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 EUI64_ADDR_LEN          8
  60
  61 #define LOWPAN_NHC_MAX_ID_LEN   1
  62 /* Maximum next header compression length which we currently support inclusive
  63  * possible inline data.
  64  */
  65 #define LOWPAN_NHC_MAX_HDR_LEN  (sizeof(struct udphdr))
  66 /* Max IPHC Header len without IPv6 hdr specific inline data.
  67  * Useful for getting the "extra" bytes we need at worst case compression.
  68  *
  69  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
  70  */
  71 #define LOWPAN_IPHC_MAX_HEADER_LEN      (2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
  72 /* Maximum worst case IPHC header buffer size */
  73 #define LOWPAN_IPHC_MAX_HC_BUF_LEN      (sizeof(struct ipv6hdr) +       \
  74                                          LOWPAN_IPHC_MAX_HEADER_LEN +   \
  75                                          LOWPAN_NHC_MAX_HDR_LEN)
  76
  77 #define LOWPAN_DISPATCH_IPV6            0x41 /* 01000001 = 65 */
  78 #define LOWPAN_DISPATCH_IPHC            0x60 /* 011xxxxx = ... */
  79 #define LOWPAN_DISPATCH_IPHC_MASK       0xe0
  80
  81 static inline bool lowpan_is_ipv6(u8 dispatch)
  82 {
  83         return dispatch == LOWPAN_DISPATCH_IPV6;
  84 }
  85
  86 static inline bool lowpan_is_iphc(u8 dispatch)
  87 {
  88         return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
  89 }
  90
  91 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
  92         (sizeof(struct lowpan_priv) + llpriv_size)
  93
  94 enum lowpan_lltypes {
  95         LOWPAN_LLTYPE_BTLE,
  96         LOWPAN_LLTYPE_IEEE802154,
  97 };
  98
  99 struct lowpan_priv {
 100         enum lowpan_lltypes lltype;
 101
 102         /* must be last */
 103         u8 priv[0] __aligned(sizeof(void *));
 104 };
 105
 106 static inline
 107 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 108 {
 109         return netdev_priv(dev);
 110 }
 111
 112 struct lowpan_802154_cb {
 113         u16 d_tag;
 114         unsigned int d_size;
 115         u8 d_offset;
 116 };
 117
 118 static inline
 119 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
 120 {
 121         BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
 122         return (struct lowpan_802154_cb *)skb->cb;
 123 }
 124
 125 #ifdef DEBUG
 126 /* print data in line */
 127 static inline void raw_dump_inline(const char *caller, char *msg,
 128                                    const unsigned char *buf, int len)
 129 {
 130         if (msg)
 131                 pr_debug("%s():%s: ", caller, msg);
 132
 133         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 134 }
 135
 136 /* print data in a table format:
 137  *
 138  * addr: xx xx xx xx xx xx
 139  * addr: xx xx xx xx xx xx
 140  * ...
 141  */
 142 static inline void raw_dump_table(const char *caller, char *msg,
 143                                   const unsigned char *buf, int len)
 144 {
 145         if (msg)
 146                 pr_debug("%s():%s:\n", caller, msg);
 147
 148         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 149 }
 150 #else
 151 static inline void raw_dump_table(const char *caller, char *msg,
 152                                   const unsigned char *buf, int len) { }
 153 static inline void raw_dump_inline(const char *caller, char *msg,
 154                                    const unsigned char *buf, int len) { }
 155 #endif
 156
 157 /**
 158  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
 159  *
 160  * This function will pull data from sk buffer and put it into data to
 161  * remove the 6LoWPAN inline data. This function returns true if the
 162  * sk buffer is too small to pull the amount of data which is specified
 163  * by len.
 164  *
 165  * @skb: the buffer where the inline data should be pulled from.
 166  * @data: destination buffer for the inline data.
 167  * @len: amount of data which should be pulled in bytes.
 168  */
 169 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
 170                                     unsigned int len)
 171 {
 172         if (unlikely(!pskb_may_pull(skb, len)))
 173                 return true;
 174
 175         skb_copy_from_linear_data(skb, data, len);
 176         skb_pull(skb, len);
 177
 178         return false;
 179 }
 180
 181 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 182                                        const size_t len)
 183 {
 184         memcpy(*hc_ptr, data, len);
 185         *hc_ptr += len;
 186 }
 187
 188 void lowpan_netdev_setup(struct net_device *dev, enum lowpan_lltypes lltype);
 189
 190 /**
 191  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
 192  *
 193  * This function replaces the IPHC 6LoWPAN header which should be pointed at
 194  * skb->data and skb_network_header, with the IPv6 header.
 195  * It would be nice that the caller have the necessary headroom of IPv6 header
 196  * and greatest Transport layer header, this would reduce the overhead for
 197  * reallocate headroom.
 198  *
 199  * @skb: the buffer which should be manipulate.
 200  * @dev: the lowpan net device pointer.
 201  * @daddr: destination lladdr of mac header which is used for compression
 202  *      methods.
 203  * @saddr: source lladdr of mac header which is used for compression
 204  *      methods.
 205  */
 206 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
 207                              const void *daddr, const void *saddr);
 208
 209 /**
 210  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
 211  *
 212  * This function replaces the IPv6 header which should be pointed at
 213  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
 214  * The caller need to be sure that the sk buffer is not shared and at have
 215  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
 216  * which is the IPHC "more bytes than IPv6 header" at worst case.
 217  *
 218  * @skb: the buffer which should be manipulate.
 219  * @dev: the lowpan net device pointer.
 220  * @daddr: destination lladdr of mac header which is used for compression
 221  *      methods.
 222  * @saddr: source lladdr of mac header which is used for compression
 223  *      methods.
 224  */
 225 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
 226                            const void *daddr, const void *saddr);
 227
 228 #endif /* __6LOWPAN_H__ */