Merge pull request #646 from naumenkogs/2020-06-router-mpp
[rust-lightning] / lightning / src / routing / network_graph.rs
index cafe4fc10a38f5c51259256c3c87fe6e1248a90b..13dc662642c62ccd8aabc9affd520a9ad927bb2a 100644 (file)
@@ -18,27 +18,36 @@ use bitcoin::hashes::Hash;
 use bitcoin::blockdata::script::Builder;
 use bitcoin::blockdata::transaction::TxOut;
 use bitcoin::blockdata::opcodes;
+use bitcoin::hash_types::BlockHash;
 
 use chain;
 use chain::Access;
 use ln::features::{ChannelFeatures, NodeFeatures};
-use ln::msgs::{DecodeError, ErrorAction, LightningError, RoutingMessageHandler, NetAddress, MAX_VALUE_MSAT};
+use ln::msgs::{DecodeError, ErrorAction, Init, LightningError, RoutingMessageHandler, NetAddress, MAX_VALUE_MSAT};
 use ln::msgs::{ChannelAnnouncement, ChannelUpdate, NodeAnnouncement, OptionalField};
+use ln::msgs::{QueryChannelRange, ReplyChannelRange, QueryShortChannelIds, ReplyShortChannelIdsEnd};
 use ln::msgs;
 use util::ser::{Writeable, Readable, Writer};
 use util::logger::Logger;
+use util::events::{MessageSendEvent, MessageSendEventsProvider};
 
 use std::{cmp, fmt};
 use std::sync::{RwLock, RwLockReadGuard};
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Mutex;
 use std::collections::BTreeMap;
 use std::collections::btree_map::Entry as BtreeEntry;
 use std::ops::Deref;
 use bitcoin::hashes::hex::ToHex;
 
+/// The maximum number of extra bytes which we do not understand in a gossip message before we will
+/// refuse to relay the message.
+const MAX_EXCESS_BYTES_FOR_RELAY: usize = 1024;
+
 /// Represents the network as nodes and channels between them
-#[derive(PartialEq)]
+#[derive(Clone, PartialEq)]
 pub struct NetworkGraph {
+       genesis_hash: BlockHash,
        channels: BTreeMap<u64, ChannelInfo>,
        nodes: BTreeMap<PublicKey, NodeInfo>,
 }
@@ -59,6 +68,7 @@ pub struct NetGraphMsgHandler<C: Deref, L: Deref> where C::Target: chain::Access
        pub network_graph: RwLock<NetworkGraph>,
        chain_access: Option<C>,
        full_syncs_requested: AtomicUsize,
+       pending_events: Mutex<Vec<MessageSendEvent>>,
        logger: L,
 }
 
@@ -68,15 +78,13 @@ impl<C: Deref, L: Deref> NetGraphMsgHandler<C, L> where C::Target: chain::Access
        /// Chain monitor is used to make sure announced channels exist on-chain,
        /// channel data is correct, and that the announcement is signed with
        /// channel owners' keys.
-       pub fn new(chain_access: Option<C>, logger: L) -> Self {
+       pub fn new(genesis_hash: BlockHash, chain_access: Option<C>, logger: L) -> Self {
                NetGraphMsgHandler {
                        secp_ctx: Secp256k1::verification_only(),
-                       network_graph: RwLock::new(NetworkGraph {
-                               channels: BTreeMap::new(),
-                               nodes: BTreeMap::new(),
-                       }),
+                       network_graph: RwLock::new(NetworkGraph::new(genesis_hash)),
                        full_syncs_requested: AtomicUsize::new(0),
                        chain_access,
+                       pending_events: Mutex::new(vec![]),
                        logger,
                }
        }
@@ -89,10 +97,18 @@ impl<C: Deref, L: Deref> NetGraphMsgHandler<C, L> where C::Target: chain::Access
                        network_graph: RwLock::new(network_graph),
                        full_syncs_requested: AtomicUsize::new(0),
                        chain_access,
+                       pending_events: Mutex::new(vec![]),
                        logger,
                }
        }
 
+       /// Adds a provider used to check new announcements. Does not affect
+       /// existing announcements unless they are updated.
+       /// Add, update or remove the provider would replace the current one.
+       pub fn add_chain_access(&mut self, chain_access: Option<C>) {
+               self.chain_access = chain_access;
+       }
+
        /// Take a read lock on the network_graph and return it in the C-bindings
        /// newtype helper. This is likely only useful when called via the C
        /// bindings as you can call `self.network_graph.read().unwrap()` in Rust
@@ -100,6 +116,18 @@ impl<C: Deref, L: Deref> NetGraphMsgHandler<C, L> where C::Target: chain::Access
        pub fn read_locked_graph<'a>(&'a self) -> LockedNetworkGraph<'a> {
                LockedNetworkGraph(self.network_graph.read().unwrap())
        }
+
+       /// Returns true when a full routing table sync should be performed with a peer.
+       fn should_request_full_sync(&self, _node_id: &PublicKey) -> bool {
+               //TODO: Determine whether to request a full sync based on the network map.
+               const FULL_SYNCS_TO_REQUEST: usize = 5;
+               if self.full_syncs_requested.load(Ordering::Acquire) < FULL_SYNCS_TO_REQUEST {
+                       self.full_syncs_requested.fetch_add(1, Ordering::AcqRel);
+                       true
+               } else {
+                       false
+               }
+       }
 }
 
 impl<'a> LockedNetworkGraph<'a> {
@@ -121,52 +149,22 @@ macro_rules! secp_verify_sig {
 
 impl<C: Deref + Sync + Send, L: Deref + Sync + Send> RoutingMessageHandler for NetGraphMsgHandler<C, L> where C::Target: chain::Access, L::Target: Logger {
        fn handle_node_announcement(&self, msg: &msgs::NodeAnnouncement) -> Result<bool, LightningError> {
-               self.network_graph.write().unwrap().update_node_from_announcement(msg, Some(&self.secp_ctx))
+               self.network_graph.write().unwrap().update_node_from_announcement(msg, &self.secp_ctx)?;
+               Ok(msg.contents.excess_data.len() <=  MAX_EXCESS_BYTES_FOR_RELAY &&
+                  msg.contents.excess_address_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY &&
+                  msg.contents.excess_data.len() + msg.contents.excess_address_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY)
        }
 
