我用C++，icmp制作了Ping程序.但它不适用于安卓

这是ping代码。在select函数之后，retval 仅为 0。我检查了这在 mac OS 上运行良好。我检查了很多IP。但它不仅适用于安卓设备。我不知道是什么问题。我第一次使用 SOCK_RAW 制作了套接字，但它仅适用于超级用户。所以我SOCK_DGRAM改了。它适用于普通用户的 Mac OS。和它有关吗？

int ping(string target)
{
int s, i, cc, packlen, datalen = DEFDATALEN;
struct hostent *hp;
struct sockaddr_in to, from;
struct ip *ip;
u_char *packet, outpack[MAXPACKET];
char hnamebuf[MAXHOSTNAMELEN];
string hostname;
struct icmp *icp;
int ret, fromlen, hlen;
fd_set rfds;
struct timeval tv;
int retval;
struct timeval start, end;
int end_t;
bool cont = true;
to.sin_family = AF_INET;
to.sin_addr.s_addr = htonl(inet_addr(target.c_str()));
//to.sin_port = 0;
if (to.sin_addr.s_addr != (u_int)-1)
{
hostname = target;
pErrorLabel->setString(hostname);
}
else
{
hp = gethostbyname(target.c_str());
if (!hp)
{
pErrorLabel->setString("Unknown host");
cerr << "unknown host " << target << endl;
return -1;
}
to.sin_family = hp->h_addrtype;
bcopy(hp->h_addr, (caddr_t)&to.sin_addr, hp->h_length);
strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
hostname = hnamebuf;
}
packlen = datalen + MAXIPLEN + MAXICMPLEN;
if ((packet = (u_char *)malloc((u_int)packlen)) == NULL)
{
pErrorLabel->setString("malloc error");
cerr << "malloc errorn";
return -1;
}

if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP)) < 0)
{
pErrorLabel->setString("administrator");
return -1; /* Needs to run as superuser!! */
}
icp = (struct icmp *)outpack;
icp->icmp_type = ICMP_ECHO;
icp->icmp_code = 0;
icp->icmp_cksum = 0;
icp->icmp_seq = 12345;
icp->icmp_id = getpid();
cc = datalen + ICMP_MINLEN;
icp->icmp_cksum = in_cksum((unsigned short *)icp, cc);
gettimeofday(&start, NULL);
i = sendto(s, (char *)outpack, cc, 0, (struct sockaddr*)&to, (socklen_t)sizeof(struct sockaddr_in));
if (i < 0 || i != cc)
{
if (i < 0)
perror("sendto error");
cout << "wrote " << hostname << " " << cc << " chars, ret= " << i << endl;
}
FD_ZERO(&rfds);
FD_SET(s, &rfds);
tv.tv_sec = 5;
tv.tv_usec = 0;
std::stringstream ss;
ss << "socket=" << (int)s;
pErrorLabel->setString(ss.str().c_str());
while (cont)
{
retval = select(s + 1, &rfds, NULL, NULL, &tv);
if (retval == -1)
{
perror("select()");
pErrorLabel->setString("select()");
return -1;
}
else if (retval)
{
fromlen = sizeof(sockaddr_in);
if ((ret = recvfrom(s, (char *)packet, packlen, 0, (struct sockaddr *)&from, (socklen_t*)&fromlen)) < 0)
{
perror("recvfrom error");
pErrorLabel->setString("recvfrom error");
return -1;
}
// Check the IP header
ip = (struct ip *)((char*)packet);
hlen = sizeof(struct ip);
if (ret < (hlen + ICMP_MINLEN))
{
cerr << "packet too short (" << ret << " bytes) from " << hostname << endl;;
return -1;
}
// Now the ICMP part 
icp = (struct icmp *)(packet + hlen);
if (icp->icmp_type == ICMP_ECHOREPLY)
{
if (icp->icmp_seq != 12345)
{
cout << "received sequence # " << icp->icmp_seq << endl;
continue;
}
if (icp->icmp_id != getpid())
{
cout << "received id " << icp->icmp_id << endl;
continue;
}
cont = false;
}
else
{

continue;
}
gettimeofday(&end, NULL);
end_t = 1000000 * (end.tv_sec - start.tv_sec) + (end.tv_usec - start.tv_usec);
if (end_t < 1)
end_t = 1;
cout << "Elapsed time = " << end_t << " usec" << endl;
return end_t;
}
else
{
cout << "No data within one seconds.n";
return 0;
}
}
return 0;
}