/
evm.go
571 lines (515 loc) · 20.1 KB
/
evm.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
package vm
import (
"github.com/LemoFoundationLtd/lemochain-core/chain/params"
"github.com/LemoFoundationLtd/lemochain-core/chain/types"
"github.com/LemoFoundationLtd/lemochain-core/common"
"github.com/LemoFoundationLtd/lemochain-core/common/crypto"
"github.com/LemoFoundationLtd/lemochain-core/common/log"
"github.com/LemoFoundationLtd/lemochain-core/store"
"math/big"
"strconv"
"sync/atomic"
"time"
)
type (
CanTransferFunc func(AccountManager, common.Address, *big.Int) bool
TransferFunc func(AccountManager, common.Address, common.Address, *big.Int)
// GetHashFunc returns the nth block hash in the blockchain
// and is used by the BLOCKHASH EVM op code.
GetHashFunc func(uint32) common.Hash
)
// run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter.
func run(evm *EVM, contract *Contract, input []byte) ([]byte, error) {
if contract.CodeAddr != nil {
precompiles := PrecompiledContracts
if p := precompiles[*contract.CodeAddr]; p != nil {
// Determine whether the address to set the reward value is correct
if *contract.CodeAddr == params.TermRewardContract && contract.caller.GetAddress() != evm.vmConfig.RewardManager {
return nil, ErrTermReward
}
return RunPrecompiledContract(p, input, contract, evm)
}
}
return evm.interpreter.Run(contract, input)
}
// Context provides the EVM with auxiliary information. Once provided
// it shouldn't be modified.
type Context struct {
// CanTransfer returns whether the account contains
// sufficient lemo to transfer the value
CanTransfer CanTransferFunc
// Transfer transfers lemo from one account to the other
Transfer TransferFunc
// GetHash returns the hash corresponding to n
GetHash GetHashFunc
// Provides the current transaction hash which is used when EVM emits new contract events.
TxIndex uint
TxHash common.Hash
BlockHash common.Hash
// Message information
Origin common.Address // Provides information for ORIGIN
GasPrice *big.Int // Provides information for GASPRICE
// Block information
MinerAddress common.Address // Provides information for MinerAddress
GasLimit uint64 // Provides information for GASLIMIT
BlockHeight uint32 // Provides information for HEIGHT
Time uint32 // Provides information for TIME
}
// EVM is the Lemochain Virtual Machine base object and provides
// the necessary tools to run a contract on the given state with
// the provided context. It should be noted that any error
// generated through any of the calls should be considered a
// revert-state-and-consume-all-gas operation, no checks on
// specific errors should ever be performed. The interpreter makes
// sure that any errors generated are to be considered faulty code.
//
// The EVM should never be reused and is not thread safe.
type EVM struct {
// Context provides auxiliary blockchain related information
Context
// am gives access to the underlying state
am AccountManager
// Depth is the current call stack
depth int
// virtual machine configuration options used to initialise the
// evm.
vmConfig Config
// global (to this context) lemochain virtual machine
// used throughout the execution of the tx.
interpreter *Interpreter
// abort is used to abort the EVM calling operations
// NOTE: must be set atomically
abort int32
// callGasTemp holds the gas available for the current call. This is needed because the
// available gas is calculated in gasCall* according to the 63/64 rule and later
// applied in opCall*.
callGasTemp uint64
}
// NewEVM returns a new EVM. The returned EVM is not thread safe and should
// only ever be used *once*.
func NewEVM(ctx Context, am AccountManager, vmConfig Config) *EVM {
evm := &EVM{
Context: ctx,
am: am,
vmConfig: vmConfig,
}
evm.interpreter = NewInterpreter(evm, vmConfig)
return evm
}
// Cancel cancels any running EVM operation. This may be called concurrently and
// it's safe to be called multiple times.
func (evm *EVM) Cancel() {
atomic.StoreInt32(&evm.abort, 1)
}
// Call executes the contract associated with the addr with the given input as
// parameters. It also handles any necessary value transfer required and takes
// the necessary steps to create accounts and reverses the state in case of an
// execution error or failed value transfer.
func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
// Fail if we're trying to transfer more than the available balance
if !evm.Context.CanTransfer(evm.am, caller.GetAddress(), value) {
return nil, gas, ErrInsufficientBalance
}
contractAccount := evm.am.GetAccount(addr)
code, err := contractAccount.GetCode()
if err != nil {
return nil, gas, ErrContractCodeLoadFail
}
var (
to = AccountRef(addr)
snapshot = evm.am.Snapshot()
)
if len(code) == 0 && PrecompiledContracts[addr] == nil && value.Sign() == 0 {
return nil, gas, nil
}
evm.Transfer(evm.am, caller.GetAddress(), to.GetAddress(), value)
// Initialise a new contract and set the code that is to be used by the EVM.
