# zephyr/Kconfig for libcoap

#

# Copyright (C) 2023-2026 Jon Shallow <supjps-libcoap@jpshallow.com>

#

# SPDX-License-Identifier: BSD-2-Clause

#

# This file is part of the CoAP library libcoap. Please see README for terms

# of use.

#

###############################################################################

menu "libcoap Settings"

config LIBCOAP

bool "Enable libcoap"

help

This option enables libcoap as a Zephyr module.

endmenu

if LIBCOAP

config LIBCOAP_IPV4_SUPPORT

bool "Enable IPv4 support within CoAP"

default y

help

Enable IPv4 functionality for CoAP.

If this option is disabled, redundant CoAP IPv4 code is removed.

config LIBCOAP_IPV6_SUPPORT

bool "Enable IPv6 support within CoAP"

default y

help

Enable IPv6 functionality for CoAP.

If this option is disabled, redundant CoAP IPv6 code is removed.

config LIBCOAP_TCP_SUPPORT

bool "Enable TCP support within CoAP"

default n

help

Enable TCP functionality for CoAP. This is required if TLS sessions

are to be used. Note that RIOT TCP support also needs to be enabled.

If this option is disabled, redundant CoAP TCP code is removed.

config LIBCOAP_OSCORE_SUPPORT

bool "Enable OSCORE support within CoAP"

default n

help

Enable OSCORE functionality for CoAP.

If this option is disabled, redundant CoAP OSCORE code is removed.

config LIBCOAP_OBSERVE_PERSIST

bool "Enable Observe persist support within CoAP"

default n

help

Enable Observe persist functionality for CoAP.

If this option is disabled, redundant CoAP Observe persist code is removed.

config LIBCOAP_WS_SOCKET

bool "Enable WebSocket support within CoAP"

default n

help

Enable WebSocket functionality for CoAP.

If this option is disabled, redundant CoAP WebSocket code is removed.

config LIBCOAP_Q_BLOCK_SUPPORT

bool "Enable Q-Block (RFC9177) support within CoAP"

default n

help

Enable Q-Block (RFC9177) functionality for CoAP.

If this option is disabled, redundant CoAP Q-Block code is removed.

config LIBCOAP_ASYNC_SUPPORT

bool "Enable separate responses support within CoAP"

default y

help

Enable async separate responses functionality for CoAP.

If this option is disabled, redundant CoAP async separate responses code is removed.

config LIBCOAP_THREAD_SAFE_SUPPORT

bool "Enable thread safe support within CoAP"

default y

help

Enable thread safe support functionality for CoAP.

If this option is disabled, multi-thread safe use of libcoap is not available.

config LIBCOAP_THREAD_RECURSIVE_CHECK

bool "Enable thread-safe recursion checking support within CoAP"

depends on LIBCOAP_THREAD_SAFE_SUPPORT

default n

help

Enable thread-safe recursion checking support for CoAP.

config LIBCOAP_ENABLE_THREAD_NUM_LOGGING

bool "Enable building with thread number logging support"

depends on LIBCOAP_THREAD_SAFE_SUPPORT

default y

help

Enable logging including thread number.

If this option is disabled, the thread number is not reported.

config LIBCOAP_CLIENT_SUPPORT

bool "Enable Client functionality within CoAP"

default n

help

Enable client functionality (ability to make requests and receive

responses) for CoAP. If the server is going to act as a proxy, then

this needs to be enabled to support the ongoing session going to

the next hop.

If this option is disabled, redundant CoAP client only code is

removed.

If both this option and LIBCOAP_SERVER_SUPPORT are disabled, then

both are automatically enabled for backwards compatibility.

config LIBCOAP_SERVER_SUPPORT

bool "Enable Server functionality within CoAP"

default n

help

Enable server functionality (ability to receive requests and send

responses) for CoAP.

If this option is disabled, redundant CoAP server only code is

removed.

If both this option and LIBCOAP_CLIENT_SUPPORT are disabled, then

both are automatically enabled for backwards compatibility.

config LIBCOAP_DEBUGGING

bool "Enable CoAP debugging"

default y

help

Enable CoAP debugging functions at compile time for the example code.

