1.RawSocket简介
RawSocket是数据链路层的socket
Raw socket(原始套接字)是一种特殊的网络套接字类型,它允许应用程序直接发送和接收底层的网络数据包,而不需要经过标准的传输层协议(如TCP或UDP)的处理。以下是raw socket的一些关键特点:
- 直接访问网络层 :
- Raw socket允许应用程序直接与网络层交互,发送和接收IP数据包。这意味着应用程序可以绕过传输层协议,直接处理网络数据。
2.灵活性 :
- 由于raw socket提供了对网络数据包的直接控制,它为网络编程提供了极大的灵活性。应用程序可以自定义数据包的内容和格式,实现特定的网络功能。
3.低级访问 :
- Raw socket提供了对网络协议栈的低级访问。应用程序可以访问和修改IP头、TCP头、UDP头等网络协议头部,实现复杂的网络操作。
4.安全性 :
- Raw socket的使用需要较高的权限,通常只有具有管理员权限的用户才能创建raw socket。这是因为raw socket可以发送任意类型的网络数据包,可能会被用于恶意目的。
5.应用场景 :
- Raw socket常用于网络工具和诊断工具的开发,如网络嗅探器、防火墙、入侵检测系统等。它们需要直接访问网络数据包来实现特定的功能。
6.编程复杂性 :
- 由于raw socket提供了底层的网络访问,使用raw socket进行网络编程通常比使用标准的套接字更加复杂。开发者需要对网络协议有深入的理解。
7.操作系统支持 :
- 不同的操作系统对raw socket的支持程度不同。大多数Unix-like系统(如Linux和macOS)支持raw socket,但可能需要特定的权限或配置
2.raw socket收发底层网络数据包
2.1 创建raw socket
创建一个raw socket:
int sock = socket(PF_PACKET,SOCK_RAW,htons(ETH_P_ALL));
if(sock < 0)
{
perror("sock");
return -1;
}
在Linux系统中,使用 socket
函数创建原始套接字(raw socket)时,可以捕获和发送任意类型的网络数据包。以下是 socket
函数调用 socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
中各个参数的说明:
1.PF_PACKET :
PF_PACKET
(Packet Family)是一个常量,表示要创建的套接字用于处理原始数据包。这个参数指定了套接字的地址族,告诉内核这个套接字将用于处理低级的数据包。
2.SOCK_RAW :
SOCK_RAW
是一个常量,表示套接字类型为原始套接字。这种类型的套接字允许应用程序直接发送和接收原始的网络数据包,绕过标准的传输层协议(如TCP或UDP)。
3.htons(ETH_P_ALL) :
htons
是“host to network short”的缩写,是一个函数,用于将16位的主机字节顺序值转换为网络字节顺序。这对于网络通信是必要的,因为网络协议要求使用大端字节顺序。ETH_P_ALL
是一个宏,定义了以太网协议类型,其值是0x0003。使用htons(ETH_P_ALL)
表示这个原始套接字将捕获所有类型的以太网数据包,无论它们的协议类型是什么。
此外还有以下宏定义:
ETH_P_IP:表示 IPv4 协议,即以太网帧包含一个 IP 数据包。
ETH_P_ARP:表示 ARP(地址解析协议)数据包,用于将网络层的 IP 地址解析为链路层的 MAC 地址。
ETH_P_RARP:表示 RARP(反向地址解析协议),用于将链路层的 MAC 地址解析为网络层的 IP 地址。这个协议现在已经很少使用,被 DHCP 所取代。
ETH_P_IPV6:表示 IPv6 协议,即以太网帧包含一个 IPv6 数据包。
ETH_P_8021Q:表示 802.1Q VLAN(虚拟局域网)标记的以太网帧。
ETH_P_PPP_DISC:表示 PPPoE(以太网上的 PPP)发现阶段的数据包。
ETH_P_PPP_SES:表示 PPPoE 会话阶段的数据包。
ETH_P_MPLS_UC:表示 MPLS(多协议标签交换)单播数据包。
ETH_P_MPLS_MC:表示 MPLS 多播数据包。
ETH_P_802_3:表示标准的以太网帧,不包含任何额外的协议信息。
2.2 发送数据包
2.2.1 发送数据包函数原型
int sendto(int s,const void *buf,int len,unsigned int flags,
const struct sockaddr *to,int tolen);
2.2.2 返回值
成功则返回实际传送出去的字符数,失败返回-1,错误原因会存在于errno中
2.2.3 参数说明
s:socket描述符;
buf:rawsocket数据包缓存区(包含待发送数据)
len:rawsocket数据包的长度
flags:调用方式标志位(一般设置为0)
to:指向接收数据的主机地址信息的结构体(sockaddr_in需要进行类型转换)
tolen: to所指结构体的长度
2.2.4 使用方法
struct sockaddr_ll sll;
memset(&sll,0,sizeof(sll));
sll.sll_ifindex = 2; // 指定网卡
if(sendto(sock,packet_start,sizeof(packet_start),0,&sll,sizeof(sll)) < 0)
{
perror("sendto");
return 1;
}
sendto发送原始数据包,只需用struct sockaddr_ll的sll_ifindex指定网卡。
2.2.5 代码实例
发送raw socket(rawsocket_send.c):
#include <sys/socket.h>
#include <string.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <features.h> /* for the glibc version number */
#include <asm/types.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h> /* The L2 protocols */
#include <stdio.h>
#include <netinet/in.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <errno.h>
#define _PATH_PROCNET_DEV "/proc/net/dev"
static char *get_name(char *name, char *p)
{
while (isspace(*p))
p++;
while (*p) {
if (isspace(*p))
break;
