sixlowpan.h

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/*
 * SPDX-FileCopyrightText: 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
 * SPDX-License-Identifier: LGPL-2.1-only
 */
 
#pragma once

 
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
 
#include "byteorder.h"
 
#ifdef __cplusplus
extern "C" {
#endif

#define SIXLOWPAN_UNCOMP            (0x41)      
#define SIXLOWPAN_FRAG_DISP_MASK    (0xf8)      
#define SIXLOWPAN_FRAG_1_DISP       (0xc0)      
#define SIXLOWPAN_FRAG_N_DISP       (0xe0)      
#define SIXLOWPAN_FRAG_MAX_LEN      (2047)      

#define SIXLOWPAN_IPHC1_DISP_MASK   (0xe0)

#define SIXLOWPAN_IPHC1_DISP        (0x60)

#define SIXLOWPAN_SFR_DISP_MASK         (0xfe)

#define SIXLOWPAN_SFR_RFRAG_DISP        (0xe8)

#define SIXLOWPAN_SFR_ACK_DISP          (0xea)

static inline bool sixlowpan_nalp(uint8_t disp)
{
    return ((disp & 0xc0) == 0);
}


#define SIXLOWPAN_FRAG_SIZE_MASK    (0x07ff)    

typedef struct __attribute__((packed)) {
    network_uint16_t disp_size;
    network_uint16_t tag;       
} sixlowpan_frag_t;

typedef struct __attribute__((packed)) {
    network_uint16_t disp_size;
    network_uint16_t tag;       
    uint8_t offset;             
} sixlowpan_frag_n_t;

static inline bool sixlowpan_frag_1_is(sixlowpan_frag_t *hdr)
{
    return ((hdr->disp_size.u8[0] & SIXLOWPAN_FRAG_DISP_MASK) == SIXLOWPAN_FRAG_1_DISP);
}

static inline bool sixlowpan_frag_n_is(sixlowpan_frag_t *hdr)
{
    return ((hdr->disp_size.u8[0] & SIXLOWPAN_FRAG_DISP_MASK) == SIXLOWPAN_FRAG_N_DISP);
}

static inline bool sixlowpan_frag_is(sixlowpan_frag_t *hdr)
{
    return sixlowpan_frag_1_is(hdr) || sixlowpan_frag_n_is(hdr);
}

static inline uint16_t sixlowpan_frag_datagram_size(sixlowpan_frag_t *hdr)
{
    return (byteorder_ntohs(hdr->disp_size) & SIXLOWPAN_FRAG_SIZE_MASK);
}

static inline uint16_t sixlowpan_frag_datagram_tag(sixlowpan_frag_t *hdr)
{
    return byteorder_ntohs(hdr->tag);
}

static inline uint16_t sixlowpan_frag_offset(sixlowpan_frag_n_t *hdr)
{
    /* https://tools.ietf.org/html/rfc4944#section-5.3:
     * datagram_offset:  This field is present only in the second and
     *    subsequent link fragments and SHALL specify the offset, in
     *    increments of 8 octets, of the fragment from the beginning of the
     *    payload datagram. [...] */
    return (hdr->offset * 8U);
}


#define SIXLOWPAN_IPHC1_TF          (0x18)

#define SIXLOWPAN_IPHC1_NH          (0x04)

#define SIXLOWPAN_IPHC1_HL          (0x03)

#define SIXLOWPAN_IPHC2_CID_EXT     (0x80)

#define SIXLOWPAN_IPHC2_SAC         (0x40)

#define SIXLOWPAN_IPHC2_SAM         (0x30)

#define SIXLOWPAN_IPHC2_DAC         (0x04)

#define SIXLOWPAN_IPHC2_DAM         (0x03)

#define SIXLOWPAN_IPHC2_M           (0x08)

#define SIXLOWPAN_IPHC_HDR_LEN      (2)

#define SIXLOWPAN_IPHC_CID_EXT_LEN  (1)

static inline bool sixlowpan_iphc_is(uint8_t *data)
{
    return ((*data & SIXLOWPAN_IPHC1_DISP_MASK) == SIXLOWPAN_IPHC1_DISP);
}


void sixlowpan_print(uint8_t *data, size_t size);
 
#ifdef __cplusplus
}
#endif