6lowpan: move 6lowpan.c to 6lowpan_rtnl.c

We have a 6lowpan.c file and 6lowpan.ko file. To avoid confusing we
should move 6lowpan.c to 6lowpan_rtnl.c. Then we can support multiple
source files for 6lowpan module.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 832 insertions, 0 deletions

diff --git a/net/ieee802154/6lowpan_rtnl.c b/net/ieee802154/6lowpan_rtnl.c
new file mode 100644
index 000000000000..6b7d17fd5481
--- /dev/null
+++ b/net/ieee802154/6lowpan_rtnl.c
@@ -0,0 +1,832 @@
+/*
+ * Copyright 2011, Siemens AG
+ * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+/*
+ * Based on patches from Jon Smirl <jonsmirl@gmail.com>
+ * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* Jon's code is based on 6lowpan implementation for Contiki which is:
+ * Copyright (c) 2008, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <linux/bitops.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/netdevice.h>
+#include <net/af_ieee802154.h>
+#include <net/ieee802154.h>
+#include <net/ieee802154_netdev.h>
+#include <net/ipv6.h>
+
+#include "6lowpan.h"
+
+static LIST_HEAD(lowpan_devices);
+
+/* private device info */
+struct lowpan_dev_info {
+	struct net_device	*real_dev; /* real WPAN device ptr */
+	struct mutex		dev_list_mtx; /* mutex for list ops */
+	__be16			fragment_tag;
+};
+
+struct lowpan_dev_record {
+	struct net_device *ldev;
+	struct list_head list;
+};
+
+struct lowpan_fragment {
+	struct sk_buff		*skb;		/* skb to be assembled */
+	u16			length;		/* length to be assemled */
+	u32			bytes_rcv;	/* bytes received */
+	u16			tag;		/* current fragment tag */
+	struct timer_list	timer;		/* assembling timer */
+	struct list_head	list;		/* fragments list */
+};
+
+static LIST_HEAD(lowpan_fragments);
+static DEFINE_SPINLOCK(flist_lock);
+
+static inline struct
+lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
+{
+	return netdev_priv(dev);
+}
+
+static inline void lowpan_address_flip(u8 *src, u8 *dest)
+{
+	int i;
+	for (i = 0; i < IEEE802154_ADDR_LEN; i++)
+		(dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
+}
+
+static int lowpan_header_create(struct sk_buff *skb,
+			   struct net_device *dev,
+			   unsigned short type, const void *_daddr,
+			   const void *_saddr, unsigned int len)
+{
+	const u8 *saddr = _saddr;
+	const u8 *daddr = _daddr;
+	struct ieee802154_addr sa, da;
+
+	/* TODO:
+	 * if this package isn't ipv6 one, where should it be routed?
+	 */
+	if (type != ETH_P_IPV6)
+		return 0;
+
+	if (!saddr)
+		saddr = dev->dev_addr;
+
+	raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
+	raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
+
+	lowpan_header_compress(skb, dev, type, daddr, saddr, len);
+
+	/*
+	 * NOTE1: I'm still unsure about the fact that compression and WPAN
+	 * header are created here and not later in the xmit. So wait for
+	 * an opinion of net maintainers.
