openethereum/ethcore/src/machine.rs

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// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity 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.
// Parity 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 Parity. If not, see <http://www.gnu.org/licenses/>.
//! Ethereum-like state machine definition.
use std::collections::{BTreeMap, HashMap};
use std::cmp;
use std::sync::Arc;
use block::ExecutedBlock;
use builtin::Builtin;
use client::BlockChainClient;
use error::{Error, TransactionError};
use executive::Executive;
use header::{BlockNumber, Header};
use spec::CommonParams;
use state::{CleanupMode, Substate};
use trace::{NoopTracer, NoopVMTracer, Tracer, ExecutiveTracer, RewardType};
use transaction::{SYSTEM_ADDRESS, UnverifiedTransaction, SignedTransaction};
use tx_filter::TransactionFilter;
use bigint::prelude::U256;
use bytes::BytesRef;
use util::Address;
use vm::{CallType, ActionParams, ActionValue, ParamsType};
use vm::{EnvInfo, Schedule, CreateContractAddress};
/// Parity tries to round block.gas_limit to multiple of this constant
pub const PARITY_GAS_LIMIT_DETERMINANT: U256 = U256([37, 0, 0, 0]);
/// Ethash-specific extensions.
#[derive(Debug, Clone)]
pub struct EthashExtensions {
/// Homestead transition block number.
pub homestead_transition: BlockNumber,
/// EIP150 transition block number.
pub eip150_transition: BlockNumber,
/// Number of first block where EIP-160 rules begin.
pub eip160_transition: u64,
/// Number of first block where EIP-161.abc begin.
pub eip161abc_transition: u64,
/// Number of first block where EIP-161.d begins.
pub eip161d_transition: u64,
/// DAO hard-fork transition block (X).
pub dao_hardfork_transition: u64,
/// DAO hard-fork refund contract address (C).
pub dao_hardfork_beneficiary: Address,
/// DAO hard-fork DAO accounts list (L)
pub dao_hardfork_accounts: Vec<Address>,
}
impl From<::ethjson::spec::EthashParams> for EthashExtensions {
fn from(p: ::ethjson::spec::EthashParams) -> Self {
EthashExtensions {
homestead_transition: p.homestead_transition.map_or(0, Into::into),
eip150_transition: p.eip150_transition.map_or(0, Into::into),
eip160_transition: p.eip160_transition.map_or(0, Into::into),
eip161abc_transition: p.eip161abc_transition.map_or(0, Into::into),
eip161d_transition: p.eip161d_transition.map_or(u64::max_value(), Into::into),
dao_hardfork_transition: p.dao_hardfork_transition.map_or(u64::max_value(), Into::into),
dao_hardfork_beneficiary: p.dao_hardfork_beneficiary.map_or_else(Address::new, Into::into),
dao_hardfork_accounts: p.dao_hardfork_accounts.unwrap_or_else(Vec::new).into_iter().map(Into::into).collect(),
}
}
}
/// Special rules to be applied to the schedule.
pub type ScheduleCreationRules = Fn(&mut Schedule, BlockNumber) + Sync + Send;
/// An ethereum-like state machine.
pub struct EthereumMachine {
params: CommonParams,
builtins: Arc<BTreeMap<Address, Builtin>>,
tx_filter: Option<Arc<TransactionFilter>>,
ethash_extensions: Option<EthashExtensions>,
schedule_rules: Option<Box<ScheduleCreationRules>>,
}
impl EthereumMachine {
/// Regular ethereum machine.
pub fn regular(params: CommonParams, builtins: BTreeMap<Address, Builtin>) -> EthereumMachine {
let tx_filter = TransactionFilter::from_params(&params).map(Arc::new);
EthereumMachine {
params: params,
builtins: Arc::new(builtins),
tx_filter: tx_filter,
ethash_extensions: None,
schedule_rules: None,
}
}
/// Ethereum machine with ethash extensions.
// TODO: either unify or specify to mainnet specifically and include other specific-chain HFs?
pub fn with_ethash_extensions(params: CommonParams, builtins: BTreeMap<Address, Builtin>, extensions: EthashExtensions) -> EthereumMachine {
let mut machine = EthereumMachine::regular(params, builtins);
machine.ethash_extensions = Some(extensions);
machine
}
/// Attach special rules to the creation of schedule.
pub fn set_schedule_creation_rules(&mut self, rules: Box<ScheduleCreationRules>) {
self.schedule_rules = Some(rules);
}
/// Get a reference to the ethash-specific extensions.
pub fn ethash_extensions(&self) -> Option<&EthashExtensions> {
self.ethash_extensions.as_ref()
}
}
impl EthereumMachine {
/// Execute a call as the system address.
