Merge pull request #2441 from arik-so/2023-07-taproot-signer-wrapped
[rust-lightning] / lightning / src / ln / peer_handler.rs
index 2fcfb713c23f5105762c48c3e42062aacb6960b0..1a39bbb3ae408e7047159e6d9f3f63267188b61f 100644 (file)
@@ -15,6 +15,7 @@
 //! call into the provided message handlers (probably a ChannelManager and P2PGossipSync) with
 //! messages they should handle, and encoding/sending response messages.
 
+use bitcoin::blockdata::constants::ChainHash;
 use bitcoin::secp256k1::{self, Secp256k1, SecretKey, PublicKey};
 
 use crate::sign::{KeysManager, NodeSigner, Recipient};
@@ -26,11 +27,12 @@ use crate::ln::channelmanager::{SimpleArcChannelManager, SimpleRefChannelManager
 use crate::util::ser::{VecWriter, Writeable, Writer};
 use crate::ln::peer_channel_encryptor::{PeerChannelEncryptor,NextNoiseStep};
 use crate::ln::wire;
-use crate::ln::wire::Encode;
-use crate::onion_message::{CustomOnionMessageContents, CustomOnionMessageHandler, SimpleArcOnionMessenger, SimpleRefOnionMessenger};
+use crate::ln::wire::{Encode, Type};
+use crate::onion_message::{CustomOnionMessageContents, CustomOnionMessageHandler, OffersMessage, OffersMessageHandler, SimpleArcOnionMessenger, SimpleRefOnionMessenger};
 use crate::routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, NodeAlias};
 use crate::util::atomic_counter::AtomicCounter;
 use crate::util::logger::Logger;
+use crate::util::string::PrintableString;
 
 use crate::prelude::*;
 use crate::io;
@@ -64,6 +66,20 @@ pub trait CustomMessageHandler: wire::CustomMessageReader {
        /// in the process. Each message is paired with the node id of the intended recipient. If no
        /// connection to the node exists, then the message is simply not sent.
        fn get_and_clear_pending_msg(&self) -> Vec<(PublicKey, Self::CustomMessage)>;
+
+       /// Gets the node feature flags which this handler itself supports. All available handlers are
+       /// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
+       /// which are broadcasted in our [`NodeAnnouncement`] message.
+       ///
+       /// [`NodeAnnouncement`]: crate::ln::msgs::NodeAnnouncement
+       fn provided_node_features(&self) -> NodeFeatures;
+
+       /// Gets the init feature flags which should be sent to the given peer. All available handlers
+       /// are queried similarly and their feature flags are OR'd together to form the [`InitFeatures`]
+       /// which are sent in our [`Init`] message.
+       ///
+       /// [`Init`]: crate::ln::msgs::Init
+       fn provided_init_features(&self, their_node_id: &PublicKey) -> InitFeatures;
 }
 
 /// A dummy struct which implements `RoutingMessageHandler` without storing any routing information
@@ -102,9 +118,12 @@ impl OnionMessageHandler for IgnoringMessageHandler {
                InitFeatures::empty()
        }
 }
+impl OffersMessageHandler for IgnoringMessageHandler {
+       fn handle_message(&self, _msg: OffersMessage) -> Option<OffersMessage> { None }
+}
 impl CustomOnionMessageHandler for IgnoringMessageHandler {
        type CustomMessage = Infallible;
-       fn handle_custom_message(&self, _msg: Infallible) {
+       fn handle_custom_message(&self, _msg: Infallible) -> Option<Infallible> {
                // Since we always return `None` in the read the handle method should never be called.
                unreachable!();
        }
@@ -149,6 +168,12 @@ impl CustomMessageHandler for IgnoringMessageHandler {
        }
 
        fn get_and_clear_pending_msg(&self) -> Vec<(PublicKey, Self::CustomMessage)> { Vec::new() }
+
+       fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
+
+       fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures {
+               InitFeatures::empty()
+       }
 }
 
 /// A dummy struct which implements `ChannelMessageHandler` without having any channels.
@@ -253,6 +278,13 @@ impl ChannelMessageHandler for ErroringMessageHandler {
                features
        }
 
