Update tracer validation to account for storage struct (#81)

Author: hazim-j

internal/config/values.go

@@ -39,8 +39,8 @@ func envArrayToAddressSlice(s string) []common.Address {
 	return slc
 }
 
-// GetValues returns config for the bundler that has been read in from env vars.
-// See https://docs.stackup.sh/docs/packages/bundler/configure for details.
+// GetValues returns config for the bundler that has been read in from env vars. See
+// https://docs.stackup.sh/docs/packages/bundler/configure for details.
 func GetValues() *Values {
 	// Default variables
 	viper.SetDefault("erc4337_bundler_port", 4337)

pkg/entrypoint/callstack.go

@@ -0,0 +1,46 @@
+package entrypoint
+
+import (
+	"math/big"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/stackup-wallet/stackup-bundler/internal/utils"
+	"github.com/stackup-wallet/stackup-bundler/pkg/tracer"
+)
+
+type callEntry struct {
+	To     common.Address
+	Type   string
+	Method string
+	Revert any
+	Return any
+	Value  *big.Int
+}
+
+func newCallStack(calls []tracer.CallInfo) []*callEntry {
+	out := []*callEntry{}
+	stack := utils.NewStack[tracer.CallInfo]()
+	for _, call := range calls {
+		if call.Type == revertOpCode || call.Type == returnOpCode {
+			top, _ := stack.Pop()
+
+			if strings.Contains(top.Type, "CREATE") {
+				// TODO: implement...
+			} else if call.Type == revertOpCode {
+				// TODO: implement...
+			} else {
+				out = append(out, &callEntry{
+					To:     top.To,
+					Type:   top.Type,
+					Method: top.Method,
+					Return: call.Data,
+				})
+			}
+		} else {
+			stack.Push(call)
+		}
+	}
+
+	return out
+}

pkg/entrypoint/knownentity.go

@@ -0,0 +1,55 @@
+package entrypoint
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/stackup-wallet/stackup-bundler/pkg/tracer"
+	"github.com/stackup-wallet/stackup-bundler/pkg/userop"
+)
+
+type knownEntity map[string]struct {
+	Address  common.Address
+	Info     tracer.NumberLevelInfo
+	IsStaked bool
+}
+
+func newKnownEntity(
+	op *userop.UserOperation,
+	res *tracer.BundlerCollectorReturn,
+	stakes EntityStakes,
+) (knownEntity, error) {
+	if len(res.NumberLevels) != 3 {
+		return nil, fmt.Errorf("unexpected NumberLevels length in tracing result: %d", len(res.NumberLevels))
+	}
+
+	return knownEntity{
+		"factory": {
+			Address:  op.GetFactory(),
+			Info:     res.NumberLevels[factoryNumberLevel],
+			IsStaked: stakes[op.GetFactory()] != nil && stakes[op.GetFactory()].Staked,
+		},
+		"account": {
+			Address:  op.Sender,
+			Info:     res.NumberLevels[accountNumberLevel],
+			IsStaked: stakes[op.Sender] != nil && stakes[op.Sender].Staked,
+		},
+		"paymaster": {
+			Address:  op.GetPaymaster(),
+			Info:     res.NumberLevels[paymasterNumberLevel],
+			IsStaked: stakes[op.GetPaymaster()] != nil && stakes[op.GetPaymaster()].Staked,
+		},
+	}, nil
+}
+
+func addr2KnownEntity(op *userop.UserOperation, addr common.Address) string {
+	if addr == op.GetFactory() {
+		return "factory"
+	} else if addr == op.Sender {
+		return "account"
+	} else if addr == op.GetPaymaster() {
+		return "paymaster"
+	} else {
+		return addr.String()
+	}
+}

pkg/entrypoint/simulateutils.go

@@ -0,0 +1,61 @@
+package entrypoint
+
+import (
+	mapset "github.com/deckarep/golang-set/v2"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+// EntityStakes provides a mapping for encountered entity addresses and their stake info on the EntryPoint.
+type EntityStakes map[common.Address]*IStakeManagerDepositInfo
+
+type traceCallReq struct {
+	From common.Address `json:"from"`
+	To   common.Address `json:"to"`
+	Data hexutil.Bytes  `json:"data"`
+}
+
+type traceCallOpts struct {
+	Tracer string `json:"tracer"`
+}
+
+var (
+	// A dummy private key used to build *bind.TransactOpts for simulation.
+	dummyPk, _ = crypto.GenerateKey()
+
+	// Up to the first number marker represents factory validation.
+	factoryNumberLevel = 0
+
+	// After the first number marker and before the second represents account validation.
+	accountNumberLevel = 1
+
+	// After the second number marker represents paymaster validation.
+	paymasterNumberLevel = 2
+
+	// Only one create2 opcode is allowed if these two conditions are met:
+	// 	1. op.initcode.length != 0
+	// 	2. During account simulation (i.e. before markerOpCode)
+	create2OpCode = "CREATE2"
+
+	// List of opcodes not allowed during simulation for depth > 1 (i.e. account, paymaster, or contracts
+	// called by them).
+	bannedOpCodes = mapset.NewSet(
+		"GASPRICE",
+		"GASLIMIT",
+		"DIFFICULTY",
+		"TIMESTAMP",
+		"BASEFEE",
+		"BLOCKHASH",
+		"NUMBER",
+		"SELFBALANCE",
+		"BALANCE",
+		"ORIGIN",
+		"GAS",
+		"CREATE",
+		"COINBASE",
+	)
+
+	revertOpCode = "REVERT"
+	returnOpCode = "RETURN"
+)

pkg/entrypoint/simulatevalidation.go

@@ -0,0 +1,42 @@
+package entrypoint
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/stackup-wallet/stackup-bundler/pkg/userop"
+)
+
+// SimulateValidation makes a static call to Entrypoint.simulateValidation(userop) and returns the
+// results without any state changes.
+func SimulateValidation(
+	rpc *rpc.Client,
+	entryPoint common.Address,
+	op *userop.UserOperation,
+) (*ValidationResultRevert, error) {
+	ep, err := NewEntrypoint(entryPoint, ethclient.NewClient(rpc))
+	if err != nil {
+		return nil, err
+	}
+
+	var res []interface{}
+	rawCaller := &EntrypointRaw{Contract: ep}
+	err = rawCaller.Call(nil, &res, "simulateValidation", UserOperation(*op))
+	if err == nil {
+		return nil, errors.New("unexpected result from simulateValidation")
+	}
+
+	sim, simErr := newValidationResultRevert(err)
+	if simErr != nil {
+		fo, foErr := newFailedOpRevert(err)
+		if foErr != nil {
+			return nil, fmt.Errorf("%s, %s", simErr, foErr)
+		}
+		return nil, errors.New(fo.Reason)
+	}
+
+	return sim, nil
+}