Initial import

12 files changed, 1408 insertions, 0 deletions

diff --git a/net/6lowpan/Kconfig b/net/6lowpan/Kconfig
new file mode 100644
index 000000000..7fa0f382e
--- /dev/null
+++ b/net/6lowpan/Kconfig
@@ -0,0 +1,61 @@
+menuconfig 6LOWPAN
+	tristate "6LoWPAN Support"
+	depends on IPV6
+	---help---
+	  This enables IPv6 over Low power Wireless Personal Area Network -
+	  "6LoWPAN" which is supported by IEEE 802.15.4 or Bluetooth stacks.
+
+menuconfig 6LOWPAN_NHC
+	tristate "Next Header Compression Support"
+	depends on 6LOWPAN
+	default y
+	---help---
+	  Support for next header compression.
+
+if 6LOWPAN_NHC
+
+config 6LOWPAN_NHC_DEST
+	tristate "Destination Options Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Destination Options Header compression according to
+	  RFC6282.
+
+config 6LOWPAN_NHC_FRAGMENT
+	tristate "Fragment Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Fragment Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_HOP
+	tristate "Hop-by-Hop Options Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Hop-by-Hop Options Header compression according to
+	  RFC6282.
+
+config 6LOWPAN_NHC_IPV6
+	tristate "IPv6 Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_MOBILITY
+	tristate "Mobility Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Mobility Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_ROUTING
+	tristate "Routing Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 Routing Header compression according to RFC6282.
+
+config 6LOWPAN_NHC_UDP
+	tristate "UDP Header Support"
+	default y
+	---help---
+	  6LoWPAN IPv6 UDP Header compression according to RFC6282.
+
+endif
diff --git a/net/6lowpan/Makefile b/net/6lowpan/Makefile
new file mode 100644
index 000000000..eb8baa72a
--- /dev/null
+++ b/net/6lowpan/Makefile
@@ -0,0 +1,12 @@
+obj-$(CONFIG_6LOWPAN) += 6lowpan.o
+
+6lowpan-y := iphc.o nhc.o
+
+#rfc6282 nhcs
+obj-$(CONFIG_6LOWPAN_NHC_DEST) += nhc_dest.o
+obj-$(CONFIG_6LOWPAN_NHC_FRAGMENT) += nhc_fragment.o
+obj-$(CONFIG_6LOWPAN_NHC_HOP) += nhc_hop.o
+obj-$(CONFIG_6LOWPAN_NHC_IPV6) += nhc_ipv6.o
+obj-$(CONFIG_6LOWPAN_NHC_MOBILITY) += nhc_mobility.o
+obj-$(CONFIG_6LOWPAN_NHC_ROUTING) += nhc_routing.o
+obj-$(CONFIG_6LOWPAN_NHC_UDP) += nhc_udp.o
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
new file mode 100644
index 000000000..94a375c04
--- /dev/null
+++ b/net/6lowpan/iphc.c
@@ -0,0 +1,628 @@
+/*
+ * 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/bitops.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <net/6lowpan.h>
+#include <net/ipv6.h>
+#include <net/af_ieee802154.h>
+
+#include "nhc.h"
+
+/* Uncompress address function for source and
+ * destination address(non-multicast).
+ *
+ * address_mode is sam value or dam value.
+ */
+static int uncompress_addr(struct sk_buff *skb,
+			   struct in6_addr *ipaddr, const u8 address_mode,
+			   const u8 *lladdr, const u8 addr_type,
+			   const u8 addr_len)
+{
+	bool fail;
+
+	switch (address_mode) {
+	case LOWPAN_IPHC_ADDR_00:
+		/* for global link addresses */
+		fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
+		break;
+	case LOWPAN_IPHC_ADDR_01:
+		/* fe:80::XXXX:XXXX:XXXX:XXXX */
+		ipaddr->s6_addr[0] = 0xFE;
+		ipaddr->s6_addr[1] = 0x80;
+		fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
+		break;
+	case LOWPAN_IPHC_ADDR_02:
+		/* fe:80::ff:fe00:XXXX */
+		ipaddr->s6_addr[0] = 0xFE;
+		ipaddr->s6_addr[1] = 0x80;
+		ipaddr->s6_addr[11] = 0xFF;
+		ipaddr->s6_addr[12] = 0xFE;
+		fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
+		break;
+	case LOWPAN_IPHC_ADDR_03:
+		fail = false;
+		switch (addr_type) {
+		case IEEE802154_ADDR_LONG:
+			/* fe:80::XXXX:XXXX:XXXX:XXXX
+			 *        \_________________/
+			 *              hwaddr
+			 */
+			ipaddr->s6_addr[0] = 0xFE;
+			ipaddr->s6_addr[1] = 0x80;
+			memcpy(&ipaddr->s6_addr[8], lladdr, addr_len);
+			/* second bit-flip (Universe/Local)
+			 * is done according RFC2464
+			 */
+			ipaddr->s6_addr[8] ^= 0x02;
+			break;
+		case IEEE802154_ADDR_SHORT:
+			/* fe:80::ff:fe00:XXXX
+			 *		  \__/
+			 *	       short_addr
+			 *
+			 * Universe/Local bit is zero.
