nixpkgs/nixos/modules/services/system/dbus.nix
Julian Stecklina be2a4f37af nixos/dbus: explicitly set homeMode for dbus
Otherwise /run/dbus is created with the wrong permissions.

For some reason our recent changes made /run/dbus be 0700 instead of
0755. This is actually the default of homeMode. So something worked by
accident before?
2024-01-18 23:08:14 +01:00

217 lines
5.8 KiB
Nix

# D-Bus configuration and system bus daemon.
{ config, lib, pkgs, ... }:
let
cfg = config.services.dbus;
homeDir = "/run/dbus";
configDir = pkgs.makeDBusConf {
inherit (cfg) apparmor;
suidHelper = "${config.security.wrapperDir}/dbus-daemon-launch-helper";
serviceDirectories = cfg.packages;
};
inherit (lib) mkOption mkEnableOption mkIf mkMerge types;
in
{
options = {
boot.initrd.systemd.dbus = {
enable = mkEnableOption (lib.mdDoc "dbus in stage 1");
};
services.dbus = {
enable = mkOption {
type = types.bool;
default = false;
internal = true;
description = lib.mdDoc ''
Whether to start the D-Bus message bus daemon, which is
required by many other system services and applications.
'';
};
implementation = mkOption {
type = types.enum [ "dbus" "broker" ];
default = "dbus";
description = lib.mdDoc ''
The implementation to use for the message bus defined by the D-Bus specification.
Can be either the classic dbus daemon or dbus-broker, which aims to provide high
performance and reliability, while keeping compatibility to the D-Bus
reference implementation.
'';
};
packages = mkOption {
type = types.listOf types.path;
default = [ ];
description = lib.mdDoc ''
Packages whose D-Bus configuration files should be included in
the configuration of the D-Bus system-wide or session-wide
message bus. Specifically, files in the following directories
will be included into their respective DBus configuration paths:
{file}`«pkg»/etc/dbus-1/system.d`
{file}`«pkg»/share/dbus-1/system.d`
{file}`«pkg»/share/dbus-1/system-services`
{file}`«pkg»/etc/dbus-1/session.d`
{file}`«pkg»/share/dbus-1/session.d`
{file}`«pkg»/share/dbus-1/services`
'';
};
apparmor = mkOption {
type = types.enum [ "enabled" "disabled" "required" ];
description = lib.mdDoc ''
AppArmor mode for dbus.
`enabled` enables mediation when it's
supported in the kernel, `disabled`
always disables AppArmor even with kernel support, and
`required` fails when AppArmor was not found
in the kernel.
'';
default = "disabled";
};
};
};
config = mkIf cfg.enable (mkMerge [
{
environment.etc."dbus-1".source = configDir;
environment.pathsToLink = [
"/etc/dbus-1"
"/share/dbus-1"
];
users.users.messagebus = {
uid = config.ids.uids.messagebus;
description = "D-Bus system message bus daemon user";
home = homeDir;
homeMode = "0755";
group = "messagebus";
};
users.groups.messagebus.gid = config.ids.gids.messagebus;
# You still need the dbus reference implementation installed to use dbus-broker
systemd.packages = [
pkgs.dbus
];
services.dbus.packages = [
pkgs.dbus
config.system.path
];
systemd.user.sockets.dbus.wantedBy = [
"sockets.target"
];
}
(mkIf config.boot.initrd.systemd.dbus.enable {
boot.initrd.systemd = {
users.messagebus = { };
groups.messagebus = { };
contents."/etc/dbus-1".source = pkgs.makeDBusConf {
inherit (cfg) apparmor;
suidHelper = "/bin/false";
serviceDirectories = [ pkgs.dbus ];
};
packages = [ pkgs.dbus ];
storePaths = [ "${pkgs.dbus}/bin/dbus-daemon" ];
targets.sockets.wants = [ "dbus.socket" ];
};
})
(mkIf (cfg.implementation == "dbus") {
environment.systemPackages = [
pkgs.dbus
];
security.wrappers.dbus-daemon-launch-helper = {
source = "${pkgs.dbus}/libexec/dbus-daemon-launch-helper";
owner = "root";
group = "messagebus";
setuid = true;
setgid = false;
permissions = "u+rx,g+rx,o-rx";
};
systemd.services.dbus = {
# Don't restart dbus-daemon. Bad things tend to happen if we do.
reloadIfChanged = true;
restartTriggers = [
configDir
];
environment = {
LD_LIBRARY_PATH = config.system.nssModules.path;
};
};
systemd.user.services.dbus = {
# Don't restart dbus-daemon. Bad things tend to happen if we do.
reloadIfChanged = true;
restartTriggers = [
configDir
];
};
})
(mkIf (cfg.implementation == "broker") {
environment.systemPackages = [
pkgs.dbus-broker
];
systemd.packages = [
pkgs.dbus-broker
];
# Just to be sure we don't restart through the unit alias
systemd.services.dbus.reloadIfChanged = true;
systemd.user.services.dbus.reloadIfChanged = true;
# NixOS Systemd Module doesn't respect 'Install'
# https://github.com/NixOS/nixpkgs/issues/108643
systemd.services.dbus-broker = {
aliases = [
"dbus.service"
];
unitConfig = {
# We get errors when reloading the dbus-broker service
# if /tmp got remounted after this service started
RequiresMountsFor = [ "/tmp" ];
};
# Don't restart dbus. Bad things tend to happen if we do.
reloadIfChanged = true;
restartTriggers = [
configDir
];
environment = {
LD_LIBRARY_PATH = config.system.nssModules.path;
};
};
systemd.user.services.dbus-broker = {
aliases = [
"dbus.service"
];
# Don't restart dbus. Bad things tend to happen if we do.
reloadIfChanged = true;
restartTriggers = [
configDir
];
};
})
]);
}