+	 */
+	/*
+	 * NOTE2: to be absolutely correct, we must derive PANid information
+	 * from MAC subif of the 'dev' and 'real_dev' network devices, but
+	 * this isn't implemented in mainline yet, so currently we assign 0xff
+	 */
+	mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+	mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
+
+	/* prepare wpan address data */
+	sa.addr_type = IEEE802154_ADDR_LONG;
+	sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
+
+	memcpy(&(sa.hwaddr), saddr, 8);
+	/* intra-PAN communications */
+	da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
+
+	/*
+	 * if the destination address is the broadcast address, use the
+	 * corresponding short address
+	 */
+	if (lowpan_is_addr_broadcast(daddr)) {
+		da.addr_type = IEEE802154_ADDR_SHORT;
+		da.short_addr = IEEE802154_ADDR_BROADCAST;
+	} else {
+		da.addr_type = IEEE802154_ADDR_LONG;
+		memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
+
+		/* request acknowledgment */
+		mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
+	}
+
+	return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
+			type, (void *)&da, (void *)&sa, skb->len);
+}
+
+static int lowpan_give_skb_to_devices(struct sk_buff *skb,
+					struct net_device *dev)
+{
+	struct lowpan_dev_record *entry;
+	struct sk_buff *skb_cp;
+	int stat = NET_RX_SUCCESS;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, &lowpan_devices, list)
+		if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
+			skb_cp = skb_copy(skb, GFP_ATOMIC);
+			if (!skb_cp) {
+				stat = -ENOMEM;
+				break;
+			}
+
+			skb_cp->dev = entry->ldev;
+			stat = netif_rx(skb_cp);
+		}
+	rcu_read_unlock();
+
+	return stat;
+}
+
+static void lowpan_fragment_timer_expired(unsigned long entry_addr)
+{
+	struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
+
+	pr_debug("timer expired for frame with tag %d\n", entry->tag);
+
+	list_del(&entry->list);
+	dev_kfree_skb(entry->skb);
+	kfree(entry);
+}
+
+static struct lowpan_fragment *
+lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
+{
+	struct lowpan_fragment *frame;
+
+	frame = kzalloc(sizeof(struct lowpan_fragment),
+			GFP_ATOMIC);
+	if (!frame)
+		goto frame_err;
+
+	INIT_LIST_HEAD(&frame->list);
+
+	frame->length = len;
+	frame->tag = tag;
+
+	/* allocate buffer for frame assembling */
+	frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
+					       sizeof(struct ipv6hdr));
+
+	if (!frame->skb)
+		goto skb_err;
+
+	frame->skb->priority = skb->priority;
+
+	/* reserve headroom for uncompressed ipv6 header */
+	skb_reserve(frame->skb, sizeof(struct ipv6hdr));
+	skb_put(frame->skb, frame->length);
+
+	/* copy the first control block to keep a
+	 * trace of the link-layer addresses in case
+	 * of a link-local compressed address
+	 */
+	memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb));
+
+	init_timer(&frame->timer);
+	/* time out is the same as for ipv6 - 60 sec */
+	frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
+	frame->timer.data = (unsigned long)frame;
+	frame->timer.function = lowpan_fragment_timer_expired;
+
+	add_timer(&frame->timer);
+
+	list_add_tail(&frame->list, &lowpan_fragments);
+
+	return frame;
+
+skb_err:
+	kfree(frame);
+frame_err:
+	return NULL;
+}
+
+static int process_data(struct sk_buff *skb)
+{
+	u8 iphc0, iphc1;
+	const struct ieee802154_addr *_saddr, *_daddr;
+
+	raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len);
+	/* at least two bytes will be used for the encoding */
+	if (skb->len < 2)
+		goto drop;
+
+	if (lowpan_fetch_skb_u8(skb, &iphc0))
