From 4ce676916fd08f8fbe19d3c80ac066de581375ca Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Cornilleau <pierre-emmanuel.cornilleau@lambda-coins.com>
Date: Mon, 9 Sep 2024 17:56:45 +0200
Subject: [PATCH 1/5] EVM/Node: eth call state diff encoding

---
 .../lib_dev/encodings/ethereum_types.ml       | 27 ++++++++++++++++---
 .../lib_dev/encodings/ethereum_types.mli      |  7 +++++
 etherlink/bin_node/lib_dev/state_override.ml  | 16 ++++++++++-
 3 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/etherlink/bin_node/lib_dev/encodings/ethereum_types.ml b/etherlink/bin_node/lib_dev/encodings/ethereum_types.ml
index e38b1ff9a5ac..9714495d7e01 100644
--- a/etherlink/bin_node/lib_dev/encodings/ethereum_types.ml
+++ b/etherlink/bin_node/lib_dev/encodings/ethereum_types.ml
@@ -1059,10 +1059,23 @@ module From_rlp = struct
         Result_syntax.return @@ Z.to_int @@ Z.of_bits @@ Bytes.to_string b)
 end
 
+module StorageKey = struct
+  type t = hex
+
+  let compare (Hex a) (Hex b) = String.compare a b
+
+  let of_string = hex_of_string
+
+  let to_string = hex_to_string
+end
+
+module StorageMap = MapMake (StorageKey)
+
 type state_account_override = {
   balance : quantity option;
   nonce : quantity option;
   code : hex option;
+  state_diff : hex StorageMap.t;
 }
 
 type state_override = state_account_override AddressMap.t
@@ -1070,12 +1083,18 @@ type state_override = state_account_override AddressMap.t
 let state_account_override_encoding =
   let open Data_encoding in
   conv
-    (fun {balance; nonce; code} -> (balance, nonce, code))
-    (fun (balance, nonce, code) -> {balance; nonce; code})
-    (obj3
+    (fun {balance; nonce; code; state_diff} ->
+      (balance, nonce, code, state_diff))
+    (fun (balance, nonce, code, state_diff) ->
+      {balance; nonce; code; state_diff})
+    (obj4
        (opt "balance" quantity_encoding)
        (opt "nonce" quantity_encoding)
-       (opt "code" hex_encoding))
+       (opt "code" hex_encoding)
+       (dft
+          "state_diff"
+          (StorageMap.associative_array_encoding hex_encoding)
+          StorageMap.empty))
 
 let state_override_empty = AddressMap.empty
 
diff --git a/etherlink/bin_node/lib_dev/encodings/ethereum_types.mli b/etherlink/bin_node/lib_dev/encodings/ethereum_types.mli
index e2eb6532cd97..db0d09f40f3a 100644
--- a/etherlink/bin_node/lib_dev/encodings/ethereum_types.mli
+++ b/etherlink/bin_node/lib_dev/encodings/ethereum_types.mli
@@ -232,10 +232,17 @@ type txpool = {
 
 val txpool_encoding : txpool Data_encoding.t
 
+module StorageMap : sig
+  include Map.S with type key = hex
+
+  val associative_array_encoding : 'a Data_encoding.t -> 'a t Data_encoding.t
+end
+
 type state_account_override = {
   balance : quantity option;
   nonce : quantity option;
   code : hex option;
+  state_diff : hex StorageMap.t;
 }
 
 type state_override = state_account_override AddressMap.t
diff --git a/etherlink/bin_node/lib_dev/state_override.ml b/etherlink/bin_node/lib_dev/state_override.ml
index 9d4a9bd7c73f..75e6070a217a 100644
--- a/etherlink/bin_node/lib_dev/state_override.ml
+++ b/etherlink/bin_node/lib_dev/state_override.ml
@@ -11,7 +11,20 @@ let durable_nonce v = v |> Ethereum_types.encode_u64_le |> Bytes.to_string
 
