net: doc: Minor improvements on enabling application libraries

doc/_scripts/redirects.py

@@ -16,6 +16,7 @@
     ('application/index', 'develop/application/index'),
     ('boards/x86/ehl_crb/doc/index', 'boards/x86/intel_ehl/doc/index'),
     ('boards/x86/rpl_crb/doc/index', 'boards/x86/intel_rpl/doc/index'),
+    ('connectivity/networking/networking-api-usage', 'connectivity/networking/api/index'),
     ('development_process/code_flow', 'project/code_flow'),
     ('development_process/index', 'project/index'),
     ('development_process/issues', 'project/issues'),

doc/connectivity/networking/api/coap.rst

@@ -17,7 +17,8 @@ that support CoAP's features. For more information about the protocol
 itself, see `IETF RFC7252 The Constrained Application Protocol <https://tools.ietf.org/html/rfc7252>`_.
 
 Zephyr provides a CoAP library which supports client and server roles.
-The library is configurable as per user needs. The Zephyr CoAP library
+The library can be enabled with :kconfig:option:`CONFIG_COAP` Kconfig option and
+is configurable as per user needs. The Zephyr CoAP library
 is implemented using plain buffers. Users of the API create sockets
 for communication and pass the buffer to the library for parsing and other
 purposes. The library itself doesn't create any sockets for users.

doc/connectivity/networking/api/coap_client.rst

@@ -11,6 +11,7 @@ Overview
 ********
 
 The CoAP client library allows application to send CoAP requests and parse CoAP responses.
+The library can be enabled with :kconfig:option:`CONFIG_COAP_CLIENT` Kconfig option.
 The application is notified about the response via a callback that is provided to the API
 in the request. The CoAP client handles the communication over sockets.
 As the CoAP client doesn't create socket it is using, the application is responsible for creating

doc/connectivity/networking/api/http.rst

@@ -13,6 +13,7 @@ Overview
 The HTTP client library allows you to send HTTP requests and
 parse HTTP responses. The library communicates over the sockets
 API but it does not create sockets on its own.
+It can be enabled with :kconfig:option:`CONFIG_HTTP_CLIENT` Kconfig option.
 
 The application must be responsible for creating a socket and passing it to the library.
 Therefore, depending on the application's needs, the library can communicate over

doc/connectivity/networking/api/index.rst

@@ -3,6 +3,17 @@
 Networking APIs
 ###############
 
+Zephyr provides support for the standard BSD socket APIs (defined in
+:zephyr_file:`include/zephyr/net/socket.h`) for the applications to
+use. See :ref:`BSD socket API <bsd_sockets_interface>` for more details.
+
+Apart of the standard API, Zephyr provides a set of custom networking APIs and
+libraries for the application to use. See the list below for details.
+
+.. note::
+   The legacy connectivity API in :zephyr_file:`include/zephyr/net/net_context.h`
+   should not be used by applications.
+
 .. toctree::
    :maxdepth: 2
 

doc/connectivity/networking/api/lwm2m.rst

@@ -25,6 +25,8 @@ REST API to manage various interfaces with the client.
 LwM2M uses a simple resource model with the core set of objects and resources
 defined in the specification.
 
+The LwM2M library can be enabled with :kconfig:option:`CONFIG_LWM2M` Kconfig option.
+
 Example LwM2M object and resources: Device
 ******************************************
 

doc/connectivity/networking/api/mqtt.rst

@@ -16,7 +16,8 @@ publish/subscribe messaging transport for machine-to-machine communication.
 For more information about the protocol itself, see http://mqtt.org/.
 
 Zephyr provides an MQTT client library built on top of BSD sockets API. The
-library is configurable at a per-client basis, with support for MQTT versions
+library can be enabled with :kconfig:option:`CONFIG_MQTT_LIB` Kconfig option and
+is configurable at a per-client basis, with support for MQTT versions
 3.1.0 and 3.1.1. The Zephyr MQTT implementation can be used with either plain
 sockets communicating over TCP, or with secure sockets communicating over
 TLS. See :ref:`bsd_sockets_interface` for more information about Zephyr sockets.

doc/connectivity/networking/api/mqtt_sn.rst

@@ -17,7 +17,8 @@ over any message-based transport. Originally, it was mainly created with ZigBee
 but others like Bluetooth, UDP or even a UART can be used just as well.
 
 Zephyr provides an MQTT-SN client library built on top of BSD sockets API. The
-library is configurable at a per-client basis, with support for MQTT-SN version
+library can be enabled with :kconfig:option:`CONFIG_MQTT_SN_LIB` Kconfig option
+and is configurable at a per-client basis, with support for MQTT-SN version
 1.2. The Zephyr MQTT-SN implementation can be used with any message-based transport,
 but support for UDP is already built-in.
 

doc/connectivity/networking/api/sockets.rst

@@ -57,6 +57,10 @@ there is a table mapping file descriptors to internal object pointers.
 The file descriptor table is used by the BSD Sockets API even if the rest
 of the POSIX subsystem (filesystem, stdin/stdout) is not enabled.
 
+See :zephyr:code-sample:`sockets-echo-server` and :zephyr:code-sample:`sockets-echo-client`
+sample applications to learn how to create a simple server or client BSD socket based
+application.
+
 .. _secure_sockets_interface:
 
 Secure Sockets

doc/connectivity/networking/api/tftp.rst

@@ -3,6 +3,12 @@
 TFTP
 ####
 
+Zephyr provides a simple TFTP client library that can enabled with
+:kconfig:option:`CONFIG_MQTT_SN_LIB` Kconfig option.
+
+See :zephyr:code-sample:`TFTP client sample application <tftp-client>` for
+more information about the library usage.
+
 API Reference
 *************
 

doc/connectivity/networking/index.rst

@@ -12,7 +12,6 @@ operation of the stacks and how they were implemented.
 
    overview.rst
    net-stack-architecture.rst
-   networking-api-usage.rst
    networking_with_host.rst
    network_monitoring.rst
    api/index.rst