2 ab1569ee 2023-05-06 op * Copyright (c) 2004, 2005 Darren Tucker (dtucker at zip com au).
4 ab1569ee 2023-05-06 op * Permission to use, copy, modify, and distribute this software for any
5 ab1569ee 2023-05-06 op * purpose with or without fee is hereby granted, provided that the above
6 ab1569ee 2023-05-06 op * copyright notice and this permission notice appear in all copies.
8 ab1569ee 2023-05-06 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 ab1569ee 2023-05-06 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 ab1569ee 2023-05-06 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 ab1569ee 2023-05-06 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 ab1569ee 2023-05-06 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 ab1569ee 2023-05-06 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 ab1569ee 2023-05-06 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 ab1569ee 2023-05-06 op #include <sys/types.h>
19 ab1569ee 2023-05-06 op #include <errno.h>
20 ab1569ee 2023-05-06 op #include <unistd.h>
23 ab1569ee 2023-05-06 op setresuid(uid_t ruid, uid_t euid, uid_t suid)
28 ab1569ee 2023-05-06 op /* Allow only the tested configuration. */
30 ab1569ee 2023-05-06 op if (ruid != euid || euid != suid) {
31 ab1569ee 2023-05-06 op errno = ENOSYS;
34 ab1569ee 2023-05-06 op ouid = getuid();
36 ab1569ee 2023-05-06 op if ((ret = setreuid(euid, euid)) == -1)
40 ab1569ee 2023-05-06 op * When real, effective and saved uids are the same and we have
41 ab1569ee 2023-05-06 op * changed uids, sanity check that we cannot restore the old uid.
44 ab1569ee 2023-05-06 op if (ruid == euid && euid == suid && ouid != ruid &&
45 ab1569ee 2023-05-06 op setuid(ouid) != -1 && seteuid(ouid) != -1) {
46 ab1569ee 2023-05-06 op errno = EINVAL;
51 ab1569ee 2023-05-06 op * Finally, check that the real and effective uids are what we
54 ab1569ee 2023-05-06 op if (getuid() != ruid || geteuid() != euid) {
55 ab1569ee 2023-05-06 op errno = EACCES;