Struct lightning::ln::channelmanager::ChannelManager

pub struct ChannelManager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger,  { /* fields omitted */ }

Manager which keeps track of a number of channels and sends messages to the appropriate channel, also tracking HTLC preimages and forwarding onion packets appropriately.

Implements ChannelMessageHandler, handling the multi-channel parts and passing things through to individual Channels.

Implements Writeable to write out all channel state to disk. Implies peer_disconnected() for all peers during write/read (though does not modify this instance, only the instance being serialized). This will result in any channels which have not yet exchanged funding_created (ie called funding_transaction_generated for outbound channels).

Note that you can be a bit lazier about writing out ChannelManager than you can be with ChannelMonitors. With ChannelMonitors you MUST write each monitor update out to disk before returning from chain::Watch::watch_/update_channel, with ChannelManagers, writing updates happens out-of-band (and will prevent any other ChannelManager operations from occurring during the serialization process). If the deserialized version is out-of-date compared to the ChannelMonitors passed by reference to read(), those channels will be force-closed based on the ChannelMonitor state and no funds will be lost (mod on-chain transaction fees).

Note that the deserializer is only implemented for (BlockHash, ChannelManager), which tells you the last block hash which was block_connect()ed. You MUST rescan any blocks along the “reorg path” (ie call block_disconnected() until you get to a common block and then call block_connected() to step towards your best block) upon deserialization before using the object!

Note that ChannelManager is responsible for tracking liveness of its channels and generating 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_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 essentially you should default to using a SimpleRefChannelManager, and use a SimpleArcChannelManager when you require a ChannelManager with a static lifetime, such as when you’re using lightning-net-tokio.

Implementations

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<Signer, M, T, K, F, L> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

pub fn new(
    fee_est: F,
    chain_monitor: M,
    tx_broadcaster: T,
    logger: L,
    keys_manager: K,
    config: UserConfig,
    params: ChainParameters
) -> Self

Constructs a new ChannelManager to hold several channels and route between them.

This is the main “logic hub” for all channel-related actions, and implements ChannelMessageHandler.

Non-proportional fees are fixed according to our risk using the provided fee estimator.

panics if channel_value_satoshis is >= MAX_FUNDING_SATOSHIS!

Users need to notify the new ChannelManager when a new block is connected or disconnected using its block_connected and block_disconnected methods, starting from after params.latest_hash.

pub fn get_current_default_configuration(&self) -> &UserConfig

Gets the current configuration applied to all new channels, as

pub fn create_channel(
    &self,
    their_network_key: PublicKey,
    channel_value_satoshis: u64,
    push_msat: u64,
    user_id: u64,
    override_config: Option<UserConfig>
) -> Result<(), APIError>

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 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.

Raises APIError::APIMisuseError when channel_value_satoshis > 2**24 or push_msat is greater than channel_value_satoshis * 1k or channel_value_satoshis is < 1000.

Note that we do not check if you are currently connected to the given peer. If no connection is available, the outbound open_channel message may fail to send, resulting in the channel eventually being silently forgotten.

pub fn list_channels(&self) -> Vec<ChannelDetails>

Gets the list of open channels, in random order. See ChannelDetail field documentation for more information.

pub fn list_usable_channels(&self) -> Vec<ChannelDetails>

Gets the list of usable channels, in random order. Useful as an argument to get_route to ensure non-announced channels are used.

These are guaranteed to have their ChannelDetails::is_usable value set to true, see the documentation for ChannelDetails::is_usable for more info on exactly what the criteria are.

pub fn close_channel(&self, channel_id: &[u8; 32]) -> Result<(), APIError>

Begins the process of closing a channel. After this call (plus some timeout), no new HTLCs will be accepted on the given channel, and after additional timeout/the closing of all pending HTLCs, the channel will be closed on chain.

