X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannelmanager.rs;h=44ad0a16037adda6b2775e0434b0539e6d0de760;hb=555cb4024fde76ed2bea0466289ae45c8904b395;hp=d788356d63c23fe312452a6560e0597c69cf5e58;hpb=3e88b72c50bf52626ded205735181a21ef273b2a;p=rust-lightning diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index d788356d..44ad0a16 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -92,8 +92,8 @@ use core::ops::Deref; pub(super) enum PendingHTLCRouting { Forward { onion_packet: msgs::OnionPacket, - /// The SCID from the onion that we should forward to. This could be a "real" SCID, an - /// outbound SCID alias, or a phantom node SCID. + /// The SCID from the onion that we should forward to. This could be a real SCID or a fake one + /// generated using `get_fake_scid` from the scid_utils::fake_scid module. short_channel_id: u64, // This should be NonZero eventually when we bump MSRV }, Receive { @@ -207,6 +207,24 @@ impl Readable for PaymentId { Ok(PaymentId(buf)) } } + +/// An identifier used to uniquely identify an intercepted HTLC to LDK. +/// (C-not exported) as we just use [u8; 32] directly +#[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)] +pub struct InterceptId(pub [u8; 32]); + +impl Writeable for InterceptId { + fn write(&self, w: &mut W) -> Result<(), io::Error> { + self.0.write(w) + } +} + +impl Readable for InterceptId { + fn read(r: &mut R) -> Result { + let buf: [u8; 32] = Readable::read(r)?; + Ok(InterceptId(buf)) + } +} /// Tracks the inbound corresponding to an outbound HTLC #[allow(clippy::derive_hash_xor_eq)] // Our Hash is faithful to the data, we just don't have SecretKey::hash #[derive(Clone, PartialEq, Eq)] @@ -269,6 +287,16 @@ pub(super) enum HTLCFailReason { } } +impl HTLCFailReason { + pub(super) fn reason(failure_code: u16, data: Vec) -> Self { + Self::Reason { failure_code, data } + } + + pub(super) fn from_failure_code(failure_code: u16) -> Self { + Self::Reason { failure_code, data: Vec::new() } + } +} + struct ReceiveError { err_code: u16, err_data: Vec, @@ -666,6 +694,8 @@ pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L> = ChannelManage // `total_consistency_lock` // | // |__`forward_htlcs` +// | | +// | |__`pending_intercepted_htlcs` // | // |__`pending_inbound_payments` // | | @@ -751,6 +781,11 @@ pub struct ChannelManager pub(super) forward_htlcs: Mutex>>, #[cfg(not(test))] forward_htlcs: Mutex>>, + /// Storage for HTLCs that have been intercepted and bubbled up to the user. We hold them here + /// until the user tells us what we should do with them. + /// + /// See `ChannelManager` struct-level documentation for lock order requirements. + pending_intercepted_htlcs: Mutex>, /// Map from payment hash to the payment data and any HTLCs which are to us and can be /// failed/claimed by the user. @@ -1566,6 +1601,7 @@ impl ChannelManager ChannelManager ChannelManager ChannelManager { // unknown_next_peer // Note that this is likely a timing oracle for detecting whether an scid is a - // phantom. - if fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, *short_channel_id, &self.genesis_hash) { + // phantom or an intercept. + if (self.default_configuration.accept_intercept_htlcs && + fake_scid::is_valid_intercept(&self.fake_scid_rand_bytes, *short_channel_id, &self.genesis_hash)) || + fake_scid::is_valid_phantom(&self.fake_scid_rand_bytes, *short_channel_id, &self.genesis_hash) + { None } else { break Some(("Don't have available channel for forwarding as requested.", 0x4000 | 10, None)); @@ -3023,6 +3062,102 @@ impl ChannelManager Result<(), APIError> { + let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier); + + let next_hop_scid = match self.channel_state.lock().unwrap().by_id.get(next_hop_channel_id) { + Some(chan) => { + if !chan.is_usable() { + return Err(APIError::APIMisuseError { + err: format!("Channel with id {:?} not fully established", next_hop_channel_id) + }) + } + chan.get_short_channel_id().unwrap_or(chan.outbound_scid_alias()) + }, + None => return Err(APIError::APIMisuseError { + err: format!("Channel with id {:?} not found", next_hop_channel_id) + }) + }; + + let payment = self.pending_intercepted_htlcs.lock().unwrap().remove(&intercept_id) + .ok_or_else(|| APIError::APIMisuseError { + err: format!