Cluster simplification and refactor work in progress...

node/Cluster.cpp

@@ -86,7 +86,8 @@ Cluster::Cluster(
 	_peerAffinities(65536),
 	_lastCleanedPeerAffinities(0),
 	_lastCheckedPeersForAnnounce(0),
-	_lastFlushed(0)
+	_lastFlushed(0),
+	_lastCleanedRemotePeers(0)
 {
 	uint16_t stmp[ZT_SHA512_DIGEST_LEN / sizeof(uint16_t)];
 
@@ -107,6 +108,9 @@ Cluster::~Cluster()
 	Utils::burn(_masterSecret,sizeof(_masterSecret));
 	Utils::burn(_key,sizeof(_key));
 	delete [] _members;
+
+	for(std::multimap<Address,_SQE *>::iterator qi(_sendViaClusterQueue.begin());qi!=_sendViaClusterQueue.end();)
+		delete qi->second;
 }
 
 void Cluster::handleIncomingStateMessage(const void *msg,unsigned int len)
@@ -160,222 +164,263 @@ void Cluster::handleIncomingStateMessage(const void *msg,unsigned int len)
 			return;
 	}
 
-	{
-		_Member &m = _members[fromMemberId];
-		Mutex::Lock mlck(m.lock);
-
-		try {
-			while (ptr < dmsg.size()) {
-				const unsigned int mlen = dmsg.at<uint16_t>(ptr); ptr += 2;
-				const unsigned int nextPtr = ptr + mlen;
-				if (nextPtr > dmsg.size())
-					break;
+	_Member &m = _members[fromMemberId];
 
