Fail PendingInboundPayments after their expiry time is reached
[rust-lightning] / lightning / src / ln / channelmanager.rs
index dd3fac1b6dc3f248e7edcbba74c6ce1657d7d7e2..ea3c2be917f140308b0d29c92414ccb3fe553f04 100644 (file)
@@ -19,6 +19,7 @@
 //!
 
 use bitcoin::blockdata::block::{Block, BlockHeader};
+use bitcoin::blockdata::transaction::Transaction;
 use bitcoin::blockdata::constants::genesis_block;
 use bitcoin::network::constants::Network;
 
@@ -27,7 +28,7 @@ use bitcoin::hashes::hmac::{Hmac, HmacEngine};
 use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
 use bitcoin::hashes::cmp::fixed_time_eq;
-use bitcoin::hash_types::BlockHash;
+use bitcoin::hash_types::{BlockHash, Txid};
 
 use bitcoin::secp256k1::key::{SecretKey,PublicKey};
 use bitcoin::secp256k1::Secp256k1;
@@ -35,6 +36,7 @@ use bitcoin::secp256k1::ecdh::SharedSecret;
 use bitcoin::secp256k1;
 
 use chain;
+use chain::Confirm;
 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};
@@ -94,7 +96,7 @@ enum PendingHTLCRouting {
                short_channel_id: u64, // This should be NonZero<u64> eventually when we bump MSRV
        },
        Receive {
-               payment_data: Option<msgs::FinalOnionHopData>,
+               payment_data: msgs::FinalOnionHopData,
                incoming_cltv_expiry: u32, // Used to track when we should expire pending HTLCs that go unclaimed
        },
 }
@@ -154,11 +156,10 @@ pub(crate) struct HTLCPreviousHopData {
 struct ClaimableHTLC {
        prev_hop: HTLCPreviousHopData,
        value: u64,
-       /// Filled in when the HTLC was received with a payment_secret packet, which contains a
-       /// total_msat (which may differ from value if this is a Multi-Path Payment) and a
+       /// Contains a total_msat (which may differ from value if this is a Multi-Path Payment) and a
        /// payment_secret which prevents path-probing attacks and can associate different HTLCs which
        /// are part of the same payment.
-       payment_data: Option<msgs::FinalOnionHopData>,
+       payment_data: msgs::FinalOnionHopData,
        cltv_expiry: u32,
 }
 
@@ -325,19 +326,18 @@ pub(super) struct ChannelHolder<Signer: Sign> {
        /// guarantees are made about the existence of a channel with the short id here, nor the short
        /// ids in the PendingHTLCInfo!
        pub(super) forward_htlcs: HashMap<u64, Vec<HTLCForwardInfo>>,
-       /// (payment_hash, payment_secret) -> Vec<HTLCs> for tracking HTLCs that
-       /// were to us and can be failed/claimed by the user
+       /// Map from payment hash to any HTLCs which are to us and can be failed/claimed by the user.
        /// Note that while this is held in the same mutex as the channels themselves, no consistency
        /// guarantees are made about the channels given here actually existing anymore by the time you
        /// go to read them!
-       claimable_htlcs: HashMap<(PaymentHash, Option<PaymentSecret>), Vec<ClaimableHTLC>>,
+       claimable_htlcs: HashMap<PaymentHash, Vec<ClaimableHTLC>>,
        /// Messages to send to peers - pushed to in the same lock that they are generated in (except
        /// for broadcast messages, where ordering isn't as strict).
        pub(super) pending_msg_events: Vec<MessageSendEvent>,
 }
 
 /// Events which we process internally but cannot be procsesed immediately at the generation site
-/// for some reason. They are handled in timer_chan_freshness_every_min, so may be processed with
+/// for some reason. They are handled in timer_tick_occurred, so may be processed with
 /// quite some time lag.
 enum BackgroundEvent {
        /// Handle a ChannelMonitorUpdate that closes a channel, broadcasting its current latest holder
@@ -351,8 +351,23 @@ struct PeerState {
        latest_features: InitFeatures,
 }
 
-#[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
-const ERR: () = "You need at least 32 bit pointers (well, usize, but we'll assume they're the same) for ChannelManager::latest_block_height";
+/// Stores a PaymentSecret and any other data we may need to validate an inbound payment is
+/// actually ours and not some duplicate HTLC sent to us by a node along the route.
+///
+/// For users who don't want to bother doing their own payment preimage storage, we also store that
+/// here.
+struct PendingInboundPayment {
+       /// The payment secret that the sender must use for us to accept this payment
+       payment_secret: PaymentSecret,
+       /// Time at which this HTLC expires - blocks with a header time above this value will result in
+       /// this payment being removed.
+       expiry_time: u64,
+       /// Arbitrary identifier the user specifies (or not)
+       user_payment_id: u64,
+       // Other required attributes of the payment, optionally enforced:
+       payment_preimage: Option<PaymentPreimage>,
+       min_value_msat: Option<u64>,
+}
 
 /// SimpleArcChannelManager is useful when you need a ChannelManager with a static lifetime, e.g.
 /// when you're using lightning-net-tokio (since tokio::spawn requires parameters with static
@@ -402,7 +417,7 @@ pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L> = ChannelManage
 /// ChannelUpdate messages informing peers that the channel is temporarily disabled. To avoid
 /// spam due to quick disconnection/reconnection, updates are not sent until the channel has been
 /// offline for a full minute. In order to track this, you must call
-/// timer_chan_freshness_every_min roughly once per minute, though it doesn't have to be perfect.
+/// timer_tick_occurred roughly once per minute, though it doesn't have to be perfect.
 ///
 /// Rather than using a plain ChannelManager, it is preferable to use either a SimpleArcChannelManager
 /// a SimpleRefChannelManager, for conciseness. See their documentation for more details, but
@@ -423,22 +438,35 @@ pub struct ChannelManager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref,
        tx_broadcaster: T,
 
        #[cfg(test)]
-       pub(super) latest_block_height: AtomicUsize,
+       pub(super) best_block: RwLock<BestBlock>,
        #[cfg(not(test))]
-       latest_block_height: AtomicUsize,
-       last_block_hash: RwLock<BlockHash>,
+       best_block: RwLock<BestBlock>,
        secp_ctx: Secp256k1<secp256k1::All>,
 
        #[cfg(any(test, feature = "_test_utils"))]
        pub(super) channel_state: Mutex<ChannelHolder<Signer>>,
        #[cfg(not(any(test, feature = "_test_utils")))]
        channel_state: Mutex<ChannelHolder<Signer>>,
+
+       /// Storage for PaymentSecrets and any requirements on future inbound payments before we will
+       /// expose them to users via a PaymentReceived event. HTLCs which do not meet the requirements
+       /// here are failed when we process them as pending-forwardable-HTLCs, and entries are removed
+       /// after we generate a PaymentReceived upon receipt of all MPP parts or when they time out.
+       /// Locked *after* channel_state.
+       pending_inbound_payments: Mutex<HashMap<PaymentHash, PendingInboundPayment>>,
+
        our_network_key: SecretKey,
+       our_network_pubkey: PublicKey,
 
        /// Used to track the last value sent in a node_announcement "timestamp" field. We ensure this
        /// value increases strictly since we don't assume access to a time source.
        last_node_announcement_serial: AtomicUsize,
 
+       /// The highest block timestamp we've seen, which is usually a good guess at the current time.
+       /// Assuming most miners are generating blocks with reasonable timestamps, this shouldn't be
+       /// very far in the past, and can only ever be up to two hours in the future.
+       highest_seen_timestamp: AtomicUsize,
+
        /// The bulk of our storage will eventually be here (channels and message queues and the like).
        /// If we are connected to a peer we always at least have an entry here, even if no channels
        /// are currently open with that peer.
@@ -473,13 +501,38 @@ pub struct ChainParameters {
        /// The network for determining the `chain_hash` in Lightning messages.
        pub network: Network,
 
-       /// The hash of the latest block successfully connected.
-       pub latest_hash: BlockHash,
-
-       /// The height of the latest block successfully connected.
+       /// The hash and height of the latest block successfully connected.
        ///
        /// Used to track on-chain channel funding outputs and send payments with reliable timelocks.
-       pub latest_height: usize,
+       pub best_block: BestBlock,
+}
+
+/// The best known block as identified by its hash and height.
+#[derive(Clone, Copy)]
+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 }
 }
 
 /// Whenever we release the `ChannelManager`'s `total_consistency_lock`, from read mode, it is
@@ -523,11 +576,16 @@ pub const BREAKDOWN_TIMEOUT: u16 = 6 * 24;
 pub(crate) const MAX_LOCAL_BREAKDOWN_TIMEOUT: u16 = 2 * 6 * 24 * 7;
 
 /// The minimum number of blocks between an inbound HTLC's CLTV and the corresponding outbound
-/// HTLC's CLTV. This should always be a few blocks greater than channelmonitor::CLTV_CLAIM_BUFFER,
-/// ie the node we forwarded the payment on to should always have enough room to reliably time out
-/// the HTLC via a full update_fail_htlc/commitment_signed dance before we hit the
-/// CLTV_CLAIM_BUFFER point (we static assert that it's at least 3 blocks more).
-const CLTV_EXPIRY_DELTA: u16 = 6 * 12; //TODO?
+/// HTLC's CLTV. The current default represents roughly six hours of blocks at six blocks/hour.
+///
+/// This can be increased (but not decreased) through [`ChannelConfig::cltv_expiry_delta`]
+///
+/// [`ChannelConfig::cltv_expiry_delta`]: crate::util::config::ChannelConfig::cltv_expiry_delta
+// This should always be a few blocks greater than channelmonitor::CLTV_CLAIM_BUFFER,
+// i.e. the node we forwarded the payment on to should always have enough room to reliably time out
+// the HTLC via a full update_fail_htlc/commitment_signed dance before we hit the
+// CLTV_CLAIM_BUFFER point (we static assert that it's at least 3 blocks more).
+pub const MIN_CLTV_EXPIRY_DELTA: u16 = 6 * 6;
 pub(super) const CLTV_FAR_FAR_AWAY: u32 = 6 * 24 * 7; //TODO?
 
