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
249
250
251
252
253
254
255
256
257
258
259
|
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package net
import (
"errors"
"internal/itoa"
"sync"
"time"
)
// BUG(mikio): On JS, methods and functions related to
// Interface are not implemented.
// BUG(mikio): On AIX, DragonFly BSD, NetBSD, OpenBSD, Plan 9 and
// Solaris, the MulticastAddrs method of Interface is not implemented.
var (
errInvalidInterface = errors.New("invalid network interface")
errInvalidInterfaceIndex = errors.New("invalid network interface index")
errInvalidInterfaceName = errors.New("invalid network interface name")
errNoSuchInterface = errors.New("no such network interface")
errNoSuchMulticastInterface = errors.New("no such multicast network interface")
)
// Interface represents a mapping between network interface name
// and index. It also represents network interface facility
// information.
type Interface struct {
Index int // positive integer that starts at one, zero is never used
MTU int // maximum transmission unit
Name string // e.g., "en0", "lo0", "eth0.100"
HardwareAddr HardwareAddr // IEEE MAC-48, EUI-48 and EUI-64 form
Flags Flags // e.g., FlagUp, FlagLoopback, FlagMulticast
}
type Flags uint
const (
FlagUp Flags = 1 << iota // interface is administratively up
FlagBroadcast // interface supports broadcast access capability
FlagLoopback // interface is a loopback interface
FlagPointToPoint // interface belongs to a point-to-point link
FlagMulticast // interface supports multicast access capability
FlagRunning // interface is in running state
)
var flagNames = []string{
"up",
"broadcast",
"loopback",
"pointtopoint",
"multicast",
"running",
}
func (f Flags) String() string {
s := ""
for i, name := range flagNames {
if f&(1<<uint(i)) != 0 {
if s != "" {
s += "|"
}
s += name
}
}
if s == "" {
s = "0"
}
return s
}
// Addrs returns a list of unicast interface addresses for a specific
// interface.
func (ifi *Interface) Addrs() ([]Addr, error) {
if ifi == nil {
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: errInvalidInterface}
}
ifat, err := interfaceAddrTable(ifi)
if err != nil {
err = &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
}
return ifat, err
}
// MulticastAddrs returns a list of multicast, joined group addresses
// for a specific interface.
func (ifi *Interface) MulticastAddrs() ([]Addr, error) {
if ifi == nil {
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: errInvalidInterface}
}
ifat, err := interfaceMulticastAddrTable(ifi)
if err != nil {
err = &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
}
return ifat, err
}
// Interfaces returns a list of the system's network interfaces.
func Interfaces() ([]Interface, error) {
ift, err := interfaceTable(0)
if err != nil {
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
}
if len(ift) != 0 {
zoneCache.update(ift, false)
}
return ift, nil
}
// InterfaceAddrs returns a list of the system's unicast interface
// addresses.
//
// The returned list does not identify the associated interface; use
// Interfaces and Interface.Addrs for more detail.
func InterfaceAddrs() ([]Addr, error) {
ifat, err := interfaceAddrTable(nil)
if err != nil {
err = &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
}
return ifat, err
}
// InterfaceByIndex returns the interface specified by index.
//
// On Solaris, it returns one of the logical network interfaces
// sharing the logical data link; for more precision use
// InterfaceByName.
func InterfaceByIndex(index int) (*Interface, error) {
if index <= 0 {
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: errInvalidInterfaceIndex}
}
ift, err := interfaceTable(index)
if err != nil {
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
}
ifi, err := interfaceByIndex(ift, index)
if err != nil {
err = &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
}
return ifi, err
}
func interfaceByIndex(ift []Interface, index int) (*Interface, error) {
for _, ifi := range ift {
if index == ifi.Index {
return &ifi, nil
}
}
return nil, errNoSuchInterface
}
// InterfaceByName returns the interface specified by name.
func InterfaceByName(name string) (*Interface, error) {
if name == "" {
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: errInvalidInterfaceName}
}
ift, err := interfaceTable(0)
if err != nil {
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
}
if len(ift) != 0 {
zoneCache.update(ift, false)
}
for _, ifi := range ift {
if name == ifi.Name {
return &ifi, nil
}
}
return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: errNoSuchInterface}
}
// An ipv6ZoneCache represents a cache holding partial network
// interface information. It is used for reducing the cost of IPv6
// addressing scope zone resolution.
//
// Multiple names sharing the index are managed by first-come
// first-served basis for consistency.
type ipv6ZoneCache struct {
sync.RWMutex // guard the following
lastFetched time.Time // last time routing information was fetched
toIndex map[string]int // interface name to its index
toName map[int]string // interface index to its name
}
var zoneCache = ipv6ZoneCache{
toIndex: make(map[string]int),
toName: make(map[int]string),
}
// update refreshes the network interface information if the cache was last
// updated more than 1 minute ago, or if force is set. It reports whether the
// cache was updated.
func (zc *ipv6ZoneCache) update(ift []Interface, force bool) (updated bool) {
zc.Lock()
defer zc.Unlock()
now := time.Now()
if !force && zc.lastFetched.After(now.Add(-60*time.Second)) {
return false
}
zc.lastFetched = now
if len(ift) == 0 {
var err error
if ift, err = interfaceTable(0); err != nil {
return false
}
}
zc.toIndex = make(map[string]int, len(ift))
zc.toName = make(map[int]string, len(ift))
for _, ifi := range ift {
zc.toIndex[ifi.Name] = ifi.Index
if _, ok := zc.toName[ifi.Index]; !ok {
zc.toName[ifi.Index] = ifi.Name
}
}
return true
}
func (zc *ipv6ZoneCache) name(index int) string {
if index == 0 {
return ""
}
updated := zoneCache.update(nil, false)
zoneCache.RLock()
name, ok := zoneCache.toName[index]
zoneCache.RUnlock()
if !ok && !updated {
zoneCache.update(nil, true)
zoneCache.RLock()
name, ok = zoneCache.toName[index]
zoneCache.RUnlock()
}
if !ok { // last resort
name = itoa.Uitoa(uint(index))
}
return name
}
func (zc *ipv6ZoneCache) index(name string) int {
if name == "" {
return 0
}
updated := zoneCache.update(nil, false)
zoneCache.RLock()
index, ok := zoneCache.toIndex[name]
zoneCache.RUnlock()
if !ok && !updated {
zoneCache.update(nil, true)
zoneCache.RLock()
index, ok = zoneCache.toIndex[name]
zoneCache.RUnlock()
}
if !ok { // last resort
index, _, _ = dtoi(name)
}
return index
}
|