        fn handle_channel_announcement(&self, msg: &msgs::ChannelAnnouncement) -> Result<bool, LightningError> {
-               if msg.contents.node_id_1 == msg.contents.node_id_2 || msg.contents.bitcoin_key_1 == msg.contents.bitcoin_key_2 {
-                       return Err(LightningError{err: "Channel announcement node had a channel with itself".to_owned(), action: ErrorAction::IgnoreError});
-               }
-
-               let utxo_value = match &self.chain_access {
-                       &None => {
-                               // Tentatively accept, potentially exposing us to DoS attacks
-                               None
-                       },
-                       &Some(ref chain_access) => {
-                               match chain_access.get_utxo(&msg.contents.chain_hash, msg.contents.short_channel_id) {
-                                       Ok(TxOut { value, script_pubkey }) => {
-                                               let expected_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
-                                                                                   .push_slice(&msg.contents.bitcoin_key_1.serialize())
-                                                                                   .push_slice(&msg.contents.bitcoin_key_2.serialize())
-                                                                                   .push_opcode(opcodes::all::OP_PUSHNUM_2)
-                                                                                   .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
-                                               if script_pubkey != expected_script {
-                                                       return Err(LightningError{err: format!("Channel announcement key ({}) didn't match on-chain script ({})", script_pubkey.to_hex(), expected_script.to_hex()), action: ErrorAction::IgnoreError});
-                                               }
-                                               //TODO: Check if value is worth storing, use it to inform routing, and compare it
-                                               //to the new HTLC max field in channel_update
-                                               Some(value)
-                                       },
-                                       Err(chain::AccessError::UnknownChain) => {
-                                               return Err(LightningError{err: format!("Channel announced on an unknown chain ({})", msg.contents.chain_hash.encode().to_hex()), action: ErrorAction::IgnoreError});
-                                       },
-                                       Err(chain::AccessError::UnknownTx) => {
-                                               return Err(LightningError{err: "Channel announced without corresponding UTXO entry".to_owned(), action: ErrorAction::IgnoreError});
-                                       },
-                               }
-                       },
-               };
-               let result = self.network_graph.write().unwrap().update_channel_from_announcement(msg, utxo_value, Some(&self.secp_ctx));
+               self.network_graph.write().unwrap().update_channel_from_announcement(msg, &self.chain_access, &self.secp_ctx)?;
                log_trace!(self.logger, "Added channel_announcement for {}{}", msg.contents.short_channel_id, if !msg.contents.excess_data.is_empty() { " with excess uninterpreted data!" } else { "" });
-               result
+               Ok(msg.contents.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY)
        }
 
        fn handle_htlc_fail_channel_update(&self, update: &msgs::HTLCFailChannelUpdate) {
                match update {
                        &msgs::HTLCFailChannelUpdate::ChannelUpdateMessage { ref msg } => {
-                               let _ = self.network_graph.write().unwrap().update_channel(msg, Some(&self.secp_ctx));
+                               let _ = self.network_graph.write().unwrap().update_channel(msg, &self.secp_ctx);
                        },
                        &msgs::HTLCFailChannelUpdate::ChannelClosed { short_channel_id, is_permanent } => {
                                self.network_graph.write().unwrap().close_channel_from_update(short_channel_id, is_permanent);
@@ -178,7 +176,8 @@ impl<C: Deref + Sync + Send, L: Deref + Sync + Send> RoutingMessageHandler for N
        }
 
        fn handle_channel_update(&self, msg: &msgs::ChannelUpdate) -> Result<bool, LightningError> {
-               self.network_graph.write().unwrap().update_channel(msg, Some(&self.secp_ctx))
+               self.network_graph.write().unwrap().update_channel(msg, &self.secp_ctx)?;
+               Ok(msg.contents.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY)
        }
 
        fn get_next_channel_announcements(&self, starting_point: u64, batch_amount: u8) -> Vec<(ChannelAnnouncement, Option<ChannelUpdate>, Option<ChannelUpdate>)> {
@@ -233,19 +232,117 @@ impl<C: Deref + Sync + Send, L: Deref + Sync + Send> RoutingMessageHandler for N
                result
        }
 
