malus-collator: implement malicious collator submitting same collation to all backing groups (#6924)

## Issues
- [[#5049] Elastic scaling: zombienet
tests](#5049)
- [[#4526] Add zombienet tests for malicious
collators](#4526)

## Description
Modified the undying collator to include a malus mode, in which it
submits the same collation to all assigned backing groups.

## TODO
* [X] Implement malicious collator that submits the same collation to
all backing groups;
* [X] Avoid the core index check in the collation generation subsystem:
https://github.com/paritytech/polkadot-sdk/blob/master/polkadot/node/collation-generation/src/lib.rs#L552-L553;
* [X] Resolve the mismatch between the descriptor and the commitments
core index: #7104
* [X] Implement `duplicate_collations` test with zombienet-sdk;
* [X] Add PRdoc.

Author: sw10pa

.gitlab/pipeline/zombienet/polkadot.yml

@@ -464,3 +464,19 @@ zombienet-polkadot-functional-async-backing-6-seconds-rate:
     - unset NEXTEST_FAILURE_OUTPUT
     - unset NEXTEST_SUCCESS_OUTPUT
     - cargo nextest run --archive-file ./artifacts/polkadot-zombienet-tests.tar.zst --no-capture -- functional::async_backing_6_seconds_rate::async_backing_6_seconds_rate_test
+
+zombienet-polkadot-functional-duplicate-collations:
+  extends:
+    - .zombienet-polkadot-common
+  needs:
+    - job: build-polkadot-zombienet-tests
+      artifacts: true
+  before_script:
+    - !reference [ ".zombienet-polkadot-common", "before_script" ]
+    - export POLKADOT_IMAGE="${ZOMBIENET_INTEGRATION_TEST_IMAGE}"
+    - export X_INFRA_INSTANCE=spot # use spot by default
+  script:
+    # we want to use `--no-capture` in zombienet tests.
+    - unset NEXTEST_FAILURE_OUTPUT
+    - unset NEXTEST_SUCCESS_OUTPUT
+    - cargo nextest run --archive-file ./artifacts/polkadot-zombienet-tests.tar.zst --no-capture -- functional::duplicate_collations::duplicate_collations_test

Cargo.lock

@@ -18,7 +18,8 @@
 
 use pallet_staking::Forcing;
 use polkadot_primitives::{
-	AccountId, AssignmentId, SchedulerParams, ValidatorId, MAX_CODE_SIZE, MAX_POV_SIZE,
+	node_features, AccountId, AssignmentId, NodeFeatures, SchedulerParams, ValidatorId,
+	MAX_CODE_SIZE, MAX_POV_SIZE,
 };
 use polkadot_service::chain_spec::Extensions;
 use polkadot_test_runtime::BABE_GENESIS_EPOCH_CONFIG;
@@ -110,6 +111,11 @@ fn polkadot_testnet_genesis(
 	const ENDOWMENT: u128 = 1_000_000 * DOTS;
 	const STASH: u128 = 100 * DOTS;
 
+	// Prepare node features with V2 receipts enabled.
+	let mut node_features = NodeFeatures::new();
+	node_features.resize(node_features::FeatureIndex::CandidateReceiptV2 as usize + 1, false);
+	node_features.set(node_features::FeatureIndex::CandidateReceiptV2 as u8 as usize, true);
+
 	serde_json::json!({
 		"balances": {
 			"balances": endowed_accounts.iter().map(|k| (k.clone(), ENDOWMENT)).collect::<Vec<_>>(),
@@ -158,6 +164,7 @@ fn polkadot_testnet_genesis(
 				no_show_slots: 10,
 				minimum_validation_upgrade_delay: 5,
 				max_downward_message_size: 1024,
+				node_features,
 				scheduler_params: SchedulerParams {
 					group_rotation_frequency: 20,
 					paras_availability_period: 4,

polkadot/node/test/service/src/chain_spec.rs

@@ -16,6 +16,7 @@ codec = { features = ["derive"], workspace = true }
 dlmalloc = { features = ["global"], workspace = true }
 log = { workspace = true }
 polkadot-parachain-primitives = { features = ["wasm-api"], workspace = true }
+polkadot-primitives = { workspace = true, default-features = false }
 tiny-keccak = { features = ["keccak"], workspace = true }
 
 # We need to make sure the global allocator is disabled until we have support of full substrate externalities
@@ -30,5 +31,6 @@ std = [
 	"codec/std",
 	"log/std",
 	"polkadot-parachain-primitives/std",
+	"polkadot-primitives/std",
 	"sp-io/std",
 ]

polkadot/parachain/test-parachains/undying/Cargo.toml

@@ -22,13 +22,15 @@ futures-timer = { workspace = true }
 log = { workspace = true, default-features = true }
 
 polkadot-cli = { workspace = true, default-features = true }
+polkadot-erasure-coding = { workspace = true, default-features = true }
 polkadot-node-primitives = { workspace = true, default-features = true }
 polkadot-node-subsystem = { workspace = true, default-features = true }
 polkadot-primitives = { workspace = true, default-features = true }
 polkadot-service = { features = ["rococo-native"], workspace = true, default-features = true }
 test-parachain-undying = { workspace = true }
 
 sc-cli = { workspace = true, default-features = true }
+sc-client-api = { workspace = true, default-features = true }
 sc-service = { workspace = true, default-features = true }
 sp-core = { workspace = true, default-features = true }
 

polkadot/parachain/test-parachains/undying/collator/Cargo.toml

@@ -61,6 +61,15 @@ pub struct ExportGenesisWasmCommand {
 	pub output: Option<PathBuf>,
 }
 
+/// Enum representing different types of malicious behaviors for collators.
+#[derive(Debug, Parser, Clone, PartialEq, clap::ValueEnum)]
+pub enum MalusType {
+	/// No malicious behavior.
+	None,
+	/// Submit the same collations to all assigned cores.
+	DuplicateCollations,
+}
+
 #[allow(missing_docs)]
 #[derive(Debug, Parser)]
 #[group(skip)]
@@ -81,6 +90,10 @@ pub struct RunCmd {
 	/// we compute per block.
 	#[arg(long, default_value_t = 1)]
 	pub pvf_complexity: u32,
+
+	/// Specifies the malicious behavior of the collator.
+	#[arg(long, value_enum, default_value_t = MalusType::None)]
+	pub malus_type: MalusType,
 }
 
 #[allow(missing_docs)]