1package eth
  2
  3import (
  4	"context"
  5	"fmt"
  6	"math/big"
  7	"time"
  8
  9	"github.com/ethereum/go-ethereum/accounts"
 10	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 11	ethKeystore "github.com/ethereum/go-ethereum/accounts/keystore"
 12	ethCommon "github.com/ethereum/go-ethereum/common"
 13	"github.com/ethereum/go-ethereum/core/types"
 14	"github.com/ethereum/go-ethereum/ethclient"
 15	"github.com/hermeznetwork/hermez-node/common"
 16	HEZ "github.com/hermeznetwork/hermez-node/eth/contracts/tokenHEZ"
 17	"github.com/hermeznetwork/hermez-node/log"
 18	"github.com/hermeznetwork/tracerr"
 19)
 20
 21// ERC20Consts are the constants defined in a particular ERC20 Token instance
 22type ERC20Consts struct {
 23	Name     string
 24	Symbol   string
 25	Decimals uint64
 26}
 27
 28// EthereumInterface is the interface to Ethereum
 29type EthereumInterface interface {
 30	EthLastBlock() (int64, error)
 31	// EthHeaderByNumber(context.Context, *big.Int) (*types.Header, error)
 32	EthBlockByNumber(context.Context, int64) (*common.Block, error)
 33	EthAddress() (*ethCommon.Address, error)
 34	EthTransactionReceipt(context.Context, ethCommon.Hash) (*types.Receipt, error)
 35
 36	EthERC20Consts(ethCommon.Address) (*ERC20Consts, error)
 37}
 38
 39var (
 40	// ErrAccountNil is used when the calls can not be made because the account is nil
 41	ErrAccountNil = fmt.Errorf("Authorized calls can't be made when the account is nil")
 42	// ErrReceiptStatusFailed is used when receiving a failed transaction
 43	ErrReceiptStatusFailed = fmt.Errorf("receipt status is failed")
 44	// ErrReceiptNotReceived is used when unable to retrieve a transaction
 45	ErrReceiptNotReceived = fmt.Errorf("receipt not available")
 46	// ErrBlockHashMismatchEvent is used when there's a block hash mismatch
 47	// beetween different events of the same block
 48	ErrBlockHashMismatchEvent = fmt.Errorf("block hash mismatch in event log")
 49)
 50
 51const (
 52	errStrDeploy      = "deployment of %s failed: %w"
 53	errStrWaitReceipt = "wait receipt of %s deploy failed: %w"
 54
 55	// default values
 56	defaultCallGasLimit        = 300000
 57	defaultDeployGasLimit      = 1000000
 58	defaultGasPriceDiv         = 100
 59	defaultReceiptTimeout      = 60
 60	defaultIntervalReceiptLoop = 200
 61)
 62
 63// EthereumConfig defines the configuration parameters of the EthereumClient
 64type EthereumConfig struct {
 65	CallGasLimit        uint64
 66	DeployGasLimit      uint64
 67	GasPriceDiv         uint64
 68	ReceiptTimeout      time.Duration
 69	IntervalReceiptLoop time.Duration
 70}
 71
 72// EthereumClient is an ethereum client to call Smart Contract methods and check blockchain information.
 73type EthereumClient struct {
 74	client         *ethclient.Client
 75	account        *accounts.Account
 76	ks             *ethKeystore.KeyStore
 77	ReceiptTimeout time.Duration
 78	config         *EthereumConfig
 79	opts           *bind.CallOpts
 80}
 81
 82// NewEthereumClient creates a EthereumClient instance.  The account is not mandatory (it can
 83// be nil).  If the account is nil, CallAuth will fail with ErrAccountNil.
 84func NewEthereumClient(client *ethclient.Client, account *accounts.Account, ks *ethKeystore.KeyStore, config *EthereumConfig) *EthereumClient {
 85	if config == nil {
 86		config = &EthereumConfig{
 87			CallGasLimit:        defaultCallGasLimit,
 88			DeployGasLimit:      defaultDeployGasLimit,
 89			GasPriceDiv:         defaultGasPriceDiv,
 90			ReceiptTimeout:      defaultReceiptTimeout,
 91			IntervalReceiptLoop: defaultIntervalReceiptLoop,
 92		}
 93	}
 94	return &EthereumClient{
 95		client:         client,
 96		account:        account,
 97		ks:             ks,
 98		ReceiptTimeout: config.ReceiptTimeout * time.Second,
 99		config:         config,
100		opts:           newCallOpts(),
101	}
102}
103
104// BalanceAt retieves information about the default account
105func (c *EthereumClient) BalanceAt(addr ethCommon.Address) (*big.Int, error) {
106	return c.client.BalanceAt(context.TODO(), addr, nil)
107}
108
109// Account returns the underlying ethereum account
110func (c *EthereumClient) Account() *accounts.Account {
111	return c.account
112}
113
114// EthAddress returns the ethereum address of the account loaded into the EthereumClient
115func (c *EthereumClient) EthAddress() (*ethCommon.Address, error) {
116	if c.account == nil {
117		return nil, tracerr.Wrap(ErrAccountNil)
118	}
119	return &c.account.Address, nil
120}
121
122// CallAuth performs a Smart Contract method call that requires authorization.
