c++ 常见网络协议头

//NTP协议
typedef struct _NTP_HEADER
{
    uint8_t _flags;//Flags  0xdb
    uint8_t _pcs;//Peer Clock Stratum
    uint8_t _ppt;//Peer Polling Interval
    uint8_t _pcp;//Peer Clock Precision
    uint32_t _rdy;//Root Delay
    uint32_t _rdn;//Root Dispersion
    uint32_t _rid;//Reference ID
    uint64_t _ret;//Reference Timestamp
    uint64_t _ort;//Origin Timestamp
    uint64_t _rct;//Receive Timestamp
    uint64_t _trt;//Transmit Timestamp
}ntp_header,*pntp_header;

//MAC协议
typedef struct _MAC_HEADER
{
    unsigned char dstmac[];//目的MAC
    unsigned char srcmac[];//源MAC
    unsigned short type;//协议
}mac_header,*pmac_header;

//ARP协议
typedef struct _ARP_HEADER
{
    unsigned short hardware;//硬件类型
    unsigned short protocol;//协议类型
    unsigned char hardwarelen;//硬件地址长度(6)
    unsigned char protocollen;//协议地址长度(4)
    unsigned short operate;//操作类型(1-ARP请求 2-ARP应答 3-RARP请求 4-RARP应答)
    unsigned char sendmac[];//发送端MAC地址
    in_addr sendip;//发送端IP地址
    unsigned char dstmac[];//目的端MAC地址
    in_addr dstip;//目的端IP地址
}arp_header,*parp_header;

//RARP协议
typedef struct _RARP_HEADER
{
    unsigned short hardware;//硬件类型
    unsigned short protocol;//协议类型
    unsigned char hardwarelen;//硬件地址长度(6)
    unsigned char protocollen;//协议地址长度(4)
    unsigned short operate;//操作类型(1-ARP请求 2-ARP应答 3-RARP请求 4-RARP应答)
    unsigned char sendmac[];//发送端MAC地址
    unsigned char sendip[];//发送端IP地址
    unsigned char dstmac[];//目的端MAC地址
    unsigned char dstip[];//目的端IP地址
}rarp_header,prarp_header;

//IP协议
typedef struct _IP_HEADER
{
    unsigned char headerlen:;   //首部长度
    unsigned char version:; //版本
    unsigned char tos;   //服务类型
    unsigned short total_len; //总长度
    unsigned short id;    //标志
    unsigned short frag_off; //分片偏移
    unsigned char ttl;   //生存时间
    unsigned char protocol; //协议
    unsigned short chk_sum; //检验和
    struct in_addr srcaddr; //源IP地址
    struct in_addr dstaddr; //目的IP地址
}ip_header,*pip_header;

//TCP协议
typedef struct _TCP_HEADER
{
    unsigned short srcport;//源端口
    unsigned short dstport;//目的端口
    unsigned int seq_no;//序列号
    unsigned int ack_no;//确认号
    unsigned char reserved_1:;//保留位
    unsigned char headerlen:;//协议头长度
    unsigned char flag:;//6位标志
    unsigned char reserved_2:;//保留位
    unsigned short wnd_size;//窗口大小
    unsigned short chk_sum;//校验和
    unsigned short urgt_p;//紧急指针
}tcp_header,*ptcp_header;

//UDP协议
typedef struct _UDP_HEADER
{
    unsigned short srcport;//源端口号
    unsigned short dstport;//目的端口号
    unsigned short headerlen;//UDP长度
    unsigned short chk_sum;//校验和
}udp_header,*pudp_header;

//ICMP协议
typedef struct _ICMP_HEADER
{
    unsigned char type;//类型
    unsigned char code;//代码
    unsigned short chk_sum;//校验和
}icmp_header,*picmp_header;

//IGMP
typedef struct _IGMP_HEADER
{
    unsigned char type:;//类型
    unsigned char version:;//版本
    unsigned char reserved;//未用
    unsigned short chk_sum;//校验和
    in_addr addr;//D类IP地址
}igmp_header,*pigmp_header;