通过arp实现输入ip地址输出mac地址

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <netinet/if_ether.h>
#include <sys/ioctl.h>
#include <net/if_arp.h>

struct arpreq arpreq;
int main(int argc, char* argv[])
{

if(argc < 2)
{
printf("Usage: %s IP\n",argv[0]);
return 0;
}
int sd;
struct arpreq arpreq;
struct sockaddr_in *sin;
struct in_addr ina;
unsigned char *hw_addr;
sd = socket(AF_INET, SOCK_DGRAM, 0);
if (sd < 0)
{
perror("socket() error\n");
exit(1);
}
printf("IP : %s\n", argv[1]);
memset(&arpreq, 0, sizeof(struct arpreq));
sin = (struct sockaddr_in *) &arpreq.arp_pa;
memset(sin, 0, sizeof(struct sockaddr_in));
sin->sin_family = AF_INET;
ina.s_addr = inet_addr(argv[1]);
memcpy(&sin->sin_addr, (char *)&ina, sizeof(struct in_addr));
strcpy(arpreq.arp_dev, "wl0.1"); //wifi热点所用的网卡为wl0.1
ioctl(sd, SIOCGARP, &arpreq);
printf("\nentry has been successfully retreived\n");
hw_addr = (unsigned char *) arpreq.arp_ha.sa_data;
printf("MAC: %x:%x:%x:%x:%x:%x\n",
hw_addr[0], hw_addr[1], hw_addr[2], hw_addr[3], hw_addr[4], hw_addr[5]);
return 0;
}

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)

LOCAL_ARM_MODE := arm

LOCAL_SRC_FILES := \
ipmac.c

LOCAL_MODULE:= ipmac

LOCAL_PRELINK_MODULE := false

LOCAL_C_INCLUDES += \
$(LOCAL_PATH)/include

include $(BUILD_EXECUTABLE) //编译成可执行文件