core/vm/runtime: added simple execution runtime

The runtime environment can be used for simple basic execution of
contract code without the requirement of setting up a full stack and
operates fully in memory.

5 files changed, 399 insertions, 0 deletions

diff --git a/core/vm/runtime/doc.go b/core/vm/runtime/doc.go
new file mode 100644
index 000000000..a3b464a7d
--- /dev/null
+++ b/core/vm/runtime/doc.go
@@ -0,0 +1,18 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package runtime provides a basic execution model for executing EVM code.
+package runtime
diff --git a/core/vm/runtime/env.go b/core/vm/runtime/env.go
new file mode 100644
index 000000000..22f9ea14d
--- /dev/null
+++ b/core/vm/runtime/env.go
@@ -0,0 +1,106 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package runtime
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/vm"
+)
+
+// Env is a basic runtime environment required for running the EVM.
+type Env struct {
+	depth int
+	state *state.StateDB
+
+	origin   common.Address
+	coinbase common.Address
+
+	number     *big.Int
+	time       *big.Int
+	difficulty *big.Int
+	gasLimit   *big.Int
+
+	logs []vm.StructLog
+
+	getHashFn func(uint64) common.Hash
+}
+
+// NewEnv returns a new vm.Environment
+func NewEnv(cfg *Config, state *state.StateDB) vm.Environment {
+	return &Env{
+		state:      state,
+		origin:     cfg.Origin,
+		coinbase:   cfg.Coinbase,
+		number:     cfg.BlockNumber,
+		time:       cfg.Time,
+		difficulty: cfg.Difficulty,
+		gasLimit:   cfg.GasLimit,
+	}
+}
+
+func (self *Env) StructLogs() []vm.StructLog {
+	return self.logs
+}
+
+func (self *Env) AddStructLog(log vm.StructLog) {
+	self.logs = append(self.logs, log)
+}
+
+func (self *Env) Origin() common.Address   { return self.origin }
+func (self *Env) BlockNumber() *big.Int    { return self.number }
+func (self *Env) Coinbase() common.Address { return self.coinbase }
+func (self *Env) Time() *big.Int           { return self.time }
+func (self *Env) Difficulty() *big.Int     { return self.difficulty }
+func (self *Env) Db() vm.Database          { return self.state }
+func (self *Env) GasLimit() *big.Int       { return self.gasLimit }
+func (self *Env) VmType() vm.Type          { return vm.StdVmTy }
+func (self *Env) GetHash(n uint64) common.Hash {
+	return self.getHashFn(n)
+}
+func (self *Env) AddLog(log *vm.Log) {
+	self.state.AddLog(log)
+}
+func (self *Env) Depth() int     { return self.depth }
+func (self *Env) SetDepth(i int) { self.depth = i }
+func (self *Env) CanTransfer(from common.Address, balance *big.Int) bool {
+	return self.state.GetBalance(from).Cmp(balance) >= 0
+}
+func (self *Env) MakeSnapshot() vm.Database {
+	return self.state.Copy()
+}
+func (self *Env) SetSnapshot(copy vm.Database) {
+	self.state.Set(copy.(*state.StateDB))
+}
+
+func (self *Env) Transfer(from, to vm.Account, amount *big.Int) {
+	core.Transfer(from, to, amount)
+}
+
+func (self *Env) Call(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	return core.Call(self, caller, addr, data, gas, price, value)
+}
+func (self *Env) CallCode(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	return core.CallCode(self, caller, addr, data, gas, price, value)
+}
+
+func (self *Env) Create(caller vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) {
+	return core.Create(self, caller, data, gas, price, value)
+}
diff --git a/core/vm/runtime/runtime.go b/core/vm/runtime/runtime.go
new file mode 100644
index 000000000..dd3aa1b0b
--- /dev/null
+++ b/core/vm/runtime/runtime.go
@@ -0,0 +1,121 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package runtime
+
+import (
+	"math/big"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
+)
+
+// Config is a basic type specifing certain configuration flags for running
+// the EVM.
+type Config struct {
+	Difficulty  *big.Int
+	Origin      common.Address
+	Coinbase    common.Address
+	BlockNumber *big.Int
+	Time        *big.Int
+	GasLimit    *big.Int
+	GasPrice    *big.Int
+	Value       *big.Int
+	DisableJit  bool // "disable" so it's enabled by default
+	Debug       bool
+
+	GetHashFn func(n uint64) common.Hash
+}
+
+// sets defaults on the config
+func setDefaults(cfg *Config) {
+	if cfg.Difficulty == nil {
+		cfg.Difficulty = new(big.Int)
+	}
+	if cfg.Time == nil {
+		cfg.Time = big.NewInt(time.Now().Unix())
+	}
+	if cfg.GasLimit == nil {
+		cfg.GasLimit = new(big.Int).Set(common.MaxBig)
+	}
+	if cfg.GasPrice == nil {
+		cfg.GasPrice = new(big.Int)
+	}
+	if cfg.Value == nil {
+		cfg.Value = new(big.Int)
+	}
+	if cfg.BlockNumber == nil {
+		cfg.BlockNumber = new(big.Int)
+	}
+	if cfg.GetHashFn == nil {
+		cfg.GetHashFn = func(n uint64) common.Hash {
+			return common.BytesToHash(crypto.Sha3([]byte(new(big.Int).SetUint64(n).String())))
+		}
+	}
+}
+
+// Execute executes the code using the input as call data during the execution.
+// It returns the EVM's return value, the new state and an error if it failed.
+//
+// Executes sets up a in memory, temporarily, environment for the execution of
+// the given code. It enabled the JIT by default and make sure that it's restored
