109 lines
2.6 KiB
C++
109 lines
2.6 KiB
C++
/*
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* \brief User datagram protocol.
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* \author Stefan Kalkowski
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* \date 2010-08-19
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*/
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/*
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* Copyright (C) 2010-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _UDP_H_
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#define _UDP_H_
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/* Genode */
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#include <base/exception.h>
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#include <base/stdint.h>
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#include <net/port.h>
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#include <util/endian.h>
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#include <net/ethernet.h>
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#include <net/ipv4.h>
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namespace Net { class Udp_packet; }
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/**
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* Data layout of this class conforms to an UDP packet (RFC 768)
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*
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* UDP-header-format:
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*
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* -----------------------------------------------------------------------
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* | source-port | destination-port | length | checksum |
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* | 2 bytes | 2 bytes | 2 bytes | 2 bytes |
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* -----------------------------------------------------------------------
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*/
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class Net::Udp_packet
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{
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private:
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/***********************
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** UDP header fields **
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***********************/
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Genode::uint16_t _src_port;
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Genode::uint16_t _dst_port;
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Genode::uint16_t _length;
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Genode::uint16_t _checksum;
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unsigned _data[0];
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public:
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struct Bad_data_type : Genode::Exception { };
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template <typename T> T const &data(Genode::size_t data_size) const
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{
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if (data_size < sizeof(T)) {
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throw Bad_data_type();
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}
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return *(T const *)(_data);
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}
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template <typename T> T &data(Genode::size_t data_size)
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{
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if (data_size < sizeof(T)) {
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throw Bad_data_type();
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}
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return *(T *)(_data);
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}
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template <typename T, typename SIZE_GUARD>
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T &construct_at_data(SIZE_GUARD &size_guard)
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{
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size_guard.add(sizeof(T));
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return *Genode::construct_at<T>(_data);
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}
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void update_checksum(Ipv4_address ip_src,
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Ipv4_address ip_dst);
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bool checksum_error(Ipv4_address ip_src,
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Ipv4_address ip_dst) const;
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/***************
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** Accessors **
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***************/
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Port src_port() const { return Port(host_to_big_endian(_src_port)); }
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Port dst_port() const { return Port(host_to_big_endian(_dst_port)); }
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Genode::uint16_t length() const { return host_to_big_endian(_length); }
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Genode::uint16_t checksum() const { return host_to_big_endian(_checksum); }
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void length(Genode::uint16_t v) { _length = host_to_big_endian(v); }
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void src_port(Port p) { _src_port = host_to_big_endian(p.value); }
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void dst_port(Port p) { _dst_port = host_to_big_endian(p.value); }
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/*********
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** log **
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*********/
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void print(Genode::Output &output) const;
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} __attribute__((packed));
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#endif /* _UDP_H_ */
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