/
getBridgeVlanId.go
60 lines (55 loc) · 1.13 KB
/
getBridgeVlanId.go
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package net
import (
"fmt"
"os"
"path/filepath"
"strings"
"github.com/Cloud-Foundations/Dominator/lib/fsutil"
)
const procNetVlan = "/proc/net/vlan"
func getBridgeVlanId(bridgeIf string) (int, error) {
dirname := filepath.Join(sysClassNet, bridgeIf, "brif")
ifNames, err := fsutil.ReadDirnames(dirname, false)
if err != nil {
return 0, err
}
retval := -1
for _, ifName := range ifNames {
if strings.HasPrefix(ifName, "tap") {
continue
}
if strings.HasSuffix(ifName, "-ll") {
continue
}
_, err := os.Stat(filepath.Join(sysClassNet, ifName, "tun_flags"))
if err == nil {
continue
}
vlanId, err := readVlanId(filepath.Join(procNetVlan, ifName))
if err != nil {
return 0, err
}
if vlanId >= 0 {
return int(vlanId), nil
}
retval = 0
}
return retval, nil
}
func readVlanId(filename string) (uint, error) {
file, err := os.Open(filename)
if err != nil {
if os.IsNotExist(err) {
return 0, nil
}
return 0, err
}
defer file.Close()
var dummy string
var vlanId uint
_, err = fmt.Fscanf(file, "%s VID: %d %s", &dummy, &vlanId, &dummy)
if err != nil {
return 0, err
}
return vlanId, nil
}