81 lines
2.1 KiB
C++
81 lines
2.1 KiB
C++
|
#ifndef OSI_LAYER_HPP_C4VTEZJP
|
||
|
|
#define OSI_LAYER_HPP_C4VTEZJP
|
||
|
|
|
||
|
|
#include <boost/range/iterator_range.hpp>
|
||
|
|
#include <array>
|
||
|
|
#include <cstdint>
|
||
|
|
|
||
|
|
namespace vanetza
|
||
|
|
{
|
||
|
|
|
||
|
|
enum class OsiLayer : uint8_t
|
||
|
|
{
|
||
|
|
Physical = 1,
|
||
|
|
Link = 2,
|
||
|
|
Network = 3,
|
||
|
|
Transport = 4,
|
||
|
|
Session = 5,
|
||
|
|
Presentation = 6,
|
||
|
|
Application = 7
|
||
|
|
};
|
||
|
|
|
||
|
|
constexpr OsiLayer min_osi_layer() { return OsiLayer::Physical; }
|
||
|
|
constexpr OsiLayer max_osi_layer() { return OsiLayer::Application; }
|
||
|
|
|
||
|
|
constexpr std::array<OsiLayer, 7> osi_layers {{
|
||
|
|
OsiLayer::Physical,
|
||
|
|
OsiLayer::Link,
|
||
|
|
OsiLayer::Network,
|
||
|
|
OsiLayer::Transport,
|
||
|
|
OsiLayer::Session,
|
||
|
|
OsiLayer::Presentation,
|
||
|
|
OsiLayer::Application
|
||
|
|
}};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Calculate distance between layers
|
||
|
|
* \param from start counting at this layer
|
||
|
|
* \param to stop counting here
|
||
|
|
* \return 0 if equal layers, positive if "to" is a higher layer, negative if "to" is below "from"
|
||
|
|
*/
|
||
|
|
constexpr int distance(OsiLayer from, OsiLayer to)
|
||
|
|
{
|
||
|
|
return static_cast<int>(to) - static_cast<int>(from);
|
||
|
|
}
|
||
|
|
|
||
|
|
constexpr std::size_t num_osi_layers(OsiLayer from, OsiLayer to)
|
||
|
|
{
|
||
|
|
return (from <= to ? distance(from, to) + 1 : 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
template<OsiLayer FROM, OsiLayer TO>
|
||
|
|
std::array<OsiLayer, num_osi_layers(FROM, TO)> osi_layer_range()
|
||
|
|
{
|
||
|
|
static_assert(FROM <= TO, "FROM layer is above TO layer");
|
||
|
|
typedef typename std::underlying_type<OsiLayer>::type num_type;
|
||
|
|
|
||
|
|
num_type num = static_cast<num_type>(FROM);
|
||
|
|
std::array<OsiLayer, num_osi_layers(FROM, TO)> layers;
|
||
|
|
for (auto& layer : layers) {
|
||
|
|
layer = static_cast<OsiLayer>(num++);
|
||
|
|
}
|
||
|
|
return layers;
|
||
|
|
}
|
||
|
|
|
||
|
|
inline boost::iterator_range<decltype(osi_layers)::const_iterator>
|
||
|
|
osi_layer_range(OsiLayer from, OsiLayer to)
|
||
|
|
{
|
||
|
|
if (from <= to) {
|
||
|
|
auto begin = osi_layers.cbegin() + distance(min_osi_layer(), from);
|
||
|
|
auto end = osi_layers.cend() - distance(to, max_osi_layer());
|
||
|
|
return boost::make_iterator_range(begin, end);
|
||
|
|
} else {
|
||
|
|
return boost::make_iterator_range(osi_layers.cend(), osi_layers.cend());
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace vanetza
|
||
|
|
|
||
|
|
#endif /* OSI_LAYER_HPP_C4VTEZJP */
|
||
|
|
|