 // Check that our CLTV_EXPIRY is at least CLTV_CLAIM_BUFFER + ANTI_REORG_DELAY + LATENCY_GRACE_PERIOD_BLOCKS,
@@ -538,13 +596,13 @@ pub(super) const CLTV_FAR_FAR_AWAY: u32 = 6 * 24 * 7; //TODO?
 // LATENCY_GRACE_PERIOD_BLOCKS.
 #[deny(const_err)]
 #[allow(dead_code)]
-const CHECK_CLTV_EXPIRY_SANITY: u32 = CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;
+const CHECK_CLTV_EXPIRY_SANITY: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;
 
 // Check for ability of an attacker to make us fail on-chain by delaying inbound claim. See
 // ChannelMontior::would_broadcast_at_height for a description of why this is needed.
 #[deny(const_err)]
 #[allow(dead_code)]
-const CHECK_CLTV_EXPIRY_SANITY_2: u32 = CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - 2*CLTV_CLAIM_BUFFER;
+const CHECK_CLTV_EXPIRY_SANITY_2: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - 2*CLTV_CLAIM_BUFFER;
 
 /// Details of a channel, as returned by ChannelManager::list_channels and ChannelManager::list_usable_channels
 #[derive(Clone)]
@@ -815,9 +873,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        chain_monitor,
                        tx_broadcaster,
 
-                       latest_block_height: AtomicUsize::new(params.latest_height),
-                       last_block_hash: RwLock::new(params.latest_hash),
-                       secp_ctx,
+                       best_block: RwLock::new(params.best_block),
 
                        channel_state: Mutex::new(ChannelHolder{
                                by_id: HashMap::new(),
@@ -826,9 +882,14 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                claimable_htlcs: HashMap::new(),
                                pending_msg_events: Vec::new(),
                        }),
+                       pending_inbound_payments: Mutex::new(HashMap::new()),
+
                        our_network_key: keys_manager.get_node_secret(),
+                       our_network_pubkey: PublicKey::from_secret_key(&secp_ctx, &keys_manager.get_node_secret()),
+                       secp_ctx,
 
                        last_node_announcement_serial: AtomicUsize::new(0),
+                       highest_seen_timestamp: AtomicUsize::new(0),
 
                        per_peer_state: RwLock::new(HashMap::new()),
 
@@ -843,12 +904,18 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                }
        }
 
+       /// Gets the current configuration applied to all new channels,  as
+       pub fn get_current_default_configuration(&self) -> &UserConfig {
+               &self.default_configuration
+       }
+
        /// Creates a new outbound channel to the given remote node and with the given value.
        ///
-       /// user_id will be provided back as user_channel_id in FundingGenerationReady and
-       /// FundingBroadcastSafe events to allow tracking of which events correspond with which
-       /// create_channel call. Note that user_channel_id defaults to 0 for inbound channels, so you
-       /// may wish to avoid using 0 for user_id here.
+       /// user_id will be provided back as user_channel_id in FundingGenerationReady events to allow
+       /// tracking of which events correspond with which create_channel call. Note that the
+       /// user_channel_id defaults to 0 for inbound channels, so you may wish to avoid using 0 for
+       /// user_id here. user_id has no meaning inside of LDK, it is simply copied to events and
+       /// otherwise ignored.
        ///
        /// If successful, will generate a SendOpenChannel message event, so you should probably poll
        /// PeerManager::process_events afterwards.
@@ -997,16 +1064,14 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                }
        }
 
-       fn force_close_channel_with_peer(&self, channel_id: &[u8; 32], peer_node_id: Option<&PublicKey>) -> Result<(), APIError> {
+       fn force_close_channel_with_peer(&self, channel_id: &[u8; 32], peer_node_id: Option<&PublicKey>) -> Result<PublicKey, APIError> {
                let mut chan = {
                        let mut channel_state_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_state_lock;
                        if let hash_map::Entry::Occupied(chan) = channel_state.by_id.entry(channel_id.clone()) {
                                if let Some(node_id) = peer_node_id {
                                        if chan.get().get_counterparty_node_id() != *node_id {
-                                               // Error or Ok here doesn't matter - the result is only exposed publicly
-                                               // when peer_node_id is None anyway.
-                                               return Ok(());
+                                               return Err(APIError::ChannelUnavailable{err: "No such channel".to_owned()});
                                        }
                                }
                                if let Some(short_id) = chan.get().get_short_channel_id() {
@@ -1026,14 +1091,27 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        });
                }
 
-               Ok(())
+               Ok(chan.get_counterparty_node_id())
        }
 
        /// Force closes a channel, immediately broadcasting the latest local commitment transaction to
        /// the chain and rejecting new HTLCs on the given channel. Fails if channel_id is unknown to the manager.
        pub fn force_close_channel(&self, channel_id: &[u8; 32]) -> Result<(), APIError> {
                let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
-               self.force_close_channel_with_peer(channel_id, None)
+               match self.force_close_channel_with_peer(channel_id, None) {
+                       Ok(counterparty_node_id) => {
+                               self.channel_state.lock().unwrap().pending_msg_events.push(
+                                       events::MessageSendEvent::HandleError {
+                                               node_id: counterparty_node_id,
+                                               action: msgs::ErrorAction::SendErrorMessage {
+                                                       msg: msgs::ErrorMessage { channel_id: *channel_id, data: "Channel force-closed".to_owned() }
+                                               },
+                                       }
+                               );
+                               Ok(())
+                       },
+                       Err(e) => Err(e)
+               }
        }
 
        /// Force close all channels, immediately broadcasting the latest local commitment transaction
@@ -1151,7 +1229,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                // HTLC_FAIL_BACK_BUFFER blocks to go.
                                // Also, ensure that, in the case of an unknown payment hash, our payment logic has enough time to fail the HTLC backward
                                // before our onchain logic triggers a channel closure (see HTLC_FAIL_BACK_BUFFER rational).
-                               if (msg.cltv_expiry as u64) <= self.latest_block_height.load(Ordering::Acquire) as u64 + HTLC_FAIL_BACK_BUFFER as u64 + 1 {
+                               if (msg.cltv_expiry as u64) <= self.best_block.read().unwrap().height() as u64 + HTLC_FAIL_BACK_BUFFER as u64 + 1 {
                                        return_err!("The final CLTV expiry is too soon to handle", 17, &[0;0]);
                                }
                                // final_incorrect_htlc_amount
@@ -1169,6 +1247,10 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        msgs::OnionHopDataFormat::FinalNode { payment_data } => payment_data,
                                };
 
+                               if payment_data.is_none() {
+                                       return_err!("We require payment_secrets", 0x4000|0x2000|3, &[0;0]);
+                               }
+
                                // Note that we could obviously respond immediately with an update_fulfill_htlc
                                // message, however that would leak that we are the recipient of this payment, so
                                // instead we stay symmetric with the forwarding case, only responding (after a
@@ -1176,7 +1258,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 
                                PendingHTLCStatus::Forward(PendingHTLCInfo {
                                        routing: PendingHTLCRouting::Receive {
-                                               payment_data,
+                                               payment_data: payment_data.unwrap(),
                                                incoming_cltv_expiry: msg.cltv_expiry,
                                        },
                                        payment_hash: msg.payment_hash.clone(),
@@ -1271,10 +1353,10 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        if fee.is_none() || msg.amount_msat < fee.unwrap() || (msg.amount_msat - fee.unwrap()) < *amt_to_forward { // fee_insufficient
                                                break Some(("Prior hop has deviated from specified fees parameters or origin node has obsolete ones", 0x1000 | 12, Some(self.get_channel_update(chan).unwrap())));
                                        }
-                                       if (msg.cltv_expiry as u64) < (*outgoing_cltv_value) as u64 + CLTV_EXPIRY_DELTA as u64 { // incorrect_cltv_expiry
+                                       if (msg.cltv_expiry as u64) < (*outgoing_cltv_value) as u64 + chan.get_cltv_expiry_delta() as u64 { // incorrect_cltv_expiry
                                                break Some(("Forwarding node has tampered with the intended HTLC values or origin node has an obsolete cltv_expiry_delta", 0x1000 | 13, Some(self.get_channel_update(chan).unwrap())));
                                        }
-                                       let cur_height = self.latest_block_height.load(Ordering::Acquire) as u32 + 1;
+                                       let cur_height = self.best_block.read().unwrap().height() + 1;
                                        // Theoretically, channel counterparty shouldn't send us a HTLC expiring now, but we want to be robust wrt to counterparty
                                        // packet sanitization (see HTLC_FAIL_BACK_BUFFER rational)
                                        if msg.cltv_expiry <= cur_height + HTLC_FAIL_BACK_BUFFER as u32 { // expiry_too_soon
@@ -1329,7 +1411,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        short_channel_id,
                        timestamp: chan.get_update_time_counter(),
                        flags: (!were_node_one) as u8 | ((!chan.is_live() as u8) << 1),
-                       cltv_expiry_delta: CLTV_EXPIRY_DELTA,
+                       cltv_expiry_delta: chan.get_cltv_expiry_delta(),
                        htlc_minimum_msat: chan.get_counterparty_htlc_minimum_msat(),
                        htlc_maximum_msat: OptionalField::Present(chan.get_announced_htlc_max_msat()),
                        fee_base_msat: chan.get_holder_fee_base_msat(&self.fee_estimator),
@@ -1491,7 +1573,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        return Err(PaymentSendFailure::PathParameterError(path_errs));
                }
 
-               let cur_height = self.latest_block_height.load(Ordering::Acquire) as u32 + 1;
+               let cur_height = self.best_block.read().unwrap().height() + 1;
                let mut results = Vec::new();
                for path in route.paths.iter() {
                        results.push(self.send_payment_along_path(&path, &payment_hash, payment_secret, total_value, cur_height));
@@ -1518,34 +1600,30 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                }
        }
 
