Merge pull request #318 from yggdrasil-network/link

Implement link interface

contrib/ansible/genkeys.go

@@ -35,22 +35,22 @@ func main() {
 	}
 
 	var encryptionKeys []keySet
-	for i := 0; i < *numHosts + 1; i++ {
+	for i := 0; i < *numHosts+1; i++ {
 		encryptionKeys = append(encryptionKeys, newBoxKey())
 	}
 	encryptionKeys = sortKeySetArray(encryptionKeys)
-	for i := 0; i < *keyTries - *numHosts - 1; i++ {
+	for i := 0; i < *keyTries-*numHosts-1; i++ {
-		encryptionKeys[0] = newBoxKey();
+		encryptionKeys[0] = newBoxKey()
 		encryptionKeys = bubbleUpTo(encryptionKeys, 0)
 	}
 
 	var signatureKeys []keySet
-	for i := 0; i < *numHosts + 1; i++ {
+	for i := 0; i < *numHosts+1; i++ {
 		signatureKeys = append(signatureKeys, newSigKey())
 	}
 	signatureKeys = sortKeySetArray(signatureKeys)
-	for i := 0; i < *keyTries - *numHosts - 1; i++ {
+	for i := 0; i < *keyTries-*numHosts-1; i++ {
-		signatureKeys[0] = newSigKey();
+		signatureKeys[0] = newSigKey()
 		signatureKeys = bubbleUpTo(signatureKeys, 0)
 	}
 
@@ -112,11 +112,11 @@ func sortKeySetArray(sets []keySet) []keySet {
 }
 
 func bubbleUpTo(sets []keySet, num int) []keySet {
-	for i := 0; i < len(sets) - num - 1; i++ {
+	for i := 0; i < len(sets)-num-1; i++ {
-		if isBetter(sets[i + 1].id, sets[i].id) {
+		if isBetter(sets[i+1].id, sets[i].id) {
 			var tmp = sets[i]
-			sets[i] = sets[i + 1]
+			sets[i] = sets[i+1]
-			sets[i + 1] = tmp
+			sets[i+1] = tmp
 		} else {
 			break
 		}

go.mod

@@ -2,10 +2,10 @@ module github.com/yggdrasil-network/yggdrasil-go
 
 require (
 	github.com/docker/libcontainer v2.2.1+incompatible
+	github.com/gologme/log v0.0.0-20181207131047-4e5d8ccb38e8
 	github.com/hjson/hjson-go v0.0.0-20181010104306-a25ecf6bd222
 	github.com/kardianos/minwinsvc v0.0.0-20151122163309-cad6b2b879b0
 	github.com/mitchellh/mapstructure v1.1.2
-	github.com/gologme/log v0.0.0-20181207131047-4e5d8ccb38e8
 	github.com/songgao/packets v0.0.0-20160404182456-549a10cd4091
 	github.com/yggdrasil-network/water v0.0.0-20180615095340-f732c88f34ae
 	golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9

go.sum

@@ -1,5 +1,7 @@
 github.com/docker/libcontainer v2.2.1+incompatible h1:++SbbkCw+X8vAd4j2gOCzZ2Nn7s2xFALTf7LZKmM1/0=
 github.com/docker/libcontainer v2.2.1+incompatible/go.mod h1:osvj61pYsqhNCMLGX31xr7klUBhHb/ZBuXS0o1Fvwbw=
+github.com/gologme/log v0.0.0-20181207131047-4e5d8ccb38e8 h1:WD8iJ37bRNwvETMfVTusVSAi0WdXTpfNVGY2aHycNKY=
+github.com/gologme/log v0.0.0-20181207131047-4e5d8ccb38e8/go.mod h1:gq31gQ8wEHkR+WekdWsqDuf8pXTUZA9BnnzTuPz1Y9U=
 github.com/hjson/hjson-go v0.0.0-20181010104306-a25ecf6bd222 h1:xmvkbxXDeN1ffWq8kvrhyqVYAO2aXuRBsbpxVTR+JyU=
 github.com/hjson/hjson-go v0.0.0-20181010104306-a25ecf6bd222/go.mod h1:qsetwF8NlsTsOTwZTApNlTCerV+b2GjYRRcIk4JMFio=
 github.com/kardianos/minwinsvc v0.0.0-20151122163309-cad6b2b879b0 h1:YnZmFjg0Nvk8851WTVWlqMC1ecJH07Ctz+Ezxx4u54g=
@@ -18,5 +20,3 @@ golang.org/x/sys v0.0.0-20181206074257-70b957f3b65e h1:njOxP/wVblhCLIUhjHXf6X+dz
 golang.org/x/sys v0.0.0-20181206074257-70b957f3b65e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-github.com/gologme/log v0.0.0-20181207131047-4e5d8ccb38e8 h1:WD8iJ37bRNwvETMfVTusVSAi0WdXTpfNVGY2aHycNKY=
-github.com/gologme/log v0.0.0-20181207131047-4e5d8ccb38e8/go.mod h1:gq31gQ8wEHkR+WekdWsqDuf8pXTUZA9BnnzTuPz1Y9U=

src/util/util.go

@@ -3,6 +3,7 @@ package util
 // These are misc. utility functions that didn't really fit anywhere else
 
 import "runtime"
+import "time"
 
 // A wrapper around runtime.Gosched() so it doesn't need to be imported elsewhere.
 func Yield() {
@@ -44,3 +45,14 @@ func PutBytes(bs []byte) {
 	default:
 	}
 }
+
+// This is a workaround to go's broken timer implementation
+func TimerStop(t *time.Timer) bool {
+	if !t.Stop() {
+		select {
+		case <-t.C:
+		default:
+		}
+	}
+	return true
+}

src/yggdrasil/awdl.go

@@ -2,147 +2,97 @@ package yggdrasil
 
 import (
 	"errors"
-	"fmt"
+	"io"
 	"sync"
-	"sync/atomic"
-	"time"
-
-	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
-	"github.com/yggdrasil-network/yggdrasil-go/src/util"
 )
 
 type awdl struct {
-	core       *Core
+	link       *link
 	mutex      sync.RWMutex // protects interfaces below
 	interfaces map[string]*awdlInterface
 }
 
 type awdlInterface struct {
-	awdl     *awdl
+	linkif *linkInterface
-	fromAWDL chan []byte
+	rwc    awdlReadWriteCloser
-	toAWDL   chan []byte
+	peer   *peer
-	shutdown chan bool
+	stream stream
-	peer     *peer
 }
 
