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 /* special link-layer handling */
  62 #include <net/mac802154.h>
  63
  64 #define EUI64_ADDR_LEN          8
  65
  66 #define LOWPAN_NHC_MAX_ID_LEN   1
  67 /* Maximum next header compression length which we currently support inclusive
  68  * possible inline data.
  69  */
  70 #define LOWPAN_NHC_MAX_HDR_LEN  (sizeof(struct udphdr))
  71 /* Max IPHC Header len without IPv6 hdr specific inline data.
  72  * Useful for getting the "extra" bytes we need at worst case compression.
  73  *
  74  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
  75  */
  76 #define LOWPAN_IPHC_MAX_HEADER_LEN      (2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
  77 /* Maximum worst case IPHC header buffer size */
  78 #define LOWPAN_IPHC_MAX_HC_BUF_LEN      (sizeof(struct ipv6hdr) +       \
  79                                          LOWPAN_IPHC_MAX_HEADER_LEN +   \
  80                                          LOWPAN_NHC_MAX_HDR_LEN)
  81 /* SCI/DCI is 4 bit width, so we have maximum 16 entries */
  82 #define LOWPAN_IPHC_CTX_TABLE_SIZE      (1 << 4)
  83
  84 #define LOWPAN_DISPATCH_IPV6            0x41 /* 01000001 = 65 */
  85 #define LOWPAN_DISPATCH_IPHC            0x60 /* 011xxxxx = ... */
  86 #define LOWPAN_DISPATCH_IPHC_MASK       0xe0
  87
  88 static inline bool lowpan_is_ipv6(u8 dispatch)
  89 {
  90         return dispatch == LOWPAN_DISPATCH_IPV6;
  91 }
  92
  93 static inline bool lowpan_is_iphc(u8 dispatch)
  94 {
  95         return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
  96 }
  97
  98 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
  99         (sizeof(struct lowpan_dev) + llpriv_size)
 100
 101 enum lowpan_lltypes {
 102         LOWPAN_LLTYPE_BTLE,
 103         LOWPAN_LLTYPE_IEEE802154,
 104 };
 105
 106 enum lowpan_iphc_ctx_flags {
 107         LOWPAN_IPHC_CTX_FLAG_ACTIVE,
 108         LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
 109 };
 110
 111 struct lowpan_iphc_ctx {
 112         u8 id;
 113         struct in6_addr pfx;
 114         u8 plen;
 115         unsigned long flags;
 116 };
 117
 118 struct lowpan_iphc_ctx_table {
 119         spinlock_t lock;
 120         const struct lowpan_iphc_ctx_ops *ops;
 121         struct lowpan_iphc_ctx table[LOWPAN_IPHC_CTX_TABLE_SIZE];
 122 };
 123
 124 static inline bool lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx *ctx)
 125 {
 126         return test_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
 127 }
 128
 129 static inline bool
 130 lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
 131 {
 132         return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
 133 }
 134
 135 struct lowpan_dev {
 136         enum lowpan_lltypes lltype;
 137         struct dentry *iface_debugfs;
 138         struct lowpan_iphc_ctx_table ctx;
 139
 140         /* must be last */
 141         u8 priv[0] __aligned(sizeof(void *));
 142 };
 143
 144 static inline
 145 struct lowpan_dev *lowpan_dev(const struct net_device *dev)
 146 {
 147         return netdev_priv(dev);
 148 }
 149
 150 /* private device info */
 151 struct lowpan_802154_dev {
 152         struct net_device       *wdev; /* wpan device ptr */
 153         u16                     fragment_tag;
 154 };
 155
 156 static inline struct
 157 lowpan_802154_dev *lowpan_802154_dev(const struct net_device *dev)
 158 {
 159         return (struct lowpan_802154_dev *)lowpan_dev(dev)->priv;
 160 }
 161
 162 struct lowpan_802154_cb {
 163         u16 d_tag;
 164         unsigned int d_size;
 165         u8 d_offset;
 166 };
 167
 168 static inline
 169 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
 170 {
 171         BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
 172         return (struct lowpan_802154_cb *)skb->cb;
 173 }
 174
 175 static inline void lowpan_iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
 176                                                        const void *lladdr)
 177 {
 178         /* fe:80::XXXX:XXXX:XXXX:XXXX
 179          *        \_________________/
 180          *              hwaddr
 181          */
 182         ipaddr->s6_addr[0] = 0xFE;
 183         ipaddr->s6_addr[1] = 0x80;
 184         memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
 185         /* second bit-flip (Universe/Local)
 186          * is done according RFC2464
 187          */
 188         ipaddr->s6_addr[8] ^= 0x02;
 189 }
 190
 191 #ifdef DEBUG
 192 /* print data in line */
 193 static inline void raw_dump_inline(const char *caller, char *msg,
 194                                    const unsigned char *buf, int len)
 195 {
 196         if (msg)
 197                 pr_debug("%s():%s: ", caller, msg);
 198
 199         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
 200 }
 201
 202 /* print data in a table format:
 203  *
 204  * addr: xx xx xx xx xx xx
 205  * addr: xx xx xx xx xx xx
 206  * ...
