Merge branch 'network' into verification

This commit is contained in:
arkpar 2016-01-10 19:47:32 +01:00
commit 5f4cd7f197
8 changed files with 230 additions and 232 deletions

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@ -1,6 +1,7 @@
extern crate ethcore_util as util;
extern crate ethcore;
extern crate rustc_serialize;
extern crate env_logger;
use std::io::*;
use std::env;
@ -12,6 +13,7 @@ use ethcore::sync::EthSync;
use ethcore::ethereum;
fn main() {
::env_logger::init().ok();
let mut service = NetworkService::start().unwrap();
//TODO: replace with proper genesis and chain params.
let frontier = ethereum::new_frontier();

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@ -1,7 +1,6 @@
use common::*;
use block::Block;
use spec::Spec;
use verification::VerificationError;
/// A consensus mechanism for the chain. Generally either proof-of-work or proof-of-stake-based.
/// Provides hooks into each of the major parts of block import.
@ -38,7 +37,9 @@ pub trait Engine {
/// `parent` (the parent header) and `block` (the header's full block) may be provided for additional
/// checks. Returns either a null `Ok` or a general error detailing the problem with import.
// TODO: consider including State in the params.
fn verify_block(&self, _mode: VerificationMode, _header: &Header, _parent: Option<&Header>, _block: Option<&[u8]>) -> Result<(), Error> { Ok(()) }
fn verify_block_basic(&self, _header: &Header, _block: Option<&[u8]>) -> Result<(), Error> { Ok(()) }
fn verify_block_unordered(&self, _header: &Header, _block: Option<&[u8]>) -> Result<(), Error> { Ok(()) }
fn verify_block_final(&self, _header: &Header, _parent: &Header, _block: Option<&[u8]>) -> Result<(), Error> { Ok(()) }
/// Additional verification for transactions in blocks.
// TODO: Add flags for which bits of the transaction to check.
@ -57,11 +58,3 @@ pub trait Engine {
// TODO: sealing stuff - though might want to leave this for later.
}
#[derive(Debug, PartialEq, Eq)]
pub enum VerificationMode {
/// Do a quick and basic verification if possible.
Quick,
/// Do a full verification.
Full
}

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@ -17,10 +17,29 @@ pub struct OutOfBounds<T: fmt::Debug> {
#[derive(Debug)]
pub enum BlockError {
TooManyUncles,
TooManyUncles(OutOfBounds<usize>),
UncleWrongGeneration,
ExtraDataOutOfBounds(OutOfBounds<usize>),
InvalidSealArity(Mismatch<usize>),
TooMuchGasUsed(OutOfBounds<U256>),
InvalidUnclesHash(Mismatch<H256>),
UncleTooOld(OutOfBounds<U256>),
UncleIsBrother(OutOfBounds<U256>),
UncleInChain(H256),
UncleParentNotInChain(H256),
InvalidStateRoot,
InvalidGasUsed,
InvalidTransactionsRoot(Mismatch<H256>),
InvalidDifficulty(Mismatch<U256>),
InvalidGasLimit(OutOfBounds<U256>),
InvalidReceiptsStateRoot,
InvalidTimestamp(OutOfBounds<U256>),
InvalidLogBloom,
InvalidBlockNonce,
InvalidParentHash(Mismatch<H256>),
InvalidNumber(OutOfBounds<U256>),
UnknownParent(H256),
UnknownUncleParent(H256),
}
#[derive(Debug)]

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@ -2,7 +2,6 @@ use common::*;
use block::*;
use spec::*;
use engine::*;
use verification::*;
/// Engine using Ethash proof-of-work consensus algorithm, suitable for Ethereum
/// mainnet chains in the Olympic, Frontier and Homestead eras.
