net/ieee802154/6lowpan.h - kernel/msm-4.19 - Gitiles

 /*
  * 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.
  */

 #ifndef __6LOWPAN_H__
 #define __6LOWPAN_H__

 #define UIP_802154_SHORTADDR_LEN	2  /* compressed ipv6 address length */
 #define UIP_IPH_LEN			40 /* ipv6 fixed header size */
 #define UIP_PROTO_UDP			17 /* ipv6 next header value for UDP */
 #define UIP_FRAGH_LEN			8  /* ipv6 fragment header size */

 /*
  * ipv6 address based on mac
  * second bit-flip (Universe/Local) is done according RFC2464
  */
 #define is_addr_mac_addr_based(a, m) \
 	((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&	\
 	 (((a)->s6_addr[9])  == (m)[1]) &&		\
 	 (((a)->s6_addr[10]) == (m)[2]) &&		\
 	 (((a)->s6_addr[11]) == (m)[3]) &&		\
 	 (((a)->s6_addr[12]) == (m)[4]) &&		\
 	 (((a)->s6_addr[13]) == (m)[5]) &&		\
 	 (((a)->s6_addr[14]) == (m)[6]) &&		\
 	 (((a)->s6_addr[15]) == (m)[7]))

 /* ipv6 address is unspecified */
 #define is_addr_unspecified(a)		\
 	((((a)->s6_addr32[0]) == 0) &&	\
 	 (((a)->s6_addr32[1]) == 0) &&	\
 	 (((a)->s6_addr32[2]) == 0) &&	\
 	 (((a)->s6_addr32[3]) == 0))

 /* compare ipv6 addresses prefixes */
 #define ipaddr_prefixcmp(addr1, addr2, length) \
 	(memcmp(addr1, addr2, length >> 3) == 0)

 /* local link, i.e. FE80::/10 */
 #define is_addr_link_local(a) (((a)->s6_addr16[0]) == htons(0xFE80))

 /*
  * check whether we can compress the IID to 16 bits,
  * it's possible for unicast adresses with first 49 bits are zero only.
  */
 #define lowpan_is_iid_16_bit_compressable(a)	\
 	((((a)->s6_addr16[4]) == 0) &&		\
 	 (((a)->s6_addr[10]) == 0) &&		\
 	 (((a)->s6_addr[11]) == 0xff) &&	\
 	 (((a)->s6_addr[12]) == 0xfe) &&	\
 	 (((a)->s6_addr[13]) == 0))

 /* multicast address */
 #define is_addr_mcast(a) (((a)->s6_addr[0]) == 0xFF)

 /* check whether the 112-bit gid of the multicast address is mappable to: */

 /* 9 bits, for FF02::1 (all nodes) and FF02::2 (all routers) addresses only. */
 #define lowpan_is_mcast_addr_compressable(a)	\
 	((((a)->s6_addr16[1]) == 0) &&		\
 	 (((a)->s6_addr16[2]) == 0) &&		\
 	 (((a)->s6_addr16[3]) == 0) &&		\
 	 (((a)->s6_addr16[4]) == 0) &&		\
 	 (((a)->s6_addr16[5]) == 0) &&		\
 	 (((a)->s6_addr16[6]) == 0) &&		\
 	 (((a)->s6_addr[14])  == 0) &&		\
 	 ((((a)->s6_addr[15]) == 1) || (((a)->s6_addr[15]) == 2)))

 /* 48 bits, FFXX::00XX:XXXX:XXXX */
 #define lowpan_is_mcast_addr_compressable48(a)	\
 	((((a)->s6_addr16[1]) == 0) &&		\
 	 (((a)->s6_addr16[2]) == 0) &&		\
 	 (((a)->s6_addr16[3]) == 0) &&		\
 	 (((a)->s6_addr16[4]) == 0) &&		\
 	 (((a)->s6_addr[10]) == 0))

 /* 32 bits, FFXX::00XX:XXXX */
 #define lowpan_is_mcast_addr_compressable32(a)	\
 	((((a)->s6_addr16[1]) == 0) &&		\
 	 (((a)->s6_addr16[2]) == 0) &&		\
 	 (((a)->s6_addr16[3]) == 0) &&		\
 	 (((a)->s6_addr16[4]) == 0) &&		\
 	 (((a)->s6_addr16[5]) == 0) &&		\
 	 (((a)->s6_addr[12]) == 0))