-       /// Call this upon creation of a funding transaction for the given channel.
-       ///
-       /// Note that ALL inputs in the transaction pointed to by funding_txo MUST spend SegWit outputs
-       /// or your counterparty can steal your funds!
-       ///
-       /// Panics if a funding transaction has already been provided for this channel.
-       ///
-       /// May panic if the funding_txo is duplicative with some other channel (note that this should
-       /// be trivially prevented by using unique funding transaction keys per-channel).
-       pub fn funding_transaction_generated(&self, temporary_channel_id: &[u8; 32], funding_txo: OutPoint) {
-               let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
-
+       /// Handles the generation of a funding transaction, optionally (for tests) with a function
+       /// which checks the correctness of the funding transaction given the associated channel.
+       fn funding_transaction_generated_intern<FundingOutput: Fn(&Channel<Signer>, &Transaction) -> Result<OutPoint, APIError>>
+                       (&self, temporary_channel_id: &[u8; 32], funding_transaction: Transaction, find_funding_output: FundingOutput) -> Result<(), APIError> {
                let (chan, msg) = {
                        let (res, chan) = match self.channel_state.lock().unwrap().by_id.remove(temporary_channel_id) {
                                Some(mut chan) => {
-                                       (chan.get_outbound_funding_created(funding_txo, &self.logger)
+                                       let funding_txo = find_funding_output(&chan, &funding_transaction)?;
+
+                                       (chan.get_outbound_funding_created(funding_transaction, funding_txo, &self.logger)
                                                .map_err(|e| if let ChannelError::Close(msg) = e {
                                                        MsgHandleErrInternal::from_finish_shutdown(msg, chan.channel_id(), chan.force_shutdown(true), None)
                                                } else { unreachable!(); })
                                        , chan)
                                },
-                               None => return
+                               None => { return Err(APIError::ChannelUnavailable { err: "No such channel".to_owned() }) },
                        };
                        match handle_error!(self, res, chan.get_counterparty_node_id()) {
                                Ok(funding_msg) => {
                                        (chan, funding_msg)
                                },
-                               Err(_) => { return; }
+                               Err(_) => { return Err(APIError::ChannelUnavailable {
+                                       err: "Error deriving keys or signing initial commitment transactions - either our RNG or our counterparty's RNG is broken or the Signer refused to sign".to_owned()
+                               }) },
                        }
                };
 
@@ -1562,6 +1640,69 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                e.insert(chan);
                        }
                }
+               Ok(())
+       }
+
+       #[cfg(test)]
+       pub(crate) fn funding_transaction_generated_unchecked(&self, temporary_channel_id: &[u8; 32], funding_transaction: Transaction, output_index: u16) -> Result<(), APIError> {
+               self.funding_transaction_generated_intern(temporary_channel_id, funding_transaction, |_, tx| {
+                       Ok(OutPoint { txid: tx.txid(), index: output_index })
+               })
+       }
+
+       /// Call this upon creation of a funding transaction for the given channel.
+       ///
+       /// Returns an [`APIError::APIMisuseError`] if the funding_transaction spent non-SegWit outputs
+       /// or if no output was found which matches the parameters in [`Event::FundingGenerationReady`].
+       ///
+       /// Panics if a funding transaction has already been provided for this channel.
+       ///
+       /// May panic if the output found in the funding transaction is duplicative with some other
+       /// channel (note that this should be trivially prevented by using unique funding transaction
+       /// keys per-channel).
+       ///
+       /// Do NOT broadcast the funding transaction yourself. When we have safely received our
+       /// counterparty's signature the funding transaction will automatically be broadcast via the
+       /// [`BroadcasterInterface`] provided when this `ChannelManager` was constructed.
+       ///
+       /// Note that this includes RBF or similar transaction replacement strategies - lightning does
+       /// not currently support replacing a funding transaction on an existing channel. Instead,
+       /// create a new channel with a conflicting funding transaction.
+       pub fn funding_transaction_generated(&self, temporary_channel_id: &[u8; 32], funding_transaction: Transaction) -> Result<(), APIError> {
+               let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
+
+               for inp in funding_transaction.input.iter() {
+                       if inp.witness.is_empty() {
+                               return Err(APIError::APIMisuseError {
+                                       err: "Funding transaction must be fully signed and spend Segwit outputs".to_owned()
+                               });
+                       }
+               }
+               self.funding_transaction_generated_intern(temporary_channel_id, funding_transaction, |chan, tx| {
+                       let mut output_index = None;
+                       let expected_spk = chan.get_funding_redeemscript().to_v0_p2wsh();
+                       for (idx, outp) in tx.output.iter().enumerate() {
+                               if outp.script_pubkey == expected_spk && outp.value == chan.get_value_satoshis() {
+                                       if output_index.is_some() {
+                                               return Err(APIError::APIMisuseError {
+                                                       err: "Multiple outputs matched the expected script and value".to_owned()
+                                               });
+                                       }
+                                       if idx > u16::max_value() as usize {
+                                               return Err(APIError::APIMisuseError {
+                                                       err: "Transaction had more than 2^16 outputs, which is not supported".to_owned()
+                                               });
+                                       }
+                                       output_index = Some(idx as u16);
+                               }
+                       }
+                       if output_index.is_none() {
+                               return Err(APIError::APIMisuseError {
+                                       err: "No output matched the script_pubkey and value in the FundingGenerationReady event".to_owned()
+                               });
+                       }
+                       Ok(OutPoint { txid: tx.txid(), index: output_index.unwrap() })
+               })
        }
 
        fn get_announcement_sigs(&self, chan: &Channel<Signer>) -> Option<msgs::AnnouncementSignatures> {
@@ -1811,64 +1952,95 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                        routing: PendingHTLCRouting::Receive { payment_data, incoming_cltv_expiry },
                                                                        incoming_shared_secret, payment_hash, amt_to_forward, .. },
                                                                        prev_funding_outpoint } => {
-                                                               let prev_hop = HTLCPreviousHopData {
-                                                                       short_channel_id: prev_short_channel_id,
-                                                                       outpoint: prev_funding_outpoint,
-                                                                       htlc_id: prev_htlc_id,
-                                                                       incoming_packet_shared_secret: incoming_shared_secret,
-                                                               };
-
-                                                               let mut total_value = 0;
-                                                               let payment_secret_opt =
-                                                                       if let &Some(ref data) = &payment_data { Some(data.payment_secret.clone()) } else { None };
-                                                               let htlcs = channel_state.claimable_htlcs.entry((payment_hash, payment_secret_opt))
-                                                                       .or_insert(Vec::new());
-                                                               htlcs.push(ClaimableHTLC {
-                                                                       prev_hop,
+                                                               let claimable_htlc = ClaimableHTLC {
+                                                                       prev_hop: HTLCPreviousHopData {
+                                                                               short_channel_id: prev_short_channel_id,
+                                                                               outpoint: prev_funding_outpoint,
+                                                                               htlc_id: prev_htlc_id,
+                                                                               incoming_packet_shared_secret: incoming_shared_secret,
+                                                                       },
                                                                        value: amt_to_forward,
                                                                        payment_data: payment_data.clone(),
                                                                        cltv_expiry: incoming_cltv_expiry,
-                                                               });
-                                                               if let &Some(ref data) = &payment_data {
-                                                                       for htlc in htlcs.iter() {
-                                                                               total_value += htlc.value;
-                                                                               if htlc.payment_data.as_ref().unwrap().total_msat != data.total_msat {
-                                                                                       total_value = msgs::MAX_VALUE_MSAT;
-                                                                               }
-                                                                               if total_value >= msgs::MAX_VALUE_MSAT { break; }
-                                                                       }
-                                                                       if total_value >= msgs::MAX_VALUE_MSAT || total_value > data.total_msat  {
-                                                                               for htlc in htlcs.iter() {
-                                                                                       let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
-                                                                                       htlc_msat_height_data.extend_from_slice(
-                                                                                               &byte_utils::be32_to_array(
-                                                                                                       self.latest_block_height.load(Ordering::Acquire)
-                                                                                                               as u32,
-                                                                                               ),
-                                                                                       );
-                                                                                       failed_forwards.push((HTLCSource::PreviousHopData(HTLCPreviousHopData {
-                                                                                                       short_channel_id: htlc.prev_hop.short_channel_id,
-                                                                                                       outpoint: prev_funding_outpoint,
-                                                                                                       htlc_id: htlc.prev_hop.htlc_id,
-                                                                                                       incoming_packet_shared_secret: htlc.prev_hop.incoming_packet_shared_secret,
-                                                                                               }), payment_hash,
-                                                                                               HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: htlc_msat_height_data }
-                                                                                       ));
-                                                                               }
-                                                                       } else if total_value == data.total_msat {
-                                                                               new_events.push(events::Event::PaymentReceived {
-                                                                                       payment_hash,
-                                                                                       payment_secret: Some(data.payment_secret),
-                                                                                       amt: total_value,
-                                                                               });
+                                                               };
+
+                                                               macro_rules! fail_htlc {
+                                                                       ($htlc: expr) => {
+                                                                               let mut htlc_msat_height_data = byte_utils::be64_to_array($htlc.value).to_vec();
+                                                                               htlc_msat_height_data.extend_from_slice(
+                                                                                       &byte_utils::be32_to_array(self.best_block.read().unwrap().height()),
+                                                                               );
+                                                                               failed_forwards.push((HTLCSource::PreviousHopData(HTLCPreviousHopData {
+                                                                                               short_channel_id: $htlc.prev_hop.short_channel_id,
+                                                                                               outpoint: prev_funding_outpoint,
+                                                                                               htlc_id: $htlc.prev_hop.htlc_id,
+                                                                                               incoming_packet_shared_secret: $htlc.prev_hop.incoming_packet_shared_secret,
+                                                                                       }), payment_hash,
+                                                                                       HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: htlc_msat_height_data }
+                                                                               ));
                                                                        }
-                                                               } else {
-                                                                       new_events.push(events::Event::PaymentReceived {
-                                                                               payment_hash,
-                                                                               payment_secret: None,
-                                                                               amt: amt_to_forward,
-                                                                       });
                                                                }
+
+                                                               // Check that the payment hash and secret are known. Note that we
+                                                               // MUST take care to handle the "unknown payment hash" and
+                                                               // "incorrect payment secret" cases here identically or we'd expose
+                                                               // that we are the ultimate recipient of the given payment hash.
+                                                               // Further, we must not expose whether we have any other HTLCs
+                                                               // associated with the same payment_hash pending or not.
+                                                               let mut payment_secrets = self.pending_inbound_payments.lock().unwrap();
+                                                               match payment_secrets.entry(payment_hash) {
+                                                                       hash_map::Entry::Vacant(_) => {
+                                                                               log_trace!(self.logger, "Failing new HTLC with payment_hash {} as we didn't have a corresponding inbound payment.", log_bytes!(payment_hash.0));
+                                                                               fail_htlc!(claimable_htlc);
+                                                                       },
+                                                                       hash_map::Entry::Occupied(inbound_payment) => {
+                                                                               if inbound_payment.get().payment_secret != payment_data.payment_secret {
+                                                                                       log_trace!(self.logger, "Failing new HTLC with payment_hash {} as it didn't match our expected payment secret.", log_bytes!(payment_hash.0));
+                                                                                       fail_htlc!(claimable_htlc);
+                                                                               } else if inbound_payment.get().min_value_msat.is_some() && payment_data.total_msat < inbound_payment.get().min_value_msat.unwrap() {
+                                                                                       log_trace!(self.logger, "Failing new HTLC with payment_hash {} as it didn't match our minimum value (had {}, needed {}).",
+                                                                                               log_bytes!(payment_hash.0), payment_data.total_msat, inbound_payment.get().min_value_msat.unwrap());
+                                                                                       fail_htlc!(claimable_htlc);
+                                                                               } else {
+                                                                                       let mut total_value = 0;
+                                                                                       let htlcs = channel_state.claimable_htlcs.entry(payment_hash)
+                                                                                               .or_insert(Vec::new());
+                                                                                       htlcs.push(claimable_htlc);
+                                                                                       for htlc in htlcs.iter() {
+                                                                                               total_value += htlc.value;
+                                                                                               if htlc.payment_data.total_msat != payment_data.total_msat {
+                                                                                                       log_trace!(self.logger, "Failing HTLCs with payment_hash {} as the HTLCs had inconsistent total values (eg {} and {})",
+                                                                                                               log_bytes!(payment_hash.0), payment_data.total_msat, htlc.payment_data.total_msat);
+                                                                                                       total_value = msgs::MAX_VALUE_MSAT;
+                                                                                               }
+                                                                                               if total_value >= msgs::MAX_VALUE_MSAT { break; }
+                                                                                       }
+                                                                                       if total_value >= msgs::MAX_VALUE_MSAT || total_value > payment_data.total_msat {
+                                                                                               log_trace!(self.logger, "Failing HTLCs with payment_hash {} as the total value {} ran over expected value {} (or HTLCs were inconsistent)",
+                                                                                                       log_bytes!(payment_hash.0), total_value, payment_data.total_msat);
+                                                                                               for htlc in htlcs.iter() {
+                                                                                                       fail_htlc!(htlc);
+                                                                                               }
+                                                                                       } else if total_value == payment_data.total_msat {
+                                                                                               new_events.push(events::Event::PaymentReceived {
+                                                                                                       payment_hash,
+                                                                                                       payment_preimage: inbound_payment.get().payment_preimage,
+                                                                                                       payment_secret: payment_data.payment_secret,
+                                                                                                       amt: total_value,
+                                                                                                       user_payment_id: inbound_payment.get().user_payment_id,
+                                                                                               });
+                                                                                               // Only ever generate at most one PaymentReceived
+                                                                                               // per registered payment_hash, even if it isn't
+                                                                                               // claimed.
+                                                                                               inbound_payment.remove_entry();
+                                                                                       } else {
+                                                                                               // Nothing to do - we haven't reached the total
+                                                                                               // payment value yet, wait until we receive more
+                                                                                               // MPP parts.
+                                                                                       }
+                                                                               }
+                                                                       },
+                                                               };
                                                        },
                                                        HTLCForwardInfo::AddHTLC { .. } => {
                                                                panic!("short_channel_id == 0 should imply any pending_forward entries are of type Receive");
@@ -1895,10 +2067,10 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                events.append(&mut new_events);
        }
 