if (*p == ':') { /* could be an alias */
char *dot = p, *dotname = name;
*name++ = *p++;
while (isdigit(*p))
*name++ = *p++;
if (*p != ':') { /* it wasn't, backup */
p = dot;
name = dotname;
}
if (*p == '\0')
return NULL;
p++;
break;
}
*name++ = *p++;
}
*name++ = '\0';
return p;
}
/**
* read_netdev_proc - read net dev names form proc/net/dev
* @devname: where to store dev names, devname[num][len]
*/
static int read_netdev_proc(void *devname, const int num, const int len)
{
FILE *fh;
char buf[512];
int cnt = 0;
char *dev = (char *)devname;
if(devname == NULL || num < 1 || len < 4){
printf("read_netdev_proc: para error\n");
return -1;
}
memset(devname, 0, len * num);
fh = fopen(_PATH_PROCNET_DEV, "r");
if (!fh) {
fprintf(stderr, "Warning: cannot open %s (%s). Limited output.\n",
_PATH_PROCNET_DEV, strerror(errno));
return -1;
}
fgets(buf, sizeof buf, fh); /* eat two line */
fgets(buf, sizeof buf, fh);
cnt = 0;
while (fgets(buf, sizeof buf, fh) && cnt < num) {
char *s, name[IFNAMSIZ];
s = get_name(name, buf);
strncpy(devname, name, len);
devname += len;
printf("get_name: %s\n", name);
}
if (ferror(fh)) {
perror(_PATH_PROCNET_DEV);
}
fclose(fh);
return 0;
}
/**
* get_hwaddr - get netdevice mac addr
* @name: device name, e.g: eth0
* @hwaddr: where to save mac, 6 byte hwaddr[6]
* @return: 0 on success, -1 on failure
*/
int get_hwaddr(char *name, unsigned char *hwaddr)
{
struct ifreq ifr;
unsigned char memzero[6];
int sock;
if(name == NULL || hwaddr == NULL){
printf("get_hwaddr: NULL para\n");
return -1;
}
sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock < 0){
printf("get_hwaddr: socket error\n");
//return -1;
}
//get eth1 mac addr
memset(hwaddr, 0, 6);
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, name, 6);
if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0){
perror("get_hwaddr ioctl:");
close(sock);
return -1;
} else {
memcpy(hwaddr, ifr.ifr_hwaddr.sa_data, 6);
//printf("hwaddr: %2x : %2x : %2x : %2x : %2x : %2x\n", hwaddr[0], hwaddr[1],hwaddr[2], hwaddr[3],hwaddr[4], hwaddr[5]);
}
memset(memzero, 0, 6);
if(memcmp(memzero, hwaddr, 6) == 0){
printf("no mac\n");
return -1;
}
close(sock);
return 0;
}
unsigned char packet_start[]={
0xff, 0xff, 0xff, 0xff, 0xff, 0xff,//dst mac
0x00, 0x23, 0x54, 0x0e, 0xe5, 0xd8,//src mac
0x88, 0x8e, //Type: 802.1x authentication
0x01, //Version:v1
0x01, //Type: Start (1)
0x00, 0x00//Length 0
};
void printhex(void *hex, int len, char *tag)
{
int i;
unsigned char *p = (unsigned char *)hex;
if(len < 1)
return;
for(i = 0; i < len - 1; i++){
if(*p < 0x10)
printf("0%x%s", *p++, tag);
else
printf("%2x%s", *p++, tag);
}
if(*p < 0x10)
printf("0%x\n", *p++);
else
printf("%2x\n", *p++);
}
int main(int argc, char **argv)
{
int i;
unsigned char hwaddr[6];
char devname[3][7];
unsigned char buf[1024]; // for revevied packet
int ret;
read_netdev_proc(devname, 3, 7);
for(i = 0; i < 3 && get_hwaddr(devname[i], hwaddr) != 0; i++){
//empty
}
printf("devname: [ %s ]\t", devname[i]);
printhex(hwaddr, 6, ":");
int sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if(sock < 0){
