Expose the current best chain tip from ChannelManager + Monitors

Fixes #979

fuzz/src/chanmon_consistency.rs

@@ -30,13 +30,13 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hash_types::{BlockHash, WPubkeyHash};
 
 use lightning::chain;
-use lightning::chain::{chainmonitor, channelmonitor, Confirm, Watch};
+use lightning::chain::{BestBlock, chainmonitor, channelmonitor, Confirm, Watch};
 use lightning::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, MonitorEvent};
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
 use lightning::chain::keysinterface::{KeysInterface, InMemorySigner};
 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
-use lightning::ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, PaymentSendFailure, ChannelManagerReadArgs};
+use lightning::ln::channelmanager::{ChainParameters, ChannelManager, PaymentSendFailure, ChannelManagerReadArgs};
 use lightning::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
 use lightning::ln::msgs::{CommitmentUpdate, ChannelMessageHandler, DecodeError, UpdateAddHTLC, Init};
 use lightning::util::enforcing_trait_impls::{EnforcingSigner, INITIAL_REVOKED_COMMITMENT_NUMBER};

fuzz/src/full_stack.rs

@@ -27,13 +27,13 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
 
 use lightning::chain;
-use lightning::chain::{Confirm, Listen};
+use lightning::chain::{BestBlock, Confirm, Listen};
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
 use lightning::chain::chainmonitor;
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::keysinterface::{InMemorySigner, KeysInterface};
 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
-use lightning::ln::channelmanager::{BestBlock, ChainParameters, ChannelManager};
+use lightning::ln::channelmanager::{ChainParameters, ChannelManager};
 use lightning::ln::peer_handler::{MessageHandler,PeerManager,SocketDescriptor};
 use lightning::ln::msgs::DecodeError;
 use lightning::routing::router::get_route;

lightning-background-processor/src/lib.rs

@@ -174,13 +174,12 @@ mod tests {
 	use bitcoin::blockdata::constants::genesis_block;
 	use bitcoin::blockdata::transaction::{Transaction, TxOut};
 	use bitcoin::network::constants::Network;
-	use lightning::chain::Confirm;
+	use lightning::chain::{BestBlock, Confirm, chainmonitor};
-	use lightning::chain::chainmonitor;
 	use lightning::chain::channelmonitor::ANTI_REORG_DELAY;
 	use lightning::chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager};
 	use lightning::chain::transaction::OutPoint;
 	use lightning::get_event_msg;
-	use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, BestBlock, ChainParameters, ChannelManager, SimpleArcChannelManager};
+	use lightning::ln::channelmanager::{BREAKDOWN_TIMEOUT, ChainParameters, ChannelManager, SimpleArcChannelManager};
 	use lightning::ln::features::InitFeatures;
 	use lightning::ln::msgs::ChannelMessageHandler;
 	use lightning::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor};

lightning/src/chain/channelmonitor.rs

@@ -37,9 +37,9 @@ use ln::{PaymentHash, PaymentPreimage};
 use ln::msgs::DecodeError;
 use ln::chan_utils;
 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, HTLCType, ChannelTransactionParameters, HolderCommitmentTransaction};
-use ln::channelmanager::{BestBlock, HTLCSource};
+use ln::channelmanager::HTLCSource;
 use chain;
-use chain::WatchedOutput;
+use chain::{BestBlock, WatchedOutput};
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::transaction::{OutPoint, TransactionData};
 use chain::keysinterface::{SpendableOutputDescriptor, StaticPaymentOutputDescriptor, DelayedPaymentOutputDescriptor, Sign, KeysInterface};
@@ -1189,6 +1189,12 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
 		txids.dedup();
 		txids
 	}
+
+	/// Gets the latest best block which was connected either via the [`chain::Listen`] or
+	/// [`chain::Confirm`] interfaces.
+	pub fn current_best_block(&self) -> BestBlock {
+		self.inner.lock().unwrap().best_block.clone()
+	}
 }
 
 impl<Signer: Sign> ChannelMonitorImpl<Signer> {
@@ -2827,11 +2833,11 @@ mod tests {
 	use bitcoin::hash_types::Txid;
 	use bitcoin::network::constants::Network;
 	use hex;
+	use chain::BestBlock;
 	use chain::channelmonitor::ChannelMonitor;
 	use chain::package::{WEIGHT_OFFERED_HTLC, WEIGHT_RECEIVED_HTLC, WEIGHT_REVOKED_OFFERED_HTLC, WEIGHT_REVOKED_RECEIVED_HTLC, WEIGHT_REVOKED_OUTPUT};
 	use chain::transaction::OutPoint;
 	use ln::{PaymentPreimage, PaymentHash};
-	use ln::channelmanager::BestBlock;
 	use ln::chan_utils;
 	use ln::chan_utils::{HTLCOutputInCommitment, ChannelPublicKeys, ChannelTransactionParameters, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
 	use util::test_utils::{TestLogger, TestBroadcaster, TestFeeEstimator};

lightning/src/chain/mod.rs

@@ -10,9 +10,11 @@
 //! Structs and traits which allow other parts of rust-lightning to interact with the blockchain.
 
 use bitcoin::blockdata::block::{Block, BlockHeader};
+use bitcoin::blockdata::constants::genesis_block;
 use bitcoin::blockdata::script::Script;
 use bitcoin::blockdata::transaction::{Transaction, TxOut};
 use bitcoin::hash_types::{BlockHash, Txid};
+use bitcoin::network::constants::Network;
 
