//! Various user-configurable channel limits and settings which ChannelManager
//! applies for you.
-use ln::channelmanager::{BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+use crate::ln::channel::MAX_FUNDING_SATOSHIS_NO_WUMBO;
+use crate::ln::channelmanager::{BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
+
+#[cfg(fuzzing)]
+use crate::util::ser::Readable;
/// Configuration we set when applicable.
///
/// Applied only for inbound channels (see ChannelHandshakeLimits::max_minimum_depth for the
/// equivalent limit applied to outbound channels).
///
+ /// A lower-bound of 1 is applied, requiring all channels to have a confirmed commitment
+ /// transaction before operation. If you wish to accept channels with zero confirmations, see
+ /// [`UserConfig::manually_accept_inbound_channels`] and
+ /// [`ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`].
+ ///
/// Default value: 6.
+ ///
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf
pub minimum_depth: u32,
/// Set to the number of blocks we require our counterparty to wait to claim their money (ie
/// the number of blocks we have to punish our counterparty if they broadcast a revoked
/// Default value: 1. If the value is less than 1, it is ignored and set to 1, as is required
/// by the protocol.
pub our_htlc_minimum_msat: u64,
+ /// Sets the percentage of the channel value we will cap the total value of outstanding inbound
+ /// HTLCs to.
+ ///
+ /// This can be set to a value between 1-100, where the value corresponds to the percent of the
+ /// channel value in whole percentages.
+ ///
+ /// Note that:
+ /// * If configured to another value than the default value 10, any new channels created with
+ /// the non default value will cause versions of LDK prior to 0.0.104 to refuse to read the
+ /// `ChannelManager`.
+ ///
+ /// * This caps the total value for inbound HTLCs in-flight only, and there's currently
+ /// no way to configure the cap for the total value of outbound HTLCs in-flight.
+ ///
+ /// * The requirements for your node being online to ensure the safety of HTLC-encumbered funds
+ /// are different from the non-HTLC-encumbered funds. This makes this an important knob to
+ /// restrict exposure to loss due to being offline for too long.
+ /// See [`ChannelHandshakeConfig::our_to_self_delay`] and [`ChannelConfig::cltv_expiry_delta`]
+ /// for more information.
+ ///
+ /// Default value: 10.
+ /// Minimum value: 1, any values less than 1 will be treated as 1 instead.
+ /// Maximum value: 100, any values larger than 100 will be treated as 100 instead.
+ pub max_inbound_htlc_value_in_flight_percent_of_channel: u8,
+ /// If set, we attempt to negotiate the `scid_privacy` (referred to as `scid_alias` in the
+ /// BOLTs) option for outbound private channels. This provides better privacy by not including
+ /// our real on-chain channel UTXO in each invoice and requiring that our counterparty only
+ /// relay HTLCs to us using the channel's SCID alias.
+ ///
+ /// If this option is set, channels may be created that will not be readable by LDK versions
+ /// prior to 0.0.106, causing [`ChannelManager`]'s read method to return a
+ /// [`DecodeError::InvalidValue`].
+ ///
+ /// Note that setting this to true does *not* prevent us from opening channels with
+ /// counterparties that do not support the `scid_alias` option; we will simply fall back to a
+ /// private channel without that option.
+ ///
+ /// Ignored if the channel is negotiated to be announced, see
+ /// [`ChannelHandshakeConfig::announced_channel`] and
+ /// [`ChannelHandshakeLimits::force_announced_channel_preference`] for more.
+ ///
+ /// Default value: false. This value is likely to change to true in the future.
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ /// [`DecodeError::InvalidValue`]: crate::ln::msgs::DecodeError::InvalidValue
+ pub negotiate_scid_privacy: bool,
+ /// Set to announce the channel publicly and notify all nodes that they can route via this
+ /// channel.
+ ///
+ /// This should only be set to true for nodes which expect to be online reliably.
+ ///
+ /// As the node which funds a channel picks this value this will only apply for new outbound
+ /// channels unless [`ChannelHandshakeLimits::force_announced_channel_preference`] is set.
+ ///
+ /// Default value: false.
+ pub announced_channel: bool,
+ /// When set, we commit to an upfront shutdown_pubkey at channel open. If our counterparty
+ /// supports it, they will then enforce the mutual-close output to us matches what we provided
+ /// at intialization, preventing us from closing to an alternate pubkey.
+ ///
+ /// This is set to true by default to provide a slight increase in security, though ultimately
+ /// any attacker who is able to take control of a channel can just as easily send the funds via
+ /// lightning payments, so we never require that our counterparties support this option.
+ ///
+ /// The upfront key committed is provided from [`SignerProvider::get_shutdown_scriptpubkey`].
+ ///
+ /// Default value: true.
+ ///
+ /// [`SignerProvider::get_shutdown_scriptpubkey`]: crate::sign::SignerProvider::get_shutdown_scriptpubkey
+ pub commit_upfront_shutdown_pubkey: bool,
+ /// The Proportion of the channel value to configure as counterparty's channel reserve,
+ /// i.e., `their_channel_reserve_satoshis` for both outbound and inbound channels.
