af_wanpipe.c

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}

/*============================================================
 * get_atomic_device
 *	
 *	Sets a bit atomically which indicates that 
 *      the interface is taken. This avoids race conditions.
 *===========================================================*/


static inline int get_atomic_device (netdevice_t *dev)
{
	wanpipe_common_t *chan = dev->priv;
	if (!test_and_set_bit(0,(void *)&chan->rw_bind)){
		return 0;
	}
	return 1;
}

/*============================================================
 * check_dev
 *	
 *  	Check that device name belongs to a particular card.
 *===========================================================*/

static int check_dev (netdevice_t *dev, sdla_t *card)
{
	netdevice_t* tmp_dev;

	for (tmp_dev = card->wandev.dev; tmp_dev; tmp_dev=*((netdevice_t**)tmp_dev->priv)){
		if (tmp_dev->ifindex == dev->ifindex){ 
			return 0;	
		}
	}
	return 1;
}

/*============================================================
 *  wanpipe_find_free_dev
 *	
 *	Find a free network interface. If found set atomic
 *      bit indicating that the interface is taken.
 *      X25API Specific.
 *===========================================================*/

netdevice_t * wanpipe_find_free_dev (sdla_t *card)
{
	netdevice_t* dev;
	volatile wanpipe_common_t *chan;

	if (test_and_set_bit(0,&find_free_critical)){
		printk(KERN_INFO "CRITICAL in Find Free\n");
	}	

	for (dev = card->wandev.dev; dev; dev=*((netdevice_t**)dev->priv)){
		chan = dev->priv;
		if (!chan) 
			continue;
		if (chan->usedby == API && chan->svc){
			if (!get_atomic_device (dev)){
				if (chan->state != WANSOCK_DISCONNECTED){
					release_device(dev);
				}else{
					clear_bit(0,&find_free_critical);
					return dev;
				}
			}
		}
	}
	clear_bit(0,&find_free_critical);
	return NULL;
}

/*============================================================
 *  wanpipe_create
 *	
 * 	SOCKET() System call.  It allocates a sock structure
 *      and adds the socket to the wanpipe_sk_list. 
 *      Crates AF_WANPIPE socket.
 *===========================================================*/

static int wanpipe_create(struct socket *sock, int protocol)
{
	struct sock *sk;
	
	//FIXME: This checks for root user, SECURITY ?
	//if (!capable(CAP_NET_RAW))
	//	return -EPERM;

	if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
		return -ESOCKTNOSUPPORT;

	sock->state = SS_UNCONNECTED;

	if ((sk = wanpipe_alloc_socket()) == NULL)
		return -ENOBUFS;

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

	sk->zapped=0;
	sk->family = PF_WANPIPE;
	sk->num = protocol;
	sk->state = WANSOCK_DISCONNECTED;
	sk->ack_backlog = 0;
	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->next = wanpipe_sklist;
	wanpipe_sklist = sk;
	sock_hold(sk);
	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 socket *sock, struct msghdr *msg, int len,
			  int flags, struct scm_cookie *scm)
{
	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->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;
	
#ifdef LINUX_2_1
	sk->stamp=skb->stamp;
#else
	sock_recv_timestamp(msg, sk, skb);
#endif
	
	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)
{
	netdevice_t *dev=NULL;
	wanpipe_common_t *chan=NULL;

	dev = dev_get_by_index(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->rmem_alloc) < ((unsigned)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)
{
	netdevice_t *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->bound_dev_if;
	sll->sll_protocol = sk->num;
	dev = dev_get_by_index(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;
	netdevice_t *dev = (netdevice_t*)data;
	struct wanpipe_opt *po;

	for (sk = wanpipe_sklist; sk; sk = sk->next) {

		if ((po = sk->protinfo.af_wanpipe)==NULL)
			continue;
		if (dev == NULL)
			continue;
		
		switch (msg) {
		case NETDEV_DOWN:
		case NETDEV_UNREGISTER:
			if (dev->ifindex == sk->bound_dev_if) {
				printk(KERN_INFO "wansock: Device down %s\n",dev->name);
				if (sk->zapped){
					wanpipe_unlink_driver(sk);
					sk->err = ENETDOWN;
					sk->error_report(sk);
				}

				if (msg == NETDEV_UNREGISTER) {
					printk(KERN_INFO "wansock: Unregistering Device: %s\n",
						 	  dev->name);
					wanpipe_unlink_driver(sk);
					sk->bound_dev_if = 0;
				}
			}
			break;
		case NETDEV_UP:
			if (dev->ifindex == sk->bound_dev_if && sk->num && !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;
	int pid;

	switch(cmd) 
	{
		case FIOSETOWN:
		case SIOCSPGRP:
			err = get_user(pid, (int *) arg);
			if (err)
				return err; 
			if (current->pid != pid && current->pgrp != -pid && 
			    !capable(CAP_NET_ADMIN))
				return -EPERM;
			sk->proc = pid;
			return(0);
		case FIOGETOWN:
		case SIOCGPGRP:
			return put_user(sk->proc, (int *)arg);
		case SIOCGSTAMP:
			if(sk->stamp.tv_sec==0)
				return -ENOENT;
			err = -EFAULT;
			if (!copy_to_user((void *)arg, &sk->stamp, sizeof(struct timeval)))
				err = 0;
			return err;

		case SIOC_WANPIPE_CHECK_TX:

			return atomic_read(&sk->wmem_alloc);

		case SIOC_WANPIPE_SOCK_STATE:

			if (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->state != WANSOCK_DISCONNECTED)
				return -EINVAL;

			sock->file->f_flags |= O_NONBLOCK;
			return 0;
	
		case SIOCGIFFLAGS:
#ifndef CONFIG_INET
		case SIOCSIFFLAGS:
#endif
		case SIOCGIFCONF:
		case SIOCGIFMETRIC:
		case SIOCSIFMETRIC:
		case SIOCGIFMEM:
		case SIOCSIFMEM:
		case SIOCGIFMTU:
		case SIOCSIFMTU:
		case SIOCSIFLINK:
		case SIOCGIFHWADDR:
		case SIOCSIFHWADDR:
		case SIOCSIFMAP:
		case SIOCGIFMAP:
		case SIOCSIFSLAVE:
		case SIOCGIFSLAVE:
		case SIOCGIFINDEX:
		case SIOCGIFNAME:
		case SIOCGIFCOUNT:
		case SIOCSIFHWBROADCAST:
			return(dev_ioctl(cmd,(void *) arg));

#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:
		case SIOCADDDLCI:
		case SIOCDELDLCI:
			return inet_dgram_ops.ioctl(sock, cmd, arg);
#endif

		default:
			if ((cmd >= SIOCDEVPRIVATE) &&
			    (cmd <= (SIOCDEVPRIVATE + 15)))
				return(dev_ioctl(cmd,(void *) arg));

#ifdef CONFIG_NET_RADIO
			if((cmd >= SIOCIWFIRST) && (cmd <= SIOCIWLAST))
				return(dev_ioctl(cmd,(void *) arg));
#endif
			return -EOPNOTSUPP;
	}
	/*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=NULL;
	netdevice_t *dev=NULL;
	wanpipe_common_t *chan=NULL;
	int cnt=0, err=0;
	wan_debug_t *dbg_data = (wan_debug_t *)arg;

	for (sk = wanpipe_sklist; sk; sk = sk->next){

		if (sk == origsk){
			continue;
		}