Actual no_std support
[rust-lightning] / lightning / src / routing / network_graph.rs
index bce9633012c6a21a2a35e16663add90a1b4c36a3..486b71578f3fde8775e1d7fe86bd0283c5ef7d8e 100644 (file)
@@ -23,37 +23,35 @@ 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;
-
-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::collections::HashMap;
-use std::ops::Deref;
+use util::logger::{Logger, Level};
+use util::events::{MessageSendEvent, MessageSendEventsProvider};
+use util::scid_utils::{block_from_scid, scid_from_parts, MAX_SCID_BLOCK};
+
+use io;
+use prelude::*;
+use alloc::collections::{BTreeMap, btree_map::Entry as BtreeEntry};
+use core::{cmp, fmt};
+use sync::{RwLock, RwLockReadGuard};
+use core::sync::atomic::{AtomicUsize, Ordering};
+use sync::Mutex;
+use core::ops::Deref;
 use bitcoin::hashes::hex::ToHex;
 
-/// Maximum number of short_channel_id values that can be encoded in a
-/// single reply_channel_range or query_short_channel_ids messages when
-/// using raw encoding. The maximum value ensures that the 8-byte SCIDs
-/// fit inside the maximum size of the Lightning message, 65535-bytes.
-const MAX_SHORT_CHANNEL_ID_BATCH_SIZE: usize = 8000;
+/// 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;
 
-/// Maximum number of reply_channel_range messages we will allow in
-/// reply to a query_channel_range. This value creates an upper-limit 
-/// on the number of SCIDs we process in reply to a single query.
-const MAX_REPLY_CHANNEL_RANGE_PER_QUERY: usize = 250;
+/// Maximum number of short_channel_ids that will be encoded in one gossip reply message.
+/// This value ensures a reply fits within the 65k payload limit and is consistent with other implementations.
+const MAX_SCIDS_PER_REPLY: usize = 8000;
 
 /// Represents the network as nodes and channels between them
-#[derive(PartialEq)]
+#[derive(Clone, PartialEq)]
 pub struct NetworkGraph {
        genesis_hash: BlockHash,
        channels: BTreeMap<u64, ChannelInfo>,
@@ -76,9 +74,7 @@ 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<events::MessageSendEvent>>,
-       chan_range_query_tasks: Mutex<HashMap<PublicKey, ChanRangeQueryTask>>,
-       scid_query_tasks: Mutex<HashMap<PublicKey, ScidQueryTask>>,
+       pending_events: Mutex<Vec<MessageSendEvent>>,
        logger: L,
 }
 
@@ -95,8 +91,6 @@ impl<C: Deref, L: Deref> NetGraphMsgHandler<C, L> where C::Target: chain::Access
                        full_syncs_requested: AtomicUsize::new(0),
                        chain_access,
                        pending_events: Mutex::new(vec![]),
-                       chan_range_query_tasks: Mutex::new(HashMap::new()),
-                       scid_query_tasks: Mutex::new(HashMap::new()),
                        logger,
                }
        }
@@ -110,12 +104,17 @@ impl<C: Deref, L: Deref> NetGraphMsgHandler<C, L> where C::Target: chain::Access
                        full_syncs_requested: AtomicUsize::new(0),
                        chain_access,
                        pending_events: Mutex::new(vec![]),
-                       chan_range_query_tasks: Mutex::new(HashMap::new()),
-                       scid_query_tasks: Mutex::new(HashMap::new()),
                        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
@@ -124,26 +123,16 @@ impl<C: Deref, L: Deref> NetGraphMsgHandler<C, L> where C::Target: chain::Access
                LockedNetworkGraph(self.network_graph.read().unwrap())
        }
 
-       /// Enqueues a message send event for a batch of short_channel_ids
-       /// in a task.
-       fn finalize_query_short_ids(&self, task: &mut ScidQueryTask) {
-               let scid_size = std::cmp::min(task.short_channel_ids.len(), MAX_SHORT_CHANNEL_ID_BATCH_SIZE);
-               let mut short_channel_ids: Vec<u64> = Vec::with_capacity(scid_size);
-               for scid in task.short_channel_ids.drain(..scid_size) {
-                       short_channel_ids.push(scid);
+       /// 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
                }
-
-               log_debug!(self.logger, "Sending query_short_channel_ids peer={}, batch_size={}", log_pubkey!(task.node_id), scid_size);
-
-               // enqueue the message to the peer
-               let mut pending_events = self.pending_events.lock().unwrap();
-               pending_events.push(events::MessageSendEvent::SendShortIdsQuery {
-                       node_id: task.node_id.clone(),
-                       msg: QueryShortChannelIds {
-                               chain_hash: task.chain_hash.clone(),
-                               short_channel_ids,
-                       }
-               });
        }
 }
 
@@ -164,27 +153,33 @@ 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 {
+impl<C: Deref , L: Deref > 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, &self.secp_ctx)?;
-               Ok(msg.contents.excess_data.is_empty() && msg.contents.excess_address_data.is_empty())
+               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> {
                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 { "" });
-               Ok(msg.contents.excess_data.is_empty())
+               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 chan_enabled = msg.contents.flags & (1 << 1) != (1 << 1);
+                               log_debug!(self.logger, "Updating channel with channel_update from a payment failure. Channel {} is {}abled.", msg.contents.short_channel_id, if chan_enabled { "en" } else { "dis" });
                                let _ = self.network_graph.write().unwrap().update_channel(msg, &self.secp_ctx);
                        },
                        &msgs::HTLCFailChannelUpdate::ChannelClosed { short_channel_id, is_permanent } => {
+                               log_debug!(self.logger, "{} channel graph entry for {} due to a payment failure.", if is_permanent { "Removing" } else { "Disabling" }, short_channel_id);
                                self.network_graph.write().unwrap().close_channel_from_update(short_channel_id, is_permanent);
                        },
                        &msgs::HTLCFailChannelUpdate::NodeFailure { ref node_id, is_permanent } => {
+                               log_debug!(self.logger, "{} node graph entry for {} due to a payment failure.", if is_permanent { "Removing" } else { "Disabling" }, node_id);
                                self.network_graph.write().unwrap().fail_node(node_id, is_permanent);
                        },
                }
@@ -192,7 +187,7 @@ 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, &self.secp_ctx)?;
-               Ok(msg.contents.excess_data.is_empty())
+               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>)> {
@@ -247,293 +242,192 @@ 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) {
 
-       fn query_channel_range(&self, their_node_id: &PublicKey, chain_hash: BlockHash, first_blocknum: u32, number_of_blocks: u32) -> Result<(), LightningError> {
-               // We must ensure that we only have a single in-flight query
-               // to the remote peer. If we already have a query, then we fail
-               let mut query_range_tasks_lock = self.chan_range_query_tasks.lock().unwrap();
-               let query_range_tasks = &mut *query_range_tasks_lock;
-               if query_range_tasks.contains_key(their_node_id) {
-                       return Err(LightningError {
-                               err: String::from("query_channel_range already in-flight"),
-                               action: ErrorAction::IgnoreError,
-                       });
+               // We will only perform a sync with peers that support gossip_queries.
+               if !init_msg.features.supports_gossip_queries() {
+                       return ();
                }
 
-               // Construct a new task to keep track of the query until the full
-               // range query has been completed
-               let task = ChanRangeQueryTask::new(their_node_id, chain_hash, first_blocknum, number_of_blocks);
-               query_range_tasks.insert(their_node_id.clone(), task);
+               // Check if we need to perform a full synchronization with this peer
+               if !self.should_request_full_sync(their_node_id) {
+                       return ();
+               }
 
-               // Enqueue the message send event
+               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(events::MessageSendEvent::SendChannelRangeQuery {
+               pending_events.push(MessageSendEvent::SendChannelRangeQuery {
                        node_id: their_node_id.clone(),
                        msg: QueryChannelRange {
-                               chain_hash,
+                               chain_hash: self.network_graph.read().unwrap().genesis_hash,
                                first_blocknum,
                                number_of_blocks,
                        },
                });
-               Ok(())
        }
 
-       /// A query should only request channels referring to unspent outputs.
-       /// This method does not validate this requirement and expects the
-       /// caller to ensure SCIDs are unspent.
-       fn query_short_channel_ids(&self, their_node_id: &PublicKey, chain_hash: BlockHash, short_channel_ids: Vec<u64>) -> Result<(), LightningError> {
-               // Create a new task or add to the existing task
-               let mut query_scids_tasks_lock = self.scid_query_tasks.lock().unwrap();
-               let query_scids_tasks = &mut *query_scids_tasks_lock;
-
-               // For an existing task we append the short_channel_ids which will be sent when the
-               // current in-flight batch completes.
-               if let Some(task) = query_scids_tasks.get_mut(their_node_id) {
-                       task.add(short_channel_ids);
-                       return Ok(());
-               }
+       /// 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(),);
 
