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contiki/core/net/mac/tsch/tsch.c
kkrentz 10d8b05bc6 llsec: Permit dynamic security levels
2016-04-13 07:54:46 -07:00

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/*
* Copyright (c) 2015, SICS Swedish ICT.
* 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.
*
* This file is part of the Contiki operating system.
*
*/
/**
* \file
* IEEE 802.15.4 TSCH MAC implementation.
* Does not use any RDC layer. Should be used with nordc.
* \author
* Simon Duquennoy <simonduq@sics.se>
* Beshr Al Nahas <beshr@sics.se>
*
*/
#include "contiki.h"
#include "dev/radio.h"
#include "net/netstack.h"
#include "net/packetbuf.h"
#include "net/queuebuf.h"
#include "net/mac/framer-802154.h"
#include "net/mac/tsch/tsch.h"
#include "net/mac/tsch/tsch-slot-operation.h"
#include "net/mac/tsch/tsch-queue.h"
#include "net/mac/tsch/tsch-private.h"
#include "net/mac/tsch/tsch-log.h"
#include "net/mac/tsch/tsch-packet.h"
#include "net/mac/tsch/tsch-security.h"
#include "lib/random.h"
#if FRAME802154_VERSION < FRAME802154_IEEE802154E_2012
#error TSCH: FRAME802154_VERSION must be at least FRAME802154_IEEE802154E_2012
#endif
#if TSCH_LOG_LEVEL >= 1
#define DEBUG DEBUG_PRINT
#else /* TSCH_LOG_LEVEL */
#define DEBUG DEBUG_NONE
#endif /* TSCH_LOG_LEVEL */
#include "net/ip/uip-debug.h"
/* Use to collect link statistics even on Keep-Alive, even though they were
* not sent from an upper layer and don't have a valid packet_sent callback */
#ifndef TSCH_LINK_NEIGHBOR_CALLBACK
void uip_ds6_link_neighbor_callback(int status, int numtx);
#define TSCH_LINK_NEIGHBOR_CALLBACK(dest, status, num) uip_ds6_link_neighbor_callback(status, num)
#endif /* TSCH_LINK_NEIGHBOR_CALLBACK */
/* 802.15.4 duplicate frame detection */
struct seqno {
linkaddr_t sender;
uint8_t seqno;
};
/* Size of the sequence number history */
#ifdef NETSTACK_CONF_MAC_SEQNO_HISTORY
#define MAX_SEQNOS NETSTACK_CONF_MAC_SEQNO_HISTORY
#else /* NETSTACK_CONF_MAC_SEQNO_HISTORY */
#define MAX_SEQNOS 8
#endif /* NETSTACK_CONF_MAC_SEQNO_HISTORY */
/* Seqno history */
static struct seqno received_seqnos[MAX_SEQNOS];
/* Let TSCH select a time source with no help of an upper layer.
* We do so using statistics from incoming EBs */
#if TSCH_AUTOSELECT_TIME_SOURCE
int best_neighbor_eb_count;
struct eb_stat {
int rx_count;
int jp;
};
NBR_TABLE(struct eb_stat, eb_stats);
#endif /* TSCH_AUTOSELECT_TIME_SOURCE */
/* TSCH channel hopping sequence */
uint8_t tsch_hopping_sequence[TSCH_HOPPING_SEQUENCE_MAX_LEN];
struct asn_divisor_t tsch_hopping_sequence_length;
/* Default TSCH timeslot timing (in micro-second) */
static const uint16_t tsch_default_timing_us[tsch_ts_elements_count] = {
TSCH_DEFAULT_TS_CCA_OFFSET,
TSCH_DEFAULT_TS_CCA,
TSCH_DEFAULT_TS_TX_OFFSET,
TSCH_DEFAULT_TS_RX_OFFSET,
TSCH_DEFAULT_TS_RX_ACK_DELAY,
TSCH_DEFAULT_TS_TX_ACK_DELAY,
TSCH_DEFAULT_TS_RX_WAIT,
TSCH_DEFAULT_TS_ACK_WAIT,
TSCH_DEFAULT_TS_RX_TX,
TSCH_DEFAULT_TS_MAX_ACK,
TSCH_DEFAULT_TS_MAX_TX,
TSCH_DEFAULT_TS_TIMESLOT_LENGTH,
};
/* TSCH timeslot timing (in rtimer ticks) */
rtimer_clock_t tsch_timing[tsch_ts_elements_count];
#if LINKADDR_SIZE == 8
/* 802.15.4 broadcast MAC address */
const linkaddr_t tsch_broadcast_address = { { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff } };
/* Address used for the EB virtual neighbor queue */
const linkaddr_t tsch_eb_address = { { 0, 0, 0, 0, 0, 0, 0, 0 } };
#else /* LINKADDR_SIZE == 8 */
const linkaddr_t tsch_broadcast_address = { { 0xff, 0xff } };
const linkaddr_t tsch_eb_address = { { 0, 0 } };
#endif /* LINKADDR_SIZE == 8 */
/* Is TSCH started? */
int tsch_is_started = 0;
/* Has TSCH initialization failed? */
int tsch_is_initialized = 0;
/* Are we coordinator of the TSCH network? */
int tsch_is_coordinator = 0;
/* Are we associated to a TSCH network? */
int tsch_is_associated = 0;
