From d8d61bad3679b0d256bd9520b9a957ad52faabaa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Silva?=
<123550+andresilva@users.noreply.github.com>
Date: Mon, 14 Jun 2021 21:41:02 +0100
Subject: [PATCH] implement dispute participation subsystem (#3234)
* implement dispute participation subsystem
* guide: minor fix in dispute participation
* Update node/core/dispute-participation/src/lib.rs
Co-authored-by: Andronik Ordian <write@reusable.software>
* dispute: add comments to participation logic
* dispute-coordinator: fix test compilation
* implementers-guide: update dispute participation
* dispute-participation: add error for missing validation code
* dispute-participation: add tests
* Update node/core/dispute-participation/src/lib.rs
Co-authored-by: Robert Habermeier <rphmeier@gmail.com>
* guide: update overseer protocol dispute participation message
* dispute-participation: remove duplication in tests
Co-authored-by: Andronik Ordian <write@reusable.software>
Co-authored-by: Robert Habermeier <rphmeier@gmail.com>
---
polkadot/Cargo.lock | 16 +
polkadot/Cargo.toml | 1 +
.../node/core/dispute-coordinator/src/lib.rs | 4 +-
.../core/dispute-coordinator/src/tests.rs | 4 +-
.../core/dispute-participation/Cargo.toml | 20 +
.../core/dispute-participation/src/lib.rs | 372 +++++++++++++++
.../core/dispute-participation/src/tests.rs | 425 ++++++++++++++++++
polkadot/node/subsystem/src/messages.rs | 6 +-
.../node/disputes/dispute-participation.md | 13 +-
.../src/types/overseer-protocol.md | 4 +-
10 files changed, 852 insertions(+), 13 deletions(-)
create mode 100644 polkadot/node/core/dispute-participation/Cargo.toml
create mode 100644 polkadot/node/core/dispute-participation/src/lib.rs
create mode 100644 polkadot/node/core/dispute-participation/src/tests.rs
diff --git a/polkadot/Cargo.lock b/polkadot/Cargo.lock
index 7df9fe6885e..deaebf56c71 100644
--- a/polkadot/Cargo.lock
+++ b/polkadot/Cargo.lock
@@ -6117,6 +6117,22 @@ dependencies = [
"tracing",
]
+[[package]]
+name = "polkadot-node-core-dispute-participation"
+version = "0.1.0"
+dependencies = [
+ "assert_matches",
+ "futures 0.3.15",
+ "parity-scale-codec",
+ "polkadot-node-primitives",
+ "polkadot-node-subsystem",
+ "polkadot-node-subsystem-test-helpers",
+ "polkadot-primitives",
+ "sp-core",
+ "thiserror",
+ "tracing",
+]
+
[[package]]
name = "polkadot-node-core-parachains-inherent"
version = "0.1.0"
diff --git a/polkadot/Cargo.toml b/polkadot/Cargo.toml
index dd4983b7535..4b55f0bf815 100644
--- a/polkadot/Cargo.toml
+++ b/polkadot/Cargo.toml
@@ -49,6 +49,7 @@ members = [
"node/core/candidate-validation",
"node/core/chain-api",
"node/core/dispute-coordinator",
+ "node/core/dispute-participation",
"node/core/parachains-inherent",
"node/core/provisioner",
"node/core/pvf",
diff --git a/polkadot/node/core/dispute-coordinator/src/lib.rs b/polkadot/node/core/dispute-coordinator/src/lib.rs
index 618d312758c..9d4daeeba7e 100644
--- a/polkadot/node/core/dispute-coordinator/src/lib.rs
+++ b/polkadot/node/core/dispute-coordinator/src/lib.rs
@@ -483,13 +483,11 @@ async fn handle_import_statements(
|active| active.insert(session, candidate_hash),
)?;
- let voted_indices = votes.voted_indices();
-
ctx.send_message(DisputeParticipationMessage::Participate {
