hopr_transport/

lib.rs

//! The crate aggregates and composes individual transport level objects and functionality
//! into a unified [`crate::HoprTransport`] object with the goal of isolating the transport layer
//! and defining a fully specified transport API.
//!
//! It also implements the Session negotiation via Start sub-protocol.
//! See the [`hopr_transport_session::initiation`] module for details on Start sub-protocol.
//!
//! As such, the transport layer components should be only those that are directly necessary to:
//!
//! 1. send and receive a packet, acknowledgement or ticket aggregation request
//! 2. send and receive a network telemetry request
//! 3. automate transport level processes
//! 4. algorithms associated with the transport layer operational management
//! 5. interface specifications to allow modular behavioral extensions

/// Configuration of the [crate::HoprTransport].
pub mod config;
/// Constants used and exposed by the crate.
pub mod constants;
/// Errors used by the crate.
pub mod errors;
pub mod helpers;
pub mod network_notifier;
/// Objects used and possibly exported by the crate for re-use for transport functionality
pub mod proxy;

use std::{
    collections::{HashMap, HashSet},
    sync::{Arc, OnceLock},
};

use async_lock::RwLock;
use constants::MAXIMUM_MSG_OUTGOING_BUFFER_SIZE;
use futures::{
    SinkExt, StreamExt,
    channel::mpsc::{self, Sender, UnboundedReceiver, UnboundedSender, unbounded},
};
use helpers::PathPlanner;
use hopr_async_runtime::{AbortHandle, spawn_as_abortable};
use hopr_crypto_packet::prelude::HoprPacket;
pub use hopr_crypto_types::{
    keypairs::{ChainKeypair, Keypair, OffchainKeypair},
    types::{HalfKeyChallenge, Hash, OffchainPublicKey},
};
use hopr_db_sql::{
    HoprDbAllOperations,
    accounts::ChainOrPacketKey,
    api::tickets::{AggregationPrerequisites, HoprDbTicketOperations},
};
pub use hopr_internal_types::prelude::HoprPseudonym;
use hopr_internal_types::prelude::*;
pub use hopr_network_types::prelude::RoutingOptions;
use hopr_network_types::prelude::{DestinationRouting, ResolvedTransportRouting};
use hopr_path::{
    PathAddressResolver,
    selectors::dfs::{DfsPathSelector, DfsPathSelectorConfig, RandomizedEdgeWeighting},
};
use hopr_primitive_types::prelude::*;
use hopr_transport_identity::multiaddrs::strip_p2p_protocol;
pub use hopr_transport_identity::{Multiaddr, PeerId};
use hopr_transport_mixer::MixerConfig;
pub use hopr_transport_network::network::{Health, Network, PeerOrigin, PeerStatus};
use hopr_transport_p2p::{
    HoprSwarm,
    swarm::{TicketAggregationRequestType, TicketAggregationResponseType},
};
pub use hopr_transport_packet::prelude::{ApplicationData, Tag};
use hopr_transport_probe::{
    DbProxy, Probe,
    ping::{PingConfig, Pinger},
};
pub use hopr_transport_probe::{errors::ProbeError, ping::PingQueryReplier};
pub use hopr_transport_protocol::{PeerDiscovery, execute_on_tick};
use hopr_transport_protocol::{
    errors::ProtocolError,
    processor::{MsgSender, PacketInteractionConfig, PacketSendFinalizer, SendMsgInput},
};
#[cfg(feature = "runtime-tokio")]
pub use hopr_transport_session::transfer_session;
pub use hopr_transport_session::{
    Capabilities as SessionCapabilities, Capability as SessionCapability, IncomingSession, SESSION_PAYLOAD_SIZE,
    ServiceId, Session, SessionClientConfig, SessionId, SessionTarget, SurbBalancerConfig,
    errors::TransportSessionError, traits::SendMsg,
};
use hopr_transport_session::{DispatchResult, SessionManager, SessionManagerConfig};
use hopr_transport_ticket_aggregation::{
    AwaitingAggregator, TicketAggregationActions, TicketAggregationError, TicketAggregationInteraction,
    TicketAggregatorTrait,
};
use rand::seq::SliceRandom;
#[cfg(feature = "mixer-stream")]
use rust_stream_ext_concurrent::then_concurrent::StreamThenConcurrentExt;
use tracing::{debug, error, info, trace, warn};

pub use crate::{
    config::HoprTransportConfig,
    helpers::{PeerEligibility, TicketStatistics},
};
use crate::{constants::SESSION_INITIATION_TIMEOUT_BASE, errors::HoprTransportError};

pub const APPLICATION_TAG_RANGE: std::ops::Range<Tag> = Tag::APPLICATION_TAG_RANGE;