-               // For a new task we create the task with short_channel_ids and send the first
-               // batch immediately.
-               query_scids_tasks.insert(their_node_id.clone(), ScidQueryTask::new(
-                       their_node_id,
-                       chain_hash.clone(),
-                       short_channel_ids,
-               ));
-               let task = query_scids_tasks.get_mut(their_node_id).unwrap();
-               self.finalize_query_short_ids(task);
-               return Ok(());
-       }
+               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,
+                       }
+               });
 
-       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={}, full_information={}, scids={}", log_pubkey!(their_node_id), msg.first_blocknum, msg.number_of_blocks, msg.full_information, msg.short_channel_ids.len(),);
+               Ok(())
+       }
 
-               // First we obtain a lock on the task hashmap. In order to avoid borrowing issues
-               // we will access the task as needed.
-               let mut query_range_tasks = self.chan_range_query_tasks.lock().unwrap();
+       /// 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 there is no currently executing task then we have received
-               // an invalid message and will return an error
-               if query_range_tasks.get(their_node_id).is_none() {
+               // 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 unknown reply_channel_range message"),
-                               action: ErrorAction::IgnoreError,
+                               err: String::from("Received reply_short_channel_ids_end with no information"),
+                               action: ErrorAction::IgnoreError
                        });
                }
 
-               // Now that we know we have a task, we can extract a few values for use
-               // in validations without having to access the task repeatedly
-               let (task_chain_hash, task_first_blocknum, task_number_of_blocks, task_received_first_block, task_received_last_block, task_number_of_replies) = {
-                       let task = query_range_tasks.get(their_node_id).unwrap();
-                       (task.chain_hash, task.first_blocknum, task.number_of_blocks, task.received_first_block, task.received_last_block, task.number_of_replies)
-               };
+               Ok(())
+       }
 
-               // Validate the chain_hash matches the chain_hash we used in the query.
-               // If it does not, then the message is malformed and we return an error
-               if msg.chain_hash != task_chain_hash {
-                       query_range_tasks.remove(their_node_id);
-                       return Err(LightningError {
-                               err: String::from("Received reply_channel_range with invalid chain_hash"),
-                               action: ErrorAction::IgnoreError,
-                       });
-               }
+       /// Processes a query from a peer by finding announced/public channels whose funding UTXOs
+       /// are in the specified block range. Due to message size limits, large range
+       /// queries may result in several reply messages. This implementation enqueues
+       /// all reply messages into pending events. Each message will allocate just under 65KiB. A full
+       /// sync of the public routing table with 128k channels will generated 16 messages and allocate ~1MB.
+       /// Logic can be changed to reduce allocation if/when a full sync of the routing table impacts
+       /// memory constrained systems.
+       fn handle_query_channel_range(&self, their_node_id: &PublicKey, msg: QueryChannelRange) -> Result<(), LightningError> {
+               log_debug!(self.logger, "Handling query_channel_range peer={}, first_blocknum={}, number_of_blocks={}", log_pubkey!(their_node_id), msg.first_blocknum, msg.number_of_blocks);
+
+               let network_graph = self.network_graph.read().unwrap();
 
-               // Validate that the remote node maintains up-to-date channel
-               // information for chain_hash. Some nodes use the full_information
-               // flag to indicate multi-part messages so we must check whether
-               // we received information as well.
-               if !msg.full_information && msg.short_channel_ids.len() == 0 {
-                       query_range_tasks.remove(their_node_id);
+               let inclusive_start_scid = scid_from_parts(msg.first_blocknum as u64, 0, 0);
+
+               // We might receive valid queries with end_blocknum that would overflow SCID conversion.
+               // If so, we manually cap the ending block to avoid this overflow.
+               let exclusive_end_scid = scid_from_parts(cmp::min(msg.end_blocknum() as u64, MAX_SCID_BLOCK), 0, 0);
+
+               // Per spec, we must reply to a query. Send an empty message when things are invalid.
+               if msg.chain_hash != network_graph.genesis_hash || inclusive_start_scid.is_err() || exclusive_end_scid.is_err() || msg.number_of_blocks == 0 {
+                       let mut pending_events = self.pending_events.lock().unwrap();
+                       pending_events.push(MessageSendEvent::SendReplyChannelRange {
+                               node_id: their_node_id.clone(),
+                               msg: ReplyChannelRange {
+                                       chain_hash: msg.chain_hash.clone(),
+                                       first_blocknum: msg.first_blocknum,
+                                       number_of_blocks: msg.number_of_blocks,
+                                       sync_complete: true,
+                                       short_channel_ids: vec![],
+                               }
+                       });
                        return Err(LightningError {
-                               err: String::from("Received reply_channel_range with no information available"),
+                               err: String::from("query_channel_range could not be processed"),
                                action: ErrorAction::IgnoreError,
                        });
                }
 
-               // Calculate the last block for the message and the task
-               let msg_last_block = last_blocknum(msg.first_blocknum, msg.number_of_blocks);
-               let task_last_block = last_blocknum(task_first_blocknum, task_number_of_blocks);
-
-               // On the first message...
-               if task_received_first_block.is_none() {
-                       // The replies can be a superset of the queried block range, but the
-                       // replies must include our requested query range. We check if the
-                       // start of the replies is greater than the start of our query. If
-                       // so, the start of our query is excluded and the message is malformed.
-                       if msg.first_blocknum > task_first_blocknum {
-                               query_range_tasks.remove(their_node_id);
-                               return Err(LightningError {
-                                       err: String::from("Failing reply_channel_range with invalid first_blocknum"),
-                                       action: ErrorAction::IgnoreError,
-                               });
-                       }
-
-                       // Next, we ensure the reply has at least some information matching
-                       // our query. If the received last_blocknum is less than our query's
-                       // first_blocknum then the reply does not encompass the query range
-                       // and the message is malformed.
-                       if msg_last_block < task_first_blocknum {
-                               query_range_tasks.remove(their_node_id);
-                               return Err(LightningError {
-                                       err: String::from("Failing reply_channel_range with non-overlapping first reply"),
-                                       action: ErrorAction::IgnoreError,
-                               });
-                       }
-
-                       // Capture the first block and last block so that subsequent messages
-                       // can be validated.
-                       let task = query_range_tasks.get_mut(their_node_id).unwrap();
-                       task.received_first_block = Some(msg.first_blocknum);
-                       task.received_last_block = Some(msg_last_block);
-               }
-               // On subsequent message(s)...
-               else {
-                       // We need to validate the sequence of the reply message is expected.
-                       // Subsequent messages must set the first_blocknum to the previous
-                       // message's first_blocknum plus number_of_blocks. There is discrepancy
-                       // in implementation where some resume on the last sent block. We will
-                       // loosen the restriction and accept either, and otherwise consider the
-                       // message malformed and return an error.
-                       let task_received_last_block = task_received_last_block.unwrap();
-                       if msg.first_blocknum != task_received_last_block && msg.first_blocknum != task_received_last_block + 1 {
-                               query_range_tasks.remove(their_node_id);
-                               return Err(LightningError {
-                                       err: String::from("Failing reply_channel_range with invalid sequence"),
-                                       action: ErrorAction::IgnoreError,
-                               });
-                       }
+               // Creates channel batches. We are not checking if the channel is routable
+               // (has at least one update). A peer may still want to know the channel
+               // exists even if its not yet routable.
+               let mut batches: Vec<Vec<u64>> = vec![Vec::with_capacity(MAX_SCIDS_PER_REPLY)];
+               for (_, ref chan) in network_graph.get_channels().range(inclusive_start_scid.unwrap()..exclusive_end_scid.unwrap()) {
+                       if let Some(chan_announcement) = &chan.announcement_message {
+                               // Construct a new batch if last one is full
+                               if batches.last().unwrap().len() == batches.last().unwrap().capacity() {
+                                       batches.push(Vec::with_capacity(MAX_SCIDS_PER_REPLY));
+                               }
 
