This repository has been archived by the owner on Feb 24, 2020. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 887
/
dbus.go
163 lines (139 loc) · 4.22 KB
/
dbus.go
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
// Copyright 2015 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Integration with the systemd D-Bus API. See http://www.freedesktop.org/wiki/Software/systemd/dbus/
package dbus
import (
"fmt"
"os"
"strconv"
"strings"
"sync"
"github.com/coreos/rkt/Godeps/_workspace/src/github.com/godbus/dbus"
)
const (
alpha = `abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ`
num = `0123456789`
alphanum = alpha + num
signalBuffer = 100
)
// needsEscape checks whether a byte in a potential dbus ObjectPath needs to be escaped
func needsEscape(i int, b byte) bool {
// Escape everything that is not a-z-A-Z-0-9
// Also escape 0-9 if it's the first character
return strings.IndexByte(alphanum, b) == -1 ||
(i == 0 && strings.IndexByte(num, b) != -1)
}
// PathBusEscape sanitizes a constituent string of a dbus ObjectPath using the
// rules that systemd uses for serializing special characters.
func PathBusEscape(path string) string {
// Special case the empty string
if len(path) == 0 {
return "_"
}
n := []byte{}
for i := 0; i < len(path); i++ {
c := path[i]
if needsEscape(i, c) {
e := fmt.Sprintf("_%x", c)
n = append(n, []byte(e)...)
} else {
n = append(n, c)
}
}
return string(n)
}
// Conn is a connection to systemd's dbus endpoint.
type Conn struct {
// sysconn/sysobj are only used to call dbus methods
sysconn *dbus.Conn
sysobj *dbus.Object
// sigconn/sigobj are only used to receive dbus signals
sigconn *dbus.Conn
sigobj *dbus.Object
jobListener struct {
jobs map[dbus.ObjectPath]chan<- string
sync.Mutex
}
subscriber struct {
updateCh chan<- *SubStateUpdate
errCh chan<- error
sync.Mutex
ignore map[dbus.ObjectPath]int64
cleanIgnore int64
}
}
// New establishes a connection to the system bus and authenticates.
// Callers should call Close() when done with the connection.
func New() (*Conn, error) {
return newConnection(dbus.SystemBusPrivate)
}
// NewUserConnection establishes a connection to the session bus and
// authenticates. This can be used to connect to systemd user instances.
// Callers should call Close() when done with the connection.
func NewUserConnection() (*Conn, error) {
return newConnection(dbus.SessionBusPrivate)
}
// Close closes an established connection
func (c *Conn) Close() {
c.sysconn.Close()
c.sigconn.Close()
}
func newConnection(createBus func() (*dbus.Conn, error)) (*Conn, error) {
sysconn, err := dbusConnection(createBus)
if err != nil {
return nil, err
}
sigconn, err := dbusConnection(createBus)
if err != nil {
sysconn.Close()
return nil, err
}
c := &Conn{
sysconn: sysconn,
sysobj: systemdObject(sysconn),
sigconn: sigconn,
sigobj: systemdObject(sigconn),
}
c.subscriber.ignore = make(map[dbus.ObjectPath]int64)
c.jobListener.jobs = make(map[dbus.ObjectPath]chan<- string)
// Setup the listeners on jobs so that we can get completions
c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
"type='signal', interface='org.freedesktop.systemd1.Manager', member='JobRemoved'")
c.dispatch()
return c, nil
}
func dbusConnection(createBus func() (*dbus.Conn, error)) (*dbus.Conn, error) {
conn, err := createBus()
if err != nil {
return nil, err
}
// Only use EXTERNAL method, and hardcode the uid (not username)
// to avoid a username lookup (which requires a dynamically linked
// libc)
methods := []dbus.Auth{dbus.AuthExternal(strconv.Itoa(os.Getuid()))}
err = conn.Auth(methods)
if err != nil {
conn.Close()
return nil, err
}
err = conn.Hello()
if err != nil {
conn.Close()
return nil, err
}
return conn, nil
}
func systemdObject(conn *dbus.Conn) *dbus.Object {
return conn.Object("org.freedesktop.systemd1", dbus.ObjectPath("/org/freedesktop/systemd1"))
}