net: lwm2m: Allow changing the protocol version to 1.1

This is a bare minimal changes to tell the server that we are using
LwM2M 1.1 version. Queue-mode parameter has changed between 1.0 and
1.1 so it must be changed in the same time.

Other 1.1 features may follow on separate commits. This is still
an experimental feature that allows developing and testing of
1.1 features.

Signed-off-by: Seppo Takalo <seppo.takalo@nordicsemi.no>

subsys/net/lib/lwm2m/Kconfig

@@ -17,6 +17,21 @@ module-dep = LOG
 module-str = Log level for LWM2M library
 source "subsys/net/Kconfig.template.log_config.net"
 
+choice
+	prompt "LwM2M protocol version"
+	default LWM2M_VERSION_1_0
+	help
+	  Select which version of the LwM2M protocol is used
+
+config LWM2M_VERSION_1_0
+	bool "LwM2M version 1.0"
+
+config LWM2M_VERSION_1_1
+	bool "LwM2M version 1.1 [EXPERIMENTAL]"
+	select EXPERIMENTAL
+
+endchoice
+
 config LWM2M_DTLS_SUPPORT
 	bool "Enable DTLS support in the LwM2M client"
 	select TLS_CREDENTIALS
@@ -25,7 +40,8 @@ config LWM2M_DTLS_SUPPORT
 
 choice
 	prompt "LwM2M Security object version"
-	default LWM2M_SECURITY_OBJECT_VERSION_1_0
+	default LWM2M_SECURITY_OBJECT_VERSION_1_0 if LWM2M_VERSION_1_0
+	default LWM2M_SECURITY_OBJECT_VERSION_1_1 if LWM2M_VERSION_1_1
 	help
 	  Select which version of the security object should be used.
 
@@ -40,7 +56,8 @@ endchoice
 
 choice
 	prompt "LwM2M Server object version"
-	default LWM2M_SERVER_OBJECT_VERSION_1_0
+	default LWM2M_SERVER_OBJECT_VERSION_1_0 if LWM2M_VERSION_1_0
+	default LWM2M_SERVER_OBJECT_VERSION_1_1 if LWM2M_VERSION_1_1
 	help
 	  Select which version of the Server object should be used.
 
@@ -273,7 +290,8 @@ config LWM2M_CONN_MON_OBJ_SUPPORT
 
 choice
 	prompt "LwM2M Connectivity Monitor object version"
-	default LWM2M_CONNMON_OBJECT_VERSION_1_0
+	default LWM2M_CONNMON_OBJECT_VERSION_1_0 if LWM2M_VERSION_1_0
+	default LWM2M_CONNMON_OBJECT_VERSION_1_2 if LWM2M_VERSION_1_1
 	depends on LWM2M_CONN_MON_OBJ_SUPPORT
 	help
 	  Select Which version of the Connectivity Monitor object should be used.

subsys/net/lib/lwm2m/lwm2m_engine.c

@@ -67,6 +67,8 @@ LOG_MODULE_REGISTER(LOG_MODULE_NAME);
 #define	COAP_OPTION_BUF_LEN	13
 #endif
 
+#define BINDING_OPT_MAX_LEN	3 /* "UQ" */
+#define QUEUE_OPT_MAX_LEN	2 /* "Q" */
 #define MAX_TOKEN_LEN		8
 
 struct observe_node {
@@ -2011,12 +2013,24 @@ int lwm2m_engine_update_observer_max_period(const char *pathstr, uint32_t period
 }
 
 void lwm2m_engine_get_binding(char *binding)
+{
+	/* Defaults to UDP. */
+	strncpy(binding, "U", BINDING_OPT_MAX_LEN);
+#if CONFIG_LWM2M_VERSION_1_0
+	/* In LwM2M 1.0 binding and queue mode are in same parameter */
+	char queue[QUEUE_OPT_MAX_LEN];
+
+	lwm2m_engine_get_queue_mode(queue);
+	strncat(binding, queue, QUEUE_OPT_MAX_LEN);
+#endif
+}
+
+void lwm2m_engine_get_queue_mode(char *queue)
 {
 	if (IS_ENABLED(CONFIG_LWM2M_QUEUE_MODE_ENABLED)) {
-		strcpy(binding, "UQ");
+		strncpy(queue, "Q", QUEUE_OPT_MAX_LEN);
 	} else {
-		/* Defaults to UDP. */
+		strncpy(queue, "", QUEUE_OPT_MAX_LEN);
-		strcpy(binding, "U");
 	}
 }
 

subsys/net/lib/lwm2m/lwm2m_engine.h

@@ -11,7 +11,11 @@
 #include "lwm2m_object.h"
 
