light: integrate with sync + serve_light CLI

Cargo.lock

@@ -18,6 +18,7 @@ dependencies = [
  "ethcore-ipc-hypervisor 1.2.0",
  "ethcore-ipc-nano 1.4.0",
  "ethcore-ipc-tests 0.1.0",
+ "ethcore-light 1.5.0",
  "ethcore-logger 1.5.0",
  "ethcore-rpc 1.5.0",
  "ethcore-signer 1.5.0",

Cargo.toml

@@ -47,6 +47,7 @@ rlp = { path = "util/rlp" }
 ethcore-stratum = { path = "stratum" }
 ethcore-dapps = { path = "dapps", optional = true }
 clippy = { version = "0.0.103", optional = true}
+ethcore-light = { path = "ethcore/light" }
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.2"

ethcore/light/build.rs

@@ -20,6 +20,7 @@ extern crate ethcore_ipc_codegen;
 #[cfg(feature = "ipc")]
 fn main() {
 	ethcore_ipc_codegen::derive_binary("src/types/mod.rs.in").unwrap();
+	ethcore_ipc_codegen::derive_ipc_cond("src/provider.rs", true).unwrap();
 }
 
 #[cfg(not(feature = "ipc"))]

ethcore/light/src/lib.rs

@@ -33,8 +33,21 @@
 
 pub mod client;
 pub mod net;
+
+#[cfg(not(feature = "ipc"))]
 pub mod provider;
 
+#[cfg(feature = "ipc")]
+pub mod provider {
+    #![allow(dead_code, unused_assignments, unused_variables, missing_docs)] // codegen issues
+	include!(concat!(env!("OUT_DIR"), "/provider.rs"));
+}
+
+#[cfg(feature = "ipc")]
+pub mod remote {
+    pub use provider::LightProviderClient;
+}
+
 mod types;
 
 pub use self::provider::Provider;

ethcore/light/src/net/buffer_flow.rs

@@ -22,6 +22,9 @@
 //!
 //! This module provides an interface for configuration of buffer
 //! flow costs and recharge rates.
+//!
+//! Current default costs are picked completely arbitrarily, not based 
+//! on any empirical timings or mathematical models.
 
 use request;
 use super::packet;
@@ -273,6 +276,16 @@ impl FlowParams {
 	}
 }
 
+impl Default for FlowParams {
+	fn default() -> Self {
+		FlowParams {
+			limit: 50_000_000.into(),
+			costs: CostTable::default(),
+			recharge: 100_000.into(),
+		}
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

ethcore/light/src/net/mod.rs

@@ -30,13 +30,14 @@ use util::{Bytes, Mutex, RwLock, U256};
 use time::SteadyTime;
 
 use std::collections::HashMap;
+use std::sync::Arc;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
 use provider::Provider;
 use request::{self, Request};
 
 use self::buffer_flow::{Buffer, FlowParams};
-use self::context::{IoContext, EventContext, Ctx};
+use self::context::Ctx;
 use self::error::{Error, Punishment};
 
 mod buffer_flow;
@@ -47,16 +48,20 @@ mod status;
 #[cfg(test)]
 mod tests;
 
-pub use self::status::{Status, Capabilities, Announcement, NetworkId};
+pub use self::context::{EventContext, IoContext};
+pub use self::status::{Status, Capabilities, Announcement};
 
 const TIMEOUT: TimerToken = 0;
 const TIMEOUT_INTERVAL_MS: u64 = 1000;
 
-// LPV1
-const PROTOCOL_VERSION: u32 = 1;
+// Supported protocol versions.
+pub const PROTOCOL_VERSIONS: &'static [u8] = &[1];
 
-// TODO [rob] make configurable.
-const PROTOCOL_ID: [u8; 3] = *b"les";
+// Max protocol version.
+pub const MAX_PROTOCOL_VERSION: u8 = 1;
+
+// Packet count for LES.
+pub const PACKET_COUNT: u8 = 15;
 
 // packet ID definitions.
 mod packet {
@@ -173,6 +178,8 @@ pub trait Handler: Send + Sync {
 	/// Called when a peer responds with header proofs. Each proof is a block header coupled 
 	/// with a series of trie nodes is ascending order by distance from the root.
 	fn on_header_proofs(&self, _ctx: &EventContext, _req_id: ReqId, _proofs: &[(Bytes, Vec<Bytes>)]) { }
+	/// Called on abort.
+	fn on_abort(&self) { }
 }
 
