/// privacy-breaking recipient-probing attacks which may reveal payment activity to
/// motivated attackers.
///
+ /// Note that the privacy concerns in (b) are not relevant in payments with a payment_secret
+ /// set. Thus, for such payments we will claim any payments which do not under-pay.
+ ///
/// May panic if called except in response to a PaymentReceived event.
pub fn claim_funds(&self, payment_preimage: PaymentPreimage, payment_secret: &Option<PaymentSecret>, expected_amount: u64) -> bool {
let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&(payment_hash, *payment_secret));
if let Some(mut sources) = removed_source {
assert!(!sources.is_empty());
- let valid_mpp_amount = if let &Some(ref data) = &sources[0].payment_data {
+
+ // If we are claiming an MPP payment, we have to take special care to ensure that each
+ // channel exists before claiming all of the payments (inside one lock).
+ // Note that channel existance is sufficient as we should always get a monitor update
+ // which will take care of the real HTLC claim enforcement.
+ //
+ // If we find an HTLC which we would need to claim but for which we do not have a
+ // channel, we will fail all parts of the MPP payment. While we could wait and see if
+ // the sender retries the already-failed path(s), it should be a pretty rare case where
+ // we got all the HTLCs and then a channel closed while we were waiting for the user to
+ // provide the preimage, so worrying too much about the optimal handling isn't worth
+ // it.
+
+ let (is_mpp, mut valid_mpp) = if let &Some(ref data) = &sources[0].payment_data {
assert!(payment_secret.is_some());
- data.total_msat == expected_amount
+ (true, data.total_msat >= expected_amount)
} else {
assert!(payment_secret.is_none());
- false
+ (false, false)
};
+ for htlc in sources.iter() {
+ if !is_mpp || !valid_mpp { break; }
+ if let None = channel_state.as_ref().unwrap().short_to_id.get(&htlc.prev_hop.short_channel_id) {
+ valid_mpp = false;
+ }
+ }
+
+ let mut errs = Vec::new();
let mut claimed_any_htlcs = false;
for htlc in sources.drain(..) {
if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
- if !valid_mpp_amount && (htlc.value < expected_amount || htlc.value > expected_amount * 2) {
+ if (is_mpp && !valid_mpp) || (!is_mpp && (htlc.value < expected_amount || htlc.value > expected_amount * 2)) {
let mut htlc_msat_data = byte_utils::be64_to_array(htlc.value).to_vec();
let mut height_data = byte_utils::be32_to_array(self.latest_block_height.load(Ordering::Acquire) as u32).to_vec();
htlc_msat_data.append(&mut height_data);
HTLCSource::PreviousHopData(htlc.prev_hop), &payment_hash,
HTLCFailReason::Reason { failure_code: 0x4000|15, data: htlc_msat_data });
} else {
- self.claim_funds_internal(channel_state.take().unwrap(), HTLCSource::PreviousHopData(htlc.prev_hop), payment_preimage);
- claimed_any_htlcs = true;
+ match self.claim_funds_from_hop(channel_state.as_mut().unwrap(), htlc.prev_hop, payment_preimage) {
+ Err(Some(e)) => {
+ if let msgs::ErrorAction::IgnoreError = e.1.err.action {
+ // We got a temporary failure updating monitor, but will claim the
+ // HTLC when the monitor updating is restored (or on chain).
+ log_error!(self, "Temporary failure claiming HTLC, treating as success: {}", e.1.err.err);
+ claimed_any_htlcs = true;
+ } else { errs.push(e); }
+ },
+ Err(None) if is_mpp => unreachable!("We already checked for channel existence, we can't fail here!"),
+ Err(None) => {
+ log_warn!(self, "Channel we expected to claim an HTLC from was closed.");
+ },
+ Ok(()) => claimed_any_htlcs = true,
+ }
}
}
+
+ // Now that we've done the entire above loop in one lock, we can handle any errors
+ // which were generated.
+ channel_state.take();
+
+ for (their_node_id, err) in errs.drain(..) {
+ let res: Result<(), _> = Err(err);
+ let _ = handle_error!(self, res, their_node_id);
+ }
+
claimed_any_htlcs
} else { false }
}
- fn claim_funds_internal(&self, mut channel_state_lock: MutexGuard<ChannelHolder<ChanSigner>>, source: HTLCSource, payment_preimage: PaymentPreimage) {
- let (their_node_id, err) = loop {
- match source {
- HTLCSource::OutboundRoute { .. } => {
- mem::drop(channel_state_lock);
- let mut pending_events = self.pending_events.lock().unwrap();
- pending_events.push(events::Event::PaymentSent {
- payment_preimage
- });
- },
- HTLCSource::PreviousHopData(HTLCPreviousHopData { short_channel_id, htlc_id, .. }) => {
- //TODO: Delay the claimed_funds relaying just like we do outbound relay!
- let channel_state = &mut *channel_state_lock;
- 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 it's missing.
