 +311,21 @@ where
                 .await
             }
             BobState::EncSigSent(state, ..) => {
-                let state_clone = state.clone();
-                let redeem_watcher = state_clone.watch_for_redeem_btc(bitcoin_wallet.as_ref());
-                let t1_timeout = state_clone.wait_for_t1(bitcoin_wallet.as_ref());
+                let state = if let Epoch::T0 = state.current_epoch(bitcoin_wallet.as_ref()).await? {
+                    let state_clone = state.clone();
+                    let redeem_watcher = state_clone.watch_for_redeem_btc(bitcoin_wallet.as_ref());
+                    let t1_timeout = state_clone.wait_for_t1(bitcoin_wallet.as_ref());
 
-                pin_mut!(redeem_watcher);
-                pin_mut!(t1_timeout);
-
-                let state = match select(redeem_watcher, t1_timeout).await {
-                    Either::Left((val, _)) => BobState::BtcRedeemed(val?),
-                    Either::Right((..)) => {
-                        // Check whether TxCancel has been published.
-                        // We should not fail if the transaction is already on the blockchain
-                        if state
-                            .check_for_tx_cancel(bitcoin_wallet.as_ref())
-                            .await
-                            .is_err()
-                        {
-                            state.submit_tx_cancel(bitcoin_wallet.as_ref()).await?;
+                    select! {
+                        state5 = redeem_watcher => {
+                            BobState::BtcRedeemed(state5?)
+                        },
+                        _ = t1_timeout => {
+                            BobState::T1Expired(state)
                         }
-
-                        BobState::Cancelled(state)
                     }
+                } else {
+                    BobState::T1Expired(state)
                 };
 
                 let db_state = state.clone().into();
@@ -359,6 +363,31 @@ where
                 )
                 .await
             }
+            BobState::T1Expired(state4) => {
+                if state4
+                    .check_for_tx_cancel(bitcoin_wallet.as_ref())
+                    .await
+                    .is_err()
+                {
+                    state4.submit_tx_cancel(bitcoin_wallet.as_ref()).await?;
+                }
+
+                let state = BobState::Cancelled(state4);
+                db.insert_latest_state(swap_id, state::Swap::Bob(state.clone().into()))
+                    .await?;
+
+                run_until(
+                    state,
+                    is_target_state,
+                    event_loop_handle,
+                    db,
+                    bitcoin_wallet,
+                    monero_wallet,
+                    rng,
+                    swap_id,
+                )
+                .await
+            }
             BobState::Cancelled(state) => {
                 // TODO
                 // Bob has cancelled the swap

swap/src/state.rs

@@ -60,6 +60,7 @@ pub enum Bob {
         peer_id: PeerId,
     },
     BtcRedeemed(bob::State5),
+    T1Expired(bob::State4),
     BtcCancelled(bob::State4),
     SwapComplete,
 }
@@ -92,7 +93,7 @@ impl Display for Alice {
             Alice::BtcLocked(_) => f.write_str("Bitcoin locked"),
             Alice::XmrLocked(_) => f.write_str("Monero locked"),
             Alice::BtcRedeemable { .. } => f.write_str("Bitcoin redeemable"),
-            Alice::T1Expired(_) => f.write_str("Submitting TxCancel"),
+            Alice::T1Expired(_) => f.write_str("Timelock T1 expired"),
             Alice::BtcCancelled(_) => f.write_str("Bitcoin cancel transaction published"),
             Alice::BtcPunishable(_) => f.write_str("Bitcoin punishable"),
             Alice::BtcRefunded { .. } => f.write_str("Monero refundable"),
@@ -106,9 +107,10 @@ impl Display for Bob {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             Bob::Negotiated { .. } => f.write_str("Handshake complete"),
-            Bob::BtcLocked { .. } | Bob::XmrLocked { .. } | Bob::BtcCancelled(_) => {
-                f.write_str("Bitcoin refundable")
-            }
+            Bob::BtcLocked { .. } => f.write_str("Bitcoin locked"),
+            Bob::XmrLocked { .. } => f.write_str("Monero locked"),
+            Bob::T1Expired(_) => f.write_str("Timelock T1 expired"),
+            Bob::BtcCancelled(_) => f.write_str("Bitcoin refundable"),
             Bob::BtcRedeemed(_) => f.write_str("Monero redeemable"),
             Bob::SwapComplete => f.write_str("Swap complete"),
             Bob::EncSigSent { .. } => f.write_str("Encrypted signature sent"),