Support Homestead,

src/blockchain.rs

@@ -252,8 +252,7 @@ impl BlockChain {
 	/// If it doesn't, then rewind down until we find one that does and delete data to ensure that
 	/// later blocks will be reimported. 
 	pub fn ensure_good(&mut self, _state: &OverlayDB) {
-		info!("Rescuing database.");
-		// TODO.
+		unimplemented!();
 	}
 
 	/// Returns a tree route between `from` and `to`, which is a tuple of:

src/client.rs

@@ -138,7 +138,7 @@ impl Client {
 		engine.spec().ensure_db_good(&mut state_db);
 		state_db.commit().expect("Error commiting genesis state to state DB");
 
-		chain.write().unwrap().ensure_good(&state_db);
+//		chain.write().unwrap().ensure_good(&state_db);
 
 		Ok(Client {
 			chain: chain,

src/engine.rs

@@ -50,6 +50,7 @@ pub trait Engine : Sync + Send {
 	/// Additional verification for transactions in blocks.
 	// TODO: Add flags for which bits of the transaction to check.
 	// TODO: consider including State in the params.
+	fn verify_transaction_basic(&self, _t: &Transaction, _header: &Header) -> Result<(), Error> { Ok(()) }
 	fn verify_transaction(&self, _t: &Transaction, _header: &Header) -> Result<(), Error> { Ok(()) }
 
 	/// Don't forget to call Super::populateFromParent when subclassing & overriding.

src/ethereum/ethash.rs

@@ -8,14 +8,28 @@ use evm::Schedule;
 /// mainnet chains in the Olympic, Frontier and Homestead eras.
 pub struct Ethash {
 	spec: Spec,
+	u64_params: RwLock<HashMap<String, u64>>,
+	u256_params: RwLock<HashMap<String, U256>>,
 }
 
 impl Ethash {
 	pub fn new_boxed(spec: Spec) -> Box<Engine> {
-		Box::new(Ethash{spec: spec})
+		Box::new(Ethash{
+			spec: spec,
+			u64_params: RwLock::new(HashMap::new()),
+			u256_params: RwLock::new(HashMap::new()),
+		})
 	}
 
-	fn u256_param(&self, name: &str) -> U256 { self.spec().engine_params.get(name).map(|a| decode(&a)).unwrap_or(U256::from(0u64)) }
+	fn u64_param(&self, name: &str) -> u64 {
+		*self.u64_params.write().unwrap().entry("name".to_string()).or_insert_with(||
+			self.spec().engine_params.get(name).map(|a| decode(&a)).unwrap_or(0u64))
+	}
+
+	fn u256_param(&self, name: &str) -> U256 {
+		*self.u256_params.write().unwrap().entry("name".to_string()).or_insert_with(||
+			self.spec().engine_params.get(name).map(|a| decode(&a)).unwrap_or(x!(0)))
+	}
 }
 
 impl Engine for Ethash {
@@ -29,7 +43,12 @@ impl Engine for Ethash {
 	/// Additional engine-specific information for the user/developer concerning `header`.
 	fn extra_info(&self, _header: &Header) -> HashMap<String, String> { HashMap::new() }
 	fn spec(&self) -> &Spec { &self.spec }
-	fn schedule(&self, _env_info: &EnvInfo) -> Schedule { Schedule::new_frontier() }
+	fn schedule(&self, env_info: &EnvInfo) -> Schedule {
+		match env_info.number < self.u64_param("frontierCompatibilityModeLimit") {
+			true => Schedule::new_frontier(),
+			_ => Schedule::new_homestead(),
+		}
+	}
 
 	fn populate_from_parent(&self, header: &mut Header, parent: &Header) {
 		header.difficulty = self.calculate_difficuty(header, parent);
@@ -70,6 +89,7 @@ impl Engine for Ethash {
 			return Err(From::from(BlockError::InvalidDifficulty(Mismatch { expected: min_difficulty, found: header.difficulty })))
 		}
 		// TODO: Verify seal (quick)
+
 		Ok(())
 	}
 
@@ -93,7 +113,12 @@ impl Engine for Ethash {
 		Ok(())
 	}
 
-	fn verify_transaction(&self, _t: &Transaction, _header: &Header) -> result::Result<(), Error> { Ok(()) }
+	fn verify_transaction_basic(&self, t: &Transaction, header: &Header) -> result::Result<(), Error> {
+		if header.number() >= self.u64_param("frontierCompatibilityModeLimit") {
+			try!(t.check_low_s());
+		}
+		Ok(())
+	}
 }
 
 impl Ethash {
@@ -103,10 +128,10 @@ impl Ethash {
 			panic!("Can't calculate genesis block difficulty");
 		}
 
