1 files changed, 795 insertions, 0 deletions

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
new file mode 100644
index 0000000..280de48
--- /dev/null
+++ b/net/atm/br2684.c
@@ -0,0 +1,795 @@
+/*
+ * Ethernet netdevice using ATM AAL5 as underlying carrier
+ * (RFC1483 obsoleted by RFC2684) for Linux
+ *
+ * Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
+ *          Eric Kinzie, 2006-2007, US Naval Research Laboratory
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/ip.h>
+#include <asm/uaccess.h>
+#include <net/arp.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/capability.h>
+#include <linux/seq_file.h>
+
+#include <linux/atmbr2684.h>
+
+#include "common.h"
+
+#ifdef SKB_DEBUG
+static void skb_debug(const struct sk_buff *skb)
+{
+#define NUM2PRINT 50
+	char buf[NUM2PRINT * 3 + 1];	/* 3 chars per byte */
+	int i = 0;
+	for (i = 0; i < skb->len && i < NUM2PRINT; i++) {
+		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
+	}
+	printk(KERN_DEBUG "br2684: skb: %s\n", buf);
+}
+#else
+#define skb_debug(skb)	do {} while (0)
+#endif
+
+#define BR2684_ETHERTYPE_LEN	2
+#define BR2684_PAD_LEN		2
+
+#define LLC		0xaa, 0xaa, 0x03
+#define SNAP_BRIDGED	0x00, 0x80, 0xc2
+#define SNAP_ROUTED	0x00, 0x00, 0x00
+#define PID_ETHERNET	0x00, 0x07
+#define ETHERTYPE_IPV4	0x08, 0x00
+#define ETHERTYPE_IPV6	0x86, 0xdd
+#define PAD_BRIDGED	0x00, 0x00
+
+static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 };
+static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 };
+static const unsigned char llc_oui_pid_pad[] =
+			{ LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
+static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
+static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
+
+enum br2684_encaps {
+	e_vc = BR2684_ENCAPS_VC,
+	e_llc = BR2684_ENCAPS_LLC,
+};
+
+struct br2684_vcc {
+	struct atm_vcc *atmvcc;
+	struct net_device *device;
+	/* keep old push, pop functions for chaining */
+	void (*old_push) (struct atm_vcc * vcc, struct sk_buff * skb);
+	/* void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb); */
+	enum br2684_encaps encaps;
+	struct list_head brvccs;
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	struct br2684_filter filter;
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+	unsigned copies_needed, copies_failed;
+};
+
+struct br2684_dev {
+	struct net_device *net_dev;
+	struct list_head br2684_devs;
+	int number;
+	struct list_head brvccs;	/* one device <=> one vcc (before xmas) */
+	struct net_device_stats stats;
+	int mac_was_set;
+	enum br2684_payload payload;
+};
+
+/*
+ * This lock should be held for writing any time the list of devices or
+ * their attached vcc's could be altered.  It should be held for reading
+ * any time these are being queried.  Note that we sometimes need to
+ * do read-locking under interrupt context, so write locking must block
+ * the current CPU's interrupts
+ */
+static DEFINE_RWLOCK(devs_lock);
+
+static LIST_HEAD(br2684_devs);
+
+static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
+{
+	return (struct br2684_dev *)net_dev->priv;
+}
+
+static inline struct net_device *list_entry_brdev(const struct list_head *le)
+{
+	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
+}
+
+static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
+{
+	return (struct br2684_vcc *)(atmvcc->user_back);
+}
+
+static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
+{
+	return list_entry(le, struct br2684_vcc, brvccs);
+}
+
+/* Caller should hold read_lock(&devs_lock) */