("Payment with intercept id {:?} not found", intercept_id.0) + })?; + + let routing = match payment.forward_info.routing { + PendingHTLCRouting::Forward { onion_packet, .. } => { + PendingHTLCRouting::Forward { onion_packet, short_channel_id: next_hop_scid } + }, + _ => unreachable!() // Only `PendingHTLCRouting::Forward`s are intercepted + }; + let pending_htlc_info = PendingHTLCInfo { + outgoing_amt_msat: amt_to_forward_msat, routing, ..payment.forward_info + }; + + let mut per_source_pending_forward = [( + payment.prev_short_channel_id, + payment.prev_funding_outpoint, + payment.prev_user_channel_id, + vec![(pending_htlc_info, payment.prev_htlc_id)] + )]; + self.forward_htlcs(&mut per_source_pending_forward); + Ok(()) + } + + /// Fails the intercepted HTLC indicated by intercept_id. Should only be called in response to + /// an [`HTLCIntercepted`] event. See [`ChannelManager::forward_intercepted_htlc`]. + /// + /// Errors if the event was not handled in time, in which case the HTLC was automatically failed + /// backwards. + /// + /// [`HTLCIntercepted`]: events::Event::HTLCIntercepted + pub fn fail_intercepted_htlc(&self, intercept_id: InterceptId) -> Result<(), APIError> { + let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier); + + let payment = self.pending_intercepted_htlcs.lock().unwrap().remove(&intercept_id) + .ok_or_else(|| APIError::APIMisuseError { + err: format!("Payment with InterceptId {:?} not found", intercept_id) + })?; + + if let PendingHTLCRouting::Forward { short_channel_id, .. } = payment.forward_info.routing { + let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData { + short_channel_id: payment.prev_short_channel_id, + outpoint: payment.prev_funding_outpoint, + htlc_id: payment.prev_htlc_id, + incoming_packet_shared_secret: payment.forward_info.incoming_shared_secret, + phantom_shared_secret: None, + }); + + let failure_reason = HTLCFailReason::from_failure_code(0x4000 | 10); + let destination = HTLCDestination::UnknownNextHop { requested_forward_scid: short_channel_id }; + self.fail_htlc_backwards_internal(htlc_source, &payment.forward_info.payment_hash, failure_reason, destination); + } else { unreachable!() } // Only `PendingHTLCRouting::Forward`s are intercepted + + Ok(()) + } + /// Processes HTLCs which are pending waiting on random forward delay. /// /// Should only really ever be called in response to a PendingHTLCsForwardable event. @@ -3070,7 +3205,7 @@ impl ChannelManager ChannelManager ChannelManager ChannelManager ChannelManager ChannelManager ChannelManager ChannelManager ChannelManager return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id)) @@ -5067,28 +5202,82 @@ impl ChannelManager)]) { for &mut (prev_short_channel_id, prev_funding_outpoint, prev_user_channel_id, ref mut pending_forwards) in per_source_pending_forwards { let mut forward_event = None; + let mut new_intercept_events = Vec::new(); + let mut failed_intercept_forwards = Vec::new(); if !pending_forwards.is_empty() { - let mut forward_htlcs = self.forward_htlcs.lock().unwrap(); - if forward_htlcs.is_empty() { - forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS)) - } for (forward_info, prev_htlc_id) in pending_forwards.drain(..) { - match forward_htlcs.entry(match forward_info.routing { - PendingHTLCRouting::Forward { short_channel_id, .. } => short_channel_id, - PendingHTLCRouting::Receive { .. } => 0, - PendingHTLCRouting::ReceiveKeysend { .. } => 0, - }) { + let scid = match forward_info.routing { + PendingHTLCRouting::Forward { short_channel_id, .. } => short_channel_id, + PendingHTLCRouting::Receive { .. } => 0, + PendingHTLCRouting::ReceiveKeysend { .. } => 0, + }; + // Pull this now to avoid introducing a lock order with `forward_htlcs`. + let is_our_scid = self.short_to_chan_info.read().unwrap().contains_key(&scid); + + let mut forward_htlcs = self.forward_htlcs.lock().unwrap(); + let forward_htlcs_empty = forward_htlcs.is_empty(); + match forward_htlcs.entry(scid) { hash_map::Entry::Occupied(mut entry) => { entry.get_mut().push(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo { prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info })); }, hash_map::Entry::Vacant(entry) => { - entry.insert(vec!