Simplify async code in in_instructions_unordered

Outsources fetching the ERC20 events to top_level_transfers_unordered.

processor/ethereum/erc20/src/lib.rs

@@ -2,8 +2,7 @@
 #![doc = include_str!("../README.md")]
 #![deny(missing_docs)]
 
-use core::borrow::Borrow;
+use std::collections::HashMap;
-use std::{sync::Arc, collections::HashMap};
 
 use alloy_core::primitives::{Address, U256};
 
@@ -57,20 +56,27 @@ pub struct TopLevelTransfer {
   pub data: Vec<u8>,
 }
 
+/// The result of `Erc20::top_level_transfers_unordered`.
+pub struct TopLevelTransfers {
+  /// Every `Transfer` log of the contextual ERC20 to the contextual account, indexed by
+  /// their transaction.
+  ///
+  /// The ERC20/account is labelled contextual as it isn't directly named here. Instead, they're
+  /// assumed contextual to how this was created.
+  pub logs: HashMap<[u8; 32], Vec<Log>>,
+  /// All of the top-level transfers of the contextual ERC20 to the contextual account.
+  ///
+  /// The ERC20/account is labelled contextual as it isn't directly named here. Instead, they're
+  /// assumed contextual to how this was created.
+  pub transfers: Vec<TopLevelTransfer>,
+}
+
 /// A view for an ERC20 contract.
 #[derive(Clone, Debug)]
-pub struct Erc20 {
+pub struct Erc20;
-  provider: Arc<RootProvider<SimpleRequest>>,
-  address: Address,
-}
 impl Erc20 {
-  /// Construct a new view of the specified ERC20 contract.
-  pub fn new(provider: Arc<RootProvider<SimpleRequest>>, address: Address) -> Self {
-    Self { provider, address }
-  }
-
   /// The filter for transfer logs of the specified ERC20, to the specified recipient.
-  pub fn transfer_filter(from_block: u64, to_block: u64, erc20: Address, to: Address) -> Filter {
+  fn transfer_filter(from_block: u64, to_block: u64, erc20: Address, to: Address) -> Filter {
     let filter = Filter::new().from_block(from_block).to_block(to_block);
     filter.address(erc20).event_signature(Transfer::SIGNATURE_HASH).topic2(to.into_word())
   }
@@ -78,32 +84,35 @@ impl Erc20 {
   /// Yield the top-level transfer for the specified transaction (if one exists).
   ///
   /// The passed-in logs MUST be the logs for this transaction. The logs MUST be filtered to the
-  /// `Transfer` events of the intended token(s) and the intended `to` transferred to. These
+  /// `Transfer` events of the intended token and the intended `to` transferred to. These
   /// properties are completely unchecked and assumed to be the case.
   ///
   /// This does NOT yield THE top-level transfer. If multiple `Transfer` events have identical
-  /// structure to the top-level transfer call, the earliest `Transfer` event present in the logs
+  /// structure to the top-level transfer call, the first `Transfer` event present in the logs is
-  /// is considered the top-level transfer.
+  /// considered the top-level transfer.
   // Yielding THE top-level transfer would require tracing the transaction execution and isn't
   // worth the effort.
-  pub async fn top_level_transfer(
+  async fn top_level_transfer(
-    provider: impl AsRef<RootProvider<SimpleRequest>>,
+    provider: &RootProvider<SimpleRequest>,
+    erc20: Address,
     transaction_hash: [u8; 32],
-    mut transfer_logs: Vec<impl Borrow<Log>>,
+    transfer_logs: &[Log],
   ) -> Result<Option<TopLevelTransfer>, RpcError<TransportErrorKind>> {
     // Fetch the transaction
     let transaction =
-      provider.as_ref().get_transaction_by_hash(transaction_hash.into()).await?.ok_or_else(
+      provider.get_transaction_by_hash(transaction_hash.into()).await?.ok_or_else(|| {
-        || {
+        TransportErrorKind::Custom(
-          TransportErrorKind::Custom(
+          "node didn't have the transaction which emitted a log it had".to_string().into(),
-            "node didn't have the transaction which emitted a log it had".to_string().into(),
+        )
-          )
+      })?;
-        },
+
-      )?;
+    // If this transaction didn't call this ERC20 at a top-level, return
+    if transaction.inner.to() != Some(erc20) {
+      return Ok(None);
+    }
 
