Clean up a hostinfo to reduce memory usage (#955)

handshake_manager.go

@@ -46,8 +46,8 @@ type HandshakeManager struct {
 	// Mutex for interacting with the vpnIps and indexes maps
 	sync.RWMutex
 
-	vpnIps  map[iputil.VpnIp]*HostInfo
-	indexes map[uint32]*HostInfo
+	vpnIps  map[iputil.VpnIp]*HandshakeHostInfo
+	indexes map[uint32]*HandshakeHostInfo
 
 	mainHostMap            *HostMap
 	lightHouse             *LightHouse
@@ -64,10 +64,47 @@ type HandshakeManager struct {
 	trigger chan iputil.VpnIp
 }
 
+type HandshakeHostInfo struct {
+	sync.Mutex
+
+	startTime   time.Time       // Time that we first started trying with this handshake
+	ready       bool            // Is the handshake ready
+	counter     int             // How many attempts have we made so far
+	lastRemotes []*udp.Addr     // Remotes that we sent to during the previous attempt
+	packetStore []*cachedPacket // A set of packets to be transmitted once the handshake completes
+
+	hostinfo *HostInfo
+}
+
+func (hh *HandshakeHostInfo) cachePacket(l *logrus.Logger, t header.MessageType, st header.MessageSubType, packet []byte, f packetCallback, m *cachedPacketMetrics) {
+	if len(hh.packetStore) < 100 {
+		tempPacket := make([]byte, len(packet))
+		copy(tempPacket, packet)
+
+		hh.packetStore = append(hh.packetStore, &cachedPacket{t, st, f, tempPacket})
+		if l.Level >= logrus.DebugLevel {
+			hh.hostinfo.logger(l).
+				WithField("length", len(hh.packetStore)).
+				WithField("stored", true).
+				Debugf("Packet store")
+		}
+
+	} else {
+		m.dropped.Inc(1)
+
+		if l.Level >= logrus.DebugLevel {
+			hh.hostinfo.logger(l).
+				WithField("length", len(hh.packetStore)).
+				WithField("stored", false).
+				Debugf("Packet store")
+		}
+	}
+}
+
 func NewHandshakeManager(l *logrus.Logger, mainHostMap *HostMap, lightHouse *LightHouse, outside udp.Conn, config HandshakeConfig) *HandshakeManager {
 	return &HandshakeManager{
-		vpnIps:                 map[iputil.VpnIp]*HostInfo{},
-		indexes:                map[uint32]*HostInfo{},
+		vpnIps:                 map[iputil.VpnIp]*HandshakeHostInfo{},
+		indexes:                map[uint32]*HandshakeHostInfo{},
 		mainHostMap:            mainHostMap,
 		lightHouse:             lightHouse,
 		outside:                outside,
@@ -97,6 +134,31 @@ func (c *HandshakeManager) Run(ctx context.Context) {
 	}
 }
 
+func (hm *HandshakeManager) HandleIncoming(addr *udp.Addr, via *ViaSender, packet []byte, h *header.H) {
+	// First remote allow list check before we know the vpnIp
+	if addr != nil {
+		if !hm.lightHouse.GetRemoteAllowList().AllowUnknownVpnIp(addr.IP) {
+			hm.l.WithField("udpAddr", addr).Debug("lighthouse.remote_allow_list denied incoming handshake")
+			return
+		}
+	}
+
+	switch h.Subtype {
+	case header.HandshakeIXPSK0:
+		switch h.MessageCounter {
+		case 1:
+			ixHandshakeStage1(hm.f, addr, via, packet, h)
+
+		case 2:
+			newHostinfo := hm.queryIndex(h.RemoteIndex)
+			tearDown := ixHandshakeStage2(hm.f, addr, via, newHostinfo, packet, h)
+			if tearDown && newHostinfo != nil {
+				hm.DeleteHostInfo(newHostinfo.hostinfo)
+			}
+		}
+	}
+}
+
 func (c *HandshakeManager) NextOutboundHandshakeTimerTick(now time.Time) {
 	c.OutboundHandshakeTimer.Advance(now)
 	for {
@@ -108,41 +170,35 @@ func (c *HandshakeManager) NextOutboundHandshakeTimerTick(now time.Time) {
 	}
 }
 
