Network sync refactoring (part 6) (#11940)

* Extract `NetworkKVProvider` trait in `sc-authority-discovery` and remove unnecessary dependency * Extract `NetworkSyncForkRequest` trait in `sc-finality-grandpa` * Relax requirements on `SyncOracle` trait, remove extra native methods from `NetworkService` that are already provided by trait impls * Move `NetworkSigner` trait from `sc-authority-discovery` into `sc-network-common` and de-duplicate methods on `NetworkService` * Move `NetworkKVProvider` trait from `sc-authority-discovery` into `sc-network-common` and de-duplicate methods on `NetworkService` * Minimize `sc-authority-discovery` dependency on `sc-network` * Move `NetworkSyncForkRequest` trait from `sc-finality-grandpa` to `sc-network-common` and de-duplicate methods in `NetworkService` * Extract `NetworkStatusProvider` trait and de-duplicate methods on `NetworkService` * Extract `NetworkPeers` trait and de-duplicate methods on `NetworkService` * Extract `NetworkEventStream` trait and de-duplicate methods on `NetworkService` * Move more methods from `NetworkService` into `NetworkPeers` trait * Move `NetworkStateInfo` trait into `sc-network-common` * Extract `NetworkNotification` trait and de-duplicate methods on `NetworkService` * Extract `NetworkRequest` trait and de-duplicate methods on `NetworkService` * Remove `NetworkService::local_peer_id()`, it is already provided by `NetworkStateInfo` impl * Extract `NetworkTransaction` trait and de-duplicate methods on `NetworkService` * Extract `NetworkBlock` trait and de-duplicate methods on `NetworkService` * Remove dependencies on `NetworkService` from most of the methods of `sc-service` * Address simple review comments
2026-04-30 13:07:56 +00:00 · 2022-08-09 21:28:32 +03:00
parent 9c56e79c43
commit a685582bfd
49 changed files with 1889 additions and 1029 deletions
@@ -0,0 +1,660 @@
+// This file is part of Substrate.
+//
+// Copyright (C) 2017-2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+//
+// If you read this, you are very thorough, congratulations.
+
+use crate::{
+	protocol::event::Event,
+	request_responses::{IfDisconnected, RequestFailure},
+	sync::{warp::WarpSyncProgress, StateDownloadProgress, SyncState},
+};
+use futures::{channel::oneshot, Stream};
+pub use libp2p::{identity::error::SigningError, kad::record::Key as KademliaKey};
+use libp2p::{Multiaddr, PeerId};
+use sc_peerset::ReputationChange;
+pub use signature::Signature;
+use sp_runtime::traits::{Block as BlockT, NumberFor};
+use std::{borrow::Cow, collections::HashSet, future::Future, pin::Pin, sync::Arc};
+
+mod signature;
+
+/// Signer with network identity
+pub trait NetworkSigner {
+	/// Signs the message with the `KeyPair` that defines the local [`PeerId`].
+	fn sign_with_local_identity(&self, msg: impl AsRef<[u8]>) -> Result<Signature, SigningError>;
+}
+
+impl<T> NetworkSigner for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkSigner,
+{
+	fn sign_with_local_identity(&self, msg: impl AsRef<[u8]>) -> Result<Signature, SigningError> {
+		T::sign_with_local_identity(self, msg)
+	}
+}
+
+/// Provides access to the networking DHT.
+pub trait NetworkDHTProvider {
+	/// Start getting a value from the DHT.
+	fn get_value(&self, key: &KademliaKey);
+
+	/// Start putting a value in the DHT.
+	fn put_value(&self, key: KademliaKey, value: Vec<u8>);
+}
+
+impl<T> NetworkDHTProvider for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkDHTProvider,
+{
+	fn get_value(&self, key: &KademliaKey) {
+		T::get_value(self, key)
+	}
+
+	fn put_value(&self, key: KademliaKey, value: Vec<u8>) {
+		T::put_value(self, key, value)
+	}
+}
+
+/// Provides an ability to set a fork sync request for a particular block.
+pub trait NetworkSyncForkRequest<BlockHash, BlockNumber> {
+	/// Notifies the sync service to try and sync the given block from the given
+	/// peers.
+	///
+	/// If the given vector of peers is empty then the underlying implementation
+	/// should make a best effort to fetch the block from any peers it is
+	/// connected to (NOTE: this assumption will change in the future #3629).
