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Drop max_inbound_htlc_value_in_flight_percent_of_channel #878

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ab0aa16
Adapt to lightning-block-sync API changes
jkczyz Apr 14, 2026
2ab93c1
Expose a bindings-compatible BestBlock
jkczyz Apr 23, 2026
4fda093
Drop max_inbound_htlc_value_in_flight_percent_of_channel
jkczyz Apr 17, 2026
20bae9a
f - Assert unannounced-channel default stays at 100%
jkczyz Apr 28, 2026
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28 changes: 14 additions & 14 deletions Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -40,18 +40,18 @@ default = []
#lightning-macros = { version = "0.2.0" }
#lightning-dns-resolver = { version = "0.3.0" }

lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6" }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-types = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-invoice = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-net-tokio = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-persister = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["tokio"] }
lightning-background-processor = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-rapid-gossip-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-block-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["rest-client", "rpc-client", "tokio"] }
lightning-transaction-sync = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["esplora-async-https", "time", "electrum-rustls-ring"] }
lightning-liquidity = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std"] }
lightning-macros = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }
lightning-dns-resolver = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144" }

bdk_chain = { version = "0.23.0", default-features = false, features = ["std"] }
bdk_esplora = { version = "0.22.0", default-features = false, features = ["async-https-rustls", "tokio"]}
Expand Down Expand Up @@ -81,13 +81,13 @@ async-trait = { version = "0.1", default-features = false }
vss-client = { package = "vss-client-ng", version = "0.5" }
prost = { version = "0.11.6", default-features = false}
#bitcoin-payment-instructions = { version = "0.6" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "a7b32d5fded9bb45f73bf82e6d7187adf705171c" }
bitcoin-payment-instructions = { git = "https://github.com/jkczyz/bitcoin-payment-instructions", rev = "679dac50cc0d81ec4d31da94b93d467e5308f16a" }

[target.'cfg(windows)'.dependencies]
winapi = { version = "0.3", features = ["winbase"] }

[dev-dependencies]
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "38a62c32454d3eac22578144c479dbf9a6d9bff6", features = ["std", "_test_utils"] }
lightning = { git = "https://github.com/lightningdevkit/rust-lightning", rev = "369a2cf9c8ef810deea0cd2b4cf6ed0691b78144", features = ["std", "_test_utils"] }
rand = { version = "0.9.2", default-features = false, features = ["std", "thread_rng", "os_rng"] }
proptest = "1.0.0"
regex = "1.5.6"
Expand Down
6 changes: 0 additions & 6 deletions bindings/ldk_node.udl
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Expand Up @@ -233,12 +233,6 @@ enum NodeError {

typedef dictionary NodeStatus;

[Remote]
dictionary BestBlock {
BlockHash block_hash;
u32 height;
};

typedef enum BuildError;

[Trait, WithForeign]
Expand Down
15 changes: 5 additions & 10 deletions src/builder.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -19,10 +19,10 @@ use bdk_wallet::{KeychainKind, Wallet as BdkWallet};
use bitcoin::bip32::{ChildNumber, Xpriv};
use bitcoin::key::Secp256k1;
use bitcoin::secp256k1::PublicKey;
use bitcoin::{BlockHash, Network};
use bitcoin::Network;
use bitcoin_payment_instructions::dns_resolver::DNSHrnResolver;
use bitcoin_payment_instructions::onion_message_resolver::LDKOnionMessageDNSSECHrnResolver;
use lightning::chain::{chainmonitor, BestBlock};
use lightning::chain::{chainmonitor, BestBlock as BlockLocator};
use lightning::ln::channelmanager::{self, ChainParameters, ChannelManagerReadArgs};
use lightning::ln::msgs::{RoutingMessageHandler, SocketAddress};
use lightning::ln::peer_handler::{IgnoringMessageHandler, MessageHandler};
Expand Down Expand Up @@ -1657,11 +1657,6 @@ fn build_with_store_internal(

// If we act as an LSPS2 service, we allow forwarding to unannounced channels.
user_config.accept_forwards_to_priv_channels = true;

// If we act as an LSPS2 service, set the HTLC-value-in-flight to 100% of the channel value
// to ensure we can forward the initial payment.
user_config.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel =
100;
Comment on lines -1661 to -1664
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@tankyleo tankyleo Apr 28, 2026

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To confirm here I don't think setting 100% here would have helped as that maximum only applies to the inbound HTLCs on that channel. To make sure that 100% of the value can be allocated to outbound HTLCs from the LSP's perspective as the comment describes, the user needs to set their max_inbound to 100%.

So seems to me the intention of the code did not match the comment ?

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@jkczyz jkczyz Apr 28, 2026

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Hmm... yeah it does seem that way.

