/* * 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 * Beshr Al Nahas * */ #include "contiki.h" #include "dev/radio.h" #include "net/netstack.h" #include "net/packetbuf.h" #include "net/queuebuf.h" #include "net/nbr-table.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 "net/mac/mac-sequence.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/net-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 #if NETSTACK_CONF_WITH_IPV6 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 /* NETSTACK_CONF_WITH_IPV6 */ #endif /* TSCH_LINK_NEIGHBOR_CALLBACK */ /* 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 unicast data frames only */ static uint8_t tsch_packet_seqno = 0; /* Current period for EB output */ static clock_time_t tsch_current_eb_period; /* Current period for keepalive output */ static clock_time_t tsch_current_ka_timeout; /* 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_ka_timeout(uint32_t timeout) { tsch_current_ka_timeout = timeout; } /*---------------------------------------------------------------------------*/ void tsch_set_eb_period(uint32_t period) { tsch_current_eb_period = MIN(period, TSCH_MAX_EB_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_current_ka_timeout*0.9, tsch_current_ka_timeout[ */ if(!tsch_is_coordinator && tsch_is_associated && tsch_current_ka_timeout > 0) { unsigned long delay = (tsch_current_ka_timeout - tsch_current_ka_timeout / 10) + random_rand() % (tsch_current_ka_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, (linkaddr_t *)&frame.src_addr); if(stat == NULL) { stat = (struct eb_stat *)nbr_table_add_lladdr(eb_stats, (linkaddr_t *)&frame.src_addr, NBR_TABLE_REASON_MAC, NULL); } if(stat != NULL) { stat->rx_count++; stat->jp = eb_ies.ie_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); packetbuf_set_attr(PACKETBUF_ATTR_CHANNEL, current_input->channel); } /* 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(), ¤t_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, ¤t_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); /* Set PANID */ frame802154_set_pan_id(frame.src_pid); /* Synchronize on EB */ tsch_slot_operation_sync(timestamp - tsch_timing[tsch_ts_tx_offset], ¤t_asn); /* Update global flags */ tsch_is_associated = 1; tsch_is_pan_secured = frame.fcf.security_enabled; /* Start sending keep-alives now that tsch_is_associated is set */ tsch_schedule_keepalive(); #ifdef TSCH_CALLBACK_JOINING_NETWORK TSCH_CALLBACK_JOINING_NETWORK(); #endif 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; /* Time when we started scanning on current_channel */ static clock_time_t current_channel_since; ASN_INIT(current_asn, 0, 0); etimer_set(&scan_timer, CLOCK_SECOND / TSCH_ASSOCIATION_POLL_FREQUENCY); current_channel_since = clock_time(); while(!tsch_is_associated && !tsch_is_coordinator) { /* Hop to any channel offset */ static uint8_t current_channel = 0; /* We are not coordinator, try to associate */ rtimer_clock_t t0; int is_packet_pending = 0; clock_time_t now_time = clock_time(); /* Switch to a (new) channel for scanning */ if(current_channel == 0 || now_time - current_channel_since > TSCH_CHANNEL_SCAN_DURATION) { /* 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_time; } /* 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) { /* Read packet */ input_eb.len = NETSTACK_RADIO.read(input_eb.payload, TSCH_PACKET_MAX_LEN); /* Save packet timestamp */ NETSTACK_RADIO.get_object(RADIO_PARAM_LAST_PACKET_TIMESTAMP, &t0, sizeof(rtimer_clock_t)); /* 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(); packetbuf_set_attr(PACKETBUF_ATTR_FRAME_TYPE, FRAME802154_BEACONFRAME); #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, &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; } /* Ask for ACK if we are sending anything other than broadcast */ if(!linkaddr_cmp(addr, &linkaddr_null)) { /* PACKETBUF_ATTR_MAC_SEQNO cannot be zero, due to a pecuilarity in framer-802154.c. */ if(++tsch_packet_seqno == 0) { tsch_packet_seqno++; } packetbuf_set_attr(PACKETBUF_ATTR_MAC_SEQNO, tsch_packet_seqno); 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); #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 !NETSTACK_CONF_BRIDGE_MODE /* * In the Contiki stack, the source address of a frame is set at the RDC * layer. Since TSCH doesn't use any RDC protocol and bypasses the layer to * transmit a frame, it should set the source address by itself. */ packetbuf_set_addr(PACKETBUF_ADDR_SENDER, &linkaddr_node_addr); #endif 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 to %u with seqno %u, queue %u %u\n", TSCH_LOG_ID_FROM_LINKADDR(addr), tsch_packet_seqno, packet_count_before, tsch_queue_packet_count(addr)); 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 duplicates */ duplicate = mac_sequence_is_duplicate(); if(duplicate) { /* 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)); } else { mac_sequence_register_seqno(); } } 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) { if(keep_radio_on) { NETSTACK_RADIO.on(); } else { NETSTACK_RADIO.off(); } 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, }; /*---------------------------------------------------------------------------*/