-func (c *HandshakeManager) handleOutbound(vpnIp iputil.VpnIp, lighthouseTriggered bool) {
-	hostinfo := c.QueryVpnIp(vpnIp)
-	if hostinfo == nil {
-		return
-	}
-	hostinfo.Lock()
-	defer hostinfo.Unlock()
-
-	// We may have raced to completion but now that we have a lock we should ensure we have not yet completed.
-	if hostinfo.HandshakeComplete {
-		// Ensure we don't exist in the pending hostmap anymore since we have completed
-		c.DeleteHostInfo(hostinfo)
+func (hm *HandshakeManager) handleOutbound(vpnIp iputil.VpnIp, lighthouseTriggered bool) {
+	hh := hm.queryVpnIp(vpnIp)
+	if hh == nil {
 		return
 	}
+	hh.Lock()
+	defer hh.Unlock()
 
+	hostinfo := hh.hostinfo
 	// If we are out of time, clean up
-	if hostinfo.HandshakeCounter >= c.config.retries {
-		hostinfo.logger(c.l).WithField("udpAddrs", hostinfo.remotes.CopyAddrs(c.mainHostMap.preferredRanges)).
-			WithField("initiatorIndex", hostinfo.localIndexId).
-			WithField("remoteIndex", hostinfo.remoteIndexId).
+	if hh.counter >= hm.config.retries {
+		hh.hostinfo.logger(hm.l).WithField("udpAddrs", hh.hostinfo.remotes.CopyAddrs(hm.mainHostMap.preferredRanges)).
+			WithField("initiatorIndex", hh.hostinfo.localIndexId).
+			WithField("remoteIndex", hh.hostinfo.remoteIndexId).
 			WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
-			WithField("durationNs", time.Since(hostinfo.handshakeStart).Nanoseconds()).
+			WithField("durationNs", time.Since(hh.startTime).Nanoseconds()).
 			Info("Handshake timed out")
-		c.metricTimedOut.Inc(1)
-		c.DeleteHostInfo(hostinfo)
+		hm.metricTimedOut.Inc(1)
+		hm.DeleteHostInfo(hostinfo)
 		return
 	}
 
 	// Increment the counter to increase our delay, linear backoff
-	hostinfo.HandshakeCounter++
+	hh.counter++
 
 	// Check if we have a handshake packet to transmit yet
-	if !hostinfo.HandshakeReady {
-		if !ixHandshakeStage0(c.f, hostinfo) {
-			c.OutboundHandshakeTimer.Add(vpnIp, c.config.tryInterval*time.Duration(hostinfo.HandshakeCounter))
+	if !hh.ready {
+		if !ixHandshakeStage0(hm.f, hh) {
+			hm.OutboundHandshakeTimer.Add(vpnIp, hm.config.tryInterval*time.Duration(hh.counter))
 			return
 		}
 	}
@@ -152,11 +208,11 @@ func (c *HandshakeManager) handleOutbound(vpnIp iputil.VpnIp, lighthouseTriggere
 	// NB ^ This comment doesn't jive. It's how the thing gets initialized.
 	// It's the common path. Should it update every time, in case a future LH query/queries give us more info?
 	if hostinfo.remotes == nil {
-		hostinfo.remotes = c.lightHouse.QueryCache(vpnIp)
+		hostinfo.remotes = hm.lightHouse.QueryCache(vpnIp)
 	}
 
-	remotes := hostinfo.remotes.CopyAddrs(c.mainHostMap.preferredRanges)
-	remotesHaveChanged := !udp.AddrSlice(remotes).Equal(hostinfo.HandshakeLastRemotes)
+	remotes := hostinfo.remotes.CopyAddrs(hm.mainHostMap.preferredRanges)
+	remotesHaveChanged := !udp.AddrSlice(remotes).Equal(hh.lastRemotes)
 
 	// We only care about a lighthouse trigger if we have new remotes to send to.
 	// This is a very specific optimization for a fast lighthouse reply.
@@ -165,25 +221,25 @@ func (c *HandshakeManager) handleOutbound(vpnIp iputil.VpnIp, lighthouseTriggere
 		return
 	}
 