May generate a SendShutdown message event on success, which should be relayed.

pub fn force_close_channel(&self, channel_id: &[u8; 32]) -> Result<(), APIError>

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_all_channels(&self)

Force close all channels, immediately broadcasting the latest local commitment transaction for each to the chain and rejecting new HTLCs on each.

pub fn send_payment(
    &self,
    route: &Route,
    payment_hash: PaymentHash,
    payment_secret: &Option<PaymentSecret>
) -> Result<(), PaymentSendFailure>

Sends a payment along a given route.

Value parameters are provided via the last hop in route, see documentation for RouteHop fields for more info.

Note that if the payment_hash already exists elsewhere (eg you’re sending a duplicative payment), we don’t do anything to stop you! We always try to ensure that if the provided next hop knows the preimage to payment_hash they can claim an additional amount as specified in the last hop in the route! Thus, you should probably do your own payment_preimage tracking (which you should already be doing as they represent “proof of payment”) and prevent double-sends yourself.

May generate SendHTLCs message(s) event on success, which should be relayed.

Each path may have a different return value, and PaymentSendValue may return a Vec with each entry matching the corresponding-index entry in the route paths, see PaymentSendFailure for more info.

In general, a path may raise:

• APIError::RouteError when an invalid route or forwarding parameter (cltv_delta, fee, node public key) is specified.
• APIError::ChannelUnavailable if the next-hop channel is not available for updates (including due to previous monitor update failure or new permanent monitor update failure).
• APIError::MonitorUpdateFailed if a new monitor update failure prevented sending the relevant updates.

Note that depending on the type of the PaymentSendFailure the HTLC may have been irrevocably committed to on our end. In such a case, do NOT retry the payment with a different route unless you intend to pay twice!

payment_secret is unrelated to payment_hash (or PaymentPreimage) and exists to authenticate the sender to the recipient and prevent payment-probing (deanonymization) attacks. For newer nodes, it will be provided to you in the invoice. If you do not have one, the Route must not contain multiple paths as multi-path payments require a recipient-provided payment_secret. If a payment_secret is provided, we assume that the invoice had the payment_secret feature bit set (either as required or as available). If multiple paths are present in the Route, we assume the invoice had the basic_mpp feature set.

pub fn funding_transaction_generated(
    &self,
    temporary_channel_id: &[u8; 32],
    funding_transaction: Transaction
) -> Result<(), APIError>

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 broadcast_node_announcement(
    &self,
    rgb: [u8; 3],
    alias: [u8; 32],
    addresses: Vec<NetAddress>
)

Regenerates channel_announcements and generates a signed node_announcement from the given arguments, providing them in corresponding events via get_and_clear_pending_msg_events, if at least one public channel has been confirmed on-chain. This effectively re-broadcasts all channel announcements and sends our node announcement to ensure that the lightning P2P network is aware of the channels we have and our network addresses.

rgb is a node “color” and alias is a printable human-readable string to describe this node to humans. They carry no in-protocol meaning.

addresses represent the set (possibly empty) of socket addresses on which this node accepts incoming connections. These will be included in the node_announcement, publicly tying these addresses together and to this node. If you wish to preserve user privacy, addresses should likely contain only Tor Onion addresses.

Panics if addresses is absurdly large (more than 500).

pub fn process_pending_htlc_forwards(&self)

Processes HTLCs which are pending waiting on random forward delay.

Should only really ever be called in response to a PendingHTLCsForwardable event. Will likely generate further events.

pub fn timer_tick_occurred(&self)

If a peer is disconnected we mark any channels with that peer as ‘disabled’. After some time, if channels are still disabled we need to broadcast a ChannelUpdate to inform the network about the uselessness of these channels.

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 fail_htlc_backwards(&self, payment_hash: &PaymentHash) -> bool

Indicates that the preimage for payment_hash is unknown or the received amount is incorrect after a PaymentReceived event, failing the HTLC back to its origin and freeing resources 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 claim_funds(&self, payment_preimage: PaymentPreimage) -> bool

Provides a payment preimage in response to a PaymentReceived event, returning true and 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!