-				int mtype = -1;
-				try {
-					switch((StateMessageType)(mtype = (int)dmsg[ptr++])) {
-						default:
-							break;
-
-						case STATE_MESSAGE_ALIVE: {
-							ptr += 7; // skip version stuff, not used yet
-							m.x = dmsg.at<int32_t>(ptr); ptr += 4;
-							m.y = dmsg.at<int32_t>(ptr); ptr += 4;
-							m.z = dmsg.at<int32_t>(ptr); ptr += 4;
-							ptr += 8; // skip local clock, not used
-							m.load = dmsg.at<uint64_t>(ptr); ptr += 8;
-							m.peers = dmsg.at<uint64_t>(ptr); ptr += 8;
-							ptr += 8; // skip flags, unused
-#ifdef ZT_TRACE
-							std::string addrs;
-#endif
-							unsigned int physicalAddressCount = dmsg[ptr++];
-							m.zeroTierPhysicalEndpoints.clear();
-							for(unsigned int i=0;i<physicalAddressCount;++i) {
-								m.zeroTierPhysicalEndpoints.push_back(InetAddress());
-								ptr += m.zeroTierPhysicalEndpoints.back().deserialize(dmsg,ptr);
-								if (!(m.zeroTierPhysicalEndpoints.back())) {
-									m.zeroTierPhysicalEndpoints.pop_back();
-								}
+	try {
+		while (ptr < dmsg.size()) {
+			const unsigned int mlen = dmsg.at<uint16_t>(ptr); ptr += 2;
+			const unsigned int nextPtr = ptr + mlen;
+			if (nextPtr > dmsg.size())
+				break;
+
+			int mtype = -1;
+			try {
+				switch((StateMessageType)(mtype = (int)dmsg[ptr++])) {
+					default:
+						break;
+
+					case CLUSTER_MESSAGE_ALIVE: {
+						Mutex::Lock mlck(m.lock);
+						ptr += 7; // skip version stuff, not used yet
+						m.x = dmsg.at<int32_t>(ptr); ptr += 4;
+						m.y = dmsg.at<int32_t>(ptr); ptr += 4;
+						m.z = dmsg.at<int32_t>(ptr); ptr += 4;
+						ptr += 8; // skip local clock, not used
+						m.load = dmsg.at<uint64_t>(ptr); ptr += 8;
+						m.peers = dmsg.at<uint64_t>(ptr); ptr += 8;
+						ptr += 8; // skip flags, unused
 #ifdef ZT_TRACE
-								else {
-									if (addrs.length() > 0)
-										addrs.push_back(',');
-									addrs.append(m.zeroTierPhysicalEndpoints.back().toString());
-								}
+						std::string addrs;
 #endif
+						unsigned int physicalAddressCount = dmsg[ptr++];
+						m.zeroTierPhysicalEndpoints.clear();
+						for(unsigned int i=0;i<physicalAddressCount;++i) {
+							m.zeroTierPhysicalEndpoints.push_back(InetAddress());
+							ptr += m.zeroTierPhysicalEndpoints.back().deserialize(dmsg,ptr);
+							if (!(m.zeroTierPhysicalEndpoints.back())) {
+								m.zeroTierPhysicalEndpoints.pop_back();
 							}
 #ifdef ZT_TRACE
-							if ((RR->node->now() - m.lastReceivedAliveAnnouncement) >= ZT_CLUSTER_TIMEOUT) {
-								TRACE("[%u] I'm alive! peers close to %d,%d,%d can be redirected to: %s",(unsigned int)fromMemberId,m.x,m.y,m.z,addrs.c_str());
+							else {
+								if (addrs.length() > 0)
+									addrs.push_back(',');
+								addrs.append(m.zeroTierPhysicalEndpoints.back().toString());
 							}
 #endif
-							m.lastReceivedAliveAnnouncement = RR->node->now();
-						}	break;
-
-						case STATE_MESSAGE_HAVE_PEER: {
-							const Address zeroTierAddress(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
-							Mutex::Lock _l2(_peerAffinities_m);
-							_peerAffinities.set(zeroTierAddress,fromMemberId);
-							TRACE("[%u] has %s @ %s",(unsigned int)fromMemberId,id.address().toString().c_str(),physicalAddress.toString().c_str());
-						}	break;
-
-						case STATE_MESSAGE_WANT_PEER: {
-							const Address zeroTierAddress(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
-							SharedPtr<Peer> peer(RR->topology->getPeerNoCache(zeroTierAddress));
-							if ((peer)&&(peer->hasActiveDirectPath(RR->node->now()))) {
-								char buf[ZT_ADDRESS_LENGTH];
-								peer->address().copyTo(buf,ZT_ADDRESS_LENGTH);
+						}
+#ifdef ZT_TRACE
+						if ((RR->node->now() - m.lastReceivedAliveAnnouncement) >= ZT_CLUSTER_TIMEOUT) {
+							TRACE("[%u] I'm alive! peers close to %d,%d,%d can be redirected to: %s",(unsigned int)fromMemberId,m.x,m.y,m.z,addrs.c_str());
+						}
+#endif
+						m.lastReceivedAliveAnnouncement = RR->node->now();
+					}	break;
+
+					case CLUSTER_MESSAGE_HAVE_PEER: {
+						Identity id;
+						ptr += id.deserialize(dmsg,ptr);
+						if (id) {
+							RR->topology->saveIdentity(id);
+
+							{
+								Mutex::Lock _l(_remotePeers_m);
+								_remotePeers[std::pair<Address,unsigned int>(id.address(),(unsigned int)fromMemberId)] = RR->node->now();
+							}
+
+							std::pair<Address,_SQE *> q[ZT_CLUSTER_MAX_QUEUE_PER_SENDER];
+							unsigned int qc = 0;
+							{
+								Mutex::Lock _l(_sendViaClusterQueue_m);
+								std::pair< std::multimap<Address,_SQE *>::iterator,std::multimap<Address,_SQE>::iterator > er(_sendViaClusterQueue.equal_range(id.address()));
+								for(std::multimap<Address,_SQE *>::iterator qi(er.first);qi!=er.second;) {
+									if (qc >= ZT_CLUSTER_MAX_QUEUE_PER_SENDER) // sanity check
+										break;
+									q[qc++] = *qi;
+									_sendViaClusterQueue.erase(qi++);
+								}
+							}
+							for(unsigned int i=0;i<qc;++i) {
+								this->sendViaCluster(q[i].first,q[i].second->toPeerAddress,q[i].second->data,q[i].second->len,q[i].second->unite);
+								delete q[i].second;
+							}
+
+							TRACE("[%u] has %s",(unsigned int)fromMemberId,id.address().toString().c_str());
+						}
+					}	break;
+
+					case CLUSTER_MESSAGE_WANT_PEER: {
+						const Address zeroTierAddress(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
+						SharedPtr<Peer> peer(RR->topology->getPeerNoCache(zeroTierAddress));
+						if ( (peer) && (peer->hasActiveDirectPath(RR->node->now())) ) {
+								Buffer<1024> buf;
+								peer->identity().serialize(buf);
 								Mutex::Lock _l2(_members[fromMemberId].lock);
-								_send(fromMemberId,STATE_MESSAGE_HAVE_PEER,buf,ZT_ADDRESS_LENGTH);
-								_flush(fromMemberId);
+								_send(fromMemberId,CLUSTER_MESSAGE_HAVE_PEER,buf.data(),buf.size());
+								_flush(fromMemberId); // lookups are latency sensitive
 							}
-						}	break;
-
-						case STATE_MESSAGE_MULTICAST_LIKE: {
-							const uint64_t nwid = dmsg.at<uint64_t>(ptr); ptr += 8;
-							const Address address(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
-							const MAC mac(dmsg.field(ptr,6),6); ptr += 6;
-							const uint32_t adi = dmsg.at<uint32_t>(ptr); ptr += 4;
-							RR->mc->add(RR->node->now(),nwid,MulticastGroup(mac,adi),address);
-							TRACE("[%u] %s likes %s/%.8x on %.16llx",(unsigned int)fromMemberId,address.toString().c_str(),mac.toString().c_str(),(unsigned int)adi,nwid);
-						}	break;
-
-						case STATE_MESSAGE_COM: {
-							/* not currently used so not decoded yet
-							CertificateOfMembership com;
-							ptr += com.deserialize(dmsg,ptr);
-							if (com) {
-								TRACE("[%u] COM for %s on %.16llu rev %llu",(unsigned int)fromMemberId,com.issuedTo().toString().c_str(),com.networkId(),com.revision());
+						}
+					}	break;
+
+					case CLUSTER_MESSAGE_REMOTE_PACKET: {
+						const unsigned int plen = dmsg.at<uint16_t>(ptr); ptr += 2;
+						if (plen) {
+							Packet remotep(dmsg.field(ptr,plen),plen); ptr += plen;
+							TRACE("remote %s from %s via %u (%u bytes)",Packet::verbString(remotep.verb()),remotep.source().toString().c_str(),fromMemberId,plen);
+							switch(remotep.verb()) {
+								case Packet::VERB_WHOIS:            _doREMOTE_WHOIS(fromMemberId,remotep); break;
+								case Packet::VERB_MULTICAST_GATHER: _doREMOTE_MULTICAST_GATHER(fromMemberId,remotep); break;
+								default: break; // ignore things we don't care about across cluster
 							}
-							*/
-						}	break;
-
-						case STATE_MESSAGE_PROXY_UNITE: {
-							const Address localPeerAddress(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
-							const Address remotePeerAddress(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
-							const unsigned int numRemotePeerPaths = dmsg[ptr++];
-							InetAddress remotePeerPaths[256]; // size is 8-bit, so 256 is max
-							for(unsigned int i=0;i<numRemotePeerPaths;++i)
-								ptr += remotePeerPaths[i].deserialize(dmsg,ptr);
-
-							TRACE("[%u] requested that we unite local %s with remote %s",(unsigned int)fromMemberId,localPeerAddress.toString().c_str(),remotePeerAddress.toString().c_str());
-
-							const uint64_t now = RR->node->now();
-							SharedPtr<Peer> localPeer(RR->topology->getPeerNoCache(localPeerAddress));
-							if ((localPeer)&&(numRemotePeerPaths > 0)) {
-								InetAddress bestLocalV4,bestLocalV6;
-								localPeer->getBestActiveAddresses(now,bestLocalV4,bestLocalV6);
-
-								InetAddress bestRemoteV4,bestRemoteV6;
-								for(unsigned int i=0;i<numRemotePeerPaths;++i) {
-									if ((bestRemoteV4)&&(bestRemoteV6))
+						}
+					}	break;
+
+					case CLUSTER_MESSAGE_PROXY_UNITE: {
+						const Address localPeerAddress(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
+						const Address remotePeerAddress(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
+						const unsigned int numRemotePeerPaths = dmsg[ptr++];
+						InetAddress remotePeerPaths[256]; // size is 8-bit, so 256 is max
+						for(unsigned int i=0;i<numRemotePeerPaths;++i)
+							ptr += remotePeerPaths[i].deserialize(dmsg,ptr);
+
+						TRACE("[%u] requested that we unite local %s with remote %s",(unsigned int)fromMemberId,localPeerAddress.toString().c_str(),remotePeerAddress.toString().c_str());
+
+						const uint64_t now = RR->node->now();
+						SharedPtr<Peer> localPeer(RR->topology->getPeerNoCache(localPeerAddress));
+						if ((localPeer)&&(numRemotePeerPaths > 0)) {
+							InetAddress bestLocalV4,bestLocalV6;
+							localPeer->getBestActiveAddresses(now,bestLocalV4,bestLocalV6);
+
+							InetAddress bestRemoteV4,bestRemoteV6;
+							for(unsigned int i=0;i<numRemotePeerPaths;++i) {
+								if ((bestRemoteV4)&&(bestRemoteV6))
+									break;
+								switch(remotePeerPaths[i].ss_family) {
+									case AF_INET:
+										if (!bestRemoteV4)
+											bestRemoteV4 = remotePeerPaths[i];
+										break;
+									case AF_INET6:
+										if (!bestRemoteV6)
+											bestRemoteV6 = remotePeerPaths[i];
 										break;
-									switch(remotePeerPaths[i].ss_family) {
-										case AF_INET:
-											if (!bestRemoteV4)
-												bestRemoteV4 = remotePeerPaths[i];
-											break;
-										case AF_INET6:
-											if (!bestRemoteV6)
-												bestRemoteV6 = remotePeerPaths[i];
-											break;
-									}
 								}
+							}
 
