From b49e63b1bc759d49a203a1cd503cace86736e704 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Sat, 21 Mar 2020 18:29:17 -0400
Subject: [PATCH] Flatten ChannelMonitor substructs that don't add clarity

The new OnchainDetection struct (which is the remnants of the old
KeyStorage enum, which was removed in 1dbda4faedc33506e63176e6a456)
doesn't really add any clarity to ChannelMonitor, so best to just
drop it and move its members into ChannelMonitor directly.
---
 lightning/src/ln/channelmonitor.rs | 136 +++++++++++++----------------
 1 file changed, 61 insertions(+), 75 deletions(-)

diff --git a/lightning/src/ln/channelmonitor.rs b/lightning/src/ln/channelmonitor.rs
index 950b50f3..e88dd333 100644
--- a/lightning/src/ln/channelmonitor.rs
+++ b/lightning/src/ln/channelmonitor.rs
@@ -290,7 +290,7 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: De
 			hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
 			hash_map::Entry::Vacant(e) => e,
 		};
-		match monitor.onchain_detection.funding_info {
+		match monitor.funding_info {
 			None => {
 				return Err(MonitorUpdateError("Try to update a useless monitor without funding_txo !"));
 			},
@@ -314,7 +314,7 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: De
 		let mut monitors = self.monitors.lock().unwrap();
 		match monitors.get_mut(&key) {
 			Some(orig_monitor) => {
-				log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor.onchain_detection));
+				log_trace!(self, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
 				orig_monitor.update_monitor(update, &self.broadcaster)
 			},
 			None => Err(MonitorUpdateError("No such monitor registered"))
@@ -391,20 +391,6 @@ pub(crate) const LATENCY_GRACE_PERIOD_BLOCKS: u32 = 3;
 /// keeping bumping another claim tx to solve the outpoint.
 pub(crate) const ANTI_REORG_DELAY: u32 = 6;
 
-struct OnchainDetection<ChanSigner: ChannelKeys> {
-	keys: ChanSigner,
-	funding_info: Option<(OutPoint, Script)>,
-	current_remote_commitment_txid: Option<Sha256dHash>,
-	prev_remote_commitment_txid: Option<Sha256dHash>,
-}
-
-#[cfg(any(test, feature = "fuzztarget"))]
-impl<ChanSigner: ChannelKeys> PartialEq for OnchainDetection<ChanSigner> {
-	fn eq(&self, other: &Self) -> bool {
-		self.keys.pubkeys() == other.keys.pubkeys()
-	}
-}
-
 #[derive(Clone, PartialEq)]
 struct LocalSignedTx {
 	/// txid of the transaction in tx, just used to make comparison faster
@@ -734,7 +720,11 @@ pub struct ChannelMonitor<ChanSigner: ChannelKeys> {
 	broadcasted_remote_payment_script: Option<(Script, SecretKey)>,
 	shutdown_script: Script,
 
-	onchain_detection: OnchainDetection<ChanSigner>,
+	keys: ChanSigner,
+	funding_info: Option<(OutPoint, Script)>,
+	current_remote_commitment_txid: Option<Sha256dHash>,
+	prev_remote_commitment_txid: Option<Sha256dHash>,
+
 	their_htlc_base_key: Option<PublicKey>,
 	their_delayed_payment_base_key: Option<PublicKey>,
 	funding_redeemscript: Option<Script>,
@@ -817,7 +807,10 @@ impl<ChanSigner: ChannelKeys> PartialEq for ChannelMonitor<ChanSigner> {
 			self.destination_script != other.destination_script ||
 			self.broadcasted_local_revokable_script != other.broadcasted_local_revokable_script ||
 			self.broadcasted_remote_payment_script != other.broadcasted_remote_payment_script ||
-			self.onchain_detection != other.onchain_detection ||
+			self.keys.pubkeys() != other.keys.pubkeys() ||
+			self.funding_info != other.funding_info ||
+			self.current_remote_commitment_txid != other.current_remote_commitment_txid ||
+			self.prev_remote_commitment_txid != other.prev_remote_commitment_txid ||
 			self.their_htlc_base_key != other.their_htlc_base_key ||
 			self.their_delayed_payment_base_key != other.their_delayed_payment_base_key ||
 			self.funding_redeemscript != other.funding_redeemscript ||
@@ -878,8 +871,8 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
 		}
 		self.shutdown_script.write(writer)?;
 