-	hostinfo.HandshakeLastRemotes = remotes
+	hh.lastRemotes = remotes
 
 	// TODO: this will generate a load of queries for hosts with only 1 ip
 	// (such as ones registered to the lighthouse with only a private IP)
 	// So we only do it one time after attempting 5 handshakes already.
-	if len(remotes) <= 1 && hostinfo.HandshakeCounter == 5 {
+	if len(remotes) <= 1 && hh.counter == 5 {
 		// If we only have 1 remote it is highly likely our query raced with the other host registered within the lighthouse
 		// Our vpnIp here has a tunnel with a lighthouse but has yet to send a host update packet there so we only know about
 		// the learned public ip for them. Query again to short circuit the promotion counter
-		c.lightHouse.QueryServer(vpnIp, c.f)
+		hm.lightHouse.QueryServer(vpnIp, hm.f)
 	}
 
 	// Send the handshake to all known ips, stage 2 takes care of assigning the hostinfo.remote based on the first to reply
 	var sentTo []*udp.Addr
-	hostinfo.remotes.ForEach(c.mainHostMap.preferredRanges, func(addr *udp.Addr, _ bool) {
-		c.messageMetrics.Tx(header.Handshake, header.MessageSubType(hostinfo.HandshakePacket[0][1]), 1)
-		err := c.outside.WriteTo(hostinfo.HandshakePacket[0], addr)
+	hostinfo.remotes.ForEach(hm.mainHostMap.preferredRanges, func(addr *udp.Addr, _ bool) {
+		hm.messageMetrics.Tx(header.Handshake, header.MessageSubType(hostinfo.HandshakePacket[0][1]), 1)
+		err := hm.outside.WriteTo(hostinfo.HandshakePacket[0], addr)
 		if err != nil {
-			hostinfo.logger(c.l).WithField("udpAddr", addr).
+			hostinfo.logger(hm.l).WithField("udpAddr", addr).
 				WithField("initiatorIndex", hostinfo.localIndexId).
 				WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
 				WithError(err).Error("Failed to send handshake message")
@@ -196,63 +252,63 @@ func (c *HandshakeManager) handleOutbound(vpnIp iputil.VpnIp, lighthouseTriggere
 	// Don't be too noisy or confusing if we fail to send a handshake - if we don't get through we'll eventually log a timeout,
 	// so only log when the list of remotes has changed
 	if remotesHaveChanged {
-		hostinfo.logger(c.l).WithField("udpAddrs", sentTo).
+		hostinfo.logger(hm.l).WithField("udpAddrs", sentTo).
 			WithField("initiatorIndex", hostinfo.localIndexId).
 			WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
 			Info("Handshake message sent")
-	} else if c.l.IsLevelEnabled(logrus.DebugLevel) {
-		hostinfo.logger(c.l).WithField("udpAddrs", sentTo).
+	} else if hm.l.IsLevelEnabled(logrus.DebugLevel) {
+		hostinfo.logger(hm.l).WithField("udpAddrs", sentTo).
 			WithField("initiatorIndex", hostinfo.localIndexId).
 			WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
 			Debug("Handshake message sent")
 	}
 
