6top: refactoring

- untangle 6P message manipulation and the sample schedule function
  - sixtop.c: 6P core part, newly introduced
  - sixtop-6p.c : 6P message manipulation code, based on the former sixtop.c
  - sixtop-sf-simple.c : Sample SF code,based on the former sixtop.c
- maintain a sequence number per neighbor to be used for request
- rename variables and constants
- comply more with draft-ietf-6tisch-6top-protocol-02

core/net/mac/frame802154e-ie.c

@@ -60,7 +60,8 @@ enum ieee802154e_header_ie_id {
 enum ieee802154e_payload_ie_id {
   PAYLOAD_IE_ESDU = 0,
   PAYLOAD_IE_MLME,
-  PAYLOAD_IE_SIXTOP,
+  PAYLOAD_IE_VENDOR,
+  PAYLOAD_IE_IANA_IETF,
   PAYLOAD_IE_LIST_TERMINATION = 0xf,
 };
 
@@ -80,6 +81,10 @@ enum ieee802154e_mlme_long_subie_id {
   MLME_LONG_IE_TSCH_CHANNEL_HOPPING_SEQUENCE = 0x9,
 };
 
+enum ieee802154e_iana_ietf_subie_id {
+  IANA_IETF_IE_6TOP = 0x00,
+};
+
 #define WRITE16(buf, val) \
   do { ((uint8_t *)(buf))[0] = (val) & 0xff; \
        ((uint8_t *)(buf))[1] = ((val) >> 8) & 0xff; } while(0);
@@ -195,12 +200,11 @@ frame80215e_create_ie_payload_list_termination(uint8_t *buf, int len,
 
 /* Payload IE. 6top. Used to nest sub-IEs */
 int
-frame80215e_create_ie_sixtop(uint8_t *buf, int len,
-    struct ieee802154_ies *ies)
+frame80215e_create_ie_iana_ietf(uint8_t *buf, int len, struct ieee802154_ies *ies)
 {
-  int ie_len = 0;
+  int ie_len = ies->sixtop_ie_content_len;
   if(len >= 2 + ie_len && ies != NULL) {
-    create_payload_ie_descriptor(buf, PAYLOAD_IE_SIXTOP, ies->ie_mlme_len);
+    create_payload_ie_descriptor(buf, PAYLOAD_IE_IANA_IETF, ie_len);
     return 2 + ie_len;
   } else {
     return -1;
@@ -544,11 +548,17 @@ frame802154e_parse_information_elements(const uint8_t *buf, uint8_t buf_size,
             len = 0; /* Reset len as we want to read subIEs and not jump over them */
             PRINTF("frame802154e: entering MLME ie with len %u\n", nested_mlme_len);
             break;
-          case PAYLOAD_IE_SIXTOP:
-            PRINTF("frame802154e: entering Sixtop ie with len %u\n", len);
-            /* Sixtop IE detected, return success(0) 
-             * Further parsing of Sixtop IE is carried out at Sixtop layer */
-            return 0;     	            		    
+          case PAYLOAD_IE_IANA_IETF:
+            /* Now expect 'len' bytes of Sixtop sub-IEs */
+            switch(*buf) {
+            case IANA_IETF_IE_6TOP:
+              ies->sixtop_ie_content_ptr = buf + 1;
+              ies->sixtop_ie_content_len = len - 1;
+              break;
+            default:
+              PRINTF("frame802154e: unsupported IANA-IETF sub-IE %u\n", *buf);
+            }
+            break;
           case PAYLOAD_IE_LIST_TERMINATION:
             PRINTF("frame802154e: payload ie list termination %u\n", len);
             return (len == 0) ? buf + len - start : -1;

core/net/mac/frame802154e-ie.h

@@ -45,7 +45,6 @@
 #include "net/mac/tsch/tsch-private.h"
 
 #define FRAME802154E_IE_MAX_LINKS       4
-#define SIXTOP_IE_MAX_LINKS             3
 
 /* Structures used for the Slotframe and Links information element */
 struct tsch_slotframe_and_links_link {
@@ -61,23 +60,6 @@ struct tsch_slotframe_and_links {
   struct tsch_slotframe_and_links_link links[FRAME802154E_IE_MAX_LINKS];
 };
 
-/* Structures used for the Sixtop information element */
-struct sixtop_link {
-  uint16_t timeslot;
-  uint16_t channel_offset;
-  uint8_t link_option;
-};
-struct sixtop {
-  /* Sixtop IEs */
-  uint8_t subIE_id;
-  uint8_t version_code;
-  uint8_t schedule_fn_id;
-  struct sixtop_link linkList[SIXTOP_IE_MAX_LINKS];
-  /* Link Request IE */
-  uint8_t num_links;
-  uint8_t frame_id;
-};
-
 /* The information elements that we currently support */
 struct ieee802154_ies {
   /* Header IEs */
@@ -99,7 +81,8 @@ struct ieee802154_ies {
   uint16_t ie_hopping_sequence_len;
   uint8_t ie_hopping_sequence_list[TSCH_HOPPING_SEQUENCE_MAX_LEN];
   /* Payload Sixtop IE */
-  struct sixtop ie_sixtop;
+  const uint8_t *sixtop_ie_content_ptr;
+  uint16_t sixtop_ie_content_len;
 };
 
 /** Insert various Information Elements **/
@@ -118,7 +101,7 @@ int frame80215e_create_ie_header_list_termination_2(uint8_t *buf, int len,
 int frame80215e_create_ie_payload_list_termination(uint8_t *buf, int len,
     struct ieee802154_ies *ies);
 /* Payload IE. 6top. Used to nest sub-IEs */
-int frame80215e_create_ie_sixtop(uint8_t *buf, int len,
+int frame80215e_create_ie_iana_ietf(uint8_t *buf, int len,
     struct ieee802154_ies *ies);
 /* Payload IE. MLME. Used to nest sub-IEs */
 int frame80215e_create_ie_mlme(uint8_t *buf, int len,

core/net/mac/framer-802154.c

@@ -97,6 +97,9 @@ create_frame(int type, int do_create)
    * source nor destination address, we have dest PAN ID iff compression is *set*. */
   params.fcf.panid_compression = 0;
 
+  /* Set IE Present bit */
+  params.fcf.ie_list_present = packetbuf_attr(PACKETBUF_ATTR_MAC_METADATA);
+
   /* Insert IEEE 802.15.4 version bits. */
   params.fcf.frame_version = FRAME802154_VERSION;