+		goto drop;
+
+	/* fragments assembling */
+	switch (iphc0 & LOWPAN_DISPATCH_MASK) {
+	case LOWPAN_DISPATCH_FRAG1:
+	case LOWPAN_DISPATCH_FRAGN:
+	{
+		struct lowpan_fragment *frame;
+		/* slen stores the rightmost 8 bits of the 11 bits length */
+		u8 slen, offset = 0;
+		u16 len, tag;
+		bool found = false;
+
+		if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
+		    lowpan_fetch_skb_u16(skb, &tag))  /* fragment tag */
+			goto drop;
+
+		/* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
+		len = ((iphc0 & 7) << 8) | slen;
+
+		if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
+			pr_debug("%s received a FRAG1 packet (tag: %d, "
+				 "size of the entire IP packet: %d)",
+				 __func__, tag, len);
+		} else { /* FRAGN */
+			if (lowpan_fetch_skb_u8(skb, &offset))
+				goto unlock_and_drop;
+			pr_debug("%s received a FRAGN packet (tag: %d, "
+				 "size of the entire IP packet: %d, "
+				 "offset: %d)", __func__, tag, len, offset * 8);
+		}
+
+		/*
+		 * check if frame assembling with the same tag is
+		 * already in progress
+		 */
+		spin_lock_bh(&flist_lock);
+
+		list_for_each_entry(frame, &lowpan_fragments, list)
+			if (frame->tag == tag) {
+				found = true;
+				break;
+			}
+
+		/* alloc new frame structure */
+		if (!found) {
+			pr_debug("%s first fragment received for tag %d, "
+				 "begin packet reassembly", __func__, tag);
+			frame = lowpan_alloc_new_frame(skb, len, tag);
+			if (!frame)
+				goto unlock_and_drop;
+		}
+
+		/* if payload fits buffer, copy it */
+		if (likely((offset * 8 + skb->len) <= frame->length))
+			skb_copy_to_linear_data_offset(frame->skb, offset * 8,
+							skb->data, skb->len);
+		else
+			goto unlock_and_drop;
+
+		frame->bytes_rcv += skb->len;
+
+		/* frame assembling complete */
+		if ((frame->bytes_rcv == frame->length) &&
+		     frame->timer.expires > jiffies) {
+			/* if timer haven't expired - first of all delete it */
+			del_timer_sync(&frame->timer);
+			list_del(&frame->list);
+			spin_unlock_bh(&flist_lock);
+
+			pr_debug("%s successfully reassembled fragment "
+				 "(tag %d)", __func__, tag);
+
+			dev_kfree_skb(skb);
+			skb = frame->skb;
+			kfree(frame);
+
+			if (lowpan_fetch_skb_u8(skb, &iphc0))
+				goto drop;
+
+			break;
+		}
+		spin_unlock_bh(&flist_lock);
+
+		return kfree_skb(skb), 0;
+	}
+	default:
+		break;
+	}
+
+	if (lowpan_fetch_skb_u8(skb, &iphc1))
+		goto drop;
+
+	_saddr = &mac_cb(skb)->sa;
+	_daddr = &mac_cb(skb)->da;
+
+	return lowpan_process_data(skb, skb->dev, (u8 *)_saddr->hwaddr,
+				_saddr->addr_type, IEEE802154_ADDR_LEN,
+				(u8 *)_daddr->hwaddr, _daddr->addr_type,
+				IEEE802154_ADDR_LEN, iphc0, iphc1,
+				lowpan_give_skb_to_devices);
+
+unlock_and_drop:
+	spin_unlock_bh(&flist_lock);
+drop:
+	kfree_skb(skb);
+	return -EINVAL;
+}
+
+static int lowpan_set_address(struct net_device *dev, void *p)
+{
+	struct sockaddr *sa = p;
+
+	if (netif_running(dev))
+		return -EBUSY;
+
+	/* TODO: validate addr */
+	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
+
+	return 0;
+}
+
+static int
+lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
+			int mlen, int plen, int offset, int type)
+{
+	struct sk_buff *frag;
+	int hlen;
+
+	hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
+			LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
+
+	raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
+
+	frag = netdev_alloc_skb(skb->dev,
+				hlen + mlen + plen + IEEE802154_MFR_SIZE);
+	if (!frag)
+		return -ENOMEM;
+
+	frag->priority = skb->priority;
+
+	/* copy header, MFR and payload */