#[cfg(any(
    all(feature = "mixer-channel", feature = "mixer-stream"),
    all(not(feature = "mixer-channel"), not(feature = "mixer-stream"))
))]
compile_error!("Exactly one of the 'mixer-channel' or 'mixer-stream' features must be specified");

// Needs lazy-static, since Duration multiplication by a constant is yet not a const-operation.
lazy_static::lazy_static! {
    static ref SESSION_INITIATION_TIMEOUT_MAX: std::time::Duration = 2 * constants::SESSION_INITIATION_TIMEOUT_BASE * RoutingOptions::MAX_INTERMEDIATE_HOPS as u32;
}

#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, strum::Display)]
pub enum HoprTransportProcess {
    #[strum(to_string = "component responsible for the transport medium (libp2p swarm)")]
    Medium,
    #[strum(to_string = "HOPR protocol ({0})")]
    Protocol(hopr_transport_protocol::ProtocolProcesses),
    #[strum(to_string = "session manager sub-process #{0}")]
    SessionsManagement(usize),
    #[strum(to_string = "network probing sub-process: {0}")]
    Probing(hopr_transport_probe::HoprProbeProcess),
}

#[derive(Debug, Clone)]
pub struct TicketAggregatorProxy<Db>
where
    Db: HoprDbTicketOperations + Send + Sync + Clone + std::fmt::Debug,
{
    db: Db,
    maybe_writer: Arc<OnceLock<TicketAggregationActions<TicketAggregationResponseType, TicketAggregationRequestType>>>,
    agg_timeout: std::time::Duration,
}

impl<Db> TicketAggregatorProxy<Db>
where
    Db: HoprDbTicketOperations + Send + Sync + Clone + std::fmt::Debug,
{
    pub fn new(
        db: Db,
        maybe_writer: Arc<
            OnceLock<TicketAggregationActions<TicketAggregationResponseType, TicketAggregationRequestType>>,
        >,
        agg_timeout: std::time::Duration,
    ) -> Self {
        Self {
            db,
            maybe_writer,
            agg_timeout,
        }
    }
}

#[async_trait::async_trait]
impl<Db> TicketAggregatorTrait for TicketAggregatorProxy<Db>
where
    Db: HoprDbTicketOperations + Send + Sync + Clone + std::fmt::Debug,
{
    async fn aggregate_tickets(
        &self,
        channel: &Hash,
        prerequisites: AggregationPrerequisites,
    ) -> hopr_transport_ticket_aggregation::Result<()> {
        if let Some(writer) = self.maybe_writer.clone().get() {
            AwaitingAggregator::new(self.db.clone(), writer.clone(), self.agg_timeout)
                .aggregate_tickets(channel, prerequisites)
                .await
        } else {
            Err(TicketAggregationError::TransportError(
                "Ticket aggregation writer not available, the object was not yet initialized".to_string(),
            ))
        }
    }
}

/// Currently used implementation of [`PathSelector`](hopr_path::selectors::PathSelector).
type CurrentPathSelector = DfsPathSelector<RandomizedEdgeWeighting>;

/// Interface into the physical transport mechanism allowing all off-chain HOPR-related tasks on
/// the transport, as well as off-chain ticket manipulation.
pub struct HoprTransport<T>
where
    T: HoprDbAllOperations + PathAddressResolver + std::fmt::Debug + Clone + Send + Sync + 'static,
{
    me: OffchainKeypair,
    me_peerid: PeerId, // Cache to avoid an expensive conversion: OffchainPublicKey -> PeerId
    me_address: Address,
    cfg: HoprTransportConfig,
    db: T,
    ping: Arc<OnceLock<Pinger>>,
    network: Arc<Network<T>>,
    process_packet_send: Arc<OnceLock<MsgSender<Sender<SendMsgInput>>>>,
    path_planner: PathPlanner<T, CurrentPathSelector>,
    my_multiaddresses: Vec<Multiaddr>,
    process_ticket_aggregate:
        Arc<OnceLock<TicketAggregationActions<TicketAggregationResponseType, TicketAggregationRequestType>>>,
    smgr: SessionManager<helpers::MessageSender<T, CurrentPathSelector>>,
}

