lib/libc/gen/initgroups.c

   1 /*      $NetBSD: initgroups.c,v 1.22 2012/06/25 22:32:43 abs Exp $      */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)initgroups.c        8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: initgroups.c,v 1.22 2012/06/25 22:32:43 abs Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42 #include <sys/param.h>
  43
  44 #include <assert.h>
  45 #include <stdio.h>
  46 #include <unistd.h>
  47 #include <stdlib.h>
  48 #include <errno.h>
  49
  50 #ifdef __weak_alias
  51 __weak_alias(initgroups,_initgroups)
  52 #endif
  53
  54 int
  55 initgroups(const char *uname, gid_t agroup)
  56 {
  57         gid_t groups_list[NGROUPS];
  58         int ngroups;
  59         gid_t *groups = groups_list;
  60         int rval;
  61
  62         _DIAGASSERT(uname != NULL);
  63
  64         ngroups = NGROUPS;
  65         if (getgrouplist(uname, agroup, groups, &ngroups) == -1) {
  66                 int maxgroups = ngroups;
  67                 groups = calloc((size_t)maxgroups, sizeof *groups);
  68                 if (groups == NULL)
  69                         return -1;
  70                 if (getgrouplist(uname, agroup, groups, &ngroups) == -1)
  71                         ngroups = maxgroups;
  72         }
  73         rval = setgroups(ngroups, groups);
  74         if (rval == -1 && errno == EINVAL) {
  75                 int ng = (int)sysconf(_SC_NGROUPS_MAX);
  76                 if (ng > 0 && ng < ngroups)
  77                         rval = setgroups(ng, groups);
  78         }
  79         if (groups != groups_list)
  80                 free(groups);
  81         return rval;
  82 }