source/lib/util_smbd.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions, used in smbd only
   4    Copyright (C) Andrew Tridgell 2002
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 /*
  24    This function requires sys_getgrouplist - which is only
  25    available in smbd due to it's use of become_root() in a
  26    legacy systems hack.
  27 */
  28
  29 /*
  30   return a full list of groups for a user
  31
  32   returns the number of groups the user is a member of. The return will include the
  33   users primary group.
  34
  35   remember to free the resulting gid_t array
  36
  37   NOTE! uses become_root() to gain correct priviages on systems
  38   that lack a native getgroups() call (uses initgroups and getgroups)
  39 */
  40 int getgroups_user(const char *user, gid_t **groups)
  41 {
  42         struct passwd *pwd;
  43         int ngrp, max_grp;
  44
  45         pwd = getpwnam_alloc(user);
  46         if (!pwd) return -1;
  47
  48         max_grp = groups_max();
  49         (*groups) = (gid_t *)malloc(sizeof(gid_t) * max_grp);
  50         if (! *groups) {
  51                 passwd_free(&pwd);
  52                 errno = ENOMEM;
  53                 return -1;
  54         }
  55
  56         ngrp = sys_getgrouplist(user, pwd->pw_gid, *groups, &max_grp);
  57         if (ngrp <= 0) {
  58                 passwd_free(&pwd);
  59                 free(*groups);
  60                 return ngrp;
  61         }
  62
  63         passwd_free(&pwd);
  64         return ngrp;
  65 }