compare genesis during peering handshake (#327)

* wip - send genesis in handshake
* error if genesis mismatch on handshake
* fix the tests
* preserve order of existing fields in hand/shake

chain/src/chain.rs

@@ -72,7 +72,7 @@ impl Chain {
 	pub fn init(
 		db_root: String,
 		adapter: Arc<ChainAdapter>,
-		gen_block: Option<Block>,
+		genesis: Block,
 		pow_verifier: fn(&BlockHeader, u32) -> bool,
 	) -> Result<Chain, Error> {
 		let chain_store = store::ChainKVStore::new(db_root.clone())?;
@@ -81,29 +81,30 @@ impl Chain {
 		let head = match chain_store.head() {
 			Ok(tip) => tip,
 			Err(NotFoundErr) => {
-				if let None = gen_block {
-					return Err(Error::GenesisBlockRequired);
-				}
-
-				let gen = gen_block.unwrap();
-				chain_store.save_block(&gen)?;
-				chain_store.setup_height(&gen.header)?;
+				chain_store.save_block(&genesis)?;
+				chain_store.setup_height(&genesis.header)?;
 
 				// saving a new tip based on genesis
-				let tip = Tip::new(gen.hash());
+				let tip = Tip::new(genesis.hash());
 				chain_store.save_head(&tip)?;
 				info!(
 					LOGGER,
-					"Saved genesis block with hash: {:?}, nonce: {:?}, pow: {:?}",
-					gen.hash(),
-					gen.header.nonce,
-					gen.header.pow,
+					"Saved genesis block: {:?}, nonce: {:?}, pow: {:?}",
+					genesis.hash(),
+					genesis.header.nonce,
+					genesis.header.pow,
 				);
 				tip
 			}
 			Err(e) => return Err(Error::StoreErr(e, "chain init load head".to_owned())),
 		};
 
+		info!(
+			LOGGER,
+			"Chain init: {:?}",
+			head,
+		);
+
 		let store = Arc::new(chain_store);
 		let sumtrees = sumtree::SumTrees::open(db_root, store.clone())?;
 

chain/tests/mine_simple_chain.rs

@@ -44,10 +44,7 @@ fn setup(dir_name: &str) -> Chain {
 	let _ = env_logger::init();
 	clean_output_dir(dir_name);
 	global::set_mining_mode(ChainTypes::AutomatedTesting);
-	let mut genesis_block = None;
-	if !chain::Chain::chain_exists(dir_name.to_string()) {
-		genesis_block = pow::mine_genesis_block(None);
-	}
+	let genesis_block = pow::mine_genesis_block(None).unwrap();
 	chain::Chain::init(
 		dir_name.to_string(),
 		Arc::new(NoopAdapter {}),

chain/tests/test_coinbase_maturity.rs

@@ -44,10 +44,8 @@ fn test_coinbase_maturity() {
 	clean_output_dir(".grin");
 	global::set_mining_mode(ChainTypes::AutomatedTesting);
 
-	let mut genesis_block = None;
-	if !chain::Chain::chain_exists(".grin".to_string()) {
-		genesis_block = pow::mine_genesis_block(None);
-	}
+	let genesis_block = pow::mine_genesis_block(None).unwrap();
+
 	let chain = chain::Chain::init(
 		".grin".to_string(),
 		Arc::new(NoopAdapter {}),

grin/src/server.rs

@@ -89,20 +89,20 @@ impl Server {
 
 		let chain_adapter = Arc::new(ChainToPoolAndNetAdapter::new(tx_pool.clone()));
 
