lotus/chain/vm/vm.go
2019-09-19 22:23:24 -07:00

608 lines
15 KiB
Go

package vm
import (
"context"
"fmt"
"github.com/filecoin-project/go-lotus/chain/actors"
"github.com/filecoin-project/go-lotus/chain/actors/aerrors"
"github.com/filecoin-project/go-lotus/chain/address"
"github.com/filecoin-project/go-lotus/chain/state"
"github.com/filecoin-project/go-lotus/chain/store"
"github.com/filecoin-project/go-lotus/chain/types"
"github.com/filecoin-project/go-lotus/lib/bufbstore"
cbg "github.com/whyrusleeping/cbor-gen"
"go.opencensus.io/trace"
block "github.com/ipfs/go-block-format"
bserv "github.com/ipfs/go-blockservice"
cid "github.com/ipfs/go-cid"
hamt "github.com/ipfs/go-hamt-ipld"
ipld "github.com/ipfs/go-ipld-format"
logging "github.com/ipfs/go-log"
dag "github.com/ipfs/go-merkledag"
"golang.org/x/xerrors"
)
var log = logging.Logger("vm")
const (
gasFundTransfer = 10
gasInvoke = 5
gasGetObj = 10
gasGetPerByte = 1
gasPutObj = 20
gasPutPerByte = 2
gasCommit = 50
gasPerMessageByte = 2
)
const (
outOfGasErrCode = 200
)
type VMContext struct {
ctx context.Context
vm *VM
state *state.StateTree
msg *types.Message
height uint64
cst *hamt.CborIpldStore
gasAvailable types.BigInt
gasUsed types.BigInt
// root cid of the state of the actor this invocation will be on
sroot cid.Cid
// address that started invokation chain
origin address.Address
}
// Message is the message that kicked off the current invocation
func (vmc *VMContext) Message() *types.Message {
return vmc.msg
}
func (vmc *VMContext) GetRandomness(height uint64) ([]byte, aerrors.ActorError) {
relHeight := int(vmc.BlockHeight()) - int(height)
res, err := vmc.vm.cs.GetRandomness(vmc.ctx, vmc.vm.cs.GetHeaviestTipSet(), nil, relHeight)
if err != nil {
return nil, aerrors.Escalate(err, "could not get randomness")
}
return res, nil
}
// Storage interface
func (vmc *VMContext) Put(i cbg.CBORMarshaler) (cid.Cid, aerrors.ActorError) {
c, err := vmc.cst.Put(context.TODO(), i)
if err != nil {
if aerr := vmc.ChargeGas(0); aerr != nil {
return cid.Undef, aerrors.Absorb(err, outOfGasErrCode, "Put out of gas")
}
return cid.Undef, aerrors.Escalate(err, fmt.Sprintf("putting object %T", i))
}
return c, nil
}
func (vmc *VMContext) Get(c cid.Cid, out cbg.CBORUnmarshaler) aerrors.ActorError {
err := vmc.cst.Get(context.TODO(), c, out)
if err != nil {
if aerr := vmc.ChargeGas(0); aerr != nil {
return aerrors.Absorb(err, outOfGasErrCode, "Get out of gas")
}
return aerrors.Escalate(err, "getting cid")
}
return nil
}
func (vmc *VMContext) GetHead() cid.Cid {
return vmc.sroot
}
func (vmc *VMContext) Commit(oldh, newh cid.Cid) aerrors.ActorError {
if err := vmc.ChargeGas(gasCommit); err != nil {
return aerrors.Wrap(err, "out of gas")
}
if vmc.sroot != oldh {
return aerrors.New(1, "failed to update, inconsistent base reference")
}
vmc.sroot = newh
return nil
}
// End of storage interface
// Storage provides access to the VM storage layer
func (vmc *VMContext) Storage() types.Storage {
return vmc
}
func (vmc *VMContext) Ipld() *hamt.CborIpldStore {
return vmc.cst
}
func (vmc *VMContext) Origin() address.Address {
return vmc.origin
}
// Send allows the current execution context to invoke methods on other actors in the system
func (vmc *VMContext) Send(to address.Address, method uint64, value types.BigInt, params []byte) ([]byte, aerrors.ActorError) {
ctx, span := trace.StartSpan(vmc.ctx, "vmc.Send")
defer span.End()
if span.IsRecordingEvents() {
span.AddAttributes(
trace.StringAttribute("to", to.String()),
trace.Int64Attribute("method", int64(method)),
trace.StringAttribute("value", value.String()),
)
}
msg := &types.Message{
From: vmc.msg.To,
To: to,
