2 e2764fac 2022-09-30 op * Copyright (c) 2004, 2005 Darren Tucker (dtucker at zip com au).
4 e2764fac 2022-09-30 op * Permission to use, copy, modify, and distribute this software for any
5 e2764fac 2022-09-30 op * purpose with or without fee is hereby granted, provided that the above
6 e2764fac 2022-09-30 op * copyright notice and this permission notice appear in all copies.
8 e2764fac 2022-09-30 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 e2764fac 2022-09-30 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 e2764fac 2022-09-30 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 e2764fac 2022-09-30 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 e2764fac 2022-09-30 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 e2764fac 2022-09-30 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 e2764fac 2022-09-30 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 e2764fac 2022-09-30 op #include <sys/types.h>
19 e2764fac 2022-09-30 op #include <errno.h>
20 e2764fac 2022-09-30 op #include <unistd.h>
23 e2764fac 2022-09-30 op setresuid(uid_t ruid, uid_t euid, uid_t suid)
28 e2764fac 2022-09-30 op /* Allow only the tested configuration. */
30 e2764fac 2022-09-30 op if (ruid != euid || euid != suid) {
31 e2764fac 2022-09-30 op errno = ENOSYS;
34 e2764fac 2022-09-30 op ouid = getuid();
36 e2764fac 2022-09-30 op if ((ret = setreuid(euid, euid)) == -1)
40 e2764fac 2022-09-30 op * When real, effective and saved uids are the same and we have
41 e2764fac 2022-09-30 op * changed uids, sanity check that we cannot restore the old uid.
44 e2764fac 2022-09-30 op if (ruid == euid && euid == suid && ouid != ruid &&
45 e2764fac 2022-09-30 op setuid(ouid) != -1 && seteuid(ouid) != -1) {
46 e2764fac 2022-09-30 op errno = EINVAL;
51 e2764fac 2022-09-30 op * Finally, check that the real and effective uids are what we
54 e2764fac 2022-09-30 op if (getuid() != ruid || geteuid() != euid) {
55 e2764fac 2022-09-30 op errno = EACCES;