-func (l *awdl) init(c *Core) error {
+type awdlReadWriteCloser struct {
-	l.core = c
+	fromAWDL chan []byte
-	l.mutex.Lock()
+	toAWDL   chan []byte
-	l.interfaces = make(map[string]*awdlInterface)
+}
-	l.mutex.Unlock()
+
+func (c awdlReadWriteCloser) Read(p []byte) (n int, err error) {
+	if packet, ok := <-c.fromAWDL; ok {
+		n = copy(p, packet)
+		return n, nil
+	}
+	return 0, io.EOF
+}
+
+func (c awdlReadWriteCloser) Write(p []byte) (n int, err error) {
+	var pc []byte
+	pc = append(pc, p...)
+	c.toAWDL <- pc
+	return len(pc), nil
+}
+
+func (c awdlReadWriteCloser) Close() error {
+	close(c.fromAWDL)
+	close(c.toAWDL)
+	return nil
+}
+
+func (a *awdl) init(l *link) error {
+	a.link = l
+	a.mutex.Lock()
+	a.interfaces = make(map[string]*awdlInterface)
+	a.mutex.Unlock()
 
 	return nil
 }
 
-func (l *awdl) create(fromAWDL chan []byte, toAWDL chan []byte /*boxPubKey *crypto.BoxPubKey, sigPubKey *crypto.SigPubKey*/, name string) (*awdlInterface, error) {
+func (a *awdl) create(name, local, remote string, incoming bool) (*awdlInterface, error) {
+	rwc := awdlReadWriteCloser{
+		fromAWDL: make(chan []byte, 1),
+		toAWDL:   make(chan []byte, 1),
+	}
+	s := stream{}
+	s.init(rwc)
+	linkif, err := a.link.create(&s, name, "awdl", local, remote, incoming, true)
+	if err != nil {
+		return nil, err
+	}
 	intf := awdlInterface{
-		awdl:     l,
+		linkif: linkif,
-		fromAWDL: fromAWDL,
+		rwc:    rwc,
-		toAWDL:   toAWDL,
-		shutdown: make(chan bool),
 	}
-	l.mutex.Lock()
+	a.mutex.Lock()
-	l.interfaces[name] = &intf
+	a.interfaces[name] = &intf
-	l.mutex.Unlock()
+	a.mutex.Unlock()
-	myLinkPub, myLinkPriv := crypto.NewBoxKeys()
+	go intf.linkif.handler()
-	meta := version_getBaseMetadata()
+	return &intf, nil
-	meta.box = l.core.boxPub
-	meta.sig = l.core.sigPub
-	meta.link = *myLinkPub
-	metaBytes := meta.encode()
-	l.core.log.Traceln("toAWDL <- metaBytes")
-	toAWDL <- metaBytes
-	l.core.log.Traceln("metaBytes = <-fromAWDL")
-	metaBytes = <-fromAWDL
-	l.core.log.Traceln("version_metadata{}")
-	meta = version_metadata{}
-	if !meta.decode(metaBytes) || !meta.check() {
-		return nil, errors.New("Metadata decode failure")
-	}
-	l.core.log.Traceln("version_getBaseMetadata{}")
-	base := version_getBaseMetadata()
-	if meta.ver > base.ver || meta.ver == base.ver && meta.minorVer > base.minorVer {
-		return nil, errors.New("Failed to connect to node: " + name + " version: " + fmt.Sprintf("%d.%d", meta.ver, meta.minorVer))
-	}
-	l.core.log.Traceln("crypto.GetSharedKey")
-	shared := crypto.GetSharedKey(myLinkPriv, &meta.link)
-	//shared := crypto.GetSharedKey(&l.core.boxPriv, boxPubKey)
-	l.core.log.Traceln("l.core.peers.newPeer")
-	intf.peer = l.core.peers.newPeer(&meta.box, &meta.sig, shared, name)
-	if intf.peer != nil {
-		intf.peer.linkOut = make(chan []byte, 1) // protocol traffic
-		intf.peer.out = func(msg []byte) {
-			defer func() { recover() }()
-			intf.toAWDL <- msg
-		} // called by peer.sendPacket()
-		l.core.switchTable.idleIn <- intf.peer.port // notify switch that we're idle
-		intf.peer.close = func() {
-			close(intf.fromAWDL)
-			close(intf.toAWDL)
-		}
-		go intf.handler()
-		go intf.peer.linkLoop()
-		return &intf, nil
-	}
-	delete(l.interfaces, name)
-	return nil, errors.New("l.core.peers.newPeer failed")
 }
 
-func (l *awdl) getInterface(identity string) *awdlInterface {
+func (a *awdl) getInterface(identity string) *awdlInterface {
-	l.mutex.RLock()
+	a.mutex.RLock()
-	defer l.mutex.RUnlock()
+	defer a.mutex.RUnlock()
-	if intf, ok := l.interfaces[identity]; ok {
+	if intf, ok := a.interfaces[identity]; ok {
 		return intf
 	}
 	return nil
 }
 
-func (l *awdl) shutdown(identity string) error {
+func (a *awdl) shutdown(identity string) error {
-	if intf, ok := l.interfaces[identity]; ok {
+	if intf, ok := a.interfaces[identity]; ok {
-		intf.shutdown <- true
+		close(intf.linkif.closed)
-		l.core.peers.removePeer(intf.peer.port)
+		intf.rwc.Close()
-		l.mutex.Lock()
+		a.mutex.Lock()
-		delete(l.interfaces, identity)
+		delete(a.interfaces, identity)
-		l.mutex.Unlock()
+		a.mutex.Unlock()
 		return nil
-	} else {
-		return errors.New(fmt.Sprintf("Interface '%s' doesn't exist or already shutdown", identity))
-	}
-}
-
-func (ai *awdlInterface) handler() {
-	send := func(msg []byte) {
-		ai.toAWDL <- msg
-		atomic.AddUint64(&ai.peer.bytesSent, uint64(len(msg)))
-		util.PutBytes(msg)
-	}
-	for {
-		timerInterval := tcp_ping_interval
-		timer := time.NewTimer(timerInterval)
-		defer timer.Stop()
-		select {
-		case p := <-ai.peer.linkOut:
-			send(p)
-			continue
-		default:
-		}
-		timer.Stop()
-		select {
-		case <-timer.C:
-		default:
-		}
-		timer.Reset(timerInterval)
-		select {
-		case _ = <-timer.C:
-			send([]byte{})
-		case p := <-ai.peer.linkOut:
-			send(p)
-			continue
-		case r := <-ai.fromAWDL:
-			ai.peer.handlePacket(r)
-			ai.awdl.core.switchTable.idleIn <- ai.peer.port
-		case <-ai.shutdown:
-			return
-		}
 	}
+	return errors.New("Interface not found or already closed")
 }

src/yggdrasil/core.go

@@ -45,7 +45,7 @@ type Core struct {
 	searches    searches
 	multicast   multicast
 	tcp         tcpInterface
-	awdl        awdl
+	link        link
 	log         *log.Logger
 }
 
