socket发送arp的工具

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <sys/socket.h>
#include <sys/ioctl.h>
#include <arpa/inet.h>

#include <linux/if.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>

#define IPV4_LENGTH 4
#define buffer_len 60   //ARP请求包大小为60B,,抓包时会抓到一些42B的包，这是抓包软件没有显示18B的Padding字段，Padding全0填充在包的末尾
/*ARP包结构*/
/*字段顺序不可更改，发包时是直接将buffer发出*/
struct arp_head{
   
    uint16_t hardware_type;   //硬件类型#1:Ethernet
	uint16_t protocol_type;   //协议类型#0x0800:IPv4
    uint8_t hardware_size;    //MAC地址长度#6
    uint8_t protocol_size;    //IP地址长度#4
    uint16_t opcode;          //ARP类型#1:request;2:reply
    uint8_t sender_mac[ETH_ALEN];    //源MAC地址
    uint8_t sender_ip[IPV4_LENGTH];  //源IP地址
    uint8_t target_mac[ETH_ALEN];    //目标MAC地址
    uint8_t target_ip[IPV4_LENGTH];  //目标IP地址
};

static void show_manual(int argc,char const *argv[]);
static int ip4str_parse(const char *point, unsigned char result[4]);
static int macstr_parse(const char *point, unsigned char result[6]);
static int parse_arg(int argc,char const *argv[],char *dev_name,uint8_t *dest_mac_addr,uint8_t *sender_ip,uint8_t *target_ip);
/******************************************************************************************/
int main(int argc, char const *argv[])
{
   
    int i;
    char dev_name[0x10];
    uint8_t dest_mac_addr[6];
    uint8_t sender_ip[4];    //ARP请求的源IP
    uint8_t target_ip[4];     //ARP请求的目标IP

    if(parse_arg(argc,argv,dev_name,dest_mac_addr,sender_ip,target_ip)){
   
        show_manual(argc,argv);
        exit