}
/// There are a few "states" and then a number of flags which can be applied:
-/// We first move through init with OurInitSent -> TheirInitSent -> FundingCreated -> FundingSent.
-/// TheirChannelReady and OurChannelReady then get set on FundingSent, and when both are set we
-/// move on to ChannelReady.
-/// Note that PeerDisconnected can be set on both ChannelReady and FundingSent.
-/// ChannelReady can then get all remaining flags set on it, until we finish shutdown, then we
-/// move on to ShutdownComplete, at which point most calls into this channel are disallowed.
+/// We first move through init with `OurInitSent` -> `TheirInitSent` -> `FundingCreated` -> `FundingSent`.
+/// `TheirChannelReady` and `OurChannelReady` then get set on `FundingSent`, and when both are set we
+/// move on to `ChannelReady`.
+/// Note that `PeerDisconnected` can be set on both `ChannelReady` and `FundingSent`.
+/// `ChannelReady` can then get all remaining flags set on it, until we finish shutdown, then we
+/// move on to `ShutdownComplete`, at which point most calls into this channel are disallowed.
enum ChannelState {
/// Implies we have (or are prepared to) send our open_channel/accept_channel message
OurInitSent = 1 << 0,
- /// Implies we have received their open_channel/accept_channel message
+ /// Implies we have received their `open_channel`/`accept_channel` message
TheirInitSent = 1 << 1,
- /// We have sent funding_created and are awaiting a funding_signed to advance to FundingSent.
- /// Note that this is nonsense for an inbound channel as we immediately generate funding_signed
- /// upon receipt of funding_created, so simply skip this state.
+ /// We have sent `funding_created` and are awaiting a `funding_signed` to advance to `FundingSent`.
+ /// Note that this is nonsense for an inbound channel as we immediately generate `funding_signed`
+ /// upon receipt of `funding_created`, so simply skip this state.
FundingCreated = 4,
- /// Set when we have received/sent funding_created and funding_signed and are thus now waiting
- /// on the funding transaction to confirm. The ChannelReady flags are set to indicate when we
+ /// Set when we have received/sent `funding_created` and `funding_signed` and are thus now waiting
+ /// on the funding transaction to confirm. The `ChannelReady` flags are set to indicate when we
/// and our counterparty consider the funding transaction confirmed.
FundingSent = 8,
- /// Flag which can be set on FundingSent to indicate they sent us a channel_ready message.
- /// Once both TheirChannelReady and OurChannelReady are set, state moves on to ChannelReady.
+ /// Flag which can be set on `FundingSent` to indicate they sent us a `channel_ready` message.
+ /// Once both `TheirChannelReady` and `OurChannelReady` are set, state moves on to `ChannelReady`.
TheirChannelReady = 1 << 4,
- /// Flag which can be set on FundingSent to indicate we sent them a channel_ready message.
- /// Once both TheirChannelReady and OurChannelReady are set, state moves on to ChannelReady.
+ /// Flag which can be set on `FundingSent` to indicate we sent them a `channel_ready` message.
+ /// Once both `TheirChannelReady` and `OurChannelReady` are set, state moves on to `ChannelReady`.
OurChannelReady = 1 << 5,
ChannelReady = 64,
- /// Flag which is set on ChannelReady and FundingSent indicating remote side is considered
- /// "disconnected" and no updates are allowed until after we've done a channel_reestablish
+ /// Flag which is set on `ChannelReady` and `FundingSent` indicating remote side is considered
+ /// "disconnected" and no updates are allowed until after we've done a `channel_reestablish`
/// dance.
PeerDisconnected = 1 << 7,
- /// Flag which is set on ChannelReady, FundingCreated, and FundingSent indicating the user has
- /// told us a ChannelMonitor update is pending async persistence somewhere and we should pause
+ /// Flag which is set on `ChannelReady`, FundingCreated, and `FundingSent` indicating the user has
+ /// told us a `ChannelMonitor` update is pending async persistence somewhere and we should pause
/// sending any outbound messages until they've managed to finish.
MonitorUpdateInProgress = 1 << 8,
/// Flag which implies that we have sent a commitment_signed but are awaiting the responding
/// messages as then we will be unable to determine which HTLCs they included in their
/// revoke_and_ack implicit ACK, so instead we have to hold them away temporarily to be sent
/// later.
- /// Flag is set on ChannelReady.
