On-chain unresponsiveness reporting (#1215)

* Add extrinsic to report unstable peer

* Handle errors properly

* Add a couple of reporting tests

* RustFmt

* Bump metadata

* Add benchmark for `report_unstable_peer`

* Run benches for `report_unstable_peer`

* Use benchmark result in pallet

* Add doccomment to extrinsic

* Add Slashing pallet to Propagation mock

* Actually should probably be a `dev-dependency`

* Add Slashing pallet to Attestation mock

* Add Slashing pallet to Registry mock

* TaploFmt

* Fix typo

* Add `CHANGELOG` entry

CHANGELOG.md

@@ -36,6 +36,7 @@ runtime
 - Add TSS endpoint to get TDX quote ([#1173](https://github.com/entropyxyz/entropy-core/pull/1173))
 - Add TDX test network chainspec ([#1204](https://github.com/entropyxyz/entropy-core/pull/1204))
 - Test CLI command to retrieve quote and change endpoint / TSS account in one command ([#1198](https://github.com/entropyxyz/entropy-core/pull/1198))
+- On-chain unresponsiveness reporting [(#1215)](https://github.com/entropyxyz/entropy-core/pull/1215)
 
 ### Changed
 - Use correct key rotation endpoint in OCW ([#1104](https://github.com/entropyxyz/entropy-core/pull/1104))

pallets/attestation/Cargo.toml

@@ -42,6 +42,8 @@ pallet-staking-reward-curve    ={ version="11.0.0" }
 tdx-quote                      ={ version="0.0.1", features=["mock"] }
 rand_core                      ="0.6.4"
 
+pallet-slashing={ version="0.3.0", path="../slashing", default-features=false }
+
 [features]
 default=['std']
 runtime-benchmarks=['frame-benchmarking', 'tdx-quote/mock', 'pallet-session']

pallets/attestation/src/mock.rs

@@ -64,6 +64,7 @@ frame_support::construct_runtime!(
     Historical: pallet_session_historical,
     BagsList: pallet_bags_list,
     Parameters: pallet_parameters,
+    Slashing: pallet_slashing,
   }
 );
 
@@ -342,6 +343,18 @@ impl pallet_parameters::Config for Test {
     type WeightInfo = ();
 }
 
+parameter_types! {
+    pub const ReportThreshold: u32 = 5;
+}
+
+impl pallet_slashing::Config for Test {
+    type RuntimeEvent = RuntimeEvent;
+    type AuthorityId = UintAuthorityId;
+    type ReportThreshold = ReportThreshold;
+    type ValidatorSet = Historical;
+    type ReportUnresponsiveness = ();
+}
+
 // Build genesis storage according to the mock runtime.
 pub fn new_test_ext() -> sp_io::TestExternalities {
     let mut t = system::GenesisConfig::<Test>::default().build_storage().unwrap();

pallets/propagation/Cargo.toml

@@ -29,10 +29,10 @@ sp-staking           ={ version="27.0.0", default-features=false }
 entropy-shared={ version="0.3.0", path="../../crates/shared", default-features=false, features=[
   "wasm-no-std",
 ] }
-pallet-registry={ version="0.3.0", path="../registry", default-features=false }
+pallet-attestation={ version="0.3.0", path="../attestation", default-features=false }
 pallet-programs={ version="0.3.0", path="../programs", default-features=false }
+pallet-registry={ version="0.3.0", path="../registry", default-features=false }
 pallet-staking-extension={ version="0.3.0", path="../staking", default-features=false }
-pallet-attestation={ version="0.3.0", path="../attestation", default-features=false }
 
 [dev-dependencies]
 parking_lot="0.12.3"
@@ -49,6 +49,7 @@ sp-keystore                    ={ version="0.35.0" }
 sp-npos-elections              ={ version="27.0.0", default-features=false }
 pallet-parameters              ={ version="0.3.0", path="../parameters", default-features=false }
 pallet-oracle                  ={ version='0.3.0', path='../oracle', default-features=false }
+pallet-slashing                ={ version="0.3.0", path="../slashing", default-features=false }
 