-       fn should_request_full_sync(&self, _node_id: &PublicKey) -> bool {
-               //TODO: Determine whether to request a full sync based on the network map.
-               const FULL_SYNCS_TO_REQUEST: usize = 5;
-               if self.full_syncs_requested.load(Ordering::Acquire) < FULL_SYNCS_TO_REQUEST {
-                       self.full_syncs_requested.fetch_add(1, Ordering::AcqRel);
-                       true
-               } else {
-                       false
+       /// Initiates a stateless sync of routing gossip information with a peer
+       /// using gossip_queries. The default strategy used by this implementation
+       /// is to sync the full block range with several peers.
+       ///
+       /// We should expect one or more reply_channel_range messages in response
+       /// to our query_channel_range. Each reply will enqueue a query_scid message
+       /// to request gossip messages for each channel. The sync is considered complete
+       /// when the final reply_scids_end message is received, though we are not
+       /// tracking this directly.
+       fn sync_routing_table(&self, their_node_id: &PublicKey, init_msg: &Init) {
+
+               // We will only perform a sync with peers that support gossip_queries.
+               if !init_msg.features.supports_gossip_queries() {
+                       return ();
+               }
+
+               // Check if we need to perform a full synchronization with this peer
+               if !self.should_request_full_sync(their_node_id) {
+                       return ();
+               }
+
+               let first_blocknum = 0;
+               let number_of_blocks = 0xffffffff;
+               log_debug!(self.logger, "Sending query_channel_range peer={}, first_blocknum={}, number_of_blocks={}", log_pubkey!(their_node_id), first_blocknum, number_of_blocks);
+               let mut pending_events = self.pending_events.lock().unwrap();
+               pending_events.push(MessageSendEvent::SendChannelRangeQuery {
+                       node_id: their_node_id.clone(),
+                       msg: QueryChannelRange {
+                               chain_hash: self.network_graph.read().unwrap().genesis_hash,
+                               first_blocknum,
+                               number_of_blocks,
+                       },
+               });
+       }
+
+       /// Statelessly processes a reply to a channel range query by immediately
+       /// sending an SCID query with SCIDs in the reply. To keep this handler
+       /// stateless, it does not validate the sequencing of replies for multi-
+       /// reply ranges. It does not validate whether the reply(ies) cover the
+       /// queried range. It also does not filter SCIDs to only those in the
+       /// original query range. We also do not validate that the chain_hash
+       /// matches the chain_hash of the NetworkGraph. Any chan_ann message that
+       /// does not match our chain_hash will be rejected when the announcement is
+       /// processed.
+       fn handle_reply_channel_range(&self, their_node_id: &PublicKey, msg: ReplyChannelRange) -> Result<(), LightningError> {
+               log_debug!(self.logger, "Handling reply_channel_range peer={}, first_blocknum={}, number_of_blocks={}, sync_complete={}, scids={}", log_pubkey!(their_node_id), msg.first_blocknum, msg.number_of_blocks, msg.sync_complete, msg.short_channel_ids.len(),);
+
+               log_debug!(self.logger, "Sending query_short_channel_ids peer={}, batch_size={}", log_pubkey!(their_node_id), msg.short_channel_ids.len());
+               let mut pending_events = self.pending_events.lock().unwrap();
+               pending_events.push(MessageSendEvent::SendShortIdsQuery {
+                       node_id: their_node_id.clone(),
+                       msg: QueryShortChannelIds {
+                               chain_hash: msg.chain_hash,
+                               short_channel_ids: msg.short_channel_ids,
+                       }
+               });
+
+               Ok(())
+       }
+
+       /// When an SCID query is initiated the remote peer will begin streaming
+       /// gossip messages. In the event of a failure, we may have received
+       /// some channel information. Before trying with another peer, the
+       /// caller should update its set of SCIDs that need to be queried.
+       fn handle_reply_short_channel_ids_end(&self, their_node_id: &PublicKey, msg: ReplyShortChannelIdsEnd) -> Result<(), LightningError> {
+               log_debug!(self.logger, "Handling reply_short_channel_ids_end peer={}, full_information={}", log_pubkey!(their_node_id), msg.full_information);
+
+               // If the remote node does not have up-to-date information for the
+               // chain_hash they will set full_information=false. We can fail
+               // the result and try again with a different peer.
+               if !msg.full_information {
+                       return Err(LightningError {
+                               err: String::from("Received reply_short_channel_ids_end with no information"),
+                               action: ErrorAction::IgnoreError
+                       });
                }
+
+               Ok(())
+       }
+
+       fn handle_query_channel_range(&self, _their_node_id: &PublicKey, _msg: QueryChannelRange) -> Result<(), LightningError> {
+               // TODO
+               Err(LightningError {
+                       err: String::from("Not implemented"),
+                       action: ErrorAction::IgnoreError,
+               })
+       }
+
+       fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: QueryShortChannelIds) -> Result<(), LightningError> {
+               // TODO
+               Err(LightningError {
+                       err: String::from("Not implemented"),
+                       action: ErrorAction::IgnoreError,
+               })
        }
 }
 
-#[derive(PartialEq, Debug)]
+impl<C: Deref, L: Deref> MessageSendEventsProvider for NetGraphMsgHandler<C, L>
+where
+       C::Target: chain::Access,
+       L::Target: Logger,
+{
+       fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {
+               let mut ret = Vec::new();
+               let mut pending_events = self.pending_events.lock().unwrap();
+               std::mem::swap(&mut ret, &mut pending_events);
+               ret
+       }
+}
+
+#[derive(Clone, Debug, PartialEq)]
 /// Details about one direction of a channel. Received
 /// within a channel update.
 pub struct DirectionalChannelInfo {
@@ -286,7 +383,7 @@ impl_writeable!(DirectionalChannelInfo, 0, {
        last_update_message
 });
 
-#[derive(PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 /// Details about a channel (both directions).
 /// Received within a channel announcement.
 pub struct ChannelInfo {
@@ -357,7 +454,7 @@ impl Writeable for RoutingFees {
        }
 }
 
-#[derive(PartialEq, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 /// Information received in the latest node_announcement from this node.
 pub struct NodeAnnouncementInfo {
        /// Protocol features the node announced support for
@@ -423,7 +520,7 @@ impl Readable for NodeAnnouncementInfo {
        }
 }
 
-#[derive(PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 /// Details about a node in the network, known from the network announcement.
 pub struct NodeInfo {
        /// All valid channels a node has announced
@@ -479,6 +576,7 @@ impl Readable for NodeInfo {
 
 impl Writeable for NetworkGraph {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+               self.genesis_hash.write(writer)?;
                (self.channels.len() as u64).write(writer)?;
                for (ref chan_id, ref chan_info) in self.channels.iter() {
                        (*chan_id).write(writer)?;
@@ -495,6 +593,7 @@ impl Writeable for NetworkGraph {
 
 impl Readable for NetworkGraph {
        fn read<R: ::std::io::Read>(reader: &mut R) -> Result<NetworkGraph, DecodeError> {
+               let genesis_hash: BlockHash = Readable::read(reader)?;
                let channels_count: u64 = Readable::read(reader)?;
                let mut channels = BTreeMap::new();
                for _ in 0..channels_count {
@@ -510,6 +609,7 @@ impl Readable for NetworkGraph {
                        nodes.insert(node_id, node_info);
                }
                Ok(NetworkGraph {
+                       genesis_hash,
                        channels,
                        nodes,
                })
@@ -518,13 +618,13 @@ impl Readable for NetworkGraph {
 
 impl fmt::Display for NetworkGraph {
        fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-               write!(f, "Network map\n[Channels]\n")?;
+               writeln!(f, "Network map\n[Channels]")?;
                for (key, val) in self.channels.iter() {
-                       write!(f, " {}: {}\n", key, val)?;
+                       writeln!(f, " {}: {}", key, val)?;
                }
-               write!(f, "[Nodes]\n")?;
+               writeln!(f, "[Nodes]")?;
                for (key, val) in self.nodes.iter() {
-                       write!(f, " {}: {}\n", log_pubkey!(key), val)?;
+                       writeln!(f, " {}: {}", log_pubkey!(key), val)?;
                }
                Ok(())
        }
@@ -555,73 +655,145 @@ impl NetworkGraph {
        }
 
        /// Creates a new, empty, network graph.
-       pub fn new() -> NetworkGraph {
+       pub fn new(genesis_hash: BlockHash) -> NetworkGraph {
                Self {
+                       genesis_hash,
                        channels: BTreeMap::new(),
                        nodes: BTreeMap::new(),
                }
        }
 