-		let mut genesis_block = None;
-		if !chain::Chain::chain_exists(config.db_root.clone()) {
-      let chain_type = config.chain_type.clone();
-      if chain_type == global::ChainTypes::Testnet1 {
-        genesis_block = Some(genesis::genesis_testnet1());
-      } else {
-			  genesis_block = pow::mine_genesis_block(config.mining_config.clone());
-      }
-		}
+		let genesis = match config.chain_type {
+			global::ChainTypes::Testnet1 => genesis::genesis_testnet1(),
+			_ => pow::mine_genesis_block(config.mining_config.clone())?,
+		};
+		info!(
+			LOGGER,
+			"Starting server, genesis block: {}",
+			genesis.hash(),
+		);
 
 		let shared_chain = Arc::new(chain::Chain::init(
 			config.db_root.clone(),
 			chain_adapter.clone(),
-			genesis_block,
+			genesis.clone(),
 			pow::verify_size,
 		)?);
 
@@ -114,11 +114,14 @@ impl Server {
 			tx_pool.clone(),
 			peer_store.clone(),
 		));
+
 		let p2p_server = Arc::new(p2p::Server::new(
 			config.capabilities,
 			config.p2p_config.unwrap(),
 			net_adapter.clone(),
+			genesis.hash(),
 		));
+
 		chain_adapter.init(p2p_server.clone());
 		pool_net_adapter.init(p2p_server.clone());
 

grin/src/types.rs

@@ -36,6 +36,7 @@ pub enum Error {
 	API(api::Error),
 	/// Error originating from wallet API.
 	Wallet(wallet::Error),
+	Cuckoo(pow::cuckoo::Error),
 }
 
 impl From<chain::Error> for Error {
@@ -50,6 +51,12 @@ impl From<p2p::Error> for Error {
 	}
 }
 
+impl From<pow::cuckoo::Error> for Error {
+	fn from(e: pow::cuckoo::Error) -> Error {
+		Error::Cuckoo(e)
+	}
+}
+
 impl From<store::Error> for Error {
 	fn from(e: store::Error) -> Error {
 		Error::Store(e)

p2p/src/handshake.rs

@@ -22,7 +22,7 @@ use rand::os::OsRng;
 use tokio_core::net::TcpStream;
 
 use core::core::target::Difficulty;
-use core::ser;
+use core::core::hash::Hash;
 use msg::*;
 use types::*;
 use protocol::ProtocolV1;
@@ -36,6 +36,9 @@ pub struct Handshake {
 	/// Ring buffer of nonces sent to detect self connections without requiring
 	/// a node id.
 	nonces: Arc<RwLock<VecDeque<u64>>>,
+	/// The genesis block header of the chain seen by this node.
+	/// We only want to connect to other nodes seeing the same chain (forks are ok).
+	genesis: Hash,
 }
 
 unsafe impl Sync for Handshake {}
@@ -43,9 +46,10 @@ unsafe impl Send for Handshake {}
 
 impl Handshake {
 	/// Creates a new handshake handler
-	pub fn new() -> Handshake {
+	pub fn new(genesis: Hash) -> Handshake {
 		Handshake {
 			nonces: Arc::new(RwLock::new(VecDeque::with_capacity(NONCES_CAP))),
+			genesis: genesis,
 		}
 	}
 
@@ -64,34 +68,35 @@ impl Handshake {
 			Ok(pa) => pa,
 			Err(e) => return Box::new(futures::future::err(Error::Connection(e))),
 		};
-		debug!(
-			LOGGER,
-			"handshake connect with nonce - {}, sender - {:?}, receiver - {:?}",
-			nonce,
-			self_addr,
-			peer_addr,
-		);
 
 		let hand = Hand {
 			version: PROTOCOL_VERSION,
 			capabilities: capab,
 			nonce: nonce,
+			genesis: self.genesis,
 			total_difficulty: total_difficulty,
 			sender_addr: SockAddr(self_addr),
 			receiver_addr: SockAddr(peer_addr),
 			user_agent: USER_AGENT.to_string(),
 		};
 
