include/net/6lowpan.h

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
raw_dump_inline
raw_dump_table
raw_dump_table
raw_dump_inline
lowpan_fetch_skb_u8
lowpan_fetch_skb
lowpan_push_hc_data
lowpan_addr_mode_size
lowpan_next_hdr_size
lowpan_uncompress_size
/*
 * Copyright 2011, Siemens AG
 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
 */

/*
 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* Jon's code is based on 6lowpan implementation for Contiki which is:
 * Copyright (c) 2008, Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef __6LOWPAN_H__
#define __6LOWPAN_H__

#include <net/ipv6.h>
#include <net/net_namespace.h>

#define UIP_802154_SHORTADDR_LEN        2  /* compressed ipv6 address length */
#define UIP_IPH_LEN                     40 /* ipv6 fixed header size */
#define UIP_PROTO_UDP                   17 /* ipv6 next header value for UDP */
#define UIP_FRAGH_LEN                   8  /* ipv6 fragment header size */

/*
 * ipv6 address based on mac
 * second bit-flip (Universe/Local) is done according RFC2464
 */
#define is_addr_mac_addr_based(a, m) \
        ((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&   \
         (((a)->s6_addr[9])  == (m)[1]) &&              \
         (((a)->s6_addr[10]) == (m)[2]) &&              \
         (((a)->s6_addr[11]) == (m)[3]) &&              \
         (((a)->s6_addr[12]) == (m)[4]) &&              \
         (((a)->s6_addr[13]) == (m)[5]) &&              \
         (((a)->s6_addr[14]) == (m)[6]) &&              \
         (((a)->s6_addr[15]) == (m)[7]))

/*
 * check whether we can compress the IID to 16 bits,
 * it's possible for unicast adresses with first 49 bits are zero only.
 */
#define lowpan_is_iid_16_bit_compressable(a)    \
        ((((a)->s6_addr16[4]) == 0) &&          \
         (((a)->s6_addr[10]) == 0) &&           \
         (((a)->s6_addr[11]) == 0xff) &&        \
         (((a)->s6_addr[12]) == 0xfe) &&        \
         (((a)->s6_addr[13]) == 0))

/* check whether the 112-bit gid of the multicast address is mappable to: */

/* 48 bits, FFXX::00XX:XXXX:XXXX */
#define lowpan_is_mcast_addr_compressable48(a)  \
        ((((a)->s6_addr16[1]) == 0) &&          \
         (((a)->s6_addr16[2]) == 0) &&          \
         (((a)->s6_addr16[3]) == 0) &&          \
         (((a)->s6_addr16[4]) == 0) &&          \
         (((a)->s6_addr[10]) == 0))

/* 32 bits, FFXX::00XX:XXXX */
#define lowpan_is_mcast_addr_compressable32(a)  \
        ((((a)->s6_addr16[1]) == 0) &&          \
         (((a)->s6_addr16[2]) == 0) &&          \
         (((a)->s6_addr16[3]) == 0) &&          \
         (((a)->s6_addr16[4]) == 0) &&          \
         (((a)->s6_addr16[5]) == 0) &&          \
         (((a)->s6_addr[12]) == 0))

/* 8 bits, FF02::00XX */
#define lowpan_is_mcast_addr_compressable8(a)   \
        ((((a)->s6_addr[1])  == 2) &&           \
         (((a)->s6_addr16[1]) == 0) &&          \
         (((a)->s6_addr16[2]) == 0) &&          \
         (((a)->s6_addr16[3]) == 0) &&          \
         (((a)->s6_addr16[4]) == 0) &&          \
         (((a)->s6_addr16[5]) == 0) &&          \
         (((a)->s6_addr16[6]) == 0) &&          \
         (((a)->s6_addr[14]) == 0))

#define lowpan_is_addr_broadcast(a)     \
        ((((a)[0]) == 0xFF) &&  \
         (((a)[1]) == 0xFF) &&  \
         (((a)[2]) == 0xFF) &&  \
         (((a)[3]) == 0xFF) &&  \
         (((a)[4]) == 0xFF) &&  \
         (((a)[5]) == 0xFF) &&  \
         (((a)[6]) == 0xFF) &&  \
         (((a)[7]) == 0xFF))

