2017-02-02 22:27:05 +08:00
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.. _ip_stack_overview:
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Overview
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########
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Supported Features
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******************
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2017-04-04 22:54:14 +08:00
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The networking IP stack is modular and highly configurable via build-time
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configuration options. You can minimize system memory consumption by enabling
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only those network features required by your application. Almost all features
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can be disabled if not needed.
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* **IPv6** The support for IPv6 is enabled by default. Various IPv6 sub-options
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can be enabled or disabled depending on networking needs.
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* Developer can set the number of unicast and multicast IPv6 addresses that
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are active at the same time.
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* The IPv6 address for the device can be set either statically or
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dynamically using SLAAC (Stateless Address Auto Configuration) (RFC 4862).
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* The system also supports multiple IPv6 prefixes and the maximum
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IPv6 prefix count can be configured at build time.
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* The IPv6 neighbor cache can be disabled if not needed, and its size can be
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configured at build time.
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* The IPv6 neighbor discovery support (RFC 4861) is enabled by default.
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* Multicast Listener Discovery v2 support (RFC 3810) is enabled by default.
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* IPv6 header compression (6lo) is available for IPv6 connectivity for
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Bluetooth IPSP (RFC 7668) and IEEE 802.15.4 networks (RFC 4944).
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* **IPv4** The legacy IPv4 is supported by the networking stack. It cannot be
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used by IEEE 802.15.4 or Bluetooth IPSP as those network technologies support
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only IPv6. IPv4 can be used in ethernet based networks. By default IPv4
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support is disabled.
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* DHCP (Dynamic Host Configuration Protocol) client is supported (RFC 2131).
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* The IPv4 address can also be configured manually. Static IPv4 addresses
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are supported by default.
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* **Dual stack support.** The networking stack allows a developer to configure
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the system to use both IPv6 and IPv4 at the same time.
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* **UDP** User Datagram Protocol (RFC 768) is supported. The developer can
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send UDP datagrams (client side support) or create a listener to receive
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UDP packets destined to certain port (server side support).
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* **TCP** Transmission Control Protocol (RFC 793) is supported. Both server
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and client roles can be used the the application. The amount of TCP sockets
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that are available to applications can be configured at build time.
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2017-08-01 21:08:58 +08:00
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* **BSD Sockets API** Experimental support for a subset of a BSD Sockets
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compatible API is implemented. Both blocking and non-blocking DGRAM (UDP)
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2017-09-01 01:31:06 +08:00
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and STREAM (TCP) sockets are supported.
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2017-08-01 21:08:58 +08:00
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2017-04-04 22:54:14 +08:00
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* **HTTP** Hypertext Transfer Protocol (RFC 2116) is supported. A simple
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library is provided that applications can use. Sample applications are
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implemented for :ref:`http-client-sample` and :ref:`http-server-sample`.
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Both :ref:`http-client-sample` and :ref:`http-server-sample` can use
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TLS (Transport Layer Security) v1.2 (RFC 5246) or SSL (Secure Sockets
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Layer) v3.0 (RFC 6101) functionality to encrypt the network traffic.
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The secured connections are provided by mbed library.
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* **MQTT** Message Queue Telemetry Transport (ISO/IEC PRF 20922) is supported.
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A sample :ref:`mqtt-publisher-sample` client application for MQTT v3.1.1 is
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implemented.
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* **CoAP** Constrained Application Protocol (RFC 7252) is supported. Both
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Both :ref:`zoap-client-sample` and :ref:`zoap-server-sample` sample
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applications are implemented. A :ref:`coap-client-sample` and
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:ref:`coap-server-sample` using DTLS (Datagram Transport Layer Security)
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(RFC 6347) are also implemented.
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2017-07-08 02:04:03 +08:00
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* **LWM2M** OMA Lightweight Machine-to-Machine Protocol (V1.0 Feb 2017) is
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supported via the "Register Device" API (Register, De-Register and Update)
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2017-09-01 01:31:06 +08:00
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and has template implementations for Security, Server, Device Management and
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2017-07-08 02:04:03 +08:00
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Firmware objects. DTLS and Bootstrap support are currently not supported.
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:ref:`lwm2m-client-sample` implements the library as an example.
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2017-04-04 22:54:14 +08:00
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* **RPL** IPv6 Routing Protocol for Low-Power and Lossy Networks (RFC 6550)
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is supported. RPL is an IPv6 based mesh routing protocol.
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* **DNS** Domain Name Service (RFC 1035) client functionality is supported.
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Applications can use an API to query domain name information or IP addresses
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from the DNS server. Both IPv4 (A) and IPv6 (AAAA) records can be queried.
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* **Network Management API.** Applications can use network management API to
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listen management events generated by core stack when for example IP address
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is added to the device, or network interface is coming up etc.
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* **Multiple Network Technologies.** The Zephyr OS can be configured to
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support multiple network technologies at the same time simply by enabling
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them in Kconfig: for example, Ethernet and 802.15.4 support. Note that no
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automatic IP routing functionality is provided between these technologies.
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Applications can send data according to their needs to desired network
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interface.
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* **Minimal Copy Network Buffer Management.** It is possible to have minimal
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copy network data path. This means that the system tries to avoid copying
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application data when it is sent to the network. For some technologies it
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is even possible to have zero-copy data path from application to device
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driver.
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2017-08-01 21:08:58 +08:00
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Additionally these network technologies (link layers) are supported in
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Zephyr OS v1.7 and later:
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2017-02-02 22:27:05 +08:00
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* IEEE 802.15.4
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* Bluetooth
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* Ethernet
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2017-08-01 21:08:58 +08:00
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* SLIP (IP over serial line). Used for testing with QEMU. It provides
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ethernet interface to host system (like Linux) and test applications
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can be run in Linux host and send network data to Zephyr OS device.
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2017-02-02 22:27:05 +08:00
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Source Tree Layout
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******************
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The IP stack source code tree is organized as follows:
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``subsys/net/ip/``
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This is where the IP stack code is located.
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2017-08-01 21:08:58 +08:00
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``subsys/net/lib/``
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Application-level protocols (DNS, MQTT, etc.) and additional stack
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components (BSD Sockets, etc.).
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2017-02-02 22:27:05 +08:00
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``include/net/``
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Public API header files. These are the header files applications need
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to include to use IP networking functionality.
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``samples/net/``
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Sample networking code. This is a good reference to get started with
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network application development.
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``tests/net/``
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Test applications. These applications are used to verify the
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functionality of the IP stack, but are not the best
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source for sample code (see ``samples/net`` instead).
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