return L1 blockhashes

matter-labs · Jul 18, 2024 · 49786ad · 49786ad
1 parent 1eca012
commit 49786ad
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Showing 2 changed files with 64 additions and 11 deletions.
diff --git a/crates/zksync/core/src/vm/runner.rs b/crates/zksync/core/src/vm/runner.rs
@@ -63,13 +63,29 @@ where
         PaymasterParams::default(),
     );
 
+    let current_block_number = ecx.env.block.number;
+
+    let blockhashes = (0..=255)
+        .map(|i| current_block_number - alloy_primitives::U256::from(i))
+        .map(|index| {
+            let block_hash = ecx.block_hash(index);
+            block_hash.map(|block_hash| (index, block_hash))
+        })
+        .take_while(|result| match result {
+            Ok((_, block_hash)) => !block_hash.is_zero(),
+            Err(_) => false,
+        })
+        .filter_map(Result::ok)
+        .collect();
+
     let call_ctx = CallContext {
         tx_caller: env.tx.caller,
         msg_sender: env.tx.caller,
         contract: transact_to.to_address(),
         delegate_as: None,
         block_number: env.block.number,
         block_timestamp: env.block.timestamp,
+        blockhashes,
         block_basefee: min(max_fee_per_gas.to_ru256(), env.block.basefee),
         is_create,
         is_static: false,
@@ -151,6 +167,21 @@ where
         PaymasterParams::default(),
     );
 
+    let current_block_number = ecx.env.block.number;
+
+    let blockhashes = (0..=255)
+        .map(|i| current_block_number - alloy_primitives::U256::from(i))
+        .map(|index| {
+            let block_hash = ecx.block_hash(index);
+            block_hash.map(|block_hash| (index, block_hash))
+        })
+        .take_while(|result| match result {
+            Ok((_, block_hash)) => !block_hash.is_zero(),
+            Err(_) => false,
+        })
+        .filter_map(Result::ok)
+        .collect();
+
     let call_ctx = CallContext {
         tx_caller: ecx.env.tx.caller,
         msg_sender: call.caller,
@@ -159,6 +190,7 @@ where
         block_number: ecx.env.block.number,
         block_timestamp: ecx.env.block.timestamp,
         block_basefee: min(max_fee_per_gas.to_ru256(), ecx.env.block.basefee),
+        blockhashes,
         is_create: true,
         is_static: false,
     };
@@ -201,6 +233,21 @@ where
         PaymasterParams::default(),
     );
 
+    let current_block_number = ecx.env.block.number;
+
+    let blockhashes = (0..=255)
+        .map(|i| current_block_number - alloy_primitives::U256::from(i))
+        .map(|index| {
+            let block_hash = ecx.block_hash(index);
+            block_hash.map(|block_hash| (index, block_hash))
+        })
+        .take_while(|result| match result {
+            Ok((_, block_hash)) => !block_hash.is_zero(),
+            Err(_) => false,
+        })
+        .filter_map(Result::ok)
+        .collect();
+
     // address and caller are specific to the type of call:
     // Call | StaticCall => { address: to, caller: contract.address }
     // CallCode          => { address: contract.address, caller: contract.address }
@@ -215,6 +262,7 @@ where
         },
         block_number: ecx.env.block.number,
         block_timestamp: ecx.env.block.timestamp,
+        blockhashes,
         block_basefee: min(max_fee_per_gas.to_ru256(), ecx.env.block.basefee),
         is_create: false,
         is_static: call.is_static,

diff --git a/crates/zksync/core/src/vm/tracer.rs b/crates/zksync/core/src/vm/tracer.rs
@@ -109,6 +109,8 @@ pub struct CallContext {
     pub is_create: bool,
     /// Whether the current call is a static call.
     pub is_static: bool,
+    /// Blockhashes
+    pub blockhashes: HashMap<alloy_primitives::U256, alloy_primitives::FixedBytes<32>>,
 }
 
 /// A tracer to allow for foundry-specific functionality.
@@ -295,17 +297,20 @@ impl<S: Send, H: HistoryMode> DynTracer<S, SimpleMemory<H>> for CheatcodeTracer
         }
 
         // Override blockhash
-        // if let Opcode::FarCall(_call) = data.opcode.variant.opcode {
-        //     let calldata = get_calldata(&state, memory);
-        //     let current = state.vm_local_state.callstack.current;
-
-        //     if current.code_address == SYSTEM_CONTEXT_ADDRESS &&
-        //         calldata.starts_with(&SELECTOR_BLOCK_HASH)
-        //     {
-        //         self.farcall_handler.set_immediate_return(rU256::ZERO.to_be_bytes_vec());
-        //         return
-        //     }
-        // }
+        if let Opcode::FarCall(_call) = data.opcode.variant.opcode {
+            let calldata = get_calldata(&state, memory);
+            let current = state.vm_local_state.callstack.current;
+
+            if current.code_address == SYSTEM_CONTEXT_ADDRESS &&
+                calldata.starts_with(&SELECTOR_BLOCK_HASH)
+            {
+                let index = U256::from_big_endian(&calldata[calldata.len() - 4..]);
+                if let Some(blockhash) = self.call_context.blockhashes.get(&index.to_ru256()) {
+                    self.farcall_handler.set_immediate_return(blockhash.to_vec());
+                    return;
+                }
+            }
+        }
 
         if let Some(delegate_as) = self.call_context.delegate_as {
             if let Opcode::FarCall(_call) = data.opcode.variant.opcode {