@@ -199,8 +199,8 @@ func (c *Core) Start(nc *config.NodeConfig, log *log.Logger) error {
 		return err
 	}
 
-	if err := c.awdl.init(c); err != nil {
+	if err := c.link.init(c); err != nil {
-		c.log.Errorln("Failed to start AWDL interface")
+		c.log.Errorln("Failed to start link interfaces")
 		return err
 	}
 

src/yggdrasil/debug.go

@@ -97,9 +97,7 @@ func (c *Core) DEBUG_getPeers() *peers {
 }
 
 func (ps *peers) DEBUG_newPeer(box crypto.BoxPubKey, sig crypto.SigPubKey, link crypto.BoxSharedKey) *peer {
-	//in <-chan []byte,
+	return ps.newPeer(&box, &sig, &link, "(simulator)", nil)
-	//out chan<- []byte) *peer {
-	return ps.newPeer(&box, &sig, &link, "(simulator)") //, in, out)
 }
 
 /*

src/yggdrasil/link.go

@@ -0,0 +1,311 @@
+package yggdrasil
+
+import (
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"net"
+	"strings"
+	"sync"
+	//"sync/atomic"
+	"time"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/address"
+	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
+	"github.com/yggdrasil-network/yggdrasil-go/src/util"
+)
+
+type link struct {
+	core       *Core
+	mutex      sync.RWMutex // protects interfaces below
+	interfaces map[linkInfo]*linkInterface
+	awdl       awdl // AWDL interface support
+	// TODO timeout (to remove from switch), read from config.ReadTimeout
+}
+
+type linkInfo struct {
+	box      crypto.BoxPubKey // Their encryption key
+	sig      crypto.SigPubKey // Their signing key
+	linkType string           // Type of link, e.g. TCP, AWDL
+	local    string           // Local name or address
+	remote   string           // Remote name or address
+}
+
+type linkInterfaceMsgIO interface {
+	readMsg() ([]byte, error)
+	writeMsg([]byte) (int, error)
+	close() error
+	// These are temporary workarounds to stream semantics
+	_sendMetaBytes([]byte) error
+	_recvMetaBytes() ([]byte, error)
+}
+
+type linkInterface struct {
+	name     string
+	link     *link
+	peer     *peer
+	msgIO    linkInterfaceMsgIO
+	info     linkInfo
+	incoming bool
+	force    bool
+	closed   chan struct{}
+}
+
+func (l *link) init(c *Core) error {
+	l.core = c
+	l.mutex.Lock()
+	l.interfaces = make(map[linkInfo]*linkInterface)
+	l.mutex.Unlock()
+
+	if err := l.awdl.init(l); err != nil {
+		l.core.log.Errorln("Failed to start AWDL interface")
+		return err
+	}
+
+	return nil
+}
+
+func (l *link) create(msgIO linkInterfaceMsgIO, name, linkType, local, remote string, incoming, force bool) (*linkInterface, error) {
+	// Technically anything unique would work for names, but lets pick something human readable, just for debugging
+	intf := linkInterface{
+		name:  name,
+		link:  l,
+		msgIO: msgIO,
+		info: linkInfo{
+			linkType: linkType,
+			local:    local,
+			remote:   remote,
+		},
+		incoming: incoming,
+		force:    force,
+	}
+	return &intf, nil
+}
+
+func (intf *linkInterface) handler() error {
+	// TODO split some of this into shorter functions, so it's easier to read, and for the FIXME duplicate peer issue mentioned later
+	myLinkPub, myLinkPriv := crypto.NewBoxKeys()
+	meta := version_getBaseMetadata()
+	meta.box = intf.link.core.boxPub
+	meta.sig = intf.link.core.sigPub
+	meta.link = *myLinkPub
+	metaBytes := meta.encode()
+	// TODO timeouts on send/recv (goroutine for send/recv, channel select w/ timer)
+	err := intf.msgIO._sendMetaBytes(metaBytes)
+	if err != nil {
+		return err
+	}
+	metaBytes, err = intf.msgIO._recvMetaBytes()
+	if err != nil {
+		return err
+	}
+	meta = version_metadata{}
+	if !meta.decode(metaBytes) || !meta.check() {
+		return errors.New("failed to decode metadata")
+	}
+	base := version_getBaseMetadata()
+	if meta.ver > base.ver || meta.ver == base.ver && meta.minorVer > base.minorVer {
+		intf.link.core.log.Errorln("Failed to connect to node: " + intf.name + " version: " + fmt.Sprintf("%d.%d", meta.ver, meta.minorVer))
+		return errors.New("failed to connect: wrong version")
+	}
+	// Check if we're authorized to connect to this key / IP
+	if !intf.force && !intf.link.core.peers.isAllowedEncryptionPublicKey(&meta.box) {
+		intf.link.core.log.Debugf("%s connection to %s forbidden: AllowedEncryptionPublicKeys does not contain key %s",
+			strings.ToUpper(intf.info.linkType), intf.info.remote, hex.EncodeToString(meta.box[:]))
+		intf.msgIO.close()
+		return nil
+	}
+	// Check if we already have a link to this node
+	intf.info.box = meta.box
+	intf.info.sig = meta.sig
+	intf.link.mutex.Lock()
+	if oldIntf, isIn := intf.link.interfaces[intf.info]; isIn {
+		intf.link.mutex.Unlock()
+		// FIXME we should really return an error and let the caller block instead
+		// That lets them do things like close connections on its own, avoid printing a connection message in the first place, etc.
+		intf.link.core.log.Debugln("DEBUG: found existing interface for", intf.name)
+		intf.msgIO.close()
+		<-oldIntf.closed
+		return nil
+	} else {
+		intf.closed = make(chan struct{})
+		intf.link.interfaces[intf.info] = intf
+		defer func() {
+			intf.link.mutex.Lock()
+			delete(intf.link.interfaces, intf.info)
+			intf.link.mutex.Unlock()
+			close(intf.closed)
+		}()
+		intf.link.core.log.Debugln("DEBUG: registered interface for", intf.name)
