14119571714

Committed 28 Mar 2025 12:45AM UTC coverage: 84.479% (+0.09%) from 84.386%

Build # 14119571714

Build Type

push

github

Committed by

Sword-Smith

Commit Message

fix(peer_loop): Don't hold read lock responding with transction

Prior to this commit, a read-lock was held while a message was sent to a
peer. That is totally disallowed since the connection can timeout in
which case this read lock will be held for up to two minutes.

Any and all locks must be released before sending anything to a peer!

Cf. #534.

Run Details

58 of 61 new or added lines in 1 file covered. (95.08%)

4 existing lines in 3 files now uncovered.

51882 of 61414 relevant lines covered (84.48%)

175454.64 hits per line

Source File
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84.9

/src/peer_loop.rs

use std::cmp;
use std::marker::Unpin;
use std::net::SocketAddr;
use std::time::SystemTime;

use anyhow::bail;
use anyhow::Result;
use chrono::DateTime;
use chrono::Utc;
use futures::sink::Sink;
use futures::sink::SinkExt;
use futures::stream::TryStream;
use futures::stream::TryStreamExt;
use itertools::Itertools;
use rand::rngs::StdRng;
use rand::Rng;
use rand::SeedableRng;
use tasm_lib::triton_vm::prelude::Digest;
use tasm_lib::twenty_first::prelude::Mmr;
use tasm_lib::twenty_first::prelude::MmrMembershipProof;
use tasm_lib::twenty_first::util_types::mmr::mmr_accumulator::MmrAccumulator;
use tokio::select;
use tokio::sync::broadcast;
use tokio::sync::mpsc;
use tracing::debug;
use tracing::error;
use tracing::info;
use tracing::warn;

use crate::connect_to_peers::close_peer_connected_callback;
use crate::macros::fn_name;
use crate::macros::log_slow_scope;
use crate::main_loop::MAX_NUM_DIGESTS_IN_BATCH_REQUEST;
use crate::models::blockchain::block::block_height::BlockHeight;
use crate::models::blockchain::block::mutator_set_update::MutatorSetUpdate;
use crate::models::blockchain::block::Block;
use crate::models::blockchain::transaction::transaction_kernel::TransactionConfirmabilityError;
use crate::models::blockchain::transaction::Transaction;
use crate::models::channel::MainToPeerTask;
use crate::models::channel::PeerTaskToMain;
use crate::models::channel::PeerTaskToMainTransaction;
use crate::models::peer::handshake_data::HandshakeData;
use crate::models::peer::peer_info::PeerConnectionInfo;
use crate::models::peer::peer_info::PeerInfo;
use crate::models::peer::transfer_block::TransferBlock;
use crate::models::peer::BlockProposalRequest;
use crate::models::peer::BlockRequestBatch;
use crate::models::peer::IssuedSyncChallenge;
use crate::models::peer::MutablePeerState;
use crate::models::peer::NegativePeerSanction;
use crate::models::peer::PeerMessage;
use crate::models::peer::PeerSanction;
use crate::models::peer::PeerStanding;
use crate::models::peer::PositivePeerSanction;
use crate::models::peer::SyncChallenge;
use crate::models::proof_abstractions::mast_hash::MastHash;
use crate::models::proof_abstractions::timestamp::Timestamp;
use crate::models::state::block_proposal::BlockProposalRejectError;
use crate::models::state::mempool::MEMPOOL_IGNORE_TRANSACTIONS_THIS_MANY_SECS_AHEAD;
use crate::models::state::mempool::MEMPOOL_TX_THRESHOLD_AGE_IN_SECS;
use crate::models::state::GlobalState;
use crate::models::state::GlobalStateLock;
use crate::util_types::mutator_set::removal_record::RemovalRecordValidityError;

const STANDARD_BLOCK_BATCH_SIZE: usize = 250;
const MAX_PEER_LIST_LENGTH: usize = 10;
const MINIMUM_BLOCK_BATCH_SIZE: usize = 2;

const KEEP_CONNECTION_ALIVE: bool = false;
const DISCONNECT_CONNECTION: bool = true;

pub type PeerStandingNumber = i32;

/// Handles messages from peers via TCP
///
/// also handles messages from main task over the main-to-peer-tasks broadcast
/// channel.
#[derive(Debug, Clone)]
pub struct PeerLoopHandler {
    to_main_tx: mpsc::Sender<PeerTaskToMain>,
    global_state_lock: GlobalStateLock,
    peer_address: SocketAddr,
    peer_handshake_data: HandshakeData,
    inbound_connection: bool,
    distance: u8,
    rng: StdRng,
    #[cfg(test)]
    mock_now: Option<Timestamp>,
}

impl PeerLoopHandler {
    pub(crate) fn new(
        to_main_tx: mpsc::Sender<PeerTaskToMain>,
        global_state_lock: GlobalStateLock,
        peer_address: SocketAddr,
        peer_handshake_data: HandshakeData,
        inbound_connection: bool,
        distance: u8,
    ) -> Self {
        Self {
            to_main_tx,
            global_state_lock,
            peer_address,
            peer_handshake_data,
            inbound_connection,
            distance,
            rng: StdRng::from_rng(&mut rand::rng()),
            #[cfg(test)]
            mock_now: None,
        }
    }

    /// Allows for mocked timestamps such that time dependencies may be tested.
    #[cfg(test)]
    pub(crate) fn with_mocked_time(
        to_main_tx: mpsc::Sender<PeerTaskToMain>,
        global_state_lock: GlobalStateLock,
        peer_address: SocketAddr,
        peer_handshake_data: HandshakeData,
        inbound_connection: bool,
        distance: u8,
        mocked_time: Timestamp,
    ) -> Self {
        Self {
            to_main_tx,
            global_state_lock,
            peer_address,
            peer_handshake_data,
            inbound_connection,
            distance,
            mock_now: Some(mocked_time),
            rng: StdRng::from_rng(&mut rand::rng()),
        }
    }

    /// Overwrite the random number generator object with a specific one.
    ///
    /// Useful for derandomizing tests.
    #[cfg(test)]
    fn set_rng(&mut self, rng: StdRng) {
        self.rng = rng;
    }

    fn now(&self) -> Timestamp {
        #[cfg(not(test))]
        {
            Timestamp::now()
        }
        #[cfg(test)]
        {
            self.mock_now.unwrap_or(Timestamp::now())
        }
    }

    /// Punish a peer for bad behavior.
    ///
    /// Return `Err` if the peer in question is (now) banned.
    ///
    /// # Locking:
    ///   * acquires `global_state_lock` for write
    async fn punish(&mut self, reason: NegativePeerSanction) -> Result<()> {
        let mut global_state_mut = self.global_state_lock.lock_guard_mut().await;
        warn!("Punishing peer {} for {:?}", self.peer_address.ip(), reason);
        debug!(
            "Peer standing before punishment is {}",
            global_state_mut
                .net
                .peer_map
                .get(&self.peer_address)
                .unwrap()
                .standing
        );

        let Some(peer_info) = global_state_mut.net.peer_map.get_mut(&self.peer_address) else {
            bail!("Could not read peer map.");
        };
        let sanction_result = peer_info.standing.sanction(PeerSanction::Negative(reason));
        if let Err(err) = sanction_result {
            warn!("Banning peer: {err}");
        }

        sanction_result.map_err(|err| anyhow::anyhow!("Banning peer: {err}"))
    }

    /// Reward a peer for good behavior.
    ///
    /// Return `Err` if the peer in question is banned.
    ///
    /// # Locking:
    ///   * acquires `global_state_lock` for write
    async fn reward(&mut self, reason: PositivePeerSanction) -> Result<()> {
        let mut global_state_mut = self.global_state_lock.lock_guard_mut().await;
        info!("Rewarding peer {} for {:?}", self.peer_address.ip(), reason);
        let Some(peer_info) = global_state_mut.net.peer_map.get_mut(&self.peer_address) else {
            error!("Could not read peer map.");
            return Ok(());
        };
        let sanction_result = peer_info.standing.sanction(PeerSanction::Positive(reason));
        if sanction_result.is_err() {
            error!("Cannot reward banned peer");
        }

        sanction_result.map_err(|err| anyhow::anyhow!("Cannot reward banned peer: {err}"))
    }

    /// Construct a batch response, with blocks and their MMR membership proofs
    /// relative to a specified anchor.
    ///
    /// Returns `None` if the anchor has a lower leaf count than the blocks, or
    /// a block height of the response exceeds own tip height.
    async fn batch_response(
        state: &GlobalState,
        blocks: Vec<Block>,
        anchor: &MmrAccumulator,
    ) -> Option<Vec<(TransferBlock, MmrMembershipProof)>> {
        let own_tip_height = state.chain.light_state().header().height;
        let block_heights_match_anchor = blocks
            .iter()
            .all(|bl| bl.header().height < anchor.num_leafs().into());
        let block_heights_known = blocks.iter().all(|bl| bl.header().height <= own_tip_height);
        if !block_heights_match_anchor || !block_heights_known {
            let max_block_height = match blocks.iter().map(|bl| bl.header().height).max() {
                Some(height) => height.to_string(),
                None => "None".to_owned(),
            };

            debug!("max_block_height: {max_block_height}");
            debug!("own_tip_height: {own_tip_height}");
            debug!("anchor.num_leafs(): {}", anchor.num_leafs());
            debug!("block_heights_match_anchor: {block_heights_match_anchor}");
            debug!("block_heights_known: {block_heights_known}");
            return None;
        }

        let mut ret = vec![];
        for block in blocks {
            let mmr_mp = state
                .chain
                .archival_state()
                .archival_block_mmr
                .ammr()
                .prove_membership_relative_to_smaller_mmr(
                    block.header().height.into(),
                    anchor.num_leafs(),
                )
                .await;
            let block: TransferBlock = block.try_into().unwrap();
            ret.push((block, mmr_mp));
        }

        Some(ret)
    }

    /// Handle validation and send all blocks to the main task if they're all
    /// valid. Use with a list of blocks or a single block. When the
    /// `received_blocks` is a list, the parent of the `i+1`th block in the
    /// list is the `i`th block. The parent of element zero in this list is
    /// `parent_of_first_block`.
    ///
    /// # Return Value
    ///  - `Err` when the connection should be closed;
    ///  - `Ok(None)` if some block is invalid
    ///  - `Ok(None)` if the last block has insufficient cumulative PoW and we
    ///    are not syncing;
    ///  - `Ok(None)` if the last block has insufficient height and we are
    ///    syncing;
    ///  - `Ok(Some(block_height))` otherwise, referring to the block with the
    ///    highest height in the batch.
    ///
    /// A return value of Ok(Some(_)) means that the message was passed on to
    /// main loop.
    ///
    /// # Locking
    ///   * Acquires `global_state_lock` for write via `self.punish(..)` and
    ///     `self.reward(..)`.
    ///
    /// # Panics
    ///
    ///  - Panics if called with the empty list.
    async fn handle_blocks(
        &mut self,
        received_blocks: Vec<Block>,
        parent_of_first_block: Block,
    ) -> Result<Option<BlockHeight>> {
        debug!(
            "attempting to validate {} {}",
            received_blocks.len(),
            if received_blocks.len() == 1 {
                "block"
            } else {
                "blocks"
            }
        );
        let now = self.now();
        debug!("validating with respect to current timestamp {now}");
        let mut previous_block = &parent_of_first_block;
        for new_block in &received_blocks {
            let new_block_has_proof_of_work = new_block.has_proof_of_work(previous_block.header());
            debug!("new block has proof of work? {new_block_has_proof_of_work}");
            let new_block_is_valid = new_block.is_valid(previous_block, now).await;
            debug!("new block is valid? {new_block_is_valid}");
            if !new_block_has_proof_of_work {
                warn!(
                    "Received invalid proof-of-work for block of height {} from peer with IP {}",
                    new_block.kernel.header.height, self.peer_address
                );
                warn!("Difficulty is {}.", previous_block.kernel.header.difficulty);
                warn!(
                    "Proof of work should be {} (or more) but was [{}].",
                    previous_block.kernel.header.difficulty.target(),
                    new_block.hash().values().iter().join(", ")
                );
                self.punish(NegativePeerSanction::InvalidBlock((
                    new_block.kernel.header.height,
                    new_block.hash(),
                )))
                .await?;
                warn!("Failed to validate block due to insufficient PoW");
                return Ok(None);
            } else if !new_block_is_valid {
                warn!(
                    "Received invalid block of height {} from peer with IP {}",
                    new_block.kernel.header.height, self.peer_address
                );
                self.punish(NegativePeerSanction::InvalidBlock((
                    new_block.kernel.header.height,
                    new_block.hash(),
                )))
                .await?;
                warn!("Failed to validate block: invalid block");
                return Ok(None);
            }
            info!(
                "Block with height {} is valid. mined: {}",
                new_block.kernel.header.height,
                new_block.kernel.header.timestamp.standard_format()
            );

            previous_block = new_block;
        }

        // evaluate the fork choice rule
        debug!("Checking last block's canonicity ...");
        let last_block = received_blocks.last().unwrap();
        let is_canonical = self
            .global_state_lock
            .lock_guard()
            .await
            .incoming_block_is_more_canonical(last_block);
        let last_block_height = last_block.header().height;
        let sync_mode_active_and_have_new_champion = self
            .global_state_lock
            .lock_guard()
            .await
            .net
            .sync_anchor
            .as_ref()
            .is_some_and(|x| {
                x.champion
                    .is_none_or(|(height, _)| height < last_block_height)
            });
        if !is_canonical && !sync_mode_active_and_have_new_champion {
            warn!(
                "Received {} blocks from peer but incoming blocks are less \
            canonical than current tip, or current sync-champion.",
                received_blocks.len()
            );
            return Ok(None);
        }

        // Send the new blocks to the main task which handles the state update
        // and storage to the database.
        let number_of_received_blocks = received_blocks.len();
        self.to_main_tx
            .send(PeerTaskToMain::NewBlocks(received_blocks))
            .await?;
        info!(
            "Updated block info by block from peer. block height {}",
            last_block_height
        );

        // Valuable, new, hard-to-produce information. Reward peer.
        self.reward(PositivePeerSanction::ValidBlocks(number_of_received_blocks))
            .await?;

        Ok(Some(last_block_height))
    }

    /// Take a single block received from a peer and (attempt to) find a path
    /// between the received block and a common ancestor stored in the blocks
    /// database.
    ///
    /// This function attempts to find the parent of the received block, either
    /// by searching the database or by requesting it from a peer.
    ///  - If the parent is not stored, it is requested from the peer and the
    ///    received block is pushed to the fork reconciliation list for later
    ///    handling by this function. The fork reconciliation list starts out
    ///    empty, but grows as more parents are requested and transmitted.
    ///  - If the parent is found in the database, a) block handling continues:
    ///    the entire list of fork reconciliation blocks are passed down the
    ///    pipeline, potentially leading to a state update; and b) the fork
    ///    reconciliation list is cleared.
    ///
    /// Locking:
    ///   * Acquires `global_state_lock` for write via `self.punish(..)` and
    ///     `self.reward(..)`.
    async fn try_ensure_path<S>(
        &mut self,
        received_block: Box<Block>,
        peer: &mut S,
        peer_state: &mut MutablePeerState,
    ) -> Result<()>
    where
        S: Sink<PeerMessage> + TryStream<Ok = PeerMessage> + Unpin,
        <S as Sink<PeerMessage>>::Error: std::error::Error + Sync + Send + 'static,
        <S as TryStream>::Error: std::error::Error,
    {
        // Does the received block match the fork reconciliation list?
        let received_block_matches_fork_reconciliation_list = if let Some(successor) =
            peer_state.fork_reconciliation_blocks.last()
        {
            let valid = successor
                .is_valid(received_block.as_ref(), self.now())
                .await;
            if !valid {
                warn!(
                        "Fork reconciliation failed after receiving {} blocks: successor of received block is invalid",
                        peer_state.fork_reconciliation_blocks.len() + 1
                    );
            }
            valid
        } else {
            true
        };