}

if let Some(role) = async_payments_role {
Expand Down Expand Up @@ -1695,16 +1690,16 @@ fn build_with_store_internal(
user_config,
channel_monitor_references,
);
let (_hash, channel_manager) =
<(BlockHash, ChannelManager)>::read(&mut &*reader, read_args).map_err(|e| {
let (_best_block, channel_manager) =
<(BlockLocator, ChannelManager)>::read(&mut &*reader, read_args).map_err(|e| {
log_error!(logger, "Failed to read channel manager from store: {}", e);
BuildError::ReadFailed
})?;
channel_manager
} else {
// We're starting a fresh node.
let best_block =
chain_tip_opt.unwrap_or_else(|| BestBlock::from_network(config.network));
chain_tip_opt.unwrap_or_else(|| BlockLocator::from_network(config.network));

let chain_params = ChainParameters { network: config.network.into(), best_block };
channelmanager::ChannelManager::new(
Expand Down
77 changes: 14 additions & 63 deletions src/chain/bitcoind.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@
// http://opensource.org/licenses/MIT>, at your option. You may not use this file except in
// accordance with one or both of these licenses.

use std::collections::{HashMap, VecDeque};
use std::collections::HashMap;
use std::fmt;
use std::future::Future;
use std::sync::atomic::{AtomicU64, Ordering};
Expand All @@ -16,7 +16,7 @@ use base64::prelude::BASE64_STANDARD;
use base64::Engine;
use bitcoin::{BlockHash, FeeRate, Network, OutPoint, Transaction, Txid};
use lightning::chain::chaininterface::ConfirmationTarget as LdkConfirmationTarget;
use lightning::chain::{BestBlock, Listen};
use lightning::chain::{BestBlock as BlockLocator, Listen};
use lightning::util::ser::Writeable;
use lightning_block_sync::gossip::UtxoSource;
use lightning_block_sync::http::{HttpClientError, JsonResponse};
Expand All @@ -25,7 +25,7 @@ use lightning_block_sync::poll::{ChainPoller, ChainTip, ValidatedBlockHeader};
use lightning_block_sync::rest::RestClient;
use lightning_block_sync::rpc::{RpcClient, RpcClientError};
use lightning_block_sync::{
BlockData, BlockHeaderData, BlockSource, BlockSourceError, BlockSourceErrorKind, Cache,
BlockData, BlockHeaderData, BlockSource, BlockSourceError, BlockSourceErrorKind, HeaderCache,
SpvClient,
};
use serde::Serialize;
Expand All @@ -49,7 +49,6 @@ const CHAIN_POLLING_TIMEOUT_SECS: u64 = 10;

pub(super) struct BitcoindChainSource {
api_client: Arc<BitcoindClient>,
header_cache: tokio::sync::Mutex<BoundedHeaderCache>,
latest_chain_tip: RwLock<Option<ValidatedBlockHeader>>,
wallet_polling_status: Mutex<WalletSyncStatus>,
fee_estimator: Arc<OnchainFeeEstimator>,
Expand All @@ -72,12 +71,10 @@ impl BitcoindChainSource {
rpc_password.clone(),
));

let header_cache = tokio::sync::Mutex::new(BoundedHeaderCache::new());
let latest_chain_tip = RwLock::new(None);
let wallet_polling_status = Mutex::new(WalletSyncStatus::Completed);
Self {
api_client,
header_cache,
latest_chain_tip,
wallet_polling_status,
fee_estimator,
Expand All @@ -103,13 +100,11 @@ impl BitcoindChainSource {
rpc_password,
));

let header_cache = tokio::sync::Mutex::new(BoundedHeaderCache::new());
let latest_chain_tip = RwLock::new(None);
let wallet_polling_status = Mutex::new(WalletSyncStatus::Completed);

Self {
api_client,
header_cache,
latest_chain_tip,
wallet_polling_status,
fee_estimator,
Expand Down Expand Up @@ -153,46 +148,43 @@ impl BitcoindChainSource {
return;
}

let channel_manager_best_block_hash = channel_manager.current_best_block().block_hash;
let sweeper_best_block_hash = output_sweeper.current_best_block().block_hash;
let onchain_wallet_best_block_hash = onchain_wallet.current_best_block().block_hash;
let onchain_wallet_best_block = onchain_wallet.current_best_block();
let channel_manager_best_block = channel_manager.current_best_block();
let sweeper_best_block = output_sweeper.current_best_block();

let mut chain_listeners = vec![
(onchain_wallet_best_block_hash, &*onchain_wallet as &(dyn Listen + Send + Sync)),
(channel_manager_best_block_hash, &*channel_manager as &(dyn Listen + Send + Sync)),
(sweeper_best_block_hash, &*output_sweeper as &(dyn Listen + Send + Sync)),
(onchain_wallet_best_block, &*onchain_wallet as &(dyn Listen + Send + Sync)),
(channel_manager_best_block, &*channel_manager as &(dyn Listen + Send + Sync)),
(sweeper_best_block, &*output_sweeper as &(dyn Listen + Send + Sync)),
];