-    // If this is a top-level call...
     // Don't validate the encoding as this can't be re-encoded to an identical bytestring due
-    // to the `InInstruction` appended after the call itself
+    // to the additional data appended after the call itself
     let Ok(call) = IERC20Calls::abi_decode(transaction.inner.input(), false) else {
       return Ok(None);
     };
@@ -116,21 +125,12 @@ impl Erc20 {
       _ => return Ok(None),
     };
 
-    // Sort the logs to ensure the the earliest logs are first
-    transfer_logs.sort_by_key(|log| log.borrow().log_index);
     // Find the log for this top-level transfer
     for log in transfer_logs {
-      // Check the log is for the called contract
-      // This handles the edge case where we're checking if transfers of token X were top-level and
-      // a transfer of token Y (with equivalent structure) was top-level
-      if Some(log.borrow().address()) != transaction.inner.to() {
-        continue;
-      }
-
       // Since the caller is responsible for filtering these to `Transfer` events, we can assume
       // this is a non-compliant ERC20 or an error with the logs fetched. We assume ERC20
       // compliance here, making this an RPC error
-      let log = log.borrow().log_decode::<Transfer>().map_err(|_| {
+      let log = log.log_decode::<Transfer>().map_err(|_| {
         TransportErrorKind::Custom("log didn't include a valid transfer event".to_string().into())
       })?;
 
@@ -158,8 +158,8 @@ impl Erc20 {
           ) => Vec::from(inInstruction),
         }
       } else {
-        // We don't error here so this transfer is propagated up the stack, even without the
+        // If there was no additional data appended, use an empty Vec (which has no data)
-        // InInstruction. In practice, Serai should acknowledge this and return it to the sender
+        // This has a slight information loss in that it's None -> Some(vec![]), but it's fine
         vec![]
       };
 
@@ -177,69 +177,76 @@ impl Erc20 {
 
   /// Fetch all top-level transfers to the specified address for this token.
   ///
-  /// The result of this function is unordered.
+  /// The `transfers` in the result are unordered. The `logs` are sorted by index.
   pub async fn top_level_transfers_unordered(
-    &self,
+    provider: &RootProvider<SimpleRequest>,
     from_block: u64,
     to_block: u64,
+    erc20: Address,
     to: Address,
-  ) -> Result<Vec<TopLevelTransfer>, RpcError<TransportErrorKind>> {
+  ) -> Result<TopLevelTransfers, RpcError<TransportErrorKind>> {
-    // Get all transfers within these blocks
+    let mut logs = {
-    let logs = self
+      // Get all transfers within these blocks
-      .provider
+      let logs = provider.get_logs(&Self::transfer_filter(from_block, to_block, erc20, to)).await?;
-      .get_logs(&Self::transfer_filter(from_block, to_block, self.address, to))
-      .await?;
 
-    // The logs, indexed by their transactions
+      // The logs, indexed by their transactions
-    let mut transaction_logs = HashMap::new();
+      let mut transaction_logs = HashMap::new();
-    // Index the logs by their transactions
+      // Index the logs by their transactions
-    for log in logs {
+      for log in logs {
-      // Double check the address which emitted this log
+        // Double check the address which emitted this log
-      if log.address() != self.address {
+        if log.address() != erc20 {
-        Err(TransportErrorKind::Custom(
+          Err(TransportErrorKind::Custom(
-          "node returned logs for a different address than requested".to_string().into(),
+            "node returned logs for a different address than requested".to_string().into(),
-        ))?;
+          ))?;
-      }
+        }
-      // Double check the event signature for this log
+        // Double check the event signature for this log
-      if log.topics().first() != Some(&Transfer::SIGNATURE_HASH) {
+        if log.topics().first() != Some(&Transfer::SIGNATURE_HASH) {
-        Err(TransportErrorKind::Custom(
+          Err(TransportErrorKind::Custom(
-          "node returned a log for a different topic than filtered to".to_string().into(),
+            "node returned a log for a different topic than filtered to".to_string().into(),
-        ))?;
+          ))?;
-      }
+        }
-      // Double check the `to` topic
+        // Double check the `to` topic
-      if log.topics().get(2) != Some(&to.into_word()) {
+        if log.topics().get(2) != Some(&to.into_word()) {
-        Err(TransportErrorKind::Custom(
+          Err(TransportErrorKind::Custom(
-          "node returned a transfer for a different `to` than filtered to".to_string().into(),
+            "node returned a transfer for a different `to` than filtered to".to_string().into(),
-        ))?;
+          ))?;
+        }
+
+        let tx_id = log
+          .transaction_hash
+          .ok_or_else(|| {
+            TransportErrorKind::Custom("log didn't specify its transaction hash".to_string().into())
+          })?
+          .0;
+
+        transaction_logs.entry(tx_id).or_insert_with(|| Vec::with_capacity(1)).push(log);
       }
 