 /* 8 bits, FF02::00XX */
 #define lowpan_is_mcast_addr_compressable8(a)	\
 	((((a)->s6_addr[1])  == 2) &&		\
 	 (((a)->s6_addr16[1]) == 0) &&		\
 	 (((a)->s6_addr16[2]) == 0) &&		\
 	 (((a)->s6_addr16[3]) == 0) &&		\
 	 (((a)->s6_addr16[4]) == 0) &&		\
 	 (((a)->s6_addr16[5]) == 0) &&		\
 	 (((a)->s6_addr16[6]) == 0) &&		\
 	 (((a)->s6_addr[14]) == 0))

 #define lowpan_is_addr_broadcast(a)	\
 	((((a)[0]) == 0xFF) &&	\
 	 (((a)[1]) == 0xFF) &&	\
 	 (((a)[2]) == 0xFF) &&	\
 	 (((a)[3]) == 0xFF) &&	\
 	 (((a)[4]) == 0xFF) &&	\
 	 (((a)[5]) == 0xFF) &&	\
 	 (((a)[6]) == 0xFF) &&	\
 	 (((a)[7]) == 0xFF))

 #define LOWPAN_DISPATCH_IPV6	0x41 /* 01000001 = 65 */
 #define LOWPAN_DISPATCH_HC1	0x42 /* 01000010 = 66 */
 #define LOWPAN_DISPATCH_IPHC	0x60 /* 011xxxxx = ... */
 #define LOWPAN_DISPATCH_FRAG1	0xc0 /* 11000xxx */
 #define LOWPAN_DISPATCH_FRAGN	0xe0 /* 11100xxx */

 #define LOWPAN_DISPATCH_MASK	0xf8 /* 11111000 */

 #define LOWPAN_FRAG_TIMEOUT	(HZ * 60)	/* time-out 60 sec */

 #define LOWPAN_FRAG1_HEAD_SIZE	0x4
 #define LOWPAN_FRAGN_HEAD_SIZE	0x5

 /*
  * According IEEE802.15.4 standard:
  *   - MTU is 127 octets
  *   - maximum MHR size is 37 octets
  *   - MFR size is 2 octets
  *
  * so minimal payload size that we may guarantee is:
  *   MTU - MHR - MFR = 88 octets
  */
 #define LOWPAN_FRAG_SIZE	88

 /*
  * Values of fields within the IPHC encoding first byte
  * (C stands for compressed and I for inline)
  */
 #define LOWPAN_IPHC_TF		0x18

 #define LOWPAN_IPHC_FL_C	0x10
 #define LOWPAN_IPHC_TC_C	0x08
 #define LOWPAN_IPHC_NH_C	0x04
 #define LOWPAN_IPHC_TTL_1	0x01
 #define LOWPAN_IPHC_TTL_64	0x02
 #define LOWPAN_IPHC_TTL_255	0x03
 #define LOWPAN_IPHC_TTL_I	0x00


 /* Values of fields within the IPHC encoding second byte */
 #define LOWPAN_IPHC_CID		0x80

 #define LOWPAN_IPHC_ADDR_00	0x00
 #define LOWPAN_IPHC_ADDR_01	0x01
 #define LOWPAN_IPHC_ADDR_02	0x02
 #define LOWPAN_IPHC_ADDR_03	0x03

 #define LOWPAN_IPHC_SAC		0x40
 #define LOWPAN_IPHC_SAM		0x30

 #define LOWPAN_IPHC_SAM_BIT	4

 #define LOWPAN_IPHC_M		0x08
 #define LOWPAN_IPHC_DAC		0x04
 #define LOWPAN_IPHC_DAM_00	0x00
 #define LOWPAN_IPHC_DAM_01	0x01
 #define LOWPAN_IPHC_DAM_10	0x02
 #define LOWPAN_IPHC_DAM_11	0x03

