neo-go/pkg/core/interop_neo.go
2020-06-08 13:27:08 +03:00

358 lines
10 KiB
Go

package core
import (
"bytes"
"errors"
"fmt"
"sort"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/core/state"
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/vm"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
const (
// MaxContractDescriptionLen is the maximum length for contract description.
MaxContractDescriptionLen = 65536
// MaxContractScriptSize is the maximum script size for a contract.
MaxContractScriptSize = 1024 * 1024
// MaxContractParametersNum is the maximum number of parameters for a contract.
MaxContractParametersNum = 252
// MaxContractStringLen is the maximum length for contract metadata strings.
MaxContractStringLen = 252
)
// headerGetVersion returns version from the header.
func headerGetVersion(ic *interop.Context, v *vm.VM) error {
header, err := popHeaderFromVM(v)
if err != nil {
return err
}
v.Estack().PushVal(header.Version)
return nil
}
// headerGetMerkleRoot returns version from the header.
func headerGetMerkleRoot(ic *interop.Context, v *vm.VM) error {
header, err := popHeaderFromVM(v)
if err != nil {
return err
}
v.Estack().PushVal(header.MerkleRoot.BytesBE())
return nil
}
// headerGetNextConsensus returns version from the header.
func headerGetNextConsensus(ic *interop.Context, v *vm.VM) error {
header, err := popHeaderFromVM(v)
if err != nil {
return err
}
v.Estack().PushVal(header.NextConsensus.BytesBE())
return nil
}
// txGetAttributes returns current transaction attributes.
func txGetAttributes(ic *interop.Context, v *vm.VM) error {
txInterface := v.Estack().Pop().Value()
tx, ok := txInterface.(*transaction.Transaction)
if !ok {
return errors.New("value is not a transaction")
}
if len(tx.Attributes) > vm.MaxArraySize {
return errors.New("too many attributes")
}
attrs := make([]stackitem.Item, 0, len(tx.Attributes))
for i := range tx.Attributes {
attrs = append(attrs, stackitem.NewInterop(&tx.Attributes[i]))
}
v.Estack().PushVal(attrs)
return nil
}
// txGetWitnesses returns current transaction witnesses.
func txGetWitnesses(ic *interop.Context, v *vm.VM) error {
txInterface := v.Estack().Pop().Value()
tx, ok := txInterface.(*transaction.Transaction)
if !ok {
return errors.New("value is not a transaction")
}
if len(tx.Scripts) > vm.MaxArraySize {
return errors.New("too many outputs")
}
scripts := make([]stackitem.Item, 0, len(tx.Scripts))
for i := range tx.Scripts {
scripts = append(scripts, stackitem.NewInterop(&tx.Scripts[i]))
}
v.Estack().PushVal(scripts)
return nil
}
// witnessGetVerificationScript returns current witness' script.
func witnessGetVerificationScript(ic *interop.Context, v *vm.VM) error {
witInterface := v.Estack().Pop().Value()
wit, ok := witInterface.(*transaction.Witness)
if !ok {
return errors.New("value is not a witness")
}
// It's important not to share wit.VerificationScript slice with the code running in VM.
script := make([]byte, len(wit.VerificationScript))
copy(script, wit.VerificationScript)
v.Estack().PushVal(script)
return nil
}
// attrGetData returns tx attribute data.
func attrGetData(ic *interop.Context, v *vm.VM) error {
attrInterface := v.Estack().Pop().Value()
attr, ok := attrInterface.(*transaction.Attribute)
if !ok {
return fmt.Errorf("%T is not an attribute", attr)
}
v.Estack().PushVal(attr.Data)
return nil
}
// attrGetData returns tx attribute usage field.
func attrGetUsage(ic *interop.Context, v *vm.VM) error {
attrInterface := v.Estack().Pop().Value()
attr, ok := attrInterface.(*transaction.Attribute)
if !ok {
return fmt.Errorf("%T is not an attribute", attr)
}
v.Estack().PushVal(int(attr.Usage))
return nil
}
// bcGetAccount returns or creates an account.
func bcGetAccount(ic *interop.Context, v *vm.VM) error {
accbytes := v.Estack().Pop().Bytes()
acchash, err := util.Uint160DecodeBytesBE(accbytes)
if err != nil {
return err
}
acc, err := ic.DAO.GetAccountStateOrNew(acchash)
if err != nil {
return err
}
v.Estack().PushVal(stackitem.NewInterop(acc))
return nil
}
// accountGetBalance returns balance for a given account.
func accountGetBalance(ic *interop.Context, v *vm.VM) error {
accInterface := v.Estack().Pop().Value()
acc, ok := accInterface.(*state.Account)
if !ok {
return fmt.Errorf("%T is not an account state", acc)
}
asbytes := v.Estack().Pop().Bytes()
ashash, err := util.Uint256DecodeBytesBE(asbytes)
if err != nil {
return err
}
balance, ok := acc.GetBalanceValues()[ashash]
if !ok {
balance = util.Fixed8(0)
}
v.Estack().PushVal(int64(balance))
return nil
}
// accountGetScriptHash returns script hash of a given account.
func accountGetScriptHash(ic *interop.Context, v *vm.VM) error {
accInterface := v.Estack().Pop().Value()
acc, ok := accInterface.(*state.Account)
if !ok {
return fmt.Errorf("%T is not an account state", acc)
}
v.Estack().PushVal(acc.ScriptHash.BytesBE())
return nil
}
// accountIsStandard checks whether given account is standard.
