Merge branch 'master' into ui-2

ethcore/light/src/net/error.rs

@@ -66,6 +66,8 @@ pub enum Error {
 	BadProtocolVersion,
 	/// Peer is overburdened.
 	Overburdened,
+	/// No handler kept the peer.
+	RejectedByHandlers,
 }
 
 impl Error {
@@ -85,6 +87,7 @@ impl Error {
 			Error::UnsupportedProtocolVersion(_) => Punishment::Disable,
 			Error::BadProtocolVersion => Punishment::Disable,
 			Error::Overburdened => Punishment::None,
+			Error::RejectedByHandlers => Punishment::Disconnect,
 		}
 	}
 }
@@ -117,6 +120,7 @@ impl fmt::Display for Error {
 			Error::UnsupportedProtocolVersion(pv) => write!(f, "Unsupported protocol version: {}", pv),
 			Error::BadProtocolVersion => write!(f, "Bad protocol version in handshake"),
 			Error::Overburdened => write!(f, "Peer overburdened"),
+			Error::RejectedByHandlers => write!(f, "No handler kept this peer"),
 		}
 	}
 }

ethcore/light/src/net/load_timer.rs

@@ -55,6 +55,7 @@ fn hardcoded_serve_time(kind: Kind) -> u64 {
 	match kind {
 		Kind::Headers => 500_000,
 		Kind::HeaderProof => 500_000,
+		Kind::TransactionIndex => 500_000,
 		Kind::Receipts => 1_000_000,
 		Kind::Body => 1_000_000,
 		Kind::Account => 1_500_000,

ethcore/light/src/net/mod.rs

@@ -31,6 +31,7 @@ use std::collections::{HashMap, HashSet};
 use std::fmt;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::ops::{BitOr, BitAnd, Not};
 
 use provider::Provider;
 use request::{Request, NetworkRequests as Requests, Response};
@@ -80,7 +81,7 @@ pub const PROTOCOL_VERSIONS: &'static [u8] = &[1];
 pub const MAX_PROTOCOL_VERSION: u8 = 1;
 
 /// Packet count for PIP.
-pub const PACKET_COUNT: u8 = 5;
+pub const PACKET_COUNT: u8 = 9;
 
 // packet ID definitions.
 mod packet {
@@ -100,6 +101,10 @@ mod packet {
 
 	// relay transactions to peers.
 	pub const SEND_TRANSACTIONS: u8 = 0x06;
+
+	// request and respond with epoch transition proof
+	pub const REQUEST_EPOCH_PROOF: u8 = 0x07;
+	pub const EPOCH_PROOF: u8 = 0x08;
 }
 
 // timeouts for different kinds of requests. all values are in milliseconds.
@@ -110,6 +115,7 @@ mod timeout {
 
 	// timeouts per request within packet.
 	pub const HEADERS: i64 = 250; // per header?
+	pub const TRANSACTION_INDEX: i64 = 100;
 	pub const BODY: i64 = 50;
 	pub const RECEIPT: i64 = 50;
 	pub const PROOF: i64 = 100; // state proof
@@ -157,6 +163,54 @@ pub struct Peer {
 	awaiting_acknowledge: Option<(SteadyTime, Arc<FlowParams>)>,
 }
 