 [features]
 default=['std']

pallets/propagation/src/mock.rs

@@ -61,6 +61,7 @@ frame_support::construct_runtime!(
     Parameters: pallet_parameters,
     Attestation: pallet_attestation,
     Oracle: pallet_oracle,
+    Slashing: pallet_slashing,
   }
 );
 
@@ -394,6 +395,18 @@ impl pallet_attestation::Config for Test {
     type Randomness = TestPastRandomness;
 }
 
+parameter_types! {
+    pub const ReportThreshold: u32 = 5;
+}
+
+impl pallet_slashing::Config for Test {
+    type RuntimeEvent = RuntimeEvent;
+    type AuthorityId = UintAuthorityId;
+    type ReportThreshold = ReportThreshold;
+    type ValidatorSet = Historical;
+    type ReportUnresponsiveness = ();
+}
+
 // Build genesis storage according to the mock runtime.
 pub fn new_test_ext() -> sp_io::TestExternalities {
     let mut t = system::GenesisConfig::<Test>::default().build_storage().unwrap();

pallets/registry/Cargo.toml

@@ -46,6 +46,7 @@ sp-io                          ={ version="31.0.0", default-features=false }
 sp-npos-elections              ={ version="27.0.0", default-features=false }
 sp-staking                     ={ version="27.0.0", default-features=false }
 pallet-oracle                  ={ version='0.3.0', path='../oracle', default-features=false }
+pallet-slashing                ={ version="0.3.0", path="../slashing", default-features=false }
 
 [features]
 

pallets/registry/src/benchmarking.rs

@@ -216,7 +216,7 @@ benchmarks! {
     let network_verifying_key =
         synedrion::ecdsa::VerifyingKey::try_from(network_verifying_key.as_slice()).unwrap();
 
-    // We substract one from the count since this gets incremented after a succesful registration,
+    // We subtract one from the count since this gets incremented after a succesful registration,
     // and we're interested in the account we just registered.
     let count = <Registered<T>>::count() - 1;
     let derivation_path =

pallets/registry/src/mock.rs

@@ -60,6 +60,7 @@ frame_support::construct_runtime!(
     Programs: pallet_programs,
     Parameters: pallet_parameters,
     Oracle: pallet_oracle,
+    Slashing: pallet_slashing,
   }
 );
 
@@ -380,6 +381,18 @@ impl pallet_parameters::Config for Test {
     type WeightInfo = ();
 }
 
+parameter_types! {
+    pub const ReportThreshold: u32 = 5;
+}
+
+impl pallet_slashing::Config for Test {
+    type RuntimeEvent = RuntimeEvent;
+    type AuthorityId = UintAuthorityId;
+    type ReportThreshold = ReportThreshold;
+    type ValidatorSet = Historical;
+    type ReportUnresponsiveness = ();
+}
+
 // Build genesis storage according to the mock runtime.
 pub fn new_test_ext() -> sp_io::TestExternalities {
     let mut t = system::GenesisConfig::<Test>::default().build_storage().unwrap();

pallets/staking/Cargo.toml

@@ -34,6 +34,7 @@ p256              ={ version="0.13.2", default-features=false, features=["ecdsa"
 rand              ={ version="0.8.5", default-features=false, features=["alloc"] }
 
 pallet-parameters={ version="0.3.0", path="../parameters", default-features=false }
+pallet-slashing={ version="0.3.0", path="../slashing", default-features=false }
 entropy-shared={ version="0.3.0", path="../../crates/shared", features=[
   "wasm-no-std",
 ], default-features=false }
@@ -69,6 +70,7 @@ std=[
   'pallet-balances/std',
   'pallet-parameters/std',
   'pallet-session/std',
+  'pallet-slashing/std',
   'pallet-staking/std',
   'scale-info/std',
   'sp-consensus-babe/std',

pallets/staking/src/benchmarking.rs

@@ -29,6 +29,7 @@ use frame_support::{
 };
 use frame_system::{EventRecord, RawOrigin};
 use pallet_parameters::{SignersInfo, SignersSize};
+use pallet_slashing::Event as SlashingEvent;
 use pallet_staking::{
     Event as FrameStakingEvent, MaxNominationsOf, MaxValidatorsCount, Nominations,
     Pallet as FrameStaking, RewardDestination, ValidatorPrefs,
@@ -56,6 +57,16 @@ fn assert_last_event_frame_staking<T: Config>(
     assert_eq!(event, &system_event);
 }
 
