genode/repos/os/include/net/udp.h
Martin Stein bd501404db net: add methods required for WireGuard port
* Adds methods for copying raw data to the data field of Ethernet frames and
  UDP packets. This is used in the port to wrap the higher-layer packet data
  prepared by the contrib code with the additionally required headers before
  sending it at a network session.
* Adds a method to cast raw data to an IPv4 packet. This is required in the
  port in order to check values in stand-alone IP packets produced by the
  contrib code before sending them at a network session.
* Adds methods for setting UDP ports given big endian port values without
  having to convert to little endian in the app and then back to big endian in
  the net lib.

Ref #4397
2022-05-25 12:23:02 +02:00

116 lines
3.0 KiB
C++

/*
* \brief User datagram 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 _UDP_H_
#define _UDP_H_
/* Genode */
#include <base/exception.h>
#include <base/stdint.h>
#include <net/port.h>
#include <util/endian.h>
#include <net/ethernet.h>
#include <net/ipv4.h>
namespace Net { class Udp_packet; }
/**
* Data layout of this class conforms to an UDP packet (RFC 768)
*
* UDP-header-format:
*
* -----------------------------------------------------------------------
* | source-port | destination-port | length | checksum |
* | 2 bytes | 2 bytes | 2 bytes | 2 bytes |
* -----------------------------------------------------------------------
*/
class Net::Udp_packet
{
private:
/***********************
** UDP header fields **
***********************/
Genode::uint16_t _src_port;
Genode::uint16_t _dst_port;
Genode::uint16_t _length;
Genode::uint16_t _checksum;
unsigned _data[0];
public:
template <typename T>
T const &data(Size_guard &size_guard) const
{
size_guard.consume_head(sizeof(T));
return *(T const *)(_data);
}
template <typename T>
T &data(Size_guard &size_guard)
{
size_guard.consume_head(sizeof(T));
return *(T *)(_data);
}
template <typename T, typename SIZE_GUARD>
T &construct_at_data(SIZE_GUARD &size_guard)
{
size_guard.consume_head(sizeof(T));
return *Genode::construct_at<T>(_data);
}
template <typename SIZE_GUARD>
void memcpy_to_data(void const *src_base,
Genode::size_t src_size,
SIZE_GUARD &size_guard)
{
size_guard.consume_head(src_size);
Genode::memcpy(_data, src_base, src_size);
}
void update_checksum(Ipv4_address ip_src,
Ipv4_address ip_dst);
bool checksum_error(Ipv4_address ip_src,
Ipv4_address ip_dst) const;
/***************
** Accessors **
***************/
Port src_port() const { return Port(host_to_big_endian(_src_port)); }
Port dst_port() const { return Port(host_to_big_endian(_dst_port)); }
Genode::uint16_t length() const { return host_to_big_endian(_length); }
Genode::uint16_t checksum() const { return host_to_big_endian(_checksum); }
void length(Genode::uint16_t v) { _length = host_to_big_endian(v); }
void src_port(Port p) { _src_port = host_to_big_endian(p.value); }
void dst_port(Port p) { _dst_port = host_to_big_endian(p.value); }
void src_port_big_endian(Genode::uint16_t v) { _src_port = v; }
void dst_port_big_endian(Genode::uint16_t v) { _dst_port = v; }
/*********
** log **
*********/
void print(Genode::Output &output) const;
} __attribute__((packed));
#endif /* _UDP_H_ */