-		self.onchain_detection.keys.write(writer)?;
-		match self.onchain_detection.funding_info  {
+		self.keys.write(writer)?;
+		match self.funding_info  {
 			Some((ref outpoint, ref script)) => {
 				writer.write_all(&outpoint.txid[..])?;
 				writer.write_all(&byte_utils::be16_to_array(outpoint.index))?;
@@ -889,8 +882,8 @@ impl<ChanSigner: ChannelKeys + Writeable> ChannelMonitor<ChanSigner> {
 				debug_assert!(false, "Try to serialize a useless Local monitor !");
 			},
 		}
-		self.onchain_detection.current_remote_commitment_txid.write(writer)?;
-		self.onchain_detection.prev_remote_commitment_txid.write(writer)?;
+		self.current_remote_commitment_txid.write(writer)?;
+		self.prev_remote_commitment_txid.write(writer)?;
 
 		writer.write_all(&self.their_htlc_base_key.as_ref().unwrap().serialize())?;
 		writer.write_all(&self.their_delayed_payment_base_key.as_ref().unwrap().serialize())?;
@@ -1096,13 +1089,6 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 		let our_channel_close_key_hash = Hash160::hash(&shutdown_pubkey.serialize());
 		let shutdown_script = Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_script();
 
-		let onchain_detection = OnchainDetection {
-			keys: keys.clone(),
-			funding_info: Some(funding_info),
-			current_remote_commitment_txid: None,
-			prev_remote_commitment_txid: None,
-		};
-
 		ChannelMonitor {
 			latest_update_id: 0,
 			commitment_transaction_number_obscure_factor,
@@ -1112,7 +1098,11 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 			broadcasted_remote_payment_script: None,
 			shutdown_script,
 
-			onchain_detection: onchain_detection,
+			keys: keys.clone(),
+			funding_info: Some(funding_info),
+			current_remote_commitment_txid: None,
+			prev_remote_commitment_txid: None,
+
 			their_htlc_base_key: Some(their_htlc_base_key.clone()),
 			their_delayed_payment_base_key: Some(their_delayed_payment_base_key.clone()),
 			funding_redeemscript: Some(funding_redeemscript.clone()),
@@ -1159,7 +1149,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 
 		// Prune HTLCs from the previous remote commitment tx so we don't generate failure/fulfill
 		// events for now-revoked/fulfilled HTLCs.
-		if let Some(txid) = self.onchain_detection.prev_remote_commitment_txid.take() {
+		if let Some(txid) = self.prev_remote_commitment_txid.take() {
 			for &mut (_, ref mut source) in self.remote_claimable_outpoints.get_mut(&txid).unwrap() {
 				*source = None;
 			}
@@ -1216,8 +1206,8 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 		let new_txid = unsigned_commitment_tx.txid();
 		log_trace!(self, "Tracking new remote commitment transaction with txid {} at commitment number {} with {} HTLC outputs", new_txid, commitment_number, htlc_outputs.len());
 		log_trace!(self, "New potential remote commitment transaction: {}", encode::serialize_hex(unsigned_commitment_tx));
-		self.onchain_detection.prev_remote_commitment_txid = self.onchain_detection.current_remote_commitment_txid.take();
-		self.onchain_detection.current_remote_commitment_txid = Some(new_txid);
+		self.prev_remote_commitment_txid = self.current_remote_commitment_txid.take();
+		self.current_remote_commitment_txid = Some(new_txid);
 		self.remote_claimable_outpoints.insert(new_txid, htlc_outputs);
 		self.current_remote_commitment_number = commitment_number;
 		//TODO: Merge this into the other per-remote-transaction output storage stuff
@@ -1242,11 +1232,11 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 	}
 