// The contract is a scoped environment for this execution context only.
contract := NewContract(caller, to, value, gas)
contract.SetCallCode(&addr, contractAccount.GetCodeHash(), code)
start := time.Now()
// Capture the tracer start/end events in debug mode
if evm.vmConfig.Debug && evm.depth == 0 {
evm.vmConfig.Tracer.CaptureStart(caller.GetAddress(), addr, false, input, gas, value)
defer func() { // Lazy evaluation of the parameters
evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err)
}()
}
ret, err = run(evm, contract, input)
// When an error was returned by the EVM or when setting the creation code
// above we revert to the snapshot and consume any gas remaining. Additionally
// when we're in homestead this also counts for code storage gas errors.
if err != nil {
log.Errorf("evm error:", err)
evm.am.RevertToSnapshot(snapshot)
if err != errExecutionReverted {
contract.UseGas(contract.Gas)
}
}
return ret, contract.Gas, err
}
type AssetDb interface {
GetAssetCode(code common.Hash) (common.Address, error)
}
// TransferAssetTx
func (evm *EVM) TransferAssetTx(caller ContractRef, addr common.Address, gas uint64, txData []byte, assetDB AssetDb) (ret []byte, leftOverGas uint64, Err, vmErr error) {
tradingAsset, err := types.GetTradingAsset(txData)
if err != nil {
log.Errorf("Unmarshal transfer asset data err: %s", err)
return nil, gas, err, nil
}
assetId := tradingAsset.AssetId
amount := tradingAsset.Value
input := tradingAsset.Input
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil, nil
}
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, nil, ErrDepth
}
senderAcc := evm.am.GetAccount(caller.GetAddress())
senderEquity, err := senderAcc.GetEquityState(assetId)
if err != nil {
return nil, gas, err, nil
}
if amount == nil || senderEquity.Equity == nil || senderEquity.Equity.Cmp(big.NewInt(0)) <= 0 {
return nil, gas, ErrAssetEquity, nil
}
// get asset
issuer, err := assetDB.GetAssetCode(senderEquity.AssetCode)
if err != nil {
return nil, gas, err, nil
}
issuerAcc := evm.am.GetAccount(issuer)
freeze, err := issuerAcc.GetAssetCodeState(senderEquity.AssetCode, types.AssetFreeze)
if err == nil && freeze == "true" {
return nil, gas, ErrTransferFrozenAsset, nil
}
asset, err := issuerAcc.GetAssetCode(senderEquity.AssetCode)
if err != nil {
return nil, gas, err, nil
}
// Fail if we're trying to transfer more than the available balance
if senderEquity.Equity.Cmp(amount) < 0 && asset.IsDivisible {
log.Errorf("Sender equity:%s, transaction amount:%s, asset.IsDivisible:%s", senderEquity.Equity.String(), amount.String(), strconv.FormatBool(asset.IsDivisible))
return nil, gas, ErrInsufficientBalance, nil
}
contractAccount := evm.am.GetAccount(addr)
code, err := contractAccount.GetCode()
if err != nil {
return nil, gas, ErrContractCodeLoadFail, nil
}
var (
to = AccountRef(addr)
snapshot = evm.am.Snapshot()
)
if len(code) == 0 && PrecompiledContracts[addr] == nil && amount.Sign() == 0 {
return nil, gas, nil, nil
}
// if to == 0, then destruction of assets
destroyAsset := addr == common.BytesToAddress([]byte{0})
// Transfer assetId balance
// if isDivisible == false,then we should set the amount equal to the balance value of assetId
if !asset.IsDivisible {
amount = senderEquity.Equity
}
if !destroyAsset {
toEquity, err := contractAccount.GetEquityState(assetId)
if err != nil && err == store.ErrNotExist { // not exist this kind of assetId
// set new assetEquity for to
newToEquity := senderEquity.Clone()
newToEquity.Equity = amount
err = contractAccount.SetEquityState(assetId, newToEquity)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
return nil, gas, err, nil
}
} else if err != nil && err != store.ErrNotExist { // other err
evm.am.RevertToSnapshot(snapshot)
return nil, gas, err, nil
} else { // err == nil
// add assetId's balance of to
newToEquity := toEquity.Clone()
newToEquity.Equity = new(big.Int).Add(newToEquity.Equity, amount)
err = contractAccount.SetEquityState(assetId, newToEquity)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
return nil, gas, err, nil
}
}
} else {
// reduce totalSupply
var oldTotalSupply *big.Int
var newTotalSupply *big.Int
oldTotalSupply, err = issuerAcc.GetAssetCodeTotalSupply(senderEquity.AssetCode)
if err != nil {
return nil, gas, err, nil
}
if asset.IsDivisible {
newTotalSupply = new(big.Int).Sub(oldTotalSupply, amount)
} else {
newTotalSupply = new(big.Int).Sub(oldTotalSupply, big.NewInt(1))
}
err = issuerAcc.SetAssetCodeTotalSupply(senderEquity.AssetCode, newTotalSupply)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
return nil, gas, err, nil
}
}
// reduce sender's asset
newSenderEquity := senderEquity.Clone()
newSenderEquity.Equity = new(big.Int).Sub(newSenderEquity.Equity, amount)
if newSenderEquity.Equity.Cmp(big.NewInt(0)) == 0 {
// if assetId's balance == 0,then delete this kind of assetId
err = senderAcc.SetEquityState(assetId, nil)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
return nil, gas, err, nil
}
} else { // set new assetEquity for sender
err = senderAcc.SetEquityState(assetId, newSenderEquity)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
return nil, gas, err, nil
}
}
// Initialise a new contract and set the code that is to be used by the EVM.
