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v4.6
  1/*
  2 * Copyright 2011, Siemens AG
  3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
  4 */
  5
  6/*
  7 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
  8 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
  9 *
 10 * This program is free software; you can redistribute it and/or modify
 11 * it under the terms of the GNU General Public License version 2
 12 * as published by the Free Software Foundation.
 13 *
 14 * This program is distributed in the hope that it will be useful,
 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17 * GNU General Public License for more details.
 18 *
 19 * You should have received a copy of the GNU General Public License along
 20 * with this program; if not, write to the Free Software Foundation, Inc.,
 21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 22 */
 23
 24/* Jon's code is based on 6lowpan implementation for Contiki which is:
 25 * Copyright (c) 2008, Swedish Institute of Computer Science.
 26 * All rights reserved.
 27 *
 28 * Redistribution and use in source and binary forms, with or without
 29 * modification, are permitted provided that the following conditions
 30 * are met:
 31 * 1. Redistributions of source code must retain the above copyright
 32 *    notice, this list of conditions and the following disclaimer.
 33 * 2. Redistributions in binary form must reproduce the above copyright
 34 *    notice, this list of conditions and the following disclaimer in the
 35 *    documentation and/or other materials provided with the distribution.
 36 * 3. Neither the name of the Institute nor the names of its contributors
 37 *    may be used to endorse or promote products derived from this software
 38 *    without specific prior written permission.
 39 *
 40 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 43 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 50 * SUCH DAMAGE.
 51 */
 52
 53#ifndef __6LOWPAN_H__
 54#define __6LOWPAN_H__
 55
 56#include <linux/debugfs.h>
 57
 58#include <net/ipv6.h>
 59#include <net/net_namespace.h>
 60
 
 
 
 61#define EUI64_ADDR_LEN		8
 62
 63#define LOWPAN_NHC_MAX_ID_LEN	1
 64/* Maximum next header compression length which we currently support inclusive
 65 * possible inline data.
 66 */
 67#define LOWPAN_NHC_MAX_HDR_LEN	(sizeof(struct udphdr))
 68/* Max IPHC Header len without IPv6 hdr specific inline data.
 69 * Useful for getting the "extra" bytes we need at worst case compression.
 70 *
 71 * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
 72 */
 73#define LOWPAN_IPHC_MAX_HEADER_LEN	(2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
 74/* Maximum worst case IPHC header buffer size */
 75#define LOWPAN_IPHC_MAX_HC_BUF_LEN	(sizeof(struct ipv6hdr) +	\
 76					 LOWPAN_IPHC_MAX_HEADER_LEN +	\
 77					 LOWPAN_NHC_MAX_HDR_LEN)
 78/* SCI/DCI is 4 bit width, so we have maximum 16 entries */
 79#define LOWPAN_IPHC_CTX_TABLE_SIZE	(1 << 4)
 80
 81#define LOWPAN_DISPATCH_IPV6		0x41 /* 01000001 = 65 */
 82#define LOWPAN_DISPATCH_IPHC		0x60 /* 011xxxxx = ... */
 83#define LOWPAN_DISPATCH_IPHC_MASK	0xe0
 84
 85static inline bool lowpan_is_ipv6(u8 dispatch)
 86{
 87	return dispatch == LOWPAN_DISPATCH_IPV6;
 88}
 89
 90static inline bool lowpan_is_iphc(u8 dispatch)
 91{
 92	return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
 93}
 94
 95#define LOWPAN_PRIV_SIZE(llpriv_size)	\
 96	(sizeof(struct lowpan_priv) + llpriv_size)
 97
 98enum lowpan_lltypes {
 99	LOWPAN_LLTYPE_BTLE,
100	LOWPAN_LLTYPE_IEEE802154,
101};
102
103enum lowpan_iphc_ctx_flags {
104	LOWPAN_IPHC_CTX_FLAG_ACTIVE,
105	LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
106};
107
108struct lowpan_iphc_ctx {
109	u8 id;
110	struct in6_addr pfx;
111	u8 plen;
112	unsigned long flags;
113};
114
115struct lowpan_iphc_ctx_table {
116	spinlock_t lock;
117	const struct lowpan_iphc_ctx_ops *ops;
118	struct lowpan_iphc_ctx table[LOWPAN_IPHC_CTX_TABLE_SIZE];
119};
120
121static inline bool lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx *ctx)
122{
123	return test_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
124}
125
126static inline bool
127lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
128{
129	return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
130}
131
132struct lowpan_priv {
133	enum lowpan_lltypes lltype;
134	struct dentry *iface_debugfs;
135	struct lowpan_iphc_ctx_table ctx;
136
137	/* must be last */
138	u8 priv[0] __aligned(sizeof(void *));
 
