// Creates a 20 byte address and bumps the creator's nonce.
func (cache *TxCache) CreateAccount(creator *vm.Account) *vm.Account {
// Generate an address
nonce := creator.Nonce
creator.Nonce += 1
addr := LeftPadWord256(NewContractAddress(creator.Address.Postfix(20), int(nonce)))
// Create account from address.
account, removed := cache.accounts[addr].unpack()
if removed || account == nil {
account = &vm.Account{
Address: addr,
Balance: 0,
Code: nil,
Nonce: 0,
Permissions: cache.GetAccount(ptypes.GlobalPermissionsAddress256).Permissions,
Other: vmAccountOther{
PubKey: nil,
StorageRoot: nil,
},
}
cache.accounts[addr] = vmAccountInfo{account, false}
return account
} else {
// either we've messed up nonce handling, or sha3 is broken
PanicSanity(Fmt("Could not create account, address already exists: %X", addr))
return nil
}
}
// If the tx is invalid, an error will be returned.
// Unlike ExecBlock(), state will not be altered.
func ExecTx(blockCache *BlockCache, tx types.Tx, runCall bool, evc events.Fireable) (err error) {
// TODO: do something with fees
fees := int64(0)
_s := blockCache.State() // hack to access validators and block height
// Exec tx
switch tx := tx.(type) {
case *types.SendTx:
accounts, err := getInputs(blockCache, tx.Inputs)
if err != nil {
return err
}
// ensure all inputs have send permissions
if !hasSendPermission(blockCache, accounts) {
return fmt.Errorf("At least one input lacks permission for SendTx")
}
// add outputs to accounts map
// if any outputs don't exist, all inputs must have CreateAccount perm
accounts, err = getOrMakeOutputs(blockCache, accounts, tx.Outputs)
if err != nil {
return err
}
signBytes := acm.SignBytes(_s.ChainID, tx)
inTotal, err := validateInputs(accounts, signBytes, tx.Inputs)
if err != nil {
return err
}
outTotal, err := validateOutputs(tx.Outputs)
if err != nil {
return err
}
if outTotal > inTotal {
return types.ErrTxInsufficientFunds
}
fee := inTotal - outTotal
fees += fee
// Good! Adjust accounts
adjustByInputs(accounts, tx.Inputs)
adjustByOutputs(accounts, tx.Outputs)
for _, acc := range accounts {
blockCache.UpdateAccount(acc)
}
// if the evc is nil, nothing will happen
if evc != nil {
for _, i := range tx.Inputs {
evc.FireEvent(types.EventStringAccInput(i.Address), types.EventDataTx{tx, nil, ""})
}
for _, o := range tx.Outputs {
evc.FireEvent(types.EventStringAccOutput(o.Address), types.EventDataTx{tx, nil, ""})
}
}
return nil
case *types.CallTx:
var inAcc, outAcc *acm.Account
// Validate input
inAcc = blockCache.GetAccount(tx.Input.Address)
if inAcc == nil {
log.Info(Fmt("Can't find in account %X", tx.Input.Address))
return types.ErrTxInvalidAddress
}
createContract := len(tx.Address) == 0
if createContract {
if !hasCreateContractPermission(blockCache, inAcc) {
return fmt.Errorf("Account %X does not have CreateContract permission", tx.Input.Address)
}
} else {
if !hasCallPermission(blockCache, inAcc) {
return fmt.Errorf("Account %X does not have Call permission", tx.Input.Address)
}
}
// pubKey should be present in either "inAcc" or "tx.Input"
if err := checkInputPubKey(inAcc, tx.Input); err != nil {
log.Info(Fmt("Can't find pubkey for %X", tx.Input.Address))
return err
}
signBytes := acm.SignBytes(_s.ChainID, tx)
err := validateInput(inAcc, signBytes, tx.Input)
if err != nil {
log.Info(Fmt("validateInput failed on %X: %v", tx.Input.Address, err))
return err
}
if tx.Input.Amount < tx.Fee {
log.Info(Fmt("Sender did not send enough to cover the fee %X", tx.Input.Address))
return types.ErrTxInsufficientFunds
}
if !createContract {
// Validate output
if len(tx.Address) != 20 {
log.Info(Fmt("Destination address is not 20 bytes %X", tx.Address))
return types.ErrTxInvalidAddress
}
// check if its a native contract
if vm.RegisteredNativeContract(LeftPadWord256(tx.Address)) {
return fmt.Errorf("NativeContracts can not be called using CallTx. Use a contract or the appropriate tx type (eg. PermissionsTx, NameTx)")
}
// Output account may be nil if we are still in mempool and contract was created in same block as this tx
// but that's fine, because the account will be created properly when the create tx runs in the block
// and then this won't return nil. otherwise, we take their fee
outAcc = blockCache.GetAccount(tx.Address)
}
log.Info(Fmt("Out account: %v", outAcc))
// Good!