impl<T> HoprTransport<T>
where
    T: HoprDbAllOperations + PathAddressResolver + std::fmt::Debug + Clone + Send + Sync + 'static,
{
    pub fn new(
        me: &OffchainKeypair,
        me_onchain: &ChainKeypair,
        cfg: HoprTransportConfig,
        db: T,
        channel_graph: Arc<RwLock<hopr_path::channel_graph::ChannelGraph>>,
        my_multiaddresses: Vec<Multiaddr>,
    ) -> Self {
        let process_packet_send = Arc::new(OnceLock::new());

        let me_peerid: PeerId = me.into();
        let me_chain_addr = me_onchain.public().to_address();

        Self {
            me: me.clone(),
            me_peerid,
            me_address: me_chain_addr,
            ping: Arc::new(OnceLock::new()),
            network: Arc::new(Network::new(
                me_peerid,
                my_multiaddresses.clone(),
                cfg.network.clone(),
                db.clone(),
            )),
            process_packet_send,
            path_planner: PathPlanner::new(
                me_chain_addr,
                db.clone(),
                CurrentPathSelector::new(
                    channel_graph.clone(),
                    DfsPathSelectorConfig {
                        node_score_threshold: cfg.network.node_score_auto_path_threshold,
                        max_first_hop_latency: cfg.network.max_first_hop_latency_threshold,
                        ..Default::default()
                    },
                ),
                channel_graph.clone(),
            ),
            db,
            my_multiaddresses,
            process_ticket_aggregate: Arc::new(OnceLock::new()),
            smgr: SessionManager::new(SessionManagerConfig {
                // TODO(v3.1): Use the entire range of tags properly
                session_tag_range: (16..65535),
                initiation_timeout_base: SESSION_INITIATION_TIMEOUT_BASE,
                idle_timeout: cfg.session.idle_timeout,
                balancer_sampling_interval: cfg.session.balancer_sampling_interval,
            }),
            cfg,
        }
    }

    /// Execute all processes of the [`crate::HoprTransport`] object.
    ///
    /// This method will spawn the [`crate::HoprTransportProcess::Heartbeat`],
    /// [`crate::HoprTransportProcess::BloomFilterSave`], [`crate::HoprTransportProcess::Swarm`] and session-related
    /// processes and return join handles to the calling function. These processes are not started immediately but
    /// are waiting for a trigger from this piece of code.
    #[allow(clippy::too_many_arguments)]
    pub async fn run(
        &self,
        me_onchain: &ChainKeypair,
        tbf_path: String,
        on_incoming_data: UnboundedSender<ApplicationData>,
        discovery_updates: UnboundedReceiver<PeerDiscovery>,
        on_incoming_session: UnboundedSender<IncomingSession>,
    ) -> crate::errors::Result<HashMap<HoprTransportProcess, AbortHandle>> {
        let (mut internal_discovery_update_tx, internal_discovery_update_rx) =
            futures::channel::mpsc::unbounded::<PeerDiscovery>();

        let network_clone = self.network.clone();
        let db_clone = self.db.clone();
        let me_peerid = self.me_peerid;
        let discovery_updates =
            futures_concurrency::stream::StreamExt::merge(discovery_updates, internal_discovery_update_rx)
                .filter_map(move |event| {
                    let network = network_clone.clone();
                    let db = db_clone.clone();
                    let me = me_peerid;

                    async move {
                        match event {
                            PeerDiscovery::Allow(peer_id) => {
                                debug!(peer = %peer_id, "Processing peer discovery event: Allow");
                                if let Ok(pk) = OffchainPublicKey::try_from(peer_id) {
                                    if !network.has(&peer_id).await {
                                        let mas = db
                                            .get_account(None, hopr_db_sql::accounts::ChainOrPacketKey::PacketKey(pk))
                                            .await
                                            .map(|entry| {
                                                entry
                                                    .map(|v| Vec::from_iter(v.get_multiaddr().into_iter()))
                                                    .unwrap_or_default()
                                            })
                                            .unwrap_or_default();