        // Are we running out of RAM?
        let too_many_blocks = peer_state.fork_reconciliation_blocks.len() + 1
            >= self.global_state_lock.cli().sync_mode_threshold;
        if too_many_blocks {
            warn!(
                "Fork reconciliation failed after receiving {} blocks: block count exceeds sync mode threshold",
                peer_state.fork_reconciliation_blocks.len() + 1
            );
        }

        // Block mismatch or too many blocks: abort!
        if !received_block_matches_fork_reconciliation_list || too_many_blocks {
            self.punish(NegativePeerSanction::ForkResolutionError((
                received_block.header().height,
                peer_state.fork_reconciliation_blocks.len() as u16,
                received_block.hash(),
            )))
            .await?;
            peer_state.fork_reconciliation_blocks = vec![];
            return Ok(());
        }

        // otherwise, append
        peer_state.fork_reconciliation_blocks.push(*received_block);

        // Try fetch parent
        let received_block_header = *peer_state
            .fork_reconciliation_blocks
            .last()
            .unwrap()
            .header();

        let parent_digest = received_block_header.prev_block_digest;
        let parent_height = received_block_header.height.previous()
            .expect("transferred block must have previous height because genesis block cannot be transferred");
        debug!("Try ensure path: fetching parent block");
        let parent_block = self
            .global_state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .get_block(parent_digest)
            .await?;
        debug!(
            "Completed parent block fetching from DB: {}",
            if parent_block.is_some() {
                "found".to_string()
            } else {
                "not found".to_string()
            }
        );

        // If parent is not known (but not genesis) request it.
        let Some(parent_block) = parent_block else {
            if parent_height.is_genesis() {
                peer_state.fork_reconciliation_blocks.clear();
                self.punish(NegativePeerSanction::DifferentGenesis).await?;
                return Ok(());
            }
            info!(
                "Parent not known: Requesting previous block with height {} from peer",
                parent_height
            );

            peer.send(PeerMessage::BlockRequestByHash(parent_digest))
                .await?;

            return Ok(());
        };

        // We want to treat the received fork reconciliation blocks (plus the
        // received block) in reverse order, from oldest to newest, because
        // they were requested from high to low block height.
        let mut new_blocks = peer_state.fork_reconciliation_blocks.clone();
        new_blocks.reverse();

        // Reset the fork resolution state since we got all the way back to a
        // block that we have.
        let fork_reconciliation_event = !peer_state.fork_reconciliation_blocks.is_empty();
        peer_state.fork_reconciliation_blocks.clear();

        if let Some(new_block_height) = self.handle_blocks(new_blocks, parent_block).await? {
            // If `BlockNotification` was received during a block reconciliation
            // event, then the peer might have one (or more (unlikely)) blocks
            // that we do not have. We should thus request those blocks.
            if fork_reconciliation_event
                && peer_state.highest_shared_block_height > new_block_height
            {
                peer.send(PeerMessage::BlockRequestByHeight(
                    peer_state.highest_shared_block_height,
                ))
                .await?;
            }
        }

        Ok(())
    }

    /// Handle peer messages and returns Ok(true) if connection should be closed.
    /// Connection should also be closed if an error is returned.
    /// Otherwise, returns OK(false).
    ///
    /// Locking:
    ///   * Acquires `global_state_lock` for read.
    ///   * Acquires `global_state_lock` for write via `self.punish(..)` and
    ///     `self.reward(..)`.
    async fn handle_peer_message<S>(
        &mut self,
        msg: PeerMessage,
        peer: &mut S,
        peer_state_info: &mut MutablePeerState,
    ) -> Result<bool>
    where
        S: Sink<PeerMessage> + TryStream<Ok = PeerMessage> + Unpin,
        <S as Sink<PeerMessage>>::Error: std::error::Error + Sync + Send + 'static,
        <S as TryStream>::Error: std::error::Error,
    {
        debug!(
            "Received {} from peer {}",
            msg.get_type(),
            self.peer_address
        );
        match msg {
            PeerMessage::Bye => {
                // Note that the current peer is not removed from the global_state.peer_map here
                // but that this is done by the caller.
                info!("Got bye. Closing connection to peer");
                Ok(DISCONNECT_CONNECTION)
            }
            PeerMessage::PeerListRequest => {
                let peer_info = {
                    log_slow_scope!(fn_name!() + "::PeerMessage::PeerListRequest");

                    // We are interested in the address on which peers accept ingoing connections,
                    // not in the address in which they are connected to us. We are only interested in
                    // peers that accept incoming connections.
                    let mut peer_info: Vec<(SocketAddr, u128)> = self
                        .global_state_lock
                        .lock_guard()
                        .await
                        .net
                        .peer_map
                        .values()
                        .filter(|peer_info| peer_info.listen_address().is_some())
                        .take(MAX_PEER_LIST_LENGTH) // limit length of response
                        .map(|peer_info| {
                            (
                                // unwrap is safe bc of above `filter`
                                peer_info.listen_address().unwrap(),
                                peer_info.instance_id(),
                            )
                        })
                        .collect();

                    // We sort the returned list, so this function is easier to test
                    peer_info.sort_by_cached_key(|x| x.0);
                    peer_info
                };

                debug!("Responding with: {:?}", peer_info);
                peer.send(PeerMessage::PeerListResponse(peer_info)).await?;
                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::PeerListResponse(peers) => {
                log_slow_scope!(fn_name!() + "::PeerMessage::PeerListResponse");

                if peers.len() > MAX_PEER_LIST_LENGTH {
                    self.punish(NegativePeerSanction::FloodPeerListResponse)
                        .await?;
                }
                self.to_main_tx
                    .send(PeerTaskToMain::PeerDiscoveryAnswer((
                        peers,
                        self.peer_address,
                        // The distance to the revealed peers is 1 + this peer's distance
                        self.distance + 1,
                    )))
                    .await?;
                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockNotificationRequest => {
                debug!("Got BlockNotificationRequest");

                peer.send(PeerMessage::BlockNotification(
                    self.global_state_lock
                        .lock_guard()
                        .await
                        .chain
                        .light_state()
                        .into(),
                ))
                .await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockNotification(block_notification) => {
                const SYNC_CHALLENGE_COOLDOWN: Timestamp = Timestamp::minutes(10);

                let (tip_header, sync_anchor_is_set) = {
                    let state = self.global_state_lock.lock_guard().await;
                    (
                        *state.chain.light_state().header(),
                        state.net.sync_anchor.is_some(),
                    )
                };
                debug!(
                    "Got BlockNotification of height {}. Own height is {}",
                    block_notification.height, tip_header.height
                );

                let sync_mode_threshold = self.global_state_lock.cli().sync_mode_threshold;
                let now = self.now();
                let time_since_latest_successful_challenge = peer_state_info
                    .successful_sync_challenge_response_time
                    .map(|then| now - then);
                let cooldown_expired = time_since_latest_successful_challenge
                    .is_none_or(|time_passed| time_passed > SYNC_CHALLENGE_COOLDOWN);
                let exceeds_sync_mode_threshold = GlobalState::sync_mode_threshold_stateless(
                    &tip_header,
                    block_notification.height,
                    block_notification.cumulative_proof_of_work,
                    sync_mode_threshold,
                );
                if cooldown_expired && exceeds_sync_mode_threshold {
                    debug!("sync mode criterion satisfied.");

                    if peer_state_info.sync_challenge.is_some() {
                        warn!("Cannot launch new sync challenge because one is already on-going.");
                        return Ok(KEEP_CONNECTION_ALIVE);
                    }

                    info!(
                        "Peer indicates block which satisfies sync mode criterion, issuing challenge."
                    );
                    let challenge = SyncChallenge::generate(
                        &block_notification,
                        tip_header.height,
                        self.rng.random(),
                    );
                    peer_state_info.sync_challenge = Some(IssuedSyncChallenge::new(
                        challenge,
                        block_notification.cumulative_proof_of_work,
                        self.now(),
                    ));

                    debug!("sending challenge ...");
                    peer.send(PeerMessage::SyncChallenge(challenge)).await?;

                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                peer_state_info.highest_shared_block_height = block_notification.height;
                let block_is_new = tip_header.cumulative_proof_of_work
                    < block_notification.cumulative_proof_of_work;

                debug!("block_is_new: {}", block_is_new);

                if block_is_new
                    && peer_state_info.fork_reconciliation_blocks.is_empty()
                    && !sync_anchor_is_set
                    && !exceeds_sync_mode_threshold
                {
                    debug!(
                        "sending BlockRequestByHeight to peer for block with height {}",
                        block_notification.height
                    );
                    peer.send(PeerMessage::BlockRequestByHeight(block_notification.height))
                        .await?;
                } else {
                    debug!(
                        "ignoring peer block. height {}. new: {}, reconciling_fork: {}",
                        block_notification.height,
                        block_is_new,
                        !peer_state_info.fork_reconciliation_blocks.is_empty()
                    );
                }

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::SyncChallenge(sync_challenge) => {
                let response = {
                    log_slow_scope!(fn_name!() + "::PeerMessage::SyncChallenge");

                    info!("Got sync challenge from {}", self.peer_address.ip());

                    let response = self
                        .global_state_lock
                        .lock_guard()
                        .await
                        .response_to_sync_challenge(sync_challenge)
                        .await;

                    match response {
                        Ok(resp) => resp,
                        Err(e) => {
                            warn!("could not generate sync challenge response:\n{e}");
                            self.punish(NegativePeerSanction::InvalidSyncChallenge)
                                .await?;
                            return Ok(KEEP_CONNECTION_ALIVE);
                        }
                    }
                };

                info!(
                    "Responding to sync challenge from {}",
                    self.peer_address.ip()
                );
                peer.send(PeerMessage::SyncChallengeResponse(Box::new(response)))
                    .await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::SyncChallengeResponse(challenge_response) => {
                const SYNC_RESPONSE_TIMEOUT: Timestamp = Timestamp::seconds(45);

                log_slow_scope!(fn_name!() + "::PeerMessage::SyncChallengeResponse");
                info!(
                    "Got sync challenge response from {}",
                    self.peer_address.ip()
                );

                // The purpose of the sync challenge and sync challenge response
                // is to avoid going into sync mode based on a malicious target
                // fork. Instead of verifying that the claimed proof-of-work
                // number is correct (which would require sending and verifying,
                // at least, all blocks between luca (whatever that is) and the
                // claimed tip), we use a heuristic that requires less
                // communication and less verification work. The downside of
                // using a heuristic here is a nonzero false positive and false
                // negative rate. Note that the false negative event
                // (maliciously sending someone into sync mode based on a bogus
                // fork) still requires a significant amount of work from the
                // attacker, *in addition* to being lucky. Also, down the line
                // succinctness (and more specifically, recursive block
                // validation) obviates this entire subprotocol.

                // Did we issue a challenge?
                let Some(issued_challenge) = peer_state_info.sync_challenge else {
                    warn!("Sync challenge response was not prompted.");
                    self.punish(NegativePeerSanction::UnexpectedSyncChallengeResponse)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                };

                // Reset the challenge, regardless of the response's success.
                peer_state_info.sync_challenge = None;

                // Does response match issued challenge?
                if !challenge_response.matches(issued_challenge) {
                    self.punish(NegativePeerSanction::InvalidSyncChallengeResponse)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // Does response verify?
                let claimed_tip_height = challenge_response.tip.header.height;
                let now = self.now();
                if !challenge_response.is_valid(now).await {
                    self.punish(NegativePeerSanction::InvalidSyncChallengeResponse)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // Does cumulative proof-of-work evolve reasonably?
                let own_tip_header = *self
                    .global_state_lock
                    .lock_guard()
                    .await
                    .chain
                    .light_state()
                    .header();
                if !challenge_response
                    .check_pow(self.global_state_lock.cli().network, own_tip_header.height)
                {
                    self.punish(NegativePeerSanction::FishyPowEvolutionChallengeResponse)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // Is there some specific (*i.e.*, not aggregate) proof of work?
                if !challenge_response.check_difficulty(own_tip_header.difficulty) {
                    self.punish(NegativePeerSanction::FishyDifficultiesChallengeResponse)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // Did it come in time?
                if now - issued_challenge.issued_at > SYNC_RESPONSE_TIMEOUT {
                    self.punish(NegativePeerSanction::TimedOutSyncChallengeResponse)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                info!("Successful sync challenge response; relaying peer tip info to main loop.");
                peer_state_info.successful_sync_challenge_response_time = Some(now);

                let mut sync_mmra_anchor = challenge_response.tip.body.block_mmr_accumulator;
                sync_mmra_anchor.append(issued_challenge.challenge.tip_digest);

                // Inform main loop
                self.to_main_tx
                    .send(PeerTaskToMain::AddPeerMaxBlockHeight {
                        peer_address: self.peer_address,
                        claimed_height: claimed_tip_height,
                        claimed_cumulative_pow: issued_challenge.accumulated_pow,
                        claimed_block_mmra: sync_mmra_anchor,
                    })
                    .await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockRequestByHash(block_digest) => {
                match self
                    .global_state_lock
                    .lock_guard()
                    .await
                    .chain
                    .archival_state()
                    .get_block(block_digest)
                    .await?
                {
                    None => {
                        // TODO: Consider punishing here
                        warn!("Peer requested unknown block with hash {}", block_digest);
                        Ok(KEEP_CONNECTION_ALIVE)
                    }
                    Some(b) => {
                        peer.send(PeerMessage::Block(Box::new(b.try_into().unwrap())))
                            .await?;
                        Ok(KEEP_CONNECTION_ALIVE)
                    }
                }
            }
            PeerMessage::BlockRequestByHeight(block_height) => {
                let block_response = {
                    log_slow_scope!(fn_name!() + "::PeerMessage::BlockRequestByHeight");

                    debug!("Got BlockRequestByHeight of height {}", block_height);

                    let canonical_block_digest = self
                        .global_state_lock
                        .lock_guard()
                        .await
                        .chain
                        .archival_state()
                        .archival_block_mmr
                        .ammr()
                        .try_get_leaf(block_height.into())
                        .await;

                    let canonical_block_digest = match canonical_block_digest {
                        None => {
                            let own_tip_height = self
                                .global_state_lock
                                .lock_guard()
                                .await
                                .chain
                                .light_state()
                                .header()
                                .height;
                            warn!("Got block request by height ({block_height}) for unknown block. Own tip height is {own_tip_height}.");
                            self.punish(NegativePeerSanction::BlockRequestUnknownHeight)
                                .await?;