+		let genesis = self.genesis;
+
 		// write and read the handshake response
 		Box::new(
 			write_msg(conn, hand, Type::Hand)
 				.and_then(|conn| read_msg::<Shake>(conn))
 				.and_then(move |(conn, shake)| {
-					if shake.version != 1 {
-						Err(Error::Serialization(ser::Error::UnexpectedData {
-							expected: vec![PROTOCOL_VERSION as u8],
-							received: vec![shake.version as u8],
-						}))
+					if shake.version != PROTOCOL_VERSION {
+						Err(Error::ProtocolMismatch {
+							us: PROTOCOL_VERSION,
+							peer: shake.version,
+						})
+					} else if shake.genesis != genesis {
+						Err(Error::GenesisMismatch {
+							us: genesis,
+							peer: shake.genesis,
+						})
 					} else {
 						let peer_info = PeerInfo {
 							capabilities: shake.capabilities,
@@ -102,6 +107,7 @@ impl Handshake {
 						};
 
 						info!(LOGGER, "Connected to peer {:?}", peer_info);
+
 						// when more than one protocol version is supported, choosing should go here
 						Ok((conn, ProtocolV1::new(), peer_info))
 					}
@@ -118,30 +124,25 @@ impl Handshake {
 		conn: TcpStream,
 	) -> Box<Future<Item = (TcpStream, ProtocolV1, PeerInfo), Error = Error>> {
 		let nonces = self.nonces.clone();
+		let genesis = self.genesis.clone();
 		Box::new(
 			read_msg::<Hand>(conn)
 				.and_then(move |(conn, hand)| {
-					if hand.version != 1 {
-						return Err(Error::Serialization(ser::Error::UnexpectedData {
-							expected: vec![PROTOCOL_VERSION as u8],
-							received: vec![hand.version as u8],
-						}));
-					}
-					{
-						// check the nonce to see if we could be trying to connect to ourselves
+					if hand.version != PROTOCOL_VERSION {
+						return Err(Error::ProtocolMismatch {
+							us: PROTOCOL_VERSION,
+							peer: hand.version,
+						});
+					} else if hand.genesis != genesis {
+						return Err(Error::GenesisMismatch {
+							us: genesis,
+							peer: hand.genesis,
+						});
+					} else {
+						// check the nonce to see if we are trying to connect to ourselves
 						let nonces = nonces.read().unwrap();
-						debug!(
-							LOGGER,
-							"checking the nonce - {}, {:?}",
-							&hand.nonce,
-							nonces,
-						);
 						if nonces.contains(&hand.nonce) {
-							debug!(LOGGER, "***** nonce matches! Avoiding connecting to ourselves");
-							return Err(Error::Serialization(ser::Error::UnexpectedData {
-								expected: vec![],
-								received: vec![],
-							}));
+							return Err(Error::PeerWithSelf);
 						}
 					}
 
@@ -157,6 +158,7 @@ impl Handshake {
 					let shake = Shake {
 						version: PROTOCOL_VERSION,
 						capabilities: capab,
+						genesis: genesis,
 						total_difficulty: total_difficulty,
 						user_agent: USER_AGENT.to_string(),
 					};
@@ -165,7 +167,7 @@ impl Handshake {
 				.and_then(|(conn, shake, peer_info)| {
 					debug!(LOGGER, "Success handshake with {}.", peer_info.addr);
 					write_msg(conn, shake, Type::Shake)
-				  // when more than one protocol version is supported, choosing should go here
+					// when more than one protocol version is supported, choosing should go here
 					.map(|conn| (conn, ProtocolV1::new(), peer_info))
 				}),
 		)
@@ -193,8 +195,6 @@ fn extract_ip(advertised: &SocketAddr, conn: &TcpStream) -> SocketAddr {
   match advertised {
     &SocketAddr::V4(v4sock) => {
       let ip = v4sock.ip();
-	  debug!(LOGGER, "extract_ip - {:?}, {:?}", ip, conn.peer_addr());
-
       if ip.is_loopback() || ip.is_unspecified() {
         if let Ok(addr) =  conn.peer_addr() {
           return SocketAddr::new(addr.ip(), advertised.port());

p2p/src/msg.rs

@@ -131,7 +131,7 @@ pub struct MsgHeader {
 	magic: [u8; 2],
 	/// Type of the message.
 	pub msg_type: Type,
-	/// Tota length of the message in bytes.
+	/// Total length of the message in bytes.
 	pub msg_len: u64,
 }
 