@ -27,53 +26,45 @@ impl Engine for Ethash {
block.state_mut().add_balance(&a, &decode(&self.spec().engine_params.get("blockReward").unwrap()));
}
fn verify_block(&self, mode: VerificationMode, header: &Header, parent: Option<&Header>, block: Option<&[u8]>) -> Result<(), VerificationError> {
if mode == VerificationMode::Quick {
fn verify_block_basic(&self, header: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
let min_difficulty = decode(self.spec().engine_params.get("minimumDifficulty").unwrap());
if header.difficulty < min_difficulty {
return Err(VerificationError::block(
BlockVerificationError::InvalidDifficulty { required: min_difficulty, got: header.difficulty },
block.map(|b| b.to_vec())));
return Err(From::from(BlockError::InvalidDifficulty(Mismatch { expected: min_difficulty, found: header.difficulty })))
}
let min_gas_limit = decode(self.spec().engine_params.get("minGasLimit").unwrap());
if header.gas_limit < min_gas_limit {
return Err(VerificationError::block(
BlockVerificationError::InvalidGasLimit { min: min_gas_limit, max: From::from(0), got: header.gas_limit },
block.map(|b| b.to_vec())));
return Err(From::from(BlockError::InvalidGasLimit(OutOfBounds { min: min_gas_limit, max: From::from(0), found: header.gas_limit })));
}
let len: U256 = From::from(header.extra_data.len());
let maximum_extra_data_size: U256 = From::from(self.maximum_extra_data_size());
if header.number != From::from(0) && len > maximum_extra_data_size {
return Err(VerificationError::block(
BlockVerificationError::ExtraDataTooBig { required: maximum_extra_data_size, got: len },
block.map(|b| b.to_vec())));
let maximum_extra_data_size = self.maximum_extra_data_size();
if header.number != From::from(0) && header.extra_data.len() > maximum_extra_data_size {
return Err(From::from(BlockError::ExtraDataOutOfBounds(OutOfBounds { min: 0, max: maximum_extra_data_size, found: header.extra_data.len() })));
}
match parent {
Some(p) => {
// TODO: Verify seal (quick)
Ok(())
}
fn verify_block_unordered(&self, _header: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
// TODO: Verify seal (full)
Ok(())
}
fn verify_block_final(&self, header: &Header, parent: &Header, _block: Option<&[u8]>) -> Result<(), Error> {
// Check difficulty is correct given the two timestamps.
let expected_difficulty = self.calculate_difficuty(header, p);
let expected_difficulty = self.calculate_difficuty(header, parent);
if header.difficulty != expected_difficulty {
return Err(VerificationError::block(
BlockVerificationError::InvalidDifficulty { required: expected_difficulty, got: header.difficulty },
block.map(|b| b.to_vec())));
return Err(From::from(BlockError::InvalidDifficulty(Mismatch { expected: expected_difficulty, found: header.difficulty })))
}
let gas_limit_divisor = decode(self.spec().engine_params.get("gasLimitBoundDivisor").unwrap());
let min_gas = p.gas_limit - p.gas_limit / gas_limit_divisor;
let max_gas = p.gas_limit + p.gas_limit / gas_limit_divisor;
let min_gas = parent.gas_limit - parent.gas_limit / gas_limit_divisor;
let max_gas = parent.gas_limit + parent.gas_limit / gas_limit_divisor;
if header.gas_limit <= min_gas || header.gas_limit >= max_gas {
return Err(VerificationError::block(
BlockVerificationError::InvalidGasLimit { min: min_gas_limit, max: max_gas, got: header.gas_limit },
block.map(|b| b.to_vec())));
}
},
None => ()
}
// TODO: Verify seal
return Err(From::from(BlockError::InvalidGasLimit(OutOfBounds { min: min_gas, max: max_gas, found: header.gas_limit })));
}
Ok(())
}
fn verify_transaction(&self, _t: &Transaction, _header: &Header) -> Result<(), VerificationError> { Ok(()) }
fn verify_transaction(&self, _t: &Transaction, _header: &Header) -> Result<(), Error> { Ok(()) }