                            return Ok(KEEP_CONNECTION_ALIVE);
                        }
                        Some(digest) => digest,
                    };

                    let canonical_chain_block: Block = self
                        .global_state_lock
                        .lock_guard()
                        .await
                        .chain
                        .archival_state()
                        .get_block(canonical_block_digest)
                        .await?
                        .unwrap();

                    PeerMessage::Block(Box::new(canonical_chain_block.try_into().unwrap()))
                };

                debug!("Sending block");
                peer.send(block_response).await?;
                debug!("Sent block");
                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::Block(t_block) => {
                log_slow_scope!(fn_name!() + "::PeerMessage::Block");

                info!(
                    "Got new block from peer {}, height {}, mined {}",
                    self.peer_address,
                    t_block.header.height,
                    t_block.header.timestamp.standard_format()
                );
                let new_block_height = t_block.header.height;

                let block = match Block::try_from(*t_block) {
                    Ok(block) => Box::new(block),
                    Err(e) => {
                        warn!("Peer sent invalid block: {e:?}");
                        self.punish(NegativePeerSanction::InvalidTransferBlock)
                            .await?;

                        return Ok(KEEP_CONNECTION_ALIVE);
                    }
                };

                // Update the value for the highest known height that peer possesses iff
                // we are not in a fork reconciliation state.
                if peer_state_info.fork_reconciliation_blocks.is_empty() {
                    peer_state_info.highest_shared_block_height = new_block_height;
                }

                self.try_ensure_path(block, peer, peer_state_info).await?;

                // Reward happens as part of `try_ensure_path`

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockRequestBatch(BlockRequestBatch {
                known_blocks,
                max_response_len,
                anchor,
            }) => {
                debug!(
                    "Received BlockRequestBatch from peer {}, max_response_len: {max_response_len}",
                    self.peer_address
                );

                if known_blocks.len() > MAX_NUM_DIGESTS_IN_BATCH_REQUEST {
                    self.punish(NegativePeerSanction::BatchBlocksRequestTooManyDigests)
                        .await?;

                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // The last block in the list of the peers known block is the
                // earliest block, block with lowest height, the peer has
                // requested. If it does not belong to canonical chain, none of
                // the later will. So we can do an early abort in that case.
                let least_preferred = match known_blocks.last() {
                    Some(least_preferred) => *least_preferred,
                    None => {
                        self.punish(NegativePeerSanction::BatchBlocksRequestEmpty)
                            .await?;

                        return Ok(KEEP_CONNECTION_ALIVE);
                    }
                };

                let state = self.global_state_lock.lock_guard().await;
                let block_mmr_num_leafs = state.chain.light_state().header().height.next().into();
                let luca_is_known = state
                    .chain
                    .archival_state()
                    .block_belongs_to_canonical_chain(least_preferred)
                    .await;
                if !luca_is_known || anchor.num_leafs() > block_mmr_num_leafs {
                    drop(state);
                    self.punish(NegativePeerSanction::BatchBlocksUnknownRequest)
                        .await?;
                    peer.send(PeerMessage::UnableToSatisfyBatchRequest).await?;

                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // Happy case: At least *one* of the blocks referenced by peer
                // is known to us.
                let first_block_in_response = {
                    let mut first_block_in_response: Option<BlockHeight> = None;
                    for block_digest in known_blocks {
                        if state
                            .chain
                            .archival_state()
                            .block_belongs_to_canonical_chain(block_digest)
                            .await
                        {
                            let height = state
                                .chain
                                .archival_state()
                                .get_block_header(block_digest)
                                .await
                                .unwrap()
                                .height;
                            first_block_in_response = Some(height);
                            debug!(
                                "Found block in canonical chain for batch response: {}",
                                block_digest
                            );
                            break;
                        }
                    }

                    first_block_in_response
                        .expect("existence of LUCA should have been established already.")
                };

                debug!(
                    "Peer's most preferred block has height {first_block_in_response}.\
                 Now building response from that height."
                );

                // Get the relevant blocks, at most batch-size many, descending from the
                // peer's (alleged) most canonical block. Don't exceed `max_response_len`
                // or `STANDARD_BLOCK_BATCH_SIZE` number of blocks in response.
                let max_response_len = cmp::min(
                    max_response_len,
                    self.global_state_lock.cli().sync_mode_threshold,
                );
                let max_response_len = cmp::max(max_response_len, MINIMUM_BLOCK_BATCH_SIZE);
                let max_response_len = cmp::min(max_response_len, STANDARD_BLOCK_BATCH_SIZE);

                let mut digests_of_returned_blocks = Vec::with_capacity(max_response_len);
                let response_start_height: u64 = first_block_in_response.into();
                let mut i: u64 = 1;
                while digests_of_returned_blocks.len() < max_response_len {
                    let block_height = response_start_height + i;
                    match state
                        .chain
                        .archival_state()
                        .archival_block_mmr
                        .ammr()
                        .try_get_leaf(block_height)
                        .await
                    {
                        Some(digest) => {
                            digests_of_returned_blocks.push(digest);
                        }
                        None => break,
                    }
                    i += 1;
                }

                let mut returned_blocks: Vec<Block> =
                    Vec::with_capacity(digests_of_returned_blocks.len());
                for block_digest in digests_of_returned_blocks {
                    let block = state
                        .chain
                        .archival_state()
                        .get_block(block_digest)
                        .await?
                        .unwrap();
                    returned_blocks.push(block);
                }

                let response = Self::batch_response(&state, returned_blocks, &anchor).await;

                // issue 457. do not hold lock across a peer.send(), nor self.punish()
                drop(state);

                let Some(response) = response else {
                    warn!("Unable to satisfy batch-block request");
                    self.punish(NegativePeerSanction::BatchBlocksUnknownRequest)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                };

                debug!("Returning {} blocks in batch response", response.len());

                let response = PeerMessage::BlockResponseBatch(response);
                peer.send(response).await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockResponseBatch(authenticated_blocks) => {
                log_slow_scope!(fn_name!() + "::PeerMessage::BlockResponseBatch");

                debug!(
                    "handling block response batch with {} blocks",
                    authenticated_blocks.len()
                );

                // (Alan:) why is there even a minimum?
                if authenticated_blocks.len() < MINIMUM_BLOCK_BATCH_SIZE {
                    warn!("Got smaller batch response than allowed");
                    self.punish(NegativePeerSanction::TooShortBlockBatch)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // Verify that we are in fact in syncing mode
                // TODO: Separate peer messages into those allowed under syncing
                // and those that are not
                let Some(sync_anchor) = self
                    .global_state_lock
                    .lock_guard()
                    .await
                    .net
                    .sync_anchor
                    .clone()
                else {
                    warn!("Received a batch of blocks without being in syncing mode");
                    self.punish(NegativePeerSanction::ReceivedBatchBlocksOutsideOfSync)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                };

                // Verify that the response matches the current state
                // We get the latest block from the DB here since this message is
                // only valid for archival nodes.
                let (first_block, _) = &authenticated_blocks[0];
                let first_blocks_parent_digest: Digest = first_block.header.prev_block_digest;
                let most_canonical_own_block_match: Option<Block> = self
                    .global_state_lock
                    .lock_guard()
                    .await
                    .chain
                    .archival_state()
                    .get_block(first_blocks_parent_digest)
                    .await
                    .expect("Block lookup must succeed");
                let most_canonical_own_block_match: Block = match most_canonical_own_block_match {
                    Some(block) => block,
                    None => {
                        warn!("Got batch response with invalid start block");
                        self.punish(NegativePeerSanction::BatchBlocksInvalidStartHeight)
                            .await?;
                        return Ok(KEEP_CONNECTION_ALIVE);
                    }
                };

                // Convert all blocks to Block objects
                debug!(
                    "Found own block of height {} to match received batch",
                    most_canonical_own_block_match.kernel.header.height
                );
                let mut received_blocks = vec![];
                for (t_block, membership_proof) in authenticated_blocks {
                    let Ok(block) = Block::try_from(t_block) else {
                        warn!("Received invalid transfer block from peer");
                        self.punish(NegativePeerSanction::InvalidTransferBlock)
                            .await?;
                        return Ok(KEEP_CONNECTION_ALIVE);
                    };

                    if !membership_proof.verify(
                        block.header().height.into(),
                        block.hash(),
                        &sync_anchor.block_mmr.peaks(),
                        sync_anchor.block_mmr.num_leafs(),
                    ) {
                        warn!("Authentication of received block fails relative to anchor");
                        self.punish(NegativePeerSanction::InvalidBlockMmrAuthentication)
                            .await?;
                        return Ok(KEEP_CONNECTION_ALIVE);
                    }

                    received_blocks.push(block);
                }

                // Get the latest block that we know of and handle all received blocks
                self.handle_blocks(received_blocks, most_canonical_own_block_match)
                    .await?;

                // Reward happens as part of `handle_blocks`.

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::UnableToSatisfyBatchRequest => {
                log_slow_scope!(fn_name!() + "::PeerMessage::UnableToSatisfyBatchRequest");
                warn!(
                    "Peer {} reports inability to satisfy batch request.",
                    self.peer_address
                );

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::Handshake(_) => {
                log_slow_scope!(fn_name!() + "::PeerMessage::Handshake");

                // The handshake should have been sent during connection
                // initialization. Here it is out of order at best, malicious at
                // worst.
                self.punish(NegativePeerSanction::InvalidMessage).await?;
                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::ConnectionStatus(_) => {
                log_slow_scope!(fn_name!() + "::PeerMessage::ConnectionStatus");

                // The connection status should have been sent during connection
                // initialization. Here it is out of order at best, malicious at
                // worst.

                self.punish(NegativePeerSanction::InvalidMessage).await?;
                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::Transaction(transaction) => {
                log_slow_scope!(fn_name!() + "::PeerMessage::Transaction");

                debug!(
                    "`peer_loop` received following transaction from peer. {} inputs, {} outputs. Synced to mutator set hash: {}",
                    transaction.kernel.inputs.len(),
                    transaction.kernel.outputs.len(),
                    transaction.kernel.mutator_set_hash
                );

                let transaction: Transaction = (*transaction).into();

                // 1. If transaction is invalid, punish.
                if !transaction.is_valid().await {
                    warn!("Received invalid tx");
                    self.punish(NegativePeerSanction::InvalidTransaction)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // 2. If transaction has coinbase, punish.
                // Transactions received from peers have not been mined yet.
                // Only the miner is allowed to produce transactions with non-empty coinbase fields.
                if transaction.kernel.coinbase.is_some() {
                    warn!("Received non-mined transaction with coinbase.");
                    self.punish(NegativePeerSanction::NonMinedTransactionHasCoinbase)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // 3. If negative fee, punish.
                if transaction.kernel.fee.is_negative() {
                    warn!("Received negative-fee transaction.");
                    self.punish(NegativePeerSanction::TransactionWithNegativeFee)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // 4. If transaction is already known, ignore.
                if self
                    .global_state_lock
                    .lock_guard()
                    .await
                    .mempool
                    .contains_with_higher_proof_quality(
                        transaction.kernel.txid(),
                        transaction.proof.proof_quality()?,
                    )
                {
                    warn!("Received transaction that was already known");

                    // We received a transaction that we *probably* haven't requested.
                    // Consider punishing here, if this is abused.
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // 5. if transaction is not confirmable, punish.
                let (tip, mutator_set_accumulator_after) = {
                    let state = self.global_state_lock.lock_guard().await;

                    (
                        state.chain.light_state().hash(),
                        state.chain.light_state().mutator_set_accumulator_after(),
                    )
                };
                if !transaction.is_confirmable_relative_to(&mutator_set_accumulator_after) {
                    warn!(
                        "Received unconfirmable transaction with TXID {}. Unconfirmable because:",
                        transaction.kernel.txid()
                    );
                    // get fine-grained error code for informative logging
                    let confirmability_error_code = transaction
                        .kernel
                        .is_confirmable_relative_to(&mutator_set_accumulator_after);
                    match confirmability_error_code {
                        Ok(_) => unreachable!(),
                        Err(TransactionConfirmabilityError::InvalidRemovalRecord(index)) => {
                            warn!("invalid removal record (at index {index})");
                            let invalid_removal_record = transaction.kernel.inputs[index].clone();
                            let removal_record_error_code = invalid_removal_record
                                .validate_inner(&mutator_set_accumulator_after);
                            debug!(
                                "Absolute index set of removal record {index}: {:?}",
                                invalid_removal_record.absolute_indices
                            );
                            match removal_record_error_code {
                                Ok(_) => unreachable!(),
                                Err(RemovalRecordValidityError::AbsentAuthenticatedChunk) => {
                                    debug!("invalid because membership proof is missing");
                                }
                                Err(RemovalRecordValidityError::InvalidSwbfiMmrMp {
                                    chunk_index,
                                }) => {
                                    debug!("invalid because membership proof for chunk index {chunk_index} is invalid");
                                }
                            };
                            self.punish(NegativePeerSanction::UnconfirmableTransaction)
                                .await?;
                            return Ok(KEEP_CONNECTION_ALIVE);
                        }
                        Err(TransactionConfirmabilityError::DuplicateInputs) => {
                            warn!("duplicate inputs");
                            self.punish(NegativePeerSanction::DoubleSpendingTransaction)
                                .await?;
                            return Ok(KEEP_CONNECTION_ALIVE);
                        }
                        Err(TransactionConfirmabilityError::AlreadySpentInput(index)) => {
                            warn!("already spent input (at index {index})");
                            self.punish(NegativePeerSanction::DoubleSpendingTransaction)
                                .await?;
                            return Ok(KEEP_CONNECTION_ALIVE);
                        }
                    };
                }

                // If transaction cannot be applied to mutator set, punish.
                // I don't think this can happen when above checks pass but we include
                // the check to ensure that transaction can be applied.
                let ms_update = MutatorSetUpdate::new(
                    transaction.kernel.inputs.clone(),
                    transaction.kernel.outputs.clone(),
                );
                let can_apply = ms_update
                    .apply_to_accumulator(&mut mutator_set_accumulator_after.clone())
                    .is_ok();
                if !can_apply {
                    warn!("Cannot apply transaction to current mutator set.");
                    warn!("Transaction ID: {}", transaction.kernel.txid());
                    self.punish(NegativePeerSanction::CannotApplyTransactionToMutatorSet)
                        .await?;
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                let tx_timestamp = transaction.kernel.timestamp;

                // 6. Ignore if transaction is too old
                let now = self.now();
                if tx_timestamp < now - Timestamp::seconds(MEMPOOL_TX_THRESHOLD_AGE_IN_SECS) {
                    // TODO: Consider punishing here
                    warn!("Received too old tx");
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // 7. Ignore if transaction is too far into the future
                if tx_timestamp
                    > now + Timestamp::seconds(MEMPOOL_IGNORE_TRANSACTIONS_THIS_MANY_SECS_AHEAD)
                {
                    // TODO: Consider punishing here
                    warn!("Received tx too far into the future. Got timestamp: {tx_timestamp:?}");
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                // Otherwise, relay to main
                let pt2m_transaction = PeerTaskToMainTransaction {
                    transaction,
                    confirmable_for_block: tip,
                };
                self.to_main_tx
                    .send(PeerTaskToMain::Transaction(Box::new(pt2m_transaction)))
                    .await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::TransactionNotification(tx_notification) => {
                // addresses #457
                // new scope for state read-lock to avoid holding across peer.send()
                {
                    log_slow_scope!(fn_name!() + "::PeerMessage::TransactionNotification");