                                        if let Err(e) = network.add(&peer_id, PeerOrigin::NetworkRegistry, mas).await {
                                            error!(peer = %peer_id, error = %e, "Failed to allow locally (already allowed on-chain)");
                                            return None;
                                        }
                                    }

                                    return Some(PeerDiscovery::Allow(peer_id))
                                } else {
                                    error!(peer = %peer_id, "Failed to allow locally (already allowed on-chain): peer id not convertible to off-chain public key")
                                }
                            }
                            PeerDiscovery::Ban(peer_id) => {
                                if let Err(e) = network.remove(&peer_id).await {
                                    error!(peer = %peer_id, error = %e, "Failed to ban locally (already banned on-chain)")
                                } else {
                                    return Some(PeerDiscovery::Ban(peer_id))
                                }
                            }
                            PeerDiscovery::Announce(peer, multiaddresses) => {
                                debug!(peer = %peer, ?multiaddresses, "Processing peer discovery event: Announce");
                                if peer != me {
                                    // decapsulate the `p2p/<peer_id>` to remove duplicities
                                    let mas = multiaddresses
                                        .into_iter()
                                        .map(|ma| strip_p2p_protocol(&ma))
                                        .filter(|v| !v.is_empty())
                                        .collect::<Vec<_>>();

                                    if ! mas.is_empty() {
                                        if let Ok(pk) = OffchainPublicKey::try_from(peer) {
                                            if let Ok(Some(key)) = db.translate_key(None, hopr_db_sql::accounts::ChainOrPacketKey::PacketKey(pk)).await {
                                                let key: Result<Address, _> = key.try_into();

                                                if let Ok(key) = key {
                                                    if db
                                                        .is_allowed_in_network_registry(None, &key)
                                                        .await
                                                        .unwrap_or(false)
                                                    {
                                                        if let Err(e) = network.add(&peer, PeerOrigin::NetworkRegistry, mas.clone()).await
                                                        {
                                                            error!(%peer, error = %e, "failed to record peer from the NetworkRegistry");
                                                        } else {
                                                            return Some(PeerDiscovery::Announce(peer, mas))
                                                        }
                                                    }
                                                }
                                            } else {
                                                error!(%peer, "Failed to announce peer due to convertibility error");
                                            }
                                        }
                                    }
                                }
                            }
                        }

                        None
                    }
                });

        info!("Loading initial peers from the storage");

        let mut addresses: HashSet<Multiaddr> = HashSet::new();
        let nodes = self.get_public_nodes().await?;
        for (peer, _address, multiaddresses) in nodes {
            if self.is_allowed_to_access_network(either::Left(&peer)).await? {
                debug!(%peer, ?multiaddresses, "Using initial public node");
                addresses.extend(multiaddresses.clone());

                internal_discovery_update_tx
                    .send(PeerDiscovery::Announce(peer, multiaddresses.clone()))
                    .await
                    .map_err(|e| HoprTransportError::Api(e.to_string()))?;

                internal_discovery_update_tx
                    .send(PeerDiscovery::Allow(peer))
                    .await
                    .map_err(|e| HoprTransportError::Api(e.to_string()))?;
            }
        }

        let mut processes: HashMap<HoprTransportProcess, AbortHandle> = HashMap::new();

        let ticket_agg_proc = TicketAggregationInteraction::new(self.db.clone(), me_onchain);
        let tkt_agg_writer = ticket_agg_proc.writer();

        let (external_msg_send, external_msg_rx) =
            mpsc::channel::<(ApplicationData, ResolvedTransportRouting, PacketSendFinalizer)>(
                MAXIMUM_MSG_OUTGOING_BUFFER_SIZE,
            );

        self.process_packet_send
            .clone()
            .set(MsgSender::new(external_msg_send.clone()))
            .expect("must set the packet processing writer only once");

        self.process_ticket_aggregate
            .clone()
            .set(tkt_agg_writer.clone())
            .expect("must set the ticket aggregation writer only once");

        // -- transport medium
        let mixer_cfg = build_mixer_cfg_from_env();

        #[cfg(feature = "mixer-channel")]
        let (mixing_channel_tx, mixing_channel_rx) = hopr_transport_mixer::channel::<(PeerId, Box<[u8]>)>(mixer_cfg);

