neoneo-go/pkg/core/native/ledger.go
Roman Khimov fab8dfb9f8 vm: move State type into a package of its own
It's used a lot in other places that need it, but don't need whole VM at the
same time.
2022-07-08 18:34:52 +03:00

255 lines
8.8 KiB
Go

package native
import (
"fmt"
"math"
"math/big"
"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/native/nativenames"
"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/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/stackitem"
"github.com/nspcc-dev/neo-go/pkg/vm/vmstate"
)
// Ledger provides an interface to blocks/transactions storage for smart
// contracts. It's not a part of the proper chain's state, so it's just a
// proxy between regular Blockchain/DAO interface and smart contracts.
type Ledger struct {
interop.ContractMD
}
const ledgerContractID = -4
// newLedger creates a new Ledger native contract.
func newLedger() *Ledger {
var l = &Ledger{
ContractMD: *interop.NewContractMD(nativenames.Ledger, ledgerContractID),
}
defer l.UpdateHash()
desc := newDescriptor("currentHash", smartcontract.Hash256Type)
md := newMethodAndPrice(l.currentHash, 1<<15, callflag.ReadStates)
l.AddMethod(md, desc)
desc = newDescriptor("currentIndex", smartcontract.IntegerType)
md = newMethodAndPrice(l.currentIndex, 1<<15, callflag.ReadStates)
l.AddMethod(md, desc)
desc = newDescriptor("getBlock", smartcontract.ArrayType,
manifest.NewParameter("indexOrHash", smartcontract.ByteArrayType))
md = newMethodAndPrice(l.getBlock, 1<<15, callflag.ReadStates)
l.AddMethod(md, desc)
desc = newDescriptor("getTransaction", smartcontract.ArrayType,
manifest.NewParameter("hash", smartcontract.Hash256Type))
md = newMethodAndPrice(l.getTransaction, 1<<15, callflag.ReadStates)
l.AddMethod(md, desc)
desc = newDescriptor("getTransactionHeight", smartcontract.IntegerType,
manifest.NewParameter("hash", smartcontract.Hash256Type))
md = newMethodAndPrice(l.getTransactionHeight, 1<<15, callflag.ReadStates)
l.AddMethod(md, desc)
desc = newDescriptor("getTransactionFromBlock", smartcontract.ArrayType,
manifest.NewParameter("blockIndexOrHash", smartcontract.ByteArrayType),
manifest.NewParameter("txIndex", smartcontract.IntegerType))
md = newMethodAndPrice(l.getTransactionFromBlock, 1<<16, callflag.ReadStates)
l.AddMethod(md, desc)
desc = newDescriptor("getTransactionSigners", smartcontract.ArrayType,
manifest.NewParameter("hash", smartcontract.Hash256Type))
md = newMethodAndPrice(l.getTransactionSigners, 1<<15, callflag.ReadStates)
l.AddMethod(md, desc)
desc = newDescriptor("getTransactionVMState", smartcontract.IntegerType,
manifest.NewParameter("hash", smartcontract.Hash256Type))
md = newMethodAndPrice(l.getTransactionVMState, 1<<15, callflag.ReadStates)
l.AddMethod(md, desc)
return l
}
// Metadata implements the Contract interface.
func (l *Ledger) Metadata() *interop.ContractMD {
return &l.ContractMD
}
// Initialize implements the Contract interface.
func (l *Ledger) Initialize(ic *interop.Context) error {
return nil
}
// OnPersist implements the Contract interface.
func (l *Ledger) OnPersist(ic *interop.Context) error {
// Actual block/tx processing is done in Blockchain.storeBlock().
// Even though C# node add them to storage here, they're not
// accessible to smart contracts (see isTraceableBlock()), thus
// the end effect is the same.
return nil
}
// PostPersist implements the Contract interface.
func (l *Ledger) PostPersist(ic *interop.Context) error {
return nil // Actual block/tx processing is done in Blockchain.storeBlock().
}
// currentHash implements currentHash SC method.
func (l *Ledger) currentHash(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.Make(ic.CurrentBlockHash().BytesBE())
}
// currentIndex implements currentIndex SC method.
func (l *Ledger) currentIndex(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
return stackitem.Make(ic.BlockHeight())
}
// getBlock implements getBlock SC method.
func (l *Ledger) getBlock(ic *interop.Context, params []stackitem.Item) stackitem.Item {
hash := getBlockHashFromItem(ic, params[0])
block, err := ic.GetBlock(hash)
if err != nil || !isTraceableBlock(ic, block.Index) {
return stackitem.Null{}
}
return block.ToStackItem()
}
// getTransaction returns transaction to the SC.
func (l *Ledger) getTransaction(ic *interop.Context, params []stackitem.Item) stackitem.Item {
tx, h, err := getTransactionAndHeight(ic.DAO, params[0])
if err != nil || !isTraceableBlock(ic, h) {
return stackitem.Null{}
}
return tx.ToStackItem()
}
// getTransactionHeight returns transaction height to the SC.