+	skb_put(frag, mlen);
+	skb_copy_to_linear_data(frag, skb_mac_header(skb), mlen);
+
+	skb_put(frag, hlen);
+	skb_copy_to_linear_data_offset(frag, mlen, head, hlen);
+
+	skb_put(frag, plen);
+	skb_copy_to_linear_data_offset(frag, mlen + hlen,
+				       skb_network_header(skb) + offset, plen);
+
+	raw_dump_table(__func__, " raw fragment dump", frag->data, frag->len);
+
+	return dev_queue_xmit(frag);
+}
+
+static int
+lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
+{
+	int err;
+	u16 dgram_offset, dgram_size, payload_length, header_length,
+	    lowpan_size, frag_plen, offset;
+	__be16 tag;
+	u8 head[5];
+
+	header_length = skb->mac_len;
+	payload_length = skb->len - header_length;
+	tag = lowpan_dev_info(dev)->fragment_tag++;
+	lowpan_size = skb_network_header_len(skb);
+	dgram_size = lowpan_uncompress_size(skb, &dgram_offset) -
+		     header_length;
+
+	/* first fragment header */
+	head[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x7);
+	head[1] = dgram_size & 0xff;
+	head[2] = tag >> 8;
+	head[3] = tag & 0xff;
+
+	/* calc the nearest payload length(divided to 8) for first fragment
+	 * which fits into a IEEE802154_MTU
+	 */
+	frag_plen = round_down(IEEE802154_MTU - header_length -
+			       LOWPAN_FRAG1_HEAD_SIZE - lowpan_size -
+			       IEEE802154_MFR_SIZE, 8);
+
+	err = lowpan_fragment_xmit(skb, head, header_length,
+				   frag_plen + lowpan_size, 0,
+				   LOWPAN_DISPATCH_FRAG1);
+	if (err) {
+		pr_debug("%s unable to send FRAG1 packet (tag: %d)",
+			 __func__, tag);
+		goto exit;
+	}
+
+	offset = lowpan_size + frag_plen;
+	dgram_offset += frag_plen;
+
+	/* next fragment header */
+	head[0] &= ~LOWPAN_DISPATCH_FRAG1;
+	head[0] |= LOWPAN_DISPATCH_FRAGN;
+
+	frag_plen = round_down(IEEE802154_MTU - header_length -
+			       LOWPAN_FRAGN_HEAD_SIZE - IEEE802154_MFR_SIZE, 8);
+
+	while (payload_length - offset > 0) {
+		int len = frag_plen;
+
+		head[4] = dgram_offset >> 3;
+
+		if (payload_length - offset < len)
+			len = payload_length - offset;
+
+		err = lowpan_fragment_xmit(skb, head, header_length, len,
+					   offset, LOWPAN_DISPATCH_FRAGN);
+		if (err) {
+			pr_debug("%s unable to send a subsequent FRAGN packet "
+				 "(tag: %d, offset: %d", __func__, tag, offset);
+			goto exit;
+		}
+
+		offset += len;
+		dgram_offset += len;
+	}
+
+exit:
+	return err;
+}
+
+static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	int err = -1;
+
+	pr_debug("package xmit\n");
+
+	skb->dev = lowpan_dev_info(dev)->real_dev;
+	if (skb->dev == NULL) {
+		pr_debug("ERROR: no real wpan device found\n");
+		goto error;
+	}
+
+	/* Send directly if less than the MTU minus the 2 checksum bytes. */
+	if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
+		err = dev_queue_xmit(skb);
+		goto out;
+	}
+
+	pr_debug("frame is too big, fragmentation is needed\n");
+	err = lowpan_skb_fragmentation(skb, dev);
+error:
+	dev_kfree_skb(skb);
+out:
+	if (err)
+		pr_debug("ERROR: xmit failed\n");
+
+	return (err < 0) ? NET_XMIT_DROP : err;
+}
+
+static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
+{
+	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
+	return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
+}
+
+static u16 lowpan_get_pan_id(const struct net_device *dev)
+{
+	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
+	return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
+}
+
+static u16 lowpan_get_short_addr(const struct net_device *dev)
+{
+	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
+	return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