-      let tx_id = log
+      transaction_logs
-        .transaction_hash
+    };
-        .ok_or_else(|| {
-          TransportErrorKind::Custom("log didn't specify its transaction hash".to_string().into())
-        })?
-        .0;
 
-      transaction_logs.entry(tx_id).or_insert_with(|| Vec::with_capacity(1)).push(log);
+    let mut transfers = vec![];
-    }
+    {
+      // Use `FuturesUnordered` so these RPC calls run in parallel
+      let mut futures = FuturesUnordered::new();
+      for (tx_id, transfer_logs) in &mut logs {
+        // Sort the logs to ensure the the earliest logs are first
+        transfer_logs.sort_by_key(|log| log.log_index);
+        futures.push(Self::top_level_transfer(provider, erc20, *tx_id, transfer_logs));
+      }
 
-    // Use `FuturesUnordered` so these RPC calls run in parallel
+      while let Some(transfer) = futures.next().await {
-    let mut futures = FuturesUnordered::new();
+        match transfer {
-    for (tx_id, transfer_logs) in transaction_logs {
+          // Top-level transfer
-      futures.push(Self::top_level_transfer(&self.provider, tx_id, transfer_logs));
+          Ok(Some(transfer)) => transfers.push(transfer),
-    }
+          // Not a top-level transfer
-
+          Ok(None) => continue,
-    let mut top_level_transfers = vec![];
+          // Failed to get this transaction's information so abort
-    while let Some(top_level_transfer) = futures.next().await {
+          Err(e) => Err(e)?,
-      match top_level_transfer {
+        }
-        // Top-level transfer
-        Ok(Some(top_level_transfer)) => top_level_transfers.push(top_level_transfer),
-        // Not a top-level transfer
-        Ok(None) => continue,
-        // Failed to get this transaction's information so abort
-        Err(e) => Err(e)?,
       }
     }
-    Ok(top_level_transfers)
+
+    Ok(TopLevelTransfers { logs, transfers })
   }
 }

processor/ethereum/primitives/src/lib.rs

@@ -14,7 +14,7 @@ mod borsh;
 pub use borsh::*;
 
 /// An index of a log within a block.
-#[derive(Clone, Copy, PartialEq, Eq, Debug, BorshSerialize, BorshDeserialize)]
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, BorshSerialize, BorshDeserialize)]
 #[borsh(crate = "::borsh")]
 pub struct LogIndex {
   /// The hash of the block which produced this log.

processor/ethereum/router/src/lib.rs

@@ -29,7 +29,7 @@ use serai_client::{
 use ethereum_primitives::LogIndex;
 use ethereum_schnorr::{PublicKey, Signature};
 use ethereum_deployer::Deployer;
-use erc20::{Transfer, Erc20};
+use erc20::{Transfer, TopLevelTransfer, TopLevelTransfers, Erc20};
 
 use futures_util::stream::{StreamExt, FuturesUnordered};
 