        #[cfg(feature = "mixer-stream")]
        let (mixing_channel_tx, mixing_channel_rx) = {
            let (tx, rx) = futures::channel::mpsc::channel::<(PeerId, Box<[u8]>)>(MAXIMUM_MSG_OUTGOING_BUFFER_SIZE);
            let rx = rx.then_concurrent(move |v| {
                let cfg = mixer_cfg;

                async move {
                    let random_delay = cfg.random_delay();
                    trace!(delay_in_ms = random_delay.as_millis(), "Created random mixer delay",);

                    #[cfg(all(feature = "prometheus", not(test)))]
                    hopr_transport_mixer::channel::METRIC_QUEUE_SIZE.decrement(1.0f64);

                    sleep(random_delay).await;

                    #[cfg(all(feature = "prometheus", not(test)))]
                    {
                        hopr_transport_mixer::channel::METRIC_QUEUE_SIZE.decrement(1.0f64);

                        let weight = 1.0f64 / cfg.metric_delay_window as f64;
                        hopr_transport_mixer::channel::METRIC_MIXER_AVERAGE_DELAY.set(
                            (weight * random_delay.as_millis() as f64)
                                + ((1.0f64 - weight) * hopr_transport_mixer::channel::METRIC_MIXER_AVERAGE_DELAY.get()),
                        );
                    }

                    v
                }
            });

            (tx, rx)
        };

        let mut transport_layer =
            HoprSwarm::new((&self.me).into(), discovery_updates, self.my_multiaddresses.clone()).await;

        if let Some(port) = self.cfg.protocol.autonat_port {
            transport_layer.run_nat_server(port);
        }

        if addresses.is_empty() {
            warn!("No addresses found in the database, not dialing any NAT servers");
        } else {
            info!(num_addresses = addresses.len(), "Found addresses from the database");
            let mut randomized_addresses: Vec<_> = addresses.into_iter().collect();
            randomized_addresses.shuffle(&mut rand::thread_rng());
            transport_layer.dial_nat_server(randomized_addresses);
        }

        let msg_proto_control =
            transport_layer.build_protocol_control(hopr_transport_protocol::CURRENT_HOPR_MSG_PROTOCOL);
        let msg_codec = hopr_transport_protocol::HoprBinaryCodec {};
        let (wire_msg_tx, wire_msg_rx) =
            hopr_transport_protocol::stream::process_stream_protocol(msg_codec, msg_proto_control).await?;

        let _mixing_process_before_sending_out =
            hopr_async_runtime::prelude::spawn(mixing_channel_rx.map(Ok).forward(wire_msg_tx));

        processes.insert(HoprTransportProcess::Medium, spawn_as_abortable(transport_layer.run()));

        // -- msg-ack protocol over the wire transport
        let packet_cfg = PacketInteractionConfig {
            packet_keypair: self.me.clone(),
            outgoing_ticket_win_prob: self
                .cfg
                .protocol
                .outgoing_ticket_winning_prob
                .map(WinningProbability::try_from)
                .transpose()?,
            outgoing_ticket_price: self.cfg.protocol.outgoing_ticket_price,
        };

        let (tx_from_protocol, rx_from_protocol) = unbounded::<(HoprPseudonym, ApplicationData)>();
        for (k, v) in hopr_transport_protocol::run_msg_ack_protocol(
            packet_cfg,
            self.db.clone(),
            Some(tbf_path),
            (mixing_channel_tx, wire_msg_rx),
            (tx_from_protocol, external_msg_rx),
        )
        .await
        .into_iter()
        {
            processes.insert(HoprTransportProcess::Protocol(k), v);
        }

        // -- network probing
        let (tx_from_probing, rx_from_probing) = unbounded::<(HoprPseudonym, ApplicationData)>();

        let (manual_ping_tx, manual_ping_rx) = unbounded::<(PeerId, PingQueryReplier)>();

        let probe = Probe::new((*self.me.public(), self.me_address), self.cfg.probe);
        for (k, v) in probe
            .continuously_scan(
                (external_msg_send, rx_from_protocol),
                manual_ping_rx,
                network_notifier::ProbeNetworkInteractions::new(
                    self.network.clone(),
                    self.db.clone(),
                    self.path_planner.channel_graph(),
                ),
                DbProxy::new(self.db.clone()),
                tx_from_probing,
            )
            .await
            .into_iter()
        {
            processes.insert(HoprTransportProcess::Probing(k), v);
        }

