1 /* $NetBSD: privs.h,v 1.10 2016/03/13 00:33:12 dholland Exp $ */ 2 3 /* 4 * privs.h - header for privileged operations 5 * Copyright (C) 1993 Thomas Koenig 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. The name of the author(s) may not be used to endorse or promote 13 * products derived from this software without specific prior written 14 * permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * From: OpenBSD: privs.h,v 1.4 1997/03/01 23:40:12 millert Exp 28 */ 29 30 #ifndef _PRIVS_H_ 31 #define _PRIVS_H_ 32 33 /* 34 * Used by: usr.bin/at 35 * Used by: libexec/atrun 36 */ 37 38 /* 39 * Relinquish privileges temporarily for a setuid or setgid program 40 * with the option of getting them back later. This is done by 41 * using POSIX saved user and groups ids. Call RELINQUISH_PRIVS once 42 * at the beginning of the main program. This will cause all operations 43 * to be executed with the real userid. When you need the privileges 44 * of the setuid/setgid invocation, call PRIV_START; when you no longer 45 * need it, call PRIV_END. Note that it is an error to call PRIV_START 46 * and not PRIV_END within the same function. 47 * 48 * Use RELINQUISH_PRIVS_ROOT(a,b) if your program started out running 49 * as root, and you want to drop back the effective userid to a 50 * and the effective group id to b, with the option to get them back 51 * later. 52 * 53 * Problems: Do not use return between PRIV_START and PRIV_END; this 54 * will cause the program to continue running in an unprivileged 55 * state. 56 * 57 * It is NOT safe to call exec(), system() or popen() with a user- 58 * supplied program (i.e. without carefully checking PATH and any 59 * library load paths) with relinquished privileges; the called program 60 * can acquire them just as easily. Set both effective and real userid 61 * to the real userid before calling any of them. 62 */ 63 64 extern uid_t real_uid, effective_uid; 65 extern gid_t real_gid, effective_gid; 66 67 void privs_relinquish(void); 68 void privs_relinquish_root(uid_t ruid, gid_t rgid); 69 70 void privs_enter(void); 71 void privs_exit(void); 72 73 /* caller provides this */ 74 __dead void privs_fail(const char *msg); 75 76 #endif /* _PRIV_H_ */ 77