+	fn set_sync_fork_request(&self, peers: Vec<PeerId>, hash: BlockHash, number: BlockNumber);
+}
+
+impl<T, BlockHash, BlockNumber> NetworkSyncForkRequest<BlockHash, BlockNumber> for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkSyncForkRequest<BlockHash, BlockNumber>,
+{
+	fn set_sync_fork_request(&self, peers: Vec<PeerId>, hash: BlockHash, number: BlockNumber) {
+		T::set_sync_fork_request(self, peers, hash, number)
+	}
+}
+
+/// Overview status of the network.
+#[derive(Clone)]
+pub struct NetworkStatus<B: BlockT> {
+	/// Current global sync state.
+	pub sync_state: SyncState,
+	/// Target sync block number.
+	pub best_seen_block: Option<NumberFor<B>>,
+	/// Number of peers participating in syncing.
+	pub num_sync_peers: u32,
+	/// Total number of connected peers
+	pub num_connected_peers: usize,
+	/// Total number of active peers.
+	pub num_active_peers: usize,
+	/// The total number of bytes received.
+	pub total_bytes_inbound: u64,
+	/// The total number of bytes sent.
+	pub total_bytes_outbound: u64,
+	/// State sync in progress.
+	pub state_sync: Option<StateDownloadProgress>,
+	/// Warp sync in progress.
+	pub warp_sync: Option<WarpSyncProgress<B>>,
+}
+
+/// Provides high-level status information about network.
+#[async_trait::async_trait]
+pub trait NetworkStatusProvider<Block: BlockT> {
+	/// High-level network status information.
+	///
+	/// Returns an error if the `NetworkWorker` is no longer running.
+	async fn status(&self) -> Result<NetworkStatus<Block>, ()>;
+}
+
+// Manual implementation to avoid extra boxing here
+impl<T, Block: BlockT> NetworkStatusProvider<Block> for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkStatusProvider<Block>,
+{
+	fn status<'life0, 'async_trait>(
+		&'life0 self,
+	) -> Pin<Box<dyn Future<Output = Result<NetworkStatus<Block>, ()>> + Send + 'async_trait>>
+	where
+		'life0: 'async_trait,
+		Self: 'async_trait,
+	{
+		T::status(self)
+	}
+}
+
+/// Provides low-level API for manipulating network peers.
+pub trait NetworkPeers {
+	/// Set authorized peers.
+	///
+	/// Need a better solution to manage authorized peers, but now just use reserved peers for
+	/// prototyping.
+	fn set_authorized_peers(&self, peers: HashSet<PeerId>);
+
+	/// Set authorized_only flag.
+	///
+	/// Need a better solution to decide authorized_only, but now just use reserved_only flag for
+	/// prototyping.
+	fn set_authorized_only(&self, reserved_only: bool);
+
+	/// Adds an address known to a node.
+	fn add_known_address(&self, peer_id: PeerId, addr: Multiaddr);
+
+	/// Report a given peer as either beneficial (+) or costly (-) according to the
+	/// given scalar.
+	fn report_peer(&self, who: PeerId, cost_benefit: ReputationChange);
+
+	/// Disconnect from a node as soon as possible.
+	///
+	/// This triggers the same effects as if the connection had closed itself spontaneously.
+	///
+	/// See also [`NetworkPeers::remove_from_peers_set`], which has the same effect but also
+	/// prevents the local node from re-establishing an outgoing substream to this peer until it
+	/// is added again.
+	fn disconnect_peer(&self, who: PeerId, protocol: Cow<'static, str>);
+
+	/// Connect to unreserved peers and allow unreserved peers to connect for syncing purposes.
+	fn accept_unreserved_peers(&self);
+
+	/// Disconnect from unreserved peers and deny new unreserved peers to connect for syncing
+	/// purposes.
+	fn deny_unreserved_peers(&self);
+
+	/// Adds a `PeerId` and its address as reserved. The string should encode the address
+	/// and peer ID of the remote node.
+	///
+	/// Returns an `Err` if the given string is not a valid multiaddress
+	/// or contains an invalid peer ID (which includes the local peer ID).
+	fn add_reserved_peer(&self, peer: String) -> Result<(), String>;
+
+	/// Removes a `PeerId` from the list of reserved peers.
+	fn remove_reserved_peer(&self, peer_id: PeerId);
+
+	/// Sets the reserved set of a protocol to the given set of peers.
+	///
+	/// Each `Multiaddr` must end with a `/p2p/` component containing the `PeerId`. It can also
+	/// consist of only `/p2p/<peerid>`.
