Merge pull request #675 from Arceliar/buffers

Buffers

src/yggdrasil/api.go

@@ -110,7 +110,8 @@ type Session struct {
 // there is exactly one entry then this node is not connected to any other nodes
 // and is therefore isolated.
 func (c *Core) GetPeers() []Peer {
-	ports := c.peers.ports.Load().(map[switchPort]*peer)
+	var ports map[switchPort]*peer
+	phony.Block(&c.peers, func() { ports = c.peers.ports })
 	var peers []Peer
 	var ps []switchPort
 	for port := range ports {
@@ -143,10 +144,14 @@ func (c *Core) GetPeers() []Peer {
 // isolated or not connected to any peers.
 func (c *Core) GetSwitchPeers() []SwitchPeer {
 	var switchpeers []SwitchPeer
-	table := c.switchTable.table.Load().(lookupTable)
+	var table *lookupTable
-	peers := c.peers.ports.Load().(map[switchPort]*peer)
+	var ports map[switchPort]*peer
+	phony.Block(&c.peers, func() {
+		table = c.peers.table
+		ports = c.peers.ports
+	})
 	for _, elem := range table.elems {
-		peer, isIn := peers[elem.port]
+		peer, isIn := ports[elem.port]
 		if !isIn {
 			continue
 		}
@@ -194,34 +199,6 @@ func (c *Core) GetDHT() []DHTEntry {
 	return dhtentries
 }
 
-// GetSwitchQueues returns information about the switch queues that are
-// currently in effect. These values can change within an instant.
-func (c *Core) GetSwitchQueues() SwitchQueues {
-	var switchqueues SwitchQueues
-	switchTable := &c.switchTable
-	getSwitchQueues := func() {
-		switchqueues = SwitchQueues{
-			Count:        uint64(len(switchTable.queues.bufs)),
-			Size:         switchTable.queues.size,
-			HighestCount: uint64(switchTable.queues.maxbufs),
-			HighestSize:  switchTable.queues.maxsize,
-			MaximumSize:  switchTable.queues.totalMaxSize,
-		}
-		for k, v := range switchTable.queues.bufs {
-			nexthop := switchTable.bestPortForCoords([]byte(k))
-			queue := SwitchQueue{
-				ID:      k,
-				Size:    v.size,
-				Packets: uint64(len(v.packets)),
-				Port:    uint64(nexthop),
-			}
-			switchqueues.Queues = append(switchqueues.Queues, queue)
-		}
-	}
-	phony.Block(&c.switchTable, getSwitchQueues)
-	return switchqueues
-}
-
 // GetSessions returns a list of open sessions from this node to other nodes.
 func (c *Core) GetSessions() []Session {
 	var sessions []Session
@@ -324,8 +301,11 @@ func (c *Core) EncryptionPublicKey() string {
 // connected to any other nodes (effectively making you the root of a
 // single-node network).
 func (c *Core) Coords() []uint64 {
-	table := c.switchTable.table.Load().(lookupTable)
+	var coords []byte
-	return wire_coordsBytestoUint64s(table.self.getCoords())
+	phony.Block(&c.router, func() {
+		coords = c.router.table.self.getCoords()
+	})
+	return wire_coordsBytestoUint64s(coords)
 }
 
 // Address gets the IPv6 address of the Yggdrasil node. This is always a /128
@@ -489,7 +469,11 @@ func (c *Core) CallPeer(addr string, sintf string) error {
 // DisconnectPeer disconnects a peer once. This should be specified as a port
 // number.
 func (c *Core) DisconnectPeer(port uint64) error {
-	c.peers.removePeer(switchPort(port))
+	c.peers.Act(nil, func() {
+		if p, isIn := c.peers.ports[switchPort(port)]; isIn {
+			p.Act(&c.peers, p._removeSelf)
+		}
+	})
 	return nil
 }
 

src/yggdrasil/core.go

@@ -198,8 +198,10 @@ func (c *Core) _stop() {
 		c.addPeerTimer.Stop()
 	}
 	c.link.stop()
+	/* FIXME this deadlocks, need a waitgroup or something to coordinate shutdown
 	for _, peer := range c.GetPeers() {
 		c.DisconnectPeer(peer.Port)
 	}
+	*/
 	c.log.Infoln("Stopped")
 }

src/yggdrasil/dht.go

@@ -186,11 +186,9 @@ func dht_ordered(first, second, third *crypto.NodeID) bool {
 // Update info about the node that sent the request.
 func (t *dht) handleReq(req *dhtReq) {
 	// Send them what they asked for
-	loc := t.router.core.switchTable.getLocator()
-	coords := loc.getCoords()
 	res := dhtRes{
 		Key:    t.router.core.boxPub,
-		Coords: coords,
+		Coords: t.router.table.self.getCoords(),
 		Dest:   req.Dest,
 		Infos:  t.lookup(&req.Dest, false),
 	}
@@ -300,11 +298,9 @@ func (t *dht) ping(info *dhtInfo, target *crypto.NodeID) {
 	if target == nil {
 		target = &t.nodeID
 	}
-	loc := t.router.core.switchTable.getLocator()
-	coords := loc.getCoords()
 	req := dhtReq{
 		Key:    t.router.core.boxPub,
-		Coords: coords,
+		Coords: t.router.table.self.getCoords(),
 		Dest:   *target,
 	}
 	t.sendReq(&req, info)
@@ -378,7 +374,7 @@ func (t *dht) getImportant() []*dhtInfo {
 		})
 		// Keep the ones that are no further than the closest seen so far
 		minDist := ^uint64(0)
-		loc := t.router.core.switchTable.getLocator()
+		loc := t.router.table.self
 		important := infos[:0]
 		for _, info := range infos {
 			dist := uint64(loc.dist(info.coords))
@@ -416,7 +412,7 @@ func (t *dht) isImportant(ninfo *dhtInfo) bool {
 	}
 	important := t.getImportant()
 	// Check if ninfo is of equal or greater importance to what we already know
-	loc := t.router.core.switchTable.getLocator()
+	loc := t.router.table.self
 	ndist := uint64(loc.dist(ninfo.coords))
 	minDist := ^uint64(0)
 	for _, info := range important {

