From da5d707f496d61ec731828e29876660402236b36 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Tue, 11 Sep 2018 14:20:40 -0400 Subject: [PATCH] Allow duplicate-payment_hash HTLCs for HTLC forwards This is required by BOLT 2 to ensure that no attacker can simply relay every public node a duplicate-payment_hash HTLC for each HTLC it receives to deduce where an HTLC came from. Note that this makes the claim logic much less incentive-compatible as we will not claim all available HTLCs with the same payment_hash even if we know the preimage! This is OK because, most likely, any attackers trying to map the network will use small-value payments and, hopefully, we will move away from constant hashes across an entire payment at some point in the near future. This further simplifies the payment transition state a bit, so hopefully at least we got some readability out of all of this --- fuzz/fuzz_targets/channel_target.rs | 4 +- src/ln/channel.rs | 151 ++++----- src/ln/channelmanager.rs | 478 ++++++++++++---------------- 3 files changed, 284 insertions(+), 349 deletions(-) diff --git a/fuzz/fuzz_targets/channel_target.rs b/fuzz/fuzz_targets/channel_target.rs index 7b3b7df1c..f6e88417c 100644 --- a/fuzz/fuzz_targets/channel_target.rs +++ b/fuzz/fuzz_targets/channel_target.rs @@ -8,7 +8,7 @@ use bitcoin::util::hash::Sha256dHash; use bitcoin::network::serialize::{serialize, BitcoinHash}; use lightning::ln::channel::{Channel, ChannelKeys}; -use lightning::ln::channelmanager::{HTLCFailReason, PendingHTLCStatus}; +use lightning::ln::channelmanager::{HTLCFailReason, HTLCSource, PendingHTLCStatus}; use lightning::ln::msgs; use lightning::ln::msgs::{MsgDecodable, ErrorAction}; use lightning::chain::chaininterface::{FeeEstimator, ConfirmationTarget}; @@ -269,7 +269,7 @@ pub fn do_test(data: &[u8]) { loop { match get_slice!(1)[0] { 0 => { - test_err!(channel.send_htlc(slice_to_be64(get_slice!(8)), [42; 32], slice_to_be32(get_slice!(4)), msgs::OnionPacket { + test_err!(channel.send_htlc(slice_to_be64(get_slice!(8)), [42; 32], slice_to_be32(get_slice!(4)), HTLCSource::dummy(), msgs::OnionPacket { version: get_slice!(1)[0], public_key: PublicKey::from_slice(&secp_ctx, get_slice!(33)), hop_data: [0; 20*65], diff --git a/src/ln/channel.rs b/src/ln/channel.rs index 0477f68a3..0ed2dde04 100644 --- a/src/ln/channel.rs +++ b/src/ln/channel.rs @@ -16,7 +16,7 @@ use crypto::hkdf::{hkdf_extract,hkdf_expand}; use ln::msgs; use ln::msgs::{ErrorAction, HandleError, MsgEncodable}; use ln::channelmonitor::ChannelMonitor; -use ln::channelmanager::{PendingHTLCStatus, PendingForwardHTLCInfo, HTLCFailReason, HTLCFailureMsg}; +use ln::channelmanager::{PendingHTLCStatus, HTLCSource, PendingForwardHTLCInfo, HTLCFailReason, HTLCFailureMsg}; use ln::chan_utils::{TxCreationKeys,HTLCOutputInCommitment,HTLC_SUCCESS_TX_WEIGHT,HTLC_TIMEOUT_TX_WEIGHT}; use ln::chan_utils; use chain::chaininterface::{FeeEstimator,ConfirmationTarget}; @@ -165,6 +165,7 @@ struct OutboundHTLCOutput { cltv_expiry: u32, payment_hash: [u8; 32], state: OutboundHTLCState, + source: HTLCSource, /// If we're in a removed state, set if they failed, otherwise None fail_reason: Option, } @@ -188,15 +189,16 @@ enum HTLCUpdateAwaitingACK { amount_msat: u64, cltv_expiry: u32, payment_hash: [u8; 32], + source: HTLCSource, onion_routing_packet: msgs::OnionPacket, time_created: Instant, //TODO: Some kind of timeout thing-a-majig }, ClaimHTLC { payment_preimage: [u8; 32], - payment_hash: [u8; 32], // Only here for effecient duplicate detection + htlc_id: u64, }, FailHTLC { - payment_hash: [u8; 32], + htlc_id: u64, err_packet: msgs::OnionErrorPacket, }, } @@ -1019,7 +1021,7 @@ impl Channel { Ok(our_sig) } - fn get_update_fulfill_htlc(&mut self, payment_preimage_arg: [u8; 32]) -> Result<(Option, Option), HandleError> { + fn get_update_fulfill_htlc(&mut self, htlc_id_arg: u64, payment_preimage_arg: [u8; 32]) -> Result<(Option, Option), HandleError> { // Either ChannelFunded got set (which means it wont bet unset) or there is no way any // caller thought we could have something claimed (cause we wouldn't have accepted in an // incoming HTLC anyway). If we got to ShutdownComplete, callers aren't allowed to call us, @@ -1036,19 +1038,16 @@ impl Channel { let mut pending_idx = std::usize::MAX; for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() { - if htlc.payment_hash == payment_hash_calc && - htlc.state != InboundHTLCState::LocalRemoved { - if let Some(PendingHTLCStatus::Fail(_)) = htlc.pending_forward_state { - } else { - if pending_idx != std::usize::MAX { - panic!("Duplicate HTLC payment_hash, ChannelManager should have prevented this!"); - } + if htlc.htlc_id == htlc_id_arg { + assert_eq!(htlc.payment_hash, payment_hash_calc); + if htlc.state != InboundHTLCState::LocalRemoved { pending_idx = idx; + break; } } } if pending_idx == std::usize::MAX { - return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); + return Err(HandleError{err: "Unable to find a pending HTLC which matched the given HTLC ID", action: None}); } // Now update local state: @@ -1060,26 +1059,26 @@ impl Channel { if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) { for pending_update in self.holding_cell_htlc_updates.iter() { match pending_update { - &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, .. } => { - if payment_preimage_arg == *payment_preimage { + &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { return Ok((None, None)); } }, - &HTLCUpdateAwaitingACK::FailHTLC { ref payment_hash, .. } => { - if payment_hash_calc == *payment_hash { - return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); + &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { + return Err(HandleError{err: "Unable to find a pending HTLC which matched the given HTLC ID", action: None}); } }, _ => {} } } self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::ClaimHTLC { - payment_preimage: payment_preimage_arg, payment_hash: payment_hash_calc, + payment_preimage: payment_preimage_arg, htlc_id: htlc_id_arg, }); return Ok((None, Some(self.channel_monitor.clone()))); } - let htlc_id = { + { let htlc = &mut self.pending_inbound_htlcs[pending_idx]; if htlc.state == InboundHTLCState::Committed { htlc.state = InboundHTLCState::LocalRemoved; @@ -1096,18 +1095,17 @@ impl Channel { // LocalRemoved handled in the search loop panic!("Have an inbound HTLC when not awaiting remote revoke that had a garbage state"); } - htlc.htlc_id - }; + } Ok((Some(msgs::UpdateFulfillHTLC { channel_id: self.channel_id(), - htlc_id: htlc_id, + htlc_id: htlc_id_arg, payment_preimage: payment_preimage_arg, }), Some(self.channel_monitor.clone()))) } - pub fn get_update_fulfill_htlc_and_commit(&mut self, payment_preimage: [u8; 32]) -> Result<(Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>, Option), HandleError> { - match self.get_update_fulfill_htlc(payment_preimage)? { + pub fn get_update_fulfill_htlc_and_commit(&mut self, htlc_id: u64, payment_preimage: [u8; 32]) -> Result<(Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>, Option), HandleError> { + match self.get_update_fulfill_htlc(htlc_id, payment_preimage)? { (Some(update_fulfill_htlc), _) => { let (commitment, monitor_update) = self.send_commitment_no_status_check()?; Ok((Some((update_fulfill_htlc, commitment)), Some(monitor_update))) @@ -1117,7 +1115,7 @@ impl Channel { } } - pub fn get_update_fail_htlc(&mut self, payment_hash_arg: &[u8; 32], err_packet: msgs::OnionErrorPacket) -> Result, HandleError> { + pub fn get_update_fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket) -> Result, HandleError> { if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) { panic!