serenity/Kernel/Net/ICMP.h

#pragma once

#include <Kernel/Net/MACAddress.h>
#include <Kernel/Net/IPv4.h>

struct ICMPType {
enum {
    EchoReply = 0,
    EchoRequest = 8,
};
};

class [[gnu::packed]] ICMPHeader {
public:
    ICMPHeader() { }
    ~ICMPHeader() { }

    byte type() const { return m_type; }
    void set_type(byte b) { m_type = b; }

    byte code() const { return m_code; }
    void set_code(byte b) { m_code = b; }

    word checksum() const { return m_checksum; }
    void set_checksum(word w) { m_checksum = w; }

    const void* payload() const { return this + 1; }
    void* payload() { return this + 1; }

private:
    byte m_type { 0 };
    byte m_code { 0 };
    NetworkOrdered<word> m_checksum { 0 };
    // NOTE: The rest of the header is 4 bytes
};

static_assert(sizeof(ICMPHeader) == 4);

struct [[gnu::packed]] ICMPEchoPacket {
    ICMPHeader header;
    NetworkOrdered<word> identifier;
    NetworkOrdered<word> sequence_number;
    void* payload() { return this + 1; }
    const void* payload() const { return this + 1; }
};