Avoid taking the peers write lock during event processing
[rust-lightning] / lightning / src / ln / peer_handler.rs
index 80edebc69b428bc5c16db95899005c5dac1f9e05..5836a8d093187785aeee5373ccff95fbe9990217 100644 (file)
@@ -19,24 +19,24 @@ use bitcoin::secp256k1::key::{SecretKey,PublicKey};
 
 use ln::features::InitFeatures;
 use ln::msgs;
-use ln::msgs::{ChannelMessageHandler, LightningError, RoutingMessageHandler};
+use ln::msgs::{ChannelMessageHandler, LightningError, NetAddress, RoutingMessageHandler};
 use ln::channelmanager::{SimpleArcChannelManager, SimpleRefChannelManager};
 use util::ser::{VecWriter, Writeable, Writer};
 use ln::peer_channel_encryptor::{PeerChannelEncryptor,NextNoiseStep};
 use ln::wire;
-use util::byte_utils;
+use ln::wire::Encode;
+use util::atomic_counter::AtomicCounter;
 use util::events::{MessageSendEvent, MessageSendEventsProvider};
 use util::logger::Logger;
-use routing::network_graph::NetGraphMsgHandler;
+use routing::network_graph::{NetworkGraph, NetGraphMsgHandler};
 
 use prelude::*;
 use io;
 use alloc::collections::LinkedList;
-use alloc::fmt::Debug;
-use sync::{Arc, Mutex};
-use core::sync::atomic::{AtomicUsize, Ordering};
+use sync::{Arc, Mutex, MutexGuard, RwLock};
 use core::{cmp, hash, fmt, mem};
 use core::ops::Deref;
+use core::convert::Infallible;
 #[cfg(feature = "std")] use std::error;
 
 use bitcoin::hashes::sha256::Hash as Sha256;
@@ -69,7 +69,7 @@ impl RoutingMessageHandler for IgnoringMessageHandler {
        fn get_next_channel_announcements(&self, _starting_point: u64, _batch_amount: u8) ->
                Vec<(msgs::ChannelAnnouncement, Option<msgs::ChannelUpdate>, Option<msgs::ChannelUpdate>)> { Vec::new() }
        fn get_next_node_announcements(&self, _starting_point: Option<&PublicKey>, _batch_amount: u8) -> Vec<msgs::NodeAnnouncement> { Vec::new() }
-       fn sync_routing_table(&self, _their_node_id: &PublicKey, _init: &msgs::Init) {}
+       fn peer_connected(&self, _their_node_id: &PublicKey, _init: &msgs::Init) {}
        fn handle_reply_channel_range(&self, _their_node_id: &PublicKey, _msg: msgs::ReplyChannelRange) -> Result<(), LightningError> { Ok(()) }
        fn handle_reply_short_channel_ids_end(&self, _their_node_id: &PublicKey, _msg: msgs::ReplyShortChannelIdsEnd) -> Result<(), LightningError> { Ok(()) }
        fn handle_query_channel_range(&self, _their_node_id: &PublicKey, _msg: msgs::QueryChannelRange) -> Result<(), LightningError> { Ok(()) }
@@ -80,28 +80,28 @@ impl Deref for IgnoringMessageHandler {
        fn deref(&self) -> &Self { self }
 }
 
-impl wire::Type for () {
+// Implement Type for Infallible, note that it cannot be constructed, and thus you can never call a
+// method that takes self for it.
+impl wire::Type for Infallible {
        fn type_id(&self) -> u16 {
-               // We should never call this for `DummyCustomType`
                unreachable!();
        }
 }
-
-impl Writeable for () {
+impl Writeable for Infallible {
        fn write<W: Writer>(&self, _: &mut W) -> Result<(), io::Error> {
                unreachable!();
        }
 }
 
 impl wire::CustomMessageReader for IgnoringMessageHandler {
-       type CustomMessage = ();
+       type CustomMessage = Infallible;
        fn read<R: io::Read>(&self, _message_type: u16, _buffer: &mut R) -> Result<Option<Self::CustomMessage>, msgs::DecodeError> {
                Ok(None)
        }
 }
 
 impl CustomMessageHandler for IgnoringMessageHandler {
-       fn handle_custom_message(&self, _msg: Self::CustomMessage, _sender_node_id: &PublicKey) -> Result<(), LightningError> {
+       fn handle_custom_message(&self, _msg: Infallible, _sender_node_id: &PublicKey) -> Result<(), LightningError> {
                // Since we always return `None` in the read the handle method should never be called.
                unreachable!();
        }
@@ -285,6 +285,10 @@ enum InitSyncTracker{
        NodesSyncing(PublicKey),
 }
 
+/// The ratio between buffer sizes at which we stop sending initial sync messages vs when we stop
+/// forwarding gossip messages to peers altogether.
+const FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO: usize = 2;
+
 /// When the outbound buffer has this many messages, we'll stop reading bytes from the peer until
 /// we have fewer than this many messages in the outbound buffer again.
 /// We also use this as the target number of outbound gossip messages to keep in the write buffer,
@@ -292,12 +296,35 @@ enum InitSyncTracker{
 const OUTBOUND_BUFFER_LIMIT_READ_PAUSE: usize = 10;
 /// When the outbound buffer has this many messages, we'll simply skip relaying gossip messages to
 /// the peer.
-const OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP: usize = 20;
+const OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP: usize = OUTBOUND_BUFFER_LIMIT_READ_PAUSE * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO;
+
+/// If we've sent a ping, and are still awaiting a response, we may need to churn our way through
+/// the socket receive buffer before receiving the ping.
+///
+/// On a fairly old Arm64 board, with Linux defaults, this can take as long as 20 seconds, not
+/// including any network delays, outbound traffic, or the same for messages from other peers.
+///
+/// Thus, to avoid needlessly disconnecting a peer, we allow a peer to take this many timer ticks
+/// per connected peer to respond to a ping, as long as they send us at least one message during
+/// each tick, ensuring we aren't actually just disconnected.
+/// With a timer tick interval of ten seconds, this translates to about 40 seconds per connected
+/// peer.
+///
+/// When we improve parallelism somewhat we should reduce this to e.g. this many timer ticks per
+/// two connected peers, assuming most LDK-running systems have at least two cores.
+const MAX_BUFFER_DRAIN_TICK_INTERVALS_PER_PEER: i8 = 4;
+
+/// This is the minimum number of messages we expect a peer to be able to handle within one timer
+/// tick. Once we have sent this many messages since the last ping, we send a ping right away to
+/// ensures we don't just fill up our send buffer and leave the peer with too many messages to
+/// process before the next ping.
+const BUFFER_DRAIN_MSGS_PER_TICK: usize = 32;
 
 struct Peer {
        channel_encryptor: PeerChannelEncryptor,
        their_node_id: Option<PublicKey>,
        their_features: Option<InitFeatures>,
+       their_net_address: Option<NetAddress>,
 
        pending_outbound_buffer: LinkedList<Vec<u8>>,
        pending_outbound_buffer_first_msg_offset: usize,
@@ -309,7 +336,10 @@ struct Peer {
 
        sync_status: InitSyncTracker,
 
-       awaiting_pong: bool,
+       msgs_sent_since_pong: usize,
+       awaiting_pong_timer_tick_intervals: i8,
+       received_message_since_timer_tick: bool,
+       sent_gossip_timestamp_filter: bool,
 }
 
 impl Peer {
@@ -319,7 +349,11 @@ impl Peer {
        /// announcements/updates for the given channel_id then we will send it when we get to that
        /// point and we shouldn't send it yet to avoid sending duplicate updates. If we've already
        /// sent the old versions, we should send the update, and so return true here.
-       fn should_forward_channel_announcement(&self, channel_id: u64)->bool{
+       fn should_forward_channel_announcement(&self, channel_id: u64) -> bool {
+               if self.their_features.as_ref().unwrap().supports_gossip_queries() &&
+                       !self.sent_gossip_timestamp_filter {
+                               return false;
+                       }
                match self.sync_status {
                        InitSyncTracker::NoSyncRequested => true,
                        InitSyncTracker::ChannelsSyncing(i) => i < channel_id,
@@ -329,6 +363,10 @@ impl Peer {
 
        /// Similar to the above, but for node announcements indexed by node_id.
        fn should_forward_node_announcement(&self, node_id: PublicKey) -> bool {
+               if self.their_features.as_ref().unwrap().supports_gossip_queries() &&
+                       !self.sent_gossip_timestamp_filter {
+                               return false;
+                       }
                match self.sync_status {
                        InitSyncTracker::NoSyncRequested => true,
                        InitSyncTracker::ChannelsSyncing(_) => false,
@@ -338,15 +376,11 @@ impl Peer {
 }
 
 struct PeerHolder<Descriptor: SocketDescriptor> {
-       peers: HashMap<Descriptor, Peer>,
-       /// Only add to this set when noise completes:
-       node_id_to_descriptor: HashMap<PublicKey, Descriptor>,
-}
-
-#[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
-fn _check_usize_is_32_or_64() {
-       // See below, less than 32 bit pointers may be unsafe here!
-       unsafe { mem::transmute::<*const usize, [u8; 4]>(panic!()); }
+       /// Peer is under its own mutex for sending and receiving bytes, but note that we do *not* hold
+       /// this mutex while we're processing a message. This is fine as [`PeerManager::read_event`]
+       /// requires that there be no parallel calls for a given peer, so mutual exclusion of messages
+       /// handed to the `MessageHandler`s for a given peer is already guaranteed.
+       peers: HashMap<Descriptor, Mutex<Peer>>,
 }
 
 /// SimpleArcPeerManager is useful when you need a PeerManager with a static lifetime, e.g.
@@ -354,7 +388,9 @@ fn _check_usize_is_32_or_64() {
 /// lifetimes). Other times you can afford a reference, which is more efficient, in which case
 /// SimpleRefPeerManager is the more appropriate type. Defining these type aliases prevents
 /// issues such as overly long function definitions.
-pub type SimpleArcPeerManager<SD, M, T, F, C, L> = PeerManager<SD, Arc<SimpleArcChannelManager<M, T, F, L>>, Arc<NetGraphMsgHandler<Arc<C>, Arc<L>>>, Arc<L>, Arc<IgnoringMessageHandler>>;
+///
+/// (C-not exported) as Arcs don't make sense in bindings
+pub type SimpleArcPeerManager<SD, M, T, F, C, L> = PeerManager<SD, Arc<SimpleArcChannelManager<M, T, F, L>>, Arc<NetGraphMsgHandler<Arc<NetworkGraph>, Arc<C>, Arc<L>>>, Arc<L>, Arc<IgnoringMessageHandler>>;
 
 /// 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
@@ -362,7 +398,9 @@ pub type SimpleArcPeerManager<SD, M, T, F, C, L> = PeerManager<SD, Arc<SimpleArc
 /// usage of lightning-net-tokio (since tokio::spawn requires parameters with static lifetimes).
 /// But if this is not necessary, using a reference is more efficient. Defining these type aliases
 /// helps with issues such as long function definitions.
-pub type SimpleRefPeerManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, SD, M, T, F, C, L> = PeerManager<SD, SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L>, &'e NetGraphMsgHandler<&'g C, &'f L>, &'f L, IgnoringMessageHandler>;
+///
+/// (C-not exported) as Arcs don't make sense in bindings
+pub type SimpleRefPeerManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, SD, M, T, F, C, L> = PeerManager<SD, SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L>, &'e NetGraphMsgHandler<&'g NetworkGraph, &'h C, &'f L>, &'f L, IgnoringMessageHandler>;
 