 207  */
 208 static inline void raw_dump_table(const char *caller, char *msg,
 209                                   const unsigned char *buf, int len)
 210 {
 211         if (msg)
 212                 pr_debug("%s():%s:\n", caller, msg);
 213
 214         print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
 215 }
 216 #else
 217 static inline void raw_dump_table(const char *caller, char *msg,
 218                                   const unsigned char *buf, int len) { }
 219 static inline void raw_dump_inline(const char *caller, char *msg,
 220                                    const unsigned char *buf, int len) { }
 221 #endif
 222
 223 /**
 224  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
 225  *
 226  * This function will pull data from sk buffer and put it into data to
 227  * remove the 6LoWPAN inline data. This function returns true if the
 228  * sk buffer is too small to pull the amount of data which is specified
 229  * by len.
 230  *
 231  * @skb: the buffer where the inline data should be pulled from.
 232  * @data: destination buffer for the inline data.
 233  * @len: amount of data which should be pulled in bytes.
 234  */
 235 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
 236                                     unsigned int len)
 237 {
 238         if (unlikely(!pskb_may_pull(skb, len)))
 239                 return true;
 240
 241         skb_copy_from_linear_data(skb, data, len);
 242         skb_pull(skb, len);
 243
 244         return false;
 245 }
 246
 247 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 248                                        const size_t len)
 249 {
 250         memcpy(*hc_ptr, data, len);
 251         *hc_ptr += len;
 252 }
 253
 254 int lowpan_register_netdevice(struct net_device *dev,
 255                               enum lowpan_lltypes lltype);
 256 int lowpan_register_netdev(struct net_device *dev,
 257                            enum lowpan_lltypes lltype);
 258 void lowpan_unregister_netdevice(struct net_device *dev);
 259 void lowpan_unregister_netdev(struct net_device *dev);
 260
 261 /**
 262  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
 263  *
 264  * This function replaces the IPHC 6LoWPAN header which should be pointed at
 265  * skb->data and skb_network_header, with the IPv6 header.
 266  * It would be nice that the caller have the necessary headroom of IPv6 header
 267  * and greatest Transport layer header, this would reduce the overhead for
 268  * reallocate headroom.
 269  *
 270  * @skb: the buffer which should be manipulate.
 271  * @dev: the lowpan net device pointer.
 272  * @daddr: destination lladdr of mac header which is used for compression
 273  *      methods.
 274  * @saddr: source lladdr of mac header which is used for compression
 275  *      methods.
 276  */
 277 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
 278                              const void *daddr, const void *saddr);
 279
 280 /**
 281  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
 282  *
 283  * This function replaces the IPv6 header which should be pointed at
 284  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
 285  * The caller need to be sure that the sk buffer is not shared and at have
 286  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
 287  * which is the IPHC "more bytes than IPv6 header" at worst case.
 288  *
 289  * @skb: the buffer which should be manipulate.
 290  * @dev: the lowpan net device pointer.
 291  * @daddr: destination lladdr of mac header which is used for compression
 292  *      methods.
 293  * @saddr: source lladdr of mac header which is used for compression
 294  *      methods.
 295  */
 296 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
 297                            const void *daddr, const void *saddr);
 298
 299 #endif /* __6LOWPAN_H__ */