Merge pull request #3174 from poanetwork/vb-eip1967-transparent-proxy-support

EIP-1967 support: transparent proxy pattern

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Current
 
 ### Features
+- [#3174](https://github.com/poanetwork/blockscout/pull/3174) - EIP-1967 support: transparent proxy pattern
 - [#3173](https://github.com/poanetwork/blockscout/pull/3173) - Display implementation address at read/write proxy tabs
 - [#3171](https://github.com/poanetwork/blockscout/pull/3171) - Import accounts/contracts/balances from Geth genesis.json
 - [#3161](https://github.com/poanetwork/blockscout/pull/3161) - Write proxy contracts feature

apps/block_scout_web/lib/block_scout_web/controllers/smart_contract_controller.ex

@@ -14,16 +14,24 @@ defmodule BlockScoutWeb.SmartContractController do
     with true <- ajax?(conn),
          {:ok, address_hash} <- Chain.string_to_address_hash(address_hash_string),
          {:ok, address} <- Chain.find_contract_address(address_hash, address_options, true) do
+      implementation_address_hash_string =
+        if contract_type == "proxy" do
+          Chain.get_implementation_address_hash(address.hash, address.smart_contract.abi) ||
+            "0x0000000000000000000000000000000000000000"
+        else
+          "0x0000000000000000000000000000000000000000"
+        end
+
       functions =
         if action == "write" do
           if contract_type == "proxy" do
-            Writer.write_functions_proxy(address_hash)
+            Writer.write_functions_proxy(implementation_address_hash_string)
           else
             Writer.write_functions(address_hash)
           end
         else
           if contract_type == "proxy" do
-            Reader.read_only_functions_proxy(address_hash)
+            Reader.read_only_functions_proxy(address_hash, implementation_address_hash_string)
           else
             Reader.read_only_functions(address_hash)
           end
@@ -33,17 +41,13 @@ defmodule BlockScoutWeb.SmartContractController do
 
       implementation_abi =
         if contract_type == "proxy" do
-          address.hash
-          |> Chain.get_implementation_abi_from_proxy(address.smart_contract.abi)
+          implementation_address_hash_string
+          |> Chain.get_implementation_abi()
           |> Poison.encode!()
         else
           []
         end
 
-      implementation_address_hash_string =
-        Chain.get_implementation_address_hash(address.hash, address.smart_contract.abi) ||
-          "0x0000000000000000000000000000000000000000"
-
       conn
       |> put_status(200)
       |> put_layout(false)

apps/block_scout_web/test/block_scout_web/controllers/smart_contract_controller_test.exs

@@ -68,7 +68,56 @@ defmodule BlockScoutWeb.SmartContractControllerTest do
     test "lists [] proxy read only functions if no verified implementation" do
       token_contract_address = insert(:contract_address)
 
-      insert(:smart_contract, address_hash: token_contract_address.hash)
+      insert(:smart_contract,
+        address_hash: token_contract_address.hash,
+        abi: [
+          %{
+            "type" => "function",
+            "stateMutability" => "view",
+            "payable" => false,
+            "outputs" => [%{"type" => "address", "name" => ""}],
+            "name" => "implementation",
+            "inputs" => [],
+            "constant" => true
+          }
+        ]
+      )
+
+      path =
+        smart_contract_path(BlockScoutWeb.Endpoint, :index,
+          hash: token_contract_address.hash,
+          type: :proxy,
+          action: :read
+        )
+
+      conn =
+        build_conn()
+        |> put_req_header("x-requested-with", "xmlhttprequest")
+        |> get(path)
+
+      assert conn.status == 200
+      assert conn.assigns.read_only_functions == []
+    end
+
+    test "lists [] proxy read only functions if no verified eip-1967 implementation" do
+      token_contract_address = insert(:contract_address)
+
+      insert(:smart_contract,
+        address_hash: token_contract_address.hash,
+        abi: [
+          %{
+            "type" => "function",
+            "stateMutability" => "nonpayable",
+            "payable" => false,
+            "outputs" => [%{"type" => "address", "name" => "", "internalType" => "address"}],
+            "name" => "implementation",
+            "inputs" => [],
+            "constant" => false
+          }
+        ]
+      )
+
+      blockchain_get_implementation_mock()
 
       path =
         smart_contract_path(BlockScoutWeb.Endpoint, :index,
@@ -182,4 +231,14 @@ defmodule BlockScoutWeb.SmartContractControllerTest do
       end
     )
   end
+
+  defp blockchain_get_implementation_mock do
+    expect(
+      EthereumJSONRPC.Mox,
+      :json_rpc,
+      fn %{id: _, method: _, params: [_, _, _]}, _options ->
+        {:ok, "0xcebb2CCCFe291F0c442841cBE9C1D06EED61Ca02"}
+      end
+    )
+  end
 end