Method: method,
Value: value,
Params: params,
GasLimit: vmc.gasAvailable,
}
ret, err, _ := vmc.vm.send(ctx, msg, vmc, 0)
return ret, err
}
// BlockHeight returns the height of the block this message was added to the chain in
func (vmc *VMContext) BlockHeight() uint64 {
return vmc.height
}
func (vmc *VMContext) GasUsed() types.BigInt {
return vmc.gasUsed
}
func (vmc *VMContext) ChargeGas(amount uint64) aerrors.ActorError {
toUse := types.NewInt(amount)
vmc.gasUsed = types.BigAdd(vmc.gasUsed, toUse)
if types.BigCmp(vmc.gasUsed, vmc.gasAvailable) > 0 {
return aerrors.Newf(outOfGasErrCode, "not enough gas: used=%s, available=%s", vmc.gasUsed, vmc.gasAvailable)
}
return nil
}
func (vmc *VMContext) StateTree() (types.StateTree, aerrors.ActorError) {
if vmc.msg.To != actors.InitActorAddress {
return nil, aerrors.Escalate(fmt.Errorf("only init actor can access state tree directly"), "invalid use of StateTree")
}
return vmc.state, nil
}
const GasVerifySignature = 50
func (vmctx *VMContext) VerifySignature(sig *types.Signature, act address.Address, data []byte) aerrors.ActorError {
if err := vmctx.ChargeGas(GasVerifySignature); err != nil {
return err
}
if act.Protocol() == address.ID {
kaddr, err := ResolveToKeyAddr(vmctx.state, vmctx.cst, act)
if err != nil {
return aerrors.Wrap(err, "failed to resolve address to key address")
}
act = kaddr
}
if err := sig.Verify(act, data); err != nil {
return aerrors.New(2, "signature verification failed")
}
return nil
}
func ResolveToKeyAddr(state types.StateTree, cst *hamt.CborIpldStore, addr address.Address) (address.Address, aerrors.ActorError) {
if addr.Protocol() == address.BLS || addr.Protocol() == address.SECP256K1 {
return addr, nil
}
act, err := state.GetActor(addr)
if err != nil {
return address.Undef, aerrors.Newf(1, "failed to find actor: %s", addr)
}
if act.Code != actors.AccountActorCodeCid {
return address.Undef, aerrors.New(1, "address was not for an account actor")
}
var aast actors.AccountActorState
if err := cst.Get(context.TODO(), act.Head, &aast); err != nil {
return address.Undef, aerrors.Escalate(err, fmt.Sprintf("failed to get account actor state for %s", addr))
}
return aast.Address, nil
}
func (vmctx *VMContext) GetBalance(a address.Address) (types.BigInt, aerrors.ActorError) {
act, err := vmctx.state.GetActor(a)
switch err {
default:
return types.EmptyInt, aerrors.Escalate(err, "failed to look up actor balance")
case hamt.ErrNotFound:
// REVIEW: should we just say 'account doesnt exist' == '0 balance'?
return types.NewInt(0), nil
case nil:
return act.Balance, nil
}
}
type hBlocks interface {
GetBlock(context.Context, cid.Cid) (block.Block, error)
AddBlock(block.Block) error
}
var _ hBlocks = (*gasChargingBlocks)(nil)
type gasChargingBlocks struct {
chargeGas func(uint64) aerrors.ActorError
under hBlocks
}
func (bs *gasChargingBlocks) GetBlock(ctx context.Context, c cid.Cid) (block.Block, error) {
if err := bs.chargeGas(gasGetObj); err != nil {
return nil, err
}
blk, err := bs.under.GetBlock(ctx, c)
if err != nil {
return nil, err
}
if err := bs.chargeGas(uint64(len(blk.RawData())) * gasGetPerByte); err != nil {
return nil, err
}
return blk, nil
}
func (bs *gasChargingBlocks) AddBlock(blk block.Block) error {
if err := bs.chargeGas(gasPutObj + uint64(len(blk.RawData()))*gasPutPerByte); err != nil {
return err
}
return bs.under.AddBlock(blk)
}
func (vm *VM) makeVMContext(ctx context.Context, sroot cid.Cid, msg *types.Message, origin address.Address, usedGas types.BigInt) *VMContext {
vmc := &VMContext{
ctx: ctx,
vm: vm,
state: vm.cstate,
sroot: sroot,
msg: msg,
origin: origin,
height: vm.blockHeight,
gasUsed: usedGas,
