}
/**
- * Limit our total exposure to in-flight HTLCs which are burned to fees as they are too
- * small to claim on-chain.
+ * Limit our total exposure to potential loss to on-chain fees on close, including in-flight
+ * HTLCs which are burned to fees as they are too small to claim on-chain and fees on
+ * commitment transaction(s) broadcasted by our counterparty in excess of our own fee estimate.
+ *
+ * # HTLC-based Dust Exposure
*
* When an HTLC present in one of our channels is below a \"dust\" threshold, the HTLC will
* not be claimable on-chain, instead being turned into additional miner fees if either
* party force-closes the channel. Because the threshold is per-HTLC, our total exposure
- * to such payments may be sustantial if there are many dust HTLCs present when the
+ * to such payments may be substantial if there are many dust HTLCs present when the
* channel is force-closed.
*
* 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.
- *
- * 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.
- *
- * Default value: 5_000_000 msat.
+ * 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.
+ *
+ * # Transaction Fee Dust Exposure
+ *
+ * Further, counterparties broadcasting a commitment transaction in a force-close may result
+ * in other balance being burned to fees, and thus all fees on commitment and HTLC
+ * transactions in excess of our local fee estimates are included in the dust calculation.
+ *
+ * Because of this, another way to look at this limit is to divide it by 43,000 (or 218,750
+ * for non-anchor channels) and see it as the maximum feerate disagreement (in sats/vB) per
+ * non-dust HTLC we're allowed to have with our peers before risking a force-closure for
+ * inbound channels.
+ *
+ * Thus, for the default value of 10_000 * a current feerate estimate of 10 sat/vB (or 2,500
+ * sat/KW), we risk force-closure if we disagree with our peer by:
+ * `10_000 * 2_500 / 43_000 / (483*2)` = 0.6 sat/vB for anchor channels with 483 HTLCs in
+ * both directions (the maximum),
+ * `10_000 * 2_500 / 43_000 / (50*2)` = 5.8 sat/vB for anchor channels with 50 HTLCs in both
+ * directions (the LDK default max from [`ChannelHandshakeConfig::our_max_accepted_htlcs`])
+ * `10_000 * 2_500 / 218_750 / (483*2)` = 0.1 sat/vB for non-anchor channels with 483 HTLCs
+ * in both directions (the maximum),
+ * `10_000 * 2_500 / 218_750 / (50*2)` = 1.1 sat/vB for non-anchor channels with 50 HTLCs
+ * in both (the LDK default maximum from [`ChannelHandshakeConfig::our_max_accepted_htlcs`])
+ *
+ * Note that when using [`MaxDustHTLCExposure::FeeRateMultiplier`] this maximum disagreement
+ * will scale linearly with increases (or decreases) in the our feerate estimates. Further,
+ * for anchor channels we expect our counterparty to use a relatively low feerate estimate
+ * while we use [`ConfirmationTarget::OnChainSweep`] (which should be relatively high) and
+ * feerate disagreement force-closures should only occur when theirs is higher than ours.
+ *
+ * Default value: [`MaxDustHTLCExposure::FeeRateMultiplier`] with a multiplier of 10_000.
+ *
+ * [`ConfirmationTarget::OnChainSweep`]: crate::chain::chaininterface::ConfirmationTarget::OnChainSweep
*/
- public long get_max_dust_htlc_exposure_msat() {
- long ret = bindings.ChannelConfig_get_max_dust_htlc_exposure_msat(this.ptr);
+ public MaxDustHTLCExposure get_max_dust_htlc_exposure() {
+ long ret = bindings.ChannelConfig_get_max_dust_htlc_exposure(this.ptr);
Reference.reachabilityFence(this);
- return ret;
+ if (ret >= 0 && ret <= 4096) { return null; }
+ org.ldk.structs.MaxDustHTLCExposure ret_hu_conv = org.ldk.structs.MaxDustHTLCExposure.constr_from_ptr(ret);
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(this); };
+ return ret_hu_conv;
}
/**
- * Limit our total exposure to in-flight HTLCs which are burned to fees as they are too
- * small to claim on-chain.