-                       // Next we check to see that we have received a realistic number of
-                       // reply messages for a query. This caps the allocation exposure
-                       // for short_channel_ids that will be batched and sent in query channels.
-                       if task_number_of_replies + 1 > MAX_REPLY_CHANNEL_RANGE_PER_QUERY {
-                               query_range_tasks.remove(their_node_id);
-                               return Err(LightningError {
-                                       err: String::from("Failing reply_channel_range due to excessive messages"),
-                                       action: ErrorAction::IgnoreError,
-                               });
+                               let batch = batches.last_mut().unwrap();
+                               batch.push(chan_announcement.contents.short_channel_id);
                        }
-
-                       // Capture the last_block in our task so that subsequent messages
-                       // can be validated.
-                       let task = query_range_tasks.get_mut(their_node_id).unwrap();
-                       task.number_of_replies += 1;
-                       task.received_last_block = Some(msg_last_block);
-               }
-
-               // We filter the short_channel_ids to those inside the query range.
-               // The most significant 3-bytes of the short_channel_id are the block.
-               {
-                       let mut filtered_short_channel_ids: Vec<u64> = msg.short_channel_ids.clone().into_iter().filter(|short_channel_id| {
-                               let block = short_channel_id >> 40;
-                               return block >= query_range_tasks.get(their_node_id).unwrap().first_blocknum as u64 && block <= task_last_block as u64;
-                       }).collect();
-                       let task = query_range_tasks.get_mut(their_node_id).unwrap();
-                       task.short_channel_ids.append(&mut filtered_short_channel_ids);
                }
+               drop(network_graph);
 
-               // The final message is indicated by a last_blocknum that is equal to
-               // or greater than the query's last_blocknum.
-               if msg_last_block >= task_last_block {
-                       log_debug!(self.logger, "Completed query_channel_range: peer={}, first_blocknum={}, number_of_blocks={}", log_pubkey!(their_node_id), task_first_blocknum, task_number_of_blocks);
-
-                       // We can now fire off a query to obtain routing messages for the
-                       // accumulated short_channel_ids.
-                       {
-                               let task = query_range_tasks.get_mut(their_node_id).unwrap();
-                               let mut short_channel_ids = Vec::new();
-                               std::mem::swap(&mut short_channel_ids, &mut task.short_channel_ids);
-                               self.query_short_channel_ids(their_node_id, task.chain_hash, short_channel_ids)?;
+               let mut pending_events = self.pending_events.lock().unwrap();
+               let batch_count = batches.len();
+               let mut prev_batch_endblock = msg.first_blocknum;
+               for (batch_index, batch) in batches.into_iter().enumerate() {
+                       // Per spec, the initial `first_blocknum` needs to be <= the query's `first_blocknum`
+                       // and subsequent `first_blocknum`s must be >= the prior reply's `first_blocknum`.
+                       //
+                       // Additionally, c-lightning versions < 0.10 require that the `first_blocknum` of each
+                       // reply is >= the previous reply's `first_blocknum` and either exactly the previous
+                       // reply's `first_blocknum + number_of_blocks` or exactly one greater. This is a
+                       // significant diversion from the requirements set by the spec, and, in case of blocks
+                       // with no channel opens (e.g. empty blocks), requires that we use the previous value
+                       // and *not* derive the first_blocknum from the actual first block of the reply.
+                       let first_blocknum = prev_batch_endblock;
+
+                       // Each message carries the number of blocks (from the `first_blocknum`) its contents
+                       // fit in. Though there is no requirement that we use exactly the number of blocks its
+                       // contents are from, except for the bogus requirements c-lightning enforces, above.
+                       //
+                       // Per spec, the last end block (ie `first_blocknum + number_of_blocks`) needs to be
+                       // >= the query's end block. Thus, for the last reply, we calculate the difference
+                       // between the query's end block and the start of the reply.
+                       //
+                       // Overflow safe since end_blocknum=msg.first_block_num+msg.number_of_blocks and
+                       // first_blocknum will be either msg.first_blocknum or a higher block height.
+                       let (sync_complete, number_of_blocks) = if batch_index == batch_count-1 {
+                               (true, msg.end_blocknum() - first_blocknum)
                        }
+                       // Prior replies should use the number of blocks that fit into the reply. Overflow
+                       // safe since first_blocknum is always <= last SCID's block.
+                       else {
+                               (false, block_from_scid(batch.last().unwrap()) - first_blocknum)
+                       };
 
-                       // We can remove the query range task now that the query is complete.
-                       query_range_tasks.remove(their_node_id);
-               }
-               Ok(())
-       }
-
-       /// When a 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);
-
-               // First we obtain a lock on the task hashmap. In order to avoid borrowing issues
-               // we will access the task as needed.
-               let mut query_short_channel_ids_tasks = self.scid_query_tasks.lock().unwrap();
-
-               // If there is no existing task then we have received an unknown
-               // message and should return an error.
-               if query_short_channel_ids_tasks.get(their_node_id).is_none() {
-                       return Err(LightningError {
-                               err: String::from("Unknown reply_short_channel_ids_end message"),
-                               action: ErrorAction::IgnoreError,
-                       });
-               }
-
-               // If the reply's chain_hash does not match the task's chain_hash then
-               // the reply is malformed and we should return an error.
-               if msg.chain_hash != query_short_channel_ids_tasks.get(their_node_id).unwrap().chain_hash {
-                       query_short_channel_ids_tasks.remove(their_node_id);
-                       return Err(LightningError {
-                               err: String::from("Received reply_short_channel_ids_end with incorrect chain_hash"),
-                               action: ErrorAction::IgnoreError
-                       });
-               }
+                       prev_batch_endblock = first_blocknum + number_of_blocks;
 
-               // 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 {
-                       query_short_channel_ids_tasks.remove(their_node_id);
-                       return Err(LightningError {
-                               err: String::from("Received reply_short_channel_ids_end with no information"),
-                               action: ErrorAction::IgnoreError
+                       pending_events.push(MessageSendEvent::SendReplyChannelRange {
+                               node_id: their_node_id.clone(),
+                               msg: ReplyChannelRange {
+                                       chain_hash: msg.chain_hash.clone(),
+                                       first_blocknum,
+                                       number_of_blocks,
+                                       sync_complete,
+                                       short_channel_ids: batch,
+                               }
                        });
                }
 
-               // If we have more scids to process we send the next batch in the task
-               {
-                       let task = query_short_channel_ids_tasks.get_mut(their_node_id).unwrap();
-                       if task.short_channel_ids.len() > 0 {
-                               self.finalize_query_short_ids(task);
-                               return Ok(());
-                       }
-               }
-
-               // Otherwise the task is complete and we can remove it
-               log_debug!(self.logger, "Completed query_short_channel_ids peer={}", log_pubkey!(their_node_id));
-               query_short_channel_ids_tasks.remove(their_node_id);
                Ok(())
        }
 
-       /// There are potential DoS vectors when handling inbound queries.
-       /// Handling requests with first_blocknum very far away may trigger repeated
-       /// disk I/O if the NetworkGraph is not fully in-memory.
-       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,
-               })
-       }
-
-       /// There are potential DoS vectors when handling inbound queries.
-       /// Handling requests with first_blocknum very far away may trigger repeated
-       /// disk I/O if the NetworkGraph is not fully in-memory.
-       fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: &QueryShortChannelIds) -> Result<(), LightningError> {
+       fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: QueryShortChannelIds) -> Result<(), LightningError> {
                // TODO
                Err(LightningError {
                        err: String::from("Not implemented"),
@@ -542,132 +436,20 @@ impl<C: Deref + Sync + Send, L: Deref + Sync + Send> RoutingMessageHandler for N
        }
 }
 
-impl<C: Deref, L: Deref> events::MessageSendEventsProvider for NetGraphMsgHandler<C, L>
+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<events::MessageSendEvent> {
+       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);
+               core::mem::swap(&mut ret, &mut pending_events);
                ret
        }
 }
 