+	///
+	/// The node will start establishing/accepting connections and substreams to/from peers in this
+	/// set, if it doesn't have any substream open with them yet.
+	///
+	/// Note however, if a call to this function results in less peers on the reserved set, they
+	/// will not necessarily get disconnected (depending on available free slots in the peer set).
+	/// If you want to also disconnect those removed peers, you will have to call
+	/// `remove_from_peers_set` on those in addition to updating the reserved set. You can omit
+	/// this step if the peer set is in reserved only mode.
+	///
+	/// Returns an `Err` if one of the given addresses is invalid or contains an
+	/// invalid peer ID (which includes the local peer ID).
+	fn set_reserved_peers(
+		&self,
+		protocol: Cow<'static, str>,
+		peers: HashSet<Multiaddr>,
+	) -> Result<(), String>;
+
+	/// Add peers to a peer set.
+	///
+	/// Each `Multiaddr` must end with a `/p2p/` component containing the `PeerId`. It can also
+	/// consist of only `/p2p/<peerid>`.
+	///
+	/// Returns an `Err` if one of the given addresses is invalid or contains an
+	/// invalid peer ID (which includes the local peer ID).
+	fn add_peers_to_reserved_set(
+		&self,
+		protocol: Cow<'static, str>,
+		peers: HashSet<Multiaddr>,
+	) -> Result<(), String>;
+
+	/// Remove peers from a peer set.
+	fn remove_peers_from_reserved_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>);
+
+	/// Add a peer to a set of peers.
+	///
+	/// If the set has slots available, it will try to open a substream with this peer.
+	///
+	/// Each `Multiaddr` must end with a `/p2p/` component containing the `PeerId`. It can also
+	/// consist of only `/p2p/<peerid>`.
+	///
+	/// Returns an `Err` if one of the given addresses is invalid or contains an
+	/// invalid peer ID (which includes the local peer ID).
+	fn add_to_peers_set(
+		&self,
+		protocol: Cow<'static, str>,
+		peers: HashSet<Multiaddr>,
+	) -> Result<(), String>;
+
+	/// Remove peers from a peer set.
+	///
+	/// If we currently have an open substream with this peer, it will soon be closed.
+	fn remove_from_peers_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>);
+
+	/// Returns the number of peers in the sync peer set we're connected to.
+	fn sync_num_connected(&self) -> usize;
+}
+
+// Manual implementation to avoid extra boxing here
+impl<T> NetworkPeers for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkPeers,
+{
+	fn set_authorized_peers(&self, peers: HashSet<PeerId>) {
+		T::set_authorized_peers(self, peers)
+	}
+
+	fn set_authorized_only(&self, reserved_only: bool) {
+		T::set_authorized_only(self, reserved_only)
+	}
+
+	fn add_known_address(&self, peer_id: PeerId, addr: Multiaddr) {
+		T::add_known_address(self, peer_id, addr)
+	}
+
+	fn report_peer(&self, who: PeerId, cost_benefit: ReputationChange) {
+		T::report_peer(self, who, cost_benefit)
+	}
+
+	fn disconnect_peer(&self, who: PeerId, protocol: Cow<'static, str>) {
+		T::disconnect_peer(self, who, protocol)
+	}
+
+	fn accept_unreserved_peers(&self) {
+		T::accept_unreserved_peers(self)
+	}
+
+	fn deny_unreserved_peers(&self) {
+		T::deny_unreserved_peers(self)
+	}
+
+	fn add_reserved_peer(&self, peer: String) -> Result<(), String> {
+		T::add_reserved_peer(self, peer)
+	}
+
+	fn remove_reserved_peer(&self, peer_id: PeerId) {
+		T::remove_reserved_peer(self, peer_id)
+	}
+
+	fn set_reserved_peers(
+		&self,
+		protocol: Cow<'static, str>,
+		peers: HashSet<Multiaddr>,
+	) -> Result<(), String> {
+		T::set_reserved_peers(self, protocol, peers)
+	}
+
+	fn add_peers_to_reserved_set(
+		&self,
+		protocol: Cow<'static, str>,
+		peers: HashSet<Multiaddr>,
+	) -> Result<(), String> {
+		T::add_peers_to_reserved_set(self, protocol, peers)
+	}
+
+	fn remove_peers_from_reserved_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>) {
+		T::remove_peers_from_reserved_set(self, protocol, peers)
+	}
+
+	fn add_to_peers_set(
+		&self,
+		protocol: Cow<'static, str>,
+		peers: HashSet<Multiaddr>,
+	) -> Result<(), String> {
+		T::add_to_peers_set(self, protocol, peers)
+	}
+
+	fn remove_from_peers_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>) {
+		T::remove_from_peers_set(self, protocol, peers)
+	}
+
+	fn sync_num_connected(&self) -> usize {
+		T::sync_num_connected(self)
+	}
+}
+
+/// Provides access to network-level event stream.
