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tendermint
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tendermint/vm/vm.go

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package vm
import (
"bytes"
"errors"
"fmt"
"math/big"
. "github.com/tendermint/tendermint/common"
"github.com/tendermint/tendermint/events"
ptypes "github.com/tendermint/tendermint/permission/types"
"github.com/tendermint/tendermint/types"
"github.com/tendermint/tendermint/vm/sha3"
)
var (
ErrUnknownAddress = errors.New("Unknown address")
ErrInsufficientBalance = errors.New("Insufficient balance")
ErrInvalidJumpDest = errors.New("Invalid jump dest")
ErrInsufficientGas = errors.New("Insuffient gas")
ErrMemoryOutOfBounds = errors.New("Memory out of bounds")
ErrCodeOutOfBounds = errors.New("Code out of bounds")
ErrInputOutOfBounds = errors.New("Input out of bounds")
ErrCallStackOverflow = errors.New("Call stack overflow")
ErrCallStackUnderflow = errors.New("Call stack underflow")
ErrDataStackOverflow = errors.New("Data stack overflow")
ErrDataStackUnderflow = errors.New("Data stack underflow")
ErrInvalidContract = errors.New("Invalid contract")
)
type ErrPermission struct {
typ string
}
func (err ErrPermission) Error() string {
return fmt.Sprintf("Contract does not have permission to %s", err.typ)
}
const (
dataStackCapacity = 1024
callStackCapacity = 100 // TODO ensure usage.
memoryCapacity = 1024 * 1024 // 1 MB
)
type Debug bool
var dbg Debug
func SetDebug(d bool) {
dbg = Debug(d)
}
func (d Debug) Printf(s string, a ...interface{}) {
if d {
fmt.Printf(s, a...)
}
}
type VM struct {
appState AppState
params Params
origin Word256
txid []byte
callDepth int
evc events.Fireable
}
func NewVM(appState AppState, params Params, origin Word256, txid []byte) *VM {
return &VM{
appState: appState,
params: params,
origin: origin,
callDepth: 0,
txid: txid,
}
}
// satisfies events.Eventable
func (vm *VM) SetFireable(evc events.Fireable) {
vm.evc = evc
}
// CONTRACT: it is the duty of the contract writer to call known permissions
// we do not convey if a permission is not set
// (unlike in state/execution, where we guarantee HasPermission is called
// on known permissions and panics else)
// If the perm is not defined in the acc nor set by default in GlobalPermissions,
// prints a log warning and returns false.
func HasPermission(appState AppState, acc *Account, perm ptypes.PermFlag) bool {
v, err := acc.Permissions.Base.Get(perm)
if _, ok := err.(ptypes.ErrValueNotSet); ok {
if appState == nil {
log.Warn(Fmt("\n\n***** Unknown permission %b! ********\n\n", perm))
return false
}
return HasPermission(nil, appState.GetAccount(ptypes.GlobalPermissionsAddress256), perm)
}
return v
}
func (vm *VM) fireCallEvent(exception *string, output *[]byte, caller, callee *Account, input []byte, value int64, gas *int64) {
// fire the post call event (including exception if applicable)
if vm.evc != nil {
vm.evc.FireEvent(types.EventStringAccCall(callee.Address.Postfix(20)), types.EventDataCall{
&types.CallData{caller.Address.Postfix(20), callee.Address.Postfix(20), input, value, *gas},
vm.origin.Postfix(20),
vm.txid,
*output,
*exception,
})
}
}
// CONTRACT appState is aware of caller and callee, so we can just mutate them.
// CONTRACT code and input are not mutated.
// CONTRACT returned 'ret' is a new compact slice.
// value: To be transferred from caller to callee. Refunded upon error.
// gas: Available gas. No refunds for gas.