-								Packet rendezvousForLocal(localPeerAddress,RR->identity.address(),Packet::VERB_RENDEZVOUS);
-								rendezvousForLocal.append((uint8_t)0);
-								remotePeerAddress.appendTo(rendezvousForLocal);
-
-								Buffer<2048> rendezvousForRemote;
-								remotePeerAddress.appendTo(rendezvousForRemote);
-								rendezvousForRemote.append((uint8_t)Packet::VERB_RENDEZVOUS);
-								const unsigned int rendezvousForOtherEndPayloadSizePtr = rendezvousForRemote.size();
-								rendezvousForRemote.addSize(2); // space for actual packet payload length
-								rendezvousForRemote.append((uint8_t)0); // flags == 0
-								localPeerAddress.appendTo(rendezvousForRemote);
-
-								bool haveMatch = false;
-								if ((bestLocalV6)&&(bestRemoteV6)) {
-									haveMatch = true;
-
-									rendezvousForLocal.append((uint16_t)bestRemoteV6.port());
-									rendezvousForLocal.append((uint8_t)16);
-									rendezvousForLocal.append(bestRemoteV6.rawIpData(),16);
-
-									rendezvousForRemote.append((uint16_t)bestLocalV6.port());
-									rendezvousForRemote.append((uint8_t)16);
-									rendezvousForRemote.append(bestLocalV6.rawIpData(),16);
-									rendezvousForRemote.setAt<uint16_t>(rendezvousForOtherEndPayloadSizePtr,(uint16_t)(9 + 16));
-								} else if ((bestLocalV4)&&(bestRemoteV4)) {
-									haveMatch = true;
-
-									rendezvousForLocal.append((uint16_t)bestRemoteV4.port());
-									rendezvousForLocal.append((uint8_t)4);
-									rendezvousForLocal.append(bestRemoteV4.rawIpData(),4);
-
-									rendezvousForRemote.append((uint16_t)bestLocalV4.port());
-									rendezvousForRemote.append((uint8_t)4);
-									rendezvousForRemote.append(bestLocalV4.rawIpData(),4);
-									rendezvousForRemote.setAt<uint16_t>(rendezvousForOtherEndPayloadSizePtr,(uint16_t)(9 + 4));
-								}
+							Packet rendezvousForLocal(localPeerAddress,RR->identity.address(),Packet::VERB_RENDEZVOUS);
+							rendezvousForLocal.append((uint8_t)0);
+							remotePeerAddress.appendTo(rendezvousForLocal);
+
+							Buffer<2048> rendezvousForRemote;
+							remotePeerAddress.appendTo(rendezvousForRemote);
+							rendezvousForRemote.append((uint8_t)Packet::VERB_RENDEZVOUS);
+							const unsigned int rendezvousForOtherEndPayloadSizePtr = rendezvousForRemote.size();
+							rendezvousForRemote.addSize(2); // space for actual packet payload length
+							rendezvousForRemote.append((uint8_t)0); // flags == 0
+							localPeerAddress.appendTo(rendezvousForRemote);
+
+							bool haveMatch = false;
+							if ((bestLocalV6)&&(bestRemoteV6)) {
+								haveMatch = true;
+
+								rendezvousForLocal.append((uint16_t)bestRemoteV6.port());
+								rendezvousForLocal.append((uint8_t)16);
+								rendezvousForLocal.append(bestRemoteV6.rawIpData(),16);
+
+								rendezvousForRemote.append((uint16_t)bestLocalV6.port());
+								rendezvousForRemote.append((uint8_t)16);
+								rendezvousForRemote.append(bestLocalV6.rawIpData(),16);
+								rendezvousForRemote.setAt<uint16_t>(rendezvousForOtherEndPayloadSizePtr,(uint16_t)(9 + 16));
+							} else if ((bestLocalV4)&&(bestRemoteV4)) {
+								haveMatch = true;
+
+								rendezvousForLocal.append((uint16_t)bestRemoteV4.port());
+								rendezvousForLocal.append((uint8_t)4);
+								rendezvousForLocal.append(bestRemoteV4.rawIpData(),4);
+
+								rendezvousForRemote.append((uint16_t)bestLocalV4.port());
+								rendezvousForRemote.append((uint8_t)4);
+								rendezvousForRemote.append(bestLocalV4.rawIpData(),4);
+								rendezvousForRemote.setAt<uint16_t>(rendezvousForOtherEndPayloadSizePtr,(uint16_t)(9 + 4));
+							}
 