                    // 1. Ignore if we already know this transaction, and
                    // the proof quality is not higher than what we already know.
                    let state = self.global_state_lock.lock_guard().await;
                    let transaction_of_same_or_higher_proof_quality_is_known =
                        state.mempool.contains_with_higher_proof_quality(
                            tx_notification.txid,
                            tx_notification.proof_quality,
                        );
                    if transaction_of_same_or_higher_proof_quality_is_known {
                        debug!("transaction with same or higher proof quality was already known");
                        return Ok(KEEP_CONNECTION_ALIVE);
                    }

                    // Only accept transactions that do not require executing
                    // `update`.
                    if state
                        .chain
                        .light_state()
                        .mutator_set_accumulator_after()
                        .hash()
                        != tx_notification.mutator_set_hash
                    {
                        debug!("transaction refers to non-canonical mutator set state");
                        return Ok(KEEP_CONNECTION_ALIVE);
                    }
                }

                // 2. Request the actual `Transaction` from peer
                debug!("requesting transaction from peer");
                peer.send(PeerMessage::TransactionRequest(tx_notification.txid))
                    .await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::TransactionRequest(transaction_identifier) => {
                let state = self.global_state_lock.lock_guard().await;
                let Some(transaction) = state.mempool.get(transaction_identifier) else {
                    return Ok(KEEP_CONNECTION_ALIVE);
                };

                let Ok(transfer_transaction) = transaction.try_into() else {
                    warn!("Peer requested transaction that cannot be converted to transfer object");
                    return Ok(KEEP_CONNECTION_ALIVE);
                };

                // Drop state immediately to prevent holding over a response.
                drop(state);

                peer.send(PeerMessage::Transaction(Box::new(transfer_transaction)))
                    .await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockProposalNotification(block_proposal_notification) => {
                let verdict = self
                    .global_state_lock
                    .lock_guard()
                    .await
                    .favor_incoming_block_proposal(
                        block_proposal_notification.height,
                        block_proposal_notification.guesser_fee,
                    );
                match verdict {
                    Ok(_) => {
                        peer.send(PeerMessage::BlockProposalRequest(
                            BlockProposalRequest::new(block_proposal_notification.body_mast_hash),
                        ))
                        .await?
                    }
                    Err(reject_reason) => {
                        info!(
                        "Rejecting notification of block proposal with guesser fee {} from peer \
                        {}. Reason:\n{reject_reason}",
                        block_proposal_notification.guesser_fee.display_n_decimals(5),
                        self.peer_address
                    )
                    }
                }

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockProposalRequest(block_proposal_request) => {
                let matching_proposal = self
                    .global_state_lock
                    .lock_guard()
                    .await
                    .mining_state
                    .block_proposal
                    .filter(|x| x.body().mast_hash() == block_proposal_request.body_mast_hash)
                    .map(|x| x.to_owned());
                if let Some(proposal) = matching_proposal {
                    peer.send(PeerMessage::BlockProposal(Box::new(proposal)))
                        .await?;
                } else {
                    self.punish(NegativePeerSanction::BlockProposalNotFound)
                        .await?;
                }

                Ok(KEEP_CONNECTION_ALIVE)
            }
            PeerMessage::BlockProposal(block) => {
                info!("Got block proposal from peer.");

                let should_punish = {
                    log_slow_scope!(fn_name!() + "::PeerMessage::BlockProposal::should_punish");

                    let (verdict, tip) = {
                        let state = self.global_state_lock.lock_guard().await;

                        let verdict = state.favor_incoming_block_proposal(
                            block.header().height,
                            block.total_guesser_reward(),
                        );
                        let tip = state.chain.light_state().to_owned();
                        (verdict, tip)
                    };

                    if let Err(rejection_reason) = verdict {
                        match rejection_reason {
                            // no need to punish and log if the fees are equal.  we just ignore the incoming proposal.
                            BlockProposalRejectError::InsufficientFee { current, received }
                                if Some(received) == current =>
                            {
                                debug!("ignoring new block proposal because the fee is equal to the present one");
                                None
                            }
                            _ => {
                                warn!("Rejecting new block proposal:\n{rejection_reason}");
                                Some(NegativePeerSanction::NonFavorableBlockProposal)
                            }
                        }
                    } else {
                        // Verify validity and that proposal is child of current tip
                        if block.is_valid(&tip, self.now()).await {
                            None // all is well, no punishment.
                        } else {
                            Some(NegativePeerSanction::InvalidBlockProposal)
                        }
                    }
                };

                if let Some(sanction) = should_punish {
                    self.punish(sanction).await?;
                } else {
                    self.send_to_main(PeerTaskToMain::BlockProposal(block), line!())
                        .await?;

                    // Valuable, new, hard-to-produce information. Reward peer.
                    self.reward(PositivePeerSanction::NewBlockProposal).await?;
                }

                Ok(KEEP_CONNECTION_ALIVE)
            }
        }
    }

    /// send msg to main via mpsc channel `to_main_tx` and logs if slow.
    ///
    /// the channel could potentially fill up in which case the send() will
    /// block until there is capacity.  we wrap the send() so we can log if
    /// that ever happens to the extent it passes slow-scope threshold.
    async fn send_to_main(
        &self,
        msg: PeerTaskToMain,
        line: u32,
    ) -> Result<(), tokio::sync::mpsc::error::SendError<PeerTaskToMain>> {
        // we measure across the send() in case the channel ever fills up.
        log_slow_scope!(fn_name!() + &format!("peer_loop.rs:{}", line));

        self.to_main_tx.send(msg).await
    }

    /// Handle message from main task. The boolean return value indicates if
    /// the connection should be closed.
    ///
    /// Locking:
    ///   * acquires `global_state_lock` for write via Self::punish()
    async fn handle_main_task_message<S>(
        &mut self,
        msg: MainToPeerTask,
        peer: &mut S,
        peer_state_info: &mut MutablePeerState,
    ) -> Result<bool>
    where
        S: Sink<PeerMessage> + TryStream<Ok = PeerMessage> + Unpin,
        <S as Sink<PeerMessage>>::Error: std::error::Error + Sync + Send + 'static,
        <S as TryStream>::Error: std::error::Error,
    {
        debug!("Handling {} message from main in peer loop", msg.get_type());
        match msg {
            MainToPeerTask::Block(block) => {
                // We don't currently differentiate whether a new block came from a peer, or from our
                // own miner. It's always shared through this logic.
                let new_block_height = block.kernel.header.height;
                if new_block_height > peer_state_info.highest_shared_block_height {
                    debug!("Sending PeerMessage::BlockNotification");
                    peer_state_info.highest_shared_block_height = new_block_height;
                    peer.send(PeerMessage::BlockNotification(block.as_ref().into()))
                        .await?;
                    debug!("Sent PeerMessage::BlockNotification");
                }
                Ok(KEEP_CONNECTION_ALIVE)
            }
            MainToPeerTask::RequestBlockBatch(batch_block_request) => {
                // Only ask one of the peers about the batch of blocks
                if batch_block_request.peer_addr_target != self.peer_address {
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                let max_response_len = std::cmp::min(
                    STANDARD_BLOCK_BATCH_SIZE,
                    self.global_state_lock.cli().sync_mode_threshold,
                );

                peer.send(PeerMessage::BlockRequestBatch(BlockRequestBatch {
                    known_blocks: batch_block_request.known_blocks,
                    max_response_len,
                    anchor: batch_block_request.anchor_mmr,
                }))
                .await?;

                Ok(KEEP_CONNECTION_ALIVE)
            }
            MainToPeerTask::PeerSynchronizationTimeout(socket_addr) => {
                log_slow_scope!(fn_name!() + "::MainToPeerTask::PeerSynchronizationTimeout");

                if self.peer_address != socket_addr {
                    return Ok(KEEP_CONNECTION_ALIVE);
                }

                self.punish(NegativePeerSanction::SynchronizationTimeout)
                    .await?;

                // If this peer failed the last synchronization attempt, we only
                // sanction, we don't disconnect.
                Ok(KEEP_CONNECTION_ALIVE)
            }
            MainToPeerTask::MakePeerDiscoveryRequest => {
                peer.send(PeerMessage::PeerListRequest).await?;
                Ok(KEEP_CONNECTION_ALIVE)
            }
            MainToPeerTask::Disconnect(peer_address) => {
                log_slow_scope!(fn_name!() + "::MainToPeerTask::Disconnect");

                // Only disconnect from the peer the main task requested a disconnect for.
                if peer_address != self.peer_address {
                    return Ok(KEEP_CONNECTION_ALIVE);
                }
                self.register_peer_disconnection().await;

                Ok(DISCONNECT_CONNECTION)
            }
            MainToPeerTask::DisconnectAll() => {
                self.register_peer_disconnection().await;

                Ok(DISCONNECT_CONNECTION)
            }
            MainToPeerTask::MakeSpecificPeerDiscoveryRequest(target_socket_addr) => {
                if target_socket_addr == self.peer_address {
                    peer.send(PeerMessage::PeerListRequest).await?;
                }
                Ok(KEEP_CONNECTION_ALIVE)
            }
            MainToPeerTask::TransactionNotification(transaction_notification) => {
                debug!("Sending PeerMessage::TransactionNotification");
                peer.send(PeerMessage::TransactionNotification(
                    transaction_notification,
                ))
                .await?;
                debug!("Sent PeerMessage::TransactionNotification");
                Ok(KEEP_CONNECTION_ALIVE)
            }
            MainToPeerTask::BlockProposalNotification(block_proposal_notification) => {
                debug!("Sending PeerMessage::BlockProposalNotification");
                peer.send(PeerMessage::BlockProposalNotification(
                    block_proposal_notification,
                ))
                .await?;
                debug!("Sent PeerMessage::BlockProposalNotification");
                Ok(KEEP_CONNECTION_ALIVE)
            }
        }
    }

    /// Loop for the peer tasks. Awaits either a message from the peer over TCP,
    /// or a message from main over the main-to-peer-tasks broadcast channel.
    async fn run<S>(
        &mut self,
        mut peer: S,
        mut from_main_rx: broadcast::Receiver<MainToPeerTask>,
        peer_state_info: &mut MutablePeerState,
    ) -> Result<()>
    where
        S: Sink<PeerMessage> + TryStream<Ok = PeerMessage> + Unpin,
        <S as Sink<PeerMessage>>::Error: std::error::Error + Sync + Send + 'static,
        <S as TryStream>::Error: std::error::Error,
    {
        loop {
            select! {
                // Handle peer messages
                peer_message = peer.try_next() => {
                    let peer_address = self.peer_address;
                    let peer_message = match peer_message {
                        Ok(message) => message,
                        Err(err) => {
                            let msg = format!("Error when receiving from peer: {peer_address}");
                            error!("{msg}. Error: {err}");
                            bail!("{msg}. Closing connection.");
                        }
                    };
                    let Some(peer_message) = peer_message else {
                        info!("Peer {peer_address} closed connection.");
                        break;
                    };

                    let syncing =
                        self.global_state_lock.lock(|s| s.net.sync_anchor.is_some()).await;
                    let message_type = peer_message.get_type();
                    if peer_message.ignore_during_sync() && syncing {
                        debug!(
                            "Ignoring {message_type} message when syncing, from {peer_address}",
                        );
                        continue;
                    }
                    if peer_message.ignore_when_not_sync() && !syncing {
                        debug!(
                            "Ignoring {message_type} message when not syncing, from {peer_address}",
                        );
                        continue;
                    }

                    match self
                        .handle_peer_message(peer_message, &mut peer, peer_state_info)
                        .await
                    {
                        Ok(false) => {}
                        Ok(true) => {
                            info!("Closing connection to {peer_address}");
                            break;
                        }
                        Err(err) => {
                            warn!("Closing connection to {peer_address} because of error {err}.");
                            bail!("{err}");
                        }
                    };
                }

                // Handle messages from main task
                main_msg_res = from_main_rx.recv() => {
                    let main_msg = main_msg_res
                        .unwrap_or_else(|e| panic!("Failed to read from main loop: {e}"));
                    let close_connection = self
                        .handle_main_task_message(main_msg, &mut peer, peer_state_info)
                        .await
                        .unwrap_or_else(|err| {
                            warn!("handle_main_task_message returned an error: {err}");
                            true
                        });

                    if close_connection {
                        info!(
                            "handle_main_task_message is closing the connection to {}",
                            self.peer_address
                        );
                        break;
                    }
                }
            }
        }

        Ok(())
    }

    /// Function called before entering the peer loop. Reads the potentially stored
    /// peer standing from the database and does other book-keeping before entering
    /// its final resting place: the `peer_loop`. Note that the peer has already been
    /// accepted for a connection for this loop to be entered. So we don't need
    /// to check the standing again.
    ///
    /// Locking:
    ///   * acquires `global_state_lock` for write
    pub(crate) async fn run_wrapper<S>(
        &mut self,
        mut peer: S,
        from_main_rx: broadcast::Receiver<MainToPeerTask>,
    ) -> Result<()>
    where
        S: Sink<PeerMessage> + TryStream<Ok = PeerMessage> + Unpin,
        <S as Sink<PeerMessage>>::Error: std::error::Error + Sync + Send + 'static,
        <S as TryStream>::Error: std::error::Error,
    {
        const TIME_DIFFERENCE_WARN_THRESHOLD_IN_SECONDS: i128 = 120;

        let cli_args = self.global_state_lock.cli().clone();

        let standing = self
            .global_state_lock
            .lock_guard()
            .await
            .net
            .peer_databases
            .peer_standings
            .get(self.peer_address.ip())
            .await
            .unwrap_or_else(|| PeerStanding::new(cli_args.peer_tolerance));

        // Add peer to peer map
        let peer_connection_info = PeerConnectionInfo::new(
            self.peer_handshake_data.listen_port,
            self.peer_address,
            self.inbound_connection,
        );
        let new_peer = PeerInfo::new(
            peer_connection_info,
            &self.peer_handshake_data,
            SystemTime::now(),
            cli_args.peer_tolerance,
        )
        .with_standing(standing);

        // If timestamps are different, we currently just log a warning.
        let peer_clock_ahead_in_seconds = new_peer.time_difference_in_seconds();
        let own_clock_ahead_in_seconds = -peer_clock_ahead_in_seconds;
        if peer_clock_ahead_in_seconds > TIME_DIFFERENCE_WARN_THRESHOLD_IN_SECONDS
            || own_clock_ahead_in_seconds > TIME_DIFFERENCE_WARN_THRESHOLD_IN_SECONDS
        {
            let own_datetime_utc: DateTime<Utc> =
                new_peer.own_timestamp_connection_established.into();
            let peer_datetime_utc: DateTime<Utc> =
                new_peer.peer_timestamp_connection_established.into();
            warn!(
                "New peer {} disagrees with us about time. Peer reports time {} but our clock at handshake was {}.",
                new_peer.connected_address(),
                peer_datetime_utc.format("%Y-%m-%d %H:%M:%S"),
                own_datetime_utc.format("%Y-%m-%d %H:%M:%S"));
        }