candidate_hash,
candidate_receipt,
session,
- voted_indices,
+ n_validators: n_validators as u32,
}.into()).await;
}
diff --git a/polkadot/node/core/dispute-coordinator/src/tests.rs b/polkadot/node/core/dispute-coordinator/src/tests.rs
index 831e703c826..dc8c93de968 100644
--- a/polkadot/node/core/dispute-coordinator/src/tests.rs
+++ b/polkadot/node/core/dispute-coordinator/src/tests.rs
@@ -279,12 +279,12 @@ fn conflicting_votes_lead_to_dispute_participation() {
candidate_hash: c_hash,
candidate_receipt: c_receipt,
session: s,
- voted_indices,
+ n_validators,
}) => {
assert_eq!(c_hash, candidate_hash);
assert_eq!(c_receipt, candidate_receipt);
assert_eq!(s, session);
- assert_eq!(voted_indices, vec![ValidatorIndex(0), ValidatorIndex(1)]);
+ assert_eq!(n_validators, test_state.validators.len() as u32);
}
);
diff --git a/polkadot/node/core/dispute-participation/Cargo.toml b/polkadot/node/core/dispute-participation/Cargo.toml
new file mode 100644
index 00000000000..7de5c195b6d
--- /dev/null
+++ b/polkadot/node/core/dispute-participation/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "polkadot-node-core-dispute-participation"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+
+[dependencies]
+futures = "0.3.12"
+thiserror = "1.0.23"
+tracing = "0.1.26"
+
+polkadot-node-primitives = { path = "../../primitives" }
+polkadot-node-subsystem = { path = "../../subsystem" }
+polkadot-primitives = { path = "../../../primitives" }
+
+[dev-dependencies]
+assert_matches = "1.5.0"
+parity-scale-codec = "2.0.0"
+polkadot-node-subsystem-test-helpers = { path = "../../subsystem-test-helpers"}
+sp-core = { git = "https://github.com/paritytech/substrate", branch = "master" }
diff --git a/polkadot/node/core/dispute-participation/src/lib.rs b/polkadot/node/core/dispute-participation/src/lib.rs
new file mode 100644
index 00000000000..19bc56a020a
--- /dev/null
+++ b/polkadot/node/core/dispute-participation/src/lib.rs
@@ -0,0 +1,372 @@
+// Copyright 2021 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/>.
+
+//! Implements the dispute participation subsystem.
+//!
+//! This subsystem is responsible for actually participating in disputes: when
+//! notified of a dispute, we recover the candidate data, validate the
+//! candidate, and cast our vote in the dispute.
+
+use futures::channel::oneshot;
+use futures::prelude::*;
+
+use polkadot_node_primitives::ValidationResult;
+use polkadot_node_subsystem::{
+ errors::{RecoveryError, RuntimeApiError},
+ messages::{
+ AllMessages, AvailabilityRecoveryMessage, AvailabilityStoreMessage,
+ CandidateValidationMessage, DisputeCoordinatorMessage, DisputeParticipationMessage,
+ RuntimeApiMessage, RuntimeApiRequest,
+ },
+ ActiveLeavesUpdate, FromOverseer, OverseerSignal, SpawnedSubsystem, Subsystem,
+ SubsystemContext, SubsystemError,
+};
+use polkadot_primitives::v1::{BlockNumber, CandidateHash, CandidateReceipt, Hash, SessionIndex};
+
+#[cfg(test)]
+mod tests;
+
+const LOG_TARGET: &str = "parachain::dispute-participation";
+
+struct State {
+ recent_block: Option<(BlockNumber, Hash)>,
+}
+
+/// An implementation of the dispute participation subsystem.
+pub struct DisputeParticipationSubsystem;
+
+impl DisputeParticipationSubsystem {
+ /// Create a new instance of the subsystem.