+			 */
+			ipaddr->s6_addr[0] = 0xFE;
+			ipaddr->s6_addr[1] = 0x80;
+			ipaddr->s6_addr[11] = 0xFF;
+			ipaddr->s6_addr[12] = 0xFE;
+			ipaddr->s6_addr16[7] = htons(*((u16 *)lladdr));
+			break;
+		default:
+			pr_debug("Invalid addr_type set\n");
+			return -EINVAL;
+		}
+		break;
+	default:
+		pr_debug("Invalid address mode value: 0x%x\n", address_mode);
+		return -EINVAL;
+	}
+
+	if (fail) {
+		pr_debug("Failed to fetch skb data\n");
+		return -EIO;
+	}
+
+	raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
+			ipaddr->s6_addr, 16);
+
+	return 0;
+}
+
+/* Uncompress address function for source context
+ * based address(non-multicast).
+ */
+static int uncompress_context_based_src_addr(struct sk_buff *skb,
+					     struct in6_addr *ipaddr,
+					     const u8 sam)
+{
+	switch (sam) {
+	case LOWPAN_IPHC_ADDR_00:
+		/* unspec address ::
+		 * Do nothing, address is already ::
+		 */
+		break;
+	case LOWPAN_IPHC_ADDR_01:
+		/* TODO */
+	case LOWPAN_IPHC_ADDR_02:
+		/* TODO */
+	case LOWPAN_IPHC_ADDR_03:
+		/* TODO */
+		netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
+		return -EINVAL;
+	default:
+		pr_debug("Invalid sam value: 0x%x\n", sam);
+		return -EINVAL;
+	}
+
+	raw_dump_inline(NULL,
+			"Reconstructed context based ipv6 src addr is",
+			ipaddr->s6_addr, 16);
+
+	return 0;
+}
+
+/* Uncompress function for multicast destination address,
+ * when M bit is set.
+ */
+static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
+					     struct in6_addr *ipaddr,
+					     const u8 dam)
+{
+	bool fail;
+
+	switch (dam) {
+	case LOWPAN_IPHC_DAM_00:
+		/* 00:  128 bits.  The full address
+		 * is carried in-line.
+		 */
+		fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
+		break;
+	case LOWPAN_IPHC_DAM_01:
+		/* 01:  48 bits.  The address takes
+		 * the form ffXX::00XX:XXXX:XXXX.
+		 */
+		ipaddr->s6_addr[0] = 0xFF;
+		fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
+		fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
+		break;
+	case LOWPAN_IPHC_DAM_10:
+		/* 10:  32 bits.  The address takes
+		 * the form ffXX::00XX:XXXX.
+		 */
+		ipaddr->s6_addr[0] = 0xFF;
+		fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
+		fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
+		break;
+	case LOWPAN_IPHC_DAM_11:
+		/* 11:  8 bits.  The address takes
+		 * the form ff02::00XX.
+		 */
+		ipaddr->s6_addr[0] = 0xFF;
+		ipaddr->s6_addr[1] = 0x02;
+		fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
+		break;
+	default:
+		pr_debug("DAM value has a wrong value: 0x%x\n", dam);
+		return -EINVAL;
+	}
+
+	if (fail) {
+		pr_debug("Failed to fetch skb data\n");
+		return -EIO;
+	}
+
+	raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
+			ipaddr->s6_addr, 16);
+
+	return 0;
+}
+
+/* TTL uncompression values */
+static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
+
+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)
+{
+	struct ipv6hdr hdr = {};
+	u8 tmp, num_context = 0;
+	int err;
+
+	raw_dump_table(__func__, "raw skb data dump uncompressed",
+		       skb->data, skb->len);
+
+	/* another if the CID flag is set */
+	if (iphc1 & LOWPAN_IPHC_CID) {
+		pr_debug("CID flag is set, increase header with one\n");
+		if (lowpan_fetch_skb(skb, &num_context, sizeof(num_context)))
+			return -EINVAL;
+	}
+
+	hdr.version = 6;
+
+	/* Traffic Class and Flow Label */
+	switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
+	/* Traffic Class and FLow Label carried in-line
+	 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
+	 */
+	case 0: /* 00b */
+		if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
+			return -EINVAL;
+
+		memcpy(&hdr.flow_lbl, &skb->data[0], 3);
+		skb_pull(skb, 3);
+		hdr.priority = ((tmp >> 2) & 0x0f);
+		hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
+					(hdr.flow_lbl[0] & 0x0f);
+		break;
+	/* Traffic class carried in-line
+	 * ECN + DSCP (1 byte), Flow Label is elided
+	 */
+	case 2: /* 10b */
+		if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
+			return -EINVAL;
+
+		hdr.priority = ((tmp >> 2) & 0x0f);
+		hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
+		break;
+	/* Flow Label carried in-line
+	 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
+	 */
+	case 1: /* 01b */
+		if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
+			return -EINVAL;
+
+		hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
+		memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
+		skb_pull(skb, 2);
+		break;
+	/* Traffic Class and Flow Label are elided */
+	case 3: /* 11b */
+		break;
+	default:
+		break;
+	}
+
+	/* Next Header */
+	if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
+		/* Next header is carried inline */
+		if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
+			return -EINVAL;
+
+		pr_debug("NH flag is set, next header carried inline: %02x\n",
+			 hdr.nexthdr);
+	}
+
+	/* Hop Limit */
+	if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) {
+		hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
+	} else {
+		if (lowpan_fetch_skb(skb, &hdr.hop_limit,
+				     sizeof(hdr.hop_limit)))
+			return -EINVAL;
+	}
+
+	/* Extract SAM to the tmp variable */
+	tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
+
+	if (iphc1 & LOWPAN_IPHC_SAC) {
+		/* Source address context based uncompression */
+		pr_debug("SAC bit is set. Handle context based source address.\n");
+		err = uncompress_context_based_src_addr(skb, &hdr.saddr, tmp);