@@ -189,6 +189,8 @@ pub struct Hand {
 	pub capabilities: Capabilities,
 	/// randomly generated for each handshake, helps detect self
 	pub nonce: u64,
+	/// genesis block of our chain, only connect to peers on the same chain
+	pub genesis: Hash,
 	/// total difficulty accumulated by the sender, used to check whether sync
 	/// may be needed
 	pub total_difficulty: Difficulty,
@@ -211,23 +213,27 @@ impl Writeable for Hand {
 		self.total_difficulty.write(writer).unwrap();
 		self.sender_addr.write(writer).unwrap();
 		self.receiver_addr.write(writer).unwrap();
-		writer.write_bytes(&self.user_agent)
+		writer.write_bytes(&self.user_agent).unwrap();
+		self.genesis.write(writer).unwrap();
+		Ok(())
 	}
 }
 
 impl Readable for Hand {
 	fn read(reader: &mut Reader) -> Result<Hand, ser::Error> {
 		let (version, capab, nonce) = ser_multiread!(reader, read_u32, read_u32, read_u64);
+		let capabilities = try!(Capabilities::from_bits(capab).ok_or(ser::Error::CorruptedData,));
 		let total_diff = try!(Difficulty::read(reader));
 		let sender_addr = try!(SockAddr::read(reader));
 		let receiver_addr = try!(SockAddr::read(reader));
 		let ua = try!(reader.read_vec());
 		let user_agent = try!(String::from_utf8(ua).map_err(|_| ser::Error::CorruptedData));
-		let capabilities = try!(Capabilities::from_bits(capab).ok_or(ser::Error::CorruptedData,));
+		let genesis = try!(Hash::read(reader));
 		Ok(Hand {
 			version: version,
 			capabilities: capabilities,
 			nonce: nonce,
+			genesis: genesis,
 			total_difficulty: total_diff,
 			sender_addr: sender_addr,
 			receiver_addr: receiver_addr,
@@ -243,6 +249,8 @@ pub struct Shake {
 	pub version: u32,
 	/// sender capabilities
 	pub capabilities: Capabilities,
+	/// genesis block of our chain, only connect to peers on the same chain
+	pub genesis: Hash,
 	/// total difficulty accumulated by the sender, used to check whether sync
 	/// may be needed
 	pub total_difficulty: Difficulty,
@@ -259,6 +267,7 @@ impl Writeable for Shake {
 		);
 		self.total_difficulty.write(writer).unwrap();
 		writer.write_bytes(&self.user_agent).unwrap();
+		self.genesis.write(writer).unwrap();
 		Ok(())
 	}
 }
@@ -266,13 +275,15 @@ impl Writeable for Shake {
 impl Readable for Shake {
 	fn read(reader: &mut Reader) -> Result<Shake, ser::Error> {
 		let (version, capab) = ser_multiread!(reader, read_u32, read_u32);
+		let capabilities = try!(Capabilities::from_bits(capab).ok_or(ser::Error::CorruptedData,));
 		let total_diff = try!(Difficulty::read(reader));
 		let ua = try!(reader.read_vec());
 		let user_agent = try!(String::from_utf8(ua).map_err(|_| ser::Error::CorruptedData));
-		let capabilities = try!(Capabilities::from_bits(capab).ok_or(ser::Error::CorruptedData,));
+		let genesis = try!(Hash::read(reader));
 		Ok(Shake {
 			version: version,
 			capabilities: capabilities,
+			genesis: genesis,
 			total_difficulty: total_diff,
 			user_agent: user_agent,
 		})

