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 /*
  65  * ipv6 address based on mac
  66  * second bit-flip (Universe/Local) is done according RFC2464
  67  */
  68 #define is_addr_mac_addr_based(a, m) \
  69         ((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&   \
  70          (((a)->s6_addr[9])  == (m)[1]) &&              \
  71          (((a)->s6_addr[10]) == (m)[2]) &&              \
  72          (((a)->s6_addr[11]) == (m)[3]) &&              \
  73          (((a)->s6_addr[12]) == (m)[4]) &&              \
  74          (((a)->s6_addr[13]) == (m)[5]) &&              \
  75          (((a)->s6_addr[14]) == (m)[6]) &&              \
  76          (((a)->s6_addr[15]) == (m)[7]))
  77
  78 /*
  79  * check whether we can compress the IID to 16 bits,
  80  * it's possible for unicast adresses with first 49 bits are zero only.
  81  */
  82 #define lowpan_is_iid_16_bit_compressable(a)    \
  83         ((((a)->s6_addr16[4]) == 0) &&          \
  84          (((a)->s6_addr[10]) == 0) &&           \
  85          (((a)->s6_addr[11]) == 0xff) &&        \
  86          (((a)->s6_addr[12]) == 0xfe) &&        \
  87          (((a)->s6_addr[13]) == 0))
  88
  89 /* check whether the 112-bit gid of the multicast address is mappable to: */
  90
  91 /* 48 bits, FFXX::00XX:XXXX:XXXX */
  92 #define lowpan_is_mcast_addr_compressable48(a)  \
  93         ((((a)->s6_addr16[1]) == 0) &&          \
  94          (((a)->s6_addr16[2]) == 0) &&          \
  95          (((a)->s6_addr16[3]) == 0) &&          \
  96          (((a)->s6_addr16[4]) == 0) &&          \
  97          (((a)->s6_addr[10]) == 0))
  98
  99 /* 32 bits, FFXX::00XX:XXXX */
 100 #define lowpan_is_mcast_addr_compressable32(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_addr16[5]) == 0) &&          \
 106          (((a)->s6_addr[12]) == 0))
 107
 108 /* 8 bits, FF02::00XX */
 109 #define lowpan_is_mcast_addr_compressable8(a)   \
 110         ((((a)->s6_addr[1])  == 2) &&           \
 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_addr16[5]) == 0) &&          \
 116          (((a)->s6_addr16[6]) == 0) &&          \
 117          (((a)->s6_addr[14]) == 0))
 118
 119 #define lowpan_is_addr_broadcast(a)     \
 120         ((((a)[0]) == 0xFF) &&  \
 121          (((a)[1]) == 0xFF) &&  \
 122          (((a)[2]) == 0xFF) &&  \
 123          (((a)[3]) == 0xFF) &&  \
 124          (((a)[4]) == 0xFF) &&  \
 125          (((a)[5]) == 0xFF) &&  \
 126          (((a)[6]) == 0xFF) &&  \
 127          (((a)[7]) == 0xFF))
 128
 129 #define LOWPAN_DISPATCH_IPV6    0x41 /* 01000001 = 65 */
 130 #define LOWPAN_DISPATCH_HC1     0x42 /* 01000010 = 66 */
 131 #define LOWPAN_DISPATCH_IPHC    0x60 /* 011xxxxx = ... */
 132 #define LOWPAN_DISPATCH_FRAG1   0xc0 /* 11000xxx */
 133 #define LOWPAN_DISPATCH_FRAGN   0xe0 /* 11100xxx */
 134
 135 #define LOWPAN_DISPATCH_MASK    0xf8 /* 11111000 */
 136
 137 #define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */
 138
 139 #define LOWPAN_FRAG1_HEAD_SIZE  0x4
 140 #define LOWPAN_FRAGN_HEAD_SIZE  0x5
 141
 142 /*
 143  * Values of fields within the IPHC encoding first byte
 144  * (C stands for compressed and I for inline)