+static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
+{
+	struct list_head *lh;
+	struct net_device *net_dev;
+	switch (s->method) {
+	case BR2684_FIND_BYNUM:
+		list_for_each(lh, &br2684_devs) {
+			net_dev = list_entry_brdev(lh);
+			if (BRPRIV(net_dev)->number == s->spec.devnum)
+				return net_dev;
+		}
+		break;
+	case BR2684_FIND_BYIFNAME:
+		list_for_each(lh, &br2684_devs) {
+			net_dev = list_entry_brdev(lh);
+			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
+				return net_dev;
+		}
+		break;
+	}
+	return NULL;
+}
+
+/*
+ * Send a packet out a particular vcc.  Not to useful right now, but paves
+ * the way for multiple vcc's per itf.  Returns true if we can send,
+ * otherwise false
+ */
+static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
+			   struct br2684_vcc *brvcc)
+{
+	struct atm_vcc *atmvcc;
+	int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
+
+	if (skb_headroom(skb) < minheadroom) {
+		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
+		brvcc->copies_needed++;
+		dev_kfree_skb(skb);
+		if (skb2 == NULL) {
+			brvcc->copies_failed++;
+			return 0;
+		}
+		skb = skb2;
+	}
+
+	if (brvcc->encaps == e_llc) {
+		if (brdev->payload == p_bridged) {
+			skb_push(skb, sizeof(llc_oui_pid_pad));
+			skb_copy_to_linear_data(skb, llc_oui_pid_pad,
+						sizeof(llc_oui_pid_pad));
+		} else if (brdev->payload == p_routed) {
+			unsigned short prot = ntohs(skb->protocol);
+
+			skb_push(skb, sizeof(llc_oui_ipv4));
+			switch (prot) {
+			case ETH_P_IP:
+				skb_copy_to_linear_data(skb, llc_oui_ipv4,
+							sizeof(llc_oui_ipv4));
+				break;
+			case ETH_P_IPV6:
+				skb_copy_to_linear_data(skb, llc_oui_ipv6,
+							sizeof(llc_oui_ipv6));
+				break;
+			default:
+				dev_kfree_skb(skb);
+				return 0;
+			}
+		}
+	} else { /* e_vc */
+		if (brdev->payload == p_bridged) {
+			skb_push(skb, 2);
+			memset(skb->data, 0, 2);
+		} else { /* p_routed */
+			skb_pull(skb, ETH_HLEN);
+		}
+	}
+	skb_debug(skb);
+
+	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
+	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
+	if (!atm_may_send(atmvcc, skb->truesize)) {
+		/*
+		 * We free this here for now, because we cannot know in a higher
+		 * layer whether the skb pointer it supplied wasn't freed yet.
+		 * Now, it always is.
+		 */
+		dev_kfree_skb(skb);
+		return 0;
+	}
+	atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
+	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
+	brdev->stats.tx_packets++;
+	brdev->stats.tx_bytes += skb->len;
+	atmvcc->send(atmvcc, skb);
+	return 1;
+}
+
+static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
+						   const struct br2684_dev *brdev)
+{
+	return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next);	/* 1 vcc/dev right now */
+}
+
+static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct br2684_dev *brdev = BRPRIV(dev);
+	struct br2684_vcc *brvcc;
+
+	pr_debug("br2684_start_xmit, skb->dst=%p\n", skb->dst);
+	read_lock(&devs_lock);
+	brvcc = pick_outgoing_vcc(skb, brdev);
+	if (brvcc == NULL) {
+		pr_debug("no vcc attached to dev %s\n", dev->name);
+		brdev->stats.tx_errors++;
+		brdev->stats.tx_carrier_errors++;
+		/* netif_stop_queue(dev); */
+		dev_kfree_skb(skb);
+		read_unlock(&devs_lock);
+		return 0;
+	}
+	if (!br2684_xmit_vcc(skb, brdev, brvcc)) {
+		/*
+		 * We should probably use netif_*_queue() here, but that
+		 * involves added complication.  We need to walk before
+		 * we can run.
+		 *
+		 * Don't free here! this pointer might be no longer valid!