src/yggdrasil/link.go

@@ -62,7 +62,7 @@ type linkInterface struct {
 	keepAliveTimer *time.Timer // Fires to send keep-alive traffic
 	stallTimer     *time.Timer // Fires to signal that no incoming traffic (including keep-alive) has been seen
 	closeTimer     *time.Timer // Fires when the link has been idle so long we need to close it
-	inSwitch       bool        // True if the switch is tracking this link
+	isIdle         bool        // True if the peer actor knows the link is idle
 	stalled        bool        // True if we haven't been receiving any response traffic
 	unstalled      bool        // False if an idle notification to the switch hasn't been sent because we stalled (or are first starting up)
 }
@@ -217,19 +217,30 @@ func (intf *linkInterface) handler() error {
 	intf.link.mutex.Unlock()
 	// Create peer
 	shared := crypto.GetSharedKey(myLinkPriv, &meta.link)
-	intf.peer = intf.link.core.peers.newPeer(&meta.box, &meta.sig, shared, intf, func() { intf.msgIO.close() })
+	phony.Block(&intf.link.core.peers, func() {
+		// FIXME don't use phony.Block, it's bad practice, even if it's safe here
+		intf.peer = intf.link.core.peers._newPeer(&meta.box, &meta.sig, shared, intf, func() { intf.msgIO.close() })
+	})
 	if intf.peer == nil {
 		return errors.New("failed to create peer")
 	}
 	defer func() {
 		// More cleanup can go here
-		intf.link.core.peers.removePeer(intf.peer.port)
+		intf.peer.Act(nil, intf.peer._removeSelf)
 	}()
 	intf.peer.out = func(msgs [][]byte) {
-		intf.writer.sendFrom(intf.peer, msgs, false)
+		// nil to prevent it from blocking if the link is somehow frozen
+		// this is safe because another packet won't be sent until the link notifies
+		//  the peer that it's ready for one
+		intf.writer.sendFrom(nil, msgs, false)
 	}
 	intf.peer.linkOut = func(bs []byte) {
-		intf.writer.sendFrom(intf.peer, [][]byte{bs}, true)
+		// nil to prevent it from blocking if the link is somehow frozen
+		// FIXME this is hypothetically not safe, the peer shouldn't be sending
+		//  additional packets until this one finishes, otherwise this could leak
+		//  memory if writing happens slower than link packets are generated...
+		//  that seems unlikely, so it's a lesser evil than deadlocking for now
+		intf.writer.sendFrom(nil, [][]byte{bs}, true)
 	}
 	themAddr := address.AddrForNodeID(crypto.GetNodeID(&intf.info.box))
 	themAddrString := net.IP(themAddr[:]).String()
@@ -275,20 +286,13 @@ const (
 func (intf *linkInterface) notifySending(size int, isLinkTraffic bool) {
 	intf.Act(&intf.writer, func() {
 		if !isLinkTraffic {
-			intf.inSwitch = false
+			intf.isIdle = false
 		}
 		intf.sendTimer = time.AfterFunc(sendTime, intf.notifyBlockedSend)
 		intf._cancelStallTimer()
 	})
 }
 
-// called by an AfterFunc if we seem to be blocked in a send syscall for a long time
-func (intf *linkInterface) _notifySyscall() {
-	intf.link.core.switchTable.Act(intf, func() {
-		intf.link.core.switchTable._sendingIn(intf.peer.port)
-	})
-}
-
 // we just sent something, so cancel any pending timer to send keep-alive traffic
 func (intf *linkInterface) _cancelStallTimer() {
 	if intf.stallTimer != nil {
@@ -304,7 +308,7 @@ func (intf *linkInterface) notifyBlockedSend() {
 	intf.Act(nil, func() {
 		if intf.sendTimer != nil {
 			//As far as we know, we're still trying to send, and the timer fired.
-			intf.link.core.switchTable.blockPeer(intf.peer.port)
+			intf.link.core.switchTable.blockPeer(intf, intf.peer.port)
 		}
 	})
 }
@@ -315,7 +319,7 @@ func (intf *linkInterface) notifySent(size int, isLinkTraffic bool) {
 		intf.sendTimer.Stop()
 		intf.sendTimer = nil
 		if !isLinkTraffic {
-			intf._notifySwitch()
+			intf._notifyIdle()
 		}
 		if size > 0 && intf.stallTimer == nil {
 			intf.stallTimer = time.AfterFunc(stallTime, intf.notifyStalled)
@@ -324,15 +328,13 @@ func (intf *linkInterface) notifySent(size int, isLinkTraffic bool) {
 }
 
 // Notify the switch that we're ready for more traffic, assuming we're not in a stalled state
-func (intf *linkInterface) _notifySwitch() {
+func (intf *linkInterface) _notifyIdle() {
-	if !intf.inSwitch {
+	if !intf.isIdle {
 		if intf.stalled {
 			intf.unstalled = false
 		} else {
-			intf.inSwitch = true
+			intf.isIdle = true
-			intf.link.core.switchTable.Act(intf, func() {
+			intf.peer.Act(intf, intf.peer._handleIdle)
-				intf.link.core.switchTable._idleIn(intf.peer.port)
-			})
 		}
 	}
 }
@@ -344,7 +346,7 @@ func (intf *linkInterface) notifyStalled() {
 			intf.stallTimer.Stop()
 			intf.stallTimer = nil
 			intf.stalled = true
-			intf.link.core.switchTable.blockPeer(intf.peer.port)
+			intf.link.core.switchTable.blockPeer(intf, intf.peer.port)
 		}
 	})
 }
@@ -368,7 +370,7 @@ func (intf *linkInterface) notifyRead(size int) {
 		}
 		intf.stalled = false
 		if !intf.unstalled {
-			intf._notifySwitch()
+			intf._notifyIdle()
 			intf.unstalled = true
 		}
 		if size > 0 && intf.stallTimer == nil {
@@ -402,19 +404,7 @@ func (w *linkWriter) sendFrom(from phony.Actor, bss [][]byte, isLinkTraffic bool
 			size += len(bs)
 		}
 		w.intf.notifySending(size, isLinkTraffic)
-		// start a timer that will fire if we get stuck in writeMsgs for an oddly long time
-		var once sync.Once
-		timer := time.AfterFunc(time.Millisecond, func() {
-			// 1 ms is kind of arbitrary
-			// the rationale is that this should be very long compared to a syscall
-			// but it's still short compared to end-to-end latency or human perception
-			once.Do(func() {
-				w.intf.Act(nil, w.intf._notifySyscall)
-			})
-		})
 		w.intf.msgIO.writeMsgs(bss)
-		// Make sure we either stop the timer from doing anything or wait until it's done
-		once.Do(func() { timer.Stop() })
 		w.intf.notifySent(size, isLinkTraffic)
 		// Cleanup
 		for _, bs := range bss {

src/yggdrasil/nodeinfo.go

@@ -18,6 +18,7 @@ type nodeinfo struct {
 	myNodeInfo NodeInfoPayload
 	callbacks  map[crypto.BoxPubKey]nodeinfoCallback
 	cache      map[crypto.BoxPubKey]nodeinfoCached
+	table      *lookupTable
 }
 
 type nodeinfoCached struct {
@@ -187,9 +188,9 @@ func (m *nodeinfo) sendNodeInfo(key crypto.BoxPubKey, coords []byte, isResponse
 }
 
 func (m *nodeinfo) _sendNodeInfo(key crypto.BoxPubKey, coords []byte, isResponse bool) {
-	table := m.core.switchTable.table.Load().(lookupTable)
+	loc := m.table.self
 	nodeinfo := nodeinfoReqRes{
-		SendCoords: table.self.getCoords(),
+		SendCoords: loc.getCoords(),
 		IsResponse: isResponse,
 		NodeInfo:   m._getNodeInfo(),
 	}

