Restore block_hash to Batch

It's not only helpful (to easily check where Serai's view of the external
network is) but it's necessary in case of a non-trivial chain fork to determine
which blockchain Serai considers canonical.

coordinator/substrate/src/canonical.rs

@@ -160,6 +160,7 @@ impl<D: Db> ContinuallyRan for CanonicalEventStream<D> {
               network: batch_network,
               publishing_session,
               id,
+              external_network_block_hash,
               in_instructions_hash,
               in_instruction_results,
             } = this_batch
@@ -173,6 +174,7 @@ impl<D: Db> ContinuallyRan for CanonicalEventStream<D> {
               batch = Some(ExecutedBatch {
                 id: *id,
                 publisher: *publishing_session,
+                external_network_block_hash: *external_network_block_hash,
                 in_instructions_hash: *in_instructions_hash,
                 in_instruction_results: in_instruction_results
                   .iter()

processor/bin/src/lib.rs

@@ -277,23 +277,14 @@ pub async fn main_loop<
         } => {
           let scanner = scanner.as_mut().unwrap();
 
-          if let Some(messages::substrate::ExecutedBatch {
-            id,
-            publisher,
-            in_instructions_hash,
-            in_instruction_results,
-          }) = batch
-          {
+          if let Some(batch) = batch {
             let key_to_activate =
               KeyToActivate::<KeyFor<S>>::try_recv(txn.as_mut().unwrap()).map(|key| key.0);
 
             // This is a cheap call as it internally just queues this to be done later
             let _: () = scanner.acknowledge_batch(
               txn.take().unwrap(),
-              id,
-              publisher,
-              in_instructions_hash,
-              in_instruction_results,
+              batch,
               /*
                 `acknowledge_batch` takes burns to optimize handling returns with standard
                 payments. That's why handling these with a Batch (and not waiting until the

processor/messages/src/lib.rs

@@ -188,6 +188,7 @@ pub mod substrate {
   pub struct ExecutedBatch {
     pub id: u32,
     pub publisher: Session,
+    pub external_network_block_hash: [u8; 32],
     pub in_instructions_hash: [u8; 32],
     pub in_instruction_results: Vec<InInstructionResult>,
   }

processor/scanner/src/batch/mod.rs

@@ -10,6 +10,7 @@ use serai_in_instructions_primitives::{MAX_BATCH_SIZE, Batch};
 use primitives::{EncodableG, task::ContinuallyRan};
 use crate::{
   db::{Returnable, ScannerGlobalDb, InInstructionData, ScanToBatchDb, BatchData, BatchToReportDb},
+  index,
   scan::next_to_scan_for_outputs_block,
   ScannerFeed, KeyFor,
 };
@@ -100,10 +101,16 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for BatchTask<D, S> {
         // If this block is notable, create the Batch(s) for it
         if notable {
           let network = S::NETWORK;
+          let external_network_block_hash = index::block_id(&txn, block_number);
           let mut batch_id = BatchDb::<S>::acquire_batch_id(&mut txn);
 
           // start with empty batch
-          let mut batches = vec![Batch { network, id: batch_id, instructions: vec![] }];
+          let mut batches = vec![Batch {
+            network,
+            id: batch_id,
+            external_network_block_hash,
+            instructions: vec![],
+          }];
           // We also track the return information for the InInstructions within a Batch in case
           // they error
           let mut return_information = vec![vec![]];
@@ -123,7 +130,12 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for BatchTask<D, S> {
               batch_id = BatchDb::<S>::acquire_batch_id(&mut txn);
 
               // make a new batch with this instruction included
-              batches.push(Batch { network, id: batch_id, instructions: vec![in_instruction] });
+              batches.push(Batch {
+                network,
+                id: batch_id,
+                external_network_block_hash,
+                instructions: vec![in_instruction],
+              });
               // Since we're allocating a new batch, allocate a new set of return addresses for it
               return_information.push(vec![]);
             }

processor/scanner/src/lib.rs

@@ -11,9 +11,9 @@ use borsh::{BorshSerialize, BorshDeserialize};
 use serai_db::{Get, DbTxn, Db};
 
 use serai_primitives::{NetworkId, Coin, Amount};
-use serai_validator_sets_primitives::Session;
 use serai_coins_primitives::OutInstructionWithBalance;
 
+use messages::substrate::ExecutedBatch;
 use primitives::{task::*, Address, ReceivedOutput, Block, Payment};
 
 // Logic for deciding where in its lifetime a multisig is.
@@ -444,29 +444,17 @@ impl<S: ScannerFeed> Scanner<S> {
   /// `queue_burns`. Doing so will cause them to be executed multiple times.
   ///
   /// The calls to this function must be ordered with regards to `queue_burns`.
-  #[allow(clippy::too_many_arguments)]
   pub fn acknowledge_batch(
     &mut self,
     mut txn: impl DbTxn,
-    batch_id: u32,
-    publisher: Session,
-    in_instructions_hash: [u8; 32],
-    in_instruction_results: Vec<messages::substrate::InInstructionResult>,
+    batch: ExecutedBatch,
     burns: Vec<OutInstructionWithBalance>,
     key_to_activate: Option<KeyFor<S>>,
   ) {
-    log::info!("acknowledging batch {batch_id}");
+    log::info!("acknowledging batch {}", batch.id);
 