-       /// Free the background events, generally called from timer_chan_freshness_every_min.
+       /// Free the background events, generally called from timer_tick_occurred.
        ///
        /// Exposed for testing to allow us to process events quickly without generating accidental
-       /// BroadcastChannelUpdate events in timer_chan_freshness_every_min.
+       /// BroadcastChannelUpdate events in timer_tick_occurred.
        ///
        /// Expects the caller to have a total_consistency_lock read lock.
        fn process_background_events(&self) {
@@ -1927,7 +2099,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        /// This method handles all the details, and must be called roughly once per minute.
        ///
        /// Note that in some rare cases this may generate a `chain::Watch::update_channel` call.
-       pub fn timer_chan_freshness_every_min(&self) {
+       pub fn timer_tick_occurred(&self) {
                let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
                self.process_background_events();
 
@@ -1954,18 +2126,17 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        /// along the path (including in our own channel on which we received it).
        /// Returns false if no payment was found to fail backwards, true if the process of failing the
        /// HTLC backwards has been started.
-       pub fn fail_htlc_backwards(&self, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>) -> bool {
+       pub fn fail_htlc_backwards(&self, payment_hash: &PaymentHash) -> bool {
                let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
 
                let mut channel_state = Some(self.channel_state.lock().unwrap());
-               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&(*payment_hash, *payment_secret));
+               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(payment_hash);
                if let Some(mut sources) = removed_source {
                        for htlc in sources.drain(..) {
                                if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
                                let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
                                htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(
-                                       self.latest_block_height.load(Ordering::Acquire) as u32,
-                               ));
+                                               self.best_block.read().unwrap().height()));
                                self.fail_htlc_backwards_internal(channel_state.take().unwrap(),
                                                HTLCSource::PreviousHopData(htlc.prev_hop), payment_hash,
                                                HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: htlc_msat_height_data });
@@ -2124,24 +2295,22 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        /// generating message events for the net layer to claim the payment, if possible. Thus, you
        /// should probably kick the net layer to go send messages if this returns true!
        ///
-       /// You must specify the expected amounts for this HTLC, and we will only claim HTLCs
-       /// available within a few percent of the expected amount. This is critical for several
-       /// reasons : a) it avoids providing senders with `proof-of-payment` (in the form of the
-       /// payment_preimage without having provided the full value and b) it avoids certain
-       /// privacy-breaking recipient-probing attacks which may reveal payment activity to
-       /// motivated attackers.
-       ///
-       /// Note that the privacy concerns in (b) are not relevant in payments with a payment_secret
-       /// set. Thus, for such payments we will claim any payments which do not under-pay.
+       /// Note that if you did not set an `amount_msat` when calling [`create_inbound_payment`] or
+       /// [`create_inbound_payment_for_hash`] you must check that the amount in the `PaymentReceived`
+       /// event matches your expectation. If you fail to do so and call this method, you may provide
+       /// the sender "proof-of-payment" when they did not fulfill the full expected payment.
        ///
        /// May panic if called except in response to a PaymentReceived event.
-       pub fn claim_funds(&self, payment_preimage: PaymentPreimage, payment_secret: &Option<PaymentSecret>, expected_amount: u64) -> bool {
+       ///
+       /// [`create_inbound_payment`]: Self::create_inbound_payment
+       /// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
+       pub fn claim_funds(&self, payment_preimage: PaymentPreimage) -> bool {
                let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 
                let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
 
                let mut channel_state = Some(self.channel_state.lock().unwrap());
-               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&(payment_hash, *payment_secret));
+               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&payment_hash);
                if let Some(mut sources) = removed_source {
                        assert!(!sources.is_empty());
 
@@ -2156,31 +2325,22 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        // we got all the HTLCs and then a channel closed while we were waiting for the user to
                        // provide the preimage, so worrying too much about the optimal handling isn't worth
                        // it.
-
-                       let (is_mpp, mut valid_mpp) = if let &Some(ref data) = &sources[0].payment_data {
-                               assert!(payment_secret.is_some());
-                               (true, data.total_msat >= expected_amount)
-                       } else {
-                               assert!(payment_secret.is_none());
-                               (false, false)
-                       };
-
+                       let mut valid_mpp = true;
                        for htlc in sources.iter() {
-                               if !is_mpp || !valid_mpp { break; }
                                if let None = channel_state.as_ref().unwrap().short_to_id.get(&htlc.prev_hop.short_channel_id) {
                                        valid_mpp = false;
+                                       break;
                                }
                        }
 
                        let mut errs = Vec::new();
                        let mut claimed_any_htlcs = false;
                        for htlc in sources.drain(..) {
-                               if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
-                               if (is_mpp && !valid_mpp) || (!is_mpp && (htlc.value < expected_amount || htlc.value > expected_amount * 2)) {
+                               if !valid_mpp {
+                                       if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
                                        let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
                                        htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(
-                                               self.latest_block_height.load(Ordering::Acquire) as u32,
-                                       ));
+                                                       self.best_block.read().unwrap().height()));
                                        self.fail_htlc_backwards_internal(channel_state.take().unwrap(),
                                                                         HTLCSource::PreviousHopData(htlc.prev_hop), &payment_hash,
                                                                         HTLCFailReason::Reason { failure_code: 0x4000|15, data: htlc_msat_height_data });
@@ -2194,10 +2354,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                claimed_any_htlcs = true;
                                                        } else { errs.push(e); }
                                                },
-                                               Err(None) if is_mpp => unreachable!("We already checked for channel existence, we can't fail here!"),
-                                               Err(None) => {
-                                                       log_warn!(self.logger, "Channel we expected to claim an HTLC from was closed.");
-                                               },
+                                               Err(None) => unreachable!("We already checked for channel existence, we can't fail here!"),
                                                Ok(()) => claimed_any_htlcs = true,
                                        }
                                }
@@ -2310,7 +2467,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 
        /// Gets the node_id held by this ChannelManager
        pub fn get_our_node_id(&self) -> PublicKey {
-               PublicKey::from_secret_key(&self.secp_ctx, &self.our_network_key)
+               self.our_network_pubkey.clone()
        }
 