        // manual ping
        self.ping
            .clone()
            .set(Pinger::new(
                PingConfig {
                    timeout: self.cfg.probe.timeout,
                },
                manual_ping_tx,
            ))
            .expect("must set the ticket aggregation writer only once");

        // -- session management
        let msg_sender = helpers::MessageSender::new(self.process_packet_send.clone(), self.path_planner.clone());
        self.smgr
            .start(msg_sender, on_incoming_session)
            .expect("failed to start session manager")
            .into_iter()
            .enumerate()
            .map(|(i, jh)| (HoprTransportProcess::SessionsManagement(i + 1), jh))
            .for_each(|(k, v)| {
                processes.insert(k, v);
            });

        let smgr = self.smgr.clone();
        processes.insert(
            HoprTransportProcess::SessionsManagement(0),
            spawn_as_abortable(async move {
                let _the_process_should_not_end = StreamExt::filter_map(rx_from_probing, |(pseudonym, data)| {
                    let smgr = smgr.clone();
                    async move {
                        match smgr.dispatch_message(pseudonym, data).await {
                            Ok(DispatchResult::Processed) => {
                                trace!("message dispatch completed");
                                None
                            }
                            Ok(DispatchResult::Unrelated(data)) => {
                                trace!("unrelated message dispatch completed");
                                Some(data)
                            }
                            Err(e) => {
                                error!(error = %e, "error while processing packet");
                                None
                            }
                        }
                    }
                })
                .map(Ok)
                .forward(on_incoming_data)
                .await;
            }),
        );

        Ok(processes)
    }

    pub fn ticket_aggregator(&self) -> Arc<dyn TicketAggregatorTrait + Send + Sync + 'static> {
        Arc::new(proxy::TicketAggregatorProxy::new(
            self.db.clone(),
            self.process_ticket_aggregate.clone(),
            std::time::Duration::from_secs(15),
        ))
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn ping(&self, peer: &PeerId) -> errors::Result<(std::time::Duration, PeerStatus)> {
        if !self.is_allowed_to_access_network(either::Left(peer)).await? {
            return Err(HoprTransportError::Api(format!(
                "ping to '{peer}' not allowed due to network registry"
            )));
        }

        if peer == &self.me_peerid {
            return Err(HoprTransportError::Api("ping to self does not make sense".into()));
        }

        let pinger = self
            .ping
            .get()
            .ok_or_else(|| HoprTransportError::Api("ping processing is not yet initialized".into()))?;

        if let Err(e) = self.network.add(peer, PeerOrigin::ManualPing, vec![]).await {
            error!(error = %e, "Failed to store the peer observation");
        }

        let latency = (*pinger).ping(*peer).await?;

        let peer_status = self.network.get(peer).await?.ok_or(HoprTransportError::Probe(
            hopr_transport_probe::errors::ProbeError::NonExistingPeer,
        ))?;

        Ok((latency, peer_status))
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn new_session(
        &self,
        destination: Address,
        target: SessionTarget,
        cfg: SessionClientConfig,
    ) -> errors::Result<Session> {
        Ok(self.smgr.new_session(destination, target, cfg).await?)
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn probe_session(&self, id: &SessionId) -> errors::Result<()> {
        Ok(self.smgr.ping_session(id).await?)
    }

    #[tracing::instrument(level = "info", skip(self, msg), fields(uuid = uuid::Uuid::new_v4().to_string()))]
    pub async fn send_message(&self, msg: Box<[u8]>, routing: DestinationRouting, tag: Tag) -> errors::Result<()> {
        if let Tag::Reserved(reserved_tag) = tag {
            return Err(HoprTransportError::Api(format!(
                "Application tag must not from range: {:?}, but was {reserved_tag:?}",
                Tag::APPLICATION_TAG_RANGE
            )));
        }

        if msg.len() > HoprPacket::PAYLOAD_SIZE {
            return Err(HoprTransportError::Api(format!(
                "Message exceeds the maximum allowed size of {} bytes",
                HoprPacket::PAYLOAD_SIZE
            )));
        }

        let app_data = ApplicationData::new_from_owned(tag, msg);
        let routing = self.path_planner.resolve_routing(app_data.len(), routing).await?;