}
impl Ethash {
@ -120,12 +111,9 @@ fn on_close_block() {
let genesis_header = engine.spec().genesis_header();
let mut db = OverlayDB::new_temp();
engine.spec().ensure_db_good(&mut db);
assert!(SecTrieDB::new(&db, &genesis_header.state_root).contains(&address_from_hex("102e61f5d8f9bc71d0ad4a084df4e65e05ce0e1c")));
{
let s = State::from_existing(db.clone(), genesis_header.state_root.clone(), engine.account_start_nonce());
assert_eq!(s.balance(&address_from_hex("0000000000000000000000000000000000000001")), U256::from(1u64));
}
let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()]);
// let c = b.close();
let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), vec![]);
let b = b.close();
assert_eq!(b.state().balance(&Address::zero()), U256::from_str("4563918244F40000").unwrap());
}
// TODO: difficulty test

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@ -13,20 +13,11 @@
/// 4. Maintain sync by handling NewBlocks/NewHashes messages
///
use std::collections::{HashSet, HashMap};
use std::cmp::{min, max};
use util::*;
use std::mem::{replace};
use util::network::{PeerId, PacketId};
use util::hash::{H256, FixedHash};
use util::bytes::{Bytes};
use util::uint::{U256};
use util::rlp::{Rlp, UntrustedRlp, RlpStream, self};
use util::rlp::rlptraits::{Stream, View};
use util::rlp::rlperrors::DecoderError;
use util::sha3::Hashable;
use client::{BlockNumber, BlockChainClient, BlockStatus, QueueStatus, ImportResult};
use views::{HeaderView};
use header::{Header as BlockHeader};
use client::{BlockNumber, BlockChainClient, BlockStatus, QueueStatus, ImportResult};
use sync::range_collection::{RangeCollection, ToUsize, FromUsize};
use sync::io::SyncIo;
@ -66,6 +57,8 @@ const NODE_DATA_PACKET: u8 = 0x0e;
const GET_RECEIPTS_PACKET: u8 = 0x0f;
const RECEIPTS_PACKET: u8 = 0x10;
const NETWORK_ID: U256 = ONE_U256; //TODO: get this from parent
struct Header {
/// Header data
data: Bytes,
@ -164,6 +157,7 @@ pub struct ChainSync {
impl ChainSync {
/// Create a new instance of syncing strategy.
pub fn new() -> ChainSync {
ChainSync {
state: SyncState::NotSynced,
@ -240,7 +234,19 @@ impl ChainSync {
asking_blocks: Vec::new(),
};
trace!(target: "sync", "New peer (protocol: {}, network: {:?}, difficulty: {:?}, latest:{}, genesis:{})", peer.protocol_version, peer.network_id, peer.difficulty, peer.latest, peer.genesis);
trace!(target: "sync", "New peer {} (protocol: {}, network: {:?}, difficulty: {:?}, latest:{}, genesis:{})", peer_id, peer.protocol_version, peer.network_id, peer.difficulty, peer.latest, peer.genesis);
let chain_info = io.chain().chain_info();
if peer.genesis != chain_info.genesis_hash {
io.disable_peer(peer_id);
trace!(target: "sync", "Peer {} genesis hash not matched", peer_id);
return Ok(());
}
if peer.network_id != NETWORK_ID {
io.disable_peer(peer_id);
trace!(target: "sync", "Peer {} network id not matched", peer_id);
return Ok(());
}
let old = self.peers.insert(peer_id.clone(), peer);
if old.is_some() {
@ -380,6 +386,9 @@ impl ChainSync {
let h = header_rlp.as_raw().sha3();
trace!(target: "sync", "{} -> NewBlock ({})", peer_id, h);
let header_view = HeaderView::new(header_rlp.as_raw());
// TODO: Decompose block and add to self.headers and self.bodies instead
if header_view.number() == From::from(self.last_imported_block + 1) {
match io.chain().import_block(block_rlp.as_raw()) {
ImportResult::AlreadyInChain => {
trace!(target: "sync", "New block already in chain {:?}", h);
@ -405,6 +414,7 @@ impl ChainSync {
io.disable_peer(peer_id);
}
};
}
Ok(())
}
@ -448,9 +458,11 @@ impl ChainSync {
/// Called by peer when it is disconnecting
pub fn on_peer_aborting(&mut self, io: &mut SyncIo, peer: &PeerId) {