+	} else {
+		/* Source address uncompression */
+		pr_debug("source address stateless compression\n");
+		err = uncompress_addr(skb, &hdr.saddr, tmp, saddr,
+				      saddr_type, saddr_len);
+	}
+
+	/* Check on error of previous branch */
+	if (err)
+		return -EINVAL;
+
+	/* Extract DAM to the tmp variable */
+	tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
+
+	/* check for Multicast Compression */
+	if (iphc1 & LOWPAN_IPHC_M) {
+		if (iphc1 & LOWPAN_IPHC_DAC) {
+			pr_debug("dest: context-based mcast compression\n");
+			/* TODO: implement this */
+		} else {
+			err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr,
+								tmp);
+
+			if (err)
+				return -EINVAL;
+		}
+	} else {
+		err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
+				      daddr_type, daddr_len);
+		pr_debug("dest: stateless compression mode %d dest %pI6c\n",
+			 tmp, &hdr.daddr);
+		if (err)
+			return -EINVAL;
+	}
+
+	/* Next header data uncompression */
+	if (iphc0 & LOWPAN_IPHC_NH_C) {
+		err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
+		if (err < 0)
+			return err;
+	} else {
+		err = skb_cow(skb, sizeof(hdr));
+		if (unlikely(err))
+			return err;
+	}
+
+	hdr.payload_len = htons(skb->len);
+
+	pr_debug("skb headroom size = %d, data length = %d\n",
+		 skb_headroom(skb), skb->len);
+
+	pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n\t"
+		 "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest    = %pI6c\n",
+		hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
+		hdr.hop_limit, &hdr.daddr);
+
+	skb_push(skb, sizeof(hdr));
+	skb_reset_network_header(skb);
+	skb_copy_to_linear_data(skb, &hdr, sizeof(hdr));
+
+	raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lowpan_header_decompress);
+
+static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift,
+				  const struct in6_addr *ipaddr,
+				  const unsigned char *lladdr)
+{
+	u8 val = 0;
+
+	if (is_addr_mac_addr_based(ipaddr, lladdr)) {
+		val = 3; /* 0-bits */
+		pr_debug("address compression 0 bits\n");
+	} else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
+		/* compress IID to 16 bits xxxx::XXXX */
+		lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
+		val = 2; /* 16-bits */
+		raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
+				*hc_ptr - 2, 2);
+	} else {
+		/* do not compress IID => xxxx::IID */
+		lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
+		val = 1; /* 64-bits */
+		raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
+				*hc_ptr - 8, 8);
+	}
+
+	return rol8(val, shift);
+}
+
+int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
+			   unsigned short type, const void *_daddr,
+			   const void *_saddr, unsigned int len)
+{
+	u8 tmp, iphc0, iphc1, *hc_ptr;
+	struct ipv6hdr *hdr;
+	u8 head[100] = {};
+	int ret, addr_type;
+
+	if (type != ETH_P_IPV6)
+		return -EINVAL;
+
+	hdr = ipv6_hdr(skb);
+	hc_ptr = head + 2;
+
+	pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength  = %d\n"
+		 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest    = %pI6c\n",
+		 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
+		 hdr->hop_limit, &hdr->daddr);
+
+	raw_dump_table(__func__, "raw skb network header dump",
+		       skb_network_header(skb), sizeof(struct ipv6hdr));
+
+	/* As we copy some bit-length fields, in the IPHC encoding bytes,
+	 * we sometimes use |=
+	 * If the field is 0, and the current bit value in memory is 1,
+	 * this does not work. We therefore reset the IPHC encoding here
+	 */
+	iphc0 = LOWPAN_DISPATCH_IPHC;
+	iphc1 = 0;
+
+	/* TODO: context lookup */
+
+	raw_dump_inline(__func__, "saddr",
+			(unsigned char *)_saddr, IEEE802154_ADDR_LEN);
+	raw_dump_inline(__func__, "daddr",
+			(unsigned char *)_daddr, IEEE802154_ADDR_LEN);
+
+	raw_dump_table(__func__, "sending raw skb network uncompressed packet",
+		       skb->data, skb->len);
+
+	/* Traffic class, flow label
+	 * If flow label is 0, compress it. If traffic class is 0, compress it
+	 * We have to process both in the same time as the offset of traffic
+	 * class depends on the presence of version and flow label
+	 */
+
+	/* hc format of TC is ECN | DSCP , original one is DSCP | ECN */
+	tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
+	tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
+
+	if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
+	    (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
+		/* flow label can be compressed */
+		iphc0 |= LOWPAN_IPHC_FL_C;
+		if ((hdr->priority == 0) &&
+		    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
+			/* compress (elide) all */
+			iphc0 |= LOWPAN_IPHC_TC_C;
+		} else {
+			/* compress only the flow label */
+			*hc_ptr = tmp;
+			hc_ptr += 1;
+		}
+	} else {
+		/* Flow label cannot be compressed */
+		if ((hdr->priority == 0) &&
+		    ((hdr->flow_lbl[0] & 0xF0) == 0)) {
+			/* compress only traffic class */
+			iphc0 |= LOWPAN_IPHC_TC_C;
+			*hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
+			memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2);
+			hc_ptr += 3;
+		} else {
+			/* compress nothing */
+			memcpy(hc_ptr, hdr, 4);
+			/* replace the top byte with new ECN | DSCP format */
+			*hc_ptr = tmp;
+			hc_ptr += 4;
+		}
+	}
+
+	/* NOTE: payload length is always compressed */
+
+	/* Check if we provide the nhc format for nexthdr and compression
+	 * functionality. If not nexthdr is handled inline and not compressed.