// code: May be nil, since the CALL opcode may be used to send value from contracts to accounts
func (vm *VM) Call(caller, callee *Account, code, input []byte, value int64, gas *int64) (output []byte, err error) {
exception := new(string)
// fire the post call event (including exception if applicable)
defer vm.fireCallEvent(exception, &output, caller, callee, input, value, gas)
if err = transfer(caller, callee, value); err != nil {
*exception = err.Error()
return
}
if len(code) > 0 {
vm.callDepth += 1
output, err = vm.call(caller, callee, code, input, value, gas)
vm.callDepth -= 1
if err != nil {
*exception = err.Error()
err := transfer(callee, caller, value)
if err != nil {
// data has been corrupted in ram
PanicCrisis("Could not return value to caller")
}
}
}
return
}
// Try to deduct gasToUse from gasLeft. If ok return false, otherwise
// set err and return true.
func useGasNegative(gasLeft *int64, gasToUse int64, err *error) bool {
if *gasLeft >= gasToUse {
*gasLeft -= gasToUse
return false
} else if *err == nil {
*err = ErrInsufficientGas
}
return true
}
// Just like Call() but does not transfer 'value' or modify the callDepth.
func (vm *VM) call(caller, callee *Account, code, input []byte, value int64, gas *int64) (output []byte, err error) {
dbg.Printf("(%d) (%X) %X (code=%d) gas: %v (d) %X\n", vm.callDepth, caller.Address[:4], callee.Address, len(callee.Code), *gas, input)
var (
pc int64 = 0
stack = NewStack(dataStackCapacity, gas, &err)
memory = make([]byte, memoryCapacity)
)
for {
// Use BaseOp gas.
if useGasNegative(gas, GasBaseOp, &err) {
return nil, err
}
var op = codeGetOp(code, pc)
dbg.Printf("(pc) %-3d (op) %-14s (st) %-4d ", pc, op.String(), stack.Len())
switch op {
case ADD: // 0x01
x, y := stack.Pop(), stack.Pop()
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
sum := new(big.Int).Add(xb, yb)
res := LeftPadWord256(U256(sum).Bytes())
stack.Push(res)
dbg.Printf(" %v + %v = %v (%X)\n", xb, yb, sum, res)
case MUL: // 0x02
x, y := stack.Pop(), stack.Pop()
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
prod := new(big.Int).Mul(xb, yb)
res := LeftPadWord256(U256(prod).Bytes())
stack.Push(res)
dbg.Printf(" %v * %v = %v (%X)\n", xb, yb, prod, res)
case SUB: // 0x03
x, y := stack.Pop(), stack.Pop()
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
diff := new(big.Int).Sub(xb, yb)
res := LeftPadWord256(U256(diff).Bytes())
stack.Push(res)
dbg.Printf(" %v - %v = %v (%X)\n", xb, yb, diff, res)
case DIV: // 0x04
x, y := stack.Pop(), stack.Pop()
if y.IsZero() {
stack.Push(Zero256)
dbg.Printf(" %x / %x = %v\n", x, y, 0)
} else {
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
div := new(big.Int).Div(xb, yb)
res := LeftPadWord256(U256(div).Bytes())
stack.Push(res)
dbg.Printf(" %v / %v = %v (%X)\n", xb, yb, div, res)
}
case SDIV: // 0x05
x, y := stack.Pop(), stack.Pop()
if y.IsZero() {
stack.Push(Zero256)
dbg.Printf(" %x / %x = %v\n", x, y, 0)
} else {
xb := S256(new(big.Int).SetBytes(x[:]))
yb := S256(new(big.Int).SetBytes(y[:]))
div := new(big.Int).Div(xb, yb)
res := LeftPadWord256(U256(div).Bytes())
stack.Push(res)
dbg.Printf(" %v / %v = %v (%X)\n", xb, yb, div, res)