+	}
+	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.name, 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)
+	}()
+	// Finish setting up the peer struct
+	out := make(chan []byte, 1)
+	defer close(out)
+	intf.peer.out = func(msg []byte) {
+		defer func() { recover() }()
+		out <- msg
+	}
+	intf.peer.linkOut = make(chan []byte, 1)
+	themAddr := address.AddrForNodeID(crypto.GetNodeID(&intf.info.box))
+	themAddrString := net.IP(themAddr[:]).String()
+	themString := fmt.Sprintf("%s@%s", themAddrString, intf.info.remote)
+	intf.link.core.log.Infof("Connected %s: %s, source %s",
+		strings.ToUpper(intf.info.linkType), themString, intf.info.local)
+	defer intf.link.core.log.Infof("Disconnected %s: %s, source %s",
+		strings.ToUpper(intf.info.linkType), themString, intf.info.local)
+	// Start the link loop
+	go intf.peer.linkLoop()
+	// Start the writer
+	signalReady := make(chan struct{}, 1)
+	signalSent := make(chan bool, 1)
+	sendAck := make(chan struct{}, 1)
+	go func() {
+		defer close(signalReady)
+		defer close(signalSent)
+		interval := 4 * time.Second
+		tcpTimer := time.NewTimer(interval) // used for backwards compat with old tcp
+		defer util.TimerStop(tcpTimer)
+		send := func(bs []byte) {
+			intf.msgIO.writeMsg(bs)
+			select {
+			case signalSent <- len(bs) > 0:
+			default:
+			}
+		}
+		for {
+			// First try to send any link protocol traffic
+			select {
+			case msg := <-intf.peer.linkOut:
+				send(msg)
+				continue
+			default:
+			}
+			// No protocol traffic to send, so reset the timer
+			util.TimerStop(tcpTimer)
+			tcpTimer.Reset(interval)
+			// Now block until something is ready or the timer triggers keepalive traffic
+			select {
+			case <-tcpTimer.C:
+				intf.link.core.log.Debugf("Sending (legacy) keep-alive to %s: %s, source %s",
+					strings.ToUpper(intf.info.linkType), themString, intf.info.local)
+				send(nil)
+			case <-sendAck:
+				intf.link.core.log.Debugf("Sending ack to %s: %s, source %s",
+					strings.ToUpper(intf.info.linkType), themString, intf.info.local)
+				send(nil)
+			case msg := <-intf.peer.linkOut:
+				intf.msgIO.writeMsg(msg)
+			case msg, ok := <-out:
+				if !ok {
+					return
+				}
+				send(msg)
+				util.PutBytes(msg)
+				select {
+				case signalReady <- struct{}{}:
+				default:
+				}
+			}
+		}
+	}()
+	//intf.link.core.switchTable.idleIn <- intf.peer.port // notify switch that we're idle
+	// Used to enable/disable activity in the switch
+	signalAlive := make(chan bool, 1) // True = real packet, false = keep-alive
+	defer close(signalAlive)
+	go func() {
+		var isAlive bool
+		var isReady bool
+		var sendTimerRunning bool
+		var recvTimerRunning bool
+		recvTime := 6 * time.Second // TODO set to ReadTimeout from the config, reset if it gets changed
+		sendTime := time.Second
+		sendTimer := time.NewTimer(sendTime)
+		defer util.TimerStop(sendTimer)
+		recvTimer := time.NewTimer(recvTime)
+		defer util.TimerStop(recvTimer)
+		for {
+			select {
+			case gotMsg, ok := <-signalAlive:
+				if !ok {
+					return
+				}
+				if !isAlive {
+					isAlive = true
+					if !isReady {
+						// (Re-)enable in the switch
+						isReady = true
+						intf.link.core.switchTable.idleIn <- intf.peer.port
+					}
+				}
+				if gotMsg && !sendTimerRunning {
+					// We got a message
+					// Start a timer, if it expires then send a 0-sized ack to let them know we're alive
+					util.TimerStop(sendTimer)
+					sendTimer.Reset(sendTime)
+					sendTimerRunning = true
+				}
+			case sentMsg, ok := <-signalSent:
+				// Stop any running ack timer
+				if !ok {
+					return
+				}
+				util.TimerStop(sendTimer)
+				sendTimerRunning = false
+				if sentMsg && !recvTimerRunning {
+					// We sent a message
+					// Start a timer, if it expires and we haven't gotten any return traffic (including a 0-sized ack), then assume there's a problem
+					util.TimerStop(recvTimer)
+					recvTimer.Reset(recvTime)
+					recvTimerRunning = true
+				}
+			case _, ok := <-signalReady:
+				if !ok {
+					return
+				}
+				if !isAlive || !isReady {
+					// Disable in the switch
+					isReady = false
+				} else {
+					// Keep enabled in the switch
+					intf.link.core.switchTable.idleIn <- intf.peer.port
+				}
+			case <-sendTimer.C:
+				// We haven't sent anything, so signal a send of a 0 packet to let them know we're alive
+				select {
+				case sendAck <- struct{}{}:
+				default:
+				}
+			case <-recvTimer.C:
+				// We haven't received anything, so assume there's a problem and don't return this node to the switch until they start responding
+				isAlive = false
+			}
+		}
+	}()
+	// Run reader loop
+	for {
+		msg, err := intf.msgIO.readMsg()
+		if len(msg) > 0 {
+			intf.peer.handlePacket(msg)
+		}
+		if err != nil {
+			return err
+		}
+		select {
+		case signalAlive <- len(msg) > 0:
+		default:
+		}
+	}
+	////////////////////////////////////////////////////////////////////////////////
+	return nil
+}

src/yggdrasil/mobile.go

@@ -5,11 +5,11 @@ package yggdrasil
 import (
 	"encoding/hex"
 	"encoding/json"
-	"log"
 	"os"
-	"regexp"
 	"time"
 