+fn assert_last_event_slashing<T: Config>(
+    generic_event: <T as pallet_slashing::Config>::RuntimeEvent,
+) {
+    let events = frame_system::Pallet::<T>::events();
+    let system_event: <T as frame_system::Config>::RuntimeEvent = generic_event.into();
+    // compare to the last event record
+    let EventRecord { event, .. } = &events[events.len() - 1];
+    assert_eq!(event, &system_event);
+}
+
 pub fn create_validators<T: Config>(
     count: u32,
     seed: u32,
@@ -518,6 +529,37 @@ benchmarks! {
   verify {
     assert!(NextSigners::<T>::get().is_some());
   }
+
+  report_unstable_peer {
+    // We subtract `2` here to give room to our test signers
+    let s in 0 .. (MAX_SIGNERS - 2) as u32;
+
+    let threshold_reporter: T::AccountId = whitelisted_caller();
+    let threshold_offender: T::AccountId = account("threshold_offender", 0, SEED);
+
+    let reporter_validator_id = <T as pallet_session::Config>::ValidatorId::try_from(threshold_reporter.clone())
+        .or(Err(Error::<T>::InvalidValidatorId))
+        .unwrap();
+
+    let offender_validator_id = <T as pallet_session::Config>::ValidatorId::try_from(threshold_offender.clone())
+        .or(Err(Error::<T>::InvalidValidatorId))
+        .unwrap();
+
+    ThresholdToStash::<T>::insert(&threshold_reporter, &reporter_validator_id);
+    ThresholdToStash::<T>::insert(&threshold_offender, &offender_validator_id);
+
+    let mut signers = vec![reporter_validator_id.clone(); s as usize];
+    signers.push(reporter_validator_id);
+    signers.push(offender_validator_id);
+
+    Signers::<T>::put(signers.clone());
+
+  }:  _(RawOrigin::Signed(threshold_reporter.clone()), threshold_offender.clone())
+  verify {
+    assert_last_event_slashing::<T>(
+        pallet_slashing::Event::NoteReport(threshold_reporter, threshold_offender).into(),
+    );
+  }
 }
 
 impl_benchmark_test_suite!(Staking, crate::mock::new_test_ext(), crate::mock::Test);