 #define LOWPAN_IPHC_DAM_BIT	0
 /*
  * LOWPAN_UDP encoding (works together with IPHC)
  */
 #define LOWPAN_NHC_UDP_MASK		0xF8
 #define LOWPAN_NHC_UDP_ID		0xF0
 #define LOWPAN_NHC_UDP_CHECKSUMC	0x04
 #define LOWPAN_NHC_UDP_CHECKSUMI	0x00

 #define LOWPAN_NHC_UDP_4BIT_PORT	0xF0B0
 #define LOWPAN_NHC_UDP_4BIT_MASK	0xFFF0
 #define LOWPAN_NHC_UDP_8BIT_PORT	0xF000
 #define LOWPAN_NHC_UDP_8BIT_MASK	0xFF00

 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
 #define LOWPAN_NHC_UDP_CS_P_00	0xF0 /* all inline */
 #define LOWPAN_NHC_UDP_CS_P_01	0xF1 /* source 16bit inline,
 					dest = 0xF0 + 8 bit inline */
 #define LOWPAN_NHC_UDP_CS_P_10	0xF2 /* source = 0xF0 + 8bit inline,
 					dest = 16 bit inline */
 #define LOWPAN_NHC_UDP_CS_P_11	0xF3 /* source & dest = 0xF0B + 4bit inline */

 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 {
 	if (unlikely(!pskb_may_pull(skb, 1)))
 		return -EINVAL;

 	*val = skb->data[0];
 	skb_pull(skb, 1);

 	return 0;
 }

 static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
 {
 	if (unlikely(!pskb_may_pull(skb, 2)))
 		return -EINVAL;

 	*val = (skb->data[0] << 8) | skb->data[1];
 	skb_pull(skb, 2);

 	return 0;
 }

 static inline bool lowpan_fetch_skb(struct sk_buff *skb,
 		void *data, const unsigned int len)
 {
 	if (unlikely(!pskb_may_pull(skb, len)))
 		return true;

 	skb_copy_from_linear_data(skb, data, len);
 	skb_pull(skb, len);

 	return false;
 }

 typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);

 int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
 		const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
 		const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
 		u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 			unsigned short type, const void *_daddr,
 			const void *_saddr, unsigned int len);

 #endif /* __6LOWPAN_H__ */
	/*
	* 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.
	*/

	#ifndef __6LOWPAN_H__
	#define __6LOWPAN_H__

	#define UIP_802154_SHORTADDR_LEN 2 /* compressed ipv6 address length */
	#define UIP_IPH_LEN 40 /* ipv6 fixed header size */
	#define UIP_PROTO_UDP 17 /* ipv6 next header value for UDP */
	#define UIP_FRAGH_LEN 8 /* ipv6 fragment header size */

	/*
	* ipv6 address based on mac
	* second bit-flip (Universe/Local) is done according RFC2464
	*/
	#define is_addr_mac_addr_based(a, m) \
	((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \
	(((a)->s6_addr[9]) == (m)[1]) && \
	(((a)->s6_addr[10]) == (m)[2]) && \
	(((a)->s6_addr[11]) == (m)[3]) && \
	(((a)->s6_addr[12]) == (m)[4]) && \
	(((a)->s6_addr[13]) == (m)[5]) && \
	(((a)->s6_addr[14]) == (m)[6]) && \
	(((a)->s6_addr[15]) == (m)[7]))

	/* ipv6 address is unspecified */
	#define is_addr_unspecified(a) \
	((((a)->s6_addr32[0]) == 0) && \
	(((a)->s6_addr32[1]) == 0) && \
	(((a)->s6_addr32[2]) == 0) && \
	(((a)->s6_addr32[3]) == 0))

	/* compare ipv6 addresses prefixes */
	#define ipaddr_prefixcmp(addr1, addr2, length) \
	(memcmp(addr1, addr2, length >> 3) == 0)

	/* local link, i.e. FE80::/10 */
	#define is_addr_link_local(a) (((a)->s6_addr16[0]) == htons(0xFE80))

	/*
	* check whether we can compress the IID to 16 bits,
	* it's possible for unicast adresses with first 49 bits are zero only.
	*/
	#define lowpan_is_iid_16_bit_compressable(a) \
	((((a)->s6_addr16[4]) == 0) && \
	(((a)->s6_addr[10]) == 0) && \
	(((a)->s6_addr[11]) == 0xff) && \
	(((a)->s6_addr[12]) == 0xfe) && \
	(((a)->s6_addr[13]) == 0))

