neo-go/pkg/core/native/oracle.go
Anna Shaleva 33c971b0e4 core: add InitializeCache method to Contract interface
Make the contracts cache initialization unified. The order of cache
iniitialization is not important and Nottary contract is added to the
bc.contracts.Contracts wrt P2PSigExtensions setting, thus no functional
changes, just refactoring for future applications.

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
2023-04-26 12:57:48 +03:00

571 lines
16 KiB
Go

package native
import (
"encoding/binary"
"errors"
"fmt"
"math"
"math/big"
"strings"
"sync/atomic"
"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/contract"
"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
"github.com/nspcc-dev/neo-go/pkg/core/native/noderoles"
"github.com/nspcc-dev/neo-go/pkg/core/state"
"github.com/nspcc-dev/neo-go/pkg/core/storage"
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/util/slice"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
// Oracle represents Oracle native contract.
type Oracle struct {
interop.ContractMD
GAS *GAS
NEO *NEO
Desig *Designate
oracleScript []byte
// Module is an oracle module capable of talking with the external world.
Module atomic.Value
// newRequests contains new requests created during the current block.
newRequests map[uint64]*state.OracleRequest
}
type OracleCache struct {
requestPrice int64
}
// OracleService specifies oracle module interface.
type OracleService interface {
// AddRequests processes new requests.
AddRequests(map[uint64]*state.OracleRequest)
// RemoveRequests removes already processed requests.
RemoveRequests([]uint64)
// UpdateOracleNodes updates oracle nodes.
UpdateOracleNodes(keys.PublicKeys)
// UpdateNativeContract updates oracle contract native script and hash.
UpdateNativeContract([]byte, []byte, util.Uint160, int)
// Start runs oracle module.
Start()
// Shutdown shutdowns oracle module.
Shutdown()
}
const (
oracleContractID = -9
maxURLLength = 256
maxFilterLength = 128
maxCallbackLength = 32
maxUserDataLength = 512
// maxRequestsCount is the maximum number of requests per URL.
maxRequestsCount = 256
// DefaultOracleRequestPrice is the default amount GAS needed for an oracle request.
DefaultOracleRequestPrice = 5000_0000
// MinimumResponseGas is the minimum response fee permitted for a request.
MinimumResponseGas = 10_000_000
)
var (
prefixRequestPrice = []byte{5}
prefixIDList = []byte{6}
prefixRequest = []byte{7}
prefixRequestID = []byte{9}
)
// Various validation errors.
var (
ErrBigArgument = errors.New("some of the arguments are invalid")
ErrInvalidWitness = errors.New("witness check failed")
ErrLowResponseGas = errors.New("not enough gas for response")
ErrNotEnoughGas = errors.New("gas limit exceeded")
ErrRequestNotFound = errors.New("oracle request not found")
ErrResponseNotFound = errors.New("oracle response not found")
)
var (
_ interop.Contract = (*Oracle)(nil)
_ dao.NativeContractCache = (*OracleCache)(nil)
)
// Copy implements NativeContractCache interface.
func (c *OracleCache) Copy() dao.NativeContractCache {
cp := &OracleCache{}
copyOracleCache(c, cp)
return cp
}
func copyOracleCache(src, dst *OracleCache) {
*dst = *src
}
func newOracle() *Oracle {
o := &Oracle{
ContractMD: *interop.NewContractMD(nativenames.Oracle, oracleContractID),
newRequests: make(map[uint64]*state.OracleRequest),
}
defer o.UpdateHash()
o.oracleScript = CreateOracleResponseScript(o.Hash)
desc := newDescriptor("request", smartcontract.VoidType,
manifest.NewParameter("url", smartcontract.StringType),
manifest.NewParameter("filter", smartcontract.StringType),
manifest.NewParameter("callback", smartcontract.StringType),
manifest.NewParameter("userData", smartcontract.AnyType),
manifest.NewParameter("gasForResponse", smartcontract.IntegerType))
md := newMethodAndPrice(o.request, 0, callflag.States|callflag.AllowNotify)
o.AddMethod(md, desc)
desc = newDescriptor("finish", smartcontract.VoidType)
md = newMethodAndPrice(o.finish, 0, callflag.States|callflag.AllowCall|callflag.AllowNotify)
o.AddMethod(md, desc)
desc = newDescriptor("verify", smartcontract.BoolType)
md = newMethodAndPrice(o.verify, 1<<15, callflag.NoneFlag)
o.AddMethod(md, desc)
o.AddEvent("OracleRequest", manifest.NewParameter("Id", smartcontract.IntegerType),
manifest.NewParameter("RequestContract", smartcontract.Hash160Type),
manifest.NewParameter("Url", smartcontract.StringType),
manifest.NewParameter("Filter", smartcontract.StringType))
o.AddEvent("OracleResponse", manifest.NewParameter("Id", smartcontract.IntegerType),
manifest.NewParameter("OriginalTx", smartcontract.Hash256Type))
desc = newDescriptor("getPrice", smartcontract.IntegerType)
md = newMethodAndPrice(o.getPrice, 1<<15, callflag.ReadStates)
o.AddMethod(md, desc)
desc = newDescriptor("setPrice", smartcontract.VoidType,
manifest.NewParameter("price", smartcontract.IntegerType))
md = newMethodAndPrice(o.setPrice, 1<<15, callflag.States)
o.AddMethod(md, desc)
return o
}
// GetOracleResponseScript returns a script for the transaction with an oracle response.