+ /// Flag is set on `ChannelReady`.
AwaitingRemoteRevoke = 1 << 9,
- /// Flag which is set on ChannelReady or FundingSent after receiving a shutdown message from
+ /// Flag which is set on `ChannelReady` or `FundingSent` after receiving a shutdown message from
/// the remote end. If set, they may not add any new HTLCs to the channel, and we are expected
/// to respond with our own shutdown message when possible.
RemoteShutdownSent = 1 << 10,
- /// Flag which is set on ChannelReady or FundingSent after sending a shutdown message. At this
+ /// Flag which is set on `ChannelReady` or `FundingSent` after sending a shutdown message. At this
/// point, we may not add any new HTLCs to the channel.
LocalShutdownSent = 1 << 11,
/// We've successfully negotiated a closing_signed dance. At this point ChannelManager is about
/// See [`ChannelContext::sent_message_awaiting_response`] for more information.
pub(crate) const DISCONNECT_PEER_AWAITING_RESPONSE_TICKS: usize = 2;
+/// The number of ticks that may elapse while we're waiting for an unfunded outbound/inbound channel
+/// to be promoted to a [`Channel`] since the unfunded channel was created. An unfunded channel
+/// exceeding this age limit will be force-closed and purged from memory.
+pub(crate) const UNFUNDED_CHANNEL_AGE_LIMIT_TICKS: usize = 60;
+
struct PendingChannelMonitorUpdate {
update: ChannelMonitorUpdate,
}
(0, update, required),
});
+/// Contains all state common to unfunded inbound/outbound channels.
+pub(super) struct UnfundedChannelContext {
+ /// A counter tracking how many ticks have elapsed since this unfunded channel was
+ /// created. If this unfunded channel reaches peer has yet to respond after reaching
+ /// `UNFUNDED_CHANNEL_AGE_LIMIT_TICKS`, it will be force-closed and purged from memory.
+ ///
+ /// This is so that we don't keep channels around that haven't progressed to a funded state
+ /// in a timely manner.
+ unfunded_channel_age_ticks: usize,
+}
+
+impl UnfundedChannelContext {
+ /// Determines whether we should force-close and purge this unfunded channel from memory due to it
+ /// having reached the unfunded channel age limit.
+ ///
+ /// This should be called on every [`super::channelmanager::ChannelManager::timer_tick_occurred`].
+ pub fn should_expire_unfunded_channel(&mut self) -> bool {
+ self.unfunded_channel_age_ticks += 1;
+ self.unfunded_channel_age_ticks >= UNFUNDED_CHANNEL_AGE_LIMIT_TICKS
+ }
+}
+
/// Contains everything about the channel including state, and various flags.
pub(super) struct ChannelContext<Signer: ChannelSigner> {
config: LegacyChannelConfig,
&self.channel_type
}
- /// Guaranteed to be Some after both ChannelReady messages have been exchanged (and, thus,
- /// is_usable() returns true).
- /// Allowed in any state (including after shutdown)
+ /// Gets the channel's `short_channel_id`.
+ ///
+ /// Will return `None` if the channel hasn't been confirmed yet.
pub fn get_short_channel_id(&self) -> Option<u64> {
self.short_channel_id
}
}
/// Returns the funding_txo we either got from our peer, or were given by
- /// get_outbound_funding_created.
+ /// get_funding_created.
pub fn get_funding_txo(&self) -> Option<OutPoint> {
self.channel_transaction_parameters.funding_outpoint
}
#[inline]
/// Creates a set of keys for build_commitment_transaction to generate a transaction which we
/// will sign and send to our counterparty.
- /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
+ /// If an Err is returned, it is a ChannelError::Close (for get_funding_created)
fn build_remote_transaction_keys(&self) -> TxCreationKeys {
//TODO: Ensure that the payment_key derived here ends up in the library users' wallet as we
//may see payments to it!
// TODO: We should refactor this to be an Inbound/OutboundChannel until initial setup handshaking
// has been completed, and then turn into a Channel to get compiler-time enforcement of things like
-// calling channel_id() before we're set up or things like get_outbound_funding_signed on an
+// calling channel_id() before we're set up or things like get_funding_signed on an
// inbound channel.
//
// Holder designates channel data owned for the benefit of the user client.
