af_wanpipe.c

Linux Kernel 2.6.9 for OMAP1710

	sk->sk_reuse = 1;
	sock->ops = &wanpipe_ops;
	sock_init_data(sock,sk);

	sk->sk_zapped	    = 0;
	sk->sk_family	    = PF_WANPIPE;
	wp_sk(sk)->num	    = protocol;
	sk->sk_state	    = WANSOCK_DISCONNECTED;
	sk->sk_ack_backlog  = 0;
	sk->sk_bound_dev_if = 0;

	atomic_inc(&wanpipe_socks_nr);
	
	/* We must disable interrupts because the ISR
	 * can also change the list */
	set_bit(1,&wanpipe_tx_critical);
	write_lock(&wanpipe_sklist_lock);
	sk_add_node(sk, &wanpipe_sklist);
	write_unlock(&wanpipe_sklist_lock);
	clear_bit(1,&wanpipe_tx_critical);

	return(0);
}


/*============================================================
 *  wanpipe_recvmsg
 *	
 *	Pull a packet from our receive queue and hand it 
 *      to the user. If necessary we block.
 *===========================================================*/

static int wanpipe_recvmsg(struct kiocb *iocb, struct socket *sock,
			   struct msghdr *msg, int len, int flags)
{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	int copied, err=-ENOBUFS;


	/*
	 *	If the address length field is there to be filled in, we fill
	 *	it in now.
	 */

	msg->msg_namelen = sizeof(struct wan_sockaddr_ll);

	/*
	 *	Call the generic datagram receiver. This handles all sorts
	 *	of horrible races and re-entrancy so we can forget about it
	 *	in the protocol layers.
	 *
	 *	Now it will return ENETDOWN, if device have just gone down,
	 *	but then it will block.
	 */

	if (flags & MSG_OOB){	
		skb = skb_dequeue(&sk->sk_error_queue);
	}else{
		skb=skb_recv_datagram(sk,flags,1,&err);
	}
	/*
	 *	An error occurred so return it. Because skb_recv_datagram() 
	 *	handles the blocking we don't see and worry about blocking
	 *	retries.
	 */

	if(skb==NULL)
		goto out;

	/*
	 *	You lose any data beyond the buffer you gave. If it worries a
	 *	user program they can ask the device for its MTU anyway.
	 */

	copied = skb->len;
	if (copied > len)
	{
		copied=len;
		msg->msg_flags|=MSG_TRUNC;
	}

	wanpipe_wakeup_driver(sk);

	/* We can't use skb_copy_datagram here */
	err = memcpy_toiovec(msg->msg_iov, skb->data, copied);
	if (err)
		goto out_free;
	
	sock_recv_timestamp(msg, sk, skb);
	
	if (msg->msg_name)
		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);

	/*
	 *	Free or return the buffer as appropriate. Again this
	 *	hides all the races and re-entrancy issues from us.
	 */
	err = (flags&MSG_TRUNC) ? skb->len : copied;

out_free:
	skb_free_datagram(sk, skb);
out:
	return err;
}


/*============================================================
 *  wanpipe_wakeup_driver
 *	
 * 	If socket receive buffer is full and driver cannot
 *      pass data up the sock, it sets a packet_block flag.
 *      This function check that flag and if sock receive 
 *      queue has room it kicks the driver BH handler. 
 *
 * 	This way, driver doesn't have to poll the sock 
 *      receive queue.
 *===========================================================*/

static void wanpipe_wakeup_driver(struct sock *sk)
{
	struct net_device *dev = NULL;
	wanpipe_common_t *chan=NULL;

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

	dev_put(dev);

	if ((chan = dev->priv) == NULL)
		return;
	
	if (atomic_read(&chan->receive_block)){  
		if (atomic_read(&sk->sk_rmem_alloc) <
		    ((unsigned)sk->sk_rcvbuf * 0.9)) {
			printk(KERN_INFO "wansock: Queuing task for wanpipe\n");
			atomic_set(&chan->receive_block,0);
			wanpipe_queue_tq(&chan->wanpipe_task);
			wanpipe_mark_bh();
		}
	}	
}	