+/// Whether or not a peer was kept by a handler
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum PeerStatus {
+	/// The peer was kept
+	Kept,
+	/// The peer was not kept
+	Unkept,
+}
+
+impl Not for PeerStatus {
+	type Output = Self;
+
+	fn not(self) -> Self {
+		use self::PeerStatus::*;
+
+		match self {
+			Kept => Unkept,
+			Unkept => Kept,
+		}
+	}
+}
+
+impl BitAnd for PeerStatus {
+	type Output = Self;
+
+	fn bitand(self, other: Self) -> Self {
+		use self::PeerStatus::*;
+
+		match (self, other) {
+			(Kept, Kept) => Kept,
+			_ => Unkept,
+		}
+	}
+}
+
+impl BitOr for PeerStatus {
+	type Output = Self;
+
+	fn bitor(self, other: Self) -> Self {
+		use self::PeerStatus::*;
+
+		match (self, other) {
+			(_, Kept) | (Kept, _) => Kept,
+			_ => Unkept,
+		}
+	}
+}
+
 /// A light protocol event handler.
 ///
 /// Each handler function takes a context which describes the relevant peer
@@ -168,7 +222,12 @@ pub struct Peer {
 /// that relevant data will be stored by interested handlers.
 pub trait Handler: Send + Sync {
 	/// Called when a peer connects.
-	fn on_connect(&self, _ctx: &EventContext, _status: &Status, _capabilities: &Capabilities) { }
+	fn on_connect(
+		&self,
+		_ctx: &EventContext,
+		_status: &Status,
+		_capabilities: &Capabilities
+	) -> PeerStatus { PeerStatus::Kept }
 	/// Called when a peer disconnects, with a list of unfulfilled request IDs as
 	/// of yet.
 	fn on_disconnect(&self, _ctx: &EventContext, _unfulfilled: &[ReqId]) { }
@@ -523,6 +582,12 @@ impl LightProtocol {
 
 			packet::SEND_TRANSACTIONS => self.relay_transactions(peer, io, rlp),
 
+			packet::REQUEST_EPOCH_PROOF | packet::EPOCH_PROOF => {
+				// ignore these for now, but leave them specified.
+				debug!(target: "pip", "Ignoring request/response for epoch proof");
+				Ok(())
+			}
+
 			other => {
 				Err(Error::UnrecognizedPacket(other))
 			}
@@ -766,15 +831,23 @@ impl LightProtocol {
 			awaiting_acknowledge: None,
 		}));
 
-		for handler in &self.handlers {
+		let any_kept = self.handlers.iter().map(
-			handler.on_connect(&Ctx {
+			|handler| handler.on_connect(
-				peer: *peer,
+				&Ctx {
-				io: io,
+					peer: *peer,
-				proto: self,
+					io: io,
-			}, &status, &capabilities)
+					proto: self,
-		}
+				},
+				&status,
+				&capabilities
+			)
+		).fold(PeerStatus::Kept, PeerStatus::bitor);
 
-		Ok(())
+		if any_kept == PeerStatus::Unkept {
+			Err(Error::RejectedByHandlers)
+		} else {
+			Ok(())
+		}
 	}
 
 	// Handle an announcement.
@@ -867,6 +940,7 @@ impl LightProtocol {
 			match complete_req {
 				CompleteRequest::Headers(req) => self.provider.block_headers(req).map(Response::Headers),
 				CompleteRequest::HeaderProof(req) => self.provider.header_proof(req).map(Response::HeaderProof),
+				CompleteRequest::TransactionIndex(_) => None, // don't answer these yet, but leave them in protocol.
 				CompleteRequest::Body(req) => self.provider.block_body(req).map(Response::Body),
 				CompleteRequest::Receipts(req) => self.provider.block_receipts(req).map(Response::Receipts),
 				CompleteRequest::Account(req) => self.provider.account_proof(req).map(Response::Account),

ethcore/light/src/net/request_credits.rs

@@ -83,6 +83,7 @@ impl Credits {
 pub struct CostTable {
 	base: U256, // cost per packet.
 	headers: U256, // cost per header
+	transaction_index: U256,
 	body: U256,
 	receipts: U256,
 	account: U256,
@@ -98,6 +99,7 @@ impl Default for CostTable {
 		CostTable {
 			base: 100000.into(),
 			headers: 10000.into(),
+			transaction_index: 10000.into(),
 			body: 15000.into(),
 			receipts: 5000.into(),
 			account: 25000.into(),
@@ -119,8 +121,9 @@ impl Encodable for CostTable {
 			s.append(cost);
 		}
 
