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use std::sync::atomic::{AtomicUsize, AtomicBool, Ordering as AtomicOrdering};
use std::sync::Weak;
use std::time::{UNIX_EPOCH, Duration};
use util::*;
use ethkey::{verify_address, Signature};
use rlp::{UntrustedRlp, View, encode};
use account_provider::AccountProvider;
use block::*;
use spec::CommonParams;
use engines::{Engine, Seal, EngineError};
use header::Header;
use error::{Error, BlockError};
use evm::Schedule;
use ethjson;
use io::{IoContext, IoHandler, TimerToken, IoService};
use env_info::EnvInfo;
use builtin::Builtin;
use client::{Client, EngineClient};
use state::CleanupMode;
use super::signer::EngineSigner;
use super::validator_set::{ValidatorSet, new_validator_set};
#[derive(Debug, PartialEq)]
pub struct AuthorityRoundParams {
pub gas_limit_bound_divisor: U256,
pub step_duration: Duration,
pub block_reward: U256,
pub start_step: Option<u64>,
pub validators: ethjson::spec::ValidatorSet,
}
impl From<ethjson::spec::AuthorityRoundParams> for AuthorityRoundParams {
fn from(p: ethjson::spec::AuthorityRoundParams) -> Self {
AuthorityRoundParams {
gas_limit_bound_divisor: p.gas_limit_bound_divisor.into(),
step_duration: Duration::from_secs(p.step_duration.into()),
validators: p.validators,
block_reward: p.block_reward.map_or_else(U256::zero, Into::into),
start_step: p.start_step.map(Into::into),
}
}
}
pub struct AuthorityRound {
params: CommonParams,
gas_limit_bound_divisor: U256,
block_reward: U256,
step_duration: Duration,
builtins: BTreeMap<Address, Builtin>,
transition_service: IoService<()>,
step: AtomicUsize,
proposed: AtomicBool,
client: RwLock<Option<Weak<EngineClient>>>,
signer: EngineSigner,
validators: Box<ValidatorSet + Send + Sync>,
}
fn header_step(header: &Header) -> Result<usize, ::rlp::DecoderError> {
UntrustedRlp::new(&header.seal().get(0).expect("was either checked with verify_block_basic or is genesis; has 2 fields; qed (Make sure the spec file has a correct genesis seal)")).as_val()
}
fn header_signature(header: &Header) -> Result<Signature, ::rlp::DecoderError> {
UntrustedRlp::new(&header.seal().get(1).expect("was checked with verify_block_basic; has 2 fields; qed")).as_val::<H520>().map(Into::into)
}
trait AsMillis {
fn as_millis(&self) -> u64;
}
impl AsMillis for Duration {
fn as_millis(&self) -> u64 {
self.as_secs()*1_000 + (self.subsec_nanos()/1_000_000) as u64
}
}
impl AuthorityRound {
pub fn new(params: CommonParams, our_params: AuthorityRoundParams, builtins: BTreeMap<Address, Builtin>) -> Result<Arc<Self>, Error> {
let should_timeout = our_params.start_step.is_none();
let initial_step = our_params.start_step.unwrap_or_else(|| (unix_now().as_secs() / our_params.step_duration.as_secs())) as usize;
let engine = Arc::new(
AuthorityRound {
params: params,
gas_limit_bound_divisor: our_params.gas_limit_bound_divisor,
block_reward: our_params.block_reward,
step_duration: our_params.step_duration,
builtins: builtins,
transition_service: IoService::<()>::start()?,
step: AtomicUsize::new(initial_step),
proposed: AtomicBool::new(false),
client: RwLock::new(None),
signer: Default::default(),
validators: new_validator_set(our_params.validators),
});
if should_timeout {
let handler = TransitionHandler { engine: Arc::downgrade(&engine) };
engine.transition_service.register_handler(Arc::new(handler))?;
}
Ok(engine)
}
fn remaining_step_duration(&self) -> Duration {
let now = unix_now();
let step_end = self.step_duration * (self.step.load(AtomicOrdering::SeqCst) as u32 + 1);
if step_end > now {
step_end - now
} else {
Duration::from_secs(0)
}
}
fn step_proposer(&self, step: usize) -> Address {
self.validators.get(step)
}
fn is_step_proposer(&self, step: usize, address: &Address) -> bool {
self.step_proposer(step) == *address
}
}
fn unix_now() -> Duration {
UNIX_EPOCH.elapsed().expect("Valid time has to be set in your system.")