+       fn get_genesis_hashes(&self) -> Option<Vec<ChainHash>> {
+               // We don't enforce any chains upon peer connection for `ErroringMessageHandler` and leave it up
+               // to users of `ErroringMessageHandler` to make decisions on network compatiblility.
+               // There's not really any way to pull in specific networks here, and hardcoding can cause breakages.
+               None
+       }
+
        fn handle_open_channel_v2(&self, their_node_id: &PublicKey, msg: &msgs::OpenChannelV2) {
                ErroringMessageHandler::push_error(self, their_node_id, msg.temporary_channel_id);
        }
@@ -575,7 +607,15 @@ impl Peer {
 /// issues such as overly long function definitions.
 ///
 /// This is not exported to bindings users as `Arc`s don't make sense in bindings.
-pub type SimpleArcPeerManager<SD, M, T, F, C, L> = PeerManager<SD, Arc<SimpleArcChannelManager<M, T, F, L>>, Arc<P2PGossipSync<Arc<NetworkGraph<Arc<L>>>, Arc<C>, Arc<L>>>, Arc<SimpleArcOnionMessenger<L>>, Arc<L>, IgnoringMessageHandler, Arc<KeysManager>>;
+pub type SimpleArcPeerManager<SD, M, T, F, C, L> = PeerManager<
+       SD,
+       Arc<SimpleArcChannelManager<M, T, F, L>>,
+       Arc<P2PGossipSync<Arc<NetworkGraph<Arc<L>>>, Arc<C>, Arc<L>>>,
+       Arc<SimpleArcOnionMessenger<L>>,
+       Arc<L>,
+       IgnoringMessageHandler,
+       Arc<KeysManager>
+>;
 
 /// SimpleRefPeerManager is a type alias for a PeerManager reference, and is the reference
 /// counterpart to the SimpleArcPeerManager type alias. Use this type by default when you don't
@@ -585,12 +625,25 @@ pub type SimpleArcPeerManager<SD, M, T, F, C, L> = PeerManager<SD, Arc<SimpleArc
 /// helps with issues such as long function definitions.
 ///
 /// This is not exported to bindings users as general type aliases don't make sense in bindings.
-pub type SimpleRefPeerManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, 'i, 'j, 'k, 'l, 'm, SD, M, T, F, C, L> = PeerManager<SD, SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'm, M, T, F, L>, &'f P2PGossipSync<&'g NetworkGraph<&'f L>, &'h C, &'f L>, &'i SimpleRefOnionMessenger<'j, 'k, L>, &'f L, IgnoringMessageHandler, &'c KeysManager>;
+pub type SimpleRefPeerManager<
+       'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, 'i, 'j, 'k, 'l, 'm, 'n, SD, M, T, F, C, L
+> = PeerManager<
+       SD,
+       &'n SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'm, M, T, F, L>,
+       &'f P2PGossipSync<&'g NetworkGraph<&'f L>, &'h C, &'f L>,
+       &'i SimpleRefOnionMessenger<'g, 'm, 'n, L>,
+       &'f L,
+       IgnoringMessageHandler,
+       &'c KeysManager
+>;
 
 
 /// A generic trait which is implemented for all [`PeerManager`]s. This makes bounding functions or
 /// structs on any [`PeerManager`] much simpler as only this trait is needed as a bound, rather
 /// than the full set of bounds on [`PeerManager`] itself.
+///
+/// This is not exported to bindings users as general cover traits aren't useful in other
+/// languages.
 #[allow(missing_docs)]
 pub trait APeerManager {
        type Descriptor: SocketDescriptor;
@@ -897,6 +950,13 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                SecretKey::from_slice(&Sha256::from_engine(ephemeral_hash).into_inner()).expect("You broke SHA-256!")
        }
 