+	"github.com/gologme/log"
+
 	hjson "github.com/hjson/hjson-go"
 	"github.com/mitchellh/mapstructure"
 	"github.com/yggdrasil-network/yggdrasil-go/src/config"
@@ -52,10 +52,6 @@ func (c *Core) StartAutoconfigure() error {
 	if hostname, err := os.Hostname(); err == nil {
 		nc.NodeInfo = map[string]interface{}{"name": hostname}
 	}
-	ifceExpr, err := regexp.Compile(".*")
-	if err == nil {
-		c.ifceExpr = append(c.ifceExpr, ifceExpr)
-	}
 	if err := c.Start(nc, logger); err != nil {
 		return err
 	}
@@ -77,13 +73,6 @@ func (c *Core) StartJSON(configjson []byte) error {
 		return err
 	}
 	nc.IfName = "dummy"
-	for _, ll := range nc.MulticastInterfaces {
-		ifceExpr, err := regexp.Compile(ll)
-		if err != nil {
-			panic(err)
-		}
-		c.AddMulticastInterfaceExpr(ifceExpr)
-	}
 	if err := c.Start(nc, logger); err != nil {
 		return err
 	}

src/yggdrasil/mobile_ios.go

@@ -29,39 +29,33 @@ func (nsl MobileLogger) Write(p []byte) (n int, err error) {
 	return len(p), nil
 }
 
-func (c *Core) AWDLCreateInterface(name string) error {
+func (c *Core) AWDLCreateInterface(name, local, remote string, incoming bool) error {
-	fromAWDL := make(chan []byte, 32)
+	if intf, err := c.link.awdl.create(name, local, remote, incoming); err != nil || intf == nil {
-	toAWDL := make(chan []byte, 32)
+		c.log.Println("c.link.awdl.create:", err)
-
-	if intf, err := c.awdl.create(fromAWDL, toAWDL, name); err == nil {
-		if intf != nil {
-			c.log.Println(err)
-			return err
-		} else {
-			c.log.Println("c.awdl.create didn't return an interface")
-			return errors.New("c.awdl.create didn't return an interface")
-		}
-	} else {
-		c.log.Println(err)
 		return err
 	}
+	return nil
 }
 
 func (c *Core) AWDLShutdownInterface(name string) error {
-	return c.awdl.shutdown(name)
+	return c.link.awdl.shutdown(name)
 }
 
 func (c *Core) AWDLRecvPacket(identity string) ([]byte, error) {
-	if intf := c.awdl.getInterface(identity); intf != nil {
+	if intf := c.link.awdl.getInterface(identity); intf != nil {
-		return <-intf.toAWDL, nil
+		read, ok := <-intf.rwc.toAWDL
+		if !ok {
+			return nil, errors.New("AWDLRecvPacket: channel closed")
+		}
+		return read, nil
 	}
 	return nil, errors.New("AWDLRecvPacket identity not known: " + identity)
 }
 
 func (c *Core) AWDLSendPacket(identity string, buf []byte) error {
 	packet := append(util.GetBytes(), buf[:]...)
-	if intf := c.awdl.getInterface(identity); intf != nil {
+	if intf := c.link.awdl.getInterface(identity); intf != nil {
-		intf.fromAWDL <- packet
+		intf.rwc.fromAWDL <- packet
 		return nil
 	}
 	return errors.New("AWDLSendPacket identity not known: " + identity)

src/yggdrasil/peer.go

@@ -113,7 +113,7 @@ type peer struct {
 }
 
 // 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, endpoint string) *peer {
+func (ps *peers) newPeer(box *crypto.BoxPubKey, sig *crypto.SigPubKey, linkShared *crypto.BoxSharedKey, endpoint string, closer func()) *peer {
 	now := time.Now()
 	p := peer{box: *box,
 		sig:        *sig,
@@ -123,6 +123,7 @@ func (ps *peers) newPeer(box *crypto.BoxPubKey, sig *crypto.SigPubKey, linkShare
 		firstSeen:  now,
 		doSend:     make(chan struct{}, 1),
 		dinfo:      make(chan *dhtInfo, 1),
+		close:      closer,
 		core:       ps.core}
 	ps.mutex.Lock()
 	defer ps.mutex.Unlock()
@@ -250,6 +251,7 @@ func (p *peer) handleTraffic(packet []byte, pTypeLen int) {
 func (p *peer) sendPacket(packet []byte) {
 	// Is there ever a case where something more complicated is needed?
 	// What if p.out blocks?
+	atomic.AddUint64(&p.bytesSent, uint64(len(packet)))
 	p.out(packet)
 }
 

src/yggdrasil/router.go

@@ -67,7 +67,7 @@ func (r *router) init(core *Core) {
 	r.addr = *address.AddrForNodeID(&r.core.dht.nodeID)
 	r.subnet = *address.SubnetForNodeID(&r.core.dht.nodeID)
 	in := make(chan []byte, 32) // TODO something better than this...
-	p := r.core.peers.newPeer(&r.core.boxPub, &r.core.sigPub, &crypto.BoxSharedKey{}, "(self)")
+	p := r.core.peers.newPeer(&r.core.boxPub, &r.core.sigPub, &crypto.BoxSharedKey{}, "(self)", nil)
 	p.out = func(packet []byte) {
 		// This is to make very sure it never blocks
 		select {

