/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file VM.h
* @author Gav Wood <i@gavwood.com>
* @date 2014
*/
#pragma once
#include <unordered_map>
#include <libdevcore/Exceptions.h>
#include <libethcore/CommonEth.h>
#include <libevmface/Instruction.h>
#include <libdevcrypto/SHA3.h>
#include <libethcore/BlockInfo.h>
#include "FeeStructure.h"
#include "ExtVMFace.h"
namespace dev
{
namespace eth
{
struct VMException: virtual Exception {};
struct StepsDone: virtual VMException {};
struct BreakPointHit: virtual VMException {};
struct BadInstruction: virtual VMException {};
struct OutOfGas: virtual VMException {};
class StackTooSmall: public VMException { public: StackTooSmall(u256 _req, u256 _got): req(_req), got(_got) {} u256 req; u256 got; };
// Convert from a 256-bit integer stack/memory entry into a 160-bit Address hash.
// Currently we just pull out the right (low-order in BE) 160-bits.
inline Address asAddress(u256 _item)
{
return right160(h256(_item));
}
inline u256 fromAddress(Address _a)
{
return (u160)_a;
// h256 ret;
// memcpy(&ret, &_a, sizeof(_a));
// return ret;
}
/**
*/
class VM
{
public:
/// Construct VM object.
explicit VM(u256 _gas = 0) { reset(_gas); }
void reset(u256 _gas = 0);
template <class Ext>
bytesConstRef go(Ext& _ext, OnOpFunc const& _onOp = OnOpFunc(), uint64_t _steps = (uint64_t)-1);
void require(u256 _n) { if (m_stack.size() < _n) BOOST_THROW_EXCEPTION(StackTooSmall(_n, m_stack.size())); }
void requireMem(unsigned _n) { if (m_temp.size() < _n) { m_temp.resize(_n); } }
u256 gas() const { return m_gas; }
u256 curPC() const { return m_curPC; }
bytes const& memory() const { return m_temp; }
u256s const& stack() const { return m_stack; }
private:
u256 m_gas = 0;
u256 m_curPC = 0;
bytes m_temp;
u256s m_stack;
};
}
// INLINE:
template <class Ext> dev::bytesConstRef dev::eth::VM::go(Ext& _ext, OnOpFunc const& _onOp, uint64_t _steps)
{
auto memNeed = [](dev::u256 _offset, dev::u256 _size) { return _size ? _offset + _size : 0; };
u256 nextPC = m_curPC + 1;
auto osteps = _steps;
for (bool stopped = false; !stopped && _steps--; m_curPC = nextPC, nextPC = m_curPC + 1)
{
// INSTRUCTION...
Instruction inst = (Instruction)_ext.getCode(m_curPC);
// FEES...
bigint runGas = c_stepGas;
bigint newTempSize = m_temp.size();
switch (inst)
{
case Instruction::STOP:
runGas = 0;
break;
case Instruction::SUICIDE:
runGas = 0;
break;
case Instruction::SSTORE:
require(2);
if (!_ext.store(m_stack.back()) && m_stack[m_stack.size() - 2])
runGas = c_sstoreGas * 2;
else if (_ext.store(m_stack.back()) && !m_stack[m_stack.size() - 2])
runGas = 0;
else
runGas = c_sstoreGas;
break;
case Instruction::SLOAD:
runGas = c_sloadGas;
break;
// These all operate on memory and therefore potentially expand it:
case Instruction::MSTORE:
require(2);
newTempSize = m_stack.back() + 32;
break;
case Instruction::MSTORE8:
require(2);
newTempSize = m_stack.back() + 1;
break;
case Instruction::MLOAD:
require(1);
newTempSize = m_stack.back() + 32;
break;
case Instruction::RETURN:
require(2);
newTempSize = memNeed(m_stack.back(), m_stack[m_stack.size() - 2]);
break;
case Instruction::SHA3:
require(2);
runGas = c_sha3Gas;
newTempSize = memNeed(m_stack.back(), m_stack[m_stack.size() - 2]);
break;
case Instruction::CALLDATACOPY:
require(3);
newTempSize = memNeed(m_stack.back(), m_stack[m_stack.size() - 3]);
break;
case Instruction::CODECOPY:
require(3);
newTempSize = memNeed(m_stack.back(), m_stack[m_stack.size() - 3]);