}
case MOD: // 0x06
x, y := stack.Pop(), stack.Pop()
if y.IsZero() {
stack.Push(Zero256)
dbg.Printf(" %v %% %v = %v\n", x, y, 0)
} else {
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
mod := new(big.Int).Mod(xb, yb)
res := LeftPadWord256(U256(mod).Bytes())
stack.Push(res)
dbg.Printf(" %v %% %v = %v (%X)\n", xb, yb, mod, res)
}
case SMOD: // 0x07
x, y := stack.Pop(), stack.Pop()
if y.IsZero() {
stack.Push(Zero256)
dbg.Printf(" %v %% %v = %v\n", x, y, 0)
} else {
xb := S256(new(big.Int).SetBytes(x[:]))
yb := S256(new(big.Int).SetBytes(y[:]))
mod := new(big.Int).Mod(xb, yb)
res := LeftPadWord256(U256(mod).Bytes())
stack.Push(res)
dbg.Printf(" %v %% %v = %v (%X)\n", xb, yb, mod, res)
}
case ADDMOD: // 0x08
x, y, z := stack.Pop(), stack.Pop(), stack.Pop()
if z.IsZero() {
stack.Push(Zero256)
dbg.Printf(" %v %% %v = %v\n", x, y, 0)
} else {
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
zb := new(big.Int).SetBytes(z[:])
add := new(big.Int).Add(xb, yb)
mod := new(big.Int).Mod(add, zb)
res := LeftPadWord256(U256(mod).Bytes())
stack.Push(res)
dbg.Printf(" %v + %v %% %v = %v (%X)\n",
xb, yb, zb, mod, res)
}
case MULMOD: // 0x09
x, y, z := stack.Pop(), stack.Pop(), stack.Pop()
if z.IsZero() {
stack.Push(Zero256)
dbg.Printf(" %v %% %v = %v\n", x, y, 0)
} else {
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
zb := new(big.Int).SetBytes(z[:])
mul := new(big.Int).Mul(xb, yb)
mod := new(big.Int).Mod(mul, zb)
res := LeftPadWord256(U256(mod).Bytes())
stack.Push(res)
dbg.Printf(" %v * %v %% %v = %v (%X)\n",
xb, yb, zb, mod, res)
}
case EXP: // 0x0A
x, y := stack.Pop(), stack.Pop()
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
pow := new(big.Int).Exp(xb, yb, big.NewInt(0))
res := LeftPadWord256(U256(pow).Bytes())
stack.Push(res)
dbg.Printf(" %v ** %v = %v (%X)\n", xb, yb, pow, res)
case SIGNEXTEND: // 0x0B
back := stack.Pop()
backb := new(big.Int).SetBytes(back[:])
if backb.Cmp(big.NewInt(31)) < 0 {
bit := uint(backb.Uint64()*8 + 7)
num := stack.Pop()
numb := new(big.Int).SetBytes(num[:])
mask := new(big.Int).Lsh(big.NewInt(1), bit)
mask.Sub(mask, big.NewInt(1))
if numb.Bit(int(bit)) == 1 {
numb.Or(numb, mask.Not(mask))
} else {
numb.Add(numb, mask)
}
res := LeftPadWord256(U256(numb).Bytes())
dbg.Printf(" = %v (%X)", numb, res)
stack.Push(res)
}
case LT: // 0x10
x, y := stack.Pop(), stack.Pop()
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
if xb.Cmp(yb) < 0 {
stack.Push64(1)
dbg.Printf(" %v < %v = %v\n", xb, yb, 1)
} else {
stack.Push(Zero256)
dbg.Printf(" %v < %v = %v\n", xb, yb, 0)
}
case GT: // 0x11
x, y := stack.Pop(), stack.Pop()
xb := new(big.Int).SetBytes(x[:])
yb := new(big.Int).SetBytes(y[:])
if xb.Cmp(yb) > 0 {
stack.Push64(1)
dbg.Printf(" %v > %v = %v\n", xb, yb, 1)
} else {
stack.Push(Zero256)
dbg.Printf(" %v > %v = %v\n", xb, yb, 0)
}
case SLT: // 0x12
x, y := stack.Pop(), stack.Pop()
xb := S256(new(big.Int).SetBytes(x[:]))
yb := S256(new(big.Int).SetBytes(y[:]))
if xb.Cmp(yb) < 0 {
stack.Push64(1)
dbg.Printf(" %v < %v = %v\n", xb, yb, 1)
} else {
stack.Push(Zero256)
dbg.Printf(" %v < %v = %v\n", xb, yb, 0)
}