trace!(target: "sync", "== Disconnected {}", peer);
if self.peers.contains_key(&peer) {
self.clear_peer_download(peer);
self.continue_sync(io);
}
}
/// Called when a new peer is connected
pub fn on_peer_connected(&mut self, io: &mut SyncIo, peer: &PeerId) {
@ -768,7 +780,7 @@ impl ChainSync {
let mut packet = RlpStream::new_list(5);
let chain = io.chain().chain_info();
packet.append(&(PROTOCOL_VERSION as u32));
packet.append(&0u32); //TODO: network id
packet.append(&NETWORK_ID); //TODO: network id
packet.append(&chain.total_difficulty);
packet.append(&chain.best_block_hash);
packet.append(&chain.genesis_hash);

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@ -1,10 +1,11 @@
use client::BlockChainClient;
use util::network::{HandlerIo, PeerId, PacketId, Error as NetworkError};
use util::network::{HandlerIo, PeerId, PacketId,};
use util::error::UtilError;
pub trait SyncIo {
fn disable_peer(&mut self, peer_id: &PeerId);
fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>;
fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>;
fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError>;
fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError>;
fn chain<'s>(&'s mut self) -> &'s mut BlockChainClient;
}
@ -27,11 +28,11 @@ impl<'s, 'h> SyncIo for NetSyncIo<'s, 'h> {
self.network.disable_peer(*peer_id);
}
fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>{
fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError>{
self.network.respond(packet_id, data)
}
fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError>{
fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError>{
self.network.send(peer_id, packet_id, data)
}

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@ -4,7 +4,8 @@ use util::hash::{H256, FixedHash};
use util::uint::{U256};
use util::sha3::Hashable;
use util::rlp::{self, Rlp, RlpStream, View, Stream};
use util::network::{PeerId, PacketId, Error as NetworkError};
use util::network::{PeerId, PacketId};
use util::error::UtilError;
use client::{BlockChainClient, BlockStatus, BlockNumber, TreeRoute, BlockQueueStatus, BlockChainInfo, ImportResult, QueueStatus};
use header::Header as BlockHeader;
use sync::io::SyncIo;
@ -195,7 +196,7 @@ impl<'p> SyncIo for TestIo<'p> {
fn disable_peer(&mut self, _peer_id: &PeerId) {
}
fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError> {
fn respond(&mut self, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError> {
self.queue.push_back(TestPacket {
data: data,
packet_id: packet_id,
@ -204,7 +205,7 @@ impl<'p> SyncIo for TestIo<'p> {
Ok(())
}
fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), NetworkError> {
fn send(&mut self, peer_id: PeerId, packet_id: PacketId, data: Vec<u8>) -> Result<(), UtilError> {
self.queue.push_back(TestPacket {
data: data,
packet_id: packet_id,

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@ -1,157 +1,139 @@
use util::*;
use header::Header;
use common::*;
use client::BlockNumber;
use engine::{Engine, VerificationMode};
use views::BlockView;
use engine::Engine;
use blockchain::BlockChain;
#[derive(Debug)]
pub struct VerificationError {
pub block: Option<Bytes>,
pub error: VerificationErrorOption,
}
impl VerificationError {
pub fn block(error: BlockVerificationError, block: Option<Bytes>) -> VerificationError {
VerificationError {
block: block,
error: VerificationErrorOption::Block(error),
}
}
pub fn transaction(error: TransactionVerificationError, block: Option<Bytes>) -> VerificationError {
VerificationError {
block: block,
error: VerificationErrorOption::Transaction(error),
}
}
}
#[derive(Debug)]
pub enum VerificationErrorOption {
Transaction(TransactionVerificationError),
Block(BlockVerificationError),
}
#[derive(Debug)]