If this option is enabled, call coap_set_log_level()

at runtime in order to enable CoAP debug output.

choice LIBCOAP_DEBUGGING_LEVEL

bool "Set CoAP debugging level"

depends on LIBCOAP_DEBUGGING

default LIBCOAP_LOG_DEBUG

help

Set CoAP debugging level

Note: reducing the logging level also reduces the code size.

config LIBCOAP_LOG_EMERG

bool "Emergency"

config LIBCOAP_LOG_ALERT

bool "Alert"

config LIBCOAP_LOG_CRIT

bool "Critical"

config LIBCOAP_LOG_ERROR

bool "Error"

config LIBCOAP_LOG_WARNING

bool "Warning"

config LIBCOAP_LOG_NOTICE

bool "Notice"

config LIBCOAP_LOG_INFO

bool "Info"

config LIBCOAP_LOG_DEBUG

bool "Debug"

config LIBCOAP_LOG_OSCORE

bool "OSCORE"

endchoice

config LIBCOAP_LOG_DEFAULT_LEVEL

int

default 0 if !LIBCOAP_DEBUGGING

default 0 if LIBCOAP_LOG_EMERG

default 1 if LIBCOAP_LOG_ALERT

default 2 if LIBCOAP_LOG_CRIT

default 3 if LIBCOAP_LOG_ERROR

default 4 if LIBCOAP_LOG_WARNING

default 5 if LIBCOAP_LOG_NOTICE

default 6 if LIBCOAP_LOG_INFO

default 7 if LIBCOAP_LOG_DEBUG

default 8 if LIBCOAP_LOG_OSCORE

config LIBCOAP_DEFAULT_MAX_PDU_RX_SIZE

int "Default max PDU RX size in bytes"

default 1152

help

Maximum size of incoming CoAP PDU. RFC7252 4.6 suggests 1152.

Increase for larger block-wise transfers (e.g. 1024-4096).

config LIBCOAP_RXBUFFER_SIZE

int "Receive buffer size in bytes"

default 1472

help

Size of the socket receive buffer for incoming CoAP/UDP packets.

Should be at least as large as the largest expected PDU (e.g. 1472

for typical Ethernet MTU minus headers).

config LIBCOAP_DEFAULT_MTU

int "Default MTU in bytes"

default 1152

help

Default path/session MTU used for CoAP (RFC7252 4.6 suggests 1152).

Used for session MTU and PDU sizing; increase for larger block-wise

transfers.

config LIBCOAP_OBS_MAX_NON

int "Observe: max NON notifications before CON"

default 5

range 1 255

help

Number of NON notifications before sending a CON (RFC7641 4.5).

config LIBCOAP_DEFAULT_MAX_LATENCY

int "Default max latency in seconds"

default 100

help

Maximum network latency used by CoAP timeout calculations.

RFC7252 Section 4.8.2 specifies a default of 100 seconds.

config LIBCOAP_DEFAULT_SESSION_TIMEOUT

int "Default session timeout"

default 300

help

This setting refers to the COAP_DEFAULT_SESSION_TIMEOUT, which defines server session's timeout.

if MBEDTLS

config MBEDTLS_OSCORE

bool "Set if OSCORE only"

default n

config MBEDTLS_CIPHER_CCM_ENABLED

bool

default y

config MBEDTLS_DEBUG

bool

default y

config MBEDTLS_KEY_EXCHANGE_RSA_ENABLED

bool

default y

config MBEDTLS_ENTROPY_ENABLED

bool

default y

config MBEDTLS_ZEPHYR_ENTROPY

bool

default y

config MBEDTLS_SSL_PROTO_TLS1_2

bool

default y

config MBEDTLS_KEY_EXCHANGE_ALL_ENABLED

bool

default y

config MBEDTLS_CIPHER_ALL_ENABLED

bool

default n

config MBEDTLS_ECP_ALL_ENABLED

bool

default n

config MBEDTLS_MAC_ALL_ENABLED

bool

default y

config MBEDTLS_GENPRIME_ENABLED

bool

default y

config MBEDTLS_ECDH_C

bool

default y

config MBEDTLS_ECDSA_C

bool

default y

config MBEDTLS_ECJPAKE_C

bool

default y

config MBEDTLS_ECP_C

bool

default y

if ! MBEDTLS_OSCORE

config MBEDTLS_SERVER_NAME_INDICATION

bool

default y

config MBEDTLS_SSL_PROTO_DTLS

bool

default y

config MBEDTLS_SSL_DTLS_CONNECTION_ID

bool

default y

config MBEDTLS_PEM_CERTIFICATE_FORMAT

bool

default y

config MBEDTLS_SSL_EXTENDED_MASTER_SECRET

bool

default y

endif # ! MBEDTLS_OSCORE

config MBEDTLS_HAVE_TIME_DATE

bool

default y

endif # MBEDTLS

module = LIBCOAP

module-str = libcoap

source "${ZEPHYR_BASE}/subsys/logging/Kconfig.template.log_config"

endif # LIBCOAP