DFDL Schemas for Ethernet and IP
It works with Daffodil (from Daffodil version 3.2.0), but not with IBM DFDL (as of 2021-06-08) as the latter does not yet support the dfdl:inputValueCalc, dfdl:outputValueCalc, dfdl:hiddenGroupRef, dfdl:valueLength(), dfdl:contentLength(), and dfdl:newVariableInstance DFDL capabilities.
As of version 1.1.0 of this DFDL schema, it also uses a Daffodil-specific DFDL extension called layers in order to compute IPv4 checksums as part of parsing and unparsing.
This schema was created based on the corresponding DFDL types in the PCAP schema, which has been refactored to use this schema as a dependency.
This division into two schemas is intended to illustrate how to structure DFDL schemas as separate DFDL schemas that are combined together to form a complete format, and which involve layering where a container/envelope/header structure, contains a payload structure. PCAP is an container format for Ethernet/IP packets.