src/yggdrasil/stream.go

@@ -0,0 +1,141 @@
+package yggdrasil
+
+import (
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/util"
+)
+
+// Test that this matches the interface we expect
+var _ = linkInterfaceMsgIO(&stream{})
+
+type stream struct {
+	rwc         io.ReadWriteCloser
+	inputBuffer []byte // Incoming packet stream
+}
+
+func (s *stream) close() error {
+	return s.rwc.Close()
+}
+
+const streamMsgSize = 2048 + 65535
+
+var streamMsg = [...]byte{0xde, 0xad, 0xb1, 0x75} // "dead bits"
+
+func (s *stream) init(rwc io.ReadWriteCloser) {
+	// TODO have this also do the metadata handshake and create the peer struct
+	s.rwc = rwc
+	// TODO call something to do the metadata exchange
+}
+
+// writeMsg writes a message with stream padding, and is *not* thread safe.
+func (s *stream) writeMsg(bs []byte) (int, error) {
+	buf := util.GetBytes()
+	defer util.PutBytes(buf)
+	buf = append(buf, streamMsg[:]...)
+	buf = append(buf, wire_encode_uint64(uint64(len(bs)))...)
+	padLen := len(buf)
+	buf = append(buf, bs...)
+	var bn int
+	for bn < len(buf) {
+		n, err := s.rwc.Write(buf[bn:])
+		bn += n
+		if err != nil {
+			l := bn - padLen
+			if l < 0 {
+				l = 0
+			}
+			return l, err
+		}
+	}
+	return len(bs), nil
+}
+
+// readMsg reads a message from the stream, accounting for stream padding, and is *not* thread safe.
+func (s *stream) readMsg() ([]byte, error) {
+	for {
+		buf := s.inputBuffer
+		msg, ok, err := stream_chopMsg(&buf)
+		switch {
+		case err != nil:
+			// Something in the stream format is corrupt
+			return nil, fmt.Errorf("message error: %v", err)
+		case ok:
+			// Copy the packet into bs, shift the buffer, and return
+			msg = append(util.GetBytes(), msg...)
+			s.inputBuffer = append(s.inputBuffer[:0], buf...)
+			return msg, nil
+		default:
+			// Wait for the underlying reader to return enough info for us to proceed
+			frag := make([]byte, 2*streamMsgSize)
+			n, err := s.rwc.Read(frag)
+			if n > 0 {
+				s.inputBuffer = append(s.inputBuffer, frag[:n]...)
+			} else if err != nil {
+				return nil, err
+			}
+		}
+	}
+}
+
+// Writes metadata bytes without stream padding, meant to be temporary
+func (s *stream) _sendMetaBytes(metaBytes []byte) error {
+	var written int
+	for written < len(metaBytes) {
+		n, err := s.rwc.Write(metaBytes)
+		written += n
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Reads metadata bytes without stream padding, meant to be temporary
+func (s *stream) _recvMetaBytes() ([]byte, error) {
+	var meta version_metadata
+	frag := meta.encode()
+	metaBytes := make([]byte, 0, len(frag))
+	for len(metaBytes) < len(frag) {
+		n, err := s.rwc.Read(frag)
+		if err != nil {
+			return nil, err
+		}
+		metaBytes = append(metaBytes, frag[:n]...)
+	}
+	return metaBytes, nil
+}
+
+// This takes a pointer to a slice as an argument. It checks if there's a
+// complete message and, if so, slices out those parts and returns the message,
+// true, and nil. If there's no error, but also no complete message, it returns
+// nil, false, and nil. If there's an error, it returns nil, false, and the
+// error, which the reader then handles (currently, by returning from the
+// reader, which causes the connection to close).
+func stream_chopMsg(bs *[]byte) ([]byte, bool, error) {
+	// Returns msg, ok, err
+	if len(*bs) < len(streamMsg) {
+		return nil, false, nil
+	}
+	for idx := range streamMsg {
+		if (*bs)[idx] != streamMsg[idx] {
+			return nil, false, errors.New("bad message")
+		}
+	}
+	msgLen, msgLenLen := wire_decode_uint64((*bs)[len(streamMsg):])
+	if msgLen > streamMsgSize {
+		return nil, false, errors.New("oversized message")
+	}
+	msgBegin := len(streamMsg) + msgLenLen
+	msgEnd := msgBegin + int(msgLen)
+	if msgLenLen == 0 || len(*bs) < msgEnd {
+		// We don't have the full message
+		// Need to buffer this and wait for the rest to come in
+		return nil, false, nil
+	}
+	msg := (*bs)[msgBegin:msgEnd]
+	(*bs) = (*bs)[msgEnd:]
+	return msg, true, nil
+}

src/yggdrasil/switch.go

@@ -281,6 +281,7 @@ func (t *switchTable) cleanPeers() {
 		if now.Sub(peer.time) > switch_timeout+switch_throttle {
 			// Longer than switch_timeout to make sure we don't remove a working peer because the root stopped responding.
 			delete(t.data.peers, port)
+			go t.core.peers.removePeer(port) // TODO figure out if it's safe to do this without a goroutine, or make it safe
 		}
 	}
 	if _, isIn := t.data.peers[t.parent]; !isIn {

src/yggdrasil/tcp.go

@@ -16,34 +16,28 @@ package yggdrasil
 
 import (
 	"context"
-	"errors"
 	"fmt"
-	"io"
 	"math/rand"
 	"net"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	"golang.org/x/net/proxy"
 
-	"github.com/yggdrasil-network/yggdrasil-go/src/address"
 	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
-	"github.com/yggdrasil-network/yggdrasil-go/src/util"
 )
 
-const tcp_msgSize = 2048 + 65535 // TODO figure out what makes sense
+const default_timeout = 6 * time.Second
-const default_tcp_timeout = 6 * time.Second
+const tcp_ping_interval = (default_timeout * 2 / 3)
-const tcp_ping_interval = (default_tcp_timeout * 2 / 3)
 
 // The TCP listener and information about active TCP connections, to avoid duplication.
 type tcpInterface struct {
 	core        *Core
 	reconfigure chan chan error
 	serv        net.Listener
-	serv_stop   chan bool
+	stop        chan bool
-	tcp_timeout time.Duration
+	timeout     time.Duration
-	tcp_addr    string
+	addr        string
 	mutex       sync.Mutex // Protecting the below
 	calls       map[string]struct{}
 	conns       map[tcpInfo](chan struct{})
@@ -86,7 +80,7 @@ func (iface *tcpInterface) connectSOCKS(socksaddr, peeraddr string) {
 // Initializes the struct.
 func (iface *tcpInterface) init(core *Core) (err error) {
 	iface.core = core
-	iface.serv_stop = make(chan bool, 1)
+	iface.stop = make(chan bool, 1)
 	iface.reconfigure = make(chan chan error, 1)
 	go func() {
 		for {
@@ -95,7 +89,7 @@ func (iface *tcpInterface) init(core *Core) (err error) {
 			updated := iface.core.config.Listen != iface.core.configOld.Listen
 			iface.core.configMutex.RUnlock()
 			if updated {
-				iface.serv_stop <- true
+				iface.stop <- true
 				iface.serv.Close()
 				e <- iface.listen()
 			} else {
@@ -111,19 +105,19 @@ func (iface *tcpInterface) listen() error {
 	var err error
 
 	iface.core.configMutex.RLock()
-	iface.tcp_addr = iface.core.config.Listen
+	iface.addr = iface.core.config.Listen
-	iface.tcp_timeout = time.Duration(iface.core.config.ReadTimeout) * time.Millisecond
+	iface.timeout = time.Duration(iface.core.config.ReadTimeout) * time.Millisecond
 	iface.core.configMutex.RUnlock()
 
