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![Alexander Aring](/assets/img/avatar_default.png)
This patch moves the mcast compression algorithmn to an own function like all other compression/decompression methods in iphc. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
873 lines
25 KiB
C
873 lines
25 KiB
C
/*
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* Copyright 2011, Siemens AG
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* written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
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*/
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/* Based on patches from Jon Smirl <jonsmirl@gmail.com>
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* Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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/* Jon's code is based on 6lowpan implementation for Contiki which is:
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* Copyright (c) 2008, Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <linux/bitops.h>
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#include <linux/if_arp.h>
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#include <linux/netdevice.h>
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#include <net/6lowpan.h>
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#include <net/ipv6.h>
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/* special link-layer handling */
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#include <net/mac802154.h>
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#include "nhc.h"
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/* Values of fields within the IPHC encoding first byte */
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#define LOWPAN_IPHC_TF_MASK 0x18
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#define LOWPAN_IPHC_TF_00 0x00
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#define LOWPAN_IPHC_TF_01 0x08
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#define LOWPAN_IPHC_TF_10 0x10
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#define LOWPAN_IPHC_TF_11 0x18
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#define LOWPAN_IPHC_NH 0x04
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#define LOWPAN_IPHC_HLIM_MASK 0x03
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#define LOWPAN_IPHC_HLIM_00 0x00
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#define LOWPAN_IPHC_HLIM_01 0x01
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#define LOWPAN_IPHC_HLIM_10 0x02
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#define LOWPAN_IPHC_HLIM_11 0x03
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/* Values of fields within the IPHC encoding second byte */
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#define LOWPAN_IPHC_CID 0x80
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#define LOWPAN_IPHC_SAC 0x40
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#define LOWPAN_IPHC_SAM_MASK 0x30
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#define LOWPAN_IPHC_SAM_00 0x00
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#define LOWPAN_IPHC_SAM_01 0x10
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#define LOWPAN_IPHC_SAM_10 0x20
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#define LOWPAN_IPHC_SAM_11 0x30
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#define LOWPAN_IPHC_M 0x08
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#define LOWPAN_IPHC_DAC 0x04
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#define LOWPAN_IPHC_DAM_MASK 0x03
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#define LOWPAN_IPHC_DAM_00 0x00
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#define LOWPAN_IPHC_DAM_01 0x01
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#define LOWPAN_IPHC_DAM_10 0x02
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#define LOWPAN_IPHC_DAM_11 0x03
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/* ipv6 address based on mac
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* second bit-flip (Universe/Local) is done according RFC2464
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*/
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#define is_addr_mac_addr_based(a, m) \
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((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \
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(((a)->s6_addr[9]) == (m)[1]) && \
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(((a)->s6_addr[10]) == (m)[2]) && \
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(((a)->s6_addr[11]) == (m)[3]) && \
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(((a)->s6_addr[12]) == (m)[4]) && \
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(((a)->s6_addr[13]) == (m)[5]) && \
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(((a)->s6_addr[14]) == (m)[6]) && \
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(((a)->s6_addr[15]) == (m)[7]))
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/* check whether we can compress the IID to 16 bits,
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* it's possible for unicast addresses with first 49 bits are zero only.