("Was asked to fail an HTLC when channel was not in an operational state"); } @@ -1127,13 +1125,13 @@ impl Channel { if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) { for pending_update in self.holding_cell_htlc_updates.iter() { match pending_update { - &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_hash, .. } => { - if *payment_hash_arg == *payment_hash { - return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); + &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { + return Err(HandleError{err: "Unable to find a pending HTLC which matched the given HTLC ID", action: None}); } }, - &HTLCUpdateAwaitingACK::FailHTLC { ref payment_hash, .. } => { - if *payment_hash_arg == *payment_hash { + &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => { + if htlc_id_arg == htlc_id { return Ok(None); } }, @@ -1141,52 +1139,40 @@ impl Channel { } } self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::FailHTLC { - payment_hash: payment_hash_arg.clone(), + htlc_id: htlc_id_arg, err_packet, }); return Ok(None); } - let mut htlc_id = 0; let mut htlc_amount_msat = 0; for htlc in self.pending_inbound_htlcs.iter_mut() { - if htlc.payment_hash == *payment_hash_arg { + if htlc.htlc_id == htlc_id_arg { if htlc.state == InboundHTLCState::Committed { htlc.state = InboundHTLCState::LocalRemoved; } else if htlc.state == InboundHTLCState::RemoteAnnounced { - if let Some(PendingHTLCStatus::Forward(_)) = htlc.pending_forward_state { - panic!("Somehow forwarded HTLC prior to remote revocation!"); - } else { - // We have to pretend this isn't here - we're probably a duplicate with the - // same payment_hash as some other HTLC, and the other is getting failed, - // we'll fail this one as soon as remote commits to it. - continue; - } + panic!("Somehow forwarded HTLC prior to remote revocation!"); } else if htlc.state == InboundHTLCState::LocalRemoved { - return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); + return Err(HandleError{err: "Unable to find a pending HTLC which matched the given HTLC ID", action: None}); } else { panic!("Have an inbound HTLC when not awaiting remote revoke that had a garbage state"); } - if htlc_id != 0 { - panic!("Duplicate HTLC payment_hash, you probably re-used payment preimages, NEVER DO THIS!"); - } - htlc_id = htlc.htlc_id; htlc_amount_msat += htlc.amount_msat; } } if htlc_amount_msat == 0 { - return Err(HandleError{err: "Unable to find a pending HTLC which matched the given payment preimage", action: None}); + return Err(HandleError{err: "Unable to find a pending HTLC which matched the given HTLC ID", action: None}); } Ok(Some(msgs::UpdateFailHTLC { channel_id: self.channel_id(), - htlc_id, + htlc_id: htlc_id_arg, reason: err_packet })) } - pub fn get_update_fail_htlc_and_commit(&mut self, payment_hash: &[u8; 32], err_packet: msgs::OnionErrorPacket) -> Result, HandleError> { - match self.get_update_fail_htlc(payment_hash, err_packet)? { + pub fn get_update_fail_htlc_and_commit(&mut self, htlc_id: u64, err_packet: msgs::OnionErrorPacket) -> Result, HandleError> { + match self.get_update_fail_htlc(htlc_id, err_packet)? { Some(update_fail_htlc) => { let (commitment, monitor_update) = self.send_commitment_no_status_check()?; Ok(Some((update_fail_htlc, commitment, monitor_update))) @@ -1469,7 +1455,7 @@ impl Channel { /// Removes an outbound HTLC which has been commitment_signed by the remote end #[inline] - fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<[u8; 32]>, fail_reason: Option) -> Result<[u8; 32], HandleError> { + fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<[u8; 32]>, fail_reason: Option) -> Result<&HTLCSource, HandleError> { for htlc in self.pending_outbound_htlcs.iter_mut() { if htlc.htlc_id == htlc_id { match check_preimage { @@ -1489,13 +1475,13 @@ impl Channel { OutboundHTLCState::AwaitingRemoteRevokeToRemove | OutboundHTLCState::AwaitingRemovedRemoteRevoke | OutboundHTLCState::RemoteRemoved => return Err(HandleError{err: "Remote tried to fulfill HTLC that they'd already fulfilled", action: None}), } - return Ok(htlc.payment_hash.clone()); + return Ok(&htlc.source); } } Err(HandleError{err: "Remote tried to fulfill/fail an HTLC we couldn't find", action: None}) } - pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(), HandleError> { + pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<&HTLCSource, HandleError> { if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) { return Err(HandleError{err: "Got add HTLC message when channel was not in an operational state", action: None}); } @@ -1505,11 +1491,10 @@ impl Channel { let mut payment_hash = [0; 32]; sha.result(&mut payment_hash); - self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None)?; - Ok(()) + self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None) } - pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<[u8; 32], HandleError> { + pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<&HTLCSource, HandleError> { if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) { return Err(HandleError{err: "Got add HTLC message when channel was not in an operational state", action: None}); } @@ -1517,13 +1502,12 @@ impl Channel { self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason)) } - pub fn update_fail_malformed_htlc(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<(), HandleError> { + pub fn update_fail_malformed_htlc<'a>(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<&HTLCSource, HandleError> { if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) { return Err(HandleError{err: "Got add HTLC message when channel was not in an operational state", action: None}); } - self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?; - Ok(()) + self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason)) } pub fn commitment_signed(&mut self, msg: &msgs::CommitmentSigned) -> Result<(msgs::RevokeAndACK, Option, ChannelMonitor), HandleError> { @@ -1621,24 +1605,24 @@ impl Channel { self.holding_cell_htlc_updates.push(htlc_update); } else { match &htlc_update { - &HTLCUpdateAwaitingACK::AddHTLC {amount_msat, cltv_expiry, payment_hash, ref onion_routing_packet, ..} => { - match self.send_htlc(amount_msat, payment_hash, cltv_expiry, onion_routing_packet.clone()) { + &HTLCUpdateAwaitingACK::AddHTLC {amount_msat, cltv_expiry, payment_hash, ref source, ref onion_routing_packet, ..