modules: main: Add CDDL CBOR encoding of device shadow

simensrostad · jtguggedal · commit 26543a44990c · 2025-03-18T18:17:48.000+01:00
Add missing CDDL CBOR decoding of incoming data.
Used to decode update interval set in cloud.

Tests are updated to check new configuration, in addition
to using some convenience functions for expected events.

Signed-off-by: Simen S. Røstad &lt;simen.rostad@nordicsemi.no&gt;
diff --git a/app/src/cbor/CMakeLists.txt b/app/src/cbor/CMakeLists.txt
@@ -6,3 +6,31 @@
 
 target_sources(app PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/cbor_helper.c)
 target_include_directories(app PRIVATE .)
+
+# generate encoder code using zcbor
+set(zcbor_command
+        zcbor code # Invoke code generation
+	--cddl ${CMAKE_CURRENT_SOURCE_DIR}/device_shadow.cddl
+	--decode # Generate decoding functions
+	--short-names # Attempt to make generated symbol names shorter (at the risk of collision)
+	-t config-object # Create a public API for decoding the "config-object" type from the cddl file
+	--output-cmake device_shadow.cmake # The generated cmake file will be placed here
+)
+execute_process(COMMAND ${zcbor_command}
+		WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+		COMMAND_ERROR_IS_FATAL ANY)
+
+# Include the cmake file generated by zcbor. It adds the
+# generated code and the necessary zcbor C code files.
+include(${CMAKE_CURRENT_BINARY_DIR}/device_shadow.cmake)
+
+# Ensure that the cmake reconfiguration is triggerred everytime the cddl file changes.
+# This ensures that the codec generation is triggered.
+set_property(
+	DIRECTORY
+	PROPERTY
+	CMAKE_CONFIGURE_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/device_shadow.cddl
+)
+
+zephyr_link_libraries(device_shadow)
+target_link_libraries(device_shadow PRIVATE zephyr_interface)
diff --git a/app/src/cbor/cbor_helper.c b/app/src/cbor/cbor_helper.c
@@ -3,15 +3,23 @@
  *
  * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
  */
-
-#include <zephyr/logging/log.h>
-
-LOG_MODULE_DECLARE(main, CONFIG_APP_LOG_LEVEL);
+#include <errno.h>
+#include "device_shadow_decode.h"
 
 int get_update_interval_from_cbor_response(const uint8_t *cbor,
 					   size_t len,
 					   uint64_t *interval_sec)
 {
-	*interval_sec = 1800;
+	struct config_object object = { 0 };
+	size_t not_used;
+
+	int err = cbor_decode_config_object(cbor, len, &object, &not_used);
+
+	if (err) {
+		return -EFAULT;
+	}
+
+	*interval_sec = object.update_interval;
+
 	return 0;
 }
diff --git a/app/src/cbor/cbor_helper.h b/app/src/cbor/cbor_helper.h
@@ -6,6 +6,18 @@
 
