nes-proj/os/services/orchestra/orchestra-rule-eb-per-time-source.c

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/*
* Copyright (c) 2015, 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.
*
*/
/**
* \file
* Orchestra: a slotframe dedicated to transmission of EBs.
* Nodes transmit at a timeslot defined as hash(MAC) % ORCHESTRA_EBSF_PERIOD
* Nodes listen at a timeslot defined as hash(time_source.MAC) % ORCHESTRA_EBSF_PERIOD
* \author Simon Duquennoy <simonduq@sics.se>
*/
#include "contiki.h"
#include "orchestra.h"
#include "net/packetbuf.h"
static uint16_t slotframe_handle = 0;
static uint16_t channel_offset = 0;
static struct tsch_slotframe *sf_eb;
/*---------------------------------------------------------------------------*/
static uint16_t
get_node_timeslot(const linkaddr_t *addr)
{
#if ORCHESTRA_EBSF_PERIOD > 0
return ORCHESTRA_LINKADDR_HASH(addr) % ORCHESTRA_EBSF_PERIOD;
#else
return 0xffff;
#endif
}
/*---------------------------------------------------------------------------*/
static int
select_packet(uint16_t *slotframe, uint16_t *timeslot)
{
/* Select EBs only */
if(packetbuf_attr(PACKETBUF_ATTR_FRAME_TYPE) == FRAME802154_BEACONFRAME) {
if(slotframe != NULL) {
*slotframe = slotframe_handle;
}
if(timeslot != NULL) {
*timeslot = get_node_timeslot(&linkaddr_node_addr);
}
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
static void
new_time_source(const struct tsch_neighbor *old, const struct tsch_neighbor *new)
{
uint16_t old_ts = old != NULL ? get_node_timeslot(&old->addr) : 0xffff;
uint16_t new_ts = new != NULL ? get_node_timeslot(&new->addr) : 0xffff;
if(new_ts == old_ts) {
return;
}
if(old_ts != 0xffff) {
/* Stop listening to the old time source's EBs */
if(old_ts == get_node_timeslot(&linkaddr_node_addr)) {
/* This was the same timeslot as slot. Reset original link options */
tsch_schedule_add_link(sf_eb, LINK_OPTION_TX, LINK_TYPE_ADVERTISING_ONLY,
&tsch_broadcast_address, old_ts, 0);
} else {
/* Remove slot */
tsch_schedule_remove_link_by_timeslot(sf_eb, old_ts);
}
}
if(new_ts != 0xffff) {
uint8_t link_options = LINK_OPTION_RX;
if(new_ts == get_node_timeslot(&linkaddr_node_addr)) {
/* This is also our timeslot, add necessary flags */
link_options |= LINK_OPTION_TX;
}
/* Listen to the time source's EBs */
tsch_schedule_add_link(sf_eb, link_options, LINK_TYPE_ADVERTISING_ONLY,
&tsch_broadcast_address, new_ts, 0);
}
}
/*---------------------------------------------------------------------------*/
static void
init(uint16_t sf_handle)
{
slotframe_handle = sf_handle;
channel_offset = sf_handle;
sf_eb = tsch_schedule_add_slotframe(slotframe_handle, ORCHESTRA_EBSF_PERIOD);
/* EB link: every neighbor uses its own to avoid contention */
tsch_schedule_add_link(sf_eb,
LINK_OPTION_TX,
LINK_TYPE_ADVERTISING_ONLY, &tsch_broadcast_address,
get_node_timeslot(&linkaddr_node_addr), 0);
}
/*---------------------------------------------------------------------------*/
struct orchestra_rule eb_per_time_source = {
init,
new_time_source,
select_packet,
NULL,
NULL,
};