Various enhancements for P2P networking.

libethereum/PeerNetwork.cpp

@@ -107,6 +107,23 @@ bi::tcp::endpoint PeerSession::endpoint() const
 	return bi::tcp::endpoint();
 }
 
+static std::string reasonOf(int _r)
+{
+	switch (_r)
+	{
+	case DisconnectRequested: return "Disconnect was requested.";
+	case TCPError: return "Low-level TCP communication error.";
+	case BadProtocol: return "Data format error.";
+	case UselessPeer: return "Peer had no use for this node.";
+	case TooManyPeers: return "Peer had too many connections.";
+	case DuplicatePeer: return "Peer was already connected.";
+	case WrongGenesis: return "Disagreement over genesis block.";
+	case IncompatibleProtocol: return "Peer protocol versions are incompatible.";
+	case ClientQuit: return "Peer is exiting.";
+	default: return "Unknown reason.";
+	}
+}
+
 // TODO: BUG! 256 -> work out why things start to break with big packet sizes -> g.t. ~370 blocks.
 
 bool PeerSession::interpret(RLP const& _r)
@@ -125,14 +142,17 @@ bool PeerSession::interpret(RLP const& _r)
 
 		clogS(NetMessageSummary) << "Hello: " << clientVersion << "V[" << m_protocolVersion << "/" << m_networkId << "]" << asHex(m_id.ref().cropped(0, 4)) << showbase << hex << m_caps << dec << m_listenPort;
 
-		if (m_server->m_peers.count(m_id) || !m_id)
+		if (m_server->m_peers.count(m_id))
+			if (auto l = m_server->m_peers[m_id].lock())
+				if (l.get() != this && l->isOpen())
 				{
 					// Already connected.
+					cwarn << "Already have peer id" << m_id << "at" << l->endpoint() << "rather than" << endpoint();
 					disconnect(DuplicatePeer);
+					return false;
 				}
-		m_server->m_peers[m_id] = shared_from_this();
 
-		if (m_protocolVersion != c_protocolVersion || m_networkId != m_reqNetworkId)
+		if (m_protocolVersion != c_protocolVersion || m_networkId != m_reqNetworkId || !m_id)
 		{
 			disconnect(IncompatibleProtocol);
 			return false;
@@ -145,6 +165,8 @@ bool PeerSession::interpret(RLP const& _r)
 			return false;
 		}
 
+		m_server->m_peers[m_id] = shared_from_this();
+
 		// Grab their block chain off them.
 		{
 			unsigned count = std::min<unsigned>(c_maxHashes, m_server->m_chain->details(m_server->m_latestBlockSent).number + 1);
@@ -167,18 +189,7 @@ bool PeerSession::interpret(RLP const& _r)
 	{
 		string reason = "Unspecified";
 		if (_r[1].isInt())
-			switch (_r[1].toInt<int>())
-			{
-			case DisconnectRequested: reason = "Disconnect was requested."; break;
-			case TCPError: reason = "Low-level TCP communication error."; break;
-			case BadProtocol: reason = "Data format error."; break;
-			case UselessPeer: reason = "Peer had no use for this node."; break;
-			case TooManyPeers: reason = "Peer had too many connections."; break;
-			case DuplicatePeer: reason = "Peer was already connected."; break;
-			case WrongGenesis: reason = "Disagreement over genesis block."; break;
-			case IncompatibleProtocol: reason = "Peer protocol versions are incompatible."; break;
-			case ClientQuit: reason = "Peer is exiting."; break;
-			}
+			reason = reasonOf(_r[1].toInt<int>());
 
 		clogS(NetMessageSummary) << "Disconnect (reason: " << reason << ")";
 		if (m_socket.is_open())
@@ -452,7 +463,10 @@ void PeerSession::sendDestroy(bytes& _msg)
 	ba::async_write(m_socket, ba::buffer(*buffer), [=](boost::system::error_code ec, std::size_t length)
 	{
 		if (ec)
+		{
+			cwarn << "Error sending: " << ec.message();
 			dropped();
+		}
 //		cbug << length << " bytes written (EC: " << ec << ")";
 	});
 }
@@ -465,7 +479,10 @@ void PeerSession::send(bytesConstRef _msg)
 	ba::async_write(m_socket, ba::buffer(*buffer), [=](boost::system::error_code ec, std::size_t length)
 	{
 		if (ec)
+		{
+			cwarn << "Error sending: " << ec.message();
 			dropped();
+		}
 //		cbug << length << " bytes written (EC: " << ec << ")";
 	});
 }
@@ -487,6 +504,7 @@ void PeerSession::dropped()
 
 void PeerSession::disconnect(int _reason)
 {
+	clogS(NetNote) << "Disconnecting (reason:" << reasonOf(_reason) << ")";
 	if (m_socket.is_open())
 	{
 		if (m_disconnect == chrono::steady_clock::time_point::max())
@@ -498,15 +516,7 @@ void PeerSession::disconnect(int _reason)
 			m_disconnect = chrono::steady_clock::now();
 		}
 		else
-		{
-			if (m_socket.is_open())
-				try {
-				clogS(NetNote) << "Closing " << m_socket.remote_endpoint();
-				} catch (...){}
-			else
-				clogS(NetNote) << "Remote closed on" << m_socket.native_handle();
-			m_socket.close();
-		}
+			dropped();
 	}
 }
 
@@ -528,7 +538,10 @@ void PeerSession::doRead()
 	m_socket.async_read_some(boost::asio::buffer(m_data), [this, self](boost::system::error_code ec, std::size_t length)
 	{
 		if (ec)
+		{
+			cwarn << "Error reading: " << ec.message();
 			dropped();
+		}
 		else
 		{
 			try
@@ -553,8 +566,11 @@ void PeerSession::doRead()
 //						cerr << "Received " << len << ": " << asHex(bytesConstRef(m_incoming.data() + 8, len)) << endl;
 						RLP r(bytesConstRef(m_incoming.data() + 8, len));
 						if (!interpret(r))
+						{
 							// error
-							break;
+							dropped();
+							return;
+						}
 						memmove(m_incoming.data(), m_incoming.data() + len + 8, m_incoming.size() - (len + 8));
 						m_incoming.resize(m_incoming.size() - (len + 8));
 					}