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 get_our_node_id(&self) -> PublicKey

Gets the node_id held by this ChannelManager

pub fn channel_monitor_updated(
    &self,
    funding_txo: &OutPoint,
    highest_applied_update_id: u64
)

Restores a single, given channel to normal operation after a ChannelMonitorUpdateErr::TemporaryFailure was returned from a channel monitor update operation.

All ChannelMonitor updates up to and including highest_applied_update_id must have been fully committed in every copy of the given channels’ ChannelMonitors.

Note that there is no effect to calling with a highest_applied_update_id other than the current latest ChannelMonitorUpdate and one call to this function after multiple ChannelMonitorUpdateErr::TemporaryFailures is fine. The highest_applied_update_id field exists largely only to prevent races between this and concurrent update_monitor calls.

Thus, the anticipated use is, at a high level:

1. You register a chain::Watch with this ChannelManager,
2. it stores each update to disk, and begins updating any remote (eg watchtower) copies of said ChannelMonitors as it can, returning ChannelMonitorUpdateErr::TemporaryFailures any time it cannot do so instantly,
3. update(s) are applied to each remote copy of a ChannelMonitor,
4. once all remote copies are updated, you call this function with the update_id that completed, and once it is the latest the Channel will be re-enabled.

pub fn create_inbound_payment(
    &self,
    min_value_msat: Option<u64>,
    invoice_expiry_delta_secs: u32,
    user_payment_id: u64
) -> (PaymentHash, PaymentSecret)

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.

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>

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 3,600 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.

Pending inbound payments are stored in memory and in serialized versions of this ChannelManager. If potentially unbounded numbers of inbound payments may exist and space is limited, you may wish to rate-limit inbound payment creation.

May panic if invoice_expiry_delta_secs is greater than one year.

Note that invoices generated for inbound payments should have their min_final_cltv_expiry set to at least MIN_FINAL_CLTV_EXPIRY.

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelManager<Signer, M, T, K, F, L> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

pub fn await_persistable_update_timeout(&self, max_wait: Duration) -> bool

Blocks until ChannelManager needs to be persisted or a timeout is reached. It returns a bool indicating whether persistence is necessary. Only one listener on await_persistable_update or await_persistable_update_timeout is guaranteed to be woken up. Note that the feature allow_wallclock_use must be enabled to use this function.

pub fn await_persistable_update(&self)

Blocks until ChannelManager needs to be persisted. Only one listener on await_persistable_update or await_persistable_update_timeout is guaranteed to be woken up.

pub fn current_best_block(&self) -> BestBlock

Gets the latest best block which was connected either via the chain::Listen or chain::Confirm interfaces.

Trait Implementations

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMessageHandler for ChannelManager<Signer, M, T, K, F, L> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

fn handle_open_channel(
    &self,
    counterparty_node_id: &PublicKey,
    their_features: InitFeatures,
    msg: &OpenChannel
)

Handle an incoming open_channel message from the given peer.

fn handle_accept_channel(
    &self,
    counterparty_node_id: &PublicKey,
    their_features: InitFeatures,
    msg: &AcceptChannel
)

Handle an incoming accept_channel message from the given peer.

fn handle_funding_created(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &FundingCreated
)

Handle an incoming funding_created message from the given peer.

fn handle_funding_signed(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &FundingSigned
)

Handle an incoming funding_signed message from the given peer.

fn handle_funding_locked(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &FundingLocked
)

Handle an incoming funding_locked message from the given peer.

fn handle_shutdown(
    &self,
    counterparty_node_id: &PublicKey,
    their_features: &InitFeatures,
    msg: &Shutdown
)

Handle an incoming shutdown message from the given peer.

fn handle_closing_signed(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &ClosingSigned
)

Handle an incoming closing_signed message from the given peer.

fn handle_update_add_htlc(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &UpdateAddHTLC
)

Handle an incoming update_add_htlc message from the given peer.

fn handle_update_fulfill_htlc(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &UpdateFulfillHTLC
)