p2p/src/server.rs

@@ -77,12 +77,17 @@ unsafe impl Send for Server {}
 // TODO TLS
 impl Server {
 	/// Creates a new idle p2p server with no peers
-	pub fn new(capab: Capabilities, config: P2PConfig, adapter: Arc<NetAdapter>) -> Server {
+	pub fn new(
+		capab: Capabilities,
+		config: P2PConfig,
+		adapter: Arc<NetAdapter>,
+		genesis: Hash,
+	) -> Server {
 		Server {
 			config: config,
 			capabilities: capab,
 			peers: Arc::new(RwLock::new(HashMap::new())),
-			handshake: Arc::new(Handshake::new()),
+			handshake: Arc::new(Handshake::new(genesis)),
 			adapter: adapter,
 			stop: RefCell::new(None),
 		}
@@ -180,8 +185,6 @@ impl Server {
 		let capab = self.capabilities.clone();
 		let self_addr = SocketAddr::new(self.config.host, self.config.port);
 
-		debug!(LOGGER, "{} connecting to {}", self_addr, addr);
-
 		let socket = TcpStream::connect(&addr, &h).map_err(|e| Error::Connection(e));
 		let h2 = h.clone();
 		let request = socket

p2p/src/types.rs

@@ -45,6 +45,15 @@ pub enum Error {
 	Connection(io::Error),
 	ConnectionClose,
 	Timeout,
+	PeerWithSelf,
+	ProtocolMismatch {
+		us: u32,
+		peer: u32,
+	},
+	GenesisMismatch {
+		us: Hash,
+		peer: Hash,
+	},
 }
 
 impl From<ser::Error> for Error {

p2p/tests/peer_handshake.rs

@@ -26,6 +26,7 @@ use tokio_core::net::TcpStream;
 use tokio_core::reactor::{self, Core};
 
 use core::core::target::Difficulty;
+use core::core::hash::Hash;
 use p2p::Peer;
 
 // Starts a server and connects a client peer to it to check handshake,
@@ -36,7 +37,12 @@ fn peer_handshake() {
 	let handle = evtlp.handle();
 	let p2p_conf = p2p::P2PConfig::default();
 	let net_adapter = Arc::new(p2p::DummyAdapter {});
-	let server = p2p::Server::new(p2p::UNKNOWN, p2p_conf, net_adapter.clone());
+	let server = p2p::Server::new(
+		p2p::UNKNOWN,
+		p2p_conf,
+		net_adapter.clone(),
+		Hash::from_vec(vec![]),
+	);
 	let run_server = server.start(handle.clone());
 	let my_addr = "127.0.0.1:5000".parse().unwrap();
 
@@ -59,7 +65,7 @@ fn peer_handshake() {
 							p2p::UNKNOWN,
 							Difficulty::one(),
 							my_addr,
-							Arc::new(p2p::handshake::Handshake::new()),
+							Arc::new(p2p::handshake::Handshake::new(Hash::from_vec(vec![]))),
 							net_adapter.clone(),
 						)
 					})

pow/src/lib.rs

@@ -95,8 +95,9 @@ pub fn pow20<T: MiningWorker>(
 
 /// Mines a genesis block, using the config specified miner if specified.
 /// Otherwise, uses the internal miner
-pub fn mine_genesis_block(miner_config: Option<types::MinerConfig>) -> Option<core::core::Block> {
-	info!(util::LOGGER, "Genesis block not found, initializing...");
+pub fn mine_genesis_block(
+	miner_config: Option<types::MinerConfig>,
+) -> Result<core::core::Block, Error> {
 	let mut gen = genesis::genesis_dev();
 	let diff = gen.header.difficulty.clone();
 
@@ -114,7 +115,7 @@ pub fn mine_genesis_block(miner_config: Option<types::MinerConfig>) -> Option<co
 		None => Box::new(cuckoo::Miner::new(consensus::EASINESS, sz, proof_size)),
 	};
 	pow_size(&mut *miner, &mut gen.header, diff, sz as u32).unwrap();
-	Some(gen)
+	Ok(gen)
 }
 
 /// Runs a proof of work computation over the provided block using the provided