github.com/meulengracht/snapd@v0.0.0-20210719210640-8bde69bcc84e/interfaces/builtin/timeserver_control.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2016 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package builtin
    21  
    22  const timeserverControlSummary = `allows setting system time synchronization servers`
    23  
    24  const timeserverControlBaseDeclarationSlots = `
    25    timeserver-control:
    26      allow-installation:
    27        slot-snap-type:
    28          - core
    29      deny-auto-connection: true
    30  `
    31  
    32  // http://bazaar.launchpad.net/~ubuntu-security/ubuntu-core-security/trunk/view/head:/data/apparmor/policygroups/ubuntu-core/16.04/timeserver-control
    33  const timeserverControlConnectedPlugAppArmor = `
    34  # Description: Can manage timeservers directly separate from config ubuntu-core.
    35  # Can enable system clock NTP synchronization via timedated D-Bus interface,
    36  # Can read all properties of /org/freedesktop/timedate1 D-Bus object; see
    37  # https://www.freedesktop.org/wiki/Software/systemd/timedated/
    38  
    39  #include <abstractions/dbus-strict>
    40  
    41  # Won't work until LP: #1504657 is fixed. Requires reboot until timesyncd
    42  # notices the change or systemd restarts it.
    43  /etc/systemd/timesyncd.conf rw,
    44  
    45  # Introspection of org.freedesktop.timedate1
    46  # do not use peer=(label=unconfined) here since this is DBus activated
    47  dbus (send)
    48      bus=system
    49      path=/org/freedesktop/timedate1
    50      interface=org.freedesktop.DBus.Introspectable
    51      member=Introspect,
    52  
    53  dbus (send)
    54      bus=system
    55      path=/org/freedesktop/timedate1
    56      interface=org.freedesktop.timedate1
    57      member="SetNTP"
    58      peer=(label=unconfined),
    59  
    60  # Read all properties from timedate1
    61  # do not use peer=(label=unconfined) here since this is DBus activated
    62  dbus (send)
    63      bus=system
    64      path=/org/freedesktop/timedate1
    65      interface=org.freedesktop.DBus.Properties
    66      member=Get{,All},
    67  
    68  # Receive timedate1 property changed events
    69  dbus (receive)
    70      bus=system
    71      path=/org/freedesktop/timedate1
    72      interface=org.freedesktop.DBus.Properties
    73      member=PropertiesChanged
    74      peer=(label=unconfined),
    75  
    76  # As the core snap ships the timedatectl utility we can also allow
    77  # clients to use it now that they have access to the relevant
    78  # D-Bus method for controlling network time synchronization via
    79  # timedatectl's set-ntp command.
    80  /usr/bin/timedatectl{,.real} ixr,
    81  
    82  # Silence this noisy denial. systemd utilities look at /proc/1/environ to see
    83  # if running in a container, but they will fallback gracefully. No other
    84  # interfaces allow this denial, so no problems with silencing it for now. Note
    85  # that allowing this triggers a 'ptrace trace peer=unconfined' denial, which we
    86  # want to avoid.
    87  deny @{PROC}/1/environ r,
    88  `
    89  
    90  func init() {
    91  	registerIface(&commonInterface{
    92  		name:                  "timeserver-control",
    93  		summary:               timeserverControlSummary,
    94  		implicitOnCore:        true,
    95  		implicitOnClassic:     true,
    96  		baseDeclarationSlots:  timeserverControlBaseDeclarationSlots,
    97  		connectedPlugAppArmor: timeserverControlConnectedPlugAppArmor,
    98  	})
    99  }