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
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
package main
import (
"encoding/binary"
"errors"
"fmt"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
"github.com/google/gopacket/pcap"
"net"
"time"
)
func GetIfaceAddrMulti(iface *net.Interface) ([]net.IP, error) {
addrs, err := iface.Addrs()
if err != nil {
return nil, errors.New("can not get ip address")
}
var srcIP []net.IP
for _, address := range addrs {
if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
if ipnet.IP.To16() != nil {
//check repeat
okToAdd := true
for _, temp := range srcIP {
if compareIPv6Addr(temp, ipnet.IP.To16()) == 0 {
okToAdd = false
break
}
}
if okToAdd {
srcIP = append(srcIP, ipnet.IP.To16())
}
}
}
}
if srcIP == nil || len(srcIP) == 0 {
return nil, errors.New("can not get ip address")
}
return srcIP, nil
}
func Send(handle *pcap.Handle, l ...gopacket.SerializableLayer) error {
opts := gopacket.SerializeOptions{
FixLengths: true,
ComputeChecksums: true,
}
buffer := gopacket.NewSerializeBuffer()
if err := gopacket.SerializeLayers(buffer, opts, l...); err != nil {
return err
}
return handle.WritePacketData(buffer.Bytes())
}
func GetIfaceAddr(iface *net.Interface) (net.IP, error) {
addrs, err := iface.Addrs()
if err != nil {
return nil, errors.New("can not get ip address")
}
var srcIP net.IP
for _, address := range addrs {
if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
if ipnet.IP.To16() != nil {
srcIP = ipnet.IP.To16()
break
}
}
}
if srcIP == nil {
return nil, errors.New("can not get ip address")
}
return srcIP, nil
}
func GetGatewayAddr(iface *net.Interface, handle *pcap.Handle, gatewayIP net.IP) (net.HardwareAddr, error) {
srcIP, err := GetIfaceAddr(iface)
if err != nil {
return nil, errors.New("can not get ip address")
}
start := time.Now()
// Prepare the layers to send for an ARP request.
eth := layers.Ethernet{
SrcMAC: iface.HardwareAddr,
DstMAC: net.HardwareAddr{0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
EthernetType: layers.EthernetTypeARP,
}
arp := layers.ARP{
AddrType: layers.LinkTypeEthernet,
Protocol: layers.EthernetTypeIPv6,
HwAddressSize: 6,
ProtAddressSize: 4,
Operation: layers.ARPRequest,
SourceHwAddress: []byte(iface.HardwareAddr),
SourceProtAddress: []byte(srcIP),
DstHwAddress: []byte{0, 0, 0, 0, 0, 0},
DstProtAddress: []byte(gatewayIP),
}
// Send a single ARP request packet (we never retry a send, since this
// is just an example ;)
if err := Send(handle, ð, &arp); err != nil {
return nil, err
}
// Wait 3 seconds for an ARP reply.
for {
if time.Since(start) > time.Second*3 {
return nil, errors.New("timeout getting ARP reply")
}
data, _, err := handle.ReadPacketData()
if err == pcap.NextErrorTimeoutExpired {
continue
} else if err != nil {
return nil, err
}
packet := gopacket.NewPacket(data, layers.LayerTypeEthernet, gopacket.NoCopy)
if arpLayer := packet.Layer(layers.LayerTypeARP); arpLayer != nil {
arp := arpLayer.(*layers.ARP)
if net.IP(arp.SourceProtAddress).Equal(gatewayIP) {
return arp.SourceHwAddress, nil
}
}
}
}
func compareIPv6Addr(ip0 net.IP, ip1 net.IP) int {
temp0 := binary.LittleEndian.Uint32(ip0.To16())
temp1 := binary.LittleEndian.Uint32(ip1.To16())
if temp0 == temp1 {
return 0
}
if temp0 > temp1 {
return 1
}
return -1
}
func xmitUDPv6(srcIP net.IP, dstIP net.IP, srcPort layers.UDPPort, dstPort layers.UDPPort, flowlabel uint32, timegap uint32) {
ipLayer := layers.IPv6{
FlowLabel: flowlabel,
SrcIP: srcIP,
DstIP: dstIP,
Version: 6,
HopLimit: 64,
NextHeader: layers.IPProtocolUDP,
}
udpLayer := layers.UDP{
SrcPort: srcPort,
DstPort: dstPort,
}
err := udpLayer.SetNetworkLayerForChecksum(&ipLayer)
if err != nil {
fmt.Println("xmitUDPv6 can not SetNetworkLayerForChecksum", err)
}
err = Send(handle, ethernetLayer, &ipLayer, &udpLayer)
if err != nil {
fmt.Println("xmitUDPv6 can not send packet", err)
}
if timegap != 0 {
time.Sleep(time.Duration(timegap) * time.Microsecond)
}
}
|