+ pub fn new() -> Self {
+ DisputeParticipationSubsystem
+ }
+}
+
+impl<Context> Subsystem<Context> for DisputeParticipationSubsystem
+where
+ Context: SubsystemContext<Message = DisputeParticipationMessage>,
+{
+ fn start(self, ctx: Context) -> SpawnedSubsystem {
+ let future = run(ctx).map(|_| Ok(())).boxed();
+
+ SpawnedSubsystem {
+ name: "dispute-participation-subsystem",
+ future,
+ }
+ }
+}
+
+#[derive(Debug, thiserror::Error)]
+#[allow(missing_docs)]
+pub enum Error {
+ #[error(transparent)]
+ RuntimeApi(#[from] RuntimeApiError),
+
+ #[error(transparent)]
+ Subsystem(#[from] SubsystemError),
+
+ #[error(transparent)]
+ Oneshot(#[from] oneshot::Canceled),
+
+ #[error(transparent)]
+ Participation(#[from] ParticipationError),
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum ParticipationError {
+ #[error("Missing recent block state to participate in dispute")]
+ MissingRecentBlockState,
+ #[error("Failed to recover available data for candidate {0}")]
+ MissingAvailableData(CandidateHash),
+ #[error("Failed to recover validation code for candidate {0}")]
+ MissingValidationCode(CandidateHash),
+}
+
+impl Error {
+ fn trace(&self) {
+ match self {
+ // don't spam the log with spurious errors
+ Self::RuntimeApi(_) | Self::Oneshot(_) => {
+ tracing::debug!(target: LOG_TARGET, err = ?self)
+ }
+ // it's worth reporting otherwise
+ _ => tracing::warn!(target: LOG_TARGET, err = ?self),
+ }
+ }
+}
+
+async fn run<Context>(mut ctx: Context)
+where
+ Context: SubsystemContext<Message = DisputeParticipationMessage>,
+{
+ let mut state = State { recent_block: None };
+
+ loop {
+ match ctx.recv().await {
+ Err(_) => return,
+ Ok(FromOverseer::Signal(OverseerSignal::Conclude)) => {
+ tracing::info!(target: LOG_TARGET, "Received `Conclude` signal, exiting");
+ return;
+ }
+ Ok(FromOverseer::Signal(OverseerSignal::BlockFinalized(_, _))) => {}
+ Ok(FromOverseer::Signal(OverseerSignal::ActiveLeaves(update))) => {
+ update_state(&mut state, update);
+ }
+ Ok(FromOverseer::Communication { msg }) => {
+ if let Err(err) = handle_incoming(&mut ctx, &mut state, msg).await {
+ err.trace();
+ if let Error::Subsystem(SubsystemError::Context(_)) = err {
+ return;
+ }
+ }
+ }
+ }
+ }
+}
+
+fn update_state(state: &mut State, update: ActiveLeavesUpdate) {
+ for active in update.activated {
+ if state.recent_block.map_or(true, |s| active.number > s.0) {
+ state.recent_block = Some((active.number, active.hash));
+ }
+ }
+}
+
+async fn handle_incoming(
+ ctx: &mut impl SubsystemContext,
+ state: &mut State,
+ message: DisputeParticipationMessage,
+) -> Result<(), Error> {
+ match message {
+ DisputeParticipationMessage::Participate {
+ candidate_hash,
+ candidate_receipt,
+ session,
+ n_validators,
+ } => {
+ if let Some((_, block_hash)) = state.recent_block {
+ participate(
+ ctx,
+ block_hash,
+ candidate_hash,
+ candidate_receipt,
+ session,
+ n_validators,
+ )
+ .await
+ } else {
+ return Err(ParticipationError::MissingRecentBlockState.into());
+ }
+ }
+ }
+}
+
+async fn participate(
+ ctx: &mut impl SubsystemContext,
+ block_hash: Hash,
+ candidate_hash: CandidateHash,
+ candidate_receipt: CandidateReceipt,
+ session: SessionIndex,
+ n_validators: u32,
+) -> Result<(), Error> {
