mbspcasecmp: Fix function specification.

[gnulib.git] / lib / group-member.c

diff --git a/lib/group-member.c b/lib/group-member.c
index 8823506..8aa3d8c 100644 (file)
--- a/lib/group-member.c
+++ b/lib/group-member.c
@@ -1,10 +1,12 @@
 /* group-member.c -- determine whether group id is in calling user's group list
-   Copyright (C) 1994, 1997, 1998, 2003 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1994, 1997-1998, 2003, 2005-2006, 2009-2010 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
@@ -12,112 +14,91 @@
    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/>.  */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
 #include "group-member.h"
 
+#include <stdbool.h>
 #include <stdio.h>
 #include <sys/types.h>
 #include <stdlib.h>
 
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+#include <unistd.h>
 
 #include "xalloc.h"
 
 struct group_info
   {
     int n_groups;
-    GETGROUPS_T *group;
+    gid_t *group;
   };
 
-#if HAVE_GETGROUPS
-
 static void
-free_group_info (struct group_info *g)
+free_group_info (struct group_info const *g)
 {
   free (g->group);
-  free (g);
 }
 
-static struct group_info *
-get_group_info (void)
+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 = 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 = 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_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
@@ -131,7 +112,7 @@ main (int argc, char **argv)
 
   program_name = argv[0];
 
-  for (i=1; i<argc; i++)
+  for (i = 1; i < argc; i++)
     {
       gid_t gid;