I suggested using file_open() and file_ioctl() in a previous email. That is wrong. file_ioctl() cannot be used to access socket_ioctls(). You would have to use psock_ioctl().
Because the socket interface goes though the network, there are some hand shakes and interlocks to prevent network activity while accessing the PHY interface. I think using a custom interface would be problematic. It would be best to use the internal OS socket interfaces directly. They prototyped and described in include/nuttx/net/net.h. For example, instead of using socket() you would use psock_socket(), instead of using bind(), you would use psock_bind(), instead of using ioctl(), you would use psock_ioctl().
The APIs are the same as the user space APIs exception that: (1) the are prefaced with psock_ and (2) the do not use an int socket descriptor. Rather, they use a pointer to the internal socket structure struct socket *