func (l *Ledger) getTransactionHeight(ic *interop.Context, params []stackitem.Item) stackitem.Item {
_, h, err := getTransactionAndHeight(ic.DAO, params[0])
if err != nil || !isTraceableBlock(ic, h) {
return stackitem.Make(-1)
}
return stackitem.Make(h)
}
// getTransactionFromBlock returns a transaction with the given index from the
// block with the height or hash specified.
func (l *Ledger) getTransactionFromBlock(ic *interop.Context, params []stackitem.Item) stackitem.Item {
hash := getBlockHashFromItem(ic, params[0])
index := toUint32(params[1])
block, err := ic.GetBlock(hash)
if err != nil || !isTraceableBlock(ic, block.Index) {
return stackitem.Null{}
}
if index >= uint32(len(block.Transactions)) {
panic("wrong transaction index")
}
return block.Transactions[index].ToStackItem()
}
// getTransactionSigners returns transaction signers to the SC.
func (l *Ledger) getTransactionSigners(ic *interop.Context, params []stackitem.Item) stackitem.Item {
tx, h, err := getTransactionAndHeight(ic.DAO, params[0])
if err != nil || !isTraceableBlock(ic, h) {
return stackitem.Null{}
}
return SignersToStackItem(tx.Signers)
}
// getTransactionVMState returns VM state got after transaction invocation.
func (l *Ledger) getTransactionVMState(ic *interop.Context, params []stackitem.Item) stackitem.Item {
hash, err := getUint256FromItem(params[0])
if err != nil {
panic(err)
}
h, _, aer, err := ic.DAO.GetTxExecResult(hash)
if err != nil || !isTraceableBlock(ic, h) {
return stackitem.Make(vmstate.None)
}
return stackitem.Make(aer.VMState)
}
// isTraceableBlock defines whether we're able to give information about
// the block with the index specified.
func isTraceableBlock(ic *interop.Context, index uint32) bool {
height := ic.BlockHeight()
MaxTraceableBlocks := ic.Chain.GetConfig().MaxTraceableBlocks
return index <= height && index+MaxTraceableBlocks > height
}
// getBlockHashFromItem converts the given stackitem.Item to a block hash using the given
// Ledger if needed. Interop functions accept both block numbers and
// block hashes as parameters, thus this function is needed. It's supposed to
// be called within VM context, so it panics if anything goes wrong.
func getBlockHashFromItem(ic *interop.Context, item stackitem.Item) util.Uint256 {
bigindex, err := item.TryInteger()
if err == nil && bigindex.IsUint64() {
index := bigindex.Uint64()
if index > math.MaxUint32 {
panic("bad block index")
}
if uint32(index) > ic.BlockHeight() {
panic(fmt.Errorf("no block with index %d", index))
}
return ic.Chain.GetHeaderHash(int(index))
}
hash, err := getUint256FromItem(item)
if err != nil {
panic(err)
}
return hash
}
func getUint256FromItem(item stackitem.Item) (util.Uint256, error) {
hashbytes, err := item.TryBytes()
if err != nil {
return util.Uint256{}, fmt.Errorf("failed to get hash bytes: %w", err)
}
hash, err := util.Uint256DecodeBytesBE(hashbytes)
if err != nil {
return util.Uint256{}, fmt.Errorf("failed to decode hash: %w", err)
}
return hash, nil
}
// getTransactionAndHeight returns a transaction and its height if it's present
// on the chain. It panics if anything goes wrong.
func getTransactionAndHeight(d *dao.Simple, item stackitem.Item) (*transaction.Transaction, uint32, error) {
hash, err := getUint256FromItem(item)
if err != nil {
panic(err)
}
return d.GetTransaction(hash)
}
// SignersToStackItem converts transaction.Signers to stackitem.Item.
func SignersToStackItem(signers []transaction.Signer) stackitem.Item {
res := make([]stackitem.Item, len(signers))
for i, s := range signers {
contracts := make([]stackitem.Item, len(s.AllowedContracts))
for j, c := range s.AllowedContracts {
contracts[j] = stackitem.NewByteArray(c.BytesBE())
}
groups := make([]stackitem.Item, len(s.AllowedGroups))
for j, g := range s.AllowedGroups {
groups[j] = stackitem.NewByteArray(g.Bytes())
}
rules := make([]stackitem.Item, len(s.Rules))
for j, r := range s.Rules {
rules[j] = r.ToStackItem()
}
res[i] = stackitem.NewArray([]stackitem.Item{
stackitem.NewByteArray(s.Account.BytesBE()),
stackitem.NewBigInteger(big.NewInt(int64(s.Scopes))),
stackitem.NewArray(contracts),
stackitem.NewArray(groups),
stackitem.NewArray(rules),
})
}
return stackitem.NewArray(res)
}