Support sending and receiving multiple Justifications (#8266)

* client/network: support sending multiple justifications

* network: flag support for multiple justifications in protobuf request

* Update client/network/src/protocol.rs

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

* network: update comment on protobuf field

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

substrate/client/network/src/protocol/message.rs

@@ -168,7 +168,7 @@ impl<H: HeaderT> generic::BlockAnnounce<H> {
 pub mod generic {
 	use bitflags::bitflags;
 	use codec::{Encode, Decode, Input, Output};
-	use sp_runtime::EncodedJustification;
+	use sp_runtime::{EncodedJustification, Justifications};
 	use super::{
 		RemoteReadResponse, Transactions, Direction,
 		RequestId, BlockAttributes, RemoteCallResponse, ConsensusEngineId,
@@ -254,6 +254,8 @@ pub mod generic {
 		pub message_queue: Option<Vec<u8>>,
 		/// Justification if requested.
 		pub justification: Option<EncodedJustification>,
+		/// Justifications if requested.
+		pub justifications: Option<Justifications>,
 	}
 
 	/// Identifies starting point of a block sequence.

substrate/client/network/src/protocol/sync.rs

@@ -833,8 +833,9 @@ impl<B: BlockT> ChainSync<B> {
 								.drain(self.best_queued_number + One::one())
 								.into_iter()
 								.map(|block_data| {
-									let justifications =
-										legacy_justification_mapping(block_data.block.justification);
+									let justifications = block_data.block.justifications.or(
+										legacy_justification_mapping(block_data.block.justification)
+									);
 									IncomingBlock {
 										hash: block_data.block.hash,
 										header: block_data.block.header,
@@ -854,11 +855,14 @@ impl<B: BlockT> ChainSync<B> {
 							}
 							validate_blocks::<B>(&blocks, who, Some(request))?;
 							blocks.into_iter().map(|b| {
+								let justifications = b.justifications.or(
+									legacy_justification_mapping(b.justification)
+								);
 								IncomingBlock {
 									hash: b.hash,
 									header: b.header,
 									body: b.body,
-									justifications: legacy_justification_mapping(b.justification),
+									justifications,
 									origin: Some(who.clone()),
 									allow_missing_state: true,
 									import_existing: false,
@@ -963,11 +967,14 @@ impl<B: BlockT> ChainSync<B> {
 					// When request.is_none() this is a block announcement. Just accept blocks.
 					validate_blocks::<B>(&blocks, who, None)?;
 					blocks.into_iter().map(|b| {
+						let justifications = b.justifications.or(
+							legacy_justification_mapping(b.justification)
+						);
 						IncomingBlock {
 							hash: b.hash,
 							header: b.header,
 							body: b.body,
-							justifications: legacy_justification_mapping(b.justification),
+							justifications,
 							origin: Some(who.clone()),
 							allow_missing_state: true,
 							import_existing: false,
@@ -1043,7 +1050,7 @@ impl<B: BlockT> ChainSync<B> {
 					return Err(BadPeer(who, rep::BAD_JUSTIFICATION));
 				}
 
-				block.justification
+				block.justifications.or(legacy_justification_mapping(block.justification))
 			} else {
 				// we might have asked the peer for a justification on a block that we assumed it
 				// had but didn't (regardless of whether it had a justification for it or not).
@@ -1058,7 +1065,7 @@ impl<B: BlockT> ChainSync<B> {
 
 			if let Some((peer, hash, number, j)) = self
 				.extra_justifications
-				.on_response(who, legacy_justification_mapping(justification))
+				.on_response(who, justification)
 			{
 				return Ok(OnBlockJustification::Import { peer, hash, number, justifications: j })
 			}
@@ -1655,7 +1662,7 @@ impl<B: BlockT> ChainSync<B> {
 // This is purely during a backwards compatible transitionary period and should be removed
 // once we can assume all nodes can send and receive multiple Justifications
 // The ID tag is hardcoded here to avoid depending on the GRANDPA crate.
-// TODO: https://github.com/paritytech/substrate/issues/8172
+// See: https://github.com/paritytech/substrate/issues/8172
 fn legacy_justification_mapping(justification: Option<EncodedJustification>) -> Option<Justifications> {
 	justification.map(|just| (*b"FRNK", just).into())
 }
@@ -2163,6 +2170,7 @@ mod test {
 					receipt: None,
 					message_queue: None,
 					justification: None,
+					justifications: None,
 				}
 			).collect(),
 		}

substrate/client/network/src/protocol/sync/blocks.rs

@@ -228,6 +228,7 @@ mod test {
 			message_queue: None,
 			receipt: None,
 			justification: None,
+			justifications: None,
 		}).collect()
 	}