Dispute Coordinator Subsystem (#3150)

* skeleton for dispute-coordinator * add coordinator and participation message types * begin dispute-coordinator DB * functions for loading * implement strongly-typed DB transaction * add some tests for DB transaction * core logic for pruning * guide: update candidate-votes key for coordinator * update candidate-votes key * use big-endian encoding for session, and implement upper bound generator * finish implementing pruning * add a test for note_current_session * define state of the subsystem itself * barebones subsystem definition * control flow * more control flow * implement session-updating logic * trace * control flow for message handling * Update node/core/dispute-coordinator/src/lib.rs Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com> * Update node/subsystem/src/messages.rs Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com> * some more control flow * guide: remove overlay * more control flow * implement some DB getters * make progress on importing statements * add SignedDisputeStatement struct * move ApprovalVote to shared primitives * add a signing-payload API to explicit dispute statements * add signing-payload to CompactStatement * add relay-parent hash to seconded/valid dispute variatns * correct import * type-safe wrapper around dispute statements * use checked dispute statement in message type * extract rolling session window cache to subsystem-util * extract session window tests * approval-voting: use rolling session info cache * reduce dispute window to match runtime in practice * add byzantine_threshold and supermajority_threshold utilities to primitives * integrate rolling session window * Add PartialOrd to CandidateHash * add Ord to CandidateHash * implement active dispute update * add dispute messages to AllMessages * add dispute stubs to overseer * inform dispute participation to participate * implement issue_local_statement * implement `determine_undisputed_chain` * fix warnings * test harness for dispute coordinator tests * add more helpers to test harness * add some more helpers * some tests for dispute coordinator * ignore wrong validator indices * test finality voting rule constraint * add more tests * add variants to network bridge * fix test compilation * remove most dispute coordinator functionality as of #3222 we can do most of the work within the approval voting subsystem * Revert "remove most dispute coordinator functionality" This reverts commit 9cd615e8eb6ca0b382cbaff525d813e753d6004e. * Use thiserror Co-authored-by: Bernhard Schuster <bernhard@ahoi.io> * Update node/core/dispute-coordinator/src/lib.rs Co-authored-by: Bernhard Schuster <bernhard@ahoi.io> * extract tests to separate module * address nit * adjust run_iteration API Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com> Co-authored-by: Bernhard Schuster <bernhard@ahoi.io>
2026-04-26 13:27:57 +00:00 · 2021-06-13 13:35:18 +02:00
parent 7f344df160
commit 5bc2b2779d
22 changed files with 3070 additions and 594 deletions
@@ -98,10 +98,6 @@ pub struct IndirectAssignmentCert {
 	pub cert: AssignmentCert,
 }

-/// A vote of approval on a candidate.
-#[derive(Debug, Clone, Encode, Decode)]
-pub struct ApprovalVote(pub CandidateHash);
-
 /// A signed approval vote which references the candidate indirectly via the block.
 ///
 /// In practice, we have a look-up from block hash and candidate index to candidate hash,
@@ -22,18 +22,28 @@

 #![deny(missing_docs)]

+use std::convert::TryInto;
 use std::pin::Pin;

 use serde::{Serialize, Deserialize};
 use futures::Future;
 use parity_scale_codec::{Decode, Encode};
+use sp_keystore::{CryptoStore, SyncCryptoStorePtr, Error as KeystoreError};
+use sp_application_crypto::AppKey;

 pub use sp_core::traits::SpawnNamed;
 pub use sp_consensus_babe::{
 	Epoch as BabeEpoch, BabeEpochConfiguration, AllowedSlots as BabeAllowedSlots,
 };

-use polkadot_primitives::v1::{BlakeTwo256, CandidateCommitments, CandidateHash, CollatorPair, CommittedCandidateReceipt, CompactStatement, EncodeAs, Hash, HashT, HeadData, Id as ParaId, OutboundHrmpMessage, PersistedValidationData, Signed, UncheckedSigned, UpwardMessage, ValidationCode, ValidatorIndex};
+use polkadot_primitives::v1::{
+	BlakeTwo256, CandidateCommitments, CandidateHash, CollatorPair, CommittedCandidateReceipt,
+	CompactStatement, EncodeAs, Hash, HashT, HeadData, Id as ParaId, OutboundHrmpMessage,
+	PersistedValidationData, Signed, UncheckedSigned, UpwardMessage, ValidationCode,
+	ValidatorIndex, ValidatorSignature, ValidDisputeStatementKind, InvalidDisputeStatementKind,
+	CandidateReceipt, ValidatorId, SessionIndex, DisputeStatement,
+};
+
 pub use polkadot_parachain::primitives::BlockData;