 #define LWM2M_PROTOCOL_VERSION_MAJOR 1
+#if CONFIG_LWM2M_VERSION_1_1
+#define LWM2M_PROTOCOL_VERSION_MINOR 1
+#else
 #define LWM2M_PROTOCOL_VERSION_MINOR 0
+#endif
 
 #define LWM2M_PROTOCOL_VERSION_STRING STRINGIFY(LWM2M_PROTOCOL_VERSION_MAJOR) \
 				      "." \
@@ -123,6 +127,7 @@ int lwm2m_engine_get_resource(const char *pathstr,
 			      struct lwm2m_engine_res **res);
 
 void lwm2m_engine_get_binding(char *binding);
+void lwm2m_engine_get_queue_mode(char *queue);
 
 size_t lwm2m_engine_get_opaque_more(struct lwm2m_input_context *in,
 				    uint8_t *buf, size_t buflen,

subsys/net/lib/lwm2m/lwm2m_rd_client.c

@@ -67,8 +67,8 @@ LOG_MODULE_REGISTER(LOG_MODULE_NAME);
 
 #define CLIENT_EP_LEN		CONFIG_LWM2M_RD_CLIENT_ENDPOINT_NAME_MAX_LENGTH
 
-/* Up to 3 characters + NULL */
+#define CLIENT_BINDING_LEN sizeof("U")
-#define CLIENT_BINDING_LEN sizeof("UQS")
+#define CLIENT_QUEUE_LEN sizeof("Q")
 
 /* The states for the RD client state machine */
 /*
@@ -712,6 +712,7 @@ static int sm_send_registration(bool send_obj_support_data,
 	struct lwm2m_message *msg;
 	int ret;
 	char binding[CLIENT_BINDING_LEN];
+	char queue[CLIENT_QUEUE_LEN];
 
 	msg = lwm2m_get_message(client.ctx);
 	if (!msg) {
@@ -793,8 +794,9 @@ static int sm_send_registration(bool send_obj_support_data,
 	}
 
 	lwm2m_engine_get_binding(binding);
-	/* UDP is a default binding, no need to add option if UDP is used. */
+	lwm2m_engine_get_queue_mode(queue);
-	if ((!sm_is_registered() && strcmp(binding, "U") != 0)) {
+	/* UDP is a default binding, no need to add option if UDP without queue is used. */
+	if ((!sm_is_registered() && (strcmp(binding, "U") != 0 || strcmp(queue, "Q") == 0))) {
 		snprintk(query_buffer, sizeof(query_buffer) - 1,
 			 "b=%s", binding);
 
@@ -804,6 +806,20 @@ static int sm_send_registration(bool send_obj_support_data,
 		if (ret < 0) {
 			goto cleanup;
 		}
+
+#if CONFIG_LWM2M_VERSION_1_1
+		/* In LwM2M 1.1, queue mode is a separate parameter */
+		uint16_t len = strlen(queue);
+
+		if (len) {
+			ret = coap_packet_append_option(
+				&msg->cpkt, COAP_OPTION_URI_QUERY,
+				queue, len);
+			if (ret < 0) {
+				goto cleanup;
+			}
+		}
+#endif
 	}
 
 	if (send_obj_support_data) {
@@ -830,6 +846,7 @@ static int sm_send_registration(bool send_obj_support_data,
 	return 0;
 
 cleanup:
+	LOG_ERR("error %d when sending registration message", ret);
 	lwm2m_reset_message(msg, true);
 	return ret;
 }