aboutsummaryrefslogtreecommitdiffstats
path: root/conn_default.go
blob: 7204a0343e6a31a0381c4a9bb6634c847de408ee (plain) (blame)
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
// +build !linux

/* SPDX-License-Identifier: GPL-2.0
 *
 * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 */

package main

import (
	"net"
)

/* This code is meant to be a temporary solution
 * on platforms for which the sticky socket / source caching behavior
 * has not yet been implemented.
 *
 * See conn_linux.go for an implementation on the linux platform.
 */

type NativeBind struct {
	ipv4 *net.UDPConn
	ipv6 *net.UDPConn
}

type NativeEndpoint net.UDPAddr

var _ Bind = (*NativeBind)(nil)
var _ Endpoint = (*NativeEndpoint)(nil)

func CreateEndpoint(s string) (Endpoint, error) {
	addr, err := parseEndpoint(s)
	return (*NativeEndpoint)(addr), err
}

func (_ *NativeEndpoint) ClearSrc() {}

func (e *NativeEndpoint) DstIP() net.IP {
	return (*net.UDPAddr)(e).IP
}

func (e *NativeEndpoint) SrcIP() net.IP {
	return nil // not supported
}

func (e *NativeEndpoint) DstToBytes() []byte {
	addr := (*net.UDPAddr)(e)
	out := addr.IP.To4()
	if out == nil {
		out = addr.IP
	}
	out = append(out, byte(addr.Port&0xff))
	out = append(out, byte((addr.Port>>8)&0xff))
	return out
}

func (e *NativeEndpoint) DstToString() string {
	return (*net.UDPAddr)(e).String()
}

func (e *NativeEndpoint) SrcToString() string {
	return ""
}

func listenNet(network string, port int) (*net.UDPConn, int, error) {

	// listen

	conn, err := net.ListenUDP(network, &net.UDPAddr{Port: port})
	if err != nil {
		return nil, 0, err
	}

	// retrieve port

	laddr := conn.LocalAddr()
	uaddr, err := net.ResolveUDPAddr(
		laddr.Network(),
		laddr.String(),
	)
	if err != nil {
		return nil, 0, err
	}
	return conn, uaddr.Port, nil
}

func CreateBind(uport uint16, device *Device) (Bind, uint16, error) {
	var err error
	var bind NativeBind

	port := int(uport)

	bind.ipv4, port, err = listenNet("udp4", port)
	if err != nil {
		return nil, 0, err
	}

	bind.ipv6, port, err = listenNet("udp6", port)
	if err != nil {
		bind.ipv4.Close()
		return nil, 0, err
	}

	return &bind, uint16(port), nil
}

func (bind *NativeBind) Close() error {
	err1 := bind.ipv4.Close()
	err2 := bind.ipv6.Close()
	if err1 != nil {
		return err1
	}
	return err2
}

func (bind *NativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
	n, endpoint, err := bind.ipv4.ReadFromUDP(buff)
	if endpoint != nil {
		endpoint.IP = endpoint.IP.To4()
	}
	return n, (*NativeEndpoint)(endpoint), err
}

func (bind *NativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
	n, endpoint, err := bind.ipv6.ReadFromUDP(buff)
	return n, (*NativeEndpoint)(endpoint), err
}

func (bind *NativeBind) Send(buff []byte, endpoint Endpoint) error {
	var err error
	nend := endpoint.(*NativeEndpoint)
	if nend.IP.To4() != nil {
		_, err = bind.ipv4.WriteToUDP(buff, (*net.UDPAddr)(nend))
	} else {
		_, err = bind.ipv6.WriteToUDP(buff, (*net.UDPAddr)(nend))
	}
	return err
}

func (bind *NativeBind) SetMark(_ uint32) error {
	return nil
}