case SGT: // 0x13
x, y := stack.Pop(), stack.Pop()
xb := S256(new(big.Int).SetBytes(x[:]))
yb := S256(new(big.Int).SetBytes(y[:]))
if xb.Cmp(yb) > 0 {
stack.Push64(1)
dbg.Printf(" %v > %v = %v\n", xb, yb, 1)
} else {
stack.Push(Zero256)
dbg.Printf(" %v > %v = %v\n", xb, yb, 0)
}
case EQ: // 0x14
x, y := stack.Pop(), stack.Pop()
if bytes.Equal(x[:], y[:]) {
stack.Push64(1)
dbg.Printf(" %X == %X = %v\n", x, y, 1)
} else {
stack.Push(Zero256)
dbg.Printf(" %X == %X = %v\n", x, y, 0)
}
case ISZERO: // 0x15
x := stack.Pop()
if x.IsZero() {
stack.Push64(1)
dbg.Printf(" %v == 0 = %v\n", x, 1)
} else {
stack.Push(Zero256)
dbg.Printf(" %v == 0 = %v\n", x, 0)
}
case AND: // 0x16
x, y := stack.Pop(), stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = x[i] & y[i]
}
stack.Push(z)
dbg.Printf(" %X & %X = %X\n", x, y, z)
case OR: // 0x17
x, y := stack.Pop(), stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = x[i] | y[i]
}
stack.Push(z)
dbg.Printf(" %X | %X = %X\n", x, y, z)
case XOR: // 0x18
x, y := stack.Pop(), stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = x[i] ^ y[i]
}
stack.Push(z)
dbg.Printf(" %X ^ %X = %X\n", x, y, z)
case NOT: // 0x19
x := stack.Pop()
z := [32]byte{}
for i := 0; i < 32; i++ {
z[i] = ^x[i]
}
stack.Push(z)
dbg.Printf(" !%X = %X\n", x, z)
case BYTE: // 0x1A
idx, val := stack.Pop64(), stack.Pop()
res := byte(0)
if idx < 32 {
res = val[idx]
}
stack.Push64(int64(res))
dbg.Printf(" => 0x%X\n", res)
case SHA3: // 0x20
if useGasNegative(gas, GasSha3, &err) {
return nil, err
}
offset, size := stack.Pop64(), stack.Pop64()
data, ok := subslice(memory, offset, size)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
data = sha3.Sha3(data)
stack.PushBytes(data)
dbg.Printf(" => (%v) %X\n", size, data)
case ADDRESS: // 0x30
stack.Push(callee.Address)
dbg.Printf(" => %X\n", callee.Address)
case BALANCE: // 0x31
addr := stack.Pop()
if useGasNegative(gas, GasGetAccount, &err) {
return nil, err
}
acc := vm.appState.GetAccount(addr)
if acc == nil {
return nil, firstErr(err, ErrUnknownAddress)
}
balance := acc.Balance
stack.Push64(balance)
dbg.Printf(" => %v (%X)\n", balance, addr)
case ORIGIN: // 0x32
stack.Push(vm.origin)
dbg.Printf(" => %X\n", vm.origin)
case CALLER: // 0x33
stack.Push(caller.Address)
dbg.Printf(" => %X\n", caller.Address)
case CALLVALUE: // 0x34
stack.Push64(value)
dbg.Printf(" => %v\n", value)
case CALLDATALOAD: // 0x35
offset := stack.Pop64()
data, ok := subslice(input, offset, 32)
if !ok {
return nil, firstErr(err, ErrInputOutOfBounds)
}
res := LeftPadWord256(data)
stack.Push(res)
dbg.Printf(" => 0x%X\n", res)
case CALLDATASIZE: // 0x36
stack.Push64(int64(len(input)))
dbg.Printf(" => %d\n", len(input))
case CALLDATACOPY: // 0x37
memOff := stack.Pop64()
inputOff := stack.Pop64()
length := stack.Pop64()
data, ok := subslice(input, inputOff, length)
if !ok {
return nil, firstErr(err, ErrInputOutOfBounds)
}
dest, ok := subslice(memory, memOff, length)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
copy(dest, data)
dbg.Printf(" => [%v, %v, %v] %X\n", memOff, inputOff, length, data)
case CODESIZE: // 0x38
l := int64(len(code))
stack.Push64(l)
