大家帮我看下这段ping的小程序哪里有问题？

[堕落的乞讨者]

/*
 * dealPing.cpp
 *
 *  Created on: 2013-4-11
 *      Author: root
 */
#include <sys/select.h>
#include <unistd.h>
#include <sys/time.h>
#include "CoreCommon.h"
#include <ace/OS_NS_arpa_inet.h>
#include <string>

#define ICMP_ECHOREPLY 	0
#define ICMP_ECHO 		8
#define ICMP_TIMEOUT 	11           // Time out ICMP Packet 
#define REQ_DATASIZE 	4096
#define MAXICMPLEN 		4096
#define DEF_PACKET		32
#define MAXPACKET		65535	/*IP包的最大大小*/
#define UDPPACKETSIZE	36		/*UDP数据报的大小*/
#define SRCPORT			23156	/*UDP包的源端口*/
#define DSTPORT			5812	/*UDP包的目的端口*/

#define MAX_PATHLEN 	255

//IP及ICMP包头部结构
typedef struct ip_head{
	u32	HeadLen:4;	//用32位字表示的报头长度
	u32	version:4;	//协议版本
	u8	level;		//优先级
	u16	len;		//包长度
	u16	ID;			//标识
	u16	mflag;		//其它标记
	u8	ttl;		//生命期
	u8	prot;		//协议
	u16	cksum;		//检查和
	u32	sourIP;	    //源IP地址
	u32	destIP;		//目的IP地址
}IPHDR, *PIPHDR;

typedef struct tagICMPHDR
{
		u8 Type; // Type
		u8 Code; // Code
		u16 Checksum; // Checksum
		u16 ID; // Identification
		u16 Seq; // Sequence
		u16 number; //计数值
		u16 time; //时间
		char Data; //Data
} ICMPHDR, *PICMPHDR;

// ICMP Echo Request
typedef struct tagECHOREQUEST
{
		ICMPHDR icmpHdr;
		struct timeval echoTime;
		char cData[1];
} ECHOREQUEST, *PECHOREQUEST;

// ICMP Echo Reply
typedef struct tagECHOREPLY
{
		IPHDR ipHdr;
		ECHOREQUEST echoRequest;
		char cFiller[MAXICMPLEN];
} ECHOREPLY, *PECHOREPLY;

/****************************************************************************
函数名称:checksum
函数功能:计算校验和
输入:
		buffer:	数据缓冲
		size:	缓冲大小

输出:无
返回值: 校验和
特殊说明:
****************************************************************************/
u16 checksum(u16 *buffer, int size)
{
	unsigned long cksum=0;
	while(size >1)
	{
		cksum+=*buffer++;
		size -=sizeof(unsigned short);
	} 
	if(size)
	{
		cksum += *(unsigned char*)buffer;
	}
	cksum = (cksum >> 16) + (cksum & 0xffff);
	cksum += (cksum >>16);
	return (unsigned short)(~cksum);
}

/*timeval*/ 
void tv_sub(struct timeval *out,struct timeval *in) 
{
	if( (out->tv_usec-=in->tv_usec)<0) 
	{
		--out->tv_sec; 
		out->tv_usec+=1000000; 
	} 
	out->tv_sec-=in->tv_sec; 
}

/****************************************************************************
 函数名称:dealPing
 函数功能:测试对应IP网络状况并将结果写入指定文件
 输入:
 _timeOutMsec           超时时间
 _ip                    需要检测的IP地址
 _packLen		单次发送包的大小

 输出:无
 返回值: 0:成功
 1:超时
2：网络不可达
 特殊说明:
 ****************************************************************************/
int dealPing(u32 _ip, u32 _packLen = 64, u32 _timeOutMsec = 400)
{
	int ret = 0,dwpid;
	int sockfd;
	struct sockaddr_in addrDest;
	float spenttime;
	u8 sSendPacket[MAXICMPLEN] = { 0 };
	struct in_addr tmpaddr;

	std::string ipString = "";
	char tmpIp[16] = { 0 };
	if (inet_ntop(AF_INET, &_ip, tmpIp, sizeof(tmpIp)))
		ipString = tmpIp;
	
	if (!_packLen || _packLen > 1472)
	{
		_packLen = 32;
	}
	if ((sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)
	{
		//LOG_ERROR("dealPing", "Create icmp socket fail");
		printf("dealPing , Create icmp socket fail");
		return sockfd;
	}

	addrDest.sin_addr.s_addr = _ip;
	addrDest.sin_family = AF_INET;
	bzero(&(addrDest.sin_zero), 8);
	bzero(&tmpaddr, sizeof(tmpaddr));

	ECHOREQUEST *pechoReq = (ECHOREQUEST *) sSendPacket;
	pechoReq->icmpHdr.Type = ICMP_ECHO;
	pechoReq->icmpHdr.Code = 0;
	pechoReq->icmpHdr.ID = getpid();
	dwpid = pechoReq->icmpHdr.ID;
	int Seq = 0;

	memset(pechoReq->cData, 0xa5, _packLen);