src/yggdrasil/packetqueue.go

@@ -0,0 +1,126 @@
+package yggdrasil
+
+import (
+	"time"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/util"
+)
+
+// TODO take max size from config
+const MAX_PACKET_QUEUE_SIZE = 4 * 1048576 // 4 MB
+
+type pqStreamID string
+
+type pqPacketInfo struct {
+	packet []byte
+	time   time.Time
+}
+
+type pqStream struct {
+	infos []pqPacketInfo
+	size  uint64
+}
+
+// TODO separate queues per e.g. traffic flow
+type packetQueue struct {
+	streams map[pqStreamID]pqStream
+	size    uint64
+}
+
+func (q *packetQueue) cleanup() {
+	for q.size > MAX_PACKET_QUEUE_SIZE {
+		// TODO? drop from a random stream
+		//  odds proportional to size? bandwidth?
+		//  always using the worst is exploitable -> flood 1 packet per random stream
+		// find the stream that's using the most bandwidth
+		now := time.Now()
+		var worst pqStreamID
+		for id := range q.streams {
+			worst = id
+			break // get a random ID to start
+		}
+		worstStream := q.streams[worst]
+		worstSize := float64(worstStream.size)
+		worstAge := now.Sub(worstStream.infos[0].time).Seconds()
+		for id, stream := range q.streams {
+			thisSize := float64(stream.size)
+			thisAge := now.Sub(stream.infos[0].time).Seconds()
+			// cross multiply to avoid division by zero issues
+			if worstSize*thisAge < thisSize*worstAge {
+				// worstSize/worstAge < thisSize/thisAge -> this uses more bandwidth
+				worst = id
+				worstStream = stream
+				worstSize = thisSize
+				worstAge = thisAge
+			}
+		}
+		// Drop the oldest packet from the worst stream
+		packet := worstStream.infos[0].packet
+		worstStream.infos = worstStream.infos[1:]
+		worstStream.size -= uint64(len(packet))
+		q.size -= uint64(len(packet))
+		util.PutBytes(packet)
+		// save the modified stream to queues
+		if len(worstStream.infos) > 0 {
+			q.streams[worst] = worstStream
+		} else {
+			delete(q.streams, worst)
+		}
+	}
+}
+
+func (q *packetQueue) push(packet []byte) {
+	if q.streams == nil {
+		q.streams = make(map[pqStreamID]pqStream)
+	}
+	// get stream
+	id := pqStreamID(peer_getPacketCoords(packet)) // just coords for now
+	stream := q.streams[id]
+	// update stream
+	stream.infos = append(stream.infos, pqPacketInfo{packet, time.Now()})
+	stream.size += uint64(len(packet))
+	// save update to queues
+	q.streams[id] = stream
+	q.size += uint64(len(packet))
+	q.cleanup()
+}
+
+func (q *packetQueue) pop() ([]byte, bool) {
+	if len(q.streams) > 0 {
+		// get the stream that uses the least bandwidth
+		now := time.Now()
+		var best pqStreamID
+		for id := range q.streams {
+			best = id
+			break // get a random ID to start
+		}
+		bestStream := q.streams[best]
+		bestSize := float64(bestStream.size)
+		bestAge := now.Sub(bestStream.infos[0].time).Seconds()
+		for id, stream := range q.streams {
+			thisSize := float64(stream.size)
+			thisAge := now.Sub(stream.infos[0].time).Seconds()
+			// cross multiply to avoid division by zero issues
+			if bestSize*thisAge > thisSize*bestAge {
+				// bestSize/bestAge > thisSize/thisAge -> this uses less bandwidth
+				best = id
+				bestStream = stream
+				bestSize = thisSize
+				bestAge = thisAge
+			}
+		}
+		// get the oldest packet from the best stream
+		packet := bestStream.infos[0].packet
+		bestStream.infos = bestStream.infos[1:]
+		bestStream.size -= uint64(len(packet))
+		q.size -= uint64(len(packet))
+		// save the modified stream to queues
+		if len(bestStream.infos) > 0 {
+			q.streams[best] = bestStream
+		} else {
+			delete(q.streams, best)
+		}
+		return packet, true
+	}
+	return nil, false
+}

src/yggdrasil/peer.go

@@ -6,8 +6,6 @@ package yggdrasil
 
 import (
 	"encoding/hex"
-	"sync"
-	"sync/atomic"
 	"time"
 
 	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
@@ -21,17 +19,17 @@ import (
 // In most cases, this involves passing the packet to the handler for outgoing traffic to another peer.
 // In other cases, its link protocol traffic is used to build the spanning tree, in which case this checks signatures and passes the message along to the switch.
 type peers struct {
+	phony.Inbox
 	core  *Core
-	mutex sync.Mutex   // Synchronize writes to atomic
+	ports map[switchPort]*peer // use CoW semantics, share updated version with each peer
-	ports atomic.Value //map[switchPort]*peer, use CoW semantics
+	table *lookupTable         // Sent from switch, share updated version with each peer
 }
 
 // Initializes the peers struct.
 func (ps *peers) init(c *Core) {
-	ps.mutex.Lock()
-	defer ps.mutex.Unlock()
-	ps.putPorts(make(map[switchPort]*peer))
 	ps.core = c
+	ps.ports = make(map[switchPort]*peer)
+	ps.table = new(lookupTable)
 }
 
 func (ps *peers) reconfigure() {
@@ -80,16 +78,6 @@ func (ps *peers) getAllowedEncryptionPublicKeys() []string {
 	return ps.core.config.Current.AllowedEncryptionPublicKeys
 }
 
-// Atomically gets a map[switchPort]*peer of known peers.
-func (ps *peers) getPorts() map[switchPort]*peer {
-	return ps.ports.Load().(map[switchPort]*peer)
-}
-
-// Stores a map[switchPort]*peer (note that you should take a mutex before store operations to avoid conflicts with other nodes attempting to read/change/store at the same time).
-func (ps *peers) putPorts(ports map[switchPort]*peer) {
-	ps.ports.Store(ports)
-}
-
 // Information known about a peer, including their box/sig keys, precomputed shared keys (static and ephemeral) and a handler for their outgoing traffic
 type peer struct {
 	phony.Inbox
@@ -110,10 +98,33 @@ type peer struct {
 	// The below aren't actually useful internally, they're just gathered for getPeers statistics
 	bytesSent  uint64
 	bytesRecvd uint64
+	ports      map[switchPort]*peer
+	table      *lookupTable
+	queue      packetQueue
+	idle       bool
+}
+
+func (ps *peers) updateTables(from phony.Actor, table *lookupTable) {
+	ps.Act(from, func() {
+		ps.table = table
+		ps._updatePeers()
+	})
+}
+
+func (ps *peers) _updatePeers() {
+	ports := ps.ports
+	table := ps.table
+	for _, peer := range ps.ports {
+		p := peer // peer is mutated during iteration
+		p.Act(ps, func() {
+			p.ports = ports
+			p.table = table
+		})
+	}
 }
 
 // Creates a new peer with the specified box, sig, and linkShared keys, using the lowest unoccupied port number.
-func (ps *peers) newPeer(box *crypto.BoxPubKey, sig *crypto.SigPubKey, linkShared *crypto.BoxSharedKey, intf *linkInterface, closer func()) *peer {
+func (ps *peers) _newPeer(box *crypto.BoxPubKey, sig *crypto.SigPubKey, linkShared *crypto.BoxSharedKey, intf *linkInterface, closer func()) *peer {
 	now := time.Now()
 	p := peer{box: *box,
 		sig:        *sig,
@@ -125,9 +136,7 @@ func (ps *peers) newPeer(box *crypto.BoxPubKey, sig *crypto.SigPubKey, linkShare
 		core:       ps.core,
 		intf:       intf,
 	}
-	ps.mutex.Lock()
+	oldPorts := ps.ports
-	defer ps.mutex.Unlock()
-	oldPorts := ps.getPorts()
 	newPorts := make(map[switchPort]*peer)
 	for k, v := range oldPorts {
 		newPorts[k] = v
@@ -139,46 +148,49 @@ func (ps *peers) newPeer(box *crypto.BoxPubKey, sig *crypto.SigPubKey, linkShare
 			break
 		}
 	}
-	ps.putPorts(newPorts)
+	ps.ports = newPorts
+	ps._updatePeers()
 	return &p
 }
 
