Move block announcement protocol config out of Protocol (#12441)

* Move Role(s) to `sc-network-common`

* Introduce `NotificationHandshake` type

* Move block announce protocol config creation to `ChainSync`

* Include block announcement into `notification_protocols`

* Apply review comments

* Remove unneeded include

* Add missing include

* Apply review comments

substrate/client/network/sync/src/lib.rs

@@ -50,15 +50,21 @@ use log::{debug, error, info, trace, warn};
 use prost::Message;
 use sc_client_api::{BlockBackend, ProofProvider};
 use sc_consensus::{BlockImportError, BlockImportStatus, IncomingBlock};
-use sc_network_common::sync::{
-	message::{
-		BlockAnnounce, BlockAttributes, BlockData, BlockRequest, BlockResponse, Direction,
-		FromBlock,
+use sc_network_common::{
+	config::{
+		NonDefaultSetConfig, NonReservedPeerMode, NotificationHandshake, ProtocolId, SetConfig,
+	},
+	protocol::role::Roles,
+	sync::{
+		message::{
+			BlockAnnounce, BlockAnnouncesHandshake, BlockAttributes, BlockData, BlockRequest,
+			BlockResponse, Direction, FromBlock,
+		},
+		warp::{EncodedProof, WarpProofRequest, WarpSyncPhase, WarpSyncProgress, WarpSyncProvider},
+		BadPeer, ChainSync as ChainSyncT, Metrics, OnBlockData, OnBlockJustification, OnStateData,
+		OpaqueBlockRequest, OpaqueBlockResponse, OpaqueStateRequest, OpaqueStateResponse, PeerInfo,
+		PollBlockAnnounceValidation, SyncMode, SyncState, SyncStatus,
 	},
-	warp::{EncodedProof, WarpProofRequest, WarpSyncPhase, WarpSyncProgress, WarpSyncProvider},
-	BadPeer, ChainSync as ChainSyncT, Metrics, OnBlockData, OnBlockJustification, OnStateData,
-	OpaqueBlockRequest, OpaqueBlockResponse, OpaqueStateRequest, OpaqueStateResponse, PeerInfo,
-	PollBlockAnnounceValidation, SyncMode, SyncState, SyncStatus,
 };
 use sp_arithmetic::traits::Saturating;
 use sp_blockchain::{Error as ClientError, HeaderBackend, HeaderMetadata};
@@ -76,6 +82,7 @@ use sp_runtime::{
 };
 use std::{
 	collections::{hash_map::Entry, HashMap, HashSet},
+	iter,
 	ops::Range,
 	pin::Pin,
 	sync::Arc,
@@ -121,6 +128,9 @@ const MAJOR_SYNC_BLOCKS: u8 = 5;
 /// Number of peers that need to be connected before warp sync is started.
 const MIN_PEERS_TO_START_WARP_SYNC: usize = 3;
 
+/// Maximum allowed size for a block announce.
+const MAX_BLOCK_ANNOUNCE_SIZE: u64 = 1024 * 1024;
+
 mod rep {
 	use sc_peerset::ReputationChange as Rep;
 	/// Reputation change when a peer sent us a message that led to a
@@ -2231,6 +2241,53 @@ where
 		}
 		None
 	}
+
+	/// Get config for the block announcement protocol
+	pub fn get_block_announce_proto_config(
+		&self,
+		protocol_id: ProtocolId,
+		fork_id: &Option<String>,
+		roles: Roles,
+		best_number: NumberFor<B>,
+		best_hash: B::Hash,
+		genesis_hash: B::Hash,
+	) -> NonDefaultSetConfig {
+		let block_announces_protocol = {
+			let genesis_hash = genesis_hash.as_ref();
+			if let Some(ref fork_id) = fork_id {
+				format!(
+					"/{}/{}/block-announces/1",
+					array_bytes::bytes2hex("", genesis_hash),
+					fork_id
+				)
+			} else {
+				format!("/{}/block-announces/1", array_bytes::bytes2hex("", genesis_hash))
+			}
+		};
+
+		NonDefaultSetConfig {
+			notifications_protocol: block_announces_protocol.into(),
+			fallback_names: iter::once(
+				format!("/{}/block-announces/1", protocol_id.as_ref()).into(),
+			)
+			.collect(),
+			max_notification_size: MAX_BLOCK_ANNOUNCE_SIZE,
+			handshake: Some(NotificationHandshake::new(BlockAnnouncesHandshake::<B>::build(
+				roles,
+				best_number,
+				best_hash,
+				genesis_hash,
+			))),
+			// NOTE: `set_config` will be ignored by `protocol.rs` as the block announcement
+			// protocol is still hardcoded into the peerset.
+			set_config: SetConfig {
+				in_peers: 0,
+				out_peers: 0,
+				reserved_nodes: Vec::new(),
+				non_reserved_mode: NonReservedPeerMode::Deny,
+			},
+		}
+	}
 }
 
 // This is purely during a backwards compatible transitionary period and should be removed