+       fn init_features(&self, their_node_id: &PublicKey) -> InitFeatures {
+               self.message_handler.chan_handler.provided_init_features(their_node_id)
+                       | self.message_handler.route_handler.provided_init_features(their_node_id)
+                       | self.message_handler.onion_message_handler.provided_init_features(their_node_id)
+                       | self.message_handler.custom_message_handler.provided_init_features(their_node_id)
+       }
+
        /// Indicates a new outbound connection has been established to a node with the given `node_id`
        /// and an optional remote network address.
        ///
@@ -1203,8 +1263,21 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                                                                Ok(x) => x,
                                                                Err(e) => {
                                                                        match e.action {
-                                                                               msgs::ErrorAction::DisconnectPeer { msg: _ } => {
-                                                                                       //TODO: Try to push msg
+                                                                               msgs::ErrorAction::DisconnectPeer { .. } => {
+                                                                                       // We may have an `ErrorMessage` to send to the peer,
+                                                                                       // but writing to the socket while reading can lead to
+                                                                                       // re-entrant code and possibly unexpected behavior. The
+                                                                                       // message send is optimistic anyway, and in this case
+                                                                                       // we immediately disconnect the peer.
+                                                                                       log_debug!(self.logger, "Error handling message{}; disconnecting peer with: {}", OptionalFromDebugger(&peer_node_id), e.err);
+                                                                                       return Err(PeerHandleError { });
+                                                                               },
+                                                                               msgs::ErrorAction::DisconnectPeerWithWarning { .. } => {
+                                                                                       // We have a `WarningMessage` to send to the peer, but
+                                                                                       // writing to the socket while reading can lead to
+                                                                                       // re-entrant code and possibly unexpected behavior. The
+                                                                                       // message send is optimistic anyway, and in this case
+                                                                                       // we immediately disconnect the peer.
                                                                                        log_debug!(self.logger, "Error handling message{}; disconnecting peer with: {}", OptionalFromDebugger(&peer_node_id), e.err);
                                                                                        return Err(PeerHandleError { });
                                                                                },
@@ -1292,10 +1365,9 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 
                                                                peer.set_their_node_id(their_node_id);
                                                                insert_node_id!();
-                                                               let features = self.message_handler.chan_handler.provided_init_features(&their_node_id)
-                                                                       .or(self.message_handler.route_handler.provided_init_features(&their_node_id))
-                                                                       .or(self.message_handler.onion_message_handler.provided_init_features(&their_node_id));
-                                                               let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
+                                                               let features = self.init_features(&their_node_id);
+                                                               let networks = self.message_handler.chan_handler.get_genesis_hashes();
+                                                               let resp = msgs::Init { features, networks, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
                                                                self.enqueue_message(peer, &resp);
                                                                peer.awaiting_pong_timer_tick_intervals = 0;
                                                        },
@@ -1306,10 +1378,9 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                                                                peer.pending_read_is_header = true;
                                                                peer.set_their_node_id(their_node_id);
                                                                insert_node_id!();
-                                                               let features = self.message_handler.chan_handler.provided_init_features(&their_node_id)
-                                                                       .or(self.message_handler.route_handler.provided_init_features(&their_node_id))
-                                                                       .or(self.message_handler.onion_message_handler.provided_init_features(&their_node_id));
-                                                               let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
+                                                               let features = self.init_features(&their_node_id);
+                                                               let networks = self.message_handler.chan_handler.get_genesis_hashes();
+                                                               let resp = msgs::Init { features, networks, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
                                                                self.enqueue_message(peer, &resp);
                                                                peer.awaiting_pong_timer_tick_intervals = 0;
                                                        },
@@ -1339,7 +1410,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                                                                                Ok(x) => x,
                                                                                Err(e) => {
                                                                                        match e {
-                                                                                               // Note that to avoid recursion we never call
+                                                                                               // Note that to avoid re-entrancy we never call
                                                                                                // `do_attempt_write_data` from here, causing
                                                                                                // the messages enqueued here to not actually
                                                                                                // be sent before the peer is disconnected.
@@ -1360,9 +1431,8 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                                                                                                        });
                                                                                                        continue;
                                                                                                }
-                                                                                               (msgs::DecodeError::UnknownRequiredFeature, ty) => {
-                                                                                                       log_gossip!(self.logger, "Received a message with an unknown required feature flag or TLV, you may want to update!");
-                                                                                                       self.enqueue_message(peer, &msgs::WarningMessage { channel_id: [0; 32], data: format!("Received an unknown required feature/TLV in message type {:?}", ty) });
+                                                                                               (msgs::DecodeError::UnknownRequiredFeature, _) => {
+                                                                                                       log_debug!(self.logger, "Received a message with an unknown required feature flag or TLV, you may want to update!");
                                                                                                        return Err(PeerHandleError { });
                                                                                                }
                                                                                                (msgs::DecodeError::UnknownVersion, _) => return Err(PeerHandleError { }),
@@ -1425,10 +1495,36 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 
                // Need an Init as first message
                if let wire::Message::Init(msg) = message {
-                       if msg.features.requires_unknown_bits() {
-                               log_debug!(self.logger, "Peer features required unknown version bits");
+                       // Check if we have any compatible chains if the `networks` field is specified.
+                       if let Some(networks) = &msg.networks {
+                               if let Some(our_chains) = self.message_handler.chan_handler.get_genesis_hashes() {
+                                       let mut have_compatible_chains = false;
+                                       'our_chains: for our_chain in our_chains.iter() {
+                                               for their_chain in networks {
+                                                       if our_chain == their_chain {
+                                                               have_compatible_chains = true;
+                                                               break 'our_chains;
+                                                       }
+                                               }
+                                       }
+                                       if !have_compatible_chains {
+                                               log_debug!(self.logger, "Peer does not support any of our supported chains");
+                                               return Err(PeerHandleError { }.into());
+                                       }
+                               }
+                       }
+
+                       let our_features = self.init_features(&their_node_id);
+                       if msg.features.requires_unknown_bits_from(&our_features) {
+                               log_debug!(self.logger, "Peer requires features unknown to us");
+                               return Err(PeerHandleError { }.into());
+                       }
+
+                       if our_features.requires_unknown_bits_from(&msg.features) {
+                               log_debug!(self.logger, "We require features unknown to our peer");
                                return Err(PeerHandleError { }.into());
                        }
+
                        if peer_lock.their_features.is_some() {
                                return Err(PeerHandleError { }.into());
                        }
@@ -1494,38 +1590,14 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                                // Handled above
                        },
                        wire::Message::Error(msg) => {
-                               let mut data_is_printable = true;
-                               for b in msg.data.bytes() {
-                                       if b < 32 || b > 126 {
-                                               data_is_printable = false;
-                                               break;
-                                       }
-                               }
-
-                               if data_is_printable {
-                                       log_debug!(self.logger, "Got Err message from {}: {}", log_pubkey!(their_node_id), msg.data);
-                               } else {
-                                       log_debug!(self.logger, "Got Err message from {} with non-ASCII error message", log_pubkey!(their_node_id));
-                               }
+                               log_debug!(self.logger, "Got Err message from {}: {}", log_pubkey!(their_node_id), PrintableString(&msg.data));
                                self.message_handler.chan_handler.handle_error(&their_node_id, &msg);
                                if msg.channel_id == [0; 32] {
                                        return Err(PeerHandleError { }.into());
                                }
                        },
                        wire::Message::Warning(msg) => {
-                               let mut data_is_printable = true;
-                               for b in msg.data.bytes() {
-                                       if b < 32 || b > 126 {
-                                               data_is_printable = false;
-                                               break;
-                                       }
-                               }
-
-                               if data_is_printable {
-                                       log_debug!(self.logger, "Got warning message from {}: {}", log_pubkey!(their_node_id), msg.data);
-                               } else {
-                                       log_debug!(self.logger, "Got warning message from {} with non-ASCII error message", log_pubkey!(their_node_id));
-                               }
+                               log_debug!(self.logger, "Got warning message from {}: {}", log_pubkey!(their_node_id), PrintableString(&msg.data));
                        },
 