#define LOWPAN_DISPATCH_IPV6    0x41 /* 01000001 = 65 */
#define LOWPAN_DISPATCH_HC1     0x42 /* 01000010 = 66 */
#define LOWPAN_DISPATCH_IPHC    0x60 /* 011xxxxx = ... */
#define LOWPAN_DISPATCH_FRAG1   0xc0 /* 11000xxx */
#define LOWPAN_DISPATCH_FRAGN   0xe0 /* 11100xxx */

#define LOWPAN_DISPATCH_MASK    0xf8 /* 11111000 */

#define LOWPAN_FRAG_TIMEOUT     (HZ * 60)       /* time-out 60 sec */

#define LOWPAN_FRAG1_HEAD_SIZE  0x4
#define LOWPAN_FRAGN_HEAD_SIZE  0x5

/*
 * Values of fields within the IPHC encoding first byte
 * (C stands for compressed and I for inline)
 */
#define LOWPAN_IPHC_TF          0x18

#define LOWPAN_IPHC_FL_C        0x10
#define LOWPAN_IPHC_TC_C        0x08
#define LOWPAN_IPHC_NH_C        0x04
#define LOWPAN_IPHC_TTL_1       0x01
#define LOWPAN_IPHC_TTL_64      0x02
#define LOWPAN_IPHC_TTL_255     0x03
#define LOWPAN_IPHC_TTL_I       0x00


/* Values of fields within the IPHC encoding second byte */
#define LOWPAN_IPHC_CID         0x80

#define LOWPAN_IPHC_ADDR_00     0x00
#define LOWPAN_IPHC_ADDR_01     0x01
#define LOWPAN_IPHC_ADDR_02     0x02
#define LOWPAN_IPHC_ADDR_03     0x03

#define LOWPAN_IPHC_SAC         0x40
#define LOWPAN_IPHC_SAM         0x30

#define LOWPAN_IPHC_SAM_BIT     4

#define LOWPAN_IPHC_M           0x08
#define LOWPAN_IPHC_DAC         0x04
#define LOWPAN_IPHC_DAM_00      0x00
#define LOWPAN_IPHC_DAM_01      0x01
#define LOWPAN_IPHC_DAM_10      0x02
#define LOWPAN_IPHC_DAM_11      0x03

#define LOWPAN_IPHC_DAM_BIT     0
/*
 * LOWPAN_UDP encoding (works together with IPHC)
 */
#define LOWPAN_NHC_UDP_MASK             0xF8
#define LOWPAN_NHC_UDP_ID               0xF0
#define LOWPAN_NHC_UDP_CHECKSUMC        0x04
#define LOWPAN_NHC_UDP_CHECKSUMI        0x00

#define LOWPAN_NHC_UDP_4BIT_PORT        0xF0B0
#define LOWPAN_NHC_UDP_4BIT_MASK        0xFFF0
#define LOWPAN_NHC_UDP_8BIT_PORT        0xF000
#define LOWPAN_NHC_UDP_8BIT_MASK        0xFF00

/* values for port compression, _with checksum_ ie bit 5 set to 0 */
#define LOWPAN_NHC_UDP_CS_P_00  0xF0 /* all inline */
#define LOWPAN_NHC_UDP_CS_P_01  0xF1 /* source 16bit inline,
                                        dest = 0xF0 + 8 bit inline */
#define LOWPAN_NHC_UDP_CS_P_10  0xF2 /* source = 0xF0 + 8bit inline,
                                        dest = 16 bit inline */
#define LOWPAN_NHC_UDP_CS_P_11  0xF3 /* source & dest = 0xF0B + 4bit inline */
#define LOWPAN_NHC_UDP_CS_C     0x04 /* checksum elided */

