implemented Sleepy End Device child update requests. (#1570)

SED sends periodic child update requests to parent before MLE timeout.
This helps the SED to find a new parent if parent has removed it from
neighbour table during partition change.

Author: deepakvenugopal

source/6LoWPAN/Thread/thread_bootstrap.c

@@ -112,7 +112,6 @@ static void thread_bootsrap_network_discovery_failure(int8_t interface_id);
 
 static void thread_neighbor_remove(int8_t interface_id, mle_neigh_table_entry_t *cur);
 static void thread_bootsrap_network_join_start(struct protocol_interface_info_entry *cur_interface, discovery_response_list_t *nwk_info);
-static int8_t thread_child_keep_alive(int8_t interface_id, const uint8_t *mac64);
 
 
 
@@ -134,37 +133,6 @@ static void thread_neighbor_remove(int8_t interface_id, mle_neigh_table_entry_t
     thread_reset_neighbour_info(cur_interface, cur);
 }
 
-
-static bool thread_child_keep_alive_callback(int8_t interface_id, uint16_t msgId, bool usedAllRetries)
-{
-    uint8_t mac64[8];
-    uint8_t *ll64_ptr = mle_service_get_msg_destination_address_pointer(msgId);
-
-    memcpy(mac64, ll64_ptr + 8, 8);
-    mac64[0] ^= 2;
-
-    mle_neigh_table_entry_t *neig_info = mle_class_get_by_link_address(interface_id, mac64, ADDR_802_15_4_LONG);
-
-    if (!neig_info) {
-        return false;//Why entry is removed before timeout??
-    }
-
-
-    if (neig_info->ttl > MLE_TABLE_CHALLENGE_TIMER) {
-        return false;
-    }
-
-
-    if (usedAllRetries) {
-
-        //GET entry
-        mle_class_remove_entry(interface_id, neig_info);
-        return false;
-    }
-
-    return true;
-}
-
 int8_t thread_mle_class_init(int8_t interface_id)
 {
     protocol_interface_info_entry_t *cur = protocol_stack_interface_info_get_by_id(interface_id);
@@ -182,7 +150,7 @@ int8_t thread_mle_class_init(int8_t interface_id)
         return -1;
     }
 
-    if (mle_class_init(interface_id, buffer.device_decription_table_size - 1, &thread_neighbor_remove, &thread_child_keep_alive, &thread_interface_is_active) != 0) {
+    if (mle_class_init(interface_id, buffer.device_decription_table_size - 1, &thread_neighbor_remove, &thread_host_bootstrap_child_update, &thread_interface_is_active) != 0) {
         return -1;
     }
 
@@ -231,68 +199,6 @@ uint8_t thread_mode_get_by_interface_ptr(protocol_interface_info_entry_t *cur)
     return mle_mode;
 }
 
-static int8_t thread_child_keep_alive(int8_t interface_id, const uint8_t *mac64)
-{
-    mle_message_timeout_params_t timeout;
-    uint8_t ll64[16];
-    protocol_interface_info_entry_t *cur = protocol_stack_interface_info_get_by_id(interface_id);
-    uint32_t keySequence;
-    uint16_t bufId;
-    uint8_t mode;
-    if (!cur) {
-        return -1;
-    }
-
-    if (!thread_info(cur)) {
-        return -1;
-    }
-
-    //routers do not send keep alive
-    if (thread_i_am_router(cur)){
-    	return -1;
-    }
-
-    tr_debug("Child Keep Alive");
-    bufId = mle_service_msg_allocate(cur->id, 150 + 3 + 6 + 10, false,MLE_COMMAND_CHILD_UPDATE_REQUEST);
-    if (bufId == 0) {
-        return -1;
-    }
-
-    thread_management_get_current_keysequence(cur->id, &keySequence);
-    mle_service_msg_update_security_params(bufId, 5, 2, keySequence);
-    mode = thread_mode_get_by_interface_ptr(cur);
-
-    uint8_t *ptr = mle_service_get_data_pointer(bufId);
-    ptr = mle_general_write_source_address(ptr, cur);
-    ptr = mle_tlv_write_mode(ptr, mode);
-
-    ptr = thread_leader_data_tlv_write(ptr, cur);
-
-    //Set Addresss TLV
-    if ((mode & MLE_FFD_DEV) == 0) {
-        ptr = thread_address_registration_tlv_write(ptr, cur);
-    }
-
-    memcpy(ll64, ADDR_LINK_LOCAL_PREFIX, 8);
-    memcpy(&ll64[8], mac64, 8);
-    ll64[8] ^= 2;
-    if (mle_service_update_length_by_ptr(bufId,ptr)!= 0) {
-        tr_debug("Buffer overflow at message write");
-    }
-    timeout.retrans_max = 3;
-    timeout.timeout_init = 1;
-    timeout.timeout_max = 4;
-    timeout.delay = MLE_NO_DELAY;
-
-    //SET Destination address
-    mle_service_set_msg_destination_address(bufId, ll64);
-    //Set Callback
-    mle_service_set_packet_callback(bufId, thread_child_keep_alive_callback);
-    mle_service_set_msg_timeout_parameters(bufId, &timeout);
-    mle_service_send_message(bufId);
-    return 0;
-}
-
 /**
  * Return lower (worse) of the two margins.
  */
@@ -1014,6 +920,7 @@ static void thread_interface_bootsrap_mode_init(protocol_interface_info_entry_t
         cur->thread_info->thread_device_mode = THREAD_DEVICE_MODE_SLEEPY_END_DEVICE;
         //SET Sleepy Host To RX on Idle mode for bootsrap
         nwk_thread_host_control(cur, NET_HOST_RX_ON_IDLE, 0);
+        cur->thread_info->childUpdateReqTimer = 0.8 * cur->thread_info->host_link_timeout;
     } else {
         tr_debug("Set End node Mode");
         cur->thread_info->thread_device_mode = THREAD_DEVICE_MODE_END_DEVICE;
@@ -1134,7 +1041,9 @@ void thread_tasklet(arm_event_s *event)
 
