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_mac.h" 42 43 #include <sys/param.h> 44 #include <sys/kernel.h> 45 #include <sys/priv.h> 46 #include <sys/sdt.h> 47 #include <sys/module.h> 48 49 #include <security/mac/mac_framework.h> 50 #include <security/mac/mac_internal.h> 51 #include <security/mac/mac_policy.h> 52 53 /* 54 * The MAC Framework interacts with kernel privilege checks in two ways: it 55 * may restrict the granting of privilege to a subject, and it may grant 56 * additional privileges to the subject. Policies may implement none, one, 57 * or both of these entry points. Restriction of privilege by any policy 58 * always overrides granting of privilege by any policy or other privilege 59 * mechanism. See kern_priv.c:priv_check_cred() for details of the 60 * composition. 61 */ 62 63 MAC_CHECK_PROBE_DEFINE2(priv_check, "struct ucred *", "int"); 64 65 /* 66 * Restrict access to a privilege for a credential. Return failure if any 67 * policy denies access. 68 */ 69 int 70 mac_priv_check_impl(struct ucred *cred, int priv) 71 { 72 int error; 73 74 MAC_POLICY_CHECK_NOSLEEP(priv_check, cred, priv); 75 MAC_CHECK_PROBE2(priv_check, error, cred, priv); 76 77 return (error); 78 } 79 80 MAC_GRANT_PROBE_DEFINE2(priv_grant, "struct ucred *", "int"); 81 82 /* 83 * Grant access to a privilege for a credential. Return success if any 84 * policy grants access. 85 */ 86 int 87 mac_priv_grant_impl(struct ucred *cred, int priv) 88 { 89 int error; 90 91 MAC_POLICY_GRANT_NOSLEEP(priv_grant, cred, priv); 92 MAC_GRANT_PROBE2(priv_grant, error, cred, priv); 93 94 return (error); 95 } 96