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/contract.ex

@@ -41,7 +41,7 @@ defmodule EthereumJSONRPC.Contract do
       |> Enum.map(fn {%{contract_address: contract_address, function_name: function_name, args: args} = request, index} ->
         functions[function_name]
         |> Encoder.encode_function_call(args)
-        |> eth_call_request(contract_address, index, Map.get(request, :block_number))
+        |> eth_call_request(contract_address, index, Map.get(request, :block_number), Map.get(request, :from))
       end)
       |> json_rpc(json_rpc_named_arguments)
       |> case do
@@ -70,7 +70,7 @@ defmodule EthereumJSONRPC.Contract do
       Enum.map(requests, fn _ -> format_error(error) end)
   end
 
-  defp eth_call_request(data, contract_address, id, block_number) do
+  defp eth_call_request(data, contract_address, id, block_number, from) do
     block =
       case block_number do
         nil -> "latest"
@@ -80,10 +80,28 @@ defmodule EthereumJSONRPC.Contract do
     request(%{
       id: id,
       method: "eth_call",
-      params: [%{to: contract_address, data: data}, block]
+      params: [%{to: contract_address, data: data, from: from}, block]
     })
   end
 
+  def eth_get_storage_at_request(contract_address, storage_pointer, block_number, json_rpc_named_arguments) do
+    block =
+      case block_number do
+        nil -> "latest"
+        block_number -> integer_to_quantity(block_number)
+      end
+
+    result =
+      %{id: 0, method: "eth_getStorageAt", params: [contract_address, storage_pointer, block]}
+      |> request()
+      |> json_rpc(json_rpc_named_arguments)
+
+    case result do
+      {:ok, storage_value} -> {:ok, storage_value}
+      other -> other
+    end
+  end
+
   defp format_error(message) when is_binary(message) do
     {:error, message}
   end

apps/explorer/lib/explorer/chain.ex

@@ -28,6 +28,7 @@ defmodule Explorer.Chain do
   alias Ecto.Adapters.SQL
   alias Ecto.{Changeset, Multi}
 
+  alias EthereumJSONRPC.Contract
   alias EthereumJSONRPC.Transaction, as: EthereumJSONRPCTransaction
 
   alias Explorer.Counters.LastFetchedCounter
@@ -4364,18 +4365,44 @@ defmodule Explorer.Chain do
 
   def get_implementation_address_hash(proxy_address_hash, abi)
       when not is_nil(proxy_address_hash) and not is_nil(abi) do
-    implementation_address =
-      case Reader.query_contract(proxy_address_hash, abi, %{
-             "implementation" => []
-           }) do
-        %{"implementation" => {:ok, [result]}} -> result
-        _ -> nil
-      end
+    implementation_method_abi =
+      abi
+      |> Enum.find(fn method ->
+        Map.get(method, "name") == "implementation"
+      end)
+
+    implementation_method_abi_state_mutability = Map.get(implementation_method_abi, "stateMutability")
+    is_eip1967 = if implementation_method_abi_state_mutability == "nonpayable", do: true, else: false
+
+    if is_eip1967 do
+      json_rpc_named_arguments = Application.get_env(:explorer, :json_rpc_named_arguments)
 
-    if implementation_address do
-      "0x" <> Base.encode16(implementation_address, case: :lower)
+      # https://eips.ethereum.org/EIPS/eip-1967
+      eip_1967_implementation_storage_pointer = "0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc"
+
+      {:ok, implementation_address} =
+        Contract.eth_get_storage_at_request(
+          proxy_address_hash,
+          eip_1967_implementation_storage_pointer,
+          nil,
+          json_rpc_named_arguments
+        )
+
+      implementation_address
     else
-      nil
+      implementation_address =
+        case Reader.query_contract(proxy_address_hash, abi, %{
+               "implementation" => []
+             }) do
+          %{"implementation" => {:ok, [result]}} -> result
+          _ -> nil
+        end
+
+      if implementation_address do
+        "0x" <> Base.encode16(implementation_address, case: :lower)
+      else
+        nil
+      end
     end
   end
 
@@ -4383,7 +4410,7 @@ defmodule Explorer.Chain do
     nil
   end
 
-  defp get_implementation_abi(implementation_address_hash_string) when not is_nil(implementation_address_hash_string) do
+  def get_implementation_abi(implementation_address_hash_string) when not is_nil(implementation_address_hash_string) do
     case Chain.string_to_address_hash(implementation_address_hash_string) do
       {:ok, implementation_address_hash} ->
         implementation_smart_contract =
@@ -4402,7 +4429,7 @@ defmodule Explorer.Chain do
     end
   end
 
-  defp get_implementation_abi(implementation_address_hash_string) when is_nil(implementation_address_hash_string) do
+  def get_implementation_abi(implementation_address_hash_string) when is_nil(implementation_address_hash_string) do
     []
   end
 

apps/explorer/lib/explorer/smart_contract/reader.ex

@@ -112,6 +112,32 @@ defmodule Explorer.SmartContract.Reader do
     end)
   end
 
+  @spec query_contract(
+          String.t(),
+          String.t(),
+          term(),
+          functions()
+        ) :: functions_results()
+  def query_contract(contract_address, from, abi, functions) do
+    requests =
+      functions
+      |> Enum.map(fn {function_name, args} ->
+        %{
+          contract_address: contract_address,
+          from: from,
+          function_name: function_name,
+          args: args
+        }
+      end)
+
+    requests
+    |> query_contracts(abi)
+    |> Enum.zip(requests)
+    |> Enum.into(%{}, fn {response, request} ->
+      {request.function_name, response}
+    end)
+  end
+
   @doc """
   Runs batch of contract functions on given addresses for smart contract with an expected ABI and functions.
 