value := tx.Input.Amount - tx.Fee
inAcc.Sequence += 1
inAcc.Balance -= tx.Fee
blockCache.UpdateAccount(inAcc)
// The logic in runCall MUST NOT return.
if runCall {
// VM call variables
var (
gas int64 = tx.GasLimit
err error = nil
caller *vm.Account = toVMAccount(inAcc)
callee *vm.Account = nil // initialized below
code []byte = nil
ret []byte = nil
txCache = NewTxCache(blockCache)
params = vm.Params{
BlockHeight: int64(_s.LastBlockHeight),
BlockHash: LeftPadWord256(_s.LastBlockHash),
BlockTime: _s.LastBlockTime.Unix(),
GasLimit: _s.GetGasLimit(),
}
)
if !createContract && (outAcc == nil || len(outAcc.Code) == 0) {
// if you call an account that doesn't exist
// or an account with no code then we take fees (sorry pal)
// NOTE: it's fine to create a contract and call it within one
// block (nonce will prevent re-ordering of those txs)
// but to create with one contract and call with another
// you have to wait a block to avoid a re-ordering attack
// that will take your fees
if outAcc == nil {
log.Info(Fmt("%X tries to call %X but it does not exist.",
inAcc.Address, tx.Address))
} else {
log.Info(Fmt("%X tries to call %X but code is blank.",
inAcc.Address, tx.Address))
}
err = types.ErrTxInvalidAddress
goto CALL_COMPLETE
}
// get or create callee
if createContract {
// We already checked for permission
callee = txCache.CreateAccount(caller)
log.Info(Fmt("Created new contract %X", callee.Address))
code = tx.Data
} else {
callee = toVMAccount(outAcc)
log.Info(Fmt("Calling contract %X with code %X", callee.Address, callee.Code))
code = callee.Code
}
log.Info(Fmt("Code for this contract: %X", code))
// Run VM call and sync txCache to blockCache.
{ // Capture scope for goto.
// Write caller/callee to txCache.
txCache.UpdateAccount(caller)
txCache.UpdateAccount(callee)
vmach := vm.NewVM(txCache, params, caller.Address, types.TxID(_s.ChainID, tx))
vmach.SetFireable(evc)
// NOTE: Call() transfers the value from caller to callee iff call succeeds.
ret, err = vmach.Call(caller, callee, code, tx.Data, value, &gas)
if err != nil {
// Failure. Charge the gas fee. The 'value' was otherwise not transferred.
log.Info(Fmt("Error on execution: %v", err))
goto CALL_COMPLETE
}
log.Info("Successful execution")
if createContract {
callee.Code = ret
}
txCache.Sync()
}
CALL_COMPLETE: // err may or may not be nil.
