More major Switch refactor work... still in progress.

4 files changed, 452 insertions, 453 deletions

diff --git a/node/PacketDecoder.cpp b/node/PacketDecoder.cpp
index 558ab63b..79dca1d0 100644
--- a/node/PacketDecoder.cpp
+++ b/node/PacketDecoder.cpp
@@ -29,12 +29,380 @@
 #include "Topology.hpp"
 #include "PacketDecoder.hpp"
 #include "Switch.hpp"
+#include "Peer.hpp"
 
 namespace ZeroTier {
 
 bool PacketDecoder::tryDecode(const RuntimeEnvironment *_r)
 	throw(std::out_of_range,std::runtime_error)
 {
+	Address source(source());
+
+	if ((!encrypted())&&(verb() == Packet::VERB_HELLO)) {
+		// Unencrypted HELLOs are handled here since they are used to
+		// populate our identity cache in the first place. Thus we might get
+		// a HELLO for someone for whom we don't have a Peer record.
+		TRACE("HELLO from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
+		_doHELLO(localPort,fromAddr,packet);
+		return true;
+	}
+
+	SharedPtr<Peer> peer = _r->topology->getPeer(source);
+	if (peer) {
+		uint64_t now = Utils::now();
+		unsigned int latency = 0;
+
+		if (!packet.hmacVerify(peer->macKey())) {
+			TRACE("dropped packet from %s(%s), HMAC authentication failed (size: %u)",source.toString().c_str(),fromAddr.toString().c_str(),packet.size());
+			return true;
+		}
+
+		if (packet.encrypted()) {
+			packet.decrypt(peer->cryptKey());
+		} else {
+			// Unencrypted is tolerated in case we want to run this on
+			// devices where squeezing out cycles matters. HMAC is
+			// what's really important.
+			TRACE("ODD: %s from %s(%s) wasn't encrypted",Packet::verbString(packet.verb()),source.toString().c_str(),fromAddr.toString().c_str());
+		}
+
+		if (!packet.uncompress()) {
+			TRACE("dropped packet from %s(%s), compressed data invalid",source.toString().c_str(),fromAddr.toString().c_str());
+			return true;
+		}
+
+		switch(packet.verb()) {
+			case Packet::VERB_NOP:
+				TRACE("NOP from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
+				break;
+			case Packet::VERB_HELLO:
+				// HELLO is normally handled up top, but this is legal. Pointless, but legal.
+				_doHELLO(localPort,fromAddr,packet);
+				break;
+			case Packet::VERB_ERROR:
+				try {
+#ifdef ZT_TRACE
+					Packet::Verb inReVerb = (Packet::Verb)packet[ZT_PROTO_VERB_ERROR_IDX_IN_RE_VERB];
+					Packet::ErrorCode errorCode = (Packet::ErrorCode)packet[ZT_PROTO_VERB_ERROR_IDX_ERROR_CODE];
+					TRACE("ERROR %s from %s(%s) in-re %s",Packet::errorString(errorCode),source.toString().c_str(),fromAddr.toString().c_str(),Packet::verbString(inReVerb));
+#endif
+					// TODO:
+					// The fact is that the protocol works fine without error handling.
+					// The only error that really needs to be handled here is duplicate
+					// identity collision, which if it comes from a supernode should cause
+					// us to restart and regenerate a new identity.
+				} catch (std::exception &ex) {
+					TRACE("dropped ERROR from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
+				} catch ( ... ) {
+					TRACE("dropped ERROR from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
+				}
+				break;
+			case Packet::VERB_OK:
+				try {
+					Packet::Verb inReVerb = (Packet::Verb)packet[ZT_PROTO_VERB_OK_IDX_IN_RE_VERB];
+					switch(inReVerb) {
+						case Packet::VERB_HELLO:
+							// OK from HELLO permits computation of latency.
+							latency = std::min((unsigned int)(now - packet.at<uint64_t>(ZT_PROTO_VERB_HELLO__OK__IDX_TIMESTAMP)),(unsigned int)0xffff);
+							TRACE("%s(%s): OK(HELLO), latency: %u",source.toString().c_str(),fromAddr.toString().c_str(),latency);
+							break;
+						case Packet::VERB_WHOIS:
+							// Right now we only query supernodes for WHOIS and only accept
+							// OK back from them. If we query other nodes, we'll have to
+							// do something to prevent WHOIS cache poisoning such as
+							// using the packet ID field in the OK packet to match with the
+							// original query. Technically we should be doing this anyway.
+							TRACE("%s(%s): OK(%s)",source.toString().c_str(),fromAddr.toString().c_str(),Packet::verbString(inReVerb));
+							if (_r->topology->isSupernode(source))
+								_r->topology->addPeer(SharedPtr<Peer>(new Peer(_r->identity,Identity(packet,ZT_PROTO_VERB_WHOIS__OK__IDX_IDENTITY))),&Switch::_CBaddPeerFromWhois,this);
+							break;
+						default:
+							TRACE("%s(%s): OK(%s)",source.toString().c_str(),fromAddr.toString().c_str(),Packet::verbString(inReVerb));
+							break;
+					}
+				} catch (std::exception &ex) {
+					TRACE("dropped OK from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
+				} catch ( ... ) {
+					TRACE("dropped OK from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
+				}
+				break;
+			case Packet::VERB_WHOIS:
+				if (packet.payloadLength() == ZT_ADDRESS_LENGTH) {
+					SharedPtr<Peer> p(_r->topology->getPeer(Address(packet.payload())));
+					if (p) {
+						Packet outp(source,_r->identity.address(),Packet::VERB_OK);
+						outp.append((unsigned char)Packet::VERB_WHOIS);
+						outp.append(packet.packetId());
+						p->identity().serialize(outp,false);
+						outp.encrypt(peer->cryptKey());
+						outp.hmacSet(peer->macKey());
+						_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
+						TRACE("sent WHOIS response to %s for %s",source.toString().c_str(),Address(packet.payload()).toString().c_str());
+					} else {
+						Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
+						outp.append((unsigned char)Packet::VERB_WHOIS);
+						outp.append(packet.packetId());
+						outp.append((unsigned char)Packet::ERROR_NOT_FOUND);
+						outp.append(packet.payload(),ZT_ADDRESS_LENGTH);
+						outp.encrypt(peer->cryptKey());
+						outp.hmacSet(peer->macKey());
+						_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
+						TRACE("sent WHOIS ERROR to %s for %s (not found)",source.toString().c_str(),Address(packet.payload()).toString().c_str());
+					}
+				} else {
+					TRACE("dropped WHOIS from %s(%s): missing or invalid address",source.toString().c_str(),fromAddr.toString().c_str());
+				}
+				break;
+			case Packet::VERB_RENDEZVOUS:
+				try {
+					Address with(packet.field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS,ZT_ADDRESS_LENGTH));
+					RendezvousQueueEntry qe;
+					if (_r->topology->getPeer(with)) {
+						unsigned int port = packet.at<uint16_t>(ZT_PROTO_VERB_RENDEZVOUS_IDX_PORT);
+						unsigned int addrlen = packet[ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRLEN];
+						if ((port > 0)&&((addrlen == 4)||(addrlen == 16))) {
+							qe.inaddr.set(packet.field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRESS,addrlen),addrlen,port);
+							qe.fireAtTime = now + ZT_RENDEZVOUS_NAT_T_DELAY; // then send real packet in a few ms
+							qe.localPort = _r->demarc->pick(qe.inaddr);
+							TRACE("RENDEZVOUS from %s says %s might be at %s, starting NAT-t",source.toString().c_str(),with.toString().c_str(),qe.inaddr.toString().c_str());
+							_r->demarc->send(qe.localPort,qe.inaddr,"\0",1,ZT_FIREWALL_OPENER_HOPS); // start with firewall opener
+							{
+								Mutex::Lock _l(_rendezvousQueue_m);
+								_rendezvousQueue[with] = qe;
+							}
+						} else {
+							TRACE("dropped corrupt RENDEZVOUS from %s(%s) (bad address or port)",source.toString().c_str(),fromAddr.toString().c_str());
+						}
+					} else {
+						TRACE("ignored RENDEZVOUS from %s(%s) to meet unknown peer %s",source.toString().c_str(),fromAddr.toString().c_str(),with.toString().c_str());
+					}
+				} catch (std::exception &ex) {
+					TRACE("dropped RENDEZVOUS from %s(%s): %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
+				} catch ( ... ) {
+					TRACE("dropped RENDEZVOUS from %s(%s): unexpected exception",source.toString().c_str(),fromAddr.toString().c_str());
+				}
+				break;
+			case Packet::VERB_FRAME:
+				try {
+					SharedPtr<Network> network(_r->nc->network(packet.at<uint64_t>(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID)));
+					if (network) {
+						if (network->isAllowed(source)) {
+							unsigned int etherType = packet.at<uint16_t>(ZT_PROTO_VERB_FRAME_IDX_ETHERTYPE);
+							if ((etherType != ZT_ETHERTYPE_ARP)&&(etherType != ZT_ETHERTYPE_IPV4)&&(etherType != ZT_ETHERTYPE_IPV6)) {
+								TRACE("dropped FRAME from %s: unsupported ethertype",source.toString().c_str());
+							} else if (packet.size() > ZT_PROTO_VERB_FRAME_IDX_PAYLOAD) {
+								network->tap().put(source.toMAC(),network->tap().mac(),etherType,packet.data() + ZT_PROTO_VERB_FRAME_IDX_PAYLOAD,packet.size() - ZT_PROTO_VERB_FRAME_IDX_PAYLOAD);
+							}
+						} else {
+							TRACE("dropped FRAME from %s(%s): not a member of closed network %llu",source.toString().c_str(),fromAddr.toString().c_str(),network->id());
+						}
+					} else {
+						TRACE("dropped FRAME from %s(%s): network %llu unknown",source.toString().c_str(),fromAddr.toString().c_str(),packet.at<uint64_t>(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID));
+					}
+				} catch (std::exception &ex) {
+					TRACE("dropped FRAME from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
+				} catch ( ... ) {
+					TRACE("dropped FRAME from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
+				}
+				break;
+			case Packet::VERB_MULTICAST_LIKE:
+				try {
+					unsigned int ptr = ZT_PACKET_IDX_PAYLOAD;
+					unsigned int numAccepted = 0;
+
+					// Iterate through 18-byte network,MAC,ADI tuples:
+					while ((ptr + 18) <= packet.size()) {
+						uint64_t nwid = packet.at<uint64_t>(ptr); ptr += 8;
+						SharedPtr<Network> network(_r->nc->network(nwid));
+						if (network) {
+							if (network->isAllowed(source)) {
+								MAC mac(packet.field(ptr,6)); ptr += 6;
+								uint32_t adi = packet.at<uint32_t>(ptr); ptr += 4;
+								TRACE("peer %s likes multicast group %s:%.8lx on network %llu",source.toString().c_str(),mac.toString().c_str(),(unsigned long)adi,nwid);