+ ///
+ /// `their_channel_reserve_satoshis` is the minimum balance that the other node has to maintain
+ /// on their side, at all times.
+ /// This ensures that if our counterparty broadcasts a revoked state, we can punish them by
+ /// claiming at least this value on chain.
+ ///
+ /// Channel reserve values greater than 30% could be considered highly unreasonable, since that
+ /// amount can never be used for payments.
+ /// Also, if our selected channel reserve for counterparty and counterparty's selected
+ /// channel reserve for us sum up to equal or greater than channel value, channel negotiations
+ /// will fail.
+ ///
+ /// Note: Versions of LDK earlier than v0.0.104 will fail to read channels with any channel reserve
+ /// other than the default value.
+ ///
+ /// Default value: 1% of channel value, i.e., configured as 10,000 millionths.
+ /// Minimum value: If the calculated proportional value is less than 1000 sats, it will be treated
+ /// as 1000 sats instead, which is a safe implementation-specific lower bound.
+ /// Maximum value: 1,000,000, any values larger than 1 Million will be treated as 1 Million (or 100%)
+ /// instead, although channel negotiations will fail in that case.
+ pub their_channel_reserve_proportional_millionths: u32,
+ /// If set, we attempt to negotiate the `anchors_zero_fee_htlc_tx`option for all future
+ /// channels. This feature requires having a reserve of onchain funds readily available to bump
+ /// transactions in the event of a channel force close to avoid the possibility of losing funds.
+ ///
+ /// Note that if you wish accept inbound channels with anchor outputs, you must enable
+ /// [`UserConfig::manually_accept_inbound_channels`] and manually accept them with
+ /// [`ChannelManager::accept_inbound_channel`]. This is done to give you the chance to check
+ /// whether your reserve of onchain funds is enough to cover the fees for all existing and new
+ /// channels featuring anchor outputs in the event of a force close.
+ ///
+ /// If this option is set, channels may be created that will not be readable by LDK versions
+ /// prior to 0.0.116, causing [`ChannelManager`]'s read method to return a
+ /// [`DecodeError::InvalidValue`].
+ ///
+ /// Note that setting this to true does *not* prevent us from opening channels with
+ /// counterparties that do not support the `anchors_zero_fee_htlc_tx` option; we will simply
+ /// fall back to a `static_remote_key` channel.
+ ///
+ /// LDK will not support the legacy `option_anchors` commitment version due to a discovered
+ /// vulnerability after its deployment. For more context, see the [`SIGHASH_SINGLE + update_fee
+ /// Considered Harmful`] mailing list post.
+ ///
+ /// Default value: false. This value is likely to change to true in the future.
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+ /// [`DecodeError::InvalidValue`]: crate::ln::msgs::DecodeError::InvalidValue
+ /// [`SIGHASH_SINGLE + update_fee Considered Harmful`]: https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-September/002796.html
+ pub negotiate_anchors_zero_fee_htlc_tx: bool,
+
+ /// The maximum number of HTLCs in-flight from our counterparty towards us at the same time.
+ ///
+ /// Increasing the value can help improve liquidity and stability in
+ /// routing at the cost of higher long term disk / DB usage.
+ ///
+ /// Note: Versions of LDK earlier than v0.0.115 will fail to read channels with a configuration
+ /// other than the default value.
+ ///
+ /// Default value: 50
+ /// Maximum value: 483, any values larger will be treated as 483.
+ /// This is the BOLT #2 spec limit on `max_accepted_htlcs`.
+ pub our_max_accepted_htlcs: u16,
}
impl Default for ChannelHandshakeConfig {
minimum_depth: 6,
our_to_self_delay: BREAKDOWN_TIMEOUT,
our_htlc_minimum_msat: 1,
+ max_inbound_htlc_value_in_flight_percent_of_channel: 10,
+ negotiate_scid_privacy: false,
+ announced_channel: false,
+ commit_upfront_shutdown_pubkey: true,
+ their_channel_reserve_proportional_millionths: 10_000,
+ negotiate_anchors_zero_fee_htlc_tx: false,
+ our_max_accepted_htlcs: 50,
}
}
}
+// When fuzzing, we want to allow the fuzzer to pick any configuration parameters. Thus, we
+// implement Readable here in a naive way (which is a bit easier for the fuzzer to handle). We
+// don't really want to ever expose this to users (if we did we'd want to use TLVs).
+#[cfg(fuzzing)]
+impl Readable for ChannelHandshakeConfig {
+ fn read<R: crate::io::Read>(reader: &mut R) -> Result<Self, crate::ln::msgs::DecodeError> {
+ Ok(Self {
+ minimum_depth: Readable::read(reader)?,
+ our_to_self_delay: Readable::read(reader)?,
+ our_htlc_minimum_msat: Readable::read(reader)?,
+ max_inbound_htlc_value_in_flight_percent_of_channel: Readable::read(reader)?,
+ negotiate_scid_privacy: Readable::read(reader)?,
+ announced_channel: Readable::read(reader)?,
+ commit_upfront_shutdown_pubkey: Readable::read(reader)?,
+ their_channel_reserve_proportional_millionths: Readable::read(reader)?,
+ negotiate_anchors_zero_fee_htlc_tx: Readable::read(reader)?,
+ our_max_accepted_htlcs: Readable::read(reader)?,
+ })
+ }
+}
+
/// Optional channel limits which are applied during channel creation.
