summaryrefslogtreecommitdiff
path: root/libgo/go/net/interface.go
blob: 9c7b5da8fe9153eeed290faae9aee24970fbe1b5 (plain)
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
// 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"

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 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
)

var flagNames = []string{
	"up",
	"broadcast",
	"loopback",
	"pointtopoint",
	"multicast",
}

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 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 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 {
		err = &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
	}
	return ift, err
}

// InterfaceAddrs returns a list of the system's network interface
// addresses.
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.
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}
	}
	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}
}