blob: d48d863264081521c974f70dc5c039c17293303e
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com> |
4 | * All rights reserved. |
5 | * |
6 | * Redistribution and use in source and binary forms, with or without |
7 | * modification, are permitted provided that the following conditions |
8 | * are met: |
9 | * 1. Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * 2. Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
14 | * 3. Neither the name of Julianne F. Haugh nor the names of its contributors |
15 | * may be used to endorse or promote products derived from this software |
16 | * without specific prior written permission. |
17 | * |
18 | * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND |
19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
21 | * ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE |
22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
28 | * SUCH DAMAGE. |
29 | */ |
30 | |
31 | #include "libbb.h" |
32 | |
33 | /* Become the user and group(s) specified by PW. */ |
34 | void FAST_FUNC change_identity(const struct passwd *pw) |
35 | { |
36 | int res; |
37 | |
38 | res = initgroups(pw->pw_name, pw->pw_gid); |
39 | endgrent(); /* helps to close a fd used internally by libc */ |
40 | |
41 | if (res != 0) { |
42 | /* |
43 | * If initgroups() fails because a system call is unimplemented |
44 | * then we are running on a Linux kernel compiled without multiuser |
45 | * support (CONFIG_MULTIUSER is not defined). |
46 | * |
47 | * If we are running without multiuser support *and* the target uid |
48 | * already matches the current uid then we can skip the change of |
49 | * identity. |
50 | */ |
51 | if (errno == ENOSYS && pw->pw_uid == getuid()) { |
52 | return; |
53 | } |
54 | |
55 | bb_perror_msg_and_die("can't set groups"); |
56 | } |
57 | |
58 | xsetgid(pw->pw_gid); |
59 | xsetuid(pw->pw_uid); |
60 | } |
61 |