///
/// These limits are only applied to our counterparty's limits, not our own.
///
-/// Use 0/<type>::max_value() as appropriate to skip checking.
+/// Use 0/`<type>::max_value()` as appropriate to skip checking.
///
/// Provides sane defaults for most configurations.
///
/// are applied mostly only to incoming channels that's not much of a problem.
#[derive(Copy, Clone, Debug)]
pub struct ChannelHandshakeLimits {
- /// Minimum allowed satoshis when a channel is funded, this is supplied by the sender and so
+ /// Minimum allowed satoshis when a channel is funded. This is supplied by the sender and so
/// only applies to inbound channels.
///
/// Default value: 0.
pub min_funding_satoshis: u64,
+ /// Maximum allowed satoshis when a channel is funded. This is supplied by the sender and so
+ /// only applies to inbound channels.
+ ///
+ /// Default value: 2^24 - 1.
+ pub max_funding_satoshis: u64,
/// The remote node sets a limit on the minimum size of HTLCs we can send to them. This allows
/// you to limit the maximum minimum-size they can require.
///
///
/// Default value: 144, or roughly one day and only applies to outbound channels.
pub max_minimum_depth: u32,
+ /// Whether we implicitly trust funding transactions generated by us for our own outbound
+ /// channels to not be double-spent.
+ ///
+ /// If this is set, we assume that our own funding transactions are *never* double-spent, and
+ /// thus we can trust them without any confirmations. This is generally a reasonable
+ /// assumption, given we're the only ones who could ever double-spend it (assuming we have sole
+ /// control of the signing keys).
+ ///
+ /// You may wish to un-set this if you allow the user to (or do in an automated fashion)
+ /// double-spend the funding transaction to RBF with an alternative channel open.
+ ///
+ /// This only applies if our counterparty set their confirmations-required value to 0, and we
+ /// always trust our own funding transaction at 1 confirmation irrespective of this value.
+ /// Thus, this effectively acts as a `min_minimum_depth`, with the only possible values being
+ /// `true` (0) and `false` (1).
+ ///
+ /// Default value: true
+ pub trust_own_funding_0conf: bool,
/// Set to force an incoming channel to match our announced channel preference in
- /// [`ChannelConfig::announced_channel`].
+ /// [`ChannelHandshakeConfig::announced_channel`].
///
/// For a node which is not online reliably, this should be set to true and
- /// [`ChannelConfig::announced_channel`] set to false, ensuring that no announced (aka public)
+ /// [`ChannelHandshakeConfig::announced_channel`] set to false, ensuring that no announced (aka public)
/// channels will ever be opened.
///
/// Default value: true.
fn default() -> Self {
ChannelHandshakeLimits {
min_funding_satoshis: 0,
+ max_funding_satoshis: MAX_FUNDING_SATOSHIS_NO_WUMBO,
max_htlc_minimum_msat: <u64>::max_value(),
min_max_htlc_value_in_flight_msat: 0,
max_channel_reserve_satoshis: <u64>::max_value(),
min_max_accepted_htlcs: 0,
+ trust_own_funding_0conf: true,
max_minimum_depth: 144,
force_announced_channel_preference: true,
their_to_self_delay: MAX_LOCAL_BREAKDOWN_TIMEOUT,
}
}
+// When fuzzing, we want to allow the fuzzer to pick any configuration parameters. Thus, we
+// implement Readable here in a naive way (which is a bit easier for the fuzzer to handle). We
+// don't really want to ever expose this to users (if we did we'd want to use TLVs).
+#[cfg(fuzzing)]
+impl Readable for ChannelHandshakeLimits {
+ fn read<R: crate::io::Read>(reader: &mut R) -> Result<Self, crate::ln::msgs::DecodeError> {
+ Ok(Self {
+ min_funding_satoshis: Readable::read(reader)?,
+ max_funding_satoshis: Readable::read(reader)?,
+ max_htlc_minimum_msat: Readable::read(reader)?,
+ min_max_htlc_value_in_flight_msat: Readable::read(reader)?,
+ max_channel_reserve_satoshis: Readable::read(reader)?,
+ min_max_accepted_htlcs: Readable::read(reader)?,
+ trust_own_funding_0conf: Readable::read(reader)?,
+ max_minimum_depth: Readable::read(reader)?,
+ force_announced_channel_preference: Readable::read(reader)?,
+ their_to_self_delay: Readable::read(reader)?,
+ })
+ }
+}
+
+/// Options for how to set the max dust HTLC exposure allowed on a channel. See
+/// [`ChannelConfig::max_dust_htlc_exposure`] for details.
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum MaxDustHTLCExposure {
+ /// This sets a fixed limit on the total dust exposure in millisatoshis. Setting this too low
+ /// may prevent the sending or receipt of low-value HTLCs on high-traffic nodes, however this
+ /// limit is very important to prevent stealing of large amounts of dust HTLCs by miners
+ /// through [fee griefing
+ /// attacks](https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-May/002714.html).