+ let (recover_available_data_tx, recover_available_data_rx) = oneshot::channel();
+ let (code_tx, code_rx) = oneshot::channel();
+ let (store_available_data_tx, store_available_data_rx) = oneshot::channel();
+ let (validation_tx, validation_rx) = oneshot::channel();
+
+ // in order to validate a candidate we need to start by recovering the
+ // available data
+ ctx.send_message(
+ AvailabilityRecoveryMessage::RecoverAvailableData(
+ candidate_receipt.clone(),
+ session,
+ None,
+ recover_available_data_tx,
+ )
+ .into(),
+ )
+ .await;
+
+ let available_data = match recover_available_data_rx.await? {
+ Ok(data) => data,
+ Err(RecoveryError::Invalid) => {
+ // the available data was recovered but it is invalid, therefore we'll
+ // vote negatively for the candidate dispute
+ cast_invalid_vote(ctx, candidate_hash, candidate_receipt, session).await;
+ return Ok(());
+ }
+ Err(RecoveryError::Unavailable) => {
+ return Err(ParticipationError::MissingAvailableData(candidate_hash).into());
+ }
+ };
+
+ // we also need to fetch the validation code which we can reference by its
+ // hash as taken from the candidate descriptor
+ ctx.send_message(
+ RuntimeApiMessage::Request(
+ block_hash,
+ RuntimeApiRequest::ValidationCodeByHash(
+ candidate_receipt.descriptor.validation_code_hash,
+ code_tx,
+ ),
+ )
+ .into(),
+ )
+ .await;
+
+ let validation_code = match code_rx.await?? {
+ Some(code) => code,
+ None => {
+ tracing::warn!(
+ target: LOG_TARGET,
+ "Validation code unavailable for code hash {:?} in the state of block {:?}",
+ candidate_receipt.descriptor.validation_code_hash,
+ block_hash,
+ );
+
+ return Err(ParticipationError::MissingValidationCode(candidate_hash).into());
+ }
+ };
+
+ // we dispatch a request to store the available data for the candidate. we
+ // want to maximize data availability for other potential checkers involved
+ // in the dispute
+ ctx.send_message(
+ AvailabilityStoreMessage::StoreAvailableData(
+ candidate_hash,
+ None,
+ n_validators,
+ available_data.clone(),
+ store_available_data_tx,
+ )
+ .into(),
+ )
+ .await;
+
+ match store_available_data_rx.await? {
+ Err(_) => {
+ tracing::warn!(
+ target: LOG_TARGET,
+ "Failed to store available data for candidate {:?}",
+ candidate_hash,
+ );
+ }
+ Ok(()) => {}
+ }
+
+ // we issue a request to validate the candidate with the provided exhaustive
+ // parameters
+ ctx.send_message(
+ CandidateValidationMessage::ValidateFromExhaustive(
+ available_data.validation_data,
+ validation_code,
+ candidate_receipt.descriptor.clone(),
+ available_data.pov,
+ validation_tx,
+ )
+ .into(),
+ )
+ .await;
+
+ // we cast votes (either positive or negative) depending on the outcome of
+ // the validation and if valid, whether the commitments hash matches
+ match validation_rx.await? {
+ Err(err) => {
+ tracing::warn!(
+ target: LOG_TARGET,
+ "Candidate {:?} validation failed with: {:?}",
+ candidate_receipt.hash(),
+ err,
+ );
+
+ cast_invalid_vote(ctx, candidate_hash, candidate_receipt, session).await;
+ }
+ Ok(ValidationResult::Invalid(invalid)) => {
+ tracing::warn!(
+ target: LOG_TARGET,
+ "Candidate {:?} considered invalid: {:?}",
+ candidate_hash,
+ invalid,
+ );
+
+ cast_invalid_vote(ctx, candidate_hash, candidate_receipt, session).await;
+ }
