RPL parent candidate list update

Added new API for RPL to ask instance candidate list sizeand size.

Added API for remove worst parent candidate from list if user detect too much usage for replace.

Replaced candidate must be proped or otherwise new candidate is dropped.

Extend Objection function point for validate is new candidate enough good for add.

WS_RPL_MIN_HOP_RANK_INCREASE from 196 to 160. This will reduce a case that device is not switching too aggressive to 1 hop shorter parent.

Update Worts candidate select function for compare path cost and smarter dio age definition.

Change-Id: I67150ab4eae96c90fbded9ff1a9c9084bdf97eae

Author: Juha Heiskanen

source/6LoWPAN/ws/ws_bootstrap.c

@@ -97,7 +97,6 @@ static void ws_bootstrap_pan_version_increment(protocol_interface_info_entry_t *
 static ws_nud_table_entry_t *ws_nud_entry_discover(protocol_interface_info_entry_t *cur, void *neighbor);
 static void ws_nud_entry_remove(protocol_interface_info_entry_t *cur, mac_neighbor_table_entry_t *entry_ptr);
 static bool ws_neighbor_entry_nud_notify(mac_neighbor_table_entry_t *entry_ptr, void *user_data);
-static bool ws_rpl_dio_new_parent_accept(struct protocol_interface_info_entry *interface);
 
 
 static void ws_bootstrap_candidate_table_reset(protocol_interface_info_entry_t *cur);
@@ -321,12 +320,16 @@ static void ws_nud_entry_remove(protocol_interface_info_entry_t *cur, mac_neighb
     }
 }
 
-static bool ws_nud_message_build(protocol_interface_info_entry_t *cur, mac_neighbor_table_entry_t *neighbor)
+static bool ws_nud_message_build(protocol_interface_info_entry_t *cur, mac_neighbor_table_entry_t *neighbor, bool nud_process)
 {
     //Send NS
     uint8_t ll_target[16];
     ws_bootsrap_create_ll_address(ll_target, neighbor->mac64);
-    tr_info("NUD generate NS %u", neighbor->index);
+    if (nud_process) {
+        tr_info("NUD generate NS %u", neighbor->index);
+    } else {
+        tr_info("Probe generate NS %u", neighbor->index);
+    }
     buffer_t *buffer = icmpv6_build_ns(cur, ll_target, NULL, true, false, NULL);
     if (buffer) {
         protocol_push(buffer);
@@ -368,7 +371,7 @@ void ws_nud_active_timer(protocol_interface_info_entry_t *cur, uint16_t ticks)
 
             } else {
                 //Random TX wait period is over
-                entry->wait_response = ws_nud_message_build(cur, entry->neighbor_info);
+                entry->wait_response = ws_nud_message_build(cur, entry->neighbor_info, entry->nud_process);
                 if (!entry->wait_response) {
                     if (entry->nud_process && entry->retry_count < 2) {
                         entry->timer = randLIB_get_random_in_range(1, 900);
@@ -1591,25 +1594,6 @@ static bool ws_bootstrap_neighbor_info_request(struct protocol_interface_info_en
     return true;
 }
 
-static bool ws_rpl_dio_new_parent_accept(struct protocol_interface_info_entry *interface)
-{
-    uint16_t parent_candidate_size = rpl_control_parent_candidate_list_size(interface, false);
-    //TODO check bootstarap state for review
-    //if we have enough candidates at list do not accept new multicast neighbours
-    if (parent_candidate_size > interface->ws_info->rpl_parent_candidate_max) {
-        return false;
-    }
-
-    parent_candidate_size = rpl_control_parent_candidate_list_size(interface, true);
-    //If we have already enough parent selected Candidates count is bigger than configured
-    if (parent_candidate_size >= interface->ws_info->rpl_selected_parent_max) {
-        return false;
-    }
-
-    return true;
-}
-
-
 static void ws_neighbor_entry_remove_notify(mac_neighbor_table_entry_t *entry_ptr, void *user_data)
 {
 