pub fn execute_as_system(
&self,
block: &mut ExecutedBlock,
contract_address: Address,
gas: U256,
data: Option<Vec<u8>>,
) -> Result<Vec<u8>, Error> {
let env_info = {
let mut env_info = block.env_info();
env_info.gas_limit = env_info.gas_used + gas;
env_info
};
let mut state = block.fields_mut().state;
let params = ActionParams {
code_address: contract_address.clone(),
address: contract_address.clone(),
sender: SYSTEM_ADDRESS.clone(),
origin: SYSTEM_ADDRESS.clone(),
gas: gas,
gas_price: 0.into(),
value: ActionValue::Transfer(0.into()),
code: state.code(&contract_address)?,
code_hash: Some(state.code_hash(&contract_address)?),
data: data,
call_type: CallType::Call,
params_type: ParamsType::Separate,
};
let mut ex = Executive::new(&mut state, &env_info, self);
let mut substate = Substate::new();
let mut output = Vec::new();
if let Err(e) = ex.call(params, &mut substate, BytesRef::Flexible(&mut output), &mut NoopTracer, &mut NoopVMTracer) {
warn!("Encountered error on making system call: {}", e);
}
Ok(output)
}
/// Push last known block hash to the state.
fn push_last_hash(&self, block: &mut ExecutedBlock) -> Result<(), Error> {
let params = self.params();
if block.fields().header.number() == params.eip210_transition {
let state = block.fields_mut().state;
state.init_code(&params.eip210_contract_address, params.eip210_contract_code.clone())?;
}
if block.fields().header.number() >= params.eip210_transition {
let parent_hash = block.fields().header.parent_hash().clone();
let _ = self.execute_as_system(
block,
params.eip210_contract_address,
params.eip210_contract_gas,
Some(parent_hash.to_vec()),
)?;
}
Ok(())
}
/// Logic to perform on a new block: updating last hashes and the DAO
/// fork, for ethash.
pub fn on_new_block(&self, block: &mut ExecutedBlock) -> Result<(), Error> {
self.push_last_hash(block)?;
if let Some(ref ethash_params) = self.ethash_extensions {
if block.fields().header.number() == ethash_params.dao_hardfork_transition {
let state = block.fields_mut().state;
for child in &ethash_params.dao_hardfork_accounts {
let beneficiary = &ethash_params.dao_hardfork_beneficiary;
state.balance(child)
.and_then(|b| state.transfer_balance(child, beneficiary, &b, CleanupMode::NoEmpty))?;
}
}
}
Ok(())
}
/// Populate a header's fields based on its parent's header.
/// Usually implements the chain scoring rule based on weight.
/// The gas floor target must not be lower than the engine's minimum gas limit.
pub fn populate_from_parent(&self, header: &mut Header, parent: &Header, gas_floor_target: U256, gas_ceil_target: U256) {
header.set_difficulty(parent.difficulty().clone());
if let Some(ref ethash_params) = self.ethash_extensions {
let gas_limit = {
let gas_limit = parent.gas_limit().clone();
let bound_divisor = self.params().gas_limit_bound_divisor;
let lower_limit = gas_limit - gas_limit / bound_divisor + 1.into();
let upper_limit = gas_limit + gas_limit / bound_divisor - 1.into();
let gas_limit = if gas_limit < gas_floor_target {
let gas_limit = cmp::min(gas_floor_target, upper_limit);
round_block_gas_limit(gas_limit, lower_limit, upper_limit)
} else if gas_limit > gas_ceil_target {
let gas_limit = cmp::max(gas_ceil_target, lower_limit);
round_block_gas_limit(gas_limit, lower_limit, upper_limit)
} else {
let total_lower_limit = cmp::max(lower_limit, gas_floor_target);
let total_upper_limit = cmp::min(upper_limit, gas_ceil_target);
let gas_limit = cmp::max(gas_floor_target, cmp::min(total_upper_limit,
lower_limit + (header.gas_used().clone() * 6.into() / 5.into()) / bound_divisor));
round_block_gas_limit(gas_limit, total_lower_limit, total_upper_limit)
};
// ensure that we are not violating protocol limits
debug_assert!(gas_limit >= lower_limit);
debug_assert!(gas_limit <= upper_limit);
gas_limit
};
header.set_gas_limit(gas_limit);
if header.number() >= ethash_params.dao_hardfork_transition &&
header.number() <= ethash_params.dao_hardfork_transition + 9 {
header.set_extra_data(b"dao-hard-fork"[..].to_owned());
}
return
}
header.set_gas_limit({
let gas_limit = parent.gas_limit().clone();
let bound_divisor = self.params().gas_limit_bound_divisor;
if gas_limit < gas_floor_target {
cmp::min(gas_floor_target, gas_limit + gas_limit / bound_divisor - 1.into())
} else {
cmp::max(gas_floor_target, gas_limit - gas_limit / bound_divisor + 1.into())
}
});
}
/// Get the general parameters of the chain.