(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo { - prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info }))); + if !is_our_scid && forward_info.incoming_amt_msat.is_some() && + fake_scid::is_valid_intercept(&self.fake_scid_rand_bytes, scid, &self.genesis_hash) + { + let intercept_id = InterceptId(Sha256::hash(&forward_info.incoming_shared_secret).into_inner()); + let mut pending_intercepts = self.pending_intercepted_htlcs.lock().unwrap(); + match pending_intercepts.entry(intercept_id) { + hash_map::Entry::Vacant(entry) => { + new_intercept_events.push(events::Event::HTLCIntercepted { + requested_next_hop_scid: scid, + payment_hash: forward_info.payment_hash, + inbound_amount_msat: forward_info.incoming_amt_msat.unwrap(), + expected_outbound_amount_msat: forward_info.outgoing_amt_msat, + intercept_id + }); + entry.insert(PendingAddHTLCInfo { + prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info }); + }, + hash_map::Entry::Occupied(_) => { + log_info!(self.logger, "Failed to forward incoming HTLC: detected duplicate intercepted payment over short channel id {}", scid); + let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData { + short_channel_id: prev_short_channel_id, + outpoint: prev_funding_outpoint, + htlc_id: prev_htlc_id, + incoming_packet_shared_secret: forward_info.incoming_shared_secret, + phantom_shared_secret: None, + }); + + failed_intercept_forwards.push((htlc_source, forward_info.payment_hash, + HTLCFailReason::from_failure_code(0x4000 | 10), + HTLCDestination::InvalidForward { requested_forward_scid: scid }, + )); + } + } + } else { + // We don't want to generate a PendingHTLCsForwardable event if only intercepted + // payments are being processed. + if forward_htlcs_empty { + forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS)); + } + entry.insert(vec!(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo { + prev_short_channel_id, prev_funding_outpoint, prev_htlc_id, prev_user_channel_id, forward_info }))); + } } } } } + + for (htlc_source, payment_hash, failure_reason, destination) in failed_intercept_forwards.drain(..) { + self.fail_htlc_backwards_internal(htlc_source, &payment_hash, failure_reason, destination); + } + + if !new_intercept_events.is_empty() { + let mut events = self.pending_events.lock().unwrap(); + events.append(&mut new_intercept_events); + } + match forward_event { Some(time) => { let mut pending_events = self.pending_events.lock().unwrap(); @@ -5316,7 +5505,7 @@ impl ChannelManager ChannelManager u64 { + let best_block_height = self.best_block.read().unwrap().height(); + let short_to_chan_info = self.short_to_chan_info.read().unwrap(); + loop { + let scid_candidate = fake_scid::Namespace::Intercept.get_fake_scid(best_block_height, &self.genesis_hash, &self.fake_scid_rand_bytes, &self.keys_manager); + // Ensure the generated scid doesn't conflict with a real channel. + if short_to_chan_info.contains_key(&scid_candidate) { continue } + return scid_candidate + } + } + /// Gets inflight HTLC information by processing pending outbound payments that are in /// our channels. May be used during pathfinding to account for in-use channel liquidity. pub fn compute_inflight_htlcs(&self) -> InFlightHtlcs { @@ -5985,9 +6191,8 @@ where if let Ok((channel_ready_opt, mut timed_out_pending_htlcs, announcement_sigs)) = res { for (source, payment_hash) in timed_out_pending_htlcs.drain(..) { let (failure_code, data) = self.get_htlc_inbound_temp_fail_err_and_data(0x1000|14 /* expiry_too_soon */, &channel); - timed_out_htlcs.push((source, payment_hash, HTLCFailReason::Reason { - failure_code, data, - }, HTLCDestination::NextHopChannel { node_id: Some(channel.get_counterparty_node_id()), channel_id: channel.channel_id() })); + timed_out_htlcs.push((source, payment_hash, HTLCFailReason::reason(failure_code, data), + HTLCDestination::NextHopChannel { node_id: Some(channel.get_counterparty_node_id()), channel_id: channel.channel_id() })); } if let Some(channel_ready) = channel_ready_opt { send_channel_ready!