pub enum TransactionVerificationError {
OutOfGasBase,
OutOfGasIntrinsic,
NotEnoughCash,
GasPriceTooLow,
BlockGasLimitReached,
FeeTooSmall,
TooMuchGasUsed {
used: U256,
limit: U256
},
InvalidSignature,
InvalidTransactionFormat,
}
#[derive(Debug)]
pub enum BlockVerificationError {
TooMuchGasUsed {
used: U256,
limit: U256,
},
InvalidBlockFormat,
ExtraDataTooBig {
required: U256,
got: U256,
},
InvalidUnclesHash {
required: H256,
got: H256,
},
TooManyUncles,
UncleTooOld,
UncleIsBrother,
UncleInChain,
UncleParentNotInChain,
InvalidStateRoot,
InvalidGasUsed,
InvalidTransactionsRoot {
required: H256,
got: H256,
},
InvalidDifficulty {
required: U256,
got: U256,
},
InvalidGasLimit {
min: U256,
max: U256,
got: U256,
},
InvalidReceiptsStateRoot,
InvalidTimestamp,
InvalidLogBloom,
InvalidNonce,
InvalidBlockHeaderItemCount,
InvalidBlockNonce,
InvalidParentHash,
InvalidUncleParentHash,
InvalidNumber,
BlockNotFound,
UnknownParent,
}
pub fn verify_header(header: &Header) -> Result<(), BlockVerificationError> {
fn verify_header(header: &Header) -> Result<(), Error> {
if header.number > From::from(BlockNumber::max_value()) {
return Err(BlockVerificationError::InvalidNumber)
return Err(From::from(BlockError::InvalidNumber(OutOfBounds { max: From::from(BlockNumber::max_value()), min: From::from(0), found: header.number })))
}
if header.gas_used > header.gas_limit {
return Err(BlockVerificationError::TooMuchGasUsed {
used: header.gas_used,
limit: header.gas_limit,
});
return Err(From::from(BlockError::TooMuchGasUsed(OutOfBounds { max: header.gas_limit, min: From::from(0), found: header.gas_used })));
}
Ok(())
}
pub fn verify_parent(header: &Header, parent: &Header) -> Result<(), BlockVerificationError> {
fn verify_parent(header: &Header, parent: &Header) -> Result<(), Error> {
if !header.parent_hash.is_zero() && parent.hash() != header.parent_hash {
return Err(BlockVerificationError::InvalidParentHash)
return Err(From::from(BlockError::InvalidParentHash(Mismatch { expected: parent.hash(), found: header.parent_hash.clone() })))
}
if header.timestamp <= parent.timestamp {
return Err(BlockVerificationError::InvalidTimestamp)
return Err(From::from(BlockError::InvalidTimestamp(OutOfBounds { max: BAD_U256, min: parent.timestamp + From::from(1), found: header.timestamp })))
}
if header.number <= parent.number {
return Err(BlockVerificationError::InvalidNumber)
return Err(From::from(BlockError::InvalidNumber(OutOfBounds { max: From::from(BlockNumber::max_value()), min: parent.number + From::from(1), found: header.number })));
}
Ok(())
}
pub fn verify_block_integrity(block: &[u8], transactions_root: &H256, uncles_hash: &H256) -> Result<(), BlockVerificationError> {
fn verify_block_integrity(block: &[u8], transactions_root: &H256, uncles_hash: &H256) -> Result<(), Error> {
let block = Rlp::new(block);
let tx = block.at(1);
let expected_root = ordered_trie_root(tx.iter().map(|r| r.as_raw().to_vec()).collect()); //TODO: get rid of vectors here
if &expected_root != transactions_root {
return Err(BlockVerificationError::InvalidTransactionsRoot {
required: expected_root.clone(),
got: transactions_root.clone(),
});
let expected_root = &ordered_trie_root(tx.iter().map(|r| r.as_raw().to_vec()).collect()); //TODO: get rid of vectors here
if expected_root != transactions_root {
return Err(From::from(BlockError::InvalidTransactionsRoot(Mismatch { expected: expected_root.clone(), found: transactions_root.clone() })))
}
let expected_uncles = block.at(2).as_raw().sha3();
if &expected_uncles != uncles_hash {
return Err(BlockVerificationError::InvalidUnclesHash {
required: expected_uncles.clone(),
got: uncles_hash.clone(),
});
let expected_uncles = &block.at(2).as_raw().sha3();