        // Multiple tasks might attempt to set up a connection concurrently. So
        // even though we've checked that this connection is allowed, this check
        // could have been invalidated by another task, for one accepting an
        // incoming connection from a peer we're currently connecting to. So we
        // need to make the a check again while holding a write-lock, since
        // we're modifying `peer_map` here. Holding a read-lock doesn't work
        // since it would have to be dropped before acquiring the write-lock.
        {
            let mut global_state = self.global_state_lock.lock_guard_mut().await;
            let peer_map = &mut global_state.net.peer_map;
            if peer_map
                .values()
                .any(|pi| pi.instance_id() == self.peer_handshake_data.instance_id)
            {
                bail!("Attempted to connect to already connected peer. Aborting connection.");
            }

            if peer_map.len() >= cli_args.max_num_peers {
                bail!("Attempted to connect to more peers than allowed. Aborting connection.");
            }

            if peer_map.contains_key(&self.peer_address) {
                // This shouldn't be possible, unless the peer reports a different instance ID than
                // for the other connection. Only a malignant client would do that.
                bail!("Already connected to peer. Aborting connection");
            }

            peer_map.insert(self.peer_address, new_peer);
        }

        // `MutablePeerState` contains the part of the peer-loop's state that is mutable
        let mut peer_state = MutablePeerState::new(self.peer_handshake_data.tip_header.height);

        // If peer indicates more canonical block, request a block notification to catch up ASAP
        if self.peer_handshake_data.tip_header.cumulative_proof_of_work
            > self
                .global_state_lock
                .lock_guard()
                .await
                .chain
                .light_state()
                .kernel
                .header
                .cumulative_proof_of_work
        {
            // Send block notification request to catch up ASAP, in case we're
            // behind the newly-connected peer.
            peer.send(PeerMessage::BlockNotificationRequest).await?;
        }

        let res = self.run(peer, from_main_rx, &mut peer_state).await;
        debug!("Exited peer loop for {}", self.peer_address);

        close_peer_connected_callback(
            self.global_state_lock.clone(),
            self.peer_address,
            &self.to_main_tx,
        )
        .await;

        debug!("Ending peer loop for {}", self.peer_address);

        // Return any error that `run` returned. Returning and not suppressing errors is a quite nice
        // feature to have for testing purposes.
        res
    }

    /// Register graceful peer disconnection in the global state.
    ///
    /// See also [`NetworkingState::register_peer_disconnection`][1].
    ///
    /// # Locking:
    ///   * acquires `global_state_lock` for write
    ///
    /// [1]: crate::models::state::networking_state::NetworkingState::register_peer_disconnection
    async fn register_peer_disconnection(&mut self) {
        let peer_id = self.peer_handshake_data.instance_id;
        self.global_state_lock
            .lock_guard_mut()
            .await
            .net
            .register_peer_disconnection(peer_id, SystemTime::now());
    }
}

#[cfg(test)]
mod peer_loop_tests {
    use rand::rngs::StdRng;
    use rand::Rng;
    use rand::SeedableRng;
    use tokio::sync::mpsc::error::TryRecvError;
    use tracing_test::traced_test;

    use super::*;
    use crate::config_models::cli_args;
    use crate::config_models::network::Network;
    use crate::job_queue::triton_vm::TritonVmJobQueue;
    use crate::models::blockchain::block::block_header::TARGET_BLOCK_INTERVAL;
    use crate::models::blockchain::type_scripts::native_currency_amount::NativeCurrencyAmount;
    use crate::models::peer::peer_block_notifications::PeerBlockNotification;
    use crate::models::peer::transaction_notification::TransactionNotification;
    use crate::models::state::mempool::TransactionOrigin;
    use crate::models::state::tx_proving_capability::TxProvingCapability;
    use crate::models::state::wallet::utxo_notification::UtxoNotificationMedium;
    use crate::models::state::wallet::wallet_entropy::WalletEntropy;
    use crate::tests::shared::fake_valid_block_for_tests;
    use crate::tests::shared::fake_valid_sequence_of_blocks_for_tests;
    use crate::tests::shared::get_dummy_handshake_data_for_genesis;
    use crate::tests::shared::get_dummy_peer_connection_data_genesis;
    use crate::tests::shared::get_dummy_socket_address;
    use crate::tests::shared::get_test_genesis_setup;
    use crate::tests::shared::invalid_empty_single_proof_transaction;
    use crate::tests::shared::Action;
    use crate::tests::shared::Mock;

    #[traced_test]
    #[tokio::test]
    async fn test_peer_loop_bye() -> Result<()> {
        let mock = Mock::new(vec![Action::Read(PeerMessage::Bye)]);

        let (peer_broadcast_tx, _from_main_rx_clone, to_main_tx, _to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(Network::Alpha, 2, cli_args::Args::default()).await?;

        let peer_address = get_dummy_socket_address(2);
        let from_main_rx_clone = peer_broadcast_tx.subscribe();
        let mut peer_loop_handler =
            PeerLoopHandler::new(to_main_tx, state_lock.clone(), peer_address, hsd, true, 1);
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        assert_eq!(
            2,
            state_lock.lock_guard().await.net.peer_map.len(),
            "peer map length must be back to 2 after goodbye"
        );

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn test_peer_loop_peer_list() {
        let (peer_broadcast_tx, _from_main_rx_clone, to_main_tx, _to_main_rx1, state_lock, _hsd) =
            get_test_genesis_setup(Network::Alpha, 2, cli_args::Args::default())
                .await
                .unwrap();

        let mut peer_infos = state_lock
            .lock_guard()
            .await
            .net
            .peer_map
            .clone()
            .into_values()
            .collect::<Vec<_>>();
        peer_infos.sort_by_cached_key(|x| x.connected_address());
        let (peer_address0, instance_id0) = (
            peer_infos[0].connected_address(),
            peer_infos[0].instance_id(),
        );
        let (peer_address1, instance_id1) = (
            peer_infos[1].connected_address(),
            peer_infos[1].instance_id(),
        );

        let (hsd2, sa2) = get_dummy_peer_connection_data_genesis(Network::Alpha, 2);
        let expected_response = vec![
            (peer_address0, instance_id0),
            (peer_address1, instance_id1),
            (sa2, hsd2.instance_id),
        ];
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::PeerListRequest),
            Action::Write(PeerMessage::PeerListResponse(expected_response)),
            Action::Read(PeerMessage::Bye),
        ]);

        let from_main_rx_clone = peer_broadcast_tx.subscribe();

        let mut peer_loop_handler =
            PeerLoopHandler::new(to_main_tx, state_lock.clone(), sa2, hsd2, true, 0);
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await
            .unwrap();

        assert_eq!(
            2,
            state_lock.lock_guard().await.net.peer_map.len(),
            "peer map must have length 2 after saying goodbye to peer 2"
        );
    }

    #[traced_test]
    #[tokio::test]
    async fn different_genesis_test() -> Result<()> {
        // In this scenario a peer provides another genesis block than what has been
        // hardcoded. This should lead to the closing of the connection to this peer
        // and a ban.

        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, mut to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        assert_eq!(1000, state_lock.cli().peer_tolerance);
        let peer_address = get_dummy_socket_address(0);

        // Although the database is empty, `get_latest_block` still returns the genesis block,
        // since that block is hardcoded.
        let mut different_genesis_block = state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .get_tip()
            .await;

        different_genesis_block.set_header_nonce(StdRng::seed_from_u64(5550001).random());
        let [block_1_with_different_genesis] = fake_valid_sequence_of_blocks_for_tests(
            &different_genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;
        let mock = Mock::new(vec![Action::Read(PeerMessage::Block(Box::new(
            block_1_with_different_genesis.try_into().unwrap(),
        )))]);

        let mut peer_loop_handler = PeerLoopHandler::new(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            true,
            1,
        );
        let res = peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await;
        assert!(
            res.is_err(),
            "run_wrapper must return failure when genesis is different"
        );

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            _ => bail!("Must receive remove of peer block max height"),
        }

        // Verify that no further message was sent to main loop
        match to_main_rx1.try_recv() {
            Err(tokio::sync::mpsc::error::TryRecvError::Empty) => (),
            _ => bail!("Block notification must not be sent for block with invalid PoW"),
        };

        drop(to_main_tx);

        let peer_standing = state_lock
            .lock_guard()
            .await
            .net
            .get_peer_standing_from_database(peer_address.ip())
            .await;
        assert_eq!(
            -i32::from(state_lock.cli().peer_tolerance),
            peer_standing.unwrap().standing
        );
        assert_eq!(
            NegativePeerSanction::DifferentGenesis,
            peer_standing.unwrap().latest_punishment.unwrap().0
        );

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn node_does_not_record_disconnection_time_when_peer_initiates_disconnect() -> Result<()>
    {
        let args = cli_args::Args::default();
        let network = args.network;
        let (from_main_tx, from_main_rx, to_main_tx, to_main_rx, state_lock, _) =
            get_test_genesis_setup(network, 0, args).await?;

        let peer_address = get_dummy_socket_address(0);
        let peer_handshake_data = get_dummy_handshake_data_for_genesis(network);
        let peer_id = peer_handshake_data.instance_id;
        let mut peer_loop_handler = PeerLoopHandler::new(
            to_main_tx,
            state_lock.clone(),
            peer_address,
            peer_handshake_data,
            true,
            1,
        );
        let mock = Mock::new(vec![Action::Read(PeerMessage::Bye)]);
        peer_loop_handler.run_wrapper(mock, from_main_rx).await?;

        let global_state = state_lock.lock_guard().await;
        assert!(global_state
            .net
            .last_disconnection_time_of_peer(peer_id)
            .is_none());

        drop(to_main_rx);
        drop(from_main_tx);

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn block_without_valid_pow_test() -> Result<()> {
        // In this scenario, a block without a valid PoW is received. This block should be rejected
        // by the peer loop and a notification should never reach the main loop.

        let network = Network::Main;
        let (peer_broadcast_tx, _from_main_rx_clone, to_main_tx, mut to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let peer_address = get_dummy_socket_address(0);
        let genesis_block: Block = state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .get_tip()
            .await;

        // Make a with hash above what the implied threshold from
        let [mut block_without_valid_pow] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;

        // This *probably* is invalid PoW -- and needs to be for this test to
        // work.
        block_without_valid_pow.set_header_nonce(Digest::default());

        // Sending an invalid block will not necessarily result in a ban. This depends on the peer
        // tolerance that is set in the client. For this reason, we include a "Bye" here.
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_without_valid_pow.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let from_main_rx_clone = peer_broadcast_tx.subscribe();

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            true,
            1,
            block_without_valid_pow.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await
            .expect("sending (one) invalid block should not result in closed connection");

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            _ => bail!("Must receive remove of peer block max height"),
        }

        // Verify that no further message was sent to main loop
        match to_main_rx1.try_recv() {
            Err(tokio::sync::mpsc::error::TryRecvError::Empty) => (),
            _ => bail!("Block notification must not be sent for block with invalid PoW"),
        };

        // We need to have the transmitter in scope until we have received from it
        // otherwise the receiver will report the disconnected error when we attempt
        // to read from it. And the purpose is to verify that the channel is empty,
        // not that it has been closed.
        drop(to_main_tx);

        // Verify that peer standing was stored in database
        let standing = state_lock
            .lock_guard()
            .await
            .net
            .peer_databases
            .peer_standings
            .get(peer_address.ip())
            .await
            .unwrap();
        assert!(
            standing.standing < 0,
            "Peer must be sanctioned for sending a bad block"
        );

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn test_peer_loop_block_with_block_in_db() -> Result<()> {
        // The scenario tested here is that a client receives a block that is already
        // known and stored. The expected behavior is to ignore the block and not send
        // a message to the main task.

        let network = Network::Main;
        let (peer_broadcast_tx, _from_main_rx_clone, to_main_tx, mut to_main_rx1, mut alice, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let peer_address = get_dummy_socket_address(0);
        let genesis_block: Block = Block::genesis(network);

        let now = genesis_block.header().timestamp + Timestamp::hours(1);
        let block_1 =
            fake_valid_block_for_tests(&alice, StdRng::seed_from_u64(5550001).random()).await;
        assert!(
            block_1.is_valid(&genesis_block, now).await,
            "Block must be valid for this test to make sense"
        );
        alice.set_new_tip(block_1.clone()).await?;

        let mock_peer_messages = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_1.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let from_main_rx_clone = peer_broadcast_tx.subscribe();

        let mut alice_peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            alice.clone(),
            peer_address,
            hsd,
            false,
            1,
            block_1.header().timestamp,
        );
        alice_peer_loop_handler
            .run_wrapper(mock_peer_messages, from_main_rx_clone)
            .await?;

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            other => bail!("Must receive remove of peer block max height. Got:\n {other:?}"),
        }
        match to_main_rx1.try_recv() {
            Err(tokio::sync::mpsc::error::TryRecvError::Empty) => (),
            _ => bail!("Block notification must not be sent for block with invalid PoW"),
        };
        drop(to_main_tx);

        if !alice.lock_guard().await.net.peer_map.is_empty() {
            bail!("peer map must be empty after closing connection gracefully");
        }

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn block_request_batch_simple() {
        // Scenario: Six blocks (including genesis) are known. Peer requests
        // from all possible starting points, and client responds with the
        // correct list of blocks.
        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, _to_main_rx1, mut state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default())
                .await
                .unwrap();
        let genesis_block: Block = Block::genesis(network);
        let peer_address = get_dummy_socket_address(0);
        let [block_1, block_2, block_3, block_4, block_5] =
            fake_valid_sequence_of_blocks_for_tests(
                &genesis_block,
                Timestamp::hours(1),
                StdRng::seed_from_u64(5550001).random(),
            )
            .await;
        let blocks = vec![
            genesis_block,
            block_1,
            block_2,
            block_3,
            block_4,
            block_5.clone(),
        ];
        for block in blocks.iter().skip(1) {
            state_lock.set_new_tip(block.to_owned()).await.unwrap();
        }

        let mmra = state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .archival_block_mmr
            .ammr()
            .to_accumulator_async()
            .await;
        for i in 0..=4 {
            let expected_response = {
                let state = state_lock.lock_guard().await;
                let blocks_for_response = blocks.iter().skip(i + 1).cloned().collect_vec();
                PeerLoopHandler::batch_response(&state, blocks_for_response, &mmra)
                    .await
                    .unwrap()
            };
            let mock = Mock::new(vec![
                Action::Read(PeerMessage::BlockRequestBatch(BlockRequestBatch {
                    known_blocks: vec![blocks[i].hash()],
                    max_response_len: 14,
                    anchor: mmra.clone(),
                })),
                Action::Write(PeerMessage::BlockResponseBatch(expected_response)),
                Action::Read(PeerMessage::Bye),
            ]);
            let mut peer_loop_handler = PeerLoopHandler::new(
                to_main_tx.clone(),
                state_lock.clone(),
                peer_address,
                hsd.clone(),
                false,
                1,
            );

            peer_loop_handler
                .run_wrapper(mock, from_main_rx_clone.resubscribe())
                .await
                .unwrap();
        }
    }

    #[traced_test]
    #[tokio::test]
    async fn block_request_batch_in_order_test() -> Result<()> {
        // Scenario: A fork began at block 2, node knows two blocks of height 2 and two of height 3.
        // A peer requests a batch of blocks starting from block 1. Ensure that the correct blocks
        // are returned.