 /// A PeerManager manages a set of peers, described by their [`SocketDescriptor`] and marshalls
 /// socket events into messages which it passes on to its [`MessageHandler`].
@@ -389,15 +427,21 @@ pub struct PeerManager<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: De
                L::Target: Logger,
                CMH::Target: CustomMessageHandler {
        message_handler: MessageHandler<CM, RM>,
-       peers: Mutex<PeerHolder<Descriptor>>,
+       peers: RwLock<PeerHolder<Descriptor>>,
+       /// Only add to this set when noise completes.
+       /// Locked *after* peers. When an item is removed, it must be removed with the `peers` write
+       /// lock held. Entries may be added with only the `peers` read lock held (though the
+       /// `Descriptor` value must already exist in `peers`).
+       node_id_to_descriptor: Mutex<HashMap<PublicKey, Descriptor>>,
+       /// We can only have one thread processing events at once, but we don't usually need the full
+       /// `peers` write lock to do so, so instead we block on this empty mutex when entering
+       /// `process_events`.
+       event_processing_lock: Mutex<()>,
        our_node_secret: SecretKey,
        ephemeral_key_midstate: Sha256Engine,
        custom_message_handler: CMH,
 
-       // Usize needs to be at least 32 bits to avoid overflowing both low and high. If usize is 64
-       // bits we will never realistically count into high:
-       peer_counter_low: AtomicUsize,
-       peer_counter_high: AtomicUsize,
+       peer_counter: AtomicCounter,
 
        logger: L,
 }
@@ -465,11 +509,52 @@ impl<Descriptor: SocketDescriptor, RM: Deref, L: Deref> PeerManager<Descriptor,
        }
 }
 
+/// A simple wrapper that optionally prints " from <pubkey>" for an optional pubkey.
+/// This works around `format!()` taking a reference to each argument, preventing
+/// `if let Some(node_id) = peer.their_node_id { format!(.., node_id) } else { .. }` from compiling
+/// due to lifetime errors.
+struct OptionalFromDebugger<'a>(&'a Option<PublicKey>);
+impl core::fmt::Display for OptionalFromDebugger<'_> {
+       fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> Result<(), core::fmt::Error> {
+               if let Some(node_id) = self.0 { write!(f, " from {}", log_pubkey!(node_id)) } else { Ok(()) }
+       }
+}
+
+/// A function used to filter out local or private addresses
+/// https://www.iana.org./assignments/ipv4-address-space/ipv4-address-space.xhtml
+/// https://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.xhtml
+fn filter_addresses(ip_address: Option<NetAddress>) -> Option<NetAddress> {
+       match ip_address{
+               // For IPv4 range 10.0.0.0 - 10.255.255.255 (10/8)
+               Some(NetAddress::IPv4{addr: [10, _, _, _], port: _}) => None,
+               // For IPv4 range 0.0.0.0 - 0.255.255.255 (0/8)
+               Some(NetAddress::IPv4{addr: [0, _, _, _], port: _}) => None,
+               // For IPv4 range 100.64.0.0 - 100.127.255.255 (100.64/10)
+               Some(NetAddress::IPv4{addr: [100, 64..=127, _, _], port: _}) => None,
+               // For IPv4 range       127.0.0.0 - 127.255.255.255 (127/8)
+               Some(NetAddress::IPv4{addr: [127, _, _, _], port: _}) => None,
+               // For IPv4 range       169.254.0.0 - 169.254.255.255 (169.254/16)
+               Some(NetAddress::IPv4{addr: [169, 254, _, _], port: _}) => None,
+               // For IPv4 range 172.16.0.0 - 172.31.255.255 (172.16/12)
+               Some(NetAddress::IPv4{addr: [172, 16..=31, _, _], port: _}) => None,
+               // For IPv4 range 192.168.0.0 - 192.168.255.255 (192.168/16)
+               Some(NetAddress::IPv4{addr: [192, 168, _, _], port: _}) => None,
+               // For IPv4 range 192.88.99.0 - 192.88.99.255  (192.88.99/24)
+               Some(NetAddress::IPv4{addr: [192, 88, 99, _], port: _}) => None,
+               // For IPv6 range 2000:0000:0000:0000:0000:0000:0000:0000 - 3fff:ffff:ffff:ffff:ffff:ffff:ffff:ffff (2000::/3)
+               Some(NetAddress::IPv6{addr: [0x20..=0x3F, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _], port: _}) => ip_address,
+               // For remaining addresses
+               Some(NetAddress::IPv6{addr: _, port: _}) => None,
+               Some(..) => ip_address,
+               None => None,
+       }
+}
+
 impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> PeerManager<Descriptor, CM, RM, L, CMH> where
                CM::Target: ChannelMessageHandler,
                RM::Target: RoutingMessageHandler,
                L::Target: Logger,
-               CMH::Target: CustomMessageHandler + wire::CustomMessageReader {
+               CMH::Target: CustomMessageHandler {
        /// Constructs a new PeerManager with the given message handlers and node_id secret key
        /// ephemeral_random_data is used to derive per-connection ephemeral keys and must be
        /// cryptographically secure random bytes.
@@ -479,14 +564,14 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
                PeerManager {
                        message_handler,
-                       peers: Mutex::new(PeerHolder {
+                       peers: RwLock::new(PeerHolder {
                                peers: HashMap::new(),
-                               node_id_to_descriptor: HashMap::new()
                        }),
+                       node_id_to_descriptor: Mutex::new(HashMap::new()),
+                       event_processing_lock: Mutex::new(()),
                        our_node_secret,
                        ephemeral_key_midstate,
-                       peer_counter_low: AtomicUsize::new(0),
-                       peer_counter_high: AtomicUsize::new(0),
+                       peer_counter: AtomicCounter::new(),
                        logger,
                        custom_message_handler,
                }
@@ -498,8 +583,9 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        /// new_outbound_connection, however entries will only appear once the initial handshake has
        /// completed and we are sure the remote peer has the private key for the given node_id.
        pub fn get_peer_node_ids(&self) -> Vec<PublicKey> {
-               let peers = self.peers.lock().unwrap();
-               peers.peers.values().filter_map(|p| {
+               let peers = self.peers.read().unwrap();
+               peers.peers.values().filter_map(|peer_mutex| {
+                       let p = peer_mutex.lock().unwrap();
                        if !p.channel_encryptor.is_ready_for_encryption() || p.their_features.is_none() {
                                return None;
                        }
@@ -509,18 +595,18 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
        fn get_ephemeral_key(&self) -> SecretKey {
                let mut ephemeral_hash = self.ephemeral_key_midstate.clone();
-               let low = self.peer_counter_low.fetch_add(1, Ordering::AcqRel);
-               let high = if low == 0 {
-                       self.peer_counter_high.fetch_add(1, Ordering::AcqRel)
-               } else {
-                       self.peer_counter_high.load(Ordering::Acquire)
-               };
-               ephemeral_hash.input(&byte_utils::le64_to_array(low as u64));
-               ephemeral_hash.input(&byte_utils::le64_to_array(high as u64));
+               let counter = self.peer_counter.get_increment();
+               ephemeral_hash.input(&counter.to_le_bytes());
                SecretKey::from_slice(&Sha256::from_engine(ephemeral_hash).into_inner()).expect("You broke SHA-256!")
        }
 
-       /// Indicates a new outbound connection has been established to a node with the given node_id.
+       /// Indicates a new outbound connection has been established to a node with the given node_id
+       /// and an optional remote network address.
+       ///
+       /// The remote network address adds the option to report a remote IP address back to a connecting
+       /// peer using the init message.
+       /// The user should pass the remote network address of the host they are connected to.
+       ///
        /// Note that if an Err is returned here you MUST NOT call socket_disconnected for the new
        /// descriptor but must disconnect the connection immediately.
        ///
@@ -530,16 +616,17 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        /// [`socket_disconnected()`].
        ///
        /// [`socket_disconnected()`]: PeerManager::socket_disconnected
-       pub fn new_outbound_connection(&self, their_node_id: PublicKey, descriptor: Descriptor) -> Result<Vec<u8>, PeerHandleError> {
+       pub fn new_outbound_connection(&self, their_node_id: PublicKey, descriptor: Descriptor, remote_network_address: Option<NetAddress>) -> Result<Vec<u8>, PeerHandleError> {
                let mut peer_encryptor = PeerChannelEncryptor::new_outbound(their_node_id.clone(), self.get_ephemeral_key());
                let res = peer_encryptor.get_act_one().to_vec();
                let pending_read_buffer = [0; 50].to_vec(); // Noise act two is 50 bytes
 
-               let mut peers = self.peers.lock().unwrap();
-               if peers.peers.insert(descriptor, Peer {
+               let mut peers = self.peers.write().unwrap();
+               if peers.peers.insert(descriptor, Mutex::new(Peer {
                        channel_encryptor: peer_encryptor,
                        their_node_id: None,
                        their_features: None,
+                       their_net_address: remote_network_address,
 
                        pending_outbound_buffer: LinkedList::new(),
                        pending_outbound_buffer_first_msg_offset: 0,
@@ -551,14 +638,22 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
                        sync_status: InitSyncTracker::NoSyncRequested,
 
-                       awaiting_pong: false,
-               }).is_some() {
+                       msgs_sent_since_pong: 0,
+                       awaiting_pong_timer_tick_intervals: 0,
+                       received_message_since_timer_tick: false,
+                       sent_gossip_timestamp_filter: false,
+               })).is_some() {
                        panic!("PeerManager driver duplicated descriptors!");
                };
                Ok(res)
        }
 
-       /// Indicates a new inbound connection has been established.
+       /// Indicates a new inbound connection has been established to a node with an optional remote
+       /// network address.
+       ///
+       /// The remote network address adds the option to report a remote IP address back to a connecting
+       /// peer using the init message.
+       /// The user should pass the remote network address of the host they are connected to.
        ///
        /// May refuse the connection by returning an Err, but will never write bytes to the remote end
        /// (outbound connector always speaks first). Note that if an Err is returned here you MUST NOT
@@ -569,15 +664,16 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        /// [`socket_disconnected()`].
        ///
        /// [`socket_disconnected()`]: PeerManager::socket_disconnected
-       pub fn new_inbound_connection(&self, descriptor: Descriptor) -> Result<(), PeerHandleError> {
+       pub fn new_inbound_connection(&self, descriptor: Descriptor, remote_network_address: Option<NetAddress>) -> Result<(), PeerHandleError> {
                let peer_encryptor = PeerChannelEncryptor::new_inbound(&self.our_node_secret);
                let pending_read_buffer = [0; 50].to_vec(); // Noise act one is 50 bytes
 
-               let mut peers = self.peers.lock().unwrap();
-               if peers.peers.insert(descriptor, Peer {
+               let mut peers = self.peers.write().unwrap();
+               if peers.peers.insert(descriptor, Mutex::new(Peer {
                        channel_encryptor: peer_encryptor,
                        their_node_id: None,
                        their_features: None,
+                       their_net_address: remote_network_address,
 
                        pending_outbound_buffer: LinkedList::new(),
                        pending_outbound_buffer_first_msg_offset: 0,
@@ -589,8 +685,11 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
                        sync_status: InitSyncTracker::NoSyncRequested,
 