func (o *Oracle) GetOracleResponseScript() []byte {
return slice.Copy(o.oracleScript)
}
// OnPersist implements the Contract interface.
func (o *Oracle) OnPersist(ic *interop.Context) error {
return nil
}
// PostPersist represents `postPersist` method.
func (o *Oracle) PostPersist(ic *interop.Context) error {
p := o.getPriceInternal(ic.DAO)
var nodes keys.PublicKeys
var reward []big.Int
single := big.NewInt(p)
var removedIDs []uint64
orc, _ := o.Module.Load().(*OracleService)
for _, tx := range ic.Block.Transactions {
resp := getResponse(tx)
if resp == nil {
continue
}
reqKey := makeRequestKey(resp.ID)
req := new(state.OracleRequest)
if err := o.getConvertibleFromDAO(ic.DAO, reqKey, req); err != nil {
continue
}
ic.DAO.DeleteStorageItem(o.ID, reqKey)
if orc != nil && *orc != nil {
removedIDs = append(removedIDs, resp.ID)
}
idKey := makeIDListKey(req.URL)
idList := new(IDList)
if err := o.getConvertibleFromDAO(ic.DAO, idKey, idList); err != nil {
return err
}
if !idList.Remove(resp.ID) {
return errors.New("response ID wasn't found")
}
var err error
if len(*idList) == 0 {
ic.DAO.DeleteStorageItem(o.ID, idKey)
} else {
err = putConvertibleToDAO(o.ID, ic.DAO, idKey, idList)
}
if err != nil {
return err
}
if nodes == nil {
nodes, err = o.GetOracleNodes(ic.DAO)
if err != nil {
return err
}
reward = make([]big.Int, len(nodes))
}
if len(reward) > 0 {
index := resp.ID % uint64(len(nodes))
reward[index].Add(&reward[index], single)
}
}
for i := range reward {
o.GAS.mint(ic, nodes[i].GetScriptHash(), &reward[i], false)
}
if len(removedIDs) != 0 {
(*orc).RemoveRequests(removedIDs)
}
return o.updateCache(ic.DAO)
}
// Metadata returns contract metadata.
func (o *Oracle) Metadata() *interop.ContractMD {
return &o.ContractMD
}
// Initialize initializes an Oracle contract.
func (o *Oracle) Initialize(ic *interop.Context) error {
setIntWithKey(o.ID, ic.DAO, prefixRequestID, 0)
setIntWithKey(o.ID, ic.DAO, prefixRequestPrice, DefaultOracleRequestPrice)
cache := &OracleCache{
requestPrice: int64(DefaultOracleRequestPrice),
}
ic.DAO.SetCache(o.ID, cache)
return nil
}
func (o *Oracle) InitializeCache(blockHeight uint32, d *dao.Simple) error {
cache := &OracleCache{}
cache.requestPrice = getIntWithKey(o.ID, d, prefixRequestPrice)
d.SetCache(o.ID, cache)
return nil
}
func getResponse(tx *transaction.Transaction) *transaction.OracleResponse {
for i := range tx.Attributes {
if tx.Attributes[i].Type == transaction.OracleResponseT {
return tx.Attributes[i].Value.(*transaction.OracleResponse)
}
}
return nil
}
func (o *Oracle) finish(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
err := o.FinishInternal(ic)
if err != nil {
panic(err)
}
return stackitem.Null{}
}
// FinishInternal processes an oracle response.
