src/shared/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 2011,2013 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 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   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser 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 #include "util.h"
  30 #include "strv.h"
  31
  32 int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *entry) {
  33         acl_entry_t i;
  34         int found;
  35
  36         assert(acl);
  37         assert(entry);
  38
  39         for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
  40              found > 0;
  41              found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
  42
  43                 acl_tag_t tag;
  44                 uid_t *u;
  45                 bool b;
  46
  47                 if (acl_get_tag_type(i, &tag) < 0)
  48                         return -errno;
  49
  50                 if (tag != ACL_USER)
  51                         continue;
  52
  53                 u = acl_get_qualifier(i);
  54                 if (!u)
  55                         return -errno;
  56
  57                 b = *u == uid;
  58                 acl_free(u);
  59
  60                 if (b) {
  61                         *entry = i;
  62                         return 1;
  63                 }
  64         }
  65
  66         if (found < 0)
  67                 return -errno;
  68
  69         return 0;
  70 }
  71
  72 int calc_acl_mask_if_needed(acl_t *acl_p) {
  73         acl_entry_t i;
  74         int found;
  75
  76         assert(acl_p);
  77
  78         for (found = acl_get_entry(*acl_p, ACL_FIRST_ENTRY, &i);
  79              found > 0;
  80              found = acl_get_entry(*acl_p, ACL_NEXT_ENTRY, &i)) {
  81
  82                 acl_tag_t tag;
  83
  84                 if (acl_get_tag_type(i, &tag) < 0)
  85                         return -errno;
  86
  87                 if (tag == ACL_MASK)
  88                         return 0;
  89         }
  90
  91         if (found < 0)
  92                 return -errno;
  93
  94         if (acl_calc_mask(acl_p) < 0)
  95                 return -errno;
  96
  97         return 0;
  98 }
  99
 100 int search_acl_groups(char*** dst, const char* path, bool* belong) {
 101         acl_t acl;
 102
 103         assert(path);
 104         assert(belong);
 105
 106         acl = acl_get_file(path, ACL_TYPE_DEFAULT);
 107         if (acl) {
 108                 acl_entry_t entry;
 109                 int r;
 110
 111                 r = acl_get_entry(acl, ACL_FIRST_ENTRY, &entry);
 112                 while (r > 0) {
 113                         acl_tag_t tag;
 114                         gid_t *gid;
 115                         char *name;
 116
 117                         r = acl_get_tag_type(entry, &tag);
 118                         if (r < 0)
 119                                 break;
 120
 121                         if (tag != ACL_GROUP)
 122                                 goto next;
 123
 124                         gid = acl_get_qualifier(entry);
 125                         if (!gid)
 126                                 break;
 127
 128                         if (in_gid(*gid) > 0) {
 129                                 *belong = true;
 130                                 break;
 131                         }
 132
 133                         name = gid_to_name(*gid);
 134                         if (!name) {
 135                                 acl_free(acl);
 136                                 return log_oom();
 137                         }
 138
 139                         r = strv_push(dst, name);
 140                         if (r < 0) {
 141                                 free(name);
 142                                 acl_free(acl);
 143                                 return log_oom();
 144                         }
 145
 146                 next:
 147                         r = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry);
 148                 }
 149
 150                 acl_free(acl);
 151         }
 152
 153         return 0;
 154 }