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
  79 #define LOWPAN_DISPATCH_IPV6            0x41 /* 01000001 = 65 */
  80 #define LOWPAN_DISPATCH_IPHC            0x60 /* 011xxxxx = ... */
  81 #define LOWPAN_DISPATCH_IPHC_MASK       0xe0
  82
  83 static inline bool lowpan_is_ipv6(u8 dispatch)
  84 {
  85         return dispatch == LOWPAN_DISPATCH_IPV6;
  86 }
  87
  88 static inline bool lowpan_is_iphc(u8 dispatch)
  89 {
  90         return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
  91 }
  92
  93 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
  94         (sizeof(struct lowpan_priv) + llpriv_size)
  95
  96 enum lowpan_lltypes {
  97         LOWPAN_LLTYPE_BTLE,
  98         LOWPAN_LLTYPE_IEEE802154,
  99 };
 100
 101 struct lowpan_priv {
 102         enum lowpan_lltypes lltype;
 103         struct dentry *iface_debugfs;
 104
 105         /* must be last */
 106         u8 priv[0] __aligned(sizeof(void *));
 107 };
 108
 109 static inline
 110 struct lowpan_priv *lowpan_priv(const struct net_device *dev)
 111 {
 112         return netdev_priv(dev);
 113 }
 114
 115 struct lowpan_802154_cb {
 116         u16 d_tag;
 117         unsigned int d_size;
 118         u8 d_offset;
 119 };
 120
 121 static inline
 122 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
 123 {
 124         BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
 125         return (struct lowpan_802154_cb *)skb->cb;
 126 }
 127
 128 #ifdef DEBUG
 129 /* print data in line */
 130 static inline void raw_dump_inline(const char *caller, char *msg,
 131                                    const unsigned char *buf, int len)
 132 {
 133         if (msg)
 134                 pr_debug("%s():%s: ", caller, msg);
 135
 136         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 137 }
 138
 139 /* print data in a table format:
 140  *
 141  * addr: xx xx xx xx xx xx
 142  * addr: xx xx xx xx xx xx
 143  * ...
 144  */
 145 static inline void raw_dump_table(const char *caller, char *msg,
 146                                   const unsigned char *buf, int len)
 147 {
 148         if (msg)
 149                 pr_debug("%s():%s:\n", caller, msg);
 150
 151         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 152 }
 153 #else
 154 static inline void raw_dump_table(const char *caller, char *msg,
 155                                   const unsigned char *buf, int len) { }
 156 static inline void raw_dump_inline(const char *caller, char *msg,
 157                                    const unsigned char *buf, int len) { }
 158 #endif
 159
 160 /**
 161  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
 162  *
 163  * This function will pull data from sk buffer and put it into data to
 164  * remove the 6LoWPAN inline data. This function returns true if the
 165  * sk buffer is too small to pull the amount of data which is specified
 166  * by len.
 167  *
 168  * @skb: the buffer where the inline data should be pulled from.
 169  * @data: destination buffer for the inline data.
 170  * @len: amount of data which should be pulled in bytes.
 171  */
 172 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
 173                                     unsigned int len)
 174 {
 175         if (unlikely(!pskb_may_pull(skb, len)))
 176                 return true;
 177
 178         skb_copy_from_linear_data(skb, data, len);
 179         skb_pull(skb, len);
 180
 181         return false;
 182 }
 183
 184 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 185                                        const size_t len)
 186 {
 187         memcpy(*hc_ptr, data, len);
 188         *hc_ptr += len;
 189 }
 190
 191 int lowpan_register_netdevice(struct net_device *dev,
 192                               enum lowpan_lltypes lltype);
 193 int lowpan_register_netdev(struct net_device *dev,
 194                            enum lowpan_lltypes lltype);
 195 void lowpan_unregister_netdevice(struct net_device *dev);
 196 void lowpan_unregister_netdev(struct net_device *dev);
 197
 198 /**
 199  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
 200  *
 201  * This function replaces the IPHC 6LoWPAN header which should be pointed at
 202  * skb->data and skb_network_header, with the IPv6 header.
 203  * It would be nice that the caller have the necessary headroom of IPv6 header
 204  * and greatest Transport layer header, this would reduce the overhead for
 205  * reallocate headroom.
 206  *
 207  * @skb: the buffer which should be manipulate.
 208  * @dev: the lowpan net device pointer.
 209  * @daddr: destination lladdr of mac header which is used for compression
 210  *      methods.
 211  * @saddr: source lladdr of mac header which is used for compression
 212  *      methods.
 213  */
 214 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
 215                              const void *daddr, const void *saddr);
 216
 217 /**
 218  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
 219  *
 220  * This function replaces the IPv6 header which should be pointed at
 221  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
 222  * The caller need to be sure that the sk buffer is not shared and at have
 223  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
 224  * which is the IPHC "more bytes than IPv6 header" at worst case.
 225  *
 226  * @skb: the buffer which should be manipulate.
 227  * @dev: the lowpan net device pointer.
 228  * @daddr: destination lladdr of mac header which is used for compression
 229  *      methods.
 230  * @saddr: source lladdr of mac header which is used for compression
 231  *      methods.
 232  */
 233 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
 234                            const void *daddr, const void *saddr);
 235
 236 #endif /* __6LOWPAN_H__ */