pallets/staking/src/lib.rs

@@ -90,6 +90,7 @@ pub mod pallet {
         + frame_system::Config
         + pallet_staking::Config
         + pallet_parameters::Config
+        + pallet_slashing::Config
     {
         /// Because this pallet emits events, it depends on the runtime's definition of an event.
         type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
@@ -336,6 +337,7 @@ pub mod pallet {
         InvalidValidatorId,
         SigningGroupError,
         TssAccountAlreadyExists,
+        NotSigner,
         NotNextSigner,
         ReshareNotInProgress,
         AlreadyConfirmed,
@@ -735,6 +737,57 @@ pub mod pallet {
             // signers see https://github.com/entropyxyz/entropy-core/issues/985
             Ok(Pays::No.into())
         }
+
+        /// An on-chain hook for TSS servers in the signing committee to report other TSS servers in
+        /// the committee for misbehaviour.
+        ///
+        /// Any "conequences" are handled by the configured Slashing pallet and not this pallet
+        /// itself.
+        #[pallet::call_index(7)]
+        #[pallet::weight(<T as Config>::WeightInfo::report_unstable_peer(MAX_SIGNERS as u32))]
+        pub fn report_unstable_peer(
+            origin: OriginFor<T>,
+            offender_tss_account: T::AccountId,
+        ) -> DispatchResultWithPostInfo {
+            let reporter_tss_account = ensure_signed(origin)?;
+
+            // For reporting purposes we need to know the validator account tied to the TSS account.
+            let reporter_validator_id = Self::threshold_to_stash(&reporter_tss_account)
+                .ok_or(Error::<T>::NoThresholdKey)?;
+            let offender_validator_id = Self::threshold_to_stash(&offender_tss_account)
+                .ok_or(Error::<T>::NoThresholdKey)?;
+
+            // Note: This operation is O(n), but with a small enough Signer group this should be
+            // fine to do on-chain.
+            let signers = Self::signers();
+            ensure!(signers.contains(&reporter_validator_id), Error::<T>::NotSigner);
+            ensure!(signers.contains(&offender_validator_id), Error::<T>::NotSigner);
+
+            // We do a bit of a weird conversion here since we want the validator's underlying
+            // `AccountId` for the reporting mechanism, not their `ValidatorId`.
+            //
+            // The Session pallet should have this configured to be the same thing, but we can't
+            // prove that to the compiler.
+            let encoded_validator_id = T::ValidatorId::encode(&reporter_validator_id);
+            let reporter_validator_account = T::AccountId::decode(&mut &encoded_validator_id[..])
+                .expect("A `ValidatorId` should be equivalent to an `AccountId`.");
+
+            let encoded_validator_id = T::ValidatorId::encode(&offender_validator_id);
+            let offending_peer_validator_account =
+                T::AccountId::decode(&mut &encoded_validator_id[..])
+                    .expect("A `ValidatorId` should be equivalent to an `AccountId`.");
+
+            // We don't actually take any action here, we offload the reporting to the Slashing
+            // pallet.
+            pallet_slashing::Pallet::<T>::note_report(
+                reporter_validator_account,
+                offending_peer_validator_account,
+            )?;
+
+            let actual_weight =
+                <T as Config>::WeightInfo::report_unstable_peer(signers.len() as u32);
+            Ok(Some(actual_weight).into())
+        }
     }
 
     impl<T: Config> Pallet<T> {

pallets/staking/src/mock.rs

@@ -63,6 +63,7 @@ frame_support::construct_runtime!(
     Historical: pallet_session_historical,
     BagsList: pallet_bags_list,
     Parameters: pallet_parameters,
+    Slashing: pallet_slashing,
   }
 );
 
@@ -418,6 +419,43 @@ impl entropy_shared::AttestationHandler<AccountId> for MockAttestationHandler {
     fn request_quote(_attestee: &AccountId, _nonce: [u8; 32]) {}
 }
 
+type IdentificationTuple = (u64, pallet_staking::Exposure<AccountId, Balance>);
+type Offence = pallet_slashing::UnresponsivenessOffence<IdentificationTuple>;
+
+parameter_types! {
+    pub static Offences: Vec<Offence> = vec![];
+}
+
+/// A mock offence report handler.
+pub struct OffenceHandler;
+impl sp_staking::offence::ReportOffence<AccountId, IdentificationTuple, Offence>
+    for OffenceHandler
+{
+    fn report_offence(
+        _reporters: Vec<u64>,
+        offence: Offence,
+    ) -> Result<(), sp_staking::offence::OffenceError> {
+        Offences::mutate(|l| l.push(offence));
+        Ok(())
+    }
+
+    fn is_known_offence(_offenders: &[IdentificationTuple], _time_slot: &SessionIndex) -> bool {
+        false
+    }
+}
+
+parameter_types! {
+    pub const ReportThreshold: u32 = 5;
+}
+
+impl pallet_slashing::Config for Test {
+    type RuntimeEvent = RuntimeEvent;
+    type AuthorityId = UintAuthorityId;
+    type ReportThreshold = ReportThreshold;
+    type ValidatorSet = Historical;
+    type ReportUnresponsiveness = OffenceHandler;
+}
+
 impl pallet_staking_extension::Config for Test {
     type AttestationHandler = MockAttestationHandler;
     type Currency = Balances;