-       /// For an already known node (from channel announcements), update its stored properties from a given node announcement
-       /// Announcement signatures are checked here only if Secp256k1 object is provided.
-       fn update_node_from_announcement(&mut self, msg: &msgs::NodeAnnouncement, secp_ctx: Option<&Secp256k1<secp256k1::VerifyOnly>>) -> Result<bool, LightningError> {
-               if let Some(sig_verifier) = secp_ctx {
-                       let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.contents.encode()[..])[..]);
-                       secp_verify_sig!(sig_verifier, &msg_hash, &msg.signature, &msg.contents.node_id);
-               }
+       /// For an already known node (from channel announcements), update its stored properties from a
+       /// given node announcement.
+       ///
+       /// You probably don't want to call this directly, instead relying on a NetGraphMsgHandler's
+       /// RoutingMessageHandler implementation to call it indirectly. This may be useful to accept
+       /// routing messages from a source using a protocol other than the lightning P2P protocol.
+       pub fn update_node_from_announcement<T: secp256k1::Verification>(&mut self, msg: &msgs::NodeAnnouncement, secp_ctx: &Secp256k1<T>) -> Result<(), LightningError> {
+               let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.contents.encode()[..])[..]);
+               secp_verify_sig!(secp_ctx, &msg_hash, &msg.signature, &msg.contents.node_id);
+               self.update_node_from_announcement_intern(&msg.contents, Some(&msg))
+       }
 
-               match self.nodes.get_mut(&msg.contents.node_id) {
+       /// For an already known node (from channel announcements), update its stored properties from a
+       /// given node announcement without verifying the associated signatures. Because we aren't
+       /// given the associated signatures here we cannot relay the node announcement to any of our
+       /// peers.
+       pub fn update_node_from_unsigned_announcement(&mut self, msg: &msgs::UnsignedNodeAnnouncement) -> Result<(), LightningError> {
+               self.update_node_from_announcement_intern(msg, None)
+       }
+
+       fn update_node_from_announcement_intern(&mut self, msg: &msgs::UnsignedNodeAnnouncement, full_msg: Option<&msgs::NodeAnnouncement>) -> Result<(), LightningError> {
+               match self.nodes.get_mut(&msg.node_id) {
                        None => Err(LightningError{err: "No existing channels for node_announcement".to_owned(), action: ErrorAction::IgnoreError}),
                        Some(node) => {
                                if let Some(node_info) = node.announcement_info.as_ref() {
-                                       if node_info.last_update  >= msg.contents.timestamp {
+                                       if node_info.last_update  >= msg.timestamp {
                                                return Err(LightningError{err: "Update older than last processed update".to_owned(), action: ErrorAction::IgnoreError});
                                        }
                                }
 
-                               let should_relay = msg.contents.excess_data.is_empty() && msg.contents.excess_address_data.is_empty();
+                               let should_relay =
+                                       msg.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY &&
+                                       msg.excess_address_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY &&
+                                       msg.excess_data.len() + msg.excess_address_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY;
                                node.announcement_info = Some(NodeAnnouncementInfo {
-                                       features: msg.contents.features.clone(),
-                                       last_update: msg.contents.timestamp,
-                                       rgb: msg.contents.rgb,
-                                       alias: msg.contents.alias,
-                                       addresses: msg.contents.addresses.clone(),
-                                       announcement_message: if should_relay { Some(msg.clone()) } else { None },
+                                       features: msg.features.clone(),
+                                       last_update: msg.timestamp,
+                                       rgb: msg.rgb,
+                                       alias: msg.alias,
+                                       addresses: msg.addresses.clone(),
+                                       announcement_message: if should_relay { full_msg.cloned() } else { None },
                                });
 
-                               Ok(should_relay)
+                               Ok(())
                        }
                }
        }
 
-       /// For a new or already known (from previous announcement) channel, store or update channel info.
-       /// Also store nodes (if not stored yet) the channel is between, and make node aware of this channel.
-       /// Checking utxo on-chain is useful if we receive an update for already known channel id,
-       /// which is probably result of a reorg. In that case, we update channel info only if the
-       /// utxo was checked, otherwise stick to the existing update, to prevent DoS risks.
-       /// Announcement signatures are checked here only if Secp256k1 object is provided.
-       fn update_channel_from_announcement(&mut self, msg: &msgs::ChannelAnnouncement, utxo_value: Option<u64>, secp_ctx: Option<&Secp256k1<secp256k1::VerifyOnly>>) -> Result<bool, LightningError> {
-               if let Some(sig_verifier) = secp_ctx {
-                       let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.contents.encode()[..])[..]);
-                       secp_verify_sig!(sig_verifier, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
-                       secp_verify_sig!(sig_verifier, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
-                       secp_verify_sig!(sig_verifier, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
-                       secp_verify_sig!(sig_verifier, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
+       /// Store or update channel info from a channel announcement.
+       ///
+       /// You probably don't want to call this directly, instead relying on a NetGraphMsgHandler's
+       /// RoutingMessageHandler implementation to call it indirectly. This may be useful to accept
+       /// routing messages from a source using a protocol other than the lightning P2P protocol.
+       ///
+       /// If a `chain::Access` object is provided via `chain_access`, it will be called to verify
+       /// the corresponding UTXO exists on chain and is correctly-formatted.
+       pub fn update_channel_from_announcement<T: secp256k1::Verification, C: Deref>
+                       (&mut self, msg: &msgs::ChannelAnnouncement, chain_access: &Option<C>, secp_ctx: &Secp256k1<T>)
+                       -> Result<(), LightningError>
+                       where C::Target: chain::Access {
+               let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.contents.encode()[..])[..]);
+               secp_verify_sig!(secp_ctx, &msg_hash, &msg.node_signature_1, &msg.contents.node_id_1);
+               secp_verify_sig!(secp_ctx, &msg_hash, &msg.node_signature_2, &msg.contents.node_id_2);
+               secp_verify_sig!(secp_ctx, &msg_hash, &msg.bitcoin_signature_1, &msg.contents.bitcoin_key_1);
+               secp_verify_sig!(secp_ctx, &msg_hash, &msg.bitcoin_signature_2, &msg.contents.bitcoin_key_2);
+               self.update_channel_from_unsigned_announcement_intern(&msg.contents, Some(msg), chain_access)
+       }
+
+       /// Store or update channel info from a channel announcement without verifying the associated
+       /// signatures. Because we aren't given the associated signatures here we cannot relay the
+       /// channel announcement to any of our peers.
+       ///
+       /// If a `chain::Access` object is provided via `chain_access`, it will be called to verify
+       /// the corresponding UTXO exists on chain and is correctly-formatted.
+       pub fn update_channel_from_unsigned_announcement<C: Deref>
+                       (&mut self, msg: &msgs::UnsignedChannelAnnouncement, chain_access: &Option<C>)
+                       -> Result<(), LightningError>
+                       where C::Target: chain::Access {
+               self.update_channel_from_unsigned_announcement_intern(msg, None, chain_access)
+       }
+
+       fn update_channel_from_unsigned_announcement_intern<C: Deref>
+                       (&mut self, msg: &msgs::UnsignedChannelAnnouncement, full_msg: Option<&msgs::ChannelAnnouncement>, chain_access: &Option<C>)
+                       -> Result<(), LightningError>
+                       where C::Target: chain::Access {
+               if msg.node_id_1 == msg.node_id_2 || msg.bitcoin_key_1 == msg.bitcoin_key_2 {
+                       return Err(LightningError{err: "Channel announcement node had a channel with itself".to_owned(), action: ErrorAction::IgnoreError});
                }
 