 
 
 
139};
140
141static inline
142struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 
 
 
 
 
 
143{
144	return netdev_priv(dev);
145}
146
 
 
 
 
 
 
 
 
 
 
 
 
147struct lowpan_802154_cb {
148	u16 d_tag;
149	unsigned int d_size;
150	u8 d_offset;
151};
152
153static inline
154struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
155{
156	BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
157	return (struct lowpan_802154_cb *)skb->cb;
158}
159
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
160#ifdef DEBUG
161/* print data in line */
162static inline void raw_dump_inline(const char *caller, char *msg,
163				   const unsigned char *buf, int len)
164{
165	if (msg)
166		pr_debug("%s():%s: ", caller, msg);
167
168	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
169}
170
171/* print data in a table format:
172 *
173 * addr: xx xx xx xx xx xx
174 * addr: xx xx xx xx xx xx
175 * ...
176 */
177static inline void raw_dump_table(const char *caller, char *msg,
178				  const unsigned char *buf, int len)
179{
180	if (msg)
181		pr_debug("%s():%s:\n", caller, msg);
182
183	print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
184}
185#else
186static inline void raw_dump_table(const char *caller, char *msg,
187				  const unsigned char *buf, int len) { }
188static inline void raw_dump_inline(const char *caller, char *msg,
189				   const unsigned char *buf, int len) { }
190#endif
191
192/**
193 * lowpan_fetch_skb - getting inline data from 6LoWPAN header
194 *
195 * This function will pull data from sk buffer and put it into data to
196 * remove the 6LoWPAN inline data. This function returns true if the
197 * sk buffer is too small to pull the amount of data which is specified
198 * by len.
199 *
200 * @skb: the buffer where the inline data should be pulled from.
201 * @data: destination buffer for the inline data.
202 * @len: amount of data which should be pulled in bytes.
203 */
204static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
205				    unsigned int len)
206{
207	if (unlikely(!pskb_may_pull(skb, len)))
208		return true;
209
210	skb_copy_from_linear_data(skb, data, len);
211	skb_pull(skb, len);
212
213	return false;
 
 
 
 
 