                        wire::Message::Ping(msg) => {
@@ -2035,32 +2107,48 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                                                                        log_pubkey!(node_id), msg.contents.short_channel_id);
                                                        self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                                },
-                                               MessageSendEvent::HandleError { ref node_id, ref action } => {
-                                                       match *action {
-                                                               msgs::ErrorAction::DisconnectPeer { ref msg } => {
+                                               MessageSendEvent::HandleError { node_id, action } => {
+                                                       match action {
+                                                               msgs::ErrorAction::DisconnectPeer { msg } => {
+                                                                       if let Some(msg) = msg.as_ref() {
+                                                                               log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with message {}",
+                                                                                       log_pubkey!(node_id), msg.data);
+                                                                       } else {
+                                                                               log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {}",
+                                                                                       log_pubkey!(node_id));
+                                                                       }
                                                                        // We do not have the peers write lock, so we just store that we're
                                                                        // about to disconenct the peer and do it after we finish
                                                                        // processing most messages.
-                                                                       peers_to_disconnect.insert(*node_id, msg.clone());
+                                                                       let msg = msg.map(|msg| wire::Message::<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>::Error(msg));
+                                                                       peers_to_disconnect.insert(node_id, msg);
+                                                               },
+                                                               msgs::ErrorAction::DisconnectPeerWithWarning { msg } => {
+                                                                       log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with message {}",
+                                                                               log_pubkey!(node_id), msg.data);
+                                                                       // We do not have the peers write lock, so we just store that we're
+                                                                       // about to disconenct the peer and do it after we finish
+                                                                       // processing most messages.
+                                                                       peers_to_disconnect.insert(node_id, Some(wire::Message::Warning(msg)));
                                                                },
                                                                msgs::ErrorAction::IgnoreAndLog(level) => {
                                                                        log_given_level!(self.logger, level, "Received a HandleError event to be ignored for node {}", log_pubkey!(node_id));
                                                                },
                                                                msgs::ErrorAction::IgnoreDuplicateGossip => {},
                                                                msgs::ErrorAction::IgnoreError => {
-                                                                       log_debug!(self.logger, "Received a HandleError event to be ignored for node {}", log_pubkey!(node_id));
-                                                               },
+                                                                               log_debug!(self.logger, "Received a HandleError event to be ignored for node {}", log_pubkey!(node_id));
+                                                                       },
                                                                msgs::ErrorAction::SendErrorMessage { ref msg } => {
                                                                        log_trace!(self.logger, "Handling SendErrorMessage HandleError event in peer_handler for node {} with message {}",
                                                                                        log_pubkey!(node_id),
                                                                                        msg.data);
-                                                                       self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
+                                                                       self.enqueue_message(&mut *get_peer_for_forwarding!(&node_id), msg);
                                                                },
                                                                msgs::ErrorAction::SendWarningMessage { ref msg, ref log_level } => {
                                                                        log_given_level!(self.logger, *log_level, "Handling SendWarningMessage HandleError event in peer_handler for node {} with message {}",
                                                                                        log_pubkey!(node_id),
                                                                                        msg.data);
-                                                                       self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
+                                                                       self.enqueue_message(&mut *get_peer_for_forwarding!(&node_id), msg);
                                                                },
                                                        }
                                                },
@@ -2110,9 +2198,6 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                                                if let Some(peer_mutex) = peers.remove(&descriptor) {
                                                        let mut peer = peer_mutex.lock().unwrap();
                                                        if let Some(msg) = msg {
-                                                               log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with message {}",
-                                                                               log_pubkey!(node_id),
-                                                                               msg.data);
                                                                self.enqueue_message(&mut *peer, &msg);
                                                                // This isn't guaranteed to work, but if there is enough free
                                                                // room in the send buffer, put the error message there...
@@ -2345,8 +2430,9 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
                addresses.sort_by_key(|addr| addr.get_id());
 