 // a request, the peer who it was made to, and the time it was made.
@@ -185,7 +192,7 @@ struct Requested {
 /// Protocol parameters.
 pub struct Params {
 	/// Network id.
-	pub network_id: NetworkId,
+	pub network_id: u64,
 	/// Buffer flow parameters.
 	pub flow_params: FlowParams,
 	/// Initial capabilities.
@@ -203,9 +210,9 @@ pub struct Params {
 //   Locks must be acquired in the order declared, and when holding a read lock 
 //   on the peers, only one peer may be held at a time.
 pub struct LightProtocol {
-	provider: Box<Provider>,
+	provider: Arc<Provider>,
 	genesis_hash: H256,
-	network_id: NetworkId,
+	network_id: u64,
 	pending_peers: RwLock<HashMap<PeerId, PendingPeer>>,
 	peers: RwLock<HashMap<PeerId, Mutex<Peer>>>,
 	pending_requests: RwLock<HashMap<usize, Requested>>,
@@ -217,7 +224,7 @@ pub struct LightProtocol {
 
 impl LightProtocol {
 	/// Create a new instance of the protocol manager.
-	pub fn new(provider: Box<Provider>, params: Params) -> Self {
+	pub fn new(provider: Arc<Provider>, params: Params) -> Self {
 		let genesis_hash = provider.chain_info().genesis_hash;
 		LightProtocol {
 			provider: provider,
@@ -323,6 +330,23 @@ impl LightProtocol {
 		self.handlers.push(handler);
 	}
 
+	/// Signal to handlers that network activity is being aborted
+	/// and clear peer data.
+	pub fn abort(&self) {
+		for handler in &self.handlers {
+			handler.on_abort();
+		}
+
+		// acquire in order and hold.
+		let mut pending_peers = self.pending_peers.write();
+		let mut peers = self.peers.write();
+		let mut pending_requests = self.pending_requests.write();
+
+		pending_peers.clear();
+		peers.clear();
+		pending_requests.clear();
+	}
+
 	// Does the common pre-verification of responses before the response itself 
 	// is actually decoded:
 	//   - check whether peer exists
@@ -460,7 +484,7 @@ impl LightProtocol {
 			head_hash: chain_info.best_block_hash,
 			head_num: chain_info.best_block_number,
 			genesis_hash: chain_info.genesis_hash,
-			protocol_version: PROTOCOL_VERSION,
+			protocol_version: MAX_PROTOCOL_VERSION as u32,
 			network_id: self.network_id,
 			last_head: None,
 		};

ethcore/light/src/net/status.rs

@@ -82,26 +82,6 @@ impl Key {
 	}
 }
 
-/// Network ID structure.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[repr(u32)]
-pub enum NetworkId {
-	/// ID for the mainnet
-	Mainnet = 1,
-	/// ID for the testnet
-	Testnet = 0,
-}
-
-impl NetworkId {
-	fn from_raw(raw: u32) -> Option<Self> {
-		match raw {
-			0 => Some(NetworkId::Testnet),
-			1 => Some(NetworkId::Mainnet),
-			_ => None,
-		}
-	}
-}
-
 // helper for decoding key-value pairs in the handshake or an announcement.
 struct Parser<'a> {
 	pos: usize,
@@ -164,7 +144,7 @@ pub struct Status {
 	/// Protocol version.
 	pub protocol_version: u32,
 	/// Network id of this peer.
-	pub network_id: NetworkId,
+	pub network_id: u64,
 	/// Total difficulty of the head of the chain.
 	pub head_td: U256,
 	/// Hash of the best block.
@@ -225,8 +205,7 @@ pub fn parse_handshake(rlp: UntrustedRlp) -> Result<(Status, Capabilities, FlowP
 
