X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;ds=sidebyside;f=lightning%2Fsrc%2Fln%2Fonion_utils.rs;fp=lightning%2Fsrc%2Fln%2Fonion_utils.rs;h=9a207c9e52d1dd1805592bf039dd9ff84387a6b4;hb=37bf61c49bb8d0f3d5a9bc8de390e97f6b2ac0c1;hp=0abcb7de26df55468001afff373a0d5281e81e59;hpb=511d7e3f5fe5900178cc43320d21089826681581;p=rust-lightning diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs index 0abcb7de..9a207c9e 100644 --- a/lightning/src/ln/onion_utils.rs +++ b/lightning/src/ln/onion_utils.rs @@ -7,14 +7,17 @@ // 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; @@ -174,18 +177,60 @@ pub(super) fn construct_onion_keys( } /// returns the hop data, as well as the first-hop value_msat and CLTV value we should send. -pub(super) fn build_onion_payloads( - path: &Path, total_msat: u64, mut recipient_onion: RecipientOnionFields, +pub(super) fn build_onion_payloads<'a>( + path: &'a Path, total_msat: u64, recipient_onion: &'a RecipientOnionFields, starting_htlc_offset: u32, keysend_preimage: &Option, -) -> Result<(Vec, u64, u32), APIError> { - let mut cur_value_msat = 0u64; - let mut cur_cltv = starting_htlc_offset; - let mut last_short_channel_id = 0; +) -> Result<(Vec>, u64, u32), APIError> { let mut res: Vec = 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> { + 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>, total_msat: u64, + recipient_onion: &'a RecipientOnionFields, starting_htlc_offset: u32, + keysend_preimage: &Option, mut callback: F, +) -> Result<(u64, u32), APIError> +where + H: DoubleEndedIterator, + B: ExactSizeIterator, + 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). @@ -196,47 +241,55 @@ pub(super) fn build_onion_payloads( 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.clone(), - intro_node_blinding_point: blinding_point.take(), - keysend_preimage: *keysend_preimage, - custom_tlvs: recipient_onion.custom_tlvs.clone(), - }); + 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.clone(), - 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: if let Some(secret) = recipient_onion.payment_secret.take() { - Some(msgs::FinalOnionHopData { payment_secret: secret, total_msat }) - } else { - None + 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, }, - payment_metadata: recipient_onion.payment_metadata.take(), - keysend_preimage: *keysend_preimage, - custom_tlvs: recipient_onion.custom_tlvs.clone(), - sender_intended_htlc_amt_msat: value_msat, - cltv_expiry_height: cltv, - }); + ); } } else { let payload = msgs::OutboundOnionPayload::Forward { @@ -244,7 +297,7 @@ pub(super) fn build_onion_payloads( 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 { @@ -256,7 +309,78 @@ pub(super) fn build_onion_payloads( } 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, 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 @@ -1124,7 +1248,7 @@ where /// `cur_block_height` should be set to the best known block height + 1. pub fn create_payment_onion( secp_ctx: &Secp256k1, 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, prng_seed: [u8; 32], ) -> Result<(msgs::OnionPacket, u64, u32), APIError> { let onion_keys = construct_onion_keys(&secp_ctx, &path, &session_priv).map_err(|_| {