-		s.begin_list(9).append(&self.base);
+		s.begin_list(10).append(&self.base);
 		append_cost(s, &self.headers, request::Kind::Headers);
+		append_cost(s, &self.transaction_index, request::Kind::TransactionIndex);
 		append_cost(s, &self.body, request::Kind::Body);
 		append_cost(s, &self.receipts, request::Kind::Receipts);
 		append_cost(s, &self.account, request::Kind::Account);
@@ -136,6 +139,7 @@ impl Decodable for CostTable {
 		let base = rlp.val_at(0)?;
 
 		let mut headers = None;
+		let mut transaction_index = None;
 		let mut body = None;
 		let mut receipts = None;
 		let mut account = None;
@@ -148,6 +152,7 @@ impl Decodable for CostTable {
 			let cost = cost_list.val_at(1)?;
 			match cost_list.val_at(0)? {
 				request::Kind::Headers => headers = Some(cost),
+				request::Kind::TransactionIndex => transaction_index = Some(cost),
 				request::Kind::Body => body = Some(cost),
 				request::Kind::Receipts => receipts = Some(cost),
 				request::Kind::Account => account = Some(cost),
@@ -163,6 +168,7 @@ impl Decodable for CostTable {
 		Ok(CostTable {
 			base: base,
 			headers: unwrap_cost(headers)?,
+			transaction_index: unwrap_cost(transaction_index)?,
 			body: unwrap_cost(body)?,
 			receipts: unwrap_cost(receipts)?,
 			account: unwrap_cost(account)?,
@@ -224,6 +230,7 @@ impl FlowParams {
 		let costs = CostTable {
 			base: 0.into(),
 			headers: cost_for_kind(Kind::Headers),
+			transaction_index: cost_for_kind(Kind::TransactionIndex),
 			body: cost_for_kind(Kind::Body),
 			receipts: cost_for_kind(Kind::Receipts),
 			account: cost_for_kind(Kind::Account),
@@ -249,6 +256,7 @@ impl FlowParams {
 			costs: CostTable {
 				base: free_cost.clone(),
 				headers: free_cost.clone(),
+				transaction_index: free_cost.clone(),
 				body: free_cost.clone(),
 				receipts: free_cost.clone(),
 				account: free_cost.clone(),
@@ -278,6 +286,7 @@ impl FlowParams {
 		match *request {
 			Request::Headers(ref req) => self.costs.headers * req.max.into(),
 			Request::HeaderProof(_) => self.costs.header_proof,
+			Request::TransactionIndex(_) => self.costs.transaction_index,
 			Request::Body(_) => self.costs.body,
 			Request::Receipts(_) => self.costs.receipts,
 			Request::Account(_) => self.costs.account,

ethcore/light/src/net/request_set.rs

@@ -132,6 +132,7 @@ fn compute_timeout(reqs: &Requests) -> Duration {
 		tm + match *req {
 			Request::Headers(_) => timeout::HEADERS,
 			Request::HeaderProof(_) => timeout::HEADER_PROOF,
+			Request::TransactionIndex(_) => timeout::TRANSACTION_INDEX,
 			Request::Receipts(_) => timeout::RECEIPT,
 			Request::Body(_) => timeout::BODY,
 			Request::Account(_) => timeout::PROOF,

ethcore/light/src/on_demand/mod.rs

@@ -29,7 +29,10 @@ use futures::sync::oneshot::{self, Sender, Receiver, Canceled};
 use network::PeerId;
 use util::{RwLock, Mutex};
 
-use net::{self, Handler, Status, Capabilities, Announcement, EventContext, BasicContext, ReqId};
+use net::{
+	self, Handler, PeerStatus, Status, Capabilities,
+	Announcement, EventContext, BasicContext, ReqId,
+};
 use cache::Cache;
 use request::{self as basic_request, Request as NetworkRequest};
 use self::request::CheckedRequest;
@@ -402,9 +405,18 @@ impl OnDemand {
 }
 
 impl Handler for OnDemand {
-	fn on_connect(&self, ctx: &EventContext, status: &Status, capabilities: &Capabilities) {
+	fn on_connect(
-		self.peers.write().insert(ctx.peer(), Peer { status: status.clone(), capabilities: capabilities.clone() });
+		&self,
+		ctx: &EventContext,
+		status: &Status,
+		capabilities: &Capabilities
+	) -> PeerStatus {
+		self.peers.write().insert(
+			ctx.peer(),
+			Peer { status: status.clone(), capabilities: capabilities.clone() }
+		);
 		self.attempt_dispatch(ctx.as_basic());
+		PeerStatus::Kept
 	}
 