 let durable_code = Ethereum_types.hex_to_bytes
 
-let update_account address {Ethereum_types.balance; nonce; code} state =
+let update_storage address state_diff state =
+  let open Ethereum_types in
+  let update key value state =
+    let (Hex key) = key in
+    let (Hex value) = value in
+    Evm_state.modify
+      ~key:(Durable_storage_path.Accounts.storage address key)
+      ~value
+      state
+  in
+  StorageMap.fold_s update state_diff state
+
+let update_account address {Ethereum_types.balance; nonce; code; state_diff}
+    state =
   let open Durable_storage_path in
   let open Lwt_syntax in
   let update v_opt key encode state =
@@ -24,6 +37,7 @@ let update_account address {Ethereum_types.balance; nonce; code} state =
   in
   let* state = update nonce (Accounts.nonce address) durable_nonce state in
   let* state = update code (Accounts.code address) durable_code state in
+  let* state = update_storage address state_diff state in
   return state
 
 let update_accounts state_override state =
-- 
GitLab


From c93d6cea1077ae940fa6d6c8700fb746d34654b1 Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Cornilleau <pierre-emmanuel.cornilleau@lambda-coins.com>
Date: Mon, 9 Sep 2024 17:57:17 +0200
Subject: [PATCH 2/5] EVM/tezt: state diff override test

---
 .../state_override_tester.sol                 |  5 +-
 .../state_override_tester_readable.sol        | 12 ++-
 etherlink/tezt/tests/eth_call.ml              | 86 ++++++++++++++++++-
 3 files changed, 99 insertions(+), 4 deletions(-)

diff --git a/etherlink/kernel_evm/solidity_examples/state_override_tester.sol b/etherlink/kernel_evm/solidity_examples/state_override_tester.sol
index c31bc544624a..a91b3b8e612d 100644
--- a/etherlink/kernel_evm/solidity_examples/state_override_tester.sol
+++ b/etherlink/kernel_evm/solidity_examples/state_override_tester.sol
@@ -9,7 +9,10 @@ contract Child {
 
 contract StateOverrideTester {
 
-    int private count = 42;
+    uint32 private count = 42; // private, so requires an explicit accessor
+    uint32 public const2 = 0xffffffff;
+    uint256 public sep = 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff;
+    uint32 public const3 = 0xffffffff;
 
     function getBalance() public view returns (uint256) {
         return msg.sender.balance;
diff --git a/etherlink/kernel_evm/solidity_examples/state_override_tester_readable.sol b/etherlink/kernel_evm/solidity_examples/state_override_tester_readable.sol
index 1eebcb578686..527367d81dfc 100644
--- a/etherlink/kernel_evm/solidity_examples/state_override_tester_readable.sol
+++ b/etherlink/kernel_evm/solidity_examples/state_override_tester_readable.sol
@@ -2,13 +2,21 @@
 pragma solidity ^0.8.4;
 
 contract StateOverrideTester {
-    int private count = 42;
+    // first two 32bit value should be in same memory slot
+    uint32 private count = 42; // private, so require an explicit accessor
+    uint32 public const2 = 0xffffffff;
+
+    // define a 32byte value to open a new memory slot
+    uint256 public sep = 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff;
+
+    // should be a third slot
+    uint32 public const3 = 0xffffffff;
 
     function getBalance() public view returns (uint256) {
         return msg.sender.balance;
     }
 
-    function getCount() public view returns (int) {
+    function getCount() public view returns (uint32) {
         return count;
     }
 }
diff --git a/etherlink/tezt/tests/eth_call.ml b/etherlink/tezt/tests/eth_call.ml
index 0075b7a1b3cf..4b7d0e90d800 100644
--- a/etherlink/tezt/tests/eth_call.ml
+++ b/etherlink/tezt/tests/eth_call.ml
@@ -49,7 +49,7 @@ let test_call_state_override_balance =
   @@ fun {sequencer; _} _protocol ->
   (*
       This test checks that the simulation allows balance override.
-      To do so we deploy a contract which returns the balance of the message 
+      To do so we deploy a contract which returns the balance of the message
       sender, and call it with a non-sensical address.
   *)
   let* constant = Solidity_contracts.state_override_tester () in
@@ -238,9 +238,93 @@ let test_call_state_override_nonce =
 