-								if (haveMatch) {
-									_send(fromMemberId,STATE_MESSAGE_PROXY_SEND,rendezvousForRemote.data(),rendezvousForRemote.size());
-									_flush(fromMemberId);
-									RR->sw->send(rendezvousForLocal,true,0);
-								}
+							if (haveMatch) {
+								_send(fromMemberId,CLUSTER_MESSAGE_PROXY_SEND,rendezvousForRemote.data(),rendezvousForRemote.size());
+								_flush(fromMemberId);
+								RR->sw->send(rendezvousForLocal,true,0);
 							}
-						}	break;
-
-						case STATE_MESSAGE_PROXY_SEND: {
-							const Address rcpt(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
-							const Packet::Verb verb = (Packet::Verb)dmsg[ptr++];
-							const unsigned int len = dmsg.at<uint16_t>(ptr); ptr += 2;
-							Packet outp(rcpt,RR->identity.address(),verb);
-							outp.append(dmsg.field(ptr,len),len); ptr += len;
-							RR->sw->send(outp,true,0);
-							TRACE("[%u] proxy send %s to %s length %u",(unsigned int)fromMemberId,Packet::verbString(verb),rcpt.toString().c_str(),len);
-						}	break;
-					}
-				} catch ( ... ) {
-					TRACE("invalid message of size %u type %d (inner decode), discarding",mlen,mtype);
-					// drop invalids
+						}
+					}	break;
+
+					case CLUSTER_MESSAGE_PROXY_SEND: {
+						const Address rcpt(dmsg.field(ptr,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); ptr += ZT_ADDRESS_LENGTH;
+						const Packet::Verb verb = (Packet::Verb)dmsg[ptr++];
+						const unsigned int len = dmsg.at<uint16_t>(ptr); ptr += 2;
+						Packet outp(rcpt,RR->identity.address(),verb);
+						outp.append(dmsg.field(ptr,len),len); ptr += len;
+						RR->sw->send(outp,true,0);
+						//TRACE("[%u] proxy send %s to %s length %u",(unsigned int)fromMemberId,Packet::verbString(verb),rcpt.toString().c_str(),len);
+					}	break;
 				}
-
-				ptr = nextPtr;
+			} catch ( ... ) {
+				TRACE("invalid message of size %u type %d (inner decode), discarding",mlen,mtype);
+				// drop invalids
 			}
-		} catch ( ... ) {
-			TRACE("invalid message (outer loop), discarding");
-			// drop invalids
+
+			ptr = nextPtr;
 		}
+	} catch ( ... ) {
+		TRACE("invalid message (outer loop), discarding");
+		// drop invalids
 	}
 }
 
 bool Cluster::sendViaCluster(const Address &fromPeerAddress,const Address &toPeerAddress,const void *data,unsigned int len,bool unite)
 {
-	if (len > 16384) // sanity check
+	if (len > ZT_PROTO_MAX_PACKET_LENGTH) // sanity check
 		return false;
 
 	const uint64_t now = RR->node->now();
 	unsigned int canHasPeer = 0;
 
+	uint64_t mostRecentTs = 0;
+	unsigned int mostRecentMemberId = 0xffffffff;
 	{
-		Mutex::Lock _l2(_peerAffinities_m);
-		const unsigned int *pa = _peerAffinities.get(toPeerAddress);
-		if (!pa) {
-			char buf[ZT_ADDRESS_LENGTH];
-			peerId.address().copyTo(buf,ZT_ADDRESS_LENGTH);
-			{
-				Mutex::Lock _l(_memberIds_m);
-				for(std::vector<uint16_t>::const_iterator mid(_memberIds.begin());mid!=_memberIds.end();++mid) {
-					Mutex::Lock _l2(_members[*mid].lock);
-					_send(*mid,STATE_MESSAGE_WANT_PEER,buf,ZT_ADDRESS_LENGTH);
-				}
+		Mutex::Lock _l2(_remotePeers_m);
+		std::map< std::pair<Address,unsigned int>,uint64_t >::const_iterator rpe(_remotePeers.lower_bound(std::pair<Address,unsigned int>(fromPeerAddress,0)));
+		for(;;) {
+			if ((rpe == _remotePeers.end())||(rpe->first.first != fromPeerAddress))
+				break;
+			else if (rpe->second > mostRecentTs) {
+				mostRecentTs = rpe->second;
+				mostRecentMemberId = rpe->first.second;
 			}
-			return false;
 		}
-		canHasPeer = *pa;
+	}
+
+	const uint64_t age = now - mostRecentTs;
+	if (age >= (ZT_PEER_ACTIVITY_TIMEOUT / 3)) {
+		// Poll everyone with WANT_PEER if the age of our most recent entry is
+		// approaching expiration (or has expired, or does not exist).
+		char tmp[ZT_ADDRESS_LENGTH];
+		toPeerAddress.copyTo(tmp,ZT_ADDRESS_LENGTH);
+		{
+			Mutex::Lock _l(_memberIds_m);
+			for(std::vector<uint16_t>::const_iterator mid(_memberIds.begin());mid!=_memberIds.end();++mid) {
+				Mutex::Lock _l2(_members[*mid].lock);
+				_send(*mid,CLUSTER_MESSAGE_WANT_PEER,tmp,ZT_ADDRESS_LENGTH);
+				if (mostRecentMemberId > 0xffff)
+					_flush(*mid); // latency sensitive if we don't have one
+			}
+		}
+
+		// If there isn't a good place to send via, then enqueue this for retrying
+		// later and return after having broadcasted a WANT_PEER.
+		if ((age >= ZT_PEER_ACTIVITY_TIMEOUT)||(mostRecentMemberId > 0xffff)) {
+			Mutex::Lock _l(_sendViaClusterQueue_m);
+			if (_sendViaClusterQueue.count(fromPeerAddress) < ZT_CLUSTER_MAX_QUEUE_PER_SENDER)
+				_sendViaClusterQueue.insert(std::pair<Address,_SQE *>(fromPeerAddress,new _SQE(now,toPeerAddress,data,len,unite)));
+			return true;
+		}
 	}
 
 	Buffer<1024> buf;
@@ -401,11 +446,14 @@ bool Cluster::sendViaCluster(const Address &fromPeerAddress,const Address &toPee
 				v6.serialize(buf);
 		}
 	}
+
 	{
-		Mutex::Lock _l2(_members[canHasPeer].lock);
-		if (buf.size() > 0)
-			_send(canHasPeer,STATE_MESSAGE_PROXY_UNITE,buf.data(),buf.size());
-		if (_members[canHasPeer].zeroTierPhysicalEndpoints.size() > 0)
+		Mutex::Lock _l2(_members[mostRecentMemberId].lock);
+		if (buf.size() > 0) {
+			_send(canHasPeer,CLUSTER_MESSAGE_PROXY_UNITE,buf.data(),buf.size());
+			_flush(canHasPeer); // latency sensitive
+		}
+		if (_members[mostRecentMemberId].zeroTierPhysicalEndpoints.size() > 0)
 			RR->node->putPacket(InetAddress(),_members[canHasPeer].zeroTierPhysicalEndpoints.front(),data,len);
 	}
 
