1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2021 Florian Walpen <dev@submerge.ch>
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
28#include <sys/param.h>
29#include <sys/conf.h>
30#include <sys/kernel.h>
31#include <sys/module.h>
32#include <sys/priv.h>
33#include <sys/sysctl.h>
34#include <sys/ucred.h>
35
36#include <security/mac/mac_policy.h>
37
38SYSCTL_DECL(_security_mac);
39
40static SYSCTL_NODE(_security_mac, OID_AUTO, priority,
41    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
42    "mac_priority policy controls");
43
44static int realtime_enabled = 1;
45SYSCTL_INT(_security_mac_priority, OID_AUTO, realtime, CTLFLAG_RWTUN,
46    &realtime_enabled, 0,
47    "Enable realtime priority scheduling for group realtime_gid");
48
49static int realtime_gid = GID_RT_PRIO;
50SYSCTL_INT(_security_mac_priority, OID_AUTO, realtime_gid, CTLFLAG_RWTUN,
51    &realtime_gid, 0,
52    "Group id of the realtime privilege group");
53
54static int idletime_enabled = 1;
55SYSCTL_INT(_security_mac_priority, OID_AUTO, idletime, CTLFLAG_RWTUN,
56    &idletime_enabled, 0,
57    "Enable idle priority scheduling for group idletime_gid");
58
59static int idletime_gid = GID_ID_PRIO;
60SYSCTL_INT(_security_mac_priority, OID_AUTO, idletime_gid, CTLFLAG_RWTUN,
61    &idletime_gid, 0,
62    "Group id of the idletime privilege group");
63
64static int
65priority_priv_grant(struct ucred *cred, int priv)
66{
67	if ((priv == PRIV_SCHED_RTPRIO || priv == PRIV_SCHED_SETPOLICY) &&
68	    realtime_enabled && groupmember(realtime_gid, cred))
69		return (0);
70
71	if (priv == PRIV_SCHED_IDPRIO && idletime_enabled &&
72	    groupmember(idletime_gid, cred))
73		return (0);
74
75	return (EPERM);
76}
77
78static struct mac_policy_ops priority_ops = {
79	.mpo_priv_grant = priority_priv_grant,
80};
81
82MAC_POLICY_SET(&priority_ops, mac_priority, "MAC/priority",
83    MPC_LOADTIME_FLAG_UNLOADOK, NULL);
84