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// -*- Mode: Go; indent-tabs-mode: t -*-
/*
* Copyright (C) 2017 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 (
"strings"
"github.com/snapcore/snapd/interfaces"
"github.com/snapcore/snapd/interfaces/apparmor"
"github.com/snapcore/snapd/interfaces/dbus"
"github.com/snapcore/snapd/snap"
)
const avahiControlBaseDeclarationSlots = `
avahi-control:
allow-installation:
slot-snap-type:
- app
- core
deny-auto-connection: true
deny-connection:
on-classic: false
`
const avahiControlSummary = `allows control over service discovery on a local network via the mDNS/DNS-SD protocol suite`
const avahiControlConnectedSlotAppArmor = `
# Description: allows configuration of service discovery via mDNS/DNS-SD
# EntryGroup
dbus (receive)
bus=system
path=/Client*/EntryGroup*
interface=org.freedesktop.Avahi.EntryGroup
peer=(label=###PLUG_SECURITY_TAGS###),
dbus (send)
bus=system
interface=org.freedesktop.Avahi.EntryGroup
member=StateChanged
peer=(name=org.freedesktop.Avahi, label=###PLUG_SECURITY_TAGS###),
`
const avahiControlConnectedPlugAppArmor = `
dbus (send)
bus=system
path=/
interface=org.freedesktop.Avahi.Server
member=Set*
peer=(name=org.freedesktop.Avahi,label=###SLOT_SECURITY_TAGS###),
# EntryGroup
dbus (send)
bus=system
path=/
interface=org.freedesktop.Avahi.Server
member=EntryGroupNew
peer=(name=org.freedesktop.Avahi, label=###SLOT_SECURITY_TAGS###),
dbus (send)
bus=system
path=/Client*/EntryGroup*
interface=org.freedesktop.Avahi.EntryGroup
member={Free,Commit,Reset}
peer=(name=org.freedesktop.Avahi, label=###SLOT_SECURITY_TAGS###),
dbus (send)
bus=system
path=/Client*/EntryGroup*
interface=org.freedesktop.Avahi.EntryGroup
member={GetState,IsEmpty,UpdateServiceTxt}
peer=(name=org.freedesktop.Avahi, label=###SLOT_SECURITY_TAGS###),
dbus (send)
bus=system
path=/Client*/EntryGroup*
interface=org.freedesktop.Avahi.EntryGroup
member=Add{Service,ServiceSubtype,Address,Record}
peer=(name=org.freedesktop.Avahi, label=###SLOT_SECURITY_TAGS###),
dbus (receive)
bus=system
path=/Client*/EntryGroup*
interface=org.freedesktop.Avahi.EntryGroup
peer=(label=###SLOT_SECURITY_TAGS###),
`
type avahiControlInterface struct{}
func (iface *avahiControlInterface) Name() string {
return "avahi-control"
}
func (iface *avahiControlInterface) StaticInfo() interfaces.StaticInfo {
return interfaces.StaticInfo{
Summary: avahiControlSummary,
ImplicitOnClassic: true,
BaseDeclarationSlots: avahiControlBaseDeclarationSlots,
}
}
func (iface *avahiControlInterface) AppArmorConnectedPlug(spec *apparmor.Specification, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error {
old := "###SLOT_SECURITY_TAGS###"
var new string
// If we're running on classic, Avahi may be installed either as a snap of
// as part of the OS. If it is part of the OS, it will not have a security
// label like it would when installed as a snap.
if implicitSystemConnectedSlot(slot) {
// avahi from the OS is typically unconfined but known to sometimes be confined
// with stock apparmor 2.13.2+ profiles the label is avahi-daemon
new = "\"{unconfined,/usr/sbin/avahi-daemon,avahi-daemon}\""
} else {
new = slotAppLabelExpr(slot)
}
// avahi-control implies avahi-observe, so add snippets for both here
snippet := strings.Replace(avahiObserveConnectedPlugAppArmor, old, new, -1)
spec.AddSnippet(snippet)
snippet = strings.Replace(avahiControlConnectedPlugAppArmor, old, new, -1)
spec.AddSnippet(snippet)
return nil
}
func (iface *avahiControlInterface) AppArmorPermanentSlot(spec *apparmor.Specification, slot *snap.SlotInfo) error {
// Only apply slot snippet when running as application snap
// on classic, slot side can be system or application
if !implicitSystemPermanentSlot(slot) {
// NOTE: this is using avahi-observe permanent slot as it contains
// base declarations for running as the avahi service.
spec.AddSnippet(avahiObservePermanentSlotAppArmor)
}
return nil
}
func (iface *avahiControlInterface) AppArmorConnectedSlot(spec *apparmor.Specification, plug *interfaces.ConnectedPlug, slot *interfaces.ConnectedSlot) error {
// Only apply slot snippet when running as application snap
// on classic, slot side can be system or application
if !implicitSystemConnectedSlot(slot) {
old := "###PLUG_SECURITY_TAGS###"
new := plugAppLabelExpr(plug)
// avahi-control implies avahi-observe, so add snippets for both here
snippet := strings.Replace(avahiObserveConnectedSlotAppArmor, old, new, -1)
spec.AddSnippet(snippet)
snippet = strings.Replace(avahiControlConnectedSlotAppArmor, old, new, -1)
spec.AddSnippet(snippet)
}
return nil
}
func (iface *avahiControlInterface) DBusPermanentSlot(spec *dbus.Specification, slot *snap.SlotInfo) error {
// Only apply slot snippet when running as application snap
// on classic, slot side can be system or application
if !implicitSystemPermanentSlot(slot) {
// NOTE: this is using avahi-observe permanent slot as it contains
// base declarations for running as the avahi service.
spec.AddSnippet(avahiObservePermanentSlotDBus)
}
return nil
}
func (iface *avahiControlInterface) AutoConnect(*snap.PlugInfo, *snap.SlotInfo) bool {
// allow what declarations allowed
return true
}
func init() {
registerIface(&avahiControlInterface{})
}
|
