neoneo-go/pkg/core/native/policy.go

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package native
import (
"encoding/binary"
"errors"
"fmt"
"math/big"
"sort"
"sync"
"github.com/nspcc-dev/neo-go/pkg/core/dao"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/core/interop/runtime"
"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/network/payload"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
const (
policyName = "Policy"
policyContractID = -3
defaultMaxBlockSize = 1024 * 256
defaultMaxTransactionsPerBlock = 512
defaultFeePerByte = 1000
defaultMaxVerificationGas = 50000000
defaultMaxBlockSystemFee = 9000 * GASFactor
// minBlockSystemFee is the minimum allowed system fee per block.
minBlockSystemFee = 4007600
)
var (
// maxTransactionsPerBlockKey is a key used to store the maximum number of
// transactions allowed in block.
maxTransactionsPerBlockKey = []byte{23}
// feePerByteKey is a key used to store the minimum fee per byte for
// transaction.
feePerByteKey = []byte{10}
// blockedAccountsKey is a key used to store the list of blocked accounts.
blockedAccountsKey = []byte{15}
// maxBlockSizeKey is a key used to store the maximum block size value.
maxBlockSizeKey = []byte{12}
// maxBlockSystemFeeKey is a key used to store the maximum block system fee value.
maxBlockSystemFeeKey = []byte{17}
)
// Policy represents Policy native contract.
type Policy struct {
interop.ContractMD
lock sync.RWMutex
// isValid defies whether cached values were changed during the current
// consensus iteration. If false, these values will be updated after
// blockchain DAO persisting. If true, we can safely use cached values.
isValid bool
maxTransactionsPerBlock uint32
maxBlockSize uint32
feePerByte int64
maxBlockSystemFee int64
maxVerificationGas int64
}
var _ interop.Contract = (*Policy)(nil)
// newPolicy returns Policy native contract.
func newPolicy() *Policy {
p := &Policy{ContractMD: *interop.NewContractMD(policyName)}
p.ContractID = policyContractID
p.Manifest.Features |= smartcontract.HasStorage
desc := newDescriptor("getMaxTransactionsPerBlock", smartcontract.IntegerType)
md := newMethodAndPrice(p.getMaxTransactionsPerBlock, 1000000, smartcontract.AllowStates)
p.AddMethod(md, desc, true)
desc = newDescriptor("getMaxBlockSize", smartcontract.IntegerType)
md = newMethodAndPrice(p.getMaxBlockSize, 1000000, smartcontract.AllowStates)
p.AddMethod(md, desc, true)
desc = newDescriptor("getFeePerByte", smartcontract.IntegerType)
md = newMethodAndPrice(p.getFeePerByte, 1000000, smartcontract.AllowStates)
p.AddMethod(md, desc, true)
desc = newDescriptor("getBlockedAccounts", smartcontract.ArrayType)
md = newMethodAndPrice(p.getBlockedAccounts, 1000000, smartcontract.AllowStates)
p.AddMethod(md, desc, true)
desc = newDescriptor("getMaxBlockSystemFee", smartcontract.IntegerType)
md = newMethodAndPrice(p.getMaxBlockSystemFee, 1000000, smartcontract.AllowStates)
p.AddMethod(md, desc, true)
desc = newDescriptor("setMaxBlockSize", smartcontract.BoolType,
manifest.NewParameter("value", smartcontract.IntegerType))
md = newMethodAndPrice(p.setMaxBlockSize, 3000000, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
desc = newDescriptor("setMaxTransactionsPerBlock", smartcontract.BoolType,
manifest.NewParameter("value", smartcontract.IntegerType))
md = newMethodAndPrice(p.setMaxTransactionsPerBlock, 3000000, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
desc = newDescriptor("setFeePerByte", smartcontract.BoolType,
manifest.NewParameter("value", smartcontract.IntegerType))
md = newMethodAndPrice(p.setFeePerByte, 3000000, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
desc = newDescriptor("setMaxBlockSystemFee", smartcontract.BoolType,
manifest.NewParameter("value", smartcontract.IntegerType))
md = newMethodAndPrice(p.setMaxBlockSystemFee, 3000000, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
desc = newDescriptor("blockAccount", smartcontract.BoolType,
manifest.NewParameter("account", smartcontract.Hash160Type))
md = newMethodAndPrice(p.blockAccount, 3000000, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
desc = newDescriptor("unblockAccount", smartcontract.BoolType,
manifest.NewParameter("account", smartcontract.Hash160Type))
md = newMethodAndPrice(p.unblockAccount, 3000000, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
desc = newDescriptor("onPersist", smartcontract.VoidType)
md = newMethodAndPrice(getOnPersistWrapper(p.OnPersist), 0, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
desc = newDescriptor("postPersist", smartcontract.VoidType)
md = newMethodAndPrice(getOnPersistWrapper(postPersistBase), 0, smartcontract.AllowModifyStates)
p.AddMethod(md, desc, false)
return p
}
// Metadata implements Contract interface.
