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 /* ipv6 address is unspecified */
  79 #define is_addr_unspecified(a)          \
  80         ((((a)->s6_addr32[0]) == 0) &&  \
  81          (((a)->s6_addr32[1]) == 0) &&  \
  82          (((a)->s6_addr32[2]) == 0) &&  \
  83          (((a)->s6_addr32[3]) == 0))
  84
  85 /* compare ipv6 addresses prefixes */
  86 #define ipaddr_prefixcmp(addr1, addr2, length) \
  87         (memcmp(addr1, addr2, length >> 3) == 0)
  88
  89 /* local link, i.e. FE80::/10 */
  90 #define is_addr_link_local(a) (((a)->s6_addr16[0]) == htons(0xFE80))
  91
  92 /*
  93  * check whether we can compress the IID to 16 bits,
  94  * it's possible for unicast adresses with first 49 bits are zero only.
  95  */
  96 #define lowpan_is_iid_16_bit_compressable(a)    \
  97         ((((a)->s6_addr16[4]) == 0) &&          \
  98          (((a)->s6_addr[10]) == 0) &&           \
  99          (((a)->s6_addr[11]) == 0xff) &&        \
 100          (((a)->s6_addr[12]) == 0xfe) &&        \
 101          (((a)->s6_addr[13]) == 0))
 102
 103 /* multicast address */
 104 #define is_addr_mcast(a) (((a)->s6_addr[0]) == 0xFF)
 105
 106 /* check whether the 112-bit gid of the multicast address is mappable to: */
 107
 108 /* 9 bits, for FF02::1 (all nodes) and FF02::2 (all routers) addresses only. */
 109 #define lowpan_is_mcast_addr_compressable(a)    \
 110         ((((a)->s6_addr16[1]) == 0) &&          \
 111          (((a)->s6_addr16[2]) == 0) &&          \
 112          (((a)->s6_addr16[3]) == 0) &&          \
 113          (((a)->s6_addr16[4]) == 0) &&          \
 114          (((a)->s6_addr16[5]) == 0) &&          \
 115          (((a)->s6_addr16[6]) == 0) &&          \
 116          (((a)->s6_addr[14])  == 0) &&          \
 117          ((((a)->s6_addr[15]) == 1) || (((a)->s6_addr[15]) == 2)))
 118
 119 /* 48 bits, FFXX::00XX:XXXX:XXXX */
 120 #define lowpan_is_mcast_addr_compressable48(a)  \
 121         ((((a)->s6_addr16[1]) == 0) &&          \
 122          (((a)->s6_addr16[2]) == 0) &&          \
 123          (((a)->s6_addr16[3]) == 0) &&          \
 124          (((a)->s6_addr16[4]) == 0) &&          \
 125          (((a)->s6_addr[10]) == 0))
 126
 127 /* 32 bits, FFXX::00XX:XXXX */
 128 #define lowpan_is_mcast_addr_compressable32(a)  \
 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_addr[12]) == 0))
 135
 136 /* 8 bits, FF02::00XX */
 137 #define lowpan_is_mcast_addr_compressable8(a)   \
 138         ((((a)->s6_addr[1])  == 2) &&           \
 139          (((a)->s6_addr16[1]) == 0) &&          \
 140          (((a)->s6_addr16[2]) == 0) &&          \
 141          (((a)->s6_addr16[3]) == 0) &&          \
 142          (((a)->s6_addr16[4]) == 0) &&          \
 143          (((a)->s6_addr16[5]) == 0) &&          \
 144          (((a)->s6_addr16[6]) == 0) &&          \
 145          (((a)->s6_addr[14]) == 0))
 146
 147 #define lowpan_is_addr_broadcast(a)     \
 148         ((((a)[0]) == 0xFF) &&  \
 149          (((a)[1]) == 0xFF) &&  \
 150          (((a)[2]) == 0xFF) &&  \
 151          (((a)[3]) == 0xFF) &&  \
 152          (((a)[4]) == 0xFF) &&  \
 153          (((a)[5]) == 0xFF) &&  \
 154          (((a)[6]) == 0xFF) &&  \
 155          (((a)[7]) == 0xFF))
 156
 157 #define LOWPAN_DISPATCH_IPV6    0x41 /* 01000001 = 65 */
 158 #define LOWPAN_DISPATCH_HC1     0x42 /* 01000010 = 66 */
 159 #define LOWPAN_DISPATCH_IPHC    0x60 /* 011xxxxx = ... */
