Add property API to NetworkInterface

Property API allows application to ask network specific properties
from the NetworkInterface. Queried information can be used to avoid
network congestion by adjusting transmission jitter and retry
timeouts.

Author: Arto Kinnunen

features/nanostack/mbed-mesh-api/mbed-mesh-api/MeshInterfaceNanostack.h

@@ -140,6 +140,9 @@ class InterfaceNanostack : public virtual NetworkInterface {
      */
     virtual nsapi_error_t set_file_system_root_path(const char *root_path);
 
+    /** @copydoc NetworkInterface::get_interface_property */
+    virtual nsapi_error_t get_interface_property(nsapi_size_t data_amount, nsapi_size_t *jitter);
+
     /** Get the interface ID
      *  @return  Interface identifier
      */

features/nanostack/mbed-mesh-api/source/MeshInterfaceNanostack.cpp

@@ -19,6 +19,7 @@
 #include "NanostackLockGuard.h"
 #include "mesh_system.h"
 #include "nanostack/net_interface.h"
+#include "nanostack/ns_property.h"
 #include "thread_management_if.h"
 #include "ip6string.h"
 #include "mbed_error.h"
@@ -232,6 +233,19 @@ nsapi_error_t InterfaceNanostack::set_file_system_root_path(const char *root_pat
     return MESH_ERROR_UNKNOWN;
 }
 
+nsapi_error_t InterfaceNanostack::get_interface_property(nsapi_size_t data_amount, nsapi_size_t *jitter) {
+    ns_properties_t ns_properties;
+
+    ns_properties.data_amount = data_amount;
+
+    if (ns_property_get(get_interface_id(), &ns_properties) == 0) {
+        *jitter = ns_properties.tx_jitter;
+        return NSAPI_ERROR_OK;
+    }
+
+    return NSAPI_ERROR_NO_CONNECTION;
+}
+
 #if !DEVICE_802_15_4_PHY
 MBED_WEAK MeshInterface *MeshInterface::get_target_default_instance()
 {

features/netsocket/NetworkInterface.cpp

@@ -174,3 +174,7 @@ nsapi_error_t NetworkInterface::set_blocking(bool blocking)
     return NSAPI_ERROR_UNSUPPORTED;
 }
 
+nsapi_error_t NetworkInterface::get_interface_property(unsigned int data_amount, unsigned int *jitter)
+{
+    return NSAPI_ERROR_UNSUPPORTED;
+}

features/netsocket/NetworkInterface.h

@@ -378,6 +378,15 @@ class NetworkInterface: public DNS {
      */
     virtual nsapi_error_t set_blocking(bool blocking);
 
+    /** Get suggested data transmission jitter from underlying network interface.
+     *
+     * @param data_amount Amount of data to be sent
+     * @param jitter Address to location where suggested jitter value is written
+     * @return NSAPI_ERROR_OK on success
+     * @return NSAPI_ERROR_UNSUPPORTED, NSAPI_ERROR_NO_CONNECTION
+     */
+    virtual nsapi_error_t get_interface_property(unsigned int data_amount, unsigned int *jitter);
+
     /** Return pointer to an EthInterface.
      * @return Pointer to requested interface type or NULL if this class doesn't implement the interface.
      */