1 | /* Copyright (C) 1991-2022 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 <unistd.h> |
20 | #include <sys/types.h> |
21 | #include <hurd.h> |
22 | #include <hurd/id.h> |
23 | #include <string.h> |
24 | |
25 | /* Set the group ID of the calling process to UID. |
26 | If the calling process is the super-user, the real |
27 | and effective group IDs, and the saved set-group-ID to UID; |
28 | if not, the effective group ID is set to GID. */ |
29 | int |
30 | __setgid (gid_t gid) |
31 | { |
32 | auth_t newauth; |
33 | error_t err; |
34 | |
35 | retry: |
36 | HURD_CRITICAL_BEGIN; |
37 | __mutex_lock (&_hurd_id.lock); |
38 | err = _hurd_check_ids (); |
39 | |
40 | if (!err) |
41 | { |
42 | /* Make a new auth handle which has GID as the real gid, |
43 | and as the first element in the list of effective gids. */ |
44 | |
45 | gid_t *newgen, *newaux, auxbuf[2]; |
46 | size_t ngen, naux; |
47 | |
48 | if (_hurd_id.gen.ngids == 0) |
49 | { |
50 | /* No effective gids now. The new set will be just GID. */ |
51 | newgen = &gid; |
52 | ngen = 1; |
53 | } |
54 | else |
55 | { |
56 | _hurd_id.gen.gids[0] = gid; |
57 | _hurd_id.valid = 0; |
58 | newgen = _hurd_id.gen.gids; |
59 | ngen = _hurd_id.gen.ngids; |
60 | } |
61 | |
62 | newaux = _hurd_id.aux.gids; |
63 | naux = _hurd_id.aux.ngids; |
64 | if (_hurd_id.gen.nuids > 0 && _hurd_id.gen.uids[0] == 0) |
65 | { |
66 | /* We are root; set the real and saved IDs too. */ |
67 | _hurd_id.valid = 0; |
68 | if (_hurd_id.aux.ngids < 2) |
69 | { |
70 | newaux = auxbuf; |
71 | naux = 2; |
72 | } |
73 | newaux[0] = newaux[1] = gid; |
74 | } |
75 | |
76 | err = __USEPORT (AUTH, __auth_makeauth |
77 | (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0, |
78 | _hurd_id.gen.uids, _hurd_id.gen.nuids, |
79 | _hurd_id.aux.uids, _hurd_id.aux.nuids, |
80 | newgen, ngen, newaux, naux, |
81 | &newauth)); |
82 | } |
83 | __mutex_unlock (&_hurd_id.lock); |
84 | HURD_CRITICAL_END; |
85 | if (err == EINTR) |
86 | /* Got a signal while inside an RPC of the critical section, retry again */ |
87 | goto retry; |
88 | |
89 | if (err) |
90 | return __hurd_fail (err); |
91 | |
92 | /* Install the new handle and reauthenticate everything. */ |
93 | err = __setauth (newauth); |
94 | __mach_port_deallocate (__mach_task_self (), newauth); |
95 | return err; |
96 | } |
97 | |
98 | weak_alias (__setgid, setgid) |
99 | |