// Create a receipt from the ret and whether errored.
log.Notice("VM call complete", "caller", caller, "callee", callee, "return", ret, "err", err)
// Fire Events for sender and receiver
// a separate event will be fired from vm for each additional call
if evc != nil {
exception := ""
if err != nil {
exception = err.Error()
}
evc.FireEvent(types.EventStringAccInput(tx.Input.Address), types.EventDataTx{tx, ret, exception})
evc.FireEvent(types.EventStringAccOutput(tx.Address), types.EventDataTx{tx, ret, exception})
}
} else {
// The mempool does not call txs until
// the proposer determines the order of txs.
// So mempool will skip the actual .Call(),
// and only deduct from the caller's balance.
inAcc.Balance -= value
if createContract {
inAcc.Sequence += 1
}
blockCache.UpdateAccount(inAcc)
}
return nil
case *types.NameTx:
var inAcc *acm.Account
// Validate input
inAcc = blockCache.GetAccount(tx.Input.Address)
if inAcc == nil {
log.Info(Fmt("Can't find in account %X", tx.Input.Address))
return types.ErrTxInvalidAddress
}
// check permission
if !hasNamePermission(blockCache, inAcc) {
return fmt.Errorf("Account %X does not have Name permission", tx.Input.Address)
}
// pubKey should be present in either "inAcc" or "tx.Input"
if err := checkInputPubKey(inAcc, tx.Input); err != nil {
log.Info(Fmt("Can't find pubkey for %X", tx.Input.Address))
return err
}
signBytes := acm.SignBytes(_s.ChainID, tx)
err := validateInput(inAcc, signBytes, tx.Input)
if err != nil {
log.Info(Fmt("validateInput failed on %X: %v", tx.Input.Address, err))
return err
}
// fee is in addition to the amount which is used to determine the TTL
if tx.Input.Amount < tx.Fee {
log.Info(Fmt("Sender did not send enough to cover the fee %X", tx.Input.Address))
return types.ErrTxInsufficientFunds
}
// validate the input strings
if err := tx.ValidateStrings(); err != nil {
log.Info(err.Error())
return types.ErrTxInvalidString
}
value := tx.Input.Amount - tx.Fee
// let's say cost of a name for one block is len(data) + 32
costPerBlock := types.NameCostPerBlock * types.NameCostPerByte * tx.BaseEntryCost()
expiresIn := int(value / costPerBlock)
lastBlockHeight := _s.LastBlockHeight
log.Info("New NameTx", "value", value, "costPerBlock", costPerBlock, "expiresIn", expiresIn, "lastBlock", lastBlockHeight)
// check if the name exists
entry := blockCache.GetNameRegEntry(tx.Name)
if entry != nil {
var expired bool
// if the entry already exists, and hasn't expired, we must be owner
if entry.Expires > lastBlockHeight {
// ensure we are owner
if bytes.Compare(entry.Owner, tx.Input.Address) != 0 {
log.Info(Fmt("Sender %X is trying to update a name (%s) for which he is not owner", tx.Input.Address, tx.Name))
return types.ErrTxPermissionDenied
}
} else {
expired = true
}
// no value and empty data means delete the entry
if value == 0 && len(tx.Data) == 0 {
// maybe we reward you for telling us we can delete this crap
// (owners if not expired, anyone if expired)
log.Info("Removing namereg entry", "name", entry.Name)
blockCache.RemoveNameRegEntry(entry.Name)
} else {
// update the entry by bumping the expiry
// and changing the data
if expired {
if expiresIn < types.MinNameRegistrationPeriod {
return errors.New(Fmt("Names must be registered for at least %d blocks", types.MinNameRegistrationPeriod))
}
entry.Expires = lastBlockHeight + expiresIn
entry.Owner = tx.Input.Address
log.Info("An old namereg entry has expired and been reclaimed", "name", entry.Name, "expiresIn", expiresIn, "owner", entry.Owner)
} else {
// since the size of the data may have changed
// we use the total amount of "credit"
oldCredit := int64(entry.Expires-lastBlockHeight) * types.BaseEntryCost(entry.Name, entry.Data)
credit := oldCredit + value
expiresIn = int(credit / costPerBlock)
if expiresIn < types.MinNameRegistrationPeriod {