+ ///
+ /// Note that if the feerate increases significantly, without a manual increase
+ /// to this maximum the channel may be unable to send/receive HTLCs between the maximum dust
+ /// exposure and the new minimum value for HTLCs to be economically viable to claim.
+ FixedLimitMsat(u64),
+ /// This sets a multiplier on the estimated high priority feerate (sats/KW, as obtained from
+ /// [`FeeEstimator`]) to determine the maximum allowed dust exposure. If this variant is used
+ /// then the maximum dust exposure in millisatoshis is calculated as:
+ /// `high_priority_feerate_per_kw * value`. For example, with our default value
+ /// `FeeRateMultiplier(5000)`:
+ ///
+ /// - For the minimum fee rate of 1 sat/vByte (250 sat/KW, although the minimum
+ /// defaults to 253 sats/KW for rounding, see [`FeeEstimator`]), the max dust exposure would
+ /// be 253 * 5000 = 1,265,000 msats.
+ /// - For a fee rate of 30 sat/vByte (7500 sat/KW), the max dust exposure would be
+ /// 7500 * 5000 = 37,500,000 msats.
+ ///
+ /// This allows the maximum dust exposure to automatically scale with fee rate changes.
+ ///
+ /// Note, if you're using a third-party fee estimator, this may leave you more exposed to a
+ /// fee griefing attack, where your fee estimator may purposely overestimate the fee rate,
+ /// causing you to accept more dust HTLCs than you would otherwise.
+ ///
+ /// This variant is primarily meant to serve pre-anchor channels, as HTLC fees being included
+ /// on HTLC outputs means your channel may be subject to more dust exposure in the event of
+ /// increases in fee rate.
+ ///
+ /// # Backwards Compatibility
+ /// This variant only became available in LDK 0.0.116, so if you downgrade to a prior version
+ /// by default this will be set to a [`Self::FixedLimitMsat`] of 5,000,000 msat.
+ ///
+ /// [`FeeEstimator`]: crate::chain::chaininterface::FeeEstimator
+ FeeRateMultiplier(u64),
+}
+
+impl_writeable_tlv_based_enum!(MaxDustHTLCExposure, ;
+ (1, FixedLimitMsat),
+ (3, FeeRateMultiplier),
+);
+
/// Options which apply on a per-channel basis and may change at runtime or based on negotiation
/// with our counterparty.
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct ChannelConfig {
/// Amount (in millionths of a satoshi) charged per satoshi for payments forwarded outbound
/// over the channel.
///
/// [`MIN_CLTV_EXPIRY_DELTA`]: crate::ln::channelmanager::MIN_CLTV_EXPIRY_DELTA
pub cltv_expiry_delta: u16,
- /// Set to announce the channel publicly and notify all nodes that they can route via this
- /// channel.
- ///
- /// This should only be set to true for nodes which expect to be online reliably.
- ///
- /// As the node which funds a channel picks this value this will only apply for new outbound
- /// channels unless [`ChannelHandshakeLimits::force_announced_channel_preference`] is set.
- ///
- /// This cannot be changed after the initial channel handshake.
- ///
- /// Default value: false.
- pub announced_channel: bool,
- /// When set, we commit to an upfront shutdown_pubkey at channel open. If our counterparty
- /// supports it, they will then enforce the mutual-close output to us matches what we provided
- /// at intialization, preventing us from closing to an alternate pubkey.
- ///
- /// This is set to true by default to provide a slight increase in security, though ultimately
- /// any attacker who is able to take control of a channel can just as easily send the funds via
- /// lightning payments, so we never require that our counterparties support this option.
- ///
- /// This cannot be changed after a channel has been initialized.
- ///
- /// Default value: true.
- pub commit_upfront_shutdown_pubkey: bool,
/// Limit our total exposure to in-flight HTLCs which are burned to fees as they are too
/// small to claim on-chain.
///
/// to such payments may be sustantial if there are many dust HTLCs present when the
/// channel is force-closed.
///
- /// This limit is applied for sent, forwarded, and received HTLCs and limits the total
- /// exposure across all three types per-channel. Setting this too low may prevent the
- /// sending or receipt of low-value HTLCs on high-traffic nodes, and this limit is very
- /// important to prevent stealing of dust HTLCs by miners.
+ /// The dust threshold for each HTLC is based on the `dust_limit_satoshis` for each party in a
+ /// channel negotiated throughout the channel open process, along with the fees required to have
+ /// a broadcastable HTLC spending transaction. When a channel supports anchor outputs
+ /// (specifically the zero fee HTLC transaction variant), this threshold no longer takes into
+ /// account the HTLC transaction fee as it is zero. Because of this, you may want to set this
+ /// value to a fixed limit for channels using anchor outputs, while the fee rate multiplier
+ /// variant is primarily intended for use with pre-anchor channels.
+ ///
+ /// The selected limit is applied for sent, forwarded, and received HTLCs and limits the total
+ /// exposure across all three types per-channel.
///
- /// Default value: 5_000_000 msat.
