ac527650eb
But don't change the way we process/store transactions and blocks. Effectively it's just an interface for smart contracts that replaces old syscalls. Transaction definition is moved temporarily to runtime package and Block definition is removed (till we solve #1691 properly).
473 lines
14 KiB
Go
473 lines
14 KiB
Go
package native
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"errors"
|
|
"fmt"
|
|
"math"
|
|
"math/big"
|
|
"strings"
|
|
"sync/atomic"
|
|
|
|
"github.com/nspcc-dev/neo-go/pkg/core/blockchainer/services"
|
|
"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/interop/interopnames"
|
|
"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
|
|
"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/io"
|
|
"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/vm/emit"
|
|
"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
|
|
"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 current block.
|
|
newRequests map[uint64]*state.OracleRequest
|
|
}
|
|
|
|
const (
|
|
oracleContractID = -7
|
|
maxURLLength = 256
|
|
maxFilterLength = 128
|
|
maxCallbackLength = 32
|
|
maxUserDataLength = 512
|
|
// maxRequestsCount is the maximum number of requests per URL
|
|
maxRequestsCount = 256
|
|
|
|
oracleRequestPrice = 5000_0000
|
|
)
|
|
|
|
var (
|
|
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")
|
|
ErrNotEnoughGas = errors.New("gas limit exceeded")
|
|
ErrRequestNotFound = errors.New("oracle request not found")
|
|
ErrResponseNotFound = errors.New("oracle response not found")
|
|
)
|
|
|
|
func newOracle() *Oracle {
|
|
o := &Oracle{ContractMD: *interop.NewContractMD(nativenames.Oracle, oracleContractID)}
|
|
|
|
w := io.NewBufBinWriter()
|
|
emit.Opcodes(w.BinWriter, opcode.NEWARRAY0)
|
|
emit.Int(w.BinWriter, int64(callflag.All))
|
|
emit.String(w.BinWriter, "finish")
|
|
emit.Bytes(w.BinWriter, o.Hash.BytesBE())
|
|
emit.Syscall(w.BinWriter, interopnames.SystemContractCall)
|
|
o.oracleScript = w.Bytes()
|
|
|
|
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, oracleRequestPrice, callflag.WriteStates|callflag.AllowNotify)
|
|
o.AddMethod(md, desc)
|
|
|
|
desc = newDescriptor("finish", smartcontract.VoidType)
|
|
md = newMethodAndPrice(o.finish, 0, callflag.WriteStates|callflag.AllowCall|callflag.AllowNotify)
|
|
o.AddMethod(md, desc)
|
|
|
|
desc = newDescriptor("verify", smartcontract.BoolType)
|
|
md = newMethodAndPrice(o.verify, 100_0000, 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))
|
|
|
|
return o
|
|
}
|
|
|
|
// GetOracleResponseScript returns script for transaction with oracle response.
|
|
func (o *Oracle) GetOracleResponseScript() []byte {
|
|
b := make([]byte, len(o.oracleScript))
|
|
copy(b, o.oracleScript)
|
|
return b
|
|
}
|
|
|
|
// OnPersist implements Contract interface.
|
|
func (o *Oracle) OnPersist(ic *interop.Context) error {
|
|
var err error
|
|
if o.newRequests == nil {
|
|
o.newRequests, err = o.getRequests(ic.DAO)
|
|
}
|
|
return err
|
|
}
|
|
|
|
// PostPersist represents `postPersist` method.