// TODO: Eventually we might want to see if we can synchronize `ChannelMonitor`s
// before giving them to `ChainMonitor` it the first place. However, this isn't
// trivial as we load them on initialization (in the `Builder`) and only gain
// network access during `start`. For now, we just make sure we get the worst known
// block hash and sychronize them via `ChainMonitor`.
if let Some(worst_channel_monitor_block_hash) = chain_monitor
if let Some(worst_channel_monitor_best_block) = chain_monitor
.list_monitors()
.iter()
.flat_map(|channel_id| chain_monitor.get_monitor(*channel_id))
.map(|m| m.current_best_block())
.min_by_key(|b| b.height)
.map(|b| b.block_hash)
{
chain_listeners.push((
worst_channel_monitor_block_hash,
worst_channel_monitor_best_block,
&*chain_monitor as &(dyn Listen + Send + Sync),
));
}

let mut locked_header_cache = self.header_cache.lock().await;
let now = SystemTime::now();
match synchronize_listeners(
self.api_client.as_ref(),
self.config.network,
&mut *locked_header_cache,
chain_listeners.clone(),
)
.await
{
Ok(chain_tip) => {
Ok((_header_cache, chain_tip)) => {
{
let elapsed_ms = now.elapsed().map(|d| d.as_millis()).unwrap_or(0);
log_info!(
Expand Down Expand Up @@ -333,7 +325,7 @@ impl BitcoindChainSource {
}
}

pub(super) async fn poll_best_block(&self) -> Result<BestBlock, Error> {
pub(super) async fn poll_best_block(&self) -> Result<BlockLocator, Error> {
self.poll_chain_tip().await.map(|tip| tip.to_best_block())
}

Expand Down Expand Up @@ -400,7 +392,6 @@ impl BitcoindChainSource {
let chain_tip =
if let Some(tip) = latest_chain_tip_opt { tip } else { self.poll_chain_tip().await? };

let mut locked_header_cache = self.header_cache.lock().await;
let chain_poller = ChainPoller::new(Arc::clone(&self.api_client), self.config.network);
let chain_listener = ChainListener {
onchain_wallet: Arc::clone(&onchain_wallet),
Expand All @@ -409,7 +400,7 @@ impl BitcoindChainSource {
output_sweeper,
};
let mut spv_client =
SpvClient::new(chain_tip, chain_poller, &mut *locked_header_cache, &chain_listener);
SpvClient::new(chain_tip, chain_poller, HeaderCache::new(), &chain_listener);

let now = SystemTime::now();
match spv_client.poll_best_tip().await {
Expand Down Expand Up @@ -1350,46 +1341,6 @@ pub(crate) enum FeeRateEstimationMode {
Conservative,
}

const MAX_HEADER_CACHE_ENTRIES: usize = 100;

pub(crate) struct BoundedHeaderCache {
header_map: HashMap<BlockHash, ValidatedBlockHeader>,
recently_seen: VecDeque<BlockHash>,
}

impl BoundedHeaderCache {
pub(crate) fn new() -> Self {
let header_map = HashMap::new();
let recently_seen = VecDeque::new();
Self { header_map, recently_seen }
}
}

impl Cache for BoundedHeaderCache {
fn look_up(&self, block_hash: &BlockHash) -> Option<&ValidatedBlockHeader> {
self.header_map.get(block_hash)
}

fn block_connected(&mut self, block_hash: BlockHash, block_header: ValidatedBlockHeader) {
self.recently_seen.push_back(block_hash);
self.header_map.insert(block_hash, block_header);

if self.header_map.len() >= MAX_HEADER_CACHE_ENTRIES {
// Keep dropping old entries until we've actually removed a header entry.
while let Some(oldest_entry) = self.recently_seen.pop_front() {
if self.header_map.remove(&oldest_entry).is_some() {
break;
}
}
}
}

fn block_disconnected(&mut self, block_hash: &BlockHash) -> Option<ValidatedBlockHeader> {
self.recently_seen.retain(|e| e != block_hash);
self.header_map.remove(block_hash)
}
}

pub(crate) struct ChainListener {
pub(crate) onchain_wallet: Arc<Wallet>,
pub(crate) channel_manager: Arc<ChannelManager>,
Expand Down
10 changes: 5 additions & 5 deletions src/chain/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ use std::sync::{Arc, Mutex, RwLock};
use std::time::Duration;