- pub max_dust_htlc_exposure_msat: u64,
+ /// Default value: [`MaxDustHTLCExposure::FeeRateMultiplier`] with a multiplier of 5000.
+ pub max_dust_htlc_exposure: MaxDustHTLCExposure,
/// The additional fee we're willing to pay to avoid waiting for the counterparty's
/// `to_self_delay` to reclaim funds.
///
/// funder/initiator.
///
/// When we are the funder, because we have to pay the channel closing fee, we bound the
- /// acceptable fee by our [`Background`] and [`Normal`] fees, with the upper bound increased by
+ /// acceptable fee by our [`ChannelCloseMinimum`] and [`NonAnchorChannelFee`] fees, with the upper bound increased by
/// this value. Because the on-chain fee we'd pay to force-close the channel is kept near our
- /// [`Normal`] feerate during normal operation, this value represents the additional fee we're
+ /// [`NonAnchorChannelFee`] feerate during normal operation, this value represents the additional fee we're
/// willing to pay in order to avoid waiting for our counterparty's to_self_delay to reclaim our
/// funds.
///
/// When we are not the funder, we require the closing transaction fee pay at least our
- /// [`Background`] fee estimate, but allow our counterparty to pay as much fee as they like.
+ /// [`ChannelCloseMinimum`] fee estimate, but allow our counterparty to pay as much fee as they like.
/// Thus, this value is ignored when we are not the funder.
///
/// Default value: 1000 satoshis.
///
- /// [`Normal`]: crate::chain::chaininterface::ConfirmationTarget::Normal
- /// [`Background`]: crate::chain::chaininterface::ConfirmationTarget::Background
+ /// [`NonAnchorChannelFee`]: crate::chain::chaininterface::ConfirmationTarget::NonAnchorChannelFee
+ /// [`ChannelCloseMinimum`]: crate::chain::chaininterface::ConfirmationTarget::ChannelCloseMinimum
pub force_close_avoidance_max_fee_satoshis: u64,
+ /// If set, allows this channel's counterparty to skim an additional fee off this node's inbound
+ /// HTLCs. Useful for liquidity providers to offload on-chain channel costs to end users.
+ ///
+ /// Usage:
+ /// - The payee will set this option and set its invoice route hints to use [intercept scids]
+ /// generated by this channel's counterparty.
+ /// - The counterparty will get an [`HTLCIntercepted`] event upon payment forward, and call
+ /// [`forward_intercepted_htlc`] with less than the amount provided in
+ /// [`HTLCIntercepted::expected_outbound_amount_msat`]. The difference between the expected and
+ /// actual forward amounts is their fee. See
+ /// <https://github.com/BitcoinAndLightningLayerSpecs/lsp/tree/main/LSPS2#flow-lsp-trusts-client-model>
+ /// for how this feature may be used in the LSP use case.
+ ///
+ /// # Note
+ /// It's important for payee wallet software to verify that [`PaymentClaimable::amount_msat`] is
+ /// as-expected if this feature is activated, otherwise they may lose money!
+ /// [`PaymentClaimable::counterparty_skimmed_fee_msat`] provides the fee taken by the
+ /// counterparty.
+ ///
+ /// # Note
+ /// Switching this config flag on may break compatibility with versions of LDK prior to 0.0.116.
+ /// Unsetting this flag between restarts may lead to payment receive failures.
+ ///
+ /// Default value: false.
+ ///
+ /// [intercept scids]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
+ /// [`forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
+ /// [`HTLCIntercepted`]: crate::events::Event::HTLCIntercepted
+ /// [`HTLCIntercepted::expected_outbound_amount_msat`]: crate::events::Event::HTLCIntercepted::expected_outbound_amount_msat
+ /// [`PaymentClaimable::amount_msat`]: crate::events::Event::PaymentClaimable::amount_msat
+ /// [`PaymentClaimable::counterparty_skimmed_fee_msat`]: crate::events::Event::PaymentClaimable::counterparty_skimmed_fee_msat
+ // TODO: link to bLIP when it's merged
+ pub accept_underpaying_htlcs: bool,
+}
+
+impl ChannelConfig {
+ /// Applies the given [`ChannelConfigUpdate`] as a partial update to the [`ChannelConfig`].