 	let status = Status {
 		protocol_version: try!(parser.expect(Key::ProtocolVersion)),
-		network_id: try!(parser.expect(Key::NetworkId)
-			.and_then(|id: u32| NetworkId::from_raw(id).ok_or(DecoderError::Custom("Invalid network ID")))),
+		network_id: try!(parser.expect(Key::NetworkId)),
 		head_td: try!(parser.expect(Key::HeadTD)),
 		head_hash: try!(parser.expect(Key::HeadHash)),
 		head_num: try!(parser.expect(Key::HeadNum)),
@@ -254,7 +233,7 @@ pub fn parse_handshake(rlp: UntrustedRlp) -> Result<(Status, Capabilities, FlowP
 pub fn write_handshake(status: &Status, capabilities: &Capabilities, flow_params: &FlowParams) -> Vec<u8> {
 	let mut pairs = Vec::new();
 	pairs.push(encode_pair(Key::ProtocolVersion, &status.protocol_version));
-	pairs.push(encode_pair(Key::NetworkId, &(status.network_id as u32)));
+	pairs.push(encode_pair(Key::NetworkId, &(status.network_id as u64)));
 	pairs.push(encode_pair(Key::HeadTD, &status.head_td));
 	pairs.push(encode_pair(Key::HeadHash, &status.head_hash));
 	pairs.push(encode_pair(Key::HeadNum, &status.head_num));
@@ -385,7 +364,7 @@ mod tests {
 	fn full_handshake() {
 		let status = Status {
 			protocol_version: 1,
-			network_id: NetworkId::Mainnet,
+			network_id: 1,
 			head_td: U256::default(),
 			head_hash: H256::default(),
 			head_num: 10,
@@ -420,7 +399,7 @@ mod tests {
 	fn partial_handshake() {
 		let status = Status {
 			protocol_version: 1,
-			network_id: NetworkId::Mainnet,
+			network_id: 1,
 			head_td: U256::default(),
 			head_hash: H256::default(),
 			head_num: 10,
@@ -455,7 +434,7 @@ mod tests {
 	fn skip_unknown_keys() {
 		let status = Status {
 			protocol_version: 1,
-			network_id: NetworkId::Mainnet,
+			network_id: 1,
 			head_td: U256::default(),
 			head_hash: H256::default(),
 			head_num: 10,

ethcore/light/src/net/tests/mod.rs

@@ -25,7 +25,7 @@ use network::PeerId;
 
 use net::buffer_flow::FlowParams;
 use net::context::IoContext;
-use net::status::{Capabilities, Status, NetworkId, write_handshake};
+use net::status::{Capabilities, Status, write_handshake};
 use net::{encode_request, LightProtocol, Params, packet};
 use provider::Provider;
 use request::{self, Request, Headers};
@@ -174,8 +174,8 @@ fn setup(flow_params: FlowParams, capabilities: Capabilities) -> (Arc<TestProvid
 		client: TestBlockChainClient::new(),
 	});
 
-	let proto = LightProtocol::new(Box::new(TestProvider(provider.clone())), Params {
-		network_id: NetworkId::Testnet,
+	let proto = LightProtocol::new(Arc::new(TestProvider(provider.clone())), Params {
+		network_id: 2,
 		flow_params: flow_params,
 		capabilities: capabilities,
 	});
@@ -185,8 +185,8 @@ fn setup(flow_params: FlowParams, capabilities: Capabilities) -> (Arc<TestProvid
 
 fn status(chain_info: BlockChainInfo) -> Status {
 	Status {
-		protocol_version: ::net::PROTOCOL_VERSION,
-		network_id: NetworkId::Testnet,
+		protocol_version: 1,
+		network_id: 2,
 		head_td: chain_info.total_difficulty,
 		head_hash: chain_info.best_block_hash,
 		head_num: chain_info.best_block_number,

ethcore/light/src/provider.rs

@@ -33,6 +33,7 @@ use request;
 /// or empty vector where appropriate.
 ///
 /// [1]: https://github.com/ethcore/parity/wiki/Light-Ethereum-Subprotocol-(LES)
+#[cfg_attr(feature = "ipc", ipc(client_ident="LightProviderClient"))]
 pub trait Provider: Send + Sync {
 	/// Provide current blockchain info.
 	fn chain_info(&self) -> BlockChainInfo;

parity/cli/config.full.toml

@@ -32,6 +32,7 @@ warp = true
 allow_ips = "all"
 snapshot_peers = 0
 max_pending_peers = 64
+serve_light = true
 
 reserved_only = false
 reserved_peers = "./path_to_file"

parity/cli/mod.rs

@@ -135,6 +135,8 @@ usage! {
 		flag_reserved_only: bool = false,
 			or |c: &Config| otry!(c.network).reserved_only.clone(),
 		flag_no_ancient_blocks: bool = false, or |_| None,
+		flag_serve_light: bool = false,
+			or |c: &Config| otry!(c.network).serve_light.clone(),
 
