libp2p: distinguish discovery packets by packet type

libp2p/NodeTable.cpp

@@ -383,14 +383,12 @@ void NodeTable::onReceived(UDPSocketFace*, bi::udp::endpoint const& _from, bytes
 	if (packetType && packetType < 4)
 		noteNode(nodeid, _from);
 	
-	// todo: switch packet-type
 	bytesConstRef rlpBytes(_packet.cropped(h256::size + Signature::size + 1));
 	RLP rlp(rlpBytes);
-	unsigned itemCount = rlp.itemCount();
 	try {
-		switch (itemCount)
+		switch (packetType)
 		{
-			case 1:
+			case Pong::type:
 			{
 //				clog(NodeTableMessageSummary) << "Received Pong from " << _from.address().to_string() << ":" << _from.port();
 				Pong in = Pong::fromBytesConstRef(_from, rlpBytes);
@@ -408,35 +406,35 @@ void NodeTable::onReceived(UDPSocketFace*, bi::udp::endpoint const& _from, bytes
 						
 						it = m_evictions.erase(it);
 					}
+				break;
+			}
 				
+			case Neighbours::type:
+			{
+				Neighbours in = Neighbours::fromBytesConstRef(_from, rlpBytes);
+//				clog(NodeTableMessageSummary) << "Received " << in.nodes.size() << " Neighbours from " << _from.address().to_string() << ":" << _from.port();
+				for (auto n: in.nodes)
+					noteNode(n.node, bi::udp::endpoint(bi::address::from_string(n.ipAddress), n.port));
 				break;
 			}
 
-			case 2:
-				if (rlp[0].isList())
-				{
-					Neighbours in = Neighbours::fromBytesConstRef(_from, rlpBytes);
-//					clog(NodeTableMessageSummary) << "Received " << in.nodes.size() << " Neighbours from " << _from.address().to_string() << ":" << _from.port();
-					for (auto n: in.nodes)
-						noteNode(n.node, bi::udp::endpoint(bi::address::from_string(n.ipAddress), n.port));
-				}
-				else
-				{
-//					clog(NodeTableMessageSummary) << "Received FindNode from " << _from.address().to_string() << ":" << _from.port();
-					FindNode in = FindNode::fromBytesConstRef(_from, rlpBytes);
+			case FindNode::type:
+			{
+//				clog(NodeTableMessageSummary) << "Received FindNode from " << _from.address().to_string() << ":" << _from.port();
+				FindNode in = FindNode::fromBytesConstRef(_from, rlpBytes);
 
-					vector<shared_ptr<NodeEntry>> nearest = findNearest(in.target);
-					static unsigned const nlimit = (m_socketPtr->maxDatagramSize - 11) / 86;
-					for (unsigned offset = 0; offset < nearest.size(); offset += nlimit)
-					{
-						Neighbours out(_from, nearest, offset, nlimit);
-						out.sign(m_secret);
-						m_socketPtr->send(out);
-					}
+				vector<shared_ptr<NodeEntry>> nearest = findNearest(in.target);
+				static unsigned const nlimit = (m_socketPtr->maxDatagramSize - 11) / 86;
+				for (unsigned offset = 0; offset < nearest.size(); offset += nlimit)
+				{
+					Neighbours out(_from, nearest, offset, nlimit);
+					out.sign(m_secret);
+					m_socketPtr->send(out);
 				}
 				break;
+			}
 
-			case 3:
+			case PingNode::type:
 			{
 //				clog(NodeTableMessageSummary) << "Received PingNode from " << _from.address().to_string() << ":" << _from.port();
 				PingNode in = PingNode::fromBytesConstRef(_from, rlpBytes);

libp2p/NodeTable.h

@@ -272,7 +272,7 @@ struct PingNode: RLPXDatagram<PingNode>
 	PingNode(bi::udp::endpoint _ep): RLPXDatagram<PingNode>(_ep) {}
 	PingNode(bi::udp::endpoint _ep, std::string _src, uint16_t _srcPort, std::chrono::seconds _expiration = std::chrono::seconds(60)): RLPXDatagram<PingNode>(_ep), ipAddress(_src), port(_srcPort), expiration(futureFromEpoch(_expiration)) {}
 
-	uint8_t packetType() { return 1; }
+	static const uint8_t type = 1;
 	
 	unsigned version = 1;
 	std::string ipAddress;
@@ -294,7 +294,8 @@ struct Pong: RLPXDatagram<Pong>
 {
 	Pong(bi::udp::endpoint _ep): RLPXDatagram<Pong>(_ep), expiration(futureFromEpoch(std::chrono::seconds(60))) {}
 
-	uint8_t packetType() { return 2; }
+	static const uint8_t type = 2;
+
 	h256 echo;				///< MCD of PingNode
 	unsigned expiration;
 	
@@ -320,7 +321,8 @@ struct FindNode: RLPXDatagram<FindNode>
 	FindNode(bi::udp::endpoint _ep): RLPXDatagram<FindNode>(_ep) {}
 	FindNode(bi::udp::endpoint _ep, NodeId _target, std::chrono::seconds _expiration = std::chrono::seconds(30)): RLPXDatagram<FindNode>(_ep), target(_target), expiration(futureFromEpoch(_expiration)) {}
 
-	uint8_t packetType() { return 3; }
+	static const uint8_t type = 3;
+	
 	h512 target;
 	unsigned expiration;
 	
@@ -361,7 +363,7 @@ struct Neighbours: RLPXDatagram<Neighbours>
 		}
 	}
 	
-	uint8_t packetType() { return 4; }
+	static const uint8_t type = 4;
 	std::list<Node> nodes;
 	unsigned expiration = 1;
 

libp2p/UDP.h

@@ -77,6 +77,7 @@ struct RLPXDatagram: public RLPXDatagramFace
 {
 	RLPXDatagram(bi::udp::endpoint const& _ep): RLPXDatagramFace(_ep) {}
 	static T fromBytesConstRef(bi::udp::endpoint const& _ep, bytesConstRef _bytes) { T t(_ep); t.interpretRLP(_bytes); return std::move(t); }
+	uint8_t packetType() { return T::type; }
 };
 
 /**