+ pub fn apply(&mut self, update: &ChannelConfigUpdate) {
+ if let Some(forwarding_fee_proportional_millionths) = update.forwarding_fee_proportional_millionths {
+ self.forwarding_fee_proportional_millionths = forwarding_fee_proportional_millionths;
+ }
+ if let Some(forwarding_fee_base_msat) = update.forwarding_fee_base_msat {
+ self.forwarding_fee_base_msat = forwarding_fee_base_msat;
+ }
+ if let Some(cltv_expiry_delta) = update.cltv_expiry_delta {
+ self.cltv_expiry_delta = cltv_expiry_delta;
+ }
+ if let Some(max_dust_htlc_exposure_msat) = update.max_dust_htlc_exposure_msat {
+ self.max_dust_htlc_exposure = max_dust_htlc_exposure_msat;
+ }
+ if let Some(force_close_avoidance_max_fee_satoshis) = update.force_close_avoidance_max_fee_satoshis {
+ self.force_close_avoidance_max_fee_satoshis = force_close_avoidance_max_fee_satoshis;
+ }
+ }
}
impl Default for ChannelConfig {
forwarding_fee_proportional_millionths: 0,
forwarding_fee_base_msat: 1000,
cltv_expiry_delta: 6 * 12, // 6 blocks/hour * 12 hours
+ max_dust_htlc_exposure: MaxDustHTLCExposure::FeeRateMultiplier(5000),
+ force_close_avoidance_max_fee_satoshis: 1000,
+ accept_underpaying_htlcs: false,
+ }
+ }
+}
+
+impl crate::util::ser::Writeable for ChannelConfig {
+ fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), crate::io::Error> {
+ let max_dust_htlc_exposure_msat_fixed_limit = match self.max_dust_htlc_exposure {
+ MaxDustHTLCExposure::FixedLimitMsat(limit) => limit,
+ MaxDustHTLCExposure::FeeRateMultiplier(_) => 5_000_000,
+ };
+ write_tlv_fields!(writer, {
+ (0, self.forwarding_fee_proportional_millionths, required),
+ (1, self.accept_underpaying_htlcs, (default_value, false)),
+ (2, self.forwarding_fee_base_msat, required),
+ (3, self.max_dust_htlc_exposure, required),
+ (4, self.cltv_expiry_delta, required),
+ (6, max_dust_htlc_exposure_msat_fixed_limit, required),
+ // ChannelConfig serialized this field with a required type of 8 prior to the introduction of
+ // LegacyChannelConfig. To make sure that serialization is not compatible with this one, we use
+ // the next required type of 10, which if seen by the old serialization will always fail.
+ (10, self.force_close_avoidance_max_fee_satoshis, required),
+ });
+ Ok(())
+ }
+}
+
+impl crate::util::ser::Readable for ChannelConfig {
+ fn read<R: crate::io::Read>(reader: &mut R) -> Result<Self, crate::ln::msgs::DecodeError> {
+ let mut forwarding_fee_proportional_millionths = 0;
+ let mut accept_underpaying_htlcs = false;
+ let mut forwarding_fee_base_msat = 1000;
+ let mut cltv_expiry_delta = 6 * 12;
+ let mut max_dust_htlc_exposure_msat = None;
+ let mut max_dust_htlc_exposure_enum = None;
+ let mut force_close_avoidance_max_fee_satoshis = 1000;
+ read_tlv_fields!(reader, {
+ (0, forwarding_fee_proportional_millionths, required),
+ (1, accept_underpaying_htlcs, (default_value, false)),
+ (2, forwarding_fee_base_msat, required),
+ (3, max_dust_htlc_exposure_enum, option),
+ (4, cltv_expiry_delta, required),
+ // Has always been written, but became optionally read in 0.0.116
+ (6, max_dust_htlc_exposure_msat, option),
+ (10, force_close_avoidance_max_fee_satoshis, required),
+ });
+ let max_dust_htlc_fixed_limit = max_dust_htlc_exposure_msat.unwrap_or(5_000_000);
+ let max_dust_htlc_exposure_msat = max_dust_htlc_exposure_enum
+ .unwrap_or(MaxDustHTLCExposure::FixedLimitMsat(max_dust_htlc_fixed_limit));
+ Ok(Self {
+ forwarding_fee_proportional_millionths,
+ accept_underpaying_htlcs,
+ forwarding_fee_base_msat,
+ cltv_expiry_delta,
+ max_dust_htlc_exposure: max_dust_htlc_exposure_msat,
+ force_close_avoidance_max_fee_satoshis,
+ })
+ }
+}
+
+/// A parallel struct to [`ChannelConfig`] to define partial updates.
+#[allow(missing_docs)]
+pub struct ChannelConfigUpdate {
+ pub forwarding_fee_proportional_millionths: Option<u32>,
+ pub forwarding_fee_base_msat: Option<u32>,
+ pub cltv_expiry_delta: Option<u16>,
+ pub max_dust_htlc_exposure_msat: Option<MaxDustHTLCExposure>,
+ pub force_close_avoidance_max_fee_satoshis: Option<u64>,
+}
+
+impl Default for ChannelConfigUpdate {
+ fn default() -> ChannelConfigUpdate {
+ ChannelConfigUpdate {
+ forwarding_fee_proportional_millionths: None,
+ forwarding_fee_base_msat: None,
+ cltv_expiry_delta: None,
+ max_dust_htlc_exposure_msat: None,
+ force_close_avoidance_max_fee_satoshis: None,
+ }
+ }
+}
+
+impl From<ChannelConfig> for ChannelConfigUpdate {
+ fn from(config: ChannelConfig) -> ChannelConfigUpdate {
+ ChannelConfigUpdate {
+ forwarding_fee_proportional_millionths: Some(config.forwarding_fee_proportional_millionths),
+ forwarding_fee_base_msat: Some(config.forwarding_fee_base_msat),
+ cltv_expiry_delta: Some(config.cltv_expiry_delta),
+ max_dust_htlc_exposure_msat: Some(config.max_dust_htlc_exposure),
+ force_close_avoidance_max_fee_satoshis: Some(config.force_close_avoidance_max_fee_satoshis),
+ }
+ }
+}
+
+/// Legacy version of [`ChannelConfig`] that stored the static
+/// [`ChannelHandshakeConfig::announced_channel`] and
+/// [`ChannelHandshakeConfig::commit_upfront_shutdown_pubkey`] fields.