 		// -- API and Console Options
 		// RPC
@@ -334,6 +336,7 @@ struct Network {
 	node_key: Option<String>,
 	reserved_peers: Option<String>,
 	reserved_only: Option<bool>,
+	serve_light: Option<bool>,
 }
 
 #[derive(Default, Debug, PartialEq, RustcDecodable)]
@@ -543,6 +546,7 @@ mod tests {
 			flag_reserved_peers: Some("./path_to_file".into()),
 			flag_reserved_only: false,
 			flag_no_ancient_blocks: false,
+			flag_serve_light: true,
 
 			// -- API and Console Options
 			// RPC
@@ -713,6 +717,7 @@ mod tests {
 				node_key: None,
 				reserved_peers: Some("./path/to/reserved_peers".into()),
 				reserved_only: Some(true),
+				serve_light: None,
 			}),
 			rpc: Some(Rpc {
 				disable: Some(true),

parity/cli/usage.txt

@@ -97,6 +97,7 @@ Networking Options:
   --max-pending-peers NUM  Allow up to NUM pending connections. (default: {flag_max_pending_peers})
   --no-ancient-blocks      Disable downloading old blocks after snapshot restoration
                            or warp sync. (default: {flag_no_ancient_blocks})
+  --serve-light            Experimental: Serve light client peers. (default: {flag_serve_light})
 
 API and Console Options:
   --no-jsonrpc             Disable the JSON-RPC API server. (default: {flag_no_jsonrpc})

parity/configuration.rs

@@ -275,6 +275,7 @@ impl Configuration {
 				no_periodic_snapshot: self.args.flag_no_periodic_snapshot,
 				check_seal: !self.args.flag_no_seal_check,
 				download_old_blocks: !self.args.flag_no_ancient_blocks,
+				serve_light: self.args.flag_serve_light,
 			};
 			Cmd::Run(run_cmd)
 		};
@@ -921,6 +922,7 @@ mod tests {
 			no_periodic_snapshot: false,
 			check_seal: true,
 			download_old_blocks: true,
+			serve_light: false,
 		}));
 	}
 

parity/main.rs

@@ -43,6 +43,7 @@ extern crate serde;
 extern crate serde_json;
 extern crate rlp;
 extern crate ethcore_hash_fetch as hash_fetch;
+extern crate ethcore_light as light;
 
 extern crate ethcore_ipc_hypervisor as hypervisor;
 extern crate ethcore_rpc;

parity/modules.rs

@@ -15,16 +15,22 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 use std::sync::Arc;
+use std::path::Path;
+
 use ethcore::client::BlockChainClient;
 use hypervisor::Hypervisor;
-use ethsync::{SyncConfig, NetworkConfiguration, NetworkError};
+use ethsync::{SyncConfig, NetworkConfiguration, NetworkError, Params};
 use ethcore::snapshot::SnapshotService;
+use light::Provider;
+
 #[cfg(not(feature="ipc"))]
 use self::no_ipc_deps::*;
+
+#[cfg(not(feature="ipc"))]
+use ethcore_logger::Config as LogConfig;
+
 #[cfg(feature="ipc")]
 use self::ipc_deps::*;
-use ethcore_logger::Config as LogConfig;
-use std::path::Path;
 
 #[cfg(feature="ipc")]
 pub mod service_urls {
@@ -36,6 +42,8 @@ pub mod service_urls {
 	pub const SYNC_NOTIFY: &'static str = "parity-sync-notify.ipc";
 	pub const NETWORK_MANAGER: &'static str = "parity-manage-net.ipc";
 	pub const SYNC_CONTROL: &'static str = "parity-sync-control.ipc";
+	pub const LIGHT_PROVIDER: &'static str = "parity-light-provider.ipc";
+
 	#[cfg(feature="stratum")]
 	pub const STRATUM: &'static str = "parity-stratum.ipc";
 	#[cfg(feature="stratum")]
@@ -75,6 +83,7 @@ mod ipc_deps {
 	pub use nanoipc::{GuardedSocket, NanoSocket, generic_client, fast_client};
 	pub use ipc::IpcSocket;
 	pub use ipc::binary::serialize;
+	pub use light::remote::LightProviderClient;
 }
 