perror("sock");
return -1;
}
struct sockaddr_ll sll;
memset(&sll, 0, sizeof(sll));
sll.sll_ifindex = 2; // It seems only need this to specify whiAWSch NIC to use
memcpy(packet_start + 6, hwaddr, 6);
while(1){
if (sendto(sock, packet_start, sizeof packet_start, 0, &sll, sizeof(sll)) < 0){
perror("sendto");
return 1;
}
printf("Sendto Success!\n");
sleep(1);
}
return 0;
}
2.3 接收数据包
2.3.1 接收数据包函数原型
int recvfrom(int s,void *buf,int len,unsigned int flags,
struct sockaddr *from,int *fromlen)
2.3.2 返回值
成功则返回实际接收到的字符数,失败返回-1,错误原因存于errno中。
2.3.3 参数说明
s: socket描述符
buf: rawsocket数据报缓存区(包含所接收的数据)
len: 缓冲区长度
flags: 调用操作方式(一般设置为0)
from:指向发送数据的客户端地址信息的结构体(sockaddr_in需类型和转换)
fromlen:指针,指向from结构体长度值
2.3.4 使用方法
ret = recvfrom(sock,buf,1024,0,NULL,NULL);
2.3.5 代码示例
接收raw socket(rawsocket_recv.c):
#include <sys/socket.h>
#include <string.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <features.h> /* for the glibc version number */
#include <asm/types.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h> /* The L2 protocols */
#include <stdio.h>
#include <netinet/in.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <errno.h>
void printhex(void *hex, int len, char *tag)
{
int i;
unsigned char *p = (unsigned char *)hex;
if(len < 1)
return;
for(i = 0; i < len - 1; i++){
if(*p < 0x10)
printf("0%x%s", *p++, tag);
else
printf("%2x%s", *p++, tag);
}
if(*p < 0x10)
printf("0%x\n", *p++);
else
printf("%2x\n", *p++);
}
int main(int argc, char **argv)
{
int i;
unsigned char hwaddr[6];
char devname[3][7];
unsigned char buf[1024]; // for revevied packet
int ret;
int sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if(sock < 0){
perror("sock");
return -1;
}
while(1){
ret = recvfrom(sock, buf, 1024, 0, NULL, NULL);
printf("recv: ");
printhex(buf, ret, " ");
}
return 0;
}
将以上两份代码编译生成两个可执行程序:
gcc rawsocket_send.c -o rawsocket_send
gcc rawsocket_recv.c -o rawsocket_recv
手动执行收发程序:
sudo ./rawsocket_send
sudo ./rawsocket_recv
2.4 收发实例运行
发送端
接收端
wireshark抓取报文
3.rawSocket进行文件收发
3.1 rawSocket发送指定路径的文件
rawsocket.h
#ifndef _RAWSOCKET_H_
#define _RAWSOCKET_H_
//#include <sys/socket.h>
#include <string.h>
#include <sys/types.h>
//#include <arpa/inet.h>
#include <features.h> /* for the glibc version number */
#include <asm/types.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h> /* The L2 protocols */
#include <stdio.h>
//#include <netinet/in.h>
//#include <net/if.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <stdlib.h>
#include <signal.h>
#include <linux/if_packet.h>
#include <linux/if.h>
#define SRCMAC_LEN 6
#define DSTMAC_LEN 6
#define PROTOTYPE_LEN 2
unsigned char packet_start[]={
0xff, 0xff, 0xff, 0xff, 0xff, 0xff,//dst mac
0x00, 0x23, 0x54, 0x0e, 0xe5, 0xd8,//src mac
0x88, 0x8e, //Type: 802.1x authentication
0x01, //Version:v1
0x01, //Type: Start (1)
0x00, 0x00//Length 0
};
unsigned char packet_type[]={
0x08,0x06, //Type: 802.1x authentication
};
#endif
rawsocket_sendfile.c
#include "rawsocket.h"
#define _PATH_PROCNET_DEV "/proc/net/dev"
