/*
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* Copyright (c) 2007, Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This file is part of the Contiki operating system.
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*/
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/**
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* \file
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* A Chameleon module that produces bit-optimized headers
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* \author
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* Adam Dunkels <adam@sics.se>
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*/
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#include "net/rime/chameleon.h"
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#include "net/rime.h"
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#include <string.h>
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/* This option enables an optimization where the link addresses are
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left to the MAC RDC and not encoded in the Chameleon header.
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Note: this requires that the underlying MAC layer to add link
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addresses and will not work together with for example nullrdc.
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*/
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#ifdef CHAMELEON_CONF_WITH_MAC_LINK_ADDRESSES
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#define CHAMELEON_WITH_MAC_LINK_ADDRESSES CHAMELEON_CONF_WITH_MAC_LINK_ADDRESSES
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#else /* !CHAMELEON_CONF_WITH_MAC_LINK_ADDRESSES */
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#define CHAMELEON_WITH_MAC_LINK_ADDRESSES 0
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#endif /* !CHAMELEON_CONF_WITH_MAC_LINK_ADDRESSES */
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struct bitopt_hdr {
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uint8_t channel[2];
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};
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static const uint8_t bitmask[9] = { 0x00, 0x80, 0xc0, 0xe0, 0xf0,
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0xf8, 0xfc, 0xfe, 0xff };
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#define DEBUG 0
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#if DEBUG
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#include <stdio.h>
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#define PRINTF(...) printf(__VA_ARGS__)
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#else
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#define PRINTF(...)
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#endif
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/*---------------------------------------------------------------------------*/
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uint8_t CC_INLINE
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get_bits_in_byte(uint8_t *from, int bitpos, int vallen)
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{
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uint16_t shifted_val;
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shifted_val = (from[0] << 8) | from[1];
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/* PRINTF("get_bits_in_byte: from[0] 0x%02x from[1] 0x%02x shifted_val 0x%04x, return 0x%02x vallen %d\n",
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from[0], from[1], shifted_val,
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(((shifted_val << bitpos) >> 8) & bitmask[vallen]) >> (8 - vallen),
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vallen
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);*/
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return (((shifted_val << bitpos) >> 8) & bitmask[vallen]) >> (8 - vallen);
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}
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/*---------------------------------------------------------------------------*/
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void
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get_bits(uint8_t *to, uint8_t *from, int bitpos, int vallen)
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{
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int i, bits;
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if(vallen < 8) {
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*to = get_bits_in_byte(from, bitpos, vallen);
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} else {
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if(bitpos == 0) {
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for(i = 0; i < vallen / 8; ++i) {
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/* PRINTF("get_bits i %d val 0x%02x\n",
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i, from[i]);*/
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to[i] = from[i];
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}
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bits = vallen & 7;
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if(bits) {
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to[i] = get_bits_in_byte(&from[i], 0, bits);
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}
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} else {
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for(i = 0; i < vallen / 8; ++i) {
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/* PRINTF("get_bits i %d val 0x%02x bitpos %d\n",
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i, from[i], bitpos);*/
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to[i] = get_bits_in_byte(&from[i], bitpos, 8);
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}
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bits = vallen & 7;
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if(bits) {
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to[i] = get_bits_in_byte(&from[i], bitpos, bits);
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}
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}
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}
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}
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/*---------------------------------------------------------------------------*/
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static int
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header_size(const struct packetbuf_attrlist *a)
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{
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int size, len;
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/* Compute the total size of the final header by summing the size of
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all attributes that are used on this channel. */
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size = 0;
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for(; a->type != PACKETBUF_ATTR_NONE; ++a) {
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#if CHAMELEON_WITH_MAC_LINK_ADDRESSES
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if(a->type == PACKETBUF_ADDR_SENDER ||
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a->type == PACKETBUF_ADDR_RECEIVER) {
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/* Let the link layer handle sender and receiver */
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continue;
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}
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#endif /* CHAMELEON_WITH_MAC_LINK_ADDRESSES */
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/* PRINTF("chameleon header_size: header type %d len %d\n",
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a->type, a->len);*/
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len = a->len;
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/* if(len < 8) {
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len = 8;
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}*/
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size += len;
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}
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return size;
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}
