Remove HeaderBackend requirement from AuthorityDiscovery and NetworkWorker (#13730)

* Remove `HeaderBackend` requirement from `NetworkWorker`

* Remove HeaderBackend from authority-discovery

substrate/client/network/src/config.rs

@@ -34,6 +34,7 @@ use prometheus_endpoint::Registry;
 pub use sc_network_common::{role::Role, sync::warp::WarpSyncProvider, ExHashT};
 use zeroize::Zeroize;
 
+use sp_runtime::traits::Block as BlockT;
 use std::{
 	error::Error,
 	fmt, fs,
@@ -44,7 +45,6 @@ use std::{
 	path::{Path, PathBuf},
 	pin::Pin,
 	str::{self, FromStr},
-	sync::Arc,
 };
 
 pub use libp2p::{
@@ -688,7 +688,7 @@ impl NetworkConfiguration {
 }
 
 /// Network initialization parameters.
-pub struct Params<Client> {
+pub struct Params<Block: BlockT> {
 	/// Assigned role for our node (full, light, ...).
 	pub role: Role,
 
@@ -698,12 +698,12 @@ pub struct Params<Client> {
 	/// Network layer configuration.
 	pub network_config: NetworkConfiguration,
 
-	/// Client that contains the blockchain.
-	pub chain: Arc<Client>,
-
 	/// Legacy name of the protocol to use on the wire. Should be different for each chain.
 	pub protocol_id: ProtocolId,
 
+	/// Genesis hash of the chain
+	pub genesis_hash: Block::Hash,
+
 	/// Fork ID to distinguish protocols of different hard forks. Part of the standard protocol
 	/// name on the wire.
 	pub fork_id: Option<String>,

substrate/client/network/src/service.rs

@@ -73,8 +73,7 @@ use parking_lot::Mutex;
 use sc_network_common::ExHashT;
 use sc_peerset::PeersetHandle;
 use sc_utils::mpsc::{tracing_unbounded, TracingUnboundedReceiver, TracingUnboundedSender};
-use sp_blockchain::HeaderBackend;
-use sp_runtime::traits::{Block as BlockT, Zero};
+use sp_runtime::traits::Block as BlockT;
 
 use std::{
 	cmp,
@@ -147,9 +146,7 @@ where
 	/// Returns a `NetworkWorker` that implements `Future` and must be regularly polled in order
 	/// for the network processing to advance. From it, you can extract a `NetworkService` using
 	/// `worker.service()`. The `NetworkService` can be shared through the codebase.
-	pub fn new<Client: HeaderBackend<B> + 'static>(
-		mut params: Params<Client>,
-	) -> Result<Self, Error> {
+	pub fn new<Block: BlockT>(mut params: Params<Block>) -> Result<Self, Error> {
 		// Private and public keys configuration.
 		let local_identity = params.network_config.node_key.clone().into_keypair()?;
 		let local_public = local_identity.public();
@@ -277,13 +274,11 @@ where
 				config.discovery_limit(
 					u64::from(params.network_config.default_peers_set.out_peers) + 15,
 				);
-				let genesis_hash = params
-					.chain
-					.hash(Zero::zero())
-					.ok()
-					.flatten()
-					.expect("Genesis block exists; qed");
-				config.with_kademlia(genesis_hash, params.fork_id.as_deref(), &params.protocol_id);
+				config.with_kademlia(
+					params.genesis_hash,
+					params.fork_id.as_deref(),
+					&params.protocol_id,
+				);
 				config.with_dht_random_walk(params.network_config.enable_dht_random_walk);
 				config.allow_non_globals_in_dht(params.network_config.allow_non_globals_in_dht);
 				config.use_kademlia_disjoint_query_paths(