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eth, internal: extend the TraceCall API (ethereum#22245)
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Adds an an optional parameter `overrides *map[common.Address]account` to the `eth_call` API in order for the caller to  can customize the state.
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@rjl493456442
rjl493456442 authored Apr 21, 2021
1 parent cc33398 commit dd9c322
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Showing 3 changed files with 226 additions and 21 deletions.
33 changes: 30 additions & 3 deletions eth/tracers/api.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,16 @@ type TraceConfig struct {
Reexec *uint64
}

// TraceCallConfig is the config for traceCall API. It holds one more
// field to override the state for tracing.
type TraceCallConfig struct {
*vm.LogConfig
Tracer *string
Timeout *string
Reexec *uint64
StateOverrides *ethapi.StateOverride
}

// StdTraceConfig holds extra parameters to standard-json trace functions.
type StdTraceConfig struct {
vm.LogConfig
Expand Down Expand Up @@ -720,7 +730,7 @@ func (api *API) TraceTransaction(ctx context.Context, hash common.Hash, config *
// created during the execution of EVM if the given transaction was added on
// top of the provided block and returns them as a JSON object.
// You can provide -2 as a block number to trace on top of the pending block.
func (api *API) TraceCall(ctx context.Context, args ethapi.CallArgs, blockNrOrHash rpc.BlockNumberOrHash, config *TraceConfig) (interface{}, error) {
func (api *API) TraceCall(ctx context.Context, args ethapi.CallArgs, blockNrOrHash rpc.BlockNumberOrHash, config *TraceCallConfig) (interface{}, error) {
// Try to retrieve the specified block
var (
err error
Expand All @@ -730,6 +740,8 @@ func (api *API) TraceCall(ctx context.Context, args ethapi.CallArgs, blockNrOrHa
block, err = api.blockByHash(ctx, hash)
} else if number, ok := blockNrOrHash.Number(); ok {
block, err = api.blockByNumber(ctx, number)
} else {
return nil, errors.New("invalid arguments; neither block nor hash specified")
}
if err != nil {
return nil, err
Expand All @@ -743,11 +755,26 @@ func (api *API) TraceCall(ctx context.Context, args ethapi.CallArgs, blockNrOrHa
if err != nil {
return nil, err
}
// Apply the customized state rules if required.
if config != nil {
if err := config.StateOverrides.Apply(statedb); err != nil {
return nil, err
}
}
// Execute the trace
msg := args.ToMessage(api.backend.RPCGasCap())
vmctx := core.NewEVMBlockContext(block.Header(), api.chainContext(ctx), nil)

return api.traceTx(ctx, msg, new(txTraceContext), vmctx, statedb, config)
var traceConfig *TraceConfig
if config != nil {
traceConfig = &TraceConfig{
LogConfig: config.LogConfig,
Tracer: config.Tracer,
Timeout: config.Timeout,
Reexec: config.Reexec,
}
}
return api.traceTx(ctx, msg, new(txTraceContext), vmctx, statedb, traceConfig)
}

// traceTx configures a new tracer according to the provided configuration, and
Expand Down Expand Up @@ -797,7 +824,7 @@ func (api *API) traceTx(ctx context.Context, message core.Message, txctx *txTrac

result, err := core.ApplyMessage(vmenv, message, new(core.GasPool).AddGas(message.Gas()))
if err != nil {
return nil, fmt.Errorf("tracing failed: %v", err)
return nil, fmt.Errorf("tracing failed: %w", err)
}

// Depending on the tracer type, format and return the output.
Expand Down
170 changes: 169 additions & 1 deletion eth/tracers/api_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@ import (
"bytes"
"context"
"crypto/ecdsa"
"encoding/json"
"errors"
"fmt"
"math/big"
Expand Down Expand Up @@ -198,7 +199,7 @@ func TestTraceCall(t *testing.T) {
var testSuite = []struct {
blockNumber rpc.BlockNumber
call ethapi.CallArgs
config *TraceConfig
config *TraceCallConfig
expectErr error
expect interface{}
}{
Expand Down Expand Up @@ -305,6 +306,147 @@ func TestTraceCall(t *testing.T) {
}
}

func TestOverridenTraceCall(t *testing.T) {
t.Parallel()

