Clarify the in-flight HTLC state-tracking structs a bit.
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 12ac136af0a7c7aa468904cb7cfd6da8c0f559a5..b73f8667073bac64abdb11fd9e2f7e81fbb07c7e 100644 (file)
@@ -30,7 +30,7 @@ use chain::transaction::OutPoint;
 use ln::channel::{Channel, ChannelError};
 use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, ManyChannelMonitor, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY};
 use ln::router::Route;
-use ln::features::InitFeatures;
+use ln::features::{InitFeatures, NodeFeatures};
 use ln::msgs;
 use ln::onion_utils;
 use ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
@@ -57,15 +57,19 @@ use std::ops::Deref;
 // 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
-pub(super) struct PendingForwardHTLCInfo {
+pub(super) struct PendingHTLCInfo {
        onion_packet: Option<msgs::OnionPacket>,
        incoming_shared_secret: [u8; 32],
        payment_hash: PaymentHash,
@@ -83,10 +87,22 @@ pub(super) enum HTLCFailureMsg {
 /// 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 {
@@ -231,18 +247,6 @@ impl MsgHandleErrInternal {
 /// 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
@@ -262,7 +266,7 @@ pub(super) struct ChannelHolder<ChanSigner: ChannelKeys> {
        /// 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
@@ -355,6 +359,8 @@ pub struct ChannelManager<ChanSigner: ChannelKeys, M: Deref> where M::Target: Ma
        channel_state: Mutex<ChannelHolder<ChanSigner>>,
        our_network_key: SecretKey,
 
+       last_node_announcement_serial: AtomicUsize,
+
        /// The bulk of our storage will eventually be here (channels and message queues and the like).
        /// If we are connected to a peer we always at least have an entry here, even if no channels
        /// are currently open with that peer.
@@ -571,7 +577,7 @@ macro_rules! handle_monitor_err {
                                                        } 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);
@@ -649,6 +655,8 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                        }),
                        our_network_key: keys_manager.get_node_secret(),
 
+                       last_node_announcement_serial: AtomicUsize::new(0),
+
                        per_peer_state: RwLock::new(HashMap::new()),
 
                        pending_events: Mutex::new(Vec::new()),
@@ -963,7 +971,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                // instead we stay symmetric with the forwarding case, only responding (after a
                                // delay) once they've send us a commitment_signed!
 
-                               PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
+                               PendingHTLCStatus::Forward(PendingHTLCInfo {
                                        onion_packet: None,
                                        payment_hash: msg.payment_hash.clone(),
                                        short_channel_id: 0,
@@ -1015,7 +1023,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                        },
                                };
 
-                               PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
+                               PendingHTLCStatus::Forward(PendingHTLCInfo {
                                        onion_packet: Some(outgoing_packet),
                                        payment_hash: msg.payment_hash.clone(),
                                        short_channel_id: short_channel_id,
@@ -1026,7 +1034,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                        };
 
                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 let &PendingHTLCStatus::Forward(PendingHTLCInfo { 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
                                let id_option = channel_state.as_ref().unwrap().short_to_id.get(&short_channel_id).cloned();
                                let forwarding_id = match id_option {
@@ -1163,6 +1171,9 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                let onion_keys = secp_call!(onion_utils::construct_onion_keys(&self.secp_ctx, &route, &session_priv),
                                APIError::RouteError{err: "Pubkey along hop was maliciously selected"});
                let (onion_payloads, htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(&route, cur_height)?;
+               if onion_utils::route_size_insane(&onion_payloads) {
+                       return Err(APIError::RouteError{err: "Route had too large size once"});
+               }
                let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, prng_seed, &payment_hash);
 
                let _ = self.total_consistency_lock.read().unwrap();
@@ -1311,6 +1322,37 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                })
        }
 