-                       awaiting_pong: false,
-               }).is_some() {
+                       msgs_sent_since_pong: 0,
+                       awaiting_pong_timer_tick_intervals: 0,
+                       received_message_since_timer_tick: false,
+                       sent_gossip_timestamp_filter: false,
+               })).is_some() {
                        panic!("PeerManager driver duplicated descriptors!");
                };
                Ok(())
@@ -598,7 +697,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
 
        fn do_attempt_write_data(&self, descriptor: &mut Descriptor, peer: &mut Peer) {
                while !peer.awaiting_write_event {
-                       if peer.pending_outbound_buffer.len() < OUTBOUND_BUFFER_LIMIT_READ_PAUSE {
+                       if peer.pending_outbound_buffer.len() < OUTBOUND_BUFFER_LIMIT_READ_PAUSE && peer.msgs_sent_since_pong < BUFFER_DRAIN_MSGS_PER_TICK {
                                match peer.sync_status {
                                        InitSyncTracker::NoSyncRequested => {},
                                        InitSyncTracker::ChannelsSyncing(c) if c < 0xffff_ffff_ffff_ffff => {
@@ -643,6 +742,9 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                        },
                                }
                        }
+                       if peer.msgs_sent_since_pong >= BUFFER_DRAIN_MSGS_PER_TICK {
+                               self.maybe_send_extra_ping(peer);
+                       }
 
                        if {
                                let next_buff = match peer.pending_outbound_buffer.front() {
@@ -677,17 +779,18 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        /// [`send_data`]: SocketDescriptor::send_data
        /// [`write_buffer_space_avail`]: PeerManager::write_buffer_space_avail
        pub fn write_buffer_space_avail(&self, descriptor: &mut Descriptor) -> Result<(), PeerHandleError> {
-               let mut peers = self.peers.lock().unwrap();
-               match peers.peers.get_mut(descriptor) {
+               let peers = self.peers.read().unwrap();
+               match peers.peers.get(descriptor) {
                        None => {
                                // This is most likely a simple race condition where the user found that the socket
                                // was writeable, then we told the user to `disconnect_socket()`, then they called
                                // this method. Return an error to make sure we get disconnected.
                                return Err(PeerHandleError { no_connection_possible: false });
                        },
-                       Some(peer) => {
+                       Some(peer_mutex) => {
+                               let mut peer = peer_mutex.lock().unwrap();
                                peer.awaiting_write_event = false;
-                               self.do_attempt_write_data(descriptor, peer);
+                               self.do_attempt_write_data(descriptor, &mut peer);
                        }
                };
                Ok(())
@@ -718,195 +821,237 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                }
        }
 
-       /// Append a message to a peer's pending outbound/write buffer, and update the map of peers needing sends accordingly.
-       fn enqueue_message<M: wire::Type + Writeable + Debug>(&self, peer: &mut Peer, message: &M) {
+       /// Append a message to a peer's pending outbound/write buffer
+       fn enqueue_encoded_message(&self, peer: &mut Peer, encoded_message: &Vec<u8>) {
+               peer.msgs_sent_since_pong += 1;
+               peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_message[..]));
+       }
+
+       /// Append a message to a peer's pending outbound/write buffer
+       fn enqueue_message<M: wire::Type>(&self, peer: &mut Peer, message: &M) {
                let mut buffer = VecWriter(Vec::with_capacity(2048));
                wire::write(message, &mut buffer).unwrap(); // crash if the write failed
-               let encoded_message = buffer.0;
 
-               log_trace!(self.logger, "Enqueueing message {:?} to {}", message, log_pubkey!(peer.their_node_id.unwrap()));
-               peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_message[..]));
+               if is_gossip_msg(message.type_id()) {
+                       log_gossip!(self.logger, "Enqueueing message {:?} to {}", message, log_pubkey!(peer.their_node_id.unwrap()));
+               } else {
+                       log_trace!(self.logger, "Enqueueing message {:?} to {}", message, log_pubkey!(peer.their_node_id.unwrap()))
+               }
+               self.enqueue_encoded_message(peer, &buffer.0);
        }
 
        fn do_read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
-               let pause_read = {
-                       let mut peers_lock = self.peers.lock().unwrap();
-                       let peers = &mut *peers_lock;
-                       let mut msgs_to_forward = Vec::new();
-                       let mut peer_node_id = None;
-                       let pause_read = match peers.peers.get_mut(peer_descriptor) {
-                               None => {
-                                       // This is most likely a simple race condition where the user read some bytes
-                                       // from the socket, then we told the user to `disconnect_socket()`, then they
-                                       // called this method. Return an error to make sure we get disconnected.
-                                       return Err(PeerHandleError { no_connection_possible: false });
-                               },
-                               Some(peer) => {
+               let mut pause_read = false;
+               let peers = self.peers.read().unwrap();
+               let mut msgs_to_forward = Vec::new();
+               let mut peer_node_id = None;
+               match peers.peers.get(peer_descriptor) {
+                       None => {
+                               // This is most likely a simple race condition where the user read some bytes
+                               // from the socket, then we told the user to `disconnect_socket()`, then they
+                               // called this method. Return an error to make sure we get disconnected.
+                               return Err(PeerHandleError { no_connection_possible: false });
+                       },
+                       Some(peer_mutex) => {
+                               let mut read_pos = 0;
+                               while read_pos < data.len() {
+                                       macro_rules! try_potential_handleerror {
+                                               ($peer: expr, $thing: expr) => {
+                                                       match $thing {
+                                                               Ok(x) => x,
+                                                               Err(e) => {
+                                                                       match e.action {
+                                                                               msgs::ErrorAction::DisconnectPeer { msg: _ } => {
+                                                                                       //TODO: Try to push msg
+                                                                                       log_debug!(self.logger, "Error handling message{}; disconnecting peer with: {}", OptionalFromDebugger(&peer_node_id), e.err);
+                                                                                       return Err(PeerHandleError{ no_connection_possible: false });
+                                                                               },
+                                                                               msgs::ErrorAction::IgnoreAndLog(level) => {
+                                                                                       log_given_level!(self.logger, level, "Error handling message{}; ignoring: {}", OptionalFromDebugger(&peer_node_id), e.err);
+                                                                                       continue
+                                                                               },
+                                                                               msgs::ErrorAction::IgnoreDuplicateGossip => continue, // Don't even bother logging these
+                                                                               msgs::ErrorAction::IgnoreError => {
+                                                                                       log_debug!(self.logger, "Error handling message{}; ignoring: {}", OptionalFromDebugger(&peer_node_id), e.err);
+                                                                                       continue;
+                                                                               },
+                                                                               msgs::ErrorAction::SendErrorMessage { msg } => {
+                                                                                       log_debug!(self.logger, "Error handling message{}; sending error message with: {}", OptionalFromDebugger(&peer_node_id), e.err);
+                                                                                       self.enqueue_message($peer, &msg);
+                                                                                       continue;
+                                                                               },
+                                                                               msgs::ErrorAction::SendWarningMessage { msg, log_level } => {
+                                                                                       log_given_level!(self.logger, log_level, "Error handling message{}; sending warning message with: {}", OptionalFromDebugger(&peer_node_id), e.err);
+                                                                                       self.enqueue_message($peer, &msg);
+                                                                                       continue;
+                                                                               },
+                                                                       }
+                                                               }
+                                                       }
+                                               }
+                                       }
+
+                                       let mut peer_lock = peer_mutex.lock().unwrap();
+                                       let peer = &mut *peer_lock;
+                                       let mut msg_to_handle = None;
+                                       if peer_node_id.is_none() {
+                                               peer_node_id = peer.their_node_id.clone();
+                                       }
+
                                        assert!(peer.pending_read_buffer.len() > 0);
                                        assert!(peer.pending_read_buffer.len() > peer.pending_read_buffer_pos);
 
-                                       let mut read_pos = 0;
-                                       while read_pos < data.len() {
-                                               {
-                                                       let data_to_copy = cmp::min(peer.pending_read_buffer.len() - peer.pending_read_buffer_pos, data.len() - read_pos);
-                                                       peer.pending_read_buffer[peer.pending_read_buffer_pos..peer.pending_read_buffer_pos + data_to_copy].copy_from_slice(&data[read_pos..read_pos + data_to_copy]);
-                                                       read_pos += data_to_copy;
-                                                       peer.pending_read_buffer_pos += data_to_copy;
+                                       {
+                                               let data_to_copy = cmp::min(peer.pending_read_buffer.len() - peer.pending_read_buffer_pos, data.len() - read_pos);
+                                               peer.pending_read_buffer[peer.pending_read_buffer_pos..peer.pending_read_buffer_pos + data_to_copy].copy_from_slice(&data[read_pos..read_pos + data_to_copy]);
+                                               read_pos += data_to_copy;
+                                               peer.pending_read_buffer_pos += data_to_copy;
+                                       }
+
+                                       if peer.pending_read_buffer_pos == peer.pending_read_buffer.len() {
+                                               peer.pending_read_buffer_pos = 0;
+
+                                               macro_rules! insert_node_id {
+                                                       () => {
+                                                               match self.node_id_to_descriptor.lock().unwrap().entry(peer.their_node_id.unwrap()) {
+                                                                       hash_map::Entry::Occupied(_) => {
+                                                                               log_trace!(self.logger, "Got second connection with {}, closing", log_pubkey!(peer.their_node_id.unwrap()));
+                                                                               peer.their_node_id = None; // Unset so that we don't generate a peer_disconnected event
+                                                                               return Err(PeerHandleError{ no_connection_possible: false })
+                                                                       },
+                                                                       hash_map::Entry::Vacant(entry) => {
+                                                                               log_debug!(self.logger, "Finished noise handshake for connection with {}", log_pubkey!(peer.their_node_id.unwrap()));
+                                                                               entry.insert(peer_descriptor.clone())
+                                                                       },
+                                                               };
+                                                       }
                                                }
 
-                                               if peer.pending_read_buffer_pos == peer.pending_read_buffer.len() {
-                                                       peer.pending_read_buffer_pos = 0;
+                                               let next_step = peer.channel_encryptor.get_noise_step();
+                                               match next_step {
+                                                       NextNoiseStep::ActOne => {
+                                                               let act_two = try_potential_handleerror!(peer,
+                                                                       peer.channel_encryptor.process_act_one_with_keys(&peer.pending_read_buffer[..], &self.our_node_secret, self.get_ephemeral_key())).to_vec();
+                                                               peer.pending_outbound_buffer.push_back(act_two);
+                                                               peer.pending_read_buffer = [0; 66].to_vec(); // act three is 66 bytes long
+                                                       },
+                                                       NextNoiseStep::ActTwo => {
+                                                               let (act_three, their_node_id) = try_potential_handleerror!(peer,
+                                                                       peer.channel_encryptor.process_act_two(&peer.pending_read_buffer[..], &self.our_node_secret));
+                                                               peer.pending_outbound_buffer.push_back(act_three.to_vec());
+                                                               peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
+                                                               peer.pending_read_is_header = true;
+
+                                                               peer.their_node_id = Some(their_node_id);
+                                                               insert_node_id!();
+                                                               let features = InitFeatures::known();
+                                                               let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
+                                                               self.enqueue_message(peer, &resp);
+                                                               peer.awaiting_pong_timer_tick_intervals = 0;
+                                                       },
+                                                       NextNoiseStep::ActThree => {
+                                                               let their_node_id = try_potential_handleerror!(peer,
+                                                                       peer.channel_encryptor.process_act_three(&peer.pending_read_buffer[..]));
+                                                               peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
+                                                               peer.pending_read_is_header = true;
+                                                               peer.their_node_id = Some(their_node_id);
+                                                               insert_node_id!();
+                                                               let features = InitFeatures::known();
+                                                               let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
+                                                               self.enqueue_message(peer, &resp);
+                                                               peer.awaiting_pong_timer_tick_intervals = 0;
+                                                       },
+                                                       NextNoiseStep::NoiseComplete => {
+                                                               if peer.pending_read_is_header {
+                                                                       let msg_len = try_potential_handleerror!(peer,
+                                                                               peer.channel_encryptor.decrypt_length_header(&peer.pending_read_buffer[..]));
+                                                                       peer.pending_read_buffer = Vec::with_capacity(msg_len as usize + 16);
+                                                                       peer.pending_read_buffer.resize(msg_len as usize + 16, 0);
+                                                                       if msg_len < 2 { // Need at least the message type tag
+                                                                               return Err(PeerHandleError{ no_connection_possible: false });
+                                                                       }
+                                                                       peer.pending_read_is_header = false;
+                                                               } else {
+                                                                       let msg_data = try_potential_handleerror!(peer,
+                                                                               peer.channel_encryptor.decrypt_message(&peer.pending_read_buffer[..]));
+                                                                       assert!(msg_data.len() >= 2);
+
+                                                                       // Reset read buffer
+                                                                       peer.pending_read_buffer = [0; 18].to_vec();
+                                                                       peer.pending_read_is_header = true;
 
