all: implement simple checkpoint syncing

accounts/abi/bind/backends/simulated.go

@@ -45,8 +45,10 @@ import (
 // This nil assignment ensures compile time that SimulatedBackend implements bind.ContractBackend.
 var _ bind.ContractBackend = (*SimulatedBackend)(nil)
 
-var errBlockNumberUnsupported = errors.New("SimulatedBackend cannot access blocks other than the latest block")
-var errGasEstimationFailed = errors.New("gas required exceeds allowance or always failing transaction")
+var (
+	errBlockNumberUnsupported = errors.New("simulatedBackend cannot access blocks other than the latest block")
+	errGasEstimationFailed    = errors.New("gas required exceeds allowance or always failing transaction")
+)
 
 // SimulatedBackend implements bind.ContractBackend, simulating a blockchain in
 // the background. Its main purpose is to allow easily testing contract bindings.
@@ -63,10 +65,9 @@ type SimulatedBackend struct {
 	config *params.ChainConfig
 }
 
-// NewSimulatedBackend creates a new binding backend using a simulated blockchain
-// for testing purposes.
-func NewSimulatedBackend(alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend {
-	database := rawdb.NewMemoryDatabase()
+// NewSimulatedBackendWithDatabase creates a new binding backend based on the given database
+// and uses a simulated blockchain for testing purposes.
+func NewSimulatedBackendWithDatabase(database ethdb.Database, alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend {
 	genesis := core.Genesis{Config: params.AllEthashProtocolChanges, GasLimit: gasLimit, Alloc: alloc}
 	genesis.MustCommit(database)
 	blockchain, _ := core.NewBlockChain(database, nil, genesis.Config, ethash.NewFaker(), vm.Config{}, nil)
@@ -81,6 +82,12 @@ func NewSimulatedBackend(alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBac
 	return backend
 }
 
+// NewSimulatedBackend creates a new binding backend using a simulated blockchain
+// for testing purposes.
+func NewSimulatedBackend(alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend {
+	return NewSimulatedBackendWithDatabase(rawdb.NewMemoryDatabase(), alloc, gasLimit)
+}
+
 // Commit imports all the pending transactions as a single block and starts a
 // fresh new state.
 func (b *SimulatedBackend) Commit() {
@@ -424,6 +431,11 @@ func (b *SimulatedBackend) AdjustTime(adjustment time.Duration) error {
 	return nil
 }
 
+// Blockchain returns the underlying blockchain.
+func (b *SimulatedBackend) Blockchain() *core.BlockChain {
+	return b.blockchain
+}
+
 // callmsg implements core.Message to allow passing it as a transaction simulator.
 type callmsg struct {
 	ethereum.CallMsg

accounts/abi/bind/bind_test.go

@@ -475,11 +475,12 @@ var bindTests = []struct {
 		`
 			"github.com/ethereum/go-ethereum/accounts/abi/bind"
 			"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
+			"github.com/ethereum/go-ethereum/core"
 			"github.com/ethereum/go-ethereum/common"
 		`,
 		`
 			// Create a simulator and wrap a non-deployed contract
-			sim := backends.NewSimulatedBackend(nil, uint64(10000000000))
+			sim := backends.NewSimulatedBackend(core.GenesisAlloc{}, uint64(10000000000))
 
 			nonexistent, err := NewNonExistent(common.Address{}, sim)
 			if err != nil {

accounts/abi/bind/template.go

@@ -439,6 +439,18 @@ var (
 				}
 			}), nil
 		}
+
+		// Parse{{.Normalized.Name}} is a log parse operation binding the contract event 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Filterer) Parse{{.Normalized.Name}}(log types.Log) (*{{$contract.Type}}{{.Normalized.Name}}, error) {
+			event := new({{$contract.Type}}{{.Normalized.Name}})
+			if err := _{{$contract.Type}}.contract.UnpackLog(event, "{{.Original.Name}}", log); err != nil {
+				return nil, err
+			}
+			return event, nil
+		}
+
  	{{end}}
 {{end}}
 `

accounts/abi/bind/util_test.go

@@ -56,7 +56,8 @@ func TestWaitDeployed(t *testing.T) {
 		backend := backends.NewSimulatedBackend(
 			core.GenesisAlloc{
 				crypto.PubkeyToAddress(testKey.PublicKey): {Balance: big.NewInt(10000000000)},
-			}, 10000000,
+			},
+			10000000,
 		)
 
 		// Create the transaction.