pub fn params(&self) -> &CommonParams {
&self.params
}
/// Get the EVM schedule for the given block number.
pub fn schedule(&self, block_number: BlockNumber) -> Schedule {
let mut schedule = match self.ethash_extensions {
None => self.params.schedule(block_number),
Some(ref ext) => {
if block_number < ext.homestead_transition {
Schedule::new_frontier()
} else if block_number < ext.eip150_transition {
Schedule::new_homestead()
} else {
// There's no max_code_size transition so we tie it to eip161abc
let max_code_size = if block_number >= ext.eip161abc_transition {
self.params.max_code_size as usize
} else {
usize::max_value()
};
let mut schedule = Schedule::new_post_eip150(
max_code_size,
block_number >= ext.eip160_transition,
block_number >= ext.eip161abc_transition,
block_number >= ext.eip161d_transition
);
self.params.update_schedule(block_number, &mut schedule);
schedule
}
}
};
if let Some(ref rules) = self.schedule_rules {
(rules)(&mut schedule, block_number)
}
schedule
}
/// Builtin-contracts for the chain..
pub fn builtins(&self) -> &BTreeMap<Address, Builtin> {
&*self.builtins
}
/// Attempt to get a handle to a built-in contract.
/// Only returns references to activated built-ins.
// TODO: builtin contract routing - to do this properly, it will require removing the built-in configuration-reading logic
// from Spec into here and removing the Spec::builtins field.
pub fn builtin(&self, a: &Address, block_number: BlockNumber) -> Option<&Builtin> {
self.builtins()
.get(a)
.and_then(|b| if b.is_active(block_number) { Some(b) } else { None })
}
/// Some intrinsic operation parameters; by default they take their value from the `spec()`'s `engine_params`.
pub fn maximum_extra_data_size(&self) -> usize { self.params().maximum_extra_data_size }
/// The nonce with which accounts begin at given block.
pub fn account_start_nonce(&self, block: u64) -> U256 {
let params = self.params();
if block >= params.dust_protection_transition {
U256::from(params.nonce_cap_increment) * U256::from(block)
} else {
params.account_start_nonce
}
}
/// The network ID that transactions should be signed with.
pub fn signing_chain_id(&self, env_info: &EnvInfo) -> Option<u64> {
let params = self.params();
if env_info.number >= params.eip155_transition {
Some(params.chain_id)
} else {
None
}
}
/// Returns new contract address generation scheme at given block number.
pub fn create_address_scheme(&self, number: BlockNumber) -> CreateContractAddress {
if number >= self.params().eip86_transition {
CreateContractAddress::FromCodeHash
} else {
CreateContractAddress::FromSenderAndNonce
}
}
/// Verify a particular transaction is valid, regardless of order.
pub fn verify_transaction_unordered(&self, t: UnverifiedTransaction, _header: &Header) -> Result<SignedTransaction, Error> {
SignedTransaction::new(t)
}
/// Does basic verification of the transaction.
pub fn verify_transaction_basic(&self, t: &UnverifiedTransaction, header: &Header) -> Result<(), Error> {
let check_low_s = match self.ethash_extensions {
Some(ref ext) => header.number() >= ext.homestead_transition,
None => true,
};
let chain_id = if header.number() < self.params().validate_chain_id_transition {
t.chain_id()
} else if header.number() >= self.params().eip155_transition {
Some(self.params().chain_id)
} else {
None
};
t.verify_basic(check_low_s, chain_id, false)?;
Ok(())
}
/// Does verification of the transaction against the parent state.
// TODO: refine the bound here to be a "state provider" or similar as opposed
// to full client functionality.
pub fn verify_transaction(&self, t: &SignedTransaction, header: &Header, client: &BlockChainClient) -> Result<(), Error> {
if let Some(ref filter) = self.tx_filter.as_ref() {
if !filter.transaction_allowed(header.parent_hash(), t, client) {
return Err(TransactionError::NotAllowed.into())
}
}
Ok(())
}
/// If this machine supports wasm.
pub fn supports_wasm(&self) -> bool {
self.params().wasm
}
/// Additional params.
pub fn additional_params(&self) -> HashMap<String, String> {
hash_map![
"registrar".to_owned() => self.params.registrar.hex()
]
}
}
/// Auxiliary data fetcher for an Ethereum machine. In Ethereum-like machines
/// there are two kinds of auxiliary data: bodies and receipts.
#[derive(Default, Clone)]
pub struct AuxiliaryData<'a> {
/// The full block bytes, including the header.
pub bytes: Option<&'a [u8]>,
/// The block receipts.
pub receipts: Option<&'a [::receipt::Receipt]>,
}
/// Type alias for a function we can make calls through synchronously.