Handle an incoming update_fulfill_htlc message from the given peer.

fn handle_update_fail_htlc(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &UpdateFailHTLC
)

Handle an incoming update_fail_htlc message from the given peer.

fn handle_update_fail_malformed_htlc(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &UpdateFailMalformedHTLC
)

Handle an incoming update_fail_malformed_htlc message from the given peer.

fn handle_commitment_signed(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &CommitmentSigned
)

Handle an incoming commitment_signed message from the given peer.

fn handle_revoke_and_ack(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &RevokeAndACK
)

Handle an incoming revoke_and_ack message from the given peer.

fn handle_update_fee(&self, counterparty_node_id: &PublicKey, msg: &UpdateFee)

Handle an incoming update_fee message from the given peer.

fn handle_announcement_signatures(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &AnnouncementSignatures
)

Handle an incoming announcement_signatures message from the given peer.

fn handle_channel_update(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &ChannelUpdate
)

Handle an incoming channel update from the given peer.

fn handle_channel_reestablish(
    &self,
    counterparty_node_id: &PublicKey,
    msg: &ChannelReestablish
)

Handle an incoming channel_reestablish message from the given peer.

fn peer_disconnected(
    &self,
    counterparty_node_id: &PublicKey,
    no_connection_possible: bool
)

Indicates a connection to the peer failed/an existing connection was lost. If no connection is believed to be possible in the future (eg they’re sending us messages we don’t understand or indicate they require unknown feature bits), no_connection_possible is set and any outstanding channels should be failed.

fn peer_connected(&self, counterparty_node_id: &PublicKey, init_msg: &Init)

Handle a peer reconnecting, possibly generating channel_reestablish message(s).

fn handle_error(&self, counterparty_node_id: &PublicKey, msg: &ErrorMessage)

Handle an incoming error message from the given peer.

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Confirm for ChannelManager<Signer, M, T, K, F, L> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

fn transactions_confirmed(
    &self,
    header: &BlockHeader,
    txdata: &TransactionData<'_>,
    height: u32
)

Processes transactions confirmed in a block with a given header and height.

fn best_block_updated(&self, header: &BlockHeader, height: u32)

Processes an update to the best header connected at the given height.

fn get_relevant_txids(&self) -> Vec<Txid>

Returns transactions that should be monitored for reorganization out of the chain.

fn transaction_unconfirmed(&self, txid: &Txid)

Processes a transaction that is no longer confirmed as result of a chain reorganization.

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> EventsProvider for ChannelManager<Signer, M, T, K, F, L> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

fn process_pending_events<H: Deref>(&self, handler: H) where
    H::Target: EventHandler, 

Processes events that must be periodically handled.

An EventHandler may safely call back to the provider in order to handle an event. However, it must not call Writeable::write as doing so would result in a deadlock.

Pending events are persisted as part of ChannelManager. While these events are cleared when processed, an EventHandler must be able to handle previously seen events when restarting from an old state.

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Listen for ChannelManager<Signer, M, T, K, F, L> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

fn block_connected(&self, block: &Block, height: u32)

Notifies the listener that a block was added at the given height.

fn block_disconnected(&self, header: &BlockHeader, height: u32)

Notifies the listener that a block was removed at the given height.

impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> MessageSendEventsProvider for ChannelManager<Signer, M, T, K, F, L> where
    M::Target: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>

Gets the list of pending events which were generated by previous actions, clearing the list in the process.

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: Watch<Signer>,
    T::Target: BroadcasterInterface,
    K::Target: KeysInterface<Signer = Signer>,
    F::Target: FeeEstimator,
    L::Target: Logger, 

fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error>

Writes self out to the given Writer

fn encode(&self) -> Vec<u8>

Writes self out to a Vec

fn encode_with_len(&self) -> Vec<u8>

Writes self out to a Vec

fn serialized_length(&self) -> usize

Gets the length of this object after it has been serialized. This can be overridden to optimize cases where we prepend an object with its length.