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
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
package networkdriver
import (
"encoding/binary"
"errors"
"fmt"
"net"
"github.com/dotcloud/docker/pkg/netlink"
)
var (
networkGetRoutesFct = netlink.NetworkGetRoutes
ErrNoDefaultRoute = errors.New("no default route")
)
func CheckNameserverOverlaps(nameservers []string, toCheck *net.IPNet) error {
if len(nameservers) > 0 {
for _, ns := range nameservers {
_, nsNetwork, err := net.ParseCIDR(ns)
if err != nil {
return err
}
if NetworkOverlaps(toCheck, nsNetwork) {
return ErrNetworkOverlapsWithNameservers
}
}
}
return nil
}
func CheckRouteOverlaps(toCheck *net.IPNet) error {
networks, err := networkGetRoutesFct()
if err != nil {
return err
}
for _, network := range networks {
if network.IPNet != nil && NetworkOverlaps(toCheck, network.IPNet) {
return ErrNetworkOverlaps
}
}
return nil
}
// Detects overlap between one IPNet and another
func NetworkOverlaps(netX *net.IPNet, netY *net.IPNet) bool {
if firstIP, _ := NetworkRange(netX); netY.Contains(firstIP) {
return true
}
if firstIP, _ := NetworkRange(netY); netX.Contains(firstIP) {
return true
}
return false
}
// Calculates the first and last IP addresses in an IPNet
func NetworkRange(network *net.IPNet) (net.IP, net.IP) {
var (
netIP = network.IP.To4()
firstIP = netIP.Mask(network.Mask)
lastIP = net.IPv4(0, 0, 0, 0).To4()
)
for i := 0; i < len(lastIP); i++ {
lastIP[i] = netIP[i] | ^network.Mask[i]
}
return firstIP, lastIP
}
// Given a netmask, calculates the number of available hosts
func NetworkSize(mask net.IPMask) int32 {
m := net.IPv4Mask(0, 0, 0, 0)
for i := 0; i < net.IPv4len; i++ {
m[i] = ^mask[i]
}
return int32(binary.BigEndian.Uint32(m)) + 1
}
// Return the IPv4 address of a network interface
func GetIfaceAddr(name string) (net.Addr, error) {
iface, err := net.InterfaceByName(name)
if err != nil {
return nil, err
}
addrs, err := iface.Addrs()
if err != nil {
return nil, err
}
var addrs4 []net.Addr
for _, addr := range addrs {
ip := (addr.(*net.IPNet)).IP
if ip4 := ip.To4(); len(ip4) == net.IPv4len {
addrs4 = append(addrs4, addr)
}
}
switch {
case len(addrs4) == 0:
return nil, fmt.Errorf("Interface %v has no IP addresses", name)
case len(addrs4) > 1:
fmt.Printf("Interface %v has more than 1 IPv4 address. Defaulting to using %v\n",
name, (addrs4[0].(*net.IPNet)).IP)
}
return addrs4[0], nil
}
func GetDefaultRouteIface() (*net.Interface, error) {
rs, err := networkGetRoutesFct()
if err != nil {
return nil, fmt.Errorf("unable to get routes: %v", err)
}
for _, r := range rs {
if r.Default {
return r.Iface, nil
}
}
return nil, ErrNoDefaultRoute
}
|