func (o *Oracle) FinishInternal(ic *interop.Context) error {
if len(ic.VM.Istack()) != 2 {
return errors.New("Oracle.finish called from non-entry script")
}
if ic.Invocations[o.Hash] != 1 {
return errors.New("Oracle.finish called multiple times")
}
resp := getResponse(ic.Tx)
if resp == nil {
return ErrResponseNotFound
}
req, err := o.GetRequestInternal(ic.DAO, resp.ID)
if err != nil {
return ErrRequestNotFound
}
ic.AddNotification(o.Hash, "OracleResponse", stackitem.NewArray([]stackitem.Item{
stackitem.Make(resp.ID),
stackitem.Make(req.OriginalTxID.BytesBE()),
}))
origTx, _, err := ic.DAO.GetTransaction(req.OriginalTxID)
if err != nil {
return ErrRequestNotFound
}
ic.UseSigners(origTx.Signers)
defer ic.UseSigners(nil)
userData, err := stackitem.Deserialize(req.UserData)
if err != nil {
return err
}
args := []stackitem.Item{
stackitem.Make(req.URL),
userData,
stackitem.Make(resp.Code),
stackitem.Make(resp.Result),
}
cs, err := ic.GetContract(req.CallbackContract)
if err != nil {
return err
}
return contract.CallFromNative(ic, o.Hash, cs, req.CallbackMethod, args, false)
}
func (o *Oracle) request(ic *interop.Context, args []stackitem.Item) stackitem.Item {
url, err := stackitem.ToString(args[0])
if err != nil {
panic(err)
}
var filter *string
_, ok := args[1].(stackitem.Null)
if !ok {
// Check UTF-8 validity.
str, err := stackitem.ToString(args[1])
if err != nil {
panic(err)
}
filter = &str
}
cb, err := stackitem.ToString(args[2])
if err != nil {
panic(err)
}
userData := args[3]
gas, err := args[4].TryInteger()
if err != nil {
panic(err)
}
if !ic.VM.AddGas(o.getPriceInternal(ic.DAO)) {
panic("insufficient gas")
}
if err := o.RequestInternal(ic, url, filter, cb, userData, gas); err != nil {
panic(err)
}
return stackitem.Null{}
}
// RequestInternal processes an oracle request.
func (o *Oracle) RequestInternal(ic *interop.Context, url string, filter *string, cb string, userData stackitem.Item, gas *big.Int) error {
if len(url) > maxURLLength || (filter != nil && len(*filter) > maxFilterLength) || len(cb) > maxCallbackLength || !gas.IsInt64() {
return ErrBigArgument
}
if gas.Int64() < MinimumResponseGas {
return ErrLowResponseGas
}
if strings.HasPrefix(cb, "_") {
return errors.New("disallowed callback method (starts with '_')")
}
if !ic.VM.AddGas(gas.Int64()) {
return ErrNotEnoughGas
}
callingHash := ic.VM.GetCallingScriptHash()
o.GAS.mint(ic, o.Hash, gas, false)
si := ic.DAO.GetStorageItem(o.ID, prefixRequestID)
itemID := bigint.FromBytes(si)
id := itemID.Uint64()
itemID.Add(itemID, intOne)
ic.DAO.PutBigInt(o.ID, prefixRequestID, itemID)
// Should be executed from the contract.
_, err := ic.GetContract(ic.VM.GetCallingScriptHash())
if err != nil {
return err
}
data, err := ic.DAO.GetItemCtx().Serialize(userData, false)
if err != nil {
return err
}
if len(data) > maxUserDataLength {
return ErrBigArgument
}
data = slice.Copy(data) // Serialization context will be used in PutRequestInternal again.
var filterNotif stackitem.Item
if filter != nil {
filterNotif = stackitem.Make(*filter)
} else {
filterNotif = stackitem.Null{}
}
ic.AddNotification(o.Hash, "OracleRequest", stackitem.NewArray([]stackitem.Item{
stackitem.Make(id),
stackitem.Make(ic.VM.GetCallingScriptHash().BytesBE()),
stackitem.Make(url),
filterNotif,
}))
req := &state.OracleRequest{
OriginalTxID: o.getOriginalTxID(ic.DAO, ic.Tx),
GasForResponse: gas.Uint64(),
URL: url,
Filter: filter,
CallbackContract: callingHash,
CallbackMethod: cb,
UserData: data,
}
return o.PutRequestInternal(id, req, ic.DAO)
}
// PutRequestInternal puts the oracle request with the specified id to d.
func (o *Oracle) PutRequestInternal(id uint64, req *state.OracleRequest, d *dao.Simple) error {
reqKey := makeRequestKey(id)
if err := putConvertibleToDAO(o.ID, d, reqKey, req); err != nil {
return err
}
orc, _ := o.Module.Load().(*OracleService)
if orc != nil && *orc != nil {
o.newRequests[id] = req
}
// Add request ID to the id list.
lst := new(IDList)
key := makeIDListKey(req.URL)
if err := o.getConvertibleFromDAO(d, key, lst); err != nil && !errors.Is(err, storage.ErrKeyNotFound) {
return err
}
if len(*lst) >= maxRequestsCount {
return fmt.Errorf("there are too many pending requests for %s url", req.URL)
}
*lst = append(*lst, id)
return putConvertibleToDAO(o.ID, d, key, lst)
}
// GetScriptHash returns script hash of oracle nodes.
