feat: tx validation for legacy txs

crates/core/src/types/constants.rs

@@ -0,0 +1,9 @@
+// Transaction costs
+pub const TX_BASE_COST: u64 = 21000;
+pub const TX_DATA_COST_PER_NON_ZERO: u64 = 16;
+pub const TX_DATA_COST_PER_ZERO: u64 = 4;
+pub const TX_CREATE_COST: u64 = 32000;
+pub const TX_ACCESS_LIST_ADDRESS_COST: u64 = 2400;
+pub const TX_ACCESS_LIST_STORAGE_KEY_COST: u64 = 1900;
+pub const MAX_CODE_SIZE: usize = 0x6000;
+pub const GAS_INIT_CODE_WORD_COST: u64 = 2;

crates/core/src/types/mod.rs

@@ -1,13 +1,17 @@
 mod account;
 mod block;
+mod constants;
 mod engine;
 mod genesis;
 mod receipt;
 mod transaction;
+mod utils;
 
 pub use account::*;
 pub use block::*;
+pub use constants::*;
 pub use engine::*;
 pub use genesis::*;
 pub use receipt::*;
 pub use transaction::*;
+pub use utils::*;

crates/core/src/types/transaction.rs

@@ -11,6 +11,11 @@ use crate::rlp::{
     structs::{Decoder, Encoder},
 };
 
+use super::{
+    ceil32, GAS_INIT_CODE_WORD_COST, MAX_CODE_SIZE, TX_ACCESS_LIST_ADDRESS_COST, TX_BASE_COST,
+    TX_CREATE_COST, TX_DATA_COST_PER_NON_ZERO, TX_DATA_COST_PER_ZERO,
+};
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum Transaction {
     LegacyTransaction(LegacyTransaction),
@@ -442,6 +447,37 @@ fn recover_address(
     Address::from_slice(&hash[12..])
 }
 
+/// Verifies a transaction.
+// reference: https://github.com/ethereum/execution-specs/blob/c854868f4abf2ab0c3e8790d4c40607e0d251147/src/ethereum/shanghai/fork.py#L678
+pub fn validate_transaction(tx: &Transaction) -> bool {
+    calculate_intrinsic_cost(tx) <= tx.gas_limit()
+        && !(matches!(tx.to(), TxKind::Create) && tx.data().len() > 2 * MAX_CODE_SIZE)
+}
+
+///  Calculates the gas that is charged before execution is started.
+fn calculate_intrinsic_cost(tx: &Transaction) -> u64 {
+    let data_cost = tx.data().iter().fold(0, |acc, byte| {
+        acc + if *byte == 0 {
+            TX_DATA_COST_PER_ZERO
+        } else {
+            TX_DATA_COST_PER_NON_ZERO
+        }
+    });
+    let create_cost = match tx.to() {
+        TxKind::Call(_) => 0,
+        TxKind::Create => TX_CREATE_COST + init_code_cost(tx.data().len() as u64),
+    };
+    let access_list_cost = tx.access_list().iter().fold(0, |acc, (_, keys)| {
+        acc + TX_ACCESS_LIST_ADDRESS_COST + keys.len() as u64 * TX_ACCESS_LIST_ADDRESS_COST
+    });
+    TX_BASE_COST + data_cost + create_cost + access_list_cost
+}
+
+/// Calculates the gas to be charged for the init code in a create transaction.
+fn init_code_cost(init_code_length: u64) -> u64 {
+    GAS_INIT_CODE_WORD_COST * ceil32(init_code_length) / 32
+}
+
 #[cfg(test)]
 mod tests {
     use crate::types::{compute_receipts_root, BlockBody, Receipt};
@@ -552,4 +588,12 @@ mod tests {
         };
         assert_eq!(tx, expected_tx);
     }
+
+    #[test]
+    fn validate_legacy_tx() {
+        let legacy_tx = LegacyTransaction::decode(&hex!("f86d80843baa0c4082f618946177843db3138ae69679a54b95cf345ed759450d870aa87bee538000808360306ba0151ccc02146b9b11adf516e6787b59acae3e76544fdcd75e77e67c6b598ce65da064c5dd5aae2fbb535830ebbdad0234975cd7ece3562013b63ea18cc0df6c97d4")).unwrap();
+        assert!(validate_transaction(&Transaction::LegacyTransaction(
+            legacy_tx
+        )))
+    }
 }

crates/core/src/types/utils.rs

@@ -0,0 +1,9 @@
+/// Converts a unsigned integer to the next closest multiple of 32
+pub fn ceil32(n: u64) -> u64 {
+    let rem = n % 32;
+    if rem == 0 {
+        n
+    } else {
+        n + 32 - rem
+    }
+}