-// Removes a peer for a given port, if one exists.
+func (p *peer) _removeSelf() {
-func (ps *peers) removePeer(port switchPort) {
+	p.core.peers.Act(p, func() {
-	if port == 0 {
+		p.core.peers._removePeer(p)
-		return
-	} // Can't remove self peer
-	phony.Block(&ps.core.router, func() {
-		ps.core.switchTable.forgetPeer(port)
 	})
-	ps.mutex.Lock()
+}
-	oldPorts := ps.getPorts()
+
-	p, isIn := oldPorts[port]
+// Removes a peer for a given port, if one exists.
+func (ps *peers) _removePeer(p *peer) {
+	if q := ps.ports[p.port]; p.port == 0 || q != p {
+		return
+	} // Can't remove self peer or nonexistant peer
+	ps.core.switchTable.forgetPeer(ps, p.port)
+	oldPorts := ps.ports
 	newPorts := make(map[switchPort]*peer)
 	for k, v := range oldPorts {
 		newPorts[k] = v
 	}
-	delete(newPorts, port)
+	delete(newPorts, p.port)
-	ps.putPorts(newPorts)
+	if p.close != nil {
-	ps.mutex.Unlock()
+		p.close()
-	if isIn {
-		if p.close != nil {
-			p.close()
-		}
-		close(p.done)
 	}
+	close(p.done)
+	ps.ports = newPorts
+	ps._updatePeers()
 }
 
 // If called, sends a notification to each peer that they should send a new switch message.
 // Mainly called by the switch after an update.
 func (ps *peers) sendSwitchMsgs(from phony.Actor) {
-	ports := ps.getPorts()
+	ps.Act(from, func() {
-	for _, p := range ports {
+		for _, peer := range ps.ports {
-		if p.port == 0 {
+			p := peer
-			continue
+			if p.port == 0 {
+				continue
+			}
+			p.Act(ps, p._sendSwitchMsg)
 		}
-		p.Act(from, p._sendSwitchMsg)
+	})
-	}
 }
 
 // This must be launched in a separate goroutine by whatever sets up the peer struct.
@@ -233,15 +245,26 @@ func (p *peer) _handlePacket(packet []byte) {
 	}
 }
 
+// Get the coords of a packet without decoding
+func peer_getPacketCoords(packet []byte) []byte {
+	_, pTypeLen := wire_decode_uint64(packet)
+	coords, _ := wire_decode_coords(packet[pTypeLen:])
+	return coords
+}
+
 // Called to handle traffic or protocolTraffic packets.
 // In either case, this reads from the coords of the packet header, does a switch lookup, and forwards to the next node.
 func (p *peer) _handleTraffic(packet []byte) {
-	table := p.core.switchTable.getTable()
+	if _, isIn := p.table.elems[p.port]; !isIn && p.port != 0 {
-	if _, isIn := table.elems[p.port]; !isIn && p.port != 0 {
 		// Drop traffic if the peer isn't in the switch
 		return
 	}
-	p.core.switchTable.packetInFrom(p, packet)
+	coords := peer_getPacketCoords(packet)
+	next := p.table.lookup(coords)
+	if nPeer, isIn := p.ports[next]; isIn {
+		nPeer.sendPacketsFrom(p, [][]byte{packet})
+	}
+	//p.core.switchTable.packetInFrom(p, packet)
 }
 
 func (p *peer) sendPacketsFrom(from phony.Actor, packets [][]byte) {
@@ -250,16 +273,33 @@ func (p *peer) sendPacketsFrom(from phony.Actor, packets [][]byte) {
 	})
 }
 
-// This just calls p.out(packet) for now.
 func (p *peer) _sendPackets(packets [][]byte) {
-	// Is there ever a case where something more complicated is needed?
-	// What if p.out blocks?
-	var size int
 	for _, packet := range packets {
-		size += len(packet)
+		p.queue.push(packet)
+	}
+	if p.idle {
+		p.idle = false
+		p._handleIdle()
+	}
+}
+
+func (p *peer) _handleIdle() {
+	var packets [][]byte
+	var size uint64
+	for size < 65535 {
+		if packet, success := p.queue.pop(); success {
+			packets = append(packets, packet)
+			size += uint64(len(packet))
+		} else {
+			break
+		}
+	}
+	if len(packets) > 0 {
+		p.bytesSent += uint64(size)
+		p.out(packets)
+	} else {
+		p.idle = true
 	}
-	p.bytesSent += uint64(size)
-	p.out(packets)
 }
 
 // This wraps the packet in the inner (ephemeral) and outer (permanent) crypto layers.
@@ -313,7 +353,7 @@ func (p *peer) _handleLinkTraffic(bs []byte) {
 
 // Gets a switchMsg from the switch, adds signed next-hop info for this peer, and sends it to them.
 func (p *peer) _sendSwitchMsg() {
-	msg := p.core.switchTable.getMsg()
+	msg := p.table.getMsg()
 	if msg == nil {
 		return
 	}
@@ -335,7 +375,8 @@ func (p *peer) _handleSwitchMsg(packet []byte) {
 		return
 	}
 	if len(msg.Hops) < 1 {
-		p.core.peers.removePeer(p.port)
+		p._removeSelf()
+		return
 	}
 	var loc switchLocator
 	prevKey := msg.Root
@@ -346,23 +387,31 @@ func (p *peer) _handleSwitchMsg(packet []byte) {
 		loc.coords = append(loc.coords, hop.Port)
 		bs := getBytesForSig(&hop.Next, &sigMsg)
 		if !crypto.Verify(&prevKey, bs, &hop.Sig) {
-			p.core.peers.removePeer(p.port)
+			p._removeSelf()
+			return
 		}
 		prevKey = hop.Next
 	}
-	p.core.switchTable.handleMsg(&msg, p.port)
+	p.core.switchTable.Act(p, func() {
-	if !p.core.switchTable.checkRoot(&msg) {
+		if !p.core.switchTable._checkRoot(&msg) {
-		// Bad switch message
+			// Bad switch message
-		p.dinfo = nil
+			p.Act(&p.core.switchTable, func() {
-		return
+				p.dinfo = nil
-	}
+			})
-	// Pass a message to the dht informing it that this peer (still) exists
+		} else {
-	loc.coords = loc.coords[:len(loc.coords)-1]
+			// handle the message
-	p.dinfo = &dhtInfo{
+			p.core.switchTable._handleMsg(&msg, p.port, false)
-		key:    p.box,
+			p.Act(&p.core.switchTable, func() {
-		coords: loc.getCoords(),
+				// Pass a message to the dht informing it that this peer (still) exists
-	}
+				loc.coords = loc.coords[:len(loc.coords)-1]
-	p._updateDHT()
+				p.dinfo = &dhtInfo{
+					key:    p.box,
+					coords: loc.getCoords(),
+				}
+				p._updateDHT()
+			})
+		}
+	})
 }
 
 // This generates the bytes that we sign or check the signature of for a switchMsg.

src/yggdrasil/router.go

@@ -46,6 +46,7 @@ type router struct {
 	nodeinfo nodeinfo
 	searches searches
 	sessions sessions
+	table    *lookupTable // has a copy of our locator
 }
 