/* Is the PAN running link-layer security? */
int tsch_is_pan_secured = LLSEC802154_ENABLED;
/* The current Absolute Slot Number (ASN) */
struct asn_t current_asn;
/* Device rank or join priority:
* For PAN coordinator: 0 -- lower is better */
uint8_t tsch_join_priority;
/* The current TSCH sequence number, used for both data and EBs */
static uint8_t tsch_packet_seqno = 0;
/* Current period for EB output */
static clock_time_t tsch_current_eb_period;
/* timer for sending keepalive messages */
static struct ctimer keepalive_timer;
/* TSCH processes and protothreads */
PT_THREAD(tsch_scan(struct pt *pt));
PROCESS(tsch_process, "TSCH: main process");
PROCESS(tsch_send_eb_process, "TSCH: send EB process");
PROCESS(tsch_pending_events_process, "TSCH: pending events process");
/* Other function prototypes */
static void packet_input(void);
/* Getters and setters */
/*---------------------------------------------------------------------------*/
void
tsch_set_coordinator(int enable)
{
tsch_is_coordinator = enable;
tsch_set_eb_period(TSCH_EB_PERIOD);
}
/*---------------------------------------------------------------------------*/
void
tsch_set_pan_secured(int enable)
{
tsch_is_pan_secured = LLSEC802154_ENABLED && enable;
}
/*---------------------------------------------------------------------------*/
void
tsch_set_join_priority(uint8_t jp)
{
tsch_join_priority = jp;
}
/*---------------------------------------------------------------------------*/
void
tsch_set_eb_period(uint32_t period)
{
tsch_current_eb_period = period;
}
/*---------------------------------------------------------------------------*/
static void
tsch_reset(void)
{
int i;
frame802154_set_pan_id(0xffff);
/* First make sure pending packet callbacks are sent etc */
process_post_synch(&tsch_pending_events_process, PROCESS_EVENT_POLL, NULL);
/* Reset neighbor queues */
tsch_queue_reset();
/* Remove unused neighbors */
tsch_queue_free_unused_neighbors();
tsch_queue_update_time_source(NULL);
/* Initialize global variables */
tsch_join_priority = 0xff;
ASN_INIT(current_asn, 0, 0);
current_link = NULL;
/* Reset timeslot timing to defaults */
for(i = 0; i < tsch_ts_elements_count; i++) {
tsch_timing[i] = US_TO_RTIMERTICKS(tsch_default_timing_us[i]);
}
#ifdef TSCH_CALLBACK_LEAVING_NETWORK
TSCH_CALLBACK_LEAVING_NETWORK();
#endif
#if TSCH_AUTOSELECT_TIME_SOURCE
best_neighbor_eb_count = 0;
nbr_table_register(eb_stats, NULL);
tsch_set_eb_period(TSCH_EB_PERIOD);
#endif
}
/* TSCH keep-alive functions */
/*---------------------------------------------------------------------------*/
/* Tx callback for keepalive messages */
static void
keepalive_packet_sent(void *ptr, int status, int transmissions)
{
#ifdef TSCH_LINK_NEIGHBOR_CALLBACK
TSCH_LINK_NEIGHBOR_CALLBACK(packetbuf_addr(PACKETBUF_ADDR_RECEIVER), status, transmissions);
#endif
PRINTF("TSCH: KA sent to %u, st %d-%d\n",
TSCH_LOG_ID_FROM_LINKADDR(packetbuf_addr(PACKETBUF_ADDR_RECEIVER)), status, transmissions);
tsch_schedule_keepalive();
}
/*---------------------------------------------------------------------------*/
/* Prepare and send a keepalive message */
static void
keepalive_send()
{
if(tsch_is_associated) {
struct tsch_neighbor *n = tsch_queue_get_time_source();
/* Simply send an empty packet */
packetbuf_clear();
packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, &n->addr);
NETSTACK_LLSEC.send(keepalive_packet_sent, NULL);
PRINTF("TSCH: sending KA to %u\n",
TSCH_LOG_ID_FROM_LINKADDR(&n->addr));
}
}
/*---------------------------------------------------------------------------*/
/* Set ctimer to send a keepalive message after expiration of TSCH_KEEPALIVE_TIMEOUT */
void
tsch_schedule_keepalive()
{
/* Pick a delay in the range [TSCH_KEEPALIVE_TIMEOUT*0.9, TSCH_KEEPALIVE_TIMEOUT[ */
if(!tsch_is_coordinator && tsch_is_associated) {
