Add NetworkInterface::get_default_instance()

Provide an initial framework to make it easier to find a default network
interface.

Author: kjbracey

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

@@ -160,3 +160,13 @@ bool LoWPANNDInterface::getRouterIpAddress(char *address, int8_t len)
 {
     return _interface->get_gateway(address, len);
 }
+
+#define LOWPAN 0x2345
+#if MBED_CONF_NSAPI_DEFAULT_MESH_TYPE == LOWPAN && DEVICE_802_15_4_PHY
+MBED_WEAK MeshInterface *MeshInterface::get_default_instance()
+{
+    static LoWPANNDInterface lowpan(NanostackRfPhy::get_default_instance());
+
+    return lowpan;
+}
+#endif

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

@@ -182,3 +182,10 @@ nsapi_error_t InterfaceNanostack::set_blocking(bool blocking)
     _blocking = blocking;
     return NSAPI_ERROR_OK;
 }
+
+#if !DEVICE_802_15_4_PHY
+MBED_WEAK MeshInterface *MeshInterface::get_target_default_instance()
+{
+    return NULL;
+}
+#endif

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

@@ -231,3 +231,13 @@ mesh_error_t Nanostack::ThreadInterface::device_pskd_set(const char *pskd)
 {
     return (mesh_error_t)thread_tasklet_device_pskd_set(pskd);
 }
+
+#define THREAD 0x2345
+#if MBED_CONF_NSAPI_DEFAULT_MESH_TYPE == THREAD && DEVICE_802_15_4_PHY
+MBED_WEAK MeshInterface *MeshInterface::get_target_default_instance()
+{
+    static ThreadInterface thread(NanostackRfPhy::get_default_instance());
+
+    return thread;
+}
+#endif

features/nanostack/nanostack-interface/NanostackRfPhy.h

@@ -24,6 +24,13 @@
 class NanostackRfPhy : public NanostackPhy {
 public:
 
+    /** Return the default on-board NanostackRfPhy
+     *
+     * Returns the default on-board NanostackRfPhy - this will be target-specific, and
+     * may not be available on all targets.
+     */
+    static NanostackRfPhy &get_default_instance();
+
     /** Register this physical interface with Nanostack
      *
      *  @return         Device driver ID or a negative error

features/netsocket/CellularBase.h

@@ -26,6 +26,17 @@ class CellularBase: public NetworkInterface {
 
 public:
 
+    /** Get the default Cellular interface.
+     *
+     * This is provided as a weak method so applications can override.
+     * Default behaviour is to get the target's default interface, if
+     * any.
+     *
+     * @return pointer to interface, if any
+     */
+
+    static CellularBase *get_default_instance();
+
     /** Set the Cellular network credentials
      *
      *  Please check documentation of connect() for default behaviour of APN settings.
@@ -104,6 +115,17 @@ class CellularBase: public NetworkInterface {
     virtual CellularBase *cellularBase() {
         return this;
     }
+
+protected:
+    /** Get the target's default Cellular interface.
+     *
+     * This is provided as a weak method so targets can override. The
+     * default implementation configures and returns the OnBoardModemInterface
+     * if available.
+     *
+     * @return pointer to interface, if any
+     */
+    static CellularBase *get_target_default_instance();
 };
 
 #endif //CELLULAR_BASE_H

features/netsocket/EthInterface.h

@@ -29,9 +29,33 @@
  */
 class EthInterface : public virtual NetworkInterface
 {
+public:
+
     virtual EthInterface *ethInterface() {
         return this;
     }
+
+    /** Get the default Ethernet interface.
+     *
+     * This is provided as a weak method so applications can override.
+     * Default behaviour is to get the target's default interface, if
+     * any.
+     *
+     * @return pointer to interface, if any
+     */
+    static EthInterface *get_default_instance();
+
+protected:
+
+    /** Get the target's default Ethernet interface.
+     *
+     * This is provided as a weak method so targets can override. The
+     * default implementation will invoke EthernetInterface with the
+     * default EMAC and default network stack, if DEVICE_EMAC is set.
+     *
+     * @return pointer to interface, if any
+     */
+    static EthInterface *get_target_default_instance();
 };
 
