// arp协议
// 以太网头部 || ARP请求/应答
// 目的mac地址 | 源mac地址 | 帧类型 || 硬件类型 | 协议类型 | 硬件地址长度 | 协议地址长度 | 操作方式 | 发送方硬件地址 | 发送方IP地址 | 接收方硬件地址 | 接收方IP地址 |
// 6byte | 6byte | 2byte || 2byte | 2byte | 1byte | 1byte | 2byte | 6byte | 4byte | 6byte | 4byte |
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/if.h>
#include <sys/types.h>
#include <asm/types.h>
#include <features.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <netinet/if_ether.h>
#include <arpa/inet.h>// arp协议
// 以太网头部 || ARP请求/应答
// 目的mac地址 | 源mac地址 | 帧类型 || 硬件类型 | 协议类型 | 硬件地址长度 | 协议地址长度 | 操作方式 | 发送方硬件地址 | 发送方IP地址 | 接收方硬件地址 | 接收方IP地址 |
// 6byte | 6byte | 2byte || 2byte | 2byte | 1byte | 1byte | 2byte | 6byte | 4byte | 6byte | 4byte |typedef struct
{/* 以太网头部 */unsigned char nDstMac[6]; /* 目的mac地址 */unsigned char nSrcMac[6]; /* 源mac地址 */unsigned short nProto; /* 帧类型 *//* ARP请求/应答 */unsigned short hardwareType; /* 硬件类型 */unsigned short protoType; /* 协议类型 */unsigned char hardwareLen; /* 硬件地址长度 */unsigned char protoLen; /* 协议地址长度 */unsigned short optionCode; /* 操作方式 *//*mac地址 IP地址*/unsigned char srcMac[6]; /* 发送方硬件地址 */unsigned char szSrcIp[4]; /* 发送方IP地址 */unsigned char dstMac[6]; /* 接收方硬件地址 */unsigned char szDstIp[4]; /* 接收方IP地址 */
} ARP_PARAM; void makeArpMsg(ARP_PARAM *pArpMsg, unsigned char *srcMac, unsigned char *srcIp, unsigned char *dstMac, unsigned char *dstIp, int op)
{if (NULL == pArpMsg || NULL == srcMac || NULL == srcIp || NULL == dstMac || NULL == dstIp){printf("param is null!\n");return;}/*Ether*/memcpy(pArpMsg->nSrcMac, srcMac, sizeof(pArpMsg->nSrcMac));memset(pArpMsg->nDstMac, 0xff, sizeof(pArpMsg->nDstMac)); /*广播地址ff:ff:ff:ff:ff:ff*/pArpMsg->nProto = htons(ETH_P_ARP);/*ARP*/pArpMsg->hardwareType = htons(ARPHRD_ETHER);pArpMsg->protoType = htons(ETH_P_IP);pArpMsg->hardwareLen = 6; /*mac长度为6字节*/pArpMsg->protoLen = 4; /*协议长度为4字节，代表ipv4*/pArpMsg->optionCode = htons(op == 1 ? ARPOP_REQUEST : ARPOP_REPLY);/*ARP报文请求地址填写*/memcpy(pArpMsg->srcMac, srcMac, sizeof(pArpMsg->srcMac));memcpy(pArpMsg->dstMac, dstMac, sizeof(pArpMsg->dstMac));memcpy(pArpMsg->szSrcIp, srcIp, sizeof(pArpMsg->szSrcIp));memcpy(pArpMsg->szDstIp, dstIp, sizeof(pArpMsg->szDstIp));
}int main()
{/*arp*/ARP_PARAM stuMsg;unsigned char srcMac[6] = {0x00, 0x0c, 0x29, 0xf7, 0x7b, 0x0d}; // 源mac地址, ether 00:0c:29:f7:7b:0dunsigned char dstMac[6] = {0};unsigned int uSrcIp = 0;unsigned int uDstIp = 0;memset(&stuMsg, 0, sizeof(stuMsg));/*填写源ip 和目的ip*/uSrcIp = inet_addr("192.168.68.113");uDstIp = inet_addr("192.168.68.48");/*op为1代表arp报文类型为请求包*/makeArpMsg(&stuMsg, srcMac, (unsigned char *)&uSrcIp, dstMac, (unsigned char *)&uDstIp, 1);/*创建原始套接字*/int arpFd = socket(AF_PACKET, SOCK_PACKET, htons(ETH_P_ARP));/*设置socket属性为广播*/int opt = 1;setsockopt(arpFd, SOL_SOCKET, SO_BROADCAST, &opt, sizeof(opt));/*设置发送超时 避免阻塞*/struct timeval stuTimeout;stuTimeout.tv_sec = 5;stuTimeout.tv_usec = 0;setsockopt(arpFd, SOL_SOCKET, SO_SNDTIMEO, (char *)&stuTimeout, sizeof(stuTimeout));struct sockaddr sock_addr; /* for interface name */memset(&sock_addr, 0, sizeof(sock_addr));/*指定网卡发送*/memcpy(&sock_addr.sa_data, "ens33", strlen("ens33"));char recvarp[42] = {0};while (1){int iRet = sendto(arpFd, &stuMsg, sizeof(stuMsg), 0, &sock_addr, sizeof(sock_addr));if (iRet < 0){printf("send time out\n");}else{printf("send success\n");}int len = sizeof(sock_addr);if (recvfrom(arpFd, recvarp, 42, 0, &sock_addr, &len) == 42){memcpy(dstMac, recvarp + 22, 6);// 以太网的目的MACstruct ether_header *h1 = (struct ether_header *)recvarp;// ARP包struct ether_arp *arp = (struct ether_arp *)(recvarp + 14); // 以太网的源MAC6个字节 ,目的MAC 6个字节，类型为2字节int i = 0;// printf("目的MAC:");// for (i = 0; i < ETH_ALEN; i++)// {// printf("%02x-", h1->ether_dhost[i]);// }// printf("\n");// // 源MAC地址// printf("源MAC:");// for (i = 0; i < ETH_ALEN; i++)// {// printf("%02x-", h1->ether_shost[i]);// }// printf("\n");if ((ntohs)(arp->arp_op) == 2) // 判断是否是ARP响应包，如果是操作方式码为2{// 硬件类型printf("硬件类型:%0x\n", (ntohs)(arp->arp_hrd)); // 1代表硬件接口为以太网接口// 协议类型printf("协议类型:%0x\n", (ntohs)(arp->arp_pro)); // 0x800代表高层协议为IP// 硬件地址长度printf("硬件地址长度:%0x\n", arp->arp_hln);// 协议地址长度printf("协议地址长度:%0x\n", arp->arp_pln);// 发送方的MAC地址printf("发送方的MAC:");for (i = 0; i < ETH_ALEN; i++){printf("%02x-", arp->arp_sha[i]);}printf("\n");printf("发送方的IP:");char ip[16];inet_ntop(AF_INET, arp->arp_spa, &ip, 16); // arp_spa是一个unsigned char数组printf("%s\n", ip);break;}sleep(1);}}makeArpMsg(&stuMsg, srcMac, (unsigned char *)&uSrcIp, dstMac, (unsigned char *)&uDstIp, 1);while (1){if (sendto(arpFd, &stuMsg, sizeof(stuMsg), 0, &sock_addr, sizeof(sock_addr)) == 42){printf("发送ARP\n");}else{perror("发送");return EXIT_FAILURE;}sleep(1);}close(arpFd);return 0;
}