unsigned long delay = (TSCH_KEEPALIVE_TIMEOUT - TSCH_KEEPALIVE_TIMEOUT / 10)
+ random_rand() % (TSCH_KEEPALIVE_TIMEOUT / 10);
ctimer_set(&keepalive_timer, delay, keepalive_send, NULL);
}
}
/*---------------------------------------------------------------------------*/
static void
eb_input(struct input_packet *current_input)
{
/* PRINTF("TSCH: EB received\n"); */
frame802154_t frame;
/* Verify incoming EB (does its ASN match our Rx time?),
* and update our join priority. */
struct ieee802154_ies eb_ies;
if(tsch_packet_parse_eb(current_input->payload, current_input->len,
&frame, &eb_ies, NULL, 1)) {
/* PAN ID check and authentication done at rx time */
#if TSCH_AUTOSELECT_TIME_SOURCE
if(!tsch_is_coordinator) {
/* Maintain EB received counter for every neighbor */
struct eb_stat *stat = (struct eb_stat *)nbr_table_get_from_lladdr(eb_stats, &frame.src_addr);
if(stat == NULL) {
stat = (struct eb_stat *)nbr_table_add_lladdr(eb_stats, &frame.src_addr);
}
if(stat != NULL) {
stat->rx_count++;
stat->jp = eb_ies.join_priority;
best_neighbor_eb_count = MAX(best_neighbor_eb_count, stat->rx_count);
}
/* Select best time source */
struct eb_stat *best_stat = NULL;
stat = nbr_table_head(eb_stats);
while(stat != NULL) {
/* Is neighbor eligible as a time source? */
if(stat->rx_count > best_neighbor_eb_count / 2) {
if(best_stat == NULL ||
stat->jp < best_stat->jp) {
best_stat = stat;
}
}
stat = nbr_table_next(eb_stats, stat);
}
/* Update time source */
if(best_stat != NULL) {
tsch_queue_update_time_source(nbr_table_get_lladdr(eb_stats, best_stat));
tsch_join_priority = best_stat->jp + 1;
}
}
#endif
struct tsch_neighbor *n = tsch_queue_get_time_source();
/* Did the EB come from our time source? */
if(n != NULL && linkaddr_cmp((linkaddr_t *)&frame.src_addr, &n->addr)) {
/* Check for ASN drift */
int32_t asn_diff = ASN_DIFF(current_input->rx_asn, eb_ies.ie_asn);
if(asn_diff != 0) {
/* We disagree with our time source's ASN -- leave the network */
PRINTF("TSCH:! ASN drifted by %ld, leaving the network\n", asn_diff);
tsch_disassociate();
}
if(eb_ies.ie_join_priority >= TSCH_MAX_JOIN_PRIORITY) {
/* Join priority unacceptable. Leave network. */
PRINTF("TSCH:! EB JP too high %u, leaving the network\n",
eb_ies.ie_join_priority);
tsch_disassociate();
} else {
#if TSCH_AUTOSELECT_TIME_SOURCE
/* Update join priority */
if(tsch_join_priority != eb_ies.ie_join_priority + 1) {
PRINTF("TSCH: update JP from EB %u -> %u\n",
tsch_join_priority, eb_ies.ie_join_priority + 1);
tsch_join_priority = eb_ies.ie_join_priority + 1;
}
#endif /* TSCH_AUTOSELECT_TIME_SOURCE */
}
}
}
}
/*---------------------------------------------------------------------------*/
/* Process pending input packet(s) */
static void
tsch_rx_process_pending()
{
int16_t input_index;
/* Loop on accessing (without removing) a pending input packet */
while((input_index = ringbufindex_peek_get(&input_ringbuf)) != -1) {
struct input_packet *current_input = &input_array[input_index];
frame802154_t frame;
uint8_t ret = frame802154_parse(current_input->payload, current_input->len, &frame);
int is_data = ret && frame.fcf.frame_type == FRAME802154_DATAFRAME;
int is_eb = ret
&& frame.fcf.frame_version == FRAME802154_IEEE802154E_2012
&& frame.fcf.frame_type == FRAME802154_BEACONFRAME;
if(is_data) {
/* Skip EBs and other control messages */
/* Copy to packetbuf for processing */
packetbuf_copyfrom(current_input->payload, current_input->len);
packetbuf_set_attr(PACKETBUF_ATTR_RSSI, current_input->rssi);
}
/* Remove input from ringbuf */
ringbufindex_get(&input_ringbuf);
if(is_data) {
/* Pass to upper layers */
packet_input();
} else if(is_eb) {
eb_input(current_input);
}
}
}
/*---------------------------------------------------------------------------*/
/* Pass sent packets to upper layer */
static void
tsch_tx_process_pending()
{