return errors.New(Fmt("Names must be registered for at least %d blocks", types.MinNameRegistrationPeriod))
}
entry.Expires = lastBlockHeight + expiresIn
log.Info("Updated namereg entry", "name", entry.Name, "expiresIn", expiresIn, "oldCredit", oldCredit, "value", value, "credit", credit)
}
entry.Data = tx.Data
blockCache.UpdateNameRegEntry(entry)
}
} else {
if expiresIn < types.MinNameRegistrationPeriod {
return errors.New(Fmt("Names must be registered for at least %d blocks", types.MinNameRegistrationPeriod))
}
// entry does not exist, so create it
entry = &types.NameRegEntry{
Name: tx.Name,
Owner: tx.Input.Address,
Data: tx.Data,
Expires: lastBlockHeight + expiresIn,
}
log.Info("Creating namereg entry", "name", entry.Name, "expiresIn", expiresIn)
blockCache.UpdateNameRegEntry(entry)
}
// TODO: something with the value sent?
// Good!
inAcc.Sequence += 1
inAcc.Balance -= value
blockCache.UpdateAccount(inAcc)
// TODO: maybe we want to take funds on error and allow txs in that don't do anythingi?
if evc != nil {
evc.FireEvent(types.EventStringAccInput(tx.Input.Address), types.EventDataTx{tx, nil, ""})
evc.FireEvent(types.EventStringNameReg(tx.Name), types.EventDataTx{tx, nil, ""})
}
return nil
case *types.BondTx:
valInfo := blockCache.State().GetValidatorInfo(tx.PubKey.Address())
if valInfo != nil {
// TODO: In the future, check that the validator wasn't destroyed,
// add funds, merge UnbondTo outputs, and unbond validator.
return errors.New("Adding coins to existing validators not yet supported")
}
accounts, err := getInputs(blockCache, tx.Inputs)
if err != nil {
return err
}
// add outputs to accounts map
// if any outputs don't exist, all inputs must have CreateAccount perm
// though outputs aren't created until unbonding/release time
canCreate := hasCreateAccountPermission(blockCache, accounts)
for _, out := range tx.UnbondTo {
acc := blockCache.GetAccount(out.Address)
if acc == nil && !canCreate {
return fmt.Errorf("At least one input does not have permission to create accounts")
}
}
bondAcc := blockCache.GetAccount(tx.PubKey.Address())
if !hasBondPermission(blockCache, bondAcc) {
return fmt.Errorf("The bonder does not have permission to bond")
}
if !hasBondOrSendPermission(blockCache, accounts) {
return fmt.Errorf("At least one input lacks permission to bond")
}
signBytes := acm.SignBytes(_s.ChainID, tx)
inTotal, err := validateInputs(accounts, signBytes, tx.Inputs)
if err != nil {
return err
}
if !tx.PubKey.VerifyBytes(signBytes, tx.Signature) {
return types.ErrTxInvalidSignature
}
outTotal, err := validateOutputs(tx.UnbondTo)
if err != nil {
return err
}
if outTotal > inTotal {
return types.ErrTxInsufficientFunds
}
fee := inTotal - outTotal
fees += fee
// Good! Adjust accounts
adjustByInputs(accounts, tx.Inputs)
for _, acc := range accounts {
blockCache.UpdateAccount(acc)
}
// Add ValidatorInfo
_s.SetValidatorInfo(&types.ValidatorInfo{
Address: tx.PubKey.Address(),
PubKey: tx.PubKey,
UnbondTo: tx.UnbondTo,
FirstBondHeight: _s.LastBlockHeight + 1,
FirstBondAmount: outTotal,
})
// Add Validator
added := _s.BondedValidators.Add(&types.Validator{
Address: tx.PubKey.Address(),
PubKey: tx.PubKey,
BondHeight: _s.LastBlockHeight + 1,
VotingPower: outTotal,
Accum: 0,
})
if !added {
PanicCrisis("Failed to add validator")
}
if evc != nil {
// TODO: fire for all inputs
evc.FireEvent(types.EventStringBond(), types.EventDataTx{tx, nil, ""})
}
return nil
case *types.UnbondTx:
// The validator must be active
_, val := _s.BondedValidators.GetByAddress(tx.Address)
if val == nil {
return types.ErrTxInvalidAddress
}
// Verify the signature
signBytes := acm.SignBytes(_s.ChainID, tx)
if !val.PubKey.VerifyBytes(signBytes, tx.Signature) {
return types.ErrTxInvalidSignature
}
// tx.Height must be greater than val.LastCommitHeight
if tx.Height <= val.LastCommitHeight {
return errors.New("Invalid unbond height")
}
// Good!