        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, _to_main_rx1, mut state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let genesis_block: Block = Block::genesis(network);
        let peer_address = get_dummy_socket_address(0);
        let [block_1, block_2_a, block_3_a] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;
        let [block_2_b, block_3_b] = fake_valid_sequence_of_blocks_for_tests(
            &block_1,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550002).random(),
        )
        .await;
        assert_ne!(block_2_b.hash(), block_2_a.hash());

        state_lock.set_new_tip(block_1.clone()).await?;
        state_lock.set_new_tip(block_2_a.clone()).await?;
        state_lock.set_new_tip(block_2_b.clone()).await?;
        state_lock.set_new_tip(block_3_b.clone()).await?;
        state_lock.set_new_tip(block_3_a.clone()).await?;

        let anchor = state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .archival_block_mmr
            .ammr()
            .to_accumulator_async()
            .await;
        let response_1 = {
            let state_lock = state_lock.lock_guard().await;
            PeerLoopHandler::batch_response(
                &state_lock,
                vec![block_1.clone(), block_2_a.clone(), block_3_a.clone()],
                &anchor,
            )
            .await
            .unwrap()
        };

        let mut mock = Mock::new(vec![
            Action::Read(PeerMessage::BlockRequestBatch(BlockRequestBatch {
                known_blocks: vec![genesis_block.hash()],
                max_response_len: 14,
                anchor: anchor.clone(),
            })),
            Action::Write(PeerMessage::BlockResponseBatch(response_1)),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler_1 = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd.clone(),
            false,
            1,
            block_3_a.header().timestamp,
        );

        peer_loop_handler_1
            .run_wrapper(mock, from_main_rx_clone.resubscribe())
            .await?;

        // Peer knows block 2_b, verify that canonical chain with 2_a is returned
        let response_2 = {
            let state_lock = state_lock.lock_guard().await;
            PeerLoopHandler::batch_response(
                &state_lock,
                vec![block_2_a, block_3_a.clone()],
                &anchor,
            )
            .await
            .unwrap()
        };
        mock = Mock::new(vec![
            Action::Read(PeerMessage::BlockRequestBatch(BlockRequestBatch {
                known_blocks: vec![block_2_b.hash(), block_1.hash(), genesis_block.hash()],
                max_response_len: 14,
                anchor,
            })),
            Action::Write(PeerMessage::BlockResponseBatch(response_2)),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler_2 = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            false,
            1,
            block_3_a.header().timestamp,
        );

        peer_loop_handler_2
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn block_request_batch_out_of_order_test() -> Result<()> {
        // Scenario: A fork began at block 2, node knows two blocks of height 2 and two of height 3.
        // A peer requests a batch of blocks starting from block 1, but the peer supplies their
        // hashes in a wrong order. Ensure that the correct blocks are returned, in the right order.
        // The blocks will be supplied in the correct order but starting from the first digest in
        // the list that is known and canonical.

        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, _to_main_rx1, mut state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let genesis_block = Block::genesis(network);
        let peer_address = get_dummy_socket_address(0);
        let [block_1, block_2_a, block_3_a] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;
        let [block_2_b, block_3_b] = fake_valid_sequence_of_blocks_for_tests(
            &block_1,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550002).random(),
        )
        .await;
        assert_ne!(block_2_a.hash(), block_2_b.hash());

        state_lock.set_new_tip(block_1.clone()).await?;
        state_lock.set_new_tip(block_2_a.clone()).await?;
        state_lock.set_new_tip(block_2_b.clone()).await?;
        state_lock.set_new_tip(block_3_b.clone()).await?;
        state_lock.set_new_tip(block_3_a.clone()).await?;

        // Peer knows block 2_b, verify that canonical chain with 2_a is returned
        let mut expected_anchor = block_3_a.body().block_mmr_accumulator.clone();
        expected_anchor.append(block_3_a.hash());
        let state_anchor = state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .archival_block_mmr
            .ammr()
            .to_accumulator_async()
            .await;
        assert_eq!(
            expected_anchor, state_anchor,
            "Catching assumption about MMRA in tip and in archival state"
        );

        let response = {
            let state_lock = state_lock.lock_guard().await;
            PeerLoopHandler::batch_response(
                &state_lock,
                vec![block_1.clone(), block_2_a, block_3_a.clone()],
                &expected_anchor,
            )
            .await
            .unwrap()
        };
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::BlockRequestBatch(BlockRequestBatch {
                known_blocks: vec![block_2_b.hash(), genesis_block.hash(), block_1.hash()],
                max_response_len: 14,
                anchor: expected_anchor,
            })),
            // Since genesis block is the 1st known in the list of known blocks,
            // it's immediate descendent, block_1, is the first one returned.
            Action::Write(PeerMessage::BlockResponseBatch(response)),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler_2 = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            false,
            1,
            block_3_a.header().timestamp,
        );

        peer_loop_handler_2
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn request_unknown_height_doesnt_crash() {
        // Scenario: Only genesis block is known. Peer requests block of height
        // 2.
        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, _to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default())
                .await
                .unwrap();
        let peer_address = get_dummy_socket_address(0);
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::BlockRequestByHeight(2.into())),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::new(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            false,
            1,
        );

        // This will return error if seen read/write order does not match that of the
        // mocked object.
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await
            .unwrap();

        // Verify that peer is sanctioned for this nonsense.
        assert!(state_lock
            .lock_guard()
            .await
            .net
            .get_peer_standing_from_database(peer_address.ip())
            .await
            .unwrap()
            .standing
            .is_negative());
    }

    #[traced_test]
    #[tokio::test]
    async fn find_canonical_chain_when_multiple_blocks_at_same_height_test() -> Result<()> {
        // Scenario: A fork began at block 2, node knows two blocks of height 2 and two of height 3.
        // A peer requests a block at height 2. Verify that the correct block at height 2 is
        // returned.

        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, _to_main_rx1, mut state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let genesis_block = Block::genesis(network);
        let peer_address = get_dummy_socket_address(0);

        let [block_1, block_2_a, block_3_a] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;
        let [block_2_b, block_3_b] = fake_valid_sequence_of_blocks_for_tests(
            &block_1,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550002).random(),
        )
        .await;
        assert_ne!(block_2_a.hash(), block_2_b.hash());

        state_lock.set_new_tip(block_1.clone()).await?;
        state_lock.set_new_tip(block_2_a.clone()).await?;
        state_lock.set_new_tip(block_2_b.clone()).await?;
        state_lock.set_new_tip(block_3_b.clone()).await?;
        state_lock.set_new_tip(block_3_a.clone()).await?;

        let mock = Mock::new(vec![
            Action::Read(PeerMessage::BlockRequestByHeight(2.into())),
            Action::Write(PeerMessage::Block(Box::new(block_2_a.try_into().unwrap()))),
            Action::Read(PeerMessage::BlockRequestByHeight(3.into())),
            Action::Write(PeerMessage::Block(Box::new(
                block_3_a.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            false,
            1,
            block_3_a.header().timestamp,
        );

        // This will return error if seen read/write order does not match that of the
        // mocked object.
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn receival_of_block_notification_height_1() {
        // Scenario: client only knows genesis block. Then receives block
        // notification of height 1. Must request block 1.
        let network = Network::Main;
        let mut rng = StdRng::seed_from_u64(5552401);
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default())
                .await
                .unwrap();
        let block_1 = fake_valid_block_for_tests(&state_lock, rng.random()).await;
        let notification_height1 = (&block_1).into();
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::BlockNotification(notification_height1)),
            Action::Write(PeerMessage::BlockRequestByHeight(1u64.into())),
            Action::Read(PeerMessage::Bye),
        ]);

        let peer_address = get_dummy_socket_address(0);
        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            false,
            1,
            block_1.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await
            .unwrap();

        drop(to_main_rx1);
    }

    #[traced_test]
    #[tokio::test]
    async fn receive_block_request_by_height_block_7() {
        // Scenario: client only knows blocks up to height 7. Then receives block-
        // request-by-height for height 7. Must respond with block 7.
        let network = Network::Main;
        let mut rng = StdRng::seed_from_u64(5552401);
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, to_main_rx1, mut state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default())
                .await
                .unwrap();
        let genesis_block = Block::genesis(network);
        let blocks: [Block; 7] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            rng.random(),
        )
        .await;
        let block7 = blocks.last().unwrap().to_owned();
        let tip_height: u64 = block7.header().height.into();
        assert_eq!(7, tip_height);

        for block in &blocks {
            state_lock.set_new_tip(block.to_owned()).await.unwrap();
        }

        let block7_response = PeerMessage::Block(Box::new(block7.try_into().unwrap()));
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::BlockRequestByHeight(7u64.into())),
            Action::Write(block7_response),
            Action::Read(PeerMessage::Bye),
        ]);

        let peer_address = get_dummy_socket_address(0);
        let mut peer_loop_handler = PeerLoopHandler::new(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            false,
            1,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await
            .unwrap();

        drop(to_main_rx1);
    }

    #[traced_test]
    #[tokio::test]
    async fn test_peer_loop_receival_of_first_block() -> Result<()> {
        // Scenario: client only knows genesis block. Then receives block 1.

        let network = Network::Main;
        let mut rng = StdRng::seed_from_u64(5550001);
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, mut to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let peer_address = get_dummy_socket_address(0);

        let block_1 = fake_valid_block_for_tests(&state_lock, rng.random()).await;
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_1.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            false,
            1,
            block_1.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        // Verify that a block was sent to `main_loop`
        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::NewBlocks(_block)) => (),
            _ => bail!("Did not find msg sent to main task"),
        };

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            _ => bail!("Must receive remove of peer block max height"),
        }

        if !state_lock.lock_guard().await.net.peer_map.is_empty() {
            bail!("peer map must be empty after closing connection gracefully");
        }

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn test_peer_loop_receival_of_second_block_no_blocks_in_db() -> Result<()> {
        // In this scenario, the client only knows the genesis block (block 0) and then
        // receives block 2, meaning that block 1 will have to be requested.

        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, mut to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let peer_address = get_dummy_socket_address(0);
        let genesis_block: Block = state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .get_tip()
            .await;
        let [block_1, block_2] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;

        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_2.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_1.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_1.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            true,
            1,
            block_2.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::NewBlocks(blocks)) => {
                if blocks[0].hash() != block_1.hash() {
                    bail!("1st received block by main loop must be block 1");
                }
                if blocks[1].hash() != block_2.hash() {
                    bail!("2nd received block by main loop must be block 2");
                }
            }
            _ => bail!("Did not find msg sent to main task 1"),
        };
        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            _ => bail!("Must receive remove of peer block max height"),
        }

        if !state_lock.lock_guard().await.net.peer_map.is_empty() {
            bail!("peer map must be empty after closing connection gracefully");
        }

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn prevent_ram_exhaustion_test() -> Result<()> {
        // In this scenario the peer sends more blocks than the client allows to store in the
        // fork-reconciliation field. This should result in abandonment of the fork-reconciliation
        // process as the alternative is that the program will crash because it runs out of RAM.

        let network = Network::Main;
        let mut rng = StdRng::seed_from_u64(5550001);
        let (
            _peer_broadcast_tx,
            from_main_rx_clone,
            to_main_tx,
            mut to_main_rx1,
            mut state_lock,
            _hsd,
        ) = get_test_genesis_setup(network, 1, cli_args::Args::default()).await?;
        let genesis_block = Block::genesis(network);

        // Restrict max number of blocks held in memory to 2.
        let mut cli = state_lock.cli().clone();
        cli.sync_mode_threshold = 2;
        state_lock.set_cli(cli).await;

        let (hsd1, peer_address1) = get_dummy_peer_connection_data_genesis(Network::Alpha, 1);
        let [block_1, _block_2, block_3, block_4] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            rng.random(),
        )
        .await;
        state_lock.set_new_tip(block_1.clone()).await?;

        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_4.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_3.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_3.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address1,
            hsd1,
            true,
            1,
            block_4.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            _ => bail!("Must receive remove of peer block max height"),
        }

        // Verify that no block is sent to main loop.
        match to_main_rx1.try_recv() {
            Err(tokio::sync::mpsc::error::TryRecvError::Empty) => (),
            _ => bail!("Peer must not handle more fork-reconciliation blocks than specified in CLI arguments"),
        };
        drop(to_main_tx);

        // Verify that peer is sanctioned for failed fork reconciliation attempt
        assert!(state_lock
            .lock_guard()
            .await
            .net
            .get_peer_standing_from_database(peer_address1.ip())
            .await
            .unwrap()
            .standing
            .is_negative());

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn test_peer_loop_receival_of_fourth_block_one_block_in_db() {
        // In this scenario, the client know the genesis block (block 0) and block 1, it
        // then receives block 4, meaning that block 3 and 2 will have to be requested.

        let network = Network::Main;
        let (
            _peer_broadcast_tx,
            from_main_rx_clone,
            to_main_tx,
            mut to_main_rx1,
            mut state_lock,
            hsd,
        ) = get_test_genesis_setup(network, 0, cli_args::Args::default())
            .await
            .unwrap();
        let peer_address: SocketAddr = get_dummy_socket_address(0);
        let genesis_block = Block::genesis(network);
        let [block_1, block_2, block_3, block_4] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;
        state_lock.set_new_tip(block_1.clone()).await.unwrap();

        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_4.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_3.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_3.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_2.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_2.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            true,
            1,
            block_4.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await
            .unwrap();

        let Some(PeerTaskToMain::NewBlocks(blocks)) = to_main_rx1.recv().await else {
            panic!("Did not find msg sent to main task");
        };
        assert_eq!(blocks[0].hash(), block_2.hash());
        assert_eq!(blocks[1].hash(), block_3.hash());
        assert_eq!(blocks[2].hash(), block_4.hash());

        let Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) = to_main_rx1.recv().await else {
            panic!("Must receive remove of peer block max height");
        };

        assert!(
            state_lock.lock_guard().await.net.peer_map.is_empty(),
            "peer map must be empty after closing connection gracefully"
        );
    }

    #[traced_test]
    #[tokio::test]
    async fn test_peer_loop_receival_of_third_block_no_blocks_in_db() -> Result<()> {
        // In this scenario, the client only knows the genesis block (block 0) and then
        // receives block 3, meaning that block 2 and 1 will have to be requested.

