www.pudn.com > SNMP范例源代码.zip > inettype.h

union w{ 
	unsigned long dwords; 
	struct {unsigned int high;unsigned int low;}words; 
	struct {unsigned char byte3;unsigned char byte2;unsigned char byte1;unsigned char byte0;}bytes; 
}; 
 
union ethernet_address_type{ 
	unsigned int words[3]; 
	unsigned char bytes[6]; 
}; 
 
union ip_address_type{ 
	unsigned long dwords; 
	unsigned int words[2]; 
	unsigned char bytes[4]; 
}; 
 
union arp_table_type{ 
	unsigned char bytes[12]; 
	unsigned int words[6]; 
	struct{ 
		unsigned char status; 
		unsigned char ttl; 
		union ip_address_type ip_address; 
		union ethernet_address_type ethernet_address; 
	}arp;							//状态,生存时间,ip地址,以太网地址 
}; 
 
//以太网帧                   
struct ethernet{ 
	unsigned char status;			//接收状态 
	unsigned char nextpage;			//下一个页 
	unsigned int length;			//以太网长度，以字节为单位 
	unsigned int destnodeid[3];		//目的网卡地址 
	unsigned int sourcenodeid[3];	//源网卡地址 
	unsigned int protocal;			//下一层协议 
	unsigned char packet[1500];		//包的内容 
}; 
 
//IP包   仅当IHL=5时用 当不=5时作转换 
struct ip{ 
	unsigned int head[9];			//以太网包头 
	unsigned char verandihl;		//版本与头长度 
	unsigned char typeofserver;		//服务类型 
	unsigned int totallength;		//总长度 
	unsigned int frameindex;		//IP帧序号 
	unsigned int segment;			//分段标志 
	unsigned char ttl;				//生存时间 
	unsigned char protocal;			//下一层协议 
	unsigned int crc;				//校验和 
	unsigned int sourceip[2];		//源IP 
	unsigned int destip[2];			//目的IP 
	unsigned char packet[1484];		//IP包的内容 
}; 
 
struct ippacket{ 
	unsigned int head[9];			//以太网包头 
	unsigned int ippacket[750];		//IP包的内容 
}; 
                 
struct arp{ 
	unsigned int head[9];  			//以太网头 
//arp报文的内容总长28字节 
	unsigned int harewaretype;		//以太网为0x0001 
    unsigned int protocaltype;		//ip 为0X0800 
    unsigned char halength;			//=0X06 
    unsigned char palength;			//=0X04 
    unsigned int operation;			//操作  0X0001为请求 0X0002为应答 0X0003为反向地址请求 0X0004为反向地址应答 
    unsigned int sourcenodeid[3];	//源网卡地址 
	unsigned int sourceip[2];		//源IP地址 
    unsigned int destnodeid[3];		//目的网卡地址 
	unsigned int destip[2];			//目的IP地址 
};  
 
struct icmp{						//包含在IP包中，是IP的上层为0X01的应用 
	unsigned int head[9];			//以太网头 
    unsigned int iphead[10];		//IP头 
    unsigned char type;				//0X08 PING请求 0X00 PING应答 
    unsigned char option;			//0X00 PING 
    unsigned int crc;       
    unsigned int id; 
    unsigned int seq; 
    unsigned char icmpdata[1472]; 
}; 
 
struct tcp{ 
	unsigned int head[9]; 
    unsigned int iphead[10]; 
    unsigned int sourceport;		//源端口 
    unsigned int destport;			//目的端口 
    unsigned long seqnumber;		//顺序号 
	unsigned long acknumber;		//确认号 
    unsigned char offset;			//数据偏移量 
    unsigned char control;			//连接控制 
    unsigned int window;			//流控 
    unsigned int crc;				//校验和 ，包括伪头部，TCP头部，数据 
    unsigned int urg;				//紧急指针 
    unsigned char tcpdata[1460];	//TCP数据 
}; 
 
struct udp{ 
	unsigned int head[9]; 
    unsigned int iphead[10]; 
    unsigned int sourceport;		//源端口 
    unsigned int destport;			//目的端口 
    unsigned int length;     
    unsigned int crc;				//校验和 ，包括伪头部，udp头部，数据 
    unsigned char udpdata[1472];	//udp数据 
}; 
              
//所有协议的共用体 
union netcard{ 
	struct {unsigned char  bytebuf[1536];}bytes; 
    struct{ unsigned int wordbuf[768];}words; 
    struct ethernet etherframe;	 
    struct arp arpframe; 
    struct icmp icmpframe; 
    struct tcp tcpframe;   
    struct ip ipframe; 
	struct udp udpframe; 
    struct ippacket ippacket; 
};