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linux-7.2.3/net/ieee802154/6lowpan/6lowpan_i.h

@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __IEEE802154_6LOWPAN_I_H__
+#define __IEEE802154_6LOWPAN_I_H__
+
+#include <linux/list.h>
+
+#include <net/ieee802154_netdev.h>
+#include <net/inet_frag.h>
+#include <net/6lowpan.h>
+
+typedef unsigned __bitwise lowpan_rx_result;
+#define RX_CONTINUE		((__force lowpan_rx_result) 0u)
+#define RX_DROP_UNUSABLE	((__force lowpan_rx_result) 1u)
+#define RX_DROP			((__force lowpan_rx_result) 2u)
+#define RX_QUEUED		((__force lowpan_rx_result) 3u)
+
+#define LOWPAN_DISPATCH_FRAG1           0xc0
+#define LOWPAN_DISPATCH_FRAGN           0xe0
+
+struct frag_lowpan_compare_key {
+	u16 tag;
+	u16 d_size;
+	struct ieee802154_addr src;
+	struct ieee802154_addr dst;
+};
+
+/* Equivalent of ipv4 struct ipq
+ */
+struct lowpan_frag_queue {
+	struct inet_frag_queue	q;
+};
+
+int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type);
+void lowpan_net_frag_exit(void);
+int lowpan_net_frag_init(void);
+
+void lowpan_rx_init(void);
+void lowpan_rx_exit(void);
+
+int lowpan_header_create(struct sk_buff *skb, struct net_device *dev,
+			 unsigned short type, const void *_daddr,
+			 const void *_saddr, unsigned int len);
+netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev);
+
+int lowpan_iphc_decompress(struct sk_buff *skb);
+lowpan_rx_result lowpan_rx_h_ipv6(struct sk_buff *skb);
+
+#endif /* __IEEE802154_6LOWPAN_I_H__ */

linux-7.2.3/net/ieee802154/6lowpan/Kconfig

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config IEEE802154_6LOWPAN
+	tristate "6lowpan support over IEEE 802.15.4"
+	depends on 6LOWPAN
+	help
+	  IPv6 compression over IEEE 802.15.4.

linux-7.2.3/net/ieee802154/6lowpan/Makefile

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_IEEE802154_6LOWPAN) += ieee802154_6lowpan.o
+
+ieee802154_6lowpan-y := core.o rx.o reassembly.o tx.o

linux-7.2.3/net/ieee802154/6lowpan/core.c

@@ -0,0 +1,289 @@
+/* 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.
+ */
+
+/* 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/module.h>
+#include <linux/netdevice.h>
+#include <linux/ieee802154.h>
+#include <linux/if_arp.h>
+
+#include <net/ipv6.h>
+#include <net/netdev_lock.h>
+
+#include "6lowpan_i.h"
+
+static int open_count;
+
+static const struct header_ops lowpan_header_ops = {
+	.create	= lowpan_header_create,
+};
+
+static int lowpan_dev_init(struct net_device *ldev)
+{
+	netdev_lockdep_set_classes(ldev);
+
+	return 0;
+}
+
+static int lowpan_open(struct net_device *dev)
+{
+	if (!open_count)
+		lowpan_rx_init();
+	open_count++;
+	return 0;
+}
+
+static int lowpan_stop(struct net_device *dev)
+{
+	open_count--;
+	if (!open_count)
+		lowpan_rx_exit();
+	return 0;
+}
+
+static int lowpan_neigh_construct(struct net_device *dev, struct neighbour *n)
+{
+	struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
+
+	/* default no short_addr is available for a neighbour */
+	neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+	return 0;
+}
+
+static int lowpan_get_iflink(const struct net_device *dev)
+{
+	return READ_ONCE(lowpan_802154_dev(dev)->wdev->ifindex);
+}
+
+static const struct net_device_ops lowpan_netdev_ops = {
+	.ndo_init		= lowpan_dev_init,
+	.ndo_start_xmit		= lowpan_xmit,
+	.ndo_open		= lowpan_open,
+	.ndo_stop		= lowpan_stop,
+	.ndo_neigh_construct    = lowpan_neigh_construct,
+	.ndo_get_iflink         = lowpan_get_iflink,
+};
+
+static void lowpan_setup(struct net_device *ldev)
+{
+	memset(ldev->broadcast, 0xff, IEEE802154_ADDR_LEN);
+	/* We need an ipv6hdr as minimum len when calling xmit */
+	ldev->hard_header_len	= sizeof(struct ipv6hdr);
+	ldev->flags		= IFF_BROADCAST | IFF_MULTICAST;
+	ldev->priv_flags	|= IFF_NO_QUEUE;
+
+	ldev->netdev_ops	= &lowpan_netdev_ops;
+	ldev->header_ops	= &lowpan_header_ops;
+	ldev->needs_free_netdev	= true;
+	ldev->netns_immutable	= true;
+}
+
+static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],
+			   struct netlink_ext_ack *extack)
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static int lowpan_newlink(struct net_device *ldev,
+			  struct rtnl_newlink_params *params,
+			  struct netlink_ext_ack *extack)
+{
+	struct nlattr **tb = params->tb;
+	struct net_device *wdev;
+	int ret;
+
+	ASSERT_RTNL();
+
+	pr_debug("adding new link\n");
+
+	if (!tb[IFLA_LINK])
+		return -EINVAL;
+	if (params->link_net && !net_eq(params->link_net, dev_net(ldev)))
+		return -EINVAL;
+	/* find and hold wpan device */
+	wdev = dev_get_by_index(dev_net(ldev), nla_get_u32(tb[IFLA_LINK]));
+	if (!wdev)
+		return -ENODEV;
+	if (wdev->type != ARPHRD_IEEE802154) {
+		dev_put(wdev);
+		return -EINVAL;
+	}
+
+	if (wdev->ieee802154_ptr->lowpan_dev) {
+		dev_put(wdev);
+		return -EBUSY;
+	}
+
+	lowpan_802154_dev(ldev)->wdev = wdev;
+	/* Set the lowpan hardware address to the wpan hardware address. */
+	__dev_addr_set(ldev, wdev->dev_addr, IEEE802154_ADDR_LEN);
+	/* We need headroom for possible wpan_dev_hard_header call and tailroom
+	 * for encryption/fcs handling. The lowpan interface will replace
+	 * the IPv6 header with 6LoWPAN header. At worst case the 6LoWPAN
+	 * header has LOWPAN_IPHC_MAX_HEADER_LEN more bytes than the IPv6
+	 * header.
