// You may not use this file except in accordance with one or both of these
// licenses.
+use crate::blinded_path::BlindedHop;
use crate::crypto::chacha20::ChaCha20;
use crate::crypto::streams::ChaChaReader;
+use crate::ln::channel::TOTAL_BITCOIN_SUPPLY_SATOSHIS;
use crate::ln::channelmanager::{HTLCSource, RecipientOnionFields};
+use crate::ln::features::{ChannelFeatures, NodeFeatures};
use crate::ln::msgs;
use crate::ln::types::{PaymentHash, PaymentPreimage};
use crate::ln::wire::Encode;
use crate::routing::gossip::NetworkUpdate;
-use crate::routing::router::{BlindedTail, Path, RouteHop};
+use crate::routing::router::{Path, RouteHop, RouteParameters};
use crate::sign::NodeSigner;
use crate::util::errors::{self, APIError};
use crate::util::logger::Logger;
path: &'a Path, total_msat: u64, recipient_onion: &'a RecipientOnionFields,
starting_htlc_offset: u32, keysend_preimage: &Option<PaymentPreimage>,
) -> Result<(Vec<msgs::OutboundOnionPayload<'a>>, u64, u32), APIError> {
- let mut cur_value_msat = 0u64;
- let mut cur_cltv = starting_htlc_offset;
- let mut last_short_channel_id = 0;
let mut res: Vec<msgs::OutboundOnionPayload> = Vec::with_capacity(
path.hops.len() + path.blinded_tail.as_ref().map_or(0, |t| t.hops.len()),
);
+ let blinded_tail_with_hop_iter = path.blinded_tail.as_ref().map(|bt| BlindedTailHopIter {
+ hops: bt.hops.iter(),
+ blinding_point: bt.blinding_point,
+ final_value_msat: bt.final_value_msat,
+ excess_final_cltv_expiry_delta: bt.excess_final_cltv_expiry_delta,
+ });
+
+ let (value_msat, cltv) = build_onion_payloads_callback(
+ path.hops.iter(),
+ blinded_tail_with_hop_iter,
+ total_msat,
+ recipient_onion,
+ starting_htlc_offset,
+ keysend_preimage,
+ |action, payload| match action {
+ PayloadCallbackAction::PushBack => res.push(payload),
+ PayloadCallbackAction::PushFront => res.insert(0, payload),
+ },
+ )?;
+ Ok((res, value_msat, cltv))
+}
- for (idx, hop) in path.hops.iter().rev().enumerate() {
+struct BlindedTailHopIter<'a, I: Iterator<Item = &'a BlindedHop>> {
+ hops: I,
+ blinding_point: PublicKey,
+ final_value_msat: u64,
+ excess_final_cltv_expiry_delta: u32,
+}
+enum PayloadCallbackAction {
+ PushBack,
+ PushFront,
+}
+fn build_onion_payloads_callback<'a, H, B, F>(
+ hops: H, mut blinded_tail: Option<BlindedTailHopIter<'a, B>>, total_msat: u64,
+ recipient_onion: &'a RecipientOnionFields, starting_htlc_offset: u32,
+ keysend_preimage: &Option<PaymentPreimage>, mut callback: F,
+) -> Result<(u64, u32), APIError>
+where
+ H: DoubleEndedIterator<Item = &'a RouteHop>,
+ B: ExactSizeIterator<Item = &'a BlindedHop>,
+ F: FnMut(PayloadCallbackAction, msgs::OutboundOnionPayload<'a>),
+{
+ let mut cur_value_msat = 0u64;
+ let mut cur_cltv = starting_htlc_offset;
+ let mut last_short_channel_id = 0;
+
+ for (idx, hop) in hops.rev().enumerate() {
// First hop gets special values so that it can check, on receipt, that everything is
// exactly as it should be (and the next hop isn't trying to probe to find out if we're
// the intended recipient).
cur_cltv
};
if idx == 0 {
- if let Some(BlindedTail {
+ if let Some(BlindedTailHopIter {
blinding_point,
hops,
final_value_msat,
excess_final_cltv_expiry_delta,
..
