use util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
use util::logger::Logger;
use util::errors::APIError;
-use util::config::{UserConfig, ChannelConfig, ChannelHandshakeLimits};
+use util::config::{UserConfig, ChannelConfig, ChannelHandshakeConfig, ChannelHandshakeLimits};
use util::scid_utils::scid_from_parts;
use io;
pub const ANCHOR_OUTPUT_VALUE_SATOSHI: u64 = 330;
+/// The percentage of the channel value `holder_max_htlc_value_in_flight_msat` used to be set to,
+/// before this was made configurable. The percentage was made configurable in LDK 0.0.107,
+/// although LDK 0.0.104+ enabled serialization of channels with a different value set for
+/// `holder_max_htlc_value_in_flight_msat`.
+pub const MAX_IN_FLIGHT_PERCENT_LEGACY: u8 = 10;
+
/// Maximum `funding_satoshis` value according to the BOLT #2 specification, if
/// `option_support_large_channel` (aka wumbo channels) is not supported.
/// It's 2^24 - 1.
}
impl<Signer: Sign> Channel<Signer> {
- // Convert constants + channel value to limits:
- fn get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis: u64) -> u64 {
- channel_value_satoshis * 1000 / 10 //TODO
+ /// Returns the value to use for `holder_max_htlc_value_in_flight_msat` as a percentage of the
+ /// `channel_value_satoshis` in msat, set through
+ /// [`ChannelHandshakeConfig::max_inbound_htlc_value_in_flight_percent_of_channel`]
+ ///
+ /// The effective percentage is lower bounded by 1% and upper bounded by 100%.
+ ///
+ /// [`ChannelHandshakeConfig::max_inbound_htlc_value_in_flight_percent_of_channel`]: crate::util::config::ChannelHandshakeConfig::max_inbound_htlc_value_in_flight_percent_of_channel
+ fn get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis: u64, config: &ChannelHandshakeConfig) -> u64 {
+ let configured_percent = if config.max_inbound_htlc_value_in_flight_percent_of_channel < 1 {
+ 1
+ } else if config.max_inbound_htlc_value_in_flight_percent_of_channel > 100 {
+ 100
+ } else {
+ config.max_inbound_htlc_value_in_flight_percent_of_channel as u64
+ };
+ channel_value_satoshis * 10 * configured_percent
}
/// Returns a minimum channel reserve value the remote needs to maintain,
counterparty_dust_limit_satoshis: 0,
holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
counterparty_max_htlc_value_in_flight_msat: 0,
- holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis),
+ holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis, &config.own_channel_config),
counterparty_selected_channel_reserve_satoshis: None, // Filled in in accept_channel
holder_selected_channel_reserve_satoshis,
counterparty_htlc_minimum_msat: 0,
counterparty_dust_limit_satoshis: msg.dust_limit_satoshis,
holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
counterparty_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000),
- holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis),
+ holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis, &config.own_channel_config),
counterparty_selected_channel_reserve_satoshis: Some(msg.channel_reserve_satoshis),
holder_selected_channel_reserve_satoshis,
counterparty_htlc_minimum_msat: msg.htlc_minimum_msat,
let chan_type = if self.channel_type != ChannelTypeFeatures::only_static_remote_key() {
Some(&self.channel_type) } else { None };
- // The same logic applies for `holder_selected_channel_reserve_satoshis` and
- // `holder_max_htlc_value_in_flight_msat` values other than the defaults.
+ // The same logic applies for `holder_selected_channel_reserve_satoshis` values other than
+ // the default, and when `holder_max_htlc_value_in_flight_msat` is configured to be set to
+ // a different percentage of the channel value then 10%, which older versions of LDK used
+ // to set it to before the percentage was made configurable.
let serialized_holder_selected_reserve =
if self.holder_selected_channel_reserve_satoshis != Self::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis)
{ Some(self.holder_selected_channel_reserve_satoshis) } else { None };
+
+ let mut old_max_in_flight_percent_config = UserConfig::default().own_channel_config;
+ old_max_in_flight_percent_config.max_inbound_htlc_value_in_flight_percent_of_channel = MAX_IN_FLIGHT_PERCENT_LEGACY;
let serialized_holder_htlc_max_in_flight =
- if self.holder_max_htlc_value_in_flight_msat != Self::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis)
+ if self.holder_max_htlc_value_in_flight_msat != Self::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis, &old_max_in_flight_percent_config)
{ Some(self.holder_max_htlc_value_in_flight_msat) } else { None };
write_tlv_fields!(writer, {
let mut target_closing_feerate_sats_per_kw = None;
let mut monitor_pending_finalized_fulfills = Some(Vec::new());
let mut holder_selected_channel_reserve_satoshis = Some(Self::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis));
- let mut holder_max_htlc_value_in_flight_msat = Some(Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis));
+ let mut holder_max_htlc_value_in_flight_msat = Some(Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis, &UserConfig::default().own_channel_config));
// Prior to supporting channel type negotiation, all of our channels were static_remotekey
// only, so we default to that if none was written.
let mut channel_type = Some(ChannelTypeFeatures::only_static_remote_key());
/// 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
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,
}
}