@@ -414,62 +462,43 @@ bool Cluster::sendViaCluster(const Address &fromPeerAddress,const Address &toPee
 	return true;
 }
 
-void Cluster::replicateHavePeer(const Identity &peerId)
-{
-	char buf[ZT_ADDRESS_LENGTH];
-	peerId.address().copyTo(buf,ZT_ADDRESS_LENGTH);
-	{
-		Mutex::Lock _l(_memberIds_m);
-		for(std::vector<uint16_t>::const_iterator mid(_memberIds.begin());mid!=_memberIds.end();++mid) {
-			Mutex::Lock _l2(_members[*mid].lock);
-			_send(*mid,STATE_MESSAGE_HAVE_PEER,buf,ZT_ADDRESS_LENGTH);
-		}
-	}
-}
-
-void Cluster::replicateMulticastLike(uint64_t nwid,const Address &peerAddress,const MulticastGroup &group)
-{
-	Buffer<1024> buf;
-	buf.append((uint64_t)nwid);
-	peerAddress.appendTo(buf);
-	group.mac().appendTo(buf);
-	buf.append((uint32_t)group.adi());
-	TRACE("replicating %s MULTICAST_LIKE %.16llx/%s/%u to all members",peerAddress.toString().c_str(),nwid,group.mac().toString().c_str(),(unsigned int)group.adi());
-	{
-		Mutex::Lock _l(_memberIds_m);
-		for(std::vector<uint16_t>::const_iterator mid(_memberIds.begin());mid!=_memberIds.end();++mid) {
-			Mutex::Lock _l2(_members[*mid].lock);
-			_send(*mid,STATE_MESSAGE_MULTICAST_LIKE,buf.data(),buf.size());
-		}
-	}
-}
-
-void Cluster::replicateCertificateOfNetworkMembership(const CertificateOfMembership &com)
+void Cluster::sendDistributedQuery(const Packet &pkt)
 {
-	/* not used yet, so don't do this yet
 	Buffer<4096> buf;
-	com.serialize(buf);
-	TRACE("replicating %s COM for %.16llx to all members",com.issuedTo().toString().c_str(),com.networkId());
-	{
-		Mutex::Lock _l(_memberIds_m);
-		for(std::vector<uint16_t>::const_iterator mid(_memberIds.begin());mid!=_memberIds.end();++mid) {
-			Mutex::Lock _l2(_members[*mid].lock);
-			_send(*mid,STATE_MESSAGE_COM,buf.data(),buf.size());
-		}
+	buf.append((uint16_t)pkt.size());
+	buf.append(pkt.data(),pkt.size());
+	Mutex::Lock _l(_memberIds_m);
+	for(std::vector<uint16_t>::const_iterator mid(_memberIds.begin());mid!=_memberIds.end();++mid) {
+		Mutex::Lock _l2(_members[*mid].lock);
+		_send(*mid,CLUSTER_MESSAGE_REMOTE_PACKET,buf.data(),buf.size());
+		_flush(*mid); // these tend to be latency-sensitive
 	}
-	*/
 }
 
 void Cluster::doPeriodicTasks()
 {
 	const uint64_t now = RR->node->now();
+
 	if ((now - _lastFlushed) >= ZT_CLUSTER_FLUSH_PERIOD) {
 		_lastFlushed = now;
+
+		{
+			Mutex::Lock _l2(_sendViaClusterQueue_m);
+			for(std::multimap<Address,_SQE *>::iterator qi(_sendViaClusterQueue.begin());qi!=_sendViaClusterQueue.end();) {
+				if ((now - qi->second->timestamp) >= ZT_CLUSTER_QUEUE_EXPIRATION) {
+					delete qi->second;
+					_sendViaClusterQueue.erase(qi++);
+				} else ++qi;
+			}
+		}
+
 		Mutex::Lock _l(_memberIds_m);
 		for(std::vector<uint16_t>::const_iterator mid(_memberIds.begin());mid!=_memberIds.end();++mid) {
 			Mutex::Lock _l2(_members[*mid].lock);
 
 			if ((now - _members[*mid].lastAnnouncedAliveTo) >= ((ZT_CLUSTER_TIMEOUT / 2) - 1000)) {
+				_members[*mid].lastAnnouncedAliveTo = now;
+
 				Buffer<2048> alive;
 				alive.append((uint16_t)ZEROTIER_ONE_VERSION_MAJOR);
 				alive.append((uint16_t)ZEROTIER_ONE_VERSION_MINOR);
@@ -491,13 +520,23 @@ void Cluster::doPeriodicTasks()
 				alive.append((uint8_t)_zeroTierPhysicalEndpoints.size());
 				for(std::vector<InetAddress>::const_iterator pe(_zeroTierPhysicalEndpoints.begin());pe!=_zeroTierPhysicalEndpoints.end();++pe)
 					pe->serialize(alive);
-				_send(*mid,STATE_MESSAGE_ALIVE,alive.data(),alive.size());
-				_members[*mid].lastAnnouncedAliveTo = now;
+				_send(*mid,CLUSTER_MESSAGE_ALIVE,alive.data(),alive.size());
 			}
 
 			_flush(*mid); // does nothing if nothing to flush
 		}
 	}
+
+	if ((now - _lastCleanedRemotePeers) >= (ZT_PEER_ACTIVITY_TIMEOUT * 2)) {
+		_lastCleanedRemotePeers = now;
+
+		Mutex::Lock _l(_remotePeers_m);
+		for(std::map< std::pair<Address,unsigned int>,uint64_t >::iterator rp(_remotePeers.begin());rp!=_remotePeers.end();) {
+			if ((now - rp->second) >= ZT_PEER_ACTIVITY_TIMEOUT)
+				_remotePeers.erase(rp++);
+			else ++rp;
+		}
+	}
 }
 
 void Cluster::addMember(uint16_t memberId)

node/Cluster.hpp

@@ -32,6 +32,8 @@
 
 #include <vector>
 #include <algorithm>
+#include <map>
+#include <utility>
 
 #include "Constants.hpp"
 #include "../include/ZeroTierOne.h"
@@ -62,6 +64,16 @@
  */
 #define ZT_CLUSTER_FLUSH_PERIOD 500
 
