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
|
// +build darwin freebsd openbsd
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
* Copyright (C) 2017-2018 Mathias N. Hall-Andersen <mathias@hall-andersen.dk>.
*/
package main
import (
"errors"
"fmt"
"golang.org/x/sys/unix"
"net"
"os"
"path"
"unsafe"
)
const (
ipcErrorIO = -int64(unix.EIO)
ipcErrorProtocol = -int64(unix.EPROTO)
ipcErrorInvalid = -int64(unix.EINVAL)
ipcErrorPortInUse = -int64(unix.EADDRINUSE)
socketDirectory = "/var/run/wireguard"
socketName = "%s.sock"
)
type UAPIListener struct {
listener net.Listener // unix socket listener
connNew chan net.Conn
connErr chan error
kqueueFd int
keventFd int
}
func (l *UAPIListener) Accept() (net.Conn, error) {
for {
select {
case conn := <-l.connNew:
return conn, nil
case err := <-l.connErr:
return nil, err
}
}
}
func (l *UAPIListener) Close() error {
err1 := unix.Close(l.kqueueFd)
err2 := unix.Close(l.keventFd)
err3 := l.listener.Close()
if err1 != nil {
return err1
}
if err2 != nil {
return err2
}
return err3
}
func (l *UAPIListener) Addr() net.Addr {
return l.listener.Addr()
}
func UAPIListen(name string, file *os.File) (net.Listener, error) {
// wrap file in listener
listener, err := net.FileListener(file)
if err != nil {
return nil, err
}
uapi := &UAPIListener{
listener: listener,
connNew: make(chan net.Conn, 1),
connErr: make(chan error, 1),
}
if unixListener, ok := listener.(*net.UnixListener); ok {
unixListener.SetUnlinkOnClose(true)
}
socketPath := path.Join(
socketDirectory,
fmt.Sprintf(socketName, name),
)
// watch for deletion of socket
uapi.kqueueFd, err = unix.Kqueue()
if err != nil {
return nil, err
}
uapi.keventFd, err = unix.Open(socketDirectory, unix.O_RDONLY, 0)
if err != nil {
unix.Close(uapi.kqueueFd)
return nil, err
}
go func(l *UAPIListener) {
event := unix.Kevent_t{
Filter: unix.EVFILT_VNODE,
Flags: unix.EV_ADD | unix.EV_ENABLE | unix.EV_ONESHOT,
Fflags: unix.NOTE_WRITE,
}
// Allow this assignment to work with both the 32-bit and 64-bit version
// of the above struct. If you know another way, please submit a patch.
*(*uintptr)(unsafe.Pointer(&event.Ident)) = uintptr(uapi.keventFd)
events := make([]unix.Kevent_t, 1)
n := 1
var kerr error
for {
// start with lstat to avoid race condition
if _, err := os.Lstat(socketPath); os.IsNotExist(err) {
l.connErr <- err
return
}
if kerr != nil || n != 1 {
if kerr != nil {
l.connErr <- kerr
} else {
l.connErr <- errors.New("kqueue returned empty")
}
return
}
n, kerr = unix.Kevent(uapi.kqueueFd, []unix.Kevent_t{event}, events, nil)
}
}(uapi)
// watch for new connections
go func(l *UAPIListener) {
for {
conn, err := l.listener.Accept()
if err != nil {
l.connErr <- err
break
}
l.connNew <- conn
}
}(uapi)
return uapi, nil
}
func UAPIOpen(name string) (*os.File, error) {
// check if path exist
err := os.MkdirAll(socketDirectory, 0700)
if err != nil && !os.IsExist(err) {
return nil, err
}
// open UNIX socket
socketPath := path.Join(
socketDirectory,
fmt.Sprintf(socketName, name),
)
addr, err := net.ResolveUnixAddr("unix", socketPath)
if err != nil {
return nil, err
}
listener, err := func() (*net.UnixListener, error) {
// initial connection attempt
listener, err := net.ListenUnix("unix", addr)
if err == nil {
return listener, nil
}
// check if socket already active
_, err = net.Dial("unix", socketPath)
if err == nil {
return nil, errors.New("unix socket in use")
}
// cleanup & attempt again
err = os.Remove(socketPath)
if err != nil {
return nil, err
}
return net.ListenUnix("unix", addr)
}()
if err != nil {
return nil, err
}
return listener.File()
}
|