static char *get_name(char *name, char *p)
{
while (isspace(*p))
p++;
while (*p) {
if (isspace(*p))
break;
if (*p == ':') { /* could be an alias */
char *dot = p, *dotname = name;
*name++ = *p++;
while (isdigit(*p))
*name++ = *p++;
if (*p != ':') { /* it wasn't, backup */
p = dot;
name = dotname;
}
if (*p == '\0')
return NULL;
p++;
break;
}
*name++ = *p++;
}
*name++ = '\0';
return p;
}
/**
* read_netdev_proc - read net dev names form proc/net/dev
* @devname: where to store dev names, devname[num][len]
*/
static int read_netdev_proc(void *devname, const int num, const int len)
{
FILE *fh;
char buf[512];
int cnt = 0;
char *dev = (char *)devname;
if(devname == NULL || num < 1 || len < 4){
printf("read_netdev_proc: para error\n");
return -1;
}
memset(devname, 0, len * num);
fh = fopen(_PATH_PROCNET_DEV, "r");
if (!fh) {
fprintf(stderr, "Warning: cannot open %s (%s). Limited output.\n",
_PATH_PROCNET_DEV, strerror(errno));
return -1;
}
fgets(buf, sizeof buf, fh); /* eat two line */
fgets(buf, sizeof buf, fh);
cnt = 0;
while (fgets(buf, sizeof buf, fh) && cnt < num) {
char *s, name[IFNAMSIZ];
s = get_name(name, buf);
strncpy(devname, name, len);
devname += len;
printf("get_name: %s\n", name);
}
if (ferror(fh)) {
perror(_PATH_PROCNET_DEV);
}
fclose(fh);
return 0;
}
/**
* get_hwaddr - get netdevice mac addr
* @name: device name, e.g: eth0
* @hwaddr: where to save mac, 6 byte hwaddr[6]
* @return: 0 on success, -1 on failure
*/
int get_hwaddr(char *name, unsigned char *hwaddr)
{
struct ifreq ifr;
unsigned char memzero[6];
int sock;
if(name == NULL || hwaddr == NULL){
printf("get_hwaddr: NULL para\n");
return -1;
}
sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock < 0){
printf("get_hwaddr: socket error\n");
//return -1;
}
//get eth1 mac addr
memset(hwaddr, 0, 6);
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, name, 6);
if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0){
perror("get_hwaddr ioctl:");
close(sock);
return -1;
} else {
memcpy(hwaddr, ifr.ifr_hwaddr.sa_data, 6);
//printf("hwaddr: %2x : %2x : %2x : %2x : %2x : %2x\n", hwaddr[0], hwaddr[1],hwaddr[2], hwaddr[3],hwaddr[4], hwaddr[5]);
}
memset(memzero, 0, 6);
if(memcmp(memzero, hwaddr, 6) == 0){
printf("no mac\n");
return -1;
}
close(sock);
return 0;
}
void printhex(void *hex, int len, char *tag)
{
int i;
unsigned char *p = (unsigned char *)hex;
if(len < 1)
return;
for(i = 0; i < len - 1; i++){
if(*p < 0x10)
printf("0%x%s", *p++, tag);
else
printf("%2x%s", *p++, tag);
}
if(*p < 0x10)
printf("0%x\n", *p++);
else
printf("%2x\n", *p++);
}
int main()
{
int i;
unsigned char hwaddr[SRCMAC_LEN];
unsigned char hwaddr_dst[DSTMAC_LEN] = {0x54,0x6C,0xEB,0x2D,0x3D,0xC2};
char devname[3][7];
int ret;
read_netdev_proc(devname, 3, 7);
for(i = 0; i < 3 && get_hwaddr(devname[i], hwaddr) != 0; i++){
//empty
}
printf("devname: [ %s ]\t", devname[i]);
printhex(hwaddr, 6, ":");
#if 0
int sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if(sock < 0){
perror("sock");
return -1;
}
struct sockaddr_ll sll;