use bitcoin::{Script, Txid};
use lightning::chain::{BestBlock, Filter};
use lightning::chain::{BestBlock as BlockLocator, Filter};

use crate::chain::bitcoind::{BitcoindChainSource, UtxoSourceClient};
use crate::chain::electrum::ElectrumChainSource;
Expand Down Expand Up @@ -101,7 +101,7 @@ impl ChainSource {
fee_estimator: Arc<OnchainFeeEstimator>, tx_broadcaster: Arc<Broadcaster>,
kv_store: Arc<DynStore>, config: Arc<Config>, logger: Arc<Logger>,
node_metrics: Arc<RwLock<NodeMetrics>>,
) -> Result<(Self, Option<BestBlock>), ()> {
) -> Result<(Self, Option<BlockLocator>), ()> {
let esplora_chain_source = EsploraChainSource::new(
server_url,
headers,
Expand All @@ -122,7 +122,7 @@ impl ChainSource {
fee_estimator: Arc<OnchainFeeEstimator>, tx_broadcaster: Arc<Broadcaster>,
kv_store: Arc<DynStore>, config: Arc<Config>, logger: Arc<Logger>,
node_metrics: Arc<RwLock<NodeMetrics>>,
) -> (Self, Option<BestBlock>) {
) -> (Self, Option<BlockLocator>) {
let electrum_chain_source = ElectrumChainSource::new(
server_url,
sync_config,
Expand All @@ -142,7 +142,7 @@ impl ChainSource {
fee_estimator: Arc<OnchainFeeEstimator>, tx_broadcaster: Arc<Broadcaster>,
kv_store: Arc<DynStore>, config: Arc<Config>, logger: Arc<Logger>,
node_metrics: Arc<RwLock<NodeMetrics>>,
) -> (Self, Option<BestBlock>) {
) -> (Self, Option<BlockLocator>) {
let bitcoind_chain_source = BitcoindChainSource::new_rpc(
rpc_host,
rpc_port,
Expand All @@ -165,7 +165,7 @@ impl ChainSource {
fee_estimator: Arc<OnchainFeeEstimator>, tx_broadcaster: Arc<Broadcaster>,
kv_store: Arc<DynStore>, config: Arc<Config>, rest_client_config: BitcoindRestClientConfig,
logger: Arc<Logger>, node_metrics: Arc<RwLock<NodeMetrics>>,
) -> (Self, Option<BestBlock>) {
) -> (Self, Option<BlockLocator>) {
let bitcoind_chain_source = BitcoindChainSource::new_rest(
rpc_host,
rpc_port,
Expand Down
24 changes: 13 additions & 11 deletions src/event.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -26,9 +26,7 @@ use lightning::ln::channelmanager::{PaymentId, TrustedChannelFeatures};
use lightning::ln::types::ChannelId;
use lightning::routing::gossip::NodeId;
use lightning::sign::EntropySource;
use lightning::util::config::{
ChannelConfigOverrides, ChannelConfigUpdate, ChannelHandshakeConfigUpdate,
};
use lightning::util::config::{ChannelConfigOverrides, ChannelConfigUpdate};
use lightning::util::errors::APIError;
use lightning::util::persist::KVStore;
use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
Expand Down Expand Up @@ -1273,20 +1271,24 @@ where
if lsp_node_id == counterparty_node_id {
// When we're an LSPS2 client, allow claiming underpaying HTLCs as the LSP will skim off some fee. We'll
// check that they don't take too much before claiming.
//
// We also set maximum allowed inbound HTLC value in flight
// to 100%. We should eventually be able to set this on a per-channel basis, but for
// now we just bump the default for all channels.
channel_override_config = Some(ChannelConfigOverrides {
handshake_overrides: Some(ChannelHandshakeConfigUpdate {
max_inbound_htlc_value_in_flight_percent_of_channel: Some(100),
..Default::default()
}),
update_overrides: Some(ChannelConfigUpdate {
accept_underpaying_htlcs: Some(true),
..Default::default()
}),
..Default::default()
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@tankyleo tankyleo Apr 28, 2026

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nit: as elsewhere, maybe a quick debug_assert here on the 100% value ? Up to @tnull

});

// LSPS2 channels are unannounced; rely on LDK's default of 100%
// inbound HTLC value-in-flight so the LSP can forward the initial
// payment in full.
debug_assert_eq!(
self.channel_manager
.get_current_config()
.channel_handshake_config
.unannounced_channel_max_inbound_htlc_value_in_flight_percentage,
100
);
}
}
let res = if allow_0conf {
Expand Down
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