include/net/6lowpan.h

0001 /*
0002  * Copyright 2011, Siemens AG
0003  * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
0004  */
0005
0006 /*
0007  * Based on patches from Jon Smirl <jonsmirl@gmail.com>
0008  * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
0009  *
0010  * This program is free software; you can redistribute it and/or modify
0011  * it under the terms of the GNU General Public License version 2
0012  * as published by the Free Software Foundation.
0013  *
0014  * This program is distributed in the hope that it will be useful,
0015  * but WITHOUT ANY WARRANTY; without even the implied warranty of
0016  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
0017  * GNU General Public License for more details.
0018  *
0019  * You should have received a copy of the GNU General Public License along
0020  * with this program; if not, write to the Free Software Foundation, Inc.,
0021  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
0022  */
0023
0024 /* Jon's code is based on 6lowpan implementation for Contiki which is:
0025  * Copyright (c) 2008, Swedish Institute of Computer Science.
0026  * All rights reserved.
0027  *
0028  * Redistribution and use in source and binary forms, with or without
0029  * modification, are permitted provided that the following conditions
0030  * are met:
0031  * 1. Redistributions of source code must retain the above copyright
0032  *    notice, this list of conditions and the following disclaimer.
0033  * 2. Redistributions in binary form must reproduce the above copyright
0034  *    notice, this list of conditions and the following disclaimer in the
0035  *    documentation and/or other materials provided with the distribution.
0036  * 3. Neither the name of the Institute nor the names of its contributors
0037  *    may be used to endorse or promote products derived from this software
0038  *    without specific prior written permission.
0039  *
0040  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
0041  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0042  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0043  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
0044  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
0045  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
0046  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
0047  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
0048  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
0049  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
0050  * SUCH DAMAGE.
0051  */
0052
0053 #ifndef __6LOWPAN_H__
0054 #define __6LOWPAN_H__
0055
0056 #include <linux/debugfs.h>
0057
0058 #include <net/ipv6.h>
0059 #include <net/net_namespace.h>
0060
0061 /* special link-layer handling */
0062 #include <net/mac802154.h>
0063
0064 #define EUI64_ADDR_LEN      8
0065
0066 #define LOWPAN_NHC_MAX_ID_LEN   1
0067 /* Maximum next header compression length which we currently support inclusive
0068  * possible inline data.
0069  */
0070 #define LOWPAN_NHC_MAX_HDR_LEN  (sizeof(struct udphdr))
0071 /* Max IPHC Header len without IPv6 hdr specific inline data.
0072  * Useful for getting the "extra" bytes we need at worst case compression.
0073  *
0074  * LOWPAN_IPHC + CID + LOWPAN_NHC_MAX_ID_LEN
0075  */
0076 #define LOWPAN_IPHC_MAX_HEADER_LEN  (2 + 1 + LOWPAN_NHC_MAX_ID_LEN)
0077 /* Maximum worst case IPHC header buffer size */
0078 #define LOWPAN_IPHC_MAX_HC_BUF_LEN  (sizeof(struct ipv6hdr) +   \
0079                      LOWPAN_IPHC_MAX_HEADER_LEN +   \
0080                      LOWPAN_NHC_MAX_HDR_LEN)
0081 /* SCI/DCI is 4 bit width, so we have maximum 16 entries */
0082 #define LOWPAN_IPHC_CTX_TABLE_SIZE  (1 << 4)
0083
0084 #define LOWPAN_DISPATCH_IPV6        0x41 /* 01000001 = 65 */
0085 #define LOWPAN_DISPATCH_IPHC        0x60 /* 011xxxxx = ... */
0086 #define LOWPAN_DISPATCH_IPHC_MASK   0xe0
0087
0088 static inline bool lowpan_is_ipv6(u8 dispatch)
0089 {
0090     return dispatch == LOWPAN_DISPATCH_IPV6;
0091 }
0092