int16_t dequeued_index;
/* Loop on accessing (without removing) a pending input packet */
while((dequeued_index = ringbufindex_peek_get(&dequeued_ringbuf)) != -1) {
struct tsch_packet *p = dequeued_array[dequeued_index];
/* Put packet into packetbuf for packet_sent callback */
queuebuf_to_packetbuf(p->qb);
/* Call packet_sent callback */
mac_call_sent_callback(p->sent, p->ptr, p->ret, p->transmissions);
/* Free packet queuebuf */
tsch_queue_free_packet(p);
/* Free all unused neighbors */
tsch_queue_free_unused_neighbors();
/* Remove dequeued packet from ringbuf */
ringbufindex_get(&dequeued_ringbuf);
}
}
/*---------------------------------------------------------------------------*/
/* Setup TSCH as a coordinator */
static void
tsch_start_coordinator(void)
{
frame802154_set_pan_id(IEEE802154_PANID);
/* Initialize hopping sequence as default */
memcpy(tsch_hopping_sequence, TSCH_DEFAULT_HOPPING_SEQUENCE, sizeof(TSCH_DEFAULT_HOPPING_SEQUENCE));
ASN_DIVISOR_INIT(tsch_hopping_sequence_length, sizeof(TSCH_DEFAULT_HOPPING_SEQUENCE));
#if TSCH_SCHEDULE_WITH_6TISCH_MINIMAL
tsch_schedule_create_minimal();
#endif
tsch_is_associated = 1;
tsch_join_priority = 0;
PRINTF("TSCH: starting as coordinator, PAN ID %x, asn-%x.%lx\n",
frame802154_get_pan_id(), current_asn.ms1b, current_asn.ls4b);
/* Start slot operation */
tsch_slot_operation_sync(RTIMER_NOW(), &current_asn);
}
/*---------------------------------------------------------------------------*/
/* Leave the TSCH network */
void
tsch_disassociate(void)
{
if(tsch_is_associated == 1) {
tsch_is_associated = 0;
process_post(&tsch_process, PROCESS_EVENT_POLL, NULL);
PRINTF("TSCH: leaving the network\n");
}
}
/*---------------------------------------------------------------------------*/
/* Attempt to associate to a network form an incoming EB */
static int
tsch_associate(const struct input_packet *input_eb, rtimer_clock_t timestamp)
{
frame802154_t frame;
struct ieee802154_ies ies;
uint8_t hdrlen;
int i;
if(input_eb == NULL || tsch_packet_parse_eb(input_eb->payload, input_eb->len,
&frame, &ies, &hdrlen, 0) == 0) {
PRINTF("TSCH:! failed to parse EB (len %u)\n", input_eb->len);
return 0;
}
current_asn = ies.ie_asn;
tsch_join_priority = ies.ie_join_priority + 1;
#if TSCH_JOIN_SECURED_ONLY
if(frame.fcf.security_enabled == 0) {
PRINTF("TSCH:! parse_eb: EB is not secured\n");
return 0;
}
#endif /* TSCH_JOIN_SECURED_ONLY */
#if LLSEC802154_ENABLED
if(!tsch_security_parse_frame(input_eb->payload, hdrlen,
input_eb->len - hdrlen - tsch_security_mic_len(&frame),
&frame, (linkaddr_t*)&frame.src_addr, &current_asn)) {
PRINTF("TSCH:! parse_eb: failed to authenticate\n");
return 0;
}
#endif /* LLSEC802154_ENABLED */
#if !LLSEC802154_ENABLED
if(frame.fcf.security_enabled == 1) {
PRINTF("TSCH:! parse_eb: we do not support security, but EB is secured\n");
return 0;
}
#endif /* !LLSEC802154_ENABLED */
#if TSCH_JOIN_MY_PANID_ONLY
/* Check if the EB comes from the PAN ID we expect */
if(frame.src_pid != IEEE802154_PANID) {
PRINTF("TSCH:! parse_eb: PAN ID %x != %x\n", frame.src_pid, IEEE802154_PANID);
return 0;
}
#endif /* TSCH_JOIN_MY_PANID_ONLY */
/* There was no join priority (or 0xff) in the EB, do not join */
if(ies.ie_join_priority == 0xff) {
PRINTF("TSCH:! parse_eb: no join priority\n");
return 0;
}
/* TSCH timeslot timing */
for(i = 0; i < tsch_ts_elements_count; i++) {
if(ies.ie_tsch_timeslot_id == 0) {
tsch_timing[i] = US_TO_RTIMERTICKS(tsch_default_timing_us[i]);
} else {
tsch_timing[i] = US_TO_RTIMERTICKS(ies.ie_tsch_timeslot[i]);
}
}
/* TSCH hopping sequence */
if(ies.ie_channel_hopping_sequence_id == 0) {
memcpy(tsch_hopping_sequence, TSCH_DEFAULT_HOPPING_SEQUENCE, sizeof(TSCH_DEFAULT_HOPPING_SEQUENCE));
ASN_DIVISOR_INIT(tsch_hopping_sequence_length, sizeof(TSCH_DEFAULT_HOPPING_SEQUENCE));
} else {
if(ies.ie_hopping_sequence_len <= sizeof(tsch_hopping_sequence)) {