 // Initializes the router struct, which includes setting up channels to/from the adapter.
@@ -61,8 +62,19 @@ func (r *router) init(core *Core) {
 			linkType: "self",
 		},
 	}
-	p := r.core.peers.newPeer(&r.core.boxPub, &r.core.sigPub, &crypto.BoxSharedKey{}, &self, nil)
+	var p *peer
-	p.out = func(packets [][]byte) { r.handlePackets(p, packets) }
+	phony.Block(&r.core.peers, func() {
+		// FIXME don't block here!
+		p = r.core.peers._newPeer(&r.core.boxPub, &r.core.sigPub, &crypto.BoxSharedKey{}, &self, nil)
+	})
+	p.out = func(packets [][]byte) {
+		r.handlePackets(p, packets)
+		r.Act(p, func() {
+			// after the router handle the packets, notify the peer that it's ready for more
+			p.Act(r, p._handleIdle)
+		})
+	}
+	p.Act(r, p._handleIdle)
 	r.out = func(bs []byte) { p.handlePacketFrom(r, bs) }
 	r.nodeinfo.init(r.core)
 	r.core.config.Mutex.RLock()
@@ -73,6 +85,21 @@ func (r *router) init(core *Core) {
 	r.sessions.init(r)
 }
 
+func (r *router) updateTable(from phony.Actor, table *lookupTable) {
+	r.Act(from, func() {
+		r.table = table
+		r.nodeinfo.Act(r, func() {
+			r.nodeinfo.table = table
+		})
+		for _, ses := range r.sessions.sinfos {
+			sinfo := ses
+			sinfo.Act(r, func() {
+				sinfo.table = table
+			})
+		}
+	})
+}
+
 // Reconfigures the router and any child modules. This should only ever be run
 // by the router actor.
 func (r *router) reconfigure() {
@@ -126,7 +153,7 @@ func (r *router) reset(from phony.Actor) {
 func (r *router) doMaintenance() {
 	phony.Block(r, func() {
 		// Any periodic maintenance stuff goes here
-		r.core.switchTable.doMaintenance()
+		r.core.switchTable.doMaintenance(r)
 		r.dht.doMaintenance()
 		r.sessions.cleanup()
 	})

src/yggdrasil/search.go

@@ -161,11 +161,10 @@ func (sinfo *searchInfo) continueSearch(infos []*dhtInfo) {
 
 // Initially start a search
 func (sinfo *searchInfo) startSearch() {
-	loc := sinfo.searches.router.core.switchTable.getLocator()
 	var infos []*dhtInfo
 	infos = append(infos, &dhtInfo{
 		key:    sinfo.searches.router.core.boxPub,
-		coords: loc.getCoords(),
+		coords: sinfo.searches.router.table.self.getCoords(),
 	})
 	// Start the search by asking ourself, useful if we're the destination
 	sinfo.continueSearch(infos)

src/yggdrasil/session.go

@@ -16,9 +16,6 @@ import (
 	"github.com/Arceliar/phony"
 )
 
-// Duration that we keep track of old nonces per session, to allow some out-of-order packet delivery
-const nonceWindow = time.Second
-
 // All the information we know about an active session.
 // This includes coords, permanent and ephemeral keys, handles and nonces, various sorts of timing information for timeout and maintenance, and some metadata for the admin API.
 type sessionInfo struct {
@@ -52,6 +49,7 @@ type sessionInfo struct {
 	cancel        util.Cancellation   // Used to terminate workers
 	conn          *Conn               // The associated Conn object
 	callbacks     []chan func()       // Finished work from crypto workers
+	table         *lookupTable        // table.self is a locator where we get our coords
 }
 
 // Represents a session ping/pong packet, and includes information like public keys, a session handle, coords, a timestamp to prevent replays, and the tun/tap MTU.
@@ -217,6 +215,7 @@ func (ss *sessions) createSession(theirPermKey *crypto.BoxPubKey) *sessionInfo {
 	sinfo.myHandle = *crypto.NewHandle()
 	sinfo.theirAddr = *address.AddrForNodeID(crypto.GetNodeID(&sinfo.theirPermPub))
 	sinfo.theirSubnet = *address.SubnetForNodeID(crypto.GetNodeID(&sinfo.theirPermPub))
+	sinfo.table = ss.router.table
 	ss.sinfos[sinfo.myHandle] = &sinfo
 	ss.byTheirPerm[sinfo.theirPermPub] = &sinfo.myHandle
 	return &sinfo
@@ -266,8 +265,7 @@ func (ss *sessions) removeSession(sinfo *sessionInfo) {
 
 // Returns a session ping appropriate for the given session info.
 func (sinfo *sessionInfo) _getPing() sessionPing {
-	loc := sinfo.sessions.router.core.switchTable.getLocator()
+	coords := sinfo.table.self.getCoords()
-	coords := loc.getCoords()
 	ping := sessionPing{
 		SendPermPub: sinfo.sessions.router.core.boxPub,
 		Handle:      sinfo.myHandle,
@@ -393,14 +391,9 @@ func (sinfo *sessionInfo) _getMTU() MTU {
 	return sinfo.myMTU
 }
 
-// Checks if a packet's nonce is recent enough to fall within the window of allowed packets, and not already received.
+// Checks if a packet's nonce is newer than any previously received
 func (sinfo *sessionInfo) _nonceIsOK(theirNonce *crypto.BoxNonce) bool {
-	// The bitmask is to allow for some non-duplicate out-of-order packets
+	return theirNonce.Minus(&sinfo.theirNonce) > 0
-	if theirNonce.Minus(&sinfo.theirNonce) > 0 {
-		// This is newer than the newest nonce we've seen
-		return true
-	}
-	return time.Since(sinfo.time) < nonceWindow
 }
 
 // Updates the nonce mask by (possibly) shifting the bitmask and setting the bit corresponding to this nonce to 1, and then updating the most recent nonce

src/yggdrasil/switch.go

@@ -12,13 +12,9 @@ package yggdrasil
 //  A little annoying to do with constant changes from backpressure
 
 import (
-	"math/rand"
-	"sync"
-	"sync/atomic"
 	"time"
 
 	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
-	"github.com/yggdrasil-network/yggdrasil-go/src/util"
 
 	"github.com/Arceliar/phony"
 )
@@ -150,6 +146,7 @@ type tableElem struct {
 type lookupTable struct {
 	self  switchLocator
 	elems map[switchPort]tableElem
+	_msg  switchMsg
 }
 
 // This is switch information which is mutable and needs to be modified by other goroutines, but is not accessed atomically.
@@ -167,17 +164,11 @@ type switchData struct {
 type switchTable struct {
 	core        *Core
 	key         crypto.SigPubKey           // Our own key
+	phony.Inbox                            // Owns the below
 	time        time.Time                  // Time when locator.tstamp was last updated
 	drop        map[crypto.SigPubKey]int64 // Tstamp associated with a dropped root
-	mutex       sync.RWMutex               // Lock for reads/writes of switchData
 	parent      switchPort                 // Port of whatever peer is our parent, or self if we're root
 	data        switchData                 //
-	updater     atomic.Value               // *sync.Once
-	table       atomic.Value               // lookupTable
-	phony.Inbox                            // Owns the below
-	queues      switch_buffers             // Queues - not atomic so ONLY use through the actor
-	idle        map[switchPort]struct{}    // idle peers - not atomic so ONLY use through the actor
-	sending     map[switchPort]struct{}    // peers known to be blocked in a send (somehow)
 }
 