-               let should_relay = msg.contents.excess_data.is_empty();
+               let utxo_value = match &chain_access {
+                       &None => {
+                               // Tentatively accept, potentially exposing us to DoS attacks
+                               None
+                       },
+                       &Some(ref chain_access) => {
+                               match chain_access.get_utxo(&msg.chain_hash, msg.short_channel_id) {
+                                       Ok(TxOut { value, script_pubkey }) => {
+                                               let expected_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
+                                                                                   .push_slice(&msg.bitcoin_key_1.serialize())
+                                                                                   .push_slice(&msg.bitcoin_key_2.serialize())
+                                                                                   .push_opcode(opcodes::all::OP_PUSHNUM_2)
+                                                                                   .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
+                                               if script_pubkey != expected_script {
+                                                       return Err(LightningError{err: format!("Channel announcement key ({}) didn't match on-chain script ({})", script_pubkey.to_hex(), expected_script.to_hex()), action: ErrorAction::IgnoreError});
+                                               }
+                                               //TODO: Check if value is worth storing, use it to inform routing, and compare it
+                                               //to the new HTLC max field in channel_update
+                                               Some(value)
+                                       },
+                                       Err(chain::AccessError::UnknownChain) => {
+                                               return Err(LightningError{err: format!("Channel announced on an unknown chain ({})", msg.chain_hash.encode().to_hex()), action: ErrorAction::IgnoreError});
+                                       },
+                                       Err(chain::AccessError::UnknownTx) => {
+                                               return Err(LightningError{err: "Channel announced without corresponding UTXO entry".to_owned(), action: ErrorAction::IgnoreError});
+                                       },
+                               }
+                       },
+               };
 
                let chan_info = ChannelInfo {
-                               features: msg.contents.features.clone(),
-                               node_one: msg.contents.node_id_1.clone(),
+                               features: msg.features.clone(),
+                               node_one: msg.node_id_1.clone(),
                                one_to_two: None,
-                               node_two: msg.contents.node_id_2.clone(),
+                               node_two: msg.node_id_2.clone(),
                                two_to_one: None,
                                capacity_sats: utxo_value,
-                               announcement_message: if should_relay { Some(msg.clone()) } else { None },
+                               announcement_message: if msg.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY
+                                       { full_msg.cloned() } else { None },
                        };
 
-               match self.channels.entry(msg.contents.short_channel_id) {
+               match self.channels.entry(msg.short_channel_id) {
                        BtreeEntry::Occupied(mut entry) => {
                                //TODO: because asking the blockchain if short_channel_id is valid is only optional
                                //in the blockchain API, we need to handle it smartly here, though it's unclear
@@ -635,7 +807,7 @@ impl NetworkGraph {
                                        // b) we don't track UTXOs of channels we know about and remove them if they
                                        //    get reorg'd out.
                                        // c) it's unclear how to do so without exposing ourselves to massive DoS risk.
-                                       Self::remove_channel_in_nodes(&mut self.nodes, &entry.get(), msg.contents.short_channel_id);
+                                       Self::remove_channel_in_nodes(&mut self.nodes, &entry.get(), msg.short_channel_id);
                                        *entry.get_mut() = chan_info;
                                } else {
                                        return Err(LightningError{err: "Already have knowledge of channel".to_owned(), action: ErrorAction::IgnoreError})
@@ -650,11 +822,11 @@ impl NetworkGraph {
                        ( $node_id: expr ) => {
                                match self.nodes.entry($node_id) {
                                        BtreeEntry::Occupied(node_entry) => {
-                                               node_entry.into_mut().channels.push(msg.contents.short_channel_id);
+                                               node_entry.into_mut().channels.push(msg.short_channel_id);
                                        },
                                        BtreeEntry::Vacant(node_entry) => {
                                                node_entry.insert(NodeInfo {
-                                                       channels: vec!(msg.contents.short_channel_id),
+                                                       channels: vec!(msg.short_channel_id),
                                                        lowest_inbound_channel_fees: None,
                                                        announcement_info: None,
                                                });
@@ -663,10 +835,10 @@ impl NetworkGraph {
                        };
                }
 
-               add_channel_to_node!(msg.contents.node_id_1);
-               add_channel_to_node!(msg.contents.node_id_2);
+               add_channel_to_node!(msg.node_id_1);
+               add_channel_to_node!(msg.node_id_2);
 
-               Ok(should_relay)
+               Ok(())
        }
 
        /// Close a channel if a corresponding HTLC fail was sent.
@@ -698,17 +870,32 @@ impl NetworkGraph {
                }
        }
 
-       /// For an already known (from announcement) channel, update info about one of the directions of a channel.
-       /// Announcement signatures are checked here only if Secp256k1 object is provided.
-       fn update_channel(&mut self, msg: &msgs::ChannelUpdate, secp_ctx: Option<&Secp256k1<secp256k1::VerifyOnly>>) -> Result<bool, LightningError> {
+       /// For an already known (from announcement) channel, update info about one of the directions
+       /// of the channel.
+       ///
+       /// You probably don't want to call this directly, instead relying on a NetGraphMsgHandler's
+       /// RoutingMessageHandler implementation to call it indirectly. This may be useful to accept
+       /// routing messages from a source using a protocol other than the lightning P2P protocol.
+       pub fn update_channel<T: secp256k1::Verification>(&mut self, msg: &msgs::ChannelUpdate, secp_ctx: &Secp256k1<T>) -> Result<(), LightningError> {
+               self.update_channel_intern(&msg.contents, Some(&msg), Some((&msg.signature, secp_ctx)))
+       }
+
+       /// For an already known (from announcement) channel, update info about one of the directions
+       /// of the channel without verifying the associated signatures. Because we aren't given the
+       /// associated signatures here we cannot relay the channel update to any of our peers.
+       pub fn update_channel_unsigned(&mut self, msg: &msgs::UnsignedChannelUpdate) -> Result<(), LightningError> {
+               self.update_channel_intern(msg, None, None::<(&secp256k1::Signature, &Secp256k1<secp256k1::VerifyOnly>)>)
+       }
+
+       fn update_channel_intern<T: secp256k1::Verification>(&mut self, msg: &msgs::UnsignedChannelUpdate, full_msg: Option<&msgs::ChannelUpdate>, sig_info: Option<(&secp256k1::Signature, &Secp256k1<T>)>) -> Result<(), LightningError> {
                let dest_node_id;
-               let chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
+               let chan_enabled = msg.flags & (1 << 1) != (1 << 1);
                let chan_was_enabled;
 