-	if iface.tcp_timeout >= 0 && iface.tcp_timeout < default_tcp_timeout {
+	if iface.timeout >= 0 && iface.timeout < default_timeout {
-		iface.tcp_timeout = default_tcp_timeout
+		iface.timeout = default_timeout
 	}
 
 	ctx := context.Background()
 	lc := net.ListenConfig{
 		Control: iface.tcpContext,
 	}
-	iface.serv, err = lc.Listen(ctx, "tcp", iface.tcp_addr)
+	iface.serv, err = lc.Listen(ctx, "tcp", iface.addr)
 	if err == nil {
 		iface.mutex.Lock()
 		iface.calls = make(map[string]struct{})
@@ -147,7 +141,7 @@ func (iface *tcpInterface) listener() {
 			return
 		}
 		select {
-		case <-iface.serv_stop:
+		case <-iface.stop:
 			iface.core.log.Errorln("Stopping listener")
 			return
 		default:
@@ -186,7 +180,7 @@ func (iface *tcpInterface) call(saddr string, socksaddr *string, sintf string) {
 		if sintf != "" {
 			callname = fmt.Sprintf("%s/%s", saddr, sintf)
 		}
-		if iface.isAlreadyCalling(saddr) {
+		if iface.isAlreadyCalling(callname) {
 			return
 		}
 		iface.mutex.Lock()
@@ -194,7 +188,7 @@ func (iface *tcpInterface) call(saddr string, socksaddr *string, sintf string) {
 		iface.mutex.Unlock()
 		defer func() {
 			// Block new calls for a little while, to mitigate livelock scenarios
-			time.Sleep(default_tcp_timeout)
+			time.Sleep(default_timeout)
 			time.Sleep(time.Duration(rand.Intn(1000)) * time.Millisecond)
 			iface.mutex.Lock()
 			delete(iface.calls, callname)
@@ -283,245 +277,21 @@ func (iface *tcpInterface) call(saddr string, socksaddr *string, sintf string) {
 	}()
 }
 