- }) = &path.blinded_tail
+ }) = blinded_tail.take()
{
- let mut blinding_point = Some(*blinding_point);
- for (i, blinded_hop) in hops.iter().enumerate() {
- if i == hops.len() - 1 {
+ let mut blinding_point = Some(blinding_point);
+ let hops_len = hops.len();
+ for (i, blinded_hop) in hops.enumerate() {
+ if i == hops_len - 1 {
cur_value_msat += final_value_msat;
- res.push(msgs::OutboundOnionPayload::BlindedReceive {
- sender_intended_htlc_amt_msat: *final_value_msat,
- total_msat,
- cltv_expiry_height: cur_cltv + excess_final_cltv_expiry_delta,
- encrypted_tlvs: &blinded_hop.encrypted_payload,
- intro_node_blinding_point: blinding_point.take(),
- keysend_preimage: *keysend_preimage,
- custom_tlvs: &recipient_onion.custom_tlvs,
- });
+ callback(
+ PayloadCallbackAction::PushBack,
+ msgs::OutboundOnionPayload::BlindedReceive {
+ sender_intended_htlc_amt_msat: final_value_msat,
+ total_msat,
+ cltv_expiry_height: cur_cltv + excess_final_cltv_expiry_delta,
+ encrypted_tlvs: &blinded_hop.encrypted_payload,
+ intro_node_blinding_point: blinding_point.take(),
+ keysend_preimage: *keysend_preimage,
+ custom_tlvs: &recipient_onion.custom_tlvs,
+ },
+ );
} else {
- res.push(msgs::OutboundOnionPayload::BlindedForward {
- encrypted_tlvs: &blinded_hop.encrypted_payload,
- intro_node_blinding_point: blinding_point.take(),
- });
+ callback(
+ PayloadCallbackAction::PushBack,
+ msgs::OutboundOnionPayload::BlindedForward {
+ encrypted_tlvs: &blinded_hop.encrypted_payload,
+ intro_node_blinding_point: blinding_point.take(),
+ },
+ );
}
}
} else {
- res.push(msgs::OutboundOnionPayload::Receive {
- payment_data: recipient_onion.payment_secret.map(|payment_secret| {
- msgs::FinalOnionHopData { payment_secret, total_msat }
- }),
- payment_metadata: recipient_onion.payment_metadata.as_ref(),
- keysend_preimage: *keysend_preimage,
- custom_tlvs: &recipient_onion.custom_tlvs,
- sender_intended_htlc_amt_msat: value_msat,
- cltv_expiry_height: cltv,
- });
+ callback(
+ PayloadCallbackAction::PushBack,
+ msgs::OutboundOnionPayload::Receive {
+ payment_data: recipient_onion.payment_secret.map(|payment_secret| {
+ msgs::FinalOnionHopData { payment_secret, total_msat }
+ }),
+ payment_metadata: recipient_onion.payment_metadata.as_ref(),
+ keysend_preimage: *keysend_preimage,
+ custom_tlvs: &recipient_onion.custom_tlvs,
+ sender_intended_htlc_amt_msat: value_msat,
+ cltv_expiry_height: cltv,
+ },
+ );
}
} else {
let payload = msgs::OutboundOnionPayload::Forward {
amt_to_forward: value_msat,
outgoing_cltv_value: cltv,
};
- res.insert(0, payload);
+ callback(PayloadCallbackAction::PushFront, payload);
}
cur_value_msat += hop.fee_msat;
if cur_value_msat >= 21000000 * 100000000 * 1000 {
}
last_short_channel_id = hop.short_channel_id;
}
- Ok((res, cur_value_msat, cur_cltv))
+ Ok((cur_value_msat, cur_cltv))
+}
+
+pub(crate) const MIN_FINAL_VALUE_ESTIMATE_WITH_OVERPAY: u64 = 100_000_000;
+
+pub(crate) fn set_max_path_length(
+ route_params: &mut RouteParameters, recipient_onion: &RecipientOnionFields,
