include/net/6lowpan.h - kernel/msm-4.9 - 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__

 #include <net/ipv6.h>
 #include <net/net_namespace.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]))

 /*
  * 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))

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

 /* 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

 /*
  * 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 */
 #define LOWPAN_NHC_UDP_CS_C	0x04 /* checksum elided */

 #define LOWPAN_PRIV_SIZE(llpriv_size)	\
 	(sizeof(struct lowpan_priv) + llpriv_size)

 enum lowpan_lltypes {
 	LOWPAN_LLTYPE_BTLE,
 	LOWPAN_LLTYPE_IEEE802154,
 };

 struct lowpan_priv {
 	enum lowpan_lltypes lltype;

 	/* must be last */
 	u8 priv[0] __aligned(sizeof(void *));
 };

 static inline
 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 {
 	return netdev_priv(dev);
 }

 #ifdef DEBUG
 /* print data in line */
 static inline void raw_dump_inline(const char *caller, char *msg,
 				   unsigned char *buf, int len)
 {
 	if (msg)
 		pr_debug("%s():%s: ", caller, msg);

 	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 }

 /* print data in a table format:
  *
  * addr: xx xx xx xx xx xx
  * addr: xx xx xx xx xx xx
  * ...
  */
 static inline void raw_dump_table(const char *caller, char *msg,
 				  unsigned char *buf, int len)
 {
 	if (msg)
 		pr_debug("%s():%s:\n", caller, msg);

 	print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 }
 #else
 static inline void raw_dump_table(const char *caller, char *msg,
 				  unsigned char *buf, int len) { }
 static inline void raw_dump_inline(const char *caller, char *msg,
 				   unsigned char *buf, int len) { }
 #endif

 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 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;
 }

 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 				       const size_t len)
 {
 	memcpy(*hc_ptr, data, len);
 	*hc_ptr += len;
 }

 static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
 {
 	static const u8 addr_sizes[] = {
 		[LOWPAN_IPHC_ADDR_00] = 16,
 		[LOWPAN_IPHC_ADDR_01] = 8,
 		[LOWPAN_IPHC_ADDR_02] = 2,
 		[LOWPAN_IPHC_ADDR_03] = 0,
 	};
 	return addr_sizes[addr_mode];
 }

 static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
 {
 	u8 ret = 1;

 	if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 		*uncomp_header += sizeof(struct udphdr);

 		switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
 		case LOWPAN_NHC_UDP_CS_P_00:
 			ret += 4;
 			break;
 		case LOWPAN_NHC_UDP_CS_P_01:
 		case LOWPAN_NHC_UDP_CS_P_10:
 			ret += 3;
 			break;
 		case LOWPAN_NHC_UDP_CS_P_11:
 			ret++;
 			break;
 		default:
 			break;
 		}

 		if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
 			ret += 2;
 	}

 	return ret;
 }

 /**
  *	lowpan_uncompress_size - returns skb->len size with uncompressed header
  *	@skb: sk_buff with 6lowpan header inside
  *	@datagram_offset: optional to get the datagram_offset value
  *
  *	Returns the skb->len with uncompressed header
  */
 static inline u16
 lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
 {
 	u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
 	u8 iphc0, iphc1, h_enc;

 	iphc0 = skb_network_header(skb)[0];
 	iphc1 = skb_network_header(skb)[1];

 	switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 	case 0:
 		ret += 4;
 		break;
 	case 1:
 		ret += 3;
 		break;
 	case 2:
 		ret++;
 		break;
 	default:
 		break;
 	}

 	if (!(iphc0 & LOWPAN_IPHC_NH_C))
 		ret++;

 	if (!(iphc0 & 0x03))
 		ret++;

 	ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
 				     LOWPAN_IPHC_SAM_BIT);

 	if (iphc1 & LOWPAN_IPHC_M) {
 		switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
 			LOWPAN_IPHC_DAM_BIT) {
 		case LOWPAN_IPHC_DAM_00:
 			ret += 16;
 			break;
 		case LOWPAN_IPHC_DAM_01:
 			ret += 6;
 			break;
 		case LOWPAN_IPHC_DAM_10:
 			ret += 4;
 			break;
 		case LOWPAN_IPHC_DAM_11:
 			ret++;
 			break;
 		default:
 			break;
 		}
 	} else {
 		ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
 					     LOWPAN_IPHC_DAM_BIT);
 	}

 	if (iphc0 & LOWPAN_IPHC_NH_C) {
 		h_enc = skb_network_header(skb)[ret];
 		ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
 	}

 	if (dgram_offset)
 		*dgram_offset = uncomp_header;

 	return skb->len + uncomp_header - ret;
 }

 void lowpan_netdev_setup(struct net_device *dev, enum lowpan_lltypes lltype);

 int
 lowpan_header_decompress(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);
 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__