_s.unbondValidator(val)
if evc != nil {
evc.FireEvent(types.EventStringUnbond(), types.EventDataTx{tx, nil, ""})
}
return nil
case *types.RebondTx:
// The validator must be inactive
_, val := _s.UnbondingValidators.GetByAddress(tx.Address)
if val == nil {
return types.ErrTxInvalidAddress
}
// Verify the signature
signBytes := acm.SignBytes(_s.ChainID, tx)
if !val.PubKey.VerifyBytes(signBytes, tx.Signature) {
return types.ErrTxInvalidSignature
}
// tx.Height must be in a suitable range
minRebondHeight := _s.LastBlockHeight - (validatorTimeoutBlocks / 2)
maxRebondHeight := _s.LastBlockHeight + 2
if !((minRebondHeight <= tx.Height) && (tx.Height <= maxRebondHeight)) {
return errors.New(Fmt("Rebond height not in range. Expected %v <= %v <= %v",
minRebondHeight, tx.Height, maxRebondHeight))
}
// Good!
_s.rebondValidator(val)
if evc != nil {
evc.FireEvent(types.EventStringRebond(), types.EventDataTx{tx, nil, ""})
}
return nil
case *types.DupeoutTx:
// Verify the signatures
_, accused := _s.BondedValidators.GetByAddress(tx.Address)
if accused == nil {
_, accused = _s.UnbondingValidators.GetByAddress(tx.Address)
if accused == nil {
return types.ErrTxInvalidAddress
}
}
voteASignBytes := acm.SignBytes(_s.ChainID, &tx.VoteA)
voteBSignBytes := acm.SignBytes(_s.ChainID, &tx.VoteB)
if !accused.PubKey.VerifyBytes(voteASignBytes, tx.VoteA.Signature) ||
!accused.PubKey.VerifyBytes(voteBSignBytes, tx.VoteB.Signature) {
return types.ErrTxInvalidSignature
}
// Verify equivocation
// TODO: in the future, just require one vote from a previous height that
// doesn't exist on this chain.
if tx.VoteA.Height != tx.VoteB.Height {
return errors.New("DupeoutTx heights don't match")
}
if tx.VoteA.Round != tx.VoteB.Round {
return errors.New("DupeoutTx rounds don't match")
}
if tx.VoteA.Type != tx.VoteB.Type {
return errors.New("DupeoutTx types don't match")
}
if bytes.Equal(tx.VoteA.BlockHash, tx.VoteB.BlockHash) {
return errors.New("DupeoutTx blockhashes shouldn't match")
}
// Good! (Bad validator!)
