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 EUI64_ADDR_LEN          8
  65
  66 #define LOWPAN_NHC_MAX_ID_LEN   1
  67 /* Maximum next header compression length which we currently support inclusive
  68  * possible inline data.
  69  */
  70 #define LOWPAN_NHC_MAX_HDR_LEN  (sizeof(struct udphdr))
  71 /* Max IPHC Header len without IPv6 hdr specific inline data.
  72  * Useful for getting the "extra" bytes we need at worst case compression.
  73  *
  74  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
  75  */
  76 #define LOWPAN_IPHC_MAX_HEADER_LEN      (2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
  77 /* Maximum worst case IPHC header buffer size */
  78 #define LOWPAN_IPHC_MAX_HC_BUF_LEN      (sizeof(struct ipv6hdr) +       \
  79                                          LOWPAN_IPHC_MAX_HEADER_LEN +   \
  80                                          LOWPAN_NHC_MAX_HDR_LEN)
  81
  82 /*
  83  * ipv6 address based on mac
  84  * second bit-flip (Universe/Local) is done according RFC2464
  85  */
  86 #define is_addr_mac_addr_based(a, m) \
  87         ((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&   \
  88          (((a)->s6_addr[9])  == (m)[1]) &&              \
  89          (((a)->s6_addr[10]) == (m)[2]) &&              \
  90          (((a)->s6_addr[11]) == (m)[3]) &&              \
  91          (((a)->s6_addr[12]) == (m)[4]) &&              \
  92          (((a)->s6_addr[13]) == (m)[5]) &&              \
  93          (((a)->s6_addr[14]) == (m)[6]) &&              \
  94          (((a)->s6_addr[15]) == (m)[7]))
  95
  96 /*
  97  * check whether we can compress the IID to 16 bits,
  98  * it's possible for unicast adresses with first 49 bits are zero only.
  99  */
 100 #define lowpan_is_iid_16_bit_compressable(a)    \
 101         ((((a)->s6_addr16[4]) == 0) &&          \
 102          (((a)->s6_addr[10]) == 0) &&           \
 103          (((a)->s6_addr[11]) == 0xff) &&        \
 104          (((a)->s6_addr[12]) == 0xfe) &&        \
 105          (((a)->s6_addr[13]) == 0))
 106
 107 /* check whether the 112-bit gid of the multicast address is mappable to: */
 108
 109 /* 48 bits, FFXX::00XX:XXXX:XXXX */
 110 #define lowpan_is_mcast_addr_compressable48(a)  \
 111         ((((a)->s6_addr16[1]) == 0) &&          \
 112          (((a)->s6_addr16[2]) == 0) &&          \
 113          (((a)->s6_addr16[3]) == 0) &&          \
 114          (((a)->s6_addr16[4]) == 0) &&          \
 115          (((a)->s6_addr[10]) == 0))
 116
 117 /* 32 bits, FFXX::00XX:XXXX */
 118 #define lowpan_is_mcast_addr_compressable32(a)  \
 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_addr[12]) == 0))
 125
 126 /* 8 bits, FF02::00XX */
 127 #define lowpan_is_mcast_addr_compressable8(a)   \
 128         ((((a)->s6_addr[1])  == 2) &&           \
 129          (((a)->s6_addr16[1]) == 0) &&          \
 130          (((a)->s6_addr16[2]) == 0) &&          \
 131          (((a)->s6_addr16[3]) == 0) &&          \
 132          (((a)->s6_addr16[4]) == 0) &&          \
 133          (((a)->s6_addr16[5]) == 0) &&          \
 134          (((a)->s6_addr16[6]) == 0) &&          \
 135          (((a)->s6_addr[14]) == 0))
 136
 137 #define lowpan_is_addr_broadcast(a)     \
 138         ((((a)[0]) == 0xFF) &&  \
 139          (((a)[1]) == 0xFF) &&  \
 140          (((a)[2]) == 0xFF) &&  \
 141          (((a)[3]) == 0xFF) &&  \
 142          (((a)[4]) == 0xFF) &&  \
 143          (((a)[5]) == 0xFF) &&  \
 144          (((a)[6]) == 0xFF) &&  \
 145          (((a)[7]) == 0xFF))
 146
 147 #define LOWPAN_DISPATCH_IPV6            0x41 /* 01000001 = 65 */
 148 #define LOWPAN_DISPATCH_IPHC            0x60 /* 011xxxxx = ... */
 149 #define LOWPAN_DISPATCH_IPHC_MASK       0xe0
 150
 151 static inline bool lowpan_is_ipv6(u8 dispatch)
 152 {
 153         return dispatch == LOWPAN_DISPATCH_IPV6;
 154 }
 155
 156 static inline bool lowpan_is_iphc(u8 dispatch)