+ * Limit our total exposure to potential loss to on-chain fees on close, including in-flight
+ * HTLCs which are burned to fees as they are too small to claim on-chain and fees on
+ * commitment transaction(s) broadcasted by our counterparty in excess of our own fee estimate.
+ *
+ * # HTLC-based Dust Exposure
*
* When an HTLC present in one of our channels is below a \"dust\" threshold, the HTLC will
* not be claimable on-chain, instead being turned into additional miner fees if either
* party force-closes the channel. Because the threshold is per-HTLC, our total exposure
- * to such payments may be sustantial if there are many dust HTLCs present when the
+ * to such payments may be substantial if there are many dust HTLCs present when the
* channel is force-closed.
*
* 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.
- *
- * 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.
- *
- * Default value: 5_000_000 msat.
+ * 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.
+ *
+ * # Transaction Fee Dust Exposure
+ *
+ * Further, counterparties broadcasting a commitment transaction in a force-close may result
+ * in other balance being burned to fees, and thus all fees on commitment and HTLC
+ * transactions in excess of our local fee estimates are included in the dust calculation.
+ *
+ * Because of this, another way to look at this limit is to divide it by 43,000 (or 218,750
+ * for non-anchor channels) and see it as the maximum feerate disagreement (in sats/vB) per
+ * non-dust HTLC we're allowed to have with our peers before risking a force-closure for
+ * inbound channels.
+ *
+ * Thus, for the default value of 10_000 * a current feerate estimate of 10 sat/vB (or 2,500
+ * sat/KW), we risk force-closure if we disagree with our peer by:
+ * `10_000 * 2_500 / 43_000 / (483*2)` = 0.6 sat/vB for anchor channels with 483 HTLCs in
+ * both directions (the maximum),
+ * `10_000 * 2_500 / 43_000 / (50*2)` = 5.8 sat/vB for anchor channels with 50 HTLCs in both
+ * directions (the LDK default max from [`ChannelHandshakeConfig::our_max_accepted_htlcs`])
+ * `10_000 * 2_500 / 218_750 / (483*2)` = 0.1 sat/vB for non-anchor channels with 483 HTLCs
+ * in both directions (the maximum),
+ * `10_000 * 2_500 / 218_750 / (50*2)` = 1.1 sat/vB for non-anchor channels with 50 HTLCs
+ * in both (the LDK default maximum from [`ChannelHandshakeConfig::our_max_accepted_htlcs`])
+ *
+ * Note that when using [`MaxDustHTLCExposure::FeeRateMultiplier`] this maximum disagreement
+ * will scale linearly with increases (or decreases) in the our feerate estimates. Further,
+ * for anchor channels we expect our counterparty to use a relatively low feerate estimate
+ * while we use [`ConfirmationTarget::OnChainSweep`] (which should be relatively high) and
+ * feerate disagreement force-closures should only occur when theirs is higher than ours.
+ *
+ * Default value: [`MaxDustHTLCExposure::FeeRateMultiplier`] with a multiplier of 10_000.