@@ -451,35 +451,66 @@ impl Router {
     }
   }
 
-  /// Fetch the `InInstruction`s emitted by the Router from this block.
+  /// Fetch the `InInstruction`s for the Router for the specified inclusive range of blocks.
+  ///
+  /// This includes all `InInstruction` events from the Router and all top-level transfers to the
+  /// Router.
   ///
   /// This is not guaranteed to return them in any order.
   pub async fn in_instructions_unordered(
     &self,
     from_block: u64,
     to_block: u64,
-    allowed_tokens: &HashSet<Address>,
+    allowed_erc20s: &HashSet<Address>,
   ) -> Result<Vec<InInstruction>, RpcError<TransportErrorKind>> {
     // The InInstruction events for this block
-    let logs = {
+    let in_instruction_logs = {
       let filter = Filter::new().from_block(from_block).to_block(to_block).address(self.address);
       let filter = filter.event_signature(InInstructionEvent::SIGNATURE_HASH);
       self.provider.get_logs(&filter).await?
     };
 
-    let mut in_instructions = Vec::with_capacity(logs.len());
+    // Define the Vec for the result now that we have the logs as a size hint
-    /*
+    let mut in_instructions = Vec::with_capacity(in_instruction_logs.len());
-      We check that for all InInstructions for ERC20s emitted, a corresponding transfer occurred.
-      On this initial loop, we just queue the ERC20 InInstructions for later verification.
 
-      We don't do this for ETH as it'd require tracing the transaction, which is non-trivial. It
+    // Handle the top-level transfers for this block
-      also isn't necessary as all of this is solely defense in depth.
+    let mut justifying_erc20_transfer_logs = HashSet::new();
-    */
+    let erc20_transfer_logs = {
-    let mut erc20s = HashSet::new();
+      let mut transfers = FuturesUnordered::new();
-    let mut erc20_transfer_logs = FuturesUnordered::new();
+      for erc20 in allowed_erc20s {
-    let mut erc20_transactions = HashSet::new();
+        transfers.push(async move {
-    let mut erc20_in_instructions = vec![];
+          (
-    for log in logs {
+            erc20,
+            Erc20::top_level_transfers_unordered(
+              &self.provider,
+              from_block,
+              to_block,
+              *erc20,
+              self.address,
+            )
+            .await,
+          )
+        });
+      }
+
+      let mut logs = HashMap::with_capacity(allowed_erc20s.len());
+      while let Some((token, transfers)) = transfers.next().await {
+        let TopLevelTransfers { logs: token_logs, transfers } = transfers?;
+        logs.insert(token, token_logs);
+        // Map the top-level transfer to an InInstruction
+        for transfer in transfers {
+          let TopLevelTransfer { id, transaction_hash, from, amount, data } = transfer;
+          justifying_erc20_transfer_logs.insert(transfer.id);
+          let in_instruction =
+            InInstruction { id, transaction_hash, from, coin: Coin::Erc20(*token), amount, data };
+          in_instructions.push(in_instruction);
+        }
+      }
+      logs
+    };
+
+    // Now handle the InInstruction events
+    for log in in_instruction_logs {
       // Double check the address which emitted this log
       if log.address() != self.address {
         Err(TransportErrorKind::Custom(
@@ -491,18 +522,22 @@ impl Router {
         continue;
       }
 
-      let id = LogIndex {
+      let log_index = |log: &Log| -> Result<LogIndex, TransportErrorKind> {
-        block_hash: log
+        Ok(LogIndex {
-          .block_hash
+          block_hash: log
-          .ok_or_else(|| {
+            .block_hash
-            TransportErrorKind::Custom("log didn't have its block hash set".to_string().into())
+            .ok_or_else(|| {
-          })?
+              TransportErrorKind::Custom("log didn't have its block hash set".to_string().into())
-          .into(),
+            })?
-        index_within_block: log.log_index.ok_or_else(|| {
+            .into(),
-          TransportErrorKind::Custom("log didn't have its index set".to_string().into())
+          index_within_block: log.log_index.ok_or_else(|| {
-        })?,
+            TransportErrorKind::Custom("log didn't have its index set".to_string().into())
+          })?,
+        })
       };
 
