// 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).
+// Once said HTLC is committed in the Channel, if the PendingHTLCStatus indicated Forward, the
+// Channel will return the PendingHTLCInfo back to us, and we will create an HTLCForwardInfo
+// with it to track where it came from (in case of onwards-forward error), waiting a random delay
+// before we forward it.
+//
+// We will then use HTLCForwardInfo's PendingHTLCInfo 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.
-/// 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
+enum PendingForwardReceiveHTLCInfo {
+ Forward {
+ onion_packet: msgs::OnionPacket,
+ short_channel_id: u64, // This should be NonZero<u64> eventually
+ },
+ Receive {
+ payment_data: Option<msgs::FinalOnionHopData>,
+ },
+}
+
#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
-pub(super) struct PendingForwardHTLCInfo {
- onion_packet: Option<msgs::OnionPacket>,
+pub(super) struct PendingHTLCInfo {
+ type_data: PendingForwardReceiveHTLCInfo,
incoming_shared_secret: [u8; 32],
payment_hash: PaymentHash,
- short_channel_id: u64,
pub(super) amt_to_forward: u64,
pub(super) outgoing_cltv_value: u32,
}
/// Stores whether we can't forward an HTLC or relevant forwarding info
#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
pub(super) enum PendingHTLCStatus {
- Forward(PendingForwardHTLCInfo),
+ Forward(PendingHTLCInfo),
Fail(HTLCFailureMsg),
}
+pub(super) enum HTLCForwardInfo {
+ AddHTLC {
+ prev_short_channel_id: u64,
+ prev_htlc_id: u64,
+ forward_info: PendingHTLCInfo,
+ },
+ FailHTLC {
+ htlc_id: u64,
+ err_packet: msgs::OnionErrorPacket,
+ },
+}
+
/// Tracks the inbound corresponding to an outbound HTLC
#[derive(Clone, PartialEq)]
pub(super) struct HTLCPreviousHopData {
incoming_packet_shared_secret: [u8; 32],
}
+struct ClaimableHTLC {
+ src: HTLCPreviousHopData,
+ value: u64,
+ payment_data: Option<msgs::FinalOnionHopData>,
+}
+
/// Tracks the inbound corresponding to an outbound HTLC
#[derive(Clone, PartialEq)]
pub(super) enum HTLCSource {
/// second to 30 seconds, but people expect lightning to be, you know, kinda fast, sadly.
const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u64 = 100;
-pub(super) enum HTLCForwardInfo {
- AddHTLC {
- prev_short_channel_id: u64,
- prev_htlc_id: u64,
- forward_info: PendingForwardHTLCInfo,
- },
- FailHTLC {
- htlc_id: u64,
- err_packet: msgs::OnionErrorPacket,
- },
-}
-
/// For events which result in both a RevokeAndACK and a CommitmentUpdate, by default they should
/// be sent in the order they appear in the return value, however sometimes the order needs to be
/// variable at runtime (eg Channel::channel_reestablish needs to re-send messages in the order
/// short channel id -> forward infos. Key of 0 means payments received
/// Note that while this is held in the same mutex as the channels themselves, no consistency
/// guarantees are made about the existence of a channel with the short id here, nor the short
- /// ids in the PendingForwardHTLCInfo!
+ /// ids in the PendingHTLCInfo!
pub(super) forward_htlcs: HashMap<u64, Vec<HTLCForwardInfo>>,
- /// payment_hash -> Vec<(amount_received, htlc_source)> for tracking things that were to us and
- /// can be failed/claimed by the user
+ /// Tracks things that were to us and can be failed/claimed by the user
/// 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!
