1 /*- 2 * Copyright (c) 2006 nCircle Network Security, Inc. 3 * Copyright (c) 2009 Robert N. M. Watson 4 * All rights reserved. 5 * 6 * This software was developed by Robert N. M. Watson for the TrustedBSD 7 * Project under contract to nCircle Network Security, Inc. 8 * 9 * This software was developed at the University of Cambridge Computer 10 * Laboratory with support from a grant from Google, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY, 25 * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 27 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 28 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * MAC checks for system privileges. 36 */ 37 38 #include "sys/cdefs.h" 39 __FBSDID("$FreeBSD$"); 40 41 #include "opt_kdtrace.h" 42 #include "opt_mac.h" 43 44 #include <sys/param.h> 45 #include <sys/kernel.h> 46 #include <sys/priv.h> 47 #include <sys/sdt.h> 48 #include <sys/module.h> 49 50 #include <security/mac/mac_framework.h> 51 #include <security/mac/mac_internal.h> 52 #include <security/mac/mac_policy.h> 53 54 /* 55 * The MAC Framework interacts with kernel privilege checks in two ways: it 56 * may restrict the granting of privilege to a subject, and it may grant 57 * additional privileges to the subject. Policies may implement none, one, 58 * or both of these entry points. Restriction of privilege by any policy 59 * always overrides granting of privilege by any policy or other privilege 60 * mechanism. See kern_priv.c:priv_check_cred() for details of the 61 * composition. 62 */ 63 64 MAC_CHECK_PROBE_DEFINE2(priv_check, "struct ucred *", "int"); 65 66 /* 67 * Restrict access to a privilege for a credential. Return failure if any 68 * policy denies access. 69 */ 70 int 71 mac_priv_check(struct ucred *cred, int priv) 72 { 73 int error; 74 75 MAC_POLICY_CHECK_NOSLEEP(priv_check, cred, priv); 76 MAC_CHECK_PROBE2(priv_check, error, cred, priv); 77 78 return (error); 79 } 80 81 MAC_GRANT_PROBE_DEFINE2(priv_grant, "struct ucred *", "int"); 82 83 /* 84 * Grant access to a privilege for a credential. Return success if any 85 * policy grants access. 86 */ 87 int 88 mac_priv_grant(struct ucred *cred, int priv) 89 { 90 int error; 91 92 MAC_POLICY_GRANT_NOSLEEP(priv_grant, cred, priv); 93 MAC_GRANT_PROBE2(priv_grant, error, cred, priv); 94 95 return (error); 96 } 97