Refactor out disable/disconnect peer to make API more declarative (#394)

* Refactor out disable/disconnect peer to make API more declarative

* Minor fixes.

* rename `disconnect_peer` to `drop_peer` in low-level

polkadot/network/src/lib.rs

@@ -49,7 +49,7 @@ use parking_lot::Mutex;
 use polkadot_consensus::{Statement, SignedStatement, GenericStatement};
 use polkadot_primitives::{AccountId, Block, SessionKey, Hash, Header};
 use polkadot_primitives::parachain::{Id as ParaId, BlockData, Extrinsic, CandidateReceipt, Collation};
-use substrate_network::{PeerId, RequestId, Context};
+use substrate_network::{PeerId, RequestId, Context, Severity};
 use substrate_network::consensus_gossip::ConsensusGossip;
 use substrate_network::{message, generic_message};
 use substrate_network::specialization::Specialization;
@@ -403,7 +403,7 @@ impl PolkadotProtocol {
 			};
 
 			if !info.claimed_validator {
-				ctx.disable_peer(peer_id, "Session key broadcasted without setting authority role");
+				ctx.report_peer(peer_id, Severity::Bad("Session key broadcasted without setting authority role"));
 				return;
 			}
 
@@ -438,7 +438,7 @@ impl PolkadotProtocol {
 				self.pending.push(req);
 				self.dispatch_pending_requests(ctx);
 			}
-			None => ctx.disable_peer(peer_id, "Unexpected block data response"),
+			None => ctx.report_peer(peer_id, Severity::Bad("Unexpected block data response")),
 		}
 	}
 
@@ -453,9 +453,9 @@ impl PolkadotProtocol {
 		};
 
 		match info.validator_key {
-			None => ctx.disable_peer(
+			None => ctx.report_peer(
 				peer_id,
-				"Sent collator role without registering first as validator",
+				Severity::Bad("Sent collator role without registering first as validator"),
 			),
 			Some(key) => for (relay_parent, collation) in self.local_collations.note_validator_role(key, role) {
 				send_polkadot_message(
@@ -483,7 +483,7 @@ impl Specialization<Block> for PolkadotProtocol {
 
 		if let Some((ref acc_id, ref para_id)) = local_status.collating_for {
 			if self.collator_peer_id(acc_id.clone()).is_some() {
-				ctx.disconnect_peer(peer_id);
+				ctx.report_peer(peer_id, Severity::Useless("Unknown Polkadot-specific reason"));
 				return
 			}
 
@@ -571,7 +571,7 @@ impl Specialization<Block> for PolkadotProtocol {
 					Some(msg) => self.on_polkadot_message(ctx, peer_id, raw, msg),
 					None => {
 						trace!(target: "p_net", "Bad message from {}", peer_id);
-						ctx.disable_peer(peer_id, "Invalid polkadot protocol message format");
+						ctx.report_peer(peer_id, Severity::Bad("Invalid polkadot protocol message format"));
 					}
 				}
 			}
@@ -616,15 +616,15 @@ impl PolkadotProtocol {
 		let collated_acc = collation.receipt.collator;
 
 		match self.peers.get(&from) {
-			None => ctx.disconnect_peer(from),
+			None => ctx.report_peer(from, Severity::Useless("Unknown Polkadot specific reason")),
 			Some(peer_info) => match peer_info.collating_for {
-				None => ctx.disable_peer(from, "Sent collation without registering collator intent"),
+				None => ctx.report_peer(from, Severity::Bad("Sent collation without registering collator intent")),
 				Some((ref acc_id, ref para_id)) => {
 					let structurally_valid = para_id == &collation_para && acc_id == &collated_acc;
 					if structurally_valid && collation.receipt.check_signature().is_ok() {
 						self.collators.on_collation(acc_id.clone(), relay_parent, collation)
 					} else {
-						ctx.disable_peer(from, "Sent malformed collation")
+						ctx.report_peer(from, Severity::Bad("Sent malformed collation"))
 					};
 				}
 			},
@@ -654,7 +654,7 @@ impl PolkadotProtocol {
 	// disconnect a collator by account-id.
 	fn disconnect_bad_collator(&self, ctx: &mut Context<Block>, account_id: AccountId) {
 		if let Some(peer_id) = self.collator_peer_id(account_id) {
-			ctx.disable_peer(peer_id, "Consensus layer determined the given collator misbehaved")
+			ctx.report_peer(peer_id, Severity::Bad("Consensus layer determined the given collator misbehaved"))
 		}
 	}
 }

polkadot/network/src/tests.rs

@@ -24,7 +24,7 @@ use polkadot_primitives::{Block, Hash, SessionKey};
 use polkadot_primitives::parachain::{CandidateReceipt, HeadData, BlockData};
 use substrate_primitives::H512;
 use codec::Encode;
-use substrate_network::{PeerId, PeerInfo, ClientHandle, Context, Roles, message::Message as SubstrateMessage, specialization::Specialization, generic_message::Message as GenericMessage};
+use substrate_network::{Severity, PeerId, PeerInfo, ClientHandle, Context, Roles, message::Message as SubstrateMessage, specialization::Specialization, generic_message::Message as GenericMessage};
 
 use std::sync::Arc;
 use futures::Future;
@@ -41,12 +41,11 @@ impl Context<Block> for TestContext {
 		unimplemented!()
 	}
 
-	fn disable_peer(&mut self, peer: PeerId, _reason: &str) {
-		self.disabled.push(peer);
-	}
-
-	fn disconnect_peer(&mut self, peer: PeerId) {
-		self.disconnected.push(peer);
+	fn report_peer(&mut self, peer: PeerId, reason: Severity) {
+		match reason {
+			Severity::Bad(_) => self.disabled.push(peer),
+			_ => self.disconnected.push(peer),
+		}
 	}
 
 	fn peer_info(&self, _peer: PeerId) -> Option<PeerInfo<Block>> {