                let features = self.message_handler.chan_handler.provided_node_features()
-                       .or(self.message_handler.route_handler.provided_node_features())
-                       .or(self.message_handler.onion_message_handler.provided_node_features());
+                       | self.message_handler.route_handler.provided_node_features()
+                       | self.message_handler.onion_message_handler.provided_node_features()
+                       | self.message_handler.custom_message_handler.provided_node_features();
                let announcement = msgs::UnsignedNodeAnnouncement {
                        features,
                        timestamp: self.last_node_announcement_serial.fetch_add(1, Ordering::AcqRel),
@@ -2395,16 +2481,21 @@ fn is_gossip_msg(type_id: u16) -> bool {
 mod tests {
        use crate::sign::{NodeSigner, Recipient};
        use crate::events;
+       use crate::io;
+       use crate::ln::features::{InitFeatures, NodeFeatures};
        use crate::ln::peer_channel_encryptor::PeerChannelEncryptor;
-       use crate::ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler, filter_addresses};
+       use crate::ln::peer_handler::{CustomMessageHandler, PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler, filter_addresses};
        use crate::ln::{msgs, wire};
-       use crate::ln::msgs::NetAddress;
+       use crate::ln::msgs::{LightningError, NetAddress};
        use crate::util::test_utils;
 