+ Ok(ValidationResult::Valid(commitments, _)) => {
+ if commitments.hash() != candidate_receipt.commitments_hash {
+ tracing::warn!(
+ target: LOG_TARGET,
+ expected = ?candidate_receipt.commitments_hash,
+ got = ?commitments.hash(),
+ "Candidate is valid but commitments hash doesn't match",
+ );
+
+ cast_invalid_vote(ctx, candidate_hash, candidate_receipt, session).await;
+ } else {
+ cast_valid_vote(ctx, candidate_hash, candidate_receipt, session).await;
+ }
+ }
+ }
+
+ Ok(())
+}
+
+async fn cast_valid_vote(
+ ctx: &mut impl SubsystemContext,
+ candidate_hash: CandidateHash,
+ candidate_receipt: CandidateReceipt,
+ session: SessionIndex,
+) {
+ tracing::info!(
+ target: LOG_TARGET,
+ "Casting valid vote in dispute for candidate {:?}",
+ candidate_hash,
+ );
+
+ issue_local_statement(ctx, candidate_hash, candidate_receipt, session, true).await;
+}
+
+async fn cast_invalid_vote(
+ ctx: &mut impl SubsystemContext,
+ candidate_hash: CandidateHash,
+ candidate_receipt: CandidateReceipt,
+ session: SessionIndex,
+) {
+ tracing::info!(
+ target: LOG_TARGET,
+ "Casting invalid vote in dispute for candidate {:?}",
+ candidate_hash,
+ );
+
+ issue_local_statement(ctx, candidate_hash, candidate_receipt, session, false).await;
+}
+
+async fn issue_local_statement(
+ ctx: &mut impl SubsystemContext,
+ candidate_hash: CandidateHash,
+ candidate_receipt: CandidateReceipt,
+ session: SessionIndex,
+ valid: bool,
+) {
+ ctx.send_message(AllMessages::DisputeCoordinator(
+ DisputeCoordinatorMessage::IssueLocalStatement(
+ session,
+ candidate_hash,
+ candidate_receipt,
+ valid,
+ ),
+ ))
+ .await
+}
diff --git a/polkadot/node/core/dispute-participation/src/tests.rs b/polkadot/node/core/dispute-participation/src/tests.rs
new file mode 100644
index 00000000000..2b086c43d17
--- /dev/null
+++ b/polkadot/node/core/dispute-participation/src/tests.rs
@@ -0,0 +1,425 @@
+// Copyright 2021 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/>.
+
+use assert_matches::assert_matches;
+use futures::future::{self, BoxFuture};
+use std::sync::Arc;
+
+use sp_core::testing::TaskExecutor;
+
+use super::*;
+use parity_scale_codec::Encode;
+use polkadot_node_primitives::{AvailableData, BlockData, InvalidCandidate, PoV};
+use polkadot_node_subsystem::{
+ jaeger, messages::ValidationFailed, ActivatedLeaf, ActiveLeavesUpdate, LeafStatus,
+};
+use polkadot_node_subsystem_test_helpers::{make_subsystem_context, TestSubsystemContextHandle};
+use polkadot_primitives::v1::{BlakeTwo256, CandidateCommitments, HashT, Header, ValidationCode};
+
+type VirtualOverseer = TestSubsystemContextHandle<DisputeParticipationMessage>;
+
+fn test_harness<F>(test: F)
+where
+ F: FnOnce(VirtualOverseer) -> BoxFuture<'static, VirtualOverseer>,
+{
+ let (ctx, ctx_handle) = make_subsystem_context(TaskExecutor::new());
+
+ let subsystem = DisputeParticipationSubsystem::new();
+ let spawned_subsystem = subsystem.start(ctx);
+ let test_future = test(ctx_handle);
+
+ let (subsystem_result, _) =
+ futures::executor::block_on(future::join(spawned_subsystem.future, async move {
+ let mut ctx_handle = test_future.await;
+ ctx_handle
+ .send(FromOverseer::Signal(OverseerSignal::Conclude))
+ .await;
+
+ // no further request is received by the overseer which means that