} => { + match self.send_htlc(amount_msat, payment_hash, cltv_expiry, source.clone(), onion_routing_packet.clone()) { Ok(update_add_msg_option) => update_add_htlcs.push(update_add_msg_option.unwrap()), Err(e) => { err = Some(e); } } }, - &HTLCUpdateAwaitingACK::ClaimHTLC { payment_preimage, .. } => { - match self.get_update_fulfill_htlc(payment_preimage) { + &HTLCUpdateAwaitingACK::ClaimHTLC { payment_preimage, htlc_id, .. } => { + match self.get_update_fulfill_htlc(htlc_id, payment_preimage) { Ok(update_fulfill_msg_option) => update_fulfill_htlcs.push(update_fulfill_msg_option.0.unwrap()), Err(e) => { err = Some(e); } } }, - &HTLCUpdateAwaitingACK::FailHTLC { payment_hash, ref err_packet } => { - match self.get_update_fail_htlc(&payment_hash, err_packet.clone()) { + &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, ref err_packet } => { + match self.get_update_fail_htlc(htlc_id, err_packet.clone()) { Ok(update_fail_msg_option) => update_fail_htlcs.push(update_fail_msg_option.unwrap()), Err(e) => { err = Some(e); @@ -1676,7 +1660,7 @@ impl Channel { /// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail, /// generating an appropriate error *after* the channel state has been updated based on the /// revoke_and_ack message. - pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK) -> Result<(Option, Vec, Vec<([u8; 32], HTLCFailReason)>, ChannelMonitor), HandleError> { + pub fn revoke_and_ack(&mut self, msg: &msgs::RevokeAndACK) -> Result<(Option, Vec<(PendingForwardHTLCInfo, u64)>, Vec<(HTLCSource, [u8; 32], HTLCFailReason)>, ChannelMonitor), HandleError> { if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) { return Err(HandleError{err: "Got revoke/ACK message when channel was not in an operational state", action: None}); } @@ -1714,7 +1698,7 @@ impl Channel { self.pending_outbound_htlcs.retain(|htlc| { if htlc.state == OutboundHTLCState::AwaitingRemovedRemoteRevoke { if let Some(reason) = htlc.fail_reason.clone() { // We really want take() here, but, again, non-mut ref :( - revoked_htlcs.push((htlc.payment_hash, reason)); + revoked_htlcs.push((htlc.source.clone(), htlc.payment_hash, reason)); } else { // They fulfilled, so we sent them money value_to_self_msat_diff -= htlc.amount_msat as i64; @@ -1737,7 +1721,7 @@ impl Channel { } }, PendingHTLCStatus::Forward(forward_info) => { - to_forward_infos.push(forward_info); + to_forward_infos.push((forward_info, htlc.htlc_id)); htlc.state = InboundHTLCState::Committed; } } @@ -1792,7 +1776,7 @@ impl Channel { Ok(()) } - pub fn shutdown(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::Shutdown) -> Result<(Option, Option, Vec<[u8; 32]>), HandleError> { + pub fn shutdown(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::Shutdown) -> Result<(Option, Option, Vec<(HTLCSource, [u8; 32])>), HandleError> { if self.channel_state < ChannelState::FundingSent as u32 { self.channel_state = ChannelState::ShutdownComplete as u32; self.channel_update_count += 1; @@ -1851,8 +1835,8 @@ impl Channel { let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len()); self.holding_cell_htlc_updates.retain(|htlc_update| { match htlc_update { - &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, .. } => { - dropped_outbound_htlcs.push(payment_hash.clone()); + &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => { + dropped_outbound_htlcs.push((source.clone(), payment_hash.clone())); false }, _ => true @@ -2357,7 +2341,7 @@ impl Channel { /// waiting on the remote peer to send us a revoke_and_ack during which time we cannot add new /// HTLCs on the wire or we wouldn't be able to determine what they actually ACK'ed. /// You MUST call send_commitment prior to any other calls on this Channel - pub fn send_htlc(&mut self, amount_msat: u64, payment_hash: [u8; 32], cltv_expiry: u32, onion_routing_packet: msgs::OnionPacket) -> Result, HandleError> { + pub fn send_htlc(&mut self, amount_msat: u64, payment_hash: [u8; 32], cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket) -> Result, HandleError> { if (self.channel_state & (ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK)) != (ChannelState::ChannelFunded as u32) { return Err(HandleError{err: "Cannot send HTLC until channel is fully established and we haven't started shutting down", action: None}); } @@ -2392,6 +2376,7 @@ impl Channel { amount_msat: amount_msat, payment_hash: payment_hash, cltv_expiry: cltv_expiry, + source, onion_routing_packet: onion_routing_packet, time_created: Instant::now(), }); @@ -2404,6 +2389,7 @@ impl Channel { payment_hash: payment_hash.clone(), cltv_expiry: cltv_expiry, state: OutboundHTLCState::LocalAnnounced, + source, fail_reason: None, }); @@ -2492,8 +2478,8 @@ impl Channel { /// to send to the remote peer in one go. /// Shorthand for calling send_htlc() followed by send_commitment(), see docs on those for /// more info. - pub fn send_htlc_and_commit(&mut self, amount_msat: u64, payment_hash: [u8; 32], cltv_expiry: u32, onion_routing_packet: msgs::OnionPacket) -> Result, HandleError> { - match self.send_htlc(amount_msat, payment_hash, cltv_expiry, onion_routing_packet)? { + pub fn send_htlc_and_commit(&mut self, amount_msat: u64, payment_hash: [u8; 32], cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket) -> Result, HandleError> { + match self.send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet)? { Some(update_add_htlc) => { let (commitment_signed, monitor_update) = self.send_commitment_no_status_check()?; Ok(Some((update_add_htlc, commitment_signed, monitor_update))) @@ -2504,7 +2490,7 @@ impl Channel { /// Begins the shutdown process, getting a message for the remote peer and returning all /// holding cell HTLCs for payment failure. - pub fn get_shutdown(&mut self) -> Result<(msgs::Shutdown, Vec<[u8; 32]>), HandleError> { + pub fn get_shutdown(&mut self) -> Result<(msgs::Shutdown, Vec<(HTLCSource, [u8; 32])>), HandleError> { for htlc in self.pending_outbound_htlcs.iter() { if htlc.state == OutboundHTLCState::LocalAnnounced { return Err(HandleError{err: "Cannot begin shutdown with pending HTLCs, call send_commitment first", action: None}); @@ -2531,8 +2517,8 @@ impl Channel { let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len()); self.holding_cell_htlc_updates.retain(|htlc_update| { match htlc_update { - &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, .. } => { - dropped_outbound_htlcs.push(payment_hash.clone()); + &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => { + dropped_outbound_htlcs.push((source.clone(), payment_hash.clone())); false }, _ => true @@ -2550,7 +2536,7 @@ impl Channel { /// those explicitly stated to be allowed after shutdown completes, eg some simple getters). /// Also returns the list of payment_hashes for channels which we can safely fail backwards /// immediately (others we will have to allow to time out). - pub fn force_shutdown(&mut self) -> (Vec, Vec<[u8; 32]>) { + pub fn force_shutdown(&mut self) -> (Vec, Vec<(HTLCSource, [u8; 32])>) { assert!