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
38 SYSCTL_DECL(_security_mac);
39
40 static SYSCTL_NODE(_security_mac, OID_AUTO, priority,
41 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
42 "mac_priority policy controls");
43
44 static int realtime_enabled = 1;
45 SYSCTL_INT(_security_mac_priority, OID_AUTO, realtime, CTLFLAG_RWTUN,
46 &realtime_enabled, 0,
47 "Enable realtime priority scheduling for group realtime_gid");
48
49 static int realtime_gid = GID_RT_PRIO;
50 SYSCTL_INT(_security_mac_priority, OID_AUTO, realtime_gid, CTLFLAG_RWTUN,
51 &realtime_gid, 0,
52 "Group id of the realtime privilege group");
53
54 static int idletime_enabled = 1;
55 SYSCTL_INT(_security_mac_priority, OID_AUTO, idletime, CTLFLAG_RWTUN,
56 &idletime_enabled, 0,
57 "Enable idle priority scheduling for group idletime_gid");
58
59 static int idletime_gid = GID_ID_PRIO;
60 SYSCTL_INT(_security_mac_priority, OID_AUTO, idletime_gid, CTLFLAG_RWTUN,
61 &idletime_gid, 0,
62 "Group id of the idletime privilege group");
63
64 static int
priority_priv_grant(struct ucred * cred,int priv)65 priority_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
78 static struct mac_policy_ops priority_ops = {
79 .mpo_priv_grant = priority_priv_grant,
80 };
81
82 MAC_POLICY_SET(&priority_ops, mac_priority, "MAC/priority",
83 MPC_LOADTIME_FLAG_UNLOADOK, NULL);
84