func (p *Policy) Metadata() *interop.ContractMD {
return &p.ContractMD
}
// Initialize initializes Policy native contract and implements Contract interface.
func (p *Policy) Initialize(ic *interop.Context) error {
si := &state.StorageItem{
Value: make([]byte, 4, 8),
}
binary.LittleEndian.PutUint32(si.Value, defaultMaxBlockSize)
err := ic.DAO.PutStorageItem(p.ContractID, maxBlockSizeKey, si)
if err != nil {
return err
}
binary.LittleEndian.PutUint32(si.Value, defaultMaxTransactionsPerBlock)
err = ic.DAO.PutStorageItem(p.ContractID, maxTransactionsPerBlockKey, si)
if err != nil {
return err
}
si.Value = si.Value[:8]
binary.LittleEndian.PutUint64(si.Value, defaultFeePerByte)
err = ic.DAO.PutStorageItem(p.ContractID, feePerByteKey, si)
if err != nil {
return err
}
binary.LittleEndian.PutUint64(si.Value, defaultMaxBlockSystemFee)
err = ic.DAO.PutStorageItem(p.ContractID, maxBlockSystemFeeKey, si)
if err != nil {
return err
}
ba := new(BlockedAccounts)
si.Value = ba.Bytes()
err = ic.DAO.PutStorageItem(p.ContractID, blockedAccountsKey, si)
if err != nil {
return err
}
p.isValid = true
p.maxTransactionsPerBlock = defaultMaxTransactionsPerBlock
p.maxBlockSize = defaultMaxBlockSize
p.feePerByte = defaultFeePerByte
p.maxBlockSystemFee = defaultMaxBlockSystemFee
p.maxVerificationGas = defaultMaxVerificationGas
return nil
}
// OnPersist implements Contract interface.
func (p *Policy) OnPersist(ic *interop.Context) error {
return nil
}
// OnPersistEnd updates cached Policy values if they've been changed
func (p *Policy) OnPersistEnd(dao dao.DAO) {
if p.isValid {
return
}
p.lock.Lock()
defer p.lock.Unlock()
maxTxPerBlock := p.getUint32WithKey(dao, maxTransactionsPerBlockKey)
p.maxTransactionsPerBlock = maxTxPerBlock
maxBlockSize := p.getUint32WithKey(dao, maxBlockSizeKey)
p.maxBlockSize = maxBlockSize
feePerByte := p.getInt64WithKey(dao, feePerByteKey)
p.feePerByte = feePerByte
maxBlockSystemFee := p.getInt64WithKey(dao, maxBlockSystemFeeKey)
p.maxBlockSystemFee = maxBlockSystemFee
core: fix bug with policy.MaxVerificationGas In 121c9664b we should take into account isValid flag of NativePolicy contract while retrieving MaxVerificationGas native policy value. Otherwise we won't be able to get MaxVerificationGas after the node was restarted, because this value is not truly stored along with the other native policy values. This commit fixes bug with headers verification after the node restarting with an existing storage: ``` 2020-08-03T12:52:56.158+0300 WARN failed processing headers {"error": "vm failed to execute the script with error: error encountered at instruction 0 (PUSHDATA1): gas limit is exceeded", "errorVerbose": "vm failed to execute the script with error: error encountered at instruction 0 (PUSHDATA1): gas limit is exceeded\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).verifyHashAgainstScript\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:1454\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).verifyHeaderWitnesses\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:1517\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).verifyHeader\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:1175\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).addHeaders\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:484\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).AddHeaders\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:453\ngithub.com/nspcc-dev/neo-go/pkg/network.(*Server).handleHeadersCmd\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/network/server.go:454\nruntime.goexit\n\t/usr/local/go/src/runtime/asm_amd64.s:1373"} ```
2020-08-03 10:30:51 +00:00
p.maxVerificationGas = defaultMaxVerificationGas
p.isValid = true
}
// getMaxTransactionsPerBlock is Policy contract method and returns the upper
// limit of transactions per block.
