Break deadlock by creating session recv queue when session is created instead of repointing at search completion, also make expired atomic

src/tuntap/tun.go

@@ -193,12 +193,13 @@ func (tun *TunAdapter) connReader(conn *yggdrasil.Conn) error {
 		delete(tun.conns, remoteNodeID)
 		tun.mutex.Unlock()
 	}()
+	tun.log.Debugln("Start connection reader for", conn.String())
 	b := make([]byte, 65535)
 	for {
 		n, err := conn.Read(b)
 		if err != nil {
 			tun.log.Errorln("TUN/TAP conn read error:", err)
-			return err
+			continue
 		}
 		if n == 0 {
 			continue
@@ -209,7 +210,7 @@ func (tun *TunAdapter) connReader(conn *yggdrasil.Conn) error {
 			continue
 		}
 		if w != n {
-			tun.log.Errorln("TUN/TAP iface write len didn't match conn read len")
+			tun.log.Errorln("TUN/TAP iface write mismatch:", w, "bytes written vs", n, "bytes given")
 			continue
 		}
 	}
@@ -220,7 +221,7 @@ func (tun *TunAdapter) ifaceReader() error {
 	for {
 		n, err := tun.iface.Read(bs)
 		if err != nil {
-			tun.log.Errorln("TUN/TAP iface read error:", err)
+			continue
 		}
 		// Look up if the dstination address is somewhere we already have an
 		// open connection to
@@ -253,6 +254,10 @@ func (tun *TunAdapter) ifaceReader() error {
 			// Unknown address length or protocol
 			continue
 		}
+		if !dstAddr.IsValid() && !dstSnet.IsValid() {
+			// For now don't deal with any non-Yggdrasil ranges
+			continue
+		}
 		dstNodeID, dstNodeIDMask = dstAddr.GetNodeIDandMask()
 		// Do we have an active connection for this node ID?
 		tun.mutex.Lock()
@@ -260,10 +265,11 @@ func (tun *TunAdapter) ifaceReader() error {
 			tun.mutex.Unlock()
 			w, err := conn.Write(bs)
 			if err != nil {
-				tun.log.Println("TUN/TAP conn write error:", err)
+				tun.log.Errorln("TUN/TAP conn write error:", err)
 				continue
 			}
 			if w != n {
+				tun.log.Errorln("TUN/TAP conn write mismatch:", w, "bytes written vs", n, "bytes given")
 				continue
 			}
 		} else {
@@ -273,7 +279,7 @@ func (tun *TunAdapter) ifaceReader() error {
 				go tun.connReader(&conn)
 			} else {
 				tun.mutex.Unlock()
-				tun.log.Println("TUN/TAP dial error:", err)
+				tun.log.Errorln("TUN/TAP dial error:", err)
 			}
 		}
 

src/yggdrasil/conn.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
@@ -17,9 +18,9 @@ type Conn struct {
 	recv          chan *wire_trafficPacket // Eventually gets attached to session.recv
 	mutex         *sync.RWMutex
 	session       *sessionInfo
-	readDeadline  time.Time // TODO timer
+	readDeadline  atomic.Value // time.Time // TODO timer
-	writeDeadline time.Time // TODO timer
+	writeDeadline atomic.Value // time.Time // TODO timer
-	expired       bool
+	expired       atomic.Value // bool
 }
 
 func (c *Conn) String() string {
@@ -32,14 +33,12 @@ func (c *Conn) startSearch() {
 		if err != nil {
 			c.core.log.Debugln("DHT search failed:", err)
 			c.mutex.Lock()
-			c.expired = true
+			c.expired.Store(true)
-			c.mutex.Unlock()
 			return
 		}
 		if sinfo != nil {
 			c.mutex.Lock()
 			c.session = sinfo
-			c.session.recv = c.recv
 			c.nodeID, c.nodeMask = sinfo.theirAddr.GetNodeIDandMask()
 			c.mutex.Unlock()
 		}
@@ -75,30 +74,20 @@ func (c *Conn) startSearch() {
 }
 