         case THREAD_CHILD_UPDATE:
             tr_debug_extra("Thread SM THREAD_CHILD_UPDATE");
-            thread_bootstrap_child_update(cur);
+            if (thread_info(cur)->thread_endnode_parent) {
+                thread_host_bootstrap_child_update(cur->id, cur->thread_info->thread_endnode_parent->mac64);
+            }
             break;
         case THREAD_ANNOUNCE_ACTIVE: {
             tr_debug_extra("Thread SM THREAD_ANNOUNCE_ACTIVE");
@@ -2333,21 +2242,7 @@ void thread_bootstrap_stop(protocol_interface_info_entry_t *cur)
 
 void thread_bootstrap_child_update_trig(protocol_interface_info_entry_t *cur)
 {
-    if (cur->thread_info->thread_attached_state == THREAD_STATE_CONNECTED) {
-        if (cur->thread_info->thread_endnode_parent == NULL) {
-            return;
-        }
-
-        if (cur->thread_info->thread_endnode_parent->childUpdateProcessActive) {
-            //Set Pending if earlier proces is already started
-            cur->thread_info->thread_endnode_parent->childUpdatePending = true;
-            return;
-        }
-        //Trig event
-        cur->thread_info->thread_endnode_parent->childUpdatePending = false;
-        cur->thread_info->thread_endnode_parent->childUpdateProcessActive = true;
-        cur->thread_info->thread_endnode_parent->childUpdateProcessStatus = false;
-
+    if (cur->thread_info->thread_attached_state == THREAD_STATE_CONNECTED && cur->thread_info->thread_endnode_parent) {
         thread_bootsrap_event_trig(THREAD_CHILD_UPDATE, cur->bootStrapId, ARM_LIB_HIGH_PRIORITY_EVENT);
     }
 }

source/6LoWPAN/Thread/thread_common.c

@@ -880,7 +880,6 @@ static void thread_child_update_req_timer(protocol_interface_info_entry_t *cur,
     if (cur->thread_info->childUpdateReqTimer == -1) {
         return;
     }
-
     if (cur->thread_info->childUpdateReqTimer > seconds) {
         cur->thread_info->childUpdateReqTimer -= seconds;
     } else {

source/6LoWPAN/Thread/thread_common.h

@@ -174,7 +174,6 @@ typedef struct thread_parent_info_s {
     uint8_t pathCostToLeader;
     bool    childUpdatePending: 1;
     bool    childUpdateProcessActive: 1;
-    bool    childUpdateProcessStatus: 1;
 } thread_parent_info_t;
 