memcpy(tsch_hopping_sequence, ies.ie_hopping_sequence_list, ies.ie_hopping_sequence_len);
ASN_DIVISOR_INIT(tsch_hopping_sequence_length, ies.ie_hopping_sequence_len);
} else {
PRINTF("TSCH:! parse_eb: hopping sequence too long (%u)\n", ies.ie_hopping_sequence_len);
return 0;
}
}
#if TSCH_CHECK_TIME_AT_ASSOCIATION > 0
/* Divide by 4k and multiply again to avoid integer overflow */
uint32_t expected_asn = 4096 * TSCH_CLOCK_TO_SLOTS(clock_time() / 4096, tsch_timing_timeslot_length); /* Expected ASN based on our current time*/
int32_t asn_threshold = TSCH_CHECK_TIME_AT_ASSOCIATION * 60ul * TSCH_CLOCK_TO_SLOTS(CLOCK_SECOND, tsch_timing_timeslot_length);
int32_t asn_diff = (int32_t)current_asn.ls4b - expected_asn;
if(asn_diff > asn_threshold) {
PRINTF("TSCH:! EB ASN rejected %lx %lx %ld\n",
current_asn.ls4b, expected_asn, asn_diff);
return 0;
}
#endif
#if TSCH_INIT_SCHEDULE_FROM_EB
/* Create schedule */
if(ies.ie_tsch_slotframe_and_link.num_slotframes == 0) {
#if TSCH_SCHEDULE_WITH_6TISCH_MINIMAL
PRINTF("TSCH: parse_eb: no schedule, setting up minimal schedule\n");
tsch_schedule_create_minimal();
#else
PRINTF("TSCH: parse_eb: no schedule\n");
#endif
} else {
/* First, empty current schedule */
tsch_schedule_remove_all_slotframes();
/* We support only 0 or 1 slotframe in this IE */
int num_links = ies.ie_tsch_slotframe_and_link.num_links;
if(num_links <= FRAME802154E_IE_MAX_LINKS) {
int i;
struct tsch_slotframe *sf = tsch_schedule_add_slotframe(
ies.ie_tsch_slotframe_and_link.slotframe_handle,
ies.ie_tsch_slotframe_and_link.slotframe_size);
for(i = 0; i < num_links; i++) {
tsch_schedule_add_link(sf,
ies.ie_tsch_slotframe_and_link.links[i].link_options,
LINK_TYPE_ADVERTISING, &tsch_broadcast_address,
ies.ie_tsch_slotframe_and_link.links[i].timeslot, ies.ie_tsch_slotframe_and_link.links[i].channel_offset);
}
} else {
PRINTF("TSCH:! parse_eb: too many links in schedule (%u)\n", num_links);
return 0;
}
}
#endif /* TSCH_INIT_SCHEDULE_FROM_EB */
if(tsch_join_priority < TSCH_MAX_JOIN_PRIORITY) {
struct tsch_neighbor *n;
/* Add coordinator to list of neighbors, lock the entry */
n = tsch_queue_add_nbr((linkaddr_t *)&frame.src_addr);
if(n != NULL) {
tsch_queue_update_time_source((linkaddr_t *)&frame.src_addr);
#ifdef TSCH_CALLBACK_JOINING_NETWORK
TSCH_CALLBACK_JOINING_NETWORK();
#endif
/* Set PANID */
frame802154_set_pan_id(frame.src_pid);
/* Synchronize on EB */
tsch_slot_operation_sync(timestamp - tsch_timing[tsch_ts_tx_offset], &current_asn);
/* Update global flags */
tsch_is_associated = 1;
tsch_is_pan_secured = frame.fcf.security_enabled;
/* Association done, schedule keepalive messages */
tsch_schedule_keepalive();
PRINTF("TSCH: association done, sec %u, PAN ID %x, asn-%x.%lx, jp %u, timeslot id %u, hopping id %u, slotframe len %u with %u links, from ",
tsch_is_pan_secured,
frame.src_pid,
current_asn.ms1b, current_asn.ls4b, tsch_join_priority,
ies.ie_tsch_timeslot_id,
ies.ie_channel_hopping_sequence_id,
ies.ie_tsch_slotframe_and_link.slotframe_size,
ies.ie_tsch_slotframe_and_link.num_links);
PRINTLLADDR((const uip_lladdr_t *)&frame.src_addr);
PRINTF("\n");
return 1;
}
}
PRINTF("TSCH:! did not associate.\n");
return 0;
}
/* Processes and protothreads used by TSCH */
/*---------------------------------------------------------------------------*/
/* Scanning protothread, called by tsch_process:
* Listen to different channels, and when receiving an EB,
* attempt to associate.
*/
PT_THREAD(tsch_scan(struct pt *pt))
{
PT_BEGIN(pt);
static struct input_packet input_eb;
static struct etimer scan_timer;
ASN_INIT(current_asn, 0, 0);
etimer_set(&scan_timer, CLOCK_SECOND / TSCH_ASSOCIATION_POLL_FREQUENCY);
while(!tsch_is_associated && !tsch_is_coordinator) {
/* Hop to any channel offset */
static int current_channel = 0;
