Implement gossip_queries sync methods in NetGraphMsgHandler
[rust-lightning] / lightning / src / routing / network_graph.rs
index 9f20219eba52a4475e21c0adc59179aeeee31a52..b0cfb982e086e1d51250981a045658092792f0de 100644 (file)
@@ -37,9 +37,21 @@ 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 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;
+
+/// 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;
+
 /// Represents the network as nodes and channels between them
 #[derive(PartialEq)]
 pub struct NetworkGraph {
@@ -64,6 +76,8 @@ pub struct NetGraphMsgHandler<C: Deref, L: Deref> where C::Target: chain::Access
        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>>,
        logger: L,
 }
 
@@ -83,6 +97,8 @@ 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,
                }
        }
@@ -96,6 +112,8 @@ 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,
                }
        }
@@ -107,6 +125,28 @@ impl<C: Deref, L: Deref> NetGraphMsgHandler<C, L> where C::Target: chain::Access
        pub fn read_locked_graph<'a>(&'a self) -> LockedNetworkGraph<'a> {
                LockedNetworkGraph(self.network_graph.read().unwrap())
        }
+
+       /// 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);
+               }
+
+               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,
+                       }
+               });
+       }
 }
 
 impl<'a> LockedNetworkGraph<'a> {
@@ -220,38 +260,270 @@ impl<C: Deref + Sync + Send, L: Deref + Sync + Send> RoutingMessageHandler for N
                }
        }
 
-       fn query_channel_range(&self, _their_node_id: &PublicKey, _chain_hash: BlockHash, _first_blocknum: u32, _number_of_blocks: u32) -> Result<(), LightningError> {
-               // TODO
-               Err(LightningError {
-                       err: String::from("Not implemented"),
-                       action: ErrorAction::IgnoreError,
-               })
+       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,
+                       });
+               }
+
+               // 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);
+
+               // Enqueue the message send event
+               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 {
+                       node_id: their_node_id.clone(),
+                       msg: QueryChannelRange {
+                               chain_hash,
+                               first_blocknum,
+                               number_of_blocks,
+                       },
+               });
+               Ok(())
        }
 
-       fn query_short_channel_ids(&self, _their_node_id: &PublicKey, _chain_hash: BlockHash, _short_channel_ids: Vec<u64>) -> Result<(), LightningError> {
-               // TODO
-               Err(LightningError {
-                       err: String::from("Not implemented"),
-                       action: ErrorAction::IgnoreError,
-               })
+       /// 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(());
+               }
+
+               // 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(());
        }
 
-       fn handle_reply_channel_range(&self, _their_node_id: &PublicKey, _msg: &ReplyChannelRange) -> Result<(), LightningError> {
-               // TODO
-               Err(LightningError {
-                       err: String::from("Not implemented"),
-                       action: ErrorAction::IgnoreError,
-               })
+       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(),);
+
+               // 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();
+
+               // 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() {
+                       return Err(LightningError {
+                               err: String::from("Received unknown reply_channel_range message"),
+                               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)
+               };
+
+               // 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,
+                       });
+               }
+
+               // 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);
+                       return Err(LightningError {
+                               err: String::from("Received reply_channel_range with no information available"),
+                               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,
+                               });
+                       }
+
+                       // 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,
+                               });
+                       }
+
+                       // 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);
+               }
+
+               // 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)?;
+                       }
+
+                       // We can remove the query range task now that the query is complete.
+                       query_range_tasks.remove(their_node_id);
+               }
+               Ok(())
        }
 
-       fn handle_reply_short_channel_ids_end(&self, _their_node_id: &PublicKey, _msg: &ReplyShortChannelIdsEnd) -> Result<(), LightningError> {
-               // TODO
-               Err(LightningError {
-                       err: String::from("Not implemented"),
-                       action: ErrorAction::IgnoreError,
-               })
+       /// 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
+                       });
+               }
+
+               // 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
+                       });
+               }
+
+               // 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 {
@@ -260,6 +532,9 @@ impl<C: Deref + Sync + Send, L: Deref + Sync + Send> RoutingMessageHandler for N
                })
        }
 
+       /// 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> {
                // TODO
                Err(LightningError {
@@ -282,6 +557,118 @@ where
        }
 }
 
