br2684.c

linux 内核源代码

		return;
	}

	skb_pull(skb, plen - ETH_HLEN);
	skb->protocol = eth_type_trans(skb, net_dev);
#ifdef CONFIG_ATM_BR2684_IPFILTER
	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) {
		brdev->stats.rx_dropped++;
		dev_kfree_skb(skb);
		return;
	}
#endif /* CONFIG_ATM_BR2684_IPFILTER */
	skb->dev = net_dev;
	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
	pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
	skb_debug(skb);
	if (unlikely(!(net_dev->flags & IFF_UP))) {
		/* sigh, interface is down */
		brdev->stats.rx_dropped++;
		dev_kfree_skb(skb);
		return;
	}
	brdev->stats.rx_packets++;
	brdev->stats.rx_bytes += skb->len;
	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
	netif_rx(skb);
}

static int br2684_regvcc(struct atm_vcc *atmvcc, void __user *arg)
{
/* assign a vcc to a dev
Note: we do not have explicit unassign, but look at _push()
*/
	int err;
	struct br2684_vcc *brvcc;
	struct sk_buff *skb;
	struct sk_buff_head *rq;
	struct br2684_dev *brdev;
	struct net_device *net_dev;
	struct atm_backend_br2684 be;
	unsigned long flags;

	if (copy_from_user(&be, arg, sizeof be))
		return -EFAULT;
	brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
	if (!brvcc)
		return -ENOMEM;
	write_lock_irq(&devs_lock);
	net_dev = br2684_find_dev(&be.ifspec);
	if (net_dev == NULL) {
		printk(KERN_ERR
		    "br2684: tried to attach to non-existant device\n");
		err = -ENXIO;
		goto error;
	}
	brdev = BRPRIV(net_dev);
	if (atmvcc->push == NULL) {
		err = -EBADFD;
		goto error;
	}
	if (!list_empty(&brdev->brvccs)) {
		/* Only 1 VCC/dev right now */
		err = -EEXIST;
		goto error;
	}
	if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO ||
	    be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps !=
	    BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) ||
	    be.min_size != 0) {
		err = -EINVAL;
		goto error;
	}
	pr_debug("br2684_regvcc vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps,
		brvcc);
	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
		unsigned char *esi = atmvcc->dev->esi;
		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
			memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
		else
			net_dev->dev_addr[2] = 1;
	}
	list_add(&brvcc->brvccs, &brdev->brvccs);
	write_unlock_irq(&devs_lock);
	brvcc->device = net_dev;
	brvcc->atmvcc = atmvcc;
	atmvcc->user_back = brvcc;
	brvcc->encaps = (enum br2684_encaps) be.encaps;
	brvcc->old_push = atmvcc->push;
	barrier();
	atmvcc->push = br2684_push;

	rq = &sk_atm(atmvcc)->sk_receive_queue;

	spin_lock_irqsave(&rq->lock, flags);
	if (skb_queue_empty(rq)) {
		skb = NULL;
	} else {
		/* NULL terminate the list.  */
		rq->prev->next = NULL;
		skb = rq->next;
	}
	rq->prev = rq->next = (struct sk_buff *)rq;
	rq->qlen = 0;
	spin_unlock_irqrestore(&rq->lock, flags);

	while (skb) {
		struct sk_buff *next = skb->next;

		skb->next = skb->prev = NULL;
		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
		BRPRIV(skb->dev)->stats.rx_packets--;
		br2684_push(atmvcc, skb);

		skb = next;
	}
	__module_get(THIS_MODULE);
	return 0;
    error:
	write_unlock_irq(&devs_lock);
	kfree(brvcc);
	return err;
}

static void br2684_setup(struct net_device *netdev)
{
	struct br2684_dev *brdev = BRPRIV(netdev);

	ether_setup(netdev);
	brdev->net_dev = netdev;

	my_eth_mac_addr = netdev->set_mac_address;
	netdev->set_mac_address = br2684_mac_addr;
	netdev->hard_start_xmit = br2684_start_xmit;
	netdev->get_stats = br2684_get_stats;

	INIT_LIST_HEAD(&brdev->brvccs);
}

static int br2684_create(void __user *arg)
{
	int err;
	struct net_device *netdev;
	struct br2684_dev *brdev;
	struct atm_newif_br2684 ni;

	pr_debug("br2684_create\n");

	if (copy_from_user(&ni, arg, sizeof ni)) {
		return -EFAULT;
	}
	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
		return -EINVAL;
	}

	netdev = alloc_netdev(sizeof(struct br2684_dev),
			      ni.ifname[0] ? ni.ifname : "nas%d",
			      br2684_setup);
	if (!netdev)
		return -ENOMEM;

	brdev = BRPRIV(netdev);

	pr_debug("registered netdev %s\n", netdev->name);
	/* open, stop, do_ioctl ? */
	err = register_netdev(netdev);
	if (err < 0) {
		printk(KERN_ERR "br2684_create: register_netdev failed\n");
		free_netdev(netdev);
		return err;
	}

	write_lock_irq(&devs_lock);
	brdev->number = list_empty(&br2684_devs) ? 1 :
	    BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
	list_add_tail(&brdev->br2684_devs, &br2684_devs);
	write_unlock_irq(&devs_lock);
	return 0;
}

