src/acl-util.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <sys/acl.h>
  24 #include <acl/libacl.h>
  25 #include <errno.h>
  26 #include <stdbool.h>
  27
  28 #include "acl-util.h"
  29
  30 int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *entry) {
  31         acl_entry_t i;
  32         int found;
  33
  34         assert(acl);
  35         assert(entry);
  36
  37         for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
  38              found > 0;
  39              found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
  40
  41                 acl_tag_t tag;
  42                 uid_t *u;
  43                 bool b;
  44
  45                 if (acl_get_tag_type(i, &tag) < 0)
  46                         return -errno;
  47
  48                 if (tag != ACL_USER)
  49                         continue;
  50
  51                 u = acl_get_qualifier(i);
  52                 if (!u)
  53                         return -errno;
  54
  55                 b = *u == uid;
  56                 acl_free(u);
  57
  58                 if (b) {
  59                         *entry = i;
  60                         return 1;
  61                 }
  62         }
  63
  64         if (found < 0)
  65                 return -errno;
  66
  67         return 0;
  68 }