+      let id = log_index(&log)?;
+
       let transaction_hash = log.transaction_hash.ok_or_else(|| {
         TransportErrorKind::Custom("log didn't have its transaction hash set".to_string().into())
       })?;
@@ -530,135 +565,57 @@ impl Router {
       };
 
       match coin {
-        Coin::Ether => in_instructions.push(in_instruction),
+        Coin::Ether => {}
         Coin::Erc20(token) => {
-          if !allowed_tokens.contains(&token) {
+          // Check this is an allowed token
+          if !allowed_erc20s.contains(&token) {
             continue;
           }
 
-          // Fetch the ERC20 transfer events necessary to verify this InInstruction has a matching
+          /*
-          // transfer
+            We check that for all InInstructions for ERC20s emitted, a corresponding transfer
-          if !erc20s.contains(&token) {
+            occurred.
-            erc20s.insert(token);
-            erc20_transfer_logs.push(async move {
-              let filter = Erc20::transfer_filter(from_block, to_block, token, self.address);
-              self.provider.get_logs(&filter).await.map(|logs| (token, logs))
-            });
-          }
-          erc20_transactions.insert(transaction_hash);
-          erc20_in_instructions.push((transaction_hash, in_instruction))
-        }
-      }
-    }
 
-    // Collect the ERC20 transfer logs
+            We don't do this for ETH as it'd require tracing the transaction, which is non-trivial.
-    let erc20_transfer_logs = {
+            It also isn't necessary as all of this is solely defense in depth.
-      let mut collected = HashMap::with_capacity(erc20s.len());
+          */
-      while let Some(token_and_logs) = erc20_transfer_logs.next().await {
+          let mut justified = false;
-        let (token, logs) = token_and_logs?;
+          // These logs are returned from `top_level_transfers_unordered` and we don't require any
-        collected.insert(token, logs);
+          // ordering of them
-      }
+          for log in erc20_transfer_logs[&token].get(&transaction_hash).unwrap_or(&vec![]) {
-      collected
+            let log_index = log_index(log)?;
-    };
 
