added Wi-SUN neighbor table management to Wi-SUN

check if ARO registrations are allowed
Cleans neighbors that are not concerned valid if there is no room for new neighbour
Defined temporary entry count and RPL parent set size child count is currently set to 22

Added RPL function to set if address is our parent
Added neighbor table function to check if neighbor has valid ARO registration

Author: Mika Tervonen

source/6LoWPAN/ND/nd_router_object.c

@@ -923,6 +923,12 @@ bool nd_ns_aro_handler(protocol_interface_info_entry_t *cur_interface, const uin
     }
 
     /* TODO - check hard upper limit on registrations? */
+    if (ws_info(cur_interface) &&
+            !ws_common_allow_child_registration(cur_interface)) {
+        aro_out->present = true;
+        aro_out->status = ARO_FULL;
+        return true;
+    }
 
     /* We need to have entry in the Neighbour Cache */
     ipv6_neighbour_t *neigh = ipv6_neighbour_lookup_or_create(&cur_interface->ipv6_neighbour_cache, src_addr);

source/6LoWPAN/ws/ws_bootstrap.c

@@ -1169,6 +1169,49 @@ static void ws_bootstrap_asynch_confirm(struct protocol_interface_info_entry *in
     (void)interface;
     (void)asynch_message;
 }
+static void ws_bootstrap_neighbor_table_clean(struct protocol_interface_info_entry *interface)
+{
+    uint8_t ll_target[16];
+
+    if (mac_neighbor_info(interface)->neighbour_list_size <= mac_neighbor_info(interface)->list_total_size - WS_NON_CHILD_NEIGHBOUR_COUNT ) {
+        // Enough neighbor entries
+        return;
+    }
+    memcpy(ll_target, ADDR_LINK_LOCAL_PREFIX, 8);
+
+    mac_neighbor_table_entry_t *neighbor_entry_ptr = NULL;
+    ns_list_foreach_safe(mac_neighbor_table_entry_t, cur, &mac_neighbor_info(interface)->neighbour_list) {
+
+        if (cur->link_role == PRIORITY_PARENT_NEIGHBOUR) {
+            //This is our primary parent we cannot delete
+            continue;
+        }
+
+        if (neighbor_entry_ptr && neighbor_entry_ptr->lifetime < cur->lifetime) {
+            // We have already shorter link entry found this cannot replace it
+            continue;
+        }
+
+        if (ipv6_neighbour_has_registered_by_eui64(&interface->ipv6_neighbour_cache, cur->mac64)) {
+            // We have registered entry so we have been selected as parent
+            continue;
+        }
+
+        memcpy(ll_target + 8, cur->mac64, 8);
+        ll_target[8] ^= 2;
+
+        if (rpl_control_is_dodag_parent(interface, ll_target)) {
+            // Possible parent is limited to 3 by default?
+            continue;
+        }
+        neighbor_entry_ptr = cur;
+    }
+    if (neighbor_entry_ptr) {
+        tr_info("dropped oldest neighbour %s", trace_array(neighbor_entry_ptr->mac64, 8));
+        mac_neighbor_table_neighbor_remove(mac_neighbor_info(interface), neighbor_entry_ptr);
+    }
+
+}
 
 static bool ws_bootstrap_neighbor_info_request(struct protocol_interface_info_entry *interface, const uint8_t *mac_64, llc_neighbour_req_t *neighbor_buffer, bool request_new)
 {
@@ -1183,6 +1226,7 @@ static bool ws_bootstrap_neighbor_info_request(struct protocol_interface_info_en
     if (!request_new) {
         return false;
     }
+    ws_bootstrap_neighbor_table_clean(interface);
 
     neighbor_buffer->neighbor = ws_bootstrap_mac_neighbor_add(interface, mac_64);
 

source/6LoWPAN/ws/ws_common.c

@@ -23,6 +23,7 @@
 #include <ns_list.h>
 #include <nsdynmemLIB.h>
 #include "NWK_INTERFACE/Include/protocol.h"
+#include "6LoWPAN/ws/ws_config.h"
 #include "6LoWPAN/ws/ws_common_defines.h"
 #include "6LoWPAN/ws/ws_common.h"
 #include "6LoWPAN/ws/ws_bootstrap.h"
@@ -201,6 +202,23 @@ void ws_common_neighbor_update(protocol_interface_info_entry_t *cur, const uint8
     }
 }
 