(self.channel_state != ChannelState::ShutdownComplete as u32); // We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and @@ -2558,8 +2544,8 @@ impl Channel { let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len()); for htlc_update in self.holding_cell_htlc_updates.drain(..) { match htlc_update { - HTLCUpdateAwaitingACK::AddHTLC { payment_hash, .. } => { - dropped_outbound_htlcs.push(payment_hash); + HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } => { + dropped_outbound_htlcs.push((source, payment_hash)); }, _ => {} } @@ -2567,7 +2553,7 @@ impl Channel { for htlc in self.pending_outbound_htlcs.drain(..) { if htlc.state == OutboundHTLCState::LocalAnnounced { - dropped_outbound_htlcs.push(htlc.payment_hash); + dropped_outbound_htlcs.push((htlc.source, htlc.payment_hash)); } //TODO: Do something with the remaining HTLCs //(we need to have the ChannelManager monitor them so we can claim the inbound HTLCs @@ -2590,6 +2576,7 @@ mod tests { use bitcoin::blockdata::script::Script; use bitcoin::blockdata::transaction::Transaction; use hex; + use ln::channelmanager::HTLCSource; use ln::channel::{Channel,ChannelKeys,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,TxCreationKeys}; use ln::channel::MAX_FUNDING_SATOSHIS; use ln::chan_utils; @@ -2766,6 +2753,7 @@ mod tests { cltv_expiry: 502, payment_hash: [0; 32], state: OutboundHTLCState::Committed, + source: HTLCSource::dummy(), fail_reason: None, }; let mut sha = Sha256::new(); @@ -2780,6 +2768,7 @@ mod tests { cltv_expiry: 503, payment_hash: [0; 32], state: OutboundHTLCState::Committed, + source: HTLCSource::dummy(), fail_reason: None, }; let mut sha = Sha256::new(); diff --git a/src/ln/channelmanager.rs b/src/ln/channelmanager.rs index baf211fdb..8baca6019 100644 --- a/src/ln/channelmanager.rs +++ b/src/ln/channelmanager.rs @@ -36,16 +36,31 @@ use std::sync::{Mutex,MutexGuard,Arc}; use std::sync::atomic::{AtomicUsize, Ordering}; use std::time::{Instant,Duration}; +/// We hold various information about HTLC relay in the HTLC objects in Channel itself: +/// +/// Upon receipt of an HTLC from a peer, we'll give it a PendingHTLCStatus indicating if it should +/// forward the HTLC with information it will give back to us when it does so, or if it should Fail +/// the HTLC with the relevant message for the Channel to handle giving to the remote peer. +/// +/// When a Channel forwards an HTLC to its peer, it will give us back the PendingForwardHTLCInfo +/// which we will use to construct an outbound HTLC, with a relevant HTLCSource::PreviousHopData +/// filled in to indicate where it came from (which we can use to either fail-backwards or fulfill +/// the HTLC backwards along the relevant path). +/// Alternatively, we can fill an outbound HTLC with a HTLCSource::OutboundRoute indicating this is +/// our payment, which we can use to decode errors or inform the user that the payment was sent. mod channel_held_info { use ln::msgs; + use ln::router::Route; + use secp256k1::key::SecretKey; + use secp256k1::ecdh::SharedSecret; /// Stores the info we will need to send when we want to forward an HTLC onwards #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug pub struct PendingForwardHTLCInfo { pub(super) onion_packet: Option, + pub(super) incoming_shared_secret: SharedSecret, pub(super) payment_hash: [u8; 32], pub(super) short_channel_id: u64, - pub(super) prev_short_channel_id: u64, pub(super) amt_to_forward: u64, pub(super) outgoing_cltv_value: u32, } @@ -66,17 +81,47 @@ mod channel_held_info { #[cfg(feature = "fuzztarget")] impl PendingHTLCStatus { pub fn dummy() -> Self { + let secp_ctx = ::secp256k1::Secp256k1::signing_only(); PendingHTLCStatus::Forward(PendingForwardHTLCInfo { onion_packet: None, + incoming_shared_secret: SharedSecret::new(&secp_ctx, + &::secp256k1::key::PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&secp_ctx, &[1; 32]).unwrap()), + &SecretKey::from_slice(&secp_ctx, &[1; 32]).unwrap()), payment_hash: [0; 32], short_channel_id: 0, - prev_short_channel_id: 0, amt_to_forward: 0, outgoing_cltv_value: 0, }) } } + /// Tracks the inbound corresponding to an outbound HTLC + #[derive(Clone)] + pub struct HTLCPreviousHopData { + pub(super) short_channel_id: u64, + pub(super) htlc_id: u64, + pub(super) incoming_packet_shared_secret: SharedSecret, + } + + /// Tracks the inbound corresponding to an outbound HTLC + #[derive(Clone)] + pub enum HTLCSource { + PreviousHopData(HTLCPreviousHopData), + OutboundRoute { + route: Route, + session_priv: SecretKey, + }, + } + #[cfg(any(test, feature = "fuzztarget"))] + impl HTLCSource { + pub fn dummy() -> Self { + HTLCSource::OutboundRoute { + route: Route { hops: Vec::new() }, + session_priv: SecretKey::from_slice(&::secp256k1::Secp256k1::without_caps(), &[1; 32]).unwrap(), + } + } + } + #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug pub enum HTLCFailReason { ErrorPacket { @@ -102,24 +147,6 @@ pub use self::channel_held_info::*; #[cfg(not(feature = "fuzztarget"))] pub(crate) use self::channel_held_info::*; -enum PendingOutboundHTLC { - IntermediaryHopData { - source_short_channel_id: u64, - incoming_packet_shared_secret: SharedSecret, - }, - OutboundRoute { - route: Route, - session_priv: SecretKey, - }, - /// Used for channel rebalancing - CycledRoute { - source_short_channel_id: u64, - incoming_packet_shared_secret: SharedSecret, - route: Route, - session_priv: SecretKey, - } -} - struct MsgHandleErrInternal { err: msgs::HandleError, needs_channel_force_close: bool, @@ -171,6 +198,12 @@ impl MsgHandleErrInternal { /// probably increase this significantly. const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u32 = 50; +struct HTLCForwardInfo { + prev_short_channel_id: u64, + prev_htlc_id: u64, + forward_info: PendingForwardHTLCInfo, +} + struct ChannelHolder { by_id: HashMap<[u8; 32], Channel>, short_to_id: HashMap, @@ -179,18 +212,18 @@ struct ChannelHolder { /// Note that while this is held in the same mutex as the channels themselves, no consistency /// guarantees are made about there existing a channel with the short id here, nor the short /// ids in the PendingForwardHTLCInfo! - forward_htlcs: HashMap>, + forward_htlcs: HashMap>, /// Note that while this is held in the same mutex as the channels themselves, no consistency /// guarantees are made about the channels given here actually existing anymore by the time you /// go to read them! - claimable_htlcs: HashMap<[u8; 32], PendingOutboundHTLC>, + claimable_htlcs: HashMap<[u8; 32], Vec>, } struct MutChannelHolder<'a> { by_id: &'a mut HashMap<[u8; 32], Channel>, short_to_id: &'a mut HashMap, next_forward: &'a mut Instant, - forward_htlcs: &'a mut HashMap>, - claimable_htlcs: &'a mut HashMap<[u8; 32], PendingOutboundHTLC>, + forward_htlcs: &'a mut HashMap>, + claimable_htlcs: &'a mut HashMap<[u8; 32], Vec>, } impl ChannelHolder { fn borrow_parts(&mut self) -> MutChannelHolder { @@ -392,7 +425,7 @@ impl ChannelManager { /// pending HTLCs, the channel will be closed on chain. /// May generate a SendShutdown event on success, which should be relayed. pub fn close_channel(&self, channel_id: &[u8; 32]) -> Result<(), HandleError> { - let (res, node_id, chan_option) = { + let (mut res, node_id, chan_option) = { let mut channel_state_lock = self.channel_state.lock().unwrap(); let channel_state = channel_state_lock.borrow_parts(); match channel_state.by_id.entry(channel_id.clone()) { @@ -408,9 +441,9 @@ impl ChannelManager { hash_map::Entry::Vacant(_) => return Err(HandleError{err: "No such channel", action: None}) } }; - for payment_hash in res.1 { + for htlc_source in res.1.drain(..) { // unknown_next_peer...I dunno who that is anymore.... - self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), &payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }); + self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }); } let