+	 */
+	ldev->needed_headroom = LOWPAN_IPHC_MAX_HEADER_LEN +
+				wdev->needed_headroom;
+	ldev->needed_tailroom = wdev->needed_tailroom;
+
+	ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh);
+
+	ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
+	if (ret < 0) {
+		dev_put(wdev);
+		return ret;
+	}
+
+	wdev->ieee802154_ptr->lowpan_dev = ldev;
+	return 0;
+}
+
+static void lowpan_dellink(struct net_device *ldev, struct list_head *head)
+{
+	struct net_device *wdev = lowpan_802154_dev(ldev)->wdev;
+
+	ASSERT_RTNL();
+
+	wdev->ieee802154_ptr->lowpan_dev = NULL;
+	lowpan_unregister_netdevice(ldev);
+	dev_put(wdev);
+}
+
+static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
+	.kind		= "lowpan",
+	.priv_size	= LOWPAN_PRIV_SIZE(sizeof(struct lowpan_802154_dev)),
+	.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 *ndev = netdev_notifier_info_to_dev(ptr);
+	struct wpan_dev *wpan_dev;
+
+	if (ndev->type != ARPHRD_IEEE802154)
+		return NOTIFY_DONE;
+	wpan_dev = ndev->ieee802154_ptr;
+	if (!wpan_dev)
+		return NOTIFY_DONE;
+
+	switch (event) {
+	case NETDEV_UNREGISTER:
+		/* Check if wpan interface is unregistered that we
+		 * also delete possible lowpan interfaces which belongs
+		 * to the wpan interface.
+		 */
+		if (wpan_dev->lowpan_dev)
+			lowpan_dellink(wpan_dev->lowpan_dev, NULL);
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block lowpan_dev_notifier = {
+	.notifier_call = lowpan_device_event,
+};
+
+static int __init lowpan_init_module(void)
+{
+	int err = 0;
+
+	err = lowpan_net_frag_init();
+	if (err < 0)
+		goto out;
+
+	err = lowpan_netlink_init();
+	if (err < 0)
+		goto out_frag;
+
+	err = register_netdevice_notifier(&lowpan_dev_notifier);
+	if (err < 0)
+		goto out_pack;
+
+	return 0;
+
+out_pack:
+	lowpan_netlink_fini();
+out_frag:
+	lowpan_net_frag_exit();
+out:
+	return err;
+}
+
+static void __exit lowpan_cleanup_module(void)
+{
+	lowpan_netlink_fini();
+
+	lowpan_net_frag_exit();
+
+	unregister_netdevice_notifier(&lowpan_dev_notifier);
+}
+
+module_init(lowpan_init_module);
+module_exit(lowpan_cleanup_module);
+MODULE_DESCRIPTION("IPv6 over Low power Wireless Personal Area Network IEEE 802.15.4 core");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("lowpan");

linux-7.2.3/net/ieee802154/6lowpan/reassembly.c

@@ -0,0 +1,558 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*	6LoWPAN fragment reassembly
+ *
+ *	Authors:
+ *	Alexander Aring		<aar@pengutronix.de>
+ *
+ *	Based on: net/ipv6/reassembly.c
+ */
+
+#define pr_fmt(fmt) "6LoWPAN: " fmt
+
+#include <linux/net.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+#include <net/ieee802154_netdev.h>
+#include <net/6lowpan.h>
+#include <net/ipv6_frag.h>
+#include <net/inet_frag.h>
+#include <net/ip.h>
+
+#include "6lowpan_i.h"
+
+static const char lowpan_frags_cache_name[] = "lowpan-frags";
+
+static struct inet_frags lowpan_frags;
+
+static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, struct sk_buff *skb,
+			     struct sk_buff *prev, struct net_device *ldev,
+			     int *refs);
+
+static void lowpan_frag_init(struct inet_frag_queue *q, const void *a)
+{
+	const struct frag_lowpan_compare_key *key = a;
+
+	BUILD_BUG_ON(sizeof(*key) > sizeof(q->key));
+	memcpy(&q->key, key, sizeof(*key));
+}
+
+static void lowpan_frag_expire(struct timer_list *t)
+{
+	struct inet_frag_queue *frag = timer_container_of(frag, t, timer);
+	struct frag_queue *fq;
+	int refs = 1;
+
+	fq = container_of(frag, struct frag_queue, q);
+
+	spin_lock(&fq->q.lock);
+
+	if (fq->q.flags & INET_FRAG_COMPLETE)
+		goto out;
+
+	inet_frag_kill(&fq->q, &refs);
+out:
+	spin_unlock(&fq->q.lock);
+	inet_frag_putn(&fq->q, refs);
+}
+
+static inline struct lowpan_frag_queue *
+fq_find(struct net *net, const struct lowpan_802154_cb *cb,
+	const struct ieee802154_addr *src,
+	const struct ieee802154_addr *dst)
+{
+	struct netns_ieee802154_lowpan *ieee802154_lowpan =
+		net_ieee802154_lowpan(net);
+	struct frag_lowpan_compare_key key = {};
+	struct inet_frag_queue *q;
+
+	key.tag = cb->d_tag;
+	key.d_size = cb->d_size;
+	key.src = *src;
+	key.dst = *dst;
+
+	q = inet_frag_find(ieee802154_lowpan->fqdir, &key);
+	if (!q)
+		return NULL;
+
+	return container_of(q, struct lowpan_frag_queue, q);
+}
+
+static int lowpan_frag_queue(struct lowpan_frag_queue *fq,
+			     struct sk_buff *skb, u8 frag_type,
+			     int *refs)
+{
+	struct sk_buff *prev_tail;
+	struct net_device *ldev;
+	int end, offset, err;
+
+	/* inet_frag_queue_* functions use skb->cb; see struct ipfrag_skb_cb
+	 * in inet_fragment.c
+	 */
+	BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(struct inet_skb_parm));
+	BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(struct inet6_skb_parm));
+
+	if (fq->q.flags & INET_FRAG_COMPLETE)
+		goto err;
+
+	offset = lowpan_802154_cb(skb)->d_offset << 3;
+	end = lowpan_802154_cb(skb)->d_size;
+
+	/* Is this the final fragment? */
+	if (offset + skb->len == end) {
+		/* If we already have some bits beyond end
+		 * or have different end, the segment is corrupted.
