int len;

error = kernel_getpeername(clientsocket, 
    (struct sockaddr *)&address, &len); 
if (error < 0) {
    sock_release(clientsocket);
    return NULL;
}
printk(KERN_INFO "new connection (%d) from %u.%u.%u.%u\n", error,
    (unsigned char)address.sa_data[2],
    (unsigned char)address.sa_data[3],
    (unsigned char)address.sa_data[4],
    (unsigned char)address.sa_data[5]);