+}
+
+static u8 lowpan_get_dsn(const struct net_device *dev)
+{
+	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
+	return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
+}
+
+static struct header_ops lowpan_header_ops = {
+	.create	= lowpan_header_create,
+};
+
+static struct lock_class_key lowpan_tx_busylock;
+static struct lock_class_key lowpan_netdev_xmit_lock_key;
+
+static void lowpan_set_lockdep_class_one(struct net_device *dev,
+					 struct netdev_queue *txq,
+					 void *_unused)
+{
+	lockdep_set_class(&txq->_xmit_lock,
+			  &lowpan_netdev_xmit_lock_key);
+}
+
+
+static int lowpan_dev_init(struct net_device *dev)
+{
+	netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL);
+	dev->qdisc_tx_busylock = &lowpan_tx_busylock;
+	return 0;
+}
+
+static const struct net_device_ops lowpan_netdev_ops = {
+	.ndo_init		= lowpan_dev_init,
+	.ndo_start_xmit		= lowpan_xmit,
+	.ndo_set_mac_address	= lowpan_set_address,
+};
+
+static struct ieee802154_mlme_ops lowpan_mlme = {
+	.get_pan_id = lowpan_get_pan_id,
+	.get_phy = lowpan_get_phy,
+	.get_short_addr = lowpan_get_short_addr,
+	.get_dsn = lowpan_get_dsn,
+};
+
+static void lowpan_setup(struct net_device *dev)
+{
+	dev->addr_len		= IEEE802154_ADDR_LEN;
+	memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
+	dev->type		= ARPHRD_IEEE802154;
+	/* Frame Control + Sequence Number + Address fields + Security Header */
+	dev->hard_header_len	= 2 + 1 + 20 + 14;
+	dev->needed_tailroom	= 2; /* FCS */
+	dev->mtu		= 1281;
+	dev->tx_queue_len	= 0;
+	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;
+	dev->watchdog_timeo	= 0;
+
+	dev->netdev_ops		= &lowpan_netdev_ops;
+	dev->header_ops		= &lowpan_header_ops;
+	dev->ml_priv		= &lowpan_mlme;
+	dev->destructor		= free_netdev;
+}
+
+static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
+	struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct sk_buff *local_skb;
+
+	if (!netif_running(dev))
+		goto drop;
+
+	if (dev->type != ARPHRD_IEEE802154)
+		goto drop;
+
+	/* check that it's our buffer */
+	if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
+		/* Copy the packet so that the IPv6 header is
+		 * properly aligned.
+		 */
+		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
+					    skb_tailroom(skb), GFP_ATOMIC);
+		if (!local_skb)
+			goto drop;
+
+		local_skb->protocol = htons(ETH_P_IPV6);
+		local_skb->pkt_type = PACKET_HOST;
+
+		/* Pull off the 1-byte of 6lowpan header. */
+		skb_pull(local_skb, 1);
+
+		lowpan_give_skb_to_devices(local_skb, NULL);
+
+		kfree_skb(local_skb);
+		kfree_skb(skb);
+	} else {
+		switch (skb->data[0] & 0xe0) {
+		case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
+		case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
+		case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
+			local_skb = skb_clone(skb, GFP_ATOMIC);
+			if (!local_skb)
+				goto drop;
+			process_data(local_skb);
+
+			kfree_skb(skb);
+			break;
+		default:
+			break;
+		}
+	}
+
+	return NET_RX_SUCCESS;
+
+drop:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+static int lowpan_newlink(struct net *src_net, struct net_device *dev,
+			  struct nlattr *tb[], struct nlattr *data[])
+{
+	struct net_device *real_dev;
+	struct lowpan_dev_record *entry;
+
+	pr_debug("adding new link\n");
+
+	if (!tb[IFLA_LINK])
+		return -EINVAL;
+	/* find and hold real wpan device */
+	real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+	if (!real_dev)
+		return -ENODEV;
+	if (real_dev->type != ARPHRD_IEEE802154) {
+		dev_put(real_dev);
+		return -EINVAL;
+	}
+