func (o *Oracle) GetScriptHash(d *dao.Simple) (util.Uint160, error) {
return o.Desig.GetLastDesignatedHash(d, noderoles.Oracle)
}
// GetOracleNodes returns public keys of oracle nodes.
func (o *Oracle) GetOracleNodes(d *dao.Simple) (keys.PublicKeys, error) {
nodes, _, err := o.Desig.GetDesignatedByRole(d, noderoles.Oracle, math.MaxUint32)
return nodes, err
}
// GetRequestInternal returns the request by ID and key under which it is stored.
func (o *Oracle) GetRequestInternal(d *dao.Simple, id uint64) (*state.OracleRequest, error) {
key := makeRequestKey(id)
req := new(state.OracleRequest)
return req, o.getConvertibleFromDAO(d, key, req)
}
// GetIDListInternal returns the request by ID and key under which it is stored.
func (o *Oracle) GetIDListInternal(d *dao.Simple, url string) (*IDList, error) {
key := makeIDListKey(url)
idList := new(IDList)
return idList, o.getConvertibleFromDAO(d, key, idList)
}
func (o *Oracle) verify(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.NewBool(ic.Tx.HasAttribute(transaction.OracleResponseT))
}
func (o *Oracle) getPrice(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.NewBigInteger(big.NewInt(o.getPriceInternal(ic.DAO)))
}
func (o *Oracle) getPriceInternal(d *dao.Simple) int64 {
cache := d.GetROCache(o.ID).(*OracleCache)
return cache.requestPrice
}
func (o *Oracle) setPrice(ic *interop.Context, args []stackitem.Item) stackitem.Item {
price := toBigInt(args[0])
if price.Sign() <= 0 || !price.IsInt64() {
panic("invalid register price")
}
if !o.NEO.checkCommittee(ic) {
panic("invalid committee signature")
}
setIntWithKey(o.ID, ic.DAO, prefixRequestPrice, price.Int64())
cache := ic.DAO.GetRWCache(o.ID).(*OracleCache)
cache.requestPrice = price.Int64()
return stackitem.Null{}
}
func (o *Oracle) getOriginalTxID(d *dao.Simple, tx *transaction.Transaction) util.Uint256 {
for i := range tx.Attributes {
if tx.Attributes[i].Type == transaction.OracleResponseT {
id := tx.Attributes[i].Value.(*transaction.OracleResponse).ID
req, _ := o.GetRequestInternal(d, id)
return req.OriginalTxID
}
}
return tx.Hash()
}
// GetRequests returns all requests which have not been finished yet.
func (o *Oracle) GetRequests(d *dao.Simple) (map[uint64]*state.OracleRequest, error) {
var reqs = make(map[uint64]*state.OracleRequest)
var err error
d.Seek(o.ID, storage.SeekRange{Prefix: prefixRequest}, func(k, v []byte) bool {
if len(k) != 8 {
err = errors.New("invalid request ID")
return false
}
req := new(state.OracleRequest)
err = stackitem.DeserializeConvertible(v, req)
if err != nil {
return false
}
id := binary.BigEndian.Uint64(k)
reqs[id] = req
return true
})
if err != nil {
return nil, err
}
return reqs, nil
}
func makeRequestKey(id uint64) []byte {
k := make([]byte, 9)
k[0] = prefixRequest[0]
binary.BigEndian.PutUint64(k[1:], id)
return k
}
func makeIDListKey(url string) []byte {
return append(prefixIDList, hash.Hash160([]byte(url)).BytesBE()...)
}
func (o *Oracle) getConvertibleFromDAO(d *dao.Simple, key []byte, item stackitem.Convertible) error {
return getConvertibleFromDAO(o.ID, d, key, item)
}
// updateCache updates cached Oracle values if they've been changed.
func (o *Oracle) updateCache(d *dao.Simple) error {
orc, _ := o.Module.Load().(*OracleService)
if orc == nil || *orc == nil {
return nil
}
reqs := o.newRequests
o.newRequests = make(map[uint64]*state.OracleRequest)
for id := range reqs {
key := makeRequestKey(id)
if si := d.GetStorageItem(o.ID, key); si == nil { // tx has failed
delete(reqs, id)
}
}
(*orc).AddRequests(reqs)
return nil
}
// CreateOracleResponseScript returns a script that is used to create the native Oracle
// response.
func CreateOracleResponseScript(nativeOracleHash util.Uint160) []byte {
script, err := smartcontract.CreateCallScript(nativeOracleHash, "finish")
if err != nil {
panic(fmt.Errorf("failed to create Oracle response script: %w", err))
}
return script
}