/* provide consistent interface to getgroups for systems that don't allow N==0
- Copyright (C) 1996 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1996, 1999, 2003, 2006-2014 Free Software Foundation, Inc.
+
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* written by Jim Meyering */
#include <config.h>
-#include <stdio.h>
-#include <sys/types.h>
-char *xmalloc ();
+#include <unistd.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#if !HAVE_GETGROUPS
+
+/* Provide a stub that fails with ENOSYS, since there is no group
+ information available on mingw. */
+int
+getgroups (int n _GL_UNUSED, GETGROUPS_T *groups _GL_UNUSED)
+{
+ errno = ENOSYS;
+ return -1;
+}
+
+#else /* HAVE_GETGROUPS */
-/* On Ultrix 4.3, getgroups (0, 0) always fails.
- This function handles that special case and lets the system-
- provided function handle all others. */
+# undef getgroups
+# ifndef GETGROUPS_ZERO_BUG
+# define GETGROUPS_ZERO_BUG 0
+# endif
+
+/* On OS X 10.6 and later, use the usual getgroups, not the one
+ supplied when _DARWIN_C_SOURCE is defined. _DARWIN_C_SOURCE is
+ normally defined, since it means "conform to POSIX, but add
+ non-POSIX extensions even if that violates the POSIX namespace
+ rules", which is what we normally want. But with getgroups there
+ is an inconsistency, and _DARWIN_C_SOURCE means "change getgroups()
+ so that it no longer works right". The BUGS section of compat(5)
+ says that the behavior is dubious if you compile different sections
+ of a program with different _DARWIN_C_SOURCE settings, so fix only
+ the offending symbol. */
+# ifdef __APPLE__
+int posix_getgroups (int, gid_t []) __asm ("_getgroups");
+# define getgroups posix_getgroups
+# endif
+
+/* On at least Ultrix 4.3 and NextStep 3.2, getgroups (0, NULL) always
+ fails. On other systems, it returns the number of supplemental
+ groups for the process. This function handles that special case
+ and lets the system-provided function handle all others. However,
+ it can fail with ENOMEM if memory is tight. It is unspecified
+ whether the effective group id is included in the list. */
int
-getgroups (n, group)
- size_t n;
- GETGROUPS_T *group;
+rpl_getgroups (int n, gid_t *group)
{
- int ng;
+ int n_groups;
GETGROUPS_T *gbuf;
+ int saved_errno;
+
+ if (n < 0)
+ {
+ errno = EINVAL;
+ return -1;
+ }
-#undef getgroups
+ if (n != 0 || !GETGROUPS_ZERO_BUG)
+ {
+ int result;
+ if (sizeof *group == sizeof *gbuf)
+ return getgroups (n, (GETGROUPS_T *) group);
- if (n != 0)
- return getgroups (n, group);
+ if (SIZE_MAX / sizeof *gbuf <= n)
+ {
+ errno = ENOMEM;
+ return -1;
+ }
+ gbuf = malloc (n * sizeof *gbuf);
+ if (!gbuf)
+ return -1;
+ result = getgroups (n, gbuf);
+ if (0 <= result)
+ {
+ n = result;
+ while (n--)
+ group[n] = gbuf[n];
+ }
+ saved_errno = errno;
+ free (gbuf);
+ errno = saved_errno;
+ return result;
+ }
n = 20;
- gbuf = NULL;
while (1)
{
- gbuf = (GETGROUPS_T *) xrealloc (gbuf, n * sizeof (GETGROUPS_T));
- ng = getgroups (n, gbuf);
- if (ng < n)
- break;
- n += 10;
+ /* No need to worry about address arithmetic overflow here,
+ since the ancient systems that we're running on have low
+ limits on the number of secondary groups. */
+ gbuf = malloc (n * sizeof *gbuf);
+ if (!gbuf)
+ return -1;
+ n_groups = getgroups (n, gbuf);
+ if (n_groups == -1 ? errno != EINVAL : n_groups < n)
+ break;
+ free (gbuf);
+ n *= 2;
}
+ saved_errno = errno;
free (gbuf);
+ errno = saved_errno;
- return ng;
+ return n_groups;
}
+
+#endif /* HAVE_GETGROUPS */