af_wanpipe.c

Linux Kernel 2.6.9 for OMAP1710

	mbox_ptr = (mbox_cmd_t*)wp_sk(sk)->mbox;
	memset(mbox_ptr, 0, sizeof(mbox_cmd_t));

	if (usr_data == NULL){
		return 0;
	}
	if ((err=get_user(mbox_ptr->cmd.qdm, &usr_data->hdr.qdm)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.cause, &usr_data->hdr.cause)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.diagn, &usr_data->hdr.diagn)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.length, &usr_data->hdr.length)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.result, &usr_data->hdr.result)))
		return err;

	if (mbox_ptr->cmd.length > 0){
		if (mbox_ptr->cmd.length > X25_MAX_DATA)
			return -EINVAL;

		if (copy_from_user(mbox_ptr->data, usr_data->data, mbox_ptr->cmd.length)){
			printk(KERN_INFO "Copy failed\n");
			return -EFAULT;
		}
	}
	return 0;
}


/*======================================================================
 * wanpipe_poll
 *
 *	Datagram poll: Again totally generic. This also handles
 *	sequenced packet sockets providing the socket receive queue
 *	is only ever holding data ready to receive.
 *
 *	Note: when you _don't_ use this routine for this protocol,
 *	and you use a different write policy from sock_writeable()
 *	then please supply your own write_space callback.
 *=====================================================================*/

unsigned int wanpipe_poll(struct file * file, struct socket *sock, poll_table *wait)
{
	struct sock *sk = sock->sk;
	unsigned int mask;

	++wp_sk(sk)->poll_cnt;

	poll_wait(file, sk->sk_sleep, wait);
	mask = 0;

	/* exceptional events? */
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) {
		mask |= POLLPRI;
		return mask;
	}
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= POLLHUP;

	/* readable? */
	if (!skb_queue_empty(&sk->sk_receive_queue)) {
		mask |= POLLIN | POLLRDNORM;
	}

	/* connection hasn't started yet */
	if (sk->sk_state == WANSOCK_CONNECTING) {
		return mask;
	}

	if (sk->sk_state == WANSOCK_DISCONNECTED) {
		mask = POLLPRI;
		return mask;
	}

	/* This check blocks the user process if there is   
	 * a packet already queued in the socket write queue.
         * This option is only for X25API protocol, for other
         * protocol like chdlc enable streaming mode, 
         * where multiple packets can be pending in the socket 
         * transmit queue */

	if (wp_sk(sk)->num == htons(X25_PROT)) {
		if (atomic_read(&wp_sk(sk)->packet_sent))
			return mask;
	}

	/* writable? */
	if (sock_writeable(sk)){
		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
	}else{
		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
	}
		
	return mask;
}

/*======================================================================
 * wanpipe_listen
 *
 *	X25API Specific function. Set a socket into LISTENING  MODE.
 *=====================================================================*/


static int wanpipe_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;

 	/* This is x25 specific area if protocol doesn't
         * match, return error */
	if (wp_sk(sk)->num != htons(X25_PROT))
		return -EINVAL;

	if (sk->sk_state == WANSOCK_BIND_LISTEN) {

		sk->sk_max_ack_backlog = backlog;
		sk->sk_state           = WANSOCK_LISTEN;
		return 0;
	}else{
		printk(KERN_INFO "wansock: Listening sock was not binded\n");
	}

	return -EINVAL;
}

/*======================================================================
 * wanpipe_link_card
 *
 *	Connects the listening socket to the driver
 *=====================================================================*/

static int wanpipe_link_card (struct sock *sk)
{
	sdla_t *card = (sdla_t*)wp_sk(sk)->card;

	if (!card)
		return -ENOMEM;

	if ((card->sk != NULL) || (card->func != NULL)){
		printk(KERN_INFO "wansock: Listening queue is already established\n");
		return -EINVAL;
	}

	card->sk=sk;
	card->func=wanpipe_listen_rcv;
	sk->sk_zapped = 1;
 
	return 0;
}

/*======================================================================
 * wanpipe_listen
 *
 *	X25API Specific function. Disconnect listening socket from
 *      the driver.
 *=====================================================================*/

static void wanpipe_unlink_card (struct sock *sk)
{
	sdla_t *card = (sdla_t*)wp_sk(sk)->card; 

	if (card){
		card->sk=NULL;
		card->func=NULL;
	}
}

/*======================================================================
 * wanpipe_exec_cmd
 *
 *	Ioctl function calls this function to execute user command.
 *      Connect() sytem call also calls this function to execute
 *      place call.  This function blocks until command is executed.
 *=====================================================================*/