123// This call requires a valid account with Ether that can be spend during the
124// call.
125func (c *EthereumClient) CallAuth(gasLimit uint64,
126	fn func(*ethclient.Client, *bind.TransactOpts) (*types.Transaction, error)) (*types.Transaction, error) {
127	if c.account == nil {
128		return nil, tracerr.Wrap(ErrAccountNil)
129	}
130
131	gasPrice, err := c.client.SuggestGasPrice(context.Background())
132	if err != nil {
133		return nil, tracerr.Wrap(err)
134	}
135	inc := new(big.Int).Set(gasPrice)
136	inc.Div(inc, new(big.Int).SetUint64(c.config.GasPriceDiv))
137	gasPrice.Add(gasPrice, inc)
138	log.Debugw("Transaction metadata", "gasPrice", gasPrice)
139
140	auth, err := bind.NewKeyStoreTransactor(c.ks, *c.account)
141	if err != nil {
142		return nil, tracerr.Wrap(err)
143	}
144	auth.Value = big.NewInt(0) // in wei
145	if gasLimit == 0 {
146		auth.GasLimit = c.config.CallGasLimit // in units
147	} else {
148		auth.GasLimit = gasLimit // in units
149	}
150	auth.GasPrice = gasPrice
151
152	tx, err := fn(c.client, auth)
153	if tx != nil {
154		log.Debugw("Transaction", "tx", tx.Hash().Hex(), "nonce", tx.Nonce())
155	}
156	return tx, tracerr.Wrap(err)
157}
158
159// ContractData contains the contract data
160type ContractData struct {
161	Address ethCommon.Address
162	Tx      *types.Transaction
163	Receipt *types.Receipt
164}
165
166// Deploy a smart contract.  `name` is used to log deployment information.  fn
167// is a wrapper to the deploy function generated by abigen.  In case of error,
168// the returned `ContractData` may have some parameters filled depending on the
169// kind of error that occurred.
170func (c *EthereumClient) Deploy(name string,
171	fn func(c *ethclient.Client, auth *bind.TransactOpts) (ethCommon.Address, *types.Transaction, interface{}, error)) (ContractData, error) {
172	var contractData ContractData
173	log.Infow("Deploying", "contract", name)
174	tx, err := c.CallAuth(
175		c.config.DeployGasLimit,
176		func(client *ethclient.Client, auth *bind.TransactOpts) (*types.Transaction, error) {
177			addr, tx, _, err := fn(client, auth)
178			if err != nil {
179				return nil, tracerr.Wrap(err)
180			}
181			contractData.Address = addr
182			return tx, nil
183		},
184	)
185	if err != nil {
186		return contractData, tracerr.Wrap(fmt.Errorf(errStrDeploy, name, err))
187	}
188	log.Infow("Waiting receipt", "tx", tx.Hash().Hex(), "contract", name)
189	contractData.Tx = tx
190	receipt, err := c.WaitReceipt(tx)
191	if err != nil {
192		return contractData, tracerr.Wrap(fmt.Errorf(errStrWaitReceipt, name, err))
193	}
194	contractData.Receipt = receipt
195	return contractData, nil
196}
197
198// Call performs a read only Smart Contract method call.
199func (c *EthereumClient) Call(fn func(*ethclient.Client) error) error {
200	return fn(c.client)
201}
202
203// WaitReceipt will block until a transaction is confirmed.  Internally it
204// polls the state every 200 milliseconds.
205func (c *EthereumClient) WaitReceipt(tx *types.Transaction) (*types.Receipt, error) {
206	return c.waitReceipt(context.TODO(), tx, c.ReceiptTimeout)
207}
208
209// GetReceipt will check if a transaction is confirmed and return
210// immediately, waiting at most 1 second and returning error if the transaction
211// is still pending.