if expected_uncles != uncles_hash {
return Err(From::from(BlockError::InvalidUnclesHash(Mismatch { expected: expected_uncles.clone(), found: uncles_hash.clone() })))
}
Ok(())
}
pub fn verify_block_basic(bytes: &[u8], parent: &Header, engine: &mut Engine) -> Result<(), BlockVerificationError> {
pub fn verify_block_basic(bytes: &[u8], engine: &mut Engine) -> Result<(), Error> {
let block = BlockView::new(bytes);
let header = block.header();
try!(verify_header(&header));
try!(verify_parent(&header, parent));
try!(verify_block_integrity(bytes, &header.transactions_root, &header.uncles_hash));
try!(engine.verify_block_basic(&header, Some(bytes)));
for u in Rlp::new(bytes).at(2).iter().map(|rlp| rlp.as_val::<Header>()) {
try!(verify_header(&u));
try!(engine.verify_block_basic(&u, None));
}
Ok(())
}
pub fn verify_block_unordered(block: &[u8]) -> Result<(), BlockVerificationError> {
pub fn verify_block_unordered(bytes: &[u8], engine: &mut Engine) -> Result<(), Error> {
let block = BlockView::new(bytes);
let header = block.header();
try!(engine.verify_block_unordered(&header, Some(bytes)));
for u in Rlp::new(bytes).at(2).iter().map(|rlp| rlp.as_val::<Header>()) {
try!(engine.verify_block_unordered(&u, None));
}
Ok(())
}
pub fn verify_block_final(bytes: &[u8], engine: &mut Engine, bc: &BlockChain) -> Result<(), Error> {
let block = BlockView::new(bytes);
let header = block.header();
let parent = try!(bc.block_header(&header.parent_hash).ok_or::<Error>(From::from(BlockError::UnknownParent(header.parent_hash.clone()))));
try!(verify_parent(&header, &parent));
try!(engine.verify_block_final(&header, &parent, Some(bytes)));
let num_uncles = Rlp::new(bytes).at(2).item_count();
if num_uncles != 0 {
if num_uncles > 2 {
return Err(From::from(BlockError::TooManyUncles(OutOfBounds { min: 0, max: 2, found: num_uncles })));
}
let mut excluded = HashSet::new();
excluded.insert(header.hash());
let mut hash = header.parent_hash.clone();
excluded.insert(hash.clone());
for _ in 0..6 {
match bc.block_details(&hash) {
Some(details) => {
excluded.insert(details.parent.clone());
let b = bc.block(&hash).unwrap();
excluded.extend(BlockView::new(&b).uncle_hashes());
hash = details.parent;
}
None => break
}
}
for uncle in Rlp::new(bytes).at(2).iter().map(|rlp| rlp.as_val::<Header>()) {
let uncle_parent = try!(bc.block_header(&uncle.parent_hash).ok_or::<Error>(From::from(BlockError::UnknownUncleParent(uncle.parent_hash.clone()))));
if excluded.contains(&uncle_parent.hash()) {
return Err(From::from(BlockError::UncleInChain(uncle_parent.hash())))
}
// m_currentBlock.number() - uncle.number() m_cB.n - uP.n()
// 1 2
// 2
// 3
// 4
// 5
// 6 7
// (8 Invalid)
let depth = if header.number > uncle.number { header.number - uncle.number } else { From::from(0) };
if depth > From::from(6) {
return Err(From::from(BlockError::UncleTooOld(OutOfBounds { min: header.number - depth, max: header.number - From::from(1), found: uncle.number })));
}
else if depth < From::from(1) {
return Err(From::from(BlockError::UncleIsBrother(OutOfBounds { min: header.number - depth, max: header.number - From::from(1), found: uncle.number })));
}
// cB
// cB.p^1 1 depth, valid uncle
// cB.p^2 ---/ 2
// cB.p^3 -----/ 3
// cB.p^4 -------/ 4
// cB.p^5 ---------/ 5
// cB.p^6 -----------/ 6
// cB.p^7 -------------/
// cB.p^8
let mut expected_uncle_parent = header.parent_hash.clone();
for _ in 0..depth.as_u32() {
expected_uncle_parent = bc.block_details(&expected_uncle_parent).unwrap().parent;
}
if expected_uncle_parent != uncle_parent.hash() {
return Err(From::from(BlockError::UncleParentNotInChain(uncle_parent.hash())));
}
try!(engine.verify_block_final(&uncle, &uncle_parent, Some(bytes)));
}
}
Ok(())
}