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Mikio Hara7ad508c2014-11-19 06:09:29 +09001// Copyright 2014 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package ipv6_test
6
7import (
8 "fmt"
9 "log"
10 "net"
11 "os"
12 "time"
13
Mikio Hara597bbe12014-12-03 12:33:31 +090014 "golang.org/x/net/icmp"
Mikio Hara7ad508c2014-11-19 06:09:29 +090015 "golang.org/x/net/ipv6"
16)
17
18func ExampleConn_markingTCP() {
Mikio Hara0d2c2e12015-12-15 09:19:55 +090019 ln, err := net.Listen("tcp", "[::]:1024")
Mikio Hara7ad508c2014-11-19 06:09:29 +090020 if err != nil {
21 log.Fatal(err)
22 }
23 defer ln.Close()
24
25 for {
26 c, err := ln.Accept()
27 if err != nil {
28 log.Fatal(err)
29 }
30 go func(c net.Conn) {
31 defer c.Close()
Mikio Hara0d2c2e12015-12-15 09:19:55 +090032 if c.RemoteAddr().(*net.TCPAddr).IP.To16() != nil && c.RemoteAddr().(*net.TCPAddr).IP.To4() == nil {
33 p := ipv6.NewConn(c)
34 if err := p.SetTrafficClass(0x28); err != nil { // DSCP AF11
35 log.Fatal(err)
36 }
37 if err := p.SetHopLimit(128); err != nil {
38 log.Fatal(err)
39 }
Mikio Hara7ad508c2014-11-19 06:09:29 +090040 }
41 if _, err := c.Write([]byte("HELLO-R-U-THERE-ACK")); err != nil {
42 log.Fatal(err)
43 }
44 }(c)
45 }
46}
47
48func ExamplePacketConn_servingOneShotMulticastDNS() {
49 c, err := net.ListenPacket("udp6", "[::]:5353") // mDNS over UDP
50 if err != nil {
51 log.Fatal(err)
52 }
53 defer c.Close()
54 p := ipv6.NewPacketConn(c)
55
56 en0, err := net.InterfaceByName("en0")
57 if err != nil {
58 log.Fatal(err)
59 }
60 mDNSLinkLocal := net.UDPAddr{IP: net.ParseIP("ff02::fb")}
61 if err := p.JoinGroup(en0, &mDNSLinkLocal); err != nil {
62 log.Fatal(err)
63 }
64 defer p.LeaveGroup(en0, &mDNSLinkLocal)
65 if err := p.SetControlMessage(ipv6.FlagDst|ipv6.FlagInterface, true); err != nil {
66 log.Fatal(err)
67 }
68
69 var wcm ipv6.ControlMessage
70 b := make([]byte, 1500)
71 for {
72 _, rcm, peer, err := p.ReadFrom(b)
73 if err != nil {
74 log.Fatal(err)
75 }
76 if !rcm.Dst.IsMulticast() || !rcm.Dst.Equal(mDNSLinkLocal.IP) {
77 continue
78 }
79 wcm.IfIndex = rcm.IfIndex
80 answers := []byte("FAKE-MDNS-ANSWERS") // fake mDNS answers, you need to implement this
81 if _, err := p.WriteTo(answers, &wcm, peer); err != nil {
82 log.Fatal(err)
83 }
84 }
85}
86
87func ExamplePacketConn_tracingIPPacketRoute() {
88 // Tracing an IP packet route to www.google.com.
