Revert "Remove NetworkSpecialization (#4665)"

This reverts commit 3cc0973.

bin/node-template/node/src/service.rs

@@ -6,6 +6,7 @@ use sc_client::LongestChain;
 use node_template_runtime::{self, GenesisConfig, opaque::Block, RuntimeApi};
 use sc_service::{error::{Error as ServiceError}, AbstractService, Configuration, ServiceBuilder};
 use sp_inherents::InherentDataProviders;
+use sc_network::{construct_simple_protocol};
 use sc_executor::native_executor_instance;
 pub use sc_executor::NativeExecutor;
 use sp_consensus_aura::sr25519::{AuthorityPair as AuraPair};
@@ -18,6 +19,11 @@ native_executor_instance!(
 	node_template_runtime::native_version,
 );
 
+construct_simple_protocol! {
+	/// Demo protocol attachment for substrate.
+	pub struct NodeProtocol where Block = Block { }
+}
+
 /// Starts a `ServiceBuilder` for a full service.
 ///
 /// Use this macro if you don't actually need the full service, but just the builder in order to
@@ -88,7 +94,7 @@ pub fn new_full(config: Configuration<GenesisConfig>)
 		import_setup.take()
 			.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
 
-	let service = builder
+	let service = builder.with_network_protocol(|_| Ok(NodeProtocol::new()))?
 		.with_finality_proof_provider(|client, backend|
 			Ok(Arc::new(GrandpaFinalityProofProvider::new(backend, client)) as _)
 		)?
@@ -220,6 +226,7 @@ pub fn new_light(config: Configuration<GenesisConfig>)
 
 			Ok((import_queue, finality_proof_request_builder))
 		})?
+		.with_network_protocol(|_| Ok(NodeProtocol::new()))?
 		.with_finality_proof_provider(|client, backend|
 			Ok(Arc::new(GrandpaFinalityProofProvider::new(backend, client)) as _)
 		)?

bin/node/cli/src/service.rs

@@ -30,6 +30,7 @@ use sc_service::{
 	AbstractService, ServiceBuilder, config::Configuration, error::{Error as ServiceError},
 };
 use sp_inherents::InherentDataProviders;
+use sc_network::construct_simple_protocol;
 
 use sc_service::{Service, NetworkStatus};
 use sc_client::{Client, LocalCallExecutor};
@@ -39,6 +40,11 @@ use node_executor::NativeExecutor;
 use sc_network::NetworkService;
 use sc_offchain::OffchainWorkers;
 
+construct_simple_protocol! {
+	/// Demo protocol attachment for substrate.
+	pub struct NodeProtocol where Block = Block { }
+}
+
 /// Starts a `ServiceBuilder` for a full service.
 ///
 /// Use this macro if you don't actually need the full service, but just the builder in order to
@@ -138,7 +144,7 @@ macro_rules! new_full {
 
 		let (builder, mut import_setup, inherent_data_providers) = new_full_start!($config);
 
-		let service = builder
+		let service = builder.with_network_protocol(|_| Ok(crate::service::NodeProtocol::new()))?
 			.with_finality_proof_provider(|client, backend|
 				Ok(Arc::new(grandpa::FinalityProofProvider::new(backend, client)) as _)
 			)?
@@ -277,7 +283,7 @@ pub fn new_full(config: NodeConfiguration)
 		ConcreteClient,
 		LongestChain<ConcreteBackend, ConcreteBlock>,
 		NetworkStatus<ConcreteBlock>,
-		NetworkService<ConcreteBlock, <ConcreteBlock as BlockT>::Hash>,
+		NetworkService<ConcreteBlock, crate::service::NodeProtocol, <ConcreteBlock as BlockT>::Hash>,
 		ConcreteTransactionPool,
 		OffchainWorkers<
 			ConcreteClient,
@@ -342,6 +348,7 @@ pub fn new_light(config: NodeConfiguration)
 
 			Ok((import_queue, finality_proof_request_builder))
 		})?
+		.with_network_protocol(|_| Ok(NodeProtocol::new()))?
 		.with_finality_proof_provider(|client, backend|
 			Ok(Arc::new(GrandpaFinalityProofProvider::new(backend, client)) as _)
 		)?

client/authority-discovery/src/lib.rs

@@ -60,6 +60,7 @@ use libp2p::Multiaddr;
 use log::{debug, error, log_enabled, warn};
 use prost::Message;
 use sc_client_api::blockchain::HeaderBackend;
+use sc_network::specialization::NetworkSpecialization;
 use sc_network::{DhtEvent, ExHashT, NetworkStateInfo};
 use sp_authority_discovery::{AuthorityDiscoveryApi, AuthorityId, AuthoritySignature, AuthorityPair};
 use sp_core::crypto::{key_types, Pair};
@@ -476,9 +477,10 @@ pub trait NetworkProvider: NetworkStateInfo {
 	fn get_value(&self, key: &libp2p::kad::record::Key);
 }
 
