/
display_control.go
136 lines (118 loc) · 3.81 KB
/
display_control.go
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// -*- Mode: Go; indent-tabs-mode: t -*-
/*
* Copyright (C) 2019 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package builtin
import (
"bytes"
"fmt"
"path"
"path/filepath"
"github.com/snapcore/snapd/interfaces"
"github.com/snapcore/snapd/interfaces/apparmor"
)
const displayControlSummary = `allows configuring display parameters`
const displayControlBaseDeclarationSlots = `
display-control:
allow-installation:
slot-snap-type:
- core
deny-auto-connection: true
`
// gnome-settings-daemon also provides an API via setting the Brightness
// property via a Set() method on the org.gnome.SettingsDaemon.Power.Screen
// interface, but we can't mediate member data. This could instead be supported
// via userd...
const displayControlConnectedPlugAppArmor = `
# Description: This interface allows getting information about a connected
# display and setting parameters like backlight brightness.
# keyboard backlight key
/sys/class/leds/ r,
/sys/devices/**/leds/**kbd_backlight/{,**} r,
/sys/devices/**/leds/**kbd_backlight/brightness w,
# upower
#include <abstractions/dbus-strict>
dbus (send)
bus=system
path=/org/freedesktop/UPower/KbdBacklight
interface=org.freedesktop.DBus.Introspectable
member=Introspect
peer=(label=unconfined),
dbus (send)
bus=system
path=/org/freedesktop/UPower/KbdBacklight
interface=org.freedesktop.UPower.KbdBacklight
member={GetBrightness,GetMaxBrightness,SetBrightness}
peer=(label=unconfined),
# gnome-settings-daemon
#include <abstractions/dbus-session-strict>
dbus (send)
bus=session
path=/org/gnome/SettingsDaemon/Power
interface=org.freedesktop.DBus.Introspectable
member=Introspect
peer=(label=unconfined),
dbus (send)
bus=session
path=/org/gnome/SettingsDaemon/Power
interface=org.gnome.SettingsDaemon.Power.Screen
member=Step{Down,Up}
peer=(label=unconfined),
/sys/class/backlight/ r,
`
type displayControlInterface struct {
commonInterface
}
func (iface *displayControlInterface) dereferencedBacklightPaths() []string {
var paths []string
sysClass := "/sys/class/backlight"
dirs, err := readDir(sysClass)
if err != nil {
return paths
}
for _, s := range dirs {
p, err := evalSymlinks(filepath.Join(sysClass, s.Name()))
if err != nil {
continue
}
paths = append(paths, filepath.Clean(p))
}
return paths
}
func (iface *displayControlInterface) AppArmorConnectedPlug(spec *apparmor.Specification, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error {
// add the static rules
spec.AddSnippet(displayControlConnectedPlugAppArmor)
// add the detected rules
for _, p := range iface.dereferencedBacklightPaths() {
var buf bytes.Buffer
fmt.Fprintf(&buf, "# autodetected backlight: %s\n", path.Base(p))
fmt.Fprintf(&buf, "%s/{,**} r,\n", p)
fmt.Fprintf(&buf, "%s/bl_power w,\n", p)
fmt.Fprintf(&buf, "%s/brightness w,\n", p)
spec.AddSnippet(buf.String())
}
return nil
}
func init() {
registerIface(&displayControlInterface{commonInterface{
name: "display-control",
summary: displayControlSummary,
implicitOnCore: true,
implicitOnClassic: true,
baseDeclarationSlots: displayControlBaseDeclarationSlots,
connectedPlugAppArmor: displayControlConnectedPlugAppArmor,
}})
}