static int wanpipe_exec_cmd(struct sock *sk, int cmd, unsigned int flags)
{
	int err = -EINVAL;
	wanpipe_opt *wp = wp_sk(sk);
	mbox_cmd_t *mbox_ptr = (mbox_cmd_t*)wp->mbox;

	if (!mbox_ptr){
		printk(KERN_INFO "NO MBOX PTR !!!!!\n");
		return -EINVAL;
	}
	
	/* This is x25 specific area if protocol doesn't
         * match, return error */
	if (wp->num != htons(X25_PROT))
		return -EINVAL;


	switch (cmd){

		case SIOC_WANPIPE_ACCEPT_CALL:

			if (sk->sk_state != WANSOCK_CONNECTING) {
				err = -EHOSTDOWN;
				break;
			}
			
			err = execute_command(sk,X25_ACCEPT_CALL,0);
			if (err < 0)
				break;

			/* Update. Mar6 2000. 
                         * Do not set the sock lcn number here, since
                         * it is done in wanpipe_listen_rcv(). 
                         */ 
		 	if (sk->sk_state == WANSOCK_CONNECTED) {
				wp->lcn = ((mbox_cmd_t*)wp->mbox)->cmd.lcn;	
				DBG_PRINTK(KERN_INFO "\nwansock: Accept OK %i\n",
					wp->lcn);
				err = 0;

			}else{
				DBG_PRINTK (KERN_INFO "\nwansock: Accept Failed %i\n",
					wp->lcn);
				wp->lcn = 0;
				err = -ECONNREFUSED;
			}
			break;

		case SIOC_WANPIPE_CLEAR_CALL:

			if (sk->sk_state == WANSOCK_DISCONNECTED) {
				err = -EINVAL;
				break;
			}


			/* Check if data buffers are pending for transmission,
                         * if so, check whether user wants to wait until data
                         * is transmitted, or clear a call and drop packets */
                          
			if (atomic_read(&sk->sk_wmem_alloc) ||
			    check_driver_busy(sk)) {
			  	mbox_cmd_t *mbox = wp->mbox;
				if (mbox->cmd.qdm & 0x80){
					mbox->cmd.result = 0x35;
					err = -EAGAIN;	
					break;
				}
			}

			sk->sk_state = WANSOCK_DISCONNECTING;

			err = execute_command(sk,X25_CLEAR_CALL,0);
			if (err < 0)
				break;

			err = -ECONNREFUSED;
			if (sk->sk_state == WANSOCK_DISCONNECTED) {
				DBG_PRINTK(KERN_INFO "\nwansock: CLEAR OK %i\n",
					   wp->lcn);
				wp->lcn = 0;
				err = 0;
			}
			break;

		case SIOC_WANPIPE_RESET_CALL:

			if (sk->sk_state != WANSOCK_CONNECTED) {
				err = -EINVAL;
				break;
			}


			/* Check if data buffers are pending for transmission,
                         * if so, check whether user wants to wait until data
                         * is transmitted, or reset a call and drop packets */
                          
			if (atomic_read(&sk->sk_wmem_alloc) ||
			    check_driver_busy(sk)) {
			  	mbox_cmd_t *mbox = wp->mbox;
				if (mbox->cmd.qdm & 0x80){
					mbox->cmd.result = 0x35;
					err = -EAGAIN;	
					break;
				}
			}


			err = execute_command(sk, X25_RESET,0);
			if (err < 0)
				break;

			err = mbox_ptr->cmd.result;
			break;


		case X25_PLACE_CALL:

			err=execute_command(sk,X25_PLACE_CALL,flags);
			if (err < 0)
				break;

			if (sk->sk_state == WANSOCK_CONNECTED) {

				wp->lcn = ((mbox_cmd_t*)wp->mbox)->cmd.lcn;	

				DBG_PRINTK(KERN_INFO "\nwansock: PLACE CALL OK %i\n",
					wp->lcn);
				err = 0;

			} else if (sk->sk_state == WANSOCK_CONNECTING &&
				   (flags & O_NONBLOCK)) {
				wp->lcn = ((mbox_cmd_t*)wp->mbox)->cmd.lcn;
				DBG_PRINTK(KERN_INFO "\nwansock: Place Call OK: Waiting %i\n",
					wp->lcn);

				err = 0;

