171 lines
4.0 KiB
C++
171 lines
4.0 KiB
C++
/*
|
|
* \brief Ethernet protocol
|
|
* \author Stefan Kalkowski
|
|
* \date 2010-08-19
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2010-2017 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU Affero General Public License version 3.
|
|
*/
|
|
|
|
#ifndef _NET__ETHERNET_H_
|
|
#define _NET__ETHERNET_H_
|
|
|
|
/* Genode includes */
|
|
#include <base/exception.h>
|
|
#include <util/string.h>
|
|
#include <util/construct_at.h>
|
|
#include <util/endian.h>
|
|
#include <net/mac_address.h>
|
|
#include <net/size_guard.h>
|
|
|
|
namespace Net
|
|
{
|
|
class Ethernet_frame;
|
|
|
|
template <Genode::size_t DATA_SIZE>
|
|
class Ethernet_frame_sized;
|
|
}
|
|
|
|
|
|
/**
|
|
* Data layout of this class conforms to the Ethernet II frame
|
|
* (IEEE 802.3).
|
|
*
|
|
* Ethernet-frame-header-format:
|
|
*
|
|
* ----------------------------------------------------------
|
|
* | destination mac address | source mac address | ethertype |
|
|
* | 6 bytes | 6 bytes | 2 bytes |
|
|
* ----------------------------------------------------------
|
|
*/
|
|
class Net::Ethernet_frame
|
|
{
|
|
public:
|
|
|
|
enum Size {
|
|
ADDR_LEN = 6, /* MAC address length in bytes */
|
|
};
|
|
|
|
static Mac_address broadcast() { return Mac_address((Genode::uint8_t)0xff); }
|
|
|
|
private:
|
|
|
|
Genode::uint8_t _dst[ADDR_LEN]; /* destination mac address */
|
|
Genode::uint8_t _src[ADDR_LEN]; /* source mac address */
|
|
Genode::uint16_t _type; /* encapsulated protocol */
|
|
unsigned _data[0]; /* encapsulated data */
|
|
|
|
public:
|
|
|
|
enum { MIN_SIZE = 64 };
|
|
|
|
/**
|
|
* Id representing encapsulated protocol.
|
|
*/
|
|
enum class Type : Genode::uint16_t {
|
|
IPV4 = 0x0800,
|
|
ARP = 0x0806,
|
|
};
|
|
|
|
template <typename T>
|
|
T const &data(Size_guard &size_guard) const
|
|
{
|
|
size_guard.consume_head(sizeof(T));
|
|
T const &obj = *(T *)(_data);
|
|
|
|
/* Ethernet may have a tail whose size must be considered */
|
|
Genode::size_t const unconsumed = size_guard.unconsumed();
|
|
size_guard.consume_tail(unconsumed + sizeof(T) -
|
|
obj.size(unconsumed));
|
|
return obj;
|
|
}
|
|
|
|
template <typename T>
|
|
T &data(Size_guard &size_guard)
|
|
{
|
|
size_guard.consume_head(sizeof(T));
|
|
T &obj = *(T *)(_data);
|
|
|
|
/* Ethernet may have a tail whose size must be considered */
|
|
Genode::size_t const max_obj_sz = size_guard.unconsumed() + sizeof(T);
|
|
size_guard.consume_tail(max_obj_sz - obj.size(max_obj_sz));
|
|
return obj;
|
|
}
|
|
|
|
template <typename T>
|
|
T &construct_at_data(Size_guard &size_guard)
|
|
{
|
|
size_guard.consume_head(sizeof(T));
|
|
return *Genode::construct_at<T>(_data);
|
|
}
|
|
|
|
static Ethernet_frame &construct_at(void *base,
|
|
Size_guard &size_guard)
|
|
{
|
|
size_guard.consume_head(sizeof(Ethernet_frame));
|
|
return *Genode::construct_at<Ethernet_frame>(base);
|
|
}
|
|
|
|
static Ethernet_frame &cast_from(void *base,
|
|
Size_guard &size_guard)
|
|
{
|
|
size_guard.consume_head(sizeof(Ethernet_frame));
|
|
return *(Ethernet_frame *)base;
|
|
}
|
|
|
|
|
|
/***************
|
|
** Accessors **
|
|
***************/
|
|
|
|
Mac_address dst() const { return Mac_address((void *)_dst); }
|
|
Mac_address src() const { return Mac_address((void *)_src); }
|
|
Type type() const { return (Type)host_to_big_endian(_type); }
|
|
|
|
void dst(Mac_address v) { v.copy(&_dst); }
|
|
void src(Mac_address v) { v.copy(&_src); }
|
|
void type(Type type) { _type = host_to_big_endian((Genode::uint16_t)type); }
|
|
|
|
|
|
/*********
|
|
** log **
|
|
*********/
|
|
|
|
void print(Genode::Output &output) const;
|
|
|
|
} __attribute__((packed));
|
|
|
|
|
|
template <Genode::size_t DATA_SIZE>
|
|
class Net::Ethernet_frame_sized : public Ethernet_frame
|
|
{
|
|
private:
|
|
|
|
enum {
|
|
HS = sizeof(Ethernet_frame),
|
|
DS = DATA_SIZE + HS >= MIN_SIZE ? DATA_SIZE : MIN_SIZE - HS,
|
|
};
|
|
|
|
Genode::uint8_t _data[DS];
|
|
Genode::uint32_t _checksum;
|
|
|
|
public:
|
|
|
|
Ethernet_frame_sized(Mac_address dst_in, Mac_address src_in,
|
|
Type type_in)
|
|
:
|
|
Ethernet_frame()
|
|
{
|
|
dst(dst_in);
|
|
src(src_in);
|
|
type(type_in);
|
|
}
|
|
|
|
} __attribute__((packed));
|
|
|
|
#endif /* _NET__ETHERNET_H_ */
|