Jon Shallow
415fbdb7cd
A unique Request-Tag is added to any PUT/POST/FETCH request that contains a large body. The server is then able to differentiate between concurrent sending of large data using the same session. If a server responds with a 4.01 and includes an Echo option, then the libcoap client retransmits the request adding in the received Echo option with the same value. If the server responds normally with an Echo option, then the next request from the libcoap client (internally added by libcoap) will contain that Echo option. It is the responsibility of the server application to add in the Echo option if required and validate the next request unless the Echo is triggered by OSCORE (RFC8613 Appendix B.1.2).
3.3 KiB
libcoap: A C implementation of the Constrained Application Protocol (RFC 7252)
Copyright (C) 2010—2022 by Olaf Bergmann bergmann@tzi.org and others
ABOUT LIBCOAP
libcoap is a C implementation of a lightweight application-protocol for devices that are constrained their resources such as computing power, RF range, memory, bandwidth, or network packet sizes. This protocol, CoAP, is standardized by the IETF as RFC 7252. For further information related to CoAP, see http://coap.technology.
You might want to check out libcoap-minimal for usage examples.
DOCUMENTATION
Documentation and further information can be found at https://libcoap.net.
PACKAGE CONTENTS
This package contains a protocol parser and basic networking functions for platforms with support for malloc() and BSD-style sockets. In addition, there is support for Contiki, LwIP and Espressif/ESP-IDF hosted environments.
The following RFCs are supported
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RFC7252: The Constrained Application Protocol (CoAP)
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RFC7390: Group Communication for the Constrained Application Protocol (CoAP)
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RFC7641: Observing Resources in the Constrained Application Protocol (CoAP)
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RFC7959: Block-Wise Transfers in the Constrained Application Protocol (CoAP)
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RFC7967: Constrained Application Protocol (CoAP) Option for No Server Response
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RFC8132: PATCH and FETCH Methods for the Constrained Application Protocol (CoAP)
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RFC8323: CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets [No WebSockets support]
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RFC8768: Constrained Application Protocol (CoAP) Hop-Limit Option
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RFC9175: CoAP: Echo, Request-Tag, and Token Processing
There is (D)TLS support for the following libraries
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OpenSSL (Minimum version 1.1.0) [PKI, PSK and PKCS11]
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GnuTLS (Minimum version 3.3.0) [PKI, PSK, RPK(3.6.6+) and PKCS11]
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Mbed TLS (Minimum version 2.7.10) [PKI and PSK]
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TinyDTLS [PSK and RPK] [DTLS Only]
The examples directory contain a CoAP client, CoAP Resource Directory server and a CoAP server to demonstrate the use of this library.
BUILDING
Further information can be found at https://libcoap.net/install.html and BUILDING.
LICENSE INFORMATION
This library is published as open-source software without any warranty of any kind. Use is permitted under the terms of the simplified BSD license. It includes public domain software. libcoap binaries may also include open-source software with their respective licensing terms. Please refer to LICENSE for further details.