/*============================================================
 *  wanpipe_getname
 *	
 * 	I don't know what to do with this yet. 
 *      User can use this function to get sock address
 *      information. Not very useful for Sangoma's purposes.
 *===========================================================*/


static int wanpipe_getname(struct socket *sock, struct sockaddr *uaddr,
			  int *uaddr_len, int peer)
{
	struct net_device *dev;
	struct sock *sk = sock->sk;
	struct wan_sockaddr_ll *sll = (struct wan_sockaddr_ll*)uaddr;

	sll->sll_family = AF_WANPIPE;
	sll->sll_ifindex = sk->sk_bound_dev_if;
	sll->sll_protocol = wp_sk(sk)->num;
	dev = dev_get_by_index(sk->sk_bound_dev_if);
	if (dev) {
		sll->sll_hatype = dev->type;
		sll->sll_halen = dev->addr_len;
		memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
	} else {
		sll->sll_hatype = 0;	/* Bad: we have no ARPHRD_UNSPEC */
		sll->sll_halen = 0;
	}
	*uaddr_len = sizeof(*sll);
	
	dev_put(dev);
	
	return 0;
}

/*============================================================
 *  wanpipe_notifier
 *	
 *	If driver turns off network interface, this function
 *      will be envoked. Currently I treate it as a 
 *      call disconnect. More thought should go into this
 *      function.
 *
 * FIXME: More thought should go into this function.
 *
 *===========================================================*/

static int wanpipe_notifier(struct notifier_block *this, unsigned long msg, void *data)
{
	struct sock *sk;
	hlist_node *node;
	struct net_device *dev = (struct net_device *)data;

	sk_for_each(sk, node, &wanpipe_sklist) {
		struct wanpipe_opt *po = wp_sk(sk);

		if (!po)
			continue;
		if (dev == NULL)
			continue;
		
		switch (msg) {
		case NETDEV_DOWN:
		case NETDEV_UNREGISTER:
			if (dev->ifindex == sk->sk_bound_dev_if) {
				printk(KERN_INFO "wansock: Device down %s\n",dev->name);
				if (sk->sk_zapped) {
					wanpipe_unlink_driver(sk);
					sk->sk_err = ENETDOWN;
					sk->sk_error_report(sk);
				}

				if (msg == NETDEV_UNREGISTER) {
					printk(KERN_INFO "wansock: Unregistering Device: %s\n",
						 	  dev->name);
					wanpipe_unlink_driver(sk);
					sk->sk_bound_dev_if = 0;
				}
			}
			break;
		case NETDEV_UP:
			if (dev->ifindex == sk->sk_bound_dev_if &&
			    po->num && !sk->sk_zapped) {
				printk(KERN_INFO "wansock: Registering Device: %s\n",
						dev->name);
				wanpipe_link_driver(dev,sk);
			}
			break;
		}
	}
	return NOTIFY_DONE;
}

/*============================================================
 *  wanpipe_ioctl
 *	
 * 	Execute a user commands, and set socket options.
 *
 * FIXME: More thought should go into this function.
 *
 *===========================================================*/

static int wanpipe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;
	int err;

	switch(cmd) 
	{
		case SIOCGSTAMP:
			return sock_get_timestamp(sk, (struct timeval __user *)arg);

		case SIOC_WANPIPE_CHECK_TX:

			return atomic_read(&sk->sk_wmem_alloc);

		case SIOC_WANPIPE_SOCK_STATE:

			if (sk->sk_state == WANSOCK_CONNECTED)
				return 0;
			
			return 1;


		case SIOC_WANPIPE_GET_CALL_DATA:

			return get_ioctl_cmd (sk,(void*)arg);

		case SIOC_WANPIPE_SET_CALL_DATA:

			return set_ioctl_cmd (sk,(void*)arg);

		case SIOC_WANPIPE_ACCEPT_CALL:
		case SIOC_WANPIPE_CLEAR_CALL:
		case SIOC_WANPIPE_RESET_CALL:

			if ((err=set_ioctl_cmd(sk,(void*)arg)) < 0)
				return err;

			err=wanpipe_exec_cmd(sk,cmd,0);
			get_ioctl_cmd(sk,(void*)arg);
			return err;

		case SIOC_WANPIPE_DEBUG:

			return wanpipe_debug(sk,(void*)arg);
	
		case SIOC_WANPIPE_SET_NONBLOCK:

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

			sock->file->f_flags |= O_NONBLOCK;
			return 0;
	
#ifdef CONFIG_INET
		case SIOCADDRT:
		case SIOCDELRT:
		case SIOCDARP:
		case SIOCGARP:
		case SIOCSARP:
		case SIOCDRARP:
		case SIOCGRARP:
		case SIOCSRARP:
		case SIOCGIFADDR:
		case SIOCSIFADDR:
		case SIOCGIFBRDADDR:
		case SIOCSIFBRDADDR:
		case SIOCGIFNETMASK:
		case SIOCSIFNETMASK:
		case SIOCGIFDSTADDR:
		case SIOCSIFDSTADDR:
		case SIOCSIFFLAGS:
			return inet_dgram_ops.ioctl(sock, cmd, arg);
#endif

		default:
			return dev_ioctl(cmd,(void __user *) arg);
	}
	/*NOTREACHED*/
}

/*============================================================
 *  wanpipe_debug
 *	
 *	This function will pass up information about all
 *      active sockets.
 *
 * FIXME: More thought should go into this function.
 *
 *===========================================================*/