     // Queue acknowledging this block via the Substrate task
-    substrate::queue_acknowledge_batch::<S>(
-      &mut txn,
-      batch_id,
-      publisher,
-      in_instructions_hash,
-      in_instruction_results,
-      burns,
-      key_to_activate,
-    );
+    substrate::queue_acknowledge_batch::<S>(&mut txn, batch, burns, key_to_activate);
     // Commit this txn so this data is flushed
     txn.commit();
     // Then run the Substrate task

processor/scanner/src/substrate/db.rs

@@ -6,16 +6,14 @@ use borsh::{BorshSerialize, BorshDeserialize};
 use serai_db::{Get, DbTxn, create_db, db_channel};
 
 use serai_coins_primitives::OutInstructionWithBalance;
-use serai_validator_sets_primitives::Session;
+
+use messages::substrate::ExecutedBatch;
 
 use crate::{ScannerFeed, KeyFor};
 
 #[derive(BorshSerialize, BorshDeserialize)]
 struct AcknowledgeBatchEncodable {
-  batch_id: u32,
-  publisher: Session,
-  in_instructions_hash: [u8; 32],
-  in_instruction_results: Vec<messages::substrate::InInstructionResult>,
+  batch: ExecutedBatch,
   burns: Vec<OutInstructionWithBalance>,
   key_to_activate: Option<Vec<u8>>,
 }
@@ -27,10 +25,7 @@ enum ActionEncodable {
 }
 
 pub(crate) struct AcknowledgeBatch<S: ScannerFeed> {
-  pub(crate) batch_id: u32,
-  pub(crate) publisher: Session,
-  pub(crate) in_instructions_hash: [u8; 32],
-  pub(crate) in_instruction_results: Vec<messages::substrate::InInstructionResult>,
+  pub(crate) batch: ExecutedBatch,
   pub(crate) burns: Vec<OutInstructionWithBalance>,
   pub(crate) key_to_activate: Option<KeyFor<S>>,
 }
@@ -64,20 +59,14 @@ impl<S: ScannerFeed> SubstrateDb<S> {
 
   pub(crate) fn queue_acknowledge_batch(
     txn: &mut impl DbTxn,
-    batch_id: u32,
-    publisher: Session,
-    in_instructions_hash: [u8; 32],
-    in_instruction_results: Vec<messages::substrate::InInstructionResult>,
+    batch: ExecutedBatch,
     burns: Vec<OutInstructionWithBalance>,
     key_to_activate: Option<KeyFor<S>>,
   ) {
     Actions::send(
       txn,
       &ActionEncodable::AcknowledgeBatch(AcknowledgeBatchEncodable {
-        batch_id,
-        publisher,
-        in_instructions_hash,
-        in_instruction_results,
+        batch,
         burns,
         key_to_activate: key_to_activate.map(|key| key.to_bytes().as_ref().to_vec()),
       }),
@@ -91,17 +80,11 @@ impl<S: ScannerFeed> SubstrateDb<S> {
     let action_encodable = Actions::try_recv(txn)?;
     Some(match action_encodable {
       ActionEncodable::AcknowledgeBatch(AcknowledgeBatchEncodable {
-        batch_id,
-        publisher,
-        in_instructions_hash,
-        in_instruction_results,
+        batch,
         burns,
         key_to_activate,
       }) => Action::AcknowledgeBatch(AcknowledgeBatch {
-        batch_id,
-        publisher,
-        in_instructions_hash,
-        in_instruction_results,
+        batch,
         burns,
         key_to_activate: key_to_activate.map(|key| {
           let mut repr = <KeyFor<S> as GroupEncoding>::Repr::default();

processor/scanner/src/substrate/mod.rs

@@ -3,12 +3,12 @@ use core::{marker::PhantomData, future::Future};
 use serai_db::{Get, DbTxn, Db};
 
 use serai_coins_primitives::{OutInstruction, OutInstructionWithBalance};
-use serai_validator_sets_primitives::Session;
 
