From b40ce6f7f7ecba4f959d0d72a579f5a593aa9921 Mon Sep 17 00:00:00 2001
From: Dan Cline <6798349+Rjected@users.noreply.github.com>
Date: Fri, 5 May 2023 13:33:01 +0200
Subject: [PATCH] fix: correct effective_gas_price (#2573)

---
 crates/primitives/src/transaction/mod.rs   | 35 +++++++++++++++++++++-
 crates/rpc/rpc/src/eth/api/fees.rs         |  2 +-
 crates/rpc/rpc/src/eth/api/transactions.rs |  5 +---
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/crates/primitives/src/transaction/mod.rs b/crates/primitives/src/transaction/mod.rs
index acda972bf7..0cf9997fdd 100644
--- a/crates/primitives/src/transaction/mod.rs
+++ b/crates/primitives/src/transaction/mod.rs
@@ -369,7 +369,7 @@ impl Transaction {
     /// transactions is returned.
     ///
     /// If the `max_fee_per_gas` is less than the base fee, `None` returned.
-    pub fn effective_gas_price(&self, base_fee: Option<u64>) -> Option<u128> {
+    pub fn effective_gas_tip(&self, base_fee: Option<u64>) -> Option<u128> {
         if let Some(base_fee) = base_fee {
             let max_fee_per_gas = self.max_fee_per_gas();
             if max_fee_per_gas < base_fee as u128 {
@@ -400,6 +400,19 @@ impl Transaction {
         }
     }
 
+    /// Returns the effective gas price for the given base fee.
+    ///
+    /// If the transaction is a legacy or EIP2930 transaction, the gas price is returned.
+    pub fn effective_gas_price(&self, base_fee: Option<u64>) -> u128 {
+        let dynamic_tx = match self {
+            Transaction::Legacy(tx) => return tx.gas_price,
+            Transaction::Eip2930(tx) => return tx.gas_price,
+            Transaction::Eip1559(dynamic_tx) => dynamic_tx,
+        };
+
+        dynamic_tx.effective_gas_price(base_fee)
+    }
+
     /// Returns the effective miner gas tip cap (`gasTipCap`) for the given base fee.
     ///
     /// Returns `None` if the basefee is higher than the [Transaction::max_fee_per_gas].
@@ -633,6 +646,26 @@ impl Encodable for Transaction {
     }
 }
 
+impl TxEip1559 {
+    /// Returns the effective gas price for the given `base_fee`.
+    pub fn effective_gas_price(&self, base_fee: Option<u64>) -> u128 {
+        match base_fee {
+            None => self.max_fee_per_gas,
+            Some(base_fee) => {
+                // if the tip is greater than the max priority fee per gas, set it to the max
+                // priority fee per gas + base fee
+                let tip = self.max_fee_per_gas - base_fee as u128;
+                if tip > self.max_priority_fee_per_gas {
+                    self.max_priority_fee_per_gas + base_fee as u128
+                } else {
+                    // otherwise return the max fee per gas
+                    self.max_fee_per_gas
+                }
+            }
+        }
+    }
+}
+
 /// Whether or not the transaction is a contract creation.
 #[derive_arbitrary(compact, rlp)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default, Serialize, Deserialize)]
diff --git a/crates/rpc/rpc/src/eth/api/fees.rs b/crates/rpc/rpc/src/eth/api/fees.rs
index 5027a76432..ac5174e918 100644
--- a/crates/rpc/rpc/src/eth/api/fees.rs
+++ b/crates/rpc/rpc/src/eth/api/fees.rs
@@ -129,7 +129,7 @@ where
                 let mut sorter = Vec::with_capacity(transactions.len());
                 for transaction in transactions.iter() {
                     let reward = transaction
-                        .effective_gas_price(header.base_fee_per_gas)
+                        .effective_gas_tip(header.base_fee_per_gas)
                         .ok_or(InvalidTransactionError::FeeCapTooLow)?;
 
                     sorter.push(TxGasAndReward { gas_used: header.gas_used as u128, reward })
diff --git a/crates/rpc/rpc/src/eth/api/transactions.rs b/crates/rpc/rpc/src/eth/api/transactions.rs
index 7302d36866..000cf83e67 100644
--- a/crates/rpc/rpc/src/eth/api/transactions.rs
+++ b/crates/rpc/rpc/src/eth/api/transactions.rs
@@ -596,10 +596,7 @@ where
             gas_used: Some(U256::from(gas_used)),
             contract_address: None,
             logs: Vec::with_capacity(receipt.logs.len()),
-            effective_gas_price: transaction
-                .effective_gas_price(meta.base_fee)
-                .map(U128::from)
-                .unwrap_or(U128::ZERO),
+            effective_gas_price: U128::from(transaction.effective_gas_price(meta.base_fee)),
             transaction_type: tx.transaction.tx_type().into(),
             // TODO pre-byzantium receipts have a post-transaction state root
             state_root: None,