+		 */
+		brdev->stats.tx_errors++;
+		brdev->stats.tx_fifo_errors++;
+	}
+	read_unlock(&devs_lock);
+	return 0;
+}
+
+static struct net_device_stats *br2684_get_stats(struct net_device *dev)
+{
+	pr_debug("br2684_get_stats\n");
+	return &BRPRIV(dev)->stats;
+}
+
+/*
+ * We remember when the MAC gets set, so we don't override it later with
+ * the ESI of the ATM card of the first VC
+ */
+static int (*my_eth_mac_addr) (struct net_device *, void *);
+static int br2684_mac_addr(struct net_device *dev, void *p)
+{
+	int err = my_eth_mac_addr(dev, p);
+	if (!err)
+		BRPRIV(dev)->mac_was_set = 1;
+	return err;
+}
+
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+/* this IOCTL is experimental. */
+static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg)
+{
+	struct br2684_vcc *brvcc;
+	struct br2684_filter_set fs;
+
+	if (copy_from_user(&fs, arg, sizeof fs))
+		return -EFAULT;
+	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
+		/*
+		 * This is really a per-vcc thing, but we can also search
+		 * by device.
+		 */
+		struct br2684_dev *brdev;
+		read_lock(&devs_lock);
+		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
+		if (brdev == NULL || list_empty(&brdev->brvccs) || brdev->brvccs.next != brdev->brvccs.prev)	/* >1 VCC */
+			brvcc = NULL;
+		else
+			brvcc = list_entry_brvcc(brdev->brvccs.next);
+		read_unlock(&devs_lock);
+		if (brvcc == NULL)
+			return -ESRCH;
+	} else
+		brvcc = BR2684_VCC(atmvcc);
+	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
+	return 0;
+}
+
+/* Returns 1 if packet should be dropped */
+static inline int
+packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
+{
+	if (brvcc->filter.netmask == 0)
+		return 0;	/* no filter in place */
+	if (type == htons(ETH_P_IP) &&
+	    (((struct iphdr *)(skb->data))->daddr & brvcc->filter.
+	     netmask) == brvcc->filter.prefix)
+		return 0;
+	if (type == htons(ETH_P_ARP))
+		return 0;
+	/*
+	 * TODO: we should probably filter ARPs too.. don't want to have
+	 * them returning values that don't make sense, or is that ok?
+	 */
+	return 1;		/* drop */
+}
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+
+static void br2684_close_vcc(struct br2684_vcc *brvcc)
+{
+	pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
+	write_lock_irq(&devs_lock);
+	list_del(&brvcc->brvccs);
+	write_unlock_irq(&devs_lock);
+	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
+	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
+	kfree(brvcc);
+	module_put(THIS_MODULE);
+}
+
+/* when AAL5 PDU comes in: */
+static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
+{
+	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
+	struct net_device *net_dev = brvcc->device;
+	struct br2684_dev *brdev = BRPRIV(net_dev);
+
+	pr_debug("br2684_push\n");
+
+	if (unlikely(skb == NULL)) {
+		/* skb==NULL means VCC is being destroyed */
+		br2684_close_vcc(brvcc);
+		if (list_empty(&brdev->brvccs)) {
+			write_lock_irq(&devs_lock);
+			list_del(&brdev->br2684_devs);
+			write_unlock_irq(&devs_lock);
+			unregister_netdev(net_dev);
+			free_netdev(net_dev);
+		}
+		return;
+	}
+
+	skb_debug(skb);
+	atm_return(atmvcc, skb->truesize);
+	pr_debug("skb from brdev %p\n", brdev);
+	if (brvcc->encaps == e_llc) {
+
+		if (skb->len > 7 && skb->data[7] == 0x01)
+			__skb_trim(skb, skb->len - 4);
+
+		/* accept packets that have "ipv[46]" in the snap header */
+		if ((skb->len >= (sizeof(llc_oui_ipv4)))
+		    &&
+		    (memcmp
+		     (skb->data, llc_oui_ipv4,
+		      sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
+			if (memcmp
+			    (skb->data + 6, ethertype_ipv6,
+			     sizeof(ethertype_ipv6)) == 0)
+				skb->protocol = htons(ETH_P_IPV6);
+			else if (memcmp
+				 (skb->data + 6, ethertype_ipv4,
+				  sizeof(ethertype_ipv4)) == 0)
+				skb->protocol = htons(ETH_P_IP);
+			else
+				goto error;
+			skb_pull(skb, sizeof(llc_oui_ipv4));
+			skb_reset_network_header(skb);
+			skb->pkt_type = PACKET_HOST;
+			/*
+			 * Let us waste some time for checking the encapsulation.