break;
case Instruction::EXTCODECOPY:
require(4);
newTempSize = memNeed(m_stack[m_stack.size() - 2], m_stack[m_stack.size() - 4]);
break;
case Instruction::BALANCE:
runGas = c_balanceGas;
break;
case Instruction::CALL:
require(7);
runGas = c_callGas + m_stack[m_stack.size() - 1];
newTempSize = std::max(memNeed(m_stack[m_stack.size() - 6], m_stack[m_stack.size() - 7]), memNeed(m_stack[m_stack.size() - 4], m_stack[m_stack.size() - 5]));
break;
case Instruction::CALLSTATELESS:
require(7);
runGas = c_callGas + m_stack[m_stack.size() - 1];
newTempSize = std::max(memNeed(m_stack[m_stack.size() - 6], m_stack[m_stack.size() - 7]), memNeed(m_stack[m_stack.size() - 4], m_stack[m_stack.size() - 5]));
break;
case Instruction::POST:
require(5);
runGas = c_callGas + m_stack[m_stack.size() - 1];
newTempSize = memNeed(m_stack[m_stack.size() - 4], m_stack[m_stack.size() - 5]);
break;
case Instruction::CREATE:
{
require(3);
auto inOff = m_stack[m_stack.size() - 2];
auto inSize = m_stack[m_stack.size() - 3];
newTempSize = inOff + inSize;
runGas = c_createGas;
break;
}
default:
break;
}
newTempSize = (newTempSize + 31) / 32 * 32;
if (newTempSize > m_temp.size())
runGas += c_memoryGas * (newTempSize - m_temp.size()) / 32;
if (_onOp)
_onOp(osteps - _steps - 1, inst, newTempSize > m_temp.size() ? (newTempSize - m_temp.size()) / 32 : bigint(0), runGas, this, &_ext);
if (m_gas < runGas)
{
// Out of gas!
m_gas = 0;
BOOST_THROW_EXCEPTION(OutOfGas());
}
m_gas = (u256)((bigint)m_gas - runGas);
if (newTempSize > m_temp.size())
m_temp.resize((size_t)newTempSize);
// EXECUTE...
switch (inst)
{
case Instruction::ADD:
//pops two items and pushes S[-1] + S[-2] mod 2^256.
require(2);
m_stack[m_stack.size() - 2] += m_stack.back();
m_stack.pop_back();
break;
case Instruction::MUL:
//pops two items and pushes S[-1] * S[-2] mod 2^256.
require(2);
m_stack[m_stack.size() - 2] *= m_stack.back();
m_stack.pop_back();
break;
case Instruction::SUB:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() - m_stack[m_stack.size() - 2];
m_stack.pop_back();
break;
case Instruction::DIV:
require(2);
m_stack[m_stack.size() - 2] = m_stack[m_stack.size() - 2] ? m_stack.back() / m_stack[m_stack.size() - 2] : 0;
m_stack.pop_back();
break;
case Instruction::SDIV:
require(2);
m_stack[m_stack.size() - 2] = m_stack[m_stack.size() - 2] ? s2u(u2s(m_stack.back()) / u2s(m_stack[m_stack.size() - 2])) : 0;
m_stack.pop_back();
break;
case Instruction::MOD:
require(2);
m_stack[m_stack.size() - 2] = m_stack[m_stack.size() - 2] ? m_stack.back() % m_stack[m_stack.size() - 2] : 0;
m_stack.pop_back();
break;
case Instruction::SMOD:
require(2);
m_stack[m_stack.size() - 2] = m_stack[m_stack.size() - 2] ? s2u(u2s(m_stack.back()) % u2s(m_stack[m_stack.size() - 2])) : 0;
m_stack.pop_back();
break;
case Instruction::EXP:
{
require(2);
auto base = m_stack.back();
auto expon = m_stack[m_stack.size() - 2];
m_stack.pop_back();
m_stack.back() = (u256)boost::multiprecision::powm((bigint)base, (bigint)expon, bigint(2) << 256);
break;
}
case Instruction::NEG:
require(1);
m_stack.back() = ~(m_stack.back() - 1);
break;
case Instruction::LT:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() < m_stack[m_stack.size() - 2] ? 1 : 0;
m_stack.pop_back();
break;
case Instruction::GT:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() > m_stack[m_stack.size() - 2] ? 1 : 0;
m_stack.pop_back();
break;
case Instruction::SLT:
require(2);
