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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
package main
import (
"context"
"fmt"
"log"
"net"
"net/netip"
"github.com/insomniacslk/dhcp/dhcpv4"
"github.com/insomniacslk/dhcp/dhcpv6"
"github.com/insomniacslk/dhcp/dhcpv6/nclient6"
"github.com/insomniacslk/dhcp/iana"
)
const (
ENABLE_PD = false
//ENABLE_PD = true
ENABLE_TA = false
//ENABLE_TA = true
//ENABLE_4O6 = false
ENABLE_4O6 = true
)
func withDHCPv4Msg(msg *dhcpv4.DHCPv4) dhcpv6.Modifier {
return func(d dhcpv6.DHCPv6) {
opt := dhcpv6.OptDHCPv4Msg{
Msg: msg,
}
d.UpdateOption(&opt)
}
}
func newDHCPv4Query(flags uint32, modifiers ...dhcpv6.Modifier) (*dhcpv6.Message, error) {
msg, err := dhcpv6.NewMessage()
if err != nil {
return nil, err
}
msg.MessageType = dhcpv6.MessageTypeDHCPv4Query
msg.TransactionID = dhcpv6.TransactionID{byte(flags >> 16), byte(flags >> 8), byte(flags)}
//msg.AddOption(dhcpv6.OptElapsedTime(0))
for _, mod := range modifiers {
mod(msg)
}
return msg, nil
}
// type DHCPv4o6Client struct {
// nclient4.Client
// }
func dhcpv4Query(ctx context.Context, client *nclient6.Client, dest *net.UDPAddr, msg *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, error) {
query, err := newDHCPv4Query(0x800000, withDHCPv4Msg(msg))
if err != nil {
return nil, err
}
resp, err := client.SendAndRead(ctx, dest, query, nil)
if err != nil {
return nil, err
}
msgOpt := resp.GetOneOption(dhcpv6.OptionDHCPv4Msg)
if msgOpt == nil {
return nil, fmt.Errorf("Missing DHCPv4Msg option in response")
}
offer := msgOpt.(*dhcpv6.OptDHCPv4Msg).Msg
return offer, nil
}
func newClientIDOpt(duid *dhcpv6.Duid) dhcpv4.Option {
iaid := []byte{0, 0, 0, 3}
ident := []byte{255} // Type IAID+DUID
ident = append(ident, iaid...) // IAID
ident = append(ident, duid.ToBytes()...) // DUID
return dhcpv4.OptClientIdentifier(ident)
}
func runDhcp4o6(ctx context.Context, client *nclient6.Client, v4o6 *dhcpv6.OptDHCP4oDHCP6Server, duid *dhcpv6.Duid, hwAddr net.HardwareAddr, hostName string) (*netip.Prefix, error) {
serverAddr := nclient6.AllDHCPRelayAgentsAndServers
if len(v4o6.DHCP4oDHCP6Servers) > 0 {
// TODO use all servers
serverAddr = &net.UDPAddr{
IP: v4o6.DHCP4oDHCP6Servers[0],
Port: dhcpv6.DefaultServerPort,
}
}
modHostName := dhcpv4.WithGeneric(dhcpv4.OptionHostName, []byte(hostName))
disc, err := dhcpv4.NewDiscovery(hwAddr, dhcpv4.WithOption(newClientIDOpt(duid)), modHostName)
if err != nil {
return nil, err
}
offer, err := dhcpv4Query(ctx, client, serverAddr, disc)
if err != nil {
return nil, err
}
req, err := dhcpv4.NewRequestFromOffer(offer, modHostName)
if err != nil {
return nil, err
}
ack, err := dhcpv4Query(ctx, client, serverAddr, req)
if err != nil {
return nil, err
}
// client.Close()
fmt.Println("doClient end", ack.YourIPAddr, ack.SubnetMask())
if ip4 := ack.YourIPAddr.To4(); ip4 == nil {
return nil, fmt.Errorf("Not IPv4! %v", ack.YourIPAddr)
} else {
log.Println("IPv4", ip4)
}
addr, _ := netip.AddrFromSlice(ack.YourIPAddr)
prefix := netip.PrefixFrom(addr, 32) // TODO use SubnetMask
log.Printf("Append %v", prefix)
return &prefix, nil
}