-/// Safely calculates the last_blocknum given a first_blocknum and
-/// number_of_blocks by returning the u32::MAX-1 if there is an overflow
-fn last_blocknum(first_blocknum: u32, number_of_blocks: u32) -> u32 {
-       match first_blocknum.checked_add(number_of_blocks) {
-               Some(val) => val - 1,
-               None => 0xffff_ffff - 1,
-       }
-}
-
-/// Maintains state for a channel range query that we initiated.
-/// The query may result in one or more reply_channel_range messages
-/// being received. This struct helps determine the status of the query
-/// when there are multiple replies. It also collects results for initiating
-/// SCID queries.
-///
-/// The task is complete and can be cleaned up when a reply meets or
-/// exceeds the last block in the query. The collected SCIDs in the task
-/// can be used to generate an ScidQueryTask.
-///
-/// A query may fail if the recipient does not maintain up-to-date
-/// information for the chain or if the recipient fails to reply within
-/// a reasonable amount of time. In either event, the query can be
-/// re-initiated with a different peer.
-pub struct ChanRangeQueryTask {
-       /// The public key of the node we will be sending queries to
-       pub node_id: PublicKey,
-       /// The genesis hash of the blockchain being queried
-       pub chain_hash: BlockHash,
-       /// The height of the first block for the channel UTXOs being queried
-       pub first_blocknum: u32,
-       /// The number of blocks to include in the query results
-       pub number_of_blocks: u32,
-       /// Tracks the number of reply messages we have received
-       pub number_of_replies: usize,
-       /// The height of the first block received in a reply. This value
-       /// should be less than or equal to the first_blocknum requested in
-       /// the query_channel_range. This allows the range of the replies to
-       /// contain, but not necessarily strictly, the queried range.
-       pub received_first_block: Option<u32>,
-       /// The height of the last block received in a reply. This value
-       /// will get incrementally closer to the target of
-       /// first_blocknum plus number_of_blocks from the query_channel_range.
-       pub received_last_block: Option<u32>,
-       /// Contains short_channel_ids received in one or more reply messages.
-       /// These will be sent in one ore more query_short_channel_ids messages
-       /// when the task is complete.
-       pub short_channel_ids: Vec<u64>,
-}
-
-impl ChanRangeQueryTask {
-       /// Constructs a new GossipQueryRangeTask
-       pub fn new(their_node_id: &PublicKey, chain_hash: BlockHash, first_blocknum: u32, number_of_blocks: u32) -> Self {
-               ChanRangeQueryTask {
-                       node_id: their_node_id.clone(),
-                       chain_hash,
-                       first_blocknum,
-                       number_of_blocks,
-                       number_of_replies: 0,
-                       received_first_block: None,
-                       received_last_block: None,
-                       short_channel_ids: vec![],
-               }
-       }
-}
-
-/// Maintains state when sending one or more short_channel_ids messages
-/// to a peer. Only a single SCID query can be in-flight with a peer. The
-/// number of SCIDs per query is limited by the size of a Lightning message
-/// payload. When querying a large number of SCIDs (results of a large
-/// channel range query for instance), multiple query_short_channel_ids
-/// messages need to be sent. This task maintains the list of awaiting
-/// SCIDs to be queried.
-///
-/// When a successful reply_short_channel_ids_end message is received, the
-/// next batch of SCIDs can be sent. When no remaining SCIDs exist in the
-/// task, the task is complete and can be cleaned up.
-///
-/// The recipient may reply indicating that up-to-date information for the
-/// chain is not maintained. A query may also fail to complete within a
-/// reasonable amount of time. In either event, the short_channel_ids
-/// can be queried from a different peer after validating the set of
-/// SCIDs that still need to be queried.
-pub struct ScidQueryTask {
-       /// The public key of the node we will be sending queries to
-       pub node_id: PublicKey,
-       /// The genesis hash of the blockchain being queried
-       pub chain_hash: BlockHash,
-       /// A vector of short_channel_ids that we would like routing gossip
-       /// information for. This list will be chunked and sent to the peer
-       /// in one or more query_short_channel_ids messages.
-       pub short_channel_ids: Vec<u64>,
-}
-
-impl ScidQueryTask {
-       /// Constructs a new GossipQueryShortChannelIdsTask
-       pub fn new(their_node_id: &PublicKey, chain_hash: BlockHash, short_channel_ids: Vec<u64>) -> Self {
-               ScidQueryTask {
-                       node_id: their_node_id.clone(),
-                       chain_hash,
-                       short_channel_ids,
-               }
-       }
-
-       /// Adds short_channel_ids to the pending list of short_channel_ids
-       /// to be sent in the next request. You can add additional values
-       /// while a query is in-flight. These new values will be sent once
-       /// the active query has completed.
-       pub fn add(&mut self, mut short_channel_ids: Vec<u64>) {
-               self.short_channel_ids.append(&mut short_channel_ids);
-       }
-}
-
-#[derive(PartialEq, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 /// Details about one direction of a channel. Received
 /// within a channel update.
 pub struct DirectionalChannelInfo {
@@ -698,17 +480,17 @@ impl fmt::Display for DirectionalChannelInfo {
        }
 }
 
-impl_writeable!(DirectionalChannelInfo, 0, {
-       last_update,
-       enabled,
-       cltv_expiry_delta,
-       htlc_minimum_msat,
-       htlc_maximum_msat,
-       fees,
-       last_update_message
+impl_writeable_tlv_based!(DirectionalChannelInfo, {
+       (0, last_update, required),
+       (2, enabled, required),
+       (4, cltv_expiry_delta, required),
+       (6, htlc_minimum_msat, required),
+       (8, htlc_maximum_msat, required),
+       (10, fees, required),
+       (12, last_update_message, required),
 });
 
-#[derive(PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 /// Details about a channel (both directions).
 /// Received within a channel announcement.
 pub struct ChannelInfo {
@@ -739,14 +521,14 @@ impl fmt::Display for ChannelInfo {
        }
 }
 
-impl_writeable!(ChannelInfo, 0, {
-       features,
-       node_one,
-       one_to_two,
-       node_two,
-       two_to_one,
-       capacity_sats,
-       announcement_message
+impl_writeable_tlv_based!(ChannelInfo, {
+       (0, features, required),
+       (2, node_one, required),
+       (4, one_to_two, required),
+       (6, node_two, required),
+       (8, two_to_one, required),
+       (10, capacity_sats, required),
+       (12, announcement_message, required),
 });
 
 
@@ -760,26 +542,12 @@ pub struct RoutingFees {
        pub proportional_millionths: u32,
 }
 
-impl Readable for RoutingFees{
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<RoutingFees, DecodeError> {
-               let base_msat: u32 = Readable::read(reader)?;
-               let proportional_millionths: u32 = Readable::read(reader)?;
-               Ok(RoutingFees {
-                       base_msat,
-                       proportional_millionths,
-               })
-       }
-}
-
-impl Writeable for RoutingFees {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               self.base_msat.write(writer)?;
-               self.proportional_millionths.write(writer)?;
-               Ok(())
-       }
-}
+impl_writeable_tlv_based!(RoutingFees, {
+       (0, base_msat, required),
+       (2, proportional_millionths, required)
+});
 
-#[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
@@ -802,50 +570,16 @@ pub struct NodeAnnouncementInfo {
        pub announcement_message: Option<NodeAnnouncement>
 }
 
-impl Writeable for NodeAnnouncementInfo {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               self.features.write(writer)?;
-               self.last_update.write(writer)?;
-               self.rgb.write(writer)?;
-               self.alias.write(writer)?;
-               (self.addresses.len() as u64).write(writer)?;
-               for ref addr in &self.addresses {
-                       addr.write(writer)?;
-               }
-               self.announcement_message.write(writer)?;
-               Ok(())
-       }
-}
-
-impl Readable for NodeAnnouncementInfo {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<NodeAnnouncementInfo, DecodeError> {
-               let features = Readable::read(reader)?;
-               let last_update = Readable::read(reader)?;
-               let rgb = Readable::read(reader)?;
-               let alias = Readable::read(reader)?;
-               let addresses_count: u64 = Readable::read(reader)?;
-               let mut addresses = Vec::with_capacity(cmp::min(addresses_count, MAX_ALLOC_SIZE / 40) as usize);
-               for _ in 0..addresses_count {
-                       match Readable::read(reader) {
-                               Ok(Ok(addr)) => { addresses.push(addr); },
-                               Ok(Err(_)) => return Err(DecodeError::InvalidValue),
-                               Err(DecodeError::ShortRead) => return Err(DecodeError::BadLengthDescriptor),
-                               _ => unreachable!(),
-                       }
-               }
-               let announcement_message = Readable::read(reader)?;
-               Ok(NodeAnnouncementInfo {
-                       features,
-                       last_update,
-                       rgb,
-                       alias,
-                       addresses,
-                       announcement_message
-               })
-       }
-}
+impl_writeable_tlv_based!(NodeAnnouncementInfo, {
+       (0, features, required),
+       (2, last_update, required),
+       (4, rgb, required),
+       (6, alias, required),
+       (8, announcement_message, option),
+       (10, addresses, vec_type),
+});
 
-#[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
@@ -868,39 +602,19 @@ impl fmt::Display for NodeInfo {
        }
 }
 
-impl Writeable for NodeInfo {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               (self.channels.len() as u64).write(writer)?;
-               for ref chan in self.channels.iter() {
-                       chan.write(writer)?;
-               }
-               self.lowest_inbound_channel_fees.write(writer)?;
-               self.announcement_info.write(writer)?;
-               Ok(())
-       }
-}
-
-const MAX_ALLOC_SIZE: u64 = 64*1024;
+impl_writeable_tlv_based!(NodeInfo, {
+       (0, lowest_inbound_channel_fees, option),
+       (2, announcement_info, option),
+       (4, channels, vec_type),
+});
 