+	lowpan_dev_info(dev)->real_dev = real_dev;
+	lowpan_dev_info(dev)->fragment_tag = 0;
+	mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
+
+	entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
+	if (!entry) {
+		dev_put(real_dev);
+		lowpan_dev_info(dev)->real_dev = NULL;
+		return -ENOMEM;
+	}
+
+	entry->ldev = dev;
+
+	/* Set the lowpan harware address to the wpan hardware address. */
+	memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
+
+	mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
+	INIT_LIST_HEAD(&entry->list);
+	list_add_tail(&entry->list, &lowpan_devices);
+	mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
+
+	register_netdevice(dev);
+
+	return 0;
+}
+
+static void lowpan_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
+	struct net_device *real_dev = lowpan_dev->real_dev;
+	struct lowpan_dev_record *entry, *tmp;
+
+	ASSERT_RTNL();
+
+	mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
+	list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
+		if (entry->ldev == dev) {
+			list_del(&entry->list);
+			kfree(entry);
+		}
+	}
+	mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
+
+	mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
+
+	unregister_netdevice_queue(dev, head);
+
+	dev_put(real_dev);
+}
+
+static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
+	.kind		= "lowpan",
+	.priv_size	= sizeof(struct lowpan_dev_info),
+	.setup		= lowpan_setup,
+	.newlink	= lowpan_newlink,
+	.dellink	= lowpan_dellink,
+	.validate	= lowpan_validate,
+};
+
+static inline int __init lowpan_netlink_init(void)
+{
+	return rtnl_link_register(&lowpan_link_ops);
+}
+
+static inline void lowpan_netlink_fini(void)
+{
+	rtnl_link_unregister(&lowpan_link_ops);
+}
+
+static int lowpan_device_event(struct notifier_block *unused,
+			       unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	LIST_HEAD(del_list);
+	struct lowpan_dev_record *entry, *tmp;
+
+	if (dev->type != ARPHRD_IEEE802154)
+		goto out;
+
+	if (event == NETDEV_UNREGISTER) {
+		list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
+			if (lowpan_dev_info(entry->ldev)->real_dev == dev)
+				lowpan_dellink(entry->ldev, &del_list);
+		}
+
+		unregister_netdevice_many(&del_list);
+	}
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block lowpan_dev_notifier = {
+	.notifier_call = lowpan_device_event,
+};
+
+static struct packet_type lowpan_packet_type = {
+	.type = __constant_htons(ETH_P_IEEE802154),
+	.func = lowpan_rcv,
+};
+
+static int __init lowpan_init_module(void)
+{
+	int err = 0;
+
+	err = lowpan_netlink_init();
+	if (err < 0)
+		goto out;
+
+	dev_add_pack(&lowpan_packet_type);
+
+	err = register_netdevice_notifier(&lowpan_dev_notifier);
+	if (err < 0) {
+		dev_remove_pack(&lowpan_packet_type);
+		lowpan_netlink_fini();
+	}
+out:
+	return err;
+}
+
+static void __exit lowpan_cleanup_module(void)
+{
+	struct lowpan_fragment *frame, *tframe;
+
+	lowpan_netlink_fini();
+
+	dev_remove_pack(&lowpan_packet_type);
+
+	unregister_netdevice_notifier(&lowpan_dev_notifier);
+
+	/* Now 6lowpan packet_type is removed, so no new fragments are
+	 * expected on RX, therefore that's the time to clean incomplete
+	 * fragments.
+	 */
+	spin_lock_bh(&flist_lock);
+	list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
+		del_timer_sync(&frame->timer);
+		list_del(&frame->list);
+		dev_kfree_skb(frame->skb);
+		kfree(frame);
+	}
+	spin_unlock_bh(&flist_lock);
+}
+
+module_init(lowpan_init_module);
+module_exit(lowpan_cleanup_module);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("lowpan");