}
impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
- fn check_remote_fee<F: Deref, L: Deref>(fee_estimator: &LowerBoundedFeeEstimator<F>,
- feerate_per_kw: u32, cur_feerate_per_kw: Option<u32>, logger: &L)
- -> Result<(), ChannelError> where F::Target: FeeEstimator, L::Target: Logger,
+ fn check_remote_fee<F: Deref, L: Deref>(
+ channel_type: &ChannelTypeFeatures, fee_estimator: &LowerBoundedFeeEstimator<F>,
+ feerate_per_kw: u32, cur_feerate_per_kw: Option<u32>, logger: &L
+ ) -> Result<(), ChannelError> where F::Target: FeeEstimator, L::Target: Logger,
{
// We only bound the fee updates on the upper side to prevent completely absurd feerates,
// always accepting up to 25 sat/vByte or 10x our fee estimator's "High Priority" fee.
// We generally don't care too much if they set the feerate to something very high, but it
- // could result in the channel being useless due to everything being dust.
- let upper_limit = cmp::max(250 * 25,
- fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64 * 10);
- if feerate_per_kw as u64 > upper_limit {
- return Err(ChannelError::Close(format!("Peer's feerate much too high. Actual: {}. Our expected upper limit: {}", feerate_per_kw, upper_limit)));
- }
- let lower_limit = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background);
+ // could result in the channel being useless due to everything being dust. This doesn't
+ // apply to channels supporting anchor outputs since HTLC transactions are pre-signed with a
+ // zero fee, so their fee is no longer considered to determine dust limits.
+ if !channel_type.supports_anchors_zero_fee_htlc_tx() {
+ let upper_limit = cmp::max(250 * 25,
+ fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64 * 10);
+ if feerate_per_kw as u64 > upper_limit {
+ return Err(ChannelError::Close(format!("Peer's feerate much too high. Actual: {}. Our expected upper limit: {}", feerate_per_kw, upper_limit)));
+ }
+ }
+
+ // We can afford to use a lower bound with anchors than previously since we can now bump
+ // fees when broadcasting our commitment. However, we must still make sure we meet the
+ // minimum mempool feerate, until package relay is deployed, such that we can ensure the
+ // commitment transaction propagates throughout node mempools on its own.
+ let lower_limit_conf_target = if channel_type.supports_anchors_zero_fee_htlc_tx() {
+ ConfirmationTarget::MempoolMinimum
+ } else {
+ ConfirmationTarget::Background
+ };
+ let lower_limit = fee_estimator.bounded_sat_per_1000_weight(lower_limit_conf_target);
// Some fee estimators round up to the next full sat/vbyte (ie 250 sats per kw), causing
// occasional issues with feerate disagreements between an initiator that wants a feerate
// of 1.1 sat/vbyte and a receiver that wants 1.1 rounded up to 2. Thus, we always add 250
if self.context.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned()));
}
- Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw, Some(self.context.feerate_per_kw), logger)?;
+ Channel::<Signer>::check_remote_fee(&self.context.channel_type, fee_estimator, msg.feerate_per_kw, Some(self.context.feerate_per_kw), logger)?;
let feerate_over_dust_buffer = msg.feerate_per_kw > self.context.get_dust_buffer_feerate(None);
self.context.pending_update_fee = Some((msg.feerate_per_kw, FeeUpdateState::RemoteAnnounced));
// something in the handler for the message that prompted this message):
/// Gets an UnsignedChannelAnnouncement for this channel. The channel must be publicly
- /// announceable and available for use (have exchanged ChannelReady messages in both
+ /// announceable and available for use (have exchanged [`ChannelReady`] messages in both
/// directions). Should be used for both broadcasted announcements and in response to an
/// AnnouncementSignatures message from the remote peer.
///
/// closing).
///
/// This will only return ChannelError::Ignore upon failure.