@@ -1647,7 +1631,7 @@ static bool ws_neighbor_entry_nud_notify(mac_neighbor_table_entry_t *entry_ptr,
     }
 
     uint8_t ll_address[16];
-
+    bool nud_proces = false;
     if (time_from_start > WS_NEIGHBOR_NUD_TIMEOUT) {
 
         ws_bootsrap_create_ll_address(ll_address, entry_ptr->mac64);
@@ -1668,6 +1652,7 @@ static bool ws_neighbor_entry_nud_notify(mac_neighbor_table_entry_t *entry_ptr,
                 activate_nud = true;
             }
         }
+        nud_proces = activate_nud;
     } else if (etx_entry->etx_samples < WS_NEIGBOR_ETX_SAMPLE_MAX) {
         //Take Random number for trig a prope.
         //ETX Sample 0: random 1-8
@@ -1679,7 +1664,7 @@ static bool ws_neighbor_entry_nud_notify(mac_neighbor_table_entry_t *entry_ptr,
         } else {
 
             ws_bootsrap_create_ll_address(ll_address, entry_ptr->mac64);
-            if (!rpl_control_is_dodag_parent_candidate(cur, ll_address, WS_NEIGHBOUR_MAX_CANDIDATE_PROBE)) {
+            if (!rpl_control_probe_parent_candidate(cur, ll_address)) {
                 return false;
             }
 
@@ -1712,10 +1697,8 @@ static bool ws_neighbor_entry_nud_notify(mac_neighbor_table_entry_t *entry_ptr,
         ws_neighbor->accelerated_etx_probe = false;
         entry->timer = 1;
     }
+    entry->nud_process = nud_proces;
 
-    if (etx_entry->etx_samples >= WS_NEIGBOR_ETX_SAMPLE_MAX) {
-        entry->nud_process = true;
-    }
     return true;
 }
 
@@ -2150,34 +2133,70 @@ static void ws_rpl_prefix_callback(prefix_entry_t *prefix, void *handle, uint8_t
     }
 }
 
-static bool ws_rpl_new_parent_callback_t(uint8_t *ll_parent_address, void *handle)
+static bool ws_rpl_new_parent_callback(uint8_t *ll_parent_address, void *handle, struct rpl_instance *instance, uint16_t candidate_rank)
 {
 
     protocol_interface_info_entry_t *cur = handle;
     if (!cur->rpl_domain || cur->interface_mode != INTERFACE_UP) {
         return false;
     }
 
+    if (blacklist_reject(ll_parent_address)) {
+        // Rejected by blacklist
+        return false;
+    }
+
+    uint8_t replacing[16];
     uint8_t mac64[8];
-    memcpy(mac64, ll_parent_address + 8, 8);
-    mac64[0] ^= 2;
+    bool replace_ok = false;
+    bool create_ok = false;
     llc_neighbour_req_t neigh_buffer;
+    if (rpl_control_candidate_list_size(cur, instance) < cur->ws_info->rpl_parent_candidate_max) {
+        //Not reach max value yet accept then all go to create neigh table
+        goto neigh_create;
+    }
+
+
+    if (!rpl_control_find_worst_neighbor(cur, instance, replacing)) {
+        return false;
+    }
+
+    // if not yet probed, return false
+    memcpy(mac64, replacing + 8, 8);
+    mac64[0] ^= 2;
+
     if (ws_bootstrap_neighbor_info_request(cur, mac64, &neigh_buffer, false)) {
-        return true;
+        //Verify that we have proped min 1 time
+        etx_storage_t *etx_entry = etx_storage_entry_get(cur->id, neigh_buffer.neighbor->index);
+        if (etx_entry && etx_entry->etx_samples == 0) {
+            return false;
+        }
     }
 
-    if (!ws_rpl_dio_new_parent_accept(cur)) {
+    // Accept now only better one's when max candidates slected and max candidate list size is reached
+    if (!rpl_possible_better_candidate(cur, instance, replacing, candidate_rank)) {
         return false;
     }
+    //TODO if replacing has poor ETX, put it in blacklist as "poor ETX" to prevent reselection
+    //Mark That We can try remove replaced link
+    replace_ok = true;
 
-    //Discover Multicast temporary entry
+neigh_create:
+
+    memcpy(mac64, ll_parent_address + 8, 8);
+    mac64[0] ^= 2;
+    if (ws_bootstrap_neighbor_info_request(cur, mac64, &neigh_buffer, false)) {
+        create_ok = true;
+        goto neigh_create_ok;
+    }
 