-impl Readable for NodeInfo {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<NodeInfo, DecodeError> {
-               let channels_count: u64 = Readable::read(reader)?;
-               let mut channels = Vec::with_capacity(cmp::min(channels_count, MAX_ALLOC_SIZE / 8) as usize);
-               for _ in 0..channels_count {
-                       channels.push(Readable::read(reader)?);
-               }
-               let lowest_inbound_channel_fees = Readable::read(reader)?;
-               let announcement_info = Readable::read(reader)?;
-               Ok(NodeInfo {
-                       channels,
-                       lowest_inbound_channel_fees,
-                       announcement_info,
-               })
-       }
-}
+const SERIALIZATION_VERSION: u8 = 1;
+const MIN_SERIALIZATION_VERSION: u8 = 1;
 
 impl Writeable for NetworkGraph {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+               write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
+
                self.genesis_hash.write(writer)?;
                (self.channels.len() as u64).write(writer)?;
                for (ref chan_id, ref chan_info) in self.channels.iter() {
@@ -912,12 +626,16 @@ impl Writeable for NetworkGraph {
                        node_id.write(writer)?;
                        node_info.write(writer)?;
                }
+
+               write_tlv_fields!(writer, {});
                Ok(())
        }
 }
 
 impl Readable for NetworkGraph {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<NetworkGraph, DecodeError> {
+       fn read<R: io::Read>(reader: &mut R) -> Result<NetworkGraph, DecodeError> {
+               let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
+
                let genesis_hash: BlockHash = Readable::read(reader)?;
                let channels_count: u64 = Readable::read(reader)?;
                let mut channels = BTreeMap::new();
@@ -933,6 +651,8 @@ impl Readable for NetworkGraph {
                        let node_info = Readable::read(reader)?;
                        nodes.insert(node_id, node_info);
                }
+               read_tlv_fields!(reader, {});
+
                Ok(NetworkGraph {
                        genesis_hash,
                        channels,
@@ -1014,11 +734,14 @@ impl NetworkGraph {
                        Some(node) => {
                                if let Some(node_info) = node.announcement_info.as_ref() {
                                        if node_info.last_update  >= msg.timestamp {
-                                               return Err(LightningError{err: "Update older than last processed update".to_owned(), action: ErrorAction::IgnoreError});
+                                               return Err(LightningError{err: "Update older than last processed update".to_owned(), action: ErrorAction::IgnoreAndLog(Level::Trace)});
                                        }
                                }
 
-                               let should_relay = msg.excess_data.is_empty() && msg.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.features.clone(),
                                        last_update: msg.timestamp,
@@ -1111,7 +834,8 @@ impl NetworkGraph {
                                node_two: msg.node_id_2.clone(),
                                two_to_one: None,
                                capacity_sats: utxo_value,
-                               announcement_message: if msg.excess_data.is_empty() { full_msg.cloned() } else { None },
+                               announcement_message: if msg.excess_data.len() <= MAX_EXCESS_BYTES_FOR_RELAY
+                                       { full_msg.cloned() } else { None },
                        };
 
                match self.channels.entry(msg.short_channel_id) {
@@ -1131,7 +855,7 @@ impl NetworkGraph {
                                        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})
+                                       return Err(LightningError{err: "Already have knowledge of channel".to_owned(), action: ErrorAction::IgnoreAndLog(Level::Trace)})
                                }
                        },
                        BtreeEntry::Vacant(entry) => {
@@ -1233,14 +957,15 @@ impl NetworkGraph {
                                        ( $target: expr, $src_node: expr) => {
                                                if let Some(existing_chan_info) = $target.as_ref() {
                                                        if existing_chan_info.last_update >= msg.timestamp {
-                                                               return Err(LightningError{err: "Update older than last processed update".to_owned(), action: ErrorAction::IgnoreError});
+                                                               return Err(LightningError{err: "Update older than last processed update".to_owned(), action: ErrorAction::IgnoreAndLog(Level::Trace)});
                                                        }
                                                        chan_was_enabled = existing_chan_info.enabled;
                                                } else {
                                                        chan_was_enabled = false;
                                                }
 
-                                               let last_update_message = if msg.excess_data.is_empty() { full_msg.cloned() } 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,
@@ -1339,15 +1064,16 @@ 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,
                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 util::scid_utils::scid_from_parts;
 
        use bitcoin::hashes::sha256d::Hash as Sha256dHash;
        use bitcoin::hashes::Hash;
@@ -1362,7 +1088,9 @@ mod tests {
        use bitcoin::secp256k1::key::{PublicKey, SecretKey};
        use bitcoin::secp256k1::{All, Secp256k1};
 
-       use std::sync::Arc;
+       use io;
+       use prelude::*;
+       use sync::Arc;
 
        fn create_net_graph_msg_handler() -> (Secp256k1<All>, NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>) {
                let secp_ctx = Secp256k1::new();
@@ -1462,7 +1190,7 @@ 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),
@@ -1630,7 +1358,7 @@ 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),
@@ -1760,7 +1488,7 @@ 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),
@@ -2060,7 +1788,7 @@ 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 {
@@ -2189,7 +1917,7 @@ 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 {
@@ -2270,30 +1998,31 @@ mod tests {
                assert!(!network.get_nodes().is_empty());
                assert!(!network.get_channels().is_empty());
                network.write(&mut w).unwrap();
-               assert!(<NetworkGraph>::read(&mut ::std::io::Cursor::new(&w.0)).unwrap() == *network);
+               assert!(<NetworkGraph>::read(&mut io::Cursor::new(&w.0)).unwrap() == *network);
        }
 
        #[test]
-       fn sending_query_channel_range() {
+       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_privkey_2 = &SecretKey::from_slice(&[41; 32]).unwrap();
                let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_privkey_1);
-               let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_privkey_2);
 
                let chain_hash = genesis_block(Network::Testnet).header.block_hash();
                let first_blocknum = 0;
                let number_of_blocks = 0xffff_ffff;
 
-               // When no active query exists for the node, it should send a query message and generate a task
+               // It should ignore if gossip_queries feature is not enabled
                {
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, first_blocknum, number_of_blocks);
-                       assert!(result.is_ok());
-
-                       // It should create a task for the query
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().contains_key(&node_id_1));
+                       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_range message with the correct information
+               // 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] {
@@ -2307,707 +2036,454 @@ mod tests {
                        };
                }
 
-               // When an active query exists for the node, when there is a subsequent query request, it
-               // should fail to initiate a new query
+               // 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 result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, first_blocknum, number_of_blocks);
-                       assert_eq!(result.is_err(), true);
-               }
-
-               // When no active query exists for a different node, it should send a query message
-               {
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_2, chain_hash, first_blocknum, number_of_blocks);
-                       assert_eq!(result.is_ok(), true);
-
-                       // It should create a task for the query
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().contains_key(&node_id_2));
+                       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);
+                               }
 
-                       // It should send a query_channel_message with the correct information
-                       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_2);
-                                       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")
-                       };
+                       }
                }
        }
 
        #[test]
-       fn sending_query_short_channel_ids() {
+       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();
 
-               // The first query should send the batch of scids to the peer
+               // Test receipt of a single reply that should enqueue an SCID query
+               // matching the SCIDs in the reply
                {
-                       let short_channel_ids: Vec<u64> = vec![0, 1, 2];
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id_1, chain_hash, short_channel_ids.clone());
+                       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());
 
-                       // Validate that we have enqueued a send message event and that it contains the correct information
+                       // 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 } => {
+                               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, short_channel_ids);
+                                       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")
-                       };
-               }
-
-               // Subsequent queries for scids should enqueue them to be sent in the next batch which will
-               // be sent when a reply_short_channel_ids_end message is handled.
-               {
-                       let short_channel_ids: Vec<u64> = vec![3, 4, 5];
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id_1, chain_hash, short_channel_ids.clone());
-                       assert!(result.is_ok());
-
-                       // Validate that we have not enqueued another send message event yet
-                       let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
-                       assert_eq!(events.len(), 0);
-
-                       // Validate the task has the queued scids
-                       assert_eq!(
-                               net_graph_msg_handler.scid_query_tasks.lock().unwrap().get(&node_id_1).unwrap().short_channel_ids,
-                               short_channel_ids
-                       );
+                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
+                       }
                }
        }
 
        #[test]
-       fn handling_reply_channel_range() {
+       fn handling_reply_short_channel_ids() {
                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 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 an unknown reply message. We expect an error
+               // Test receipt of a successful reply
                {
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
+                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, ReplyShortChannelIdsEnd {
                                chain_hash,
                                full_information: true,
-                               first_blocknum: 1000,
-                               number_of_blocks: 1050,
-                               short_channel_ids: vec![
-                                       0x0003e8_000000_0000, // 1000x0x0
-                                       0x0003e9_000000_0000, // 1001x0x0
-                                       0x0003f0_000000_0000  // 1008x0x0
-                               ],
                        });
-                       assert!(result.is_err());
+                       assert!(result.is_ok());
                }
 
