Remove ProspectiveParachainsMode usage in backing subsystem

polkadot/node/subsystem-util/src/backing_implicit_view.rs

@@ -20,14 +20,14 @@ use polkadot_node_subsystem::{
 	messages::{ChainApiMessage, ProspectiveParachainsMessage, RuntimeApiMessage},
 	SubsystemSender,
 };
-use polkadot_primitives::{BlockNumber, Hash, Id as ParaId};
+use polkadot_primitives::{AsyncBackingParams, BlockNumber, Hash, Id as ParaId};
 
 use std::collections::HashMap;
 
 use crate::{
 	inclusion_emulator::RelayChainBlockInfo,
-	request_session_index_for_child,
-	runtime::{self, prospective_parachains_mode, recv_runtime, ProspectiveParachainsMode},
+	request_async_backing_params, request_session_index_for_child,
+	runtime::{self, recv_runtime},
 };
 
 // Always aim to retain 1 block before the active leaves.
@@ -396,13 +396,8 @@ where
 		+ SubsystemSender<RuntimeApiMessage>
 		+ SubsystemSender<ChainApiMessage>,
 {
-	let Ok(ProspectiveParachainsMode::Enabled { allowed_ancestry_len, .. }) =
-		prospective_parachains_mode(sender, leaf_hash).await
-	else {
-		// This should never happen, leaves that don't have prospective parachains mode enabled
-		// should not use implicit view.
-		return Ok(None)
-	};
+	let AsyncBackingParams { allowed_ancestry_len, .. } =
+		recv_runtime(request_async_backing_params(leaf_hash, sender).await).await?;
 
 	// Fetch the session of the leaf. We must make sure that we stop at the ancestor which has a
 	// different session index.
@@ -416,7 +411,7 @@ where
 	sender
 		.send_message(ChainApiMessage::Ancestors {
 			hash: leaf_hash,
-			k: allowed_ancestry_len,
+			k: allowed_ancestry_len as usize,
 			response_channel: tx,
 		})
 		.await;

polkadot/roadmap/implementers-guide/src/node/utility/provisioner.md

@@ -74,9 +74,8 @@ Subsystem](../disputes/dispute-coordinator.md). Misbehavior reports are currentl
 subsystem](../backing/candidate-backing.md) and contain the following misbehaviors:
 
 1. `Misbehavior::ValidityDoubleVote`
-2. `Misbehavior::MultipleCandidates`
-3. `Misbehavior::UnauthorizedStatement`
-4. `Misbehavior::DoubleSign`
+2. `Misbehavior::UnauthorizedStatement`
+3. `Misbehavior::DoubleSign`
 
 But we choose not to punish these forms of misbehavior for the time being. Risks from misbehavior are sufficiently
 mitigated at the protocol level via reputation changes. Punitive actions here may become desirable enough to dedicate

polkadot/roadmap/implementers-guide/src/types/overseer-protocol.md

@@ -697,14 +697,6 @@ mod generic {
         Invalidity(Digest, Signature, Signature),
     }
 
-    /// Misbehavior: declaring multiple candidates.
-    pub struct MultipleCandidates<Candidate, Signature> {
-        /// The first candidate seen.
-        pub first: (Candidate, Signature),
-        /// The second candidate seen.
-        pub second: (Candidate, Signature),
-    }
-
     /// Misbehavior: submitted statement for wrong group.
     pub struct UnauthorizedStatement<Candidate, Digest, AuthorityId, Signature> {
         /// A signed statement which was submitted without proper authority.
@@ -714,8 +706,6 @@ mod generic {
     pub enum Misbehavior<Candidate, Digest, AuthorityId, Signature> {
         /// Voted invalid and valid on validity.
         ValidityDoubleVote(ValidityDoubleVote<Candidate, Digest, Signature>),
-        /// Submitted multiple candidates.
-        MultipleCandidates(MultipleCandidates<Candidate, Signature>),
         /// Submitted a message that was unauthorized.
         UnauthorizedStatement(UnauthorizedStatement<Candidate, Digest, AuthorityId, Signature>),
         /// Submitted two valid signatures for the same message.

polkadot/statement-table/src/generic.rs

@@ -62,14 +62,6 @@ pub trait Context {
 	fn get_group_size(&self, group: &Self::GroupId) -> Option<usize>;
 }
 
