sys/security/mac_priority/mac_priority.c

   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
  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);