Don't have the Deployer store the deployment block

Also updates how re-entrancy is handled to a more efficient and portable
mechanism.

processor/ethereum/deployer/contracts/Deployer.sol

@@ -34,41 +34,12 @@ pragma solidity ^0.8.26;
 */
 
 contract Deployer {
-  struct Deployment {
+  mapping(bytes32 => address) public deployments;
-    uint64 block_number;
-    address created_contract;
-  }
 
-  mapping(bytes32 => Deployment) public deployments;
-
-  error Reentrancy();
   error PriorDeployed();
   error DeploymentFailed();
 
   function deploy(bytes memory init_code) external {
-    // Prevent re-entrancy
-    // If we did allow it, one could deploy the same contract multiple times (with one overwriting
-    // the other's set value in storage)
-    bool called;
-    // This contract doesn't have any other use of transient storage, nor is to be inherited, making
-    // this usage of the zero address safe
-    assembly {
-      called := tload(0)
-    }
-    if (called) {
-      revert Reentrancy();
-    }
-    assembly {
-      tstore(0, 1)
-    }
-
-    // Check this wasn't prior deployed
-    bytes32 init_code_hash = keccak256(init_code);
-    Deployment memory deployment = deployments[init_code_hash];
-    if (deployment.created_contract == address(0)) {
-      revert PriorDeployed();
-    }
-
     // Deploy the contract
     address created_contract;
     assembly {
@@ -78,9 +49,15 @@ contract Deployer {
       revert DeploymentFailed();
     }
 
-    // Set the dpeloyment to storage
+    bytes32 init_code_hash = keccak256(init_code);
-    deployment.block_number = uint64(block.number);
+
-    deployment.created_contract = created_contract;
+    // Check this wasn't prior deployed
-    deployments[init_code_hash] = deployment;
+    // We check this *after* deploymeing (in violation of CEI) to handle re-entrancy related bugs
+    if (deployments[init_code_hash] != address(0)) {
+      revert PriorDeployed();
+    }
+
+    // Write the deployment to storage
+    deployments[init_code_hash] = created_contract;
   }
 }

processor/ethereum/deployer/src/lib.rs

@@ -30,7 +30,7 @@ mod abi {
 /// compatible chain. It then supports retrieving the Router contract's address (which isn't
 /// deterministic) using a single call.
 #[derive(Clone, Debug)]
-pub struct Deployer;
+pub struct Deployer(Arc<RootProvider<SimpleRequest>>);
 impl Deployer {
   /// Obtain the transaction to deploy this contract, already signed.
   ///
@@ -38,8 +38,8 @@ impl Deployer {
   /// funded for this transaction to be submitted. This account has no known private key to anyone
   /// so ETH sent can be neither misappropriated nor returned.
   pub fn deployment_tx() -> Signed<TxLegacy> {
-    pub const BYTECODE: &str =
+    pub const BYTECODE: &[u8] =
-      include_str!(concat!(env!("OUT_DIR"), "/serai-processor-ethereum-deployer/Deployer.bin"));
+      include_bytes!(concat!(env!("OUT_DIR"), "/serai-processor-ethereum-deployer/Deployer.bin"));
     let bytecode =
       Bytes::from_hex(BYTECODE).expect("compiled-in Deployer bytecode wasn't valid hex");
 
@@ -75,28 +75,27 @@ impl Deployer {
     if code.is_empty() {
       return Ok(None);
     }
-    Ok(Some(Self))
+    Ok(Some(Self(provider)))
   }
 
   /// Find the deployment of a contract.
   pub async fn find_deployment(
     &self,
-    provider: Arc<RootProvider<SimpleRequest>>,
     init_code_hash: [u8; 32],
-  ) -> Result<Option<abi::Deployer::Deployment>, RpcError<TransportErrorKind>> {
+  ) -> Result<Option<Address>, RpcError<TransportErrorKind>> {
     let call = TransactionRequest::default().to(Self::address()).input(TransactionInput::new(
       abi::Deployer::deploymentsCall::new((init_code_hash.into(),)).abi_encode().into(),
     ));
-    let bytes = provider.call(&call).await?;
+    let bytes = self.0.call(&call).await?;
     let deployment = abi::Deployer::deploymentsCall::abi_decode_returns(&bytes, true)
       .map_err(|e| {
         TransportErrorKind::Custom(
-          format!("node returned a non-Deployment for function returning Deployment: {e:?}").into(),
+          format!("node returned a non-address for function returning address: {e:?}").into(),
         )
       })?
       ._0;
 
-    if deployment.created_contract == [0; 20] {
+    if **deployment == [0; 20] {
       return Ok(None);
     }
     Ok(Some(deployment))