m_stack[m_stack.size() - 2] = u2s(m_stack.back()) < u2s(m_stack[m_stack.size() - 2]) ? 1 : 0;
m_stack.pop_back();
break;
case Instruction::SGT:
require(2);
m_stack[m_stack.size() - 2] = u2s(m_stack.back()) > u2s(m_stack[m_stack.size() - 2]) ? 1 : 0;
m_stack.pop_back();
break;
case Instruction::EQ:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() == m_stack[m_stack.size() - 2] ? 1 : 0;
m_stack.pop_back();
break;
case Instruction::NOT:
require(1);
m_stack.back() = m_stack.back() ? 0 : 1;
break;
case Instruction::AND:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() & m_stack[m_stack.size() - 2];
m_stack.pop_back();
break;
case Instruction::OR:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() | m_stack[m_stack.size() - 2];
m_stack.pop_back();
break;
case Instruction::XOR:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() ^ m_stack[m_stack.size() - 2];
m_stack.pop_back();
break;
case Instruction::BYTE:
require(2);
m_stack[m_stack.size() - 2] = m_stack.back() < 32 ? (m_stack[m_stack.size() - 2] >> (unsigned)(8 * (31 - m_stack.back()))) & 0xff : 0;
m_stack.pop_back();
break;
case Instruction::ADDMOD:
require(3);
m_stack[m_stack.size() - 3] = u256((bigint(m_stack.back()) + bigint(m_stack[m_stack.size() - 2])) % m_stack[m_stack.size() - 3]);
m_stack.pop_back();
m_stack.pop_back();
break;
case Instruction::MULMOD:
require(3);
m_stack[m_stack.size() - 3] = u256((bigint(m_stack.back()) * bigint(m_stack[m_stack.size() - 2])) % m_stack[m_stack.size() - 3]);
m_stack.pop_back();
m_stack.pop_back();
break;
case Instruction::SHA3:
{
require(2);
unsigned inOff = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned inSize = (unsigned)m_stack.back();
m_stack.pop_back();
m_stack.push_back(sha3(bytesConstRef(m_temp.data() + inOff, inSize)));
break;
}
case Instruction::ADDRESS:
m_stack.push_back(fromAddress(_ext.myAddress));
break;
case Instruction::ORIGIN:
m_stack.push_back(fromAddress(_ext.origin));
break;
case Instruction::BALANCE:
{
require(1);
m_stack.back() = _ext.balance(asAddress(m_stack.back()));
break;
}
case Instruction::CALLER:
m_stack.push_back(fromAddress(_ext.caller));
break;
case Instruction::CALLVALUE:
m_stack.push_back(_ext.value);
break;
case Instruction::CALLDATALOAD:
{
require(1);
if ((unsigned)m_stack.back() + 31 < _ext.data.size())
m_stack.back() = (u256)*(h256 const*)(_ext.data.data() + (unsigned)m_stack.back());
else
{
h256 r;
for (unsigned i = (unsigned)m_stack.back(), e = (unsigned)m_stack.back() + 32, j = 0; i < e; ++i, ++j)
r[j] = i < _ext.data.size() ? _ext.data[i] : 0;
m_stack.back() = (u256)r;
}
break;
}
case Instruction::CALLDATASIZE:
m_stack.push_back(_ext.data.size());
break;
case Instruction::CALLDATACOPY:
{
require(3);
unsigned mf = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned cf = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned l = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned el = cf + l > _ext.data.size() ? _ext.data.size() < cf ? 0 : _ext.data.size() - cf : l;
memcpy(m_temp.data() + mf, _ext.data.data() + cf, el);
memset(m_temp.data() + mf + el, 0, l - el);
break;
}
case Instruction::CODESIZE:
m_stack.push_back(_ext.code.size());
break;
case Instruction::CODECOPY:
{
require(3);
unsigned mf = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned cf = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned l = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned el = cf + l > _ext.code.size() ? _ext.code.size() < cf ? 0 : _ext.code.size() - cf : l;