-                                                       macro_rules! try_potential_handleerror {
-                                                               ($thing: expr) => {
-                                                                       match $thing {
+                                                                       let mut reader = io::Cursor::new(&msg_data[..]);
+                                                                       let message_result = wire::read(&mut reader, &*self.custom_message_handler);
+                                                                       let message = match message_result {
                                                                                Ok(x) => x,
                                                                                Err(e) => {
-                                                                                       match e.action {
-                                                                                               msgs::ErrorAction::DisconnectPeer { msg: _ } => {
-                                                                                                       //TODO: Try to push msg
-                                                                                                       log_debug!(self.logger, "Error handling message; disconnecting peer with: {}", e.err);
-                                                                                                       return Err(PeerHandleError{ no_connection_possible: false });
-                                                                                               },
-                                                                                               msgs::ErrorAction::IgnoreAndLog(level) => {
-                                                                                                       log_given_level!(self.logger, level, "Error handling message; ignoring: {}", e.err);
-                                                                                                       continue
-                                                                                               },
-                                                                                               msgs::ErrorAction::IgnoreError => {
-                                                                                                       log_debug!(self.logger, "Error handling message; ignoring: {}", e.err);
+                                                                                       match e {
+                                                                                               // Note that to avoid recursion we never call
+                                                                                               // `do_attempt_write_data` from here, causing
+                                                                                               // the messages enqueued here to not actually
+                                                                                               // be sent before the peer is disconnected.
+                                                                                               (msgs::DecodeError::UnknownRequiredFeature, Some(ty)) if is_gossip_msg(ty) => {
+                                                                                                       log_gossip!(self.logger, "Got a channel/node announcement with an unknown required feature flag, you may want to update!");
+                                                                                                       continue;
+                                                                                               }
+                                                                                               (msgs::DecodeError::UnsupportedCompression, _) => {
+                                                                                                       log_gossip!(self.logger, "We don't support zlib-compressed message fields, sending a warning and ignoring message");
+                                                                                                       self.enqueue_message(peer, &msgs::WarningMessage { channel_id: [0; 32], data: "Unsupported message compression: zlib".to_owned() });
                                                                                                        continue;
-                                                                                               },
-                                                                                               msgs::ErrorAction::SendErrorMessage { msg } => {
-                                                                                                       log_debug!(self.logger, "Error handling message; sending error message with: {}", e.err);
-                                                                                                       self.enqueue_message(peer, &msg);
+                                                                                               }
+                                                                                               (_, Some(ty)) if is_gossip_msg(ty) => {
+                                                                                                       log_gossip!(self.logger, "Got an invalid value while deserializing a gossip message");
+                                                                                                       self.enqueue_message(peer, &msgs::WarningMessage { channel_id: [0; 32], data: "Unreadable/bogus gossip message".to_owned() });
                                                                                                        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) });
+                                                                                                       return Err(PeerHandleError { no_connection_possible: false });
+                                                                                               }
+                                                                                               (msgs::DecodeError::UnknownVersion, _) => return Err(PeerHandleError { no_connection_possible: false }),
+                                                                                               (msgs::DecodeError::InvalidValue, _) => {
+                                                                                                       log_debug!(self.logger, "Got an invalid value while deserializing message");
+                                                                                                       return Err(PeerHandleError { no_connection_possible: false });
+                                                                                               }
+                                                                                               (msgs::DecodeError::ShortRead, _) => {
+                                                                                                       log_debug!(self.logger, "Deserialization failed due to shortness of message");
+                                                                                                       return Err(PeerHandleError { no_connection_possible: false });
+                                                                                               }
+                                                                                               (msgs::DecodeError::BadLengthDescriptor, _) => return Err(PeerHandleError { no_connection_possible: false }),
+                                                                                               (msgs::DecodeError::Io(_), _) => return Err(PeerHandleError { no_connection_possible: false }),
                                                                                        }
                                                                                }
-                                                                       }
-                                                               }
-                                                       }
-
-                                                       macro_rules! insert_node_id {
-                                                               () => {
-                                                                       match peers.node_id_to_descriptor.entry(peer.their_node_id.unwrap()) {
-                                                                               hash_map::Entry::Occupied(_) => {
-                                                                                       log_trace!(self.logger, "Got second connection with {}, closing", log_pubkey!(peer.their_node_id.unwrap()));
-                                                                                       peer.their_node_id = None; // Unset so that we don't generate a peer_disconnected event
-                                                                                       return Err(PeerHandleError{ no_connection_possible: false })
-                                                                               },
-                                                                               hash_map::Entry::Vacant(entry) => {
-                                                                                       log_debug!(self.logger, "Finished noise handshake for connection with {}", log_pubkey!(peer.their_node_id.unwrap()));
-                                                                                       entry.insert(peer_descriptor.clone())
-                                                                               },
                                                                        };
-                                                               }
-                                                       }
 
-                                                       let next_step = peer.channel_encryptor.get_noise_step();
-                                                       match next_step {
-                                                               NextNoiseStep::ActOne => {
-                                                                       let act_two = try_potential_handleerror!(peer.channel_encryptor.process_act_one_with_keys(&peer.pending_read_buffer[..], &self.our_node_secret, self.get_ephemeral_key())).to_vec();
-                                                                       peer.pending_outbound_buffer.push_back(act_two);
-                                                                       peer.pending_read_buffer = [0; 66].to_vec(); // act three is 66 bytes long
-                                                               },
-                                                               NextNoiseStep::ActTwo => {
-                                                                       let (act_three, their_node_id) = try_potential_handleerror!(peer.channel_encryptor.process_act_two(&peer.pending_read_buffer[..], &self.our_node_secret));
-                                                                       peer.pending_outbound_buffer.push_back(act_three.to_vec());
-                                                                       peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
-                                                                       peer.pending_read_is_header = true;
-
-                                                                       peer.their_node_id = Some(their_node_id);
-                                                                       insert_node_id!();
-                                                                       let features = InitFeatures::known();
-                                                                       let resp = msgs::Init { features };
-                                                                       self.enqueue_message(peer, &resp);
-                                                               },
-                                                               NextNoiseStep::ActThree => {
-                                                                       let their_node_id = try_potential_handleerror!(peer.channel_encryptor.process_act_three(&peer.pending_read_buffer[..]));
-                                                                       peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
-                                                                       peer.pending_read_is_header = true;
-                                                                       peer.their_node_id = Some(their_node_id);
-                                                                       insert_node_id!();
-                                                                       let features = InitFeatures::known();
-                                                                       let resp = msgs::Init { features };
-                                                                       self.enqueue_message(peer, &resp);
-                                                               },
-                                                               NextNoiseStep::NoiseComplete => {
-                                                                       if peer.pending_read_is_header {
-                                                                               let msg_len = try_potential_handleerror!(peer.channel_encryptor.decrypt_length_header(&peer.pending_read_buffer[..]));
-                                                                               peer.pending_read_buffer = Vec::with_capacity(msg_len as usize + 16);
-                                                                               peer.pending_read_buffer.resize(msg_len as usize + 16, 0);
-                                                                               if msg_len < 2 { // Need at least the message type tag
-                                                                                       return Err(PeerHandleError{ no_connection_possible: false });
-                                                                               }
-                                                                               peer.pending_read_is_header = false;
-                                                                       } else {
-                                                                               let msg_data = try_potential_handleerror!(peer.channel_encryptor.decrypt_message(&peer.pending_read_buffer[..]));
-                                                                               assert!(msg_data.len() >= 2);
-
-                                                                               // Reset read buffer
-                                                                               peer.pending_read_buffer = [0; 18].to_vec();
-                                                                               peer.pending_read_is_header = true;
-
-                                                                               let mut reader = io::Cursor::new(&msg_data[..]);
-                                                                               let message_result = wire::read(&mut reader, &*self.custom_message_handler);
-                                                                               let message = match message_result {
-                                                                                       Ok(x) => x,
-                                                                                       Err(e) => {
-                                                                                               match e {
-                                                                                                       msgs::DecodeError::UnknownVersion => return Err(PeerHandleError { no_connection_possible: false }),
-                                                                                                       msgs::DecodeError::UnknownRequiredFeature => {
-                                                                                                               log_trace!(self.logger, "Got a channel/node announcement with an known required feature flag, you may want to update!");
-                                                                                                               continue;
-                                                                                                       }
-                                                                                                       msgs::DecodeError::InvalidValue => {
-                                                                                                               log_debug!(self.logger, "Got an invalid value while deserializing message");
-                                                                                                               return Err(PeerHandleError { no_connection_possible: false });
-                                                                                                       }
-                                                                                                       msgs::DecodeError::ShortRead => {
-                                                                                                               log_debug!(self.logger, "Deserialization failed due to shortness of message");
-                                                                                                               return Err(PeerHandleError { no_connection_possible: false });
-                                                                                                       }
-                                                                                                       msgs::DecodeError::BadLengthDescriptor => return Err(PeerHandleError { no_connection_possible: false }),
-                                                                                                       msgs::DecodeError::Io(_) => return Err(PeerHandleError { no_connection_possible: false }),
-                                                                                                       msgs::DecodeError::UnsupportedCompression => {
-                                                                                                               log_trace!(self.logger, "We don't support zlib-compressed message fields, ignoring message");
-                                                                                                               continue;
-                                                                                                       }
-                                                                                               }
-                                                                                       }
-                                                                               };
-
-                                                                               match self.handle_message(peer, message) {
-                                                                                       Err(handling_error) => match handling_error {
-                                                                                               MessageHandlingError::PeerHandleError(e) => { return Err(e) },
-                                                                                               MessageHandlingError::LightningError(e) => {
-                                                                                                       try_potential_handleerror!(Err(e));
-                                                                                               },
-                                                                                       },
-                                                                                       Ok(Some(msg)) => {
-                                                                                               peer_node_id = Some(peer.their_node_id.expect("After noise is complete, their_node_id is always set"));
-                                                                                               msgs_to_forward.push(msg);
-                                                                                       },
-                                                                                       Ok(None) => {},
-                                                                               }
-                                                                       }
+                                                                       msg_to_handle = Some(message);
                                                                }
                                                        }
                                                }
                                        }
-
-                                       peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_READ_PAUSE // pause_read
+                                       pause_read = peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_READ_PAUSE;
+
+                                       if let Some(message) = msg_to_handle {
+                                               match self.handle_message(&peer_mutex, peer_lock, message) {
+                                                       Err(handling_error) => match handling_error {
+                                                               MessageHandlingError::PeerHandleError(e) => { return Err(e) },
+                                                               MessageHandlingError::LightningError(e) => {
+                                                                       try_potential_handleerror!(&mut peer_mutex.lock().unwrap(), Err(e));
+                                                               },
+                                                       },
+                                                       Ok(Some(msg)) => {
+                                                               msgs_to_forward.push(msg);
+                                                       },
+                                                       Ok(None) => {},
+                                               }
+                                       }
                                }
-                       };
-
-                       for msg in msgs_to_forward.drain(..) {
-                               self.forward_broadcast_msg(peers, &msg, peer_node_id.as_ref());
                        }
+               }
 
