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
|
package main
import (
"context"
"net"
"net/netip"
"github.com/insomniacslk/dhcp/dhcpv4"
"github.com/insomniacslk/dhcp/dhcpv6"
"github.com/insomniacslk/dhcp/dhcpv6/nclient6"
"github.com/insomniacslk/dhcp/iana"
gen "golang.zx2c4.com/wireguard/android/gen"
)
const (
ENABLE_PD = true
)
type dhcp struct {
fqdn string
hwAddr net.HardwareAddr
conn *net.UDPConn
serverAddr net.UDPAddr
client *nclient6.Client
linkAddr net.IP
peerAddr net.IP
}
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 getDuid(hwAddr net.HardwareAddr) dhcpv6.DUID {
duid := &dhcpv6.DUIDLL{
HWType: iana.HWTypeEthernet,
LinkLayerAddr: hwAddr,
}
return duid
}
func (d *dhcp) encapSendAndRead(ctx context.Context, msg *dhcpv6.Message, match nclient6.Matcher) (*dhcpv6.Message, error) {
packet, err := dhcpv6.EncapsulateRelay(msg, dhcpv6.MessageTypeRelayForward, d.linkAddr, d.peerAddr)
if err != nil {
return nil, err
}
relay, err := d.client.SendAndReadRelay(ctx, &d.serverAddr, packet, match)
if err != nil {
return nil, err
}
inner, err := relay.GetInnerMessage()
if err != nil {
return nil, err
}
return inner, nil
}
// isRelayMessageType returns a matcher that checks for the message type.
func isRelayMessageType(t dhcpv6.MessageType, tt ...dhcpv6.MessageType) nclient6.Matcher {
return func(p dhcpv6.DHCPv6) bool {
inner, err := p.GetInnerMessage()
if err != nil {
return false
}
if inner.Type() == t {
return true
}
for _, mt := range tt {
if inner.Type() == mt {
return true
}
}
return false
}
}
// func New() *dhcp {
// }
func RunDhcp(ctx context.Context, laddr, raddr netip.Addr) ([]*gen.Lease, error) {
d := &dhcp{}
d.linkAddr = net.ParseIP("fe80::101")
d.peerAddr = net.ParseIP("::1")
hostName := "foobar"
d.fqdn = hostName + ".m7n.se"
d.hwAddr = []byte{41, 42, 43, 44, 45, 46}
src := net.UDPAddr{IP: laddr.AsSlice(),
Port: 0, // Use non-restrict UDP source port
}
d.serverAddr = net.UDPAddr{IP: raddr.AsSlice(),
Port: 547,
}
err := d.Start(&src)
if err != nil {
return nil, err
}
defer d.Close()
reply, err := d.ObtainLease(ctx) // Use reply
if err != nil {
return nil, err
}
return getAddressesFromReply(reply), nil
}
func getAddressesFromReply(reply *dhcpv6.Message) []*gen.Lease{
var leases []*gen.Lease = make([]*gen.Lease, 0, 4)
if opt := reply.GetOneOption(dhcpv6.OptionIANA); opt != nil {
iana := opt.(*dhcpv6.OptIANA)
ianaOpts := iana.Options.Get(dhcpv6.OptionIAAddr)
for _, opt := range ianaOpts {
addr :=opt.(*dhcpv6.OptIAAddress).IPv6Addr
lease := &gen.Lease{
Address: &gen.InetAddress{
Address: addr,
},
// PreferredLifetime: ,
// ValidLifetime: ,
}
leases = append(leases, lease)
}
}
return leases
}
func (d *dhcp) Start(localAddr *net.UDPAddr) error {
conn, err := net.ListenUDP("udp6", localAddr)
if err != nil {
return err
}
d.client, err = nclient6.NewWithConn(conn, d.hwAddr, nclient6.WithDebugLogger())
return err
}
func (d *dhcp) Close() error {
err := d.client.Close()
d.client = nil
return err
}
func (d *dhcp) ObtainLease(ctx context.Context) (*dhcpv6.Message, error){
duidOpt := dhcpv6.WithClientID(getDuid(d.hwAddr))
fqdnOpt := dhcpv6.WithFQDN(0x1, d.fqdn)
solicit, err := dhcpv6.NewSolicit(d.hwAddr, duidOpt, fqdnOpt, dhcpv6.WithRapidCommit)
if err != nil {
return nil, err
}
msg, err := d.encapSendAndRead(ctx, solicit, isRelayMessageType(dhcpv6.MessageTypeReply, dhcpv6.MessageTypeAdvertise))
if err != nil {
return nil, err
}
if msg.Type() == dhcpv6.MessageTypeReply {
// We got RapidCommitted.
return msg, nil
}
// We didn't get RapidCommitted. Request regular lease.
req, err := dhcpv6.NewRequestFromAdvertise(msg, fqdnOpt)
if err != nil {
return nil, err
}
return d.encapSendAndRead(ctx, req, nil)
}
|
