X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fonion_utils.rs;h=fab73cf73ec4320cfbe499a29d947ce168b5ad41;hb=b8cdde8af64189fd1567cbc85cfae26c610af969;hp=2aba2c75748ed4ad74813206b7e302964d594075;hpb=bcdb67e5602c3c0d6a94893ea1681456061f4474;p=rust-lightning diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs index 2aba2c75..fab73cf7 100644 --- a/lightning/src/ln/onion_utils.rs +++ b/lightning/src/ln/onion_utils.rs @@ -10,12 +10,13 @@ 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::{Path, RouteHop}; +use crate::routing::router::{Path, RouteHop, RouteParameters}; use crate::sign::NodeSigner; use crate::util::errors::{self, APIError}; use crate::util::logger::Logger; @@ -310,6 +311,77 @@ where 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 /// the hops can be of variable length. pub(crate) const ONION_DATA_LEN: usize = 20 * 65; @@ -733,106 +805,16 @@ where { let update_len = u16::from_be_bytes(update_len_slice.try_into().expect("len is 2")) as usize; - if let Some(mut update_slice) = err_packet + if err_packet .failuremsg .get(debug_field_size + 4..debug_field_size + 4 + update_len) + .is_some() { - // Historically, the BOLTs were unclear if the message type - // bytes should be included here or not. The BOLTs have now - // been updated to indicate that they *are* included, but many - // nodes still send messages without the type bytes, so we - // support both here. - // TODO: Switch to hard require the type prefix, as the current - // permissiveness introduces the (although small) possibility - // that we fail to decode legitimate channel updates that - // happen to start with ChannelUpdate::TYPE, i.e., [0x01, 0x02]. - if update_slice.len() > 2 - && update_slice[0..2] == msgs::ChannelUpdate::TYPE.to_be_bytes() - { - update_slice = &update_slice[2..]; - } else { - log_trace!(logger, "Failure provided features a channel update without type prefix. Deprecated, but allowing for now."); - } - let update_opt = msgs::ChannelUpdate::read(&mut Cursor::new(&update_slice)); - if update_opt.is_ok() || update_slice.is_empty() { - // if channel_update should NOT have caused the failure: - // MAY treat the channel_update as invalid. - let is_chan_update_invalid = match error_code & 0xff { - 7 => false, - 11 => { - update_opt.is_ok() - && amt_to_forward - > update_opt.as_ref().unwrap().contents.htlc_minimum_msat - }, - 12 => { - update_opt.is_ok() - && amt_to_forward - .checked_mul( - update_opt - .as_ref() - .unwrap() - .contents - .fee_proportional_millionths as u64, - ) - .map(|prop_fee| prop_fee / 1_000_000) - .and_then(|prop_fee| { - prop_fee.checked_add( - update_opt.as_ref().unwrap().contents.fee_base_msat - as u64, - ) - }) - .map(|fee_msats| route_hop.fee_msat >= fee_msats) - .unwrap_or(false) - }, - 13 => { - update_opt.is_ok() - && route_hop.cltv_expiry_delta as u16 - >= update_opt.as_ref().unwrap().contents.cltv_expiry_delta - }, - 14 => false, // expiry_too_soon; always valid? - 20 => update_opt.as_ref().unwrap().contents.flags & 2 == 0, - _ => false, // unknown error code; take channel_update as valid - }; - if is_chan_update_invalid { - // This probably indicates the node which forwarded - // to the node in question corrupted something. - network_update = Some(NetworkUpdate::ChannelFailure { - short_channel_id: route_hop.short_channel_id, - is_permanent: true, - }); - } else { - if let Ok(chan_update) = update_opt { - // Make sure the ChannelUpdate contains the expected - // short channel id. - if failing_route_hop.short_channel_id - == chan_update.contents.short_channel_id - { - short_channel_id = Some(failing_route_hop.short_channel_id); - } else { - log_info!(logger, "Node provided a channel_update for which it was not authoritative, ignoring."); - } - network_update = - Some(NetworkUpdate::ChannelUpdateMessage { msg: chan_update }) - } else { - // The node in question intentionally encoded a 0-length channel update. This is - // likely due to https://github.com/ElementsProject/lightning/issues/6200. - short_channel_id = Some(failing_route_hop.short_channel_id); - network_update = Some(NetworkUpdate::ChannelFailure { - short_channel_id: failing_route_hop.short_channel_id, - is_permanent: false, - }); - } - }; - } else { - // If the channel_update had a non-zero length (i.e. was - // present) but we couldn't read it, treat it as a total - // node failure. - log_info!( - logger, - "Failed to read a channel_update of len {} in an onion", - update_slice.len() - ); - } + network_update = Some(NetworkUpdate::ChannelFailure { + short_channel_id: failing_route_hop.short_channel_id, + is_permanent: false, + }); + short_channel_id = Some(failing_route_hop.short_channel_id); } } if network_update.is_none() {