	/*addrDest.sin_addr.s_addr = _ip;
	addrDest.sin_family = AF_INET;
	bzero(&(addrDest.sin_zero), 8);*/

	pechoReq->icmpHdr.Seq = Seq++;
	pechoReq->icmpHdr.Checksum = 0;
	gettimeofday(&pechoReq->echoTime, NULL);
	pechoReq->icmpHdr.Checksum = checksum((unsigned short*) pechoReq, _packLen + sizeof(pechoReq->icmpHdr) + sizeof(pechoReq->echoTime));
	if ((ret = sendto(sockfd, sSendPacket, _packLen + sizeof(pechoReq->echoTime) + sizeof(pechoReq->icmpHdr), 0, (struct sockaddr *) &addrDest, sizeof(addrDest))) < 0)
	{
		//LOG_ERROR("dealPing", "sendto fail");
		//printf("dealPing , sendto fail\n");
		printf("dealPing , %s Destination Host Unreachable\n", ipString.c_str());
		close(sockfd);
		return ret;
	}

	ECHOREPLY icmpRecv;
	struct timeval Timeout;
	fd_set readfds;
	FD_ZERO(&readfds);
	FD_SET(sockfd, &readfds);
	//Timeout.tv_sec = _timeOutMsec / 1000;
	//Timeout.tv_usec = (_timeOutMsec % 1000) * 1000;
	Timeout.tv_sec = 1;
	Timeout.tv_usec = 0;
	ret = select(sockfd + 1, &readfds, NULL, NULL, &Timeout);
	if (ret > 0)
	{
		if (FD_ISSET(sockfd, &readfds) > 0)
		{
			socklen_t addr_len;
			addr_len = sizeof(struct sockaddr);
			memset(&icmpRecv, 0, sizeof(ECHOREPLY));
			if ((ret = recvfrom(sockfd, (ECHOREPLY*) &icmpRecv, sizeof(tagECHOREPLY), 0, (struct sockaddr *) &addrDest, &addr_len)) <= 0)
			{
				//LOG_ERROR("dealPing", "recvfrom error");
				printf("dealPing , recvfrom error\n");
				close(sockfd);
				return ret;
			}

			printf("Type:%d\n",icmpRecv.echoRequest.icmpHdr.Type);
			printf("ID:%d\n",icmpRecv.echoRequest.icmpHdr.ID);
			
			if (icmpRecv.echoRequest.icmpHdr.Type == ICMP_ECHOREPLY && (addrDest.sin_addr.s_addr == _ip) && (icmpRecv.echoRequest.icmpHdr.ID == dwpid))
			{
				gettimeofday(&icmpRecv.echoRequest.echoTime, NULL);
				tv_sub(&icmpRecv.echoRequest.echoTime, &pechoReq->echoTime);
				spenttime = icmpRecv.echoRequest.echoTime.tv_sec * 1000 + icmpRecv.echoRequest.echoTime.tv_usec * 0.001;
				if (spenttime <= (float)_timeOutMsec)
				{
					//LOG_DEBUG("dealPing", "Connect Normally Id_seq = %d time=%4.3fms\n", icmpRecv.echoRequest.icmpHdr.Seq, spenttime);
					printf("dealPing , Connect Normally Id_seq = %d time=%4.3fms\n", icmpRecv.echoRequest.icmpHdr.Seq, spenttime);
					return ret;
				}
				else
				{
					//LOG_DEBUG("dealPing", "Request %u Time out!\n", _ip);
					printf("dealPing , Request %s Time out!\n", ipString.c_str());
					return 1;
				}
			}
			else if ((icmpRecv.echoRequest.icmpHdr.Type == ICMP_ECHOREPLY) && (addrDest.sin_addr.s_addr != _ip) && (icmpRecv.echoRequest.icmpHdr.ID == dwpid))
			{
				//LOG_ERROR("dealPing", "%u Destination Host Unreachable\n", _ip);
				printf("dealPing , %s Destination Host Unreachable\n", ipString.c_str());
				return 1;
			}
		}
	}
	else
	{
		//LOG_ERROR("dealPing", "%u Destination Host Unreachable\n", _ip);
		printf("dealPing , %s Destination Host Unreachable\n", ipString.c_str());
		return 1;
	}

	close(sockfd);
	return ret;
}

int main()
{
	std::string _mIP = "192.168.10.91";
	u32 _ip = 0;
	inet_pton(AF_INET, _mIP.c_str(), (void *) &_ip);
	u32 _packLen = 64;
	u32 _timeOutMsec = 400;
	//printf("_ip:%d\n",_ip);
	//while(true)
	//{
		dealPing(_ip, _packLen, _timeOutMsec);
		//sleep(1);
	//}
	return 0;
}

为什么recvfrom的时候返回的icmpRecv.echoRequest.icmpHdr.Type是ICMP_ECHO而不是ICMP_ECHOREPLY求高手帮忙看下？谢谢了