-                       pause_read
-               };
+               for msg in msgs_to_forward.drain(..) {
+                       self.forward_broadcast_msg(&*peers, &msg, peer_node_id.as_ref());
+               }
 
                Ok(pause_read)
        }
@@ -915,47 +1060,95 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        /// Returns the message back if it needs to be broadcasted to all other peers.
        fn handle_message(
                &self,
-               peer: &mut Peer,
+               peer_mutex: &Mutex<Peer>,
+               mut peer_lock: MutexGuard<Peer>,
                message: wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>
        ) -> Result<Option<wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>>, MessageHandlingError> {
-               log_trace!(self.logger, "Received message {:?} from {}", message, log_pubkey!(peer.their_node_id.unwrap()));
+               let their_node_id = peer_lock.their_node_id.clone().expect("We know the peer's public key by the time we receive messages");
+               peer_lock.received_message_since_timer_tick = true;
 
                // Need an Init as first message
-               if let wire::Message::Init(_) = message {
-               } else if peer.their_features.is_none() {
-                       log_debug!(self.logger, "Peer {} sent non-Init first message", log_pubkey!(peer.their_node_id.unwrap()));
+               if let wire::Message::Init(msg) = message {
+                       if msg.features.requires_unknown_bits() {
+                               log_debug!(self.logger, "Peer features required unknown version bits");
+                               return Err(PeerHandleError{ no_connection_possible: true }.into());
+                       }
+                       if peer_lock.their_features.is_some() {
+                               return Err(PeerHandleError{ no_connection_possible: false }.into());
+                       }
+
+                       log_info!(self.logger, "Received peer Init message from {}: {}", log_pubkey!(their_node_id), msg.features);
+
+                       // For peers not supporting gossip queries start sync now, otherwise wait until we receive a filter.
+                       if msg.features.initial_routing_sync() && !msg.features.supports_gossip_queries() {
+                               peer_lock.sync_status = InitSyncTracker::ChannelsSyncing(0);
+                       }
+
+                       if !msg.features.supports_static_remote_key() {
+                               log_debug!(self.logger, "Peer {} does not support static remote key, disconnecting with no_connection_possible", log_pubkey!(their_node_id));
+                               return Err(PeerHandleError{ no_connection_possible: true }.into());
+                       }
+
+                       self.message_handler.route_handler.peer_connected(&their_node_id, &msg);
+
+                       self.message_handler.chan_handler.peer_connected(&their_node_id, &msg);
+                       peer_lock.their_features = Some(msg.features);
+                       return Ok(None);
+               } else if peer_lock.their_features.is_none() {
+                       log_debug!(self.logger, "Peer {} sent non-Init first message", log_pubkey!(their_node_id));
                        return Err(PeerHandleError{ no_connection_possible: false }.into());
                }
 
+               if let wire::Message::GossipTimestampFilter(_msg) = message {
+                       // When supporting gossip messages, start inital gossip sync only after we receive
+                       // a GossipTimestampFilter
+                       if peer_lock.their_features.as_ref().unwrap().supports_gossip_queries() &&
+                               !peer_lock.sent_gossip_timestamp_filter {
+                               peer_lock.sent_gossip_timestamp_filter = true;
+                               peer_lock.sync_status = InitSyncTracker::ChannelsSyncing(0);
+                       }
+                       return Ok(None);
+               }
+
+               let their_features = peer_lock.their_features.clone();
+               mem::drop(peer_lock);
+
+               if is_gossip_msg(message.type_id()) {
+                       log_gossip!(self.logger, "Received message {:?} from {}", message, log_pubkey!(their_node_id));
+               } else {
+                       log_trace!(self.logger, "Received message {:?} from {}", message, log_pubkey!(their_node_id));
+               }
+
                let mut should_forward = None;
 
                match message {
                        // Setup and Control messages:
-                       wire::Message::Init(msg) => {
-                               if msg.features.requires_unknown_bits() {
-                                       log_debug!(self.logger, "Peer features required unknown version bits");
-                                       return Err(PeerHandleError{ no_connection_possible: true }.into());
-                               }
-                               if peer.their_features.is_some() {
-                                       return Err(PeerHandleError{ no_connection_possible: false }.into());
+                       wire::Message::Init(_) => {
+                               // Handled above
+                       },
+                       wire::Message::GossipTimestampFilter(_) => {
+                               // 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;
+                                       }
                                }
 
-                               log_info!(self.logger, "Received peer Init message: {}", msg.features);
-
-                               if msg.features.initial_routing_sync() {
-                                       peer.sync_status = InitSyncTracker::ChannelsSyncing(0);
+                               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));
                                }
-                               if !msg.features.supports_static_remote_key() {
-                                       log_debug!(self.logger, "Peer {} does not support static remote key, disconnecting with no_connection_possible", log_pubkey!(peer.their_node_id.unwrap()));
+                               self.message_handler.chan_handler.handle_error(&their_node_id, &msg);
+                               if msg.channel_id == [0; 32] {
                                        return Err(PeerHandleError{ no_connection_possible: true }.into());
                                }
-
-                               self.message_handler.route_handler.sync_routing_table(&peer.their_node_id.unwrap(), &msg);
-
-                               self.message_handler.chan_handler.peer_connected(&peer.their_node_id.unwrap(), &msg);
-                               peer.their_features = Some(msg.features);
                        },
-                       wire::Message::Error(msg) => {
+                       wire::Message::Warning(msg) => {
                                let mut data_is_printable = true;
                                for b in msg.data.bytes() {
                                        if b < 32 || b > 126 {
@@ -965,81 +1158,79 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                }
 
                                if data_is_printable {
-                                       log_debug!(self.logger, "Got Err message from {}: {}", log_pubkey!(peer.their_node_id.unwrap()), msg.data);
+                                       log_debug!(self.logger, "Got warning 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!(peer.their_node_id.unwrap()));
-                               }
-                               self.message_handler.chan_handler.handle_error(&peer.their_node_id.unwrap(), &msg);
-                               if msg.channel_id == [0; 32] {
-                                       return Err(PeerHandleError{ no_connection_possible: true }.into());
+                                       log_debug!(self.logger, "Got warning message from {} with non-ASCII error message", log_pubkey!(their_node_id));
                                }
                        },
 
                        wire::Message::Ping(msg) => {
                                if msg.ponglen < 65532 {
                                        let resp = msgs::Pong { byteslen: msg.ponglen };
-                                       self.enqueue_message(peer, &resp);
+                                       self.enqueue_message(&mut *peer_mutex.lock().unwrap(), &resp);
                                }
                        },
                        wire::Message::Pong(_msg) => {
-                               peer.awaiting_pong = false;
+                               let mut peer_lock = peer_mutex.lock().unwrap();
+                               peer_lock.awaiting_pong_timer_tick_intervals = 0;
+                               peer_lock.msgs_sent_since_pong = 0;
                        },
 
                        // Channel messages:
                        wire::Message::OpenChannel(msg) => {
-                               self.message_handler.chan_handler.handle_open_channel(&peer.their_node_id.unwrap(), peer.their_features.clone().unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_open_channel(&their_node_id, their_features.clone().unwrap(), &msg);
                        },
                        wire::Message::AcceptChannel(msg) => {
-                               self.message_handler.chan_handler.handle_accept_channel(&peer.their_node_id.unwrap(), peer.their_features.clone().unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_accept_channel(&their_node_id, their_features.clone().unwrap(), &msg);
                        },
 
                        wire::Message::FundingCreated(msg) => {
-                               self.message_handler.chan_handler.handle_funding_created(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_funding_created(&their_node_id, &msg);
                        },
                        wire::Message::FundingSigned(msg) => {
-                               self.message_handler.chan_handler.handle_funding_signed(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_funding_signed(&their_node_id, &msg);
                        },
                        wire::Message::FundingLocked(msg) => {
-                               self.message_handler.chan_handler.handle_funding_locked(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_funding_locked(&their_node_id, &msg);
                        },
 
                        wire::Message::Shutdown(msg) => {
-                               self.message_handler.chan_handler.handle_shutdown(&peer.their_node_id.unwrap(), peer.their_features.as_ref().unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_shutdown(&their_node_id, their_features.as_ref().unwrap(), &msg);
                        },
                        wire::Message::ClosingSigned(msg) => {
-                               self.message_handler.chan_handler.handle_closing_signed(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_closing_signed(&their_node_id, &msg);
                        },
 
                        // Commitment messages:
                        wire::Message::UpdateAddHTLC(msg) => {
-                               self.message_handler.chan_handler.handle_update_add_htlc(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_update_add_htlc(&their_node_id, &msg);
                        },
                        wire::Message::UpdateFulfillHTLC(msg) => {
-                               self.message_handler.chan_handler.handle_update_fulfill_htlc(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_update_fulfill_htlc(&their_node_id, &msg);
                        },
                        wire::Message::UpdateFailHTLC(msg) => {
-                               self.message_handler.chan_handler.handle_update_fail_htlc(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_update_fail_htlc(&their_node_id, &msg);
                        },
                        wire::Message::UpdateFailMalformedHTLC(msg) => {
-                               self.message_handler.chan_handler.handle_update_fail_malformed_htlc(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_update_fail_malformed_htlc(&their_node_id, &msg);
                        },
 
                        wire::Message::CommitmentSigned(msg) => {
-                               self.message_handler.chan_handler.handle_commitment_signed(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_commitment_signed(&their_node_id, &msg);
                        },
                        wire::Message::RevokeAndACK(msg) => {
-                               self.message_handler.chan_handler.handle_revoke_and_ack(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_revoke_and_ack(&their_node_id, &msg);
                        },
                        wire::Message::UpdateFee(msg) => {
-                               self.message_handler.chan_handler.handle_update_fee(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_update_fee(&their_node_id, &msg);
                        },
                        wire::Message::ChannelReestablish(msg) => {
-                               self.message_handler.chan_handler.handle_channel_reestablish(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_channel_reestablish(&their_node_id, &msg);
                        },
 
                        // Routing messages:
                        wire::Message::AnnouncementSignatures(msg) => {
-                               self.message_handler.chan_handler.handle_announcement_signatures(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_announcement_signatures(&their_node_id, &msg);
                        },
                        wire::Message::ChannelAnnouncement(msg) => {
                                if self.message_handler.route_handler.handle_channel_announcement(&msg)
@@ -1054,26 +1245,23 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                }
                        },
                        wire::Message::ChannelUpdate(msg) => {
-                               self.message_handler.chan_handler.handle_channel_update(&peer.their_node_id.unwrap(), &msg);
+                               self.message_handler.chan_handler.handle_channel_update(&their_node_id, &msg);
                                if self.message_handler.route_handler.handle_channel_update(&msg)
                                                .map_err(|e| -> MessageHandlingError { e.into() })? {
                                        should_forward = Some(wire::Message::ChannelUpdate(msg));
                                }
                        },
                        wire::Message::QueryShortChannelIds(msg) => {
-                               self.message_handler.route_handler.handle_query_short_channel_ids(&peer.their_node_id.unwrap(), msg)?;
+                               self.message_handler.route_handler.handle_query_short_channel_ids(&their_node_id, msg)?;
                        },
                        wire::Message::ReplyShortChannelIdsEnd(msg) => {
-                               self.message_handler.route_handler.handle_reply_short_channel_ids_end(&peer.their_node_id.unwrap(), msg)?;
+                               self.message_handler.route_handler.handle_reply_short_channel_ids_end(&their_node_id, msg)?;
                        },
                        wire::Message::QueryChannelRange(msg) => {
-                               self.message_handler.route_handler.handle_query_channel_range(&peer.their_node_id.unwrap(), msg)?;
+                               self.message_handler.route_handler.handle_query_channel_range(&their_node_id, msg)?;
                        },
                        wire::Message::ReplyChannelRange(msg) => {
-                               self.message_handler.route_handler.handle_reply_channel_range(&peer.their_node_id.unwrap(), msg)?;
-                       },
-                       wire::Message::GossipTimestampFilter(_msg) => {
-                               // TODO: handle message
+                               self.message_handler.route_handler.handle_reply_channel_range(&their_node_id, msg)?;
                        },
 
