Increase network limits (#2796)

Fix max packet sizes

Fix max_payload_size function

Add merge block test

Fix max size calculation; fix up test

Clear comments

Add a payload_size_function

Use safe arith for payload calculation

Return an error if block too big in block production

Separate test to check if block is over limit

consensus/types/src/eth_spec.rs

@@ -210,6 +210,11 @@ pub trait EthSpec: 'static + Default + Sync + Send + Clone + Debug + PartialEq +
         Self::MaxTransactionsPerPayload::to_usize()
     }
 
+    /// Returns the `MAX_EXTRA_DATA_BYTES` constant for this specification.
+    fn max_extra_data_bytes() -> usize {
+        Self::MaxExtraDataBytes::to_usize()
+    }
+
     /// Returns the `BYTES_PER_LOGS_BLOOM` constant for this specification.
     fn bytes_per_logs_bloom() -> usize {
         Self::BytesPerLogsBloom::to_usize()

consensus/types/src/execution_payload.rs

@@ -1,5 +1,7 @@
 use crate::{test_utils::TestRandom, *};
+use safe_arith::{ArithError, SafeArith};
 use serde_derive::{Deserialize, Serialize};
+use ssz::Encode;
 use ssz_derive::{Decode, Encode};
 use test_random_derive::TestRandom;
 use tree_hash_derive::TreeHash;
@@ -57,4 +59,51 @@ impl<T: EthSpec> ExecutionPayload<T> {
             transactions: VariableList::empty(),
         }
     }
+
+    /// Returns the ssz size of `self`.
+    pub fn payload_size(&self) -> Result<usize, ArithError> {
+        let mut tx_size = ssz::BYTES_PER_LENGTH_OFFSET.safe_mul(self.transactions.len())?;
+        for tx in self.transactions.iter() {
+            tx_size.safe_add_assign(tx.len())?;
+        }
+        Self::empty()
+            .as_ssz_bytes()
+            .len()
+            .safe_add(<u8 as Encode>::ssz_fixed_len().safe_mul(self.extra_data.len())?)?
+            .safe_add(tx_size)
+    }
+
+    #[allow(clippy::integer_arithmetic)]
+    /// Returns the maximum size of an execution payload.
+    pub fn max_execution_payload_size() -> usize {
+        // Fixed part
+        Self::empty().as_ssz_bytes().len()
+        // Max size of variable length `extra_data` field
+        + (T::max_extra_data_bytes() * <u8 as Encode>::ssz_fixed_len())
+        // Max size of variable length `transactions` field
+        + (T::max_transactions_per_payload() * (ssz::BYTES_PER_LENGTH_OFFSET + T::max_bytes_per_transaction()))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_payload_size() {
+        let mut payload = ExecutionPayload::<crate::MainnetEthSpec>::empty();
+
+        assert_eq!(
+            payload.as_ssz_bytes().len(),
+            payload.payload_size().unwrap()
+        );
+
+        payload.extra_data = VariableList::from(vec![42; 16]);
+        payload.transactions = VariableList::from(vec![VariableList::from(vec![42; 42])]);
+
+        assert_eq!(
+            payload.as_ssz_bytes().len(),
+            payload.payload_size().unwrap()
+        );
+    }
 }