static int wanpipe_debug (struct sock *origsk, void *arg)
{
	struct sock *sk;
	struct hlist_node *node;
	struct net_device *dev = NULL;
	wanpipe_common_t *chan=NULL;
	int cnt=0, err=0;
	wan_debug_t *dbg_data = (wan_debug_t *)arg;

	sk_for_each(sk, node, &wanpipe_sklist) {
		wanpipe_opt *wp = wp_sk(sk);

		if (sk == origsk){
			continue;
		}

		if ((err=put_user(1, &dbg_data->debug[cnt].free)))
			return err;
		if ((err = put_user(sk->sk_state,
				    &dbg_data->debug[cnt].state_sk)))
			return err;
		if ((err = put_user(sk->sk_rcvbuf,
				    &dbg_data->debug[cnt].rcvbuf)))
			return err;
		if ((err = put_user(atomic_read(&sk->sk_rmem_alloc),
				    &dbg_data->debug[cnt].rmem)))
			return err;
		if ((err = put_user(atomic_read(&sk->sk_wmem_alloc),
				    &dbg_data->debug[cnt].wmem)))
			return err;
		if ((err = put_user(sk->sk_sndbuf,
				    &dbg_data->debug[cnt].sndbuf)))
			return err;
		if ((err=put_user(sk_count, &dbg_data->debug[cnt].sk_count)))
			return err;
		if ((err=put_user(wp->poll_cnt, &dbg_data->debug[cnt].poll_cnt)))
			return err;
		if ((err = put_user(sk->sk_bound_dev_if,
				    &dbg_data->debug[cnt].bound)))
			return err;

		if (sk->sk_bound_dev_if) {
			dev = dev_get_by_index(sk->sk_bound_dev_if);
			if (!dev)	
				continue;

			chan=dev->priv;
			dev_put(dev);
	
			if ((err=put_user(chan->state, &dbg_data->debug[cnt].d_state)))
				return err;
			if ((err=put_user(chan->svc, &dbg_data->debug[cnt].svc)))
				return err;

			if ((err=put_user(atomic_read(&chan->command), 
						&dbg_data->debug[cnt].command)))
				return err;


			if (wp){
				sdla_t *card = (sdla_t*)wp->card;			
	
				if (card){
					if ((err=put_user(atomic_read(&card->u.x.command_busy), 
								&dbg_data->debug[cnt].cmd_busy)))
						return err;
				}

				if ((err=put_user(wp->lcn, 
						  &dbg_data->debug[cnt].lcn)))
					return err;
				
				if (wp->mbox) {
					if ((err=put_user(1, &dbg_data->debug[cnt].mbox)))
						return err;
				}
			}

			if ((err=put_user(atomic_read(&chan->receive_block), 
								&dbg_data->debug[cnt].rblock)))
				return err;

			if (copy_to_user(dbg_data->debug[cnt].name, dev->name, strlen(dev->name)))
				return -EFAULT;
		}
	
		if (++cnt == MAX_NUM_DEBUG)
			break;
	}
	return 0;
}

/*============================================================
 *  get_ioctl_cmd
 *	
 *	Pass up the contents of socket MBOX to the user.
 *===========================================================*/

static int get_ioctl_cmd (struct sock *sk, void *arg)
{
	x25api_t *usr_data = (x25api_t *)arg;
	mbox_cmd_t *mbox_ptr;
	int err;

	if (usr_data == NULL)
		return -EINVAL;

	if (!wp_sk(sk)->mbox) {
		return -EINVAL;
	}

	mbox_ptr = (mbox_cmd_t *)wp_sk(sk)->mbox;

	if ((err=put_user(mbox_ptr->cmd.qdm, &usr_data->hdr.qdm)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.cause, &usr_data->hdr.cause)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.diagn, &usr_data->hdr.diagn)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.length, &usr_data->hdr.length)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.result, &usr_data->hdr.result)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.lcn, &usr_data->hdr.lcn)))
		return err;	

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

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

/*============================================================
 *  set_ioctl_cmd
 *	
 *	Before command can be execute, socket MBOX must
 *      be created, and initialized with user data.	
 *===========================================================*/

static int set_ioctl_cmd (struct sock *sk, void *arg)
{
	x25api_t *usr_data = (x25api_t *)arg;
	mbox_cmd_t *mbox_ptr;
	int err;

	if (!wp_sk(sk)->mbox) {
		void *mbox_ptr;
		struct net_device *dev = dev_get_by_index(sk->sk_bound_dev_if);
		if (!dev)
			return -ENODEV;

		dev_put(dev);
		
		if ((mbox_ptr = kmalloc(sizeof(mbox_cmd_t), GFP_ATOMIC)) == NULL)
			return -ENOMEM;

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

		wanpipe_link_driver(dev,sk);
	}