#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define?PACKET_SIZE?4096
#define?MAX_WAIT_TIME?5
char?sendpacket[PACKET_SIZE];
char?recvpacket[PACKET_SIZE];
double?max_time=0min_time=10000sum_time=0;
int?show_pro=1iobyname=0;
struct?timeval?start_timeend_time;
int?sockfddatalen=56;
int?send_count=4send_interval=1nTTL=-1route_count=-1route_TTL=1;
int?nsend=0nreceived=0npack=0;
struct?sockaddr_in?dest_addr;
pid_t?pid;
struct?sockaddr_in?from;
struct?timeval?tvrecv;
void?statistics（int?signo）;
unsigned?short?cal_chksum（unsigned?short?*addr?int?len）;
int?pack（int?pack_no）;
int?send_packet（void）;
int?recv_packet（void）;
int?unpack（char*?buf?int?len）;
void?tv_sub（struct?timeval?*out?struct?timeval?*in）;
void?cal_time（double?rtt）;
void?commandhelp（）;
void?send_recv（）;




void?statistics（int?signo）
{
	printf（“\n-------------------PING?statistics----------------\n“）;
	printf（“%d?packets?transmitted??%d?received?%.1f%%?lost\n?“
			nsendnreceived（（float）nsend-（float）nreceived）/（float）nsend*100）;
	if（?（max_time!=0）?&&?（sum_time!=0）?）
		printf（“rtt?min/avg/max?=?%.3f?%.3f?%.3f?\n“
				min_timesum_time/nreceivedmax_time）;
	close（sockfd）;
	exit（0）;
}

/*校驗和算法*/
unsigned?short?cal_chksum（unsigned?short?*addrint?len）
{
	int?nleft=len;
	int?sum=0;
	unsigned?short?*w=addr;
	unsigned?short?answer=0;
	while（nleft>1）/*把ICMP報頭二進制數據以2字節為單位加起來*/
	{
		sum+=*w++;
		nleft-=2;
	}
	if（?nleft==1?）
	{
		*（unsigned?char?*）（&answer）?=?*（unsigned?char?*）w;
		sum+=answer;
	}
	sum=（sum>>16）+（sum&0xffff）;
	sum+=（sum>>16）;
	answer=~sum;
	return?answer;
}

/*設置ICMP報頭*/
int?pack（int?pack_no）
{
	int?ipacksize;
	struct?icmp?*icmp;
	struct?timeval?*tval;
	icmp=（struct?icmp*）sendpacket;
	icmp->icmp_type=ICMP_ECHO;
	icmp->icmp_code=0;
	icmp->icmp_cksum=0;
	icmp->icmp_seq=pack_no;
	icmp->icmp_id=pid;
	packsize=8+datalen;
	tval?=?（struct?timeval?*）icmp->icmp_data;
	gettimeofday（tvalNULL）;/*記錄發送時間*/
	icmp->icmp_cksum=cal_chksum（（unsigned?short?*）icmppacksize）;/*校驗算法*/
	return?packsize;	
}

int?send_packet（）
{
	int?packetsize;
	npack++;
	packetsize=pack（npack）;/*設置ICMP報頭*/
	if（?sendto（?sockfd?sendpacket?packetsize?0
		（struct?sockaddr?*）&dest_addrsizeof（dest_addr））?<0?）
	{
		perror（“sendto?error“）;
		return?-1;
	}
	return?0;
}

/*接受報文*/
int?recv_packet（）
{
	int?nfromlen;
	extern?int?errno;
	
	signal（SIGALRMstatistics）;
	signal（SIGINTstatistics）;
	fromlen=sizeof（from）;
	alarm（MAX_WAIT_TIME）;
		if（?（?n=recvfrom（sockfdrecvpacketsizeof（recvpacket）0
			（struct?sockaddr*）&from&fromlen））<0?）
		{
			if（?errno==EINTR?）?
			perror（“recvfrom?error“）;
			return?-1;
		}	
		gettimeofday（&tvrecvNULL）;/*記錄接收時間*/
		if（unpack（recvpacketn）==0）
			return?0;
		return?-1;
}

/*剝去ICMP報頭*/
int?unpack（char?*bufint?len）
{
	int?iiphdrlen;
	struct?ip?*ip;
	struct