Added maximum frame counter storing interval

If application has not configured real time clock to nanostack, it
will now advance internal time by a day on each start up. Also
frame counter (and time) storing is forced to happen once a day.

Author: Mika Leppänen

source/6LoWPAN/ws/ws_config.h

@@ -157,10 +157,11 @@ extern uint8_t DEVICE_MIN_SENS;
 /*
  * MAC frame counter NVM storing configuration
  */
-#define FRAME_COUNTER_STORE_INTERVAL     60   // Time interval (on seconds) between frame counter store operations
-#define FRAME_COUNTER_STORE_TRIGGER      5    // Delay (on seconds) before storing, when storing of frame counters is triggered
-#define FRAME_COUNTER_INCREMENT          1000 // How much frame counter is incremented on start up
-#define FRAME_COUNTER_STORE_THRESHOLD    800  // How much frame counter must increment before it is stored
+#define FRAME_COUNTER_STORE_INTERVAL        60          // Time interval (on seconds) between checking if frame counter storing is needed
+#define FRAME_COUNTER_STORE_FORCE_INTERVAL  (3600 * 20) // Time interval (on seconds) before frame counter storing is forced (if no other storing operations triggered)
+#define FRAME_COUNTER_STORE_TRIGGER         5           // Delay (on seconds) before storing, when storing of frame counters is triggered
+#define FRAME_COUNTER_INCREMENT             1000        // How much frame counter is incremented on start up
+#define FRAME_COUNTER_STORE_THRESHOLD       800         // How much frame counter must increment before it is stored
 
 
 /*

source/6LoWPAN/ws/ws_pae_controller.c

@@ -72,7 +72,8 @@ typedef struct {
     uint8_t gtkhash[32];                                             /**< GTK hashes */
     sec_prot_certs_t certs;                                          /**< Certificates */
     nw_key_t nw_key[GTK_NUM];                                        /**< Currently active network keys (on MAC) */
-    uint16_t frame_cnt_store_timer;                                  /**< Timer for storing frame counter value */
+    uint16_t frame_cnt_store_timer;                                  /**< Timer to check if storing of frame counter value is needed */
+    uint32_t frame_cnt_store_force_timer;                            /**< Timer to force storing of frame counter, if no other updates */
     frame_counters_t frame_counters;                                 /**< Frame counters */
     sec_timer_cfg_t sec_timer_cfg;                                   /**< Timer configuration (configuration set values) */
     sec_prot_cfg_t sec_prot_cfg;                                     /**< Configuration */
@@ -669,6 +670,7 @@ static void ws_pae_controller_data_init(pae_controller_t *controller)
     controller->frame_counter_read = false;
     controller->gtk_index = -1;
     controller->frame_cnt_store_timer = FRAME_COUNTER_STORE_INTERVAL;
+    controller->frame_cnt_store_force_timer = FRAME_COUNTER_STORE_FORCE_INTERVAL;
     controller->restart_cnt = 0;
     ws_pae_controller_frame_counter_reset(&controller->frame_counters);
     sec_prot_keys_gtks_init(&controller->gtks);
@@ -1377,6 +1379,13 @@ static void ws_pae_controller_frame_counter_timer(uint16_t seconds, pae_controll
         entry->frame_cnt_store_timer = FRAME_COUNTER_STORE_INTERVAL;
         ws_pae_controller_frame_counter_store(entry, true);
     }
+
+    if (entry->frame_cnt_store_force_timer > seconds) {
+        entry->frame_cnt_store_force_timer -= seconds;
+    } else {
+        entry->frame_cnt_store_force_timer = 0;
+        ws_pae_controller_frame_counter_store(entry, true);
+    }
 }
 
 static void ws_pae_controller_frame_counter_timer_trigger(uint16_t seconds, pae_controller_t *entry)
@@ -1430,11 +1439,14 @@ static void ws_pae_controller_frame_counter_store(pae_controller_t *entry, bool
         }
     }
 
-    if (update_needed) {
+    if (update_needed || entry->frame_cnt_store_force_timer == 0) {
         tr_debug("Write frame counters: system time %"PRIu32"", protocol_core_monotonic_time / 10);
         // Writes modified frame counters
         ws_pae_nvm_store_frame_counter_tlv_create((nvm_tlv_t *) &entry->pae_nvm_buffer, entry->restart_cnt, &entry->frame_counters);
         ws_pae_controller_nvm_frame_counter_write((nvm_tlv_t *) &entry->pae_nvm_buffer);
+
+        // Reset force interval when ever values are stored
+        entry->frame_cnt_store_force_timer = FRAME_COUNTER_STORE_FORCE_INTERVAL;
     }
 }
 

source/6LoWPAN/ws/ws_pae_time.c

@@ -31,7 +31,10 @@
 #define TRACE_GROUP "wst"
 
 // Wednesday, January 1, 2020 0:00:00 GMT
-#define CURRENT_TIME_INIT_VALUE 1577836800
+#define CURRENT_TIME_INIT_VALUE        1577836800
+
+// Increment two hours in addition to maximum storing interval
+#define CURRENT_TIME_INCREMENT_VALUE   (2 * 3600)
 
 static uint64_t current_time = CURRENT_TIME_INIT_VALUE;
 static ns_time_api_system_time_callback *system_time_callback = NULL;
@@ -171,6 +174,8 @@ int8_t ws_pae_current_time_set(uint64_t time)
             tr_error("FATAL: system time less than reference time or more than 12 months in future: %"PRIi64" reference time: %"PRIi64, system_time, current_time);
             return -1;
         }
+    } else {
+        current_time += FRAME_COUNTER_STORE_FORCE_INTERVAL + CURRENT_TIME_INCREMENT_VALUE;
     }
 
     return 0;