Home | History | Annotate | Line # | Download | only in at
privs.h revision 1.9 
      1 /*	$NetBSD: privs.h,v 1.9 2016/03/13 00:32:09 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  * Relinquish privileges temporarily for a setuid or setgid program
     35  * with the option of getting them back later.  This is done by
     36  * using POSIX saved user and groups ids.  Call RELINQUISH_PRIVS once
     37  * at the beginning of the main program.  This will cause all operations
     38  * to be executed with the real userid.  When you need the privileges
     39  * of the setuid/setgid invocation, call PRIV_START; when you no longer
     40  * need it, call PRIV_END.  Note that it is an error to call PRIV_START
     41  * and not PRIV_END within the same function.
     42  *
     43  * Use RELINQUISH_PRIVS_ROOT(a,b) if your program started out running
     44  * as root, and you want to drop back the effective userid to a
     45  * and the effective group id to b, with the option to get them back
     46  * later.
     47  *
     48  * Problems: Do not use return between PRIV_START and PRIV_END; this
     49  * will cause the program to continue running in an unprivileged
     50  * state.
     51  *
     52  * It is NOT safe to call exec(), system() or popen() with a user-
     53  * supplied program (i.e. without carefully checking PATH and any
     54  * library load paths) with relinquished privileges; the called program
     55  * can acquire them just as easily.  Set both effective and real userid
     56  * to the real userid before calling any of them.
     57  */
     58 
     59 extern uid_t real_uid, effective_uid;
     60 extern gid_t real_gid, effective_gid;
     61 
     62 void privs_relinquish(void);
     63 void privs_relinquish_root(uid_t ruid, gid_t rgid);
     64 
     65 void privs_enter(void);
     66 void privs_exit(void);
     67 
     68 /* caller provides this */
     69 __dead void privs_fail(const char *msg);
     70 
     71 #endif /* _PRIV_H_ */
     72