Make NetworkService callable for ChainSync (#12542)

Introduce a middleware called `NetworkServiceProvider` which the
`ChainSync` can use to communicate with `NetworkService`. `ChainSync` is
given a `NetworkServiceHandle` which it uses to call `NetworkServiceProvider`
which then dispatches the calls to `NetworkService` on behalf of `ChainSync`.

This change will allow `ChainSync` to disconnect and report peers and
in the future it'll be possible to send requests and notifications
through the `NetworkServiceProvider`.

`NetworkServiceProvider` is needed only until the `ChainSync` object
has been removed from `Protocol`. After that, a normal `NetworkService`
handle can be passed onto `ChainSync` and these changes can be
deprecated.

Co-authored-by: parity-processbot <>

substrate/client/network/sync/src/service/mock.rs

@@ -16,10 +16,15 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-use libp2p::PeerId;
-use sc_network_common::service::NetworkSyncForkRequest;
+use sc_network_common::service::{NetworkPeers, NetworkSyncForkRequest};
 use sp_runtime::traits::{Block as BlockT, NumberFor};
 
+pub use libp2p::{identity::error::SigningError, kad::record::Key as KademliaKey};
+use libp2p::{Multiaddr, PeerId};
+use sc_network_common::{config::MultiaddrWithPeerId, protocol::ProtocolName};
+use sc_peerset::ReputationChange;
+use std::collections::HashSet;
+
 mockall::mock! {
 	pub ChainSyncInterface<B: BlockT> {}
 
@@ -29,3 +34,42 @@ mockall::mock! {
 		fn set_sync_fork_request(&self, peers: Vec<PeerId>, hash: B::Hash, number: NumberFor<B>);
 	}
 }
+
+mockall::mock! {
+	pub NetworkServiceHandle {}
+}
+
+// Mocked `Network` for `ChainSync`-related tests
+mockall::mock! {
+	pub Network {}
+
+	impl NetworkPeers for Network {
+		fn set_authorized_peers(&self, peers: HashSet<PeerId>);
+		fn set_authorized_only(&self, reserved_only: bool);
+		fn add_known_address(&self, peer_id: PeerId, addr: Multiaddr);
+		fn report_peer(&self, who: PeerId, cost_benefit: ReputationChange);
+		fn disconnect_peer(&self, who: PeerId, protocol: ProtocolName);
+		fn accept_unreserved_peers(&self);
+		fn deny_unreserved_peers(&self);
+		fn add_reserved_peer(&self, peer: MultiaddrWithPeerId) -> Result<(), String>;
+		fn remove_reserved_peer(&self, peer_id: PeerId);
+		fn set_reserved_peers(
+			&self,
+			protocol: ProtocolName,
+			peers: HashSet<Multiaddr>,
+		) -> Result<(), String>;
+		fn add_peers_to_reserved_set(
+			&self,
+			protocol: ProtocolName,
+			peers: HashSet<Multiaddr>,
+		) -> Result<(), String>;
+		fn remove_peers_from_reserved_set(&self, protocol: ProtocolName, peers: Vec<PeerId>);
+		fn add_to_peers_set(
+			&self,
+			protocol: ProtocolName,
+			peers: HashSet<Multiaddr>,
+		) -> Result<(), String>;
+		fn remove_from_peers_set(&self, protocol: ProtocolName, peers: Vec<PeerId>);
+		fn sync_num_connected(&self) -> usize;
+	}
+}