   unit
 
+let test_call_state_override_state_diff =
+  register
+    ~kernels:[Latest] (* Not a kernel specific test. *)
+    ~tags:["evm"; "state_override"; "state_diff"; "eth_call"]
+    ~title:"Can override part of account storage in eth_call"
+  @@ fun {sequencer; _} _protocol ->
+  (*
+      This test checks that the simulation allows state diff override.
+      To do so we deploy a contract with a value in storage, and call it with an
+      alternative storage that changes that value.
+  *)
+  let* constant = Solidity_contracts.state_override_tester_readable () in
+  let* () = Eth_cli.add_abi ~label:constant.label ~abi:constant.abi () in
+  (* Deploy the contract. *)
+  let* contract, _tx_hash =
+    send_transaction_to_sequencer
+      (fun () ->
+        Eth_cli.deploy
+          ~source_private_key:Eth_account.bootstrap_accounts.(0).private_key
+          ~endpoint:(Evm_node.endpoint sequencer)
+          ~abi:constant.abi
+          ~bin:constant.bin)
+      sequencer
+  in
+
+  (* helpers *)
+  let call_method m =
+    let* calldata = Cast.calldata m in
+    return (`O [("to", `String contract); ("data", `String calldata)])
+  in
+  let make_call ?(override = []) m =
+    let* call = call_method m in
+    Evm_node.call_evm_rpc
+      sequencer
+      {method_ = "eth_call"; parameters = `A (call :: override)}
+  in
+  let check_value call_result expected =
+    Check.(
+      (Evm_node.extract_result call_result |> JSON.as_string = expected) string)
+      ~error_msg:"Expected result %R but got %L "
+  in
+
+  (* Check the starting contract storage *)
+  let* call_result = make_call "getCount()" in
+  check_value
+    call_result
+    "0x000000000000000000000000000000000000000000000000000000000000002a" ;
+  let* call_result = make_call "const2()" in
+  check_value
+    call_result
+    "0x00000000000000000000000000000000000000000000000000000000ffffffff" ;
+  let* call_result = make_call "const3()" in
+  check_value
+    call_result
+    "0x00000000000000000000000000000000000000000000000000000000ffffffff" ;
+
+  (* try again with an override *)
+  let state_diff =
+    `O
+      [
+        ( "0x0000000000000000000000000000000000000000000000000000000000000000",
+          `String
+            "0x0000000000000000000000000000000000000000000000000000000000000000"
+        );
+      ]
+  in
+  let override = [`O [(contract, `O [("state_diff", state_diff)])]] in
+  let* call_result = make_call ~override "getCount()" in
+  check_value
+    call_result
+    "0x0000000000000000000000000000000000000000000000000000000000000000" ;
+  (* const2 is stored in same memory slot so should change *)
+  let* call_result = make_call ~override "const2()" in
+  check_value
+    call_result
+    "0x0000000000000000000000000000000000000000000000000000000000000000" ;
+  (* const3 is stored in a distinct memory slot so should be unchanged *)
+  let* call_result = make_call ~override "const3()" in
+  check_value
+    call_result
+    "0x00000000000000000000000000000000000000000000000000000000ffffffff" ;
+  unit
+
 let protocols = Protocol.all
 
 let () =
   test_call_state_override_code protocols ;
   test_call_state_override_nonce protocols ;
+  test_call_state_override_state_diff protocols ;
   test_call_state_override_balance protocols
-- 
GitLab


From fedb83e96ffc7e3f91de5b7f3aa15ee7088d01dd Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Cornilleau <pierre-emmanuel.cornilleau@lambda-coins.com>
Date: Thu, 12 Sep 2024 14:27:51 +0200
Subject: [PATCH 3/5] EVM/Node: wrap State_override in tzresult