 	pub(super) fn provide_rescue_remote_commitment_tx_info(&mut self, their_revocation_point: PublicKey) {
-		if let Ok(payment_key) = chan_utils::derive_public_key(&self.secp_ctx, &their_revocation_point, &self.onchain_detection.keys.pubkeys().payment_basepoint) {
+		if let Ok(payment_key) = chan_utils::derive_public_key(&self.secp_ctx, &their_revocation_point, &self.keys.pubkeys().payment_basepoint) {
 			let to_remote_script =  Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
 				.push_slice(&Hash160::hash(&payment_key.serialize())[..])
 				.into_script();
-			if let Ok(to_remote_key) = chan_utils::derive_private_key(&self.secp_ctx, &their_revocation_point, &self.onchain_detection.keys.payment_base_key()) {
+			if let Ok(to_remote_key) = chan_utils::derive_private_key(&self.secp_ctx, &their_revocation_point, &self.keys.payment_base_key()) {
 				self.broadcasted_remote_payment_script = Some((to_remote_script, to_remote_key));
 			}
 		}
@@ -1377,7 +1367,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 
 	/// Gets the funding transaction outpoint of the channel this ChannelMonitor is monitoring for.
 	pub fn get_funding_txo(&self) -> Option<OutPoint> {
-		if let Some((outp, _)) = self.onchain_detection.funding_info {
+		if let Some((outp, _)) = self.funding_info {
 			return Some(outp)
 		}
 		None
@@ -1469,10 +1459,10 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 			let secret = self.get_secret(commitment_number).unwrap();
 			let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
 			let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
-			let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
-			let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.onchain_detection.keys.revocation_base_key()));
-			let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().htlc_basepoint));
-			let local_payment_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.payment_base_key()));
+			let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
+			let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.keys.revocation_base_key()));
+			let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().htlc_basepoint));
+			let local_payment_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, &per_commitment_point, &self.keys.payment_base_key()));
 			let delayed_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key), &self.their_delayed_payment_base_key.unwrap()));
 			let a_htlc_key = match self.their_htlc_base_key {
 				None => return (claimable_outpoints, (commitment_txid, watch_outputs)),
@@ -1548,10 +1538,10 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 						}
 					}
 				}
-				if let Some(ref txid) = self.onchain_detection.current_remote_commitment_txid {
+				if let Some(ref txid) = self.current_remote_commitment_txid {
 					check_htlc_fails!(txid, "current");
 				}
-				if let Some(ref txid) = self.onchain_detection.prev_remote_commitment_txid {
+				if let Some(ref txid) = self.prev_remote_commitment_txid {
 					check_htlc_fails!(txid, "remote");
 				}
 				// No need to check local commitment txn, symmetric HTLCSource must be present as per-htlc data on remote commitment tx
@@ -1611,10 +1601,10 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 					}
 				}
 			}
-			if let Some(ref txid) = self.onchain_detection.current_remote_commitment_txid {
+			if let Some(ref txid) = self.current_remote_commitment_txid {
 				check_htlc_fails!(txid, "current", 'current_loop);
 			}
-			if let Some(ref txid) = self.onchain_detection.prev_remote_commitment_txid {
+			if let Some(ref txid) = self.prev_remote_commitment_txid {
 				check_htlc_fails!(txid, "previous", 'prev_loop);
 			}
 