-               // Test receipt of a single reply_channel_range that exactly matches the queried range.
-               // It sends a query_short_channel_ids with the returned scids and removes the pending task
+               // Test receipt of a reply that indicates the peer does not maintain up-to-date information
+               // for the chain_hash requested in the query.
                {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle a single successful reply that matches the queried channel range
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
+                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, ReplyShortChannelIdsEnd {
                                chain_hash,
-                               full_information: true,
-                               first_blocknum: 1000,
-                               number_of_blocks: 100,
-                               short_channel_ids: vec![
-                                       0x0003e8_000000_0000, // 1000x0x0
-                                       0x0003e9_000000_0000, // 1001x0x0
-                                       0x0003f0_000000_0000  // 1008x0x0
-                               ],
+                               full_information: false,
                        });
-                       assert!(result.is_ok());
-
-                       // The query is now complete, so we expect the task to be removed
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
+                       assert!(result.is_err());
+                       assert_eq!(result.err().unwrap().err, "Received reply_short_channel_ids_end with no information");
+               }
+       }
 
-                       // We expect to emit a query_short_channel_ids message with scids in our query range
-                       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![0x0003e8_000000_0000,0x0003e9_000000_0000,0x0003f0_000000_0000]);
-                               },
-                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
-                       }
-
-                       // Clean up scid_task
-                       net_graph_msg_handler.scid_query_tasks.lock().unwrap().clear();
-               }
-
-               // Test receipt of a single reply_channel_range for a query that has a u32 overflow. We expect
-               // it sends a query_short_channel_ids with the returned scids and removes the pending task.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 0xffff_ffff);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle a single successful reply that matches the queried channel range
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1000,
-                               number_of_blocks: 0xffff_ffff,
-                               short_channel_ids: vec![
-                                       0x0003e8_000000_0000, // 1000x0x0
-                                       0x0003e9_000000_0000, // 1001x0x0
-                                       0x0003f0_000000_0000  // 1008x0x0
-                               ],
-                       });
-                       assert!(result.is_ok());
-
-                       // The query is now complete, so we expect the task to be removed
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-
-                       // We expect to emit a query_short_channel_ids message with scids in our query range
-                       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![0x0003e8_000000_0000,0x0003e9_000000_0000,0x0003f0_000000_0000]);
-                               },
-                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
-                       }
-
-                       // Clean up scid_task
-                       net_graph_msg_handler.scid_query_tasks.lock().unwrap().clear();
-               }
-
-               // Test receipt of a single reply that encompasses the queried channel range. This is allowed
-               // since a reply must contain at least part of the query range. Receipt of the reply should
-               // send a query_short_channel_ids message with scids filtered to the query range and remove
-               // the pending task.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle a single successful reply that encompasses the queried channel range
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: 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());
-
-                       // The query is now complete, so we expect the task to be removed
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-
-                       // We expect to emit a query_short_channel_ids message with scids filtered to those
-                       // within the original query range.
-                       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![0x0003e8_000000_0000,0x0003e9_000000_0000,0x0003f0_000000_0000]);
-                               },
-                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
-                       }
-
-                       // Clean up scid_task
-                       net_graph_msg_handler.scid_query_tasks.lock().unwrap().clear();
-               }
-
-               // Test receipt of multiple reply messages for a single query. This happens when the number
-               // of scids in the query range exceeds the size limits of a single reply message. We expect
-               // to initiate a query_short_channel_ids for the first batch of scids and we enqueue the
-               // remaining scids for later processing. We remove the range query task after receipt of all
-               // reply messages.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle the first reply message
-                       let reply_1_scids =  vec![
-                               0x0003e8_000000_0000, // 1000x0x0
-                               0x0003e9_000000_0000, // 1001x0x0
-                               0x000419_000000_0000, // 1049x0x0
-                       ];
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1000,
-                               number_of_blocks: 50,
-                               short_channel_ids: reply_1_scids.clone(),
-                       });
-                       assert!(result.is_ok());
-
-                       // Handle the next reply in the sequence, which must start at the previous message's
-                       // first_blocknum plus number_of_blocks. The scids in this reply will be queued.
-                       let reply_2_scids = vec![
-                               0x00041a_000000_0000, // 1050x0x0
-                               0x000432_000000_0000, // 1074x0x0
-                       ];
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1050,
-                               number_of_blocks: 25,
-                               short_channel_ids: reply_2_scids.clone(),
-                       });
-                       assert!(result.is_ok());
-
-                       // Handle the final reply in the sequence, which must meet or exceed the initial query's
-                       // first_blocknum plus number_of_blocks. The scids in this reply will be queued.
-                       let reply_3_scids = vec![
-                               0x000433_000000_0000, // 1075x0x0
-                               0x00044b_000000_0000, // 1099x0x0
-                       ];
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1075,
-                               number_of_blocks: 25,
-                               short_channel_ids: reply_3_scids.clone(),
-                       });
-                       assert!(result.is_ok());
+       #[test]
+       fn handling_query_channel_range() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
 
-                       // After the final reply we expect the query task to be removed
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+               let node_1_privkey = &SecretKey::from_slice(&[42; 32]).unwrap();
+               let node_2_privkey = &SecretKey::from_slice(&[41; 32]).unwrap();
+               let node_1_btckey = &SecretKey::from_slice(&[40; 32]).unwrap();
+               let node_2_btckey = &SecretKey::from_slice(&[39; 32]).unwrap();
+               let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
+               let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
+               let bitcoin_key_1 = PublicKey::from_secret_key(&secp_ctx, node_1_btckey);
+               let bitcoin_key_2 = PublicKey::from_secret_key(&secp_ctx, node_2_btckey);
 
-                       // We expect to emit a query_short_channel_ids message with the accumulated scids that
-                       // match the queried channel range.
-                       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, [reply_1_scids, reply_2_scids, reply_3_scids].concat());
-                               },
-                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
-                       }
+               let mut scids: Vec<u64> = vec![
+                       scid_from_parts(0xfffffe, 0xffffff, 0xffff).unwrap(), // max
+                       scid_from_parts(0xffffff, 0xffffff, 0xffff).unwrap(), // never
+               ];
 
-                       // Clean up scid_task
-                       net_graph_msg_handler.scid_query_tasks.lock().unwrap().clear();
+               // used for testing multipart reply across blocks
+               for block in 100000..=108001 {
+                       scids.push(scid_from_parts(block, 0, 0).unwrap());
                }
 
-               // Test receipt of a sequence of replies with a valid first reply and a second reply that
-               // resumes on the same block as the first reply. The spec requires a subsequent
-               // first_blocknum to equal the prior first_blocknum plus number_of_blocks, however
-               // due to discrepancies in implementation we must loosen this restriction.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
+               // used for testing resumption on same block
+               scids.push(scid_from_parts(108001, 1, 0).unwrap());
 
-                       // Handle the first reply message
-                       let reply_1_scids = vec![
-                               0x0003e8_000000_0000, // 1000x0x0
-                               0x0003e9_000000_0000, // 1001x0x0
-                               0x000419_000000_0000, // 1049x0x0
-                       ];
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1000,
-                               number_of_blocks: 50,
-                               short_channel_ids: reply_1_scids.clone(),
-                       });
-                       assert!(result.is_ok());
-
-                       // Handle the next reply in the sequence, which is non-spec but resumes on the last block
-                       // of the first message.
-                       let reply_2_scids = vec![
-                               0x000419_000001_0000, // 1049x1x0
-                               0x00041a_000000_0000, // 1050x0x0
-                               0x000432_000000_0000, // 1074x0x0
-                       ];
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1049,
-                               number_of_blocks: 51,
-                               short_channel_ids: reply_2_scids.clone(),
-                       });
-                       assert!(result.is_ok());
-
-                       // After the final reply we expect the query task to be removed
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-
-                       // We expect to emit a query_short_channel_ids message with the accumulated scids that
-                       // match the queried channel range
-                       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, [reply_1_scids, reply_2_scids].concat());
-                               },
-                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
-                       }
+               for scid in scids {
+                       let unsigned_announcement = UnsignedChannelAnnouncement {
+                               features: ChannelFeatures::known(),
+                               chain_hash: chain_hash.clone(),
+                               short_channel_id: scid,
+                               node_id_1,
+                               node_id_2,
+                               bitcoin_key_1,
+                               bitcoin_key_2,
+                               excess_data: Vec::new(),
+                       };
 