-	if c.config.useRelays && len(hostinfo.remotes.relays) > 0 {
-		hostinfo.logger(c.l).WithField("relays", hostinfo.remotes.relays).Info("Attempt to relay through hosts")
+	if hm.config.useRelays && len(hostinfo.remotes.relays) > 0 {
+		hostinfo.logger(hm.l).WithField("relays", hostinfo.remotes.relays).Info("Attempt to relay through hosts")
 		// Send a RelayRequest to all known Relay IP's
 		for _, relay := range hostinfo.remotes.relays {
 			// Don't relay to myself, and don't relay through the host I'm trying to connect to
-			if *relay == vpnIp || *relay == c.lightHouse.myVpnIp {
+			if *relay == vpnIp || *relay == hm.lightHouse.myVpnIp {
 				continue
 			}
-			relayHostInfo := c.mainHostMap.QueryVpnIp(*relay)
+			relayHostInfo := hm.mainHostMap.QueryVpnIp(*relay)
 			if relayHostInfo == nil || relayHostInfo.remote == nil {
-				hostinfo.logger(c.l).WithField("relay", relay.String()).Info("Establish tunnel to relay target")
-				c.f.Handshake(*relay)
+				hostinfo.logger(hm.l).WithField("relay", relay.String()).Info("Establish tunnel to relay target")
+				hm.f.Handshake(*relay)
 				continue
 			}
 			// Check the relay HostInfo to see if we already established a relay through it
 			if existingRelay, ok := relayHostInfo.relayState.QueryRelayForByIp(vpnIp); ok {
 				switch existingRelay.State {
 				case Established:
-					hostinfo.logger(c.l).WithField("relay", relay.String()).Info("Send handshake via relay")
-					c.f.SendVia(relayHostInfo, existingRelay, hostinfo.HandshakePacket[0], make([]byte, 12), make([]byte, mtu), false)
+					hostinfo.logger(hm.l).WithField("relay", relay.String()).Info("Send handshake via relay")
+					hm.f.SendVia(relayHostInfo, existingRelay, hostinfo.HandshakePacket[0], make([]byte, 12), make([]byte, mtu), false)
 				case Requested:
-					hostinfo.logger(c.l).WithField("relay", relay.String()).Info("Re-send CreateRelay request")
+					hostinfo.logger(hm.l).WithField("relay", relay.String()).Info("Re-send CreateRelay request")
 					// Re-send the CreateRelay request, in case the previous one was lost.
 					m := NebulaControl{
 						Type:                NebulaControl_CreateRelayRequest,
 						InitiatorRelayIndex: existingRelay.LocalIndex,
-						RelayFromIp:         uint32(c.lightHouse.myVpnIp),
+						RelayFromIp:         uint32(hm.lightHouse.myVpnIp),
 						RelayToIp:           uint32(vpnIp),
 					}
 					msg, err := m.Marshal()
 					if err != nil {
-						hostinfo.logger(c.l).
+						hostinfo.logger(hm.l).
 							WithError(err).
 							Error("Failed to marshal Control message to create relay")
 					} else {
 						// This must send over the hostinfo, not over hm.Hosts[ip]
-						c.f.SendMessageToHostInfo(header.Control, 0, relayHostInfo, msg, make([]byte, 12), make([]byte, mtu))
-						c.l.WithFields(logrus.Fields{
-							"relayFrom":           c.lightHouse.myVpnIp,
+						hm.f.SendMessageToHostInfo(header.Control, 0, relayHostInfo, msg, make([]byte, 12), make([]byte, mtu))
+						hm.l.WithFields(logrus.Fields{
+							"relayFrom":           hm.lightHouse.myVpnIp,
 							"relayTo":             vpnIp,
 							"initiatorRelayIndex": existingRelay.LocalIndex,
 							"relay":               *relay}).
 							Info("send CreateRelayRequest")
 					}
 				default:
-					hostinfo.logger(c.l).
+					hostinfo.logger(hm.l).
 						WithField("vpnIp", vpnIp).
 						WithField("state", existingRelay.State).
 						WithField("relay", relayHostInfo.vpnIp).
@@ -261,26 +317,26 @@ func (c *HandshakeManager) handleOutbound(vpnIp iputil.VpnIp, lighthouseTriggere
 			} else {
 				// No relays exist or requested yet.
 				if relayHostInfo.remote != nil {
-					idx, err := AddRelay(c.l, relayHostInfo, c.mainHostMap, vpnIp, nil, TerminalType, Requested)
+					idx, err := AddRelay(hm.l, relayHostInfo, hm.mainHostMap, vpnIp, nil, TerminalType, Requested)
 					if err != nil {
-						hostinfo.logger(c.l).WithField("relay", relay.String()).WithError(err).Info("Failed to add relay to hostmap")
+						hostinfo.logger(hm.l).WithField("relay", relay.String()).WithError(err).Info("Failed to add relay to hostmap")
 					}
 