@@ -1625,14 +1615,14 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 						if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
 					} else { None };
 				if let Some(revocation_point) = revocation_point_option {
-					let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
-					let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.pubkeys().htlc_basepoint));
-					let htlc_privkey = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.htlc_base_key()));
+					let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, revocation_point, &self.keys.pubkeys().revocation_basepoint));
+					let b_htlc_key = ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &self.keys.pubkeys().htlc_basepoint));
+					let htlc_privkey = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.keys.htlc_base_key()));
 					let a_htlc_key = match self.their_htlc_base_key {
 						None => return (claimable_outpoints, (commitment_txid, watch_outputs)),
 						Some(their_htlc_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, revocation_point, &their_htlc_base_key)),
 					};
-					let local_payment_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.onchain_detection.keys.payment_base_key()));
+					let local_payment_key = ignore_error!(chan_utils::derive_private_key(&self.secp_ctx, revocation_point, &self.keys.payment_base_key()));
 
 					self.broadcasted_remote_payment_script = {
 						// Note that the Network here is ignored as we immediately drop the address for the
@@ -1683,8 +1673,8 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 		let secret = if let Some(secret) = self.get_secret(commitment_number) { secret } else { return (Vec::new(), None); };
 		let per_commitment_key = ignore_error!(SecretKey::from_slice(&secret));
 		let per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &per_commitment_key);
-		let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.onchain_detection.keys.pubkeys().revocation_basepoint));
-		let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.onchain_detection.keys.revocation_base_key()));
+		let revocation_pubkey = ignore_error!(chan_utils::derive_public_revocation_key(&self.secp_ctx, &per_commitment_point, &self.keys.pubkeys().revocation_basepoint));
+		let revocation_key = ignore_error!(chan_utils::derive_private_revocation_key(&self.secp_ctx, &per_commitment_key, &self.keys.revocation_base_key()));
 		let delayed_key = match self.their_delayed_payment_base_key {
 			None => return (Vec::new(), None),
 			Some(their_delayed_payment_base_key) => ignore_error!(chan_utils::derive_public_key(&self.secp_ctx, &per_commitment_point, &their_delayed_payment_base_key)),
@@ -1702,7 +1692,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 		let mut watch_outputs = Vec::with_capacity(local_tx.htlc_outputs.len());
 
 		let redeemscript = chan_utils::get_revokeable_redeemscript(&local_tx.revocation_key, self.their_to_self_delay.unwrap(), &local_tx.delayed_payment_key);
-		let broadcasted_local_revokable_script = if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, &local_tx.per_commitment_point, self.onchain_detection.keys.delayed_payment_base_key()) {
+		let broadcasted_local_revokable_script = if let Ok(local_delayedkey) = chan_utils::derive_private_key(&self.secp_ctx, &local_tx.per_commitment_point, self.keys.delayed_payment_base_key()) {
 			Some((redeemscript.to_v0_p2wsh(), local_delayedkey, redeemscript))
 		} else { None };
 
@@ -1883,7 +1873,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 				// which is an easy way to filter out any potential non-matching txn for lazy
 				// filters.
 				let prevout = &tx.input[0].previous_output;
-				let funding_txo = self.onchain_detection.funding_info.clone();
+				let funding_txo = self.funding_info.clone();
 				if funding_txo.is_none() || (prevout.txid == funding_txo.as_ref().unwrap().0.txid && prevout.vout == funding_txo.as_ref().unwrap().0.index as u32) {
 					if (tx.input[0].sequence >> 8*3) as u8 == 0x80 && (tx.lock_time >> 8*3) as u8 == 0x20 {
 						let (mut new_outpoints, new_outputs) = self.check_spend_remote_transaction(&tx, height);
@@ -1920,7 +1910,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 			self.would_broadcast_at_height(height)
 		} else { false };
 		if should_broadcast {
-			claimable_outpoints.push(ClaimRequest { absolute_timelock: height, aggregable: false, outpoint: BitcoinOutPoint { txid: self.onchain_detection.funding_info.as_ref().unwrap().0.txid.clone(), vout: self.onchain_detection.funding_info.as_ref().unwrap().0.index as u32 }, witness_data: InputMaterial::Funding { channel_value: self.channel_value_satoshis.unwrap() }});
+			claimable_outpoints.push(ClaimRequest { absolute_timelock: height, aggregable: false, outpoint: BitcoinOutPoint { txid: self.funding_info.as_ref().unwrap().0.txid.clone(), vout: self.funding_info.as_ref().unwrap().0.index as u32 }, witness_data: InputMaterial::Funding { channel_value: self.channel_value_satoshis.unwrap() }});
 		}
 		if let Some(ref cur_local_tx) = self.current_local_signed_commitment_tx {
 			if should_broadcast {
@@ -2030,12 +2020,12 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 			scan_commitment!(cur_local_tx.htlc_outputs.iter().map(|&(ref a, _, _)| a), true);
 		}
 
