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|
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.usbguard;
# valid policy options
policy = (types.enum [ "allow" "block" "reject" "keep" "apply-policy" ]);
defaultRuleFile = "/var/lib/usbguard/rules.conf";
# decide what file to use for rules
ruleFile = if cfg.rules != null then pkgs.writeText "usbguard-rules" cfg.rules else defaultRuleFile;
daemonConf = ''
# generated by nixos/modules/services/security/usbguard.nix
RuleFile=${ruleFile}
ImplicitPolicyTarget=${cfg.implictPolicyTarget}
PresentDevicePolicy=${cfg.presentDevicePolicy}
PresentControllerPolicy=${cfg.presentControllerPolicy}
InsertedDevicePolicy=${cfg.insertedDevicePolicy}
RestoreControllerDeviceState=${boolToString cfg.restoreControllerDeviceState}
# this does not seem useful for endusers to change
DeviceManagerBackend=uevent
IPCAllowedUsers=${concatStringsSep " " cfg.IPCAllowedUsers}
IPCAllowedGroups=${concatStringsSep " " cfg.IPCAllowedGroups}
IPCAccessControlFiles=/var/lib/usbguard/IPCAccessControl.d/
DeviceRulesWithPort=${boolToString cfg.deviceRulesWithPort}
# HACK: that way audit logs still land in the journal
AuditFilePath=/dev/null
'';
daemonConfFile = pkgs.writeText "usbguard-daemon-conf" daemonConf;
in
{
###### interface
options = {
services.usbguard = {
enable = mkEnableOption "USBGuard daemon";
package = mkOption {
type = types.package;
default = pkgs.usbguard;
defaultText = literalExpression "pkgs.usbguard";
description = ''
The usbguard package to use. If you do not need the Qt GUI, use
<literal>pkgs.usbguard-nox</literal> to save disk space.
'';
};
rules = mkOption {
type = types.nullOr types.lines;
default = null;
example = ''
allow with-interface equals { 08:*:* }
'';
description = ''
The USBGuard daemon will load this as the policy rule set.
As these rules are NixOS managed they are immutable and can't
be changed by the IPC interface.
If you do not set this option, the USBGuard daemon will load
it's policy rule set from <literal>${defaultRuleFile}</literal>.
This file can be changed manually or via the IPC interface.
Running <literal>usbguard generate-policy</literal> as root will
generate a config for your currently plugged in devices.
For more details see <citerefentry>
<refentrytitle>usbguard-rules.conf</refentrytitle>
<manvolnum>5</manvolnum></citerefentry>.
'';
};
implictPolicyTarget = mkOption {
type = policy;
default = "block";
description = ''
How to treat USB devices that don't match any rule in the policy.
Target should be one of allow, block or reject (logically remove the
device node from the system).
'';
};
presentDevicePolicy = mkOption {
type = policy;
default = "apply-policy";
description = ''
How to treat USB devices that are already connected when the daemon
starts. Policy should be one of allow, block, reject, keep (keep
whatever state the device is currently in) or apply-policy (evaluate
the rule set for every present device).
'';
};
presentControllerPolicy = mkOption {
type = policy;
default = "keep";
description = ''
How to treat USB controller devices that are already connected when
the daemon starts. One of allow, block, reject, keep or apply-policy.
'';
};
insertedDevicePolicy = mkOption {
type = policy;
default = "apply-policy";
description = ''
How to treat USB devices that are already connected after the daemon
starts. One of block, reject, apply-policy.
'';
};
restoreControllerDeviceState = mkOption {
type = types.bool;
default = false;
description = ''
The USBGuard daemon modifies some attributes of controller
devices like the default authorization state of new child device
instances. Using this setting, you can controll whether the daemon
will try to restore the attribute values to the state before
modificaton on shutdown.
'';
};
IPCAllowedUsers = mkOption {
type = types.listOf types.str;
default = [ "root" ];
example = [ "root" "yourusername" ];
description = ''
A list of usernames that the daemon will accept IPC connections from.
'';
};
IPCAllowedGroups = mkOption {
type = types.listOf types.str;
default = [ ];
example = [ "wheel" ];
description = ''
A list of groupnames that the daemon will accept IPC connections
from.
'';
};
deviceRulesWithPort = mkOption {
type = types.bool;
default = false;
description = ''
Generate device specific rules including the "via-port" attribute.
'';
};
};
};
###### implementation
config = mkIf cfg.enable {
environment.systemPackages = [ cfg.package ];
systemd.services.usbguard = {
description = "USBGuard daemon";
wantedBy = [ "basic.target" ];
wants = [ "systemd-udevd.service" ];
# make sure an empty rule file exists
preStart = ''[ -f "${ruleFile}" ] || touch ${ruleFile}'';
serviceConfig = {
Type = "simple";
ExecStart = "${cfg.package}/bin/usbguard-daemon -P -k -c ${daemonConfFile}";
Restart = "on-failure";
StateDirectory = [
"usbguard"
"usbguard/IPCAccessControl.d"
];
AmbientCapabilities = "";
CapabilityBoundingSet = "CAP_CHOWN CAP_FOWNER";
DeviceAllow = "/dev/null rw";
DevicePolicy = "strict";
IPAddressDeny = "any";
LockPersonality = true;
MemoryDenyWriteExecute = true;
NoNewPrivileges = true;
PrivateDevices = true;
PrivateTmp = true;
ProtectControlGroups = true;
ProtectHome = true;
ProtectKernelModules = true;
ProtectSystem = true;
ReadOnlyPaths = "-/";
ReadWritePaths = "-/dev/shm -/tmp";
RestrictAddressFamilies = [ "AF_UNIX" "AF_NETLINK" ];
RestrictNamespaces = true;
RestrictRealtime = true;
SystemCallArchitectures = "native";
SystemCallFilter = "@system-service";
UMask = "0077";
};
};
};
imports = [
(mkRemovedOptionModule [ "services" "usbguard" "ruleFile" ] "The usbguard module now uses ${defaultRuleFile} as ruleFile. Alternatively, use services.usbguard.rules to configure rules.")
(mkRemovedOptionModule [ "services" "usbguard" "IPCAccessControlFiles" ] "The usbguard module now hardcodes IPCAccessControlFiles to /var/lib/usbguard/IPCAccessControl.d.")
(mkRemovedOptionModule [ "services" "usbguard" "auditFilePath" ] "Removed usbguard module audit log files. Audit logs can be found in the systemd journal.")
];
}
|