        /// Restores a single, given channel to normal operation after a
@@ -2354,7 +2511,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                return;
                        }
 
-                       let (raa, commitment_update, order, pending_forwards, mut pending_failures, needs_broadcast_safe, funding_locked) = channel.monitor_updating_restored(&self.logger);
+                       let (raa, commitment_update, order, pending_forwards, mut pending_failures, funding_broadcastable, funding_locked) = channel.monitor_updating_restored(&self.logger);
                        if !pending_forwards.is_empty() {
                                htlc_forwards.push((channel.get_short_channel_id().expect("We can't have pending forwards before funding confirmation"), funding_txo.clone(), pending_forwards));
                        }
@@ -2386,11 +2543,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        handle_cs!();
                                },
                        }
-                       if needs_broadcast_safe {
-                               pending_events.push(events::Event::FundingBroadcastSafe {
-                                       funding_txo: channel.get_funding_txo().unwrap(),
-                                       user_channel_id: channel.get_user_id(),
-                               });
+                       if let Some(tx) = funding_broadcastable {
+                               self.tx_broadcaster.broadcast_transaction(&tx);
                        }
                        if let Some(msg) = funding_locked {
                                pending_msg_events.push(events::MessageSendEvent::SendFundingLocked {
@@ -2468,7 +2622,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 
        fn internal_funding_created(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingCreated) -> Result<(), MsgHandleErrInternal> {
                let ((funding_msg, monitor), mut chan) = {
-                       let last_block_hash = *self.last_block_hash.read().unwrap();
+                       let best_block = *self.best_block.read().unwrap();
                        let mut channel_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_lock;
                        match channel_state.by_id.entry(msg.temporary_channel_id.clone()) {
@@ -2476,7 +2630,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        if chan.get().get_counterparty_node_id() != *counterparty_node_id {
                                                return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.temporary_channel_id));
                                        }
-                                       (try_chan_entry!(self, chan.get_mut().funding_created(msg, last_block_hash, &self.logger), channel_state, chan), chan.remove())
+                                       (try_chan_entry!(self, chan.get_mut().funding_created(msg, best_block, &self.logger), channel_state, chan), chan.remove())
                                },
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.temporary_channel_id))
                        }
@@ -2524,8 +2678,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        }
 
        fn internal_funding_signed(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingSigned) -> Result<(), MsgHandleErrInternal> {
-               let (funding_txo, user_id) = {
-                       let last_block_hash = *self.last_block_hash.read().unwrap();
+               let funding_tx = {
+                       let best_block = *self.best_block.read().unwrap();
                        let mut channel_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_lock;
                        match channel_state.by_id.entry(msg.channel_id) {
@@ -2533,23 +2687,19 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        if chan.get().get_counterparty_node_id() != *counterparty_node_id {
                                                return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
                                        }
-                                       let monitor = match chan.get_mut().funding_signed(&msg, last_block_hash, &self.logger) {
+                                       let (monitor, funding_tx) = match chan.get_mut().funding_signed(&msg, best_block, &self.logger) {
                                                Ok(update) => update,
                                                Err(e) => try_chan_entry!(self, Err(e), channel_state, chan),
                                        };
                                        if let Err(e) = self.chain_monitor.watch_channel(chan.get().get_funding_txo().unwrap(), monitor) {
                                                return_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::RevokeAndACKFirst, false, false);
                                        }
-                                       (chan.get().get_funding_txo().unwrap(), chan.get().get_user_id())
+                                       funding_tx
                                },
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
                        }
                };
-               let mut pending_events = self.pending_events.lock().unwrap();
-               pending_events.push(events::Event::FundingBroadcastSafe {
-                       funding_txo,
-                       user_channel_id: user_id,
-               });
+               self.tx_broadcaster.broadcast_transaction(&funding_tx);
                Ok(())
        }
 
@@ -3189,6 +3339,12 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                        msg: update
                                                                });
                                                        }
+                                                       pending_msg_events.push(events::MessageSendEvent::HandleError {
+                                                               node_id: chan.get_counterparty_node_id(),
+                                                               action: msgs::ErrorAction::SendErrorMessage {
+                                                                       msg: msgs::ErrorMessage { channel_id: chan.channel_id(), data: "Channel force-closed".to_owned() }
+                                                               },
+                                                       });
                                                }
                                        },
                                }
@@ -3211,7 +3367,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        // We cannot broadcast our latest local state via monitor update (as
                        // Channel::force_shutdown tries to make us do) as we may still be in initialization,
                        // so we track the update internally and handle it when the user next calls
-                       // timer_chan_freshness_every_min, guaranteeing we're running normally.
+                       // timer_tick_occurred, guaranteeing we're running normally.
                        if let Some((funding_txo, update)) = failure.0.take() {
                                assert_eq!(update.updates.len(), 1);
                                if let ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } = update.updates[0] {
@@ -3222,6 +3378,99 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        self.finish_force_close_channel(failure);
                }
        }
+
+       fn set_payment_hash_secret_map(&self, payment_hash: PaymentHash, payment_preimage: Option<PaymentPreimage>, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, user_payment_id: u64) -> Result<PaymentSecret, APIError> {
+               assert!(invoice_expiry_delta_secs <= 60*60*24*365); // Sadly bitcoin timestamps are u32s, so panic before 2106
+
+               let payment_secret = PaymentSecret(self.keys_manager.get_secure_random_bytes());
+
+               let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
+               let mut payment_secrets = self.pending_inbound_payments.lock().unwrap();
+               match payment_secrets.entry(payment_hash) {
+                       hash_map::Entry::Vacant(e) => {
+                               e.insert(PendingInboundPayment {
+                                       payment_secret, min_value_msat, user_payment_id, payment_preimage,
+                                       // We assume that highest_seen_timestamp is pretty close to the current time -
+                                       // its updated when we receive a new block with the maximum time we've seen in
+                                       // a header. It should never be more than two hours in the future.
+                                       // Thus, we add two hours here as a buffer to ensure we absolutely
+                                       // never fail a payment too early.
+                                       // Note that we assume that received blocks have reasonably up-to-date
+                                       // timestamps.
+                                       expiry_time: self.highest_seen_timestamp.load(Ordering::Acquire) as u64 + invoice_expiry_delta_secs as u64 + 7200,
+                               });
+                       },
+                       hash_map::Entry::Occupied(_) => return Err(APIError::APIMisuseError { err: "Duplicate payment hash".to_owned() }),
+               }
+               Ok(payment_secret)
+       }
+
+       /// Gets a payment secret and payment hash for use in an invoice given to a third party wishing
+       /// to pay us.
+       ///
+       /// This differs from [`create_inbound_payment_for_hash`] only in that it generates the
+       /// [`PaymentHash`] and [`PaymentPreimage`] for you, returning the first and storing the second.
+       ///
+       /// The [`PaymentPreimage`] will ultimately be returned to you in the [`PaymentReceived`], which
+       /// will have the [`PaymentReceived::payment_preimage`] field filled in. That should then be
+       /// passed directly to [`claim_funds`].
+       ///
+       /// See [`create_inbound_payment_for_hash`] for detailed documentation on behavior and requirements.
+       ///
+       /// [`claim_funds`]: Self::claim_funds
+       /// [`PaymentReceived`]: events::Event::PaymentReceived
+       /// [`PaymentReceived::payment_preimage`]: events::Event::PaymentReceived::payment_preimage
+       /// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash
+       pub fn create_inbound_payment(&self, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, user_payment_id: u64) -> (PaymentHash, PaymentSecret) {
+               let payment_preimage = PaymentPreimage(self.keys_manager.get_secure_random_bytes());
+               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
+
+               (payment_hash,
+                       self.set_payment_hash_secret_map(payment_hash, Some(payment_preimage), min_value_msat, invoice_expiry_delta_secs, user_payment_id)
+                               .expect("RNG Generated Duplicate PaymentHash"))
+       }
+
+       /// Gets a [`PaymentSecret`] for a given [`PaymentHash`], for which the payment preimage is
+       /// stored external to LDK.
+       ///
+       /// A [`PaymentReceived`] event will only be generated if the [`PaymentSecret`] matches a
+       /// payment secret fetched via this method or [`create_inbound_payment`], and which is at least
+       /// the `min_value_msat` provided here, if one is provided.
+       ///
+       /// The [`PaymentHash`] (and corresponding [`PaymentPreimage`]) must be globally unique. This
+       /// method may return an Err if another payment with the same payment_hash is still pending.
+       ///
+       /// `user_payment_id` will be provided back in [`PaymentReceived::user_payment_id`] events to
+       /// allow tracking of which events correspond with which calls to this and
+       /// [`create_inbound_payment`]. `user_payment_id` has no meaning inside of LDK, it is simply
+       /// copied to events and otherwise ignored. It may be used to correlate PaymentReceived events
+       /// with invoice metadata stored elsewhere.
+       ///
+       /// `min_value_msat` should be set if the invoice being generated contains a value. Any payment
+       /// received for the returned [`PaymentHash`] will be required to be at least `min_value_msat`
+       /// before a [`PaymentReceived`] event will be generated, ensuring that we do not provide the
+       /// sender "proof-of-payment" unless they have paid the required amount.
+       ///
+       /// `invoice_expiry_delta_secs` describes the number of seconds that the invoice is valid for
+       /// in excess of the current time. This should roughly match the expiry time set in the invoice.
+       /// After this many seconds, we will remove the inbound payment, resulting in any attempts to
+       /// pay the invoice failing. The BOLT spec suggests 7,200 secs as a default validity time for
+       /// invoices when no timeout is set.
+       ///
+       /// Note that we use block header time to time-out pending inbound payments (with some margin
+       /// to compensate for the inaccuracy of block header timestamps). Thus, in practice we will
+       /// accept a payment and generate a [`PaymentReceived`] event for some time after the expiry.
+       /// If you need exact expiry semantics, you should enforce them upon receipt of
+       /// [`PaymentReceived`].
+       ///
+       /// May panic if `invoice_expiry_delta_secs` is greater than one year.
+       ///
+       /// [`create_inbound_payment`]: Self::create_inbound_payment
+       /// [`PaymentReceived`]: events::Event::PaymentReceived
+       /// [`PaymentReceived::user_payment_id`]: events::Event::PaymentReceived::user_payment_id
+       pub fn create_inbound_payment_for_hash(&self, payment_hash: PaymentHash, min_value_msat: Option<u64>, invoice_expiry_delta_secs: u32, user_payment_id: u64) -> Result<PaymentSecret, APIError> {
+               self.set_payment_hash_secret_map(payment_hash, None, min_value_msat, invoice_expiry_delta_secs, user_payment_id)
+       }
 }
 
 impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> MessageSendEventsProvider for ChannelManager<Signer, M, T, K, F, L>
@@ -3271,34 +3520,132 @@ where
        L::Target: Logger,
 {
        fn block_connected(&self, block: &Block, height: u32) {
+               {
+                       let best_block = self.best_block.read().unwrap();
+                       assert_eq!(best_block.block_hash(), block.header.prev_blockhash,
+                               "Blocks must be connected in chain-order - the connected header must build on the last connected header");
+                       assert_eq!(best_block.height(), height - 1,
+                               "Blocks must be connected in chain-order - the connected block height must be one greater than the previous height");
+               }
+
                let txdata: Vec<_> = block.txdata.iter().enumerate().collect();
-               ChannelManager::block_connected(self, &block.header, &txdata, height);
+               self.transactions_confirmed(&block.header, &txdata, height);
+               self.best_block_updated(&block.header, height);
        }
 