}
struct TransitionHandler {
engine: Weak<AuthorityRound>,
}
const ENGINE_TIMEOUT_TOKEN: TimerToken = 23;
impl IoHandler<()> for TransitionHandler {
fn initialize(&self, io: &IoContext<()>) {
if let Some(engine) = self.engine.upgrade() {
io.register_timer_once(ENGINE_TIMEOUT_TOKEN, engine.remaining_step_duration().as_millis())
.unwrap_or_else(|e| warn!(target: "poa", "Failed to start consensus step timer: {}.", e))
}
}
fn timeout(&self, io: &IoContext<()>, timer: TimerToken) {
if timer == ENGINE_TIMEOUT_TOKEN {
if let Some(engine) = self.engine.upgrade() {
engine.step();
io.register_timer_once(ENGINE_TIMEOUT_TOKEN, engine.remaining_step_duration().as_millis())
.unwrap_or_else(|e| warn!(target: "poa", "Failed to restart consensus step timer: {}.", e))
}
}
}
}
impl Engine for AuthorityRound {
fn name(&self) -> &str { "AuthorityRound" }
fn version(&self) -> SemanticVersion { SemanticVersion::new(1, 0, 0) }
fn seal_fields(&self) -> usize { 2 }
fn params(&self) -> &CommonParams { &self.params }
fn builtins(&self) -> &BTreeMap<Address, Builtin> { &self.builtins }
fn step(&self) {
self.step.fetch_add(1, AtomicOrdering::SeqCst);
self.proposed.store(false, AtomicOrdering::SeqCst);
if let Some(ref weak) = *self.client.read() {
if let Some(c) = weak.upgrade() {
c.update_sealing();
}
}
}
fn extra_info(&self, header: &Header) -> BTreeMap<String, String> {
map![
"step".into() => header_step(header).as_ref().map(ToString::to_string).unwrap_or("".into()),
"signature".into() => header_signature(header).as_ref().map(ToString::to_string).unwrap_or("".into())
]
}
fn schedule(&self, _env_info: &EnvInfo) -> Schedule {
Schedule::new_post_eip150(usize::max_value(), true, true, true)
}
fn populate_from_parent(&self, header: &mut Header, parent: &Header, gas_floor_target: U256, _gas_ceil_target: U256) {
let new_difficulty = U256::from(U128::max_value()) + header_step(parent).expect("Header has been verified; qed").into() - self.step.load(AtomicOrdering::SeqCst).into();
header.set_difficulty(new_difficulty);
header.set_gas_limit({
let gas_limit = parent.gas_limit().clone();
let bound_divisor = self.gas_limit_bound_divisor;
if gas_limit < gas_floor_target {
min(gas_floor_target, gas_limit + gas_limit / bound_divisor - 1.into())
} else {
max(gas_floor_target, gas_limit - gas_limit / bound_divisor + 1.into())
}
});
}
fn is_sealer(&self, author: &Address) -> Option<bool> {
Some(self.validators.contains(author))
}
fn generate_seal(&self, block: &ExecutedBlock) -> Seal {
if self.proposed.load(AtomicOrdering::SeqCst) { return Seal::None; }
let header = block.header();
let step = self.step.load(AtomicOrdering::SeqCst);
if self.is_step_proposer(step, header.author()) {
if let Ok(signature) = self.signer.sign(header.bare_hash()) {
trace!(target: "poa", "generate_seal: Issuing a block for step {}.", step);
self.proposed.store(true, AtomicOrdering::SeqCst);
return Seal::Regular(vec![encode(&step).to_vec(), encode(&(&H520::from(signature) as &[u8])).to_vec()]);
} else {
warn!(target: "poa", "generate_seal: FAIL: Accounts secret key unavailable.");
}
} else {
trace!(target: "poa", "generate_seal: Not a proposer for step {}.", step);
}
Seal::None
}
fn on_close_block(&self, block: &mut ExecutedBlock) {
let fields = block.fields_mut();
fields.state.add_balance(fields.header.author(), &self.block_reward, CleanupMode::NoEmpty);
