TCPIP协议头部结构体.docxVIP

TCP/IP协议头部结构体?网络协议结构体定义//?i386?is?little_endian.???#ifndef?LITTLE_ENDIAN???#define?LITTLE_ENDIAN???(1)???//BYTE?ORDER???#else???#error?Redefine?LITTLE_ORDER???#endif???//Mac头部，总长度14字节???typedef?struct?_eth_hdr??{??????unsigned?char?dstmac[6];?//目标mac地址???????unsigned?char?srcmac[6];?//源mac地址???????unsigned?short?eth_type;?//以太网类型???}eth_hdr;??//IP头部，总长度20字节???typedef?struct?_ip_hdr??{??????#if?LITTLE_ENDIAN???????unsigned?char?ihl:4;?????//首部长度???????unsigned?char?version:4,?//版本????????#else???????unsigned?char?version:4,?//版本???????unsigned?char?ihl:4;?????//首部长度???????#endif???????unsigned?char?tos;???????//服务类型???????unsigned?short?tot_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_hdr;??//TCP头部，总长度20字节???typedef?struct?_tcp_hdr??{??????unsigned?short?src_port;????//源端口号???????unsigned?short?dst_port;????//目的端口号???????unsigned?int?seq_no;????????//序列号???????unsigned?int?ack_no;????????//确认号???????#if?LITTLE_ENDIAN???????unsigned?char?reserved_1:4;?//保留6位中的4位首部长度???????unsigned?char?thl:4;????????//tcp头部长度???????unsigned?char?flag:6;???????//6位标志???????unsigned?char?reseverd_2:2;?//保留6位中的2位???????#else???????unsigned?char?thl:4;????????//tcp头部长度???????unsigned?char?reserved_1:4;?//保留6位中的4位首部长度???????unsigned?char?reseverd_2:2;?//保留6位中的2位???????unsigned?char?flag:6;???????//6位标志????????#endif???????unsigned?short?wnd_size;????//16位窗口大小???????unsigned?short?chk_sum;?????//16位TCP检验和???????unsigned?short?urgt_p;??????//16为紧急指针???}tcp_hdr;??//UDP头部，总长度8字节???typedef?struct?_udp_hdr??{??????unsigned?short?src_port;?//远端口号???????unsigned?short?dst_port;?//目的端口号???????unsigned?short?uhl;??????//udp头部长度???????unsigned?short?chk_sum;??//16位udp检验和???}udp_hdr;??//ICMP头部，总长度4字节???typedef?struct?_icmp_hdr??{??????unsigned?char?icmp_type;???//类型???