+ // no further attempt to participate was made
+ assert!(ctx_handle.try_recv().await.is_none());
+ }));
+
+ subsystem_result.unwrap();
+}
+
+async fn activate_leaf(virtual_overseer: &mut VirtualOverseer, block_number: BlockNumber) {
+ let block_header = Header {
+ parent_hash: BlakeTwo256::hash(&block_number.encode()),
+ number: block_number,
+ digest: Default::default(),
+ state_root: Default::default(),
+ extrinsics_root: Default::default(),
+ };
+
+ let block_hash = block_header.hash();
+
+ virtual_overseer
+ .send(FromOverseer::Signal(OverseerSignal::ActiveLeaves(
+ ActiveLeavesUpdate::start_work(ActivatedLeaf {
+ hash: block_hash,
+ span: Arc::new(jaeger::Span::Disabled),
+ number: block_number,
+ status: LeafStatus::Fresh,
+ }),
+ )))
+ .await;
+}
+
+async fn participate(virtual_overseer: &mut VirtualOverseer) {
+ let commitments = CandidateCommitments::default();
+ let candidate_receipt = {
+ let mut receipt = CandidateReceipt::default();
+ receipt.commitments_hash = commitments.hash();
+ receipt
+ };
+ let candidate_hash = candidate_receipt.hash();
+ let session = 1;
+ let n_validators = 10;
+
+ virtual_overseer
+ .send(FromOverseer::Communication {
+ msg: DisputeParticipationMessage::Participate {
+ candidate_hash,
+ candidate_receipt: candidate_receipt.clone(),
+ session,
+ n_validators,
+ },
+ })
+ .await;
+}
+
+async fn recover_available_data(virtual_overseer: &mut VirtualOverseer) {
+ let pov_block = PoV {
+ block_data: BlockData(Vec::new()),
+ };
+
+ let available_data = AvailableData {
+ pov: Arc::new(pov_block),
+ validation_data: Default::default(),
+ };
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::AvailabilityRecovery(
+ AvailabilityRecoveryMessage::RecoverAvailableData(_, _, _, tx)
+ ) => {
+ tx.send(Ok(available_data)).unwrap();
+ },
+ "overseer did not receive recover available data message",
+ );
+}
+
+async fn fetch_validation_code(virtual_overseer: &mut VirtualOverseer) {
+ let validation_code = ValidationCode(Vec::new());
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+ _,
+ RuntimeApiRequest::ValidationCodeByHash(
+ _,
+ tx,
+ )
+ )) => {
+ tx.send(Ok(Some(validation_code))).unwrap();
+ },
+ "overseer did not receive runtime api request for validation code",
+ );
+}
+
+async fn store_available_data(virtual_overseer: &mut VirtualOverseer, success: bool) {
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::AvailabilityStore(AvailabilityStoreMessage::StoreAvailableData(
+ _,
+ _,
+ _,
+ _,
+ tx,
+ )) => {
+ if success {
+ tx.send(Ok(())).unwrap();
+ } else {
+ tx.send(Err(())).unwrap();
+ }
+ },
+ "overseer did not receive store available data request",
+ );
+}
+
+#[test]
+fn cannot_participate_when_recent_block_state_is_missing() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ participate(&mut virtual_overseer).await;
+
+ virtual_overseer
+ })
+ });
+
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+
+ // after activating at least one leaf the recent block
+ // state should be available which should lead to trying
+ // to participate by first trying to recover the available
+ // data
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::AvailabilityRecovery(
+ AvailabilityRecoveryMessage::RecoverAvailableData(..)