        // Here we do not use msg_sender directly,
        // since it internally follows Session-oriented logic
        let sender = self.process_packet_send.get().ok_or_else(|| {
            HoprTransportError::Api("send msg: failed because message processing is not yet initialized".into())
        })?;

        sender
            .send_packet(app_data, routing)
            .await
            .map_err(|e| HoprTransportError::Api(format!("send msg failed to enqueue msg: {e}")))?
            .consume_and_wait(crate::constants::PACKET_QUEUE_TIMEOUT_MILLISECONDS)
            .await
            .map_err(|e| HoprTransportError::Api(e.to_string()))
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn aggregate_tickets(&self, channel_id: &Hash) -> errors::Result<()> {
        let entry = self
            .db
            .get_channel_by_id(None, channel_id)
            .await
            .map_err(hopr_db_sql::api::errors::DbError::from)
            .map_err(HoprTransportError::from)
            .and_then(|c| {
                if let Some(c) = c {
                    Ok(c)
                } else {
                    Err(ProtocolError::ChannelNotFound.into())
                }
            })?;

        if entry.status != ChannelStatus::Open {
            return Err(ProtocolError::ChannelClosed.into());
        }

        // Ok(Arc::new(proxy::TicketAggregatorProxy::new(
        //     self.db.clone(),
        //     self.process_ticket_aggregate.clone(),
        //     std::time::Duration::from_secs(15),
        // ))
        // .aggregate_tickets(&entry.get_id(), Default::default())
        // .await?)

        Err(TicketAggregationError::TransportError(
            "Ticket aggregation not supported as a session protocol yet".to_string(),
        )
        .into())
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn get_public_nodes(&self) -> errors::Result<Vec<(PeerId, Address, Vec<Multiaddr>)>> {
        Ok(self
            .db
            .get_accounts(None, true)
            .await
            .map_err(hopr_db_sql::api::errors::DbError::from)?
            .into_iter()
            .map(|entry| {
                (
                    PeerId::from(entry.public_key),
                    entry.chain_addr,
                    Vec::from_iter(entry.get_multiaddr().into_iter()),
                )
            })
            .collect())
    }

    pub async fn is_allowed_to_access_network<'a>(
        &self,
        address_like: either::Either<&'a PeerId, Address>,
    ) -> errors::Result<bool>
    where
        T: 'a,
    {
        let db_clone = self.db.clone();
        let address_like_noref = address_like.map_left(|peer| *peer);

        Ok(self
            .db
            .begin_transaction()
            .await
            .map_err(hopr_db_sql::api::errors::DbError::from)?
            .perform(|tx| {
                Box::pin(async move {
                    match address_like_noref {
                        either::Left(peer) => {
                            let pk = OffchainPublicKey::try_from(peer)?;
                            if let Some(address) = db_clone.translate_key(Some(tx), pk).await? {
                                db_clone.is_allowed_in_network_registry(Some(tx), &address).await
                            } else {
                                Err(hopr_db_sql::errors::DbSqlError::LogicalError(
                                    "cannot translate off-chain key".into(),
                                ))
                            }
                        }
                        either::Right(address) => db_clone.is_allowed_in_network_registry(Some(tx), &address).await,
                    }
                })
            })
            .await
            .map_err(hopr_db_sql::api::errors::DbError::from)?)
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn listening_multiaddresses(&self) -> Vec<Multiaddr> {
        self.network
            .get(&self.me_peerid)
            .await
            .unwrap_or_else(|e| {
                error!(error = %e, "failed to obtain listening multi-addresses");
                None
            })
            .map(|peer| peer.multiaddresses)
            .unwrap_or_default()
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub fn announceable_multiaddresses(&self) -> Vec<Multiaddr> {
        let mut mas = self
            .local_multiaddresses()
            .into_iter()
            .filter(|ma| {
                hopr_transport_identity::multiaddrs::is_supported(ma)
                    && (self.cfg.transport.announce_local_addresses
                        || !hopr_transport_identity::multiaddrs::is_private(ma))
            })
            .map(|ma| strip_p2p_protocol(&ma))
            .filter(|v| !v.is_empty())
            .collect::<Vec<_>>();

        mas.sort_by(|l, r| {
            let is_left_dns = hopr_transport_identity::multiaddrs::is_dns(l);
            let is_right_dns = hopr_transport_identity::multiaddrs::is_dns(r);