 					m := NebulaControl{
 						Type:                NebulaControl_CreateRelayRequest,
 						InitiatorRelayIndex: idx,
-						RelayFromIp:         uint32(c.lightHouse.myVpnIp),
+						RelayFromIp:         uint32(hm.lightHouse.myVpnIp),
 						RelayToIp:           uint32(vpnIp),
 					}
 					msg, err := m.Marshal()
 					if err != nil {
-						hostinfo.logger(c.l).
+						hostinfo.logger(hm.l).
 							WithError(err).
 							Error("Failed to marshal Control message to create relay")
 					} else {
-						c.f.SendMessageToHostInfo(header.Control, 0, relayHostInfo, msg, make([]byte, 12), make([]byte, mtu))
-						c.l.WithFields(logrus.Fields{
-							"relayFrom":           c.lightHouse.myVpnIp,
+						hm.f.SendMessageToHostInfo(header.Control, 0, relayHostInfo, msg, make([]byte, 12), make([]byte, mtu))
+						hm.l.WithFields(logrus.Fields{
+							"relayFrom":           hm.lightHouse.myVpnIp,
 							"relayTo":             vpnIp,
 							"initiatorRelayIndex": idx,
 							"relay":               *relay}).
@@ -293,13 +349,13 @@ func (c *HandshakeManager) handleOutbound(vpnIp iputil.VpnIp, lighthouseTriggere
 
 	// If a lighthouse triggered this attempt then we are still in the timer wheel and do not need to re-add
 	if !lighthouseTriggered {
-		c.OutboundHandshakeTimer.Add(vpnIp, c.config.tryInterval*time.Duration(hostinfo.HandshakeCounter))
+		hm.OutboundHandshakeTimer.Add(vpnIp, hm.config.tryInterval*time.Duration(hh.counter))
 	}
 }
 
 // GetOrHandshake will try to find a hostinfo with a fully formed tunnel or start a new handshake if one is not present
 // The 2nd argument will be true if the hostinfo is ready to transmit traffic
-func (hm *HandshakeManager) GetOrHandshake(vpnIp iputil.VpnIp, cacheCb func(*HostInfo)) (*HostInfo, bool) {
+func (hm *HandshakeManager) GetOrHandshake(vpnIp iputil.VpnIp, cacheCb func(*HandshakeHostInfo)) (*HostInfo, bool) {
 	// Check the main hostmap and maintain a read lock if our host is not there
 	hm.mainHostMap.RLock()
 	if h, ok := hm.mainHostMap.Hosts[vpnIp]; ok {
@@ -316,16 +372,16 @@ func (hm *HandshakeManager) GetOrHandshake(vpnIp iputil.VpnIp, cacheCb func(*Hos
 }
 
 // StartHandshake will ensure a handshake is currently being attempted for the provided vpn ip
-func (hm *HandshakeManager) StartHandshake(vpnIp iputil.VpnIp, cacheCb func(*HostInfo)) *HostInfo {
+func (hm *HandshakeManager) StartHandshake(vpnIp iputil.VpnIp, cacheCb func(*HandshakeHostInfo)) *HostInfo {
 	hm.Lock()
 
-	if hostinfo, ok := hm.vpnIps[vpnIp]; ok {
+	if hh, ok := hm.vpnIps[vpnIp]; ok {
 		// We are already trying to handshake with this vpn ip
 		if cacheCb != nil {
-			cacheCb(hostinfo)
+			cacheCb(hh)
 		}
 		hm.Unlock()
-		return hostinfo
+		return hh.hostinfo
 	}
 
 	hostinfo := &HostInfo{
@@ -338,12 +394,16 @@ func (hm *HandshakeManager) StartHandshake(vpnIp iputil.VpnIp, cacheCb func(*Hos
 		},
 	}
 
-	hm.vpnIps[vpnIp] = hostinfo
+	hh := &HandshakeHostInfo{
+		hostinfo:  hostinfo,
+		startTime: time.Now(),
+	}
+	hm.vpnIps[vpnIp] = hh
 	hm.metricInitiated.Inc(1)
 	hm.OutboundHandshakeTimer.Add(vpnIp, hm.config.tryInterval)
 
 	if cacheCb != nil {
-		cacheCb(hostinfo)
+		cacheCb(hh)
 	}
 
 	// If this is a static host, we don't need to wait for the HostQueryReply
@@ -416,8 +476,8 @@ func (c *HandshakeManager) CheckAndComplete(hostinfo *HostInfo, handshakePacket
 		return existingIndex, ErrLocalIndexCollision
 	}
 