+		 */
+		if (end < fq->q.len ||
+		    ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len))
+			goto err;
+		fq->q.flags |= INET_FRAG_LAST_IN;
+		fq->q.len = end;
+	} else {
+		if (end > fq->q.len) {
+			/* Some bits beyond end -> corruption. */
+			if (fq->q.flags & INET_FRAG_LAST_IN)
+				goto err;
+			fq->q.len = end;
+		}
+	}
+
+	ldev = skb->dev;
+	if (ldev)
+		skb->dev = NULL;
+	barrier();
+
+	prev_tail = fq->q.fragments_tail;
+	err = inet_frag_queue_insert(&fq->q, skb, offset, end);
+	if (err)
+		goto err;
+
+	fq->q.stamp = skb->tstamp;
+	fq->q.tstamp_type = skb->tstamp_type;
+	if (frag_type == LOWPAN_DISPATCH_FRAG1)
+		fq->q.flags |= INET_FRAG_FIRST_IN;
+
+	fq->q.meat += skb->len;
+	add_frag_mem_limit(fq->q.fqdir, skb->truesize);
+
+	if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
+	    fq->q.meat == fq->q.len) {
+		int res;
+		unsigned long orefdst = skb->_skb_refdst;
+
+		skb->_skb_refdst = 0UL;
+		res = lowpan_frag_reasm(fq, skb, prev_tail, ldev, refs);
+		skb->_skb_refdst = orefdst;
+		return res;
+	}
+	skb_dst_drop(skb);
+
+	return -1;
+err:
+	kfree_skb(skb);
+	return -1;
+}
+
+/*	Check if this packet is complete.
+ *
+ *	It is called with locked fq, and caller must check that
+ *	queue is eligible for reassembly i.e. it is not COMPLETE,
+ *	the last and the first frames arrived and all the bits are here.
+ */
+static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, struct sk_buff *skb,
+			     struct sk_buff *prev_tail, struct net_device *ldev,
+			     int *refs)
+{
+	void *reasm_data;
+
+	inet_frag_kill(&fq->q, refs);
+
+	reasm_data = inet_frag_reasm_prepare(&fq->q, skb, prev_tail);
+	if (!reasm_data)
+		goto out_oom;
+	inet_frag_reasm_finish(&fq->q, skb, reasm_data, false);
+
+	skb->dev = ldev;
+	skb->tstamp = fq->q.stamp;
+	fq->q.rb_fragments = RB_ROOT;
+	fq->q.fragments_tail = NULL;
+	fq->q.last_run_head = NULL;
+
+	return 1;
+out_oom:
+	net_dbg_ratelimited("lowpan_frag_reasm: no memory for reassembly\n");
+	return -1;
+}
+
+static int lowpan_frag_rx_handlers_result(struct sk_buff *skb,
+					  lowpan_rx_result res)
+{
+	switch (res) {
+	case RX_QUEUED:
+		return NET_RX_SUCCESS;
+	case RX_CONTINUE:
+		/* nobody cared about this packet */
+		net_warn_ratelimited("%s: received unknown dispatch\n",
+				     __func__);
+
+		fallthrough;
+	default:
+		/* all others failure */
+		return NET_RX_DROP;
+	}
+}
+
+static lowpan_rx_result lowpan_frag_rx_h_iphc(struct sk_buff *skb)
+{
+	int ret;
+
+	if (!lowpan_is_iphc(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	ret = lowpan_iphc_decompress(skb);
+	if (ret < 0)
+		return RX_DROP;
+
+	return RX_QUEUED;
+}
+
+static int lowpan_invoke_frag_rx_handlers(struct sk_buff *skb)
+{
+	lowpan_rx_result res;
+
+#define CALL_RXH(rxh)			\
+	do {				\
+		res = rxh(skb);	\
+		if (res != RX_CONTINUE)	\
+			goto rxh_next;	\
+	} while (0)
+
+	/* likely at first */
+	CALL_RXH(lowpan_frag_rx_h_iphc);
+	CALL_RXH(lowpan_rx_h_ipv6);
+
+rxh_next:
+	return lowpan_frag_rx_handlers_result(skb, res);
+#undef CALL_RXH
+}
+
+#define LOWPAN_FRAG_DGRAM_SIZE_HIGH_MASK	0x07
+#define LOWPAN_FRAG_DGRAM_SIZE_HIGH_SHIFT	8
+
+static int lowpan_get_cb(struct sk_buff *skb, u8 frag_type,
+			 struct lowpan_802154_cb *cb)
+{
+	bool fail;
+	u8 high = 0, low = 0;
+	__be16 d_tag = 0;
+
+	fail = lowpan_fetch_skb(skb, &high, 1);
+	fail |= lowpan_fetch_skb(skb, &low, 1);
+	/* remove the dispatch value and use first three bits as high value
+	 * for the datagram size
+	 */
+	cb->d_size = (high & LOWPAN_FRAG_DGRAM_SIZE_HIGH_MASK) <<
+		LOWPAN_FRAG_DGRAM_SIZE_HIGH_SHIFT | low;
+	fail |= lowpan_fetch_skb(skb, &d_tag, 2);
+	cb->d_tag = ntohs(d_tag);
+
+	if (frag_type == LOWPAN_DISPATCH_FRAGN) {
+		fail |= lowpan_fetch_skb(skb, &cb->d_offset, 1);
+	} else {
+		skb_reset_network_header(skb);
+		cb->d_offset = 0;
+		/* check if datagram_size has ipv6hdr on FRAG1 */
+		fail |= cb->d_size < sizeof(struct ipv6hdr);
+		/* check if we can dereference the dispatch value */
+		fail |= !skb->len;
+	}
+
+	if (unlikely(fail))
+		return -EIO;
+
+	return 0;
+}
+
+int lowpan_frag_rcv(struct sk_buff *skb, u8 frag_type)
+{
+	struct lowpan_frag_queue *fq;
+	struct net *net = dev_net(skb->dev);
+	struct lowpan_802154_cb *cb = lowpan_802154_cb(skb);
+	struct ieee802154_hdr hdr = {};