/* Time when we started scanning on current_channel */
static clock_time_t current_channel_since = 0;
/* We are not coordinator, try to associate */
rtimer_clock_t t0;
int is_packet_pending = 0;
clock_time_t now_seconds = clock_seconds();
/* Switch to a (new) channel for scanning */
if(current_channel == 0 || now_seconds != current_channel_since) {
/* Pick a channel at random in TSCH_JOIN_HOPPING_SEQUENCE */
uint8_t scan_channel = TSCH_JOIN_HOPPING_SEQUENCE[
random_rand() % sizeof(TSCH_JOIN_HOPPING_SEQUENCE)];
if(current_channel != scan_channel) {
NETSTACK_RADIO.set_value(RADIO_PARAM_CHANNEL, scan_channel);
current_channel = scan_channel;
PRINTF("TSCH: scanning on channel %u\n", scan_channel);
}
current_channel_since = now_seconds;
}
/* Turn radio on and wait for EB */
NETSTACK_RADIO.on();
is_packet_pending = NETSTACK_RADIO.pending_packet();
if(!is_packet_pending && NETSTACK_RADIO.receiving_packet()) {
/* If we are currently receiving a packet, wait until end of reception */
t0 = RTIMER_NOW();
BUSYWAIT_UNTIL_ABS((is_packet_pending = NETSTACK_RADIO.pending_packet()), t0, RTIMER_SECOND / 100);
}
if(is_packet_pending) {
/* Save packet timestamp */
NETSTACK_RADIO.get_object(RADIO_PARAM_LAST_PACKET_TIMESTAMP, &t0, sizeof(rtimer_clock_t));
/* Read packet */
input_eb.len = NETSTACK_RADIO.read(input_eb.payload, TSCH_PACKET_MAX_LEN);
/* Parse EB and attempt to associate */
PRINTF("TSCH: association: received packet (%u bytes) on channel %u\n", input_eb.len, current_channel);
tsch_associate(&input_eb, t0);
}
if(tsch_is_associated) {
/* End of association, turn the radio off */
NETSTACK_RADIO.off();
} else if(!tsch_is_coordinator) {
/* Go back to scanning */
etimer_reset(&scan_timer);
PT_WAIT_UNTIL(pt, etimer_expired(&scan_timer));
}
}
PT_END(pt);
}
/*---------------------------------------------------------------------------*/
/* The main TSCH process */
PROCESS_THREAD(tsch_process, ev, data)
{
static struct pt scan_pt;
PROCESS_BEGIN();
while(1) {
while(!tsch_is_associated) {
if(tsch_is_coordinator) {
/* We are coordinator, start operating now */
tsch_start_coordinator();
} else {
/* Start scanning, will attempt to join when receiving an EB */
PROCESS_PT_SPAWN(&scan_pt, tsch_scan(&scan_pt));
}
}
/* We are part of a TSCH network, start slot operation */
tsch_slot_operation_start();
/* Yield our main process. Slot operation will re-schedule itself
* as long as we are associated */
PROCESS_YIELD_UNTIL(!tsch_is_associated);
/* Will need to re-synchronize */
tsch_reset();
}
PROCESS_END();
}
/*---------------------------------------------------------------------------*/
/* A periodic process to send TSCH Enhanced Beacons (EB) */
PROCESS_THREAD(tsch_send_eb_process, ev, data)
{
static struct etimer eb_timer;
PROCESS_BEGIN();
/* Wait until association */
etimer_set(&eb_timer, CLOCK_SECOND / 10);
while(!tsch_is_associated) {
PROCESS_WAIT_UNTIL(etimer_expired(&eb_timer));
etimer_reset(&eb_timer);
}
/* Set an initial delay except for coordinator, which should send an EB asap */
if(!tsch_is_coordinator) {
etimer_set(&eb_timer, random_rand() % TSCH_EB_PERIOD);
PROCESS_WAIT_UNTIL(etimer_expired(&eb_timer));
}
while(1) {
unsigned long delay;
if(tsch_is_associated && tsch_current_eb_period > 0) {
/* Enqueue EB only if there isn't already one in queue */
if(tsch_queue_packet_count(&tsch_eb_address) == 0) {
int eb_len;
uint8_t hdr_len = 0;
uint8_t tsch_sync_ie_offset;
/* Prepare the EB packet and schedule it to be sent */
packetbuf_clear();
/* We don't use seqno 0 */
if(++tsch_packet_seqno == 0) {
tsch_packet_seqno++;
}
packetbuf_set_attr(PACKETBUF_ATTR_FRAME_TYPE, FRAME802154_BEACONFRAME);
packetbuf_set_attr(PACKETBUF_ATTR_MAC_SEQNO, tsch_packet_seqno);
#if LLSEC802154_ENABLED
if(tsch_is_pan_secured) {
/* Set security level, key id and index */
packetbuf_set_attr(PACKETBUF_ATTR_SECURITY_LEVEL, TSCH_SECURITY_KEY_SEC_LEVEL_EB);
