doc: release-notes: Add 4.0.0 release notes for networking

Networking

**********

* 802.15.4:

  * Implemented support for beacons without association bit.

  * Implemented support for beacons payload.

  * Fixed a bug where LL address endianness was swapped twice when deciphering a frame.

  * Fixed missing context lock release when checking destination address.

  * Improved error logging in 6LoWPAN fragmentation.

  * Improved error logging in 802.15.4 management commands.

* ARP:

  * Fixed ARP probe verification during IPv4 address conflict detection.

* CoAP:

* Connection manager:

  * Added new API :c:func:`coap_rst_init` to simplify creating RST replies.

  * Implemented replying with CoAP RST response for unknown queries in CoAP client.

  * Added support for runtime configuration of ACK random factor parameter.

  * Added support for No Response CoAP option.

  * Added a new sample demonstrating downloading a resource with GET request.

  * Fixed handling of received CoAP RST reply in CoAP client.

  * Fixed socket error reporting to the application in CoAP client.

  * Fixed handling of response retransmissions in CoAP client.

  * Fixed a bug where CoAP block numbers were limited to ``uint8_t``.

  * Various fixes in the block transfer support in CoAP client.

  * Improved handling of truncated datagrams in CoAP client.

  * Improved thread safety of CoAP client.

  * Fixed missing ``static`` keyword in some internal functions.

  * Various other minor fixes in CoAP client.

* DHCPv4:

  * Added support for parsing multiple DNS servers received from DHCP server.

  * Added support for DNS Server option in DHCPv4 server.

  * Added support for Router option in DHCPv4 server.

  * Added support for application callback which allows to assign custom addresses

    in DHCPv4 server.

  * Fixed DNS server list allocation in DHCPv4 client.

  * Fixed a bug where system workqueue could be blocked indefinitely by DHCPv4 client.

* DHCPv6:

  * Fixed a bug where system workqueue could be blocked indefinitely by DHCPv6 client.

* DNS/mDNS/LLMNR:

  * Added support for collecting DNS statistics.

  * Added support for more error codes in :c:func:`zsock_gai_strerror`.

  * Fixed handling of DNS responses encoded with capital letters.

  * Fixed DNS dispatcher operation on multiple network interfaces.

  * Fixed error being reported for mDNS queries with query count equal to 0.

  * Various other minor fixes in DNS/mDNS implementations.

* Ethernet:

* gPTP/PTP:

  * Fixed handling of second overflow/underflow.

  * Fixed PTP clock adjusting with offset.

* HTTP:

* IPSP:

  * Added support for specifying response headers and response code by the application.

  * Added support for netusb in the HTTP server sample.

  * Added support for accessing HTTP request headers from the application callback.

  * Added support for handling IPv4 connections over IPv6 socket in HTTP server.

  * Added support for creating HTTP server instances without specifying local host.

  * Added overlays to support HTTP over IEEE 802.15.4 for HTTP client and server

    samples.

  * Added support for static filesystem resources in HTTP server.

  * Fixed assertion in HTTP server sample when resource upload was aborted.

  * Refactored dynamic resource callback format for easier handling of short

    requests/replies.

  * Fixed possible busy-looping in case of errors in the HTTP server sample.

  * Fixed possible incorrect HTTP headers matching in HTTP server.

  * Refactored HTTP server sample to better demonstrate server use cases.

  * Fixed processing of multiple HTTP/1 requests over the same connection.

  * Improved HTTP server test coverage.

  * Various other minor fixes in HTTP server.

* IPv4:

  * Improved IGMP test coverage.

  * Fixed IGMPv2 queries processing when IGMPv3 is enabled.

  * Fixed :kconfig:option:`CONFIG_NET_NATIVE_IPV4` dependency for native IPv4 options.

  * Fix net_pkt leak in :c:func:`send_ipv4_fragment`.`

* IPv6:

  * Added a public header for Multicast Listener Discovery APIs.

  * Added new :c:func:`net_ipv6_addr_prefix_mask` API function.

  * Made IPv6 Router Solicitation timeout configurable.

  * Fixed endless IPv6 packet looping with both routing and VLAN support enabled.

  * Fixed unneeded error logging in case of dropped NS packets.

  * Fixed accepting of incoming DAD NS messages.

  * Various fixes improving IPv6 routing.

* LwM2M:

  * Location object: optional resources altitude, radius, and speed can now be

  * Added TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 to DTLS cipher list.

  * Added LwM2M shell command for listing resources.

  * Added LwM2M shell command to list observations.

  * Added support for accepting SenML-CBOR floats decoded as integers.

  * Added support for X509 hostname verification if using certificates, when

    URI contains valid name.

  * Regenerated generated code files using zcbor 0.9.0 for lwm2m_senml_cbor.

  * Improved thread safety of the LwM2M engine.

  * Fixed block transfer issues for composite operations.

  * Fixed enabler version reporting during bootstrap discovery.

  * Removed unneeded Security object instance from the LwM2M client sample.

  * Fixed buffer size check for U16 resource.

  * Removed deprecated APIs and configs.

  * Optional Location object resources altitude, radius, and speed can now be

    used optionally as per the location object's specification. Users of these

    resources will now need to provide a read buffer.

  * lwm2m_senml_cbor: Regenerated generated code files using zcbor 0.9.0

  * Fixed the retry counter not being reset on successful Registration update.

  * Fixed REGISTRATION_TIMEOUT event not always being emitted on registration

    errors.

  * Fixed c++ support in LwM2M public header.

  * Fixed a bug where DISCONNECTED event was not always emitted when needed.

