hotfix: fix tun bug (#216)

Co-authored-by: wencaiwulue <895703375@qq.com>

pkg/core/tunhandler.go

@@ -18,9 +18,7 @@ import (
 )
 
 const (
-	MaxSize   = 1000
-	MaxThread = 10
-	MaxConn   = 1
+	MaxSize = 1000
 )
 
 type tunHandler struct {
@@ -171,8 +169,7 @@ func (h *tunHandler) printRoute(ctx context.Context) {
 }
 
 type Device struct {
-	tun    net.Conn
-	thread int
+	tun net.Conn
 
 	tunInboundRaw chan *DataElem
 	tunInbound    chan *DataElem
@@ -195,9 +192,11 @@ func (d *Device) readFromTun() {
 			}
 			return
 		}
-		d.tunInboundRaw <- &DataElem{
-			data:   b[:],
-			length: n,
+		if n != 0 {
+			d.tunInboundRaw <- &DataElem{
+				data:   b[:],
+				length: n,
+			}
 		}
 	}
 }
@@ -353,9 +352,7 @@ func genICMPPacketIPv6(src net.IP, dst net.IP) ([]byte, error) {
 
 func (d *Device) Start(ctx context.Context) {
 	go d.readFromTun()
-	for i := 0; i < d.thread; i++ {
-		go d.parseIPHeader()
-	}
+	go d.parseIPHeader()
 	go d.tunInboundHandler(d.tunInbound, d.tunOutbound)
 	go d.writeToTun()
 	go heartbeats(d.tun, d.tunInbound)
@@ -378,7 +375,6 @@ func (h *tunHandler) HandleServer(ctx context.Context, tun net.Conn) {
 
 	device := &Device{
 		tun:           tun,
-		thread:        MaxThread,
 		tunInboundRaw: make(chan *DataElem, MaxSize),
 		tunInbound:    make(chan *DataElem, MaxSize),
 		tunOutbound:   make(chan *DataElem, MaxSize),
@@ -435,8 +431,7 @@ type udpElem struct {
 }
 
 type Peer struct {
-	conn   net.PacketConn
-	thread int
+	conn net.PacketConn
 
 	connInbound    chan *udpElem
 	parsedConnInfo chan *udpElem
@@ -591,9 +586,7 @@ func (p *Peer) routeTUN() {
 func (p *Peer) Start() {
 	go p.readFromConn()
 	go p.readFromTCPConn()
-	for i := 0; i < p.thread; i++ {
-		go p.parseHeader()
-	}
+	go p.parseHeader()
 	go p.routePeer()
 	go p.routeTUN()
 }
@@ -605,7 +598,6 @@ func (p *Peer) Close() {
 func transportTun(ctx context.Context, tunInbound <-chan *DataElem, tunOutbound chan<- *DataElem, packetConn net.PacketConn, nat *NAT, connNAT *sync.Map) error {
 	p := &Peer{
 		conn:           packetConn,
-		thread:         MaxThread,
 		connInbound:    make(chan *udpElem, MaxSize),
 		parsedConnInfo: make(chan *udpElem, MaxSize),
 		tunInbound:     tunInbound,

pkg/tun/tun.go

@@ -3,6 +3,7 @@ package tun
 import (
 	"errors"
 	"net"
+	"os"
 	"time"
 
 	"github.com/containernetworking/cni/pkg/types"
@@ -87,18 +88,29 @@ func (c *tunConn) Read(b []byte) (n int, err error) {
 	defer config.LPool.Put(bytes[:])
 
 	var num int
-	sizes := []int{1}
+	sizes := make([]int, 1)
 	num, err = c.ifce.Read([][]byte{bytes[:]}, sizes, offset)
-	if err != nil || num == 0 {
+	if err != nil {
+		if errors.Is(err, tun.ErrTooManySegments) {
+			log.Errorf("Dropped some packets from multi-segment read: %v", err)
+			return 0, nil
+		}
+		if !errors.Is(err, os.ErrClosed) {
+			log.Errorf("Failed to read packet from TUN device: %v", err)
+			return 0, nil
+		}
 		return 0, err
 	}
+	if num == 0 {
+		return 0, nil
+	}
 	var size = sizes[0]
 	if size == 0 {
-		return 0, errors.New("tun packet is zero")
-	}
-	if size > device.MaxSegmentSize-device.MessageTransportHeaderSize {
-		return 0, errors.New("tun packet is too large")
+		return 0, nil
 	}
+	//if size > device.MaxSegmentSize-device.MessageTransportHeaderSize {
+	//	return 0, errors.New("tun packet is too large")
+	//}
 	return copy(b, bytes[offset:offset+size]), nil
 }
 

pkg/tun/tun_windows.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
+	"os"
 	"reflect"
 	"time"
 
@@ -153,11 +154,22 @@ func (c *winTunConn) Close() error {
 }
 
 func (c *winTunConn) Read(b []byte) (int, error) {
-	sizes := []int{1}
+	sizes := make([]int, 1)
 	num, err := c.ifce.Read([][]byte{b}, sizes, 0)
-	if err != nil || num == 0 {
+	if err != nil {
+		if errors.Is(err, wireguardtun.ErrTooManySegments) {
+			log.Errorf("Dropped some packets from multi-segment read: %v", err)
+			return 0, nil
+		}
+		if !errors.Is(err, os.ErrClosed) {
+			log.Errorf("Failed to read packet from TUN device: %v", err)
+			return 0, nil
+		}
 		return 0, err
 	}
+	if num == 0 {
+		return 0, nil
+	}
 	return sizes[0], nil
 }