/
link.go
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/
link.go
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// Copyright 2016-2017 Authors of Cilium
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package link
import (
"fmt"
"time"
"github.com/cilium/cilium/pkg/lock"
"github.com/cilium/cilium/pkg/logging"
"github.com/cilium/cilium/pkg/logging/logfields"
"github.com/cilium/cilium/pkg/mac"
"github.com/vishvananda/netlink"
)
var linkCache ifNameCache
func init() {
go func() {
log := logging.DefaultLogger.WithField(logfields.LogSubsys, "link")
for {
if err := linkCache.syncCache(); err != nil {
log.WithError(err).Error("failed to obtain network links. stopping cache sync")
return
}
time.Sleep(15 * time.Second)
}
}()
}
// DeleteByName deletes the interface with the name ifName.
func DeleteByName(ifName string) error {
iface, err := netlink.LinkByName(ifName)
if err != nil {
return fmt.Errorf("failed to lookup %q: %v", ifName, err)
}
if err = netlink.LinkDel(iface); err != nil {
return fmt.Errorf("failed to delete %q: %v", ifName, err)
}
return nil
}
// Rename renames a network link
func Rename(curName, newName string) error {
link, err := netlink.LinkByName(curName)
if err != nil {
return err
}
return netlink.LinkSetName(link, newName)
}
func GetHardwareAddr(ifName string) (mac.MAC, error) {
iface, err := netlink.LinkByName(ifName)
if err != nil {
return nil, err
}
return mac.MAC(iface.Attrs().HardwareAddr), nil
}
func GetIfIndex(ifName string) (uint32, error) {
iface, err := netlink.LinkByName(ifName)
if err != nil {
return 0, err
}
return uint32(iface.Attrs().Index), nil
}
type ifNameCache struct {
mu lock.RWMutex
indexToName map[int]string
}
func (c *ifNameCache) syncCache() error {
links, err := netlink.LinkList()
if err != nil {
return err
}
indexToName := make(map[int]string, len(links))
for _, link := range links {
indexToName[link.Attrs().Index] = link.Attrs().Name
}
c.mu.Lock()
c.indexToName = indexToName
c.mu.Unlock()
return nil
}
func (c *ifNameCache) lookupName(ifIndex int) (string, bool) {
c.mu.RLock()
defer c.mu.RUnlock()
name, ok := c.indexToName[ifIndex]
return name, ok
}
// GetIfNameCached returns the name of an interface (if it exists) by looking
// it up in a regularly updated cache
func GetIfNameCached(ifIndex int) (string, bool) {
return linkCache.lookupName(ifIndex)
}