+ keysend_preimage: Option<PaymentPreimage>, best_block_height: u32,
+) -> Result<(), ()> {
+ const PAYLOAD_HMAC_LEN: usize = 32;
+ let unblinded_intermed_payload_len = msgs::OutboundOnionPayload::Forward {
+ short_channel_id: 42,
+ amt_to_forward: TOTAL_BITCOIN_SUPPLY_SATOSHIS,
+ outgoing_cltv_value: route_params.payment_params.max_total_cltv_expiry_delta,
+ }
+ .serialized_length()
+ .saturating_add(PAYLOAD_HMAC_LEN);
+
+ const OVERPAY_ESTIMATE_MULTIPLER: u64 = 3;
+ let final_value_msat_with_overpay_buffer = core::cmp::max(
+ route_params.final_value_msat.saturating_mul(OVERPAY_ESTIMATE_MULTIPLER),
+ MIN_FINAL_VALUE_ESTIMATE_WITH_OVERPAY,
+ );
+
+ let blinded_tail_opt = route_params
+ .payment_params
+ .payee
+ .blinded_route_hints()
+ .iter()
+ .map(|(_, path)| path)
+ .max_by_key(|path| path.serialized_length())
+ .map(|largest_path| BlindedTailHopIter {
+ hops: largest_path.blinded_hops.iter(),
+ blinding_point: largest_path.blinding_point,
+ final_value_msat: final_value_msat_with_overpay_buffer,
+ excess_final_cltv_expiry_delta: 0,
+ });
+
+ let unblinded_route_hop = RouteHop {
+ pubkey: PublicKey::from_slice(&[2; 33]).unwrap(),
+ node_features: NodeFeatures::empty(),
+ short_channel_id: 42,
+ channel_features: ChannelFeatures::empty(),
+ fee_msat: final_value_msat_with_overpay_buffer,
+ cltv_expiry_delta: route_params.payment_params.max_total_cltv_expiry_delta,
+ maybe_announced_channel: false,
+ };
+ let mut num_reserved_bytes: usize = 0;
+ let build_payloads_res = build_onion_payloads_callback(
+ core::iter::once(&unblinded_route_hop),
+ blinded_tail_opt,
+ final_value_msat_with_overpay_buffer,
+ &recipient_onion,
+ best_block_height,
+ &keysend_preimage,
+ |_, payload| {
+ num_reserved_bytes = num_reserved_bytes
+ .saturating_add(payload.serialized_length())
+ .saturating_add(PAYLOAD_HMAC_LEN);
+ },
+ );
+ debug_assert!(build_payloads_res.is_ok());
+
+ let max_path_length = 1300usize
+ .checked_sub(num_reserved_bytes)
+ .map(|p| p / unblinded_intermed_payload_len)
+ .and_then(|l| u8::try_from(l.saturating_add(1)).ok())
+ .ok_or(())?;
+
+ route_params.payment_params.max_path_length =
+ core::cmp::min(max_path_length, route_params.payment_params.max_path_length);
+ Ok(())
}
/// Length of the onion data packet. Before TLV-based onions this was 20 65-byte hops, though now
/// `cur_block_height` should be set to the best known block height + 1.
pub fn create_payment_onion<T: secp256k1::Signing>(
secp_ctx: &Secp256k1<T>, path: &Path, session_priv: &SecretKey, total_msat: u64,
- recipient_onion: RecipientOnionFields, cur_block_height: u32, payment_hash: &PaymentHash,
+ recipient_onion: &RecipientOnionFields, cur_block_height: u32, payment_hash: &PaymentHash,
keysend_preimage: &Option<PaymentPreimage>, prng_seed: [u8; 32],
) -> Result<(msgs::OnionPacket, u64, u32), APIError> {
let onion_keys = construct_onion_keys(&secp_ctx, &path, &session_priv).map_err(|_| {
let (onion_payloads, htlc_msat, htlc_cltv) = build_onion_payloads(
&path,
total_msat,
- &recipient_onion,
+ recipient_onion,
cur_block_height,
keysend_preimage,
)?;