ICMP network packet: C++98/STL parsing library

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of ICMP network packet using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime library

All parsing code for C++98/STL generated by Kaitai Struct depends on the C++/STL runtime library. You have to install it before you can parse data.

For C++, the easiest way is to clone the runtime library sources and build them along with your project.

Code

Using Kaitai Struct in C++/STL usually consists of 3 steps.

We need to create an STL input stream (std::istream). One can open local file for that, or use existing std::string or char* buffer.

#include <fstream>

std::ifstream is("path/to/local/file.bin", std::ifstream::binary);

#include <sstream>

std::istringstream is(str);

#include <sstream>

const char buf[] = { ... };
std::string str(buf, sizeof buf);
std::istringstream is(str);

We need to wrap our input stream into Kaitai stream:

#include "kaitai/kaitaistream.h"

kaitai::kstream ks(&is);

And finally, we can invoke the parsing:
```
icmp_packet_t data(&ks);
```

After that, one can get various attributes from the structure by invoking getter methods like:

data.icmp_type() // => get icmp type

C++98/STL source code to parse ICMP network packet

icmp_packet.h

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#ifndef ICMP_PACKET_H_
#define ICMP_PACKET_H_

// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

#include "kaitai/kaitaistruct.h"
#include <stdint.h>

#if KAITAI_STRUCT_VERSION < 9000L
#error "Incompatible Kaitai Struct C++/STL API: version 0.9 or later is required"
#endif

class icmp_packet_t : public kaitai::kstruct {

public:
    class destination_unreachable_msg_t;
    class time_exceeded_msg_t;
    class echo_msg_t;

    enum icmp_type_enum_t {
        ICMP_TYPE_ENUM_ECHO_REPLY = 0,
        ICMP_TYPE_ENUM_DESTINATION_UNREACHABLE = 3,
        ICMP_TYPE_ENUM_SOURCE_QUENCH = 4,
        ICMP_TYPE_ENUM_REDIRECT = 5,
        ICMP_TYPE_ENUM_ECHO = 8,
        ICMP_TYPE_ENUM_TIME_EXCEEDED = 11
    };

    icmp_packet_t(kaitai::kstream* p__io, kaitai::kstruct* p__parent = 0, icmp_packet_t* p__root = 0);

private:
    void _read();
    void _clean_up();

public:
    ~icmp_packet_t();

    class destination_unreachable_msg_t : public kaitai::kstruct {

    public:

        enum destination_unreachable_code_t {
            DESTINATION_UNREACHABLE_CODE_NET_UNREACHABLE = 0,
            DESTINATION_UNREACHABLE_CODE_HOST_UNREACHABLE = 1,
            DESTINATION_UNREACHABLE_CODE_PROTOCOL_UNREACHABLE = 2,
            DESTINATION_UNREACHABLE_CODE_PORT_UNREACHABLE = 3,
            DESTINATION_UNREACHABLE_CODE_FRAGMENTATION_NEEDED_AND_DF_SET = 4,
            DESTINATION_UNREACHABLE_CODE_SOURCE_ROUTE_FAILED = 5,
            DESTINATION_UNREACHABLE_CODE_DST_NET_UNKOWN = 6,
            DESTINATION_UNREACHABLE_CODE_SDT_HOST_UNKOWN = 7,
            DESTINATION_UNREACHABLE_CODE_SRC_ISOLATED = 8,
            DESTINATION_UNREACHABLE_CODE_NET_PROHIBITED_BY_ADMIN = 9,
            DESTINATION_UNREACHABLE_CODE_HOST_PROHIBITED_BY_ADMIN = 10,
            DESTINATION_UNREACHABLE_CODE_NET_UNREACHABLE_FOR_TOS = 11,
            DESTINATION_UNREACHABLE_CODE_HOST_UNREACHABLE_FOR_TOS = 12,
            DESTINATION_UNREACHABLE_CODE_COMMUNICATION_PROHIBITED_BY_ADMIN = 13,
            DESTINATION_UNREACHABLE_CODE_HOST_PRECEDENCE_VIOLATION = 14,
            DESTINATION_UNREACHABLE_CODE_PRECEDENCE_CUTTOFF_IN_EFFECT = 15
        };