+/**
+ * Maximum number of queued outgoing packets per sender address
+ */
+#define ZT_CLUSTER_MAX_QUEUE_PER_SENDER 8
+
+/**
+ * Expiration time for send queue entries
+ */
+#define ZT_CLUSTER_QUEUE_EXPIRATION 2500
+
 namespace ZeroTier {
 
 class RuntimeEnvironment;
@@ -98,7 +110,7 @@ public:
 	 */
 	enum StateMessageType
 	{
-		STATE_MESSAGE_NOP = 0,
+		CLUSTER_MESSAGE_NOP = 0,
 
 		/**
 		 * This cluster member is alive:
@@ -115,35 +127,46 @@ public:
 		 *   <[8] flags (currently unused, must be zero)>
 		 *   <[1] number of preferred ZeroTier endpoints>
 		 *   <[...] InetAddress(es) of preferred ZeroTier endpoint(s)>
+		 *
+		 * Cluster members constantly broadcast an alive heartbeat and will only
+		 * receive peer redirects if they've done so within the timeout.
 		 */
-		STATE_MESSAGE_ALIVE = 1,
+		CLUSTER_MESSAGE_ALIVE = 1,
 
 		/**
 		 * Cluster member has this peer:
-		 *   <[5] ZeroTier address of peer>
+		 *   <[...] serialized identity of peer>
+		 *
+		 * This is typically sent in response to WANT_PEER but can also be pushed
+		 * to prepopulate if this makes sense.
 		 */
-		STATE_MESSAGE_HAVE_PEER = 2,
+		CLUSTER_MESSAGE_HAVE_PEER = 2,
 
 		/**
 		 * Cluster member wants this peer:
 		 *   <[5] ZeroTier address of peer>
+		 *
+		 * Members that have a direct link to this peer will respond with
+		 * HAVE_PEER.
 		 */
-		STATE_MESSAGE_WANT_PEER = 3,
-
-		/**
-		 * Peer subscription to multicast group:
-		 *   <[8] network ID>
-		 *   <[5] peer ZeroTier address>
-		 *   <[6] MAC address of multicast group>
-		 *   <[4] 32-bit multicast group ADI>
-		 */
-		STATE_MESSAGE_MULTICAST_LIKE = 4,
+		CLUSTER_MESSAGE_WANT_PEER = 3,
 
 		/**
-		 * Certificate of network membership for a peer:
-		 *   <[...] serialized COM>
+		 * A remote packet that we should also possibly respond to:
+		 *   <[2] 16-bit length of remote packet>
+		 *   <[...] remote packet payload>
+		 *
+		 * Cluster members may relay requests by relaying the request packet.
+		 * These may include requests such as WHOIS and MULTICAST_GATHER. The
+		 * packet must be already decrypted, decompressed, and authenticated.
+		 *
+		 * This can only be used for small request packets as per the cluster
+		 * message size limit, but since these are the only ones in question
+		 * this is fine.
+		 *
+		 * If a response is generated it is sent via PROXY_SEND.
 		 */
-		STATE_MESSAGE_COM = 5,
+		CLUSTER_MESSAGE_REMOTE_PACKET = 4,
 
 		/**
 		 * Request that VERB_RENDEZVOUS be sent to a peer that we have:
@@ -157,7 +180,7 @@ public:
 		 * info for its peer, and we send VERB_RENDEZVOUS to both sides: to ours
 		 * directly and with PROXY_SEND to theirs.
 		 */
-		STATE_MESSAGE_PROXY_UNITE = 6,
+		CLUSTER_MESSAGE_PROXY_UNITE = 5,
 
 		/**
 		 * Request that a cluster member send a packet to a locally-known peer:
@@ -173,7 +196,7 @@ public:
 		 * while PROXY_SEND is used to implement proxy sending (which right
 		 * now is only used to send RENDEZVOUS).
 		 */
-		STATE_MESSAGE_PROXY_SEND = 7,
+		CLUSTER_MESSAGE_PROXY_SEND = 6,
 
 		/**
 		 * Replicate a network config for a network we belong to:
@@ -186,7 +209,7 @@ public:
 		 *
 		 * TODO: not implemented yet!
 		 */
-		STATE_MESSAGE_NETWORK_CONFIG = 8
+		CLUSTER_MESSAGE_NETWORK_CONFIG = 7
 	};
 
 	/**
@@ -222,37 +245,28 @@ public:
 	/**
 	 * Send this packet via another node in this cluster if another node has this peer
 	 *
+	 * This is used in the outgoing packet and relaying logic in Switch to
+	 * relay packets to other cluster members. It isn't PROXY_SEND-- that is
+	 * used internally in Cluster to send responses to peer queries.
+	 *
 	 * @param fromPeerAddress Source peer address (if known, should be NULL for fragments)
 	 * @param toPeerAddress Destination peer address
 	 * @param data Packet or packet fragment data
 	 * @param len Length of packet or fragment
 	 * @param unite If true, also request proxy unite across cluster
-	 * @return True if this data was sent via another cluster member, false if none have this peer
-	 */
-	bool sendViaCluster(const Address &fromPeerAddress,const Address &toPeerAddress,const void *data,unsigned int len,bool unite);
-
-	/**
-	 * Advertise to the cluster that we have this peer
-	 *
-	 * @param peerId Identity of peer that we have
 	 */
-	void replicateHavePeer(const Identity &peerId);
+	void sendViaCluster(const Address &fromPeerAddress,const Address &toPeerAddress,const void *data,unsigned int len,bool unite);
 
 	/**
-	 * Advertise a multicast LIKE to the cluster
+	 * Send a distributed query to other cluster members
 	 *
-	 * @param nwid Network ID
-	 * @param peerAddress Peer address that sent LIKE
-	 * @param group Multicast group
-	 */
-	void replicateMulticastLike(uint64_t nwid,const Address &peerAddress,const MulticastGroup &group);
-
-	/**
-	 * Advertise a network COM to the cluster
+	 * Some queries such as WHOIS or MULTICAST_GATHER need a response from other
+	 * cluster members. Replies (if any) will be sent back to the peer via
+	 * PROXY_SEND across the cluster.
 	 *
-	 * @param com Certificate of network membership (contains peer and network ID)
+	 * @param pkt Packet to distribute
 	 */
-	void replicateCertificateOfNetworkMembership(const CertificateOfMembership &com);
+	void sendDistributedQuery(const Packet &pkt);
 