memset(&sll, 0, sizeof(sll));
sll.sll_ifindex = 2; // It seems only need this to specify whiAWSch NIC to use
#else
struct sockaddr_ll sll;
memset(&sll,0,sizeof(sll));
sll.sll_family = AF_PACKET;//填写AF_PACKET,不再经协议层处理
sll.sll_protocol = htons(ETH_P_ALL);
#if 0
struct ifreq req;
int sd;
sd = socket(PF_INET,SOCK_DGRAM,0); //这个sd就是用来获取eth0的index,完了就关闭
strncpy(req.ifr_name,"enp0s3",4); //通过设备名称获取index
ret=ioctl(sd,SIOCGIFINDEX,&req);
close(sd);
if (ret==-1)
{
printf("Level:%d [Searcher main]Get eth0 index err \n", ret);
}
#endif
sll.sll_ifindex = 2; //网卡eth0的index,非常重要,系统把数据往哪张网卡上发,就靠这个标识
sll.sll_pkttype = PACKET_OUTGOING; //标识包的类型为发出去的包
// 以下配置非必须
sll.sll_halen = DSTMAC_LEN; //目标MAC地址长度为6
//填写目标MAC地址
sll.sll_addr[0] = 0x54;
sll.sll_addr[1] = 0x6C;
sll.sll_addr[2] = 0xEB;
sll.sll_addr[3] = 0x2D;
sll.sll_addr[4] = 0x3D;
sll.sll_addr[5] = 0xC2;
#endif
long bufSize = 0;
FILE* readfile = fopen("/home/user/Desktop/codes/my_em/my-embedded/app/NET/RawSocket/filename.txt","rb");
if(!readfile)
{
perror("file open failed:\n");
return -1;
}
// get file size
fseek(readfile,0,SEEK_END); // 将文件位置指针移动到最后
bufSize = ftell(readfile); // ftell(FILE *stream):返回给定流stream的当前文件位置,获取当前位置相对文件首的位移,位移值等于文件所含字节数
fseek(readfile,0,SEEK_SET); // 将文件位置指针移动到开头
printf("filesize:%ld\n",bufSize);
// unsigned char buffer[1024] = {0};
unsigned char *buffer = (unsigned char*)malloc(sizeof(unsigned char)*bufSize+8);
if(!buffer)
{
return -1;
}
// dst mac:6 src mac:6
memcpy(buffer,hwaddr_dst,DSTMAC_LEN); // dst mac
memcpy(buffer+DSTMAC_LEN,hwaddr,SRCMAC_LEN); // src mac
memcpy(buffer+DSTMAC_LEN+SRCMAC_LEN,packet_type,PROTOTYPE_LEN); // proto type
int sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if(sock < 0){
perror("sock");
return -1;
}
int nCount;
while((nCount = fread(&buffer[DSTMAC_LEN+SRCMAC_LEN+PROTOTYPE_LEN],1,bufSize,readfile)) > 0)
{
if (sendto(sock, buffer, sizeof(unsigned char)*bufSize+8, 0, &sll, sizeof(sll)) < 0){
perror("sendto");
return 1;
}
printf("Sendto Success!\n");
}
free(buffer);
return 0;
}
wireshark抓取报文情况:
3.2 rawSocket接收文件后存储到指定路径
rawsocket_recvfile.c
#include "rawsocket.h"
#define _PATH_PROCNET_DEV "/proc/net/dev"
static char *get_name(char *name, char *p)
{
while (isspace(*p))
p++;
while (*p) {
if (isspace(*p))
break;
if (*p == ':') { /* could be an alias */
char *dot = p, *dotname = name;
*name++ = *p++;
while (isdigit(*p))
*name++ = *p++;
if (*p != ':') { /* it wasn't, backup */
p = dot;
name = dotname;
}
if (*p == '\0')
return NULL;
p++;
break;
}
*name++ = *p++;
}
*name++ = '\0';
return p;
}
/**
* read_netdev_proc - read net dev names form proc/net/dev
* @devname: where to store dev names, devname[num][len]
*/
static int read_netdev_proc(void *devname, const int num, const int len)
{
FILE *fh;
char buf[512];
int cnt = 0;
char *dev = (char *)devname;
if(devname == NULL || num < 1 || len < 4){
printf("read_netdev_proc: para error\n");
return -1;
}
memset(devname, 0, len * num);
fh = fopen(_PATH_PROCNET_DEV, "r");
if (!fh) {
fprintf(stderr, "Warning: cannot open %s (%s). Limited output.\n",