+								_multicaster.likesMulticastGroup(nwid,MulticastGroup(mac,adi),source,now);
+								++numAccepted;
+							} else {
+								TRACE("ignored MULTICAST_LIKE from %s(%s): not a member of closed network %llu",source.toString().c_str(),fromAddr.toString().c_str(),nwid);
+							}
+						} else {
+							TRACE("ignored MULTICAST_LIKE from %s(%s): network %llu unknown or we are not a member",source.toString().c_str(),fromAddr.toString().c_str(),nwid);
+						}
+					}
+
+					Packet outp(source,_r->identity.address(),Packet::VERB_OK);
+					outp.append((unsigned char)Packet::VERB_MULTICAST_LIKE);
+					outp.append(packet.packetId());
+					outp.append((uint16_t)numAccepted);
+					outp.encrypt(peer->cryptKey());
+					outp.hmacSet(peer->macKey());
+					_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
+				} catch (std::exception &ex) {
+					TRACE("dropped MULTICAST_LIKE from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
+				} catch ( ... ) {
+					TRACE("dropped MULTICAST_LIKE from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
+				}
+				break;
+			case Packet::VERB_MULTICAST_FRAME:
+				try {
+					SharedPtr<Network> network(_r->nc->network(packet.at<uint64_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID)));
+					if (network) {
+						if (network->isAllowed(source)) {
+							if (packet.size() > ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD) {
+								Address originalSubmitterAddress(packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SUBMITTER_ADDRESS,ZT_ADDRESS_LENGTH));
+								MAC fromMac(packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SOURCE_MAC,6));
+								MulticastGroup mg(MAC(packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_DESTINATION_MAC,6)),packet.at<uint32_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ADI));
+								unsigned int hops = packet[ZT_PROTO_VERB_MULTICAST_FRAME_IDX_HOP_COUNT];
+								unsigned int etherType = packet.at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ETHERTYPE);
+								unsigned int datalen = packet.at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD_LENGTH);
+								unsigned int signaturelen = packet.at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SIGNATURE_LENGTH);
+								unsigned char *dataAndSignature = packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD,datalen + signaturelen);
+
+								bool isDuplicate = _multicaster.checkAndUpdateMulticastHistory(fromMac,mg,payload,payloadLen,network->id(),now);
+
+								if (originalSubmitterAddress == _r->identity.address()) {
+									// Technically should not happen, since the original submitter is
+									// excluded from consideration as a propagation recipient.
+									TRACE("dropped boomerang MULTICAST_FRAME received from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
+								} else if ((!isDuplicate)||(_r->topology.isSupernode(_r->identity.address()))) {
+									// If I am a supernode, I will repeatedly propagate duplicates. That's
+									// because supernodes are used to bridge sparse multicast groups. Non-
+									// supernodes will ignore duplicates completely.
+									SharedPtr<Peer> originalSubmitter(_r->topology->getPeer(originalSubmitterAddress));
+									if (!originalSubmitter) {
+										TRACE("requesting WHOIS on original multicast frame submitter %s",originalSubmitterAddress.toString().c_str());
+										_requestWhois(originalSubmitterAddress,packet.packetId());
+										return false;
+									} else if (Multicaster::verifyMulticastPacket(originalSubmitter->identity(),fromMac,mg,etherType,data,datalen,dataAndSignature + datalen,signaturelen)) {
+										if (!isDuplicate)
+											network->tap().put(fromMac,mg.mac(),etherType,payload,payloadLen);
+										_propagateMulticast(network,originalSubmitterAddress,source,packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_BLOOM,ZT_PROTO_VERB_MULTICAST_FRAME_BLOOM_FILTER_SIZE),mg,hops+1,fromMac,etherType,payload,payloadLen);
+									} else {
+										LOG("rejected MULTICAST_FRAME from %s(%s) due to failed signature check (claims original sender %s)",source.toString().c_str(),fromAddr.toString().c_str(),originalSubmitterAddress.toString().c_str());
+									}
+								} else {
+									TRACE("dropped redundant MULTICAST_FRAME from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
+								}
+							} else {
+								TRACE("dropped MULTICAST_FRAME from %s(%s): invalid short packet",source.toString().c_str(),fromAddr.toString().c_str());
+							}
+						} else {
+							TRACE("dropped MULTICAST_FRAME from %s(%s): not a member of closed network %llu",source.toString().c_str(),fromAddr.toString().c_str(),network->id());
+						}
+					} else {
+						TRACE("dropped MULTICAST_FRAME from %s(%s): network %llu unknown or we are not a member",source.toString().c_str(),fromAddr.toString().c_str(),packet.at<uint64_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID));
+					}
+				} catch (std::exception &ex) {
+					TRACE("dropped MULTICAST_FRAME from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
+				} catch ( ... ) {
+					TRACE("dropped MULTICAST_FRAME from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
+				}
+				break;
+			default:
+				// This might be something from a new or old version of the protocol.
+				// Technically it passed HMAC so the packet is still valid, but we
+				// ignore it.
+				TRACE("ignored unrecognized verb %.2x from %s(%s)",(unsigned int)packet.verb(),source.toString().c_str(),fromAddr.toString().c_str());
+				break;
+		}
+
+		// Update peer timestamps and learn new links. This must only ever
+		// be called on an authenticated and technically valid packet, since
+		// we only learn paths to peers over the WAN by hearing directly
+		// from them over those paths. (Or by having them authoritatively
+		// and statically defined, like with supernodes, but that's done
+		// elsewhere.)
+		peer->onReceive(_r,localPort,fromAddr,latency,packet.hops(),packet.verb(),now);
+	} else {
+		_requestWhois(source,packet.packetId());
+		return false;
+	}
+
+	return true;
+}
+
+void PacketDecoder::_doHELLO(Demarc::Port localPort,const InetAddress &fromAddr)
+{
+	Address source(source());
+
+	try {
+		unsigned int protoVersion = packet[ZT_PROTO_VERB_HELLO_IDX_PROTOCOL_VERSION];
+		unsigned int vMajor = packet[ZT_PROTO_VERB_HELLO_IDX_MAJOR_VERSION];
+		unsigned int vMinor = packet[ZT_PROTO_VERB_HELLO_IDX_MINOR_VERSION];
+		unsigned int vRevision = packet.at<uint16_t>(ZT_PROTO_VERB_HELLO_IDX_REVISION);
+		uint64_t timestamp = packet.at<uint64_t>(ZT_PROTO_VERB_HELLO_IDX_TIMESTAMP);
+		Identity id(packet,ZT_PROTO_VERB_HELLO_IDX_IDENTITY);
+
+		SharedPtr<Peer> candidate(new Peer(_r->identity,id));
+		candidate->setPathAddress(fromAddr,false);
+
+		// Initial sniff test
+		if (protoVersion != ZT_PROTO_VERSION) {
+			TRACE("rejected HELLO from %s(%s): invalid protocol version",source.toString().c_str(),fromAddr.toString().c_str());
+			Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
+			outp.append((unsigned char)Packet::VERB_HELLO);
+			outp.append(packet.packetId());
+			outp.append((unsigned char)Packet::ERROR_BAD_PROTOCOL_VERSION);
+			outp.encrypt(candidate->cryptKey());
+			outp.hmacSet(candidate->macKey());
+			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
+			return;
+		}
+		if (id.address().isReserved()) {
+			TRACE("rejected HELLO from %s(%s): identity has reserved address",source.toString().c_str(),fromAddr.toString().c_str());
+			Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
+			outp.append((unsigned char)Packet::VERB_HELLO);
+			outp.append(packet.packetId());
+			outp.append((unsigned char)Packet::ERROR_IDENTITY_INVALID);
+			outp.encrypt(candidate->cryptKey());
+			outp.hmacSet(candidate->macKey());
+			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
+			return;
+		}
+		if (id.address() != source) {
+			TRACE("rejected HELLO from %s(%s): identity is not for sender of packet (HELLO is a self-announcement)",source.toString().c_str(),fromAddr.toString().c_str());
+			Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
+			outp.append((unsigned char)Packet::VERB_HELLO);
+			outp.append(packet.packetId());
+			outp.append((unsigned char)Packet::ERROR_INVALID_REQUEST);
+			outp.encrypt(candidate->cryptKey());
+			outp.hmacSet(candidate->macKey());
+			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
+			return;
+		}
+
+		// Is this a HELLO for a peer we already know? If so just update its
+		// packet receive stats and send an OK.
+		SharedPtr<Peer> existingPeer(_r->topology->getPeer(id.address()));
+		if ((existingPeer)&&(existingPeer->identity() == id)) {
+			existingPeer->onReceive(_r,localPort,fromAddr,0,packet.hops(),Packet::VERB_HELLO,Utils::now());
+
+			Packet outp(source,_r->identity.address(),Packet::VERB_OK);
+			outp.append((unsigned char)Packet::VERB_HELLO);
+			outp.append(packet.packetId());
+			outp.append(timestamp);
+			outp.encrypt(existingPeer->cryptKey());
+			outp.hmacSet(existingPeer->macKey());
+			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
+			return;
+		}
+
+		// Otherwise we call addPeer() and set up a callback to handle the verdict
+		_CBaddPeerFromHello_Data *arg = new _CBaddPeerFromHello_Data;
+		arg->parent = this;
+		arg->source = source;
+		arg->fromAddr = fromAddr;
+		arg->localPort = localPort;
+		arg->vMajor = vMajor;
+		arg->vMinor = vMinor;
+		arg->vRevision = vRevision;
+		arg->helloPacketId = packet.packetId();
+		arg->helloTimestamp = timestamp;
+		_r->topology->addPeer(candidate,&Switch::_CBaddPeerFromHello,arg);
+	} catch (std::exception &ex) {
+		TRACE("dropped HELLO from %s(%s): %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
+	} catch ( ... ) {
+		TRACE("dropped HELLO from %s(%s): unexpected exception",source.toString().c_str(),fromAddr.toString().c_str());
+	}
 }
 
