通过IP或socket获取对方的MAC地址

通过IP或socket获取对方的MAC地址 收藏
 1。通过已经连接的socket文件获取：

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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;  
}  
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：

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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;  
}