-       use bitcoin::secp256k1::SecretKey;
+       use bitcoin::Network;
+       use bitcoin::blockdata::constants::ChainHash;
+       use bitcoin::secp256k1::{PublicKey, SecretKey};
 
        use crate::prelude::*;
        use crate::sync::{Arc, Mutex};
+       use core::convert::Infallible;
        use core::sync::atomic::{AtomicBool, Ordering};
 
        #[derive(Clone)]
@@ -2437,19 +2528,51 @@ mod tests {
        struct PeerManagerCfg {
                chan_handler: test_utils::TestChannelMessageHandler,
                routing_handler: test_utils::TestRoutingMessageHandler,
+               custom_handler: TestCustomMessageHandler,
                logger: test_utils::TestLogger,
                node_signer: test_utils::TestNodeSigner,
        }
 
+       struct TestCustomMessageHandler {
+               features: InitFeatures,
+       }
+
+       impl wire::CustomMessageReader for TestCustomMessageHandler {
+               type CustomMessage = Infallible;
+               fn read<R: io::Read>(&self, _: u16, _: &mut R) -> Result<Option<Self::CustomMessage>, msgs::DecodeError> {
+                       Ok(None)
+               }
+       }
+
+       impl CustomMessageHandler for TestCustomMessageHandler {
+               fn handle_custom_message(&self, _: Infallible, _: &PublicKey) -> Result<(), LightningError> {
+                       unreachable!();
+               }
+
+               fn get_and_clear_pending_msg(&self) -> Vec<(PublicKey, Self::CustomMessage)> { Vec::new() }
+
+               fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
+
+               fn provided_init_features(&self, _: &PublicKey) -> InitFeatures {
+                       self.features.clone()
+               }
+       }
+
        fn create_peermgr_cfgs(peer_count: usize) -> Vec<PeerManagerCfg> {
                let mut cfgs = Vec::new();
                for i in 0..peer_count {
                        let node_secret = SecretKey::from_slice(&[42 + i as u8; 32]).unwrap();
+                       let features = {
+                               let mut feature_bits = vec![0u8; 33];
+                               feature_bits[32] = 0b00000001;
+                               InitFeatures::from_le_bytes(feature_bits)
+                       };
                        cfgs.push(
                                PeerManagerCfg{
-                                       chan_handler: test_utils::TestChannelMessageHandler::new(),
+                                       chan_handler: test_utils::TestChannelMessageHandler::new(ChainHash::using_genesis_block(Network::Testnet)),
                                        logger: test_utils::TestLogger::new(),
                                        routing_handler: test_utils::TestRoutingMessageHandler::new(),
+                                       custom_handler: TestCustomMessageHandler { features },
                                        node_signer: test_utils::TestNodeSigner::new(node_secret),
                                }
                        );
@@ -2458,13 +2581,56 @@ mod tests {
                cfgs
        }
 