packetbuf_set_attr(PACKETBUF_ATTR_KEY_ID_MODE, FRAME802154_1_BYTE_KEY_ID_MODE); /* Use 1-byte key index */
packetbuf_set_attr(PACKETBUF_ATTR_KEY_INDEX, TSCH_SECURITY_KEY_INDEX_EB);
}
#endif /* LLSEC802154_ENABLED */
eb_len = tsch_packet_create_eb(packetbuf_dataptr(), PACKETBUF_SIZE,
tsch_packet_seqno, &hdr_len, &tsch_sync_ie_offset);
if(eb_len != 0) {
struct tsch_packet *p;
packetbuf_set_datalen(eb_len);
/* Enqueue EB packet */
if(!(p = tsch_queue_add_packet(&tsch_eb_address, NULL, NULL))) {
PRINTF("TSCH:! could not enqueue EB packet\n");
} else {
PRINTF("TSCH: enqueue EB packet %u %u\n", eb_len, hdr_len);
p->tsch_sync_ie_offset = tsch_sync_ie_offset;
p->header_len = hdr_len;
}
}
}
}
if(tsch_current_eb_period > 0) {
/* Next EB transmission with a random delay
* within [tsch_current_eb_period*0.75, tsch_current_eb_period[ */
delay = (tsch_current_eb_period - tsch_current_eb_period / 4)
+ random_rand() % (tsch_current_eb_period / 4);
} else {
delay = TSCH_EB_PERIOD;
}
etimer_set(&eb_timer, delay);
PROCESS_WAIT_UNTIL(etimer_expired(&eb_timer));
}
PROCESS_END();
}
/*---------------------------------------------------------------------------*/
/* A process that is polled from interrupt and calls tx/rx input
* callbacks, outputs pending logs. */
PROCESS_THREAD(tsch_pending_events_process, ev, data)
{
PROCESS_BEGIN();
while(1) {
PROCESS_YIELD_UNTIL(ev == PROCESS_EVENT_POLL);
tsch_rx_process_pending();
tsch_tx_process_pending();
tsch_log_process_pending();
}
PROCESS_END();
}
/* Functions from the Contiki MAC layer driver interface */
/*---------------------------------------------------------------------------*/
static void
tsch_init(void)
{
radio_value_t radio_rx_mode;
radio_value_t radio_tx_mode;
rtimer_clock_t t;
/* Radio Rx mode */
if(NETSTACK_RADIO.get_value(RADIO_PARAM_RX_MODE, &radio_rx_mode) != RADIO_RESULT_OK) {
printf("TSCH:! radio does not support getting RADIO_PARAM_RX_MODE. Abort init.\n");
return;
}
/* Disable radio in frame filtering */
radio_rx_mode &= ~RADIO_RX_MODE_ADDRESS_FILTER;
/* Unset autoack */
radio_rx_mode &= ~RADIO_RX_MODE_AUTOACK;
/* Set radio in poll mode */
radio_rx_mode |= RADIO_RX_MODE_POLL_MODE;
if(NETSTACK_RADIO.set_value(RADIO_PARAM_RX_MODE, radio_rx_mode) != RADIO_RESULT_OK) {
printf("TSCH:! radio does not support setting required RADIO_PARAM_RX_MODE. Abort init.\n");
return;
}
/* Radio Tx mode */
if(NETSTACK_RADIO.get_value(RADIO_PARAM_TX_MODE, &radio_tx_mode) != RADIO_RESULT_OK) {
printf("TSCH:! radio does not support getting RADIO_PARAM_TX_MODE. Abort init.\n");
return;
}
/* Unset CCA */
radio_tx_mode &= ~RADIO_TX_MODE_SEND_ON_CCA;
if(NETSTACK_RADIO.set_value(RADIO_PARAM_TX_MODE, radio_tx_mode) != RADIO_RESULT_OK) {
printf("TSCH:! radio does not support setting required RADIO_PARAM_TX_MODE. Abort init.\n");
return;
}
/* Test setting channel */
if(NETSTACK_RADIO.set_value(RADIO_PARAM_CHANNEL, TSCH_DEFAULT_HOPPING_SEQUENCE[0]) != RADIO_RESULT_OK) {
printf("TSCH:! radio does not support setting channel. Abort init.\n");
return;
}
/* Test getting timestamp */
if(NETSTACK_RADIO.get_object(RADIO_PARAM_LAST_PACKET_TIMESTAMP, &t, sizeof(rtimer_clock_t)) != RADIO_RESULT_OK) {
printf("TSCH:! radio does not support getting last packet timestamp. Abort init.\n");
return;
}
/* Check max hopping sequence length vs default sequence length */
if(TSCH_HOPPING_SEQUENCE_MAX_LEN < sizeof(TSCH_DEFAULT_HOPPING_SEQUENCE)) {
printf("TSCH:! TSCH_HOPPING_SEQUENCE_MAX_LEN < sizeof(TSCH_DEFAULT_HOPPING_SEQUENCE). Abort init.\n");
}
/* Init TSCH sub-modules */
tsch_reset();
tsch_queue_init();
tsch_schedule_init();
tsch_log_init();
ringbufindex_init(&input_ringbuf, TSCH_MAX_INCOMING_PACKETS);
ringbufindex_init(&dequeued_ringbuf, TSCH_DEQUEUED_ARRAY_SIZE);
tsch_is_initialized = 1;
#if TSCH_AUTOSTART
/* Start TSCH operation.