+       /// Generates a signed node_announcement from the given arguments and creates a
+       /// BroadcastNodeAnnouncement event.
+       ///
+       /// RGB is a node "color" and alias a printable human-readable string to describe this node to
+       /// humans. They carry no in-protocol meaning.
+       ///
+       /// addresses represent the set (possibly empty) of socket addresses on which this node accepts
+       /// incoming connections.
+       pub fn broadcast_node_announcement(&self, rgb: [u8; 3], alias: [u8; 32], addresses: msgs::NetAddressSet) {
+               let _ = self.total_consistency_lock.read().unwrap();
+
+               let announcement = msgs::UnsignedNodeAnnouncement {
+                       features: NodeFeatures::supported(),
+                       timestamp: self.last_node_announcement_serial.fetch_add(1, Ordering::AcqRel) as u32,
+                       node_id: self.get_our_node_id(),
+                       rgb, alias,
+                       addresses: addresses.to_vec(),
+                       excess_address_data: Vec::new(),
+                       excess_data: Vec::new(),
+               };
+               let msghash = hash_to_message!(&Sha256dHash::hash(&announcement.encode()[..])[..]);
+
+               let mut channel_state = self.channel_state.lock().unwrap();
+               channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastNodeAnnouncement {
+                       msg: msgs::NodeAnnouncement {
+                               signature: self.secp_ctx.sign(&msghash, &self.our_network_key),
+                               contents: announcement
+                       },
+               });
+       }
+
        /// Processes HTLCs which are pending waiting on random forward delay.
        ///
        /// Should only really ever be called in response to a PendingHTLCsForwardable event.
@@ -2145,7 +2187,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                        // 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,
@@ -2275,7 +2317,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
        }
 
        #[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() {
@@ -2906,6 +2948,7 @@ impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send> ChannelMessageHandler for
                                        &events::MessageSendEvent::SendShutdown { ref node_id, .. } => node_id != their_node_id,
                                        &events::MessageSendEvent::SendChannelReestablish { ref node_id, .. } => node_id != their_node_id,
                                        &events::MessageSendEvent::BroadcastChannelAnnouncement { .. } => true,
+                                       &events::MessageSendEvent::BroadcastNodeAnnouncement { .. } => true,
                                        &events::MessageSendEvent::BroadcastChannelUpdate { .. } => true,
                                        &events::MessageSendEvent::HandleError { ref node_id, .. } => node_id != their_node_id,
                                        &events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => true,
@@ -2986,7 +3029,7 @@ impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send> ChannelMessageHandler for
 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)?;
                self.incoming_shared_secret.write(writer)?;
@@ -2998,9 +3041,9 @@ impl Writeable for PendingForwardHTLCInfo {
        }
 }
 
-impl<R: ::std::io::Read> Readable<R> for PendingForwardHTLCInfo {
-       fn read(reader: &mut R) -> Result<PendingForwardHTLCInfo, DecodeError> {
-               Ok(PendingForwardHTLCInfo {
+impl<R: ::std::io::Read> Readable<R> for PendingHTLCInfo {
+       fn read(reader: &mut R) -> Result<PendingHTLCInfo, DecodeError> {
+               Ok(PendingHTLCInfo {
                        onion_packet: Readable::read(reader)?,
                        incoming_shared_secret: Readable::read(reader)?,
                        payment_hash: Readable::read(reader)?,
@@ -3219,6 +3262,8 @@ impl<ChanSigner: ChannelKeys + Writeable, M: Deref> Writeable for ChannelManager
                        peer_state.latest_features.write(writer)?;
                }
 
+               (self.last_node_announcement_serial.load(Ordering::Acquire) as u32).write(writer)?;
+
                Ok(())
        }
 }
@@ -3362,6 +3407,8 @@ impl<'a, R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>, M: Deref> R
                        per_peer_state.insert(peer_pubkey, Mutex::new(peer_state));
                }
 
+               let last_node_announcement_serial: u32 = Readable::read(reader)?;
+
                let channel_manager = ChannelManager {
                        genesis_hash,
                        fee_estimator: args.fee_estimator,
@@ -3381,6 +3428,8 @@ impl<'a, R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>, M: Deref> R
                        }),
                        our_network_key: args.keys_manager.get_node_secret(),
 
+                       last_node_announcement_serial: AtomicUsize::new(last_node_announcement_serial as usize),
+
                        per_peer_state: RwLock::new(per_peer_state),
 
                        pending_events: Mutex::new(Vec::new()),