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*/
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#define lowpan_is_iid_16_bit_compressable(a) \
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((((a)->s6_addr16[4]) == 0) && \
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(((a)->s6_addr[10]) == 0) && \
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(((a)->s6_addr[11]) == 0xff) && \
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(((a)->s6_addr[12]) == 0xfe) && \
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(((a)->s6_addr[13]) == 0))
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/* check whether the 112-bit gid of the multicast address is mappable to: */
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/* 48 bits, FFXX::00XX:XXXX:XXXX */
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#define lowpan_is_mcast_addr_compressable48(a) \
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((((a)->s6_addr16[1]) == 0) && \
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(((a)->s6_addr16[2]) == 0) && \
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(((a)->s6_addr16[3]) == 0) && \
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(((a)->s6_addr16[4]) == 0) && \
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(((a)->s6_addr[10]) == 0))
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/* 32 bits, FFXX::00XX:XXXX */
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#define lowpan_is_mcast_addr_compressable32(a) \
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((((a)->s6_addr16[1]) == 0) && \
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(((a)->s6_addr16[2]) == 0) && \
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(((a)->s6_addr16[3]) == 0) && \
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(((a)->s6_addr16[4]) == 0) && \
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(((a)->s6_addr16[5]) == 0) && \
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(((a)->s6_addr[12]) == 0))
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/* 8 bits, FF02::00XX */
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#define lowpan_is_mcast_addr_compressable8(a) \
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((((a)->s6_addr[1]) == 2) && \
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(((a)->s6_addr16[1]) == 0) && \
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(((a)->s6_addr16[2]) == 0) && \
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(((a)->s6_addr16[3]) == 0) && \
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(((a)->s6_addr16[4]) == 0) && \
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(((a)->s6_addr16[5]) == 0) && \
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(((a)->s6_addr16[6]) == 0) && \
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(((a)->s6_addr[14]) == 0))
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static inline void iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
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const void *lladdr)
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{
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/* fe:80::XXXX:XXXX:XXXX:XXXX
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* \_________________/
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* hwaddr
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*/
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ipaddr->s6_addr[0] = 0xFE;
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ipaddr->s6_addr[1] = 0x80;
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memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
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/* second bit-flip (Universe/Local)
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* is done according RFC2464
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*/
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ipaddr->s6_addr[8] ^= 0x02;
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}
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static inline void iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr,
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const void *lladdr)
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{
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const struct ieee802154_addr *addr = lladdr;
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u8 eui64[EUI64_ADDR_LEN] = { };
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switch (addr->mode) {
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case IEEE802154_ADDR_LONG:
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ieee802154_le64_to_be64(eui64, &addr->extended_addr);
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iphc_uncompress_eui64_lladdr(ipaddr, eui64);
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break;
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case IEEE802154_ADDR_SHORT:
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/* fe:80::ff:fe00:XXXX
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* \__/
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* short_addr
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*
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* Universe/Local bit is zero.
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*/
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ipaddr->s6_addr[0] = 0xFE;
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ipaddr->s6_addr[1] = 0x80;
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ipaddr->s6_addr[11] = 0xFF;
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ipaddr->s6_addr[12] = 0xFE;
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ieee802154_le16_to_be16(&ipaddr->s6_addr16[7],
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&addr->short_addr);
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break;
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default:
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/* should never handled and filtered by 802154 6lowpan */
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WARN_ON_ONCE(1);
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break;
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}
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}
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/* Uncompress address function for source and
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* destination address(non-multicast).
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*
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* address_mode is the masked value for sam or dam value
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*/
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static int uncompress_addr(struct sk_buff *skb, const struct net_device *dev,
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struct in6_addr *ipaddr, u8 address_mode,
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const void *lladdr)
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{
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bool fail;
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switch (address_mode) {
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/* SAM and DAM are the same here */
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case LOWPAN_IPHC_DAM_00:
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/* for global link addresses */
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fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
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break;
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case LOWPAN_IPHC_SAM_01:
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case LOWPAN_IPHC_DAM_01:
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/* fe:80::XXXX:XXXX:XXXX:XXXX */
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ipaddr->s6_addr[0] = 0xFE;
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ipaddr->s6_addr[1] = 0x80;
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fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
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break;
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case LOWPAN_IPHC_SAM_10:
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case LOWPAN_IPHC_DAM_10:
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/* fe:80::ff:fe00:XXXX */
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ipaddr->s6_addr[0] = 0xFE;
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ipaddr->s6_addr[1] = 0x80;
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ipaddr->s6_addr[11] = 0xFF;
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ipaddr->s6_addr[12] = 0xFE;
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fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
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break;
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case LOWPAN_IPHC_SAM_11:
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case LOWPAN_IPHC_DAM_11:
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fail = false;
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switch (lowpan_priv(dev)->lltype) {
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case LOWPAN_LLTYPE_IEEE802154:
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iphc_uncompress_802154_lladdr(ipaddr, lladdr);
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break;
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default:
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iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
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break;
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}
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break;
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default:
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pr_debug("Invalid address mode value: 0x%x\n", address_mode);
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return -EINVAL;
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}
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if (fail) {
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pr_debug("Failed to fetch skb data\n");
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return -EIO;
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}
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raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
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ipaddr->s6_addr, 16);
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return 0;
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}
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/* Uncompress address function for source context
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* based address(non-multicast).
