openvpn3/openvpn/common/endian.hpp

//    OpenVPN -- An application to securely tunnel IP networks
//               over a single port, with support for SSL/TLS-based
//               session authentication and key exchange,
//               packet encryption, packet authentication, and
//               packet compression.
//
//    Copyright (C) 2012-2015 OpenVPN Technologies, Inc.
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Affero General Public License Version 3
//    as published by the Free Software Foundation.
//
//    This program 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 Affero General Public License for more details.
//
//    You should have received a copy of the GNU Affero General Public License
//    along with this program in the COPYING file.
//    If not, see <http://www.gnu.org/licenses/>.

// Test for machine endiannes

#ifndef OPENVPN_COMMON_ENDIAN_H
#define OPENVPN_COMMON_ENDIAN_H

#include <boost/detail/endian.hpp>

namespace openvpn {
  namespace Endian {
#   ifdef BOOST_LITTLE_ENDIAN
    inline size_t e16(const size_t v)
    {
      return v;
    }
    inline size_t e16rev(const size_t v)
    {
      return 15-v;
    }
    inline size_t e4(const size_t v)
    {
      return v;
    }
    inline size_t e4rev(const size_t v)
    {
      return 3-v;
    }
    inline size_t e2(const size_t v)
    {
      return v;
    }
    inline size_t e2rev(const size_t v)
    {
      return 1-v;
    }
#   elif BOOST_BIG_ENDIAN
    inline size_t e16rev(const size_t v)
    {
      return v;
    }
    inline size_t e16(const size_t v)
    {
      return 15-v;
    }
    inline size_t e4rev(const size_t v)
    {
      return v;
    }
    inline size_t e4(const size_t v)
    {
      return 3-v;
    }
    inline size_t e2rev(const size_t v)
    {
      return v;
    }
    inline size_t e2(const size_t v)
    {
      return 1-v;
    }
#   else
#   error One of BOOST_LITTLE_ENDIAN or BOOST_BIG_ENDIAN must be defined
#   endif
  }
} // namespace openvpn

#endif // OPENVPN_COMMON_ENDIAN_H