clip.c

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	struct atm_vcc *vcc;
	int old;
	unsigned long flags;

	DPRINTK("clip_start_xmit (skb %p)\n",skb);
	if (!skb->dst) {
		printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
		dev_kfree_skb(skb);
		clip_priv->stats.tx_dropped++;
		return 0;
	}
	if (!skb->dst->neighbour) {
#if 0
		skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
		if (!skb->dst->neighbour) {
			dev_kfree_skb(skb); /* lost that one */
			clip_priv->stats.tx_dropped++;
			return 0;
		}
#endif
		printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
		dev_kfree_skb(skb);
		clip_priv->stats.tx_dropped++;
		return 0;
	}
	entry = NEIGH2ENTRY(skb->dst->neighbour);
	if (!entry->vccs) {
		if (time_after(jiffies, entry->expires)) {
			/* should be resolved */
			entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
			to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
		}
		if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
			skb_queue_tail(&entry->neigh->arp_queue,skb);
		else {
			dev_kfree_skb(skb);
			clip_priv->stats.tx_dropped++;
		}
		return 0;
	}
	DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
	ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
	DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
	if (entry->vccs->encap) {
		void *here;

		here = skb_push(skb,RFC1483LLC_LEN);
		memcpy(here,llc_oui,sizeof(llc_oui));
		((u16 *) here)[3] = skb->protocol;
	}
	atomic_add(skb->truesize,&vcc->tx_inuse);
	ATM_SKB(skb)->iovcnt = 0;
	ATM_SKB(skb)->atm_options = vcc->atm_options;
	entry->vccs->last_use = jiffies;
	DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
	old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
	if (old) {
		printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
		return 0;
	}
	clip_priv->stats.tx_packets++;
	clip_priv->stats.tx_bytes += skb->len;
	(void) vcc->send(vcc,skb);
	if (atm_may_send(vcc,0)) {
		entry->vccs->xoff = 0;
		return 0;
	}
	spin_lock_irqsave(&clip_priv->xoff_lock,flags);
	netif_stop_queue(dev); /* XOFF -> throttle immediately */
	barrier();
	if (!entry->vccs->xoff)
		netif_start_queue(dev);
		/* Oh, we just raced with clip_pop. netif_start_queue should be
		   good enough, because nothing should really be asleep because
		   of the brief netif_stop_queue. If this isn't true or if it
		   changes, use netif_wake_queue instead. */
	spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
	return 0;
}


static struct net_device_stats *clip_get_stats(struct net_device *dev)
{
	return &PRIV(dev)->stats;
}


int clip_mkip(struct atm_vcc *vcc,int timeout)
{
	struct clip_vcc *clip_vcc;
	struct sk_buff_head copy;
	struct sk_buff *skb;

	if (!vcc->push) return -EBADFD;
	clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
	if (!clip_vcc) return -ENOMEM;
	DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
	clip_vcc->vcc = vcc;
	vcc->user_back = clip_vcc;
	clip_vcc->entry = NULL;
	clip_vcc->xoff = 0;
	clip_vcc->encap = 1;
	clip_vcc->last_use = jiffies;
	clip_vcc->idle_timeout = timeout*HZ;
	clip_vcc->old_push = vcc->push;
	clip_vcc->old_pop = vcc->pop;
	vcc->push = clip_push;
	vcc->pop = clip_pop;
	skb_queue_head_init(&copy);
	skb_migrate(&vcc->recvq,&copy);
	/* re-process everything received between connection setup and MKIP */
	while ((skb = skb_dequeue(&copy)))
		if (!clip_devs) {
			atm_return(vcc,skb->truesize);
			kfree_skb(skb);
		}
		else {
			unsigned int len = skb->len;

			clip_push(vcc,skb);
			PRIV(skb->dev)->stats.rx_packets--;
			PRIV(skb->dev)->stats.rx_bytes -= len;
		}
	return 0;
}


int clip_setentry(struct atm_vcc *vcc,u32 ip)
{
	struct neighbour *neigh;
	struct atmarp_entry *entry;
	int error;
	struct clip_vcc *clip_vcc;
	struct rtable *rt;