#ifdef DEBUG
/* print data in line */
static inline void raw_dump_inline(const char *caller, char *msg,
                                   unsigned char *buf, int len)
{
        if (msg)
                pr_debug("%s():%s: ", caller, msg);

        print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
}

/* print data in a table format:
 *
 * addr: xx xx xx xx xx xx
 * addr: xx xx xx xx xx xx
 * ...
 */
static inline void raw_dump_table(const char *caller, char *msg,
                                  unsigned char *buf, int len)
{
        if (msg)
                pr_debug("%s():%s:\n", caller, msg);

        print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
}
#else
static inline void raw_dump_table(const char *caller, char *msg,
                                  unsigned char *buf, int len) { }
static inline void raw_dump_inline(const char *caller, char *msg,
                                   unsigned char *buf, int len) { }
#endif

static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
{
        if (unlikely(!pskb_may_pull(skb, 1)))
                return -EINVAL;

        *val = skb->data[0];
        skb_pull(skb, 1);

        return 0;
}

static inline bool lowpan_fetch_skb(struct sk_buff *skb,
                void *data, const unsigned int len)
{
        if (unlikely(!pskb_may_pull(skb, len)))
                return true;

        skb_copy_from_linear_data(skb, data, len);
        skb_pull(skb, len);

        return false;
}

static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
                                       const size_t len)
{
        memcpy(*hc_ptr, data, len);
        *hc_ptr += len;
}

static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
{
        static const u8 addr_sizes[] = {
                [LOWPAN_IPHC_ADDR_00] = 16,
                [LOWPAN_IPHC_ADDR_01] = 8,
                [LOWPAN_IPHC_ADDR_02] = 2,
                [LOWPAN_IPHC_ADDR_03] = 0,
        };
        return addr_sizes[addr_mode];
}

static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
{
        u8 ret = 1;

        if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
                *uncomp_header += sizeof(struct udphdr);

                switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
                case LOWPAN_NHC_UDP_CS_P_00:
                        ret += 4;
                        break;
                case LOWPAN_NHC_UDP_CS_P_01:
                case LOWPAN_NHC_UDP_CS_P_10:
                        ret += 3;
                        break;
                case LOWPAN_NHC_UDP_CS_P_11:
                        ret++;
                        break;
                default:
                        break;
                }

                if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
                        ret += 2;
        }

        return ret;
}

/**
 *      lowpan_uncompress_size - returns skb->len size with uncompressed header
 *      @skb: sk_buff with 6lowpan header inside
 *      @datagram_offset: optional to get the datagram_offset value
 *
 *      Returns the skb->len with uncompressed header
 */
static inline u16
lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
{
        u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
        u8 iphc0, iphc1, h_enc;

        iphc0 = skb_network_header(skb)[0];
        iphc1 = skb_network_header(skb)[1];

        switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
        case 0:
                ret += 4;
                break;
        case 1:
                ret += 3;
                break;
        case 2:
                ret++;
                break;
        default:
                break;
        }

        if (!(iphc0 & LOWPAN_IPHC_NH_C))
                ret++;

        if (!(iphc0 & 0x03))
                ret++;

        ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
                                     LOWPAN_IPHC_SAM_BIT);

        if (iphc1 & LOWPAN_IPHC_M) {
                switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
                        LOWPAN_IPHC_DAM_BIT) {
                case LOWPAN_IPHC_DAM_00:
                        ret += 16;
                        break;
                case LOWPAN_IPHC_DAM_01:
                        ret += 6;
                        break;
                case LOWPAN_IPHC_DAM_10:
                        ret += 4;
                        break;
                case LOWPAN_IPHC_DAM_11:
                        ret++;
                        break;
                default:
                        break;
                }
        } else {
                ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
                                             LOWPAN_IPHC_DAM_BIT);
        }

        if (iphc0 & LOWPAN_IPHC_NH_C) {
                h_enc = skb_network_header(skb)[ret];
                ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
        }

        if (dgram_offset)
                *dgram_offset = uncomp_header;

        return skb->len + uncomp_header - ret;
}

typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);

int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
                const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
                const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
                u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
                        unsigned short type, const void *_daddr,
                        const void *_saddr, unsigned int len);

#endif /* __6LOWPAN_H__ */
/* [<][>][^][v][top][bottom][index][help] */
root/include/net/6lowpan.h

DEFINITIONS
