1 /* Copyright (C) 1993-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <errno.h>
19 #include <sys/types.h>
20 #include <unistd.h>
21 #include <hurd.h>
22 #include <hurd/id.h>
23 #include <string.h>
24
25 int
__setreuid(uid_t ruid,uid_t euid)26 __setreuid (uid_t ruid, uid_t euid)
27 {
28 auth_t newauth;
29 error_t err;
30
31 retry:
32 HURD_CRITICAL_BEGIN;
33 __mutex_lock (&_hurd_id.lock);
34 err = _hurd_check_ids ();
35
36 if (!err)
37 {
38 /* Make a new auth handle which has RUID as the real uid,
39 and EUID as the first element in the list of effective uids. */
40
41 uid_t *newgen, *newaux;
42 size_t ngen, naux;
43
44 newgen = _hurd_id.gen.uids;
45 ngen = _hurd_id.gen.nuids;
46 if (euid != -1)
47 {
48 if (_hurd_id.gen.nuids == 0)
49 {
50 /* No effective uids now. The new set will be just UID. */
51 newgen = &euid;
52 ngen = 1;
53 }
54 else
55 {
56 _hurd_id.gen.uids[0] = euid;
57 _hurd_id.valid = 0;
58 }
59 }
60
61 newaux = _hurd_id.aux.uids;
62 naux = _hurd_id.aux.nuids;
63 if (ruid != -1)
64 {
65 if (_hurd_id.aux.nuids == 0)
66 {
67 newaux = &ruid;
68 naux = 1;
69 }
70 else
71 {
72 _hurd_id.aux.uids[0] = ruid;
73 _hurd_id.valid = 0;
74 }
75 }
76
77 err = __USEPORT (AUTH, __auth_makeauth
78 (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
79 newgen, ngen, newaux, naux,
80 _hurd_id.gen.gids, _hurd_id.gen.ngids,
81 _hurd_id.aux.gids, _hurd_id.aux.ngids,
82 &newauth));
83 }
84 __mutex_unlock (&_hurd_id.lock);
85 HURD_CRITICAL_END;
86 if (err == EINTR)
87 /* Got a signal while inside an RPC of the critical section, retry again */
88 goto retry;
89
90 if (err)
91 return __hurd_fail (err);
92
93 /* Install the new handle and reauthenticate everything. */
94 err = __setauth (newauth);
95 __mach_port_deallocate (__mach_task_self (), newauth);
96 return err;
97 }
98
99 weak_alias (__setreuid, setreuid)
100