1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2018 Ian Lepore <ian@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#include <sys/param.h>
31#include <sys/kernel.h>
32#include <sys/module.h>
33#include <sys/priv.h>
34#include <sys/sysctl.h>
35#include <sys/ucred.h>
36
37#include <security/mac/mac_policy.h>
38
39SYSCTL_DECL(_security_mac);
40
41static SYSCTL_NODE(_security_mac, OID_AUTO, ntpd,
42    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
43    "mac_ntpd policy controls");
44
45static int ntpd_enabled = 1;
46SYSCTL_INT(_security_mac_ntpd, OID_AUTO, enabled, CTLFLAG_RWTUN,
47    &ntpd_enabled, 0, "Enable mac_ntpd policy");
48
49static int ntpd_uid = 123;
50SYSCTL_INT(_security_mac_ntpd, OID_AUTO, uid, CTLFLAG_RWTUN,
51    &ntpd_uid, 0, "User id for ntpd user");
52
53static int
54ntpd_priv_grant(struct ucred *cred, int priv)
55{
56
57	if (ntpd_enabled && cred->cr_uid == ntpd_uid) {
58		switch (priv) {
59		case PRIV_ADJTIME:
60		case PRIV_CLOCK_SETTIME:
61		case PRIV_NTP_ADJTIME:
62		case PRIV_NETINET_RESERVEDPORT:
63		case PRIV_NETINET_REUSEPORT:
64			return (0);
65		default:
66			break;
67		}
68	}
69	return (EPERM);
70}
71
72static struct mac_policy_ops ntpd_ops =
73{
74	.mpo_priv_grant = ntpd_priv_grant,
75};
76
77MAC_POLICY_SET(&ntpd_ops, mac_ntpd, "MAC/ntpd",
78    MPC_LOADTIME_FLAG_UNLOADOK, NULL);
79