-// This exchanges/checks connection metadata, sets up the peer struct, sets up the writer goroutine, and then runs the reader within the current goroutine.
-// It defers a bunch of cleanup stuff to tear down all of these things when the reader exists (e.g. due to a closed connection or a timeout).
 func (iface *tcpInterface) handler(sock net.Conn, incoming bool) {
 	defer sock.Close()
 	iface.setExtraOptions(sock)
-	// Get our keys
+	stream := stream{}
-	myLinkPub, myLinkPriv := crypto.NewBoxKeys() // ephemeral link keys
+	stream.init(sock)
-	meta := version_getBaseMetadata()
+	local, _, _ := net.SplitHostPort(sock.LocalAddr().String())
-	meta.box = iface.core.boxPub
+	remote, _, _ := net.SplitHostPort(sock.RemoteAddr().String())
-	meta.sig = iface.core.sigPub
+	remotelinklocal := net.ParseIP(remote).IsLinkLocalUnicast()
-	meta.link = *myLinkPub
+	name := "tcp://" + sock.RemoteAddr().String()
-	metaBytes := meta.encode()
+	link, err := iface.core.link.create(&stream, name, "tcp", local, remote, incoming, remotelinklocal)
-	_, err := sock.Write(metaBytes)
 	if err != nil {
-		return
+		iface.core.log.Println(err)
+		panic(err)
 	}
-	if iface.tcp_timeout > 0 {
+	iface.core.log.Debugln("DEBUG: starting handler for", name)
-		sock.SetReadDeadline(time.Now().Add(iface.tcp_timeout))
+	err = link.handler()
-	}
+	iface.core.log.Debugln("DEBUG: stopped handler for", name, err)
-	_, err = sock.Read(metaBytes)
-	if err != nil {
-		return
-	}
-	meta = version_metadata{} // Reset to zero value
-	if !meta.decode(metaBytes) || !meta.check() {
-		// Failed to decode and check the metadata
-		// If it's a version mismatch issue, then print an error message
-		base := version_getBaseMetadata()
-		if meta.meta == base.meta {
-			if meta.ver > base.ver {
-				iface.core.log.Errorln("Failed to connect to node:", sock.RemoteAddr().String(), "version:", meta.ver)
-			} else if meta.ver == base.ver && meta.minorVer > base.minorVer {
-				iface.core.log.Errorln("Failed to connect to node:", sock.RemoteAddr().String(), "version:", fmt.Sprintf("%d.%d", meta.ver, meta.minorVer))
-			}
-		}
-		// TODO? Block forever to prevent future connection attempts? suppress future messages about the same node?
-		return
-	}
-	remoteAddr, _, e1 := net.SplitHostPort(sock.RemoteAddr().String())
-	localAddr, _, e2 := net.SplitHostPort(sock.LocalAddr().String())
-	if e1 != nil || e2 != nil {
-		return
-	}
-	info := tcpInfo{ // used as a map key, so don't include ephemeral link key
-		box:        meta.box,
-		sig:        meta.sig,
-		localAddr:  localAddr,
-		remoteAddr: remoteAddr,
-	}
-	if iface.isAlreadyConnected(info) {
-		return
-	}
-	// Quit the parent call if this is a connection to ourself
-	equiv := func(k1, k2 []byte) bool {
-		for idx := range k1 {
-			if k1[idx] != k2[idx] {
-				return false
-			}
-		}
-		return true
-	}
-	if equiv(meta.box[:], iface.core.boxPub[:]) {
-		return
-	}
-	if equiv(meta.sig[:], iface.core.sigPub[:]) {
-		return
-	}
-	// Check if we're authorized to connect to this key / IP
-	if incoming && !iface.core.peers.isAllowedEncryptionPublicKey(&meta.box) {
-		// Allow unauthorized peers if they're link-local
-		raddrStr, _, _ := net.SplitHostPort(sock.RemoteAddr().String())
-		raddr := net.ParseIP(raddrStr)
-		if !raddr.IsLinkLocalUnicast() {
-			return
-		}
-	}
-	// Check if we already have a connection to this node, close and block if yes
-	iface.mutex.Lock()
-	/*if blockChan, isIn := iface.conns[info]; isIn {
-		iface.mutex.Unlock()
-		sock.Close()
-		<-blockChan
-		return
-	}*/
-	blockChan := make(chan struct{})
-	iface.conns[info] = blockChan
-	iface.mutex.Unlock()
-	defer func() {
-		iface.mutex.Lock()
-		delete(iface.conns, info)
-		iface.mutex.Unlock()
-		close(blockChan)
-	}()
-	// Note that multiple connections to the same node are allowed
-	//  E.g. over different interfaces
-	p := iface.core.peers.newPeer(&meta.box, &meta.sig, crypto.GetSharedKey(myLinkPriv, &meta.link), sock.RemoteAddr().String())
-	p.linkOut = make(chan []byte, 1)
-	in := func(bs []byte) {
-		p.handlePacket(bs)
-	}
-	out := make(chan []byte, 1)
-	defer close(out)
-	go func() {
-		// This goroutine waits for outgoing packets, link protocol traffic, or sends idle keep-alive traffic
-		send := func(msg []byte) {
-			msgLen := wire_encode_uint64(uint64(len(msg)))
-			buf := net.Buffers{tcp_msg[:], msgLen, msg}
-			buf.WriteTo(sock)
-			atomic.AddUint64(&p.bytesSent, uint64(len(tcp_msg)+len(msgLen)+len(msg)))
-			util.PutBytes(msg)
-		}
-		timerInterval := tcp_ping_interval
-		timer := time.NewTimer(timerInterval)
-		defer timer.Stop()
-		for {
-			select {
-			case msg := <-p.linkOut:
-				// Always send outgoing link traffic first, if needed
-				send(msg)
-				continue
-			default:
-			}
-			// Otherwise wait reset the timer and wait for something to do
-			timer.Stop()
-			select {
-			case <-timer.C:
-			default:
-			}
-			timer.Reset(timerInterval)
-			select {
-			case _ = <-timer.C:
-				send(nil) // TCP keep-alive traffic
-			case msg := <-p.linkOut:
-				send(msg)
-			case msg, ok := <-out:
-				if !ok {
-					return
-				}
-				send(msg) // Block until the socket write has finished
-				// Now inform the switch that we're ready for more traffic
-				p.core.switchTable.idleIn <- p.port
-			}
-		}
-	}()
-	p.core.switchTable.idleIn <- p.port // Start in the idle state
-	p.out = func(msg []byte) {
-		defer func() { recover() }()
-		out <- msg
-	}
-	p.close = func() { sock.Close() }
-	go p.linkLoop()
-	defer func() {
-		// Put all of our cleanup here...
-		p.core.peers.removePeer(p.port)
-	}()
-	us, _, _ := net.SplitHostPort(sock.LocalAddr().String())
-	them, _, _ := net.SplitHostPort(sock.RemoteAddr().String())
-	themNodeID := crypto.GetNodeID(&meta.box)
-	themAddr := address.AddrForNodeID(themNodeID)
-	themAddrString := net.IP(themAddr[:]).String()
-	themString := fmt.Sprintf("%s@%s", themAddrString, them)
-	iface.core.log.Infof("Connected: %s, source: %s", themString, us)
-	err = iface.reader(sock, in) // In this goroutine, because of defers
-	if err == nil {
-		iface.core.log.Infof("Disconnected: %s, source: %s", themString, us)
-	} else {
-		iface.core.log.Infof("Disconnected: %s, source: %s, error: %s", themString, us, err)
-	}
-	return
-}
-
-// This reads from the socket into a []byte buffer for incomping messages.
-// It copies completed messages out of the cache into a new slice, and passes them to the peer struct via the provided `in func([]byte)` argument.
-// Then it shifts the incomplete fragments of data forward so future reads won't overwrite it.
-func (iface *tcpInterface) reader(sock net.Conn, in func([]byte)) error {
-	bs := make([]byte, 2*tcp_msgSize)
-	frag := bs[:0]
-	for {
-		if iface.tcp_timeout > 0 {
-			sock.SetReadDeadline(time.Now().Add(iface.tcp_timeout))
-		}
-		n, err := sock.Read(bs[len(frag):])
-		if n > 0 {
-			frag = bs[:len(frag)+n]
-			for {
-				msg, ok, err2 := tcp_chop_msg(&frag)
-				if err2 != nil {
-					return fmt.Errorf("Message error: %v", err2)
-				}
-				if !ok {
-					// We didn't get the whole message yet
-					break
-				}
-				newMsg := append(util.GetBytes(), msg...)
-				in(newMsg)
-				util.Yield()
-			}
-			frag = append(bs[:0], frag...)
-		}
-		if err != nil || n == 0 {
-			if err != io.EOF {
-				return err
-			}
-			return nil
-		}
-	}
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
-// These are 4 bytes of padding used to catch if something went horribly wrong with the tcp connection.
-var tcp_msg = [...]byte{0xde, 0xad, 0xb1, 0x75} // "dead bits"
-
-// This takes a pointer to a slice as an argument.
-// It checks if there's a complete message and, if so, slices out those parts and returns the message, true, and nil.
-// If there's no error, but also no complete message, it returns nil, false, and nil.
-// If there's an error, it returns nil, false, and the error, which the reader then handles (currently, by returning from the reader, which causes the connection to close).
-func tcp_chop_msg(bs *[]byte) ([]byte, bool, error) {
-	// Returns msg, ok, err
-	if len(*bs) < len(tcp_msg) {
-		return nil, false, nil
-	}
-	for idx := range tcp_msg {
-		if (*bs)[idx] != tcp_msg[idx] {
-			return nil, false, errors.New("Bad message!")
-		}
-	}
-	msgLen, msgLenLen := wire_decode_uint64((*bs)[len(tcp_msg):])
-	if msgLen > tcp_msgSize {
-		return nil, false, errors.New("Oversized message!")
-	}
-	msgBegin := len(tcp_msg) + msgLenLen
-	msgEnd := msgBegin + int(msgLen)
-	if msgLenLen == 0 || len(*bs) < msgEnd {
-		// We don't have the full message
-		// Need to buffer this and wait for the rest to come in
-		return nil, false, nil
-	}
-	msg := (*bs)[msgBegin:msgEnd]
-	(*bs) = (*bs)[msgEnd:]
-	return msg, true, nil
 }