+ ),
+ "overseer did not receive recover available data message",
+ );
+
+ virtual_overseer
+ })
+ });
+}
+
+#[test]
+fn cannot_participate_if_cannot_recover_available_data() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::AvailabilityRecovery(
+ AvailabilityRecoveryMessage::RecoverAvailableData(_, _, _, tx)
+ ) => {
+ tx.send(Err(RecoveryError::Unavailable)).unwrap();
+ },
+ "overseer did not receive recover available data message",
+ );
+
+ virtual_overseer
+ })
+ });
+}
+
+#[test]
+fn cannot_participate_if_cannot_recover_validation_code() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+ recover_available_data(&mut virtual_overseer).await;
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+ _,
+ RuntimeApiRequest::ValidationCodeByHash(
+ _,
+ tx,
+ )
+ )) => {
+ tx.send(Ok(None)).unwrap();
+ },
+ "overseer did not receive runtime api request for validation code",
+ );
+
+ virtual_overseer
+ })
+ });
+}
+
+#[test]
+fn cast_invalid_vote_if_available_data_is_invalid() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::AvailabilityRecovery(
+ AvailabilityRecoveryMessage::RecoverAvailableData(_, _, _, tx)
+ ) => {
+ tx.send(Err(RecoveryError::Invalid)).unwrap();
+ },
+ "overseer did not receive recover available data message",
+ );
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::DisputeCoordinator(DisputeCoordinatorMessage::IssueLocalStatement(
+ _,
+ _,
+ _,
+ false,
+ )),
+ "overseer did not receive issue local statement message",
+ );
+
+ virtual_overseer
+ })
+ });
+}
+
+#[test]
+fn cast_invalid_vote_if_validation_fails_or_is_invalid() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+ recover_available_data(&mut virtual_overseer).await;
+ fetch_validation_code(&mut virtual_overseer).await;
+ store_available_data(&mut virtual_overseer, true).await;
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::CandidateValidation(
+ CandidateValidationMessage::ValidateFromExhaustive(_, _, _, _, tx)
+ ) => {
+ tx.send(Ok(ValidationResult::Invalid(InvalidCandidate::Timeout))).unwrap();
+ },
+ "overseer did not receive candidate validation message",
+ );
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::DisputeCoordinator(DisputeCoordinatorMessage::IssueLocalStatement(
+ _,
+ _,
+ _,
+ false,
+ )),
+ "overseer did not receive issue local statement message",
+ );
+
+ virtual_overseer
+ })
+ });
+}
+
+#[test]
+fn cast_invalid_vote_if_validation_passes_but_commitments_dont_match() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+ recover_available_data(&mut virtual_overseer).await;
+ fetch_validation_code(&mut virtual_overseer).await;
+ store_available_data(&mut virtual_overseer, true).await;
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::CandidateValidation(
+ CandidateValidationMessage::ValidateFromExhaustive(_, _, _, _, tx)
+ ) => {
+ let mut commitments = CandidateCommitments::default();
+ // this should lead to a commitments hash mismatch
+ commitments.processed_downward_messages = 42;
+
+ tx.send(Ok(ValidationResult::Valid(commitments, Default::default()))).unwrap();
+ },
+ "overseer did not receive candidate validation message",
+ );
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::DisputeCoordinator(DisputeCoordinatorMessage::IssueLocalStatement(
+ _,
+ _,
+ _,
+ false,
+ )),
+ "overseer did not receive issue local statement message",
+ );
+
+ virtual_overseer
+ })
+ });
+}
+
+#[test]
+fn cast_valid_vote_if_validation_passes() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+ recover_available_data(&mut virtual_overseer).await;
+ fetch_validation_code(&mut virtual_overseer).await;
+ store_available_data(&mut virtual_overseer, true).await;
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::CandidateValidation(
+ CandidateValidationMessage::ValidateFromExhaustive(_, _, _, _, tx)
+ ) => {
+ tx.send(Ok(ValidationResult::Valid(Default::default(), Default::default()))).unwrap();
+ },
+ "overseer did not receive candidate validation message",
+ );
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::DisputeCoordinator(DisputeCoordinatorMessage::IssueLocalStatement(
+ _,
+ _,
+ _,
+ true,
+ )),
+ "overseer did not receive issue local statement message",
+ );
+
+ virtual_overseer
+ })
+ });
+}
+
+#[test]
+fn failure_to_store_available_data_does_not_preclude_participation() {
+ test_harness(|mut virtual_overseer| {
+ Box::pin(async move {
+ activate_leaf(&mut virtual_overseer, 10).await;
+ participate(&mut virtual_overseer).await;
+ recover_available_data(&mut virtual_overseer).await;
+ fetch_validation_code(&mut virtual_overseer).await;
+ // the store available data request should fail
+ store_available_data(&mut virtual_overseer, false).await;
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::CandidateValidation(
+ CandidateValidationMessage::ValidateFromExhaustive(_, _, _, _, tx)
+ ) => {
+ tx.send(Err(ValidationFailed("fail".to_string()))).unwrap();
+ },
+ "overseer did not receive candidate validation message",
+ );
+
+ assert_matches!(
+ virtual_overseer.recv().await,
+ AllMessages::DisputeCoordinator(DisputeCoordinatorMessage::IssueLocalStatement(
+ _,
+ _,
+ _,
+ false,
+ )),
+ "overseer did not receive issue local statement message",
+ );
+
+ virtual_overseer
+ })
+ });
+}
diff --git a/polkadot/node/subsystem/src/messages.rs b/polkadot/node/subsystem/src/messages.rs
index cf5e75d7c54..f8ae3dead6f 100644
--- a/polkadot/node/subsystem/src/messages.rs
+++ b/polkadot/node/subsystem/src/messages.rs
@@ -250,9 +250,9 @@ pub enum DisputeParticipationMessage {
candidate_receipt: CandidateReceipt,
/// The session the candidate appears in.