                        // Unknown messages:
@@ -1086,25 +1274,28 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                log_trace!(self.logger, "Received unknown odd message of type {}, ignoring", type_id);
                        },
                        wire::Message::Custom(custom) => {
-                               self.custom_message_handler.handle_custom_message(custom, &peer.their_node_id.unwrap())?;
+                               self.custom_message_handler.handle_custom_message(custom, &their_node_id)?;
                        },
                };
                Ok(should_forward)
        }
 
-       fn forward_broadcast_msg(&self, peers: &mut PeerHolder<Descriptor>, msg: &wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>, except_node: Option<&PublicKey>) {
+       fn forward_broadcast_msg(&self, peers: &PeerHolder<Descriptor>, msg: &wire::Message<<<CMH as core::ops::Deref>::Target as wire::CustomMessageReader>::CustomMessage>, except_node: Option<&PublicKey>) {
                match msg {
                        wire::Message::ChannelAnnouncement(ref msg) => {
-                               log_trace!(self.logger, "Sending message to all peers except {:?} or the announced channel's counterparties: {:?}", except_node, msg);
+                               log_gossip!(self.logger, "Sending message to all peers except {:?} or the announced channel's counterparties: {:?}", except_node, msg);
                                let encoded_msg = encode_msg!(msg);
 
-                               for (_, peer) in peers.peers.iter_mut() {
+                               for (_, peer_mutex) in peers.peers.iter() {
+                                       let mut peer = peer_mutex.lock().unwrap();
                                        if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
                                                        !peer.should_forward_channel_announcement(msg.contents.short_channel_id) {
                                                continue
                                        }
-                                       if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP {
-                                               log_trace!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
+                                       if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP
+                                               || peer.msgs_sent_since_pong > BUFFER_DRAIN_MSGS_PER_TICK * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO
+                                       {
+                                               log_gossip!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
                                                continue;
                                        }
                                        if peer.their_node_id.as_ref() == Some(&msg.contents.node_id_1) ||
@@ -1114,20 +1305,23 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                        if except_node.is_some() && peer.their_node_id.as_ref() == except_node {
                                                continue;
                                        }
-                                       peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
+                                       self.enqueue_encoded_message(&mut *peer, &encoded_msg);
                                }
                        },
                        wire::Message::NodeAnnouncement(ref msg) => {
-                               log_trace!(self.logger, "Sending message to all peers except {:?} or the announced node: {:?}", except_node, msg);
+                               log_gossip!(self.logger, "Sending message to all peers except {:?} or the announced node: {:?}", except_node, msg);
                                let encoded_msg = encode_msg!(msg);
 
-                               for (_, peer) in peers.peers.iter_mut() {
+                               for (_, peer_mutex) in peers.peers.iter() {
+                                       let mut peer = peer_mutex.lock().unwrap();
                                        if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
                                                        !peer.should_forward_node_announcement(msg.contents.node_id) {
                                                continue
                                        }
-                                       if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP {
-                                               log_trace!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
+                                       if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP
+                                               || peer.msgs_sent_since_pong > BUFFER_DRAIN_MSGS_PER_TICK * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO
+                                       {
+                                               log_gossip!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
                                                continue;
                                        }
                                        if peer.their_node_id.as_ref() == Some(&msg.contents.node_id) {
@@ -1136,26 +1330,29 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                        if except_node.is_some() && peer.their_node_id.as_ref() == except_node {
                                                continue;
                                        }
-                                       peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
+                                       self.enqueue_encoded_message(&mut *peer, &encoded_msg);
                                }
                        },
                        wire::Message::ChannelUpdate(ref msg) => {
-                               log_trace!(self.logger, "Sending message to all peers except {:?}: {:?}", except_node, msg);
+                               log_gossip!(self.logger, "Sending message to all peers except {:?}: {:?}", except_node, msg);
                                let encoded_msg = encode_msg!(msg);
 
-                               for (_, peer) in peers.peers.iter_mut() {
+                               for (_, peer_mutex) in peers.peers.iter() {
+                                       let mut peer = peer_mutex.lock().unwrap();
                                        if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
                                                        !peer.should_forward_channel_announcement(msg.contents.short_channel_id)  {
                                                continue
                                        }
-                                       if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP {
-                                               log_trace!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
+                                       if peer.pending_outbound_buffer.len() > OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP
+                                               || peer.msgs_sent_since_pong > BUFFER_DRAIN_MSGS_PER_TICK * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO
+                                       {
+                                               log_gossip!(self.logger, "Skipping broadcast message to {:?} as its outbound buffer is full", peer.their_node_id);
                                                continue;
                                        }
                                        if except_node.is_some() && peer.their_node_id.as_ref() == except_node {
                                                continue;
                                        }
-                                       peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
+                                       self.enqueue_encoded_message(&mut *peer, &encoded_msg);
                                }
                        },
                        _ => debug_assert!(false, "We shouldn't attempt to forward anything but gossip messages"),
@@ -1176,27 +1373,40 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
        /// [`send_data`]: SocketDescriptor::send_data
        pub fn process_events(&self) {
+               let _single_processor_lock = self.event_processing_lock.lock().unwrap();
+
+               let mut peers_to_disconnect = HashMap::new();
+               let mut events_generated = self.message_handler.chan_handler.get_and_clear_pending_msg_events();
+               events_generated.append(&mut self.message_handler.route_handler.get_and_clear_pending_msg_events());
+
                {
                        // TODO: There are some DoS attacks here where you can flood someone's outbound send
                        // buffer by doing things like announcing channels on another node. We should be willing to
                        // drop optional-ish messages when send buffers get full!
 
-                       let mut peers_lock = self.peers.lock().unwrap();
-                       let mut events_generated = self.message_handler.chan_handler.get_and_clear_pending_msg_events();
-                       events_generated.append(&mut self.message_handler.route_handler.get_and_clear_pending_msg_events());
-                       let peers = &mut *peers_lock;
+                       let peers_lock = self.peers.read().unwrap();
+                       let peers = &*peers_lock;
                        macro_rules! get_peer_for_forwarding {
                                ($node_id: expr) => {
                                        {
-                                               match peers.node_id_to_descriptor.get($node_id) {
-                                                       Some(descriptor) => match peers.peers.get_mut(&descriptor) {
-                                                               Some(peer) => {
-                                                                       if peer.their_features.is_none() {
+                                               if peers_to_disconnect.get($node_id).is_some() {
+                                                       // If we've "disconnected" this peer, do not send to it.
+                                                       continue;
+                                               }
+                                               let descriptor_opt = self.node_id_to_descriptor.lock().unwrap().get($node_id).cloned();
+                                               match descriptor_opt {
+                                                       Some(descriptor) => match peers.peers.get(&descriptor) {
+                                                               Some(peer_mutex) => {
+                                                                       let peer_lock = peer_mutex.lock().unwrap();
+                                                                       if peer_lock.their_features.is_none() {
                                                                                continue;
                                                                        }
-                                                                       peer
+                                                                       peer_lock
                                                                },
-                                                               None => panic!("Inconsistent peers set state!"),
+                                                               None => {
+                                                                       debug_assert!(false, "Inconsistent peers set state!");
+                                                                       continue;
+                                                               }
                                                        },
                                                        None => {
                                                                continue;
@@ -1211,13 +1421,13 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                                log_debug!(self.logger, "Handling SendAcceptChannel event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.temporary_channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendOpenChannel { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendOpenChannel event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.temporary_channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendFundingCreated { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendFundingCreated event in peer_handler for node {} for channel {} (which becomes {})",
@@ -1226,25 +1436,25 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                                                log_funding_channel_id!(msg.funding_txid, msg.funding_output_index));
                                                // TODO: If the peer is gone we should generate a DiscardFunding event
                                                // indicating to the wallet that they should just throw away this funding transaction
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendFundingSigned { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendFundingSigned event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendFundingLocked { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendFundingLocked event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendAnnouncementSignatures { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendAnnouncementSignatures event in peer_handler for node {} for channel {})",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::UpdateHTLCs { ref node_id, updates: msgs::CommitmentUpdate { ref update_add_htlcs, ref update_fulfill_htlcs, ref update_fail_htlcs, ref update_fail_malformed_htlcs, ref update_fee, ref commitment_signed } } => {
                                                log_debug!(self.logger, "Handling UpdateHTLCs event in peer_handler for node {} with {} adds, {} fulfills, {} fails for channel {}",
@@ -1253,97 +1463,94 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                                                update_fulfill_htlcs.len(),
                                                                update_fail_htlcs.len(),
                                                                log_bytes!(commitment_signed.channel_id));
-                                               let peer = get_peer_for_forwarding!(node_id);
+                                               let mut peer = get_peer_for_forwarding!(node_id);
                                                for msg in update_add_htlcs {
-                                                       self.enqueue_message(peer, msg);
+                                                       self.enqueue_message(&mut *peer, msg);
                                                }
                                                for msg in update_fulfill_htlcs {
-                                                       self.enqueue_message(peer, msg);
+                                                       self.enqueue_message(&mut *peer, msg);
                                                }
                                                for msg in update_fail_htlcs {
-                                                       self.enqueue_message(peer, msg);
+                                                       self.enqueue_message(&mut *peer, msg);
                                                }
                                                for msg in update_fail_malformed_htlcs {
-                                                       self.enqueue_message(peer, msg);
+                                                       self.enqueue_message(&mut *peer, msg);
                                                }
                                                if let &Some(ref msg) = update_fee {
-                                                       self.enqueue_message(peer, msg);
+                                                       self.enqueue_message(&mut *peer, msg);
                                                }
-                                               self.enqueue_message(peer, commitment_signed);
+                                               self.enqueue_message(&mut *peer, commitment_signed);
                                        },
                                        MessageSendEvent::SendRevokeAndACK { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendRevokeAndACK event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendClosingSigned { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendClosingSigned event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendShutdown { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling Shutdown event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendChannelReestablish { ref node_id, ref msg } => {
                                                log_debug!(self.logger, "Handling SendChannelReestablish event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id),
                                                                log_bytes!(msg.channel_id));
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::BroadcastChannelAnnouncement { msg, update_msg } => {
                                                log_debug!(self.logger, "Handling BroadcastChannelAnnouncement event in peer_handler for short channel id {}", msg.contents.short_channel_id);
-                                               if self.message_handler.route_handler.handle_channel_announcement(&msg).is_ok() && self.message_handler.route_handler.handle_channel_update(&update_msg).is_ok() {
-                                                       self.forward_broadcast_msg(peers, &wire::Message::ChannelAnnouncement(msg), None);
-                                                       self.forward_broadcast_msg(peers, &wire::Message::ChannelUpdate(update_msg), None);
+                                               match self.message_handler.route_handler.handle_channel_announcement(&msg) {
+                                                       Ok(_) | Err(LightningError { action: msgs::ErrorAction::IgnoreDuplicateGossip, .. }) =>
+                                                               self.forward_broadcast_msg(peers, &wire::Message::ChannelAnnouncement(msg), None),
+                                                       _ => {},
+                                               }
+                                               match self.message_handler.route_handler.handle_channel_update(&update_msg) {
+                                                       Ok(_) | Err(LightningError { action: msgs::ErrorAction::IgnoreDuplicateGossip, .. }) =>
+                                                               self.forward_broadcast_msg(peers, &wire::Message::ChannelUpdate(update_msg), None),
+                                                       _ => {},
                                                }
                                        },
                                        MessageSendEvent::BroadcastNodeAnnouncement { msg } => {
                                                log_debug!(self.logger, "Handling BroadcastNodeAnnouncement event in peer_handler");
-                                               if self.message_handler.route_handler.handle_node_announcement(&msg).is_ok() {
-                                                       self.forward_broadcast_msg(peers, &wire::Message::NodeAnnouncement(msg), None);
+                                               match self.message_handler.route_handler.handle_node_announcement(&msg) {
+                                                       Ok(_) | Err(LightningError { action: msgs::ErrorAction::IgnoreDuplicateGossip, .. }) =>
+                                                               self.forward_broadcast_msg(peers, &wire::Message::NodeAnnouncement(msg), None),
+                                                       _ => {},
                                                }
                                        },
                                        MessageSendEvent::BroadcastChannelUpdate { msg } => {
                                                log_debug!(self.logger, "Handling BroadcastChannelUpdate event in peer_handler for short channel id {}", msg.contents.short_channel_id);
-                                               if self.message_handler.route_handler.handle_channel_update(&msg).is_ok() {
-                                                       self.forward_broadcast_msg(peers, &wire::Message::ChannelUpdate(msg), None);
+                                               match self.message_handler.route_handler.handle_channel_update(&msg) {
+                                                       Ok(_) | Err(LightningError { action: msgs::ErrorAction::IgnoreDuplicateGossip, .. }) =>
+                                                               self.forward_broadcast_msg(peers, &wire::Message::ChannelUpdate(msg), None),
+                                                       _ => {},
                                                }
                                        },
                                        MessageSendEvent::SendChannelUpdate { ref node_id, ref msg } => {
                                                log_trace!(self.logger, "Handling SendChannelUpdate event in peer_handler for node {} for channel {}",
                                                                log_pubkey!(node_id), msg.contents.short_channel_id);
-                                               let peer = get_peer_for_forwarding!(node_id);
-                                               peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
+                                               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 } => {
-                                                               if let Some(mut descriptor) = peers.node_id_to_descriptor.remove(node_id) {
-                                                                       if let Some(mut peer) = peers.peers.remove(&descriptor) {
-                                                                               if let Some(ref 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...
-                                                                                       self.do_attempt_write_data(&mut descriptor, &mut peer);
-                                                                               } else {
-                                                                                       log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with no message", log_pubkey!(node_id));
-                                                                               }
-                                                                       }
-                                                                       descriptor.disconnect_socket();
-                                                                       self.message_handler.chan_handler.peer_disconnected(&node_id, false);
-                                                               }
+                                                               // 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());
                                                        },
                                                        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));
                                                        },
@@ -1351,34 +1558,73 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                                                log_trace!(self.logger, "Handling SendErrorMessage HandleError event in peer_handler for node {} with message {}",
                                                                                log_pubkey!(node_id),
                                                                                msg.data);
-                                                               self.enqueue_message(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);
                                                        },
                                                }
                                        },
                                        MessageSendEvent::SendChannelRangeQuery { ref node_id, ref msg } => {
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        },
                                        MessageSendEvent::SendShortIdsQuery { ref node_id, ref msg } => {
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        }
                                        MessageSendEvent::SendReplyChannelRange { ref node_id, ref msg } => {
-                                               log_trace!(self.logger, "Handling SendReplyChannelRange event in peer_handler for node {} with num_scids={} first_blocknum={} number_of_blocks={}, sync_complete={}",
+                                               log_gossip!(self.logger, "Handling SendReplyChannelRange event in peer_handler for node {} with num_scids={} first_blocknum={} number_of_blocks={}, sync_complete={}",
                                                        log_pubkey!(node_id),
                                                        msg.short_channel_ids.len(),
                                                        msg.first_blocknum,
                                                        msg.number_of_blocks,
                                                        msg.sync_complete);
-                                               self.enqueue_message(get_peer_for_forwarding!(node_id), msg);
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
+                                       }
+                                       MessageSendEvent::SendGossipTimestampFilter { ref node_id, ref msg } => {
+                                               self.enqueue_message(&mut *get_peer_for_forwarding!(node_id), msg);
                                        }
                                }
                        }
 