 	/**
 	 * Call every ~ZT_CLUSTER_PERIODIC_TASK_PERIOD milliseconds.
@@ -295,6 +309,9 @@ private:
 	void _send(uint16_t memberId,StateMessageType type,const void *msg,unsigned int len);
 	void _flush(uint16_t memberId);
 
+	void _doREMOTE_WHOIS(uint64_t fromMemberId,const Packet &remotep);
+	void _doREMOTE_MULTICAST_GATHER(uint64_t fromMemberId,const Packet &remotep);
+
 	// These are initialized in the constructor and remain immutable
 	uint16_t _masterSecret[ZT_SHA512_DIGEST_LEN / sizeof(uint16_t)];
 	unsigned char _key[ZT_PEER_SECRET_KEY_LENGTH];
@@ -348,10 +365,28 @@ private:
 	std::vector<uint16_t> _memberIds;
 	Mutex _memberIds_m;
 
-	Hashtable< Address,unsigned int > _peerAffinities;
-	Mutex _peerAffinities_m;
+	std::map< std::pair<Address,unsigned int>,uint64_t > _remotePeers; // we need ordered behavior and lower_bound here
+	Mutex _remotePeers_m;
+
+	struct _SQE
+	{
+		_SQE() : timestamp(0),len(0),unite(false) {}
+		_SQE(const uint64_t ts,const Address &t,const void *d,const unsigned int l,const bool u) :
+			timestamp(ts),
+			toPeerAddress(t),
+			len(l),
+			unite(u) { memcpy(data,d,l); }
+		uint64_t timestamp;
+		Address toPeerAddress;
+		unsigned int len;
+		bool unite;
+		unsigned char data[ZT_PROTO_MAX_PACKET_LENGTH];
+	};
+	std::multimap<Address,_SQE *> _sendViaClusterQueue; // queue by from peer address
+	Mutex _sendViaClusterQueue_m;
 
 	uint64_t _lastFlushed;
+	uint64_t _lastCleanedRemotePeers;
 };
 
 } // namespace ZeroTier

node/IncomingPacket.cpp

@@ -133,10 +133,7 @@ bool IncomingPacket::_doERROR(const RuntimeEnvironment *RR,const SharedPtr<Peer>
 		switch(errorCode) {
 
 			case Packet::ERROR_OBJ_NOT_FOUND:
-				if (inReVerb == Packet::VERB_WHOIS) {
-					if (RR->topology->isUpstream(peer->identity()))
-						RR->sw->cancelWhoisRequest(Address(field(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH));
-				} else if (inReVerb == Packet::VERB_NETWORK_CONFIG_REQUEST) {
+				if (inReVerb == Packet::VERB_NETWORK_CONFIG_REQUEST) {
 					SharedPtr<Network> network(RR->node->network(at<uint64_t>(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD)));
 					if ((network)&&(network->controller() == peer->address()))
 						network->setNotFound();
@@ -237,7 +234,7 @@ bool IncomingPacket::_doHELLO(const RuntimeEnvironment *RR,SharedPtr<Peer> &peer
 			return true;
 		}
 
-		if (!peer) {
+		if (!peer) { // peer == NULL is the normal case here
 			peer = RR->topology->getPeer(id.address());
 			if (peer) {
 				// We already have an identity with this address -- check for collisions
@@ -452,10 +449,6 @@ bool IncomingPacket::_doOK(const RuntimeEnvironment *RR,const SharedPtr<Peer> &p
 					CertificateOfMembership com;
 					offset += com.deserialize(*this,ZT_PROTO_VERB_MULTICAST_FRAME__OK__IDX_COM_AND_GATHER_RESULTS);
 					peer->validateAndSetNetworkMembershipCertificate(RR,nwid,com);
-#ifdef ZT_ENABLE_CLUSTER
-					if (RR->cluster)
-						RR->cluster->replicateCertificateOfNetworkMembership(com);
-#endif
 				}
 
 				if ((flags & 0x02) != 0) {
@@ -491,14 +484,10 @@ bool IncomingPacket::_doWHOIS(const RuntimeEnvironment *RR,const SharedPtr<Peer>
 				RR->antiRec->logOutgoingZT(outp.data(),outp.size());
 				RR->node->putPacket(_localAddress,_remoteAddress,outp.data(),outp.size());
 			} else {
-				Packet outp(peer->address(),RR->identity.address(),Packet::VERB_ERROR);
-				outp.append((unsigned char)Packet::VERB_WHOIS);
-				outp.append(packetId());
-				outp.append((unsigned char)Packet::ERROR_OBJ_NOT_FOUND);
-				outp.append(payload(),ZT_ADDRESS_LENGTH);
-				outp.armor(peer->key(),true);
-				RR->antiRec->logOutgoingZT(outp.data(),outp.size());
-				RR->node->putPacket(_localAddress,_remoteAddress,outp.data(),outp.size());
+#ifdef ZT_ENABLE_CLUSTER
+				if (RR->cluster)
+					RR->cluster->sendDistributedQuery(*this);
+#endif
 			}
 		} else {
 			TRACE("dropped WHOIS from %s(%s): missing or invalid address",source().toString().c_str(),_remoteAddress.toString().c_str());
@@ -585,10 +574,6 @@ bool IncomingPacket::_doEXT_FRAME(const RuntimeEnvironment *RR,const SharedPtr<P
 					CertificateOfMembership com;
 					comLen = com.deserialize(*this,ZT_PROTO_VERB_EXT_FRAME_IDX_COM);
 					peer->validateAndSetNetworkMembershipCertificate(RR,network->id(),com);
-#ifdef ZT_ENABLE_CLUSTER
-					if (RR->cluster)
-						RR->cluster->replicateCertificateOfNetworkMembership(com);
-#endif
 				}
 
 				if (!network->isAllowed(peer)) {
@@ -674,10 +659,6 @@ bool IncomingPacket::_doMULTICAST_LIKE(const RuntimeEnvironment *RR,const Shared
 			const uint64_t nwid = at<uint64_t>(ptr);
 			const MulticastGroup group(MAC(field(ptr + 8,6),6),at<uint32_t>(ptr + 14));
 			RR->mc->add(now,nwid,group,peer->address());
-#ifdef ZT_ENABLE_CLUSTER
-			if (RR->cluster)
-				RR->cluster->replicateMulticastLike(nwid,peer->address(),group);
-#endif
 		}
 
