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 28 #include <sys/param.h> 29 #include <sys/kernel.h> 30 #include <sys/module.h> 31 #include <sys/priv.h> 32 #include <sys/sysctl.h> 33 #include <sys/ucred.h> 34 35 #include <security/mac/mac_policy.h> 36 37 SYSCTL_DECL(_security_mac); 38 39 static SYSCTL_NODE(_security_mac, OID_AUTO, ntpd, 40 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 41 "mac_ntpd policy controls"); 42 43 static int ntpd_enabled = 1; 44 SYSCTL_INT(_security_mac_ntpd, OID_AUTO, enabled, CTLFLAG_RWTUN, 45 &ntpd_enabled, 0, "Enable mac_ntpd policy"); 46 47 static int ntpd_uid = 123; 48 SYSCTL_INT(_security_mac_ntpd, OID_AUTO, uid, CTLFLAG_RWTUN, 49 &ntpd_uid, 0, "User id for ntpd user"); 50 51 static int 52 ntpd_priv_grant(struct ucred *cred, int priv) 53 { 54 55 if (ntpd_enabled && cred->cr_uid == ntpd_uid) { 56 switch (priv) { 57 case PRIV_ADJTIME: 58 case PRIV_CLOCK_SETTIME: 59 case PRIV_NTP_ADJTIME: 60 case PRIV_NETINET_RESERVEDPORT: 61 case PRIV_NETINET_REUSEPORT: 62 return (0); 63 default: 64 break; 65 } 66 } 67 return (EPERM); 68 } 69 70 static struct mac_policy_ops ntpd_ops = 71 { 72 .mpo_priv_grant = ntpd_priv_grant, 73 }; 74 75 MAC_POLICY_SET(&ntpd_ops, mac_ntpd, "MAC/ntpd", 76 MPC_LOADTIME_FLAG_UNLOADOK, NULL); 77