func RunDhcp(ctx context.Context, conn *net.UDPConn, hwAddr net.HardwareAddr) ([]netip.Prefix, error) {
client, err := nclient6.NewWithConn(conn, hwAddr, nclient6.WithDebugLogger())
if err != nil {
return nil, err
}
duid := dhcpv6.Duid{
Type: dhcpv6.DUID_LL,
HwType: iana.HWTypeEthernet,
LinkLayerAddr: hwAddr,
}
hostName := "gvisor"
fqdn := hostName + ".m7n.se"
fqdnOpt := dhcpv6.WithFQDN(0x1, fqdn)
solicitMods := []dhcpv6.Modifier{}
if ENABLE_PD {
_, iaIPNet, err := net.ParseCIDR("::/64")
if err != nil {
return nil, err
}
iaPrefix := dhcpv6.OptIAPrefix{
0, 0, iaIPNet, dhcpv6.PrefixOptions{},
}
solicitMods = append(solicitMods, dhcpv6.WithIAPD([4]byte{0, 0, 0, 1}, &iaPrefix))
}
if ENABLE_TA {
solicitMods = append(solicitMods, dhcpv6.WithIATA([4]byte{0, 0, 0, 1}))
}
oro := dhcpv6.WithRequestedOptions(dhcpv6.OptionDHCP4oDHCP6Server, dhcpv6.OptionFQDN)
solicitMods = append(solicitMods, dhcpv6.WithIAID([4]byte{0, 0, 0, 1}))
solicitMods = append(solicitMods, fqdnOpt)
solicitMods = append(solicitMods, dhcpv6.WithClientID(duid))
solicitMods = append(solicitMods, oro)
adv, err := client.Solicit(ctx, solicitMods...)
if err != nil {
return nil, err
}
requestMods := []dhcpv6.Modifier{}
requestMods = append(requestMods, fqdnOpt)
requestMods = append(requestMods, oro)
if ENABLE_TA {
// Add IA_TA from advertise which is not added by default.
withIaTa := func(req dhcpv6.DHCPv6) {
if iaTa := adv.GetOneOption(dhcpv6.OptionIATA); iaTa != nil {
req.AddOption(iaTa)
}
}
requestMods = append(requestMods, withIaTa)
}
msg, err := client.Request(ctx, adv, requestMods...)
if err != nil {
return nil, err
}
iana := msg.GetOneOption(dhcpv6.OptionIANA).(*dhcpv6.OptIANA)
ianaOpts := iana.Options.Get(dhcpv6.OptionIAAddr)
var iapdOpts []dhcpv6.Option
if ENABLE_PD {
iapd := msg.GetOneOption(dhcpv6.OptionIAPD).(*dhcpv6.OptIAPD)
iapdOpts = iapd.Options.Get(dhcpv6.OptionIAPrefix)
}
addrs := make([]netip.Prefix, 0, len(ianaOpts)+len(iapdOpts)+1)
opt4o6 := msg.GetOneOption(dhcpv6.OptionDHCP4oDHCP6Server)
if ENABLE_4O6 && opt4o6 != nil {
v4o6 := opt4o6.(*dhcpv6.OptDHCP4oDHCP6Server)
log.Println("dhcp4o6: ", v4o6)
prefix, err := runDhcp4o6(ctx, client, v4o6, &duid, hwAddr, hostName)
if err == nil {
addrs = append(addrs, *prefix)
} else {
return nil, err
}
}
for _, addr := range ianaOpts {
prefix := netip.PrefixFrom(netip.IPv6Unspecified(), 128)
ip, ok := netip.AddrFromSlice(addr.(*dhcpv6.OptIAAddress).IPv6Addr)
if ok {
prefix = netip.PrefixFrom(ip, 128)
}
log.Printf("IANA %v", prefix)
addrs = append(addrs, prefix)
}
for _, addr := range iapdOpts {
ipnet := addr.(*dhcpv6.OptIAPrefix).Prefix
addr, _ := netip.AddrFromSlice(ipnet.IP) // TODO use ok
prefixlen, _ := ipnet.Mask.Size()
prefix := netip.PrefixFrom(addr, prefixlen)
log.Printf("IAPD %v", prefix)
addrs = append(addrs, prefix)
}
opt := msg.GetOneOption(dhcpv6.OptionIATA)
if opt != nil {
iata := opt.(*dhcpv6.OptIATA)
taOpts := iata.Options.Get(dhcpv6.OptionIAAddr)
for _, addr := range taOpts {
ip := addr.(*dhcpv6.OptIAAddress).IPv6Addr
addr, _ := netip.AddrFromSlice(ip) // TODO use ok
prefix := netip.PrefixFrom(addr, 128)
log.Printf("IATA %v", prefix)
}
}
return addrs, nil
}
|