-/// Table configuration.
-pub struct Config {
-	/// When this is true, the table will allow multiple seconded candidates
-	/// per authority. This flag means that higher-level code is responsible for
-	/// bounding the number of candidates.
-	pub allow_multiple_seconded: bool,
-}
-
 /// Statements circulated among peers.
 #[derive(PartialEq, Eq, Debug, Clone, Encode, Decode)]
 pub enum Statement<Candidate, Digest> {
@@ -143,15 +135,6 @@ impl<Candidate, Digest, Signature> DoubleSign<Candidate, Digest, Signature> {
 	}
 }
 
-/// Misbehavior: declaring multiple candidates.
-#[derive(PartialEq, Eq, Debug, Clone)]
-pub struct MultipleCandidates<Candidate, Signature> {
-	/// The first candidate seen.
-	pub first: (Candidate, Signature),
-	/// The second candidate seen.
-	pub second: (Candidate, Signature),
-}
-
 /// Misbehavior: submitted statement for wrong group.
 #[derive(PartialEq, Eq, Debug, Clone)]
 pub struct UnauthorizedStatement<Candidate, Digest, AuthorityId, Signature> {
@@ -165,8 +148,6 @@ pub struct UnauthorizedStatement<Candidate, Digest, AuthorityId, Signature> {
 pub enum Misbehavior<Candidate, Digest, AuthorityId, Signature> {
 	/// Voted invalid and valid on validity.
 	ValidityDoubleVote(ValidityDoubleVote<Candidate, Digest, Signature>),
-	/// Submitted multiple candidates.
-	MultipleCandidates(MultipleCandidates<Candidate, Signature>),
 	/// Submitted a message that was unauthorized.
 	UnauthorizedStatement(UnauthorizedStatement<Candidate, Digest, AuthorityId, Signature>),
 	/// Submitted two valid signatures for the same message.
@@ -300,17 +281,14 @@ pub struct Table<Ctx: Context> {
 	authority_data: HashMap<Ctx::AuthorityId, AuthorityData<Ctx>>,
 	detected_misbehavior: HashMap<Ctx::AuthorityId, Vec<MisbehaviorFor<Ctx>>>,
 	candidate_votes: HashMap<Ctx::Digest, CandidateData<Ctx>>,
-	config: Config,
 }
 
 impl<Ctx: Context> Table<Ctx> {
-	/// Create a new `Table` from a `Config`.
-	pub fn new(config: Config) -> Self {
+	pub fn new() -> Self {
 		Table {
 			authority_data: HashMap::default(),
 			detected_misbehavior: HashMap::default(),
 			candidate_votes: HashMap::default(),
-			config,
 		}
 	}
 
@@ -408,33 +386,7 @@ impl<Ctx: Context> Table<Ctx> {
 				// if digest is different, fetch candidate and
 				// note misbehavior.
 				let existing = occ.get_mut();
-
-				if !self.config.allow_multiple_seconded && existing.proposals.len() == 1 {
-					let (old_digest, old_sig) = &existing.proposals[0];
-
-					if old_digest != &digest {
-						const EXISTENCE_PROOF: &str =
-							"when proposal first received from authority, candidate \
-							votes entry is created. proposal here is `Some`, therefore \
-							candidate votes entry exists; qed";
-
-						let old_candidate = self
-							.candidate_votes
-							.get(old_digest)
-							.expect(EXISTENCE_PROOF)
-							.candidate
-							.clone();
-
-						return Err(Misbehavior::MultipleCandidates(MultipleCandidates {
-							first: (old_candidate, old_sig.clone()),
-							second: (candidate, signature.clone()),
-						}))
-					}
-
-					false
-				} else if self.config.allow_multiple_seconded &&
-					existing.proposals.iter().any(|(ref od, _)| od == &digest)
-				{
+				if existing.proposals.iter().any(|(ref od, _)| od == &digest) {
 					false
 				} else {
 					existing.proposals.push((digest.clone(), signature.clone()));
@@ -591,14 +543,6 @@ mod tests {
 	use super::*;
 	use std::collections::HashMap;
 