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/*---------------------------------------------------------------------------*/
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void CC_INLINE
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set_bits_in_byte(uint8_t *target, int bitpos, uint8_t val, int vallen)
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{
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unsigned short shifted_val;
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shifted_val = val << (8 - bitpos + 8 - vallen);
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/* printf("set_bits_in_byte before target[0] 0x%02x target[1] 0x%02x shifted_val 0x%04x val 0x%02x vallen %d\n",
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target[0], target[1], shifted_val, val, vallen);*/
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target[0] |= shifted_val >> 8;
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target[1] |= shifted_val & 0xff;
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}
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/*---------------------------------------------------------------------------*/
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void
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set_bits(uint8_t *ptr, int bitpos, uint8_t *val, int vallen)
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{
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int i, bits;
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/* PRINTF("set_bits %p bitpos %d, val %p len %d\n",
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ptr, bitpos, val, vallen);*/
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if(vallen < 8) {
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set_bits_in_byte(ptr, bitpos, *val /*>> (8 - vallen)*/, vallen);
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} else {
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if(bitpos == 0) {
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for(i = 0; i < vallen / 8; ++i) {
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/* PRINTF("set_bits i %d val %d\n",
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i, val[i]);*/
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ptr[i] = val[i];
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}
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bits = vallen & 7;
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if(bits) {
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set_bits_in_byte(&ptr[i], 0, val[i] >> (8 - bits), bits);
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}
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} else {
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for(i = 0; i < vallen / 8; ++i) {
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/* PRINTF("set_bits i %d val %d\n",
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i, val[i]);*/
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set_bits_in_byte(&ptr[i], bitpos, val[i], 8);
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}
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bits = vallen & 7;
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if(bits) {
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set_bits_in_byte(&ptr[i], 0, val[i] >> (8 - bits + bitpos), bits);
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}
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}
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}
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}
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/*---------------------------------------------------------------------------*/
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#if 0
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static void
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printbin(int n, int digits)
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{
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int i;
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char output[128];
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for(i = 0; i < digits; ++i) {
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output[digits - i - 1] = (n & 1) + '0';
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n >>= 1;
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}
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output[i] = 0;
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printf(output);
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}
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static void
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printhdr(uint8_t *hdr, int len)
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{
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int i, j;
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j = 0;
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for(i = 0; i < len; ++i) {
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printbin(hdr[i], 8);
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printf(", ");
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++j;
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if(j == 10) {
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printf("\n");
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j = 0;
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}
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}
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if(j != 0) {
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printf("\n");
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}
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}
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#endif
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/*---------------------------------------------------------------------------*/
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static int
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pack_header(struct channel *c)
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{
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const struct packetbuf_attrlist *a;
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int hdrbytesize;
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int byteptr, bitptr, len;
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uint8_t *hdrptr;
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struct bitopt_hdr *hdr;
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/* Compute the total size of the final header by summing the size of
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all attributes that are used on this channel. */
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hdrbytesize = c->hdrsize / 8 + ((c->hdrsize & 7) == 0? 0: 1);
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if(packetbuf_hdralloc(hdrbytesize + sizeof(struct bitopt_hdr)) == 0) {
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PRINTF("chameleon-bitopt: insufficient space for headers\n");
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return 0;
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}
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hdr = (struct bitopt_hdr *)packetbuf_hdrptr();
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hdr->channel[0] = c->channelno & 0xff;
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hdr->channel[1] = (c->channelno >> 8) & 0xff;
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hdrptr = ((uint8_t *)packetbuf_hdrptr()) + sizeof(struct bitopt_hdr);
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memset(hdrptr, 0, hdrbytesize);
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byteptr = bitptr = 0;
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for(a = c->attrlist; a->type != PACKETBUF_ATTR_NONE; ++a) {
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#if CHAMELEON_WITH_MAC_LINK_ADDRESSES
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if(a->type == PACKETBUF_ADDR_SENDER ||
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a->type == PACKETBUF_ADDR_RECEIVER) {
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/* Let the link layer handle sender and receiver */
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PRINTF("%d.%d: pack_header leaving sender/receiver to link layer\n");
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continue;
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}