 } // namespace ZeroTier
diff --git a/node/PacketDecoder.hpp b/node/PacketDecoder.hpp
index 09f6e1c4..5f27c56b 100644
--- a/node/PacketDecoder.hpp
+++ b/node/PacketDecoder.hpp
@@ -52,7 +52,7 @@ public:
 	template<unsigned int C2>
 	PacketDecoder(const Buffer<C2> &b,Demarc::Port localPort,const InetAddress &remoteAddress)
  		throw(std::out_of_range) :
- 		Packet(b) :
+ 		Packet(b),
  		_receiveTime(Utils::now()),
  		_localPort(localPort),
  		_remoteAddress(remoteAddress),
@@ -76,6 +76,8 @@ public:
 	inline uint64_t receiveTime() const throw() { return _receiveTime; }
 
 private:
+	void _doHELLO(Demarc::Port localPort,const InetAddress &fromAddr);
+
 	uint64_t _receiveTime;
 	Demarc::Port _localPort;
 	InetAddress _remoteAddress;
diff --git a/node/Switch.cpp b/node/Switch.cpp
index 2984995e..7a1784ac 100644
--- a/node/Switch.cpp
+++ b/node/Switch.cpp
@@ -58,13 +58,14 @@ Switch::~Switch()
 
 void Switch::onRemotePacket(Demarc::Port localPort,const InetAddress &fromAddr,const Buffer<4096> &data)
 {
-	Packet packet;
 	try {
 		if (data.size() > ZT_PROTO_MIN_FRAGMENT_LENGTH) {
-			if (data[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_INDICATOR] == ZT_PACKET_FRAGMENT_INDICATOR) {
+			if (data[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_INDICATOR] == ZT_PACKET_FRAGMENT_INDICATOR)
 				_handleRemotePacketFragment(localPort,fromAddr,data);
-			} else if (data.size() > ZT_PROTO_MIN_PACKET_LENGTH) {
+			else if (data.size() > ZT_PROTO_MIN_PACKET_LENGTH)
 				_handleRemotePacketHead(localPort,fromAddr,data);
+			else {
+				TRACE("dropped runt packet from %s",fromAddr.toString().c_str());
 			}
 		}
 	} catch (std::exception &ex) {
@@ -118,7 +119,7 @@ void Switch::onLocalEthernet(const SharedPtr<Network> &network,const MAC &from,c
 		if (!np)
 			return;
 