- pub(super) claimable_htlcs: HashMap<PaymentHash, Vec<(u64, HTLCPreviousHopData)>>,
+ claimable_htlcs: HashMap<PaymentHash, Vec<ClaimableHTLC>>,
/// Messages to send to peers - pushed to in the same lock that they are generated in (except
/// for broadcast messages, where ordering isn't as strict).
pub(super) pending_msg_events: Vec<events::MessageSendEvent>,
} else if $resend_commitment { "commitment" }
else if $resend_raa { "RAA" }
else { "nothing" },
- (&$failed_forwards as &Vec<(PendingForwardHTLCInfo, u64)>).len(),
+ (&$failed_forwards as &Vec<(PendingHTLCInfo, u64)>).len(),
(&$failed_fails as &Vec<(HTLCSource, PaymentHash, HTLCFailReason)>).len());
if !$resend_commitment {
debug_assert!($action_type == RAACommitmentOrder::RevokeAndACKFirst || !$resend_raa);
return_err!("Upstream node set CLTV to the wrong value", 18, &byte_utils::be32_to_array(msg.cltv_expiry));
}
+ let payment_data = match next_hop_data.format {
+ msgs::OnionHopDataFormat::Legacy { .. } => None,
+ msgs::OnionHopDataFormat::NonFinalNode { .. } => return_err!("Got non final data with an HMAC of 0", 0x4000 | 22, &[0;0]),
+ msgs::OnionHopDataFormat::FinalNode { payment_data } => payment_data,
+ };
+
// Note that we could obviously respond immediately with an update_fulfill_htlc
// message, however that would leak that we are the recipient of this payment, so
// instead we stay symmetric with the forwarding case, only responding (after a
// delay) once they've send us a commitment_signed!
- PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
- onion_packet: None,
+ PendingHTLCStatus::Forward(PendingHTLCInfo {
+ type_data: PendingForwardReceiveHTLCInfo::Receive { payment_data },
payment_hash: msg.payment_hash.clone(),
- short_channel_id: 0,
incoming_shared_secret: shared_secret,
amt_to_forward: next_hop_data.amt_to_forward,
outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
let short_channel_id = match next_hop_data.format {
msgs::OnionHopDataFormat::Legacy { short_channel_id } => short_channel_id,
msgs::OnionHopDataFormat::NonFinalNode { short_channel_id } => short_channel_id,
- msgs::OnionHopDataFormat::FinalNode => {
+ msgs::OnionHopDataFormat::FinalNode { .. } => {
return_err!("Final Node OnionHopData provided for us as an intermediary node", 0x4000 | 22, &[0;0]);
},
};
- PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
- onion_packet: Some(outgoing_packet),
+ PendingHTLCStatus::Forward(PendingHTLCInfo {
+ type_data: PendingForwardReceiveHTLCInfo::Forward {
+ onion_packet: outgoing_packet,
+ short_channel_id: short_channel_id,
+ },
payment_hash: msg.payment_hash.clone(),
- short_channel_id: short_channel_id,
incoming_shared_secret: shared_secret,
amt_to_forward: next_hop_data.amt_to_forward,
outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
};
channel_state = Some(self.channel_state.lock().unwrap());
- if let &PendingHTLCStatus::Forward(PendingForwardHTLCInfo { ref onion_packet, ref short_channel_id, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
- if onion_packet.is_some() { // If short_channel_id is 0 here, we'll reject them in the body here
+ if let &PendingHTLCStatus::Forward(PendingHTLCInfo { ref type_data, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
+ // If short_channel_id is 0 here, we'll reject them in the body here (which is
+ // important as various things later assume we are a ::Receive if short_channel_id is
+ // non-0.
+ if let &PendingForwardReceiveHTLCInfo::Forward { ref short_channel_id, .. } = type_data {
let id_option = channel_state.as_ref().unwrap().short_to_id.get(&short_channel_id).cloned();
let forwarding_id = match id_option {
None => { // unknown_next_peer
let mut fail_htlc_msgs = Vec::new();
for forward_info in pending_forwards.drain(..) {
match forward_info {
- HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
- log_trace!(self, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", log_bytes!(forward_info.payment_hash.0), prev_short_channel_id, short_chan_id);
+ HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
+ type_data: PendingForwardReceiveHTLCInfo::Forward {
+ onion_packet, ..
