Construct all ChannelMonitor mutexes in the same function

When we add lockorder detection based on mutex construction site
rather than mutex instance in the next commit, ChannelMonitor's
PartialEq implementation causes spurious failures. This is caused
by the lockorder detection logic considering the ChannelMonitor
inner mutex to be two distinct mutexes - one when monitors are
deserialized and one when monitors are created fresh. Instead, we
attempt to tell the lockorder detection logic that they are the
same by ensuring they're constructed in the same place - in this
case a util method.

diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
index 80cd9cb9d45958629e1789513190a4de63b87e7b..8dd3d4b43b680755581d9bc94ac2c2881035e763 100644 (file)
--- a/lightning/src/chain/channelmonitor.rs
+++ b/lightning/src/chain/channelmonitor.rs
@@ -965,6 +965,13 @@ impl<Signer: Sign> Writeable for ChannelMonitorImpl<Signer> {
 }
 
 impl<Signer: Sign> ChannelMonitor<Signer> {
+       /// For lockorder enforcement purposes, we need to have a single site which constructs the
+       /// `inner` mutex, otherwise cases where we lock two monitors at the same time (eg in our
+       /// PartialEq implementation) we may decide a lockorder violation has occurred.
+       fn from_impl(imp: ChannelMonitorImpl<Signer>) -> Self {
+               ChannelMonitor { inner: Mutex::new(imp) }
+       }
+
        pub(crate) fn new(secp_ctx: Secp256k1<secp256k1::All>, keys: Signer, shutdown_script: Option<Script>,
                          on_counterparty_tx_csv: u16, destination_script: &Script, funding_info: (OutPoint, Script),
                          channel_parameters: &ChannelTransactionParameters,
@@ -1012,60 +1019,58 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
                let mut outputs_to_watch = HashMap::new();
                outputs_to_watch.insert(funding_info.0.txid, vec![(funding_info.0.index as u32, funding_info.1.clone())]);
 
-               ChannelMonitor {
-                       inner: Mutex::new(ChannelMonitorImpl {
-                               latest_update_id: 0,
-                               commitment_transaction_number_obscure_factor,
+               Self::from_impl(ChannelMonitorImpl {
+                       latest_update_id: 0,
+                       commitment_transaction_number_obscure_factor,
 
-                               destination_script: destination_script.clone(),
-                               broadcasted_holder_revokable_script: None,
-                               counterparty_payment_script,
-                               shutdown_script,
+                       destination_script: destination_script.clone(),
+                       broadcasted_holder_revokable_script: None,
+                       counterparty_payment_script,
+                       shutdown_script,
 
-                               channel_keys_id,
-                               holder_revocation_basepoint,
-                               funding_info,
-                               current_counterparty_commitment_txid: None,
-                               prev_counterparty_commitment_txid: None,
+                       channel_keys_id,
+                       holder_revocation_basepoint,
+                       funding_info,
+                       current_counterparty_commitment_txid: None,
+                       prev_counterparty_commitment_txid: None,
 
-                               counterparty_commitment_params,
-                               funding_redeemscript,
-                               channel_value_satoshis,
-                               their_cur_per_commitment_points: None,
+                       counterparty_commitment_params,
+                       funding_redeemscript,
+                       channel_value_satoshis,
+                       their_cur_per_commitment_points: None,
 
-                               on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
+                       on_holder_tx_csv: counterparty_channel_parameters.selected_contest_delay,
 
-                               commitment_secrets: CounterpartyCommitmentSecrets::new(),
-                               counterparty_claimable_outpoints: HashMap::new(),
-                               counterparty_commitment_txn_on_chain: HashMap::new(),
-                               counterparty_hash_commitment_number: HashMap::new(),
+                       commitment_secrets: CounterpartyCommitmentSecrets::new(),
+                       counterparty_claimable_outpoints: HashMap::new(),
+                       counterparty_commitment_txn_on_chain: HashMap::new(),
+                       counterparty_hash_commitment_number: HashMap::new(),
 
-                               prev_holder_signed_commitment_tx: None,
-                               current_holder_commitment_tx: holder_commitment_tx,
-                               current_counterparty_commitment_number: 1 << 48,
-                               current_holder_commitment_number,
+                       prev_holder_signed_commitment_tx: None,
+                       current_holder_commitment_tx: holder_commitment_tx,
+                       current_counterparty_commitment_number: 1 << 48,
+                       current_holder_commitment_number,
 
-                               payment_preimages: HashMap::new(),
-                               pending_monitor_events: Vec::new(),
-                               pending_events: Vec::new(),
+                       payment_preimages: HashMap::new(),
+                       pending_monitor_events: Vec::new(),
+                       pending_events: Vec::new(),
 