89
90 const host = "www.google.com"
91 ips, err := net.LookupIP(host)
92 if err != nil {
93 log.Fatal(err)
94 }
95 var dst net.IPAddr
96 for _, ip := range ips {
97 if ip.To16() != nil && ip.To4() == nil {
98 dst.IP = ip
99 fmt.Printf("using %v for tracing an IP packet route to %s\n", dst.IP, host)
100 break
101 }
102 }
103 if dst.IP == nil {
104 log.Fatal("no AAAA record found")
105 }
106
Mikio Hara66f04182015-08-17 12:15:29 +0900107 c, err := net.ListenPacket("ip6:58", "::") // ICMP for IPv6
Mikio Hara7ad508c2014-11-19 06:09:29 +0900108 if err != nil {
109 log.Fatal(err)
110 }
111 defer c.Close()
112 p := ipv6.NewPacketConn(c)
113
114 if err := p.SetControlMessage(ipv6.FlagHopLimit|ipv6.FlagSrc|ipv6.FlagDst|ipv6.FlagInterface, true); err != nil {
115 log.Fatal(err)
116 }
117 wm := icmp.Message{
118 Type: ipv6.ICMPTypeEchoRequest, Code: 0,
119 Body: &icmp.Echo{
120 ID: os.Getpid() & 0xffff,
121 Data: []byte("HELLO-R-U-THERE"),
122 },
123 }
124 var f ipv6.ICMPFilter
125 f.SetAll(true)
Mikio Hara668aea82014-12-04 17:32:07 +0900126 f.Accept(ipv6.ICMPTypeTimeExceeded)
127 f.Accept(ipv6.ICMPTypeEchoReply)
Mikio Hara7ad508c2014-11-19 06:09:29 +0900128 if err := p.SetICMPFilter(&f); err != nil {
129 log.Fatal(err)
130 }
131
132 var wcm ipv6.ControlMessage
133 rb := make([]byte, 1500)
134 for i := 1; i <= 64; i++ { // up to 64 hops
135 wm.Body.(*icmp.Echo).Seq = i
136 wb, err := wm.Marshal(nil)
137 if err != nil {
138 log.Fatal(err)
139 }
140
141 // In the real world usually there are several
142 // multiple traffic-engineered paths for each hop.
143 // You may need to probe a few times to each hop.
144 begin := time.Now()
145 wcm.HopLimit = i
146 if _, err := p.WriteTo(wb, &wcm, &dst); err != nil {
147 log.Fatal(err)
148 }
149 if err := p.SetReadDeadline(time.Now().Add(3 * time.Second)); err != nil {
150 log.Fatal(err)
151 }
152 n, rcm, peer, err := p.ReadFrom(rb)
153 if err != nil {
154 if err, ok := err.(net.Error); ok && err.Timeout() {
155 fmt.Printf("%v\t*\n", i)
156 continue
157 }
158 log.Fatal(err)
159 }
Mikio Hara66f04182015-08-17 12:15:29 +0900160 rm, err := icmp.ParseMessage(58, rb[:n])
Mikio Hara7ad508c2014-11-19 06:09:29 +0900161 if err != nil {
162 log.Fatal(err)
163 }
164 rtt := time.Since(begin)
165
166 // In the real world you need to determine whether the
167 // received message is yours using ControlMessage.Src,
168 // ControlMesage.Dst, icmp.Echo.ID and icmp.Echo.Seq.
169 switch rm.Type {
170 case ipv6.ICMPTypeTimeExceeded:
171 names, _ := net.LookupAddr(peer.String())
172 fmt.Printf("%d\t%v %+v %v\n\t%+v\n", i, peer, names, rtt, rcm)
173 case ipv6.ICMPTypeEchoReply:
174 names, _ := net.LookupAddr(peer.String())
175 fmt.Printf("%d\t%v %+v %v\n\t%+v\n", i, peer, names, rtt, rcm)
176 return
177 }
178 }
179}
180
181func ExamplePacketConn_advertisingOSPFHello() {
Mikio Hara66f04182015-08-17 12:15:29 +0900182 c, err := net.ListenPacket("ip6:89", "::") // OSPF for IPv6
Mikio Hara7ad508c2014-11-19 06:09:29 +0900183 if err != nil {
184 log.Fatal(err)
185 }
186 defer c.Close()
187 p := ipv6.NewPacketConn(c)
188
189 en0, err := net.InterfaceByName("en0")
190 if err != nil {
191 log.Fatal(err)
192 }
193 allSPFRouters := net.IPAddr{IP: net.ParseIP("ff02::5")}
194 if err := p.JoinGroup(en0, &allSPFRouters); err != nil {
195 log.Fatal(err)
196 }
197 defer p.LeaveGroup(en0, &allSPFRouters)
198
199 hello := make([]byte, 24) // fake hello data, you need to implement this
200 ospf := make([]byte, 16) // fake ospf header, you need to implement this
201 ospf[0] = 3 // version 3
202 ospf[1] = 1 // hello packet
203 ospf = append(ospf, hello...)
204 if err := p.SetChecksum(true, 12); err != nil {
205 log.Fatal(err)
206 }
207
208 cm := ipv6.ControlMessage{
Mikio Hara66f04182015-08-17 12:15:29 +0900209 TrafficClass: 0xc0, // DSCP CS6
Mikio Hara7ad508c2014-11-19 06:09:29 +0900210 HopLimit: 1,
211 IfIndex: en0.Index,
212 }
213 if _, err := p.WriteTo(ospf, &cm, &allSPFRouters); err != nil {
214 log.Fatal(err)
215 }
216}