+#[derive(Copy, Clone, Debug)]
+pub(crate) struct LegacyChannelConfig {
+ pub(crate) options: ChannelConfig,
+ /// Deprecated but may still be read from. See [`ChannelHandshakeConfig::announced_channel`] to
+ /// set this when opening/accepting a channel.
+ pub(crate) announced_channel: bool,
+ /// Deprecated but may still be read from. See
+ /// [`ChannelHandshakeConfig::commit_upfront_shutdown_pubkey`] to set this when
+ /// opening/accepting a channel.
+ pub(crate) commit_upfront_shutdown_pubkey: bool,
+}
+
+impl Default for LegacyChannelConfig {
+ fn default() -> Self {
+ Self {
+ options: ChannelConfig::default(),
announced_channel: false,
commit_upfront_shutdown_pubkey: true,
- max_dust_htlc_exposure_msat: 5_000_000,
- force_close_avoidance_max_fee_satoshis: 1000,
}
}
}
-impl_writeable_tlv_based!(ChannelConfig, {
- (0, forwarding_fee_proportional_millionths, required),
- (1, max_dust_htlc_exposure_msat, (default_value, 5_000_000)),
- (2, cltv_expiry_delta, required),
- (3, force_close_avoidance_max_fee_satoshis, (default_value, 1000)),
- (4, announced_channel, required),
- (6, commit_upfront_shutdown_pubkey, required),
- (8, forwarding_fee_base_msat, required),
-});
+impl crate::util::ser::Writeable for LegacyChannelConfig {
+ fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), crate::io::Error> {
+ let max_dust_htlc_exposure_msat_fixed_limit = match self.options.max_dust_htlc_exposure {
+ MaxDustHTLCExposure::FixedLimitMsat(limit) => limit,
+ MaxDustHTLCExposure::FeeRateMultiplier(_) => 5_000_000,
+ };
+ write_tlv_fields!(writer, {
+ (0, self.options.forwarding_fee_proportional_millionths, required),
+ (1, max_dust_htlc_exposure_msat_fixed_limit, required),
+ (2, self.options.cltv_expiry_delta, required),
+ (3, self.options.force_close_avoidance_max_fee_satoshis, (default_value, 1000)),
+ (4, self.announced_channel, required),
+ (5, self.options.max_dust_htlc_exposure, required),
+ (6, self.commit_upfront_shutdown_pubkey, required),
+ (8, self.options.forwarding_fee_base_msat, required),
+ });
+ Ok(())
+ }
+}
+
+impl crate::util::ser::Readable for LegacyChannelConfig {
+ fn read<R: crate::io::Read>(reader: &mut R) -> Result<Self, crate::ln::msgs::DecodeError> {
+ let mut forwarding_fee_proportional_millionths = 0;
+ let mut max_dust_htlc_exposure_msat_fixed_limit = None;
+ let mut cltv_expiry_delta = 0;
+ let mut force_close_avoidance_max_fee_satoshis = 1000;
+ let mut announced_channel = false;
+ let mut commit_upfront_shutdown_pubkey = false;
+ let mut forwarding_fee_base_msat = 0;
+ let mut max_dust_htlc_exposure_enum = None;
+ read_tlv_fields!(reader, {
+ (0, forwarding_fee_proportional_millionths, required),
+ // Has always been written, but became optionally read in 0.0.116
+ (1, max_dust_htlc_exposure_msat_fixed_limit, option),
+ (2, cltv_expiry_delta, required),
+ (3, force_close_avoidance_max_fee_satoshis, (default_value, 1000u64)),
+ (4, announced_channel, required),
+ (5, max_dust_htlc_exposure_enum, option),
+ (6, commit_upfront_shutdown_pubkey, required),
+ (8, forwarding_fee_base_msat, required),
+ });
+ let max_dust_htlc_exposure_msat_fixed_limit =
+ max_dust_htlc_exposure_msat_fixed_limit.unwrap_or(5_000_000);
+ let max_dust_htlc_exposure_msat = max_dust_htlc_exposure_enum
+ .unwrap_or(MaxDustHTLCExposure::FixedLimitMsat(max_dust_htlc_exposure_msat_fixed_limit));
+ Ok(Self {
+ options: ChannelConfig {
+ forwarding_fee_proportional_millionths,
+ max_dust_htlc_exposure: max_dust_htlc_exposure_msat,
+ cltv_expiry_delta,
+ force_close_avoidance_max_fee_satoshis,
+ forwarding_fee_base_msat,
+ accept_underpaying_htlcs: false,
+ },
+ announced_channel,
+ commit_upfront_shutdown_pubkey,
+ })
+ }
+}
/// Top-level config which holds ChannelHandshakeLimits and ChannelConfig.