 157 {
 158         return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
 159 }
 160
 161 #define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */
 162
 163 #define LOWPAN_FRAG1_HEAD_SIZE  0x4
 164 #define LOWPAN_FRAGN_HEAD_SIZE  0x5
 165
 166 /*
 167  * Values of fields within the IPHC encoding first byte
 168  * (C stands for compressed and I for inline)
 169  */
 170 #define LOWPAN_IPHC_TF          0x18
 171
 172 #define LOWPAN_IPHC_FL_C        0x10
 173 #define LOWPAN_IPHC_TC_C        0x08
 174 #define LOWPAN_IPHC_NH_C        0x04
 175 #define LOWPAN_IPHC_TTL_1       0x01
 176 #define LOWPAN_IPHC_TTL_64      0x02
 177 #define LOWPAN_IPHC_TTL_255     0x03
 178 #define LOWPAN_IPHC_TTL_I       0x00
 179
 180
 181 /* Values of fields within the IPHC encoding second byte */
 182 #define LOWPAN_IPHC_CID         0x80
 183
 184 #define LOWPAN_IPHC_ADDR_00     0x00
 185 #define LOWPAN_IPHC_ADDR_01     0x01
 186 #define LOWPAN_IPHC_ADDR_02     0x02
 187 #define LOWPAN_IPHC_ADDR_03     0x03
 188
 189 #define LOWPAN_IPHC_SAC         0x40
 190 #define LOWPAN_IPHC_SAM         0x30
 191
 192 #define LOWPAN_IPHC_SAM_BIT     4
 193
 194 #define LOWPAN_IPHC_M           0x08
 195 #define LOWPAN_IPHC_DAC         0x04
 196 #define LOWPAN_IPHC_DAM_00      0x00
 197 #define LOWPAN_IPHC_DAM_01      0x01
 198 #define LOWPAN_IPHC_DAM_10      0x02
 199 #define LOWPAN_IPHC_DAM_11      0x03
 200
 201 #define LOWPAN_IPHC_DAM_BIT     0
 202 /*
 203  * LOWPAN_UDP encoding (works together with IPHC)
 204  */
 205 #define LOWPAN_NHC_UDP_MASK             0xF8
 206 #define LOWPAN_NHC_UDP_ID               0xF0
 207 #define LOWPAN_NHC_UDP_CHECKSUMC        0x04
 208 #define LOWPAN_NHC_UDP_CHECKSUMI        0x00
 209
 210 #define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
 211 #define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
 212 #define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
 213 #define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00
 214
 215 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
 216 #define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
 217 #define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
 218                                         dest = 0xF0 + 8 bit inline */
 219 #define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
 220                                         dest = 16 bit inline */
 221 #define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
 222 #define LOWPAN_NHC_UDP_CS_C     0x04 /* checksum elided */
 223
 224 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
 225         (sizeof(struct lowpan_priv) + llpriv_size)
 226
 227 enum lowpan_lltypes {
 228         LOWPAN_LLTYPE_BTLE,
 229         LOWPAN_LLTYPE_IEEE802154,
 230 };
 231
 232 struct lowpan_priv {
 233         enum lowpan_lltypes lltype;
 234
 235         /* must be last */
 236         u8 priv[0] __aligned(sizeof(void *));
 237 };
 238
 239 static inline
 240 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 241 {
 242         return netdev_priv(dev);
 243 }
 244
 245 struct lowpan_802154_cb {
 246         u16 d_tag;
 247         unsigned int d_size;
 248         u8 d_offset;
 249 };
 250
 251 static inline
 252 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
 253 {
 254         BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
 255         return (struct lowpan_802154_cb *)skb->cb;
 256 }
 257
 258 #ifdef DEBUG
 259 /* print data in line */
 260 static inline void raw_dump_inline(const char *caller, char *msg,
 261                                    const unsigned char *buf, int len)
 262 {
 263         if (msg)
 264                 pr_debug("%s():%s: ", caller, msg);
 265
 266         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 267 }
 268
 269 /* print data in a table format:
 270  *
 271  * addr: xx xx xx xx xx xx
 272  * addr: xx xx xx xx xx xx
 273  * ...