 160 #define LOWPAN_DISPATCH_FRAG1   0xc0 /* 11000xxx */
 161 #define LOWPAN_DISPATCH_FRAGN   0xe0 /* 11100xxx */
 162
 163 #define LOWPAN_DISPATCH_MASK    0xf8 /* 11111000 */
 164
 165 #define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */
 166
 167 #define LOWPAN_FRAG1_HEAD_SIZE  0x4
 168 #define LOWPAN_FRAGN_HEAD_SIZE  0x5
 169
 170 /*
 171  * According IEEE802.15.4 standard:
 172  *   - MTU is 127 octets
 173  *   - maximum MHR size is 37 octets
 174  *   - MFR size is 2 octets
 175  *
 176  * so minimal payload size that we may guarantee is:
 177  *   MTU - MHR - MFR = 88 octets
 178  */
 179 #define LOWPAN_FRAG_SIZE        88
 180
 181 /*
 182  * Values of fields within the IPHC encoding first byte
 183  * (C stands for compressed and I for inline)
 184  */
 185 #define LOWPAN_IPHC_TF          0x18
 186
 187 #define LOWPAN_IPHC_FL_C        0x10
 188 #define LOWPAN_IPHC_TC_C        0x08
 189 #define LOWPAN_IPHC_NH_C        0x04
 190 #define LOWPAN_IPHC_TTL_1       0x01
 191 #define LOWPAN_IPHC_TTL_64      0x02
 192 #define LOWPAN_IPHC_TTL_255     0x03
 193 #define LOWPAN_IPHC_TTL_I       0x00
 194
 195
 196 /* Values of fields within the IPHC encoding second byte */
 197 #define LOWPAN_IPHC_CID         0x80
 198
 199 #define LOWPAN_IPHC_ADDR_00     0x00
 200 #define LOWPAN_IPHC_ADDR_01     0x01
 201 #define LOWPAN_IPHC_ADDR_02     0x02
 202 #define LOWPAN_IPHC_ADDR_03     0x03
 203
 204 #define LOWPAN_IPHC_SAC         0x40
 205 #define LOWPAN_IPHC_SAM         0x30
 206
 207 #define LOWPAN_IPHC_SAM_BIT     4
 208
 209 #define LOWPAN_IPHC_M           0x08
 210 #define LOWPAN_IPHC_DAC         0x04
 211 #define LOWPAN_IPHC_DAM_00      0x00
 212 #define LOWPAN_IPHC_DAM_01      0x01
 213 #define LOWPAN_IPHC_DAM_10      0x02
 214 #define LOWPAN_IPHC_DAM_11      0x03
 215
 216 #define LOWPAN_IPHC_DAM_BIT     0
 217 /*
 218  * LOWPAN_UDP encoding (works together with IPHC)
 219  */
 220 #define LOWPAN_NHC_UDP_MASK             0xF8
 221 #define LOWPAN_NHC_UDP_ID               0xF0
 222 #define LOWPAN_NHC_UDP_CHECKSUMC        0x04
 223 #define LOWPAN_NHC_UDP_CHECKSUMI        0x00
 224
 225 #define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
 226 #define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
 227 #define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
 228 #define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00
 229
 230 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
 231 #define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
 232 #define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
 233                                         dest = 0xF0 + 8 bit inline */
 234 #define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
 235                                         dest = 16 bit inline */
 236 #define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
 237 #define LOWPAN_NHC_UDP_CS_C     0x04 /* checksum elided */
 238
 239 #ifdef DEBUG
 240 /* print data in line */
 241 static inline void raw_dump_inline(const char *caller, char *msg,
 242                                    unsigned char *buf, int len)
 243 {
 244         if (msg)
 245                 pr_debug("%s():%s: ", caller, msg);
 246
 247         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 248 }
 249
 250 /* print data in a table format:
 251  *
 252  * addr: xx xx xx xx xx xx
 253  * addr: xx xx xx xx xx xx
 254  * ...