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*/
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static int uncompress_context_based_src_addr(struct sk_buff *skb,
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struct in6_addr *ipaddr,
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u8 address_mode)
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{
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switch (address_mode) {
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case LOWPAN_IPHC_SAM_00:
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/* unspec address ::
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* Do nothing, address is already ::
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*/
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break;
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case LOWPAN_IPHC_SAM_01:
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/* TODO */
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case LOWPAN_IPHC_SAM_10:
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/* TODO */
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case LOWPAN_IPHC_SAM_11:
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/* TODO */
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netdev_warn(skb->dev, "SAM value 0x%x not supported\n",
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address_mode);
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return -EINVAL;
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default:
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pr_debug("Invalid sam value: 0x%x\n", address_mode);
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return -EINVAL;
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}
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raw_dump_inline(NULL,
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"Reconstructed context based ipv6 src addr is",
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ipaddr->s6_addr, 16);
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return 0;
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}
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/* Uncompress function for multicast destination address,
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* when M bit is set.
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*/
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static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
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struct in6_addr *ipaddr,
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u8 address_mode)
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{
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bool fail;
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switch (address_mode) {
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case LOWPAN_IPHC_DAM_00:
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/* 00: 128 bits. The full address
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* is carried in-line.
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*/
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fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
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break;
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case LOWPAN_IPHC_DAM_01:
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/* 01: 48 bits. The address takes
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* the form ffXX::00XX:XXXX:XXXX.
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*/
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ipaddr->s6_addr[0] = 0xFF;
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fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
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fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
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break;
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case LOWPAN_IPHC_DAM_10:
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/* 10: 32 bits. The address takes
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* the form ffXX::00XX:XXXX.
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*/
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ipaddr->s6_addr[0] = 0xFF;
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fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
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fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
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break;
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case LOWPAN_IPHC_DAM_11:
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/* 11: 8 bits. The address takes
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* the form ff02::00XX.
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*/
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ipaddr->s6_addr[0] = 0xFF;
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ipaddr->s6_addr[1] = 0x02;
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fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
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break;
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default:
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pr_debug("DAM value has a wrong value: 0x%x\n", address_mode);
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return -EINVAL;
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}
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if (fail) {
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pr_debug("Failed to fetch skb data\n");
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return -EIO;
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}
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raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
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ipaddr->s6_addr, 16);
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return 0;
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}
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/* get the ecn values from iphc tf format and set it to ipv6hdr */
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static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf)
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{
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/* get the two higher bits which is ecn */
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u8 ecn = tf[0] & 0xc0;
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/* ECN takes 0x30 in hdr->flow_lbl[0] */
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hdr->flow_lbl[0] |= (ecn >> 2);
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}
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/* get the dscp values from iphc tf format and set it to ipv6hdr */
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static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf)
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{
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/* DSCP is at place after ECN */
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u8 dscp = tf[0] & 0x3f;
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/* The four highest bits need to be set at hdr->priority */
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hdr->priority |= ((dscp & 0x3c) >> 2);
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/* The two lower bits is part of hdr->flow_lbl[0] */
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hdr->flow_lbl[0] |= ((dscp & 0x03) << 6);
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}
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/* get the flow label values from iphc tf format and set it to ipv6hdr */
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static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl)
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{
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/* flow label is always some array started with lower nibble of
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* flow_lbl[0] and followed with two bytes afterwards. Inside inline
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* data the flow_lbl position can be different, which will be handled
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* by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit
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* shifted, the different lbl pointer will handle that.
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*
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* The flow label will started at lower nibble of flow_lbl[0], the
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* higher nibbles are part of DSCP + ECN.
