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
|
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package tun
// #include <sys/types.h>
// static ssize_t callFnWithCtx(const void *func, const void *ctx, const void *buffer, size_t len)
// {
// return ((ssize_t(*)(const void *, const unsigned char *, size_t))func)(ctx, buffer, len);
// }
import "C"
import (
"os"
"syscall"
"unsafe"
)
type nativeTun struct {
events chan TUNEvent
mtu int
readFn unsafe.Pointer
writeFn unsafe.Pointer
ctx unsafe.Pointer
}
func CreateTUN(mtu int, readFn unsafe.Pointer, writeFn unsafe.Pointer, ctx unsafe.Pointer) TUNDevice {
tun := &nativeTun{
events: make(chan TUNEvent, 10),
mtu: mtu,
readFn: readFn,
writeFn: writeFn,
ctx: ctx,
}
tun.events <- TUNEventUp
return tun
}
func (tun *nativeTun) Name() (string, error) {
return "tun", nil
}
func (tun *nativeTun) File() *os.File {
return nil
}
func (tun *nativeTun) Events() chan TUNEvent {
return tun.events
}
func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
ret := C.callFnWithCtx(tun.readFn, tun.ctx, unsafe.Pointer(&buff[offset]), C.size_t(len(buff) - offset))
if ret < 0 {
return 0, syscall.Errno(-ret)
}
return int(ret), nil
}
func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
ret := C.callFnWithCtx(tun.writeFn, tun.ctx, unsafe.Pointer(&buff[offset]), C.size_t(len(buff) - offset))
if ret < 0 {
return 0, syscall.Errno(-ret)
}
return int(ret), nil
}
func (tun *nativeTun) Close() error {
if tun.events != nil {
close(tun.events)
}
return nil
}
func (tun *nativeTun) setMTU(n int) error {
tun.mtu = n
return nil
}
func (tun *nativeTun) MTU() (int, error) {
return tun.mtu, nil
}
|