-	fn create_single_seconded<Candidate: Context>() -> Table<Candidate> {
-		Table::new(Config { allow_multiple_seconded: false })
-	}
-
-	fn create_many_seconded<Candidate: Context>() -> Table<Candidate> {
-		Table::new(Config { allow_multiple_seconded: true })
-	}
-
 	#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 	struct AuthorityId(usize);
 
@@ -646,42 +590,6 @@ mod tests {
 		}
 	}
 
-	#[test]
-	fn submitting_two_candidates_can_be_misbehavior() {
-		let context = TestContext {
-			authorities: {
-				let mut map = HashMap::new();
-				map.insert(AuthorityId(1), GroupId(2));
-				map
-			},
-		};
-
-		let mut table = create_single_seconded();
-		let statement_a = SignedStatement {
-			statement: Statement::Seconded(Candidate(2, 100)),
-			signature: Signature(1),
-			sender: AuthorityId(1),
-		};
-
-		let statement_b = SignedStatement {
-			statement: Statement::Seconded(Candidate(2, 999)),
-			signature: Signature(1),
-			sender: AuthorityId(1),
-		};
-
-		table.import_statement(&context, GroupId(2), statement_a);
-		assert!(!table.detected_misbehavior.contains_key(&AuthorityId(1)));
-
-		table.import_statement(&context, GroupId(2), statement_b);
-		assert_eq!(
-			table.detected_misbehavior[&AuthorityId(1)][0],
-			Misbehavior::MultipleCandidates(MultipleCandidates {
-				first: (Candidate(2, 100), Signature(1)),
-				second: (Candidate(2, 999), Signature(1)),
-			})
-		);
-	}
-
 	#[test]
 	fn submitting_two_candidates_can_be_allowed() {
 		let context = TestContext {
@@ -692,7 +600,7 @@ mod tests {
 			},
 		};
 
-		let mut table = create_many_seconded();
+		let mut table = Table::new();
 		let statement_a = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
 			signature: Signature(1),
@@ -722,7 +630,7 @@ mod tests {
 			},
 		};
 
-		let mut table = create_single_seconded();
+		let mut table = Table::new();
 		let statement = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
 			signature: Signature(1),
@@ -754,7 +662,7 @@ mod tests {
 			},
 		};
 
-		let mut table = create_single_seconded();
+		let mut table = Table::new();
 
 		let candidate_a = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
@@ -798,7 +706,7 @@ mod tests {
 			},
 		};
 
-		let mut table = create_single_seconded();
+		let mut table = Table::new();
 		let statement = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
 			signature: Signature(1),
@@ -828,7 +736,7 @@ mod tests {
 			},
 		};
 
-		let mut table = create_single_seconded();
+		let mut table = Table::new();
 		let statement = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
 			signature: Signature(1),
@@ -896,7 +804,7 @@ mod tests {
 		};
 
 		// have 2/3 validity guarantors note validity.
-		let mut table = create_single_seconded();
+		let mut table = Table::new();
 		let statement = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
 			signature: Signature(1),
@@ -930,7 +838,7 @@ mod tests {
 			},
 		};
 
-		let mut table = create_single_seconded();
+		let mut table = Table::new();
 		let statement = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
 			signature: Signature(1),
@@ -957,7 +865,7 @@ mod tests {
 			},
 		};
 
-		let mut table = create_single_seconded();
+		let mut table = Table::new();
 		let statement = SignedStatement {
 			statement: Statement::Seconded(Candidate(2, 100)),
 			signature: Signature(1),

polkadot/statement-table/src/lib.rs

@@ -29,7 +29,7 @@
 
 pub mod generic;
 
-pub use generic::{Config, Context, Table};
+pub use generic::{Context, Table};
 
 /// Concrete instantiations suitable for v2 primitives.
 pub mod v2 {

prdoc/pr_6215.prdoc

@@ -0,0 +1,16 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Remove `ProspectiveParachainsMode` from backing subsystem
+doc:
+  - audience: "Node Dev"
+    description: |
+      Removes `ProspectiveParachainsMode` usage from the backing subsystem and assumes
+      `async_backing_params` runtime api is always available. Since the runtime api v7 is released on
+      all networks it should always be true.
+
+crates:
+  - name: polkadot-node-core-backing
+    bump: patch
+  - name: polkadot-statement-table
+    bump: major