 pub mod approval;
@@ -273,3 +283,125 @@ pub fn maybe_compress_pov(pov: PoV) -> PoV {
 	let pov = PoV { block_data: BlockData(raw) };
 	pov
 }
+
+/// Tracked votes on candidates, for the purposes of dispute resolution.
+#[derive(Debug, Clone)]
+pub struct CandidateVotes {
+	/// The receipt of the candidate itself.
+	pub candidate_receipt: CandidateReceipt,
+	/// Votes of validity, sorted by validator index.
+	pub valid: Vec<(ValidDisputeStatementKind, ValidatorIndex, ValidatorSignature)>,
+	/// Votes of invalidity, sorted by validator index.
+	pub invalid: Vec<(InvalidDisputeStatementKind, ValidatorIndex, ValidatorSignature)>,
+}
+
+impl CandidateVotes {
+	/// Get the set of all validators who have votes in the set, ascending.
+	pub fn voted_indices(&self) -> Vec<ValidatorIndex> {
+		let mut v: Vec<_> = self.valid.iter().map(|x| x.1).chain(
+			self.invalid.iter().map(|x| x.1)
+		).collect();
+
+		v.sort();
+		v.dedup();
+
+		v
+	}
+}
+
+
+/// A checked dispute statement from an associated validator.
+#[derive(Debug, Clone)]
+pub struct SignedDisputeStatement {
+	dispute_statement: DisputeStatement,
+	candidate_hash: CandidateHash,
+	validator_public: ValidatorId,
+	validator_signature: ValidatorSignature,
+	session_index: SessionIndex,
+}
+
+impl SignedDisputeStatement {
+	/// Create a new `SignedDisputeStatement`, which is only possible by checking the signature.
+	pub fn new_checked(
+		dispute_statement: DisputeStatement,
+		candidate_hash: CandidateHash,
+		session_index: SessionIndex,
+		validator_public: ValidatorId,
+		validator_signature: ValidatorSignature,
+	) -> Result<Self, ()> {
+		dispute_statement.check_signature(
+			&validator_public,
+			candidate_hash,
+			session_index,
+			&validator_signature,
+		).map(|_| SignedDisputeStatement {
+			dispute_statement,
+			candidate_hash,
+			validator_public,
+			validator_signature,
+			session_index,
+		})
+	}
+
+	/// Sign this statement with the given keystore and key. Pass `valid = true` to
+	/// indicate validity of the candidate, and `valid = false` to indicate invalidity.
+	pub async fn sign_explicit(
+		keystore: &SyncCryptoStorePtr,
+		valid: bool,
+		candidate_hash: CandidateHash,
+		session_index: SessionIndex,
+		validator_public: ValidatorId,
+	) -> Result<Option<Self>, KeystoreError> {
+		let dispute_statement = if valid {
+			DisputeStatement::Valid(ValidDisputeStatementKind::Explicit)
+		} else {
+			DisputeStatement::Invalid(InvalidDisputeStatementKind::Explicit)
+		};
+
+		let data = dispute_statement.payload_data(candidate_hash, session_index);
+		let signature = CryptoStore::sign_with(
+			&**keystore,
+			ValidatorId::ID,
+			&validator_public.clone().into(),
+			&data,
+		).await?;
+
+		let signature = match signature {
+			Some(sig) => sig.try_into().map_err(|_| KeystoreError::KeyNotSupported(ValidatorId::ID))?,
+			None => return Ok(None),
+		};
+
+		Ok(Some(Self {
+			dispute_statement,
+			candidate_hash,
+			validator_public,
+			validator_signature: signature,
+			session_index,
+		}))
+	}
+
+	/// Access the underlying dispute statement
+	pub fn statement(&self) -> &DisputeStatement {
+		&self.dispute_statement
+	}
+
+	/// Access the underlying candidate hash.
+	pub fn candidate_hash(&self) -> &CandidateHash {
+		&self.candidate_hash
+	}
+
+	/// Access the underlying validator public key.
+	pub fn validator_public(&self) -> &ValidatorId {
+		&self.validator_public
+	}
+
+	/// Access the underlying validator signature.
+	pub fn validator_signature(&self) -> &ValidatorSignature {
+		&self.validator_signature
+	}
+
+	/// Access the underlying session index.
+	pub fn session_index(&self) -> SessionIndex {
+		self.session_index
+	}
+}