gasAvailable: msg.GasLimit,
}
vmc.cst = &hamt.CborIpldStore{
Blocks: &gasChargingBlocks{vmc.ChargeGas, vm.cst.Blocks},
Atlas: vm.cst.Atlas,
}
return vmc
}
type VM struct {
cstate *state.StateTree
base cid.Cid
cs *store.ChainStore
cst *hamt.CborIpldStore
buf *bufbstore.BufferedBS
blockHeight uint64
blockMiner address.Address
inv *invoker
}
func NewVM(base cid.Cid, height uint64, maddr address.Address, cs *store.ChainStore) (*VM, error) {
buf := bufbstore.NewBufferedBstore(cs.Blockstore())
cst := hamt.CSTFromBstore(buf)
state, err := state.LoadStateTree(cst, base)
if err != nil {
return nil, err
}
return &VM{
cstate: state,
base: base,
cs: cs,
cst: cst,
buf: buf,
blockHeight: height,
blockMiner: maddr,
inv: newInvoker(),
}, nil
}
type ApplyRet struct {
types.MessageReceipt
ActorErr aerrors.ActorError
}
func (vm *VM) send(ctx context.Context, msg *types.Message, parent *VMContext,
gasCharge uint64) ([]byte, aerrors.ActorError, *VMContext) {
st := vm.cstate
fromActor, err := st.GetActor(msg.From)
if err != nil {
return nil, aerrors.Absorb(err, 1, "could not find source actor"), nil
}
toActor, err := st.GetActor(msg.To)
if err != nil {
if xerrors.Is(err, types.ErrActorNotFound) {
a, err := TryCreateAccountActor(st, msg.To)
if err != nil {
return nil, aerrors.Absorb(err, 1, "could not create account"), nil
}
toActor = a
} else {
return nil, aerrors.Escalate(err, "getting actor"), nil
}
}
gasUsed := types.NewInt(gasCharge)
origin := msg.From
if parent != nil {
gasUsed = types.BigAdd(parent.gasUsed, gasUsed)
origin = parent.origin
}
vmctx := vm.makeVMContext(ctx, toActor.Head, msg, origin, gasUsed)
if parent != nil {
defer func() {
parent.gasUsed = vmctx.gasUsed
}()
}
if types.BigCmp(msg.Value, types.NewInt(0)) != 0 {
if aerr := vmctx.ChargeGas(gasFundTransfer); aerr != nil {
return nil, aerrors.Wrap(aerr, "sending funds"), nil
}
if err := DeductFunds(fromActor, msg.Value); err != nil {
return nil, aerrors.Absorb(err, 1, "failed to deduct funds"), nil
}
DepositFunds(toActor, msg.Value)
}
if msg.Method != 0 {
ret, err := vm.Invoke(toActor, vmctx, msg.Method, msg.Params)
toActor.Head = vmctx.Storage().GetHead()
return ret, err, vmctx
}
return nil, nil, vmctx
}
func checkMessage(msg *types.Message) error {
if msg.GasLimit == types.EmptyInt {
return xerrors.Errorf("message gas no gas limit set")
}
if msg.GasPrice == types.EmptyInt {
return xerrors.Errorf("message gas no gas price set")
}
if msg.Value == types.EmptyInt {
return xerrors.Errorf("message no value set")
}
return nil
}
func (vm *VM) ApplyMessage(ctx context.Context, msg *types.Message) (*ApplyRet, error) {
ctx, span := trace.StartSpan(ctx, "vm.ApplyMessage")
defer span.End()
if err := checkMessage(msg); err != nil {
return nil, err
}
st := vm.cstate
if err := st.Snapshot(); err != nil {
return nil, xerrors.Errorf("snapshot failed: %w", err)
}
fromActor, err := st.GetActor(msg.From)
if err != nil {
return nil, xerrors.Errorf("from actor not found: %w", err)
}
serMsg, err := msg.Serialize()
if err != nil {
return nil, xerrors.Errorf("could not serialize message: %w", err)
}
msgGasCost := uint64(len(serMsg)) * gasPerMessageByte
gascost := types.BigMul(msg.GasLimit, msg.GasPrice)
totalCost := types.BigAdd(gascost, msg.Value)
if types.BigCmp(fromActor.Balance, totalCost) < 0 {
return nil, xerrors.Errorf("not enough funds (%s < %s)", fromActor.Balance, totalCost)
}
if err := DeductFunds(fromActor, gascost); err != nil {
return nil, xerrors.Errorf("failed to deduct funds: %w", err)
}
if msg.Nonce != fromActor.Nonce {
return nil, xerrors.Errorf("invalid nonce (got %d, expected %d)", msg.Nonce, fromActor.Nonce)
}
fromActor.Nonce++
