#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?

#define?BUFLEN?1000
#define?PORT?8848

typedef?struct?ip_hdr{//ipv4頭部?
	unsigned?int?ip_length:4;?/*little-endian*/
	unsigned?int?ip_version:4;
	unsigned?char?ip_tos;
	unsigned?short?ip_total_length;
	unsigned?short?ip_id;
	unsigned?short?ip_flags;
	unsigned?char?ip_ttl;
	unsigned?char?ip_protocol;
	unsigned?short?ip_cksum;
	unsigned?int?ip_source;
	unsigned?int?ip_dest;
}ip_hdr;

typedef?struct?udp_hdr{//udp頭部
	unsigned?short?s_port;
	unsigned?short?d_port;
	unsigned?short?length;
	unsigned?short?cksum;
}udp_hdr;

typedef?struct?psd_header{//偽頭部，用于計算校驗和

	unsigned?int?s_ip;//source?ip

	unsigned?int?d_ip;//dest?ip

	unsigned?char?mbz;//0

	unsigned?char?proto;//proto?type

	unsigned?short?plen;//length

}psd_header;

unsigned?short?checksum（unsigned?short*?buffer?int?size）//校驗和
{
	unsigned?long?cksum?=?0;
	while（size>1）{
		cksum?+=?*buffer++;
		size?-=?sizeof（unsigned?short）;
	}
	if（size）{
		cksum?+=?*（unsigned?char*）buffer;
	}
	cksum?=?（cksum>>16）?+?（cksum&0xffff）;?//將高16bit與低16bit相加

	cksum?+=?（cksum>>16）;?//將進位到高位的16bit與低16bit?再相加

	return?（unsigned?short）（~cksum）;
}

int?main（int?argc?char?*argv[]）
{
	char?buf[BUFLEN];
	int?sockfd?=?-1;
			????
	struct?sockaddr_in6?host_addr;
	if（（sockfd?=?socket（AF_INET6?SOCK_RAW?IPPROTO_IPIP））<0）{
		perror（“socket（）?error:“）;
		exit（1）;
	}

	bzero（&host_addrsizeof（host_addr