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 BOOL getgroups_user(const char *user, gid_t **ret_groups, int *ngroups)
  41 {
  42         struct passwd *pwd;
  43         int ngrp, max_grp;
  44         gid_t *temp_groups;
  45         gid_t *groups;
  46         int i;
  47
  48         pwd = getpwnam_alloc(user);
  49         if (!pwd) return False;
  50
  51         max_grp = groups_max();
  52         temp_groups = SMB_MALLOC_ARRAY(gid_t, max_grp);
  53         if (! temp_groups) {
  54                 passwd_free(&pwd);
  55                 return False;
  56         }
  57
  58         if (sys_getgrouplist(user, pwd->pw_gid, temp_groups, &max_grp) == -1) {
  59
  60                 gid_t *groups_tmp;
  61
  62                 groups_tmp = SMB_REALLOC_ARRAY(temp_groups, gid_t, max_grp);
  63
  64                 if (!groups_tmp) {
  65                         SAFE_FREE(temp_groups);
  66                         return False;
  67                 }
  68                 temp_groups = groups_tmp;
  69
  70                 if (sys_getgrouplist(user, pwd->pw_gid, temp_groups, &max_grp) == -1) {
  71                         DEBUG(0, ("get_user_groups: failed to get the unix group list\n"));
  72                         passwd_free(&pwd);
  73                         SAFE_FREE(temp_groups);
  74                         return False;
  75                 }
  76         }
  77
  78         ngrp = 0;
  79         groups = NULL;
  80
  81         /* Add in primary group first */
  82         add_gid_to_array_unique(pwd->pw_gid, &groups, &ngrp);
  83
  84         passwd_free(&pwd);
  85
  86         for (i=0; i<max_grp; i++)
  87                 add_gid_to_array_unique(temp_groups[i], &groups, &ngrp);
  88
  89         *ngroups = ngrp;
  90         *ret_groups = groups;
  91         SAFE_FREE(temp_groups);
  92         return True;
  93 }
  94