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#endif /* CHAMELEON_WITH_MAC_LINK_ADDRESSES */
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PRINTF("%d.%d: pack_header type %d, len %d, bitptr %d, ",
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rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
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a->type, a->len, bitptr);
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/* len = (a->len & 0xf8) + ((a->len & 7) ? 8: 0);*/
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len = a->len;
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byteptr = bitptr / 8;
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if(PACKETBUF_IS_ADDR(a->type)) {
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set_bits(&hdrptr[byteptr], bitptr & 7,
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(uint8_t *)packetbuf_addr(a->type), len);
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PRINTF("address %d.%d\n",
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/* rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],*/
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((uint8_t *)packetbuf_addr(a->type))[0],
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((uint8_t *)packetbuf_addr(a->type))[1]);
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} else {
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packetbuf_attr_t val;
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val = packetbuf_attr(a->type);
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set_bits(&hdrptr[byteptr], bitptr & 7,
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(uint8_t *)&val, len);
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PRINTF("value %d\n",
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/*rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],*/
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val);
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}
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/* printhdr(hdrptr, hdrbytesize);*/
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bitptr += len;
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}
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/* printhdr(hdrptr, hdrbytesize);*/
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return 1; /* Send out packet */
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}
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/*---------------------------------------------------------------------------*/
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static struct channel *
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unpack_header(void)
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{
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const struct packetbuf_attrlist *a;
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int byteptr, bitptr, len;
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int hdrbytesize;
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uint8_t *hdrptr;
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struct bitopt_hdr *hdr;
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struct channel *c;
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/* The packet has a header that tells us what channel the packet is
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for. */
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hdr = (struct bitopt_hdr *)packetbuf_dataptr();
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if(packetbuf_hdrreduce(sizeof(struct bitopt_hdr)) == 0) {
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PRINTF("chameleon-bitopt: too short packet\n");
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return NULL;
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}
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c = channel_lookup((hdr->channel[1] << 8) + hdr->channel[0]);
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if(c == NULL) {
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PRINTF("chameleon-bitopt: input: channel %u not found\n",
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(hdr->channel[1] << 8) + hdr->channel[0]);
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return NULL;
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}
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hdrptr = packetbuf_dataptr();
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hdrbytesize = c->hdrsize / 8 + ((c->hdrsize & 7) == 0? 0: 1);
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if(packetbuf_hdrreduce(hdrbytesize) == 0) {
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PRINTF("chameleon-bitopt: too short packet\n");
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return NULL;
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}
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byteptr = bitptr = 0;
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for(a = c->attrlist; a->type != PACKETBUF_ATTR_NONE; ++a) {
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#if CHAMELEON_WITH_MAC_LINK_ADDRESSES
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if(a->type == PACKETBUF_ADDR_SENDER ||
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a->type == PACKETBUF_ADDR_RECEIVER) {
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/* Let the link layer handle sender and receiver */
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continue;
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}
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#endif /* CHAMELEON_WITH_MAC_LINK_ADDRESSES */
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PRINTF("%d.%d: unpack_header type %d, len %d, bitptr %d\n",
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rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
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a->type, a->len, bitptr);
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/* len = (a->len & 0xf8) + ((a->len & 7) ? 8: 0);*/
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len = a->len;
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byteptr = bitptr / 8;
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if(PACKETBUF_IS_ADDR(a->type)) {
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rimeaddr_t addr;
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get_bits((uint8_t *)&addr, &hdrptr[byteptr], bitptr & 7, len);
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PRINTF("%d.%d: unpack_header type %d, addr %d.%d\n",
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rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
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a->type, addr.u8[0], addr.u8[1]);
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packetbuf_set_addr(a->type, &addr);
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} else {
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packetbuf_attr_t val = 0;
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get_bits((uint8_t *)&val, &hdrptr[byteptr], bitptr & 7, len);
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packetbuf_set_attr(a->type, val);
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PRINTF("%d.%d: unpack_header type %d, val %d\n",
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rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
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a->type, val);
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}
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/* byteptr += len / 8;*/
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bitptr += len;
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}
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return c;
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}
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/*---------------------------------------------------------------------------*/
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CC_CONST_FUNCTION struct chameleon_module chameleon_bitopt = {
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unpack_header,
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pack_header,
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header_size
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};
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/*---------------------------------------------------------------------------*/
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