-		std::string signature(Multicaster::signMulticastPacket(_r->identity,network->id(),from,mg,etherType,data,len));
+		std::string signature(Multicaster::signMulticastPacket(_r->identity,network->id(),from,mg,etherType,data.data(),data.size()));
 		if (!signature.length()) {
 			TRACE("failure signing multicast message!");
 			return;
@@ -131,12 +132,12 @@ void Switch::onLocalEthernet(const SharedPtr<Network> &network,const MAC &from,c
 		outpTmpl.append(from.data,6);
 		outpTmpl.append(mg.mac().data,6);
 		outpTmpl.append((uint32_t)mg.adi());
-		outpTmpl.append(newBloom.data(),ZT_PROTO_VERB_MULTICAST_FRAME_BLOOM_FILTER_SIZE);
+		outpTmpl.append(newbf.data(),ZT_PROTO_VERB_MULTICAST_FRAME_BLOOM_FILTER_SIZE_BYTES);
 		outpTmpl.append((uint8_t)0); // 0 hops
 		outpTmpl.append((uint16_t)etherType);
-		outpTmpl.append((uint16_t)len);
+		outpTmpl.append((uint16_t)data.size());
 		outpTmpl.append((uint16_t)signature.length());
-		outpTmpl.append(data,len);
+		outpTmpl.append(data.data(),data.size());
 		outpTmpl.append(signature.data(),signature.length());
 		outpTmpl.compress();
 		send(outpTmpl,true);
@@ -168,7 +169,7 @@ void Switch::send(const Packet &packet,bool encrypt)
 	//TRACE("%.16llx %s -> %s (size: %u) (enc: %s)",packet.packetId(),Packet::verbString(packet.verb()),packet.destination().toString().c_str(),packet.size(),(encrypt ? "yes" : "no"));
 	if (!_trySend(packet,encrypt)) {
 		Mutex::Lock _l(_txQueue_m);
-		_txQueue.insert(std::pair< uint64_t,TXQueueEntry >(packet.packetId(),TXQueueEntry(Utils::now(),packet,encrypt)));
+		_txQueue.insert(std::pair< Address,TXQueueEntry >(packet.destination(),TXQueueEntry(Utils::now(),packet,encrypt)));
 	}
 }
 
@@ -311,7 +312,7 @@ unsigned long Switch::doTimerTasks()
 
 	{
 		Mutex::Lock _l(_txQueue_m);
-		for(std::map< uint64_t,TXQueueEntry >::iterator i(_txQueue.begin());i!=_txQueue.end();) {
+		for(std::multimap< Address,TXQueueEntry >::iterator i(_txQueue.begin());i!=_txQueue.end();) {
 			if (_trySend(i->second.packet,i->second.encrypt))
 				_txQueue.erase(i++);
 			else if ((now - i->second.creationTime) > ZT_TRANSMIT_QUEUE_TIMEOUT) {
@@ -320,13 +321,12 @@ unsigned long Switch::doTimerTasks()
 			} else ++i;
 		}
 	}
+
 	{
 		Mutex::Lock _l(_rxQueue_m);
-		for(std::map< uint64_t,RXQueueEntry >::iterator i(_rxQueue.begin());i!=_rxQueue.end();) {
-			if (_tryHandleRemotePacket(i->second.localPort,i->second.fromAddr,i->second.packet))
-				_rxQueue.erase(i++);
-			else if ((now - i->second.creationTime) > ZT_RECEIVE_QUEUE_TIMEOUT) {
-				TRACE("RX from %s timed out waiting for WHOIS",i->second.packet.source().toString().c_str());
+		for(std::multimap< Address,SharedPtr<PacketDecoder> >::iterator i(_rxQueue.begin());i!=_rxQueue.end();) {
+			if ((now - i->second->receiveTime()) > ZT_RECEIVE_QUEUE_TIMEOUT) {
+				TRACE("RX %s -> %s timed out",i->second->source().toString().c_str(),i->second->destination().toString().c_str());
 				_rxQueue.erase(i++);
 			} else ++i;
 		}
@@ -342,7 +342,7 @@ unsigned long Switch::doTimerTasks()
 		}
 	}
 
-	return std::max(nextDelay,(unsigned long)50); // minimum delay
+	return std::max(nextDelay,(unsigned long)10); // minimum delay
 }
 
 void Switch::announceMulticastGroups(const std::map< SharedPtr<Network>,std::set<MulticastGroup> > &allMemberships)
@@ -380,15 +380,16 @@ void Switch::announceMulticastGroups(const std::map< SharedPtr<Network>,std::set
 	}
 }
 
-void Switch::requestWhois(const Address &addr,const SharedPtr<PacketDecoder> &pd)
+void Switch::requestWhois(const Address &addr)
 {
 	TRACE("requesting WHOIS for %s",addr.toString().c_str());
+	{
+		Mutex::Lock _l(_outstandingWhoisRequests_m);
+		std::pair< std::map< Address,WhoisRequest >::iterator,bool > entry(_outstandingWhoisRequests.insert(std::pair<Address,WhoisRequest>(addr,WhoisRequest())));
+		entry.first->second.lastSent = Utils::now();
+		entry.first->second.retries = 0; // reset retry count if entry already existed
+	}
 	_sendWhoisRequest(addr,(const Address *)0,0);
-	Mutex::Lock _l(_outstandingWhoisRequests_m);
-	std::pair< std::map< Address,WhoisRequest >::iterator,bool > entry(_outstandingWhoisRequests.insert(std::pair<Address,WhoisRequest>(addr,WhoisRequest())));
-	entry.first->second.lastSent = Utils::now();
-	entry.first->second.retries = 0; // reset retry count if entry already existed
-	entry.first->second.waitingPackets.insert(pd);
 }
 
 void Switch::_CBaddPeerFromHello(void *arg,const SharedPtr<Peer> &p,Topology::PeerVerifyResult result)
@@ -400,7 +401,7 @@ void Switch::_CBaddPeerFromHello(void *arg,const SharedPtr<Peer> &p,Topology::Pe
 		case Topology::PEER_VERIFY_ACCEPTED_NEW:
 		case Topology::PEER_VERIFY_ACCEPTED_ALREADY_HAVE:
 		case Topology::PEER_VERIFY_ACCEPTED_DISPLACED_INVALID_ADDRESS: {
-			req->parent->_finishWhoisRequest(p); // terminate any outstanding WHOIS too
+			req->parent->_finishWhoisRequest(p);
 
 			Packet outp(req->source,_r->identity.address(),Packet::VERB_OK);
 			outp.append((unsigned char)Packet::VERB_HELLO);
@@ -449,31 +450,31 @@ void Switch::_CBaddPeerFromWhois(void *arg,const SharedPtr<Peer> &p,Topology::Pe
 	}
 }
 
-void Switch::_finishWhoisRequest(
-	const SharedPtr<Peer> &peer)
+void Switch::_finishWhoisRequest(const SharedPtr<Peer> &peer)
 {
-	Mutex::Lock _l(_outstandingWhoisRequests_m);
-	std::map< Address,WhoisRequest >::iterator wr(_outstandingWhoisRequests.find(peer->address()));
-	if (wr != _outstandingWhoisRequests.end()) {
-		for(std::set<uint64_t>::iterator pid(wr->second.waitingPackets.begin());pid!=wr->second.waitingPackets.end();++pid) {
-			{
-				Mutex::Lock _l(_txQueue_m);
-				std::map< uint64_t,TXQueueEntry >::iterator txitem(_txQueue.find(*pid));
-				if (txitem != _txQueue.end()) {
-					if (_trySend(txitem->second.packet,txitem->second.encrypt))
-						_txQueue.erase(txitem);
-				}
-			}
-			{
-				Mutex::Lock _l(_rxQueue_m);
-				std::map< uint64_t,RXQueueEntry >::iterator rxitem(_rxQueue.find(*pid));
-				if (rxitem != _rxQueue.end()) {
-					if (_tryHandleRemotePacket(rxitem->second.localPort,rxitem->second.fromAddr,rxitem->second.packet))
-						_rxQueue.erase(rxitem);
-				}
-			}
+	{
+		Mutex::Lock _l(_outstandingWhoisRequests_m);
+		_outstandingWhoisRequests.erase(peer->address());
+	}
+
+	{
+		Mutex::Lock _l(_rxQueue_m);
+		std::pair< std::multimap< Address,SharedPtr<PacketDecoder> >::iterator,std::multimap< Address,SharedPtr<PacketDecoder> >::iterator > waitingRxQueueItems(_rxQueue.equal_range(peer->address()));
+		for(std::multimap< Address,SharedPtr<PacketDecoder> >::iterator rxi(waitingRxQueueItems.first);rxi!=waitingRxQueueItems.second;) {
+			if (rxi->second->tryDecode(_r))
+				_rxQueue.erase(rxi++);
+			else ++rxi;
+		}
+	}
+
+	{
+		Mutex::Lock _l(_txQueue_m);
+		std::pair< std::multimap< Address,TXQueueEntry >::iterator,std::multimap< Address,TXQueueEntry >::iterator > waitingTxQueueItems(_txQueue.equal_range(peer->address()));
+		for(std::multimap< Address,TXQueueEntry >::iterator txi(waitingTxQueueItems.first);txi!=waitingTxQueueItems.second;) {
+			if (_trySend(txi->second.packet,txi->second.encrypt))
+				_txQueue.erase(txi++);
+			else ++txi;
 		}
-		_outstandingWhoisRequests.erase(wr);
 	}
 }
 
