android NDK 获取本机IP

int i=0;
int sockfd;
struct ifconf ifconf;
unsigned char buf[512];
struct ifreq *ifreq;
//初始化ifconf
ifconf.ifc_len = 512;
ifconf.ifc_buf = (char*)buf;
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0))<0)
{
return -1;
}
ioctl(sockfd, SIOCGIFCONF, &ifconf); //获取所有接口信息
//接下来一个一个的获取IP地址
ifreq = (struct ifreq*)buf;

for (i=(ifconf.ifc_len/sizeof (struct ifreq)); i>0; i--)
{
// if(ifreq->ifr_flags == AF_INET){ //for ipv4
char* ip = inet_ntoa(((struct sockaddr_in*)&(ifreq->ifr_addr))->sin_addr);
__android_log_print(ANDROID_LOG_INFO,"test","%s",ip);
ifreq++;
// }
}