	#include <net/ipv6.h>
	#include <net/net_namespace.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]))

	/*
	* 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))

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

	/* 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

	/*
	* 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 */
	#define LOWPAN_NHC_UDP_CS_C 0x04 /* checksum elided */

	#define LOWPAN_PRIV_SIZE(llpriv_size) \
	(sizeof(struct lowpan_priv) + llpriv_size)

	enum lowpan_lltypes {
	LOWPAN_LLTYPE_BTLE,
	LOWPAN_LLTYPE_IEEE802154,
	};

	struct lowpan_priv {
	enum lowpan_lltypes lltype;

	/* must be last */
	u8 priv[0] __aligned(sizeof(void *));
	};

	static inline
	struct lowpan_priv lowpan_priv(const struct net_device dev)
	{
	return netdev_priv(dev);
	}

	#ifdef DEBUG
	/* print data in line */
	static inline void raw_dump_inline(const char caller, char msg,
	unsigned char *buf, int len)
	{
	if (msg)
	pr_debug("%s():%s: ", caller, msg);

	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
	}

	/* print data in a table format:
	*
	* addr: xx xx xx xx xx xx
	* addr: xx xx xx xx xx xx
	* ...
	*/
	static inline void raw_dump_table(const char caller, char msg,
	unsigned char *buf, int len)
	{
	if (msg)
	pr_debug("%s():%s:\n", caller, msg);

	print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
	}
	#else
	static inline void raw_dump_table(const char caller, char msg,
	unsigned char *buf, int len) { }
	static inline void raw_dump_inline(const char caller, char msg,
	unsigned char *buf, int len) { }
	#endif

	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 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;
	}

	static inline void lowpan_push_hc_data(u8 *hc_ptr, const void data,
	const size_t len)
	{
	memcpy(*hc_ptr, data, len);
	*hc_ptr += len;
	}

	static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
	{
	static const u8 addr_sizes[] = {
	[LOWPAN_IPHC_ADDR_00] = 16,
	[LOWPAN_IPHC_ADDR_01] = 8,
	[LOWPAN_IPHC_ADDR_02] = 2,
	[LOWPAN_IPHC_ADDR_03] = 0,
	};
	return addr_sizes[addr_mode];
	}

	static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
	{
	u8 ret = 1;

	if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
	*uncomp_header += sizeof(struct udphdr);

	switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
	case LOWPAN_NHC_UDP_CS_P_00:
	ret += 4;
	break;
	case LOWPAN_NHC_UDP_CS_P_01:
	case LOWPAN_NHC_UDP_CS_P_10:
	ret += 3;
	break;
	case LOWPAN_NHC_UDP_CS_P_11:
	ret++;
	break;
	default:
	break;
	}

	if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
	ret += 2;
	}

	return ret;
	}

	/**
	* lowpan_uncompress_size - returns skb->len size with uncompressed header
	* @skb: sk_buff with 6lowpan header inside
	* @datagram_offset: optional to get the datagram_offset value
	*
	* Returns the skb->len with uncompressed header
	*/
	static inline u16
	lowpan_uncompress_size(const struct sk_buff skb, u16 dgram_offset)
	{
	u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
	u8 iphc0, iphc1, h_enc;

	iphc0 = skb_network_header(skb)[0];
	iphc1 = skb_network_header(skb)[1];

	switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
	case 0:
	ret += 4;
	break;
	case 1:
	ret += 3;
	break;
	case 2:
	ret++;
	break;
	default:
	break;
	}

	if (!(iphc0 & LOWPAN_IPHC_NH_C))
	ret++;

	if (!(iphc0 & 0x03))
	ret++;

	ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
	LOWPAN_IPHC_SAM_BIT);

	if (iphc1 & LOWPAN_IPHC_M) {
	switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
	LOWPAN_IPHC_DAM_BIT) {
	case LOWPAN_IPHC_DAM_00:
	ret += 16;
	break;
	case LOWPAN_IPHC_DAM_01:
	ret += 6;
	break;
	case LOWPAN_IPHC_DAM_10:
	ret += 4;
	break;
	case LOWPAN_IPHC_DAM_11:
	ret++;
	break;
	default:
	break;
	}
	} else {
	ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
	LOWPAN_IPHC_DAM_BIT);
	}

	if (iphc0 & LOWPAN_IPHC_NH_C) {
	h_enc = skb_network_header(skb)[ret];
	ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
	}

	if (dgram_offset)
	*dgram_offset = uncomp_header;

	return skb->len + uncomp_header - ret;
	}

	void lowpan_netdev_setup(struct net_device *dev, enum lowpan_lltypes lltype);

	int
	lowpan_header_decompress(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);
	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__ */