        destination_unreachable_msg_t(kaitai::kstream* p__io, icmp_packet_t* p__parent = 0, icmp_packet_t* p__root = 0);

    private:
        void _read();
        void _clean_up();

    public:
        ~destination_unreachable_msg_t();

    private:
        destination_unreachable_code_t m_code;
        uint16_t m_checksum;
        icmp_packet_t* m__root;
        icmp_packet_t* m__parent;

    public:
        destination_unreachable_code_t code() const { return m_code; }
        uint16_t checksum() const { return m_checksum; }
        icmp_packet_t* _root() const { return m__root; }
        icmp_packet_t* _parent() const { return m__parent; }
    };

    class time_exceeded_msg_t : public kaitai::kstruct {

    public:

        enum time_exceeded_code_t {
            TIME_EXCEEDED_CODE_TIME_TO_LIVE_EXCEEDED_IN_TRANSIT = 0,
            TIME_EXCEEDED_CODE_FRAGMENT_REASSEMBLY_TIME_EXCEEDED = 1
        };

        time_exceeded_msg_t(kaitai::kstream* p__io, icmp_packet_t* p__parent = 0, icmp_packet_t* p__root = 0);

    private:
        void _read();
        void _clean_up();

    public:
        ~time_exceeded_msg_t();

    private:
        time_exceeded_code_t m_code;
        uint16_t m_checksum;
        icmp_packet_t* m__root;
        icmp_packet_t* m__parent;

    public:
        time_exceeded_code_t code() const { return m_code; }
        uint16_t checksum() const { return m_checksum; }
        icmp_packet_t* _root() const { return m__root; }
        icmp_packet_t* _parent() const { return m__parent; }
    };

    class echo_msg_t : public kaitai::kstruct {

    public:

        echo_msg_t(kaitai::kstream* p__io, icmp_packet_t* p__parent = 0, icmp_packet_t* p__root = 0);

    private:
        void _read();
        void _clean_up();

    public:
        ~echo_msg_t();

    private:
        std::string m_code;
        uint16_t m_checksum;
        uint16_t m_identifier;
        uint16_t m_seq_num;
        std::string m_data;
        icmp_packet_t* m__root;
        icmp_packet_t* m__parent;

    public:
        std::string code() const { return m_code; }
        uint16_t checksum() const { return m_checksum; }
        uint16_t identifier() const { return m_identifier; }
        uint16_t seq_num() const { return m_seq_num; }
        std::string data() const { return m_data; }
        icmp_packet_t* _root() const { return m__root; }
        icmp_packet_t* _parent() const { return m__parent; }
    };

private:
    icmp_type_enum_t m_icmp_type;
    destination_unreachable_msg_t* m_destination_unreachable;
    bool n_destination_unreachable;

public:
    bool _is_null_destination_unreachable() { destination_unreachable(); return n_destination_unreachable; };

private:
    time_exceeded_msg_t* m_time_exceeded;
    bool n_time_exceeded;

public:
    bool _is_null_time_exceeded() { time_exceeded(); return n_time_exceeded; };

private:
    echo_msg_t* m_echo;
    bool n_echo;

public:
    bool _is_null_echo() { echo(); return n_echo; };

private:
    icmp_packet_t* m__root;
    kaitai::kstruct* m__parent;

public:
    icmp_type_enum_t icmp_type() const { return m_icmp_type; }
    destination_unreachable_msg_t* destination_unreachable() const { return m_destination_unreachable; }
    time_exceeded_msg_t* time_exceeded() const { return m_time_exceeded; }
    echo_msg_t* echo() const { return m_echo; }
    icmp_packet_t* _root() const { return m__root; }
    kaitai::kstruct* _parent() const { return m__parent; }
};

#endif  // ICMP_PACKET_H_

icmp_packet.cpp

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// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