 // Minimum allowed total size of switch queues.
@@ -191,21 +182,8 @@ func (t *switchTable) init(core *Core) {
 	locator := switchLocator{root: t.key, tstamp: now.Unix()}
 	peers := make(map[switchPort]peerInfo)
 	t.data = switchData{locator: locator, peers: peers}
-	t.updater.Store(&sync.Once{})
-	t.table.Store(lookupTable{})
 	t.drop = make(map[crypto.SigPubKey]int64)
-	phony.Block(t, func() {
+	phony.Block(t, t._updateTable)
-		core.config.Mutex.RLock()
-		if core.config.Current.SwitchOptions.MaxTotalQueueSize > SwitchQueueTotalMinSize {
-			t.queues.totalMaxSize = core.config.Current.SwitchOptions.MaxTotalQueueSize
-		} else {
-			t.queues.totalMaxSize = SwitchQueueTotalMinSize
-		}
-		core.config.Mutex.RUnlock()
-		t.queues.bufs = make(map[string]switch_buffer)
-		t.idle = make(map[switchPort]struct{})
-		t.sending = make(map[switchPort]struct{})
-	})
 }
 
 func (t *switchTable) reconfigure() {
@@ -214,24 +192,17 @@ func (t *switchTable) reconfigure() {
 	t.core.peers.reconfigure()
 }
 
-// Safely gets a copy of this node's locator.
-func (t *switchTable) getLocator() switchLocator {
-	t.mutex.RLock()
-	defer t.mutex.RUnlock()
-	return t.data.locator.clone()
-}
-
 // Regular maintenance to possibly timeout/reset the root and similar.
-func (t *switchTable) doMaintenance() {
+func (t *switchTable) doMaintenance(from phony.Actor) {
-	// Periodic maintenance work to keep things internally consistent
+	t.Act(from, func() {
-	t.mutex.Lock()         // Write lock
+		// Periodic maintenance work to keep things internally consistent
-	defer t.mutex.Unlock() // Release lock when we're done
+		t._cleanRoot()
-	t.cleanRoot()
+		t._cleanDropped()
-	t.cleanDropped()
+	})
 }
 
 // Updates the root periodically if it is ourself, or promotes ourself to root if we're better than the current root or if the current root has timed out.
-func (t *switchTable) cleanRoot() {
+func (t *switchTable) _cleanRoot() {
 	// TODO rethink how this is done?...
 	// Get rid of the root if it looks like its timed out
 	now := time.Now()
@@ -256,58 +227,58 @@ func (t *switchTable) cleanRoot() {
 		t.time = now
 		if t.data.locator.root != t.key {
 			t.data.seq++
-			t.updater.Store(&sync.Once{})
+			defer t.core.router.reset(nil)
-			t.core.router.reset(nil)
 		}
 		t.data.locator = switchLocator{root: t.key, tstamp: now.Unix()}
+		t._updateTable() // updates base copy of switch msg in lookupTable
 		t.core.peers.sendSwitchMsgs(t)
 	}
 }
 
 // Blocks and, if possible, unparents a peer
-func (t *switchTable) blockPeer(port switchPort) {
+func (t *switchTable) blockPeer(from phony.Actor, port switchPort) {
-	t.mutex.Lock()
+	t.Act(from, func() {
-	defer t.mutex.Unlock()
+		peer, isIn := t.data.peers[port]
-	peer, isIn := t.data.peers[port]
+		if !isIn {
-	if !isIn {
+			return
-		return
-	}
-	peer.blocked = true
-	t.data.peers[port] = peer
-	if port != t.parent {
-		return
-	}
-	t.parent = 0
-	for _, info := range t.data.peers {
-		if info.port == port {
-			continue
 		}
-		t.unlockedHandleMsg(&info.msg, info.port, true)
+		peer.blocked = true
-	}
+		t.data.peers[port] = peer
-	t.unlockedHandleMsg(&peer.msg, peer.port, true)
+		if port != t.parent {
+			return
+		}
+		t.parent = 0
+		for _, info := range t.data.peers {
+			if info.port == port {
+				continue
+			}
+			t._handleMsg(&info.msg, info.port, true)
+		}
+		t._handleMsg(&peer.msg, peer.port, true)
+	})
 }
 
 // Removes a peer.
 // Must be called by the router actor with a lambda that calls this.
 // If the removed peer was this node's parent, it immediately tries to find a new parent.
-func (t *switchTable) forgetPeer(port switchPort) {
+func (t *switchTable) forgetPeer(from phony.Actor, port switchPort) {
-	t.mutex.Lock()
+	t.Act(from, func() {
-	defer t.mutex.Unlock()
+		delete(t.data.peers, port)
-	delete(t.data.peers, port)
+		defer t._updateTable()
-	t.updater.Store(&sync.Once{})
+		if port != t.parent {
-	if port != t.parent {
+			return
-		return
+		}
-	}
+		t.parent = 0
-	t.parent = 0
+		for _, info := range t.data.peers {
-	for _, info := range t.data.peers {
+			t._handleMsg(&info.msg, info.port, true)
-		t.unlockedHandleMsg(&info.msg, info.port, true)
+		}
-	}
+	})
 }
 
 // Dropped is a list of roots that are better than the current root, but stopped sending new timestamps.
 // If we switch to a new root, and that root is better than an old root that previously timed out, then we can clean up the old dropped root infos.
 // This function is called periodically to do that cleanup.
-func (t *switchTable) cleanDropped() {
+func (t *switchTable) _cleanDropped() {
 	// TODO? only call this after root changes, not periodically
 	for root := range t.drop {
 		if !firstIsBetter(&root, &t.data.locator.root) {
@@ -333,9 +304,7 @@ type switchMsgHop struct {
 }
 
 // This returns a *switchMsg to a copy of this node's current switchMsg, which can safely have additional information appended to Hops and sent to a peer.
-func (t *switchTable) getMsg() *switchMsg {
+func (t *switchTable) _getMsg() *switchMsg {
-	t.mutex.RLock()
-	defer t.mutex.RUnlock()
 	if t.parent == 0 {
 		return &switchMsg{Root: t.key, TStamp: t.data.locator.tstamp}
 	} else if parent, isIn := t.data.peers[t.parent]; isIn {
@@ -347,14 +316,18 @@ func (t *switchTable) getMsg() *switchMsg {
 	}
 }
 
+func (t *lookupTable) getMsg() *switchMsg {
+	msg := t._msg
+	msg.Hops = append([]switchMsgHop(nil), t._msg.Hops...)
+	return &msg
+}
+
 // This function checks that the root information in a switchMsg is OK.
 // In particular, that the root is better, or else the same as the current root but with a good timestamp, and that this root+timestamp haven't been dropped due to timeout.
-func (t *switchTable) checkRoot(msg *switchMsg) bool {
+func (t *switchTable) _checkRoot(msg *switchMsg) bool {
 	// returns false if it's a dropped root, not a better root, or has an older timestamp
 	// returns true otherwise
 	// used elsewhere to keep inserting peers into the dht only if root info is OK
-	t.mutex.RLock()
-	defer t.mutex.RUnlock()
 	dropTstamp, isIn := t.drop[msg.Root]
 	switch {
 	case isIn && dropTstamp >= msg.TStamp:
@@ -370,20 +343,13 @@ func (t *switchTable) checkRoot(msg *switchMsg) bool {
 	}
 }
 