+/// 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)]
 /// Details about one direction of a channel. Received
 /// within a channel update.
@@ -954,10 +1341,11 @@ mod tests {
        use routing::network_graph::{NetGraphMsgHandler, NetworkGraph};
        use ln::msgs::{OptionalField, RoutingMessageHandler, UnsignedNodeAnnouncement, NodeAnnouncement,
                UnsignedChannelAnnouncement, ChannelAnnouncement, UnsignedChannelUpdate, ChannelUpdate, HTLCFailChannelUpdate,
-               MAX_VALUE_MSAT};
+               ReplyChannelRange, ReplyShortChannelIdsEnd, QueryChannelRange, QueryShortChannelIds, MAX_VALUE_MSAT};
        use util::test_utils;
        use util::logger::Logger;
        use util::ser::{Readable, Writeable};
+       use util::events::{MessageSendEvent, MessageSendEventsProvider};
 
        use bitcoin::hashes::sha256d::Hash as Sha256dHash;
        use bitcoin::hashes::Hash;
@@ -1881,4 +2269,742 @@ mod tests {
                network.write(&mut w).unwrap();
                assert!(<NetworkGraph>::read(&mut ::std::io::Cursor::new(&w.0)).unwrap() == *network);
        }
+
+       #[test]
+       fn sending_query_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_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
+               {
+                       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));
+
+                       // It should send a query_channel_range 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_1);
+                                       assert_eq!(msg.chain_hash, chain_hash);
+                                       assert_eq!(msg.first_blocknum, first_blocknum);
+                                       assert_eq!(msg.number_of_blocks, number_of_blocks);
+                               },
+                               _ => panic!("Expected MessageSendEvent::SendChannelRangeQuery")
+                       };
+               }
+
+               // When an active query exists for the node, when there is a subsequent query request, it
+               // should fail to initiate a new query
+               {
+                       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));
+
+                       // 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() {
+               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
+               {
+                       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());
+                       assert!(result.is_ok());
+
+                       // Validate that we have enqueued a send message event and that it contains the correct information
+                       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, short_channel_ids);
+                               },
+                               _ => 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
+                       );
+               }
+       }
+
+       #[test]
+       fn handling_reply_channel_range() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey_1 = &SecretKey::from_slice(&[42; 32]).unwrap();
+               let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_privkey_1);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+
+               // Test receipt of an unknown reply message. We expect an error
+               {
+                       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: 1050,
+                               short_channel_ids: vec![
+                                       0x0003e8_000000_0000, // 1000x0x0
+                                       0x0003e9_000000_0000, // 1001x0x0
+                                       0x0003f0_000000_0000  // 1008x0x0
+                               ],
+                       });
+                       assert!(result.is_err());
+               }
+
+               // 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
+               {
+                       // 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 {
+                               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
+                               ],
+                       });
+                       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_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());
+
+                       // 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, reply_3_scids].concat());
+                               },
+                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
+                       }
+
+                       // Clean up scid_task
+                       net_graph_msg_handler.scid_query_tasks.lock().unwrap().clear();
+               }
+
+               // 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();
+
+                       // 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"),
+                       }
+
+                       // Clean up scid_task
+                       net_graph_msg_handler.scid_query_tasks.lock().unwrap().clear();
+               }
+
+               // 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 {
+                               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,
+                               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,
+                               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: 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");
+                               }
+                       }
+
+                       // 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]);
+                       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,
+                       });
+                       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]);
+                               },
+                               _ => panic!("expected MessageSendEvent::SendShortIdsQuery"),
+                       }
+
+                       // 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() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey = &SecretKey::from_slice(&[41; 32]).unwrap();
+               let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+
+               let result = net_graph_msg_handler.handle_query_channel_range(&node_id, &QueryChannelRange {
+                       chain_hash,
+                       first_blocknum: 0,
+                       number_of_blocks: 0xffff_ffff,
+               });
+               assert!(result.is_err());
+       }
+
+       #[test]
+       fn handling_query_short_channel_ids() {
+               let (secp_ctx, net_graph_msg_handler) = create_net_graph_msg_handler();
+               let node_privkey = &SecretKey::from_slice(&[41; 32]).unwrap();
+               let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
+
+               let chain_hash = genesis_block(Network::Testnet).header.block_hash();
+
+               let result = net_graph_msg_handler.handle_query_short_channel_ids(&node_id, &QueryShortChannelIds {
+                       chain_hash,
+                       short_channel_ids: vec![0x0003e8_000000_0000],
+               });
+               assert!(result.is_err());
+       }
 }