+	int err;
+
+	if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
+		goto err;
+
+	err = lowpan_get_cb(skb, frag_type, cb);
+	if (err < 0)
+		goto err;
+
+	if (frag_type == LOWPAN_DISPATCH_FRAG1) {
+		err = lowpan_invoke_frag_rx_handlers(skb);
+		if (err == NET_RX_DROP)
+			goto err;
+	}
+
+	if (cb->d_size > IPV6_MIN_MTU) {
+		net_warn_ratelimited("lowpan_frag_rcv: datagram size exceeds MTU\n");
+		goto err;
+	}
+
+	rcu_read_lock();
+	fq = fq_find(net, cb, &hdr.source, &hdr.dest);
+	if (fq != NULL) {
+		int ret, refs = 0;
+
+		spin_lock(&fq->q.lock);
+		ret = lowpan_frag_queue(fq, skb, frag_type, &refs);
+		spin_unlock(&fq->q.lock);
+
+		rcu_read_unlock();
+		inet_frag_putn(&fq->q, refs);
+		return ret;
+	}
+	rcu_read_unlock();
+
+err:
+	kfree_skb(skb);
+	return -1;
+}
+
+#ifdef CONFIG_SYSCTL
+
+static struct ctl_table lowpan_frags_ns_ctl_table[] = {
+	{
+		.procname	= "6lowpanfrag_high_thresh",
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+	},
+	{
+		.procname	= "6lowpanfrag_low_thresh",
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+	},
+	{
+		.procname	= "6lowpanfrag_time",
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+};
+
+/* secret interval has been deprecated */
+static int lowpan_frags_secret_interval_unused;
+static struct ctl_table lowpan_frags_ctl_table[] = {
+	{
+		.procname	= "6lowpanfrag_secret_interval",
+		.data		= &lowpan_frags_secret_interval_unused,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+};
+
+static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
+{
+	struct ctl_table *table;
+	struct ctl_table_header *hdr;
+	struct netns_ieee802154_lowpan *ieee802154_lowpan =
+		net_ieee802154_lowpan(net);
+	size_t table_size = ARRAY_SIZE(lowpan_frags_ns_ctl_table);
+
+	table = lowpan_frags_ns_ctl_table;
+	if (!net_eq(net, &init_net)) {
+		table = kmemdup(table, sizeof(lowpan_frags_ns_ctl_table),
+				GFP_KERNEL);
+		if (table == NULL)
+			goto err_alloc;
+
+		/* Don't export sysctls to unprivileged users */
+		if (net->user_ns != &init_user_ns)
+			table_size = 0;
+	}
+
+	table[0].data	= &ieee802154_lowpan->fqdir->high_thresh;
+	table[0].extra1	= &ieee802154_lowpan->fqdir->low_thresh;
+	table[1].data	= &ieee802154_lowpan->fqdir->low_thresh;
+	table[1].extra2	= &ieee802154_lowpan->fqdir->high_thresh;
+	table[2].data	= &ieee802154_lowpan->fqdir->timeout;
+
+	hdr = register_net_sysctl_sz(net, "net/ieee802154/6lowpan", table,
+				     table_size);
+	if (hdr == NULL)
+		goto err_reg;
+
+	ieee802154_lowpan->sysctl.frags_hdr = hdr;
+	return 0;
+
+err_reg:
+	if (!net_eq(net, &init_net))
+		kfree(table);
+err_alloc:
+	return -ENOMEM;
+}
+
+static void __net_exit lowpan_frags_ns_sysctl_unregister(struct net *net)
+{
+	const struct ctl_table *table;
+	struct netns_ieee802154_lowpan *ieee802154_lowpan =
+		net_ieee802154_lowpan(net);
+
+	table = ieee802154_lowpan->sysctl.frags_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(ieee802154_lowpan->sysctl.frags_hdr);
+	if (!net_eq(net, &init_net))
+		kfree(table);
+}
+
+static struct ctl_table_header *lowpan_ctl_header;
+
+static int __init lowpan_frags_sysctl_register(void)
+{
+	lowpan_ctl_header = register_net_sysctl(&init_net,
+						"net/ieee802154/6lowpan",
+						lowpan_frags_ctl_table);
+	return lowpan_ctl_header == NULL ? -ENOMEM : 0;
+}
+
+static void lowpan_frags_sysctl_unregister(void)
+{
+	unregister_net_sysctl_table(lowpan_ctl_header);
+}
+#else
+static inline int lowpan_frags_ns_sysctl_register(struct net *net)
+{
+	return 0;
+}
+
+static inline void lowpan_frags_ns_sysctl_unregister(struct net *net)
+{
+}
+
+static inline int __init lowpan_frags_sysctl_register(void)
+{
+	return 0;
+}
+
+static inline void lowpan_frags_sysctl_unregister(void)
+{
+}
+#endif
+
+static int __net_init lowpan_frags_init_net(struct net *net)
+{
+	struct netns_ieee802154_lowpan *ieee802154_lowpan =
+		net_ieee802154_lowpan(net);
+	int res;
+
+
+	res = fqdir_init(&ieee802154_lowpan->fqdir, &lowpan_frags, net);
+	if (res < 0)
+		return res;
+
+	ieee802154_lowpan->fqdir->high_thresh = IPV6_FRAG_HIGH_THRESH;
+	ieee802154_lowpan->fqdir->low_thresh = IPV6_FRAG_LOW_THRESH;
+	ieee802154_lowpan->fqdir->timeout = IPV6_FRAG_TIMEOUT;
+
+	res = lowpan_frags_ns_sysctl_register(net);
+	if (res < 0)
+		fqdir_exit(ieee802154_lowpan->fqdir);