-		if let Some(ref txid) = self.onchain_detection.current_remote_commitment_txid {
+		if let Some(ref txid) = self.current_remote_commitment_txid {
 			if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
 				scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
 			}
 		}
-		if let Some(ref txid) = self.onchain_detection.prev_remote_commitment_txid {
+		if let Some(ref txid) = self.prev_remote_commitment_txid {
 			if let Some(ref htlc_outputs) = self.remote_claimable_outpoints.get(txid) {
 				scan_commitment!(htlc_outputs.iter().map(|&(ref a, _)| a), false);
 			}
@@ -2105,9 +2095,9 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 								// resolve the source HTLC with the original sender.
 								payment_data = Some(((*source).clone(), htlc_output.payment_hash));
 							} else if !$local_tx {
-									check_htlc_valid_remote!(self.onchain_detection.current_remote_commitment_txid, htlc_output);
+									check_htlc_valid_remote!(self.current_remote_commitment_txid, htlc_output);
 								if payment_data.is_none() {
-									check_htlc_valid_remote!(self.onchain_detection.prev_remote_commitment_txid, htlc_output);
+									check_htlc_valid_remote!(self.prev_remote_commitment_txid, htlc_output);
 								}
 							}
 							if payment_data.is_none() {
@@ -2278,24 +2268,16 @@ impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for (Sha256dH
 		};
 		let shutdown_script = Readable::read(reader)?;
 
-		let onchain_detection = {
-			let keys = Readable::read(reader)?;
-			// Technically this can fail and serialize fail a round-trip, but only for serialization of
-			// barely-init'd ChannelMonitors that we can't do anything with.
-			let outpoint = OutPoint {
-				txid: Readable::read(reader)?,
-				index: Readable::read(reader)?,
-			};
-			let funding_info = Some((outpoint, Readable::read(reader)?));
-			let current_remote_commitment_txid = Readable::read(reader)?;
-			let prev_remote_commitment_txid = Readable::read(reader)?;
-			OnchainDetection {
-				keys,
-				funding_info,
-				current_remote_commitment_txid,
-				prev_remote_commitment_txid,
-			}
+		let keys = Readable::read(reader)?;
+		// Technically this can fail and serialize fail a round-trip, but only for serialization of
+		// barely-init'd ChannelMonitors that we can't do anything with.
+		let outpoint = OutPoint {
+			txid: Readable::read(reader)?,
+			index: Readable::read(reader)?,
 		};
+		let funding_info = Some((outpoint, Readable::read(reader)?));
+		let current_remote_commitment_txid = Readable::read(reader)?;
+		let prev_remote_commitment_txid = Readable::read(reader)?;
 
 		let their_htlc_base_key = Some(Readable::read(reader)?);
 		let their_delayed_payment_base_key = Some(Readable::read(reader)?);
@@ -2508,7 +2490,11 @@ impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for (Sha256dH
 			broadcasted_remote_payment_script,
 			shutdown_script,
 
-			onchain_detection,
+			keys,
+			funding_info,
+			current_remote_commitment_txid,
+			prev_remote_commitment_txid,
+
 			their_htlc_base_key,
 			their_delayed_payment_base_key,
 			funding_redeemscript,
-- 
2.30.2