chan_update = if let Some(chan) = chan_option { if let Ok(update) = self.get_channel_update(&chan) { @@ -433,11 +466,11 @@ impl ChannelManager { } #[inline] - fn finish_force_close_channel(&self, shutdown_res: (Vec, Vec<[u8; 32]>)) { - let (local_txn, failed_htlcs) = shutdown_res; - for payment_hash in failed_htlcs { + fn finish_force_close_channel(&self, shutdown_res: (Vec, Vec<(HTLCSource, [u8; 32])>)) { + let (local_txn, mut failed_htlcs) = shutdown_res; + for htlc_source in failed_htlcs.drain(..) { // unknown_next_peer...I dunno who that is anymore.... - self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), &payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }); + self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }); } for tx in local_txn { self.tx_broadcaster.broadcast_transaction(&tx); @@ -722,7 +755,7 @@ impl ChannelManager { ChannelManager::encrypt_failure_packet(shared_secret, &failure_packet.encode()[..]) } - fn decode_update_add_htlc_onion(&self, msg: &msgs::UpdateAddHTLC) -> (PendingHTLCStatus, Option, MutexGuard) { + fn decode_update_add_htlc_onion(&self, msg: &msgs::UpdateAddHTLC) -> (PendingHTLCStatus, MutexGuard) { macro_rules! get_onion_hash { () => { { @@ -742,7 +775,7 @@ impl ChannelManager { htlc_id: msg.htlc_id, sha256_of_onion: get_onion_hash!(), failure_code: 0x8000 | 0x4000 | 6, - })), None, self.channel_state.lock().unwrap()); + })), self.channel_state.lock().unwrap()); } let shared_secret = SharedSecret::new(&self.secp_ctx, &msg.onion_routing_packet.public_key.unwrap(), &self.our_network_key); @@ -760,7 +793,7 @@ impl ChannelManager { channel_id: msg.channel_id, htlc_id: msg.htlc_id, reason: ChannelManager::build_first_hop_failure_packet(&shared_secret, $err_code, $data), - })), Some(shared_secret), channel_state.unwrap()); + })), channel_state.unwrap()); } } } @@ -818,7 +851,7 @@ impl ChannelManager { onion_packet: None, payment_hash: msg.payment_hash.clone(), short_channel_id: 0, - prev_short_channel_id: 0, + incoming_shared_secret: shared_secret.clone(), amt_to_forward: next_hop_data.data.amt_to_forward, outgoing_cltv_value: next_hop_data.data.outgoing_cltv_value, }) @@ -858,7 +891,7 @@ impl ChannelManager { onion_packet: Some(outgoing_packet), payment_hash: msg.payment_hash.clone(), short_channel_id: next_hop_data.data.short_channel_id, - prev_short_channel_id: 0, + incoming_shared_secret: shared_secret.clone(), amt_to_forward: next_hop_data.data.amt_to_forward, outgoing_cltv_value: next_hop_data.data.outgoing_cltv_value, }) @@ -896,7 +929,7 @@ impl ChannelManager { } } - (pending_forward_info, Some(shared_secret), channel_state.unwrap()) + (pending_forward_info, channel_state.unwrap()) } /// only fails if the channel does not yet have an assigned short_id @@ -975,11 +1008,6 @@ impl ChannelManager { Some(id) => id.clone() }; - let claimable_htlc_entry = channel_state.claimable_htlcs.entry(payment_hash.clone()); - if let hash_map::Entry::Occupied(_) = claimable_htlc_entry { - return Err(HandleError{err: "Already had pending HTLC with the same payment_hash", action: None}); - } - let res = { let chan = channel_state.by_id.get_mut(&id).unwrap(); if chan.get_their_node_id() != route.hops.first().unwrap().pubkey { @@ -988,16 +1016,14 @@ impl ChannelManager { if !chan.is_live() { return Err(HandleError{err: "Peer for first hop currently disconnected!", action: None}); } - chan.send_htlc_and_commit(htlc_msat, payment_hash, htlc_cltv, onion_packet)? + chan.send_htlc_and_commit(htlc_msat, payment_hash.clone(), htlc_cltv, HTLCSource::OutboundRoute { + route: route.clone(), + session_priv: session_priv.clone(), + }, onion_packet)? }; let first_hop_node_id = route.hops.first().unwrap().pubkey; - claimable_htlc_entry.or_insert(PendingOutboundHTLC::OutboundRoute { - route, - session_priv, - }); - match res { Some(msgs) => (first_hop_node_id, msgs), None => return Ok(()), @@ -1005,7 +1031,7 @@ impl ChannelManager { }; if let Err(_e) = self.monitor.add_update_monitor(chan_monitor.get_funding_txo().unwrap(), chan_monitor) { - unimplemented!(); // maybe remove from claimable_htlcs? + unimplemented!(); } let mut events = self.pending_events.lock().unwrap(); @@ -1060,7 +1086,7 @@ impl ChannelManager { } }; // Release channel lock for install_watch_outpoint call, if let Err(_e) = self.monitor.add_update_monitor(chan_monitor.get_funding_txo().unwrap(), chan_monitor) { - unimplemented!(); // maybe remove from claimable_htlcs? + unimplemented!(); } add_pending_event!(events::Event::SendFundingCreated { node_id: chan.get_their_node_id(), @@ -1110,14 +1136,19 @@ impl ChannelManager { return; } - for (short_chan_id, pending_forwards) in channel_state.forward_htlcs.drain() { + for (short_chan_id, mut pending_forwards) in channel_state.forward_htlcs.drain() { if short_chan_id != 0 { let forward_chan_id = match channel_state.short_to_id.get(&short_chan_id) { Some(chan_id) => chan_id.clone(), None => { failed_forwards.reserve(pending_forwards.len()); - for forward_info in pending_forwards { - failed_forwards.push((forward_info.payment_hash, 0x4000 | 10, None)); + for HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info } in pending_forwards.drain(..) { + let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData { + short_channel_id: prev_short_channel_id, + htlc_id: prev_htlc_id, + incoming_packet_shared_secret: forward_info.incoming_shared_secret, + }); + failed_forwards.push((htlc_source, forward_info.payment_hash, 0x4000 | 10, None)); } continue; } @@ -1125,11 +1156,16 @@ impl ChannelManager { let forward_chan = &mut channel_state.by_id.get_mut(&forward_chan_id).unwrap(); let mut add_htlc_msgs = Vec::new(); - for forward_info in pending_forwards { - match forward_chan.send_htlc(forward_info.amt_to_forward, forward_info.payment_hash, forward_info.outgoing_cltv_value, forward_info.onion_packet.unwrap()) { + for HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info } in pending_forwards.drain(..) { + let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData { + short_channel_id: prev_short_channel_id, + htlc_id: prev_htlc_id, + incoming_packet_shared_secret: forward_info.incoming_shared_secret, + }); + match forward_chan.send_htlc(forward_info.amt_to_forward, forward_info.payment_hash, forward_info.outgoing_cltv_value, htlc_source.clone(), forward_info.onion_packet.unwrap()) { Err(_e) => { let chan_update = self.get_channel_update(forward_chan).unwrap(); - failed_forwards.push((forward_info.payment_hash, 0x1000 | 7, Some(chan_update))); + failed_forwards.push((htlc_source, forward_info.payment_hash, 0x1000 | 7, Some(chan_update))); continue; }, Ok(update_add) => { @@ -1174,7 +1210,16 @@ impl ChannelManager { })); } } else { - for forward_info in pending_forwards { + for HTLCForwardInfo { prev_short_channel_id, prev_htlc_id, forward_info } in pending_forwards.drain(..) { + let prev_hop_data = HTLCPreviousHopData { + short_channel_id: prev_short_channel_id, + htlc_id: prev_htlc_id, + incoming_packet_shared_secret: forward_info.incoming_shared_secret, + }; + match channel_state.claimable_htlcs.entry(forward_info.payment_hash) { + hash_map::Entry::Occupied(mut