-       fn block_disconnected(&self, header: &BlockHeader, _height: u32) {
-               ChannelManager::block_disconnected(self, header);
+       fn block_disconnected(&self, header: &BlockHeader, height: u32) {
+               let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
+               let new_height = height - 1;
+               {
+                       let mut best_block = self.best_block.write().unwrap();
+                       assert_eq!(best_block.block_hash(), header.block_hash(),
+                               "Blocks must be disconnected in chain-order - the disconnected header must be the last connected header");
+                       assert_eq!(best_block.height(), height,
+                               "Blocks must be disconnected in chain-order - the disconnected block must have the correct height");
+                       *best_block = BestBlock::new(header.prev_blockhash, new_height)
+               }
+
+               self.do_chain_event(Some(new_height), |channel| channel.best_block_updated(new_height, header.time));
        }
 }
 
-impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<Signer, M, T, K, F, L>
-       where M::Target: chain::Watch<Signer>,
-        T::Target: BroadcasterInterface,
-        K::Target: KeysInterface<Signer = Signer>,
-        F::Target: FeeEstimator,
-        L::Target: Logger,
+impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> chain::Confirm for ChannelManager<Signer, M, T, K, F, L>
+where
+       M::Target: chain::Watch<Signer>,
+       T::Target: BroadcasterInterface,
+       K::Target: KeysInterface<Signer = Signer>,
+       F::Target: FeeEstimator,
+       L::Target: Logger,
 {
-       /// Updates channel state based on transactions seen in a connected block.
-       pub fn block_connected(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
+       fn transactions_confirmed(&self, header: &BlockHeader, txdata: &TransactionData, height: u32) {
                // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
                // during initialization prior to the chain_monitor being fully configured in some cases.
                // See the docs for `ChannelManagerReadArgs` for more.
+
+               let block_hash = header.block_hash();
+               log_trace!(self.logger, "{} transactions included in block {} at height {} provided", txdata.len(), block_hash, height);
+
+               let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
+               self.do_chain_event(Some(height), |channel| channel.transactions_confirmed(&block_hash, height, txdata, &self.logger).map(|a| (a, Vec::new())));
+       }
+
+       fn best_block_updated(&self, header: &BlockHeader, height: u32) {
+               // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
+               // during initialization prior to the chain_monitor being fully configured in some cases.
+               // See the docs for `ChannelManagerReadArgs` for more.
+
                let block_hash = header.block_hash();
-               log_trace!(self.logger, "Block {} at height {} connected", block_hash, height);
+               log_trace!(self.logger, "New best block: {} at height {}", block_hash, height);
 
                let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
 
-               self.latest_block_height.store(height as usize, Ordering::Release);
-               *self.last_block_hash.write().unwrap() = block_hash;
+               *self.best_block.write().unwrap() = BestBlock::new(block_hash, height);
+
+               self.do_chain_event(Some(height), |channel| channel.best_block_updated(height, header.time));
+
+               macro_rules! max_time {
+                       ($timestamp: expr) => {
+                               loop {
+                                       // Update $timestamp to be the max of its current value and the block
+                                       // timestamp. This should keep us close to the current time without relying on
+                                       // having an explicit local time source.
+                                       // Just in case we end up in a race, we loop until we either successfully
+                                       // update $timestamp or decide we don't need to.
+                                       let old_serial = $timestamp.load(Ordering::Acquire);
+                                       if old_serial >= header.time as usize { break; }
+                                       if $timestamp.compare_exchange(old_serial, header.time as usize, Ordering::AcqRel, Ordering::Relaxed).is_ok() {
+                                               break;
+                                       }
+                               }
+                       }
+               }
+               max_time!(self.last_node_announcement_serial);
+               max_time!(self.highest_seen_timestamp);
+               let mut payment_secrets = self.pending_inbound_payments.lock().unwrap();
+               payment_secrets.retain(|_, inbound_payment| {
+                       inbound_payment.expiry_time > header.time as u64
+               });
+       }
+
+       fn get_relevant_txids(&self) -> Vec<Txid> {
+               let channel_state = self.channel_state.lock().unwrap();
+               let mut res = Vec::with_capacity(channel_state.short_to_id.len());
+               for chan in channel_state.by_id.values() {
+                       if let Some(funding_txo) = chan.get_funding_txo() {
+                               res.push(funding_txo.txid);
+                       }
+               }
+               res
+       }
+
+       fn transaction_unconfirmed(&self, txid: &Txid) {
+               let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
+               self.do_chain_event(None, |channel| {
+                       if let Some(funding_txo) = channel.get_funding_txo() {
+                               if funding_txo.txid == *txid {
+                                       channel.funding_transaction_unconfirmed().map(|_| (None, Vec::new()))
+                               } else { Ok((None, Vec::new())) }
+                       } else { Ok((None, Vec::new())) }
+               });
+       }
+}
+
+impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<Signer, M, T, K, F, L>
+where
+       M::Target: chain::Watch<Signer>,
+       T::Target: BroadcasterInterface,
+       K::Target: KeysInterface<Signer = Signer>,
+       F::Target: FeeEstimator,
+       L::Target: Logger,
+{
+       /// Calls a function which handles an on-chain event (blocks dis/connected, transactions
+       /// un/confirmed, etc) on each channel, handling any resulting errors or messages generated by
+       /// the function.
+       fn do_chain_event<FN: Fn(&mut Channel<Signer>) -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage>>
+                       (&self, height_opt: Option<u32>, f: FN) {
+               // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
+               // during initialization prior to the chain_monitor being fully configured in some cases.
+               // See the docs for `ChannelManagerReadArgs` for more.
 
                let mut failed_channels = Vec::new();
                let mut timed_out_htlcs = Vec::new();
@@ -3308,7 +3655,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        let short_to_id = &mut channel_state.short_to_id;
                        let pending_msg_events = &mut channel_state.pending_msg_events;
                        channel_state.by_id.retain(|_, channel| {
-                               let res = channel.block_connected(header, txdata, height);
+                               let res = f(channel);
                                if let Ok((chan_res, mut timed_out_pending_htlcs)) = res {
                                        for (source, payment_hash) in timed_out_pending_htlcs.drain(..) {
                                                let chan_update = self.get_channel_update(&channel).map(|u| u.encode_with_len()).unwrap(); // Cannot add/recv HTLCs before we have a short_id so unwrap is safe
@@ -3334,53 +3681,46 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                short_to_id.insert(channel.get_short_channel_id().unwrap(), channel.channel_id());
                                        }
                                } else if let Err(e) = res {
+                                       if let Some(short_id) = channel.get_short_channel_id() {
+                                               short_to_id.remove(&short_id);
+                                       }
+                                       // It looks like our counterparty went on-chain or funding transaction was
+                                       // reorged out of the main chain. Close the channel.
+                                       failed_channels.push(channel.force_shutdown(true));
+                                       if let Ok(update) = self.get_channel_update(&channel) {
+                                               pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
+                                                       msg: update
+                                               });
+                                       }
                                        pending_msg_events.push(events::MessageSendEvent::HandleError {
                                                node_id: channel.get_counterparty_node_id(),
                                                action: msgs::ErrorAction::SendErrorMessage { msg: e },
                                        });
                                        return false;
                                }
-                               if let Some(funding_txo) = channel.get_funding_txo() {
-                                       for &(_, tx) in txdata.iter() {
-                                               for inp in tx.input.iter() {
-                                                       if inp.previous_output == funding_txo.into_bitcoin_outpoint() {
-                                                               log_trace!(self.logger, "Detected channel-closing tx {} spending {}:{}, closing channel {}", tx.txid(), inp.previous_output.txid, inp.previous_output.vout, log_bytes!(channel.channel_id()));
-                                                               if let Some(short_id) = channel.get_short_channel_id() {
-                                                                       short_to_id.remove(&short_id);
-                                                               }
-                                                               // It looks like our counterparty went on-chain. Close the channel.
-                                                               failed_channels.push(channel.force_shutdown(true));
-                                                               if let Ok(update) = self.get_channel_update(&channel) {
-                                                                       pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
-                                                                               msg: update
-                                                                       });
-                                                               }
-                                                               return false;
-                                                       }
-                                               }
-                                       }
-                               }
                                true
                        });
 