-               match self.channels.get_mut(&msg.contents.short_channel_id) {
+               match self.channels.get_mut(&msg.short_channel_id) {
                        None => return Err(LightningError{err: "Couldn't find channel for update".to_owned(), action: ErrorAction::IgnoreError}),
                        Some(channel) => {
-                               if let OptionalField::Present(htlc_maximum_msat) = msg.contents.htlc_maximum_msat {
+                               if let OptionalField::Present(htlc_maximum_msat) = msg.htlc_maximum_msat {
                                        if htlc_maximum_msat > MAX_VALUE_MSAT {
                                                return Err(LightningError{err: "htlc_maximum_msat is larger than maximum possible msats".to_owned(), action: ErrorAction::IgnoreError});
                                        }
@@ -716,15 +903,15 @@ impl NetworkGraph {
                                        if let Some(capacity_sats) = channel.capacity_sats {
                                                // It's possible channel capacity is available now, although it wasn't available at announcement (so the field is None).
                                                // Don't query UTXO set here to reduce DoS risks.
-                                               if htlc_maximum_msat > capacity_sats * 1000 {
-                                                       return Err(LightningError{err: "htlc_maximum_msat is larger than channel capacity".to_owned(), action: ErrorAction::IgnoreError});
+                                               if capacity_sats > MAX_VALUE_MSAT / 1000 || htlc_maximum_msat > capacity_sats * 1000 {
+                                                       return Err(LightningError{err: "htlc_maximum_msat is larger than channel capacity or capacity is bogus".to_owned(), action: ErrorAction::IgnoreError});
                                                }
                                        }
                                }
                                macro_rules! maybe_update_channel_info {
                                        ( $target: expr, $src_node: expr) => {
                                                if let Some(existing_chan_info) = $target.as_ref() {
-                                                       if existing_chan_info.last_update >= msg.contents.timestamp {
+                                                       if existing_chan_info.last_update >= msg.timestamp {
                                                                return Err(LightningError{err: "Update older than last processed update".to_owned(), action: ErrorAction::IgnoreError});
                                                        }
                                                        chan_was_enabled = existing_chan_info.enabled;
@@ -732,21 +919,18 @@ impl NetworkGraph {
                                                        chan_was_enabled = false;
                                                }
 
-                                               let last_update_message = if msg.contents.excess_data.is_empty() {
-                                                       Some(msg.clone())
-                                               } else {
-                                                       None
-                                               };
+                                               let last_update_message = if msg.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY
+                                                       { full_msg.cloned() } else { None };
 
                                                let updated_channel_dir_info = DirectionalChannelInfo {
                                                        enabled: chan_enabled,
-                                                       last_update: msg.contents.timestamp,
-                                                       cltv_expiry_delta: msg.contents.cltv_expiry_delta,
-                                                       htlc_minimum_msat: msg.contents.htlc_minimum_msat,
-                                                       htlc_maximum_msat: if let OptionalField::Present(max_value) = msg.contents.htlc_maximum_msat { Some(max_value) } else { None },
+                                                       last_update: msg.timestamp,
+                                                       cltv_expiry_delta: msg.cltv_expiry_delta,
+                                                       htlc_minimum_msat: msg.htlc_minimum_msat,
+                                                       htlc_maximum_msat: if let OptionalField::Present(max_value) = msg.htlc_maximum_msat { Some(max_value) } else { None },
                                                        fees: RoutingFees {
-                                                               base_msat: msg.contents.fee_base_msat,
-                                                               proportional_millionths: msg.contents.fee_proportional_millionths,
+                                                               base_msat: msg.fee_base_msat,
+                                                               proportional_millionths: msg.fee_proportional_millionths,
                                                        },
                                                        last_update_message
                                                };
@@ -754,17 +938,17 @@ impl NetworkGraph {
                                        }
                                }
 
-                               let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.contents.encode()[..])[..]);
-                               if msg.contents.flags & 1 == 1 {
+                               let msg_hash = hash_to_message!(&Sha256dHash::hash(&msg.encode()[..])[..]);
+                               if msg.flags & 1 == 1 {
                                        dest_node_id = channel.node_one.clone();
-                                       if let Some(sig_verifier) = secp_ctx {
-                                               secp_verify_sig!(sig_verifier, &msg_hash, &msg.signature, &channel.node_two);
+                                       if let Some((sig, ctx)) = sig_info {
+                                               secp_verify_sig!(ctx, &msg_hash, &sig, &channel.node_two);
                                        }
                                        maybe_update_channel_info!(channel.two_to_one, channel.node_two);
                                } else {
                                        dest_node_id = channel.node_two.clone();
-                                       if let Some(sig_verifier) = secp_ctx {
-                                               secp_verify_sig!(sig_verifier, &msg_hash, &msg.signature, &channel.node_one);
+                                       if let Some((sig, ctx)) = sig_info {
+                                               secp_verify_sig!(ctx, &msg_hash, &sig, &channel.node_one);
                                        }
                                        maybe_update_channel_info!(channel.one_to_two, channel.node_one);
                                }
@@ -773,8 +957,8 @@ impl NetworkGraph {
 
                if chan_enabled {
                        let node = self.nodes.get_mut(&dest_node_id).unwrap();
-                       let mut base_msat = msg.contents.fee_base_msat;
-                       let mut proportional_millionths = msg.contents.fee_proportional_millionths;
+                       let mut base_msat = msg.fee_base_msat;
+                       let mut proportional_millionths = msg.fee_proportional_millionths;
                        if let Some(fees) = node.lowest_inbound_channel_fees {
                                base_msat = cmp::min(base_msat, fees.base_msat);
                                proportional_millionths = cmp::min(proportional_millionths, fees.proportional_millionths);
@@ -808,7 +992,7 @@ impl NetworkGraph {
                        node.lowest_inbound_channel_fees = lowest_inbound_channel_fees;
                }
 