// The contract is a scoped environment for this execution context only.
contract := NewContract(caller, to, amount, gas)
contract.SetCallCode(&addr, contractAccount.GetCodeHash(), code)
start := time.Now()
// Capture the tracer start/end events in debug mode
if evm.vmConfig.Debug && evm.depth == 0 {
evm.vmConfig.Tracer.CaptureStart(caller.GetAddress(), addr, false, input, gas, nil)
defer func() { // Lazy evaluation of the parameters
evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err)
}()
}
ret, err = run(evm, contract, input)
// When an error was returned by the EVM or when setting the creation code
// above we revert to the snapshot and consume any gas remaining. Additionally
// when we're in homestead this also counts for code storage gas errors.
if err != nil {
evm.am.RevertToSnapshot(snapshot)
if err != errExecutionReverted {
contract.UseGas(contract.Gas)
}
}
return ret, contract.Gas, nil, err
}
// CallCode executes the contract associated with the addr with the given input
// as parameters. It also handles any necessary value transfer required and takes
// the necessary steps to create accounts and reverses the state in case of an
// execution error or failed value transfer.
//
// CallCode differs from Call in the sense that it executes the given address'
// code with the caller as context.
func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
// Fail if we're trying to transfer more than the available balance
if !evm.CanTransfer(evm.am, caller.GetAddress(), value) {
return nil, gas, ErrInsufficientBalance
}
contractAccount := evm.am.GetAccount(addr)
code, err := contractAccount.GetCode()
if err != nil {
return nil, gas, ErrContractCodeLoadFail
}
var (
snapshot = evm.am.Snapshot()
to = AccountRef(caller.GetAddress())
)
// initialise a new contract and set the code that is to be used by the
// EVM. The contract is a scoped environment for this execution context
// only.
contract := NewContract(caller, to, value, gas)
contract.SetCallCode(&addr, contractAccount.GetCodeHash(), code)
ret, err = run(evm, contract, input)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
if err != errExecutionReverted {
contract.UseGas(contract.Gas)
}
}
return ret, contract.Gas, err
}
// DelegateCall executes the contract associated with the addr with the given input
// as parameters. It reverses the state in case of an execution error.
//
// DelegateCall differs from CallCode in the sense that it executes the given address'
// code with the caller as context and the caller is set to the caller of the caller.
func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
contractAccount := evm.am.GetAccount(addr)
code, err := contractAccount.GetCode()
if err != nil {
return nil, gas, ErrContractCodeLoadFail
}
var (
snapshot = evm.am.Snapshot()
to = AccountRef(caller.GetAddress())
)
// Initialise a new contract and make initialise the delegate values
contract := NewContract(caller, to, nil, gas).AsDelegate()
contract.SetCallCode(&addr, contractAccount.GetCodeHash(), code)
ret, err = run(evm, contract, input)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
if err != errExecutionReverted {
contract.UseGas(contract.Gas)
}
}
return ret, contract.Gas, err
}
// StaticCall executes the contract associated with the addr with the given input
// as parameters while disallowing any modifications to the state during the call.
