1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
// Copyright (C) 2016 Nippon Telegraph and Telephone Corporation.
//
// 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.
// +build linux
package config
import (
"fmt"
"net"
"github.com/vishvananda/netlink"
)
func GetIPv6LinkLocalNeighborAddress(ifname string) (string, error) {
ifi, err := net.InterfaceByName(ifname)
if err != nil {
return "", err
}
neighs, err := netlink.NeighList(ifi.Index, netlink.FAMILY_V6)
if err != nil {
return "", err
}
cnt := 0
var addr net.IP
for _, neigh := range neighs {
local, err := isLocalLinkLocalAddress(ifi.Index, neigh.IP)
if err != nil {
return "", err
}
if neigh.State&netlink.NUD_FAILED == 0 && neigh.IP.IsLinkLocalUnicast() && !local {
addr = neigh.IP
cnt++
}
}
if cnt == 0 {
return "", fmt.Errorf("no ipv6 link-local neighbor found")
} else if cnt > 1 {
return "", fmt.Errorf("found %d link-local neighbors. only support p2p link", cnt)
}
return fmt.Sprintf("%s%%%s", addr, ifname), nil
}
func isLocalLinkLocalAddress(ifindex int, addr net.IP) (bool, error) {
ifi, err := net.InterfaceByIndex(ifindex)
if err != nil {
return false, err
}
addrs, err := ifi.Addrs()
if err != nil {
return false, err
}
for _, a := range addrs {
if ip, _, _ := net.ParseCIDR(a.String()); addr.Equal(ip) {
return true, nil
}
}
return false, nil
}
|
