Merge branch 'network' into verification

src/bin/client.rs

@@ -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();

src/engine.rs

@@ -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
-}

src/error.rs

@@ -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)]

src/ethereum/ethash.rs

@@ -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(
+			return Err(From::from(BlockError::InvalidDifficulty(Mismatch { expected: min_difficulty, found: header.difficulty })))
-					BlockVerificationError::InvalidDifficulty { required: min_difficulty, got: header.difficulty }, 
-					block.map(|b| b.to_vec())));
 		}
 		let min_gas_limit = decode(self.spec().engine_params.get("minGasLimit").unwrap());
 		if header.gas_limit < min_gas_limit {
-				return Err(VerificationError::block(
+			return Err(From::from(BlockError::InvalidGasLimit(OutOfBounds { min: min_gas_limit, max: From::from(0), found: header.gas_limit }))); 
-					BlockVerificationError::InvalidGasLimit { min: min_gas_limit, max: From::from(0), got: header.gas_limit }, 
-					block.map(|b| b.to_vec())));
 		}
-			let len: U256 = From::from(header.extra_data.len());
+		let maximum_extra_data_size = self.maximum_extra_data_size();
-			let maximum_extra_data_size: U256 = From::from(self.maximum_extra_data_size());
+		if header.number != From::from(0) && header.extra_data.len() > maximum_extra_data_size {
-			if header.number != From::from(0) && len > maximum_extra_data_size {
+			return Err(From::from(BlockError::ExtraDataOutOfBounds(OutOfBounds { min: 0, max: maximum_extra_data_size, found: header.extra_data.len() }))); 
-				return Err(VerificationError::block(
-					BlockVerificationError::ExtraDataTooBig { required: maximum_extra_data_size, got: len }, 
-					block.map(|b| b.to_vec())));
 		}
-			match parent {
+		// TODO: Verify seal (quick)
-				Some(p) => {
+		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(
+			return Err(From::from(BlockError::InvalidDifficulty(Mismatch { expected: expected_difficulty, found: header.difficulty })))
-							BlockVerificationError::InvalidDifficulty { required: expected_difficulty, got: header.difficulty }, 
-							block.map(|b| b.to_vec())));
 		}
 		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 min_gas = parent.gas_limit - parent.gas_limit / gas_limit_divisor;
-					let max_gas = p.gas_limit + p.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(
+			return Err(From::from(BlockError::InvalidGasLimit(OutOfBounds { min: min_gas, max: max_gas, found: header.gas_limit }))); 
-							BlockVerificationError::InvalidGasLimit { min: min_gas_limit, max: max_gas, got: header.gas_limit }, 
-							block.map(|b| b.to_vec())));
-					}
-				},
-				None => ()
-			}
-			// TODO: Verify seal
 		}
 		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 b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), vec![]);
-	{
+	let b = b.close();
-		let s = State::from_existing(db.clone(), genesis_header.state_root.clone(), engine.account_start_nonce());
+	assert_eq!(b.state().balance(&Address::zero()), U256::from_str("4563918244F40000").unwrap());
-		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();
 }
 
+// TODO: difficulty test

src/sync/chain.rs

@@ -13,20 +13,11 @@
 /// 4. Maintain sync by handling NewBlocks/NewHashes messages
 ///
 
-use std::collections::{HashSet, HashMap};
+use util::*;
-use std::cmp::{min, max};
 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);

src/sync/io.rs

@@ -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 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<(), NetworkError>;
+	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)
 	}
 

src/sync/tests.rs

@@ -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,

src/verification.rs

@@ -1,157 +1,139 @@
-use util::*;
+use common::*;
-use header::Header;
 use client::BlockNumber;
-use engine::{Engine, VerificationMode};
+use engine::Engine;
-use views::BlockView;
+use blockchain::BlockChain;
 
-#[derive(Debug)]
+fn verify_header(header: &Header) -> Result<(), Error> {
-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> {
 	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 {
+		return Err(From::from(BlockError::TooMuchGasUsed(OutOfBounds { max: header.gas_limit, min: From::from(0), found: header.gas_used })));
-			used: header.gas_used,
-			limit: header.gas_limit,
-		});
 	}
 	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
+	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 {
+	if expected_root != transactions_root {
-		return Err(BlockVerificationError::InvalidTransactionsRoot {
+		return Err(From::from(BlockError::InvalidTransactionsRoot(Mismatch { expected: expected_root.clone(), found: transactions_root.clone() })))
-			required: expected_root.clone(),
-			got: transactions_root.clone(),
-		});
 	}
-	let expected_uncles = block.at(2).as_raw().sha3();
+	let expected_uncles = &block.at(2).as_raw().sha3();
-	if &expected_uncles != uncles_hash {
+	if expected_uncles != uncles_hash {
-		return Err(BlockVerificationError::InvalidUnclesHash {
+		return Err(From::from(BlockError::InvalidUnclesHash(Mismatch { expected: expected_uncles.clone(), found: uncles_hash.clone() })))
-			required: expected_uncles.clone(),
-			got: 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(())
 }