func accountIsStandard(ic *interop.Context, v *vm.VM) error {
accbytes := v.Estack().Pop().Bytes()
acchash, err := util.Uint160DecodeBytesBE(accbytes)
if err != nil {
return err
}
contract, err := ic.DAO.GetContractState(acchash)
res := err != nil || vm.IsStandardContract(contract.Script)
v.Estack().PushVal(res)
return nil
}
// storageFind finds stored key-value pair.
func storageFind(ic *interop.Context, v *vm.VM) error {
stcInterface := v.Estack().Pop().Value()
stc, ok := stcInterface.(*StorageContext)
if !ok {
return fmt.Errorf("%T is not a StorageContext", stcInterface)
}
err := checkStorageContext(ic, stc)
if err != nil {
return err
}
prefix := v.Estack().Pop().Bytes()
siMap, err := ic.DAO.GetStorageItemsWithPrefix(stc.ScriptHash, prefix)
if err != nil {
return err
}
filteredMap := stackitem.NewMap()
for k, v := range siMap {
filteredMap.Add(stackitem.NewByteArray(append(prefix, []byte(k)...)), stackitem.NewByteArray(v.Value))
}
sort.Slice(filteredMap.Value().([]stackitem.MapElement), func(i, j int) bool {
return bytes.Compare(filteredMap.Value().([]stackitem.MapElement)[i].Key.Value().([]byte),
filteredMap.Value().([]stackitem.MapElement)[j].Key.Value().([]byte)) == -1
})
item := vm.NewMapIterator(filteredMap)
v.Estack().PushVal(item)
return nil
}
// createContractStateFromVM pops all contract state elements from the VM
// evaluation stack, does a lot of checks and returns Contract if it
// succeeds.
func createContractStateFromVM(ic *interop.Context, v *vm.VM) (*state.Contract, error) {
if ic.Trigger != trigger.Application {
return nil, errors.New("can't create contract when not triggered by an application")
}
script := v.Estack().Pop().Bytes()
if len(script) > MaxContractScriptSize {
return nil, errors.New("the script is too big")
}
paramBytes := v.Estack().Pop().Bytes()
if len(paramBytes) > MaxContractParametersNum {
return nil, errors.New("too many parameters for a script")
}
paramList := make([]smartcontract.ParamType, len(paramBytes))
for k, v := range paramBytes {
paramList[k] = smartcontract.ParamType(v)
}
retType := smartcontract.ParamType(v.Estack().Pop().BigInt().Int64())
properties := smartcontract.PropertyState(v.Estack().Pop().BigInt().Int64())
name := v.Estack().Pop().Bytes()
if len(name) > MaxContractStringLen {
return nil, errors.New("too big name")
}
version := v.Estack().Pop().Bytes()
if len(version) > MaxContractStringLen {
return nil, errors.New("too big version")
}
author := v.Estack().Pop().Bytes()
if len(author) > MaxContractStringLen {
return nil, errors.New("too big author")
}
email := v.Estack().Pop().Bytes()
if len(email) > MaxContractStringLen {
return nil, errors.New("too big email")
}
desc := v.Estack().Pop().Bytes()
if len(desc) > MaxContractDescriptionLen {
return nil, errors.New("too big description")
}
contract := &state.Contract{
Script: script,
ParamList: paramList,
ReturnType: retType,
Properties: properties,
Name: string(name),
CodeVersion: string(version),
Author: string(author),
Email: string(email),
Description: string(desc),
}
return contract, nil
}
// contractCreate creates a contract.
func contractCreate(ic *interop.Context, v *vm.VM) error {
newcontract, err := createContractStateFromVM(ic, v)
if err != nil {
return err
}
contract, err := ic.DAO.GetContractState(newcontract.ScriptHash())
if err != nil {
contract = newcontract
err := ic.DAO.PutContractState(contract)
if err != nil {
return err
}
}
v.Estack().PushVal(stackitem.NewInterop(contract))
return nil
}
// contractGetScript returns a script associated with a contract.
func contractGetScript(ic *interop.Context, v *vm.VM) error {
csInterface := v.Estack().Pop().Value()
cs, ok := csInterface.(*state.Contract)
if !ok {
return fmt.Errorf("%T is not a contract state", cs)
}
v.Estack().PushVal(cs.Script)
return nil
}
// contractIsPayable returns whether contract is payable.
func contractIsPayable(ic *interop.Context, v *vm.VM) error {
csInterface := v.Estack().Pop().Value()
cs, ok := csInterface.(*state.Contract)
if !ok {
return fmt.Errorf("%T is not a contract state", cs)
}
v.Estack().PushVal(cs.IsPayable())
return nil
}
// contractMigrate migrates a contract.
func contractMigrate(ic *interop.Context, v *vm.VM) error {
newcontract, err := createContractStateFromVM(ic, v)
if err != nil {
return err
}
contract, err := ic.DAO.GetContractState(newcontract.ScriptHash())
if err != nil {
contract = newcontract
err := ic.DAO.PutContractState(contract)
if err != nil {
return err
}
if contract.HasStorage() {
hash := v.GetCurrentScriptHash()
siMap, err := ic.DAO.GetStorageItems(hash)
if err != nil {
return err
}
for k, v := range siMap {
v.IsConst = false
err = ic.DAO.PutStorageItem(contract.ScriptHash(), []byte(k), v)
if err != nil {
return err
}
}
}
}
v.Estack().PushVal(stackitem.NewInterop(contract))
return contractDestroy(ic, v)
}
// runtimeSerialize serializes top stack item into a ByteArray.
func runtimeSerialize(_ *interop.Context, v *vm.VM) error {
return vm.RuntimeSerialize(v)
}
// runtimeDeserialize deserializes ByteArray from a stack into an item.
func runtimeDeserialize(_ *interop.Context, v *vm.VM) error {
return vm.RuntimeDeserialize(v)
}