 

features/netsocket/EthernetInterface.cpp

@@ -0,0 +1,34 @@
+/* LWIP implementation of NetworkInterfaceAPI
+ * Copyright (c) 2015 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "EthernetInterface.h"
+
+/* No actual interface implementation here, as EthernetInterface is
+ * just an EMACInterface. But we can be the default EthInterface - step up
+ * if the target has a default EMAC.
+ */
+#if DEVICE_EMAC
+MBED_WEAK EthInterface *EthInterface::get_target_default_instance()
+{
+    static EthernetInterface ethernet;
+    return &ethernet;
+}
+#else
+MBED_WEAK EthInterface *EthInterface::get_target_default_instance()
+{
+    return NULL;
+}
+#endif

features/netsocket/MeshInterface.h

@@ -29,9 +29,33 @@
  */
 class MeshInterface : public virtual NetworkInterface
 {
+public:
+
     virtual MeshInterface *meshInterface() {
         return this;
     }
+
+    /** Get the default Mesh interface.
+     *
+     * This is provided as a weak method so applications can override.
+     * Default behaviour is to get the target's default interface, if
+     * any.
+     *
+     * @return pointer to interface, if any
+     */
+    static MeshInterface *get_default_instance();
+
+protected:
+
+    /** Get the target's default Mesh interface.
+     *
+     * This is provided as a weak method so targets can override. The
+     * default implementation will invoke LoWPANNDInterface or ThreadInterface
+     * with the default NanostackRfPhy.
+     *
+     * @return pointer to interface, if any
+     */
+    static MeshInterface *get_target_default_instance();
 };
 
 

features/netsocket/NetworkInterface.h

@@ -39,10 +39,46 @@ class EMACInterface;
 class NetworkInterface: public DNS {
 public:
 
-
-
     virtual ~NetworkInterface() {};
 
+    /** Return the default network interface
+     *
+     * Returns the default network interface, as determined by JSON option
+     * target.network-default-interface-type or other overrides.
+     *
+     * The type of the interface returned can be tested via the ethInterface()
+     * etc downcasts.
+     *
+     * The default behaviour is to return the default interface for the
+     * interface type specified by target.network-default-interface-type. Targets
+     * should set this in their targets.json to guide default selection,
+     * and applications may override.
+     *
+     * The interface returned should be already configured for use such that its
+     * connect() method works with no parameters. For connection types needing
+     * configuration, settings should normally be obtained from JSON - the
+     * settings for the core types are under the "nsapi" JSON config tree.
+     *
+     * The list of possible settings for default interface type is open-ended,
+     * as is the number of possible providers. Core providers are:
+     *
+     * * ETHERNET: EthernetInterface, using default EMAC and OnboardNetworkStack
+     * * MESH: ThreadInterface or LoWPANNDInterface, using default NanostackRfPhy
+     * * CELLULAR: OnboardModemInterface
+     * * WIFI: None - always provided by a specific class
+     *
+     * Specific drivers may be activated by other settings of the
+     * default-network-interface-type configuration.  This will depend on the
+     * target and the driver. For example a board may have its default setting
+     * as "AUTO" which causes it to autodetect an Ethernet cable. This should
+     * be described in the target's documentation.
+     *
+     * An application can override all target settings by implementing
+     * NetworkInterface::get_default_instance() themselves - the default
+     * definition is weak, and calls get_target_default_instance().
+     */
+    static NetworkInterface *get_default_instance();
+
     /** Get the local MAC address
      *
      *  Provided MAC address is intended for info or debug purposes and
@@ -247,6 +283,37 @@ class NetworkInterface: public DNS {
      *  @return The underlying NetworkStack object
      */
     virtual NetworkStack *get_stack() = 0;
+
+    /** Get the target's default network instance.
+     *
+     * This method can be overridden by the target. Default implementations
+     * are provided weakly by various subsystems as described in
+     * NetworkInterface::get_default_instance(), so targets should not
+     * need to override in simple cases.
+     *
+     * If a target has more elaborate interface selection, it can completely
+     * override this behaviour by implementing
+     * NetworkInterface::get_target_default_instance() themselves, either
+     * unconditionally, or for a specific network-default-interface-type setting
+     *
+     * For example, a device with both Ethernet and Wi-fi could be set up its
+     * target so that:
+     *    * DEVICE_EMAC is set, and it provides EMAC::get_default_instance(),
+     *      which means EthernetInterface provides EthInterface::get_target_instance()
+     *      based on that EMAC.
+     *    * It provides WifiInterface::get_target_default_instance().
+     *    * The core will route NetworkInterface::get_default_instance() to
+     *      either of those if network-default-interface-type is set to
+     *      ETHERNET or WIFI.
+     *    * The board overrides NetworkInterface::get_target_default_instance()
+     *      if network-default-interface-type is set to AUTO. This returns
+     *      either EthInterface::get_default_instance() or WiFIInterface::get_default_instance()
+     *      depending on a cable detection.
+     *
+     *
+     * performs the search described by get_default_instance.
+     */
+    static NetworkInterface *get_target_default_instance();
 };