        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, mut to_main_rx1, state_lock, hsd) =
            get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let peer_address = get_dummy_socket_address(0);
        let genesis_block = Block::genesis(network);

        let [block_1, block_2, block_3] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;

        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_3.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_2.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_2.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_1.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_1.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_address,
            hsd,
            true,
            1,
            block_3.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::NewBlocks(blocks)) => {
                if blocks[0].hash() != block_1.hash() {
                    bail!("1st received block by main loop must be block 1");
                }
                if blocks[1].hash() != block_2.hash() {
                    bail!("2nd received block by main loop must be block 2");
                }
                if blocks[2].hash() != block_3.hash() {
                    bail!("3rd received block by main loop must be block 3");
                }
            }
            _ => bail!("Did not find msg sent to main task"),
        };
        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            _ => bail!("Must receive remove of peer block max height"),
        }

        if !state_lock.lock_guard().await.net.peer_map.is_empty() {
            bail!("peer map must be empty after closing connection gracefully");
        }

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn test_block_reconciliation_interrupted_by_block_notification() -> Result<()> {
        // In this scenario, the client know the genesis block (block 0) and block 1, it
        // then receives block 4, meaning that block 3, 2, and 1 will have to be requested.
        // But the requests are interrupted by the peer sending another message: a new block
        // notification.

        let network = Network::Main;
        let (
            _peer_broadcast_tx,
            from_main_rx_clone,
            to_main_tx,
            mut to_main_rx1,
            mut state_lock,
            hsd,
        ) = get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
        let peer_socket_address: SocketAddr = get_dummy_socket_address(0);
        let genesis_block: Block = state_lock
            .lock_guard()
            .await
            .chain
            .archival_state()
            .get_tip()
            .await;

        let [block_1, block_2, block_3, block_4, block_5] =
            fake_valid_sequence_of_blocks_for_tests(
                &genesis_block,
                Timestamp::hours(1),
                StdRng::seed_from_u64(5550001).random(),
            )
            .await;
        state_lock.set_new_tip(block_1.clone()).await?;

        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_4.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_3.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_3.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_2.hash())),
            //
            // Now make the interruption of the block reconciliation process
            Action::Read(PeerMessage::BlockNotification((&block_5).into())),
            //
            // Complete the block reconciliation process by requesting the last block
            // in this process, to get back to a mutually known block.
            Action::Read(PeerMessage::Block(Box::new(
                block_2.clone().try_into().unwrap(),
            ))),
            //
            // Then anticipate the request of the block that was announced
            // in the interruption.
            // Note that we cannot anticipate the response, as only the main
            // task writes to the database. And the database needs to be updated
            // for the handling of block 5 to be done correctly.
            Action::Write(PeerMessage::BlockRequestByHeight(
                block_5.kernel.header.height,
            )),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx.clone(),
            state_lock.clone(),
            peer_socket_address,
            hsd,
            false,
            1,
            block_5.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::NewBlocks(blocks)) => {
                if blocks[0].hash() != block_2.hash() {
                    bail!("1st received block by main loop must be block 1");
                }
                if blocks[1].hash() != block_3.hash() {
                    bail!("2nd received block by main loop must be block 2");
                }
                if blocks[2].hash() != block_4.hash() {
                    bail!("3rd received block by main loop must be block 3");
                }
            }
            _ => bail!("Did not find msg sent to main task"),
        };
        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::RemovePeerMaxBlockHeight(_)) => (),
            _ => bail!("Must receive remove of peer block max height"),
        }

        if !state_lock.lock_guard().await.net.peer_map.is_empty() {
            bail!("peer map must be empty after closing connection gracefully");
        }

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn test_block_reconciliation_interrupted_by_peer_list_request() -> Result<()> {
        // In this scenario, the client knows the genesis block (block 0) and block 1, it
        // then receives block 4, meaning that block 3, 2, and 1 will have to be requested.
        // But the requests are interrupted by the peer sending another message: a request
        // for a list of peers.

        let network = Network::Main;
        let (
            _peer_broadcast_tx,
            from_main_rx_clone,
            to_main_tx,
            mut to_main_rx1,
            mut state_lock,
            _hsd,
        ) = get_test_genesis_setup(network, 1, cli_args::Args::default()).await?;
        let genesis_block = Block::genesis(network);
        let peer_infos: Vec<PeerInfo> = state_lock
            .lock_guard()
            .await
            .net
            .peer_map
            .clone()
            .into_values()
            .collect::<Vec<_>>();

        let [block_1, block_2, block_3, block_4] = fake_valid_sequence_of_blocks_for_tests(
            &genesis_block,
            Timestamp::hours(1),
            StdRng::seed_from_u64(5550001).random(),
        )
        .await;
        state_lock.set_new_tip(block_1.clone()).await?;

        let (hsd_1, sa_1) = get_dummy_peer_connection_data_genesis(network, 1);
        let expected_peer_list_resp = vec![
            (
                peer_infos[0].listen_address().unwrap(),
                peer_infos[0].instance_id(),
            ),
            (sa_1, hsd_1.instance_id),
        ];
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::Block(Box::new(
                block_4.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_3.hash())),
            Action::Read(PeerMessage::Block(Box::new(
                block_3.clone().try_into().unwrap(),
            ))),
            Action::Write(PeerMessage::BlockRequestByHash(block_2.hash())),
            //
            // Now make the interruption of the block reconciliation process
            Action::Read(PeerMessage::PeerListRequest),
            //
            // Answer the request for a peer list
            Action::Write(PeerMessage::PeerListResponse(expected_peer_list_resp)),
            //
            // Complete the block reconciliation process by requesting the last block
            // in this process, to get back to a mutually known block.
            Action::Read(PeerMessage::Block(Box::new(
                block_2.clone().try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx,
            state_lock.clone(),
            sa_1,
            hsd_1,
            true,
            1,
            block_4.header().timestamp,
        );
        peer_loop_handler
            .run_wrapper(mock, from_main_rx_clone)
            .await?;

        // Verify that blocks are sent to `main_loop` in expected ordering
        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::NewBlocks(blocks)) => {
                if blocks[0].hash() != block_2.hash() {
                    bail!("1st received block by main loop must be block 1");
                }
                if blocks[1].hash() != block_3.hash() {
                    bail!("2nd received block by main loop must be block 2");
                }
                if blocks[2].hash() != block_4.hash() {
                    bail!("3rd received block by main loop must be block 3");
                }
            }
            _ => bail!("Did not find msg sent to main task"),
        };

        assert_eq!(
            1,
            state_lock.lock_guard().await.net.peer_map.len(),
            "One peer must remain in peer list after peer_1 closed gracefully"
        );

        Ok(())
    }

    #[traced_test]
    #[tokio::test]
    async fn receive_transaction_request() {
        let network = Network::Main;
        let dummy_tx = invalid_empty_single_proof_transaction();
        let txid = dummy_tx.kernel.txid();

        for transaction_is_known in [false, true] {
            let (_peer_broadcast_tx, from_main_rx, to_main_tx, _, mut state_lock, _hsd) =
                get_test_genesis_setup(network, 1, cli_args::Args::default())
                    .await
                    .unwrap();
            if transaction_is_known {
                state_lock
                    .lock_guard_mut()
                    .await
                    .mempool_insert(dummy_tx.clone(), TransactionOrigin::Own)
                    .await;
            }

            let mock = if transaction_is_known {
                Mock::new(vec![
                    Action::Read(PeerMessage::TransactionRequest(txid)),
                    Action::Write(PeerMessage::Transaction(Box::new(
                        (&dummy_tx).try_into().unwrap(),
                    ))),
                    Action::Read(PeerMessage::Bye),
                ])
            } else {
                Mock::new(vec![
                    Action::Read(PeerMessage::TransactionRequest(txid)),
                    Action::Read(PeerMessage::Bye),
                ])
            };

            let hsd = get_dummy_handshake_data_for_genesis(network);
            let mut peer_state = MutablePeerState::new(hsd.tip_header.height);
            let mut peer_loop_handler = PeerLoopHandler::new(
                to_main_tx,
                state_lock,
                get_dummy_socket_address(0),
                hsd,
                true,
                1,
            );

            peer_loop_handler
                .run(mock, from_main_rx, &mut peer_state)
                .await
                .unwrap();
        }
    }

    #[traced_test]
    #[tokio::test]
    async fn empty_mempool_request_tx_test() {
        // In this scenario the client receives a transaction notification from
        // a peer of a transaction it doesn't know; the client must then request it.

        let network = Network::Main;
        let (_peer_broadcast_tx, from_main_rx_clone, to_main_tx, mut to_main_rx1, state_lock, _hsd) =
            get_test_genesis_setup(network, 1, cli_args::Args::default())
                .await
                .unwrap();

        let spending_key = state_lock
            .lock_guard()
            .await
            .wallet_state
            .wallet_entropy
            .nth_symmetric_key_for_tests(0);
        let genesis_block = Block::genesis(network);
        let now = genesis_block.kernel.header.timestamp;
        let (transaction_1, _, _change_output) = state_lock
            .lock_guard()
            .await
            .create_transaction_with_prover_capability(
                Default::default(),
                spending_key.into(),
                UtxoNotificationMedium::OffChain,
                NativeCurrencyAmount::coins(0),
                now,
                TxProvingCapability::ProofCollection,
                &TritonVmJobQueue::dummy(),
            )
            .await
            .unwrap();

        // Build the resulting transaction notification
        let tx_notification: TransactionNotification = (&transaction_1).try_into().unwrap();
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::TransactionNotification(tx_notification)),
            Action::Write(PeerMessage::TransactionRequest(tx_notification.txid)),
            Action::Read(PeerMessage::Transaction(Box::new(
                (&transaction_1).try_into().unwrap(),
            ))),
            Action::Read(PeerMessage::Bye),
        ]);

        let (hsd_1, _sa_1) = get_dummy_peer_connection_data_genesis(network, 1);

        // Mock a timestamp to allow transaction to be considered valid
        let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
            to_main_tx,
            state_lock.clone(),
            get_dummy_socket_address(0),
            hsd_1.clone(),
            true,
            1,
            now,
        );

        let mut peer_state = MutablePeerState::new(hsd_1.tip_header.height);

        assert!(
            state_lock.lock_guard().await.mempool.is_empty(),
            "Mempool must be empty at init"
        );
        peer_loop_handler
            .run(mock, from_main_rx_clone, &mut peer_state)
            .await
            .unwrap();

        // Transaction must be sent to `main_loop`. The transaction is stored to the mempool
        // by the `main_loop`.
        match to_main_rx1.recv().await {
            Some(PeerTaskToMain::Transaction(_)) => (),
            _ => panic!("Must receive remove of peer block max height"),
        };
    }

    #[traced_test]
    #[tokio::test]
    async fn populated_mempool_request_tx_test() -> Result<()> {
        // In this scenario the peer is informed of a transaction that it already knows

        let network = Network::Main;
        let (
            _peer_broadcast_tx,
            from_main_rx_clone,
            to_main_tx,
            mut to_main_rx1,
            mut state_lock,
            _hsd,
        ) = get_test_genesis_setup(network, 1, cli_args::Args::default())
            .await
            .unwrap();
        let spending_key = state_lock
            .lock_guard()
            .await
            .wallet_state
            .wallet_entropy
            .nth_symmetric_key_for_tests(0);

        let genesis_block = Block::genesis(network);
        let now = genesis_block.kernel.header.timestamp;
        let (transaction_1, _, _change_output) = state_lock
            .lock_guard()
            .await
            .create_transaction_with_prover_capability(
                Default::default(),
                spending_key.into(),
                UtxoNotificationMedium::OffChain,
                NativeCurrencyAmount::coins(0),
                now,
                TxProvingCapability::ProofCollection,
                &TritonVmJobQueue::dummy(),
            )
            .await
            .unwrap();

        let (hsd_1, _sa_1) = get_dummy_peer_connection_data_genesis(network, 1);
        let mut peer_loop_handler = PeerLoopHandler::new(
            to_main_tx,
            state_lock.clone(),
            get_dummy_socket_address(0),
            hsd_1.clone(),
            true,
            1,
        );
        let mut peer_state = MutablePeerState::new(hsd_1.tip_header.height);

        assert!(
            state_lock.lock_guard().await.mempool.is_empty(),
            "Mempool must be empty at init"
        );
        state_lock
            .lock_guard_mut()
            .await
            .mempool_insert(transaction_1.clone(), TransactionOrigin::Foreign)
            .await;
        assert!(
            !state_lock.lock_guard().await.mempool.is_empty(),
            "Mempool must be non-empty after insertion"
        );

        // Run the peer loop and verify expected exchange -- namely that the
        // tx notification is received and the the transaction is *not*
        // requested.
        let tx_notification: TransactionNotification = (&transaction_1).try_into().unwrap();
        let mock = Mock::new(vec![
            Action::Read(PeerMessage::TransactionNotification(tx_notification)),
            Action::Read(PeerMessage::Bye),
        ]);
        peer_loop_handler
            .run(mock, from_main_rx_clone, &mut peer_state)
            .await
            .unwrap();

        // nothing is allowed to be sent to `main_loop`
        match to_main_rx1.try_recv() {
            Err(TryRecvError::Empty) => (),
            Err(TryRecvError::Disconnected) => panic!("to_main channel must still be open"),
            Ok(_) => panic!("to_main channel must be empty"),
        };
        Ok(())
    }

    mod block_proposals {
        use super::*;
        use crate::tests::shared::get_dummy_handshake_data_for_genesis;

        struct TestSetup {
            peer_loop_handler: PeerLoopHandler,
            to_main_rx: mpsc::Receiver<PeerTaskToMain>,
            from_main_rx: broadcast::Receiver<MainToPeerTask>,
            peer_state: MutablePeerState,
            to_main_tx: mpsc::Sender<PeerTaskToMain>,
            genesis_block: Block,
            peer_broadcast_tx: broadcast::Sender<MainToPeerTask>,
        }

        async fn genesis_setup(network: Network) -> TestSetup {
            let (peer_broadcast_tx, from_main_rx, to_main_tx, to_main_rx, alice, _hsd) =
                get_test_genesis_setup(network, 0, cli_args::Args::default())
                    .await
                    .unwrap();
            let peer_hsd = get_dummy_handshake_data_for_genesis(network);
            let peer_loop_handler = PeerLoopHandler::new(
                to_main_tx.clone(),
                alice.clone(),
                get_dummy_socket_address(0),
                peer_hsd.clone(),
                true,
                1,
            );
            let peer_state = MutablePeerState::new(peer_hsd.tip_header.height);

            // (peer_loop_handler, to_main_rx1)
            TestSetup {
                peer_broadcast_tx,
                peer_loop_handler,
                to_main_rx,
                from_main_rx,
                peer_state,
                to_main_tx,
                genesis_block: Block::genesis(network),
            }
        }