 
@@ -289,6 +288,7 @@ typedef struct thread_info_s {
     uint16_t reedJitterTimer;
     uint16_t routerIdReqCoapID;  // COAP msg id of RouterID request
     int16_t childUpdateReqTimer;
+    uint16_t childUpdateReqMsgId;
     uint16_t proactive_an_timer;
     //uint8_t lastValidRouteMask[8];
     int8_t interface_id; //Thread Interface ID

source/6LoWPAN/Thread/thread_host_bootstrap.c

@@ -1106,45 +1106,35 @@ static int thread_attach_child_id_request_build(protocol_interface_info_entry_t
 static bool thread_child_update_timeout_cb(int8_t interface_id, uint16_t msgId, bool usedAllRerties)
 {
     protocol_interface_info_entry_t *cur = protocol_stack_interface_info_get_by_id(interface_id);
-    (void)msgId;
     if (!cur || !cur->thread_info->thread_endnode_parent) {
         return false;
     }
-    tr_debug("Child Update CB");
-    if (cur->thread_info->thread_endnode_parent->childUpdateProcessStatus) {
-        //This process is ready
-        cur->thread_info->thread_endnode_parent->childUpdateProcessStatus = false;
-        if (!cur->thread_info->thread_endnode_parent->childUpdatePending) {
-
-            cur->thread_info->thread_endnode_parent->childUpdateProcessActive = false;
-            //Disable Poll
-            mac_data_poll_protocol_poll_mode_decrement(cur);
-            tr_debug("Child Update ready");
-        } else {
-            cur->thread_info->thread_endnode_parent->childUpdatePending = false;
-            tr_debug("Child Update Pending");
-            thread_bootsrap_event_trig(THREAD_CHILD_UPDATE, cur->bootStrapId, ARM_LIB_HIGH_PRIORITY_EVENT);
-        }
+    if (msgId != cur->thread_info->childUpdateReqMsgId) {
+        //Wrong message id
         return false;
     }
 
     if (usedAllRerties) {
-
+        tr_debug("Child Update timed out");
         cur->thread_info->thread_endnode_parent->childUpdatePending = false;
         cur->thread_info->thread_endnode_parent->childUpdateProcessActive = false;
-        cur->thread_info->thread_endnode_parent->childUpdateProcessStatus = false;
         mac_data_poll_protocol_poll_mode_decrement(cur);
         thread_bootstrap_reset_restart(cur->id);
         tr_debug("Restart attachment");
         return false;
     }
+    if (cur->thread_info->thread_endnode_parent->childUpdateProcessActive) {
+        // we have not received response so re-send
+        return true;
+    }
 
-    return true;
+    return false;
 
 }
 
-int8_t thread_bootstrap_child_update(protocol_interface_info_entry_t *cur)
+int8_t thread_host_bootstrap_child_update(int8_t interface_id, const uint8_t *mac64)
 {
+    protocol_interface_info_entry_t *cur = protocol_stack_interface_info_get_by_id(interface_id);
     mle_message_timeout_params_t timeout;
     uint8_t mode;
     uint32_t keySequence;
@@ -1153,6 +1143,16 @@ int8_t thread_bootstrap_child_update(protocol_interface_info_entry_t *cur)
         return -1;
     }
 
+    if (cur->thread_info->thread_endnode_parent->childUpdateProcessActive) {
+        //Set Pending if earlier process is already started
+        cur->thread_info->thread_endnode_parent->childUpdatePending = true;
+        return -1;
+    }
+    //Trig event
+    cur->thread_info->thread_endnode_parent->childUpdatePending = false;
+    cur->thread_info->thread_endnode_parent->childUpdateProcessActive = true;
+
+
     tr_debug("Child Update Request");
 
     mode = thread_mode_get_by_interface_ptr(cur);
@@ -1169,11 +1169,12 @@ int8_t thread_bootstrap_child_update(protocol_interface_info_entry_t *cur)
 
     uint8_t *address_ptr = mle_service_get_msg_destination_address_pointer(bufId);
     memcpy(address_ptr, ADDR_LINK_LOCAL_PREFIX, 8);
-    memcpy(address_ptr + 8, cur->thread_info->thread_endnode_parent->mac64, 8);
+    memcpy(address_ptr + 8, mac64, 8);
     address_ptr[8] ^= 2;
 
     uint8_t *ptr = mle_service_get_data_pointer(bufId);
     ptr = mle_tlv_write_mode(ptr, mode);
+    ptr = mle_general_write_source_address(ptr, cur);
     ptr = mle_tlv_write_timeout(ptr, cur->thread_info->host_link_timeout);
     ptr = thread_leader_data_tlv_write(ptr, cur);
 