dbg.Printf(" => %d\n", l)
case CODECOPY: // 0x39
memOff := stack.Pop64()
codeOff := stack.Pop64()
length := stack.Pop64()
data, ok := subslice(code, codeOff, length)
if !ok {
return nil, firstErr(err, ErrCodeOutOfBounds)
}
dest, ok := subslice(memory, memOff, length)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
copy(dest, data)
dbg.Printf(" => [%v, %v, %v] %X\n", memOff, codeOff, length, data)
case GASPRICE_DEPRECATED: // 0x3A
stack.Push(Zero256)
dbg.Printf(" => %X (GASPRICE IS DEPRECATED)\n")
case EXTCODESIZE: // 0x3B
addr := stack.Pop()
if useGasNegative(gas, GasGetAccount, &err) {
return nil, err
}
acc := vm.appState.GetAccount(addr)
if acc == nil {
return nil, firstErr(err, ErrUnknownAddress)
}
code := acc.Code
l := int64(len(code))
stack.Push64(l)
dbg.Printf(" => %d\n", l)
case EXTCODECOPY: // 0x3C
addr := stack.Pop()
if useGasNegative(gas, GasGetAccount, &err) {
return nil, err
}
acc := vm.appState.GetAccount(addr)
if acc == nil {
return nil, firstErr(err, ErrUnknownAddress)
}
code := acc.Code
memOff := stack.Pop64()
codeOff := stack.Pop64()
length := stack.Pop64()
data, ok := subslice(code, codeOff, length)
if !ok {
return nil, firstErr(err, ErrCodeOutOfBounds)
}
dest, ok := subslice(memory, memOff, length)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
copy(dest, data)
dbg.Printf(" => [%v, %v, %v] %X\n", memOff, codeOff, length, data)
case BLOCKHASH: // 0x40
stack.Push(Zero256)
dbg.Printf(" => 0x%X (NOT SUPPORTED)\n", stack.Peek().Bytes())
case COINBASE: // 0x41
stack.Push(Zero256)
dbg.Printf(" => 0x%X (NOT SUPPORTED)\n", stack.Peek().Bytes())
case TIMESTAMP: // 0x42
time := vm.params.BlockTime
stack.Push64(int64(time))
dbg.Printf(" => 0x%X\n", time)
case BLOCKHEIGHT: // 0x43
number := int64(vm.params.BlockHeight)
stack.Push64(number)
dbg.Printf(" => 0x%X\n", number)
case GASLIMIT: // 0x45
stack.Push64(vm.params.GasLimit)
dbg.Printf(" => %v\n", vm.params.GasLimit)
case POP: // 0x50
popped := stack.Pop()
dbg.Printf(" => 0x%X\n", popped)
case MLOAD: // 0x51
offset := stack.Pop64()
data, ok := subslice(memory, offset, 32)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
stack.Push(LeftPadWord256(data))
dbg.Printf(" => 0x%X\n", data)
case MSTORE: // 0x52
offset, data := stack.Pop64(), stack.Pop()
dest, ok := subslice(memory, offset, 32)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
copy(dest, data[:])
dbg.Printf(" => 0x%X\n", data)
case MSTORE8: // 0x53
offset, val := stack.Pop64(), byte(stack.Pop64()&0xFF)
if len(memory) <= int(offset) {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
memory[offset] = val
dbg.Printf(" => [%v] 0x%X\n", offset, val)
case SLOAD: // 0x54
loc := stack.Pop()
data := vm.appState.GetStorage(callee.Address, loc)
stack.Push(data)
dbg.Printf(" {0x%X : 0x%X}\n", loc, data)
case SSTORE: // 0x55
loc, data := stack.Pop(), stack.Pop()
if useGasNegative(gas, GasStorageUpdate, &err) {
return nil, err
}
vm.appState.SetStorage(callee.Address, loc, data)
dbg.Printf(" {0x%X : 0x%X}\n", loc, data)
case JUMP: // 0x56
err = jump(code, stack.Pop64(), &pc)
continue
case JUMPI: // 0x57
pos, cond := stack.Pop64(), stack.Pop()