#include "icmp_packet.h"
#include "kaitai/exceptions.h"

icmp_packet_t::icmp_packet_t(kaitai::kstream* p__io, kaitai::kstruct* p__parent, icmp_packet_t* p__root) : kaitai::kstruct(p__io) {
    m__parent = p__parent;
    m__root = this;
    m_destination_unreachable = 0;
    m_time_exceeded = 0;
    m_echo = 0;

    try {
        _read();
    } catch(...) {
        _clean_up();
        throw;
    }
}

void icmp_packet_t::_read() {
    m_icmp_type = static_cast<icmp_packet_t::icmp_type_enum_t>(m__io->read_u1());
    n_destination_unreachable = true;
    if (icmp_type() == icmp_packet_t::ICMP_TYPE_ENUM_DESTINATION_UNREACHABLE) {
        n_destination_unreachable = false;
        m_destination_unreachable = new destination_unreachable_msg_t(m__io, this, m__root);
    }
    n_time_exceeded = true;
    if (icmp_type() == icmp_packet_t::ICMP_TYPE_ENUM_TIME_EXCEEDED) {
        n_time_exceeded = false;
        m_time_exceeded = new time_exceeded_msg_t(m__io, this, m__root);
    }
    n_echo = true;
    if ( ((icmp_type() == icmp_packet_t::ICMP_TYPE_ENUM_ECHO) || (icmp_type() == icmp_packet_t::ICMP_TYPE_ENUM_ECHO_REPLY)) ) {
        n_echo = false;
        m_echo = new echo_msg_t(m__io, this, m__root);
    }
}

icmp_packet_t::~icmp_packet_t() {
    _clean_up();
}

void icmp_packet_t::_clean_up() {
    if (!n_destination_unreachable) {
        if (m_destination_unreachable) {
            delete m_destination_unreachable; m_destination_unreachable = 0;
        }
    }
    if (!n_time_exceeded) {
        if (m_time_exceeded) {
            delete m_time_exceeded; m_time_exceeded = 0;
        }
    }
    if (!n_echo) {
        if (m_echo) {
            delete m_echo; m_echo = 0;
        }
    }
}

icmp_packet_t::destination_unreachable_msg_t::destination_unreachable_msg_t(kaitai::kstream* p__io, icmp_packet_t* p__parent, icmp_packet_t* p__root) : kaitai::kstruct(p__io) {
    m__parent = p__parent;
    m__root = p__root;

    try {
        _read();
    } catch(...) {
        _clean_up();
        throw;
    }
}

void icmp_packet_t::destination_unreachable_msg_t::_read() {
    m_code = static_cast<icmp_packet_t::destination_unreachable_msg_t::destination_unreachable_code_t>(m__io->read_u1());
    m_checksum = m__io->read_u2be();
}

icmp_packet_t::destination_unreachable_msg_t::~destination_unreachable_msg_t() {
    _clean_up();
}

void icmp_packet_t::destination_unreachable_msg_t::_clean_up() {
}

icmp_packet_t::time_exceeded_msg_t::time_exceeded_msg_t(kaitai::kstream* p__io, icmp_packet_t* p__parent, icmp_packet_t* p__root) : kaitai::kstruct(p__io) {
    m__parent = p__parent;
    m__root = p__root;

    try {
        _read();
    } catch(...) {
        _clean_up();
        throw;
    }
}

void icmp_packet_t::time_exceeded_msg_t::_read() {
    m_code = static_cast<icmp_packet_t::time_exceeded_msg_t::time_exceeded_code_t>(m__io->read_u1());
    m_checksum = m__io->read_u2be();
}

icmp_packet_t::time_exceeded_msg_t::~time_exceeded_msg_t() {
    _clean_up();
}

void icmp_packet_t::time_exceeded_msg_t::_clean_up() {
}

icmp_packet_t::echo_msg_t::echo_msg_t(kaitai::kstream* p__io, icmp_packet_t* p__parent, icmp_packet_t* p__root) : kaitai::kstruct(p__io) {
    m__parent = p__parent;
    m__root = p__root;

    try {
        _read();
    } catch(...) {
        _clean_up();
        throw;
    }
}

void icmp_packet_t::echo_msg_t::_read() {
    m_code = m__io->read_bytes(1);
    if (!(code() == std::string("\x00", 1))) {
        throw kaitai::validation_not_equal_error<std::string>(std::string("\x00", 1), code(), _io(), std::string("/types/echo_msg/seq/0"));
    }
    m_checksum = m__io->read_u2be();
    m_identifier = m__io->read_u2be();
    m_seq_num = m__io->read_u2be();
    m_data = m__io->read_bytes_full();
}

icmp_packet_t::echo_msg_t::~echo_msg_t() {
    _clean_up();
}

void icmp_packet_t::echo_msg_t::_clean_up() {
}