 145  */
 146 #define LOWPAN_IPHC_TF          0x18
 147
 148 #define LOWPAN_IPHC_FL_C        0x10
 149 #define LOWPAN_IPHC_TC_C        0x08
 150 #define LOWPAN_IPHC_NH_C        0x04
 151 #define LOWPAN_IPHC_TTL_1       0x01
 152 #define LOWPAN_IPHC_TTL_64      0x02
 153 #define LOWPAN_IPHC_TTL_255     0x03
 154 #define LOWPAN_IPHC_TTL_I       0x00
 155
 156
 157 /* Values of fields within the IPHC encoding second byte */
 158 #define LOWPAN_IPHC_CID         0x80
 159
 160 #define LOWPAN_IPHC_ADDR_00     0x00
 161 #define LOWPAN_IPHC_ADDR_01     0x01
 162 #define LOWPAN_IPHC_ADDR_02     0x02
 163 #define LOWPAN_IPHC_ADDR_03     0x03
 164
 165 #define LOWPAN_IPHC_SAC         0x40
 166 #define LOWPAN_IPHC_SAM         0x30
 167
 168 #define LOWPAN_IPHC_SAM_BIT     4
 169
 170 #define LOWPAN_IPHC_M           0x08
 171 #define LOWPAN_IPHC_DAC         0x04
 172 #define LOWPAN_IPHC_DAM_00      0x00
 173 #define LOWPAN_IPHC_DAM_01      0x01
 174 #define LOWPAN_IPHC_DAM_10      0x02
 175 #define LOWPAN_IPHC_DAM_11      0x03
 176
 177 #define LOWPAN_IPHC_DAM_BIT     0
 178 /*
 179  * LOWPAN_UDP encoding (works together with IPHC)
 180  */
 181 #define LOWPAN_NHC_UDP_MASK             0xF8
 182 #define LOWPAN_NHC_UDP_ID               0xF0
 183 #define LOWPAN_NHC_UDP_CHECKSUMC        0x04
 184 #define LOWPAN_NHC_UDP_CHECKSUMI        0x00
 185
 186 #define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
 187 #define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
 188 #define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
 189 #define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00
 190
 191 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
 192 #define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
 193 #define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
 194                                         dest = 0xF0 + 8 bit inline */
 195 #define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
 196                                         dest = 16 bit inline */
 197 #define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
 198 #define LOWPAN_NHC_UDP_CS_C     0x04 /* checksum elided */
 199
 200 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
 201         (sizeof(struct lowpan_priv) + llpriv_size)
 202
 203 enum lowpan_lltypes {
 204         LOWPAN_LLTYPE_BTLE,
 205         LOWPAN_LLTYPE_IEEE802154,
 206 };
 207
 208 struct lowpan_priv {
 209         enum lowpan_lltypes lltype;
 210
 211         /* must be last */
 212         u8 priv[0] __aligned(sizeof(void *));
 213 };
 214
 215 static inline
 216 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 217 {
 218         return netdev_priv(dev);
 219 }
 220
 221 #ifdef DEBUG
 222 /* print data in line */
 223 static inline void raw_dump_inline(const char *caller, char *msg,
 224                                    unsigned char *buf, int len)
 225 {
 226         if (msg)
 227                 pr_debug("%s():%s: ", caller, msg);
 228
 229         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 230 }
 231
 232 /* print data in a table format:
 233  *
 234  * addr: xx xx xx xx xx xx
 235  * addr: xx xx xx xx xx xx
 236  * ...