 #[cfg(feature="ipc")]
@@ -124,6 +133,7 @@ pub fn sync
 		net_cfg: NetworkConfiguration,
 		_client: Arc<BlockChainClient>,
 		_snapshot_service: Arc<SnapshotService>,
+		_provider: Arc<Provider>,		
 		log_settings: &LogConfig,
 	)
 	-> Result<SyncModules, NetworkError>
@@ -141,7 +151,9 @@ pub fn sync
 		&service_urls::with_base(&hypervisor.io_path, service_urls::SYNC_NOTIFY)).unwrap();
 	let manage_client = generic_client::<NetworkManagerClient<_>>(
 		&service_urls::with_base(&hypervisor.io_path, service_urls::NETWORK_MANAGER)).unwrap();
-
+	let provider_client = generic_client::<LightProviderClient<_>>(
+		&service_urls::with_base(&hypervisor.io_path, service_urls::LIGHT_PROVIDER)).unwrap();
+		
 	*hypervisor_ref = Some(hypervisor);
 	Ok((sync_client, manage_client, notify_client))
 }
@@ -154,10 +166,18 @@ pub fn sync
 		net_cfg: NetworkConfiguration,
 		client: Arc<BlockChainClient>,
 		snapshot_service: Arc<SnapshotService>,
+		provider: Arc<Provider>,		
 		_log_settings: &LogConfig,
 	)
 	-> Result<SyncModules, NetworkError>
 {
-	let eth_sync = try!(EthSync::new(sync_cfg, client, snapshot_service, net_cfg));
+	let eth_sync = try!(EthSync::new(Params {
+		config: sync_cfg, 
+		chain: client,
+		provider: provider,
+		snapshot_service: snapshot_service, 
+		network_config: net_cfg,
+	}));
+
 	Ok((eth_sync.clone() as Arc<SyncProvider>, eth_sync.clone() as Arc<ManageNetwork>, eth_sync.clone() as Arc<ChainNotify>))
 }

parity/run.rs

@@ -92,6 +92,7 @@ pub struct RunCmd {
 	pub no_periodic_snapshot: bool,
 	pub check_seal: bool,
 	pub download_old_blocks: bool,
+	pub serve_light: bool,
 }
 
 pub fn open_ui(dapps_conf: &dapps::Configuration, signer_conf: &signer::Configuration) -> Result<(), String> {
@@ -185,6 +186,11 @@ pub fn execute(cmd: RunCmd, logger: Arc<RotatingLogger>) -> Result<(), String> {
 	);
 	info!("Operating mode: {}", Colour::White.bold().paint(format!("{}", mode)));
 
+	if cmd.serve_light {
+		info!("Configured to serve light client peers. Please note this feature is {}.",
+			Colour::White.bold().paint("experimental".to_string()));
+	}
+
 	// display warning about using experimental journaldb alorithm
 	if !algorithm.is_stable() {
 		warn!("Your chosen strategy is {}! You can re-run with --pruning to change.", Colour::Red.bold().paint("unstable"));
@@ -204,6 +210,7 @@ pub fn execute(cmd: RunCmd, logger: Arc<RotatingLogger>) -> Result<(), String> {
 	sync_config.fork_block = spec.fork_block();
 	sync_config.warp_sync = cmd.warp_sync;
 	sync_config.download_old_blocks = cmd.download_old_blocks;
+	sync_config.serve_light = cmd.serve_light;
 
 	// prepare account provider
 	let account_provider = Arc::new(try!(prepare_account_provider(&cmd.dirs, cmd.acc_conf)));
@@ -268,7 +275,13 @@ pub fn execute(cmd: RunCmd, logger: Arc<RotatingLogger>) -> Result<(), String> {
 