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*/
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hdr->flow_lbl[0] |= lbl[0] & 0x0f;
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memcpy(&hdr->flow_lbl[1], &lbl[1], 2);
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}
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/* lowpan_iphc_tf_decompress - decompress the traffic class.
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* This function will return zero on success, a value lower than zero if
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* failed.
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*/
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static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr,
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u8 val)
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{
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u8 tf[4];
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/* Traffic Class and Flow Label */
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switch (val) {
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case LOWPAN_IPHC_TF_00:
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/* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */
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if (lowpan_fetch_skb(skb, tf, 4))
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return -EINVAL;
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/* 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |ECN| DSCP | rsv | Flow Label |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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lowpan_iphc_tf_set_ecn(hdr, tf);
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lowpan_iphc_tf_set_dscp(hdr, tf);
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lowpan_iphc_tf_set_lbl(hdr, &tf[1]);
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break;
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case LOWPAN_IPHC_TF_01:
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/* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */
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if (lowpan_fetch_skb(skb, tf, 3))
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return -EINVAL;
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/* 1 2
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |ECN|rsv| Flow Label |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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lowpan_iphc_tf_set_ecn(hdr, tf);
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lowpan_iphc_tf_set_lbl(hdr, &tf[0]);
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break;
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case LOWPAN_IPHC_TF_10:
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/* ECN + DSCP (1 byte), Flow Label is elided. */
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if (lowpan_fetch_skb(skb, tf, 1))
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return -EINVAL;
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/* 0 1 2 3 4 5 6 7
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* +-+-+-+-+-+-+-+-+
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* |ECN| DSCP |
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* +-+-+-+-+-+-+-+-+
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*/
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lowpan_iphc_tf_set_ecn(hdr, tf);
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lowpan_iphc_tf_set_dscp(hdr, tf);
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break;
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case LOWPAN_IPHC_TF_11:
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/* Traffic Class and Flow Label are elided */
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break;
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default:
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WARN_ON_ONCE(1);
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return -EINVAL;
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}
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return 0;
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}
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/* TTL uncompression values */
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static const u8 lowpan_ttl_values[] = {
|
|
[LOWPAN_IPHC_HLIM_01] = 1,
|
|
[LOWPAN_IPHC_HLIM_10] = 64,
|
|
[LOWPAN_IPHC_HLIM_11] = 255,
|
|
};
|
|
|
|
int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
|
|
const void *daddr, const void *saddr)
|
|
{
|
|
struct ipv6hdr hdr = {};
|
|
u8 iphc0, iphc1;
|
|
int err;
|
|
|
|