212func (c *EthereumClient) GetReceipt(tx *types.Transaction) (*types.Receipt, error) {
213	ctx, cancel := context.WithTimeout(context.TODO(), 1*time.Second)
214	defer cancel()
215	return c.waitReceipt(ctx, tx, 0)
216}
217
218// EthTransactionReceipt returns the transaction receipt of the given txHash
219func (c *EthereumClient) EthTransactionReceipt(ctx context.Context, txHash ethCommon.Hash) (*types.Receipt, error) {
220	return c.client.TransactionReceipt(ctx, txHash)
221}
222
223func (c *EthereumClient) waitReceipt(ctx context.Context, tx *types.Transaction, timeout time.Duration) (*types.Receipt, error) {
224	var err error
225	var receipt *types.Receipt
226
227	txHash := tx.Hash()
228	log.Debugw("Waiting for receipt", "tx", txHash.Hex())
229
230	start := time.Now()
231	for {
232		receipt, err = c.client.TransactionReceipt(ctx, txHash)
233		if receipt != nil || time.Since(start) >= timeout {
234			break
235		}
236		time.Sleep(c.config.IntervalReceiptLoop * time.Millisecond)
237	}
238
239	if receipt != nil && receipt.Status == types.ReceiptStatusFailed {
240		log.Errorw("Failed transaction", "tx", txHash.Hex())
241		return receipt, tracerr.Wrap(ErrReceiptStatusFailed)
242	}
243
244	if receipt == nil {
245		log.Debugw("Pendingtransaction / Wait receipt timeout", "tx", txHash.Hex(), "lasterr", err)
246		return receipt, tracerr.Wrap(ErrReceiptNotReceived)
247	}
248	log.Debugw("Successful transaction", "tx", txHash.Hex())
249
250	return receipt, tracerr.Wrap(err)
251}
252
253// EthLastBlock returns the last block number in the blockchain
254func (c *EthereumClient) EthLastBlock() (int64, error) {
255	ctx, cancel := context.WithTimeout(context.TODO(), 1*time.Second)
256	defer cancel()
257	header, err := c.client.HeaderByNumber(ctx, nil)
258	if err != nil {
259		return 0, tracerr.Wrap(err)
260	}
261	return header.Number.Int64(), nil
262}
263
264// EthHeaderByNumber internally calls ethclient.Client HeaderByNumber
265// func (c *EthereumClient) EthHeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error) {
266// 	return c.client.HeaderByNumber(ctx, number)
267// }
268
269// EthBlockByNumber internally calls ethclient.Client BlockByNumber and returns
270// *common.Block.  If number == -1, the latests known block is returned.
271func (c *EthereumClient) EthBlockByNumber(ctx context.Context, number int64) (*common.Block, error) {
272	blockNum := big.NewInt(number)
273	if number == -1 {
274		blockNum = nil
275	}
276	block, err := c.client.BlockByNumber(ctx, blockNum)
277	if err != nil {
278		return nil, tracerr.Wrap(err)
279	}
280	b := &common.Block{
281		Num:        block.Number().Int64(),
282		Timestamp:  time.Unix(int64(block.Time()), 0),
283		ParentHash: block.ParentHash(),
284		Hash:       block.Hash(),
285	}
286	return b, nil
287}
288
289// EthERC20Consts returns the constants defined for a particular ERC20 Token instance.
290func (c *EthereumClient) EthERC20Consts(tokenAddress ethCommon.Address) (*ERC20Consts, error) {
291	// We use the HEZ token smart contract interfacehere because it's an
292	// ERC20, which allows us to access the standard ERC20 constants.
293	instance, err := HEZ.NewHEZ(tokenAddress, c.client)
294	if err != nil {
295		return nil, tracerr.Wrap(err)
296	}
297	name, err := instance.Name(c.opts)
298	if err != nil {
299		return nil, tracerr.Wrap(err)
300	}
301
302	symbol, err := instance.Symbol(c.opts)
303	if err != nil {
304		return nil, tracerr.Wrap(err)
305	}
306
307	decimals, err := instance.Decimals(c.opts)
308	if err != nil {
309		return nil, tracerr.Wrap(err)
310	}
311	return &ERC20Consts{
312		Name:     name,
313		Symbol:   symbol,
314		Decimals: uint64(decimals),
315	}, nil
316}
317
318// Client returns the internal ethclient.Client
319func (c *EthereumClient) Client() *ethclient.Client {
320	return c.client
321}
322
323// newCallOpts returns a CallOpts to be used in ethereum calls with a non-zero
324// From address.  This is a workaround for a bug in ethereumjs-vm that shows up
325// in ganache: https://github.com/hermeznetwork/hermez-node/issues/317
326func newCallOpts() *bind.CallOpts {
327	return &bind.CallOpts{
328		From: ethCommon.HexToAddress("0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f"),
329	}
330}