inetproto.h

// 데이터링크 계층(레이어 2) 프로토콜 타입 정의
// 이더넷

#ifndef _INETPROTO_H__
#define _INETPROTO_H__

#include <stdint.h>
#include <iostream>
// ethernet------------------------------------

#define ETHERNETHEADER_LENGTH   14
#define MACADDRESS_LENGTH       6
#define IPV4ADDRESS_LENGTH      4

enum ETHTYPE
{
    NOTING  = 0x0,
    IPV4    = 0x0800,
    ARP     = 0x0806,
    RARP    = 0x8035,
    WAKEONLAN = 0x0842,
    IPV6    = 0x86DD,

    MACSECURITY = 0x88E5,
    PROTOCOLTYPEEND = 0x10000
};

struct ETHHeader
{
    uint8_t srcmac[6];
    uint8_t dstmac[6];
    uint16_t prototype;
};

// ARP-------------------------------------------
// ARP 하드웨어 타입
#define ARPMESSAGE_LENGTH   60
#define ARPHEADER_LENGTH    28

enum ARPHRD
{
    ETHERNET    = 1,
    IEEE802     = 6,
    ARCNET      = 7,
    HYPERCHNNEL = 8,
    LANSTAR     = 9,
    ARPHRDEND
};

// ARP OPCODE 종류
enum ARPOPCODE
{
    ARPREQUEST = 1,
    ARPREPLY = 2,
    RARPREQUEST = 3,
    RARPREPLY = 4,
    DRARPREQUEST = 5,
    DRARPREPLY = 6,
    INARPREQUEST = 7,
    INARPREPLY = 8,
    ARPOPCODEEND
};

// ARP 메시지 포맷
typedef struct ARPPacket
{
    uint16_t    htype;
    uint16_t    ptype;
    uint8_t     hlen;
    uint8_t     plen;
    uint16_t    opcode;
    uint8_t     shaddr[6];
    uint8_t     spaddr[4];
    uint8_t     dhaddr[6];
    uint8_t     dpaddr[4];
} ARPPacket, *PARPPacket;


void SetARPPacket(uint8_t *out,
        uint8_t htype,
        uint8_t ptype,
        uint8_t hlen,
        uint8_t plen,
        uint16_t opcode,
        uint8_t *srcmac,
        uint8_t *srcip,
        uint8_t *dstmac,
        uint8_t *dstip
        );

void SetARPRequest(uint8_t* out,
        uint8_t *srcmac,
        uint8_t *srcip,
        uint8_t *dstmac,
        uint8_t *dstip);

// IPV4----------------------------------------

enum IPV4TYPE
{
    HOTOPT = 0,
    ICMP = 1,
    IGMP = 2,
    GGP = 3,
    IPV4_IPV4 = 4,
    ST = 5,
    TCP = 6,
    CBT = 7,
    EGP = 8,
    IGP = 9,
    BBN_RCC_MON = 10,
    NVP_2 = 11,
    PUP = 12,
    ARGUS = 13,
    EMCON = 14,
    CHAOS = 16,
    UDP = 17,

    IPV6_IPV4 = 41,

    RESERVED = 255,

    END
};

#define IPV4HEADER_BASICLENGTH  20  // bytes
#define IPV4HEADER_MAX_LENGTH   60  // bytes

#define SETRESERVED(bit)
#define SETDF(bit)
#define SETMF(bit)
#define SETFLAGSOFF()
typedef struct IPV4Header
{
    uint8_t     headerlen : 4;  // IP 버전
    uint8_t     version : 4;        // IP 헤더 길이(옵션 포함길이)
    uint8_t     tos;            // type of service
    uint16_t    totallen;       // IP전체 길이
    uint16_t    identification; //6b

    uint16_t    flags;

    uint8_t     ttl;
    uint8_t     protoid;
    uint16_t    checksum;
    uint8_t     srcaddr[4];
    uint8_t     dstaddr[4];
    //uint32_t  option;     //옵션이 가변 길이 ihl로 확인
}IPV4Header, *PIPV4Header;

// IP Header Checksum 계산
// @ iph_len: byte단위 헤더 길이
// @ piph: 헤더 시작 위치
uint16_t IPHeaderChecksum(uint16_t iph_len, uint8_t *piph);


// ICMP----------------------------------------
enum ICMPV4TYPE
{
    ICMPV4_ECHO_REPLY       = 0,
    ICMPV4_DST_UNREACH      = 3,        // Destination Unrechable
    ICMPV4_REDIRECT         = 5,
    ICMPV4_ECHO_REQUEST     = 8,
    ICMPV4_ROUTER_AD        = 9,
    ICMPV4_ROUTER_SOLICIT   = 10,
    ICMPV4_TIMESTAMP_REQUEST    = 13,
    ICMPV4_TIMESTAMP_REPLY = 14,
    ICMPV4_INFO_REQUEST     = 15,
    ICMPV4_INFO_REPLY       = 16,
    ICMPV4_MASK_REQUEST     = 17, // Address Mask Request.
    ICMPV4_MASK_REPLY       = 18, // Address Mask Reply.
    ICMPV4_MOBILE_REG_REQUEST   = 35,   // Mobile Registration request
    ICMPV4_MOBILE_REG_REPLY = 36    // Mobile Registration reply
};

#define ICMPV4HEADER_LENGTH     8   // bytes
#define ICMPV4ECHO_LENGTH       40
// ICMPV4 헤더 체크섬 계산
// @ len: 헤더의 길이(ip 전체길이 - ip헤더 길이)
// @ picmph: 헤더의 위치
#define ICMPV4HeaderChecksum(len, picmph)       IPHeaderChecksum(len, picmph)

typedef struct ICMPV4Header
{
    uint8_t     type;
    uint8_t     code;
    uint16_t    checksum;
    uint16_t    identifier;
    uint16_t    seqnum;
    // + 데이터
}ICMPV4Header, *PICMPV4Header;

// TCP------------------------

typedef struct PseudoHeader
{
    uint32_t  src_addr; //IP의 source address
    uint32_t  dst_addr; //IP의 dest address
    uint8_t  useless;   //예약된 필드(0x00)
    uint8_t  protocol;  //IP의 Protocol
    uint16_t length;        // tcp : (ip total lenth)-(ip header length)   udp : udp_header len;
}PseudoHeader;

typedef struct TCPHeader
{
    uint16_t    srcport;
    uint16_t    dstport;
    uint32_t    seqnum;
    uint32_t    acknum;
    uint16_t    dataoff : 4;
    uint16_t    reserved : 3;
    uint16_t    flags : 9;
    uint16_t    window;
    uint16_t    checksum;
    uint16_t    urgpointer;

} TCPHeader, *PTCPHeader;


// UDP------------------------

#define UDPHEADER_LENGTH    8

typedef struct UDPHeader
{
    uint16_t    srcport;
    uint16_t    dstport;
    uint16_t    udplen;
    uint16_t    checksum;
} UDPHeader, *PUDPHeader;

#endif  // _INETPROTO_H__ //