 func (c *Conn) Read(b []byte) (int, error) {
-	err := func() error {
+	if e, ok := c.expired.Load().(bool); ok && e {
-		c.mutex.RLock()
+		return 0, errors.New("session is closed")
-		defer c.mutex.RUnlock()
-		if c.expired {
-			return errors.New("session is closed")
-		}
-		return nil
-	}()
-	if err != nil {
-		return 0, err
 	}
+	c.mutex.RLock()
+	sinfo := c.session
+	c.mutex.RUnlock()
 	select {
 	// TODO...
 	case p, ok := <-c.recv:
 		if !ok {
-			c.mutex.Lock()
+			c.expired.Store(true)
-			c.expired = true
-			c.mutex.Unlock()
 			return 0, errors.New("session is closed")
 		}
 		defer util.PutBytes(p.Payload)
-		c.mutex.RLock()
-		sinfo := c.session
-		c.mutex.RUnlock()
 		var err error
 		sinfo.doWorker(func() {
 			if !sinfo.nonceIsOK(&p.Nonce) {
@@ -131,19 +120,12 @@ func (c *Conn) Read(b []byte) (int, error) {
 }
 
 func (c *Conn) Write(b []byte) (bytesWritten int, err error) {
-	var sinfo *sessionInfo
+	if e, ok := c.expired.Load().(bool); ok && e {
-	err = func() error {
+		return 0, errors.New("session is closed")
-		c.mutex.RLock()
-		defer c.mutex.RUnlock()
-		if c.expired {
-			return errors.New("session is closed")
-		}
-		sinfo = c.session
-		return nil
-	}()
-	if err != nil {
-		return 0, err
 	}
+	c.mutex.RLock()
+	sinfo := c.session
+	c.mutex.RUnlock()
 	if sinfo == nil {
 		c.core.router.doAdmin(func() {
 			c.startSearch()
@@ -173,7 +155,7 @@ func (c *Conn) Write(b []byte) (bytesWritten int, err error) {
 }
 
 func (c *Conn) Close() error {
-	c.expired = true
+	c.expired.Store(true)
 	c.session.close()
 	return nil
 }
@@ -195,11 +177,11 @@ func (c *Conn) SetDeadline(t time.Time) error {
 }
 
 func (c *Conn) SetReadDeadline(t time.Time) error {
-	c.readDeadline = t
+	c.readDeadline.Store(t)
 	return nil
 }
 
 func (c *Conn) SetWriteDeadline(t time.Time) error {
-	c.writeDeadline = t
+	c.writeDeadline.Store(t)
 	return nil
 }

src/yggdrasil/session.go

@@ -321,6 +321,7 @@ func (ss *sessions) createSession(theirPermKey *crypto.BoxPubKey) *sessionInfo {
 	sinfo.theirAddr = *address.AddrForNodeID(crypto.GetNodeID(&sinfo.theirPermPub))
 	sinfo.theirSubnet = *address.SubnetForNodeID(crypto.GetNodeID(&sinfo.theirPermPub))
 	sinfo.worker = make(chan func(), 1)
+	sinfo.recv = make(chan *wire_trafficPacket, 32)
 	ss.sinfos[sinfo.myHandle] = &sinfo
 	ss.byMySes[sinfo.mySesPub] = &sinfo.myHandle
 	ss.byTheirPerm[sinfo.theirPermPub] = &sinfo.myHandle
@@ -480,12 +481,11 @@ func (ss *sessions) handlePing(ping *sessionPing) {
 				mutex:    &sync.RWMutex{},
 				nodeID:   crypto.GetNodeID(&sinfo.theirPermPub),
 				nodeMask: &crypto.NodeID{},
-				recv:     make(chan *wire_trafficPacket, 32),
+				recv:     sinfo.recv,
 			}
 			for i := range conn.nodeMask {
 				conn.nodeMask[i] = 0xFF
 			}
-			sinfo.recv = conn.recv
 			ss.listener.conn <- conn
 		} else {
 			ss.core.log.Debugln("Received new session but there is no listener, ignoring")