@@ -180,13 +206,8 @@ defmodule Explorer.SmartContract.Reader do
     end
   end
 
-  def read_only_functions_proxy(contract_address_hash) do
-    abi =
-      contract_address_hash
-      |> Chain.address_hash_to_smart_contract()
-      |> Map.get(:abi)
-
-    implementation_abi = Chain.get_implementation_abi_from_proxy(contract_address_hash, abi)
+  def read_only_functions_proxy(contract_address_hash, implementation_address_hash_string) do
+    implementation_abi = Chain.get_implementation_abi(implementation_address_hash_string)
 
     case implementation_abi do
       nil ->

apps/explorer/lib/explorer/smart_contract/writer.ex

@@ -23,13 +23,8 @@ defmodule Explorer.SmartContract.Writer do
   end
 
   @spec write_functions_proxy(Hash.t()) :: [%{}]
-  def write_functions_proxy(contract_address_hash) do
-    abi =
-      contract_address_hash
-      |> Chain.address_hash_to_smart_contract()
-      |> Map.get(:abi)
-
-    implementation_abi = Chain.get_implementation_abi_from_proxy(contract_address_hash, abi)
+  def write_functions_proxy(implementation_address_hash_string) do
+    implementation_abi = Chain.get_implementation_abi(implementation_address_hash_string)
 
     case implementation_abi do
       nil ->

apps/explorer/test/explorer/chain_test.exs

@@ -5410,5 +5410,33 @@ defmodule Explorer.ChainTest do
 
       assert implementation_abi == @implementation_abi
     end
+
+    test "get_implementation_abi/1 returns empty [] abi if implmentation address is null" do
+      assert Chain.get_implementation_abi(nil) == []
+    end
+
+    test "get_implementation_abi/1 returns [] if implementation is not verified" do
+      implementation_contract_address = insert(:contract_address)
+
+      implementation_contract_address_hash_string =
+        Base.encode16(implementation_contract_address.hash.bytes, case: :lower)
+
+      assert Chain.get_implementation_abi("0x" <> implementation_contract_address_hash_string) == []
+    end
+
+    test "get_implementation_abi/1 returns implementation abi if implementation is verified" do
+      proxy_contract_address = insert(:contract_address)
+      insert(:smart_contract, address_hash: proxy_contract_address.hash, abi: @proxy_abi)
+
+      implementation_contract_address = insert(:contract_address)
+      insert(:smart_contract, address_hash: implementation_contract_address.hash, abi: @implementation_abi)
+
+      implementation_contract_address_hash_string =
+        Base.encode16(implementation_contract_address.hash.bytes, case: :lower)
+
+      implementation_abi = Chain.get_implementation_abi("0x" <> implementation_contract_address_hash_string)
+
+      assert implementation_abi == @implementation_abi
+    end
   end
 end

apps/explorer/test/explorer/smart_contract/reader_test.exs

@@ -220,24 +220,13 @@ defmodule Explorer.SmartContract.ReaderTest do
       implementation_contract_address_hash_string =
         Base.encode16(implementation_contract_address.hash.bytes, case: :lower)
 
-      expect(
-        EthereumJSONRPC.Mox,
-        :json_rpc,
-        fn [%{id: id, method: _, params: [%{data: _, to: _}, _]}], _options ->
-          {:ok,
-           [
-             %{
-               id: id,
-               jsonrpc: "2.0",
-               result: "0x000000000000000000000000" <> implementation_contract_address_hash_string
-             }
-           ]}
-        end
-      )
-
       blockchain_get_function_mock()
 
-      response = Reader.read_only_functions_proxy(proxy_smart_contract.address_hash)
+      response =
+        Reader.read_only_functions_proxy(
+          proxy_smart_contract.address_hash,
+          "0x" <> implementation_contract_address_hash_string
+        )
 
       assert [
                %{

apps/explorer/test/explorer/smart_contract/writer_test.exs

@@ -296,22 +296,7 @@ defmodule Explorer.SmartContract.WriterTest do
       implementation_contract_address_hash_string =
         Base.encode16(implementation_contract_address.hash.bytes, case: :lower)
 
-      expect(
-        EthereumJSONRPC.Mox,
-        :json_rpc,
-        fn [%{id: id, method: _, params: [%{data: _, to: _}, _]}], _options ->
-          {:ok,
-           [
-             %{
-               id: id,
-               jsonrpc: "2.0",
-               result: "0x000000000000000000000000" <> implementation_contract_address_hash_string
-             }
-           ]}
-        end
-      )
-
-      response = Writer.write_functions_proxy(proxy_smart_contract.address_hash)
+      response = Writer.write_functions_proxy("0x" <> implementation_contract_address_hash_string)
 
       assert [
                %{