ret, actorErr, vmctx := vm.send(ctx, msg, nil, msgGasCost)
if aerrors.IsFatal(actorErr) {
return nil, xerrors.Errorf("fatal error: %w", actorErr)
}
var errcode uint8
var gasUsed types.BigInt
if errcode = aerrors.RetCode(actorErr); errcode != 0 {
gasUsed = msg.GasLimit
// revert all state changes since snapshot
if err := st.Revert(); err != nil {
return nil, xerrors.Errorf("revert state failed: %w", err)
}
} else {
// refund unused gas
gasUsed = vmctx.GasUsed()
refund := types.BigMul(types.BigSub(msg.GasLimit, gasUsed), msg.GasPrice)
DepositFunds(fromActor, refund)
}
miner, err := st.GetActor(vm.blockMiner)
if err != nil {
return nil, xerrors.Errorf("getting block miner actor (%s) failed: %w", vm.blockMiner, err)
}
gasReward := types.BigMul(msg.GasPrice, gasUsed)
DepositFunds(miner, gasReward)
return &ApplyRet{
MessageReceipt: types.MessageReceipt{
ExitCode: errcode,
Return: ret,
GasUsed: gasUsed,
},
ActorErr: actorErr,
}, nil
}
func (vm *VM) SetBlockMiner(m address.Address) {
vm.blockMiner = m
}
func (vm *VM) ActorBalance(addr address.Address) (types.BigInt, aerrors.ActorError) {
act, err := vm.cstate.GetActor(addr)
if err != nil {
return types.EmptyInt, aerrors.Absorb(err, 1, "failed to find actor")
}
return act.Balance, nil
}
func (vm *VM) Flush(ctx context.Context) (cid.Cid, error) {
from := dag.NewDAGService(bserv.New(vm.buf, nil))
to := dag.NewDAGService(bserv.New(vm.buf.Read(), nil))
root, err := vm.cstate.Flush()
if err != nil {
return cid.Undef, xerrors.Errorf("flushing vm: %w", err)
}
if err := Copy(ctx, from, to, root); err != nil {
return cid.Undef, xerrors.Errorf("copying tree: %w", err)
}
return root, nil
}
func Copy(ctx context.Context, from, to ipld.DAGService, root cid.Cid) error {
if root.Prefix().MhType == 0 {
// identity cid, skip
return nil
}
node, err := from.Get(ctx, root)
if err != nil {
return xerrors.Errorf("get %s failed: %w", root, err)
}
links := node.Links()
for _, link := range links {
if link.Cid.Prefix().MhType == 0 {
continue
}
_, err := to.Get(ctx, link.Cid)
switch err {
default:
return err
case nil:
continue
case ipld.ErrNotFound:
// continue
}
if err := Copy(ctx, from, to, link.Cid); err != nil {
return err
}
}
err = to.Add(ctx, node)
if err != nil {
return err
}
return nil
}
func (vm *VM) StateTree() types.StateTree {
return vm.cstate
}
func (vm *VM) TransferFunds(from, to address.Address, amt types.BigInt) error {
if from == to {
return nil
}
fromAct, err := vm.cstate.GetActor(from)
if err != nil {
return err
}
toAct, err := vm.cstate.GetActor(from)
if err != nil {
return err
}
if err := DeductFunds(fromAct, amt); err != nil {
return xerrors.Errorf("failed to deduct funds: %w", err)
}
DepositFunds(toAct, amt)
return nil
}
func (vm *VM) SetBlockHeight(h uint64) {
vm.blockHeight = h
}
func (vm *VM) Invoke(act *types.Actor, vmctx *VMContext, method uint64, params []byte) ([]byte, aerrors.ActorError) {
ctx, span := trace.StartSpan(vmctx.ctx, "vm.Invoke")
defer span.End()
var oldCtx context.Context
oldCtx, vmctx.ctx = vmctx.ctx, ctx
defer func() {
vmctx.ctx = oldCtx
}()
if err := vmctx.ChargeGas(gasInvoke); err != nil {
return nil, aerrors.Wrap(err, "invokeing")
}
ret, err := vm.inv.Invoke(act, vmctx, method, params)
if err != nil {
return nil, err
}
return ret, nil
}
func DeductFunds(act *types.Actor, amt types.BigInt) error {
if types.BigCmp(act.Balance, amt) < 0 {
return fmt.Errorf("not enough funds")
}
act.Balance = types.BigSub(act.Balance, amt)
return nil
}
func DepositFunds(act *types.Actor, amt types.BigInt) {
act.Balance = types.BigAdd(act.Balance, amt)
}
func MiningRewardForBlock(base *types.TipSet) types.BigInt {
return types.NewInt(10000)
}