* If TSCH_AUTOSTART is not set, one needs to call NETSTACK_MAC.on() to start TSCH. */
NETSTACK_MAC.on();
#endif /* TSCH_AUTOSTART */
}
/*---------------------------------------------------------------------------*/
/* Function send for TSCH-MAC, puts the packet in packetbuf in the MAC queue */
static void
send_packet(mac_callback_t sent, void *ptr)
{
int ret = MAC_TX_DEFERRED;
int packet_count_before;
int hdr_len = 0;
const linkaddr_t *addr = packetbuf_addr(PACKETBUF_ADDR_RECEIVER);
if(!tsch_is_associated) {
if(!tsch_is_initialized) {
PRINTF("TSCH:! not initialized (see earlier logs), drop outgoing packet\n");
} else {
PRINTF("TSCH:! not associated, drop outgoing packet\n");
}
ret = MAC_TX_ERR;
mac_call_sent_callback(sent, ptr, ret, 1);
return;
}
/* PACKETBUF_ATTR_MAC_SEQNO cannot be zero, due to a pecuilarity
in framer-802154.c. */
if(++tsch_packet_seqno == 0) {
tsch_packet_seqno++;
}
/* Ask for ACK if we are sending anything other than broadcast */
if(!linkaddr_cmp(addr, &linkaddr_null)) {
packetbuf_set_attr(PACKETBUF_ATTR_MAC_ACK, 1);
} else {
/* Broadcast packets shall be added to broadcast queue
* The broadcast address in Contiki is linkaddr_null which is equal
* to tsch_eb_address */
addr = &tsch_broadcast_address;
}
packetbuf_set_attr(PACKETBUF_ATTR_FRAME_TYPE, FRAME802154_DATAFRAME);
packetbuf_set_attr(PACKETBUF_ATTR_MAC_SEQNO, tsch_packet_seqno);
#if LLSEC802154_ENABLED
if(tsch_is_pan_secured) {
/* Set security level, key id and index */
packetbuf_set_attr(PACKETBUF_ATTR_SECURITY_LEVEL, TSCH_SECURITY_KEY_SEC_LEVEL_OTHER);
packetbuf_set_attr(PACKETBUF_ATTR_KEY_ID_MODE, FRAME802154_1_BYTE_KEY_ID_MODE); /* Use 1-byte key index */
packetbuf_set_attr(PACKETBUF_ATTR_KEY_INDEX, TSCH_SECURITY_KEY_INDEX_OTHER);
}
#endif /* LLSEC802154_ENABLED */
packet_count_before = tsch_queue_packet_count(addr);
if((hdr_len = NETSTACK_FRAMER.create()) < 0) {
PRINTF("TSCH:! can't send packet due to framer error\n");
ret = MAC_TX_ERR;
} else {
struct tsch_packet *p;
/* Enqueue packet */
p = tsch_queue_add_packet(addr, sent, ptr);
if(p == NULL) {
PRINTF("TSCH:! can't send packet !tsch_queue_add_packet\n");
ret = MAC_TX_ERR;
} else {
p->header_len = hdr_len;
PRINTF("TSCH: send packet to %u with seqno %u, queue %u %u, len %u %u\n",
TSCH_LOG_ID_FROM_LINKADDR(addr), tsch_packet_seqno,
packet_count_before,
tsch_queue_packet_count(addr),
p->header_len,
queuebuf_datalen(p->qb));
(void)packet_count_before; /* Discard "variable set but unused" warning in case of TSCH_LOG_LEVEL of 0 */
}
}
if(ret != MAC_TX_DEFERRED) {
mac_call_sent_callback(sent, ptr, ret, 1);
}
}
/*---------------------------------------------------------------------------*/
static void
packet_input(void)
{
int frame_parsed = 1;
frame_parsed = NETSTACK_FRAMER.parse();
if(frame_parsed < 0) {
PRINTF("TSCH:! failed to parse %u\n", packetbuf_datalen());
} else {
int duplicate = 0;
/* Seqno of 0xffff means no seqno */
if(packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO) != 0xffff) {
/* Check for duplicate packet by comparing the sequence number
of the incoming packet with the last few ones we saw. */
int i;
for(i = 0; i < MAX_SEQNOS; ++i) {
if(packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO) == received_seqnos[i].seqno &&
linkaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_SENDER),
&received_seqnos[i].sender)) {
/* Drop the packet. */
PRINTF("TSCH:! drop dup ll from %u seqno %u\n",
TSCH_LOG_ID_FROM_LINKADDR(packetbuf_addr(PACKETBUF_ADDR_SENDER)),
packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO));
duplicate = 1;
}
}
if(!duplicate) {
for(i = MAX_SEQNOS - 1; i > 0; --i) {
memcpy(&received_seqnos[i], &received_seqnos[i - 1],
sizeof(struct seqno));
}
received_seqnos[0].seqno = packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO);
linkaddr_copy(&received_seqnos[0].sender,
packetbuf_addr(PACKETBUF_ADDR_SENDER));
}
}
if(!duplicate) {
PRINTF("TSCH: received from %u with seqno %u\n",
TSCH_LOG_ID_FROM_LINKADDR(packetbuf_addr(PACKETBUF_ADDR_SENDER)),
packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO));
NETSTACK_LLSEC.input();
}
}
}
/*---------------------------------------------------------------------------*/
static int
turn_on(void)
{
if(tsch_is_initialized == 1 && tsch_is_started == 0) {
tsch_is_started = 1;
/* Process tx/rx callback and log messages whenever polled */
process_start(&tsch_pending_events_process, NULL);
/* periodically send TSCH EBs */
process_start(&tsch_send_eb_process, NULL);
/* try to associate to a network or start one if setup as coordinator */
process_start(&tsch_process, NULL);
PRINTF("TSCH: starting as %s\n", tsch_is_coordinator ? "coordinator" : "node");
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
static int
turn_off(int keep_radio_on)
{
return 1;
}
/*---------------------------------------------------------------------------*/
static unsigned short
channel_check_interval(void)
{
return 0;
}
/*---------------------------------------------------------------------------*/
const struct mac_driver tschmac_driver = {
"TSCH",
tsch_init,
send_packet,
packet_input,
turn_on,
turn_off,
channel_check_interval,
};
/*---------------------------------------------------------------------------*/
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