/// See https://github.com/lightning/bolts/issues/905 for more details.
pub const MIN_CHAN_DUST_LIMIT_SATOSHIS: u64 = 354;
+// Just a reasonable implementation-specific safe lower bound, higher than the dust limit.
+pub const MIN_THEIR_CHAN_RESERVE_SATOSHIS: u64 = 1000;
+
/// Used to return a simple Error back to ChannelManager. Will get converted to a
/// msgs::ErrorAction::SendErrorMessage or msgs::ErrorAction::IgnoreError as appropriate with our
/// channel_id in ChannelManager.
}
/// Returns a minimum channel reserve value the remote needs to maintain,
- /// required by us.
+ /// required by us according to the configured or default
+ /// [`ChannelHandshakeConfig::their_channel_reserve_proportional_millionths`]
///
/// Guaranteed to return a value no larger than channel_value_satoshis
///
- /// This is used both for new channels and to figure out what reserve value we sent to peers
- /// for channels serialized before we included our selected reserve value in the serialized
- /// data explicitly.
- pub(crate) fn get_holder_selected_channel_reserve_satoshis(channel_value_satoshis: u64) -> u64 {
+ /// This is used both for outbound and inbound channels and has lower bound
+ /// of `MIN_THEIR_CHAN_RESERVE_SATOSHIS`.
+ pub(crate) fn get_holder_selected_channel_reserve_satoshis(channel_value_satoshis: u64, config: &UserConfig) -> u64 {
+ let calculated_reserve = channel_value_satoshis.saturating_mul(config.channel_handshake_config.their_channel_reserve_proportional_millionths as u64) / 1_000_000;
+ cmp::min(channel_value_satoshis, cmp::max(calculated_reserve, MIN_THEIR_CHAN_RESERVE_SATOSHIS))
+ }
+
+ /// This is for legacy reasons, present for forward-compatibility.
+ /// LDK versions older than 0.0.104 don't know how read/handle values other than default
+ /// from storage. Hence, we use this function to not persist default values of
+ /// `holder_selected_channel_reserve_satoshis` for channels into storage.
+ pub(crate) fn get_legacy_default_holder_selected_channel_reserve_satoshis(channel_value_satoshis: u64) -> u64 {
let (q, _) = channel_value_satoshis.overflowing_div(100);
- cmp::min(channel_value_satoshis, cmp::max(q, 1000)) //TODO
+ cmp::min(channel_value_satoshis, cmp::max(q, 1000))
}
pub(crate) fn opt_anchors(&self) -> bool {
if holder_selected_contest_delay < BREAKDOWN_TIMEOUT {
return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", holder_selected_contest_delay)});
}
- let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis);
+ let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis, config);
if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
+ // Protocol level safety check in place, although it should never happen because
+ // of `MIN_THEIR_CHAN_RESERVE_SATOSHIS`
return Err(APIError::APIMisuseError { err: format!("Holder selected channel reserve below implemention limit dust_limit_satoshis {}", holder_selected_channel_reserve_satoshis) });
}
}
}
- let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis);
+ let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis, config);
if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
+ // Protocol level safety check in place, although it should never happen because
+ // of `MIN_THEIR_CHAN_RESERVE_SATOSHIS`
return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). dust_limit_satoshis is ({}).", holder_selected_channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
}
if holder_selected_channel_reserve_satoshis * 1000 >= full_channel_value_msat {
- return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). Channel value is ({} - {}).", holder_selected_channel_reserve_satoshis, full_channel_value_msat, msg.push_msat)));
+ return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({})msats. Channel value is ({} - {})msats.", holder_selected_channel_reserve_satoshis * 1000, full_channel_value_msat, msg.push_msat)));
}
if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
log_debug!(logger, "channel_reserve_satoshis ({}) is smaller than our dust limit ({}). We can broadcast stale states without any risk, implying this channel is very insecure for our counterparty.",
// 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)
+ if self.holder_selected_channel_reserve_satoshis != Self::get_legacy_default_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().channel_handshake_config;
let mut announcement_sigs = None;
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_selected_channel_reserve_satoshis = Some(Self::get_legacy_default_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, &UserConfig::default().channel_handshake_config));
// Prior to supporting channel type negotiation, all of our channels were static_remotekey
// only, so we default to that if none was written.
