From c2419a51320ac2d098c3f349d6e80ab5f6b08cc3 Mon Sep 17 00:00:00 2001
From: Agnish Ghosh <iamagnix@gmail.com>
Date: Thu, 10 Oct 2024 00:26:01 +0530
Subject: [PATCH] add more extensive da checks

---
 beacon_chain/nimbus_beacon_node.nim | 33 ++++++++++++++++++-----------
 beacon_chain/sync/sync_manager.nim  |  7 +++---
 2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/beacon_chain/nimbus_beacon_node.nim b/beacon_chain/nimbus_beacon_node.nim
index bb7d6848e..9de1067a6 100644
--- a/beacon_chain/nimbus_beacon_node.nim
+++ b/beacon_chain/nimbus_beacon_node.nim
@@ -420,19 +420,28 @@ proc initFullNode(
                                                       localSubnetCount))
             accumulatedColumns = dataColumnQuarantine[].accumulateDataColumns(forkyBlck)
 
-          for ac in accumulatedColumns:
-            if ac notin localCustodyColumns:
-              # We don't have all the data columns for this block, so we have
-              # to put it in columnless quarantine.
-              if not quarantine[].addColumnless(dag.finalizedHead.slot, forkyBlck):
-                return err(VerifierError.UnviableFork)
-              else:
-                return err(VerifierError.MissingParent)
+          if accumulatedColumns.len == 0:
+            # We don't have all the data columns for this block, so we have
+            # to put it in columnless quarantine.
+            if not quarantine[].addColumnless(dag.finalizedHead.slot, forkyBlck):
+              return err(VerifierError.UnviableFork)
             else:
-              let data_columns = dataColumnQuarantine[].popDataColumns(forkyBlck.root, forkyBlck)
-              return await blockProcessor[].addBlock(MsgSource.gossip, signedBlock,
-                                        Opt.none(BlobSidecars), Opt.some(data_columns),
-                                        maybeFinalized = maybeFinalized)
+              return err(VerifierError.MissingParent)
+          elif supernode == true and accumulatedColumns.len >= localCustodyColumns.len div 2:
+            let data_columns = dataColumnQuarantine[].popDataColumns(forkyBlck.root, forkyBlck)
+            return await blockProcessor[].addBlock(MsgSource.gossip, signedBlock,
+                                      Opt.none(BlobSidecars), Opt.some(data_columns),
+                                      maybeFinalized = maybeFinalized)
+
+          elif supernode == false and accumulatedColumns.len <= localCustodyColumns.len div 2:
+            let data_columns = dataColumnQuarantine[].popDataColumns(forkyBlck.root, forkyBlck)
+            return await blockProcessor[].addBlock(MsgSource.gossip, signedBlock,
+                                      Opt.none(BlobSidecars), Opt.some(data_columns),
+                                      maybeFinalized = maybeFinalized)
+          else:
+            return await blockProcessor[].addBlock(MsgSource.gossip, signedBlock,
+                                      Opt.none(BlobSidecars), Opt.none(DataColumnSidecars),
+                                      maybeFinalized = maybeFinalized) 
         else:
           return await blockProcessor[].addBlock(MsgSource.gossip, signedBlock,
                                     Opt.none(BlobSidecars), Opt.none(DataColumnSidecars),
diff --git a/beacon_chain/sync/sync_manager.nim b/beacon_chain/sync/sync_manager.nim
index dad6d82a9..d8bf05935 100644
--- a/beacon_chain/sync/sync_manager.nim
+++ b/beacon_chain/sync/sync_manager.nim
@@ -360,11 +360,10 @@ func groupDataColumns*[T](req: SyncRequest[T],
         # The following data column sidecars, where they exist, MUST be sent in consecutive (slot, index) order.
         # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.3/specs/_features/eip7594/p2p-interface.md
         let header = forkyBlck.toSignedBeaconBlockHeader()
-        for column_idx in data_columns
-          if column_cursor >= data_columns.len:
-            return err("DataColumnSidecar: response too short")
+        for column_idx in 0..<data_columns.len:
           let data_column_sidecar = data_columns[column_cursor]
-          if data_column_sidecar.index != ColumnIndex column_idx
+          if data_column_sidecar.index != ColumnIndex column_idx:
+            return err("DataColumnSidecar: invalid index")
           if data_column_sidecar.signed_block_header != header:
             return err("DataColumnSidecar: unexpected signed_block_header")
           grouped[block_idx].add(data_column_sidecar)