// Initialize test accounts
accounts := newAccounts(3)
genesis := &core.Genesis{Alloc: core.GenesisAlloc{
accounts[0].addr: {Balance: big.NewInt(params.Ether)},
accounts[1].addr: {Balance: big.NewInt(params.Ether)},
accounts[2].addr: {Balance: big.NewInt(params.Ether)},
}}
genBlocks := 10
signer := types.HomesteadSigner{}
api := NewAPI(newTestBackend(t, genBlocks, genesis, func(i int, b *core.BlockGen) {
// Transfer from account[0] to account[1]
// value: 1000 wei
// fee: 0 wei
tx, _ := types.SignTx(types.NewTransaction(uint64(i), accounts[1].addr, big.NewInt(1000), params.TxGas, big.NewInt(0), nil), signer, accounts[0].key)
b.AddTx(tx)
}))
randomAccounts, tracer := newAccounts(3), "callTracer"

var testSuite = []struct {
blockNumber rpc.BlockNumber
call ethapi.CallArgs
config *TraceCallConfig
expectErr error
expect *callTrace
}{
// Succcessful call with state overriding
{
blockNumber: rpc.PendingBlockNumber,
call: ethapi.CallArgs{
From: &randomAccounts[0].addr,
To: &randomAccounts[1].addr,
Value: (*hexutil.Big)(big.NewInt(1000)),
},
config: &TraceCallConfig{
Tracer: &tracer,
StateOverrides: &ethapi.StateOverride{
randomAccounts[0].addr: ethapi.OverrideAccount{Balance: newRPCBalance(new(big.Int).Mul(big.NewInt(1), big.NewInt(params.Ether)))},
},
},
expectErr: nil,
expect: &callTrace{
Type: "CALL",
From: randomAccounts[0].addr,
To: randomAccounts[1].addr,
Gas: newRPCUint64(24979000),
GasUsed: newRPCUint64(0),
Value: (*hexutil.Big)(big.NewInt(1000)),
},
},
// Invalid call without state overriding
{
blockNumber: rpc.PendingBlockNumber,
call: ethapi.CallArgs{
From: &randomAccounts[0].addr,
To: &randomAccounts[1].addr,
Value: (*hexutil.Big)(big.NewInt(1000)),
},
config: &TraceCallConfig{
Tracer: &tracer,
},
expectErr: core.ErrInsufficientFundsForTransfer,
expect: nil,
},
// Sucessful simple contract call
//
// // SPDX-License-Identifier: GPL-3.0
//
// pragma solidity >=0.7.0 <0.8.0;
//
// /**
// * @title Storage
// * @dev Store & retrieve value in a variable
// */
// contract Storage {
// uint256 public number;
// constructor() {
// number = block.number;
// }
// }
{
blockNumber: rpc.PendingBlockNumber,
call: ethapi.CallArgs{
From: &randomAccounts[0].addr,
To: &randomAccounts[2].addr,
Data: newRPCBytes(common.Hex2Bytes("8381f58a")), // call number()
},
config: &TraceCallConfig{
Tracer: &tracer,
StateOverrides: &ethapi.StateOverride{
randomAccounts[2].addr: ethapi.OverrideAccount{
Code: newRPCBytes(common.Hex2Bytes("6080604052348015600f57600080fd5b506004361060285760003560e01c80638381f58a14602d575b600080fd5b60336049565b6040518082815260200191505060405180910390f35b6000548156fea2646970667358221220eab35ffa6ab2adfe380772a48b8ba78e82a1b820a18fcb6f59aa4efb20a5f60064736f6c63430007040033")),
StateDiff: newStates([]common.Hash{{}}, []common.Hash{common.BigToHash(big.NewInt(123))}),
},
},
},
expectErr: nil,
expect: &callTrace{
Type: "CALL",
From: randomAccounts[0].addr,
To: randomAccounts[2].addr,
Input: hexutil.Bytes(common.Hex2Bytes("8381f58a")),
Output: hexutil.Bytes(common.BigToHash(big.NewInt(123)).Bytes()),
Gas: newRPCUint64(24978936),
GasUsed: newRPCUint64(2283),
Value: (*hexutil.Big)(big.NewInt(0)),
},
},
}
for _, testspec := range testSuite {
result, err := api.TraceCall(context.Background(), testspec.call, rpc.BlockNumberOrHash{BlockNumber: &testspec.blockNumber}, testspec.config)
if testspec.expectErr != nil {
if err == nil {
t.Errorf("Expect error %v, get nothing", testspec.expectErr)
continue
}
if !errors.Is(err, testspec.expectErr) {
t.Errorf("Error mismatch, want %v, get %v", testspec.expectErr, err)
}
} else {
if err != nil {
t.Errorf("Expect no error, get %v", err)
continue
}
ret := new(callTrace)
if err := json.Unmarshal(result.(json.RawMessage), ret); err != nil {
t.Fatalf("failed to unmarshal trace result: %v", err)
}
if !jsonEqual(ret, testspec.expect) {
// uncomment this for easier debugging
//have, _ := json.MarshalIndent(ret, "", " ")
//want, _ := json.MarshalIndent(testspec.expect, "", " ")
//t.Fatalf("trace mismatch: \nhave %+v\nwant %+v", string(have), string(want))
t.Fatalf("trace mismatch: \nhave %+v\nwant %+v", ret, testspec.expect)
}
}
}
}

func TestTraceTransaction(t *testing.T) {
t.Parallel()