-// This is a mutexed wrapper to unlockedHandleMsg, and is called by the peer structs in peers.go to pass a switchMsg for that peer into the switch.
-func (t *switchTable) handleMsg(msg *switchMsg, fromPort switchPort) {
-	t.mutex.Lock()
-	defer t.mutex.Unlock()
-	t.unlockedHandleMsg(msg, fromPort, false)
-}
-
 // This updates the switch with information about a peer.
 // Then the tricky part, it decides if it should update our own locator as a result.
 // That happens if this node is already our parent, or is advertising a better root, or is advertising a better path to the same root, etc...
 // There are a lot of very delicate order sensitive checks here, so its' best to just read the code if you need to understand what it's doing.
 // It's very important to not change the order of the statements in the case function unless you're absolutely sure that it's safe, including safe if used alongside nodes that used the previous order.
 // Set the third arg to true if you're reprocessing an old message, e.g. to find a new parent after one disconnects, to avoid updating some timing related things.
-func (t *switchTable) unlockedHandleMsg(msg *switchMsg, fromPort switchPort, reprocessing bool) {
+func (t *switchTable) _handleMsg(msg *switchMsg, fromPort switchPort, reprocessing bool) {
 	// TODO directly use a switchMsg instead of switchMessage + sigs
 	now := time.Now()
 	// Set up the sender peerInfo
@@ -506,10 +472,10 @@ func (t *switchTable) unlockedHandleMsg(msg *switchMsg, fromPort switchPort, rep
 			if peer.port == sender.port {
 				continue
 			}
-			t.unlockedHandleMsg(&peer.msg, peer.port, true)
+			t._handleMsg(&peer.msg, peer.port, true)
 		}
 		// Process the sender last, to avoid keeping them as a parent if at all possible.
-		t.unlockedHandleMsg(&sender.msg, sender.port, true)
+		t._handleMsg(&sender.msg, sender.port, true)
 	case now.Sub(t.time) < switch_throttle:
 		// We've already gotten an update from this root recently, so ignore this one to avoid flooding.
 	case sender.locator.tstamp > t.data.locator.tstamp:
@@ -527,10 +493,10 @@ func (t *switchTable) unlockedHandleMsg(msg *switchMsg, fromPort switchPort, rep
 		}
 		t.data.locator = sender.locator
 		t.parent = sender.port
-		t.core.peers.sendSwitchMsgs(t)
+		defer t.core.peers.sendSwitchMsgs(t)
 	}
 	if true || doUpdate {
-		t.updater.Store(&sync.Once{})
+		defer t._updateTable()
 	}
 	return
 }
@@ -540,7 +506,7 @@ func (t *switchTable) unlockedHandleMsg(msg *switchMsg, fromPort switchPort, rep
 // The rest of these are related to the switch worker
 
 // This is called via a sync.Once to update the atomically readable subset of switch information that gets used for routing decisions.
-func (t *switchTable) updateTable() {
+func (t *switchTable) _updateTable() {
 	// WARNING this should only be called from within t.data.updater.Do()
 	//  It relies on the sync.Once for synchronization with messages and lookups
 	// TODO use a pre-computed faster lookup table
@@ -549,8 +515,6 @@ func (t *switchTable) updateTable() {
 	//  Each struct has stores the best port to forward to, and a next coord map
 	//  Move to struct, then iterate over coord maps until you dead end
 	//  The last port before the dead end should be the closest
-	t.mutex.RLock()
-	defer t.mutex.RUnlock()
 	newTable := lookupTable{
 		self:  t.data.locator.clone(),
 		elems: make(map[switchPort]tableElem, len(t.data.peers)),
@@ -568,13 +532,9 @@ func (t *switchTable) updateTable() {
 			time:    pinfo.time,
 		}
 	}
-	t.table.Store(newTable)
+	newTable._msg = *t._getMsg()
-}
+	t.core.peers.updateTables(t, &newTable)
-
+	t.core.router.updateTable(t, &newTable)
-// Returns a copy of the atomically-updated table used for switch lookups
-func (t *switchTable) getTable() lookupTable {
-	t.updater.Load().(*sync.Once).Do(t.updateTable)
-	return t.table.Load().(lookupTable)
 }
 
 // Starts the switch worker
@@ -584,307 +544,39 @@ func (t *switchTable) start() error {
 	return nil
 }
 