 	fn on_disconnect(&self, ctx: &EventContext, unfulfilled: &[ReqId]) {

ethcore/light/src/types/request/mod.rs

@@ -32,6 +32,11 @@ pub use self::header_proof::{
 	Incomplete as IncompleteHeaderProofRequest,
 	Response as HeaderProofResponse
 };
+pub use self::transaction_index::{
+	Complete as CompleteTransactionIndexRequest,
+	Incomplete as IncompleteTransactionIndexRequest,
+	Response as TransactionIndexResponse
+};
 pub use self::block_body::{
 	Complete as CompleteBodyRequest,
 	Incomplete as IncompleteBodyRequest,
@@ -242,7 +247,8 @@ pub enum Request {
 	Headers(IncompleteHeadersRequest),
 	/// A request for a header proof (from a CHT)
 	HeaderProof(IncompleteHeaderProofRequest),
-	// TransactionIndex,
+	/// A request for a transaction index by hash.
+	TransactionIndex(IncompleteTransactionIndexRequest),
 	/// A request for a block's receipts.
 	Receipts(IncompleteReceiptsRequest),
 	/// A request for a block body.
@@ -264,7 +270,8 @@ pub enum CompleteRequest {
 	Headers(CompleteHeadersRequest),
 	/// A request for a header proof (from a CHT)
 	HeaderProof(CompleteHeaderProofRequest),
-	// TransactionIndex,
+	/// A request for a transaction index by hash.
+	TransactionIndex(CompleteTransactionIndexRequest),
 	/// A request for a block's receipts.
 	Receipts(CompleteReceiptsRequest),
 	/// A request for a block body.
@@ -285,6 +292,7 @@ impl CompleteRequest {
 		match *self {
 			CompleteRequest::Headers(_) => Kind::Headers,
 			CompleteRequest::HeaderProof(_) => Kind::HeaderProof,
+			CompleteRequest::TransactionIndex(_) => Kind::TransactionIndex,
 			CompleteRequest::Receipts(_) => Kind::Receipts,
 			CompleteRequest::Body(_) => Kind::Body,
 			CompleteRequest::Account(_) => Kind::Account,
@@ -301,6 +309,7 @@ impl Request {
 		match *self {
 			Request::Headers(_) => Kind::Headers,
 			Request::HeaderProof(_) => Kind::HeaderProof,
+			Request::TransactionIndex(_) => Kind::TransactionIndex,
 			Request::Receipts(_) => Kind::Receipts,
 			Request::Body(_) => Kind::Body,
 			Request::Account(_) => Kind::Account,
@@ -316,6 +325,7 @@ impl Decodable for Request {
 		match rlp.val_at::<Kind>(0)? {
 			Kind::Headers => Ok(Request::Headers(rlp.val_at(1)?)),
 			Kind::HeaderProof => Ok(Request::HeaderProof(rlp.val_at(1)?)),
+			Kind::TransactionIndex => Ok(Request::TransactionIndex(rlp.val_at(1)?)),
 			Kind::Receipts => Ok(Request::Receipts(rlp.val_at(1)?)),
 			Kind::Body => Ok(Request::Body(rlp.val_at(1)?)),
 			Kind::Account => Ok(Request::Account(rlp.val_at(1)?)),
@@ -336,6 +346,7 @@ impl Encodable for Request {
 		match *self {
 			Request::Headers(ref req) => s.append(req),
 			Request::HeaderProof(ref req) => s.append(req),
+			Request::TransactionIndex(ref req) => s.append(req),
 			Request::Receipts(ref req) => s.append(req),
 			Request::Body(ref req) => s.append(req),
 			Request::Account(ref req) => s.append(req),
@@ -356,6 +367,7 @@ impl IncompleteRequest for Request {
 		match *self {
 			Request::Headers(ref req) => req.check_outputs(f),
 			Request::HeaderProof(ref req) => req.check_outputs(f),
+			Request::TransactionIndex(ref req) => req.check_outputs(f),
 			Request::Receipts(ref req) => req.check_outputs(f),
 			Request::Body(ref req) => req.check_outputs(f),
 			Request::Account(ref req) => req.check_outputs(f),
@@ -369,6 +381,7 @@ impl IncompleteRequest for Request {
 		match *self {
 			Request::Headers(ref req) => req.note_outputs(f),
 			Request::HeaderProof(ref req) => req.note_outputs(f),
+			Request::TransactionIndex(ref req) => req.note_outputs(f),
 			Request::Receipts(ref req) => req.note_outputs(f),
 			Request::Body(ref req) => req.note_outputs(f),
 			Request::Account(ref req) => req.note_outputs(f),
@@ -382,6 +395,7 @@ impl IncompleteRequest for Request {
 		match *self {
 			Request::Headers(ref mut req) => req.fill(oracle),