* Misc:

  * Added support for network packet allocation statistics.

  * Added a new library implementing Prometheus monitoring support.

  * Added USB CDC NCM support for Echo Server sample.

  * Added packet drop statistics for capture interfaces.

  * Added new :c:func:`net_hostname_set_postfix_str` API function to set hostname

    postfix in non-hexadecimal format.

  * Added API version information to public networking headers.

  * Implemented optional periodic SNTP time resynchronization.

  * Improved error reporting when starting/stopping virtual interfaces.

  * Fixed build error of packet capture library when variable sized buffers are used.

  * Fixed build error of packet capture library when either IPv4 or IPv6 is disabled.

  * Fixed CMake complaint about missing sources in net library in certain

    configurations.

  * Fixed compilation issues with networking and SystemView Tracing enabled.

  * Removed redundant DHCPv4 code from telnet sample.

  * Fixed build warnings in Echo Client sample with IPv6 disabled.

  * Removed deprecated net_pkt functions.

  * Extended network tracing support and added documentation page

    (:ref:`network_tracing`).

  * Moved network buffers implementation out of net subsystem into lib directory

    and renamed public header to :zephyr_file:`include/zephyr/net_buf.h`.

  * Deprecated the :c:func:`net_buf_put` and :c:func:`net_buf_get` API functions.

  * Removed ``wpansub`` sample.

* MQTT:

  * Updated information in the mqtt_publisher sample about Mosquitto broker

    configuration.

  * Updated MQTT tests to be self-contained, no longer requiring external broker.

  * Optimized buffer handling in MQTT encoder/decoder.

* Network contexts:

  * Fixed IPv4 destination address setting when using :c:func:`sendmsg` with

    :kconfig:option:`CONFIG_NET_IPV4_MAPPING_TO_IPV6` option enabled.

  * Fixed possible unaligned memory access when in :c:func:`net_context_bind`.

  * Fixed missing NULL pointer check for V6ONLY option read.

* Network Interface:

* OpenThread

  * Added new :c:func:`net_if_ipv4_get_gw` API function.

  * Fixed checksum offloading checks for VLAN interfaces.

  * Fixed native IP support being required to  register IP addresses on an

    interface.

  * Fixed missing mutex locks in a few net_if functions.

  * Fixed rejoining of IPv6 multicast groups.

  * Fixed :c:func:`net_if_send_data` operation for offloaded interfaces.

  * Fixed needless IPv6 multicast groups joining if IPv6 is disabled.

  * Fixed compiler warnings when building with ``-Wtype-limits``.

* OpenThread:

  * Added support for :kconfig:option:`CONFIG_IEEE802154_SELECTIVE_TXCHANNEL`

    option in OpenThread radio platform.

  * Added NAT64 send and receive callbacks.

  * Added new Kconfig options:

* PPP

    * :kconfig:option:`CONFIG_OPENTHREAD_NAT64_CIDR`

    * :kconfig:option:`CONFIG_OPENTHREAD_STORE_FRAME_COUNTER_AHEAD`

    * :kconfig:option:`CONFIG_OPENTHREAD_DEFAULT_RX_SENSITIVITY`

    * :kconfig:option:`CONFIG_OPENTHREAD_CSL_REQUEST_TIME_AHEAD`

  * Fixed deprecated/preferred IPv6 address state transitions.

  * Fixed handling of deprecated IPv6 addresses.

  * Other various minor fixes in Zephyr's OpenThread port.

* Shell:

  * Added support for enabling/disabling individual network shell commands with

    Kconfig.

  * Added new ``net dhcpv4/6 client`` commands for DHCPv4/6 client management.

  * Added new ``net virtual`` commands for virtual interface management.

  * ``net ipv4/6`` commands are now available even if native IP stack is disabled.

  * Added new ``net cm`` commands exposing Connection Manager functionality.

  * Fixed possible assertion if telnet shell backend connection is terminated.

  * Event monitor thread stack size is now configurable with Kconfig.

  * Relocated ``bridge`` command under ``net`` command, i. e. ``net bridge``.

  * Multiple minor improvements in various command outputs.

* Sockets:

* Syslog:

  * Added dedicated ``net_socket_service_handler_t`` callback function type for

    socket services.

  * Added TLS 1.3 support for TLS sockets.

  * Fixed socket leak when closing NSOS socket.

  * Moved socket service library out of experimental.

  * Deprecated ``CONFIG_NET_SOCKETS_POLL_MAX``.

  * Moved ``zsock_poll()`` and ``zsock_select`` implementations into ``zvfs``

    library.

  * Removed ``work_q`` parameter from socket service macros as it was no longer

    used.

  * Separated native INET sockets implementation from socket syscalls so that

    it doesn't have to be built when offloaded sockets are used.

  * Fixed possible infinite block inside TLS socket :c:func:`zsock_connect` when

    peer goes down silently.

  * Fixed ``msg_controllen`` not being set correctly in :c:func:`zsock_recvmsg`.

  * Fixed possible busy-looping when polling TLS socket for POLLOUT event.

* TCP:

  * Fixed propagating connection errors to the socket layer.

  * Improved ACK reply logic when peer does not send PSH flag with data.

* Websocket:

  * Added support for Websocket console in the Echo Server sample.

  * Fixed undefined reference to ``MSG_DONTWAIT`` while building websockets

    without POSIX.

* Wi-Fi:

* zperf:

  * Added support for USB CDC NCM in the zperf sample.

  * Fixed DHCPv4 client not being started in the zperf sample in certain

    configurations.

USB

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