-       fn create_network<'a>(peer_count: usize, cfgs: &'a Vec<PeerManagerCfg>) -> Vec<PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, IgnoringMessageHandler, &'a test_utils::TestLogger, IgnoringMessageHandler, &'a test_utils::TestNodeSigner>> {
+       fn create_feature_incompatible_peermgr_cfgs(peer_count: usize) -> Vec<PeerManagerCfg> {
+               let mut cfgs = Vec::new();
+               for i in 0..peer_count {
+                       let node_secret = SecretKey::from_slice(&[42 + i as u8; 32]).unwrap();
+                       let features = {
+                               let mut feature_bits = vec![0u8; 33 + i + 1];
+                               feature_bits[33 + i] = 0b00000001;
+                               InitFeatures::from_le_bytes(feature_bits)
+                       };
+                       cfgs.push(
+                               PeerManagerCfg{
+                                       chan_handler: test_utils::TestChannelMessageHandler::new(ChainHash::using_genesis_block(Network::Testnet)),
+                                       logger: test_utils::TestLogger::new(),
+                                       routing_handler: test_utils::TestRoutingMessageHandler::new(),
+                                       custom_handler: TestCustomMessageHandler { features },
+                                       node_signer: test_utils::TestNodeSigner::new(node_secret),
+                               }
+                       );
+               }
+
+               cfgs
+       }
+
+       fn create_chain_incompatible_peermgr_cfgs(peer_count: usize) -> Vec<PeerManagerCfg> {
+               let mut cfgs = Vec::new();
+               for i in 0..peer_count {
+                       let node_secret = SecretKey::from_slice(&[42 + i as u8; 32]).unwrap();
+                       let features = InitFeatures::from_le_bytes(vec![0u8; 33]);
+                       let network = ChainHash::from(&[i as u8; 32][..]);
+                       cfgs.push(
+                               PeerManagerCfg{
+                                       chan_handler: test_utils::TestChannelMessageHandler::new(network),
+                                       logger: test_utils::TestLogger::new(),
+                                       routing_handler: test_utils::TestRoutingMessageHandler::new(),
+                                       custom_handler: TestCustomMessageHandler { features },
+                                       node_signer: test_utils::TestNodeSigner::new(node_secret),
+                               }
+                       );
+               }
+
+               cfgs
+       }
+
+       fn create_network<'a>(peer_count: usize, cfgs: &'a Vec<PeerManagerCfg>) -> Vec<PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, IgnoringMessageHandler, &'a test_utils::TestLogger, &'a TestCustomMessageHandler, &'a test_utils::TestNodeSigner>> {
                let mut peers = Vec::new();
                for i in 0..peer_count {
                        let ephemeral_bytes = [i as u8; 32];
                        let msg_handler = MessageHandler {
                                chan_handler: &cfgs[i].chan_handler, route_handler: &cfgs[i].routing_handler,
-                               onion_message_handler: IgnoringMessageHandler {}, custom_message_handler: IgnoringMessageHandler {}
+                               onion_message_handler: IgnoringMessageHandler {}, custom_message_handler: &cfgs[i].custom_handler
                        };
                        let peer = PeerManager::new(msg_handler, 0, &ephemeral_bytes, &cfgs[i].logger, &cfgs[i].node_signer);
                        peers.push(peer);
@@ -2473,7 +2639,7 @@ mod tests {
                peers
        }
 
-       fn establish_connection<'a>(peer_a: &PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, IgnoringMessageHandler, &'a test_utils::TestLogger, IgnoringMessageHandler, &'a test_utils::TestNodeSigner>, peer_b: &PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, IgnoringMessageHandler, &'a test_utils::TestLogger, IgnoringMessageHandler, &'a test_utils::TestNodeSigner>) -> (FileDescriptor, FileDescriptor) {
+       fn establish_connection<'a>(peer_a: &PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, IgnoringMessageHandler, &'a test_utils::TestLogger, &'a TestCustomMessageHandler, &'a test_utils::TestNodeSigner>, peer_b: &PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, IgnoringMessageHandler, &'a test_utils::TestLogger, &'a TestCustomMessageHandler, &'a test_utils::TestNodeSigner>) -> (FileDescriptor, FileDescriptor) {
                let id_a = peer_a.node_signer.get_node_id(Recipient::Node).unwrap();
                let mut fd_a = FileDescriptor {
                        fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())),
@@ -2588,6 +2754,78 @@ mod tests {
                thrd_b.join().unwrap();
        }
 
