babe: report equivocations (#6362)

* slots: create primitives crate for consensus slots

* offences: add method to check if an offence is unknown

* babe: initial equivocation reporting implementation

* babe: organize imports

* babe: working equivocation reporting

* babe: add slot number to equivocation proof

* session: move duplicate traits to session primitives

* babe: move equivocation stuff to its own file

* offences: fix test

* session: don't have primitives depend on frame_support

* babe: use opaque type for key owner proof

* babe: cleanup client equivocation reporting

* babe: cleanup equivocation code in pallet

* babe: allow sending signed equivocation reports

* node: fix compilation

* fix test compilation

* babe: return bool on check_equivocation_proof

* babe: add test for equivocation reporting

* babe: add more tests

* babe: add test for validate unsigned

* babe: take slot number in generate_key_ownership_proof API

* babe: add benchmark for equivocation proof checking

* session: add benchmark for membership proof checking

* offences: fix babe benchmark

* babe: add weights based on benchmark results

* babe: adjust weights after benchmarking on reference hardware

* babe: reorder checks in check_and_report_equivocation

Author: andresilva

src/mock.rs

@@ -86,10 +86,16 @@ impl ReportOffence<u64, IdentificationTuple, Offence> for OffenceHandler {
 		OFFENCES.with(|l| l.borrow_mut().push((reporters, offence)));
 		Ok(())
 	}
+
+	fn is_known_offence(_offenders: &[IdentificationTuple], _time_slot: &SessionIndex) -> bool {
+		false
+	}
 }
 
 pub fn new_test_ext() -> sp_io::TestExternalities {
-	let t = frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap();
+	let t = frame_system::GenesisConfig::default()
+		.build_storage::<Runtime>()
+		.unwrap();
 	t.into()
 }