-                       // Clean up scid_task
-                       net_graph_msg_handler.scid_query_tasks.lock().unwrap().clear();
+                       let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
+                       let valid_announcement = ChannelAnnouncement {
+                               node_signature_1: secp_ctx.sign(&msghash, node_1_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(),
+                       };
+                       match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
+                               Ok(_) => (),
+                               _ => panic!()
+                       };
                }
 
-               // Test receipt of reply with a chain_hash that does not match the query. We expect to return
-               // an error and to remove the query task.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle the reply with a mismatched chain_hash. We expect IgnoreError result and the
-                       // task should be removed.
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
+               // Error when number_of_blocks=0
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 0,
+                               number_of_blocks: 0,
+                       },
+                       false,
+                       vec![ReplyChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 0,
+                               number_of_blocks: 0,
+                               sync_complete: true,
+                               short_channel_ids: vec![]
+                       }]
+               );
+
+               // Error when wrong chain
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
                                chain_hash: genesis_block(Network::Bitcoin).header.block_hash(),
-                               full_information: true,
-                               first_blocknum: 1000,
-                               number_of_blocks: 1050,
-                               short_channel_ids: vec![0x0003e8_000000_0000,0x0003e9_000000_0000,0x0003f0_000000_0000],
-                       });
-                       assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Received reply_channel_range with invalid chain_hash");
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-               }
-
-               // Test receipt of a reply that indicates the remote node does not maintain up-to-date
-               // information for the chain_hash. Because of discrepancies in implementation we use
-               // full_information=false and short_channel_ids=[] as the signal. We should expect an error
-               // and the task should be removed.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle the reply indicating the peer was unable to fulfill our request.
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: false,
-                               first_blocknum: 1000,
-                               number_of_blocks: 100,
-                               short_channel_ids: vec![],
-                       });
-                       assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Received reply_channel_range with no information available");
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-               }
-
-               // Test receipt of a reply that has a first_blocknum that is above the first_blocknum
-               // requested in our query. The reply must contain the queried block range. We expect an
-               // error result and the task should be removed.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle the reply that has a first_blocknum above the query's first_blocknum
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1001,
-                               number_of_blocks: 100,
-                               short_channel_ids: vec![],
-                       });
-                       assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Failing reply_channel_range with invalid first_blocknum");
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-               }
-
-               // Test receipt of a first reply that does not overlap the query range at all. The first message
-               // must have some overlap with the query. We expect an error result and the task should
-               // be removed.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle a reply that contains a block range that precedes the queried block range
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
                                first_blocknum: 0,
-                               number_of_blocks: 1000,
+                               number_of_blocks: 0xffff_ffff,
+                       },
+                       false,
+                       vec![ReplyChannelRange {
+                               chain_hash: genesis_block(Network::Bitcoin).header.block_hash(),
+                               first_blocknum: 0,
+                               number_of_blocks: 0xffff_ffff,
+                               sync_complete: true,
                                short_channel_ids: vec![],
-                       });
-                       assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Failing reply_channel_range with non-overlapping first reply");
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-               }
-
-               // Test receipt of a sequence of replies with a valid first reply and a second reply that is
-               // non-sequential. The spec requires a subsequent first_blocknum to equal the prior
-               // first_blocknum plus number_of_blocks. We expect an IgnoreError result and the task should
-               // be removed.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 100);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle the first reply
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
+                       }]
+               );
+
+               // Error when first_blocknum > 0xffffff
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 0x01000000,
+                               number_of_blocks: 0xffff_ffff,
+                       },
+                       false,
+                       vec![ReplyChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 0x01000000,
+                               number_of_blocks: 0xffff_ffff,
+                               sync_complete: true,
+                               short_channel_ids: vec![]
+                       }]
+               );
+
+               // Empty reply when max valid SCID block num
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 0xffffff,
+                               number_of_blocks: 1,
+                       },
+                       true,
+                       vec![
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 0xffffff,
+                                       number_of_blocks: 1,
+                                       sync_complete: true,
+                                       short_channel_ids: vec![]
+                               },
+                       ]
+               );
+
+               // No results in valid query range
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
                                first_blocknum: 1000,
-                               number_of_blocks: 50,
-                               short_channel_ids: vec![0x0003e8_000000_0000,0x0003e9_000000_0000,0x0003f0_000000_0000],
-                       });
-                       assert!(result.is_ok());
-
-                       // Handle the second reply which does not start at the proper first_blocknum. We expect
-                       // to return an error and remove the task.
-                       let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                               chain_hash,
-                               full_information: true,
-                               first_blocknum: 1051,
-                               number_of_blocks: 50,
-                               short_channel_ids: vec![0x0003f1_000000_0000,0x0003f2_000000_0000],
-                       });
-                       assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Failing reply_channel_range with invalid sequence");
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-               }
-
-               // Test receipt of too many reply messages. We expect an IgnoreError result and the task should
-               // be removed.
-               {
-                       // Initiate a channel range query to create a query task
-                       let result = net_graph_msg_handler.query_channel_range(&node_id_1, chain_hash, 1000, 0xffff_ffff);
-                       assert!(result.is_ok());
-
-                       // Clear the SendRangeQuery event
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle a sequence of replies that will fail once the max number of reply has been exceeded.
-                       for block in 1000..=1000 + super::MAX_REPLY_CHANNEL_RANGE_PER_QUERY + 10 {
-                               let result = net_graph_msg_handler.handle_reply_channel_range(&node_id_1, &ReplyChannelRange {
-                                       chain_hash,
-                                       full_information: true,
-                                       first_blocknum: block as u32,
+                               number_of_blocks: 1000,
+                       },
+                       true,
+                       vec![
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 1000,
+                                       number_of_blocks: 1000,
+                                       sync_complete: true,
+                                       short_channel_ids: vec![],
+                               }
+                       ]
+               );
+
+               // Overflow first_blocknum + number_of_blocks
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 0xfe0000,
+                               number_of_blocks: 0xffffffff,
+                       },
+                       true,
+                       vec![
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 0xfe0000,
+                                       number_of_blocks: 0xffffffff - 0xfe0000,
+                                       sync_complete: true,
+                                       short_channel_ids: vec![
+                                               0xfffffe_ffffff_ffff, // max
+                                       ]
+                               }
+                       ]
+               );
+
+               // Single block exactly full
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 100000,
+                               number_of_blocks: 8000,
+                       },
+                       true,
+                       vec![
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 100000,
+                                       number_of_blocks: 8000,
+                                       sync_complete: true,
+                                       short_channel_ids: (100000..=107999)
+                                               .map(|block| scid_from_parts(block, 0, 0).unwrap())
+                                               .collect(),
+                               },
+                       ]
+               );
+
+               // Multiple split on new block
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 100000,
+                               number_of_blocks: 8001,
+                       },
+                       true,
+                       vec![
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 100000,
+                                       number_of_blocks: 7999,
+                                       sync_complete: false,
+                                       short_channel_ids: (100000..=107999)
+                                               .map(|block| scid_from_parts(block, 0, 0).unwrap())
+                                               .collect(),
+                               },
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 107999,
+                                       number_of_blocks: 2,
+                                       sync_complete: true,
+                                       short_channel_ids: vec![
+                                               scid_from_parts(108000, 0, 0).unwrap(),
+                                       ],
+                               }
+                       ]
+               );
+
+               // Multiple split on same block
+               do_handling_query_channel_range(
+                       &net_graph_msg_handler,
+                       &node_id_2,
+                       QueryChannelRange {
+                               chain_hash: chain_hash.clone(),
+                               first_blocknum: 100002,
+                               number_of_blocks: 8000,
+                       },
+                       true,
+                       vec![
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 100002,
+                                       number_of_blocks: 7999,
+                                       sync_complete: false,
+                                       short_channel_ids: (100002..=108001)
+                                               .map(|block| scid_from_parts(block, 0, 0).unwrap())
+                                               .collect(),
+                               },
+                               ReplyChannelRange {
+                                       chain_hash: chain_hash.clone(),
+                                       first_blocknum: 108001,
                                        number_of_blocks: 1,
-                                       short_channel_ids: vec![(block as u64) << 40],
-                               });
-                               if block <= 1000 + super::MAX_REPLY_CHANNEL_RANGE_PER_QUERY {
-                                       assert!(result.is_ok());
-                               } else if block == 1001 + super::MAX_REPLY_CHANNEL_RANGE_PER_QUERY {
-                                       assert!(result.is_err());
-                                       assert_eq!(result.err().unwrap().err, "Failing reply_channel_range due to excessive messages");
-                               } else {
-                                       assert!(result.is_err());
-                                       assert_eq!(result.err().unwrap().err, "Received unknown reply_channel_range message");
+                                       sync_complete: true,
+                                       short_channel_ids: vec![
+                                               scid_from_parts(108001, 1, 0).unwrap(),
+                                       ],
                                }
-                       }
-
-                       // Expect the task to be removed
-                       assert!(net_graph_msg_handler.chan_range_query_tasks.lock().unwrap().is_empty());
-               }
-       }
-
-       #[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 reply when no query exists. We expect an error to be returned
-               {
-                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, &ReplyShortChannelIdsEnd {
-                               chain_hash,
-                               full_information: true,
-                       });
-                       assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Unknown reply_short_channel_ids_end message");
-               }
-
-               // Test receipt of a reply that is for a different chain_hash. We expect an error and the task
-               // should be removed.
-               {
-                       // Initiate a query to create a pending query task
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id, chain_hash, vec![0x0003e8_000000_0000]);
-                       assert!(result.is_ok());
-
-                       // Process reply with incorrect chain_hash
-                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, &ReplyShortChannelIdsEnd {
-                               chain_hash: genesis_block(Network::Bitcoin).header.block_hash(),
-                               full_information: true,
-                       });
-                       assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Received reply_short_channel_ids_end with incorrect chain_hash");
-
-                       // Expect the task to be removed
-                       assert!(net_graph_msg_handler.scid_query_tasks.lock().unwrap().is_empty());
-               }
-
-               // Test receipt of a reply that indicates the peer does not maintain up-to-date information
-               // for the chain_hash requested in the query. We expect an error and task should be removed.
-               {
-                       // Initiate a query to create a pending query task
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id, chain_hash, vec![0x0003e8_000000_0000]);
+                       ]
+               );
+       }
+
+       fn do_handling_query_channel_range(
+               net_graph_msg_handler: &NetGraphMsgHandler<Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
+               test_node_id: &PublicKey,
+               msg: QueryChannelRange,
+               expected_ok: bool,
+               expected_replies: Vec<ReplyChannelRange>
+       ) {
+               let mut max_firstblocknum = msg.first_blocknum.saturating_sub(1);
+               let mut c_lightning_0_9_prev_end_blocknum = max_firstblocknum;
+               let query_end_blocknum = msg.end_blocknum();
+               let result = net_graph_msg_handler.handle_query_channel_range(test_node_id, msg);
+
+               if expected_ok {
                        assert!(result.is_ok());
-
-                       // Process failed reply
-                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, &ReplyShortChannelIdsEnd {
-                               chain_hash,
-                               full_information: false,
-                       });
+               } else {
                        assert!(result.is_err());
-                       assert_eq!(result.err().unwrap().err, "Received reply_short_channel_ids_end with no information");
-
-                       // Expect the task to be removed
-                       assert!(net_graph_msg_handler.scid_query_tasks.lock().unwrap().is_empty());
                }
 
