genode/repos/os/include/net/icmp.h
Martin Stein 980f3e9c5c net: use Size_guard for packet-data accessors
Instead of handing over the maximum available size to the packet data
accessors, hand over a size guard that keeps track of the packets
boundaries.

This commit also moves the size-guard utilitiy header of Ping and NIC
Router to the include/net directory making it a part of the net library.
It applies the new approach to all net-lib users in the basic repositories.

Ping looses its configurability regarding the ICMP data size as this would
require an additional method in the size guard which would be used only by
Ping.

The size guard was also re-worked to fit the fact that a packet can
bring a tail as well as a header (Ethernet).

Issue #2788
2018-05-30 13:36:11 +02:00

113 lines
2.8 KiB
C++

/*
* \brief Internet Control Message Protocol
* \author Martin Stein
* \date 2018-03-23
*/
/*
* Copyright (C) 2018 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__ICMP_H_
#define _NET__ICMP_H_
/* Genode includes */
#include <util/endian.h>
#include <base/exception.h>
namespace Genode { class Output; }
namespace Net { class Icmp_packet; }
class Net::Icmp_packet
{
private:
Genode::uint8_t _type;
Genode::uint8_t _code;
Genode::uint16_t _checksum;
union {
Genode::uint32_t _rest_of_header_u32[1];
Genode::uint16_t _rest_of_header_u16[2];
Genode::uint8_t _rest_of_header_u8[4];
} __attribute__((packed));
Genode::uint8_t _data[0];
public:
enum class Type
{
ECHO_REPLY = 0,
DST_UNREACHABLE = 3,
ECHO_REQUEST = 8,
};
enum class Code
{
DST_NET_UNREACHABLE = 0,
ECHO_REQUEST = 0,
ECHO_REPLY = 0,
};
void update_checksum(Genode::size_t data_sz);
bool checksum_error(Genode::size_t data_sz) const;
/***************
** Accessors **
***************/
Type type() const { return (Type)_type; }
Code code() const { return (Code)_code; }
Genode::uint16_t checksum() const { return host_to_big_endian(_checksum); }
Genode::uint16_t query_id() const { return host_to_big_endian(_rest_of_header_u16[0]); }
Genode::uint16_t query_seq() const { return host_to_big_endian(_rest_of_header_u16[1]); }
Genode::uint32_t rest_of_header() const { return host_to_big_endian(_rest_of_header_u32[0]); }
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);
}
void copy_to_data(void const *base,
Genode::size_t size,
Size_guard &size_guard)
{
size_guard.consume_head(size);
Genode::memcpy(_data, base, size);
}
void type(Type v) { _type = (Genode::uint8_t)v; }
void code(Code v) { _code = (Genode::uint8_t)v; }
void checksum(Genode::uint16_t v) { _checksum = host_to_big_endian(v); }
void rest_of_header(Genode::uint32_t v) { _rest_of_header_u32[0] = host_to_big_endian(v); }
void query_id(Genode::uint16_t v) { _rest_of_header_u16[0] = host_to_big_endian(v); }
void query_seq(Genode::uint16_t v) { _rest_of_header_u16[1] = host_to_big_endian(v); }
/*********
** log **
*********/
void print(Genode::Output &output) const;
} __attribute__((packed));
#endif /* _NET__ICMP_H_ */