-    /*
+            // Ensure we didn't already use this transfer to justify a distinct InInstruction
-      For each transaction, it may have a top-level ERC20 transfer. That top-level transfer won't
+            if justifying_erc20_transfer_logs.contains(&log_index) {
-      be the transfer caused by the call to `inInstruction`, so we shouldn't consider it
+              continue;
-      justification for this `InInstruction` event.
+            }
-
+
-      Fetch all top-level transfers here so we can ignore them.
+            // Check if this log is from the token we expected to be transferred
-    */
+            if log.address() != Address::from(in_instruction.coin) {
-    let mut erc20_top_level_transfers = FuturesUnordered::new();
+              continue;
-    let mut transaction_transfer_logs = HashMap::new();
+            }
-    for transaction in erc20_transactions {
+            // Check if this is a transfer log
-      // Filter to the logs for this specific transaction
+            if log.topics().first() != Some(&Transfer::SIGNATURE_HASH) {
-      let logs = erc20_transfer_logs
+              continue;
-        .values()
+            }
-        .flat_map(|logs_per_token| logs_per_token.iter())
+            let Ok(transfer) = Transfer::decode_log(&log.inner.clone(), true) else { continue };
-        .filter_map(|log| {
+            // Check if this aligns with the InInstruction
-          let log_transaction_hash = log.transaction_hash.ok_or_else(|| {
+            if (transfer.from == in_instruction.from) &&
-            TransportErrorKind::Custom(
+              (transfer.to == self.address) &&
-              "log didn't have its transaction hash set".to_string().into(),
+              (transfer.value == in_instruction.amount)
-            )
+            {
-          });
+              justifying_erc20_transfer_logs.insert(log_index);
-          match log_transaction_hash {
+              justified = true;
-            Ok(log_transaction_hash) => {
+              break;
-              if log_transaction_hash == transaction {
-                Some(Ok(log))
-              } else {
-                None
-              }
             }
-            Err(e) => Some(Err(e)),
           }
-        })
+          if !justified {
-        .collect::<Result<Vec<_>, _>>()?;
+            // This is an exploit, a non-conforming ERC20, or an invalid connection
-
+            Err(TransportErrorKind::Custom(
-      // Find the top-level transfer
+              "ERC20 InInstruction with no matching transfer log".to_string().into(),
-      erc20_top_level_transfers.push(Erc20::top_level_transfer(
+            ))?;
-        &self.provider,
+          }
-        transaction,
-        logs.clone(),
-      ));
-      // Keep the transaction-indexed logs for the actual justifying
-      transaction_transfer_logs.insert(transaction, logs);
-    }
-
-    /*
-      In order to prevent a single transfer from being used to justify multiple distinct
-      InInstructions, we insert the transfer's log index into this HashSet.
-    */
-    let mut already_used_to_justify = HashSet::new();
-
-    // Collect the top-level transfers
-    while let Some(erc20_top_level_transfer) = erc20_top_level_transfers.next().await {
-      let erc20_top_level_transfer = erc20_top_level_transfer?;
-      // If this transaction had a top-level transfer...
-      if let Some(erc20_top_level_transfer) = erc20_top_level_transfer {
-        // Mark this log index as used so it isn't used again
-        already_used_to_justify.insert(erc20_top_level_transfer.id.index_within_block);
-      }
-    }
-
-    // Now, for each ERC20 InInstruction, find a justifying transfer log
-    for (transaction_hash, in_instruction) in erc20_in_instructions {
-      let mut justified = false;
-      for log in &transaction_transfer_logs[&transaction_hash] {
-        let log_index = log.log_index.ok_or_else(|| {
-          TransportErrorKind::Custom(
-            "log in transaction receipt didn't have its log index set".to_string().into(),
-          )
-        })?;
-
-        // Ensure we didn't already use this transfer to check a distinct InInstruction event
-        if already_used_to_justify.contains(&log_index) {
-          continue;
         }
-
-        // Check if this log is from the token we expected to be transferred
-        if log.address() != Address::from(in_instruction.coin) {
-          continue;
-        }
-        // Check if this is a transfer log
-        if log.topics().first() != Some(&Transfer::SIGNATURE_HASH) {
-          continue;
-        }
-        let Ok(transfer) = Transfer::decode_log(&log.inner.clone(), true) else { continue };
-        // Check if this aligns with the InInstruction
-        if (transfer.from == in_instruction.from) &&
-          (transfer.to == self.address) &&
-          (transfer.value == in_instruction.amount)
-        {
-          already_used_to_justify.insert(log_index);
-          justified = true;
-          break;
-        }
-      }
-      if !justified {
-        // This is an exploit, a non-conforming ERC20, or an invalid connection
-        Err(TransportErrorKind::Custom(
-          "ERC20 InInstruction with no matching transfer log".to_string().into(),
-        ))?;
       }
       in_instructions.push(in_instruction);
     }
@@ -666,7 +623,7 @@ impl Router {
     Ok(in_instructions)
   }
 
-  /// Fetch the executed actions from this block.
+  /// Fetch the executed actions for the specified range of blocks.
   pub async fn executed(
     &self,
     from_block: u64,

processor/ethereum/router/src/tests/erc20.rs

@@ -1,13 +1,11 @@
-use alloy_core::primitives::{hex, Address, U256, Bytes, TxKind, PrimitiveSignature};
+use alloy_core::primitives::{hex, Address, U256, Bytes, TxKind};
 use alloy_sol_types::{SolValue, SolCall};
 
-use alloy_consensus::{TxLegacy, SignableTransaction, Signed};
+use alloy_consensus::TxLegacy;
 
 use alloy_rpc_types_eth::{TransactionInput, TransactionRequest};
 use alloy_provider::Provider;
 
-use ethereum_primitives::keccak256;
-
 use crate::tests::Test;
 
 #[rustfmt::skip]

processor/ethereum/router/src/tests/mod.rs

@@ -5,13 +5,12 @@ use rand_core::{RngCore, OsRng};
 use group::ff::Field;
 use k256::{Scalar, ProjectivePoint};
 
-use alloy_core::primitives::{Address, U256, TxKind};
+use alloy_core::primitives::{Address, U256};
-use alloy_sol_types::SolCall;
+use alloy_sol_types::{SolCall, SolEvent};
 
-use alloy_consensus::TxLegacy;
+use alloy_consensus::{TxLegacy, Signed};
 
