omit NA messages from NS

Added configuration boolean to omit NA answers to NS messages
Consider MAC level ACK as success for NS
Configured Wi-SUN to use this feature

Author: Mika Tervonen

source/6LoWPAN/ws/ws_bootstrap.c

@@ -693,7 +693,9 @@ static int8_t ws_bootstrap_up(protocol_interface_info_entry_t *cur)
     /* Disable SLLAO send/mandatory receive with the ARO */
     cur->ipv6_neighbour_cache.use_eui64_as_slla_in_aro = true;
     /* Omit sending of NA if ARO SUCCESS */
-    cur->ipv6_neighbour_cache.omit_aro_success = true;
+    cur->ipv6_neighbour_cache.omit_na_aro_success = true;
+    /* Omit sending of NA and consider ACK to be success */
+    cur->ipv6_neighbour_cache.omit_na = true;
     // do not process AROs from NA. This is overriden by Wi-SUN specific failure handling
     cur->ipv6_neighbour_cache.recv_na_aro = false;
     /* Disable NUD Probes */

source/Common_Protocols/icmpv6.c

@@ -1320,6 +1320,40 @@ uint8_t *icmpv6_write_mtu_option(uint32_t mtu, uint8_t *dptr)
     return dptr;
 }
 
+void ack_receive_cb(struct buffer *buffer_ptr, uint8_t status)
+{
+    /*icmpv6_na_handler functionality based on ACK*/
+    ipv6_neighbour_t *neighbour_entry;
+    uint8_t ll_target[16];
+
+    if (status != SOCKET_TX_DONE) {
+        /*NS failed*/
+        return;
+    }
+
+    if (buffer_ptr->dst_sa.addr_type == ADDR_IPV6) {
+        /*Full IPv6 address*/
+        memcpy(ll_target, buffer_ptr->dst_sa.address, 16);
+    } else if (buffer_ptr->dst_sa.addr_type == ADDR_802_15_4_LONG) {
+        // Build link local address from long MAC address
+        memcpy(ll_target, ADDR_LINK_LOCAL_PREFIX, 8);
+        memcpy(ll_target + 8, &buffer_ptr->dst_sa.address[2], 8);
+        ll_target[8] ^= 2;
+    } else {
+        tr_warn("wrong address %d %s", buffer_ptr->dst_sa.addr_type, trace_array(buffer_ptr->dst_sa.address, 16));
+        return;
+    }
+
+    neighbour_entry = ipv6_neighbour_lookup(&buffer_ptr->interface->ipv6_neighbour_cache, ll_target);
+    if (neighbour_entry) {
+        ipv6_neighbour_update_from_na(&buffer_ptr->interface->ipv6_neighbour_cache, neighbour_entry, NA_S, buffer_ptr->dst_sa.addr_type, buffer_ptr->dst_sa.address);
+    }
+
+    if (ws_info(buffer_ptr->interface)) {
+        ws_common_neighbor_update(buffer_ptr->interface, ll_target);
+    }
+}
+
 buffer_t *icmpv6_build_ns(protocol_interface_info_entry_t *cur, const uint8_t target_addr[16], const uint8_t *prompting_src_addr, bool unicast, bool unspecified_source, const aro_t *aro)
 {
     if (!cur || addr_is_ipv6_multicast(target_addr)) {
@@ -1394,10 +1428,15 @@ buffer_t *icmpv6_build_ns(protocol_interface_info_entry_t *cur, const uint8_t ta
         }
         /* If ARO Success sending is omitted, MAC ACK is used instead */
         /* Setting callback for receiving ACK from adaptation layer */
-        if (aro && cur->ipv6_neighbour_cache.omit_aro_success) {
+        if (aro && cur->ipv6_neighbour_cache.omit_na_aro_success) {
             buf->ack_receive_cb = rpl_control_address_register_done;
         }
     }
+    if (!aro && cur->ipv6_neighbour_cache.omit_na) {
+        /*MAC ACK is processed as success response*/
+        buf->ack_receive_cb = ack_receive_cb;
+    }
+
     buf->src_sa.addr_type = ADDR_IPV6;
 
     /* NS packets are implicitly on-link. If we ever find ourselves sending an
@@ -1530,11 +1569,16 @@ buffer_t *icmpv6_build_na(protocol_interface_info_entry_t *cur, bool solicited,
 
     tr_debug("Build NA");
 
-    /* Check if ARO status == success, then sending can be omitted with flag */
-    if (aro && cur->ipv6_neighbour_cache.omit_aro_success && aro->status == ARO_SUCCESS) {
-        tr_debug("Omit success reply");
+    /* Check if ARO response and status == success, then sending can be omitted with flag */
+    if (aro && cur->ipv6_neighbour_cache.omit_na_aro_success && aro->status == ARO_SUCCESS) {
+        tr_debug("Omit NA ARO success");
         return NULL;
     }
+    /* All other than ARO NA messages are omitted and MAC ACK is considered as success */
+    if (!aro && cur->ipv6_neighbour_cache.omit_na) {
+        return NULL;
+    }
+
 
     buffer_t *buf = buffer_get(8 + 16 + 16 + 16); /* fixed, target addr, target ll addr, aro */
     if (!buf) {

source/ipv6_stack/ipv6_routing_table.h

@@ -123,7 +123,8 @@ typedef struct ipv6_neighbour_cache {
     bool                                    recv_ns_aro : 1;
     bool                                    recv_na_aro : 1;
     bool                                    use_eui64_as_slla_in_aro : 1;
-    bool                                    omit_aro_success : 1;
+    bool                                    omit_na_aro_success : 1;
+    bool                                    omit_na : 1; // except for ARO successes which have a separate flag
     int8_t                                  interface_id;
     uint8_t                                 max_ll_len;
     uint8_t                                 gc_timer;