+pub trait NetworkEventStream {
+	/// Returns a stream containing the events that happen on the network.
+	///
+	/// If this method is called multiple times, the events are duplicated.
+	///
+	/// The stream never ends (unless the `NetworkWorker` gets shut down).
+	///
+	/// The name passed is used to identify the channel in the Prometheus metrics. Note that the
+	/// parameter is a `&'static str`, and not a `String`, in order to avoid accidentally having
+	/// an unbounded set of Prometheus metrics, which would be quite bad in terms of memory
+	fn event_stream(&self, name: &'static str) -> Pin<Box<dyn Stream<Item = Event> + Send>>;
+}
+
+impl<T> NetworkEventStream for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkEventStream,
+{
+	fn event_stream(&self, name: &'static str) -> Pin<Box<dyn Stream<Item = Event> + Send>> {
+		T::event_stream(self, name)
+	}
+}
+
+/// Trait for providing information about the local network state
+pub trait NetworkStateInfo {
+	/// Returns the local external addresses.
+	fn external_addresses(&self) -> Vec<Multiaddr>;
+
+	/// Returns the local Peer ID.
+	fn local_peer_id(&self) -> PeerId;
+}
+
+impl<T> NetworkStateInfo for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkStateInfo,
+{
+	fn external_addresses(&self) -> Vec<Multiaddr> {
+		T::external_addresses(self)
+	}
+
+	fn local_peer_id(&self) -> PeerId {
+		T::local_peer_id(self)
+	}
+}
+
+/// Reserved slot in the notifications buffer, ready to accept data.
+pub trait NotificationSenderReady {
+	/// Consumes this slots reservation and actually queues the notification.
+	///
+	/// NOTE: Traits can't consume itself, but calling this method second time will return an error.
+	fn send(&mut self, notification: Vec<u8>) -> Result<(), NotificationSenderError>;
+}
+
+/// A `NotificationSender` allows for sending notifications to a peer with a chosen protocol.
+#[async_trait::async_trait]
+pub trait NotificationSender {
+	/// Returns a future that resolves when the `NotificationSender` is ready to send a
+	/// notification.
+	async fn ready(&self)
+		-> Result<Box<dyn NotificationSenderReady + '_>, NotificationSenderError>;
+}
+
+/// Error returned by [`NetworkNotification::notification_sender`].
+#[derive(Debug, thiserror::Error)]
+pub enum NotificationSenderError {
+	/// The notification receiver has been closed, usually because the underlying connection
+	/// closed.
+	///
+	/// Some of the notifications most recently sent may not have been received. However,
+	/// the peer may still be connected and a new `NotificationSender` for the same
+	/// protocol obtained from [`NetworkNotification::notification_sender`].
+	#[error("The notification receiver has been closed")]
+	Closed,
+	/// Protocol name hasn't been registered.
+	#[error("Protocol name hasn't been registered")]
+	BadProtocol,
+}
+
+/// Provides ability to send network notifications.
+pub trait NetworkNotification {
+	/// Appends a notification to the buffer of pending outgoing notifications with the given peer.
+	/// Has no effect if the notifications channel with this protocol name is not open.
+	///
+	/// If the buffer of pending outgoing notifications with that peer is full, the notification
+	/// is silently dropped and the connection to the remote will start being shut down. This
+	/// happens if you call this method at a higher rate than the rate at which the peer processes
+	/// these notifications, or if the available network bandwidth is too low.
+	///
+	/// For this reason, this method is considered soft-deprecated. You are encouraged to use
+	/// [`NetworkNotification::notification_sender`] instead.
+	///
+	/// > **Note**: The reason why this is a no-op in the situation where we have no channel is
+	/// >			that we don't guarantee message delivery anyway. Networking issues can cause
+	/// >			connections to drop at any time, and higher-level logic shouldn't differentiate
+	/// >			between the remote voluntarily closing a substream or a network error
+	/// >			preventing the message from being delivered.
+	///
+	/// The protocol must have been registered with
+	/// `crate::config::NetworkConfiguration::notifications_protocols`.
