From 2b3d9aee0fe967083da93f976bcd637e39aff18c Mon Sep 17 00:00:00 2001
From: Aaro Altonen <aaro.altonen@parity.io>
Date: Mon, 10 Oct 2022 10:42:30 +0300
Subject: [PATCH] Companion for paritytech/polkadot#6117

---
 client/relay-chain-minimal-node/Cargo.toml    |  1 +
 .../relay-chain-minimal-node/src/network.rs   | 72 ++++++++++++++++++-
 2 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/client/relay-chain-minimal-node/Cargo.toml b/client/relay-chain-minimal-node/Cargo.toml
index 6c9cb255363..911c33ffc3b 100644
--- a/client/relay-chain-minimal-node/Cargo.toml
+++ b/client/relay-chain-minimal-node/Cargo.toml
@@ -41,6 +41,7 @@ cumulus-relay-chain-interface = { path = "../relay-chain-interface" }
 cumulus-relay-chain-rpc-interface = { path = "../relay-chain-rpc-interface" }
 cumulus-primitives-core = { path = "../../primitives/core" }
 
+array-bytes = "4.1"
 lru = "0.8"
 tracing = "0.1.25"
 async-trait = "0.1.52"
diff --git a/client/relay-chain-minimal-node/src/network.rs b/client/relay-chain-minimal-node/src/network.rs
index a5237f5ea65..2381c68f170 100644
--- a/client/relay-chain-minimal-node/src/network.rs
+++ b/client/relay-chain-minimal-node/src/network.rs
@@ -20,14 +20,21 @@ use polkadot_service::{BlockT, NumberFor};
 use polkadot_node_network_protocol::PeerId;
 use sc_network::{NetworkService, SyncState};
 
-use sc_network_common::sync::{Metrics, SyncStatus};
+use sc_client_api::HeaderBackend;
+use sc_network_common::{
+	config::{
+		NonDefaultSetConfig, NonReservedPeerMode, NotificationHandshake, ProtocolId, SetConfig,
+	},
+	protocol::role::Roles,
+	sync::{message::BlockAnnouncesHandshake, Metrics, SyncStatus},
+};
 use sc_network_light::light_client_requests;
 use sc_network_sync::{block_request_handler, state_request_handler};
 use sc_service::{error::Error, Configuration, NetworkStarter, SpawnTaskHandle};
 use sp_consensus::BlockOrigin;
 use sp_runtime::Justifications;
 
-use std::sync::Arc;
+use std::{iter, sync::Arc};
 
 use crate::BlockChainRpcClient;
 
@@ -59,6 +66,16 @@ pub(crate) fn build_collator_network(
 	let light_client_request_protocol_config =
 		light_client_requests::generate_protocol_config(&protocol_id, genesis_hash, None);
 
+	let chain_sync = DummyChainSync;
+	let block_announce_config = chain_sync.get_block_announce_proto_config(
+		&protocol_id.clone(),
+		None,
+		Roles::from(&config.role),
+		client.info().best_number,
+		client.info().best_hash,
+		genesis_hash,
+	);
+
 	let network_params = sc_network::config::Params {
 		role: config.role.clone(),
 		executor: {
@@ -68,12 +85,13 @@ pub(crate) fn build_collator_network(
 			}))
 		},
 		fork_id: None,
-		chain_sync: Box::new(DummyChainSync),
+		chain_sync: Box::new(chain_sync),
 		network_config: config.network.clone(),
 		chain: client.clone(),
 		import_queue: Box::new(DummyImportQueue),
 		protocol_id,
 		metrics_registry: config.prometheus_config.as_ref().map(|config| config.registry.clone()),
+		// block_announce_config,
 		block_request_protocol_config,
 		state_request_protocol_config,
 		warp_sync_protocol_config: None,
@@ -116,6 +134,54 @@ pub(crate) fn build_collator_network(
 /// we provide a noop implementation.
 struct DummyChainSync;
 
+impl DummyChainSync {
+	pub fn get_block_announce_proto_config<B: BlockT>(
+		&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: 1024 * 1024,
+			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,
+			},
+		}
+	}
+}
+
 impl<B: BlockT> sc_network_common::sync::ChainSync<B> for DummyChainSync {
 	fn peer_info(&self, _who: &PeerId) -> Option<sc_network_common::sync::PeerInfo<B>> {
 		None