+	return res;
+}
+
+static void __net_exit lowpan_frags_pre_exit_net(struct net *net)
+{
+	struct netns_ieee802154_lowpan *ieee802154_lowpan =
+		net_ieee802154_lowpan(net);
+
+	fqdir_pre_exit(ieee802154_lowpan->fqdir);
+}
+
+static void __net_exit lowpan_frags_exit_net(struct net *net)
+{
+	struct netns_ieee802154_lowpan *ieee802154_lowpan =
+		net_ieee802154_lowpan(net);
+
+	lowpan_frags_ns_sysctl_unregister(net);
+	fqdir_exit(ieee802154_lowpan->fqdir);
+}
+
+static struct pernet_operations lowpan_frags_ops = {
+	.init		= lowpan_frags_init_net,
+	.pre_exit	= lowpan_frags_pre_exit_net,
+	.exit		= lowpan_frags_exit_net,
+};
+
+static u32 lowpan_key_hashfn(const void *data, u32 len, u32 seed)
+{
+	return jhash2(data,
+		      sizeof(struct frag_lowpan_compare_key) / sizeof(u32), seed);
+}
+
+static u32 lowpan_obj_hashfn(const void *data, u32 len, u32 seed)
+{
+	const struct inet_frag_queue *fq = data;
+
+	return jhash2((const u32 *)&fq->key,
+		      sizeof(struct frag_lowpan_compare_key) / sizeof(u32), seed);
+}
+
+static int lowpan_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
+{
+	const struct frag_lowpan_compare_key *key = arg->key;
+	const struct inet_frag_queue *fq = ptr;
+
+	return !!memcmp(&fq->key, key, sizeof(*key));
+}
+
+static const struct rhashtable_params lowpan_rhash_params = {
+	.head_offset		= offsetof(struct inet_frag_queue, node),
+	.hashfn			= lowpan_key_hashfn,
+	.obj_hashfn		= lowpan_obj_hashfn,
+	.obj_cmpfn		= lowpan_obj_cmpfn,
+	.automatic_shrinking	= true,
+};
+
+int __init lowpan_net_frag_init(void)
+{
+	int ret;
+
+	lowpan_frags.constructor = lowpan_frag_init;
+	lowpan_frags.destructor = NULL;
+	lowpan_frags.qsize = sizeof(struct frag_queue);
+	lowpan_frags.frag_expire = lowpan_frag_expire;
+	lowpan_frags.frags_cache_name = lowpan_frags_cache_name;
+	lowpan_frags.rhash_params = lowpan_rhash_params;
+	ret = inet_frags_init(&lowpan_frags);
+	if (ret)
+		goto out;
+
+	ret = lowpan_frags_sysctl_register();
+	if (ret)
+		goto err_sysctl;
+
+	ret = register_pernet_subsys(&lowpan_frags_ops);
+	if (ret)
+		goto err_pernet;
+out:
+	return ret;
+err_pernet:
+	lowpan_frags_sysctl_unregister();
+err_sysctl:
+	inet_frags_fini(&lowpan_frags);
+	return ret;
+}
+
+void lowpan_net_frag_exit(void)
+{
+	lowpan_frags_sysctl_unregister();
+	unregister_pernet_subsys(&lowpan_frags_ops);
+	inet_frags_fini(&lowpan_frags);
+}

linux-7.2.3/net/ieee802154/6lowpan/rx.c

@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/if_arp.h>
+
+#include <net/6lowpan.h>
+#include <net/mac802154.h>
+#include <net/ieee802154_netdev.h>
+
+#include "6lowpan_i.h"
+
+#define LOWPAN_DISPATCH_FIRST		0xc0
+#define LOWPAN_DISPATCH_FRAG_MASK	0xf8
+
+#define LOWPAN_DISPATCH_NALP		0x00
+#define LOWPAN_DISPATCH_ESC		0x40
+#define LOWPAN_DISPATCH_HC1		0x42
+#define LOWPAN_DISPATCH_DFF		0x43
+#define LOWPAN_DISPATCH_BC0		0x50
+#define LOWPAN_DISPATCH_MESH		0x80
+
+static int lowpan_give_skb_to_device(struct sk_buff *skb)
+{
+	skb->protocol = htons(ETH_P_IPV6);
+	skb->dev->stats.rx_packets++;
+	skb->dev->stats.rx_bytes += skb->len;
+
+	return netif_rx(skb);
+}
+
+static int lowpan_rx_handlers_result(struct sk_buff *skb, lowpan_rx_result res)
+{
+	switch (res) {
+	case RX_CONTINUE:
+		/* nobody cared about this packet */
+		net_warn_ratelimited("%s: received unknown dispatch\n",
+				     __func__);
+
+		fallthrough;
+	case RX_DROP_UNUSABLE:
+		kfree_skb(skb);
+
+		fallthrough;
+	case RX_DROP:
+		return NET_RX_DROP;
+	case RX_QUEUED:
+		return lowpan_give_skb_to_device(skb);
+	default:
+		break;
+	}
+
+	return NET_RX_DROP;
+}
+
+static inline bool lowpan_is_frag1(u8 dispatch)
+{
+	return (dispatch & LOWPAN_DISPATCH_FRAG_MASK) == LOWPAN_DISPATCH_FRAG1;
+}
+
+static inline bool lowpan_is_fragn(u8 dispatch)
+{
+	return (dispatch & LOWPAN_DISPATCH_FRAG_MASK) == LOWPAN_DISPATCH_FRAGN;
+}
+
+static lowpan_rx_result lowpan_rx_h_frag(struct sk_buff *skb)
+{
+	int ret;
+
+	if (!(lowpan_is_frag1(*skb_network_header(skb)) ||
+	      lowpan_is_fragn(*skb_network_header(skb))))
+		return RX_CONTINUE;
+
+	ret = lowpan_frag_rcv(skb, *skb_network_header(skb) &
+			      LOWPAN_DISPATCH_FRAG_MASK);
+	if (ret == 1)
+		return RX_QUEUED;
+
+	/* Packet is freed by lowpan_frag_rcv on error or put into the frag
+	 * bucket.