0093 static inline bool lowpan_is_iphc(u8 dispatch)
0094 {
0095     return (dispatch & LOWPAN_DISPATCH_IPHC_MASK) == LOWPAN_DISPATCH_IPHC;
0096 }
0097
0098 #define LOWPAN_PRIV_SIZE(llpriv_size)   \
0099     (sizeof(struct lowpan_dev) + llpriv_size)
0100
0101 enum lowpan_lltypes {
0102     LOWPAN_LLTYPE_BTLE,
0103     LOWPAN_LLTYPE_IEEE802154,
0104 };
0105
0106 enum lowpan_iphc_ctx_flags {
0107     LOWPAN_IPHC_CTX_FLAG_ACTIVE,
0108     LOWPAN_IPHC_CTX_FLAG_COMPRESSION,
0109 };
0110
0111 struct lowpan_iphc_ctx {
0112     u8 id;
0113     struct in6_addr pfx;
0114     u8 plen;
0115     unsigned long flags;
0116 };
0117
0118 struct lowpan_iphc_ctx_table {
0119     spinlock_t lock;
0120     const struct lowpan_iphc_ctx_ops *ops;
0121     struct lowpan_iphc_ctx table[LOWPAN_IPHC_CTX_TABLE_SIZE];
0122 };
0123
0124 static inline bool lowpan_iphc_ctx_is_active(const struct lowpan_iphc_ctx *ctx)
0125 {
0126     return test_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
0127 }
0128
0129 static inline bool
0130 lowpan_iphc_ctx_is_compression(const struct lowpan_iphc_ctx *ctx)
0131 {
0132     return test_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
0133 }
0134
0135 struct lowpan_dev {
0136     enum lowpan_lltypes lltype;
0137     struct dentry *iface_debugfs;
0138     struct lowpan_iphc_ctx_table ctx;
0139
0140     /* must be last */
0141     u8 priv[] __aligned(sizeof(void *));
0142 };
0143
0144 struct lowpan_802154_neigh {
0145     __le16 short_addr;
0146 };
0147
0148 static inline
0149 struct lowpan_802154_neigh *lowpan_802154_neigh(void *neigh_priv)
0150 {
0151     return neigh_priv;
0152 }
0153
0154 static inline
0155 struct lowpan_dev *lowpan_dev(const struct net_device *dev)
0156 {
0157     return netdev_priv(dev);
0158 }
0159
0160 /* private device info */
0161 struct lowpan_802154_dev {
0162     struct net_device   *wdev; /* wpan device ptr */
0163     u16         fragment_tag;
0164 };
0165
0166 static inline struct
0167 lowpan_802154_dev *lowpan_802154_dev(const struct net_device *dev)
0168 {
0169     return (struct lowpan_802154_dev *)lowpan_dev(dev)->priv;
0170 }
0171
0172 struct lowpan_802154_cb {
0173     u16 d_tag;
0174     unsigned int d_size;
0175     u8 d_offset;
0176 };
0177
0178 static inline
0179 struct lowpan_802154_cb *lowpan_802154_cb(const struct sk_buff *skb)
0180 {
0181     BUILD_BUG_ON(sizeof(struct lowpan_802154_cb) > sizeof(skb->cb));
0182     return (struct lowpan_802154_cb *)skb->cb;
0183 }
0184
0185 static inline void lowpan_iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
0186                                const void *lladdr)
0187 {
0188     /* fe:80::XXXX:XXXX:XXXX:XXXX
0189      *        \_________________/
0190      *              hwaddr
0191      */
0192     ipaddr->s6_addr[0] = 0xFE;
0193     ipaddr->s6_addr[1] = 0x80;
0194     memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
0195     /* second bit-flip (Universe/Local)
0196      * is done according RFC2464
0197      */
0198     ipaddr->s6_addr[8] ^= 0x02;
0199 }
0200
0201 static inline void lowpan_iphc_uncompress_eui48_lladdr(struct in6_addr *ipaddr,
0202                                const void *lladdr)
0203 {
0204     /* fe:80::XXXX:XXff:feXX:XXXX
0205      *        \_________________/
0206      *              hwaddr
0207      */
0208     ipaddr->s6_addr[0] = 0xFE;
0209     ipaddr->s6_addr[1] = 0x80;
0210     memcpy(&ipaddr->s6_addr[8], lladdr, 3);
0211     ipaddr->s6_addr[11] = 0xFF;
0212     ipaddr->s6_addr[12] = 0xFE;
0213     memcpy(&ipaddr->s6_addr[13], lladdr + 3, 3);
0214 }
0215
0216 #ifdef DEBUG
0217 /* print data in line */
0218 static inline void raw_dump_inline(const char *caller, char *msg,
0219                    const unsigned char *buf, int len)
0220 {
0221     if (msg)
0222         pr_debug("%s():%s: ", caller, msg);
0223
0224     print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
0225 }
0226
0227 /* print data in a table format:
0228  *
0229  * addr: xx xx xx xx xx xx
0230  * addr: xx xx xx xx xx xx
0231  * ...