	if (vcc->push != clip_push) {
		printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
		return -EBADF;
	}
	clip_vcc = CLIP_VCC(vcc);
	if (!ip) {
		if (!clip_vcc->entry) {
			printk(KERN_ERR "hiding hidden ATMARP entry\n");
			return 0;
		}
		DPRINTK("setentry: remove\n");
		unlink_clip_vcc(clip_vcc);
		return 0;
	}
	error = ip_route_output(&rt,ip,0,1,0);
	if (error) return error;
	neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
	ip_rt_put(rt);
	if (!neigh)
		return -ENOMEM;
	entry = NEIGH2ENTRY(neigh);
	if (entry != clip_vcc->entry) {
		if (!clip_vcc->entry) DPRINTK("setentry: add\n");
		else {
			DPRINTK("setentry: update\n");
			unlink_clip_vcc(clip_vcc);
		}
		link_vcc(clip_vcc,entry);
	}
	error = neigh_update(neigh,llc_oui,NUD_PERMANENT,1,0);
	neigh_release(neigh);
	return error;
}


static int clip_init(struct net_device *dev)
{
	DPRINTK("clip_init %s\n",dev->name);
	dev->hard_start_xmit = clip_start_xmit;
	/* sg_xmit ... */
	dev->hard_header = NULL;
	dev->rebuild_header = NULL;
	dev->set_mac_address = NULL;
	dev->hard_header_parse = NULL;
	dev->hard_header_cache = NULL;
	dev->header_cache_update = NULL;
	dev->change_mtu = NULL;
	dev->do_ioctl = NULL;
	dev->get_stats = clip_get_stats;
	dev->type = ARPHRD_ATM;
	dev->hard_header_len = RFC1483LLC_LEN;
	dev->mtu = RFC1626_MTU;
	dev->addr_len = 0;
	dev->tx_queue_len = 100; /* "normal" queue (packets) */
	    /* When using a "real" qdisc, the qdisc determines the queue */
	    /* length. tx_queue_len is only used for the default case, */
	    /* without any more elaborate queuing. 100 is a reasonable */
	    /* compromise between decent burst-tolerance and protection */
	    /* against memory hogs. */
	dev->flags = 0;
	return 0;
}


int clip_create(int number)
{
	struct net_device *dev;
	struct clip_priv *clip_priv;
	int error;

	if (number != -1) {
		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
			if (PRIV(dev)->number == number) return -EEXIST;
	}
	else {
		number = 0;
		for (dev = clip_devs; dev; dev = PRIV(dev)->next)
			if (PRIV(dev)->number >= number)
				number = PRIV(dev)->number+1;
	}
	dev = kmalloc(sizeof(struct net_device)+sizeof(struct clip_priv),
	    GFP_KERNEL); 
	if (!dev) return -ENOMEM;
	memset(dev,0,sizeof(struct net_device)+sizeof(struct clip_priv));
	clip_priv = PRIV(dev);
	sprintf(dev->name,"atm%d",number);
	dev->init = clip_init;
	spin_lock_init(&clip_priv->xoff_lock);
	clip_priv->number = number;
	error = register_netdev(dev);
	if (error) {
		kfree(dev);
		return error;
	}
	clip_priv->next = clip_devs;
	clip_devs = dev;
	DPRINTK("registered (net:%s)\n",dev->name);
	return number;
}


