package vm import ( "bytes" "context" "fmt" "math/big" block "github.com/ipfs/go-block-format" cid "github.com/ipfs/go-cid" hamt "github.com/ipfs/go-hamt-ipld" blockstore "github.com/ipfs/go-ipfs-blockstore" logging "github.com/ipfs/go-log" cbg "github.com/whyrusleeping/cbor-gen" "go.opencensus.io/trace" "golang.org/x/xerrors" "github.com/filecoin-project/go-address" "github.com/filecoin-project/lotus/build" "github.com/filecoin-project/lotus/chain/actors" "github.com/filecoin-project/lotus/chain/actors/aerrors" "github.com/filecoin-project/lotus/chain/state" "github.com/filecoin-project/lotus/chain/types" "github.com/filecoin-project/lotus/lib/bufbstore" ) 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 sys *types.VMSyscalls // root cid of the state of the actor this invocation will be on sroot cid.Cid // address that started invoke 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) { res, err := vmc.vm.rand.GetRandomness(vmc.ctx, int64(height)) if err != nil { return nil, aerrors.Escalate(err, "could not get randomness") } return res, nil } func (vmc *VMContext) Sys() *types.VMSyscalls { return vmc.sys } // Storage interface func (vmc *VMContext) Put(i cbg.CBORMarshaler) (cid.Cid, aerrors.ActorError) { c, err := vmc.cst.Put(context.TODO(), i) if err != nil { return cid.Undef, aerrors.HandleExternalError(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 { return aerrors.HandleExternalError(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 vmc.gasUsed.GreaterThan(vmc.gasAvailable) { 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.InitAddress { 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.AccountCodeCid { 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: return types.NewInt(0), nil case nil: return act.Balance, nil } } func (vmctx *VMContext) Context() context.Context { return vmctx.ctx } 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, sys: vm.Syscalls, 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 cst *hamt.CborIpldStore buf *bufbstore.BufferedBS blockHeight uint64 blockMiner address.Address inv *invoker rand Rand Syscalls *types.VMSyscalls } func NewVM(base cid.Cid, height uint64, r Rand, maddr address.Address, cbs blockstore.Blockstore) (*VM, error) { buf := bufbstore.NewBufferedBstore(cbs) cst := hamt.CSTFromBstore(buf) state, err := state.LoadStateTree(cst, base) if err != nil { return nil, err } return &VM{ cstate: state, base: base, cst: cst, buf: buf, blockHeight: height, blockMiner: maddr, inv: newInvoker(), rand: r, Syscalls: DefaultSyscalls(), }, nil } type Rand interface { GetRandomness(ctx context.Context, h int64) ([]byte, error) } 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 := Transfer(fromActor, toActor, msg.Value); err != nil { return nil, aerrors.Absorb(err, 1, "failed to transfer funds"), nil } } if msg.Method != 0 { ret, err := vm.Invoke(toActor, vmctx, msg.Method, msg.Params) if !aerrors.IsFatal(err) { 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 span.IsRecordingEvents() { span.AddAttributes( trace.StringAttribute("to", msg.To.String()), trace.Int64Attribute("method", int64(msg.Method)), trace.StringAttribute("value", msg.Value.String()), ) } 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 fromActor.Balance.LessThan(totalCost) { return nil, xerrors.Errorf("not enough funds (%s < %s)", fromActor.Balance, totalCost) } gasHolder := &types.Actor{Balance: types.NewInt(0)} if err := Transfer(fromActor, gasHolder, gascost); err != nil { return nil, xerrors.Errorf("failed to withdraw gas 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("[from=%s,to=%s,n=%d,m=%d,h=%d] fatal error: %w", msg.From, msg.To, msg.Nonce, msg.Method, vm.blockHeight, actorErr) } if actorErr != nil { log.Warnf("[from=%s,to=%s,n=%d,m=%d,h=%d] Send actor error: %+v", msg.From, msg.To, msg.Nonce, msg.Method, vm.blockHeight, 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) if err := Transfer(gasHolder, fromActor, refund); err != nil { return nil, xerrors.Errorf("failed to refund gas") } } miner, err := st.GetActor(vm.blockMiner) if err != nil { return nil, xerrors.Errorf("getting block miner actor (%s) failed: %w", vm.blockMiner, err) } // TODO: support multiple blocks in a tipset // TODO: actually wire this up (miner is undef for now) gasReward := types.BigMul(msg.GasPrice, gasUsed) if err := Transfer(gasHolder, miner, gasReward); err != nil { return nil, xerrors.Errorf("failed to give miner gas reward: %w", err) } if types.BigCmp(types.NewInt(0), gasHolder.Balance) != 0 { return nil, xerrors.Errorf("gas handling math is wrong") } 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) { _, span := trace.StartSpan(ctx, "vm.Flush") defer span.End() from := vm.buf to := vm.buf.Read() root, err := vm.cstate.Flush() if err != nil { return cid.Undef, xerrors.Errorf("flushing vm: %w", err) } if err := Copy(from, to, root); err != nil { return cid.Undef, xerrors.Errorf("copying tree: %w", err) } return root, nil } func linksForObj(blk block.Block) ([]cid.Cid, error) { switch blk.Cid().Prefix().Codec { case cid.DagCBOR: return cbg.ScanForLinks(bytes.NewReader(blk.RawData())) default: return nil, xerrors.Errorf("vm flush copy method only supports dag cbor") } } func Copy(from, to blockstore.Blockstore, root cid.Cid) error { var batch []block.Block batchCp := func(blk block.Block) error { batch = append(batch, blk) if len(batch) > 100 { if err := to.PutMany(batch); err != nil { return xerrors.Errorf("batch put in copy: %w", err) } batch = batch[:0] } return nil } if err := copyRec(from, to, root, batchCp); err != nil { return err } if len(batch) > 0 { if err := to.PutMany(batch); err != nil { return xerrors.Errorf("batch put in copy: %w", err) } } return nil } func copyRec(from, to blockstore.Blockstore, root cid.Cid, cp func(block.Block) error) error { if root.Prefix().MhType == 0 { // identity cid, skip return nil } blk, err := from.Get(root) if err != nil { return xerrors.Errorf("get %s failed: %w", root, err) } links, err := linksForObj(blk) if err != nil { return err } for _, link := range links { if link.Prefix().MhType == 0 { continue } has, err := to.Has(link) if err != nil { return err } if has { continue } if err := copyRec(from, to, link, cp); err != nil { return err } } if err := cp(blk); err != nil { return err } return nil } func (vm *VM) StateTree() types.StateTree { return vm.cstate } 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() if span.IsRecordingEvents() { span.AddAttributes( trace.StringAttribute("to", vmctx.Message().To.String()), trace.Int64Attribute("method", int64(method)), trace.StringAttribute("value", vmctx.Message().Value.String()), ) } 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 Transfer(from, to *types.Actor, amt types.BigInt) error { if from == to { return nil } if amt.LessThan(types.NewInt(0)) { return xerrors.Errorf("attempted to transfer negative value") } if err := deductFunds(from, amt); err != nil { return err } depositFunds(to, amt) return nil } func deductFunds(act *types.Actor, amt types.BigInt) error { if act.Balance.LessThan(amt) { 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) } var miningRewardTotal = types.FromFil(build.MiningRewardTotal) var blocksPerEpoch = types.NewInt(build.BlocksPerEpoch) // MiningReward returns correct mining reward // coffer is amount of FIL in NetworkAddress func MiningReward(remainingReward types.BigInt) types.BigInt { ci := big.NewInt(0).Set(remainingReward.Int) res := ci.Mul(ci, build.InitialReward) res = res.Div(res, miningRewardTotal.Int) res = res.Div(res, blocksPerEpoch.Int) return types.BigInt{res} }