+    //Discover Multicast temporary entry
     ws_neighbor_temp_class_t *entry = ws_llc_get_multicast_temp_entry(cur, mac64);
     if (!entry) {
         return false;
     }
     //Create entry
-    bool create_ok = ws_bootstrap_neighbor_info_request(cur, mac64, &neigh_buffer, true);
+    create_ok = ws_bootstrap_neighbor_info_request(cur, mac64, &neigh_buffer, true);
     if (create_ok) {
         ws_neighbor_class_entry_t *ws_neigh = neigh_buffer.ws_neighbor;
         //Copy fhss temporary data
@@ -2188,7 +2207,13 @@ static bool ws_rpl_new_parent_callback_t(uint8_t *ll_parent_address, void *handl
     }
     ws_llc_free_multicast_temp_entry(cur, entry);
 
+neigh_create_ok:
 
+    if (create_ok && replace_ok) {
+        //Try remove here when accepted new better one possible
+        tr_debug("Remove %s by %s", trace_ipv6(replacing), trace_ipv6(ll_parent_address));
+        rpl_control_neighbor_delete_from_instance(cur, instance, replacing);
+    }
     return create_ok;
 }
 
@@ -2200,7 +2225,7 @@ static void ws_bootstrap_rpl_activate(protocol_interface_info_entry_t *cur)
 
     addr_add_router_groups(cur);
     rpl_control_set_domain_on_interface(cur, protocol_6lowpan_rpl_domain, downstream);
-    rpl_control_set_callback(protocol_6lowpan_rpl_domain, ws_bootstrap_rpl_callback, ws_rpl_prefix_callback, ws_rpl_new_parent_callback_t, cur);
+    rpl_control_set_callback(protocol_6lowpan_rpl_domain, ws_bootstrap_rpl_callback, ws_rpl_prefix_callback, ws_rpl_new_parent_callback, cur);
     // If i am router I Do this
     rpl_control_force_leaf(protocol_6lowpan_rpl_domain, leaf);
     rpl_control_request_parent_link_confirmation(true);

source/6LoWPAN/ws/ws_config.h

@@ -31,7 +31,7 @@
 #define WS_RPL_DIO_DOUBLING 2
 #define WS_RPL_DIO_REDUNDANCY 0
 
-#define WS_RPL_MIN_HOP_RANK_INCREASE 196
+#define WS_RPL_MIN_HOP_RANK_INCREASE 160
 #define WS_RPL_MAX_HOP_RANK_INCREASE 2048
 
 #define WS_CERTIFICATE_RPL_MIN_HOP_RANK_INCREASE 128

source/RPL/rpl_control.c

@@ -247,6 +247,46 @@ bool rpl_control_is_dodag_parent_candidate(protocol_interface_info_entry_t *inte
     return false;
 }
 
+uint16_t rpl_control_candidate_list_size(protocol_interface_info_entry_t *interface, rpl_instance_t *rpl_instance)
+{
+    if (!interface->rpl_domain) {
+        return 0;
+    }
+
+    return rpl_instance_address_candidate_count(rpl_instance, false);
+
+}
+
+
+bool rpl_control_probe_parent_candidate(protocol_interface_info_entry_t *interface, const uint8_t ll_addr[16])
+{
+    if (!interface->rpl_domain) {
+        return false;
+    }
+    // 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_lookup_neighbour_by_ll_address(instance, ll_addr, interface->id)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool rpl_possible_better_candidate(struct protocol_interface_info_entry *interface, rpl_instance_t *rpl_instance, const uint8_t ll_addr[16], uint16_t candidate_rank)
+{
+    if (!interface->rpl_domain) {
+        return false;
+    }
+
+    rpl_neighbour_t *neighbour = rpl_lookup_neighbour_by_ll_address(rpl_instance, ll_addr, interface->id);
+    if (!neighbour) {
+        return false;
+    }
+
+    return rpl_instance_possible_better_candidate(rpl_instance, neighbour, candidate_rank);
+
+}
+
 
 uint16_t rpl_control_parent_candidate_list_size(protocol_interface_info_entry_t *interface, bool parent_list)
 {
@@ -266,6 +306,13 @@ uint16_t rpl_control_parent_candidate_list_size(protocol_interface_info_entry_t
     return parent_list_size;
 }
 