+ ///
+ /// [`ChannelReady`]: crate::ln::msgs::ChannelReady
fn get_channel_announcement<NS: Deref>(
&self, node_signer: &NS, chain_hash: BlockHash, user_config: &UserConfig,
) -> Result<msgs::UnsignedChannelAnnouncement, ChannelError> where NS::Target: NodeSigner {
return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement if the channel is not currently usable".to_owned()));
}
+ let short_channel_id = self.context.get_short_channel_id()
+ .ok_or(ChannelError::Ignore("Cannot get a ChannelAnnouncement if the channel has not been confirmed yet".to_owned()))?;
let node_id = NodeId::from_pubkey(&node_signer.get_node_id(Recipient::Node)
.map_err(|_| ChannelError::Ignore("Failed to retrieve own public key".to_owned()))?);
let counterparty_node_id = NodeId::from_pubkey(&self.context.get_counterparty_node_id());
let msg = msgs::UnsignedChannelAnnouncement {
features: channelmanager::provided_channel_features(&user_config),
chain_hash,
- short_channel_id: self.context.get_short_channel_id().unwrap(),
+ short_channel_id,
node_id_1: if were_node_one { node_id } else { counterparty_node_id },
node_id_2: if were_node_one { counterparty_node_id } else { node_id },
bitcoin_key_1: NodeId::from_pubkey(if were_node_one { &self.context.get_holder_pubkeys().funding_pubkey } else { self.context.counterparty_funding_pubkey() }),
},
Ok(v) => v
};
+ let short_channel_id = match self.context.get_short_channel_id() {
+ Some(scid) => scid,
+ None => return None,
+ };
+
self.context.announcement_sigs_state = AnnouncementSigsState::MessageSent;
Some(msgs::AnnouncementSignatures {
channel_id: self.context.channel_id(),
- short_channel_id: self.context.get_short_channel_id().unwrap(),
+ short_channel_id,
node_signature: our_node_sig,
bitcoin_signature: our_bitcoin_sig,
})
/// A not-yet-funded outbound (from holder) channel using V1 channel establishment.
pub(super) struct OutboundV1Channel<Signer: ChannelSigner> {
pub context: ChannelContext<Signer>,
+ pub unfunded_context: UnfundedChannelContext,
}
impl<Signer: WriteableEcdsaChannelSigner> OutboundV1Channel<Signer> {
let channel_type = Self::get_initial_channel_type(&config, their_features);
debug_assert!(channel_type.is_subset(&channelmanager::provided_channel_type_features(&config)));
- let feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
+ let commitment_conf_target = if channel_type.supports_anchors_zero_fee_htlc_tx() {
+ ConfirmationTarget::MempoolMinimum
+ } else {
+ ConfirmationTarget::Normal
+ };
+ let commitment_feerate = fee_estimator.bounded_sat_per_1000_weight(commitment_conf_target);
let value_to_self_msat = channel_value_satoshis * 1000 - push_msat;
- let commitment_tx_fee = commit_tx_fee_msat(feerate, MIN_AFFORDABLE_HTLC_COUNT, &channel_type);
+ let commitment_tx_fee = commit_tx_fee_msat(commitment_feerate, MIN_AFFORDABLE_HTLC_COUNT, &channel_type);
if value_to_self_msat < commitment_tx_fee {
return Err(APIError::APIMisuseError{ err: format!("Funding amount ({}) can't even pay fee for initial commitment transaction fee of {}.", value_to_self_msat / 1000, commitment_tx_fee / 1000) });
}
short_channel_id: None,
channel_creation_height: current_chain_height,
- feerate_per_kw: feerate,
+ feerate_per_kw: commitment_feerate,
counterparty_dust_limit_satoshis: 0,
holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
counterparty_max_htlc_value_in_flight_msat: 0,
channel_keys_id,
blocked_monitor_updates: Vec::new(),
- }
+ },
+ unfunded_context: UnfundedChannelContext { unfunded_channel_age_ticks: 0 }
})
}
- /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
- fn get_outbound_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
+ /// If an Err is returned, it is a ChannelError::Close (for get_funding_created)
+ fn get_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
let counterparty_keys = self.context.build_remote_transaction_keys();
let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
Ok(self.context.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx)
/// Note that channel_id changes during this call!
/// Do NOT broadcast the funding transaction until after a successful funding_signed call!
/// If an Err is returned, it is a ChannelError::Close.
- pub fn get_outbound_funding_created<L: Deref>(mut self, funding_transaction: Transaction, funding_txo: OutPoint, logger: &L)
+ pub fn get_funding_created<L: Deref>(mut self, funding_transaction: Transaction, funding_txo: OutPoint, logger: &L)
-> Result<(Channel<Signer>, msgs::FundingCreated), (Self, ChannelError)> where L::Target: Logger {
if !self.context.is_outbound() {
panic!("Tried to create outbound funding_created message on an inbound channel!");
self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
self.context.holder_signer.provide_channel_parameters(&self.context.channel_transaction_parameters);
- let signature = match self.get_outbound_funding_created_signature(logger) {
+ let signature = match self.get_funding_created_signature(logger) {
Ok(res) => res,
Err(e) => {
log_error!(logger, "Got bad signatures: {:?}!", e);
/// If we receive an error message, it may only be a rejection of the channel type we tried,
/// not of our ability to open any channel at all. Thus, on error, we should first call this
/// and see if we get a new `OpenChannel` message, otherwise the channel is failed.
