1 | /* setresgid -- set real group ID, effective group ID, and saved-set group ID |
2 | Copyright (C) 2002-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <errno.h> |
20 | #include <unistd.h> |
21 | #include <hurd.h> |
22 | #include <hurd/id.h> |
23 | |
24 | /* Set the real group ID, effective group ID, and saved-set group ID, |
25 | of the calling process to RGID, EGID, and SGID, respectively. */ |
26 | int |
27 | __setresgid (gid_t rgid, gid_t egid, gid_t sgid) |
28 | { |
29 | auth_t newauth; |
30 | error_t err; |
31 | |
32 | retry: |
33 | HURD_CRITICAL_BEGIN; |
34 | __mutex_lock (&_hurd_id.lock); |
35 | err = _hurd_check_ids (); |
36 | |
37 | if (!err) |
38 | { |
39 | /* Make a new auth handle which has EGID as the first element in the |
40 | list of effective gids. */ |
41 | |
42 | uid_t *newgen, *newaux; |
43 | uid_t auxs[2] = { rgid, sgid }; |
44 | size_t ngen, naux; |
45 | |
46 | newgen = _hurd_id.gen.gids; |
47 | ngen = _hurd_id.gen.ngids; |
48 | if (egid != -1) |
49 | { |
50 | if (_hurd_id.gen.ngids == 0) |
51 | { |
52 | /* No effective gids now. The new set will be just UID. */ |
53 | newgen = &egid; |
54 | ngen = 1; |
55 | } |
56 | else |
57 | { |
58 | _hurd_id.gen.gids[0] = egid; |
59 | _hurd_id.valid = 0; |
60 | } |
61 | } |
62 | |
63 | newaux = _hurd_id.aux.gids; |
64 | naux = _hurd_id.aux.ngids; |
65 | if (rgid != -1) |
66 | { |
67 | if (_hurd_id.aux.ngids == 0) |
68 | { |
69 | newaux = &rgid; |
70 | naux = 1; |
71 | } |
72 | else |
73 | { |
74 | _hurd_id.aux.gids[0] = rgid; |
75 | _hurd_id.valid = 0; |
76 | } |
77 | } |
78 | |
79 | if (sgid != -1) |
80 | { |
81 | if (rgid == -1) |
82 | { |
83 | if (_hurd_id.aux.ngids >= 1) |
84 | auxs[0] = _hurd_id.aux.gids[0]; |
85 | else if (_hurd_id.gen.ngids >= 1) |
86 | auxs[0] = _hurd_id.gen.gids[0]; |
87 | else |
88 | /* Not even an effective GID. |
89 | Fall back to the only GID we have. */ |
90 | auxs[0] = sgid; |
91 | } |
92 | if (_hurd_id.aux.ngids <= 1) |
93 | { |
94 | /* No saved gids now. The new set will be just UID. */ |
95 | newaux = auxs; |
96 | naux = 2; |
97 | } |
98 | else |
99 | { |
100 | _hurd_id.aux.gids[1] = sgid; |
101 | _hurd_id.valid = 0; |
102 | } |
103 | } |
104 | |
105 | err = __USEPORT (AUTH, __auth_makeauth |
106 | (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0, |
107 | _hurd_id.gen.uids, _hurd_id.gen.nuids, |
108 | _hurd_id.aux.uids, _hurd_id.aux.nuids, |
109 | newgen, ngen, newaux, naux, |
110 | &newauth)); |
111 | } |
112 | __mutex_unlock (&_hurd_id.lock); |
113 | HURD_CRITICAL_END; |
114 | if (err == EINTR) |
115 | /* Got a signal while inside an RPC of the critical section, retry again */ |
116 | goto retry; |
117 | |
118 | if (err) |
119 | return __hurd_fail (err); |
120 | |
121 | /* Install the new handle and reauthenticate everything. */ |
122 | err = __setauth (newauth); |
123 | __mach_port_deallocate (__mach_task_self (), newauth); |
124 | return err; |
125 | } |
126 | libc_hidden_def (__setresgid) |
127 | weak_alias (__setresgid, setresgid) |
128 | |