---
 etherlink/bin_node/lib_dev/evm_ro_context.ml  |  2 +-
 etherlink/bin_node/lib_dev/state_override.ml  | 26 ++++++++++++-------
 etherlink/bin_node/lib_dev/state_override.mli |  4 ++-
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/etherlink/bin_node/lib_dev/evm_ro_context.ml b/etherlink/bin_node/lib_dev/evm_ro_context.ml
index 166e5eaaf741..d438723263f5 100644
--- a/etherlink/bin_node/lib_dev/evm_ro_context.ml
+++ b/etherlink/bin_node/lib_dev/evm_ro_context.ml
@@ -205,7 +205,7 @@ struct
           ~destination:Ctxt.ctxt.smart_rollup_address
           ()
       in
-      let*! simulate_state =
+      let* simulate_state =
         State_override.update_accounts state_override simulate_state
       in
       let* raw_insights =
diff --git a/etherlink/bin_node/lib_dev/state_override.ml b/etherlink/bin_node/lib_dev/state_override.ml
index 75e6070a217a..41e278e20c19 100644
--- a/etherlink/bin_node/lib_dev/state_override.ml
+++ b/etherlink/bin_node/lib_dev/state_override.ml
@@ -13,24 +13,30 @@ let durable_code = Ethereum_types.hex_to_bytes
 
 let update_storage address state_diff state =
   let open Ethereum_types in
+  let open Lwt_result_syntax in
   let update key value state =
     let (Hex key) = key in
     let (Hex value) = value in
-    Evm_state.modify
-      ~key:(Durable_storage_path.Accounts.storage address key)
-      ~value
-      state
+    let*! state =
+      Evm_state.modify
+        ~key:(Durable_storage_path.Accounts.storage address key)
+        ~value
+        state
+    in
+    return state
   in
-  StorageMap.fold_s update state_diff state
+  StorageMap.fold_es update state_diff state
 
 let update_account address {Ethereum_types.balance; nonce; code; state_diff}
     state =
   let open Durable_storage_path in
-  let open Lwt_syntax in
+  let open Lwt_result_syntax in
   let update v_opt key encode state =
     match v_opt with
-    | None -> Lwt_syntax.return state
-    | Some v -> Evm_state.modify ~key ~value:(encode v) state
+    | None -> return state
+    | Some v ->
+        let*! state = Evm_state.modify ~key ~value:(encode v) state in
+        return state
   in
   let* state =
     update balance (Accounts.balance address) durable_balance state
@@ -42,5 +48,5 @@ let update_account address {Ethereum_types.balance; nonce; code; state_diff}
 
 let update_accounts state_override state =
   match state_override with
-  | None -> Lwt_syntax.return state
-  | Some so -> Ethereum_types.AddressMap.fold_s update_account so state
+  | None -> Lwt_result_syntax.return state
+  | Some so -> Ethereum_types.AddressMap.fold_es update_account so state
diff --git a/etherlink/bin_node/lib_dev/state_override.mli b/etherlink/bin_node/lib_dev/state_override.mli
index 470131e98571..2c54a5acbcce 100644
--- a/etherlink/bin_node/lib_dev/state_override.mli
+++ b/etherlink/bin_node/lib_dev/state_override.mli
@@ -6,4 +6,6 @@
 (*****************************************************************************)
 
 val update_accounts :
-  Ethereum_types.state_override option -> Evm_state.t -> Evm_state.t Lwt.t
+  Ethereum_types.state_override option ->
+  Evm_state.t ->
+  Evm_state.t tzresult Lwt.t
-- 
GitLab


From b78e9d0b78abb4afc269c97a73d4d660deaf7abb Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Cornilleau <pierre-emmanuel.cornilleau@lambda-coins.com>
Date: Thu, 12 Sep 2024 15:28:27 +0200
Subject: [PATCH 4/5] EVM/Node: input validation for state override