+	 */
+	ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr, &iphc0);
+	if (ret < 0)
+		return ret;
+
+	/* Hop limit
+	 * if 1:   compress, encoding is 01
+	 * if 64:  compress, encoding is 10
+	 * if 255: compress, encoding is 11
+	 * else do not compress
+	 */
+	switch (hdr->hop_limit) {
+	case 1:
+		iphc0 |= LOWPAN_IPHC_TTL_1;
+		break;
+	case 64:
+		iphc0 |= LOWPAN_IPHC_TTL_64;
+		break;
+	case 255:
+		iphc0 |= LOWPAN_IPHC_TTL_255;
+		break;
+	default:
+		lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
+				    sizeof(hdr->hop_limit));
+	}
+
+	addr_type = ipv6_addr_type(&hdr->saddr);
+	/* source address compression */
+	if (addr_type == IPV6_ADDR_ANY) {
+		pr_debug("source address is unspecified, setting SAC\n");
+		iphc1 |= LOWPAN_IPHC_SAC;
+	} else {
+		if (addr_type & IPV6_ADDR_LINKLOCAL) {
+			iphc1 |= lowpan_compress_addr_64(&hc_ptr,
+							 LOWPAN_IPHC_SAM_BIT,
+							 &hdr->saddr, _saddr);
+			pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n",
+				 &hdr->saddr, iphc1);
+		} else {
+			pr_debug("send the full source address\n");
+			lowpan_push_hc_data(&hc_ptr, hdr->saddr.s6_addr, 16);
+		}
+	}
+
+	addr_type = ipv6_addr_type(&hdr->daddr);
+	/* destination address compression */
+	if (addr_type & IPV6_ADDR_MULTICAST) {
+		pr_debug("destination address is multicast: ");
+		iphc1 |= LOWPAN_IPHC_M;
+		if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
+			pr_debug("compressed to 1 octet\n");
+			iphc1 |= LOWPAN_IPHC_DAM_11;
+			/* use last byte */
+			lowpan_push_hc_data(&hc_ptr,
+					    &hdr->daddr.s6_addr[15], 1);
+		} else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
+			pr_debug("compressed to 4 octets\n");
+			iphc1 |= LOWPAN_IPHC_DAM_10;
+			/* second byte + the last three */
+			lowpan_push_hc_data(&hc_ptr,
+					    &hdr->daddr.s6_addr[1], 1);
+			lowpan_push_hc_data(&hc_ptr,
+					    &hdr->daddr.s6_addr[13], 3);
+		} else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
+			pr_debug("compressed to 6 octets\n");
+			iphc1 |= LOWPAN_IPHC_DAM_01;
+			/* second byte + the last five */
+			lowpan_push_hc_data(&hc_ptr,
+					    &hdr->daddr.s6_addr[1], 1);
+			lowpan_push_hc_data(&hc_ptr,
+					    &hdr->daddr.s6_addr[11], 5);
+		} else {
+			pr_debug("using full address\n");
+			iphc1 |= LOWPAN_IPHC_DAM_00;
+			lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
+		}
+	} else {
+		if (addr_type & IPV6_ADDR_LINKLOCAL) {
+			/* TODO: context lookup */
+			iphc1 |= lowpan_compress_addr_64(&hc_ptr,
+				LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
+			pr_debug("dest address unicast link-local %pI6c "
+				 "iphc1 0x%02x\n", &hdr->daddr, iphc1);
+		} else {
+			pr_debug("dest address unicast %pI6c\n", &hdr->daddr);
+			lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
+		}
+	}
+
+	/* next header compression */
+	if (iphc0 & LOWPAN_IPHC_NH_C) {
+		ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr);
+		if (ret < 0)
+			return ret;
+	}
+
+	head[0] = iphc0;
+	head[1] = iphc1;
+
+	skb_pull(skb, sizeof(struct ipv6hdr));
+	skb_reset_transport_header(skb);
+	memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head);
+	skb_reset_network_header(skb);
+
+	pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len);
+
+	raw_dump_table(__func__, "raw skb data dump compressed",
+		       skb->data, skb->len);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lowpan_header_compress);
+
+static int __init lowpan_module_init(void)
+{
+	request_module_nowait("nhc_dest");
+	request_module_nowait("nhc_fragment");
+	request_module_nowait("nhc_hop");
+	request_module_nowait("nhc_ipv6");
+	request_module_nowait("nhc_mobility");
+	request_module_nowait("nhc_routing");
+	request_module_nowait("nhc_udp");
+
+	return 0;
+}
+module_init(lowpan_module_init);
+
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc.c b/net/6lowpan/nhc.c
new file mode 100644
index 000000000..fd20fc51a
--- /dev/null
+++ b/net/6lowpan/nhc.c
@@ -0,0 +1,241 @@
+/*
+ *	6LoWPAN next header compression
+ *
+ *
+ *	Authors:
+ *	Alexander Aring		<aar@pengutronix.de>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/netdevice.h>
+
+#include <net/ipv6.h>
+
+#include "nhc.h"
+
+static struct rb_root rb_root = RB_ROOT;
+static struct lowpan_nhc *lowpan_nexthdr_nhcs[NEXTHDR_MAX];