_s.destroyValidator(accused)
if evc != nil {
evc.FireEvent(types.EventStringDupeout(), types.EventDataTx{tx, nil, ""})
}
return nil
case *types.PermissionsTx:
var inAcc *acm.Account
// Validate input
inAcc = blockCache.GetAccount(tx.Input.Address)
if inAcc == nil {
log.Debug(Fmt("Can't find in account %X", tx.Input.Address))
return types.ErrTxInvalidAddress
}
permFlag := tx.PermArgs.PermFlag()
// check permission
if !HasPermission(blockCache, inAcc, permFlag) {
return fmt.Errorf("Account %X does not have moderator permission %s (%b)", tx.Input.Address, ptypes.PermFlagToString(permFlag), permFlag)
}
// pubKey should be present in either "inAcc" or "tx.Input"
if err := checkInputPubKey(inAcc, tx.Input); err != nil {
log.Debug(Fmt("Can't find pubkey for %X", tx.Input.Address))
return err
}
signBytes := acm.SignBytes(_s.ChainID, tx)
err := validateInput(inAcc, signBytes, tx.Input)
if err != nil {
log.Debug(Fmt("validateInput failed on %X: %v", tx.Input.Address, err))
return err
}
value := tx.Input.Amount
log.Debug("New PermissionsTx", "function", ptypes.PermFlagToString(permFlag), "args", tx.PermArgs)
var permAcc *acm.Account
switch args := tx.PermArgs.(type) {
case *ptypes.HasBaseArgs:
// this one doesn't make sense from txs
return fmt.Errorf("HasBase is for contracts, not humans. Just look at the blockchain")
case *ptypes.SetBaseArgs:
if permAcc = blockCache.GetAccount(args.Address); permAcc == nil {
return fmt.Errorf("Trying to update permissions for unknown account %X", args.Address)
}
err = permAcc.Permissions.Base.Set(args.Permission, args.Value)
case *ptypes.UnsetBaseArgs:
if permAcc = blockCache.GetAccount(args.Address); permAcc == nil {
return fmt.Errorf("Trying to update permissions for unknown account %X", args.Address)
}
err = permAcc.Permissions.Base.Unset(args.Permission)
case *ptypes.SetGlobalArgs:
if permAcc = blockCache.GetAccount(ptypes.GlobalPermissionsAddress); permAcc == nil {
PanicSanity("can't find global permissions account")
}
err = permAcc.Permissions.Base.Set(args.Permission, args.Value)
case *ptypes.HasRoleArgs:
return fmt.Errorf("HasRole is for contracts, not humans. Just look at the blockchain")
case *ptypes.AddRoleArgs:
if permAcc = blockCache.GetAccount(args.Address); permAcc == nil {
return fmt.Errorf("Trying to update roles for unknown account %X", args.Address)
}
if !permAcc.Permissions.AddRole(args.Role) {
return fmt.Errorf("Role (%s) already exists for account %X", args.Role, args.Address)
}
case *ptypes.RmRoleArgs:
if permAcc = blockCache.GetAccount(args.Address); permAcc == nil {
return fmt.Errorf("Trying to update roles for unknown account %X", args.Address)
}
if !permAcc.Permissions.RmRole(args.Role) {
return fmt.Errorf("Role (%s) does not exist for account %X", args.Role, args.Address)
}
default:
PanicSanity(Fmt("invalid permission function: %s", ptypes.PermFlagToString(permFlag)))
}
// TODO: maybe we want to take funds on error and allow txs in that don't do anythingi?
if err != nil {
return err
}
// Good!
inAcc.Sequence += 1
inAcc.Balance -= value
blockCache.UpdateAccount(inAcc)
if permAcc != nil {
blockCache.UpdateAccount(permAcc)
}
if evc != nil {
evc.FireEvent(types.EventStringAccInput(tx.Input.Address), types.EventDataTx{tx, nil, ""})
evc.FireEvent(types.EventStringPermissions(ptypes.PermFlagToString(permFlag)), types.EventDataTx{tx, nil, ""})
}
return nil
default:
// binary decoding should not let this happen
PanicSanity("Unknown Tx type")
return nil
}
}