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent};
 use chain::keysinterface::Sign;
@@ -28,6 +30,34 @@ pub mod keysinterface;
 pub(crate) mod onchaintx;
 pub(crate) mod package;
 
+/// The best known block as identified by its hash and height.
+#[derive(Clone, Copy, PartialEq)]
+pub struct BestBlock {
+	block_hash: BlockHash,
+	height: u32,
+}
+
+impl BestBlock {
+	/// Returns the best block from the genesis of the given network.
+	pub fn from_genesis(network: Network) -> Self {
+		BestBlock {
+			block_hash: genesis_block(network).header.block_hash(),
+			height: 0,
+		}
+	}
+
+	/// Returns the best block as identified by the given block hash and height.
+	pub fn new(block_hash: BlockHash, height: u32) -> Self {
+		BestBlock { block_hash, height }
+	}
+
+	/// Returns the best block hash.
+	pub fn block_hash(&self) -> BlockHash { self.block_hash }
+
+	/// Returns the best block height.
+	pub fn height(&self) -> u32 { self.height }
+}
+
 /// An error when accessing the chain via [`Access`].
 #[derive(Clone)]
 pub enum AccessError {

lightning/src/ln/channel.rs

@@ -26,9 +26,10 @@ use ln::{PaymentPreimage, PaymentHash};
 use ln::features::{ChannelFeatures, InitFeatures};
 use ln::msgs;
 use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
-use ln::channelmanager::{BestBlock, PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
 use ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor};
 use ln::chan_utils;
+use chain::BestBlock;
 use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, HTLC_FAIL_BACK_BUFFER};
 use chain::transaction::{OutPoint, TransactionData};
@@ -4988,13 +4989,14 @@ mod tests {
 	use bitcoin::hashes::hex::FromHex;
 	use hex;
 	use ln::{PaymentPreimage, PaymentHash};
-	use ln::channelmanager::{BestBlock, HTLCSource};
+	use ln::channelmanager::HTLCSource;
 	use ln::channel::{Channel,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,HTLCCandidate,HTLCInitiator,TxCreationKeys};
 	use ln::channel::MAX_FUNDING_SATOSHIS;
 	use ln::features::InitFeatures;
 	use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate};
 	use ln::chan_utils;
 	use ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT};
+	use chain::BestBlock;
 	use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
 	use chain::keysinterface::{InMemorySigner, KeysInterface, BaseSign};
 	use chain::transaction::OutPoint;

lightning/src/ln/channelmanager.rs

@@ -36,8 +36,7 @@ use bitcoin::secp256k1::ecdh::SharedSecret;
 use bitcoin::secp256k1;
 
 use chain;
-use chain::Confirm;
+use chain::{Confirm, Watch, BestBlock};
-use chain::Watch;
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, ChannelMonitorUpdateErr, HTLC_FAIL_BACK_BUFFER, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY, MonitorEvent, CLOSED_CHANNEL_UPDATE_ID};
 use chain::transaction::{OutPoint, TransactionData};
@@ -508,34 +507,6 @@ pub struct ChainParameters {
 	pub best_block: BestBlock,
 }
 
-/// The best known block as identified by its hash and height.
-#[derive(Clone, Copy, PartialEq)]
-pub struct BestBlock {
-	block_hash: BlockHash,
-	height: u32,
-}
-
-impl BestBlock {
-	/// Returns the best block from the genesis of the given network.
-	pub fn from_genesis(network: Network) -> Self {
-		BestBlock {
-			block_hash: genesis_block(network).header.block_hash(),
-			height: 0,
-		}
-	}
-
-	/// Returns the best block as identified by the given block hash and height.
-	pub fn new(block_hash: BlockHash, height: u32) -> Self {
-		BestBlock { block_hash, height }
-	}
-
-	/// Returns the best block hash.
-	pub fn block_hash(&self) -> BlockHash { self.block_hash }
-
-	/// Returns the best block height.
-	pub fn height(&self) -> u32 { self.height }
-}
-
 #[derive(Copy, Clone, PartialEq)]
 enum NotifyOption {
 	DoPersist,
@@ -4085,6 +4056,12 @@ where
 		let guard = mtx.lock().unwrap();
 		*guard
 	}
+
+	/// Gets the latest best block which was connected either via the [`chain::Listen`] or
+	/// [`chain::Confirm`] interfaces.
+	pub fn current_best_block(&self) -> BestBlock {
+		self.best_block.read().unwrap().clone()
+	}
 }
 
 impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >

lightning/src/ln/functional_test_utils.rs

@@ -10,11 +10,11 @@
 //! A bunch of useful utilities for building networks of nodes and exchanging messages between
 //! nodes for functional tests.
 
-use chain::{Confirm, Listen, Watch};
+use chain::{BestBlock, Confirm, Listen, Watch};
 use chain::channelmonitor::ChannelMonitor;
 use chain::transaction::OutPoint;
 use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
-use ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, ChannelManagerReadArgs, RAACommitmentOrder, PaymentSendFailure};
+use ln::channelmanager::{ChainParameters, ChannelManager, ChannelManagerReadArgs, RAACommitmentOrder, PaymentSendFailure};
 use routing::router::{Route, get_route};
 use routing::network_graph::{NetGraphMsgHandler, NetworkGraph};
 use ln::features::{InitFeatures, InvoiceFeatures};