src/lxc/caps.h

	caps.h revision 768770715092c699eda199255f2f6f8a6f6cab49
/*
 * lxc: linux Container library
 *
 * (C) Copyright IBM Corp. 2007, 2008
 *
 * Authors:
 * Daniel Lezcano <daniel.lezcano at free.fr>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "config.h"
#include <stdbool.h>

#ifndef __LXC_CAPS_H
#define __LXC_CAPS_H

#if HAVE_LIBCAP
#include <sys/capability.h>

extern int lxc_caps_down(void);
extern int lxc_caps_up(void);
extern int lxc_caps_init(void);

extern int lxc_caps_last_cap(void);

extern bool lxc_cap_is_set(cap_value_t cap, cap_flag_t flag);
#else
static inline int lxc_caps_down(void) {
    return 0;
}
static inline int lxc_caps_up(void) {
    return 0;
}
static inline int lxc_caps_init(void) {
    return 0;
}

static inline int lxc_caps_last_cap(void) {
    return 0;
}

typedef int cap_value_t;
typedef int cap_flag_t;
static inline bool lxc_cap_is_set(cap_value_t cap, cap_flag_t flag) {
    return true;
}
#endif

#define lxc_priv(__lxc_function)            \
    ({                      \
        __label__ out;              \
        int __ret, __ret2, ___errno = 0;        \
        __ret = lxc_caps_up();          \
        if (__ret)              \
            goto out;           \
        __ret = __lxc_function;         \
        if (__ret)              \
            ___errno = errno;       \
        __ret2 = lxc_caps_down();       \
    out:    __ret ? errno = ___errno,__ret : __ret2;    \
    })

#define lxc_unpriv(__lxc_function)          \
    ({                      \
        __label__ out;              \
        int __ret, __ret2, ___errno = 0;        \
        __ret = lxc_caps_down();        \
        if (__ret)              \
            goto out;           \
        __ret = __lxc_function;         \
        if (__ret)              \
            ___errno = errno;       \
        __ret2 = lxc_caps_up();         \
    out:    __ret ? errno = ___errno,__ret : __ret2;    \
    })
#endif