+ }, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value }, } => {
+ log_trace!(self, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", log_bytes!(payment_hash.0), prev_short_channel_id, short_chan_id);
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,
+ incoming_packet_shared_secret: incoming_shared_secret,
});
- match chan.get_mut().send_htlc(forward_info.amt_to_forward, forward_info.payment_hash, forward_info.outgoing_cltv_value, htlc_source.clone(), forward_info.onion_packet.unwrap()) {
+ match chan.get_mut().send_htlc(amt_to_forward, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet) {
Err(e) => {
if let ChannelError::Ignore(msg) = e {
- log_trace!(self, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(forward_info.payment_hash.0), msg);
+ log_trace!(self, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(payment_hash.0), msg);
} else {
panic!("Stated return value requirements in send_htlc() were not met");
}
let chan_update = self.get_channel_update(chan.get()).unwrap();
- failed_forwards.push((htlc_source, forward_info.payment_hash, 0x1000 | 7, Some(chan_update)));
+ failed_forwards.push((htlc_source, payment_hash, 0x1000 | 7, Some(chan_update)));
continue;
},
Ok(update_add) => {
}
}
},
+ HTLCForwardInfo::AddHTLC { .. } => {
+ panic!("short_channel_id != 0 should imply any pending_forward entries are of type Forward");
+ },
HTLCForwardInfo::FailHTLC { htlc_id, err_packet } => {
log_trace!(self, "Failing HTLC back to channel with short id {} after delay", short_chan_id);
match chan.get_mut().get_update_fail_htlc(htlc_id, err_packet) {
} else {
for forward_info in pending_forwards.drain(..) {
match forward_info {
- HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
+ HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
+ type_data: PendingForwardReceiveHTLCInfo::Receive { payment_data },
+ incoming_shared_secret, payment_hash, amt_to_forward, .. }, } => {
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((forward_info.amt_to_forward, prev_hop_data)),
- hash_map::Entry::Vacant(entry) => { entry.insert(vec![(forward_info.amt_to_forward, prev_hop_data)]); },
+ incoming_packet_shared_secret: incoming_shared_secret,
};
+ channel_state.claimable_htlcs.entry(payment_hash).or_insert(Vec::new()).push(ClaimableHTLC {
+ src: prev_hop_data,
+ value: amt_to_forward,
+ payment_data,
+ });
new_events.push(events::Event::PaymentReceived {
- payment_hash: forward_info.payment_hash,
- amt: forward_info.amt_to_forward,
+ payment_hash: payment_hash,
+ amt: amt_to_forward,
});
},
+ HTLCForwardInfo::AddHTLC { .. } => {
+ panic!("short_channel_id == 0 should imply any pending_forward entries are of type Receive");
+ },
HTLCForwardInfo::FailHTLC { .. } => {
panic!("Got pending fail of our own HTLC");
}
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 (recvd_value, htlc_with_hash) in sources.drain(..) {
+ for htlc 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: byte_utils::be64_to_array(recvd_value).to_vec() });
+ HTLCSource::PreviousHopData(htlc.src), payment_hash,
+ HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: byte_utils::be64_to_array(htlc.value).to_vec() });
}
true
} else { 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 (received_amount, htlc_with_hash) in sources.drain(..) {
+ for htlc in sources.drain(..) {
if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
- if received_amount < expected_amount || received_amount > expected_amount * 2 {
- let mut htlc_msat_data = byte_utils::be64_to_array(received_amount).to_vec();
+ if 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);
self.fail_htlc_backwards_internal(channel_state.take().unwrap(),
- HTLCSource::PreviousHopData(htlc_with_hash), &payment_hash,
+ HTLCSource::PreviousHopData(htlc.src), &payment_hash,
HTLCFailReason::Reason { failure_code: 0x4000|15, data: htlc_msat_data });
} else {
- self.claim_funds_internal(channel_state.take().unwrap(), HTLCSource::PreviousHopData(htlc_with_hash), payment_preimage);
+ self.claim_funds_internal(channel_state.take().unwrap(), HTLCSource::PreviousHopData(htlc.src), payment_preimage);
}
}
true
// If the update_add is completely bogus, the call will Err and we will close,
// but if we've sent a shutdown and they haven't acknowledged it yet, we just
// want to reject the new HTLC and fail it backwards instead of forwarding.