+static DEFINE_SPINLOCK(lowpan_nhc_lock);
+
+static int lowpan_nhc_insert(struct lowpan_nhc *nhc)
+{
+	struct rb_node **new = &rb_root.rb_node, *parent = NULL;
+
+	/* Figure out where to put new node */
+	while (*new) {
+		struct lowpan_nhc *this = container_of(*new, struct lowpan_nhc,
+						       node);
+		int result, len_dif, len;
+
+		len_dif = nhc->idlen - this->idlen;
+
+		if (nhc->idlen < this->idlen)
+			len = nhc->idlen;
+		else
+			len = this->idlen;
+
+		result = memcmp(nhc->id, this->id, len);
+		if (!result)
+			result = len_dif;
+
+		parent = *new;
+		if (result < 0)
+			new = &((*new)->rb_left);
+		else if (result > 0)
+			new = &((*new)->rb_right);
+		else
+			return -EEXIST;
+	}
+
+	/* Add new node and rebalance tree. */
+	rb_link_node(&nhc->node, parent, new);
+	rb_insert_color(&nhc->node, &rb_root);
+
+	return 0;
+}
+
+static void lowpan_nhc_remove(struct lowpan_nhc *nhc)
+{
+	rb_erase(&nhc->node, &rb_root);
+}
+
+static struct lowpan_nhc *lowpan_nhc_by_nhcid(const struct sk_buff *skb)
+{
+	struct rb_node *node = rb_root.rb_node;
+	const u8 *nhcid_skb_ptr = skb->data;
+
+	while (node) {
+		struct lowpan_nhc *nhc = container_of(node, struct lowpan_nhc,
+						      node);
+		u8 nhcid_skb_ptr_masked[LOWPAN_NHC_MAX_ID_LEN];
+		int result, i;
+
+		if (nhcid_skb_ptr + nhc->idlen > skb->data + skb->len)
+			return NULL;
+
+		/* copy and mask afterwards the nhid value from skb */
+		memcpy(nhcid_skb_ptr_masked, nhcid_skb_ptr, nhc->idlen);
+		for (i = 0; i < nhc->idlen; i++)
+			nhcid_skb_ptr_masked[i] &= nhc->idmask[i];
+
+		result = memcmp(nhcid_skb_ptr_masked, nhc->id, nhc->idlen);
+		if (result < 0)
+			node = node->rb_left;
+		else if (result > 0)
+			node = node->rb_right;
+		else
+			return nhc;
+	}
+
+	return NULL;
+}
+
+int lowpan_nhc_check_compression(struct sk_buff *skb,
+				 const struct ipv6hdr *hdr, u8 **hc_ptr,
+				 u8 *iphc0)
+{
+	struct lowpan_nhc *nhc;
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	nhc = lowpan_nexthdr_nhcs[hdr->nexthdr];
+	if (nhc && nhc->compress)
+		*iphc0 |= LOWPAN_IPHC_NH_C;
+	else
+		lowpan_push_hc_data(hc_ptr, &hdr->nexthdr,
+				    sizeof(hdr->nexthdr));
+
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	return 0;
+}
+
+int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr,
+			      u8 **hc_ptr)
+{
+	int ret;
+	struct lowpan_nhc *nhc;
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	nhc = lowpan_nexthdr_nhcs[hdr->nexthdr];
+	/* check if the nhc module was removed in unlocked part.
+	 * TODO: this is a workaround we should prevent unloading
+	 * of nhc modules while unlocked part, this will always drop
+	 * the lowpan packet but it's very unlikely.
+	 *
+	 * Solution isn't easy because we need to decide at
+	 * lowpan_nhc_check_compression if we do a compression or not.
+	 * Because the inline data which is added to skb, we can't move this
+	 * handling.
+	 */
+	if (unlikely(!nhc || !nhc->compress)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* In the case of RAW sockets the transport header is not set by
+	 * the ip6 stack so we must set it ourselves
+	 */
+	if (skb->transport_header == skb->network_header)
+		skb_set_transport_header(skb, sizeof(struct ipv6hdr));
+
+	ret = nhc->compress(skb, hc_ptr);
+	if (ret < 0)
+		goto out;
+
+	/* skip the transport header */
+	skb_pull(skb, nhc->nexthdrlen);
+
+out:
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	return ret;
+}
+
+int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev,
+				struct ipv6hdr *hdr)
+{
+	struct lowpan_nhc *nhc;
+	int ret;
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	nhc = lowpan_nhc_by_nhcid(skb);
+	if (nhc) {
+		if (nhc->uncompress) {
+			ret = nhc->uncompress(skb, sizeof(struct ipv6hdr) +
+					      nhc->nexthdrlen);
+			if (ret < 0) {
+				spin_unlock_bh(&lowpan_nhc_lock);
+				return ret;
+			}
+		} else {
+			spin_unlock_bh(&lowpan_nhc_lock);
+			netdev_warn(dev, "received nhc id for %s which is not implemented.\n",
+				    nhc->name);
+			return -ENOTSUPP;
+		}
+	} else {
+		spin_unlock_bh(&lowpan_nhc_lock);
+		netdev_warn(dev, "received unknown nhc id which was not found.\n");
+		return -ENOENT;
+	}
+
+	hdr->nexthdr = nhc->nexthdr;
+	skb_reset_transport_header(skb);
+	raw_dump_table(__func__, "raw transport header dump",