Expand Down Expand Up @@ -469,3 +611,29 @@ func newAccounts(n int) (accounts Accounts) {
sort.Sort(accounts)
return accounts
}

func newRPCBalance(balance *big.Int) **hexutil.Big {
rpcBalance := (*hexutil.Big)(balance)
return &rpcBalance
}

func newRPCUint64(number uint64) *hexutil.Uint64 {
rpcUint64 := hexutil.Uint64(number)
return &rpcUint64
}

func newRPCBytes(bytes []byte) *hexutil.Bytes {
rpcBytes := hexutil.Bytes(bytes)
return &rpcBytes
}

func newStates(keys []common.Hash, vals []common.Hash) *map[common.Hash]common.Hash {
if len(keys) != len(vals) {
panic("invalid input")
}
m := make(map[common.Hash]common.Hash)
for i := 0; i < len(keys); i++ {
m[keys[i]] = vals[i]
}
return &m
}
44 changes: 27 additions & 17 deletions internal/ethapi/api.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@ import (
"github.com/ethereum/go-ethereum/consensus/clique"
"github.com/ethereum/go-ethereum/consensus/ethash"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/crypto"
Expand Down Expand Up @@ -802,29 +803,29 @@ func (args *CallArgs) ToMessage(globalGasCap uint64) types.Message {
return msg
}

// account indicates the overriding fields of account during the execution of
// a message call.
// OverrideAccount indicates the overriding fields of account during the execution
// of a message call.
// Note, state and stateDiff can't be specified at the same time. If state is
// set, message execution will only use the data in the given state. Otherwise
// if statDiff is set, all diff will be applied first and then execute the call
// message.
type account struct {
type OverrideAccount struct {
Nonce *hexutil.Uint64 `json:"nonce"`
Code *hexutil.Bytes `json:"code"`
Balance **hexutil.Big `json:"balance"`
State *map[common.Hash]common.Hash `json:"state"`
StateDiff *map[common.Hash]common.Hash `json:"stateDiff"`
}

func DoCall(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides map[common.Address]account, vmCfg vm.Config, timeout time.Duration, globalGasCap uint64) (*core.ExecutionResult, error) {
defer func(start time.Time) { log.Debug("Executing EVM call finished", "runtime", time.Since(start)) }(time.Now())
// StateOverride is the collection of overriden accounts.
type StateOverride map[common.Address]OverrideAccount

state, header, err := b.StateAndHeaderByNumberOrHash(ctx, blockNrOrHash)
if state == nil || err != nil {
return nil, err
// Apply overrides the fields of specified accounts into the given state.
func (diff *StateOverride) Apply(state *state.StateDB) error {
if diff == nil {
return nil
}
// Override the fields of specified contracts before execution.
for addr, account := range overrides {
for addr, account := range *diff {
// Override account nonce.
if account.Nonce != nil {
state.SetNonce(addr, uint64(*account.Nonce))
Expand All @@ -838,7 +839,7 @@ func DoCall(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.Blo
state.SetBalance(addr, (*big.Int)(*account.Balance))
}
if account.State != nil && account.StateDiff != nil {
return nil, fmt.Errorf("account %s has both 'state' and 'stateDiff'", addr.Hex())
return fmt.Errorf("account %s has both 'state' and 'stateDiff'", addr.Hex())
}
// Replace entire state if caller requires.
if account.State != nil {
Expand All @@ -851,6 +852,19 @@ func DoCall(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.Blo
}
}
}
return nil
}

func DoCall(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *StateOverride, vmCfg vm.Config, timeout time.Duration, globalGasCap uint64) (*core.ExecutionResult, error) {
defer func(start time.Time) { log.Debug("Executing EVM call finished", "runtime", time.Since(start)) }(time.Now())

state, header, err := b.StateAndHeaderByNumberOrHash(ctx, blockNrOrHash)
if state == nil || err != nil {
return nil, err
}
if err := overrides.Apply(state); err != nil {
return nil, err
}
// Setup context so it may be cancelled the call has completed
// or, in case of unmetered gas, setup a context with a timeout.
var cancel context.CancelFunc
Expand Down Expand Up @@ -929,12 +943,8 @@ func (e *revertError) ErrorData() interface{} {
//
// Note, this function doesn't make and changes in the state/blockchain and is
// useful to execute and retrieve values.
func (s *PublicBlockChainAPI) Call(ctx context.Context, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *map[common.Address]account) (hexutil.Bytes, error) {
var accounts map[common.Address]account
if overrides != nil {
accounts = *overrides
}
result, err := DoCall(ctx, s.b, args, blockNrOrHash, accounts, vm.Config{}, 5*time.Second, s.b.RPCGasCap())
func (s *PublicBlockChainAPI) Call(ctx context.Context, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *StateOverride) (hexutil.Bytes, error) {
result, err := DoCall(ctx, s.b, args, blockNrOrHash, overrides, vm.Config{}, 5*time.Second, s.b.RPCGasCap())
if err != nil {
return nil, err
}
Expand Down

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