+void rpl_control_neighbor_delete_from_instance(protocol_interface_info_entry_t *interface, rpl_instance_t *instance, const uint8_t ll_addr[16])
+{
+    rpl_neighbour_t *neighbour = rpl_lookup_neighbour_by_ll_address(instance, ll_addr, interface->id);
+    if (neighbour) {
+        rpl_delete_neighbour(instance, neighbour);
+    }
+}
 
 void rpl_control_neighbor_delete(protocol_interface_info_entry_t *interface, const uint8_t ll_addr[16])
 {
@@ -274,14 +321,26 @@ void rpl_control_neighbor_delete(protocol_interface_info_entry_t *interface, con
     }
     // go through instances and delete address.
     ns_list_foreach(struct rpl_instance, instance, &interface->rpl_domain->instances) {
+        rpl_control_neighbor_delete_from_instance(interface, instance, ll_addr);
+    }
+}
 
-        rpl_neighbour_t *neighbour = rpl_lookup_neighbour_by_ll_address(instance, ll_addr, interface->id);
-        if (neighbour) {
-            rpl_delete_neighbour(instance, neighbour);
-        }
+bool rpl_control_find_worst_neighbor(protocol_interface_info_entry_t *interface, rpl_instance_t *rpl_instance, uint8_t ll_addr[static 16])
+{
+    if (!interface->rpl_domain) {
+        return false;
+    }
+
+    rpl_neighbour_t *neighbour = rpl_lookup_last_candidate_from_list(rpl_instance);
+    if (neighbour) {
+        memcpy(ll_addr, rpl_neighbour_ll_address(neighbour), 16);
+        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)
 {
@@ -1015,7 +1074,7 @@ static buffer_t *rpl_control_dio_handler(protocol_interface_info_entry_t *cur, r
     const rpl_dodag_conf_t *conf = rpl_dodag_get_config(dodag);
     if (!conf) {
         /* TODO - rate limit DIS? */
-        if (domain->new_parent_add && !domain->new_parent_add(buf->src_sa.address, domain->cb_handle)) {
+        if (domain->new_parent_add && !domain->new_parent_add(buf->src_sa.address, domain->cb_handle, instance, rank)) {
             goto invalid_parent;
         }
         rpl_control_transmit_dis(domain, cur, RPL_SOLINFO_PRED_DODAGID | RPL_SOLINFO_PRED_INSTANCEID, instance_id, dodagid, 0, buf->src_sa.address);
@@ -1049,15 +1108,21 @@ static buffer_t *rpl_control_dio_handler(protocol_interface_info_entry_t *cur, r
 
     /* Now we create the neighbour, if we don't already have a record */
     if (!neighbour) {
+
+        if (domain->new_parent_add) {
+
+            if (!domain->new_parent_add(buf->src_sa.address, domain->cb_handle, instance, rank)) {
+                goto invalid_parent;
+            }
+        }
+
         neighbour = rpl_create_neighbour(version, buf->src_sa.address, cur->id, g_mop_prf, dtsn);
         //Call Here new parent create
         if (!neighbour) {
             goto invalid_parent;
         }
 
-        if (domain->new_parent_add && !domain->new_parent_add(buf->src_sa.address, domain->cb_handle)) {
-            goto invalid_parent;
-        }
+
 
     }
 
@@ -1776,12 +1841,25 @@ static void rpl_domain_print(const rpl_domain_t *domain, route_print_fn_t *print
 
 void rpl_control_print(route_print_fn_t *print_fn)
 {
-    print_fn("RPL memory usage %zu", rpl_alloc_total);
+    unsigned t = protocol_core_monotonic_time % 10;
+    unsigned s_full = protocol_core_monotonic_time / 10;
+    unsigned m = s_full / 60;
+    unsigned s = s_full % 60;
+    unsigned h = m / 60;
+    m %= 60;
+    print_fn("Time %02u:%02u:%02u.%u (%u.%u)", h, m, s, t, s_full, t);
+    // %zu doesn't work on some Mbed toolchains
+    print_fn("RPL memory usage %" PRIu32, (uint32_t) rpl_alloc_total);
     ns_list_foreach(rpl_domain_t, domain, &rpl_domains) {
         rpl_domain_print(domain, print_fn);
     }
 }
 
+uint8_t rpl_policy_mrhof_parent_set_size_get(const rpl_domain_t *domain)
+{
+    return rpl_policy_mrhof_parent_set_size(domain);
+}
+
 #ifdef RPL_STRUCTURES_H_
 #error "rpl_structures.h should not be included by rpl_control.c"
 #endif