net/ieee802154/6lowpan.h

   1 /*
   2  * Copyright 2011, Siemens AG
   3  * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
   4  */
   5
   6 /*
   7  * Based on patches from Jon Smirl <jonsmirl@gmail.com>
   8  * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2
  12  * as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  22  */
  23
  24 /* Jon's code is based on 6lowpan implementation for Contiki which is:
  25  * Copyright (c) 2008, Swedish Institute of Computer Science.
  26  * All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. Neither the name of the Institute nor the names of its contributors
  37  *    may be used to endorse or promote products derived from this software
  38  *    without specific prior written permission.
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  */
  52
  53 #ifndef __6LOWPAN_H__
  54 #define __6LOWPAN_H__
  55
  56 #define UIP_802154_SHORTADDR_LEN        2  /* compressed ipv6 address length */
  57 #define UIP_IPH_LEN                     40 /* ipv6 fixed header size */
  58 #define UIP_PROTO_UDP                   17 /* ipv6 next header value for UDP */
  59 #define UIP_FRAGH_LEN                   8  /* ipv6 fragment header size */
  60
  61 /*
  62  * ipv6 address based on mac
  63  * second bit-flip (Universe/Local) is done according RFC2464
  64  */
  65 #define is_addr_mac_addr_based(a, m) \
  66         ((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&   \
  67          (((a)->s6_addr[9])  == (m)[1]) &&              \
  68          (((a)->s6_addr[10]) == (m)[2]) &&              \
  69          (((a)->s6_addr[11]) == (m)[3]) &&              \
  70          (((a)->s6_addr[12]) == (m)[4]) &&              \
  71          (((a)->s6_addr[13]) == (m)[5]) &&              \
  72          (((a)->s6_addr[14]) == (m)[6]) &&              \
  73          (((a)->s6_addr[15]) == (m)[7]))
  74
  75 /* ipv6 address is unspecified */
  76 #define is_addr_unspecified(a)          \
  77         ((((a)->s6_addr32[0]) == 0) &&  \
  78          (((a)->s6_addr32[1]) == 0) &&  \
  79          (((a)->s6_addr32[2]) == 0) &&  \
  80          (((a)->s6_addr32[3]) == 0))
  81
  82 /* compare ipv6 addresses prefixes */
  83 #define ipaddr_prefixcmp(addr1, addr2, length) \
  84         (memcmp(addr1, addr2, length >> 3) == 0)
  85
  86 /* local link, i.e. FE80::/10 */
  87 #define is_addr_link_local(a) (((a)->s6_addr16[0]) == htons(0xFE80))
  88
  89 /*
  90  * check whether we can compress the IID to 16 bits,
  91  * it's possible for unicast adresses with first 49 bits are zero only.
  92  */
  93 #define lowpan_is_iid_16_bit_compressable(a)    \
  94         ((((a)->s6_addr16[4]) == 0) &&          \
  95          (((a)->s6_addr[10]) == 0) &&           \
  96          (((a)->s6_addr[11]) == 0xff) &&        \
  97          (((a)->s6_addr[12]) == 0xfe) &&        \
  98          (((a)->s6_addr[13]) == 0))
  99
 100 /* multicast address */
 101 #define is_addr_mcast(a) (((a)->s6_addr[0]) == 0xFF)
 102
 103 /* check whether the 112-bit gid of the multicast address is mappable to: */
 104
 105 /* 9 bits, for FF02::1 (all nodes) and FF02::2 (all routers) addresses only. */
 106 #define lowpan_is_mcast_addr_compressable(a)    \
 107         ((((a)->s6_addr16[1]) == 0) &&          \
 108          (((a)->s6_addr16[2]) == 0) &&          \
 109          (((a)->s6_addr16[3]) == 0) &&          \
 110          (((a)->s6_addr16[4]) == 0) &&          \
 111          (((a)->s6_addr16[5]) == 0) &&          \
 112          (((a)->s6_addr16[6]) == 0) &&          \
 113          (((a)->s6_addr[14])  == 0) &&          \
 114          ((((a)->s6_addr[15]) == 1) || (((a)->s6_addr[15]) == 2)))
 115
 116 /* 48 bits, FFXX::00XX:XXXX:XXXX */
 117 #define lowpan_is_mcast_addr_compressable48(a)  \
 118         ((((a)->s6_addr16[1]) == 0) &&          \
 119          (((a)->s6_addr16[2]) == 0) &&          \
 120          (((a)->s6_addr16[3]) == 0) &&          \
 121          (((a)->s6_addr16[4]) == 0) &&          \
 122          (((a)->s6_addr[10]) == 0))
 123
 124 /* 32 bits, FFXX::00XX:XXXX */
 125 #define lowpan_is_mcast_addr_compressable32(a)  \
 126         ((((a)->s6_addr16[1]) == 0) &&          \
 127          (((a)->s6_addr16[2]) == 0) &&          \
 128          (((a)->s6_addr16[3]) == 0) &&          \
 129          (((a)->s6_addr16[4]) == 0) &&          \