+       #[test]
+       fn test_feature_incompatible_peers() {
+               let cfgs = create_peermgr_cfgs(2);
+               let incompatible_cfgs = create_feature_incompatible_peermgr_cfgs(2);
+
+               let peers = create_network(2, &cfgs);
+               let incompatible_peers = create_network(2, &incompatible_cfgs);
+               let peer_pairs = [(&peers[0], &incompatible_peers[0]), (&incompatible_peers[1], &peers[1])];
+               for (peer_a, peer_b) in peer_pairs.iter() {
+                       let id_a = peer_a.node_signer.get_node_id(Recipient::Node).unwrap();
+                       let mut fd_a = FileDescriptor {
+                               fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())),
+                               disconnect: Arc::new(AtomicBool::new(false)),
+                       };
+                       let addr_a = NetAddress::IPv4{addr: [127, 0, 0, 1], port: 1000};
+                       let mut fd_b = FileDescriptor {
+                               fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())),
+                               disconnect: Arc::new(AtomicBool::new(false)),
+                       };
+                       let addr_b = NetAddress::IPv4{addr: [127, 0, 0, 1], port: 1001};
+                       let initial_data = peer_b.new_outbound_connection(id_a, fd_b.clone(), Some(addr_a.clone())).unwrap();
+                       peer_a.new_inbound_connection(fd_a.clone(), Some(addr_b.clone())).unwrap();
+                       assert_eq!(peer_a.read_event(&mut fd_a, &initial_data).unwrap(), false);
+                       peer_a.process_events();
+
+                       let a_data = fd_a.outbound_data.lock().unwrap().split_off(0);
+                       assert_eq!(peer_b.read_event(&mut fd_b, &a_data).unwrap(), false);
+
+                       peer_b.process_events();
+                       let b_data = fd_b.outbound_data.lock().unwrap().split_off(0);
+
+                       // Should fail because of unknown required features
+                       assert!(peer_a.read_event(&mut fd_a, &b_data).is_err());
+               }
+       }
+
+       #[test]
+       fn test_chain_incompatible_peers() {
+               let cfgs = create_peermgr_cfgs(2);
+               let incompatible_cfgs = create_chain_incompatible_peermgr_cfgs(2);
+
+               let peers = create_network(2, &cfgs);
+               let incompatible_peers = create_network(2, &incompatible_cfgs);
+               let peer_pairs = [(&peers[0], &incompatible_peers[0]), (&incompatible_peers[1], &peers[1])];
+               for (peer_a, peer_b) in peer_pairs.iter() {
+                       let id_a = peer_a.node_signer.get_node_id(Recipient::Node).unwrap();
+                       let mut fd_a = FileDescriptor {
+                               fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())),
+                               disconnect: Arc::new(AtomicBool::new(false)),
+                       };
+                       let addr_a = NetAddress::IPv4{addr: [127, 0, 0, 1], port: 1000};
+                       let mut fd_b = FileDescriptor {
+                               fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())),
+                               disconnect: Arc::new(AtomicBool::new(false)),
+                       };
+                       let addr_b = NetAddress::IPv4{addr: [127, 0, 0, 1], port: 1001};
+                       let initial_data = peer_b.new_outbound_connection(id_a, fd_b.clone(), Some(addr_a.clone())).unwrap();
+                       peer_a.new_inbound_connection(fd_a.clone(), Some(addr_b.clone())).unwrap();
+                       assert_eq!(peer_a.read_event(&mut fd_a, &initial_data).unwrap(), false);
+                       peer_a.process_events();
+
+                       let a_data = fd_a.outbound_data.lock().unwrap().split_off(0);
+                       assert_eq!(peer_b.read_event(&mut fd_b, &a_data).unwrap(), false);
+
+                       peer_b.process_events();
+                       let b_data = fd_b.outbound_data.lock().unwrap().split_off(0);
+
+                       // Should fail because of incompatible chains
+                       assert!(peer_a.read_event(&mut fd_a, &b_data).is_err());
+               }
+       }
+
        #[test]
        fn test_disconnect_peer() {
                // Simple test which builds a network of PeerManager, connects and brings them to NoiseState::Finished and
@@ -2612,8 +2850,8 @@ mod tests {
                // Simple test which builds a network of PeerManager, connects and brings them to NoiseState::Finished and
                // push a message from one peer to another.
                let cfgs = create_peermgr_cfgs(2);
-               let a_chan_handler = test_utils::TestChannelMessageHandler::new();
-               let b_chan_handler = test_utils::TestChannelMessageHandler::new();
+               let a_chan_handler = test_utils::TestChannelMessageHandler::new(ChainHash::using_genesis_block(Network::Testnet));
+               let b_chan_handler = test_utils::TestChannelMessageHandler::new(ChainHash::using_genesis_block(Network::Testnet));
                let mut peers = create_network(2, &cfgs);
                let (fd_a, mut fd_b) = establish_connection(&peers[0], &peers[1]);
                assert_eq!(peers[0].peers.read().unwrap().len(), 1);