+	 */
+	return RX_DROP;
+}
+
+int lowpan_iphc_decompress(struct sk_buff *skb)
+{
+	struct ieee802154_hdr hdr;
+
+	if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
+		return -EINVAL;
+
+	return lowpan_header_decompress(skb, skb->dev, &hdr.dest, &hdr.source);
+}
+
+static lowpan_rx_result lowpan_rx_h_iphc(struct sk_buff *skb)
+{
+	int ret;
+
+	if (!lowpan_is_iphc(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	/* Setting datagram_offset to zero indicates non frag handling
+	 * while doing lowpan_header_decompress.
+	 */
+	lowpan_802154_cb(skb)->d_size = 0;
+
+	ret = lowpan_iphc_decompress(skb);
+	if (ret < 0)
+		return RX_DROP_UNUSABLE;
+
+	return RX_QUEUED;
+}
+
+lowpan_rx_result lowpan_rx_h_ipv6(struct sk_buff *skb)
+{
+	if (!lowpan_is_ipv6(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	/* Pull off the 1-byte of 6lowpan header. */
+	skb_pull(skb, 1);
+	return RX_QUEUED;
+}
+
+static inline bool lowpan_is_esc(u8 dispatch)
+{
+	return dispatch == LOWPAN_DISPATCH_ESC;
+}
+
+static lowpan_rx_result lowpan_rx_h_esc(struct sk_buff *skb)
+{
+	if (!lowpan_is_esc(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	net_warn_ratelimited("%s: %s\n", skb->dev->name,
+			     "6LoWPAN ESC not supported\n");
+
+	return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_hc1(u8 dispatch)
+{
+	return dispatch == LOWPAN_DISPATCH_HC1;
+}
+
+static lowpan_rx_result lowpan_rx_h_hc1(struct sk_buff *skb)
+{
+	if (!lowpan_is_hc1(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	net_warn_ratelimited("%s: %s\n", skb->dev->name,
+			     "6LoWPAN HC1 not supported\n");
+
+	return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_dff(u8 dispatch)
+{
+	return dispatch == LOWPAN_DISPATCH_DFF;
+}
+
+static lowpan_rx_result lowpan_rx_h_dff(struct sk_buff *skb)
+{
+	if (!lowpan_is_dff(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	net_warn_ratelimited("%s: %s\n", skb->dev->name,
+			     "6LoWPAN DFF not supported\n");
+
+	return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_bc0(u8 dispatch)
+{
+	return dispatch == LOWPAN_DISPATCH_BC0;
+}
+
+static lowpan_rx_result lowpan_rx_h_bc0(struct sk_buff *skb)
+{
+	if (!lowpan_is_bc0(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	net_warn_ratelimited("%s: %s\n", skb->dev->name,
+			     "6LoWPAN BC0 not supported\n");
+
+	return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_mesh(u8 dispatch)
+{
+	return (dispatch & LOWPAN_DISPATCH_FIRST) == LOWPAN_DISPATCH_MESH;
+}
+
+static lowpan_rx_result lowpan_rx_h_mesh(struct sk_buff *skb)
+{
+	if (!lowpan_is_mesh(*skb_network_header(skb)))
+		return RX_CONTINUE;
+
+	net_warn_ratelimited("%s: %s\n", skb->dev->name,
+			     "6LoWPAN MESH not supported\n");
+
+	return RX_DROP_UNUSABLE;
+}
+
+static int lowpan_invoke_rx_handlers(struct sk_buff *skb)
+{
+	lowpan_rx_result res;
+
+#define CALL_RXH(rxh)			\
+	do {				\
+		res = rxh(skb);	\
+		if (res != RX_CONTINUE)	\
+			goto rxh_next;	\
+	} while (0)
+
+	/* likely at first */
+	CALL_RXH(lowpan_rx_h_iphc);
+	CALL_RXH(lowpan_rx_h_frag);
+	CALL_RXH(lowpan_rx_h_ipv6);
+	CALL_RXH(lowpan_rx_h_esc);
+	CALL_RXH(lowpan_rx_h_hc1);
+	CALL_RXH(lowpan_rx_h_dff);
+	CALL_RXH(lowpan_rx_h_bc0);
+	CALL_RXH(lowpan_rx_h_mesh);
+
+rxh_next:
+	return lowpan_rx_handlers_result(skb, res);
+#undef CALL_RXH
+}
+
+static inline bool lowpan_is_nalp(u8 dispatch)
+{
+	return (dispatch & LOWPAN_DISPATCH_FIRST) == LOWPAN_DISPATCH_NALP;
+}
+
+/* Lookup for reserved dispatch values at:
+ * https://www.iana.org/assignments/_6lowpan-parameters/_6lowpan-parameters.xhtml#_6lowpan-parameters-1
+ *
+ * Last Updated: 2015-01-22
+ */
+static inline bool lowpan_is_reserved(u8 dispatch)
+{
+	return ((dispatch >= 0x44 && dispatch <= 0x4F) ||
+		(dispatch >= 0x51 && dispatch <= 0x5F) ||
+		(dispatch >= 0xc8 && dispatch <= 0xdf) ||
+		dispatch >= 0xe8);
+}
+
+/* lowpan_rx_h_check checks on generic 6LoWPAN requirements
+ * in MAC and 6LoWPAN header.
+ *
+ * Don't manipulate the skb here, it could be shared buffer.
