genode/repos/os/include/net/ipv4.h
Martin Stein 365bd347a6 net: ICMP protocol
Packet format and common utilities for the Internet Control Message
Protocol.

Issue #2732
2018-04-10 11:11:52 +02:00

223 lines
6.6 KiB
C++

/*
* \brief Internet protocol version 4.
* \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 _IPV4_H_
#define _IPV4_H_
/* Genode */
#include <base/exception.h>
#include <util/string.h>
#include <util/token.h>
#include <util/endian.h>
#include <net/netaddress.h>
namespace Genode { class Output; }
namespace Net
{
enum { IPV4_ADDR_LEN = 4 };
class Ipv4_address;
class Ipv4_packet;
}
struct Net::Ipv4_address : Network_address<IPV4_ADDR_LEN, '.', false>
{
Ipv4_address(Genode::uint8_t value = 0) : Network_address(value) { }
Ipv4_address(void *src) : Network_address(src) { }
bool valid() const { return *this != Ipv4_address(); }
Genode::uint32_t to_uint32_big_endian() const;
static Ipv4_address from_uint32_big_endian(Genode::uint32_t ip_raw);
Genode::uint32_t to_uint32_little_endian() const;
static Ipv4_address from_uint32_little_endian(Genode::uint32_t ip_raw);
bool is_in_range(Ipv4_address const &first,
Ipv4_address const &last) const;
}
__attribute__((packed));
/**
* Data layout of this class conforms to an IPv4 packet (RFC 791)
*
* IPv4-header-format:
*
* ----------------------------------------------------------------
* | 0-3 | 4-7 | 8-11 | 12-15 | 16-18 | 19-23 | 24-27 | 28-31 |
* ----------------------------------------------------------------
* | version | IHL | service-type | total-length |
* ----------------------------------------------------------------
* | identifikation | flags | fragment-offset |
* ----------------------------------------------------------------
* | ttl | protocol | header-checksum |
* ----------------------------------------------------------------
* | source-ip-address |
* ----------------------------------------------------------------
* | destination-ip-address |
* ----------------------------------------------------------------
* | options ... |
* ----------------------------------------------------------------
*/
class Net::Ipv4_packet
{
public:
enum Size {
ADDR_LEN = IPV4_ADDR_LEN, /* Ip address length in bytes */
};
static const Ipv4_address CURRENT; /* current network */
static const Ipv4_address BROADCAST; /* broadcast address */
static Ipv4_address ip_from_string(const char *ip);
static Genode::uint16_t calculate_checksum(Ipv4_packet const &packet);
private:
/************************
** IPv4 header fields **
************************/
unsigned _header_length : 4;
unsigned _version : 4;
unsigned _diff_service : 6;
unsigned _ecn : 2;
Genode::uint16_t _total_length;
Genode::uint16_t _identification;
unsigned _flags : 3;
unsigned _fragment_offset : 13;
Genode::uint8_t _time_to_live;
Genode::uint8_t _protocol;
Genode::uint16_t _checksum;
Genode::uint8_t _src[ADDR_LEN];
Genode::uint8_t _dst[ADDR_LEN];
unsigned _data[0];
public:
enum class Protocol : Genode::uint8_t
{
ICMP = 1,
TCP = 6,
UDP = 17,
};
struct Bad_data_type : Genode::Exception { };
template <typename T> T const *data(Genode::size_t data_size) const
{
if (data_size < sizeof(T)) {
throw Bad_data_type();
}
return (T const *)(_data);
}
template <typename T> T *data(Genode::size_t data_size)
{
if (data_size < sizeof(T)) {
throw Bad_data_type();
}
return (T *)(_data);
}
/***************
** Accessors **
***************/
Genode::size_t header_length() const { return _header_length; }
Genode::uint8_t version() const { return _version; }
Genode::uint8_t diff_service() const { return _diff_service; }
Genode::uint8_t ecn() const { return _ecn; }
Genode::size_t total_length() const { return host_to_big_endian(_total_length); }
Genode::uint16_t identification() const { return host_to_big_endian(_identification); }
Genode::uint8_t flags() const { return _flags; }
Genode::size_t fragment_offset() const { return _fragment_offset; }
Genode::uint8_t time_to_live() const { return _time_to_live; }
Protocol protocol() const { return (Protocol)_protocol; }
Genode::uint16_t checksum() const { return host_to_big_endian(_checksum); }
Ipv4_address src() const { return Ipv4_address((void *)&_src); }
Ipv4_address dst() const { return Ipv4_address((void *)&_dst); }
void header_length(Genode::size_t v) { _header_length = v; }
void version(Genode::uint8_t v) { _version = v; }
void diff_service(Genode::uint8_t v) { _diff_service = v; ; }
void ecn(Genode::uint8_t v) { _ecn = v; ; }
void total_length(Genode::size_t v) { _total_length = host_to_big_endian((Genode::uint16_t)v); }
void identification(Genode::uint16_t v) { _identification = host_to_big_endian(v); }
void flags(Genode::uint8_t v) { _flags = v; ; }
void fragment_offset(Genode::size_t v) { _fragment_offset = v; ; }
void time_to_live(Genode::uint8_t v) { _time_to_live = v; }
void protocol(Protocol v) { _protocol = (Genode::uint8_t)v; }
void checksum(Genode::uint16_t checksum) { _checksum = host_to_big_endian(checksum); }
void src(Ipv4_address v) { v.copy(&_src); }
void dst(Ipv4_address v) { v.copy(&_dst); }
/*********
** log **
*********/
void print(Genode::Output &output) const;
} __attribute__((packed));
namespace Genode {
inline size_t ascii_to(char const *s, Net::Ipv4_address &result);
}
Genode::size_t Genode::ascii_to(char const *s, Net::Ipv4_address &result)
{
Net::Ipv4_address buf;
size_t number_idx = 0;
size_t read_len = 0;
while (1) {
/* read the current number, fail if there's no number */
size_t number_len = ascii_to_unsigned(s, buf.addr[number_idx], 10);
if (!number_len) {
return 0; }
/* update read length and number index */
read_len += number_len;
number_idx++;
/* if we have all numbers, fill result and return read length */
if (number_idx == sizeof(buf.addr) / sizeof(buf.addr[0])) {
result = buf;
return read_len;
}
/* as it was not the last number, check for the following dot */
s += number_len;
if (*s != '.') {
return 0; }
read_len++;
s++;
}
}
#endif /* _IPV4_H_ */