gh-654 loxilb non-privileged mode support for k8s

Author: TrekkieCoder

pkg/loxinet/layer2.go

@@ -111,7 +111,6 @@ func l2FdbAttrCopy(dst *FdbAttr, src *FdbAttr) {
 	dst.Dst = src.Dst
 }
 
-
 func (f *FdbEnt) tryResolveUpper(zn *Zone, addr net.IP) {
 	if f.Port == nil {
 		return
@@ -121,7 +120,7 @@ func (f *FdbEnt) tryResolveUpper(zn *Zone, addr net.IP) {
 		name = f.Port.SInfo.PortReal.Name
 	}
 
-    ret, Sip, _ :=  zn.L3.IfaSelect(name, addr, true)
+	ret, Sip, _ := zn.L3.IfaSelect(name, addr, true)
 	if ret != 0 {
 		tk.LogIt(tk.LogDebug, "tryResolve: failed to select l3 ifa select (%s:%s)\n", name, addr.String())
 		return

pkg/loxinet/loxinet.go

@@ -207,6 +207,7 @@ func loxiNetInit() {
 			RunCommand(MkfsScript, true)
 		}
 	}
+	utils.MkTunFsIfNotExist()
 
 	sysctlInit()
 

pkg/utils/net.go

@@ -23,9 +23,11 @@ import (
 	"crypto/x509"
 	"encoding/binary"
 	"errors"
+	"golang.org/x/sys/unix"
 	"io"
 	"net"
 	"net/http"
+	"os"
 	"syscall"
 	"time"
 	"unsafe"
@@ -336,3 +338,21 @@ func ArpResolver(dIP uint32) {
 		return
 	}
 }
+
+func MkTunFsIfNotExist() error {
+	tunPath := "/dev/net"
+	tunFile := "/dev/net/tun"
+	if _, err := os.Stat(tunPath); os.IsNotExist(err) {
+		if err := os.MkdirAll("/dev/net", 0751); err != nil {
+			return err
+		}
+	}
+
+	if _, err := os.Stat(tunFile); os.IsNotExist(err) {
+		dev := unix.Mkdev(10, 200)
+		if err := unix.Mknod("/dev/net/tun", 0600|unix.S_IFCHR, int(dev)); err != nil {
+			return err
+		}
+	}
+	return nil
+}