+bool ws_common_allow_child_registration(protocol_interface_info_entry_t *interface)
+{
+    uint8_t child_count = 0;
+    ns_list_foreach_safe(mac_neighbor_table_entry_t, cur, &mac_neighbor_info(interface)->neighbour_list) {
+
+        if (ipv6_neighbour_has_registered_by_eui64(&interface->ipv6_neighbour_cache, cur->mac64)) {
+            child_count++;
+            if (child_count > (mac_neighbor_info(interface)->list_total_size - WS_NON_CHILD_NEIGHBOUR_COUNT)) {
+                tr_warn("Child registration not allowed %d/%d, max:%d", child_count, (mac_neighbor_info(interface)->list_total_size - WS_NON_CHILD_NEIGHBOUR_COUNT), mac_neighbor_info(interface)->list_total_size);
+                return false;
+            }
+        }
+    }
+    tr_info("Child registration allowed %d/%d, max:%d", child_count, (mac_neighbor_info(interface)->list_total_size - WS_NON_CHILD_NEIGHBOUR_COUNT), mac_neighbor_info(interface)->list_total_size);
+    return true;
+}
+
 
 #endif // HAVE_WS
 

source/6LoWPAN/ws/ws_common.h

@@ -106,12 +106,15 @@ void ws_common_fast_timer(protocol_interface_info_entry_t *cur, uint16_t ticks);
 
 void ws_common_neighbor_update(protocol_interface_info_entry_t *cur, const uint8_t *ll_address);
 
+bool ws_common_allow_child_registration(protocol_interface_info_entry_t *cur);
+
 #define ws_info(cur) ((cur)->ws_info)
 #else
 #define ws_info(cur) ((ws_info_t *) NULL)
 #define ws_common_seconds_timer(cur, seconds)
 #define ws_common_neighbor_update(cur, ll_address) ((void) 0)
 #define ws_common_fast_timer(cur, ticks) ((void) 0)
+#define ws_common_allow_child_registration(cur) (false)
 
 
 #endif //HAVE_WS

source/6LoWPAN/ws/ws_config.h

@@ -99,4 +99,14 @@ extern int8_t DEVICE_MIN_SENS;
 #define WS_DHCP_SOLICIT_MAX_RC          0
 
 
+/* Neighbour table configuration
+ *
+ * Amount of RPL candidate parents
+ * Amount of ND reply entries left
+ * rest are used as child count, but is related to neighbour table size
+ */
+#define WS_RPL_CANDIDATE_PARENT_COUNT 3 // Largest possible value
+#define WS_TEMPORARY_NEIGHBOUR_ENTRIES 7
+#define WS_NON_CHILD_NEIGHBOUR_COUNT (WS_RPL_CANDIDATE_PARENT_COUNT + WS_TEMPORARY_NEIGHBOUR_ENTRIES)
+
 #endif /* WS_CONFIG_H_ */

source/RPL/rpl_control.c

@@ -227,6 +227,17 @@ void rpl_control_address_register_done(struct buffer *buf, uint8_t status)
     }
 }
 
+bool rpl_control_is_dodag_parent(protocol_interface_info_entry_t *interface, const uint8_t ll_addr[16])
+{
+    // go through instances and parents and check if they match the address.
+    ns_list_foreach(struct rpl_instance, instance, &interface->rpl_domain->instances) {
+        if (rpl_instance_address_is_parent(instance, ll_addr)){
+            return true;
+        }
+    }
+    return false;
+}
+
 /* Address changes need to trigger DAO target re-evaluation */
 static void rpl_control_addr_notifier(struct protocol_interface_info_entry *interface, const if_address_entry_t *addr, if_address_callback_t reason)
 {

source/RPL/rpl_control.h

@@ -148,6 +148,7 @@ void rpl_control_publish_host_address(rpl_domain_t *domain, const uint8_t addr[1
 void rpl_control_unpublish_address(rpl_domain_t *domain, const uint8_t addr[16]);
 void rpl_control_register_address(struct protocol_interface_info_entry *interface, if_address_entry_t *addr);
 void rpl_control_address_register_done(struct buffer *buf, uint8_t status);
+bool rpl_control_is_dodag_parent(struct protocol_interface_info_entry *interface, const uint8_t ll_addr[16]);
 
 /* Configure and return the routing lookup predicate for a specified RPL instance ID */
 ipv6_route_predicate_fn_t *rpl_control_get_route_predicate(rpl_domain_t *domain, uint8_t instance_id, const uint8_t src[16], const uint8_t dst[16]);

source/RPL/rpl_upward.c

@@ -1564,6 +1564,20 @@ uint16_t rpl_instance_current_rank(const rpl_instance_t *instance)
     return instance->current_rank;
 }
 