 255  */
 256 static inline void raw_dump_table(const char *caller, char *msg,
 257                                   unsigned char *buf, int len)
 258 {
 259         if (msg)
 260                 pr_debug("%s():%s:\n", caller, msg);
 261
 262         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 263 }
 264 #else
 265 static inline void raw_dump_table(const char *caller, char *msg,
 266                                   unsigned char *buf, int len) { }
 267 static inline void raw_dump_inline(const char *caller, char *msg,
 268                                    unsigned char *buf, int len) { }
 269 #endif
 270
 271 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
 272 {
 273         if (unlikely(!pskb_may_pull(skb, 1)))
 274                 return -EINVAL;
 275
 276         *val = skb->data[0];
 277         skb_pull(skb, 1);
 278
 279         return 0;
 280 }
 281
 282 static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
 283 {
 284         if (unlikely(!pskb_may_pull(skb, 2)))
 285                 return -EINVAL;
 286
 287         *val = (skb->data[0] << 8) | skb->data[1];
 288         skb_pull(skb, 2);
 289
 290         return 0;
 291 }
 292
 293 static inline bool lowpan_fetch_skb(struct sk_buff *skb,
 294                 void *data, const unsigned int len)
 295 {
 296         if (unlikely(!pskb_may_pull(skb, len)))
 297                 return true;
 298
 299         skb_copy_from_linear_data(skb, data, len);
 300         skb_pull(skb, len);
 301
 302         return false;
 303 }
 304
 305 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 306                                        const size_t len)
 307 {
 308         memcpy(*hc_ptr, data, len);
 309         *hc_ptr += len;
 310 }
 311
 312 static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
 313 {
 314         static const u8 addr_sizes[] = {
 315                 [LOWPAN_IPHC_ADDR_00] = 16,
 316                 [LOWPAN_IPHC_ADDR_01] = 8,
 317                 [LOWPAN_IPHC_ADDR_02] = 2,
 318                 [LOWPAN_IPHC_ADDR_03] = 0,
 319         };
 320         return addr_sizes[addr_mode];
 321 }
 322
 323 static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
 324 {
 325         u8 ret = 1;
 326
 327         if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
 328                 *uncomp_header += sizeof(struct udphdr);
 329
 330                 switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
 331                 case LOWPAN_NHC_UDP_CS_P_00:
 332                         ret += 4;
 333                         break;
 334                 case LOWPAN_NHC_UDP_CS_P_01:
 335                 case LOWPAN_NHC_UDP_CS_P_10:
 336                         ret += 3;
 337                         break;
 338                 case LOWPAN_NHC_UDP_CS_P_11:
 339                         ret++;
 340                         break;
 341                 default:
 342                         break;
 343                 }
 344
 345                 if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
 346                         ret += 2;
 347         }
 348
 349         return ret;
 350 }
 351
 352 /**
 353  *      lowpan_uncompress_size - returns skb->len size with uncompressed header
 354  *      @skb: sk_buff with 6lowpan header inside
 355  *      @datagram_offset: optional to get the datagram_offset value
 356  *
 357  *      Returns the skb->len with uncompressed header
 358  */
 359 static inline u16
 360 lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
 361 {
 362         u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
 363         u8 iphc0, iphc1, h_enc;
 364
 365         iphc0 = skb_network_header(skb)[0];
 366         iphc1 = skb_network_header(skb)[1];
 367
 368         switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
 369         case 0:
 370                 ret += 4;
 371                 break;
 372         case 1:
 373                 ret += 3;
 374                 break;
 375         case 2:
 376                 ret++;
 377                 break;
 378         default:
 379                 break;
 380         }
 381
 382         if (!(iphc0 & LOWPAN_IPHC_NH_C))
 383                 ret++;
 384
 385         if (!(iphc0 & 0x03))
 386                 ret++;
 387
 388         ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
 389                                      LOWPAN_IPHC_SAM_BIT);
 390
 391         if (iphc1 & LOWPAN_IPHC_M) {
 392                 switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
 393                         LOWPAN_IPHC_DAM_BIT) {
 394                 case LOWPAN_IPHC_DAM_00:
 395                         ret += 16;
 396                         break;
 397                 case LOWPAN_IPHC_DAM_01:
 398                         ret += 6;
 399                         break;
 400                 case LOWPAN_IPHC_DAM_10:
 401                         ret += 4;
 402                         break;
 403                 case LOWPAN_IPHC_DAM_11:
 404                         ret++;
 405                         break;
 406                 default:
 407                         break;
 408                 }
 409         } else {
 410                 ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
 411                                              LOWPAN_IPHC_DAM_BIT);
 412         }
 413
 414         if (iphc0 & LOWPAN_IPHC_NH_C) {
 415                 h_enc = skb_network_header(skb)[ret];
 416                 ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
 417         }
 418
 419         if (dgram_offset)
 420                 *dgram_offset = uncomp_header;
 421
 422         return skb->len + uncomp_header - ret;
 423 }
 424
 425 typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);
 426
 427 int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
 428                 const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
 429                 const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
 430                 u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
 431 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
 432                         unsigned short type, const void *_daddr,
 433                         const void *_saddr, unsigned int len);
 434
 435 #endif /* __6LOWPAN_H__ */