	/* multicast address */
	#define is_addr_mcast(a) (((a)->s6_addr[0]) == 0xFF)

	/* check whether the 112-bit gid of the multicast address is mappable to: */

	/* 9 bits, for FF02::1 (all nodes) and FF02::2 (all routers) addresses only. */
	#define lowpan_is_mcast_addr_compressable(a) \
	((((a)->s6_addr16[1]) == 0) && \
	(((a)->s6_addr16[2]) == 0) && \
	(((a)->s6_addr16[3]) == 0) && \
	(((a)->s6_addr16[4]) == 0) && \
	(((a)->s6_addr16[5]) == 0) && \
	(((a)->s6_addr16[6]) == 0) && \
	(((a)->s6_addr[14]) == 0) && \
	((((a)->s6_addr[15]) == 1) \|\| (((a)->s6_addr[15]) == 2)))

	/* 48 bits, FFXX::00XX:XXXX:XXXX */
	#define lowpan_is_mcast_addr_compressable48(a) \
	((((a)->s6_addr16[1]) == 0) && \
	(((a)->s6_addr16[2]) == 0) && \
	(((a)->s6_addr16[3]) == 0) && \
	(((a)->s6_addr16[4]) == 0) && \
	(((a)->s6_addr[10]) == 0))

	/* 32 bits, FFXX::00XX:XXXX */
	#define lowpan_is_mcast_addr_compressable32(a) \
	((((a)->s6_addr16[1]) == 0) && \
	(((a)->s6_addr16[2]) == 0) && \
	(((a)->s6_addr16[3]) == 0) && \
	(((a)->s6_addr16[4]) == 0) && \
	(((a)->s6_addr16[5]) == 0) && \
	(((a)->s6_addr[12]) == 0))

	/* 8 bits, FF02::00XX */
	#define lowpan_is_mcast_addr_compressable8(a) \
	((((a)->s6_addr[1]) == 2) && \
	(((a)->s6_addr16[1]) == 0) && \
	(((a)->s6_addr16[2]) == 0) && \
	(((a)->s6_addr16[3]) == 0) && \
	(((a)->s6_addr16[4]) == 0) && \
	(((a)->s6_addr16[5]) == 0) && \
	(((a)->s6_addr16[6]) == 0) && \
	(((a)->s6_addr[14]) == 0))

	#define lowpan_is_addr_broadcast(a) \
	((((a)[0]) == 0xFF) && \
	(((a)[1]) == 0xFF) && \
	(((a)[2]) == 0xFF) && \
	(((a)[3]) == 0xFF) && \
	(((a)[4]) == 0xFF) && \
	(((a)[5]) == 0xFF) && \
	(((a)[6]) == 0xFF) && \
	(((a)[7]) == 0xFF))

	#define LOWPAN_DISPATCH_IPV6 0x41 /* 01000001 = 65 */
	#define LOWPAN_DISPATCH_HC1 0x42 /* 01000010 = 66 */
	#define LOWPAN_DISPATCH_IPHC 0x60 /* 011xxxxx = ... */
	#define LOWPAN_DISPATCH_FRAG1 0xc0 /* 11000xxx */
	#define LOWPAN_DISPATCH_FRAGN 0xe0 /* 11100xxx */

	#define LOWPAN_DISPATCH_MASK 0xf8 /* 11111000 */

	#define LOWPAN_FRAG_TIMEOUT (HZ * 60) /* time-out 60 sec */

	#define LOWPAN_FRAG1_HEAD_SIZE 0x4
	#define LOWPAN_FRAGN_HEAD_SIZE 0x5

	/*
	* According IEEE802.15.4 standard:
	* - MTU is 127 octets
	* - maximum MHR size is 37 octets
	* - MFR size is 2 octets
	*
	* so minimal payload size that we may guarantee is:
	* MTU - MHR - MFR = 88 octets
	*/
	#define LOWPAN_FRAG_SIZE 88

