include/net/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 #include <net/ipv6.h>
  57 #include <net/net_namespace.h>
  58
  59 #define UIP_802154_SHORTADDR_LEN        2  /* compressed ipv6 address length */
  60 #define UIP_IPH_LEN                     40 /* ipv6 fixed header size */
  61 #define UIP_PROTO_UDP                   17 /* ipv6 next header value for UDP */
  62 #define UIP_FRAGH_LEN                   8  /* ipv6 fragment header size */
  63
  64 #define LOWPAN_NHC_MAX_ID_LEN   1
  65 /* Max IPHC Header len without IPv6 hdr specific inline data.
  66  * Useful for getting the "extra" bytes we need at worst case compression.
  67  *
  68  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
  69  */
  70 #define LOWPAN_IPHC_MAX_HEADER_LEN      (2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
  71
  72 /*
  73  * ipv6 address based on mac
  74  * second bit-flip (Universe/Local) is done according RFC2464
  75  */
  76 #define is_addr_mac_addr_based(a, m) \
  77         ((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&   \
  78          (((a)->s6_addr[9])  == (m)[1]) &&              \
  79          (((a)->s6_addr[10]) == (m)[2]) &&              \
  80          (((a)->s6_addr[11]) == (m)[3]) &&              \
  81          (((a)->s6_addr[12]) == (m)[4]) &&              \
  82          (((a)->s6_addr[13]) == (m)[5]) &&              \
  83          (((a)->s6_addr[14]) == (m)[6]) &&              \
  84          (((a)->s6_addr[15]) == (m)[7]))
  85
  86 /*
  87  * check whether we can compress the IID to 16 bits,
  88  * it's possible for unicast adresses with first 49 bits are zero only.
  89  */
  90 #define lowpan_is_iid_16_bit_compressable(a)    \
  91         ((((a)->s6_addr16[4]) == 0) &&          \
  92          (((a)->s6_addr[10]) == 0) &&           \
  93          (((a)->s6_addr[11]) == 0xff) &&        \
  94          (((a)->s6_addr[12]) == 0xfe) &&        \
  95          (((a)->s6_addr[13]) == 0))
  96
  97 /* check whether the 112-bit gid of the multicast address is mappable to: */
  98
  99 /* 48 bits, FFXX::00XX:XXXX:XXXX */
 100 #define lowpan_is_mcast_addr_compressable48(a)  \
 101         ((((a)->s6_addr16[1]) == 0) &&          \
 102          (((a)->s6_addr16[2]) == 0) &&          \
 103          (((a)->s6_addr16[3]) == 0) &&          \
 104          (((a)->s6_addr16[4]) == 0) &&          \
 105          (((a)->s6_addr[10]) == 0))
 106
 107 /* 32 bits, FFXX::00XX:XXXX */
 108 #define lowpan_is_mcast_addr_compressable32(a)  \
 109         ((((a)->s6_addr16[1]) == 0) &&          \
 110          (((a)->s6_addr16[2]) == 0) &&          \
 111          (((a)->s6_addr16[3]) == 0) &&          \
 112          (((a)->s6_addr16[4]) == 0) &&          \
 113          (((a)->s6_addr16[5]) == 0) &&          \
 114          (((a)->s6_addr[12]) == 0))
 115
 116 /* 8 bits, FF02::00XX */
 117 #define lowpan_is_mcast_addr_compressable8(a)   \
 118         ((((a)->s6_addr[1])  == 2) &&           \
 119          (((a)->s6_addr16[1]) == 0) &&          \
 120          (((a)->s6_addr16[2]) == 0) &&          \
 121          (((a)->s6_addr16[3]) == 0) &&          \
 122          (((a)->s6_addr16[4]) == 0) &&          \
 123          (((a)->s6_addr16[5]) == 0) &&          \
 124          (((a)->s6_addr16[6]) == 0) &&          \
 125          (((a)->s6_addr[14]) == 0))
 126
 127 #define lowpan_is_addr_broadcast(a)     \
 128         ((((a)[0]) == 0xFF) &&  \
 129          (((a)[1]) == 0xFF) &&  \
 130          (((a)[2]) == 0xFF) &&  \
 131          (((a)[3]) == 0xFF) &&  \
 132          (((a)[4]) == 0xFF) &&  \
 133          (((a)[5]) == 0xFF) &&  \
 134          (((a)[6]) == 0xFF) &&  \
 135          (((a)[7]) == 0xFF))
 136
 137 #define LOWPAN_DISPATCH_IPV6            0x41 /* 01000001 = 65 */
 138 #define LOWPAN_DISPATCH_IPHC            0x60 /* 011xxxxx = ... */
 139 #define LOWPAN_DISPATCH_IPHC_MASK       0xe0
 140
 141 static inline bool lowpan_is_ipv6(u8 dispatch)
 142 {
 143         return dispatch == LOWPAN_DISPATCH_IPV6;
 144 }
 145
 146 static inline bool lowpan_is_iphc(u8 dispatch)
 147 {
 148         return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
 149 }
 150
 151 #define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */
 152
 153 #define LOWPAN_FRAG1_HEAD_SIZE  0x4
 154 #define LOWPAN_FRAGN_HEAD_SIZE  0x5
 155
 156 /*
 157  * Values of fields within the IPHC encoding first byte
 158  * (C stands for compressed and I for inline)
 159  */
 160 #define LOWPAN_IPHC_TF          0x18
 161
 162 #define LOWPAN_IPHC_FL_C        0x10
 163 #define LOWPAN_IPHC_TC_C        0x08
 164 #define LOWPAN_IPHC_NH_C        0x04
 165 #define LOWPAN_IPHC_TTL_1       0x01
 166 #define LOWPAN_IPHC_TTL_64      0x02
 167 #define LOWPAN_IPHC_TTL_255     0x03
 168 #define LOWPAN_IPHC_TTL_I       0x00
 169
 170
 171 /* Values of fields within the IPHC encoding second byte */
 172 #define LOWPAN_IPHC_CID         0x80
 173
 174 #define LOWPAN_IPHC_ADDR_00     0x00
 175 #define LOWPAN_IPHC_ADDR_01     0x01
 176 #define LOWPAN_IPHC_ADDR_02     0x02