#[cfg(test)]
mod tests {
+ use std::cmp;
use bitcoin::blockdata::script::{Script, Builder};
use bitcoin::blockdata::transaction::{Transaction, TxOut};
use bitcoin::blockdata::constants::genesis_block;
use ln::PaymentHash;
use ln::channelmanager::{HTLCSource, PaymentId};
use ln::channel::{Channel, InboundHTLCOutput, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator};
- use ln::channel::{MAX_FUNDING_SATOSHIS_NO_WUMBO, TOTAL_BITCOIN_SUPPLY_SATOSHIS};
+ use ln::channel::{MAX_FUNDING_SATOSHIS_NO_WUMBO, TOTAL_BITCOIN_SUPPLY_SATOSHIS, MIN_THEIR_CHAN_RESERVE_SATOSHIS};
use ln::features::{InitFeatures, ChannelTypeFeatures};
use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate};
use ln::script::ShutdownScript;
assert_eq!(chan_8.holder_max_htlc_value_in_flight_msat, chan_8_value_msat);
}
+ #[test]
+ fn test_configured_holder_selected_channel_reserve_satoshis() {
+
+ // Test that `new_outbound` and `new_from_req` create a channel with the correct
+ // channel reserves, when `their_channel_reserve_proportional_millionths` is configured.
+ test_self_and_counterparty_channel_reserve(10_000_000, 0.02, 0.02);
+
+ // Test with valid but unreasonably high channel reserves
+ // Requesting and accepting parties have requested for 49%-49% and 60%-30% channel reserve
+ test_self_and_counterparty_channel_reserve(10_000_000, 0.49, 0.49);
+ test_self_and_counterparty_channel_reserve(10_000_000, 0.60, 0.30);
+
+ // Test with calculated channel reserve less than lower bound
+ // i.e `MIN_THEIR_CHAN_RESERVE_SATOSHIS`
+ test_self_and_counterparty_channel_reserve(100_000, 0.00002, 0.30);
+
+ // Test with invalid channel reserves since sum of both is greater than or equal
+ // to channel value
+ test_self_and_counterparty_channel_reserve(10_000_000, 0.50, 0.50);
+ test_self_and_counterparty_channel_reserve(10_000_000, 0.60, 0.50);
+ }
+
+ fn test_self_and_counterparty_channel_reserve(channel_value_satoshis: u64, outbound_selected_channel_reserve_perc: f64, inbound_selected_channel_reserve_perc: f64) {
+ let fee_est = LowerBoundedFeeEstimator::new(&TestFeeEstimator { fee_est: 15_000 });
+ let logger = test_utils::TestLogger::new();
+ let secp_ctx = Secp256k1::new();
+ let seed = [42; 32];
+ let network = Network::Testnet;
+ let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
+ let outbound_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+ let inbound_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
+
+
+ let mut outbound_node_config = UserConfig::default();
+ outbound_node_config.channel_handshake_config.their_channel_reserve_proportional_millionths = (outbound_selected_channel_reserve_perc * 1_000_000.0) as u32;
+ let chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, outbound_node_id, &InitFeatures::known(), channel_value_satoshis, 100_000, 42, &outbound_node_config, 0, 42).unwrap();
+
+ let expected_outbound_selected_chan_reserve = cmp::max(MIN_THEIR_CHAN_RESERVE_SATOSHIS, (chan.channel_value_satoshis as f64 * outbound_selected_channel_reserve_perc) as u64);
+ assert_eq!(chan.holder_selected_channel_reserve_satoshis, expected_outbound_selected_chan_reserve);
+
+ let chan_open_channel_msg = chan.get_open_channel(genesis_block(network).header.block_hash());
+ let mut inbound_node_config = UserConfig::default();
+ inbound_node_config.channel_handshake_config.their_channel_reserve_proportional_millionths = (inbound_selected_channel_reserve_perc * 1_000_000.0) as u32;
+
+ if outbound_selected_channel_reserve_perc + inbound_selected_channel_reserve_perc < 1.0 {
+ let chan_inbound_node = Channel::<EnforcingSigner>::new_from_req(&&fee_est, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42).unwrap();
+
+ let expected_inbound_selected_chan_reserve = cmp::max(MIN_THEIR_CHAN_RESERVE_SATOSHIS, (chan.channel_value_satoshis as f64 * inbound_selected_channel_reserve_perc) as u64);
+
+ assert_eq!(chan_inbound_node.holder_selected_channel_reserve_satoshis, expected_inbound_selected_chan_reserve);
+ assert_eq!(chan_inbound_node.counterparty_selected_channel_reserve_satoshis.unwrap(), expected_outbound_selected_chan_reserve);
+ } else {
+ // Channel Negotiations failed
+ let result = Channel::<EnforcingSigner>::new_from_req(&&fee_est, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42);
+ assert!(result.is_err());
+ }
+ }
+
#[test]
fn channel_update() {
let feeest = LowerBoundedFeeEstimator::new(&TestFeeEstimator{fee_est: 15000});
// Instantiate channel parameters where we push the maximum msats given our
// funding satoshis
let channel_value_sat = 31337; // same as funding satoshis
- let channel_reserve_satoshis = Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(channel_value_sat);
+ let channel_reserve_satoshis = Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(channel_value_sat, &cfg);
let push_msat = (channel_value_sat - channel_reserve_satoshis) * 1000;
// Have node0 initiate a channel to node1 with aforementioned parameters
let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+ let default_config = UserConfig::default();
// Have node0 initiate a channel to node1 with aforementioned parameters