@@ -484,7 +485,6 @@ void Switch::_handleRemotePacketFragment(Demarc::Port localPort,const InetAddres
 	Address destination(fragment.destination());
 	if (destination != _r->identity.address()) {
 		// Fragment is not for us, so try to relay it
-
 		if (fragment.hops() < ZT_RELAY_MAX_HOPS) {
 			fragment.incrementHops();
 
@@ -499,7 +499,6 @@ void Switch::_handleRemotePacketFragment(Demarc::Port localPort,const InetAddres
 		}
 	} else {
 		// Fragment looks like ours
-
 		uint64_t pid = fragment.packetId();
 		unsigned int fno = fragment.fragmentNumber();
 		unsigned int tf = fragment.totalFragments();
@@ -531,53 +530,53 @@ void Switch::_handleRemotePacketFragment(Demarc::Port localPort,const InetAddres
 
 				if (Utils::countBits(dqe->second.haveFragments |= (1 << fno)) == tf) {
 					// We have all fragments -- assemble and process full Packet
-
 					//TRACE("packet %.16llx is complete, assembling and processing...",pid);
-					Packet packet(dqe->second.frag0);
+
+					SharedPtr<PacketDecoder> packet(dqe->second.frag0);
 					for(unsigned int f=1;f<tf;++f)
-						packet.append(dqe->second.frags[f - 1].payload(),dqe->second.frags[f - 1].payloadLength());
+						packet->append(dqe->second.frags[f - 1].payload(),dqe->second.frags[f - 1].payloadLength());
 					_defragQueue.erase(dqe);
 
-					_handleRemotePacket(localPort,fromAddr,packet);
+					if (!packet->tryDecode(_r)) {
+						Mutex::Lock _l(_rxQueue_m);
+						_rxQueue.insert(std::pair< Address,SharedPtr<PacketDecoder> >(destination,packet));
+					}
 				}
 			} // else this is a duplicate fragment, ignore
 		}
 	}
 }
 
-bool Switch::_handleRemotePacketHead(Demarc::Port localPort,const InetAddress &fromAddr,const Buffer<4096> &data)
+void Switch::_handleRemotePacketHead(Demarc::Port localPort,const InetAddress &fromAddr,const Buffer<4096> &data)
 {
-	Packet packet(data);
+	SharedPtr<PacketDecoder> packet(new PacketDecoder(data,localPort,fromAddr));
+	Address destination(packet->destination());
 
-	Address destination(packet.destination());
 	if (destination != _r->identity.address()) {
 		// Packet is not for us, so try to relay it
-
-		if (packet.hops() < ZT_RELAY_MAX_HOPS) {
-			packet.incrementHops();
+		if (packet->hops() < ZT_RELAY_MAX_HOPS) {
+			packet->incrementHops();
 
 			SharedPtr<Peer> relayTo = _r->topology->getPeer(destination);
-			if ((relayTo)&&(relayTo->send(_r,packet.data(),packet.size(),true,Packet::VERB_NOP,Utils::now()))) {
-				// TODO: don't unite immediately, wait until the peers have exchanged a packet or two
-				unite(packet.source(),destination,false); // periodically try to get them to talk directly
+			if ((relayTo)&&(relayTo->send(_r,packet->data(),packet->size(),true,Packet::VERB_NOP,Utils::now()))) {
+				unite(packet->source(),destination,false); // periodically try to get them to talk directly
 			} else {
 				relayTo = _r->topology->getBestSupernode();
 				if (relayTo)
-					relayTo->send(_r,packet.data(),packet.size(),true,Packet::VERB_NOP,Utils::now());
+					relayTo->send(_r,packet->data(),packet->size(),true,Packet::VERB_NOP,Utils::now());
 			}
 		} else {
-			TRACE("dropped relay %s(%s) -> %s, max hops exceeded",packet.source().toString().c_str(),fromAddr.toString().c_str(),destination.toString().c_str());
+			TRACE("dropped relay %s(%s) -> %s, max hops exceeded",packet->source().toString().c_str(),fromAddr.toString().c_str(),destination.toString().c_str());
 		}
-	} else if (packet.fragmented()) {
+	} else if (packet->fragmented()) {
 		// Packet is the head of a fragmented packet series
 
-		uint64_t pid = packet.packetId();
+		uint64_t pid = packet->packetId();
 		Mutex::Lock _l(_defragQueue_m);
 		std::map< uint64_t,DefragQueueEntry >::iterator dqe(_defragQueue.find(pid));
 
 		if (dqe == _defragQueue.end()) {
 			// If we have no other fragments yet, create an entry and save the head
-
 			DefragQueueEntry &dq = _defragQueue[pid];
 			dq.creationTime = Utils::now();
 			dq.frag0 = packet;
@@ -586,398 +585,30 @@ bool Switch::_handleRemotePacketHead(Demarc::Port localPort,const InetAddress &f
 			//TRACE("fragment (0/?) of %.16llx from %s",pid,fromAddr.toString().c_str());
 		} else if (!(dqe->second.haveFragments & 1)) {
 			// If we have other fragments but no head, see if we are complete with the head
-
 			if ((dqe->second.totalFragments)&&(Utils::countBits(dqe->second.haveFragments |= 1) == dqe->second.totalFragments)) {
 				// We have all fragments -- assemble and process full Packet
 
 				//TRACE("packet %.16llx is complete, assembling and processing...",pid);
 				// packet already contains head, so append fragments
 				for(unsigned int f=1;f<dqe->second.totalFragments;++f)
-					packet.append(dqe->second.frags[f - 1].payload(),dqe->second.frags[f - 1].payloadLength());
+					packet->append(dqe->second.frags[f - 1].payload(),dqe->second.frags[f - 1].payloadLength());
 				_defragQueue.erase(dqe);
 
