Wi-SUN Border router uses Static address as DODAGID

If border router is configured with static backbone prefix
address generated for that prefix is used as RPL DODAGID

Author: Mika Tervonen

source/6LoWPAN/ws/ws_bbr_api.c

@@ -366,30 +366,11 @@ static void ws_bbr_slaac_remove(protocol_interface_info_entry_t *cur, uint8_t *u
     addr_policy_table_delete_entry(ula_prefix, 64);
 }
 
-
-static int ws_bbr_static_dodagid_create(protocol_interface_info_entry_t *cur)
-{
-    if (memcmp(current_dodag_id, ADDR_UNSPECIFIED, 16) != 0) {
-        // address generated
-        return 0;
-    }
-    // This address is only used if no other address available.
-    if_address_entry_t *add_entry = ws_bbr_slaac_generate(cur, static_dodag_id_prefix);
-    if (!add_entry) {
-        tr_err("dodagid create failed");
-        return -1;
-    }
-    memcpy(current_dodag_id, add_entry->address, 16);
-    tr_info("BBR generate DODAGID %s", trace_ipv6(current_dodag_id));
-
-    return 0;
-}
-
 /*
  * 0 static non rooted self generated own address
  * 1 static address with backbone connectivity
  */
-static void ws_bbr_bb_static_prefix_get(uint8_t *dodag_id_ptr)
+static uint8_t *ws_bbr_bb_static_prefix_get(uint8_t *dodag_id_ptr)
 {
 
     /* Get static ULA prefix if we have configuration in backbone and there is address we use that.
@@ -400,14 +381,46 @@ static void ws_bbr_bb_static_prefix_get(uint8_t *dodag_id_ptr)
     protocol_interface_info_entry_t *bb_interface = protocol_stack_interface_info_get_by_id(backbone_interface_id);
 
     if (bb_interface && bb_interface->ipv6_configure->ipv6_stack_mode == NET_IPV6_BOOTSTRAP_STATIC) {
-        if (protocol_address_prefix_cmp(bb_interface, bb_interface->ipv6_configure->static_prefix64, 64)) {
-            memcpy(dodag_id_ptr, bb_interface->ipv6_configure->static_prefix64, 8);
+        ns_list_foreach(if_address_entry_t, addr, &bb_interface->ip_addresses) {
+            if (bitsequal(addr->address, bb_interface->ipv6_configure->static_prefix64, 64)) {
+                // static address available in interface copy the prefix and return the address
+                if (dodag_id_ptr) {
+                    memcpy(dodag_id_ptr, bb_interface->ipv6_configure->static_prefix64, 8);
+                }
+                return addr->address;
+            }
         }
     }
-    return;
+    return NULL;
 }
 
 
+static int ws_bbr_static_dodagid_create(protocol_interface_info_entry_t *cur)
+{
+    if (memcmp(current_dodag_id, ADDR_UNSPECIFIED, 16) != 0) {
+        // address generated
+        return 0;
+    }
+
+    uint8_t *static_address_ptr = ws_bbr_bb_static_prefix_get(NULL);
+    if (static_address_ptr) {
+        memcpy(current_dodag_id, static_address_ptr, 16);
+        tr_info("BBR Static DODAGID %s", trace_ipv6(current_dodag_id));
+        return 0;
+    }
+
+    // This address is only used if no other address available.
+    if_address_entry_t *add_entry = ws_bbr_slaac_generate(cur, static_dodag_id_prefix);
+    if (!add_entry) {
+        tr_err("dodagid create failed");
+        return -1;
+    }
+    memcpy(current_dodag_id, add_entry->address, 16);
+    tr_info("BBR generate DODAGID %s", trace_ipv6(current_dodag_id));
+
+    return 0;
+}
+
 static void ws_bbr_dodag_get(uint8_t *local_prefix_ptr, uint8_t *global_prefix_ptr)
 {
     uint8_t global_address[16];