+bool rpl_instance_address_is_parent(rpl_instance_t *instance, const uint8_t *ipv6_addr)
+{
+    ns_list_foreach(rpl_neighbour_t, neighbour, &instance->candidate_neighbours) {
+        if (neighbour->dodag_parent && addr_ipv6_equal(neighbour->ll_address, ipv6_addr)) {
+            return true;
+        }
+        if (!neighbour->dodag_parent) {
+            // list is ordered so first encounter of false means no more parents in list
+            return false;
+        }
+    }
+    return false;
+}
+
 void rpl_instance_slow_timer(rpl_instance_t *instance, uint16_t seconds)
 {
     ns_list_foreach(rpl_dodag_t, dodag, &instance->dodags) {

source/RPL/rpl_upward.h

@@ -83,6 +83,7 @@ void rpl_instance_dio_trigger(rpl_instance_t *instance, struct protocol_interfac
 void rpl_instance_set_local_repair(rpl_instance_t *instance, bool repair);
 bool rpl_instance_local_repair(const rpl_instance_t *instance);
 uint16_t rpl_instance_current_rank(const rpl_instance_t *instance);
+bool rpl_instance_address_is_parent(rpl_instance_t *instance, const uint8_t *ipv6_addr);
 void rpl_instance_slow_timer(rpl_instance_t *instance, uint16_t seconds);
 
 rpl_dodag_t *rpl_lookup_dodag(const rpl_instance_t *instance, const uint8_t *dodagid);

source/ipv6_stack/ipv6_routing_table.c

@@ -410,6 +410,16 @@ void ipv6_neighbour_delete_registered_by_eui64(ipv6_neighbour_cache_t *cache, co
     }
 }
 
+bool ipv6_neighbour_has_registered_by_eui64(ipv6_neighbour_cache_t *cache, const uint8_t *eui64)
+{
+    ns_list_foreach_safe(ipv6_neighbour_t, cur, &cache->list) {
+        if (cur->type != IP_NEIGHBOUR_GARBAGE_COLLECTIBLE && memcmp(ipv6_neighbour_eui64(cache, cur), eui64, 8) == 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
 void ipv6_neighbour_set_state(ipv6_neighbour_cache_t *cache, ipv6_neighbour_t *entry, ip_neighbour_cache_state_t state)
 {
     if (!ipv6_neighbour_state_is_probably_reachable(entry->state) &&

source/ipv6_stack/ipv6_routing_table.h

@@ -160,6 +160,7 @@ extern bool ipv6_neighbour_addr_is_probably_reachable(ipv6_neighbour_cache_t *ca
 extern bool ipv6_neighbour_ll_addr_match(const ipv6_neighbour_t *entry, addrtype_t ll_type, const uint8_t *ll_address);
 extern void ipv6_neighbour_invalidate_ll_addr(ipv6_neighbour_cache_t *cache, addrtype_t ll_type, const uint8_t *ll_address);
 extern void ipv6_neighbour_delete_registered_by_eui64(ipv6_neighbour_cache_t *cache, const uint8_t *eui64);
+extern bool ipv6_neighbour_has_registered_by_eui64(ipv6_neighbour_cache_t *cache, const uint8_t *eui64);
 extern void ipv6_neighbour_entry_update_unsolicited(ipv6_neighbour_cache_t *cache, ipv6_neighbour_t *entry, addrtype_t type, const uint8_t *ll_address/*, bool tentative*/);
 extern ipv6_neighbour_t *ipv6_neighbour_update_unsolicited(ipv6_neighbour_cache_t *cache, const uint8_t *ip_address, addrtype_t ll_type, const uint8_t *ll_address);
 extern void ipv6_neighbour_reachability_confirmation(const uint8_t ip_address[__static 16], int8_t interface_id);

test/nanostack/unittest/6LoWPAN/nd_router_object/Makefile

@@ -29,6 +29,7 @@ TEST_SRC_FILES = \
         ../../stub/protocol_core_stub.c \
         ../../stub/protocol_6lowpan_stub.c \
         ../../stub/whiteboard_stub.c \
+        ../../stub/ws_common_stub.c \
         ../../stub/lowpan_context_stub.c \
         ../../stub/rpl_control_stub.c \
         ../../stub/rpl_data_stub.c \

test/nanostack/unittest/stub/rpl_upward_stub.c

@@ -418,6 +418,11 @@ uint16_t rpl_instance_current_rank(const rpl_instance_t *instance)
     return 0;
 }
 
+bool rpl_instance_address_is_parent(rpl_instance_t *instance, const uint8_t *ipv6_addr)
+{
+    return false;
+}
+
 void rpl_instance_slow_timer(rpl_instance_t *instance, uint16_t seconds)
 {
 }

test/nanostack/unittest/stub/ws_common_stub.c

@@ -55,3 +55,9 @@ void ws_common_neighbor_update(protocol_interface_info_entry_t *cur, const uint8
     (void) cur;
     (void) ll_address;
 }
+bool ws_common_allow_child_registration(protocol_interface_info_entry_t *interface)
+{
+    (void) interface;
+    return true;
+}
+