-impl<B, H> NetworkProvider for sc_network::NetworkService<B, H>
+impl<B, S, H> NetworkProvider for sc_network::NetworkService<B, S, H>
 where
 	B: BlockT + 'static,
+	S: NetworkSpecialization<B>,
 	H: ExHashT,
 {
 	fn set_priority_group(

client/consensus/aura/src/lib.rs

@@ -886,10 +886,11 @@ mod tests {
 	const SLOT_DURATION: u64 = 1000;
 
 	pub struct AuraTestNet {
-		peers: Vec<Peer<()>>,
+		peers: Vec<Peer<(), DummySpecialization>>,
 	}
 
 	impl TestNetFactory for AuraTestNet {
+		type Specialization = DummySpecialization;
 		type Verifier = AuraVerifier<PeersFullClient, AuthorityPair>;
 		type PeerData = ();
 
@@ -923,15 +924,15 @@ mod tests {
 			}
 		}
 
-		fn peer(&mut self, i: usize) -> &mut Peer<Self::PeerData> {
+		fn peer(&mut self, i: usize) -> &mut Peer<Self::PeerData, DummySpecialization> {
 			&mut self.peers[i]
 		}
 
-		fn peers(&self) -> &Vec<Peer<Self::PeerData>> {
+		fn peers(&self) -> &Vec<Peer<Self::PeerData, DummySpecialization>> {
 			&self.peers
 		}
 
-		fn mut_peers<F: FnOnce(&mut Vec<Peer<Self::PeerData>>)>(&mut self, closure: F) {
+		fn mut_peers<F: FnOnce(&mut Vec<Peer<Self::PeerData, DummySpecialization>>)>(&mut self, closure: F) {
 			closure(&mut self.peers);
 		}
 	}

client/consensus/babe/src/tests.rs

@@ -199,7 +199,7 @@ impl<B: BlockImport<TestBlock>> BlockImport<TestBlock> for PanickingBlockImport<
 }
 
 pub struct BabeTestNet {
-	peers: Vec<Peer<Option<PeerData>>>,
+	peers: Vec<Peer<Option<PeerData>, DummySpecialization>>,
 }
 
 type TestHeader = <TestBlock as BlockT>::Header;
@@ -236,6 +236,7 @@ pub struct PeerData {
 }
 
 impl TestNetFactory for BabeTestNet {
+	type Specialization = DummySpecialization;
 	type Verifier = TestVerifier;
 	type PeerData = Option<PeerData>;
 
@@ -306,17 +307,17 @@ impl TestNetFactory for BabeTestNet {
 		}
 	}
 
-	fn peer(&mut self, i: usize) -> &mut Peer<Self::PeerData> {
+	fn peer(&mut self, i: usize) -> &mut Peer<Self::PeerData, DummySpecialization> {
 		trace!(target: "babe", "Retrieving a peer");
 		&mut self.peers[i]
 	}
 
-	fn peers(&self) -> &Vec<Peer<Self::PeerData>> {
+	fn peers(&self) -> &Vec<Peer<Self::PeerData, DummySpecialization>> {
 		trace!(target: "babe", "Retrieving peers");
 		&self.peers
 	}
 
-	fn mut_peers<F: FnOnce(&mut Vec<Peer<Self::PeerData>>)>(
+	fn mut_peers<F: FnOnce(&mut Vec<Peer<Self::PeerData, DummySpecialization>>)>(
 		&mut self,
 		closure: F,
 	) {

client/finality-grandpa/src/communication/mod.rs

@@ -120,8 +120,9 @@ pub trait Network<Block: BlockT>: GossipNetwork<Block> + Clone + Send + 'static
 	fn set_sync_fork_request(&self, peers: Vec<sc_network::PeerId>, hash: Block::Hash, number: NumberFor<Block>);
 }
 