-				_handleRemotePacket(localPort,fromAddr,packet);
+				if (!packet->tryDecode(_r)) {
+					Mutex::Lock _l(_rxQueue_m);
+					_rxQueue.insert(std::pair< Address,SharedPtr<PacketDecoder> >(destination,packet));
+				}
 			} else {
 				// Still waiting on more fragments, so queue the head
-
 				dqe->second.frag0 = packet;
 			}
 		} // else this is a duplicate head, ignore
 	} else {
 		// Packet is unfragmented, so just process it
-		_handleRemotePacket(localPort,fromAddr,packet);
-	}
-}
-
-//////////////////// OBSOLETE
-bool Switch::_tryHandleRemotePacket(Demarc::Port localPort,const InetAddress &fromAddr,Packet &packet)
-{
-
-	Address source(packet.source());
-
-	if ((!packet.encrypted())&&(packet.verb() == Packet::VERB_HELLO)) {
-		// Unencrypted HELLOs are handled here since they are used to
-		// populate our identity cache in the first place. Thus we might get
-		// a HELLO for someone for whom we don't have a Peer record.
-		TRACE("HELLO from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
-		_doHELLO(localPort,fromAddr,packet);
-		return true;
-	}
-
-	SharedPtr<Peer> peer = _r->topology->getPeer(source);
-	if (peer) {
-		uint64_t now = Utils::now();
-		unsigned int latency = 0;
-
-		if (!packet.hmacVerify(peer->macKey())) {
-			TRACE("dropped packet from %s(%s), HMAC authentication failed (size: %u)",source.toString().c_str(),fromAddr.toString().c_str(),packet.size());
-			return true;
-		}
-
-		if (packet.encrypted()) {
-			packet.decrypt(peer->cryptKey());
-		} else {
-			// Unencrypted is tolerated in case we want to run this on
-			// devices where squeezing out cycles matters. HMAC is
-			// what's really important.
-			TRACE("ODD: %s from %s(%s) wasn't encrypted",Packet::verbString(packet.verb()),source.toString().c_str(),fromAddr.toString().c_str());
-		}
-
-		if (!packet.uncompress()) {
-			TRACE("dropped packet from %s(%s), compressed data invalid",source.toString().c_str(),fromAddr.toString().c_str());
-			return true;
+		if (!packet->tryDecode(_r)) {
+			Mutex::Lock _l(_rxQueue_m);
+			_rxQueue.insert(std::pair< Address,SharedPtr<PacketDecoder> >(destination,packet));
 		}
-
-		switch(packet.verb()) {
-			case Packet::VERB_NOP:
-				TRACE("NOP from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
-				break;
-			case Packet::VERB_HELLO:
-				// HELLO is normally handled up top, but this is legal. Pointless, but legal.
-				_doHELLO(localPort,fromAddr,packet);
-				break;
-			case Packet::VERB_ERROR:
-				try {
-#ifdef ZT_TRACE
-					Packet::Verb inReVerb = (Packet::Verb)packet[ZT_PROTO_VERB_ERROR_IDX_IN_RE_VERB];
-					Packet::ErrorCode errorCode = (Packet::ErrorCode)packet[ZT_PROTO_VERB_ERROR_IDX_ERROR_CODE];
-					TRACE("ERROR %s from %s(%s) in-re %s",Packet::errorString(errorCode),source.toString().c_str(),fromAddr.toString().c_str(),Packet::verbString(inReVerb));
-#endif
-					// TODO:
-					// The fact is that the protocol works fine without error handling.
-					// The only error that really needs to be handled here is duplicate
-					// identity collision, which if it comes from a supernode should cause
-					// us to restart and regenerate a new identity.
-				} catch (std::exception &ex) {
-					TRACE("dropped ERROR from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
-				} catch ( ... ) {
-					TRACE("dropped ERROR from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
-				}
-				break;
-			case Packet::VERB_OK:
-				try {
-					Packet::Verb inReVerb = (Packet::Verb)packet[ZT_PROTO_VERB_OK_IDX_IN_RE_VERB];
-					switch(inReVerb) {
-						case Packet::VERB_HELLO:
-							// OK from HELLO permits computation of latency.
-							latency = std::min((unsigned int)(now - packet.at<uint64_t>(ZT_PROTO_VERB_HELLO__OK__IDX_TIMESTAMP)),(unsigned int)0xffff);
-							TRACE("%s(%s): OK(HELLO), latency: %u",source.toString().c_str(),fromAddr.toString().c_str(),latency);
-							break;
-						case Packet::VERB_WHOIS:
-							// Right now we only query supernodes for WHOIS and only accept
-							// OK back from them. If we query other nodes, we'll have to
-							// do something to prevent WHOIS cache poisoning such as
-							// using the packet ID field in the OK packet to match with the
-							// original query. Technically we should be doing this anyway.
-							TRACE("%s(%s): OK(%s)",source.toString().c_str(),fromAddr.toString().c_str(),Packet::verbString(inReVerb));
-							if (_r->topology->isSupernode(source))
-								_r->topology->addPeer(SharedPtr<Peer>(new Peer(_r->identity,Identity(packet,ZT_PROTO_VERB_WHOIS__OK__IDX_IDENTITY))),&Switch::_CBaddPeerFromWhois,this);
-							break;
-						default:
-							TRACE("%s(%s): OK(%s)",source.toString().c_str(),fromAddr.toString().c_str(),Packet::verbString(inReVerb));
-							break;
-					}
-				} catch (std::exception &ex) {
-					TRACE("dropped OK from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
-				} catch ( ... ) {
-					TRACE("dropped OK from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
-				}
-				break;
-			case Packet::VERB_WHOIS:
-				if (packet.payloadLength() == ZT_ADDRESS_LENGTH) {
-					SharedPtr<Peer> p(_r->topology->getPeer(Address(packet.payload())));
-					if (p) {
-						Packet outp(source,_r->identity.address(),Packet::VERB_OK);
-						outp.append((unsigned char)Packet::VERB_WHOIS);
-						outp.append(packet.packetId());
-						p->identity().serialize(outp,false);
-						outp.encrypt(peer->cryptKey());
-						outp.hmacSet(peer->macKey());
-						_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
-						TRACE("sent WHOIS response to %s for %s",source.toString().c_str(),Address(packet.payload()).toString().c_str());
-					} else {
-						Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
-						outp.append((unsigned char)Packet::VERB_WHOIS);
-						outp.append(packet.packetId());
-						outp.append((unsigned char)Packet::ERROR_NOT_FOUND);
-						outp.append(packet.payload(),ZT_ADDRESS_LENGTH);
-						outp.encrypt(peer->cryptKey());
-						outp.hmacSet(peer->macKey());
-						_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
-						TRACE("sent WHOIS ERROR to %s for %s (not found)",source.toString().c_str(),Address(packet.payload()).toString().c_str());
-					}
-				} else {
-					TRACE("dropped WHOIS from %s(%s): missing or invalid address",source.toString().c_str(),fromAddr.toString().c_str());
-				}
-				break;
-			case Packet::VERB_RENDEZVOUS:
-				try {
-					Address with(packet.field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS,ZT_ADDRESS_LENGTH));
-					RendezvousQueueEntry qe;
-					if (_r->topology->getPeer(with)) {
-						unsigned int port = packet.at<uint16_t>(ZT_PROTO_VERB_RENDEZVOUS_IDX_PORT);
-						unsigned int addrlen = packet[ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRLEN];
-						if ((port > 0)&&((addrlen == 4)||(addrlen == 16))) {
-							qe.inaddr.set(packet.field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRESS,addrlen),addrlen,port);
-							qe.fireAtTime = now + ZT_RENDEZVOUS_NAT_T_DELAY; // then send real packet in a few ms
-							qe.localPort = _r->demarc->pick(qe.inaddr);
-							TRACE("RENDEZVOUS from %s says %s might be at %s, starting NAT-t",source.toString().c_str(),with.toString().c_str(),qe.inaddr.toString().c_str());
-							_r->demarc->send(qe.localPort,qe.inaddr,"\0",1,ZT_FIREWALL_OPENER_HOPS); // start with firewall opener
-							{
-								Mutex::Lock _l(_rendezvousQueue_m);
-								_rendezvousQueue[with] = qe;
-							}
-						} else {
-							TRACE("dropped corrupt RENDEZVOUS from %s(%s) (bad address or port)",source.toString().c_str(),fromAddr.toString().c_str());
-						}
-					} else {
-						TRACE("ignored RENDEZVOUS from %s(%s) to meet unknown peer %s",source.toString().c_str(),fromAddr.toString().c_str(),with.toString().c_str());
-					}
-				} catch (std::exception &ex) {
-					TRACE("dropped RENDEZVOUS from %s(%s): %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
-				} catch ( ... ) {
-					TRACE("dropped RENDEZVOUS from %s(%s): unexpected exception",source.toString().c_str(),fromAddr.toString().c_str());
-				}
-				break;
-			case Packet::VERB_FRAME:
-				try {
-					SharedPtr<Network> network(_r->nc->network(packet.at<uint64_t>(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID)));
-					if (network) {
-						if (network->isAllowed(source)) {
-							unsigned int etherType = packet.at<uint16_t>(ZT_PROTO_VERB_FRAME_IDX_ETHERTYPE);
-							if ((etherType != ZT_ETHERTYPE_ARP)&&(etherType != ZT_ETHERTYPE_IPV4)&&(etherType != ZT_ETHERTYPE_IPV6)) {
-								TRACE("dropped FRAME from %s: unsupported ethertype",source.toString().c_str());
-							} else if (packet.size() > ZT_PROTO_VERB_FRAME_IDX_PAYLOAD) {
-								network->tap().put(source.toMAC(),network->tap().mac(),etherType,packet.data() + ZT_PROTO_VERB_FRAME_IDX_PAYLOAD,packet.size() - ZT_PROTO_VERB_FRAME_IDX_PAYLOAD);
-							}
-						} else {
-							TRACE("dropped FRAME from %s(%s): not a member of closed network %llu",source.toString().c_str(),fromAddr.toString().c_str(),network->id());
-						}
-					} else {
-						TRACE("dropped FRAME from %s(%s): network %llu unknown",source.toString().c_str(),fromAddr.toString().c_str(),packet.at<uint64_t>(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID));
-					}
-				} catch (std::exception &ex) {
-					TRACE("dropped FRAME from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
-				} catch ( ... ) {
-					TRACE("dropped FRAME from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
-				}
-				break;
-			case Packet::VERB_MULTICAST_LIKE:
-				try {
-					unsigned int ptr = ZT_PACKET_IDX_PAYLOAD;
-					unsigned int numAccepted = 0;
-
-					// Iterate through 18-byte network,MAC,ADI tuples:
-					while ((ptr + 18) <= packet.size()) {
-						uint64_t nwid = packet.at<uint64_t>(ptr); ptr += 8;
-						SharedPtr<Network> network(_r->nc->network(nwid));
-						if (network) {
-							if (network->isAllowed(source)) {
-								MAC mac(packet.field(ptr,6)); ptr += 6;
-								uint32_t adi = packet.at<uint32_t>(ptr); ptr += 4;