raw_dump_table(__func__, "raw skb data dump uncompressed",
|
|
skb->data, skb->len);
|
|
|
|
if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) ||
|
|
lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1)))
|
|
return -EINVAL;
|
|
|
|
/* another if the CID flag is set */
|
|
if (iphc1 & LOWPAN_IPHC_CID)
|
|
return -ENOTSUPP;
|
|
|
|
hdr.version = 6;
|
|
|
|
err = lowpan_iphc_tf_decompress(skb, &hdr,
|
|
iphc0 & LOWPAN_IPHC_TF_MASK);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
/* Next Header */
|
|
if (!(iphc0 & LOWPAN_IPHC_NH)) {
|
|
/* 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 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) {
|
|
hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK];
|
|
} else {
|
|
if (lowpan_fetch_skb(skb, &hdr.hop_limit,
|
|
sizeof(hdr.hop_limit)))
|
|
return -EINVAL;
|
|
}
|
|
|
|
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,
|
|
iphc1 & LOWPAN_IPHC_SAM_MASK);
|
|
} else {
|
|
/* Source address uncompression */
|
|
pr_debug("source address stateless compression\n");
|
|
err = uncompress_addr(skb, dev, &hdr.saddr,
|
|
iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
|
|
}
|
|
|
|
/* Check on error of previous branch */
|
|
if (err)
|
|
return -EINVAL;
|
|
|
|
/* 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,
|
|
iphc1 & LOWPAN_IPHC_DAM_MASK);
|
|
|
|
if (err)
|
|
return -EINVAL;
|
|
}
|
|
} else {
|
|
err = uncompress_addr(skb, dev, &hdr.daddr,
|
|
iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
|
|
pr_debug("dest: stateless compression mode %d dest %pI6c\n",
|
|
iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr);
|
|
if (err)
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Next header data uncompression */
|
|
if (iphc0 & LOWPAN_IPHC_NH) {
|
|
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;
|
|
}
|
|
|
|
switch (lowpan_priv(dev)->lltype) {
|
|
case LOWPAN_LLTYPE_IEEE802154:
|
|
if (lowpan_802154_cb(skb)->d_size)
|
|
hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size -
|
|
sizeof(struct ipv6hdr));
|
|
else
|
|
hdr.payload_len = htons(skb->len);
|
|
break;
|
|
default:
|
|
hdr.payload_len = htons(skb->len);
|
|
break;
|
|
}
|
|
|
|
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 const u8 lowpan_iphc_dam_to_sam_value[] = {
|
|
[LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00,
|
|
[LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01,
|
|
[LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10,
|
|
[LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11,
|
|
};
|
|
|
|
static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr,
|
|
const unsigned char *lladdr, bool sam)
|
|
{
|
|
u8 dam = LOWPAN_IPHC_DAM_00;
|
|
|
|
if (is_addr_mac_addr_based(ipaddr, lladdr)) {
|
|
dam = LOWPAN_IPHC_DAM_11; /* 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);
|
|
dam = LOWPAN_IPHC_DAM_10; /* 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);
|
|
dam = LOWPAN_IPHC_DAM_01; /* 64-bits */
|
|
raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
|
|
*hc_ptr - 8, 8);
|
|
}
|
|
|
|
if (sam)
|
|
return lowpan_iphc_dam_to_sam_value[dam];
|
|
else
|
|
return dam;
|
|
}
|
|
|
|
/* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */
|
|
static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr)
|
|
{
|
|
u8 dscp, ecn;
|
|
|
|
/* hdr->priority contains the higher bits of dscp, lower are part of
|
|
* flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr.
|
|
*/
|
|
dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6);
|
|
/* ECN is at the two lower bits from first nibble of flow_lbl[0] */
|
|
ecn = (hdr->flow_lbl[0] & 0x30);
|
|
/* for pretty debug output, also shift ecn to get the ecn value */
|
|
pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp);
|
|
/* ECN is at 0x30 now, shift it to have ECN + DCSP */
|
|
return (ecn << 2) | dscp;
|
|
}
|
|
|
|
/* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */
|
|
static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr)
|
|
{
|
|
return ((!(hdr->flow_lbl[0] & 0x0f)) &&
|
|
!hdr->flow_lbl[1] && !hdr->flow_lbl[2]);
|
|
}
|
|
|
|
/* lowpan_iphc_tf_compress - compress the traffic class which is set by
|
|
* ipv6hdr. Return the corresponding format identifier which is used.
|
|
*/
|
|
static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr)
|
|
{
|
|
/* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */
|
|
u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val;
|
|
|
|
/* printout the traffic class in hc format */
|
|
pr_debug("tc 0x%02x\n", tc);
|
|
|
|
if (lowpan_iphc_is_flow_lbl_zero(hdr)) {
|
|
if (!tc) {
|
|
/* 11: Traffic Class and Flow Label are elided. */
|
|
val = LOWPAN_IPHC_TF_11;
|
|
} else {
|
|
/* 10: ECN + DSCP (1 byte), Flow Label is elided.