@@ -1194,6 +1195,7 @@ int8_t thread_bootstrap_child_update(protocol_interface_info_entry_t *cur)
         thread_end_device_mode_set(cur, false);
     }
     mac_data_poll_init_protocol_poll(cur);
+    cur->thread_info->childUpdateReqMsgId = bufId;
     mle_service_set_packet_callback(bufId, thread_child_update_timeout_cb);
     mle_service_set_msg_timeout_parameters(bufId, &timeout);
     mle_service_send_message(bufId);

source/6LoWPAN/Thread/thread_host_bootstrap.h

@@ -42,7 +42,7 @@ struct protocol_interface_info_entry;
 struct mle_security_header;
 
 void thread_network_attach_start(struct protocol_interface_info_entry *cur);
-int8_t thread_bootstrap_child_update(struct protocol_interface_info_entry *cur);
+int8_t thread_host_bootstrap_child_update(int8_t interface_id, const uint8_t *mac64);
 int thread_host_bootstrap_child_update_negative_response(protocol_interface_info_entry_t *cur, uint8_t *dstAddress, mle_tlv_info_t *challenge);
 void thread_child_set_default_route(struct protocol_interface_info_entry *cur);
 

source/6LoWPAN/Thread/thread_mle_message_handler.c

@@ -764,7 +764,7 @@ static void thread_parse_child_update_response(protocol_interface_info_entry_t *
     bool leader_data_received;
 
     tr_debug("Child Update Response");
-
+    //mle_service_buffer_find
     leader_data_received = thread_leader_data_parse(mle_msg->data_ptr, mle_msg->data_length, &leaderData);
     entry_temp = mle_class_get_entry_by_ll64(cur->id, linkMargin, mle_msg->packet_src_address, false);
 
@@ -783,8 +783,7 @@ static void thread_parse_child_update_response(protocol_interface_info_entry_t *
         return;
     }
 
-    if ((security_headers->KeyIdMode == MAC_KEY_ID_MODE_SRC4_IDX)
-            && (thread_instance_id_matches(cur, &leaderData))) {
+    if (security_headers->KeyIdMode == MAC_KEY_ID_MODE_SRC4_IDX) {
         thread_management_key_synch_req(cur->id, common_read_32_bit(security_headers->Keysource));
     } else {
         tr_debug("Key ID Mode 2 not used; dropped.");
@@ -796,20 +795,36 @@ static void thread_parse_child_update_response(protocol_interface_info_entry_t *
         return;
     }
 
+    timeout = cur->thread_info->host_link_timeout;
     if (mle_tlv_read_32_bit_tlv(MLE_TYPE_TIMEOUT, mle_msg->data_ptr, mle_msg->data_length, &timeout)) {
         entry_temp->holdTime = 90;
         tr_debug("Setting child timeout, value=%"PRIu32, timeout);
         mle_entry_timeout_update(entry_temp, timeout);
-        thread_info(cur)->thread_endnode_parent->childUpdateProcessStatus = true;
     }
+
     tr_debug("Keep-Alive -->Respond from Parent");
     mle_entry_timeout_refresh(entry_temp);
 
     //Save possible new Leader Data
     if (leader_data_received) {
         thread_save_leader_data(cur, &leaderData);
     }
+
+    if (cur->thread_info->thread_device_mode == THREAD_DEVICE_MODE_SLEEPY_END_DEVICE) {
+        if  (cur->thread_info->childUpdateReqTimer < 1) {
+            cur->thread_info->childUpdateReqTimer = 0.8 * timeout;
+        }
+    }
+    //This process is ready
+    cur->thread_info->thread_endnode_parent->childUpdateProcessActive = false;
+    if (cur->thread_info->thread_endnode_parent->childUpdatePending) {
+        tr_debug("Child Update Pending");
+        thread_bootsrap_event_trig(THREAD_CHILD_UPDATE, cur->bootStrapId, ARM_LIB_HIGH_PRIORITY_EVENT);
+        return;
+    }
+
     mac_data_poll_protocol_poll_mode_decrement(cur);
+
 }
 
 #endif

test/nanostack/unittest/stub/thread_host_bootstrap_stub.c

@@ -83,7 +83,7 @@ void thread_endevice_synch_start(protocol_interface_info_entry_t *cur)
 {
 }
 
-int8_t thread_bootstrap_child_update(protocol_interface_info_entry_t *cur)
+int8_t thread_host_bootstrap_child_update(int8_t interface_id, const uint8_t *mac64)
 {
     return 0;
 }