-impl<B, H> Network<B> for Arc<NetworkService<B, H>> where
+impl<B, S, H> Network<B> for Arc<NetworkService<B, S, H>> where
 	B: BlockT,
+	S: sc_network::specialization::NetworkSpecialization<B>,
 	H: sc_network::ExHashT,
 {
 	fn set_sync_fork_request(&self, peers: Vec<sc_network::PeerId>, hash: B::Hash, number: NumberFor<B>) {

client/finality-grandpa/src/tests.rs

@@ -19,7 +19,7 @@
 use super::*;
 use environment::HasVoted;
 use sc_network_test::{
-	Block, Hash, TestNetFactory, BlockImportAdapter, Peer,
+	Block, DummySpecialization, Hash, TestNetFactory, BlockImportAdapter, Peer,
 	PeersClient, PassThroughVerifier,
 };
 use sc_network::config::{ProtocolConfig, Roles, BoxFinalityProofRequestBuilder};
@@ -68,7 +68,7 @@ type PeerData =
 			>
 		>
 	>;
-type GrandpaPeer = Peer<PeerData>;
+type GrandpaPeer = Peer<PeerData, DummySpecialization>;
 
 struct GrandpaTestNet {
 	peers: Vec<GrandpaPeer>,
@@ -90,6 +90,7 @@ impl GrandpaTestNet {
 }
 
 impl TestNetFactory for GrandpaTestNet {
+	type Specialization = DummySpecialization;
 	type Verifier = PassThroughVerifier;
 	type PeerData = PeerData;
 

client/network-gossip/src/lib.rs

@@ -59,7 +59,7 @@ pub use self::state_machine::TopicNotification;
 pub use self::validator::{DiscardAll, MessageIntent, Validator, ValidatorContext, ValidationResult};
 
 use futures::prelude::*;
-use sc_network::{Event, ExHashT, NetworkService, PeerId, ReputationChange};
+use sc_network::{specialization::NetworkSpecialization, Event, ExHashT, NetworkService, PeerId, ReputationChange};
 use sp_runtime::{traits::Block as BlockT, ConsensusEngineId};
 use std::{borrow::Cow, pin::Pin, sync::Arc};
 
@@ -97,7 +97,7 @@ pub trait Network<B: BlockT> {
 	fn announce(&self, block: B::Hash, associated_data: Vec<u8>);
 }
 
-impl<B: BlockT, H: ExHashT> Network<B> for Arc<NetworkService<B, H>> {
+impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Network<B> for Arc<NetworkService<B, S, H>> {
 	fn event_stream(&self) -> Pin<Box<dyn Stream<Item = Event> + Send>> {
 		Box::pin(NetworkService::event_stream(self))
 	}

client/network/src/behaviour.rs

@@ -16,8 +16,9 @@
 
 use crate::{
 	debug_info, discovery::DiscoveryBehaviour, discovery::DiscoveryOut, DiscoveryNetBehaviour,
-	Event, protocol::event::DhtEvent, ExHashT,
+	Event, protocol::event::DhtEvent
 };
+use crate::{ExHashT, specialization::NetworkSpecialization};
 use crate::protocol::{self, light_client_handler, CustomMessageOutcome, Protocol};
 use libp2p::NetworkBehaviour;
 use libp2p::core::{Multiaddr, PeerId, PublicKey};
@@ -32,9 +33,9 @@ use void;
 /// General behaviour of the network. Combines all protocols together.
 #[derive(NetworkBehaviour)]
 #[behaviour(out_event = "BehaviourOut<B>", poll_method = "poll")]
-pub struct Behaviour<B: BlockT, H: ExHashT> {
+pub struct Behaviour<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> {
 	/// All the substrate-specific protocols.
-	substrate: Protocol<B, H>,
+	substrate: Protocol<B, S, H>,
 	/// Periodically pings and identifies the nodes we are connected to, and store information in a
 	/// cache.
 	debug_info: debug_info::DebugInfoBehaviour,
@@ -57,10 +58,10 @@ pub enum BehaviourOut<B: BlockT> {
 	Event(Event),
 }
 
-impl<B: BlockT, H: ExHashT> Behaviour<B, H> {
+impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Behaviour<B, S, H> {
 	/// Builds a new `Behaviour`.
 	pub async fn new(
-		substrate: Protocol<B, H>,
+		substrate: Protocol<B, S, H>,
 		user_agent: String,
 		local_public_key: PublicKey,
 		known_addresses: Vec<(PeerId, Multiaddr)>,
@@ -106,12 +107,12 @@ impl<B: BlockT, H: ExHashT> Behaviour<B, H> {
 	}
 
 	/// Returns a shared reference to the user protocol.
-	pub fn user_protocol(&self) -> &Protocol<B, H> {
+	pub fn user_protocol(&self) -> &Protocol<B, S, H> {
 		&self.substrate
 	}
 
 	/// Returns a mutable reference to the user protocol.
-	pub fn user_protocol_mut(&mut self) -> &mut Protocol<B, H> {
+	pub fn user_protocol_mut(&mut self) -> &mut Protocol<B, S, H> {
 		&mut self.substrate
 	}
 