 237  */
 238 static inline void raw_dump_table(const char *caller, char *msg,
 239                                   unsigned char *buf, int len)
 240 {
 241         if (msg)
 242                 pr_debug("%s():%s:\n", caller, msg);
 243
 244         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 245 }
 246 #else
 247 static inline void raw_dump_table(const char *caller, char *msg,
 248                                   unsigned char *buf, int len) { }
 249 static inline void raw_dump_inline(const char *caller, char *msg,
 250                                    unsigned char *buf, int len) { }
 251 #endif
 252
 253 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 254 {
 255         if (unlikely(!pskb_may_pull(skb, 1)))
 256                 return -EINVAL;
 257
 258         *val = skb->data[0];
 259         skb_pull(skb, 1);
 260
 261         return 0;
 262 }
 263
 264 static inline bool lowpan_fetch_skb(struct sk_buff *skb,
 265                 void *data, const unsigned int len)
 266 {
 267         if (unlikely(!pskb_may_pull(skb, len)))
 268                 return true;
 269
 270         skb_copy_from_linear_data(skb, data, len);
 271         skb_pull(skb, len);
 272
 273         return false;
 274 }
 275
 276 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 277                                        const size_t len)
 278 {
 279         memcpy(*hc_ptr, data, len);
 280         *hc_ptr += len;
 281 }
 282
 283 static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
 284 {
 285         static const u8 addr_sizes[] = {
 286                 [LOWPAN_IPHC_ADDR_00] = 16,
 287                 [LOWPAN_IPHC_ADDR_01] = 8,
 288                 [LOWPAN_IPHC_ADDR_02] = 2,
 289                 [LOWPAN_IPHC_ADDR_03] = 0,
 290         };
 291         return addr_sizes[addr_mode];
 292 }
 293
 294 static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
 295 {
 296         u8 ret = 1;
 297
 298         if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 299                 *uncomp_header += sizeof(struct udphdr);
 300
 301                 switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
 302                 case LOWPAN_NHC_UDP_CS_P_00:
 303                         ret += 4;
 304                         break;
 305                 case LOWPAN_NHC_UDP_CS_P_01:
 306                 case LOWPAN_NHC_UDP_CS_P_10:
 307                         ret += 3;
 308                         break;
 309                 case LOWPAN_NHC_UDP_CS_P_11:
 310                         ret++;
 311                         break;
 312                 default:
 313                         break;
 314                 }
 315
 316                 if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
 317                         ret += 2;
 318         }
 319
 320         return ret;
 321 }
 322
 323 /**
 324  *      lowpan_uncompress_size - returns skb->len size with uncompressed header
 325  *      @skb: sk_buff with 6lowpan header inside
 326  *      @datagram_offset: optional to get the datagram_offset value
 327  *
 328  *      Returns the skb->len with uncompressed header
 329  */
 330 static inline u16
 331 lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
 332 {
 333         u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
 334         u8 iphc0, iphc1, h_enc;
 335
 336         iphc0 = skb_network_header(skb)[0];
 337         iphc1 = skb_network_header(skb)[1];
 338
 339         switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 340         case 0:
 341                 ret += 4;
 342                 break;
 343         case 1:
 344                 ret += 3;
 345                 break;
 346         case 2:
 347                 ret++;
 348                 break;
 349         default:
 350                 break;
 351         }
 352
 353         if (!(iphc0 & LOWPAN_IPHC_NH_C))
 354                 ret++;
 355
 356         if (!(iphc0 & 0x03))
 357                 ret++;
 358
 359         ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
 360                                      LOWPAN_IPHC_SAM_BIT);
 361
 362         if (iphc1 & LOWPAN_IPHC_M) {
 363                 switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
 364                         LOWPAN_IPHC_DAM_BIT) {
 365                 case LOWPAN_IPHC_DAM_00:
 366                         ret += 16;
 367                         break;
 368                 case LOWPAN_IPHC_DAM_01:
 369                         ret += 6;
 370                         break;
 371                 case LOWPAN_IPHC_DAM_10:
 372                         ret += 4;
 373                         break;
 374                 case LOWPAN_IPHC_DAM_11:
 375                         ret++;
 376                         break;
 377                 default:
 378                         break;
 379                 }
 380         } else {
 381                 ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
 382                                              LOWPAN_IPHC_DAM_BIT);
 383         }
 384
 385         if (iphc0 & LOWPAN_IPHC_NH_C) {
 386                 h_enc = skb_network_header(skb)[ret];
 387                 ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
 388         }
 389
 390         if (dgram_offset)
 391                 *dgram_offset = uncomp_header;
 392
 393         return skb->len + uncomp_header - ret;
 394 }
 395
 396 void lowpan_netdev_setup(struct net_device *dev, enum lowpan_lltypes lltype);
 397
 398 int
 399 lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
 400                          const u8 *saddr, const u8 saddr_type,
 401                          const u8 saddr_len, const u8 *daddr,
 402                          const u8 daddr_type, const u8 daddr_len,
 403                          u8 iphc0, u8 iphc1);
 404 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 405                         unsigned short type, const void *_daddr,
 406                         const void *_saddr, unsigned int len);
 407
 408 #endif /* __6LOWPAN_H__ */