 130          (((a)->s6_addr16[5]) == 0) &&          \
 131          (((a)->s6_addr[12]) == 0))
 132
 133 /* 8 bits, FF02::00XX */
 134 #define lowpan_is_mcast_addr_compressable8(a)   \
 135         ((((a)->s6_addr[1])  == 2) &&           \
 136          (((a)->s6_addr16[1]) == 0) &&          \
 137          (((a)->s6_addr16[2]) == 0) &&          \
 138          (((a)->s6_addr16[3]) == 0) &&          \
 139          (((a)->s6_addr16[4]) == 0) &&          \
 140          (((a)->s6_addr16[5]) == 0) &&          \
 141          (((a)->s6_addr16[6]) == 0) &&          \
 142          (((a)->s6_addr[14]) == 0))
 143
 144 #define lowpan_is_addr_broadcast(a)     \
 145         ((((a)[0]) == 0xFF) &&  \
 146          (((a)[1]) == 0xFF) &&  \
 147          (((a)[2]) == 0xFF) &&  \
 148          (((a)[3]) == 0xFF) &&  \
 149          (((a)[4]) == 0xFF) &&  \
 150          (((a)[5]) == 0xFF) &&  \
 151          (((a)[6]) == 0xFF) &&  \
 152          (((a)[7]) == 0xFF))
 153
 154 #define LOWPAN_DISPATCH_IPV6    0x41 /* 01000001 = 65 */
 155 #define LOWPAN_DISPATCH_HC1     0x42 /* 01000010 = 66 */
 156 #define LOWPAN_DISPATCH_IPHC    0x60 /* 011xxxxx = ... */
 157 #define LOWPAN_DISPATCH_FRAG1   0xc0 /* 11000xxx */
 158 #define LOWPAN_DISPATCH_FRAGN   0xe0 /* 11100xxx */
 159
 160 #define LOWPAN_DISPATCH_MASK    0xf8 /* 11111000 */
 161
 162 #define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */
 163
 164 #define LOWPAN_FRAG1_HEAD_SIZE  0x4
 165 #define LOWPAN_FRAGN_HEAD_SIZE  0x5
 166
 167 /*
 168  * According IEEE802.15.4 standard:
 169  *   - MTU is 127 octets
 170  *   - maximum MHR size is 37 octets
 171  *   - MFR size is 2 octets
 172  *
 173  * so minimal payload size that we may guarantee is:
 174  *   MTU - MHR - MFR = 88 octets
 175  */
 176 #define LOWPAN_FRAG_SIZE        88
 177
 178 /*
 179  * Values of fields within the IPHC encoding first byte
 180  * (C stands for compressed and I for inline)
 181  */
 182 #define LOWPAN_IPHC_TF          0x18
 183
 184 #define LOWPAN_IPHC_FL_C        0x10
 185 #define LOWPAN_IPHC_TC_C        0x08
 186 #define LOWPAN_IPHC_NH_C        0x04
 187 #define LOWPAN_IPHC_TTL_1       0x01
 188 #define LOWPAN_IPHC_TTL_64      0x02
 189 #define LOWPAN_IPHC_TTL_255     0x03
 190 #define LOWPAN_IPHC_TTL_I       0x00
 191
 192
 193 /* Values of fields within the IPHC encoding second byte */
 194 #define LOWPAN_IPHC_CID         0x80
 195
 196 #define LOWPAN_IPHC_ADDR_00     0x00
 197 #define LOWPAN_IPHC_ADDR_01     0x01
 198 #define LOWPAN_IPHC_ADDR_02     0x02
 199 #define LOWPAN_IPHC_ADDR_03     0x03
 200
 201 #define LOWPAN_IPHC_SAC         0x40
 202 #define LOWPAN_IPHC_SAM         0x30
 203
 204 #define LOWPAN_IPHC_SAM_BIT     4
 205
 206 #define LOWPAN_IPHC_M           0x08
 207 #define LOWPAN_IPHC_DAC         0x04
 208 #define LOWPAN_IPHC_DAM_00      0x00
 209 #define LOWPAN_IPHC_DAM_01      0x01
 210 #define LOWPAN_IPHC_DAM_10      0x02
 211 #define LOWPAN_IPHC_DAM_11      0x03
 212
 213 #define LOWPAN_IPHC_DAM_BIT     0
 214 /*
 215  * LOWPAN_UDP encoding (works together with IPHC)
 216  */
 217 #define LOWPAN_NHC_UDP_MASK             0xF8
 218 #define LOWPAN_NHC_UDP_ID               0xF0
 219 #define LOWPAN_NHC_UDP_CHECKSUMC        0x04
 220 #define LOWPAN_NHC_UDP_CHECKSUMI        0x00
 221
 222 #define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
 223 #define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
 224 #define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
 225 #define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00
 226
 227 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
 228 #define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
 229 #define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
 230                                         dest = 0xF0 + 8 bit inline */
 231 #define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
 232                                         dest = 16 bit inline */
 233 #define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
 234
 235 static inline bool lowpan_fetch_skb(struct sk_buff *skb,
 236                 void *data, const unsigned int len)
 237 {
 238         if (unlikely(!pskb_may_pull(skb, len)))
 239                 return true;
 240
 241         skb_copy_from_linear_data(skb, data, len);
 242         skb_pull(skb, len);
 243
 244         return false;
 245 }
 246
 247 #endif /* __6LOWPAN_H__ */