func (p *Policy) getMaxTransactionsPerBlock(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.NewBigInteger(big.NewInt(int64(p.GetMaxTransactionsPerBlockInternal(ic.DAO))))
}
// GetMaxTransactionsPerBlockInternal returns the upper limit of transactions per
// block.
func (p *Policy) GetMaxTransactionsPerBlockInternal(dao dao.DAO) uint32 {
p.lock.RLock()
defer p.lock.RUnlock()
if p.isValid {
return p.maxTransactionsPerBlock
}
return p.getUint32WithKey(dao, maxTransactionsPerBlockKey)
}
// getMaxBlockSize is Policy contract method and returns maximum block size.
func (p *Policy) getMaxBlockSize(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.NewBigInteger(big.NewInt(int64(p.GetMaxBlockSizeInternal(ic.DAO))))
}
// GetMaxBlockSizeInternal returns maximum block size.
func (p *Policy) GetMaxBlockSizeInternal(dao dao.DAO) uint32 {
p.lock.RLock()
defer p.lock.RUnlock()
if p.isValid {
return p.maxBlockSize
}
return p.getUint32WithKey(dao, maxBlockSizeKey)
}
// getFeePerByte is Policy contract method and returns required transaction's fee
// per byte.
func (p *Policy) getFeePerByte(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.NewBigInteger(big.NewInt(p.GetFeePerByteInternal(ic.DAO)))
}
// GetFeePerByteInternal returns required transaction's fee per byte.
func (p *Policy) GetFeePerByteInternal(dao dao.DAO) int64 {
p.lock.RLock()
defer p.lock.RUnlock()
if p.isValid {
return p.feePerByte
}
return p.getInt64WithKey(dao, feePerByteKey)
}
// GetMaxVerificationGas returns maximum gas allowed to be burned during verificaion.
func (p *Policy) GetMaxVerificationGas(_ dao.DAO) int64 {
core: fix bug with policy.MaxVerificationGas In 121c9664b we should take into account isValid flag of NativePolicy contract while retrieving MaxVerificationGas native policy value. Otherwise we won't be able to get MaxVerificationGas after the node was restarted, because this value is not truly stored along with the other native policy values. This commit fixes bug with headers verification after the node restarting with an existing storage: ``` 2020-08-03T12:52:56.158+0300 WARN failed processing headers {"error": "vm failed to execute the script with error: error encountered at instruction 0 (PUSHDATA1): gas limit is exceeded", "errorVerbose": "vm failed to execute the script with error: error encountered at instruction 0 (PUSHDATA1): gas limit is exceeded\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).verifyHashAgainstScript\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:1454\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).verifyHeaderWitnesses\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:1517\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).verifyHeader\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:1175\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).addHeaders\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:484\ngithub.com/nspcc-dev/neo-go/pkg/core.(*Blockchain).AddHeaders\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/core/blockchain.go:453\ngithub.com/nspcc-dev/neo-go/pkg/network.(*Server).handleHeadersCmd\n\t/home/neospcc/Documents/GitProjects/nspcc-dev/neo-go/pkg/network/server.go:454\nruntime.goexit\n\t/usr/local/go/src/runtime/asm_amd64.s:1373"} ```
2020-08-03 10:30:51 +00:00
if p.isValid {
return p.maxVerificationGas
}
return defaultMaxVerificationGas
}
// getMaxBlockSystemFee is Policy contract method and returns the maximum overall
// system fee per block.
func (p *Policy) getMaxBlockSystemFee(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.NewBigInteger(big.NewInt(p.GetMaxBlockSystemFeeInternal(ic.DAO)))
}
// GetMaxBlockSystemFeeInternal the maximum overall system fee per block.