-               Ok(msg.contents.excess_data.is_empty())
+               Ok(())
        }
 
        fn remove_channel_in_nodes(nodes: &mut BTreeMap<PublicKey, NodeInfo>, chan: &ChannelInfo, short_channel_id: u64) {
@@ -835,14 +1019,15 @@ impl NetworkGraph {
 #[cfg(test)]
 mod tests {
        use chain;
-       use ln::features::{ChannelFeatures, NodeFeatures};
-       use routing::network_graph::{NetGraphMsgHandler, NetworkGraph};
-       use ln::msgs::{OptionalField, RoutingMessageHandler, UnsignedNodeAnnouncement, NodeAnnouncement,
+       use ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
+       use routing::network_graph::{NetGraphMsgHandler, NetworkGraph, MAX_EXCESS_BYTES_FOR_RELAY};
+       use ln::msgs::{Init, OptionalField, RoutingMessageHandler, UnsignedNodeAnnouncement, NodeAnnouncement,
                UnsignedChannelAnnouncement, ChannelAnnouncement, UnsignedChannelUpdate, ChannelUpdate, HTLCFailChannelUpdate,
-               MAX_VALUE_MSAT};
+               ReplyChannelRange, ReplyShortChannelIdsEnd, QueryChannelRange, QueryShortChannelIds, MAX_VALUE_MSAT};
        use util::test_utils;
        use util::logger::Logger;
        use util::ser::{Readable, Writeable};
+       use util::events::{MessageSendEvent, MessageSendEventsProvider};
 
        use bitcoin::hashes::sha256d::Hash as Sha256dHash;
        use bitcoin::hashes::Hash;
@@ -862,7 +1047,8 @@ mod tests {
        fn create_net_graph_msg_handler() -> (Secp256k1<All>, NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>) {
                let secp_ctx = Secp256k1::new();
                let logger = Arc::new(test_utils::TestLogger::new());
-               let net_graph_msg_handler = NetGraphMsgHandler::new(None, Arc::clone(&logger));
+               let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
+               let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_hash, None, Arc::clone(&logger));
                (secp_ctx, net_graph_msg_handler)
        }
 
@@ -956,7 +1142,7 @@ mod tests {
                };
 
                unsigned_announcement.timestamp += 1000;
-               unsigned_announcement.excess_data.push(1);
+               unsigned_announcement.excess_data.resize(MAX_EXCESS_BYTES_FOR_RELAY + 1, 0);
                msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
                let announcement_with_data = NodeAnnouncement {
                        signature: secp_ctx.sign(&msghash, node_1_privkey),
@@ -1023,7 +1209,7 @@ mod tests {
                };
 
                // Test if the UTXO lookups were not supported
-               let mut net_graph_msg_handler = NetGraphMsgHandler::new(None, Arc::clone(&logger));
+               let mut net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), None, Arc::clone(&logger));
                match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
                        Ok(res) => assert!(res),
                        _ => panic!()
@@ -1047,7 +1233,7 @@ mod tests {
                // Test if an associated transaction were not on-chain (or not confirmed).
                let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
                *chain_source.utxo_ret.lock().unwrap() = Err(chain::AccessError::UnknownTx);
-               net_graph_msg_handler = NetGraphMsgHandler::new(Some(chain_source.clone()), Arc::clone(&logger));
+               net_graph_msg_handler = NetGraphMsgHandler::new(chain_source.clone().genesis_hash, Some(chain_source.clone()), Arc::clone(&logger));
                unsigned_announcement.short_channel_id += 1;
 
                msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
@@ -1124,7 +1310,7 @@ mod tests {
 
                // Don't relay valid channels with excess data
                unsigned_announcement.short_channel_id += 1;
-               unsigned_announcement.excess_data.push(1);
+               unsigned_announcement.excess_data.resize(MAX_EXCESS_BYTES_FOR_RELAY + 1, 0);
                msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
                let valid_announcement = ChannelAnnouncement {
                        node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
@@ -1154,8 +1340,8 @@ mod tests {
                unsigned_announcement.node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
                msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
                let channel_to_itself_announcement = ChannelAnnouncement {
-                       node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
-                       node_signature_2: secp_ctx.sign(&msghash, node_1_privkey),
+                       node_signature_1: secp_ctx.sign(&msghash, node_2_privkey),
+                       node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
                        bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_btckey),
                        bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_btckey),
                        contents: unsigned_announcement.clone(),
@@ -1171,7 +1357,7 @@ mod tests {
                let secp_ctx = Secp256k1::new();
                let logger: Arc<Logger> = Arc::new(test_utils::TestLogger::new());
                let chain_source = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
-               let net_graph_msg_handler = NetGraphMsgHandler::new(Some(chain_source.clone()), Arc::clone(&logger));
+               let net_graph_msg_handler = NetGraphMsgHandler::new(genesis_block(Network::Testnet).header.block_hash(), Some(chain_source.clone()), Arc::clone(&logger));
 
                let node_1_privkey = &SecretKey::from_slice(&[42; 32]).unwrap();
                let node_2_privkey = &SecretKey::from_slice(&[41; 32]).unwrap();
@@ -1254,7 +1440,7 @@ mod tests {
                }
 
                unsigned_channel_update.timestamp += 100;
-               unsigned_channel_update.excess_data.push(1);
+               unsigned_channel_update.excess_data.resize(MAX_EXCESS_BYTES_FOR_RELAY + 1, 0);
                let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_channel_update.encode()[..])[..]);
                let valid_channel_update = ChannelUpdate {
                        signature: secp_ctx.sign(&msghash, node_1_privkey),
@@ -1302,7 +1488,7 @@ mod tests {
 
                match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
                        Ok(_) => panic!(),
-                       Err(e) => assert_eq!(e.err, "htlc_maximum_msat is larger than channel capacity")
+                       Err(e) => assert_eq!(e.err, "htlc_maximum_msat is larger than channel capacity or capacity is bogus")
                };
                unsigned_channel_update.htlc_maximum_msat = OptionalField::Absent;
 