-type closerInfo struct {
+// Find the best port to forward to for a given set of coords
-	elem tableElem
+func (t *lookupTable) lookup(coords []byte) switchPort {
-	dist int
+	var bestPort switchPort
-}
+	myDist := t.self.dist(coords)
-
+	bestDist := myDist
-// Return a map of ports onto distance, keeping only ports closer to the destination than this node
+	var bestElem tableElem
-// If the map is empty (or nil), then no peer is closer
+	for _, info := range t.elems {
-func (t *switchTable) getCloser(dest []byte) []closerInfo {
+		dist := info.locator.dist(coords)
-	table := t.getTable()
+		if dist >= myDist {
-	myDist := table.self.dist(dest)
-	if myDist == 0 {
-		// Skip the iteration step if it's impossible to be closer
-		return nil
-	}
-	t.queues.closer = t.queues.closer[:0]
-	for _, info := range table.elems {
-		dist := info.locator.dist(dest)
-		if dist < myDist {
-			t.queues.closer = append(t.queues.closer, closerInfo{info, dist})
-		}
-	}
-	return t.queues.closer
-}
-
-// Returns true if the peer is closer to the destination than ourself
-func (t *switchTable) portIsCloser(dest []byte, port switchPort) bool {
-	table := t.getTable()
-	if info, isIn := table.elems[port]; isIn {
-		theirDist := info.locator.dist(dest)
-		myDist := table.self.dist(dest)
-		return theirDist < myDist
-	} else {
-		return false
-	}
-}
-
-// Get the coords of a packet without decoding
-func switch_getPacketCoords(packet []byte) []byte {
-	_, pTypeLen := wire_decode_uint64(packet)
-	coords, _ := wire_decode_coords(packet[pTypeLen:])
-	return coords
-}
-
-// Returns a unique string for each stream of traffic
-// Equal to coords
-// The sender may append arbitrary info to the end of coords (as long as it's begins with a 0x00) to designate separate traffic streams
-// Currently, it's the IPv6 next header type and the first 2 uint16 of the next header
-// This is equivalent to the TCP/UDP protocol numbers and the source / dest ports
-// TODO figure out if something else would make more sense (other transport protocols?)
-func switch_getPacketStreamID(packet []byte) string {
-	return string(switch_getPacketCoords(packet))
-}
-
-// Returns the flowlabel from a given set of coords
-func switch_getFlowLabelFromCoords(in []byte) []byte {
-	for i, v := range in {
-		if v == 0 {
-			return in[i+1:]
-		}
-	}
-	return []byte{}
-}
-
-// Find the best port for a given set of coords
-func (t *switchTable) bestPortForCoords(coords []byte) switchPort {
-	table := t.getTable()
-	var best switchPort
-	bestDist := table.self.dist(coords)
-	for to, elem := range table.elems {
-		dist := elem.locator.dist(coords)
-		if !(dist < bestDist) {
 			continue
 		}
-		best = to
-		bestDist = dist
-	}
-	return best
-}
-
-// Handle an incoming packet
-// Either send it to ourself, or to the first idle peer that's free
-// Returns true if the packet has been handled somehow, false if it should be queued
-func (t *switchTable) _handleIn(packet []byte, idle map[switchPort]struct{}, sending map[switchPort]struct{}) bool {
-	coords := switch_getPacketCoords(packet)
-	closer := t.getCloser(coords)
-	if len(closer) == 0 {
-		// TODO? call the router directly, and remove the whole concept of a self peer?
-		self := t.core.peers.getPorts()[0]
-		self.sendPacketsFrom(t, [][]byte{packet})
-		return true
-	}
-	var best *closerInfo
-	ports := t.core.peers.getPorts()
-	for _, cinfo := range closer {
-		to := ports[cinfo.elem.port]
-		//_, isIdle := idle[cinfo.elem.port]
-		_, isSending := sending[cinfo.elem.port]
 		var update bool
 		switch {
-		case to == nil:
+		case dist < bestDist:
-			// no port was found, ignore it
+			// Closer to destination
-		case isSending:
-			// the port is busy, ignore it
-		case best == nil:
-			// this is the first idle port we've found, so select it until we find a
-			// better candidate port to use instead
 			update = true
-		case cinfo.dist < best.dist:
+		case dist > bestDist:
-			// the port takes a shorter path/is more direct than our current
+			// Further from destination
-			// candidate, so select that instead
+		case info.locator.tstamp > bestElem.locator.tstamp:
+			// Newer root update
 			update = true
-		case cinfo.dist > best.dist:
+		case info.locator.tstamp < bestElem.locator.tstamp:
-			// the port takes a longer path/is less direct than our current candidate,
+			// Older root update
-			// ignore it
+		case info.time.Before(bestElem.time):
-		case cinfo.elem.locator.tstamp > best.elem.locator.tstamp:
+			// Received root update via this peer sooner
-			// has a newer tstamp from the root, so presumably a better path
-			update = true
-		case cinfo.elem.locator.tstamp < best.elem.locator.tstamp:
-			// has a n older tstamp, so presumably a worse path
-		case cinfo.elem.time.Before(best.elem.time):
-			// same tstamp, but got it earlier, so presumably a better path
-			//t.core.log.Println("DEBUG new best:", best.elem.time, cinfo.elem.time)
 			update = true
 		default:
-			// the search for a port has finished
 		}
 		if update {
-			b := cinfo // because cinfo gets mutated by the iteration
+			bestPort = info.port
-			best = &b
+			bestDist = dist
+			bestElem = info
 		}
 	}
-	if best != nil {
+	return bestPort
-		if _, isIdle := idle[best.elem.port]; isIdle {
-			delete(idle, best.elem.port)
-			ports[best.elem.port].sendPacketsFrom(t, [][]byte{packet})
-			return true
-		}
-	}
-	// Didn't find anyone idle to send it to
-	return false
-}
-
-// Info about a buffered packet
-type switch_packetInfo struct {
-	bytes []byte
-	time  time.Time // Timestamp of when the packet arrived
-}
-
-// Used to keep track of buffered packets
-type switch_buffer struct {
-	packets []switch_packetInfo // Currently buffered packets, which may be dropped if it grows too large
-	size    uint64              // Total queue size in bytes
-}
-
-type switch_buffers struct {
-	totalMaxSize uint64
-	bufs         map[string]switch_buffer // Buffers indexed by StreamID
-	size         uint64                   // Total size of all buffers, in bytes
-	maxbufs      int
-	maxsize      uint64
-	closer       []closerInfo // Scratch space
-}
-
-func (b *switch_buffers) _cleanup(t *switchTable) {
-	for streamID, buf := range b.bufs {
-		// Remove queues for which we have no next hop
-		packet := buf.packets[0]
-		coords := switch_getPacketCoords(packet.bytes)
-		if len(t.getCloser(coords)) == 0 {
-			for _, packet := range buf.packets {
-				util.PutBytes(packet.bytes)
-			}
-			b.size -= buf.size
-			delete(b.bufs, streamID)
-		}
-	}
-
-	for b.size > b.totalMaxSize {
-		// Drop a random queue
-		target := rand.Uint64() % b.size
-		var size uint64 // running total
-		for streamID, buf := range b.bufs {
-			size += buf.size
-			if size < target {
-				continue
-			}
-			var packet switch_packetInfo
-			packet, buf.packets = buf.packets[0], buf.packets[1:]
-			buf.size -= uint64(len(packet.bytes))
-			b.size -= uint64(len(packet.bytes))
-			util.PutBytes(packet.bytes)
-			if len(buf.packets) == 0 {
-				delete(b.bufs, streamID)
-			} else {
-				// Need to update the map, since buf was retrieved by value
-				b.bufs[streamID] = buf
-			}
-			break
-		}
-	}
-}
-
-// Handles incoming idle notifications
-// Loops over packets and sends the newest one that's OK for this peer to send
-// Returns true if the peer is no longer idle, false if it should be added to the idle list
-func (t *switchTable) _handleIdle(port switchPort) bool {
-	// TODO? only send packets for which this is the best next hop that isn't currently blocked sending
-	to := t.core.peers.getPorts()[port]
-	if to == nil {
-		return true
-	}
-	var packets [][]byte
-	var psize int
-	t.queues._cleanup(t)
-	now := time.Now()
-	for psize < 65535 {
-		var best *string
-		var bestPriority float64
-		for streamID, buf := range t.queues.bufs {
-			// Filter over the streams that this node is closer to
-			// Keep the one with the smallest queue
-			packet := buf.packets[0]
-			coords := switch_getPacketCoords(packet.bytes)
-			priority := float64(now.Sub(packet.time)) / float64(buf.size)
-			if priority >= bestPriority && t.portIsCloser(coords, port) {
-				b := streamID // copy since streamID is mutated in the loop
-				best = &b
-				bestPriority = priority
-			}
-		}
-		if best != nil {
-			buf := t.queues.bufs[*best]
-			var packet switch_packetInfo
-			// TODO decide if this should be LIFO or FIFO
-			packet, buf.packets = buf.packets[0], buf.packets[1:]
-			buf.size -= uint64(len(packet.bytes))
-			t.queues.size -= uint64(len(packet.bytes))
-			if len(buf.packets) == 0 {
-				delete(t.queues.bufs, *best)
-			} else {
-				// Need to update the map, since buf was retrieved by value
-				t.queues.bufs[*best] = buf
-			}
-			packets = append(packets, packet.bytes)
-			psize += len(packet.bytes)
-		} else {
-			// Finished finding packets
-			break
-		}
-	}
-	if len(packets) > 0 {
-		to.sendPacketsFrom(t, packets)
-		return true
-	}
-	return false
-}
-
-func (t *switchTable) packetInFrom(from phony.Actor, bytes []byte) {
-	t.Act(from, func() {
-		t._packetIn(bytes)
-	})
-}
-
-func (t *switchTable) _packetIn(bytes []byte) {
-	// Try to send it somewhere (or drop it if it's corrupt or at a dead end)
-	if !t._handleIn(bytes, t.idle, t.sending) {
-		// There's nobody free to take it right now, so queue it for later
-		packet := switch_packetInfo{bytes, time.Now()}
-		streamID := switch_getPacketStreamID(packet.bytes)
-		buf, bufExists := t.queues.bufs[streamID]
-		buf.packets = append(buf.packets, packet)
-		buf.size += uint64(len(packet.bytes))
-		t.queues.size += uint64(len(packet.bytes))
-		// Keep a track of the max total queue size
-		if t.queues.size > t.queues.maxsize {
-			t.queues.maxsize = t.queues.size
-		}
-		t.queues.bufs[streamID] = buf
-		if !bufExists {
-			// Keep a track of the max total queue count. Only recalculate this
-			// when the queue is new because otherwise repeating len(dict) might
-			// cause unnecessary processing overhead
-			if len(t.queues.bufs) > t.queues.maxbufs {
-				t.queues.maxbufs = len(t.queues.bufs)
-			}
-		}
-		t.queues._cleanup(t)
-	}
-}
-
-func (t *switchTable) _idleIn(port switchPort) {
-	// Try to find something to send to this peer
-	delete(t.sending, port)
-	if !t._handleIdle(port) {
-		// Didn't find anything ready to send yet, so stay idle
-		t.idle[port] = struct{}{}
-	}
-}
-
-func (t *switchTable) _sendingIn(port switchPort) {
-	if _, isIn := t.idle[port]; !isIn {
-		t.sending[port] = struct{}{}
-	}
 }