session: SessionIndex,
- /// The indices of validators who have already voted on this candidate.
- voted_indices: Vec<ValidatorIndex>,
- }
+ /// The number of validators in the session.
+ n_validators: u32,
+ },
}
/// Messages received by the network bridge subsystem.
diff --git a/polkadot/roadmap/implementers-guide/src/node/disputes/dispute-participation.md b/polkadot/roadmap/implementers-guide/src/node/disputes/dispute-participation.md
index c901d4d1dbc..3eb11da1a0b 100644
--- a/polkadot/roadmap/implementers-guide/src/node/disputes/dispute-participation.md
+++ b/polkadot/roadmap/implementers-guide/src/node/disputes/dispute-participation.md
@@ -16,9 +16,17 @@ Output:
## Functionality
+In-memory state:
+
+```rust
+struct State {
+ recent_block_hash: Option<(BlockNumber, Hash)>
+}
+```
+
### On `OverseerSignal::ActiveLeavesUpdate`
-Do nothing.
+Update `recent_block` in in-memory state according to the highest observed active leaf.
### On `OverseerSignal::BlockFinalized`
@@ -34,8 +42,7 @@ Conclude.
* Issue an [`AvailabilityRecoveryMessage::RecoverAvailableData`][AvailabilityRecoveryMessage]
* If the result is `Unavailable`, return.
* If the result is `Invalid`, [cast invalid votes](#cast-votes) and return.
-* Fetch the block number of `candidate_receipt.descriptor.relay_parent` using a [`ChainApiMessage::BlockNumber`][ChainApiMessage].
-* If the data is recovered, dispatch a [`RuntimeApiMessage::ValidationCodeByHash`][RuntimeApiMessage] with the parameters `(candidate_receipt.descriptor.validation_code_hash)`.
+* If the data is recovered, dispatch a [`RuntimeApiMessage::ValidationCodeByHash`][RuntimeApiMessage] with the parameters `(candidate_receipt.descriptor.validation_code_hash)` at `state.recent_block.hash`.
* Dispatch a [`AvailabilityStoreMessage::StoreAvailableData`][AvailabilityStoreMessage] with the data.
* If the code is not fetched from the chain, return. This should be impossible with correct relay chain configuration, at least if chain synchronization is working correctly.
* Dispatch a [`CandidateValidationMessage::ValidateFromExhaustive`][CandidateValidationMessage] with the available data and the validation code.
diff --git a/polkadot/roadmap/implementers-guide/src/types/overseer-protocol.md b/polkadot/roadmap/implementers-guide/src/types/overseer-protocol.md
index 84dd8f7474e..c2b0cac8122 100644
--- a/polkadot/roadmap/implementers-guide/src/types/overseer-protocol.md
+++ b/polkadot/roadmap/implementers-guide/src/types/overseer-protocol.md
@@ -438,8 +438,8 @@ enum DisputeParticipationMessage {
candidate_receipt: CandidateReceipt,
/// The session the candidate appears in.
session: SessionIndex,
- /// The indices of validators who have already voted on this candidate.
- voted_indices: Vec<ValidatorIndex>,
+ /// The number of validators in the session.
+ n_validators: u32,
}
}
```
--
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