entry) => entry.get_mut().push(prev_hop_data), + hash_map::Entry::Vacant(mut entry) => { entry.insert(vec![prev_hop_data]); }, + }; new_events.push((None, events::Event::PaymentReceived { payment_hash: forward_info.payment_hash, amt: forward_info.amt_to_forward, @@ -1184,10 +1229,10 @@ impl ChannelManager { } } - for failed_forward in failed_forwards.drain(..) { - match failed_forward.2 { - None => self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), &failed_forward.0, HTLCFailReason::Reason { failure_code: failed_forward.1, data: Vec::new() }), - Some(chan_update) => self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), &failed_forward.0, HTLCFailReason::Reason { failure_code: failed_forward.1, data: chan_update.encode_with_len() }), + for (htlc_source, payment_hash, failure_code, update) in failed_forwards.drain(..) { + match update { + None => self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source, &payment_hash, HTLCFailReason::Reason { failure_code, data: Vec::new() }), + Some(chan_update) => self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source, &payment_hash, HTLCFailReason::Reason { failure_code, data: chan_update.encode_with_len() }), }; } @@ -1211,7 +1256,15 @@ impl ChannelManager { /// Indicates that the preimage for payment_hash is unknown after a PaymentReceived event. pub fn fail_htlc_backwards(&self, payment_hash: &[u8; 32]) -> bool { - self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: Vec::new() }) + let mut channel_state = Some(self.channel_state.lock().unwrap()); + let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(payment_hash); + if let Some(mut sources) = removed_source { + for htlc_with_hash in sources.drain(..) { + if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); } + self.fail_htlc_backwards_internal(channel_state.take().unwrap(), HTLCSource::PreviousHopData(htlc_with_hash), payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: Vec::new() }); + } + true + } else { false } } /// Fails an HTLC backwards to the sender of it to us. @@ -1220,37 +1273,17 @@ impl ChannelManager { /// to fail and take the channel_state lock for each iteration (as we take ownership and may /// drop it). In other words, no assumptions are made that entries in claimable_htlcs point to /// still-available channels. - fn fail_htlc_backwards_internal(&self, mut channel_state: MutexGuard, payment_hash: &[u8; 32], onion_error: HTLCFailReason) -> bool { - let mut pending_htlc = { - match channel_state.claimable_htlcs.remove(payment_hash) { - Some(pending_htlc) => pending_htlc, - None => return false, - } - }; - - match pending_htlc { - PendingOutboundHTLC::CycledRoute { source_short_channel_id, incoming_packet_shared_secret, route, session_priv } => { - channel_state.claimable_htlcs.insert(payment_hash.clone(), PendingOutboundHTLC::OutboundRoute { - route, - session_priv, - }); - pending_htlc = PendingOutboundHTLC::IntermediaryHopData { source_short_channel_id, incoming_packet_shared_secret }; - }, - _ => {} - } - - match pending_htlc { - PendingOutboundHTLC::CycledRoute { .. } => unreachable!(), - PendingOutboundHTLC::OutboundRoute { .. } => { + fn fail_htlc_backwards_internal(&self, mut channel_state: MutexGuard, source: HTLCSource, payment_hash: &[u8; 32], onion_error: HTLCFailReason) { + match source { + HTLCSource::OutboundRoute { .. } => { mem::drop(channel_state); let mut pending_events = self.pending_events.lock().unwrap(); pending_events.push(events::Event::PaymentFailed { payment_hash: payment_hash.clone() }); - false }, - PendingOutboundHTLC::IntermediaryHopData { source_short_channel_id, incoming_packet_shared_secret } => { + HTLCSource::PreviousHopData(HTLCPreviousHopData { short_channel_id, htlc_id, incoming_packet_shared_secret }) => { let err_packet = match onion_error { HTLCFailReason::Reason { failure_code, data } => { let packet = ChannelManager::build_failure_packet(&incoming_packet_shared_secret, failure_code, &data[..]).encode(); @@ -1262,17 +1295,17 @@ impl ChannelManager { }; let (node_id, fail_msgs) = { - let chan_id = match channel_state.short_to_id.get(&source_short_channel_id) { + let chan_id = match channel_state.short_to_id.get(&short_channel_id) { Some(chan_id) => chan_id.clone(), - None => return false + None => return }; let chan = channel_state.by_id.get_mut(&chan_id).unwrap(); - match chan.get_update_fail_htlc_and_commit(payment_hash, err_packet) { + match chan.get_update_fail_htlc_and_commit(htlc_id, err_packet) { Ok(msg) => (chan.get_their_node_id(), msg), Err(_e) => { //TODO: Do something with e? - return false; + return; }, } }; @@ -1299,8 +1332,6 @@ impl ChannelManager { }, None => {}, } - - true }, } } @@ -1310,69 +1341,51 @@ impl ChannelManager { /// should probably kick the net layer to go send messages if this returns true! /// May panic if called except in response to a PaymentReceived event. pub fn claim_funds(&self, payment_preimage: [u8; 32]) -> bool { - self.claim_funds_internal(payment_preimage, true) - } - fn claim_funds_internal(&self, payment_preimage: [u8; 32], from_user: bool) -> bool { let mut sha = Sha256::new(); sha.input(&payment_preimage); let mut payment_hash = [0; 32]; sha.result(&mut payment_hash); - let mut channel_state = self.channel_state.lock().unwrap(); - let mut pending_htlc = { - match channel_state.claimable_htlcs.remove(&payment_hash) { - Some(pending_htlc) => pending_htlc, - None => return false, + let mut channel_state = Some(self.channel_state.lock().unwrap()); + let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&payment_hash); + if let Some(mut sources) = removed_source { + for htlc_with_hash in sources.drain(..) { + if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); } + self.claim_funds_internal(channel_state.take().unwrap(), HTLCSource::PreviousHopData(htlc_with_hash), payment_preimage); } - }; - - match pending_htlc { - PendingOutboundHTLC::CycledRoute { source_short_channel_id, incoming_packet_shared_secret, route, session_priv } => { - if from_user { // This was the end hop back to us - pending_htlc = PendingOutboundHTLC::IntermediaryHopData { source_short_channel_id, incoming_packet_shared_secret }; - channel_state.claimable_htlcs.insert(payment_hash, PendingOutboundHTLC::OutboundRoute { route, session_priv }); - } else { // This came from the first upstream node - // Bank error in our favor! Maybe we should tell the user this somehow??? - pending_htlc = PendingOutboundHTLC::OutboundRoute { route, session_priv }; - channel_state.claimable_htlcs.insert(payment_hash, PendingOutboundHTLC::IntermediaryHopData { source_short_channel_id, incoming_packet_shared_secret }); - } - }, - _ => {}, - } - - match pending_htlc { - PendingOutboundHTLC::CycledRoute { .. } => unreachable!(), - PendingOutboundHTLC::OutboundRoute { .. } => { - if from_user { - panic!