if !cond.IsZero() {
err = jump(code, pos, &pc)
continue
}
dbg.Printf(" ~> false\n")
case PC: // 0x58
stack.Push64(pc)
case MSIZE: // 0x59
stack.Push64(int64(len(memory)))
case GAS: // 0x5A
stack.Push64(*gas)
dbg.Printf(" => %X\n", *gas)
case JUMPDEST: // 0x5B
dbg.Printf("\n")
// Do nothing
case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
a := int64(op - PUSH1 + 1)
codeSegment, ok := subslice(code, pc+1, a)
if !ok {
return nil, firstErr(err, ErrCodeOutOfBounds)
}
res := LeftPadWord256(codeSegment)
stack.Push(res)
pc += a
dbg.Printf(" => 0x%X\n", res)
//stack.Print(10)
case DUP1, DUP2, DUP3, DUP4, DUP5, DUP6, DUP7, DUP8, DUP9, DUP10, DUP11, DUP12, DUP13, DUP14, DUP15, DUP16:
n := int(op - DUP1 + 1)
stack.Dup(n)
dbg.Printf(" => [%d] 0x%X\n", n, stack.Peek().Bytes())
case SWAP1, SWAP2, SWAP3, SWAP4, SWAP5, SWAP6, SWAP7, SWAP8, SWAP9, SWAP10, SWAP11, SWAP12, SWAP13, SWAP14, SWAP15, SWAP16:
n := int(op - SWAP1 + 2)
stack.Swap(n)
dbg.Printf(" => [%d] %X\n", n, stack.Peek())
//stack.Print(10)
case LOG0, LOG1, LOG2, LOG3, LOG4:
n := int(op - LOG0)
topics := make([]Word256, n)
offset, size := stack.Pop64(), stack.Pop64()
for i := 0; i < n; i++ {
topics[i] = stack.Pop()
}
data, ok := subslice(memory, offset, size)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
data = copyslice(data)
if vm.evc != nil {
eventID := types.EventStringLogEvent(callee.Address.Postfix(20))
fmt.Printf("eventID: %s\n", eventID)
log := types.EventDataLog{
callee.Address,
topics,
data,
vm.params.BlockHeight,
}
vm.evc.FireEvent(eventID, log)
}
dbg.Printf(" => T:%X D:%X\n", topics, data)
case CREATE: // 0xF0
if !HasPermission(vm.appState, callee, ptypes.CreateContract) {
return nil, ErrPermission{"create_contract"}
}
contractValue := stack.Pop64()
offset, size := stack.Pop64(), stack.Pop64()
input, ok := subslice(memory, offset, size)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
// Check balance
if callee.Balance < contractValue {
return nil, firstErr(err, ErrInsufficientBalance)
}
// TODO charge for gas to create account _ the code length * GasCreateByte
newAccount := vm.appState.CreateAccount(callee)
// Run the input to get the contract code.
// NOTE: no need to copy 'input' as per Call contract.
ret, err_ := vm.Call(callee, newAccount, input, input, contractValue, gas)
if err_ != nil {
stack.Push(Zero256)
} else {
newAccount.Code = ret // Set the code (ret need not be copied as per Call contract)
stack.Push(newAccount.Address)
}
case CALL, CALLCODE: // 0xF1, 0xF2
if !HasPermission(vm.appState, callee, ptypes.Call) {
return nil, ErrPermission{"call"}
}
gasLimit := stack.Pop64()
addr, value := stack.Pop(), stack.Pop64()
inOffset, inSize := stack.Pop64(), stack.Pop64() // inputs
retOffset, retSize := stack.Pop64(), stack.Pop64() // outputs
dbg.Printf(" => %X\n", addr)
// Get the arguments from the memory
args, ok := subslice(memory, inOffset, inSize)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
args = copyslice(args)
// Ensure that gasLimit is reasonable
if *gas < gasLimit {
return nil, firstErr(err, ErrInsufficientGas)
} else {
*gas -= gasLimit
// NOTE: we will return any used gas later.