|
|
func (o *Oracle) PostPersist(ic *interop.Context) error {
|
|
var nodes keys.PublicKeys
|
|
var reward []big.Int
|
|
single := new(big.Int).SetUint64(oracleRequestPrice)
|
|
var removedIDs []uint64
|
|
|
|
orc, _ := o.Module.Load().(services.Oracle)
|
|
for _, tx := range ic.Block.Transactions {
|
|
resp := getResponse(tx)
|
|
if resp == nil {
|
|
continue
|
|
}
|
|
reqKey := makeRequestKey(resp.ID)
|
|
req := new(state.OracleRequest)
|
|
if err := o.getSerializableFromDAO(ic.DAO, reqKey, req); err != nil {
|
|
continue
|
|
}
|
|
if err := ic.DAO.DeleteStorageItem(o.ContractID, reqKey); err != nil {
|
|
return err
|
|
}
|
|
if orc != nil {
|
|
removedIDs = append(removedIDs, resp.ID)
|
|
}
|
|
|
|
idKey := makeIDListKey(req.URL)
|
|
idList := new(IDList)
|
|
if err := o.getSerializableFromDAO(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 {
|
|
err = ic.DAO.DeleteStorageItem(o.ContractID, idKey)
|
|
} else {
|
|
si := &state.StorageItem{Value: idList.Bytes()}
|
|
err = ic.DAO.PutStorageItem(o.ContractID, idKey, si)
|
|
}
|
|
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 != nil {
|
|
orc.RemoveRequests(removedIDs)
|
|
}
|
|
return o.updateCache(ic.DAO)
|
|
}
|
|
|
|
// Metadata returns contract metadata.
|
|
func (o *Oracle) Metadata() *interop.ContractMD {
|
|
return &o.ContractMD
|
|
}
|
|
|
|
// Initialize initializes Oracle contract.
|
|
func (o *Oracle) Initialize(ic *interop.Context) error {
|
|
si := &state.StorageItem{Value: make([]byte, 8)} // uint64(0) LE
|
|
return ic.DAO.PutStorageItem(o.ContractID, prefixRequestID, si)
|
|
}
|
|
|
|
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 oracle response.
|
|
func (o *Oracle) FinishInternal(ic *interop.Context) error {
|
|
resp := getResponse(ic.Tx)
|
|
if resp == nil {
|
|
return ErrResponseNotFound
|
|
}
|
|
req, err := o.GetRequestInternal(ic.DAO, resp.ID)
|
|
if err != nil {
|
|
return ErrRequestNotFound
|
|
}
|
|
|
|
ic.Notifications = append(ic.Notifications, state.NotificationEvent{
|
|
ScriptHash: o.Hash,
|
|
Name: "OracleResponse",
|
|
Item: stackitem.NewArray([]stackitem.Item{
|
|
stackitem.Make(resp.ID),
|
|
stackitem.Make(req.OriginalTxID.BytesBE()),
|
|
}),
|
|
})
|
|
|
|
r := io.NewBinReaderFromBuf(req.UserData)
|
|
userData := stackitem.DecodeBinaryStackItem(r)
|
|
args := []stackitem.Item{
|
|
stackitem.Make(req.URL),
|
|
stackitem.Make(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 err := o.RequestInternal(ic, url, filter, cb, userData, gas); err != nil {
|
|
panic(err)
|
|
}
|
|
return stackitem.Null{}
|
|
}
|
|
|
|
// RequestInternal processes 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.Uint64() < 1000_0000 {
|
|
return ErrBigArgument
|
|
}
|
|
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.ContractID, prefixRequestID)
|
|
id := binary.LittleEndian.Uint64(si.Value) + 1
|
|
binary.LittleEndian.PutUint64(si.Value, id)
|
|
if err := ic.DAO.PutStorageItem(o.ContractID, prefixRequestID, si); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Should be executed from contract.
|
|
_, err := ic.GetContract(ic.VM.GetCallingScriptHash())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
w := io.NewBufBinWriter()
|
|
stackitem.EncodeBinaryStackItem(userData, w.BinWriter)
|
|
if w.Err != nil {
|
|
return w.Err
|
|
}
|
|
data := w.Bytes()
|
|
if len(data) > maxUserDataLength {
|
|
return ErrBigArgument
|
|
}
|
|
|
|
var filterNotif stackitem.Item
|
|
if filter != nil {
|
|
filterNotif = stackitem.Make(*filter)
|
|
} else {
|
|
filterNotif = stackitem.Null{}
|
|
}
|
|
ic.Notifications = append(ic.Notifications, state.NotificationEvent{
|
|
ScriptHash: o.Hash,
|
|
Name: "OracleRequest",
|
|
Item: 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 oracle request with the specified id to d.