+			 * Note, that only 7 char is checked so frames with a valid FCS
+			 * are also accepted (but FCS is not checked of course).
+			 */
+		} else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
+			   (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
+			skb_pull(skb, sizeof(llc_oui_pid_pad));
+			skb->protocol = eth_type_trans(skb, net_dev);
+		} else
+			goto error;
+
+	} else { /* e_vc */
+		if (brdev->payload == p_routed) {
+			struct iphdr *iph;
+
+			skb_reset_network_header(skb);
+			iph = ip_hdr(skb);
+			if (iph->version == 4)
+				skb->protocol = htons(ETH_P_IP);
+			else if (iph->version == 6)
+				skb->protocol = htons(ETH_P_IPV6);
+			else
+				goto error;
+			skb->pkt_type = PACKET_HOST;
+		} else { /* p_bridged */
+			/* first 2 chars should be 0 */
+			if (*((u16 *) (skb->data)) != 0)
+				goto error;
+			skb_pull(skb, BR2684_PAD_LEN);
+			skb->protocol = eth_type_trans(skb, net_dev);
+		}
+	}
+
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb)))
+		goto dropped;
+#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);
+	/* sigh, interface is down? */
+	if (unlikely(!(net_dev->flags & IFF_UP)))
+		goto dropped;
+	brdev->stats.rx_packets++;
+	brdev->stats.rx_bytes += skb->len;
+	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
+	netif_rx(skb);
+	return;
+
+dropped:
+	brdev->stats.rx_dropped++;
+	goto free_skb;
+error:
+	brdev->stats.rx_errors++;
+free_skb:
+	dev_kfree_skb(skb);
+	return;
+}
+
+/*
+ * Assign a vcc to a dev
+ * Note: we do not have explicit unassign, but look at _push()
+ */
+static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
+{
+	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;
+		br2684_push(atmvcc, skb);
+		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
+		BRPRIV(skb->dev)->stats.rx_packets--;
+
+		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 void br2684_setup_routed(struct net_device *netdev)
+{
+	struct br2684_dev *brdev = BRPRIV(netdev);
+	brdev->net_dev = netdev;
+
+	netdev->hard_header_len = 0;
+	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;
+	netdev->addr_len = 0;
+	netdev->mtu = 1500;
+	netdev->type = ARPHRD_PPP;
+	netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+	netdev->tx_queue_len = 100;
+	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;
+	enum br2684_payload payload;
+
+	pr_debug("br2684_create\n");
+
+	if (copy_from_user(&ni, arg, sizeof ni)) {
+		return -EFAULT;
+	}
+
+	if (ni.media & BR2684_FLAG_ROUTED)
+		payload = p_routed;
+	else
+		payload = p_bridged;
+	ni.media &= 0xffff;	/* strip flags */
+
+	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",
+			      (payload == p_routed) ?
+			      br2684_setup_routed : 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->payload = payload;
+	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;
+	atm_backend_t b;
+
+	int err;
+	switch (cmd) {
+	case ATM_SETBACKEND:
+	case ATM_NEWBACKENDIF:
+		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)
+	__acquires(devs_lock)
+{
+	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)
+	__releases(devs_lock)
+{
+	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 payload=%s"
+			   ", failed copies %u/%u"
+			   "\n", brvcc->atmvcc->dev->number,
+			   brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
+			   (brvcc->encaps == e_llc) ? "LLC" : "VC",
+			   (brdev->payload == p_bridged) ? "bridged" : "routed",
+			   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 /* CONFIG_PROC_FS */
+
+static int __init br2684_init(void)
+{
+#ifdef CONFIG_PROC_FS
+	struct proc_dir_entry *p;
+	p = proc_create("br2684", 0, atm_proc_root, &br2684_proc_ops);
+	if (p == NULL)
+		return -ENOMEM;
+#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");