}
// Begin execution
var ret []byte
var err error
if nativeContract := registeredNativeContracts[addr]; nativeContract != nil {
// Native contract
ret, err = nativeContract(vm.appState, callee, args, &gasLimit)
// for now we fire the Call event. maybe later we'll fire more particulars
var exception string
if err != nil {
exception = err.Error()
}
// NOTE: these fire call events and not particular events for eg name reg or permissions
vm.fireCallEvent(&exception, &ret, callee, &Account{Address: addr}, args, value, gas)
} else {
// EVM contract
if useGasNegative(gas, GasGetAccount, &err) {
return nil, err
}
acc := vm.appState.GetAccount(addr)
// since CALL is used also for sending funds,
// acc may not exist yet. This is an error for
// CALLCODE, but not for CALL, though I don't think
// ethereum actually cares
if op == CALLCODE {
if acc == nil {
return nil, firstErr(err, ErrUnknownAddress)
}
ret, err = vm.Call(callee, callee, acc.Code, args, value, gas)
} else {
if acc == nil {
// nil account means we're sending funds to a new account
if !HasPermission(vm.appState, caller, ptypes.CreateAccount) {
return nil, ErrPermission{"create_account"}
}
acc = &Account{Address: addr}
vm.appState.UpdateAccount(acc)
// send funds to new account
ret, err = vm.Call(callee, acc, acc.Code, args, value, gas)
} else {
// call standard contract
ret, err = vm.Call(callee, acc, acc.Code, args, value, gas)
}
}
}
// Push result
if err != nil {
dbg.Printf("error on call: %s\n", err.Error())
stack.Push(Zero256)
} else {
stack.Push(One256)
dest, ok := subslice(memory, retOffset, retSize)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
copy(dest, ret)
}
// Handle remaining gas.
*gas += gasLimit
dbg.Printf("resume %X (%v)\n", callee.Address, gas)
case RETURN: // 0xF3
offset, size := stack.Pop64(), stack.Pop64()
ret, ok := subslice(memory, offset, size)
if !ok {
return nil, firstErr(err, ErrMemoryOutOfBounds)
}
dbg.Printf(" => [%v, %v] (%d) 0x%X\n", offset, size, len(ret), ret)
output = copyslice(ret)
return output, nil
case SUICIDE: // 0xFF
addr := stack.Pop()
if useGasNegative(gas, GasGetAccount, &err) {
return nil, err
}
// TODO if the receiver is , then make it the fee. (?)
// TODO: create account if doesn't exist (no reason not to)
receiver := vm.appState.GetAccount(addr)
if receiver == nil {
return nil, firstErr(err, ErrUnknownAddress)
}
balance := callee.Balance
receiver.Balance += balance
vm.appState.UpdateAccount(receiver)
vm.appState.RemoveAccount(callee)
dbg.Printf(" => (%X) %v\n", addr[:4], balance)
fallthrough
case STOP: // 0x00
return nil, nil
default:
dbg.Printf("(pc) %-3v Invalid opcode %X\n", pc, op)
return nil, fmt.Errorf("Invalid opcode %X", op)
}
pc++
}
}
func subslice(data []byte, offset, length int64) (ret []byte, ok bool) {
size := int64(len(data))
if size < offset {
return nil, false
} else if size < offset+length {
ret, ok = data[offset:], true
ret = RightPadBytes(ret, 32)
} else {
ret, ok = data[offset:offset+length], true
}
return
}
func copyslice(src []byte) (dest []byte) {
dest = make([]byte, len(src))
copy(dest, src)
return dest
}
func rightMostBytes(data []byte, n int) []byte {
size := MinInt(len(data), n)
offset := len(data) - size
return data[offset:]
}
func codeGetOp(code []byte, n int64) OpCode {
if int64(len(code)) <= n {
return OpCode(0) // stop
} else {
return OpCode(code[n])
}
}
func jump(code []byte, to int64, pc *int64) (err error) {
dest := codeGetOp(code, to)
if dest != JUMPDEST {
dbg.Printf(" ~> %v invalid jump dest %v\n", to, dest)
return ErrInvalidJumpDest
}
dbg.Printf(" ~> %v\n", to)
*pc = to
return nil
}
func firstErr(errA, errB error) error {
if errA != nil {
return errA
} else {
return errB
}
}
func transfer(from, to *Account, amount int64) error {
if from.Balance < amount {
return ErrInsufficientBalance
} else {
from.Balance -= amount
to.Balance += amount
return nil
}
}
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