-                       channel_state.claimable_htlcs.retain(|&(ref payment_hash, _), htlcs| {
-                               htlcs.retain(|htlc| {
-                                       // If height is approaching the number of blocks we think it takes us to get
-                                       // our commitment transaction confirmed before the HTLC expires, plus the
-                                       // number of blocks we generally consider it to take to do a commitment update,
-                                       // just give up on it and fail the HTLC.
-                                       if height >= htlc.cltv_expiry - HTLC_FAIL_BACK_BUFFER {
-                                               let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
-                                               htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(height));
-                                               timed_out_htlcs.push((HTLCSource::PreviousHopData(htlc.prev_hop.clone()), payment_hash.clone(), HTLCFailReason::Reason {
-                                                       failure_code: 0x4000 | 15,
-                                                       data: htlc_msat_height_data
-                                               }));
-                                               false
-                                       } else { true }
+                       if let Some(height) = height_opt {
+                               channel_state.claimable_htlcs.retain(|payment_hash, htlcs| {
+                                       htlcs.retain(|htlc| {
+                                               // If height is approaching the number of blocks we think it takes us to get
+                                               // our commitment transaction confirmed before the HTLC expires, plus the
+                                               // number of blocks we generally consider it to take to do a commitment update,
+                                               // just give up on it and fail the HTLC.
+                                               if height >= htlc.cltv_expiry - HTLC_FAIL_BACK_BUFFER {
+                                                       let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec();
+                                                       htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(height));
+                                                       timed_out_htlcs.push((HTLCSource::PreviousHopData(htlc.prev_hop.clone()), payment_hash.clone(), HTLCFailReason::Reason {
+                                                               failure_code: 0x4000 | 15,
+                                                               data: htlc_msat_height_data
+                                                       }));
+                                                       false
+                                               } else { true }
+                                       });
+                                       !htlcs.is_empty() // Only retain this entry if htlcs has at least one entry.
                                });
-                               !htlcs.is_empty() // Only retain this entry if htlcs has at least one entry.
-                       });
+                       }
                }
 
                self.handle_init_event_channel_failures(failed_channels);
@@ -3388,59 +3728,6 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                for (source, payment_hash, reason) in timed_out_htlcs.drain(..) {
                        self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), source, &payment_hash, reason);
                }
-
-               loop {
-                       // Update last_node_announcement_serial to be the max of its current value and the
-                       // block timestamp. This should keep us close to the current time without relying on
-                       // having an explicit local time source.
-                       // Just in case we end up in a race, we loop until we either successfully update
-                       // last_node_announcement_serial or decide we don't need to.
-                       let old_serial = self.last_node_announcement_serial.load(Ordering::Acquire);
-                       if old_serial >= header.time as usize { break; }
-                       if self.last_node_announcement_serial.compare_exchange(old_serial, header.time as usize, Ordering::AcqRel, Ordering::Relaxed).is_ok() {
-                               break;
-                       }
-               }
-       }
-
-       /// Updates channel state based on a disconnected block.
-       ///
-       /// If necessary, the channel may be force-closed without letting the counterparty participate
-       /// in the shutdown.
-       pub fn block_disconnected(&self, header: &BlockHeader) {
-               // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
-               // during initialization prior to the chain_monitor being fully configured in some cases.
-               // See the docs for `ChannelManagerReadArgs` for more.
-               let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
-
-               self.latest_block_height.fetch_sub(1, Ordering::AcqRel);
-               *self.last_block_hash.write().unwrap() = header.prev_blockhash;
-
-               let mut failed_channels = Vec::new();
-               {
-                       let mut channel_lock = self.channel_state.lock().unwrap();
-                       let channel_state = &mut *channel_lock;
-                       let short_to_id = &mut channel_state.short_to_id;
-                       let pending_msg_events = &mut channel_state.pending_msg_events;
-                       channel_state.by_id.retain(|_,  v| {
-                               if v.block_disconnected(header) {
-                                       if let Some(short_id) = v.get_short_channel_id() {
-                                               short_to_id.remove(&short_id);
-                                       }
-                                       failed_channels.push(v.force_shutdown(true));
-                                       if let Ok(update) = self.get_channel_update(&v) {
-                                               pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
-                                                       msg: update
-                                               });
-                                       }
-                                       false
-                               } else {
-                                       true
-                               }
-                       });
-               }
-
-               self.handle_init_event_channel_failures(failed_channels);
        }
 
        /// Blocks until ChannelManager needs to be persisted or a timeout is reached. It returns a bool
@@ -3789,7 +4076,8 @@ impl Writeable for PendingHTLCInfo {
                        },
                        &PendingHTLCRouting::Receive { ref payment_data, ref incoming_cltv_expiry } => {
                                1u8.write(writer)?;
-                               payment_data.write(writer)?;
+                               payment_data.payment_secret.write(writer)?;
+                               payment_data.total_msat.write(writer)?;
                                incoming_cltv_expiry.write(writer)?;
                        },
                }
@@ -3810,7 +4098,10 @@ impl Readable for PendingHTLCInfo {
                                        short_channel_id: Readable::read(reader)?,
                                },
                                1u8 => PendingHTLCRouting::Receive {
-                                       payment_data: Readable::read(reader)?,
+                                       payment_data: msgs::FinalOnionHopData {
+                                               payment_secret: Readable::read(reader)?,
+                                               total_msat: Readable::read(reader)?,
+                                       },
                                        incoming_cltv_expiry: Readable::read(reader)?,
                                },
                                _ => return Err(DecodeError::InvalidValue),
@@ -3882,12 +4173,29 @@ impl_writeable!(HTLCPreviousHopData, 0, {
        incoming_packet_shared_secret
 });
 
-impl_writeable!(ClaimableHTLC, 0, {
-       prev_hop,
-       value,
-       payment_data,
-       cltv_expiry
-});
+impl Writeable for ClaimableHTLC {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+               self.prev_hop.write(writer)?;
+               self.value.write(writer)?;
+               self.payment_data.payment_secret.write(writer)?;
+               self.payment_data.total_msat.write(writer)?;
+               self.cltv_expiry.write(writer)
+       }
+}
+
+impl Readable for ClaimableHTLC {
+       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+               Ok(ClaimableHTLC {
+                       prev_hop: Readable::read(reader)?,
+                       value: Readable::read(reader)?,
+                       payment_data: msgs::FinalOnionHopData {
+                               payment_secret: Readable::read(reader)?,
+                               total_msat: Readable::read(reader)?,
+                       },
+                       cltv_expiry: Readable::read(reader)?,
+               })
+       }
+}
 
 impl Writeable for HTLCSource {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
@@ -3989,6 +4297,14 @@ impl Readable for HTLCForwardInfo {
        }
 }
 
+impl_writeable!(PendingInboundPayment, 0, {
+       payment_secret,
+       expiry_time,
+       user_payment_id,
+       payment_preimage,
+       min_value_msat
+});
+
 impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelManager<Signer, M, T, K, F, L>
        where M::Target: chain::Watch<Signer>,
         T::Target: BroadcasterInterface,
@@ -4003,8 +4319,11 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable f
                writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
 
                self.genesis_hash.write(writer)?;
-               (self.latest_block_height.load(Ordering::Acquire) as u32).write(writer)?;
-               self.last_block_hash.read().unwrap().write(writer)?;
+               {
+                       let best_block = self.best_block.read().unwrap();
+                       best_block.height().write(writer)?;
+                       best_block.block_hash().write(writer)?;
+               }
 
                let channel_state = self.channel_state.lock().unwrap();
                let mut unfunded_channels = 0;
@@ -4065,6 +4384,14 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable f
                }
 
                (self.last_node_announcement_serial.load(Ordering::Acquire) as u32).write(writer)?;
+               (self.highest_seen_timestamp.load(Ordering::Acquire) as u32).write(writer)?;
+
+               let pending_inbound_payments = self.pending_inbound_payments.lock().unwrap();
+               (pending_inbound_payments.len() as u64).write(writer)?;
+               for (hash, pending_payment) in pending_inbound_payments.iter() {
+                       hash.write(writer)?;
+                       pending_payment.write(writer)?;
+               }
 
                Ok(())
        }
@@ -4196,8 +4523,8 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                }
 
                let genesis_hash: BlockHash = Readable::read(reader)?;
-               let latest_block_height: u32 = Readable::read(reader)?;
-               let last_block_hash: BlockHash = Readable::read(reader)?;
+               let best_block_height: u32 = Readable::read(reader)?;
+               let best_block_hash: BlockHash = Readable::read(reader)?;
 
                let mut failed_htlcs = Vec::new();
 
@@ -4295,6 +4622,15 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                }
 
                let last_node_announcement_serial: u32 = Readable::read(reader)?;
+               let highest_seen_timestamp: u32 = Readable::read(reader)?;
+
+               let pending_inbound_payment_count: u64 = Readable::read(reader)?;
+               let mut pending_inbound_payments: HashMap<PaymentHash, PendingInboundPayment> = HashMap::with_capacity(cmp::min(pending_inbound_payment_count as usize, MAX_ALLOC_SIZE/(3*32)));
+               for _ in 0..pending_inbound_payment_count {
+                       if pending_inbound_payments.insert(Readable::read(reader)?, Readable::read(reader)?).is_some() {
+                               return Err(DecodeError::InvalidValue);
+                       }
+               }
 
                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&args.keys_manager.get_secure_random_bytes());
@@ -4305,9 +4641,7 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                        chain_monitor: args.chain_monitor,
                        tx_broadcaster: args.tx_broadcaster,
 
-                       latest_block_height: AtomicUsize::new(latest_block_height as usize),
-                       last_block_hash: RwLock::new(last_block_hash),
-                       secp_ctx,
+                       best_block: RwLock::new(BestBlock::new(best_block_hash, best_block_height)),
 
                        channel_state: Mutex::new(ChannelHolder {
                                by_id,
@@ -4316,9 +4650,14 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                                claimable_htlcs,
                                pending_msg_events: Vec::new(),
                        }),
+                       pending_inbound_payments: Mutex::new(pending_inbound_payments),
+
                        our_network_key: args.keys_manager.get_node_secret(),
+                       our_network_pubkey: PublicKey::from_secret_key(&secp_ctx, &args.keys_manager.get_node_secret()),
+                       secp_ctx,
 
                        last_node_announcement_serial: AtomicUsize::new(last_node_announcement_serial as usize),
+                       highest_seen_timestamp: AtomicUsize::new(highest_seen_timestamp as usize),
 
                        per_peer_state: RwLock::new(per_peer_state),
 
@@ -4339,7 +4678,7 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                //TODO: Broadcast channel update for closed channels, but only after we've made a
                //connection or two.
 
