From 86f312e1435cf6f4cf60529e0f533711e6168d1a Mon Sep 17 00:00:00 2001
From: rishflab <rishflab@hotmail.com>
Date: Thu, 18 Mar 2021 12:40:32 +1100
Subject: [PATCH] Safely abort swap if TxLock is not confirmed in a reasonable
 time

If TxLock does not confirm in a reasonable amount of time, Alice should
give up on the swap rather than waiting forever. Watching for TxLock in
the mempool is not required and it causes unnecessary complexity. What
if Alice does not see the transaction in mempool but it is already
confirmed? She will abort the swap for no reason.
---
 swap/src/env.rs                 |  8 ++++----
 swap/src/protocol/alice/swap.rs | 26 +++++++++++++++++++-------
 2 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/swap/src/env.rs b/swap/src/env.rs
index e020faea..04deb791 100644
--- a/swap/src/env.rs
+++ b/swap/src/env.rs
@@ -5,7 +5,7 @@ use time::NumericalStdDurationShort;
 
 #[derive(Debug, Copy, Clone)]
 pub struct Config {
-    pub bob_time_to_act: Duration,
+    pub bitcoin_lock_confirmed_timeout: Duration,
     pub bitcoin_finality_confirmations: u32,
     pub bitcoin_avg_block_time: Duration,
     pub bitcoin_cancel_timelock: CancelTimelock,
@@ -42,7 +42,7 @@ pub struct Regtest;
 impl GetConfig for Mainnet {
     fn get_config() -> Config {
         Config {
-            bob_time_to_act: 10.minutes(),
+            bitcoin_lock_confirmed_timeout: 24.hours(),
             bitcoin_finality_confirmations: 3,
             bitcoin_avg_block_time: 10.minutes(),
             bitcoin_cancel_timelock: CancelTimelock::new(72),
@@ -58,7 +58,7 @@ impl GetConfig for Mainnet {
 impl GetConfig for Testnet {
     fn get_config() -> Config {
         Config {
-            bob_time_to_act: 60.minutes(),
+            bitcoin_lock_confirmed_timeout: 12.hours(),
             bitcoin_finality_confirmations: 1,
             bitcoin_avg_block_time: 5.minutes(),
             bitcoin_cancel_timelock: CancelTimelock::new(12),
@@ -74,7 +74,7 @@ impl GetConfig for Testnet {
 impl GetConfig for Regtest {
     fn get_config() -> Config {
         Config {
-            bob_time_to_act: 30.seconds(),
+            bitcoin_lock_confirmed_timeout: 1.minutes(),
             bitcoin_finality_confirmations: 1,
             bitcoin_avg_block_time: 5.seconds(),
             bitcoin_cancel_timelock: CancelTimelock::new(100),
diff --git a/swap/src/protocol/alice/swap.rs b/swap/src/protocol/alice/swap.rs
index b07b92ae..6806f668 100644
--- a/swap/src/protocol/alice/swap.rs
+++ b/swap/src/protocol/alice/swap.rs
@@ -69,13 +69,25 @@ async fn next_state(
     Ok(match state {
         AliceState::Started { state3 } => {
             let tx_lock_status = bitcoin_wallet.subscribe_to(state3.tx_lock.clone()).await;
-            timeout(env_config.bob_time_to_act, tx_lock_status.wait_until_seen())
-                .await
-                .context("Failed to find lock Bitcoin tx")??;
-
-            tx_lock_status.wait_until_final().await?;
-
-            AliceState::BtcLocked { state3 }
+            match timeout(
+                env_config.bitcoin_lock_confirmed_timeout,
+                tx_lock_status.wait_until_final(),
+            )
+            .await
+            {
+                Err(_) => {
+                    tracing::info!(
+                        "TxLock lock did not get {} confirmations in {} minutes",
+                        env_config.bitcoin_finality_confirmations,
+                        env_config.bitcoin_lock_confirmed_timeout.as_secs_f64() / 60.0
+                    );
+                    AliceState::SafelyAborted
+                }
+                Ok(res) => {
+                    res?;
+                    AliceState::BtcLocked { state3 }
+                }
+            }
         }
         AliceState::BtcLocked { state3 } => {
             // Record the current monero wallet block height so we don't have to scan from