 			Request::HeaderProof(ref mut req) => req.fill(oracle),
+			Request::TransactionIndex(ref mut req) => req.fill(oracle),
 			Request::Receipts(ref mut req) => req.fill(oracle),
 			Request::Body(ref mut req) => req.fill(oracle),
 			Request::Account(ref mut req) => req.fill(oracle),
@@ -395,6 +409,7 @@ impl IncompleteRequest for Request {
 		match self {
 			Request::Headers(req) => req.complete().map(CompleteRequest::Headers),
 			Request::HeaderProof(req) => req.complete().map(CompleteRequest::HeaderProof),
+			Request::TransactionIndex(req) => req.complete().map(CompleteRequest::TransactionIndex),
 			Request::Receipts(req) => req.complete().map(CompleteRequest::Receipts),
 			Request::Body(req) => req.complete().map(CompleteRequest::Body),
 			Request::Account(req) => req.complete().map(CompleteRequest::Account),
@@ -408,6 +423,7 @@ impl IncompleteRequest for Request {
 		match *self {
 			Request::Headers(ref mut req) => req.adjust_refs(mapping),
 			Request::HeaderProof(ref mut req) => req.adjust_refs(mapping),
+			Request::TransactionIndex(ref mut req) => req.adjust_refs(mapping),
 			Request::Receipts(ref mut req) => req.adjust_refs(mapping),
 			Request::Body(ref mut req) => req.adjust_refs(mapping),
 			Request::Account(ref mut req) => req.adjust_refs(mapping),
@@ -441,7 +457,8 @@ pub enum Kind {
 	Headers = 0,
 	/// A request for a header proof.
 	HeaderProof = 1,
-	// TransactionIndex = 2,
+	/// A request for a transaction index.
+	TransactionIndex = 2,
 	/// A request for block receipts.
 	Receipts = 3,
 	/// A request for a block body.
@@ -461,7 +478,7 @@ impl Decodable for Kind {
 		match rlp.as_val::<u8>()? {
 			0 => Ok(Kind::Headers),
 			1 => Ok(Kind::HeaderProof),
-			// 2 => Ok(Kind::TransactionIndex),
+			2 => Ok(Kind::TransactionIndex),
 			3 => Ok(Kind::Receipts),
 			4 => Ok(Kind::Body),
 			5 => Ok(Kind::Account),
@@ -486,7 +503,8 @@ pub enum Response {
 	Headers(HeadersResponse),
 	/// A response for a header proof (from a CHT)
 	HeaderProof(HeaderProofResponse),
-	// TransactionIndex,
+	/// A response for a transaction index.
+	TransactionIndex(TransactionIndexResponse),
 	/// A response for a block's receipts.
 	Receipts(ReceiptsResponse),
 	/// A response for a block body.
@@ -507,6 +525,7 @@ impl ResponseLike for Response {
 		match *self {
 			Response::Headers(ref res) => res.fill_outputs(f),
 			Response::HeaderProof(ref res) => res.fill_outputs(f),
+			Response::TransactionIndex(ref res) => res.fill_outputs(f),
 			Response::Receipts(ref res) => res.fill_outputs(f),
 			Response::Body(ref res) => res.fill_outputs(f),
 			Response::Account(ref res) => res.fill_outputs(f),
@@ -523,6 +542,7 @@ impl Response {
 		match *self {
 			Response::Headers(_) => Kind::Headers,
 			Response::HeaderProof(_) => Kind::HeaderProof,
+			Response::TransactionIndex(_) => Kind::TransactionIndex,
 			Response::Receipts(_) => Kind::Receipts,
 			Response::Body(_) => Kind::Body,
 			Response::Account(_) => Kind::Account,
@@ -538,6 +558,7 @@ impl Decodable for Response {
 		match rlp.val_at::<Kind>(0)? {
 			Kind::Headers => Ok(Response::Headers(rlp.val_at(1)?)),
 			Kind::HeaderProof => Ok(Response::HeaderProof(rlp.val_at(1)?)),
+			Kind::TransactionIndex => Ok(Response::TransactionIndex(rlp.val_at(1)?)),
 			Kind::Receipts => Ok(Response::Receipts(rlp.val_at(1)?)),
 			Kind::Body => Ok(Response::Body(rlp.val_at(1)?)),
 			Kind::Account => Ok(Response::Account(rlp.val_at(1)?)),
@@ -558,6 +579,7 @@ impl Encodable for Response {
 		match *self {
 			Response::Headers(ref res) => s.append(res),
 			Response::HeaderProof(ref res) => s.append(res),
+			Response::TransactionIndex(ref res) => s.append(res),
 			Response::Receipts(ref res) => s.append(res),
 			Response::Body(ref res) => s.append(res),
 			Response::Account(ref res) => s.append(res),
@@ -864,6 +886,117 @@ pub mod header_proof {
 	}
 }
 