memcpy(m_temp.data() + mf, _ext.code.data() + cf, el);
memset(m_temp.data() + mf + el, 0, l - el);
break;
}
case Instruction::EXTCODESIZE:
require(1);
m_stack.back() = _ext.codeAt(asAddress(m_stack.back())).size();
break;
case Instruction::EXTCODECOPY:
{
require(4);
Address a = asAddress(m_stack.back());
m_stack.pop_back();
unsigned mf = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned cf = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned l = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned el = cf + l > _ext.codeAt(a).size() ? _ext.codeAt(a).size() < cf ? 0 : _ext.codeAt(a).size() - cf : l;
memcpy(m_temp.data() + mf, _ext.codeAt(a).data() + cf, el);
memset(m_temp.data() + mf + el, 0, l - el);
break;
}
case Instruction::GASPRICE:
m_stack.push_back(_ext.gasPrice);
break;
case Instruction::PREVHASH:
m_stack.push_back(_ext.previousBlock.hash);
break;
case Instruction::COINBASE:
m_stack.push_back((u160)_ext.currentBlock.coinbaseAddress);
break;
case Instruction::TIMESTAMP:
m_stack.push_back(_ext.currentBlock.timestamp);
break;
case Instruction::NUMBER:
m_stack.push_back(_ext.currentBlock.number);
break;
case Instruction::DIFFICULTY:
m_stack.push_back(_ext.currentBlock.difficulty);
break;
case Instruction::GASLIMIT:
m_stack.push_back(1000000);
break;
case Instruction::PUSH1:
case Instruction::PUSH2:
case Instruction::PUSH3:
case Instruction::PUSH4:
case Instruction::PUSH5:
case Instruction::PUSH6:
case Instruction::PUSH7:
case Instruction::PUSH8:
case Instruction::PUSH9:
case Instruction::PUSH10:
case Instruction::PUSH11:
case Instruction::PUSH12:
case Instruction::PUSH13:
case Instruction::PUSH14:
case Instruction::PUSH15:
case Instruction::PUSH16:
case Instruction::PUSH17:
case Instruction::PUSH18:
case Instruction::PUSH19:
case Instruction::PUSH20:
case Instruction::PUSH21:
case Instruction::PUSH22:
case Instruction::PUSH23:
case Instruction::PUSH24:
case Instruction::PUSH25:
case Instruction::PUSH26:
case Instruction::PUSH27:
case Instruction::PUSH28:
case Instruction::PUSH29:
case Instruction::PUSH30:
case Instruction::PUSH31:
case Instruction::PUSH32:
{
int i = (int)inst - (int)Instruction::PUSH1 + 1;
nextPC = m_curPC + 1;
m_stack.push_back(0);
for (; i--; nextPC++)
m_stack.back() = (m_stack.back() << 8) | _ext.getCode(nextPC);
break;
}
case Instruction::POP:
require(1);
m_stack.pop_back();
break;
case Instruction::DUP1:
case Instruction::DUP2:
case Instruction::DUP3:
case Instruction::DUP4:
case Instruction::DUP5:
case Instruction::DUP6:
case Instruction::DUP7:
case Instruction::DUP8:
case Instruction::DUP9:
case Instruction::DUP10:
case Instruction::DUP11:
case Instruction::DUP12:
case Instruction::DUP13:
case Instruction::DUP14:
case Instruction::DUP15:
case Instruction::DUP16:
{
auto n = 1 + (int)inst - (int)Instruction::DUP1;
require(n);
m_stack.push_back(m_stack[m_stack.size() - n]);
break;
}
case Instruction::SWAP1:
case Instruction::SWAP2:
case Instruction::SWAP3:
case Instruction::SWAP4:
case Instruction::SWAP5:
case Instruction::SWAP6:
case Instruction::SWAP7:
case Instruction::SWAP8:
case Instruction::SWAP9:
case Instruction::SWAP10:
case Instruction::SWAP11:
case Instruction::SWAP12:
case Instruction::SWAP13:
case Instruction::SWAP14:
case Instruction::SWAP15:
case Instruction::SWAP16:
{
unsigned n = (int)inst - (int)Instruction::SWAP1 + 2;
require(n);
auto d = m_stack.back();
m_stack.back() = m_stack[m_stack.size() - n];
m_stack[m_stack.size() - n] = d;