 	// create sync object
 	let (sync_provider, manage_network, chain_notify) = try!(modules::sync(
-		&mut hypervisor, sync_config, net_conf.into(), client.clone(), snapshot_service.clone(), &cmd.logger_config,
+		&mut hypervisor, 
+		sync_config, 
+		net_conf.into(), 
+		client.clone(), 
+		snapshot_service.clone(), 
+		client.clone(), 
+		&cmd.logger_config,
 	).map_err(|e| format!("Sync error: {}", e)));
 
 	service.add_notify(chain_notify.clone());

parity/sync.rs

@@ -22,6 +22,7 @@ use hypervisor::{SYNC_MODULE_ID, HYPERVISOR_IPC_URL, ControlService};
 use ethcore::client::ChainNotify;
 use ethcore::client::remote::RemoteClient;
 use ethcore::snapshot::remote::RemoteSnapshotService;
+use light::remote::LightProviderClient;
 use ethsync::{SyncProvider, EthSync, ManageNetwork, ServiceConfiguration};
 use modules::service_urls;
 use boot;
@@ -48,8 +49,15 @@ pub fn main() {
 
 	let remote_client = dependency!(RemoteClient, &service_urls::with_base(&service_config.io_path, service_urls::CLIENT));
 	let remote_snapshot = dependency!(RemoteSnapshotService, &service_urls::with_base(&service_config.io_path, service_urls::SNAPSHOT));
+	let remote_provider = dependency!(LightProviderClient, &service_urls::with_base(&service_config.io_path, service_urls::LIGHT_PROVIDER));
 
-	let sync = EthSync::new(service_config.sync, remote_client.service().clone(), remote_snapshot.service().clone(), service_config.net).unwrap();
+	let sync = EthSync::new(Params {
+		config: service_config.sync, 
+		chain: remote_client.service().clone(), 
+		snapshot_service: remote_snapshot.service().clone(), 
+		provider: remote_provider.service().clone(),
+		network_config: service_config.net
+	}).unwrap();
 
 	let _ = boot::main_thread();
 	let service_stop = Arc::new(AtomicBool::new(false));

sync/build.rs

@@ -16,6 +16,10 @@
 
 extern crate ethcore_ipc_codegen;
 
+#[cfg(feature = "ipc")]
 fn main() {
-	ethcore_ipc_codegen::derive_ipc_cond("src/api.rs", cfg!(feature="ipc")).unwrap();
+	ethcore_ipc_codegen::derive_ipc_cond("src/api.rs", true).unwrap();
 }
+
+#[cfg(not(feature = "ipc"))]
+fn main() {}

sync/src/api.rs

@@ -33,6 +33,7 @@ use ipc::{BinaryConvertable, BinaryConvertError, IpcConfig};
 use std::str::FromStr;
 use parking_lot::RwLock;
 use chain::{ETH_PACKET_COUNT, SNAPSHOT_SYNC_PACKET_COUNT};
+use light::net::{LightProtocol, Params as LightParams, Capabilities, Handler as LightHandler, EventContext};
 
 pub const WARP_SYNC_PROTOCOL_ID: ProtocolId = *b"par";
 
@@ -47,10 +48,14 @@ pub struct SyncConfig {
 	pub network_id: u64,
 	/// Main "eth" subprotocol name.
 	pub subprotocol_name: [u8; 3],
+	/// Light "les" subprotocol name.
+	pub light_subprotocol_name: [u8; 3],
 	/// Fork block to check
 	pub fork_block: Option<(BlockNumber, H256)>,
 	/// Enable snapshot sync
 	pub warp_sync: bool,
+	/// Enable light client server.
+	pub serve_light: bool,
 }
 
 impl Default for SyncConfig {
@@ -60,8 +65,10 @@ impl Default for SyncConfig {
 			download_old_blocks: true,
 			network_id: 1,
 			subprotocol_name: *b"eth",
+			light_subprotocol_name: *b"les",
 			fork_block: None,
 			warp_sync: false,
+			serve_light: false,
 		}
 	}
 }
@@ -116,30 +123,74 @@ pub struct PeerInfo {
 	pub eth_difficulty: Option<U256>,
 }
 