+	fn write_notification(&self, target: PeerId, protocol: Cow<'static, str>, message: Vec<u8>);
+
+	/// Obtains a [`NotificationSender`] for a connected peer, if it exists.
+	///
+	/// A `NotificationSender` is scoped to a particular connection to the peer that holds
+	/// a receiver. With a `NotificationSender` at hand, sending a notification is done in two
+	/// steps:
+	///
+	/// 1.  [`NotificationSender::ready`] is used to wait for the sender to become ready
+	/// for another notification, yielding a [`NotificationSenderReady`] token.
+	/// 2.  [`NotificationSenderReady::send`] enqueues the notification for sending. This operation
+	/// can only fail if the underlying notification substream or connection has suddenly closed.
+	///
+	/// An error is returned by [`NotificationSenderReady::send`] if there exists no open
+	/// notifications substream with that combination of peer and protocol, or if the remote
+	/// has asked to close the notifications substream. If that happens, it is guaranteed that an
+	/// [`Event::NotificationStreamClosed`] has been generated on the stream returned by
+	/// [`NetworkEventStream::event_stream`].
+	///
+	/// If the remote requests to close the notifications substream, all notifications successfully
+	/// enqueued using [`NotificationSenderReady::send`] will finish being sent out before the
+	/// substream actually gets closed, but attempting to enqueue more notifications will now
+	/// return an error. It is however possible for the entire connection to be abruptly closed,
+	/// in which case enqueued notifications will be lost.
+	///
+	/// The protocol must have been registered with
+	/// `crate::config::NetworkConfiguration::notifications_protocols`.
+	///
+	/// # Usage
+	///
+	/// This method returns a struct that allows waiting until there is space available in the
+	/// buffer of messages towards the given peer. If the peer processes notifications at a slower
+	/// rate than we send them, this buffer will quickly fill up.
+	///
+	/// As such, you should never do something like this:
+	///
+	/// ```ignore
+	/// // Do NOT do this
+	/// for peer in peers {
+	/// 	if let Ok(n) = network.notification_sender(peer, ...) {
+	/// 			if let Ok(s) = n.ready().await {
+	/// 				let _ = s.send(...);
+	/// 			}
+	/// 	}
+	/// }
+	/// ```
+	///
+	/// Doing so would slow down all peers to the rate of the slowest one. A malicious or
+	/// malfunctioning peer could intentionally process notifications at a very slow rate.
+	///
+	/// Instead, you are encouraged to maintain your own buffer of notifications on top of the one
+	/// maintained by `sc-network`, and use `notification_sender` to progressively send out
+	/// elements from your buffer. If this additional buffer is full (which will happen at some
+	/// point if the peer is too slow to process notifications), appropriate measures can be taken,
+	/// such as removing non-critical notifications from the buffer or disconnecting the peer
+	/// using [`NetworkPeers::disconnect_peer`].
+	///
+	///
+	/// Notifications              Per-peer buffer
+	///   broadcast    +------->   of notifications   +-->  `notification_sender`  +-->  Internet
+	///                    ^       (not covered by
+	///                    |         sc-network)
+	///                    +
+	///      Notifications should be dropped
+	///             if buffer is full
+	///
+	///
+	/// See also the `sc-network-gossip` crate for a higher-level way to send notifications.
+	fn notification_sender(
+		&self,
+		target: PeerId,
+		protocol: Cow<'static, str>,
+	) -> Result<Box<dyn NotificationSender>, NotificationSenderError>;
+}
+
+impl<T> NetworkNotification for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkNotification,
+{
+	fn write_notification(&self, target: PeerId, protocol: Cow<'static, str>, message: Vec<u8>) {
+		T::write_notification(self, target, protocol, message)
+	}
+
+	fn notification_sender(
+		&self,
+		target: PeerId,
+		protocol: Cow<'static, str>,
+	) -> Result<Box<dyn NotificationSender>, NotificationSenderError> {
+		T::notification_sender(self, target, protocol)
+	}
+}
+
+/// Provides ability to send network requests.
+#[async_trait::async_trait]
+pub trait NetworkRequest {
+	/// Sends a single targeted request to a specific peer. On success, returns the response of
+	/// the peer.
+	///
+	/// Request-response protocols are a way to complement notifications protocols, but
+	/// notifications should remain the default ways of communicating information. For example, a
+	/// peer can announce something through a notification, after which the recipient can obtain
+	/// more information by performing a request.