break;
}
case Instruction::MLOAD:
{
require(1);
m_stack.back() = (u256)*(h256 const*)(m_temp.data() + (unsigned)m_stack.back());
break;
}
case Instruction::MSTORE:
{
require(2);
*(h256*)&m_temp[(unsigned)m_stack.back()] = (h256)m_stack[m_stack.size() - 2];
m_stack.pop_back();
m_stack.pop_back();
break;
}
case Instruction::MSTORE8:
{
require(2);
m_temp[(unsigned)m_stack.back()] = (byte)(m_stack[m_stack.size() - 2] & 0xff);
m_stack.pop_back();
m_stack.pop_back();
break;
}
case Instruction::SLOAD:
require(1);
m_stack.back() = _ext.store(m_stack.back());
break;
case Instruction::SSTORE:
require(2);
_ext.setStore(m_stack.back(), m_stack[m_stack.size() - 2]);
m_stack.pop_back();
m_stack.pop_back();
break;
case Instruction::JUMP:
require(1);
nextPC = m_stack.back();
m_stack.pop_back();
break;
case Instruction::JUMPI:
require(2);
if (m_stack[m_stack.size() - 2])
nextPC = m_stack.back();
m_stack.pop_back();
m_stack.pop_back();
break;
case Instruction::PC:
m_stack.push_back(m_curPC);
break;
case Instruction::MSIZE:
m_stack.push_back(m_temp.size());
break;
case Instruction::GAS:
m_stack.push_back(m_gas);
break;
case Instruction::CREATE:
{
require(3);
u256 endowment = m_stack.back();
m_stack.pop_back();
unsigned initOff = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned initSize = (unsigned)m_stack.back();
m_stack.pop_back();
if (_ext.balance(_ext.myAddress) >= endowment)
{
_ext.subBalance(endowment);
m_stack.push_back((u160)_ext.create(endowment, &m_gas, bytesConstRef(m_temp.data() + initOff, initSize), _onOp));
}
else
m_stack.push_back(0);
break;
}
case Instruction::CALL:
case Instruction::CALLSTATELESS:
{
require(7);
u256 gas = m_stack.back();
m_stack.pop_back();
Address receiveAddress = asAddress(m_stack.back());
m_stack.pop_back();
u256 value = m_stack.back();
m_stack.pop_back();
unsigned inOff = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned inSize = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned outOff = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned outSize = (unsigned)m_stack.back();
m_stack.pop_back();
if (_ext.balance(_ext.myAddress) >= value)
{
_ext.subBalance(value);
m_stack.push_back(_ext.call(inst == Instruction::CALL ? receiveAddress : _ext.myAddress, value, bytesConstRef(m_temp.data() + inOff, inSize), &gas, bytesRef(m_temp.data() + outOff, outSize), _onOp, Address(), receiveAddress));
}
else
m_stack.push_back(0);
m_gas += gas;
break;
}
case Instruction::RETURN:
{
require(2);
unsigned b = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned s = (unsigned)m_stack.back();
m_stack.pop_back();
return bytesConstRef(m_temp.data() + b, s);
}
case Instruction::SUICIDE:
{
require(1);
Address dest = asAddress(m_stack.back());
_ext.suicide(dest);
// ...follow through to...
}
case Instruction::STOP:
return bytesConstRef();
case Instruction::POST:
{
require(5);
u256 gas = m_stack.back();
m_stack.pop_back();
u160 receiveAddress = asAddress(m_stack.back());
m_stack.pop_back();
u256 value = m_stack.back();
m_stack.pop_back();
unsigned inOff = (unsigned)m_stack.back();
m_stack.pop_back();
unsigned inSize = (unsigned)m_stack.back();
m_stack.pop_back();
if (_ext.balance(_ext.myAddress) >= value)
{
_ext.subBalance(value);
_ext.post(receiveAddress, value, bytesConstRef(m_temp.data() + inOff, inSize), gas);
}
break;
}
default:
BOOST_THROW_EXCEPTION(BadInstruction());
}
}
if (_steps == (uint64_t)-1)
BOOST_THROW_EXCEPTION(StepsDone());
return bytesConstRef();
}
}