                        for (node_id, msg) in self.custom_message_handler.get_and_clear_pending_msg() {
-                               self.enqueue_message(get_peer_for_forwarding!(&node_id), &msg);
+                               if peers_to_disconnect.get(&node_id).is_some() { continue; }
+                               self.enqueue_message(&mut *get_peer_for_forwarding!(&node_id), &msg);
                        }
 
-                       for (descriptor, peer) in peers.peers.iter_mut() {
-                               self.do_attempt_write_data(&mut (*descriptor).clone(), peer);
+                       for (descriptor, peer_mutex) in peers.peers.iter() {
+                               self.do_attempt_write_data(&mut (*descriptor).clone(), &mut *peer_mutex.lock().unwrap());
+                       }
+               }
+               if !peers_to_disconnect.is_empty() {
+                       let mut peers_lock = self.peers.write().unwrap();
+                       let peers = &mut *peers_lock;
+                       for (node_id, msg) in peers_to_disconnect.drain() {
+                               // Note that since we are holding the peers *write* lock we can
+                               // remove from node_id_to_descriptor immediately (as no other
+                               // thread can be holding the peer lock if we have the global write
+                               // lock).
+
+                               if let Some(mut descriptor) = self.node_id_to_descriptor.lock().unwrap().remove(&node_id) {
+                                       if let Some(peer_mutex) = peers.peers.remove(&descriptor) {
+                                               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);
+                                                       let mut peer = peer_mutex.lock().unwrap();
+                                                       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...
+                                                       self.do_attempt_write_data(&mut descriptor, &mut *peer);
+                                               } else {
+                                                       log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with no message", log_pubkey!(node_id));
+                                               }
+                                       }
+                                       descriptor.disconnect_socket();
+                                       self.message_handler.chan_handler.peer_disconnected(&node_id, false);
+                               }
                        }
                }
        }
@@ -1389,7 +1635,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        }
 
        fn disconnect_event_internal(&self, descriptor: &Descriptor, no_connection_possible: bool) {
-               let mut peers = self.peers.lock().unwrap();
+               let mut peers = self.peers.write().unwrap();
                let peer_option = peers.peers.remove(descriptor);
                match peer_option {
                        None => {
@@ -1397,13 +1643,14 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                                // was disconnected, then we told the user to `disconnect_socket()`, then they
                                // called this method. Either way we're disconnected, return.
                        },
-                       Some(peer) => {
+                       Some(peer_lock) => {
+                               let peer = peer_lock.lock().unwrap();
                                match peer.their_node_id {
                                        Some(node_id) => {
                                                log_trace!(self.logger,
                                                        "Handling disconnection of peer {}, with {}future connection to the peer possible.",
                                                        log_pubkey!(node_id), if no_connection_possible { "no " } else { "" });
-                                               peers.node_id_to_descriptor.remove(&node_id);
+                                               self.node_id_to_descriptor.lock().unwrap().remove(&node_id);
                                                self.message_handler.chan_handler.peer_disconnected(&node_id, no_connection_possible);
                                        },
                                        None => {}
@@ -1422,8 +1669,8 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        ///
        /// [`disconnect_socket`]: SocketDescriptor::disconnect_socket
        pub fn disconnect_by_node_id(&self, node_id: PublicKey, no_connection_possible: bool) {
-               let mut peers_lock = self.peers.lock().unwrap();
-               if let Some(mut descriptor) = peers_lock.node_id_to_descriptor.remove(&node_id) {
+               let mut peers_lock = self.peers.write().unwrap();
+               if let Some(mut descriptor) = self.node_id_to_descriptor.lock().unwrap().remove(&node_id) {
                        log_trace!(self.logger, "Disconnecting peer with id {} due to client request", node_id);
                        peers_lock.peers.remove(&descriptor);
                        self.message_handler.chan_handler.peer_disconnected(&node_id, no_connection_possible);
@@ -1431,58 +1678,107 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
                }
        }
 
+       /// Disconnects all currently-connected peers. This is useful on platforms where there may be
+       /// an indication that TCP sockets have stalled even if we weren't around to time them out
+       /// using regular ping/pongs.
+       pub fn disconnect_all_peers(&self) {
+               let mut peers_lock = self.peers.write().unwrap();
+               self.node_id_to_descriptor.lock().unwrap().clear();
+               let peers = &mut *peers_lock;
+               for (mut descriptor, peer) in peers.peers.drain() {
+                       if let Some(node_id) = peer.lock().unwrap().their_node_id {
+                               log_trace!(self.logger, "Disconnecting peer with id {} due to client request to disconnect all peers", node_id);
+                               self.message_handler.chan_handler.peer_disconnected(&node_id, false);
+                       }
+                       descriptor.disconnect_socket();
+               }
+       }
+
+       /// This is called when we're blocked on sending additional gossip messages until we receive a
+       /// pong. If we aren't waiting on a pong, we take this opportunity to send a ping (setting
+       /// `awaiting_pong_timer_tick_intervals` to a special flag value to indicate this).
+       fn maybe_send_extra_ping(&self, peer: &mut Peer) {
+               if peer.awaiting_pong_timer_tick_intervals == 0 {
+                       peer.awaiting_pong_timer_tick_intervals = -1;
+                       let ping = msgs::Ping {
+                               ponglen: 0,
+                               byteslen: 64,
+                       };
+                       self.enqueue_message(peer, &ping);
+               }
+       }
+
        /// Send pings to each peer and disconnect those which did not respond to the last round of
        /// pings.
        ///
-       /// This may be called on any timescale you want, however, roughly once every five to ten
-       /// seconds is preferred. The call rate determines both how often we send a ping to our peers
-       /// and how much time they have to respond before we disconnect them.
+       /// This may be called on any timescale you want, however, roughly once every ten seconds is
+       /// preferred. The call rate determines both how often we send a ping to our peers and how much
+       /// time they have to respond before we disconnect them.
        ///
        /// May call [`send_data`] on all [`SocketDescriptor`]s. Thus, be very careful with reentrancy
        /// issues!
        ///
        /// [`send_data`]: SocketDescriptor::send_data
        pub fn timer_tick_occurred(&self) {
-               let mut peers_lock = self.peers.lock().unwrap();
+               let mut peers_lock = self.peers.write().unwrap();
                {
-                       let peers = &mut *peers_lock;
-                       let node_id_to_descriptor = &mut peers.node_id_to_descriptor;
-                       let peers = &mut peers.peers;
                        let mut descriptors_needing_disconnect = Vec::new();
+                       let peer_count = peers_lock.peers.len();
+
+                       peers_lock.peers.retain(|descriptor, peer_mutex| {
+                               let mut peer = peer_mutex.lock().unwrap();
+                               let mut do_disconnect_peer = false;
+                               if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_node_id.is_none() {
+                                       // The peer needs to complete its handshake before we can exchange messages. We
+                                       // give peers one timer tick to complete handshake, reusing
+                                       // `awaiting_pong_timer_tick_intervals` to track number of timer ticks taken
+                                       // for handshake completion.
+                                       if peer.awaiting_pong_timer_tick_intervals != 0 {
+                                               do_disconnect_peer = true;
+                                       } else {
+                                               peer.awaiting_pong_timer_tick_intervals = 1;
+                                               return true;
+                                       }
+                               }
 
