sys/getgroups.c

   1 /*
   2  * Copyright (c) 2008 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #define _DARWIN_C_SOURCE
  24
  25 #include <errno.h>
  26 #include <pwd.h>
  27 #include <stdint.h>
  28 #include <unistd.h>
  29
  30 int32_t getgroupcount(const char *name, gid_t basegid);
  31
  32 /*
  33  * getgroups extension; not limited by NGROUPS_MAX
  34  */
  35 int
  36 getgroups(int gidsetsize, gid_t grouplist[])
  37 {
  38     struct passwd *pw;
  39     int n;
  40
  41     if ((pw = getpwuid(getuid())) == NULL) {
  42         errno = EINVAL;
  43         return -1;
  44     }
  45     if (gidsetsize == 0) {
  46         if ((n = getgroupcount(pw->pw_name, pw->pw_gid)) == 0) {
  47             errno = EINVAL;
  48             return -1;
  49         }
  50         return n;
  51     }
  52     n = gidsetsize;
  53     if (getgrouplist(pw->pw_name, pw->pw_gid, (int *)grouplist, &n) < 0) {
  54         errno = EINVAL;
  55         return -1;
  56     }
  57     return n;
  58 }