-#[rustfmt::skip]
+use alloy_rpc_types_eth::{BlockNumberOrTag, TransactionInput, TransactionRequest};
-use alloy_rpc_types_eth::{BlockNumberOrTag, TransactionInput, TransactionRequest, TransactionReceipt};
 use alloy_simple_request_transport::SimpleRequest;
 use alloy_rpc_client::ClientBuilder;
 use alloy_provider::{Provider, RootProvider};
@@ -262,6 +261,56 @@ impl Test {
     (coin, amount, shorthand, tx)
   }
 
+  async fn publish_in_instruction_tx(
+    &self,
+    tx: Signed<TxLegacy>,
+    coin: Coin,
+    amount: U256,
+    shorthand: &Shorthand,
+  ) {
+    let receipt = ethereum_test_primitives::publish_tx(&self.provider, tx.clone()).await;
+    assert!(receipt.status());
+
+    let block = receipt.block_number.unwrap();
+
+    if matches!(coin, Coin::Erc20(_)) {
+      // If we don't whitelist this token, we shouldn't be yielded an InInstruction
+      let in_instructions =
+        self.router.in_instructions_unordered(block, block, &HashSet::new()).await.unwrap();
+      assert!(in_instructions.is_empty());
+    }
+
+    let in_instructions = self
+      .router
+      .in_instructions_unordered(
+        block,
+        block,
+        &if let Coin::Erc20(token) = coin { HashSet::from([token]) } else { HashSet::new() },
+      )
+      .await
+      .unwrap();
+    assert_eq!(in_instructions.len(), 1);
+
+    let in_instruction_log_index = receipt.inner.logs().iter().find_map(|log| {
+      (log.topics().first() == Some(&crate::InInstructionEvent::SIGNATURE_HASH))
+        .then(|| log.log_index.unwrap())
+    });
+    // If this isn't an InInstruction event, it'll be a top-level transfer event
+    let log_index = in_instruction_log_index.unwrap_or(0);
+
+    assert_eq!(
+      in_instructions[0],
+      InInstruction {
+        id: LogIndex { block_hash: *receipt.block_hash.unwrap(), index_within_block: log_index },
+        transaction_hash: **tx.hash(),
+        from: tx.recover_signer().unwrap(),
+        coin,
+        amount,
+        data: shorthand.encode(),
+      }
+    );
+  }
+
   fn escape_hatch_tx(&self, escape_to: Address) -> TxLegacy {
     let msg = Router::escape_hatch_message(self.chain_id, self.state.next_nonce, escape_to);
     let sig = sign(self.state.key.unwrap(), &msg);
@@ -344,31 +393,11 @@ async fn test_eth_in_instruction() {
   }
 
   let tx = ethereum_primitives::deterministically_sign(tx);
-  let receipt = ethereum_test_primitives::publish_tx(&test.provider, tx.clone()).await;
+  test.publish_in_instruction_tx(tx, coin, amount, &shorthand).await;
-  assert!(receipt.status());
-
-  let block = receipt.block_number.unwrap();
-  let in_instructions =
-    test.router.in_instructions_unordered(block, block, &HashSet::new()).await.unwrap();
-  assert_eq!(in_instructions.len(), 1);
-  assert_eq!(
-    in_instructions[0],
-    InInstruction {
-      id: LogIndex {
-        block_hash: *receipt.block_hash.unwrap(),
-        index_within_block: receipt.inner.logs()[0].log_index.unwrap(),
-      },
-      transaction_hash: **tx.hash(),
-      from: tx.recover_signer().unwrap(),
-      coin,
-      amount,
-      data: shorthand.encode(),
-    }
-  );
 }
 
 #[tokio::test]
-async fn test_erc20_in_instruction() {
+async fn test_erc20_router_in_instruction() {
   let mut test = Test::new().await;
   test.confirm_next_serai_key().await;
 
@@ -404,39 +433,28 @@ async fn test_erc20_in_instruction() {
     erc20.mint(&test, signer, amount).await;
     erc20.approve(&test, signer, test.router.address(), amount).await;
   }
-  let receipt = ethereum_test_primitives::publish_tx(&test.provider, tx.clone()).await;
-  assert!(receipt.status());
 