- pub(crate) fn maybe_handle_error_without_close(&mut self, chain_hash: BlockHash) -> Result<msgs::OpenChannel, ()> {
+ pub(crate) fn maybe_handle_error_without_close<F: Deref>(
+ &mut self, chain_hash: BlockHash, fee_estimator: &LowerBoundedFeeEstimator<F>
+ ) -> Result<msgs::OpenChannel, ()>
+ where
+ F::Target: FeeEstimator
+ {
if !self.context.is_outbound() || self.context.channel_state != ChannelState::OurInitSent as u32 { return Err(()); }
if self.context.channel_type == ChannelTypeFeatures::only_static_remote_key() {
// We've exhausted our options
// whatever reason.
if self.context.channel_type.supports_anchors_zero_fee_htlc_tx() {
self.context.channel_type.clear_anchors_zero_fee_htlc_tx();
+ self.context.feerate_per_kw = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
assert!(!self.context.channel_transaction_parameters.channel_type_features.supports_anchors_nonzero_fee_htlc_tx());
} else if self.context.channel_type.supports_scid_privacy() {
self.context.channel_type.clear_scid_privacy();
/// A not-yet-funded inbound (from counterparty) channel using V1 channel establishment.
pub(super) struct InboundV1Channel<Signer: ChannelSigner> {
pub context: ChannelContext<Signer>,
+ pub unfunded_context: UnfundedChannelContext,
}
impl<Signer: WriteableEcdsaChannelSigner> InboundV1Channel<Signer> {
if msg.htlc_minimum_msat >= full_channel_value_msat {
return Err(ChannelError::Close(format!("Minimum htlc value ({}) was larger than full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
}
- Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw, None, logger)?;
+ Channel::<Signer>::check_remote_fee(&channel_type, fee_estimator, msg.feerate_per_kw, None, logger)?;
let max_counterparty_selected_contest_delay = u16::min(config.channel_handshake_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
if msg.to_self_delay > max_counterparty_selected_contest_delay {
channel_keys_id,
blocked_monitor_updates: Vec::new(),
- }
+ },
+ unfunded_context: UnfundedChannelContext { unfunded_channel_age_ticks: 0 }
};
Ok(chan)
// arithmetic, causing a panic with debug assertions enabled.
let fee_est = TestFeeEstimator { fee_est: 42 };
let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_est);
- assert!(Channel::<InMemorySigner>::check_remote_fee(&bounded_fee_estimator,
+ assert!(Channel::<InMemorySigner>::check_remote_fee(
+ &ChannelTypeFeatures::only_static_remote_key(), &bounded_fee_estimator,
u32::max_value(), None, &&test_utils::TestLogger::new()).is_err());
}
value: 10000000, script_pubkey: output_script.clone(),
}]};
let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
- let (mut node_a_chan, funding_created_msg) = node_a_chan.get_outbound_funding_created(tx.clone(), funding_outpoint, &&logger).map_err(|_| ()).unwrap();
+ let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, &&logger).map_err(|_| ()).unwrap();
let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
// Node B --> Node A: funding signed
value: 10000000, script_pubkey: output_script.clone(),
}]};
let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
- let (mut node_a_chan, funding_created_msg) = node_a_chan.get_outbound_funding_created(tx.clone(), funding_outpoint, &&logger).map_err(|_| ()).unwrap();
+ let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, &&logger).map_err(|_| ()).unwrap();
let (mut node_b_chan, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
// Node B --> Node A: funding signed
value: 10000000, script_pubkey: output_script.clone(),
}]};
let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
- let (mut node_a_chan, funding_created_msg) = node_a_chan.get_outbound_funding_created(tx.clone(), funding_outpoint, &&logger).map_err(|_| ()).unwrap();
+ let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, &&logger).map_err(|_| ()).unwrap();
let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
// Node B --> Node A: funding signed
projects / rust-lightning / blobdiff