@@ -1554,7 +1740,7 @@ mod tests {
                                htlc_maximum_msat: OptionalField::Absent,
                                fee_base_msat: 10000,
                                fee_proportional_millionths: 20,
-                               excess_data: [1; 3].to_vec()
+                               excess_data: [1; MAX_EXCESS_BYTES_FOR_RELAY + 1].to_vec()
                        };
                        let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_channel_update.encode()[..])[..]);
                        let valid_channel_update = ChannelUpdate {
@@ -1683,7 +1869,7 @@ mod tests {
                                alias: [0; 32],
                                addresses: Vec::new(),
                                excess_address_data: Vec::new(),
-                               excess_data: [1; 3].to_vec(),
+                               excess_data: [1; MAX_EXCESS_BYTES_FOR_RELAY + 1].to_vec(),
                        };
                        let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
                        let valid_announcement = NodeAnnouncement {
@@ -1766,4 +1952,168 @@ mod tests {
                network.write(&mut w).unwrap();
                assert!(<NetworkGraph>::read(&mut ::std::io::Cursor::new(&w.0)).unwrap() == *network);
        }
+
+       #[test]
+       fn calling_sync_routing_table() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey_1 = &SecretKey::from_slice(&[42; 32]).unwrap();
+               let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_privkey_1);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+               let first_blocknum = 0;
+               let number_of_blocks = 0xffff_ffff;
+
+               // It should ignore if gossip_queries feature is not enabled
+               {
+                       let init_msg = Init { features: InitFeatures::known().clear_gossip_queries() };
+                       net_graph_msg_handler.sync_routing_table(&node_id_1, &init_msg);
+                       let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
+                       assert_eq!(events.len(), 0);
+               }
+
+               // It should send a query_channel_message with the correct information
+               {
+                       let init_msg = Init { features: InitFeatures::known() };
+                       net_graph_msg_handler.sync_routing_table(&node_id_1, &init_msg);
+                       let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
+                       assert_eq!(events.len(), 1);
+                       match &events[0] {
+                               MessageSendEvent::SendChannelRangeQuery{ node_id, msg } => {
+                                       assert_eq!(node_id, &node_id_1);
+                                       assert_eq!(msg.chain_hash, chain_hash);
+                                       assert_eq!(msg.first_blocknum, first_blocknum);
+                                       assert_eq!(msg.number_of_blocks, number_of_blocks);
+                               },
+                               _ => panic!("Expected MessageSendEvent::SendChannelRangeQuery")
+                       };
+               }
+
+               // It should not enqueue a query when should_request_full_sync return false.
+               // The initial implementation allows syncing with the first 5 peers after
+               // which should_request_full_sync will return false
+               {
+                       let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+                       let init_msg = Init { features: InitFeatures::known() };
+                       for n in 1..7 {
+                               let node_privkey = &SecretKey::from_slice(&[n; 32]).unwrap();
+                               let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
+                               net_graph_msg_handler.sync_routing_table(&node_id, &init_msg);
+                               let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
+                               if n <= 5 {
+                                       assert_eq!(events.len(), 1);
+                               } else {
+                                       assert_eq!(events.len(), 0);
+                               }
+
+                       }
+               }
+       }
+
+       #[test]
+       fn handling_reply_channel_range() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey_1 = &SecretKey::from_slice(&[42; 32]).unwrap();
+               let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_privkey_1);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+
+               // Test receipt of a single reply that should enqueue an SCID query
+               // matching the SCIDs in the reply
+               {
+                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, ReplyChannelRange {
+                               chain_hash,
+                               sync_complete: true,
+                               first_blocknum: 0,
+                               number_of_blocks: 2000,
+                               short_channel_ids: vec![
+                                       0x0003e0_000000_0000, // 992x0x0
+                                       0x0003e8_000000_0000, // 1000x0x0
+                                       0x0003e9_000000_0000, // 1001x0x0
+                                       0x0003f0_000000_0000, // 1008x0x0
+                                       0x00044c_000000_0000, // 1100x0x0
+                                       0x0006e0_000000_0000, // 1760x0x0
+                               ],
+                       });
+                       assert!(result.is_ok());
+
+                       // We expect to emit a query_short_channel_ids message with the received scids
+                       let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
+                       assert_eq!(events.len(), 1);
+                       match &events[0] {
+                               MessageSendEvent::SendShortIdsQuery { node_id, msg } => {
+                                       assert_eq!(node_id, &node_id_1);
+                                       assert_eq!(msg.chain_hash, chain_hash);
+                                       assert_eq!(msg.short_channel_ids, vec![
+                                               0x0003e0_000000_0000, // 992x0x0
+                                               0x0003e8_000000_0000, // 1000x0x0
+                                               0x0003e9_000000_0000, // 1001x0x0
+                                               0x0003f0_000000_0000, // 1008x0x0
+                                               0x00044c_000000_0000, // 1100x0x0
+                                               0x0006e0_000000_0000, // 1760x0x0
+                                       ]);
+                               },
+                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
+                       }
+               }
+       }
+
+       #[test]
+       fn handling_reply_short_channel_ids() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey = &SecretKey::from_slice(&[41; 32]).unwrap();
+               let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+
+               // Test receipt of a successful reply
+               {
+                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, ReplyShortChannelIdsEnd {
+                               chain_hash,
+                               full_information: true,
+                       });
+                       assert!(result.is_ok());
+               }
+
+               // Test receipt of a reply that indicates the peer does not maintain up-to-date information
+               // for the chain_hash requested in the query.
+               {
+                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, ReplyShortChannelIdsEnd {
+                               chain_hash,
+                               full_information: false,
+                       });
+                       assert!(result.is_err());
+                       assert_eq!(result.err().unwrap().err, "Received reply_short_channel_ids_end with no information");
+               }
+       }
+
+       #[test]
+       fn handling_query_channel_range() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey = &SecretKey::from_slice(&[41; 32]).unwrap();
+               let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+
+               let result = net_graph_msg_handler.handle_query_channel_range(&node_id, QueryChannelRange {
+                       chain_hash,
+                       first_blocknum: 0,
+                       number_of_blocks: 0xffff_ffff,
+               });
+               assert!(result.is_err());
+       }
+
+       #[test]
+       fn handling_query_short_channel_ids() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey = &SecretKey::from_slice(&[41; 32]).unwrap();
+               let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+
+               let result = net_graph_msg_handler.handle_query_short_channel_ids(&node_id, QueryShortChannelIds {
+                       chain_hash,
+                       short_channel_ids: vec![0x0003e8_000000_0000],
+               });
+               assert!(result.is_err());
+       }
 }