TSCH: use sequence number only for unicast data frames

core/net/mac/framer-802154.c

@@ -86,14 +86,16 @@ create_frame(int type, int do_create)
   params.fcf.frame_pending = packetbuf_attr(PACKETBUF_ATTR_PENDING);
   if(packetbuf_holds_broadcast()) {
     params.fcf.ack_required = 0;
+    /* Suppress seqno on broadcast if supported (frame v2 or more) */
+    params.fcf.sequence_number_suppression = FRAME802154_VERSION >= FRAME802154_IEEE802154E_2012;
   } else {
     params.fcf.ack_required = packetbuf_attr(PACKETBUF_ATTR_MAC_ACK);
+    params.fcf.sequence_number_suppression = FRAME802154_SUPPR_SEQNO;
   }
   /* We do not compress PAN ID in outgoing frames, i.e. include one PAN ID (dest by default)
    * There is one exception, seemingly a typo in Table 2a: rows 2 and 3: when there is no
    * source nor destination address, we have dest PAN ID iff compression is *set*. */
   params.fcf.panid_compression = 0;
-  params.fcf.sequence_number_suppression = FRAME802154_SUPPR_SEQNO;
 
   /* Insert IEEE 802.15.4 version bits. */
   params.fcf.frame_version = FRAME802154_VERSION;

core/net/mac/tsch/tsch-packet.c

@@ -189,7 +189,7 @@ tsch_packet_parse_eack(const uint8_t *buf, int buf_size,
 /*---------------------------------------------------------------------------*/
 /* Create an EB packet */
 int
-tsch_packet_create_eb(uint8_t *buf, int buf_size, uint8_t seqno,
+tsch_packet_create_eb(uint8_t *buf, int buf_size,
     uint8_t *hdr_len, uint8_t *tsch_sync_ie_offset)
 {
   int ret = 0;
@@ -210,8 +210,7 @@ tsch_packet_create_eb(uint8_t *buf, int buf_size, uint8_t seqno,
   p.fcf.frame_version = FRAME802154_IEEE802154E_2012;
   p.fcf.src_addr_mode = FRAME802154_LONGADDRMODE;
   p.fcf.dest_addr_mode = FRAME802154_SHORTADDRMODE;
-  p.seq = seqno;
+  p.fcf.sequence_number_suppression = 1;
-  p.fcf.sequence_number_suppression = FRAME802154_SUPPR_SEQNO;
   /* It is important not to compress PAN ID, as this would result in not including either
    * source nor destination PAN ID, leaving potential joining devices unaware of the PAN ID. */
   p.fcf.panid_compression = 0;

core/net/mac/tsch/tsch-packet.h

@@ -94,7 +94,7 @@ int tsch_packet_parse_eack(const uint8_t *buf, int buf_size,
     uint8_t seqno, frame802154_t *frame, struct ieee802154_ies *ies, uint8_t *hdr_len);
 /* Create an EB packet */
 int tsch_packet_create_eb(uint8_t *buf, int buf_size,
-    uint8_t seqno, uint8_t *hdr_len, uint8_t *tsch_sync_ie_ptr);
+    uint8_t *hdr_len, uint8_t *tsch_sync_ie_ptr);
 /* Update ASN in EB packet */
 int tsch_packet_update_eb(uint8_t *buf, int buf_size, uint8_t tsch_sync_ie_offset);
 /* Parse EB and extract ASN and join priority */

core/net/mac/tsch/tsch.c

@@ -134,7 +134,7 @@ 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 */
+/* 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;
@@ -728,12 +728,7 @@ PROCESS_THREAD(tsch_send_eb_process, ev, data)
         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 */
@@ -743,7 +738,7 @@ PROCESS_THREAD(tsch_send_eb_process, ev, data)
         }
 #endif /* LLSEC802154_ENABLED */
         eb_len = tsch_packet_create_eb(packetbuf_dataptr(), PACKETBUF_SIZE,
-            tsch_packet_seqno, &hdr_len, &tsch_sync_ie_offset);
+            &hdr_len, &tsch_sync_ie_offset);
         if(eb_len != 0) {
           struct tsch_packet *p;
           packetbuf_set_datalen(eb_len);
@@ -876,14 +871,14 @@ send_packet(mac_callback_t sent, void *ptr)
     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);
-  /* 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
@@ -893,7 +888,6 @@ send_packet(mac_callback_t sent, void *ptr)
   }
 
   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) {
@@ -949,7 +943,6 @@ packet_input(void)
       /* Check for duplicates */
       duplicate = mac_sequence_is_duplicate();
       if(duplicate) {
-        extern clock_time_t duplicate_age;
         /* Drop the packet. */
         PRINTF("TSCH:! drop dup ll from %u seqno %u\n",
                TSCH_LOG_ID_FROM_LINKADDR(packetbuf_addr(PACKETBUF_ADDR_SENDER)),