Merge pull request #42 from gattaca-com/duplicated_block_hash

Duplicated block hash

crates/api/src/builder/api.rs

@@ -228,14 +228,32 @@ where
             .await?;
 
         // Handle duplicates.
-        api.check_for_duplicate_block_hash(
-            &block_hash,
-            payload.slot(),
-            payload.parent_hash(),
-            payload.proposer_public_key(),
-            &request_id,
-        )
-        .await?;
+        if let Err(err) = api
+            .check_for_duplicate_block_hash(
+                &block_hash,
+                payload.slot(),
+                payload.parent_hash(),
+                payload.proposer_public_key(),
+                &request_id,
+            )
+            .await
+        {
+            match err {
+                BuilderApiError::DuplicateBlockHash { block_hash } => {
+                    // We dont return the error here as we want to continue processing the request.
+                    // This mitigates the risk of someone sending an invalid payload
+                    // with a valid header, which would block subsequent submissions with the same
+                    // header and valid payload.
+                    debug!(
+                        request_id = %request_id,
+                        block_hash = ?block_hash,
+                        builder_pub_key = ?payload.builder_public_key(),
+                        "block hash already seen"
+                    );
+                }
+                _ => return Err(err),
+            }
+        }
 
         // Verify the payload value is above the floor bid
         let floor_bid_value = api
@@ -432,14 +450,32 @@ where
         }
 
         // Handle duplicates.
-        api.check_for_duplicate_block_hash(
-            &block_hash,
-            payload.slot(),
-            payload.parent_hash(),
-            payload.proposer_public_key(),
-            &request_id,
-        )
-        .await?;
+        if let Err(err) = api
+            .check_for_duplicate_block_hash(
+                &block_hash,
+                payload.slot(),
+                payload.parent_hash(),
+                payload.proposer_public_key(),
+                &request_id,
+            )
+            .await
+        {
+            match err {
+                BuilderApiError::DuplicateBlockHash { block_hash } => {
+                    // We dont return the error here as we want to continue processing the request.
+                    // This mitigates the risk of someone sending an invalid payload
+                    // with a valid header, which would block subsequent submissions with the same
+                    // header and valid payload.
+                    debug!(
+                        request_id = %request_id,
+                        block_hash = ?block_hash,
+                        builder_pub_key = ?payload.builder_public_key(),
+                        "block hash already seen"
+                    );
+                }
+                _ => return Err(err),
+            }
+        }
 
         // Discard any OptimisticV2 submissions if the proposer has censoring enabled
         if next_duty.entry.preferences.censoring {