net: lwm2m: Allow setting RD context without starting

When tests control the LwM2M client entirely through
shell, we should be able to set the RD client context
from the application without causing RD client to
start registration.

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

subsys/net/lib/lwm2m/lwm2m_rd_client.c

@@ -1708,6 +1708,11 @@ struct lwm2m_ctx *lwm2m_rd_client_ctx(void)
 	return client.ctx;
 }
 
+void lwm2m_rd_client_set_ctx(struct lwm2m_ctx *ctx)
+{
+	client.ctx = ctx;
+}
+
 int lwm2m_rd_client_connection_resume(struct lwm2m_ctx *client_ctx)
 {
 	if (client.ctx != client_ctx) {

subsys/net/lib/lwm2m/lwm2m_rd_client.h

@@ -66,4 +66,14 @@ struct lwm2m_message *lwm2m_get_ongoing_rd_msg(void);
  */
 int lwm2m_rd_client_server_disabled(uint16_t inst_id);
 
+/**
+ * @brief Set client context for the RD client.
+ *
+ * For testing purposes, it might be required to set the client context
+ * without starting the RD client.
+ *
+ * @param ctx context
+ */
+void lwm2m_rd_client_set_ctx(struct lwm2m_ctx *ctx);
+
 #endif /* LWM2M_RD_CLIENT_H */

tests/net/lib/lwm2m/interop/src/lwm2m-client.c

@@ -16,6 +16,7 @@ LOG_MODULE_REGISTER(LOG_MODULE_NAME);
 #include <zephyr/drivers/sensor.h>
 #include <zephyr/net/lwm2m.h>
 #include <zephyr/net/socket.h>
+#include "lwm2m_rd_client.h"
 
 #define APP_BANNER "Run LWM2M client"
 
@@ -246,9 +247,11 @@ int main(void)
 
 	client.tls_tag = 1;
 	client.set_socketoptions = set_socketoptions;
+	client.event_cb = rd_client_event;
+	client.observe_cb = observe_cb;
+	client.sock_fd = -1;
 
-	lwm2m_rd_client_start(&client, CONFIG_BOARD, 0, rd_client_event, observe_cb);
+	lwm2m_rd_client_set_ctx(&client);
-	lwm2m_rd_client_stop(&client, rd_client_event, false);
 
 	return 0;
 }