_PATH_PROCNET_DEV, strerror(errno));
return -1;
}
fgets(buf, sizeof buf, fh); /* eat two line */
fgets(buf, sizeof buf, fh);
cnt = 0;
while (fgets(buf, sizeof buf, fh) && cnt < num) {
char *s, name[IFNAMSIZ];
s = get_name(name, buf);
strncpy(devname, name, len);
devname += len;
printf("get_name: %s\n", name);
}
if (ferror(fh)) {
perror(_PATH_PROCNET_DEV);
}
fclose(fh);
return 0;
}
/**
* get_hwaddr - get netdevice mac addr
* @name: device name, e.g: eth0
* @hwaddr: where to save mac, 6 byte hwaddr[6]
* @return: 0 on success, -1 on failure
*/
int get_hwaddr(char *name, unsigned char *hwaddr)
{
struct ifreq ifr;
unsigned char memzero[6];
int sock;
if(name == NULL || hwaddr == NULL){
printf("get_hwaddr: NULL para\n");
return -1;
}
sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock < 0){
printf("get_hwaddr: socket error\n");
//return -1;
}
//get eth1 mac addr
memset(hwaddr, 0, 6);
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, name, 6);
if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0){
perror("get_hwaddr ioctl:");
close(sock);
return -1;
} else {
memcpy(hwaddr, ifr.ifr_hwaddr.sa_data, 6);
//printf("hwaddr: %2x : %2x : %2x : %2x : %2x : %2x\n", hwaddr[0], hwaddr[1],hwaddr[2], hwaddr[3],hwaddr[4], hwaddr[5]);
}
memset(memzero, 0, 6);
if(memcmp(memzero, hwaddr, 6) == 0){
printf("no mac\n");
return -1;
}
close(sock);
return 0;
}
void printhex(void *hex, int len, char *tag)
{
int i;
unsigned char *p = (unsigned char *)hex;
if(len < 1)
return;
for(i = 0; i < len - 1; i++){
if(*p < 0x10)
printf("0%x%s", *p++, tag);
else
printf("%2x%s", *p++, tag);
}
if(*p < 0x10)
printf("0%x\n", *p++);
else
printf("%2x\n", *p++);
}
int main()
{
int i;
unsigned char hwaddr[6];
char devname[3][7];
unsigned char buf[1024]; // for revevied packet
const char *fileName = "abc.bin";
int ret = 0;
read_netdev_proc(devname, 3, 7);
for(i = 0; i < 3 && get_hwaddr(devname[i], hwaddr) != 0; i++){
//empty
}
printf("devname: [ %s ]\t", devname[i]);
printhex(hwaddr, 6, ":");
int sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if(sock < 0){
perror("sock");
return -1;
}
#if 1
unsigned char packet_type[] = {0x08,0x06};
int nCount;
while(1){
memset(buf,0,1024);
while((nCount = recvfrom(sock,buf,1024,0,NULL,NULL)) > 0)
{
printf("nCount:%d\n",nCount);
if(0 == memcmp(packet_type,&buf[12],2))
{
FILE* write = fopen(fileName,"a+");
if(!write)
{
perror("file write failed:\n");
return -1;
}
printf("same recv: ");
printhex(&buf[14], nCount-12, " ");
// len要-12去6个字节的srcmac和6个字节的dstmac
ret += fwrite(&buf[14],nCount-12,1,write);
// printf("receive file success!\n");
fclose(write);
}
}
}
#else
while(1){
ret = recvfrom(sock, buf, 1024, 0, NULL, NULL);
printf("recv: ");
printhex(buf, ret, " ");
}
#endif
return 0;
}
接收存储文件的内容:
参考文章:
读取linux下的网络设备的mac地址与发送原始数据包_linux检查报文源mac-CSDN博客
UDP协议 sendto 和 recvfrom 浅析与示例 - 阳光长脸兽 - 博客园 (cnblogs.com
(十三)Packet socket 和 sockaddr_ll - xtusir - 博客园 (cnblogs.com)
标签:return,name,int,什么,char,++,RawSocket,hwaddr From: https://www.cnblogs.com/Wangzx000/p/16595657.html