-								TRACE("peer %s likes multicast group %s:%.8lx on network %llu",source.toString().c_str(),mac.toString().c_str(),(unsigned long)adi,nwid);
-								_multicaster.likesMulticastGroup(nwid,MulticastGroup(mac,adi),source,now);
-								++numAccepted;
-							} else {
-								TRACE("ignored MULTICAST_LIKE from %s(%s): not a member of closed network %llu",source.toString().c_str(),fromAddr.toString().c_str(),nwid);
-							}
-						} else {
-							TRACE("ignored MULTICAST_LIKE from %s(%s): network %llu unknown or we are not a member",source.toString().c_str(),fromAddr.toString().c_str(),nwid);
-						}
-					}
-
-					Packet outp(source,_r->identity.address(),Packet::VERB_OK);
-					outp.append((unsigned char)Packet::VERB_MULTICAST_LIKE);
-					outp.append(packet.packetId());
-					outp.append((uint16_t)numAccepted);
-					outp.encrypt(peer->cryptKey());
-					outp.hmacSet(peer->macKey());
-					_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
-				} catch (std::exception &ex) {
-					TRACE("dropped MULTICAST_LIKE from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
-				} catch ( ... ) {
-					TRACE("dropped MULTICAST_LIKE from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
-				}
-				break;
-			case Packet::VERB_MULTICAST_FRAME:
-				try {
-					SharedPtr<Network> network(_r->nc->network(packet.at<uint64_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID)));
-					if (network) {
-						if (network->isAllowed(source)) {
-							if (packet.size() > ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD) {
-								Address originalSubmitterAddress(packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SUBMITTER_ADDRESS,ZT_ADDRESS_LENGTH));
-								MAC fromMac(packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SOURCE_MAC,6));
-								MulticastGroup mg(MAC(packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_DESTINATION_MAC,6)),packet.at<uint32_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ADI));
-								unsigned int hops = packet[ZT_PROTO_VERB_MULTICAST_FRAME_IDX_HOP_COUNT];
-								unsigned int etherType = packet.at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ETHERTYPE);
-								unsigned int datalen = packet.at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD_LENGTH);
-								unsigned int signaturelen = packet.at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SIGNATURE_LENGTH);
-								unsigned char *dataAndSignature = packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD,datalen + signaturelen);
-
-								bool isDuplicate = _multicaster.checkAndUpdateMulticastHistory(fromMac,mg,payload,payloadLen,network->id(),now);
-
-								if (originalSubmitterAddress == _r->identity.address()) {
-									// Technically should not happen, since the original submitter is
-									// excluded from consideration as a propagation recipient.
-									TRACE("dropped boomerang MULTICAST_FRAME received from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
-								} else if ((!isDuplicate)||(_r->topology.isSupernode(_r->identity.address()))) {
-									// If I am a supernode, I will repeatedly propagate duplicates. That's
-									// because supernodes are used to bridge sparse multicast groups. Non-
-									// supernodes will ignore duplicates completely.
-									SharedPtr<Peer> originalSubmitter(_r->topology->getPeer(originalSubmitterAddress));
-									if (!originalSubmitter) {
-										TRACE("requesting WHOIS on original multicast frame submitter %s",originalSubmitterAddress.toString().c_str());
-										_requestWhois(originalSubmitterAddress,packet.packetId());
-										return false;
-									} else if (Multicaster::verifyMulticastPacket(originalSubmitter->identity(),fromMac,mg,etherType,data,datalen,dataAndSignature + datalen,signaturelen)) {
-										if (!isDuplicate)
-											network->tap().put(fromMac,mg.mac(),etherType,payload,payloadLen);
-										_propagateMulticast(network,originalSubmitterAddress,source,packet.field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_BLOOM,ZT_PROTO_VERB_MULTICAST_FRAME_BLOOM_FILTER_SIZE),mg,hops+1,fromMac,etherType,payload,payloadLen);
-									} else {
-										LOG("rejected MULTICAST_FRAME from %s(%s) due to failed signature check (claims original sender %s)",source.toString().c_str(),fromAddr.toString().c_str(),originalSubmitterAddress.toString().c_str());
-									}
-								} else {
-									TRACE("dropped redundant MULTICAST_FRAME from %s(%s)",source.toString().c_str(),fromAddr.toString().c_str());
-								}
-							} else {
-								TRACE("dropped MULTICAST_FRAME from %s(%s): invalid short packet",source.toString().c_str(),fromAddr.toString().c_str());
-							}
-						} else {
-							TRACE("dropped MULTICAST_FRAME from %s(%s): not a member of closed network %llu",source.toString().c_str(),fromAddr.toString().c_str(),network->id());
-						}
-					} else {
-						TRACE("dropped MULTICAST_FRAME from %s(%s): network %llu unknown or we are not a member",source.toString().c_str(),fromAddr.toString().c_str(),packet.at<uint64_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID));
-					}
-				} catch (std::exception &ex) {
-					TRACE("dropped MULTICAST_FRAME from %s(%s): unexpected exception: %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
-				} catch ( ... ) {
-					TRACE("dropped MULTICAST_FRAME from %s(%s): unexpected exception: (unknown)",source.toString().c_str(),fromAddr.toString().c_str());
-				}
-				break;
-			default:
-				// This might be something from a new or old version of the protocol.
-				// Technically it passed HMAC so the packet is still valid, but we
-				// ignore it.
-				TRACE("ignored unrecognized verb %.2x from %s(%s)",(unsigned int)packet.verb(),source.toString().c_str(),fromAddr.toString().c_str());
-				break;
-		}
-
-		// Update peer timestamps and learn new links. This must only ever
-		// be called on an authenticated and technically valid packet, since
-		// we only learn paths to peers over the WAN by hearing directly
-		// from them over those paths. (Or by having them authoritatively
-		// and statically defined, like with supernodes, but that's done
-		// elsewhere.)
-		peer->onReceive(_r,localPort,fromAddr,latency,packet.hops(),packet.verb(),now);
-	} else {
-		_requestWhois(source,packet.packetId());
-		return false;
-	}
-
-	return true;
-}
-
-void Switch::_doHELLO(Demarc::Port localPort,const InetAddress &fromAddr,Packet &packet)
-{
-	Address source(packet.source());
-	try {
-		unsigned int protoVersion = packet[ZT_PROTO_VERB_HELLO_IDX_PROTOCOL_VERSION];
-		unsigned int vMajor = packet[ZT_PROTO_VERB_HELLO_IDX_MAJOR_VERSION];
-		unsigned int vMinor = packet[ZT_PROTO_VERB_HELLO_IDX_MINOR_VERSION];
-		unsigned int vRevision = packet.at<uint16_t>(ZT_PROTO_VERB_HELLO_IDX_REVISION);
-		uint64_t timestamp = packet.at<uint64_t>(ZT_PROTO_VERB_HELLO_IDX_TIMESTAMP);
-		Identity id(packet,ZT_PROTO_VERB_HELLO_IDX_IDENTITY);
-
-		SharedPtr<Peer> candidate(new Peer(_r->identity,id));
-		candidate->setPathAddress(fromAddr,false);
-
-		// Initial sniff test
-		if (protoVersion != ZT_PROTO_VERSION) {
-			TRACE("rejected HELLO from %s(%s): invalid protocol version",source.toString().c_str(),fromAddr.toString().c_str());
-			Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
-			outp.append((unsigned char)Packet::VERB_HELLO);
-			outp.append(packet.packetId());
-			outp.append((unsigned char)Packet::ERROR_BAD_PROTOCOL_VERSION);
-			outp.encrypt(candidate->cryptKey());
-			outp.hmacSet(candidate->macKey());
-			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
-			return;
-		}
-		if (id.address().isReserved()) {
-			TRACE("rejected HELLO from %s(%s): identity has reserved address",source.toString().c_str(),fromAddr.toString().c_str());
-			Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
-			outp.append((unsigned char)Packet::VERB_HELLO);
-			outp.append(packet.packetId());
-			outp.append((unsigned char)Packet::ERROR_IDENTITY_INVALID);
-			outp.encrypt(candidate->cryptKey());
-			outp.hmacSet(candidate->macKey());
-			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
-			return;
-		}
-		if (id.address() != source) {
-			TRACE("rejected HELLO from %s(%s): identity is not for sender of packet (HELLO is a self-announcement)",source.toString().c_str(),fromAddr.toString().c_str());
-			Packet outp(source,_r->identity.address(),Packet::VERB_ERROR);
-			outp.append((unsigned char)Packet::VERB_HELLO);
-			outp.append(packet.packetId());
-			outp.append((unsigned char)Packet::ERROR_INVALID_REQUEST);
-			outp.encrypt(candidate->cryptKey());
-			outp.hmacSet(candidate->macKey());
-			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
-			return;
-		}
-
-		// Is this a HELLO for a peer we already know? If so just update its
-		// packet receive stats and send an OK.
-		SharedPtr<Peer> existingPeer(_r->topology->getPeer(id.address()));
-		if ((existingPeer)&&(existingPeer->identity() == id)) {
-			existingPeer->onReceive(_r,localPort,fromAddr,0,packet.hops(),Packet::VERB_HELLO,Utils::now());
-
-			Packet outp(source,_r->identity.address(),Packet::VERB_OK);
-			outp.append((unsigned char)Packet::VERB_HELLO);
-			outp.append(packet.packetId());
-			outp.append(timestamp);
-			outp.encrypt(existingPeer->cryptKey());
-			outp.hmacSet(existingPeer->macKey());
-			_r->demarc->send(localPort,fromAddr,outp.data(),outp.size(),-1);
-			return;
-		}
-
-		// Otherwise we call addPeer() and set up a callback to handle the verdict
-		_CBaddPeerFromHello_Data *arg = new _CBaddPeerFromHello_Data;
-		arg->parent = this;
-		arg->source = source;
-		arg->fromAddr = fromAddr;
-		arg->localPort = localPort;
-		arg->vMajor = vMajor;
-		arg->vMinor = vMinor;
-		arg->vRevision = vRevision;
-		arg->helloPacketId = packet.packetId();
-		arg->helloTimestamp = timestamp;
-		_r->topology->addPeer(candidate,&Switch::_CBaddPeerFromHello,arg);
-	} catch (std::exception &ex) {
-		TRACE("dropped HELLO from %s(%s): %s",source.toString().c_str(),fromAddr.toString().c_str(),ex.what());
-	} catch ( ... ) {
-		TRACE("dropped HELLO from %s(%s): unexpected exception",source.toString().c_str(),fromAddr.toString().c_str());
 	}
 }
 