+ *
+ * [`ConfirmationTarget::OnChainSweep`]: crate::chain::chaininterface::ConfirmationTarget::OnChainSweep
*/
- public void set_max_dust_htlc_exposure_msat(long val) {
- bindings.ChannelConfig_set_max_dust_htlc_exposure_msat(this.ptr, val);
+ public void set_max_dust_htlc_exposure(org.ldk.structs.MaxDustHTLCExposure val) {
+ bindings.ChannelConfig_set_max_dust_htlc_exposure(this.ptr, val.ptr);
Reference.reachabilityFence(this);
Reference.reachabilityFence(val);
+ if (this != null) { this.ptrs_to.add(val); };
}
/**
* 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
*/
public long get_force_close_avoidance_max_fee_satoshis() {
long ret = bindings.ChannelConfig_get_force_close_avoidance_max_fee_satoshis(this.ptr);
* 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
*/
public void set_force_close_avoidance_max_fee_satoshis(long val) {
bindings.ChannelConfig_set_force_close_avoidance_max_fee_satoshis(this.ptr, val);
Reference.reachabilityFence(val);
}
+ /**
+ * 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
+ */
+ public boolean get_accept_underpaying_htlcs() {
+ boolean ret = bindings.ChannelConfig_get_accept_underpaying_htlcs(this.ptr);
+ Reference.reachabilityFence(this);
+ return ret;
+ }
+
+ /**
+ * 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
+ */
+ public void set_accept_underpaying_htlcs(boolean val) {
+ bindings.ChannelConfig_set_accept_underpaying_htlcs(this.ptr, val);
+ Reference.reachabilityFence(this);
+ Reference.reachabilityFence(val);
+ }
+
/**
* Constructs a new ChannelConfig given each field
*/
- public static ChannelConfig of(int forwarding_fee_proportional_millionths_arg, int forwarding_fee_base_msat_arg, short cltv_expiry_delta_arg, long max_dust_htlc_exposure_msat_arg, long force_close_avoidance_max_fee_satoshis_arg) {
- long ret = bindings.ChannelConfig_new(forwarding_fee_proportional_millionths_arg, forwarding_fee_base_msat_arg, cltv_expiry_delta_arg, max_dust_htlc_exposure_msat_arg, force_close_avoidance_max_fee_satoshis_arg);
+ public static ChannelConfig of(int forwarding_fee_proportional_millionths_arg, int forwarding_fee_base_msat_arg, short cltv_expiry_delta_arg, org.ldk.structs.MaxDustHTLCExposure max_dust_htlc_exposure_arg, long force_close_avoidance_max_fee_satoshis_arg, boolean accept_underpaying_htlcs_arg) {
+ long ret = bindings.ChannelConfig_new(forwarding_fee_proportional_millionths_arg, forwarding_fee_base_msat_arg, cltv_expiry_delta_arg, max_dust_htlc_exposure_arg.ptr, force_close_avoidance_max_fee_satoshis_arg, accept_underpaying_htlcs_arg);
Reference.reachabilityFence(forwarding_fee_proportional_millionths_arg);
Reference.reachabilityFence(forwarding_fee_base_msat_arg);
Reference.reachabilityFence(cltv_expiry_delta_arg);
- Reference.reachabilityFence(max_dust_htlc_exposure_msat_arg);
+ Reference.reachabilityFence(max_dust_htlc_exposure_arg);
Reference.reachabilityFence(force_close_avoidance_max_fee_satoshis_arg);
+ Reference.reachabilityFence(accept_underpaying_htlcs_arg);
if (ret >= 0 && ret <= 4096) { return null; }
org.ldk.structs.ChannelConfig ret_hu_conv = null; if (ret < 0 || ret > 4096) { ret_hu_conv = new org.ldk.structs.ChannelConfig(null, ret); }
if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(ret_hu_conv); };
+ if (ret_hu_conv != null) { ret_hu_conv.ptrs_to.add(max_dust_htlc_exposure_arg); };
return ret_hu_conv;
}
* This ignores pointers and is_owned flags and looks at the values in fields.
* Two objects with NULL inner values will be considered "equal" here.
*/
- public boolean eq(ChannelConfig b) {
- boolean ret = bindings.ChannelConfig_eq(this.ptr, b == null ? 0 : b.ptr);
+ public boolean eq(org.ldk.structs.ChannelConfig b) {
+ boolean ret = bindings.ChannelConfig_eq(this.ptr, b.ptr);
Reference.reachabilityFence(this);
Reference.reachabilityFence(b);
if (this != null) { this.ptrs_to.add(b); };
if (!(o instanceof ChannelConfig)) return false;
return this.eq((ChannelConfig)o);
}
+ /**
+ * Applies the given [`ChannelConfigUpdate`] as a partial update to the [`ChannelConfig`].
+ */
+ public void apply(org.ldk.structs.ChannelConfigUpdate update) {
+ bindings.ChannelConfig_apply(this.ptr, update.ptr);
+ Reference.reachabilityFence(this);
+ Reference.reachabilityFence(update);
+ if (this != null) { this.ptrs_to.add(update); };
+ }
+
/**
* Creates a "default" ChannelConfig. See struct and individual field documentaiton for details on which values are used.
*/