            if !(is_left_dns ^ is_right_dns) {
                std::cmp::Ordering::Equal
            } else if is_left_dns {
                std::cmp::Ordering::Less
            } else {
                std::cmp::Ordering::Greater
            }
        });

        mas
    }

    pub fn local_multiaddresses(&self) -> Vec<Multiaddr> {
        self.my_multiaddresses.clone()
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn network_observed_multiaddresses(&self, peer: &PeerId) -> Vec<Multiaddr> {
        self.network
            .get(peer)
            .await
            .unwrap_or(None)
            .map(|peer| peer.multiaddresses)
            .unwrap_or(vec![])
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn network_health(&self) -> Health {
        self.network.health().await
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn network_connected_peers(&self) -> errors::Result<Vec<PeerId>> {
        Ok(self.network.connected_peers().await?)
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn network_peer_info(&self, peer: &PeerId) -> errors::Result<Option<PeerStatus>> {
        Ok(self.network.get(peer).await?)
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn ticket_statistics(&self) -> errors::Result<TicketStatistics> {
        let ticket_stats = self.db.get_ticket_statistics(None).await?;

        Ok(TicketStatistics {
            winning_count: ticket_stats.winning_tickets,
            unredeemed_value: ticket_stats.unredeemed_value,
            redeemed_value: ticket_stats.redeemed_value,
            neglected_value: ticket_stats.neglected_value,
            rejected_value: ticket_stats.rejected_value,
        })
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn tickets_in_channel(&self, channel_id: &Hash) -> errors::Result<Option<Vec<AcknowledgedTicket>>> {
        if let Some(channel) = self
            .db
            .get_channel_by_id(None, channel_id)
            .await
            .map_err(hopr_db_sql::api::errors::DbError::from)?
        {
            let own_address: Address = self
                .db
                .translate_key(None, ChainOrPacketKey::PacketKey(*self.me.public()))
                .await?
                .ok_or_else(|| {
                    HoprTransportError::Api("Failed to translate the off-chain key to on-chain address".into())
                })?
                .try_into()?;

            if channel.destination == own_address {
                Ok(Some(self.db.get_tickets((&channel).into()).await?))
            } else {
                Ok(None)
            }
        } else {
            Ok(None)
        }
    }

    #[tracing::instrument(level = "debug", skip(self))]
    pub async fn all_tickets(&self) -> errors::Result<Vec<Ticket>> {
        Ok(self
            .db
            .get_all_tickets()
            .await?
            .into_iter()
            .map(|v| v.ticket.leak())
            .collect())
    }
}

fn build_mixer_cfg_from_env() -> MixerConfig {
    let mixer_cfg = MixerConfig {
        min_delay: std::time::Duration::from_millis(
            std::env::var("HOPR_INTERNAL_MIXER_MINIMUM_DELAY_IN_MS")
                .map(|v| {
                    v.trim()
                        .parse::<u64>()
                        .unwrap_or(hopr_transport_mixer::config::HOPR_MIXER_MINIMUM_DEFAULT_DELAY_IN_MS)
                })
                .unwrap_or(hopr_transport_mixer::config::HOPR_MIXER_MINIMUM_DEFAULT_DELAY_IN_MS),
        ),
        delay_range: std::time::Duration::from_millis(
            std::env::var("HOPR_INTERNAL_MIXER_DELAY_RANGE_IN_MS")
                .map(|v| {
                    v.trim()
                        .parse::<u64>()
                        .unwrap_or(hopr_transport_mixer::config::HOPR_MIXER_DEFAULT_DELAY_RANGE_IN_MS)
                })
                .unwrap_or(hopr_transport_mixer::config::HOPR_MIXER_DEFAULT_DELAY_RANGE_IN_MS),
        ),
        capacity: std::env::var("HOPR_INTERNAL_MIXER_CAPACITY")
            .map(|v| {
                v.trim()
                    .parse::<usize>()
                    .unwrap_or(hopr_transport_mixer::config::HOPR_MIXER_CAPACITY)
            })
            .unwrap_or(hopr_transport_mixer::config::HOPR_MIXER_CAPACITY),
        ..MixerConfig::default()
    };
    debug!(?mixer_cfg, "Mixer configuration");

    mixer_cfg
}