-               // Test receipt of a successful reply when there are no additional scids to query. We expect
-               // the task to be removed.
-               {
-                       // Initiate a query to create a pending query task
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id, chain_hash, vec![0x0003e8_000000_0000]);
-                       assert!(result.is_ok());
-
-                       // Process success 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());
-
-                       // Expect the task to be removed
-                       assert!(net_graph_msg_handler.scid_query_tasks.lock().unwrap().is_empty());
-               }
-
-               // Test receipt of a successful reply when there are additional scids to query. We expect
-               // additional queries to be sent until the task can be removed.
-               {
-                       // Initiate a query to create a pending query task
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id, chain_hash, vec![0x0003e8_000000_0000]);
-                       assert!(result.is_ok());
-
-                       // Initiate a second query to add pending scids to the task
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id, chain_hash, vec![0x0003e9_000000_0000]);
-                       assert!(result.is_ok());
-                       assert_eq!(net_graph_msg_handler.scid_query_tasks.lock().unwrap().get(&node_id).unwrap().short_channel_ids, vec![0x0003e9_000000_0000]);
-
-                       // Initiate a third query to add pending scids to the task
-                       let result = net_graph_msg_handler.query_short_channel_ids(&node_id, chain_hash, vec![0x0003f0_000000_0000]);
-                       assert!(result.is_ok());
-                       assert_eq!(net_graph_msg_handler.scid_query_tasks.lock().unwrap().get(&node_id).unwrap().short_channel_ids, vec![0x0003e9_000000_0000, 0x0003f0_000000_0000]);
-
-                       // Clear all of the pending send events
-                       net_graph_msg_handler.get_and_clear_pending_msg_events();
-
-                       // Handle the first successful reply, which will send the next batch of scids in a new query
-                       let result = net_graph_msg_handler.handle_reply_short_channel_ids_end(&node_id, &ReplyShortChannelIdsEnd {
-                               chain_hash,
-                               full_information: true,
-                       });
-                       assert!(result.is_ok());
-
-                       // We expect the second batch to be sent in an event
-                       let expected_node_id = &node_id;
-                       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, expected_node_id);
-                                       assert_eq!(msg.chain_hash, chain_hash);
-                                       assert_eq!(msg.short_channel_ids, vec![0x0003e9_000000_0000, 0x0003f0_000000_0000]);
+               let events = net_graph_msg_handler.get_and_clear_pending_msg_events();
+               assert_eq!(events.len(), expected_replies.len());
+
+               for i in 0..events.len() {
+                       let expected_reply = &expected_replies[i];
+                       match &events[i] {
+                               MessageSendEvent::SendReplyChannelRange { node_id, msg } => {
+                                       assert_eq!(node_id, test_node_id);
+                                       assert_eq!(msg.chain_hash, expected_reply.chain_hash);
+                                       assert_eq!(msg.first_blocknum, expected_reply.first_blocknum);
+                                       assert_eq!(msg.number_of_blocks, expected_reply.number_of_blocks);
+                                       assert_eq!(msg.sync_complete, expected_reply.sync_complete);
+                                       assert_eq!(msg.short_channel_ids, expected_reply.short_channel_ids);
+
+                                       // Enforce exactly the sequencing requirements present on c-lightning v0.9.3
+                                       assert!(msg.first_blocknum == c_lightning_0_9_prev_end_blocknum || msg.first_blocknum == c_lightning_0_9_prev_end_blocknum.saturating_add(1));
+                                       assert!(msg.first_blocknum >= max_firstblocknum);
+                                       max_firstblocknum = msg.first_blocknum;
+                                       c_lightning_0_9_prev_end_blocknum = msg.first_blocknum.saturating_add(msg.number_of_blocks);
+
+                                       // Check that the last block count is >= the query's end_blocknum
+                                       if i == events.len() - 1 {
+                                               assert!(msg.first_blocknum.saturating_add(msg.number_of_blocks) >= query_end_blocknum);
+                                       }
                                },
-                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
+                               _ => panic!("expected MessageSendEvent::SendReplyChannelRange"),
                        }
-
-                       // We expect the scids to be cleared from the task
-                       assert_eq!(net_graph_msg_handler.scid_query_tasks.lock().unwrap().get(&node_id).unwrap().short_channel_ids.len(), 0);
-
-                       // Handle the second 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());
-
-                       // We expect the task should be removed
-                       assert!(net_graph_msg_handler.scid_query_tasks.lock().unwrap().is_empty());
                }
        }
 
        #[test]
-       fn handling_query_channel_range() {
+       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_channel_range(&node_id, &QueryChannelRange {
+               let result = net_graph_msg_handler.handle_query_short_channel_ids(&node_id, QueryShortChannelIds {
                        chain_hash,
-                       first_blocknum: 0,
-                       number_of_blocks: 0xffff_ffff,
+                       short_channel_ids: vec![0x0003e8_000000_0000],
                });
                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);
+#[cfg(all(test, feature = "unstable"))]
+mod benches {
+       use super::*;
 
-               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+       use test::Bencher;
+       use std::io::Read;
 
-               let result = net_graph_msg_handler.handle_query_short_channel_ids(&node_id, &QueryShortChannelIds {
-                       chain_hash,
-                       short_channel_ids: vec![0x0003e8_000000_0000],
+       #[bench]
+       fn read_network_graph(bench: &mut Bencher) {
+               let mut d = ::routing::router::test_utils::get_route_file().unwrap();
+               let mut v = Vec::new();
+               d.read_to_end(&mut v).unwrap();
+               bench.iter(|| {
+                       let _ = NetworkGraph::read(&mut std::io::Cursor::new(&v)).unwrap();
+               });
+       }
+
+       #[bench]
+       fn write_network_graph(bench: &mut Bencher) {
+               let mut d = ::routing::router::test_utils::get_route_file().unwrap();
+               let net_graph = NetworkGraph::read(&mut d).unwrap();
+               bench.iter(|| {
+                       let _ = net_graph.encode();
                });
-               assert!(result.is_err());
        }
 }