+/// EthSync initialization parameters.
+#[cfg_attr(feature = "ipc", derive(Binary))]
+pub struct Params {
+	/// Configuration.
+	pub config: SyncConfig,
+	/// Blockchain client.
+	pub chain: Arc<BlockChainClient>,
+	/// Snapshot service.
+	pub snapshot_service: Arc<SnapshotService>,
+	/// Light data provider.
+	pub provider: Arc<::light::Provider>,
+	/// Network layer configuration.
+	pub network_config: NetworkConfiguration,
+}
+
 /// Ethereum network protocol handler
 pub struct EthSync {
 	/// Network service
 	network: NetworkService,
-	/// Protocol handler
-	handler: Arc<SyncProtocolHandler>,
+	/// Main (eth/par) protocol handler
+	sync_handler: Arc<SyncProtocolHandler>,
+	/// Light (les) protocol handler 
+	light_proto: Option<Arc<LightProtocol>>,
 	/// The main subprotocol name
 	subprotocol_name: [u8; 3],
+	/// Light subprotocol name.
+	light_subprotocol_name: [u8; 3],
 }
 
 impl EthSync {
 	/// Creates and register protocol with the network service
-	pub fn new(config: SyncConfig, chain: Arc<BlockChainClient>, snapshot_service: Arc<SnapshotService>, network_config: NetworkConfiguration) -> Result<Arc<EthSync>, NetworkError> {
-		let chain_sync = ChainSync::new(config, &*chain);
-		let service = try!(NetworkService::new(try!(network_config.clone().into_basic())));
-		let sync = Arc::new(EthSync{
+	pub fn new(params: Params) -> Result<Arc<EthSync>, NetworkError> {
+		let pruning_info = params.chain.pruning_info();		
+		let light_proto = match params.config.serve_light {
+			false => None,
+			true => Some({
+				let light_params = LightParams {
+					network_id: params.config.network_id,
+					flow_params: Default::default(),
+					capabilities: Capabilities {
+						serve_headers: true,
+						serve_chain_since: Some(pruning_info.earliest_chain),
+						serve_state_since: Some(pruning_info.earliest_state),
+						tx_relay: true,
+					},
+				};
+
+				let mut light_proto = LightProtocol::new(params.provider, light_params);
+				light_proto.add_handler(Box::new(TxRelay(params.chain.clone())));
+
+				Arc::new(light_proto)
+			})
+		};
+
+		let chain_sync = ChainSync::new(params.config, &*params.chain);
+		let service = try!(NetworkService::new(try!(params.network_config.clone().into_basic())));
+
+		let sync = Arc::new(EthSync {
 			network: service,
-			handler: Arc::new(SyncProtocolHandler {
+			sync_handler: Arc::new(SyncProtocolHandler {
 				sync: RwLock::new(chain_sync),
-				chain: chain,
-				snapshot_service: snapshot_service,
+				chain: params.chain,
+				snapshot_service: params.snapshot_service,
 				overlay: RwLock::new(HashMap::new()),
 			}),
-			subprotocol_name: config.subprotocol_name,
+			light_proto: light_proto,
+			subprotocol_name: params.config.subprotocol_name,
+			light_subprotocol_name: params.config.light_subprotocol_name,
 		});
 
 		Ok(sync)
@@ -150,14 +201,15 @@ impl EthSync {
 impl SyncProvider for EthSync {
 	/// Get sync status
 	fn status(&self) -> SyncStatus {
-		self.handler.sync.write().status()
+		self.sync_handler.sync.write().status()
 	}
 
 	/// Get sync peers
 	fn peers(&self) -> Vec<PeerInfo> {
+		// TODO: [rob] LES peers/peer info
 		self.network.with_context_eval(self.subprotocol_name, |context| {
-			let sync_io = NetSyncIo::new(context, &*self.handler.chain, &*self.handler.snapshot_service, &self.handler.overlay);
-			self.handler.sync.write().peers(&sync_io)
+			let sync_io = NetSyncIo::new(context, &*self.sync_handler.chain, &*self.sync_handler.snapshot_service, &self.sync_handler.overlay);
+			self.sync_handler.sync.write().peers(&sync_io)
 		}).unwrap_or(Vec::new())
 	}
 