- return
- }
- };
+ fn claim_funds_from_hop(&self, channel_state_lock: &mut MutexGuard<ChannelHolder<ChanSigner>>, prev_hop: HTLCPreviousHopData, payment_preimage: PaymentPreimage) -> Result<(), Option<(PublicKey, MsgHandleErrInternal)>> {
+ //TODO: Delay the claimed_funds relaying just like we do outbound relay!
+ let channel_state = &mut **channel_state_lock;
+ let chan_id = match channel_state.short_to_id.get(&prev_hop.short_channel_id) {
+ Some(chan_id) => chan_id.clone(),
+ None => {
+ return Err(None)
+ }
+ };
- if let hash_map::Entry::Occupied(mut chan) = channel_state.by_id.entry(chan_id) {
- let was_frozen_for_monitor = chan.get().is_awaiting_monitor_update();
- match chan.get_mut().get_update_fulfill_htlc_and_commit(htlc_id, payment_preimage) {
- Ok((msgs, monitor_option)) => {
- if let Some(monitor_update) = monitor_option {
- if let Err(e) = self.monitor.update_monitor(chan.get().get_funding_txo().unwrap(), monitor_update) {
- if was_frozen_for_monitor {
- assert!(msgs.is_none());
- } else {
- break (chan.get().get_their_node_id(), handle_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, msgs.is_some()));
- }
- }
- }
- if let Some((msg, commitment_signed)) = msgs {
- channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
- node_id: chan.get().get_their_node_id(),
- updates: msgs::CommitmentUpdate {
- update_add_htlcs: Vec::new(),
- update_fulfill_htlcs: vec![msg],
- update_fail_htlcs: Vec::new(),
- update_fail_malformed_htlcs: Vec::new(),
- update_fee: None,
- commitment_signed,
- }
- });
- }
- },
- 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
- },
+ if let hash_map::Entry::Occupied(mut chan) = channel_state.by_id.entry(chan_id) {
+ let was_frozen_for_monitor = chan.get().is_awaiting_monitor_update();
+ match chan.get_mut().get_update_fulfill_htlc_and_commit(prev_hop.htlc_id, payment_preimage) {
+ Ok((msgs, monitor_option)) => {
+ if let Some(monitor_update) = monitor_option {
+ if let Err(e) = self.monitor.update_monitor(chan.get().get_funding_txo().unwrap(), monitor_update) {
+ if was_frozen_for_monitor {
+ assert!(msgs.is_none());
+ } else {
+ return Err(Some((chan.get().get_their_node_id(), handle_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, msgs.is_some()).unwrap_err())));
+ }
}
- } else { unreachable!(); }
+ }
+ if let Some((msg, commitment_signed)) = msgs {
+ channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
+ node_id: chan.get().get_their_node_id(),
+ updates: msgs::CommitmentUpdate {
+ update_add_htlcs: Vec::new(),
+ update_fulfill_htlcs: vec![msg],
+ update_fail_htlcs: Vec::new(),
+ update_fail_malformed_htlcs: Vec::new(),
+ update_fee: None,
+ commitment_signed,
+ }
+ });
+ }
+ return Ok(())
+ },
+ Err(e) => {
+ // TODO: Do something with e?
+ // This should only occur if we are claiming an HTLC at the same time as the
+ // HTLC is being failed (eg because a block is being connected and this caused
+ // an HTLC to time out). This should, of course, only occur if the user is the
+ // one doing the claiming (as it being a part of a peer claim would imply we're
+ // about to lose funds) and only if the lock in claim_funds was dropped as a
+ // previous HTLC was failed (thus not for an MPP payment).
+ debug_assert!(false, "This shouldn't be reachable except in absurdly rare cases between monitor updates and HTLC timeouts: {:?}", e);
+ return Err(None)
},
}
- return;
- };
+ } else { unreachable!(); }
+ }
- mem::drop(channel_state_lock);
- let _ = handle_error!(self, err, their_node_id);
+ fn claim_funds_internal(&self, mut channel_state_lock: MutexGuard<ChannelHolder<ChanSigner>>, source: HTLCSource, payment_preimage: PaymentPreimage) {
+ match source {
+ HTLCSource::OutboundRoute { .. } => {
+ mem::drop(channel_state_lock);
+ let mut pending_events = self.pending_events.lock().unwrap();
+ pending_events.push(events::Event::PaymentSent {
+ payment_preimage
+ });
+ },
+ HTLCSource::PreviousHopData(hop_data) => {
+ if let Err((their_node_id, err)) = match self.claim_funds_from_hop(&mut channel_state_lock, hop_data, payment_preimage) {
+ Ok(()) => Ok(()),
+ Err(None) => {
+ // TODO: There is probably a channel monitor somewhere that needs to
+ // learn the preimage as the channel already hit the chain and that's
+ // why it's missing.
+ Ok(())
+ },
+ Err(Some(res)) => Err(res),
+ } {
+ mem::drop(channel_state_lock);
+ let res: Result<(), _> = Err(err);
+ let _ = handle_error!(self, res, their_node_id);
+ }
+ },
+ }
}
/// Gets the node_id held by this ChannelManager
projects / rust-lightning / commitdiff