 177 #define LOWPAN_IPHC_ADDR_03     0x03
 178
 179 #define LOWPAN_IPHC_SAC         0x40
 180 #define LOWPAN_IPHC_SAM         0x30
 181
 182 #define LOWPAN_IPHC_SAM_BIT     4
 183
 184 #define LOWPAN_IPHC_M           0x08
 185 #define LOWPAN_IPHC_DAC         0x04
 186 #define LOWPAN_IPHC_DAM_00      0x00
 187 #define LOWPAN_IPHC_DAM_01      0x01
 188 #define LOWPAN_IPHC_DAM_10      0x02
 189 #define LOWPAN_IPHC_DAM_11      0x03
 190
 191 #define LOWPAN_IPHC_DAM_BIT     0
 192 /*
 193  * LOWPAN_UDP encoding (works together with IPHC)
 194  */
 195 #define LOWPAN_NHC_UDP_MASK             0xF8
 196 #define LOWPAN_NHC_UDP_ID               0xF0
 197 #define LOWPAN_NHC_UDP_CHECKSUMC        0x04
 198 #define LOWPAN_NHC_UDP_CHECKSUMI        0x00
 199
 200 #define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
 201 #define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
 202 #define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
 203 #define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00
 204
 205 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
 206 #define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
 207 #define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
 208                                         dest = 0xF0 + 8 bit inline */
 209 #define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
 210                                         dest = 16 bit inline */
 211 #define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
 212 #define LOWPAN_NHC_UDP_CS_C     0x04 /* checksum elided */
 213
 214 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
 215         (sizeof(struct lowpan_priv) + llpriv_size)
 216
 217 enum lowpan_lltypes {
 218         LOWPAN_LLTYPE_BTLE,
 219         LOWPAN_LLTYPE_IEEE802154,
 220 };
 221
 222 struct lowpan_priv {
 223         enum lowpan_lltypes lltype;
 224
 225         /* must be last */
 226         u8 priv[0] __aligned(sizeof(void *));
 227 };
 228
 229 static inline
 230 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 231 {
 232         return netdev_priv(dev);
 233 }
 234
 235 struct lowpan_802154_cb {
 236         u16 d_tag;
 237         unsigned int d_size;
 238         u8 d_offset;
 239 };
 240
 241 static inline
 242 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
 243 {
 244         BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
 245         return (struct lowpan_802154_cb *)skb->cb;
 246 }
 247
 248 #ifdef DEBUG
 249 /* print data in line */
 250 static inline void raw_dump_inline(const char *caller, char *msg,
 251                                    unsigned char *buf, int len)
 252 {
 253         if (msg)
 254                 pr_debug("%s():%s: ", caller, msg);
 255
 256         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 257 }
 258
 259 /* print data in a table format:
 260  *
 261  * addr: xx xx xx xx xx xx
 262  * addr: xx xx xx xx xx xx
 263  * ...
 264  */
 265 static inline void raw_dump_table(const char *caller, char *msg,
 266                                   unsigned char *buf, int len)
 267 {
 268         if (msg)
 269                 pr_debug("%s():%s:\n", caller, msg);
 270
 271         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 272 }
 273 #else
 274 static inline void raw_dump_table(const char *caller, char *msg,
 275                                   unsigned char *buf, int len) { }
 276 static inline void raw_dump_inline(const char *caller, char *msg,
 277                                    unsigned char *buf, int len) { }
 278 #endif
 279
 280 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 281 {
 282         if (unlikely(!pskb_may_pull(skb, 1)))
 283                 return -EINVAL;
 284
 285         *val = skb->data[0];
 286         skb_pull(skb, 1);
 287
 288         return 0;
 289 }
 290
 291 static inline bool lowpan_fetch_skb(struct sk_buff *skb,
 292                 void *data, const unsigned int len)
 293 {
 294         if (unlikely(!pskb_may_pull(skb, len)))
 295                 return true;
 296
 297         skb_copy_from_linear_data(skb, data, len);
 298         skb_pull(skb, len);
 299
 300         return false;
 301 }
 302
 303 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 304                                        const size_t len)
 305 {
 306         memcpy(*hc_ptr, data, len);
 307         *hc_ptr += len;
 308 }
 309
 310 void lowpan_netdev_setup(struct net_device *dev, enum lowpan_lltypes lltype);
 311
 312 int
 313 lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
 314                          const u8 *saddr, const u8 saddr_type,
 315                          const u8 saddr_len, const u8 *daddr,
 316                          const u8 daddr_type, const u8 daddr_len,
 317                          u8 iphc0, u8 iphc1);
 318 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 319                         unsigned short type, const void *_daddr,
 320                         const void *_saddr, unsigned int len);
 321
 322 #endif /* __6LOWPAN_H__ */