Commit 7532a23d authored by Andreas Chmielewski's avatar Andreas Chmielewski Committed by Fabio Baltieri
Browse files

net: lwm2m: Try to reuse registration in case of a network error 



For most of the times it is not necessary to do a full registration
once a connection is established after a network error. This is in
particular not needed if lifetime is not yet expired and the server
does not refuse a registration update.

Signed-off-by: default avatarAndreas Chmielewski <andreas.chmielewski@grandcentrix.net>
parent 74a56b05

doc/connectivity/networking/api/images/lwm2m_engine_state_machine.png

+28.2 KiB (136 KiB)
Loading image diff...

subsys/net/lib/lwm2m/lwm2m_rd_client.c

+88 −33
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ enum sm_engine_state { 
	ENGINE_REGISTRATION_SENT,

	ENGINE_REGISTRATION_DONE,

	ENGINE_REGISTRATION_DONE_RX_OFF,

	ENGINE_UPDATE_REGISTRATION,

	ENGINE_UPDATE_SENT,

	ENGINE_SUSPENDED,

	ENGINE_DEREGISTER,
@@ -183,7 +184,7 @@ static void set_sm_state(uint8_t sm_state) 
		    client.engine_state <= ENGINE_DEREGISTER_SENT)) {

		event = LWM2M_RD_CLIENT_EVENT_DISCONNECT;

	} else if (sm_state == ENGINE_NETWORK_ERROR) {

		lwm2m_engine_stop(client.ctx);

		lwm2m_socket_close(client.ctx);

		client.retry_delay = 1 << client.retries;

		client.retries++;

		if (client.retries > CONFIG_LWM2M_RD_CLIENT_MAX_RETRIES) {
@@ -209,6 +210,16 @@ static void set_sm_state(uint8_t sm_state) 
	}

}



static bool sm_is_bootstrap(void)

{

#if defined(CONFIG_LWM2M_RD_CLIENT_SUPPORT_BOOTSTRAP)

	return (client.engine_state >= ENGINE_DO_BOOTSTRAP_REG &&

		client.engine_state <= ENGINE_BOOTSTRAP_TRANS_DONE);

#else

	return false;

#endif

}



static bool sm_is_registered(void)

{

	return (client.engine_state >= ENGINE_REGISTRATION_DONE &&
@@ -281,15 +292,15 @@ static void socket_fault_cb(int error) 
{

	LOG_ERR("RD Client socket error: %d", error);



	lwm2m_engine_stop(client.ctx);



	if (sm_is_bootstrap()) {

		client.ctx->sec_obj_inst = -1;

		/* force full registration */

		client.last_update = 0;

	}



	/* Jump directly to the registration phase. In case there is no valid

	 * security object for the LWM2M server, it will fall back to the

	 * bootstrap procedure.

	 */

	set_sm_state(ENGINE_DO_REGISTRATION);

	lwm2m_socket_close(client.ctx);



	set_sm_state(ENGINE_NETWORK_ERROR);

}



/* force re-update with remote peer */
@@ -977,7 +988,6 @@ static int sm_do_registration(void) 
static int sm_registration_done(void)

{

	int ret = 0;

	bool update_objects;



	/*

	 * check for lifetime seconds - SECONDS_TO_UPDATE_EARLY
@@ -987,39 +997,61 @@ static int sm_registration_done(void) 
	    (client.trigger_update ||

	     ((client.lifetime - SECONDS_TO_UPDATE_EARLY) <=

	      (k_uptime_get() - client.last_update) / 1000))) {

		set_sm_state(ENGINE_UPDATE_REGISTRATION);

	}



	if (IS_ENABLED(CONFIG_LWM2M_QUEUE_MODE_ENABLED) &&

	    (client.engine_state != ENGINE_REGISTRATION_DONE_RX_OFF) &&

	    (((k_uptime_get() - client.last_tx) / 1000) >=

	     CONFIG_LWM2M_QUEUE_MODE_UPTIME)) {

		set_sm_state(ENGINE_REGISTRATION_DONE_RX_OFF);

	}



	return ret;

}



static int update_registration(void)

{

	int ret;

	bool update_objects;



	update_objects = client.update_objects;

	client.trigger_update = false;

	client.update_objects = false;



	ret = lwm2m_engine_connection_resume(client.ctx);

	if (ret) {

			lwm2m_engine_stop(client.ctx);

			/* perform full registration */

			set_sm_state(ENGINE_DO_REGISTRATION);

		return ret;

	}



	ret = sm_send_registration(update_objects,

				   do_update_reply_cb,

				   do_update_timeout_cb);

		if (!ret) {

			set_sm_state(ENGINE_UPDATE_SENT);

		} else {

	if (ret) {

		LOG_ERR("Registration update err: %d", ret);

		return ret;

	}



	return 0;

}



static int sm_update_registration(void)

{

	int ret;



	ret = update_registration();

	if (ret) {

		LOG_ERR("Failed to update registration. Falling back to full registration");



		lwm2m_engine_stop(client.ctx);

		/* perform full registration */

		set_sm_state(ENGINE_DO_REGISTRATION);

		}

		return ret;

	}



	if (IS_ENABLED(CONFIG_LWM2M_QUEUE_MODE_ENABLED) &&

	    (client.engine_state != ENGINE_REGISTRATION_DONE_RX_OFF) &&

	    (((k_uptime_get() - client.last_tx) / 1000) >=

	     CONFIG_LWM2M_QUEUE_MODE_UPTIME)) {

		set_sm_state(ENGINE_REGISTRATION_DONE_RX_OFF);

	}

	set_sm_state(ENGINE_UPDATE_SENT);



	return ret;

	return 0;

}



static int sm_do_deregister(void)
@@ -1080,6 +1112,8 @@ close_ctx: 


static void sm_do_network_error(void)

{

	int err;



	if (--client.retry_delay > 0) {

		return;

	}
@@ -1091,7 +1125,24 @@ static void sm_do_network_error(void) 
	}

#endif



	if (!client.last_update || (k_uptime_get() - client.last_update) / 1000 > client.lifetime) {

		/* do full registration as there is no active registration or lifetime exceeded */

		set_sm_state(ENGINE_DO_REGISTRATION);

		return;

	}



	err = lwm2m_socket_start(client.ctx);

	if (err) {

		LOG_ERR("Failed to start socket %d", err);

		/*

		 * keep this state until lifetime/retry count exceeds. Renew

		 * sm state to set retry_delay etc ...

		 */

		set_sm_state(ENGINE_NETWORK_ERROR);

		return;

	}



	set_sm_state(ENGINE_UPDATE_REGISTRATION);

}



static void lwm2m_rd_client_service(struct k_work *work)
@@ -1144,6 +1195,10 @@ static void lwm2m_rd_client_service(struct k_work *work) 
			sm_registration_done();

			break;



		case ENGINE_UPDATE_REGISTRATION:

			sm_update_registration();

			break;



		case ENGINE_UPDATE_SENT:

			/* wait update to be done or abort */

			break;

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