0232  */
0233 static inline void raw_dump_table(const char *caller, char *msg,
0234                   const unsigned char *buf, int len)
0235 {
0236     if (msg)
0237         pr_debug("%s():%s:\n", caller, msg);
0238
0239     print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
0240 }
0241 #else
0242 static inline void raw_dump_table(const char *caller, char *msg,
0243                   const unsigned char *buf, int len) { }
0244 static inline void raw_dump_inline(const char *caller, char *msg,
0245                    const unsigned char *buf, int len) { }
0246 #endif
0247
0248 /**
0249  * lowpan_fetch_skb - getting inline data from 6LoWPAN header
0250  *
0251  * This function will pull data from sk buffer and put it into data to
0252  * remove the 6LoWPAN inline data. This function returns true if the
0253  * sk buffer is too small to pull the amount of data which is specified
0254  * by len.
0255  *
0256  * @skb: the buffer where the inline data should be pulled from.
0257  * @data: destination buffer for the inline data.
0258  * @len: amount of data which should be pulled in bytes.
0259  */
0260 static inline bool lowpan_fetch_skb(struct sk_buff *skb, void *data,
0261                     unsigned int len)
0262 {
0263     if (unlikely(!pskb_may_pull(skb, len)))
0264         return true;
0265
0266     skb_copy_from_linear_data(skb, data, len);
0267     skb_pull(skb, len);
0268
0269     return false;
0270 }
0271
0272 static inline bool lowpan_802154_is_valid_src_short_addr(__le16 addr)
0273 {
0274     /* First bit of addr is multicast, reserved or 802.15.4 specific */
0275     return !(addr & cpu_to_le16(0x8000));
0276 }
0277
0278 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
0279                        const size_t len)
0280 {
0281     memcpy(*hc_ptr, data, len);
0282     *hc_ptr += len;
0283 }
0284
0285 int lowpan_register_netdevice(struct net_device *dev,
0286                   enum lowpan_lltypes lltype);
0287 int lowpan_register_netdev(struct net_device *dev,
0288                enum lowpan_lltypes lltype);
0289 void lowpan_unregister_netdevice(struct net_device *dev);
0290 void lowpan_unregister_netdev(struct net_device *dev);
0291
0292 /**
0293  * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
0294  *
0295  * This function replaces the IPHC 6LoWPAN header which should be pointed at
0296  * skb->data and skb_network_header, with the IPv6 header.
0297  * It would be nice that the caller have the necessary headroom of IPv6 header
0298  * and greatest Transport layer header, this would reduce the overhead for
0299  * reallocate headroom.
0300  *
0301  * @skb: the buffer which should be manipulate.
0302  * @dev: the lowpan net device pointer.
0303  * @daddr: destination lladdr of mac header which is used for compression
0304  *  methods.
0305  * @saddr: source lladdr of mac header which is used for compression
0306  *  methods.
0307  */
0308 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
0309                  const void *daddr, const void *saddr);
0310
0311 /**
0312  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header
0313  *
0314  * This function replaces the IPv6 header which should be pointed at
0315  * skb->data and skb_network_header, with the IPHC 6LoWPAN header.
0316  * The caller need to be sure that the sk buffer is not shared and at have
0317  * at least a headroom which is smaller or equal LOWPAN_IPHC_MAX_HEADER_LEN,
0318  * which is the IPHC "more bytes than IPv6 header" at worst case.
0319  *
0320  * @skb: the buffer which should be manipulate.
0321  * @dev: the lowpan net device pointer.
0322  * @daddr: destination lladdr of mac header which is used for compression
0323  *  methods.
0324  * @saddr: source lladdr of mac header which is used for compression
0325  *  methods.
0326  */
0327 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
0328                const void *daddr, const void *saddr);
0329
0330 #endif /* __6LOWPAN_H__ */