 
214}
215
216static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
217				       const size_t len)
218{
219	memcpy(*hc_ptr, data, len);
220	*hc_ptr += len;
221}
222
223int lowpan_register_netdevice(struct net_device *dev,
224			      enum lowpan_lltypes lltype);
225int lowpan_register_netdev(struct net_device *dev,
226			   enum lowpan_lltypes lltype);
227void lowpan_unregister_netdevice(struct net_device *dev);
228void lowpan_unregister_netdev(struct net_device *dev);
229
230/**
231 * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
232 *
233 * This function replaces the IPHC 6LoWPAN header which should be pointed at
234 * skb->data and skb_network_header, with the IPv6 header.
235 * It would be nice that the caller have the necessary headroom of IPv6 header
236 * and greatest Transport layer header, this would reduce the overhead for
237 * reallocate headroom.
238 *
239 * @skb: the buffer which should be manipulate.
240 * @dev: the lowpan net device pointer.
241 * @daddr: destination lladdr of mac header which is used for compression
242 *	methods.
243 * @saddr: source lladdr of mac header which is used for compression
244 *	methods.
245 */
246int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
247			     const void *daddr, const void *saddr);
248
249/**
250 * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
251 *
252 * This function replaces the IPv6 header which should be pointed at
253 * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
254 * The caller need to be sure that the sk buffer is not shared and at have
255 * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
256 * which is the IPHC "more bytes than IPv6 header" at worst case.
257 *
258 * @skb: the buffer which should be manipulate.
259 * @dev: the lowpan net device pointer.
260 * @daddr: destination lladdr of mac header which is used for compression
261 *	methods.
262 * @saddr: source lladdr of mac header which is used for compression
263 *	methods.
264 */
265int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
266			   const void *daddr, const void *saddr);
267
268#endif /* __6LOWPAN_H__ */
v6.9.4
  1/*
  2 * Copyright 2011, Siemens AG
  3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
  4 */
  5
  6/*
  7 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
  8 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
  9 *
 10 * This program is free software; you can redistribute it and/or modify
 11 * it under the terms of the GNU General Public License version 2
 12 * as published by the Free Software Foundation.
 13 *
 14 * This program is distributed in the hope that it will be useful,
 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17 * GNU General Public License for more details.
 18 *
 19 * You should have received a copy of the GNU General Public License along
 20 * with this program; if not, write to the Free Software Foundation, Inc.,
 21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 22 */
 23
 24/* Jon's code is based on 6lowpan implementation for Contiki which is:
 25 * Copyright (c) 2008, Swedish Institute of Computer Science.
 26 * All rights reserved.
 27 *
 28 * Redistribution and use in source and binary forms, with or without
 29 * modification, are permitted provided that the following conditions
 30 * are met:
 31 * 1. Redistributions of source code must retain the above copyright
 32 *    notice, this list of conditions and the following disclaimer.
 33 * 2. Redistributions in binary form must reproduce the above copyright
 34 *    notice, this list of conditions and the following disclaimer in the
 35 *    documentation and/or other materials provided with the distribution.
 36 * 3. Neither the name of the Institute nor the names of its contributors
 37 *    may be used to endorse or promote products derived from this software
 38 *    without specific prior written permission.
 39 *
 40 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 43 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 50 * SUCH DAMAGE.
 51 */
 52
 53#ifndef __6LOWPAN_H__
 54#define __6LOWPAN_H__
 55
 56#include <linux/debugfs.h>
 57
 58#include <net/ipv6.h>