if let Err(e) = fields.state.commit() {
warn!("Encountered error on state commit: {}", e);
}
}
fn verify_block_basic(&self, header: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
if header.seal().len() != self.seal_fields() {
trace!(target: "poa", "verify_block_basic: wrong number of seal fields");
Err(From::from(BlockError::InvalidSealArity(
Mismatch { expected: self.seal_fields(), found: header.seal().len() }
)))
} else {
Ok(())
}
}
fn verify_block_unordered(&self, header: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
let header_step = header_step(header)?;
if header_step <= self.step.load(AtomicOrdering::SeqCst) + 1 {
let proposer_signature = header_signature(header)?;
let correct_proposer = self.step_proposer(header_step);
if verify_address(&correct_proposer, &proposer_signature, &header.bare_hash())? {
Ok(())
} else {
trace!(target: "poa", "verify_block_unordered: bad proposer for step: {}", header_step);
Err(EngineError::NotProposer(Mismatch { expected: correct_proposer, found: header.author().clone() }))?
}
} else {
trace!(target: "poa", "verify_block_unordered: block from the future");
self.validators.report_benign(header.author());
Err(BlockError::InvalidSeal)?
}
}
fn verify_block_family(&self, header: &Header, parent: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
if header.number() == 0 {
return Err(From::from(BlockError::RidiculousNumber(OutOfBounds { min: Some(1), max: None, found: header.number() })));
}
let step = header_step(header)?;
if step == header_step(parent)? {
trace!(target: "poa", "Multiple blocks proposed for step {}.", step);
self.validators.report_malicious(header.author());
Err(EngineError::DoubleVote(header.author().clone()))?;
}
let gas_limit_divisor = self.gas_limit_bound_divisor;
let min_gas = parent.gas_limit().clone() - parent.gas_limit().clone() / gas_limit_divisor;
let max_gas = parent.gas_limit().clone() + parent.gas_limit().clone() / gas_limit_divisor;
if header.gas_limit() <= &min_gas || header.gas_limit() >= &max_gas {
return Err(From::from(BlockError::InvalidGasLimit(OutOfBounds { min: Some(min_gas), max: Some(max_gas), found: header.gas_limit().clone() })));
}
Ok(())
}
fn register_client(&self, client: Weak<Client>) {
*self.client.write() = Some(client.clone());
self.validators.register_contract(client);
}
fn set_signer(&self, ap: Arc<AccountProvider>, address: Address, password: String) {
self.signer.set(ap, address, password);
}
fn sign(&self, hash: H256) -> Result<Signature, Error> {
self.signer.sign(hash).map_err(Into::into)
}
}
#[cfg(test)]
mod tests {
use util::*;
use env_info::EnvInfo;
use header::Header;
use error::{Error, BlockError};
use ethkey::Secret;
use rlp::encode;
use block::*;
use tests::helpers::*;
use account_provider::AccountProvider;
use spec::Spec;
use engines::Seal;
#[test]
fn has_valid_metadata() {
let engine = Spec::new_test_round().engine;
assert!(!engine.name().is_empty());
assert!(engine.version().major >= 1);
}
#[test]
fn can_return_schedule() {
let engine = Spec::new_test_round().engine;
let schedule = engine.schedule(&EnvInfo {
number: 10000000,
author: 0.into(),
timestamp: 0,
difficulty: 0.into(),
last_hashes: Arc::new(vec![]),
gas_used: 0.into(),
gas_limit: 0.into(),
});
assert!(schedule.stack_limit > 0);
}
#[test]
fn verification_fails_on_short_seal() {
let engine = Spec::new_test_round().engine;
let header: Header = Header::default();