@@ -132,15 +133,15 @@ impl<B: BlockT, H: ExHashT> Behaviour<B, H> {
 	}
 }
 
-impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<void::Void> for
-Behaviour<B, H> {
+impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> NetworkBehaviourEventProcess<void::Void> for
+Behaviour<B, S, H> {
 	fn inject_event(&mut self, event: void::Void) {
 		void::unreachable(event)
 	}
 }
 
-impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<CustomMessageOutcome<B>> for
-Behaviour<B, H> {
+impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> NetworkBehaviourEventProcess<CustomMessageOutcome<B>> for
+Behaviour<B, S, H> {
 	fn inject_event(&mut self, event: CustomMessageOutcome<B>) {
 		match event {
 			CustomMessageOutcome::BlockImport(origin, blocks) =>
@@ -173,8 +174,8 @@ Behaviour<B, H> {
 	}
 }
 
-impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<debug_info::DebugInfoEvent>
-	for Behaviour<B, H> {
+impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> NetworkBehaviourEventProcess<debug_info::DebugInfoEvent>
+	for Behaviour<B, S, H> {
 	fn inject_event(&mut self, event: debug_info::DebugInfoEvent) {
 		let debug_info::DebugInfoEvent::Identified { peer_id, mut info } = event;
 		if info.listen_addrs.len() > 30 {
@@ -191,8 +192,8 @@ impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<debug_info::DebugInfoEv
 	}
 }
 
-impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<DiscoveryOut>
-	for Behaviour<B, H> {
+impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> NetworkBehaviourEventProcess<DiscoveryOut>
+	for Behaviour<B, S, H> {
 	fn inject_event(&mut self, out: DiscoveryOut) {
 		match out {
 			DiscoveryOut::UnroutablePeer(_peer_id) => {
@@ -220,7 +221,7 @@ impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<DiscoveryOut>
 	}
 }
 
-impl<B: BlockT, H: ExHashT> Behaviour<B, H> {
+impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Behaviour<B, S, H> {
 	fn poll<TEv>(&mut self, _: &mut Context, _: &mut impl PollParameters) -> Poll<NetworkBehaviourAction<TEv, BehaviourOut<B>>> {
 		if !self.events.is_empty() {
 			return Poll::Ready(NetworkBehaviourAction::GenerateEvent(self.events.remove(0)))

client/network/src/config.rs

@@ -43,7 +43,7 @@ use std::{error::Error, fs, io::{self, Write}, net::Ipv4Addr, path::{Path, PathB
 use zeroize::Zeroize;
 
 /// Network initialization parameters.
-pub struct Params<B: BlockT, H: ExHashT> {
+pub struct Params<B: BlockT, S, H: ExHashT> {
 	/// Assigned roles for our node (full, light, ...).
 	pub roles: Roles,
 
@@ -88,6 +88,9 @@ pub struct Params<B: BlockT, H: ExHashT> {
 	/// valid.
 	pub import_queue: Box<dyn ImportQueue<B>>,
 
+	/// Customization of the network. Use this to plug additional networking capabilities.
+	pub specialization: S,
+
 	/// Type to check incoming block announcements.
 	pub block_announce_validator: Box<dyn BlockAnnounceValidator<B> + Send>,
 }

client/network/src/lib.rs

@@ -136,6 +136,10 @@
 //! - Light-client requests. When a light client requires information, a random node we have a
 //! substream open with is chosen, and the information is requested from it.
 //! - Gossiping. Used for example by grandpa.
+//! - Network specialization. The network protocol can be specialized through a template parameter
+//! of the network service. This specialization is free to send and receive messages with the
+//! remote. This is meant to be used by the chain that is being built on top of Substrate
+//! (eg. Polkadot).
 //!
 //! It is intended that in the future each of these components gets more isolated, so that they
 //! are free to open and close their own substreams, and so that syncing and light client requests
@@ -176,7 +180,7 @@ pub mod error;
 pub mod network_state;
 
 pub use service::{NetworkService, NetworkStateInfo, NetworkWorker, ExHashT, ReportHandle};
-pub use protocol::PeerInfo;
+pub use protocol::{PeerInfo, Context, specialization};
 pub use protocol::event::{Event, DhtEvent};
 pub use protocol::sync::SyncState;
 pub use libp2p::{Multiaddr, PeerId};
@@ -192,6 +196,10 @@ pub use protocol::message::Status as StatusMessage;
 
 pub use sc_peerset::ReputationChange;
 
+// Used by the `construct_simple_protocol!` macro.
+#[doc(hidden)]
+pub use sp_runtime::traits::Block as BlockT;
+
 /// Extension trait for `NetworkBehaviour` that also accepts discovering nodes.
 trait DiscoveryNetBehaviour {
 	/// Notify the protocol that we have learned about the existence of nodes.