let mut push_amt = 100_000_000;
let feerate_per_kw = 253;
let opt_anchors = false;
push_amt -= feerate_per_kw as u64 * (commitment_tx_base_weight(opt_anchors) + 4 * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000 * 1000;
- push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000) * 1000;
+ push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000, &default_config) * 1000;
let temp_channel_id = nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, if send_from_initiator { 0 } else { push_amt }, 42, None).unwrap();
let mut open_channel_message = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, channel_value, push_sats * 1000, InitFeatures::known(), InitFeatures::known());
let channel_id = chan.2;
let secp_ctx = Secp256k1::new();
- let bs_channel_reserve_sats = Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(channel_value);
+ let default_config = UserConfig::default();
+ let bs_channel_reserve_sats = Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(channel_value, &default_config);
let opt_anchors = false;
let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
-
+ let default_config = UserConfig::default();
let opt_anchors = false;
let mut push_amt = 100_000_000;
push_amt -= commit_tx_fee_msat(feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT as u64, opt_anchors);
- push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000) * 1000;
+
+ push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000, &default_config) * 1000;
let _ = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100_000, push_amt, InitFeatures::known(), InitFeatures::known());
let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
-
+ let default_config = UserConfig::default();
let opt_anchors = false;
// Set nodes[0]'s balance such that they will consider any above-dust received HTLC to be a
// transaction fee with 0 HTLCs (183 sats)).
let mut push_amt = 100_000_000;
push_amt -= commit_tx_fee_msat(feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT as u64, opt_anchors);
- push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000) * 1000;
+ push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000, &default_config) * 1000;
let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100_000, push_amt, InitFeatures::known(), InitFeatures::known());
// Send four HTLCs to cover the initial push_msat buffer we're required to include
let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None, None]);
let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
-
+ let default_config = UserConfig::default();
let opt_anchors = false;
// Set nodes[0]'s balance such that they will consider any above-dust received HTLC to be a
// transaction fee with 0 HTLCs (183 sats)).
let mut push_amt = 100_000_000;
push_amt -= commit_tx_fee_msat(feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT as u64, opt_anchors);
- push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000) * 1000;
+ push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000, &default_config) * 1000;
create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, push_amt, InitFeatures::known(), InitFeatures::known());
let dust_amt = crate::ln::channel::MIN_CHAN_DUST_LIMIT_SATOSHIS * 1000
let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
-
+ let default_config = UserConfig::default();
let opt_anchors = false;
// Set the push_msat amount such that nodes[0] will not be able to afford to add even a single
// During open, we don't have a "counterparty channel reserve" to check against, so that
// requirement only comes into play on the open_channel handling side.
- push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000) * 1000;
+ push_amt -= Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000, &default_config) * 1000;
nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100_000, push_amt, 42, None).unwrap();
let mut open_channel_msg = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
open_channel_msg.push_msat += 1;
let _ = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000, InitFeatures::known(), InitFeatures::known());
let channels0 = node_chanmgrs[0].list_channels();
let channels1 = node_chanmgrs[1].list_channels();
+ let default_config = UserConfig::default();
assert_eq!(channels0.len(), 1);
assert_eq!(channels1.len(), 1);
- let reserve = Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100000);
+ let reserve = Channel::<EnforcingSigner>::get_holder_selected_channel_reserve_satoshis(100_000, &default_config);
assert_eq!(channels0[0].inbound_capacity_msat, 95000000 - reserve*1000);
assert_eq!(channels1[0].outbound_capacity_msat, 95000000 - reserve*1000);
///
/// [`KeysInterface::get_shutdown_scriptpubkey`]: crate::chain::keysinterface::KeysInterface::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
}
impl Default for ChannelHandshakeConfig {
negotiate_scid_privacy: false,
announced_channel: false,
commit_upfront_shutdown_pubkey: true,
+ their_channel_reserve_proportional_millionths: 10_000,
}
}
}
projects / rust-lightning / commitdiff