+	/// As such, call this function with `IfDisconnected::ImmediateError` for `connect`. This way
+	/// you will get an error immediately for disconnected peers, instead of waiting for a
+	/// potentially very long connection attempt, which would suggest that something is wrong
+	/// anyway, as you are supposed to be connected because of the notification protocol.
+	///
+	/// No limit or throttling of concurrent outbound requests per peer and protocol are enforced.
+	/// Such restrictions, if desired, need to be enforced at the call site(s).
+	///
+	/// The protocol must have been registered through
+	/// `NetworkConfiguration::request_response_protocols`.
+	async fn request(
+		&self,
+		target: PeerId,
+		protocol: Cow<'static, str>,
+		request: Vec<u8>,
+		connect: IfDisconnected,
+	) -> Result<Vec<u8>, RequestFailure>;
+
+	/// Variation of `request` which starts a request whose response is delivered on a provided
+	/// channel.
+	///
+	/// Instead of blocking and waiting for a reply, this function returns immediately, sending
+	/// responses via the passed in sender. This alternative API exists to make it easier to
+	/// integrate with message passing APIs.
+	///
+	/// Keep in mind that the connected receiver might receive a `Canceled` event in case of a
+	/// closing connection. This is expected behaviour. With `request` you would get a
+	/// `RequestFailure::Network(OutboundFailure::ConnectionClosed)` in that case.
+	fn start_request(
+		&self,
+		target: PeerId,
+		protocol: Cow<'static, str>,
+		request: Vec<u8>,
+		tx: oneshot::Sender<Result<Vec<u8>, RequestFailure>>,
+		connect: IfDisconnected,
+	);
+}
+
+// Manual implementation to avoid extra boxing here
+impl<T> NetworkRequest for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkRequest,
+{
+	fn request<'life0, 'async_trait>(
+		&'life0 self,
+		target: PeerId,
+		protocol: Cow<'static, str>,
+		request: Vec<u8>,
+		connect: IfDisconnected,
+	) -> Pin<Box<dyn Future<Output = Result<Vec<u8>, RequestFailure>> + Send + 'async_trait>>
+	where
+		'life0: 'async_trait,
+		Self: 'async_trait,
+	{
+		T::request(self, target, protocol, request, connect)
+	}
+
+	fn start_request(
+		&self,
+		target: PeerId,
+		protocol: Cow<'static, str>,
+		request: Vec<u8>,
+		tx: oneshot::Sender<Result<Vec<u8>, RequestFailure>>,
+		connect: IfDisconnected,
+	) {
+		T::start_request(self, target, protocol, request, tx, connect)
+	}
+}
+
+/// Provides ability to propagate transactions over the network.
+pub trait NetworkTransaction<H> {
+	/// You may call this when new transactions are imported by the transaction pool.
+	///
+	/// All transactions will be fetched from the `TransactionPool` that was passed at
+	/// initialization as part of the configuration and propagated to peers.
+	fn trigger_repropagate(&self);
+
+	/// You must call when new transaction is imported by the transaction pool.
+	///
+	/// This transaction will be fetched from the `TransactionPool` that was passed at
+	/// initialization as part of the configuration and propagated to peers.
+	fn propagate_transaction(&self, hash: H);
+}
+
+impl<T, H> NetworkTransaction<H> for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkTransaction<H>,
+{
+	fn trigger_repropagate(&self) {
+		T::trigger_repropagate(self)
+	}
+
+	fn propagate_transaction(&self, hash: H) {
+		T::propagate_transaction(self, hash)
+	}
+}
+
+/// Provides ability to announce blocks to the network.
+pub trait NetworkBlock<BlockHash, BlockNumber> {
+	/// Make sure an important block is propagated to peers.
+	///
+	/// In chain-based consensus, we often need to make sure non-best forks are
+	/// at least temporarily synced. This function forces such an announcement.
+	fn announce_block(&self, hash: BlockHash, data: Option<Vec<u8>>);
+
+	/// Inform the network service about new best imported block.
+	fn new_best_block_imported(&self, hash: BlockHash, number: BlockNumber);
+}
+
+impl<T, BlockHash, BlockNumber> NetworkBlock<BlockHash, BlockNumber> for Arc<T>
+where
+	T: ?Sized,
+	T: NetworkBlock<BlockHash, BlockNumber>,
+{
+	fn announce_block(&self, hash: BlockHash, data: Option<Vec<u8>>) {
+		T::announce_block(self, hash, data)
+	}
+
+	fn new_best_block_imported(&self, hash: BlockHash, number: BlockNumber) {
+		T::new_best_block_imported(self, hash, number)
+	}
+}