+// to it's original state afterwards.
+func Execute(code, input []byte, cfg *Config) ([]byte, *state.StateDB, error) {
+	if cfg == nil {
+		cfg = new(Config)
+	}
+	setDefaults(cfg)
+
+	// defer the call to setting back the original values
+	defer func(debug, forceJit, enableJit bool) {
+		vm.Debug = debug
+		vm.ForceJit = forceJit
+		vm.EnableJit = enableJit
+	}(vm.Debug, vm.ForceJit, vm.EnableJit)
+
+	vm.ForceJit = !cfg.DisableJit
+	vm.EnableJit = !cfg.DisableJit
+	vm.Debug = cfg.Debug
+
+	var (
+		db, _      = ethdb.NewMemDatabase()
+		statedb, _ = state.New(common.Hash{}, db)
+		vmenv      = NewEnv(cfg, statedb)
+		sender     = statedb.CreateAccount(cfg.Origin)
+		receiver   = statedb.CreateAccount(common.StringToAddress("contract"))
+	)
+	// set the receiver's (the executing contract) code for execution.
+	receiver.SetCode(code)
+
+	// Call the code with the given configuration.
+	ret, err := vmenv.Call(
+		sender,
+		receiver.Address(),
+		input,
+		cfg.GasLimit,
+		cfg.GasPrice,
+		cfg.Value,
+	)
+
+	if cfg.Debug {
+		vm.StdErrFormat(vmenv.StructLogs())
+	}
+	return ret, statedb, err
+}
diff --git a/core/vm/runtime/runtime_example_test.go b/core/vm/runtime/runtime_example_test.go
new file mode 100644
index 000000000..b7d0ddc38
--- /dev/null
+++ b/core/vm/runtime/runtime_example_test.go
@@ -0,0 +1,34 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package runtime_test
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/vm/runtime"
+)
+
+func ExampleExecute() {
+	ret, _, err := runtime.Execute(common.Hex2Bytes("6060604052600a8060106000396000f360606040526008565b00"), nil, nil)
+	if err != nil {
+		fmt.Println(err)
+	}
+	fmt.Println(ret)
+	// Output:
+	// [96 96 96 64 82 96 8 86 91 0]
+}
diff --git a/core/vm/runtime/runtime_test.go b/core/vm/runtime/runtime_test.go
new file mode 100644
index 000000000..773a0163e
--- /dev/null
+++ b/core/vm/runtime/runtime_test.go
@@ -0,0 +1,120 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library 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 Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package runtime
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/vm"
+)
+
+func TestDefaults(t *testing.T) {
+	cfg := new(Config)
+	setDefaults(cfg)
+
+	if cfg.Difficulty == nil {
+		t.Error("expected difficulty to be non nil")
+	}
+
+	if cfg.Time == nil {
+		t.Error("expected time to be non nil")
+	}
+	if cfg.GasLimit == nil {
+		t.Error("expected time to be non nil")
+	}
+	if cfg.GasPrice == nil {
+		t.Error("expected time to be non nil")
+	}
+	if cfg.Value == nil {
+		t.Error("expected time to be non nil")
+	}
+	if cfg.GetHashFn == nil {
+		t.Error("expected time to be non nil")
+	}
+	if cfg.BlockNumber == nil {
+		t.Error("expected block number to be non nil")
+	}
+}
+
+func TestEnvironment(t *testing.T) {
+	defer func() {
+		if r := recover(); r != nil {
+			t.Fatalf("crashed with: %v", r)
+		}
+	}()
+
+	Execute([]byte{
+		byte(vm.DIFFICULTY),
+		byte(vm.TIMESTAMP),
+		byte(vm.GASLIMIT),
+		byte(vm.PUSH1),
+		byte(vm.ORIGIN),
+		byte(vm.BLOCKHASH),
+		byte(vm.COINBASE),
+	}, nil, nil)
+}
+
+func TestRestoreDefaults(t *testing.T) {
+	Execute(nil, nil, &Config{Debug: true})
+	if vm.ForceJit {
+		t.Error("expected force jit to be disabled")
+	}
+
+	if vm.Debug {
+		t.Error("expected debug to be disabled")
+	}
+
+	if vm.EnableJit {
+		t.Error("expected jit to be disabled")
+	}
+}
+
+func BenchmarkCall(b *testing.B) {
+	var definition = `[{"constant":true,"inputs":[],"name":"seller","outputs":[{"name":"","type":"address"}],"type":"function"},{"constant":false,"inputs":[],"name":"abort","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"value","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[],"name":"refund","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"buyer","outputs":[{"name":"","type":"address"}],"type":"function"},{"constant":false,"inputs":[],"name":"confirmReceived","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"state","outputs":[{"name":"","type":"uint8"}],"type":"function"},{"constant":false,"inputs":[],"name":"confirmPurchase","outputs":[],"type":"function"},{"inputs":[],"type":"constructor"},{"anonymous":false,"inputs":[],"name":"Aborted","type":"event"},{"anonymous":false,"inputs":[],"name":"PurchaseConfirmed","type":"event"},{"anonymous":false,"inputs":[],"name":"ItemReceived","type":"event"},{"anonymous":false,"inputs":[],"name":"Refunded","type":"event"}]`
+
+	var code = common.Hex2Bytes("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")
+
+	abi, err := abi.JSON(strings.NewReader(definition))
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	cpurchase, err := abi.Pack("confirmPurchase")
+	if err != nil {
+		b.Fatal(err)
+	}
+	creceived, err := abi.Pack("confirmReceived")
+	if err != nil {
+		b.Fatal(err)
+	}
+	refund, err := abi.Pack("refund")
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		for j := 0; j < 400; j++ {
+			Execute(code, cpurchase, nil)
+			Execute(code, creceived, nil)
+			Execute(code, refund, nil)
+		}
+	}
+}