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
|
// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package nat
import (
"fmt"
"net"
"strings"
"time"
"github.com/jackpal/go-nat-pmp"
)
// natPMPClient adapts the NAT-PMP protocol implementation so it conforms to
// the common interface.
type pmp struct {
gw net.IP
c *natpmp.Client
}
func (n *pmp) String() string {
return fmt.Sprintf("NAT-PMP(%v)", n.gw)
}
func (n *pmp) ExternalIP() (net.IP, error) {
response, err := n.c.GetExternalAddress()
if err != nil {
return nil, err
}
return response.ExternalIPAddress[:], nil
}
func (n *pmp) AddMapping(protocol string, extport, intport int, name string, lifetime time.Duration) error {
if lifetime <= 0 {
return fmt.Errorf("lifetime must not be <= 0")
}
// Note order of port arguments is switched between our
// AddMapping and the client's AddPortMapping.
_, err := n.c.AddPortMapping(strings.ToLower(protocol), intport, extport, int(lifetime/time.Second))
return err
}
func (n *pmp) DeleteMapping(protocol string, extport, intport int) (err error) {
// To destroy a mapping, send an add-port with an internalPort of
// the internal port to destroy, an external port of zero and a
// time of zero.
_, err = n.c.AddPortMapping(strings.ToLower(protocol), intport, 0, 0)
return err
}
func discoverPMP() Interface {
// run external address lookups on all potential gateways
gws := potentialGateways()
found := make(chan *pmp, len(gws))
for i := range gws {
gw := gws[i]
go func() {
c := natpmp.NewClient(gw)
if _, err := c.GetExternalAddress(); err != nil {
found <- nil
} else {
found <- &pmp{gw, c}
}
}()
}
// return the one that responds first.
// discovery needs to be quick, so we stop caring about
// any responses after a very short timeout.
timeout := time.NewTimer(1 * time.Second)
defer timeout.Stop()
for _ = range gws {
select {
case c := <-found:
if c != nil {
return c
}
case <-timeout.C:
return nil
}
}
return nil
}
var (
// LAN IP ranges
_, lan10, _ = net.ParseCIDR("10.0.0.0/8")
_, lan176, _ = net.ParseCIDR("172.16.0.0/12")
_, lan192, _ = net.ParseCIDR("192.168.0.0/16")
)
// TODO: improve this. We currently assume that (on most networks)
// the router is X.X.X.1 in a local LAN range.
func potentialGateways() (gws []net.IP) {
ifaces, err := net.Interfaces()
if err != nil {
return nil
}
for _, iface := range ifaces {
ifaddrs, err := iface.Addrs()
if err != nil {
return gws
}
for _, addr := range ifaddrs {
switch x := addr.(type) {
case *net.IPNet:
if lan10.Contains(x.IP) || lan176.Contains(x.IP) || lan192.Contains(x.IP) {
ip := x.IP.Mask(x.Mask).To4()
if ip != nil {
ip[3] = ip[3] | 0x01
gws = append(gws, ip)
}
}
}
}
}
return gws
}
|