/*
 * This handles ioctls actually performed on our vcc - we must return
 * -ENOIOCTLCMD for any unrecognized ioctl
 */
static int br2684_ioctl(struct socket *sock, unsigned int cmd,
	unsigned long arg)
{
	struct atm_vcc *atmvcc = ATM_SD(sock);
	void __user *argp = (void __user *)arg;

	int err;
	switch(cmd) {
	case ATM_SETBACKEND:
	case ATM_NEWBACKENDIF: {
		atm_backend_t b;
		err = get_user(b, (atm_backend_t __user *) argp);
		if (err)
			return -EFAULT;
		if (b != ATM_BACKEND_BR2684)
			return -ENOIOCTLCMD;
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (cmd == ATM_SETBACKEND)
			return br2684_regvcc(atmvcc, argp);
		else
			return br2684_create(argp);
		}
#ifdef CONFIG_ATM_BR2684_IPFILTER
	case BR2684_SETFILT:
		if (atmvcc->push != br2684_push)
			return -ENOIOCTLCMD;
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		err = br2684_setfilt(atmvcc, argp);
		return err;
#endif /* CONFIG_ATM_BR2684_IPFILTER */
	}
	return -ENOIOCTLCMD;
}

static struct atm_ioctl br2684_ioctl_ops = {
	.owner	= THIS_MODULE,
	.ioctl	= br2684_ioctl,
};


#ifdef CONFIG_PROC_FS
static void *br2684_seq_start(struct seq_file *seq, loff_t *pos)
{
	read_lock(&devs_lock);
	return seq_list_start(&br2684_devs, *pos);
}

static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	return seq_list_next(v, &br2684_devs, pos);
}

static void br2684_seq_stop(struct seq_file *seq, void *v)
{
	read_unlock(&devs_lock);
}

static int br2684_seq_show(struct seq_file *seq, void *v)
{
	const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
			br2684_devs);
	const struct net_device *net_dev = brdev->net_dev;
	const struct br2684_vcc *brvcc;
	DECLARE_MAC_BUF(mac);

	seq_printf(seq, "dev %.16s: num=%d, mac=%s (%s)\n",
		   net_dev->name,
		   brdev->number,
		   print_mac(mac, net_dev->dev_addr),
		   brdev->mac_was_set ? "set" : "auto");

	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s"
				    ", failed copies %u/%u"
				    "\n", brvcc->atmvcc->dev->number,
				    brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
				    (brvcc->encaps == e_llc) ? "LLC" : "VC"
				    , brvcc->copies_failed
				    , brvcc->copies_needed
				    );
#ifdef CONFIG_ATM_BR2684_IPFILTER
#define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
#define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
			if (brvcc->filter.netmask != 0)
				seq_printf(seq, "    filter=%d.%d.%d.%d/"
						"%d.%d.%d.%d\n",
						bs(prefix), bs(netmask));
#undef bs
#undef b1
#endif /* CONFIG_ATM_BR2684_IPFILTER */
	}
	return 0;
}

static const struct seq_operations br2684_seq_ops = {
	.start = br2684_seq_start,
	.next  = br2684_seq_next,
	.stop  = br2684_seq_stop,
	.show  = br2684_seq_show,
};

static int br2684_proc_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &br2684_seq_ops);
}

static const struct file_operations br2684_proc_ops = {
	.owner   = THIS_MODULE,
	.open    = br2684_proc_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release,
};

extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
#endif

static int __init br2684_init(void)
{
#ifdef CONFIG_PROC_FS
	struct proc_dir_entry *p;
	if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
		return -ENOMEM;
	p->proc_fops = &br2684_proc_ops;
#endif
	register_atm_ioctl(&br2684_ioctl_ops);
	return 0;
}

static void __exit br2684_exit(void)
{
	struct net_device *net_dev;
	struct br2684_dev *brdev;
	struct br2684_vcc *brvcc;
	deregister_atm_ioctl(&br2684_ioctl_ops);

#ifdef CONFIG_PROC_FS
	remove_proc_entry("br2684", atm_proc_root);
#endif

	while (!list_empty(&br2684_devs)) {
		net_dev = list_entry_brdev(br2684_devs.next);
		brdev = BRPRIV(net_dev);
		while (!list_empty(&brdev->brvccs)) {
			brvcc = list_entry_brvcc(brdev->brvccs.next);
			br2684_close_vcc(brvcc);
		}

		list_del(&brdev->br2684_devs);
		unregister_netdev(net_dev);
		free_netdev(net_dev);
	}
}

module_init(br2684_init);
module_exit(br2684_exit);

MODULE_AUTHOR("Marcell GAL");
MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
MODULE_LICENSE("GPL");