+/// Request and response for transaction index.
+pub mod transaction_index {
+	use super::{Field, NoSuchOutput, OutputKind, Output};
+	use rlp::{Encodable, Decodable, DecoderError, RlpStream, UntrustedRlp};
+	use util::H256;
+
+	/// Potentially incomplete transaction index request.
+	#[derive(Debug, Clone, PartialEq, Eq)]
+	pub struct Incomplete {
+		/// Transaction hash to get index for.
+		pub hash: Field<H256>,
+	}
+
+	impl Decodable for Incomplete {
+		fn decode(rlp: &UntrustedRlp) -> Result<Self, DecoderError> {
+			Ok(Incomplete {
+				hash: rlp.val_at(0)?,
+			})
+		}
+	}
+
+	impl Encodable for Incomplete {
+		fn rlp_append(&self, s: &mut RlpStream) {
+			s.begin_list(1).append(&self.hash);
+		}
+	}
+
+	impl super::IncompleteRequest for Incomplete {
+		type Complete = Complete;
+		type Response = Response;
+
+		fn check_outputs<F>(&self, mut f: F) -> Result<(), NoSuchOutput>
+			where F: FnMut(usize, usize, OutputKind) -> Result<(), NoSuchOutput>
+		{
+			match self.hash {
+				Field::Scalar(_) => Ok(()),
+				Field::BackReference(req, idx) => f(req, idx, OutputKind::Hash),
+			}
+		}
+
+		fn note_outputs<F>(&self, mut f: F) where F: FnMut(usize, OutputKind) {
+			f(0, OutputKind::Number);
+			f(1, OutputKind::Hash);
+		}
+
+		fn fill<F>(&mut self, oracle: F) where F: Fn(usize, usize) -> Result<Output, NoSuchOutput> {
+			if let Field::BackReference(req, idx) = self.hash {
+				self.hash = match oracle(req, idx) {
+					Ok(Output::Number(hash)) => Field::Scalar(hash.into()),
+					_ => Field::BackReference(req, idx),
+				}
+			}
+		}
+
+		fn complete(self) -> Result<Self::Complete, NoSuchOutput> {
+			Ok(Complete {
+				hash: self.hash.into_scalar()?,
+			})
+		}
+
+		fn adjust_refs<F>(&mut self, mapping: F) where F: FnMut(usize) -> usize {
+			self.hash.adjust_req(mapping)
+		}
+	}
+
+	/// A complete transaction index request.
+	#[derive(Debug, Clone, PartialEq, Eq)]
+	pub struct Complete {
+		/// The transaction hash to get index for.
+		pub hash: H256,
+	}
+
+	/// The output of a request for transaction index.
+	#[derive(Debug, Clone, PartialEq, Eq)]
+	pub struct Response {
+		/// Block number.
+		pub num: u64,
+		/// Block hash
+		pub hash: H256,
+		/// Index in block.
+		pub index: u64,
+	}
+
+	impl super::ResponseLike for Response {
+		/// Fill reusable outputs by providing them to the function.
+		fn fill_outputs<F>(&self, mut f: F) where F: FnMut(usize, Output) {
+			f(0, Output::Number(self.num));
+			f(1, Output::Hash(self.hash));
+		}
+	}
+
+	impl Decodable for Response {
+		fn decode(rlp: &UntrustedRlp) -> Result<Self, DecoderError> {
+			Ok(Response {
+				num: rlp.val_at(0)?,
+				hash: rlp.val_at(1)?,
+				index: rlp.val_at(2)?,
+			})
+		}
+	}
+
+	impl Encodable for Response {
+		fn rlp_append(&self, s: &mut RlpStream) {
+			s.begin_list(3)
+				.append(&self.num)
+				.append(&self.hash)
+				.append(&self.index);
+		}
+	}
+}
+
 /// Request and response for block receipts
 pub mod block_receipts {
 	use super::{Field, NoSuchOutput, OutputKind, Output};
@@ -1704,6 +1837,26 @@ mod tests {
 		check_roundtrip(full_res);
 	}
 