cmd/checkpoint-admin/common.go

@@ -0,0 +1,166 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"io/ioutil"
+	"strconv"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/console"
+	"github.com/ethereum/go-ethereum/contracts/checkpointoracle"
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rpc"
+	"gopkg.in/urfave/cli.v1"
+)
+
+// newClient creates a client with specified remote URL.
+func newClient(ctx *cli.Context) *ethclient.Client {
+	client, err := ethclient.Dial(ctx.GlobalString(nodeURLFlag.Name))
+	if err != nil {
+		utils.Fatalf("Failed to connect to Ethereum node: %v", err)
+	}
+	return client
+}
+
+// newRPCClient creates a rpc client with specified node URL.
+func newRPCClient(url string) *rpc.Client {
+	client, err := rpc.Dial(url)
+	if err != nil {
+		utils.Fatalf("Failed to connect to Ethereum node: %v", err)
+	}
+	return client
+}
+
+// getContractAddr retrieves the register contract address through
+// rpc request.
+func getContractAddr(client *rpc.Client) common.Address {
+	var addr string
+	if err := client.Call(&addr, "les_getCheckpointContractAddress"); err != nil {
+		utils.Fatalf("Failed to fetch checkpoint oracle address: %v", err)
+	}
+	return common.HexToAddress(addr)
+}
+
+// getCheckpoint retrieves the specified checkpoint or the latest one
+// through rpc request.
+func getCheckpoint(ctx *cli.Context, client *rpc.Client) *params.TrustedCheckpoint {
+	var checkpoint *params.TrustedCheckpoint
+
+	if ctx.GlobalIsSet(indexFlag.Name) {
+		var result [3]string
+		index := uint64(ctx.GlobalInt64(indexFlag.Name))
+		if err := client.Call(&result, "les_getCheckpoint", index); err != nil {
+			utils.Fatalf("Failed to get local checkpoint %v, please ensure the les API is exposed", err)
+		}
+		checkpoint = &params.TrustedCheckpoint{
+			SectionIndex: index,
+			SectionHead:  common.HexToHash(result[0]),
+			CHTRoot:      common.HexToHash(result[1]),
+			BloomRoot:    common.HexToHash(result[2]),
+		}
+	} else {
+		var result [4]string
+		err := client.Call(&result, "les_latestCheckpoint")
+		if err != nil {
+			utils.Fatalf("Failed to get local checkpoint %v, please ensure the les API is exposed", err)
+		}
+		index, err := strconv.ParseUint(result[0], 0, 64)
+		if err != nil {
+			utils.Fatalf("Failed to parse checkpoint index %v", err)
+		}
+		checkpoint = &params.TrustedCheckpoint{
+			SectionIndex: index,
+			SectionHead:  common.HexToHash(result[1]),
+			CHTRoot:      common.HexToHash(result[2]),
+			BloomRoot:    common.HexToHash(result[3]),
+		}
+	}
+	return checkpoint
+}
+
+// newContract creates a registrar contract instance with specified
+// contract address or the default contracts for mainnet or testnet.
+func newContract(client *rpc.Client) (common.Address, *checkpointoracle.CheckpointOracle) {
+	addr := getContractAddr(client)
+	if addr == (common.Address{}) {
+		utils.Fatalf("No specified registrar contract address")
+	}
+	contract, err := checkpointoracle.NewCheckpointOracle(addr, ethclient.NewClient(client))
+	if err != nil {
+		utils.Fatalf("Failed to setup registrar contract %s: %v", addr, err)
+	}
+	return addr, contract
+}
+
+// promptPassphrase prompts the user for a passphrase.
+// Set confirmation to true to require the user to confirm the passphrase.
+func promptPassphrase(confirmation bool) string {
+	passphrase, err := console.Stdin.PromptPassword("Passphrase: ")
+	if err != nil {
+		utils.Fatalf("Failed to read passphrase: %v", err)
+	}
+
+	if confirmation {
+		confirm, err := console.Stdin.PromptPassword("Repeat passphrase: ")
+		if err != nil {
+			utils.Fatalf("Failed to read passphrase confirmation: %v", err)
+		}
+		if passphrase != confirm {
+			utils.Fatalf("Passphrases do not match")
+		}
+	}
+	return passphrase
+}
+
+// getPassphrase obtains a passphrase given by the user. It first checks the
+// --password command line flag and ultimately prompts the user for a
+// passphrase.
+func getPassphrase(ctx *cli.Context) string {
+	passphraseFile := ctx.String(utils.PasswordFileFlag.Name)
+	if passphraseFile != "" {
+		content, err := ioutil.ReadFile(passphraseFile)
+		if err != nil {
+			utils.Fatalf("Failed to read passphrase file '%s': %v",
+				passphraseFile, err)
+		}
+		return strings.TrimRight(string(content), "\r\n")
+	}
+	// Otherwise prompt the user for the passphrase.
+	return promptPassphrase(false)
+}
+
+// getKey retrieves the user key through specified key file.
+func getKey(ctx *cli.Context) *keystore.Key {
+	// Read key from file.
+	keyFile := ctx.GlobalString(keyFileFlag.Name)
+	keyJson, err := ioutil.ReadFile(keyFile)
+	if err != nil {
+		utils.Fatalf("Failed to read the keyfile at '%s': %v", keyFile, err)
+	}
+	// Decrypt key with passphrase.
+	passphrase := getPassphrase(ctx)
+	key, err := keystore.DecryptKey(keyJson, passphrase)
+	if err != nil {
+		utils.Fatalf("Failed to decrypt user key '%s': %v", keyFile, err)
+	}
+	return key
+}