	/*
	* Values of fields within the IPHC encoding first byte
	* (C stands for compressed and I for inline)
	*/
	#define LOWPAN_IPHC_TF 0x18

	#define LOWPAN_IPHC_FL_C 0x10
	#define LOWPAN_IPHC_TC_C 0x08
	#define LOWPAN_IPHC_NH_C 0x04
	#define LOWPAN_IPHC_TTL_1 0x01
	#define LOWPAN_IPHC_TTL_64 0x02
	#define LOWPAN_IPHC_TTL_255 0x03
	#define LOWPAN_IPHC_TTL_I 0x00


	/* Values of fields within the IPHC encoding second byte */
	#define LOWPAN_IPHC_CID 0x80

	#define LOWPAN_IPHC_ADDR_00 0x00
	#define LOWPAN_IPHC_ADDR_01 0x01
	#define LOWPAN_IPHC_ADDR_02 0x02
	#define LOWPAN_IPHC_ADDR_03 0x03

	#define LOWPAN_IPHC_SAC 0x40
	#define LOWPAN_IPHC_SAM 0x30

	#define LOWPAN_IPHC_SAM_BIT 4

	#define LOWPAN_IPHC_M 0x08
	#define LOWPAN_IPHC_DAC 0x04
	#define LOWPAN_IPHC_DAM_00 0x00
	#define LOWPAN_IPHC_DAM_01 0x01
	#define LOWPAN_IPHC_DAM_10 0x02
	#define LOWPAN_IPHC_DAM_11 0x03

	#define LOWPAN_IPHC_DAM_BIT 0
	/*
	* LOWPAN_UDP encoding (works together with IPHC)
	*/
	#define LOWPAN_NHC_UDP_MASK 0xF8
	#define LOWPAN_NHC_UDP_ID 0xF0
	#define LOWPAN_NHC_UDP_CHECKSUMC 0x04
	#define LOWPAN_NHC_UDP_CHECKSUMI 0x00

	#define LOWPAN_NHC_UDP_4BIT_PORT 0xF0B0
	#define LOWPAN_NHC_UDP_4BIT_MASK 0xFFF0
	#define LOWPAN_NHC_UDP_8BIT_PORT 0xF000
	#define LOWPAN_NHC_UDP_8BIT_MASK 0xFF00

	/* values for port compression, _with checksum_ ie bit 5 set to 0 */
	#define LOWPAN_NHC_UDP_CS_P_00 0xF0 /* all inline */
	#define LOWPAN_NHC_UDP_CS_P_01 0xF1 /* source 16bit inline,
	dest = 0xF0 + 8 bit inline */
	#define LOWPAN_NHC_UDP_CS_P_10 0xF2 /* source = 0xF0 + 8bit inline,
	dest = 16 bit inline */
	#define LOWPAN_NHC_UDP_CS_P_11 0xF3 /* source & dest = 0xF0B + 4bit inline */

	static inline int lowpan_fetch_skb_u8(struct sk_buff skb, u8 val)
	{
	if (unlikely(!pskb_may_pull(skb, 1)))
	return -EINVAL;

	*val = skb->data[0];
	skb_pull(skb, 1);

	return 0;
	}

	static inline int lowpan_fetch_skb_u16(struct sk_buff skb, u16 val)
	{
	if (unlikely(!pskb_may_pull(skb, 2)))
	return -EINVAL;

	*val = (skb->data[0] << 8) \| skb->data[1];
	skb_pull(skb, 2);

	return 0;
	}

	static inline bool lowpan_fetch_skb(struct sk_buff *skb,
	void *data, const unsigned int len)
	{
	if (unlikely(!pskb_may_pull(skb, len)))
	return true;

	skb_copy_from_linear_data(skb, data, len);
	skb_pull(skb, len);

	return false;
	}

	typedef int (skb_delivery_cb)(struct sk_buff skb, struct net_device *dev);

	int lowpan_process_data(struct sk_buff skb, struct net_device dev,
	const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
	const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
	u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
	int lowpan_header_compress(struct sk_buff skb, struct net_device dev,
	unsigned short type, const void *_daddr,
	const void *_saddr, unsigned int len);

	#endif /* __6LOWPAN_H__ */