+ */
+static inline bool lowpan_rx_h_check(struct sk_buff *skb)
+{
+	__le16 fc = ieee802154_get_fc_from_skb(skb);
+
+	/* check on ieee802154 conform 6LoWPAN header */
+	if (!ieee802154_is_data(fc) ||
+	    !ieee802154_skb_is_intra_pan_addressing(fc, skb))
+		return false;
+
+	/* check if we can dereference the dispatch */
+	if (unlikely(!skb->len))
+		return false;
+
+	if (lowpan_is_nalp(*skb_network_header(skb)) ||
+	    lowpan_is_reserved(*skb_network_header(skb)))
+		return false;
+
+	return true;
+}
+
+static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev,
+		      struct packet_type *pt, struct net_device *orig_wdev)
+{
+	struct net_device *ldev;
+
+	if (wdev->type != ARPHRD_IEEE802154 ||
+	    skb->pkt_type == PACKET_OTHERHOST ||
+	    !lowpan_rx_h_check(skb))
+		goto drop;
+
+	ldev = wdev->ieee802154_ptr->lowpan_dev;
+	if (!ldev || !netif_running(ldev))
+		goto drop;
+
+	/* Replacing skb->dev and followed rx handlers will manipulate skb. */
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		goto out;
+	skb->dev = ldev;
+
+	/* When receive frag1 it's likely that we manipulate the buffer.
+	 * When recevie iphc we manipulate the data buffer. So we need
+	 * to unshare the buffer.
+	 */
+	if (lowpan_is_frag1(*skb_network_header(skb)) ||
+	    lowpan_is_iphc(*skb_network_header(skb))) {
+		skb = skb_unshare(skb, GFP_ATOMIC);
+		if (!skb)
+			goto out;
+	}
+
+	return lowpan_invoke_rx_handlers(skb);
+
+drop:
+	kfree_skb(skb);
+out:
+	return NET_RX_DROP;
+}
+
+static struct packet_type lowpan_packet_type = {
+	.type = htons(ETH_P_IEEE802154),
+	.func = lowpan_rcv,
+};
+
+void lowpan_rx_init(void)
+{
+	dev_add_pack(&lowpan_packet_type);
+}
+
+void lowpan_rx_exit(void)
+{
+	dev_remove_pack(&lowpan_packet_type);
+}

linux-7.2.3/net/ieee802154/6lowpan/tx.c

@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <net/6lowpan.h>
+#include <net/ndisc.h>
+#include <net/ieee802154_netdev.h>
+#include <net/mac802154.h>
+
+#include "6lowpan_i.h"
+
+#define LOWPAN_FRAG1_HEAD_SIZE	0x4
+#define LOWPAN_FRAGN_HEAD_SIZE	0x5
+
+struct lowpan_addr_info {
+	struct ieee802154_addr daddr;
+	struct ieee802154_addr saddr;
+};
+
+static inline struct
+lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
+{
+	WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info));
+	return (struct lowpan_addr_info *)(skb->data -
+			sizeof(struct lowpan_addr_info));
+}
+
+/* This callback will be called from AF_PACKET and IPv6 stack, the AF_PACKET
+ * sockets gives an 8 byte array for addresses only!
+ *
+ * TODO I think AF_PACKET DGRAM (sending/receiving) RAW (sending) makes no
+ * sense here. We should disable it, the right use-case would be AF_INET6
+ * RAW/DGRAM sockets.
+ */
+int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev,
+			 unsigned short type, const void *daddr,
+			 const void *saddr, unsigned int len)
+{
+	struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
+	struct lowpan_addr_info *info = lowpan_skb_priv(skb);
+	struct lowpan_802154_neigh *llneigh = NULL;
+	const struct ipv6hdr *hdr = ipv6_hdr(skb);
+	struct neighbour *n;
+
+	if (!daddr)
+		return -EINVAL;
+
+	/* TODO:
+	 * if this package isn't ipv6 one, where should it be routed?
+	 */
+	if (type != ETH_P_IPV6)
+		return 0;
+
+	/* intra-pan communication */
+	info->saddr.pan_id = wpan_dev->pan_id;
+	info->daddr.pan_id = info->saddr.pan_id;
+
+	if (!memcmp(daddr, ldev->broadcast, EUI64_ADDR_LEN)) {
+		info->daddr.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
+		info->daddr.mode = IEEE802154_ADDR_SHORT;
+	} else {
+		__le16 short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+
+		n = neigh_lookup(&nd_tbl, &hdr->daddr, ldev);
+		if (n) {
+			llneigh = lowpan_802154_neigh(neighbour_priv(n));
+			read_lock_bh(&n->lock);
+			short_addr = llneigh->short_addr;
+			read_unlock_bh(&n->lock);
+		}
+
+		if (llneigh &&
+		    lowpan_802154_is_valid_src_short_addr(short_addr)) {
+			info->daddr.short_addr = short_addr;
+			info->daddr.mode = IEEE802154_ADDR_SHORT;
+		} else {
+			info->daddr.mode = IEEE802154_ADDR_LONG;
+			ieee802154_be64_to_le64(&info->daddr.extended_addr,
+						daddr);
+		}
+
+		if (n)
+			neigh_release(n);
+	}
+
+	if (!saddr) {
+		if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
+			info->saddr.mode = IEEE802154_ADDR_SHORT;
+			info->saddr.short_addr = wpan_dev->short_addr;
+		} else {
+			info->saddr.mode = IEEE802154_ADDR_LONG;
+			info->saddr.extended_addr = wpan_dev->extended_addr;
+		}
+	} else {
+		info->saddr.mode = IEEE802154_ADDR_LONG;
+		ieee802154_be64_to_le64(&info->saddr.extended_addr, saddr);
+	}
+
+	return 0;
+}
+
+static struct sk_buff*
+lowpan_alloc_frag(struct sk_buff *skb, int size,
+		  const struct ieee802154_hdr *master_hdr, bool frag1)
+{
+	struct net_device *wdev = lowpan_802154_dev(skb->dev)->wdev;
+	struct sk_buff *frag;
+	int rc;
+
+	frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size,
+			 GFP_ATOMIC);
+
+	if (likely(frag)) {
+		frag->dev = wdev;
+		frag->priority = skb->priority;
+		skb_reserve(frag, wdev->needed_headroom);
+		skb_reset_network_header(frag);
+		*mac_cb(frag) = *mac_cb(skb);
+
+		if (frag1) {
+			skb_put_data(frag, skb_mac_header(skb), skb->mac_len);
+		} else {
