发送arp请求报文

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/ethernet.h>
#include <netpacket/packet.h>
#include <string.h>
#include <net/if.h>
 
#define SRC_MAC  { 0x00,0x0C,0x29,0x6F,0x57,0xE7 }//源MAC地址
#define DEST_MAC { 0x00,0x0C,0x29,0xD3,0xD6,0xF7 }//目的MAC地址
 
struct arppacket
{
	unsigned char dest_mac[ETH_ALEN];//接收方MAC
	unsigned char src_mac[ETH_ALEN];//发送方MAC
	unsigned short type;       //0x0806是ARP帧的类型值
	unsigned short ar_hrd;//硬件类型 - 以太网类型值0x1
	unsigned short ar_pro;//上层协议类型 - IP协议(0x0800)
	unsigned char  ar_hln;//MAC地址长度
	unsigned char  ar_pln;//IP地址长度
	unsigned short ar_op;//操作码 - 0x1表示ARP请求包,0x2表示应答包
	unsigned char  ar_sha[ETH_ALEN];//发送方mac
	unsigned char ar_sip[4];//发送方ip
	unsigned char ar_tha[ETH_ALEN];//接收方mac
	unsigned char ar_tip[4];//接收方ip
} __attribute__ ((__packed__));

int main(int argc,char *argv[])
{
	int fd = 0;
	struct in_addr s,r;
	struct sockaddr_ll sl;
 
	struct arppacket arp={
		DEST_MAC,
		SRC_MAC,
		htons(0x0806),
		htons(0x01),
		htons(0x0800),
		ETH_ALEN,
		4,
		htons(0x01),
		SRC_MAC,
		{0},
		DEST_MAC,
		{0}
	};
 
	fd = socket(AF_PACKET,SOCK_RAW,htons(ETH_P_ALL));
	if (fd < 0) {
		printf("socket error\n");
		return -1;
	}
	memset(&sl, 0, sizeof(sl));
 
	inet_aton("192.168.11.220", &s);
	memcpy(&arp.ar_sip, &s, sizeof(s));
 
	inet_aton("192.168.11.192", &r);
	memcpy(&arp.ar_tip, &r, sizeof(r));
 
 
	sl.sll_family = AF_PACKET;
	sl.sll_ifindex = IFF_BROADCAST;
	
	while (1) {
		if (sendto(fd, &arp, sizeof(arp), 0, (struct sockaddr*)&sl, sizeof(sl)) <= 0)
			printf("send error\n");
		else
			printf("send success\n");
 
		sleep(1);
	}
 
	close(fd);
 
	return 0;
}