|
|
*
|
|
* 0 1 2 3 4 5 6 7
|
|
* +-+-+-+-+-+-+-+-+
|
|
* |ECN| DSCP |
|
|
* +-+-+-+-+-+-+-+-+
|
|
*/
|
|
lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc));
|
|
val = LOWPAN_IPHC_TF_10;
|
|
}
|
|
} else {
|
|
/* check if dscp is zero, it's after the first two bit */
|
|
if (!(tc & 0x3f)) {
|
|
/* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
|
|
*
|
|
* 1 2
|
|
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
|
|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
* |ECN|rsv| Flow Label |
|
|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
*/
|
|
memcpy(&tf[0], &hdr->flow_lbl[0], 3);
|
|
/* zero the highest 4-bits, contains DCSP + ECN */
|
|
tf[0] &= ~0xf0;
|
|
/* set ECN */
|
|
tf[0] |= (tc & 0xc0);
|
|
|
|
lowpan_push_hc_data(hc_ptr, tf, 3);
|
|
val = LOWPAN_IPHC_TF_01;
|
|
} else {
|
|
/* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
|
|
*
|
|
* 1 2 3
|
|
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
* |ECN| DSCP | rsv | Flow Label |
|
|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
*/
|
|
memcpy(&tf[0], &tc, sizeof(tc));
|
|
/* highest nibble of flow_lbl[0] is part of DSCP + ECN
|
|
* which will be the 4-bit pad and will be filled with
|
|
* zeros afterwards.
|
|
*/
|
|
memcpy(&tf[1], &hdr->flow_lbl[0], 3);
|
|
/* zero the 4-bit pad, which is reserved */
|
|
tf[1] &= ~0xf0;
|
|
|
|
lowpan_push_hc_data(hc_ptr, tf, 4);
|
|
val = LOWPAN_IPHC_TF_00;
|
|
}
|
|
}
|
|
|
|
return val;
|
|
}
|
|
|
|
static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr,
|
|
const struct in6_addr *ipaddr)
|
|
{
|
|
u8 val;
|
|
|
|
if (lowpan_is_mcast_addr_compressable8(ipaddr)) {
|
|
pr_debug("compressed to 1 octet\n");
|
|
/* use last byte */
|
|
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1);
|
|
val = LOWPAN_IPHC_DAM_11;
|
|
} else if (lowpan_is_mcast_addr_compressable32(ipaddr)) {
|
|
pr_debug("compressed to 4 octets\n");
|
|
/* second byte + the last three */
|
|
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
|
|
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3);
|
|
val = LOWPAN_IPHC_DAM_10;
|
|
} else if (lowpan_is_mcast_addr_compressable48(ipaddr)) {
|
|
pr_debug("compressed to 6 octets\n");
|
|
/* second byte + the last five */
|
|
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
|
|
lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5);
|
|
val = LOWPAN_IPHC_DAM_01;
|
|
} else {
|
|
pr_debug("using full address\n");
|
|
lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16);
|
|
val = LOWPAN_IPHC_DAM_00;
|
|
}
|
|
|
|
return val;
|
|
}
|
|
|
|
int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
|
|
const void *daddr, const void *saddr)
|
|
{
|
|
u8 iphc0, iphc1, *hc_ptr;
|
|
struct ipv6hdr *hdr;
|
|
u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {};
|
|
int ret, addr_type;
|
|
|
|
if (skb->protocol != htons(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", saddr, EUI64_ADDR_LEN);
|
|
raw_dump_inline(__func__, "daddr", daddr, EUI64_ADDR_LEN);
|
|
|
|
raw_dump_table(__func__, "sending raw skb network uncompressed packet",
|
|
skb->data, skb->len);
|
|
|
|
/* Traffic Class, Flow Label compression */
|
|
iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr);
|
|
|
|
/* 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);
|
|
if (ret == -ENOENT)
|
|
lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
|
|
sizeof(hdr->nexthdr));
|
|
else
|
|
iphc0 |= LOWPAN_IPHC_NH;
|
|
|
|
/* 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_HLIM_01;
|
|
break;
|
|
case 64:
|
|
iphc0 |= LOWPAN_IPHC_HLIM_10;
|
|
break;
|
|
case 255:
|
|
iphc0 |= LOWPAN_IPHC_HLIM_11;
|
|
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, &hdr->saddr,
|
|
saddr, true);
|
|
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;
|
|
iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr, &hdr->daddr);
|
|
} else {
|
|
if (addr_type & IPV6_ADDR_LINKLOCAL) {
|
|
/* TODO: context lookup */
|
|
iphc1 |= lowpan_compress_addr_64(&hc_ptr, &hdr->daddr,
|
|
daddr, false);
|
|
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) {
|
|
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);
|