Enum MaxDustHTLCExposure

pub enum MaxDustHTLCExposure {
    FixedLimitMsat(u64),
    FeeRateMultiplier(u64),
}

Options for how to set the max dust exposure allowed on a channel. See ChannelConfig::max_dust_htlc_exposure for details.

Variants

FixedLimitMsat(u64)

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.

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.

FeeRateMultiplier(u64)

This sets a multiplier on the ConfirmationTarget::MaximumFeeEstimate feerate (in sats/KW) to determine the maximum allowed dust exposure. If this variant is used then the maximum dust exposure in millisatoshis is calculated as: feerate_per_kw * value. For example, with our default value FeeRateMultiplier(10_000):

• 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 * 10_000 = 2,530,000 msats.
• For a fee rate of 30 sat/vByte (7500 sat/KW), the max dust exposure would be 7500 * 50_000 = 75,000,000 msats (0.00075 BTC).

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.

Note that because zero-commitment-fee anchor channels do not allow for feerate updates (and thus never experience dust exposure changes due to feerate shifts, resulting in no force-closes due to dust exposure limits), such channels will calculate their maximum dust exposure using a constant feerate of 250 sat/KW when using this variant. See ChannelHandshakeConfig::negotiate_anchor_zero_fee_commitments to enable such channels.

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.

Trait Implementations

impl Clone for MaxDustHTLCExposure

fn clone(&self) -> MaxDustHTLCExposure

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MaxDustHTLCExposure

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for MaxDustHTLCExposure

fn eq(&self, other: &MaxDustHTLCExposure) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Readable for MaxDustHTLCExposure

fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>

Reads a Self in from the given Read.

impl Writeable for MaxDustHTLCExposure

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<u8>.

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.

impl Copy for MaxDustHTLCExposure

impl Eq for MaxDustHTLCExposure

impl StructuralPartialEq for MaxDustHTLCExposure