context id update (ARMmbed#1753)

context id not deleted if domain prefix exists for the
context id that is being deleted.

Author: deepakvenugopal

source/6LoWPAN/Thread/thread_extension.c

@@ -668,6 +668,18 @@ void thread_extension_activate(protocol_interface_info_entry_t *cur)
     }
 }
 
+bool thread_extension_context_can_delete(int8_t id, uint8_t servicesPrefix[16], uint8_t context_prefix_length)
+{
+    uint8_t domain_prefix[16];
+    uint8_t domain_prefix_len;
+    if (0 == thread_extension_network_prefix_get(id, NULL,domain_prefix, &domain_prefix_len)) {
+        if (context_prefix_length == domain_prefix_len && memcmp(domain_prefix, servicesPrefix, context_prefix_length/8) == 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
 bool thread_extension_enabled(protocol_interface_info_entry_t *cur)
 {
     if (thread_info(cur)->version <= THREAD_PROTOCOL_VERSION) {

source/6LoWPAN/Thread/thread_extension.h

@@ -58,6 +58,7 @@ void thread_extension_address_registration_trigger(protocol_interface_info_entry
 void thread_extension_route_set(protocol_interface_info_entry_t *cur);
 void thread_extension_activate(protocol_interface_info_entry_t *cur);
 bool thread_extension_enabled(protocol_interface_info_entry_t *cur);
+bool thread_extension_context_can_delete(int8_t id, uint8_t servicesPrefix[16], uint8_t context_prefix_length);
 bool thread_extension_version_check(uint8_t version);
 void thread_extension_discover_response_read(struct discovery_response_list *nwk_info, uint16_t discover_response_tlv, uint8_t *data_ptr, uint16_t data_len);
 void thread_extension_discover_response_tlv_write(uint16_t *data, uint8_t version, uint16_t securityPolicy);
@@ -95,6 +96,7 @@ uint8_t *thread_extension_discover_response_write(protocol_interface_info_entry_
 #define thread_extension_joining_enabled(interface_id) false
 #define thread_extension_discover_response_len(cur) 0
 #define thread_extension_discover_response_write(cur, ptr) (ptr)
+#define thread_extension_context_can_delete(id, servicesPrefix, context_prefix_length) false
 #endif
 
 #ifdef __cplusplus

source/6LoWPAN/Thread/thread_leader_service.c

@@ -1526,7 +1526,7 @@ void thread_leader_service_timer(protocol_interface_info_entry_t *cur, uint32_t
         cur->thread_info->leader_private_data->leader_id_seq_timer = ID_SEQUENCE_PERIOD;
 
         thread_leader_service_update_id_set(cur);
-        thread_network_data_context_re_use_timer_update(&cur->thread_info->networkDataStorage, 10, &cur->lowpan_contexts);
+        thread_network_data_context_re_use_timer_update(cur->id, &cur->thread_info->networkDataStorage, 10, &cur->lowpan_contexts);
         // Send update to network data if needed
         thread_leader_service_network_data_changed(cur, false, false);
     }

source/6LoWPAN/Thread/thread_network_data_storage.c

@@ -868,7 +868,7 @@ static int thread_service_data_delete_mark_by_router_id(thread_network_data_serv
     return retVal;
 }
 
-static int thread_server_context_clean(thread_network_data_cache_entry_t *cachePtr, thread_data_context_list_t *listPtr, thread_network_data_prefix_cache_entry_t *prefixEntry, lowpan_context_list_t *context_list)
+static int thread_server_context_clean(int8_t id, thread_network_data_cache_entry_t *cachePtr, thread_data_context_list_t *listPtr, thread_network_data_prefix_cache_entry_t *prefixEntry, lowpan_context_list_t *context_list)
 {
     int retVal = -1;
     (void) prefixEntry;
@@ -879,7 +879,9 @@ static int thread_server_context_clean(thread_network_data_cache_entry_t *cacheP
                 cachePtr->stableUpdatePushed = true;
             }
             // Set context lifetime to 0 to delete
-            lowpan_context_update(context_list, cur->cid, 0, NULL, 0, true);
+            if (thread_extension_context_can_delete(id, prefixEntry->servicesPrefix, cur->contextPrefixLength)) {
+                lowpan_context_update(context_list, cur->cid, 0, NULL, 0, true);
+            }
             ns_list_remove(listPtr, cur);
             ns_dyn_mem_free(cur);
             retVal = 0;
@@ -1019,7 +1021,7 @@ bool thread_network_data_router_id_free(thread_network_data_cache_entry_t *cache
         }
         thread_server_data_clean_by_router_id(cachePtr, &cur->routeList, cur, true, curInterface);
         if (!is_leader) {
-            thread_server_context_clean(cachePtr, &cur->contextList, cur, &curInterface->lowpan_contexts);
+            thread_server_context_clean(curInterface->id, cachePtr, &cur->contextList, cur, &curInterface->lowpan_contexts);
         }
 
         if (ns_list_is_empty(&cur->borderRouterList)) {
@@ -1071,7 +1073,7 @@ bool thread_network_data_router_id_free(thread_network_data_cache_entry_t *cache
     return address_removed;
 }
 
-void thread_network_data_context_re_use_timer_update(thread_network_data_cache_entry_t *cachePtr, uint32_t ticks, lowpan_context_list_t *context_list)
+void thread_network_data_context_re_use_timer_update(int8_t id, thread_network_data_cache_entry_t *cachePtr, uint32_t ticks, lowpan_context_list_t *context_list)
 {
     ns_list_foreach_safe(thread_network_data_prefix_cache_entry_t, cur, &cachePtr->localPrefixList) {
         ns_list_foreach_safe(thread_network_data_context_entry_t, curContext, &cur->contextList) {
@@ -1086,7 +1088,9 @@ void thread_network_data_context_re_use_timer_update(thread_network_data_cache_e
                         cachePtr->temporaryUpdatePushed = true;
                     }
                     // Set context lifetime to 0 to delete
-                    lowpan_context_update(context_list, curContext->cid, 0, NULL, 0, true);
+                    if (thread_extension_context_can_delete(id, cur->servicesPrefix,curContext->contextPrefixLength)) {
+                        lowpan_context_update(context_list, curContext->cid, 0, NULL, 0, true);
+                    }
                     ns_dyn_mem_free(curContext);
                 }
             }

source/6LoWPAN/Thread/thread_network_data_storage.h

@@ -207,7 +207,7 @@ bool thread_network_data_router_id_free(thread_network_data_cache_entry_t *cache
 
 void thread_network_local_data_free_and_clean(thread_network_local_data_cache_entry_t *cachePtr, int8_t interface_id);
 
-void thread_network_data_context_re_use_timer_update(thread_network_data_cache_entry_t *cachePtr, uint32_t ticks, lowpan_context_list_t *context_list);
+void thread_network_data_context_re_use_timer_update(int8_t id, thread_network_data_cache_entry_t *cachePtr, uint32_t ticks, lowpan_context_list_t *context_list);
 
 /**
  * Add new route information to route List

test/nanostack/unittest/stub/thread_network_data_storage_stub.c

@@ -193,7 +193,7 @@ bool thread_network_data_router_id_free(thread_network_data_cache_entry_t *cache
     return false;
 }
 
-void thread_network_data_context_re_use_timer_update(thread_network_data_cache_entry_t *cachePtr, uint32_t ticks, lowpan_context_list_t *context_list)
+void thread_network_data_context_re_use_timer_update(int8_t id, thread_network_data_cache_entry_t *cachePtr, uint32_t ticks, lowpan_context_list_t *context_list)
 {
 
 }