-		let min_difficulty = decode(self.spec().engine_params.get("minimumDifficulty").unwrap());
-		let difficulty_bound_divisor = decode(self.spec().engine_params.get("difficultyBoundDivisor").unwrap());
-		let duration_limit: u64 = decode(self.spec().engine_params.get("durationLimit").unwrap());
-		let frontier_limit = decode(self.spec().engine_params.get("frontierCompatibilityModeLimit").unwrap());
+		let min_difficulty = self.u256_param("minimumDifficulty");
+		let difficulty_bound_divisor = self.u256_param("difficultyBoundDivisor");
+		let duration_limit = self.u64_param("durationLimit");
+		let frontier_limit = self.u64_param("frontierCompatibilityModeLimit");
 		let mut target = if header.number < frontier_limit {
 			if header.timestamp >= parent.timestamp + duration_limit {
 				parent.difficulty - (parent.difficulty / difficulty_bound_divisor) 

src/service.rs

@@ -38,7 +38,8 @@ struct ClientIoHandler {
 }
 
 impl IoHandler<NetSyncMessage> for ClientIoHandler {
-	fn initialize<'s>(&'s mut self, _io: &mut IoContext<'s, NetSyncMessage>) { }
+	fn initialize<'s>(&'s mut self, _io: &mut IoContext<'s, NetSyncMessage>) {
+	}
 
 	fn message<'s>(&'s mut self, _io: &mut IoContext<'s, NetSyncMessage>, net_message: &'s mut NetSyncMessage) {
 		match net_message {

src/transaction.rs

@@ -215,6 +215,15 @@ impl Transaction {
 		Self::gas_required_for(match self.action{Action::Create=>true, Action::Call(_)=>false}, &self.data, schedule)
 	}
 
+	/// Checks whether the signature has a low 's' value.
+	pub fn check_low_s(&self) -> Result<(), Error> {
+		if !ec::is_low_s(&self.s) {
+			Err(Error::Util(UtilError::Crypto(CryptoError::InvalidSignature)))
+		} else {
+			Ok(())
+		}
+	}
+
 	/// Do basic validation, checking for valid signature and minimum gas,
 	pub fn validate(self, schedule: &Schedule, require_low: bool) -> Result<Transaction, Error> {
 		if require_low && !ec::is_low_s(&self.s) {

src/verification.rs

@@ -18,6 +18,12 @@ pub fn verify_block_basic(header: &Header, bytes: &[u8], engine: &Engine) -> Res
 		try!(verify_header(&u, engine));
 		try!(engine.verify_block_basic(&u, None));
 	}
+	// Verify transactions.
+	// TODO: either use transaction views or cache the decoded transactions.
+	let v = BlockView::new(bytes);
+	for t in v.transactions() {
+		try!(engine.verify_transaction_basic(&t, &header));
+	}
 	Ok(())
 }
 
@@ -29,6 +35,12 @@ pub fn verify_block_unordered(header: &Header, bytes: &[u8], engine: &Engine) ->
 	for u in Rlp::new(bytes).at(2).iter().map(|rlp| rlp.as_val::<Header>()) {
 		try!(engine.verify_block_unordered(&u, None));
 	}
+	// Verify transactions.
+	// TODO: pass in pre-recovered transactions - maybe verify_transaction wants to call `sender()`.
+	let v = BlockView::new(bytes);
+	for t in v.transactions() {
+		try!(engine.verify_transaction(&t, &header));
+	}
 	Ok(())
 }
 

src/views.rs

@@ -2,7 +2,57 @@
 use util::*;
 use header::*;
 use transaction::*;
+/*
+/// View onto block rlp.
+pub struct TransactionView<'a> {
+	rlp: Rlp<'a>
+}
 
+impl<'a> TransactionView<'a> {
+	/// Creates new view onto block from raw bytes.
+	pub fn new(bytes: &'a [u8]) -> TransactionView<'a> {
+		BlockView {
+			rlp: Rlp::new(bytes)
+		}
+	}
+
+	/// Creates new view onto block from rlp.
+	pub fn new_from_rlp(rlp: Rlp<'a>) -> TransactionView<'a> {
+		TransactionView {
+			rlp: rlp
+		}
+	}
+
+	/// Return reference to underlaying rlp.
+	pub fn rlp(&self) -> &Rlp<'a> {
+		&self.rlp
+	}
+
+	pub fn nonce(&self) -> U256 { self.rlp.val_at(0) }
+
+	pub fn gas_price(&self) -> U256 { self.rlp.val_at(1) }
+
+	pub fn gas(&self) -> U256 { self.rlp.val_at(2) }
+
+	pub fn action(&self) -> Action { self.rlp.val_at(3) }
+
+	pub fn value(&self) -> U256 { self.rlp.val_at(4) }
+
+	pub fn data(&self) -> Bytes { self.rlp.val_at(5) }
+
+	pub fn v(&self) -> u8 { self.rlp.val_at(6) }
+
+	pub fn r(&self) -> U256 { self.rlp.val_at(7) }
+
+	pub fn s(&self) -> U256 { self.rlp.val_at(8) }
+}
+
+impl<'a> Hashable for TransactionView<'a> {
+	fn sha3(&self) -> H256 {
+		self.rlp.as_raw().sha3()
+	}
+}
+*/
 /// View onto block rlp.
 pub struct BlockView<'a> {
 	rlp: Rlp<'a>
@@ -37,7 +87,12 @@ impl<'a> BlockView<'a> {
 	pub fn header_view(&self) -> HeaderView<'a> {
 		HeaderView::new_from_rlp(self.rlp.at(0))
 	}
-
+/*
+	/// Return List of transactions in given block.
+	pub fn transactions(&self) -> Vec<TransactionView> {
+		self.rlp.at(1).iter().map(|rlp| TransactionView::new_from_rlp(rlp)).collect()
+	}
+*/
 	/// Return List of transactions in given block.
 	pub fn transactions(&self) -> Vec<Transaction> {
 		self.rlp.val_at(1)