-	existingIndex, found = c.indexes[hostinfo.localIndexId]
-	if found && existingIndex != hostinfo {
+	existingPendingIndex, found := c.indexes[hostinfo.localIndexId]
+	if found && existingPendingIndex.hostinfo != hostinfo {
 		// We have a collision, but for a different hostinfo
 		return existingIndex, ErrLocalIndexCollision
 	}
@@ -461,7 +521,7 @@ func (hm *HandshakeManager) Complete(hostinfo *HostInfo, f *Interface) {
 // allocateIndex generates a unique localIndexId for this HostInfo
 // and adds it to the pendingHostMap. Will error if we are unable to generate
 // a unique localIndexId
-func (hm *HandshakeManager) allocateIndex(h *HostInfo) error {
+func (hm *HandshakeManager) allocateIndex(hh *HandshakeHostInfo) error {
 	hm.mainHostMap.RLock()
 	defer hm.mainHostMap.RUnlock()
 	hm.Lock()
@@ -477,8 +537,8 @@ func (hm *HandshakeManager) allocateIndex(h *HostInfo) error {
 		_, inMain := hm.mainHostMap.Indexes[index]
 
 		if !inMain && !inPending {
-			h.localIndexId = index
-			hm.indexes[index] = h
+			hh.hostinfo.localIndexId = index
+			hm.indexes[index] = hh
 			return nil
 		}
 	}
@@ -495,12 +555,12 @@ func (c *HandshakeManager) DeleteHostInfo(hostinfo *HostInfo) {
 func (c *HandshakeManager) unlockedDeleteHostInfo(hostinfo *HostInfo) {
 	delete(c.vpnIps, hostinfo.vpnIp)
 	if len(c.vpnIps) == 0 {
-		c.vpnIps = map[iputil.VpnIp]*HostInfo{}
+		c.vpnIps = map[iputil.VpnIp]*HandshakeHostInfo{}
 	}
 
 	delete(c.indexes, hostinfo.localIndexId)
 	if len(c.vpnIps) == 0 {
-		c.indexes = map[uint32]*HostInfo{}
+		c.indexes = map[uint32]*HandshakeHostInfo{}
 	}
 
 	if c.l.Level >= logrus.DebugLevel {
@@ -510,16 +570,33 @@ func (c *HandshakeManager) unlockedDeleteHostInfo(hostinfo *HostInfo) {
 	}
 }
 
-func (c *HandshakeManager) QueryVpnIp(vpnIp iputil.VpnIp) *HostInfo {
-	c.RLock()
-	defer c.RUnlock()
-	return c.vpnIps[vpnIp]
+func (hm *HandshakeManager) QueryVpnIp(vpnIp iputil.VpnIp) *HostInfo {
+	hh := hm.queryVpnIp(vpnIp)
+	if hh != nil {
+		return hh.hostinfo
+	}
+	return nil
+
 }
 
-func (c *HandshakeManager) QueryIndex(index uint32) *HostInfo {
-	c.RLock()
-	defer c.RUnlock()
-	return c.indexes[index]
+func (hm *HandshakeManager) queryVpnIp(vpnIp iputil.VpnIp) *HandshakeHostInfo {
+	hm.RLock()
+	defer hm.RUnlock()
+	return hm.vpnIps[vpnIp]
+}
+
+func (hm *HandshakeManager) QueryIndex(index uint32) *HostInfo {
+	hh := hm.queryIndex(index)
+	if hh != nil {
+		return hh.hostinfo
+	}
+	return nil
+}
+
+func (hm *HandshakeManager) queryIndex(index uint32) *HandshakeHostInfo {
+	hm.RLock()
+	defer hm.RUnlock()
+	return hm.indexes[index]
 }
 
 func (c *HandshakeManager) GetPreferredRanges() []*net.IPNet {
@@ -531,7 +608,7 @@ func (c *HandshakeManager) ForEachVpnIp(f controlEach) {
 	defer c.RUnlock()
 
 	for _, v := range c.vpnIps {
-		f(v)
+		f(v.hostinfo)
 	}
 }
 
@@ -540,7 +617,7 @@ func (c *HandshakeManager) ForEachIndex(f controlEach) {
 	defer c.RUnlock()
 
 	for _, v := range c.indexes {
-		f(v)
+		f(v.hostinfo)
 	}
 }