+		       skb_transport_header(skb), nhc->nexthdrlen);
+
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	return 0;
+}
+
+int lowpan_nhc_add(struct lowpan_nhc *nhc)
+{
+	int ret;
+
+	if (!nhc->idlen || !nhc->idsetup)
+		return -EINVAL;
+
+	WARN_ONCE(nhc->idlen > LOWPAN_NHC_MAX_ID_LEN,
+		  "LOWPAN_NHC_MAX_ID_LEN should be updated to %zd.\n",
+		  nhc->idlen);
+
+	nhc->idsetup(nhc);
+
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	if (lowpan_nexthdr_nhcs[nhc->nexthdr]) {
+		ret = -EEXIST;
+		goto out;
+	}
+
+	ret = lowpan_nhc_insert(nhc);
+	if (ret < 0)
+		goto out;
+
+	lowpan_nexthdr_nhcs[nhc->nexthdr] = nhc;
+out:
+	spin_unlock_bh(&lowpan_nhc_lock);
+	return ret;
+}
+EXPORT_SYMBOL(lowpan_nhc_add);
+
+void lowpan_nhc_del(struct lowpan_nhc *nhc)
+{
+	spin_lock_bh(&lowpan_nhc_lock);
+
+	lowpan_nhc_remove(nhc);
+	lowpan_nexthdr_nhcs[nhc->nexthdr] = NULL;
+
+	spin_unlock_bh(&lowpan_nhc_lock);
+
+	synchronize_net();
+}
+EXPORT_SYMBOL(lowpan_nhc_del);
diff --git a/net/6lowpan/nhc.h b/net/6lowpan/nhc.h
new file mode 100644
index 000000000..ed44938eb
--- /dev/null
+++ b/net/6lowpan/nhc.h
@@ -0,0 +1,146 @@
+#ifndef __6LOWPAN_NHC_H
+#define __6LOWPAN_NHC_H
+
+#include <linux/skbuff.h>
+#include <linux/rbtree.h>
+#include <linux/module.h>
+
+#include <net/6lowpan.h>
+#include <net/ipv6.h>
+
+#define LOWPAN_NHC_MAX_ID_LEN	1
+
+/**
+ * LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct
+ *
+ * @__nhc: variable name of the lowpan_nhc struct.
+ * @_name: const char * of common header compression name.
+ * @_nexthdr: ipv6 nexthdr field for the header compression.
+ * @_nexthdrlen: ipv6 nexthdr len for the reserved space.
+ * @_idsetup: callback to setup id and mask values.
+ * @_idlen: len for the next header id and mask, should be always the same.
+ * @_uncompress: callback for uncompression call.
+ * @_compress: callback for compression call.
+ */
+#define LOWPAN_NHC(__nhc, _name, _nexthdr,	\
+		   _hdrlen, _idsetup, _idlen,	\
+		   _uncompress, _compress)	\
+static u8 __nhc##_val[_idlen];			\
+static u8 __nhc##_mask[_idlen];			\
+static struct lowpan_nhc __nhc = {		\
+	.name		= _name,		\
+	.nexthdr	= _nexthdr,		\
+	.nexthdrlen	= _hdrlen,		\
+	.id		= __nhc##_val,		\
+	.idmask		= __nhc##_mask,		\
+	.idlen		= _idlen,		\
+	.idsetup	= _idsetup,		\
+	.uncompress	= _uncompress,		\
+	.compress	= _compress,		\
+}
+
+#define module_lowpan_nhc(__nhc)		\
+static int __init __nhc##_init(void)		\
+{						\
+	return lowpan_nhc_add(&(__nhc));	\
+}						\
+module_init(__nhc##_init);			\
+static void __exit __nhc##_exit(void)		\
+{						\
+	lowpan_nhc_del(&(__nhc));		\
+}						\
+module_exit(__nhc##_exit);
+
+/**
+ * struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation
+ *
+ * @node: holder for the rbtree.
+ * @name: name of the specific next header compression
+ * @nexthdr: next header value of the protocol which should be compressed.
+ * @nexthdrlen: ipv6 nexthdr len for the reserved space.
+ * @id: array for nhc id. Note this need to be in network byteorder.
+ * @mask: array for nhc id mask. Note this need to be in network byteorder.
+ * @len: the length of the next header id and mask.
+ * @setup: callback to setup fill the next header id value and mask.
+ * @compress: callback to do the header compression.
+ * @uncompress: callback to do the header uncompression.
+ */
+struct lowpan_nhc {
+	struct rb_node	node;
+	const char	*name;
+	const u8	nexthdr;
+	const size_t	nexthdrlen;
+	u8		*id;
+	u8		*idmask;
+	const size_t	idlen;
+
+	void		(*idsetup)(struct lowpan_nhc *nhc);
+	int		(*uncompress)(struct sk_buff *skb, size_t needed);
+	int		(*compress)(struct sk_buff *skb, u8 **hc_ptr);
+};
+
+/**
+ * lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr.
+ *
+ * @nexthdr: ipv6 nexthdr value.
+ */
+struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr);
+
+/**
+ * lowpan_nhc_check_compression - checks if we support compression format. If
+ *	we support the nhc by nexthdr field, the 6LoWPAN iphc NHC bit will be
+ *	set. If we don't support nexthdr will be added as inline data to the
+ *	6LoWPAN header.
+ *
+ * @skb: skb of 6LoWPAN header to read nhc and replace header.
+ * @hdr: ipv6hdr to check the nexthdr value
+ * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
+ *	    replaced header.
