1 /* Tests of getgroups.
2    Copyright (C) 2009-2021 Free Software Foundation, Inc.
3 
4    This program is free software: you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 3 of the License, or
7    (at your option) any later version.
8 
9    This program 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
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
16 
17 /* Written by Eric Blake <ebb9@byu.net>, 2009.  */
18 
19 #include <config.h>
20 
21 #include <unistd.h>
22 
23 #include "signature.h"
24 SIGNATURE_CHECK (getgroups, int, (int, gid_t[]));
25 
26 #include <errno.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <stdint.h>
30 
31 #include "macros.h"
32 
33 /* Tell GCC not to warn about the specific edge cases tested here.
34    GCC >= 10 with glibc >= 2.32 would otherwise trigger warnings, even without
35    any -W options, because getgroups() is declared with
36      __attribute__ ((__access__ (__write_only__, 2, 1)))
37  */
38 #if __GNUC__ >= 7
39 # pragma GCC diagnostic ignored "-Wstringop-overflow"
40 #endif
41 
42 int
main(int argc,_GL_UNUSED char ** argv)43 main (int argc, _GL_UNUSED char **argv)
44 {
45   int result;
46   gid_t *groups;
47 
48   errno = 0;
49   result = getgroups (0, NULL);
50   if (result == -1 && errno == ENOSYS)
51     {
52       fputs ("skipping test: no support for groups\n", stderr);
53       return 77;
54     }
55   ASSERT (0 <= result);
56   ASSERT (result + 1 < SIZE_MAX / sizeof *groups);
57   groups = malloc ((result + 1) * sizeof *groups);
58   ASSERT (groups);
59   groups[result] = -1;
60   /* Check for EINVAL handling.  Not all processes have supplemental
61      groups, and getgroups does not have to return the effective gid,
62      so a result of 0 is reasonable.  Also, we can't test for EINVAL
63      if result is 1, because of how getgroups treats 0.  */
64   if (1 < result)
65     {
66       errno = 0;
67       ASSERT (getgroups (result - 1, groups) == -1);
68       ASSERT (errno == EINVAL);
69     }
70   ASSERT (getgroups (result, groups) == result);
71   ASSERT (getgroups (result + 1, groups) == result);
72   ASSERT (groups[result] == -1);
73   errno = 0;
74   ASSERT (getgroups (-1, NULL) == -1);
75   ASSERT (errno == EINVAL);
76 
77   /* The automated unit test, with no arguments, ends here.  However,
78      for debugging purposes, you can pass a command-line argument to
79      list the returned groups.  */
80   if (1 < argc)
81     {
82       int i;
83       for (i = 0; i < result; i++)
84         printf ("%d\n", (int) groups[i]);
85     }
86   free (groups);
87   return 0;
88 }
89