1 /* $NetBSD: set_ugid.c,v 1.1.1.1 2009/06/23 10:09:00 tron Exp $ */
2
3 /*++
4 /* NAME
5 /* set_ugid 3
6 /* SUMMARY
7 /* set real, effective and saved user and group attributes
8 /* SYNOPSIS
9 /* #include <set_ugid.h>
10 /*
11 /* void set_ugid(uid, gid)
12 /* uid_t uid;
13 /* gid_t gid;
14 /* DESCRIPTION
15 /* set_ugid() sets the real, effective and saved user and group process
16 /* attributes and updates the process group access list to be just the
17 /* user's primary group. This operation is irreversible.
18 /* DIAGNOSTICS
19 /* All system call errors are fatal.
20 /* SEE ALSO
21 /* setuid(2), setgid(2), setgroups(2)
22 /* LICENSE
23 /* .ad
24 /* .fi
25 /* The Secure Mailer license must be distributed with this software.
26 /* AUTHOR(S)
27 /* Wietse Venema
28 /* IBM T.J. Watson Research
29 /* P.O. Box 704
30 /* Yorktown Heights, NY 10598, USA
31 /*--*/
32
33 /* System library. */
34
35 #include <sys_defs.h>
36 #include <unistd.h>
37 #include <grp.h>
38 #include <errno.h>
39
40 /* Utility library. */
41
42 #include "msg.h"
43 #include "set_ugid.h"
44
45 /* set_ugid - set real, effective and saved user and group attributes */
46
set_ugid(uid_t uid,gid_t gid)47 void set_ugid(uid_t uid, gid_t gid)
48 {
49 int saved_errno = errno;
50
51 if (geteuid() != 0)
52 if (seteuid(0) < 0)
53 msg_fatal("seteuid(0): %m");
54 if (setgid(gid) < 0)
55 msg_fatal("setgid(%ld): %m", (long) gid);
56 if (setgroups(1, &gid) < 0)
57 msg_fatal("setgroups(1, &%ld): %m", (long) gid);
58 if (setuid(uid) < 0)
59 msg_fatal("setuid(%ld): %m", (long) uid);
60 if (msg_verbose > 1)
61 msg_info("setugid: uid %ld gid %ld", (long) uid, (long) gid);
62 errno = saved_errno;
63 }
64