("Called claim_funds with a preimage for an outgoing payment. There is nothing we can do with this, and something is seriously wrong if you knew this..."); - } + true + } else { false } + } + fn claim_funds_internal(&self, mut channel_state: MutexGuard, source: HTLCSource, payment_preimage: [u8; 32]) { + match source { + HTLCSource::OutboundRoute { .. } => { mem::drop(channel_state); let mut pending_events = self.pending_events.lock().unwrap(); pending_events.push(events::Event::PaymentSent { payment_preimage }); - false }, - PendingOutboundHTLC::IntermediaryHopData { source_short_channel_id, .. } => { + HTLCSource::PreviousHopData(HTLCPreviousHopData { short_channel_id, htlc_id, .. }) => { + //TODO: Delay the claimed_funds relaying just like we do outbound relay! let (node_id, fulfill_msgs) = { - let chan_id = match channel_state.short_to_id.get(&source_short_channel_id) { + let chan_id = match channel_state.short_to_id.get(&short_channel_id) { Some(chan_id) => chan_id.clone(), None => { // TODO: There is probably a channel manager somewhere that needs to // learn the preimage as the channel already hit the chain and that's // why its missing. - return false + return } }; let chan = channel_state.by_id.get_mut(&chan_id).unwrap(); - match chan.get_update_fulfill_htlc_and_commit(payment_preimage) { + match chan.get_update_fulfill_htlc_and_commit(htlc_id, payment_preimage) { Ok(msg) => (chan.get_their_node_id(), msg), Err(_e) => { // TODO: There is probably a channel manager somewhere that needs to // learn the preimage as the channel may be about to hit the chain. //TODO: Do something with e? - return false; + return }, } }; @@ -1397,7 +1410,6 @@ impl ChannelManager { } }); } - true }, } } @@ -1556,7 +1568,7 @@ impl ChannelManager { } fn internal_shutdown(&self, their_node_id: &PublicKey, msg: &msgs::Shutdown) -> Result<(Option, Option), MsgHandleErrInternal> { - let (res, chan_option) = { + let (mut res, chan_option) = { let mut channel_state_lock = self.channel_state.lock().unwrap(); let channel_state = channel_state_lock.borrow_parts(); @@ -1577,9 +1589,9 @@ impl ChannelManager { hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel", msg.channel_id)) } }; - for payment_hash in res.2 { + for htlc_source in res.2.drain(..) { // unknown_next_peer...I dunno who that is anymore.... - self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), &payment_hash, HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }); + self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }); } if let Some(chan) = chan_option { if let Ok(update) = self.get_channel_update(&chan) { @@ -1642,38 +1654,10 @@ impl ChannelManager { //encrypted with the same key. Its not immediately obvious how to usefully exploit that, //but we should prevent it anyway. - let (mut pending_forward_info, shared_secret, mut channel_state_lock) = self.decode_update_add_htlc_onion(msg); + let (pending_forward_info, mut channel_state_lock) = self.decode_update_add_htlc_onion(msg); let channel_state = channel_state_lock.borrow_parts(); - let claimable_htlcs_entry = channel_state.claimable_htlcs.entry(msg.payment_hash.clone()); - - // We dont correctly handle payments that route through us twice on their way to their - // destination. That's OK since those nodes are probably busted or trying to do network - // mapping through repeated loops. In either case, we want them to stop talking to us, so - // we send permanent_node_failure. - let mut will_forward = false; - if let PendingHTLCStatus::Forward(PendingForwardHTLCInfo { short_channel_id, .. }) = pending_forward_info { - if let &hash_map::Entry::Occupied(ref e) = &claimable_htlcs_entry { - let mut acceptable_cycle = false; - if let &PendingOutboundHTLC::OutboundRoute { .. } = e.get() { - acceptable_cycle = short_channel_id == 0; - } - if !acceptable_cycle { - log_info!(self, "Failed to accept incoming HTLC: Payment looped through us twice"); - pending_forward_info = PendingHTLCStatus::Fail(HTLCFailureMsg::Relay(msgs::UpdateFailHTLC { - channel_id: msg.channel_id, - htlc_id: msg.htlc_id, - reason: ChannelManager::build_first_hop_failure_packet(&shared_secret.unwrap(), 0x4000 | 0x2000 | 2, &[0;0]), - })); - } else { - will_forward = true; - } - } else { - will_forward = true; - } - } - - let (source_short_channel_id, res) = match channel_state.by_id.get_mut(&msg.channel_id) { + match channel_state.by_id.get_mut(&msg.channel_id) { Some(chan) => { if chan.get_their_node_id() != *their_node_id { //TODO: here MsgHandleErrInternal, #153 case @@ -1682,66 +1666,31 @@ impl ChannelManager { if !chan.is_usable() { return Err(MsgHandleErrInternal::from_no_close(HandleError{err: "Channel not yet available for receiving HTLCs", action: Some(msgs::ErrorAction::IgnoreError)})); } - let short_channel_id = chan.get_short_channel_id().unwrap(); - if let PendingHTLCStatus::Forward(ref mut forward_info) = pending_forward_info { - forward_info.prev_short_channel_id = short_channel_id; - } - (short_channel_id, chan.update_add_htlc(&msg, pending_forward_info).map_err(|e| MsgHandleErrInternal::from_maybe_close(e))?) + chan.update_add_htlc(&msg, pending_forward_info).map_err(|e| MsgHandleErrInternal::from_maybe_close(e)) }, None => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel", msg.channel_id)) - }; - - if will_forward { - match claimable_htlcs_entry { - hash_map::Entry::Occupied(mut e) => { - let outbound_route = e.get_mut(); - let (route, session_priv) = match outbound_route { - &mut PendingOutboundHTLC::OutboundRoute { ref route, ref session_priv } => { - (route.clone(), session_priv.clone()) - }, - _ => unreachable!(), - }; - *outbound_route = PendingOutboundHTLC::CycledRoute { - source_short_channel_id, - incoming_packet_shared_secret: shared_secret.unwrap(), - route, - session_priv, - }; - }, - hash_map::Entry::Vacant(e) => { - e.insert(PendingOutboundHTLC::IntermediaryHopData { - source_short_channel_id, - incoming_packet_shared_secret: shared_secret.unwrap(), - }); - } - } } - - Ok(res) } fn internal_update_fulfill_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFulfillHTLC) -> Result<(), MsgHandleErrInternal> { - //TODO: Delay the claimed_funds relaying just like we do outbound relay! - // Claim funds first, cause we don't really care if the channel we received the message on - // is broken, we may have enough info to get our own money! - self.claim_funds_internal(msg.payment_preimage.clone(), false); - let mut channel_state = self.channel_state.lock().unwrap(); - match channel_state.by_id.get_mut(&msg.channel_id) { + let htlc_source = match channel_state.by_id.get_mut(&msg.channel_id) { Some(chan) => { if chan.get_their_node_id() != *their_node_id { //TODO: here and below MsgHandleErrInternal, #153 case return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.channel_id)); } - chan.update_fulfill_htlc(&msg).map_err(|e| MsgHandleErrInternal::from_maybe_close(e)) + chan.update_fulfill_htlc(&msg).map_err(|e| MsgHandleErrInternal::from_maybe_close(e))?.clone() }, None => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel", msg.channel_id)) - } + }; + self.claim_funds_internal(channel_state, htlc_source, msg.payment_preimage.clone()); + Ok(()) } fn internal_update_fail_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) -> Result, MsgHandleErrInternal> { let mut channel_state = self.channel_state.lock().unwrap(); - let payment_hash = match channel_state.by_id.get_mut(&msg.channel_id) { + let htlc_source = match channel_state.by_id.get_mut(&msg.channel_id) { Some(chan) => { if