1。通过已经连接的socket文件获取：
- int getpeermac( int sockfd, char *buf )
- {
- int ret =0;
- struct arpreq arpreq;
- struct sockaddr_in dstadd_in;
- socklen_t len = sizeof( struct sockaddr_in );
- memset( &arpreq, 0, sizeof( struct arpreq ));
- memset( &dstadd_in, 0, sizeof( struct sockaddr_in ));
- if( getpeername( sockfd, (struct sockaddr*)&dstadd_in, &len ) < 0 )
- err_err("getpeername()");
- else
- {
- memcpy( &arpreq.arp_pa, &dstadd_in, sizeof( struct sockaddr_in ));
- strcpy(arpreq.arp_dev, "eth1");
- arpreq.arp_pa.sa_family = AF_INET;
- arpreq.arp_ha.sa_family = AF_UNSPEC;
- if( ioctl( sockfd, SIOCGARP, &arpreq ) < 0 )
- err_err("ioctl SIOCGARP");
- else
- {
- unsigned char* ptr = (unsigned char *)arpreq.arp_ha.sa_data;
- ret = sprintf(buf, "%02x%02x%02x%02x%02x%02x", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5));
- }
- }
- return ret;
- }
2。 通过IP获取：
- int getpeermac_by_ip(char *ipaddr, char* buf)
- {
- int sockfd;
- unsigned char *ptr;
- struct arpreq arpreq;
- struct sockaddr_in *sin;
- struct sockaddr_storage ss;
- char addr[INET_ADDRSTRLEN+1];
- memset(addr, 0, INET_ADDRSTRLEN+1);
- memset(&ss, 0, sizeof(ss));
- if (argc != 2) {
- printf("USAGE arpg ip_addr/n");
- return -1;
- }
- sockfd = socket(AF_INET, SOCK_DGRAM, 0);
- if (sockfd == -1) {
- perror("socket error");
- return -1;
- }
- sin = (struct sockaddr_in *) &ss;
- sin->sin_family = AF_INET;
- if (inet_pton(AF_INET, argv[1], &(sin->sin_addr)) <= 0) {
- perror("inet_pton error");
- return -1;
- }
- sin = (struct sockaddr_in *) &arpreq.arp_pa;
- memcpy(sin, &ss, sizeof(struct sockaddr_in));
- strcpy(arpreq.arp_dev, "eth1");
- arpreq.arp_ha.sa_family = AF_UNSPEC;
- if (ioctl(sockfd, SIOCGARP, &arpreq) < 0) {
- perror("ioctl SIOCGARP: ");
- return -1;
- }
- ptr = (unsigned char *)arpreq.arp_ha.sa_data;
- sprintf(buf,"%x:%x:%x:%x:%x:%x", *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5));
- return 0;
- }