/// Returns the call result and state proof for each call.
pub type Call<'a> = Fn(Address, Vec<u8>) -> Result<(Vec<u8>, Vec<Vec<u8>>), String> + 'a;
/// Request for auxiliary data of a block.
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum AuxiliaryRequest {
/// Needs the body.
Body,
/// Needs the receipts.
Receipts,
/// Needs both body and receipts.
Both,
}
impl ::parity_machine::Machine for EthereumMachine {
type Header = Header;
type LiveBlock = ExecutedBlock;
type EngineClient = ::client::EngineClient;
type AuxiliaryRequest = AuxiliaryRequest;
type Error = Error;
}
impl<'a> ::parity_machine::LocalizedMachine<'a> for EthereumMachine {
type StateContext = Call<'a>;
type AuxiliaryData = AuxiliaryData<'a>;
}
impl ::parity_machine::WithBalances for EthereumMachine {
fn balance(&self, live: &ExecutedBlock, address: &Address) -> Result<U256, Error> {
live.fields().state.balance(address).map_err(Into::into)
}
fn add_balance(&self, live: &mut ExecutedBlock, address: &Address, amount: &U256) -> Result<(), Error> {
live.fields_mut().state.add_balance(address, amount, CleanupMode::NoEmpty).map_err(Into::into)
}
fn note_rewards(
&self,
live: &mut Self::LiveBlock,
direct: &[(Address, U256)],
indirect: &[(Address, U256)],
) -> Result<(), Self::Error> {
use block::IsBlock;
if !live.tracing_enabled() { return Ok(()) }
let mut tracer = ExecutiveTracer::default();
for &(address, amount) in direct {
tracer.trace_reward(address, amount, RewardType::Block);
}
for &(address, amount) in indirect {
tracer.trace_reward(address, amount, RewardType::Uncle);
}
live.fields_mut().push_traces(tracer);
Ok(())
}
}
// Try to round gas_limit a bit so that:
// 1) it will still be in desired range
// 2) it will be a nearest (with tendency to increase) multiple of PARITY_GAS_LIMIT_DETERMINANT
fn round_block_gas_limit(gas_limit: U256, lower_limit: U256, upper_limit: U256) -> U256 {
let increased_gas_limit = gas_limit + (PARITY_GAS_LIMIT_DETERMINANT - gas_limit % PARITY_GAS_LIMIT_DETERMINANT);
if increased_gas_limit > upper_limit {
let decreased_gas_limit = increased_gas_limit - PARITY_GAS_LIMIT_DETERMINANT;
if decreased_gas_limit < lower_limit {
gas_limit
} else {
decreased_gas_limit
}
} else {
increased_gas_limit
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn ethash_gas_limit_is_multiple_of_determinant() {
use bigint::prelude::U256;
let spec = ::ethereum::new_homestead_test();
let ethparams = ::tests::helpers::get_default_ethash_extensions();
let machine = EthereumMachine::with_ethash_extensions(
spec.params().clone(),
Default::default(),
ethparams,
);
let mut parent = ::header::Header::new();
let mut header = ::header::Header::new();
header.set_number(1);
// this test will work for this constant only
assert_eq!(PARITY_GAS_LIMIT_DETERMINANT, U256::from(37));
// when parent.gas_limit < gas_floor_target:
parent.set_gas_limit(U256::from(50_000));
machine.populate_from_parent(&mut header, &parent, U256::from(100_000), U256::from(200_000));
assert_eq!(*header.gas_limit(), U256::from(50_024));
// when parent.gas_limit > gas_ceil_target:
parent.set_gas_limit(U256::from(250_000));
machine.populate_from_parent(&mut header, &parent, U256::from(100_000), U256::from(200_000));
assert_eq!(*header.gas_limit(), U256::from(249_787));
// when parent.gas_limit is in miner's range
header.set_gas_used(U256::from(150_000));
parent.set_gas_limit(U256::from(150_000));
machine.populate_from_parent(&mut header, &parent, U256::from(100_000), U256::from(200_000));
assert_eq!(*header.gas_limit(), U256::from(150_035));
// when parent.gas_limit is in miner's range
// && we can NOT increase it to be multiple of constant
header.set_gas_used(U256::from(150_000));
parent.set_gas_limit(U256::from(150_000));
machine.populate_from_parent(&mut header, &parent, U256::from(100_000), U256::from(150_002));
assert_eq!(*header.gas_limit(), U256::from(149_998));
// when parent.gas_limit is in miner's range
// && we can NOT increase it to be multiple of constant
// && we can NOT decrease it to be multiple of constant
header.set_gas_used(U256::from(150_000));
parent.set_gas_limit(U256::from(150_000));
machine.populate_from_parent(&mut header, &parent, U256::from(150_000), U256::from(150_002));
assert_eq!(*header.gas_limit(), U256::from(150_002));
}
}