---
 .../bin_node/lib_dev/durable_storage_path.ml  | 65 ++++++++++++++++---
 .../bin_node/lib_dev/durable_storage_path.mli | 15 +++++
 etherlink/bin_node/lib_dev/state_override.ml  | 26 ++++++--
 3 files changed, 89 insertions(+), 17 deletions(-)

diff --git a/etherlink/bin_node/lib_dev/durable_storage_path.ml b/etherlink/bin_node/lib_dev/durable_storage_path.ml
index 17ff4106fab9..d9466b81cc99 100644
--- a/etherlink/bin_node/lib_dev/durable_storage_path.ml
+++ b/etherlink/bin_node/lib_dev/durable_storage_path.ml
@@ -51,29 +51,74 @@ let sequencer_key = EVM.make "/sequencer"
 let maximum_gas_per_transaction = EVM.make "/maximum_gas_per_transaction"
 
 module Accounts = struct
-  let accounts = World_state.make "/eth_accounts"
+  let accounts_path = World_state.make "/eth_accounts"
 
-  let balance = "/balance"
+  let balance_path = "/balance"
 
-  let nonce = "/nonce"
+  let nonce_path = "/nonce"
 
-  let code = "/code"
+  let code_path = "/code"
 
   let code_hash = "/code.hash"
 
-  let storage = "/storage"
+  let storage_path = "/storage"
 
-  let account (Address (Hex s)) = accounts ^ "/" ^ s
+  let account (Address (Hex s)) = accounts_path ^ "/" ^ s
 
-  let balance address = account address ^ balance
+  let balance address = account address ^ balance_path
 
-  let nonce address = account address ^ nonce
+  let nonce address = account address ^ nonce_path
 
-  let code address = account address ^ code
+  let code address = account address ^ code_path
 
   let code_hash address = account address ^ code_hash
 
-  let storage address index = account address ^ storage ^ "/" ^ index
+  let storage address index = account address ^ storage_path ^ "/" ^ index
+
+  type error += Invalid_address of string | Invalid_key of string
+
+  let () =
+    register_error_kind
+      `Permanent
+      ~id:"durable_storage_invalid_address"
+      ~title:"Invalid address"
+      ~description:"Tried to access the account storage of an invalid address."
+      ~pp:(fun ppf path ->
+        Format.fprintf ppf "No account storage for invalid address %s" path)
+      Data_encoding.(obj1 (req "durable_storage_invalid_address" string))
+      (function Invalid_address path -> Some path | _ -> None)
+      (fun path -> Invalid_address path) ;
+    register_error_kind
+      `Permanent
+      ~id:"durable_storage_invalid_key"
+      ~title:"Invalid storage key"
+      ~description:"Tried to access an invalid key in an account storage."
+      ~pp:(fun ppf path ->
+        Format.fprintf ppf "%s is not a valid storage key" path)
+      Data_encoding.(obj1 (req "durable_storage_invalid_key" string))
+      (function Invalid_key path -> Some path | _ -> None)
+      (fun path -> Invalid_key path)
+
+  let account_e (Address (Hex s)) =
+    let open Result_syntax in
+    if String.length s = 40 then return (accounts_path ^ "/" ^ s)
+    else tzfail (Invalid_address s)
+
+  let concat_e address path =
+    let open Result_syntax in
+    let* address_path = account_e address in
+    return (address_path ^ path)
+
+  let balance_e address = concat_e address balance_path
+
+  let nonce_e address = concat_e address nonce_path
+
+  let code_e address = concat_e address code_path
+
+  let storage_e address index =
+    if String.length index = 64 then
+      concat_e address (storage_path ^ "/" ^ index)
+    else Result_syntax.tzfail (Invalid_key index)
 end
 
 module Code = struct
diff --git a/etherlink/bin_node/lib_dev/durable_storage_path.mli b/etherlink/bin_node/lib_dev/durable_storage_path.mli
index a7d51da3da97..6cce82a852ed 100644
--- a/etherlink/bin_node/lib_dev/durable_storage_path.mli
+++ b/etherlink/bin_node/lib_dev/durable_storage_path.mli
@@ -54,6 +54,21 @@ module Accounts : sig
 
