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
|
package system
import (
"bytes"
"context"
"errors"
"fmt"
"log"
"strings"
"sync"
"syscall"
"hakurei.app/system/dbus"
)
var (
ErrDBusConfig = errors.New("dbus config not supplied")
)
// MustProxyDBus calls ProxyDBus and panics if an error is returned.
func (sys *I) MustProxyDBus(sessionPath string, session *dbus.Config, systemPath string, system *dbus.Config) *I {
if _, err := sys.ProxyDBus(session, system, sessionPath, systemPath); err != nil {
panic(err.Error())
} else {
return sys
}
}
// ProxyDBus finalises configuration and appends [DBusProxyOp] to [I].
func (sys *I) ProxyDBus(session, system *dbus.Config, sessionPath, systemPath string) (func(), error) {
d := new(DBusProxyOp)
// session bus is required as otherwise this is effectively a very expensive noop
if session == nil {
return nil, newOpErrorMessage("dbus", ErrDBusConfig,
"attempted to create message bus proxy args without session bus config", false)
}
// system bus is optional
d.system = system != nil
d.sessionBus[0], d.systemBus[0] = dbus.Address()
d.sessionBus[1], d.systemBus[1] = sessionPath, systemPath
d.out = &linePrefixWriter{println: log.Println, prefix: "(dbus) ", msg: new(strings.Builder)}
if final, err := dbus.Finalise(d.sessionBus, d.systemBus, session, system); err != nil {
if errors.Is(err, syscall.EINVAL) {
return nil, newOpErrorMessage("dbus", err,
"message bus proxy configuration contains NUL byte", false)
}
return nil, newOpErrorMessage("dbus", err,
fmt.Sprintf("cannot finalise message bus proxy: %v", err), false)
} else {
if msg.IsVerbose() {
msg.Verbose("session bus proxy:", session.Args(d.sessionBus))
if system != nil {
msg.Verbose("system bus proxy:", system.Args(d.systemBus))
}
// this calls the argsWt String method
msg.Verbose("message bus proxy final args:", final.WriterTo)
}
d.final = final
}
sys.ops = append(sys.ops, d)
return d.out.Dump, nil
}
// DBusProxyOp starts xdg-dbus-proxy via [dbus] and terminates it on revert.
// This [Op] is always [Process] scoped.
type DBusProxyOp struct {
proxy *dbus.Proxy // populated during apply
final *dbus.Final
out *linePrefixWriter
// whether system bus proxy is enabled
system bool
sessionBus, systemBus dbus.ProxyPair
}
func (d *DBusProxyOp) Type() Enablement { return Process }
func (d *DBusProxyOp) apply(sys *I) error {
msg.Verbosef("session bus proxy on %q for upstream %q", d.sessionBus[1], d.sessionBus[0])
if d.system {
msg.Verbosef("system bus proxy on %q for upstream %q", d.systemBus[1], d.systemBus[0])
}
d.proxy = dbus.New(sys.ctx, d.final, d.out)
if err := d.proxy.Start(); err != nil {
d.out.Dump()
return newOpErrorMessage("dbus", err,
fmt.Sprintf("cannot start message bus proxy: %v", err), false)
}
msg.Verbose("starting message bus proxy", d.proxy)
return nil
}
func (d *DBusProxyOp) revert(*I, *Criteria) error {
// criteria ignored here since dbus is always process-scoped
msg.Verbose("terminating message bus proxy")
d.proxy.Close()
defer msg.Verbose("message bus proxy exit")
err := d.proxy.Wait()
if errors.Is(err, context.Canceled) {
msg.Verbose("message bus proxy canceled upstream")
err = nil
}
return newOpErrorMessage("dbus", err,
fmt.Sprintf("message bus proxy error: %v", err), true)
}
func (d *DBusProxyOp) Is(o Op) bool {
target, ok := o.(*DBusProxyOp)
return ok && d != nil && target != nil &&
((d.proxy == nil && target.proxy == nil) ||
(d.proxy != nil && target.proxy != nil &&
d.proxy.String() == target.proxy.String()))
}
func (d *DBusProxyOp) Path() string { return "(dbus proxy)" }
func (d *DBusProxyOp) String() string { return d.proxy.String() }
// linePrefixWriter calls println with a prefix for every line written.
type linePrefixWriter struct {
prefix string
println func(v ...any)
msg *strings.Builder
msgbuf []string
mu sync.RWMutex
}
func (s *linePrefixWriter) Write(p []byte) (n int, err error) {
s.mu.Lock()
defer s.mu.Unlock()
return s.write(p, 0)
}
func (s *linePrefixWriter) write(p []byte, a int) (int, error) {
if i := bytes.IndexByte(p, '\n'); i == -1 {
n, _ := s.msg.Write(p)
return a + n, nil
} else {
n, _ := s.msg.Write(p[:i])
// allow container init messages through
v := s.msg.String()
if strings.HasPrefix(v, "init: ") {
s.println(s.prefix + v)
} else {
s.msgbuf = append(s.msgbuf, v)
}
s.msg.Reset()
return s.write(p[i+1:], a+n+1)
}
}
func (s *linePrefixWriter) Dump() {
s.mu.RLock()
for _, m := range s.msgbuf {
s.println(s.prefix + m)
}
s.mu.RUnlock()
}
|