let verify_result = engine.verify_block_basic(&header, None);
match verify_result {
Err(Error::Block(BlockError::InvalidSealArity(_))) => {},
Err(_) => { panic!("should be block seal-arity mismatch error (got {:?})", verify_result); },
_ => { panic!("Should be error, got Ok"); },
}
}
#[test]
fn can_do_signature_verification_fail() {
let engine = Spec::new_test_round().engine;
let mut header: Header = Header::default();
header.set_seal(vec![encode(&H520::default()).to_vec()]);
let verify_result = engine.verify_block_unordered(&header, None);
assert!(verify_result.is_err());
}
#[test]
fn generates_seal_and_does_not_double_propose() {
let tap = Arc::new(AccountProvider::transient_provider());
let addr1 = tap.insert_account(Secret::from_slice(&"1".sha3()).unwrap(), "1").unwrap();
let addr2 = tap.insert_account(Secret::from_slice(&"2".sha3()).unwrap(), "2").unwrap();
let spec = Spec::new_test_round();
let engine = &*spec.engine;
let genesis_header = spec.genesis_header();
let db1 = spec.ensure_db_good(get_temp_state_db().take(), &Default::default()).unwrap();
let db2 = spec.ensure_db_good(get_temp_state_db().take(), &Default::default()).unwrap();
let last_hashes = Arc::new(vec![genesis_header.hash()]);
let b1 = OpenBlock::new(engine, Default::default(), false, db1, &genesis_header, last_hashes.clone(), addr1, (3141562.into(), 31415620.into()), vec![]).unwrap();
let b1 = b1.close_and_lock();
let b2 = OpenBlock::new(engine, Default::default(), false, db2, &genesis_header, last_hashes, addr2, (3141562.into(), 31415620.into()), vec![]).unwrap();
let b2 = b2.close_and_lock();
engine.set_signer(tap.clone(), addr1, "1".into());
if let Seal::Regular(seal) = engine.generate_seal(b1.block()) {
assert!(b1.clone().try_seal(engine, seal).is_ok());
assert!(engine.generate_seal(b1.block()) == Seal::None);
}
engine.set_signer(tap, addr2, "2".into());
if let Seal::Regular(seal) = engine.generate_seal(b2.block()) {
assert!(b2.clone().try_seal(engine, seal).is_ok());
assert!(engine.generate_seal(b2.block()) == Seal::None);
}
}
#[test]
fn proposer_switching() {
let mut header: Header = Header::default();
let tap = AccountProvider::transient_provider();
let addr = tap.insert_account(Secret::from_slice(&"0".sha3()).unwrap(), "0").unwrap();
header.set_author(addr);
let engine = Spec::new_test_round().engine;
let signature = tap.sign(addr, Some("0".into()), header.bare_hash()).unwrap();
header.set_seal(vec![encode(&2usize).to_vec(), encode(&(&*signature as &[u8])).to_vec()]);
assert!(engine.verify_block_seal(&header).is_err());
header.set_seal(vec![encode(&1usize).to_vec(), encode(&(&*signature as &[u8])).to_vec()]);
assert!(engine.verify_block_seal(&header).is_ok());
}
#[test]
fn rejects_future_block() {
let mut header: Header = Header::default();
let tap = AccountProvider::transient_provider();
let addr = tap.insert_account(Secret::from_slice(&"0".sha3()).unwrap(), "0").unwrap();
header.set_author(addr);
let engine = Spec::new_test_round().engine;
let signature = tap.sign(addr, Some("0".into()), header.bare_hash()).unwrap();
header.set_seal(vec![encode(&1usize).to_vec(), encode(&(&*signature as &[u8])).to_vec()]);
assert!(engine.verify_block_seal(&header).is_ok());
header.set_seal(vec![encode(&5usize).to_vec(), encode(&(&*signature as &[u8])).to_vec()]);
assert!(engine.verify_block_seal(&header).is_err());
}
}