 #include <zephyr/types.h>
 
+/**
+ * @brief Get the update interval from a CBOR buffer.
+ *
+ * @param[in]  cbor         The CBOR buffer.
+ * @param[in]  len          The length of the CBOR buffer.
+ * @param[out] interval_sec The update interval in seconds.
+ *
+ * @returns 0 If the operation was successful.
+ *	    Otherwise, a (negative) error code is returned.
+ * @retval -EFAULT if the CBOR buffer is invalid.
+ *
+ */
 int get_update_interval_from_cbor_response(const uint8_t *cbor,
 					   size_t len,
 					   uint64_t *interval_sec);
diff --git a/app/src/cbor/device_shadow.cddl b/app/src/cbor/device_shadow.cddl
@@ -1,53 +1,5 @@
-; Define the basic structure of the JSON object
-
-; The 'any' type is used in this schema to allow forward compatibility.
-; They are inserted into maps that may contain additional fields in the future.
-; This prevents cbor decoding from failing in the field when the cloud side has new fields.
-app-object = {
-    ? "nrfcloud_mqtt_topic_prefix": tstr,
-    ? "pairing": pairing-type,
-    ? "lwm2m": lwm2m-map,
-    * tstr => any
-}
-
-; Define the pairing object with nested topics
-pairing-type = {
-    "state": tstr,
-    "topics": {
-        "d2c": tstr,
-        "c2d": tstr,
-        * tstr => any
-    },
-    * any => any
-}
-
-lwm2m-map = {
-  ? "14240:1.0": led,
-  ? "14301:1.0": config,
-  * tstr => any
-}
-
-led = {
-  "0": led_inner_object,
-  * tstr => any
-}
-
-led_inner_object = {
-  ? "0": int .size 4,
-  ? "1": int .size 4,
-  ? "2": int .size 4,
-  "99": int .size 8,
-  * tstr => any
-}
-
-config = {
-  "0": config_inner_object,
-  * tstr => any
-}
-
-config_inner_object = {
-  ? "0": int .size 8,
-  ? "1": bool,
-  "99": int .size 8,
-  * tstr => any
+config-object = {
+    "config": {
+        "update_interval": uint .size 8
+    }
 }
diff --git a/app/src/main.c b/app/src/main.c
@@ -106,14 +106,14 @@ static void fota_rebooting_entry(void *o);
 enum state {
 	/* Normal operation */
 	STATE_RUNNING,
+		/* Disconnected from the cloud, no triggers are sent */
+		STATE_IDLE,
 		/* Triggers are periodically sent at a configured interval */
 		STATE_TRIGGERING,
 			/* Requesting location from the location module */
 			STATE_REQUESTING_LOCATION,
 			/* Requesting sensor values and polling for downlink data */
 			STATE_REQUESTING_SENSORS_AND_POLLING,
-		/* Disconnected from the network, no triggers are sent */
-		STATE_IDLE,
 	/* Ongoing FOTA process, triggers are blocked */
 	STATE_FOTA,
 		/* FOTA image is being downloaded */
@@ -157,6 +157,13 @@ static const struct smf_state states[] = {
 		running_run,
 		NULL,
 		NULL,
+		&states[STATE_IDLE]
+	),
+	[STATE_IDLE] = SMF_CREATE_STATE(
+		idle_entry,
+		idle_run,
+		NULL,
+		&states[STATE_RUNNING],
 		NULL
 	),
 	[STATE_TRIGGERING] = SMF_CREATE_STATE(
@@ -180,13 +187,6 @@ static const struct smf_state states[] = {
 		&states[STATE_TRIGGERING],
 		NULL
 	),
-	[STATE_IDLE] = SMF_CREATE_STATE(
-		idle_entry,
-		idle_run,
-		NULL,
-		&states[STATE_RUNNING],
-		NULL
-	),
 	[STATE_FOTA] = SMF_CREATE_STATE(
 		fota_entry,
 		fota_run,
@@ -460,7 +460,7 @@ static void triggering_run(void *o)
 								     msg.response.buffer_data_len,
 								     &state_object->interval_sec);
 			if (err) {
-				LOG_ERR("json_parse, error: %d", err);
+				LOG_ERR("get_update_interval_from_cbor_response, error: %d", err);
 				SEND_FATAL_ERROR();
 				return;
 			}
diff --git a/tests/module/main/CMakeLists.txt b/tests/module/main/CMakeLists.txt
@@ -11,7 +11,7 @@ project(app_module_test)
 
 test_runner_generate(src/main.c)
 
-set(ASSET_TRACKER_TEMPLATE_DIR ../../..)
+set(ASSET_TRACKER_TEMPLATE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../..)
 
 target_sources(app
 	PRIVATE
@@ -67,3 +67,36 @@ target_compile_definitions(app PRIVATE
 	-DZEPHYR_INCLUDE_SYS_REBOOT_H_
 	-DCONFIG_APP_REQUEST_NETWORK_QUALITY=1
 )
+
+# CONSIDER: REUSING THE CODEC GENERATION LOGIC FROM THE MAIN APP
+
+# generate encoder code using zcbor
+set(zcbor_command
+        zcbor code # Invoke code generation
+	--cddl ${APPLICATION_SOURCE_DIR}/../../../app/src/cbor/device_shadow.cddl
+	--decode # Generate decoding functions
+	--short-names # Attempt to make generated symbol names shorter (at the risk of collision)
+	-t config-object # Create a public API for decoding the "config-object" type from the cddl file
+	--output-cmake device_shadow.cmake # The generated cmake file will be placed here
+)
+
+message(WARNING ${zcbor_command})
+
+execute_process(COMMAND ${zcbor_command}
+		WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+		COMMAND_ERROR_IS_FATAL ANY)
+
+# Include the cmake file generated by zcbor. It adds the
+# generated code and the necessary zcbor C code files.
+include(${CMAKE_CURRENT_BINARY_DIR}/device_shadow.cmake)
+
+# # Ensure that the cmake reconfiguration is triggerred everytime the cddl file changes.
+# # This ensures that the codec generation is triggered.
+# set_property(
+# 	DIRECTORY
+# 	PROPERTY
+# 	CMAKE_CONFIGURE_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/device_shadow.cddl
+# )
+
+zephyr_link_libraries(device_shadow)
+target_link_libraries(device_shadow PRIVATE zephyr_interface)
diff --git a/tests/module/main/src/checks.c b/tests/module/main/src/checks.c
diff --git a/tests/module/main/src/checks.h b/tests/module/main/src/checks.h
diff --git a/tests/module/main/src/main.c b/tests/module/main/src/main.c