///
/// (but currently with 0 relay fees!)
#[derive(Copy, Clone, Debug)]
pub struct UserConfig {
- /// Channel config that we propose to our counterparty.
- pub own_channel_config: ChannelHandshakeConfig,
- /// Limits applied to our counterparty's proposed channel config settings.
- pub peer_channel_config_limits: ChannelHandshakeLimits,
+ /// Channel handshake config that we propose to our counterparty.
+ pub channel_handshake_config: ChannelHandshakeConfig,
+ /// Limits applied to our counterparty's proposed channel handshake config settings.
+ pub channel_handshake_limits: ChannelHandshakeLimits,
/// Channel config which affects behavior during channel lifetime.
- pub channel_options: ChannelConfig,
+ pub channel_config: ChannelConfig,
/// If this is set to false, we will reject any HTLCs which were to be forwarded over private
/// channels. This prevents us from taking on HTLC-forwarding risk when we intend to run as a
/// node which is not online reliably.
///
/// For nodes which are not online reliably, you should set all channels to *not* be announced
- /// (using [`ChannelConfig::announced_channel`] and
+ /// (using [`ChannelHandshakeConfig::announced_channel`] and
/// [`ChannelHandshakeLimits::force_announced_channel_preference`]) and set this to false to
/// ensure you are not exposed to any forwarding risk.
///
///
/// Default value: false.
pub accept_forwards_to_priv_channels: bool,
+ /// If this is set to false, we do not accept inbound requests to open a new channel.
+ /// Default value: true.
+ pub accept_inbound_channels: bool,
+ /// If this is set to true, the user needs to manually accept inbound requests to open a new
+ /// channel.
+ ///
+ /// When set to true, [`Event::OpenChannelRequest`] will be triggered once a request to open a
+ /// new inbound channel is received through a [`msgs::OpenChannel`] message. In that case, a
+ /// [`msgs::AcceptChannel`] message will not be sent back to the counterparty node unless the
+ /// user explicitly chooses to accept the request.
+ ///
+ /// Default value: false.
+ ///
+ /// [`Event::OpenChannelRequest`]: crate::events::Event::OpenChannelRequest
+ /// [`msgs::OpenChannel`]: crate::ln::msgs::OpenChannel
+ /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel
+ pub manually_accept_inbound_channels: bool,
+ /// If this is set to true, LDK will intercept HTLCs that are attempting to be forwarded over
+ /// fake short channel ids generated via [`ChannelManager::get_intercept_scid`]. Upon HTLC
+ /// intercept, LDK will generate an [`Event::HTLCIntercepted`] which MUST be handled by the user.
+ ///
+ /// Setting this to true may break backwards compatibility with LDK versions < 0.0.113.
+ ///
+ /// Default value: false.
+ ///
+ /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
+ /// [`Event::HTLCIntercepted`]: crate::events::Event::HTLCIntercepted
+ pub accept_intercept_htlcs: bool,
+ /// If this is set to false, when receiving a keysend payment we'll fail it if it has multiple
+ /// parts. If this is set to true, we'll accept the payment.
+ ///
+ /// Setting this to true will break backwards compatibility upon downgrading to an LDK
+ /// version < 0.0.116 while receiving an MPP keysend. If we have already received an MPP
+ /// keysend, downgrading will cause us to fail to deserialize [`ChannelManager`].
+ ///
+ /// Default value: false.
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ pub accept_mpp_keysend: bool,
}
impl Default for UserConfig {
fn default() -> Self {
UserConfig {
- own_channel_config: ChannelHandshakeConfig::default(),
- peer_channel_config_limits: ChannelHandshakeLimits::default(),
- channel_options: ChannelConfig::default(),
+ channel_handshake_config: ChannelHandshakeConfig::default(),
+ channel_handshake_limits: ChannelHandshakeLimits::default(),
+ channel_config: ChannelConfig::default(),
accept_forwards_to_priv_channels: false,
+ accept_inbound_channels: true,
+ manually_accept_inbound_channels: false,
+ accept_intercept_htlcs: false,
+ accept_mpp_keysend: false,
}
}
}
+
+// When fuzzing, we want to allow the fuzzer to pick any configuration parameters. Thus, we
+// implement Readable here in a naive way (which is a bit easier for the fuzzer to handle). We
+// don't really want to ever expose this to users (if we did we'd want to use TLVs).
+#[cfg(fuzzing)]
+impl Readable for UserConfig {
+ fn read<R: crate::io::Read>(reader: &mut R) -> Result<Self, crate::ln::msgs::DecodeError> {
+ Ok(Self {
+ channel_handshake_config: Readable::read(reader)?,
+ channel_handshake_limits: Readable::read(reader)?,
+ channel_config: Readable::read(reader)?,
+ accept_forwards_to_priv_channels: Readable::read(reader)?,
+ accept_inbound_channels: Readable::read(reader)?,
+ manually_accept_inbound_channels: Readable::read(reader)?,
+ accept_intercept_htlcs: Readable::read(reader)?,
+ accept_mpp_keysend: Readable::read(reader)?,
+ })
+ }
+}
projects / rust-lightning / blobdiff