- if let PendingHTLCStatus::Forward(PendingForwardHTLCInfo { incoming_shared_secret, .. }) = pending_forward_info {
+ if let PendingHTLCStatus::Forward(PendingHTLCInfo { incoming_shared_secret, .. }) = pending_forward_info {
let chan_update = self.get_channel_update(chan.get());
pending_forward_info = PendingHTLCStatus::Fail(HTLCFailureMsg::Relay(msgs::UpdateFailHTLC {
channel_id: msg.channel_id,
}
#[inline]
- fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, Vec<(PendingForwardHTLCInfo, u64)>)]) {
+ fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, Vec<(PendingHTLCInfo, u64)>)]) {
for &mut (prev_short_channel_id, ref mut pending_forwards) in per_source_pending_forwards {
let mut forward_event = None;
if !pending_forwards.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 channel_state.forward_htlcs.entry(forward_info.short_channel_id) {
+ match channel_state.forward_htlcs.entry(match forward_info.type_data {
+ PendingForwardReceiveHTLCInfo::Forward { short_channel_id, .. } => short_channel_id,
+ PendingForwardReceiveHTLCInfo::Receive { .. } => 0,
+ }) {
hash_map::Entry::Occupied(mut entry) => {
entry.get_mut().push(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info });
},
const SERIALIZATION_VERSION: u8 = 1;
const MIN_SERIALIZATION_VERSION: u8 = 1;
-impl Writeable for PendingForwardHTLCInfo {
+impl Writeable for PendingHTLCInfo {
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
- self.onion_packet.write(writer)?;
+ match &self.type_data {
+ &PendingForwardReceiveHTLCInfo::Forward { ref onion_packet, ref short_channel_id } => {
+ 0u8.write(writer)?;
+ onion_packet.write(writer)?;
+ short_channel_id.write(writer)?;
+ },
+ &PendingForwardReceiveHTLCInfo::Receive { ref payment_data } => {
+ 1u8.write(writer)?;
+ payment_data.write(writer)?;
+ },
+ }
self.incoming_shared_secret.write(writer)?;
self.payment_hash.write(writer)?;
- self.short_channel_id.write(writer)?;
self.amt_to_forward.write(writer)?;
self.outgoing_cltv_value.write(writer)?;
Ok(())
}
}
-impl<R: ::std::io::Read> Readable<R> for PendingForwardHTLCInfo {
- fn read(reader: &mut R) -> Result<PendingForwardHTLCInfo, DecodeError> {
- Ok(PendingForwardHTLCInfo {
- onion_packet: Readable::read(reader)?,
+impl<R: ::std::io::Read> Readable<R> for PendingHTLCInfo {
+ fn read(reader: &mut R) -> Result<PendingHTLCInfo, DecodeError> {
+ Ok(PendingHTLCInfo {
+ type_data: match Readable::read(reader)? {
+ 0u8 => PendingForwardReceiveHTLCInfo::Forward {
+ onion_packet: Readable::read(reader)?,
+ short_channel_id: Readable::read(reader)?,
+ },
+ 1u8 => PendingForwardReceiveHTLCInfo::Receive {
+ payment_data: Readable::read(reader)?,
+ },
+ _ => return Err(DecodeError::InvalidValue),
+ },
incoming_shared_secret: Readable::read(reader)?,
payment_hash: Readable::read(reader)?,
- short_channel_id: Readable::read(reader)?,
amt_to_forward: Readable::read(reader)?,
outgoing_cltv_value: Readable::read(reader)?,
})
for (payment_hash, previous_hops) in channel_state.claimable_htlcs.iter() {
payment_hash.write(writer)?;
(previous_hops.len() as u64).write(writer)?;
- for &(recvd_amt, ref previous_hop) in previous_hops.iter() {
- recvd_amt.write(writer)?;
- previous_hop.write(writer)?;
+ for htlc in previous_hops.iter() {
+ htlc.src.write(writer)?;
+ htlc.value.write(writer)?;
+ htlc.payment_data.write(writer)?;
}
}
let previous_hops_len: u64 = Readable::read(reader)?;
let mut previous_hops = Vec::with_capacity(cmp::min(previous_hops_len as usize, 2));
for _ in 0..previous_hops_len {
- previous_hops.push((Readable::read(reader)?, Readable::read(reader)?));
+ previous_hops.push(ClaimableHTLC {
+ src: Readable::read(reader)?,
+ value: Readable::read(reader)?,
+ payment_data: Readable::read(reader)?,
+ });
}
claimable_htlcs.insert(payment_hash, previous_hops);
}