-               Ok((last_block_hash.clone(), channel_manager))
+               Ok((best_block_hash.clone(), channel_manager))
        }
 }
 
@@ -4393,3 +4732,155 @@ mod tests {
                }
        }
 }
+
+#[cfg(all(any(test, feature = "_test_utils"), feature = "unstable"))]
+pub mod bench {
+       use chain::Listen;
+       use chain::chainmonitor::ChainMonitor;
+       use chain::channelmonitor::Persist;
+       use chain::keysinterface::{KeysManager, InMemorySigner};
+       use ln::channelmanager::{BestBlock, ChainParameters, ChannelManager, PaymentHash, PaymentPreimage};
+       use ln::features::{InitFeatures, InvoiceFeatures};
+       use ln::functional_test_utils::*;
+       use ln::msgs::ChannelMessageHandler;
+       use routing::network_graph::NetworkGraph;
+       use routing::router::get_route;
+       use util::test_utils;
+       use util::config::UserConfig;
+       use util::events::{Event, EventsProvider, MessageSendEvent, MessageSendEventsProvider};
+
+       use bitcoin::hashes::Hash;
+       use bitcoin::hashes::sha256::Hash as Sha256;
+       use bitcoin::{Block, BlockHeader, Transaction, TxOut};
+
+       use std::sync::Mutex;
+
+       use test::Bencher;
+
+       struct NodeHolder<'a, P: Persist<InMemorySigner>> {
+               node: &'a ChannelManager<InMemorySigner,
+                       &'a ChainMonitor<InMemorySigner, &'a test_utils::TestChainSource,
+                               &'a test_utils::TestBroadcaster, &'a test_utils::TestFeeEstimator,
+                               &'a test_utils::TestLogger, &'a P>,
+                       &'a test_utils::TestBroadcaster, &'a KeysManager,
+                       &'a test_utils::TestFeeEstimator, &'a test_utils::TestLogger>
+       }
+
+       #[cfg(test)]
+       #[bench]
+       fn bench_sends(bench: &mut Bencher) {
+               bench_two_sends(bench, test_utils::TestPersister::new(), test_utils::TestPersister::new());
+       }
+
+       pub fn bench_two_sends<P: Persist<InMemorySigner>>(bench: &mut Bencher, persister_a: P, persister_b: P) {
+               // Do a simple benchmark of sending a payment back and forth between two nodes.
+               // Note that this is unrealistic as each payment send will require at least two fsync
+               // calls per node.
+               let network = bitcoin::Network::Testnet;
+               let genesis_hash = bitcoin::blockdata::constants::genesis_block(network).header.block_hash();
+
+               let tx_broadcaster = test_utils::TestBroadcaster{txn_broadcasted: Mutex::new(Vec::new())};
+               let fee_estimator = test_utils::TestFeeEstimator { sat_per_kw: 253 };
+
+               let mut config: UserConfig = Default::default();
+               config.own_channel_config.minimum_depth = 1;
+
+               let logger_a = test_utils::TestLogger::with_id("node a".to_owned());
+               let chain_monitor_a = ChainMonitor::new(None, &tx_broadcaster, &logger_a, &fee_estimator, &persister_a);
+               let seed_a = [1u8; 32];
+               let keys_manager_a = KeysManager::new(&seed_a, 42, 42);
+               let node_a = ChannelManager::new(&fee_estimator, &chain_monitor_a, &tx_broadcaster, &logger_a, &keys_manager_a, config.clone(), ChainParameters {
+                       network,
+                       best_block: BestBlock::from_genesis(network),
+               });
+               let node_a_holder = NodeHolder { node: &node_a };
+
+               let logger_b = test_utils::TestLogger::with_id("node a".to_owned());
+               let chain_monitor_b = ChainMonitor::new(None, &tx_broadcaster, &logger_a, &fee_estimator, &persister_b);
+               let seed_b = [2u8; 32];
+               let keys_manager_b = KeysManager::new(&seed_b, 42, 42);
+               let node_b = ChannelManager::new(&fee_estimator, &chain_monitor_b, &tx_broadcaster, &logger_b, &keys_manager_b, config.clone(), ChainParameters {
+                       network,
+                       best_block: BestBlock::from_genesis(network),
+               });
+               let node_b_holder = NodeHolder { node: &node_b };
+
+               node_a.create_channel(node_b.get_our_node_id(), 8_000_000, 100_000_000, 42, None).unwrap();
+               node_b.handle_open_channel(&node_a.get_our_node_id(), InitFeatures::known(), &get_event_msg!(node_a_holder, MessageSendEvent::SendOpenChannel, node_b.get_our_node_id()));
+               node_a.handle_accept_channel(&node_b.get_our_node_id(), InitFeatures::known(), &get_event_msg!(node_b_holder, MessageSendEvent::SendAcceptChannel, node_a.get_our_node_id()));
+
+               let tx;
+               if let Event::FundingGenerationReady { temporary_channel_id, output_script, .. } = get_event!(node_a_holder, Event::FundingGenerationReady) {
+                       tx = Transaction { version: 2, lock_time: 0, input: Vec::new(), output: vec![TxOut {
+                               value: 8_000_000, script_pubkey: output_script,
+                       }]};
+                       node_a.funding_transaction_generated(&temporary_channel_id, tx.clone()).unwrap();
+               } else { panic!(); }
+
+               node_b.handle_funding_created(&node_a.get_our_node_id(), &get_event_msg!(node_a_holder, MessageSendEvent::SendFundingCreated, node_b.get_our_node_id()));
+               node_a.handle_funding_signed(&node_b.get_our_node_id(), &get_event_msg!(node_b_holder, MessageSendEvent::SendFundingSigned, node_a.get_our_node_id()));
+
+               assert_eq!(&tx_broadcaster.txn_broadcasted.lock().unwrap()[..], &[tx.clone()]);
+
+               let block = Block {
+                       header: BlockHeader { version: 0x20000000, prev_blockhash: genesis_hash, merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 },
+                       txdata: vec![tx],
+               };
+               Listen::block_connected(&node_a, &block, 1);
+               Listen::block_connected(&node_b, &block, 1);
+
+               node_a.handle_funding_locked(&node_b.get_our_node_id(), &get_event_msg!(node_b_holder, MessageSendEvent::SendFundingLocked, node_a.get_our_node_id()));
+               node_b.handle_funding_locked(&node_a.get_our_node_id(), &get_event_msg!(node_a_holder, MessageSendEvent::SendFundingLocked, node_b.get_our_node_id()));
+
+               let dummy_graph = NetworkGraph::new(genesis_hash);
+
+               let mut payment_count: u64 = 0;
+               macro_rules! send_payment {
+                       ($node_a: expr, $node_b: expr) => {
+                               let usable_channels = $node_a.list_usable_channels();
+                               let route = get_route(&$node_a.get_our_node_id(), &dummy_graph, &$node_b.get_our_node_id(), Some(InvoiceFeatures::known()),
+                                       Some(&usable_channels.iter().map(|r| r).collect::<Vec<_>>()), &[], 10_000, TEST_FINAL_CLTV, &logger_a).unwrap();
+
+                               let mut payment_preimage = PaymentPreimage([0; 32]);
+                               payment_preimage.0[0..8].copy_from_slice(&payment_count.to_le_bytes());
+                               payment_count += 1;
+                               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner());
+                               let payment_secret = $node_b.create_inbound_payment_for_hash(payment_hash, None, 7200, 0).unwrap();
+
+                               $node_a.send_payment(&route, payment_hash, &Some(payment_secret)).unwrap();
+                               let payment_event = SendEvent::from_event($node_a.get_and_clear_pending_msg_events().pop().unwrap());
+                               $node_b.handle_update_add_htlc(&$node_a.get_our_node_id(), &payment_event.msgs[0]);
+                               $node_b.handle_commitment_signed(&$node_a.get_our_node_id(), &payment_event.commitment_msg);
+                               let (raa, cs) = get_revoke_commit_msgs!(NodeHolder { node: &$node_b }, $node_a.get_our_node_id());
+                               $node_a.handle_revoke_and_ack(&$node_b.get_our_node_id(), &raa);
+                               $node_a.handle_commitment_signed(&$node_b.get_our_node_id(), &cs);
+                               $node_b.handle_revoke_and_ack(&$node_a.get_our_node_id(), &get_event_msg!(NodeHolder { node: &$node_a }, MessageSendEvent::SendRevokeAndACK, $node_b.get_our_node_id()));
+
+                               expect_pending_htlcs_forwardable!(NodeHolder { node: &$node_b });
+                               expect_payment_received!(NodeHolder { node: &$node_b }, payment_hash, payment_secret, 10_000);
+                               assert!($node_b.claim_funds(payment_preimage));
+
+                               match $node_b.get_and_clear_pending_msg_events().pop().unwrap() {
+                                       MessageSendEvent::UpdateHTLCs { node_id, updates } => {
+                                               assert_eq!(node_id, $node_a.get_our_node_id());
+                                               $node_a.handle_update_fulfill_htlc(&$node_b.get_our_node_id(), &updates.update_fulfill_htlcs[0]);
+                                               $node_a.handle_commitment_signed(&$node_b.get_our_node_id(), &updates.commitment_signed);
+                                       },
+                                       _ => panic!("Failed to generate claim event"),
+                               }
+
+                               let (raa, cs) = get_revoke_commit_msgs!(NodeHolder { node: &$node_a }, $node_b.get_our_node_id());
+                               $node_b.handle_revoke_and_ack(&$node_a.get_our_node_id(), &raa);
+                               $node_b.handle_commitment_signed(&$node_a.get_our_node_id(), &cs);
+                               $node_a.handle_revoke_and_ack(&$node_b.get_our_node_id(), &get_event_msg!(NodeHolder { node: &$node_b }, MessageSendEvent::SendRevokeAndACK, $node_a.get_our_node_id()));
+
+                               expect_payment_sent!(NodeHolder { node: &$node_a }, payment_preimage);
+                       }
+               }
+
+               bench.iter(|| {
+                       send_payment!(node_a, node_b);
+                       send_payment!(node_b, node_a);
+               });
+       }
+}