 59#include <net/net_namespace.h>
 60
 61/* special link-layer handling */
 62#include <net/mac802154.h>
 63
 64#define EUI64_ADDR_LEN		8
 65
 66#define LOWPAN_NHC_MAX_ID_LEN	1
 67/* Maximum next header compression length which we currently support inclusive
 68 * possible inline data.
 69 */
 70#define LOWPAN_NHC_MAX_HDR_LEN	(sizeof(struct udphdr))
 71/* Max IPHC Header len without IPv6 hdr specific inline data.
 72 * Useful for getting the "extra" bytes we need at worst case compression.
 73 *
 74 * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
 75 */
 76#define LOWPAN_IPHC_MAX_HEADER_LEN	(2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
 77/* Maximum worst case IPHC header buffer size */
 78#define LOWPAN_IPHC_MAX_HC_BUF_LEN	(sizeof(struct ipv6hdr) +	\
 79					 LOWPAN_IPHC_MAX_HEADER_LEN +	\
 80					 LOWPAN_NHC_MAX_HDR_LEN)
 81/* SCI/DCI is 4 bit width, so we have maximum 16 entries */
 82#define LOWPAN_IPHC_CTX_TABLE_SIZE	(1 << 4)
 83
 84#define LOWPAN_DISPATCH_IPV6		0x41 /* 01000001 = 65 */
 85#define LOWPAN_DISPATCH_IPHC		0x60 /* 011xxxxx = ... */
 86#define LOWPAN_DISPATCH_IPHC_MASK	0xe0
 87
 88static inline bool lowpan_is_ipv6(u8 dispatch)
 89{
 90	return dispatch == LOWPAN_DISPATCH_IPV6;
 91}
 92
 93static inline bool lowpan_is_iphc(u8 dispatch)
 94{
 95	return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
 96}
 97
 98#define LOWPAN_PRIV_SIZE(llpriv_size)	\
 99	(sizeof(struct lowpan_dev) + llpriv_size)
100
101enum lowpan_lltypes {
102	LOWPAN_LLTYPE_BTLE,
103	LOWPAN_LLTYPE_IEEE802154,
104};
105
106enum lowpan_iphc_ctx_flags {
107	LOWPAN_IPHC_CTX_FLAG_ACTIVE,
108	LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
109};
110
111struct lowpan_iphc_ctx {
112	u8 id;
113	struct in6_addr pfx;
114	u8 plen;
115	unsigned long flags;
116};
117
118struct lowpan_iphc_ctx_table {
119	spinlock_t lock;
120	const struct lowpan_iphc_ctx_ops *ops;
121	struct lowpan_iphc_ctx table[LOWPAN_IPHC_CTX_TABLE_SIZE];
122};
123
124static inline bool lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx *ctx)
125{
126	return test_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
127}
128
129static inline bool
130lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
131{
132	return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
133}
134
135struct lowpan_dev {
136	enum lowpan_lltypes lltype;
137	struct dentry *iface_debugfs;
138	struct lowpan_iphc_ctx_table ctx;
139
140	/* must be last */
141	u8 priv[] __aligned(sizeof(void *));
142};
143
144struct lowpan_802154_neigh {
145	__le16 short_addr;
146};
147
148static inline
149struct lowpan_802154_neigh *lowpan_802154_neigh(void *neigh_priv)
150{
151	return neigh_priv;
152}
153
154static inline
155struct lowpan_dev *lowpan_dev(const struct net_device *dev)
156{
157	return netdev_priv(dev);
158}
159
160/* private device info */
161struct lowpan_802154_dev {
162	struct net_device	*wdev; /* wpan device ptr */
163	u16			fragment_tag;
164};
165
166static inline struct
167lowpan_802154_dev *lowpan_802154_dev(const struct net_device *dev)
168{
169	return (struct lowpan_802154_dev *)lowpan_dev(dev)->priv;
170}
171
172struct lowpan_802154_cb {
173	u16 d_tag;
174	unsigned int d_size;
175	u8 d_offset;
176};
177
178static inline
179struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
180{
181	BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
182	return (struct lowpan_802154_cb *)skb->cb;
183}
184
185static inline void lowpan_iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
186						       const void *lladdr)
187{
188	/* fe:80::XXXX:XXXX:XXXX:XXXX
189	 *        \_________________/
190	 *              hwaddr
191	 */
192	ipaddr->s6_addr[0] = 0xFE;
193	ipaddr->s6_addr[1] = 0x80;
194	memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
195	/* second bit-flip (Universe/Local)
196	 * is done according RFC2464
197	 */
198	ipaddr->s6_addr[8] ^= 0x02;
199}
200
201static inline void lowpan_iphc_uncompress_eui48_lladdr(struct in6_addr *ipaddr,
202						       const void *lladdr)
203{
204	/* fe:80::XXXX:XXff:feXX:XXXX
205	 *        \_________________/
206	 *              hwaddr
207	 */
208	ipaddr->s6_addr[0] = 0xFE;
209	ipaddr->s6_addr[1] = 0x80;