func (p *Policy) GetMaxBlockSystemFeeInternal(dao dao.DAO) int64 {
p.lock.RLock()
defer p.lock.RUnlock()
if p.isValid {
return p.maxBlockSystemFee
}
return p.getInt64WithKey(dao, maxBlockSystemFeeKey)
}
// getBlockedAccounts is Policy contract method and returns list of blocked
// accounts hashes.
func (p *Policy) getBlockedAccounts(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
ba, err := p.GetBlockedAccountsInternal(ic.DAO)
if err != nil {
panic(err)
}
return ba.ToStackItem()
}
// GetBlockedAccountsInternal returns list of blocked accounts hashes.
func (p *Policy) GetBlockedAccountsInternal(dao dao.DAO) (BlockedAccounts, error) {
si := dao.GetStorageItem(p.ContractID, blockedAccountsKey)
if si == nil {
return nil, errors.New("BlockedAccounts uninitialized")
}
ba, err := BlockedAccountsFromBytes(si.Value)
if err != nil {
return nil, err
}
return ba, nil
}
// setMaxTransactionsPerBlock is Policy contract method and sets the upper limit
// of transactions per block.
func (p *Policy) setMaxTransactionsPerBlock(ic *interop.Context, args []stackitem.Item) stackitem.Item {
ok, err := p.checkValidators(ic)
if err != nil {
panic(err)
}
if !ok {
return stackitem.NewBool(false)
}
value := uint32(toBigInt(args[0]).Int64())
p.lock.Lock()
defer p.lock.Unlock()
err = p.setUint32WithKey(ic.DAO, maxTransactionsPerBlockKey, value)
if err != nil {
panic(err)
}
p.isValid = false
return stackitem.NewBool(true)
}
// setMaxBlockSize is Policy contract method and sets maximum block size.
func (p *Policy) setMaxBlockSize(ic *interop.Context, args []stackitem.Item) stackitem.Item {
ok, err := p.checkValidators(ic)
if err != nil {
panic(err)
}
if !ok {
return stackitem.NewBool(false)
}
value := uint32(toBigInt(args[0]).Int64())
if payload.MaxSize <= value {
return stackitem.NewBool(false)
}
p.lock.Lock()
defer p.lock.Unlock()
err = p.setUint32WithKey(ic.DAO, maxBlockSizeKey, value)
if err != nil {
panic(err)
}
p.isValid = false
return stackitem.NewBool(true)
}
// setFeePerByte is Policy contract method and sets transaction's fee per byte.
func (p *Policy) setFeePerByte(ic *interop.Context, args []stackitem.Item) stackitem.Item {
ok, err := p.checkValidators(ic)
if err != nil {
panic(err)
}
if !ok {
return stackitem.NewBool(false)
}
value := toBigInt(args[0]).Int64()
p.lock.Lock()
defer p.lock.Unlock()
err = p.setInt64WithKey(ic.DAO, feePerByteKey, value)
if err != nil {
panic(err)
}
p.isValid = false
return stackitem.NewBool(true)
}
// setMaxBlockSystemFee is Policy contract method and sets the maximum system fee per block.
func (p *Policy) setMaxBlockSystemFee(ic *interop.Context, args []stackitem.Item) stackitem.Item {
ok, err := p.checkValidators(ic)
if err != nil {
panic(err)
}
if !ok {
return stackitem.NewBool(false)
}
value := toBigInt(args[0]).Int64()
if value <= minBlockSystemFee {
return stackitem.NewBool(false)
}
p.lock.Lock()
defer p.lock.Unlock()
err = p.setInt64WithKey(ic.DAO, maxBlockSystemFeeKey, value)
if err != nil {
panic(err)
}
p.isValid = false
return stackitem.NewBool(true)
}
// blockAccount is Policy contract method and adds given account hash to the list
// of blocked accounts.