@@ -998,6 +629,7 @@ Address Switch::_sendWhoisRequest(const Address &addr,const Address *peersAlread
 bool Switch::_trySend(const Packet &packet,bool encrypt)
 {
 	SharedPtr<Peer> peer(_r->topology->getPeer(packet.destination()));
+
 	if (peer) {
 		uint64_t now = Utils::now();
 
@@ -1050,7 +682,7 @@ bool Switch::_trySend(const Packet &packet,bool encrypt)
 		return false;
 	}
 
-	_requestWhois(packet.destination(),packet.packetId());
+	requestWhois(packet.destination());
 	return false;
 }
 
diff --git a/node/Switch.hpp b/node/Switch.hpp
index d5ee8211..f6abee15 100644
--- a/node/Switch.hpp
+++ b/node/Switch.hpp
@@ -45,6 +45,7 @@
 #include "SharedPtr.hpp"
 #include "Demarc.hpp"
 #include "Multicaster.hpp"
+#include "PacketDecoder.hpp"
 
 namespace ZeroTier {
 
@@ -154,9 +155,8 @@ public:
 	 * Request WHOIS on a given address
 	 *
 	 * @param addr Address to look up
-	 * @param pd Packet decoder to link to request or NULL for none
 	 */
-	void requestWhois(const Address &addr,const SharedPtr<PacketDecoder> &pd);
+	void requestWhois(const Address &addr);
 
 private:
 	struct _CBaddPeerFromHello_Data
@@ -192,11 +192,6 @@ private:
 		const InetAddress &fromAddr,
 		const Buffer<4096> &data);
 
-	void _doHELLO(
-		Demarc::Port localPort,
-		const InetAddress &fromAddr,
-		Packet &packet);
-
 	Address _sendWhoisRequest(
 		const Address &addr,
 		const Address *peersAlreadyConsulted,
@@ -214,11 +209,13 @@ private:
 		uint64_t lastSent;
 		Address peersConsulted[ZT_MAX_WHOIS_RETRIES]; // by retry
 		unsigned int retries; // 0..ZT_MAX_WHOIS_RETRIES
-		std::set< SharedPtr<PacketDecoder> > waitingPackets;
 	};
 	std::map< Address,WhoisRequest > _outstandingWhoisRequests;
 	Mutex _outstandingWhoisRequests_m;
 
+	std::multimap< Address,SharedPtr<PacketDecoder> > _rxQueue;
+	Mutex _rxQueue_m;
+
 	struct TXQueueEntry
 	{
 		TXQueueEntry() {}
@@ -231,13 +228,13 @@ private:
 		Packet packet; // unencrypted/untagged for TX queue
 		bool encrypt;
 	};
-	std::map< uint64_t,TXQueueEntry > _txQueue;
+	std::multimap< Address,TXQueueEntry > _txQueue;
 	Mutex _txQueue_m;
 
 	struct DefragQueueEntry
 	{
 		uint64_t creationTime;
-		Packet frag0;
+		SharedPtr<PacketDecoder> frag0;
 		Packet::Fragment frags[ZT_MAX_PACKET_FRAGMENTS - 1];
 		unsigned int totalFragments; // 0 if only frag0 received, waiting for frags
 		uint32_t haveFragments; // bit mask, LSB to MSB