-                               onchain_events_awaiting_threshold_conf: Vec::new(),
-                               outputs_to_watch,
+                       onchain_events_awaiting_threshold_conf: Vec::new(),
+                       outputs_to_watch,
 
-                               onchain_tx_handler,
+                       onchain_tx_handler,
 
-                               lockdown_from_offchain: false,
-                               holder_tx_signed: false,
-                               funding_spend_seen: false,
-                               funding_spend_confirmed: None,
-                               htlcs_resolved_on_chain: Vec::new(),
+                       lockdown_from_offchain: false,
+                       holder_tx_signed: false,
+                       funding_spend_seen: false,
+                       funding_spend_confirmed: None,
+                       htlcs_resolved_on_chain: Vec::new(),
 
-                               best_block,
-                               counterparty_node_id: Some(counterparty_node_id),
+                       best_block,
+                       counterparty_node_id: Some(counterparty_node_id),
 
-                               secp_ctx,
-                       }),
-               }
+                       secp_ctx,
+               })
        }
 
        #[cfg(test)]
@@ -3361,60 +3366,58 @@ impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
 
-               Ok((best_block.block_hash(), ChannelMonitor {
-                       inner: Mutex::new(ChannelMonitorImpl {
-                               latest_update_id,
-                               commitment_transaction_number_obscure_factor,
+               Ok((best_block.block_hash(), ChannelMonitor::from_impl(ChannelMonitorImpl {
+                       latest_update_id,
+                       commitment_transaction_number_obscure_factor,
 
-                               destination_script,
-                               broadcasted_holder_revokable_script,
-                               counterparty_payment_script,
-                               shutdown_script,
+                       destination_script,
+                       broadcasted_holder_revokable_script,
+                       counterparty_payment_script,
+                       shutdown_script,
 
-                               channel_keys_id,
-                               holder_revocation_basepoint,
-                               funding_info,
-                               current_counterparty_commitment_txid,
-                               prev_counterparty_commitment_txid,
+                       channel_keys_id,
+                       holder_revocation_basepoint,
+                       funding_info,
+                       current_counterparty_commitment_txid,
+                       prev_counterparty_commitment_txid,
 
-                               counterparty_commitment_params,
-                               funding_redeemscript,
-                               channel_value_satoshis,
-                               their_cur_per_commitment_points,
+                       counterparty_commitment_params,
+                       funding_redeemscript,
+                       channel_value_satoshis,
+                       their_cur_per_commitment_points,
 
-                               on_holder_tx_csv,
+                       on_holder_tx_csv,
 
-                               commitment_secrets,
-                               counterparty_claimable_outpoints,
-                               counterparty_commitment_txn_on_chain,
-                               counterparty_hash_commitment_number,
+                       commitment_secrets,
+                       counterparty_claimable_outpoints,
+                       counterparty_commitment_txn_on_chain,
+                       counterparty_hash_commitment_number,
 
-                               prev_holder_signed_commitment_tx,
-                               current_holder_commitment_tx,
-                               current_counterparty_commitment_number,
-                               current_holder_commitment_number,
+                       prev_holder_signed_commitment_tx,
+                       current_holder_commitment_tx,
+                       current_counterparty_commitment_number,
+                       current_holder_commitment_number,
 
-                               payment_preimages,
-                               pending_monitor_events: pending_monitor_events.unwrap(),
-                               pending_events,
+                       payment_preimages,
+                       pending_monitor_events: pending_monitor_events.unwrap(),
+                       pending_events,
 
-                               onchain_events_awaiting_threshold_conf,
-                               outputs_to_watch,
+                       onchain_events_awaiting_threshold_conf,
+                       outputs_to_watch,
 
-                               onchain_tx_handler,
+                       onchain_tx_handler,
 
-                               lockdown_from_offchain,
-                               holder_tx_signed,
-                               funding_spend_seen: funding_spend_seen.unwrap(),
-                               funding_spend_confirmed,
-                               htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
+                       lockdown_from_offchain,
+                       holder_tx_signed,
+                       funding_spend_seen: funding_spend_seen.unwrap(),
+                       funding_spend_confirmed,
+                       htlcs_resolved_on_chain: htlcs_resolved_on_chain.unwrap(),
 
-                               best_block,
-                               counterparty_node_id,
+                       best_block,
+                       counterparty_node_id,
 
-                               secp_ctx,
-                       }),
-               }))
+                       secp_ctx,
+               })))
        }
 }