+ * @iphc0: iphc0 pointer to set the 6LoWPAN NHC bit
+ */
+int lowpan_nhc_check_compression(struct sk_buff *skb,
+				 const struct ipv6hdr *hdr, u8 **hc_ptr,
+				 u8 *iphc0);
+
+/**
+ * lowpan_nhc_do_compression - calling compress callback for nhc
+ *
+ * @skb: skb of 6LoWPAN header to read nhc and replace header.
+ * @hdr: ipv6hdr to set the nexthdr value
+ * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
+ *	    replaced header.
+ */
+int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr,
+			      u8 **hc_ptr);
+
+/**
+ * lowpan_nhc_do_uncompression - calling uncompress callback for nhc
+ *
+ * @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions.
+ * @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value.
+ * @dev: netdevice for print logging information.
+ * @hdr: ipv6hdr for setting nexthdr value.
+ */
+int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev,
+				struct ipv6hdr *hdr);
+
+/**
+ * lowpan_nhc_add - register a next header compression to framework
+ *
+ * @nhc: nhc which should be add.
+ */
+int lowpan_nhc_add(struct lowpan_nhc *nhc);
+
+/**
+ * lowpan_nhc_del - delete a next header compression from framework
+ *
+ * @nhc: nhc which should be delete.
+ */
+void lowpan_nhc_del(struct lowpan_nhc *nhc);
+
+/**
+ * lowpan_nhc_init - adding all default nhcs
+ */
+void lowpan_nhc_init(void);
+
+#endif /* __6LOWPAN_NHC_H */
diff --git a/net/6lowpan/nhc_dest.c b/net/6lowpan/nhc_dest.c
new file mode 100644
index 000000000..0b292c964
--- /dev/null
+++ b/net/6lowpan/nhc_dest.c
@@ -0,0 +1,28 @@
+/*
+ *	6LoWPAN IPv6 Destination Options Header compression according to
+ *	RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_DEST_IDLEN	1
+#define LOWPAN_NHC_DEST_ID_0	0xe6
+#define LOWPAN_NHC_DEST_MASK_0	0xfe
+
+static void dest_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_DEST_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_DEST_MASK_0;
+}
+
+LOWPAN_NHC(nhc_dest, "RFC6282 Destination Options", NEXTHDR_DEST, 0,
+	   dest_nhid_setup, LOWPAN_NHC_DEST_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_dest);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Destination Options compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_fragment.c b/net/6lowpan/nhc_fragment.c
new file mode 100644
index 000000000..473dbc58e
--- /dev/null
+++ b/net/6lowpan/nhc_fragment.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Fragment Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_FRAGMENT_IDLEN	1
+#define LOWPAN_NHC_FRAGMENT_ID_0	0xe4
+#define LOWPAN_NHC_FRAGMENT_MASK_0	0xfe
+
+static void fragment_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_FRAGMENT_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_FRAGMENT_MASK_0;
+}
+
+LOWPAN_NHC(nhc_fragment, "RFC6282 Fragment", NEXTHDR_FRAGMENT, 0,
+	   fragment_nhid_setup, LOWPAN_NHC_FRAGMENT_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_fragment);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Fragment compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_hop.c b/net/6lowpan/nhc_hop.c
new file mode 100644
index 000000000..1eb66be16
--- /dev/null
+++ b/net/6lowpan/nhc_hop.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Hop-by-Hop Options Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_HOP_IDLEN	1
+#define LOWPAN_NHC_HOP_ID_0	0xe0
+#define LOWPAN_NHC_HOP_MASK_0	0xfe
+
+static void hop_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_HOP_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_HOP_MASK_0;
+}
+
+LOWPAN_NHC(nhc_hop, "RFC6282 Hop-by-Hop Options", NEXTHDR_HOP, 0,
+	   hop_nhid_setup, LOWPAN_NHC_HOP_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_hop);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Hop-by-Hop Options compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_ipv6.c b/net/6lowpan/nhc_ipv6.c
new file mode 100644
index 000000000..2313d1600
--- /dev/null
+++ b/net/6lowpan/nhc_ipv6.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_IPV6_IDLEN	1
+#define LOWPAN_NHC_IPV6_ID_0	0xee
+#define LOWPAN_NHC_IPV6_MASK_0	0xfe
+
+static void ipv6_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_IPV6_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_IPV6_MASK_0;
+}
+
+LOWPAN_NHC(nhc_ipv6, "RFC6282 IPv6", NEXTHDR_IPV6, 0, ipv6_nhid_setup,
+	   LOWPAN_NHC_IPV6_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_ipv6);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 IPv6 compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_mobility.c b/net/6lowpan/nhc_mobility.c
new file mode 100644
index 000000000..60d3f3886
--- /dev/null
+++ b/net/6lowpan/nhc_mobility.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Mobility Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_MOBILITY_IDLEN	1
+#define LOWPAN_NHC_MOBILITY_ID_0	0xe8
+#define LOWPAN_NHC_MOBILITY_MASK_0	0xfe
+
+static void mobility_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_MOBILITY_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_MOBILITY_MASK_0;
+}
+
+LOWPAN_NHC(nhc_mobility, "RFC6282 Mobility", NEXTHDR_MOBILITY, 0,
+	   mobility_nhid_setup, LOWPAN_NHC_MOBILITY_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_mobility);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Mobility compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_routing.c b/net/6lowpan/nhc_routing.c
new file mode 100644
index 000000000..c393280f1
--- /dev/null
+++ b/net/6lowpan/nhc_routing.c
@@ -0,0 +1,27 @@
+/*
+ *	6LoWPAN IPv6 Routing Header compression according to RFC6282