-  let block = receipt.block_number.unwrap();
+  test.publish_in_instruction_tx(tx, coin, amount, &shorthand).await;
+}
 
-  // If we don't whitelist this token, we shouldn't be yielded an InInstruction
+#[tokio::test]
-  {
+async fn test_erc20_top_level_transfer_in_instruction() {
-    let in_instructions =
+  let mut test = Test::new().await;
-      test.router.in_instructions_unordered(block, block, &HashSet::new()).await.unwrap();
+  test.confirm_next_serai_key().await;
-    assert!(in_instructions.is_empty());
-  }
 
-  let in_instructions = test
+  let erc20 = Erc20::deploy(&test).await;
-    .router
+
-    .in_instructions_unordered(block, block, &HashSet::from([coin.into()]))
+  let coin = Coin::Erc20(erc20.address());
-    .await
+  let amount = U256::from(1);
-    .unwrap();
+  let shorthand = Test::in_instruction();
-  assert_eq!(in_instructions.len(), 1);
+
-  assert_eq!(
+  let mut tx = test.router.in_instruction(coin, amount, &shorthand);
-    in_instructions[0],
+  tx.gas_price = 100_000_000_000u128;
-    InInstruction {
+  tx.gas_limit = 1_000_000;
-      id: LogIndex {
+
-        block_hash: *receipt.block_hash.unwrap(),
+  let tx = ethereum_primitives::deterministically_sign(tx);
-        // First is the Transfer log, then the InInstruction log
+  erc20.mint(&test, tx.recover_signer().unwrap(), amount).await;
-        index_within_block: receipt.inner.logs()[1].log_index.unwrap(),
+  test.publish_in_instruction_tx(tx, coin, amount, &shorthand).await;
-      },
-      transaction_hash: **tx.hash(),
-      from: tx.recover_signer().unwrap(),
-      coin,
-      amount,
-      data: shorthand.encode(),
-    }
-  );
 }
 
 #[tokio::test]

processor/ethereum/src/rpc.rs

@@ -16,9 +16,7 @@ use serai_db::Db;
 use scanner::ScannerFeed;
 
 use ethereum_schnorr::PublicKey;
-use ethereum_erc20::{TopLevelTransfer, Erc20};
+use ethereum_router::{InInstruction as EthereumInInstruction, Executed, Router};
-#[rustfmt::skip]
-use ethereum_router::{Coin as EthereumCoin, InInstruction as EthereumInInstruction, Executed, Router};
 
 use crate::{
   TOKENS, ETHER_DUST, DAI_DUST, InitialSeraiKey,
@@ -158,31 +156,13 @@ impl<D: Db> ScannerFeed for Rpc<D> {
       };
 
       async fn sync_block(
-        provider: Arc<RootProvider<SimpleRequest>>,
         router: Router,
         block: Header,
       ) -> Result<(Vec<EthereumInInstruction>, Vec<Executed>), RpcError<TransportErrorKind>> {
-        let mut instructions = router
+        let instructions = router
           .in_instructions_unordered(block.number, block.number, &HashSet::from(TOKENS))
           .await?;
 
-        for token in TOKENS {
-          for TopLevelTransfer { id, transaction_hash, from, amount, data } in
-            Erc20::new(provider.clone(), token)
-              .top_level_transfers_unordered(block.number, block.number, router.address())
-              .await?
-          {
-            instructions.push(EthereumInInstruction {
-              id,
-              transaction_hash,
-              from,
-              coin: EthereumCoin::Erc20(token),
-              amount,
-              data,
-            });
-          }
-        }
-
         let executed = router.executed(block.number, block.number).await?;
 
         Ok((instructions, executed))
@@ -214,7 +194,7 @@ impl<D: Db> ScannerFeed for Rpc<D> {
         to_check = *to_check_block.parent_hash;
 
         // Spawn a task to sync this block
-        join_set.spawn(sync_block(self.provider.clone(), router.clone(), to_check_block));
+        join_set.spawn(sync_block(router.clone(), to_check_block));
       }
 
       let mut instructions = vec![];