210	memcpy(&ipaddr->s6_addr[8], lladdr, 3);
211	ipaddr->s6_addr[11] = 0xFF;
212	ipaddr->s6_addr[12] = 0xFE;
213	memcpy(&ipaddr->s6_addr[13], lladdr + 3, 3);
214}
215
216#ifdef DEBUG
217/* print data in line */
218static inline void raw_dump_inline(const char *caller, char *msg,
219				   const unsigned char *buf, int len)
220{
221	if (msg)
222		pr_debug("%s():%s: ", caller, msg);
223
224	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
225}
226
227/* print data in a table format:
228 *
229 * addr: xx xx xx xx xx xx
230 * addr: xx xx xx xx xx xx
231 * ...
232 */
233static inline void raw_dump_table(const char *caller, char *msg,
234				  const unsigned char *buf, int len)
235{
236	if (msg)
237		pr_debug("%s():%s:\n", caller, msg);
238
239	print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
240}
241#else
242static inline void raw_dump_table(const char *caller, char *msg,
243				  const unsigned char *buf, int len) { }
244static inline void raw_dump_inline(const char *caller, char *msg,
245				   const unsigned char *buf, int len) { }
246#endif
247
248/**
249 * lowpan_fetch_skb - getting inline data from 6LoWPAN header
250 *
251 * This function will pull data from sk buffer and put it into data to
252 * remove the 6LoWPAN inline data. This function returns true if the
253 * sk buffer is too small to pull the amount of data which is specified
254 * by len.
255 *
256 * @skb: the buffer where the inline data should be pulled from.
257 * @data: destination buffer for the inline data.
258 * @len: amount of data which should be pulled in bytes.
259 */
260static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
261				    unsigned int len)
262{
263	if (unlikely(!pskb_may_pull(skb, len)))
264		return true;
265
266	skb_copy_from_linear_data(skb, data, len);
267	skb_pull(skb, len);
268
269	return false;
270}
271
272static inline bool lowpan_802154_is_valid_src_short_addr(__le16 addr)
273{
274	/* First bit of addr is multicast, reserved or 802.15.4 specific */
275	return !(addr & cpu_to_le16(0x8000));
276}
277
278static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
279				       const size_t len)
280{
281	memcpy(*hc_ptr, data, len);
282	*hc_ptr += len;
283}
284
285int lowpan_register_netdevice(struct net_device *dev,
286			      enum lowpan_lltypes lltype);
287int lowpan_register_netdev(struct net_device *dev,
288			   enum lowpan_lltypes lltype);
289void lowpan_unregister_netdevice(struct net_device *dev);
290void lowpan_unregister_netdev(struct net_device *dev);
291
292/**
293 * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
294 *
295 * This function replaces the IPHC 6LoWPAN header which should be pointed at
296 * skb->data and skb_network_header, with the IPv6 header.
297 * It would be nice that the caller have the necessary headroom of IPv6 header
298 * and greatest Transport layer header, this would reduce the overhead for
299 * reallocate headroom.
300 *
301 * @skb: the buffer which should be manipulate.
302 * @dev: the lowpan net device pointer.
303 * @daddr: destination lladdr of mac header which is used for compression
304 *	methods.
305 * @saddr: source lladdr of mac header which is used for compression
306 *	methods.
307 */
308int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
309			     const void *daddr, const void *saddr);
310
311/**
312 * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
313 *
314 * This function replaces the IPv6 header which should be pointed at
315 * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
316 * The caller need to be sure that the sk buffer is not shared and at have
317 * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
318 * which is the IPHC "more bytes than IPv6 header" at worst case.
319 *
320 * @skb: the buffer which should be manipulate.
321 * @dev: the lowpan net device pointer.
322 * @daddr: destination lladdr of mac header which is used for compression
323 *	methods.
324 * @saddr: source lladdr of mac header which is used for compression
325 *	methods.
326 */
327int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
328			   const void *daddr, const void *saddr);
329
330#endif /* __6LOWPAN_H__ */