/* group-member.c -- determine whether group id is in calling user's group list
- Copyright (C) 1994 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1994, 1997-1998, 2003, 2005-2006, 2009-2011 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/>. */
-#ifdef HAVE_CONFIG_H
#include <config.h>
-#endif
+/* Specification. */
+#include <unistd.h>
+
+#include <stdbool.h>
#include <stdio.h>
#include <sys/types.h>
-
-#ifdef STDC_HEADERS
#include <stdlib.h>
-#endif
-
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
-#include "group-member.h"
-char *xmalloc ();
-char *xrealloc ();
+#include "xalloc.h"
struct group_info
{
int n_groups;
- GETGROUPS_T *group;
+ gid_t *group;
};
-#ifdef HAVE_GETGROUPS
-
static void
-free_group_info (g)
- struct group_info *g;
+free_group_info (struct group_info const *g)
{
free (g->group);
- free (g);
}
-static struct group_info *
-get_group_info ()
+static bool
+get_group_info (struct group_info *gi)
{
int n_groups;
- int n_group_slots;
- struct group_info *gi;
- GETGROUPS_T *group;
-
- /* getgroups () returns the number of elements that it was able to
- place into the array. We simply continue to call getgroups ()
- until the number of elements placed into the array is smaller than
- the physical size of the array. */
-
- group = NULL;
- n_groups = 0;
- n_group_slots = 0;
- while (n_groups == n_group_slots)
- {
- n_group_slots += 64;
- group = (GETGROUPS_T *) xrealloc (group,
- n_group_slots * sizeof (GETGROUPS_T));
- n_groups = getgroups (n_group_slots, group);
- }
+ int n_group_slots = getgroups (0, NULL);
+ gid_t *group;
+
+ if (n_group_slots < 0)
+ return false;
+
+ /* Avoid xnmalloc, as it goes awry when SIZE_MAX < n_group_slots. */
+ if (xalloc_oversized (n_group_slots, sizeof *group))
+ xalloc_die ();
+ group = xmalloc (n_group_slots * sizeof *group);
+ n_groups = getgroups (n_group_slots, group);
/* In case of error, the user loses. */
if (n_groups < 0)
{
free (group);
- return NULL;
+ return false;
}
- gi = (struct group_info *) xmalloc (sizeof (*gi));
gi->n_groups = n_groups;
gi->group = group;
- return gi;
+ return true;
}
-#endif /* not HAVE_GETGROUPS */
-
/* Return non-zero if GID is one that we have in our groups list.
- If there is no getgroups function, return non-zero if GID matches
- either of the current or effective group IDs. */
+ Note that the groups list is not guaranteed to contain the current
+ or effective group ID, so they should generally be checked
+ separately. */
int
-group_member (gid)
- gid_t gid;
+group_member (gid_t gid)
{
-#ifndef HAVE_GETGROUPS
- return ((gid == getgid ()) || (gid == getegid ()));
-#else
int i;
int found;
- struct group_info *gi;
+ struct group_info gi;
- gi = get_group_info ();
- if (gi == NULL)
+ if (! get_group_info (&gi))
return 0;
/* Search through the list looking for GID. */
found = 0;
- for (i = 0; i < gi->n_groups; i++)
+ for (i = 0; i < gi.n_groups; i++)
{
- if (gid == gi->group[i])
- {
- found = 1;
- break;
- }
+ if (gid == gi.group[i])
+ {
+ found = 1;
+ break;
+ }
}
-
- free_group_info (gi);
+
+ free_group_info (&gi);
return found;
-#endif /* HAVE_GETGROUPS */
}
#ifdef TEST
char *program_name;
int
-main (int argc, char** argv)
+main (int argc, char **argv)
{
int i;
program_name = argv[0];
- for (i=1; i<argc; i++)
+ for (i = 1; i < argc; i++)
{
gid_t gid;