+			rc = wpan_dev_hard_header(frag, wdev,
+						  &master_hdr->dest,
+						  &master_hdr->source, size);
+			if (rc < 0) {
+				kfree_skb(frag);
+				return ERR_PTR(rc);
+			}
+		}
+	} else {
+		frag = ERR_PTR(-ENOMEM);
+	}
+
+	return frag;
+}
+
+static int
+lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr,
+		     u8 *frag_hdr, int frag_hdrlen,
+		     int offset, int len, bool frag1)
+{
+	struct sk_buff *frag;
+
+	raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen);
+
+	frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1);
+	if (IS_ERR(frag))
+		return PTR_ERR(frag);
+
+	skb_put_data(frag, frag_hdr, frag_hdrlen);
+	skb_put_data(frag, skb_network_header(skb) + offset, len);
+
+	raw_dump_table(__func__, " fragment dump", frag->data, frag->len);
+
+	return dev_queue_xmit(frag);
+}
+
+static int
+lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev,
+		       const struct ieee802154_hdr *wpan_hdr, u16 dgram_size,
+		       u16 dgram_offset)
+{
+	__be16 frag_tag;
+	u8 frag_hdr[5];
+	int frag_cap, frag_len, payload_cap, rc;
+	int skb_unprocessed, skb_offset;
+
+	frag_tag = htons(lowpan_802154_dev(ldev)->fragment_tag);
+	lowpan_802154_dev(ldev)->fragment_tag++;
+
+	frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07);
+	frag_hdr[1] = dgram_size & 0xff;
+	memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag));
+
+	payload_cap = ieee802154_max_payload(wpan_hdr);
+
+	frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE -
+			      skb_network_header_len(skb), 8);
+
+	skb_offset = skb_network_header_len(skb);
+	skb_unprocessed = skb->len - skb->mac_len - skb_offset;
+
+	rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
+				  LOWPAN_FRAG1_HEAD_SIZE, 0,
+				  frag_len + skb_network_header_len(skb),
+				  true);
+	if (rc) {
+		pr_debug("%s unable to send FRAG1 packet (tag: %d)",
+			 __func__, ntohs(frag_tag));
+		goto err;
+	}
+
+	frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1;
+	frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN;
+	frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8);
+
+	do {
+		dgram_offset += frag_len;
+		skb_offset += frag_len;
+		skb_unprocessed -= frag_len;
+		frag_len = min(frag_cap, skb_unprocessed);
+
+		frag_hdr[4] = dgram_offset >> 3;
+
+		rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr,
+					  LOWPAN_FRAGN_HEAD_SIZE, skb_offset,
+					  frag_len, false);
+		if (rc) {
+			pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
+				 __func__, ntohs(frag_tag), skb_offset);
+			goto err;
+		}
+	} while (skb_unprocessed > frag_cap);
+
+	ldev->stats.tx_packets++;
+	ldev->stats.tx_bytes += dgram_size;
+	consume_skb(skb);
+	return NET_XMIT_SUCCESS;
+
+err:
+	kfree_skb(skb);
+	return rc;
+}
+
+static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
+			 u16 *dgram_size, u16 *dgram_offset)
+{
+	struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
+	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
+	struct lowpan_addr_info info;
+
+	memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
+
+	*dgram_size = skb->len;
+	lowpan_header_compress(skb, ldev, &info.daddr, &info.saddr);
+	/* dgram_offset = (saved bytes after compression) + lowpan header len */
+	*dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb);
+
+	cb->type = IEEE802154_FC_TYPE_DATA;
+
+	if (info.daddr.mode == IEEE802154_ADDR_SHORT &&
+	    ieee802154_is_broadcast_short_addr(info.daddr.short_addr))
+		cb->ackreq = false;
+	else
+		cb->ackreq = wpan_dev->ackreq;
+
+	return wpan_dev_hard_header(skb, lowpan_802154_dev(ldev)->wdev,
+				    &info.daddr, &info.saddr, 0);
+}
+
+netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
+{
+	struct ieee802154_hdr wpan_hdr;
+	int max_single, ret;
+	u16 dgram_size, dgram_offset;
+
+	pr_debug("package xmit\n");
+
+	if (skb->protocol != htons(ETH_P_IPV6)) {
+		kfree_skb(skb);
+		return NET_XMIT_DROP;
+	}
+
+	WARN_ON_ONCE(skb->len > IPV6_MIN_MTU);
+
+	/* We must take a copy of the skb before we modify/replace the ipv6
+	 * header as the header could be used elsewhere
+	 */
+	if (unlikely(skb_headroom(skb) < ldev->needed_headroom ||
+		     skb_tailroom(skb) < ldev->needed_tailroom)) {
+		struct sk_buff *nskb;
+
+		nskb = skb_copy_expand(skb, ldev->needed_headroom,
+				       ldev->needed_tailroom, GFP_ATOMIC);
+		if (likely(nskb)) {
+			consume_skb(skb);
+			skb = nskb;
+		} else {
+			kfree_skb(skb);
+			return NET_XMIT_DROP;
+		}
+	} else {
+		skb = skb_unshare(skb, GFP_ATOMIC);
+		if (!skb)
+			return NET_XMIT_DROP;
+	}
+
+	ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
+	if (ret < 0) {
+		kfree_skb(skb);
+		return NET_XMIT_DROP;
+	}
+
+	if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) {
+		kfree_skb(skb);
+		return NET_XMIT_DROP;
+	}
+
+	max_single = ieee802154_max_payload(&wpan_hdr);
+
+	if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) {
+		skb->dev = lowpan_802154_dev(ldev)->wdev;
+		ldev->stats.tx_packets++;
+		ldev->stats.tx_bytes += dgram_size;
+		return dev_queue_xmit(skb);
+	} else {
+		netdev_tx_t rc;
+
+		pr_debug("frame is too big, fragmentation is needed\n");
+		rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size,
+					    dgram_offset);
+
+		return rc < 0 ? NET_XMIT_DROP : rc;
+	}
+}