func (p *Policy) blockAccount(ic *interop.Context, args []stackitem.Item) stackitem.Item {
ok, err := p.checkValidators(ic)
if err != nil {
panic(err)
}
if !ok {
return stackitem.NewBool(false)
}
value := toUint160(args[0])
si := ic.DAO.GetStorageItem(p.ContractID, blockedAccountsKey)
if si == nil {
panic("BlockedAccounts uninitialized")
}
ba, err := BlockedAccountsFromBytes(si.Value)
if err != nil {
panic(err)
}
indexToInsert := sort.Search(len(ba), func(i int) bool {
return !ba[i].Less(value)
})
ba = append(ba, value)
if indexToInsert != len(ba)-1 && ba[indexToInsert].Equals(value) {
return stackitem.NewBool(false)
}
if len(ba) > 1 {
copy(ba[indexToInsert+1:], ba[indexToInsert:])
ba[indexToInsert] = value
}
err = ic.DAO.PutStorageItem(p.ContractID, blockedAccountsKey, &state.StorageItem{
Value: ba.Bytes(),
})
if err != nil {
panic(err)
}
return stackitem.NewBool(true)
}
// unblockAccount is Policy contract method and removes given account hash from
// the list of blocked accounts.
func (p *Policy) unblockAccount(ic *interop.Context, args []stackitem.Item) stackitem.Item {
ok, err := p.checkValidators(ic)
if err != nil {
panic(err)
}
if !ok {
return stackitem.NewBool(false)
}
value := toUint160(args[0])
si := ic.DAO.GetStorageItem(p.ContractID, blockedAccountsKey)
if si == nil {
panic("BlockedAccounts uninitialized")
}
ba, err := BlockedAccountsFromBytes(si.Value)
if err != nil {
panic(err)
}
indexToRemove := sort.Search(len(ba), func(i int) bool {
return !ba[i].Less(value)
})
if indexToRemove == len(ba) || !ba[indexToRemove].Equals(value) {
return stackitem.NewBool(false)
}
ba = append(ba[:indexToRemove], ba[indexToRemove+1:]...)
err = ic.DAO.PutStorageItem(p.ContractID, blockedAccountsKey, &state.StorageItem{
Value: ba.Bytes(),
})
if err != nil {
panic(err)
}
return stackitem.NewBool(true)
}
func (p *Policy) getUint32WithKey(dao dao.DAO, key []byte) uint32 {
si := dao.GetStorageItem(p.ContractID, key)
if si == nil {
return 0
}
return binary.LittleEndian.Uint32(si.Value)
}
func (p *Policy) setUint32WithKey(dao dao.DAO, key []byte, value uint32) error {
si := dao.GetStorageItem(p.ContractID, key)
binary.LittleEndian.PutUint32(si.Value, value)
err := dao.PutStorageItem(p.ContractID, key, si)
if err != nil {
return err
}
return nil
}
func (p *Policy) getInt64WithKey(dao dao.DAO, key []byte) int64 {
si := dao.GetStorageItem(p.ContractID, key)
if si == nil {
return 0
}
return int64(binary.LittleEndian.Uint64(si.Value))
}
func (p *Policy) setInt64WithKey(dao dao.DAO, key []byte, value int64) error {
si := dao.GetStorageItem(p.ContractID, key)
binary.LittleEndian.PutUint64(si.Value, uint64(value))
err := dao.PutStorageItem(p.ContractID, key, si)
if err != nil {
return err
}
return nil
}
func (p *Policy) checkValidators(ic *interop.Context) (bool, error) {
prevBlock, err := ic.Chain.GetBlock(ic.Block.PrevHash)
if err != nil {
return false, err
}
return runtime.CheckHashedWitness(ic, prevBlock.NextConsensus)
}
// CheckPolicy checks whether transaction conforms to current policy restrictions
// like not being signed by blocked account or not exceeding block-level system
// fee limit.
func (p *Policy) CheckPolicy(d dao.DAO, tx *transaction.Transaction) error {
ba, err := p.GetBlockedAccountsInternal(d)
if err != nil {
return fmt.Errorf("unable to get blocked accounts list: %w", err)
}
if len(ba) > 0 {
for _, signer := range tx.Signers {
i := sort.Search(len(ba), func(i int) bool {
return !ba[i].Less(signer.Account)
})
if i != len(ba) && ba[i].Equals(signer.Account) {
return fmt.Errorf("account %s is blocked", signer.Account.StringLE())
}
}
}
maxBlockSystemFee := p.GetMaxBlockSystemFeeInternal(d)
if maxBlockSystemFee < tx.SystemFee {
return fmt.Errorf("transaction's fee can't exceed maximum block system fee %d", maxBlockSystemFee)
}
return nil
}