   (** Path to the account's storage at a given index. *)
   val storage : address -> path -> path
+
+  type error += Invalid_address of string | Invalid_key of string
+
+  (** Path to the account's balance. Error if address is invalid. *)
+  val balance_e : address -> path tzresult
+
+  (** Path to the account's nonce. Error if address is invalid. *)
+  val nonce_e : address -> path tzresult
+
+  (** Path to the account's code. Error if address is invalid. *)
+  val code_e : address -> path tzresult
+
+  (** Path to the account's storage at a given index. Error if address or
+      storage key is invalid. *)
+  val storage_e : address -> path -> path tzresult
 end
 
 module Code : sig
diff --git a/etherlink/bin_node/lib_dev/state_override.ml b/etherlink/bin_node/lib_dev/state_override.ml
index 41e278e20c19..e0b4baccb011 100644
--- a/etherlink/bin_node/lib_dev/state_override.ml
+++ b/etherlink/bin_node/lib_dev/state_override.ml
@@ -11,19 +11,31 @@ let durable_nonce v = v |> Ethereum_types.encode_u64_le |> Bytes.to_string
 
 let durable_code = Ethereum_types.hex_to_bytes
 
+type error += Invalid_storage_value of string
+
+let () =
+  register_error_kind
+    `Permanent
+    ~id:"durable_storage_invalid_value"
+    ~title:"Invalid storage value"
+    ~description:"Tried to set an invalid value in an account storage."
+    ~pp:(fun ppf path ->
+      Format.fprintf ppf "%s is not a valid storage value" path)
+    Data_encoding.(obj1 (req "durable_storage_invalid_value" string))
+    (function Invalid_storage_value path -> Some path | _ -> None)
+    (fun path -> Invalid_storage_value path)
+
 let update_storage address state_diff state =
   let open Ethereum_types in
   let open Lwt_result_syntax in
   let update key value state =
     let (Hex key) = key in
     let (Hex value) = value in
-    let*! state =
-      Evm_state.modify
-        ~key:(Durable_storage_path.Accounts.storage address key)
-        ~value
-        state
-    in
-    return state
+    if String.length value = 64 then
+      let*? key = Durable_storage_path.Accounts.storage_e address key in
+      let*! state = Evm_state.modify ~key ~value state in
+      return state
+    else tzfail (Invalid_storage_value value)
   in
   StorageMap.fold_es update state_diff state
 
-- 
GitLab


From ac817c5f6f3761ec015e019fca7e7b308508419c Mon Sep 17 00:00:00 2001
From: Pierre-Emmanuel Cornilleau <pierre-emmanuel.cornilleau@lambda-coins.com>
Date: Thu, 12 Sep 2024 16:46:45 +0200
Subject: [PATCH 5/5] EVM/tezt: small test for state_diff error

---
 etherlink/tezt/tests/eth_call.ml | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/etherlink/tezt/tests/eth_call.ml b/etherlink/tezt/tests/eth_call.ml
index 4b7d0e90d800..719c42bac497 100644
--- a/etherlink/tezt/tests/eth_call.ml
+++ b/etherlink/tezt/tests/eth_call.ml
@@ -319,6 +319,25 @@ let test_call_state_override_state_diff =
   check_value
     call_result
     "0x00000000000000000000000000000000000000000000000000000000ffffffff" ;
+
+  (* try with an invalid override *)
+  let invalid =
+    `O
+      [
+        ( "0x00",
+          `String
+            "0x0000000000000000000000000000000000000000000000000000000000000000"
+        );
+      ]
+  in
+  let override = [`O [(contract, `O [("state_diff", invalid)])]] in
+  let* call_result = make_call ~override "getCount()" in
+  Check.(
+    (Evm_node.extract_error_message call_result
+    |> JSON.as_string = "Error:\n  00 is not a valid storage key\n")
+      string)
+    ~error_msg:"Expected error %R but got %L " ;
+
   unit
 
 let protocols = Protocol.all
-- 
GitLab