+	#[test]
+	fn transaction_index_roundtrip() {
+		let req = IncompleteTransactionIndexRequest {
+			hash: Field::Scalar(Default::default()),
+		};
+
+		let full_req = Request::TransactionIndex(req.clone());
+		let res = TransactionIndexResponse {
+			num: 1000,
+			hash: ::util::H256::random(),
+			index: 4,
+		};
+		let full_res = Response::TransactionIndex(res.clone());
+
+		check_roundtrip(req);
+		check_roundtrip(full_req);
+		check_roundtrip(res);
+		check_roundtrip(full_res);
+	}
+
 	#[test]
 	fn receipts_roundtrip() {
 		let req = IncompleteReceiptsRequest {

sync/src/light_sync/mod.rs

@@ -39,8 +39,9 @@ use std::sync::Arc;
 use ethcore::encoded;
 use light::client::{AsLightClient, LightChainClient};
 use light::net::{
-	Announcement, Handler, BasicContext, EventContext,
+	PeerStatus, Announcement, Handler, BasicContext,
-	Capabilities, ReqId, Status, Error as NetError,
+	EventContext, Capabilities, ReqId, Status,
+	Error as NetError,
 };
 use light::request::{self, CompleteHeadersRequest as HeadersRequest};
 use network::PeerId;
@@ -229,26 +230,33 @@ pub struct LightSync<L: AsLightClient> {
 }
 
 impl<L: AsLightClient + Send + Sync> Handler for LightSync<L> {
-	fn on_connect(&self, ctx: &EventContext, status: &Status, capabilities: &Capabilities) {
+	fn on_connect(
-		if !capabilities.serve_headers {
+		&self,
-			trace!(target: "sync", "Disconnecting irrelevant peer: {}", ctx.peer());
+		ctx: &EventContext,
-			ctx.disconnect_peer(ctx.peer());
+		status: &Status,
-			return;
+		capabilities: &Capabilities
+	) -> PeerStatus {
+		use std::cmp;
+
+		if capabilities.serve_headers {
+			let chain_info = ChainInfo {
+				head_td: status.head_td,
+				head_hash: status.head_hash,
+				head_num: status.head_num,
+			};
+
+			{
+				let mut best = self.best_seen.lock();
+				*best = cmp::max(best.clone(), Some(chain_info.clone()));
+			}
+
+			self.peers.write().insert(ctx.peer(), Mutex::new(Peer::new(chain_info)));
+			self.maintain_sync(ctx.as_basic());
+
+			PeerStatus::Kept
+		} else {
+			PeerStatus::Unkept
 		}
-
-		let chain_info = ChainInfo {
-			head_td: status.head_td,
-			head_hash: status.head_hash,
-			head_num: status.head_num,
-		};
-
-		{
-			let mut best = self.best_seen.lock();
-			*best = ::std::cmp::max(best.clone(), Some(chain_info.clone()));
-		}
-
-		self.peers.write().insert(ctx.peer(), Mutex::new(Peer::new(chain_info)));
-		self.maintain_sync(ctx.as_basic());
 	}
 
 	fn on_disconnect(&self, ctx: &EventContext, unfulfilled: &[ReqId]) {