(self, pending_msg_events, channel, channel_ready); @@ -6074,15 +6279,37 @@ where let mut htlc_msat_height_data = byte_utils::be64_to_array(htlc.value).to_vec(); htlc_msat_height_data.extend_from_slice(&byte_utils::be32_to_array(height)); - timed_out_htlcs.push((HTLCSource::PreviousHopData(htlc.prev_hop.clone()), payment_hash.clone(), HTLCFailReason::Reason { - failure_code: 0x4000 | 15, - data: htlc_msat_height_data - }, HTLCDestination::FailedPayment { payment_hash: payment_hash.clone() })); + timed_out_htlcs.push((HTLCSource::PreviousHopData(htlc.prev_hop.clone()), payment_hash.clone(), + HTLCFailReason::reason(0x4000 | 15, htlc_msat_height_data), + HTLCDestination::FailedPayment { payment_hash: payment_hash.clone() })); false } else { true } }); !htlcs.is_empty() // Only retain this entry if htlcs has at least one entry. }); + + let mut intercepted_htlcs = self.pending_intercepted_htlcs.lock().unwrap(); + intercepted_htlcs.retain(|_, htlc| { + if height >= htlc.forward_info.outgoing_cltv_value - HTLC_FAIL_BACK_BUFFER { + let prev_hop_data = HTLCSource::PreviousHopData(HTLCPreviousHopData { + short_channel_id: htlc.prev_short_channel_id, + htlc_id: htlc.prev_htlc_id, + incoming_packet_shared_secret: htlc.forward_info.incoming_shared_secret, + phantom_shared_secret: None, + outpoint: htlc.prev_funding_outpoint, + }); + + let requested_forward_scid /* intercept scid */ = match htlc.forward_info.routing { + PendingHTLCRouting::Forward { short_channel_id, .. } => short_channel_id, + _ => unreachable!(), + }; + timed_out_htlcs.push((prev_hop_data, htlc.forward_info.payment_hash, + HTLCFailReason::from_failure_code(0x2000 | 2), + HTLCDestination::InvalidForward { requested_forward_scid })); + log_trace!(self.logger, "Timing out intercepted HTLC with requested forward scid {}", requested_forward_scid); + false + } else { true } + }); } self.handle_init_event_channel_failures(failed_channels); @@ -6991,8 +7218,15 @@ impl Writeable for ChannelMana _ => {}, } } + + let mut pending_intercepted_htlcs = None; + let our_pending_intercepts = self.pending_intercepted_htlcs.lock().unwrap(); + if our_pending_intercepts.len() != 0 { + pending_intercepted_htlcs = Some(our_pending_intercepts); + } write_tlv_fields!(writer, { (1, pending_outbound_payments_no_retry, required), + (2, pending_intercepted_htlcs, option), (3, pending_outbound_payments, required), (5, self.our_network_pubkey, required), (7, self.fake_scid_rand_bytes, required), @@ -7306,12 +7540,14 @@ impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> // pending_outbound_payments_no_retry is for compatibility with 0.0.101 clients. let mut pending_outbound_payments_no_retry: Option>> = None; let mut pending_outbound_payments = None; + let mut pending_intercepted_htlcs: Option> = Some(HashMap::new()); let mut received_network_pubkey: Option = None; let mut fake_scid_rand_bytes: Option<[u8; 32]> = None; let mut probing_cookie_secret: Option<[u8; 32]> = None; let mut claimable_htlc_purposes = None; read_tlv_fields!(reader, { (1, pending_outbound_payments_no_retry, option), + (2, pending_intercepted_htlcs, option), (3, pending_outbound_payments, option), (5, received_network_pubkey, option), (7, fake_scid_rand_bytes, option), @@ -7534,6 +7770,7 @@ impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> inbound_payment_key: expanded_inbound_key, pending_inbound_payments: Mutex::new(pending_inbound_payments), pending_outbound_payments: Mutex::new(pending_outbound_payments.unwrap()), + pending_intercepted_htlcs: Mutex::new(pending_intercepted_htlcs.unwrap()), forward_htlcs: Mutex::new(forward_htlcs), claimable_htlcs: Mutex::new(claimable_htlcs), @@ -7565,7 +7802,7 @@ impl<'a, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> for htlc_source in failed_htlcs.drain(..) { let (source, payment_hash, counterparty_node_id, channel_id) = htlc_source; let receiver = HTLCDestination::NextHopChannel { node_id: Some(counterparty_node_id), channel_id }; - channel_manager.fail_htlc_backwards_internal(source, &payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() }, receiver); + channel_manager.fail_htlc_backwards_internal(source, &payment_hash, HTLCFailReason::from_failure_code(0x4000 | 8), receiver); } //TODO: Broadcast channel update for closed channels, but only after we've made a