REED parser refactoring for MLE advertisement (#1654)

Refactored REED parser logic for MLE advertisement to make function more
simpler, and some unneeded code removed.

Author: Tero Heinonen

source/6LoWPAN/Thread/thread_mle_message_handler.c

@@ -224,8 +224,6 @@ static bool thread_router_leader_data_process(protocol_interface_info_entry_t *c
             // Request network data if we have a 2-way link
             tr_debug("Request New Network Data from %s", trace_ipv6(src_address));
             thread_network_data_request_send(cur, src_address, true);
-        } else {
-
         }
     } else if (leaderDataUpdate == 2) {
         tr_debug("Start Merge");
@@ -323,14 +321,31 @@ static void thread_update_mle_entry(protocol_interface_info_entry_t *cur, mle_me
     return;
 }
 
+static bool thread_parse_advertisement_from_parent(protocol_interface_info_entry_t *cur, thread_leader_data_t *leader_data, uint16_t short_address)
+{
+    if ((thread_info(cur)->thread_leader_data->partitionId != leader_data->partitionId) ||
+        (thread_info(cur)->thread_leader_data->weighting != leader_data->weighting)) {
+        //parent changed partition/weight - reset own routing information
+        thread_old_partition_data_purge(cur);
+    }
+    //check if network data needs to be requested
+    if (!thread_bootstrap_request_network_data(cur, leader_data, short_address)) {
+        tr_debug("Parent short address changed - re-attach");
+        thread_bootstrap_connection_error(cur->id, CON_PARENT_CONNECT_DOWN, NULL);
+        return false;
+    }
+
+    return true;
+}
+
 static void thread_parse_advertisement(protocol_interface_info_entry_t *cur, mle_message_t *mle_msg, mle_security_header_t *security_headers, uint8_t linkMargin)
 {
     mle_tlv_info_t routeTlv;
     thread_leader_data_t leaderData;
     mle_neigh_table_entry_t *entry_temp;
     uint16_t shortAddress;
-    bool my_parent;
     bool adv_from_my_partition;
+    bool my_parent;
 
     // Check device mode & bootstrap state
     if ((thread_info(cur)->thread_device_mode == THREAD_DEVICE_MODE_SLEEPY_END_DEVICE) ||
@@ -348,7 +363,9 @@ static void thread_parse_advertisement(protocol_interface_info_entry_t *cur, mle
     // Get MLE entry
     entry_temp = mle_class_get_entry_by_ll64(cur->id, linkMargin, mle_msg->packet_src_address, false, NULL);
 
+    // Check if this is from my parent
     my_parent = thread_check_is_this_my_parent(cur, entry_temp);
+
     adv_from_my_partition = thread_instance_id_matches(cur, &leaderData);
 
     if ((security_headers->KeyIdMode == MAC_KEY_ID_MODE_SRC4_IDX) && adv_from_my_partition) {
@@ -361,22 +378,10 @@ static void thread_parse_advertisement(protocol_interface_info_entry_t *cur, mle
         entry_temp = NULL;
     }
 
-    // Check parent status
-    if (!thread_attach_active_router(cur)) {
-        //processing for non routers
-        if (my_parent) {
-            //advertisement from parent
-            if ((thread_info(cur)->thread_leader_data->partitionId != leaderData.partitionId) ||
-                (thread_info(cur)->thread_leader_data->weighting != leaderData.weighting)) {
-                //parent changed partition/weight - reset own routing information
-                thread_old_partition_data_purge(cur);
-            }
-            //check if network data needs to be requested
-            if (!thread_bootstrap_request_network_data(cur, &leaderData, shortAddress)) {
-                tr_debug("Parent short address changed - re-attach");
-                thread_bootstrap_connection_error(cur->id, CON_PARENT_CONNECT_DOWN, NULL);
-                return;
-            }
+    /* Check parent status */
+    if (!thread_attach_active_router(cur) && my_parent) {
+        if (!thread_parse_advertisement_from_parent(cur, &leaderData, shortAddress)) {
+            return;
         }
     }
 
@@ -385,30 +390,28 @@ static void thread_parse_advertisement(protocol_interface_info_entry_t *cur, mle
 
     // Process advertisement
     if (thread_info(cur)->thread_device_mode != THREAD_DEVICE_MODE_END_DEVICE) {
+        /* REED and FED */
         if (!thread_attach_active_router(cur)) {
-            // REED and FED
-            if (!entry_temp && thread_bootstrap_link_create_check(cur, shortAddress) && thread_bootstrap_link_create_allowed(cur, shortAddress, mle_msg->packet_src_address)) {
-                if ((thread_info(cur)->thread_leader_data->partitionId == leaderData.partitionId) &&
-                        (thread_info(cur)->thread_leader_data->weighting == leaderData.weighting)) {
+            /* Check if advertisement is from same partition */
+            if (thread_info(cur)->thread_leader_data->weighting == leaderData.weighting && thread_info(cur)->thread_leader_data->partitionId == leaderData.partitionId ) {
+                if (!entry_temp && thread_bootstrap_link_create_check(cur, shortAddress) && thread_bootstrap_link_create_allowed(cur, shortAddress, mle_msg->packet_src_address)) {
                     // Create link to new neighbor no other processing allowed
                     thread_link_request_start(cur, mle_msg->packet_src_address);
                     return;
                 }
-                if (!thread_router_leader_data_process(cur, mle_msg->packet_src_address, &leaderData, &routeTlv, entry_temp)) {
-                    // better partition found or new network data learn started
+            /* Advertisement from higher / lower partition */
+            } else {
+                // process REED advertisement from higher partition
+                if (thread_reed_partitions_merge(cur, shortAddress, leaderData)) {
                     return;
                 }
+                // REED advertisement to lower partition to help merge faster
+                if (thread_heard_lower_partition(cur,leaderData)) {
+                    thread_router_bootstrap_reed_merge_advertisement(cur);
+                }
             }
-            // process REED advertisement from higher partition
-            if (thread_reed_partitions_merge(cur, shortAddress, leaderData)) {
-                return;
-            }
-            // REED advertisement to lower partition to help merge faster
-            if (thread_heard_lower_partition(cur,leaderData)) {
-                thread_router_bootstrap_reed_merge_advertisement(cur);
-            }
+        /* ROUTER */
         } else {
-            //Router
             if (!thread_router_leader_data_process(cur, mle_msg->packet_src_address, &leaderData, &routeTlv, entry_temp) ) {
                 return;
             }