 274  */
 275 static inline void raw_dump_table(const char *caller, char *msg,
 276                                   const unsigned char *buf, int len)
 277 {
 278         if (msg)
 279                 pr_debug("%s():%s:\n", caller, msg);
 280
 281         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 282 }
 283 #else
 284 static inline void raw_dump_table(const char *caller, char *msg,
 285                                   const unsigned char *buf, int len) { }
 286 static inline void raw_dump_inline(const char *caller, char *msg,
 287                                    const unsigned char *buf, int len) { }
 288 #endif
 289
 290 /**
 291  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
 292  *
 293  * This function will pull data from sk buffer and put it into data to
 294  * remove the 6LoWPAN inline data. This function returns true if the
 295  * sk buffer is too small to pull the amount of data which is specified
 296  * by len.
 297  *
 298  * @skb: the buffer where the inline data should be pulled from.
 299  * @data: destination buffer for the inline data.
 300  * @len: amount of data which should be pulled in bytes.
 301  */
 302 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
 303                                     unsigned int len)
 304 {
 305         if (unlikely(!pskb_may_pull(skb, len)))
 306                 return true;
 307
 308         skb_copy_from_linear_data(skb, data, len);
 309         skb_pull(skb, len);
 310
 311         return false;
 312 }
 313
 314 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 315                                        const size_t len)
 316 {
 317         memcpy(*hc_ptr, data, len);
 318         *hc_ptr += len;
 319 }
 320
 321 void lowpan_netdev_setup(struct net_device *dev, enum lowpan_lltypes lltype);
 322
 323 /**
 324  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
 325  *
 326  * This function replaces the IPHC 6LoWPAN header which should be pointed at
 327  * skb->data and skb_network_header, with the IPv6 header.
 328  * It would be nice that the caller have the necessary headroom of IPv6 header
 329  * and greatest Transport layer header, this would reduce the overhead for
 330  * reallocate headroom.
 331  *
 332  * @skb: the buffer which should be manipulate.
 333  * @dev: the lowpan net device pointer.
 334  * @daddr: destination lladdr of mac header which is used for compression
 335  *      methods.
 336  * @saddr: source lladdr of mac header which is used for compression
 337  *      methods.
 338  */
 339 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
 340                              const void *daddr, const void *saddr);
 341
 342 /**
 343  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
 344  *
 345  * This function replaces the IPv6 header which should be pointed at
 346  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
 347  * The caller need to be sure that the sk buffer is not shared and at have
 348  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
 349  * which is the IPHC "more bytes than IPv6 header" at worst case.
 350  *
 351  * @skb: the buffer which should be manipulate.
 352  * @dev: the lowpan net device pointer.
 353  * @daddr: destination lladdr of mac header which is used for compression
 354  *      methods.
 355  * @saddr: source lladdr of mac header which is used for compression
 356  *      methods.
 357  */
 358 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
 359                            const void *daddr, const void *saddr);
 360
 361 #endif /* __6LOWPAN_H__ */