chan.get_their_node_id() != *their_node_id { //TODO: here and below MsgHandleErrInternal, #153 case @@ -1752,66 +1701,62 @@ impl ChannelManager { None => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel", msg.channel_id)) }?; - if let Some(pending_htlc) = channel_state.claimable_htlcs.get(&payment_hash) { - match pending_htlc { - &PendingOutboundHTLC::OutboundRoute { ref route, ref session_priv } => { - // Handle packed channel/node updates for passing back for the route handler - let mut packet_decrypted = msg.reason.data.clone(); - let mut res = None; - Self::construct_onion_keys_callback(&self.secp_ctx, &route, &session_priv, |shared_secret, _, _, route_hop| { - if res.is_some() { return; } - - let ammag = ChannelManager::gen_ammag_from_shared_secret(&shared_secret); - - let mut decryption_tmp = Vec::with_capacity(packet_decrypted.len()); - decryption_tmp.resize(packet_decrypted.len(), 0); - let mut chacha = ChaCha20::new(&ammag, &[0u8; 8]); - chacha.process(&packet_decrypted, &mut decryption_tmp[..]); - packet_decrypted = decryption_tmp; - - if let Ok(err_packet) = msgs::DecodedOnionErrorPacket::decode(&packet_decrypted) { - if err_packet.failuremsg.len() >= 2 { - let um = ChannelManager::gen_um_from_shared_secret(&shared_secret); - - let mut hmac = Hmac::new(Sha256::new(), &um); - hmac.input(&err_packet.encode()[32..]); - let mut calc_tag = [0u8; 32]; - hmac.raw_result(&mut calc_tag); - if crypto::util::fixed_time_eq(&calc_tag, &err_packet.hmac) { - const UNKNOWN_CHAN: u16 = 0x4000|10; - const TEMP_CHAN_FAILURE: u16 = 0x4000|7; - match byte_utils::slice_to_be16(&err_packet.failuremsg[0..2]) { - TEMP_CHAN_FAILURE => { - if err_packet.failuremsg.len() >= 4 { - let update_len = byte_utils::slice_to_be16(&err_packet.failuremsg[2..4]) as usize; - if err_packet.failuremsg.len() >= 4 + update_len { - if let Ok(chan_update) = msgs::ChannelUpdate::decode(&err_packet.failuremsg[4..4 + update_len]) { - res = Some(msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { - msg: chan_update, - }); - } + match htlc_source { + &HTLCSource::OutboundRoute { ref route, ref session_priv, .. } => { + // Handle packed channel/node updates for passing back for the route handler + let mut packet_decrypted = msg.reason.data.clone(); + let mut res = None; + Self::construct_onion_keys_callback(&self.secp_ctx, &route, &session_priv, |shared_secret, _, _, route_hop| { + if res.is_some() { return; } + + let ammag = ChannelManager::gen_ammag_from_shared_secret(&shared_secret); + + let mut decryption_tmp = Vec::with_capacity(packet_decrypted.len()); + decryption_tmp.resize(packet_decrypted.len(), 0); + let mut chacha = ChaCha20::new(&ammag, &[0u8; 8]); + chacha.process(&packet_decrypted, &mut decryption_tmp[..]); + packet_decrypted = decryption_tmp; + + if let Ok(err_packet) = msgs::DecodedOnionErrorPacket::decode(&packet_decrypted) { + if err_packet.failuremsg.len() >= 2 { + let um = ChannelManager::gen_um_from_shared_secret(&shared_secret); + + let mut hmac = Hmac::new(Sha256::new(), &um); + hmac.input(&err_packet.encode()[32..]); + let mut calc_tag = [0u8; 32]; + hmac.raw_result(&mut calc_tag); + if crypto::util::fixed_time_eq(&calc_tag, &err_packet.hmac) { + const UNKNOWN_CHAN: u16 = 0x4000|10; + const TEMP_CHAN_FAILURE: u16 = 0x4000|7; + match byte_utils::slice_to_be16(&err_packet.failuremsg[0..2]) { + TEMP_CHAN_FAILURE => { + if err_packet.failuremsg.len() >= 4 { + let update_len = byte_utils::slice_to_be16(&err_packet.failuremsg[2..4]) as usize; + if err_packet.failuremsg.len() >= 4 + update_len { + if let Ok(chan_update) = msgs::ChannelUpdate::decode(&err_packet.failuremsg[4..4 + update_len]) { + res = Some(msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { + msg: chan_update, + }); } } - }, - UNKNOWN_CHAN => { - // No such next-hop. We know this came from the - // current node as the HMAC validated. - res = Some(msgs::HTLCFailChannelUpdate::ChannelClosed { - short_channel_id: route_hop.short_channel_id - }); - }, - _ => {}, //TODO: Enumerate all of these! - } + } + }, + UNKNOWN_CHAN => { + // No such next-hop. We know this came from the + // current node as the HMAC validated. + res = Some(msgs::HTLCFailChannelUpdate::ChannelClosed { + short_channel_id: route_hop.short_channel_id + }); + }, + _ => {}, //TODO: Enumerate all of these! } } } - }).unwrap(); - Ok(res) - }, - _ => { Ok(None) }, - } - } else { - Ok(None) + } + }).unwrap(); + Ok(res) + }, + _ => { Ok(None) }, } } @@ -1823,7 +1768,8 @@ impl ChannelManager { //TODO: here and below MsgHandleErrInternal, #153 case return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.channel_id)); } - chan.update_fail_malformed_htlc(&msg, HTLCFailReason::Reason { failure_code: msg.failure_code, data: Vec::new() }).map_err(|e| MsgHandleErrInternal::from_maybe_close(e)) + chan.update_fail_malformed_htlc(&msg, HTLCFailReason::Reason { failure_code: msg.failure_code, data: Vec::new() }).map_err(|e| MsgHandleErrInternal::from_maybe_close(e))?; + Ok(()) }, None => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel", msg.channel_id)) } @@ -1851,7 +1797,7 @@ impl ChannelManager { } fn internal_revoke_and_ack(&self, their_node_id: &PublicKey, msg: &msgs::RevokeAndACK) -> Result, MsgHandleErrInternal> { - let (res, mut pending_forwards, mut pending_failures, chan_monitor) = { + let ((res, mut pending_forwards, mut pending_failures, chan_monitor), short_channel_id) = { let mut channel_state = self.channel_state.lock().unwrap(); match channel_state.by_id.get_mut(&msg.channel_id) { Some(chan) => { @@ -1859,7 +1805,7 @@ impl ChannelManager { //TODO: here and below MsgHandleErrInternal, #153 case return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.channel_id)); } - chan.revoke_and_ack(&msg).map_err(|e| MsgHandleErrInternal::from_maybe_close(e))? + (chan.revoke_and_ack(&msg).map_err(|e| MsgHandleErrInternal::from_maybe_close(e))?, chan.get_short_channel_id().expect("RAA should only work on a short-id-available channel")) }, None => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel", msg.channel_id)) } @@ -1868,7 +1814,7 @@ impl ChannelManager { unimplemented!(); } for failure in pending_failures.drain(..) { - self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), &failure.0, failure.1); + self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), failure.0, &failure.1, failure.2); } let mut forward_event = None; @@ -1878,13 +1824,13 @@ impl ChannelManager { forward_event = Some(Instant::now() + Duration::from_millis(((rng::rand_f32() * 4.0 + 1.0) * MIN_HTLC_RELAY_HOLDING_CELL_MILLIS as f32) as u64)); channel_state.next_forward = forward_event.unwrap(); } - for forward_info in pending_forwards.drain(..) { + for (forward_info, prev_htlc_id) in pending_forwards.drain(..) { match channel_state.forward_htlcs.entry(forward_info.short_channel_id) { hash_map::Entry::Occupied(mut entry) => { - entry.get_mut().push(forward_info); + entry.get_mut().push(HTLCForwardInfo { prev_short_channel_id: short_channel_id, prev_htlc_id, forward_info }); }, hash_map::Entry::Vacant(entry) => { - entry.insert(vec!(forward_info)); + entry.insert(vec!(HTLCForwardInfo { prev_short_channel_id: short_channel_id, prev_htlc_id, forward_info })); } } } -- 2.39.5