 		peer->received(RR,_localAddress,_remoteAddress,hops(),packetId(),Packet::VERB_MULTICAST_LIKE,0,Packet::VERB_NOP);
@@ -696,10 +677,6 @@ bool IncomingPacket::_doNETWORK_MEMBERSHIP_CERTIFICATE(const RuntimeEnvironment
 		while (ptr < size()) {
 			ptr += com.deserialize(*this,ptr);
 			peer->validateAndSetNetworkMembershipCertificate(RR,com.networkId(),com);
-#ifdef ZT_ENABLE_CLUSTER
-			if (RR->cluster)
-				RR->cluster->replicateCertificateOfNetworkMembership(com);
-#endif
 		}
 
 		peer->received(RR,_localAddress,_remoteAddress,hops(),packetId(),Packet::VERB_NETWORK_MEMBERSHIP_CERTIFICATE,0,Packet::VERB_NOP);
@@ -831,11 +808,17 @@ bool IncomingPacket::_doMULTICAST_GATHER(const RuntimeEnvironment *RR,const Shar
 			outp.append(nwid);
 			mg.mac().appendTo(outp);
 			outp.append((uint32_t)mg.adi());
-			if (RR->mc->gather(peer->address(),nwid,mg,outp,gatherLimit)) {
+			const unsigned int gatheredLocally = RR->mc->gather(peer->address(),nwid,mg,outp,gatherLimit);
+			if (gatheredLocally) {
 				outp.armor(peer->key(),true);
 				RR->antiRec->logOutgoingZT(outp.data(),outp.size());
 				RR->node->putPacket(_localAddress,_remoteAddress,outp.data(),outp.size());
 			}
+
+#ifdef ZT_ENABLE_CLUSTER
+			if ((RR->cluster)&&(gatheredLocally < gatherLimit))
+				RR->cluster->sendDistributedQuery(*this);
+#endif
 		}
 
 		peer->received(RR,_localAddress,_remoteAddress,hops(),packetId(),Packet::VERB_MULTICAST_GATHER,0,Packet::VERB_NOP);
@@ -860,10 +843,6 @@ bool IncomingPacket::_doMULTICAST_FRAME(const RuntimeEnvironment *RR,const Share
 				CertificateOfMembership com;
 				offset += com.deserialize(*this,ZT_PROTO_VERB_MULTICAST_FRAME_IDX_COM);
 				peer->validateAndSetNetworkMembershipCertificate(RR,nwid,com);
-#ifdef ZT_ENABLE_CLUSTER
-				if (RR->cluster)
-					RR->cluster->replicateCertificateOfNetworkMembership(com);
-#endif
 			}
 
 			// Check membership after we've read any included COM, since

node/Packet.hpp

@@ -322,8 +322,6 @@
 
 #define ZT_PROTO_VERB_WHOIS__OK__IDX_IDENTITY (ZT_PROTO_VERB_OK_IDX_PAYLOAD)
 
-#define ZT_PROTO_VERB_WHOIS__ERROR__IDX_ZTADDRESS (ZT_PROTO_VERB_ERROR_IDX_PAYLOAD)
-
 #define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_NETWORK_ID (ZT_PROTO_VERB_OK_IDX_PAYLOAD)
 #define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT_LEN (ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_NETWORK_ID + 8)
 #define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT (ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT_LEN + 2)
@@ -599,8 +597,11 @@ public:
 		 * OK response payload:
 		 *   <[...] binary serialized identity>
 		 *
-		 * ERROR response payload:
-		 *   <[5] address>
+		 * If querying a cluster, duplicate OK responses may occasionally occur.
+		 * These should be discarded.
+		 *
+		 * If the address is not found, no response is generated. WHOIS requests
+		 * will time out much like ARP requests and similar do in L2.
 		 */
 		VERB_WHOIS = 4,
 
@@ -785,6 +786,9 @@ public:
 		 * to send multicast but does not have the desired number of recipient
 		 * peers.
 		 *
+		 * More than one OK response can occur if the response is broken up across
+		 * multiple packets or if querying a clustered node.
+		 *
 		 * OK response payload:
 		 *   <[8] 64-bit network ID>
 		 *   <[6] MAC address of multicast group being queried>
@@ -794,16 +798,7 @@ public:
 		 *   <[2] 16-bit number of members enumerated in this packet>
 		 *   <[...] series of 5-byte ZeroTier addresses of enumerated members>
 		 *
-		 * If no endpoints are known, OK and ERROR are both optional. It's okay
-		 * to return nothing in that case since gathering is "lazy."
-		 *
-		 * ERROR response payload:
-		 *   <[8] 64-bit network ID>
-		 *   <[6] MAC address of multicast group being queried>
-		 *   <[4] 32-bit ADI for multicast group being queried>
-		 *
-		 * ERRORs are optional and are only generated if permission is denied,
-		 * certificate of membership is out of date, etc.
+		 * ERROR is not generated; queries that return no response are dropped.
 		 */
 		VERB_MULTICAST_GATHER = 13,
 
@@ -1118,7 +1113,7 @@ public:
 		/* Bad/unsupported protocol version */
 		ERROR_BAD_PROTOCOL_VERSION = 2,
 
-		/* Unknown object queried (e.g. with WHOIS) */
+		/* Unknown object queried */
 		ERROR_OBJ_NOT_FOUND = 3,
 
 		/* HELLO pushed an identity whose address is already claimed */

node/Peer.cpp

@@ -156,14 +156,7 @@ void Peer::received(
 				}
 			}
 
-			if (pathIsConfirmed) {
-
-#ifdef ZT_ENABLE_CLUSTER
-				if ((RR->cluster)&&(verb == Packet::VERB_HELLO))
-					RR->cluster->replicateHavePeer(_id);
-#endif
-
-			} else {
+			if (!pathIsConfirmed) {
 				if (verb == Packet::VERB_OK) {
 
 					Path *slot = (Path *)0;
@@ -186,11 +179,6 @@ void Peer::received(
 						_sortPaths(now);
 					}
 
-#ifdef ZT_ENABLE_CLUSTER
-					if (RR->cluster)
-						RR->cluster->replicateHavePeer(_id);
-#endif
-
 				} else {
 
 					/* If this path is not known, send a HELLO. We don't learn