+use messages::substrate::ExecutedBatch;
 use primitives::task::ContinuallyRan;
 use crate::{
   db::{ScannerGlobalDb, SubstrateToEventualityDb, AcknowledgedBatches},
-  batch, ScannerFeed, KeyFor,
+  index, batch, ScannerFeed, KeyFor,
 };
 
 mod db;
@@ -19,22 +19,11 @@ pub(crate) fn last_acknowledged_batch<S: ScannerFeed>(getter: &impl Get) -> Opti
 }
 pub(crate) fn queue_acknowledge_batch<S: ScannerFeed>(
   txn: &mut impl DbTxn,
-  batch_id: u32,
-  publisher: Session,
-  in_instructions_hash: [u8; 32],
-  in_instruction_results: Vec<messages::substrate::InInstructionResult>,
+  batch: ExecutedBatch,
   burns: Vec<OutInstructionWithBalance>,
   key_to_activate: Option<KeyFor<S>>,
 ) {
-  SubstrateDb::<S>::queue_acknowledge_batch(
-    txn,
-    batch_id,
-    publisher,
-    in_instructions_hash,
-    in_instruction_results,
-    burns,
-    key_to_activate,
-  )
+  SubstrateDb::<S>::queue_acknowledge_batch(txn, batch, burns, key_to_activate)
 }
 pub(crate) fn queue_queue_burns<S: ScannerFeed>(
   txn: &mut impl DbTxn,
@@ -73,40 +62,38 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for SubstrateTask<D, S> {
         };
 
         match action {
-          Action::AcknowledgeBatch(AcknowledgeBatch {
-            batch_id,
-            publisher,
-            in_instructions_hash,
-            in_instruction_results,
-            mut burns,
-            key_to_activate,
-          }) => {
+          Action::AcknowledgeBatch(AcknowledgeBatch { batch, mut burns, key_to_activate }) => {
             // Check if we have the information for this batch
             let Some(batch::BatchInfo {
               block_number,
               session_to_sign_batch,
               external_key_for_session_to_sign_batch,
-              in_instructions_hash: expected_in_instructions_hash,
-            }) = batch::take_info_for_batch::<S>(&mut txn, batch_id)
+              in_instructions_hash,
+            }) = batch::take_info_for_batch::<S>(&mut txn, batch.id)
             else {
               // If we don't, drop this txn (restoring the action to the database)
               drop(txn);
               return Ok(made_progress);
             };
             assert_eq!(
-              publisher, session_to_sign_batch,
+              batch.publisher, session_to_sign_batch,
               "batch acknowledged on-chain was acknowledged by an unexpected publisher"
             );
             assert_eq!(
-              in_instructions_hash, expected_in_instructions_hash,
-              "batch acknowledged on-chain was distinct"
+              batch.external_network_block_hash,
+              index::block_id(&txn, block_number),
+              "batch acknowledged on-chain was for a distinct block"
+            );
+            assert_eq!(
+              batch.in_instructions_hash, in_instructions_hash,
+              "batch acknowledged on-chain had distinct InInstructions"
             );
 
-            SubstrateDb::<S>::set_last_acknowledged_batch(&mut txn, batch_id);
+            SubstrateDb::<S>::set_last_acknowledged_batch(&mut txn, batch.id);
             AcknowledgedBatches::send(
               &mut txn,
               &external_key_for_session_to_sign_batch.0,
-              batch_id,
+              batch.id,
             );
 
             // Mark we made progress and handle this
@@ -143,17 +130,17 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for SubstrateTask<D, S> {
 
             // Return the balances for any InInstructions which failed to execute
             {
-              let return_information = batch::take_return_information::<S>(&mut txn, batch_id)
+              let return_information = batch::take_return_information::<S>(&mut txn, batch.id)
                 .expect("didn't save the return information for Batch we published");
               assert_eq!(
-              in_instruction_results.len(),
+              batch.in_instruction_results.len(),
               return_information.len(),
               "amount of InInstruction succeededs differed from amount of return information saved"
             );
 
               // We map these into standard Burns
               for (result, return_information) in
-                in_instruction_results.into_iter().zip(return_information)
+                batch.in_instruction_results.into_iter().zip(return_information)
               {
                 if result == messages::substrate::InInstructionResult::Succeeded {
                   continue;

substrate/abi/src/in_instructions.rs

@@ -20,6 +20,7 @@ pub enum Event {
     network: NetworkId,
     publishing_session: Session,
     id: u32,
+    external_network_block_hash: [u8; 32],
     in_instructions_hash: [u8; 32],
     in_instruction_results: bitvec::vec::BitVec<u8, bitvec::order::Lsb0>,
   },

substrate/in-instructions/pallet/src/lib.rs

@@ -63,6 +63,7 @@ pub mod pallet {
     Batch {
       network: NetworkId,
       publishing_session: Session,
+      external_network_block_hash: [u8; 32],
       id: u32,
       in_instructions_hash: [u8; 32],
       in_instruction_results: BitVec<u8, Lsb0>,
@@ -356,6 +357,7 @@ pub mod pallet {
         network: batch.network,
         publishing_session: if valid_by_prior { prior_session } else { current_session },
         id: batch.id,
+        external_network_block_hash: batch.external_network_block_hash,
         in_instructions_hash,
         in_instruction_results,
       });

substrate/in-instructions/primitives/src/lib.rs

@@ -106,6 +106,7 @@ pub struct InInstructionWithBalance {
 pub struct Batch {
   pub network: NetworkId,
   pub id: u32,
+  pub external_network_block_hash: [u8; 32],
   pub instructions: Vec<InInstructionWithBalance>,
 }