|
|
func (o *Oracle) PutRequestInternal(id uint64, req *state.OracleRequest, d dao.DAO) error {
|
|
reqItem := &state.StorageItem{Value: req.Bytes()}
|
|
reqKey := makeRequestKey(id)
|
|
if err := d.PutStorageItem(o.ContractID, reqKey, reqItem); err != nil {
|
|
return err
|
|
}
|
|
o.newRequests[id] = req
|
|
|
|
// Add request ID to the id list.
|
|
lst := new(IDList)
|
|
key := makeIDListKey(req.URL)
|
|
if err := o.getSerializableFromDAO(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)
|
|
si := &state.StorageItem{Value: lst.Bytes()}
|
|
return d.PutStorageItem(o.ContractID, key, si)
|
|
}
|
|
|
|
// GetScriptHash returns script hash or oracle nodes.
|
|
func (o *Oracle) GetScriptHash(d dao.DAO) (util.Uint160, error) {
|
|
return o.Desig.GetLastDesignatedHash(d, RoleOracle)
|
|
}
|
|
|
|
// GetOracleNodes returns public keys of oracle nodes.
|
|
func (o *Oracle) GetOracleNodes(d dao.DAO) (keys.PublicKeys, error) {
|
|
nodes, _, err := o.Desig.GetDesignatedByRole(d, RoleOracle, math.MaxUint32)
|
|
return nodes, err
|
|
}
|
|
|
|
// GetRequestInternal returns request by ID and key under which it is stored.
|
|
func (o *Oracle) GetRequestInternal(d dao.DAO, id uint64) (*state.OracleRequest, error) {
|
|
key := makeRequestKey(id)
|
|
req := new(state.OracleRequest)
|
|
return req, o.getSerializableFromDAO(d, key, req)
|
|
}
|
|
|
|
// GetIDListInternal returns request by ID and key under which it is stored.
|
|
func (o *Oracle) GetIDListInternal(d dao.DAO, url string) (*IDList, error) {
|
|
key := makeIDListKey(url)
|
|
idList := new(IDList)
|
|
return idList, o.getSerializableFromDAO(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) getOriginalTxID(d dao.DAO, 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.DAO) (map[uint64]*state.OracleRequest, error) {
|
|
m, err := d.GetStorageItemsWithPrefix(o.ContractID, prefixRequest)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
reqs := make(map[uint64]*state.OracleRequest, len(m))
|
|
for k, si := range m {
|
|
if len(k) != 8 {
|
|
return nil, errors.New("invalid request ID")
|
|
}
|
|
r := io.NewBinReaderFromBuf(si.Value)
|
|
req := new(state.OracleRequest)
|
|
req.DecodeBinary(r)
|
|
if r.Err != nil {
|
|
return nil, r.Err
|
|
}
|
|
id := binary.LittleEndian.Uint64([]byte(k))
|
|
reqs[id] = req
|
|
}
|
|
return reqs, nil
|
|
}
|
|
|
|
func makeRequestKey(id uint64) []byte {
|
|
k := make([]byte, 9)
|
|
k[0] = prefixRequest[0]
|
|
binary.LittleEndian.PutUint64(k[1:], id)
|
|
return k
|
|
}
|
|
|
|
func makeIDListKey(url string) []byte {
|
|
return append(prefixIDList, hash.Hash160([]byte(url)).BytesBE()...)
|
|
}
|
|
|
|
func (o *Oracle) getSerializableFromDAO(d dao.DAO, key []byte, item io.Serializable) error {
|
|
return getSerializableFromDAO(o.ContractID, d, key, item)
|
|
}
|
|
|
|
// updateCache updates cached Oracle values if they've been changed
|
|
func (o *Oracle) updateCache(d dao.DAO) error {
|
|
orc, _ := o.Module.Load().(services.Oracle)
|
|
if 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.ContractID, key); si == nil { // tx has failed
|
|
delete(reqs, id)
|
|
}
|
|
}
|
|
orc.AddRequests(reqs)
|
|
return nil
|
|
}
|