			}else{
				DBG_PRINTK(KERN_INFO "\nwansock: Place call Failed\n");
				err = -ECONNREFUSED;
			}

			break;

		default: 
			return -EINVAL;
	}

	return err;
}

static int check_driver_busy (struct sock *sk)
{
	struct net_device *dev = dev_get_by_index(sk->sk_bound_dev_if);
	wanpipe_common_t *chan;

	if (!dev)
		return 0;

	dev_put(dev);

	if ((chan=dev->priv) == NULL)
		return 0;

	return atomic_read(&chan->driver_busy);
}


/*======================================================================
 * wanpipe_accept
 *
 *	ACCEPT() System call.	X25API Specific function. 
 *	For each incoming call, create a new socket and 
 *      return it to the user.	
 *=====================================================================*/

static int wanpipe_accept(struct socket *sock, struct socket *newsock, int flags)
{
	struct sock *sk;
	struct sock *newsk;
	struct sk_buff *skb;
	DECLARE_WAITQUEUE(wait, current);
	int err=0;

	if (newsock->sk != NULL){
		wanpipe_kill_sock_accept(newsock->sk);	
		newsock->sk=NULL;
	}
	
	if ((sk = sock->sk) == NULL)
		return -EINVAL;

	if (sk->sk_type != SOCK_RAW)
		return -EOPNOTSUPP;

	if (sk->sk_state != WANSOCK_LISTEN)
		return -EINVAL;

	if (wp_sk(sk)->num != htons(X25_PROT))
		return -EINVAL;

	add_wait_queue(sk->sk_sleep,&wait);
	current->state = TASK_INTERRUPTIBLE;
	for (;;){
		skb = skb_dequeue(&sk->sk_receive_queue);
		if (skb){
			err=0;
			break;
		}
		if (signal_pending(current)) {
			err = -ERESTARTSYS;
			break;
		}
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(sk->sk_sleep,&wait);
	
	if (err != 0)
		return err;
	
	newsk = get_newsk_from_skb(skb);
	if (!newsk){
		return -EINVAL;
	}

	set_bit(1,&wanpipe_tx_critical);
	write_lock(&wanpipe_sklist_lock);
	sk_add_node(newsk, &wanpipe_sklist);
	write_unlock(&wanpipe_sklist_lock);
	clear_bit(1,&wanpipe_tx_critical);

	newsk->sk_socket = newsock;
	newsk->sk_sleep = &newsock->wait;

	/* Now attach up the new socket */
	sk->sk_ack_backlog--;
	newsock->sk = newsk;
	
	kfree_skb(skb);

	DBG_PRINTK(KERN_INFO "\nwansock: ACCEPT Got LCN %i\n",
		   wp_sk(newsk)->lcn);
	return 0;
}

/*======================================================================
 *  get_newsk_from_skb
 *
 *	Accept() uses this function to get the address of the new
 *      socket structure.
 *=====================================================================*/

struct sock * get_newsk_from_skb (struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	wanpipe_common_t *chan;	

	if (!dev){
		return NULL;
	}
		
	if ((chan = dev->priv) == NULL){
		return NULL;
	}
		
	if (!chan->sk){
		return NULL;
	}
	return (struct sock *)chan->sk;
}

/*======================================================================
 *  wanpipe_connect
 *
 *  	CONNECT() System Call. X25API specific function
 * 	Check the state of the sock, and execute PLACE_CALL command.
 *      Connect can ether block or return without waiting for connection, 
 *      if specified by user.
 *=====================================================================*/

static int wanpipe_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags)
{
	struct sock *sk = sock->sk;
	struct wan_sockaddr_ll *addr = (struct wan_sockaddr_ll*)uaddr;
	struct net_device *dev;
	int err;

	if (wp_sk(sk)->num != htons(X25_PROT))
		return -EINVAL;

	if (sk->sk_state == WANSOCK_CONNECTED)
		return -EISCONN;	/* No reconnect on a seqpacket socket */

	if (sk->sk_state != WAN_DISCONNECTED) {
		printk(KERN_INFO "wansock: Trying to connect on channel NON DISCONNECT\n");
		return -ECONNREFUSED;
	}

	sk->sk_state = WANSOCK_DISCONNECTED;	
	sock->state  = SS_UNCONNECTED;

	if (addr_len != sizeof(struct wan_sockaddr_ll))
		return -EINVAL;

	if (addr->sll_family != AF_WANPIPE)
		return -EINVAL;

	if ((dev = dev_get_by_index(sk->sk_bound_dev_if)) == NULL)
		return -ENETUNREACH;

	dev_put(dev);
	
	if (!sk->sk_zapped) /* Must bind first - autobinding does not work */
		return -EINVAL;

	sock->state   = SS_CONNECTING;
	sk->sk_state  = WANSOCK_CONNECTING;

	if (!wp_sk(sk)->mbox) {
		if (wp_sk (sk)->svc)
			return -EINVAL;
		else {
			int err;
			if ((err=set_ioctl_cmd(sk,