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 <linux/debugfs.h>
  57
  58 #include <net/ipv6.h>
  59 #include <net/net_namespace.h>
  60
  61 #define EUI64_ADDR_LEN          8
  62
  63 #define LOWPAN_NHC_MAX_ID_LEN   1
  64 /* Maximum next header compression length which we currently support inclusive
  65  * possible inline data.
  66  */
  67 #define LOWPAN_NHC_MAX_HDR_LEN  (sizeof(struct udphdr))
  68 /* Max IPHC Header len without IPv6 hdr specific inline data.
  69  * Useful for getting the "extra" bytes we need at worst case compression.
  70  *
  71  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
  72  */
  73 #define LOWPAN_IPHC_MAX_HEADER_LEN      (2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
  74 /* Maximum worst case IPHC header buffer size */
  75 #define LOWPAN_IPHC_MAX_HC_BUF_LEN      (sizeof(struct ipv6hdr) +       \
  76                                          LOWPAN_IPHC_MAX_HEADER_LEN +   \
  77                                          LOWPAN_NHC_MAX_HDR_LEN)
  78 /* SCI/DCI is 4 bit width, so we have maximum 16 entries */
  79 #define LOWPAN_IPHC_CTX_TABLE_SIZE      (1 << 4)
  80
  81 #define LOWPAN_DISPATCH_IPV6            0x41 /* 01000001 = 65 */
  82 #define LOWPAN_DISPATCH_IPHC            0x60 /* 011xxxxx = ... */
  83 #define LOWPAN_DISPATCH_IPHC_MASK       0xe0
  84
  85 static inline bool lowpan_is_ipv6(u8 dispatch)
  86 {
  87         return dispatch == LOWPAN_DISPATCH_IPV6;
  88 }
  89
  90 static inline bool lowpan_is_iphc(u8 dispatch)
  91 {
  92         return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
  93 }
  94
  95 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
  96         (sizeof(struct lowpan_priv) + llpriv_size)
  97
  98 enum lowpan_lltypes {
  99         LOWPAN_LLTYPE_BTLE,
 100         LOWPAN_LLTYPE_IEEE802154,
 101 };
 102
 103 enum lowpan_iphc_ctx_flags {
 104         LOWPAN_IPHC_CTX_FLAG_ACTIVE,
 105         LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
 106 };
 107
 108 struct lowpan_iphc_ctx {
 109         u8 id;
 110         struct in6_addr pfx;
 111         u8 plen;
 112         unsigned long flags;
 113 };
 114
 115 struct lowpan_iphc_ctx_table {
 116         spinlock_t lock;
 117         const struct lowpan_iphc_ctx_ops *ops;
 118         struct lowpan_iphc_ctx table[LOWPAN_IPHC_CTX_TABLE_SIZE];
 119 };
 120
 121 static inline bool lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx *ctx)
 122 {
 123         return test_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
 124 }
 125
 126 static inline bool
 127 lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
 128 {
 129         return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
 130 }
 131
 132 struct lowpan_priv {
 133         enum lowpan_lltypes lltype;
 134         struct dentry *iface_debugfs;
 135         struct lowpan_iphc_ctx_table ctx;
 136
 137         /* must be last */
 138         u8 priv[0] __aligned(sizeof(void *));
 139 };
 140
 141 static inline
 142 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 143 {
 144         return netdev_priv(dev);
 145 }
 146
 147 struct lowpan_802154_cb {
 148         u16 d_tag;
 149         unsigned int d_size;
 150         u8 d_offset;
 151 };
 152
 153 static inline
 154 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
 155 {
 156         BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
 157         return (struct lowpan_802154_cb *)skb->cb;
 158 }
 159
 160 #ifdef DEBUG
 161 /* print data in line */
 162 static inline void raw_dump_inline(const char *caller, char *msg,
 163                                    const unsigned char *buf, int len)
 164 {
 165         if (msg)
 166                 pr_debug("%s():%s: ", caller, msg);
 167
 168         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 169 }
 170
 171 /* print data in a table format:
 172  *
 173  * addr: xx xx xx xx xx xx
 174  * addr: xx xx xx xx xx xx
 175  * ...
 176  */
 177 static inline void raw_dump_table(const char *caller, char *msg,
 178                                   const unsigned char *buf, int len)
 179 {
 180         if (msg)
 181                 pr_debug("%s():%s:\n", caller, msg);
 182
 183         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 184 }
 185 #else
 186 static inline void raw_dump_table(const char *caller, char *msg,
 187                                   const unsigned char *buf, int len) { }
 188 static inline void raw_dump_inline(const char *caller, char *msg,
 189                                    const unsigned char *buf, int len) { }
 190 #endif
 191
 192 /**
 193  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
 194  *
 195  * This function will pull data from sk buffer and put it into data to
 196  * remove the 6LoWPAN inline data. This function returns true if the
 197  * sk buffer is too small to pull the amount of data which is specified
 198  * by len.
 199  *
 200  * @skb: the buffer where the inline data should be pulled from.
 201  * @data: destination buffer for the inline data.
 202  * @len: amount of data which should be pulled in bytes.
 203  */
 204 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
 205                                     unsigned int len)
 206 {
 207         if (unlikely(!pskb_may_pull(skb, len)))
 208                 return true;
 209
 210         skb_copy_from_linear_data(skb, data, len);
 211         skb_pull(skb, len);
 212
 213         return false;
 214 }
 215
 216 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 217                                        const size_t len)
 218 {
 219         memcpy(*hc_ptr, data, len);
 220         *hc_ptr += len;
 221 }
 222
 223 int lowpan_register_netdevice(struct net_device *dev,
 224                               enum lowpan_lltypes lltype);
 225 int lowpan_register_netdev(struct net_device *dev,
 226                            enum lowpan_lltypes lltype);
 227 void lowpan_unregister_netdevice(struct net_device *dev);
 228 void lowpan_unregister_netdev(struct net_device *dev);
 229
 230 /**
 231  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
 232  *
 233  * This function replaces the IPHC 6LoWPAN header which should be pointed at
 234  * skb->data and skb_network_header, with the IPv6 header.
 235  * It would be nice that the caller have the necessary headroom of IPv6 header
 236  * and greatest Transport layer header, this would reduce the overhead for
 237  * reallocate headroom.
 238  *
 239  * @skb: the buffer which should be manipulate.
 240  * @dev: the lowpan net device pointer.
 241  * @daddr: destination lladdr of mac header which is used for compression
 242  *      methods.
 243  * @saddr: source lladdr of mac header which is used for compression
 244  *      methods.
 245  */
 246 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
 247                              const void *daddr, const void *saddr);
 248
 249 /**
 250  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
 251  *
 252  * This function replaces the IPv6 header which should be pointed at
 253  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
 254  * The caller need to be sure that the sk buffer is not shared and at have
 255  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
 256  * which is the IPHC "more bytes than IPv6 header" at worst case.
 257  *
 258  * @skb: the buffer which should be manipulate.
 259  * @dev: the lowpan net device pointer.
 260  * @daddr: destination lladdr of mac header which is used for compression
 261  *      methods.
 262  * @saddr: source lladdr of mac header which is used for compression
 263  *      methods.
 264  */
 265 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
 266                            const void *daddr, const void *saddr);
 267
 268 #endif /* __6LOWPAN_H__ */