-                       peers.retain(|descriptor, peer| {
-                               if peer.awaiting_pong {
+                               if peer.awaiting_pong_timer_tick_intervals == -1 {
+                                       // Magic value set in `maybe_send_extra_ping`.
+                                       peer.awaiting_pong_timer_tick_intervals = 1;
+                                       peer.received_message_since_timer_tick = false;
+                                       return true;
+                               }
+
+                               if do_disconnect_peer
+                                       || (peer.awaiting_pong_timer_tick_intervals > 0 && !peer.received_message_since_timer_tick)
+                                       || peer.awaiting_pong_timer_tick_intervals as u64 >
+                                               MAX_BUFFER_DRAIN_TICK_INTERVALS_PER_PEER as u64 * peer_count as u64
+                               {
                                        descriptors_needing_disconnect.push(descriptor.clone());
                                        match peer.their_node_id {
                                                Some(node_id) => {
                                                        log_trace!(self.logger, "Disconnecting peer with id {} due to ping timeout", node_id);
-                                                       node_id_to_descriptor.remove(&node_id);
+                                                       self.node_id_to_descriptor.lock().unwrap().remove(&node_id);
                                                        self.message_handler.chan_handler.peer_disconnected(&node_id, false);
                                                }
-                                               None => {
-                                                       // This can't actually happen as we should have hit
-                                                       // is_ready_for_encryption() previously on this same peer.
-                                                       unreachable!();
-                                               },
+                                               None => {},
                                        }
                                        return false;
                                }
+                               peer.received_message_since_timer_tick = false;
 
-                               if !peer.channel_encryptor.is_ready_for_encryption() {
-                                       // The peer needs to complete its handshake before we can exchange messages
+                               if peer.awaiting_pong_timer_tick_intervals > 0 {
+                                       peer.awaiting_pong_timer_tick_intervals += 1;
                                        return true;
                                }
 
+                               peer.awaiting_pong_timer_tick_intervals = 1;
                                let ping = msgs::Ping {
                                        ponglen: 0,
                                        byteslen: 64,
                                };
-                               self.enqueue_message(peer, &ping);
-
-                               let mut descriptor_clone = descriptor.clone();
-                               self.do_attempt_write_data(&mut descriptor_clone, peer);
+                               self.enqueue_message(&mut *peer, &ping);
+                               self.do_attempt_write_data(&mut (descriptor.clone()), &mut *peer);
 
-                               peer.awaiting_pong = true;
                                true
                        });
 
@@ -1493,10 +1789,24 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref, CMH: Deref> P
        }
 }
 
+fn is_gossip_msg(type_id: u16) -> bool {
+       match type_id {
+               msgs::ChannelAnnouncement::TYPE |
+               msgs::ChannelUpdate::TYPE |
+               msgs::NodeAnnouncement::TYPE |
+               msgs::QueryChannelRange::TYPE |
+               msgs::ReplyChannelRange::TYPE |
+               msgs::QueryShortChannelIds::TYPE |
+               msgs::ReplyShortChannelIdsEnd::TYPE => true,
+               _ => false
+       }
+}
+
 #[cfg(test)]
 mod tests {
-       use ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler};
+       use ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor, IgnoringMessageHandler, filter_addresses};
        use ln::msgs;
+       use ln::msgs::NetAddress;
        use util::events;
        use util::test_utils;
 
@@ -1572,13 +1882,15 @@ mod tests {
                let a_id = PublicKey::from_secret_key(&secp_ctx, &peer_a.our_node_secret);
                let mut fd_a = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
                let mut fd_b = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
-               let initial_data = peer_b.new_outbound_connection(a_id, fd_b.clone()).unwrap();
-               peer_a.new_inbound_connection(fd_a.clone()).unwrap();
+               let initial_data = peer_b.new_outbound_connection(a_id, fd_b.clone(), None).unwrap();
+               peer_a.new_inbound_connection(fd_a.clone(), None).unwrap();
                assert_eq!(peer_a.read_event(&mut fd_a, &initial_data).unwrap(), false);
                peer_a.process_events();
                assert_eq!(peer_b.read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
                peer_b.process_events();
                assert_eq!(peer_a.read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
+               peer_a.process_events();
+               assert_eq!(peer_b.read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
                (fd_a.clone(), fd_b.clone())
        }
 
@@ -1590,7 +1902,7 @@ mod tests {
                let chan_handler = test_utils::TestChannelMessageHandler::new();
                let mut peers = create_network(2, &cfgs);
                establish_connection(&peers[0], &peers[1]);
-               assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 1);
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
 
                let secp_ctx = Secp256k1::new();
                let their_id = PublicKey::from_secret_key(&secp_ctx, &peers[1].our_node_secret);
@@ -1603,7 +1915,7 @@ mod tests {
                peers[0].message_handler.chan_handler = &chan_handler;
 
                peers[0].process_events();
-               assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 0);
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 0);
        }
 
        #[test]
@@ -1612,17 +1924,17 @@ mod tests {
                let cfgs = create_peermgr_cfgs(2);
                let peers = create_network(2, &cfgs);
                establish_connection(&peers[0], &peers[1]);
-               assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 1);
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
 
                // peers[0] awaiting_pong is set to true, but the Peer is still connected
                peers[0].timer_tick_occurred();
                peers[0].process_events();
-               assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 1);
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
 
                // Since timer_tick_occurred() is called again when awaiting_pong is true, all Peers are disconnected
                peers[0].timer_tick_occurred();
                peers[0].process_events();
-               assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 0);
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 0);
        }
 
        #[test]
@@ -1641,11 +1953,23 @@ mod tests {
                // than can fit into a peer's buffer).
                let (mut fd_a, mut fd_b) = establish_connection(&peers[0], &peers[1]);
 
-               // Make each peer to read the messages that the other peer just wrote to them.
-               peers[0].process_events();
-               peers[1].read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap();
-               peers[1].process_events();
-               peers[0].read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap();
+               // Make each peer to read the messages that the other peer just wrote to them. Note that
+               // due to the max-message-before-ping limits this may take a few iterations to complete.
+               for _ in 0..150/super::BUFFER_DRAIN_MSGS_PER_TICK + 1 {
+                       peers[1].process_events();
+                       let a_read_data = fd_b.outbound_data.lock().unwrap().split_off(0);
+                       assert!(!a_read_data.is_empty());
+
+                       peers[0].read_event(&mut fd_a, &a_read_data).unwrap();
+                       peers[0].process_events();
+
+                       let b_read_data = fd_a.outbound_data.lock().unwrap().split_off(0);
+                       assert!(!b_read_data.is_empty());
+                       peers[1].read_event(&mut fd_b, &b_read_data).unwrap();
+
+                       peers[0].process_events();
+                       assert_eq!(fd_a.outbound_data.lock().unwrap().len(), 0, "Until A receives data, it shouldn't send more messages");
+               }
 
                // Check that each peer has received the expected number of channel updates and channel
                // announcements.
@@ -1654,4 +1978,133 @@ mod tests {
                assert_eq!(cfgs[1].routing_handler.chan_upds_recvd.load(Ordering::Acquire), 100);
                assert_eq!(cfgs[1].routing_handler.chan_anns_recvd.load(Ordering::Acquire), 50);
        }
+
+       #[test]
+       fn test_handshake_timeout() {
+               // Tests that we time out a peer still waiting on handshake completion after a full timer
+               // tick.
+               let cfgs = create_peermgr_cfgs(2);
+               cfgs[0].routing_handler.request_full_sync.store(true, Ordering::Release);
+               cfgs[1].routing_handler.request_full_sync.store(true, Ordering::Release);
+               let peers = create_network(2, &cfgs);
+
+               let secp_ctx = Secp256k1::new();
+               let a_id = PublicKey::from_secret_key(&secp_ctx, &peers[0].our_node_secret);
+               let mut fd_a = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
+               let mut fd_b = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
+               let initial_data = peers[1].new_outbound_connection(a_id, fd_b.clone(), None).unwrap();
+               peers[0].new_inbound_connection(fd_a.clone(), None).unwrap();
+
+               // If we get a single timer tick before completion, that's fine
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
+               peers[0].timer_tick_occurred();
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 1);
+
+               assert_eq!(peers[0].read_event(&mut fd_a, &initial_data).unwrap(), false);
+               peers[0].process_events();
+               assert_eq!(peers[1].read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
+               peers[1].process_events();
+
+               // ...but if we get a second timer tick, we should disconnect the peer
+               peers[0].timer_tick_occurred();
+               assert_eq!(peers[0].peers.read().unwrap().peers.len(), 0);
+
+               assert!(peers[0].read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).is_err());
+       }
+
+       #[test]
+       fn test_filter_addresses(){
+               // Tests the filter_addresses function.
+
+               // For (10/8)
+               let ip_address = NetAddress::IPv4{addr: [10, 0, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [10, 0, 255, 201], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [10, 255, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (0/8)
+               let ip_address = NetAddress::IPv4{addr: [0, 0, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [0, 0, 255, 187], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [0, 255, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (100.64/10)
+               let ip_address = NetAddress::IPv4{addr: [100, 64, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [100, 78, 255, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [100, 127, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (127/8)
+               let ip_address = NetAddress::IPv4{addr: [127, 0, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [127, 65, 73, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [127, 255, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (169.254/16)
+               let ip_address = NetAddress::IPv4{addr: [169, 254, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [169, 254, 221, 101], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [169, 254, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (172.16/12)
+               let ip_address = NetAddress::IPv4{addr: [172, 16, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [172, 27, 101, 23], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [172, 31, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (192.168/16)
+               let ip_address = NetAddress::IPv4{addr: [192, 168, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [192, 168, 205, 159], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [192, 168, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (192.88.99/24)
+               let ip_address = NetAddress::IPv4{addr: [192, 88, 99, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [192, 88, 99, 140], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv4{addr: [192, 88, 99, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For other IPv4 addresses
+               let ip_address = NetAddress::IPv4{addr: [188, 255, 99, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), Some(ip_address.clone()));
+               let ip_address = NetAddress::IPv4{addr: [123, 8, 129, 14], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), Some(ip_address.clone()));
+               let ip_address = NetAddress::IPv4{addr: [2, 88, 9, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), Some(ip_address.clone()));
+
+               // For (2000::/3)
+               let ip_address = NetAddress::IPv6{addr: [32, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), Some(ip_address.clone()));
+               let ip_address = NetAddress::IPv6{addr: [45, 34, 209, 190, 0, 123, 55, 34, 0, 0, 3, 27, 201, 0, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), Some(ip_address.clone()));
+               let ip_address = NetAddress::IPv6{addr: [63, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), Some(ip_address.clone()));
+
+               // For other IPv6 addresses
+               let ip_address = NetAddress::IPv6{addr: [24, 240, 12, 32, 0, 0, 0, 0, 20, 97, 0, 32, 121, 254, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv6{addr: [68, 23, 56, 63, 0, 0, 2, 7, 75, 109, 0, 39, 0, 0, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+               let ip_address = NetAddress::IPv6{addr: [101, 38, 140, 230, 100, 0, 30, 98, 0, 26, 0, 0, 57, 96, 0, 0], port: 1000};
+               assert_eq!(filter_addresses(Some(ip_address.clone())), None);
+
+               // For (None)
+               assert_eq!(filter_addresses(None), None);
+       }
 }