@@ -166,7 +218,7 @@ impl SyncProvider for EthSync {
 	}
 
 	fn transactions_stats(&self) -> BTreeMap<H256, TransactionStats> {
-		let sync = self.handler.sync.read();
+		let sync = self.sync_handler.sync.read();
 		sync.transactions_stats()
 			.iter()
 			.map(|(hash, stats)| (*hash, stats.into()))
@@ -228,8 +280,8 @@ impl ChainNotify for EthSync {
 		_duration: u64)
 	{
 		self.network.with_context(self.subprotocol_name, |context| {
-			let mut sync_io = NetSyncIo::new(context, &*self.handler.chain, &*self.handler.snapshot_service, &self.handler.overlay);
-			self.handler.sync.write().chain_new_blocks(
+			let mut sync_io = NetSyncIo::new(context, &*self.sync_handler.chain, &*self.sync_handler.snapshot_service, &self.sync_handler.overlay);
+			self.sync_handler.sync.write().chain_new_blocks(
 				&mut sync_io,
 				&imported,
 				&invalid,
@@ -245,19 +297,36 @@ impl ChainNotify for EthSync {
 			Err(err) => warn!("Error starting network: {}", err),
 			_ => {},
 		}
-		self.network.register_protocol(self.handler.clone(), self.subprotocol_name, ETH_PACKET_COUNT, &[62u8, 63u8])
+		self.network.register_protocol(self.sync_handler.clone(), self.subprotocol_name, ETH_PACKET_COUNT, &[62u8, 63u8])
 			.unwrap_or_else(|e| warn!("Error registering ethereum protocol: {:?}", e));
 		// register the warp sync subprotocol
-		self.network.register_protocol(self.handler.clone(), WARP_SYNC_PROTOCOL_ID, SNAPSHOT_SYNC_PACKET_COUNT, &[1u8])
+		self.network.register_protocol(self.sync_handler.clone(), WARP_SYNC_PROTOCOL_ID, SNAPSHOT_SYNC_PACKET_COUNT, &[1u8])
 			.unwrap_or_else(|e| warn!("Error registering snapshot sync protocol: {:?}", e));
+		
+		// register the light protocol.
+		if let Some(light_proto) = self.light_proto.as_ref().map(|x| x.clone()) {
+			self.network.register_protocol(light_proto, self.light_subprotocol_name, ::light::net::PACKET_COUNT, ::light::net::PROTOCOL_VERSIONS)
+				.unwrap_or_else(|e| warn!("Error registering light client protocol: {:?}", e));
+		}
 	}
 
 	fn stop(&self) {
-		self.handler.snapshot_service.abort_restore();
+		self.sync_handler.snapshot_service.abort_restore();
 		self.network.stop().unwrap_or_else(|e| warn!("Error stopping network: {:?}", e));
 	}
 }
 
+/// LES event handler.
+/// Simply queues transactions from light client peers.
+struct TxRelay(Arc<BlockChainClient>);
+
+impl LightHandler for TxRelay {
+	fn on_transactions(&self, ctx: &EventContext, relay: &[::ethcore::transaction::SignedTransaction]) {
+		trace!(target: "les", "Relaying {} transactions from peer {}", relay.len(), ctx.peer());
+		self.0.queue_transactions(relay.iter().map(|tx| ::rlp::encode(tx).to_vec()).collect())
+	}
+}
+
 impl IpcConfig for ManageNetwork { }
 impl IpcConfig for SyncProvider { }
 
@@ -304,9 +373,14 @@ impl ManageNetwork for EthSync {
 
 	fn stop_network(&self) {
 		self.network.with_context(self.subprotocol_name, |context| {
-			let mut sync_io = NetSyncIo::new(context, &*self.handler.chain, &*self.handler.snapshot_service, &self.handler.overlay);
-			self.handler.sync.write().abort(&mut sync_io);
+			let mut sync_io = NetSyncIo::new(context, &*self.sync_handler.chain, &*self.sync_handler.snapshot_service, &self.sync_handler.overlay);
+			self.sync_handler.sync.write().abort(&mut sync_io);
 		});
+
+		if let Some(light_proto) = self.light_proto.as_ref() {
+			light_proto.abort();
+		}
+
 		self.stop();
 	}
 
@@ -452,4 +526,4 @@ pub struct ServiceConfiguration {
 	pub net: NetworkConfiguration,
 	/// IPC path.
 	pub io_path: String,
-}
+}

sync/src/lib.rs

@@ -67,7 +67,7 @@ mod api {
 #[cfg(not(feature = "ipc"))]
 mod api;
 
-pub use api::{EthSync, SyncProvider, ManageNetwork, SyncConfig,
+pub use api::{EthSync, Params, SyncProvider, ManageNetwork, SyncConfig,
 	ServiceConfiguration, NetworkConfiguration, PeerInfo, AllowIP, TransactionStats};
 pub use chain::{SyncStatus, SyncState};
 pub use network::{is_valid_node_url, NonReservedPeerMode, NetworkError};