// Opcodes that attempt to perform such modifications will result in exceptions
// instead of performing the modifications.
func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
// Make sure the readonly is only set if we aren't in readonly yet
// this makes also sure that the readonly flag isn't removed for
// child calls.
if !evm.interpreter.readOnly {
evm.interpreter.readOnly = true
defer func() { evm.interpreter.readOnly = false }()
}
contractAccount := evm.am.GetAccount(addr)
code, err := contractAccount.GetCode()
if err != nil {
return nil, gas, ErrContractCodeLoadFail
}
var (
to = AccountRef(addr)
snapshot = evm.am.Snapshot()
)
// Initialise a new contract and set the code that is to be used by the
// EVM. The contract is a scoped environment for this execution context
// only.
contract := NewContract(caller, to, new(big.Int), gas)
contract.SetCallCode(&addr, contractAccount.GetCodeHash(), code)
// When an error was returned by the EVM or when setting the creation code
// above we revert to the snapshot and consume any gas remaining. Additionally
// when we're in Homestead this also counts for code storage gas errors.
ret, err = run(evm, contract, input)
if err != nil {
evm.am.RevertToSnapshot(snapshot)
if err != errExecutionReverted {
contract.UseGas(contract.Gas)
}
}
return ret, contract.Gas, err
}
// Create creates a new contract using code as deployment code.
func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
// Depth check execution. Fail if we're trying to execute above the
// limit.
if evm.depth > int(params.CallCreateDepth) {
return nil, common.Address{}, gas, ErrDepth
}
if !evm.CanTransfer(evm.am, caller.GetAddress(), value) {
return nil, common.Address{}, gas, ErrInsufficientBalance
}
// Ensure there's no existing contract already at the designated address
contractAddr = crypto.CreateContractAddress(caller.GetAddress(), evm.TxHash)
// print out the contract address
log.Warnf("Created the contract address = %v", contractAddr.String())
contractAccount := evm.am.GetAccount(contractAddr)
if !contractAccount.IsEmpty() {
return nil, common.Address{}, 0, ErrContractAddressCollision
}
// Create a new account on the state
snapshot := evm.am.Snapshot()
// Add event to store the creation address.
evm.AddEvent(contractAddr, []common.Hash{types.TopicContractCreation}, []byte{})
evm.Transfer(evm.am, caller.GetAddress(), contractAddr, value)
// initialise a new contract and set the code that is to be used by the
// EVM. The contract is a scoped environment for this execution context
// only.
contract := NewContract(caller, AccountRef(contractAddr), value, gas)
contract.SetCallCode(&contractAddr, crypto.Keccak256Hash(code), code)
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, contractAddr, gas, nil
}
if evm.vmConfig.Debug && evm.depth == 0 {
evm.vmConfig.Tracer.CaptureStart(caller.GetAddress(), contractAddr, true, code, gas, value)
}
start := time.Now()
ret, err = run(evm, contract, nil)
// check whether the max code size has been exceeded
maxCodeSizeExceeded := len(ret) > params.MaxCodeSize
// if the contract creation ran successfully and no errors were returned
// calculate the gas required to store the code. If the code could not
// be stored due to not enough gas set an error and let it be handled
// by the error checking condition below.
if err == nil && !maxCodeSizeExceeded {
createDataGas := uint64(len(ret)) * params.CreateDataGas
if contract.UseGas(createDataGas) {
contractAccount.SetCode(types.Code(ret))
} else {
err = ErrCodeStoreOutOfGas
}
}
// When an error was returned by the EVM or when setting the creation code
// above we revert to the snapshot and consume any gas remaining. Additionally
// when we're in homestead this also counts for code storage gas errors.
if maxCodeSizeExceeded || err != nil {
evm.am.RevertToSnapshot(snapshot)
if err != errExecutionReverted {
contract.UseGas(contract.Gas)
}
}
// Assign err if contract code size exceeds the max while the err is still empty.
if maxCodeSizeExceeded && err == nil {
err = errMaxCodeSizeExceeded
}
if err != nil && err != ErrInsufficientBalance {
// Add event to record the error information.
evm.AddEvent(contractAddr, []common.Hash{types.TopicRunFail}, []byte{})
}
if evm.vmConfig.Debug && evm.depth == 0 {
evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err)
}
return ret, contractAddr, contract.Gas, err
}
// Interpreter returns the EVM interpreter
func (evm *EVM) Interpreter() *Interpreter { return evm.interpreter }
// AddEvent records the event during transaction's execution.
func (evm *EVM) AddEvent(address common.Address, topics []common.Hash, data []byte) {
evm.am.AddEvent(&types.Event{
Address: address,
Topics: topics,
Data: data,
// This is a non-consensus field, but assigned here because
// chain/account doesn't know the current block number.
TxIndex: evm.TxIndex,
TxHash: evm.TxHash,
// event.Term is set outside.
})
}