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_ROUTING_IDLEN	1
+#define LOWPAN_NHC_ROUTING_ID_0		0xe2
+#define LOWPAN_NHC_ROUTING_MASK_0	0xfe
+
+static void routing_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_ROUTING_ID_0;
+	nhc->idmask[0] = LOWPAN_NHC_ROUTING_MASK_0;
+}
+
+LOWPAN_NHC(nhc_routing, "RFC6282 Routing", NEXTHDR_ROUTING, 0,
+	   routing_nhid_setup, LOWPAN_NHC_ROUTING_IDLEN, NULL, NULL);
+
+module_lowpan_nhc(nhc_routing);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Routing compression");
+MODULE_LICENSE("GPL");
diff --git a/net/6lowpan/nhc_udp.c b/net/6lowpan/nhc_udp.c
new file mode 100644
index 000000000..c6bcaeb42
--- /dev/null
+++ b/net/6lowpan/nhc_udp.c
@@ -0,0 +1,157 @@
+/*
+ *	6LoWPAN IPv6 UDP compression according to RFC6282
+ *
+ *
+ *	Authors:
+ *	Alexander Aring	<aar@pengutronix.de>
+ *
+ *	Orignal written by:
+ *	Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ *	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
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include "nhc.h"
+
+#define LOWPAN_NHC_UDP_IDLEN	1
+
+static int udp_uncompress(struct sk_buff *skb, size_t needed)
+{
+	u8 tmp = 0, val = 0;
+	struct udphdr uh;
+	bool fail;
+	int err;
+
+	fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp));
+
+	pr_debug("UDP header uncompression\n");
+	switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
+	case LOWPAN_NHC_UDP_CS_P_00:
+		fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source));
+		fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest));
+		break;
+	case LOWPAN_NHC_UDP_CS_P_01:
+		fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source));
+		fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
+		uh.dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
+		break;
+	case LOWPAN_NHC_UDP_CS_P_10:
+		fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
+		uh.source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
+		fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest));
+		break;
+	case LOWPAN_NHC_UDP_CS_P_11:
+		fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
+		uh.source = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val >> 4));
+		uh.dest = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val & 0x0f));
+		break;
+	default:
+		BUG();
+	}
+
+	pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
+		 ntohs(uh.source), ntohs(uh.dest));
+
+	/* checksum */
+	if (tmp & LOWPAN_NHC_UDP_CS_C) {
+		pr_debug_ratelimited("checksum elided currently not supported\n");
+		fail = true;
+	} else {
+		fail |= lowpan_fetch_skb(skb, &uh.check, sizeof(uh.check));
+	}
+
+	if (fail)
+		return -EINVAL;
+
+	/* UDP length needs to be infered from the lower layers
+	 * here, we obtain the hint from the remaining size of the
+	 * frame
+	 */
+	uh.len = htons(skb->len + sizeof(struct udphdr));
+	pr_debug("uncompressed UDP length: src = %d", ntohs(uh.len));
+
+	/* replace the compressed UDP head by the uncompressed UDP
+	 * header
+	 */
+	err = skb_cow(skb, needed);
+	if (unlikely(err))
+		return err;
+
+	skb_push(skb, sizeof(struct udphdr));
+	skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
+
+	return 0;
+}
+
+static int udp_compress(struct sk_buff *skb, u8 **hc_ptr)
+{
+	const struct udphdr *uh = udp_hdr(skb);
+	u8 tmp;
+
+	if (((ntohs(uh->source) & LOWPAN_NHC_UDP_4BIT_MASK) ==
+	     LOWPAN_NHC_UDP_4BIT_PORT) &&
+	    ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) ==
+	     LOWPAN_NHC_UDP_4BIT_PORT)) {
+		pr_debug("UDP header: both ports compression to 4 bits\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_11;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source and destination port */
+		tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT +
+		      ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4);
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+	} else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) ==
+			LOWPAN_NHC_UDP_8BIT_PORT) {
+		pr_debug("UDP header: remove 8 bits of dest\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_01;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source port */
+		lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
+		/* destination port */
+		tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+	} else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) ==
+			LOWPAN_NHC_UDP_8BIT_PORT) {
+		pr_debug("UDP header: remove 8 bits of source\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_10;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source port */
+		tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* destination port */
+		lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
+	} else {
+		pr_debug("UDP header: can't compress\n");
+		/* compression value */
+		tmp = LOWPAN_NHC_UDP_CS_P_00;
+		lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
+		/* source port */
+		lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
+		/* destination port */
+		lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
+	}
+
+	/* checksum is always inline */
+	lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check));
+
+	return 0;
+}
+
+static void udp_nhid_setup(struct lowpan_nhc *nhc)
+{
+	nhc->id[0] = LOWPAN_NHC_UDP_ID;
+	nhc->idmask[0] = LOWPAN_NHC_UDP_MASK;
+}
+
+LOWPAN_NHC(nhc_udp, "RFC6282 UDP", NEXTHDR_UDP, sizeof(struct udphdr),
+	   udp_nhid_setup, LOWPAN_NHC_UDP_IDLEN, udp_uncompress, udp_compress);
+
+module_lowpan_nhc(nhc_udp);
+MODULE_DESCRIPTION("6LoWPAN next header RFC6282 UDP compression");
+MODULE_LICENSE("GPL");