src/lxc/caps.h

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #ifndef __LXC_CAPS_H
  25 #define __LXC_CAPS_H
  26
  27 #include "config.h"
  28 #include <stdbool.h>
  29
  30
  31 #if HAVE_LIBCAP
  32 #include <sys/capability.h>
  33
  34 extern int lxc_caps_down(void);
  35 extern int lxc_caps_up(void);
  36 extern int lxc_caps_init(void);
  37
  38 extern int lxc_caps_last_cap(void);
  39
  40 extern bool lxc_proc_cap_is_set(cap_value_t cap, cap_flag_t flag);
  41 extern bool lxc_file_cap_is_set(const char *path, cap_value_t cap, cap_flag_t flag);
  42 #else
  43 static inline int lxc_caps_down(void) {
  44         return 0;
  45 }
  46 static inline int lxc_caps_up(void) {
  47         return 0;
  48 }
  49 static inline int lxc_caps_init(void) {
  50         return 0;
  51 }
  52
  53 static inline int lxc_caps_last_cap(void) {
  54         return 0;
  55 }
  56
  57 typedef int cap_value_t;
  58 typedef int cap_flag_t;
  59 static inline bool lxc_proc_cap_is_set(cap_value_t cap, cap_flag_t flag) {
  60         return false;
  61 }
  62
  63 static inline bool lxc_file_cap_is_set(const char *path, cap_value_t cap, cap_flag_t flag) {
  64         return false;
  65 }
  66 #endif
  67
  68 #define lxc_priv(__lxc_function)                        \
  69         ({                                              \
  70                 __label__ out;                          \
  71                 int __ret, __ret2, ___errno = 0;                \
  72                 __ret = lxc_caps_up();                  \
  73                 if (__ret)                              \
  74                         goto out;                       \
  75                 __ret = __lxc_function;                 \
  76                 if (__ret)                              \
  77                         ___errno = errno;               \
  78                 __ret2 = lxc_caps_down();               \
  79         out:    __ret ? errno = ___errno,__ret : __ret2;        \
  80         })
  81
  82 #define lxc_unpriv(__lxc_function)                      \
  83         ({                                              \
  84                 __label__ out;                          \
  85                 int __ret, __ret2, ___errno = 0;                \
  86                 __ret = lxc_caps_down();                \
  87                 if (__ret)                              \
  88                         goto out;                       \
  89                 __ret = __lxc_function;                 \
  90                 if (__ret)                              \
  91                         ___errno = errno;               \
  92                 __ret2 = lxc_caps_up();                 \
  93         out:    __ret ? errno = ___errno,__ret : __ret2;        \
  94         })
  95 #endif