        #[traced_test]
        #[tokio::test]
        async fn accept_block_proposal_height_one() {
            // Node knows genesis block, receives a block proposal for block 1
            // and must accept this. Verify that main loop is informed of block
            // proposal.
            let TestSetup {
                peer_broadcast_tx,
                mut peer_loop_handler,
                mut to_main_rx,
                from_main_rx,
                mut peer_state,
                to_main_tx,
                genesis_block,
            } = genesis_setup(Network::Main).await;
            let block1 = fake_valid_block_for_tests(
                &peer_loop_handler.global_state_lock,
                StdRng::seed_from_u64(5550001).random(),
            )
            .await;

            let mock = Mock::new(vec![
                Action::Read(PeerMessage::BlockProposal(Box::new(block1))),
                Action::Read(PeerMessage::Bye),
            ]);
            peer_loop_handler
                .run(mock, from_main_rx, &mut peer_state)
                .await
                .unwrap();

            match to_main_rx.try_recv().unwrap() {
                PeerTaskToMain::BlockProposal(block) => {
                    assert_eq!(genesis_block.hash(), block.header().prev_block_digest);
                }
                _ => panic!("Expected main loop to be informed of block proposal"),
            };

            drop(to_main_tx);
            drop(peer_broadcast_tx);
        }

        #[traced_test]
        #[tokio::test]
        async fn accept_block_proposal_notification_height_one() {
            // Node knows genesis block, receives a block proposal notification
            // for block 1 and must accept this by requesting the block
            // proposal from peer.
            let TestSetup {
                peer_broadcast_tx,
                mut peer_loop_handler,
                to_main_rx: _,
                from_main_rx,
                mut peer_state,
                to_main_tx,
                ..
            } = genesis_setup(Network::Main).await;
            let block1 = fake_valid_block_for_tests(
                &peer_loop_handler.global_state_lock,
                StdRng::seed_from_u64(5550001).random(),
            )
            .await;

            let mock = Mock::new(vec![
                Action::Read(PeerMessage::BlockProposalNotification((&block1).into())),
                Action::Write(PeerMessage::BlockProposalRequest(
                    BlockProposalRequest::new(block1.body().mast_hash()),
                )),
                Action::Read(PeerMessage::Bye),
            ]);
            peer_loop_handler
                .run(mock, from_main_rx, &mut peer_state)
                .await
                .unwrap();

            drop(to_main_tx);
            drop(peer_broadcast_tx);
        }
    }

    mod proof_qualities {
        use strum::IntoEnumIterator;

        use super::*;
        use crate::config_models::cli_args;
        use crate::models::blockchain::transaction::Transaction;
        use crate::models::peer::transfer_transaction::TransactionProofQuality;
        use crate::tests::shared::mock_genesis_global_state;

        async fn tx_of_proof_quality(
            network: Network,
            quality: TransactionProofQuality,
        ) -> Transaction {
            let wallet_secret = WalletEntropy::devnet_wallet();
            let alice_key = wallet_secret.nth_generation_spending_key_for_tests(0);
            let alice =
                mock_genesis_global_state(network, 1, wallet_secret, cli_args::Args::default())
                    .await;
            let alice = alice.lock_guard().await;
            let genesis_block = alice.chain.light_state();
            let in_seven_months = genesis_block.header().timestamp + Timestamp::months(7);
            let prover_capability = match quality {
                TransactionProofQuality::ProofCollection => TxProvingCapability::ProofCollection,
                TransactionProofQuality::SingleProof => TxProvingCapability::SingleProof,
            };
            alice
                .create_transaction_with_prover_capability(
                    vec![].into(),
                    alice_key.into(),
                    UtxoNotificationMedium::OffChain,
                    NativeCurrencyAmount::coins(1),
                    in_seven_months,
                    prover_capability,
                    &TritonVmJobQueue::dummy(),
                )
                .await
                .unwrap()
                .0
        }

        #[traced_test]
        #[tokio::test]
        async fn client_favors_higher_proof_quality() {
            // In this scenario the peer is informed of a transaction that it
            // already knows, and it's tested that it checks the proof quality
            // field and verifies that it exceeds the proof in the mempool
            // before requesting the transasction.
            let network = Network::Main;
            let proof_collection_tx =
                tx_of_proof_quality(network, TransactionProofQuality::ProofCollection).await;
            let single_proof_tx =
                tx_of_proof_quality(network, TransactionProofQuality::SingleProof).await;

            for (own_tx_pq, new_tx_pq) in
                TransactionProofQuality::iter().cartesian_product(TransactionProofQuality::iter())
            {
                use TransactionProofQuality::*;

                let (
                    _peer_broadcast_tx,
                    from_main_rx_clone,
                    to_main_tx,
                    mut to_main_rx1,
                    mut alice,
                    handshake_data,
                ) = get_test_genesis_setup(network, 1, cli_args::Args::default())
                    .await
                    .unwrap();

                let (own_tx, new_tx) = match (own_tx_pq, new_tx_pq) {
                    (ProofCollection, ProofCollection) => {
                        (&proof_collection_tx, &proof_collection_tx)
                    }
                    (ProofCollection, SingleProof) => (&proof_collection_tx, &single_proof_tx),
                    (SingleProof, ProofCollection) => (&single_proof_tx, &proof_collection_tx),
                    (SingleProof, SingleProof) => (&single_proof_tx, &single_proof_tx),
                };

                alice
                    .lock_guard_mut()
                    .await
                    .mempool_insert(own_tx.to_owned(), TransactionOrigin::Foreign)
                    .await;

                let tx_notification: TransactionNotification = new_tx.try_into().unwrap();

                let own_proof_is_supreme = own_tx_pq >= new_tx_pq;
                let mock = if own_proof_is_supreme {
                    Mock::new(vec![
                        Action::Read(PeerMessage::TransactionNotification(tx_notification)),
                        Action::Read(PeerMessage::Bye),
                    ])
                } else {
                    Mock::new(vec![
                        Action::Read(PeerMessage::TransactionNotification(tx_notification)),
                        Action::Write(PeerMessage::TransactionRequest(tx_notification.txid)),
                        Action::Read(PeerMessage::Transaction(Box::new(
                            new_tx.try_into().unwrap(),
                        ))),
                        Action::Read(PeerMessage::Bye),
                    ])
                };

                let now = proof_collection_tx.kernel.timestamp;
                let mut peer_loop_handler = PeerLoopHandler::with_mocked_time(
                    to_main_tx,
                    alice.clone(),
                    get_dummy_socket_address(0),
                    handshake_data.clone(),
                    true,
                    1,
                    now,
                );
                let mut peer_state = MutablePeerState::new(handshake_data.tip_header.height);

                peer_loop_handler
                    .run(mock, from_main_rx_clone, &mut peer_state)
                    .await
                    .unwrap();

                if own_proof_is_supreme {
                    match to_main_rx1.try_recv() {
                        Err(TryRecvError::Empty) => (),
                        Err(TryRecvError::Disconnected) => {
                            panic!("to_main channel must still be open")
                        }
                        Ok(_) => panic!("to_main channel must be empty"),
                    }
                } else {
                    match to_main_rx1.try_recv() {
                        Err(TryRecvError::Empty) => panic!("Transaction must be sent to main loop"),
                        Err(TryRecvError::Disconnected) => {
                            panic!("to_main channel must still be open")
                        }
                        Ok(PeerTaskToMain::Transaction(_)) => (),
                        _ => panic!("Unexpected result from channel"),
                    }
                }
            }
        }
    }

    mod sync_challenges {
        use super::*;
        use crate::tests::shared::fake_valid_sequence_of_blocks_for_tests_dyn;

        #[traced_test]
        #[tokio::test]
        async fn bad_sync_challenge_height_greater_than_tip() {
            // Criterium: Challenge height may not exceed that of tip in the
            // request.

            let network = Network::Main;
            let (
                _alice_main_to_peer_tx,
                alice_main_to_peer_rx,
                alice_peer_to_main_tx,
                alice_peer_to_main_rx,
                mut alice,
                alice_hsd,
            ) = get_test_genesis_setup(network, 0, cli_args::Args::default())
                .await
                .unwrap();
            let genesis_block: Block = Block::genesis(network);
            let blocks: [Block; 11] = fake_valid_sequence_of_blocks_for_tests(
                &genesis_block,
                Timestamp::hours(1),
                [0u8; 32],
            )
            .await;
            for block in &blocks {
                alice.set_new_tip(block.clone()).await.unwrap();
            }

            let bh12 = blocks.last().unwrap().header().height;
            let sync_challenge = SyncChallenge {
                tip_digest: blocks[9].hash(),
                challenges: [bh12; 10],
            };
            let alice_p2p_messages = Mock::new(vec![
                Action::Read(PeerMessage::SyncChallenge(sync_challenge)),
                Action::Read(PeerMessage::Bye),
            ]);

            let peer_address = get_dummy_socket_address(0);
            let mut alice_peer_loop_handler = PeerLoopHandler::new(
                alice_peer_to_main_tx.clone(),
                alice.clone(),
                peer_address,
                alice_hsd,
                false,
                1,
            );
            alice_peer_loop_handler
                .run_wrapper(alice_p2p_messages, alice_main_to_peer_rx)
                .await
                .unwrap();

            drop(alice_peer_to_main_rx);

            let latest_sanction = alice
                .lock_guard()
                .await
                .net
                .get_peer_standing_from_database(peer_address.ip())
                .await
                .unwrap();
            assert_eq!(
                NegativePeerSanction::InvalidSyncChallenge,
                latest_sanction
                    .latest_punishment
                    .expect("peer must be sanctioned")
                    .0
            );
        }

        #[traced_test]
        #[tokio::test]
        async fn bad_sync_challenge_genesis_block_doesnt_crash_client() {
            // Criterium: Challenge may not point to genesis block, or block 1, as
            // tip.

            let network = Network::Main;
            let genesis_block: Block = Block::genesis(network);

            let alice_cli = cli_args::Args::default();
            let (
                _alice_main_to_peer_tx,
                alice_main_to_peer_rx,
                alice_peer_to_main_tx,
                alice_peer_to_main_rx,
                alice,
                alice_hsd,
            ) = get_test_genesis_setup(network, 0, alice_cli).await.unwrap();

            let sync_challenge = SyncChallenge {
                tip_digest: genesis_block.hash(),
                challenges: [BlockHeight::genesis(); 10],
            };

            let alice_p2p_messages = Mock::new(vec![
                Action::Read(PeerMessage::SyncChallenge(sync_challenge)),
                Action::Read(PeerMessage::Bye),
            ]);

            let peer_address = get_dummy_socket_address(0);
            let mut alice_peer_loop_handler = PeerLoopHandler::new(
                alice_peer_to_main_tx.clone(),
                alice.clone(),
                peer_address,
                alice_hsd,
                false,
                1,
            );
            alice_peer_loop_handler
                .run_wrapper(alice_p2p_messages, alice_main_to_peer_rx)
                .await
                .unwrap();

            drop(alice_peer_to_main_rx);

            let latest_sanction = alice
                .lock_guard()
                .await
                .net
                .get_peer_standing_from_database(peer_address.ip())
                .await
                .unwrap();
            assert_eq!(
                NegativePeerSanction::InvalidSyncChallenge,
                latest_sanction
                    .latest_punishment
                    .expect("peer must be sanctioned")
                    .0
            );
        }

        #[traced_test]
        #[tokio::test]
        async fn sync_challenge_happy_path() -> Result<()> {
            // Bob notifies Alice of a block whose parameters satisfy the sync mode
            // criterion. Alice issues a challenge. Bob responds. Alice enters into
            // sync mode.

            let mut rng = rand::rng();
            let network = Network::Main;
            let genesis_block: Block = Block::genesis(network);

            const ALICE_SYNC_MODE_THRESHOLD: usize = 10;
            let alice_cli = cli_args::Args {
                sync_mode_threshold: ALICE_SYNC_MODE_THRESHOLD,
                ..Default::default()
            };
            let (
                _alice_main_to_peer_tx,
                alice_main_to_peer_rx,
                alice_peer_to_main_tx,
                mut alice_peer_to_main_rx,
                mut alice,
                alice_hsd,
            ) = get_test_genesis_setup(network, 0, alice_cli).await?;
            let _alice_socket_address = get_dummy_socket_address(0);

            let (
                _bob_main_to_peer_tx,
                _bob_main_to_peer_rx,
                _bob_peer_to_main_tx,
                _bob_peer_to_main_rx,
                mut bob,
                _bob_hsd,
            ) = get_test_genesis_setup(network, 0, cli_args::Args::default()).await?;
            let bob_socket_address = get_dummy_socket_address(0);

            let now = genesis_block.header().timestamp + Timestamp::hours(1);
            let block_1 = fake_valid_block_for_tests(&alice, rng.random()).await;
            assert!(
                block_1.is_valid(&genesis_block, now).await,
                "Block must be valid for this test to make sense"
            );
            let alice_tip = &block_1;
            alice.set_new_tip(block_1.clone()).await?;
            bob.set_new_tip(block_1.clone()).await?;

            // produce enough blocks to ensure alice needs to go into sync mode
            // with this block notification.
            let blocks = fake_valid_sequence_of_blocks_for_tests_dyn(
                &block_1,
                TARGET_BLOCK_INTERVAL,
                rng.random(),
                rng.random_range(ALICE_SYNC_MODE_THRESHOLD + 1..20),
            )
            .await;
            for block in &blocks {
                bob.set_new_tip(block.clone()).await?;
            }
            let bob_tip = blocks.last().unwrap();

            let block_notification_from_bob = PeerBlockNotification {
                hash: bob_tip.hash(),
                height: bob_tip.header().height,
                cumulative_proof_of_work: bob_tip.header().cumulative_proof_of_work,
            };

            let alice_rng_seed = rng.random::<[u8; 32]>();
            let mut alice_rng_clone = StdRng::from_seed(alice_rng_seed);
            let sync_challenge_from_alice = SyncChallenge::generate(
                &block_notification_from_bob,
                alice_tip.header().height,
                alice_rng_clone.random(),
            );

            println!(
                "sync challenge from alice:\n{:?}",
                sync_challenge_from_alice
            );

            let sync_challenge_response_from_bob = bob
                .lock_guard()
                .await
                .response_to_sync_challenge(sync_challenge_from_alice)
                .await
                .expect("should be able to respond to sync challenge");

            let alice_p2p_messages = Mock::new(vec![
                Action::Read(PeerMessage::BlockNotification(block_notification_from_bob)),
                Action::Write(PeerMessage::SyncChallenge(sync_challenge_from_alice)),
                Action::Read(PeerMessage::SyncChallengeResponse(Box::new(
                    sync_challenge_response_from_bob,
                ))),
                Action::Read(PeerMessage::BlockNotification(block_notification_from_bob)),
                // Ensure no 2nd sync challenge is sent, as timeout has not yet passed.
                // The absence of a Write here checks that a 2nd challenge isn't sent
                // when a successful was just received.
                Action::Read(PeerMessage::Bye),
            ]);

            let mut alice_peer_loop_handler = PeerLoopHandler::with_mocked_time(
                alice_peer_to_main_tx.clone(),
                alice.clone(),
                bob_socket_address,
                alice_hsd,
                false,
                1,
                bob_tip.header().timestamp,
            );
            alice_peer_loop_handler.set_rng(StdRng::from_seed(alice_rng_seed));
            alice_peer_loop_handler
                .run_wrapper(alice_p2p_messages, alice_main_to_peer_rx)
                .await?;

            // AddPeerMaxBlockHeight message triggered *after* sync challenge
            let mut expected_anchor_mmra = bob_tip.body().block_mmr_accumulator.clone();
            expected_anchor_mmra.append(bob_tip.hash());
            let expected_message_from_alice_peer_loop = PeerTaskToMain::AddPeerMaxBlockHeight {
                peer_address: bob_socket_address,
                claimed_height: bob_tip.header().height,
                claimed_cumulative_pow: bob_tip.header().cumulative_proof_of_work,
                claimed_block_mmra: expected_anchor_mmra,
            };
            let observed_message_from_alice_peer_loop = alice_peer_to_main_rx.recv().await.unwrap();
            assert_eq!(
                expected_message_from_alice_peer_loop,
                observed_message_from_alice_peer_loop
            );

            Ok(())
        }
    }
}

Neptune-Crypto / neptune-core / 14119571714

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