malus: add new variant SupportDisabled (#2835)

This variant pretends that nobody is disabled onchain.

polkadot/node/malus/src/malus.rs

@@ -32,6 +32,8 @@ use variants::*;
 enum NemesisVariant {
 	/// Suggest a candidate with an invalid proof of validity.
 	SuggestGarbageCandidate(SuggestGarbageCandidateOptions),
+	/// Support disabled validators in backing and statement distribution.
+	SupportDisabled(SupportDisabledOptions),
 	/// Back a candidate with a specifically crafted proof of validity.
 	BackGarbageCandidate(BackGarbageCandidateOptions),
 	/// Delayed disputing of ancestors that are perfectly fine.
@@ -68,6 +70,11 @@ impl MalusCli {
 					finality_delay,
 				)?
 			},
+			NemesisVariant::SupportDisabled(opts) => {
+				let SupportDisabledOptions { cli } = opts;
+
+				polkadot_cli::run_node(cli, SupportDisabled, finality_delay)?
+			},
 			NemesisVariant::DisputeAncestor(opts) => {
 				let DisputeAncestorOptions {
 					fake_validation,

polkadot/node/malus/src/variants/mod.rs

@@ -21,11 +21,13 @@ mod common;
 mod dispute_finalized_candidates;
 mod dispute_valid_candidates;
 mod suggest_garbage_candidate;
+mod support_disabled;
 
 pub(crate) use self::{
 	back_garbage_candidate::{BackGarbageCandidateOptions, BackGarbageCandidates},
 	dispute_finalized_candidates::{DisputeFinalizedCandidates, DisputeFinalizedCandidatesOptions},
 	dispute_valid_candidates::{DisputeAncestorOptions, DisputeValidCandidates},
 	suggest_garbage_candidate::{SuggestGarbageCandidateOptions, SuggestGarbageCandidates},
+	support_disabled::{SupportDisabled, SupportDisabledOptions},
 };
 pub(crate) use common::*;

polkadot/node/malus/src/variants/support_disabled.rs

@@ -0,0 +1,98 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! This variant of Malus overrides the `disabled_validators` runtime API
+//! to always return an empty set of disabled validators.
+
+use polkadot_cli::{
+	prepared_overseer_builder,
+	service::{
+		AuthorityDiscoveryApi, AuxStore, BabeApi, Block, Error, HeaderBackend, Overseer,
+		OverseerConnector, OverseerGen, OverseerGenArgs, OverseerHandle, ParachainHost,
+		ProvideRuntimeApi,
+	},
+	Cli,
+};
+use polkadot_node_subsystem::SpawnGlue;
+use polkadot_node_subsystem_types::DefaultSubsystemClient;
+use sp_core::traits::SpawnNamed;
+
+use crate::interceptor::*;
+
+use std::sync::Arc;
+
+#[derive(Debug, clap::Parser)]
+#[clap(rename_all = "kebab-case")]
+#[allow(missing_docs)]
+pub struct SupportDisabledOptions {
+	#[clap(flatten)]
+	pub cli: Cli,
+}
+
+/// Generates an overseer with a custom runtime API subsystem.
+pub(crate) struct SupportDisabled;
+
+impl OverseerGen for SupportDisabled {
+	fn generate<Spawner, RuntimeClient>(
+		&self,
+		connector: OverseerConnector,
+		args: OverseerGenArgs<'_, Spawner, RuntimeClient>,
+	) -> Result<
+		(Overseer<SpawnGlue<Spawner>, Arc<DefaultSubsystemClient<RuntimeClient>>>, OverseerHandle),
+		Error,
+	>
+	where
+		RuntimeClient: 'static + ProvideRuntimeApi<Block> + HeaderBackend<Block> + AuxStore,
+		RuntimeClient::Api: ParachainHost<Block> + BabeApi<Block> + AuthorityDiscoveryApi<Block>,
+		Spawner: 'static + SpawnNamed + Clone + Unpin,
+	{
+		prepared_overseer_builder(args)?
+			.replace_runtime_api(move |ra_subsystem| {
+				InterceptedSubsystem::new(ra_subsystem, IgnoreDisabled)
+			})
+			.build_with_connector(connector)
+			.map_err(|e| e.into())
+	}
+}
+
+#[derive(Clone)]
+struct IgnoreDisabled;
+
+impl<Sender> MessageInterceptor<Sender> for IgnoreDisabled
+where
+	Sender: overseer::RuntimeApiSenderTrait + Clone + Send + 'static,
+{
+	type Message = RuntimeApiMessage;
+
+	/// Intercept incoming runtime api requests.
+	fn intercept_incoming(
+		&self,
+		_subsystem_sender: &mut Sender,
+		msg: FromOrchestra<Self::Message>,
+	) -> Option<FromOrchestra<Self::Message>> {
+		match msg {
+			FromOrchestra::Communication {
+				msg:
+					RuntimeApiMessage::Request(_relay_parent, RuntimeApiRequest::DisabledValidators(tx)),
+			} => {
+				let _ = tx.send(Ok(Vec::new()));
+				None
+			},
+			FromOrchestra::Communication { msg } => Some(FromOrchestra::Communication { msg }),
+			FromOrchestra::Signal(signal) => Some(FromOrchestra::Signal(signal)),
+		}
+	}
+}

prdoc/pr_2835.prdoc

@@ -0,0 +1,9 @@
+title: New malus variant `support-disabled`
+
+doc:
+  - audience: Node Dev
+    description: |
+      A new malicious flavor added to pretend that nobody
+      is disabled onchain.
+
+crates: [ ]