static int clip_device_event(struct notifier_block *this,unsigned long event,
    void *dev)
{
	/* ignore non-CLIP devices */
	if (((struct net_device *) dev)->type != ARPHRD_ATM ||
	    ((struct net_device *) dev)->init != clip_init)
		return NOTIFY_DONE;
	switch (event) {
		case NETDEV_UP:
			DPRINTK("clip_device_event NETDEV_UP\n");
			(void) to_atmarpd(act_up,PRIV(dev)->number,0);
			break;
		case NETDEV_GOING_DOWN:
			DPRINTK("clip_device_event NETDEV_DOWN\n");
			(void) to_atmarpd(act_down,PRIV(dev)->number,0);
			break;
		case NETDEV_CHANGE:
		case NETDEV_CHANGEMTU:
			DPRINTK("clip_device_event NETDEV_CHANGE*\n");
			(void) to_atmarpd(act_change,PRIV(dev)->number,0);
			break;
		case NETDEV_REBOOT:
		case NETDEV_REGISTER:
		case NETDEV_DOWN:
			DPRINTK("clip_device_event %ld\n",event);
			/* ignore */
			break;
		default:
			printk(KERN_WARNING "clip_device_event: unknown event "
			    "%ld\n",event);
			break;
	}
	return NOTIFY_DONE;
}


static int clip_inet_event(struct notifier_block *this,unsigned long event,
    void *ifa)
{
	struct in_device *in_dev;

	in_dev = ((struct in_ifaddr *) ifa)->ifa_dev;
	if (!in_dev || !in_dev->dev) {
		printk(KERN_WARNING "clip_inet_event: no device\n");
		return NOTIFY_DONE;
	}
	/*
	 * Transitions are of the down-change-up type, so it's sufficient to
	 * handle the change on up.
	 */
	if (event != NETDEV_UP) return NOTIFY_DONE;
	return clip_device_event(this,NETDEV_CHANGE,in_dev->dev);
}


static struct notifier_block clip_dev_notifier = {
	clip_device_event,
	NULL,
	0
};



static struct notifier_block clip_inet_notifier = {
	clip_inet_event,
	NULL,
	0
};



static void atmarpd_close(struct atm_vcc *vcc)
{
	DPRINTK("atmarpd_close\n");
	atmarpd = NULL; /* assumed to be atomic */
	barrier();
	unregister_inetaddr_notifier(&clip_inet_notifier);
	unregister_netdevice_notifier(&clip_dev_notifier);
	if (skb_peek(&vcc->recvq))
		printk(KERN_ERR "atmarpd_close: closing with requests "
		    "pending\n");
	skb_queue_purge(&vcc->recvq);
	DPRINTK("(done)\n");
}


static struct atmdev_ops atmarpd_dev_ops = {
	close:	atmarpd_close,
};


static struct atm_dev atmarpd_dev = {
	&atmarpd_dev_ops,
	NULL,		/* no PHY */
	"arpd",		/* type */
	999,		/* dummy device number */
	NULL,NULL,	/* pretend not to have any VCCs */
	NULL,NULL,	/* no data */
	{ 0 },		/* no flags */
	NULL,		/* no local address */
	{ 0 }		/* no ESI, no statistics */
};


int atm_init_atmarp(struct atm_vcc *vcc)
{
	struct net_device *dev;

	if (atmarpd) return -EADDRINUSE;
	if (start_timer) {
		start_timer = 0;
		init_timer(&idle_timer);
		idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
		idle_timer.function = idle_timer_check;
		add_timer(&idle_timer);
	}
	atmarpd = vcc;
	set_bit(ATM_VF_META,&vcc->flags);
	set_bit(ATM_VF_READY,&vcc->flags);
	    /* allow replies and avoid getting closed if signaling dies */
	bind_vcc(vcc,&atmarpd_dev);
	vcc->push = NULL;
	vcc->pop = NULL; /* crash */
	vcc->push_oam = NULL; /* crash */
	if (register_netdevice_notifier(&clip_dev_notifier))
		printk(KERN_ERR "register_netdevice_notifier failed\n");
	if (register_inetaddr_notifier(&clip_inet_notifier))
		printk(KERN_ERR "register_inetaddr_notifier failed\n");
	for (dev = clip_devs; dev; dev = PRIV(dev)->next)
		if (dev->flags & IFF_UP)
			(void) to_atmarpd(act_up,PRIV(dev)->number,0);
	return 0;
}


void atm_clip_init(void)
{
	clip_tbl.lock = RW_LOCK_UNLOCKED;
	clip_tbl.kmem_cachep = kmem_cache_create(clip_tbl.id,
	    clip_tbl.entry_size, 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
}